4-Oxo-2-nonenal as a pro-oxidant during the autoxidation of methyl linoleate in bulk phase

The effect of aldehydic lipid peroxidation products on the autoxidation of methyl linoleate (MeL) was studied at 60 °C in bulk phase. Addition of 4-oxo-2-nonenal (ONE) to MeL accelerated the formation of MeL hydroperoxides. Other tested aldehydes showed no effect on the rate of MeL autoxidation. The pro-oxidative effect of ONE disappeared when pre-existing peroxides and transition metals were removed from MeL. Further addition of ferric ion to the peroxide- and metal-free MeL recovered its pro-oxidative effect. ONE reduced ferric ion to ferrous ion effectively. Furthermore, it had a chelating ability with ferrous ion. The results suggest that the pro-oxidative effect of ONE is due to its ability to reduce transition metals and to chelate the reduced form of metal ions. Thus, ONE could accelerate the metal-dependent lipid peroxidation.