Itälä Eero, Myllynen Hanna, Niskanen Johannes, González-Vázquez Jesús, Wang Yang, Ha Dang Trinh, Denifl Stephan, Kukk Edwin
Department of Physics and Astronomy , University of Turku , Turku FI-20014 , Finland.
Departamento de Química, Módulo 13 , Universidad Autónoma de Madrid , 28049 Madrid , Spain.
J Phys Chem A. 2019 Apr 11;123(14):3074-3079. doi: 10.1021/acs.jpca.8b11342. Epub 2019 Mar 29.
Nitroimidazole exhibits a remarkable regioselective fragmentation subsequent to valence ionization, which is characterized by ejection of NO. As NO is also considered to be an effective radiosensitizer, we investigated its production efficiency as a function of isomeric composition (the site of the NO nitro group). We observe strong dependence in the 8.6-15 eV binding energy range, and moreover, that the production of NO can be effectively suppressed by methylation of nitroimidazole. This behavior can be understood by modification of the valence electronic structure with respect to the dissociation threshold, which gives rise to varying effective density of dissociative states. We find the NO yield to follow the efficiency of the nitroimidazole dervivatives as radiosensitizers, found in preclinical studies.
硝基咪唑在价态电离后表现出显著的区域选择性碎片化，其特征是一氧化氮（NO）的逸出。由于NO也被认为是一种有效的放射增敏剂，我们研究了其作为异构体组成（NO硝基的位置）函数的产生效率。我们观察到在8.6 - 15电子伏特结合能范围内有强烈的依赖性，此外，硝基咪唑的甲基化可以有效抑制NO的产生。这种行为可以通过相对于解离阈值对价电子结构的修饰来理解，这导致了不同的解离态有效密度。我们发现NO产率与临床前研究中发现的硝基咪唑衍生物作为放射增敏剂的效率一致。
