The whole plant of Ervatamia coronaria var. plena obtained from Thailand has afforded a new indole alkaloid 19S-heyneanine hydroxyindolenine whose structure was deduced through interpretation of spectral data. Nine known alkaloids, coronaridine, coronaridine hydroxyindolenine, voacangine, voacangine hydroxyindolenine, heyneanine, voacristine, 3-oxo-coronaridine, 3-oxo-voacangine,and voacristine hydroxyindolenine, and six common triterpenoids were also isolated. Coronaridine was the principal cytotoxic alkaloid obtained.