Etiocholanolone (5β-Androsterone) is a testosterone excretion aid with anticonvulsant (antiepileptic/antiseizure) activity. Relative to its enantiomeric form, etiocholanolone is a weaker PAM (positive allosteric modulator) of the neurosterol-like GABAA receptor.

Physicochemical Properties

Molecular Formula	C19H30O2
Molecular Weight	290.44
Exact Mass	290.224
CAS #	53-42-9
Related CAS #	Etiocholanolone-d5;1620102-33-1;Etiocholanolone-d2;2687960-82-1
PubChem CID	5880
Appearance	White to off-white solid powder
Density	1.1±0.1 g/cm3
Boiling Point	413.1±45.0 °C at 760 mmHg
Melting Point	148～150°C (lit.)
Flash Point	176.4±21.3 °C
Vapour Pressure	0.0±2.2 mmHg at 25°C
Index of Refraction	1.536
LogP	3.75
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	0
Heavy Atom Count	21
Complexity	459
Defined Atom Stereocenter Count	7
SMILES	C[C@]12CC[C@H](C[C@H]1CC[C@@H]3[C@@H]2CC[C@]4([C@H]3CCC4=O)C)O
InChi Key	QGXBDMJGAMFCBF-BNSUEQOYSA-N
InChi Code	InChI=1S/C19H30O2/c1-18-9-7-13(20)11-12(18)3-4-14-15-5-6-17(21)19(15,2)10-8-16(14)18/h12-16,20H,3-11H2,1-2H3/t12-,13-,14+,15+,16+,18+,19+/m1/s1
Chemical Name	(3R,5R,8R,9S,10S,13S,14S)-3-hydroxy-10,13-dimethyl-1,2,3,4,5,6,7,8,9,11,12,14,15,16-tetradecahydrocyclopenta[a]phenanthren-17-one
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	When ethiocholesterone (10 μM) is administered in conjunction with GABA, the relative frequency of long openings increases (OT3 percent, site A2 effect). However, it has no effect on the duration of long openings (site B effect) or the relative frequency invalid. The closure time component's frequency linked to activation (the site A1 effect) [2].
ln Vivo	Etiocholanolone (ip; 0-109.1 mg/kg; single dosage) had ED50 values of 57.6 and 109.1 mg/kg in the 6-Hz and PTZ tests, respectively. The protective activity in the 5β,3α-A 6-Hz test lasted 2 hours, which was shorter than ent-5β,3α-A therapy (3 hours) in mice [1].
ADME/Pharmacokinetics	Metabolism / Metabolites Etiocholanolone has known human metabolites that include Etiocholanolone glucuronide.
References	[1]. Natural and Enantiomeric Etiocholanolone Interact With Distinct Sites on the Rat alpha1beta2gamma2L GABAA Receptor. Mol Pharmacol. 2007 Jun;71(6):1582-90. [2]. Anticonvulsant Potencies of the Enantiomers of the Neurosteroids Androsterone and Etiocholanolone Exceed Those of the Natural Forms. Psychopharmacology (Berl). 2014 Sep;231(17):3325-32.
Additional Infomation	3alpha-hydroxy-5beta-androstan-17-one is an androstanoid that is 5beta-androstane substituted by an alpha-hydroxy group at position 3 and an oxo group at position 17. It is a metabolite of testosterone in mammals. It has a role as a human metabolite and a mouse metabolite. It is a 3alpha-hydroxy steroid, a 17-oxo steroid and an androstanoid. It derives from a hydride of a 5beta-androstane. Etiocholanolone has been reported in Homo sapiens with data available. Etiocholanolone is a 17-ketosteroid which excreted in the urine as a metabolite of steroid hormones. The most common form of etiocholanolone present in the urine is the sulfate salt. This agent, also known as 5-isoandrosterone, may be used to evaluate adrenal cortex function, bone marrow performance and, in neoplastic disease, for immunostimulation. (NCI04) The 5-beta-reduced isomer of ANDROSTERONE. Etiocholanolone is a major metabolite of TESTOSTERONE and ANDROSTENEDIONE in many mammalian species including humans. It is excreted in the URINE.

Solubility Data

Solubility (In Vitro)

DMSO : ~50 mg/mL (~172.15 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.61 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (8.61 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (8.61 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.4431 mL	17.2153 mL	34.4305 mL
	5 mM	0.6886 mL	3.4431 mL	6.8861 mL
	10 mM	0.3443 mL	1.7215 mL	3.4431 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.