Chemical investigation of the leaves of Rauwolfia sumatrana Jack. collected in Thailand resulted in the isolation of three new indole alkaloids, 11-methoxystrictamine (1), rausutrine (4) and rausutranine (7), along with ten known bases, harman, tetraphyllicine, flexicorine, lanceomigine, perakine, β-carboline, peraksine, 10-hydroxystrictamine, cabufiline and compactinervine. Rausutrine (4) and rausutranine (7) are novel bis-indole alkaloids composed of an akuammilane unit and a vincorane unit, the latter of which has a unique iminoquinone function. © 1994, The Pharmaceutical Society of Japan. All rights reserved.