Quinic acid is 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 c ...
, 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.
Occurrence and preparation
The compound is obtained from
cinchona bark,
coffee beans, and the bark of ''
Eucalyptus globulus''. It is a constituent of the
tara tannins
''Tara spinosa'', commonly known as ''tara'' ( Quechua), also known as Peruvian carob or spiny holdback, is a small leguminous tree or thorny shrub native to Peru. ''T. spinosa'' is cultivated as a source of tannins based on a galloylated quinic ...
.
''
Urtica dioica'' is another common source.
It is made synthetically by
hydrolysis of
chlorogenic acid. 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 pharmacist
A pharmacist, also known as a chemist (Commonwealth English) or a druggist (North American and, archaically, Commonwealth English), is a healthcare professional who prepares, controls and distributes medicines and provides advice and instructi ...
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 of ...
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 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 is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...
begins with the transformation of glucose into
erythrose 4-phosphate. This four-carbon substrate is condensed with
phosphoenol pyruvate 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
lactones 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 and oxidation of quinic acid affords
gallic acid.
[
]
Applications and medicinal activity
Quinic acid is used as an astringent.
This acid is a versatile chiral starting material for the synthesis of pharmaceuticals.[ It is a building block in the synthesis of Oseltamivir, which is used to treat influenza A and B.
]
References
Further reading
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{{DEFAULTSORT:Quinic Acid
Cyclohexanecarboxylic acids
Tetrols