Picolinic acid


Picolinic acid is an organic compound with the formula C5H4N. It is a derivative of pyridine with a carboxylic acid 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, has been used as a substrate in the Mitsunobu reaction 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. After its role in absorption was discovered, zinc dipicolinate dietary supplements 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 by oxidation, e.g. by means of potassium permanganate.

Biosynthesis

Picolinic acid is a catabolite 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 ions and other divalent or trivalent ions through the small intestine.

Picolinates

Salts of picolinic acid include,