Anti-hepatitis B virus constituents from the stem bark of Streblus asper.

Abstract Seven compounds, (7′ S ,8′ S )- trans -streblusol A, (7′ R ,8′ S )- erythro- streblusol B, (7′ S ,8′ S )- threo- streblusol B, 8′ R -streblusol C, streblusquinone, (8 R ,8′ R )-streblusol D, and streblusol E, along with 15 known compounds ( 8 – 22 ) were isolated from the n -butanol-soluble part of the MeOH extract of stem bark of Streblus asper . Their structures were elucidated through application of extensive spectroscopic methods, including ESI-MS and 2D NMR spectroscopy (HMQC and HMBC). The stereochemistry at the chiral centers was determined using CD spectra, as well as analyses of coupling constants and optical rotation data. The isolated lignans and allylbenzene derivatives were evaluated for their anti-HBV activities in vitro using the HBV transfected Hep G2.2.15 cell line. The most active compounds, magnolol and 9- β -xylopyranosyl-isolariciresinol, exhibited significant anti-HBV activities with IC 50 values of 2.03 and 6.58 μM for secretion of HBsAg, with no cytotoxicity, and of 3.76 and 24.86 μM for secretion of HBeAg, with no cytotoxicity.