Inhibitory Activity of Flavonoids, Chrysoeriol and Luteolin-7--Glucopyranoside, on Soluble Epoxide Hydrolase from Capsicum chinense.

Three flavonoids derived from the leaves of Jacq. were identified as chrysoeriol (1), luteolin-7--glucopyranoside (), and isorhamnetin-7--glucopyranoside (). They had IC 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 K 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, and , could be complexed with sEH by the "induced fit" and "lock-and-key" models.