ChemistrySelect最新文献

Plasmodium falciparum lysyl-tRNA synthetase (PfLysRS) is an essential enzyme involved in parasite protein biosynthesis. In this study, we aimed to identify and prioritize potential PfLysRS inhibitors. Virtual screening was used for initial screening, followed by density functional theory (DFT) optimization to refine ligand geometries and electronic properties, including HOMO–LUMO characteristics. Redocking analyses confirmed the retention of favorable binding poses with predicted binding affinities ranging from −12.4 to −11.8 kcal/mol relative to the native reference ligand. The top-ranked compounds were further evaluated using long-timescale molecular dynamics simulations (500 ns), which demonstrated stable protein–ligand complexes with limited RMSD and RMSF fluctuations and persistent interaction patterns. MM/GBSA binding free energy calculations indicated favorable predicted binding affinities, with Compound 22401385 showing the most favorable ΔG_total among the evaluated candidates. Principal component analysis (PCA) and free energy landscape (FEL) analyses revealed that the top complexes predominantly occupied stable conformational basins during simulation. Structural convergence analysis of low-energy conformers showed minimal RMSD variation (<2 Å), while QM/MM calculations supported favorable electronic environments within the PfLysRS binding pocket. This study identifies compound 22401385 as a promising antimalarial candidate. The presented computational findings provides a basis for future experimental validation and antimalarial drug discovery efforts.

Bacterial biofilms such as Streptococcus mutans are the primary reason for dental cavities, resulting from acid production that demineralizes tooth enamel. Titanium-based nanocomposites have been developed in this study with enhanced antibacterial properties for dental use. Silver nanoparticles (AgNPs) at varying concentrations were incorporated into titanium oxide (TiO₂) to develop three nanocomposite samples via sintering. The developed nanocomposite samples were characterized for corrosion resistance, surface roughness, and degradability. The findings showed that AgNPs reinforcement did not affect corrosion properties. Besides, the addition of 2 wt.% AgNPs created the protective layer and increased surface roughness from 2.55 to 3.415 µm. Degradation was not observed in artificial saliva or deionized water. Surprisingly, the developed nanocomposite samples showed no antibacterial activity, whereas the precursor mixtures exhibited significant antibacterial effects—99.13% inhibition in sample 1 and 99.99% in samples 2 and 3 against S. mutans. All the samples showed over 95% cell viability in cytotoxicity analysis, which indicates excellent biocompatibility and safety for human use. These findings suggest that while the final composites lacked direct antibacterial function, their precursor forms are highly effective, and all formulations demonstrated strong potential for use in dental and other biomedical implants due to their safety, corrosion resistance, and mechanical properties.

The valorization of invasive plant species offers a valuable and promising strategy to supply sustainable raw materials to meet the socioeconomic needs of communities and industries. This study evaluates the physicochemical characteristics of three plant species—Mariscus cylindristachyus (M. cylindristachyus), Aeschynomene elaphroxylon (A. elaphroxylon), and Phragmites australis (P. australis)—to assess their suitability for applications and, furthermore, their valorization. Chemical analyses show significant holocellulose contents ranging from 52% to 68% for the three species. The cellulose content was estimated at 51.4%, 47.9%, and 53.1%, respectively, for M. cylindristachyus, A. elaphroxylon, and P. australis, indicating strong potential for use in pulp, paper, and papermaking applications. The ash content, determined by thermogravimetric analysis (TGA), was approximately 4.75% across the species and consistent with chemical assay results. Additionally, the levels of extractable compounds make these plants comparable to annual species. Structural characterizations combined with conductometric titrations and TGA confirmed that the extracted cellulosic fractions are of high purity and exhibit good thermal stability. The measured ionic strengths also align with values reported in the literature for similar lignocellulosic species. Overall, the findings suggest that these invasive plants hold promising bio-based resources for papermaking, packaging, and composite materials. Further work should focus on pilot-scale pulping, process optimization, and end-use performance testing to validate industrial feasibility.

In this study, the corrosion behavior of NdFeB magnets coated with Zn from an acidic chloride bath was comprehensively analyzed at tuned coating thicknesses of 5, 8, and 15 µm. The surface morphology, elemental composition, and phase structure of the coatings were examined using scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction. The results revealed dense morphology, high crystallinity, and strong adherence of Zn to the NdFeB surface across all thicknesses. Electrochemical analyses, including potentiodynamic polarization and electrochemical impedance spectroscopy, were conducted to assess corrosion behavior. In particular, the 15 µm thick Zn coated NdFeB exhibited a tenfold reduction in corrosion current density (0.369 × 10⁻⁶ A/cm²) and a tenfold increase in polarization resistance (5857 Ω.cm²), compared to bare NdFeB (7.94 × 10⁻⁶ A/cm²; 548 Ω.cm²) while retaining over 95% of magnetic performance. A comprehensive analysis of corrosion-induced degradation was conducted to further elucidate the role of protective Zn (OH)₂/ZnO barrier layer in the enhanced corrosion resistance of thicker coatings.

Neurological disorders, including neurodegenerative diseases, epilepsy, and psychiatric conditions, pose significant global health challenges, necessitating the continuous search for effective therapeutic agents. Natural products have long served as potential source of bioactive compounds, many of which have been successfully developed into FDA-approved drugs for neurological disorders. Since the discovery of morphine two centuries ago, natural products have continued to serve as the predominant source of novel drugs and scaffolds for treating CNS disorders. This review provides a focused, case-study based review of selected semisynthetic neurological drugs, critically examining the semisynthetic optimization and clinical translation of natural product-derived neurological drugs. By highlighting how targeted chemical modifications have converted complex or suboptimal natural products into successful CNS drugs, the review illustrates both the opportunities and challenges in advancing natural products toward regulatory approval. This review underscores the continuing potential of natural products in drug discovery and inspires future research into novel neurotherapeutics.

The present work introduces a sustainable and economical approach for recycling pharmaceutical waste, specifically expired paracetamol and Disprin, into biologically active copper oxide nanoparticles (CuONPs). The synthesized nanomaterials were examined using FT-IR, XRD, SEM, TEM, and EDS techniques. FT-IR spectra confirmed the presence of Cu–O vibrations at 520 and 540 cm⁻¹, while XRD analysis revealed a monoclinic crystalline phase with high structural stability. EDS analysis verified elemental purity, showing prominent Cu peaks and weight percentages of 73.42% for P-CuONPs and 76.59% for D-CuONPs. DLS measurements indicated moderately polydisperse behavior with Z-average hydrodynamic diameters ranging from 1589.1 to 3786 nm, while negative zeta potential values (−13.3 to −21.2 mV) suggested moderate colloidal stability. Morphological investigations by SEM and TEM showed spherical, uniformly distributed particles with an average size of 20–50 nm. Theoretical calculations and molecular dynamics simulations supported the experimental findings. P-CuONPs effectively inhibited S. aureus 17(±0.3) mm and E. coli 20(±0.4) mm, whereas D-CuONPs showed activity only against E. coli 15(±0.3) mm. Neither type exhibited antifungal effects against C. albicans. Antioxidant assays confirmed strong free radical scavenging properties, with P-CuONPs performing most efficiently with an IC₅₀ value of 45.58 µg/mL. Anti-inflammatory analysis revealed concentration-dependent inhibition, comparable to sodium diclofenac, with P-CuONPs showing superior activity compared to D-CuONPs. Overall, this study highlights an eco-friendly strategy for repurposing expired drugs into CuONPs with significant antimicrobial, antioxidant, and anti-inflammatory potential, offering promising applications in biomedical research.

In silico studies of structural properties, energetics as well as spectral bands are carried out to explore the adsorption processes of freon gases, namely, chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs) on the Si(100)-2 × 1 surface. CFC adsorption over the heterogeneous Si based surface appears endothermic in nature, whereas for HFC adsorption, the process becomes exothermic ($$H = −60.59 kcal/mole, −39.83 kcal/mole, and −47.57 kcal/mole for CH₃F, CH₂F₂, and CHF₃, respectively). On the other hand, Gibbs free energy changes of CFCs and HFCs adsorption reveal endergonic non-spontaneous nature of the former processes (CFC adsorption) and exergonic spontaneous behavior of the latter processes (HFC adsorption) [$$G = −69.60 kcal/mole, −26.89 kcal/mole, and −28.76 kcal/mole for CH₃F, CH₂F₂, and CHF₃, respectively]. In addition, adsorption process of CH₃F over the silicon-based surface reveals lowest activation energy (21.13 kcal/mole, kinetically preferred), most negative $$ (−69.60 kcal/mole, thermodynamically preferred) and most negative binding energy (−40.68 kcal/mole) indicating highly stable adsorbed species. Formation of new bonds as well as lengthening/shortening of the existing bonds are manifested in the infra-red spectral patterns of the reactants and products.

Parallel and Equilibrium Molecular Dynamics and DL_POLY_4 software were employed to predict the relationship between the behavior of ZnO chemical bonds lengths and the phase transition, using correlation function g(r) of Zn─Zn, Zn─O, and O─O pairs. Our system is composed of (5832 atoms of ZnO) rocksalt structure (2916 atoms of Zn²⁺ and 2916 atoms of O²⁻), at a temperature of 300 (K) and under a pressure range of 0–400 (GPa). We have analyzed the lengths of ZnO bonds, the standard error, the standard deviation, the maximum of g(r), and the percentage of the variation of the bonds. The interatomic interactions were modeled by the potential of Buckingham for short-range and Coulomb for long-range interactions. The calculations were performed on the RAVEN Supercomputer of Cardiff University (UK). Our data are mostly in the vicinity of available information of bonds lengths; the rest can be deduced from the phase transition pressure to use it as a new approach for confirming the phase transition. However, the rest of our results remain predictive due to the lack of results at the extended pressures used in this work. These findings can be applied in industrial sectors, geophysics, medicine, and pharmacy, particularly in nanoscale and materials design.

Biodiesel is an alternative fuel to petroleum diesel, made from renewable sources, with hydroesterification being one of the production routes, consisting of a hydrolysis step followed by esterification. Therefore, this work investigated the enzymatic hydrolysis reaction of crambe oil, aiming at the production of free fatty acids, using the lipase Lecitase Ultra (Phospholipase A1), in a reactor operating in batch mode with orbital agitation and also in a reaction with ultrasonic cavitation by the probe, using DCCR to study the effects of the variables temperature (T), water: oil fraction (W:O), and enzyme: substrate fraction (E:S, where S is the total mass of water and oil). The results of the ultrasound planning indicate that the optimal conditions were reached within the limits studied. After 4 h of reaction, the ultrasound probe obtained a fatty acid yield of 57.7% at 40°C, while, for the orbital shaker, the yield was 65.36% in 12 h of reaction at 50°C. A simplified kinetic mathematical model made under the optimal reaction condition was used to describe the reaction kinetics. The use of ultrasound, despite providing lower conversion, proved to be a promising technique, as it reduces reaction time.