Quinic acid

Quinic acid is an organic compound with the formula (CHOH)₃(CH₂)₂C(OH)CO₂H. The compound is classified as 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, where it occurs around 13% by weight.^[3]

Quinic acid

Quinic acid Quinic acid
Names
IUPAC name 1ʟ-1(OH),3,4/5-Tetrahydroxycyclohexanecarboxylic acid [1]
Preferred IUPAC name (1S,3R,4S,5R)-1,3,4,5-Tetrahydroxycyclohexane-1-carboxylic acid
Identifiers
CAS Number	77-95-2 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17521 Y
ChEMBL	ChEMBL465398 Y
ChemSpider	10246715 Y
ECHA InfoCard	100.000.976
PubChem CID	6508
UNII	058C04BGYI Y
CompTox Dashboard (EPA)	DTXSID70998288
InChI InChI=1S/C7H12O6/c8-3-1-7(13,6(11)12)2-4(9)5(3)10/h3-5,8-10,13H,1-2H2,(H,11,12)/t3-,4-,5-,7+/m1/s1 Y Key: AAWZDTNXLSGCEK-WYWMIBKRSA-N Y InChI=1/C7H12O6/c8-3-1-7(13,6(11)12)2-4(9)5(3)10/h3-5,8-10,13H,1-2H2,(H,11,12)/t3-,4-,5-,7+/m1/s1 Key: AAWZDTNXLSGCEK-WYWMIBKRBU
SMILES O[C@]1(C[C@@H](O)[C@@H](O)[C@H](O)C1)C(O)=O
Properties
Chemical formula	C7H12O6
Molar mass	192.17 g/mol
Density	1.35 g/cm3
Melting point	168 °C (334 °F; 441 K)
Hazards
GHS labelling:
Pictograms	[2]
Signal word	Warning[2]
Hazard statements	H319[2]
Precautionary statements	P264, P280, P305+P351+P338, P337+P313[2]
NFPA 704 (fire diamond)	0 0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Occurrence and preparation

The compound is obtained from cinchona bark, coffee beans, and the bark of Eucalyptus globulus.^[4] It is a constituent of the tara tannins.

Urtica dioica, the European stinging nettle, is another common source.^[5]

It is made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee.

History and biosynthesis

Shikimic acid, biosynthetic precursor to aromatic amino acids, is a close relative of quinic acid.

This substance was isolated for the first time in 1790 by German pharmacist Friedrich Christian Hofmann in Leer from Cinchona.^[6] Its transformation into hippuric acid by animal metabolism was studied by German chemist Eduard Lautemann in 1863.^[7]

Its biosynthesis 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.^[8]

Derived bicyclic lactones are called quinides. One example is 4-caffeoyl-1,5-quinide.

Dehydrogenation and oxidation of quinic acid affords gallic acid.^[8]

Applications and medicinal activity

Quinic acid is used as an astringent.

This acid is a versatile chiral starting material for the synthesis of pharmaceuticals.^[8] It is a building block in the synthesis of oseltamivir, which is used to treat influenza A and B.