Abstract

With NADPH as the electron donor, rat liver NADPH cytochrome P-450 reductase (NADPH:ferricytochrome oxidoreductase, EC 1.6.2.4) catalyzes the single-electron reduction of several quinone antibiotics to a semiquinone or free radical state. The benzanthraquinones adriamycin, daunorubicin, carminomycin, 7-O-methylnogalarol, and aclacinomycin A and the N-heterocyclic quinones streptonigrin and mitomycin C are activated to free radical intermediates which can transfer their single electron to molecular oxygen to form superoxide. The overall Km range for this electron transfer is 0.4 to 42.1 X 10(-4) M. We postulate that the formation of the "site-specific free radical/ intermediate is central to the cytotoxic action of these antibiotics.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.