Photogeneration of superoxide by adriamycin and daunomycin. An electron spin resonance and spin trapping study.
The hydroxyl and superoxide anion spin adducts of DMPO and 4-MePyBN, respectively, were obtained during photoirradiation of adriamycin and daunomycin solutions with visible light. Ethanol and dimethyl sulfoxide did not scavenge hydroxyl radicals in the photoirradiated drug solutions. Furthermore, the hydroxyl-DMPO spin adduct is not formed in the photolysis of air-free drug solutions, indicating that hydroxyl radicals are not directly produced in the photochemical reactions. Instead, the observed hydroxyl-DMPO is formed from the decay of the superoxide anion-DMPO spin adduct. The mechanism for generating the superoxide anion radical appears to be a direct electron transfer from the photoexcited adriamycin and daunomycin to dissolved oxygen.
D003630:Daunorubicin / Q000378:metabolism*; D004317:Doxorubicin / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D010777:Photochemistry; D013050:Spectrometry, Fluorescence; D013481:Superoxides / Q000378:metabolism*
D013481:Superoxides; D004317:Doxorubicin; D003630:Daunorubicin