Impact of substituent position in monosubstituted α‐cyclodextrins on enantioselectivity in capillary electrophoresis

In this study, our three recently synthesized regiospecifically monosubstituted carboxymethyl‐α‐cyclodextrins ( CMACD s) were successfully applied for the enantiomeric separation of several biologically important low‐molecular weight compounds by capillary electrophoresis. The enantioselectivity of the individual monosubstituted CMACD s added into the background electrolyte ( BGE ) was studied and compared with the mixture of three monosubstituted CMACD s and with native α‐cyclodextrin at p H of the BGE ranging from 2.5 to 11. Our experiments revealed a significant influence of the position of the carboxymethyl group on the α‐cyclodextrin skeleton on the enantioselectivity for all the studied analytes. Interestingly, the least common 3 I ‐ O regioisomer was revealed as the most effective chiral selector.