Journal of Saudi Chemical Society最新文献

Fluopyram is a highly effective agricultural fungicide targeting succinate dehydrogenase (SDH). Twenty-six novel amide derivatives containing azetidine were designed and synthesized with fluopyram as the lead, and their biological activities were tested. The results showed that some compounds had obvious antifungal activities against Phomopsis sp., among them, the EC₅₀ value of compound C24 was 5.7 mg/L, which was significantly better than fluopyram (105.4 mg/L). The curative and protective activities of compound C24 on kiwi fruit infected with Phomopsis sp. were 42.2 and 52.9 %, which were better than that of fluopyram (30.4 and 35.6 %) at 200 mg/L. Moreover, compound C24 exhibited excellent inhibitory against SDH. The results of scanning electron microscopy (SEM) indicated that the mycelium of Phomopsis sp. collapsed or even ruptured after compound C24 treatment. Meanwhile, molecular docking showed that compound C24 was deeply embedded into the SDH binding pocket, and the binding model was stabilized by a cation–π interaction with Cys-40, Tyr-58 and an H-bond with Lys-455 and Asn-452. Compound C24 can provide a valuable idea to find new succinate dehydrogenase inhibitors.

The present study describes an environmentally benign biological method for the production of zinc oxide nanoparticles (ZnO NPs) by blending water-based leaf extract from a sustainable bio-source, the Arjuna tree, under ambient conditions. Aqueous leaf extract comprised of different reducing agents appeared as the precursor for phytofabrication, and zinc nitrate hexahydrate (ZnNO₃·6H₂O) acted as a zinc source. The phytofabricated Arjuna-ZnO NPs had a hexagonal shape with an average size of 31.14 nm, as revealed by HR-TEM, FE-SEM micrographs, and XRD patterns. The FESEM-EDS micrograph and the XRD patterns also revealed the elemental composition, phase purity, and crystalline nature of phytofabricated Arjuna-ZnO NPs. The initial formation of ZnO NPs was confirmed by absorption maxima at approximately 376 nm and Zn-O stretching vibrations at 520 cm⁻¹ using UV–VIS and an FT-IR spectrophotometers, respectively. The aqueous extract of Arjuna leaf was also analysed using FT-IR spectrophotometer to identify the functional groups of bioactive substances that participated in the reduction and encapsulation processes. The efficacy of the Arjuna-ZnO NPs was assessed in terms of their ability to photocatalyzed on three noxious dyes, methylene blue (MB), methyl orange (MO), and congo red (CR), for high commercial and industrial usage. The phytofabricated Arjuna-ZnO NPs were photoactive and proved highly efficient and effective nano-photocatalysts for the photodegradation of three dyes, MB, MO, and CR, under natural sunshine, underscoring their potential for effective remediation of environmental pollutants. The degradation process adhered to pseudo-first-order kinetics in terms of adsorption kinetics.

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.

Carbon nanotubes (CNTs) are highly promising materials for the adsorption of dyes from water. Recently, there has been a growing interest in Prussian blue-type coordination polymers due to their inexpensive nature, chemical stability, and simple synthesis using non-toxic metals that are prevalent in the earth. The results present a straightforward technique for effectively altering the surface of CNT using cobalt-iron-based prussian blue (CoFe-PB). The procedure led to a significant increase in the removal of crystal violet (CV) from water relative to the bare CNTs. The maximum removal efficiency (about 93 %) of CV dye was obtained at pH 6 with fast saturation time (15 min). The use of the coating approach yields a core–shell structure consisting of CNT as the core and a CoFe-PB shell. The CoFe-PB shell, with a thickness of 10–15 nm, forms a highly conformal coating that completely covers the CNT. The high conformance of the coating is considered an essential characteristic for its strong adsorption performance. The method demonstrates the significant potential of prussian blue-type materials, when appropriately coated, as very effective adsorbent materials.

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.

The photocatalyzed cleavage of cycloketoximes is a promising approach for modifying their biological activity and designing prodrugs activated by light. Cycloketoximes containing a cyclic ring structure that can hinder their degradation and modification in biological systems. Photocatalysis offers a sustainable and efficient method for breaking down the cyclic structure using a photocatalyst and exposure to ultraviolet light. These reactions are initiated by iminyl radicals, that gain access to distal-carbon through selective C–C cleavage. This process provides a solution for the challenging task of modifying the biological activities of cycloketoximes. Moreover, it can also be useful for selectively removing protecting groups from organic molecules or cleaving specific chemical bonds, thereby facilitating organic synthesis.This review article covers synthetic uses of photocatalyzed cleavage of cycloketoximes and highlights its ongoing research in the field of photocatalysis.

A highly efficient diazotization of diazoacetates with para-quinone methides has been established via a tetrabutyl ammonium bromide (TBAB)-catalyzed 1,6-conjugated addition pathway. This methodology affords a convenient, safe, and rapid way to generating diverse polysubstituted α-diazocarbonyl compounds, displaying good functional group tolerance, high atom economy, and easy accessibility.

Recently, tungsten disulfide (WS₂) has received considerable attention in aspects of electrocatalytic oxygen evolution reactions (OER). However, due to the restricted number of active sites, WS₂ nanoflower has a high overpotential in OER. Thus, we provide herein a doping approach for doping WS₂ nanoflower with non-noble aluminum (Al) metal to increase active sites in an effort to enhance the OER activity of WS₂. The positive electrocatalytic effect of Al-doping on WS₂ material results in a lower OER operating overpotential. In comparison to undoped WS₂, the skeleton-like structure (0.04 %) Al-doped WS₂ nanoflowers significantly enhanced OER catalytic activity with an overpotential of 650 mV at the current density of 6 mA cm⁻². Furthermore, the impact of different mass loadings of (0.04 %) Al-WS₂ on the OER performance has been examined using electrochemical analysis. The success of using aluminum dopants to improve OER performance would have a significant impact on the development and production of non-noble metal sulfide-based electrocatalysts for OER.

The use of biomass as a renewable, sustainable, and eco-friendly energy source is now widely recognized as a potential solution for a variety of environmental problems. To develop biodiesel production, cost-effective feedstocks such as agricultural waste, food waste, and non-edible/waste cooking oil were utilized. A heterogeneous solid base catalyst was synthesized by calcining a mixture of waste golden apple snail shell (Pomacea canaliculata) and cultivated (Musa sapientum) banana peel. In transesterification process, potassium oxide (K₂O) derived from banana peel is used as a cocatalyst to improve the catalytic activity of calcium oxide (CaO) catalyst derived from waste shell. The innovative CaO-K₂O catalyst was investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF) and the Brunauer-Emmett-Teller (BET) technique. The morphology and elemental composition of calcium (Ca), potassium (K), and oxygen (O) in the catalyst were validated by field emission-scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). The CaO catalyst exhibited a BET surface area of 10.88 m²/g, which was enhanced to 14.62 m²/g upon combination with K₂O. The Hammett indicator of CaO catalyst fell between 7.2 < H_< 9.8. However, the CaO-K₂O catalyst exhibited a higher value of 15.0 < H_< 18.4, which could be attributed to the phase transition from CaO to CaO-K₂O. To investigate the effects of catalyst concentration, ethanol/oil molar ratio, and transesterification time on the yield of fatty acid ethyl ester (FAEE). The optimal conditions for FAEE synthesis were determined using a central composite design (CCD) approach with response surface methodology (RSM). The regression equation obtained for the CCD model has a determination coefficient (R²) of 0.9921, indicating that this model is well-fitted. At 3.69 wt% catalyst concentration, 19.48:1 ethanol/oil molar ratio, and 1.80 h transesterification time, the highest FAEE yield from Jatropha Curcas oil (JCO) of 97.06 % was obtained. The novel catalyst has a strong yield and can be utilized for up to 6 cycles. It was found that the corresponding yield was 90 % when employing the same process parameters, demonstrating the high reusability of this catalyst. The biodiesel produced from non-edible JCO meets the criteria for standard biodiesel (ASTM D-6751 and EN 14214). The CaO-K₂O catalyst is inexpensive, easy to make, biodegradable, recyclable, and environmentally friendly because it is derived from a biological residue. Because of these characteristics, it may be an appropriate candidate for the role of “green catalyst” in sustainable energy production.

The target compounds 4-(((1H-heteraryl)imino)methyl)-N,N-bis(4-(((4-((4-nitrophenyl) diazenyl)phenyl)imino)methyl)phenyl)aniline (7a-q) were prepared starting with 4,4′-diformyltriphenyl amine (2) which subjected to react with N-bromosuccinimide to give bromodiformyltriphenyl amine (4). Compound 4 reacted with two moles of 4-nitro-4′-aminoazobenzene to give the di-Schiff base 5. Compound 5 converted to its corresponding formyl derivative 6 by reaction with n-BuLi. The reaction of the formyl derivative 6 with seventeen amino heteraryl compounds afforded the target compounds 7a-q. All the newly prepared compounds were characterized by different spectroscopic and elemental analyses. Compounds 7a-q were screened for their antimicrobial activities against yeast-like fungi (C. albicans), Gram-negative (GN) bacteria (P. aeruginosa and E. coli), and Gram-positive (GP) bacteria (S. thuringiensis and B. subtilis). Compounds 7d, 7k, 7l, and 7q showed the highest activity against Gram-positive bacteria. The results of antimicrobial activity showed that it is highly affected by the used amine basicity.