Influence of functional groups on the in vitro anticoagulant activity of chitosan sulfate

A new method for the chemical modification of chitosan sulfate was used to prepare N-propanoyl-, N-hexanoyl- and NO-quaternary substituted chitosan sulfate. Structural analysis by elemental analysis, FTIR, C-13 NMR, and H-1 NMR spectroscopy, and gel-permeation chromatography showed that these methods could conveniently be used for the introduction of functional groups. The influences of the acyl or quaternary groups on the anticoagulant activity of the polysaccharides were studied with respect to activated partial thromboplastin time (APTT) thrombin time (IT), and prothrombin time (PT). The propanoyl and hexanoyl groups increased the APTT activity, and the propanoyl groups also increased the TT anticoagulant activity slightly, while the NO-quaternary chitosan sulfate showed only a slight TT coagulant activity. (C) 2003 Elsevier Science Ltd. All rights reserved.