ANALYSIS OF AMINO-ACID ENANTIOMERS DERIVED FROM ANTITUMOR ANTIBIOTICSUSING CHIRAL CAPILLARY ELECTROPHORESIS

The chiral separation of enantiomeric forms of derivatized amino acids have been achieved based on a metal-chelate chiral capillary electrop horetic method and a cyclodextrin mediated host-guest interaction appr oach in micellar electrokinetic chromatography (MEKC) mode with laser- induced fluorescence detection. This approach has been applied to the determination of enantiomeric forms of amino acids derived from novel depsipeptide antitumor antibiotics, BMY-45012 and its analogs. Amino a cids were analyzed by complete hydrolysis and the hydrolysate was deri vatized with either dansyl chloride for UV absorbance detection or flu orescein isothiocyanate for laser based fluorescence detection. The pr esence of several amino acids, serine and beta-hydroxyl-N-methy-valine in the proposed structure have been confirmed as D-serine and L-beta- hydroxyl-N-methy-valine enantiomeric forms by both chiral capillary el ectrophoresis (chiral CE) and MEKC approaches. A non-chiral amino acid , sarcosine, was also confirmed. These methodologies provide a quick a nd sensitive approach for the determination of amino acids racemizatio n of pharmaceutical natural products and have proven to be useful for structural elucidation refinement. (C) 1997 Elsevier Science B.V.