Direct detection of superoxide anion generated in C60-photosensitized oxidation of NADH and an analogue by molecular oxygen
Direct detection of superoxide anion generated in C60-photosensitized oxidation of NADH and an analogue by molecular oxygen
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DOI：
10.1039/b206887g
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发表时间：
2002-01-01
期刊：
影响因子：
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通讯作者：
Miyata, N
中科院分区：
文献类型：
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作者：
Nakanishi, I;Ohkubo, K;Miyata, N
在 NADH（二氢烟酰胺腺嘌呤二核苷酸）和分子氧 (O-2) 存在下，聚（乙烯基吡咯烷酮）(PVP) 溶解的 C-60 在可见光照射下会形成超氧阴离子 (O-2(.-))。具有特征g(|)|的O-2(.-)的形成使用 77 K 低温 EPR 技术的直接观察证实了值为 2.18。在 O-2 存在下，C-60 和 1-苄基-1,4-二氢烟酰胺 (BNAH) 的 N-甲基-2-吡咯烷酮 (NMP) 溶液也观察到光诱导 O-2(.-) 形成，而形成了 C-60 自由基阴离子 (C-60(.-))在没有O-2的情况下，在其他相同的实验条件下。这些结果表明，BNAH对C-60进行光诱导电子转移还原时形成的C-60(2-)充当O-2的电子供体，在NMP中产生O-2(.-)。
Visible-light irradiation of poly( vinylpyrrolidone) (PVP)-solubilized C-60 in water in the presence of NADH (dihydronicotinamide adenine dinucleotide) and molecular oxygen (O-2) results in formation of superoxide anion (O-2(.-)). Formation of O-2(.-) having a characteristic g(|)| value of 2.18 was evidenced by the direct observation with use of a low-temperature EPR technique at 77 K. Photoinduced O-2(.-) formation was also observed for an N-methyl-2-pyrrolidone (NMP) solution of C-60 and 1-benzyl-1,4-dihydronicotinamide (BNAH) in the presence of O-2, whereas C-60 radical anion (C-60(.-)) was formed in the absence of O-2 under otherwise the same experimental conditions. These results suggest that C-60(2-) formed in the photoinduced electron-transfer reduction of C-60 by BNAH acts as an electron donor to O-2 to give O-2(.-) in NMP.