Journal of Saudi Chemical Society最新文献

This works documents a new silica gel-supported nanocatalyst (Si@NSBPdNPs 3) with low Pd loadings for n-alkylation reactions at room temperature. Post synthesis characterisation using SEM-EDX and ICP techniques provided a quantitative assessment of palladium species. Additionally, TEM analysis unveiled an average palladium nanoparticle size of 5.87 ± 0.2 nm. In-depth X-ray Photoelectron Spectroscopy (XPS) analysis revealed its predominant composition as Pd(0) complexed to a Schiff base ligand on low cost silica matrix. The nanocatalyst exhibited high efficacy in the catalysis of n-alkylation (Michael addition) reactions with various α,β-unsaturated Michael acceptors, yielding the corresponding n-alkyl products at room temperature with exceptional yields. Notably, the catalyst exhibited good stability and could be easily separated from the reaction mixture. Moreover, the catalyst displayed recyclability potential, maintaining its original catalytic efficacy for up to seven cycles without any discernible loss.

Urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) are the key processes for implementing urinated water electrolysis and hydrogen green production, respectively. This contribution investigates the modification of commercial nickel foam (NF) with a nickel phosphate (NiPO/NF) heterostructure layer via anodizing in phosphate solution at various potentials (5, 10 and 15 V) as a simple and efficient route to boost the urea-assisted water electrolysis and hydrogen production in alkaline medium. The morphology and composition physicochemical characterisation of the phosphate layer exhibit aggregates of crystalline nanoparticles with interstitial mesoporous and macroporous networks with a mole composition ratio of 9.42: 1.0: 8.14 for Ni: P: O respectively. The electrochemical measurements revealed the NiPO/NF anodized at 10 V exhibits a superior electroactive surface area of 255 cm², a substantially higher urea oxidation current compared to pristine NF, achieving 20 and 500 mA/cm² at 1.35 and 1.6 V vs. RHE respectively and retained 100 % of activity during the urea electrolysis for more than 3 h. The electrochemical impedance analysis confirmed the alkaline urea oxidation reaction proceeded via indirect (EC) and direct mechanism and the CO₂ intermediates adsorption–desorption became the predominant reaction at more positive potential. The NiPO/NF anode employed in an H-shape can deliver up to ±400 mA/cm² for UOR/HER at a bias potential of 1.85 V and 8-fold (2.0 mmol/min) much higher hydrogen production rate compared to the pristine NF anode (0.25 mmol/min). Combining commercial nickel foam modification via anodizing and alkaline urea electrolysis at ambient conditions offers a unique and innovative solution for both large-scale hydrogen green production as well as remedy of the urinated wastewater for a more sustainable future.

Herein, durable multi-functional silk is successfully prepared via in-situ clustering of nanopalladium, under the assistance of infrared irradiation. Whereas, the produced fabric acquired superior antimicrobial, UV-resistance and self-cleaning potentialities. Different instrumental analyses were performed, to reveal that; size average of nanopalladium was ranged in 8.6–21.4 nm. Additionally, increment in the nanopalladium concentration reflected in observable improvement of the mechanical properties, color strength and thermal stability. Yellowish degree was significantly increased from 22.36 for silk finished with 100 ppm of nanopalladium (silk-Pd-1) to 42.52 for silk finished with 300 ppm of nanopalladium (silk-Pd-3). Functional treatment of silk with higher concentrated nanopalladium exhibited the highest microbicide action even after 5 washing cycles, the microbial reduction percentage was evaluated to be 67 %, 65 % & 70 % against “St. Aureus, E. Coli and C. Albicans”, respectively. Ultraviolet protective factor (UPF) was superiorly evaluated for silk-Pd-3 to be 98.1 and 40.4 before and after 5 washing cycles. The aid of nanopalladium for acquiring the prepared silk the self-cleaning property as add-function was approved via kinetic study to show that the prepared fabrics exhibited good self-cleaning character by successive in-clustering of nanopalladium, while, t_1/2 for dirt removal was 190.9 min.

The combination of heterocycles renders a new possibility to synthesize multicyclic compounds having improved biological activities. Furo[3,2-b]pyridine is a fused heterocyclic ring system comprising a furan ring attached at the third and second positions of pyridine. These heterocyclic compounds can be easily synthesized from versatile starting materials including pyridine, furan, benzofuran, and benzopyridine via cycloaddition, cycloisomerization, multicomponent, cross-coupling, and Dakin-type reactions by utilizing microwave, copper, and palladium based catalysts. Among the chemical transformations of furo[3,2-b]pyridine derivatives, the review covered acetylation, addition, condensation, chlorination, Suzuki coupling, Vilsmeier-Haack reaction, and nucleophilic substitution reactions. Furo[3,2-b]pyridine has attracted remarkable attention from researchers due to its wide range of pharmacological and biological applications as antibiotic, antiviral, antifungal, anticancer, inhibitors of nicotinic acetylcholine receptors, CLKs, e1F4A, DYRKIA, α-glucosidase and β-glucosidase. The purpose of the review is to discuss the chemistry of the title reported during 2019–2024.

α-Glucosidase and urease inhibitors have emerged as crucial for developing therapeutic drugs targeting diabetes and gastrointestinal disorders. This study reports on new series of ibuprofen and mefenamic acid Schiff base derivatives incorporating isatin as dual inhibitors of α-glucosidase and urease enzymes. These synthesized derivatives (7a-r) were structurally characterized by ¹H NMR, ¹³C NMR and HRMS (EI). Biological evaluation (IC₅₀) identified several derivatives i.e., 7a (urease = 17.37 ± 1.37 µM, α-glucosidase = 44.1 ± 1.15 µM), 7j, (urease = 16.61 ± 1.37 µM, α-glucosidase = 81.2 ± 1.33 µM), 7o, (urease = 18.63 ± 1.27 µM, α-glucosidase = 70.3 ± 1.14 µM), 7r (urease = 11.36 ± 1.32 µM, α-glucosidase = 39.3 ± 1.17 µM), as dual inhibitors of urease (thiourea 21.37 ± 1.76 µM) and α–glucosidase (acarbose 375.82 ± 1.76 µM) enzymes. These bioactive derivatives were explored for cell viability studies against mononuclear cells revealing a good cytocompatibility. In silico molecular docking studies were also conducted to predict the binding mode of new derivatives with target enzymes that were found consistent with the results of in vitro research.

Herein, magnesium sulphide (MgS) electrode material (EM) is deposited on nickel-foam (NF) placed at 16 and 17 cm away from the raw material by simple powder vapour transport method. The increasing source to substrate distance (SSD) not only changed the structural parameters but also changed the nanofibers to cauliflowers like surface morphology. The cauliflowers like MgS/NF EM exhibited high specific capacitance (6339 F/g) as compared to the specific capacitance (1677 F/g) of nanofibers like MgS/NF EM. The cauliflowers like EM is showed high energy density of 220–99 Wh/kg, power density of 250–2500 W/kg, equivalent series resistance of 0.95 O and capacitance-stability of 93 % even for 10,000 cycles. The increasing SSD is fruitful for the increment in diffusion rate as confirmed by shifting of electrochemical impedance spectrum to y-axis, Dunn’s model and power law simulations. The diffusive contribution is 88/82 % at 5 mV/s which become 63/50 % at 100 mV/s for the cauliflower/nanofibers like EM. Moreover, the cauliflowers like EM have both battery and capacitive nature as 0.5 < b < 1 predicted by power law simulations. Additionally, the configured asymmetric supercapacitive (ASC) device is presented the specific capacitance of 834 F/g, energy density of 354–247 Wh/kg and power density of 2625–26250 W/kg. The ASC device could maintain the Coulombic-efficiency of 99 % and capacitance stability of 93 % even for 10,000 cycles. The excellent pseudocapacitive behaviour of MgS/NF EM enables them to use in the lithium ion battery and supercapacitor devices.

Hippuric acid is a biotransformation product in humans which is excreted through urine. Dietary intake of phenolic compounds increases its concentration in urine. Hippuric acid is experimentally proved to be a regulator of calcium oxalate super saturation in human urine and has a solvent effect on oxalate salts. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used analgesics employed in associated renal colic of urolithiasis. The objective of the present study was to chemically link hippuric acid through anhydride linkage to various NSAIDs to synthesize potential mutual prodrugs for urolithiasis and associated renal colic. Hippuric acid was linked to eleven NSAIDs through anhydride linkage by first synthesizing hippuryl chloride using oxalyl chloride as chlorinating agent, followed by its reaction with sodium salts of NSAIDs. Structures of obtained compounds were elucidated using UV spectrophotometry, FTIR spectrometry, 1H NMR and C-13 NMR spectrometry. Synthesized compounds were evaluated for in vitro antioxidant, in vivo acute toxicity, in vivo antiurolithic, in vivo analgesic and in vitro hydrolysis studies. Molecular docking analysis on TNF-α and COX-2 was carried out to determine target protein binding. Synthesized compounds showed stability at acidic pH which indicate potential gastro protective effect of synthesized conjugates. Compounds P9 an P6 showed maximum in vivo antiurolithic activity while P9 and P8 showed maximum in vitro antioxidant activity. All the conjugates except P2 showed significant analgesic activity which show that conjugation of hippuric acid to NSAIDs did not result in loss of analgesic potential. Docking studies showed better affinity with TNF-α as compared to COX-2.

The escalating issue of infectious agents developing resistance to traditional antibiotics has spurred ongoing research into effective and broad-spectrum antimicrobial solutions. This study focuses on the fabrication of silver-zinc oxide Nanohybrids (A-ZnO-NHs) with varying silver content (1 %, 3 %, 5 %) using a simplified modified sol–gel method, further enhanced by a green synthesis approach utilizing orange peel extract for the generation of silver nanoparticles. The physicochemical characteristics of the A-ZnO-NCs were thoroughly examined. X-ray diffraction analysis verified the presence of Ag nanoparticles within the zinc oxide and scanning electron microscopy revealed the nanoscale silver particles uniformly distributed on the spherical zinc oxide nanoparticles. Transmission electron microscopy indicated that the Ag-ZnO-NCHs ranged in size from 10 to 20 nm. X-ray photoelectron spectroscopy analysis confirmed the formation of strong chemical bonds between the silver and zinc oxide surfaces in the nanohybrids. This study explored into the structural, morphological, and antimicrobial characteristics of the A-ZnO-NHs at different compositions. The bactericidal efficiency of the A-ZnO-NHs was assessed against both gram-positive and gram-negative bacterial strains. The impact of the A-ZnO-NHs on the cellular structure and chemical composition of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was also explored. The findings revealed that the A-ZnO-NHs with 3 % silver content demonstrated higher antimicrobial activity against E. coli and S. aureus compared to other compositions and pure zinc oxide nanoparticles. The antimicrobial activity decreases when the concentration of silver increases because the silver particles agglomerate together, reducing their surface area and lessening their effectiveness as antibacterial agents, despite their potential for various applications.

To accurately diagnose and evaluate the degree of myocardial injury and predict myocardial infarction disease, the rapid and sensitive detection of cardiac troponin I (cTnI) is required. Therefore, a label-less electrochemical aptasensor was prepared for cTnI determination. Ionic liquid 1-hydroxyethy l-3- methyl imidazole four fluorine boric acid salt (IL)-reduced graphene oxide − four ethylene oxidation reduction five amine (rGO-TEPA)/silica (SiO₂)- gold platinum (AuPt) (IL-rGO-TEPA/SiO₂-AuPt) nanocomposites were synthetized as the substrate nanocomposite and were characterized using a series of characterization methods. The performance of the prepared aptasensor was characterized through electrochemical methods. Result displayed that better substrate materials were synthesized, and the prepared electrochemical aptasensor showed excellent electrochemical performance. Under optimal conditions, the electrochemical aptasensor had a salient analytical performance. The electrochemical signals linearly decreased with the logarithm of the cTnI concentration between the 0.5 pg·mL⁻¹ and 1 × 10⁶ pg·mL⁻¹ concentration range (R² value = 0.9955) and the aptasensor had a wide detection range (0.5 ∼ 1 × 10⁶ pg·mL⁻¹) and a low detection limit of 0.4 pg·mL⁻¹. At the same time, the aptasensor had good selectivity, repeatability and stability. Relative standard deviation (RSD) values ranged from 3.45 % ∼ 4.97 % and the recovery rate was 97.5 % ∼ 103 % in human serum samples, the RSD values of the spiked recovery and ELISA method were less than 5 %. This study provides a new theoretical basis and method for the clinical detection of cTnI.

Ammonium salt vanadium precipitation process has excellent performance in industrial production, but its shortcomings such as high cost and environmental impact are not conducive to sustainable development. In this paper, ethylenediamine was selected as the precipitant, and vanadate was precipitated from acidic simulated vanadium-rich solutions by the ammonium salt precipitation process. The high purity V₂O₅ product was obtained after calcination. Under optimal conditions, the precipitation rate of vanadium reached 94.8 %, and the purity of vanadium was as high as 99.1 %. The vanadium precipitation product was hexamethyl ammonium, and the vanadium product was V₂O₅. It can be derived by the differential method that the reaction order was n = 2.4, the reaction rate equation was $C_V^{-1.4}=kt+a$, and the apparent activation energy was 27.8097 kJ/mol, which can be classified as the diffusion-controlled reaction. This innovative process enables a savings of 5050 yuan per ton of V₂O₅. On this basis, a complete V₂O₅ production process with zero waste discharge was designed.