2,5-Dihydroxybenzoic acid

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 (EC₅₀ = 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.

The Uses of 2,5-Dihydroxybenzoic acid

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.

The Uses of 2,5-Dihydroxybenzoic acid

Medicine, as sodium gentisate (analgesic).

Definition

ChEBI: A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions.

Production Methods

Gentisic acid is produced by carboxylation of hydroquinone.
C₆H₄(OH)₂ + CO2 → C₆H₃(CO₂H)(OH)₂
This conversion is an example of a Kolbe–Schmitt reaction.

What are the applications of 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 .

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.]