|Systematic IUPAC name
3β-Androstanediol; 3β-Diol; Maxterone
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||292.463 g·mol−1|
|Melting point||168–170 °C (334–338 °F; 441–443 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
3β-Androstanediol, also known as 5α-androstane-3β,17β-diol, and often shortened to 3β-diol, is an endogenous steroid hormone. It is a 5α-reduced and 17β-hydroxylated metabolite of dehydroepiandrosterone (DHEA) as well as a 3β-hydroxylated metabolite of dihydrotestosterone (DHT). 3β-Diol is a selective, potent, high-affinity full agonist of the ERβ, and hence, an estrogen. It has higher affinity for this receptor than estradiol.[contradictory] In contrast to ERβ, 3β-diol does not bind to the androgen receptor (AR). 3β-Diol has been reported to also bind to ERα with low nanomolar affinity, with several-fold lower affinity relative to ERβ. It has approximately 3% and 7% of the affinity of estradiol at the ERα and ERβ, respectively.[contradictory] Unlike its 3α-isomer, 3α-androstanediol (3α-diol), 3β-diol does not bind to the GABAA receptor.
3β-Diol appears to be the endogenous ligand of ERβ in the prostate gland, and as a result of activation of the ERβ, 3β-diol has antiproliferative effects against prostate cancer cells. Through the ERβ, 3β-diol positively regulates oxytocin neurons and signaling in the paraventricular nucleus of hypothalamus (PVN), and has been found to have antidepressant, anxiolytic, cognitive-enhancing, and stress-relieving effects via this action. Androgens, including testosterone and dihydrotestosterone (DHT), are known to downregulate the hypothalamic-pituitary-adrenal axis, and this has been found to be due in part or full to their conversion into 3β-diol rather than to activation of the AR.