Coated composite paper with nano-chitosan/cinnamon essential oil-nanoemulsion containing grafted CNC@ZnO nanohybrid; synthesis, characterization and inhibitory activity on Escherichia coli biofilm developed on grey zucchini

This investigation aims to highlight the applicability of a potent eco-friendly developed composite film to combat the Escherichia coli biofilm formed in a model food system. ZnO nanoparticles (NPs) synthesized using green methods were anchored on the surface of cellulose nanocrystals (CNCs). Subsequently, nano-chitosan (NCh) solutions were used to disperse the synthesized nanoparticles and cinnamon essential oil (CEO). These solutions, containing various concentrations of CNC@ZnO NPs and CEO, were sequentially coated onto cellulosic papers to inhibit Escherichia coli biofilms on grey zucchini slices. Six films were developed, and Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, biodegradation, and mechanical properties were assessed. The film containing 5 % nano-emulsified CEO + 3 % dispersed CNC@ZnO nano-hybrid in an NCh solution was selected for further testing since it exhibited the largest zone of inhibition (34.32 mm) against E. coli and the highest anti-biofilm activity on biofilms developed on glass surfaces. The efficacy of the film against biofilms on zucchini surfaces was temperature-dependent. During 60 h, the selected film resulted in log reductions of approximately 4.5 logs, 2.85 logs, and 1.57 logs at 10 °C, 25 °C, and 37 °C, respectively. Applying the selected film onto zucchini surfaces containing biofilm structures leads to the disappearance of the distinctive three-dimensional biofilm framework. This innovative anti-biofilm film offers considerable potential in combatting biofilm issues on food surfaces. The film also preserved the sensory quality of zucchini evaluated for up to 60 days.

Mesoporous epoxidized soybean oil-supported copper-based magnetic nanocatalyst and amberlite-supported azide as a green and efficient catalytic system for 1,2,3-triazole synthesis

A new green mesoporous magnetically heterogeneous catalyst was prepared by the copper immobilization onto magnetic epoxidized soybean oil as a nano bio-support and was utilized for the synthesis of 1,4-disubstituted-1,2,3-triazole derivatives in the presence of amberlite supported azide. A great range of triazole derivatives were synthesized from benzyl halides or epoxides halides in high yields at the room temperature. The catalyst was characterized by various techniques such as FT-IR, XRD, VSM, FE-SEM, EDX, TEM, BET, TGA, and ICP analysis. This catalytic system can be reused for five times without any significant decrease in the catalytic activity. Fe3O4@SiO-ESBO/CuO nanocatalyst and amberlite supported azide as a green catalytic system has been used for the regioselective synthesis of triazole derivatives in water. A large range of triazole derivatives were synthesized from benzyl halides or epoxides in high yields.

Efficient one-pot synthesis of pyrano[2,3-d]pyrimidinone derivatives catalyzed by a novel and recyclable CuO/NiO nanocatalyst

Background:

In this study, the synthesis and characterization of novel kind of NiO-supported CuO nanoparticles (CuO/NiO nanocatalyst), as an efficient and recyclable catalyst was investigated.

Methods:

Nanocatalyst was characterized by XRD, BET, FESEM, EDS, HRTEM, TGA and DSC analysis. It was used in the three-component synthesis reaction between barbituric acid, malononitrile and various aromatic aldehydes for the synthesis of pyrano[2,3-d]pyrimidinone derivatives.

Results:

The advantages of using CuO/NiO nanocatalyst in this reaction are high yields of products, decrease in the reaction times and easy separation of catalyst from the reaction mixture, and the reaction was performed in one-pot.

Conclusion:

The CuO/NiO nanocatalyst can be recycled for five consecutive cycles without a significant degradation in its catalytic activity.

Chemoselective Reduction of Nitroarenes with Hydrazine over a Highly Active Alumina-Supported Cobalt Nanocatalyst

A green and efficient procedure is reported for the chemoselective reduction of nitroarenes catalyzed by a highly active alumina-supported cobalt nanocatalyst in the presence of hydrazine hydrate. The nanocatalyst can be applied under mild reflux conditions for the synthesis of arlyamines in high yields. Moreover, the catalyst can be easily recovered by simple filtration and reused several times without obvious loss in its catalytic activity.

The effect of tamoxifen on the electrochemical behavior of Bi+3/Bi on the glassy carbon electrode and its determination via differential pulse anodic stripping voltammetry

The electrochemical behavior of Bi+3 ions on the surface of a glassy carbon electrode, in acidic media and in the presence of tamoxifen, was investigated. Cyclic voltammetry, chronoamperometry, differential pulse voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy were used to find the probable mechanism contributing to the reduction of the peak height of bismuth oxidation with an increase in the concentration of tamoxifen. The obtained results show a slight interaction between the bismuth species and tamoxifen which co-deposit on the surface of glassy carbon electrode. Therefore, the reduction in the peak height of bismuth oxidation as a function of tamoxifen concentration was used to develop a new differential pulse anodic striping voltammetry method for determination of trace amount of tamoxifen. The effects of experimental parameters on the in situ DPASV of Bi+3 ions in the presence of tamoxifen shown the optimal conditions as: 2 mol L-1 H2SO4 (1% v v-1 MeOH), a deposition potential of -0.5 V, a deposition time of 60 s, and a glassy carbon electrode rotation rate of 300 rpm. The calibration curve was plotted in the range of 0.5 to 6 µg mL-1 and the limits of detection and quantitation were calculated to be 3.1 × 10-5 µg mL-1 and 1.0 × 10-4 µg mL-1, respectively. The mean, RSD, and relative bias for 0.5 µg mL-1 (n=5) were found to be 0.49 µg mL-1, 0.3%, and 2%, respectively. Finally, the proposed method was successfully used for the determination of tamoxifen in serum and pharmaceutical samples.

Regioselective Synthesis of 1,2,3-Triazoles Catalyzed Over ZnO Supported Copper Oxide Nanocatalyst as a New and Efficient Recyclable Catalyst in Water

The CuO/ZnO nanocatalysts are reported as efficient and recyclable catalysts for the regioselective synthesis of 1,2,3-triazoles from benzyl halides and terminal alkynes in water. The catalysts are synthesized by a co-precipitation method and characterized by BET surface area, XRD, SEM, TEM and EDS analysis. The effect of CuO loading, catalyst amount and solvent was investigated. The catalyst can be recovered by a simple filtration and applied in consecutive runs with no loss of activity.

Efficient synthesis of benzopyrans and dihydropyranochromenes catalyzed by poly(4-vinylpyridine) as a green and commercially available basic catalyst

Poly(4-vinylpyridine) is used as a green, commercially available and recyclable basic catalyst for the multicomponent synthesis of benzopyrans and dihydropyranochromenes by one-pot condensation of aromatic aldehydes, 3-methyl-1-phenyl-2-pyrazolin-5-one, and malononitrile or 4-hydroxycoumarin in ethanol at reflux temperature. This procedure provides several advantages such as mild reaction conditions, short reaction times, simple work-up and high yields.

Amination of aryl halides with aqueous ammonia catalyzed by green recyclable poly(4-vinylpyridine)-supported copper iodide nanoparticles catalyst

In this research efficient procedure for the amination of aryl halides with aqueous ammonia in the presence of poly(4-vinylpyridine)-supported copper iodide nanoparticles catalyst is reported. A wide range of aryl halides including aryl iodides and aryl bromides are converted into the corresponding aniline derivatives. The experimental procedure with poly(4-vinylpyridine)-supported copper iodide nanoparticles catalyst is quite straightforward and it is recycled up to 3 consecutive runs by simple filtration.

A Green Recyclable Poly(4-Vinylpyridine)-Supported Copper Iodide Nanoparticle Catalyst for the Chemoselective Synthesis of Pentaerythritol Diacetals from Aromatic Aldehydes

Poly(4-vinylpyridine)-supported copper(I) iodide nanoparticles have been used as an efficient, green recyclable catalyst for the chemoselective synthesis of pentaerythritol diacetals from aromatic aldehydes and pentaerythritol under solvent-free conditions. This catalyst was reused six times without any loss of its activity.