Citramalic acid

Citramalic acid
Names
	Other names (R)-2-hydroxy-2-methylbutanedioic acid, 2-methylmalic acid, D-(−)-2-methylmalic acid, (R)-2-hydroxy-2-methylsuccinic acid
Identifiers
CAS Number	6236-10-8 R-enantiomer;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:15586;
ChemSpider	388822;
ECHA InfoCard	100.154.104
EC Number	±: 209-901-5;
KEGG	C02612;
PubChem CID	439766;
UNII	788CNO6T4D;
CompTox Dashboard (EPA)	DTXSID80331440 ;
	InChI InChI=1S/C5H8O5/c1-5(10,4(8)9)2-3(6)7/h10H,2H2,1H3,(H,6,7)(H,8,9)/t5-/m1/s1 Key: XFTRTWQBIOMVPK-RXMQYKEDSA-N;
	SMILES C[C@@](CC(=O)O)(C(=O)O)O;
Properties
Chemical formula	C5H8O5
Molar mass	148.114 g·mol−1
Appearance	white solid
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Citramalic acid is the organic compound with the formula HO₂CCH₂C(CH₃)(OH)CO₂H. A chiral compound, it is related structurally to malic acid.

Synthesis and reactions

Citramalic acid is the hydrated derivative of mesaconic acid, The hydration is catalyzed by mesaconyl-C4-CoA hydratase:

HO₂CCH=C(CH₃)CO₂H + H₂O → HO₂CCH₂C(CH₃)(OH)CO₂H

The same conversion can be achieved in vitro.^[1]

The enzyme (S)-citramalyl-CoA lyase converts citramalyl-CoA to acetyl-CoA and pyruvate.^[2]

^ Eck, Richard; Simon, Helmut (1994). "Preparation of Both Enantiomers of Malic and Ctramalic Acid and Other Hydroxysuccinic Acid Derivatives by Stereospecific Hydrations of cis or trans 2-Butene-1,4-dioic Acids with Resting Cells of Clostridium formicoaceticum". Tetrahedron. 50 (48): 13641–13654. doi:10.1016/S0040-4020(01)85678-7.
^ Berg, Ivan A. (2011). "Ecological Aspects of the Distribution of Different Autotrophic CO₂ Fixation Pathways". Applied and Environmental Microbiology. 77 (6): 1925–1936. Bibcode:2011ApEnM..77.1925B. doi:10.1128/AEM.02473-10. PMC 3067309. PMID 21216907.