The Phenolic Acids of Human Urine*

In the course of an investigation of the metabolism of aromatic compounds in phenylketonuria, it was found that, along with the abnormal metabolism of phenylalanine in this disease, there are other striking deviations from normal. These are manifested by the excretion of greatly increased amounts of some indole acids (1) and phenolic acids (2,3) which are present in normal human urine in small quantities. In order to gain a clearer understanding of the deranged metabolism of aromatic compounds in phenylketonuria and in other disorders, it became necessary to examine the phenolic constituents of normal human urine. Some procedures already have been reported for the chromatographic characterization of various phenolic acids (4-Q). The compounds for which detailed information has been reported are few in number, and there has been no systematic investigation of the simple compounds which might be expected to occur in urine. The purpose of this paper is to report a description of the phenolic acids of human urine. A combination of solvent systems which is suitable for the separation of forty-nine authentic aromatic acids by two-dimensional paper chromatography has been developed.