A new steroid glycoside from Begonia sp.: cytotoxic activity and docking studies.

Chemical investigation on the ethyl acetate extract of the aerial parts of Begonia sp. afforded a new steroid glycoside, 9(11)α,16(17)α-dioxirane-20,25-dihydroxy-ß-sitosterol-3-O-ß-glucopyranoside (1) along with a known steroidal glycoside, ß-sitosterol-3-O-ß-D-glucopyranoside (2). The Chemical structures were elucidated by 1D and 2D NMR and mass spectroscopic analysis. Cytotoxicity against four different cancer cell lines (HeLa, T47D, WiDr and Vero) was assessed. Compound 1 was more potent and selective against breast cancer cell line (T47D) than other cell lines with an IC50 value of 0.16 µg/mL. Further docking study of 1 exhibited the preference of molecule to bind in the epidermal growth factor receptor tyrosine kinase (EGFR-TK) binding pockets with docking scores of -97.8800 (PLANTS) and -3.56 kcal/mol (AutoDock 4.2.6).

4-Benzyloxylonchocarpin and Muracatanes A-C from Ranunculus muricatus L. and Their Biological Effects.

Ranunculus muricatus L. is a spiny fruit buttercup that is used in various traditional medicinal systems. In the current investigation of R. muricatus, the new chalcone 4-benzyloxylonchocarpin (1), the new anthraquinone muracatanes A (2), the new-to-nature anthraquinone muracatanes B (3), and the new naphthalene analog muracatanes C (4) were isolated, in addition to the three previously reported compounds, 4-methoxylonchocarpin (5), ß-sitosterol (6), and ß-sitosterol ß-D-glucopyranoside (7). Their structures were elucidated using 1D (1H and 13C) and 2D (COSY, HSQC, and HMBC) NMR spectroscopy and HR-ESI-MS. Chalcone 1 showed potent acetylcholinesterase inhibitory effects with Ki of 5.39 µM and Ki' of 3.54 µM, but none of the isolated compounds showed inhibitory activity towards butyrylcholinesterase. Anthraquinone 3 illustrated α-glucosidase inhibitory effects with IC50-values of 164.46 ± 83.04 µM. Compound 5 displayed moderate cytotoxic activity towards ovarian carcinoma (A2780, IC50 = 25.4 µM), colorectal adenocarcinoma (HT29, IC50 = 20.2 µM), breast cancer (MCF7, IC50 = 23.7 µM), and thyroid carcinoma (SW1736, IC50 = 26.2 µM) while it was inactive towards pharynx carcinoma (FaDu: IC50 > 30 µM).