Vanillic acid is a dihydroxybenzoic acid that can be used as a flavoring agent. As an oxidized form of vanillin, it is the intermediate product during the two-step bioconversion process from ferulic acid to vanillin. It exists in high amount in the root of Angelica sinenisis, which is a plant used in traditional Chinese medicine. It also exists in acal oil, argan oil as well as wine and vinegar. It can be used in the synthesis of the analeptic drug etamivan, modecainide, brovanexine, vanitiolide, and vanyldisulfamide. It can be manufactured through the oxidation of vanillin to the carboxylic acid.
