The in vitro antiplasmodial activities of 14 plant species traditionally us
ed in Central America for the treatment of malaria or fever were evaluated.
Lipophilic extracts of Piper hispidum, Siparuna andina, S. pauciflora, S.
tonduziana, and Xylopia cf. frutescens, proved to be active against both a
chloroquine-sensitive and a resistant strain of Plasmodium falciparum. IC50
values ranged between 3.0 mu g/ml and 21.9 mu g/ml; however, moderate cyto
toxicity of active extracts was observed. Bioactivity-guided fractionation
of Piper hispidum yielded 2',4,6'-trihydroxy-4'-methoxydihydrochalcone (ase
bogenin) as an active compound.