ANTIMALARIAL ACTIVITY OF CEDRONIN

Cedronin was isolated from Simaba cedron Planchon (Simaroubaceae), a s pecies popularly believed in South America to have antimalarial proper ties. It was examined for in vitro and in vivo antimalarial activities and for cytotoxicity against KB cells. Experimental results showed th at cedronin was active against chloroquine-sensitive and resistant str ain, with an IC50 of 0.25 mu g/ml (0.65 mu mol/ml). It was also found to be active in vivo against Plasmodium vinkei with an IC50 of 1.8 mg/ kg (4.7 nM/kg) in the classic 4-day test. Cedronin belongs to the smal l group of quassinoids with a C-19 basic skeleton and shows a rather l ow cytotoxicity against KB cells (IC50 = 4 mu g/ml, 10.4 mu M) as comp ared with C-20 biologically active quassinoids; however its toxic/ther apeutic ratio (10/1.8) remains lower than chloroquine (10/0.5).