Amino Acid Derivatives of β-Cyclodextrin

The syntheses of the heptaamino acid-substituted β-cyclodextrins per-6-[(phenylalanyl)amino]-β-cyclodextrin (6), per-6-cysteinyl-β-cyclodextrin (7), as well as the per-2,3-dimethyl-per-6-cysteinyl-β-cyclodextrin (12) are described. The amino acids were coupled to the primary face of the β-cyclodextrin torus using the backbone carboxylic acid functionality of phenylalanine and the side chain thiol group of cysteine. In the case of the heptacysteinyl derivatives, polyzwitterionic compounds were obtained and shown to be highly water soluble.