It has been shown that a cobalt porphyrin, CoTPPCl (TPP = tetraphenylporphyrin), can initiate the autoxidative radical-chain peroxidation of polyunsaturated fatty acids and esters (LH: linoleic acid, methyl linoleate, and linolenic acid) in an oxygen-saturated MeCN solution at 333 K by the direct interaction between CoTPPCl and LH, i.e., the one-electron reduction of CoTPPCl by LH, based on independent kinetic studies on the initiation step in deaerated MeCN and the overall CoTPP+-catalysed peroxidation of LH by dioxygen. The CoTPP+ complex can function not only as an initiator but also a catalyst, as demonstrated by independent kinetic studies on the catalyst regeneration step, the oxidation of CoTPP by dioxygen in the presence of LH. In addition, the cobalt(II) porphyrin complex, CoTPP, acts as a radical scavenger by the one-electron reduction of the chain carrier radicals, lipid peroxyl radicals.
|Number of pages||5|
|Journal||Journal of the Chemical Society. Perkin Transactions 2|
|State||Published - 1989|