Melengestrol acetate is a progesterone analogue that works as an orally bioactive corticosteroid that promotes endometrial proliferation, maintenance of pregnancy, and delayed menstrual activity. Melengestrol acetate is a contraceptive agent used to promote growth and suppress estrus in animals. Melengestrol acetate inhibits androgen-dependent and -independent prostate tumor growth in animal models and may be useful in cancer research.

Physicochemical Properties

Molecular Formula	C25H32O4
Molecular Weight	396.52
Exact Mass	396.23
CAS #	2919-66-6
Related CAS #	Melengestrol acetate-d3;Melengestrol acetate-d6;Melengestrol acetate-d2
PubChem CID	250948
Appearance	White to yellow solid powder
Density	1.1±0.1 g/cm3
Boiling Point	516.1±50.0 °C at 760 mmHg
Melting Point	202-204ºC
Flash Point	221.7±30.2 °C
Vapour Pressure	0.0±1.3 mmHg at 25°C
Index of Refraction	1.555
LogP	4.21
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	3
Heavy Atom Count	29
Complexity	893
Defined Atom Stereocenter Count	6
SMILES	CC1=C[C@@H]2[C@H](CC[C@]3([C@H]2CC(=C)[C@@]3(C(=O)C)OC(=O)C)C)[C@@]4(C1=CC(=O)CC4)C
InChi Key	UDKABVSQKJNZBH-DWNQPYOZSA-N
InChi Code	InChI=1S/C25H32O4/c1-14-11-19-20(23(5)9-7-18(28)13-21(14)23)8-10-24(6)22(19)12-15(2)25(24,16(3)26)29-17(4)27/h11,13,19-20,22H,2,7-10,12H2,1,3-6H3/t19-,20+,22+,23-,24+,25+/m1/s1
Chemical Name	[(8R,9S,10R,13S,14S,17R)-17-acetyl-6,10,13-trimethyl-16-methylidene-3-oxo-1,2,8,9,11,12,14,15-octahydrocyclopenta[a]phenanthren-17-yl] acetate
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 Vivo	AT3 tumor growth is inhibited by megenestrol acetate (sc; 10 mg/kg; 9 days) by about 53%. Additionally, it results in a decrease of the seminal vesicles and a 54% weight loss of the ventral prostate in adult male CCFl rats[1]. In rats, oral treatment of meleengestrol acetate (10 mg/kg) results in a 58.8% growth inhibition of Dunning R3327-AT3 tumors and a 51.6% reduction in adrenal weight[1].
References	[1]. Melengestrol acetate and megestrol acetate are prostatic tumor inhibiting agents. Biochem Cell Biol. 1990 Oct;68(10):1181-8. [2]. BIOLOGIC EFFECTS OF MELENGESTROL ACETATE. Fertil Steril. Jul-Aug 1964;15:416-32. [3]. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/melengestrol-acetate.
Additional Infomation	Melengestrol acetate is a corticosteroid hormone. A 6-methyl progesterone acetate with reported glucocorticoid activity and effect on estrus. Melengestrol Acetate is a progestogen-like compound used as a cattle feed additive for its growth promoting effects and suppression of estrus (heat) in heifers. Critics have claimed that hormones used as growth promotants in cattle may cause breast cancer. (NCI) A 6-methyl PROGESTERONE acetate with reported glucocorticoid activity and effect on ESTRUS. See also: Melengestrol (has active moiety); Melengestrol Acetate; Tylosin (component of); Melengestrol Acetate; Monensin (component of) ... View More ...

Solubility Data

Solubility (In Vitro)

DMSO: 25 mg/mL (63.05 mM)

Solubility (In Vivo)

Solubility in Formulation 1: 2.5 mg/mL (6.30 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication. 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 (6.30 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	2.5219 mL	12.6097 mL	25.2194 mL
	5 mM	0.5044 mL	2.5219 mL	5.0439 mL
	10 mM	0.2522 mL	1.2610 mL	2.5219 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.