Antiplasmodial activity of cucurbitacin glycosides from Datisca glomerata (C. Presl) Baill.

The traditionally used antimalarial plant, Datisca glomerata (C. Presl) Baill, was subjected to antiplasmodial assay guided fractionation. This led to the isolation of seven cucurbitacin glycosides, datiscosides I-O, along with two known compounds, datiscoside and datiscoside B, from the aerial parts of D. glomerata. Their structures and relative stereochemistry were determined on the basis of mass spectrometry, 1D and 2D NMR spectroscopic data. Antiplasmodial IC(50) values were determined for all isolated compounds against a chloroquine sensitive strain of Plasmodium falciparum (D10), which were also evaluated in vitro for their antileishmanial activity against Leishmania tarentolae. Cytotoxicity was evaluated against rat skeletal muscle cells (L6) and Chinese ovarian hamster cells (CHO). The antiplasmodial activity of the compounds was moderate and ranged from 7.7 to 33.3 μM. None of the compounds showed appreciable antileishmanial activity. The compounds displayed cytotoxicity against L6 but not CHO mammalian cells.