Heparin sulfate, chemical structure

The chemical structure was deduced to involve mainly (1 —> 4)-linked 2-deoxy-2-(sulfoamino)-a-D-glucose 6-sulfate and (1 —> 4)-linked 2-sulfated a-L-idopyranosyluronic acid residues. The X-ray patterns from sodium salts of hog-mucosal heparin index with a triclinic unit-cell, having a = 1.30 nm, b = 1.02 nm, c = 1.65 nm, a = 104°, /3 = 96°, and y = 116°, containing one chain. The macromo-lecular heparin from rat skin, at 84% relative humidity (r.h.), gives a pattern consistent with a highly oriented version of the hog-mucosal heparin. On lowering the r.h. to 76%, the repeat distance along the fiber axis increases to 1.73 nm, with meridional reflections on the even layer-lines. 

In order to shed more light on the Interaction of water with these mucopolysaccharides, we employ the DSC method to follow the melting behavior of aqueous solutions of the polysaccharides cooled to -50 C. The polymers chosen here are chondroitin sulfate A (Chn S-A), chondroitin sulfate C (Chn S-C), chondroitin (Chn), heparin (Hpn), and hyaluronic acid (HyA). Their chemical structures are shown in Figure 1. The DSC curves allow us to determine the amount of the non-freezing water In highly concentrated solutions, since any endothermic peak Is not observed for such solutions over a wide temperature range (17. 18). This paper will also describe the presence of more than one endothermic peak In the DSC curves for solutions of relatively low polymer concentrations. 

It is known that sulfated polysaccharides, including natural and synthesized ones, had great blood-compatibility or even anticoagulant activity [34]. After sulfation of sodium alginate, its derivative contains both sulfate and carboxyl groups, whose chemical structure is analogous to the natural blood anticoagulant heparin. Fan et al. 

To prepare A-propanoyl-, A-hexanoyl-, and A,0-quatemary substituted chitosan sulfate with the similar structure of heparin, the chemical modification of chitosan sulfate was carried out by Huang et al. (2003). The propanoyl (SCOS II) and hexanoyl (SCOS III) groups increased the thromboplastin time (APTT) activity, and the propanoyl groups also increased the thrombin time (TT) anticoagulant activity slightly, while the A,0-quaternary chitosan sulfate (SCOS IV) showed only a slight TT coagulant activity. 

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