Antioxidative activity of phenolic compounds on the metal-ion breakdown of lipid peroxidation system

The generation of a lipid alkoxyl (LȮ) radical as a result of metal-ion breakdown of hydroperoxide-enriched methyl linoleate of sunflower oil has been established by a combination of spin trapping and electron spin resonance (ESR) spectroscopy. Antioxidative activities of gallic, caffeic, chlorogenic, vanillic and salicylic acids at concentrations of 0.5, 1.0 and 2.0 mmol were studied in a lipid peroxidation system. The results show that the investigated phenolic compounds scavenge alkoxyl radical. This activity depends on the structure of the molecules, and number and position of the hydroxyl group in the molecules; it is increased in the order gallic > caffeic >> chlorogenic > vanillic > salicylic acids.