Also called trihydroxybenzoic acid is contained in many products of plant origin and has antioxidant action. Gallic acid is produced by the plant to combat cell proliferation. It is common in woody plant species and besides being in leaves and roots it is also found in seeds and fruits like olives (in fact it is a polyphenol contained in olive oil). It is also found in blackberries, raspberries, strawberries and mangoes.