Abstract
P450 are enzymes involved in phytohormone biosynthesis. Several azole type inhibitors have been reported that they targeting the P450 enzymes of gibberellin, brassinosteroid and/or jasmonic acid biosynthesis. It is generally known that azole derivatives exhibit inhibitory activities against P450, apparently due to the intrinsic affinity of the nitrogen electron pair in heterocyclic molecules for the prosthetic heme iron. In this context, we carried out searching for novel phytohormone biosynthesis inhibitors based on the chemical structure of ketoconazole as a molecular scaffold. The biological activities of synthesized compounds were evaluated by determining their inhibitory activity against CYP74A, a key enzyme in jasmonic acid biosynthesis, as well as in assays for brassinosteroid and gibberellin biosynthesis inhibitor using Arabidopsis seedlings grown in the darkness. We found several newly synthesized triazole derivatives exhibit potent inhibitory activity against brassinosteroid biosynthesis.
