Zins Emilie-Laure, Rochut Sophie, Pepe Claude
Université Pierre et Marie Curie, Paris 6, Laboratoire de Dynamique, Interactions et Réactivité, CNRS, UMR 7075, Paris, France.
J Mass Spectrom. 2009 Jan;44(1):40-9. doi: 10.1002/jms.1468.
Cationized uracil clusters were generated in the gas phase by electrospray ionization (ESI). Mass spectrometry experiments showed that with particular experimental conditions, decameric uracil clusters are magic number clusters. MS/MS experiments demonstrated that the structure of these decameric uracil clusters depends substantially on the size and the charge of the cation. On the basis of the ab initio and density functional theory (DFT) quantum chemistry calculations, structures for these decameric clusters were proposed. These structures are in agreement with the experimental mass spectra of modified nucleobases. Theoretical calculations showed that complexes experimentally observed using ESI-MS techniques, are not naturally the most stable in the gas phase.
阳离子化尿嘧啶簇通过电喷雾电离（ESI）在气相中生成。质谱实验表明，在特定实验条件下，十聚体尿嘧啶簇是幻数簇。串联质谱（MS/MS）实验证明，这些十聚体尿嘧啶簇的结构在很大程度上取决于阳离子的大小和电荷。基于从头算和密度泛函理论（DFT）量子化学计算，提出了这些十聚体簇的结构。这些结构与修饰核碱基的实验质谱一致。理论计算表明，使用ESI-MS技术实验观察到的配合物在气相中并非天然最稳定。
