A DFT Study on Antioxidant Activity of Trolox and Substituted Trolox and Their Radicals

Density functional theory (dft) at b3lyp/6-311g* level was employed to calculate antioxidant activity for trolox[(+)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid] and substituted trolox. bond dissociation energy (bde), homo-lumo gap energy, o-h charge differences and o-h bond lengths were calculated. the results are shown that the bde values of substituated trolox range from about 74 to 79 kcal/mol, demonstrating that trolox is an effective chain-breaking antioxidant that prevents lipid peroxidation. also the small value of gap and the distribution of ?-like frontier orbital (homo and lumo) delocalized through the whole molecule (table 3) corroborate that trolox and substituted trolox could be a reactive systems.