The dichloromethane extract of the freeze-dried seeds of Moringa oleifera Lam afforded 4-(4'-O-acetyl-α-L-rhamnosyloxy) benzyl isothiocyanate (1), 4-(α-L-rhamnosyloxy) benzyl isothiocyanate (2), squalene (3) and sitosterol (4). The dichloromethane extract of the air-dried leaves of M. oleifera afforded polyprenol (5), phytyl fatty acid ester (6) and lutein (7). The structures of 1 and 2 were elucidated by extensive 1D and 2D NMR spectroscopy, while those of 3-7 were identified by comparison of their 13C NMR data with those reported in the literature.
Isothiocyanates 1 and 2 were evaluated for cytotoxicity against the human cancer cell lines, non-small cell lung adenocarcinoma (A549) and colon carcinoma (HCT 116), and the non-cancer cell line Chinese hamster ovary cells (AA8) using the MTT cytotoxicity assay. Compounds 1 and 2 were cytotoxic against A549 with IC50 values of 10 and 12 µM, respectively, while the positive control, Doxorubicin gave an IC50 value of 4 µM. Isothiocyanates 1 and 2 were also cytotoxic against HCT 116 with IC50 values of 12 and 11 µM, respectively while Doxorubicin exhibited an IC50 value of 3 µM. Compounds 1, 2 and Doxorubicin were also cytotoxic against AA8 with IC50 values of 22, 15 and 4 µM, respectively.*Corresponding author