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18-Methylsegesterone acetate
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Chemical compound
[(8R,9S,10R,13S,14S,17R)-17-Acetyl-13-ethyl-16-methylidene-3-oxo-2,6,7,8,9,10,11,12,14,15-decahydro-1H-cyclopenta[a]phenanthren-17-yl] acetate 18-Methylsegesterone acetate.svg skin-invert-image 200px Progestin; Progestogen; Progestogen ester correct CAS 192722-05-7 9908093 8083745 18-Methyl-SGA; 13β-Ethyl-SGA; 18-Methylnestorone; 18-Methyl-NES; 13β-Ethylnestorone; 13β-Ethyl-NES; 18-Methylelcometrine; 16-Methylene-17α-acetoxy-18-methyl-19-norprogesterone; 16-Methylene-17α-hydroxy-18-methyl-19-norpregn-4-ene-3,20-dione acetate 24 32 4 CC[C@]12CC[C@H]3[C@H]([C@@H]1CC(=C)[C@@]2(C(=O)C)OC(=O)C)CCC4=CC(=O)CC[C@H]34 1S/C24H32O4/c1-5-23-11-10-20-19-9-7-18(27)13-17(19)6-8-21(20)22(23)12-14(2)24(23,15(3)25)28-16(4)26/h13,19-22H,2,5-12H2,1,3-4H3/t19-,20+,21+,22-,23-,24-/m0/s1 YIAUAVGJQYAQFE-ZUYVPRDGSA-N
18-Methylsegesterone acetate (18-methyl-SGA; also known as 18-methylnestorone) is a progestin medication of the 19-norprogesterone group which was never marketed. Tuba Z, Bardin CW, Dancsi A, Francsics-Czinege E, Molnár C, Csörgei J, Falkay G, Koide SS, Kumar N, Sundaram K, Dukát-Abrók V, Balogh G Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate Steroids 65 5 266–74 May 2000 10751638 10.1016/S0039-128X(99)00109-9 37188669 Sitruk-Ware R, Small M, Kumar N, Tsong YY, Sundaram K, Jackanicz T Nestorone: clinical applications for contraception and HRT Steroids 68 10–13 907–13 November 2003 14667982 10.1016/S0039-128X(03)00140-5 34984413 Kumar N, Fagart J, Liere P, Mitchell SJ, Knibb AR, Petit-Topin I, Rame M, El-Etr M, Schumacher M, Lambert JJ, Rafestin-Oblin ME, Sitruk-Ware R Nestorone as a Novel Progestin for Nonoral Contraception: Structure-Activity Relationships and Brain Metabolism Studies Endocrinology 158 1 170–182 January 2017 27824503 5412978 10.1210/en.2016-1426 It was first described in a patent in 1997 and then in a literature paper in 2003.18-methyl 16-methylene 19-nor pregnane derivatives as progestins, pharmaceutical compositions containing them and process for the preparation thereof. https://patents.google.com/patent/WO1997023498A1/en 18-Methyl-SGA is the C18 methyl or C13β ethyl derivative of segesterone acetate (SGA; 16-methylene-17α-acetoxy-19-norprogesterone), and shows 3 to 10 times the progestogenic potency of SGA in bioassays. This is analogous to the case of the 19-nortestosterone progestin norethisterone and its 18-methyl derivative levonorgestrel, the latter showing substantially increased potency relative to the former similarly. As SGA is already one of the most potent progestins to have been developed, with 100-fold the potency of progesterone and 10-fold the potency of levonorgestrel in bioassays, 18-methyl-SGA is an extremely potent progestogen, among if not the most potent known. Kumar N, Koide SS, Tsong Y, Sundaram K Nestorone: a progestin with a unique pharmacological profile Steroids 65 10–11 629–36 2000 11108869 10.1016/S0039-128X(00)00119-7 13722269
SGA is a highly selective progestogen. Like SGA, 18-methyl-SGA shows negligible affinity for the androgen receptor. While 18-methyl-SGA has not been assessed at the other steroid hormone receptors, it is expected to be highly selective for the progesterone receptor similarly to SGA. 18-Methyl-SGA shows over 16 times the affinity of progesterone for the progesterone receptor expressed in rat uterus. In terms of oral bioavailability, it is known that SGA is not active orally, while the oral activity of 18-methyl-SGA is unknown. The addition of an 18-methyl group to SGA is unlikely to affect its rate of delivery from sustained release systems. As such, 18-methyl-SGA should be ideally suited for use via routes of administration like subcutaneous implants and transdermal patches.
Comparison of potencies of selected progestogens in animals Progestogen PR Progesterone receptor RBA Relative binding affinity(rat uterus) Claubergassaya Pregnancymaintenance 18-Methyl-SGA 355% 0.3 μg 0.03 mg Segesterone acetate 107% 1 μg 0.3 mg Levonorgestrel 100% 3 μg 0.3 mg Progesterone 22% 100 μg 1.0 mg Footnotes: a = Minimum effective dose. Sources:
See also
List of progestogen esters § Esters of 19-norprogesterone derivatives
References
Category:Abandoned drugs
Category:Acetate esters
Category:Alkene derivatives
Category:Diketones
Category:Norpregnanes
Category:Progestogen esters
Category:Progestogens
Category:Vinylidene compounds