title: New steroidal lactones as 5α-reductase inhibitors and antagonists for the androgen receptor.
abstract: This study reports the synthesis of several new steroidal lactones: 5α,6β-dibromo-17a-oxa-D-homoandrostane-3β-yl-3'-oxapentanoate (11), 5α,6β-dibromo-17a-oxa-D-homoandrostane-3β-yl-propanoate (12), 5α,6β-dibromo-17a-oxa-D-homoandrostane-3β-yl-butanoate (13), 5α,6β-dibromo-17a-oxa-D-homoandrostane-3β-yl-pentanoate (14), 5α,6β-dibromo-17a-oxa-D-homoandrostane-3β-yl-hexanoate (15), 17a-oxa-D-homoandrost-5-en-17-one-3β-yl-3'-oxapentanoate (16), 17a-oxa-D-homoandrost-5-en-17-one-3β-yl-propanoate (17), 17a-oxa-D-homoandrost-5-en-17-one-3β-yl-butanoate (18), 17a-oxa-D-homoandrost-5-en-17-one-3β-yl-pentanoate (19) and 17a-oxa-D-homoandrost-5-en-17-one-3β-yl-hexanoate (20) with a therapeutic potential as antiandrogens. The biological effect of these steroids was demonstrated in in vivo as well as in vitro experiments. In the in vivo experiments, we measured the activity of ten new steroidal derivatives on the weight of the prostate and seminal vesicle glands of gonadectomized hamsters treated with testosterone. For the in vitro studies, we determined the IC(50) values by measuring the concentration of the steroidal derivatives that inhibits 50% of the activity of the 5α-reductase enzyme present in human prostate and also its binding capacity to the androgen receptors (AR) obtained from rat's prostate cytosol. The results from these experiments indicated that compounds 11-20, significantly decreased the weight of the prostate and seminal vesicles as compared to testosterone treated animals; this reduction of the weight of these glands was comparable to that produced by Finasteride. On the other hand, compounds 11-20 inhibited the enzyme 5α-reductase, with compounds 14-19 (IC(50) values of 4.2 ± 0.95, 0.025 ± 0.003, 1.2 ± 0.45, 1.2 ± 0.1, 0.028 ± 0.003, and 0.069 ± 0.005 nM, respectively) showing the highest inhibitory activity. The results from the in vitro experiments indicated that only 15-17 bind to the AR.
authors.affiliation: Department of Pharmacy, Faculty of Chemistry, National University of Mexico, Mexico, DF, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: Garrido
authors.forename: Eugene
authors.initials: E
authors.lastname: Bratoeff
authors.forename: Dulce
authors.initials: D
authors.lastname: Bonilla
authors.forename: Juan
authors.initials: J
authors.lastname: Soriano
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Heuze
authors.forename: Marisa
authors.initials: M
authors.lastname: Cabeza
mesh_terms: D058891:5-alpha Reductase Inhibitors / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D007783:Lactones / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011944:Receptors, Androgen / Q000187:drug effects*; D013055:Spectrophotometry, Infrared; D013256:Steroids / Q000494:pharmacology*
chemical_list: D058891:5-alpha Reductase Inhibitors; D007783:Lactones; D011944:Receptors, Androgen; D013256:Steroids