Quinic acid is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula . The compound is classified as a

cyclitol In organic chemistry, a cyclitol is a cycloalkane containing at least three hydroxyl, each attached to a different ring carbon atom. The general formula for an unsubstituted cyclitol is or where 3 ≤ ''x'' ≤ ''n''. The name is also used for ...

, a cyclic polyol, and a

cyclohexanecarboxylic acid Cyclohexanecarboxylic acid is the organic compound with the formula C6H11CO2H. It is the carboxylic acid of cyclohexane. It is a colorless oil that crystallizes near room temperature.. Preparation and reactions It is prepared by hydrogenation of ...

. It is a colorless solid that can be extracted from plant sources. Quinic acid is implicated in the perceived acidity of coffee, where it occurs around 13% by weight.

Occurrence and preparation

The compound is obtained from

cinchona bark Jesuit's bark, also known as cinchona bark, Peruvian bark or China bark, is a former remedy for malaria, as the bark contains quinine, used to treat the disease. The bark of several species of the genus ''Cinchona'', family Rubiaceae indigenous ...

, coffee beans, and the bark of ''

Eucalyptus globulus ''Eucalyptus globulus'', commonly known as southern blue gum or blue gum, is a species of flowering plant in the family Myrtaceae. It is a tall, evergreen tree Endemism, endemic to southeastern Australia. This ''Eucalyptus'' species has most ...

''. It is a constituent of the tara tannins. ''

Urtica dioica ''Urtica dioica'', often known as common nettle, burn nettle, stinging nettle (although not all plants of this species sting) or nettle leaf, or just a nettle or stinger, is a herbaceous perennial flowering plant in the family Urticaceae. Or ...

'', the European stinging nettle, is another common source. It is made synthetically by

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

chlorogenic acid Chlorogenic acid (CGA) is the ester of caffeic acid and quinic acid, functioning as an intermediate in lignin biosynthesis. The term chlorogenic acids refers to a related polyphenol family of esters, including hydroxycinnamic acids ( caffeic a ...

. Quinic acid is also implicated in the perceived acidity of coffee.

History and biosynthesis

This substance was isolated for the first time in 1790 by

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

pharmacist A pharmacist, also known as a chemist in English in the Commonwealth of Nations, Commonwealth English, is a healthcare professional who is knowledgeable about preparation, mechanism of action, clinical usage and legislation of medications in ...

Friedrich Christian Hofmann in

Leer Leer may refer to: * Leer, Lower Saxony, town in Germany ** Leer (district), containing the town in Lower Saxony, Germany ** Leer (Ostfriesland) railway station * Leer, South Sudan, town in South Sudan ** Leer County, an administrative division ...

from

Cinchona ''Cinchona'' (pronounced or ) is a genus of flowering plants in the family Rubiaceae containing at least 23 species of trees and shrubs. All are native to the Tropical Andes, tropical Andean forests of western South America. A few species are ...

. Its transformation into

hippuric acid Hippuric acid (Greek language, Gr. ''hippos'', horse, ''ouron'', urine) is a carboxylic acid and organic compound. It is found in urine and is formed from the combination of benzoic acid and glycine. Levels of hippuric acid rise with the consumpt ...

by animal metabolism was studied by German chemist Eduard Lautemann in 1863.Lautemann, E. (1863
"Ueber die Reduction der Chinasäure zu Benzoësäure und die Verwandlung derselben in Hippursäure im thierischen Organismus"
(On the reduction of quinic acid to benzoic acid and its transformation into hippuric acid in the animal organism), ''Annalen der Chemie'', 125 : 9–13. Its

biosynthesis Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...

begins with the transformation of glucose into

erythrose 4-phosphate Erythrose 4-phosphate is a phosphate of the simple sugar erythrose. It is an intermediate in the pentose phosphate pathway and the Calvin cycle. The enzyme transaldolase catalyzes the formation of erythrose 4-phosphate and fructose 6-phosphate ...

. This four-carbon substrate is condensed with

phosphoenol pyruvate Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the carboxylic acid derived from the enol of pyruvate and a phosphate anion. It exists as an anion. PEP is an important intermediate in biochemistry. It has the highest-energy phosphate bond f ...

to give the seven-carbon 3-deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) by the action of a synthase. Two subsequent steps involving dehydroquinic acid synthase and a dehydrogenase afford the compound. Derived bicyclic

lactone Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresp ...

s are called quinides. One example is

4-caffeoyl-1,5-quinide 4-Caffeoyl-1,5-quinide (4-caffeoylquinic-1,5-lactone or 4-CQL) is found in roasted coffee beans. It is formed by lactonization of 4-''O''-caffeoylquinic acid during the roasting process. : It is reported to possess opioid antagonist properties i ...

Dehydrogenation In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At ...

and oxidation of quinic acid affords

gallic acid Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6 H2( OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plant ...

Applications and medicinal activity

Quinic acid is used as an

astringent An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin '' adstringere'', which means "to bind fast". Astringency, the dry, puckering or numbing mouthfeel caused by t ...

. This acid is a versatile chiral starting material for the synthesis of pharmaceuticals. It is a building block in the synthesis of

oseltamivir Oseltamivir, sold under the brand name Tamiflu among others, is an antiviral medication used to treat and prevent influenza A and influenza B, viruses that cause the flu. Many medical organizations recommend it in people who have complicati ...

, which is used to treat

influenza A ''Influenza A virus'' (''Alphainfluenzavirus influenzae'') or IAV is the only species of the genus ''Alphainfluenzavirus'' of the virus family '' Orthomyxoviridae''. It is a pathogen with strains that infect birds and some mammals, as well as c ...

and B.

Occurrence and preparation

History and biosynthesis

Applications and medicinal activity

References

Further reading