Itälä Eero, Tanzer Katrin, Granroth Sari, Kooser Kuno, Denifl Stephan, Kukk Edwin
Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland.
Institut für Ionenphysik und Angewandte Physik and Center of Molecular Biosciences, Leopold Franzens Universität Innsbruck, Technikerstrasse 25, Innsbruck, 6020, Austria.
J Mass Spectrom. 2017 Nov;52(11):770-776. doi: 10.1002/jms.3979.
We present here the photofragmentation patterns of doubly ionized 4(5)-nitroimidazole and 1-methyl-5-nitroimidazole. The doubly ionized state was created by core ionizing the C 1s orbitals of the samples, rapidly followed by Auger decay. Due to the recent development of nitroimidazole-based radiosensitizing drugs, core ionization was selected as it represents the very same processes taking place under the irradiation with medical X-rays. In addition to the fragmentation patterns of the sample, we study the effects of methylation on the fragmentation patterns of nitroimidazoles. We found that methylation alters the fragmentation significantly, especially the charge distribution between the final fragments. The most characteristic feature of the methylation is that it effectively quenches the production of NO and NO , widely regarded as key radicals in the chemistry of radiosensitization by the nitroimidazoles.
我们在此展示了双电离的4(5)-硝基咪唑和1-甲基-5-硝基咪唑的光解离模式。通过对样品的C 1s轨道进行芯部电离来产生双电离态，随后迅速发生俄歇衰变。由于基于硝基咪唑的放射增敏药物的最新发展，选择芯部电离是因为它代表了在医用X射线照射下发生的相同过程。除了样品的解离模式外，我们还研究了甲基化对硝基咪唑解离模式的影响。我们发现甲基化显著改变了解离，特别是最终碎片之间的电荷分布。甲基化最显著的特征是它有效地抑制了NO和NO的产生，而NO和NO被广泛认为是硝基咪唑放射增敏化学中的关键自由基。
