Premium
Electron impact and methane, isobutane and ammonia chemical ionization mass spectra of peptide amides related to melanostatin (Pro‐Leu‐Gly‐NH 2 )
Author(s) -
Björkman Svea
Publication year - 1982
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200090802
Subject(s) - isobutane , electron ionization , methane , mass spectrum , chemical ionization , ammonia , chemistry , ionization , spectral line , organic chemistry , mass spectrometry , computational chemistry , chromatography , physics , ion , catalysis , astronomy
Eighteen peptide amides related to Melanostatin, Pro‐Leu‐Gly‐NH 2 , were studied by electron impact and methane, isobutane and ammonia chemical ionization mass spectrometry. In general the methane and isobutane chemical ionization spectra, which were qualitatively similar, gave more pertinent structural information than the electron impact spectra. In ammonia chemical ionization, both the peptide amides and their fragment ions reacted with unionized reagent gas to give protonated peptide amides together with some other fragments not observed in methane or isobutane chemical ionization. Moreover, a Melanostatin analogue containing a dehydroproline residue underwent aromatization and double bond reduction in chemical ionization, and the two reactions may possibly have been linked.