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Record Information
Version4.0
StatusExpected but not Quantified
Creation Date2013-07-09 16:08:52 UTC
Update Date2019-07-23 07:15:26 UTC
HMDB IDHMDB0060946
Secondary Accession Numbers
  • HMDB60946
Metabolite Identification
Common NameNAPQI
DescriptionNAPQI, also known as acetimidoquinone or NABQ, belongs to the class of organic compounds known as secondary ketimines. These are ketimines where the nitrogen of the ketimine group is linked to an alkyl or aryl group. A small amount of the drug is metabolized via the cytochrome P-450 pathway (to be specific, CYP3A4 and CYP2E1) into NAPBQI, which is extremely toxic to liver tissue, as well as being a strong biochemical oxidizer. NAPQI is an extremely weak basic (essentially neutral) compound (based on its pKa). Within humans, NAPQI participates in a number of enzymatic reactions. In particular, NAPQI can be biosynthesized from acetaminophen through its interaction with the enzymes cytochrome P450 2E1, cytochrome P450 1A2, cytochrome P450 2D6, cytochrome P450 3A4, and cytochrome P450 2A6. In addition, NAPQI and glutathione can be converted into acetaminophen cystein; which is catalyzed by the enzymes glutathione S-transferase p and glutathione S-transferase theta-1. Most hospitals stock the antidote (acetylcysteine), which replenishes the liver's supply of glutathione, allowing the NAPQI to be metabolized safely. The minimum dosage at which paracetamol causes toxicity usually is 7.5 to 10g in the average person. In humans, NAPQI is involved in acetaminophen metabolism pathway. Chronic alcoholics may be more susceptible to adverse effects due to reduced glutathione levels. It can be given in large amounts without side-effects.
Structure
Data?1563866126
Synonyms
ValueSource
4-Acetylimino-2,5-cyclohexadien-1-oneChEBI
AcetimidoquinoneChEBI
N-Acetyl-4-benzoquinoneimineChEBI
N-Acetyl-p-benzoquinone imineChEBI
N-AcetylbenzoquinoneimineChEBI
N-Acetyl-4-benzoquinone imineHMDB
N-Acetyl-4-benzoquinoneimine, 3,5-(14)C-labeled CPDHMDB
N-Acetyl-p-benzoquinoneimineHMDB
NABQHMDB
Chemical FormulaC8H7NO2
Average Molecular Weight149.1467
Monoisotopic Molecular Weight149.047678473
IUPAC NameN-(4-oxocyclohexa-2,5-dien-1-ylidene)acetamide
Traditional NameN-acetyl-p-benzoquinone
CAS Registry NumberNot Available
SMILES
CC(=O)N=C1C=CC(=O)C=C1
InChI Identifier
InChI=1S/C8H7NO2/c1-6(10)9-7-2-4-8(11)5-3-7/h2-5H,1H3
InChI KeyURNSECGXFRDEDC-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of organic compounds known as secondary ketimines. These are ketimines where the nitrogen of the ketimine group is linked to an alkyl or aryl group.
KingdomOrganic compounds
Super ClassOrganic nitrogen compounds
ClassOrganonitrogen compounds
Sub ClassImines
Direct ParentSecondary ketimines
Alternative Parents
Substituents
  • Secondary ketimine
  • Azomethine
  • Cyclic ketone
  • N-acylimine
  • Ketone
  • Organic 1,3-dipolar compound
  • Propargyl-type 1,3-dipolar organic compound
  • Carboxylic acid derivative
  • Organic oxygen compound
  • Organopnictogen compound
  • Organic oxide
  • Hydrocarbon derivative
  • Organooxygen compound
  • Carbonyl group
  • Aliphatic homomonocyclic compound
Molecular FrameworkAliphatic homomonocyclic compounds
External Descriptors
Ontology
Disposition

Source:

Biological location:

Process

Naturally occurring process:

Role

Biological role:

Physical Properties
StateNot Available
Experimental Properties
PropertyValueReference
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
Water Solubility0.99 g/LALOGPS
logP0.53ALOGPS
logP0.57ChemAxon
logS-2.2ALOGPS
pKa (Strongest Acidic)19.14ChemAxon
pKa (Strongest Basic)-0.31ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area46.5 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity42.45 m³·mol⁻¹ChemAxon
Polarizability14.65 ųChemAxon
Number of Rings1ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-0006-9500000000-26d4378e16051e29f3a0Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0udi-0900000000-ac4176497e66953d40c0Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0pb9-0900000000-742d4824d6c715e26f22Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-002f-9000000000-6e485c18c7bf55922b57Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0002-0900000000-2a0e88975df639fa0154Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0a4j-0900000000-d205478121975decd1e6Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4i-5900000000-069af19709609ef10b8dSpectrum
Biological Properties
Cellular Locations
  • Cytoplasm
Biospecimen Locations
  • Blood
  • Urine
Tissue Locations
  • Kidney
  • Liver
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableNormal
      Not Available
details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableNormal
      Not Available
details
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDNot Available
KNApSAcK IDNot Available
Chemspider IDNot Available
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNAPQI
METLIN IDNot Available
PubChem Compound39763
PDB IDNot Available
ChEBI ID29132
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB ID
References
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General ReferencesNot Available