Search PubMedSearch

SEARCH · Search PubMed

Results for “Gas Chromatography-Mass Spectrometry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

211 records · Page 2Linked to original sources

Effects of aerosol aging on composition and light-absorbance of nitrogen-containing organic compounds: Evidences from ultra-high-resolution mass spectrometry analysis.

Nitrogen-containing organic compounds (NOCs) are key components of particulate matter (PM), but their compositional evolution and light-absorbing properties during atmospheric aging remain poorly understood. In this study, ultra-high-performance liquid chromatography coupled with Orbitrap mass spectrometry was used to semi-quantitatively analyze 59 PM1 samples collected in Shanghai. NOCs accounted for 31 % and 64 % of the detected species in negative (ESI-) and positive (ESI+) ionization modes, respectively. Atmospheric aging significantly reduced the molecular diversity of polar organics, with both the number and mass concentration percentages of CHON- compounds showing significant negative correlations with aging degree. Van Krevelen analysis demonstrated a decrease in the number of carboxylic-rich alicyclic molecules and their CHON- contributions during the aging process (from 37.7 % in fresh samples to 21.2 % in aged samples). CHN+ compounds, a major NOCs group in ESI+ mode, also decreased with aging. Correlation analyses involving the Bep/(Bep+Bap) ratio, relative humidity, and mass absorption efficiency at 365 nm revealed a decline in light absorption capacity with aging, suggesting aqueous-phase oxidation as a dominant aging mechanism. CHON- and CHN+ compounds were identified as the principal light-absorbing constituents in PM1. This work provides new insights into the aging-induced transformations of NOCs in urban PM1, and their changing role in light absorption, highlighting the need for further investigation of the aging mechanisms of NOCs.

Aerosols

Unravelling bioanalytical innovations, degradation processes, and impurity landscapes of VEGFR inhibitors.

From pre-formulation studies to clinical trials, VEGFR-targeted small-molecule tyrosine kinase inhibitors (TKIs) require rigorous analytical standards. Bioanalysis, stability-indicating studies, and impurity profiling are used to examine chromatographic advances for VEGFR-targeted TKIs like sunitinib, pazopanib, axitinib, sorafenib, cabozantinib, vandetanib, apatinib, lenvatinib, nintedanib, and regorafenib. An LC-MS/MS and UPLC-MS/MS routinely show sub ng/mL performance, as shown by LLOQs (0.2 ng/mL) for sunitinib and axitinib, 1 ng/mL for pazopanib, 5-7 ng/mL for sorafenib, 0.5-1.5 ng/mL for regorafenib metabolic products, and 0.1-0.5 ng/mL for lenvatinib. These approaches are used for pharmacokinetics and therapeutic drug monitoring due to their good correlation coefficient of 0.1-10,000 ng/mL, accuracy of 95%-108%, and precision of 15% RSD. UPLC-QTOF-MS/MS distinguishes degradants and metabolites during forced degradation studies, enabling structural elucidation following ICH M7 risk evaluation protocol. HPTLC/MLC offers fast, sensitive screenings, while RP-HPLC/DAD or HPLC-UV offer reliable, cost-effective routine quality-control solutions with LOD/LOQ in the μg/mL range and linearity of 10-240 μg/mL. This review lists the structures and CAS numbers of ten VEGFR-2 TKI degradants and metabolites, as well as pharmacopeial impurities in SMILES forms. It will be useful for future method development and regulatory applications. To ensure VEGFR-targeted TKI quality, safety, and therapeutic efficacy, LC-MS/MS for trace quantification and HRMS for structure elucidation provide a robust, future-oriented framework. To improve VEGFR-targeted TKI quality, safety, and regulatory compliance, analytical development should focus on HRMS-based impurity characterization, AI-assisted degradation prediction, green chromatography, and harmonized bioanalytical validation.

Humans

Development and validation of an LC-MS/MS method for the quantification of the KRASG12C inhibitor divarasib.

Divarasib is a newly developed covalent KRASG12C inhibitor, currently under clinical investigation in a phase 3 trial in patients with non-small cell lung cancer (NSCLC). At the moment, very limited pharmacokinetic data are publicly known. However, obtaining more insight into the pharmacokinetic properties of divarasib is important, since this may provide a better understanding of its efficacy and safety risks. Pre-clinical studies have been performed in mouse models to evaluate the effect of drug transporters and drug-metabolizing enzymes on the plasma exposure and tissue distribution of divarasib. Therefore, a reliable quantification method is required. To our knowledge, no bioanalytical assay of divarasib has been published yet. Therefore, in this study we developed and validated an assay to quantify divarasib in human plasma and in eight different mouse-related matrices, and partially in mouse plasma, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was initially evaluated over a concentration range of 1-10,000 nM. However, due to carry-over observed at 10,000 nM, the validated calibration range was established at 1-2000 nM, with matrix-dependent LLOQs of 1-10 nM. Erlotinib was used as an internal standard and acetonitrile was utilized to perform protein precipitation as sample pretreatment. Divarasib demonstrated stability in human plasma and in mouse plasma and tissue homogenates under various experimental conditions. A pilot in vivo study showed the applicability of our validated LC-MS/MS method. Ongoing clinical trials may collect plasma samples, and this developed method enables quantification of divarasib in both mouse and human plasma samples.

Animals

Aflatoxins and their biosynthetic precursors in lotus seeds: simultaneous UPLC-MS/MS determination, contamination profiling, and matrix-specific accumulation during Aspergillus flavus infection.

Aflatoxin (AF) contamination poses a severe global threat to food and medicinal material safety, yet existing research focuses on terminal AF metabolites while neglecting residual biosynthetic precursors, leading to potential underestimation of contamination risks. In this study, a UPLC-MS/MS method was established for the simultaneous quantification of six AFs and their five precursors in lotus seeds, with optimization of mass spectrum parameters, chromatographic separation conditions, and sample pretreatment. Method validation confirmed linearity (R2&#xa0;>&#xa0;0.99), LODs (0.03-0.36&#xa0;&#x3bc;g/kg), and recoveries (76.53%-120.0%, RSD&#xa0;<&#xa0;15%). Analysis of 41 natural lotus seed samples revealed a 63.4% AF contamination rate, dominated by B-group AFs, while O-methylsterigmatocystin (OMST) and versicolorin hemiacetal (VOH) were identified as the primary co-residual precursors with co-occurrence rates &#x2265; 50%. Notably, AFM1 was predominantly detected in natural samples with AFB1 concentrations exceeding 100&#xa0;&#x3bc;g/kg. Artificial inoculation experiments further demonstrated that sterilization and sealing conditions modulated AF biosynthesis in lotus seeds, with non-sterilized and non-sealed groups showing delayed fungal metabolism and lower toxin accumulation. A significant linear correlation was observed between AFM1 and AFB1 levels (r&#xa0;=&#xa0;0.94) in infected samples, demonstrating their accumulation levels are coupled with fungal overall metabolic flux. Given the high co-occurrence rate of OMST/VOH with AFB1 in natural samples, their individual and combined toxicities require in-depth investigation. This work deciphers matrix-specific AF dynamics in lotus seeds, supporting regulatory standard refinement (e.g., precursor inclusion) and targeted control (e.g., time-sensitive drying after harvest). Further studies will focus on exploring the molecular mechanisms of substrate-dependent AF synthesis.

Aflatoxins

Determination of 13 per- and polyfluoroalkyl substances in human plasma samples using LC-MS/MS: application to capillary microsamples.

Per- and polyfluoroalkyl substances (PFAS) are chemicals widely applied in industrial processes and highly persistent in the environment, whose extensive use has been linked to adverse health effects. Venous plasma is the conventional matrix for PFAS assessment in blood, and LC-MS/MS is the most used quantification technique. Despite the relevance of this topic, biomonitoring data on human exposure to PFAS in Brazil remain limited. This study validated an LC-MS/MS method for determination of 13 PFAS in human plasma. Blood samples were collected from volunteers by phlebotomy, followed by protein precipitation with acetonitrile containing 1% formic acid (v/v) and solid-phase extraction. Chromatographic separation was achieved on an Acquity UPLC HSS T3 column. The assay was linear over a calibration range of 0.2-20&#xa0;ng/mL. Intra- and inter-assay precision (CV%) were within the ranges of 2.06-12.0% and 0.25-10.7%, respectively. As for accuracy, results were 89.0-112.9%. Matrix effect ranged from -1.31 to 0.05%. Stability after four freeze/thaw cycles and under autosampler conditions were also confirmed for all analytes. The method was applied to 40 paired venous and capillary plasma samples. Both measures exhibited high correlation (r&#xa0;=&#xa0;0.926). PFOS was the only compound detected at concentrations &#x2265;0.2&#xa0;ng/mL (LLOQ) in all samples, with capillary plasma concentrations of 0.85-13.50&#xa0;ng/mL. In summary, the method showed good validation performance and demonstrated the suitability of capillary plasma samples as an alternative matrix for PFAS quantification.

Humans

A streamlined workflow for high throughput metaproteomic analysis of the rumen microbiome.

Metaproteomics can provide direct functional insights into complex microbial communities, yet its application in rumen research remains limited due to labor-intensive and low-throughput sample preparation workflows before the MS analysis. This work aimed to develop and characterize a streamlined, high throughput metaproteomic workflow optimized for rumen samples. Key steps, including microbial cell extraction, cell lysis, protein digestion, and LC-MS/MS acquisition, were systematically assessed and optimized to reduce hands-on time while maintaining deep proteome coverage. The optimized workflow integrates a minimized cell extraction protocol using 0.5&#xa0;g starting material and in-solution tryptic digestion. Application of the final workflow to 72 samples from in vitro fermentation revealed that biological variability between inocula dominated technical variability, which remained moderate (median CV of 21-24% across batches). Overall, the optimized workflow supports robust taxonomic and functional characterization of the rumen microbiome with improved scalability. These advances provide a foundation for applying metaproteomics to larger experimental designs, including nutritional trials and cohort studies, thereby enabling broader functional interrogation of rumen microbial ecosystems. SIGNIFICANCE: This study addresses current limitations in the application of metaproteomics to rumen microbiome research by developing a streamlined and scalable sample preparation workflow. By optimizing key steps and reducing sample input while maintaining reproducibility and proteome coverage, this work enables more efficient processing of larger sample sets. These advances support the broader use of metaproteomics in rumen studies and facilitate functional investigations relevant to animal nutrition and sustainable livestock production.

Animals

A prospective pharmacokinetic interaction study between rifampicin and fusidic acid for the treatment of staphylococcal infections.

OBJECTIVE: Fusidic acid with rifampicin is used for the treatment of severe staphylococcal infection, particularly prosthetic joint infections. Previous studies using twice daily fusidic acid showed rifampicin increases fusidic acid clearance, potentially causing sub-therapeutic concentrations. It is uncertain whether this occurs with three-times daily dosing. This study sought to re-evaluate this potential drug-drug interaction. METHODS: In this prospective, open-label drug-drug interaction population pharmacokinetic (PK) study, participants were randomized to receive fusidic acid or rifampicin for 24&#x2005;hours, followed by combination therapy for the duration of treatment. Drug concentration assays used liquid-chromatography mass spectroscopy on dried blood spots. Population PK models were built for fusidic acid, rifampicin and 25-desacetyl rifampicin. RESULTS: Ten participants were recruited. Inter-individual variability for both absorption (98.1%) and clearance (77.8%) were high for fusidic acid. A population pharmacokinetic model for fusidic acid revealed that early autoinhibition dominated over later rifampicin-mediated induction, resulting in a net decrease in fusidic acid clearance. The mean fusidic acid area under the curve during each dosing interval (AUC&#x3c4;) at steady state was 1.76-fold [0.049, 34.918] higher relative to Day 1, despite high uncertainty.Large inter-individual (110%) variability in absorption was observed for rifampicin. There was no apparent effect on rifampicin metabolism by fusidic acid co-administration, however, fusidic acid decreased clearance of 25-desacetyl rifampicin. CONCLUSION: In patients treated with fusidic acid three times daily in combination with rifampicin, autoinhibition potentially counteracted rifampicin induction such that fusidic acid concentrations were not reduced. Rifampicin clearance was not affected by fusidic acid, but 25-desacetyl rifampicin clearance was decreased. There was large inter-individual variability in the observed concentrations and final parameter estimates.

Fusidic Acid

Bioepidemiology of cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis, primarily due to immunoglobulin light chain (AL) or transthyretin (ATTR) amyloid, is an increasingly recognized cause of heart failure. Modern diagnostic advances suggest that ATTR, particularly in older adults, may be more prevalent than historically reported. METHODS: All Olmsted County decedents aged &#x2265;40 years from 1970 to 1976 were identified. Available ventricular myocardium from retained paraffin blocks was screened histologically for amyloid using sulfated Alcian blue staining; positive cases underwent grading and proteomic typing by laser microdissection coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Beyond prevalence estimation, this analysis characterizes amyloid type, deposition grade and distribution, associated comorbidities, and cause-of-death patterns, comparing amyloid-positive decedents with age- and sex-matched controls. RESULTS: Of 2,566 eligible deaths, 1,028 autopsy cases with evaluable myocardium formed the study cohort (mean age 70.5 years; 61.1% male; 97% White). Cardiac amyloid was present in 52 cases giving an overall prevalence of 5.1% (95% CI: 3.8-6.6, which rose from 0% under age 60 to 37.5% (95% CI: 21.1-56.3) in those &#x2265;90 years (p < 0.001). While prevalence estimates were higher in men above age 80 compared to women, there was no evidence of an interaction of age and sex (p = 0.90). The quantity of amyloid was sufficient for typing in 38 cases: ATTR (84.2%), AL (7.9%), serum amyloid A (5.3%), and apolipoprotein A-IV (2.6%). Adjusted estimates assuming untyped mild cases were ATTR-type increased ATTR prevalence to 4.5% (95% CI: 3.3-5.9) overall. Comorbidity profiles were similar between amyloid-positive and negative groups, though syncope and leg weakness were more common in amyloid-positive decedents. CONCLUSIONS: In an unselected autopsy cohort, cardiac amyloid was common, particularly ATTR in older adults. Prevalence increased steeply after age 80. These findings suggest that ATTR amyloidosis is not rare and is likely underdiagnosed and has similar prevalence in women and men, despite the male predominance reported in the literature.

Humans

Dynamic lysine acetylation and succinylation of platelet proteins regulates platelet storage lesion: mechanistic insights from multi-omics.

OBJECTIVES: Platelet storage lesion (PSL) severely impairs platelet function during storage, presenting a major hurdle in transfusion medicine; however, the dynamic interplay between global proteomic changes and post-translational modifications (PTMs) underlying these functional deteriorations remains insufficiently characterized. Here, we report the first comprehensive multi-omics analysis integrating global proteomics, acetylomics, and succinylomics to dissect the molecular dynamics during platelet storage. METHODS: We performed quantification of global proteomics, acetylome and succinylome based on TMT-labeled LC-MS/MS analysis, combined with antibody-affinity enrichment and purification. Dynamic molecular changes and functional transformation of platelet were also characterized under proper conditions stored for 1, 3, 5, 7&#x2009;days, respectively. RESULTS: We systematically characterized 3,609 proteins, 1,308 acetylation sites, and 1,947 succinylation sites across multiple storage time points (D1, D3, D5, D7). We distinct temporal patterns of post-translational modifications, with succinylation showing more extensive coverage than acetylation in platelets. Pathway enrichment analysis revealed extensive metabolic reprogramming involving complement activation, energy metabolism, and cellular detoxification processes. The identification of specific motif patterns provided mechanistic insights into the functional specificity of these modifications. Random forest machine learning identified 20 core regulatory proteins representing critical nodes in PSL development. Furthermore, we employed real - time quantitative polymerase chain reaction (RT - QPCR) to measure the expression levels of key genes related to platelet function and PTM - associated pathways. CONCLUSION: By mapping the interplay between proteomic abundance shifts and PTM dynamics, this study provides a multidimensional understanding of PSL, establishing a foundational framework for optimizing storage protocols and enhancing transfusion safety.

Blood Platelets

Proteomic characterization of the acquired enamel pellicle under acidic challenges at early and mature formation stages.

OBJECTIVES: This study aimed to characterize acquired enamel pellicle (AEP) proteomic changes after exposure to citric acid (CA) and hydrochloric acid (HCl) under different pellicle formation times (3 and 120&#x202f;min) in the same volunteers. DESIGN: Nine healthy volunteers participated in this randomized crossover in vivo study. The AEP was allowed to form for 3 or 120&#x202f;min and subsequently exposed for 10&#x202f;s to deionized water (control), 1% CA (pH 2.5), or 0.01&#x202f;M HCl (pH 2.0). Pellicle samples were collected, followed by protein extraction, tryptic digestion, and analysis by nanoliquid chromatography (nanoLC) coupled to mass spectrometry (MS) with MSE (data-independent acquisition; nanoLC-MS&#x1d31;). Label-free quantitative proteomics were performed for relative quantification using t-test (p&#x202f;<&#x202f;0.05). RESULTS: At 120&#x202f;min, CA exposure markedly reduced several typical AEP proteins, especially acidic proline-rich proteins (PRPs). Conversely, basic PRPs were upregulated, suggesting acid-resistance protein signature. At 3&#x202f;min, basal-layer proteins (PRPs, cystatins, histatins and mucins) were more abundant. Hemoglobins increased 6-8-fold (up to 150-fold in 3&#x202f;min control), suggesting association with early pellicle formation and an acid-resistant protein signature. CA exposures for 120&#x202f;min also upregulated typical AEP proteins (PRPs, mucins, cystatins, immunoglobulins), while HCl exposure depleted albumins and lactotransferrin. CONCLUSION: Intrinsic and extrinsic acids induce distinct proteomic signatures in the AEP. Hemoglobin and PRPs appear consistently enriched in the early pellicle layer, reflecting an initial acid-resistant protein signature. These findings provide new insights into the molecular remodeling of the AEP following intrinsic and extrinsic acid exposure, highlighting proteins potentially involved in early-stage pellicle formation.

Humans

Transpulmonary proteomic gradient analysis in women with pulmonary arterial hypertension associated with systemic sclerosis.

This study investigated proteomic alterations in the pulmonary circulation of patients with pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) by analyzing the transpulmonary protein gradient and comparing the proteomic profiles with systemic sclerosis (SSc) without PAH. Twenty women were included (10 PAH-SSc, 64.6&#xa0;&#xb1;&#xa0;10.8&#xa0;years; 10 SSc, 62.8&#xa0;&#xb1;&#xa0;11.5&#xa0;years). The transpulmonary gradient was defined as the difference in biomarker concentrations between wedge-position and pulmonary artery blood samples. Peptides were analysed using liquid chromatography-mass spectrometry, and differentially abundant proteins were identified with Proteome Discoverer. Protein-protein interaction networks were generated with STRING and visualized in Cytoscape. A total of 270 proteins were detected, with no significant transpulmonary gradient alterations. However, patients with PAH-SSc showed distinct proteomic profiles compared to SSc. Multivariate analysis identified 48 differentially abundant proteins in pulmonary artery plasma, with 15 overrepresented and 33 downregulated in PAH-SSc. Among these, the downregulation of transforming growth factor-beta-induced protein ig-h3 (TGF&#x3b2;I/ig-h3) points to a potential involvement of the TGF-&#x3b2;-related extracellular matrix remodelling pathway in PAH-SSc. However, further validation in larger and independent cohorts is required before its relevance as a biomarker or therapeutic target can be established. In conclusion, while no transpulmonary proteomic gradient was observed, the proteomic profiles of PAH-SSc and SSc were different. The profile in PAH-SSc was characterized by differences in immune response, lipid metabolism, and hemostatic proteins. SIGNIFICANCE: This study offers the first proteomic characterization of the transpulmonary gradient in PAH-SSc and SSc. Although no differences in the gradient were found, the pulmonary artery plasma proteome of PAH-SSc patients showed a distinct pattern compared to SSc. Several proteins associated with immune function, haemostasis, and cellular processes were altered, which may indicate specific pathophysiological features of PAH-SSc or suggest how lung dysfunction develops in SSc. Targeting dysregulated proteins like TGF&#x3b2;I/ig-h3 or addressing immune-coagulation imbalances may support future research studies. Overall, these findings refine the molecular profile of PAH-SSc and provide a basis for future large-scale studies aimed at clarifying disease mechanisms and identifying clinically relevant molecular signatures.

Humans

Variability and ozone formation potential of ambient non-methane hydrocarbons in a tropical semi-arid atmosphere of northwest India.

We present first-time measurements of twenty-six ambient non-methane hydrocarbons (NMHCs; C2-C8), including isoprene (C5H8), at a semi-arid site in northwest India (Ajmer; 26.45&#xb0;N, 74.64&#xb0;E), during January 2022-December 2023. Ambient samples were analyzed using a thermal desorption gas chromatography system equipped with dual flame ionization detectors. Daily total NMHC levels ranged from 6 ppbV to >100 ppbV. Most NMHCs, except isoprene, toluene, ethylbenzene, m-xylene and o-xylene, exhibited the highest levels in winter and the lowest in the monsoon. In contrast, others were highest in the pre-monsoon and toluene was highest during monsoon. These variations reflect the combined influence of emissions, chemistry and meteorology. Toluene and o-xylene were the dominant NMHCs (25 %-67 %). Correlation analyses indicated major contributions from liquefied petroleum gas (LPG) and vehicular emissions, with additional influence from urban and oil and natural gas activities. Compared with other Indian sites, NMHCs levels at Ajmer were 2-5 times lower than Ahmedabad and Udaipur and 10 times lower than Delhi. The total ozone formation potential was highest in the monsoon (about 175 ppbV) and lowest in the post-monsoon (about 55 ppbV), with dominance of o-xylene (24 %-33 %) and toluene (8 %-37 %). Propylene-equivalent concentrations were highest in the pre-monsoon (30.23 ppb C) and lowest in the post-monsoon (7.28 ppb C). Similarly, OH reactivity was highest in the pre-monsoon (19.58 s&#x207b;&#xb9;) and lowest in the post-monsoon (4.71 s&#x207b;&#xb9;), dominated by benzene and toluene. These findings emphasize the importance of NMHC chemistry in a climatically sensitive region and highlight the need for their continuous monitoring.

India

Simultaneous determination of imiquimod and terbinafine in skin permeation studies: Validation of a liquid chromatography method with fluorescence detection.

Chromoblastomycosis is a chronic, neglected subcutaneous mycosis posing significant therapeutic challenges. A topical strategy combining terbinafine (TBF), an antifungal, with imiquimod (IMQ), a TLR-7/8 agonist immunomodulator, has emerged a promising alternative. However, no validated analytical method is currently available to simultaneously quantify both drugs in skin, which is crucial for novel formulation development. This study reports the development and validation of a simple HPLC method with fluorescence detection (excitation 236&#xa0;nm, emission 340&#xa0;nm) for the simultaneous determination of TBF and IMQ extracted from porcine skin. Separation was achieved on a C8 reversed-phase column (125&#xa0;&#xd7;&#xa0;4.0&#xa0;mm, 5&#xa0;&#x3bc;m) using a mobile phase of methanol and water (60,40, v/v), both containing 0.1% formic acid at a flow rate of 0.8&#xa0;mL/min. The method showed excellent linearity (r&#xa0;>&#xa0;0.999) over 0.01-1.0&#xa0;&#x3bc;g/mL for IMQ and 0.1-2.0&#xa0;&#x3bc;g/mL for TBF. Intra- and inter-day precision demonstrated coefficients of variation below 5%, and recovery rates from skin (79-105%) confirmed accuracy. Limits of detection were 0.001&#xa0;&#x3bc;g/mL for IMQ and 0.004&#xa0;&#x3bc;g/mL for TBF, with quantification limits of 0.02&#xa0;&#x3bc;g/mL and 0.16&#xa0;&#x3bc;g/mL, respectively. This selective, sensitive, and reproducible method represents a valuable analytical tool for supporting the development and quality control of topical formulations for chromoblastomycosis and other fungal skin diseases.

Animals

A Phase I Study Assessing the Safety, Tolerability, and Pharmacokinetics of Yinfenidone: A Novel, Potent Drug for Idiopathic Pulmonary Fibrosis Treatment in Healthy Chinese Subjects.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease with a median survival of only 2-3 years after diagnosis. Yinfenidone (HEC585) possesses the potential to inhibit the proliferation of pulmonary fibroblasts, making it a promising candidate for the treatment of IPF. This study assessed the safety, tolerability, pharmacokinetics, and metabolic profile of Yinfenidone hydrochloride capsule in healthy Chinese subjects. METHODS: This single-center, randomized, double-blind, placebo-controlled, single ascending-dose trial included seven dose groups(20, 50, 100, 200, 400, 600, and 800 mg). Each group enrolled8 healthy subjects: 6 received Yinfenidone hydrochloride capsules and 2 received matching placebo under fasting conditions. Serial pharmacokinetic (PK) blood samples were collected pre-dose and post-dose, liquid chromatography-tandem mass spectrometry was used to analyze the plasma concentrations of Yinfenidone. Additionally, metabolic biotransformation of Yinfenidone in plasma were conducted in the 100 mg dose group. Safety and tolerability endpoints were monitored via physical examinations, vital signs measurements, clinical laboratory tests, 12-lead electrocardiography (ECG), and adverse events (AEs) documentation throughout the trial. FINDINGS: Yinfenidone was rapidly absorbed, with a median maximum plasma concentration (Tmax) of 1.8-3.0 hours, and had a mean half-life (t1/2) ranging from 31.9 to 62.0 hours. Within the 20-100 mg dose range, systemic drug exposure generally increased with ascending dose, above 100 mg, exposure increased less than proportionally to dose. Metabolite profiling in the 100 mg group revealed that the parentcompound predominated in plasma, with metabolic pathways including mono-oxygenation and N-dealkylation. All reported AEswere mild, classified as Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 grade 1. No serious AEs observed; no subject discontinued the trial due to AEs. Single oral doses of 20-800 mg Yinfenidone hydrochloride capsules administered under fasting conditions demonstrated favorable safety and tolerability profiles in healthy Chinese subjects. IMPLICATIONS: Yinfenidone exhibited rapid absorption (median Tmax, 1.8-3.0 hours) and a long terminal t1/2 ranging from 31.9 to 62.0 hours in this single ascending-dose study, indicating that Yinfenidone can be taken once a day in subsequent clinical studies. Yinfenidone mainly exists in human plasma as the original drug and is metabolized through a variety of metabolic pathways. The AEs observed with Yinfenidone in this study, such as diarrhea, nausea, and dizziness, were similar to those reported with pirfenidone. Overall, Yinfenidone demonstrated a favorable safety and tolerability profile in this cohort of healthy subjects.

Adult

In situ product monitoring in heterogeneous reaction of gaseous trimethylamine on Fe2O3/Fe(NO3)3: Effect of environmental factor and particle property.

Gas-particle reactions represent an important atmospheric heterogeneous transformation process for organic amines (OAs). Environmental factors and particle properties may impact the gas-particle reaction products. Although the products from gas-particle reactions can be monitored by various in situ techniques, related data remain scarce. Here, the interfacial and gaseous products from the reaction of trimethylamine on Fe2O3/Fe(NO3)3 particles under light irradiation with mixed NO2, O2, SO2 and H2O were monitored using in-situ diffuse reflectance Fourier transform infrared spectroscopy and proton transfer reaction time-of-flight mass spectrometry. Dark reaction of gaseous trimethylamine on Fe2O3/Fe(NO3)3 generated two interfacial products types: N-containing ones (CH3NCH2, CH3NO2, (CH3)2NCHO, and CH3N(OH)CHO) and N-free ones (alcohols, aldehydes and acids), both accumulating with reaction progression. Light irradiation and O2 oxidation enhanced formation of these products, while NO2 promoted the production of CH3NO2 and (CH3)2NCHO. H2O and SO2 occupied the active sites of particles to inhibit the formation of all products. Compared to Fe(NO3)3, Fe2O3 showed absolute dominance in contribution to the formation of products. Considering the smaller particle size of Fe2O3 and excess Fe(NO3)3, the physical mixing of them reduced the generation of interfacial products. Furthermore, gaseous products of CH3OH, HCHO, CH3CHO, HCOOH and CH3COOH detection clarified the N-free interfacial products. The presence of Fe(NO3)3 inhibited the formation of HCOOH and favored the formation of CH3CHO in the gas phase. By combining product information with thermodynamic calculations, the heterogeneous reaction pathways of trimethylamine were tentatively proposed. These findings provide a guiding significance for the migration of OAs in real atmospheric environment.

Methylamines

Community-driven advances in computational mass spectrometry: The perspective of EuBIC-MS members.

Advances in data acquisition, artificial intelligence, and integrative bioinformatics are driving the rapid evolution of computational mass spectrometry, and in turn, transforming modern proteomics, metabolomics, and lipidomics. These developments have greatly increased the scale and complexity of mass spectrometry data, underscoring the importance of evolving accurate, transparent, efficient and reproducible data processing workflows. Addressing these challenges requires collaborative innovation that brings together expertise in software engineering, statistics, and biology. The European Bioinformatics Community for Mass Spectrometry (EuBIC-MS), an initiative of the European Proteomics Association (EuPA), fosters a culture of open, community-driven development through its biennial Developers Meetings and Winter Schools. This commentary summarizes the scientific background and outcomes of the EuBIC-MS Developers Meeting 2025, which took place in Novacella, Italy. Three keynote presentations highlighted major frontiers in the field: deep proteome and phosphoproteome profiling, text mining for protein-protein interaction extraction, and scalable proteomics for AI-driven drug discovery. Seven community-selected hackathons addressed emerging challenges such as single-cell proteomics data analysis, FAIR metadata extraction, deep learning frameworks, R-Python interoperability, and DIA validation. Together, these efforts demonstrate the potential for scientific and technical innovation to arise from open collaboration, and highlight how community-driven initiatives can accelerate progress in computational mass spectrometry. SIGNIFICANCE: Modern proteomics increasingly depends on computational advances to translate complex, high-dimensional data into biological knowledge. The EuBIC-MS Developers Meeting 2025 exemplifies how community-driven collaboration can directly accelerate this process by bringing together experts from bioinformatics, statistics, and experimental proteomics to co-develop open, interoperable, and reproducible analytical tools. By fostering shared software frameworks, transparent benchmarking, and collaborative problem solving, the EuBIC-MS community helps ensure that technological innovation translates into reliable biological insights. This collaborative model strengthens the foundation for quantitative, system-level understanding of proteomes and establishes a sustainable path for integrating artificial intelligence and next-generation data acquisition into routine biological discovery. This commentary shows some current highlights in the field of computational mass spectrometry and community-based approaches undertaken during the most recent Developers Meeting to solve these challenges. The approaches discussed and initiated during the meeting - ranging from deep proteome profiling and phosphosite mapping to text mining, single-cell data analysis, and FAIR metadata extraction - address key bottlenecks that currently limit the biological interpretability and comparability of proteomics data.

Mass Spectrometry

LC-IMS-MS profiling of avocado acetogenins reveals tissue-dependent distribution and cultivar-specific metabolic signatures.

This study presents a comprehensive characterisation of acetogenin-related metabolites in avocado using an LC-IMS-MS workflow. A total of 26 metabolites were semi-quantified across peel, pulp and seed tissues from three cultivars (Hass, Bacon and Fuerte). The integration of ion mobility spectrometry enabled the generation of the first experimental database of collision cross section (CCS) values for avocado acetogenins, improving confidence in metabolite annotation. Results revealed a pronounced tissue-dependent distribution, with seeds and pulp as the primary reservoir of several acetogenins, whereas the peel consistently exhibited lower concentrations. In contrast, acetogenin levels remained largely stable throughout ripening. Clear cultivar-dependent differences were observed, with Hass displaying a distinct metabolic profile compared to Bacon and Fuerte. Multivariate analysis confirmed these findings, showing tissue-dependent cultivar differentiation. This study provides new insights into avocado chemical diversity and highlights the potential of avocado by-products as consistent and promising sources of bioactive acetogenins.

Persea

First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes.

Understanding intraspecific venom variation requires distinguishing the contributions of neutral population history from natural selection. This study aims to determine whether venom variation in Vipera ammodytes species complex is structured across eight phylogenetic groups. Despite a complex evolutionary history, venom composition did not differ among phylogenetic groups within the analytical framework used, suggesting that shared ancestry alone does not explain venom variation. Whether local adaptation to environmental conditions explains the observed variation remains an open question for future studies.

Animals