Obtusifoliol

27474490

From the aerial parts of Euphorbia sogdiana Popov, obtusifoliol (1) and two related steroids (2-3) have been isolated and characterized along with a known cycloartane derivative (4). The chemical structure of the obtusifoliol-related compounds, obtained by 1D and 2D NMR, and MS measurements, have been determined as: 3β,7α-dihydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-11-one (2) and 3β-hydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-1-one (3). Compound 2 has been previously isolated from Euphorbia chamaesyce while compound 3 was never reported before. The isolated compounds 1-4 were subjected to cytotoxic tests on the breast cancer cells, MCF-7 and MDA-MB231. Further pharmacological tests on the more active compounds 2 and 3 indicated their action to be related to cell growth inhibitory activity and apoptotic effects on the tested cells.

4α-Methyl sterols; Anticancer; Apoptosis; Breast cancer; Euphorbia sogdiana; Obtusifoliol analogues.

Obtusifoliol related steroids from Euphorbia sogdiana with cell growth inhibitory activity and apoptotic effects on breast cancer cells (MCF-7 and MDA-MB231)

Mahmoud Aghaei 1, Zeinab Yazdiniapour 2, Mustafa Ghanadian 3, Behzad Zolfaghari 2, Virginia Lanzotti 4, Vahid Mirsafaee 2

2016 Nov;

27313059

Rapidly multiplying cancer cells synthesize greater amounts of cholesterol to build their membranes. Cholesterol-lowering drugs (statins) are currently in clinical trials for anticancer chemotherapy. However, given at higher doses, statins cause serious side effects by inhibiting the formation of other biologically important molecules derived from mevalonate. Sterol 14α-demethylase (CYP51), which acts 10 steps downstream, is potentially a more specific drug target because this portion of the pathway is fully committed to cholesterol production. However, screening a variety of commercial and experimental inhibitors of microbial CYP51 orthologs revealed that most of them (including all clinical antifungals) weakly inhibit human CYP51 activity, even if they display high apparent spectral binding affinity. Only one relatively potent compound, (R)-N-(1-(3,4′-difluorobiphenyl-4-yl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamide (VFV), was identified. VFV has been further tested in cellular experiments and found to decrease proliferation of different cancer cell types. The crystal structures of human CYP51-VFV complexes (2.0 and 2.5 a) both display a 2:1 inhibitor/enzyme stoichiometry, provide molecular insights regarding a broader substrate profile, faster catalysis, and weaker susceptibility of human CYP51 to inhibition, and outline directions for the development of more potent inhibitors.

X-ray crystallography; cancer; cholesterol; cholesterol/biosynthesis; drug therapy/hypolipidemic drugs; cytochrome P450; enzymology/enzyme mechanisms; inhibition; membranes.

Human sterol 14α-demethylase as a target for anticancer chemotherapy: towards structure-aided drug design

Tatiana Y Hargrove 1, Laura Friggeri 1, Zdzislaw Wawrzak 2, Suneethi Sivakumaran 1, Eugenia M Yazlovitskaya 3, Scott W Hiebert 1, F Peter Guengerich 1, Michael R Waterman 1, Galina I Lepesheva 4

2016 Aug;