Cucumol B, a new triterpene benzoate from Cucumis melo seeds with cytotoxic effect toward ovarian and human breast adenocarcinoma.

Phytochemical investigation of the methanolic extract of Cucumis melo L. (Cucurbitaceae) seeds furnished a new triterpene benzoate derivative: cucumol B (1) and four known flavonoids: quercetin-3-O-ß-D-glucopyranosyl-(1→6)-α-L-rhamnopyranoside (2), quercetin-3-O-ß-D-glucopyranoside (3), quercetin (4), and luteolin (5). Their structures were identified by UV, IR, 1D (13C and 1H), 2D (HSQC, 1H-1H COSY, HMBC, and NOESY) NMR, and HRESIMS spectral as well as comparing with literature data. Compound 1 has been assessed for the in vitro cytotoxic effect against SKOV-3, MCF-7, and HCT-116 cell lines. It had selective and potent effect toward SKOV-3 and MCF-7 cell lines with IC50s 2.05 and 0.41 µM, respectively, in comparison to doxorubicin (IC50s 0.32 and 0.05 µM). However, it showed moderate activity toward HCT-116 cell line with IC50 8.27 µM.

Garcixanthone A, a new cytotoxic xanthone from the pericarps of Garcinia mangostana.

A new prenylated xanthone, garcixanthone A (5), together with eight known compounds, mangostanaxanthones I (1) and II (2), garcinone E (3), ß-mangostin (4), 8-hydroxycudraxanthone G (6), garcinone C (7), cudraxanthone G (8), and (-)-epicatechin (9) were isolated from the EtOAc-soluble fraction of the air-dried pericarps of Garcinia mangostana (family Clusiaceae). Their structures were verified on the basis of spectroscopic data interpretation as well as comparison with the literature. The cytotoxic and antimicrobial activities of the new compound were assessed using sulforhodamine B (SRB) and agar disk diffusion assays, respectively. Compound 5 showed significant cytotoxic potential against epithelial lung carcinoma (A549) and breast carcinoma (MCF7) cell lines with IC50s 3.0 and 4.2 µM, respectively, compared to doxorubicin (0.74 and 0.41 µM, respectively).