Pulse radiolysis studies of nitrofurans: chemical radiosensitization

Journal Article · Fri Nov 30 23:00:00 EST 1973 · Radiat. Res., v. 56, no. 3, pp. 428-440

DOI:https://doi.org/10.2307/3573714· OSTI ID:4355441

Greenstock, C L; Dunlop, I

The nitrofurans, which radiosensitize anoxic mammalian cells to the same degree as oxygen, were studied by pulse radiolysis. Nifuroxime, a colorless nitrofuran derivative, reacts rapidly in aqueous solution with both the primary species (e/sub aq, OH, H) and with free radicals and radical anions of nucleic acid components. amino acids and other biochemical substrates. The biochemical free radicals react with nifuroxime either by electron transfer oxidation or by radical-adduct formation. The rate constants for both types of reaction, and their respective efficiencies, have been determined by monitoring the yield and kinetics of formation of the nifuroxime electron-adduct absorption in the presence of different concertrations of various biochemical substrates. The electron-adducts of purines, pyrimidines and amino acids transfer electrons to nifuroxime at diffusion-controlled rates. Their corresponding neutral free radicals transfer electrons, an order of magnitude more slowly, in competition with radical-nifuroxime addition reactions which have rate constants approximates 10/sup 9/ M/sup-1/ sec/sup -1/. Electron transfer from the electron- adducts of less electron-affinic cellular radiosensitizers to nifuroxime and from nifuroxime to oxygen and other compounds of higher electron-affinity have also been observed. The relevance of these studies to mechanisms of chemical radiosensitization is discussed. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Pinawa, Manitoba
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-015374
• OSTI ID: 4355441
• Journal Information: Radiat. Res., v. 56, no. 3, pp. 428-440, Journal Name: Radiat. Res., v. 56, no. 3, pp. 428-440; ISSN RAREA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*FURANS-- RADIOLYSIS
*NITRO COMPOUNDS-- RADIOLYSIS
*RADIOSENSITIVITY-- CHEMICAL REACTION KINETICS
AMINO ACIDS
ANIMAL CELLS
AQUEOUS SOLUTIONS
ELECTRON TRANSFER
ELECTRONS
HYDROGEN
HYDROXYL RADICALS
N40300* --Chemistry--Radiation Chemistry
NUCLEIC ACIDS
PULSED IRRADIATION
PURINES
PYRIMIDINES
RADICALS
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
SOLVATED ELECTRONS RADIOSENSITIVITY EFFECTS