Aconitic acid

cis-Aconitic acid (top) and trans-Aconitic acid (bottom)^[1]


IUPAC name Prop-1-ene-1,2,3-tricarboxylic acid
Other names Achilleic acid; Equisetic acid; Citridinic acid; Pyrocitric acid
Identifiers
CAS number	499-12-7 ^Y
PubChem	309
ChemSpider	303^Y
UNII	93371T1BXP^Y
MeSH	Aconitate
ChEBI	CHEBI:22211^Y
Jmol-3D images	Image 1
SMILES O=C(O)CC(=CC(=O)O)C(=O)O
InChI InChI=1S/C6H6O6/c7-4(8)1-3(6(11)12)2-5(9)10/h1H,2H2,(H,7,8)(H,9,10)(H,11,12)^Y Key: GTZCVFVGUGFEME-UHFFFAOYSA-N^Y InChI=1/C6H6O6/c7-4(8)1-3(6(11)12)2-5(9)10/h1H,2H2,(H,7,8)(H,9,10)(H,11,12) Key: GTZCVFVGUGFEME-UHFFFAOYAL
Properties
Molecular formula	C₆H₆O₆
Molar mass	174.11 g mol⁻¹
Appearance	Colorless crystals
Melting point	190 °C (decomp) (trans isomer), 122 °C (cis isomer)
Acidity (pK_a)	2.80, 4.46 (trans isomer) ^[2]
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Aconitic acid is an organic acid. The two isomers are cis-aconitic acid and trans-aconitic acid. The conjugate base of cis-aconitic acid, cis-aconitate is an intermediate in the isomerization of citrate to isocitrate in the citric acid cycle. It is acted upon by the enzyme aconitase.

Aconitic acid can be synthesized by dehydration of citric acid using sulfuric acid:^[3]

(HO₂CCH₂)₂COH(CO₂H) → HO₂CCH=C(CO₂H)CH₂CO₂H + H₂O

It was first prepared by thermal dehydration.^[4]

References

^ cis-aconitate - Compound Summary, PubChem
'^ Dawson, R. M. C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.
^ William F. Bruce (1943), "Aconitic Acid", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV2P0012 ; Coll. Vol. 2: 12
^ B. Pawolleck,"Substitutionsproducte der Citronensäure und ein Versuch zur Synthese der letzteren" Justus Liebig's Annalen der Chemie 1875, volume 178, 150-170. doi:10.1002/jlac.18751780203