9alpha,13alpha-Dihydroxylisopropylidenylisatisine A (1), which was derived from isatisine A (2) and possessed an unprecedented fused pentacyclic skeleton, was isolated from the leaves of Isatis indigotica Fort. The structure and relative configuration were elucidated on the basis of extensive NMR analyses and finally determined by single-crystal X-ray diffraction. Compound 1 showed moderate anti-HIV-1 activity with EC50 = 37.8 microM and SI = 7.98.

A new triterpenoid named alisol O ( 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 IC (50) values of 2.3, 11.0, 15.4, 14.3, 0.6 and 7.7 microM, and on HBV e antigen (HBeAg) secretion with IC (50) values of 498.1, 17.6, 41.0, 19.9, 8.5 and 5.1 microM, respectively.

Five new icetexane diterpenoids, namely, perovskatones B-D (1, 3, 4), 1α-hydroxybrussonol (2), and 1α-hydroxypisiferanol (5), were isolated from Perovskia atriplicifolia, together with a new natural product (6) and two known compounds, przewalskin E (7) and brussonol (8). The structures of the new compounds were elucidated by detailed analyses of their MS, IR, 1D, and 2D NMR data. Compounds 1-8 were assayed for their inhibitory hepatitis B virus activities in the HepG 2.2.15 cell line. The results suggested that compounds 1 and 2 possessed noticeable anti-hepatitis B virus activity in vitro, suppressing the replication of hepatitis B virus DNA with selectivity index values of 154.3 and 137.7, respectively.