Selective acetolysis of primary benzyl ethers

Hot-water extraction of defatted skin of the fish Labeo rohita yielded a viscous, glycoprotein solution. This was extensively digested with pronase, and then treated with trichloroacetic acid to remove the proteins and nucleic acids. On precipitation with ethanol, the solution furnished a mixture of several glycosaminoglycans which was fractionated by complexing with cetylpyridinium chloride and alkaline copper solution to yield three pure fractions. From analyses, specific rotation values, i.r. data, and enzymic studies, the three fractions were fully characterized to be dermatan sulfate, chondroitin 4-sulfate, and hyaluronic acid. The viscosity-average molecular weight of dermatan sulfate was found to be 2.3 x 10⁴, and that of hyaluronic acid, 1.78 x 10⁵.