REDUCTION OF 13-HYDROPEROXY-9,11-OCTADECADIENOIC ACID BY DOPAMINE-MELANIN

The effect of dopamine-melanin (DA-melanin), synthetic model of neurom elanin, on the stability of 13-hydroperoxyoctadecadienoic acid (13-HPO DE) has been investigated using a reverse-phase high-performance liqui d chromatography (HPLC) with UV detection. It was found that DA-melani n effectively accelerated the decomposition of 13-HPODE, both in the a bsence and in the presence of ferrous ions. The disappearance of 13-HP ODE was accompanied by the formation of 13-hydroxyoctadecadienoic acid (13-HODE). The results obtained indicate that DA-melanin is able to r educe linoleic acid hydroperoxide to its stable hydroxyl derivative. T he fatty acid hydroperoxide-reducing ability of DA-melanin appears to play an important role in the antioxidative activity of neuromelanin i n the process of lipid peroxidation. (C) 1998 Academic Press.