Mass Spectrometry in Structural and Stereochemical Problems. XLI.1Isotope Effect in Hydrogen Rearrangement Processes: The Mass Spectra of Methyl Butyrate and Its γ-Mono-, Di-, and Trideuterio Analogs

1964 ◽  
Vol 86 (2) ◽  
pp. 284-287 ◽  
Author(s):  
D. H. Williams ◽  
H. Budzikiewicz ◽  
Carl. Djerassi
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Methyl Butyrate ◽  
Rearrangement Processes ◽  
Hydrogen Rearrangement

Mass Spectrometry of N-Benzoyl-2-hydroxyalkylamines. Role of the Hydroxylic Hydrogen in the Fragmentation Pattern

1975 ◽  
Vol 53 (21) ◽  
pp. 3175-3187 ◽  
Author(s):  
Don C. DeJongh ◽  
Denis C. K. Lin ◽  
Pierre LeClair-Lanteigne ◽  
Denis Gravel
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Relative Importance ◽  
Hydrogen Atoms ◽  
Related Compounds ◽  
Double Hydrogen ◽  
Hydrogen Rearrangement

An interesting rearrangement has been observed in the mass spectra of a series of N-benzoyl-2-hydroxyalkylamines. The hydrogen atom of the hydroxyl group is transferred to the N-benzoyl portion of the molecular ion and the bond between positions 1 and 2 in the N-alkyl group is cleaved. A rearrangement ion, observed at m/e 135, is formed along with a neutral aldehyde or ketone. When the hydroxylic hydrogen is replaced by a trimethylsilyl substituent, the latter group is transferred with comparable efficiency. Differences in the relative importance of this rearrangement in the mass spectra of a series of related compounds with decreasing substitution at position 2, have been explained by differences in the stabilities of the neutral molecules formed along with m/e 135 and by the occurrence of a double hydrogen rearrangement which competes if hydrogen atoms are present in a relationship gamma and delta to the carbonyl group.

Electron impact studies. XXXI. Skeletal-rearrangement fragments in the mass spectra of anils

1968 ◽  
Vol 21 (8) ◽  
pp. 2021 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
JW Fisher ◽  
T McL Spotswood
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Electron Impact ◽  
Mass Spectra ◽  
General Type ◽  
High Resolution Mass Spectrometry ◽  
Aromatic Aldehydes ◽  
Skeletal Rearrangement ◽  
Rearrangement Processes ◽  
Resolution Mass

Skeletal-rearrangement fragments are observed in the mass spectra of all anils derived from aromatic aldehydes. The rearrangement processes have been studied by high-resolution mass spectrometry and in certain cases by deuterium labelling. All processes are of the general type [ABC]+ → [AC]+ +B.

Studies in Mass Spectrometry. II. Random Hydrogen Rearrangement in Aromatic Molecular Ions

1962 ◽  
Vol 15 (4) ◽  
pp. 771 ◽  
Author(s):  
CG Macdonald ◽  
JS Shannon
Keyword(s):  
Mass Spectrometry ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Mass Spectrometric ◽  
Deuterium Exchange ◽  
Molecular Ion ◽  
Hydrogen Rearrangement ◽  
Aromatic Hydrogen

To provide data for investigations by, inter alia, mass-spectrometric methods into the deuterium exchange of the aromatic hydrogen of some coal fractions, a study was made which confirmed the occurrence of completely random hydrogen rearrangement prior to or during the elimination of C2H2 in the molecular ions of benzene-1,2,3-d3, benzene-l,3,5-d3, naphthalene-1,2,3,4-d4, naphthalene-1,4,5,8-d4, and phenanthrene-9,10-d2, and in the phenyl ions derived from o-bromobenzene-d, m-bromobenzene-d, and p-chlorobenzene-d, Similar but incomplete hydrogen rearrangement was found to occur in the molecular ion of carbazole-N-d prior to or during elimination of HCN. Such rearrangements, for which mechanistic considerations are presented, must be taken into account when the mass spectra of deuterium-substituted aromatic compounds are being interpreted.

Exploring the Active Compounds of Traditional Mongolian Medicine Agsirga in Intervention of Novel Coronavirus (2019-nCoV) Based on HPLC-Q-Exactive-MS/MS and Molecular Docking Method

2020 ◽  
Author(s):  
Jie Cheng ◽  
Yuchen Tang ◽  
Baoquan Bao ◽  
Ping Zhang
Keyword(s):  
Mass Spectrometry ◽  
Molecular Docking ◽  
High Resolution ◽  
Mass Spectra ◽  
High Resolution Mass Spectrometry ◽  
Structural Formula ◽  
Active Compounds ◽  
High Resolution Mass ◽  
Q Exactive ◽  
Resolution Mass

<p><a></a><a></a><a></a><a><b>Objective</b></a>: To screen all compounds of Agsirga based on the HPLC-Q-Exactive high-resolution mass spectrometry and find potential inhibitors that can respond to 2019-nCoV from active compounds of Agsirga by molecular docking technology.</p> <p><b>Methods</b>: HPLC-Q-Exactive high-resolution mass spectrometry was adopted to identify the complex components of Mongolian medicine Agsirga, and separated by the high-resolution mass spectrometry Q-Exactive detector. Then the Orbitrap detector was used in tandem high-resolution mass spectrometry, and the related molecular and structural formula were found by using the chemsipider database and related literature, combined with precise molecular formulas (errors ≤ 5 × 10<sup>−6</sup>) , retention time, primary mass spectra, and secondary mass spectra information, The fragmentation regularities of mass spectra of these compounds were deduced. Taking ACE2 as the receptor and deduced compounds as the ligand, all of them were pretreated by discover studio, autodock and Chem3D. The molecular docking between the active ingredients and the target protein was studied by using AutoDock molecular docking software. The interaction between ligand and receptor is applied to provide a choice for screening anti-2019-nCoV drugs.</p> <p><b>Result</b>: Based on the fragmentation patterns of the reference compounds and consulting literature, a total of 96 major alkaloids and stilbenes were screened and identified in Agsirga by the HPLC-Q-Exactive-MS/MS method. Combining with molecular docking, a conclusion was got that there are potential active substances in Mongolian medicine Agsirga which can block the binding of ACE2 and 2019-nCoV at the molecular level.</p>

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>

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