Enzymic Degradation of Hydroxyethyl Starch. Part I. Influence of the Distribution of Hydroxyethyl Groups on the Enzymic Degradation of Hydroxyethyl Starch

Abstract

Abstract The action of pig pancreas α‐amylase on various samples of hydroxyethyl starches (HES) has been studied. It has been shown that the hydrolysis rates of both 2‐hydroxyethyl starches (2‐HES) and 6‐hydroxyethyl starches (6‐HES) decreased as M. S. or D. S. increased, i. e. the more the unsubstituted anhydroglucose residues the specimen contained, the more rapidly the degradation took place. Further evidences have been obtained indicating that 2‐O‐hydroxyethylanhydroglucose residues played a more significant role on the resistance to α‐amylase action than 6‐O‐hydroxyethyl‐anhydroglucose residues. Thus, each sample of 2‐HES has been more resistant to α‐amylolytic attack than the corresponding specimen of 6‐HES, regardless of the same content of unsubstituted anhydroglucose residues.