Epitestosterone
Epitestosterone, or isotestosterone, also known as 17α-testosterone or as androst-4-en-17α-ol-3-one, is an endogenous steroid and an epimer of the androgen sex hormone testosterone. It is a weak competitive antagonist of the androgen receptor (AR) and a potent 5α-reductase inhibitor.
Names | |
---|---|
IUPAC name
17α-Hydroxyandrost-4-en-3-one | |
Systematic IUPAC name
(1R,3aS,3bR,9aR,9bS,11aS)-1-Hydroxy-9a,11a-dimethyl-1,2,3,3a,3b,4,5,8,9,9a,9b,10,11,11a-tetradecahydro-7H-cyclopenta[a]phenanthren-7-one | |
Other names
Isotestosterone; 17α-Testosterone; Androst-4-en-17α-ol-3-one | |
Identifiers | |
3D model (JSmol) |
|
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.169.813 |
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
| |
SMILES
| |
Properties | |
C19H28O2 | |
Molar mass | 288.431 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
Structurally, epitestosterone differs from testosterone only in the configuration at the hydroxy-bearing carbon, C17. Epitestosterone is believed to form in a similar way to testosterone; a 1993 study found that around 50% of epitestosterone production in human males can be ascribed to the testis, although the exact pathway of its formation is still the subject of research. It has been shown to accumulate in mammary cyst fluid and in the prostate. Epitestosterone levels are typically highest in young males; however, by adulthood, most healthy males exhibit a testosterone to epitestosterone ratio (T/E ratio) of about 1:1.