Cedronin was isolated from Simaba cedron Planchon (Simaroubaceae), a species popularly believed in South America to have antimalarial properties. It was examined for in vitro and in vivo antimalarial activities and for cytotoxicity against KB cells. Experimental results showed that cedronin was
Cymosanine (1) and three further known quassinoids, cedronin (2), chaparrinone (3), and simarolide (4), were isolated from the root bark of Simaba subcymosa. The structures were established by spectroscopic data, mainly 1D, 2D NMR and mass spectra.