scholarly journals IsoSearch: An Untargeted and Unbiased Metabolite and Lipid Isotopomer Tracing Strategy from HR-LC-MS/MS Datasets

2020 ◽  
Vol 3 (3) ◽  
pp. 54
Author(s):  
He Huang ◽  
Min Yuan ◽  
Phillip Seitzer ◽  
Susan Ludwigsen ◽  
John M. Asara
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Defense Mechanism ◽  
High Resolution Mass Spectrometry ◽  
Pentose Phosphate ◽  
Selected Reaction Monitoring ◽  
Reaction Monitoring ◽  
Triglyceride Accumulation ◽  
Pathway Inhibition ◽  
Mcf 7

Stable isotopic tracer analysis is a technique used to determine carbon or nitrogen atom incorporation into biological systems. A number of mass spectrometry based approaches have been developed for this purpose, including high-resolution tandem mass spectrometry (HR-LC-MS/MS), selected reaction monitoring (SRM) and parallel reaction monitoring (PRM). We have developed an approach for analyzing untargeted metabolomic and lipidomic datasets using high-resolution mass spectrometry with polarity switching and implemented our approach in the open-source R script IsoSearch and in Scaffold Elements software. Using our strategy, which requires an unlabeled reference dataset and isotope labeled datasets across various biological conditions, we traced metabolic isotopomer alterations in breast cancer cells (MCF-7) treated with the metabolic drugs 2-deoxy-glucose, 6-aminonicotinamide, compound 968, and rapamycin. Metabolites and lipids were first identified by the commercial software Scaffold Elements and LipidSearch, then IsoSearch successfully profiled the 13C-isotopomers extracted metabolites and lipids from 13C-glucose labeled MCF-7 cells. The results interpreted known models, such as glycolysis and pentose phosphate pathway inhibition, but also helped to discover new metabolic/lipid flux patterns, including a reactive oxygen species (ROS) defense mechanism induced by 6AN and triglyceride accumulation in rapamycin treated cells. The results suggest the IsoSearch/Scaffold Elements platform is effective for studying metabolic tracer analysis in diseases, drug metabolism, and metabolic engineering for both polar metabolites and non-polar lipids.

scholarly journals Parallel Reaction Monitoring-Based Quantification of Cannabinoids in Whole Blood

2020 ◽  
Vol 44 (6) ◽  
pp. 541-548 ◽  
Author(s):  
Timothée Joye ◽  
Christèle Widmer ◽  
Bernard Favrat ◽  
Marc Augsburger ◽  
Aurélien Thomas
Keyword(s):  
High Resolution ◽  
Whole Blood ◽  
Dynamic Range ◽  
High Resolution Mass Spectrometry ◽  
Selected Reaction Monitoring ◽  
Simple Liquid ◽  
Reaction Monitoring ◽  
Parallel Reaction ◽  
Intermediate Precision ◽  
Parallel Reaction Monitoring

Abstract Cannabis is the most consumed drug of abuse, making it the primary target for identification and quantification in human whole blood regarding forensic and clinical toxicology analyses. Among biological matrices, blood is the reference for toxicological interpretation. A highly sensitive and selective liquid chromatography (LC) hyphenated with high-resolution mass spectrometry (HRMS) was developed for the quantification of Δ9-tetrahydrocannabinol (THC), 11-hydroxytetrahydrocannabinol (THC-OH), 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) and cannabidiol (CBD). Those cannabinoids were extracted from 1 mL of whole blood by a simple liquid–liquid extraction (LLE) in acidic conditions. HRMS was performed on an Orbitrap-based instrument using its trapping capabilities and increased selectivity for parallel reaction monitoring (PRM) quantification in positive polarity with a negative polarity switching for THC-OH and THC-COOH. Although selected reaction monitoring (SRM) and PRM-targeted methods have similar performance in terms of linearity, dynamic range, precision and repeatability, Orbitrap-based PRM provides a higher specificity due to the use of high-resolution mode separating background ions from the targeted molecules. The method was fully validated according to guidelines set forth by the “Société Française des Sciences et des Techniques Pharmaceutiques” (SFSTP). Trueness was measured below 107% for all tested concentrations. Repeatability and intermediate precision were found to be lower than 12% while the assay was found to be linear in the concentration range of 0.4–20 ng/mL for THC, THC-OH and CBD and of 2–100 ng/mL for THC-COOH. Recovery (RE) and matrix effect (ME) ranged from 70.6 to 102.5% and from −40 to 6.6%, respectively. The validated method provides an efficient procedure for the simultaneous and rapid quantification of cannabinoids in PRM mode providing an alternative over classical SRM.

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>

Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quaternary Ammonium ◽  
High Resolution Mass Spectrometry ◽  
Food Products ◽  
Quaternary Ammonium Compounds ◽  
High Resolution Mass ◽  
Ammonium Compounds ◽  
Resolution Mass

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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