Enantioseparation in Capillary Electrophoresis Using 6-Oligo- (lactic acid)cyclomaltoheptaose as a Chiral Selector

A novel β-cyclodextrin (β-CD) derivative modified with a degradable and biocompatible oligo(lactic acid) (OLA) group, 6-oligo(lactic acid)cyclomaltoheptaose (6-OLA-β-CD), was successfully synthesized and used as a chiral selector for the capillary electrophoretic (CE) resolution (Rs) of several basic analytes. The primary purpose of the research was to explore the capability of the 6-OLA-β-CD as a chiral selector for comparisons with β-CD and HP-β-CD. Substitution with the oligo(lactic acid) group at the sixth hydroxyl sites of the CD is aimed at influencing the magnitude and selectivity of the analyte-CD interactions. The chiral resolution was strongly influenced by the concentration of the CDs and buffer pH. The effects of the substitution degree (DS) and the chain length (n) of the 6-oligo(lactic acid) groups of 6-OLA-β-CD on separations were also investigated.