| 229.3 g/mol|
Ergothioneine is a naturally occurring amino acid and is a thiourea derivative of histidine, containing a sulfur atom on the imidazole ring. This compound is made in relatively few organisms, notably Actinobacteria, Cyanobacteria, and certain fungi. Ergothioneine was discovered in 1909 and named after the ergot fungus from which it was first purified, with its structure being determined in 1911.
In vitro assays, as well as in vivo animal models, are used in basic research to identify its potential biological properties.
In humans, ergothioneine is acquired exclusively through the diet and accumulates in erythrocytes, bone marrow, liver, kidney, seminal fluid and eyes. Ergothioneine requires a specific transporter, ETT, also known as OCTN1 (gene symbol SLC22A4), to enter cells. ETT expression has been confirmed in human and animal cell lines and its functional transport of ergothioneine has been observed in preliminary studies in vivo. Although the effect of ergothioneine in vivo is an active area of research, its physiological role in humans is undetermined.
Ergothioneine is a thiourea derivative of the betaine of histidine and contains a sulfur atom bonded to the 2-position of the imidazole ring. This compound is unusual since the sulfur atom is most stable in solution in the thione form, rather than the sulfhydryl, in contrast to the structurally related ovothiol. This makes ergothioneine much less reactive than thiols such as glutathione towards alkylating agents like maleimides, and also prevents the compound from oxidizing in air. However, ergothioneine can be slowly oxidized over several days to the disulfide form in acidic solutions. If ergothioneine does become oxidized, the disulfide is a very strong oxidizing agent, so this will in turn rapidly oxidize other thiols in the cell such as glutathione.
Various derivatives of ergothioneine have been reported in the literature, such as S-methyl-ergothioneine or selenium-containing selenoneine.
Ergothioneine has antioxidant properties in vitro. Under laboratory conditions, it scavenges hydroxyl radicals and hypochlorous acid, inhibits production of oxidants by metal ions, and may participate in metal ion transport and regulation of metalloenzymes.
Although potential effects of ergothioneine are under preliminary research, its physiological role in vivo is unknown.