5818. Melengestrol Acetate

Nomenclature

CAS number: 2919-66-6
17-(Acetyloxy)-6-methyl-16-methylenepregna-4,6-diene-3,20-dione; 6α-methyl-6-dehydro-16-methylene-17-acetoxyprogesterone; MGA (Pharmacia & Upjohn).
C25H32O4; mol wt 396.52.
C 75.73%, H 8.13%, O 16.14%.

Description and references

Orally active progestational steroid. Prepn: D. N. Kirk et al., GB 886619; eidem, US 3332940 (1962, 1967 both to British Drug Houses). Environmental degradation study: B. Schiffer et al., Environ. Health Perspect. 109, 1145 (2001). Receptor binding study: G. A. Perry et al., Domest. Anim. Endocrinol. 28, 147 (2005). Review of pharmacology in animals: R. G. Zimbelman et al., J. Am. Vet. Med. Assoc. 157, 1528-1536 (1970); of use in control of bovine estrus: D. J. Patterson et al., J. Anim. Sci. 67, 1895-1906 (1989).

Chemical structure

Properties

Needles from acetone/hexane, mp 224-226°. [α]D23 -127° (c = 0.31 in chloroform). uv max (ethanol): 287.5 nm (log ε 4.35). LD50 (mg/kg): >8000 orally in rats; >2500 i.p. in mice (Zimbelman).

Therapeutic Category (Veterinary)

Progestogen; growth promotant.