Synthesis of branched cyclomaltooligosaccharide carboxylic acids (cyclodextrin carboxylic acids) by microbial oxidation

Novel branched cyclomaltooligosaccharide carboxylic acid (cyclodextrin carb oxylic acid) derivatives were synthesized by microbial oxidation using Pseu dogluconobacter saccharoketogenes to oxidize five types of branched cyclode xtrins, including maltosyl beta -cyclodextrin (maltosyl-beta -CyD). For eac h novel cyclodextrin carboxylic acid derivative synthesized, the hydroxymet hyl group of the terminal glucose residue in the branched part of the molec ule was regiospecifically oxidized to a carboxyl group to give the correspo nding uronic acid. In addition, the physicochemical properties of cyclomalt oheptaosyl-(6 --> 1)-alpha -D-glucopyranosyl-(4 --> 1)-alpha -D-glucopyrano siduronic acid (GUG-beta -CyD) (1) and its sodium salt were studied more ex tensively, as these compounds are most likely to have a practical applicati on. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.