A mechanism for the oxidation of glutathione to glutathione disulfide with organotellurium(IV) and organoselenium(IV) compounds. A stepwise process with implications for photodynamic therapy and other oxidative chemotherapy

Kinetic studies of the oxidation of glutathione to glutathione disulfide by organotellurium compounds reveal the involvement of two discrete steps, a fast reaction and a slow reaction, in the oxidation. Kinetic data enable the determination of second-order rate constants for both fast and slow reactions. Formation of tellurium(II) compound accompanies the slow reaction. Organoselenium(IV) compounds also exhibit this oxidation behavior, but the rate constants for both steps are significantly lower than those of tellurium analogues.