COMPARISON AND MODELING STUDY OF VANCOMYCIN, RISTOCETIN-A, AND TEICOPLANIN FOR CE-ENANTIOSEPARATIONS

The structurally related glycopeptide antibiotics vancomycin, ristocet in A, and teicoplanin can all be used as chiral selectors in capillary electrophoresis (CE). Both experimental and modeling studies were don e to elucidate their similarities and differences, There are identifia ble morphological differences in the aglycon macrocyclic portions of t hese three compounds. In addition, there are other structural distinct ions that can affect their CE enantioselectivity, migration times, and efficiency. Teicoplanin is the most distinct of the three and is the only one that is surface active. Its aggregational properties appear t o affect its enantioselectivity among other things. The similar but no t identical structures of the three glycopeptides produce similar but not identical enantioselectivities. This leads to the empirically usef ul ''principle of complementary separations'', in which a partial reso lution with one chiral selector can be brought to baseline with one of the others. Overall, ristocetin A appears to have the greatest applic ability for CE enantioseparations.