Strong Molecular Interactions Research Articles

Investigation of Adsorption and Young’s Modulus of Epoxy Resin–Sand Interfaces Using Molecular Dynamics Simulation

Epoxy resins exhibit outstanding curability, durability, and environmental compatibility, rendering them extensively utilized in the realm of engineering curing. Nevertheless, the current curing mechanism of epoxy-based resins in cohesion with sand remains inadequately elucidated, significantly impeding their applicability within the domain of soil curing. This study employed molecular dynamics simulations to investigate the adsorption behavior of three distinct types of epoxy resins on the sand surface: diglycidyl ether of bisphenol-A epoxy resin (DGEBA), diglycidyl ether 4,4′-dihydroxy diphenyl sulfone (DGEDDS), and aliphatic epoxidation of olefin resin (AEOR). The objective was to gain insights into the interactions between the sand surface and the epoxy resin polymers. The results demonstrated that DGEDDS formed a higher number of hydrogen bonds on the sand surface, leading to stronger intermolecular interactions compared to the other two resins. Furthermore, the mechanical properties of the adsorbed models of the three epoxy resins with sand were found to be relatively similar. This similarity can be attributed to their comparable chemical structures. Finally, analysis of the radius of gyration for the adsorbed epoxy resins revealed that AEOR exhibited a rigid structure due to strong molecular interactions, while DGEDDS displayed a flexible structure owing to weaker interactions.

Design, characterization, and bioactivity evaluation of novel symmetrical N,N'-benzene-1,2-diylbis[1-(2-chloroquinolin-3-yl)methanimine] based metal complexes

This study presents the synthesis and characterization of two novel metal complexes derived from the symmetrical Schiff base N,N'-benzene-1,2-diylbis[1-(2-chloroquinolin-3-yl)methanimine] (OBCQ), coordinated with Nickel(II) (NiOBCQ) and Copper(II) (CuOBCQ). The structural elucidation of these complexes was achieved through a comprehensive suite of analytical techniques, including elemental analysis, UV–visible spectroscopy, mass spectrometry, infrared spectroscopy, magnetic susceptibility, conductivity measurements, and thermal analysis. The data confirm that both NiOBCQ and CuOBCQ adopt octahedral geometries, formulated as [Ni(OBCQ)(H₂O)₂(Cl)₂] and [Cu(OBCQ)(H₂O)₂(Cl)₂], respectively. Density Functional Theory (DFT) calculations were employed to validate the molecular structures and explore the quantum chemical parameters of OBCQ and its metal complexes. Additionally, in vitro assessments of anti-inflammatory and antioxidant activities revealed enhanced bioactivity for the metal complexes compared to the free OBCQ ligand. Molecular docking studies against key proteins (5IKT for Human Cyclooxygenase-2 and 5IJT for Human Peroxiredoxin 2) highlighted strong binding affinities and molecular interactions, suggesting that OBCQ and its metal complexes hold significant promise as novel therapeutic agents with multifaceted biological activities.

Prediction of Successful Amorphous Solid Dispersion Pairs through Liquid State Nuclear Magnetic Resonance.

Amorphous solid dispersions (ASDs) function in part via a "parachute effect", i.e., polymer-enabled prolonged drug supersaturation, presumably through drug-polymer interactions in the liquid state. We aim to expand the utility of liquid state nuclear magnetic resonance (1HNMR) to streamline polymer selection for ASDs. Our hypothesis is that strong molecular interactions between polymer and drug in 1HNMR anticipate reduced precipitation kinetics in supersaturation studies. For three drug-polymer pairs (i.e., etravirine with each HPMC, HPMCAS-M, and PVP-VA), 1HNMR findings were compared to more common supersaturation studies. Drug-polymer interactions were assessed by saturation transfer difference NMR (STD-NMR) and T1 relaxation time. 2D-1H NOESY experiments were also performed. Supersaturation studies involved precipitation inhibition using the solvent-shift methodology. The results from STD-NMR and T1 relaxation time indicate etravirine bound preferably to HPMCAS-M > HPMC ≫ PVP-VA. STD-NMR and T1 relaxation time yielded insight into which fragments of etravirine structure bind with HPMCAS-M and HPMC. The strong interactions from STD-NMR and T1 relaxation time changes indicated that HPMCAS-M and HPMC, but not PVP-VA, are suitable polymers to maintain etravirine supersaturation and inhibit drug precipitation. 2D-1H NOESY results corroborate the findings of STD-NMR and T1 relaxation time, showing that etravirine interacts preferably to HPMCAS-M than to PVP-VA. Supersaturation studies using solvent-shift technique corroborated our hypothesis as predissolved HPMCAS-M and HPMC, but to a less extent PVP-VA, markedly promoted etravirine supersaturation and inhibited drug precipitation. Supersaturation studies agreed with STD-NMR and T1 relaxation time predictions, as HPMC and HPMCAS-M maintained etravirine in solution for longer time than PVP-VA. The results show promise of 1HNMR to streamline polymer selection in a nondestructive and resource sparing fashion for subsequent ASD development.

Hydroxyapatite/Chondroitin Sulphate Nanocomposite Infused with Black Seed Oil for Bone Tissue Applications: Physicochemical Characterizations and In Vitro Screening

AbstractMorbidities associated with natural bone have highlighted the need of advanced bioactive implants for the replacement of damaged bone. Known for their beneficial bioactivity and biocompatibility, Nigella sativa seeds (kalonji/black seed) are traditionally used in many medications. This research focuses on the positive impact of black seed extract on the chondroitin sulfate‐based hydroxyapatite nanocomposite for bone tissue regeneration applications. Novel nanocomposites with varied concentrations of black seed extract (0, 1, 2, and 3 wt%) were fabricated through a coprecipitation approach and analyzed for physicochemical and biological applications. The results of X‐ray diffraction and FTIR spectroscopy revealed that the HCSK3 nanocomposite was successfully developed with appreciably strong molecular interactions among their components. HCSK3 nanocomposite exhibits higher rough surface morphology (Ra −1.13 µm and Rz −4.8 µm), uniform particle distribution (average particle size −9.9 nm), and good thermal stability with total weight loss of 13%. It also provides better nucleation sites for apatite formation and protein adsorption stimulating cell attachment, proliferation, and differentiation. Moreover, HCSK3 nanocomposite showed excellent cell viability, higher ARS/ALP activities, better antibacterial property, and nonhemolytic property (below 3%). Thus, it can be concluded that HCSK3 nanocomposite manifested the highest biocompatibility and negligible cell toxicity. Therefore, it can be employed as an ideal bone implant in the bone tissue restoration phenomenon.

Identification of a Novel HIV‐1 Integrase Strand Transfer Inhibitor: A Synergistic Approach Combining Pharmacophore Modelling and In Vitro Assays

BackgroundAIDS is a highly prevalent and life‐threatening global epidemic that severely compromises the host's immune system, increasing vulnerability to opportunistic diseases. The absence of definitive curative drugs emphasizes the importance and necessity of discovering novel anti‐HIV agents.ObjectiveThis study aims to discover a natural molecular entity that acts as an Integrase strand transfer inhibitor (INSTI) with enhanced potency against HIV.MethodsA ligand‐based pharmacophore model was developed for 4 FDA‐approved INSTIs, with the potential for treating HIV‐1. AutoDock facilitated molecular docking and free energy calculation to discern IN activity. Subsequently, MD simulations assessed interaction stability. ADMET analysis preceded an in vitro anti‐HIV strand transfer assay.ResultsThe generated model revealed a specific interaction involving Mg2+ ion chelation. Crucial residues of HIV‐1 IN and their respective free‐binding energies were identified. The lead compound exhibited superior in silico characteristics which were substantiated by 100 ns MD simulations and MM‐PBSA analysis. Additionally, the in vitro assay demonstrated potent inhibition with the lowest IC50, forming strong molecular interactions with IN.ConclusionThese findings showed valuable insights for the strategic development of new antiretroviral treatments (ART), paving the path for the development of natural therapeutic agents for HIV treatment.

Computational and theoretical insights into the cytotoxic prospects of compounds isolated from Elaeodendron buchananii against Leukemia

The present study investigated the cytotoxic prospects of isolated compounds from Elaeodendron buchananii against leukemia, using computational tools. Comprehensive literature searches revealed only buchaninoside, mutangin, methyl 3β-acetoxy-11α, 19α, 28-trihydroxyurs-12-en-23-oic acid, 3β, 11α, 19α-trihydroxyurs-12-en-23, 28-dioic acid, 3β-acetoxy-19α, 24, 28-trihydroxyurs-12-ene, 3-oxo-19α,28-dihydroxyurs-12-en-24-oic acid, and elabunin have been isolated from E. buchananii. The compounds were subjected to Density Functional Theory (DFT) and Molecular Dynamics (MD) analyses, with Fms-like tyrosine kinase (FLT3) and catalytic binding sites of Murine Leukemia Virus (MLV) as the target proteins in lukemia. Following DFT analysis, the structures of the compounds were optimized at the PW6B95D3/Def2-TZVP level of theory; their UV-Visible peaks were in the UV region, with mutangin, 3-oxo-19α,28-dihydroxyurs-12-en-24-oic acid and elabunin exhibiting one single peak. The potent Root-Mean-Square Deviation, Root-Mean-Square Fluctuation, solvent-accessible surface area and radius of gyration values indicated a strong and stable molecular interaction between the compounds and the proteins. These were further supported by high ∆G values, with MLV showing the best interaction. Per-residue decomposition plots also revealed high energy contributions in the interactions’ binding sites residues. These results indicate that the cytotoxic prospects of the isolated compounds against leukemia as indicated by its molecular interactions with FLT3 and MLV.

Engineering the plasmonic activities of copper nanostructures for SERS and photocatalysis

Nanoparticles of plasmonic metals such as gold (Au), silver (Ag) and copper (Cu) have numerous applications due to their localized surface plasmon resonance. Among these, nanoparticles of Cu remain underexplored when compared to Au and Ag, although the former is much cheaper. Here we report the surface enhanced Raman spectroscopy (SERS), interaction of molecule with a plasmonics and photocatalysis applications of Cu nanostructures. Hexagonal and cubic shaped Cu nanostructures were successfully synthesized by varying the reaction conditions in a polyol synthesis method. Rapid nucleation at an elevated temperature (140 °C) and subsequent slow growth at lower temperature (80 °C) in presence of polymeric stabilizer resulted in the formation of uniform cube shaped Cu nanoparticles (Cucube). Whereas polyol synthesis at a low temperature (80 °C) resulted in hexagonal Cu nanoparticles (Cuhex). Both the nanostructures exhibited very good surface enhanced Raman scattering (SERS) enhancement of the order 6.9 × 105 for rhodamine B (RhB). Cuhex also showed reliable SERS sensing of RhB with a very low experimental limit of detection (10−10 M). Moreover, based on emission and time-dependent measurements, strong molecular and plasmonic interactions reveal energy transfer from RhB molecules to the Cu nanostructures. Additionally, Cuhex showed very good catalytic and visible light plasmonic photocatalytic activities for the para-nitrophenol (p-NP) reduction reaction.

Tilted Spins in Chains of Molecular Switches on Pb(100).

A complex based on a Ni(II) porphyrin exhibiting spin crossover on Ag(111) is studied on Pb(100) by scanning tunneling microscopy at 0.3 K. Strong molecular interactions between the phenyl and pentafluorophenyl moieties lead to the formation of molecular chains and cause a faceting of the substrate surface. The chains are located along double and multiple substrate steps that deviate from high-symmetry directions. Tunneling spectroscopy reveals spin-flip excitations of an S = 1 system. Measurements in high magnetic fields are used to identify a tilt of the complex and its hard anisotropy axis with respect to the surface normal. Electron injection into the substrate near the molecular rows induces a transition to a state with larger inelastic cross section, leaving the spin state unchanged.

Diabetic wound healing potentials of phenylethanoid glycosides from Clerodendrum glandulosum Lindl.: Connecting the dots by integrating network pharmacology, molecular docking, and molecular dynamics simulation

The diabetic wound is one of the severe complications of diabetes mellitus, accounting for 20 % of limb amputations in diabetic patients. This creates a need to search for newer natural compounds to target the different molecular pathways of diabetic wounds to accelerate the repair. The phenylethanoid glycosides (PhGs) isolated from Clerodendrum glandulosum (CG) have been shown to exhibit antioxidant, antimicrobial, and anti-inflammatory properties but have never been explored for diabetic wound healing. Thus, this study focuses on exploring the diabetic wound-repairing properties of PhGs through in-silico approaches. The PhGs present in CG were identified through extensive literature searching, which were further subjected to database searching in BindingDB, TargetNet, PharmMapper, Super-PRED, and Swiss Target Prediction to find the potential targets, which included PRKCA, PRKCG, PRKCZ, TDP1, and Pol. Subsequently, these targets were used to determine the disease IDs related to diabetic wounds from databases such as DisGeNET, Gene Expression Omnibus, GeneCards, and OMIM. A network was established using Cytoscape to study the relationship among the PhGs, the protein targets, and their associated disease IDs. The top twenty molecular pathways associated with the target proteins were determined using the ShinyGO database. Genetic enrichment analysis showed that the Sphingolipid signalling pathway included the maximum number of genes and had the lowest false discovery rate value, which concluded that this pathway is the potential target of the PhGs. PRKCA and PRKCZ were found to be the only two genes involved in this pathway, and thus, molecular docking was used to evaluate the binding affinity of the PhGs with the proteins. Docking scores were between -13.2859 and -5.10928, suggesting a strong molecular interaction between the PhGs and their targets. Thus, it is concluded that PhGs present in CG can be the potential compounds to treat diabetic wounds; however, further in-vitro and in-vivo investigations are necessary.

Studies on interactions of L-glutamic acid with L-arabinose/D-xylose in aqueous medium: Ultrasonic velocity and acoustic parameter studies supported by FTIR spectroscopic investigation

Glutamic acid is a non-essential amino acid, meaning that the body can synthesize it on its own, and it doesn’t necessarily need to be obtained from the diet. Using an ultrasonic interferometer, the ultrasonic velocity at 293.15 K and 298.15 K and at experimental pressure P = 101 kPa were determined in order to evaluate and comprehend the synergy between non-essential amino acid and saccharides (L-arabinose/D-xylose) in an aqueous system. There is a direct correlation between the weak and strong molecular interactions that occur between the solution’s constituents and the propagation of ultrasonic sound waves through the experimental solutions. Using the ultrasonic velocity data, isentropic compressibility (Ks) apparent molar isentropic compressibility (Ks,ϕ) and isothermal compressibility (KT) were calculated. In addition to these characteristics, acoustic impedance (Z), internal pressure (πi), relative association (RA), molar free volume (Vf), molar free length (Lf) and surface tension (γ) were deduced and analysed to advocates potent ion- solvent interactions. In order to gain understanding of Glu-Glu and Glu- L-arabinose/D-xylose interactions in aqueous medium, these parameters were interpreted. Ion-solvent interactions are stronger than ion-ion interactions due to the greater and positive values of Ks0. Strong contacts occur between the polar segments of L-arabinose/D-xylose and the zwitterionic groups of Glu, and these interactions become stronger as the concentration of L-arabinose/D-xylose increases, as indicated by positive values of Ks,ϕ,tr0. The water structure is reformed during the solvation and ion association processes of Glu. Furthermore, the spectroscopic investigation has been conducted using the FTIR technique in order to verify the results obtained from acoustic studies. Predominant ion-hydrophilic/hydrophobic interactions prevail in the studied system is validated by FTIR study. Absorption band widening indicates that intermolecular hydrogen bonding predominates over intramolecular hydrogen bonding.

The Key to MOF Membrane Fabrication and Application: the Trade-off between Crystallization and Film Formation.

Metal-organic frameworks (MOFs), owing the merits of ordered and tailored channel structures in the burgeoning crystalline porous materials, have demonstrated significant promise in construction of high-performance separation membranes. However, precisely because this crystal structure with strong molecular interaction in their lattice provides robust structural integrity and resistance to chemical and thermal degradation, crystalline MOFs typically exhibit insolubility, infusibility, stiffness and brittleness, and therefore their membrane-processing properties are far inferior to the flexible amorphous polymers and hinder their subsequent storage, transportation, and utilization. Hence, focusing on film-formation and crystallization is the foundation for exploring the fabrication and application of MOF membranes. In this review, the film-forming properties of crystalline MOFs are fundamentally analyzed from their inherent characteristics and compared with those of amorphous polymers, influencing factors of polycrystalline MOF membrane formation are summarized, the trade-off relationship between crystallization and membrane formation is discussed, and the strategy solving the film formation of crystalline MOFs in recent years are systematically reviewed, in anticipation of realizing the goal of preparing crystalline membranes with optimized processability and excellent performance.

WTAP and m6A-modified circRNAs modulation during stress response in acute myeloid leukemia progenitor cells

N6-methyladenosine (m6A) is one of the most prevalent and conserved RNA modifications. It controls several biological processes, including the biogenesis and function of circular RNAs (circRNAs), which are a class of covalently closed-single stranded RNAs. Several studies have revealed that proteotoxic stress response induction could be a relevant anticancer therapy in Acute Myeloid Leukemia (AML). Furthermore, a strong molecular interaction between the m6A mRNA modification factors and the suppression of the proteotoxic stress response has emerged. Since the proteasome inhibition leading to the imbalance in protein homeostasis is strictly linked to the stress response induction, we investigated the role of Bortezomib (Btz) on m6A regulation and in particular its impact on the modulation of m6A-modified circRNAs expression. Here, we show that treating AML cells with Btz downregulated the expression of the m6A regulator WTAP at translational level, mainly because of increased oxidative stress. Indeed, Btz treatment promoted oxidative stress, with ROS generation and HMOX-1 activation and administration of the reducing agent N-acetylcysteine restored WTAP expression. Additionally, we identified m6A-modified circRNAs modulated by Btz treatment, including circHIPK3, which is implicated in protein folding and oxidative stress regulation. These results highlight the intricate molecular networks involved in oxidative and ER stress induction in AML cells following proteotoxic stress response, laying the groundwork for future therapeutic strategies targeting these pathways.

Cellulose-based eutectogel electrolyte with high ionic conductivity for solid-state lithium-ion batteries

It is known that the low ionic conductivity of solid-state polymer electrolytes at room temperature (RT) has severely restricted their practical application in lithium-ion batteries. Although eutectogel (ETG) electrolytes could solve this problem to some extent, highly compatible deep eutectic solvent (DES)/polymer systems are desirable to further enhance ion conduction. Herein, we designed cellulose-based ETG (CETG) with dual channels through “hopping” and “vehicle” mechanisms by hydroxyethyl cellulose (HEC) molecular chains and N-methylacetamide (NMA)/LiTFSI-derived DES, respectively. Thanks to the strong molecular interactions between HEC and DES, the highest DES content in the ETG could achieve 90 %, which endowed the CETG with an excellent ionic conductivity of 2.04 × 10–3 S cm−1 at 30 °C. Additionally, our designed CETG displayed good self-healing and fire retardant properties. The assembled Li/LiFePO4 cell showed a capacity retention of 91.8 % after 200 cycles at 0.2 C under RT with an initial discharge capacity of 156.2 mAh g−1. In particular, the capacity retention rates of the assembled batteries reached 95.2 % and 92.1 %, respectively, after 100 cycles at 0.2 C under 60 °C and 50 cycles at 0.2 C under 100 °C. Our fabrication strategy would provide a novel idea for the design of green, safe and efficient solid-state polymer electrolytes for lithium-ion batteries.

Utilizing the allyl-terminated copolymer methoxy(poly(ethylene glycol))-block-poly(jasmine lactone) in the development of amorphous solid dispersions: A comparative study of functionalized and non-functionalized polymer

Molecular interactions are crucial to stabilize amorphous drugs in amorphous solid dispersions (ASDs). Most polymers, however, have only a limited ability to form strong molecular interactions with drugs. Polymers tailored to fit the physicochemical properties of the drug molecule to be incorporated, for instance by allowing the incorporation of specific functional groups, would be highly sought-for in this regard. For this purpose, the novel allyl-terminated polymer methoxy(polyethylene glycol)-block-poly(jasmine lactone) (mPEG-b-PJL) has been synthesized and functionalized to potentially enhance specific drug-polymer interactions. This study investigated the use of mPEG-b-PJL in ASDs, using carvedilol (CAR), a weakly basic model drug. The findings revealed that the acidic functionalized form of the polymer (mPEG-b-PJL-COOH) indeed established stronger molecular interactions with CAR compared to its non-functionalized counterpart mPEG-b-PJL. Evaluations on polymer effectiveness in forming ASDs demonstrated that mPEG-b-PJL-COOH outperformed its non-functionalized counterpart in miscibility, drug loading ability, and stability, inferred from reduced molecular mobility. However, dissolution tests indicated that ASDs with mPEG-b-PJL-COOH did not significantly improve the dissolution behaviour compared to amorphous CAR alone, despite potential solubility enhancement through micelle formation. Overall, this study confirms the potential of functionalized polymers in ASD formulations, while the challenge of improving dissolution performance in these ASDs remains an area of further development.

Fluorinated molecular diamond improved polymer electrolytes enable stable cycling with high capacity of all-solid-state lithium-metal batteries

The interfacial incompatibility of the poly (ethylene oxide)-based electrolytes hinder the longevity and further practice of all-solid-state batteries. Herein, we present a productive additive 1-Fluoroadamantane facilitating to the distinct performance of the poly (ethylene oxide)-based electrolytes. Attributed to the strong molecular interaction, the coordination of the Li+-EO is reduced and the ‘bonding effect’ of anion is improved. Thus, the Li + conductivity is promoted and the electrochemical window is widened. The diamond building block C10H15− strengthens the stability of the solid polymer electrolytes. Importantly, the 1-Fluoroadamantane mediates the generation of LiF in the interfaces, which fosters the interfacial stability, contributing to the long-term cycling. Hence, the symmetric cell (Li/Li) exhibits a long-term lithium plating/stripping for over 2,400 h. The 4.3 V LiNi0.8Mn0.1Co0.1O2/Li all-solid-state battery with the 1-Fluoroadamantane-poly (ethylene oxide) improved electrolyte delivers 600 times, with an impressive capacity retention of 84%. Also, the cell presents high capacity of 210 mA·h/g, and 170 mA·h/g at 0.1 C and 0.3 C respectively, rivalling the liquid electrolytes.

One-Pot Biopreparation of Trimetallic ZnO–MgO–CuO Nanoparticles: Enhanced Cytotoxicity, Antibacterial Activities and Molecular Docking Studies

Nowadays, metal oxide nanoparticles (MO NPs) are powerful tools for biological applications due to their distinctive features. Moreover, the biological efficacy of multimetallic NPs is more fascinating because of their structural modifications and synergistic effects. This study utilized the one-pot green route to fabricate trimetallic ZnO-MgO-CuO (ZMC) NPs employing a greener reducing agent from Artemisiaabyssinica leaf extract (AALE). The crystal structure, size, compositions, shapes, and external topology of ZMC NPs were characterized by Fourier transform infrared (FTIR), UV–Visible (UV–vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy combined with selected area electron diffraction (TEM/HRTEM-SAED). The outcomes suggested that the bio-prepared ZMC NPs are highly crystalline and have hexagonal structures lattice with monoclinic symmetry and spherical morphology with average crystalline and particle sizes of 14.67 and 15.13 nm, respectively. Using MTT assay, the bio-prepared ZMC NPs demonstrated high inhibition percentage (94.37 ± 0.14 at 250 mg/mL) with an IC50 value of 24.83 mg/mL for MCF-7 cell lines. The in-vitro antibacterial potential of ZMC NPs has been evaluated against four bacterial (Gram-positive and Gram-negative) strains and has demonstrated the highest inhibition zone (35 ± 0.03 mm) against the S. aureus strain and the lowest inhibition zone (31 ± 0.11) against the E. coli strain. Moreover, ZMC NPs have also shown strong molecular binding interactions with amino acids of estrogen receptor (ERα), S. aureus, and E. coli with binding energies of − 9.85, − 12.31, and − 6.04 kcal/mole, respectively.Graphical

Characterization and insight mechanism of an acid-adapted β-Glucosidase from Lactobacillus paracasei and its application in bioconversion of glycosides

Introduction: β-glucosidase is one class of pivotal glycosylhydrolase enzyme that can cleavage glucosidic bonds and transfer glycosyl group between the oxygen nucleophiles. Lactobacillus is the most abundant bacteria in the human gut. Identification and characterization of new β-glucosidases from Lactobacillus are meaningful for food or drug industry.Method: Herein, an acid-adapted β-glucosidase (LpBgla) was cloned and characterized from Lactobacillus paracasei. And the insight acid-adapted mechanism of LpBgla was investigated using molecular dynamics simulations.Results and Discussion: The recombinant LpBgla exhibited maximal activity at temperature of 30°C and pH 5.5, and the enzymatic activity was inhibited by Cu2+, Mn2+, Zn2+, Fe2+, Fe3+ and EDTA. The LpBgla showed a more stable structure, wider substrate-binding pocket and channel aisle, more hydrogen bonds and stronger molecular interaction with the substrate at pH 5.5 than pH 7.5. Five residues including Asp45, Leu60, Arg120, Lys153 and Arg164 might play a critical role in the acid-adapted mechanism of LpBgla. Moreover, LpBgla showed a broad substrate specificity and potential application in the bioconversion of glycosides, especially towards the arbutin. Our study greatly benefits for the development novel β-glucosidases from Lactobacillus, and for the biosynthesis of aglycones.

Experimental and density functional theory studies on some metal oxides and the derived nanoclusters: a comparative effects on human ferritin

A comprehensive investigation into the green synthesis of metal oxide nanoparticles (NPs) has garnered significant attention due to its commendable reliability, sustainability, and environmentally friendly attributes. Green synthesis methods play a crucial role in mitigating the adverse effects associated with conventional approaches employed for nanostructure preparation. This research endeavors to examine the impact of ginger plant extract-assisted green synthesis of metal oxides NPs on the serum ferritin levels of anemic diabetic patients in vitro, focusing specifically on α-Fe2O3 and ZnO NPs. Sixty diabetic volunteers with anemia (35–50 years) and thirty healthy volunteers were enrolled as controls. The assessment was conducted using the VIDAS Ferritin (FER) assay. Photoluminescence (PL) spectroscopy measurements were performed to elucidate the intrinsic and extrinsic transitions of these NPs, affirming the successful formation of α-structured iron oxide. Density functional theory (DFT) calculations were carried out at the B3LYP/6-311++G(d,2p) level of theory to investigate the geometry optimization and molecular electrostatic potential maps of the NPs. Furthermore, TD-DFT calculations were employed to explore their frontier molecular orbitals and various quantum chemical parameters. The binding affinity and interaction types of ZnO and α-Fe2O3 NPs to the active site of the human H-Chain Ferritin (PDB ID: 2FHA) target were determined with the help of molecular docking. Results unveiled the crystalline structure of ZnO and the α-structure of α-Fe2O3. Analysis of the frontier molecular orbitals and dipole moment values demonstrated that ZnO (total dipole moment (D) = 5.80 µ) exhibited superior chemical reactivity, biological activity, and stronger molecular interactions with diverse force fields compared to α-Fe2O3 (D = 2.65 µ). Molecular docking of the metal oxides NPs with human H-chain ferritin provided evidence of robust hydrogen bond interactions and metal-acceptor bonds between the metal oxides and the target protein. This finding could have a great impact on using metal oxides NPs-ferritin as a therapeutic protein, however, further studies on their toxicity are required.Graphical abstract

Triple-Mechanism Enhanced Flexible SiO2 Nanofiber Composite Hydrogel with High Stiffness and Toughness for Cartilaginous Ligaments.

Hydrogels are widely used in tissue engineering, soft robotics and wearable electronics. However, it is difficult to achieve both the required toughness and stiffness, which severely hampers their application as load-bearing materials. This study presents a strategy to develop a hard and tough composite hydrogel. Herein, flexible SiO2 nanofibers (SNF) are dispersed homogeneously in a polyvinyl alcohol (PVA) matrix using the synergistic effect of freeze-drying and annealing through the phase separation, the modulation of macromolecular chain movement and the promotion of macromolecular crystallization. When the stress is applied, the strong molecular interaction between PVA and SNF effectively disperses the load damage to the substrate. Freeze-dried and annealed-flexible SiO2 nanofibers/polyvinyl alcohol (FDA-SNF/PVA) reaches a preferred balance between enhanced stiffness (13.71 ± 0.28MPa) and toughness (9.9 ± 0.4MJ m-3). Besides, FDA-SNF/PVA hydrogel has a high tensile strength of 7.84 ± 0.10MPa, super elasticity (no plastic deformation under 100 cycles of stretching), fast deformation recovery ability and excellent mechanical properties that are superior to the other tough PVA hydrogels, providing an effective way to optimize the mechanical properties of hydrogels for potential applications in artificial tendons and ligaments.

Solubility of fructose and sucrose in mixtures of methanol and water: Experiment and application of equations of state and activity coefficient model

Beyond biochemical functions, carbohydrates have great industrial and economic importance. To improve industrial processes and to develop new applications for these substances, the knowledge of their solubility behavior in different solutions is often necessary. Therefore, the purpose of this work was to collect experimental data on the solubility of fructose and sucrose in hydroalcoholic solutions of methanol and water, using a chromatographic method. The solubility was evaluated for the entire mole fractions of the binary mixture covering the temperatures from 298.15 K to 323.15 K. The results indicated that the chromatographic method is suitable for determining sugar concentration, but it implies an increased uncertainty over the results. The solubility of both sugars was low in methanol-rich binary mixtures, rising with the increasing proportion of water. Greater dependence of the solubility as a function of the composition of the binary mixture was observed for sucrose, indicating stronger molecular interaction and therefore greater deviation from ideality. The NRTL activity coefficient model and the PC-SAFT and CPA equations of state were successfully employed to correlate the solid-liquid equilibrium. The binary interaction parameters were optimized as a function of temperature. The NRTL model has shown greater deviations than those presented by the equations of state. Meanwhile, the equations of state have presented a similar performance.