In this study, we investigated the in vitro effect of 16-formyl-17-methoxy dehydroepiandrosterone derivatives on the activity of 5α-reductase type 2 (5α-R2) obtained from human prostate. The activity of different concentrations of these derivatives was determined for the conversion of labelled testosterone to dihydrotestosterone. The results indicated that an aliphatic ester moiety at the C-3 position of these derivatives increases their in vitro potency as inhibitors of 5α-R2 activity compared to finasteride®, which is considered to be a potent inhibitor of 5α-R2. In this case, the augmentation of the lipophilicity of these dehydroepiandrosterone derivatives increased their potency as inhibitors of 5α-R2. However, the presence of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl rings as the cycloaliphatic ester moiety at C-3 of the formyl methoxy dehydroepiandrosterone scaffold did not inhibit the activity of this enzyme. This may be due to the presence of steric factors between the enzyme and the spatial structure of these derivatives.
Keywords: 16-formyl-17-methoxy dehydroepiandrosterone ester derivatives; 5α-Reductase inhibitors; 5α-reductase type 2; androgen receptor; prostate cancer.