Alkylresorcinols as antioxidants: hydrogen donation and peroxyl radical-scavenging effects

Alkrylresorcinols, resorcinol derivatives with a long hydrocarbon chain at position 5 of the phenolic ring, have been reported to act as antioxidants and protect polyunsaturated fatty acids against peroxidation. Their structu res with meta-dihydroxy substitutions do not, however, support active hydro gen donation and scavenging of peroxyl radicals responsible for propagation of lipid oxidation. This study compares the antioxidant properties of 5-n- pentadecylresorcinol and alpha -tocopherol using two model systems: (i) the DPPH. model to test their ability for hydrogen atom donation; and (ii) a t riacylglycerol oxidation model to test their ability for scavenging peroxyl radicals. In agreement with theoretical expectations, results from both mo dels showed 5-n-pentadecylresorcinol to have very low hydrogen donation and peroxyl radical-scavenging potency. (C) 2000 Society of Chemical Industry.