Synthesis of Hydroxy Derivatives of Highly Potent Non-steroidal CYP 17 Inhibitors as Potential Metabolites and Evaluation of their Activity by a Non Cellular Assay using Recombinant Human Enzyme

Inhibition of CYP 17 is a promising strategy for the treatment of prostate cancer. Recently two non-steroidal compounds with high in vitro activity were synthesized in our group (BW19 and BW95). However, after a few hours they showed in vivo a strong decrease in their activity. This might be due to a fast biodegradation. Potential hydroxy and epoxy metabolites were synthesized and their inhibitory activities were tested by a new non-cellular assay using recombinant enzyme. As source, membrane fractions of E. coli pJL17/OR coexpressing human CYP 17 and rat NADPH-P450-reductase were, used. Showing a high and constant CYP 17 activity and a fast and easy isolation procedure the new method was advantageous compared with the microsomal assay. Interestingly, all the new synthesized hydroxy and epoxy compounds except one showed a lower inhibition of CYP 17 than the parent compounds. Thus, the loss of in vivo activity may be partly explained.