An improved method for the preparation of chondroitin by solvolytic desulfation of chondroitin sulfates

By heating the pyridinium salts of chondroitin 4- and 6-sulfates in dimethyl sulfoxide containing 10% of water or methanol at 80 degrees C for 1--5 h, several chondroitin preparations with sulfur contents of 0.02--1.05% were prepared in 83--96% yields, respectively. Chemical properties of the preparations, such as degrees of desulfation and of depolymerization, were compared with those of the products obtained by the previously described methods.