 | |
| Names | |
|---|---|
| IUPAC name 3α-Hydroxy-5β-pregnan-20-one | |
| Systematic IUPAC name 1-[(1S,3aS,3bR,5aR,7R,9aS,9bS,11aS)-7-Hydroxy-9a,11a-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-1-yl]ethan-1-one | |
| Other names Eltanolone; 5β-Pregnan-3α-ol-20-one; 3α,5β-Tetrahydroprogesterone; 3α,5β-THP; 3α-Hydroxy-5β-tetrahydroprogesterone | |
| Identifiers | |
| |
3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.162.192 |
| UNII | |
| |
| |
| Properties | |
| C21H34O2 | |
| Molar mass | 318.501 g·mol−1 |
| Pharmacology | |
| Intravenous injection[1] | |
| Pharmacokinetics: | |
| 0.9–3.5 hours[1][2][3] | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Pregnanolone, also known aseltanolone, is anendogenousinhibitoryneurosteroid which is produced in the body fromprogesterone.[4] It is closely related toallopregnanolone, which has similar properties.[4]
Pregnanolone is apositive allosteric modulator of theGABAA receptor,[4] as well as anegative allosteric modulator of theglycine receptor.[5]
Pregnanolone hassedative,anxiolytic,anesthetic, andanticonvulsant effects.[4][5][1] Duringpregnancy, pregnanolone andallopregnanolone are involved insedation andanesthesia of thefetus.[6][7]
Pregnanolone is synthesized fromprogesterone via theenzymes5β-reductase and3α-hydroxysteroid dehydrogenase, with5β-dihydroprogesterone occurring as ametabolic intermediate. Theelimination half-life of pregnanolone is between 0.9 and 3.5 hours.[1][2][3]
Pregnanolone, also known as 3α,5β-tetrahydroprogesterone (3α,5β-THP) or as 5β-pregnan-3α-ol-20-one, is anaturally occurringpregnanesteroid and aderivative ofprogesterone. Related compounds includeallopregnanolone (3α,5α-THP; brexanolone),epipregnanolone (3β,5β-THP),hydroxydione,isopregnanolone (3β,5α-THP), andrenanolone.
Pregnanolone was first isolated from theurine of pregnant women in 1937.[1] Its anesthetic properties were first demonstrated in animals in 1957.[1]
Pregnanolone was investigated for clinical use as ageneral anesthetic under the nameeltanolone (INNTooltip International Nonproprietary Name), but produced unwantedside effects such asconvulsions on occasion, and for this reason, was never marketed.[5][8][1]
[...] the fetus is sedated by the low oxygen tension of the fetal blood and the neurosteroid anesthetics pregnanolone and the sleep-inducing prostaglandin D2 provided by the placenta (36).
