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Record Information
Created at2005-11-16 15:48:42 UTC
Updated at2020-11-24 22:12:09 UTC
NP-MRD IDNP0000017
Secondary Accession NumbersNone
Natural Product Identification
Common NameGentisic acid
DescriptionGentisic acid, also known as gentisate or 2,5-dioxybenzoate, belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups. A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions. Gentisic acid is an extremely weak basic (essentially neutral) compound (based on its pKa). Gentisic acid exists in all living organisms, ranging from bacteria to humans. Outside of the human body, Gentisic acid is found, on average, in the highest concentration within a few different foods, such as tarragons, common thymes, and common sages and in a lower concentration in lemon balms, parsley, and soy beans. Gentisic acid has also been detected, but not quantified in, several different foods, such as garden tomato (var.), Cocoa beans, spearmints, common pea, and carrots. This could make gentisic acid a potential biomarker for the consumption of these foods.
5-Hydroxysalicylic acidChEBI
Hydroquinonecarboxylic acidChEBI
2,5-Dihydroxybenzoic acidKegg
2,5-Dioxybenzoic acidHMDB
3,6-Dihydroxybenzoic acidHMDB
5-Hydroxy-salicylic acidHMDB
Gentisinic acidHMDB
2,5-Dihydroxybenzoic acid, monosodium saltHMDB
Lithium 2,5-dihydroxybenzoateHMDB
Gentisic acidChEBI
Hydroquinone carboxylic acid
Chemical FormulaC7H6O4
Average Molecular Weight154.121
Monoisotopic Molecular Weight154.026608673
IUPAC Name2,5-dihydroxybenzoic acid
Traditional Name2,5-dihydroxybenzoic acid
CAS Registry Number490-79-9
InChI Identifier
Spectrum TypeDescriptionView
1D NMR1H NMR SpectrumJSpectraViewer
1D NMR1H NMR SpectrumJSpectraViewer
1D NMR13C NMR SpectrumJSpectraViewer
2D NMR[1H,13C] 2D NMR SpectrumJSpectraViewer
Species of Origin
SpeciesAnimalia; Plantae
Chemical Taxonomy
Description Belongs to the class of organic compounds known as hydroxybenzoic acid derivatives. Hydroxybenzoic acid derivatives are compounds containing a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and a hydroxyl groups.
KingdomOrganic compounds
Super ClassBenzenoids
ClassBenzene and substituted derivatives
Sub ClassBenzoic acids and derivatives
Direct ParentHydroxybenzoic acid derivatives
Alternative Parents
  • Dihydroxybenzoic acid
  • Salicylic acid
  • Salicylic acid or derivatives
  • Hydroxybenzoic acid
  • Benzoic acid
  • Benzoyl
  • Hydroquinone
  • 1-hydroxy-2-unsubstituted benzenoid
  • Phenol
  • Vinylogous acid
  • Carboxylic acid derivative
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Organic oxygen compound
  • Hydrocarbon derivative
  • Organooxygen compound
  • Organic oxide
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors
Physical Properties
Experimental Properties
Melting Point199.5 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility5 mg/mL at 5 °CNot Available
LogP1.74SANGSTER (1994)
Predicted Properties
Water Solubility12.3 g/LALOGPS
pKa (Strongest Acidic)2.53ChemAxon
pKa (Strongest Basic)-5.9ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area77.76 ŲChemAxon
Rotatable Bond Count1ChemAxon
Refractivity37.28 m³·mol⁻¹ChemAxon
Polarizability13.78 ųChemAxon
Number of Rings1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
User Submitted Data
Not Available
DrugBank IDNot Available
Phenol Explorer Compound ID416
FoodDB IDFDB000844
KNApSAcK IDC00002648
Chemspider ID3350
KEGG Compound IDC00628
BioCyc IDCPD-633
BiGG IDNot Available
Wikipedia LinkGentisic_acid
PubChem Compound3469
PDB IDNot Available
ChEBI ID17189
General References
  1. Ohsako M, Matsumoto Y, Goto S: Transport of aspirin and its metabolites through human erythrocyte membrane. Biol Pharm Bull. 1993 Feb;16(2):154-7. [PubMed:8364451 ]
  2. Almaas R, Rootwelt T, Oyasaeter S, Saugstad OD: Ascorbic acid enhances hydroxyl radical formation in iron-fortified infant cereals and infant formulas. Eur J Pediatr. 1997 Jun;156(6):488-92. [PubMed:9208249 ]
  3. Verhaeghe BJ, Lefevere MF, De Leenheer AP: Solid-phase extraction with strong anion-exchange columns for selective isolation and concentration of urinary organic acids. Clin Chem. 1988 Jun;34(6):1077-83. [PubMed:3378323 ]
  4. Palumbo G, Carlucci G, Mazzeo P, Frieri G, Pimpo MT, Fanini D: Simultaneous determination of 5-aminosalicylic acid, acetyl-5-aminosalicylic acid and 2,5-dihydroxybenzoic acid in endoscopic intestinal biopsy samples in humans by high-performance liquid chromatography with electrochemical detection. J Pharm Biomed Anal. 1995 Dec;14(1-2):175-80. [PubMed:8833980 ]
  5. Grootveld M, Halliwell B: Aromatic hydroxylation as a potential measure of hydroxyl-radical formation in vivo. Identification of hydroxylated derivatives of salicylate in human body fluids. Biochem J. 1986 Jul 15;237(2):499-504. [PubMed:3026319 ]
  6. Peleg H, Noble AC: Perceptual properties of benzoic acid derivatives. Chem Senses. 1995 Aug;20(4):393-400. [PubMed:8590024 ]
  7. Buskin JN, Upton RA, Williams RL: Improved liquid-chromatography of aspirin, salicylate, and salicyluric acid in plasma, with a modification for determining aspirin metabolites in urine. Clin Chem. 1982 May;28(5):1200-3. [PubMed:7074905 ]
  8. Liu JH, Smith PC: Direct analysis of salicylic acid, salicyl acyl glucuronide, salicyluric acid and gentisic acid in human plasma and urine by high-performance liquid chromatography. J Chromatogr B Biomed Appl. 1996 Jan 12;675(1):61-70. [PubMed:8634769 ]
  9. Coudray C, Talla M, Martin S, Fatome M, Favier A: High-performance liquid chromatography-electrochemical determination of salicylate hydroxylation products as an in vivo marker of oxidative stress. Anal Biochem. 1995 May 1;227(1):101-11. [PubMed:7668368 ]
  10. Bochner F, Graham GG, Cham BE, Imhoff DM, Haavisto TM: Salicylate metabolite kinetics after several salicylates. Clin Pharmacol Ther. 1981 Aug;30(2):266-75. [PubMed:7249509 ]
  11. Cham BE, Bochner F, Imhoff DM, Johns D, Rowland M: Simultaneous liquid-chromatographic quantitation of salicylic acid, salicyluric acid, and gentisic acid in urine. Clin Chem. 1980 Jan;26(1):111-4. [PubMed:7356541 ]