Arabian Journal of Chemistry最新文献

This work presents an advanced automated monolithic C18 pipette-tip solid-phase extraction (PT-SPE) method seamlessly integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for precise therapeutic drug monitoring of eleven tyrosine kinase inhibitors (TKIs) in biological samples. Commercially available MonoTip C18 columns facilitate superior extraction efficiency and selectivity from complex biological matrices owing to their large surface areas and enhanced mass transfer capabilities. The sample preparation process, conducted by aspirating and dispensing solutions using a pipettor, completes the overall extraction process within 3 min. The method validation demonstrated excellent linearity within the range of 0.2/0.5/0.8 to 200 ng/mL, with detection limits ranging from 0.049 to 0.206 ng/mL. The method exhibited outstanding accuracy and precision, with intraday relative recovery rates ranging from 96.3 % to 115.0 % and interday recovery rates ranging from 95.0 % to 115.7 %, with coefficient of variation values consistently below 13.8 %. The proposed method is distinguished by its exceptional efficiency, reduced solvent use, enhanced environmental sustainability, and streamlined automation—key advantages in the realm of clinical therapeutic drug monitoring of TKIs. Overall, the MonoTip C18 PT-SPE technique, coupled with LC-MS/MS, offers a formidable, eco-friendly, and effective strategy for the TDM of TKIs, marking a significant advancement in the field.

The utilization of renewable solar energy for the photocatalytic transformation of carbon dioxide (CO₂) into valuable chemical substances is considered an optimal strategy to simultaneously address climate challenges and tackle energy scarcity. Herein, we prepared heterojunction photocatalysts UiO-66-NH₂/ZnIn₂S₄, which were successfully applied in the photocatalytic reduction of CO₂. The yield of the main product CO, for the optimal UiO-66-NH₂/ZnIn₂S₄-2 sample could reach up to 57 μmol g⁻¹h⁻¹ when converting CO₂ under the visible light irradiation, which was approximately 3.35 and 2.71 times higher than that achieved by the individual UiO-66-NH₂ and ZnIn₂S₄ samples, respectively. The better photocatalytic performance of the UiO-66-NH₂/ZnIn₂S₄-2 composites can be attributed to its synergistic effect resulting from tight interfacial contacts, special charge transfer pathways and excellent CO₂ adsorption capacity. Furthermore, the intimate contact between UiO-66-NH₂ and flower-like ZnIn₂S₄ accelerates electron transmission while effectively suppressing the quenching of photogenerated carriers. This research provides vital knowledge for the rational design of heterostructures aimed at enhancing the efficiency of CO₂ photocatalysis for solar fuel production.

A novel bio-covalent organic framework (COF: TpPa-SO₃H/Lignin) based on TpPa-SO₃H and lignin from lignocellulose was synthesized for chromium (Cr(VI)) remediation in this study. Results showed that TpPa-SO₃H/Lignin had a highest adsorption capacity at the range of 5 ∼ 75 mg/L Cr(VI) under 10 mg/L dosage, in which 100 % Cr(VI) could be removal within 120 min. Likewise, the introduction of lignin improved the visible light response range, charge separation and photogenerated carriers, thereby improving the photocatalytic efficiency of Cr(VI) by TpPa-SO₃H/Lignin. The highest photocatalytic efficiency of TpPa-SO₃H/Lignin (98.56 %) was observed at the acidic conditions. ESR result shows that e- and ·O₂^– are generated and played an important role during the photocatalytic reaction, while the contribution of ·OH to Cr(VI) photoreduction is negligible. This study presents a sustainable and efficient approach to mitigating Cr(VI) pollution. It opens up avenues for further exploration of lignocellulose-derived materials in environmental applications and highlights the potential of COFs in addressing heavy metal contaminants.

Uncontrolled activation of c-Kit is closely related to the pathogenesis and progression of leukemia, gastrointestinal cancer, and other malignant diseases. Although there are several inhibitors available, due to the limitation of selectivity and the unfavorable side effects, designing and discovering highly selective inhibitors targeting c-Kit kinase, especially the gain of function mutation (for example c-Kit D816V), is still necessary. To identify novel c-Kit inhibitors, a metastable state-based virtual screening approach, which was successfully implemented in other kinase inhibitors, was employed in the current study. The results from our current study demonstrated the residues adjacent to the DFG motif within the activation loop could fold into short α-helices aside from the random coil, which was commonly found in the crystal structure. By expanding the conformation pool of the activation loop via PyRosetta-based ab initio folding protocol, we constructed a series of structural models of the c-Kit kinase intermediate between the inactive and active states. After evaluation of the thermal stability of the metastable state with molecular dynamics simulation, one structural model showed higher stability of α-helix, and the activation loop was retained. Considering the wild-type and D816V mutated KIT kinase shared similar metastable states during the kinase activation process, we developed a hypothesis that the identified intermediate might hold the potential to identify inhibitors targeting D816V mutations from the compound database. As expected, the intermediate structure showed higher selectivity to KIT D816V selective inhibitors, such as bezuclastinib, avapritinib, BLU-263, and elenestinib, than imatinib or masitinib. The virtual screening of the available KIT kinase inhibitor database further identified vorolanib, semaxanib, henatinib, and pexmetinib may possess potential inhibitory effects against wild type, as well as the mutated c-Kit kinase. The results from our current study not only proposed a novel structural model that could be used for the identification of selective c-Kit D816V inhibitors but also identified several potential inhibitors from available kinase inhibitors, which might shed new light on the design of new therapeutic approaches for c-Kit mutation-driven malignant diseases.

Utilizing synthetic insecticides to control mosquito populations has many adverse side effects as they can cause environmental pollution and insecticide resistance. Therefore, the search for eco-friendly and effective mosquito control agents has led to the exploration of plant extracts with larvicidal efficacy. In this study, we aimed to explore the larvicidal activity of four Egyptian plant extracts: Rosmarinus officinalis, Melissa officinalis, Cichorium intybus, and Beta vulgaris var. cicla against Culex pipiens and to identify the chemical constituents present in the active extracts. The methanolic extracts of the four plants were prepared and tested against the third instar larvae of C. pipiens using a standard method. The lethal concentrations (LC₅₀ and LC₉₀) were calculated using probit analysis. The active extracts were subjected to ultra-performance liquid chromatography-mass spectroscopy (UPLC-MS/MS) analysis and the data were processed using the global natural products social molecular networking (GNPS) platform to generate molecular networks and identify the compounds based on spectral similarity and database matching. The methanolic extracts of R. officinalis L. and M. officinalis L. had the highest larvicidal activity, where LC₅₀ values were 9.795 and 26.505 μg/mL, respectively. Their exposure caused a high mortality rate and disrupted the biochemical and physiological parameters (total carbohydrates, total lipids, total protein, acetylcholinesterase (AChE), and glutathione S-transferase (GST) in the body of C. pipiens when compared with Cichorium intybus (Chicory) and Beta vulgaris var. cicla (Chard). The UPLC-MS/MS analysis with the aid of the GNPS platform, revealed the presence of 23 and 41 metabolites from R. officinalis L. and M. officinalis L., respectively. The identified metabolites may act as larvicidal agents by interfering with the physiological or biochemical processes of the mosquito larvae. Overall, the findings suggest that the methanolic extracts of R. officinalis and M. officinalis are potential sources of natural larvicides for mosquito control.

In this research work, we designed a smart biodegradable PEG-coated MnO₂ nanoparticles conjugated with doxorubicin (PMnO₂-Dox NPs) for dual chemo-photodynamic therapy and magnetic resonance imaging (MRI) application. This highly sensitive pH-responsive PMnO₂-Dox NPs causes effective drug release under acidic pH environment. PMnO₂-Dox NPs not only improves the efficacy of chemo-photodynamic therapy due to synergistic response as well as improved MRI imaging via boosting T₁ MRI contrast. Manifold characterization techniques have been employed for materials investigation. Crystallography of PMnO₂-Dox NPs were performed by using XRD analysis, which confirmed tetragonal crystal structure with an approximate crystallite size of 20–30 nm. Surface morphology was confirmed via SEM analysis, results indicated the spherical and asymmetric agglomerated nanocluster of PMnO₂-Dox NPs. In in vitro bioassay, the anticancer activity of PMnO₂-Dox NPs were tested against breast cancer (MCF-7) cell line using MTT test. Moreover, it can also inhibit the growth of primary and secondary cancers without light exposure. Results suggested that PMnO₂-Dox NPs not only convenient for cancer treatment via combined chemo-photodynamic therapy but also address the way towards a comprehensive strategy for MRI application via bright contrast agent T1 after overcoming the problem of multidrug resistance (MDR) and synergistic response of therapeutic analysis.

Industrial wastewater treatment increasingly relies on membrane separation, with ceramic membranes offering many advantages such as thermal stability and pH resistance. The resistance of ceramic membranes to extreme pH conditions indicates their ability to maintain structure and performance when exposed to highly acidic or alkaline environments. A high-permeability ceramic nanofiltration membrane was developed, boasting excellent rejection rates through a multilayer asymmetric design. Initially, two tubular porous supports, mullite and mullite-alumina, with a weight percent of 50, were fabricated using the extrusion method. Subsequently, a colloidal sol of titania (TiO₂) and titania-zirconia (TiO₂- ZrO₂) was prepared via the sol–gel method and coated on the ceramic supports using the dip-coating method. After analyzing the membrane microstructure using SEM, XRD, and BET, the efficiency of the membranes in treating synthetic oily wastewater was evaluated. The results underscore the significant impact of the Donnan exclusion mechanism on the rejection of nanofiltration (NF) membranes. An increase in pressure led to a rise in rejection rates up to 7 bars. The Chemical Oxygen Demand (COD) rejection for mullite-titania zirconia (MTZ) and mullite-alumina-titania zirconia (MATZ) membranes was 98.65 % and 98 %, respectively. The pure water permeability test results for mullite and mullite-alumina supports, as well as MTZ and MATZ membranes, were recorded as 254, 382, 70, and 89 L bar^-1m^-2h⁻¹, respectively.

The abuse of oxytetracycline (OTC) leaves serious environmental residues and triggers accumulation in organisms, constituting a threat to human health. Constructing an effective platform based on dual-functional materials for monitoring and removing OTC residues is a preferable solution. Herein, we proposed a novel composite material by doping carbon dots (CDs) into melamine–formaldehyde microsphere (MFM) through a one-pot method and named CDs@MFM, which inherited the fluorescence property of CDs and porous structure of MFM simultaneously. CDs@MFM demonstrated dual functions for the detection and removal of OTC concurrently within a few minutes, with its performance compared in detail with bare CDs and MFM as controls. By virtue of the pre-enrichment effect attributed to its porous structure, CDs@MFM exhibited a lower detection limit for OTC than bare CDs (0.027 mg/L vs 0.067 mg/L) and a higher adsorption capacity than MFM (73.01 mg/g vs 68.76 mg/g) resulting from more affiliated functional groups available for OTC provided by the CDs. Overall, CDs@MFM has proven to be an efficient and convenient candidate capable of monitoring and removing OTC synchronously, and this work offers an avenue for the design of dual-functional materials in the field of environmental science.

Hydrogels are three-dimensional structures that serve as substitutes for the extracellular matrix (ECM) and possess outstanding physicochemical and biochemical characteristics. They are gaining importance in regenerative medicine because of their similarity to the natural extracellular matrix in terms of moisture content and wound and tissue healing permeability. Tissue engineering advancements have resulted in the development of flexible hydrogels that mimic the dynamic characteristics of the ECM. Several approaches have been applied to produce hydrogels from biopolymers with enhanced functional and structural characteristics for different applications in tissue engineering and regenerative medicine (TERM). This review provides a comprehensive overview of hydrogel in wound healing, tissue engineering, and drug delivery systems. We outline different types of hydrogels based on the physical and chemical crosslinking, fundamental properties, and their applications in TERM. This review article provided the recent literature on hydrogels for tissue engineering and regenerative medicine within five years. Recent developments in biopolymer-based hydrogels for state-of-the-art tissue engineering and regenerative medicine have been discussed, emphasizing their significant challenges and future perspectives.

Cyclodextrins (CDs) are essential compounds because of their wide applications in many fields. They are cyclic oligosaccharides with lipophilic internal cavities and hydrophilic external surfaces that link the α-D-glucopyranose portion. β-Cyclodextrin (β-CD) is a non-toxicity, cheap, green, and renewability macrocycle with excellent performance in organic transformation. β-CD is a green catalyst with satisfactory catalytic activity in diverse organic changes. Regarding green chemistry’s goals, β-CD opens the way to effective catalysts for various reactions. Heterocyclic compounds are among the most prominent organic compounds in numerous organic materials, pharmaceuticals, and natural products. Heterocyclic compounds are essential in pharmaceutical products and show different biological activities in multiple illnesses. Thus, there is a tendency to develop novel, green, and helpful syntheses of heterocyclic systems, which has been a big challenge in synthetic organic chemistry. Using β-CD as catalysts for synthesizing heterocyclic compounds makes the procedure milder, easier, and less toxic, making it an eco-friendly substitute compared to the reported approaches. This review underlines the applications of β-CD-based catalysts for synthesizing heterocyclic compounds covering 2019–2023. This study will be helpful to researchers in the investigation areas of organic synthesis, medicinal chemistry, synthetic materials, and pharmacological medicine..