Journal of Saudi Chemical Society最新文献

The synthesis and biological assessment of 2,5-disubstituted-1,3,4-oxadiazoles derivatives from amino acids as new potential antibacterial and antioxidant agents have been reported. The structures of the new synthesized compounds were characterized based on physicochemical and spectral data UV–Visible, IR, ¹HNMR, ¹³CNMR. All the target compounds were screened for their in vitro antibacterial activity against three Gram-positive bacterial strains, namely Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Listeria innocua ATCC 33090, and two Gram-negative bacterial strains, namely Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and antifungal activity against Candida albicans ATCC 10231 in comparison with Amoxicillin, Tetracycline, Gentamicin and Oxacillin. The only compound 1-{(4S)-4-amino-4-[5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]butyl}guanidine 5e with the amine radical that showed excellent results against all bacteria, particularly against L. innocua (IZ = 12 mm), has excellent antifungal activity (IZ = 32 mm). The compounds 2-[5-(1-amino-3-methylbutyl)-1,3,4-oxadiazol-2-yl]phenol 5b and 2-[5-(pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl]phenol 5j have excellent activities (IZ = 27 and IZ = 28 mm, respectively) against B. cereus and P. aeruginosa. Compounds 2-{5-[(1R)-1-amino-2-sulfanylethyl]-1,3,4-oxadiazol-2-yl}phenol 5c, 2-{5-[(1S)-1-amino-3-(methylsulfanyl)propyl]-1,3,4-oxadiazol-2-yl}phenol 5d with the sulfur radical, 3--[5-(2-3-amino hydroxyphenyl)-1,3,4-oxadiazol-2-yl]propanamide 5g with the amide radical, 5j with the amino radical, and 4-amino-4-[5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]butanoic acid 5k gave good results against B. cereus, where 19 mm < IZ < 23 mm. We also found that compound 5j has the greatest activity (IZ = 33 mm) against C. albicans, followed by compounds 5e (IZ = 32 mm) and 5b (IZ = 30 mm). The synthesized compounds were also screened for radical scavenging antioxidant activities by DPPH, FRAP, and TAC assays and found to be good antioxidant agents. According to the IC50 values, all compounds demonstrated good to excellent activity, especially 5b and 2-{5-[1-amino-2-(1H-imidazol-4-yl)ethyl]-1,3,4-oxadiazol-2-yl}phenol 5i for DPPH, 5e and 5i for FRAP and methyl 2-hydroxybenzoate 2, 2-{5-[1-amino-2-(1H-indol-3-yl)ethyl]-1,3,4-oxadiazol-2-yl}phenol 5h with the imidazol group and 2-[5-(1,5-diaminopentyl)-1,3,4-oxadiazol-2-yl]phenol 5f with the imidazol group for TAC. All these compounds showed better activity than AA and BHT.

The conversion of organic waste into valuable commodities is essential for safeguarding the environment and promoting the sustainable development of the economy. This investigation centres on the production of Zinc ferrite nanoparticles (ZnF NPs), modified eggshells (MES) impregnated with chitosan (CS) and coated with poly ortho-toluidine P(OT) nanocomposites (NCs). This synthesis involves a quaternary composition denoted as P(OT)/MES/CS/ZnF NCs, achieved through chemical polymerization techniques. The resulting NCs were characterized and applied for the removal of Brilliant Green (B.GR) and Acid Red (A.RE). Four distinct compositions, namely pure P(OT), binary P(OT)/MES, ternary P(OT)/MES/CS, and quaternary P(OT)/MES/CS/ZnF NCs, were synthesized. The outcomes revealed that the quaternary P(OT)/MES/CS/ZnF NCs exhibited the highest adsorption capacities for B.GR and A.RE at)27.03 and 142.8 mg⁻¹(, respectively. The findings revealed that the most favorable parameters for the removal of A.RE were attained at a pH of 2, using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 25 mg/L for a duration of 120 min. On the other hand, when it comes to removing B.GR, the best results were shown while using 15 mg of P(OT)/MES/CS/ZnF NCs at a concentration of 5 mg/L for 120 min, specifically at a pH of 6. The greatest real wastewater removal efficiencies for A.RE dye and B.GR dye, respectively, were found to be 99.5% and 97.6% under these operating circumstances. These optimal quaternary NCs demonstrated the ability to be regenerated four times without significantly compromising their adsorption properties and exhibited a remarkable capacity to remove 96–98% of dyes from real polluted water. Through the use of regression data and a pseudo-second-order model, the adsorption kinetics were explained, with R² values of 0.994 for A.RE and 0.993 for B.GR, respectively. Thermodynamic parameters of dye adsorption by the NCs affirmed the fact that adsorption occurs spontaneous and have endothermic nature. This study underscores an effective synthesis approach applicable for large-scale production of new adsorbents for water treatment purposes.

A series of six novel polyesters (P₁-P₆) were obtained via by direct polycondenzation with hydroxyl functional-appended chromone and curcumin based monomers (M₁, M₂ and M₃) were synthesized and subjected to thermogravimetric and spectroscopic analyses for structural characterization. The synthesized polymers were soluble common organic solvent such as DMF, THF, DMAc and 1-methyl-2-pyrrolidinone (NMP). The molecular weight of the polymers was found to be ranged from 3.390 × 10⁵ – 1.1 × 10⁵ g/mol by GPC-MALS. X-ray diffraction pattern of polyesters indicates P₁, P₂ and P₃ are amorphous in nature, whereas polymer P₄, P₅, and P₆ shows crystalline nature. The receptor VEGFR2 kinase can expand the synthesized molecules into 2D and 3D supramolecular networking through π-π stacking, hydrophobic, and H-bonding interactions. The cell viability effects of polymers on the growth of cell lines A549, HeLa and VERO were evaluated in vitro by MTT assay. The polymer P₃ displayed potent anticancer activity compared to the other polymers. Research is undergone in developing curcumin chromone functional polymer as a workable biopolymer which could find value in the present findings.

There is a growing demand for decreasing fossil fuel usage. That being said, we should move toward renewable and sustainable energy sources. Iron-based catalysts are usually employed in this route. In this work, an incipient impregnation process was used for preparing four γ-Al₂O₃ supported iron-based catalysts with different weight percents including 20Fe/5Cu/γ-Al₂O₃, 20Fe/5Cu/2K/γ-Al₂O₃, 20Fe/5Cu/3Zr/γ-Al₂O₃ and 20Fe/5Cu/1.5Zr/1K/γ-Al₂O₃ under the pressure of 20 atm, the temperature of 285 °C, H₂ to CO ratio of one, and a gas hourly space velocity of 2 NL/ (h. gCat). BET, FE-SEM, XRD, H₂-TPR, ICP, and TEM techniques were used to determine the characteristics of the catalysts, while gas chromatography results were used to determine CO conversion and product selectivity. Due to the synergistic effect of the two promoters, the doubly-promoted catalyst exhibited a C₅⁺ selectivity of 64.2 %, surpassing both the Fe/Cu/γ-Al₂O₃ catalyst and the singly-promoted catalysts. This result highlights the enhanced performance of the doubly-promoted catalyst. Compared to the other catalysts prepared, the doubly-promoted catalyst demonstrated a higher carbon monoxide (CO) conversion rate of 67.7 % and yield of 43.5 %. Moreover, The results demonstrate the significant impact of Zr and K promoters of the synthesized Fe-based catalysts on hydrocarbon product distribution.

A nitrogen-phosphorus dual-doped auricularia auricula carbon (NP-AC) matrix was prepared through hydrothermal treatment using natural auricularia auricula as raw material and medium solution. Yeast was introduced and cultured by the auricularia auricula liquid medium. The NP-AC/S composite was prepared through further freeze-drying, carbonization, activation and compounding with sulfur procedures. The composition and microstructure of samples was characterized by X-ray diffraction (XRD), raman and X-ray photoelectron spectroscopy (XPS). The morphology was observed under scanning electron microscope (SEM) and transmission electron microscopy (TEM) method. The specific surface area was analyzed using nitrogen adsorption/desorption test. The weight ratio of sulfur was measured through thermogravimetric (TG) analysis. The original structure and composition of biomass were improved by yeast fermentation and the auricularia auricula block structure with low porosity was modified. The electrochemical performance of NP-AC/S composite in Li-S batteries was systematically explored. After 100 cycles at 0.2C current density, there was still nearly 1000 mAh g⁻¹ reversible capacity, holding a capacity retention rate of more than 84 %. The cycle performance and rate performance were both far better than the ordinary activated carbon materials.

Herein, a novel magnetic visible-driven g-C₃N₄/TiO₂/CuFe₂O₄ nanocomposite with excellent photocatalytic performance was successfully prepared and employed for photodegradation of tetracycline. Several analysis including X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), energy dispersive X-ray (EDX), Vibrating-Sample Magnetometer (VSM), and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS) were performed in order to study the structural, optical, magnetic, as well as morphological properties of nanocomposite. The optical band gap of g-C₃N₄/TiO₂/CuFe₂O₄ heterostructure was found to be red shifted to 2.45 eV from 3.15 eV for pure TiO₂. Enhanced separation of photoinduced electron-hole pairs and enhanced visible light absorption capacity of nanocomposite lead to a maximum tetracycline photodegradation efficiency. Response surface methodology (RSM) was used to investigate the influence four independent variables, including initial photocatalyst dosage (7–14 g/L), TC concentration (20–30 ppm), solution pH (5.5–7.5), and irradiation time (20–40 min), and optimize the TC degradation efficiency. The g-C₃N₄/TiO₂/CuFe₂O₄ nanocomposite was able to separate and recycle easily using an external magnetic field, and the results of reusability was shown its high stability after 5 cycles. Active species trapping experiments suggested that holes and hydroxyl radicals played a crucial role in the TC degradation process. Finally, a potential photocatalytic mechanism for photodegradation of TC was proposed.

In this study, a novel copolymer hydrogel according to poly (acrylonitrile-co-sodium styrene sulfonate) (ASD) as an effective adsorbent was prepared via free radical polymerization of the solution at a ratio of 1:1 to remove cationic crystal violet dye (CV) from wastewater. The prepared hydrogel was thoroughly characterized using FTIR, TGA, SEM and EDX analysis. The hydrogel that was produced has a notable capacity for adsorbing cationic dye uptake over a wide pH range as well as easily separated without the need for filtration and centrifugation. Under optimal conditions using 1 g/L of hydrogel, 400 mg/L dye concentration and contact time of 5 h, the prepared hydrogel showed high dye removal efficiency approaching 100 %. The sulfonated copolymer hydrogel has a maximum adsorption capacity of 518.49 mg/g, which is six times larger than pristine PAN. The Langmuir model properly represented the isotherm adsorption data, however the kinetics data was better described by the pseudo-second-order model. Based on the calculated thermodynamic characteristics, the process of CV dye adsorption on sulfonated copolymer hydrogel surface was spontaneous and exothermic.

Two silver alkynyl clusters, [(CO₃²⁻)@Ag₂₀(^tBuC≡C)₁₄(PhCOO)₃(CF₃COO)] (1) and [(CO₃²⁻)@Ag₂₀(^tBuC≡C)₁₄(PhCOO)(CF₃COO)₃] (2), composed of alkynyl Ag₂₀ shell templated by a CO₃²⁻ anion and supported by carboxyl ligands PhCOO⁻ and CF₃COO⁻, were synthesized successfully by conventional methods. Single crystal X–ray diffractometer (SCXRD) was used to determine the precise structures of 1 and 2. Although compounds 1 and 2 have the [(CO₃²⁻)@Ag₂₀(^tBuC≡C)₁₄]⁴⁺ unit, the numbers of PhCOO⁻ and CF₃COO⁻ ligands along with Ag···Ag interactions were affected by the steric hindrance of different carboxyl ligands and their concentrations. That is, compounds 1 and 2 separately contain the [(CO₃²⁻)@Ag₂₀(^tBuC≡C)₁₄(PhCOO)(CF₃COO)]²⁺ unit, which is involved in the ligand exchange between PhCOO⁻ and CF₃COO⁻. Powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) were used to characterized compounds 1 and 2. The photocurrent responses, absorption spectra, as well as luminescence of 1 and 2 have been studied. In addition, the reduction of H₂O₂ for GCE–1 and GCE–2 showed good electrocatalytic activity, and catalysts 1 and 2 showed good photocatalytic degradation efficiency of methylene blue (MB). The results suggest that 1 and 2 can act as new electrocatalysts and photocatalysts to detect and decompose organic pollutants and hazardous materials in wastewater.

Local bacterial infection remains an increasingly severe threat to human health worldwide, and infection control is still a challenging task. Carbon Quantum Dots (CQSs) and barium tungstate show antibacterial properties. CQDs doped Barium Tungstate (BaWO₄) are synthesized by using a hydrothermal route and their optical and antimicrobial activities against the Gram-positive bacteria staphylococcus aureus and optical properties were investigated. The UV–Vis reveals a shift in the bandgap from 3.62 eV to 2.93 eV due to doping of CQDs in BaWO₄. The structure of the CQDs/BaWO₄ were studied by XRD, which shows CQDs doped BaWO₄ samples possess tetragona4 werelite structure with the preferred orientation of (1 1 2) identified by XRD at 26° having crystallite size ∼ 31 nm. Nanocomposite BaWO₄/CQDs exhibit a spherical-like shape and are composed of Ba, O, W and C according to the design of the experiment. Zeta sizer of CQDs by DLS shows the size of CQDs is 7.65 nm. The FT-IR shows the presence of functional groups in doped material like CC, CO, and COOH bonds which indicate that the C-dots are functionalized with epoxy, carbonyl, hydroxyl, and carboxylic acid groups. Their elemental composition and surface morphology were studied by EDS which shows the percentage variation of CQDs in BaWO₄, SEM results show the change in shape of the sample by adding CQDs to BaWO₄. The TEM image proves the presence of doped material in the BaWO₄. The PL spectra reveals the emission spectra shift towards a higher wavelength and absorption increases. The qualitative analysis shows the antimicrobial activity and enlargement of the inhibition zone and quantitative analysis confirms it.

Photocatalytic responses and synergistic effects of V₂O₅, TiO₂, and V₂O₅/TiO₂ heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V₂O₅/TiO₂ heterostructures increases with higher TiO₂ concentrations. These findings enhance our understanding of the agglomerated heterostructures of V₂O₅/TiO₂, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V₂O₅/TiO₂ heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.