Ergothioneine is a naturally occurring amino acid and is a thiourea derivative of histidine, containing a sulfur atom on the imidazole ring.[1] This compound occurs in relatively few organisms, notably actinomycetota, cyanobacteria, and certain fungi.[2][3] Ergothioneine was discovered by Charles Tanret in 1909 and named after the ergot fungus from which it was first purified,[4] with its structure being determined in 1911.[5][6]

Ergothioneine
Names
Preferred IUPAC name
(2S)-3-(2-Sulfanylidene-2,3-dihydro-1H-imidazol-4-yl)-2-(trimethylazaniumyl)propanoate
Other names
L-Ergothioneine; (+)-Ergothioneine; Thiasine; Sympectothion; Ergothionine; Erythrothioneine; Thiolhistidinebetaine
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.007.131 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C9H15N3O2S/c1-12(2,3)7(8(13)14)4-6-5-10-9(15)11-6/h5,7H,4H2,1-3H3,(H2-,10,11,13,14,15)/t7-/m0/s1 checkY
    Key: SSISHJJTAXXQAX-ZETCQYMHSA-N checkY
  • InChI=1/C9H15N3O2S/c1-12(2,3)7(8(13)14)4-6-5-10-9(15)11-6/h5,7H,4H2,1-3H3,(H2-,10,11,13,14,15)/t7-/m0/s1
    Key: SSISHJJTAXXQAX-ZETCQYMHBA
  • C[N+](C)(C)C(CC1=CNC(=S)N1)C(=O)[O-]
  • S=C1N\C(=C/N1)C[C@@H](C([O-])=O)[N+](C)(C)C
Properties
C9H15N3O2S
Molar mass 229.30 g/mol
Appearance white solid
Melting point 275 to 277 °C (527 to 531 °F; 548 to 550 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

In humans, ergothioneine is acquired exclusively through the diet and accumulates in erythrocytes, bone marrow, liver, kidney, seminal fluid, and eyes.[7] Although the effect of ergothioneine in vivo is under preliminary research, its physiological role in humans is unknown.[7] Ergothioneine is sold as a dietary supplement.[8]

Metabolism and sources

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Ergothioneine has been found in bacteria, plants, and animals, sometimes at millimolar levels.[9] Foods found to contain ergothioneine include liver, kidney, black beans, kidney bean, and oat bran, with the highest levels in bolete and oyster mushrooms.[9][10] Levels can be variable, even within species and some tissues can contain much more than others. In the human body, the largest amounts of ergothioneine are found in erythrocytes, eye lens, semen,[6] and skin.[11]

Although many species contain ergothioneine, only a few make it; the others absorb it from their diet or, in the case of plants, from their environment.[12] Biosynthesis has been detected in Actinomycetota, such as Mycobacterium smegmatis and certain fungi, such as Neurospora crassa.[2]

The metabolic pathway to produce ergothioneine starts with the methylation of histidine to produce histidine betaine (hercynine). The sulfur atom is then incorporated from cysteine.[9][13] The biosynthetic genes of ergothioneine have been described in Mycobacterium smegmatis,[14] Neurospora crassa,[15] and Schizosaccharomyces pombe.[16]

Other species of bacteria, such as Bacillus subtilis, Escherichia coli, Proteus vulgaris, and Streptococcus, as well as fungi in the Saccharomycotina cannot make ergothioneine.[17][18]

Structure

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Ergothioneine is a thiourea derivative of the betaine of histidine and contains a sulfur atom bonded to the 2-position of the imidazole ring.[19] Typical of thioureas, ergothioneine is less reactive than typical thiols such as glutathione towards alkylating agents like maleimides. It also resists oxidation by air.[9] However, ergothioneine can be slowly oxidized over several days to the disulfide form in acidic solutions.[20]

Ergothioneine derivatives

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Various derivatives of ergothioneine have been reported in the literature, such as S-methyl-ergothioneine[21] or selenium-containing selenoneine.[22]

Characteristics

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  • Adaptogenic Antioxidant: Ergothioneine is an adaptogenic antioxidant that preferentially accumulates in cells and tissues exposed to oxidative stress and damage. The organic cation transporter OCTN1 (now known as SLC22A4, a transporter protein with 551 amino acids and three glycosylation sites) in the human body can transport ergothioneine to where it is needed.[23]
  • Regenerative Pathway: The human body has a regenerative pathway for ergothioneine. When ergothioneine combines with glutathione, it can regenerate, allowing it to react with singlet oxygen in a cyclical manner, achieving a more comprehensive and lasting antioxidant effect.
  • Slow Excretion: Ergothioneine is excreted very slowly in the body, allowing it to be highly retained in the tissues and red blood cells of humans and other animals, thereby maximizing its effectiveness.
  • Stable Form: Ergothioneine mainly exists in the form of thione, which has ideal thermal stability and pH stability.

Preliminary research

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Although potential effects of ergothioneine are under preliminary research, its physiological role in vivo has not been determined.[1][7]

Safe intake levels

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The Panel on Dietetic Products for the European Food Safety Authority reported safe daily limits of 2.82 mg/kg of body weight for infants, 3.39 mg/kg for small children, and 1.31 mg/kg for adults, including pregnant and breastfeeding women.[8]

See also

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References

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  1. ^ a b "Ergothioneine". PubChem, National Center for Biotechnology Information, US National Library of Medicine. 2 November 2019. Retrieved 7 November 2019.
  2. ^ a b Fahey RC (2001). "Novel thiols of prokaryotes". Annual Review of Microbiology. 55: 333–56. doi:10.1146/annurev.micro.55.1.333. PMID 11544359.
  3. ^ Pfeiffer C, Bauer T, Surek B, Schömig E, Gründemann D (2011). "Cyanobacteria produce high levels of ergothioneine". Food Chemistry. 129 (4): 1766–1769. doi:10.1016/j.foodchem.2011.06.047.
  4. ^ Tanret, C. (1909). "Sur une base nouvelle retirée du seigle ergoté : l'ergothioneine". Comptes rendus hebdomadaires des séances de l'Académie des sciences (in French). 149: 222-224.
  5. ^ Barger, G.; Erwins, A.J. (1911). "The constitution of ergothioneine : a betaine related to histidine". Journal of the Chemical Society, Transactions. 99: 2336–2341. doi:10.1039/CT9119902336.
  6. ^ a b Mann T, Leone E (January 1953). "Studies on the metabolism of semen. VIII. Ergothioneine as a normal constituent of boar seminal plasma; purification and crystallization; site of formation and function". The Biochemical Journal. 53 (1): 140–8. doi:10.1042/bj0530140. PMC 1198115. PMID 13032046.
  7. ^ a b c Cheah, Irwin K.; Halliwell, Barry (2021-01-26). "Ergothioneine, recent developments". Redox Biology. 42: 101868. doi:10.1016/j.redox.2021.101868. ISSN 2213-2317. PMC 8113028. PMID 33558182.
  8. ^ a b Turck D, Bresson JL, Burlingame B, Dean T, Fairweather-Tait S, Heinonen M, et al. (November 2017). "Statement on the safety of synthetic l-ergothioneine as a novel food - supplementary dietary exposure and safety assessment for infants and young children, pregnant and breastfeeding women". EFSA Journal. 15 (11): e05060. doi:10.2903/j.efsa.2017.5060. PMC 7010164. PMID 32625352.
  9. ^ a b c d Ey J, Schömig E, Taubert D (August 2007). "Dietary sources and antioxidant effects of ergothioneine". Journal of Agricultural and Food Chemistry. 55 (16): 6466–74. doi:10.1021/jf071328f. PMID 17616140.
  10. ^ Kalač P. Edible Mushrooms. Chapter 4 - Health-Stimulating Compounds and Effects. pp 137-153. Academic Press, 2016. ISBN 9780128044551 doi:10.1016/B978-0-12-804455-1.00004-7
  11. ^ Markova NG, Karaman-Jurukovska N, Dong KK, Damaghi N, Smiles KA, Yarosh DB (April 2009). "Skin cells and tissue are capable of using L-ergothioneine as an integral component of their antioxidant defense system". Free Radical Biology & Medicine. 46 (8): 1168–76. doi:10.1016/j.freeradbiomed.2009.01.021. PMID 19439218.
  12. ^ Audley BS, Tan CH (1968). "The uptake of ergothioneine from the soil into the latex of Hevea brasiliensis". Phytochemistry. 7 (11): 1999–2000. Bibcode:1968PChem...7.1999A. doi:10.1016/S0031-9422(00)90759-3.
  13. ^ Melville DB, Ludwig ML, Inamine E, Rachele JR (May 1959). "Transmethylation in the biosynthesis of ergothionelne". The Journal of Biological Chemistry. 234 (5): 1195–8. doi:10.1016/S0021-9258(18)98157-3. PMID 13654346.[permanent dead link]
  14. ^ Seebeck FP (May 2010). "In vitro reconstitution of Mycobacterial ergothioneine biosynthesis". Journal of the American Chemical Society. 132 (19): 6632–3. doi:10.1021/ja101721e. PMID 20420449.
  15. ^ Bello MH, Barrera-Perez V, Morin D, Epstein L (February 2012). "The Neurospora crassa mutant NcΔEgt-1 identifies an ergothioneine biosynthetic gene and demonstrates that ergothioneine enhances conidial survival and protects against peroxide toxicity during conidial germination". Fungal Genetics and Biology. 49 (2): 160–72. doi:10.1016/j.fgb.2011.12.007. PMID 22209968.
  16. ^ Pluskal T, Ueno M, Yanagida M (2014). "Genetic and metabolomic dissection of the ergothioneine and selenoneine biosynthetic pathway in the fission yeast, S. pombe, and construction of an overproduction system". PLOS ONE. 9 (5): e97774. Bibcode:2014PLoSO...997774P. doi:10.1371/journal.pone.0097774. PMC 4020840. PMID 24828577.
  17. ^ Genghof DS (August 1970). "Biosynthesis of ergothioneine and hercynine by fungi and Actinomycetales". Journal of Bacteriology. 103 (2): 475–8. doi:10.1128/JB.103.2.475-478.1970. PMC 248105. PMID 5432011.
  18. ^ Genghof DS, Inamine E, Kovalenko V, Melville DB (November 1956). "Ergothioneine in microorganisms". The Journal of Biological Chemistry. 223 (1): 9–17. doi:10.1016/S0021-9258(18)65113-0. PMID 13376573.[permanent dead link]
  19. ^ Hartman PE (1990). "[32] Ergothioneine as antioxidant". Oxygen Radicals in Biological Systems Part B: Oxygen Radicals and Antioxidants. Methods in Enzymology. Vol. 186. pp. 310–8. doi:10.1016/0076-6879(90)86124-E. ISBN 978-0-12-182087-9. PMID 2172707.
  20. ^ Heath H, Toennies G (February 1958). "The preparation and properties of ergothioneine disulphide". The Biochemical Journal. 68 (2): 204–10. doi:10.1042/bj0680204. PMC 1200325. PMID 13522601.
  21. ^ Asmus KD, Bensasson RV, Bernier JL, Houssin R, Land EJ (April 1996). "One-electron oxidation of ergothioneine and analogues investigated by pulse radiolysis: redox reaction involving ergothioneine and vitamin C". The Biochemical Journal. 315 (2): 625–9. doi:10.1042/bj3150625. PMC 1217242. PMID 8615839.
  22. ^ Yamashita Y, Yamashita M (June 2010). "Identification of a novel selenium-containing compound, selenoneine, as the predominant chemical form of organic selenium in the blood of bluefin tuna". The Journal of Biological Chemistry. 285 (24): 18134–8. doi:10.1074/jbc.C110.106377. PMC 2881734. PMID 20388714.
  23. ^ Halliwell, Barry; Cheah, Irwin K.; Tang, Richard M. Y. (October 2018). "Ergothioneine – a diet‐derived antioxidant with therapeutic potential". FEBS Letters. 592 (20): 3357–3366. doi:10.1002/1873-3468.13123. ISSN 0014-5793.
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