Interaction of triplet-state nucleic acid bases with electroaffinic molecules in solution by laser flash photolysis
Interaction of triplet-state nucleic acid bases with electroaffinic molecules in solution by laser flash photolysis
复制标题
通过激光闪光光解作用使三重态核酸碱基与溶液中的亲电分子相互作用
DOI：
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
P. Wardman
中科院分区：
文献类型：
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作者：
T. J. Kemp;A. Parker;P. Wardman
由249.1 nm激光闪光光解产生的三重态胸苷、胸苷和尿嘧啶被一系列电亲合分子（包括放射增敏药物甲硝唑和米索硝唑）猝灭，猝灭速率与Rehm-Weller方程的预测符合令人满意的雅阁光电子转移。当观察到C（NO2）3-和galvinoxyl阴离子的光谱时，对于所选溶质中的两种，四硝基甲烷和galvinoxyl，证实了这种机制，表明净电子转移，C（NO2）3-的产率为0.69 ± 0.03（胸腺嘧啶）和0.40 ± 0.03（尿嘧啶），以及0.024 ± 0.002（胸腺嘧啶）Galvinoxyl阴离子为0.0135 ± 0.0005（尿嘧啶）。这些结果的光和辐射损伤的DNA和细胞系统的机制的影响进行了讨论。
Triplet-state thymine, thymidine, and uracil, generated by 249.1 nm laser flash photolysis, are quenched by a range of electroaffinic molecules, including the radiosensitising drugs metronidazole and misonidazole, at rates which accord satisfactorily with the predictions of the Rehm–Weller equation for photoelectron transfer. Such a mechanism is confirmed for two of the selected solutes, tetranitromethane and galvinoxyl, when the spectrum of C(NO2)3– and of galvinoxyl anion are observed, indicating net electron transfer with yields of 0.69 ± 0.03 (thymine) and 0.40 ± 0.03 (uracil) for C(NO2)3– and of 0.024 ± 0.002 (thymine) and 0.0135 ± 0.0005 (uracil) for galvinoxyl anion. The mechanistic implications of these results for photo- and radiation-damage to DNA and cellular systems are discussed.