Mitomycin C radical cation studied by pulse radiolysis.
The formation of the radical cation of mitomycin C (MMC.+) was investigated in aqueous solution by a pulse radiolysis method using SO4.- species as one electron oxidizing agent. The spectroscopic and kinetic characteristics of MMC.+ transients were determined, namely: absorption maxima at 295, 400 and 500 nm, the corresponding molar extinction coefficients are [symbol: see text] 295 = 5.63 x 10(3) dm3 mol-1 cm-1, [symbol: see text] 400 = 2.9 x 10(3) dm3 mol-1 cm-1, [symbol: see text] 500 = 2.32 x 10(3) dm3 mol-1 cm-1; the rate constant for formation of MMC.+ is k = (1.2 +/- 0.2) x 10(10) dm3 mol-1 s-1 and for decay 2k = (4.6 +/- 0.4) x 10(8) dm-3 mol-1 s-1. Based on this fact it can be assumed that not only the well-known mitomycin C radical anion (semiquinone, MMC.-) is efficiently involved in the radiotherapy process, but in a given oxidation environment the MMC.+ species could also play a role in this respect.
Getoff
Nikola
N
Ludwig Boltzmann Institute for Radiation Chemistry and Radiation Biology, Institute of Theoretical Chemistry and Molecular Structure Biology, Althanstr, 14, A-1090 Vienna, Austria.
D002412:Cations / Q000737:chemistry; D004583:Electrons; D005609:Free Radicals / Q000737:chemistry; D016685:Mitomycin / Q000737:chemistry* / Q000528:radiation effects*; D010084:Oxidation-Reduction; D011675:Pulse Radiolysis / Q000379:methods; D013431:Sulfates / Q000737:chemistry
D002412:Cations; D005609:Free Radicals; D013431:Sulfates; D016685:Mitomycin