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An approach to analysis of primary amines by a combination of thin‐layer chromatography and matrix‐assisted laser desorption ionization mass spectrometry in conjunction with post‐chromatographic derivatization
摘要： On-spot derivatization has been suggested for the modification of primary amine containing compounds for their analysis by thin-layer chromatography hyphenated with matrix-assisted laser desorption ionization mass spectrometry. The proposed approach was based on post-chromatographic treatment of separated analytes inside the chromatographic zones on the thin-layer chromatography plates by tris(2,6-dimethoxyphenyl)methilium reagent. The derivatives, containing permanent positive charge, reveal exceptionally intense peaks of their cationic moieties and high signal/noise ratio in mass spectra recorded directly from the plates. The method was tested on a series of aliphatic, aromatic, and amine-containing pharmaceuticals.
关键词： thin-layer chromatography,mass spectrometry,primary amines,matrix-assisted laser desorption/ionization,derivatization
更新于2025-09-19 17:13:59
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Fundamentals and Applications of Fourier Transform Mass Spectrometry || Fourier transform ion cyclotron resonance mass spectrometry and laser: A versatile tool
摘要： The coupling of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with laser combines the attributes of laser mass spectrometry with the analytical capabilities of a mass spectrometer having high resolution, high mass measurement accuracy, long ion-observation times, and exceptional ion isolation capabilities required for ion-molecule reaction or ion fragmentation studies [1–3]. The laser may be used for different purposes in mass spectrometry. The most standard one is to generate ions from the surface of the laser-irradiated sample. Two regimes have to be considered in respect with the laser fluence (energy deposit per surface unit in J/cm2) or the laser power density also named irradiance (power density deposit per surface unit in W/cm2). At low laser fluence, laser desorption/ionization (LDI) may take place. When the laser fluence increases, the regime of laser–matter interaction is modified and laser ablation (LA) occurs. In both cases, the ionization phenomenon and the transfer of the atoms or molecules to the gas phase are the direct result of the laser matter interaction. LDI and LA are well suited to the analysis of a wide range of organic, inorganic and also biological compounds. For complex matrices, it is important to note that information may be obtained on both organic and inorganic species. This is of first importance for the study of environmental or composite samples for example, in which organics, inorganics and/or polymers are intimately associated.
关键词： laser,Fourier transform ion cyclotron resonance mass spectrometry,laser desorption/ionization,organic compounds,mass spectrometry imaging,inorganic compounds,laser ablation
更新于2025-09-16 10:30:52
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Detection of extended-spectrum β-lactamases producing Enterobacteriaceae using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry based MBT STAR-BL software module with β-lactamase inhibition assay depends on the bacterial strains
摘要： Rapid and sensitive detection of extended-spectrum β-lactamases (ESBLs) is essential for infection control and antimicrobial treatment. Recently, a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based MBT STAR-BL software module has been used for detecting β-lactamase activity; however, this system cannot differentiate ESBL producing bacteria from other third-generation cephalosporin-resistant strains. In this study, we utilized a MALDI-TOF MS-based MBT STAR-BL method to identify ESBL activity with β-lactamase inhibitors. A cefotaxime (CTX) hydrolysis assay, β-lactamase inhibition, clavulanic acid (CVA), and sulbactam (SBT) were used for detecting ESBL producers with the MBT STAR-BL software module. This software module automatically calculated the logRQ values in each assay. logRQ is the logarithm of the ratio of the summed hydrolyzed peak intensities to the summed non-hydrolyzed peak intensities and measured the efficiency of antibiotic hydrolysis. We divided the logRQ level of the β-lactamase inhibition assay by the logRQ value in the CTX hydrolysis assay, and we used this logRQ ratio as a measure of β-lactamase inhibition efficiency. We assessed the logRQ ratio calculated by this novel method for detecting ESBL producers in 132 Enterobacteriaceae. We performed the MALDI-TOF MS-based MBT STAR-BL approach with β-lactamase inhibitors for detecting ESBL producers and showed that the results of the inhibition assay with β-lactamase inhibitors depended on types of bacterial species. Furthermore, we improved elapsed times and accuracy in MBT STAR-BL methods by using proper β-lactamase inhibitors against specific bacterial strains to compare with the conventional standard lab method. The results suggest that the target bacterial species and β-lactamase inhibitors used were important for the utility of the MALDI-TOF MS-based MBT STAR-BL software module.
关键词： MBT STAR-BL,Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,β-Lactamase inhibition assay,Extended-spectrum β-lactamase
更新于2025-09-16 10:30:52
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Matrix-assisted laser desorption ionization-time of flight mass spectrometry can be used to identify Helicobacter cinaedi
摘要： We examined the applicability of Matrix-assisted laser desorption ionization-time of flight mass spectrometry using 54 Helicobacter cinaedi isolates from humans. In all 54 isolates, MALDI-TOF MS detected H. cinaedi as the best match organism. Our findings suggest that MALDI TOF-MS can be used effectively to identify H. cinaedi.
关键词： Helicobacter cinaedi,Matrix-assisted laser desorption ionization-time of flight mass spectrometry,Identification
更新于2025-09-16 10:30:52
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Exfoliated MXene as a mediator for efficient laser desorption/ionization mass spectrometry analysis of various analytes
摘要： The exfoliated MXene (e-MXene) is systematically investigated as a mediator for laser desorption/ionization time-of-flight mass spectrometry (LDI-MS) analysis. Whereas un-exfoliated MXene has no activity for LDI-MS analysis, the e-MXene presents a high resolution, salt-tolerance and efficiency for LDI-MS analysis of various small molecules regardless of their polarity, aromaticity and molecular weight owing to its physicochemical properties such as high laser energy absorption, electrical conductivity and photothermal conversion. Based on our findings, it is clearly confirmed that e-MXene is a promising material for the development of an efficient platform for LDI-MS analysis of small molecules.
关键词： Metabolite,MXene,Mass spectrometry,Laser desorption ionization,Exfoliation
更新于2025-09-16 10:30:52
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Bacterial identification by lipid profiling using liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry
摘要： Background: In recent years, mass spectrometry (MS) has been applied to clinical microbial biotyping, exploiting the speed of matrix-assisted laser desorption/ionization (MALDI) in recording microbe-specific MS profiles. More recently, liquid atmospheric pressure (AP) MALDI has been shown to produce extremely stable ion flux from homogenous samples and ‘electrospray ionization (ESI)-like’ multiply charged ions for larger biomolecules, whilst maintaining the benefits of traditional MALDI including high tolerance to contaminants, low analyte consumption and rapid analysis. These and other advantages of liquid AP-MALDI MS have been explored in this study to investigate its potential in microbial biotyping. Methods: Genetically diverse bacterial strains were analyzed using liquid AP-MALDI MS, including clinically relevant species such as Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Bacterial cultures were subjected to a simple and fast extraction protocol using ethanol and formic acid. Extracts were spotted with a liquid support matrix (LSM) and analyzed using a Synapt G2-Si mass spectrometer with an in-house built AP-MALDI source. Results: Each species produces a unique lipid profile in the m/z range of 400–1100, allowing species discrimination. Traditional (solid) MALDI MS produced spectra containing a high abundance of matrix-related clusters and an absence of lipid peaks. The MS profiles of the bacterial species tested form distinct clusters using principle component analysis (PCA) with a classification accuracy of 98.63% using a PCA-based prediction model. Conclusions: Liquid AP-MALDI MS profiles can be sufficient to distinguish clinically relevant bacterial pathogens and other bacteria, based on their unique lipid profiles.
关键词： matrix-assisted laser desorption/ionization,mass spectrometry,bacteria,profiling,speciation,MALDI,biotyping,lipids
更新于2025-09-16 10:30:52
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Protein profiling analysis based on matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry and its application in typing Streptomyces isolates
摘要： Marine Streptomyces is a potential source of novel bioactive natural products in medicine and agriculture. The current discrimination and screening method of Streptomyces isolates is not accurate and time-consuming, and a novel method is necessary. In this study, a protein profiling method based on an ultrahigh resolution 15 Tesla Matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) was established and applied for differentiation and bioactivity screening of marine Streptomyces isolates. To obtain robust protein profiling, the effects of the protein extraction method, the matrix-solvent, the sample deposition mode, and the culture time of isolates on protein profiling were thoroughly studied, the optimal conditions were obtained. To evaluate the performance of the developed MALDI-FTICR MS method, MALDI-time of flight (TOF) MS and 16S rRNA were applied in parallel to analyze 25 marine Streptomyces isolates. We found that the clustering result of MALDI-FTICR MS was more similar to that of 16S rRNA than MALDI-TOF MS. And MALDI-FTICR MS could effectively indicate the antibacterial activity of Streptomyces isolates against three plant pathogenic bacteria including Xanthomonas campestris, Xanthomonas oryzae and Erwinia carotovora. Furthermore, a differential protein/peptide was defined and successfully applied to predict antibacterial activity of blind samples. This study demonstrated that MALDI-FTICR MS has great potential to discriminate and screen complex microorganisms, especially those closely related strains.
关键词： Protein profiling,Streptomyces isolates,Cluster analysis,Activity screening,Matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry
更新于2025-09-16 10:30:52
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Distribution of Flavan-3-ol Species in Ripe Strawberry Fruit Revealed by Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging
摘要： Flavan-3-ols, which comprise proanthocyanidins and their monomers, are major ?avonoids in strawberries, and they have a wide range of biological activities and health bene?ts. However, their spatial distribution in strawberry fruit remains poorly understood. Therefore, we performed matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI), to visualize ? ?avan-3-ols in ripe strawberry fruit. Peaks matching the m/z values of ?avan-3-ols [M ? H] ions were detected in the negative ion mode using 1,5-diaminonaphthalene as matrix. Catechin and/or epicatechin, three B-type procyanidins, and two B-type propelargonidins were identi?ed by MALDI-tandem MS. These ?avan-3-ols were mainly distributed in the calyx, in and around the vascular bundles, and in the skin. In-source fragmentation of proanthocyanidins was determined using their standards, suggesting their distribution was mixed ion images of themselves, and fragment ions generated from those had a higher degree of polymerization. B-type procyanidins were predominantly distributed in the vascular bundles than in the skin, whereas B-type propelargonidins were almost equally distributed between the vascular bundles and skin, suggesting that their distribution patterns are di?erent from the type of their ?avan-3-ol monomers. Flavan-3-ols, especially B-type procyanidins, may help prevent pathogen infection not only in the skin but also in and around the vascular bundles.
关键词： mass spectrometry imaging (MSI),propelargonidins,procyanidins,proanthocyanidins,?avan-3-ols,strawberry,matrix-assisted laser desorption/ionization (MALDI)
更新于2025-09-16 10:30:52
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Performances of ionic liquid matrices with butyl ammonium counterion for matrix-assisted laser desorption/ionization mass spectrometric detection and analysis of sucralfate
摘要： In this work, the performances of two ionic liquid matrices (ILMs) with the same ammonium counterpart for mass spectrometric analysis of the insoluble and soluble sucralfate were compared. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was performed assisted by the butylammonium salts of a-cyano-hydroxycinnamic acid (CHCAB) and 2,5-dihydroxybenzoic acid (DHBB). CHCAB has a higher IE than DHBB, but better optical properties. CHCAB is more suitable for the analysis of sucralfate, although molecular ions of both compounds were detectable only with low intensities. Thus, optical properties of ILMs are crucial to enhance the sensitivity of MALDI MS detection of polysulfated oligosaccharides.
关键词： sucralfate,a-cyano-hydroxycinnamic acid,Ionic liquid matrices,2,5-dihydroxybenzoic acid,matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
更新于2025-09-16 10:30:52
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Anti-Myocardial Infarction Effects of Radix Aconiti Lateralis Preparata Extracts and Their Influence on Small Molecules in the Heart Using Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry Imaging
摘要： Radix Aconiti Lateralis Preparata (fuzi) is the processed product of Aconitum carmichaelii Debeaux tuber, and has great potential anti-myocardial infarction e?ects, including improving myocardial damage and energy metabolism in rats. However, the e?ects of Radix Aconiti Lateralis Preparata extracts in a rat model of myocardial infarction have not yet been fully illustrated. Herein, Radix Aconiti Lateral Preparata was used to prepare Radix Aconiti Lateralis Preparata extract (RAE), fuzi polysaccharides (FPS), and fuzi total alkaloid (FTA). Then, we aimed to compare the e?ects of RAE, FPS, and FTA in MI rats and further explore their in?uence on small molecules in the heart. We reported that Radix Aconiti Lateralis Preparata extract (RAE) and fuzi total alkaloid (FTA) signi?cantly improved left ventricular function and structure, and reduced myocardial damage and infarct size in rats with myocardial infarction by the left anterior descending artery ligation. In contrast, fuzi polysaccharides (FPS) was less e?ective than RAE and FTA, indicating that alkaloids might play a major role in the treatment of myocardial infarction. Moreover, via matrix-assisted laser desorption/ionization–mass spectrometry imaging (MALDI–MSI), we further showed that RAE and FTA containing alkaloids as the main common components regulated myocardial energy metabolism-related molecules and phospholipids levels and distribution patterns against myocardial infarction. In particular, it was FTA, not RAE, that could also regulate potassium ions and glutamine to play a cardioprotective role in myocardial infarction, which revealed that an appropriate dose of alkaloids generated more obvious cardiotonic e?ects. These ?ndings together suggested that Radix Aconiti Lateralis Preparata extracts containing an appropriate dose of alkaloids as its main pharmacological active components exerted protective e?ects against myocardial infarction by improving myocardial energy metabolism abnormalities and changing phospholipids levels and distribution patterns to stabilize the cardiomyocyte membrane structure. Thus, RAE and FTA extracted from Radix Aconiti Lateralis Preparata are potential candidates for the treatment of myocardial infarction.
关键词： myocardial infarction,left anterior descending artery ligation,phospholipid,energy metabolism,matrix-assisted laser desorption/ionization–mass spectrometry imaging,Radix Aconiti Lateralis Preparata
更新于2025-09-16 10:30:52