Fragmentation pathways in the mass spectra of isomeric phenylazoxypyridine-N-oxides

1992 ◽  
Vol 70 (4) ◽  
pp. 1028-1032 ◽  
Author(s):  
Nigel J. Bunce ◽  
H. Stewart McKinnon ◽  
Randy J. Schnurr ◽  
Sam R. Keum ◽  
Erwin Buncel
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Reduction ◽  
Ion Source ◽  
Tandem Mass ◽  
Mass Spectral Fragmentation ◽  
Fragmentation Pathways ◽  
Mass Spectral

The mass spectral fragmentation pathways of a series of phenylazoxypyridine-N-oxides have been studied under electron impact conditions using tandem mass spectrometry. Besides simple C—N cleavages, the azoxypyridine-N-oxides undergo deep-seated rearrangements directly from the molecular ion. In addition, the spectra are complicated by a purely chemical reduction of the N—O functionalities that occurs in the ion source prior to ionization.

scholarly journals Mass Spectrometry of Bis-Quinolizidine Alkaloids: FAB-MS of Oxo-Substituted Sparteines

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Beata Jasiewicz ◽  
Elżbieta Wyrzykiewicz
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Collision Induced Dissociation ◽  
Quinolizidine Alkaloids ◽  
Positional Isomers ◽  
Mass Spectral Fragmentation ◽  
Fragmentation Pathways ◽  
Mass Spectral

The unpublished in the literature FAB mass spectral fragmentation of seven oxosparteines (i.e., 2-oxosparteine, 15-oxosparteine, 17-oxosparteine, 2,17-dioxosparteine, 2,13-dioxosparteine, 2-oxo-13-hydroxysparteine, and 2-oxo-17-hydroxysparteine) is investigated. Fragmentation pathways, elucidation of which was assisted by FAB/collision-induced dissociation (CID) mass spectra measurements, are discussed. The data obtained create the basis for distinguishing positional isomers.

Unrestrictive protein modification localization and quality control for open search of mass spectra

2018 ◽  
Author(s):  
Zhiwu An ◽  
Fuzhou Gong ◽  
Yan Fu
Keyword(s):  
Mass Spectrometry ◽  
Quality Control ◽  
Tandem Mass Spectrometry ◽  
Mass Spectra ◽  
Protein Modification ◽  
Software Tool ◽  
Tandem Mass ◽  
Simulation Data ◽  
Post Translational Modifications

We have developed PTMiner, a first software tool for automated, confident filtering, localization and annotation of protein post-translational modifications identified by open (mass-tolerant) search of large tandem mass spectrometry datasets. The performance of the software was validated on carefully designed simulation data. <br>

scholarly journals Fast atom bombardment mass spectra of the .BETA.-blocker nipradilol with nitrate ester group-tandem mass spectrometry (MS/MS) and B/E constant linked scanning.

1990 ◽  
Vol 38 (12) ◽  
pp. 3389-3394 ◽  
Author(s):  
Michiaki YONEDA ◽  
Kazuo TSUJIMOTO ◽  
Mamoru OHASHI ◽  
Masami SHIRATSUCHI ◽  
Yasushi OHKAWA ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Beta Blocker ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Ester Group ◽  
Tandem Mass ◽  
Nitrate Ester

Differentiation of the Isomeric o-(m- and p-) Nitro-(Chloro- and Bromo-)Benzyl-2,4-(and 2,1-) Disubstituted 2-Thiocytosinium Halides by Electron Impact Ionisation and Fast Atom Bombardment Mass Spectrometry

2009 ◽  
Vol 15 (4) ◽  
pp. 497-506 ◽  
Author(s):  
Tomasz Pospieszny ◽  
Elżbieta Wyrzykiewicz
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Collision Induced Dissociation ◽  
Mass Measurements ◽  
Fragmentation Pathways ◽  
Mass Spectral ◽  
Fragment Ions ◽  
Accurate Mass Measurements ◽  
Impact Ionisation

Electron ionisation (EI) and fast atom bombardment (FAB) mass spectral fragmentations of nine 2,4-(and 2,1-) disubstituted o-( m- and p-)nitro-(chloro- and bromo-)-2-thiocytosinium halides are investigated. Fragmentation pathways, whose elucidation is assisted by accurate mass measurements and metastable transitions [EI-mass spectrometry (MS)], as well as FAB/collision-induced dissociation (CID) mass spectra measurements are discussed. The correlations between the abundances of the (C11H10N4SO2)+1–3; (C11H10N3SCl)+4–6 and (C11H10N3SBr)+7–9 ions and the selected fragment ions (EI-MS), as well as (C18H16N5SO4)+1–3; (C18H16N3SCl2)+4–6 and (C18H16N3SBr2) + 7–9 ions and the selected ions (C7H6NO2)+1–3; (C7H6Cl)+ 4–6; (C7H6Br)+ 7–9 (FAB-MS) are discussed. The data obtained can be used for distinguishing isomers.

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