Dobó Máté, Molnár Gergely, Mhammad Ali, Dombi Gergely, Mirzahosseini Arash, Szabó Zoltán-István, Tóth Gergő
Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes E. Str. 9, H-1092 Budapest, Hungary.
Center for Pharmacology and Drug Research & Development, Semmelweis University, H-1092 Budapest, Hungary.
Int J Mol Sci. 2025 Jul 25;26(15):7217. doi: 10.3390/ijms26157217.
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)-α-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-2-propanol and methanol-ethanol 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.
研究了三种质子泵抑制剂（奥美拉唑、兰索拉唑和雷贝拉唑）作为含有手性亚砜基团的示例分子，在极性有机液相色谱模式下于七种不同的多糖固定相（手性拆分柱OD和OJ；手性拆分柱AD、AS和IA；鲁克斯纤维素-2和-4）上的分离情况。使用了不同的醇类，如甲醇、乙醇、1-丙醇、2-丙醇及其组合作为洗脱剂。经过方法优化后，成功地将半制备对映体拆分应用于这三种质子泵抑制剂，以收集各个对映体。对洗脱顺序反转、热力学参数、洗脱剂混合物的影响以及保留时间和选择性的滞后现象进行了详细研究。使用含有直链淀粉三[（S）-α-甲基苄基氨基甲酸酯]手性选择剂的手性拆分柱AS，在所有四种纯洗脱剂中都实现了所研究对映体的分离，其中甲醇的效果最佳。在许多情况下，观察到了对映体洗脱顺序的反转。除了依赖手性选择剂的反转外，还观察到了依赖洗脱剂的反转。值得注意的是，即使将甲醇替换为乙醇也会改变对映体洗脱顺序。在几种情况下还观察到了焓控和熵控对映体拆分；然而，未观察到温度依赖性洗脱顺序反转。在甲醇-2-丙醇和甲醇-乙醇洗脱剂混合物中，进一步研究了直链淀粉型柱上保留和选择性的滞后现象。无论使用何种洗脱剂混合物，在所有直链淀粉柱上都观察到了这种现象。计算了滞后率并用于比较不同系统的滞后行为。多变量统计分析表明，在手性拆分柱AS在测试的色谱柱中表现出最明显的对映选择性行为，这可能是由于氨基甲酸酯部分与芳族取代基之间不存在直接连接。本研究有助于理解导致对映体识别的机制，这对于开发新的手性固定相和一般的手性高效液相色谱方法开发至关重要。
