title: Affinity capillary electrophoresis and fluorescence spectroscopy for studying enantioselective interactions between omeprazole enantiomer and human serum albumin.
abstract: Baseline separation of omeprazole (OME) enantiomers was achieved by affinity capillary electrophoresis (ACE), using human serum albumin (HSA) as the chiral selector. The influence of several experimental variables such as HSA concentration, the type and content of organic modifiers, applied voltage and running buffer concentration on the separation was evaluated. The binding of esomeprazole (S-omeprazole, S-OME) and its R-enantiomer (R-omeprazole, R-OME) to HSA under simulated physiological conditions was studied by ACE and fluorescence spectroscopy which was considered as a reference method. ACE studies demonstrated that the binding constants of the two enantiomers and HSA were 3.18 × 103M-1and 5.36 × 103M-1, respectively. The binding properties including the fluorescence quenching mechanisms, binding constants, binding sites and the number of binding sites were obtained by fluorescence spectroscopy. Though the ACE method could not get enough data when compared with the fluorescence spectrum method, the separation and binding studies of chiral drugs could be achieved simultaneously via this method. This study is of great significance for the investigation and clinical application of chiral drugs.
authors.affiliation: Department of Analytical Chemistry, P.R. China Pharmaceutical University, Nanjing, P.R. China.|Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, P.R. China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Analytical Chemistry, P.R. China Pharmaceutical University, Nanjing, P.R. China.|Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, P.R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Hong
authors.affiliation: Department of Analytical Chemistry, P.R. China Pharmaceutical University, Nanjing, P.R. China.|Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, P.R. China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Analytical Chemistry, P.R. China Pharmaceutical University, Nanjing, P.R. China.|Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Nanjing, P.R. China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ji
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D009853:Omeprazole / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013237:Stereoisomerism
chemical_list: D012709:Serum Albumin; D009853:Omeprazole
keywords: Affinity capillary electrophoresis; Chiral separation; Enantioselective interactions; Fluorescence spectroscopy; Human serum albumin