Vanillic acid is a phenolic acid found in some forms of vanilla and many other plant extracts. It is a flavouring and scent agent that produces a pleasant, creamy odour. It is the intermediate product in the two-step bioconversion of ferulic acid to vanillin (J Biotechnol 1996;50(2-3):107-13). Vanillic acid, which is a chlorogenic acid, is an oxidized form of vanillin. It is also an intermediate in the production of vanillin from ferulic acid. Vanillic acid is a metabolic byproduct of caffeic acid and is often found in the urine of humans who have consumed coffee, chocolate, tea, and vanilla-flavoured confectionary. Vanillic acid selectively and specifically inhibits 5'nucleotidase activity. Vanillic acid is a microbial metabolite found in Amycolatopsis, Delftia, and Pseudomonas. Vanillin is toxic to the cells and hence it is subject to catabolism caused by the oxidative activity of this protein. This is undesired from the production point of view of this important compound. The deletion mutant of this protein can be used in production of natural vanillin by microbial fermentation from ferulic acid at final concentrations and molar yields on an industrial scale. The enzyme vanillin dehydrogenase in Amycolatopsis species catalyzes NAD+-dependent oxidation of vanillin to vanillate. Oxidates also other aromatic aldehydes including benzaldehyde, coniferyl aldehyde and cinnamaldehyde, but has a preference for vanillin. Vanillin is produced via the breakdown of phenylalanine.

Metabolism and Physiological Effects of Vanillic Acid References