Homogentisic acid

{{Use dmy dates|date=August 2021}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 443859706

| ImageFile=Homogentisic acid.svg

| ImageFile1 = Homogentisic Acid 3D balls.png

| PIN=(2,5-Dihydroxyphenyl)acetic acid

| OtherNames=Melanic acid

|Section1={{Chembox Identifiers

| KEGG_Ref = {{keggcite|correct|kegg}}

| KEGG = C00544

| InChI = 1/C8H8O4/c9-6-1-2-7(10)5(3-6)4-8(11)12/h1-3,9-10H,4H2,(H,11,12)

| InChIKey = IGMNYECMUMZDDF-UHFFFAOYAK

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C8H8O4/c9-6-1-2-7(10)5(3-6)4-8(11)12/h1-3,9-10H,4H2,(H,11,12)

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = IGMNYECMUMZDDF-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|??}}

| CASNo=451-13-8

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = NP8UE6VF08

| PubChem=780

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 759

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| DrugBank = DB08327

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 44747

| SMILES = O=C(O)Cc1cc(O)ccc1O

| MeSHName=Homogentisic+acid

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|Section2={{Chembox Properties

| C=8 | H=8 | O=4

| Appearance=

| Density=

| MeltingPtC=150 to 152

| BoilingPt=

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|Section3={{Chembox Hazards

| MainHazards=

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Homogentisic acid (2,5-dihydroxyphenylacetic acid) is a phenolic acid usually found in Arbutus unedo (strawberry-tree) honey.{{cite journal | title = Homogentisic Acid: A Phenolic Acid as a Marker of Strawberry-Tree (Arbutus unedo) Honey |author1=Paolo Cabras |author2=Alberto Angioni |author3=Carlo Tuberoso |author4=Ignazio Floris |author5=Fabiano Reniero |author6=Claude Guillou |author7=Stefano Ghelli | journal = J. Agric. Food Chem. | year = 1999 | volume = 47 | issue = 10 | pages = 4064–4067 | doi = 10.1021/jf990141o|pmid=10552766 |bibcode=1999JAFC...47.4064C }} It is also present in the bacterial plant pathogen Xanthomonas campestris pv. phaseoli{{cite journal | url = http://cat.inist.fr/?aModele=afficheN&cpsidt=3978055 | title = Brown pigmentation of Xanthomonas campestris pv. phaseoli associated with homogentisic acid | vauthors = Goodwin PH, Sopher CR | journal = Canadian Journal of Microbiology | volume = 40 | issue = 1 | pages = 28–34 | year = 1994 | doi = 10.1139/m94-005 | access-date = 25 February 2011 | archive-date = 21 July 2011 | archive-url = https://web.archive.org/web/20110721001238/http://cat.inist.fr/?aModele=afficheN&cpsidt=3978055 | url-status = dead| url-access = subscription }} as well as in the yeast Yarrowia lipolytica{{cite journal | title = Brown Pigments Produced by Yarrowia lipolytica Result from Extracellular Accumulation of Homogentisic Acid |author1=Alexandra Carreira |author2=Luísa M. Ferreira |author3=Virgílio Loureiro | journal = Appl Environ Microbiol | year = 2001 | volume = 67 | issue = 8 | pages = 3463–3468 | doi = 10.1128/AEM.67.8.3463-3468.2001|pmid=11472920 |pmc=93044 |bibcode=2001ApEnM..67.3463C |citeseerx=10.1.1.319.523 }} 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.