{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T13:22:14Z","timestamp":1788355334462,"version":"build-2803163510"},"reference-count":44,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2025,7,25]],"date-time":"2025-07-25T00:00:00Z","timestamp":1753401600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003827","name":"National Research, Development and Innovation Office, Hungary","doi-asserted-by":"publisher","award":["NKFIH FK 146930"],"award-info":[{"award-number":["NKFIH FK 146930"]}],"id":[{"id":"10.13039\/501100003827","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003827","name":"National Research, Development and Innovation Office, Hungary","doi-asserted-by":"publisher","award":["2024-2.1.1-EK\u00d6P-2024-00004"],"award-info":[{"award-number":["2024-2.1.1-EK\u00d6P-2024-00004"]}],"id":[{"id":"10.13039\/501100003827","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003827","name":"University Research Scholarship Programme of the Ministry for Culture and Innovation from the Source of the National Research, Development and Innovation Fund","doi-asserted-by":"publisher","award":["NKFIH FK 146930"],"award-info":[{"award-number":["NKFIH FK 146930"]}],"id":[{"id":"10.13039\/501100003827","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003827","name":"University Research Scholarship Programme of the Ministry for Culture and Innovation from the Source of the National Research, Development and Innovation Fund","doi-asserted-by":"publisher","award":["2024-2.1.1-EK\u00d6P-2024-00004"],"award-info":[{"award-number":["2024-2.1.1-EK\u00d6P-2024-00004"]}],"id":[{"id":"10.13039\/501100003827","id-type":"DOI","asserted-by":"publisher"}]},{"name":"J\u00e1nos Bolyai Research Scholarship of the Hungarian Academy of Sciences","award":["NKFIH FK 146930"],"award-info":[{"award-number":["NKFIH FK 146930"]}]},{"name":"J\u00e1nos Bolyai Research Scholarship of the Hungarian Academy of Sciences","award":["2024-2.1.1-EK\u00d6P-2024-00004"],"award-info":[{"award-number":["2024-2.1.1-EK\u00d6P-2024-00004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The separation of three proton pump inhibitors (omeprazole, lansoprazole, and rabeprazole) as exemplified molecules containing chiral sulfoxide groups was investigated in polar organic liquid chromatographic mode on seven different polysaccharide stationary phases (Chiralcel OD and OJ; Chiralpak AD, AS, and IA; Lux Cellulose-2 and -4). Different alcohols, such as methanol, ethanol, 1-propanol, 2-propanol, and their combinations, were used as eluents. After method optimization, semi-preparative enantioseparation was successfully applied for the three proton pump inhibitors to collect the individual enantiomers. A detailed investigation was conducted into elution order reversal, thermodynamic parameters, the effect of eluent mixtures, and the hysteresis of retention time and selectivity. Using Chiralpak AS, containing the amylose tris[(S)-\u03b1-methylbenzylcarbamate] chiral selector, the separation of the investigated enantiomers was achieved in all four neat eluents, with methanol providing the best results. In many cases, a reversal of the enantiomer elution order was observed. In addition to chiral-selector-dependent reversal, eluent-dependent reversal was also observed. Notably, even replacing methanol with ethanol altered the enantiomer elution order. Both enthalpy- and entropy-controlled enantioseparation were also observed in several cases; however, temperature-dependent elution order reversal was not. The hysteresis of retention and selectivity was further investigated on amylose-type columns in methanol\u20132-propanol and methanol\u2013ethanol eluent mixtures. The phenomenon was observed on all amylose columns regardless of the eluent mixtures employed. Hystereticity ratios were calculated and used to compare the hysteresis behaviors of different systems. Multivariate statistical analysis revealed that Chiralpak AS exhibited the most distinct enantioselective behavior among the tested columns, likely due to the absence of a direct connection between the carbamate moiety and the aromatic substituent. The present study aided in understanding the mechanisms leading to enantiomer recognition, which is crucial for developing new chiral stationary phases and chiral HPLC method development in general.<\/jats:p>","DOI":"10.3390\/ijms26157217","type":"journal-article","created":{"date-parts":[[2025,7,25]],"date-time":"2025-07-25T14:40:02Z","timestamp":1753454402000},"page":"7217","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Enantioseparation of Proton Pump Inhibitors by HPLC on Polysaccharide-Type Stationary Phases: Enantiomer Elution Order Reversal, Thermodynamic Characterization, and Hysteretic Effect"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2573-445X","authenticated-orcid":false,"given":"M\u00e1t\u00e9","family":"Dob\u00f3","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. Str. 9, H-1092 Budapest, Hungary"},{"name":"Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gergely","family":"Moln\u00e1r","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. Str. 9, H-1092 Budapest, Hungary"},{"name":"Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0291-8184","authenticated-orcid":false,"given":"Ali","family":"Mhammad","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. Str. 9, H-1092 Budapest, Hungary"},{"name":"Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3308-4245","authenticated-orcid":false,"given":"Gergely","family":"Dombi","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. Str. 9, H-1092 Budapest, Hungary"},{"name":"Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3281-8435","authenticated-orcid":false,"given":"Arash","family":"Mirzahosseini","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. Str. 9, H-1092 Budapest, Hungary"},{"name":"Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8740-0212","authenticated-orcid":false,"given":"Zolt\u00e1n-Istv\u00e1n","family":"Szab\u00f3","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Industry and Management, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, Gh. Marinescu 38, 540139 Targu Mures, Romania"},{"name":"Sz-Imfidum Ltd., Lunga nr. 504, 525401 Lunga, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5341-319X","authenticated-orcid":false,"given":"Gerg\u0151","family":"T\u00f3th","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Semmelweis University, H\u0151gyes E. 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