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Record Information
Version2.0
Creation Date2009-08-05 14:20:32 UTC
Update Date2014-12-24 20:26:08 UTC
Accession NumberT3D3549
Identification
Common NameNitrous acid
ClassSmall Molecule
DescriptionNitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts. It is prepared by adding any mineral acid to sodium nitrite and is used in chemical synthesis. Nitrite is a toxic compound known to cause methemoglobinemia. (3, 5)
Compound Type
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Nitrite
  • Non-Metal
  • Synthetic Compound
Chemical Structure
Thumb
Synonyms
Synonym
Dioxonitric acid
HNO2
hydrogen dioxonitrate(1-)
Hydroxidooxidonitrogen
Hyponitrite
Hyponitrous acid
Kyselina dusite
Nitrosyl hydroxide
Nitrous acid trans
[NO(OH)]
Chemical FormulaHNO2
Average Molecular Mass47.013 g/mol
Monoisotopic Mass47.001 g/mol
CAS Registry Number7782-77-6
IUPAC Namenitrous acid
Traditional Namenitrous acid
SMILESON=O
InChI IdentifierInChI=1S/HNO2/c2-1-3/h(H,2,3)
InChI KeyInChIKey=IOVCWXUNBOPUCH-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as non-metal nitrites. These are inorganic non-metallic compounds containing a nitrite as its largest oxoanion.
KingdomInorganic compounds
Super ClassHomogeneous non-metal compounds
ClassNon-metal oxoanionic compounds
Sub ClassNon-metal nitrites
Direct ParentNon-metal nitrites
Alternative Parents
Substituents
  • Non-metal nitrite
  • Inorganic nitrite
  • Inorganic oxide
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateLiquid
AppearancePale blue solution.
Experimental Properties
PropertyValue
Melting PointNot Available
Boiling PointNot Available
SolubilityNot Available
LogPNot Available
Predicted Properties
PropertyValueSource
logP0.17ChemAxon
pKa (Strongest Basic)-3.5ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area49.66 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity8.72 m³·mol⁻¹ChemAxon
Polarizability2.81 ųChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyView
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Negative (Annotated)splash10-0007-9000000000-9cf82c70d7bc0883ea95JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Negative (Annotated)splash10-0005-9000000000-e52588fd7e5b6989584dJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Negative (Annotated)splash10-0007-9000000000-891acfcb7562d9875939JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86JSpectraViewer
Toxicity Profile
Route of ExposureOral (3) ; inhalation (3)
Mechanism of ToxicityNitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. (1, 4)
MetabolismNitrites and their metabolites are excreted in the urine. (3)
Toxicity ValuesNot Available
Lethal Dose10 to 100 mg/kg for an adult human. (6)
Carcinogenicity (IARC Classification)Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). (2)
Uses/SourcesNitrous acid is used in chemical synthesis. (5)
Minimum Risk LevelNot Available
Health EffectsNitrite poisoning causes methemoglobinemia. Nitrites may cause pregnancy complications and developmental effects. They may also be carcinogenic. (3)
SymptomsNitrite poisoning causes methemoglobinemia. Symptoms include cyanosis, cardiac dysrhythmias and circulatory failure, and progressive central nervous system (CNS) effects. CNS effects can range from mild dizziness and lethargy to coma and convulsions. (3)
TreatmentMethemoglobinemia can be treated with supplemental oxygen and methylene blue 1% solution administered intravenously slowly over five minutes followed by IV flush with normal saline. Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. (4)
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDNot Available
PubChem Compound ID24529
ChEMBL IDNot Available
ChemSpider IDNot Available
KEGG IDC01818
UniProt IDNot Available
OMIM ID
ChEBI ID25567
BioCyc IDCPD-1541
CTD IDNot Available
Stitch IDNitrous acid
PDB IDNot Available
ACToR IDNot Available
Wikipedia LinkNitrous_acid
References
Synthesis ReferenceNot Available
MSDST3D3549.pdf
General References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. International Agency for Research on Cancer (2014). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. [Link]
  3. ATSDR - Agency for Toxic Substances and Disease Registry (2007). Case Studies in Environmental Medicine. Nitrate/Nitrite Toxicity. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  4. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
  5. Wikipedia. Nitrous acid. Last Updated 17 June 2009. [Link]
  6. International Programme on Chemical Safety (IPCS) INCHEM (1996). Poison Information Monograph for Nitrates and Nitrites. [Link]
Gene Regulation
Up-Regulated GenesNot Available
Down-Regulated GenesNot Available

Targets

General Function:
Oxygen transporter activity
Specific Function:
Involved in oxygen transport from the lung to the various peripheral tissues.
Gene Name:
HBA1
Uniprot ID:
P69905
Molecular Weight:
15257.405 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
Involved in oxygen transport from the lung to the various peripheral tissues.LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.Spinorphin: functions as an endogenous inhibitor of enkephalin-degrading enzymes such as DPP3, and as a selective antagonist of the P2RX3 receptor which is involved in pain signaling, these properties implicate it as a regulator of pain and inflammation.
Gene Name:
HBB
Uniprot ID:
P68871
Molecular Weight:
15998.34 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
Involved in oxygen transport from the lung to the various peripheral tissues.
Gene Name:
HBD
Uniprot ID:
P02042
Molecular Weight:
16055.41 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
The epsilon chain is a beta-type chain of early mammalian embryonic hemoglobin.
Gene Name:
HBE1
Uniprot ID:
P02100
Molecular Weight:
16202.71 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
Gamma chains make up the fetal hemoglobin F, in combination with alpha chains.
Gene Name:
HBG1
Uniprot ID:
P69891
Molecular Weight:
16140.37 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Gamma chains make up the fetal hemoglobin F, in combination with alpha chains.
Specific Function:
Heme binding
Gene Name:
HBG2
Uniprot ID:
P69892
Molecular Weight:
16126.35 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
Not Available
Gene Name:
HBM
Uniprot ID:
Q6B0K9
Molecular Weight:
15617.97 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
Not Available
Gene Name:
HBQ1
Uniprot ID:
P09105
Molecular Weight:
15507.575 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]
General Function:
Oxygen transporter activity
Specific Function:
The zeta chain is an alpha-type chain of mammalian embryonic hemoglobin.
Gene Name:
HBZ
Uniprot ID:
P02008
Molecular Weight:
15636.845 Da
References
  1. Keszler A, Piknova B, Schechter AN, Hogg N: The reaction between nitrite and oxyhemoglobin: a mechanistic study. J Biol Chem. 2008 Apr 11;283(15):9615-22. doi: 10.1074/jbc.M705630200. Epub 2008 Jan 17. [18203719 ]
  2. Wikipedia. Methemoglobinemia. Last Updated 22 July 2009. [Link]