Nisterime acetate explained

Nisterime acetate (USAN) (developmental code name ORF-9326), also known as 2α-chloro-4,5α-dihydrotestosterone O-(p-nitrophenyl)oxime 17β-acetate or as 2α-chloro-5α-androstan-17β-ol-3-one O-(p-nitrophenyl)oxime 17β-acetate, is a synthetic, orally active anabolic-androgenic steroid (AAS) and a derivative of dihydrotestosterone (DHT) that was developed as a postcoital contraceptive but was never marketed.^{[1] [2] [3]} It is an androgen ester – specifically, the C17α acetate ester of nisterime. Unlike antiprogestogens like mifepristone, nisterime acetate does not prevent implantation and instead induces embryo resorption as well as interrupts the post-implantation stage of pregnancy.^[4]

Nisterime acetate is described as an androgen by some sources.^[5] However, it has also been reported that the drug lacks hormonal activity in bioassays, including androgenic, estrogenic, or progestogenic activity (as well as antagonistic activity).^[6] This finding has been described as puzzling in light of the potent abortifacient activity of the drug in animals and it has been said that its mechanism of action remains unknown.

See also

• Epostane
• Istaroxime

Notes and References

1. Book: Elks J . The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. 14 November 2014. Springer. 978-1-4757-2085-3. 876–.
2. Patrick JE, Weintraub HS, McGuire JL . Disposition of ORF 9326, a novel contragestational steroid, in animals . Steroids . 32 . 2 . 147–156 . September 1978 . 102053 . 10.1016/0039-128x(78)90001-6 . 106098 .
3. Hahn DW, Allen GO, Greenslade FC . The Post-Implantive Contragestational Activity of 17β-acetoxy-2α-chloro-3-(p-nitrophenoxy) imino-5α androstane (ORF 9326) in the Rat . Federation Proceedings . 36 . 3 . 1977 . 342 . 74670821 .
4. Book: Hahn DW, McGuire JL . The Use of Pharmacological Agents to Study Implantation . Glasser SR, Bullock DW . Cellular and Molecular Aspects of Implantation. https://books.google.com/books?id=iknTBwAAQBAJ&pg=PA479. 6 December 2012. Springer Science & Business Media. 978-1-4613-3180-3. 479–.
5. Web site: Nisterime acetate . KEGG DRUG .
6. Book: Zatuchni GI, Labbok MH, Sciarra JJ . Research frontiers in fertility regulation. 1980 . Harper & Row . 978-0-06-142902-6 . ORF 9326 (17β-acetoxy-2α-chloro-3(p-nitrophenoxy) imino-5-androstane) is a derivative of dihydrotestosterone (Fig. 33-1). This compound was found to interrupt pregnancy in a number of species, but the fact that it has no hormonal activity is puzzling and its mechanism of action is still unknown. . 368 .