Indole alkaloids from Ervatamia chinensis

Four vobasinyl-ibogan type bisindole alkaloids, ervachinines A-D (1-4), along with 12 known terpenoid indole alkaloids, were isolated from the whole plant of Ervatamia chinensis. Their structures were elucidated by analysis of spectroscopic data, including 1D and 2D NMR, and the absolute configurations of 1-4 were determined by CD exciton chirality method. All of the compounds were evaluated for in vitro cytotoxicity against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480. Bisindole alkaloids 1-6 exhibited inhibitory effects, with IC(50) values comparable to those of cisplatin.