Detection and Sequence Identification of Dinucleotides Produced from N-Phosphoryl Alanine and Four Nucleosides by HPLC-ESI-MS/MS

The products of the model reaction between N‐(O,O‐diisopropyl phosphoryl) alanine (DIPP‐Ala) and four nucleosides (adenosine, uridine, cytidine and guanosine) were studied by HPLC‐ESI‐MS/MS. The results showed that different mononucleotides and dinucleotides were produced. The sequences of dinucleotides formed from the DIPP‐Ala and four nucleosides were identified. The results revealed that the c‐ions from backbone fragmentation of the dinucleotides could be considered as the sequence‐diagnostic ions. It was firstly testified that the diagnostic c‐ions in positive and negative modes could be applied to identify the sequence of dinucleotide products formed in the reaction system.