Search Results (28,445)

Ulcerative colitis (UC) is a multifactorial disease characterized by chronic intestinal inflammation and disrupted oxidative balance, significantly impairing patients’ quality of life. Tannins, a class of polyphenolic compounds widely distributed in plants, have demonstrated notable therapeutic potential against UC due to their inherent antioxidant and anti-inflammatory properties. This study employs a systematic literature review of databases, including PubMed and Web of Science, to investigate the molecular mechanisms by which tannins restore intestinal inflammatory and oxidative homeostasis. The findings indicate that tannins directly scavenge reactive oxygen species (ROS) via their polyphenolic structure, mitigate oxidative damage, upregulate antioxidant enzyme expression, suppress pro-inflammatory cytokine secretion, and preserve intestinal barrier integrity. Despite their significant therapeutic promise, challenges such as low bioavailability and structural complexity remain. Future research should prioritize bioavailability enhancement, clarification of structure-activity relationships, and translational studies to facilitate the clinical application of tannin-based therapies for UC. Full article

The transition from petrochemical plastics to sustainable biopolymers has created a critical demand for functional materials that do not compromise on performance. Starch and zein, due to their abundance and complementary nature, represent not just a chemical pair, but a techno-economic symbiosis: zein provides the hydrophobic shield, while starch offers the cost-effective structural volume. This review adopts a “Puzzle Theory” framework to synthesize over 80 peer-reviewed studies published between 2014 and 2025, categorizing the literature into established structural knowledge and unresolved functional limitations. Our analysis reveals that while fabrication protocols and molecular synergy are well-defined in approximately 65% of the surveyed literature, critical functional data remain largely absent. Specifically, fewer than 15% of studies investigate hydro-stability in high-humidity environments or bio-interface behavior, creating a disconnect between laboratory success and industrial application. We identify that current research disproportionately prioritizes dry-state morphology over wet-state mechanical integrity. To bridge the gap between academic prototypes and industrial reality, this article moves beyond general recommendations to propose concrete experimental benchmarks, including specific targets for wet mechanical integrity (>1 MPa), regulatory solvent compliance (<50 ppm), and scalable throughput. This article concludes by providing a strategic roadmap to bridge these gaps, arguing that future research must pivot from simple morphological characterization to developing “smart response” mechanisms and “green manufacturing” protocols to ensure commercial viability. Full article

Bitter compounds may function not only as taste substances but also as important active constituents mediating therapeutic effects. Their recognition is primarily mediated by bitter taste receptors (TAS2Rs), which exert pharmacological effects, such as regulating glucose metabolism, anti-inflammatory properties, and immune modulation, aligning closely with the therapeutic effects of bitter Chinese herbal medicine (BCHM). Contemporary pharmacological research has increasingly underscored the therapeutic potential of bitter traditional Chinese medicine (TCM), particularly through their bioactive constituents in the prevention and treatment of diverse pathological conditions. Here, we systematically review the diversity of bitter compounds from TCM and features of TAS2Rs, including their tissue distribution, physiological functions, structural characteristics, signal transduction mechanisms, and single-nucleotide polymorphisms. While numerous bitter phytochemicals have been characterized as agonists of TAS2Rs, the precise physiological functions and underlying molecular mechanisms mediated by TAS2R activation remain incompletely elucidated. This knowledge gap is largely attributable to several methodological and biological challenges, including the widespread tissue distribution of TAS2Rs, the complexity of their downstream signaling cascades, and the structural and functional heterogeneity of bitter compounds. This review outlines theoretical foundations, future perspectives and challenges for the drug development of TAS2R from BCHM. Full article

To develop high-performance iridium phosphorescent complexes, we designed and synthesized a series of iridium phosphorescent complexes (G-1, G-2, B-1, B-2, R-1, R-2) using 3-hydroxy-2-methyl-4-pyrone (maltol, short for mal) and 3-hydroxy-2-ethyl-4-pyrone (ethyl maltol, short for emal) as auxiliary ligands, in combination with 2-phenylpyridine (ppy), 2-(2,4-difluorophenyl)pyridine (dfppy), and 1-phenylisoquinoline (piq) as cyclometalating ligands. We systematically investigated their crystal structures, photophysical behavior, electrochemical properties, and electroluminescent performance. The results revealed that the combination of a pyranone auxiliary ligand with the highly conjugated piq ligand leads to the formation of R-1 and R-2, which possess high molecular symmetry and display favorable photophysical performance. These complexes exhibit solution-phase phosphorescence quantum yields of 64% and 55%, and electroluminescent devices incorporating them reach a maximum external quantum efficiency of 13.4%, with brightness exceeding 13,000 cd/m² and minimal efficiency roll-off. In contrast, complexes incorporating pyridine-based cyclometalating ligands (ppy, dfppy)—G-1, G-2, B-1, and B-2—display weak emission in solution but show enhanced solid-state emission through π–π stacking, with a maximum quantum yield of 25.8%. Density functional theory calculations and electrochemical analysis indicate that the presence of both the pyranone auxiliary ligand and the piq ligand results in optimized frontier orbital energy alignment, enhanced metal-to-ligand charge transfer, and reduced non-radiative transitions, thereby improving emission efficiency. This study provides a theoretical framework and molecular design strategy for the application of pyranone auxiliary ligands in high-performance iridium phosphorescent materials. Full article

Molecular representation learning (MRL) has garnered significant attention due to its pivotal role in downstream applications such as molecular property prediction and drug discovery. In most MRL approaches, molecules are encoded into 2D topological graphs via graph neural network (GNN), which suffers from over-smoothing issues and limited receptive fields. Furthermore, most GNN models fail to utilize the 3D spatial structural information that determines molecular physicochemical properties and biological activity. To this end, here we propose multimodal contrast-enhanced molecular representation learning (MCMRL). This approach utilizes both the 2D topological information and 3D structural information of molecules for contrastive learning to enhance molecular graph representations. Further, it integrates additional molecular fingerprint information and feature fusion techniques to incorporate multimodal knowledge, yielding more reliable and generalizable molecular representations. MCMRL is pre-trained on ~10 million unlabeled molecules from PubChem, followed by various downstream benchmark tasks. Experimental results demonstrate that MCMRL achieves superior performance in 9 out of 13 benchmark tests for molecular property prediction, validating its effectiveness in molecular representation learning. Furthermore, potential molecular drugs binding to biological target protein DRD2 screened by MCMRL representation show promising affinity score, which also demonstrates the efficacy of the proposed method. Full article

In this study, a multicomponent composite film system based on alginate, chitosan, κ-carrageenan, agar, and Rapana venosa protein hydrolysate (RVPH) was developed, and the effect of RVPH incorporation (0–1.5%) on molecular interactions, microstructure, and functional performance was evaluated using FTIR, SEM, mechanical testing, optical analysis, and water-related measurements. FTIR results indicated that RVPH interacted with the polysaccharide matrix mainly through hydrogen bonding and ionic interactions without causing chemical degradation. SEM analysis revealed concentration-dependent microstructural changes, with smoother morphologies at low RVPH levels and increased roughness and heterogeneity at higher concentrations. These structural differences were reflected in the functional properties. All films exhibited high swelling and water solubility. Optical properties were significantly affected by RVPH. Mechanical properties exhibited a non-linear response, with numerical variations observed but no statistically significant differences (p > 0.05). The EDAS and SWARA methods were employed to determine the optimal incorporation level of RVPH in the film formulations. Among the RVPH-containing films, the formulation incorporating 1% RVPH was identified as the most suitable alternative. Full article

RipP1 is a well-characterized avirulence effector that induces a hypersensitive response (HR) in three tobacco species. However, the molecular mechanisms by which host proteins recognize RipP1 to activate a defense response and modulate host–pathogen interactions remain largely unknown. In this study, we screened a Nicotiana benthamiana cDNA library via yeast two-hybrid assay and identified FRIGIDA-like protein 4a (FRL4a) as a host protein interacting with RipP1. Secondary structure analysis of FRL4a and construction of serial mutants revealed that the ClyA-like domain of FRL4a is the key region mediating its interaction with RipP1. Using virus-induced gene silencing (VIGS) and quantitative real-time PCR (qPCR) analysis, we found that the ability of RipP1 to induce HR was significantly attenuated in FRL4a-silenced plants, and RipP1 no longer suppressed the ethylene signaling pathway. Pathogenicity tests by inoculating R. solanacearum on N. benthamiana with different FRL4a expression levels showed enhanced bacterial wilt resistance in FRL4a-silenced plants but increased susceptibility in FRL4a-overexpressing plants. Collectively, these findings demonstrate that RipP1 suppresses the ethylene pathway through its interaction with FRL4a, and FRL4a acts as a negative regulator of tobacco resistance to bacterial wilt. Full article

The discovery of novel anti-infective agents is a continuous challenge in medicinal chemistry, particularly due to the rise in resistant fungal and viral strains. Within this context, the biphenyl subunit has been identified as a highly versatile privileged structure capable of interacting with diverse protein targets via hydrophobic and π-interactions. The purpose of this study is to review the pharmacological potential of biphenyl-based compounds, focusing on their application as anti-infective agents. We comprehensively analyzed recent literature and rational design strategies concerning biphenyl derivatives, examining structure-activity relationships, molecular docking insights, and structural optimizations aimed at enhancing both pharmacodynamics and pharmacokinetics. The reviewed studies demonstrate that incorporating biphenyl moieties yields compounds with potent antifungal and antiviral activities. Specifically, optimized biphenyl derivatives exhibit strong inhibitory effects against resistant Candida strains and crucial viral targets, including mutant variants of the HIV-1 reverse transcriptase and protease enzymes. Furthermore, strategic modifications, such as scaffold hopping and the introduction of specific substituents, successfully mitigated cytotoxicity and improved metabolic stability against cytochrome P450 enzymes. Biphenyl serves as a robust and adaptable scaffold for drug design. Its rational structural optimization provides a viable pathway to overcome drug resistance and develop effective, metabolically stable anti-infective therapeutics. Full article

Excessive lipid accumulation, a hallmark characteristic of high-fat diet (HFD)-induced obesity, has become a worldwide challenge, necessitating the exploration of secure and efficacious natural products for its intervention. In the present work, a polysaccharide (MCP) was extracted and purified from Mesembryanthemum crystallinum L., a novel halophyte, and its physicochemical properties, in vitro fermentation characteristics, lipid-lowering activity, and underlying mechanisms were systematically investigated. Physicochemical analysis revealed that MCP is an acidic polysaccharide, with galacturonic acid as the predominant monosaccharide component, broad molecular weight distribution, and a porous structural morphology. In vitro fermentation experiments demonstrated that MCP could be effectively utilized by human fecal microbiota, significantly promoting the yield of short-chain fatty acids (SCFAs), particularly butyrate at high concentrations, which outperformed inulin. 16S rDNA sequencing uncovered that MCP optimized microbiota composition by enriching SCFA-producing beneficial bacteria (Prevotella_9, Faecalibacterium) while suppressing opportunistic pathogens (Megamonas, Escherichia-Shigella). Metabolomic analysis of fermentation broth revealed that MCP significantly affected microbial glycerophospholipid metabolic pathways. Experiments in Caenorhabditis elegans (C. elegans) confirmed that MCP inhibited HFD-induced lipogenesis, which was linked to the regulation of the nhr-49/sbp-1-mediated lipogenesis pathway. For the first time, using an antibiotic-induced microbiota depletion model in C. elegans, the lipid-lowering effect of MCP was observed to disappear, suggesting a potential role of the gut microbiota in mediating this effect. This investigation establishes a scientific basis for MCP as a novel prebiotic or dietary supplement for managing obesity-related lipid accumulation. Full article

Canine parvovirus (CPV) is a major pathogen causing severe gastroenteritis in dogs. Since its emergence, CPV has undergone continuous evolution, leading to the predominance of variants such as CPV-2a, CPV-2b, and CPV-2c. To characterize the genetic features and evolutionary trends of CPV-2 at a regional level, 775 fecal samples were collected from domestic and stray dogs with suspected CPV-2 infection in Shanghai between 2016 and 2025. The overall positivity rate was 23.2% (180/775); incidence was substantially higher in stray dogs (30.2%) than in domestic dogs (15.9%). Thirty-one CPV-2 strains were successfully isolated. Temporal analysis revealed a pronounced genotype shift: isolates from 2016 to 2020 were predominantly New CPV-2a, whereas CPV-2c became the dominant genotype from 2021 through 2025. Sequence analysis identified the polymorphism of VP2 gene and characteristic mutations F267Y, Y324I, N426E, Q370R and A440T in CPV-2c strains. A novel I447M mutation was detected in several isolates. Phylogenetic analysis showed that Shanghai isolates formed distinct clusters; CPV-2c strains were closely related to the Asian lineage. Structural modeling indicated that mutations at residues L87M, T101I, Y267F, A297S, G300A, Y305D, I324Y, Q370R, N426E, A440T, and I447M may alter the tertiary structure of the VP2 protein, potentially affecting antigenicity and receptor recognition. Collectively, these results demonstrate the complete genotype replacement of CPV-2 in Shanghai; CPV-2c is now predominant. Identification of the novel I447M mutation and structural analysis of key amino acid substitutions provide insight into CPV molecular evolution. These findings suggest that vaccines primarily based on older CPV-2 or CPV-2b genotypes offer suboptimal protection, highlighting the need for updated vaccine strategies targeting prevalent CPV-2c variants. Full article

Inhibition of inflammation and oxidative stress is increasingly recognized as a promising therapeutic strategy for neurodegenerative diseases. In this study, we isolated two new dimeric naphtho-γ-pyrone (aS)-fonsecinones B and D (1 and 2) and 14 known compounds (3–16) from the deep-sea-derived fungus Aspergillus niger 3A00562. Their structures were unambiguously determined through integrated physicochemical and spectroscopic analyses. Screening for neuroinflammatory inhibitors using a BV2 microglial cell model identified TMC 256 A1 (10) as the most potent candidate. Compound 10 significantly suppressed LPS-induced inflammation in BV2 cells without cytotoxicity. It concurrently inhibited LPS-triggered ROS overproduction and neutrophilic infiltration in zebrafish. Subsequent proteomics revealed that 10 targets NOS2 to modulate Alzheimer’s disease (AD)-associated pathways and the KEAP1-NRF2 axis. Molecular docking and dynamics simulations demonstrated that 10 occupies the NOS2 heme-binding pocket, thereby preventing dimerization and inhibiting enzymatic activity. Finally, 10 ameliorated locomotor deficits in an AD zebrafish model. Collectively, these findings highlight compound 10 as a candidate compound for preventing inflammatory and oxidative stress damage during treatment of neurodegenerative diseases, particularly AD. Full article

A novel cyanide-free gold electroplating bath was developed with 2-hydroxyphosphonoacetic acid (HPAA) as the core complexing agent in this work. Scanning electron microscopy (SEM) observations demonstrate that the obtained gold electrodeposits possess a smooth and compact surface morphology. The crystal structure of the gold electrodeposits was characterized via X-ray diffraction (XRD), and the coating–substrate adhesion was systematically evaluated through scratch tests. Molecular dynamics (MD) simulations were performed to investigate the adsorption interaction between HPAA and metal (Au/Ni) surfaces. The MD simulation results show that all the studied phosphonate-containing derivatives can strongly adsorb on the gold surface and exert a significant inhibitory effect on the electroreduction of gold ions during electrodeposition. Cyclic voltammetry (CV) and other electrochemical tests reveal that the cathodic reduction peak potential of gold shifts significantly negatively after the addition of phosphonate-based organic additives, which effectively enhances the cathodic polarization of gold deposition, delays the gold nucleation rate, and refines the grain size of electrodeposits, ultimately yielding gold electrodeposits with a denser and smoother surface. Owing to its environmental benignity, excellent process stability and superior coating performance, this cyanide-free gold electroplating system exhibits broad application prospects in the field of modern green surface engineering. Full article

Precise control over the physicochemical and biological properties of colloidal particles is essential for the rational design of functional soft materials. In this work, we report a simple and scalable strategy for generating modular dendron particles (MDPs) through the self-assembly of fully characterized small-molecule Bis-MPA dendrons that act as programmable molecular building blocks for colloidal particle formation. By systematically varying three structural domains—the inner functionality, methylene spacer length, and outer connector—we achieve tunable formation of MDPs ranging from nano- to microscale dimensions. Upon solvent evaporation under mild drying conditions, pre-assembled MDPs act as structure-directing seeds that guide the emergence of hierarchical surface morphologies with spiky, scaly, or spherical protrusions, depending on dendron architecture. Importantly, these assemblies exhibit good biocompatibility toward non-tumoral bronchial epithelial (NL-20) cells while displaying selective cytotoxicity toward Neuro-2a neuroblastoma cells, demonstrating that dendron molecular architecture alone can govern particle size, morphology, and biological response without external drug loading. Collectively, these findings highlight modular Bis-MPA dendrons as versatile building blocks for directing particle size, morphology, and biological response through controlled self-assembly and evaporation-driven structuring. Full article

Infrared (IR) spectroscopy is a powerful tool for characterizing molecular structures and chemical groups, offering advantages such as low cost, rapid analysis, and non-destructive testing. When analyzing heterogeneous objects, spectra are typically measured from different regions to capture the local variations, presenting a multi-instance learning (MIL) problem. However, existing methods primarily rely on multi-instance assumptions or explicit bag representations, often failing to fully capture the intrinsic information from implicit representations. We introduce a bag dissimilarity regularized MIL framework for analyzing IR spectra of heterogeneous objects, which integrates both explicit and implicit representations to effectively learn the MIL bags. Specifically, a bag dissimilarity regularization term is utilized to extract implicit representations, which subsequently guide the classifier based on explicit representations to enhance generalization performance. The proposed method was validated on two heterogeneous detection tasks: polydimethylsiloxane (PDMS) block assessment and polyethylene terephthalate (PET) fiber inspection. Experimental results demonstrate that our approach significantly outperforms existing methods on both datasets with a considerable margin. Full article

This study investigates the effects of organic salts, including sodium citrate (SC), calcium citrate (CC), and calcium lactate (CL), on the structure–property–function relationships of thermoplastic starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) films for active packaging applications. TPS incorporated with organic salts was prepared via twin-screw extrusion, blended with PBAT, and further processed into blown films. The films were systematically characterized using ¹H NMR, FTIR, and SEM, together with optical, mechanical, water vapor permeability, and antimicrobial evaluations against Staphylococcus aureus. The results revealed that SC primarily modulated hydrogen-bonding interactions within the starch matrix, resulting in improved structural homogeneity, balanced mechanical properties, and the highest antimicrobial activity among all formulations. In contrast, CL and CC promoted ionic crosslinking through Ca²⁺–starch interactions, leading to increased stiffness and Young’s modulus but reduced polymer chain mobility and limited release of active species, particularly in CC-containing systems. These differences in molecular interactions were consistent with variations in film microstructure, where SC-containing films exhibited more uniform morphologies, while calcium-based systems showed denser but less permeable structures. Furthermore, films containing SC and CL at appropriate concentrations achieved a favorable balance between transparency, water vapor barrier properties, and antimicrobial performance. Overall, this study provides new mechanistic insights into how monovalent and divalent organic salts govern intermolecular interactions, microstructure, and functional performance in TPS/PBAT systems. The findings highlight the critical role of additive type and concentration in designing biodegradable active packaging materials with tunable mechanical, barrier, and antimicrobial properties. Full article