Chemistry:Pregnanolone

Pregnanolone

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
CAS Number	128-20-1 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:1712 Y
ChEMBL	ChEMBL210952
ChemSpider	29132
PubChem CID	31402
UNII	BXO86P3XXW Y
InChI InChI=1S/C21H34O2/c1-13(22)17-6-7-18-16-5-4-14-12-15(23)8-10-20(14,2)19(16)9-11-21(17,18)3/h14-19,23H,4-12H2,1-3H3/t14-,15-,16+,17-,18+,19+,20+,21-/m1/s1 Key: AURFZBICLPNKBZ-YZRLXODZSA-N InChI=1/C21H34O2/c1-13(22)17-6-7-18-16-5-4-14-12-15(23)8-10-20(14,2)19(16)9-11-21(17,18)3/h14-19,23H,4-12H2,1-3H3/t14-,15-,16+,17-,18+,19+,20+,21-/m1/s1 Key: AURFZBICLPNKBZ-YZRLXODZBF
SMILES CC(=O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CC[C@H]4[C@@]3(CC[C@H](C4)O)C)C
Properties
Chemical formula	C21H34O2
Molar mass	318.501 g·mol−1
Pharmacology
Routes of administration	Intravenous injection
Pharmacokinetics:
Biological half-life	0.9–3.5 hours
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Tracking categories (test):

• SizeSet

Pregnanolone, also known as eltanolone, is an endogenous inhibitory neurosteroid which is produced in the body from progesterone. It is closely related to allopregnanolone, which has similar properties.

Biological activity

Pregnanolone is a positive allosteric modulator of the GABA_A receptor, as well as a negative allosteric modulator of the glycine receptor.

Biological function

Pregnanolone has sedative, anxiolytic, anesthetic, and anticonvulsant effects. During pregnancy, pregnanolone and allopregnanolone are involved in sedation and anesthesia of the fetus.

Biochemistry

Pregnanolone is synthesized from progesterone via the enzymes 5β-reductase and 3α-hydroxysteroid dehydrogenase, with 5β-dihydroprogesterone occurring as a metabolic intermediate. The elimination half-life of pregnanolone is between 0.9 and 3.5 hours.

Chemistry

Pregnanolone, also known as 3α,5β-tetrahydroprogesterone (3α,5β-THP) or as 5β-pregnan-3α-ol-20-one, is a naturally occurring pregnane steroid and a derivative of progesterone. Related compounds include allopregnanolone (3α,5α-THP; brexanolone), epipregnanolone (3β,5β-THP), hydroxydione, isopregnanolone (3β,5α-THP), and renanolone.

History

Pregnanolone was first isolated from the urine of pregnant women in 1937. Its anesthetic properties were first demonstrated in animals in 1957.

Research

Pregnanolone was investigated for clinical use as a general anesthetic under the name eltanolone (INN), but produced unwanted side effects such as convulsions on occasion, and for this reason, was never marketed.