Antiultraviolet, Antioxidant, and Antimicrobial Properties and Anticancer Potential of Novel Environmentally Friendly Amide-Modified Gallic Acid Derivatives.

Polyphenols and amides isolated from natural products have various biological functions, such as antioxidant, antimicrobial, anticancer, and antiviral activities, and they are widely used in the fields of food and medicine. In this work, four novel and environmentally friendly amide-modified gallic acid derivatives (AMGADs), which were prepared by using different amides to modify gallic acid (GA) from Polygonaceae plants, displayed good antiultraviolet (anti-UV), antioxidant, antimicrobial, and anticancer effects. Significantly, the anti-UV capability of compounds n1 and n2 was notably superior to that of the UV absorber GA. Moreover, compound n2 possessed better 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging ability and ferric reducing antioxidant power than vitamin C. The antibacterial activities of all AMGADs, with inhibition rates of more than 96.00 and 79.00% for Escherichia coli and Staphylococcus aureus, respectively, were better than those of GA. Compound n1 had broad-spectrum anticancer activity, and its inhibitory effect on HepG2 cells exceeded that of 5-fluorouracil. The good and rich bioactivities of these AMGADs revealed that combining GA with amides is conducive to improving the activity of GA, and this study laid a good foundation for their scientific application in the fields of food and medicine.

Effects of manganese content and calcination temperature on Mn/Zr-PILM catalyst for low-temperature selective catalytic reduction of NOx by NH3 in metallurgical sintering flue gas.

The effects of manganese content, carrier calcination temperature, and catalyst calcination temperature of manganese-based zirconium pillared intercalated montmorillonite (Mn/Zr-PILM) catalysts were investigated for low-temperature selective catalytic reduction of NOx by NH3 (NH3-SCR) in the metallurgical sintering flue gas. The physicochemical properties of these catalysts can be characterized by X-ray diffraction (XRD), N2 adsorption-desorption isotherm, and temperature-programmed desorption of ammonia (NH3-TPD). The 10Mn/Zr400-PILM(300) catalyst had the highest NOx conversion under excess oxygen conditions (15 vol% oxygen) and reached 91.8% NOx conversion at 200 °C. It was found that when the loading of manganese was 10 wt.%, the catalyst had the highest catalytic activity and the manganese-active component was highly dispersed on the Zr-PILM surface. The optimal calcination temperature of the Zr-PILM was 400 °C because the catalyst pore size was concentrated at 1.92 nm and the catalyst had the most acidic sites. And the optimum calcination temperature of the catalyst was 300 °C. This was because excessive calcination temperature promoted the manganese oxide polymerization and reduced the catalytic activity of the catalyst.

Fabrication of manganese-based Zr-Fe polymeric pillared interlayered montmorillonite for low-temperature selective catalytic reduction of NOx by NH3 in the metallurgical sintering flue gas.

A series of Zr-Fe (Zr/Fe = 4:0, 3:1, 2:2, 1:3, 0:4) polymeric pillared interlayered montmorillonite loading 10 wt.% MnOx (Mn/Zr-Fe-PILM) were investigated for the selective catalytic reduction of NOx by NH3 (NH3-SCR) in metallurgical sintering flue gas. The X-ray diffraction (XRD), N2 adsorption-desorption isotherm, scanning electron microscope (SEM), and ammonia temperature-programmed desorption (NH3-TPD) were used to analyze the physicochemical property. The Fe polymerized with Zr exchanged to montmorillonite can improve the Mn/Zr-Fe-PILM low-temperature NOx conversion and N2 selectivity. The Mn/Zr-Fe-PILM (1:3) shows the highest NOx conversion between 140 and 180 °C. The XRD results suggest that the growth of crystalline ZrO2 phase is intensely restrained for the Fe2O3 migration into the ZrO2 lattice. The ZrO2 and MnOx have an excellent dispersion in montmorillonite. The N2 adsorption result illustrates that the increase of Fe molar content in the Zr-Fe-PILM support increases the catalyst-specific surface area. The NH3-TPD results elucidate that the Mn/Zr-Fe-PILM (1:3) has the most total acid sites. Therefore, the low-temperature catalytic activity of the Mn/Zr-Fe-PILM (1:3) has been assigned to the large specific surface area, abundant acid sites, and the dispersion of metallic oxides.

Sm-doped manganese-based Zr-Fe polymeric pillared interlayered montmorillonite for low temperature selective catalytic reduction of NO x by NH3 in metallurgical sintering flue gas.

In this work, Sm-doped manganese supported Zr-Fe polymeric pillared interlayered montmorillonites (Mn/ZrFe-PILMs) were prepared for the low-temperature selective catalytic reduction (SCR) of NO x with NH3 in metallurgical sintering flue gas. These pillared interlayered montmorillonite catalysts were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy, nitrogen adsorption-desorption isotherm, ammonia temperature-programmed desorption, and hydrogen temperature-programmed reduction to study the influence of Sm doping on the SCR performance. The ZrFe-PILMs with a Mn/Sm molar ratio of 18 : 2 showed the excellent SCR activity among these catalysts, where a 95.5% NO x conversion ratio at 200 °C at a space velocity of 20 000 h-1 was obtained. Samarium oxide and manganese oxides were highly dispersed on the ZrFe-PILMs with different Mn/Sm molar ratios by the XRD results and SEM-EDS results. Meanwhile, the Mn-Sm/ZrFe-PILM (18 : 2) had the lowest temperature hydrogen reduction peak by H2-TPR results, which indicated that it had the lowest active bond energy on its surface. And the NH3-TPD results expressed that the Mn-Sm/ZrFe-PILM (18 : 2) had the most acidic sites, especially the weakly acidic sites. Therefore, it was found that the introduction of a small amount of Sm (Mn : Sm = 18 : 2) to Mn/ZrFe-PILM can significantly improve catalytic activity by the increased active oxygen component and the surface acidity.

Identification and molecular characterization of twin-arginine translocation system (Tat) in Xanthomonas oryzae pv. oryzae strain PXO99.

Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, one of the most widespread and destructive bacterial diseases in rice. This study identified and characterized the contribution of the twin-arginine translocation (Tat) pathway to motility, chemotaxis, extracellular polysaccharide (EPS) production and virulence in X. oryzae pv. oryzae strain PXO99. The tatC disruption mutant (strain TCM) of strain PXO99 were generated, and confirmed both by PCR and Southern blotting. Strain PXO99 cells were highly motile in NYGB 0.3% soft agar plate. In contrast, the tatC mutation impaired motility. Furthermore, strain TCM cells lacked detectable flagella and exhibited almost no chemotaxis toward glucose under aerobic conditions, indicating that the Tat secretion pathway contributed to flagellar biogenesis and chemotactic responses. It was also observed that strain TCM exhibited a reductive production of extracellular polysaccharide (EPS) and a significant reduction of virulence on rice plants when compared with the wild type PXO99. However, the tatC mutation in strain PXO99 did not affect growth rate and the ability to induce hypersensitive response (HR) in nonhost tobacco (Nicotiana tabacum L. cv. Samsun). Our findings indicated that the Tat system of X. oryzae pv. oryzae played an important role in the pathogen's virulence.