Effects of Phenolic Compounds on Reactions Involving Various Organic Radicals

Abstract

Investigation of effects produced by 26 various phenol and diphenol derivatives, including industrial and natural antioxidants (ionol, bis-phenol 2246, alpha-tocopherol), on final product yields of radiation-induced free-radical processes involving peroxyl, alkyl, alpha-hydroxyalkyl and alpha,beta-dihydroxyalkyl radicals has been performed. Ionol and bis-phenol 2246 have been shown to be more effective than alpha-tocopherol or diphenol derivatives in suppressing hydrocarbon oxidation processes. At the same time, alpha-tocopherol and its water-soluble analogues, as well as diphenol-based substances, are more effective than phenol derivatives in regulating various homolytic processes involving carbon-centered radicals. This fact can be accounted for by taking into consideration the contribution to formation of the final product set and the respective yields made by semiquinone radicals and compounds with quinoid structure arising in the course of homolytic transformations in systems containing diphenol derivatives.

Intramolecular and intermolecular hydrogen bonds in aminophenols

“…Derivatives of phenols and aromatic amines are effective antioxidants and, therefore, are used widely as stabilizers of industrial organic materials and food preservatives [1,2]. Certain derivatives of diphenols [3,4] and aminophenols (AP) [5, 6] turned out to be effective regulators of radiation-induced reactions involving various types of organic radicals. It was found that the antioxidant properties of AP derivatives are diminished upon forming intramolecular hydrogen bonds (IHB) in solution and are enhanced when the hydroxyls in the molecules occur in the free state [7].…”

Effect of the B Vitamins on the Radiolysis of Aqueous Ethanol and Ethylene Glycol Solutions

“…The facts given below should be taken into account in the consideration of the conceivable reaction routes of this interaction. In studies of the radiation-induced reactions of CHOH species with phenolic compounds [14] and aminophenols [10,15], it was found that alcohol radicals can be reduced via the reaction…”

Intramolecular hydrogen bonds and antioxidant activity of aminophenols

“…Today, derivatives of aminophenols are widely used as antiviral drugs for treatment of herpes infection [5][6][7]. Furthermore, some derivatives of diphenols [8,9] and aminophenols [10,11] have proven to be effective regulators of radiationinduced reactions involving participation of different types of organic radicals. One factor affecting the radical-inhibition activity of aminophenols may be the ability of the phenol hydroxyl to engage in intramolecular hydrogen bonds [12,13].…”