Résumé
A new quassinoid Picrasin K 1 was isolated from a decoction made of Quassia amara leaves, traditionally used in French Guyana to treat malaria. The structure and relative stereochemistry of 1 was determined through extensive NMR analysis. Picrasin K showed a low activity against Plasmodium falciparum in vitro (IC50 = 8 μM), and a similar low activity on human cancerous cells line (IC50 = 7 μM on MCF-7 cells line).