Heparan chemical structure

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. 

Heparin/heparan, hyaluronan, and chondroitin are three prevalent glycosaminoglycans. Vertebrates use glycosaminoglycans in structural, recognition, adhesion, and signaling roles. Chemical synthesis of naturally occurring polysaccharides is considered to be impractical. Most polysaccharides, especially those from bacteria origins, are obtained by purification from natural sources or from cell culture, enzymatic approaches have been increasingly applied to obtain some structures. 

---