TY - JOUR AU - Németi, Gábor AU - Berkecz, Róbert AU - Péter, Antal AU - Lindner, Wolfgang AU - Ilisz, István TI - Cinchona Alkaloid-Based Zwitterionic Chiral Stationary Phases Applied for Liquid Chromatographic Enantiomer Separations: An Overview JF - METHODS IN MOLECULAR BIOLOGY J2 - METHODS MOL BIOL VL - 2994 PY - 2026 SP - 293 EP - 327 PG - 35 SN - 1064-3745 DO - 10.1007/978-1-0716-5023-3_15 UR - https://m2.mtmt.hu/api/publication/36464815 ID - 36464815 LA - English DB - MTMT ER - TY - JOUR AU - Tanács, Dániel AU - Németi, Gábor AU - Berkecz, Róbert AU - Bozsó, Zsolt AU - Tóth, Gábor AU - Lindner, Wolfgang AU - Péter, Antal AU - Ilisz, István TI - Comparative study of zwitterionic Cinchonane-based ion-exchangers for liquid chromatographic enantioseparations of free fluorinated tryptophanes: mechanistic and thermodynamic insights under green mobile phase conditions JF - JOURNAL OF CHROMATOGRAPHY A J2 - J CHROMATOGR A VL - 1771 PY - 2026 PG - 12 SN - 0021-9673 DO - 10.1016/j.chroma.2026.466811 UR - https://m2.mtmt.hu/api/publication/36960881 ID - 36960881 LA - English DB - MTMT ER - TY - JOUR AU - Németi, Gábor AU - Berkecz, Róbert AU - Ozsvár, Dániel AU - Szakonyi, Zsolt AU - Lindner, Wolfgang AU - Misicka, Aleksandra AU - Tymecka, Dagmara AU - Tóth, Géza AU - Péter, Antal AU - Ilisz, István TI - High-Performance Liquid Chromatographic Separation of Stereoisomers of ß-Methyl-Substituted Unusual Amino Acids Utilizing Ion Exchangers Based on Cinchona Alkaloids JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 26 PY - 2025 IS - 9 PG - 17 SN - 1661-6596 DO - 10.3390/ijms26094004 UR - https://m2.mtmt.hu/api/publication/36105462 ID - 36105462 AB - Novel peptides based on common amino acid building blocks may serve as possible drug candidates; however, their flexible structures may require stabilization via the incorporation of conformational constraints. The insertion of unusual amino acids is a feasible option that may provide improved pharmacokinetic and pharmacodynamic properties of such peptide-type drugs. The stereochemical purity of these kinds of building blocks must be verified by an efficient separation technique, such as high-performance liquid chromatography. Here, we present and discuss the results of the stereoselective separation mechanism of ß-methylated phenylalanine (ß-MePhe), tyrosine (ß-MeTyr), 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (ß-MeTic), and cyclohexylalanine (ß-MeCha) together with non-methylated Phe, Tyr, Tic, and Cha applying Cinchona alkaloid-based chiral stationary phases (CSPs). The studied zwitterionic CSPs acting as ion exchangers provided optimal performance in the polar ionic mode when methanol or a mixture of methanol and acetonitrile was utilized as the mobile phase together with organic acid and base additives. It was found that the basicity of small amines applied as mobile phase additives did not directly influence the chromatographic ion exchange concept. However, the size of the amines and their concentration led to a reduced retention time following the principles of ion exchange chromatography. On the basis of a systematic study of the effects of the eluent composition on the chromatographic behavior, important structure–retention and enantioselectivity relationships could be revealed. Through a temperature study, it has become evident that the composition of the eluent and the structure of analytes markedly affect the thermodynamic properties. LA - English DB - MTMT ER - TY - CHAP AU - Németi, Gábor AU - Le Minh, Tam AU - Szakonyi, Zsolt AU - Péter, Antal AU - Ilisz, István ED - Alapi, Tünde ED - Berkecz, Róbert ED - Ilisz, István TI - Comparing the effects of green solvents in HPLC with polysaccharide–type chiral stationary phases for enantioseparation of compounds of pharmaceutical relevance T2 - Proceedings of the 31st International Symposium on Analytical and Environmental Problems PB - Szeged University (Hungary) CY - Szeged SN - 9789636880781 PY - 2025 SP - 76 EP - 76 PG - 1 UR - https://m2.mtmt.hu/api/publication/36388990 ID - 36388990 LA - English DB - MTMT ER - TY - CONF AU - Ilisz, István AU - Németi, Gábor AU - Péter, Antal AU - Berkecz, Róbert TI - Ion exchanger-based chiral stationary phases applied for enantioselective separations T2 - Book of Abstracts: 14th Balaton Symposium on High-Performance Separation Methods PY - 2025 SP - L-17 PG - 1 UR - https://m2.mtmt.hu/api/publication/36389889 ID - 36389889 LA - English DB - MTMT ER - TY - CONF AU - Németi, Gábor AU - Le Minh, Tam AU - Zsolt, Szakonyi AU - Péter, Antal AU - Ilisz, István TI - Investigation of HPLC enantioseparations of pyrimidine and diaminopyrimidine derivatives on polysaccharide–type chiral stationary phases utilizing green solvents T2 - Book of Abstracts: 14th Balaton Symposium on High-Performance Separation Methods PY - 2025 SP - P-04 PG - 1 UR - https://m2.mtmt.hu/api/publication/36390033 ID - 36390033 LA - English DB - MTMT ER - TY - THES AU - Németi, Gábor TI - Enantioselective high-performance liquid chromatographic separations utilizing Cinchona alkaloid- and polysaccharide-based chiral stationary phases [Nagyhatékonyságú folyadékkromatográfiás enantioszelektív elválasztások cinkóna alkaloid és poliszacharid alapú királis állófázisok alkalmazásával] PB - Szegedi Tudományegyetem PY - 2025 DO - 10.14232/phd.12457 UR - https://m2.mtmt.hu/api/publication/36459505 ID - 36459505 LA - English DB - MTMT ER - TY - JOUR AU - Németi, Gábor AU - Berkecz, Róbert AU - Le Minh, Tam AU - Szakonyi, Zsolt AU - Péter, Antal AU - Ilisz, István TI - High-performance liquid chromatographic enantioseparation of azole analogs of monoterpene lactones and amides focusing on the separation characteristics of polysaccharide-based chiral stationary phases JF - JOURNAL OF CHROMATOGRAPHY A J2 - J CHROMATOGR A VL - 1717 PY - 2024 PG - 9 SN - 0021-9673 DO - 10.1016/j.chroma.2024.464660 UR - https://m2.mtmt.hu/api/publication/34535772 ID - 34535772 N1 - Institute of Pharmaceutical Analysis, Interdisciplinary Excellence Centre, University of Szeged, Somogyi u. 4, Szeged, H-6720, Hungary Institute of Pharmaceutical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Eötvös u. 6, Szeged, H-6720, Hungary Export Date: 5 February 2024 CODEN: JCRAE Correspondence Address: Ilisz, I.; Institute of Pharmaceutical Analysis, Somogyi u. 4, Hungary; email: ilisz.istvan@szte.hu Funding details: 6752 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding details: Innovációs és Technológiai Minisztérium Funding details: National Research, Development and Innovation Office, K137607, TKP2021-EGA-32 Funding text 1: This work was supported by the National Research, Development and Innovation Office-NKFIA through project K137607. Project no. TKP2021-EGA-32 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-EGA funding scheme. This work was supported by the ÚNKP-21-4 New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund. The publication was funded by the University of Szeged Open Access Fund (No. 6752). LA - English DB - MTMT ER - TY - CONF AU - Ilisz, István AU - Németi, Gábor AU - Tanács, Dániel AU - Péter, Antal AU - Berkecz, Róbert TI - Liquid chromatography-based enantioselective separations for pharmaceutical analysis T2 - Congressus Pharmaceuticus Hungaricus XVII. and EUFEPS Annual Meeting 2024 PB - Magyar Gyógyszerésztudományi Társaság (MGYT) C1 - Budapest PY - 2024 SP - 84 EP - 84 PG - 1 UR - https://m2.mtmt.hu/api/publication/34892211 ID - 34892211 LA - English DB - MTMT ER - TY - CONF AU - Németi, Gábor AU - Ozsvár, Dániel AU - Berkecz, Róbert AU - Péter, Antal AU - Wolfgang, Lindner AU - Ilisz, István TI - HPLC Study of the Enantioselective separation of β-methyl-substituted amino acids applying ion exchanger-based chiral stationary phases T2 - 13th Balaton Symposium on High-Performance Separation Methods PY - 2023 PG - 1 UR - https://m2.mtmt.hu/api/publication/34380012 ID - 34380012 LA - English DB - MTMT ER -