ISSN:
0173-0835
Keywords:
Capillary Zone electrophoresis
;
Chiral separations
;
Amino acids
;
Macrocyclic antibiotics
;
Vancomycin
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
The properties of the macrocyclic antibiotic vancomycin, used as a chiral selector, were studied with aminoquinolycarbamate derivatives of amino acids, containing sulfur and selenium, as well as with other organic ions. Vancomycin combines the ability to resolve fully ionized anionic enantiomers, typical of proteins, with excellent separation efficiency, exceeding that of cyclodextrins. It allows better than baseline chiral separations of several anionic analytes within 3-5 min. The resolving power of vancomycin results from its great skill in discriminating enantiomers rather than from high affinities to the separated enantiomers. The association constants of vancomycin are of the same order of magnitude, 102 L/mol, as that found for β-cyclodextrin (β-CD). The difference in association constants of separated cystine enantiomers with vancomycin, 2 × 102 L/mol, is one order of magnitude higher than that of enantiomers separated with β-CD. Analytically convenient mobility differences up to 1-2 × 109 m2V-1S-1, with only one of the enantiomers appreciably decelerated, are obtained at submillimolar vancomycin concentrations. Typical separation efficiencies are close to 250 000 theoretical plates per meter of capillary. Deceleration of various organic ions by millimolar vancomycin implies that chiral separations with vancomycin need not be restricted to carboxylic acids. The vancomycin-analyte interactions are strongly affected by the chemical composition and concentration of the buffer. An additional experimental variable, highly effective in manipulating the separation selectivity of analytes, is the buffer pH.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elps.1150170708
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