Vancomycin dimerization and chiral recognition studied by high-performance liquid chromatography.
The retention and separation of D,L-dansylvaline enantiomers (used as test solutes) were investigated using silica gel as stationary phase and vancomycin as chiral mobile-phase additive. A retention model was developed to describe the mechanistic aspects of the interaction between solute and vancomycin in the chromatographic system. It considered the formation of vancomycin dimers both "free" in the mobile phase and adsorbed on silica. By fitting the model equation to experimental data, it appeared clearly that the approach taking into account the vancomycin dimerization described accurately the retention behavior of the compounds. The examination of the model equation parameters showed that the glycopeptide dimerization increased the enantioselectivity by a factor of approximately 3.7. This study demonstrated the preponderant role of the vancomycin dimerization on the chiral recognition process of D,L-dansylvaline. Also, an additional analysis on a vancomycin chiral stationary phase indicated that the addition of vancomycin in the mobile phase promoted a greater enantioselectivity mediated by the formation of dimers in the stationary phase.
Slama
Ines
I
Département de Pharmacochimie Moléculaire, UMR CNRS 5063, UFR de Pharmacie de Grenoble, La Tronche, France.
Dufresne
Christelle
C
Jourdan
Eric
E
Fahrat
Fahrat
F
Villet
Annick
A
Ravel
Anne
A
Grosset
Catherine
C
Peyrin
Eric
E
D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D012044:Regression Analysis; D015203:Reproducibility of Results; D013237:Stereoisomerism; D014640:Vancomycin / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D014640:Vancomycin