Comparison and Modeling Study of Vancomycin, Ristocetin A, and Teicoplanin for CE Enantioseparations

Abstract

The structurally related glycopeptide antibiotics vancomycin, ristocetin A, and teicoplanin can all be used as chiral selectors in capillary electrophoresis (CE). Both experimental and modeling studies were done to elucidate their similarities and differences. There are identifiable morphological differences in the aglycon macrocyclic portions of these three compounds. In addition, there are other structural distinctions 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 to affect its enantioselectivity among other things. The similar but not identical structures of the three glycopeptides produce similar but not identical enantioselectivities. This leads to the empirically useful "principle of complementary separations", in which a partial resolution with one chiral selector can be brought to baseline with one of the others. Overall, ristocetin A appears to have the greatest applicability for CE enantioseparations.

Chiral separation by chromatographic and electromigration techniques. A Review

“…The semirigid basket-shaped aglycan, which has hydrophobic properties, enables the formation of host-guest inclusion complexes and there are pendant polar arms, which can form hydrogen bonds. Ionic, dipole-dipole, p-p, hydrophobic interactions and steric repulsion are assumed to take effect [398]. A comprehensive description of the properties of these selectors and their applications to the chiral separation of a broad spectrum of compounds is given in several specialized reviews [399][400][401].…”

Chiral Analyses of Pollutants by Capillary Electrophoresis

“…This allows for an excellent potential to resolve a greater variety of racemates. The possible interactions involved in the formation of diastereomeric complexes are -complexation, hydrogen bonding, inclusion complexation, dipole interactions, steric interactions and anionic and cationic binding [38] Accordingly, the diastereomeric complexes possessing different physical and chemical properties separated on the capillary path (achiral phase). The different migration times of the formed diastereomeric complexes depend on their sizes, charges and interaction with the capillary wall and as a result these complexes eluted at different time intervals.…”

HPLC separation of amino acid enantiomers and small peptides on macrocyclic antibiotic‐based chiral stationary phases: A review

“…This is a macrocyclic glycopeptide antibiotic complex produced as a fermentation product by a strain of Streptomyces candidus ( [62] b) [31], [36] [31], [36] b) [31] a)…”

“…It contains seven aromatic rings, two of which have chlorine-substituents and four of which are ionizable phenolic moieties. The aglycone contains a single primary amine which (together with the phenolic moieties) maintains its charge at the pHs normally used in HPLC (i. e. pH 3. nin is a mixture of five closely related analogs, designated T-A 2-1 through T-A 2-5 [35,36]. They differ by approximately 20 molecular mass units because of the variation in length (i. e. C 10 -C 11 ) and substituent groups of the acyl side-chain attached to the amino sugar.…”