Dietary chromones as antioxidant agents--the structural variable.

This study reports an evaluation of the free radical scavenging ability of a series of chromone derivatives, in the light of their structural features and conformational behaviour. The 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) test for the assessment of radical scavenging properties was applied, and the interpretation of the experimental results was assisted by ab initio theoretical approaches that allowed relevant parameters, such as the enthalpy of formation of the radical species, to be predicted. From the eighteen tested compounds, three-fisetin, luteolin and quercetin-are shown to act as effective antiradicals. Consistent structure-activity relationships (SARs) were established regarding the antioxidant role of this type of chromone-based system.