Chemical Derivatization of Sulfated Glycosaminoglycans

Sulfated glycosaminoglycans (GAGs) are a family of complex polysaccharides ubiquitously distributed in extracellular matrices and at cell surfaces and playing key roles in a myriad of biological processes. Their structures are based on disaccharide building blocks, usually containing an amino sugar and an uronic acid, decorated with one or more sulfate groups. Many efforts to gain access to a large number of sulfated GAG polysaccharides with potential tailored biomedical applications, usually based on suitable chemical (and chemo-enzymatic) derivatization procedures that modified the native polysaccharide structures, have been reported in the last two decades. In this review we survey such reactions on the basis of (i) the sulfated GAG substrate [(fucosylated) chondroitin sulfate, dermatan sulfate, heparin, and heparan sulfate], and (ii) the sort of structural modification (sulfation pattern modification, oxidation, carboxy group derivatization, N- and O-acylation, reducing-end functionalization).