Heparan sulfate hexosamine

A glycosaminoglycan is a heteropolysaccharide consisting of repeating disaccharide sequences, where each disaccharide contains a hexosamine and a hexuronic acid chondroitin sulfate, dermatan sulfate, heparin, and heparan sulfate). However, in keratan sulfate, the hexuronic acid moiety is replaced by a hexose [8, 28]. These... 

Values of optical rotations from [a]n +38° to + 78 , and various ratios of sulfate to hexosamine content have been reported these ratios, however, are all in the vicinity of i. Various contents of sulfamate and JV-acetyl groups have also been observed, and it has become evident that one is dealing more with a family of substances, possessing varying degrees of N- and 0-s ilfation, than with a chemical entity. Since our knowledge of the chemical structure of the polysaccharide chain is still scant, it has not been possible to ascertain definitely the chemical identity between the various low sulfated heparans. 

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