scholarly journals Quantification of Peptide m/z Distributions from 13C-Labeled Cultures with High-Resolution Mass Spectrometry

2014 ◽  
Vol 86 (3) ◽  
pp. 1894-1901 ◽  
Author(s):  
Doug K. Allen ◽  
Joshua Goldford ◽  
James K. Gierse ◽  
Dominic Mandy ◽  
Christine Diepenbrock ◽  
...  
2020 ◽  
Author(s):  
Jie Cheng ◽  
Yuchen Tang ◽  
Baoquan Bao ◽  
Ping Zhang

<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>


2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.


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