Tasmanine, a New Indole Alkaloid from Aristotelia peduncularis (LABILL.) HOOK. F. The new indole alkaloid tasmanine (3) was isolated from Aristotelia peduncularis. Its relative configuration was elucidated on the basis of spectroscopic data (mainly NMR. spectra). It is closely related to the other known alkaloids from Aristotelia with double substitution at the indole nucleus. A biosynthetic pathway to these related natural compounds is proposed; also a biogenetic numbering system is suggested.