Preparation and anticoagulant activity of N-succinyl chitosan sulfates

In order to develop a promising substitute for heparin, N-succinyl chitosan (NSC) was chemically modified by sulfating agent N(SO3Na)3, which were synthesized with sodium bisulfite and sodium nitrite in aqueous solution. The N-succinyl chitosan sulfates (NSCS) products were characterized by infrared spectroscopy (FT-IR) and 13C NMR. The degree of substitution (DS) of NSCS depended on the ratio of sulfating agent to N-succinyl chitosan, reaction temperature, reaction time and pH of sulfation agent. N-succinyl chitosan sulfates with DS of 1.97 were obtained under optimal conditions. The in vitro coagulation assay of NSCS was determined by activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) assays. The results showed that NSCS obviously prolonged APTT. The anticoagulant activity strongly depended on DS, molecular weight (Mw) and concentration of NSCS. The anticoagulant activity of NSCS promoted with the increase of DS and concentration, and NSCS exhibited the best anticoagulant activity with the Mw of 1.37 × 104.