scholarly journals ESI-MSnstudy on the fragmentation of protonated cyclic-dipeptides

2009 ◽  
Vol 23 (3-4) ◽  
pp. 131-139 ◽  
Author(s):  
Yan-Chun Guo ◽  
Shu-Xia Cao ◽  
Xiang-Kun Zong ◽  
Xin-Cheng Liao ◽  
Yu-Fen Zhao
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
High Resolution Mass Spectrometry ◽  
Biological Activities ◽  
Fragmentation Pathway ◽  
Amino Acid Residues ◽  
Cyclic Dipeptides ◽  
Fragmentation Pathways ◽  
Potential Applications ◽  
Characteristic Fragment

Cyclic dipeptides are relatively simple compounds that can exhibit a great variety of important biological activities. The fragmentation pathways of protonated cyclic dipeptides have been studied by electrospray ionization multistage mass spectrometry (ESI-MSn). The mass spectra studies of the cyclic dipeptides showed that the cyclic dipeptides with the similar substituents, the side chains of amino acid residues at the diketopiperazine ring, followed the same fragmentation pathway. In the fragmentation spectra of protonated cyclic dipeptides, some characteristic fragment ions were observed and could be used to distinguish the cyclic dipeptides. The hydrogen/deuterium (H/D) exchange experiment and the high-resolution mass spectrometry (Q-TOF) were used to verify and rationalize the proposed fragmentation pathways. These observations may have some potential applications in the structural elucidation and interpretation of the mass spectra of homologous compounds.

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>

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.

Synthesis and characterization of a porphyrin-crown ether conjugate as a potential intermediate for drug delivery application

2020 ◽  
pp. A-G
Author(s):  
Maher Fathalla
Keyword(s):  
Mass Spectrometry ◽  
Drug Delivery ◽  
High Resolution Mass Spectrometry ◽  
Mesoporous Silica Nanoparticles ◽  
Synthesis And Characterization ◽  
Delivery Vehicle ◽  
Potential Applications ◽  
Resolution Mass ◽  
C Nmr

The development of synthetic strategies for functional building units plays a central role in supramolecular chemistry. Both porphyrin and crown ethers have attracted the attention of researchers worldwide owing to their unique properties. It is envisioned that the integration of the two molecules will result in hybrid materials with potential applications in many fields. In the present study, a new porphyrin derivative 3 appended with four 18-crown-6 (18C6) ether moieties was synthesized through the Suzuki-Miyaura coupling of boronic ester porphyrin 1 and 4-bromobenzo-18-crown-6 2 in 80% yield. Porphyrin 3 was fully characterized by 1H/[Formula: see text]C NMR spectroscopy and high resolution mass spectrometry. The tendency of the 18C6 to form host-guest complexes with ammonium cations was exploited to assemble cation responsive hybrid material of porphyrin 3 and ammonium immobilized mesoporous silica nanoparticles (MSNs). Furthermore, the potential application of the 3/MSNs conjugate as a cation-responsive drug delivery vehicle was investigated in solution by UV-vis and fluorescence spectroscopies.

Fast Atom Bombardment Mass Spectrometry of the Vitamin B12 Analogues Hydrogenobalamin and Cupribalamin

1984 ◽  
Vol 39 (2) ◽  
pp. 248-251 ◽  
Author(s):  
Lutz Grotjahn ◽  
Volker B. Koppenhagen ◽  
Ludger Ernst
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrum ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Metal Clusters ◽  
Cobalt Atom ◽  
Vitamin B ◽  
Metal Free ◽  
Characteristic Fragment ◽  
Fab Mass Spectra

Hydrogenobalam in (metal-free vitamin B12) and cupribalamin are characterized by their fast atom bombardment (FAB) mass spectra which show molecular ion and characteristic fragment ion peaks. These spectra and the high-resolution FAB mass spectrum of cobalamin (vitamin B12) show that the (M+H)+-CN-59 peak for the latter is due to loss of acetamide and not of the central cobalt atom. In the FAB mass spectrum of cupribalamin metal clusters are observed

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.

Mass Spectrometry of some Nuclear Substituted Styryl Ketones

1972 ◽  
Vol 50 (6) ◽  
pp. 871-879 ◽  
Author(s):  
P. J. Smith ◽  
J. R. Dimmock ◽  
W. G. Taylor
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Aromatic Substitution ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
Aliphatic Ketones ◽  
Decomposition Processes ◽  
Structure Formula ◽  
Related Compounds ◽  
Carbonyl Function

The mass spectra of a series of nuclear substituted styryl ketones with the structure[Formula: see text]and several relaTed compounds have been determined. The major fragmentation pathways include such processes as an aromatic substitution reaction occurring in the molecular ion as well as the McLafferty rearrangement. Only one of the two possible α-cleavages at the carbonyl function was observed. The major decomposition processes are outlined and compared with the recent results of a study on α,β-unsaturated aliphatic ketones. Mechanistic pathways are suggested for the formation of the major fragment ions.

scholarly journals High-Resolution Mass Spectrometry and Chemometrics for the Detailed Characterization of Short Endogenous Peptides in Milk By-Products

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6472
Author(s):  
Carmela Maria Montone ◽  
Sara Elsa Aita ◽  
Chiara Cavaliere ◽  
Andrea Cerrato ◽  
Aldo Laganà ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Biological Activities ◽  
Food Culture ◽  
Cheese Making ◽  
Milk Whey ◽  
Endogenous Peptides ◽  
High Resolution Mass ◽  
Resolution Mass

The process of cheese-making has long been part of human food culture and nowadays dairy represents a large sector of the food industry. Being the main byproduct of cheese-making, the revalorization of milk whey is nowadays one of the primary goals in alignment with the principles of the circular economy. In the present paper, a deep and detailed investigation of short endogenous peptides in milk and its byproducts (whole whey, skimmed whey, and whey permeate) was carried out by high-resolution mass spectrometry, with a dedicated suspect screening data acquisition and data analysis approach. A total of 79 short peptides was tentatively identified, including several sequences already known for their exerted biological activities. An unsupervised chemometric approach was then employed for highlighting the differences in the short peptide content among the four sets of samples. Whole and skimmed whey showed not merely a higher content of short bioactive peptides compared to whole milk, but also a peculiar composition of peptides that are likely generated during the process of cheese-making. The results clearly demonstrate that whey represents a valuable source of bioactive compounds and that the set-up of processes of revalorization of milk byproducts is a promising path in the obtention of high revenue-generating products from dairy industrial waste.

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