Homogentisic acid (2,5-dihydroxyphenylacetic acid) is a phenolic acid usually found in Arbutus unedo (strawberry-tree) honey.[1] It is also present in the bacterial plant pathogen Xanthomonas campestris pv. phaseoli[2] as well as in the yeast Yarrowia lipolytica[3] where it is associated with the production of brown pigments. It is oxidatively dimerised to form hipposudoric acid, one of the main constituents of the 'blood sweat' of hippopotamuses.
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| Names | |
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| Preferred IUPAC name
(2,5-Dihydroxyphenyl)acetic acid | |
| Other names
Melanic acid
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| Identifiers | |
3D model (JSmol)
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| DrugBank | |
| ECHA InfoCard | 100.006.540 |
| KEGG | |
| MeSH | Homogentisic+acid |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C8H8O4 | |
| Molar mass | 168.148 g·mol−1 |
| Melting point | 150 to 152 °C (302 to 306 °F; 423 to 425 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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It is less commonly known as melanic acid, the name chosen by William Prout.
Human pathology
editAccumulation of excess homogentisic acid and its oxide, named alkapton, is a result of the failure of the enzyme homogentisic acid 1,2-dioxygenase (typically due to a mutation) in the degradative pathway of tyrosine, consequently associated with alkaptonuria.[4]
Intermediate
editIt is an intermediate in the catabolism of aromatic amino acids such as phenylalanine and tyrosine.
4-Hydroxyphenylpyruvate (produced by transamination of tyrosine) is acted upon by the enzyme 4-hydroxyphenylpyruvate dioxygenase to yield homogentisate.[5] If active and present, the enzyme homogentisate 1,2-dioxygenase further degrades homogentisic acid to yield 4-maleylacetoacetic acid.[6]
References
edit- ^ Paolo Cabras; Alberto Angioni; Carlo Tuberoso; Ignazio Floris; Fabiano Reniero; Claude Guillou; Stefano Ghelli (1999). "Homogentisic Acid: A Phenolic Acid as a Marker of Strawberry-Tree (Arbutus unedo) Honey". J. Agric. Food Chem. 47 (10): 4064–4067. doi:10.1021/jf990141o. PMID 10552766.
- ^ Goodwin PH, Sopher CR (1994). "Brown pigmentation of Xanthomonas campestris pv. phaseoli associated with homogentisic acid". Canadian Journal of Microbiology. 40 (1): 28–34. doi:10.1139/m94-005. Archived from the original on 21 July 2011. Retrieved 25 February 2011.
- ^ Alexandra Carreira; Luísa M. Ferreira; Virgílio Loureiro (2001). "Brown Pigments Produced by Yarrowia lipolytica Result from Extracellular Accumulation of Homogentisic Acid". Appl Environ Microbiol. 67 (8): 3463–3468. CiteSeerX 10.1.1.319.523. doi:10.1128/AEM.67.8.3463-3468.2001. PMC 93044. PMID 11472920.
- ^ Phornphutkul C, Introne WJ, Perry MB, et al. (2002). "Natural history of alkaptonuria". New England Journal of Medicine. 347 (26): 2111–21. doi:10.1056/NEJMoa021736. PMID 12501223.
- ^ Lindstedt, Sven; Odelhog, Birgit; Rundgren, Marianne (1977). "Purification and Some Properties of 4-Hydroxyphenylpyruvate Dioxygenase from Pseudomonas sp. P.J. 814". Biochemistry. 16 (15): 3369–3377. doi:10.1021/bi00634a013.
- ^ Knox WE, LeMay-Knox M (October 1951). "The oxidation in liver of l-tyrosine to acetoacetate through p-hydroxyphenylpyruvate and homogentisic acid". The Biochemical Journal. 49 (5): 686–93. doi:10.1042/bj0490686. PMC 1197578. PMID 14886367.