EPR studies of free-radical reactions of carboxyfullerenes

Carboxyfullerene is a class of water-soluble buckminsterfullerene with thre e malonic acids. Electron paramagnetic resonance (EPR) experiments are perf ormed to examine the capacity of carboxyfullerenes to scavenge reactive oxy gen species, methyl radicals and peroxyl radicals. Three types of reactions are reported: (1) reactions of (OH)-O-. and O-.(2)- with carboxyfullerenes with 5,5-dimethyl-1-pyrroline N-oxide as the trapping agent, (2) reaction of (CH3)-C-. with scavenging agents, and (3) reactions of lipid alkyl/perox yl radicals with carboxyfullerenes. The study enables one to evaluate the e fficacy of carboxyfullerene as a free-radical scavenger and an antioxidatan t.