(±)8,9-DiHETE is a major metabolite of the 20:5 ω-3 fatty acid eicosapentaenoic acid .[1] It is produced in rat liver microsomes, but not renal microsomes, by the generation of the unstable intermediate 8,9-epoxy eicosatetraenoic acid from EPA by cytochrome P450 monooxygenases. Dietary EPA supplementation in humans results in substantial urinary excretion of vicinal diols, including 8,9, 11,12, and 14,15 forms.[2]
Reference：
[1]. VanRollins, M., Frade, P.D., and Carretero, O.A. Oxidation of 5,8,11,14,17-eicosapentaenoic acid by hepatic and renal microsomes. Biochimica et Biophysica Acta 996, 133-149 (1988).
[2]. Knapp, H.R., Miller, A.J., and Lawson, J.A. Urinary excretion of diols derived from eicosapentaenoic acid during N-3 fatty acid ingestion. Prostaglandins 42(1), 47-53 (1991).