Homogentisic Acid

Homogentisic acid is a substance that accumulates in the hereditary disease, alkaptonuria, due to a deficiency of the enzyme homogentisic acid dioxygenase. In the disease, homogentisic acid is excreted in large amounts in the urine where it oxidizes on standing, causing the urine to become dark.

See also: Aromatic Amino Acid Utilization, Metabolism of Aromatic Amino Acids and Histidine, Neurotransmitters and Biological Regulators