Two New Indole Alkaloids from the Bark of Anthocephalus chinensis

Two new indole alkaloids, cadambinic acid (1) and isonauclefidine (2), were isolated from the bark of Anthocephalus chinensis. The structures were identified by spectroscopic methods, and the compounds were tested for their biological activities. Both compounds showed weak cytotoxicities against A549, BGC-823, and HeLa cells in biological assays.