homogentisic acid(redirected from Melanic acid)
Also found in: Dictionary, Thesaurus, Encyclopedia.
ho·mo·gen·tis·ic ac·id(hō'mō-jen-tis'ik as'id),
Glycosuric acid; (2,5-dihydroxyphenyl)acetic acid; an intermediate in l-phenylalanine and l-tyrosine catabolism; if made alkaline, it oxidizes rapidly in air to a quinone that polymerizes to a melaninlike material; elevated levels are observed in patients with alcaptonuria.
An intermediate of the metabolic breakdown of tyrosine and phenylalanine; it occurs in the urine in cases of alkaptonuria.