The isolation of secondary metabolites and in vitro potent anti-cancer activity of clerodermic acid from Enicosanthum membranifolium.

Four compounds were isolated from Enicosanthum membranifolium. The structures of the compounds were confirmed by spectroscopic data. Their structures were determined as N-trans-feruloyltyramine, R-(-)-mellein, clerodermic acid, and salicifoline chloride as a quaternary alkaloid compound. The structures of R-(-)-mellein and salicifoline chloride were confirmed by using X-ray diffraction. Clerodermic acid was shown to induce potent apoptosis against human leukemia HL60 cells.