Gentisic acid

Gentisic acid[1]
IUPAC name

2,5-dihydroxybenzoic acid
Other names

DHB
2,5-dihydroxybenzoic acid
5-Hydroxysalicylic acid
Gentianic acid
Carboxyhydroquinone
2,5-Dioxybenzoic Acid
Hydroquinonecarboxylic acid
Identifiers
CAS number 490-79-9 Y
PubChem 3469
ChemSpider 3350 Y
UNII VP36V95O3T Y
KEGG C00628 Y
ChEBI CHEBI:17189 Y
ChEMBL CHEMBL1461 Y
Jmol-3D images Image 1
Properties
Molecular formula C7H6O4
Molar mass 154.12 g/mol
Appearance white to yellow powder
Melting point

200 - 205 C (Sublimes)
 Y (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 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.[2]

Production

Gentisic acid is produced by carboxylation of hydroquinone.[3]

C6H4(OH)2 + CO2 → C6H3(CO2H)(OH)2

This conversion is an example of a Kolbe–Schmitt reaction.

Applications

As a hydroquinone, gentisic acid is readily oxidised and is used as an antioxidant excipient in some pharmaceutical preparations.

In the laboratory, it is used as a sample matrix in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, [4] and has been shown to conveniently detect peptides incorporating the boronic acid moiety by MALDI. [5]

References

  1. ^ Gentisic acid - Compound Summary, PubChem.
  2. ^ Levy, G; Tsuchiya, T (1972-09-31). "Salicylate accumulation kinetics in man". New England Journal of Medicine 287 (9): 430–2. doi:10.1056/NEJM197208312870903. PMID 5044917. 
  3. ^ Phillip M. Hudnall "Hydroquinone" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. 2005 Wiley-VCH, Weinheim. doi:10.1002/14356007.a13_499.
  4. ^ Strupat K, Karas M, Hillenkamp F (1991). "2,5-Dihidroxybenzoic acid: a new matrix for laser desorption-ionization mass spectrometry". Int. J. Mass Spectrom. Ion Processes 72 (111): 89–102. Bibcode 1991IJMSI.111...89S. doi:10.1016/0168-1176(91)85050-V. 
  5. ^ Crumpton, J.; Zhang, W.; Santos, W. L. (2011). "Facile Analysis and Sequencing of Linear and Branched Peptide Boronic Acids by MALDI Mass Spectrometry". Analytical Chemistry 83 (9): 3548–3554. doi:10.1021/ac2002565. PMC 3090651. PMID 21449540. http://pubs.acs.org/doi/abs/10.1021/ac2002565. 
Monohydroxybenzoic acids
Dihydroxybenzoic acids
Trihydroxybenzoic acids