3D model (JSmol)
CompTox Dashboard (EPA)
|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).
|what is ?)(|
Homogentisic acid (2,5-dihydroxyphenylacetic acid) is a phenolic acid usually found in Arbutus unedo (strawberry-tree) honey. It is also present in the bacterial plant pathogen Xanthomonas campestris pv. phaseoli as well as in the yeast Yarrowia lipolytica 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.
It is less commonly known as melanic acid, the name chosen by William Prout.
Accumulation 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.
It is an intermediate in the catabolism of aromatic amino acids such as phenylalanine and tyrosine.
p-Hydroxyphenyl pyruvate (produced by transamination of tyrosine) is acted upon by the enzyme p-hydroxyphenyl pyruvate oxidase to yield homogentisate. It is then degraded by the enzyme homogentisate oxidase to give maleyl-acetoacetate.