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.