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Record Information
Creation Date2009-03-06 18:58:10 UTC
Update Date2014-12-24 20:21:13 UTC
Accession NumberT3D0147
Common NameSelenium
ClassSmall Molecule
DescriptionSelenium is a nonmetal element with the atomic number 34 and the chemical symbol Se. Isolated selenium occurs in several different forms, the most stable of which is a dense purplish-gray semiconductor form. Selenium rarely occurs in its elemental state in nature and is usually found in sulfide ores such as pyrite, partially replacing the sulfur in the ore matrix. It may also be found in silver, copper, lead, and nickel minerals. Selenium is mainly used in the electronics industry, in glassmaking, and in chemicals and pigments. Though selenium salts are toxic in large amounts, trace amounts of the element are necessary for cellular function in most animals, forming the active center of the enzymes glutathione peroxidase, thioredoxin reductase, and three known deiodinase enzymes. (30)
Compound Type
  • Cosmetic Toxin
  • Food Toxin
  • Household Toxin
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Metabolite
  • Natural Compound
  • Non-Metal
  • Pesticide
  • Pollutant
  • Selenium Compound
Chemical Structure
Selenium anion (2-)
Selenium ion (Se2-)
Chemical FormulaSe
Average Molecular Mass78.960 g/mol
Monoisotopic Mass79.915 g/mol
CAS Registry Number7782-49-2
IUPAC Nameselandiylium
Traditional Nameselandiylium
InChI IdentifierInChI=1S/Se/q+2
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as homogeneous other non-metal compounds. These are inorganic non-metallic compounds in which the largest atom belongs to the class of 'other non-metals'.
KingdomInorganic compounds
Super ClassHomogeneous non-metal compounds
ClassHomogeneous other non-metal compounds
Sub ClassNot Available
Direct ParentHomogeneous other non-metal compounds
Alternative ParentsNot Available
  • Homogeneous other non metal
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue Locations
  • Brain
  • Erythrocyte
  • Hair
  • Kidney
  • Liver
  • Muscle
  • Placenta
PathwaysNot Available
ApplicationsNot Available
Biological Roles
Chemical RolesNot Available
Physical Properties
AppearanceGray to black crystals.
Experimental Properties
Melting Point221°C
Boiling Point684.9°C (1264.8°F)
SolubilityNot Available
LogPNot Available
Predicted Properties
Physiological Charge2ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity13.11 m³·mol⁻¹ChemAxon
Polarizability1.78 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash KeyDeposition DateView
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-001i-9000000000-ad1e04375c75e553c27b2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-001i-9000000000-ad1e04375c75e553c27b2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-001i-9000000000-ad1e04375c75e553c27b2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-9000000000-d9ac578ecd68e91829fb2016-08-04View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-9000000000-d9ac578ecd68e91829fb2016-08-04View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9000000000-d9ac578ecd68e91829fb2016-08-04View Spectrum
Toxicity Profile
Route of ExposureOral(29) ; inhalation (29) ; dermal (29).
Mechanism of ToxicitySelenium readily substitutes for sulfur in biomolecules and in many biochemical reactions, especially when the concentration of selenium is high and the concentration of sulfur is low. Inactivation of the sulfhydryl enzymes necessary for oxidative reactions in cellular respiration, through effects on mitochondrial and microsomal electron transport, might contribute to acute selenium toxicity. Selenomethionine (a common organic selenium compound) also appears to randomly substitute for methionine in protein synthesis. This substitution may affect the structure and functionability of the protein, for example, by altering disulfide bridges. Inorganic forms of selenium appear to react with tissue thiols by redox catalysis, resulting in formation of reactive oxygen species and causing damage by oxidative stress. (29)
MetabolismSelenium may be absorbed through inhalation and ingestion, while some selenium compounds may also be absorbed dermally. Once in the body, selenium is distributed mainly to the liver and kidney. Selenium is an essential micronutrient and is a component of glutathione peroxidase, iodothyronine 5'-deiodinases, and thioredoxin reductase. Organic selenium is first metabolized into inorganic selenium. Inorganic selenium is reduced stepwise to the intermediate hydrogen selenide, which is either incorporated into selenoproteins after being transformed to selenophosphate and selenocysteinyl tRNA or excreted into the urine after being transformed into methylated metabolites of selenide. Elemental selenium is also methylated before excretion. Selenium is primarily eliminated in the urine and feces, but certain selenium compounds may also be exhaled. (29)
Toxicity ValuesLD50: 6700 mg/kg (Oral, Rat) (26)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)3, not classifiable as to its carcinogenicity to humans. (28)
Uses/SourcesMost processed selenium is used in the electronics industry, but it is also used as a nutritional supplement, in the glass industry, in the preparation of pharmaceuticals, as a nutritional feed additive for poultry and livestock, in pesticide formulations, in rubber production, as an ingredient in antidandruff shampoos, and as a constituent of fungicides. It may also be found in pigments in plastics, paints, enamels, inks, and rubber. (29)
Minimum Risk LevelChronic Oral: 0.005 mg/kg/day (27)
Health EffectsChronic oral exposure to high concentrations of selenium compounds can produce a disease called selenosis. The major signs of selenosis are hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities). Animal studies have shown that selenium may also affect sperm production and the female reproductive cycle. (29)
SymptomsShort-term oral exposure to high concentrations of selenium may cause nausea, vomiting, and diarrhea. Brief exposures to high levels of elemental selenium or selenium dioxide in air can result in respiratory tract irritation, bronchitis, difficulty breathing, and stomach pains. Longer-term exposure to either of these air-borne forms can cause respiratory irritation, bronchial spasms, and coughing. (29)
TreatmentNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
PubChem Compound ID107674
ChEMBL IDNot Available
ChemSpider ID27471292
UniProt IDNot Available
OMIM ID138319 , 138320 , 138321 , 138322 , 147892 , 176803 , 226600 , 229300 , 600902 , 601112 , 601148 , 601413 , 601484 , 603235 , 604188 , 604687 , 606210 , 606216 , 606218 , 606235 , 606254 , 606448 , 611056
ChEBI ID60871
BioCyc IDCPD0-1561
CTD IDD012643
Stitch IDSelenium
PDB IDNot Available
ACToR ID1291
Wikipedia LinkSelenium
Synthesis ReferenceZhu, Shihui; Zhu, Liu; Kaisuya, Romeo; Shou, Jianchuan. Apparatus and process for production of high purity selenium. Faming Zhuanli Shenqing Gongkai Shuomingshu (2007), 12pp.
General References
  1. Al-Kunani AS, Knight R, Haswell SJ, Thompson JW, Lindow SW: The selenium status of women with a history of recurrent miscarriage. BJOG. 2001 Oct;108(10):1094-7. [11702843 ]
  2. Karita K, Suzuki T: Fish eating and variations in selenium and mercury levels in plasma and erythrocytes in free-living healthy Japanese men. Biol Trace Elem Res. 2002 Winter;90(1-3):71-81. [12666827 ]
  3. Holben DH, Smith AM, Ilich JZ, Landoll JD, Holcomb JP, Matkovic V: Selenium intakes, absorption, retention, and status in adolescent girls. J Am Diet Assoc. 2002 Aug;102(8):1082-7. [12171452 ]
  4. Raghunath R, Tripathi RM, Mahapatra S, Sadasivan S: Selenium levels in biological matrices in adult population of Mumbai, India. Sci Total Environ. 2002 Feb 21;285(1-3):21-7. [11874044 ]
  5. Chuang IC, Lee PN, Lin TH, Chen GS: Determination of some elements in the cervical mucus of healthy Taiwanese women, by GF-AAS. Biol Trace Elem Res. 2002 May;86(2):137-43. [12008976 ]
  6. Dawson EB, Albers JH, McGanity WJ: The apparent effect of iron supplementation on serum selenium levels in teenage pregnancy. Biol Trace Elem Res. 2000 Dec;77(3):209-17. [11204463 ]
  7. Jablonska-Kaszewska I, Swiatkowska-Stodulska R, Lukasiak J, Dejneka W, Dorosz A, Dabrowska E, Falkiewicz B: Serum selenium levels in alcoholic liver disease. Med Sci Monit. 2003 Aug;9 Suppl 3:15-8. [15156604 ]
  8. Orhan H, Evelo CT, Sahin G: Erythrocyte antioxidant defense response against cigarette smoking in humans--the glutathione S-transferase vulnerability. J Biochem Mol Toxicol. 2005;19(4):226-33. [16173057 ]
  9. Spallholz JE, Boylan LM, Palace V, Chen J, Smith L, Rahman MM, Robertson JD: Arsenic and selenium in human hair: a comparison of five countries with and without arsenicosis. Biol Trace Elem Res. 2005 Aug;106(2):133-44. [16116245 ]
  10. Hac E, Krechniak J, Szyszko M: Selenium levels in human plasma and hair in northern Poland. Biol Trace Elem Res. 2002 Mar;85(3):277-85. [11934251 ]
  11. Wasowicz W, Gromadzinska J, Szram K, Rydzynski K, Cieslak J, Pietrzak Z: Selenium, zinc, and copper concentrations in the blood and milk of lactating women. Biol Trace Elem Res. 2001 Mar;79(3):221-33. [11354347 ]
  12. Burk RF, Hill KE: Selenoprotein P: an extracellular protein with unique physical characteristics and a role in selenium homeostasis. Annu Rev Nutr. 2005;25:215-35. [16011466 ]
  13. Karita K, Sasaki S, Ishihara J, Tsugane S: Validity of a self-administered food frequency questionnaire used in the 5-year follow-up survey of the JPHC Study to assess selenium intake: comparison with dietary records and blood levels. J Epidemiol. 2003 Jan;13(1 Suppl):S92-7. [12701635 ]
  14. Diaz Romero C, Lopez Blanco F, Henriquez Sanchez P, Rodriguez E, Serra Majem L: Serum selenium concentration in a representative sample of the Canarian population. Sci Total Environ. 2001 Mar 26;269(1-3):65-73. [11305344 ]
  15. Hawkes WC, Turek PJ: Effects of dietary selenium on sperm motility in healthy men. J Androl. 2001 Sep-Oct;22(5):764-72. [11545288 ]
  16. Wang Z, Liu S, Wang J: [Changes of selenium concentration in blood and placenta in intrahepatic cholestasis of pregnancy]. Zhonghua Fu Chan Ke Za Zhi. 2000 Aug;35(8):476-8. [11776202 ]
  17. Arnaud J, Malvy D, Richard MJ, Faure H, Chaventre A: Selenium status in an iodine deficient population of the West Ivory Coast. J Physiol Anthropol Appl Human Sci. 2001 Mar;20(2):81-4. [11385942 ]
  18. Van Dael P, Davidsson L, Ziegler EE, Fay LB, Barclay D: Comparison of selenite and selenate apparent absorption and retention in infants using stable isotope methodology. Pediatr Res. 2002 Jan;51(1):71-5. [11756642 ]
  19. Sun Y, Li HZ: Determination of trace selenium in human plasma and hair with ternary inclusion compound-fluorescent spectrophotometry. Analyst. 2000 Dec;125(12):2326-9. [11219076 ]
  20. Xu D, Ong C, Shen H: [The associations between concentration of selenium in semen and sperm parameters as well as oxidative DNA damage in human sperm]. Zhonghua Yu Fang Yi Xue Za Zhi. 2001 Nov;35(6):394-6. [11840768 ]
  21. Angstwurm MW, Gaertner R: Practicalities of selenium supplementation in critically ill patients. Curr Opin Clin Nutr Metab Care. 2006 May;9(3):233-8. [16607122 ]
  22. Kohrle J: Selenium and the control of thyroid hormone metabolism. Thyroid. 2005 Aug;15(8):841-53. [16131327 ]
  23. Lu J, Jiang C: Selenium and cancer chemoprevention: hypotheses integrating the actions of selenoproteins and selenium metabolites in epithelial and non-epithelial target cells. Antioxid Redox Signal. 2005 Nov-Dec;7(11-12):1715-27. [16356132 ]
  24. Richardson DR: More roles for selenoprotein P: local selenium storage and recycling protein in the brain. Biochem J. 2005 Mar 1;386(Pt 2):e5-7. [15720294 ]
  25. Hartikainen H: Biogeochemistry of selenium and its impact on food chain quality and human health. J Trace Elem Med Biol. 2005;18(4):309-18. [16028492 ]
  26. Lewis RJ (1996). Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold.
  27. ATSDR - Agency for Toxic Substances and Disease Registry (2001). Minimal Risk Levels (MRLs) for Hazardous Substances. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  28. International Agency for Research on Cancer (2014). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. [Link]
  29. ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  30. Wikipedia. Selenium. Last Updated 7 June 2009. [Link]
Gene Regulation
Up-Regulated Genes
GeneGene SymbolGene IDInteractionChromosomeDetails
Down-Regulated Genes
GeneGene SymbolGene IDInteractionChromosomeDetails