Homogentisic Acid(redirected from Melanic acid)
Also found in: Dictionary, Thesaurus, Medical.
homogentisic acid[¦hä·mə‚jen¦tiz·ik ′as·əd]
an intermediate product of the decomposition of the cyclic amino acids phenylalanine and tyrosine in the animal or human body. In the hereditary disease alkaptonuria, which is expressed in a disturbance of the metabolism of these amino acids, the process stops at the stage of homogentisic acid formation because of an absence of homogentisic acid oxidase, and homogentisic acid is discharged with the urine.