Gnetum gnemon L. (Gnetaceae) is used traditionally for treating malaria related fever by indigenous people of North East India. In our preliminary study, the ethanol extract of G. gnemon leaves showed promising antiplamodial activity against Plasmodium falciparum chloroquine sensitive (3D7) strain in vitro with an IC50 value of 29.4 μg/mL. Therefore, it was further investigated, and by following a bioassay guided approach, 2,3-dihydroxypropyl icosanoate (1), oleic acid (2) and ursolic acid (3) were isolated for the first time from this plant. Compound 3 showed highest antiplasmodial activity with IC50 values of 4.0 and 6.0 μg/mL against chloroquine sensitive (3D7) and resistant (Dd2) strains of P. falciparum, respectively. The antiplasmodial activity of 1 (IC50 9.5 and 11.4 μg/mL) and 2 (IC50 17.6 and 21.1 μg/mL) was moderate. The isolated constituents showed low cytotoxicity against rat skeletal muscle (L6) and human cervical cancer (HeLa) cells. This is the first report on the antimalarial potential of G. gnemon and the isolated compounds may be responsible for its activity. The findings of the study are in line with the ethnopharmacological claim and can be possible leads for future studies.
