research Synthesis and in vitro study of 17β-[N-ureylene-N,N′-disubstituted]-4-methyl-4-aza-5α-androstan-3-ones as selective inhibitors of type I 5α-reductase
This study found that among 17 beta-(N-ureylene-N,N'-disubstituted)-4-azasteroids, those with an N'-phenyl moiety were the most effective inhibitors of human type I 5 alpha-reductase.
