Constituents of the seeds of Cassia tora with inhibitory activity on soluble expoxide hydrolease.

Efforts to extract soluble epoxide hydrolase (sEH) inhibitors from food sources through bioactivity-guided fractionation of Cassia tora seed extracts led to the isolation of one new compound, 1, and 15 known compounds, 2-16. Structural elucidations were performed using 1D/2D NMR spectroscopy and mass spectrometry. Compounds 1, 3, 4, 6, 10, 11, and 13-16 exhibited inhibitory activities on sEH with IC50 values of 2.2±2.1-40.6±3.4 μM. Compound 13 was particularly active and exhibited a reversible-uncompetitive behavior in enzyme kinetic studies. A binding site on the enzyme for compound 13 was also predicted by Autodock 4.2 simulations.