Two new secoiridoids and other anti-hepatitis B virus active constituents from Swertia patens.

Two new secoiridoids, swerpatic acid (1) with an unusual C8 skeleton and swerpalactone (2), were isolated along with ten known compounds (3-12) from the whole plants of Swertia patens. Their structures were elucidated by comprehensive spectroscopic analyses. Eight compounds were evaluated for their anti-hepatitis B virus (HBV) activities on Hep G 2.2.15 cell line in vitro. Compounds 4 and 10 showed moderate inhibitory activities on the secretion of HBsAg with IC50 values of 1.96 and 0.50 mM.