Four New Styryllactones form Goniothalamus leiocarpus

Four new styryllactones, leiocarpin A (1), 7-epi-goniodiol (2), leiocarpin B (3) and leiocarpin C (4), respectively, were isolated from the stem bark of Goniothalamus leiocarpus. Their structures were elucidated by means of spectral method. The relative configurations of 1, 2 and 3 were determined by X-Ray crystallographic analysis. Compounds 2 and 3 possess antitumor activities.