Photodynamic action of actinomycin D: an EPR spin trapping study.
Actinomycin D is one of the most widely studied anticancer antibiotic that binds to both double-stranded and single-stranded DNA, and this binding greatly enhances the DNA photosensitization. By use of electron paramagnetic resonance spin trapping techniques, both superoxide radical anion and the radical anion of actinomycin D were identified as important intermediates in the photodynamic process. A mechanism of electron transfer from a DNA base to excited actinomycin D was proposed. These novel findings may shed new light on future application of this drug in photodynamic therapy or cleavage of DNA in unique and controllable ways.
Pan
J X
JX
Laboratory of Radiation Chemistry, Shanghai Institute of Nuclear Research, Academia Sinica, China.
Liu
Y
Y
Zhang
S P
SP
Tu
T C
TC
Yao
S D
SD
Lin
N Y
NY
D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects* / Q000378:metabolism; D003609:Dactinomycin / Q000737:chemistry / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D004579:Electron Transport; D006801:Humans; D010778:Photochemotherapy
D000903:Antibiotics, Antineoplastic; D003609:Dactinomycin; D004247:DNA