- Assembly of nitroreductase and layered double hydroxides toward functional biohybrid materials
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The development of new multifunctional materials integrating catalytically active and selective biomolecules, such as enzymes, as well as easily removable and robust inorganic supports that allow their use and reuse, is a subject of ongoing attention. In
- Bruna, Felipe,Mousty, Christine,Besse-Hoggan, Pascale,Batisson, Isabelle,Prevot, Vanessa
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- Selenium-catalyzed intramolecular atom- And redox-economical transformation ofo-nitrotoluenes into anthranilic acids
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Anthranilic acids (AAs) are significant basic chemicals used in pharmaceuticals, agrochemicals, dyes, fragrances,etc. Superfluous steps are always involved in obtaining AAs. Herein, we demonstrate a straightforward strategy to transform abundanto-nitrotoluenes into biologically and pharmaceutically significant AAs without any extra reductants, oxidants and protecting groups. Various sensitive groups, such as halogens, sulfide, aldehyde, pyridines, quinolines,etc., can be tolerated in this transformation. A hundred-gram-scale operation is realized efficiently with almost quantitative selenium recycling. Further mechanistic studies and DFT calculations disclosed the proposed atom-exchange processes and the key roles of the selenium species.
- Jiang, Xuefeng,Li, Yiming,Lin, Zhenyang,Wang, Yuhong,Yang, Tilong
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supporting information
p. 2986 - 2991
(2021/05/05)
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- Anthranilic acid and derivatives thereof as well as synthesis method and application thereof
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In the reaction solvent, o-methyl (hetero) aryl nitro compound is taken as a reaction raw material and is used for water. The anthranilic acid and its derivatives are synthesized by the action of a catalyst, a base and an additive. The synthetic method has the advantages of cheap and easily available raw materials, simple reaction operation, high yield and excellent functional group tolerance, and provides a simple and efficient method for synthesizing o-aminobenzoic acid which is widely used in the aspects of dyes, medicines, pesticides, spices and the like. The invention further discloses the anthranilic acid and derivatives and application thereof, and has a wide application prospect.
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Paragraph 0071-0073
(2021/09/15)
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- The photo-degradation of mesotrione, a triketone herbicide, in the presence of CuII ions
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The study focuses first on the complexation of CuII ions with mesotrione. Experimental absorption spectra combined with quantum chemical calculations highlight that CuII ions bind to the molecule in bidentate mode between O1 and O7 atoms. The calculated electronic transitions of the complex show that three of them are mostly ligand-to-ligand electron transfer while the lowest-energy one involves a ligand-to-metal charge transfer (LMCT). The second aim of this work is to explore the effect of CuII complexation on the photo-degradation of mesotrione. The kinetics and mechanisms of the reactions are proposed on the basis of the experimental results. The effect of different parameters such as the irradiation wavelength, the oxygen concentration and the pH of the mixture and also the production of reactive species such as hydroxyl radicals is investigated. The photochemical degradation of mesotrione in water arises from the triplet excited state of the molecule and results in a photo-hydrolysis process. For the complex, by exciting mainly in its LMCT absorption band, an electron transfer between copper and mesotrione probably occurs and the mechanism of mesotrione-CuII photo-degradation differs: in addition to the photo-hydrolysis route, a photo-cyclisation process takes place and the oxidation of the ligand is accompanied by the reduction of CuII ions.
- Le Person, Anna?g,Siampiringue, Marie,Sarakha, Mohamed,Moncomble, Aurélien,Cornard, Jean-Paul
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- Kinetics and the mechanism of the photocatalytic degradation of mesotrione in aqueous suspension and toxicity of its degradation mixtures
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The photocatalytic degradation of the herbicide mesotrione (0.05 mM) in aqueous suspensions of TiO2 Degussa P25 and ZnO was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.00 mg mL-1 under UV light at the pH 4.0 (TiO2 Degussa P25) and pH 9.2 (ZnO). In the first stage of the reaction, the photocatalytic degradation of mesotrione followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds mainly via ?OH radicals, and partly also via holes. The results showed that the disappearance of mesotrione led to the formation of a number of organic intermediates and ionic byproducts, whereas its complete mineralization occurred after about 4 h. Tentative photodegradation pathways were proposed and discussed as a function of the type of photocatalyst. A comparison of the evolution of toxicity that was evaluated in vitro in the rat hepatoma (H-4-II-E) and human fetal lung (MRC-5) cell lines with the degradation kinetics indicates that the cell growth of both cell lines was only mildly affected by the mixture of mesotrione and its photocatalytic degradation intermediates obtained using TiO2 Degussa P25, and moderately affected by the mixtures obtained using ZnO, whereby at 120 min toxicity decreased.
- ?oji?, Daniela V.,Or?i?, Dejan Z.,?etojevi?-Simin, Dragana D.,Despotovi?, Vesna N.,Abramovi?, Biljana F.
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