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Record Information
Version5.0
StatusExpected but not Quantified
Creation Date2013-07-09 16:08:52 UTC
Update Date2023-02-21 17:30:16 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. 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 the action of 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 mediated by the enzymes glutathione S-transferase p and glutathione S-transferase theta-1. In humans, NAPQI is involved in acetaminophen metabolism pathway. It is normally produced only in small amounts, and then almost immediately detoxified in the liver. NAPQI is a metabolite of acetaminophen. NAPQI (N-acetyl-p-benzoquinone imine) is a toxic byproduct produced during the xenobiotic metabolism of the analgesic paracetamol (acetaminophen). However, under some conditions in which NAPQI is not effectively detoxified (usually in case of paracetamol overdose), it causes severe damage to the liver.
Structure
Data?1677000616
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
Physiological effectNot Available
Disposition
Process
RoleNot Available
Physical Properties
StateNot Available
Experimental Molecular Properties
PropertyValueReference
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Experimental Chromatographic PropertiesNot Available
Predicted Molecular 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
Predicted Chromatographic Properties

Predicted Collision Cross Sections

PredictorAdduct TypeCCS Value (Å2)Reference
DarkChem[M+H]+134.19831661259
DarkChem[M-H]-129.5431661259
DeepCCS[M+H]+131.94730932474
DeepCCS[M-H]-128.90830932474
DeepCCS[M-2H]-165.88230932474
DeepCCS[M+Na]+141.36330932474
AllCCS[M+H]+131.732859911
AllCCS[M+H-H2O]+127.232859911
AllCCS[M+NH4]+135.832859911
AllCCS[M+Na]+137.032859911
AllCCS[M-H]-130.732859911
AllCCS[M+Na-2H]-132.032859911
AllCCS[M+HCOO]-133.632859911

Predicted Retention Times

Underivatized

Chromatographic MethodRetention TimeReference
Measured using a Waters Acquity ultraperformance liquid chromatography (UPLC) ethylene-bridged hybrid (BEH) C18 column (100 mm × 2.1 mm; 1.7 μmparticle diameter). Predicted by Afia on May 17, 2022. Predicted by Afia on May 17, 2022.3.29 minutes32390414
Predicted by Siyang on May 30, 202210.5025 minutes33406817
Predicted by Siyang using ReTip algorithm on June 8, 20220.88 minutes32390414
Fem_Long = Waters ACQUITY UPLC HSS T3 C18 with Water:MeOH and 0.1% Formic Acid1501.8 seconds40023050
Fem_Lipids = Ascentis Express C18 with (60:40 water:ACN):(90:10 IPA:ACN) and 10mM NH4COOH + 0.1% Formic Acid351.9 seconds40023050
Life_Old = Waters ACQUITY UPLC BEH C18 with Water:(20:80 acetone:ACN) and 0.1% Formic Acid104.7 seconds40023050
Life_New = RP Waters ACQUITY UPLC HSS T3 C18 with Water:(30:70 MeOH:ACN) and 0.1% Formic Acid225.5 seconds40023050
RIKEN = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid82.8 seconds40023050
Eawag_XBridgeC18 = XBridge C18 3.5u 2.1x50 mm with Water:MeOH and 0.1% Formic Acid330.9 seconds40023050
BfG_NTS_RP1 =Agilent Zorbax Eclipse Plus C18 (2.1 mm x 150 mm, 3.5 um) with Water:ACN and 0.1% Formic Acid393.1 seconds40023050
HILIC_BDD_2 = Merck SeQuant ZIC-HILIC with ACN(0.1% formic acid):water(16 mM ammonium formate)130.5 seconds40023050
UniToyama_Atlantis = RP Waters Atlantis T3 (2.1 x 150 mm, 5 um) with ACN:Water and 0.1% Formic Acid912.7 seconds40023050
BDD_C18 = Hypersil Gold 1.9µm C18 with Water:ACN and 0.1% Formic Acid309.8 seconds40023050
UFZ_Phenomenex = Kinetex Core-Shell C18 2.6 um, 3.0 x 100 mm, Phenomenex with Water:MeOH and 0.1% Formic Acid1017.4 seconds40023050
SNU_RIKEN_POS = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid258.6 seconds40023050
RPMMFDA = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid255.3 seconds40023050
MTBLS87 = Merck SeQuant ZIC-pHILIC column with ACN:Water and :ammonium carbonate468.6 seconds40023050
KI_GIAR_zic_HILIC_pH2_7 = Merck SeQuant ZIC-HILIC with ACN:Water and 0.1% FA345.1 seconds40023050
Meister zic-pHILIC pH9.3 = Merck SeQuant ZIC-pHILIC column with ACN:Water 5mM NH4Ac pH9.3 and 5mM ammonium acetate in water68.3 seconds40023050

Predicted Kovats Retention Indices

Underivatized

MetaboliteSMILESKovats RI ValueColumn TypeReference
NAPQICC(=O)N=C1C=CC(=O)C=C12332.8Standard polar33892256
NAPQICC(=O)N=C1C=CC(=O)C=C11358.6Standard non polar33892256
NAPQICC(=O)N=C1C=CC(=O)C=C11645.3Semi standard non polar33892256
Spectra

GC-MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted GC-MSPredicted GC-MS Spectrum - NAPQI GC-MS (Non-derivatized) - 70eV, Positivesplash10-0006-9500000000-26d4378e16051e29f3a02017-09-20Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - NAPQI GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - NAPQI GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum

MS/MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 10V, Positive-QTOFsplash10-0udi-0900000000-ac4176497e66953d40c02017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 20V, Positive-QTOFsplash10-0pb9-0900000000-742d4824d6c715e26f222017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 40V, Positive-QTOFsplash10-002f-9000000000-6e485c18c7bf55922b572017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 10V, Negative-QTOFsplash10-0002-0900000000-2a0e88975df639fa01542017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 20V, Negative-QTOFsplash10-0a4j-0900000000-d205478121975decd1e62017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 40V, Negative-QTOFsplash10-0a4i-5900000000-069af19709609ef10b8d2017-10-06Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 10V, Positive-QTOFsplash10-0zfr-0900000000-7770a7a758395a5aeeee2021-10-12Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 20V, Positive-QTOFsplash10-0a59-4900000000-c817f1a34bce822d981d2021-10-12Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 40V, Positive-QTOFsplash10-0a59-9500000000-1dabf7d69b9d1c2251142021-10-12Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 10V, Negative-QTOFsplash10-0002-0900000000-d32a0a3b410ab42005862021-10-12Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 20V, Negative-QTOFsplash10-0002-0900000000-017594813fe14d2bf2a92021-10-12Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - NAPQI 40V, Negative-QTOFsplash10-056r-9500000000-376138408404ae9cf5172021-10-12Wishart LabView Spectrum

IR Spectra

Spectrum TypeDescriptionDeposition DateSourceView
Predicted IR SpectrumIR Ion Spectrum (Predicted IRIS Spectrum, Adduct: [M+H]+)2023-02-04FELIX labView Spectrum
Predicted IR SpectrumIR Ion Spectrum (Predicted IRIS Spectrum, Adduct: [M+Na]+)2023-02-04FELIX labView Spectrum
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 IDNAPQI
MarkerDB IDNot Available
Good Scents IDNot Available
References
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General ReferencesNot Available