5β-Dihydrotestosterone

{{Distinguish|5α-Dihydrotestosterone}}

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| ImageFile = 5β-Dihydrotestosterone.svg

| ImageSize = 250

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| IUPACName = 17β-Hydroxy-5β-androstan-3-one

| SystematicName = (1S,3aS,3bR,5aR,9aS,9bS,11aS)-1-Hydroxy-9a,11a-dimethylhexadecahydro-7H-cyclopenta[a]phenanthren-7-one

| OtherNames = 5β-Androstan-17β-ol-3-one; Etiocholan-17β-ol-3-one; 5β-Dihydrotestosterone; 5β-DHT

| Section1 = {{Chembox Identifiers

| CASNo = 571-22-2

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = SVX1G0C5VD

| ChEBI = 2150

| ChEMBL = 373357

| ChemSpiderID = 10827

| PubChem = 11302

| SMILES = C[C@]12CCC(=O)C[C@H]1CC[C@@H]3[C@@H]2CC[C@]4([C@H]3CC[C@@H]4O)C

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| Section2 = {{Chembox Properties

| C = 19 | H = 30 | O = 2

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5β-Dihydrotestosterone (5β-DHT), also known as 5β-androstan-17β-ol-3-one or as etiocholan-17β-ol-3-one, is an etiocholane (5β-androstane) steroid as well as an inactive metabolite of testosterone formed by 5β-reductase in the liver and bone marrow{{cite book|title=Hormones, Brain and Behavior Online|url=https://books.google.com/books?id=CATnr24wGL4C&pg=PT2262|date=18 June 2002|publisher=Academic Press|isbn=978-0-08-088783-8|pages=2262–}}{{cite book|author1=H.-J. Bandmann|author2=R. Breit|author3=E. Perwein|title=Klinefelter's Syndrome|url=https://books.google.com/books?id=NGgrBgAAQBAJ&pg=PT293|date=6 December 2012|publisher=Springer Science & Business Media|isbn=978-3-642-69644-2|pages=293–}} and an intermediate in the formation of 3α,5β-androstanediol and 3β,5β-androstanediol (by 3α- and 3β-hydroxysteroid dehydrogenase) and, from them, respectively, etiocholanolone and epietiocholanolone (by 17β-hydroxysteroid dehydrogenase).{{cite book|author1=Shlomo Melmed|author2=Kenneth S. Polonsky|author3=P. Reed Larsen|author4=Henry M. Kronenberg|title=Williams Textbook of Endocrinology|url=https://books.google.com/books?id=YZ8_CwAAQBAJ&pg=PA711|date=30 November 2015|publisher=Elsevier Health Sciences|isbn=978-0-323-29738-7|pages=711–}}{{cite book|author1=Anita H. Payne|author2=Matthew P. Hardy|title=The Leydig Cell in Health and Disease|url=https://books.google.com/books?id=x4ttqKIAOg0C&pg=PA186|date=28 October 2007|publisher=Springer Science & Business Media|isbn=978-1-59745-453-7|pages=186–}} Unlike its isomer 5α-dihydrotestosterone (5α-DHT or simply DHT), 5β-DHT either does not bind to or binds only very weakly to the androgen receptor. 5β-DHT is notable among metabolites of testosterone in that, due to the fusion of the A and B rings in the cis orientation, it has an extremely angular molecular shape, and this could be related to its lack of androgenic activity.{{cite book|author1=B.A. Cooke|author2=H.J. Van Der Molen|author3=R.J.B. King|title=Hormones and their Actions|url=https://books.google.com/books?id=bWUVADC74d8C&pg=PA173|date=1 November 1988|publisher=Elsevier|isbn=978-0-08-086077-0|pages=173–}} 5β-DHT, unlike 5α-DHT, is also inactive in terms of neurosteroid activity,{{cite book|title=Current Topics in Membranes and Transport|url=https://books.google.com/books?id=ocWRusKe5WAC&pg=PA169|date=1 February 1988|publisher=Academic Press|isbn=978-0-08-058502-4|pages=169–}}{{cite book|author=Abraham Weizman|title=Neuroactive Steroids in Brain Function, Behavior and Neuropsychiatric Disorders: Novel Strategies for Research and Treatment|url=https://books.google.com/books?id=uABKkFdPjhkC&pg=PA210|date=1 February 2008|publisher=Springer Science & Business Media|isbn=978-1-4020-6854-6|pages=210–}} although its metabolite, etiocholanolone, does possess such activity.{{cite journal |vauthors=Li P, Bracamontes J, Katona BW, Covey DF, Steinbach JH, Akk G | title = Natural and enantiomeric etiocholanolone interact with distinct sites on the rat alpha1beta2gamma2L GABAA receptor | journal = Mol. Pharmacol. | volume = 71 | issue = 6 | pages = 1582–90 |date=June 2007 | pmid = 17341652 | doi = 10.1124/mol.106.033407 | pmc = 3788649 }}{{cite journal |vauthors=Kaminski RM, Marini H, Kim WJ, Rogawski MA | title = Anticonvulsant activity of androsterone and etiocholanolone | journal = Epilepsia | volume = 46 | issue = 6 | pages = 819–27 |date=June 2005 | pmid = 15946323 | pmc = 1181535 | doi = 10.1111/j.1528-1167.2005.00705.x }}