Preparation, by chemical degradation of hyaluronic acid, of a series of even- and odd-numbered oligosaccharides having a 2-acetamido-2-deoxy- d-glucose and a d-glucuronic acid residue, respectively, at the reducing end

Abstract

A series of even-numbered hyaluronate oligosaccharides (di- to octadeca-) having a 2-acetamido-2-deoxy- d-glucose residue at the reducing end was prepared by treatment of sodium hyaluronate with dimethyl sulfoxide containing 10% of 0.1 m hydrochloric acid for 16 h at 95°. The mixture of the even-numbered oligosaccharides obtained was converted with 0.15 m sodium carbonate for 6 h at 40° into a series of odd-numbered oligosaccharides (mono- to pentadeca-) having a d-glucuronic acid residue at the reducing end. Reaction of the hyaluronate tetrasaccharide with saturated calcium hydroxide gave β- d-Glc pA-(1→3)-β- d-Glc pNAc-(1→3)- d- arabo-trihydroxyglutaric acid besides the expected trisaccharide.