65 research outputs found
Conception, synthÚse et évaluation pharmacologique d'inhibiteurs mixtes de la farnésyltransférase et de la polymérisation de la tubuline
LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF
The phytoextraction power of Cichorium intybus L. on metal-contaminated soil: Focus on time- and cultivar-depending accumulation and distribution of cadmium, lead and zinc
International audienc
Toward a New Way for the Valorization of Miscanthus Biomass Produced on Metal-Contaminated Soils Part 2: Miscanthus-Based Biosourced Catalyst: Design, Preparation, and Catalytic Efficiency in the Synthesis of Moclobemide
International audienceThe conception of two biosourced catalysts (biocatalysts) using stems of miscanthus from the first part of this study are described herein. The temperature and the process used to extract metals from plant as mixture of Lewis acids were investigated in detail and proved to be essential in the design of the biosourced catalysts and their catalytic efficiency. One part of the crude mixture of Lewis acids extracted from the aerial parts of miscanthus plants was used without further treatment as a homogeneous biocatalyst (M1), and the other part was supported on montmorillonite K10 to provide a heterogeneous biocatalyst (MM1). M1 and MM1 were next tested in the synthesis of moclobemide (main ingredient of a drug used to treat depression) and led to excellent yield. Additional comparative experiments with different commercial metallic salts (NaCl, KCl, CaCl2, MgCl2, CuCl2, ZnCl2, FeCl2, FeCl3, MnCl2, and AlCl3) and their mixtures were carried out and underlined the importance of the multimetallic synergy on catalytic activity. Finally, a comparison of this new synthetic method assisted by the biosourced catalyst with the previously described procedures to access moclobemide was realized by calculating their green chemistry metrics. This study revealed that the use of the biosourced catalyst led to one of the greenest synthetic methods described today to produce moclobemide
Core-shell Particles: A Way to Greening Liquid Chromatography in Environmental Applications
ACLBackground: Since the 1990s, technical developments and theoretical studies of columns packed with core-shell and sub-core-shell particles demonstrated improved efficiency separation, time reduction, solvent use than fully porous columns. Thanks to this chromatographic system, environmental pollutants are being analysed under green conditions. Objective: This paper presents theoretical aspects and a review of the main features of core-shell technology focusing essentially on environmental applications. Method: The main advantages of core-shell columns may be summarized as follows: i) reduction of the eddy dispersion A term; ii) homogeneity of the particle size distribution reducing the velocity bias; (iii) superior mass transfer kinetics; iv) better performance of the separation (faster and greater). Results: Systematic comparisons with fully porous particles undeniably highlighted the benefits of core-shell technology in the separation of a great number of pollutants and âmicropollutantsâ of different molecular weights which surround us and have an impact on the ecosystem. Conclusion: Core-shell particles are emerging as green substrates for the analysis of chemical species problematic for environment. The environmental gain in terms of limitation of analysis time and solvent consumption has been demonstrated. The current manuscript proposes an update of the literature devoted to the use of core-shell particles in environmental applications. Future trends in the field and the expectations of the scientific community are also described since increasing attention is being paid to the detection of environmental pollutants
Ecocatalysis for the synthesis of high-added molecules for therapeutic purposes. Innovative techniques for chemistry and processes
INVInternational audienc
Switching the reactivity of cyanomethylpyridinium salts in the 1,3-cycloaddition conditions with alkyl propiolates to cyanoindolizines or cyanoazaindolizinyl-indolizines
International audienceA particular reactivity of 1-cyanomethylpyridinium salts was revealed in the [3 + 2] cycloaddition conditions with alkyl propiolates. Cycloadducts 3 were obtained in reactions carried out at room temperature while refluxing in CH3CN provided unexpected ethyl or methyl 3-(3-cyanoimidazo[1,2-a]pyridin-2-yl)indolizine-1-carboxylates 4. The structure of the new 2:1 azaindolizine-indolizine adducts was secured by X-ray analysis. Methodological efforts have enabled the adjustment of the reactivity towards the formation of 3-cyanoindolizines 3 or cyanoazaindolizine-indolizines 4. A mechanism for the formation of azaindolizine-indolizines was proposed. A portfolio of rare cyanoindolizines and cyanoazaindolizine-indolizines has been successfully obtained
Wheat and ryegrass biomass ashes as effective sorbents for metallic and organic pollutants from contaminated water in lab-engineered cartridge filtration system
ACLThree plant biomasses (miscanthus, ryegrass and wheat) have been considered for the preparation of five different sorbents evaluated for their potential to sorb cadmium and lead and four emergent organic compounds (diclofenac, sulfamethoxazole, 17α-ethynylestradiol and triclosan) from artificially contaminated water. Labcreated cartridges were filled with each sorbent and all experiments were systematically compared to activated charcoal NoritŸ. Results from activated charcoal, wheat straw and acidified wheat straw were supported by the Langmuir and Freundlich models. Wheat straw ashes were an excellent metal extractor that exceeded the potential of well-known activated charcoal. Acidified sorbents (wheat and ryegrass) were very effective in eliminating the selected emerging organic contaminants displaying equipotent or superior activity compared to activated charcoal. These results open the way for further in natura studies by proposing new biosource materials as new effective tools in the fight against water pollution
Performance comparison of chlorinated chiral stationary phases in supercritical fluid chromatography for separation of selected pyrrolidone derivatives
An original approach in green chemistry: From assisted-phytoremediation of contaminated soil to upcycling of plant biomass for biosourced catalyst production
ACTIInternational audienceA kitchen garden soil was sampled in a contaminated urban area located in the north of France. Samples were air-dried and crushed to pass through a 10-mm stainless steel sieve. Due to the high heterogeneity of garden soils in the studied area, much attention have been paid on the homogeneity of soil samples. After this step, the mass of sampled soils (48 kg) was divided to obtain four subsamples Each of them was divided in six replicates, unamended or amended using dicalcium phosphate (DCP) or monocalcium phosphate (MCP) or a mixture of these two compounds (MxP=75%DCP+25%MCP) The phosphorous amendments were added into the soil in small quantity (0.02 %) with the aim at reducing the environmental availability of carcinogenic metals and to increase the Zn availability (Figure 1) After the stabilisation period (2 months) in a greenhouse, 1 5 g of ryegrass seeds (Lolium perenne L.) were sown in the 24 containers. Eight weeks after sowing, ryegrass shoots were harvested, oven-dried at 40 °C and calcined at 500 °C in a muffle furnace (Nabertherm P330, Lilienthal, Germany)
A sustainable approach to manage metal-contaminated soils a preliminary greenhouse study for the possible production of metal-enriched ryegrass biomass for biosourced catalysts
International audienceTwo kitchen garden soils (A and B) sampled in contaminated areas were amended using phosphates in sustainable quantities in order to reduce the environmental availability of potentially toxic inorganic elements (PTEs) and to favour the availability of alkali, alkali earth and micronutrients. The environmental availability of PTEs was evaluated using a potential plant for revegetation of contaminated soils (ryegrass) and a mixture of low molecular weight organic acids. Despite the highest contamination level of B, the concentration of metals was highest in the ryegrass shoots grown on A for the two harvests. These results correlated well with those obtained using low molecular weight organic acids for Cd, Zn and Cu, whereas this mixture failed to represent the transfer of nutrients due to the presence of biological and physiological mechanisms. The statistical differences between the biomass of ryegrass obtained at the first and the second harvests were attributed to the decrease of available potassium, implicated in the growth and development of plants. Phosphates increased the ratios Zn/Cd, Zn/Pb and Zn/Cu up to 176 ± 48, 38 ± 6 and 80 ± 12, respectively, and made possible the reduction of the concentration of Cd and Pb in the shoots of ryegrass by 22% and 25%, respectively. The concentration of Zn in the shoots of ryegrass from the first and the second harvests grown on soil A were in the range 1050â2000 mg kgâ1, making this plant a potential biomass to (i) produce biosourced catalysts for organic chemistry applications in a circular economy concept and (ii) limit human exposure to commercial Lewis acids. A preliminary application was identified. © 2019, Springer Nature Switzerland AG
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