Allopregnanolone

Allopregnanolone

Names
IUPAC names 1-(3-hydroxy-10,13-dimethyl- 2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro- 1H-cyclopenta[a] phenanthren-17-yl)ethanone
Other names ALLO; Allo; ALLOP; AlloP; 5α-Pregnan-3α-ol-20-one; 3α-Hydroxy-5α-pregnan-20-one; 3α,5α-Tetrahydroprogesterone; 3α,5α-THP
Identifiers
CAS Number	516-54-1 N
3D model (Jmol)	Interactive image
ChemSpider	83760 N
PubChem CID	262961
UNII	S39XZ5QV8Y N
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+/m0/s1 N Key: AURFZBICLPNKBZ-SYBPFIFISA-N 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+/m0/s1 Key: AURFZBICLPNKBZ-SYBPFIFIBJ
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	318.49 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Allopregnanolone, also known as 5α-pregnan-3α-ol-20-one or 3α,5α-tetrahydroprogesterone (3α,5α-THP), as well as brexanolone (USAN), is an endogenous inhibitory pregnane neurosteroid. It is synthesized from progesterone, and is a potent positive allosteric modulator of the action of gamma-amininobutyric acid (GABA) at GABA_A receptor. Allopregnanolone has effects similar to those of other positive allosteric modulators of the GABA action at GABA_A receptor such as the benzodiazepines, including anxiolytic, sedative, and anticonvulsant activity.

Endogenously produced allopregnanolone exerts a pivotal neurophysiological role by fine-tuning of GABA_A receptor and modulating the action of several positive allosteric modulators and agonists at GABA_A receptor. The 21-hydroxylated derivative of this compound, tetrahydrodeoxycorticosterone (THDOC), is an endogenous inhibitory neurosteroid with similar properties to those of allopregnanolone, and the 3β-methyl analogue of allopregnanolone, ganaxolone, is under development to treat epilepsy and other conditions, including post-traumatic stress disorder (PTSD).

The biosynthesis of allopregnanolone in the brain starts with the conversion of progesterone into 5α-dihydroprogesterone by 5α-reductase type I. After that, 3α-hydroxysteroid dehydrogenase converts this intermediate into allopregnanolone. Allopregnanolone in the brain is produced by cortical and hippocampus pyramidal neurons and pyramidal-like neurons of the basolateral amygdala.