CHIRAL SEPARATION OF DL-PEPTIDES AND ELANTIOSELECTIVE INTERACTIONS BETWEEN TEICOPLANIN AND D-PEPTIDES IN CAPILLARY ELECTROPHORESIS

Teicoplanin has been evaluated as a selector for enantioseparation of di- and tripeptide derivatives in capillary electrophoresis. Separatio n variables such as type of buffer, pH, concentrations of teicoplanin and organic modifier were examined. Optimal separation conditions were obtained by means of factorial design experiments. The effects of tei coplanin concentrations below and above its critical micellar concentr ation (CMC) and of acetonitrile (ACN) on the separation were demonstra ted. The use of a high concentration of ACN resulted not only in incre ased selectivity, but also in improved separation efficiency. Electroo smotic flow was observed to be largely independent of the concentratio ns of teicoplanin under the optimized conditions. Good repeatability o f migration times was obtained. The interactions between teicoplanin a nd D and L peptides were studied, and it was found that, for some pept ides, teicoplanin exhibited enantioselective interaction only with the D-form. Somewhat lower separation efficiencies were thus observed for the strongest interacting (D-form) peptides. Chiral separation of 15 DL-peptide derivatives was achieved in less than 10 min.