Record Information
Version2.0
Creation Date2012-07-30 14:55:13 -0600
Update Date2015-06-03 17:21:05 -0600
Secondary Accession Numbers
  • ECMDB21285
Identification
Name:Superoxide anion
Description:The superoxide ion, also known by the obsolete name hyperoxide, is a compound that contains the superoxide anion with the chemical formula O2-. The systematic name of the anion is dioxide. The superoxide anion is particularly important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature. With one unpaired electron, the superoxide ion is a free radical, and, like dioxygen, it is paramagnetic.; Because superoxide is toxic, nearly all organisms living in the presence of oxygen contain isoforms of the superoxide scavenging enzyme, superoxide dismutase, or SOD. SOD is an extremely efficient enzyme; it catalyzes the neutralization of superoxide nearly as fast as the two can diffuse together spontaneously in solution. Other proteins, which can be both oxidized and reduced by superoxide, have weak SOD-like activity (e.g. hemoglobin). Genetic inactivation ('knockout') of SOD produces deleterious phenotypes in organisms ranging from bacteria to mice and have provided important clues as to the mechanisms of toxicity of superoxide in vivo.; Superoxide is the anionic form O2. It is important as the product of the one-electron reduction of dioxygen (oxygen gas), which occurs widely in nature. With one unpaired electron, the superoxide ion is a free radical. It is also paramagnetic. The biological toxicity of superoxide is due to its capacity to inactivate iron-sulfur cluster containing enzymes (which are critical in a wide variety of metabolic pathways), thereby liberating free iron in the cell, which can undergo fenton-chemistry and generate the highly reactive hydroxyl radical. In its HO2 form, superoxide can also initiate lipid peroxidation of polyunsaturated fatty acids. It also reacts with carbonyl compounds and halogenated carbons to create toxic peroxy radicals. As such, superoxide is a main cause of oxidative stress.; Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to Methemoglobin.; Because superoxide is toxic, nearly all organisms living in the presence of oxygen contain isoforms of the superoxide scavenging enzyme, superoxide dismutase, or SOD. SOD is an extremely efficient enzyme; it catalyzes the neutralization of superoxide nearly as fast as the two can diffuse together spontaneously in solution. With one unpaired electron, the superoxide ion is a free radical and therefore paramagnetic.; In living organisms, superoxide dismutase protects the cell from the deleterious effects of superoxides.
Structure
Thumb
Synonyms:
  • (O2)
  • Dioxidanidyl
  • Dioxide(1)
  • Dioxide(1-)
  • Hyperoxid
  • Hyperoxide
  • O2
  • O2 free radical
  • O2-
  • O2.-
  • O2-
  • Peroxide radical
  • Superoxide
  • Superoxide anion
  • Superoxide anion radical
  • Superoxide radical
  • Superoxide radical anion
  • Superoxyde
Chemical Formula:O2
Weight:Average: 31.9988
Monoisotopic: 31.989829244
InChI Key:OUUQCZGPVNCOIJ-UHFFFAOYSA-M
InChI:InChI=1S/HO2/c1-2/h1H/p-1
CAS number:11062-77-4
IUPAC Name:oxidanidyloxidanyl
Traditional IUPAC Name:superoxide
SMILES:[O][O-]
Chemical Taxonomy
DescriptionThis compound belongs to the class of chemical entities known as non-metal superoxides. These are inorganic non-metallic compounds containing a superoxide as its largest oxoanion.
KingdomChemical entities
Super ClassInorganic compounds
ClassHomogeneous non-metal compounds
Sub ClassNon-metal oxoanionic compounds
Direct ParentNon-metal superoxides
Alternative Parents
Substituents
  • Non-metal superoxide
  • Inorganic oxide
Molecular FrameworkNot Available
External Descriptors
Physical Properties
State:Solid
Charge:-1
Melting point:Not Available
Experimental Properties:
PropertyValueSource
Predicted Properties
PropertyValueSource
logP-0.36ChemAxon
pKa (Strongest Acidic)5.8ChemAxon
pKa (Strongest Basic)-6.8ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count2ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area23.06 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity2.89 m3·mol-1ChemAxon
Polarizability1.67 Å3ChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Biological Properties
Cellular Locations:Cytoplasm
Reactions:
SMPDB Pathways:
Superoxide Radicals DegradationPW002053 Pw002053Pw002053 greyscalePw002053 simple
KEGG Pathways:Not Available
EcoCyc Pathways:
Concentrations
Not Available
Spectra
Spectra:
Spectrum TypeDescriptionSplash Key
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-001i-9000000000-a9a93dd42f2cfa0b34c4View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-001i-9000000000-a9a93dd42f2cfa0b34c4View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-001i-9000000000-a9a93dd42f2cfa0b34c4View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-9000000000-5e864878b295db174473View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-9000000000-5e864878b295db174473View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9000000000-5e864878b295db174473View in MoNA
References
References:
  • Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. Pubmed: 21097882
Synthesis Reference:Not Available
Material Safety Data Sheet (MSDS)Not Available
External Links:
ResourceLink
CHEBI ID18421
HMDB IDHMDB02168
Pubchem Compound ID5359597
Kegg IDC00704
ChemSpider ID4514331
WikipediaSuperoxide_anion
BioCyc IDSUPER-OXIDE
EcoCyc IDSUPER-OXIDE

Enzymes

General function:
Involved in superoxide dismutase activity
Specific function:
Destroys radicals which are normally produced within the cells and which are toxic to biological systems
Gene Name:
sodA
Uniprot ID:
P00448
Molecular weight:
23097
Reactions
2 superoxide + 2 H(+) = O(2) + H(2)O(2).
General function:
Involved in oxidoreductase activity
Specific function:
Can oxidize menadiol to menadione
Gene Name:
ygiN
Uniprot ID:
P0ADU2
Molecular weight:
11532
General function:
Involved in superoxide metabolic process
Specific function:
Destroys radicals which are normally produced within the cells and which are toxic to biological systems
Gene Name:
sodC
Uniprot ID:
P0AGD1
Molecular weight:
17681
Reactions
2 superoxide + 2 H(+) = O(2) + H(2)O(2).
General function:
Involved in superoxide dismutase activity
Specific function:
Destroys radicals which are normally produced within the cells and which are toxic to biological systems
Gene Name:
sodB
Uniprot ID:
P0AGD3
Molecular weight:
21266
Reactions
2 superoxide + 2 H(+) = O(2) + H(2)O(2).
General function:
Involved in catalase activity
Specific function:
Bifunctional enzyme with both catalase and broad- spectrum peroxidase activity. Displays also NADH oxidase, INH lyase and isonicotinoyl-NAD synthase activity
Gene Name:
katG
Uniprot ID:
P13029
Molecular weight:
80023
Reactions
Donor + H(2)O(2) = oxidized donor + 2 H(2)O.
2 H(2)O(2) = O(2) + 2 H(2)O.
General function:
Involved in catalase activity
Specific function:
Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide
Gene Name:
katE
Uniprot ID:
P21179
Molecular weight:
84162
Reactions
2 H(2)O(2) = O(2) + 2 H(2)O.

Transporters

General function:
Involved in transporter activity
Specific function:
Non-specific porin
Gene Name:
ompN
Uniprot ID:
P77747
Molecular weight:
41220
General function:
Involved in transporter activity
Specific function:
Uptake of inorganic phosphate, phosphorylated compounds, and some other negatively charged solutes
Gene Name:
phoE
Uniprot ID:
P02932
Molecular weight:
38922
General function:
Involved in transporter activity
Specific function:
OmpF is a porin that forms passive diffusion pores which allow small molecular weight hydrophilic materials across the outer membrane. It is also a receptor for the bacteriophage T2
Gene Name:
ompF
Uniprot ID:
P02931
Molecular weight:
39333
General function:
Involved in transporter activity
Specific function:
Forms passive diffusion pores which allow small molecular weight hydrophilic materials across the outer membrane
Gene Name:
ompC
Uniprot ID:
P06996
Molecular weight:
40368