Progress in Modifications of Polysaccharide and Its Anticoagulant Activity

Polysaccharide is an important biological macromolecule in many organisms,and it is cheap and easy to get.Some natural polysaccharides have potent biological and pharmacological activities including antivirus,antitumor,anticoagulant,immunomodulating activities and so on.But most polysaccharides possess pharmacological activities only after specifical structural modification.Many sulfated polysaccharidesdisplay an anticoagulant function,which is similar to that of heparin,and the polysaccharidederivativesdo not have antiplatelet activity,and thus it can avoid side effects caused by heparin.The anticoagulant activity is mainly affected by sulfonic acid and carboxylic group in molecular side chains of polysaccharides.In this review,the methods of structural modification such as chemical and biological methods in polysaccharides aredescribed with emphasis on the sulfation and oxidation in polysaccharides and their impacts on biological activity of polysacchrides.