Picolinic acid is an organic compound with the formula C₅H₄N(CO₂H). It is a derivative of pyridine with a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

(COOH) substituent at the 2-position. It is an

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...

nicotinic acid Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...

and

isonicotinic acid Isonicotinic acid or pyridine-4-carboxylic acid is an organic compound with the formula C5H4N(CO2H). It is a derivative of pyridine with a carboxylic acid substituent at the 4-position. It is an isomer of picolinic acid and Niacin (substance), nic ...

, 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, has been used as a substrate in the Mitsunobu reaction and in the

Hammick reaction The Hammick reaction, named after Dalziel Hammick, is a chemical reaction in which the thermal decarboxylation of α-picolinic acid, picolinic (or related) carboxylic acid, acids in the presence of carbonyl compounds forms 2-pyridine, pyridyl-carbi ...

Coordination chemistry

Picolinic acid is a bidentate

chelating agent Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...

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. After its role in absorption was discovered, zinc picolinate

dietary supplements A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients either extr ...

became popular as they were shown to be an effective means of introducing zinc into the body.

Production

Picolinic acid is formed from

2-methylpyridine 2-Methylpyridine, or 2-picoline, is the compound described with formula C6H7N. 2-Picoline is a colorless liquid that has an unpleasant odor similar to pyridine. It is mainly used to make vinylpyridine and the agrichemical nitrapyrin. Synthesis 2 ...

by oxidation, e.g. by means of potassium permanganate (KMnO₄). : Oxidation of 2-picoline

Biosynthesis

Picolinic acid is a

catabolite Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipid ...

of the amino acid tryptophan through the kynurenine pathway. 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 The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the p ...

Picolinates

Salts of picolinic acid (picolinates) include: *

Chromium(III) picolinate Chromium(III) picolinate is a chemical compound with the formula Cr(C5H4N(CO2H))3, commonly abbreviated as CrPic3. It is sold as a nutritional supplement to treat type 2 diabetes and promote weight loss. This bright-red coordination compound is de ...

Zinc picolinate Zinc picolinate (or ZnPic) is the zinc salt of picolinic acid Picolinic acid is an organic compound with the formula C5H4N(CO2H). It is a derivative of pyridine with a carboxylic acid (COOH) substituent at the 2-position. It is an isomer of ...

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