Discovery of diarylhydantoins as new selective androgen receptor modulators.

A novel selective androgen receptor modulator scaffold has been discovered through structural modifications of hydantoin antiandrogens. Several 4-(4-hydroxyphenyl)-N-arylhydantoins displayed partial agonism with nanomolar in vitro potency in transactivation experiments using androgen receptor (AR) transfected cells. In a standard castrated male rat model, several compounds showed good anabolic activity on levator ani muscle, dissociated from the androgenic activity on ventral prostate, after oral dosing at 30 mg/kg. (+)-4-[3,4-Dimethyl-2,5-dioxo-4-(4-hydroxyphenyl)imidazolidin-1-yl]-2-(trifluoromethyl)benzonitrile ((+)-11b) displayed anabolic potency with a strong dissociation between levator ani muscle and ventral prostate (A(50) = 0.5 mg/kg vs 70 mg/kg). The binding modes of two compounds, including (+)-11b, within the AR ligand-binding domain have been studied by cocrystallization experiments using a coactivator-like peptide. Both compounds bound to the same site, and the overall structures of the AR were very similar.