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Keywords = ultrahigh resolution mass spectrometry

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25 pages, 8658 KB  
Article
Predicting and Co-Optimizing the Taste and Aroma of Green Tea During Spreading Using the TabPFN Model
by Haotian Qian, Xinyao Yang, Pengcheng Zheng, Shengpeng Wang, Rui Hu and Junyi Chen
Foods 2026, 15(12), 2069; https://doi.org/10.3390/foods15122069 - 8 Jun 2026
Viewed by 429
Abstract
To investigate how spreading conditions affect green tea taste and aroma and to develop a generalizable prediction model from small data for process optimization, this study integrated SEM, non-targeted dual-omics, and TabPFN to systematically analyze Echa No. 10 spreading. A central composite design [...] Read more.
To investigate how spreading conditions affect green tea taste and aroma and to develop a generalizable prediction model from small data for process optimization, this study integrated SEM, non-targeted dual-omics, and TabPFN to systematically analyze Echa No. 10 spreading. A central composite design was used. Dehydration-induced mechanical stress altered cell membrane permeability, driving non-volatile taste compound transformation and volatile aroma release. Two chemical-sensory proxies, relative polyphenol-to-amino acid ratio (R-PAR) and floral intensity index (FII), were established using ultra-high performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). A prediction model was built with these indicators and TabPFN. Multi-objective optimization yielded optimum conditions: initial moisture 76.8%, temperature 26.2 °C, relative humidity 61.5%, air speed 0.85 m/s, achieving R-PAR 0.465 and FII 125.70. Compared with response surface methodology (RSM), partial least squares regression (PLSR), and support vector regression (SVR), TabPFN showed prediction R2 of 0.81 and 0.77, showing favorable applicability and predictive capability on small-sample data. This study validates TabPFN’s suitability for small-sample tea processing modeling, quantifies the mapping between spreading and key taste/aroma metabolism, and provides a methodological foundation for digital precision and intelligent optimization in green tea production. Full article
(This article belongs to the Special Issue Analysis of Tea Flavor and Functional Components)
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16 pages, 4019 KB  
Article
Association Between Sperm Metabolites and Field Fertility in Angus Bulls
by Samantha R. Roberts, Sarah E. Moorey, Adella B. Lonas, Emma A. Hessock, Blessing A. Abiodun, Shawn R. Campagna, F. Neal Schrick and Saulo Menegatti Zoca
Metabolites 2026, 16(5), 307; https://doi.org/10.3390/metabo16050307 - 30 Apr 2026
Viewed by 885
Abstract
Background/Objectives: Understanding the causes of bull subfertility and developing reliable diagnostic tools are critical to reducing economic losses caused by reproductive failure in beef cattle. Metabolomic analysis of sperm from bulls with diverging field fertility may provide insights on sperm metabolism that are [...] Read more.
Background/Objectives: Understanding the causes of bull subfertility and developing reliable diagnostic tools are critical to reducing economic losses caused by reproductive failure in beef cattle. Metabolomic analysis of sperm from bulls with diverging field fertility may provide insights on sperm metabolism that are associated with fertility. The objective was to determine metabolomic differences in sperm from bulls with differing field fertility. Methods: Angus bulls (n = 15) were classified based on a composite field fertility index (CFI). Frozen–thawed semen straws (n = 10 per bull) underwent a Percoll gradient sperm purification process. Metabolomic analysis was performed through ultra-high performance liquid chromatography coupled high resolution mass spectrometry at the University of Tennessee Biological and Small Molecule Mass Spectrometry Core. The general linear model (GLM) procedure of Statistical Analysis System (SAS) was used to evaluate linear and quadratic relationships between metabolites and CFI. Furthermore, the MIXED procedure was used to determine differences in metabolite abundance between the four highest and lowest fertility bulls. Significance was determined when p ≤ 0.05 and tendency was declared when p ≤ 0.10. Results: A total of 75 metabolites were detected. Quadratic relationships with fertility were observed for kynurenine, xanthine, and ophthalmate. Tricarballylic acid and creatinine showed a negative linear relationship with fertility. When differences in metabolite abundance were assessed between the four highest and lowest fertility bulls, N-acetylglutamate and N-acetylglutamine had greater abundance in low fertility bulls. Conclusions: Metabolites kynurenine, xanthine, ophthalmate, tricarballylic acid, and creatinine are potential fertility markers to identify subfertile bulls from a breeding population. These metabolites have promising future implications in the diagnosis and treatment of beef bull subfertility. Full article
(This article belongs to the Special Issue Metabolism and Reproduction in Animals)
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27 pages, 2894 KB  
Article
Shengmai San Ameliorates High-Glucose-Induced Calcium Homeostasis Imbalance via Improving Energy Metabolism in Neonatal Rat Cardiomyocytes
by Shixi Shang, Qu Zhai, Yuguo Huang, Junsong Yin, Jingju Wang and Xiaolu Shi
Pharmaceuticals 2026, 19(4), 601; https://doi.org/10.3390/ph19040601 - 8 Apr 2026
Viewed by 830
Abstract
Objective: This study aims to investigate the protective effect of Shengmai San (SMS) against high-glucose (HG)-induced injury in neonatal rat ventricular myocytes (NRVMs) and to elucidate the underlying pharmacological molecular mechanisms. We hypothesize that SMS ameliorates HG-induced calcium homeostasis imbalance in NRVMs by [...] Read more.
Objective: This study aims to investigate the protective effect of Shengmai San (SMS) against high-glucose (HG)-induced injury in neonatal rat ventricular myocytes (NRVMs) and to elucidate the underlying pharmacological molecular mechanisms. We hypothesize that SMS ameliorates HG-induced calcium homeostasis imbalance in NRVMs by improving mitochondrial energy metabolism disorder, and this protective effect is associated with the downregulation of oxidized and phosphorylated CaMKII expression to inhibit CaMKII signaling pathway overactivation. Herein, we verify this hypothesis by assessing mitochondrial function, calcium transients, sarcoplasmic reticulum (SR) calcium handling and CaMKII phosphorylation levels in NRVMs. Methods: First, ultra-high performance liquid chromatography–high resolution mass spectrometry was used to identify the chemical components of SMS to clarify its material basis. Primary NRVMs were then cultured under low-glucose (LG) or HG conditions, with 2% SMS-medicated serum (SMS-MS) as the experimental intervention, and NAC (ROS scavenger) and KN93 (CaMKII inhibitor) as positive controls. Following intervention, we sequentially detected key indicators corresponding to the proposed pathological pathway: intracellular reactive oxygen species (ROS) levels (oxidative stress), mitochondrial ROS, mitochondrial function indices including oxygen consumption rate (OCR) (energy metabolism), calcium transients and diastolic intracellular free calcium concentration (global calcium homeostasis), sarcoplasmic reticulum (SR) calcium leak (calcium handling disorder), and, finally, the phosphorylation, oxidation levels of CaMKII and RyR2 phosphorylation (Ser2814) (p-RyR2) (key regulatory pathway) via Western blot to systematically elucidate the mechanistic link between SMS intervention and HG-induced NRVM injury. Results: Quantitative analysis revealed that high-glucose (HG) induction significantly reduced calcium transient amplitude and prolonged the decay time constant (tau) in NRVMs at 72 h (p < 0.01 vs. LG), with these parameters normalizing by 120 h—an effect indicative of a compensatory adaptive response. The 2%SMS-MS markedly ameliorated HG-induced calcium transient abnormalities at 72 h (p < 0.01 vs. HG). Additionally, 2%SMS-MS significantly enhanced mitochondrial basal oxygen consumption rate, spare respiratory capacity, ATP production, and maximal respiration in HG-exposed NRVMs (p < 0.01 vs. HG). SMS also significantly reduced intracellular reactive oxygen species (ROS) levels (p < 0.01 vs. HG), mitochondrial ROS levels (p < 0.01 vs. HG), diastolic intracellular free calcium concentration (p < 0.01 vs. HG), and SR calcium leak (p < 0.05 vs. HG). Western blot analysis revealed that 2%SMS-MS intervention effectively downregulated the expression of oxidized CaMKII (Ox-CaMKII) (p < 0.01 vs. HG), phosphorylated CaMKII (p-CaMKII) (p < 0.01 vs. HG), and RyR2 phosphorylation (Ser2814) (p < 0.05 vs. HG), which may be the potential mechanism in maintaining calcium homeostasis in HG-induced NRVMs. Conclusions: This study suggests that SMS enhances mitochondrial energy metabolism and exerts a protective effect against high-glucose-induced calcium homeostasis imbalance in NRVMs, which supports our proposed hypothesis. Its potential mechanism indicates that the protective effects of SMS are associated with its ability to downregulate the expression of oxidized and phosphorylated CaMKII. These findings highlight SMS as a potential therapeutic candidate for alleviating HG-related myocardial injury and provide evidence for its application in the prevention of early diabetic cardiomyopathy. Full article
(This article belongs to the Section Pharmacology)
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20 pages, 8410 KB  
Article
Comprehensive Discovery and Characterization of Chemical Constituents in Huangqintang Decoction Using Off-Line Two-Dimensional Liquid Chromatography and High-Resolution Mass Spectrometry
by Yan Fang, Yi Nan, Xijie Tian, Junyu Zhang, Xiaojuan Chen, Juan Song, Haizhen Liang and Baiping Ma
Separations 2026, 13(4), 110; https://doi.org/10.3390/separations13040110 - 1 Apr 2026
Viewed by 547
Abstract
Traditional Chinese prescriptions are characterized by complex chemical constituents and wide variations in constituent content, which pose a substantial challenge to their comprehensive characterization. As a classic traditional Chinese prescription known for its heat-clearing and detoxifying properties, Huangqintang Decoction (HQD) is composed of [...] Read more.
Traditional Chinese prescriptions are characterized by complex chemical constituents and wide variations in constituent content, which pose a substantial challenge to their comprehensive characterization. As a classic traditional Chinese prescription known for its heat-clearing and detoxifying properties, Huangqintang Decoction (HQD) is composed of Scutellariae Radix, Paeoniae Radix Rubra, Glycyrrhizae Radix et Rhizoma, and Jujubae Fructus. In this study, we developed an off-line two-dimensional liquid chromatography that addressed the limitations of traditional analysis of unfractionated extracts, such as restricted peak capacity, which often obscured trace components. By coupling with ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS), this study successfully performed rapid identification or characterization of the complete chemical profile of HQD. Notably, beyond high-throughput identification, this approach leveraged characteristic fragment ions and reversed-phase chromatographic behaviors to differentiate some isomers of flavonoid glycosides and triterpenoid saponins, demonstrating its depth in structural identification. Flavonoid glycoside isomers were distinguished by diagnostic neutral losses, while flavanones and chalcones were characterized by retro-Diels–Alder (RDA) and β-rearrangement, respectively. Isomers of triterpenoid saponins were inferred from aglycone-specific pathways alongside RDA cleavages. Ultimately, a total of 192 compounds were identified, including 88 flavonoids, 80 triterpenoids, 7 monoterpene glycosides, 3 fatty acid amides, 3 phenylethanoid glycosides, 4 coumarins, 3 saccharides, 1 organic acid, and 3 others. This study demonstrated that the off-line two-dimensional liquid chromatography analysis strategy significantly enhanced chromatographic resolution and expanded the coverage of trace components. It presented an effective strategy for comprehensive compound identification in complex traditional Chinese medicine prescriptions. Full article
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23 pages, 1511 KB  
Article
Biochemical Characterization of Lipids, Proteins, and Polysaccharides from the Marine Diatom Phaeodactylum tricornutum Cultivated in Pilot-Scale Photobioreactors
by Arjun H. Banskota, Joseph P. M. Hui, Kaitlyn Blatt-Janmaat, Roumiana Stefanova, Alysson Jones, Sean M. Tibbetts and Patrick J. McGinn
Molecules 2026, 31(6), 1017; https://doi.org/10.3390/molecules31061017 - 18 Mar 2026
Viewed by 1207
Abstract
Phaeodactylum tricornutum was cultivated in a 1000 L photobioreactors using f/2 medium. The resulting algal biomass contained 24.5% lipids, 37.8% protein, 19.4% carbohydrates, and had a gross energy content of 19.8 MJ/kg. These components were sequentially extracted. The ultra-high performance liquid chromatography-high resolution [...] Read more.
Phaeodactylum tricornutum was cultivated in a 1000 L photobioreactors using f/2 medium. The resulting algal biomass contained 24.5% lipids, 37.8% protein, 19.4% carbohydrates, and had a gross energy content of 19.8 MJ/kg. These components were sequentially extracted. The ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) analysis of lipids revealed 35 triacylglycerols, a wide range of galactolipids and phospholipids including a novel sulfoquinovosyl diacylglycerol (SQDG), namely SQDG(C16:1/C24:0), characterized by mass fragmentation analysis. Additionally, three sulfoquinovosyl monoacylglycerols (SQMGs) with C14:0, C16:0, and C16:1 fatty acyl chain were detected in P. tricornutum for the first time. Fatty acid analysis further confirmed that P. tricornutum is an excellent source of ecosapentaenoic acid, which is predominantly present in triacylglycerol and glycolipid forms. CombiFlash chromatography allowed for the separation of monogalactosyldiacylglycerols, digalactosyldicylglycerols, SQDGs and phosphatidycholines, and their structure were confirmed by NMR spectral analysis. Fucoxanthin was the major carotenoid, and the study showed all essential amino acids required for humans and fish were present in it. A two-phase in vitro gastric/pancreatic digestibility assay showed high protein digestibility for both whole biomass (89%) and protein isolate (77%). Monosaccharide analysis showed that polysaccharides extracted by EtOH precipitation after alkaline extraction and by hot water extraction contained similar monomers with different relative intensities. Protein isolates and polysaccharides exhibited antioxidant properties. Full article
(This article belongs to the Special Issue Molecular Insights into Functional Lipids in Food Chemistry)
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18 pages, 1510 KB  
Article
Data Fusion Combining High-Resolution Mass Spectrometry and 1H-NMR Metabolomic Data with Gluten Protein Content to Assess the Impact of Agro-Sustainable Treatments on Durum Wheat
by Nicolò Riboni, Enmanuel Cruz Muñoz, Christina Muhs, Monica Mattarozzi, Marina Caldara, Sara Graziano, Christian Richter, Harald Schwalbe, Nelson Marmiroli, Davide Ballabio, Mariolina Gullì, Maria Careri and Federica Bianchi
Molecules 2026, 31(6), 922; https://doi.org/10.3390/molecules31060922 - 10 Mar 2026
Viewed by 814
Abstract
Sustainable food production systems based on the use of biofertilizers and soil improvers are proposed to mitigate agricultural-related environmental impacts and address the climate crisis. In particular, plant growth-promoting microbes (PGPM) and biochar (Char) have been reported to improve plant growth, soil quality, [...] Read more.
Sustainable food production systems based on the use of biofertilizers and soil improvers are proposed to mitigate agricultural-related environmental impacts and address the climate crisis. In particular, plant growth-promoting microbes (PGPM) and biochar (Char) have been reported to improve plant growth, soil quality, and crop yield; however, their effects on food quality remain debated. In this study, untargeted metabolomics based on ultra-high performance liquid chromatography–ion mobility–high-resolution mass spectrometry (UHPLC-IMS-HRMS) and proton nuclear magnetic resonance spectroscopy (1H-NMR) are proposed to achieve a comprehensive investigation of the effects of Char, PGPM and Char+PGPM on durum wheat. A total of 88 metabolites were annotated by UHPLC-IMS-HRMS, mainly belonging to carbohydrates, flavones, flavonoids, glycerophospholipids, and glycolipids, while 30 compounds were annotated by 1H-NMR, mostly amino acids and short-chain carboxylic acids. The two datasets were merged with the gluten protein content dataset by using low- and mid-level data fusion approaches, obtaining models that exhibit excellent classification performance. Integrated analysis highlighted that the combined Char+PGPM treatment induced metabolic changes across multiple chemical classes, including enrichment of flavonoids and lipids, and downregulation of carbohydrate metabolites, suggesting a redistribution of carbon resources and modulation of secondary metabolism with potential implications on wheat grain quality. Full article
(This article belongs to the Special Issue Application of Analytical Chemistry in Food Science)
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19 pages, 3414 KB  
Article
Optimization of Subcritical Water Extraction Process for Polyphenols from Cinchona calisaya and Their Activity Analysis
by Guangxin Li, Yujie Zhou, Dong Xie, Jingwen Zhang, Zhengshan Hu, Yuanping He, Lihua Zou, Ping Zhao, Yingjun Zhang, Xiaoqin Yang and Sengkew Wee
Molecules 2026, 31(4), 635; https://doi.org/10.3390/molecules31040635 - 12 Feb 2026
Viewed by 673
Abstract
This study expands research on Cinchona calisaya, which has traditionally focused on alkaloids, to address the insufficient comprehensive utilization of its resources. It is the first to explore the feasibility of extracting phenolic compounds from Cinchona calisaya using subcritical water extraction (SCWE) [...] Read more.
This study expands research on Cinchona calisaya, which has traditionally focused on alkaloids, to address the insufficient comprehensive utilization of its resources. It is the first to explore the feasibility of extracting phenolic compounds from Cinchona calisaya using subcritical water extraction (SCWE) technology. Combining single-factor experiments with Box–Behnken design-response surface methodology (BBD-RSM), the study optimized three key process parameters, namely extraction temperature, extraction time, and liquid-to-solid ratio, with total phenolic content (TPC) as the response variable. Optimal extraction conditions were 165 °C, 20 min, and a liquid-to-solid ratio of 70:1 mL/g. Under these conditions, the TPC values were 98.41 ± 1.06 mg/g for bark and 37.96 ± 1.18 mg/g for heartwood, significantly higher than those obtained by traditional hot water extraction (THWE). Ultra-high performance liquid chromatography-Q-orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) identified 1198 and 1156 metabolites in the bark and heartwood, respectively, with a higher content of phenolic compounds in the heartwood. The extracts showed strong inhibitory activity against Staphylococcus aureus, weak inhibitory activity against Escherichia coli at high concentrations, and no inhibitory effect on Candida albicans. This study provides a theoretical basis and technical support for the comprehensive utilization of Cinchona calisaya resources and the green development of natural antioxidants and antimicrobial agents. Full article
(This article belongs to the Special Issue Biological Evaluation of Plant Extracts)
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23 pages, 5712 KB  
Article
Ginseng-Derived Carbon Quantum Dots Enhance Systemic Exposure of Bioactive Ginsenosides and Amplify Energy Metabolism in Mice
by Huiqiang Liu, Xin Sun, Bo Yang, Chuan Lin, Xiwu Zhang, Hui Sun, Xiangcai Meng, Yufeng Bai, Tao Zhang, Guangli Yan, Ying Han and Xijun Wang
Pharmaceutics 2025, 17(11), 1485; https://doi.org/10.3390/pharmaceutics17111485 - 17 Nov 2025
Cited by 2 | Viewed by 1631
Abstract
Objective: To overcome the extremely low oral bioavailability of ginsenosides in traditional ginseng preparations, this study aimed to evaluate the efficacy of a novel ginseng-derived carbon quantum dots (G-CQDs) delivery system and to elucidate its core bioactive constituents and integrated mechanisms of action. [...] Read more.
Objective: To overcome the extremely low oral bioavailability of ginsenosides in traditional ginseng preparations, this study aimed to evaluate the efficacy of a novel ginseng-derived carbon quantum dots (G-CQDs) delivery system and to elucidate its core bioactive constituents and integrated mechanisms of action. Methods: G-CQDs were prepared from ginseng roots via ultrahigh-speed nitrogen jet pulverization combined with far-infrared pulse-assisted hydrothermal carbonization. Their physicochemical properties were characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, and fluorescence spectroscopy. The in vivo effects of G-CQDs versus traditional ginseng aqueous extract (G-AE) were compared in C57BL/6 mice (n = 12/group) using the PRO-MRRM-8 Comprehensive Laboratory Animal Monitoring System for real-time, non-invasive phenotyping of energy metabolism parameters (respiratory quotient, heat production, and oxygen consumption). Systemic exposure to ginseng bioactives was profiled using UHPLC-Q/Orbitrap/LTQ high-resolution mass spectrometry, followed by bivariate correlation analysis to identify key bioactive components linked to efficacy. Results: Compared with G-AE, G-CQDs significantly enhanced whole-body energy metabolism—respiratory quotient +2.8%, heat production +6.7%, and locomotor activity +22.9% (p < 0.05). A total of 110 in vitro constituents, 35 blood prototypes, and 29 metabolites were identified. Correlation analysis revealed eight core bioactive clusters linked to the metabolic benefits; all showed higher systemic exposure with G-CQDs (range +9.2% to +265.8%), notably ginsenoside Re +69.6%, cinnamic acid + O + SO3 +157.4%, and linolenic acid–GSH conjugate +265.8%. Conclusions: Carbon quantum dot technology significantly enhances the systemic exposure of ginseng bioactivities by improving solubility and enhancing gastrointestinal absorption, providing a molecular basis for its superior efficacy in regulating energy metabolism compared to conventional extracts. This study establishes a novel framework for developing high-value, bioavailability-enhanced nano-preparations from traditional medicines. Full article
(This article belongs to the Section Nanomedicine and Nanotechnology)
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17 pages, 1905 KB  
Article
Lipidomic Screening of Marine Diatoms Reveals Release of Dissolved Oxylipins Associated with Silicon Limitation and Growth Phase
by Imanol Ulloa, Jiwoon Hwang, Matthew D. Johnson and Bethanie R. Edwards
Mar. Drugs 2025, 23(11), 424; https://doi.org/10.3390/md23110424 - 31 Oct 2025
Cited by 1 | Viewed by 1490
Abstract
Marine diatoms are an important group of phytoplankton that can shape marine ecosystems and global carbon cycling. When stressed, either physiologically or by grazing, diatoms release oxidized, lipid-derived signals known as oxylipins. Diatom-derived oxylipins are proposed to serve as defense and signaling chemicals [...] Read more.
Marine diatoms are an important group of phytoplankton that can shape marine ecosystems and global carbon cycling. When stressed, either physiologically or by grazing, diatoms release oxidized, lipid-derived signals known as oxylipins. Diatom-derived oxylipins are proposed to serve as defense and signaling chemicals that affect multiple components of marine ecosystems. Therefore, to elucidate the diversity of diatom-derived oxylipins produced during stress, we profiled the spectrum of dissolved lipids of five diatom species in culture under silicon limitation and across growth phases using ultra-high performance liquid chromatography coupled with high-resolution accurate mass spectrometry. In this study, we present evidence that physiological changes associated with Si-limitation elicit the extracellular release of linear oxygenated fatty acids (LOFAs) across five diatom species. For diatoms like Skeletonema japonicum and Pseudo-nitzschia multiseries, silicon limitation induced a distinct lipidomic signature driven by oxylipins known to be allelopathic. While their lipoxygenases were found to be different, S. japonicum and P. multiseries had the most similar dissolved lipidomes, suggesting alternative controls on oxylipin biosynthesis. Consequently, elevated oxylipin concentrations with silicon stress, estimated up to 5.91 µM, pose implications for diatoms at sea, potentially affecting ecosystems and biogeochemistry. Full article
(This article belongs to the Special Issue Marine Algal Chemical Ecology 2024)
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16 pages, 2086 KB  
Article
High-Coverage Profiling of Hydroxyl and Amino Compounds in Sauce-Flavor Baijiu Using Bromine Isotope Labeling and Ultra-High Performance Liquid Chromatography–High-Resolution Mass Spectrometry
by Zixuan Wang, Youlan Sun, Tiantian Chen, Lili Jiang, Yuhao Shang, Xiaolong You, Feng Hu, Di Yu, Xinyu Liu, Bo Wan, Chunxiu Hu and Guowang Xu
Metabolites 2025, 15(7), 464; https://doi.org/10.3390/metabo15070464 - 9 Jul 2025
Cited by 3 | Viewed by 1356
Abstract
Background: Hydroxyl and amino compounds play a significant role in defining the flavor and quality of sauce-flavor Baijiu, yet their comprehensive analysis remains challenging due to limitations in detection sensitivity. In this study, we developed a novel bromine isotope labeling approach combined [...] Read more.
Background: Hydroxyl and amino compounds play a significant role in defining the flavor and quality of sauce-flavor Baijiu, yet their comprehensive analysis remains challenging due to limitations in detection sensitivity. In this study, we developed a novel bromine isotope labeling approach combined with ultra-high performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS) to achieve high-coverage profiling of these compounds in sauce-flavor Baijiu. Methods: The method employs 5-bromonicotinoyl chloride (BrNC) for rapid (30 s) and mild (room temperature) labeling of hydroxyl and amino functional groups, utilizing bromine’s natural isotopic pattern (Δm/z = 1.998 Da) for efficient screening. Annotation was performed hierarchically at five confidence levels by integrating retention time, accurate mass, and MS/MS spectra. Results: A total of 309 hydroxyl and amino compounds, including flavor substances (e.g., tyrosol and phenethyl alcohol) and bioactive compounds (e.g., 3-phenyllactic acid), were identified in sauce-flavor Baijiu. The method exhibited excellent analytical performance, with wide linearity (1–4 orders of magnitude), precision (RSD < 18.3%), and stability (RSD < 15% over 48 h). When applied to sauce-flavor Baijiu samples of different grades, distinct compositional patterns were observed: premium-grade products showed greater metabolite diversity and higher contents of bioactive compounds, whereas lower-grade samples exhibited elevated concentrations of acidic flavor compounds. Conclusions: These results demonstrate that the established method is efficient for the comprehensive analysis of hydroxyl and amino compounds in complex food matrices. The findings provide valuable insights for quality control and flavor modulation in sauce-flavor Baijiu production. Full article
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18 pages, 405 KB  
Article
Validated UHPLC Methods for Melatonin Quantification Reveal Regulatory Violations in EU Online Dietary Supplements Commerce
by Celine Vanhee, Cloë Degrève, Niels Boschmans, Yasmina Naïmi, Michael Canfyn, Eric Deconinck and Marie Willocx
Molecules 2025, 30(12), 2647; https://doi.org/10.3390/molecules30122647 - 19 Jun 2025
Cited by 4 | Viewed by 10702
Abstract
The global sleep aids market has grown significantly due to rising stress and increased awareness of sleep’s importance. Melatonin, available in the EU as a prescription or over-the-counter medicine, depending on the country, is also permitted in dietary supplements with country-specific limits. Recent [...] Read more.
The global sleep aids market has grown significantly due to rising stress and increased awareness of sleep’s importance. Melatonin, available in the EU as a prescription or over-the-counter medicine, depending on the country, is also permitted in dietary supplements with country-specific limits. Recent reports indicate concerning levels of excessive melatonin in EU dietary supplements, necessitating accurate quantification methods. We developed and validated, by applying accuracy profiles, ISO17025-compliant, rapid ultra-high performance liquid chromatography (UHPLC) methodologies coupled with either diode array detection (DAD) or high-resolution accurate mass spectrometry (HRAM MS). The cost-effective UHPLC-DAD method is suitable for medicines and most dietary supplements, except those more complex herbal matrices containing passionflower, hop, hemp, lime tree or lavender or their extracts, where UHPLC-HRAM MS is recommended due to selectivity issues of the DAD methodology. To demonstrate the applicability, we analyzed 50 dietary supplements claiming to contain melatonin—25 from legal supply chains and 25 from suspicious sources claiming therapeutic melatonin content. Our findings confirmed previous reports of high melatonin content in online products, especially when purchased through rogue internet pharmacies. Moreover, 12% of legal supply chain samples violated current legislation through unauthorized health claims or contained at least triple the melatonin amount permitted in Belgium. This research provides reliable analytical methods for regulatory bodies and confirms the circulation of non-compliant melatonin-containing dietary supplements in the EU market, even in the legal supply chain. Full article
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15 pages, 1936 KB  
Article
Studying the Formation of Fullerenes During Catagenesis
by Jens Dreschmann and Wolfgang Schrader
Molecules 2025, 30(12), 2516; https://doi.org/10.3390/molecules30122516 - 9 Jun 2025
Viewed by 1329
Abstract
The formation of polycyclic aromatic hydrocarbons (PAHs) during catagenesis does not exclusively lead to planar structures. The inclusion of five-ring elements increases the curvature of PAHs and yields bent molecules. These bowl-like configurations may end in the formation of spherical carbon allotropes as [...] Read more.
The formation of polycyclic aromatic hydrocarbons (PAHs) during catagenesis does not exclusively lead to planar structures. The inclusion of five-ring elements increases the curvature of PAHs and yields bent molecules. These bowl-like configurations may end in the formation of spherical carbon allotropes as fullerenes or nanotubes, as recently shown. The presence of fullerenes in crude oil raises the question of why the reaction is feasible under catagenic conditions although the laboratory synthesis of fullerenes commonly requires high-energy environments. This study focuses on the feasibility of the simulation of catagenesis under laboratory conditions and the question of which building blocks may lead to spherical structures. Possible educts, reaction mechanisms, and conditions such as temperature are discussed and related to experimental outcomes. For the simulation under laboratory conditions, a light gas condensate was fractionated by distillation in order to reduce the number of compounds per fraction and make them distinguishable. The characterization of the resulting fractions was performed through GC-MS and GC-FID measurements before heat application in a closed reactor. High-resolution mass spectrometry (HRMS) measurements of the products indicated PAH growth and, more importantly, the formation of fullerenes. Interestingly, the characterized fullerenes mostly comprised the range of non-IPR (isolated pentagon rule) fullerenes. Full article
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20 pages, 5401 KB  
Article
Detection of Cereibacter azotoformans-YS02 as a Novel Source of Coenzyme Q10 and Its Metabolic Analysis
by Meijie Song, Qianqian Xu, Rifat Nowshin Raka, Chunhua Yin, Xiaolu Liu and Hai Yan
Antioxidants 2025, 14(4), 429; https://doi.org/10.3390/antiox14040429 - 1 Apr 2025
Viewed by 1893
Abstract
Coenzyme Q10 (CoQ10), a high-value-added nutraceutical antioxidant, exhibits an excellent ability to prevent cardiovascular disease. Here, a novel Cereibacter azotoformans strain, designated YS02, was isolated for its ability to produce CoQ10 and genetically characterized by whole genome sequencing (WGS). The CoQ10 biosynthesis and [...] Read more.
Coenzyme Q10 (CoQ10), a high-value-added nutraceutical antioxidant, exhibits an excellent ability to prevent cardiovascular disease. Here, a novel Cereibacter azotoformans strain, designated YS02, was isolated for its ability to produce CoQ10 and genetically characterized by whole genome sequencing (WGS). The CoQ10 biosynthesis and metabolism differences of YS02 under various culture conditions were also systematically investigated. Phylogenetic analysis based on 16 S rRNA genes, along with taxonomic verification using average nucleotide identity (ANI) analysis, confirmed its classification as C. azotoformans. Enzymatic genes dxs, dxr, idi, ubiA, and ubiG were annotated in YS02, which are critical genetic hallmarks for CoQ10 biosynthesis. Under aerobic–dark cultivation, YS02 grows well, and CoQ10 production can reach 201 mg/kg. A total of 542 small-molecule metabolites were identified from YS02 in aerobic–dark and anaerobic–light cultivation via ultra-high performance liquid chromatography–coupled quadrupole orbitrap high-resolution mass spectrometry (UPLC-Q-Exactive Orbitrap MS). Additionally, 40 differential metabolites were screened through multivariate statistical analysis. Metabolic pathway analysis revealed that the biosynthesis of phenylalanine, tyrosine, and tryptophan might be latent factors influencing CoQ10 production discrepancies within YS02 under both cultural modes. These findings represent new insights into the metabolic mechanism of YS02 and underscore its potential as an alternative strain source for industrial CoQ10 production, enriching the existing resources. Full article
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15 pages, 1869 KB  
Article
Molecular Composition of Stream Dissolved Organic Matter in Cool-Temperate Forest Headwaters with Landslides, Northern Japan
by Jun’ichiro Ide, Kenta Hara, Yohei Arata, Izuki Endo, Mizue Ohashi, Hiroshi Nishimura and Takashi Gomi
Hydrology 2025, 12(3), 63; https://doi.org/10.3390/hydrology12030063 - 19 Mar 2025
Viewed by 2070
Abstract
Vegetation and subsequent ecosystem services can recover over time in forest headwaters devastated by massive disasters. However, in cold regions, their recovery rates are typically slow and often imperceptible, which makes it difficult to evaluate how much ecosystem services have recovered. This study [...] Read more.
Vegetation and subsequent ecosystem services can recover over time in forest headwaters devastated by massive disasters. However, in cold regions, their recovery rates are typically slow and often imperceptible, which makes it difficult to evaluate how much ecosystem services have recovered. This study targeted dissolved organic matter (DOM), which plays a central role in biogeochemical processes in forest ecosystems, and aimed to examine whether vegetation conditions affect the quality of stream DOM from cool-temperate forest headwaters in northern Japan. To achieve this, hydrological observations and stream water sampling were conducted monthly from May to December 2021 in three small forest catchments with different landslide coverage. Dissolved organic carbon (DOC) concentration in stream water was measured, and the molecular composition of DOM was analyzed using ultrahigh-resolution mass spectrometry and compared among the three catchments. The peak-intensity-weighted average aromaticity index (AIwa) increased with DOC concentration. We found that AIwa was the highest in the undisturbed catchment, followed by the catchments with landslide coverages of 16% and 52% at a given DOC level. These results indicate that the quality of DOM could dramatically change depending not only on DOC concentration but also on vegetation disturbance in cool-temperate forest headwaters. Full article
(This article belongs to the Section Surface Waters and Groundwaters)
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Article
Exploring the Molecular Composition of Dissolved Organic Matter and Its Connection to Microbial Communities in Industrial-Scale Anaerobic Digestion of Chicken Manure
by Juan Hu, Yurui Zeng, Aibin Hu and Xiaofeng Wang
Toxics 2025, 13(1), 49; https://doi.org/10.3390/toxics13010049 - 10 Jan 2025
Cited by 5 | Viewed by 2889
Abstract
Anaerobic digestion (AD) technology offers significant advantages in addressing environmental issues arising from the intensification of livestock production since it enables waste reduction and energy recovery. However, the molecular composition of dissolved organic matter (DOM) and its linkages to microbial biodiversity during the [...] Read more.
Anaerobic digestion (AD) technology offers significant advantages in addressing environmental issues arising from the intensification of livestock production since it enables waste reduction and energy recovery. However, the molecular composition of dissolved organic matter (DOM) and its linkages to microbial biodiversity during the industrial-scale AD process of chicken manure (CM) remains unclear. In this study, the chemical structure of CM digestate-derived DOM was characterized by using multi-spectroscopic techniques and ultrahigh-resolution mass spectrometry, and the microbial composition was detected by using 16S rRNA gene sequencing. The results revealed that the DOM contained abundant free amino acids and protein-like compounds but fewer humic-like substances, identified as lignin/carboxylate-rich alicyclic molecules, lipids, and proteins/aliphatic compounds featuring enriched S5–6O1 and N1–5OX fragments. In addition, the 16S rRNA results revealed microorganisms that were centered on metabolic function in the production of volatile fatty acids, H2S/CH4, and the hydrolysis reaction in the AD process. Free amino acids and protein-like compounds were mainly associated with hydrolysis reactions and H2S production functional microorganisms. Lignin/carboxylate-rich alicyclic molecules were linked to microorganisms possessing hydrolysis reactions and, indirectly, CH4 production. This study elucidates the linkage with the microbial and molecular composition of DOM, establishing a theoretical foundation for employing AD in the disposal of CM. Full article
(This article belongs to the Special Issue Biomass Conversion and Organic Waste Utilization in Wastewater)
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