17α-Ethynyl-3β-androstanediol
17α-Ethynyl-3β-androstanediol, also known as 17α-ethynyl-5α-androstane-3β,17β-diol, is a synthetic estrogen and a 17α-substituted derivative of 3β-androstanediol which was never marketed.
17α-Ethynyl-3β-androstanediol shows high affinity for the estrogen receptors in vitro, and activates the estrogen receptors in vitro. It also has weak affinity for the androgen receptor in vitro, but doesn't appear to activate the receptor. 17α-Ethynyl-3β-androstanediol may produce 17α-ethynyl-3α-androstanediol and 5α-dihydroethisterone as active metabolites in vivo. In accordance with its in-vitro estrogenic activity, 17α-ethynyl-3β-androstanediol produces estrogenic effects like uterotrophy and testicular atrophy in animals.
Esters of 17α-ethynyl-3β-androstanediol have been developed and studied.
17α-Ethynyl-3β-androstanediol is a positional isomer of 17α-ethynyl-3α-androstanediol, and is a metabolite of this compound in vivo via metabolic inversion of the position of the C3 hydroxyl group. It may be involved in the biological activity of 17α-ethynyl-3α-androstanediol.
Analogues of 17α-ethynyl-3β-androstanediol include 17α-ethynyl-3α-androstanediol, ethinylandrostenediol, ethandrostate, ethinylestradiol, ethisterone, and 5α-dihydroethisterone.
