Selenoneine

Selenoneine is a <a href="/facts/Selenium/k975NApC">selenium</a> containing <a href="/facts/Ergothioneine/I2GkztYN">ergothioneine</a> derivative where the selenium (Se) atom replaces a sulfur atom. It can be systematically named as (2-selenyl-Nα,Nα,Nα-trimethyl-L-histidine or 3-(2-hydroseleno-1H-imidazol-5-yl)-2-(trimethylammonio)propanoate).
It is found in the blood of <a href="/facts/Bluefin_tuna/P7bsmQDj">bluefin tuna</a>, and other sea dwelling animals like turtles, mackerel, <a href="/facts/Beluga_whale/tpbkuu5V">beluga</a>, and <a href="/facts/Giant_petrel/XjLRuMaM">giant petrels</a>. It is an antioxidant, combining with <a href="/facts/Reactive_oxygen_species/GpwSRugH">reactive oxygen species</a> and boosting the action of <a href="/facts/GPx1/CvyqBlyQ">GPx1</a>.
Selenoneine is produced by microorganisms using enzymes that form a selenium-carbon bond. Humans that eat fish have selenoneine in their blood. About half of selenium is in the form of selenoneine. Selenoneine inhibits <a href="/facts/Angiotensin-converting_enzyme/n6hlpyJh">angiotensin-converting enzyme</a>. In vertebrates, selenoneine is transported into cells using <a href="/facts/OCTN1/jhnDuT65">OCTN1</a>. Selenoneine reacts with <a href="/facts/Methyl_mercury/xxztUUIU">methyl mercury</a> to form a mercury tetraselenoate complex, which degrades to <a href="/facts/Tiemannite/4Kk3AVok">tiemannite</a>, a <a href="/facts/Mercury_selenide/9LXq7b8J">mercury selenide</a>. This is a mechanism used to detoxify mercury in marine vertebrates. A related derivative, Se-methylselenoneine is found in lesser quantities in mackerel, sardine and tuna.
In air selenoneine is easily oxidised to a dimer containing a diselenide bond (Se-Se).

Selenoneine open-in-new

Selenoneine