Highlighting the role of the chlorine substituents in the glycopeptide antibiotic balhimycin for chiral recognition in capillary electrophoresis

Abstract

The vancomycin-type glycopeptide antibiotic balhimycin (I) and its dehaloanalogue dechlorobalhimycin (III), which is characterized by the total substitution of the two chlorine atoms of I by hydrogen, were employed as chiral selectors for the enantioresolution of 11 racemic dansyl amino acids and six 2-arylpropionic acid nonsteroidal anti-inflammatory racemic drugs by CE. The observed enantioresolution capability of I for all test analytes is clearly higher than that observed for III. This result suggests that chlorine substituents of I played a major role in the enantioresolution of these test analytes. A dimerization-based mechanism is proposed in order to explain this phenomenon. The two chlorine substituents of each monomer, which mutually penetrate into the cavity of the adjacent molecule of the dimer, are assumed to promote dimerization and as a consequence also enantioresolution.

Review of aqueous chiral electrokinetic chromatography (EKC) with an emphasis on chiral microemulsion EKC

“…A variant of vancomycin, balhimycin, was used to study the effect of chlorine groups on enantioresolution [156]. Chiral separations of dansyl amino acids and 2-arylpropionic acids were also carried out with dechlorobalhimycin, a non-chlorinated analog of balhimycin.…”

Application of antibiotics as chiral selectors for capillary electrophoretic enantioseparation of pharmaceuticals: a review

“…Jiang et al . (, ) reported pI values 7.85, 7.85 and 7.80 for balhimycin, bromobalhimycin and dechloroalhimycin, respectively.…”

“…The effect of differences in the linking position, type of sugar moieties and halogen substitution on enantiorecognition ability of balhimycin, bomobalhimycin, dechlorobalhimycin and vancomycin was studied by Jiang et al . (, ). The amino sugar moieties are found to play a key role in stabilizing dimer formation of glycopeptides (Shiozawa et al ., ) and several examples of enantioresolution with vancomycin‐type CSs have shown that higher dimerization results in higher enantioresolution (Kang et al ., ; Reilly et al ., ; Slama et al ., ).…”

Use of neutral capillaries for the enantioseparation ofN-benzoylated amino acids by capillary electrophoresis with bromobalhimycin as chiral selector

“…At selected pH (normally lower than the pI of the chiral selector), the acidic analytes will move out of the chiral selector zone and pass through the detection window first without the interference from the glycopeptide antibiotic. On the other hand, the positively charged inner surface could also minimize the adsorption of the glycopeptide used as chiral selector onto the capillary wall via electrostatic repulsion between the coating and the glycopeptide . Even though the partial filling technique combined with the co‐EOF electrophoresis and the dynamic coating techniques could solve the problem of detection sensitivity to a certain extent, the relatively narrow separation window brought about another problem to the analysts.…”