Picolinic acid is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula C₅H₄N(CO₂H). It is a derivative of

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a ...

with a carboxylic acid (COOH) substituent at the 2-position. It is an isomer of nicotinic acid and isonicotinic acid, which have the carboxyl side chain at the 3- and 4-position, respectively. It is a white solid that is soluble in water. In

synthetic organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J ...

, has been used as a substrate in the

Mitsunobu reaction The Mitsunobu reaction is an organic reaction that converts an alcohol into a variety of functional groups, such as an ester, using triphenylphosphine and an azodicarboxylate such as diethyl azodicarboxylate (DEAD) or diisopropyl azodicarboxylat ...

and in the Hammick reaction.

Coordination chemistry

Picolinic acid is a bidentate chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body. Many of its complexes are charge-neutral and thus

lipophilic Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipo ...

. After its role in absorption was discovered, zinc picolinate dietary supplements became popular as they were shown to be an effective means of introducing

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

into the body.

Production

Picolinic acid is formed from 2-methylpyridine by

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

, e.g. by means of

potassium permanganate Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution. Potassium permanganate is widely used in the c ...

(KMnO₄). : Oxidation of 2-picoline

Biosynthesis

Picolinic acid is a catabolite of the amino acid

tryptophan Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic ...

through the

kynurenine pathway 400px, The kynurenine pathway The kynurenine pathway is a metabolic pathway leading to the production of nicotinamide adenine dinucleotide (NAD+). Metabolites involved in the kynurenine pathway include tryptophan, kynurenine, kynurenic acid, xant ...

. Its function is unclear, but it has been implicated in a variety neuroprotective, immunological, and anti-proliferative effects. In addition, it is suggested to assist in the absorption of zinc(II) ions and other divalent or trivalent ions through the small intestine.

Picolinates

Salts of picolinic acid (picolinates) include: * Chromium(III) picolinate * Zinc picolinate

References

{{Use dmy dates, date=March 2018 2-Pyridyl compounds Glycine receptor agonists Chelating agents Aromatic acids

Coordination chemistry

Production

Biosynthesis

Picolinates

See also

References