NADPH-dependent alpha,beta-unsaturated oxoene reductase reducing the double bond of medium-chain (C9) to long-chain (C18) reactive electrophile species deriving from poly-unsaturated fatty acid peroxides. The best substrates are 13-lipoxygenase-derived gamma-ketols, but is unable to reduce the double bond of short-chain alkenals and alkenones such as acrolein, crotonaldehyde, 3-buten-2-one, 4-hexen-3-one and trans-2-hexenal, or quinones such as duroquinone, decylubiquinone, coenzyme Q0, menadione, menaquinone and phylloquinone. Can use trans-2-nonenal, trans-3-decen-2-one, 4-hydroxynonenal, 12-oxo-10(E) dodecanoate (traumatin), 4-oxononenal, trans-1,3 diphenyl-2-propenone, trans-1,4-diphenyl-2-butene-1,4-dione, 9-oxo-12,13-epoxy-(10E)-octadecenoic acid (trans-EKODE-1b), 9-hydroxy-12-oxo-10(E)-octadecenoic acid, 9-Hydroxy-12-oxo-10(E),15(Z)-octadecadienoic acid and 9,13-dihydroxy-10-oxo-11-octadecenoic acid as substrates, but has no activity with 13(R,S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid (13-HPOD), 9(S),12(S),13(S)-trihydroxy-10(E)-octadecenoic acid, 13-hydroxy-12-oxo-9(Z)-octadecenoic acid, 9-oxo-10(E),12(Z)-octadecadienoic acid (9-KODE), 13-oxo-9(Z),11(E)-octadecadienoic acid (13-KODE) and 12-oxo-10,15(Z)-phytodienoic acid (12-OPDA).
