Antioxidative activities of water-soluble disaccharide chitosan derivatives.

Water-soluble chitosan derivatives, having various degrees of substitution with disaccharide (DS 20–30%, 40–50%, 60–70%), were prepared by reductive alkylation of a-chitosan with lactose, maltose or cellobiose. Antioxidative activities were determined in the present study, including radical scavenging effect for a,a-diphenyl-b-picryl-hydrazyl (DPPH) radicals, superoxide anion radicals, hydrogen peroxide and copper ion chelating ability of these chitosan derivatives.