Search Results (952)

This study investigated the effects of microwave puffing-induced soy protein structural modification on the dynamic changes in physicochemical properties and umami formation during soybean paste fermentation. The results indicated that optimal microwave puffing (400 W, 90 s) disrupts protein non-covalent bonds, depolymerizes protein aggregates, exposes the internal hydrophobic groups to enhance surface hydrophobicity, forms a loose porous structure, and creates favorable conditions for enzymatic hydrolysis during soybean paste fermentation. Conversely, excessive treatment (400 W, >90 s) induced protein re-aggregation and inhibited proteolysis, as confirmed by SEM. Furthermore, microwave puffing (400 W, 90 s) promoted Aspergillus oryzae growth and protease activity, and significantly improved physicochemical properties of soybean paste, including lower pH and higher contents of total acid (5.8%), amino acid nitrogen (11.8%), small peptides (13.3%), and reducing sugars (14.95%) (p < 0.05), plus a brighter, redder color. LC-MS/MS revealed microwave puffing (400 W, 90 s) reshaped the peptide profile of soybean paste, increasing the relative abundance of the umami amino acids (Glu, Asp) and sweet amino acid (Ala) and decreasing proportions of the bitter amino acids in the peptides. Sensory and electronic tongue analyses confirmed enhanced umami and weaker bitterness and saltiness. These findings demonstrate that microwave puffing (400 W, 90 s) effectively improves the quality and flavor characteristics of soybean paste, providing technical support for high-quality fermented soybean products. Full article

The sustainable isolation of nonamphiphilic phytochemicals remains a formidable challenge in biochemical engineering. In this study, a highly efficient and solvent free foam fractionation process was developed for recovering rosmarinic acid from botanical extracts. By systematically screening diverse biological surfactants, whey soy protein emerged as an exceptionally robust dual functional frother and nanoscale collector. Response surface methodology optimized the operational parameters to 850 mg/L protein concentration, pH 2.5, and a gas flow rate of 470 mL/min, yielding an outstanding target recovery of 93.08 percent alongside an enrichment ratio of 1.81. This macroscopic separation superiority was comprehensively elucidated at the molecular level through multiple spectroscopic techniques and computational modeling. Results confirmed a spontaneous static quenching complexation driven by synergistic noncovalent forces, predominantly hydrogen bonding, van der Waals interactions, π-stacking, and salt bridges. These interactions induced targeted conformational unfolding within the protein backbone, exposing hydrophobic domains that drastically elevated the thermodynamic affinity for the ascending gas–liquid interface. Furthermore, the concentrated product exhibited an antioxidant capacity enhancement exceeding 3.6 times compared to the crude extract, a result attributed to selective enrichment combined with the structural shielding effect provided by the protein macromolecule. Ultimately, this work provides critical mechanistic insights and establishes a scalable technological framework for the green purification of highly valuable botanical compounds. Full article

Impaired wound healing is often caused by persistent inflammation, bacterial infection, and insufficient extracellular matrix remodeling. Natural polymer-based hydrogels represent ideal wound dressings but often struggle to balance structural stability and biological activity. Herein, we report a dual-functional network regulation strategy enabled by highly soluble mussel foot protein (HMFP) that acts simultaneously as a structural crosslinking regulator and bioactive effector to fabricate synergistic hydrogels (CS-SH-H) from β-chitosan (CS) and sodium hyaluronate (SH). HMFP homogenizes the porous microstructure, strengthens intermolecular interactions, and significantly improves thermal and structural stability via multivalent non-covalent bonding. In vitro, CS-SH-H shows excellent cytocompatibility, significantly promotes fibroblast proliferation and migration, and exerts potent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In a mouse full-thickness skin defect model, the hydrogel dramatically accelerates wound closure, reducing the residual wound area to 25% on day 7, outperforming the control groups. Immunohistochemistry confirms that HMFP suppresses TNF-α-mediated inflammation and enhances Ki-67-positive cell proliferation, leading to accelerated re-epithelialization and collagen deposition. This study establishes HMFP as a promising marine-derived dual-functional network regulator for designing high-performance hydrogel dressings. This strategy is scalable and translatable for treating infected and inflammatory wounds. Full article

Carbon nanotubes (CNTs) serve as exceptional multifunctional supports for metal phthalocyanine (MPc)-based electrocatalysts, effectively addressing the inherent limitations of molecular catalysts such as poor conductivity and aggregation. This review systematically summarizes the recent advances in engineering the interface between MPcs and CNTs to optimize performance in sustainable energy conversion and environmental remediation. We categorize the engineering strategies into three synergistic dimensions: (1) dispersion and modification engineering, introducing the most direct physical anchoring dispersion strategy via non-covalent interactions and targeted modifications to yield highly active catalysts; (2) chemical bonding engineering, in which robust axial coordination or covalent grafting creates stable, well-defined active sites and prevents leaching; and (3) geometric and spatial engineering, which exploits CNTs’ unique curvature, atomic defects, inner cavities and one-dimensional architecture to induce strain, symmetry breaking, and nanoconfinement, thereby steering reaction pathways or to construct conductive nanocomposites. These strategies highlight that CNTs are not merely passive scaffolds but active regulators that geometrically and electronically modulate MPcs. By balancing molecular dispersion, charge transfer, and mass transport, CNT-supported MPcs exhibit superior activity, selectivity, and stability for critical electrochemical reactions, including the oxygen reduction reaction (ORR), CO₂ reduction reaction (CO₂RR), and nitrate reduction reaction (NO₃RR), demonstrating substantial potential for advancing sustainable energy technologies and environmental applications. Full article

Organic solar cells (OSCs) are a potential photovoltaic technology because they can be manufactured in scalable systems, are lightweight, and have mechanical flexibility. Power conversion efficiencies close to 20% have been achieved in recent years due to the quick development of donor–acceptor material systems. Better control over nanoscale shape and the creation of non-fullerene acceptors are major factors driving this advancement. Nevertheless, there are still complicated connections between morphology, interfacial energetics, and molecular structure. It is yet unclear how these elements interact to affect charge creation and transport. In this review, donor–acceptor interactions in organic solar cells are examined from a fundamental chemical and physical perspective. From conventional fullerene derivatives to contemporary non-fullerene acceptors, we first look at the development of acceptor materials. We demonstrate how molecular engineering has enhanced device efficiency, energy level adjustment, and light absorption. We then examine the energetic alignment at donor–acceptor interfaces, paying particular attention to charge-transfer state creation, border orbital offsets, and the factors influencing voltage losses. We also investigate how intermolecular interactions, including hydrogen bonding, π-π stacking, and noncovalent interactions involving heteroatoms, control electrical coupling and nanoscale shape in bulk heterojunction active layers. We also go over device engineering techniques including processor control, interface engineering, and bulk heterojunction architecture optimization. These tactics demonstrate how improved solar performance might result from molecular design. Lastly, we highlight new possibilities for next-generation OSCs, such as scalable production techniques, adaptive molecular design, and morphological stabilization. This work provides a strong framework for comprehending donor–acceptor interactions and for directing the careful design of high-performance organic photovoltaic systems by combining knowledge from molecular chemistry, morphological control, and device engineering. Full article

Synthetic dyes from textile effluents represent a major environmental concern due to their persistence and toxicity. Reactive Black 5 (RB5) is widely used in the textile industry and is commonly applied as a model azo compound in sorption studies. This study comparatively evaluates the sorption performance of raw and carbonized sorbents derived from industrial hemp (Cannabis sativa L.) biowaste using an integrated experimental and theoretical approach. The sorbents were prepared through washing, drying, and phosphoric acid-assisted carbonization followed by pyrolysis. Structural and physicochemical properties were characterized using elemental analysis, FTIR spectroscopy, and SEM microscopy. Sorption performance toward RB5 was investigated through batch kinetic and equilibrium experiments, supported by kinetic (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models) and isotherm (Langmuir, Freundlich, and Temkin) modeling. Molecular docking simulations were performed to provide mechanistic insight into dye–sorbent interactions. Both materials exhibited rapid sorption kinetics, reaching equilibrium within approximately 45 min, with the pseudo-second-order model suggesting that surface-controlled interactions dominate the sorption rate. Molecular modeling, based on extensive conformational sampling, indicated a strong binding affinity between RB5 and cellulose-based structures, primarily associated with hydrogen bonding and other favorable noncovalent interactions. In contrast, graphene-based models revealed sorption governed by π–π interactions and confinement effects, supporting the experimentally observed differences between raw and carbonized sorbents. Full article

The efficient capture of carbon dioxide (CO₂) using polymer, supported ionic liquids (ILs) remains challenging due to limited understanding of atomic-scale interaction mechanisms. Here, a polystyrene (PS) oligomer supported by an amidinium chloride-based IL is proposed as a CO₂-absorbing material. Density functional theory (DFT) calculations were employed to investigate the structural, electronic, and intermolecular interaction energy characteristics of the PS oligomer, amidinium chloride ILs, CO₂, and their binary and ternary complexes. Molecular electrostatic potential maps (MEPs), reduced density gradient (RDG) plots with non-covalent interaction (NCI) snapshots, quantum theory of atoms in molecules critical point (CP) analysis, and electron localization function (ELF) analysis reveal pronounced hydrogen bonding and dispersion interactions between PS and IL that modulate the electronic environment of the IL anion, which is the primary CO₂ binding site. Interaction energy calculations show that the ternary PS–IL–CO₂ complex exhibits a significantly enhanced binding energy compared to the isolated IL–CO₂ complex, providing quantitative evidence for the cooperative role of the PS support. The results indicate enhanced CO₂ binding in the presence of PS supported by ILs, driven by cooperative electrostatic and dispersion interactions. These findings provide molecular-level insights into CO₂ capture mechanisms in polymer–IL hybrid systems. Full article

NAD⁺ depletion is a defining feature of the aging cell, driven by a progressive decline in nicotinamide phosphoribosyltransferase (NAMPT) activity, the rate-limiting enzyme of the NAD⁺ salvage pathway. Pyrroloquinoline quinone (PQQ), a plant-derived redox-active quinone cofactor, elevates intracellular NAD⁺ by a mechanism that remains incompletely understood. We employed an integrated in silico approach combining molecular docking, density functional theory (DFT), and 100 ns molecular dynamics (MD) simulation to evaluate whether PQQ directly targets NAMPT. Docking against the NAMPT crystal structure (PDB: 7ENQ) yielded a binding free energy of −9.4 kcal/mol, with PQQ positioned in the allosteric activation site and forming hydrogen bonds at His191, Asp219, and Val242 together with π–π stacking at Tyr188, extending a known synthetic activator pharmacophore to a dietary ligand class. MM-GBSA analysis yielded binding free energy = −31.2 kcal/mol, confirming dominant electrostatic and van der Waals stabilization. In silico alanine mutagenesis of Tyr188 and Val242 reduced binding affinity to −7.2 and −7.0 kcal/mol respectively, with complete loss of allosteric-site contacts, validating the proposed mechanism computationally. DFT analysis revealed a HOMO–LUMO gap of 3.20 eV and electrophilicity index ω = 8.91 eV, consistent with non-covalent binding to nucleophilic residues. MD simulation confirmed retention of PQQ within the allosteric site over 100 ns. These data provide a structural and electronic framework for the NAD⁺-boosting activity of PQQ and a rationale for experimental validation. Full article

Radix Paeoniae Alba, the dried root of Paeonia lactiflora Pall., contains characteristic monoterpene glycosides, but efficient recovery of these polar constituents remains challenging. This study developed an ionic liquid-assisted sequential ultrasound–microwave extraction method and evaluated paeoniflorin, oxypaeoniflorin and albiflorin by HPLC as multi-marker responses. Among the ionic liquids tested, 1-propyl-3-methylimidazolium dihydrogen phosphate showed the best extraction response. Box–Behnken response surface optimization gave practical extraction conditions of a solid-to-liquid ratio of 1:26 g/mL, ionic liquid concentration of 0.12 mol/L and ultrasound time of 22 min. Under these conditions, paeoniflorin and total marker glycosides reached 29.12 and 34.98 mg/g dry material, respectively, representing increases of 32.4% and 34.5% compared with conventional reflux extraction. UPLC-QTOF-MS profiling provided complementary chemical profile information for the optimized extract and tentatively annotated Paeonia-related monoterpene glycoside derivatives, galloylated glucose derivatives and polyphenolic constituents. Electrostatic potential, SAPT and non-covalent interaction analyses, supported by ¹H NMR chemical shift perturbation, suggested possible hydrogen bonding, electrostatic and dispersion interactions between paeoniflorin and the selected ionic liquid. These results support the optimized process as an efficient extraction approach and provide molecular interaction insights into ionic liquid-assisted recovery of monoterpene glycosides. Full article

The nucleophilic properties of the isolated dicyanoaurate(I) anion in σ-hole interactions were investigated using theoretical calculations of models from 19 crystalline literature structures. The study focuses on the ability of [Au(CN)₂]⁻ to participate in various noncovalent interactions, including halogen, chalcogen, pnictogen, and tetrel bonds. The research reveals that both nitrogen atoms of the cyanide ligands and the gold(I) center exhibit nucleophilic behavior. The nature of all interactions and philicities of interacting atoms were confirmed using a set of theoretical methods, including QTAIM topological analysis, noncovalent interaction plots (NCIplot), electrostatic potential (ESP) surfaces, electron localization function (ELF), analysis of electron density (ED), and electrostatic potential (ESP) minima in their 1D profiles along the bond paths, BSSE corrected dimerization energies, and NBO charge-transfer analysis. The study demonstrates that the dicyanoaurate(I) anion can act as a versatile building block in supramolecular chemistry, participating in multiple types of noncovalent interactions through different sites, including first confirmed examples of gold(I)-involving intermolecular chalcogen bonds. Full article

Melanin pigments protect human tissues from ultraviolet and visible radiation, yet their phototoxic potential increases with oxidative degradation. This computational study investigates how the oxidation state influences the first excited states of eu- and pheomelanin using molecular models of varying complexity (monomers to tetramers, both covalently and non-covalently bonded). First, vertical and adiabatic electronic transitions were computed, and supramolecular interactions were characterized with the ETS-NOCV method. In eumelanin, oxidation drastically lowers the first triplet-state (T₁) energies (from above 230 kJ/mol) to levels comparable to retinal carotenoids (≤66 kJ/mol), emphasizing its role in triplet quenching rather than singlet oxygen generation. Pheomelanin showed greater heterogeneity in the values of the first triplet state, staying mostly above the eumelanin T₁ energies. However, selected pheomelanin structures also exhibited relatively low triplet energies, particularly oxidized benzothiazole (BZox) and trichochromes, and although their T₁ energetics remained higher than those calculated for oxidized eumelanin, they were still sufficiently low to suggest a potential ability to quench singlet oxygen. Furthermore, supramolecular analysis reveals that eumelanin aggregates are moderately stabilized by both π-π stacking and hydrogen bonding, whereas pheomelanin aggregates are dominated by dense hydrogen-bond networks. Full article

In this work, the structural, electronic, charge-transfer, thermal, and magnetic properties of pristine and Fe-doped silicon carbide nanosheets (SiCNShs) were systematically investigated using spin-polarized density functional theory (DFT) within the Local Spin Density Approximation including Hubbard correction (LSDA + U). A 4 × 4 SiCNSh supercell containing 80 atoms was considered, where Fe atoms were substitutionally introduced at carbon sites to evaluate dopant-induced modifications in the nanosheet. Structural optimization, energy convergence, force minimization, and stress evolution analyses confirm that Fe incorporation preserves the structural integrity of the SiCNSh and leads to energetically stable configurations. The calculated defect formation energy (−7.44 eV/atom) demonstrates the thermodynamic feasibility of Fe substitution, while ab initio molecular dynamics (AIMD) simulations at 300 K verify the thermal stability of the energetically favorable Fe-doped configuration. Electronic-structure calculations reveal that pristine SiCNSh exhibits a nonmagnetic semiconducting nature with a band gap of approximately 2.4 eV, whereas Fe incorporation significantly modifies the electronic structure through pronounced Fe–3d/C–2p/Si–3p orbital hybridization. The band gap is reduced to approximately 1.1 eV for the single-Fe-doped system and further decreases to 0.53/0.51 eV (spin-up/spin-down) in the double-Fe configuration, while preserving semiconducting behavior. Spin-polarized band structure and density of states analyses demonstrate clear spin asymmetry near the Fermi level, indicating strong dopant-induced spin polarization and exchange interactions. Charge-density difference and Bader charge analyses reveal substantial dopant-induced charge redistribution characterized by electron depletion around Fe atoms, enhanced electron accumulation on neighboring carbon atoms, and partial charge neutralization of nearby Si atoms, resulting in a more localized covalent Si–C–Fe bonding environment. Mulliken spin population analysis further demonstrates robust ferromagnetic ordering, where the Fe dopant acts as the dominant magnetic center with strong induced spin polarization extending into neighboring Si and C atoms. Comparison between ferromagnetic (FM) and antiferromagnetic (AFM) configurations confirms that the 2Fe@C-doped SiCNSh stabilizes in a ferromagnetic ground state, exhibiting a favorable FM–AFM energy difference of 0.216 eV. Based on the mean-field approximation, the Curie temperature was estimated to be approximately 837 K, indicating strong magnetic stability significantly above room temperature. The present findings collectively demonstrate that Fe incorporation effectively tailors the electronic and magnetic properties of SiCNSh through band-gap engineering, spin-symmetry breaking, and stabilization of high-temperature ferromagnetism. These combined characteristics establish Fe-doped SiCNShs as promising candidates for spintronic devices, magnetic semiconductors, spin injectors, spin filters, and non-volatile magnetic memory applications. Full article

Sponge spicules have emerged as promising biomaterial scaffolds due to their biocompatibility and unique structural properties; however, achieving stable and bioactive functionalization remains a key challenge. The tripeptide GHK is known to promote collagen synthesis and wound repair, yet its therapeutic efficacy is often limited by rapid diffusion and instability. Here, we report ALTUM, a thiol-functionalized sponge spicule composite in which GHK is covalently conjugated via disulfide linkage to enable controlled and redox-responsive peptide delivery. ALTUM exhibited sustained GHK retention under physiological and storage conditions, while exposure to reduced glutathione (GSH) selectively accelerated peptide release through disulfide bond cleavage. This dual release behavior—long-term stability combined with reduction-triggered activation—distinguishes ALTUM from conventional delivery systems. The composite also demonstrated structural stability under thermal, cyclic, and photostability conditions. In an artificial human skin model, ALTUM enhanced dermal penetration of GHK and significantly increased collagen deposition in the dermal layer, demonstrating its capacity to promote collagen production within deeper skin tissue, compared to simple spicule–peptide mixtures. ALTUM was fabricated at an optimized spicule-to-peptide ratio of 3% (w/w), preserving the needle-shaped spicule morphology after surface modification. In vitro, ALTUM exhibited a sustained release profile, with GHK release markedly accelerated in the presence of 10 mM glutathione (GSH) compared with non-reductive conditions, reaching approximately 60% cumulative release over 35 days. In the bioprinted artificial human skin model, ALTUM delivered 9.72 ng/cm² of GHK, more than five-fold higher than the physical mixture of spicules and free GHK (1.9 ng/cm²), and significantly increased type I collagen expression in human dermal fibroblasts. Mechanistically, ALTUM-mediated delivery was associated with increased TGF-β expression and engagement of the SMAD signaling pathway, as indicated by increased phosphorylation of SMAD2/3, consistent with involvement of the TGF-β–SMAD axis in the observed collagen induction. Collectively, these findings establish ALTUM as a structurally stable, redox-responsive dermal delivery platform that enhances collagen synthesis and skin regeneration. Full article

Northern pike (Esox lucius) myofibrillar protein (MP) forms inherently weak gels due to endogenous proteolytic activity and the low thermal stability of fish myosin, limiting its application in surimi products. This study investigated the reinforcing effect and underlying mechanism of rice protein amyloid fibrils (RFs) on pike MP gels. Dynamic rheology revealed that RFs increased both the storage and loss moduli in a concentration-dependent manner, with the 5% group exhibiting an approximately threefold increase in the G′ at 100 rad/s relative to the control. The gel strength, hardness, and chewiness increased progressively with the RF content, whereas the water-holding capacity peaked at 1–3% RFs and declined sharply at 5% RFs. Microstructural imaging showed that moderate RF levels promoted a dense, homogeneous network architecture, while excessive RFs induced phase separation and structural heterogeneity. Hydrophobic interactions and hydrogen bonds were strengthened via RF incorporation, while disulfide bonds decreased monotonically with the increasing fibril concentration. FTIR spectroscopy revealed an α-helix-to-β-sheet transition, with the β-sheet content reaching a maximum of 49.37% at 3% RFs, and SDS-PAGE confirmed that the RF–MP interactions were predominantly non-covalent in nature. These results demonstrate that RFs reinforce pike MP gels through a molecular mechanism involving rigid fibrils acting as structural scaffolds within the protein network and a progressive shift from disulfide-mediated covalent crosslinking toward non-covalent stabilization via hydrophobic interactions and hydrogen bonding. The 1–3% RF range delivers the most balanced gel properties, while excessive fibril loading at 5% induces over-aggregation and impairs water retention. These findings establish amyloid fibrils as effective structural modifiers for freshwater fish gel products and provide a mechanistic basis for their application in surimi processing. Full article

This study examines a series of organic–inorganic crystal structures containing the periodate anion (IO₄⁻) to clarify the nature of the anion–anion interactions that are frequently referred to as halogen bonds. Our analysis demonstrates that, in many cases, IO₄⁻ does not develop an electrophilic σ-hole on the iodine center, even in the presence of organic cations, and therefore cannot reliably function as a halogen-bond donor. In its discrete (0D) form, the anion retains its character as a Lewis base. In crystal structures where extended architectures are observed—such as one-dimensional chains, two-dimensional layers, or three-dimensional cage-like assemblies—these structures arise predominantly from strong coulombic interactions with surrounding cations, as the interaction between the anions is intrinsically repulsive in the gas phase. Hydrogen bonding, together with other noncovalent interactions including chalcogen, tetrel, and/or pnictogen bonding, plays a dominant role in stabilizing the anionic arrangements and governing their structural organization. Full article