Practical one-pot conversion of 17beta-estradiol to 10beta-hydroxy- (p-quinol) and 10beta-chloro-17beta-hydroxyestra-1,4-dien-3-one

10β-Hydroxyestra-1,4-diene-3,17-dione as potential antiproliferative agent: in vitro biological evaluation and in silico studies

10β-Hydroxyestra-1,4-diene-3,17-dione (HEDD) is a natural product described as having neuroprotective activity. However, the cytotoxic properties of this quinol are barely studied. Thus, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed in six cell lines (MCF-7, T47-D, LNCaP, HepaRG, Caco-2 and NHDF). Additionally, an in vitro estrogenicity assay and a cell viability analysis together with in silico molecular docking studies were carried out in order to understand the potential mechanism of cytotoxicity. Computational predictions of its pharmacokinetic and toxicity properties were also performed. Surprisingly, HEDD displayed marked cytotoxic activity, particularly against hormone-dependent cancer cells and the flow cytometry analysis revealed that HEDD markedly reduced the viability of hepatic cancer cells. Molecular docking studies suggested a high affinity towards the estrogen receptor α and 17β-hydroxysteroid dehydrogenase type 1. Moreover, it was predicted that HEDD may have good oral bioavailability and a low maximum tolerated dose in humans.

Iron salt-promoted oxidation of steroidal phenols by m-chloroperbenzoic acid: a route to possible antitumor agents

A new oxidant, containing m-chloroperoxybenzoic acid (MCPBA) and an iron salt, was developed and used for oxidation of steroidal phenols to a quinol/epoxyquinol mixture. Reaction was optimized for estrone, by varying initiators (Fe-salts), reaction temperature, time and mode of MCPBA application. A series of five more substrates (17β-estradiol and its hydrophobized derivatives) was subjected to the optimized oxidation, providing corresponding p-quinols and 4β,5β-epoxyquinols in good to moderate yields. The obtained epoxyquinols were additionally transformed by oxidation, as well as the acid-catalyzed oxirane opening. In a preliminary study of the antiproliferative activity against human cancer cell lines, all newly synthesized compounds expressed moderate to high activity.

Iron salt-promoted reaction of estrone and its derivatives with meta-chloroperoxybenzoic acid was developed and epoxyquinols were further transformed. Most compounds showed in vitro antiproliferative activity.

Atropodiastereoselectivity in solid state BINOL synthesis: leads from the estradiol platform

A novel functionalized steroidal BINOL scaffold is produced via a remarkable sequence of dehydrogenation, chlorination and atroposelective phenolic coupling steps. Its formation is straightforwardly obtained in a one-step synthesis under solid state conditions and in the absence of chiral additives.