Characterization and biological evaluation of six new dimeric lignans with an unusual α,ß-unsaturated ketone motif from Zanthoxylum simulans.

Investigation of the bark of Zanthoxylum simulans afforded six new dimeric lignans zanthpodocarpins C-H (1-6) bearing an unusual α,ß-unsaturated ketone group. The new structures of 1-6 were determined by using detailed spectroscopic analysis. All of the isolated compounds were examined for their inhibitory effects against rat joint synovial cell and splenocyte proliferation. Compounds 1-6 showed potent anti-inflammatory activities with IC50 values ranging from 18.6 to 36.1µM, and 13.8 to 74.3µM.