3,6-Anhydroglucosaminyl formation in mucopolysaccharides

Treatment of keratosulfates with alkali leads to the formation of 3,6-anhydroglucosaminyl groups in high yield. A similar reaction takes place with heparin and heparitin sulfate, though to a lesser extent. The anhydrosugar was isolated and compared with synthetic 3,6-anhydroglucosamine. The isolated compounds were identical in ion exchange chromatography in the amino acid analyzer and on Dowex 50 H(+) eluted with dilute HCl. The spectra of the isolated and synthesized anhydrosugar were identical in infrared and nuclear magnetic resonance. Derivatized compounds were identical in gas-liquid chromatography and mass spectroscopy. The peracetylated compound isolated from keratosulfate gave the nuclear magnetic reasonance and fragmentation pattern of the postulated compound. The reaction is expected to be useful in structural studies of hexosamine-containing polymers.