Quinic acid is a
cyclitol, a cyclic polyol, and a
cyclohexanecarboxylic acid. 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
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
A coffee bean is a seed of the ''Coffea'' plant and the source for coffee. It is the pip inside the red or purple fruit often referred to as a coffee cherry. Just like ordinary cherries, the coffee fruit is also a so-called stone fruit. Even tho ...
, and the bark of ''
Eucalyptus globulus
''Eucalyptus globulus'', commonly known as southern blue gum or blue gum, is a species of tall, evergreen tree endemic to southeastern Australia. This ''Eucalyptus'' species has mostly smooth bark, juvenile leaves that are whitish and waxy on ...
''. 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. Ori ...
'' 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, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolys ...
of
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 ( caf ...
. 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 (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
pharmacist Friedrich Christian Hofmann in
Leer from
Cinchona. Its transformation into
hippuric acid
Hippuric acid ( 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 consumption of phenol ...
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 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.
In addition, it serves as a precursor in the biosynthesis of the aromatic amino acids tyrosine, pheny ...
. This four-carbon substrate is condensed with
phosphoenol pyruvate
Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the ester derived from the enol of pyruvate and phosphate. It exists as an anion. PEP is an important intermediate in biochemistry. It has the highest-energy phosphate bond found (−61.9 kJ/m ...
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, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring.
Lactones are formed by intramolecular esterification of the co ...
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 plants. I ...
.
[
]
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". Calamine lotion, witch hazel, and yerba mansa, a Californian pla ...
.
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, 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 complications or are at high ...
, which is used to treat influenza A
'' A virus'' (''IAV'') causes influenza in birds and some mammals, and is the only species of the genus ''Alphainfluenzavirus'' of the virus family ''Orthomyxoviridae''. Strains of all subtypes of influenza A virus have been isolated from wild ...
and B.
References
Further reading
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{{DEFAULTSORT:Quinic Acid
Cyclohexanecarboxylic acids
Tetrols