Detection of 2-deoxy-D-ribose radicals generated by the reaction with the hydroxyl radical using a rapid flow-ESR method

• Published in: Bioscience, biotechnology, and biochemistry Vol. 66; no. 4; pp. 847 - 852
• Main Authors: Ohashi, Y. (Shizuoka Univ. (Japan). Faculty of Science), Yoshioka, H
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.04.2002; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Biological and medical sciences; Cell metabolism, cell oxidation; Cell physiology; CHEMICAL REACTIONS; Deoxyribose - chemistry; deoxyribose radical; Electron Spin Resonance Spectroscopy - methods; ESR SPECTROSCOPY; flow ESR method; FREE RADICALS; Free Radicals - chemistry; Fundamental and applied biological sciences. Psychology; hydroxyl radical; Hydroxyl Radical - chemistry; HYDROXYLATION; Kinetics; mixing resonator; Models, Molecular; Molecular and cellular biology; Molecular Conformation; RIBOSE; Chemical analysis; Statistical analysis; Dielectric resonator; EPR spectrometry; Instrumentation; Detection; Hydroxyl; Free radical
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.66.847

ESR spectrum of the short-lived radicals derived from 2-deoxy-o-ribose by the reaction with the hydroxyl radical (HO*) was measured using a rapid flow method. A dielectric mixing resonator was used for the measurement, which made it possible to measure the highly sensitive, ESR spectra of the radicals with a lifetime of the order of milliseconds. A complex spectrum was obtained and the spectral simulation was done to show that it was the superposition of the signals due to five radicals (I-V). Three of them were those formed by the dehydrogenation with the HO* at C-l (I), C-3 (II), and C-4 (III) positions of the 2-deoxy-D-ribose molecule. The other two (IV and V) were carbonyl-conjugated radicals formed by the elimination of a water molecule from III and II. The results showed that dehydrogenation occurred randomly at the positions where hydroxyl groups are attached, but the most preferred position was C-3 and the radical position moved from C-3 to C-4 by the elimination of water molecule.