Search Results (2,213)

Peptide mapping is a well-established method for confirming the identity of therapeutic proteins as part of batch release testing and product characterization for regulatory filings. Traditionally based on enzymatic digestion followed by reversed-phase liquid chromatography and UV detection, the method has evolved with technological advancements to incorporate mass spectrometry (MS), enabling more detailed structural insights. Residue-level confirmation of amino acid sequences requires MS/MS fragmentation, which produces large amounts of data that must be processed using specialized software. In regulated environments, the use of academic algorithms is often limited by validation requirements, making it necessary to rely on commercially approved tools, although their built-in scoring systems have limitations that can affect sequence assignment accuracy. Here, we present representative examples of incorrect peptide assignments generated by commercial software. In antibody sequence analysis, misidentifications resulted from isobaric and near-isobaric dipeptides (e.g., SA vs. GT). Additional examples from the analysis of SARS-CoV-2 spike protein variants revealed software-induced artifacts, including artificial succinylation of aspartic acid residues to compensate for sequence mismatches, and incorrect deamidation site assignments due to misinterpretation of isotopic peaks. These findings underscore the necessity for expert manual review of MS/MS data, even when using validated commercial platforms, and highlight the molecular challenges in distinguishing true sequence variants from software-driven artifacts. Full article

Despite the long history of beech (Fagus sylvatica L.) red heartwood research, there has been no experimental proof on the structure of the chromophores yet. For the first time, using high-performance liquid chromatography/diode array detection/multistage electrospray ionization mass spectrometry, it was evidenced that red heartwood chromophores are water/methanol solvent extractable high molecular weight (400–2200 Da) compounds, which are polymerized, transformed, and oxidized products of (epi)catechin and taxifolin. Acid soluble non-extractable polyphenols (flavonoids, tannins) were not evidenced in the cell wall structure, while alkaline soluble compounds (ferulic acid, dehydrodiferulic acid, p-coumaric acid) have been identified for the first time from the sapwood/red heartwood boundary tissues: these supposedly play a role in the structural reinforcement of the cell wall structure and in the antioxidant protection and have a lesser role in color formation. Results on the structure of chromophores and on cell wall composition may enhance color homogenization technologies and contribute to a better utilization of red-heartwooded timber in the future. Full article

Background: A novel triple therapy regimen for Helicobacter pylori eradication, recently approved by the U.S. FDA, comprises vonoprazan (VPN), a potassium-competitive acid blocker, in combination with amoxicillin (AMX) and clarithromycin (CMN). This study presents the development and full validation of a rapid, selective, and sensitive LC-MS/MS method for the simultaneous quantification of these three drugs in spiked human plasma. Methods: Sample preparation was performed using a simple and efficient liquid–liquid extraction (LLE) technique. Chromatographic separation was achieved within 5 min using a Phenomenex Kinetex C18 column (100 × 4.6 mm, 2.6 µm) and a gradient elution system consisting of 0.1% formic acid in water and acetonitrile. Moreover, diazepam was used as an internal standard. The mass spectrometric detection was conducted in multiple reaction monitoring (MRM) mode using positive electrospray ionization. Results: The method exhibited excellent linearity over the investigated concentration ranges (2, 5, 10, 20, 50, and 100 ng/mL for amoxicillin and clarithromycin and 5, 10, 20, 30, 50, and 100 ng/mL for vonoprazan). Intra- and inter-day precision and accuracy values met FDA bioanalytical method validation guidelines, with relative standard deviations and relative errors below 15%. Mean absolute recoveries were above 93% for all analytes. Conclusions: The developed method was fully validated, rapid, selective, and sensitive LC-MS/MS and was assessed using the AGREE tool as a greenness assessment approach, confirming its environmental friendliness and alignment with green analytical chemistry principles. Full article

The leaves of Apocynum venetum L. (A. venetum L.) are a functional food that plays an important role in antioxidation due to its high content of flavonoids and phenolic acids. Therefore, the extraction process of leaves of A. venetum L. is closely related to their activity. In this study, ultra-high-performance liquid chromatography (UHPLC) coupled with diode array detector (DAD), electrospray ionization (ESI), and quadrupole time-of-flight mass spectrometry (QTOF/MS) techniques has been established for qualitative and quantitative analysis of three phenolic acids and six flavonoids in the leaves of A. venetum L. Ultrasonic-assisted extraction conditions for the maximum recovery of phenolic and flavonoid compounds with a high antioxidation effect were optimized by response surface methodology (RSM). The optimum extraction conditions were as follows: ethanol concentration 64%, extraction time 20 min, and liquid-to-solid ratio 16:1 mL/g. The yields of three phenolic acids and six flavonoids under the optimal process were found to be 8.932 ± 0.091 and 20.530 ± 0.198 mg/g, respectively, which matched with those predicted (8.751 and 20.411 mg/g) within a 95% confidence level. Antioxidant activities based on ABTS and DPPH assays showed that the optimal extracts had strong activities compared with those of conventional reflux extraction methods. Moreover, the contribution of total and individual phenolic acids and flavonoids to antioxidant activity was also estimated by Pearson correlation analysis. Full article

Regenerative endodontic procedures (REPs) are a promising treatment for immature teeth with pulpal necrosis. However, the outcomes remain unpredictable, partly due to scaffold limitations. Beta-glucan (BG), a bioactive polysaccharide with regenerative properties, may enhance scaffold performance. This study aimed to fabricate BG-coated polyvinylpyrrolidone/cellulose acetate (PVP/CA) electrospun scaffolds and evaluate their physicochemical properties and cell attachment. Electrospun scaffolds were fabricated by electrospinning a 10% w/v PVP/CA (70:30) solution in acetone and N,N-dimethylacetamide (2:1) (PC). BG (8% w/v in 1 M NaOH) was electrosprayed onto the scaffold at 0.1, 0.2, and 0.4 mL volumes, generating PC-BG01, PC-BG02, and PC-BG04, respectively. Scaffold characterization included SEM, FTIR, BG enzymatic assay, water absorbance, degradation, and cell adhesion assays. SEM images of the scaffolds exhibited smooth cylindrical fibers (547.3–585.9 nm diameter) with high porosity (42.37–49.91%). BG particles were confirmed by elemental analysis and BG enzymatic assay. At 28 days, the PC group showed significant fiber diameter and porosity reduction. BG particle degradation was observed at 14 and 28 days. Notably, BG-coated scaffolds significantly enhanced initial apical papilla cell adhesion at 1 and 24 h. These findings highlight the potential of BG-coated scaffolds as bioactive scaffolds for REPs. Full article

Avicennia marina, commonly known as the grey mangrove, is a salt-tolerant species widely distributed in coastal and estuarine ecosystems. Traditionally, it has been used in folk medicine to treat skin diseases, rheumatism, and ulcers due to its anti-inflammatory and antimicrobial properties. However, comprehensive studies on the chemical constituents and their pharmacological effects remain limited. The dried powder of the aerial parts of A. marina (3.6 kg) was successfully extracted three times with methanol (20 L × 3, each for 2 h) using a multifunctional ultrasonic cleaner operated at 25 °C with a 50% amplitude setting. In this study, the methanolic extract of the aerial parts of A. marina led to the isolation of eight compounds, including two previously unreported iridoid glycosides—avicenosides A and B (1 and 2)—and six known compounds: techtochrysin (3), 7,4′-di-O-methyl-apigenin (4), luteolin (5), kaempferol (6), trans-caffeic acid (7), and 3,4-dihydroxybenzoic acid (8). Their chemical structures were elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and compared with previously published data. Moreover, the absolute configuration of the sugar moieties in the new compounds was also identified. All isolated compounds were evaluated for their cytotoxicity against HepG2 and A549 cancer cell lines. The results indicate potential cytotoxicity of the secondary metabolites from A. marina and provide evidence of their promising role as lead compounds for the development of novel anticancer agents. Full article

Lunasin is a peptide found in the soybean albumin 2S subunit, which has important bioactivities, such as anticancer and antioxidant. Recently, peptides similar to soybean lunasin have been reported in other cereal and legume seeds; for this reason, it is considered important to carry out a review that compiles this information, whose interest lies mainly in the bioactive properties of these peptides. The peptides reported in the literature contained in barley, wheat, rye, triticale, oat, black nightshade, amaranth, bean, chickpea, grass pea, lentil, and pea are analyzed and described. Isolation methods such as ion exchange chromatography, immunoaffinity column chromatography, Western blot, reversed-phase chromatography coupled to an electrospray ionization source, extraction with water and dialysis, and extraction with PBS, and tests such as internalization, radical scavenging, chelating, cytotoxicity in cancer cell lines essays, and histone acetyltransferase inhibition essays were carried out to identify their anticancer properties. It is worth mentioning that the in silico analyses of proteins in which the lunasin-like peptide is located have been developed in some of these seeds; however, more studies are needed in order to confirm sequence similarity to that of the lunasin peptide. Further work is needed in order to identify the sequence of these lunasin-like peptides and corroborate their similarity to that of the lunasin, such as the development of specific antibodies for each lunasin-like peptide reported in each type of seeds. This document aims to compile the advances in the research on lunasin-like peptides and their bioactivities to have a better understanding of the current advances related to these peptides. Full article

Colorectal cancer (CRC) remains a leading global health challenge, with early and accurate diagnosis crucial for effective treatment. Histopathological evaluation, the current diagnostic gold standard, faces limitations including subjectivity, delayed results, and reliance on well-prepared tissue slides. Mass spectrometry imaging (MSI) offers a complementary approach by providing molecular-level information, but its high dimensionality and the scarcity of labeled data present unique challenges for traditional supervised learning. In this study, we present the first implementation of foundation models for MSI-based cancer classification using desorption electrospray ionization (DESI) data. We evaluate multiple architectures adapted from other domains, including a spectral classification model known as FACT, which leverages audio–language pretraining. Compared to conventional machine learning approaches, these foundation models achieved superior performance, with FACT achieving the highest cross-validated balanced accuracy ($93.27\%\pm 3.25\%$) and AUROC ($98.4\%\pm 0.7\%$). Ablation studies demonstrate that these models retain strong performance even under reduced data conditions, highlighting their potential for generalizable and scalable MSI-based cancer diagnostics. Future work will explore the integration of spatial and multi-modal data to enhance clinical utility. Full article

Geum aleppicum Jacq. (yellow avens), a species traditionally used in folk medicine, remains understudied in the ethnopharmacological aspects. In this study, we comprehensively evaluated the phytochemical composition and biological activity of a hydroethanolic (50:50, v/v) extract from the aerial parts of G. aleppicum collected in Kazakhstan. Using the high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS), we identified 24 compounds, predominantly phenolic acids, flavonoids, tannins, and triterpenoids. The major compound was ellagic acid (2.28 mg/g dry extract) as revealed by the reverse phase high-performance liquid chromatography–diode array detector (RP-HPLC-DAD). The extract exhibited a high polyphenol content (131.45 mg GAE/g) and strong antioxidant activity in Ferric Reducing Antioxidant Power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay (3.82 ± 0.07 mmol Fe²⁺/g and 106.61 ± 0.89 mg GAE/g, respectively). Antimicrobial assay of the extract revealed notable antifungal activity against Candida spp., especially against C. glabrata and C. tropicalis with minimum inhibitory concentration (MIC) of as low as 0.125 mg/mL, showing fungistatic effect. Although the extract inhibited the cytopathic effect induced by Human Herpesvirus 1 (HHV-1) in VERO cells, it did not significantly reduce viral replication. Moreover, among human cancer cell lines studied, the extract exerted moderate and selective cytotoxicity against A549 lung cancer cells (CC₅₀ = 75.51 µg/mL, SI = 9). These findings highlight G. aleppicum as a rich source of bioactive compounds, especially phenolics, supporting its potential for development of pharmaceutical and cosmetic applications. Full article

This cross-sectional pilot study aimed to examine associations between urinary metabolites of organophosphate (OP) pesticides and semen quality in 42 healthy young men. Participants answered questionnaires, provided semen and urine samples, and had anthropometric measures taken. Urine and seminal plasma were assayed for dialkylphosphate (DAP) metabolites of OP pesticides using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Semen quality parameters were analyzed according to the World Health Organization protocol, and seminal oxidative stress was assayed using MiOXSYS, a galvanic cell-based technology that yields an integrated measure of oxidants and antioxidants. Associations of OP pesticide metabolites with continuous and dichotomous sperm concentration, percent motility, and percent normal morphology, and with seminal oxidative-reduction potential (ORP) were analyzed statistically. OP pesticide exposure was associated with lower overall semen quality. Specifically, ∑DAP metabolites, driven by diethyl metabolites, was inversely associated with percent sperm motility, but this relationship was not mediated by seminal ORP. Seminal ORP was inversely associated with sperm concentration, but OP pesticide exposure was not associated with seminal ORP. Full article

Grape pomace (GP), a significant by-product of winemaking, is gaining increasing recognition for its potential as a source of bioactive compounds with antioxidant and cardioprotective properties. This study aimed to characterize the polyphenolic profile, fatty acid composition, and antioxidant activity of 17 GP samples from Transylvanian cultivars. Polyphenolic content was determined using the Folin–Ciocalteu method and high-performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC–DAD–ESI MS) analysis. Fatty acid composition was analyzed using gas chromatography with flame ionization detection (GC–FID). Antioxidant capacity was assessed using five methods, which included the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis (3-ethylbenzothialzoline-6-sulfonic acid) (ABTS) radical scavenging, ferric-reducing antioxidant power (FRAP), cupric ion reducing antioxidant capacity (CUPRAC), and reducing power (RP) assays. Additionally, all extracts were analyzed by Fourier transform infrared (FTIR) spectroscopy to identify the presence of functional groups and chemical bonds associated with bioactive compounds. The results showed that Neuburger (NE), Radames (RA), and Regent (RE) cultivars had the highest phenolic concentrations, particularly of catechin, epicatechin, and procyanidin dimers. NE and Feteascǎ Regalǎ (FR) exhibited the greatest radical scavenging and electron transfer activities across multiple antioxidant assays. Rose Blaj (RB) and Astra (AS) displayed the most favorable fatty acid profiles, with high unsaturated-to-saturated fatty acid (UFA/SFA) and hypocholesterolemic-to-hypercholesterolemic fatty acid (H/H) ratios, as well as low atherogenicity (AI) and thrombogenicity (TI) indices, suggesting cardioprotective potential. Additionally, RB and NE cultivars also demonstrated a strong chelation of Cu²⁺ and Fe²⁺ ions, enhancing their antioxidant efficacy by mitigating metal-catalyzed oxidative stress. These findings underscore the potential of GP, particularly from NE, RB, RA, and AS cultivars, the last three of which were homologated in Transylvania at SCDVV Blaj, as valuable sources of health-promoting compounds for use in food, nutraceuticals, and other health-related applications. Full article

The present study develops and optimizes a targeted chromatographic method coupled with mass spectrometry, employing design of experiments, for the determination of several emerging contaminants in environmental waters. Their widespread presence poses environmental and health risks due to their pseudo-persistence and unknown long-term effects. Therefore, sensitive and selective analytical methods are essential for their reliable environmental monitoring. This work focuses on 40 organic micro-contaminants with a wide range of polarities, including drugs, pesticides and UV-filters. Chromatographic separation was performed on a pentafluorophenyl column, and a Face-Centered Design was applied for multivariate optimization. Mobile phase flow and temperature were chosen as the study factors, and retention time and peak width as the responses, as indicators of analytical performance. Two optimized runs (for positive and negative electrospray ionization modes) were obtained, enabling the analysis of all 40 analytes in a total of 29 min. The final method was successfully applied to seawater samples from different sites of the Genoa harbor area. Several analytes were detected and quantified, down to the ng L⁻¹ level, with tracers and pharmaceuticals showing the highest concentrations. The method demonstrated satisfactory accuracy, precision and specificity and is suitable for routine monitoring of a broad range of emerging contaminants in seawater. Full article

The bark of Dillenia indica L. is a rich source of phenolic and triterpenoid compounds, including betulinic acid (BA), known for their antioxidant and anti-aging properties. This study investigated the antioxidant potential of a BA-enriched extract through a multidisciplinary approach combining computational, experimental, and cell-based evaluations. Molecular docking and molecular dynamics simulations revealed that BA binds stably to Kelch-like ECH-associated protein 1 (KEAP1), suggesting activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Extraction conditions were optimized using response surface methodology (RSM) and artificial neural network (ANN) modeling, yielding the maximum total phenolic content (TPC; 85.33 ± 2.26 mg gallic acid equivalents/g) and total flavonoid content (TFC; 75.60 ± 1.66 mg catechin equivalents/g), with ANN demonstrating superior predictive performance compared to RSM. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) confirmed the presence of BA in the optimized extract. Simulated gastrointestinal digestion revealed reductions in TPC, TFC, and radical scavenging activity during the gastric phase. In ultraviolet B (UVB)-irradiated human keratinocyte (HaCaT) cells, the optimized extract significantly reduced intracellular reactive oxygen species (ROS) and upregulated the KEAP1-Nrf2-heme oxygenase-1 (HO-1) pathway, confirming its antioxidant mechanism. These findings highlight the extract’s stability, bioactivity, and mechanistic efficacy, supporting its application as a nutraceutical ingredient for combating oxidative stress and skin aging. Full article

Propolis, a natural bee-derived product rich in diverse phytochemicals with potential therapeutic benefits, remains underexplored in Algeria. This study investigated the molecular profile, antioxidant capacity, and antibacterial activity of propolis sourced from two bioclimatically distinct Algerian regions (humid subtropical Batna and hot desert Biskra) using electrospray ionization mass spectrometry, ultra-high-performance liquid chromatography with diode array detection, and gas chromatography–mass spectrometry. Significant regional variations were observed, with propolis extract 2 (PE2) exhibiting a higher bioactive content, including a constituent not previously reported in propolis. Antioxidant assays (2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing antioxidant power, and phenanthroline) demonstrated that PE2 consistently outperformed propolis extract 1 and the reference standards (DPPH IC₅₀: 27.74 µg/mL; FRAP: 5.16 µg/mL). Antibacterial testing demonstrated potent bactericidal effects, particularly for PE2, with minimum inhibitory concentration values equivalent to the minimum bactericidal concentrations required against Staphylococcus aureus ATCC 25923 (18.75 µg/mL) and Escherichia coli ATCC 25922 (133 µg/mL). Molecular docking identified nine bioactive compounds with high KEAP1 binding affinity, with 1,3-O-caffeoyl-dihydrocaffeoylglycerol (first time reported in propolis) showing the strongest binding affinity (−11.02 Kcal/mol). In silico pharmacokinetic predictions further verified its drug-like properties. These findings suggest the tested Algerian propolis samples, as a source of natural alternative antioxidants and antimicrobials, provide a basis for future research in drug discovery and development. Full article

The identification of plant oils in polychrome cultural relics is crucial for understanding historical craftsmanship and for developing appropriate conservation strategies. Historically, plant oils were used as binders, protective coatings, and plasticizers, directly influencing the stability and appearance of artifacts. Their degradation—through oxidation, hydrolysis, and environmental exposure—makes accurate detection challenging. Recent advances in spectroscopic methods (Fourier-Transform Infrared Spectroscopy, Raman), chromatographic techniques (Gas Chromatography–Mass Spectrometry, High-Performance Liquid Chromatography), and mass spectrometry imaging (Desorption Electrospray Ionization—Mass Spectrometry Imaging) enable non-invasive or minimally invasive analysis of oils, even within complex matrices. Case studies, including the Meiwu ceiling of the Palace Museum and resin–oil varnishes, illustrate how multi-method approaches improve reliability. Ongoing challenges include interference from degradation products, limited sampling due to ethical concerns, and the absence of comprehensive reference libraries. Future research should prioritize non-destructive techniques, standardized protocols, and interdisciplinary collaboration to enhance the precision and applicability of plant oil identification in cultural heritage conservation. Full article