Phenolic acids

Phenolic acids, members of plant polyphenols, are one of the most common secondary metabolites in plants. They can be mainly divided into two groups: (1) hydroxybenzoic acid derivatives and (2) hydroxycinnamic acid derivatives. Phenolic acids are reported to have various health beneficial effects including potent antioxidant activities. The number of free hydroxyl groups is one of the main determining factors for their antioxidant activities. Many phenolic acids are also reported to exhibit pro-oxidant activity through their phenoxy radicals which can be both beneficial and harmful to human body depending upon various factors.