A metabolite in the pathway for the conversion of phenylalanine and tyrosine to fumarate and acetoacetate.
An acid present in urine in alkaptonuria, a rare metabolic disease.
A product formed during the metabolism of the amino acids phenylalanine and tyrosine. In normal individuals homogentisic acid is oxidized by the enzyme homogentisic acid oxidase. In rare cases this enzyme is lacking and a condition known as alcaptonuria, in which large amounts of homogentisic acid are excreted in the urine, results.
An intermediate product of tyrosine catabolism; found in the urine in alkaptonuria.