銅一過酸化水素系でのヒドロキシラジカル生成反応と該系における微生物の挙動 [in Japanese]
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Behavior of microorganisms in Cu(II)−H2O2 system were examined using DMPO as spin traps. In lower Cu(II)−H2O2−DMPO system (1 mM Cu), DMPO-OH derived from hydroxyl###radical-trapping was mainly observed. However, in higher Cu(II)−H2O2−DMPO system (4 mM Cu), most of DMPO-OH was derived from the nucleophillic addition of water molecule. Neutron irradiation of Cu(II) ion did not affect the DMPO-OH formation. Stable Cu(II) complex of phthalocyanin, which could produce 64Cu recoil atoms by neutron irradiation, did not generated DMPO-OH in Cu(II)−H2O2−DMPO system. Thus, the effects of microbial cells on hydroxyl radical generation were examined in lower Cu(II)−H2O2−DMPO system. ESR signal intensity of DMPO-OH in the system was heavily decreased by the addition of microbial cells. Its decrease effects were far larger than that in UV irradiated−H2O2−DMPO system. The microbial cells having higher ability to sorb copper showed relatively smaller ID50 values indicating the microbial amounts which decreased the signal intensities of DMPO-OH to half of###those in non-microbial. These results suggested that the generation of hydroxyl radical would be concerned with the strength of coupling between Cu(II) ion and microbial cells.
磁気共鳴と医学 (13), 47-50, 2002