On the occurence of vanillic acid in human brain and cerebrospinal fluid.

3-methoxy-4-hydroxyphenylbenzoic (vanillic) acid was previously shown to be one of the endogenous metabolites of adrenaline and noradrenaline. Using thin-layer chromatographic methods for identification and quantification of phenolic acids and phenolic alcohols, the authors identified vanillic acid in different regions of the human brain. The concentration of vanillic acid in the cerebrospinal fluid was also determined and compared to the concentration of 3-methoxy-4-hydroxyphenylethylene glycol. The identification of VA in the human brain suggests that the vanillic acid of the cerebrospinal fluid originates, at least in part, from the catecholamines in the brain. The authors discuss other possible origins of vanillic acid besides the noradrenaline catabolism of dopamine. As the concentration of vanillic acid in the cerebrospinal fluid was found to be greater than the concentration of 3-methoxy-4-hydroxyphenylethylene glycol, it might be important for clinical biological studies to measure vanillic acid in the cerebrospinal fluid as well as the other alcoholic and acid catabolites of the catecholamines.