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


1 Young Researcher Club, Mashhad Branch, Islamic Azad University, Mashhad, Iran

2 Department of Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, Iran


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), HOMOLUMO
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 π-like frontier orbital
(HOMO and LUMO) delocalized through the whole molecule (Table 3) corroborate that Trolox and substituted Trolox could
be a reactive systems.