Metal complexes as radical initiators inducing Antioxidant/prooxidant activity of phenols/polyphenols of food, and their evaluation as anticancer agents

Abstract

Phenolics are activated by VV and/or VIV coordinated catalytic sites in the lipophilic matrix of oil mediated by dioxygen activation; in this oxidative environment free radicals are trapped by -tocopherol to give -tocopheryl radicals monitored by X-band cw-EPR vs time providing very useful quantification tool for the determination of the ability of the complexes to initiate radicals1.The possibility to quantify α-Tocopherol in extra virgin olive oils by EPR spectroscopy has been investigated using vanadium (V) lipophilic metal complexes as radical initiators1. The experimental results showed that there is a relationship between the intensity of the signal of the α-Tocopheryl radical in the EPR spectrum and the concentration of α-Tocopherol contained, upon addition in food samples The α-Tocopherol concentration values determined for the olive oils were validated by comparison with those determined by the 19F NMR method2. The metal-based radical initiators have also been applied for the investigation of the phenol/polyphenol content conducted through spin trapping on -tocopheryl radicals, whereas, parameters associated to the nature of the phenolic compound and their prooxidant/antioxidant activity are determined through the kinetics of the radical initiation through O2 activation reactions. Anticancer properties of these complexes are evaluated.

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