Cucumol A: a cytotoxic triterpenoid from Cucumis melo seeds

ABSTRACT Phytochemical investigation of the MeOH extract of Cucumis melo L. var. reticulates, Cucurbitaceae, seeds led to the isolation of a new triterpenoid: cucumol A (27-hydroxy taraxerol-3β-ol), along with three known compounds: α-spinasterol and D:B-friedoolean-5-ene-3-β-ol. Their structures were established by extensive 1D (1H, 13C, and DEPT) and 2D (1H–1H COSY, HMQC, and HMBC) NMR, as well as IR and HRESIMS spectral analyses. Compound 3 displayed cytotoxic activity against L5178Y and Hela cancer cell lines with ED50 of 1.30 and 5.40 µg/ml, respectively compared to paclitaxel (0.07 and 0.92 µg/ml, respectively).