Derivatized Vancomycin Stationary Phases for LC Chiral Separations
Abstract
In this work, synthetic and natural chiral selectors were combined to form two different chiral stationary phases (CSPs). These were made by bonding R- or S-(1-naphthylethyl) carbamate (R-NEC or S-NEC)-derivatized vancomycin molecules to a silica gel support. The two CSPs were evaluated using a set of 60 enantiomeric pairs. The results were compared to the ones obtained with the commercial underivatized vancomycin CSP. Three chromatographic modes were used : (i) the normal-phase mode using a nonpolar mobile phase with different ratios of hexane and ethanol ; (ii) the reversed-phase mode with hydro-organic mobile phases ; and (iii) the polar aprotic organic mode with nonaqueous acetonitrile plus small amounts of methanol and an acid and/or base to control retention and selectivity. It is shown that the polarity of the underivatized vancomycin phase is higher than that of the two R- and S-NEC-derivatized CSPs. In the pH range 4-7, there is no ionization change of the chiral selector for the three CSPs. 43% of the studied compounds were resolved by the NEC-derivatized phases when they could not be resolved by the vancomycin CSP. However, the enantiorecognition for 12% of the compounds on the native vancomycin CSP was lost upon NEC derivatization. 45% of the studied compounds were resolved by the NEC-derivatized and native CSPs. The NEC derivatization procedure may block some useful active sites on the vancomycin molecule. Also, the R- and S-NEC moieties are chiral themselves and can contribute additional interaction sites not available on the native vancomycin molecule.
Recommended Citation
A. Berthod et al., "Derivatized Vancomycin Stationary Phases for LC Chiral Separations," Talanta, vol. 43, no. 10, pp. 1767 - 1782, Elsevier, Jan 1996.
The definitive version is available at https://doi.org/10.1016/0039-9140(96)01974-1
Department(s)
Chemistry
Keywords and Phrases
Chiral drugs; Chiral separations; Stationary phase; Vancomycin
International Standard Serial Number (ISSN)
0039-9140
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Elsevier, All rights reserved.
Publication Date
01 Jan 1996
Comments
U.S. Department of Energy, Grant DE FG02 8SER13819