Search Results (683)

In this work, three 3-carboxamidecoumarin derivatives (3b, 3c, and 4) were synthesized and characterized by NMR, IR, and single-crystal X-ray. All compounds maintain an essentially planar coumarin scaffold stabilized by an intramolecular N–H⋯O hydrogen bond (S(6) motif), though compound 4 exhibits a more complex bifurcated S₃²(11)[S(6)S(6)S(5)] network that enhances its conformational rigidity. The crystal packing analysis reveals that while all derivatives form one-dimensional (1D) supramolecular tapes through C–H⋯O interactions, their 3D architectures differ significantly: 3b and 3c rely on a diverse combination of π⋯π stacking and lone pair⋯π contacts, whereas 4 is governed by highly directional stacking between the pyran and pyridine rings. Hirshfeld surface analysis and CE-B3LYP energy framework calculations quantified the balance between intermolecular forces, showing that 3b is dispersion-dominated (H⋯H, 43.5%), while 3c achieves a balanced electrostatic–dispersion regime due to the nitro group, which increases O⋯H/H⋯O contacts to 37.1% and yields the highest stabilization energy (−69.1 kJ/mol). These results demonstrate that the electronic nature of the substituents at the 3- and 6-positions drastically modulates the hierarchy of non-covalent interactions, providing key insights for the crystal engineering of coumarin-based supramolecular systems. Full article

Interactions between resveratrol and biological or carrier systems play a key role in determining its bioavailability, stability, and delivery performance. These interactions involve proteins, lipids, cyclodextrins, nucleic acids, polysaccharides, and other formulation matrices, and are governed by noncovalent forces such as hydrogen bonding, hydrophobic interactions, π–π stacking, and desolvation effects. This review examines how complementary spectroscopic, calorimetric, structural, and computational techniques are used to characterize resveratrol interactions. Fluorescence, UV–visible spectroscopy, circular dichroism, FTIR, NMR, ITC, DSC, X-ray diffraction, molecular docking, and molecular dynamics simulations are discussed according to their contribution to binding analysis, conformational assessment, thermodynamic interpretation, structural organization, and complex stability. By integrating these approaches, this review provides a technique-oriented framework for understanding resveratrol binding and guiding the development of more stable resveratrol-based carrier systems and bioactive formulations. Full article

Zeolite-based composite nanomaterials represent a versatile and mechanistically rich platform for the removal of organic micropollutants (OMPs)—including pharmaceuticals, endocrine-disrupting compounds, pesticides, and per- and polyfluoroalkyl substances (PFAS)—from contaminated water systems. Although pristine zeolite frameworks provide well-defined microporous architectures, tunable Si/Al ratios, and ion-exchange capacity, their intrinsic hydrophilicity restricts interaction diversity and limits performance toward the structurally heterogeneous OMPs prevalent in real aquatic environments. Composite integration with carbonaceous nanophases, functional polymers and surfactants, and catalytically active metal oxide nanoparticles substantially extends this interaction repertoire, yielding multifunctional materials whose adsorption performance exceeds that of the individual components. Drawing on a systematic survey of peer-reviewed literature published between 2016 and 2026, this review develops a mechanism-oriented, structure–property–performance framework examining five dominant adsorption mechanisms—electrostatic attraction, π–π stacking, hydrogen bonding, hydrophobic partitioning, and micropore confinement—in relation to composite nanoarchitecture, surface chemistry, and structural parameters. The modulating influence of realistic water matrix conditions on adsorption efficiency is critically assessed, alongside challenges of regeneration, long-term stability, metal leaching, and the persistent gap between laboratory-scale synthesis and scalable deployment. Priority research directions are identified, including standardized performance evaluation under environmentally representative conditions and rational design of hierarchical multifunctional nanocomposites from earth-abundant and waste-derived precursors. Full article

This study presents the synthesis and use of a novel bamboo-derived magnetic activated carbon (BMAC) for the effective removal of cationic and anionic dyes, specifically methylene blue (MB), methyl orange (MO), and sunset yellow (SY), from aqueous solutions. The adsorbent was synthesized using thermal carbonization and subsequent inclusion of magnetic oxide, yielding a porous structure with improved adsorption and magnetic separation properties. Thorough characterization utilizing SEM, EDX, BET, FTIR, XRD, and TGA/DTA validated the creation of a highly porous material including uniformly dispersed magnetic particles and several surface functional groups. Batch adsorption tests were performed to examine the influences of contact time, adsorbent dosage, initial dye concentration, pH, and temperature. The findings indicated rapid adsorption kinetics, with equilibrium reached in around 60–70 min, and adsorption capacity ranked as MB > MO > SY. Augmenting adsorbent dosage enhanced removal efficiency but diminished adsorption capacity per unit mass due to site unsaturation. The maximum adsorption capacities (q_m) of BMAC were 58.9, 56.3, and 32.7 mg/g for MB, MO, and SY, respectively, as determined from the Langmuir isotherm model, indicating superior performance compared with other reported magnetic activated carbon. The adsorption process was determined to be exothermic and spontaneous, as evidenced by thermodynamic characteristics. The equilibrium data were optimally characterized by the Langmuir isotherm model, indicating monolayer adsorption, whereas the kinetic studies conformed to the pseudo-second-order model, signifying that chemisorption is predominant. The adsorption mechanism encompasses electrostatic interactions, π–π stacking, hydrogen bonding, van der Waals forces, pore filling, and surface complexation with magnetic oxides. The findings indicate that BMAC is an efficient, sustainable, and magnetically recoverable adsorbent for the elimination of both cationic and anionic dyes from wastewater. Full article

Silk fibroin (SF)–polyphenol systems have emerged as a versatile class of gels and hydrogels in which supramolecular interactions and dynamic crosslinking regulate network formation, responsiveness, and multifunctional performance. Polyphenols interact with SF through hydrogen bonding, hydrophobic interactions, π–π stacking, metal coordination, and covalent crosslinking, thereby modulating conformational transitions, gelation behavior, structural stability, and interfacial functionality. These interaction mechanisms enable the development of SF–polyphenol gel systems with tunable mechanical properties, wet adhesion, antioxidant activity, self-healing capability, and stimuli responsiveness. This review summarizes recent advances in SF–polyphenol gels and hydrogels, with particular emphasis on molecular interaction mechanisms, gelation and fabrication strategies, responsive behaviors, and structure–property relationships. Representative preparation approaches, including solution blending, electrospinning, impregnation–adsorption, enzymatic crosslinking, metal–phenolic coordination, and photo-initiated processing, are systematically discussed in relation to their effects on network architecture and functional output. The responsive behaviors of these systems under pH, redox, electrical, thermal, and optical stimuli are also analyzed from the perspective of dynamic gel networks and adaptive material design. Emerging applications of SF–polyphenol gels in bioadhesives, delivery platforms, flexible bioelectronics, wound-related materials, and sustainable functional systems are highlighted. Current limitations associated with polyphenol instability, formulation sensitivity, reproducibility, and scale-up are critically discussed, together with future opportunities for predictive design of gel-based natural polymer systems. This review provides a comprehensive framework for understanding SF–polyphenol gelation and for guiding the development of next-generation multifunctional gels and hydrogels. Full article

Anthocyanin stability substantially determines the postharvest storage quality of red Huajiao (Zanthoxylum bungeanum Maxim.). Herein, the composition of red Huajiao anthocyanins (RHAs) was characterized, and the copigmentation performance of seven phenolic compounds with RHAs was comparatively evaluated, together with verifying their practical efficacy in maintaining the overall quality of red Huajiao during frozen storage. UPLC-Q-TOF-MS/MS analysis identified ten anthocyanin monomers in RHAs, among which delphinidin-3,5-diglucoside (D3,5G, 28.23%), and delphinidin-3-O-glucoside (D3G, 14.86%) were verified as the predominant monomers. Naringin (NA) exhibited an optimal copigmentation effect, achieving a maximum color enhancement rate of 19.46% at a 1:40 molar ratio and a pH of 3.0 at 20 °C, while thermodynamic tests verified the excellent stability of the naringin–RHA complex. The copigmentation interactions between RHAs and copigments were largely attributed to hydrogen bonds, π–π stacking, and alkyl hydrophobic interactions. Considering practical application cost and flavor compatibility, chlorogenic acid (CGA) was selected as the preferred alternative copigment. Frozen storage tests suggested that soaking pretreatment with 10 mmol/L CGA effectively delayed color fading and maintained the integrity of the oil gland and the good sensory quality and color attributes of red Hujiao, with no adverse impacts on its inherent flavor and numbing components. Collectively, phenolic-mediated intermolecular copigmentation represents an efficient technical means for stabilizing color and maintaining the commercial quality of postharvest red Huajiao during frozen storage. Full article

Hexagonal boron nitride (h-BN) is a chemically stable two-dimensional material whose wide band gap and low surface reactivity limit its performance in adsorption and photocatalysis, motivating strategies to tailor its structure. In this work, a mechanochemical approach combining high-energy ball milling with NaOH-assisted treatment was used to induce simultaneous exfoliation and hydroxylation of h-BN, promoting defect generation, reduced crystallinity, interlayer expansion, and incorporation of oxygen-containing groups (B-OH and B-O). These modifications led to band gap narrowing, increased surface polarity, and improved dispersion, enabling the formation of heterogeneous active sites. The hydroxylated material (BN-OH) exhibited high adsorption capacities of 248 mg/g for methylene blue (MB) and 215 mg/g for rhodamine 6G (R6G), following Freundlich behavior, indicative of heterogeneous adsorption governed by electrostatic interactions, π–π stacking, hydrogen bonding, and defect-mediated sites. Under solar irradiation, BN-OH achieved up to 99% degradation of both dyes, following predominantly pseudo-first-order kinetics and outperforming pristine BN; additionally, the kinetic behavior under solar conditions was successfully described using the Behnajady–Modirshahla–Ghanbary (BMG) model, which accurately predicts the two-stage degradation process. Scavenger experiments revealed that ⦁OH radicals dominate MB degradation, while ⦁OH, O₂⦁⁻, and h⁺ contribute to R6G removal. Overall, defect engineering and hydroxyl functionalization synergistically enhance photocatalytic performance, providing a scalable strategy for wastewater treatment. Full article

4-Methyl- (1) and 4-ethyl-8-hydroxyquinoline (2) crystallize from a mixture of diethyl ether and chloroform in the triclinic space group P$\overline{1}$. X-ray analysis reveals that both compounds form discrete molecular dimers stabilized by intermolecular O-H∙∙∙N and C-H∙∙∙O hydrogen bonds, resulting in $R_2^2\left(5\right)$ cyclic synthons. This pattern of hydrogen bonds is further stabilized by intramolecular O-H∙∙∙N bonds so that the quinoline nitrogen atom acts as a bifurcated binding site. The dimers exhibit a planar geometry and arrange into layer-like structures held together by π∙∙∙π stacking and van der Waals forces. While the fundamental bonding motifs are similar, the increased steric demand of the ethyl group in compound 2 induces a shift in the crystallographic orientation of the layers and alters the degree of π-overlap compared to the methyl-substituted analogue 1. Full article

The complete removal of persistent aromatic organic pollutants from aqueous environments demands the development of sustainable and highly efficient filtration materials. In this study, novel bio-sourced mixed-matrix membranes (MMMs) were successfully fabricated by incorporating the highly porous metal–organic framework MIL-68(Al) into a biodegradable polylactic acid (PLA) matrix via a solvent-induced phase inversion method. The integration of MIL-68(Al) nanoparticles significantly tailored the membrane’s morphological structure, endowing the hybrid membranes with enhanced surface hydrophilicity (water contact angle reduced from 90.3° to 72.7°) and superior permeability. The pure water flux reached an optimal value of 42.2 L m⁻² h⁻¹ at a 15 wt.% MOF loading. Crucially, the hybrid membranes exhibited exceptionally high adsorptive removal performance for p-nitrophenol (PNP) and methylene blue (MB). Driven by the abundant accessible active sites of the MOF filler, the MIL-20/PLA membrane achieved a maximum equilibrium adsorption capacity of 121.03 μg/cm² (36.90 mg/g) for PNP, representing a remarkable 25.7-fold enhancement over the pristine PLA membrane. Kinetic analyses confirmed that the adsorption process is strictly governed by pseudo-second-order kinetics, indicating a chemisorption mechanism dominated by hydrogen bonding and π–π stacking interactions. Furthermore, the optimized membranes demonstrated outstanding dynamic filtration efficiencies (>80%) and robust regenerability over multiple continuous operating cycles. This work not only highlights the synergistic interfacial effects between MOFs and biodegradable polymers but also provides a highly effective, eco-friendly, and sustainable membrane platform for the advanced remediation of organic-contaminated wastewater. Full article

Protein recognition underpins advances in drug discovery, immunoassays, clinical diagnostics and biosensing. As a biomimetic alternative to natural receptors, molecularly imprinted polymers (MIPs) have been developed to emulate antibody–antigen complementarity by generating binding cavities that mirror the size, shape and functionality of target macromolecules through template-directed polymerization and subsequent template removal. However, protein imprinting has historically been hampered by low imprinting efficiency and limited selectivity, rendering conventional protein-imprinted polymers (PIPs) inadequate for many contemporary biomedical applications. Functional ionic liquids (ILs)—a class of designer solvents and materials distinguished by tunable structures, exceptional physicochemical properties and favorable biocompatibility—have emerged as versatile additives to address the principal limitations of traditional PIPs, including poor selectivity, sluggish mass transfer and destabilization of protein conformation. Here, we provide a systematic review of the multifaceted roles that ILs play within protein-imprinting systems, delineating their employment as template-anchoring motifs, functional monomers, cross-linkers, porogens and structural stabilizers, and evaluating the consequent effects on polymer architecture and recognition performance. We further probe the multiplicity of non-covalent interactions between ILs and template proteins—highlighting the synergistic modulation afforded by electrostatic forces, hydrogen bonding, hydrophobic interactions and π-π stacking—and consider how such interplay can be harnessed to fine-tune binding-site fidelity. Consolidating recent progress, we summarize IL-enabled PIP applications in protein-specific recognition, biosensor development and analysis of complex real-world samples, and we critically examine the prevailing technical challenges and prospects for translation. The evidence indicates that ILs, by furnishing abundant interaction sites, accelerating mass transport and stabilizing native protein conformations, can markedly enhance PIP adsorption capacity, target specificity and recyclability, positioning them as a cornerstone for next-generation protein separation and enrichment materials and paving the way toward industrial deployment of protein-imprinting technologies. Full article

Alzheimer’s disease (AD) is a common neurodegenerative disorder linked to cholinergic dysfunction, with butyrylcholinesterase (BChE) being a key therapeutic target for moderate–severe AD. Cortex Mori Radicis, a traditional Chinese medicinal herb, is rich in Diels–Alder adducts with potential neuroprotective effects; here, eighteen Diels–Alder adducts (four new: morusalbanol B–E, 1–4) were isolated and identified from its 80% ethanol extract. Their cholinesterase inhibitory activities were assessed via Ellman’s method, with enzyme kinetics and molecular docking performed for active compounds. Most compounds showed selective BChE inhibition, with kuwanon X (14) being the most potent (IC₅₀ = 2.3 μM). morusalbanol B (1), cathayanon A (8), and kuwanon G (12) acted as noncompetitive inhibitors, while Morusalbanol C (2) and kuwanon X (14) were mixed competitive inhibitors. Molecular docking suggested that potent inhibitors occupied the BChE active pocket via hydrogen bonds, π-π stacking, and hydrophobic interactions with Trp82, His438, and Phe329. MD simulations and MM-GBSA binding free energy analysis further verified that all three representative complexes (1, 8, and 14) achieved favorable thermodynamic and structural stability, with binding driven primarily by van der Waals forces. Residue decomposition revealed that Trp82 and Phe329 served as core binding hotspots for all tested inhibitors. Structure–activity analysis indicated that a cis-trans methylcyclohexene configuration, shorter aliphatic ester chains, and more prenyl groups enhanced BChE inhibition. This study provides new lead compounds and a systematic molecular mechanism basis for developing novel anti-AD BChE inhibitors from natural products. Full article

Phosphorus is an indispensable key element in life systems and materials science. Here in this work, several cyanoterphenyl-based phosphinic acid-bridged liquid crystal (LC) dimers of 2(CTOn)P (n = 6, 11) and their methyl esterification derivatives of 2(CTOn)P1E have been synthesized through hydrophosphination reaction followed by Suzuki coupling. The cyanoterphenyl LC dimers of 2(CTOn)P and methyl esterified 2(CTOn)P1E exhibit rich enantiotropic LC mesophases such as nematic (N), smectic A (SmA) and highly ordered smectic E (SmE), rather than the monotropic N or twist bend nematic (N_TB) displayed by the analogous phosphinic acid-bridged cyanobiphenyl LC dimers of 2(CBOn)P as reported previously. The phase transition temperatures of the cyanoterphenyl LC dimers 2(CTOn)P are also significantly higher than those of the cyanobiphenyl series, which is attributed to the larger π-conjugated system of cyanoterphenyl as compared with cyanobiphenyl, resulting in much enhanced π-π stacking interactions. However, the significantly enhanced interactions also make them extremely insoluble; thus, a different two-step synthesis pathway combining hydrophosphination with Suzuki coupling reactions was adopted. It is worth pointing out that by combining multiple characterization techniques, including DEPT 135°, ¹³C NMR, and HR-MS spectra, the definite molecular composition and structure of a byproduct with a third pro-mesogen attached via a branching alkyl spacer has been unambiguously demonstrated, which evidently deepens our understanding of the free radical-mediated hydrophosphination reaction mechanism, thereby providing valuable guidance for diminishing side reactions and achieving well-preparation of the high-purity phosphorus-containing LC dimers. Such phosphinic acid functionalized LC materials are envisioned to bear some unique application prospects. Full article

Tetracycline antibiotics are increasingly detected in aquatic environments because of their ecological risks and persistence, while conventional wastewater treatment processes are often insufficient for their effective removal from water. Here, we introduce a novel 3D graphene oxide-based nanocomposite that stacks Cu-NPs and amino-functionalized MIL-101(Fe) (denoted by Cu/NH₂-MIL-101(Fe)@GO) to effectively remove tetracycline (TC) and oxytetracycline (OTC) from environmental water samples. XPS, XRD, TEM, SEM, and FTIR analyses were conducted to characterize the structure and surface morphology of the Cu/NH₂-MIL-101(Fe)@GO nanocomposite. Overall, it was confirmed that GO, NH₂-MIL-101(Fe), and Cu-NPs were successfully incorporated, resulting in a porous material with high access to Cu-related sites as well as oxygen- and nitrogen-based functionalities (such as amino-, hydroxy-, and carboxy-groups). This hybrid system facilitates the adsorption by complementary mechanisms like surface complexation/chelation at Cu and Fe centers with the pH-dependent tetracycline species in electrostatic interactions, hydrogen bonding, π–π stacking, and molecule confinement in the metal–organic framework (MOF) pores, and by the synergistic effects at the GO–MOF(Fe)–Cu junction interfaces. The batch adsorption studies showed that the quick and efficient uptake of the two antibiotics at pH 6.5, with removal rates of 99.65–99.83%, was achieved by 15.0 mg of Cu/NH₂-MIL-101(Fe)@GO at an initial concentration of 20 ppm in 40 min at 25 °C. Equilibrium data were found to be well-fitted by the Langmuir isotherm (R² = 0.908–0.909), suggesting monolayer-dominated adsorption with the maximum capacity of 769.8–775.2 mg g⁻¹. The adsorption kinetics was well-described by the pseudo-second order model (R² = 0.9641–0.9749), which agreed with the strong binding between the tetracyclines and active sites of the nanocomposite. The main novelty of this work consists of the design of a single recoverable platform integrating GO-based preconcentration, pore accessibility of NH₂-MIL-101(Fe), and Cu-driven complexation, which led to the strong removal of tetracyclines under a relevant range of water conditions. These findings demonstrate that Cu/NH₂-MIL-101(Fe)@GO could serve as a promising high-efficiency and potentially reusable adsorbent for removing tetracycline from aqueous solution, which provides a more sustainable approach for pharmaceutical wastewater treatment. Full article

The PGPR strain of Bacillus amyloliquefaciens MHR24 (MHR24) was recently reported as a strong biocontrol strain. In this study, MHR24 was used to investigate phyllosphere effects during inoculations of tomato leaves (Solanum lycopersicum L.). When MHR24 was inoculated on foliar tissue, it caused apical chlorosis symptoms at 3–6 days after infiltration or submersion, which suggests that the bacterium may adopt a potentially pathogenic lifestyle in the phyllosphere. In order to detect the MHR24 interaction with the plant, it was stained with the commercial fluorophore 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, selected from a pyrene series bearing diverse functional groups, based on several in vitro staining assays. Fluorescence used as a detection signal was observed by LSCM mainly in the vascular bundles, suggesting that rhizobacteria may preferentially colonize these tissue regions. Molecular docking, performed by analyzing the possible interactions between the outer membrane protein assembly factor BamB of the family protein B. amyloliquefaciens and the fluorophore, indicates that hydrogen bonds with serine 126 (SER126), serine 182 (SER182), isoleucine 180 (ILE180), and tryptophan 66 (TRP66), charges attraction and π-stacking with TRP66, and non-bonded attractions with leucine 224 (LEU224) can occur, which likely gives rise to a stable complex. These results are important in view of the application of MHR24 as part of a sustainable approach for increasing tomato crop production. Full article

Micro- and nanoplastic pollution poses an emerging challenge for aquatic environments, driving the need for efficient and scalable removal strategies. Functional polymeric materials (FPMs) have emerged as a versatile platform to address this issue, owing to their tunable chemical composition, structural diversity, and ability to promote multiple removal mechanisms, including adsorption, filtration, and coagulation/flocculation. This review provides an overview of recent advances in polymer-based strategies for the removal of micro- and nanoplastics, with emphasis on material design, interaction mechanisms, and process performance. A broad range of materials, including natural hydrogels, polysaccharide aerogels, synthetic polymer composites, magnetic hybrids, and metal–organic frameworks (MOFs)–polymer systems, have demonstrated high removal efficiencies through electrostatic interactions, hydrogen bonding, hydrophobic effects, π–π stacking, and physical entrapment. Removal performance is strongly influenced by surface functionalization, porosity, surface area, and polymer network architecture, enabling targeted design for specific particle types and water matrices. Hybrid and multifunctional materials further enhance capacity and reusability, while natural polymers offer sustainable alternatives. Despite these advances, challenges remain in standardization, scalability, long-term stability, fouling resistance, and economic feasibility under realistic environmental conditions. Future research should focus on sustainable, multi-target, and scalable FPMs, integrating hybrid architectures, stimuli-responsive functionalities, and bioinspired design strategies. Particular attention should be given to mechanistic studies under environmentally relevant conditions and the establishment of structure–property design criteria to enable efficient removal of heterogeneous MPs/NPs mixtures. Overall, functional polymeric materials represent a flexible and high-performance platform for mitigating micro- and nanoplastic contamination, although their successful implementation will depend on bridging the gap between laboratory-scale performance and real-world water treatment applications. Full article