New Efficient Eco-Friendly Supported Catalysts for the Synthesis of Amides with Antioxidant and Anti-Inflammatory Properties.

A new environmentally friendly approach for the synthesis of idrocilamide (1), a marketed myorelaxant and anti-inflammatory agent, is reported herein. The synthetic strategy involves a solvent-free aminolysis reaction catalyzed by zinc-containing species (ZnCl2 , montmorillonite K10 (MK10) impregnated with ZnCl2 or eco-catalysts). The latter have been prepared from the aerial parts of Lolium perenne L. plants grown on contaminated soils from northern France without and with thermal activation at 120 °C and supported on MK10 (Ecocat1 and Ecocat2, respectively). The best aminolysis catalysts in the current study (ZnCl2 and Ecocat2) were selected for additional aminolyses. Compared to ZnCl2 , Ecocat2 had the advantage of being reusable over five test runs and constituted a sustainable catalyst allowing a green route to idrocilamide. Synthesized derivatives 1-4, 6 and 9 were first evaluated for their effect on reactive oxygen species (ROS) generation from macrophages and displayed antioxidant properties by preventing ROS production. Next, the analysis of the effect of molecules 1-4, 6 and 9 on macrophage migration between epithelial cells to human opportunistic fungus Candida albicans indicated that molecules 2-4, 6 and 9 exert anti-inflammatory properties via reducing macrophage migration while the parent idrocilamide (1) did not show any significant effect. This work opens the way for the discovery of new analogues of idrocilamide with improved properties.

A sustainable approach to manage metal-contaminated soils: a preliminary greenhouse study for the possible production of metal-enriched ryegrass biomass for biosourced catalysts.

Two 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 1050-2000 mg kg-1, 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.

The potential of ryegrass (Lolium perenne L.) to clean up multi-contaminated soils from labile and phytoavailable potentially toxic elements to contribute into a circular economy.

Aided phytoremediation was studied for 48 weeks with the aim of reducing extractable and phytoavailable toxic elements and producing potential marketable biomass. In this sense, biomass of ryegrass was produced under greenhouse on two contaminated garden soils that have been amended with two successive additions of phosphates. After the first addition of phosphates, seeds of ryegrass were sown and shoots were harvested twice. A second seedling was performed after carefully mixing the roots from the first production (used as compost), soils and phosphates. Forty-eight weeks after starting the experiments, the concentrations of Cd, Pb, Zn, Cu, Fe, and Mn extracted using the rhizosphere-based method were generally lower than those measured before the addition of phosphates and cultivation (except for Pb and Fe in the most contaminated soil). The concentrations of metals in the shoots of ryegrass from the second production were lower than those from the first (except for Al). The best results were obtained with phosphates and were the most relevant in the lowest contaminated soil, demonstrating that the available metal concentrations have to be taken into account in the management of contaminated soils. In view of the concentration of metals defined as carcinogens, mutagens, and reprotoxics (e.g., Cd, Pb) and those capable to be transformed into Lewis acids (e.g., Zn, Fe), the utilization of ryegrass in the revegetation of contaminated soils and in risk management may be a new production of marketable biomass. The development of phytomanagement in combination with this type of biomass coincided with the view that contaminated soils can still represent a valuable resource that should be used sustainably.

From Conventional Lewis Acids to Heterogeneous Montmorillonite K10: Eco-Friendly Plant-Based Catalysts Used as Green Lewis Acids.

The concept of green chemistry began in the USA in the 1990s. Since the publication of the 12 principles of this concept, many reactions in organic chemistry have been developed, and chemical products have been synthesized under environmentally friendly conditions. Lewis acid mediated synthetic transformations are by far the most numerous and best studied. However, the use of certain Lewis acids may cause risks to environmental and human health. This Review discusses the evolution of Lewis acid catalyzed reactions from a homogeneous liquid phase to the solid phase to yield the expected organic molecules under green, safe conditions. In particular, recent developments and applications of biosourced catalysts from plants are highlighted.