Inhibitory activity of flavonoids, chrysoeriol and luteolin-7-o-glucopyranoside, on soluble epoxide hydrolase from Capsicum chinense

Abstract

Three flavonoids derived from the leaves of Capsicum chinense Jacq. were identified as chrysoeriol (1), luteolin-7-O-glucopyranoside (2), and isorhamnetin-7-O-glucopyranoside (3). They had IC50 values of 11.6±2.9, 14.4±1.5, and 42.7±3.5 μg/mL against soluble epoxide hydrolase (sEH), respectively. The three inhibitors (1–3) were found to non-competitively bind into the allosteric site of the enzyme with Ki values of 10.5±3.2, 11.9 ±2.8 and 38.0±4.1 μg/mL, respectively. The potential inhibitors 1 and 2 were located at the left edge ofa U‐tube shape that contained the enzyme active site. Additionally, we observed changes in several factors involved in the binding of these complexes under 300 K and 1 bar. Finally, it was confirmed that each inhibitor, 1 and 2, could be complexed with sEH by the “induced fit” and “lock-and-key” models.