Comparative reactivity of medicinal gold(I) compounds with the cyclic peptide vasopressin and its diselenide analogue.

The reactions of the medicinal gold(I) compound auranofin and its strict analogues with vasopressin and its diselenide analogue were comparatively investigated by LC-electrospray MS/MS. Evidence is gained of the possible cleavage of the S-S and Se-Se bridges induced by Au(I) in the absence of reducing agents. We found that at high temperature (70 °C) the sulfur and selenium atoms are metallated with the preferential binding of gold to selenium, the reaction not taking place under physiological conditions (37 °C).