Antimalarial agents from plants - II. Decursivine, a new antimalarial indole alkaloid from Rhaphidophora decursiva

Abstract

Antimalarial bioassay-directed fractionation led to the isolation of a new active indole alkaloid, decursivine (1), from the leaves and stems of Rhaphidophora decursiva Schott (Araceae). In addition, a leaf sample yielded the structurally-related compound serotobenine (2), previously reported from a taxonomically unrelated family, which was not active against Plasmodium falciparum. The structure of 1 was elucidated by spectroscopic means, and its antimalarial activity was observed with IC50 values of 3.93 and 4.41 mug/ml against the D6 and W2 clones of Plasmodium falciparum, respectively.