Anti-hepatitis B virus lignans from the root of Streblus asper

The structures and absolute stereochemistries of four neolignans (1-4) isolated from the root of Streblus asper have been determined by detailed spectroscopic analyses. The anti-HBV activity assay of the isolated lignans indicated that (7′R,8′S,7″R,8″S)-erythro-strebluslignanol G (2), magnolol (5), isomagnolol (6) and isolariciresinol (13) were the most active against hepatitis B virus.