Search Results (1,740)

Three multicomponent crystals of metformin were investigated to elucidate factors governing crystal architecture. Structures were determined by X-ray diffraction and analyzed using the Atoms-in-Molecules (AIM) approach, focusing on critical points and electron density topology. Three types of crystals were obtained: salt, cocrystal salt solvate and mixed salt with both organic and inorganic anions. Protonation of nitrogen atoms in metformin alters bond lengths and electron density, while strong intramolecular hydrogen bonds in hydrogenmaleate anions stabilize the structures and define the preferred anion geometry. Comparison with monoprotonated metformin revealed similar topological features despite differing protonation states. Mechanochemical synthesis via liquid-assisted grinding (LAG) enabled selective formation of specific crystalline forms, with the solvent type and acid polymorph influencing product distribution. These results highlight the critical roles of protonation, hydrogen bonding, and synthetic methodology in designing and controlling multicomponent metformin crystal structures. Full article

Development of green and efficient technologies for valorizing crayfish shell waste is crucial for enhancing industrial value. This study presents an integrated strategy for the extraction and structural engineering of chitin using a novel alkaline deep eutectic solvent (DES) system composed of lysine and monoethanolamine (LysMEA), which enables the simultaneous deproteinization and architectural modification of chitin. Following mild demineralization, the optimized process yielded chitin with 97.1% purity and a high molecular weight of 209.3 kDa. DES demonstrated considerable reusability and decolorization capability. Structural characterization revealed that the LysMEA system effectively engineered the chitin architecture, resulting in lower crystallinity and a larger surface area compared to conventional methods. This engineered structure rendered the chitin highly accessible to enzymes. Consequently, the chitin extracted by LysMEA exhibited superior reactivity, achieving a deacetylation degree of 63.7% when catalyzed by Bacillus aryabhattai chitin deacetylase, significantly outperforming chitin obtained via acid-alkali or acidic DES methods. Molecular dynamics simulations elucidated the mechanism, showing that lysine and monoethanolamine molecules penetrated the chitin fiber bundles at high temperatures, weakening interchain hydrogen bonds and partially separating the chains. This work provides a green route for producing enzymatically reactive chitin, demonstrating the potential of solvent-based structural engineering in biocatalytic valorization. Full article

Acinetobacter baumannii (A. baumannii) represents a major threat because of its multidrug resistance, achieved through its ability to control virulence, and its mechanisms of drug efflux resistance. In this study, we used a combined experimental–computational approach to create and evaluate antimicrobial peptides that targeted the two essential pathogenic proteins, BfmR and AbaQ. The genomic analysis of a clinical isolate showed an extensive resistome and virulence profile, which matched high-risk global lineages. This study conducted molecular docking of an experimental AMP (cathelicidin KR-12 screened from the literature) and a rationally designed synthetic AMP (modified KR-12 analog) with pathogenic proteins, followed by 200 ns molecular dynamics simulations to evaluate both the binding stability and inhibitory potential of the compounds. The disk diffusion assay and microdilution assay were performed against A. baumannii. The study used comparative trajectory analyses, including RMSD, RMSF, radius of gyration, solvent-accessible surface area, principal component analysis, and MM-PBSA free energy calculations, to show that the synthetic AMP created stable electrostatic and hydrogen-bond networks, which caused conformational locking, and reached lower energy states than the experimental peptide. The synthetic AMP showed significant inhibition in validation in vitro. Contrastingly, the experimental AMP had transient interactions and no specificity. The study demonstrates that rationally designed AMPs have therapeutic potential, while the results create a reliable in silico framework to combat multidrug-resistant A. baumannii. Full article

The common metabolic disorder, lactose intolerance, is often treated with oral lactase enzyme supplements, which can frequently cause gastrointestinal instability. This work utilizes Malbranchea cinnamomea’s AA9 lytic polysaccharide monooxygenase (LPMO) to target β-lactose (β-lactose) in an investigation of a new enzymatic approach for lactose breakdown. Potential possibilities for lactose breakdown are AA9 LPMOs, copper-dependent enzymes that oxidatively cleave glycosidic bonds in polysaccharides. We employed a combined in silico method that incorporated molecular docking, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations. Docking studies revealed that β-lactose formed hydrogen bonds with key residues SER100, ASN54, and ARG56, exhibiting a greater binding affinity (−5.4 kcal/mol) toward LPMO compared to the control citric acid (−4.9 kcal/mol). Upon DFT analysis, (LPMO) showed excellent stability and appropriate reactivity for enzyme interaction. The higher stability of the LPMO-β-lactose complex was highlighted by MD simulation over 100 ns, which showed lower root mean square deviation (RMSD) and root mean square fluctuation (RMSF) values, greater structural compactness, and reduced solvent accessibility when compared to the control. These collective findings suggest that β-lactose interacts efficiently with the AA9 LPMO active site, supporting its potential as a novel enzymatic target for lactose degradation. This computational study provides a theoretical foundation for developing alternative therapeutic strategies for lactose intolerance, though further in vitro and in vivo investigations are required to validate these findings. Full article

We report a rare family of pyridine-coordinated iodobismuthate(III) salts supported by alkyltriphenylphosphonium and tetraphenylphosphonium cations. Reactions of BiI₃ with Ph₃PR⁺I⁻ (R = Me, Et, ⁿPr, ⁿBu, Ph) in neat pyridine, followed by crystallization, yield structurally tunable bismuth-halide-pyridine anions dictated by reagent stoichiometry. Combination of BiI₃ and Ph₃PR⁺I⁻ in 2:1 ratio produced [Ph₃PR]₂[BiI₅Py], 1 (R = Me, Et, ⁿPr, Ph), while combination in 1:1 ratio resulted in three compounds: [Ph₃PR][cis-BiI₄Py₂], 2 (R = ⁿPr, Ph), [Ph₃PR][trans-BiI₄Py₂], 3 (R = Me, Et, Ph), and [Ph₃PR]₂[transoid-Bi₂I₈Py₂], 4 (R = Me, Et, ⁿPr, ⁿBu, Ph). In many cases, the compounds were isolated as Py or Et₂O solvates, and in some cases, multiple degrees of solvation or polymorphism were encountered. Hirshfeld analysis of 1–4 showed the major anion–cation/anion/solvent interactions to be H⋯I, H⋯H, and C⋯H. Diffuse reflectance measurements of representative compounds, all of which were yellow-orange to red-orange, revealed bandgaps in the range of 1.9–2.2 eV, where density-of-states KS-DFT calculations attribute the absorption to metal-centered charge transfer within the anionic unit. NLMO and QTAIM analyses further indicate predominantly ionic Bi(III)–I/pyridine bonding with robust inner-sphere coordination that is insensitive to anion speciation. Full article

Carbon dioxide emissions from fossil fuel burning remains a severe environmental challenge that needs to be addressed. Deep eutectic solvents (DESs) have emerged as promising alternatives to conventional alkanolamines for CO₂ capture applications due to their lower volatility and reduced corrosion potential. In this work, two tetrabutylammonium bromide (TBAB)-based systems were synthesized using different hydrogen bond donors: 2-amino-2-methyl-1-propanol (AMP) at a 1:1 molar ratio and p-toluenesulfonic acid (PTSA) at a 1:2 molar ratio. FTIR spectroscopic analysis confirmed that TBAB-AMP (1:1) forms a true DES through hydrogen bonding interactions, whereas TBAB-PTSA (1:2) undergoes proton transfer to form an ionic salt. CO₂ solubility measurements were conducted using the pressure drop method up to 15 bar at 30 °C. The TBAB-AMP system exhibited a CO₂ uptake of 0.194 mol CO₂/mol DES at 14.7 bar, approximately 2.5-fold higher than the TBAB-PTSA system, which achieved 0.079 mol/mol at 14.5 bar. Critical and thermophysical properties were estimated using the modified Lydersen–Joback–Reid, Lee–Kesler, and Haghbakhsh group-contribution methods. Viscosity measurements conducted from 30 to 50 °C revealed that TBAB-AMP exhibited significantly lower viscosity, ranging from 163 to 46 mPa·s, compared to TBAB-PTSA, which showed viscosity values between 536 and 155 mPa·s. The superior CO₂ capture performance of the amine-functionalized DES was attributed to favorable hydrogen-bonding interactions, lower viscosity, which enabled better mass transfer, and enhanced chemical affinity toward CO₂ through carbamate formation. Full article

Cellulose fibers offer renewable sourcing and an established recycling infrastructure for food packaging applications. Their hydroxyl groups bind water strongly, which causes dimensional instability and compromises barrier performance at elevated humidity. Chemical modification targets this limitation through controlled changes to hydroxyl reactivity, surface charge, and interfiber hydrogen bonding. This review covers four principal covalent modification routes: esterification, etherification, phosphorylation, and oxidative functionalization. The spatial localization of functional groups—surface-enriched versus bulk modification—is treated as a cross-cutting analytical parameter governing the translation of molecular chemistry into barrier performance, mechanical behavior, and recyclability. We emphasize how molecular parameters (degree of substitution (DS), charge density, and the spatial distribution of functional groups) translate into barrier properties, mechanical performance, and grease resistance under realistic service conditions. Two practical constraints define the design space. Bulk modifications that penetrate the fiber wall can release reagents or by-products into food (non-intentionally added substances, NIASs), whereas surface-confined chemistry reduces this risk substantially. Modifications that resist repulping or introduce persistent contaminants damage recyclability. Life cycle impacts often derive more from processing steps (mechanical fibrillation, solvent use, and multi-stage washing) than from feedstock selection. We focus on three deployment-relevant outcomes: performance retention above 75% relative humidity, migration risk under food contact regulations, and compatibility with industrial fiber recycling. The aim is to identify strategies that can move from laboratory demonstration to production-scale implementation. Full article

Over the past few decades, ionic liquids (ILs) have gained attention as electrolytes, although concerns about their environmental persistence and toxicity challenge their status as green solvents. In this framework, choline chloride (ChCl) offers a more sustainable alternative due to its low toxicity, biodegradability, and cost-effectiveness. Although ChCl has a high melting point, its combination with hydrogen bond donor compounds (HBDs) can result in liquid mixtures at much lower temperatures, known as deep eutectic solvents (DESs). This study presents a comparative evaluation of three ChCl-based DESs, glyceline, ethaline, and reline (obtained from mixtures of ChCl and glycerol, ethylene glycol, and urea), with a focus specifically on their potential as electrolyte candidates for supercapacitors. Using differential scanning calorimetry (DSC), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and nuclear magnetic resonance (NMR), we assess their thermal, electrochemical, and structural properties. All DESs displayed amorphous behavior and a strong tendency to remain liquid even at very low temperatures. Among them, ethaline showed the most promising electrochemical performance, exhibiting the lowest resistivity and the highest capacity. Full article

Zinc-ion batteries have garnered significant research interest owing to their inherent safety, low cost, and environmental compatibility. Nevertheless, their widespread adoption is impeded by critical challenges including uncontrollable dendrite growth, parasitic side reactions stemming from active water molecules, and the corrosion of the zinc anode in conventional aqueous electrolytes. Herein, a hydrated deep eutectic solvent (HDES) electrolyte based on ZnSO₄, MnSO₄, and ethylene is proposed for high-performance zinc-ion batteries. This electrolyte demonstrates excellent stability and simultaneously enables the formation of a protective coating on the Zn anode surface. Spectroscopic analyses and theoretical simulations reveal that this electrolyte reconfigures the primary Zn²⁺ solvation shell by replacing water molecules with HDES components. This tailored solvation structure facilitates interfacial desolvation, elevates nucleation overpotential, and promotes uniform, dendrite-free zinc deposition. Simultaneously, a robust hydrogen bond network effectively sequesters free water, significantly suppressing the hydrogen evolution reaction and anode corrosion. Benefiting from these features, the HDES-based full cell delivers exceptional long-term stability, achieving over 2000 cycles at 3 mA cm⁻² with a capacity retention exceeding 95% and a Coulombic efficiency surpassing 85%. In sharp contrast, the traditional aqueous counterpart fails within only 200 cycles. This tenfold lifespan enhancement, coupled with cost-effectiveness and non-flammability, presents a promising strategy for advanced, grid-scale zinc-based energy storage. Full article

Reproductive management in goats remains challenging due to seasonal breeding and the use of hormones that raise concerns about immunogenicity, cost, sustainability, and animal welfare. In this study, we evaluated date palm pollen (Phoenix dactylifera L.) (DPP) as a natural source of estrogenic compounds capable of modulating reproductive function. DPP was extracted using methanol, ethanol, acetone, and hexane, and the extracts were analyzed by ultra-performance liquid chromatography. Quercetin and coumestrol were detected in the methanolic and ethanolic extracts at comparable levels (quercetin 0.043–0.044 mg/g; coumestrol 0.987–1.015 mg/g of extract) (p > 0.05). The acetone extract contained significantly lower concentrations (quercetin 0.017 mg/g; coumestrol 0.033 mg/g of extract), while the hexane extract showed no detectable amounts. Molecular docking using the crystallographic structure of estrogen receptor alpha (PDB:6PIT) showed that both compounds interact with key residues of the receptor’s ligand-binding domain. Coumestrol exhibited the highest affinity (−9.3 kcal/mol), surpassing 17-β estradiol (−8.9 kcal/mol), forming several hydrogen bonds and hydrophobic contacts. Quercetin showed a lower affinity (−7.2 kcal/mol) but maintained stabilizing interactions compatible with partial agonist activity. Overall, methanol and ethanol were the most effective solvents for extracting phytoestrogens from DPP, and the findings support their potential as natural alternatives to hormones for estrus induction in goats. Full article

Persimmon polyphenols (PP) are natural polyphenols with high reactivity and strong deodorization potential; however, their practical application in odor control is limited by their poor solubility. In this study, natural deep eutectic solvents (NADESs) were employed for the green extraction of PP, and the capabilities of extracts on the removal of ammonia (NH₃) and hydrogen sulfide (H₂S) were investigated. In addition, the underlying mechanisms were explored by integrating spectroscopic analysis, molecular dynamics simulations, and quantum chemical calculations. The results showed that chloride-citric acid (CC-CA) was the optimal system in both PP extraction and sustained NH₃ removal, while the betaine-urea (B-U) system was more effective for H₂S removal. NH₃ removal was governed by acid-base neutralization, with the resulting ammonium species being further stabilized within the PP-regulated NADES hydrogen-bond network. In contrast, H₂S interacted with the solvent network not only through acid-base neutralization but also via Van der Waals forces and hydrophobic contacts. Our data supported that NADESs enhanced the deodorization performance of PP through cooperative microenvironment regulation rather than irreversible chemical conversion. This work highlighted that NADESs could not only function as highly efficient extraction media for polyphenols, but also active platforms for enhancing selective gas-capture capability for polyphenols. Furthermore, it provided a new strategy for the rational design of green, persimmon-derived deodorants. Full article

Deep eutectic solvents (DESs) have emerged as promising green alternatives to conventional organic solvents for the extraction of bioactive compounds from natural matrices because of their tunable physicochemical properties, low toxicity, and environmental compatibility. However, most existing reviews primarily focus on application-based results, with limited mechanistic and process engineering interpretations necessary for industrial applications. This review provides a comprehensive analysis of DES-based extraction from the perspective of separation and process engineering, emphasizing the relationships between DES composition, physicochemical properties, mass-transfer behavior, and extraction performance. Key parameters, including viscosity, hydrogen bonding interactions, solvent-to-feed ratio, temperature, and water content, are critically evaluated in terms of their influence on extraction efficiency, selectivity, and scalability. Furthermore, solvent recovery, process intensification strategies, and industrial implementation challenges are discussed to bridge the gap between laboratory research and large-scale application. By integrating mechanistic insights with process-level considerations, this review provides a systematic framework for the rational design and optimization of DES-based extraction processes as sustainable and scalable-separation technologies. Full article

Under aqueous conditions, transition-metal catalysis offers an attractive platform for greener C–N bond formation by reducing reliance on hazardous organic solvents. Herein, we report a microwave-assisted palladium-catalyzed selective N-arylation of anilines with 2,3-dihalopyridines in water. Systematic optimization revealed that a catalyst system comprising PdCl₂(1,10-phenanthroline)₂ and (±)-BINAP in the presence of K₃PO₄ enables efficient coupling under microwave irradiation. Under the optimized conditions (PdCl₂(1,10-Phenanthroline)₂, 2 mol%; (±)-BINAP, 3 mol%; K₃PO₄, 3.5 equiv; H₂O, 2.5 mL; 150 °C; 30 min), the coupling of aniline with 2,3-dichloropyridine afforded the corresponding aminopyridine product in up to 91% isolated yield. The method was extended to various 2,3-dihalopyridines and substituted anilines, providing moderate to excellent yields with good regioselectivity. Mechanistically, the transformation is consistent with a Pd(0)/Pd(II) catalytic cycle involving oxidative addition, amido complex formation, and reductive elimination. Full article

The Aspen Plus process simulation with techno-economic assessment was used to evaluate the industrial-scale feasibility of enzymatic hydrolysis of corn stover. Choline chloride (ChCl)-based deep eutectic solvents containing lactic acid (LA), formic acid (FA), and acetic acid (AA) as hydrogen bond donors were used to pretreat the corn stover. Optimal pretreatment conditions (140 °C and a solid-to-liquid ratio of 1:30) achieved high levels of lignin (77.3%, 72.9% and 73.5%) and xylan (90.2%, 93.5% and 90.5%) removal for ChCl/LA (1:5), ChCl/FA (1:5) and ChCl/AA (1:5), respectively, while retaining significant levels of glucan (81.3%, 76.2% and 82%). Subsequent enzymatic hydrolysis at 10% substrate loading yielded glucose at 93.7%, 91.2% and 82.7%, respectively. The DES pretreatment and solvent recovery units accounted for 41.9% of capital costs at a solid-to-liquid ratio of 1:30. Increasing the solid-to-liquid ratio to 1:10 reduced total capital investment by 41.6%. Operational costs were heavily influenced by DES solvent consumption (81.2–92.7% of raw material costs). Of the DESs, the ChCl/FA (1:5) pretreatment process offered the best economic performance, achieving a minimum selling price (MSP) of USD 988.2 per ton. Sensitivity analysis identified glucose yield as the most critical cost driver (±20% variation caused a ±25% change in the MSP, followed by DES recycling efficiency. Fluctuations in DES prices had a limited impact (±20% variation caused a change in MSP of only 2.4–3.8%) due to the solvent recycling mechanism. This study demonstrates the potential of DES pretreatment for industrial application through process optimization, solvent recycling and valorization of by-products. Full article

Background/Objectives: Thrombin, a serine protease central to coagulation and platelet activation, remains an important target for the development of safer and more effective antithrombotic agents. Naturally derived pentacyclic triterpenoids, such as betulinic acid and its acetylated derivatives, 3β-acetoxybetulinic acid, exhibit promising antiplatelet aggregation activity in validated in vitro and ex vivo assays; however, the molecular determinants underlying their direct thrombin inhibition remain unexplored. Results: Docking and MM/GBSA analyses revealed that Baa exhibits the strongest binding affinity (ΔG = −29.58 ± 2.97 kcal/mol), exceeding those of Ba (−20.94 ± 5.81 kcal/mol) and Asp (−18.87 ± 4.18 kcal/mol). Baa forms a highly persistent hydrogen bond with Trp96 (95.5% occupancy) and extensive hydrophobic contacts with Trp215, Leu99, Ile174, and Tyr60A residues defining thrombin’s aryl-binding pocket. MD trajectories demonstrated that Baa binding reduced solvent-accessible surface area (SASA) and residue fluctuations, indicating enhanced structural compaction and stability. In contrast, Ba exhibited weaker, transient hydrogen bonding, while Asp bound primarily near the catalytic triad. The triterpenes exhibit limited oral bioavailability, free PAINS alerts, favourable permeability and metabolic stability. Conclusions: Acetylation at C-3 (acetoxy substitution) substantially enhances thrombin binding via cooperative hydrogen bonding and van der Waals stabilisation, explaining the superior experimental inhibitory potency of Baa. These findings provide a mechanistic framework for structure-guided optimisation of triterpenoid-based thrombin inhibitors and support their further experimental development. Methods: In this study, molecular docking, molecular dynamics (MD) simulations (400 ns), and MM/GBSA free energy analyses were employed to elucidate the binding mechanisms of 3β-acetoxybetulinic acid (Baa), betulinic acid (Ba), and aspirin (Asp) within the thrombin receptor active site. The simulations were explicitly grounded in previously reported chromogenic antithrombin assays and platelet aggregation studies and were designed to mechanistically rationalise the experimentally observed inhibitory potency. Full article