Chemical Data Collections最新文献

This study aimed to compare the essential oil yield and chemical composition of Artemisia herba-alba in the Anti-Atlas region, considering different harvest dates. The antibacterial and antifungal properties were also evaluated. Essential oils yields were 1.87 %, 1.85 %, and 2.35 % for the April, June and October harvests, respectively. Chromatographic analysis identified 21 compounds, with camphor, 1,8-cineole, and camphene as the main constituents. Artemisia herba-alba essential oils exhibited significant antibacterial and antifungal activities. The October-harvested oil showed notable antibacterial effects against Staphylococcus epidermidis (20 mm), while the June-collected essential oil demonstrated strong activity with a 20.66 mm inhibition zone against Acinobacter baumannii. Furthermore, the June-collected oil displayed significant antifungal activity with a 70.58 % inhibition index against Fusarium culmorum. Despite varying reducing powers with IC50 values, the antioxidant activity of the essential oils was relatively weaker compared to l-ascorbic acid, possibly due to the prevalence of non-phenolic compounds.

The present paper provides the physiochemical properties of binary systems of a bio-derived, eco-sustainable solvent furfuryl alcohol with 2-alkoxyethanols. Speed of ultrasound (U), density (ρ) of pure liquids and binaries of furfuryl alcohol with 2-methoxyethanol, 2-ethoxyethanol and 2-butoxyethanol have been measured at four temperatures from 303.15 K to 318.15 K (with interval as 5 K). From the measured experimental data, excess free length ($L_f^E$), excess volume per mole ($V_m^E$) and isentropic compressibility deviation (∆κ_s) have been calculated. For fitting the data of excess parameters, Redlich-Kister polynomial equation has been used and the corresponding standard deviation is computed. The variations in the parameters under investigation indicated molecular associations among the components of the mixture. Partial molar studies have approved these results. Further, FTIR spectral analysis has been undertaken to confirm the interactions of furfuryl alcohol and 2-alkoxyethanols. The FTIR analysis is well agreed with the thermodynamic findings.

Citrus reticulata Blanco essential oil was extracted using hydrodistillation, and its chemical profile was analyzed via GC/MS to give limonene as the major component (81.90 %). C. reticulata demonstrated remarkable antioxidant potential in DPPH (1,1-diphenyl-2-picrylhydrazyl) with in IC₅₀ (2.01 ± 0.01 mg/mL), ABTS (bleaching assay) (3.47 ± 0.02 mg/mL), and FRAP (iron reduction) (4.71 ± 0.43 mg/mL) assays, surpassing pure limonene. A synergistic effect was a key feature. In antibacterial tests, C. reticulata exhibited significant activity with a minimum inhibitory concentration (MIC) ranging from 12.5 to 25 µL/mL against four various bacteria (Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis and Escherichia coli). Moreover, C. reticulata displayed impressive anti-corrosion capabilities, achieving up to 92.5 % protection at 1000 ppm using PDP, and 93.1 % using EIS and 90.1 % using WL. Langmuir adsorption isotherm analysis supported inhibitor adsorption, and potentiodynamic polarization curves confirmed its mixed-type action. These findings highlight C. reticulata's promise as a natural antioxidant, antimicrobial, and anti-corrosion agent.

A new series of thiophene-bearing thiourea derivatives (1–11) were synthesized and characterized through ¹³C NMR, ¹H NMR and HR-EIMS. The synthesized derivatives were screened against acetylcholinesterase, and butyrylcholinesterase inhibitory potentials. All derivatives display a variable degree of inhibitory potential ranging from 0.40 ± 0.05 to 26.40 ± 0.40 µM (against AChE) and 1.80 ± 0.10 to 36.80 ± 0.90 µM (against BuChE) as compared to standard drug donepezil (IC₅₀ = 2.16 ± 0.12 µM and 4.5 ± 0.11 µM, respectively). In both cases, among the series analogues 3, 5, 7, 9, and 10 showed many folds better activity than standard drug donepezil. Structure-activity relationship has been also established for all newly synthesized compounds, mainly based on substitution patterns on the phenyl ring. The binding interaction of the most active derivatives with the active site of enzymes was confirmed through a molecular docking study. To evaluate the stability of the protein-ligand complexes 10 ns MD simulation was carried out. The most potent compound such as compound 3 revealed great stability during the 10 ns simulation.

The density values were measured as a function of mole fraction [(ethylene glycol or glycerol] for binary liquid systems such as [ethylene glycol or glycerol + (hexane or cyclohexane or benzene] at a temperature between 283.15 K and 328.15 K and atmospheric pressure. Using density data, the values of molar volumes, excess molar volume, and apparent molar volumes were calculated. Further, excess molar volume was correlated with the Redlich–Kister model. It is observed that in all systems, density data was decreased with an increase in the temperature and also increased with the concentration of ethylene glycol and glycerol. Excess molar volume for all the binary systems were positive deviations over the entire composition range. Each system exhibited more positive at a higher temperature. The obtained results are discussed in terms of packing efficiency, $\pi -\text{OH}$ bonding, and dispersion forces.

The primary focus of the study is to prepare and characterize water-soluble Boger fluids as they offer improved handling characteristics. The fluids have been prepared in the concentration range of 0.02–0.05 % (wt/vol.) Polyacrylamide (PAA) in a mixture of 80 % glycerol and 20 % distilled water by volume. Dynamic and steady shear data are represented in the temperature range of 15–35 °C. The shear mode data were fitted to power law model to calculate the flow consistency index (K) and flow behavior index (n). With increase in PAA concentration, the fluid character shifts from Boger to shear thinning viscoelastic fluid. Fluid relaxation time (λ) was calculated by fitting the oscillatory data to four mode Maxwell model. Empirical equations for the prediction of K, n, and λ are proposed by incorporating simultaneous effect of polymer concentration and temperature. Presented data could be of great use in unit operations such as fixed and fluidized beds dealing with Boger fluids.

This study assesses the impact of foaming agent type/content (hydrogen peroxide and Zn powder) and stabilizer content on the mechanical, thermal and microstructural of the elaborated geopolymer foams. Eighteen geopolymer foams were synthesized and their microstructure, density, porosity and compressive strength were analyzed before and after exposure to high temperatures (300 and 600 °C). To characterize the raw materials and the samples, several techniques were used, including X-ray fluorescence, X-ray diffraction, Magic-Angle Spinning Nuclear Magnetic Resonance Spectroscopy (²⁹Si and ²⁷Al MAS NMR), scanning electron microscopy (SEM), and porosity measurements. Thermogravimetric analysis was also performed to assess the thermal stability of the geopolymer foams with different foaming agent content and type. According to the results, the geopolymer foam with Zn powder as a foaming agent was more stable after exposure to the high temperature. The porosity increased after exposure to 300 °C, meanwhile decreasing after annealing at 600 °C.

High-voltage insulators were developed from CaCO₃ derived from waste snail shell to replace the low-impact energy ceramic insulators. The 15 wt% CaCO₃-snail shell/epoxy composite was produced using the solution stir-cast method. The UV radiation test, breakdown and flashover voltages, mechanical properties, tracking, and erosion depth of the developed composite were determined. A 116.7 and 43.82 % enhancement in the flashover voltage and leakage current was obtained at 1000 h of UV ageing. The developed insulator has longer thermal process breakdown strength and increased high-temperature insulation resistance. The properties attained in this work are within the acceptable range for high-tension insulator applications.It was established that waste snail shell could be used in the production of high-voltage insulators with high ultraviolet radiation resistance.

A new series of amide derivatives (10a–j) were designed and synthesized and their structures were confirmed by analytical data. Further, all these derivatives (10a–j) were examined for in vitro antitumor activity against four human cancer cell lines like MCF-7 (breast), A549 (lung), Col-205 (colon) and A2780 (ovarian) by using of the MTT assay. All the derivatives (10a–j) were exhibited remarkable anticancer effects on four cell lines as compared with etoposide used as a positive control. The IC₅₀ values range of tested compounds from 0.11 ± 0.051 µM to 7.42 ± 5.89 µM; whereas, positive control showed IC₅₀ values ranges from 0.17 ± 0.034 µM to 3.34 ± 0.152 µM, respectively. Among these derivatives, four compounds 10a, 10b, 10c & 10d demonstrated more potent activities than the positive control.