Search

In this study, silica-gel (SG)-supported deep eutectic solvent (DES) with a different loading dosage as the novel nanocomposite materials has been synthesized by sol–gel method. And the supported nanocomposite materials were used as the catalyst for the synthesis of 1,10-phenanthroline from the 8-aminoquinoline and acrolein. The properties and structure of catalysts were characterized by Fourier transform infrared, N2 adsorption–desorption, scanning electron microscopy, thermogravimetric analysis and elemental analysis techniques. It was found that the 12%DES/SG catalyst with the best catalytic activity possessed the suitable specific surface area 132 m2/g and 12% loading amount of DES, which combines the excellent properties of mesoporous materials and DES. The result of thermogravimetric analysis was exhibited that the nanocomposite materials could not be decomposed below 240 °C, which can be used as a stable catalytic material under reaction conditions. Furthermore, the effect of reaction parameters such as reaction temperature and catalyst amount, molar ratio of 8-aminoquinoline and acrolein and reaction time was also studied. Under the optimal process parameters, within the optimum parameters: 130 °C, acrolein: 8-AQ = 2:1, catalyst amount 20 wt%, and time 4 h, the conversion of 8-aminoquinoline and selectivity of 1,10-phenanthroline were 83.8% and 84.3%, respectively. Otherwise, the catalyst can be separated from the reaction system and reused. Therefore, the silica-gel-supported deep eutectic solvent nanocomposite materials can be considered as a potential catalytic material for the synthesis of 1,10-phenanthroline and other nitrogen-containing heterocyclic organic chemical intermediates. Replacing traditional sulfuric acid and hydrochloric acid with silica-gel-supported deep eutectic solvents as new nanocomposite catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline. [ABSTRACT FROM AUTHOR]

The melamine formaldehyde (MF) resin fiber has been used in various fields due to its excellent heat resistance, but it's mechanical properties still need to be improved. Using melamine and paraformaldehyde as raw materials, 1,4‐cyclohexanedimethanol (CHDM) as the comonomer, a series of modified fibers with different copolymerization ratios are prepared by dry spinning. The research results show that melamine, paraformaldehyde, and CHDM can co‐polymerize by one‐step. The introduction of CHDM can effectively improve the heat resistance and mechanical properties of the fiber. When the addition amount of CHDM is 6%, the copolymeric fibers are cylindrical with a smooth surface and bubble‐free inside, the breaking strength is 1.80 cN/dtex and the elongation at break is 13.75%. Compared with the unmodified fiber, the breaking strength is decreased by approximately 5%, and the breaking elongation is increased by nearly 90%. The thermal properties of the copolymeric fibers are not decreased, and the mass residual rate at 400°C is increased from 36.12% to 46.11%. This study provides a method of copolymeric‐modified without fiber‐forming aid to prepare high‐performance MF fibers. [ABSTRACT FROM AUTHOR]

In this study, three different choline chloride-based deep eutectic solvents were synthesized. And it is the first time to synthesize 1,10-phenanthroline through an improved Skraup reaction using deep eutectic solvent as the new catalyst from acrolein and 8-aminoquinoline. The deep eutectic solvents were characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H NMR), pH/mV meter, and thermogravimetric analysis (TGA). The research results show that the deep eutectic solvent formed by sulfanilic acid and choline chloride has the strongest acidity and highest catalytic active among the three deep eutectic solvents. Besides, the impacts of reaction parameters and molar ratio of raw materials on the reaction were also investigated. Under the optimized reaction conditions, the maximum selectivity and yield of 1,10-phenanthroline were achieved as 84.6 and 75.6%, respectively. The synthesis method, meanwhile, also has simple preparation process and low cheaper catalyst raw. Replacing traditional sulfuric acid and hydrochloric acid with deep eutectic solvents (DESs) as new catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline by a new improved Skraup reaction. [ABSTRACT FROM AUTHOR]

Context: Marek's disease (MD) seriously threatens the world poultry industry and has resulted in great economic losses. Chinese medicinal herbs are a rich source for lead compounds and drug candidates for antiviral treatments. Objective: To investigate the anti-MDV activity and mechanism of 20 compounds extracted from Chinese medicinal herbs. Materials and methods: Antiviral assay, time of addition experiments, and virucidal assay were performed on chicken embryo fibroblast cells. The 50% cytotoxic concentration and 50% effective concentration were determined and, accordingly, selectivity index and inhibition ratio were calculated. Results: Antiviral assay showed dipotassium glycyrrhizinate (DG) and sodium tanshinone IIA sulfonate (STS) exhibited significantly inhibitory activity against MDV in a dose-dependent manner. EC50 of DG and STS were 893.5 ± 36.99 µg/mL and 54.82 ± 2.99 µg/mL, and selective index (SI) were >3.36 and >9.12, respectively. Time of addition experiment and virucidal assay demonstrated DG inhibited viral replication in the full replication cycle and inactivated MDV particles in non-time-dependent manner, but STS interfered with the early stage of MDV replication and inactivated MDV particles in a time-dependent manner. Moreover, both DG and STS promoted apoptosis of cells infected by MDV. Discussion and conclusion: DG and STS have great potential for developing new anti-MDV drugs for clinic application. [ABSTRACT FROM AUTHOR]