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Record Information
StatusDetected and Quantified
Creation Date2006-08-16 12:15:16 UTC
Update Date2020-10-09 21:00:12 UTC
Secondary Accession Numbers
  • HMDB00692
Metabolite Identification
Common NameFe2+
DescriptionIron is a chemical element with the symbol Fe and atomic number 26. Iron makes up 5% of the Earth's crust and is second in abundance to aluminium among the metals and fourth in abundance among the elements. Physiologically, it. exists as an ion in the body. Iron (as Fe2+, ferrous ion) is a necessary trace element used by all known living organisms. Iron-containing enzymes, usually containing heme prosthetic groups, participate in catalysis of oxidation reactions in biology, and in transport of a number of soluble gases. Iron is an essential constituent of hemoglobin, cytochrome, and other components of respiratory enzyme systems. Its chief functions are in the transport of oxygen to tissue (hemoglobin) and in cellular oxidation mechanisms. Inorganic iron involved in redox reactions is also found in the iron-sulfur clusters of many enzymes, such as nitrogenase (involved in the synthesis of ammonia from nitrogen and hydrogen) and hydrogenase. A class of non-heme iron proteins is responsible for a wide range of functions such as ribonucleotide reductase (reduces ribose to deoxyribose; DNA biosynthesis) and purple acid phosphatase (hydrolysis of phosphate esters). When the body is fighting a bacterial infection, the body sequesters iron inside of cells (mostly stored in the storage molecule ferritin) so that it cannot be used by bacteria. Depletion of iron stores may result in iron-deficiency anemia. Iron is used to build up the blood in anemia. Humans experience iron toxicity above 20 milligrams of iron for every kilogram of weight, and 60 milligrams per kilogram is a lethal dose. Over-consumption of iron, often the result of children eating large quantities of ferrous sulfate tablets intended for adult consumption, is the most common toxicological cause of death in children under six. The DRI lists the Tolerable Upper Intake Level (UL) for adults as 45 mg/day. For children under fourteen years old the UL is 40 mg/day. Iron is a metal extracted from iron ore, and is almost never found in the free elemental state.
FE (II) ionChEBI
Ferrous ionChEBI
Iron ion(2+)ChEBI
Armco ironHMDB
Carbonyl ironHMDB
Ferrovac eHMDB
Malleable ironHMDB
Suy-b 2HMDB
Wrought ironHMDB
Iron hydroxide (fe(OH)3)MeSH, HMDB
Iron oxyhydroxideMeSH, HMDB
Ferric hydroxideMeSH, HMDB
Iron hydroxide (III)MeSH, HMDB
Chemical FormulaFe
Average Molecular Weight55.845
Monoisotopic Molecular Weight55.934942133
IUPAC Namelambda2-iron(2+) ion
Traditional Namelambda2-iron(2+) ion
CAS Registry Number15438-31-0
InChI Identifier
Chemical Taxonomy
Description Belongs to the class of inorganic compounds known as homogeneous transition metal compounds. These are inorganic compounds containing only metal atoms,with the largest atom being a transition metal atom.
KingdomInorganic compounds
Super ClassHomogeneous metal compounds
ClassHomogeneous transition metal compounds
Sub ClassNot Available
Direct ParentHomogeneous transition metal compounds
Alternative ParentsNot Available
  • Homogeneous transition metal
Molecular FrameworkNot Available
External Descriptors
Physiological effect

Adverse health effect


Biological location


Route of exposure


Naturally occurring process

Physical Properties
Experimental Molecular Properties
Melting Point1538 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Experimental Spectral PropertiesNot Available
Predicted Molecular Properties
logP10(-0.77) g/LChemAxon
pKa (Strongest Acidic)4.58ChemAxon
Physiological Charge2ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity0 m³·mol⁻¹ChemAxon
Polarizability1.78 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleNoChemAxon
Predicted Spectral Properties

Predicted Kovats Retention Indices

Not Available
Biological Properties
Cellular Locations
  • Extracellular
  • Mitochondria
Biospecimen Locations
  • Blood
  • Cerebrospinal Fluid (CSF)
  • Saliva
  • Urine
Tissue Locations
  • Brain
  • Liver
Normal Concentrations
BloodDetected and Quantified9766 +/- 1246 uMAdult (>18 years old)Both
BloodDetected and Quantified8050.0 (7500.0-8600.0) uMAdult (>18 years old)Female
    • Geigy Scientific ...
BloodDetected and Quantified8950.0 (7900.0-10000.0) uMAdult (>18 years old)Male
    • Geigy Scientific ...
Cerebrospinal Fluid (CSF)Detected and Quantified3.6 +/- 3.6 uMElderly (>65 years old)BothNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified9.293 +/- 1.140 uMAdult (>18 years old)Not SpecifiedNormal details
Cerebrospinal Fluid (CSF)Detected and Quantified0.8 (0.3-0.5) uMAdult (>18 years old)BothNormal
    • Geigy Scientific ...
Cerebrospinal Fluid (CSF)Detected and Quantified0.783 +/- 0.551 uMAdult (>18 years old)FemaleNormal details
SalivaDetected and Quantified5.918 +/- 2.530 uMAdult (>18 years old)BothNormal
    • Zerihun T. Dame, ...
SalivaDetected and Quantified0.448-2.865 uMChildren (1-13 years old)BothNormal
    • Gian Paolo Sighin...
SalivaDetected and Quantified84.699 +/- 47.274 uMAdult (>18 years old)Male
SalivaDetected and Quantified80.759 +/- 38.141 uMAdult (>18 years old)Male
SalivaDetected and Quantified13286.776 +/- 7288.0294 uMChildren (1-13 years old)Both
SalivaDetected and Quantified18.605 +/- 1.726 uMChildren (1-13 years old)Not SpecifiedNormal details
SalivaDetected and Quantified5.551 +/- 1.253 uMAdult (>18 years old)Not SpecifiedNormal
    • Natheer H. Al-Raw...
UrineDetected and Quantified0.0890 (0.0025-0.4579) umol/mmol creatinineAdult (>18 years old)Both
UrineDetected and Quantified0.11 (0.0-0.14) umol/mmol creatinineAdult (>18 years old)BothNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
UrineDetected and Quantified0.029 (0.014-0.053) umol/mmol creatinineAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
Abnormal Concentrations
BloodDetected and Quantified8631 +/- 1497 uMAdult (>18 years old)Both
Multiple sclerosis
BloodDetected and Quantified20.1 +/- 7.7 uMAdult (>18 years old)BothParkinson's disease details
BloodDetected and Quantified16.3 +/- 7.7 uMElderly (>65 years old)BothAlzheimer's disease details
Cerebrospinal Fluid (CSF)Detected and Quantified0.488 +/- 0.374 uMAdult (>18 years old)Not Specifiedfibromyalgia details
Cerebrospinal Fluid (CSF)Detected and Quantified1.8 +/- 1.8 uMElderly (>65 years old)BothAlzheimer's disease details
Cerebrospinal Fluid (CSF)Detected and Quantified2.5 +/- 1.8 uMElderly (>65 years old)Not SpecifiedAlzheimer's disease details
SalivaDetected and Quantified45303.966 +/- 16295.103 uMChildren (1-13 years old)Both
Thalassemia Major
SalivaDetected and Quantified26877.966 +/- 10940.997 uMChildren (1-13 years old)Both
Thalassemia intermedia
SalivaDetected and Quantified18103.680 +/- 7370.400 uMAdolescent (13-18 years old)Both
Thalassemia Trait
SalivaDetected and Quantified4405.0497 +/- 1790.671 uMChildren (1-13 years old)Both
Iron Deficiency
SalivaDetected and Quantified24.008 +/- 6.984 uMChildren (1-13 years old)Not SpecifiedIron Deficiency details
SalivaDetected and Quantified33.172 +/- 8.529 uMChildren (1-13 years old)Not SpecifiedThalassemia Major details
SalivaDetected and Quantified40.971 +/- 9.292 uMChildren (1-13 years old)Not SpecifiedAplastic anemia details
SalivaDetected and Quantified2.507 +/- 0.537 uMAdult (>18 years old)Not SpecifiedOral squamous cell carcinoma
    • Natheer H. Al-Raw...
SalivaDetected and Quantified2.686 +/- 1.253 uMAdult (>18 years old)Not Specified
Oral squamous cell carcinoma
    • Natheer H. Al-Raw...
SalivaDetected and Quantified3.402 +/- 0.537 uMAdult (>18 years old)Not Specified
Oral squamous cell carcinoma
    • Natheer H. Al-Raw...
Associated Disorders and Diseases
Disease References
Multiple sclerosis
  1. Forte G, Visconti A, Santucci S, Ghazaryan A, Figa-Talamanca L, Cannoni S, Bocca B, Pino A, Violante N, Alimonti A, Salvetti M, Ristori G: Quantification of chemical elements in blood of patients affected by multiple sclerosis. Ann Ist Super Sanita. 2005;41(2):213-6. [PubMed:16244395 ]
Parkinson's disease
  1. Forte G, Alimonti A, Pino A, Stanzione P, Brescianini S, Brusa L, Sancesario G, Violante N, Bocca B: Metals and oxidative stress in patients with Parkinson's disease. Ann Ist Super Sanita. 2005;41(2):189-95. [PubMed:16244392 ]
Alzheimer's disease
  1. Molina JA, Jimenez-Jimenez FJ, Aguilar MV, Meseguer I, Mateos-Vega CJ, Gonzalez-Munoz MJ, de Bustos F, Porta J, Orti-Pareja M, Zurdo M, Barrios E, Martinez-Para MC: Cerebrospinal fluid levels of transition metals in patients with Alzheimer's disease. J Neural Transm (Vienna). 1998;105(4-5):479-88. [PubMed:9720975 ]
  2. Bocca B, Forte G, Petrucci F, Pino A, Marchione F, Bomboi G, Senofonte O, Giubilei F, Alimonti A: Monitoring of chemical elements and oxidative damage in patients affected by Alzheimer's disease. Ann Ist Super Sanita. 2005;41(2):197-203. [PubMed:16244393 ]
  1. Ortancil O, Sanli A, Eryuksel R, Basaran A, Ankarali H: Association between serum ferritin level and fibromyalgia syndrome. Eur J Clin Nutr. 2010 Mar;64(3):308-12. doi: 10.1038/ejcn.2009.149. Epub 2010 Jan 20. [PubMed:20087382 ]
Iron deficiency
  1. Canatan D, Akdeniz SK: Iron and ferritin levels in saliva of patients with thalassemia and iron deficiency anemia. Mediterr J Hematol Infect Dis. 2012;4(1):e2012051. doi: 10.4084/MJHID.2012.051. Epub 2012 Aug 9. [PubMed:22973495 ]
  2. Mishra OP, Agarwal KN, Agarwal RM: Salivary iron status in children with iron deficiency and iron overload. J Trop Pediatr. 1992 Apr;38(2):64-7. [PubMed:1569637 ]
Associated OMIM IDs
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDFDB030855
KNApSAcK IDNot Available
Chemspider ID25394
KEGG Compound IDC14818
BioCyc IDFE%2b2
BiGG ID33552
Wikipedia LinkIron
METLIN IDNot Available
PubChem Compound27284
ChEBI ID29033
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB IDMDB00000221
Good Scents IDNot Available
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Gal S, Fridkin M, Amit T, Zheng H, Youdim MB: M30, a novel multifunctional neuroprotective drug with potent iron chelating and brain selective monoamine oxidase-ab inhibitory activity for Parkinson's disease. J Neural Transm Suppl. 2006;(70):447-56. [PubMed:17017567 ]
  2. Piga A, Galanello R, Forni GL, Cappellini MD, Origa R, Zappu A, Donato G, Bordone E, Lavagetto A, Zanaboni L, Sechaud R, Hewson N, Ford JM, Opitz H, Alberti D: Randomized phase II trial of deferasirox (Exjade, ICL670), a once-daily, orally-administered iron chelator, in comparison to deferoxamine in thalassemia patients with transfusional iron overload. Haematologica. 2006 Jul;91(7):873-80. [PubMed:16818273 ]
  3. Nasolodin VV, Zaitseva IP, Gladkikh IP, Voronin SM: [Correction of iron and immune deficiencies in students from a higher humanitarian educational establishment]. Gig Sanit. 2005 Sep-Oct;(5):64-7. [PubMed:16277000 ]
  4. Custodio PJ, Carvalho ML, Nunes F, Pedroso S, Campos A: Direct analysis of human blood (mothers and newborns) by energy dispersive X-ray fluorescence. J Trace Elem Med Biol. 2005;19(2-3):151-8. Epub 2005 Oct 24. [PubMed:16325530 ]
  5. Agarwal MB: Exjade (ICL 670): A new oral iron chelator. J Assoc Physicians India. 2006 Mar;54:214-7. [PubMed:16800349 ]
  6. Cortese S, Konofal E, Lecendreux M, Mouren MC, Bernardina BD: Restless legs syndrome triggered by heart surgery. Pediatr Neurol. 2006 Sep;35(3):223-6. [PubMed:16939866 ]
  7. Barkova EN, Nazarenko EV, Zhdanova EV: Diurnal variations in qualitative composition of breast milk in women with iron deficiency. Bull Exp Biol Med. 2005 Oct;140(4):394-6. [PubMed:16671562 ]
  8. Christoforidis A, Haritandi A, Tsitouridis I, Tsatra I, Tsantali H, Karyda S, Dimitriadis AS, Athanassiou-Metaxa M: Correlative study of iron accumulation in liver, myocardium, and pituitary assessed with MRI in young thalassemic patients. J Pediatr Hematol Oncol. 2006 May;28(5):311-5. [PubMed:16772883 ]
  9. Kom GD, Schwedhelm E, Nielsen P, Boger RH: Increased urinary excretion of 8-iso-prostaglandin F2alpha in patients with HFE-related hemochromatosis: a case-control study. Free Radic Biol Med. 2006 Apr 1;40(7):1194-200. Epub 2005 Dec 13. [PubMed:16545687 ]
  10. Gerlach M, Double KL, Youdim MB, Riederer P: Potential sources of increased iron in the substantia nigra of parkinsonian patients. J Neural Transm Suppl. 2006;(70):133-42. [PubMed:17017520 ]
  11. Jost PJ, Stengel SM, Huber W, Sarbia M, Peschel C, Duyster J: Very severe iron-deficiency anemia in a patient with celiac disease and bulimia nervosa: a case report. Int J Hematol. 2005 Nov;82(4):310-1. [PubMed:16298820 ]
  12. St Pierre TG, Clark PR, Chua-Anusorn W: Measurement and mapping of liver iron concentrations using magnetic resonance imaging. Ann N Y Acad Sci. 2005;1054:379-85. [PubMed:16339686 ]
  13. Clardy SL, Earley CJ, Allen RP, Beard JL, Connor JR: Ferritin subunits in CSF are decreased in restless legs syndrome. J Lab Clin Med. 2006 Feb;147(2):67-73. [PubMed:16459164 ]
  14. Grosse R, Lund U, Caruso V, Fischer R, Janka GE, Magnano C, Engelhardt R, Durken M, Nielsen P: Non-transferrin-bound iron during blood transfusion cycles in beta-thalassemia major. Ann N Y Acad Sci. 2005;1054:429-32. [PubMed:16339692 ]
  15. Anderson LJ, Westwood MA, Prescott E, Walker JM, Pennell DJ, Wonke B: Development of thalassaemic iron overload cardiomyopathy despite low liver iron levels and meticulous compliance to desferrioxamine. Acta Haematol. 2006;115(1-2):106-8. [PubMed:16424659 ]
  16. Matinaho S, Karhumaki P, Parkkinen J: Bicarbonate inhibits the growth of Staphylococcus epidermidis in platelet concentrates by lowering the level of non-transferrin-bound iron. Transfusion. 2005 Nov;45(11):1768-73. [PubMed:16271102 ]
  17. Blanck HM, Cogswell ME, Gillespie C, Reyes M: Iron supplement use and iron status among US adults: results from the third National Health and Nutrition Examination Survey. Am J Clin Nutr. 2005 Nov;82(5):1024-31. [PubMed:16280434 ]
  18. Yarali N, Fisgin T, Duru F, Kara A, Ecin N, Fitoz S, Erden I: Subcutaneous bolus injection of deferoxamine is an alternative method to subcutaneous continuous infusion. J Pediatr Hematol Oncol. 2006 Jan;28(1):11-6. [PubMed:16394886 ]
  19. Walter PB, Fung EB, Killilea DW, Jiang Q, Hudes M, Madden J, Porter J, Evans P, Vichinsky E, Harmatz P: Oxidative stress and inflammation in iron-overloaded patients with beta-thalassaemia or sickle cell disease. Br J Haematol. 2006 Oct;135(2):254-63. [PubMed:17010049 ]
  20. Kontoghiorghes GJ, Kolnagou A: Molecular factors and mechanisms affecting iron and other metal excretion or absorption in health and disease: the role of natural and synthetic chelators. Curr Med Chem. 2005;12(23):2695-709. [PubMed:16305466 ]

Only showing the first 10 proteins. There are 191 proteins in total.


General function:
Involved in 5-aminolevulinate synthase activity
Specific function:
Not Available
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Uniprot ID:
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General function:
Involved in metabolic process
Specific function:
Catalyzes the release of fatty acids from phospholipids. It has been implicated in normal phospholipid remodeling, nitric oxide-induced or vasopressin-induced arachidonic acid release and in leukotriene and prostaglandin production. May participate in fas mediated apoptosis and in regulating transmembrane ion flux in glucose-stimulated B-cells. Has a role in cardiolipin (CL) deacylation. Required for both speed and directionality of monocyte MCP1/CCL2-induced chemotaxis through regulation of F-actin polymerization at the pseudopods. Isoform ankyrin-iPLA2-1 and isoform ankyrin-iPLA2-2, which lack the catalytic domain, are probably involved in the negative regulation of iPLA2 activity.
Gene Name:
Uniprot ID:
Molecular weight:
General function:
Involved in hydrolase activity
Specific function:
Involved in osteopontin/bone sialoprotein dephosphorylation. Its expression seems to increase in certain pathological states such as Gaucher and Hodgkin diseases, the hairy cell, the B-cell, and the T-cell leukemias.
Gene Name:
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General function:
Involved in oxidation reduction
Specific function:
Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides.
Gene Name:
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Molecular weight:
General function:
Involved in oxidoreductase activity
Specific function:
Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides. Inhibits Wnt signaling.
Gene Name:
Uniprot ID:
Molecular weight:
General function:
Involved in oxidation reduction
Specific function:
Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) that is believed to belong to the minimal assembly required for catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone (By similarity).
Gene Name:
Uniprot ID:
Molecular weight:
General function:
Involved in NADH dehydrogenase activity
Specific function:
Accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I), that is believed not to be involved in catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone
Gene Name:
Uniprot ID:
Molecular weight:
General function:
Involved in oxidoreductase activity, acting on NADH or NADPH
Specific function:
Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) that is believed to belong to the minimal assembly required for catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone (By similarity).
Gene Name:
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General function:
Involved in succinate dehydrogenase activity
Specific function:
Membrane-anchoring subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q).
Gene Name:
Uniprot ID:
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General function:
Amino acid transport and metabolism
Specific function:
Flavoenzyme which catalyzes the oxidation of N(1)-acetylspermine to spermidine and is thus involved in the polyamine back-conversion. Can also oxidize N(1)-acetylspermidine to putrescine. Substrate specificity: N(1)-acetylspermine = N(1)-acetylspermidine > N(1),N(12)-diacylspermine >> spermine. Does not oxidize spermidine. Plays an important role in the regulation of polyamine intracellular concentration and has the potential to act as a determinant of cellular sensitivity to the antitumor polyamine analogs.
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General function:
Involved in calcium ion binding
Specific function:
Cotransporter which plays a role in lipoprotein, vitamin and iron metabolism, by facilitating their uptake. Binds to ALB, MB, Kappa and lambda-light chains, TF, hemoglobin, GC, SCGB1A1, APOA1, high density lipoprotein, and the GIF-cobalamin complex. The binding of all ligands required calcium. Serves as important transporter in several absorptive epithelia, including intestine, renal proximal tubules and embryonic yolk sac. Interaction with LRP2 mediates its trafficking throughout vesicles and facilitates the uptake of specific ligands like GC, hemoglobin, ALB, TF and SCGB1A1. Interaction with AMN controls its trafficking to the plasma membrane and facilitates endocytosis of ligands. May play an important role in the development of the peri-implantation embryo through internalization of APOA1 and cholesterol. Binds to LGALS3 at the maternal-fetal interface
Gene Name:
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Molecular weight:
General function:
Involved in transmembrane transport
Specific function:
Has been shown to act both as an intestinal proton- coupled high-affinity folate transporter and as an intestinal heme transporter which mediates heme uptake from the gut lumen into duodenal epithelial cells. The iron is then released from heme and may be transported into the bloodstream. Dietary heme iron is an important nutritional source of iron. Shows a higher affinity for folate than heme
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Only showing the first 10 proteins. There are 191 proteins in total.