Journal of Saudi Chemical Society最新文献

This study introduces MnFe₂O₄@SiO₂-SiO₃H as a novel magnetic catalyst and thoroughly investigates its structure, catalytic activity, and reusability. The synthesis of the magnetic catalyst was meticulously characterized using an array of analytical techniques. Utilizing MnFe₂O₄@SiO₂-SiO₃H, the synthesis of functionalized oxazolidine-2-ones were performed, versatile compounds widely employed in chiral auxiliaries, protecting groups, and medicinal chemistry. Remarkably, the two-step process from chalcones demonstrated one of the shortest reported pathways, highlighting the efficiency of our novel nanocatalyst. To elucidate the stability and reactivity of the synthesized products, we employed Density Functional Theory (DFT) calculations, including molecular electrostatic potential (MEP) mapping and reactivity indices such as electronegativity, electrophilic index, softness, and hardness, as well as frontier molecular orbitals (HOMO-LUMO). Furthermore, our investigations extended to the recycling capabilities of the nanocatalyst. Through a comprehensive evaluation of at least five reaction cycles, MnFe₂O₄@SiO₂-SiO₃H showcased a remarkable retention of activity (97–92 %), reaffirming its reusability and long-term potential. Our research presents MnFe₂O₄@SiO₂-SiO₃H as a highly effective and recoverable nanomagnetic catalyst for organic reactions, with demonstrated applications in synthesizing functionalized oxazolidine-2-ones. As such, our findings offer a promising alternative to traditional methods, presenting new opportunities in catalysis and materials science.

The designed and synthesized multifunctional properties of bis-hydrazono[1,3,4]thiadiazoles became important for developing an efficient medication for Alzheimer’s disease. Thiadiazoles were characterized and studied towards this target as an acetylcholinesterase inhibitor (ChEIs). In this study, one-pot synthetic strategy was applied for the synthesis of bis-hydrazono[1,3,4]thiadiazole series from 2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbodithioic acid) and hydrazonoyl chlorides. The greener pastures, in silico, an environmentally-friendly and free computer-aided method, bioactivity studies of the bis-hydrazono[1,3,4]thiadiazoles 4a-h exhibited various possible interesting inhibitory activities against AChE showing similar behaviour to the approved drugs, Donepezil, Galantamine and Rivastigmine. For a fair comparison, the superpositions of 4a-h, and Donepezil, Galantamine and Rivastigmine docked together into the functional domain (binding pocket) of 1EVE to reveal interesting different molecular laydowns of the compounds. On the other side, the display of the molecules before and after docking was discussed. The binding affinity slightly differs between Donepezil, Galantamine, Rivastigmine, and the ligands 4a-h. The range of the recorded binding affinity for 4a-h is from (−9.4 to −8.4 kcal/mol⁻¹)^, whereas the binding affinity for Donepezil, Galantamine and Rivastigmine is (−11.1, −9.8 and −8.0 kcal/mol⁻¹ respectively), which is higher than all the prepared ligands.

Furthermore, the binding amino acids also varied among the studied compounds in this study. Phe290, Phe330, Phe331, Trp279, Tyr70, Tyr121 and Tyr334 are the common amino acids binding with the FDA-approved AChE inhibitors for treating AD, Donepezil, Galantamine and Rivastigmine and ligands. Notably, the number of hydrophobic and hydrogen interactions studied between the ligands 4a-h and the Donepezil, Galantamine and Rivastigmine drugs were compared as a preliminary indicator towards a successful inhibitor. The comparative study in this research work aims to rank our compounds with respect to the approved medications. This is a friendly environmental preliminary helpful indication before leaping into time and energy-consuming experimental work. Organ toxicological endpoints and toxicity-predicted activity were obtained using the ProTox-II web server for both the approved medication and ligands. Later, in-vitro acetylcholinesterase inhibition assays were conducted to assess the efficacy of bis-hydrazono[1,3,4]thiadiazoles 4a-h as inhibitors of acetylcholinesterase (AChE) in comparison to Donepezil. Results indicated promising inhibition activities for example 4 h, 4 g and 4d to the testing drug Donepezil for breaking down the neurotransmitter acetylcholine.

The primary objective of this research endeavor is to develop a highly sensitive and selective electrochemical sensor for the accurate detection of hydroquinone (HQ), a prevalent environmental contaminant. To achieve this, we employed a novel nanocomposite consisting of Ga₂O₃-doped ZnO (Ga₂O₃.ZnO) as the active nanomaterial for fabricating a glassy carbon electrode (GCE). The structure and morphology of the Ga₂O₃.ZnO nanocomposite were rigorously analyzed using a diverse range of techniques to ensure its suitability as the sensing nanomaterial. This innovative sensor exhibits remarkable capabilities, enabling the detection of HQ across a broad concentration range, spanning from 1 to 11070 µM, in a neutral phosphate buffer solution. It boasts an exceptionally high sensitivity of 1.0229 µA µM⁻¹ cm⁻² and an impressive detection limit of 0.063 µM. Thanks to its exceptional sensitivity and specificity, this sensor can precisely quantify HQ levels in real-world samples. Moreover, its outstanding reproducibility, repeatability, and stability establish it as a dependable and resilient choice for HQ determination.

The release rate and time are very important for the drug carriers, silica aerogel filled hydroxypropyl cellulose/chitosan (SA/HPC/CS) composites were fabricated for the release of 5-fluorouracil (5-Fu), and the release rate and time were regulated with the content of SA, pH value and external coating material. Firstly, the 5-Fu loaded SA/HPC/CS composites and Eudragit L100 coated composites were prepared with cross-linking followed by freeze-drying, and characterized by SEM, FTIR, XRD, DSC, and TG. Then, the effect of SA content on the encapsulation efficiency of SA/HPC/CS@5-Fu was investigated, and 5-Fu release behavior under different pH values from these aerogel composites was evaluated with four kinetic models. In addition, to further solve the abrupt effect of the obtained composites, Eudragit L100 coated SA/HPC/CS@5-Fu was fabricated, the sustained release behavior revealed that the coating technique can effectively improve the release behavior and extend release time.

In this article, Persea americana aqueous peels extract was used to synthesize silver nanoparticles in a simple and environmentally friendly manner. The properties of synthesized silver nanoparticles (AV-AgNPs) were studied via several techniques, including UV–vis spectroscopy, DLS, TEM, EDX, and FTIR. The UV–Vis spectra analysis revealed that the highest absorption peak occurred at 428 nm, providing strong evidence for forming AV-AgNPs. The TEM results indicate that the synthesized AV-AgNPs were uniformly dispersed, exhibiting a spherical shape with an average size of 24 nm. EDX imaging also confirmed the presence of AgNPs. FTIR analysis shows P. americana's phenolic compounds and proteins significantly contribute to AV-AgNP synthesis and stabilization. In addition, the antimicrobial activity of AV-AgNPs was assessed against pathogenic bacteria commonly found in humans, exhibiting a moderate zone of inhibition against the selected pathogens. Additionally, AV-AgNPs were used in antioxidant studies with the robust antioxidant properties 2, 2 diphenyl-1-picrylhydrazyl (DPPH). In vitro studies have shown that AV-AgNPs can remarkably inhibit α-amylase in a dose-dependent manner, indicating their potential as antidiabetic agents. In silico research, it was revealed that naringenin derived from P. americana exhibited a strong binding to S. typhi and B. cereus (−8.7 and −7.5 kcal/mol, respectively). At the same time, quercetin demonstrated a high binding affinity and energy to α-Amylase (−8.9 kcal/mol). This study presents the first investigation into the biosynthesis of AgNPs utilizing the aqueous peel extract derived from P. americana with multiple uses, including antioxidant, antimicrobial, and antidiabetic activity.

Traditional molecular recognition studies usually focus on obtaining strong host–guest interactions, which may lead to the neglect of important tendencies caused by other factors. Moreover, most receptors typically fix their recognition sites in the backbone of the receptor, resulting in great synthetic challenges for varying recognition functional groups. In this contribution, we developed a new class of tetrapodal receptors. The terminal functional groups of the receptor can be varied by simple chemistry. Through ¹H NMR titration experiments and binding constant analysis, the influence of the size and shape of alkane chains on monosaccharide recognition was investigated. The introduction of ester functional groups allows the access of moderate binding affinity to unveil otherwise masked contribution of dispersion force in saccharide recognition. These results also imply that stronger forces may not always be beneficial for host–guest binding while functional groups with a particular shape may favor the discrimination of isomers through steric hindrance effect. Thereby, these tetrapodal receptors and their analogues provide an ideal platform for comparing the effects of various functional groups on molecular recognition.

Converting waste fish bones into bioactive materials presents an innovative and eco-friendly approach to materials science. Fish bones, often discarded as waste in the seafood industry, are rich in calcium (Ca) and phosphorous (P), making them ideal precursors for Calcium phosphate (CaP) materials. In this study, different kinds of CaP materials were successfully extracted from diverse fish bone types like Carp fish (CF), Atlantic bonito (AB) and Gilt-head bream (GB) using a heat treatment method. The extracted white powders were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Transmission electron microscopy (TEM), and Inductively coupled plasma mass spectrometry (ICP-MS) techniques and the outcomes compared the most popular phase of CaP material like β -tricalcium phosphate (β-TCP) and Hydroxyapatite (HA) which they are synthesized using microwave refluxing equipment. The XRD pattern of the CF sample closely corresponded with the HA phase, while the AB and GB samples aligned with the biphasic calcium phosphate (HA/β-TCP) phase. The FTIR spectra analysis identified the presence of phosphate, hydroxyl, and carbonate groups. The XPS spectra determined the Ca/P ratio to range between 1.32 and 1.57. In vitro degradation studies were performed in phosphate-buffered saline (PBS) at 37 °C over 1, 3, 7, and 14 days. The ion release profiles of Ca²⁺ and P⁵⁺ were monitored, revealing the most significant degradation rate occurred between 7 and 14 days. The highest leaching levels of Ca ions were observed in the AB fish bones, with concentrations reaching approximately 87.35 mg/L after 14 days of immersion. Based on the results, it is concluded that the biphasic calcium phosphate derived from AB, along with its Ca, P, and other minerals content, exhibits a higher degradation rate than other samples. This indicates its potential as a promising bioactive material suitable for use as a bone tissue substitute.

This study reports the production of a heterojunction copper oxide-zinc oxide nano-photocatalyst based on lemon leaf extract, which acted as both a stabilizer and a capping and reducing agent. The fabricated photocatalyst had a smooth surface with numerous functional groups, and its energy band gap was measured to be 3.14 eV, which is suitable for photocatalytic applications. Toxic Congo Red dye was used as a model pollutant to investigate the photocatalytic degradation performance of the proposed CuO-ZnO nano-photocatalyst. The photocatalyst exhibited a rapid degradation rate under sunlight irradiation, reducing the concentration of the dye by almost 70 % within 50 min and exhibited pseudo-first-order kinetics. The performance of the photocatalyst was also evaluated based on its quantum yield and figure of merit, which were found to be 6.63 x 10⁻⁹ molecules photon⁻¹and 3.31 x 10⁻⁴, respectively. In addition, the proposed catalyst displayed good stability for up to 5 cycles. Based on these results, the fabricated CuO-ZnO nano-photocatalyst outperformed previously reported photocatalysts. The mechanisms associated with the dye degradation were also explained by an interfacial charge transfer reaction.

Structural diversity guided steroidal thiazolidin-4-one conjugates were designed and synthesized based on six steroid skeletons mainly including androst-4-ene-3,17-dione, dehydroepiandrosterone, epiandrosterone, androst-1,4-diene-3,17-dione, dienedione and 9α-hydroxy-androst-4-ene-3,17-dione. Their in vitro inhibition activities against cell proliferation were fully investigated, and some of which exhibited good antiproliferative activities as potential CDK1 inhibitor. The detailed analysis of structure–activity relationships (SARs) based on the inhibition activities, kinase assay, and molecular docking model demonstrated that the structure of different steroidal core ring skeleton as well as the N substituents of the thiazolidin-4-one ring influenced the inhibitory activity on cancer cell lines. Especially, compounds 15c and 16c have certain inhibitory effects on the tyrosine protein kinases CDK1/CyclinA2, ALK, CDK6/CyclinD1, FGFR1 and PIM2. Compounds 16c displayed highest inhibitory effect on the kinases of CDK1/CyclinA2 with inhibition rate 56.38 % at the concentration of 10 μM, which induced cell death in A875 cells at least partly (initially), by apoptosis.

M-cresol, one of phenolics, is highly toxic, refractory, and threatens human health and ecological safety. The study on the efficient m-cresol degradation technologies is crucial and helpful to restrain its discharge into water body. A composite of MnO-doped red mud (RM) to activate peroxymonosulfate (PMS) for the m-cresol degradation was fabricated and employed, favorable to the recycling and utilization of RM. Considering the catalytic activity and cost, 0.1 M/RM@G exhibited an excellent degradation capacity attributing to strong Fe₃O₄ and MnO synergy and was considered as the best catalyst among the investigative catalysts. 100 % of m-cresol and 71.4 % of COD could be degraded within 90 min under 2 g/L catalyst, 10 mM of PMS, 3-8 of initial pH and 50 mg/L m-cresol in the 0.1 M/RM@G/PMS system. The reaction rate constant (0.045 min⁻¹) of 0.1 M/RM@G was much larger than RM@G (0.012 min⁻¹), ARM (0.0048 min⁻¹) and WRM (0.0028 min⁻¹). Main Mn and Fe active components and abundant mesoporous structures on the catalyst surface could efficiently drove electron transfers, and further accelerated the redox cycles of Mn(III)Mn(II) and Fe(III)Fe(II) for activating PMS. ¹O₂ played a crucial role in degrading m-cresol. Based on the experiment data, the generation mechanism of radicals and the possible pathways of m-cresol degradation were proposed in the 0.1 M/RM@G/PMS system. This finding provides a new way for the synthesis of the efficient catalyst with RM and optimal operating strategies for the treatment of m-cresol wastewater.