CHROMATOGRAPHIC METHODS FOR MONITORING THE OPTICAL ISOMERS OF UNUSUALAROMATIC-AMINO-ACIDS

Unusual aromatic amino acids (phenylalanine, tyrosine and tryptophan a nalogues, and analogues containing tetraline, 1,2,3,4-tetrahydroisoqui noline or 1,2,3,4-tetrahydro-2-carboline skeletons) were synthesized i n racemic or chiral form. The enantiomers of these unusual aromatic am ino acids were separated by different chromatographic methods. The gas chromatographic analyses were based on separation on a Chirasil-L-Val column, using N-trifluoroacetyl-isobutyl esters of amino acids, while high-performance liquid chromatography was carried out either on a Cr ownpak CR(+) chiral column, or on an achiral column for the separation of diastereomeric derivatives formed with 1-fluoro-2,4-dinitrophenyl- 5-L-alanine amide or 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isot hiocyanate. (C) 1998 Elsevier Science B.V.