Preparation of D-glucosamine oligosaccharides by the enzymatic hydrolysis of chitosan.

In an earlier study,1} D-glucosamine oligosaccharides were prepared, using ion-exchange chromatography, from a partial hydrolyzate ofchitosan with HC1.The oligosaccharides from (GlcN)2* to (GlcN)5 were obtained by this procedure with lower yield as their molecular weight increased, but a large amount of D-glucosamine was also produced in the acid hydrolyzate.Wehave reported2) that the chitosanase from Bacillus sp.No. 7-M produced dglucosamine oligosaccharides of high molecular weight in the degradation of chitosan and a slight amount of dglucosamine is detected only after prolonged incubation.D-Glucosamine oligosaccharides of high molecular weight have antifungal activity.3*In this paper, we describe how D-glucosamine oligosaccharides can be prepared with a high yield by the enzymatic hydrolysis of chitosan.Chitosan (the degree of deacetylation, 99%) was the