Discovery of 7α-substituted dihydrotestosterones as androgen receptor pure antagonists and their structure–activity relationships

A series of 7α-substituted dihydrotestosterone derivatives were synthesized and evaluated for androgen receptor (AR) pure antagonistic activity. From reporter gene assay (RGA), the compound with a side chain containing N-n-butyl-N-methyl amide (19a) showed pure antagonistic activity (IC50 = 340 nM, FI5 > 10,000 nM), whereas known AR antagonists showed partial agonistic activities. The optimization of 19a led to compound 23 (CH4892280), which showed more potent pure antagonistic activity (IC50 = 190 nM, FI5 > 10,000 nM). The SARs of tested compounds suggested that the length of the side chain and the substituents on the amide nitrogen are important for pure antagonistic activities.

CH4892280 and others were synthesized and showed AR antagonistic activities without agonistic activities in reporter gene assay. SARs of the compounds are also presented in this report.Figure optionsDownload as PowerPoint slide