Novel Trends in Chemistry, Research and Education 2025

BOOK OF ABSTRACTS Pavol Jozef Šafárik University in Košice Faculty of Science Institute of Chemistry Mgr. Soňa Király (ed.) Košice 2025 Novel Trends in Chemistry, Research and Education 2025 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 Edited by: Mgr. Soňa Király, Department of Physical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovakia [email protected] Reviewed by: doc. RNDr. Silvia Ružičková, PhD., Department of Environmental Technologies, Institute of Recycling and Environmental Technologies, Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 040 01, Košice, Slovak Republic, [email protected] doc. RNDr. Zuzana Gažová, DrSc., Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic, [email protected] prof. Ing. Marián Koman, DrSc., Department of Inorganic Chemistry, Institute of Inorganic Chemistry, Technology and Materials, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovak Republic, [email protected] RNDr. Aneta Salayová, PhD., Department of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81 Košice, Slovak Republic, [email protected] RNDr. Eva Mezeiová, PhD., Biomedical Research Centre, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic, [email protected] Kadir Özaltin, M.Sc., Ph.D., Centre of Polymer Systems, Tomas Bata University in Zlín, 760 01 Zlín, Czech Republic, [email protected] Organisation Committee: RNDr. Ivana Šišoláková, PhD. RNDr. Jana Shepa, PhD. RNDr. Radka Gorejová, PhD. Mgr. Soňa Király Ing. Petronela Polanská Novel Trends in Chemistry, Research and Education 2025 Book of Abstracts This text is published under the Creative Commons 4.0 license - CC BY NC SA ("Attribution - Do not use commercially - ShareAlike"). The authors bear sole responsibility for the scientific and linguistic content. The manuscript has not been subjected to editorial or language revision. Available at: www.unibook.upjs.sk Publication date: 27.11. 2025 DOI: https://doi.org/10.33542/NTI-0469-9 ISBN 978-80-574-0469-9 (e-publication) Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 3 THIS EVENT WAS SUPPORTED BY Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 4 LIST OF CONTENTS Conference Programme ……………………………………………………………………. 5 Invited Lectures …………………………………………………………………………….. 6 Plenary Lectures …………………………………………………………………………… 13 Sessions 1-7 Analytical Chemistry ……………………………………………………………………… 18 Biochemistry ……………………………………………………………………………….. 23 Didactics of Chemistry …………………………………………………………………….. 45 Inorganic Chemistry ………………………………………………………………………. 46 Laboratory of NMR Spectroscopy ………………………………………………………… 80 Organic Chemistry ………………………………………………………………………… 83 Physical Chemistry ……………………………………………………………………….. 104 List of Posters …………………………………………………………………………….. 120 List of Authors ……………………………………………………………………………. 121 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 5 CONFERENCE PROGRAMME Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 6 INVITED LECTURES ANYLYTICAL CHEMISTRY Design and properties of multi-target agents based on quinoline scaffold J. Jampileka,b* a Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 842 15 Bratislava, Slovak Republic b Department of Chemical Biology, Faculty of Science, Palacky University Olomouc, Slechtitelu 27, 783 71 Olomouc, Czech Republic *[email protected] An innovative strategy in modern drug discovery involves the design of multi-target compounds, also known as multi-target directed ligands (MTDLs) or “promiscuous drugs”. Multi-target agents are single chemical entities designed to interact simultaneously or sequentially with two or more biological targets that are key to the mechanism or progression of a disease. This strategy contrasts with the traditional “one drug, one target” paradigm of drug discovery [1,2]. This approach is based on the concepts of privileged structures, polypharmacology and multifactorial diseases [3,4]. It appears to be a useful tool in the design of anti-invasive drugs, as the therapeutic agents designed in this way interact with multiple targets, thereby preventing resistance or being able to destroy resistant pathogens/cells [5-7]. Similarly, multi-target drugs can be designed for the simultaneous treatment of autoimmune and inflammatory diseases [2,4]. Quinoline-based compounds have a wide range of promising biological properties, which is why they are receiving special attention in drug design and medicinal chemistry [8,9]. The quinoline scaffold can be easily and rapidly synthesized, indicating the importance of this privileged structure [10,11]. Furthermore, this simple structural element has unique physicochemical properties and allows for a large number of targeted modifications [12-18]. This contribution focuses on the design and investigating several series of ring-substituted hydroxyand/or aminoquinolines. Acknowledgements This study was supported by projects APVV-17-0318, APVV-22-0133 and VEGA 1/0727/25. References [1] A. Talevi, Front. Pharmacol. 6 (2015) 205. [2] S.H. Cemali, S. Poyraz, S. Belveren, et al. ChemMedChem. 20 (2025) e202500447. [3] M. Abdelsayed, Int. J. Mol. Sci. 26 (2025) 6996. [4] R.R. Ramsay, M.R. Popovic-Nikolic, K. Nikolic, et al. Clin. Transl. Med. 7 (2018) 3. [5] D.A. Gray, M. Wenzel, ACS Infect. Dis. 6 (2020) 1346-1365. [6] J. Feng, Y. Zheng, W. Ma, et al. Pharmacol. Ther. 252 (2023) 108550. [7] I. Gajic, N. Tomic, B. Lukovic, et al. Antibiotics 14 (2025) 221. [8] P. Yadav, K. Shah, Bioorg. Chem. 109 (2021) 104639. [9] O.F. Elebiju, O.O. Ajani, G.O. Oduselu, et al. Front. Chem. 10 (2023) 1074331. [10] V. Yadav, J. Reang, V. Sharma, et al. Chem. Biol. Drug Des. 100 (2022) 389-418. [11] I.A. Bala, O.F. Al Sharif, A.M. Asiri, et al. Results Chem. 7 (2024) 101529. [12] J. Jampilek, M. Dolezal, V. Opletalova, et al. Curr. Med. Chem. 13 (2006) 117-129. [13] R. Musiol, J. Jampilek, V. Buchta, et al. Bioorg. Med. Chem. 14 (2006) 3592-3598. [14] W. Cieslik, R. Musiol, J. Nycz, et al. Bioorg. Med. Chem. 20 (2012) 6960-6968. [15] J. Kos, I. Zadrazilova, E. Nevin, et al. Bioorg. Med. Chem. 23 (2015) 4188-4196. [16] K. Pavic, I. Perkovic, S. Pospisilova. Eur. J. Med. Chem. 143 (2018) 769-779. [17] J. Kos, C.F. Ku, I. Kapustikova, et al. ChemistrySelect 4 (2019) 4582-4587. [18] K. Malarz, M. Kuczak, P. Rurka, et al. Sci. Rep. 15 (2025) 16081. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 7 INVITED LECTURES BIOCHEMISTRY Breaking Amyloid with Light: Azobenzene Derivatives as Photo-Responsive Agents Against Aβ Aggregation Z. Bednarikovaa*, P. Kozminskib, D. Niedzialekc, G. Wieczorekc, Z. Gazovaa a Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Kosice, Slovakia b Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, Warsaw, Poland c Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, Warsaw, Poland *bednarik[email protected] Amyloid fibrils formed by amyloid β (Aβ) peptides are a defining neuropathological hallmark of Alzheimer’s disease (AD), a rapidly growing and currently incurable neurodegenerative disorder. Developing new strategies to modulate and eliminate these aggregates remains a critical challenge. In this work, we harness the reversible photo-induced isomerization of azobenzene molecules—switching between cis (nonplanar, metastable) and trans (planar, thermodynamically stable) conformations—to mechanically disrupt Aβ fibrils. We designed and evaluated azobenzene-based compounds containing one or two azobenzene moieties linked by DTPA, integrating in vitro, in silico, and cellular approaches. The DTPA-linked azobenzene dimer DTPA-(AZB)₂ demonstrated potent fibril-dissociating activity at low micromolar concentrations, with approx. 10-fold enhancement upon light-induced isomerization. These compounds converted fibrils into non-cytotoxic species, highlighting their therapeutic potential. Our in silico analyses suggest that photo-switching imposes mechanical stress on β-strands, facilitating fibril disruption. Furthermore, we show that both light and calcium ions significantly amplify the dissociation efficiency, and experiments performed in artificial cerebrospinal fluid confirm activity under physiologically relevant conditions. Together, these findings establish DTPA-(AZB)₂ as a promising photo-switchable modulator of amyloid structures and lay the groundwork for future development of light-controlled therapeutic strategies for AD and related neurodegenerative diseases. Acknowledgements This work was supported by the Slovak Research and Development Agency under the Contract no. APVV-220598; Slovak Grant Agency VEGA 02/0141/25; Mobility grant PAS-SAS-2022-13 and MVTS-COST CA21160. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 8 INVITED LECTURES DIDACTICS OF CHEMISTRY Chemistry Teacher Training J. Kmetovaa* aDepartment of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, Banská Bystrica, Slovakia *[email protected] University teacher training is a key link in the chain connecting social expectations, education policies, and the actual learning of students in schools. The quality of teachers has long been identified as one of the most important factors influencing student outcomes and the overall success of school systems. International OECD reports and European Union documents systematically point to the need to strengthen teacher training, their continuous professional development, and the link between theory and practice. The aim of this contribution is to analyse the university education of chemistry teachers as a complex system shaped by a normative framework (Bologna Process, European Higher Education Area), national policies, academic traditions, and the dynamics of the school environment. Teacher and the professionalization of the teaching profession Most empirical studies in the field of education agree that teachers are the most important school factor influencing student outcomes, apart from family and socioeconomic background. This consensus is also reflected in the wellknown OECD report Teachers Matter: Attracting, Developing and Retaining Effective Teachers, which systematically analyses the policies of 25 countries and emphasizes that the quality of the school system cannot exceed the quality of its teachers in the long term. [1] Teacher training is therefore not just a technical process of "supplying" graduates to the labour market, but a strategic investment in the future of society. The way universities prepare future teachers has a fundamental impact on whether they will be able to respond to the challenges of the 21st century – globalization, digitalization, the climate crisis, growing classroom diversity, inclusive education, and increasing social inequalities. The professionalization of the teaching profession encompasses three basic dimensions. The first is professional competence – a deep understanding and knowledge of the subject matter in connection with the scientific discipline to which the subject is linked, and the ability to transform the scientific system into a didactic system (subject didactics). The second is pedagogical-psychological competence – knowledge of learning processes, motivation, development, and classroom social dynamics. The third is the ethical-reflective dimension – the ability to critically analyse one's own practice, reflect on values, and make decisions in accordance with professional ethics and moral character. An important part of professionalization is also the concept of professional standards for teachers, which in many countries serves as a reference framework for designing the content and structure of study programs in higher education teacher training or educational programs as part of their lifelong learning and professional development. In Europe, two basic models of approach to the construction of teacher training program content can be identified: concurrent/integrated and sequential/consecutive. The integrated model combines subjects in the field of study, teaching fundamentals, and subject didactics from the very first years of study, with students identifying with the teaching profession from the outset and teaching practice also being included from the beginning of their studies. The consecutive model, on the other hand, assumes that students first complete subjects in their field of study and then subjects in teaching fundamentals and subject didactics, including teaching practice. Chemistry teachers are currently trained at seven universities in Bratislava, Komárno, Trnava, Nitra, Banská Bystrica, Ružomberok, and Košice. The content and structure of these study programs vary, but all are designed as bachelor's and master's degrees. Based on the analysis, it can be concluded that universities have approached the creation of programs differently within their internal accreditations. Following the publication of the new description for the field of study of teaching and pedagogical sciences, it can be stated that the concurrent model prevails. The quality of teacher training is also linked to the status and professional development of university educators who train teachers. If future teachers are expected to use innovative, student-centered, and inclusive approaches, it is essential that they encounter such approaches during their own university studies. This requires systematic support for the development of the pedagogical and didactic competencies of university teachers. References [1] Teachers Matter | OECD Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 9 INVITED LECTURES INORGANIC CHEMISTRY MXene-based materials: Novel catalysts for wastewaters treatment O. Monforta* a Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University Bratislava, Ilkovicova 6, Mlynska dolina, 84215 Bratislava, Slovakia *olivier.mo[email protected] General participation rules Wastewater treatments are a crucial challenge worldwide as their treated effluents are released into the natural environment. This point is a big concern since the current technologies are not 100% efficient, thus leading to pollution. With the release of new regulations, especially the European Directive No. 2024/3019 related to municipal wastewater treatments [1], the quality of the treated wastewaters should be addressed and MXenes (and particularly nanomaterials derived from MXenes) can potentially shape the future of wastewaters treatment. MXenes have found plenty of applications although they are currently investigated as cocatalysts in remediation processes [2,3]. In this presentation, I introduce first the environmental context along with scientific context of MXenes. Then, their used in the preparation of innovative catalysts for wastewaters treatment is highlighted where the example of oxidized MXenes is discussed for the degradation of pharmaceutical contaminants in water [4]. Mechanistic elucidations during the degradation process is also explained, as they are important parameters to consider for potential scale-up applications. The take-home message is that MXenes are promising catalysts that can contribute significantly to the EU Water Framework Directive [5]. Acknowledgements This work was financially supported by the Slovak Research and Development Agency (contract No. APVV-210039) and was the result of international collaborations: prof. M. Brigante (Université Clermont Auvergne, France), prof. M. Naguib (Tulane University, USA), Assoc. Prof. D. Dvoranova (Slovak University of Technology in Bratislava, Slovakia), Center of Nanotechnology and Advanced Materials directed by Assoc. Prof. T. Plecenik (Comenius University Bratislava, Slovakia). I acknowledge also the fantastic work of postdocs and students, especially Dr. Shalu Atri (Comenius University Bratislava, Slovakia) and Frantisek Zazimal (Masaryk University, Czechia). References [1] European Parliament and Council, Directive 2024/3019 concerning urban wastewater treatment; in: Official Journal of the European Union. [2] M. M. Tunesi, R. A. Soomro, X. Han, Q. Zhu, Y. Wei, B. Xu, Nano Convergence 8 (2021) 5. [3] M. Akbari, J. Rasouli, S. Ghaedi, M. Mohammadi, H. Rajabi, S. Sabbaghi, Sci. Rep. 14 (2024) 31498. [4] S. Atri, E. Loni, Z. Dyrcikova, F. Zazimal, M. Caplovicova, D. Dvoranova, G. Plesch, M. Kabatova, M. Brigante, M. Naguib, O. Monfort, Nanoscale 16 (2024) 18430. [5] The EU Water Framework Directive, Publications Office (2014). Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 16 Scientific Grant Agency of the Slovak Republic (VEGA) (projects 1/0442/25 and 1/0058/25) for their current support. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 17 PLENARY LECTURES PHYSICAL CHEMISTRY Electrochemical Mechanism of Insulin Oxidation on Cu-Enhanced Carbon Paste Electrodes I. Sisolakovaa*, S. Vanchaka, R. Filipa, I. Shepab, J. Jascisakc, J. Shepaa aDepartment of Physical Chemistry, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic c FECUPRAL, spol s.r.o, Jilemnického 3578, 080 01, Prešov, Slovak republic *[email protected] In this study, the insulin oxidation mechanism on two previously prepared copper-modified carbon paste electrodes (CPEs) was studied. The electrode modifications were prepared from carbon powder obtained from waste sources combined with coconut oil, which served as a natural binder. Thereafter copper particles were deposited onto the electrode surface using two different methods: cyclic voltammetry (CV Cu/CPE) and pulsed electrodeposition carried out in fifteen cycles (15pCu/CPE). To study the insulin oxidation mechanism on unmodified and both modified electrodes cyclic voltammetry method was performed. Measurements were realized in pure PBS and in a 5 µM insulin in PBS with pH 9. The oxidation sequence on this electrode can be interpreted through the following steps (Eq. 1-2): 𝐶𝑢0+ 𝐻2𝑂→ 𝐶𝑢2𝑂+2𝐻++2𝑒−(approx. 0.0 V) (1) 𝐶𝑢2𝑂+𝐻2𝑂→𝐶𝑢𝑂+2𝐻++𝑒−(approx. 0.2 V – 0.5 V) (2) The scan-rate-dependent voltammograms for both modified electrodes were recorded. For each system, higher scan rates generate proportionally larger anodic and cathodic peak currents. The anodic peak shifts positively and the cathodic peak negatively as the scan rate increases, behaviour characteristic of quasi-reversible or irreversible charge-transfer processes. For the CV Cu/CPE a linear dependence of anodic peak current on the scan rate was observed. This linearity indicates that the process is dominated by adsorption. This is reasonable, as insulin can bind to Cu(II) species and form complexes on the electrode surface. The electron-transfer parameters were estimated using Laviron’s approach (Eq. 3): 𝐸𝑃(𝑉)=𝐸0´ −𝑅𝑇 𝛼𝑛𝐹𝑙𝑛𝑅𝑇𝑘𝑠 𝛼𝑛𝐹 +𝑅𝑇 𝛼𝑛𝐹ln𝑣 (3) From the Ep vs. v plot, the formal potential was determined as 0.089 V. The first oxidation step involves approximately 1.3 electrons, consistent with the proposed mechanism, and the heterogeneous rate constant was calculated to be 0.505 cm s⁻¹. These results suggest a quasi-reversible reaction in which one electron is exchanged in the initial step. The second oxidation wave does not follow a linear dependence on ln v, so Laviron’s model cannot be applied to it reliably. For the 15pCu/CPE log Ipa vs. log v the slope of 0.19 is far below the expected values for diffusion- (0.5) or adsorption-controlled (1.0) systems, indicating that the rate is primarily limited by electron-transfer kinetics. This interpretation is also supported by the growing peak separation at higher scan rates. In this case, the first oxidation peak overlaps strongly with the second one, especially at elevated scan rates, which complicates the analysis and prevents a clean application of Laviron’s theory to extract accurate kinetic parameters. Based on obtained results we can conclude that copper-modified carbon paste electrodes prepared from wastederived carbon enabled the study of insulin oxidation, with the CV Cu/CPE showing an adsorption-controlled process and a quasi-reversible initial one-electron step. The 15pCu/CPE was limited mainly by electron-transfer kinetics, as indicated by the low log Ipa vs. log v slope and increasing peak separation. Overall, the results show that the copper deposition method strongly affects the insulin oxidation mechanism and the ability to extract reliable kinetic parameters. Acknowledgements Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00180. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 18 SESSION 1 ANALYTICAL CHEMISTRY Applications of Liquid Chromatography for Direct Chiral Separation of Drugs V. Barillovaa, T. Gondovaa* aDepartment of Analytical Chemistry, Faculty of Science, P.J. Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] Chiral separations play an important role in the chromatographic analysis of various bioorganic compounds as well as drugs. Chiral drugs currently represent almost 50% of the total market, covering a wide range of therapeutic areas. Currently, the development and production of enantiomerically pure drugs is increasingly important because they provide higher efficacy and safety compared to racemates. Enantiomers may differ significantly in their pharmacological properties, therefore their separation is necessary. Various separation methods such as chromatography and capillary electrophoresis are used to separate racemic mixtures. Separation of racemic mixture into individual enantiomers can be achieved by using a derivatizing reagent or either a chiral stationary or chiral mobile phases. High-performance liquid chromatography on chiral stationary phases with various kinds of chiral selectors is applied as the method of first choice for direct chiral separation. The aim of this work was to provide a brief review of direct chiral separations of racemic pharmaceuticals using liquid chromatography that have been published in the last period. Acknowledgements This work was supported by the Scientific Grant Agency VEGA of the Ministry of Education, Research, Development and Youth of the Slovak Republic and the Slovak Academy of Sciences (Grant No. 1/0177/23). References G.K.E. Scriba, Trends Anal. Chem. 120 (2019) 115639. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 19 SESSION 1 ANALYTICAL CHEMISTRY Mixed Micelles Cloud Point Extraction for Sensitive Spectrophotometric Determination of Two Transition Elements A. Gajdosovaa*, J. Sandrejovaa, V. Divarovab, K. Gavazovb a Department of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 041 54 Košice, Slovakia b Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, Bulgaria *andrea.g[email protected]js.sk Vanadium and molybdenum belong among transition metals. Vanadium is used in various industries while molybdenum is an essential element, playing a role in enzyme production. Both of them have a positive effect on human organism, therefore they are available in the form of dietary supplements. They also occur naturally in several types of food or water sources. However, in higher concentrations, they are toxic. Because of both negative and positive effects, it is important to monitor vanadium and molybdenum levels in samples of their source. In cloud point extraction (CPE), a non-ionic surfactant serves as an extraction reagent. Under certain conditions, surfactant creates micelles that have the ability to encapsulate the analyte and separate it from the aqueous solution. Mixed micelles cloud point extraction (MM CPE) is a variant in which an additional ionic surfactant is used. The ionic surfactant possesses the ability to bind to the ionic complex containing the analyte, resulting in the creation of a ternary complex. For V(V) analysis, an ionic surfactant cetylpyridiniumchloride was added into the solution, for the determination of Mo(VI), Aliquat® 336 was used. MM CPE for the determination of V(V) and Mo(VI) was performed using 4-nitrocatechol as a complexing reagent with the addition of the respective ionic surfactant. The solutions were first incubated and then kept in a freezer to ensure micelles formation and separation in the form of a surfactant rich phase (SRP) at the bottom of the solution. After the aqueous phase was disposed of, the SRP was diluted with ethanol and distilled water. In this state, it was suitable for spectrophotometric detection. Absorbance measurements at 670nm for V(V) and 435nm for Mo(VI) were performed. The limit of detection values reached 0.6 and 3.2 mg L−1 for V(V) and Mo(VI), respectively. V(V) and Mo(VI) were determined in real samples of mineral water, dietary supplements, catalyst (V(V)), and steel (Mo(VI)). The implementation of the ionic surfactant for the MM CPE resulted in higher absorbance signals and therefore a more sensitive determination [1, 2]. Acknowledgements The work was supported by research project financed by Ministry of Education, Research, Development and Youth of the Slovak Republic (VEGA 1/ 0142/25). References [1] A. Gajdošová, P. Racheva, D. Kiradzhiyska, V. Divarova, A. Saravanska, J. Šandrejová, K. Gavazov, Int. J. Mol. Sci. 26 (2025) 5808. [2] V. Divarova, A. Gajdošová, P. Racheva, K. Gavazov, Int. J. Mol. Sci. 26 (2025) 4597. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 20 SESSION 1 ANALYTICAL CHEMISTRY Monitoring of polyphenolic compounds in berry fruits N. Icsovaa*, K. Reiffovaa aDepartment of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01, Košice, Slovak Republic *nikolett.icsov[email protected]js.sk Polyphenols are secondary plant metabolites that contain at least one aromatic ring and one or more hydroxyl groups. They are considered important dietary antioxidants, often exhibiting higher efficacy than vitamins C or E. These compounds may exert strong protective effects against cellular oxidative damage, and act both directly and indirectly against oxidative stress. Studies suggest that a diet rich in polyphenols may offer protection against coronary heart disease and lung cancer. Dietary intake of flavonoids has been shown to reduce the incidence of prostate cancer. Berry fruits are known to have the highest content of polyphenols, with a wide range of phenolic subclasses, primarily flavonoids and phenolic acids [1, 2]. In this work, the content of polyphenolic compounds will be determined in selected types of berry fruits: chokeberry, blackcurrant, lingonberry, elderberry, blueberry, cornelian cherry and pokeweed. Two forms of fruit will be compared – fresh berries and berries dried at 40 °C. Ultrasound-assisted extraction will be used, carried out for 30 minutes in an ultrasonic bath at laboratory temperature. Samples will be extracted using 50% methanol, then filtered using a vacuum pump or centrifuged for 10 minutes at 9000 rpm. The analysis will focus on selected phenolic acids – chlorogenic acid, gallic acid, caffeic acid, trans-ferulic acid – and one flavonoid, catechin. High-Performance Liquid Chromatography (HPLC) with UV detection at a wavelength of 254 nm will be used for quantification. Separation of analytes will be performed on an ACE C18 column (250 x 4,6 mm; 5 μm). The mobile phase will consist of acetonitrile-water-acetic acid in a ratio of 10:89:1 (v/v/v). Elution will be carried out in isocratic mode with a flow rate of 1.0 ml.min-1. References [1] N. Ćuji, N. Kardum, K. Šavikin, G. Zduni, T. Jankovi, N. Menkovi, Chapter 7 - Potential of Chokeberry (Aronia Melanocarpa L.) as a Therapeutic Food in: Therapeutic Foods, Vol. 8. Academic Press, London, (2018) pages 209-211. [2] E. Laczkó-Zöld, A. Komlósi, T. Ülkei, E. Fogarasi, M. Croitoru, I. Fülöp, E. Domonkos, R. Ștefănescu, E. Varga, Acta Biologica Hungarica 69 (2) (2018) 156-169. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 21 SESSION 1 ANALYTICAL CHEMISTRY Fluorescent Determination of Perchlorates Using Vortex-Assisted Liquid–Liquid Microextraction S. Kubackovaa*, P. Bezega, Y. Bazela aDepartment of Analytical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] Perchlorate (ClO4–) represents a significant endocrine disruptor and an emerging environmental contaminant that can threaten both human health and ecosystems [1]. Due to its extensive industrial applications-particularly in solid rocket fuels, fireworks, explosives, pyrotechnics, batteries, and paints-perchlorate ions are released into the environment from multiple sources [2,3]. Their high solubility in water and improper disposal of materials containing perchlorate salts contribute to widespread contamination of surface and groundwater, as well as to accumulation in plants and the food chain. Human exposure to perchlorate mainly occurs through water, food, and plants. It competes with iodide for thyroid uptake via the sodium-iodide symporter, disrupting hormone synthesis and potentially causing hypothyroidism [4–6]. Despite growing knowledge about the global occurrence of perchlorate, legislative frameworks for its regulation remain insufficient in many countries [7]. These facts highlight the need for developing effective methods to limit the presence of perchlorate in the environment and reduce its negative impact on health. The main objective of this study was to develop a new, highly sensitive, and selective method for the fluorescent determination of perchlorate based on vortex-assisted liquid–liquid microextraction (VALLME). The dye 1,1′,3,3,3′,3′-hexamethylindodicarbocyanine iodide (HIDC) was used as a complexing agent. In the initial phase of the research, the possibility of forming an ion associate (IA) between perchlorate and the dye 1,1′,3,3,3′,3′- hexamethylindocarbocyanine chloride (Astrafloxine) was also investigated; however, experimental results showed that this dye was not suitable under the selected experimental conditions, and further optimization was therefore carried out using HIDC. The developed method is based on the formation and extraction of an IA between the perchlorate anion and HIDC dye, with the fluorescence signal recorded at an excitation wavelength of 640 nm and an emission maximum of 666 nm. During the method development, both chemical and physical parameters of the experiment were optimized to achieve maximum fluorescence signal intensity and extraction efficiency. The optimized conditions included an HIDC concentration of 1.5 × 10–6 M, 0.5 mL of buffer at pH 6, 500 µL of n-amyl acetate as the extraction solvent, a vortexing time of 15 s at 1600 rpm, and centrifugation for 2 minutes at 3000 rpm. Under these conditions, a linear signal response was obtained in the range of 8–150 µg L–1 (R2 = 0.9977), with a detection limit (LOD) of 2.53 µg L–1. The efficiency of the microextraction process was characterized by a preconcentration factor (PF = 10). The proposed method is characterized by high sensitivity, selectivity, simplicity, and low consumption of organic solvents, making it suitable for environmental analyses in accordance with the principles of green analytical chemistry. Acknowledgements Yaroslav Bazeľ and Sofia Kubáčková thank the Scientific Grant Agency VEGA of the Ministry of Education, Research, Development and Youth of the Slovak Republic and the Slovak Academy of Sciences for their support (Grant no. 1/0177/23). References [1] C. Serrano-Nascimento, M.T. Nunes, Front. Endocrinol. 13 (2022) 1–8. [2] S.P. Kounaves et al., Environ. Sci. Technol. 44 (2010) 2360–2364. [3] S.D. Richardson, Anal. Chem. 81 (2009) 4645–4677. [4] T. Zhang, Q. Wu, H.W. Sun, J. Rao, K. Kannan, China, Environ. Sci. Technol. 44 (2010) 6947–6953. [5] J. Wolff, Pharmacol. Rev. 50 (1998) 89–105. [6] C.C. Capen, Toxicol. Pathol. 25 (1997) 39–48. [7] W.A. Jackson et al., Geochim. Cosmochim. Acta 164 (2015) 502–522. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 22 SESSION 1 ANALYTICAL CHEMISTRY Analytical evaluation of PAH degradation during the cultivation of hydrocarbonutilizing bacteria with bioremediation potential E. Kupcovaa*, J. Sevcikovab, V. Krempaskac, M. Vestegc, M. Murgasovac, P. Guziurovad a Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovakia b Department of Technology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovakia c Department of Biology and Environmental Studies, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovakia d Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkyňova 464, 612 00 Brno, Czechia *[email protected] Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants characterized by high toxicity and low biodegradability [1]. In this study, bacterial strains capable of utilizing PAHs [2,3] were isolated from various extreme environmental habitats. The isolates were cultivated in mineral media supplemented with selected PAHs (specifically fluorene and phenantrene) as the sole carbon source and exposed to a range of concentrations to determine the maximum levels that the bacteria were able to utilize. The degradation efficiency was assessed by monitoring the residual concentrations of the target compounds using high-performance liquid chromatography with diode array and fluorescence detection (HPLC-DAD/FLD). The results revealed that several bacterial strains exhibited a remarkable ability to degrade specific PAHs even at elevated concentrations, highlighting their potential application in bioremediation of contaminated environments. Acknowledgement Funded by the EU NextGeneration EU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00009. References [1] J. Teixeira, C. Delerue-Matos, S. Morais, M. Oliveira, Environ. Sci. Pollut. Res. 31 (2024) 54339-54362. [2] C. Lu, Y. Hong, J. Liu, Y. Gao, Z. Ma, B. Yang, W. Ling, M. G. Waigi, Environ. Pollut. 251 (2019) 773-782. [3] J. Li, W. Peng, X. Yin, X. Wang, Z. Liu, Q. Liu, Z. Deng, S. Lin, R. Liang. J. Hazard. Mater. 465 (2024) 133138. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 23 SESSION 2 BIOCHEMISTRY Decoding the Structural Signatures Driving Amyloid Modulation B. Borovskaa*, Z. Bednarikovaa, L. Mab, M. Gancara, R. Wangb, Z. Gazovaa a Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Košice, Slovakia b Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd., 200237 Shanghai, China *borov[email protected] Protein aggregation into amyloid fibrils represents a hallmark of numerous human disorders, including Alzheimer’s disease (Aβ42 peptide) and systemic amyloidosis. Despite differences in their amino acid sequences and native conformations, these fibrils share a characteristic cross-β-sheet structure, making them compelling targets for small-molecule modulators [1]. Coumarins derivatives exhibit diverse biological activities, including anti-amyloid, antioxidant, and enzyme-inhibitory effects [2]. Understanding which structural motifs drive these activities can accelerate the development of potent derivatives and inform rational design strategies. In this study we performed structural and functional analysis of six synthetic compounds (M1–M6) and compare their activity with previously investigated coumarin derivatives - namely bis-coumarins - connected via 4and 7carbon alkyl linkers (BCD4 and BCD7), and the mono-coumarin derivative - umbelliferone (MCD). The goal was to identify structural motifs underlying the inhibitory potential of studied compounds against Aβ42 peptide amyloid aggregation by combining machine learning analysis together with experimental assays. Thioflavin T (ThT) fluorescence assays revealed diverse effects among M-compounds: while M3 inhibited Aβ42 peptide amyloid fibril formation, M1, M2, M4, and M5 displayed modest inhibition, and M6 unexpectedly promoted aggregation. These findings were confirmed by atomic force microscopy (AFM). Computational analysis linked the observed activities to specific structural features. Although M1, M2, and M3 all contained the key structural motifs previously associated with inhibitory potential, their effects on Aβ42 peptide aggregation differed markedly. These suggest that the mere presence of these motifs is not sufficient for activity, rather, their special arrangement, linker flexibility, and electronic properties determine whether a compound effectively interferes with fibril formation. M3, combining optimal orientation of polar substituents and aromatic moieties, exhibited inhibitory activity, while M1 and M2, despite containing similar motifs, showed only weak effects. Conversely, halogenated and less polar motifs in M6 might facilitate fibril nucleation and possibly stabilize βsheet stacking, consistent with its aggregation promoting behaviour observed in ThT assays, and atomic force microscopy. When compared with the previously characterized bis-coumarin derivatives BCD4 and BCD7, which exhibited strong anti-amyloid activity, the new M-series compounds follow a similar structure–activity pattern. Compounds retaining optimal linker length and balanced polarity, such as M3, maintained high inhibitory potential comparable to BCD7, whereas others deviating from this motif (e.g. M6) lost activity or even promoted aggregation. By integrating motif-level analysis with ThT fluorescence data and AFM imaging, this study provides valuable insights into the structure–activity relationships governing coumarin-based modulators of amyloid aggregation and highlights structural features that can guide the design of more potent inhibitors. Acknowledgements This work was supported by the Slovak Research and Development Agency under the Contract no. APVV-SKCN-23-0025, APVV-22-0598 and APVV-18-0284; Slovak Grant Agency VEGA 2/0141/25 and the National Natural Science Foundation of China (Grant 82173746). References [1] C. Soto, “Unfolding the role of protein misfolding in neurodegenerative diseases,” Nat. Rev. Neurosci., vol. 4, no. 1, pp. 49–60, 2003, doi: 10.1038/nrn1007. [2] A. Frydman-Marom, R. Shaltiel-Karyo, S. Moshe, and E. Gazit, “The generic amyloid formation inhibition effect of a designed small aromatic β-breaking peptide,” http://dx.doi.org/10.3109/13506129.2011.582902, vol. 18, no. 3, pp. 119–127, Sep. 2011, doi: 10.3109/13506129.2011.582902. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 24 SESSION 2 BIOCHEMISTRY Development of LOV2 domain as genetically encoded photosensitizer K. Felcikovaa*, A. Hovana, G. Banoa, E. Sedlakb,c a Department of Biophysics, Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University in Košice, Jesenná 5, 040 01 Košice, Slovakia b Center for Interdisciplinary Biosciences, Technology and Innovation Park, Pavol Jozef Šafárik University in Košice, Jesenná 5, 040 01 Košice c Department of Biochemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice *kristina.felciko[email protected]pjs.sk Flavin mononucleotide (FMN) belongs to a group of efficient photosensitizers with a high quantum yield of singlet oxygen (1O2) production [1]. However, due to its lack of selectivity toward diseased tissue, FMN needs to be attached to a specific carrier that can be targeted. One such protein containing FMN is the Light-Oxygen-Voltage (LOV) domain 2 from Avena sativa. Previous studies have revealed that when FMN is incorporated into a protein, its surroundings strongly affect the efficiency of 1O2 production [2]. Our approach to design new genetically encoded photosensitizers relies on FMN dissociation caused by the oxidation of amino acids at the FMN binding site. An important part of this approach was to propose mutations that, upon irradiation with light and subsequent oxidation, increase the volume of the mutated amino acids and trigger FMN dissociation without destabilizing the protein structure. After analyzing the FMN binding site, we designed, expressed, and purified three different LOV2 domain mutants: V416C, T418C and V416CT418C. We measured their 1O2 phosphorescence and the results demonstrated an increased efficiency of 1O2 production, supporting our approach. Results from fluorescence measurements confirmed that after irradiation, FMN was effectively released into the solution [3]. Figure 1 Time-resolved singlet oxygen phosphorescence of the LOV2 domain of Avena sativa (AsLOV2) variants, with the same scaled y-axis for all plots. The color scheme represent the following accumulated incident energy: black open squares 0.2 J, red open circles 0.8 J, blue triangles 1.4 J, green reverse triangles 2 J, purple diamonds 2.6 J, and yellow ochre left triangles 3.2 J [3]. Acknowledgements This research was funded by the Slovak Research and Development Agency (project APVV-20-0340) and by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I02-03V01-00021. References [1] M. Westberg, M. Bregnhoj, M. Etzerodt, P.R. Ogilby, J. Phys. Chem. B 121 (2017) 2561-2574. [2] M. Petrenčáková, F. Filandr, A. Hovan, et al., Sci. Rep. 10 (2020) 4119. [3] K. Felčíková, A. Hovan, M. Polák, et al., Prot. Sci. 33 (2024) 4921. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 25 SESSION 2 BIOCHEMISTRY Interaction of a quinacrine analog with different polynucleotides: A noticeable preference towards a triplex RNA structural motif A. Guckya*, A. Mihokovaa, E. Scalzib, J. Rosinskaa, J. Korabecnyc, M. Kozurkovaa a Department of Biochemistry, Institute of Chemical Sciences, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic b Department of Pharmacy, University of Pisa, Via Bonnano Pisano 12, 561 26 Pisa, Italy c Biomedical Research Center, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic *adrian.g[email protected] Low-molecular-weight ligands represent some of the most promising drug candidates in modern chemotherapy due to their broad spectrum of pharmacological effects. Acridine derivatives belong to such molecules and are known for their ability to interact with all sorts of biomolecular targets, including various DNA and RNA structural motifs [1]. In the past years, long non-coding RNA (lncRNA) have gained considerable attention due to their crucial, yet mysterious role in gene expression and associated disease modulation. Some of these lncRNAs contain short triplex sequences, which are essential for their stability, catalytic activity or ligand binding [2]. Targeting these structural motifs with small molecules in order to destabilize them and disrupt their biological function could therefore prove to be a viable therapeutic strategy. A recent study of an acridine derivative revealed its ability to bind and destabilize poly(UAU) triplex structure [3], implying that such compounds represent promising candidates for further research of RNA triplex motifs and their interaction with small molecules. The present work has been focused on the interactions of a quinacrine analog A1 (Figure 1) with different DNA and RNA structural motifs, including double-stranded calf thymus DNA (ctDNA), single-stranded polyriboadenylic acid (polyA), double-stranded polyriboadenylic-polyribouridylic acid (polyAU) and a triplex poly(UAU) motif composed of a Watson-Crick poly(AU) duplex and a Hoogsteen poly(U) single strand. We have employed spectroscopic methods to probe whether the studied compound forms a complex with the tested polynucleotides and to determine the corresponding binding constants (Kb). Our results have proven that A1 binds to all four DNA/RNA motifs, as implied by the formation of isosbestic points in the absorption titration spectra and the associated hypochromic and bathochromic shifts typical for the interaction of small molecules with nucleic acids. Interestingly, we observed notable differences in the binding constants (Figure 1), implying a binding preference of A1 towards the poly(UAU) triplex motif (Kb = 6,40 × 104 mol-1.dm3) as opposed to the other polynucleotides (Kb = 0,66 – 2,37 mol-1.dm3). These findings provide basic foundations for further research of the compound’s ability to selectively interact with triplex RNA structures in the hope of discovering novel triplexbinding ligands. Figure 1 Chemical structure of compound A1 and Kb values for its interaction with tested polynucleotides. Acknowledgements Financial support for this study was provided by VEGA Grant no. 1/0037/22 and is gratefully acknowledged. References [1] M. Kožurková, D. Sabolová, P. Kristian, J. Appl. Toxicol. 41 (2021) 175-189. [2] J. A. Brown, WIREs RNA. 11 (2020) e1598. [3] K. Krochtová, L. Janovec, V. Bogárová, A. Halečková, M. Kožurková, Chem. Biol. Interact. 394 (2024) 110965. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 32 SESSION 2 BIOCHEMISTRY Study of new disubstituted diphenylamine derivatives with albumin and its antioxidant activity O. Ozhelevskaa*, L. Janovecb, M. Kozurkovaa a Department of Biochemistry, Institute of Chemical Sciences, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic b Department of Organic chemistry, Institute of Chemical Sciences, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic * oksana.ozhelev[email protected] Diphenylamine (DFA) derivatives exhibit a wide range of biological activities and hold a special place in pharmacology, especially as nonsteroidal anti-inflammatory agents (NSAID). Evidence indicates that the bioactivation of haloaromatic drugs into reactive quinone metabolites is a key factor contributing to hepatotoxicity. Predictions suggest that DFA may also undergo bioactivation, resulting in the formation of reactive quinone metabolites [1]. Their structure consists of two aromatic rings connected by a secondary amine [1]. This determines their pronounced anti-inflammatory [1], antimicrobial [2] and antitumor [3]. DFA derivatives possess strong fungicidal, insecticidal, acaricidal, rodenticidal, and/or herbicidal effects [4]. They may also exhibit antifosphorylating [5] and antioxidant activity [6]. DFA are largely capable of binding to serum proteins, such as human serum albumin (HSA) [7]. HSA functions as a carrier of metabolites and xenobiotics in human blood. Studying the binding of this transport protein with DFA can provide insight into its bioavailability [8]. The study focuses on the investigation of disubstituted DFA derivatives and their antioxidant and antibacterial activities. Emission spectra confirmed the binding of the examined diphenylamine derivatives to HSA. Acknowledgements Financial support for this study was provided by VEGA Grant no. 1/0037/22 and is gratefully acknowledged. References [1] M. A. Schleiff, et al. Toxicol. 458 (2021) 152832. [2] S. Aviral, et al. J. Mol. Struct. 1311 (2024) 138379. [3] Y. Xiang-Yu, et al. Eur. J. Med. Chem. 237 (2022) 114372. [4] A. Kumar, A. K. Mishra. J. Pharm. Bioallied Sci. 7 (2015) 5–81. [5] M. A.-S. Sahar. Eur. J. Med. Chem. 45 (2010) 4113–4121. [6] M. Govindaraj, M. K. Muthukumaran, P.-C. Tsai, K. Prakasham, G. Andaluri, M. Eswaran, V. K. Ponnusamy, A. Selvi J. Food Chem. 495 (2025) 146387. [7] J.-M. Chamouard, et al. Biochem. Pharmacol. 34 (1985) 1695–1700. [8] N. Shohreh, P. Ataollah, B. S. Golshan. In: Journal of Luminescence. 123 (2012) 2361-2366. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 33 SESSION 2 BIOCHEMISTRY Destruction of Insulin Amyloid Fibrils by Phytoalexins with Added Antioxidant Benefit O. Parmara*, H. A. Kareema, A. Antosovaa, M. Budovskab, Z. Bednarikovaa, Z. Gazovaa aDepartment of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia bInstitute of Chemistry, Faculty of Sciences, P. J. Safarik University, Kosice, Slovakia *[email protected] Insulin is a peptide hormone that regulates blood glucose levels. It is an essential therapy for type 2 diabetes. However, long-term injections may result in insulin localized amyloidosis. The disease is characterized by the accumulation of insulin amyloid fibrils at the injection site and can disrupt glucose regulation [1]. Phytoalexins are chemical compounds produced by plants under stress, resulting from exposure to pathogens or physical damage. Their synthesis is a crucial element of the plant's built-in immune system. Several studies revealed antioxidant, anti-inflammatory, anticancer, metabolic, neuroprotective and antimicrobial actions of phytoalexins, making them an attractive topic of interest [2]. The objective of our study was to investigate the destructive effects of nine indole-based phytoalexins (Phy) and their synthetic derivatives on pre-formed human insulin amyloid fibrils in vitro. The destruction effect was examined using Thioflavin T (ThT) and Nile Red fluorescence assays, atomic force microscopy (AFM), and circular dichroism (CD) spectroscopy. Initial screening performed by the ThT and Nile Red fluorescence assays identified three phytoalexins — Phy 7, Phy 9, and Phy 11 — as strong fibril-destructors. The results of concentration-dependent studies showed that Phy 7 was the most potent compound with the highest destruction potential. The DC₅₀ value (concentration of phytoalexins that decreases the fluorescence intensity of amyloid fibrils by 50 %) was below 22 μM, followed by DC₅₀ values determined for Phy 11 (91 μM) and Phy 9 (157 μM). A treatment of pre-formed insulin fibrils with Phy 7, Phy 9 and Phy 11 resulted in a significant reduction in β-sheet content, as confirmed by far-UV CD spectroscopy. AFM confirmed the destructive activity of Phy 7, Phy 9 and Phy 11, where fewer and smaller amyloid fibrils were observed after treatment with the Phy. Importantly, cytotoxicity assessment revealed that Phy 7 and Phy 11 showed no toxicity toward HEK-293 cells at the tested concentrations (10 μM, 100 μM, 200 μM). On the other hand, Phy 9 showed cytotoxicity already at 100 μM. In the DPPH assay, all three effective Phy exhibited lower radical-scavenging capacity than gallic acid (used as a standard) at equivalent concentrations. Phy 9 and Phy 11 showed the significant antioxidant activity among the tested derivatives, corresponding to ~ 45% (Phy 9) and ~ 33 % (Phy 11) of the activity of gallic acid. Phy 7 exhibited only ~ 16 % of the antioxidant activity of gallic acid. In conclusion, this study identified several promising phytoalexin candidates, particularly Phy 7 and its bis-indolyl derivative, Phy 11, as potent, non-cytotoxic agents for disrupting insulin amyloid fibrils and exhibiting significant antioxidant effects. These findings demonstrate that indole phytoalexins offer a promising strategy to modulate effects associated with long-term insulin therapy. Acknowledgements This work was funded by the EU Next Generation EU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V02-00039, and by research grants from the Slovak Research and Development Agency under the Contract No. APVV-22-0598, and Slovak Grant Agency 02/0164/22, 02/0141/25, 01/0347/23, 1/0037/22. References [1] K. Pounot et al., Zinc determines dynamical properties and aggregation kinetics of human insulin; in: Biophysical Journal, Vol. 120, Pages 886–898. [2] S. Kaur et al., How do plants defend themselves against pathogens-Biochemical mechanisms and genetic interventions; in: Physiol Mol Biol Plants, Vol. 28, pages 485–504. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 34 SESSION 2 BIOCHEMISTRY Functional targeted delivery of flavin mononucleotide by DARPin and AsLOV2 C450A protein to breast cancer cells A. Poliakovaa,b*, T. Gulyasovaa,b, L. Ambrob, S. Tomkovab, M. Nemerguta,b E. Sedlakb,c, V. Huntosovab,d a,bUniverzita Pavla Jozefa Šafárika v Košiciach, Prírodovedecká fakulta, Katedra biofyziky, Košice; a,bUniverzita Pavla Jozefa Šafárika v Košiciach, Centrum interdisciplinárnych biovied, Technologický a inovačný park, Košice cUniverzita Pavla Jozefa Šafárika v Košiciach, Prírodovedecká fakulta, Katedra biochémie, Košice, dCentrum biovied Slovenskej akadémie vied, v. v. i , Ústav biochémie a genetiky živočíchov, Bratislava, Slovenská republika *[email protected] One of the major challenges in modern oncology is to develop therapeutic strategies that selectively target cancer cells while minimizing damage to healthy tissues. A promising approach involves receptor-specific targeting, such as the HER2 receptor frequently overexpressed on the surface of breast cancer cells [1]. Our research focused on developing protein conjugates for potential use in photodynamic therapy (PDT). This is a minimally invasive treatment that uses light-activated photosensitizers to destroy cancer cells. As a core component, we employed the genetically modified variant AsLOV2 C450A, which produces singlet oxygen upon blue-light illumination and binds its flavin mononucleotide (FMN) cofactor more tightly than the wild-type protein [2]. To achieve specific binding to HER2 receptors, AsLOV2 C450A was fused with Designed Ankyrin Repeat Proteins (DARPins). The recombinant fusion proteins were expressed in E. COLI. Conjugates were purified by HPLC and their molecular mass was confirmed using SDS-PAGE. Differential scanning calorimetry showed melting temperature and thermal stability of proteins. FMN was detected by its absorption and emission maxima with UV/VIS spectroscopy. Results provided by confocal microscopy indicate selective binding of the DARPin–AsLOV2 C450A conjugate to HER2positive cells, highlighting its potential as a targeted photosensitizing platform for future use in photodynamic treatment of breast cancer. Acknowledgements This work was supported by the EU NextGenerationEU through the Recovery and Resilience Plan of the Slovak Republic under project no. 09I03-03-V04-00007, by project vvgs-2025-3481. References [1] Jost, Ch., et al. "Structural basis for eliciting a cytotoxic effect in HER2-overexpressing cancer cells via binding to the extracellular domain of HER2." Structure 21.11 (2013): 1979-1991. [2] Petrenčáková, M., et al."Conformational properties of LOV2 domain and its C450A variant within broad pH region." Biophysical chemistry 259 (2020): 106337. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 35 SESSION 2 BIOCHEMISTRY Stability effect of FMN on flavin proteins miniSOG and SOPP3 N. Tomaskovaa*, A. Poliakovab, K. Felcikova, M. Nemergutb, E. Sedlaka,b aDepartment of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 04154 Košice, Slovakia bCenter for Interdisciplinary Biosciences, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia *natasa.tomasko[email protected] MiniSOG (Mini Singlet Oxygen Generator) is flavoprotein derived from LOV-domain of phototrophin 2 in Aradopsis thaliana 1. It is monomeric protein composed from 106 amino acids, Mw 15,3 kDa, containing strongly bound flavin mononucleotide (FMN). MiniSOG belongs to genetically encoded photosensitizers, which were developed for precise spatio-temporal control of ROS production withing living cells and organisms. SOPP3, variant of the miniSOG, was made for improving their photosensitizer properties 2. Genetically encoded photosensitizers are promising tool for selective non-invasive photodynamic therapy of cancer due to the spatial selectivity and locality of destructive action compared to other methods of oncotherapy. In the present study we use differential scanning calorimetry (DSC) to analyze effect of FMN on stabilization of miniSOG and SOPP3 as well as their T100C mutants. Ongoing studies show that miniSOG, which is known as less potent photosensitizer, has higher thermal stability (Tm = 52 C) compared to its variant SOPP3 (Tm = 45 C). The introduction of the T100C mutation into these proteins was shown to have an even greater destabilizing effect according to spectrometric and DSC measurements and affected the binding of FMN to the protein itself. By adding FMN in DSC thermal stability measurements of the proteins and mutants at different ratios, it was shown that the FMN increases the stability of proteins (Figure 1). Figure 1 DSC analysis of effects of FMN on miniSOG, SOPP3 and their T100C mutants. Rations 1:2, 1:4 and 1:10 are rations of protein:FMN. According to our study, the ability to more easily release the FMN group due to mutations to create a more potent photosensitizer has a significant impact on protein stability. At the same time, stability of flavin proteins itself depends on the affinity of FMN to the polypeptide chain. These results are in accordance with previous results with LOV2 domain (Felčíková et al., 2023). Acknowledgements This work was supported by the research grant provided by Slovak Research and Development Agency grant APVV 20-0340, and supported by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09-I02-03-V01-00021. References [1] W. A. Souslova, K. E. Mironova, S. M. Deyev, J. Biophotonics 10 (2017) 338-352. 2 M. Westberg, M. Bregnhoj, M. Etzerodt, P.R. Ogilby, J. Phys. Chem. B 121 (2017), 9366-9371. 0 5 10 15 20 WT 1:2 1:4 1:10 ∆Cp (kJ/mol/K) miniSOG wt miniSOG T100C SOPP3 wt SOPP3 T100C Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 36 3 K. Felčíková, A. Hovan, M. Polák, D. S. Loginov, V. Holotová, C. Díaz, T. Kožár, O-S. Lee, R. Varháč, P. Novák, G. Bánó, E. Sedlák, Protein Science 33 (2024), e4921. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 37 SESSION 2 BIOCHEMISTRY Visualization HER2 positive cells with NanoLuc S. Tomkovaa*, M. Nemerguta, E. Sedlaka,b, V. Huntosovaa aCenter for Interdisciplinary Biosciences, Technology and Innovation Park, Pavol Jozef Šafárik University in Košice, Jesenná 5, 041 54 Košice, Slovak Republic b Department of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 041 54 Košice, Slovak Republic *silvia.tomkov[email protected] Oxidation of the luciferin substrate leads to the emission of light called luminescence. The catalysis oxygenation of the luciferin pigment allows oxidoreductases, named luciferases. Very innovative and structurally optimized type of luciferase is NanoLuc. The NanoLuc luciferase technology has been successfully utilized for several applications, including the investigation of protein – protein and protein – ligand interactions, exploring gene regulation and cell signaling, monitoring protein stability, utilization as BRET-based biosensors, and bioluminescence imaging [1, 2]. One of most problems which are discussed is limited light penetration into tissues. The application of internal light sources, based on chemiluminescence or bioluminescence of some molecules in the presence of a suitable substrate or catalyst, represents approach which can resolve problem with light penetration. Very elegant delivery system, which allows increasing of specificity, are DARPins. DARPins are specifically designed ankyrin repeat proteins that typically exhibit high binding affinity to the targeted protein/receptor. A DARPin-Luciferase complex (NanoLuc) has been designed and created with high specificity for the HER2 receptor. The HER2 is a protein/receptor localized on the surface of some cancer cells and has tyrosine kinase activity. HER2 can initiates signaling cascades that lead to cell growth and proliferation after activation. This receptor is a significant therapeutic target for anticancer treatments designed to inhibit its signaling pathways. A tumor is considered "HER2-positive" if it has an amplification of the HER2 gene, overexpression of the HER2 protein, or certain mutations in the gene, which all result in overly active HER2 signaling. Traditional treatments for HER2positive cancers aim to block HER2 signaling by using monoclonal antibodies, tyrosine kinase inhibitors, or antibody-drug conjugates. Our results suggest that it is possible to use specifically modificated DARPin with NanoLuc for visualization of “HER2 positive “ cells. Acknowledgments This research is funded by the Ministry of Education, Science, Research and Sport of the Slovak Republic VEGA : 1/0216/25, university project VVGS 2025-3747, and by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project BCOrgFluorIDA No. 09I03-03-V04-00007. References [1] England CG, Ehlerding EB, Cai W. NanoLuc: A Small Luciferase Is Brightening Up the Field of Bioluminescence. Bioconjug Chem. 2016 May 18;27(5):1175-1187. doi: 10.1021/acs.bioconjchem.6b00112. Epub 2016 Apr 19. PMID: 27045664; PMCID: PMC4871753. [2] Nemergut, M., Pluskal, D., Horackova, J. et al. Illuminating the mechanism and allosteric behavior of NanoLuc luciferase. Nat Commun 14, 7864 (2023). https://doi.org/10.1038/s41467-023-43403-y Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 38 SESSION 2 BIOCHEMISTRY Determination of biologically interesting substances from natural materials using UV/Vis and HPLC methods A. Uhrinovaa*, L. Ungvarska Maluckaa,b aUniversity of Veterinary Medicine and Pharmacy in Košice, Department of Chemistry, Biochemistry and Biophysics, Komenského 73, 041 81 Košice, Slovak Republic bMasaryk University, Faculty of Pharmacy, Department of Chemical Drugs, Palackého třída 1946/1, 612 00 Brno, Czech Republic *[email protected] Recently, a great interest has been focused on the use of anthocyanins in the nutraceutical industry as functional food sources for their sorts of potential health benefit, including anti-inflammation, anticancer, anti-mutagenesis, and anti-bacterium. Anthocyanins also possess the effect on reducing the risks of heart disease, preventing Alzheimer’s disease, decreasing blood glucose and DNA damage, as well as regulating the immune system and improving visual. These above health contributions mainly attribute to the antioxidant activity and free radical scavenging property of anthocyanins [1]. UV/Vis spectrophotometry is a quantitative analytical technique that measures the amount of light a chemical compound absorbs in the ultraviolet and visible ranges of the electromagnetic spectrum. This method is widely used across various fields like chemistry, biology, environmental science, and material science due to its sensitivity and versatility. An HPLC method is an analytical technique that separates, identifies, and quantifies components in a liquid mixture. High-performance liquid chromatography (HPLC) is the standard method for analyzing anthocyanins, a class of flavonoid pigments responsible for red, purple, and blue colors in plants. Due to their poor stability, analysis requires careful preparation and optimized HPLC conditions to prevent degradation [2, 3]. The aim of the study was to determine the anthocyanin content using UV/Vis spectrophotometry and HPLC analysis of blackberry (Rubus fruticosus L.) and fresh grapevine (Vitis vinifera L.) fruits. An ethanol solution acidified with 1% phosphoric acid was used as the extraction agent in the preparation of extracts from blackberries and grapevines. The prepared extracts were purified using Amberlite XAD-7 with distilled water acidified with hydrochloric acid and followed by ethyl acetate as the mobile phase. When measuring UV/Vis spectra, the absorbance of the samples was measured at wavelengths of 520 nm and 700 nm. Distilled water was used as a blank sample. Cyanidin-3-glucoside was determined to be the basic component of anthocyanins. At a wavelength of 520 nm, the change in pigment absorbance is directly proportional to the concentration of these pigments. The absorbance of diluted samples was measured using an Agilent Technologies Cary 60 UV/Vis spectrophotometer. The anthocyanin (cyanidin-3-glucoside) content of the prepared grape and blackberry extracts was determined using a UHPLC Ultimate 300 (Thermo Scientific) instrument. The measurement was performed on a Polaris 5 C18-A column with dimensions of 250×4.6 mm. The mobile phase flow rate (acetonitrile with 0.5% formic acid) was set to 1 ml/min. and the thermostat to 20°C. The sample injection volume was 20 μl and the pressure was 150 bar. The UV detector (DAD) was set to a wavelength of 528 nm. Figure 1 Cyanidin-3-glucoside, a type of natural pigment called an anthocyanin, found in many dark-colored fruits and vegetables, which acts as a powerful antioxidant and anti-inflammatory agent [4]. The anthocyanin content in grapevine was 30.84 mg·dm-3 in purified extract. In wild blackberries, the anthocyanin content in the purified extract was 66.63 mg·dm-3. Based on qualitative HPLC analysis, it was confirmed that cyanidin-3-glucoside is present in extracts of grapevine and wild blackberries. References [1] M. Xin, A. Xu, J. Tian, L. Wang, Y. He, H. Jiang, B. Yang, B. Li, Y. Sun, Phytomedicine 132 (2024) 155889. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 39 [2] L. Guo, J. Qiao, Ch. Gong, J. Wei, J. Li, L. Zhang, D. Qin, J. Huo, Heliyon 9 (2003) e14685. [3] F. Lao, M. M. Giusti, Food Anal. Methods 9 (2016) 1367-1380. [4] J. Song, X. Li, L. Zeng, H. Liu, M. Xie, Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 12 (2011) 1645-56. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 40 SESSION 2 BIOCHEMISTRY Basic hydrolysis of chiral menthyl ester of (4S,5S)‐5‐(acridin‐4‐yl)‐3‐(2,4,6‐ trimethylphenyl)‐4,5‐dihydro‐1,2‐oxazole‐4‐carboxylic acid L. Ungvarska Maluckaa,b*, M. Vilkovac aUniversity of Veterinary Medicine and Pharmacy in Košice, Department of Chemistry, Biochemistry and Biophysics, Komenského 73, 041 81 Košice, Slovak Republic bMasaryk University, Faculty of Pharmacy, Department of Chemical Drugs, Palackého třída 1946/1, 612 00 Brno, Czech Republic cPavol Jozef Šafárik University, Faculty of Science, Institute of Chemistry, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] During this period, organic chemistry continued to develop, thanks to advances in technology and the need for new compounds, which led to their synthesis and applications in medicine, materials and many other areas. This field of chemistry also develops thanks to new experiments that result from the study of reaction mechanisms. Also in this work, a seemingly simple hydrolysis of an ester was studied, which, however, did not lead to the expected product, but provided completely new heterocyclic compounds. Basic hydrolysis of the acridine derivative 1 was carried out to probe their stability under strongly nucleophilic conditions, validate the proposed intermediate structures through conversion to predictable products, assess the retention or loss of stereochemical information during ring opening and rearrangement, and generate complementary derivatives for comparative stereochemical and mechanistic studies. The reaction of 1 with KOH released (1S,2R,5S)-(+)-menthol and furnished, not the carboxylic acid, but instead the corresponding isoxazolone derivatives as mixtures of the 2ZC4C6 and 2EC4C6 isomers in ratio 3.8:1.0 (based on 1H NMR spectrum of reaction mixture), as described previously [1]. Recrystallization from methanol afforded the mixture of the 2ZC4C6 and 2EC4C6, which were fully characterized by NMR spectroscopy. Figure 1 Basic hydrolysis of 1 leading to the formation of 2ZC4C6 and 2EC4C6isomers. The double bond at C4=C6 is the site of E/Z isomerism. Structural elucidation of 2ZC4C6 and 2EC4C6 using NMR spectroscopy. Selected key 1H and 13C NMR chemical shifts are summarized in the tables. The 1H NMR spectra of 2ZC4C6 and 2EC4C6 reveal notable differences attributable to the anisotropic effects of the acridine and phenyl rings, as well as substituent shielding. The relatively high chemical shift of H6 arises from the anisotropy of the acridine ring. In the 2E isomer (across the C4=C6 double bond), H1' and H2' exhibit decreased chemical shifts relative to the 2Z isomer, reflecting shielding by methyl groups and the phenyl ring, whereas H3' in 2Z is deshielded by the carbonyl group. H5' in 2Z experiences lower chemical shift due to methyl shielding. The E/Z assignment was confirmed via the 3JC5H6 coupling constant measured from 1H,13C-HMBC spectra. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 41 Acknowledgements The authors gratefully acknowledge the financial support provided by the KEGA (Scientific Grant Agency) under Grant No. 008UPJS-4/2023. References [1] L. Ungvarská Maľučká, M. Vilková, Molecules 29 (2024) 1-18. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 48 SESSION 4 INORGANIC CHEMISTRY Adsorption of Toxic Volatile Organic Vapors on HKUST-1: Structure–Property Correlations and Application in Gas Mask Filters K. Andrejeva, M. Zelinskaa, T. Zelenkab, M. Almasia* aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bDepartment of Chemistry, Faculty of Science, University of Ostrava, 30. Dubna 22, 702 00 Ostrava, Czech Republic *[email protected] Volatile organic compounds (VOCs) are a chemically diverse group of carbon-based molecules that readily evaporate at ambient temperatures and arise from industrial production, fuel combustion, solvent use, and everyday household activities. Their ubiquitous presence in indoor and outdoor air poses serious environmental and health risks, contributing to tropospheric ozone formation and causing respiratory or carcinogenic effects. Therefore, efficient VOC abatement remains a global priority. Conventional adsorbents such as activated carbon or zeolites, though widely used, often suffer from limited selectivity, poor adsorption of highly volatile molecules, and low regenerability. In contrast, metal–organic frameworks (MOFs) have emerged as next-generation sorbents due to their crystalline nature, tunable pore structure, and high surface area. Among them, HKUST-1 (Cu-BTC, or MOF-199) is particularly attractive for VOC capture because of its robust Cu paddle-wheel structure, large pores (6–9 Å), and high surface area (600– 1600 m² g⁻¹). Its low-cost synthesis and good thermal stability (up to 350 °C) make it a realistic candidate for scalable filtration technologies. In this work, the adsorption behaviour of HKUST-1 toward a representative set of VOCs: methanol, formaldehyde, benzene, toluene, pyridine, aniline, benzaldehyde, benzyl bromide, and salicylaldehyde, was systematically investigated to assess its potential for gas-mask filter applications. Activated HKUST-1 (150 °C, vacuum) was exposed to saturated vapors under static conditions, and adsorption capacities were determined gravimetrically after 3, 24, and 48 h to evaluate both fast and equilibrium uptake. The results revealed strong dependence on molecular size, polarity, and volatility. Rapid adsorption occurred within the first three hours, followed by stabilization or slight desorption. The framework displayed exceptionally high affinity for small, polar molecules: methanol uptake reached 1897 mg g⁻¹ (≈ 2 g adsorbate per g adsorbent) at 25 °C, and formaldehyde exhibited comparably strong sorption. In contrast, bulky VOCs such as benzyl bromide and salicylaldehyde showed limited diffusion into the pores, resulting in significantly lower capacities. Increasing temperature (35–45 °C) reduced uptake due to the exothermic nature of adsorption, but substantial sorption persisted, indicating good performance under realistic operational conditions. Overall, HKUST-1 demonstrates high capacity, stability, and partial selectivity toward low-molecular-weight polar VOCs, outperforming conventional carbons in terms of tunability and structural control. These results highlight HKUST-1 as a promising candidate for personal protective filters and broader air-purification applications. Future research should address cyclic regeneration, humidity tolerance, and composite design to further enhance its applicability in environmental protection and occupational safety. Acknowledgement: This work was supported by the VEGA project no. 1/0058/25. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 49 SESSION 4 INORGANIC CHEMISTRY Reinventing HKUST-1 Synthesis: A Comparative Insight into Sonochemical and Solvothermal Routes K. Andrejeva*, M. Almasia aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 041 54 Košice, Slovak Republic *kiril.an[email protected]pjs.sk HKUST-1 (also MOF-199 or CuBTC) is a metal-organic framework, that was first synthesized by Williams and co-workers in 1999. This material is well-known for its microporous structure containing Cu(II) paddle-wheel cluster and a favorable specific surface area. It is commonly used for CO2 capture, hydrogen storage, water purification and so on. A wide variety of synthetic routes for HKUST-1 have been developed. The solvothermal method remains the standard and most widely used approach. However, some methods are more energy-efficient, less time-consuming, and still deliver quality results. To illustrate, the mechanochemical method minimizes solvent usage, while the sonochemical method reduces energy consumption compared to its solvothermal counterpart. In this study, the synthesis of HKUST-1 is carried out using different methods while maintaining the same reaction mixture and reactants. The purpose is to compare the obtained materials in terms of their structural and textural properties and to evaluate their adsorption performance in the following experiments. In all HKUST-1 syntheses, the same reaction mixture was used. Specifically, 0.444 g of 1,3,5-benzenetricarboxylic acid was dissolved in 13.333 mL of a 1:1 DMF/ethanol mixture and added to 6.667 mL of an aqueous solution of 0.924 g of copper (II) nitrate trihydrate in a 30 mL glass vial. Depending on the type of synthesis, the resulting mixture in the vial was then processed under different conditions. Two different syntheses of HKUST-1 were carried out, namely solvothermal (ST) and sonochemical (SC) preparation. Both methods yielded crystalline HKUST-1 materials. The sonochemical route produced a higher amount of material. Although the solvothermal synthesis typically requires about 8 hours, shortening the reaction time to 160 minutes resulted in a significantly lower yield compared to the sonochemical method performed for the same duration (Figure 1). Based on the promising results of the solvothermal and sonochemical syntheses, a third route — microwaveassisted synthesis (MW-HKUST-1) — is planned to be explored. This approach is expected to further reduce the reaction time and energy consumption while providing uniform crystal formation. The synthesized materials will undergo adsorption experiments aimed at evaluating their sorption capacities toward selected adsorbates. The experiments will be conducted in a static system, monitoring mass changes to determine adsorption capacity and kinetics. Figure 1 a) Graphical representation of HKUST-1 sonochemical synthesis by time, b) Comparison of HKUST-1 sonochemical and solvothermal synthesis performance. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 50 Acknowledgements This work was supported by: VEGA 1/0058/25, VEGA 1/0442/25, EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the Project No. 09I02-03-V01-00022 (SUNFLOWERS), No. 09I03-03V03-00034 (MASS-PRAM) and No. 09I03-03-V05-00008 (VVGS-ESGV-2923). Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 51 SESSION 4 INORGANIC CHEMISTRY Mesoporous Silica Nanoparticles for Sustained Oral Delivery of Apixaban E. Benovaa*, N. Kiralya, M. Sulekovab, L. Vahovskab, V. Zelenaka a Pavol Jozef Šafárik University, Department of Inorganic chemistry, Moyzesova 11, 040 01, Košice, Slovakia. b University of Veterinary Medicine and Pharmacy in Košice, Department of Chemistry, Biochemistry and Biophysics, Komenského 73, 041 81, Košice, Slovakia *eva.ben[email protected] Mesoporous silica nanoparticles (MSNs) are attractive materials for controlled drug delivery because of their large surface area, tunable pore structure, and biocompatibility. In this study, spherical mesoporous silica nanoparticles (SMS) were synthesized and evaluated as carriers for the antithrombotic drug apixaban, a direct factor Xa inhibitor with poor aqueous solubility and short half-life [1]. The nanoparticles were prepared by a sol–gel process and functionalized with organic ligands (–SH, –NH₂, –Cl) to tailor surface interactions with the drug. TEM analysis confirmed uniform spherical morphology (~300 nm) and a well-ordered porous structure. N₂ adsorption–desorption isotherms displayed Type IV behaviour with a clear hysteresis loop, confirming mesoporosity. The BET surface area ranged from 300 to 600 m²·g⁻¹ with pore sizes of 3–5 nm, while TGA analysis verified successful surface modification and was used to estimate apixaban loading of 150–200 mg·g⁻¹ depending on functionality. Apixaban was incorporated using the wet impregnation method in methanol, which enabled efficient pore filling. In vitro release studies performed at pH 2 and pH 7.4 demonstrated sustained release over 72 hours, followed by a plateau. The release rate was slower in acidic conditions due to reduced drug solubility and stronger electrostatic interactions with the protonated silica surface. When a second portion of drug-loaded nanoparticles was added after 72 hours, the release process restarted, confirming the reproducibility of the system. These results highlight the potential of SMS mesoporous silica nanoparticles as effective carriers for poorly soluble antithrombotic drugs, capable of sustained release that could reduce dosing frequency and improve therapeutic safety. Figure 1 TEM images of SMS nanoparticles (average size: 300 nm) and release profiles of apixaban from nanoparticles in pH 7 and pH2. Acknowledgements This research was supported by the Recovery and Resilience Plan for Slovakia, project No. 09I03-03-V04-00722. References [1] M. Fralick, M. Colacci, S. Schneeweiss, K. F. Huybrechts, K. J. Lin, and J. J. Gagne, ‘Effectiveness and Safety of Apixaban Compared With Rivaroxaban for Patients With Atrial Fibrillation in Routine Practice: A Cohort Study’, Ann. Intern. Med., vol. 172, no. 7, pp. 463–473, Apr. 2020, doi: 10.7326/M19-2522. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 52 SESSION 4 INORGANIC CHEMISTRY Engineering MOF-Based Cathodes for Enhanced Stability and Capacity in Lithium– Sulfur Batteries D. Capkovaa, N. Kiralyb, A. Strakova Fedorkovac, M. Almasib* a Department of Chemical Sciences, Bernal Institute, University of Limerick, Limerick, Ireland b Department of Inorganic Chemistry, Pavol Jozef Safarik University in Kosice, Kosice, Slovak Republic c Department of Physical Chemistry, Pavol Jozef Safarik University in Kosice, Kosice, Slovak Republic *[email protected] Energy remains one of the most essential human needs and is the cornerstone of technological and societal progress. Since their commercialization in the early 1990s, rechargeable lithium-ion (Li-ion) batteries—featuring energy densities of approximately 200–400 Wh kg⁻¹ and 500–1300 Wh L⁻¹—have dominated the global market. Continuous advances in Li-ion technology have brought performance close to theoretical limits; however, current energy demands for electric vehicles, portable electronics, and large-scale storage systems already surpass the achievable capacities of Li-ion cells. This has accelerated the search for alternative energy-storage technologies with higher energy density, lower cost, and improved environmental compatibility. Lithium–sulfur (Li–S) batteries have emerged as one of the most promising next-generation systems. Unlike Liion batteries, which rely on the intercalation and deintercalation of lithium ions within layered structures, Li–S batteries operate via a multi-step conversion mechanism. During charge and discharge, elemental sulfur is electrochemically reduced to lithium polysulfides (Li₂Sₙ, 4 ≤ n ≤ 8), which are then converted to insoluble Li₂S. The reaction occurs at an average potential of approximately 2.1 V versus Li/Li⁺, corresponding to a high theoretical energy density of 2500 Wh kg⁻¹ and 2800 Wh L⁻¹—nearly an order of magnitude greater than that of conventional Li-ion systems. Despite these advantages, practical implementation of Li–S batteries faces several intrinsic challenges. Sulfur possesses extremely low electronic conductivity (~5 × 10⁻³⁰ S cm⁻¹), which limits charge transport and active material utilization. Furthermore, sulfur undergoes substantial volume expansion (~80%) upon lithiation, causing mechanical stress and electrode instability. The most critical issue is the polysulfide “shuttle effect,” where soluble lithium polysulfides migrate between the cathode and anode, leading to self-discharge, capacity fading, and poor Coulombic efficiency. To overcome these limitations, porous host materials capable of immobilizing sulfur species and maintaining electrical contact are being intensively investigated. Among them, metal–organic frameworks (MOFs) have attracted particular attention due to their tunable pore structure, high surface area, and chemical versatility. MOFbased cathodes can effectively confine polysulfides through physical adsorption and chemical interactions while providing conductive pathways for charge transport. Several representative MOFs, including MIL-101(Fe)-NH₂, MOF-76(Gd), and STAM-1, have been systematically studied as sulfur hosts. The amino-functionalized MIL-101(Fe)-NH₂ with a surface area of ~3500 m² g⁻¹ delivered an initial discharge capacity of 705 mAh g⁻¹ at 0.5 C and retained 476 mAh g⁻¹ after 200 cycles, corresponding to a low capacity fading rate of 0.162% per cycle. Similarly, carbonized MOF-76(Gd) exhibited an initial capacity of 658 mAh g⁻¹ and maintained 93% of its capacity after 200 cycles. The copper-based STAM-1 framework achieved a discharge capacity of 452 mAh g⁻¹ at 0.5 C and retained 430 mAh g⁻¹ after 100 cycles with a Coulombic efficiency of 97%. These results demonstrate that well-designed MOF architectures can efficiently stabilize the sulfur cathode, accommodate volume changes, and accelerate the conversion of sulfur intermediates. By improving electron/ion transport and suppressing polysulfide diffusion, MOFs substantially enhance the overall reversibility, rate capability, and long-term cycling stability of Li–S batteries. In summary, this study confirms that MOF-based sulfur hosts represent a viable strategy for developing highcapacity, durable, and cost-effective next-generation energy-storage systems. The insights gained here may further guide the rational design of multifunctional MOF composites tailored for advanced electrochemical applications. Acknowledgement This work was funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under project No. 09I02-03-V01-00022 (SUNFLOWERS) and No. 09I03-03-V03-00034 (MASS-PRAM). Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 53 SESSION 4 INORGANIC CHEMISTRY Half-sandwich type coordination compounds of ruthenium and osmium with 8-hydroxyquinoline derivates F. Czetnerovaa*, M. Matikova Malarovaa aDepartment of Inorganic Chemistry, Institute of Chemistry, P. J. Šafárik University in Košice, Moyzesova 11, 041 54 Košice, Slovakia. E-mail: [email protected] *frederika.[email protected]pjs.sk P-cymene is a naturally occuring compound as the major component of essential oils of plants of species Protium heptaphyllum and a biological precursor of carvacrol. It´s included in the group of monoterpens with known antioxidant effect. Coordinating chemical compounds including p-cymene with a ruthenium center represent a new group of compounds with possible antitumor activity. The reason behind this statement lies in the discovery of the complex [(η6-p-cymene)Ru(pta)Cl2] (pta - 1,3,5-triaza-7-fosfaadaamantane) also known as RAPTA-C, which exhibits lower toxicity and a different action mechanism as traditional platinum based anticancer drugs. Based on the structural type of this compound, many other compounds with various types of ligands have been prepared and studied with similarly promising properties.[1] Synthesis of these half-sandwich type compounds starts from the [Ru(η6-p-cymene)(μ-Cl)Cl]2 dimer shown in Figure 1 a.), which can be obtained in different halogenated forms such as bromine an iodine but also with different central atoms such as osmium. Based on the result of our research in the CSD database we found that we would like to prepare new compounds including 8-hydroxyquinoline derivates. The derivates include 5-chloro-7-bromo-8-hydroxyquinoline; 5,7-dijodo-8-hydroxyxyquinoline; 5chloro-7-nitro-8-hydroxyxyquinoline and 5-nitro-7-bromo-8-hydroxyxyquinoline. From the ruthenium and osmium dimers we prepared six compounds shown in Figure 1 b.) by adding the corresponding ligands to dichlormethane in the Monowave 300 microwave reactor. [2] The structure of [Ru(5-Cl,7-NO2Q)(cym)Cl], [Ru(5-Cl,7-BrQ)(cym)Cl], [Ru(5-NO2,7-BrQ)(cym)Cl], [Os(5-Cl,7-NO2Q)(cym)Cl], [Os(5-Cl,7-BrQ)(cym)Cl] and [Os(5-NO2,7-BrQ)(cym)Cl] has been confirmed using infrared spectroscopy, CHN elementar analysis, mass spectrometry and 1H NMR spectroscopy. [3] Acknowledgements This work was supported by the Slovak grant agencies (VEGA 1/0126/23) and the Erasmus program. References [1] Rausch M., Dyson P. J., Nowak‐Sliwinska P. RAPTA-C in cancer treatment and immunotherapy combinations. Adv. Ther. 2019;2(9):1900042. [2] PUJANTE-GALIÁN, María Angeles, et al. p-Cymene complexes of ruthenium (II) as antitumor agents. Molecules, 2020, 25.21: 5063. [3] Czetnerová, F. Diploma thesis, UPJŠ Košice, 2025. a.) b.) Figure 1 Structures of the a.) dimers and b.) compounds. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 54 SESSION 4 INORGANIC CHEMISTRY Use of silver compounds with potential biological activity in local therapy using creams and gels K. Harbulakovaa*, S. Sovovab, Z. Vargovaa a Department of Inorganic Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 041 54 Košice, Slovakia b Dean’s Office, Pavol Jozef Šafárik University in Košice, Šrobárova 2, 041 54 Košice *[email protected] Silver compounds represent a promising alternative for the treatment of infections caused by pathogenic microorganisms in view of the growing problem of bacterial resistance. The toxicity of silver toward bacterial cells has long been recognized, whereas its toxicity to humans appears to be relatively low, which is one of the main advantages of silver compared to other medically relevant metals [1]. Moreover, in recent decades, silver complexes have attracted considerable attention as potential anticancer agents, since complexes containing various types of ligands have demonstrated selective activity against different cancer cell lines [2]. The most common pharmaceutical dosage forms designed for topical application to the skin or mucous membranes are semisolid formulations, such as gels and creams. Their advantages include self-administration, non-invasiveness, and a reduced incidence of adverse reactions compared to other dosage forms. At the same time, they provide a suitable environment for the penetration of active substances into the skin [3]. In our experimental work, we prepare stable complexes of selected ligands with silver ions, which are expected to exhibit structural and other physicochemical properties suitable for the evaluation of biological activity, particularly antibacterial and anticancer effects. For characterization of prepared complexes infrared spectroscopy and X-ray analysis are used. These complexes are subsequently incorporated into semisolid pharmaceutical formulations, such as creams and gels, intended for topical application to the skin, with the aim of utilizing their biological activity directly at the site of action. The evaluation of these prepared creams and gels includes organoleptic assessment (colour, odor) and phase separation. Spreadability testing and pH measurement are evaluated at three different time intervals to assess their stability: on the day of preparation, after two weeks, and after one month. As a next step in our research, we will focus on evaluating the biological activity of prepared creams and gels, with emphasis on their potential antibacterial and anticancer effects for local therapeutic applications. Acknowledgements This work was financially supported by Slovak grant agencies VEGA 1/0268/24, KEGA 007UPJŠ-4/2024 and VVGS vvgs-2025-3528. References Medici, S. et al.: Coord. Chem. Rev, 327328, 349-359 (2016) Rendošová, M. et al.: J. Inorg. Biochem. 168, 1-12 (2017) Adeleye, O. A. et al.: J. Nanotechnol, 2023, 15 (2023) Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 55 SESSION 4 INORGANIC CHEMISTRY Enhancing CO₂ and H₂ Adsorption in MIL-101(Cr) via Polyethyleneimine Functionalization N. Hlavkovaa*, T. Zelenkab, M. Almasia aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bDepartment of Chemistry, Faculty of Science, University of Ostrava, 30. Dubna 22, 702 00 Ostrava, Czech Republic *nina.hlav[email protected]pjs.sk Various porous materials are studied nowadays across many fields of research to offer a solution to the modern world problems such as energy storage, fossil fuels replacement, the greenhouse gas effect and many more. Among them, one of the most extensive groups includes metal-organic frameworks (MOFs). MOFs can deal with all the mentioned above and other issues due to their special structure, which generally includes metal ions or clusters linked with an organic segment creating pores. Once synthesized, MOFs can undergo modification to improve their sorption capacity or other features. One of the possibilities, dealing with gas adsorption, is finding a substance capable of adsorbing gas well and covering a pore surface of the MOF with the substance e.g. with a polyethyleneimine (PEI). This polymer shows very good ability for CO2 capture even at low pressures or ambient temperature[1]. PEI also enhance pore structure and increases surface polarity, which is useful for H2 adsorption. In our work, we focused on one specific type of MOF - the MIL (Materials Institute Lavoisier) group and its postmodification to improve sorption capacities for H2 and CO2. We synthesized seven different MIL-101 materials with a structure of a 3D lattice and chose one of them for further study according to their sorption capacities. The one with the best overall results was MIL-101 containing chromium(III) ions in its metal clusters, and we modified it by PEI with three different monomeric units – 800, 1300 and 2000. The original material was modified by all three PEI polymers in four weight percentages 25%, 50%, 75% and 100% of PEI using methanol as a solvent. All the materials prepared, and the original MIL-101(Cr) were characterised by IR spectroscopy, powder X-ray diffraction, volumetric N2 adsorption @77 K, H2 adsorption @77 K and CO2 adsorption @273 K (see Figure 1). The results show that among the twelve modified samples, those containing 25 wt% PEI showed the best overall performance. In particular, the material modified by PEI 1300 at 25 wt% exhibited the highest surface area (SBET = 1567 m2/g). As can be seen in Figures 1d), e) and f), all 25 wt% samples demonstrate higher CO2 sorption capacities than the unmodified material (see blue (d), orange (e) and light green (f) curve in Figure 1) and for 50 wt% the capacities are similar to the original material. Figures 1a), b) and c) show that modified materials with 25 wt% exhibited similar (PEI 1300) or worse (PEI 800 and 2000) H2 sorption capacities. Other samples with MIL101(Cr) modified by PEI with higher wt% exhibited sorption capacities worse than the original material in both cases. Acknowledgements This work was supported by the projects APVV SK-CZ-RD-21-0068, LUASK22049 (INTER-EXCELLENCE II, MŠMT), VEGA 1/0058/25, and VEGA 1/0442/25. Refrences [1] Shen, X.; Du, H.; Mullins, R. H.; Kommalapati, R. R., Energy Technol 5 (2017) 822 – 833 Figure 1 a) b) c) H2 and d) e) f) CO2 adsorption isotherms of prepared MIL-101(Cr) PEI modified materials. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 56 SESSION 4 INORGANIC CHEMISTRY UiO-66-NH2 as an adsorbent of anionic xenobiotics from aqueous environments L. M. Holeczyovaa*, L. Zauskaa, M. Almasia aDepartment of Inorganic Chemistry, Institute of Chemical Sciences, Faculty of Science, Pavol Jozef Safarik University, Moyzesova 11, 040 01 Kosice *lara.mia.holeczyov[email protected] In recent years, there has been growing interest in developing metal-organic frameworks (MOFs) for environmental applications. These porous structures represent a promising approach in battling pollution of aqueous matrices [1]. MOFs, also known for high porosity and large surface area, are networks that can be modified for specific applications. Our work focuses on applying zirconium-based MOF, UiO-66-NH2, for heavy metal adsorption in water systems. The UiO-66-NH2 was synthesized via the solvothermal method and applied for metal ions adsorption from aqueous environment under varying conditions, e.g. mass concentration (50, 200 and 500 mg L-1), pH (7, 5, 3) and UV irradiation (254 and 366 nm). The studied metals (manganese and chromium) in their anionic forms (MnO4-, CrO42and Cr2O72-) were selected due to their distinct colour in solution, which can be detected by UV/VIS spectroscopy. Applied methods of characterization were infrared spectroscopy, powder X-ray diffraction and ultraviolet and visible light spectrophotometry. The infrared spectroscopy measured using the ATR technique, revealed characteristic bands of a primary amine at 3473 (νas(NH)) and 3376 (νs(NH)) cm-1, the carboxylate was displayed at 1565 (νas(COO-)) and 1381 (νs(COO- )) cm-1, in comparison with the starting material of 2-aminoterephthalic acid new signal was observed at 654 (ν(ZrO)) cm-1 which corresponds to the zirconium oxygen bond. Observed absorption bands are consistent with the literature describing UiO-66-NH2 structure. The measured PXRD pattern aligned with the previously described record [2] with peaks at 7.40°, 8.55° and 25.70°, which correspond to (111), (200) and (600) crystal planes, respectively. The characterization was complete through the techniques mentioned above. UiO-66-NH2 has semiconductive properties due to its favourable band gap energy. The energy was determined from UV/VIS spectra by Tauc plot analysis. Both direct and indirect transitions were calculated with values being 2.82 eV and 2.52 eV, respectively. Arising from this fact, photocatalytic degradation of MnO4was investigated. Adsorption capacity increased under 254 nm UV irradiation compared to no UV irradiation (see Table 1). The pseudo-first and pseudo-second order models were applied to the obtained data with the aim of a better understanding of the adsorption kinetics. Determined values of the maximum adsorption capacity, i.e. capacity in equilibrium and corresponding rate constants, are shown in Table 1. Table 1 Kinetic models. After successful synthesis, characterization, and adsorption studies of anionic heavy metals MnO4-, CrO42and Cr2O72-, findings indicated that in acidic conditions, the adsorption was more efficient compared to neutral pH conditions. There was an evident correlation between decreasing pH and increasing adsorption capacity. Similarly, UV irradiation had an influence on the amount of adsorbate (MnO4-) left in solution. Decreasing the UV wavelength led to a reduction in the amount of anionic metal left in the aqueous phase. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 57 Acknowledgements This work was supported by the projects APVV SK-CZ-RD-21–0068, LUASK22049 (INTER-EXCELLENCE II, MŠMT), VEGA 1/0058/25. References [1] Wen, Y.; Zhang, P.; Sharma, V. K.; Ma, X.; Zhou, H.-C. Cell Rep. Phys. Sci. 2021, 2, 100348. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 64 SESSION 4 INORGANIC CHEMISTRY Copper(II) Complexes Based on 1,2,4-Triazoles: Design and Characterization K.Michelovaa*, J.Kuchara aPavol Jozef Šafárik University in Košice, Faculty of Science, Department of Inorganic Chemistry, Moyzesova 11, 041 54 Košice, Slovakia *[email protected] Schiff bases, characterized by the presence of an imine group, are attractive due to their simple preparation and remarkable ability to coordinate with various transition metal ions, exhibiting outstanding chelating properties. In terms of stability, aromatic Schiff bases are more stable than their aliphatic counterparts and exhibit a wide range of biological and industrial applications, including anticancer, antioxidant, antibacterial, antiviral, and anticorrosion activities [1]. Their versatile chemical properties make them important ligands in coordination chemistry and material science [2]. Complex formation involves the binding of a d-block metal ion to electron-donating atoms within the ligand, which changes the metal’s steric and electronic environment. This interaction enhances the stability of the metal ion and helps control its reactivity, especially for ions that are less stable in higher oxidation states. Common donor atoms in such coordination include nitrogen, oxygen, or sulfur [3]. 1,2,4-Triazole and its derivatives are versatile multinitrogen donor ligands that coordinate first-row transition metals in mononuclear or polymeric complexes [4]. Newly synthesized Schiff base ligands, formed via the condensation of 4-amino-3,5-di-2-pyridyl-4H-1,2,4-triazole (abpt) and methoxy derivatives of salicylaldehyde, specifically 2-hydroxy-3-methoxybenzaldehyde (L1), 2-hydroxy-4-methoxybenzaldehyde (L2), and 2-hydroxy-5-methoxybenzaldehyde (L3), were subsequently used for the synthesis of complexes with a central Cu(II) atom. The prepared complexes [Cu(L1)2](NO3)·H2O (1) (Figure 1), [Cu(L2)2]·2MeOH (2) and [Cu(L3)2] (3), were characterized by IR spectroscopy, elemental analysis, and mass spectrometry. In all cases, the products were crystalline, which made it possible to study their structures by X-ray structural analysis. All complexes were studied in terms of their stability using UV-Vis spectroscopy. Such types of ligands also represent potential candidates for use as metalloligands in the preparation of complexes containing not only 3d but also 4f metals, which opens up further possibilities for their application. Figure 1 Crystal structure of (1). Acknowledgement This research is funded by the Cultural and Educational Grant Agency MŠVVaM, project No. 013UPJŠ-4/2024. References [1] K. Mezgebe, E. Mulugeta, Med Chem Res 33 (2024), 439–463. [2] H.G. Sogukomerogullari, A.O. Sarıoğlu, R.A. Kepekçi, B. Türkmenoğlu, M.H. Morcali, Inorganica Chimica Acta, 583 (2025), 1–15. [3] P. Martín-Ramos, J. López Martínez, et al. Journal of Inorganic Biochemistry. 158 (2016), 111–120. [4] E. Raczuk, B. Dmochowska, J. Samaszko-Fiertek, J. Madaj, Molecules. 27 (2022), 787. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 65 SESSION 4 INORGANIC CHEMISTRY Design, synthesis, characterision and photovoltaic application of CdTBDTA P. Obsatnika*, J. Shepab, M. Zelinskaa, M. Almasia, V. Zelenaka, N. Kiralya a Department of Inorganic Chemistry, Institute of Chemistry, Faculty of Science UPJS, Moyzesova 11, 041 54 Kosice, Slovak Republic b Department of Physical Chemistry, Institute of Chemistry, Faculty of Science UPJS, Moyzesova 11, 041 54 Kosice, Slovak Republic c Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01, Kosice, Slovak Republic *peter.ob[email protected]pjs.sk Metal–organic frameworks (MOFs) have emerged as versatile crystalline materials with tunable pore architectures, high surface areas, and a broad spectrum of functional properties, making them attractive for applications ranging from gas storage and separation to catalysis and optoelectronics. Within this family, azo-containing ligands hold particular interest due to their ability to undergo reversible trans–cis photoisomerization, enabling dynamic modulation of the framework’s geometry and electronic structure in response to external light stimul. Moreover, multidentate azo-ligands can promote the formation of extended coordination networks with enhanced stability and distinct optoelectronic features. Such characteristics position azo-based MOFs as promising candidates for next-generation photovoltaic materials, where controlled light–matter interactions can be directly translated into improved energy conversion performance [1]. Herein, we report the hydrothermal synthesis of a novel cadmiumbased MOF, CdTBDTA, along with its structural characterization, stability evaluation, and investigation of photovoltaic properties, highlighting its potential for solar energy applications. The newly obtained porous coordination polymer {[Cd3(TBDTA)2]∙6DMF∙H2O}n (CdTBDTA), incorporating the tritopic carboxylate linker H3TBDTA, was synthesized via a solvothermal reaction by dissolving 20 mg (0.029 mmol) of H3TBDTA and 8.95 mg (0.029 mmol) of Cd(NO3)2·4H2O in 8 mL of N,N´-dimethylformamide (DMF). To this solution, 0.5 mL of distilled water was added, and the mixture was sonicated for 5 minutes to ensure complete dissolution of the reactants. The resulting homogeneous solution was sealed in a glass vial and heated at 80 °C for 4 days. After cooling to ambient temperature, the orange crystalline product was isolated by filtration, washed several times with DMF and acetone, and dried in an air stream. The yield of CdTBDTA was 86 % based on the initial molar amounts of the reactants. The obtained material was characterized by IR spectroscopy, thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD) measurements. PXRD analysis showed that CdTBDTA is highly crystalline in its fresh state (CdTBDTA-AS), but exposure to moisture causes gradual lattice degradation. Despite this sensitivity, the material demonstrates full structural regeneration upon re-exposure to the mother liquor, effectively restoring its original framework properties. Acknowledgements This work was supported by VEGA 1/0058/25, 1/0442/25 and Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00008 (VVGS-2023-2923). References [1] S.A.A. Razavi, A. Morsali, Coord. Chem. Rev. 399 (2019) 213023. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 66 SESSION 4 INORGANIC CHEMISTRY Series of lanthanide-based MOFs as efficient sorbents for carbon dioxide capture P. Obsatnika*, V. Zelenaka, L. Zelenaa,b, T. Zelenkab, M. Almasia, N. Kiralya aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science UPJS, Moyzesova 11, 041 54 Kosice, Slovak Republic bDepartment of Chemistry, Faculty of Science, University of Ostrava, 30. dubna 22, Ostrava, CZ-702 00 Czech Republic *peter.ob[email protected]pjs.sk Greenhouse gases represent one of the main causes of global climate change, with carbon dioxide being one of the most prevalent components. The development of efficient technologies for capturing and removing CO2 from the atmosphere and industrial emissions is therefore essential to mitigate environmental damage. Metal-organic frameworks (MOFs), owing to their exceptional porosity, tunable modular structures, and versatile chemical functionalities, have emerged as promising materials for selective sorption of greenhouse gases. Particularly significant are MOFs that incorporate polydentate carboxylate ligands in their structure, forming stable and permeable networks with suitable active sites for gas capture [1]. Among these are lanthanide-based MOFs synthesized using azo-carboxylate tetratopic ligands such as H4MTA, which, due to their unique properties and structures, find broad application in the sorption of gases like carbon dioxide. In this study, we present the synthesis and detailed characterization of fourteen lanthanide-based metal-organic frameworks (LnMOFs) developed as efficient sorbents for carbon dioxide capture. The novel coordination polymers were prepared via solvothermal reaction between the tetratopic organic linker H4MTA [2] (0.09 mmol) and lanthanide nitrates Ln(NO3)3·xH2O (0.045 mmol) in a mixed solvent system of N,N´-dimethylformamide and water (6:1 ratio) at 80 °C over seven days. This synthetic strategy yielded a complete series of stable{[Ln4(MTA)3]·7H2O·9DMF}n LnMTA (Ln3+ = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) frameworks encompassing all stable lanthanide elements. The sorption properties of LnMTA complexes were studied using CO2 adsorption experiments. From the measured values, it follows that all lanthanoid MOFs exhibit a pronounced affinity for CO2 adsorption at a pressure of 1 bar, with the highest capacity at 0 °C achieved by TbMTA (3.7 mmol/g), followed by TmMTA (3.2 mmol/g) and EuMTA (3.1 mmol/g). At an elevated temperature of 20 °C, the adsorption values decreased as expected; however, materials such as GdMTA and TmMTA still demonstrated relatively high capacity (2.3 mmol/g). The adsorption properties of PrMTA and GdMTA were further investigated at high pressures and temperatures of 0 °C, 10 °C, and 25 °C (see Figure 1). These results confirm the high potential of LnMTA for efficient CO2 capture. . Figure 1 a) GdMTA - adsorbed valume of CO2, b) PrMTA - adsorbed valume of CO2. Acknowledgements This work was supported by VEGA 1/0058/25, 1/0442/25 and Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00008 (VVGS-2023-2923). Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 67 References [1] S. Su, W. Chen, Ch. Qin, S. Song, Z. Guo, et al. Cryst. Growth Des. 12 (2012) 1808 [2] M. Almáši, N. Király, V. Zeleňák, M. Vilková, S. Bourrelly, RSC Adv. 11 (2021) 20137 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 68 SESSION 4 INORGANIC CHEMISTRY New Azo-Based Multitopic Ligands for MOFs Construction P. Obsatnika*, M. Zelinskaa, M. Almasia, V. Zelenaka, N. Kiralya aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science UPJS, Moyzesova 11, 041 54 Kosice, Slovak Republic *peter.ob[email protected]pjs.sk Metal–organic frameworks (MOFs) are among the most promising modern materials due to their high porosity, structural versatility, and broad application potential. Particular attention is given to systems based on multitopic azo-organic ligands, whose reversible photoand thermo-induced isomerization enables modulation of the properties of the resulting structures. These ligands facilitate the formation of complex networks with unique functional characteristics and offer potential for the development of intelligent materials with adaptive behavior. The synthesis of such ligands represents a key step toward new generations of MOFs with expanded application scope [1]. In this work, we focused for synthesis of four new organic ligands (H4TAPPDA, H3APTD, H3MTATB-OH and H4ETAN) incorporating an azo linkage within their structure. All ligands were obtained through azo coupling via Mills condensation between the corresponding amine and ethyl 4-nitrobenzoate. The reactions were carried out under laboratory conditions in an inert dinitrogen atmosphere, employing methanol, acetic acid, or dichloromethane as solvents. The resulting ligands were successfully isolated and fully characterized by NMR and IR spectroscopy. These organic acids are currently being explored as building blocks for the design of novel MOF materials, with further results of this ongoing research to be presented. Figure 1 New Azo-Based Multitopic Ligands for MOF synthesis. Acknowledgements This work was supported by VEGA 1/0058/25, 1/0442/25 and Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00008 (VVGS-2023-2923). References [1] H. Ghasempour, K. Wang, J.A. Powel, F. ZareKarizi, X. Lv, A. Morsali, H. Zhou, Coord. Chem. Rev. 426 (2020) 213542. H4TAPPDA H3APTD H3MTATB-OH H4ETAN Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 69 SESSION 4 INORGANIC CHEMISTRY Silver(I) complexes with basic amino acids – their solution behaviour, solid state study and biological activity D. Snopekovaa*, G. Kuzderovaa, Z. Vargovaa, R. Gyepesb, M. Vilkovac a Department of Inorganic Chemistry, Faculty of Science, P.J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic b Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 00 Prague, Czech Republic c NMR laboratory, Faculty of Science, P.J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic *dominika.snopekov[email protected] Until the discovery and invention of antibiotics, silver was one of the few medicines capable of treating infections, burns, wounds, as well as preventing contagious diseases. The introduction of antibiotics in the 20th century drastically reduced the use of silver in medicine, however nowadays, with the increasing resistance of bacteria to antibiotics, it is necessary to use other effective antimicrobial agents for treatment. Currently, there are many ways to treat infectious diseases and one of the advancing solutions is the production of silver-based materials, such as complexes. It has been confirmed that the selection of a suitable ligand is very important in silver(I) complexes. A properly selected ligand can ensure more stable structures and more effective biological properties of compounds. The amino acids, we used, have a high affinity for silver(I), occur naturally in the human body and are non-toxic [1]. Furthermore, silver(I) complexes of amino acids have attracted considerable interest because of their wide-ranging antimicrobial properties and a variety of binding modes [2]. In the present study we focused on the formation of silver(I) complex species in solution by potentiometric titrations in order to design the synthesis conditions. Our work was also focused on the synthesis of silver(I) complexes with basic amino acids L-lysine (Lys) and L-Arginine (Arg) and its derivatives. Prepared complexes were characterized by various physico-chemical methods, e.g. elemental analysis, infrared spectroscopy, structural analysis, thermal analysis and 1H NMR spectroscopy. The crystal structure of complex [Ag(H2Lys)(NO3)]NO3 (AgLys) is depicted in Figure 1. Moreover, the antimicrobial and anticancer activity of several complexes were also evaluated. Figure 1 Crystal structure of complex [Ag(H2Lys)(NO3)]NO3 (AgLys). Acknowledgements This work was financially supported by Slovak grant agencies VEGA 1/0268/24 and KEGA 007UPJŠ-4/2024. References [1] G. Y. Xu, et al., Int. Dent. J., 74 (2024), 179-186. [2] S. Ahmad, et al., J. Struct. Chem., 56 (2015), 1653-1657. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 70 SESSION 4 INORGANIC CHEMISTRY Influence of Pore Hierarchy on the Catalytic Efficiency of Metal–Organic Frameworks HKUST-1 in Knoevenagel Condensation N. Vargovaa*, N. Kiralya, M. Zelinskaa, R. Serbinb, P. Obsatnika, L. Zelenac, M. Almasia aDepartment of Inorganic Chemistry, Faculty of Science, University of Pavol Jozef Safarik in Kosice, Moyzesova 11, 041 54 Kosice, Slovak Republic bDepartment of Analytical Chemistry, Faculty of Science, University of Pavol Jozef Safarik in Kosice, Moyzesova 11, 041 54 Kosice, Slovak Republic cDepartment of Chemistry, Faculty of Science, University of Ostrava, 30. dubna 22, 071 03, Ostrava, Czech Republic *[email protected] Metal–organic frameworks (MOFs) are hybrid crystalline materials composed of metal ions or metal clusters interconnected by organic linkers. Their exceptionally high specific surface areas, structural versatility, and tunable pore dimensions have made them prominent candidates for applications in heterogeneous catalysis [1]. In this study, two hierarchical porous materials, HKUST-1(A) and HKUST-1(B), were synthesized via a solvothermal approach employing different surfactant concentrations. Infrared spectroscopy confirmed the successful formation and activation of the frameworks as well as the efficient removal of the surfactant species. Nitrogen and argon adsorption/desorption analyses provided detailed insight into the porosity and textural properties of the materials. The templated synthesis route resulted in a significant enlargement of the pore dimensions compared to the parent HKUST-1, with pore diameters increasing from 0.9 nm to 8.5 nm. The isotherm profiles revealed that both HKUST-1(A) and HKUST-1(B) possess a combination of microand mesopores, with BET surface areas of 1687 m2·g-1 and 1554 m2·g-1, respectively. The catalytic performance of the synthesized frameworks was evaluated using the Knoevenagel condensation of benzaldehyde with malononitrile as a model reaction. Systematic optimization of reaction parameters, including solvent, temperature, and catalyst loading, demonstrated that both materials exhibit pronounced catalytic activity. Furthermore, the influence of electron-withdrawing (Figure 1) and alkyl substituents in various positions relative to the carbonyl group was investigated, providing deeper insight into substrate–catalyst interactions. Notably, HKUST-1(B) consistently exhibited superior catalytic performance compared to HKUST-1(A), which can be attributed to its higher mesopore content, facilitating more efficient transport of reactants and products as well as improved accessibility of the active sites. Figure 1 Comparison of conversion for reaction of benzaldehyde, a) orthoand b) para-substitueted benzaldehydes with malononitrile using HKUST-1(A) (AC) and HKUST-1(B) (AC) as catalysts. Acknowledgement This research was created with the support of grants VEGA 1/0058/25 and EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under project No. 09I03-03-V05-00008 (VVGS-ESGV-2923). References [1] Yang, D.; Gates, B. C. ACS Catal. 2019, 9, 1779-1798 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 71 SESSION 4 INORGANIC CHEMISTRY Heterogeneous Catalysis of the A³-Coupling Reaction over HKUST-1: A Green Synthetic Approach to Propargylamines N. Vargovaa*, M. Zelinskaa, R. Serbinb, M. Almasia, N. Kiralya aDepartment of Inorganic Chemistry, Faculty of Science, University of Pavol Jozef Safarik in Kosice, Moyzesova 11, 041 54 Kosice, Slovak Republic bDepartment of Analytical Chemistry, Faculty of Science, University of Pavol Jozef Safarik in Kosice, Moyzesova 11, 041 54 Kosice, Slovak Republic *[email protected] The A3-coupling reaction represents a three-component condensation of an aldehyde, an amine, and a terminal alkyne to afford propargylamines (Figure 1). One of the major advantages of this transformation lies in its excellent atom economy, as all atoms of the substrates are incorporated into the final product except for a single water molecule released during imine formation. This characteristic minimizes the formation of by-products, making the reaction an environmentally friendly synthetic approach that is well aligned with the principles of green chemistry. Moreover, A3-coupling reactions can often be performed under solvent-free conditions, at moderate temperatures (frequently even at ambient temperature), and in the presence of recyclable heterogeneous catalysts. Such reaction conditions not only reduce environmental impact but also facilitate product separation and catalyst recovery. Among the most promising catalytic systems for this transformation are metal–organic frameworks (MOFs) [1]. Metal–organic frameworks (MOFs) are crystalline materials composed of metal ions or clusters coordinated to organic ligands, forming porous three-dimensional networks characterized by high surface areas, tunable pore dimensions, and remarkable structural stability. Owing to their exceptional versatility, MOFs have found wideranging applications in gas storage and separation, catalysis, drug delivery, and sensing. Their unique structural features have attracted significant attention in the field of heterogeneous catalysis, primarily due to their highly customizable architectures, large surface areas, and well-defined pore networks [2]. This study focused on the A3-coupling reaction catalyzed by the porous metal–organic framework HKUST-1. The reaction involved the coupling of paraformaldehyde, phenylacetylene, and either diethylamine or piperidine. In a typical experiment, 10 cm3 of toluene, an internal standard (200 μl), paraformaldehyde (1.8 mmol), phenylacetylene (1.8 mmol), amine (1.8 mmol), and 50 mg of the catalyst were introduced into a reaction flask and heated to 120 °C. Upon completion, the catalyst was separated by centrifugation, and the resulting products were analyzed by gas chromatography. Figure 1 General scheme of the A3-coupling reaction. Acknowledgement This research was created with the support of grants VEGA 1/0058/25 and EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under project No. 09I03-03-V05-00008 (VVGS-ESGV-2923). References [1] M. A. Ghasemzadeh, B. Mirhosseini-Eshkevari, M. Tavakoli, F. Zamani, Green Chem. 22 (2020) 7265-7300. [2] K. Van Beurden, S. de Koning, D. Molendijk, J. van Schijndel, Green Chem. Lett. Rev. 13 (2020) 349–364. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 72 SESSION 4 INORGANIC CHEMISTRY Kinetic Adsorption Pathways of Co(II) and Congo Red on Pristine and Schiff Base– Modified MIL-101(Fe)-NH₂ Frameworks L. Zauskaa*, P. Pillarovab, D. Volavkac, M. Almasia aDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic cDepartment of Solid State Physics, Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University in Košice, Park Angelinum 9, 040 01 Košice, Slovak Republic *lubos.zausk[email protected] The study [1] explores the adsorption kinetics and mechanisms of heavy metal ions (Co(II)) and azo dye (Congo red) using pristine and surface-modified MIL-101(Fe)-NH₂ metal–organic frameworks. The modification was achieved through Schiff base formation with 2-pyridinecarboxaldehyde, yielding MIL-101(Fe)-Pyr, designed to enhance the material’s adsorption properties via the introduction of pyridine functionalities and additional coordination sites. Comprehensive characterization by FTIR, TG/DTA, ss-NMR, XPS, PXRD, and N₂ adsorption– desorption analyses confirmed the successful functionalization, high surface area, and preservation of the MIL101(Fe) framework after modification. Kinetic investigations demonstrated that MIL-101(Fe)-Pyr exhibited superior adsorption capacity and faster uptake rates for Co(II) compared to unmodified MIL-101(Fe)-NH₂, achieving a maximum adsorption capacity of 5.67 mmol g⁻¹ for Co(II) and 0.608 mmol g⁻¹ for Congo red. The pseudo-second-order kinetic model best described the adsorption behavior for both pollutants, indicating a chemisorption-dominated process. Boyd’s diffusion analysis suggested that external diffusion significantly influences the rate-controlling step, particularly during the initial adsorption phase. Isothermal modeling using Langmuir and Freundlich equations confirmed monolayer adsorption predominance for Co(II) ions and heterogeneous multilayer adsorption for Congo red molecules. Thermodynamic evaluations revealed spontaneous and endothermic adsorption processes for both contaminants, with stronger and more stable coordination between Co(II) ions and pyridine nitrogen sites on MIL-101(Fe)-Pyr. The adsorption mechanism involves chelation and electrostatic interactions for Co(II) and a combination of electrostatic and π–π stacking interactions for Congo red, demonstrating the material’s multifunctional adsorptive nature. While MIL-101(Fe)-Pyr showed excellent initial adsorption performance, structural instability and partial amorphization after repeated adsorption–desorption cycles were observed, posing challenges for reusability. Nevertheless, the modified framework remains a promising candidate for single-use or short-cycle applications in wastewater treatment targeting heavy metal removal, while both pristine and modified MIL-101(Fe)-based materials perform effectively for dye adsorption. These findings highlight the potential of Schiff base-modified MIL-101(Fe)-NH₂ frameworks as adaptable adsorbents for environmental remediation. Future research will focus on enhancing the structural robustness and recyclability of these materials to facilitate their transition toward practical, large-scale water purification systems. Figure 1 Schematic representation of the adsorption mechanism of Co(II) ions and Congo red dye on pristine MIL-101(Fe)-NH₂ and Schiff base-modified MIL-101(Fe)-Pyr. Acknowledgements This work was supported by the project VEGA 1/0058/25 and SK-CZ-RD-21-0068. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 73 References [1] L. Zauska, P. Pillárová, D. Volavka, E. Kinnertová, J. Bednarcik, J. Brus, V. Hornebecq, M. Almasi. Microporous Mesoporous Mater. 386 (2025) 113493. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 80 SESSION 5 LABORATORY OF NMR SPECTROSCOPY Synthetic approach to novel cyanoacetohydrazone derivatives of atranorin J. Eleckoa*, M. Gogab a Laboratory of NMR Spectroscopy, Institute of Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovakia b Department of Plant Biology, Institute of Biology and Ecology, Faculty of Science, P. J. Šafárik University in Košice, 04154 Košice, Slovakia *[email protected] Lichens present pioneer organisms, which can live in extreme habitats. These symbiotic organisms can deal with very specific conditions of environment because they produce secondary metabolites, which provide them good protection against various negative physical and biological influences [1]. One of the most common lichen secondary metabolites is atranorin, which is characteristic of numerous lichen families. It belongs to the depsides group, consisting of two monocyclic aromatic units linked by ester bond. Atranorin exhibits number of biological activities including antioxidant, anti-inflammatory, analgesic, antiviral, antibacterial, antifungal, cytotoxic and immunomodulatory activities [2]. N-acylhydrazone pattern can be recognized in many bioactive molecules and stability of these compounds can be increased with aromatic substituents. A number of acylhydrazones show antimicrobial, antibacterial, haemostatic, anti-HIV, anti-inflammatory and cytotoxic activities [3,4]. We report synthetic approach to a novel aromatic cyanoacetohydrazones 3 derived from atranorin 1 (Figure 1). Using catalytic amount of acetic acid and ethanol as solvent, products of transesterification with ethanol 4 and 5 were isolated. However, aromatic cyanoacetohydrazones derived from compound 4 are also of interest. Atranorin used in these experiments was isolated from lichen Stereocaulon grande collected during a field trip in certain regions of Finland in September 2024. Figure 1 Synthetic approach to novel cyanoacetohydrazone derivatives of atranorin. Acknowledgements This work was supported by the KEGA 008UPJŠ-4/2023. References [1] M. Goga, et al, Lichen Metabolites: An Overview of Some Secondary Metabolites and Their Biological Potential; in: Co-Evolution of Secondary Metabolites : Reference Series in Phytochemistry. Springer Nature 2020, Basel, p. 175-209. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 81 [2] E. Studzinska-Sroka, A. Galanty, W. Bylka, Mini-Reviews in Medicinal Chemistry, 17 (2017) 1633-1645. [3] S. Thota, D. A. Rodrigues, P. De S. M. Pinheiro, L. M. Lima, C. A. M. Fraga, E. J. Barreiro, Bioorganic & Medicinal Chemistry Letters 28 (2018) 2797-2806. [4] H. Zhang, S. Min, L. Zhang, L. Li, Journal of Molecular Liquids 348 (2022) 118034. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 82 SESSION 5 LABORATORY OF NMR SPECTROSCOPY Electrosynthetic Hydrolysis of Dihyhydropyrimidinones T. J. Liskaa*, M. Parackovaa, R. Orinakovaa, M. Vilkovaa aInstitute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] A central goal of modern chemistry is the development of novel, cost-effective biologically active compounds that enhance therapeutic efficacy while reducing or ideally eliminating adverse side effects. Notably, statistical analyses indicate that over 85% of known bioactive molecules contain heterocyclic frameworks [1]. Among the most versatile synthetic strategies for accessing such structures are multicomponent reactions (MCRs) [2]. Using the Biginelli MCR, we synthesized a dihydropyrimidinone (DHPM), which was subsequently modified electrochemically (Figure 1A). In particular, we accomplished the electrochemical hydrolysis of an ester group that has been reported to exhibit exceptional resistance toward hydrolytic attack [3]. Consistent with this literature precedent, our control experiment demonstrated that compound 1 remains remarkably stable under harsh basic conditions (pH > 14, 100°C, 48 h), with only approximately 1% ester cleavage observed. To further understand this reactivity, the kinetics of the electrochemical hydrolysis of compound 1 (Figure 1A) were investigated by cyclic voltammetry across scan rates ranging from 25 to 150 mV·s⁻¹.This analysis was performed in a three-electrode setup with a Pt working electrode, Pt counter electrode, and an Ag/AgCl (3 M KCl) reference electrode. At each scan rate, the oxidation peak current (Ip) was extracted for further analysis. The slope of the logarithm of the maximum current response (Ip) versus the logarithm of the scan rate (ν) (Figure 1B, 0.566) close to 0.5 indicates that the studied process is controlled by diffusion [4]. Figure 1 A) Setup and scheme of the electrochemical hydrolysis and B) the log of peak current (Ip) versus the log of the scan rate (ν). Acknowledgements Part of the research results was obtained using the computational resources procured in the national project National competence centre for high performance computing (project code: 311070AKF2) funded by European Regional Development Fund, EU Structural Funds Informatization of society, Operational Program Integrated Infrastructure, and by the Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic: KEGA Grant No. 008UPJS-4/2023. References [1] I. Pibiri, Int J Mol Sci 25 (2024) 9503. [2] I. Ugi, A. Dömling, W. Hörl, Endeavour 18 (1994) 115–122. [3] D. Dallinger, C.O. Kappe, Pure and Applied Chemistry 77 (2005) 155–161. [4] A.M. Bagoji, S.M. Patil, S.T. Nandibewoor, Cogent Chem 2 (2016) 1172393. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 83 SESSION 6 ORGANIC CHEMISTRY Synthetic Approach to 6-Bromo Derivatives of Indole Phytoalexins and Their Anticancer Profile M. Budovskaa*, L. Ocenasovaa, P. Ocenasb, R. Michalkovac, J. Mojzisc aDepartment of Organic Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovakia bDepartment of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy in Košice, 041 81, Košice, Slovakia cDepartment of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University in Košice, SNP 1, 040 11 Košice, Slovakia *mariana.b[email protected] 1-Methoxybrassinin (1), 1-methoxyspirobrassinol methyl ether (2) and cyclobrassinin (3, Figure 1) belong to the class of indole phytoalexins produced by plants of the Brassicaceae family and are characterized by remarkable cytotoxic activity against various human cancer cell lines with IC50 values at the micromolar level [1]. A wide range of derivatives of these indole phytoalexins has been synthesized, and some structural modifications 4-7 (Figure 1) resulted in a significant increase in antiproliferative activity compared to parent molecule [2]. To expand the structure–activity relationship of this natural products class towards human cancer cells, we carried out another structural variation, and we have prepared a library of 6-bromoderivative of these indole indole phytoalexins (Figure 1). Novel 6-bromo-1-Boc-brassinin and its amino analogues 8 were synthesized from 6bromo-1H-indole-3-carboxaldehyde using a fouror five-step procedure. The bromospirocyclization of derivatives 8 in the presence of various nucleophiles (methanol or a suitable aniline) has been applied to the synthesis of spirocycles 9. Cascade reactions of the spirocyclic products 9 promoted by TFA led to the formation of 7bromocyclobrassinin and its 2-amino analogues 10. Several newly synthesized 6-bromoderivatives have shown potential as cancer treatments by inhibiting cancer cell growth [3]. Figure 1 Natural indole phytoalexins and their structural modifications. Acknowledgements This research was funded in part by the Grant Agency of Ministry of the Education, Science, Research and Sport of the Slovak Republic (VEGA 1/0347/23 a VEGA 1/0037/22). Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 84 References [1] M. S. C. Pedras, A. Abdoli, RSC Adv. 7 (2017), 23633. [2] M. Zigová, R. Michalková, J. Mojžiš, Molecules 29 (2024) 2388. [3] M. Budovská, L. Očenášová, P. Očenáš, R. Michalková, J. Mojžiš, Tetrahedron 171 (2025) 134432. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 85 SESSION 6 ORGANIC CHEMISTRY Total synthesis of (‒)-deoxoprosopinine and its analogues M. Fabiana*, J. Spakova Raschmanovaa*, M. Martinkovaa aInstitute of Chemical Sciences, Department of Organic Chemistry, P. J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic *martin.fab[email protected], *jana.raschman[email protected] Nature has afforded a wide variety of piperidine alkaloids as secondary metabolites, which have been identified primarily in terrestrial plants. A remarkable subclass within this group, also referred as “alkaloid lipids” (AL), has been isolated from the stems, leaves, and roots of Prosopis and Cassia species. These molecules are characterised by a variably substituted long alkyl chain at C-6 and a polar C-2 hydroxymethyl substituted 3-hydroxypiperidine unit (Figure 1). In addition to their distinctive architecture, both natural AL and their synthetic analogues exhibit a broader spectrum of biological activities, including cytotoxic, antifungal, antibiotic, anesthetic, and stimulant effects. These interesting pharmacological findings have stimulated a number synthetic efforts, and several strategies and aproaches have been reported. [1,2,3] Figure 1 Structures of selected alkaloid lipids 1−4. Figure 2 Retrosynthetic analysis of our target C-alkyl piperidines 1.HCl‒4.HCl. A straightforward route to a small library of the stereoisomeric alkaloid lipids 1.HCl–4.HCl starting from the advanced synthons 5 and 6, was deveoleped. The core scaffolds were constructed via olefination steps, followed by an Overman rearrangement to introduce the novel stereochemistry. Formation of the piperidine ring was achieved through an intramolecular nucleophilic substitution, while the hydrophobic alkyl branche was installed at a later stage in the synthesis using olefin cross-metathesis. The prepared final compounds 1.HCl–4.HCl are currently being evaluated for their in vitro antiproliferative activity on a panel of cancer cell lines. Acknowledgements The present work was supported by the Grant Agency (no. 1/0278/23) of the Ministry of Education, Slovak Republic. This work is also the result of the project implementation: Open scientific community for modern interdisciplinary research in medicine (OPENMED), ITMS2014+: 313011V455 supported by the Operational Programme Integrated Infrastructure, funded by the ERDF. References [1] S. T. Pruett, A. Bushnev, K. Hagedorn, M. Adiga, C. A. Haynes, M. C. Sullards, D. C. Liotta, A. H. Merrill, J. Lipid Res. 49 (2008) 1621−1639 and references cited therein. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 86 [2] R.-C. Liu, J.-H. Wei, B.-G. Wei, G.-Q. Lin Tetrahedron: Asymmetry 19 (2008) 2731−2734 and references cited therein. [3] S. D. Koulocheri, E. N. Pitsinos, S. A. Haroutounian, Curr. Org. Chem. 12 (2008) 1454−1467 and references cited therein. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 87 SESSION 6 ORGANIC CHEMISTRY Molecular docking study of novel pyrrolidine derivatives as multi-target modulators N. Georgioua,b*, M. Fabianc, T. Poncakovac,d, M. Zelinskac, M. Martinkovac, V. Huntosovab. aLaboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 11571 Athens, Greece bCenter for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Safarik University in Kosice, Jesenna 5, Kosice, Slovakia cInstitute of Chemical Sciences, Department of Organic Chemistry, P. J. Šafárik University, Moyzesova 11, 041 54 Košice, Slovakia dJuhapharm, Ltd., Myslavská 644/190/A, 040 16, Košice, Slovakia *[email protected] Nowadays, the research about the biological potential of long-chain pyrrolidine derivatives has been attracted the scientists. In this work, we investigated a series of newly synthesized pyrrolidines. Specifically, MF-101, MFHOV104, SR14, SS14, MA-201, TP3, TP5 and MA-20 were tested in silico using molecular docking and interaction energy analyses toward key protein targets involved in tumor growth, and lipid signaling: HER2 receptor [1], LDL receptor, sphingosine-1-phosphate phosphatase, LC3BI, cathepsin B, M6PR and protein kinase C (PKC) δ and α. All the docking calculations were conducted via Autodock software. Docking simulations revealed favorable binding energies for several derivatives. Among these, MFHOV104 and TP5 showed the strongest and most consistent binding affinities. MFHOV104 exhibited favorable interactions with HER2 (-6.51 kcal/mol) and PKC (-6.23 kcal/mol), while TP5 bound effectively to cathepsin B (-5.96 kcal/mol) PKCδ (–6.00 kcal/mol), and the LDL receptor (–5.68 kcal/mol). Overall, PKC isoforms, Cathepsin B, and HER2 emerged as key potential targets, whereas LC3B I displayed weak interactions across all compounds. These findings suggest that MFHOV104 and TP5 are the most promising candidates for further investigation. Initial in vitro studies should focus on confirming HER2 and PKCα inhibition by MFHOV104, and Cathepsin B and PKCδ inhibition by TP5, to validate their predicted biological activities. Overall, these computational findings support the hypothesis that the tested pyrrolidine derivatives could act as multi-target modulators influencing key pathways in cancer [2]. The results provide a valuable framework for further in vitro validation and optimization of these compounds as potential anticancer agents. Figure 1 (left) Docking pose of MFHOV104 in HER2 receptor and (right) structure of MFHOV104. Acknowledgements The work has been supported by the project “Consortium for Advanced Protein Biotechnology: A Model to Support Economic Growth and Migrate Brain Drain from Eastern Slovakia” (APBC) funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09-I02-03-V0100021 and the project BCOrgFluorIDA No. 09I03-03-V04-00007. References [1] T. Ishikawa, Design and Synthesis of Novel Human Epidermal Growth Factor Receptor 2 (HER2)/Epidermal Growth Factor Receptor (EGFR) Dual Inhibitors Bearing a Pyrrolo[3,2-d]Pyrimidine Scaffold.. J. Med. Chem. 2011, 54 (23), 8030–8050. [2] N. Georgiou, Thiocarbohydrazone and Chalcone-Derived 3, 4-Dihydropyrimidinethione as Lipid Peroxidation and Soybean Lipoxygenase Inhibitors., ACS omega, 8 (13), 11966–11977. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 88 SESSION 6 ORGANIC CHEMISTRY Bis-Indole Analogues Derived from Indole Phytoalexins: Synthesis and Antiproliferative Profile S. Chovanovaa, R. Michalkovab, V. Miskufovab, J. Mojzisb, M. Budovskaa* aDepartment of Organic Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovakia bDepartment of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University in Košice, SNP 1, 040 11 Košice, Slovakia *mariana.b[email protected] Indole phytoalexins include a group of secondary metabolites biosynthesized de novo by plants of the family Brassicaceae in response to biotic or abiotic stress. These phytoalexins exhibit antimicrobial, antiobesity, antiinflammatory, antidiabetic, antiatherosclerotic, and anticancer properties [1,2]. In this work, we prepared a small library of bis-indole compounds inspired by indole phytoalexins (Figure 1), which have the SCH3 group replaced by another indole ring. We designed and synthesized novel bis-indole thioureas I with various combinations of substituents on the N-1 and N´-1 indole nitrogens as brassinin analogues. The cyclization protocol of thioureas I using methyl bromoacetate provided bis-indole thiazolidin-4-one derivatives II. The formation of the spiro center at carbon C-3 in bis-indole derivatives of spirobrassinin III was ensured by oxidative spirocyclization of thioureas I using chromium trioxide. A two-step process involving bromospirocyclization of thiourea I with methanol and TFA-induced rearrangement led to the formation of the bis-indole analogue of cyclobrassinin IV. Some novel bis-indole compounds have shown significant potential in reducing the growth of human cancer cells (HCT-116, MCF7, and A2780) to a greater extent than cisplatin. Figure 1 Bis-indole analogues derived from indole phytoalexins. Acknowledgements This research was funded in part by the Grant Agency of Ministry of the Education, Science, Research and Sport of the Slovak Republic (VEGA 1/0347/23 a VEGA 1/0037/22). References [1] M. Zigová, R. Michalková, J. Mojžiš, Molecules 29 (2024) 2388. [2] M. S. C. Pedras, A. Abdoli, RSC Adv. 7 (2017), 23633. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 89 SESSION 6 ORGANIC CHEMISTRY Development of 2,9-disubstituted acridines as topoisomerase IIα inhibitors L. Janoveca*, A. Guckyb, K. Krochtovab, R. Michalkovac, K. Kusnirovaa, V. Miskufovac, D. Jagerd, J. Mojzisc, M. Kozurkovab aDepartment of Organic Chemistry, Institute of Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01, Košice, Slovak Republic bDepartment of Biochemistry, Institute of Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 040 01, Košice, Slovak Republic cDepartment of Pharmacology, Faculty of Medicine of P. J. Šafarik University in Kosice, Tr. SNP 1, 040 11 Košice, Slovak Republic dInstitute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 040 01, Kosice, Slovak Republic *ladislav.janov[email protected] A series of 2,9-disubstituted acridines (8a–8h) was synthetized and assessed for their biological activities [1]. The acridines featured various 9-anilino or 9-phenylalkyl substituents and were prepared via a linear sequence of six steps using commercially available starting materials. The relationship between the physico-chemical properties of the 2,9-disubstituted acridines and their biological activity was studied, and the DNA binding capacities of the synthetized acridines were determined using spectroscopic (Kb 0.5–10.4 × 104 M-1) and thermal denaturation (Tm 4.2–9.8°C) methods. The inhibitory potential of acridines 8a–8h toward human topoisomerase I/IIα was evaluated, and 9-phenylbutyl acridine 8h was found to inhibit human topoisomerase IIα at concentrations as low as 5 µM. Acridines 8a–8h were also subjected to in vitro screening against selected cancer cell lines; the most potent anticancer activity was observed against melanoma A2058 cell lines at IC50 values ranging from 3 to 6 M. CO2H Cl NHAc NH2 + N H NHAc HO2C N H O NH2 N H O N H O Cl N H O N H O N i ii iii iv v 123456 7 Reagents and reaction conditions. i: 2-ethoxyethanol, Cu(s), CuO, K2CO3, 130°C, 4h., 82%; ii: a.) 98% H2SO4, 100°C, 1h., b.) 50% H2SO4, 100°C, 1.5h., 60%; iii: 2-chloropropionyl chloride, 100°C, 1h., 68%; iv: pyrrolidine, KI, etanol, reflux, 3h., 86%, v: POCl3, N2(g), 100°C, 2h., 70%; vi: 4-R-Ph-(CH2)n-NH2, DMF, 110°C, 5h. 8a - 8h R= H n=0 8a R= N(CH3)2 n=0 8b R= F n=0 8c R= Br n=0 8d R= H n=1 8e R= H n=2 8f R= H n=3 8g R= H n=4 8h vi N Cl NH O N N NH NH O N [CH2]n R Figure 1 Sythesis of 2,9-disubstituted acridines 8a - 8h. Acknowledgements Financial support for this study was provided by VEGA Grant No. 1/0037/22, 1/0539/21, 2/0112/22, 1/0074/24 and project implementation: “Openscientific community for modern interdisciplinary research in medicine (OPENMED)”, ITMS2014+:313011V455, supported by the Operational Programme Integrated Infrastructure, funded by the ERDF, project implementation “Medicínsky univerzitný vedecký park v Košiciach (MediPark. Košice—Fáza II.)”, kód ITMS2014 + 313011D103 supported by the Operational Programme Research & Innovation. funded by the ERDF. References [1] L. Janovec, A. Gucký, K. Krochtová, R. Michalková, K. Kušnírová, V. Miškufová, D. Jáger, J. Mojžiš, M. Kožurková, ChemMedChem 20 (2025) e202500267. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 96 [5] K. Stanková, G. Ondrejkovičová, M. Martinková, M. Bago Pilátová, J. Kuchár, M. Litecká, Carbohydrate. Res. 553 (2025) 109512. [6] D. Fábianová, T. Pončáková, M. Martinková, M. Fábian, M. Fabišíková, M. Bago Pilátová, A Macejová, J. Kuchár, D. Jáger, Tetrahedron 96 (2021), article number 132380. [7] L. Maram, B. Das, Helv. Chim. Acta 98 (2015), 674-682. [8] R.J. Davoille, D.V. Rutherford, S.D.R. Christie, Tetrahedron Lett. 41 (2000), 1255-1259. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 97 SESSION 6 ORGANIC CHEMISTRY Stereoselective synthesis of jaspine B-based mimetics K. Stankovaa*, A. Minkoa, G. Ondrejkovicovaa, M. Martinkovaa aInstitute of Chemical Sciences, Department of Organic Chemistry, P. J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] Cancer is the second leading cause of death worldwide. Modulation of sphingolipid biosynthesis and metabolism is expected to be one of the promising approaches for therapy of the aforementioned disease.[1] Jaspines, represented by jaspine B (1) (Figure 1) [1] belong to the class of anhydrophytosphinosine-type compounds produced by marine organisms. The remarkable cytotoxicity of 1 was demonstrated on at least 30 human cancer cell lines, with IC50 values ranking at micromolar levels. [2] Due to the impressive biological properties and challenging structural motif based on the presence of substituted THF core, a great deal of effort has been expended for the construction of 1 and its various analogues (Figure 1). [2,3] Figure 1 Jaspine B and its several cytotoxic mimetics 2‒5. [2,3] The retrosynthetic approach to novel isomeric jaspine B mimetics 6 and 7 is depicted in the Figure 2. The prepared analogues have an interesting vicinal amino alcohol motif bearing a tetrasubstituted stereocentre, with the resulting arrangement of the amino and hydroxyl functionalities being in the opposite mode compared to the parent molecule 1. Moreover, the novel C-N bond was also installed in the side chain. We envision that the designed compounds 6 and 7 could be accessible from derivatives 8 and 9, respectively, via OCM reaction, followed by a deoxygenation protocol. The requisite trichloroacetamides might, in turn, arise from an allylic substrate derived from 10 using Overman reaction. The corresponding ester 10 was easily obtained from the known alcohol 11 [4] through [3,3]- sigmatropic rearrangement and HWE olefination. Figure 2 Retrosynthetic strategy toward mimetics 6 and 7. Acknowledgements The present work was funded by the Grant Agency (no. 1/0278/23) of the Ministry of Education, Slovak Republic. Financial support from the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09-I02-03-V01-00021 and Internal Grant System (no. vvgs-2025-3492) at the Faculty of Science of P. J. Šafárik University in Košice are also gratefully acknowledged. References [1] A. Delgado, G. Fabriás, J. Casas, J. L. Abad, Adv. Cancer Res. 117 (2013) 237-281 and references cited therein. [2] M. Martinková, J. Gonda, Carbohydr. Res. 423 (2016) 1-42 and reference cited therein. [3] M. Martinková, J. Gonda, Carbohydr. Res. 482 (2019) 1-26 and refereces cited therein. [4] M. Martinková, J. Gonda, J. Raschmanová, Molecules 11 (2006) 564-573. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 98 SESSION 6 ORGANIC CHEMISTRY DIX-like azasugars ‒ synthesis and antiproliferative profile J. Spakova Raschmanovaa*, M. Martinkovaa, A. Sudzinaa, G. Ondrejkovicovaa, M. Bago Pilatovab, J. Kucharc aInstitute of Chemical Sciences, Department of Organic Chemistry, P. J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Pharmacology, Faculty of Medicine, P. J. Šafárik University, SNP 1, 040 66 Košice, Slovak Republic cInstitute of Chemical Sciences, Department of Inorganic Chemistry, P. J. Šafárik University, Moyzesova 11, 040 01 Košice, Slovak Republic *[email protected] Iminosugars and related azasugars have attracted considerable attention over the past three decades owing to their broad spectrum of biological activities. [1] 1,5-Dideoxy-1,5-iminoxylitol 1 (DIX, Figure. 1) belongs to the group of the natural unmodified hydrophilic 1-N-iminosugars. [2] This compound was isolated from the plant Eupatorium fortunei Turz which is used in traditional Chinese medicine as well as in Japanese folk medicine for its diuretic, antipyretic and antidiabetic properties. DIX was one of the first candidates, which were identified as pharmacological chaperones (PCs) for the treatment of lysosomal storage disorders such as Gaucher disease. [3] In view of the impressive biological profile of 1, several interesting approaches leading to this natural 3,4,5trihydroxypiperidine as well as to its synthetic analogues, including Oand C-alkylated derivatives 2 and 3, respectively, and the C-branched compound 4 (Figure 1) have been elaborated. [2] Among DIX-based analogues illustrated in Figure 1, the 2-C-nonyl iminosugar 3 displayed a remarkable inhibitory capacity toward the human acid β-glucosidase with the IC50 value in a nanomolar range. [4] Figure 1 DIX 1 and its analogues 2−4. Recently, our group developed a simple stereodivergent route to DIX-like 1-N-iminosugars 5.HCl and 6.HCl from D-xylofuranose chiron 10 (Figure 2). The advanced scaffolds 7 and 8 were assembled by Wittig olefination, followed by the heterosigmatriopic rearrangement to establish the novel stereochemistry. Subsequent OCM reaction introduced a hydrophobic alkyl branch and finally, the 6-exo-tet type cyclisation led to a piperidine core. Crystallographic analysis of the oxazolidinone 9 confirmed the stereochemistry established by the rearrangement reaction. Cell viability experiments showed that the prepared C-alkyl piperidine-3,4,5-triols 5.HCl and 6.HCl have a capacity to inhibit the proliferation of cancer cell lines in vitro. Figure 2 Retrosynthetic analysis of our target DIX analogues 5.HCl and 6.HCl. Acknowledgements The present work was supported by the Grant Agency (No. 1/0278/23) of the Ministry of Education, Slovak Republic. This work was also funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09-I02-03-V01-00021. X-ray of compound 9 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 99 References [1] I. Conforti, A. Marra, Org. Biomol. Chem. 19 (2021) 5439‒5475 and references cited therein. [2] A. Wood, K.L. Prichard, Z. Clarke, T.A. Houston, G.W.J. Fleet, M.I. Simone, Eur. J. Org. Chem. 2018 (2018) 6812‒6829 and references cited therein. [3] J. Stirnemann, N. Belmatoug, F. Camou, C. Serratrice, R. Froissart, C. Caillaud, T. Levade, L. Astudillo, J. Serratrice, A. Brasseir, C. Rose, T.B. de Villemeur, M.G. Berger, Int. J. Mol. Sci. 18 (2017) 441. [4] P. Compain, O.R. Martin, C. Boucheron, G. Godin, L. Yu, K. Ikeda, N. Asano, ChemBioChem 7 (2006) 1356‒1359. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 100 SESSION 6 ORGANIC CHEMISTRY 2-C-Tridecyl piperidine-3,4,5-triols: Synthesis and Preliminary Biological Evaluation M. Tvrdonovaa*, P. Michalcina, T. Poncakovaa,b, Y. Zuzaka, M. Bago Pilatovac, J. Kuchard, M. Liteckae, M. Martinkovaa aDepartment of Organic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic b Juhapharm, Ltd., Myslavská 644/190/A, 040 16, Košice, Slovak Republic cInstitute of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University in Košice, SNP 1, 040 66 Košice, Slovak Republic dDepartment of Inorganic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic eInstitute of Inorganic Chemistry of the Czech Academy of Sciences, Husinec-Řež 1001, 25068 Řež, Czech Republic *monika.tv[email protected] Piperidine-type iminosugars have shown a rich variety of relevant pharmacological activities against glycosidase enzymes, and many of them have been highlighted as lead candidates for the treatment of various diseases, including cancer, diabetes, viral infections, and lysosomal storage disorders, e.g. Gaucher and Fabry disease. [1, 2] Iminosugars with Nand Olinked alkyl chains of varying lengths also exhibit a broad spectrum of biological properties, including antiviral, antibacterial, immunosuppressant, and anti-inflammatory activities. [3] Our main goal herein was the design of new azasugar mimetics and their cytotoxic screening. We used independent pathways for the synthesis of four stereoisomeric 2-C-tridecyl piperidine-3,4,5-triols 1.HCl‒2.HCl and ent-1.HCl‒ ent-2.HCl from two different chirons: L-arabinose and D-lyxose, respectively. (Figure 1) The key step in both synthetic strategies was the [3,3]-heterosigmatropic rearrangement to install nitrogen-bearing stereocentres. Incorporation of a C-2 alkyl chain via olefin cross-metathesis was performed in different stages of synthetic strategies, once before and a second time after the cyclization step. The antiproliferative activity of the final compounds was tested and revealed that all of them have promising cytotoxicity against leukemia cells. Furthermore, compounds 1.HCl and 2.HCl exhibited to be more potent against the HeLa cell line than their corresponding antipodes ent-1.HCl‒ent-2.HCl. Exploration of further alkylated piperidine analogues will expand the library of existing sugar mimetics and provide a more comprehensive view of their biological activity. Figure 1 Retrosynthetic strategy toward piperidine trioles 1.HCl, 2.HCl, ent-1.HCl, and ent-2.HCl. Acknowledgement This work was supported by the Grant Agency (no. 1/0278/23) of the Ministry of Education, Slovak Republic and by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project Nos. 09I0303-V04-00751 and 09I03-03-V05-00008. References [1] A. Wadood, M. Ghufran, A. Khan, S.S. Azam, M. Jelani, R. Uddin, Int. J. Biol. Macromol. 111 (2018) 82–91 and references cited therein. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 101 [2] E.M. Sánchez-Fernández, J.M.G. Fernández, C.O. Mellet, Chem. Commun. 52 (2016) 5497‒5515 and references cited therein. [3] K. Prichard, D. Campkin, N. O’Brien, A. Kato, G.W.J. Fleet, M.I. Simone, Chem. Biol. Drug Des. 92 (2018) 1171‒1197 and references cited therein. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 102 SESSION 6 ORGANIC CHEMISTRY Synthesis and biological profile of a novel C-branched pyrrolidine-based iminosugar M. Tvrdonovaa*, Y. Zuzaka, M. Bago Pilatovab, R. Mezencevc, M. Martinkovaa aDepartment of Organic Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University in Košice, SNP 1, 040 66 Košice, Slovak Republic cGeorgia Institute of Technology, College of Science, School of Biology, 310 Ferst Drive, Atlanta, GA 30332, USA *monika.tv[email protected] Polyhydroxylated pyrrolidines are a relatively large and extensively studied subclass of the iminosugar family, covering both naturally occurring and synthetic molecules. Most of them have been shown to be promising and selective inhibitors of glycosidases, the enzymes that cleave glycosidic bonds and participate in a wide range of key biological processes. [1] It is worth noting that many of these sugar mimetics share a skeleton based on 1,4dideoxy-1,4-imino-D-arabinitol 1 (DAB), or its enantiomeric counterpart ent-1 (LAB), as the parent molecules. [1] Since the isolation of DAB in 1985, a significant number of unnatural pyrrolidine-containing sugar mimetics have been prepared in order to find novel bioactive agents as potent but still selective glycosidase inhibitors. [2,3] Among them, C-branched analogues have shown their capacity to specifically block various glycosidases. [4] Based on the above-mentioned findings, we decided to develop the synthesis of a novel branched iminosugar decorated with the long alkyl chain. The retrosynthetic strategy for the target pyrrolidine-based iminosugar 2.HCl is illustrated in Figure 1. We envisioned that 2.HCl could arise via oxidative cleavage of the vicinal diol moiety in 3 followed by reductive work. It was anticipated that the bicyclic system in 3 would be accessible by an alkylative cyclisation from the aminofuranose 4. The 3-C-alkylated derivative 4 can be derived from the vinyl scaffold 5 [5] through a pivotal OCM reaction. Cell viability experiments revealed a cytotoxic effect of the target compound 2.HCl against Jurkat and HeLa cells (IC50 = 20.58 μM and 22.7 μM, respectively). In addition, docking studies [6] identified the binding modes of this novel pyrrolidine-based iminosugar to human β-glucocerebrosidase. docking studies [6] Figure 1 Retrosynthetic analysis of the branched iminosugar 2.HCl. Acknowledgements This work was supported by the Grant Agency (no. 1/0278/23) of the Ministry of Education, Slovak Republic. The EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09-I0203-V01-00021 also funded this work. References [1] A.A. Watson, G.W.J. Fleet, N. Asano, R.J. Molyneux, R.J. Nash, Phytochemistry 56 (2001) 265‒295 and references cited therein. [2] S. Park, I.-S. Myeong, W.-H. Ham, Org. Biomol. Chem. 22 (2024) 894‒926 and references cited therein. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 103 [3] B.G. Davis, Tetrahedron: Asymmetry 20 (2009) 652‒671and references cited therein. [4] J.-Z. Wang, B. Cheng, A. Kato, M. Kise, Y. Shimadate, Y.-M. Jia, Y.-X. Li, G.W. Fleet, C.-Y., Yu, Eur. J. Med. Chem. 233 (2022) 114230 and references cited therein. [5] J. Gonda, J. Elečko, M. Martinková, M. Fábian, Tetrahedron Lett. 57 (2016) 2895–2897. [6] W. Humphrey, A. Dalke, K. Schulten, J. Mol. Graphics 14 (1996) 33‒38 Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 104 SESSION 7 PHYSICAL CHEMISTRY Preparation and Surface Characterization of PLA-Coated Zinc V. Cakyovaa*, R. Orinakovaa aDepartment of Physical Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 041 54, Košice, Slovak Republic *viktoria.cak[email protected]pjs.sk Internal fixators are specifically engineered to support bone repair and regeneration by stabilizing fracture sites, thereby promoting faster healing. These medical devices are manufactured in various forms, such as screws, pins, plates, and other fixation systems[1]. Among biodegradable metals, magnesium, zinc, and iron are the most commonly used [2]. Zinc exhibits a moderate degradation rate and good biocompatibility. However, its relatively low mechanical strength and the uncontrolled release of Zn2+ ions limit its effectiveness as a base material for biomedical applications. Therefore, surface modification is often required to effectively regulate the biodegradation behaviour of Zn-based materials [3]. Several surface modification strategies have been developed to tune the corrosion rate of Zn-based materials, such as inorganic coatings, ceramic coatings, polymer coatings, composite coatings, and sol-gel coatings. Among these strategies, polymer coatings are effective and straightforward, as they provide corrosion control, enhanced biocompatibility, and drug delivery potential. In particular, poly(lactic acid) (PLA) is attractive due to its long history of safe use in resorbable medical devices, including stents, sutures, and bone-fixation devices [4]. In this study, zinc specimens were fabricated via powder metallurgy technique and subsequently coated with a 5 wt.% PLA solution using spin-coating and needleless electrospinning techniques to compare the resulting surface morphology. The surface morphology of uncoated and coated Zn samples was studied using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray analysis (EDS). Figure 1a shows SEM image of the surface of an uncoated Zn sample, at 100 – times magnification, exhibiting characteristic parallel grinding marks. The corresponding EDS analysis confirms the presence of Zn along with O caused by surface oxidation. Figure 1b and c show SEM images of PLA spin – coated on the surface of Zn sample at 100 – and 5000 – times magnification, respectively. The PLA coating forms a porous layer composed of interconnected pores of different sizes. EDS analysis confirms the presence of C and O, supporting the presence of the PLA polymer layer. Figure 1d and e show SEM images of the surface of Zn coated with PLA nanofibers, prepared by needleless electrospinning, at 100 – and 5000 – times magnification, respectively. The surface is homogenously covered with randomly oriented, smooth PLA nanofibers with thickness ranging from approximately 0.15 µm to 1 µm. Compared with spin-coated film, the electrospun layer exhibits a more open, three – dimensional fibrous structure that allows partial exposure of the underlying Zn surface. The corresponding EDS analysis confirms the presence of Zn, O, and C. Figure 1 SEM images of the Zn sample before coating at 100 x magnification (a), after spin coating at 100 x (b) and 5000 x (c), and PLA electrospun nanofibers at 100 x (d) and 5000 x magnification. Acknowledgements This work was supported by the Slovak Research and Development Agency under the project APVV-24-0033 and by the Internal Research Grant of the Faculty of Science of P.J. Šafárik University (VVGS-2025-3485). References [1] S.A. Salahi, N.H. Nemati, G. Khalaj, S.M. Abbasi, AIP Adv. 15 (2025). [2] P. Das, D.K. Pathak, P. Sharma, P.M. Pandey, Corros. Rev. 43 (2025) 279–300. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 105 [3] Y. Shi, Z. Xue, P. Li, S. Yang, D. Zhang, S. Zhou, Z. Guan, Y. Li, L.N. Wang, J. Mater. Res. Technol. 25 (2023) 3670–3687. [4] P. Kumar, G. Anne, M.R. Ramesh, M. Doddamani, A. Prabhu, J. Coat. Technol. Res. 21 (2024) 1525–1537. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 112 SESSION 7 PHYSICAL CHEMISTRY Comparative Analysis of Separator Materials and Their Influence on the Electrochemical Performance of Lithium–Sulfur Cells under Low-Electrolyte Conditions J. Lescinskya*, V. Niscakovaa, A. Strakova Fedorkovaa aDepartment of Physical Chemistry, Faculty of Sciences, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 04154 Kosice, Slovak Republic *jakub.lescinsk[email protected]pjs.sk The ongoing effort to develop lightweight and miniaturized lithium–sulfur (Li–S) batteries has intensified the need to optimize internal cell components for improved energy density and stable operation. Among these, the separator structure plays a key role in controlling ion transport, electrolyte distribution, and suppression of the polysulfide shuttle effect [1]. In systems with a low electrolyte volume, where wetting and ionic conductivity are limited, the separator design becomes particularly crucial for ensuring efficient electrochemical utilization of sulfur and longterm cycling stability [2]. This work presents a comparative study of Li–S cells assembled with two different separators—glass fiber GF/A and polymeric Celgard® 2325—under reduced electrolyte conditions, representing a step toward miniaturized and electrolyte-lean Li–S systems. Electrochemical characterization using cyclic voltammetry (CV) and galvanostatic cycling (GCPL) shown in Figure 1 revealed distinct performance differences between the two configurations. The cell with the GF/A separator achieved an initial discharge capacity of only 200,7 mAh g⁻¹, accompanied by rapid capacity fading and unstable cycling behavior, attributed to the limited ion transport through its thick fibrous structure and insufficient wetting under low-electrolyte conditions. In contrast, the Celgard® 2325-based cell exhibited a markedly higher initial capacity of 768,2 mAh g⁻¹ at 0,1 C, with 85,4 % capacity retention after 35 cycles, demonstrating improved electrolyte utilization, better ionic conductivity, and more homogeneous activation of the cathode material. The comparison clearly indicates that the separator type critically affects the electrochemical response of Li–S cells operating with limited electrolyte. While GF/A shows favorable polysulfide adsorption and stability in highelectrolyte configurations, Celgard® 2325 offers superior compatibility with electrolyte-lean and miniaturized cell designs, enabling more efficient energy storage per unit mass and volume—an essential factor for the next generation of high-energy, lightweight Li–S batteries. Acknowledgements This work was funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project SUNFLOWERS No. 09I02-03-V01-00022 and KEGA 002UPJS-4/2024. References [1] Ji, X., & Nazar, L. F. (2010). Advances in Li–S batteries. Journal of Materials Chemistry, 20(44), 9821– 9826. [2] Peng, H.-J., Huang, J.-Q., Cheng, X.-B., & Zhang, Q. (2017). Review on high-loading and lean-electrolyte Li–S batteries. Advanced Energy Materials, 7(24), 1700260. https://doi.org/10.1002/aenm.201700260 Figure 1 Comparison of Discharge Profiles for Li–S Cells with a) GF/A and b) Celgard® 2325 separators at 0,1 C. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 113 SESSION 7 PHYSICAL CHEMISTRY Modification of screen-printed electrodes for electrochemical gentamicin detection I. Mojzisovaa*, J. Demeterovaa, J. Shepaa, I. Sisolakovaa, R. Orinakovaa,b aDepartment of Physical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice bCentre of Polymer Systems, University Institute, Tomas Bata University in Zlín, Třída Tomáše Bati 5678, 76001 Zlín, Czech Republic *ivana.mo[email protected]pjs.sk Orthopaedic implants have played a crucial role in modern medicine, offering solutions for bone repair and joint replacement. Despite their clinical benefits, implant-associated infections remain a persistent and serious complication that can threaten the success of surgical procedures. To mitigate these risks, the development of antibacterial coatings capable of localised drug delivery has gained increasing attention. Gradual release of antibiotics at the implant site can reduce systemic toxicity and enhance therapeutic efficacy [1]. However, the quantitative evaluation of antibiotic release during the degradation of these coatings remains technically challenging due to the very low concentrations involved. The aim of this study was to develop an electrochemical sensor for gentamicin detection through the modification of a screen-printed carbon electrode (SPCE) with Cr-containing metal-organic frameworks (Cr-MOF), multiwalled carbon nanotubes (MWCNTs), and Nafion. The surface of the working electrode was modified by the drop-casting method in three different ways. In the first case, the electrode was modified with a Cr-MOF complex, which was fixed onto the surface using a Nafion layer. In the second case, MWCNTs were applied to the electrode surface, followed by a Nafion layer after drying. The third modification represented a combination of the previous approaches, where the working electrode surface was modified with a suspension prepared by mixing MWCNTs and Cr-MOF in a Nafion solution. In this work the effective surface area of unmodified and modified SPCEs was investigated using cyclic voltammetry (CV) in a 5 mM K₃[Fe(CN)₆]/K₄[Fe(CN)₆] solution within a potential range of 0–1.6 V at a scan rate of 0.1 V/s. Subsequently, CV measurements were also performed in a 300 µM gentamicin solution prepared in PBS in order to monitor the anodic current response associated with gentamicin oxidation on the studied electrodes. The active surface area was highest for the unmodified SPCE electrode. Surface modification led to the occupation of active sites by the less conductive MOF material, resulting in a decrease in the electroactive area (Figure 1c). The oxidation of gentamicin is represented by a peak in the potential range of 0.2–0.5 V. The highest anodic current response for gentamicin oxidation was observed for the electrode modified with the combination of CrMOF and MWCNTs bound with Nafion (Figure 1). This synergistic effect can be attributed to the binding capability of Cr-MOF, which enables efficient adsorption of gentamicin, while the MWCNTs facilitate effective electron transfer. This modification showed as the most effective modification for the electrochemical determination of gentamicin. Figure 1 Cyclic voltammogram of a) 5 mM K₃[Fe(CN)₆]/K₄[Fe(CN)₆] solution and b) 300 µm gentamicin sulphate solution in PBS c) comparison of the active surface area. Acknowledgements This research was sponsored by the NATO Science for Peace and Security Programme under grant id. G6106. References [1] X. Chen, J. Zhou, Y. Qian, L.Z. Zhao, Mater Today Bio. 19 (2023) 100586. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 114 SESSION 7 PHYSICAL CHEMISTRY Bimetallic phosphides sulfur cathode for Li-S battery V. Niscakovaa*, A. Guboovab, J. Lescinskya, A. Strakova Fedorkovaa, R. Orinakovaa, aPavol Jozef Šafárik University in Košice, Department of Physical chemistry, Šrobárova 2, 040 01, Kosice bInstitute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01, Košice, Slovakia *[email protected] Sulfur, a naturally abundant, low-cost, and environmentally friendly material, presents a compelling alternative to conventional Li-ion cathode materials [1]. However, significant challenges persist that impede the practical implementation of lithium-sulfur batteries (LSBs) like insulating nature of sulfur, volume changes, and performance degradation caused by the shuttle effect. Using carbon material would effectively improve conductivity of sufur electrode. However, a potential drawback of employing porous carbon materials is an increase in battery volume. Therefore, it is very important to design suitable support materials for sulphur fixation [2]. Metal phosphides have emerged as promising materials for addressing the challenges associated with lithiumsulfur batteries. The superior electronic and ionic conductivity of metal phosphides, coupled with their ample polar sites, facilitates efficient charge transfer and catalytic activity, improving the overall performance of lithium-sulfur batteries [3]. The presence of highly electronegative phosphorus atoms within the metal phosphide lattice results in electron withdrawal from the metal centers, leading to the formation of electron-rich surfaces and multi-electron orbitals. This electronic environment facilitates the adsorption of electropositive species, such as Li+ ions, and enhances electronic conductivity, making metal phosphides promising candidates for high-performance catalytic applications [4]. In this study, composite sulfur cathodes with the addition of bimetallic phosphide (MoFeP) were prepared for application in lithium-sulfur batteries. A simple sol-gel method followed by sintering in two sintering steps (in air and reduction in hydrogen atmosphere) was used to prepare this bimetallic phosphide. The fabricated sulfur electrodes were subjected to detailed electrochemical analysis using cyclic voltammetry and galvanostatic cycling. Test cells were assembled utilizing pre-fabricated electrodes as working electrodes (WE), while lithium metal served as both the counter (CE) and reference electrode (RE). The electrode was charged and discharged between 1.8 and 2.8 V at different C-rates. Also the cyclic voltammetry was done between 1.8 and 2.8 V at 0.1 mV.s-1. The initial capacity of the electrode with the addition of MoFeP at 0.1 C was 530 mAh g-1. Figure 1 Polysulfide redox transitions and SEM image of the MoFeP. Acknowledgements Funded by the Slovak Research and Development Agency under the Contract no. DS-FR-24-0004, by the project KEGA 002UPJŠ-4/2024 and EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project SUNFLOWERS No. 09I02-03-V01-00022. References [1] X. Wang, H. Liu, L. Bai, Q. Wang, and S. Guo, “Hollow nickel-cobalt bimetal phosphides as a confined polysulfide reactor for high-performance lithium-sulfur batteries,” Electrochim. Acta, vol. 397, Nov. 2021, doi: 10.1016/j.electacta.2021.139303. [2] L. Liu et al., “Transition Metal Phosphides: The Rising Star of Lithium–Sulfur Battery Cathode Host,” Small, vol. 20, no. 17, pp. 1–21, 2024, doi: 10.1002/smll.202308564. [3] Q. Yang et al., “Unveiling the synergistic catalysis essence of trimetallic Fe-Co-Ni phosphides for lithium– sulfur chemistry,” Chem. Eng. J., vol. 452, Jan. 2023, doi: 10.1016/j.cej.2022.139638. [4] Y. Yang et al., “Recent advances and strategies of metal phosphides for accelerating polysulfide redox and regulating Li plating,” Jul. 01, 2024, Elsevier B.V. doi: 10.1016/j.ccr.2024.215836. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 115 SESSION 7 PHYSICAL CHEMISTRY Investigation of the Hydrogen Evolution Reaction Kinetics on a High-Entropy Catalyst M. Parackovaa*, R. Orinakovaa, M. Streckovab aDepartment of Physical Chemistry, Institute of Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic *[email protected] Hydrogen is integral to numerous industrial processes, including oil refining, ammonia and methanol synthesis, and the Fischer-Tropsch process. Its annual demand has tripled over the past 50 years and is projected to increase fivefold, surpassing 500 million tons by 2050. Today, most hydrogen is produced via coal gasification and steam methane reforming, which are cost-effective but emit substantial CO2. Water electrolysis powered by renewable energy offers a more sustainable route but is currently more expensive. Reducing its cost will require the development of cheaper catalysts [1–3]. The aim of this work was to examine the effect of temperature on the kinetics of the hydrogen evolution reaction (HER) on a non-critical-feedstock-based high-entropy material in an alkaline media. This material was prepared from Cu, Fe, Ni, Mo, and Zn precursors via sol-gel autocombustion. HER kinetics on this material was investigated over 298.15 – 333.15 K by electrochemical impedance spectroscopy at -300 mV vs RHE in 1 M KOH, using a three-electrode setup with a rotating glassy carbon disk electrode modified with catalytic ink as the working electrode. The working-electrode catalyst loading was 1 mg·cm-2. The obtained data were well fitted by the equivalent circuit presented in Figure 1B, with chi-square values below 0.0056 for all fits. As shown in Figure 1A, HER kinetics is controlled by charge transfer across the entire temperature range studied. The polarization resistance decreases markedly at lower temperatures (298.15– 323.15 K), from 155 Ω to 28.3 Ω, whereas at higher temperatures (323.15–333.15 K) the change is minimal (1.1 Ω), indicating that improved performance can be achieved with a slight increase in electrolyte temperature. Figure 1 A) Nyquist diagrams for the prepared material 1 M KOH at −300 mV vs RHE over 298.15–333.15 K; B) equivalent circuit consisting of the solution resistance (Rs), a constant phase element (CPE), and the polarization resistance (Rp) used to fit Nyquist diagrams. Acknowledgements This research was supported by Internal Scientific Grant System - ESGD Program of Pavol Jozef Šafárik University in Košice (vvgs-2023-2957) funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V05-00008 and the Scientific Grant Agency of Ministry of Education, Science, Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (VEGA) under project No. 1/0057/25. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 116 References [1] M. M. Hossain Bhuiyan and Z. Siddique, Int J Hydrogen Energy 102 (2025) 1026-1044. [2] M. Shao et al., ChemCatChem 17 (2025). [3] M. Alsunousi and E. Kayabasi, Int J Hydrogen Energy 54 (2024)1169–1178. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 117 SESSION 7 PHYSICAL CHEMISTRY Defect-Driven Metal Doping in Graphite : A First-Principles Perspective for Vanadium Redox Flow Battery Systems N. Podrojkovaa*, A. Strakova Fedorkovaa aDepartment of Physical Chemistry, Pavol Jozef Šafárik University in Košice, Dr. Kostlivého 1, 040 01 Košice, Slovakia *[email protected] The electrochemical performance of all-vanadium redox flow batteries (VRFBs) is closely linked to the physicochemical characteristics of their electrode materials [1]. Graphite-based electrodes are widely employed due to their high electrical conductivity, chemical stability and cost-effectiveness [2]. However, their inert basal planes limit their electrochemical activity towards vanadium redox reactions. To overcome this limitation, recent advances suggest that metal doping and defect engineering can substantially improve the catalytic performance by modifying the surface and introducing active sites for charge transfer [3, 4]. However, the atomic-scale mechanisms underlying these improvements remain largely underexplored. To address this gap, this study aims to elucidate the atomic-scale mechanisms underlying metal incorporation and stabilization in graphite electrodes using density functional theory (DFT) simulations, specifically employing the Quantum Espresso package. Pristine and defect-containing surfaces were modelled to evaluate the influence of vacancy defects on dopant incorporation energetics and electronic structure. Focus will be placed on post-transition metal dopants, bismuth (Bi), tin (Sn), lead (Pb), and indium (In), due to their experimentally demonstrated ability to influence vanadium redox kinetics. These elements can also mitigate parasitic side reactions, such as hydrogen evolution, by selectively altering the reaction pathways by tuning the surface energetics. Through a systematic analysis of defect formation energies, dopant-defect interactions, and electronic structure characteristics, this study establishes a theoretical framework connecting defect-assisted metal doping with improved VRFB functionality, offering insights crucial for designing more efficient, durable, and selective carbonbased electrodes for next-generation systems. Acknowledgements This work was supported by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00109. References [1] A. W. Bayeh et al., J. Energy Storage 102 (2024) 114026 [2] M. Inagaki, F. Kang, Chapter 3 – Engineering and Applications of Carbon Materials, in: Materials Science and Engineering of Carbon: Fundamentals, 2nd Ed. (Inagaki M, Kang F., ed.). Elsevier, Massachusetts 539, page 219. [3] J. Xu et al., Energy Fuels 35 (2021) 8617-8633. [4] Y. Jiang et al., Carbon Energy 6 (2024) e537. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 118 SESSION 7 PHYSICAL CHEMISTRY Electrospun high-entropy oxide ceramic nanofibers I. Shepaa*, K. Nemesha, E. Mudraa, P. Hviscovaa, R. Smolkob, D. Drencakovac, M. Lisnichuka,d, D. Albova, F. Kromkaa, K. Balazsie aInstitute of Materials Research of SAS, Slovak Academy of Sciences, Watsonova 47, Košice 040 01, Slovakia bInstitute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Košice 040 01, Slovakia cInstitute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, Košice 040 01, Slovakia dDepartment of Condensed Matter Physics, Institute of Physics, Faculty of Science, P.J. Šafárik University in Košice, Park Angelinum 9, Košice 041 54, Slovakia eInstitute of Technical Physics and Materials Science, HUN-REN Center for Energy Research, Konkoly Thege Miklós út 29-33, Budapest H-1121, Hungary *[email protected] This research details the synthesis and comprehensive structural analysis of oxide ceramic nanofibers with a complex composition. These materials integrate transition metals from Group IV (Ti, Zr, Hf) and Group V (Ta, Nb), with the core objective being the achievement of a pure, single-phase ceramic structure with a composition of TiZrHfNbTaO11, thus resulting in a high entropy oxide. The foundational step involved preparation of composite PAN/MeOx precursor fibers (where Me represents the transition metal) in a rapid, one-step reactive needleless electrospinning. The subsequent transformation into porous MeOx ceramic nanofibers was achieved through controlled calcination. To define the required thermal profile, Thermogravimetric Analysis (TGA) was used to evaluate the thermal stability of the precursor fibers. The critical finding was that pure ceramic fibers, without carbon residues, resulted from calcination performed at 600 °C. Elevated heat treatment temperatures were observed to accelerate the crystallization of the ceramic component, leading to the gradual emergence of multiple distinct phases. Morphological changes and mean diameter variation were quantified using Electron Microscopy across the different calcination temperatures. Energy-dispersive X-ray spectroscopy (EDX) was used in conjunction with microscopy to verify elemental composition. Furthermore, nitrogen adsorption measurements established the surface area, while X-ray Diffraction (XRD) was crucial for confirming both the phase composition and the degree of crystallinity in the heat-treated fibers. Based on the obtained results, the range of potential applications for the prepared HEO fibers was evaluated. Acknowledgements Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00579. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 119 SESSION 7 PHYSICAL CHEMISTRY Electrochemical Insulin Detection Using CuO 550 and CuO 550/CNTs Fiber-Based Sensors L. Slabejovaa*, J. Shepaa, I. Sisolakovaa, E. Mudrab aDepartment of Physical Chemistry, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 040 01 Košice, Slovak Republic bInstitute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic *laura.slabejov[email protected] Insulin, a hormone that regulates the concentration of glucose in the blood [1], is an essential marker for the diagnosis of diabetes mellitus and various metabolic disorders. Its detection often employs carbon electrodes modified with metal or oxide nanoparticles. Cu(II) and Mn(II) ions are capable of forming interactions with insulin´s amino acid residues, altering the electrochemical response and enhancing signal detection [2]. For all experiments in this study, carbon electrodes fabricated by screen printing (SPCE 11L, DropSens, Metrohm) were used, with their surfaces modified by drop casting with CuO 550 and CuO 550/CNTs. CuO 550 was prepared using a multi-stage hydrometallurgical recycling process in collaboration with colleagues from SAS. Modified electrodes were used to study the electrochemical mechanism of insulin oxidation via cyclic voltammetry (CV). Electrochemical responses of the prepared electrodes were obtained using CV at a scan rate of 100 mV.s-1. The results (Figure 1) indicate that in both cases, the voltammogram obtained in the presence of insulin shows an oxidation peak around 0.45 V, corresponding to insulin oxidation. However, for the CuO 550/CNTs electrode, the electrochemical response was significantly stronger. Figure 1 Cyclic voltammogram of PBS and PBS with 10 µM insulin on CuO-modified electrodes at a scan rate of 100 mV.s-1 (A – CuO 550 without CNTs, B – CuO 550 with CNTs). Screen-printed carbon electrodes were effectively modified with CuO 550 and CuO 550/CNTs. Electrochemical analysis demonstrated that incorporating CNTs into the CuO modification markedly enhanced the electrodes’ responsiveness toward insulin. Acknowledgements This work was funded by the EU NextGenerationEU through the Recovery and Resilience Plan of the Slovak Republic under project no. 09-I05-03-V02-00047. References [1] R. Orinakova, F. Chovancová, I. Šišoláková, and J. Shepa, "Study of Insulin Electrochemical Reaction Mechanism on Modified Ni-Chit/SPCE Electrode," ECS Meeting Abstracts, vol. MA2024-02, no. 64, pp. 42884288, 2024, doi: 10.1149/MA2024-02644288mtgabs. [2] Z. Rong et al., "Electrochemical investigation on the complexes of Cu(II), Mn(II), Ca(II), and Mg(II) with insulin," Journal of Molecular Structure, vol. 1335, 2025, doi: 10.1016/j.molstruc.2025.141992. Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 120 LIST OF POSTERS Novel Trends in Chemistry, Research and Education at Faculty of Science of P. J. Šafárik University in Košice 2025 121 LIST OF AUTHORS A Albov 118 Alifah 46 Almasi 27, 28, 48, 49, 52, 55, 56, 58, 61, 62, 63, 65, 66, 68, 70, 71, 72, 74, 76, 78 Ambro 27, 34, 62 Andreanna 28, 62 Andrejev 48, 49 Antosova 33 B Bago Pilatova 93, 95, 98, 100, 102 Balazsi 118 Bano 24 Barillova 18 Bazel 21 Bednarikova 7, 23, 33 Benova 46, 51, 60, 74, 79 Bezeg 21 Bilcik 62 Borovska 23 Budovska 33, 83, 88 C Cakyova 104 Capkova 52 Cernak 59 Chovancova 107 Chovanova 88 Czetnerova 53 D Demeterova 106, 113 Diko 76 Divarova 19 Drencakova 118 E Elecko 80 Estkova 74 F Fabian 85, 87 Felcikova 24, 35 Filip 17 G Gajdosova 19 Ganajova 45 Gancar 23 Gavazov 19 Gazova 7, 23, 33 Georgiou 87 Gizela Varchol 28 Goga 80 Gondova 18 Guboova 114 Gucky 25, 89 Gulyasova 34, 62 Guziurova 22 Gyepes 69 H Harbulakova 54 Heredosova 26 Herman 27 Hlavkova 55 Holeczyova 56 Horak 31 Hovan 24 Huntosova 27, 28, 31, 34, 37, 62, 63, 87 Hviscova 118 I Icsova 20 J Jager 89 Jampilek 6 Janovec 32, 89 Jascisak 12, 17 Jasnakova 108 Jurasekova 28, 62 K Kareem 33 Kharadza 110 Kiraly 46, 51, 52, 58, 60, 65, 66, 68, 70, 71 Kmetova 8 Kollarova 29 Korabecny 25 Kozminski 7 Kozurkova 25, 30, 32, 89 Krempaska 22 Kresakova 59 Krochtova 89 Kromka 118 Kubackova 21 Kubickova 43 Kuchar 64, 93, 95, 98, 100 Kupcova 22 Kusnirova 89 Kuzderova 69 L Lescinsky 112, 114 Letosnikova 45 Li 28 Liptakova 60 Liska 82 Lisnichuk 118 Litecka 59, 95, 100 M Ma 23 Macajova 62 Malcekova 61 Malinak 10 Martinkova 85, 87, 90, 92, 93, 95, 97, 98, 100, 102 Matajova 30 Matikova Malarova 53 Meta 62 Mezencev 102 Michalcin 90, 100 Michalkova 83, 88, 89 Michelova 64 Migasova 27, 28, 63 Mihokova 25 Minko 95, 97 Miskufova 88, 89 Mojzis 83, 88, 89 Mojzisova 113 Monfort 9 Mudra 118, 119 Murgasova 22 N Nemergut 34, 35, 37 Nemesh 118 Niculaes 43 Niedzialek 7 Niscakova 112, 114 O Obsatnik 58, 65, 66, 68, 70 Ocenas 83 Ocenasova 83 Olejarova 31 Ondrejkovicova 92, 95, 97, 98