Chemical Papers最新文献

Microfluidic (MF) technology offers significant advantages for nanomaterial synthesis due to precise process control and automation. This study compares the physicochemical properties and antimicrobial activities of copper (I) oxide nanoparticles (Cu₂O NPs) synthesized using conventional batch and MF methods, with glucose as a reducing agent for CuSO₄ and starch as a capping agent. The reaction was carried out with NaOH concentrations ranging from 0.06 to 0.5 M. In the range of 0.08–0.15 M NaOH, X-ray diffraction analysis and scanning electron microscope images revealed smaller particles (< 100 nm), with the MF method producing more uniform particles. Dynamic light scattering results showed larger particles formed outside this NaOH concentration range. The conventional batch method produced more stable Cu₂O NPs, while MF NPs tended to agglomerate over time. Zeta potentials of all Cu₂O NPs were higher than −20 mV, indicating stabilization by polymeric starch adsorption. Antimicrobial activity was evaluated by incubating Escherichia coli and Colletotrichum gloeosporioides with Cu₂O NPs. Batch Cu₂O NPs exhibited higher antimicrobial activity than MF Cu₂O NPs. The highest inactivation was achieved with 0.15 M NaOH batch Cu₂O NPs, showing a 5.55 log reduction of E. coli and 96% growth inactivation of C. gloeosporioides.

This study primarily focuses on boron carbon nitride (BCN) synthesis using the O’Connor method, a proven technique for solid-state boron nitride production. The process involved heating a mixture of boron oxide, urea, and activated charcoal in an ammonia gas atmosphere. Varied ratios of activated charcoal, ranging from 10 to 30% (w/w), were introduced into the boron oxide and urea mixture (1:2 w/w). The experiments aimed to investigate the influence of activated charcoal on BCN production, which was conducted in a controlled atmosphere tube furnace at 1450 °C for 3 h. Characterization of the resulting products employed Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy (EDS). FTIR analysis highlighted shoulder peaks at 1123 and 2349 cm⁻¹, indicative of single-bonded BC and triple-bonded CN. XRD patterns exhibited broadening with increased activated charcoal, suggesting the BCN nature of the structure. Furthermore, Rietveld refinement further supported the BCN system and molecular composition analysis via EDS measurements revealed the BCN triple system. Analysis of the data indicated a positive correlation between the molar ratio of charcoal and BCN production. Higher amounts of charcoal facilitated BCN formation, promoting carbon insertion into the BN layered structure.

In this study, we report the development of a novel bio-carbon-derived porous reduced graphene oxide (BC-rGO) photo- and electrochemical sensor for the ultra-sensitive detection of testosterone hormone. Bio-carbon-derived rGO, synthesized from agricultural waste, offers a sustainable, cost-effective, and environmentally friendly alternative to traditional chemically derived rGO. The effect of different thermal reduction temperatures (100 °C, 200 °C, 300 °C, and 400 °C) on the properties of the synthesized rGO was investigated. The crystallite sizes of BC-rGO1, BC-rGO2, BC-rGO3, and BC-rGO4 were determined to be 65 nm, 54 nm, 48 nm, and 41 nm, respectively, using the X-Ray diffraction (XRD) data. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed the morphology of the prepared rGO nanosheets, showcasing a two-dimensional nanostructure with transparent lamellar structures and abundant folds dispersed throughout the basal plane. To construct the biosensor for testosterone detection, the BC-rGO was initially fabricated by chemical cross-linking and used to modify the Nafion-pretreated glassy carbon electrode (GCE). BC-rGO prepared at 400 °C demonstrated superior sensitivity and selectivity toward testosterone detection, owing to the enhanced surface chemistry facilitated by the bio-carbon-derived material. The sensor's performance was evaluated through both photo- and electrochemical methods, revealing ultra-sensitive detection capabilities for testosterone hormone. Among the fabricated electrodes, Nafion/BC-rGO4 on GCE showed the highest electrochemical response, indicating superior activity in testosterone oxidation. The synergistic effects of BC-derived 2D rGO and testosterone increase the photocatalytic activity of Nafion/BC-rGO@GCE, making it more effective at detecting testosterone than Nafion@GCE. The results demonstrated that the thermal reduction temperature significantly influenced the electrochemical performance of the rGO, with the optimal performance observed at 400 °C. The use of BC-derived rGO not only addresses environmental sustainability but also provides a highly efficient platform for the sensitive and selective detection of testosterone, making it a promising candidate for medical applications.

This study aimed to prepare and evaluate coconut (TWO-CO) and banana flavored (TWO-BN) oleogels from cold-pressed tiger nut oil (TO) and whale spermaceti wax (WW) against a control (TWO) sample. The samples had 8.41–8.45 min of gelation times and over 99.00% of oil binding capacities. Their color values (L, a*, b*), free fatty acidities (2.40–2.66% linoleate), and peroxide values (2.12 ± 0.48–3.43 ± 0.16 meqO₂/kg) were acceptable. X-ray diffraction data proved the presence of β' type polymorphs in all samples. The mean peak melting temperatures were 35.82, 39.02, and 36.39 °C for the TWO, TWO-BN, and TWO-CO, respectively. The rheological frequency sweep test showed storage modulus (G´) values of 10–11 kPa for TWO, 13–15 kPa for TWO-BN, and 105–110 kPa for TWO-CO. All samples had structural recovery ability after exposing and ceasing to high shear. Further, all samples have reached the cross-over point (G´ = G´´) at around 38–40 °C. The samples had 29, 16, and 27 volatile aromatic compounds for the TWO, TWO-BN, and TWO-CO, respectively. In conclusion, this study proved that successful oleogels could be prepared with TO and WW, and these underutilized resources could be alternative players in oleogel industry.

In this study, Fe₃O₄-coated multi-walled carbon nanotubes (MWCNT-Fe₃O₄) or nickel oxide-coated multi-walled carbon nanotubes (MWCNT-NiO) were activated with 3-Glycidyloxypropyl)trimethoxysilane (3-GPTMS) to create oxirane groups. Pullulanase from Bacillus licheniformis was covalently immobilized on these magnetic MWCNTs to obtain magnetically separable immobilized pullulanase preparations (MWCNT-Fe₃O₄@Pul or MWCNT-NiO@Pul) for producing maltooligosaccharides (MOSs) from pullulan. The highest recovered activity values were 78% and 85% respectively, for MWCNT-Fe₃O₄@Pul and MWCNT-NiO@Pul after 24 h of immobilization at pH 7.0. The optimal pH and temperature were found to be 5.5 and 45 °C for free pullulanase, whereas the corresponding values were 5.5 and 50 °C for both immobilized pullulanase preparations. The thermal stabilities of MWCNT-Fe₃O₄@Pul and MWCNT-NiO@Pul increased by 6.2- and 8.2-fold, respectively, at 50 °C. The catalytic efficiencies of MWCNT-Fe₃O₄@Pul and MWCNT-NiO@Pul were calculated to be 0.8- and 1.1-fold that of free pullulanase, respectively. After 24 h of hydrolysis, MOS yields were determined to be 470 and 490 mg MOS/g pullulan for MWCNT-Fe₃O₄@Pul and MWCNT-NiO@Pul, respectively. The remaining activities were 86% and 85% for MWCNT-Fe₃O₄@Pul and MWCNT-NiO@Pul after 10 reuses, respectively.

Nocardia farcinica is a Gram-positive bacteria that causes opportunistic infections. Chronic lung illness, diabetes mellitus, renal disease, immunosuppressive treatment, hematological neoplasm, and transplant recipients are predisposing factors. Brain abscesses, skin or soft tissue infections, and pulmonary infections are examples of clinical manifestations of Nocardia farcinica infection. Nocardia farcinica is the rare cause of brain abscesses, making up 2% of all intracranial abscesses. In the present study, the subtractive proteomics approach was used for potential drug targets identification in the Nocardia farcinica strain IFM 10152 to evaluate the pathogen-specific and essential proteins by using various bioinformatics tools. A total eighteen specific pathways were found in Nocardia farcinica strain IFM 10152 and eight proteins were involved in these specific pathways. A total of three proteins were found as Druggable. Furthermore, 3D structure prediction for one of the drug targets putative penicillin binding protein was carried out by Alpha-Fold2 one of the deep learning approaches. Virtual screening was performed for the identified drug target. To evaluate the stability of the new hits against the drug target molecular dynamics simulation was carried out. This study provides valuable information about the discovery of new drug targets that may help to eradicate Nocardia farcinica associated infections. To the best of our knowledge, this is the first attempt to apply the subtractive proteomics approach on the complete proteomic data of Nocardia farcinica strain IFM 10152, thus providing an opportunity to predict specific therapeutic targets and their inhibitors against Nocardia farcinica.

By means of density functional theory and first-principle molecular dynamics (FPMD) simulations, the corrosion inhibition potential of allopurinol (Allo), oxypurinol (Oxy), and thiopurinol (Thio) expired drugs toward the aluminium (Al) (111) surface was thoroughly examined. ESP maps and FMOs analysis indicated the electron-donating nature of the studied drugs. From global reactivity descriptors, the potential of the Allo, Oxy, and Thio drugs in gas and aqueous phases as corrosion inhibitors was confirmed. Thio drug showed lower IP and higher EA values than the other investigated drugs, illustrating its higher reactivity. Further, the lowest value of ƞ and the highest value of σ were found for the Thio drug, indicating its high potential as a corrosion inhibitor. Employing FPMD simulations, the most stable configurations of the drug∙∙∙Al (111) complexes were determined, and the corresponding interaction and binding energies were estimated. According to the energetic affirmations, the Thio drug demonstrated the largest affinity to inhibit the Al (111) surface with an interaction energy (E_int) value of − 25.12 kcal/mol. The findings of the charge transfer (Q_t) were in line with the E_int, in which the Q_t of the drug∙∙∙Al (111) complexes decreased in the order Thio∙∙∙ > Allo∙∙∙ > Oxy∙∙∙Al (111) with values of − 0.5119, − 0.2737, and − 0.2471 e, respectively. The obtained results would provide fundamental insights into the promising application of Allo, Oxy, and Thio expired drugs as corrosion inhibitors, especially for aluminium surface.

Graphical abstract

Eugenol is a lignin-derived aromatic model compound extracted from the lignin and has been used for various reactions. The eugenol esterification to eugenol benzoate with benzoic acid was studied using different deep eutectic solvents (DESs) as catalysts. DESs are a type of ionic liquid that is formed by combining a hydrogen bond donor with a hydrogen bond acceptor. In the current paper, carboxylic acids such as oxalic acid, acetic acid, p-toulenesulfonic acid (p-TSA) and tartaric acid were used as hydrogen bond donors to form choline-based DESs which were used as catalysts in esterification reactions. The catalysts were screened based on the conversion and p-TSA based DES was found to be best and used for further experiments. Effects of parameters (eugenol to benzoic acid ratio, reaction time, temperature, and catalyst loading) on the yield of eugenol benzoate were studied. The highest eugenol conversion was obtained as 90.42% (383 K, 0.02 g/cm³ catalyst, molar ratio of eugenol to benzoic acid = 1:5, 600 rpm, 3 h).

The desire for products that are healthier, safer, and better for the environment is on the rise in society. Chalcones are aromatic ketones with anxiolytic and antimicrobial properties. The limited solubility, bioavailability, and long-term stability of chalcones hinder their application. Nanoemulsions can be used as a drug transport system to address this problem. The primary objective of our research was to design nanoemulsions through ANOVA (NE) with nanoscale droplets that would maintain exceptional stability, optimizing the anxiolytic capacity of chalcones. Sodium alginate and chitosan were assessed as the continuous phase material, while commercial soybean oil and mineral oil were used as adjuvants, besides surfactant, for the oil phase composition of the droplets. Results showed that the addition of soybean oil improved significantly the stability of the formulations, as did the use of the alginate matrix. The optimal NE showed a nanometer-sized droplet (126 nm) and negative ζ-potential (− 42 mV), showing good stability under different conditions—it synergistically enhances the anxiolytic potential. The mode of operation is associated with the receptors of the serotonergic system (5-HT). Toxicity, locomotion and anxiety tests performed using the zebrafish animal model showed a promising dose (0.0325 mg/mL) for the development of compounds with anxiolytic properties.

Graphical abstract

This work shows the utilization of glycyrrhizic acid (GLA) as a corrosion inhibitor for steel within acidic environments. Employing a multifaceted approach, the investigation integrates spectral analysis, thermal testing, electrochemical assessments, surface characterization techniques, and computational modeling to elucidate GLA’s mechanisms of corrosion protection. A pivotal finding of this research underscores GLA’s capacity to engage with metal surfaces through both physisorption and chemisorption mechanisms, facilitated by its inherent functional groups. Moreover, thermal analysis reveals GLA’s robust stability up to temperatures of 170°C, rendering it well suited for applications within moderate-temperature environments. Electrochemical analyses unveil a notable augmentation in charge transfer resistance, escalating from 5.18 to 90.64Ω/cm², alongside a concomitant reduction in corrosion current density from 15.64 to 0.83μA/cm², particularly evident at 200mg/L. Surface examinations corroborate the ameliorated state of surfaces treated with GLA, with discernible compositional alterations indicative of efficacious corrosion inhibition. Adsorption studies align with the Langmuir model, suggesting monomolecular adsorption behavior. Thermodynamic scrutiny reveals a spontaneous and endothermic process, with heightened efficacy observed at elevated temperatures. Lastly, the computational model unveils robust interactions between GLA and the metal surface, characterized by interaction energies reaching as low as −2033.91kJ/mol, thus underscoring the stability inherent in the protective layer formed by GLA.