5β-dihydroprogesterone

5β-Dihydroprogesterone

Names
IUPAC name Pregnanedione; 5β-Pregnane-3,20-dione
Identifiers
CAS Number	128-23-4
3D model (JSmol)	Interactive image
ChemSpider	83723
PubChem CID	92745
SMILES CC(=O)C1CCC2C1(CCC3C2CCC4C3(CCC(=O)C4)C)C
Properties
Chemical formula	C21H32O2
Molar mass	316.47758 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

5β-Dihydroprogesterone (5β-DHP), also known as pregnanedione, as well as 5β-pregnane-3,20-dione, is an endogenous neurosteroid and an intermediate in the biosynthesis of pregnanolone and epipregnanolone from progesterone. It is synthesized from progesterone by the enzyme 5β-reductase. 5β-DHP has been found to act as a positive allosteric modulator of the GABA_A receptor (albeit with an affinity for this receptor regarded as relatively low (in comparison to 3α-hydroxylated progesterone metabolites such as pregnanolone and allopregnanolone)) and also as a negative allosteric modulator of the GABA_A-rho receptor. In accordance with the former action, it is reported to possess anesthetic, anxiolytic, and antinociceptive effects. 5β-DHP has been found to act as an agonist of the pregnane X receptor (PXR) as well (albeit weakly (EC₅₀ >10,000 µM)), and has been found to regulate uterine contractility through activation of this receptor. Unlike 5α-dihydroprogesterone, 5β-DHP does not possess affinity for the progesterone receptor, and hence, is not a progestogen.