Production of Free Radicals in Reduced Glutathione and Penicillamine by Thermal Hydrogen Atoms and X-radiation

Abstract

Electron-spin-resonance spectroscopy was used to observe the free radicals induced in reduced penicillamine and reduced glutathione both by x-irradiation and bombardment by thermal hydrogen atoms. X-irradiation at 77°K indicated that free radicals were initially located on a-carbon atoms in both molecules. When irradiated penicillamine was gradually warmed, E.S.R. centres were completely transferred to sulphur at about 200°K. In the case of irradiated glutathione, however, 8 days at room temperature were required for transfer of E.S.R. centres to sulphur. Hydrogen-atom bombardment resulted in the formation of the organo-sulphur radical in both compounds without evidence of hydrogen abstraction from a-carbon atoms.

Adverse effect propensity: A new feature of Gulf War illness predicted by environmental exposures

“…(Perhaps not surprisingly given potential for mitochondrial injury and impaired antioxidant defenses, both pesticides 76 , 215 , 216 , 217 , 218 , 219 , 220 , 221 , 222 and radiation produce OS at least acutely. 39 , 41 , 66 , 96 , 98 , 99 , 100 , 101 , 105 , 107 , 109 , 210 , 223 , 224 , 225 , 226 , 227 , 228 , 229 , 230 , 231 , 232 , 233 , 234 , 235 , 236 , 237 , 238 , 239 , 240 , 241 , 242 , 243 , 244 , 245 , 246 , 247 , 248 , 249 , 250 , 251 , 252 , 253 , 254 , 255 , 256 )…”

The Reactions of Hydrogen Atoms in Aqueous Solutions: Thiols

“…The rates of H-atom reactions with a large number of species have been surveyed (1)(2)(3) and the effect of molecular structure on reactivity has been discussed (2,3). In reactions with sulfhydryl compounds, there is considerable evidence, based on esr studies (4,5) and kinetic data (S), the H-atoms attack the SH moiety exclusively. Two distinct steps in this attack have been supported (6-9) based on product analysis and material balance.…”

“…H + RSH -H2 + RS (4) H + RSH -H2S + R (5) Most determinations of the rate of H-atom attack on sulfhydryl compounds report the total rate constant (k4 + k5). It would seem that the relative rates of reactions 4 and 5 should also be of interest in determining the role of RSH compounds in radiation protection and damage studies since the products of these reactions would be expected to differ significantly in contributions to further damage.…”