High-performance Liquid Chromatography-mass Spectrometry Research Articles

Degradation of norfloxacin by the synergistic effect of micro-nano bubbles and sodium hypochlorite: kinetics, influencing factors and pathways.

This study thoroughly investigated the degradation of norfloxacin (NOR) under the influence of micro-nanobubbles (MNBs) and sodium hypochlorite (NaClO), focusing on their synergistic effects. The impact of various environmental factors, including NaClO concentration, pH, inorganic anions, and surfactants, on NOR degradation efficiency within the MNBs/NaClO system was systematically assessed. The basic properties of the MNBs/NaClO system and the degradation kinetics of NOR were explored. The degradation products and pathways of NOR were explored to reveal the degradation mechanism of antibiotics in the MNBs/NaClO system by employing density functional theory (DFT) and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The redox potential of the MNBs/NaClO system exhibited significantly superior properties than the single system, with bubble sizes predominantly in the nanoscale. The degradation kinetics of NOR adhered to a pseudo-first-order reaction model, with optimal degradation occurring at a 0.025% NaClO volume concentration. Acidic conditions promoted the degradation of NOR, and alkaline conditions inhibited the degradation of NOR. Inorganic anions PO43-, HCO3-, and CO32- in the water matrix led to strong inhibition of NOR degradation. Cationic surfactants accelerated the degradation process of NOR, while anionic and nonionic surfactants had a consistent inhibitory effect on the degradation of NOR. Based on the degradation behavior, three potential pathways for NOR degradation were proposed: quinolone group transformation, defluorination reaction, piperazine ring cracking and quinolone ring decomposition. This research contributes a novel technical approach for addressing antibiotic pollution and offers a theoretical framework for understanding the fate of antibiotics in the environment.

Development of microflow ultra high performance liquid chromatography-mass spectrometry metabolomic assays for analysis of mammalian biofluids

Introduction and objectivesThe application of untargeted metabolomics assays using ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) to study metabolism in biological systems including humans is rapidly increasing. In some of these studies there is a requirement to collect and analyse low sample volumes of biofluids (e.g. tear fluid) or low cell and tissue mass samples (e.g. tissue needle biopsies). The application of microflow, capillary or nano liquid chromatography (≤ 1.0 mm column internal diameter (i.d.)) theoretically should accomplish a higher assay sensitivity compared to analytical liquid chromatography (2.1–5.0 mm column internal diameter). To date, there has been limited research into microflow UHPLC-MS assays that can be applied to study samples of low volume or mass.MethodsThis paper presents three complementary UHPLC-MS assays (aqueous C18 reversed-phase, lipidomics C18 reversed-phase and Hydrophilic Interaction Liquid Chromatography (HILIC)) applying 1.0 mm internal diameter columns for untargeted metabolomics. Human plasma and urine samples were applied for the method development, with porcine plasma, urine and tear fluid used for method assessment. Data were collected and compared for columns of the same length, stationary phase and stationary phase particle size but with two different column internal diameters (2.1 mm and 1.0 mm).Results and conclusionsAll three assays showed an increase in peak areas and peak widths when applying the 1.0 mm i.d. assays. HILIC assays provide an advantage at lower sample dilutions whereas for reversed phase (RP) assays there was no benefit added. This can be seen in the validation study where a much higher number of compounds were detected in the HILIC assay. RP assays were still appropriate for small volume samples with hundreds of compounds being detected. In summary, the 1.0 mm i.d. column assays are applicable for small volume samples where dilution is required during sample preparation.

Identification of metabolic biomarkers in idiopathic pulmonary arterial hypertension using targeted metabolomics and bioinformatics analysis

Pulmonary arterial hypertension (PAH) is a life-threatening disease with a poor prognosis, and metabolic abnormalities play a critical role in its development. This study used metabolomics, machine learning algorithms and bioinformatics to screen for potential metabolic biomarkers associated with the diagnosis of PAH. In this study, plasma samples were collected from 17 patients diagnosed with idiopathic pulmonary arterial hypertension (IPAH) and 20 healthy controls. Plasma metabolomic profiling was performed by high-performance liquid chromatography-mass spectrometry. Gene profiles of PAH patients were obtained from the GEO database. Key differentially expressed metabolites (DEMs) and metabolism-related genes were subsequently identified using machine learning algorithms. Twenty differential plasma metabolites associated with IPAH were identified (VIP score > 1 and p < 0 0.05), and enrichment analysis revealed the arginine biosynthesis pathway as the most altered pathway. Using machine learning models, including least absolute shrinkage and selection operator (LASSO), random forest (RF) and support vector machine (SVM), we extracted key metabolites that correlated with clinical phenotypes. Our results suggested that five metabolites, kynurenine, homoserine, tryptophan, AMP, and spermine, are potential biomarkers for IPAH. Bioinformatics analysis also identified 3 metabolism-related genes, MAPK6, SLC7A11 and CDC42BPA, that are strongly correlated with pulmonary hypertension, demonstrating strong predictive power and clinical relevance. Our findings revealed some key genes associated with metabolism in PH, and provided crucial information about complex metabolic reprogramming signals and may lead to the identification of useful metabolic biomarkers for the diagnosis of PAH.

Toxigenic Cyanobacteria and Microcystins in a Large Northern Oligotrophic Lake Onego, Russia

Toxigenic cyanobacteria and microcystins in the oligotrophic pelagic zone and mesotrophic bay of Lake Onego—the second largest lake in Europe—were found for the first time. Microscopic analysis revealed that Dolichospermum lemmermannii, D. circinale and D. spiroides dominated in bloom spots in the oligotrophic zone of the lake and D. flos-aquae and Microcystis aeruginosa OKin the eutrophic bay. The abundance of cyanobacteria in bloom spots is potentially hazardous for humans and animals. PCR-analysis showed that mcyA gene involved in microcystin biosynthesis was found in cyanobacteria of the genera Dolichospermum and Microcystis. Five structural variants of intracellular microcystins were detected in a trace amount using high-performance liquid chromatography–mass-spectrometry of high resolution. The most hazardous hepatotoxin, MC-LR, was found only in the eutrophic bay. In the present study, the reasons for the low cyanotoxin content in the phytoplankton dominated by Dolichospermum are discussed. The findings of our study make a significant contribution to the accumulation of facts which state that toxigenic cyanobacterial blooms can occur in large oligotrophic lakes.

Activation of persulfate by MOF-derived MnFeOx to efficiently degrade sulfadiazine: Synergistic effects from free radicals and singlet oxygen

In this study, a facile hydrothermal approach was used to synthesize the MOFs materials [Mn-doped MIL-101(Fe)]. These materials were subsequently subjected to high temperature annealing process via calcination to generate the MOFs derivatives (MnFeOx). The synthesized materials were utilized for the removal of sulfadiazine (SDZ) removal through activated peroxymonosulfate (PMS). At the optimum Mn doping, the removal ratio of SDZ could reach 98.9 % (at natural pH) within 20 min. In addition, the study investigated the influence of PMS dosage, catalyst dosage, initial pH, various inorganic anions, and humic acid (HA) on the degradation of SDZ. The activation processes of both free and non-free radicals in the MnFeOx/PMS system were examined by free radical quenching experiments and electron paramagnetic resonance (EPR) techniques. The analysis of the degradation products of SDZ was conducted by using high performance liquid chromatography-mass spectrometry (HPLC-MS), and the breakdown pathways of SDZ in the MnFeOx/PMS system were proposed.

Investigating the metabolism of four sulfonamides in grass carp via HPLC-MS for screening candidate materials of matrix reference material

An efficient, sensitive, and precise method for investigating the metabolism of four sulfonamides in grass carp has been established using high-performance liquid chromatography-mass spectrometry. By optimizing the experimental conditions, the method achieved a coefficient of determination above 0.999, with detection and quantification limits set at 0.5 μg/kg and 1.0 μg/kg, respectively. Recovery rates were between 92.90 % and 102.84 %, and relative standard deviations ranged from 1.70 % to 9.83 %, enabling the precise detection of these sulfonamides in grass carp tissue. The factors affecting the metabolic rate during the medicated bath process were investigated, and obtained the optimal parameter conditions for screening the candidate materials. The candidate materials screened through this method exhibit good stability when used to prepare matrix standard substances, this work not only provides a scientific basis for screening sulfonamide candidate materials but also offers insights for developing other matrix reference materials.

Stratified nanoflower bimetallic cobalt/iron alloy derived from CoFe-MOFs as efficient peroxymonosulfate activator for antibiotics degradation: Performance, mechanism, and toxicity

Co-based metal-organic framework (Co-MOFs) derivative has gained wide attention in the field of advanced oxidative processes (AOPs). However, the degradation efficiency of single cobalt element remains suboptimal and its activation mechanism still needs to be further explored. In this study, stratified nanoflower bimetallic cobalt/iron alloys (CoFe-NC), derived from cobalt/iron bimetallic-organic frameworks (CoFe-MOFs), was synthesized via self-assembly at room temperature, hydrothermal synthesis and high-temperature carbonization processes and their performance as efficient activators of peroxymonosulfate (PMS) for the degradation of antibiotics was evaluated (removal efficiency of 100 % within 40 min, k=0.0951 min−1). The excellent degradation property benefit by specific nano-flowers structure with high specific surface area (424.67 m2/g), the cycle between Co0→Co2+↔ Co3+ and Fe0→Fe2+↔Fe3+, synergistic effect of Co and Fe bimetals. Furthermore, the CoFe-NC/PMS system exhibits exceptionally high cyclic stability (over 85 % degradation efficiency after four times degradation), a wide range of pH (3−11) and resistance to background ion interference (Cl–, H2PO4–, NO3–, HCO3– and HA), and reduced toxicity of the degradation products. Degradation mechanistic studies demonstrated that the activation of PMS by CoFe-NC generated amounts of reactive oxygen species (ROS) (SO4•−, •OH, •O2− and 1O2). Additionally, high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis identified fifteen intermediate degradation products and three possible degradation pathways were proposed. The results highlight the potential of CoFe-NC as a catalyst for antibiotic removal, providing insights into the optimization of bimetallic-organic framework for environmental applications.

Molecular properties of dissolved organic matter leached from microplastics during photoaging process

The occurrence of dissolved organic matter (DOM) derived from microplastics (MPs) and its effect on aquatic systems has attracted great interest recently. However, the photoaging effect on the molecular structure of MP-derived DOM (MP-DOM) remains unclear. This paper presents the characteristics of DOM leached from three commercial MPs, i.e., polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) under UV irradiation. With prolonged aging periods, the surface roughness and oxygen-containing groups on the surface of MPs increase as more DOM leachate is generated. Moreover, the dissolved organic carbon (DOC) content of the leached DOM from PET MPs varies from 0.52 mg/L to 2.25 mg/L, which is higher than PE and PP MPs, due to the larger increased surface reaction area and the cleavage of the benzene ring. According to the excitation-emission matrix and parallel factor analysis (EEM-PARAFAC), the plastic-derived protein/phenolic-like components (C1 and C3) in MP-DOM were changed into photo-induced humic-like components (C2), which were closely related to the intermediates during photo-oxidation. High-performance liquid chromatography-mass spectrometry (HPLC−MS) analysis further identified that the highest proportion of antioxidants (24.8 %∼34.6 %) was contained in MP-DOM. Plasticizers, intermediate additives, and antimicrobial agents were also detected in DOM leachate. Correlation analysis identified that the composition of leached DOM was positively correlated with the surface roughness, the carbonyl index (CI), and the chemical groups of MPs. Moreover, a partial least square structural equation model (PLS−SEM) analysis further verified that the change of morphology and the chemical structure of MPs could affect the DOM structures and fractions directly. This study provides an in-depth understanding of the composition of MP-derived DOM during the aging process, as well as a comprehensive environmental impact assessment of MPs.

Calixarene incorporated molecular imprinting on covalent organic framework for supramolecular recognition and specific extraction of citrinin

Specific recognition and selective extraction of mycotoxin in environmental and food matrixes is significant to guarantee public health. Covalent organic frameworks (COFs) are promising adsorbents with tailorable functionality, but their low binding affinity and poor selectivity hamper their wide application for selective extraction of trace mycotoxin from complex matrix. Herein, we report calixarene incorporated molecular imprinting on COF to prepare molecularly imprinted calix[4]arene-containing COF (MICOF-CX4) for supramolecular recognition and specific adsorption of citrinin. Calixarene with host-guest chemistry was used as a functional monomer, while amine units with different topologies and function groups were selected to regulate MICOF-CX4 to match with citrinin. The complementary shape and supramolecular interactions of MICOF-CX4 gave highly selective recognition for citrinin. Moreover, MICOF-CX4 with vast accessible surface and plentiful imprinting sites exhibited faster adsorption kinetics and 4-fold higher adsorption capacity for citrinin adsorption than no-imprinted COF-CX4. Combination of MICOF-CX4 based solid-phase extraction with high-performance liquid chromatography-mass spectrometry allowed interference free determination of trace citrinin in real samples with a low detection limit of 0.03 ng mL−1, good precision of 4.5 % and quantitative recovery of 88.2 %−101.4 %. The cooperative functions of calixarene and molecular imprinting make COF promising adsorbent for specific adsorption of trace targets in complex matrixes.

Quantitation of the DNA-dependent protein kinase inhibitor peposertib (M3814) and metabolite in human plasma by LC-MS/MS.

The DNA-dependent protein kinase (DNA-PK) is an abundant nuclear protein that mediates DNA double-strand break repair by nonhomologous end joining (NHEJ). As such, DNA-PK is critical for V(D)J recombination in lymphocytes and for survival in cells exposed to ionizing radiation and clastogens. Peposertib (M3814) is a small molecule DNA-PK inhibitor currently in preclinical and clinical development for cancer treatment. We have developed a high-performance liquid chromatography-mass spectrometry method for quantitating peposertib and its metabolite in 0.1 mL human plasma. After MTBE liquid-liquid extraction, chromatographic separation was achieved with a Phenomenex Synergi polar reverse phase (4μm, 2× 50 mm) column and a gradient of 0.1% formic acid in acetonitrile and water over an 8min run time. Mass spectrometric detection was performed on an ABI SCIEX 4000 with electrospray, positive-mode ionization. The assay was linear from 10 to 3000 ng/mL for peposertib and 1-300 ng/mL for the metabolite and proved to be both accurate (97.3%-103.7%) and precise (<8.9%CV) fulfilling criteria from the Food and Drug Administration (FDA) guidance on bioanalytical method validation. This liquid chromatography-tandem mass spectroscopy (LC-MS/MS) assay will support several ongoing clinical studies by defining peposertib pharmacokinetics.

Sociodemographic and dietary determinants of glyphosate exposure in a NYC-based pregnancy cohort

Previous studies have provided evidence for associations between glyphosate and aminomethylphosphonic acid (AMPA) exposure and adverse birth outcomes. However, few pregnancy cohort studies have investigated dietary and other determinants of glyphosate and AMPA exposure. We aimed to identify dietary and sociodemographic factors that predict glyphosate and AMPA exposure in a contemporary, urban pregnancy cohort in the US. The study included 725 pregnant participants from the New York University Children's Health and Environment Study (NYU CHES) in New York City. Urinary concentrations of glyphosate and AMPA, determined by high-performance liquid chromatography and tandem mass spectrometry, were analyzed in urine collected from NYU CHES participants across three prenatal time points. The Diet Health Questionnaire II was completed to capture dietary intake during the prenatal period. Descriptive statistics and bivariate linear models were used to assess determinants of urinary glyphosate and AMPA concentrations. Median urinary glyphosate and AMPA levels were 0.36 ng/mL and 0.37 ng/mL, respectively. Lower glyphosate levels were associated with younger age, obesity, public insurance, being single, and lower educational attainment. Nuts, seeds and whole grain intake was associated with increased urinary glyphosate concentrations. Urinary glyphosate concentrations were lower in summer than in winter. The study findings highlight widespread exposure to glyphosate and AMPA in this pregnancy cohort, with nuts/seeds and whole grains identified as possible dietary sources of exposure. High detection rates in the study population necessitate further research on dietary exposure patterns and perinatal outcomes to inform targeted interventions and reduce exposure in vulnerable populations.

Acne-related UVA-induced facial fluorescence: An exploratory study from physiological properties to tissue structure information

UVA-induced facial fluorescence (UVAF) is recognized as an objective measurement technique to quantify the severity of acne. However, notable inconsistencies in quantitative outcomes have been observed in various studies, possibly due to the fact that different colors of fluorescence represent different pathophysiological implications. This study investigated the pathophysiological importance of UVAF color differences and improved its reliability in assessing acne severity. MIDOO Smart Skin Imager was used to capture UVAF and analyze the correlation between fluorescence colors and acne lesions. Techniques such as two-photon excited fluorescence microscopy, scanning electron microscopy, western blot, and high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) were used to examine the biochemical composition and structure of comedonal plugs and follicular casts associated with different fluorescence colors. We found that green fluorescence correlates with non-inflammatory acne lesions (comedones), while orange-red fluorescence shows no correlation with either type of lesion. Green fluorescence is associated with higher levels of keratin, indicating keratinization, while orange-red fluorescence is associated with porphyrin from S. epidermidis. UVAF color differences - orange-red are from porphyrins and green from keratin. This distinction helps to understand the structural and physiological bases of facial fluorescence, with potential implications for clinical evaluations of acne.

Биологически активные гидролизаты белков молока и их комплексы включения с циклодектринами

Enzymatic hydrolysis of dairy proteins increases their nutritional and biological value while reducing their allergenic potential. The subsequent complexation of peptides with cyclodextrins (CDs) reduces the bitterness of the hydrolyzed proteins. The research objective was to obtain hydrolysates of whey proteins and their cyclodextrin inclusion complexes with peptides, as well as to describe the peptide composition of the cleaved dairy proteins, biological activity, and sensory profile of the hydrolysates and inclusion complexes. The research featured enzymatic whey protein hydrolysates with an extensive hydrolysis degree and their inclusion complexes with β- and γ-CDs. Dairy proteins were hydrolyzed with alcalase, and the hydrolysates obtained were subjected to micro- and ultrafiltration (cut-off limit – 10 kDa). The peptide composition of the hydrolyzed proteins was determined by the methods of high-performance liquid chromatography and chromatography-mass spectrometry. The antimutagenic activity was evaluated using the Ames test whereas the antibacterial effect was studied with the impedimetric method. The antioxidant activity was detected with fluorimetry and spectrophotometry. The method of competitive enzyme immunoassay was applied to reveal the antigenic properties. The bitterness of the experimental sample s was determined by a sensory evaluation. The research delivered the optimal modes for whey protein cleavage with alcalase that made it possible to achieve efficient micro- and ultrafiltration. The resulting hypoallergenic peptide fractions and their inclusion complexes with β- and γ-CDs possessed antioxidant, antibacterial, and antimutagenic properties. The whey proteolysis and subsequent filtration with/without tindalization demonstrated a 265/589-fold decrease in the residual antigenicity. The fluorimetric method showed a 1.79/1.90-fold increase in the antioxidant activity of the hydrolysate in complexes with β- and γ-CDs. Binding of β-CDs to peptides enhanced their antimicrobial activity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538. The hydrolysate samples with β-CDs showed less bitterness. Whey proteolysis with alcalase under optimized conditions and subsequent fractionation resulted in a product with high consumer qualities. Enzymatic hydrolysates of dairy proteins and their CD inclusion complexes were able to substitute native protein components. Their bioactive properties, good taste, and low allergenic potential mean good prospects for the functional food industry.

Downstream Effects of the Pandemic? Spatiotemporal Trends of Quaternary Ammonium Compounds in Suspended Particulate Matter of German Rivers

During the SARS-CoV-2 pandemic, the preventive use of antimicrobials such as quaternary ammonium compounds (QACs) surged worldwide. As cationic and surface-active biocides, QACs are only partly removed during wastewater treatment and may cause adverse ecological effects in the downstream environment. To understand the environmental consequences of increased disinfectant use during the pandemic, we investigated spatiotemporal QAC concentration trends in the suspended particulate matter (SPM) of three diverse German rivers. Covering pooled annual SPM samples from 2006-2021 and monthly samples from 2018-2021 collected by the German Environmental Specimen Bank, 31 QACs were quantified by high performance liquid chromatography–mass spectrometry.∑QAC concentrations in annual samples differed by more than tenfold between rivers in the order Saar (average 6.7µg/g) > Rhine (0.9µg/g) > Mulde (0.3µg/g). The strongest potential pandemic imprint was however observed in the Mulde (+67%) and Rhine (+22%). Besides pandemic dynamics, also seasonal variation and mineral content of SPM tentatively affected QAC concentrations. Exceedance of predicted no-effect concentrations for sediment suggest ecotoxicological risks for long-chained QACs already before the pandemic. Our study thus highlights the importance of monitoring the environmental effects of antimicrobial use during pandemics and calls for an urgent minimization of non-essential applications. Environmental implicationThe SARS-CoV-2 pandemic caused a global surge in disinfectant use, including quaternary ammonium compounds (QACs). This raises concerns about their environmental residues, aquatic toxicity and contribution to the (co)selection of antimicrobial resistance in pathogens. To assess these ecotoxicological risks, we investigated spatiotemporal QAC concentration trends in suspended particulate matter of German rivers. While seasonal and spatial fluctuations exceed a potential pandemic “imprint” by a factor of 10, concentrations of some QACs reach ecotoxicological effect levels. This highlights the need to consider particle-associated QAC concentrations, the widespread use of QAC, as well as the environmental implications of chemical public health interventions.

Investigation of the Role of Chemical Analysis in Causality Assessment of Herbal and Dietary Supplement-Induced Liver Injury.

The attribution of drug-induced liver injury (DILI) to specific herbal and dietary supplements (HDS) is confounded by inaccurate labels and undisclosed ingredients. The US Drug-Induced Liver Injury Network (DILIN) determines the attribution of injury to an agent through its structured expert opinion causality assessment process, but without the use of chemical analysis data of HDS. We aimed to determine the impact of chemical analysis of HDS products on prior causality assessment scores. Obtained samples of HDS consumed by DILIN-enrolled patients were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Chemical analysis data were compared to label accuracy and detect whether the product contained botanical and non-botanical compounds. A comparison of the causality scores reassessed with chemical analysis was compared with the original scores. A total of 54 previously adjudicated cases with chemical analysis available were reassessed for causality with chemical analysis data; reviewers were blinded to original causality scores. Using the chemical analysis data, 37% (n = 20) of the 54 cases were scored with a higher likelihood of DILI compared with the original causality scores; 14 of the 20 (70%) moved from probable to highly likely; 52% had no change in causality score; and 11% of cases were scored as a lower likelihood of DILI. Our study demonstrates that there is value in using HDS chemical analysis data in the causality assessment process for DILI. In more than a third of cases, chemical analysis of products led to an increased confidence in DILI attribution to HDS. These findings suggest that chemical analysis is an important tool in causality assessment for HDS agents, specifically in challenging situations, and further studies are needed to confirm its applicability in clinical practice.

Exploring of Chemical Profile and Biological Activities of Three Ocimum Species From Comoros Islands: A Combination of In Vitro and In Silico Insights.

Ocimum species have a great interest in different traditional medicinal systems. This study examined the chemical composition, antioxidant properties, enzyme inhibitory effects, and antibacterial and antifungal activities of the aerial parts of Ocimum gratissimum, Ocimum americanum, and Ocimum basilicum from the Comoros Islands. The extracts were analyzed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) to determine their chemical composition. Antioxidant activity was assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), chelating ability, and phosphomolybdenum radical scavenging assays. Enzyme inhibitory activities against acetylcholinesterase (AChE), butrylcholinesterase (BChE), tyrosinase, amylase, and glucosidase were evaluated using spectrophotometric methods. Antibacterial and antifungal activities were tested using the broth microdilution method against selected pathogenic microorganisms. The selected enzymes and proteins were evaluated using in silico methods with biomolecules from these plants. In addition, 111 different metabolites were identified in the tested extracts using advanced HPLC/MS techniques. The most significant number of detected compounds were derivatives of hydroxycinnamic acids, followed by flavonoid glycosides and aglycones and derivatives of hydroxybenzoic acids. All three Ocimum species exhibited significant antioxidant activities, O. gratissimum exhibited the best-reducing abilities in CUPRAC and FRAP assays. In addition, enzyme inhibitory assays revealed that O. americanum had the most potent inhibitory effect on tyrosinase (48.01 ± 3.89 mg kojic acid equivalent [KAE]/g), and amylase (1.08 ± 0.02 mmol acarbose equivalent [ACAE]/g). Antibacterial and antifungal tests demonstrated that the extracts possess broad-spectrum activity. Molecular docking results showed that compounds exhibited remarkable binding energies with target enzymes and proteins. The molecular dynamics simulations identified chicoric acid with MurE of Staphylococcus aureus complex as the most promising drug candidate. These findings support their traditional medical and nutraceutical uses and suggest possibilities for natural functional applications.

Insoluble Proteomics Analysis of Acute Intracranial Large Vessel Occlusive Thrombus.

Acute large vessel occlusion (LVO) stroke is highly prevalent and severe. Despite thrombolytic therapy, many patients experience substantial complications. Understanding the origins, constituents, and pathological processes involved in thrombus formation in acute intracranial large artery occlusion is crucial. To identify the characteristics of insoluble proteins from different sources of cerebral thrombus. This study included 13 patients with cardiogenic embolic thrombus (CE) and 15 with large artery atherosclerosis thrombus (LAA). High-performance liquid chromatography and liquid chromatography-tandem mass spectrometry were used to analyze insoluble proteins in thrombi. Bioinformatics analyses explored differential proteins and associated functional pathways. Least Absolute Shrinkage and Selection Operator and Random Forest identified biomarkers for diagnosing thrombus sources, validated by parallel reaction monitoring. We constructed an insoluble protein atlas of cerebral thrombi, identifying 6975 insoluble proteins, including 143 extracellular matrix (ECM)-related proteins. The enrichment pathways considerably varied between thrombi from different sources. Inflammation-related pathways, such as "acute inflammatory response," along with ECM-related pathways such as "laminin interactions," were notably upregulated in LAA compared to CE. Additionally, two biomarkers (IDH2, HSPG2) exhibited strong diagnostic performance (AUC = 1) and robustness. In the insoluble Proteomics of thrombus, we highlighted the crucial roles of immune responses and ECM proteins in thrombus formation, providing new insights into its mechanisms and potential drug development. Additionally, we identified two biomarkers that offer new methods for determining thrombus sources in patients with LVO.

Identification of bioactive compounds in Amphipterygium adstringens branch bark

Background: Cuachalalate (Amphipterygium adstringens) is one of Mexico’s most commercialised medicinal plants, and its natural populations are mainly found in this country. The high demand for stem bark (SB) has risked its survival, making it necessary to develop sustainable strategies.Aim: This study aimed to identify bioactive compounds in branch bark (BB) and evaluate their antipathogenic and antivirulence capacities.Setting: The study was conducted in the low deciduous forest (LDF) of the State of Puebla, Mexico.Methods: Bioactive metabolites in BB were profiled by high-performance thin-layer chromatography (HPTLC). The chemical composition of aqueous bark extracts was scrutinised by high-performance liquid chromatography-mass spectrometry (HPLC-EM-SQ-TOF system) and molecular network analysis. The folk method’s antipathogenic capacity was determined in a burn model in mice infected with Pseudomonas aeruginosa. Finally, the antivirulence properties of bark organic extracts were determined.Results: The BB contained masticadienoic, 3α-hydroxymasticadienoic and anacardic acids, also present in SB. The aqueous extracts showed the presence of flavonoids, catechins and saponins in both barks. The folk method using BB extracts significantly reduced mouse mortality and prevented sepsis development. This might be related to the capability of extracts to block the production of bacteria virulence factors.Conclusion: The similarity in bioactive metabolites and biological activity between SB and BB of cuachalalate suggests that using BB as a medicinal agent could be a practical and sustainable strategy. This approach could potentially prevent the overexploitation of cuachalalate’s SB, contributing to its conservation.Contribution: This study proposes a sustainable strategy for using cuachalalate as a medicinal agent using BB, a renewable source.

Threonine In Different Phenotypes Of Chronic Heart Failure With Preserved Ejection Fraction

Background — Chronic heart failure with preserved ejection fraction (CHFpEF) develops as a result of many diseases that lead to significant metabolic disorders. Given the heterogeneity of this group of patients, therapeutic options for this syndrome are extremely limited. In this regard, it seems promising to study the metabolomic profile in patients with CHFpEF to identify biomarkers, examine their roles in the pathogenesis of the syndrome, and search for potential targets for targeted therapy. Objective — The study aimed at testing the correlation between the threonine level and the features of the clinical course of CHFpEF. Methods — The study included a total of 154 patients: 82 with CHFpEF, 45 with hypertension and/or coronary artery disease (comparison group), and 27 healthy volunteers (control group). Threonine levels were assessed using high-performance liquid chromatography-mass spectrometry. Results — The threonine concentration was significantly reduced in patients with CHFpEF (1) vs. comparison group (2) and control group (3): p&lt;0.001; p1-3&lt;0.001; p2-3=0.037). A reduction in the threonine level was characteristic for patients with diabetes mellitus vs. patients without it (p=0.029). Conclusion — Given the importance of threonine in energy metabolism and significant changes in its level in various pathophysiological processes, it should be considered as an additional diagnostic and prognostic criterion for CHFpEF. Additional studies are needed to better understand the role of threonine in the pathophysiology of cardiovascular diseases.

Storing liquid chromatographic separations on surface energy traps: decoupling the LC and the mass spectrometer.

We report a micro-fractionation device for high performance liquid chromatography-mass spectrometry to archive chromatographic separations on an array of optimized surface energy traps (SETs). The method has the potential to significantly alter nanoflow LC-MS workflow, decoupling separation and analysis. The wetting characteristics of the SETs cause the HPLC eluent stream to spontaneously split into droplet microfractions. The droplet mirofractions are then dried down to enable facile storage and transport of the archived separation. Discontinuously dewetting array parameters were explored to maximize array volume and resolution using a combination of SET design, shape, size, and spacing. Mass spectrometry analysis is performed utilizing a liquid micro-junction surface sampling probe to extract dried analytes from the surface of the SETs followed by electrospray ionisation. A reverse phase separation of pharmaceutical compounds is "recorded" using the micro-fractionation device followed by "reading" the chromatographic trace with a mass spectrometer 24 hours after the separation was performed/archived, demonstrating a true decoupling of LC, and MS. Additionally, we demonstrate the ability to collect microfractions with sub-one-second integration time, approaching the scan time of a mass spectrometer or UV-Vis detector. With further improvements to the device, sub-1-second micro-fractionation may enable seamless reconstruction of archived chromatograms indistinguishable from online LC-MS data, while also providing the benefits of easy storage and transport of archived separations.