ChemistrySelect最新文献

Waste cooking oils are commonly utilized as feedstock in biodiesel synthesis. However, there has been limited research on the perspective of using waste cooking olive oil for biodiesel production. This study explores the potential of household waste frying olive oil as a feedstock for biodiesel production andcomparing it with sunflower oil. The biodiesel samples were evaluated according to European standard specifications and test methods EN 14214. However, the water content and oxidation stability did not meet the required criteria. To address this, the Rancimat method was used to investigate the potential of essential oils and plant extracts as antioxidants. Oregano essential oil and rosemary plant extracts significantly improved the oxidation stability of both olive and sunflower oil biodiesel. The analysis of the fatty acid profile of the feedstock through gas chromatography–mass spectrometry proved to be a critical determinant of biodiesel properties. Moreover, the use of ultrasound-assisted biodiesel synthesis enhanced the yield of biodiesel. The research findings have indicated that olive oil is a sustainable option to produce high-yield biodiesel with a noteworthy antioxidant stability when natural antioxidants are incorporated into the mixture.

A ratio fluorescent sensor N'-((E)-3-((E)-((3′, 6′-bis(diethylamino)-3-oxospiro[isoindoline-1, 9′-xanthen]-2-yl)imino)methyl)-2-hydroxy-5-methylbenzylidene)-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (I) based on the FRET mechanism was synthesized using coumarin as the donor and rhodamine as the receptor. Its structure was characterized by FT-IR, ¹H NMR, ¹³C NMR, and ESI-MS. The sensing performance of sensor I was studied using fluorescence spectrophotometry, and the detection mechanism was studied using density functional theory. The results indicated that in MeOH/H₂O medium, sensor I exhibits a significant fluorescence enhanced response to Al³⁺, with a detection limit of 5.8 × 10⁻⁷ mol/L. In addition, complex I-Al³⁺exhibits a significant fluorescence quenching response to PPi, with a detection limit of 3.7 × 10⁻⁷ mol/L, indicating that sensor I has high sensitivity and anti-interference ability for the recognition and detection of Al³⁺ and PPi. Through the analysis of complexation curves, it was found that the complexation ratio of sensor I to Al³⁺ was 1:1 and complex I-Al³⁺ to PPi was 2:1, and the cyclic response test could be performed stably for more than four times. The imaging results of Arabidopsis thaliana show that sensor I has low toxicity and good biocompatibility, which provides a way for the detection of Al³⁺ in plants.

In this study, we have shown for the first time that the introduction of a single alkylamide substituent into the macrocyclic platform of pillar[5]arene opens up the possibility to control the supramolecular properties of this macrocyclic platform. The ability of the synthesized pillar[5]arenes to form supramolecular pseudorotaxane associates both in solutions and in the crystalline state was studied by a complex of physical methods. Linear secondary amide fragments such as N,N-diethylethane-1,2-diamide, N,N-dimethylpropane-1,3-diamide, or N-aminoethylmorpholide in the structure of pillar[5]arene promote the formation of self-inclusion complexes both in solution and crystalline states. Whereas tertiary amides such as pyrrolidide or morpholide moieties favor the formation of supramolecular polymers both in solution and in crystalline states. The obtained results show the prospects for the use of amide fragments in the structures of pillar[n]arenes as customization units for controlling supramolecular self-assembly.

The aim of this project is to investigate host–guest complexes based on pure and doped-BN nanotubes for the treatment of gastric and gastrointestinal cancer. Therefore, in this work, the host–guest complexes obtained from the interaction of pure boron nitride nanotubes (BNNTs) as well as Al and Ga-doped BN nanotubes with the anticancer drugs of Oteracil (OT) and potassium oteracil (OTP) were investigated in the gas phase and water solvent. All calculations were performed at the M06-2X/6–31G(d) level of theory. Interaction energies, structural parameters, topological properties as well as RDG, ELF, and CCD analyses were used to assess the strength of interactions in the complexes. The results show that the doped-BN nanotubes have stronger interactions with OT and OTP drugs. Adsorption energies (ΔEads) reveal that the adsorption tendency of drugs on nanotubes is in the order of BN(Ga) > BN(Al) > pure-BN. The electronic properties of pure and doped-BN nanotubes were investigated and compared before and after the adsorption process. The quantum molecular descriptors were used to investigate the reactivity of pure and doped-BN nanotubes to drugs. The energy gap (Eg) was dramatically changed when the dopant atoms were added to the BN nanotube. Therefore, the impurity can improve the reactivity of the pure BN nanotube. The type of adsorption in pure and doped-BN nanotubes can be physical. Increasing temperature reduces recovery time. Analysis of natural bond orbital (NBO), molecular electrostatic potential surface maps (MESP), and the (RDG) were performed to evaluate the nature of the drug/nanotube intermolecular interactions. Generally, the tendency of Al and Ga-doped nanotubes to absorb OT and OTP drugs is higher than that of pure nanotubes. This study can provide insights into innovation in the design of drug delivery systems.

This study presents a novel approach toward wastewater remediation via the synthesis of a series of coordination polymers that combine benzene-1,4-dicarboxylic acid, benzene-1,4-dihydroxamic acid, and 5-nitroisophthalic acid linkers with Cu, Cr, Ce, and La metal salts to target efficient methylene blue removal. Through a detailed characterization process using techniques like ¹H NMR, PXRD, FTIR, TGA, SEM-EDX, ICP-OES, and BET, the structural and surface properties of these CPs were optimized for stability and enhanced adsorption performance. Notably, the CPs exhibited rapid MB adsorption within 10 min and followed pseudo-second-order kinetics, indicating a chemisorption-driven process. This work advances the field by demonstrating that increased pH significantly improves adsorption capacity and that the Sips model best describes the heterogeneous adsorptive behavior, highlighting a mixed Langmuir–Freundlich mechanism. Furthermore, stability and reusability studies revealed minimal metal leaching in the best-performing CPs, addressing critical environmental concerns around long-term CP use. This integrated approach not only fills vital knowledge gaps in CP-based dye adsorption kinetics but also underscores the potential of these materials as sustainable, scalable, and effective solutions for real-world water treatment applications.

Diabetic wounds are notoriously problematic to heal, often leading to an increased risk of infection with conventional wound dressings. To address this problem, thermosensitive hydrogels (hydrogel TM) loaded with peppermint extracts as antibacterial agents were developed. The objective of this study was to synthesize and optimize the hydrogel TM formulation and to evaluate its efficacy in accelerating diabetic wound healing through integrative in silico, in vitro, and in vivo approaches. The optimal hydrogel TM formulation was determined using response surface methodology (RSM) and peppermint green extraction via ultrasonic-assisted extraction (UAE). Characterization of hydrogel TM was performed using FTIR, TGA-DSC, and SEM, while the peppermint extract was examined by GC/MS. The synthesized hydrogel TM, with optimal formulations of 3.320 %w/v methyl cellulose and 3.671 %w/v trisodium citrate, displayed a gelation temperature of 37 °C. The loading of peppermint extract was proven through a smoother porous structure based on SEM analysis. In silico and in vitro tests demonstrated significant antibacterial activity, and in vivo studies showed complete wound closure within 9 days, proving the efficacy of the hydrogel TM@PM in accelerating diabetic wound healing.

In this research, a magnetic catalyst with immobilized gold nanoparticles (Au NPs) for C─C cross-coupling reactions has been introduced. The catalyst consists of Au NPs immobilized on functionalized poly(N-isopropyl acrylamide) (PNIPAM) grafted to Fe₃O₄ magnetic nanoparticles (MNPs) modified with silica. For the catalyst synthesis, firstly, the Fe₃O₄ MNP core is prepared, modified with silica, coated with PNIPAM, and subsequently functionalized with amino functional group and EDTA. Finally, it is decorated with Au NPs to create the desired catalyst (Fe₃O₄/Si/modified PNIPAM-Au). TEM images of the catalyst confirmed the presence of spherical gold NPs with an approximate size of 13 nm on the catalyst matrix. Also, XPS analysis well proves the presence of zero metallic gold. The catalytic performance of the Au catalyst was evaluated through the C─C coupling transformations, for example, Suzuki–Miyaura, Mizoroki–Heck, and Sonogashira–Hagihara reactions. The results demonstrated significant catalytic activity of the as-synthesized Au catalyst. Using a magnet, the catalyst could be isolated from the reaction mixture and employed again in eight consecutive coupling reactions. During these reactions, some reduction in catalytic efficiency and gold leaching is observed. Overall, this catalyst shows excellent potential for efficient catalytic reactions, offering the advantages of easy separation, recyclability, and high catalytic activity.

Exposure to high amounts of volatile organic compounds (VOC) in the short term can cause headaches, dizziness, worsening asthma symptoms, vomiting, and eye, nose, and throat irritation. Thus, a gas sensor is needed to detect VOC gases. Chitosan as a nonconducting polymer was used as an alternative binder for thick film gas sensors in this study. Chitosan was dissolved in an acetic acid to produce a polymer solution and mixed with graphene nanoflakes to make a graphene gas sensor. Two chitosan binder recipes were used in this study to investigate their performance in gas sensors for the VOCs acetone and ethanol. A single layer and a double layer of graphene were deposited to study their effects on VOC sensing. Single and double layers of graphene gas sensors had little effect on the sensing response to acetone and ethanol vapor. Results revealed that the gas sensors were prepared by binder B responded better than binder A in sensing response to acetone and ethanol with a response value achieved by T2-2-S1(3) and, T2-2-S1(1) with a response value of 1.0579 and, 1.0532, respectively. In addition, chitosan in graphene gas sensors had outstanding performances, in terms of linearity and repeatability characteristics.

The coexistence of Gram-negative organisms, such as Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) in diabetic foot ulcers poses significant therapeutic challenges and increases the rate of treatment failure. By studying the structure-activity relationships of small alkynylphenyl-aminoguanidine molecules, we identified heptyne and octyne derivatives as promising antibacterial agents. These compounds exhibited potent activity against Gram-positive MRSA USA300 (MIC = 0.5 µg/mL) and reasonable activity against Gram-negative A. baumannii AB5075 (MIC = 8 µg/mL). It is noteworthy that octynylphenyl-aminoguanidine demonstrated a rapid bactericidal effect within 2 h and showed no evidence of resistance development. Despite systemic intolerance, topical application of the two most active compounds significantly improved skin condition and reduced bacterial burdens in an murine skin infection model (MRSA). These results highlight a promising therapeutic avenue for MRSA skin infections, with potential efficacy in coinfections with multidrug-resistant Gram-negative pathogens such as A. baumannii.

A highly efficient and environmentally friendly corn straw amphoteric adsorbent (CSAA) was produced using pretreatment, etherification, and graft copolymerization of corn straw (CS) for the purpose of removing methylene blue (MB) and acid red 1 (AR1). The CSAA was subjected to characterize utilizing SEM, FTIR, XRD, Zeta surface potential, and TG. The impacts of pH value, adsorbent dosage, dye concentration, and salt concentration on the adsorption of MB and AR1 by CSAA were examined. The concurrent removal of cationic and anionic dyes under different pH levels has been successfully shown, exhibiting potential utility in dye wastewater. The pseudo-second-order kinetic equation indicated a superior match with the empirical data, suggesting that the principal adsorption mechanism may be attributable to ionic attraction. The equilibrium adsorption isotherm study of the CSAA demonstrated a stronger conformance with the Langmuir isotherm model and the maximum adsorption capacity reached 356.2 and 408.2 mg·g⁻¹ for MB and AR1, respectively. Furthermore, the thermodynamic parameters revealed that adsorption reaction using CSAA was spontaneous and exothermic.