Establishment and Molecular Modeling Study of Cyclodextrin-Based Synergistic Enantioseparation Systems with Three New Amino Acid Chiral Ionic Liquids as Additives in Capillary Electrophoresis

Chiral ionic liquids (CILs) have attracted more and more attention due to their superior performance as chiral additives in capillary electrophoresis. In this work, based on the cyclodextrin (CD) derivatives and three new amino acid CILs (trifluoroacetate-L-Hydroxyproline, nitric acid-L-Hydroxyproline and trifluoroacetate-L-threonine), the new synergistic systems were established for chiral drug separation. In contrast to the traditional single glucosyl-β-CD (Glu-β-CD) separation system, the CIL/Glu-β-CD synergistic systems achieved improved resolution of three model drug racemates. Some experimental variables, such as CIL concentration, Glu-β-CD concentration, buffer pH, applied voltage, and the type and proportion of organic modifier, were optimized in the trifluoroacetate-L-Hydroxyproline/Glu-β-CD synergistic system. In addition, the recognition process in the synergistic system was studied through the molecular modeling method.