Antioxidant and prooxidant activities of phenolic acids commonly existed in vegetables and their relationship with structures

Phenolic acids existed in many agricultural products especially vegetables and considered as important natural antioxidants. Eleven phenolic commonly were chosen to assess the antioxidant activities using DPPH·, ·ABTS+, ·O2-, ·OH scavenging assays, well ferric reducing power ?-carotene bleaching assays. The results showed that caffeic protocatechuic acid with simple dihydroxylation structures have best activities, while p-Hydroxybenzoic p-Coumaric mono hydroxylation lowest most activity of was higher than ferulic isoferulic may be due substituents position on benzene ring. Antioxidant caftaric, chicoric chlorogenic its derivates complex high relatively among acids. different concentration ranges obtained based quantitative relationship between or prooxidant sample concentrations. effect rarely observed present study. conducive further research potential biological vegetables.