Pregnanolone (3α-hydroxy-5β-pregnan-20-one or 3α,5β-tetrahydroprogesterone; sometimes abbreviated as 3α,5β-THP), also known as eltanolone (INN), is an endogenous neurosteroid that is biosynthesized from progesterone. It is a positive allosteric modulator of the GABAA receptor, as well as a negative allosteric modulator of the glycine receptor, and is known to have sedative, anxiolytic, anesthetic, and anticonvulsant effects. It was investigated for clinical use as a general anesthetic, but produced unwanted side effects such as convulsions on occasion, and for that reason was never marketed.

CAS：128-20-1
中文别名：5α-孕(甾)烷-3β-醇-20-酮;3α-羟基-5β-孕(甾)烷-20-酮;乙他诺隆;
英文别名：Pregnanolone II;5-Pregnan-3-ol-20-one;pregnanalone;Pregnan-20-one, 3-hydroxy-, (3α,5β)-;PREGNAN-3A-OL-20-ONE;3alpha-hydroxy-5beta-pregnan-20-one;Pregnan-20-one,3-hydroxy-, (3a,5b)-;Butabindide oxalate;
分子式：C21H34O2
分子量：318.493
精确质量：318.256
Psa：37.3
Logp：4.5952

MDL号：MFCD00067137
PubChem号：24898909
RTECS号：TU4384000

外观与性状：固体
密度：1.05 g/cm3 (20ºC)
沸点：431.2ºC at 760 mmHg
熔点：149ºC
折射率：1.524
稳定性：Stable at normal temperatures and pressures.
储存条件：Keep tightly closed. Store in a cool dry place.
蒸汽压：3.05E-09mmHg at 25°C

安全说明：S22; S36
危险类别码：R40
危险品标志：Xn
信号词：Warning
危险性防范说明：P281
危险性描述：H351
危险标志：GHS08

用途
激素类药。