Chemical Papers最新文献

Oil pollution poses severe threats to aquatic and terrestrial ecosystems, necessitating sustainable remediation strategies. The potential of Bacillus subtilis, which was isolated from tomato rhizosphere soil, for oil bioremediation and biosurfactant synthesis was examined in this work. The isolate was characterized through Gram staining, Plating in Bacillus Differentiation Agar, and Biochemical tests, confirming its identity as Bacillus subtilis. Screening assays, including hemolytic activity, oil displacement (74 mm clearance zone), emulsification (E24 index: 76.6%), and drop collapse tests, demonstrated robust surfactin production. GC–MS analysis identified (13Z)-13-Docosenamide as a key bioactive compound, contributing to hydrocarbon degradation. For bioremediation, oil-contaminated wastewater samples (gasoline, crude oil, kerosene and diesel) were treated with surfactin and monitored over four weeks. Optical density (OD) measurements revealed progressive oil degradation, with crude oil (WWS-2) showing the highest efficiency (OD reduction to 0.23). The study also formulated a powder-based biodetergent using surfactin (25–60%), Sapindus mukorossi (1% foaming agent), and a stabilizer (1.5%), demonstrating its applicability for industrial and household use. The findings highlight Bacillus subtilis as a promising candidate for eco-friendly oil spill remediation and biosurfactant-based product development.

Dihydropyrimidin-2(1H)-ones (DHPMs) have garnered significant attention in synthetic and medicinal organic chemistry because of their remarkable biological and therapeutic potential. In this study, DHPM derivatives were synthesized using the Biginelli reaction starting from bisdialdehyde to identify potential lead compounds. The predicted lipophilicity values of the synthesized DHPMs were in the range 2.77- 4.3. Log Po/w indicates the drug-likeness properties of the synthesized compounds. Structural confirmation was achieved through advanced spectroscopic techniques. DHPMs 7 and 9 demonstrated strong antimicrobial activity, effectively targeting a wide range of microbes. Molecular modeling further revealed that DHPM 9 exhibited a notable docking score of -8.161 kcal/mol, indicating a high binding affinity for VEGFR-2 kinase. According to HOMO and LUMO studies, DHPM 1 is the most stable of the DHPMs (ΔE = 4.838 eV), while DHPM 9 is the most reactive with the smallest energy gap (ΔE = 3.677 eV). The anticancer potentials of synthesized were evaluated using A549 lung cancer cell. The work highlights significant cytotoxic effects on A549 cells with IC50 values of 1.56 μg/mL. The genotoxicity assay is performed using agarose gel electrophoresis, which is an appropriate method for assessing mutagenic potential. The results indicate that compound 7 exhibits moderate genotoxic potential at 125 μg /ml. DHPM 9 exhibits strong activity against Enterococcus faecalis, with an MIC range of 6.30 μg/mL, and is chemically more reactive than the other compounds, which is consistent with the strongest anticancer and antimicrobial activity values. DHPMs 7 and 9 stood out with the highest cumulative release percentages at the final time point (68.54–74.85%), showcasing their efficient delivery capabilities. The research aims to contribute to public health by evaluating the biological effects and therapeutic potentials of the synthesized compounds.

Graphical abstract

This study introduces an innovative electroosmotic micromixer that features circular mixing chambers connected by intersecting microchannels. To evaluate its performance, three-dimensional simulations are carried out using a direct current (DC) electric field generated by two electrodes positioned above the circular chambers. Additionally, two-dimensional simulations utilize an alternating current (AC) electric field applied through semi-circular electrodes. The main goal of the research is to assess how mixing efficiency (ME) and pressure drop (Δp) are influenced by variables including DC and AC voltage, AC frequency, and the inlet flow rate. The effectiveness of the DC–powered micromixer is assessed by calculating the performance evaluation criterion (PEC). Results from the 3D DC-driven simulations indicate that ME increases with higher DC voltage but decreases with rising Reynolds number (Re). PEC values for the DC-driven micromixer range from 0.232 to 70.92, demonstrating a highly efficient design. In the AC-driven micromixer, no clear trend is observed between ME and changes in inlet velocity; however, ME improves with increased voltage and diminishes as frequency rises.

Tunisian date seed (TDS) powder was selected as a bioadsorbent material for eliminating Alizarin Red S (ARS) from wastewater. The Box–Behnken design (BBD) response surface methodology (RSM) was used to analyze various factors, including ARS concentration, pH, and adsorbent mass, to optimize the adsorption process. The resulting model proved highly effective in determining the optimal conditions for ARS removal, achieving a maximum adsorption capacity of 24.57 mg g⁻¹. The use of TDS as an adsorbent demonstrated excellent efficiency in treating wastewater containing high concentrations of ARS. Thermodynamic analysis revealed that the adsorption process is non-spontaneous, exothermic, and occurs in an organized manner. Additionally, several kinetic models were evaluated to determine the adsorption kinetics, with the pseudo-second-order model showing the best correlation with experimental data. For thermodynamic modeling, various isotherm models were tested, and the Langmuir–Freundlich model was identified as the most suitable for accurately describing the experimental isotherms. The optimal conditions determined using response surface methodology (RSM) were pH = 6.14, ARS concentration of 200 mg L⁻¹, and adsorbent mass of 0.21 g.

The study focused on optimizing the extraction of anti-thrombin phenolics and flavonoids from the stem and flower of Justicia adhatoda (JA) using response surface methodology (RSM). Key factors utilized for the optimization included HCl concentration (0.1–1 N), extract concentration (50–150 mg/mL), methanol proportion (0–100%), and incubation temperature (32 ± 2 °C for hot and 6 ± 2 °C for cold). Fluorescence microscopy identified plant parts enriched with pharmacologically active compounds. The optimized extracts demonstrated substantial levels of phenolics, flavonoids and thrombin inhibitory activity across all samples. Antioxidant activity was measured using the DPPH and ABTS radical scavenging assays. Furthermore, multivariate optimization enhanced the antioxidant properties of the extracts. LC–MS analysis of the optimized extracts from JA (stem and flower) identified the presence of 22 compounds, with anti-thrombin polyphenols and flavonoids predominating, constituting approximately 30% and 35%, respectively. In silico studies, including molecular docking and dynamic simulations, revealed that the flavonoid Naringenin (−4.868 kcal mol⁻¹) had a higher inhibitory potential against the thrombin protein compared to the reference drug Dabigatran (−4.269 kcal mol⁻¹). This study demonstrated that flavonoids with significant anti-thrombin activity can be effectively extracted from J. adhatoda stem and flower using this optimized extraction procedure.

Magnesium ion batteries (MgIBs) are regarded crucial in meeting the energy demands of the future, and computational simulations have the potential to significantly expedite the search for improved technologies. The material features of the electrodes are key factors in ensuring the efficient performance of MgIBs. Within this piece of research, the viability of utilizing the two-dimensional AlB monolayer (AlBML) as the electrode material for Mg ions was investigated through first-principles calculations. The findings revealed that the storage capacity of AlBML for Mg ions surpasses that a lot of previously fabricated negative electrodes, reaching approximately 795.26 mAh g⁻¹. Moreover, the migration barriers for Mg ions within the AlBML were calculated to be 0.114 eV, indicating the potential for rapid charging and discharging. These results suggest that AlBML could serve as a promising cathode material for MgIBs, warranting further theoretical and experimental exploration.

Hydroxymethylfurfural (HMF) is a pivotal renewable platform chemical for synthesizing high-value derivatives. While the production of HMF from biomass has garnered significant interest, optimizing the trade-offs among production costs, energy efficiency, and environmental impact remains a critical challenge. The catalytic conversion of glucose to HMF using carbon-based solid acid catalysts offers a sustainable and efficient route for producing this strategic platform molecule. In this study, a novel catalyst, C (Cr, Cl, S), was synthesized via sulfonation of co-carbonized starch and polyvinyl chloride (PVC) in the presence of chromium (III) chloride (CrCl₃). The catalyst features both Brønsted acid (–SO₃H) and Lewis acid (Cr³⁺) sites, which synergistically promote glucose isomerization to fructose and subsequent fructose dehydration to HMF. Notably, the –Cl groups enhance glucose adsorption by strongly interacting with its –OH groups, thereby stretching the carbon framework and reducing steric hindrance between the substrate and catalyst. The C (Cr, Cl, S) catalyst was thoroughly characterized by XPS, FE-SEM, EDS, and FT-IR. XPS analysis confirmed the presence of key functional groups, with binding energies at C 1s (284.6 eV), O 1s (532.1 eV), Cl 2p (200.1 eV), Cr 2p (575.5 eV), and S 2p (168.4 eV), corresponding to Lewis acid sites (Cr³⁺), Brønsted acid sites (–SO₃H), and binding sites (–Cl). EDX quantification revealed elemental compositions of Cr (7.47%), Cl (3.30%), and S (5.11%). Under optimized conditions, the catalyst achieved an exceptional HMF yield of 88% (quantified by UV–Vis spectroscopy), demonstrating its potential for scalable biomass conversion.

Graphical abstract

The conversion of glucose to HMF using the C (Cr, Cl, S) multifunctional solid catalyst involves two active sites: the Lewis acid site (Cr cation) facilitates the isomerization of glucose to fructose, while the Brønsted acid site (SO₃H group) promotes the dehydration of fructose to HMF. Additionally, the –Cl group forms a hydrogen bond with glucose, enhancing the HMF production rate.

Green tea (Camellia sinensis) is intensely consumed all over the world and tea leaves discarded from production are a rich source of catechins, especially epigallocatechin-3-gallate (EGCG). This study aimed to perform preparative separation of EGCG from green tea waste by using macroporous resin and to reveal adsorption and desorption characteristics. Nine types of resins were compared for their adsorption and desorption capacities and desorption rate of EGCG, and NKA-2 was found the most suitable resin for the purpose. Adsorption isotherms were evaluated at 25 °C, 35 °C and 45 °C. Experimental data were well described with pseudo-second-order kinetics model and fitted best to the Langmuir model in tested temperatures. In dynamic separation process, 83% of adsorbed EGCG was recovered from the resin by using 70% ethanol. It has been thought that using macroporous resin can be an effective way of EGCG separation from green tea waste for commercial purposes.

Graphical abstract

This paper delves into the intricate relationship between the hemihexaphyrazine (HHP) network and its connection to topological indices and the heat of formation. By analyzing a variety of topological indices, we utilize a curve fitting model to predict and clarify the heat of formation–a vital thermodynamic factor that impacts the stability and reactivity of HHP. Through a detailed correlation analysis, we uncover significant trends and relationships linking the heat of formation with topological indices like the Gutman, Randić, and Zagreb indices. We have found that the curve fitting model not only allows us to predict the results with high accuracy (the values of (R^2) are above 0.98 in some cases) but also helps us to get a better idea about the molecular interactions within the HHP network. The reverse redefined Zagreb indices have been found to be the most predictively reliable of the tested ones. In addition, enthalpy measures were calculated in relation to each index, as a way to understand the complexity of structure, and showed steadfast growth trends in line with the growth of a network. These analyses illustrate the accuracy with which thermodynamic properties have been reproduced using the model; it outlines the relevance that topological descriptors have received in computational chemistry so far. By analyzing these results, several insights were obtained into the energetic behavior of hemihexaphyrazine network and are pointed out with respect to which role graph theoretical approaches so far played for the development of material science and chemical engineering.

Bacitracin is one of a group of antibiotic growth promoters that has been prohibited in the European Union. Its effectiveness is limited to a certain range of Gram–positive bacteria. In this study, a newly validated spectrofluorimetric approach was used to detect bacitracin in different types of water samples. The suggested spectrofluorimetric technique relied on the formation of a yellow fluorescence reaction product upon the interaction between BCT in a buffered solution at alkaline pH and 4-Chloro-7-nitrobenzofurazan reagent. The yielded reaction product has an excitation of 473.4 nm and a yellow fluorescence emission of 540 nm. To achieve maximum sensitivity and robust results, variables of the experiment such as pH, volume of derivatizing reagent, amount and type of buffer, diluting solvent, temperature of the reaction and heating time, post-reaction acidification, and stability time were examined and improved. In addition, the method exhibited a linear range of 0.5–3.0 µg/mL and an LOD value of 0.095 µg/mL. Additionally, the selectivity of the method against common antibiotics and metal ions was studied and evaluated. Moreover, the method was successfully applied to detect BTC in various water samples. Finally, the validated approach could possibly be employed in quality control laboratories for regular BCT analysis.