Journal of Saudi Chemical Society最新文献

This work aims to evaluate the antimicrobial activity of some new quinoline derivatives linked to pyrazole derivatives. The target compounds pyrazolylvinylquinoline 11a-g and 12a-g were achieved by the reaction of 2-chloro-6-nitro-3-quinolinecarboxaldehyde (4) with bromotriphenylphosphonylmethylpyrazole derivatives 9a,b to give the new quinoline derivatives 10a,b which in turn reacted with different aryl amines to afford 11a-g and 12a-g. Pyrazole derivatives 9a,b were obtained by the reaction of hydroxymethylpyrazole derivatives 8a,b with triphenylphosphine hydrobromide. Antimicrobial evaluation of the newly synthesized compounds showed that most of the new compounds appeared active toward Gram-positive bacteria more than Gram-negative bacteria. The biological evaluation of compounds 12d-g displayed the highest antimicrobial activity against the tested microorganism strains. Additionally, compounds 12d and 12f showed excellent activity against P. aeruginosa (MIC₅₀ 0.019 mg/mL), while compounds 11d, 11f, 12e, and 12g displayed good activity against the same microorganism (MIC₅₀ 0.07 mg/mL). On the other hand, most of the new compounds have moderate activity against E. coli. Compounds 12d and 12f showed excellent activity versus C. albicans in vitro antifungal activity (MIC₅₀ 0.15 mg/mL) comparing to or slightly lower than that of Fluconazole. Using molecular docking simulations, we evaluated the binding affinities and interactions of four chosen derivatives 12d-g with a target PDB code 3WT0 protein.

Due to its adjustable pore structure, the metal–organic frameworks (MOFs) have attracted much attention in the treatment of organic dye molecules in wastewater. However, the general tuning of the pore channels of MOFs is mainly by changing the chain length of the organic ligands and metal nodes. This approach not only limits the types of MOFs, but also limits the treatment of a large number of dye methylene blue (MB) and methyl orange (MO) dye molecules in the wastewater. Hence, we synthesized photoresponsive Zn-AzDC/TPA MOF as adsorbents to adsorb and release organic dye molecules in a photo-controlled manner. The photoresponsive Zn-AzDC/TPA was prepared using a mixed ligand strategy, in which the azobenzene carboxylic acid derivative (AzDC) served as a photoresponsive ligand and terephthalic acid (TPA) served as a non-active ligand in coordination with zinc ion. The optical and structural properties of the synthesized Zn-AzDC/TPA was characterized by UV–vis, FT-IR, PXRD, SEM, TEM, TGA, and pore analysis. Interestingly, it was found that the photoresponsive AzDC unit of Zn-AzDC/TPA demonstrated reversible trans–cis isomerization under the alternating UV and visible light, resulting in reversible changes in the pore size of the Zn-AzDC/TPA. Its photoresponse properties can trapp and release dye molecules under light-driven conditions. This result provides a new direction for the application of photoresponsive MOF and also lays a foundation for the study of diversified optically responsive materials.

Here, we have synthesized Polycalix[4]resorcinarene (PC4RA) covalently coupled with carbon-modified porous graphitic carbon nitride (g-C₃N₄). The nanocomposites were characterized by (FTIR), (XRD), (SEM), Transmission (TEM), and DRS–UV–Vis spectroscopic methods. Photocatalytic activities of the PC4RA/g-C₃N₄ nanocomposites with different ratios of g-C₃N₄ were evaluated for degradation of 4-Nitrophenol under visible light irradiation under light irradiation of λ ≥ 320 nm. Three parameters were applied including the initial concentration of 4-nitrophenol, the amount of photocatalyst, and irradiation time. and the results of the photocatalytic performance suggest that the catalytic activity is strongly influenced by the presence of the g-C₃N₄ content. Especially the nanocomposite’s photocatalytic efficiency was the highest (98.32 % after 120 min) when the ratio of g-C₃N₄ was (1/2). However, an increase of the photocatalytic activities was related to the interfacial transfer of photogenerated electrons and holes, leading to the effective charge separation. The durability and stability of the nanocomposites have been examined and can endure the experimental conditions even after eight successive cycles. This approach opens up an avenue for the fabrication of graphitic carbon nitrite-based metal-free heterogeneous nanocomposites with high catalytic performance.

This method of sustainable synthesis utilizes a range of aromatic/heterocyclic aldehydes, phenylhydrazine, and ethyl acetoacetates. The TiO₂ nanoparticle catalyst facilitates cyclization reactions, yielding pyrazolone derivatives with exceptional efficiency (95–97 %) under reflux conditions at 80 °C. The current method achieves high yields of the corresponding cyclo-products in a short reaction time. A variety of physicochemical methods were employed to ascertain the chemical characteristics and structure of the synthesized heterocycles, and the geometrical structure of the well-crystallized compound (Z)-4-((5-bromofuran-2-yl)methylene)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one was characterized by the use of single-crystal X-ray diffraction measurement. The morphology and elemental composition of TiO₂ nanoparticles were examined using SEM/EDX before and after the model reaction. A drop in the Ti (titanium) signal following the reaction indicates surface alterations. The present process provides a new and improved synthesis process for the formation of pyrazolones that is more convenient, well organized in terms of good yields, a simple handling procedure, a short reaction time, and user-friendliness compared to other surviving procedures. One of the synthesized compounds, (Z)-4-((5-bromofuran-2-yl)methylene)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (2), exhibited significant DNA binding activity. This was further confirmed by a molecular docking study, which revealed a binding energy of −7.2 kcal/mol, and by analyzing the mode of interaction.

The widespread use and subsequent accumulation of florfenicol (FFC), a common antibiotic, through the food chain poses significant risks to aquatic ecosystems and human health, necessitating effective strategies for its removal from water bodies. To solve the challenge, herein, we developed a novel aluminum-based metal–organic framework CAU-1, engineered for the efficient adsorption of FFC. CAU-1 contains the plentiful –NH₂ and μ-OH groups with the positively charged on the surface. In the adsorption process, CAU-1 perform hydrogen bonding interactions with FFC’s functional groups (−F, –OH, −Cl, –NH–, and −SO₂–). Furthermore, the positively charged surface of CAU-1 enhances FFC adsorption via electrostatic attraction together. FFC adsorption equilibrium on CAU-1 is attained within 180 min with a monolayer adsorption capacity of 386 mg/g at 303 K, surpassing most of the reported adsorbents. The exothermic FFC adsorption process on CAU-1 remains largely unaffected by coexisting ions. Additionally, CAU-1 can be efficiently regenerated using a mixed solution of 0.1 M HCl and ethanol–water as an eluent. This work highlights CAU-1’s potential as an effective adsorbent for FFC removal, emphasizing the importance of tuning or designing surface functional groups on adsorbents to boost their adsorption capabilities.

Plywood is widely used in flooring, furniture and other indoor wood products due to its natural advantages. However, due to the rich nutrients and unique properties of plywood, it is easy to harbor mold, which affects the use value of plywood and endangers people’s health. In this paper, ZnO/TiO2 nanoparticles were prepared by a one-pot hydrothermal method, and plywood with anti-mold/anti-bacterial properties was successfully prepared. This study pioneered the novelty and originality of growing inorganic nanocomposites on the surface of plywood to prepare plywood with anti-mold and antimicrobial properties. The prepared samples were characterized by SEM, FTIR, XRD and XPS, and the results showed that ZnO/TiO2 was adsorbed on the surface of plywood by physical adsorption. The results of mold resistance and antimicrobial testing showed that ZnO/TiO2@plywood exhibited excellent performance as the content of ZnO/TiO2 nanoparticles increased. Moreover, the antibacterial rates of ZnO/TiO₂@plywood against staphylococcus aureus and escherichia coli were 96.14% and 93.36%, respectively. The improvement in the anti-mold/anti-bacterial properties of plywood is due to the reaction of ZnO/TiO2 nanoparticles with water or dissolved oxygen in water to form electron-hole pairs, generating chemically active superoxide anion radicals and hydroxyl radicals. These radicals will directly attack the bacterial cells, leading to the degradation of organic matter in the bacterial cells, thus achieving the anti-mold/anti-bacterial effect. Therefore, the novel plywood with anti-mold/anti-bacterial properties prepared in this study will fundamentally improve the intrinsic properties of plywood.

FeNbO₄ monoclinic nanocomposite semiconductors were synthesised using hydrothermal and sol gel methods; photocatalysts were then calcined at 800 °C. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy (UV/Vis) and X-ray diffraction (XRD) technologies were used to investigate crystallinity, morphology and optical properties of the photocatalysts. Fourier transform infrared spectroscopy (FTIR) was used to determine the functional groups of both treated and untreated FeNbO₄. It was found that the S. molle extract-treated FeNbO₄ prepared using the hydrothermal method (FeNbO₄-HT + S. molle) has the smallest nanoparticles (22.8 nm) with the smallest band gap energy (2.78 eV). X-ray photoelectron spectroscopy verified the presence of the elements of FeNbO₄ as well as their oxidation states. The photodegradation reactions of 10-ppm methyl orange dye solutions using FeNbO₄-sol gel, FeNbO₄-HT and FeNbO₄-HT + S. molle were carried out under visible light (>420 nm) for 50 min. The reactions resulted in degradation percent of 74 %, 78 % and 96 % by using FeNbO₄-sol gel, FeNbO₄-HT and FeNbO₄-HT + S. molle respectively. The photocatalytic activity of FeNbO₄ treated with S. molle extract demonstrated superior light absorption and photostability, which is attributed to the consistency in the photocatalysts’ morphology, optical band gap, particle size distribution, and porosity. The photocatalysts remained stable and effective for five degradation cycles.

A simple method for Michael addition at C-5 of Camptothecin has been developed to construct 5-CPT derivatives. The addition products were obtained with moderate yields, and the structures of the target compounds were characterized by ¹H NMR, ¹³C NMR, and HRMS spectra. The feasibility of various Michael addition acceptors for this reaction has also been investigated.

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.

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.