Characterization of novel imidazole derivative, JM-8686, a potent inhibitor of allene oxide synthase

The inhibitory properties of a first synthetic jasmonic acid biosynthesis inhibitor, JM-8686, were investigated. Steady-state kinetic analysis indicates that the compound is a competitive inhibitor of allene oxide synthase (AOS) with a Ki value of approximate 0.62 ± 0.15 μM. Dialysis experiment indicates that AOS inactivation by JM-8686 is reversible. The optical difference spectroscopy analysis of JM-8686 and AOS interaction indicates that JM-8686 induced type II binding spectra with a Kd value of approximate 1.6 ± 0.2 μM, suggesting that JM-8686 binds to the prosthetic heme iron of AOS. Comparison of the inhibitory potency of the compound against HPL (CYP74B) from tomato revealed that JM-8686 was a highly selective inhibitor for AOS.