A new triterpene and anti-hepatitis B virus active compounds from Alisma orientalis

A new triterpencid named alisol 0 (1) was isolated from the rhizomes of Alisma orientalis, together with six known compounds: alisol A 24-acetate (2), 25-anhydroalisol A (3),13 beta,17 beta-epoxyalisol A (4), alisol B 23-acetate (5), alisol F (6), and alisol F 24-acetate (7). Based on 1D and 2D-NMR data (HMQC, HMBC, COSY, ROESY), the structure of the new compound was deduced to be 11-dehydroxy-12-dehydroalisol F-24-acetate (1). Compounds 2-7 exhibited inhibitory activity in vitro on hepatitis B virus (HBV) surface antigen (HBsAg) secretion of the Hep G2.2.15 cell line with IC50 values of 2.3,11.0,15.4,14.3, 0.6 and 7.7 mu M, and on HBV e antigen (HBeAg) secretion with IC50 values of 498.1, 17.6, 41.0,19.9, 8.5 and 5.1 mu M, respectively.