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 individuals having alcaptonuria. SYN: alcapton, alkapton.
- h. oxidase SYN: homogentisate 1,2-dioxygenase.
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ho·mo·gen·tis·ic acid .hō-mō-.jen-'tiz-ik, .häm-ō- n a crystalline acid C8H8O4 formed as an intermediate in the metabolism of phenylalanine and tyrosine and found esp. in the urine of those affected with alkaptonuria
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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.
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ho·mo·gen·tis·ic ac·id (ho″mo-jen-tisґik) an aromatic hydrocarbon formed as an intermediate in the catabolism of tyrosine and phenylalanine. It is accumulated abnormally and excreted in the urine in alkaptonuria.Medical dictionary. 2011.