Gallic acid is an organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C₆H₂(OH)₃CO₂H. Gallic acid is found both free and as part of tannins.it is commonly used in the pharmaceutical industry

The COOH group has a pKa of 4.5, and the phenolic OHs have pKa of 10.

Salts and esters of gallic acid are termed gallates.

External link

• King's American Dispensatory (1898) entry on Gallic acid

Carboxylic acids | Phenols

Gallussäure | Galluszuur | 没食子酸 | kwas galusowy