AFRRI Reports, July-September 1990
ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
Pagination or Media Count:
Vanadyl reacts with hydrogen peroxide forming hydroxyl radicals in a Fenton-like reaction. The hydroxyl radicals were spin trapped and identified using 5,5-dimethyl-1-pyrroline-N-oxide DMPO. The quantity of hydroxyl radicals spin trapped during the reaction between ferrous ion and hydrogen peroxide. Experiments in the presence of formate show that this hydroxyl radical scavenger effectively competes with DMPO preventing the formation of the DMPO-OH adduct. However, in experiments using ethanol as the hydroxyl radical scavenger it was not possible to completely prevent the formation of DMPO-OH. The formation of this additional DMPO-OH in the presence of ethanol does not depend on the concentration of dissolved oxygen, but does depend on the concentration of hydrogen peroxide added to the vanadyl solution. The results suggest that the additional DMPO-OH formed in the presence of ethanol originates from a vanadium V intermediate. This intermediate may oxidize DMPO leading to the formation of DMOP-O2 which rapidly decomposes forming DMPO-OH. Keywords Vanadium, Vanadyl, Hydroxyl radicals, ESR, Spin trapping.
- Inorganic Chemistry