Discovery of the strong antioxidant selenoneine in tuna and selenium redox metabolism

Figure 1 Chemical structure of ergothioneine and selenoneine. The monomeric form of the selenium compound is unstable under cold and room temperature conditions. The extracted material that contains the selenoketone of the selenium compound from the tuna tissues with acetonitrile/tetrahydrofuran (1:1 in volume) accelerates selenoxo-selenol tautomerization and formation of the oxidized dimeric form.