Gas-phase fragmentation studies of cyclic oligo-β-(1→6)-D-glucosamines by electrospray ionization mass spectrometry using a hybrid high-resolution mass spectrometer

Abstract

Positive and negative ion high-resolution electrospray ionization mass spectra (MS and MS₂) of cyclooligo-β-(1→6)-D-glucosamines and cyclooligo-β-(1→6)-N-acetyl-D-glucosamines were acquired and interpret. It was shown that the cleavages of glycosidic bonds are the main processes in the decay of protonated and metallated molecules. In addition, elimination of the water molecules (and ammonia for cyclooligo-β-(1→6)-D-glucosamines) was observed along with other processes including the unknown skeletal rearrangement. A primary fragmentation of the negatively charged ions (deprotonated molecules) differed from that of the positively charged ones.