In vitro antimalarial activity of prenylated flavonoids from Erythrina fusca.

Ethyl acetate (EtOAc) extract from the stem bark of Erythrina fusca showed a antimalarial activity against the multi-drug-resistant strain (K1) of Plasmodium falciparum, and six flavonoids, lupinifolin (1), citflavanone (2), erythrisenegalone (3), lonchocarpol A (4), liquiritigenin (5), and 8-prenyldaidzein (6), were isolated from the extract. Diprenylated flavanone 4 showed a notable antimalarial activity (IC(50); 1.6 microg/mL); however 1 and 3 did not show the activity, even though these compounds possessed prenylated substitution.