Three New Antiviral Triterpenes from Aster tataricus

Three new shionane-type triterpenes, shion-22-methoxy-20(21)-en-3-one (1), shion-22(30)-en-3,21-dione (2), shion-22-methoxy-20(21)-en-3 beta-ol (3), were isolated from the rhizomes of Aster tataricus. Their structures have been determined on the basis of MS, 1R, 1D and 2D NMR spectral evidences. Compounds 1 and 2 show inhibitory activities on HBsAg with IC50 values of 0.89 and 4.49 mu g mL(-1), respectively, 1 shows inhibitory activity on HBeAg with an IC50 value of 0.83 mu g mL(-1), and 2 shows inhibitory activity on HA with an IC50 value of 11.18 mu g mL(-1).