Gentisic acid

Gentisic acid
Names
	Preferred IUPAC name 2,5-Dihydroxybenzoic acid
	Other names DHB; 5-Hydroxysalicylic acid; Gentianic acid; Carboxyhydroquinone; 2,5-Dioxybenzoic Acid; Hydroquinonecarboxylic acid;
Identifiers
CAS Number	490-79-9 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:17189 ;
ChEMBL	ChEMBL1461 ;
ChemSpider	3350 ;
ECHA InfoCard	100.007.017
KEGG	C00628 ;
PubChem CID	3469;
UNII	VP36V95O3T ;
CompTox Dashboard (EPA)	DTXSID4060078 ;
	InChI InChI=1S/C7H6O4/c8-4-1-2-6(9)5(3-4)7(10)11/h1-3,8-9H,(H,10,11) Key: WXTMDXOMEHJXQO-UHFFFAOYSA-N ;
	SMILES O=C(O)c1cc(O)ccc1O;
Properties
Chemical formula	C7H6O4
Molar mass	154.121 g·mol−1
Appearance	white to yellow powder
Melting point	204 °C (399 °F; 477 K)
Solubility in water	very soluble
Solubility in ethanol	very soluble
Solubility in diethyl ether	very soluble
Solubility in acetone	soluble
Acidity (pKa)	2.97
Related compounds
Related compounds	2,3-Dihydroxybenzoic acid; 2,4-Dihydroxybenzoic acid; 2,6-Dihydroxybenzoic acid; 3,4-Dihydroxybenzoic acid; 3,5-Dihydroxybenzoic acid;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Gentisic acid is a dihydroxybenzoic acid. It is a derivative of benzoic acid and a minor (1%) product of the metabolic break down of aspirin, excreted by the kidneys.

It is also found in the African tree Alchornea cordifolia and in wine.