Electron transfer reaction in the radiation chemistry of some biologically important disulphlde compounds

It is found that some biologically important organic disulphides behave in an unique way under gamma irradiation when they are added in small amounts to the well-known Fricke dosimetry solution. On irradiation, it is noted that addition of these organic solutes reduces the G(Fe⁺² → Fe⁺³) yield instead of the usual increase found in the case of most other organic compounds. It is argued that these compounds behave as sacrificial radiation protective agents. The observation has been explained on the basis of an electron transfer reaction between the disulphides and OH radical. The resulting radical cations of these compounds then dissociate into non-chain propagating species. An attempt has been made to correlate the protective ability of such compounds towards (Fe⁺² → Fe⁺³) system with their biological radiation Drotective abilities. The electron transfer mechanism also seems to operate into their radiation protective action towards biological systems.