[Protecting biodiversity and sustainable sciences]. / Protection de la biodiversité et sciences durables.

The latest IPBES report clearly showed that pollution and proliferation of invasive alien species constituted two of the five major factors responsible for the biodiversity decline. Faced with this situation, we present here the development of nature-based solutions in response to these two challenges. This approach has firstly made it possible to progress in understanding the adaptation strategies of plants and associated micro-organisms to respond to attacks such as pollution. Thus, relevant studies showed that certain plant species are able to grow in environments contaminated with metallic elements, or even to sequester toxic pollutants in their leaves or their roots. This research has made it possible to provide original solutions for the ecological restoration of soils and the decontamination of aquatic systems using dead invasive exotic plant species. The promotion of these solutions through the concept of ecocatalysis, at the interface of ecology and chemistry, contributed to make them sustainable and economically viable.

Title: Protection de la biodiversité et sciences durables. Abstract: Le dernier rapport de l'IPBES a clairement montré que la pollution et la multiplication des espèces exotiques envahissantes constituaient deux des cinq facteurs majeurs responsables du déclin de la biodiversité. Face à cette situation, nous présentons dans cette brève revue le développement de solutions fondées sur la nature pour répondre à ces deux défis. Cette approche a tout d'abord permis de progresser dans la compréhension des stratégies d'adaptation des plantes et des microorganismes associés, pour répondre à des agressions telles que celle de la pollution. Ainsi, il a pu être démontré que certaines espèces végétales sont capables de se développer dans des milieux contaminés par des éléments métalliques, voire de séquestrer les polluants toxiques dans leurs feuilles ou leurs racines. Ces recherches ont permis d'apporter des solutions originales pour la restauration écologique des sols et la décontamination des systèmes aquatiques à l'aide d'espèces végétales exotiques envahissantes mortes. Afin de les rendre pérennes et économiquement viables, ces solutions ont été valorisées à travers le concept de l'écocatalyse, à l'interface de l'écologie et de la chimie.

New Sustainable Synthetic Routes to Cyclic Oxyterpenes Using the Ecocatalyst Toolbox.

Cyclic oxyterpenes are natural products that are mostly used as fragrances, flavours and drugs by the cosmetic, food and pharmaceutical industries. However, only a few cyclic oxyterpenes are accessible via chemical syntheses, which are far from being ecofriendly. We report here the synthesis of six cyclic oxyterpenes derived from ß-pinene while respecting the principles of green and sustainable chemistry. Only natural or biosourced catalysts were used in mild conditions that were optimised for each synthesis. A new generation of ecocatalysts, derived from Mn-rich water lettuce, was prepared via green processes, characterised by MP-AES, XRPD and TEM analyses, and tested in catalysis. The epoxidation of ß-pinene led to the platform molecule, ß-pinene oxide, with a good yield, illustrating the efficacy of the new generation of ecocatalysts. The opening ß-pinene oxide was investigated in green conditions and led to new and regioselective syntheses of myrtenol, 7-hydroxy-α-terpineol and perillyl alcohol. Successive oxidations of perillyl alcohol could be performed using no hazardous oxidant and were controlled using the new generation of ecocatalysts generating perillaldehyde and cuminaldehyde.

Biosourced Polymetallic Catalysis: A Surprising and Efficient Means to Promote the Knoevenagel Condensation.

Zn hyperaccumulator (Arabidobsis halleri) and Zn accumulator Salix "Tordis" (Salix schwerinii × Salix viminalis) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore a novel methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the use of polymetallic salts derived from plants as bio-based catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) in order to precise the chemical composition, structure, and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to usual catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis.