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Record Information
StatusExpected but not Quantified
Creation Date2012-09-12 01:45:13 UTC
Update Date2019-07-23 06:31:47 UTC
Secondary Accession Numbers
  • HMDB40216
Metabolite Identification
Common Name2,6,6-Trimethyl-2-cyclohexene-1,4-dione
Description2,6,6-Trimethyl-2-cyclohexene-1,4-dione, also known as ketoisophorone or 2-cyclohexen-1,4-dione, 2,6,6-trimethyl, belongs to the class of organic compounds known as cyclohexenones. Cyclohexenones are compounds containing a cylohexenone moiety, which is a six-membered aliphatic ring that carries a ketone and has one endocyclic double bond. 2,6,6-Trimethyl-2-cyclohexene-1,4-dione is an extremely weak basic (essentially neutral) compound (based on its pKa). Outside of the human body, 2,6,6-Trimethyl-2-cyclohexene-1,4-dione has been detected, but not quantified in, tea. This could make 2,6,6-trimethyl-2-cyclohexene-1,4-dione a potential biomarker for the consumption of these foods.
2,2,6-Trimethyl-2-cyclohexene-1,4-dione (cetoisophorone)HMDB
2,2,6-Trimethylcyclohex-2-en-1,4-dione (4-oxo-isophorone)HMDB
2,6,6-Trimethy-2-cyclohexene-1,4-dione (4-oxoisophorone)HMDB
2-Cyclohexen-1,4-dione, 2,6,6-trimethylHMDB
Chemical FormulaC9H12O2
Average Molecular Weight152.1904
Monoisotopic Molecular Weight152.083729628
IUPAC Name2,6,6-trimethylcyclohex-2-ene-1,4-dione
Traditional Name2,6,6-trimethylcyclohex-2-ene-1,4-dione
CAS Registry Number1125-21-9
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as cyclohexenones. Cyclohexenones are compounds containing a cylohexenone moiety, which is a six-membered aliphatic ring that carries a ketone and has one endocyclic double bond.
KingdomOrganic compounds
Super ClassOrganic oxygen compounds
ClassOrganooxygen compounds
Sub ClassCarbonyl compounds
Direct ParentCyclohexenones
Alternative Parents
  • Cyclohexenone
  • Organic oxide
  • Hydrocarbon derivative
  • Aliphatic homomonocyclic compound
Molecular FrameworkAliphatic homomonocyclic compounds
External DescriptorsNot Available

Route of exposure:


Biological location:


Naturally occurring process:


Industrial application:

Biological role:

Physical Properties
Experimental Properties
Melting Point21 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility8.73 g/LALOGPS
pKa (Strongest Acidic)18.85ChemAxon
pKa (Strongest Basic)-6.4ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area34.14 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity43.39 m³·mol⁻¹ChemAxon
Polarizability16.33 ųChemAxon
Number of Rings1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-0pbc-9400000000-ac4a8e5a500a122e8961Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0udi-1900000000-a2ede87c0b92081444bfSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0udi-5900000000-43128d887aa49e04c996Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-052f-9000000000-8359b62696f36de8253dSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0udi-0900000000-4d79e09516d33207e352Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0udi-1900000000-ebd44ede68a343ed2c8cSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-052r-9300000000-edfbab726fbefc90241cSpectrum
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Membrane
Biospecimen LocationsNot Available
Tissue LocationsNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDFDB004389
KNApSAcK IDC00035002
Chemspider ID56162
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
METLIN IDNot Available
PubChem Compound62374
PDB IDNot Available
ChEBI IDNot Available
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB ID
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Jerkovic I, Mastelic J, Marijanovic Z: A variety of volatile compounds as markers in unifloral honey from dalmatian sage (Salvia officinalis L.). Chem Biodivers. 2006 Dec;3(12):1307-16. [PubMed:17193245 ]
  2. Lechtenberg M, Schepmann D, Niehues M, Hellenbrand N, Wunsch B, Hensel A: Quality and functionality of saffron: quality control, species assortment and affinity of extract and isolated saffron compounds to NMDA and sigma1 (sigma-1) receptors. Planta Med. 2008 Jun;74(7):764-72. doi: 10.1055/s-2008-1074535. Epub 2008 May 21. [PubMed:18496783 ]
  3. Raimondi S, Roncaglia L, Amaretti A, Leonardi A, Buzzini P, Forti L, Rossi M: Rapid method for screening enoate reductase activity in yeasts. J Microbiol Methods. 2010 Nov;83(2):106-10. doi: 10.1016/j.mimet.2010.09.007. Epub 2010 Sep 16. [PubMed:20849886 ]
  4. Goretti M, Ponzoni C, Caselli E, Marchegiani E, Cramarossa MR, Turchetti B, Forti L, Buzzini P: Bioreduction of alpha,beta-unsaturated ketones and aldehydes by non-conventional yeast (NCY) whole-cells. Bioresour Technol. 2011 Mar;102(5):3993-8. doi: 10.1016/j.biortech.2010.12.062. Epub 2010 Dec 22. [PubMed:21232941 ]
  5. Zhuang X, Klingeman WE, Hu J, Chen F: Emission of volatile chemicals from flowering dogwood (cornus Florida L.) flowers. J Agric Food Chem. 2008 Oct 22;56(20):9570-4. doi: 10.1021/jf801651v. Epub 2008 Sep 24. [PubMed:18811168 ]
  6. Jerkovic I, Tuberoso CI, Gugic M, Bubalo D: Composition of sulla (Hedysarum coronarium L.) honey solvent extractives determined by GC/MS: norisoprenoids and other volatile organic compounds. Molecules. 2010 Sep 9;15(9):6375-85. doi: 10.3390/molecules15096375. [PubMed:20877229 ]
  7. Kataoka M, Kotaka A, Hasegawa A, Wada M, Yoshizumi A, Nakamori S, Shimizu S: Old Yellow Enzyme from Candida macedoniensis catalyzes the stereospecific reduction of the C=C bond of ketoisophorone. Biosci Biotechnol Biochem. 2002 Dec;66(12):2651-7. [PubMed:12596862 ]
  8. Chen K, Sun Y, Wang C, Yao J, Chen Z, Li H: Aerobic oxidation of beta-isophorone catalyzed by N-hydroxyphthalimide: the key features and mechanism elucidated. Phys Chem Chem Phys. 2012 Sep 21;14(35):12141-6. doi: 10.1039/c2cp41617d. Epub 2012 Jul 31. [PubMed:22850899 ]
  9. Kataoka M, Kotaka A, Thiwthong R, Wada M, Nakamori S, Shimizu S: Cloning and overexpression of the old yellow enzyme gene of Candida macedoniensis, and its application to the production of a chiral compound. J Biotechnol. 2004 Oct 19;114(1-2):1-9. [PubMed:15464593 ]
  10. Raimondi S, Romano D, Amaretti A, Molinari F, Rossi M: Enoate reductases from non conventional yeasts: bioconversion, cloning, and functional expression in Saccharomyces cerevisiae. J Biotechnol. 2011 Dec 20;156(4):279-85. doi: 10.1016/j.jbiotec.2011.08.033. Epub 2011 Sep 16. [PubMed:21933690 ]
  11. Hegazy ME, Hirata T, Abdel-Lateff A, el-Razek MH, Mohamed Ael-H, Hassan NM, Pare PW, Mahmoud AA: Ketoisophorone transformation by Marchantia polymorpha and Nicotiana tabacum cultured cells. Z Naturforsch C. 2008 May-Jun;63(5-6):403-8. [PubMed:18669027 ]
  12. Mohr S, Fisher K, Scrutton NS, Goddard NJ, Fielden PR: Continuous two-phase flow miniaturised bioreactor for monitoring anaerobic biocatalysis by pentaerythritol tetranitrate reductase. Lab Chip. 2010 Aug 7;10(15):1929-36. doi: 10.1039/c003561k. Epub 2010 Jun 7. [PubMed:20526519 ]
  13. (). Yannai, Shmuel. (2004) Dictionary of food compounds with CD-ROM: Additives, flavors, and ingredients. Boca Raton: Chapman & Hall/CRC.. .