L- and D-cysteine derivatives of beta-cyclodextrin: different molecular recognition properties of their copper(II) complexes for amino acids

The two epimers of beta-cycIodextrin 6-functionalized with L- or D-cysteine (6-S-(L)-cysteine-6-deoxy-beta-cyclodextrin and (6-S-(D)-cysteine-6-deoxy-beta-cyclodextrin) were synthesized. Their binary and ternary copper(II) complexes with amino acids were characterized by electronic, circular dichroism and ESR spectroscopies. The binary copper(II) complexes were used as eluents in Ligand exchange chromatography to test their ability to resolve racemate mixtures of unmodified amino acids. High performance Liquid chromatography separation of L/D-TrpO(-) was achieved only when the complex of the D-cysteine derivative was used as the eluent. (C) 1998 Elsevier Science S.A. All rights reserved.