Salt dependence on vancomycin‐herbicide enantiomer binding: Capillary electrophoresis study and theoretical approach

Abstract

In a previous paper, a mathematical model was developed for the estimation of binding constants by capillary electrophoresis (Guillaume and Peyrin, Anal. Chem. 1999, 71, 2046-2052). This model was applied to determinate the binding constant of the guest-vancomycin complex as well as the degree of complexation n(c) (percent of complexed guest). In this work, the guest molecule were a series of acid herbicide enantiomers (aryloxypropionic, aryloxyphenoxypropionic, and aminopropionic acid). The effects of the run buffer salt concentration on the herbicide-vancomycin binding was clearly described by the determination of specific physicochemical parameters as well as thermodynamic data. These results demonstrate that a better understanding of the interactions involved in the guest molecule-vancomycin binding allows to optimize the enantiomeric separation of this chiral guest molecule.

Enantioselective aptameric molecular recognition material: Design of a novel chiral stationary phase for enantioseparation of a series of chiral herbicides by capillary electrochromatography

“…In a previous report [64] it was demonstrated that an acetate buffer was suitable for analyzing in CE the enantioseparation of the compounds studied in this paper. Thus, the BGE solutions consisted of a 2 mM acetate buffer adjusted to pH 6.0, 10 mM NaCl, with different fraction of ACN v/v.…”

Use of CE for the determination of binding constants

“…Among above plotting methods, the nonlinear binding isotherm (Eq. (9)), x ‐reciprocal plot and the titration curve plot were reported for multivariate binding interactions 37–47.…”

Effect of metals on herbicides–α‐synuclein association: A possible factor in neurodegenerative disease studied by capillary electrophoresis

“…In accordance with Uvesky et al [33], the simplest of these is that the herbicide itself directly interacts with a-synuclein. Assuming instantaneous equilibrium between herbicide and a-synuclein (see Section 2.4), the apparent association constant K of herbicide-a-synuclein binding can be analysed with the change in the electrophoretic mobility m of the injected a-synuclein (Syn) on complexation with herbicides (H) present in the run buffer using the following equation [34]:…”