ANTIVIRAL ACTIVITY AGAINST HSV-2 OF SULFATED POLYSACCHARIDE FROM CYATHULA OFFICINALIS KUAN IN VITRO

The sulfated derivative of RCP, a kind of polysaccharide extracted from Cyathula officinalis Kuan was prepared by chlorosulfur acid-pyridine method. In IR analysis, the resulting derivative (S-RCP) showed the characteristic adsorption of sulfo-group at 1 250 cm -1 and 810 cm -1, indicating the hydroxy groups of RCP, was partially esterified by chlorosulfur acid. The sulfur content of S-RCP was 8.27% and the average degree of substitution D s was 0.569. Cytotoxicity and antiviral activity of both RCP and S-RCP were studied in Vero-cell culture system. RCP with concentrations below 6.0 mg/mL and S-RCP below 4.0 mg/mL showed no cytotoxicity to Vero cell. S-RCP could inhibit the cytopathic effect caused by herpes simplex virus type 2 (HSV-2) at concentrations of 0.25～4.0 mg/mL, while RCP itself showed no antiviral activity in the same condition. Further studies proved that S-RCP with concentrations of 2.0 mg/mL and 4.0 mg/mL expressed equal antiviral activity with the commonly used antiviral drug ACV of 0.5 mg/mL. Fig 1, Tab 8, Ref 20