scholarly journals Application of Lipid Class Ratios for Sample Stability Monitoring—Evaluation of Murine Tissue Homogenates and SDS as a Stabilizer

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 277
Author(s):  
Sabrina Krautbauer ◽  
Raquel Blazquez ◽  
Gerhard Liebisch ◽  
Marcus Hoering ◽  
Philip Neubert ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Lipid Class ◽  
High Resolution Mass Spectrometry ◽  
Lipolytic Activity ◽  
Sodium Dodecyl ◽  
Lipid Profiles ◽  
Lipolytic Action ◽  
Sample Stability ◽  
Tissue Homogenates ◽  
The Stability

Lipids are a ubiquitous class of structurally complex molecules involved in various biological processes. In the fast-growing field of lipidomics, preanalytical issues are frequently neglected. Here, we investigated the stability of lipid profiles of murine liver, brain, lung, heart, and spleen homogenates by quantitative flow injection analysis using tandem mass spectrometry and high-resolution mass spectrometry. Storage of tissue homogenates at room temperature showed substantial alterations of the lipid profiles reflecting lipolytic action. Therefore, ratios of ceramide to sphingomyelin, lysophosphatidylethanolamine to phosphatidylethanolamine, lysophosphatidylcholine to phosphatidylcholine, and diglyceride to triglyceride were applied to monitor sample stability and the effect of sodium dodecyl sulfate (SDS) as a potential stabilizing agent. The addition of SDS led to a concentration-dependent stabilization of lipid profiles in liver, brain, and heart homogenates, while in lung and spleen homogenates, in particular, the lysophosphatidylethanolamine to phosphatidylethanolamine ratio increased upon addition of SDS. In conclusion, we demonstrated that lipid class ratios reflecting lipolytic activity could be applied to evaluate both the stability of samples and the influence of stabilizers.

scholarly journals The Copper(II) Ions Solvent Extraction with a New Compound: 2,6-Bis(4-Methoxybenzoyl)-Diaminopyridine

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 954 ◽  
Author(s):  
Daria Bożejewicz ◽  
Katarzyna Witt ◽  
Małgorzata A. Kaczorowska ◽  
Borys Ośmiałowski
Keyword(s):  
Mass Spectrometry ◽  
Solvent Extraction ◽  
High Resolution ◽  
Stability Constant ◽  
Tandem Mass Spectrometry ◽  
High Resolution Mass Spectrometry ◽  
Chloroform Solution ◽  
Tandem Mass ◽  
The Stability ◽  
Resolution Mass

A new compound 2,6-bis(4-methoxybenzoyl)-diaminopyridine (L) was used as an extractant for copper(II) ion recovery in a solvent extraction conducted at a temperature of 25 °C. The best results (99% recovery of copper(II) ions) were obtained when the aqueous phase contained 0.001 mol/dm3 Cu(II) and 0.2 mol/dm3 NH3 (pH~5.8), while the organic phase was a 0.001 mol/dm3 chloroform solution of 2,6-bis(4-methoxybenzoyl)-diaminopyridine. Spectrophotometry studies were used to determine the dissociation constant of the tested compound and determine the stability constant of the complex of subjected compound with copper(II) ions. The high-resolution mass spectrometry (HRMS) and higher energy collisional dissociation tandem mass spectrometry (HCD MS/MS) methods have been applied for the confirmation of the structure of 2,6-bis(4-methoxybenzoyl)-diaminopyridine and to determine its complexation with Cu(II) in solution.

Determination of 5-MeO-DIPT in Human Urine Using Gas Chromatography Coupled with High-Resolution Orbitrap Mass Spectrometry

2020 ◽  
Vol 44 (5) ◽  
pp. 461-469 ◽  
Author(s):  
Xiuying Yan ◽  
Ping Xiang ◽  
Yunli Zhao ◽  
Zhiguo Yu ◽  
Hui Yan
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Resolution ◽  
Human Urine ◽  
High Resolution Mass Spectrometry ◽  
Limit Of Detection ◽  
Drug Abusers ◽  
Accuracy And Precision ◽  
Alkaline Conditions ◽  
The Stability

Abstract 5-Methoxy-N,N-Diisopropyltryptamine (5-MeO-DIPT) is a designer hallucinogen derived from tryptamine and its use has been banned by many countries. In this study, a qualitative and quantitative method was developed for determining 5-MeO-DIPT in urine by gas chromatography high-resolution mass spectrometry. 5-hydroxy-N,N-diisopropyltryptamine (5-OH-DIPT) and 5-methoxy-N-isopropyltryptamine (5-MeO-IPT) were identified as 5-MeO-DIPT metabolites in abusers’ urine. 5-MeO-DIPT was extracted from urine by liquid–liquid extraction with ethyl acetate under alkaline conditions. The extract was analyzed by GC-Orbitrap-MS in full scan mode with a resolution of 60,000 full width at half maxima (FWHM). The linear range of this method was 2–300 ng/mL with r > 0.99, and the limit of detection was 1 ng/mL. The accuracy and precision were 93–108.7% and 3.1–10.3%, respectively. This method is simple and sensitive. It has been successfully used to detect 5-MeO-DIPT in drug abusers’ urine, which showed that the concentrations of 5-MeO-DIPT were between 1 and 2.8 ng/mL. 5-OH-DIPT and 5-MeO-IPT, two urinary major metabolites of 5-MeO-DIPT, were identified in urine samples from 5-MeO-DIPT users. Furthermore, the stability of 5-MeO-DIPT in human urine was investigated. It was discovered that the concentration of 5-MeO-DIPT in urine decreased by 22.8, 33.2 and 38.2% after samples were stored for 24 h at 25°C, 5 days at 4°C and 7 days at 4°C, respectively. And 5-MeO-DIPT in urine were stable after they were stored for 30 days at −20°C. Therefore, it is recommended that urine should be stored under freezing conditions before performing 5-MeO-DIPT analysis.

scholarly journals 2,6-Bis((benzoyl-R)amino)pyridine (R = H, 4-Me, and 4-NMe2) Derivatives for the Removal of Cu(II), Ni(II), Co(II), and Zn(II) Ions from Aqueous Solutions in Classic Solvent Extraction and a Membrane Extraction

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 233
Author(s):  
Daria Bożejewicz ◽  
Borys Ośmiałowski ◽  
Małgorzata Anna Kaczorowska ◽  
Katarzyna Witt
Keyword(s):  
Mass Spectrometry ◽  
Solvent Extraction ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
High Resolution Mass Spectrometry ◽  
Membrane Extraction ◽  
Resonance Spectroscopy ◽  
Recovery Processes ◽  
The Stability ◽  
Derivatives Of

In this paper, the application of new substituted 2,6-bis((benzoyl-R)amino)pyridine (R = H, 4-Me, and 4-NMe2) derivatives for the recovery of copper(II), nickel(II), cobalt(II), and zinc(II) ions from aqueous solutions was described. The structures of the synthesized compounds were confirmed by nuclear magnetic resonance spectroscopy (NMR), electrospray ionization high-resolution mass spectrometry (ESI HRMS), and tandem mass spectrometry methods (HCD MS/MS). Three different derivatives of 2,6-bis((benzoyl-R)amino)pyridine were used as carriers in membrane processes and as extractants in classic solvent extraction. In each case, the single derivative recovery was carried out on a model solution that contained only one type of metal ions. Spectrophotometry studies were performed to determine the stability constants of the complexes formed by the synthesized species with analyzed metals ions. The results obtained indicate that the synthesized compounds form stable complexes with Cu(II), Ni(II), Co(II), and Zn(II) ions and can be used in both types of studied recovery processes. However, the effectiveness of the synthesized compounds in the recovery of metal ions depends both on the structure of compounds and properties of metals as well as on their concentration.

scholarly journals LipidQuant 1.0: automated data processing in lipid class separation—mass spectrometry quantitative workflows

2021 ◽  
Author(s):  
Denise Wolrab ◽  
Eva Cífková ◽  
Pavel Čáň ◽  
Miroslav Lísa ◽  
Ondřej Peterka ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Data Processing ◽  
Lipid Class ◽  
High Resolution Mass Spectrometry ◽  
Supplementary Information ◽  
Serum Samples ◽  
Class Separation ◽  
Automated Data Processing ◽  
Lipid Class Separation ◽  
The Individual

Abstract Summary We present the LipidQuant 1.0 tool for automated data processing workflows in lipidomic quantitation based on lipid class separation coupled with high-resolution mass spectrometry. Lipid class separation workflows, such as hydrophilic interaction liquid chromatography or supercritical fluid chromatography, should be preferred in lipidomic quantitation due to the coionization of lipid class internal standards with analytes from the same class. The individual steps in the LipidQuant workflow are explained, including lipid identification, quantitation, isotopic correction, and reporting results. We show the application of LipidQuant data processing to a small cohort of human serum samples. Availability and implementation The LipidQuant 1.0 is freely available at Zenodo https://doi.org/10.5281/zenodo.5151201 and https://holcapek.upce.cz/lipidquant.php. Supplementary information Supplementary data are available at Bioinformatics online.

Lipolytic action of epinephrine in adipose tissue homogenates

1964 ◽  
Vol 206 (1) ◽  
pp. 149-152 ◽  
Author(s):  
David Rubinstein ◽  
Sylvester Chiu ◽  
Jean Naylor ◽  
John C. Beck
Keyword(s):  
Growth Hormone ◽  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Lipolytic Activity ◽  
Supernatant Fraction ◽  
Lipid Layer ◽  
Lipolytic Action ◽  
Tissue Homogenates ◽  
Stimulation Of

Incubation of intact adipose tissue with ACTH, certain preparations of growth hormone, and epinephrine induces an increase in lipolytic activity in homogenates prepared from this tissue. Epinephrine also causes an increase in lipolytic activity when added directly to adipose tissue homogenates. The increase is inhibited by 4 x 10–4 m iodoacetate. Mitochondrial and "supernatant" fractions (including microsomes) and the lipid layer all possess lipase activity, but only the lipase found in the supernatant fraction can be activated by epinephrine. Protamine activates this lipase; addition of epinephrine has no additive effect. Heparin inhibits the stimulation of lipase activity by epinephrine, but has no action on the lipolysis occurring in the absence of epinephrine. It is concluded that the epinephrine-stimulated lipase is distinct from lipoprotein lipase and the lipase present in unstimulated tissue.

scholarly journals Toward Isolation of Palytoxins: Liquid Chromatography Coupled to Low- or High-Resolution Mass Spectrometry for the Study on the Impact of Drying Techniques, Solvents and Materials

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 650
Author(s):  
Antonia Mazzeo ◽  
Michela Varra ◽  
Luciana Tartaglione ◽  
Patrizia Ciminiello ◽  
Zita Zendong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Resolution ◽  
Large Scale ◽  
High Resolution Mass Spectrometry ◽  
Degradation Products ◽  
Pure Water ◽  
Skin Contact ◽  
The Stability ◽  
The Impact

Palytoxin (PLTX) and its congeners are emerging toxins held responsible for a number of human poisonings following the inhalation of toxic aerosols, skin contact, or the ingestion of contaminated seafood. Despite the strong structural analogies, the relative toxic potencies of PLTX congeners are quite different, making it necessary to isolate them individually in sufficient amounts for toxicological and analytical purposes. Previous studies showed poor PLTX recoveries with a dramatic decrease in PLTX yield throughout each purification step. In view of a large-scale preparative work aimed at the preparation of PLTX reference material, we have investigated evaporation as a critical—although unavoidable—step that heavily affects overall recoveries. The experiments were carried out in two laboratories using different liquid chromatography-mass spectrometry (LC-MS) instruments, with either unit or high resolution. Palytoxin behaved differently when concentrated to a minimum volume rather than when evaporated to complete dryness. The recoveries strongly depended on the solubility as well as on the material of the used container. The LC-MS analyses of PLTX dissolved in aqueous organic blends proved to give a peak intensity higher then when dissolved in pure water. After drying, the PLTX adsorption appeared stronger on glass surfaces than on plastic materials. However, both the solvents used to dilute PLTX and that used for re-dissolution had an important role. A quantitative recovery (97%) was achieved when completely drying 80% aqueous EtOH solutions of PLTX under N2-stream in Teflon. The stability of PLTX in acids was also investigated. Although PLTX was quite stable in 0.2% acetic acid solutions, upon exposure to stronger acids (pH < 2.66), degradation products were observed, among which a PLTX methyl-ester was identified.

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>

A Mucin-Specific Protease Enables Molecular and Functional Analysis of Human Cancer-Associated Mucins

2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
High Resolution Mass Spectrometry ◽  
Human Cancer ◽  
Glycosylation Sites ◽  
Bacterial Protease ◽  
Specific Protease ◽  
To Come ◽  
And Function

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>

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