Predicting the Activity of Phenolic Antioxidants: Theoretical Method, Analysis of Substituent Effects, and Application to Major Families of Antioxidants
Citations Over TimeTop 1% of 2001 papers
Abstract
A procedure based on density functional theory is used for the calculation of the gas-phase bond dissociation enthalpy (BDE) and ionization potential for molecules belonging to the class of phenolic antioxidants. We show that use of locally dense basis sets (LDBS) vs full basis sets gives very similar results for monosubstituted phenols, and that the LDBS procedure gives good agreement with the change in experimental BDE values for highly substituted phenols in benzene solvent. Procedures for estimating the O--H BDE based on group additivity rules are given and tested. Several interesting classes of phenolic antioxidants are studied with these methods, including commercial antioxidants used as food additives, compounds related to Vitamin E, flavonoids in tea, aminophenols, stilbenes related to resveratrol, and sterically hindered phenols. On the basis of these results we are able to interpret relative rates for the reaction of antioxidants with free radicals, including a comparison of both H-atom-transfer and single-electron-transfer mechanisms, and conclude that in most cases H-atom transfer will be dominant.
Related Papers
- → PS II inhibitory activity of 2,4-diamino-6-chloro-s-triazines with a chiral sec-butyl and/or .ALPHA.-methylbenzyl group.(1990)15 cited
- → Evaluation of the steric substituent effect by ΩS: reinvestigation of the reaction dependency of the steric substituent constant(2001)8 cited
- → The origin and nature of the π-electron steric effect(1977)2 cited
- → A STUDY ON THE ADDITIVITY OF SUBSTITUENT EFFECTS IN THE TRIPHENYLPHOSPHONIUM SYSTEM(1992)
- The generalized additivity,transformation theorem and the defect of additivity for fuzzy measures(2010)