TY - JOUR AU - Kovács, Lajos TI - Russell Marker. Második rész TS - Második rész JF - MAGYAR KÉMIKUSOK LAPJA J2 - MAGY KEM LAP VL - 79 PY - 2024 IS - 2 SP - 52 EP - 55 PG - 4 SN - 0025-0163 UR - https://m2.mtmt.hu/api/publication/34779851 ID - 34779851 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Kovács, Lajos TI - Russell Marker. Első rész TS - Első rész JF - MAGYAR KÉMIKUSOK LAPJA J2 - MAGY KEM LAP VL - 79 PY - 2024 IS - 1 SP - 7 EP - 11 PG - 5 SN - 0025-0163 UR - https://m2.mtmt.hu/api/publication/34735122 ID - 34735122 N1 - "A közlemény részletes hivatkozásai a publikáció angol nyelvű változatban találhatók: Lajos Kovács:“The Campfire Stories of Russell Marker, a Pioneer of Chemistry.”Notes Rec. 77 (2023): 1–25. https://doi.org/10.1098/rsnr.2023.0022" LA - Hungarian DB - MTMT ER - TY - JOUR AU - Kovács, Lajos TI - Tudományos séták Európában JF - MAGYAR KÉMIKUSOK LAPJA J2 - MAGY KEM LAP VL - 78 PY - 2023 IS - 7-8 SP - 235 EP - 240 PG - 6 SN - 0025-0163 UR - https://m2.mtmt.hu/api/publication/34074812 ID - 34074812 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Kovács, Lajos TI - The campfire stories of Russell Marker, a pioneer of chemistry JF - NOTES AND RECORDS-THE ROYAL SOCIETY JOURNAL OF THE HISTORY OF SCIENCE J2 - NOTES REC PY - 2023 SN - 0035-9149 DO - 10.1098/rsnr.2023.0022 UR - https://m2.mtmt.hu/api/publication/33927397 ID - 33927397 AB - The maverick American chemist Russell Earl Marker (1902–1995) is known for his studies on the fragmentation of organic mercury compounds, establishing the concept of the octane number, investigating the rearrangements of hydrocarbons and exploring the relationship between optical rotation and the configuration of organic compounds. His greatest achievement, however, is the elaboration of seminal isolation and synthetic methods of an important class of natural products that helped found a new industry, based on the pharmaceutical chemistry of steroids. The nomadic life of this extraordinary man demonstrates that the enormous obstacles thwarting the progress of science and technology can be surmounted by serendipity, acumen and devotion. However, his premature retirement from chemistry is a warning sign that every scientist is vulnerable and even the toughest man's perseverance can fade if the conditions worsen. LA - English DB - MTMT ER - TY - JOUR AU - Szeltner, Zoltán AU - Ferenc, Györgyi AU - Juhász, Tünde AU - Kupihár, Zoltán AU - Váradi, Zoltán AU - Szüts, Dávid AU - Kovács, Lajos TI - Probing telomeric-like G4 structures with full or partial 2′-deoxy-5-hydroxyuridine substitutions JF - BIOCHIMIE J2 - BIOCHIMIE VL - 214 PY - 2023 IS - Part A SP - 33 EP - 44 PG - 12 SN - 0300-9084 DO - 10.1016/j.biochi.2023.01.009 UR - https://m2.mtmt.hu/api/publication/33697937 ID - 33697937 N1 - Institute of Enzymology, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, Budapest, H-1117, Hungary Nucleic Acid Synthesis Laboratory, Biological Research Centre, Eötvös Loránd Research Network, Temesvári Krt. 62, Szeged, H-6726, Hungary Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, Budapest, H-1117, Hungary Department of Medicinal Chemistry, University of Szeged, Dom Tér 8, Szeged, H-6720, Hungary Export Date: 13 March 2023 CODEN: BICMB Correspondence Address: Szüts, D.; Institute of Enzymology, Magyar Tudósok Körútja 2, Hungary; email: szuts.david@ttk.hu Correspondence Address: Kovács, L.; Department of Medicinal Chemistry, Dom Tér 8, Hungary; email: kovacs.lajos@med.u-szeged-hu Funding details: Eötvös Loránd Tudományegyetem, ELTE Funding details: National Research, Development and Innovation Office, 2018–1.2.1-NKP-2018-00005, K128801 Funding text 1: We thank Mihály Kovács and Gábor Harami (ELTE) for supplying us with BLM helicase. This work was supported by the National Research Development and Innovation Office of Hungary (grants no. K128801 and 2018–1.2.1-NKP-2018-00005 ). Funding text 2: We thank Mihály Kovács and Gábor Harami (ELTE) for supplying us with BLM helicase. This work was supported by the National Research Development and Innovation Office of Hungary (grants no. K128801 and 2018–1.2.1-NKP-2018-00005). AB - Guanine quadruplexes (G4s) are stable four-stranded secondary DNA structures held together by noncanonical G-G base tetrads. We synthesised the nucleoside analogue 2′-deoxy-5-hydroxyuridine (H) and inserted its phosphoramidite into telomeric repeat-type model oligonucleotides. Full and partial substitutions were made, replacing all guanines in all the three tetrads of a three-tier G4 structure, or only in the putative upper, central, or lower tetrads. We characterised these modified structures using CD, UV absorbance spectroscopy, native gel studies, and a capture oligo-based G4 disruption kinetic assay. The strand separation activity of BLM helicase on these substituted structures was also investigated. Two of the partially H-substituted constructs adopted G4-like structures, but displayed lower thermal stabilities compared to unsubstituted G4. The construct modified in its central tetrad remained mostly denatured, but the possibility of a special structure for the fully replaced variant remained open. H substitutions did not interfere with the G4-resolving activity of BLM helicase, but its efficiency was highly influenced by construct topology and even more by the G4 ligand PhenDC3. Our results suggest that the H modification can be incorporated into G quadruplexes, but only at certain positions to maintain G4 stability. The destabilizing effect observed for 2′-deoxy-5-hydroxyuridine indicates that the cytosine deamination product 5-hydroxyuracil and its nucleoside counterpart in RNA (5-hydroxyuridine), might also be destabilizing in cellular DNA and RNA quadruplexes. The kinetic assay employed in this study can be generally employed for a fast comparison of the stabilities of various G4s either in their free or ligand-bound states. © 2023 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM) LA - English DB - MTMT ER - TY - JOUR AU - Kupihár, Zoltán AU - Ferenc, Györgyi AU - Petrovicz, Vencel László AU - Fáy, Viktória R. AU - Kovács, Lajos AU - Martinek, Tamás AU - Hegedüs, Zsófia TI - Improved Metal-Free Approach for the Synthesis of Protected Thiol Containing Thymidine Nucleoside Phosphoramidite and Its Application for the Synthesis of Ligatable Oligonucleotide Conjugates JF - PHARMACEUTICS J2 - PHARMACEUTICS VL - 15 PY - 2023 IS - 1 PG - 16 SN - 1999-4923 DO - 10.3390/pharmaceutics15010248 UR - https://m2.mtmt.hu/api/publication/33597958 ID - 33597958 N1 - Funding Agency and Grant Number: National Research, Development and Innovation Office of Hungary [NKFIH PD 135324, K 128801, K 134754]; Ministry of Innovation and Technology of Hungary through the National Research, Development and Innovation Fund [TKP2021-EGA-32] Funding text: This work received funding from the National Research, Development and Innovation Office of Hungary-NKFIH PD 135324 (Z.H.), K 128801 (L.K.) and K 134754 (T.A.M.). Support by the Ministry of Innovation and Technology of Hungary through the National Research, Development and Innovation Fund (TKP2021-EGA-32) is acknowledged. AB - Oligonucleotide conjugates are versatile scaffolds that can be applied in DNA-based screening platforms and ligand display or as therapeutics. Several different chemical approaches are available for functionalizing oligonucleotides, which are often carried out on the 5′ or 3′ end. Modifying oligonucleotides in the middle of the sequence opens the possibility to ligate the conjugates and create DNA strands bearing multiple different ligands. Our goal was to establish a complete workflow that can be applied for such purposes from monomer synthesis to templated ligation. To achieve this, a monomer is required with an orthogonal functional group that can be incorporated internally into the oligonucleotide sequence. This is followed by conjugation with different molecules and ligation with the help of a complementary template. Here, we show the synthesis and the application of a thiol-modified thymidine nucleoside phosphoramidite to prepare ligatable oligonucleotide conjugates. The conjugations were performed both in solution and on solid phase, resulting in conjugates that can be assembled into multivalent oligonucleotides decorated with tissue-targeting peptides using templated ligation. LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Lajos TI - From Peptide Nucleic Acids to Supramolecular Structures of Nucleic Acid Derivatives JF - CHEMICAL RECORD J2 - CHEM REC VL - 23 PY - 2023 IS - 1 PG - 13 SN - 1527-8999 DO - 10.1002/tcr.202200203 UR - https://m2.mtmt.hu/api/publication/33158565 ID - 33158565 LA - English DB - MTMT ER - TY - JOUR AU - Z. Orosz, Gábor AU - Németh, Veronika AU - Kovács, Lajos AU - Somogyi, Zoltán AU - Korom, Erzsébet TI - Guided inquiry-based learning in secondary-school chemistry classes: a case study JF - CHEMISTRY EDUCATION RESEARCH AND PRACTICE J2 - CHEM EDUC RES PRACT VL - 24 PY - 2023 IS - 1 SP - 50 EP - 70 PG - 21 SN - 1109-4028 DO - 10.1039/D2RP00110A UR - https://m2.mtmt.hu/api/publication/33075306 ID - 33075306 AB - Guided inquiry-based learning has been shown to be a promising method for science education; however, despite its advantages it is rarely used in chemistry teaching in Hungary. One of the reasons for this is the lack of tried-and-tested inquiry-based teaching materials with detailed guides that teachers can readily use in their classrooms. As part of a four-year research project, new teaching materials were designed to foster scientific reasoning and scientific process skills in chemistry education in Hungary. From these materials, in this study, a guided inquiry-based chemistry task was tested with 9th-grade students ( N = 88) who had no previous experience with the method. Before the activity, the students’ mid-term grades were collected, and the Lawson Classroom Test of Scientific Reasoning (LCTSR) was administered to describe the sample. During the activity, students worked in groups ( n = 21). Data were collected through content analysis of the student worksheets, classroom observations using a rubric, and student questionnaires to explore the learning paths and identify possible obstacles. Our findings support that guided inquiry learning is suitable for students who are new to the method if appropriate scaffolding is given. The data showed the phases of the inquiry cycle in which more guidance is necessary. Formulating hypotheses, recording observations, and evaluating the hypotheses based on the evidence were found to be the most critical steps in the learning process. More than half of the groups disregarded the collected evidence and accepted their original hypotheses, despite their unproven validity, suggesting that they did not understand the true nature of the scientific inquiry. Chemistry grades and the LCTSR scores could not predict reliably the students’ success in solving the inquiry task. The results of the student questionnaire showed that the students enjoyed the inquiry session. They mostly found their work successful, but they overestimated the level of their inquiry skills in some cases. LA - English DB - MTMT ER - TY - JOUR AU - Váradi, Zoltán AU - Paragi, Gábor AU - Kupihár, Zoltán AU - Kele, Zoltán AU - Kovács, Lajos TI - Synthesis of Heterocycles and Nucleosides Forming Higher—Order Structures JF - CHEMISTRY PROCEEDINGS J2 - CHEM PROC VL - 8 PY - 2022 IS - 1 PG - 6 SN - 2673-4583 DO - 10.3390/ecsoc-25-11705 UR - https://m2.mtmt.hu/api/publication/32818711 ID - 32818711 LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Lajos AU - Betyár, Gábor AU - Korom, Erzsébet TI - An Integrated Database of Common Chemicals and Chemistry Demonstrations and Student Experiments Used in Hungary JF - JOURNAL OF CHEMICAL EDUCATION J2 - J CHEM EDUC VL - 98 PY - 2021 IS - 12 SP - 3813 EP - 3823 PG - 11 SN - 0021-9584 DO - 10.1021/acs.jchemed.1c00540 UR - https://m2.mtmt.hu/api/publication/32554077 ID - 32554077 LA - English DB - MTMT ER -