Molecular oxygen rapidly adds to the carbon-centered radicals (R.
) formed in this process,
yielding lipid peroxyl radicals (ROO.
). Decomposition of lipid peroxides is catalyzed by
transition metal complexes yielding alcoxyl (RO.
) or hydroxyl (HO.
) radicals. These
participate in chain reaction initiation that in turn abstract hydrogen and perpetuate the
chain reaction of lipid peroxidation. The formation of peroxyl radicals leads to the production
of organic hydroperoxides, which, in turn, can subtract hydrogen from another PUFA. This
reaction is termed propagation, implying that one initiating hit can result in the conversion of
numerous PUFA to lipid hydroperoxides. In sequence of their appearance, alkyl, peroxyl and
alkoxyl radicals are involved. The resulting fatty acid radical is stabilized by rearrangement
into a conjugated diene that retains the more stable products including hydroperoxides,
alcohols, aldehydes and alkanes. Lipid hydroperoxide (ROOH) is the first, comparatively
stable, product of the lipid peroxidation reaction