Spontaneous generation of adriamycin semiquinone radicals at physiologic pH.
Adriamycin semiquinone radicals are spontaneously generated by adriamycin solutions at physiologic pH. Rate of radical formation and equilibrium-state radical yield increase with increasing pH from 7.4 to 8.85. The radicals are oxygen sensitive, but the mechanism of radical formation is oxygen independent and associated with proton removal from the dihydroquinone of adriamycin. The less cardiotoxic and non-mutagenic (Ames test) anthracycline 5-iminodaunorubicin does not form semiquinone radicals spontaneously at physiologic pH.
D000818:Animals; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000096:biosynthesis; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012996:Solutions
D012996:Solutions; C024703:adriamycin semiquinone radicals; D004317:Doxorubicin