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Keywords = nuclear magnetic resonance spectroscopy

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13 pages, 277 KB  
Article
Integrated Serum and Urinary Metabolomics Reveal Distinct Signatures of Kidney Graft Function—A Single-Center Cohort Study
by Cezar Valeriu Băluță, Lucian Siriteanu, Ionuț Nistor, Luminița Voroneanu, Simona Mihaela Hogas, Andreea Covic, Călin Namolovan, Raluca Erika Irimie Băluță, Radu Gavril, Calin Deleanu, Alina Nicolescu, Mehmet Kanbay and Adrian Covic
Biomedicines 2026, 14(8), 1875; https://doi.org/10.3390/biomedicines14081875 - 21 Aug 2026
Viewed by 320
Abstract
Background/Objectives: Kidney transplantation remains the gold standard treatment of end-stage kidney disease; however, its recipients exhibit mixed clinical trajectories, with variable renal function and proteinuria evolution over time. Currently used methods to screen these changes are associated with possible adverse effects and [...] Read more.
Background/Objectives: Kidney transplantation remains the gold standard treatment of end-stage kidney disease; however, its recipients exhibit mixed clinical trajectories, with variable renal function and proteinuria evolution over time. Currently used methods to screen these changes are associated with possible adverse effects and limitations. Methods: In this single-center cohort study, 174 adult kidney transplant recipients were enrolled between January 2024 and January 2025 and followed for 12 months. Patients underwent serum and urinary metabolomic profiling using nuclear magnetic resonance (NMR) spectroscopy. Furthermore, clinical and biological data were collected, allowing for assessment of changes in renal function and proteinuria, with patient stratification based on outcome trends. Results: Serum metabolomic profiles were linked to renal outcomes. For ΔeGFR, valine differed between patients with positive and negative trajectories, while GlycA, GlycB and Glyc/SPC were associated with ΔeGFR in adjusted models. For Δproteinuria, GlycA, VLDL particles and triglycerides showed correlations, while glucose differed between patients with improving and worsening proteinuria. In adjusted models, isoleucine, alanine, GlycA and Glyc/SPC were associated with Δproteinuria. Urinary metabolomic profiles showed fewer associations. Dimethylamine and urinary creatinine were associated with ΔeGFR in adjusted models, while acetic acid differed between proteinuria groups. No urinary metabolite was associated with Δproteinuria after adjustment. Conclusions: Overall, metabolomic changes were connected with renal outcomes in kidney transplant patients, with distinct but partially overlapping patterns for ΔGFR and Δproteinuria. Serum findings were more consistent, while urinary associations were more limited. Further longitudinal and externally validated studies are required to confirm these observations and explore the potential of this metabolomic approach in the search for novel biomarkers. Full article
16 pages, 6913 KB  
Article
Alkoxyl Derivatives of 7-Hydroxyflavone: Synthesis, Physicochemical Properties, Antioxidant, and Antihyperglycemic Activities
by Patryk Mruczek, Andrzej Grudzień and Monika Kadela-Tomanek
Appl. Sci. 2026, 16(16), 8331; https://doi.org/10.3390/app16168331 - 21 Aug 2026
Viewed by 216
Abstract
Flavones are natural substances widely distributed in fruits and vegetable. Their compounds are characterized by a broad spectrum of activities, including antioxidant activity. Their most interesting biological effect, however, is antihyperglycemic activity, mediated by the inhibition of α-glucosidase. A series of 7-hydroxyflavone derivatives [...] Read more.
Flavones are natural substances widely distributed in fruits and vegetable. Their compounds are characterized by a broad spectrum of activities, including antioxidant activity. Their most interesting biological effect, however, is antihyperglycemic activity, mediated by the inhibition of α-glucosidase. A series of 7-hydroxyflavone derivatives was synthesized and comprehensively characterized using nuclear resonance magnetic spectroscopy. The biological potential of the synthesized derivatives was assessed through antioxidant (DPPH) and α-glucosidase inhibitory assays. The physicochemical and pharmacokinetic properties were analyzed using in silico methods. Finally, molecular docking studies were performed to elucidate the binding mode of compounds within the catalytic site of α-glucosidase. Full article
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18 pages, 2775 KB  
Article
Ultrasonic-Assisted Heterogeneous Fenton-like (UHEF) Pretreatment of Eucalyptus Sawdust for Enhanced Enzymatic Hydrolysis
by Han Zhang, Cuixian Peng, Xiaoguo Wang, Ping Li, Wei Tan and Shujie Wang
Molecules 2026, 31(16), 2926; https://doi.org/10.3390/molecules31162926 - 21 Aug 2026
Viewed by 195
Abstract
Ultrasonic-assisted heterogeneous Fenton-like (UHEF) pretreatment is an emerging strategy that overcomes the limitations of traditional homogeneous Fenton systems while enhancing the efficiency of lignocellulosic biomass processing. In this study, we constructed a UHEF system employing iron-loaded zeolite as a heterogeneous catalyst to pretreat [...] Read more.
Ultrasonic-assisted heterogeneous Fenton-like (UHEF) pretreatment is an emerging strategy that overcomes the limitations of traditional homogeneous Fenton systems while enhancing the efficiency of lignocellulosic biomass processing. In this study, we constructed a UHEF system employing iron-loaded zeolite as a heterogeneous catalyst to pretreat eucalyptus sawdust (ES). Process conditions were optimized using response surface methodology (RSM) with a central composite design (CCD), yielding a maximum reducing sugar production of 441.45 mg/g. We systematically investigated the mechanism by which UHEF pretreatment enhances the enzymatic hydrolysis of ES through compositional analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), cross-polarization magic-angle spinning carbon-13 nuclear magnetic resonance (CP/MAS 13C NMR), and scanning electron microscopy (SEM). Additionally, recovery and recycling experiments were conducted to evaluate the reusability of the iron-loaded zeolite. XRD, XPS, and ICP-OES were further used to verify the crystalline structure, surface Fe chemical states, and Fe loading of the catalyst, and Fe leaching was quantified for each reuse cycle. The results demonstrated that UHEF pretreatment effectively removed lignin and hemicellulose from ES, disrupted the cellulose crystalline structure, and generated numerous grooves on the substrate surface. These modifications increased the effective adsorption of cellulase and enhanced reducing sugar production to 4.32 times that of raw eucalyptus sawdust (RES). Although the recycling experiments indicated that the stability of the iron-loaded zeolite requires further improvement, the catalyst retained a certain degree of reusability over four consecutive cycles. These findings demonstrate that UHEF pretreatment is a promising approach with broad application prospects in lignocellulosic biorefinery, consistent with recent advances in advanced oxidation processes for biomass valorization. Full article
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22 pages, 664 KB  
Article
Influence of Methoxy Substitution Pattern on Cascade Biotransformation of 4′-Hydroxychalcones by Entomopathogenic Fungi
by Paweł Chlipała, Julia Bienia, Tomasz Tronina, Jerzy Ł. Wiśniewski and Tomasz Janeczko
Int. J. Mol. Sci. 2026, 27(16), 7463; https://doi.org/10.3390/ijms27167463 - 20 Aug 2026
Viewed by 186
Abstract
4′-Hydroxymethoxychalcones represent structurally diverse chalcone derivatives that are attractive substrates for microbial functionalization; however, the impact of methoxy substitution position on their cascade biotransformation by fungi remains poorly understood. In this study, three regioisomeric 4′-hydroxymethoxychalcones, featuring ortho-, meta-, or para-methoxy [...] Read more.
4′-Hydroxymethoxychalcones represent structurally diverse chalcone derivatives that are attractive substrates for microbial functionalization; however, the impact of methoxy substitution position on their cascade biotransformation by fungi remains poorly understood. In this study, three regioisomeric 4′-hydroxymethoxychalcones, featuring ortho-, meta-, or para-methoxy groups on ring B, were transformed using eight entomopathogenic fungal strains belonging to the genera Beauveria, Isaria, and Metarhizium. Metabolic profiles were monitored over a 10-day period using ultra-high-performance liquid chromatography coupled with diode-array detection (UHPLC-DAD), and the structures of the major products were elucidated primarily by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and further supported by high-resolution electrospray ionization quadrupole time-of-flight mass spectrometry (HR-ESI-QTOF-MS). The investigated microorganisms catalyzed multistep transformations encompassing the reduction of the α,β-unsaturated carbonyl system, methylglucosylation, O-demethylation, and the formation of secondary polar metabolites. Although ene-reduction constituted the predominant initial reaction for all substrates, the relative distribution of subsequent metabolites varied depending on both the fungal strain and, to a lesser extent, the position of the methoxy group. The ortho-methoxy derivative exhibited the highest propensity for O-demethylation; the meta-substituted substrate generated the most heterogeneous secondary metabolite profiles, whereas the para-methoxy analogue showed the most consistent accumulation of methylglucosylated dihydrochalcones. These findings indicate that methoxy substitution position does not alter the common core biotransformation pathway, but can modulate the relative efficiency of individual steps and the extent of secondary metabolism. Full article
(This article belongs to the Special Issue Dietary Polyphenols and Human Health)
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25 pages, 1315 KB  
Article
NMR Profiling of European Oak Honeydew Honeys: Saccharide Diversity and Geographical Differentiation
by Dessislava Gerginova, María del Carmen Seijo Coello, Nikola Jovanović, Marco Ciulu and Svetlana Simova
Molecules 2026, 31(16), 2913; https://doi.org/10.3390/molecules31162913 - 20 Aug 2026
Viewed by 212
Abstract
Although European oak honeydew honeys have a similar botanical origin, it is unclear if their chemical composition reflects their geographical origin. Sixty samples from Bulgaria, Germany, Greece, Italy, North Macedonia, Romania, Serbia, and Spain were analyzed using semiquantitative 13C nuclear magnetic resonance [...] Read more.
Although European oak honeydew honeys have a similar botanical origin, it is unclear if their chemical composition reflects their geographical origin. Sixty samples from Bulgaria, Germany, Greece, Italy, North Macedonia, Romania, Serbia, and Spain were analyzed using semiquantitative 13C nuclear magnetic resonance (NMR) spectroscopy. The protected designation of origin (PDO) Strandzha honey was compared to honey from other regions in Bulgaria. The profiles included 25 identified constituents, 21 saccharides, and 16 reproducible unidentified signals. Statistical analysis differentiated country groups through combinations of variables rather than a single marker. A decision tree based on nigerose, fructose, melezitose, panose, sucrose, and one unidentified signal summarized the main differences among the countries. Strandzha honeys exhibited a unique regional profile characterized by higher glucose levels and lower concentrations of several minor saccharides and unidentified signals. Two coordinated saccharide networks revealed that minor sugars fluctuate in linked groups rather than independently. This pattern has not been previously described in European honey. Conventional honeydew-associated indicators varied across the dataset. However, 1-kestose was present in all samples. Nevertheless, its specificity to oak honeydew origin remains unresolved. While extended 13C NMR profiling may support geographical characterization, independent validation is required before it can be used for authentication. Full article
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16 pages, 6413 KB  
Article
Fluorine-Modulated Reactivity Enables One-Pot Kinetic Sequence Programming of Block Copolyesters
by Chun-Yao Ke, Ryota Suzuki, Takuya Yamamoto, Takuya Isono, Guey-Sheng Liou and Toshifumi Satoh
Polymers 2026, 18(16), 1977; https://doi.org/10.3390/polym18161977 - 14 Aug 2026
Viewed by 302
Abstract
Monomer sequence strongly influences copolymer properties, but direct block formation from a monomer mixture requires a large reactivity contrast. Here, fluorination was used to regulate anhydride reactivity in the cesium pivalate-catalyzed ring-opening alternating copolymerization (ROAC) of tetrafluorophthalic anhydride (FPA), phthalic anhydride (PA), and [...] Read more.
Monomer sequence strongly influences copolymer properties, but direct block formation from a monomer mixture requires a large reactivity contrast. Here, fluorination was used to regulate anhydride reactivity in the cesium pivalate-catalyzed ring-opening alternating copolymerization (ROAC) of tetrafluorophthalic anhydride (FPA), phthalic anhydride (PA), and 3-perfluorohexyl-1,2-epoxypropane (PFE). Time-resolved nuclear magnetic resonance (NMR) spectroscopy showed that FPA reached >99% conversion before detectable PA incorporation. With 1,4-benzenedimethanol as a bidirectional initiator, this sequential consumption generated a central poly(FPA-alt-PFE) segment followed by poly(PA-alt-PFE) growth from both chain ends. Molar mass evolution, end-group analysis, and diffusion-ordered spectroscopy (DOSY) NMR collectively supported covalent block formation. Sequential incorporation was retained across three different FPA:PA feed ratios, and Beckingham–Sanoja–Lynd analysis yielded large and reciprocal effective reactivity-ratio descriptors (rFPA8.38.6×102 and rPA1.2×103), consistent with the experimentally observed real-block regime. Matched model reactions further indicated faster FPA ring-opening and higher observed epoxide-opening reactivity in a fluorinated aromatic carboxylate model system. These results demonstrate that H-to-F substitution can provide the kinetic bias required to program block copolyester sequence within a single ROAC platform. Full article
(This article belongs to the Section Polymer Chemistry)
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20 pages, 3339 KB  
Article
Vineyard Age Mediates Soil Organic Phosphorus Turnover via Phosphodiesterase, Acid Phosphomonoesterase and phoC Gene
by Guohui Wu, Zhubing Shao, Xue Wang, Shuo Fang, Lei Yan, Xiaotong Guo, Chunyan Yu and Hongxia Zhang
Agronomy 2026, 16(16), 1557; https://doi.org/10.3390/agronomy16161557 - 14 Aug 2026
Viewed by 263
Abstract
Organic phosphorus (OP) transformation in perennial orchard soils is strongly regulated by planting duration. However, the pathways of soil OP turnover in the orchards with different planting years remain largely unknown. This study was conducted in Penglai District, Shandong Province, China, characterized by [...] Read more.
Organic phosphorus (OP) transformation in perennial orchard soils is strongly regulated by planting duration. However, the pathways of soil OP turnover in the orchards with different planting years remain largely unknown. This study was conducted in Penglai District, Shandong Province, China, characterized by a warm-temperate continental monsoon climate and brown sandy loam soil. Soil samples were collected from the 0–20 cm layer of vineyards established for 0.5, 4, 16, and 22 years (Y0.5, Y4, Y16, and Y22, respectively). Soil P pools, OP forms determined by solution 31P nuclear magnetic resonance spectroscopy, acid and alkaline phosphomonoesterase (ACP and ALP), phosphodiesterase (PDE) activities, and the diversity and composition of phoC- and phoD-harboring bacterial communities were analyzed. Differences among vineyard ages were assessed using one-way ANOVA, while principal coordinate analysis, canonical correlation analysis, and structural equation modeling were employed to evaluate microbial community variation and the relationships among soil properties, functional bacterial communities, phosphatase activities, and OP forms. We observed that compared with that in Y0.5, total P content in Y4 was significantly lower, whereas available P (AP) content in Y16, and OP content in both Y16 and Y22, were significantly higher. The contents of orthophosphate, myo-inositol hexakisphosphate (myo-IHP), scyllo-IHP, choline phosphate and corrected monoester (cMonoester) in Y16 and Y22 were significantly higher than that in Y0.5. Soil ACP activity in Y16 was significantly higher than that in Y4, but ALP and PDE activities in Y16 were significantly lower than those in other planting years. The phoC- and phoD-harboring community composition in Y16 was significantly altered, with phoC- and phoD-harboring community α-diversity remarkably increased and decreased, respectively. The phoC- and phoD-harboring community composition was driven by soil pH, AP and cMonoester, with phoD-harboring community composition predicted by the soil C:P ratio. Soil OP transformation is mainly regulated by the activity of PDE and ACP, and the diversity and composition of phoC-harboring communities, in orchards with different planting years. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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22 pages, 7776 KB  
Article
Comparative Characterisation and In Vitro Metabolic Bioactivities of Fucoidan-Rich Extracts from Three South African Brown Macroalgae
by Coleen E. Grobler, Blessing Mabate, Justin B. Safari and Brett I. Pletschke
Molecules 2026, 31(16), 2823; https://doi.org/10.3390/molecules31162823 - 13 Aug 2026
Viewed by 249
Abstract
Fucoidans are sulphated polysaccharides from brown macroalgae that have attracted considerable interest due to their diverse biological activities and potential applications in metabolic health. In this study, fucoidan-rich extracts were obtained from three South African brown macroalgal species, Ecklonia maxima, Ecklonia radiata [...] Read more.
Fucoidans are sulphated polysaccharides from brown macroalgae that have attracted considerable interest due to their diverse biological activities and potential applications in metabolic health. In this study, fucoidan-rich extracts were obtained from three South African brown macroalgal species, Ecklonia maxima, Ecklonia radiata, and Sargassum incisifolium, and comparatively characterised using biochemical and physicochemical analyses. The extracts were evaluated for carbohydrate, sulphate, L-fucose, protein, polyphenol, and uronic acid contents, while molecular weight distribution, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and proton Nuclear Magnetic Resonance (1H NMR) spectroscopy were used to investigate structural characteristics. All extracts displayed features characteristic of fucoidans, including sulphated fucose-containing polysaccharides. Notable species-dependent differences were observed, with S. incisifolium exhibiting the highest sulphate (~24%) and polyphenol (~6.76%) contents, stronger sulphate-associated FTIR signals, greater molecular weight heterogeneity, and enhanced thermal stability. The fucoidan-rich extracts exhibited concentration-dependent pancreatic lipase and α-glucosidase inhibitory activities, together with DPPH radical-scavenging activity. At 1.0 mg/mL, S. incisifolium demonstrated approximately 66% DPPH radical scavenging and 49% pancreatic lipase inhibition. S. incisifolium and E. radiata exhibited strong α-glucosidase inhibition, with IC50 values of ~29 and ~46 µg/mL, respectively, compared to ~354 µg/mL for acarbose. The findings highlight South African brown macroalgae as promising sources of fucoidans and contribute to understanding the relationships among fucoidan composition, structure, and bioactivity. Full article
(This article belongs to the Special Issue Exclusive Feature Papers in Natural Products Chemistry, 3rd Edition)
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27 pages, 13533 KB  
Review
Characterization of Solid Electrolyte Interphases on Carbon-Based Negative Electrodes for Lithium-Ion Batteries: Methods, Artifacts, and Correlative Workflows
by Soon-Ki Jeong
Batteries 2026, 12(8), 302; https://doi.org/10.3390/batteries12080302 - 13 Aug 2026
Viewed by 251
Abstract
Solid electrolyte interphase (SEI) characterization is needed to interpret the performance, degradation, and lifetime of graphite and Si-containing carbon-based negative electrodes in lithium-ion batteries. However, SEI claims are often difficult to compare because measured signals, inferred assignments, sample history, and electrode architecture are [...] Read more.
Solid electrolyte interphase (SEI) characterization is needed to interpret the performance, degradation, and lifetime of graphite and Si-containing carbon-based negative electrodes in lithium-ion batteries. However, SEI claims are often difficult to compare because measured signals, inferred assignments, sample history, and electrode architecture are not always clearly separated. This review presents a claim-bounded framework for SEI characterization that distinguishes direct observables from inferred chemical, molecular, structural, morphological, and functional information. Photoelectron spectroscopy methods provide chemical-state and relative-depth-sensitivity constraints; secondary-ion mass spectrometry methods provide fragment and isotope distributions; vibrational spectroscopies support functional-group and local vibrational evidence; nuclear magnetic resonance and molecular mass spectrometry provide molecular or product-level constraints; and microscopy, tomography, and atomic force microscopy provide morphology, architecture, local thickness, topography, and mechanical response. Across these methods, rinsing, drying, sputtering, beam exposure, extraction, and limited sampling can alter the observable and therefore the defensible claim. The review emphasizes the distinction between native electrode-associated SEI features and extracted, soluble, or electrolyte-phase products, and between morphology-only evidence and chemically assigned morphology. It concludes by proposing claim-driven correlative workflows and reporting guidance for reproducible interpretation on graphite, Si/graphite, Si/C, and carbon-coated Si architectures where directly studied or present. Full article
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44 pages, 73650 KB  
Review
Quality Assessment in Frozen Seafood: Advances in Sensing Technologies and Artificial Intelligence
by Mubeen Tageldin Omer Mohamed, Xorlali Nunekpeku, Nama Yaa Akyea Prempeh, Wenjing Jiang and Huanhuan Li
Foods 2026, 15(16), 2799; https://doi.org/10.3390/foods15162799 - 10 Aug 2026
Viewed by 384
Abstract
Frozen seafood plays an important role in the global food supply, but maintaining its quality during frozen storage and cold-chain distribution remains a significant challenge. Although freezing effectively slows microbial growth and enzymatic activity, it cannot completely prevent quality deterioration. During frozen storage, [...] Read more.
Frozen seafood plays an important role in the global food supply, but maintaining its quality during frozen storage and cold-chain distribution remains a significant challenge. Although freezing effectively slows microbial growth and enzymatic activity, it cannot completely prevent quality deterioration. During frozen storage, seafood undergoes a series of interconnected physicochemical changes, including ice crystal growth, protein denaturation and oxidation, lipid oxidation, water redistribution, and texture deterioration. These changes gradually reduce sensory quality, nutritional value, and overall commercial acceptability. Conventional quality assessment methods, including destructive laboratory analyses and sensory evaluation, are still widely used. However, they are often labor-intensive, time-consuming, and unsuitable for rapid or real-time monitoring in modern cold-chain systems. As a result, increasing attention has been given to non-destructive sensing technologies that can evaluate seafood quality quickly and objectively. This review summarizes the major mechanisms responsible for quality deterioration in frozen seafood, together with recent advances in sensing technologies used to monitor these changes. The sensing approaches discussed include near-infrared (NIR) and Raman spectroscopy, hyperspectral and fluorescence imaging, low-field nuclear magnetic resonance (LF-NMR), electronic nose (E-nose), electronic tongue (E-tongue), colorimetric sensor arrays (CSAs), and biosensors. This review also discusses the growing role of artificial intelligence in frozen seafood quality assessment, including chemometrics, machine learning, deep learning, and multi-sensor data fusion. Particular attention is given to their applications in quality prediction, industrial implementation, and decision support. Finally, current challenges and future research needs are highlighted, with emphasis on the development of interpretable, transferable, and real-time monitoring systems that can support more reliable quality assurance throughout the frozen seafood supply chain. Full article
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31 pages, 1583 KB  
Article
Antimicrobial Trioxacarcin 1,2-Dihydroxyanthraquinones from the Bacterium Streptomyces sp. 127Q Isolated from the Stingless Bee Tetragonula carbonaria
by Anastasiia Filimonova and Dieter Spiteller
Biomolecules 2026, 16(8), 1159; https://doi.org/10.3390/biom16081159 - 10 Aug 2026
Viewed by 344
Abstract
In contrast to honeybees, the Australian stingless bee Tetragonula carbonaria appears to be robust against microbial pathogens. Streptomyces sp. 127Q, isolated from T. carbonaria, inhibited the growth of Lysinibacillus sphaericus, which is the only microorganism reported to affect T. carbonaria. [...] Read more.
In contrast to honeybees, the Australian stingless bee Tetragonula carbonaria appears to be robust against microbial pathogens. Streptomyces sp. 127Q, isolated from T. carbonaria, inhibited the growth of Lysinibacillus sphaericus, which is the only microorganism reported to affect T. carbonaria. The antimicrobials were purified from Streptomyces sp. 127Q by bioassay-guided isolation using ethyl acetate extraction and Diaion HP20 chromatography, followed by reverse phase HPLC fractionation. The antimicrobial compounds were identified by high-resolution mass spectrometry, UV-Vis-spectroscopy, nuclear magnetic resonance spectroscopy, and genome mining as new members of the trioxacarcin/gutingimycin family having a 1,2-dihydroxyanthraquinone aromatic core structure. A closely related gutingimycin with a 1,2-dihydroxyanthraquinone moiety was previously observed in a crystallisation experiment of trioxacarcin A with an oligonucleotide. Streptomyces sp. 127Q produces a wide range of trioxacarcins/gutingimycins. At the onset of trioxacarcins production, Streptomyces sp. 127Q appeared to rapidly convert trioxacarcin epoxides with water, guanine, and nicotinic acid. The 1,2-dihydroxyanthraquinone trioxacarcins, trioxacarcin 692 and trioxacarcin 780, inhibited L. sphaericus with minimal inhibitory concentrations (MICs) of 37.5 μM and 75 μM, respectively. The MIC against Escherichia coli and Staphylococcus aureus was 75 μM and 150 μM, respectively. In the photoantimicrobial screening, the MIC for trioxacarcin 692 against E. coli and S. aureus decreased by 8-fold, and for trioxacarcin 780 by 4-fold. Following light pretreatment, trioxacarcin 692 (9.4 μM) inhibited E. coli and S. aureus at concentrations comparable to those of the established antibiotics ciprofloxacin and vancomycin. Neisseria gonorrhoeae was only inhibited at an MIC of ca. 18.8 μM after light preincubation. The 1,2-dihydroxyanthraquinone trioxacarcins constitute powerful antimicrobial compounds belonging to the trioxacarcin/gutingimycin family. Full article
(This article belongs to the Section Chemical Biology)
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29 pages, 22506 KB  
Article
The Characterization of a New AG-II-like Glycoprotein from Cynanchum thesioides (Freyn) K. Schum and Its Immunostimulatory Activity Through Activation of TLR4/9-Mediated MAPK/NF-κB Signaling Pathways
by Mu Dan, Peng Zhao, Lu Ga, Wenming Bai, Pengwei Zhao, Han Ge, Ruirui Wang, Surina Bo and Munkhtsetseg Baatar
Curr. Issues Mol. Biol. 2026, 48(8), 804; https://doi.org/10.3390/cimb48080804 - 8 Aug 2026
Viewed by 197
Abstract
The structural and immunomodulatory properties of arabinogalactan proteins (AGPs) from edible medicinal plants remain largely unexplored. Here, A homogenous AG-II-like arabinogalactan protein (CTSP-W2, 9862 Da) was isolated from Cynanchum thesioides via hot-water extraction, ethanol precipitation, and column chromatography. Its structure was thoroughly characterized [...] Read more.
The structural and immunomodulatory properties of arabinogalactan proteins (AGPs) from edible medicinal plants remain largely unexplored. Here, A homogenous AG-II-like arabinogalactan protein (CTSP-W2, 9862 Da) was isolated from Cynanchum thesioides via hot-water extraction, ethanol precipitation, and column chromatography. Its structure was thoroughly characterized by high-performance gel permeation chromatography (HPGPC), Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), Congo-red, scanning electron microscopy (SEM), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), methylation analysis. The mechanism of immune activity was examined using specific inhibitors, Western blotting, and molecular docking. It comprises galactose, arabinose, glucose, galacturonic acid, xylose, and 18 amino acids (asparagine-rich), with a backbone of →3,6)-Galp-(1→ and →6)-Galp-(1→. CTSP-W2 significantly enhanced macrophage proliferation, phagocytosis, and secretion of Nitric oxide (NO), Tumor necrosis factor-alpha (TNF-α), and Interleukin-6 (IL-6). Inhibitor assays showed that Toll-like receptor 4 (TLR4, TAK-242) and Toll-like receptor 9 (TLR9, E6446) antagonists markedly reduced CTSP-W2-induced TNF-α, IL-6, and NO in a dose-dependent manner, whereas Toll-like receptor 2 (TLR2) inhibition (C29) unexpectedly upregulated these mediators. Western blot revealed that CTSP-W2 upregulated TLR4 and TLR9 protein expression and increased phosphorylation of Inhibitor of nuclear factor kappa-B alpha (IκBα), nuclear factor kappa B (NF-κB p65), and p38, indicating activation of the TLR4/9–NF-κB–p38 mitogen-activated protein kinase (MAPK) signaling axis. Furthermore, Molecular docking analysis further indicated that CTSP-W2 forms extremely strong hydrogen-bonding and hydrophobic interactions with TLR4 through its galactose chains. This study elucidates the immunoregulatory mechanism of CTSP-W2 and establishes a molecular basis for arabinogalactan proteins as potential natural immunomodulators. Full article
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21 pages, 1872 KB  
Article
Production and Characterization of Poly(3-hydroxybutyrate) by Thermophilic Geobacillus sp. Strain SL28 Isolated from a Natural Hot Spring
by Duc Quan Nguyen, Thi Trang Do, Nhung Thi Hong Lai, Minh Thi Tuyet Phan, Tu Thi Minh Hoa and Thoa Kim Nguyen
Processes 2026, 14(16), 2539; https://doi.org/10.3390/pr14162539 - 7 Aug 2026
Viewed by 571
Abstract
Polyhydroxyalkanoates (PHAs) are biodegradable microbial polyesters that may reduce dependence on petroleum-derived plastics, but broader use remains constrained by production costs and tightly controlled cultivation. Thermophilic microorganisms have attracted increasing attention as promising PHA producers because they can be cultivated at elevated temperatures, [...] Read more.
Polyhydroxyalkanoates (PHAs) are biodegradable microbial polyesters that may reduce dependence on petroleum-derived plastics, but broader use remains constrained by production costs and tightly controlled cultivation. Thermophilic microorganisms have attracted increasing attention as promising PHA producers because they can be cultivated at elevated temperatures, reducing contamination risks and operational costs. In this study, a thermophilic Geobacillus sp. strain SL28 isolated from a Vietnamese hot spring was evaluated for its PHA-producing capability. Temperature, initial pH, carbon and nitrogen sources, C/N ratio, and cultivation time were examined. Intracellular inclusions were assessed by Sudan Black B and Nile Blue A staining and transmission electron microscopy, whereas the recovered polymer was characterized by FE-SEM, Fourier-transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), 1H- and 13C-nuclear magnetic resonance (NMR) spectroscopy, capillary viscometry, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. Under the optimized cultivation conditions identified by one-factor experimentation (50 °C, pH 7.0, sucrose, peptone, C/N 25:1, and 72 h), SL28 reached a dry cell weight of 2.215 ± 0.16 g/L and a PHA concentration of 1.383 ± 0.04 g/L, equivalent to 62.57 ± 2.82% of DCW. Structural characterization confirmed that the recovered polymer was poly(3-hydroxybutyrate) (PHB). The purified PHB also exhibited favorable thermal stability, a relatively high molecular weight, and satisfactory mechanical properties. These results demonstrate the potential of thermophilic Geobacillus sp. SL28 as a promising candidate for PHB production. Full article
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31 pages, 4149 KB  
Article
Hydrophilic PVI-HEA-Based Osmium Redox Polymers for Enhanced Electrochemical Glucose Sensing
by Tae-Won Seo, Won-Yong Jeon, Hyug-Han Kim and Young-Bong Choi
Biosensors 2026, 16(8), 430; https://doi.org/10.3390/bios16080430 - 7 Aug 2026
Viewed by 388
Abstract
Hydrophilic osmium(Os)-based redox polymers were designed as electron-transfer mediators for fungal flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH)-based glucose sensors. Poly(vinylimidazole-co-hydroxyethyl acrylate) (PVI-HEA) copolymers with different HEA compositions were synthesized and coordinated with Os(dmo-bpy)2Cl2 to prepare PVI-HEA-Os(dmo-bpy)2Cl2 redox [...] Read more.
Hydrophilic osmium(Os)-based redox polymers were designed as electron-transfer mediators for fungal flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH)-based glucose sensors. Poly(vinylimidazole-co-hydroxyethyl acrylate) (PVI-HEA) copolymers with different HEA compositions were synthesized and coordinated with Os(dmo-bpy)2Cl2 to prepare PVI-HEA-Os(dmo-bpy)2Cl2 redox mediators. The synthesized mediator systems were characterized using 1H-nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, field emission scanning electron microscopy/energy dispersive spectroscopy, zeta potential analysis, cyclic voltammetry, and electrochemical impedance spectroscopy. The results confirmed the successful formation of Os redox polymer structures and their immobilization on the electrode surface. The electrochemical behavior and glucose sensing performance strongly depended on the PVI-HEA composition. Among the compositions tested, PVI-HEA(3.5:1)-Os(dmo-bpy)2Cl2 showed the strongest redox current response, stable aqueous dispersion behavior, and relatively low interfacial charge-transfer resistance. Glucose-sensing measurements using FAD-GDH/mediator-modified electrodes showed linear current responses over the glucose concentration range of 1.25–20 mM. The PVI-HEA(3.5:1)-Os(dmo-bpy)2Cl2-based electrode showed the highest sensitivity of 16.18 μA cm−2 mM−1, which was significantly higher than those observed at lower-HEA compositions. The optimized mediator system also showed selective glucose responses against representative biological interferents, including ascorbic acid, uric acid, dopamine, and serotonin. Stable catalytic current responses were maintained under Human Plasma-Like Medium conditions, suggesting improved matrix tolerance compared to conventional PVI-based Os redox polymers. The improved sensing performance was attributed to the hydrophilic polymer environment introduced by the HEA units, which may facilitate favorable interfacial charge-transfer behavior within the enzyme–mediator layer. The results show that the hydrophilic copolymer composition plays an important role in the electrochemical behavior and glucose sensing performance of Os redox polymer mediators. The proposed PVI-HEA-Os(dmo-bpy)2Cl2 system may be a promising candidate for future enzymatic glucose sensing and continuous glucose monitoring-related applications. Full article
(This article belongs to the Special Issue Recent Advances in Glucose Biosensors—2nd Edition)
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Article
Untargeted 1H-NMR Metabolomics Identifies Candidate Metabolic Changes Associated with Watercress (Nasturtium officinale R.Br.) Supplementation in Adults with Low-to-Moderate Cardiovascular Risk: A Randomized Placebo-Controlled Trial
by Chikondi Maluwa, Blecious Zinan’dala, Praporn Kijkuokool, Puriwat Fakfum, Churdsak Jaikang, Giatgong Konguthaithip, Wason Parklak, Hataichanok Chuljerm and Kanokwan Kulprachakarn
Nutrients 2026, 18(15), 2559; https://doi.org/10.3390/nu18152559 - 5 Aug 2026
Viewed by 571
Abstract
Background/Objectives: Watercress (Nasturtium officinale R.Br.) is a glucosinolate-rich cruciferous vegetable with reported cardioprotective properties. However, previous human studies have relied on targeted clinical and biochemical biomarkers, limiting insight into its broader metabolic effects. This exploratory study investigated plasma metabolomic changes associated with [...] Read more.
Background/Objectives: Watercress (Nasturtium officinale R.Br.) is a glucosinolate-rich cruciferous vegetable with reported cardioprotective properties. However, previous human studies have relied on targeted clinical and biochemical biomarkers, limiting insight into its broader metabolic effects. This exploratory study investigated plasma metabolomic changes associated with watercress supplementation in adults with low-to-moderate cardiovascular risk using untargeted proton nuclear magnetic resonance (1H-NMR) spectroscopy. Methods: In this randomized, single-blind, placebo-controlled pilot trial (Thai Clinical Trials Registry: TCTR20251119004), 26 participants aged 40–59 years received dried watercress capsules (8 g/day; approximately 195 mg glucosinolates/day) or placebo for 28 days. Fasting plasma samples collected at baseline and Day 28 underwent untargeted 1H-NMR profiling. Partial least squares-discriminant analysis (PLS-DA) assessed group discrimination, while Kyoto Encyclopedia of Genes and Genomes (KEGG)-based pathway enrichment and topology analyses identified perturbed metabolic pathways. Results: A total of 209 plasma metabolites were identified. PLS-DA demonstrated modest discrimination between groups (Q2 = 0.268), with 27 discriminant metabolites (variable importance in projection > 1.5) involving amino acid, nucleotide, carbohydrate, and gut microbial metabolism. Eighteen metabolic pathways were significantly perturbed, particularly galactose and fructose/mannose metabolism (p < 0.001), together with glycerolipid, purine, glycolysis/gluconeogenesis, and tryptophan metabolism. Watercress supplementation reduced metabolites associated with oxidative DNA damage, inflammatory kynurenine metabolism, and microbial co-metabolism, while increasing glycine and dimethylglycine and altered gut microbial activity. Conventional biomarkers showed a significant decrease in low-density lipoprotein cholesterol but no consistent effects on other lipids. Conclusions: Watercress supplementation was associated with coordinated metabolic alterations across multiple pathways, generating mechanistic hypotheses for its antioxidant and cardiometabolic effects. These findings are exploratory and warrant confirmation in larger, adequately powered clinical trials. Full article
(This article belongs to the Special Issue Nutritional Modulation of Metabolic Pathways in Chronic Diseases)
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