Structure–antioxidant activity (oxygen radical absorbance capacity) relationships of phenolic compounds

Antioxidant capacity is the extent to which a compound can eliminate reactive oxygen species, and in vitro methods for its chemical evaluation have been proposed. Among these methods, radical absorbance (ORAC) assay comes close oxidation reaction living body because it generates species that mimic lipid peroxyl involved peroxidation of biological components react phosphate buffer. In this study, PM7, semi-empirical molecular orbital method, was used calculate thermodynamic properties (bond dissociation enthalpy, ionisation potential proton affinity) associated with ORAC. We also applied clusterwise linear regression analysis as statistical method grouping antioxidants by structure. By analysing data antioxidants, trend hydrophilic ORAC values determined using calculated structures bond enthalpies groups classified according presence or absence functional ortho position phenol. Further studies indicators other than enthalpy are needed predict such flavonoids indoles.