Description
Gentisic acid is a dihydroxy benzoic 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.
Description
Gentisic acid is a benzoic acid that has been found in
Gentiana and an active metabolite of aspirin with diverse biological activities. It decreases radiation-induced production of thiobarbituric acid reactive substances (TBARS), hydrogen peroxide, and protein carbonyls, increases superoxide dismutase activity, and prevents hemolysis in isolated human erythrocytes when used at concentrations ranging from 5 to 100 μM. Gentisic acid (1-10 μM) inhibits LDL oxidation and formation of cholesterol ester hydroperoxides in isolated human plasma. It induces relaxation of isolated guinea pig trachea (EC
50 = 20 μM), an effect that is reduced by the large-conductance calcium-activated potassium channel blocker charybdotoxin . Gentisic acid (10 and 100 mg/kg) reduces cardiac hypertrophy and fibrosis and pulmonary remodeling, suppresses the renin-angiotensin-aldosterone system, and inhibits cardiac dysfunction in a mouse model of transverse aortic constriction-induced cardiac hypertrophy. It also prevents cardiovascular collapse and lactic acidemia in a canine model of
P. aeruginosa-induced septic shock.
Chemical Properties
White to light beige crystalline powder. 2,5-Dihydroxybenzoic Acid [490-79-9]
(gentisic acid, 2,5-DHBA), C7H6O4, Mr 154.1,
mp 205 C, is soluble in water and alcohols but
insoluble in benzene and chloroform. The acid is
stable in boiling water and gives a deep blue color
with iron(III) chloride. Here, the acid decomposes to form p-benzoquinone [106-51-4] and
carbon dioxide. 2–5-Dihydroxybenzoic acid is used as an
antirheumatic drug and, more recently, as a color
developer for thermal paper.
Uses
Medicine, as sodium gentisate (analgesic).
Uses
2,5-dihydroxybenzoic acid are?used as intermediates for pharmaceuticals (especially for antipyetic anlgesic, antirheumatism) and other organic synthesis. They are used as matrix for ionization of peptides, proteins and carbohydrates. In industrial field, they are?used as intermediates for the production of other organic chemicals, resins, polyesters, plasticizers, dyestuffs, preservatives, and rubber chemicals.
Application
As a hydroquinone , gentisic acid is readily oxidized 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 , and has been shown to conveniently detect peptides incorporating the boronic acid moiety by MALDI .
Production Methods
Gentisic acid is produced by carboxylation of hydroquinone.
C
6H
4(OH)
2 + CO2 → C
6H
3(CO
2H)(OH)
2 This conversion is an example of a Kolbe–Schmitt reaction.
Definition
ChEBI: A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions.
Synthesis Reference(s)
Journal of the American Chemical Society, 72, p. 3292, 1950
DOI: 10.1021/ja01163a521
General Description
Aspirin metabolite.
Safety Profile
Poison bp intravenous
route. Moderately toxic by ingestion and
intraperitoneal routes. Experimental
teratogenic and reproductive effects.
Mutation data reported. When heated to
decomposition it emits acrid smoke and
irritating fumes.
Purification Methods
Crystallise gentisic acid from hot water or *benzene/acetone. Dry it in a vacuum desiccator over silica gel. [Beilstein 10 H 384, 10 IV 1441.]
