Mass Spectra Research Articles

Surface assisted laser desorption/ionization mass spectrometry of lithium cationized lignans – A tool for rapid screening of plant extracts

Lignans are one of the most widespread classes of plant secondary metabolites possessing unique biological activities. The search for new sources of such compounds, their screening and identification in plant biomass is an urgent task, requiring the use of advanced analytical methods. In the present study, matrix-free surface assisted laser desorption/ionization (SALDI) mass spectrometry was proposed for its solution. The combination of carbon nanocoating sputtered on a target plate with lithium cationization allowed obtaining high-quality mass spectra of eight coniferous wood lignans with different bonds between aromatic units (secoisolariciresinol, matairesinol, 7-hydroxymatairesinol, nortrachelogenin, pinoresinol, guaiacylglycerol-β-guaiacyl ether, dehydrodihydrodiisoeugenol, and divanillin). Three types of fragmentation methods (post-source decay, high- and low-energy collision induced dissociation) for the first time were implemented on two types of MALDI instruments. Regardless of tandem mass spectrometry technique, lignans demonstrated the similar fragmentation patterns including the cleavage of bonds between aromatic units with the formation of mostly lithiated product ions. The low-energy collision induced dissociation in quadrupole ion trap provided the most informative tandem mass spectra and multi-stage fragmentation capabilities in structural studies. On this basis, an approach to rapid, high-throughput, and low-cost screening and tentative identification of lignans including isomeric compounds in plant biomass was developed and successfully tested on real samples of pine, fir, spruce, and larch knotwood extracts.

Synthesis, Characterization, and Optimization of Novel Furan-ring Fused Chalcones via Radical Cyclization of α,β-Unsaturated Ketones and Cyclic Ketone

Abstract: Novel Furan-ring Fused Chalcones (FFC) were synthesized using a radical cyclization reaction of α,β-unsaturated ketones with cyclic ketone as the model reaction to attain this goal. In this study, traditional and microwave-assisted methods for the efficient and cost-effective synthesis of furan-ring fused chalcones in mild reaction conditions are compared and optimized. The goal is to develop a reliable and adaptable synthetic technique that may be used to produce these useful chalcone derivatives quickly and effectively. The optimal experimental conditions for these reactions were carefully determined using two independent methodologies: conventional (Method A) and microwave (Method B). The results indicated that the proposed method B could be used effectively in the future to synthesize novel furans with short reaction times and acceptable yields (87-94 %), and products were purified by column chromatography and preparative thin layer chromatography (PTLC). All new compounds were characterized by 1H-NMR, 13C-NMR, LC-MS, and elemental analyses.

Cytotoxic and antimicrobial metabolites from the marine-derived fungus Aspergillus sp. OPR23-FS01

Chemical investigation of a marine-derived fungus Aspergillus sp. OPR23-FS01 resulted in the isolation of a new unsaturated fatty acid featuring a terminal olefin, 10-methoxy-2-methylene-10-oxodecanoic acid (1), two new natural compounds, 2-carboxy-2′-methyl-azobenzene (2) and 1,3,9-trimethyluric acid (3), and 11 previously described metabolites, pantheric acid C (4), pantheric acid D (5), 2-furoic acid (6), 5-(hydroxymethyl)-2-furancarboxylic acid (7), sporogen-AO 1 (8), gliocladic acid (9), hydroheptelidic acid (10), ditryptophenaline (11), emodin (12), uridine (13), and thymidine (14). Their structures were identified by comprehensive analyses of the spectroscopic methods, including NMR and HRESI mass spectra. Compound 2 possesses a rare diazenyl group among the previously reported fungal metabolites. Compound 8 showed significant cytotoxicity against both HepG2 and MCF-7 cell lines in a dose-dependent manner, with IC50 values of 4.66 ± 0.24 and 5.54 ± 0.28 μM, respectively. Compounds 1−5 and 8−11 displayed antimicrobial effect against Enterococcus faecalis ATCC299212, with MIC values ranging from 32 to 128 μM, whereas 1, 4, 5, and 8−11 inhibited Candida albicans ATCC10231 growth, with MIC values in a range of 32−256 μM.

AntDAS-GCMS: A New Comprehensive Data Analysis Platform for GC-MS-Based Untargeted Metabolomics with the Advantage of Addressing the Time Shift Problem.

Over the years, a number of state-of-the-art data analysis tools have been developed to provide a comprehensive analysis of data collected from gas chromatography-mass spectrometry (GC-MS). Unfortunately, the time shift problem remains unsolved in these tools. Here, we developed a novel comprehensive data analysis strategy for GC-MS-based untargeted metabolomics (AntDAS-GCMS) to perform total ion chromatogram peak detection, peak resolution, time shift correction, component registration, statistical analysis, and compound identification. Time shift correction was specifically optimized in this work. The information on mass spectra and elution profiles of compounds was used to search for inherent landmarks within analyzed samples to resolve the time shift problem across samples efficiently and accurately. The performance of our AntDAS-GCMS was comprehensively investigated by using four complex GC-MS data sets with various types of time shift problems. Meanwhile, AntDAS-GCMS was compared with advanced GC-MS data analysis tools and classic time shift correction methods. Results indicated that AntDAS-GCMS could achieve the best performance compared to the other methods.

MIND4OLIGOS: Determining the Monoisotopic Mass of Oligonucleotides Observed in High-Resolution Mass Spectrometry.

Oligonucleotide therapeutics have emerged as an important class of drugs offering targeted therapeutic strategies that complement traditional modalities, such as monoclonal antibodies and small molecules. Their unique ability to precisely modulate gene expression makes them vital for addressing previously undruggable targets. A critical aspect of developing these therapies is characterizing their molecular composition accurately. This includes determining the monoisotopic mass of oligonucleotides, which is essential for identifying impurities, degradants, and modifications that can affect the drug efficacy and safety. Mass spectrometry (MS) plays a pivotal role in this process, yet the accurate interpretation of complex mass spectra remains challenging, especially for large molecules, where the monoisotopic peak is often undetectable. To address this issue, we have adapted the MIND algorithm, originally developed for top-down proteomics, for use with oligonucleotide data. This adaptation allows for the prediction of monoisotopic mass from the more readily detectable, most-abundant peak mass, enhancing the ability to annotate complex spectra of oligonucleotides. Our comprehensive validation of this modified algorithm on both in silico and real-world oligonucleotide data sets has demonstrated its effectiveness and reliability. To facilitate wider adoption of this advanced analytical technique, we have encapsulated the enhanced MIND algorithm in a user-friendly Shiny application. This online platform simplifies the process of annotating complex oligonucleotide spectra, making advanced mass spectrometry analysis accessible to researchers and drug developers. The application is available at https://valkenborg-lab.shinyapps.io/mind4oligos/.

Spin-2 universal minimal solutions on type IIA and IIB supergravity

In this paper, we consider the spin-2 field perturbations of four families of supergravity solutions. These include AdS5 and AdS7 backgrounds of type IIA as well as AdS4 and AdS6 backgrounds of Type IIB. As the main result, we show that, in all the cases, there is a solution given by a combination of the warp factors. We also find the respective mass spectra. We analyze the normalizability of the solutions and identify the superconformal multiplets dual to them.

TransExION: a transformer based explainable similarity metric for comparing IONS in tandem mass spectrometry

Small molecule identification is a crucial task in analytical chemistry and life sciences. One of the most commonly used technologies to elucidate small molecule structures is mass spectrometry. Spectral library search of product ion spectra (MS/MS) is a popular strategy to identify or find structural analogues. This approach relies on the assumption that spectral similarity and structural similarity are correlated. However, popular spectral similarity measures, usually calculated based on identical fragment matches between the MS/MS spectra, do not always accurately reflect the structural similarity. In this study, we propose TransExION, a Transformer based Explainable similarity metric for IONS. TransExION detects related fragments between MS/MS spectra through their mass difference and uses these to estimate spectral similarity. These related fragments can be nearly identical, but can also share a substructure. TransExION also provides a post-hoc explanation of its estimation, which can be used to support scientists in evaluating the spectral library search results and thus in structure elucidation of unknown molecules. Our model has a Transformer based architecture and it is trained on the data derived from GNPS MS/MS libraries. The experimental results show that it improves existing spectral similarity measures in searching and interpreting structural analogues as well as in molecular networking.Scientific ContributionWe propose a transformer-based spectral similarity metrics that improves the comparison of small molecule tandem mass spectra. We provide a post hoc explanation that can serve as a good starting point for unknown spectra annotation based on database spectra.

MSModDetector: A Tool for Detecting Mass Shifts and Post-Translational Modifications in Individual Ion Mass Spectrometry Data.

Post-translational modifications (PTMs) on proteins regulate protein structures and functions. A single protein molecule can possess multiple modification sites that can accommodate various PTM types, leading to a variety of different patterns, or combinations of PTMs, on that protein. Different PTM patterns can give rise to distinct biological functions. To facilitate the study of multiple PTMs on the same protein molecule, top-down mass spectrometry (MS) has proven to be a useful tool to measure the mass of intact proteins, thereby enabling even PTMs at distant sites to be assigned to the same protein molecule and allowing determination of how many PTMs are attached to a single protein. We developed a Python module called MSModDetector that studies PTM patterns from individual ion mass spectrometry (I2MS) data. I2MS is an intact protein mass spectrometry approach that generates true mass spectra without the need to infer charge states. The algorithm first detects and quantifies mass shifts for a protein of interest and subsequently infers potential PTM patterns using linear programming. The algorithm is evaluated on simulated I2MS data and experimental I2MS data for the tumor suppressor protein p53. We show that MSModDetector is a useful tool for comparing a protein's PTM pattern landscape across different conditions. An improved analysis of PTM patterns will enable a deeper understanding of PTM-regulated cellular processes. The source code is available at https://github.com/marjanfaizi/MSModDetector. Supplementary data are available at Bioinformatics online.

NNLO QCD corrections to the q2 spectrum of inclusive semileptonic B-meson decays

We calculate the next-to-next-to-leading order QCD corrections to the leptonic invariant mass (q2) spectrum of semileptonic b → c inclusive decays, taking into account the mass of the charm quark and the charged lepton in the final state. We obtain analytic results in terms of generalized polylogarithms and present numerical studies of the O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{O} $$\\end{document}(αs2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\alpha}_s^2 $$\\end{document}) corrections to the q2 spectrum of b → cℓν¯ℓ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ c\\ell {\\overline{\ u}}_{\\ell } $$\\end{document} decays, for ℓ = e, μ and τ, in the kinetic scheme. Our computation can be used to incorporate the recent measurements of q2 moments by Belle and Belle II into global fits of inclusive semileptonic B-decays.

Gábor Transform-Based Signal Isolation, Rapid Deconvolution, and Quantitation of Intact Protein Ions with Mass Spectrometry.

High-resolution mass spectrometry (HRMS) is a powerful technique for the characterization and quantitation of complex biological mixtures, with several applications including clinical monitoring and tissue imaging. However, these medical and pharmaceutical applications are pushing the analytical limits of modern HRMS techniques, requiring either further development in instrumentation or data processing methods. Here, we demonstrate new developments in the interactive Fourier-transform analysis for mass spectrometry (iFAMS) software including the first application of Gábor transform (GT) to protein quantitation. Newly added automation tools detect signals from minimal user input and apply thresholds for signal selection, deconvolution, and baseline correction to improve the objectivity and reproducibility of deconvolution. Additional tools were added to improve the deconvolution of highly complex or congested mass spectra and are demonstrated here for the first time. The "Gábor Slicer" enables the user to explore trends in the Gábor spectrogram with instantaneous ion mass estimates accurate to 10 Da. The charge adjuster allows for easy visual confirmation of accurate charge state assignments and quick adjustment if necessary. Deconvolution refinement utilizes a second GT of isotopically resolved data to remove common deconvolution artifacts. To assess the quality of deconvolution from iFAMS, several comparisons are made to deconvolutions using other algorithms such as UniDec and an implementation of MaxEnt in Agilent MassHunter BioConfirm. Lastly, the newly added batch processing and quantitation capabilities of iFAMS are demonstrated and compared to a common extracted ion chromatogram approach.

Electric Field-Modulated Electrospray Ionization Mass Spectrometry for Quantity Calibration and Mass Tracking.

Analyses conducted by electrospray ionization (ESI) mass spectrometry (MS) typically entail performing a number of preparatory steps, which include quantity calibration and mass calibration. Quantity calibration can be affected by signal noise, while mass calibration can be affected by instrumental drift if analyses are performed over an extended period of time. Here, we present two methods for achieving these calibrations using modulation of electrospray plume by alternating electric fields and demodulating the resulting MS ion currents. For this purpose, we use an ESI source fitted with three ring electrodes between the electrospray emitter and the mass spectrometer's inlet. One of these electrodes is supplied with a sine electric signal. Optionally, a nanoESI emitter is also placed between the ring electrodes and the mass spectrometer's orifice to supply calibrant ions. The ion currents, recorded with this setup, present wave-like features. In the first variant, using a triple quadrupole mass analyzer, the ion currents are subjected to data treatment by fast Fourier transform (FFT), and the resulting FFT magnitudes are correlated with analyte concentrations to produce a calibration plot. In the second variant, using a quadrupole time-of-flight mass analyzer, the mass spectra recorded at the analyte ion current maxima are mass-checked using the m/z value of the internal standard (injected via nanoESI emitter), which appears predominantly in the time intervals corresponding to the analyte ion current minima. The setup has been characterized using simulation software and optimized. Overall, the method enables the preparation of quantity calibration plots and monitoring (minor) m/z drifts during prolonged analyses.

#1225 Lactate aggravates mitochondrial dysfunction via ALDH2 lactylation in acute kidney injury

Abstract Background and Aims Elevated lactate levels have been recognized as an independent risk factor in acute kidney injury (AKI) contributed by mitochondrial dysfunction. We previously proved the crucial role of acetaldehyde dehydrogenase 2 (ALDH2) in AKI but not focused on the lactate and lactylation of ALDH2. Method We first established a maleic acid (MA) induced AKI model (MA-AKI) in C57BL/6J mice, administrating 2-DG i.p. (a glycolysis inhibitor) or oxamate (a lactate dehydrogenase A inhibitor) to suppress the lactate production. We measured the renal function, mitochondrial function, and lactate in serum and urine, then evaluated the ALDH2 lactylation by co-immunoprecipitation assays, and identified the specific lactation site by mass spectrum. The role of ALDH2 lactylation was explored through point mutation in HEK293 cells. Furthermore, an ALDH2 lactylation eraser was identified, and its function was elucidated in mice and HK-2 cells. Results The elevated lactate in the kidney, serum, and urine showed a significant positive correlation to the serum creatinine (Scr, R2 = 0.83, P < 0.0001) in MA-induced mice. Both 2-DG and oxamate partly abolished the Scr increasing and the proximal tubular histopathological injuries. Increased pan-lactylation in AKI mice was effectively inhibited by oxamate, parallel with increased ALDH2 lactylation in MA-stimulated HK-2 cells. Mass spectrometry identified a single lactylate lysine residue in ALDH2 (K52). The introduction of a point mutation (K52 to R) in ALDH2, mimicking the delactylated state, led to partial recovery of ALDH2 activity (1.11 ± 0.07 vs. 0.68 ± 0.15, P = 0.0029) and mitochondrial function in MA-stimulated HK-2 cells. Additionally, sirt3 was identified as an ALDH2 lactylation eraser, and Honokiol (a sirt3 activator) demonstrated enhanced renal function and mitigation of mitochondrial dysfunction in both MA-induced mice and HK-2 cells. Conclusion Lactate played a crucial role in mitochondrial dysfunction in AKI partly via induction of ALDH2 lactylation, which shed light on the potential target for the therapy.

GCMS-ID: a webserver for identifying compounds from gas chromatography mass spectrometry experiments.

GCMS-ID (Gas Chromatography Mass Spectrometry compound IDentifier) is a webserver designed to enable the identification of compounds from GC-MS experiments. GC-MS instruments produce both electron impact mass spectra (EI-MS) and retention index (RI) data for as few as one, to as many as hundreds of different compounds. Matching the measured EI-MS, RI or EI-MS+RI data to experimentally collected EI-MS and/or RI reference libraries allows facile compound identification. However, the number of available experimental RI and EI-MS reference spectra, especially for metabolomics or exposomics-related studies, is disappointingly small. Using machine learning to accurately predict the EI-MS spectra and/or RIs for millions of metabolomics and/or exposomics-relevant compounds could (partially) solve this spectral matching problem. This computational approach to compound identification is called in silico metabolomics. GCMS-ID brings this concept of in silico metabolomics closer to reality by intelligently integrating two of our previously published webservers: CFM-EI and RIpred. CFM-EI is an EI-MS spectral prediction webserver, and RIpred is a Kovats RI prediction webserver. We have found that GCMS-ID can accurately identify compounds from experimental RI, EI-MS or RI+EI-MS data through matching to its own large library of>1 million predicted RI/EI-MS values generated for metabolomics/exposomics-relevant compounds. GCMS-ID can also predict the RI or EI-MS spectrum from a user-submitted structure or annotate a user-submitted EI-MS spectrum. GCMS-ID is freely available at https://gcms-id.ca/.

Chemical Analysis of Exhaled Vape Emissions: Unraveling the Complexities of Humectant Fragmentation in a Human Trial Study.

Electronic cigarette smoking (or vaping) is on the rise, presenting questions about the effects of secondhand exposure. The chemical composition of vape emissions was examined in the exhaled breath of eight human volunteers with the high chemical specificity of complementary online and offline techniques. Our study is the first to take multiple exhaled puff measurements from human participants and compare volatile organic compound (VOC) concentrations between two commonly used methods, proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and gas chromatography (GC). Five flavor profile groups were selected for this study, but flavor compounds were not observed as the main contributors to the PTR-ToF-MS signal. Instead, the PTR-ToF-MS mass spectra were overwhelmed by e-liquid thermal decomposition and fragmentation products, which masked other observations regarding flavorings and other potentially toxic species associated with secondhand vape exposure. Compared to the PTR-ToF-MS, GC measurements reported significantly different VOC concentrations, usually below those from PTR-ToF-MS. Consequently, PTR-ToF-MS mass spectra should be interpreted with caution when reporting quantitative results in vaping studies, such as doses of inhaled VOCs. Nevertheless, the online PTR-ToF-MS analysis can provide valuable qualitative information by comparing relative VOCs in back-to-back trials. For example, by comparing the mass spectra of exhaled air with those of direct puffs, we can conclude that harmful VOCs present in the vape emissions are largely absorbed by the participants, including large fractions of nicotine.

A Hybrid Orbitrap‐Nanoelectromechanical Systems Approach to Analysis of Individual, Intact Proteins in Real Time

Nanoelectromechanical systems (NEMS)‐based mass spectrometry (MS) is an emerging technique that enables determination of the mass of individual adsorbed particles, by driving nanomechanical devices at resonance and monitoring the real‐time changes in their resonance frequencies induced by each single molecule adsorption event. We incorporate NEMS into an Orbitrap mass spectrometer and report our progress towards leveraging the single‐molecule capabilities of the NEMS to enhance the dynamic range of conventional MS instrumentation and to offer new capabilities for performing deep proteomic analysis of clinically relevant samples. We use the hybrid instrument to deliver E. coli GroEL molecules (801 kDa) to the NEMS devices in their native, intact state. Custom ion optics are used to focus the beam down to 40 µm diameter with a maximum flux of 25 molecules/second. The mass spectrum obtained with NEMS‐MS shows good agreement with the known mass of GroEL.

P62 promotes FSH-induced antral follicle formation by directing degradation of ubiquitinated WT1

In females, the pathophysiological mechanism of poor ovarian response (POR) is not fully understood. Considering the expression level of p62 was significantly reduced in the granulosa cells (GCs) of POR patients, this study focused on identifying the role of the selective autophagy receptor p62 in conducting the effect of follicle-stimulating hormone (FSH) on antral follicles (AFs) formation in female mice. The results showed that p62 in GCs was FSH responsive and that its level increased to a peak and then decreased time-dependently either in ovaries or in GCs after gonadotropin induction in vivo. GC-specific deletion of p62 resulted in subfertility, a significantly reduced number of AFs and irregular estrous cycles, which were same as pathophysiological symptom of POR. By conducting mass spectrum analysis, we found the ubiquitination of proteins was decreased, and autophagic flux was blocked in GCs. Specifically, the level of nonubiquitinated Wilms tumor 1 homolog (WT1), a transcription factor and negative controller of GC differentiation, increased steadily. Co-IP results showed that p62 deletion increased the level of ubiquitin-specific peptidase 5 (USP5), which blocked the ubiquitination of WT1. Furthermore, a joint analysis of RNA-seq and the spatial transcriptome sequencing data showed the expression of steroid metabolic genes and FSH receptors pivotal for GCs differentiation decreased unanimously. Accordingly, the accumulation of WT1 in GCs deficient of p62 decreased steroid hormone levels and reduced FSH responsiveness, while the availability of p62 in GCs simultaneously ensured the degradation of WT1 through the ubiquitin‒proteasome system and autophagolysosomal system. Therefore, p62 in GCs participates in GC differentiation and AF formation in FSH induction by dynamically controlling the degradation of WT1. The findings of the study contributes to further study the pathology of POR.

A Hybrid Orbitrap-Nanoelectromechanical Systems Approachto Analysis of Individual, Intact Proteins in Real Time.

Nanoelectromechanical systems (NEMS)-based mass spectrometry (MS) is an emerging technique that enables determination of the mass of individual adsorbed particles, by driving nanomechanical devices at resonance and monitoring the real-time changes in their resonance frequencies induced by each single molecule adsorption event. We incorporate NEMS into an Orbitrap mass spectrometer and report our progress towards leveraging the single-molecule capabilities of the NEMS to enhance the dynamic range of conventional MS instrumentation and to offer new capabilities for performing deep proteomic analysis of clinically relevant samples. We use the hybrid instrument to deliverE. coliGroEL molecules (801 kDa) to the NEMS devices in their native, intact state. Custom ion optics are used to focus the beam down to 40 µm diameter with a maximum flux of 25 molecules/second. The mass spectrum obtained with NEMS-MS shows good agreement with the known mass of GroEL.

Time-Resolved Ion Mobility Mass Spectrometry to Solve Conformational Changes in a Cryptochrome.

Many biological mechanisms rely on the precise control of conformational changes in proteins. Understanding such dynamic processes requires methods for determining structures and their temporal evolution. In this study, we introduce a novel approach to time-resolved ion mobility mass spectrometry. We validated the method on a simple photoreceptor model and applied it to a more complex system, the animal-like cryptochrome from Chlamydomonas reinhardtii (CraCRY), to determine the role of specific amino acids affecting the conformational dynamics as reaction to blue light activation. In our setup, using a high-power LED mounted in the source region of an ion mobility mass spectrometer, we allow a time-resolved evaluation of mass and ion mobility spectra. Cryptochromes like CraCRY are a widespread type of blue light photoreceptors and mediate various light-triggered biological functions upon excitation of their inbuilt flavin chromophore. Another hallmark of cryptochromes is their flexible carboxy-terminal extension (CTE), whose structure and function as well as the details of its interaction with the photolyase homology region are not yet fully understood and differ among different cryptochromes types. Here, we addressed the highly conserved C-terminal domain of CraCRY, to study the effects of single mutations on the structural transition of the C-terminal helix α22 and the attached CTE upon lit-state formation. We show that D321, the putative proton acceptor of the terminal proton-coupled electron transfer event from Y373, is essential for triggering the large-scale conformational changes of helix α22 and the CTE in the lit state, while D323 influences the timing.

Design, synthesis, biological evolution and in silico studies of a novel 1,2,3,4‐tetrazole fused with 1,3,4‐thiadiazole‐2‐amine derivatives

AbstractA new series of tetrazole fused with 1,3,4‐thiadiazole‐2‐amine (4a–j) moiety have been synthesized. A thorough characterization of each compound was carried out using mass spectrum data, FT‐IR, 1H, and 13C NMR studies. The antibacterial effectiveness of these prepared substances was assessed in vitro against Gram‐(−) strains of P. aeruginosa and E. coli, as well as Gram‐(+) strains of B. subtilis and S. aureus. Molecules 4f and 4h showed exceptional effectiveness against both types of strains when compared to the reference antibiotic Streptomycin. Moreover the evolution of the molecular docking (in silico) studies also helpful for all the synthesized compounds and reference amoxicillin. The investigation included a look at protein stability, APO‐protein dynamics, and interactions. Using Molecular Dynamics (MD) simulations with Desmond Maestro version 11.3 for this inquiry, a potential lead molecule was found.

A Novel Approach of Electrocatalytic Deamination from Aromatic Amide to Diarylimide on Ni-PTFE Modified Electrode.

A hydrophobic Ni-PTFE modified electrode has been prepared by constant current and cathodic electroplating with a nickel sheet as substrate in a PTFE suspension. Then the Ni-PTFE modified electrode was used for electroreduction from aromatic amide to diarylimide. The electrochemical characterizations such as cyclic voltammogram, EIS, polarization curves, and electrode stability have been carried out by electrochemical workstation. The structure of the electroreduction product diarylimide was characterized by 1HNMR, FT-IR, MS(Mass Spectrum), and EA(Elemental Analyzer). Based on the hydrophobicity of the electrode, an approach suggested that the phenyl ketone radical may be formed by electroreductive deamination at the cathode. With the construction of C-N bond by the radical coupling, the electrocatalytic reduction may be comprised of a one-electron process including an ECC (Electrochemical-Chemical-Chemical) process. The electroreduction of aromatic amide to diarylimide may be controlled by both charge migration and concentration polarization. Electrocatalytic reduction of aromatic amides on Ni-PTFE-modified electrodes is all well conversion ratio.