A study of fragmentation of protonated amides of some acylated amino acids by tandem mass spectrometry: observation of an unusual nitrilium ion
作者:Erach R. Talaty、Sarah M. Young、Ryan P. Dain、Michael J. Van Stipdonk
DOI:10.1002/rcm.4965
日期:2011.5.15
ionization (ESI) was conducted. Among the fragment ions observed was an unusual one, which we have determined to be a nitrilium ion having the structure or by loss of the full mass of glycine as a neutral fragment. A mechanism that we propose involves an initial protonation of the oxygen atom at the N‐terminus, followed by cyclization to a five‐membered imidazolium ring, and its subsequent collapse to