New Drug-Like Hydroxyphenylnaphthol Steroidomimetics As Potent And Selective 17 Beta-Hydroxysteroid Dehydrogenase Type 1 Inhibitors For The Treatment Of Estrogen-Dependent Diseases

Inhibition of 17 beta-hydroxysteroid dehydrogenase type 1 (17 beta-HSD1) is a novel and attractive approach to reduce the local levels of the active estrogen 17 beta-estradiol in patients with estrogen-dependent diseases like breast cancer or endometriosis. With the aim of optimizing the biological profile of 17 beta-HSD1 inhibitors from the hydroxyphenylnaphthol class, structural optimizations were performed at the 1-position of the naphthalene by introduction of different heteroaromatic rings as well as substituted phenyl groups. In the latter class of compounds, which were synthesized applying Suzuki-cross coupling, the 3-methane-sulfonamide 15 turned out to be a highly potent 17 beta-HSD1 inhibitor (IC50 = 15 nM in a cell-free assay). It was also very active in the cellular assay (T47D cells, IC50 = 71 nM) and selective toward 17 beta-HSD2 and the estrogen receptors alpha and beta. It showed a good membrane permeation and metabolic stability and was orally available in the rat.