Synthesis and characterization of the selenium analog of glutathione disulfide.

We synthesized the selenium analog of glutathione disulfide by a liquid phase method and named it glutaselenone (i.e., gamma-L-glutamyl-L-selenocysteinylglycine) diselenide. The selenol of selenocysteine was protected by the p-methoxybenzyl group, which was removed by acidolysis with trifluoroacetic acid in the presence of thioanisol. The overall yield of the final product, glutaselenone diselenide, was about 9% based on the starting compound, Se-(p-methoxybenzyl)-L-selenocysteine. Glutaselenone diselenide showed a broad absorption band between 270 and 400 nm and circular dichroism bands around 270 nm (positive) and 330 nm (negative), which were attributable to diselenide bond.