The Analysis of Photochemical Nitrile Imine Cross-Linking for Ribonucleosides in Gas-Phase Ions

Abstract

This research presents the exploration of nitrile imine cross-linking related to ribonucleoside ions in the gas phase. Riboguanosine was tagged with 4-(2-phenyl-2H-tetrazol-5-yl)benzoic acid at the 5’O-ribose position. The tagged nucleosides were analyzed by liquid chromatography mass spectrometry (LC-MS) and tandem mass spectrometry including ultraviolet photodissociation tandem mass spectrometry (UVPD-MS) and collision-induced dissociation tandem mass spectrometry (CID-MS). Crosslinking was found to occur in tetrazole-guanosine ions upon N2 loss under CID-MS2 and UVPD-MS2. The spectra from CID-MS3 and UVPD-CID-MS3 also suggested that the cross-linking involved interactions between the guanine carbonyl group and the nitrile imine.