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Resonant electron capture by aspartame and aspartic acid molecules
Author(s) -
Muftakhov M. V.,
Shchukin P. V.
Publication year - 2016
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7738
Subject(s) - chemistry , aspartame , aspartic acid , molecule , biomolecule , fragmentation (computing) , tripeptide , ion , decomposition , amino acid , electron ionization , mass spectrometry , mass spectrum , computational chemistry , organic chemistry , chromatography , biochemistry , computer science , ionization , operating system
Rationale The processes for dissociative electron capture are the key mechanisms for decomposition of biomolecules, proteins in particular, under interaction with low‐energy electrons. Molecules of aspartic acid and aspartame, i.e. modified dipeptides, were studied herein to define the impact of the side functional groups on peptide chain decomposition in resonant electron‐molecular reactions. Methods The processes of formation and decomposition of negative ions of both aspartame and aspartic acid were studied by mass spectrometry of negative ions under resonant electron capture. The obtained mass spectra were interpreted under thermochemical analysis by quantum chemical calculations. Results Main channels of negative molecular ions fragmentation were found and characteristic fragment ions were identified. Conclusions The СООН fragment of the side chain in aspartic acid is shown to play a key role like the carboxyl group in amino acids and aliphatic oligopeptides. Copyright © 2016 John Wiley & Sons, Ltd.