RU-58841
RU-58841, also known as PSK-3841 or HMR-3841, is a nonsteroidal antiandrogen which was initially developed in the 1980s. It was formerly under investigation by ProStrakan for potential use as a topical treatment for androgen-dependent conditions including acne, pattern hair loss, and excessive hair growth. The compound is similar in structure to the NSAA RU-58642 but contains a different side-chain. These compounds are similar in chemical structure to nilutamide, which is related to flutamide, bicalutamide, and enzalutamide, all of which are NSAAs similarly. RU-58841 can be synthesized either by building the hydantoin moiety or by aryl coupling to 5,5-dimethylhydantoin.
RU-58841 produces cyanonilutamide and RU-59416 as metabolites in animals. Cyanonilutamide has relatively low affinity for the androgen receptor but shows significant antiandrogenic activity in animals. RU-59416 has very low affinity for the androgen receptor.