[Synthesis of Achyranthes bidentata polysaccharide sulfate and its antivirus activity].

Sulfation of Achyranthes bidentata polysaccharide (Abps) with sulfuric acid or sulfur trioxide-pyridine or chlorosulfonic acid-pyridine was studied. A homogeneous sulfation method with good yield of 82.11% was obtained, using chlorosulfonic acid in an excess of pyridine. Sulfated Achyranthes bidentata polysaccharide was obtained as an amorphous sodium salt easily soluble in water. The UV and IR spectrum of Abps sulfate showed absorptions at 208, 268, 286 nm and 1232, 823.6 cm-1 respectively. The sulfur content of the products was found to be 20-22%. The degree of substitution varied from 2.8 to 3.2. It showed that the hydroxy group of Abps was almost completely esterified by chlorosulfonic acid. The Abps sulfate was shown to have high activity as anti-HBsAg and HBeAg. It is also effective on simple herpes virus type-I.