Inhibition of epoxide hydrolase from human, monkey, bovine, rabbit and murine liver by trans-3-phenylglycidols

1. 1. trans-3-Phenylglycidols were potent inhibitors of cytosolic epoxide hydrolases in all species tested. 2. 2. The order of inhibitor potency varied from species to species but trans-3-(4-nitrophenyl)glycidols were always the most potent inhibitors tested for cytosolic epoxide hydrolase. 3. 3. The S,S-enantiomer was a more potent cytosolic epoxide hydrolase inhibitor than the R,R-enantiomer when a free hydroxyl group was present. However, (2R,3R)-1-benzoyloxy-2,3-epoxy-3-(4-nitrophenyl)propane was always a better inhibitor than the (2S,3S)-enantiomer. 4. 4. All microsomal epoxide hydrolases were poorly inhibited by the trans-3-phenylglycidols, and related compounds, tested. The best new microsomal epoxide hydrolase inhibitor tested was (1S,2S)-1-phenyl-propylene oxide which gave 18-63% inhibition, at 2 mM, depending on the species tested.