Radulanin A, a new natural herbicide
Researchers at École Polytechnique's Organic Synthesis Laboratory have synthesized a natural molecule known as radulanin A, from a species of moss. The molecule’s herbicidal properties are similar to those found in the controversial product, glyphosate.
In developing a synthesis methodology using a particular chemical reaction (retro-Claisen rearrangement), Bastien Nay, a research director at the Organic Synthesis Laboratory, and his student Wei Zhang were able to synthesize the structure of the natural molecule radulanin A.
Basing his theory on the structural similarity of radulanin A and lunularic acid, another naturally occurring molecule with phytotoxic properties, Bastien Nay estimated that radulanin A could also have herbicidal characteristics. To test his hypothesis, he got in touch with Emmanuel Baudouin, a colleague from Sorbonne University specializing in plant biology.
Emmanuel Baudouin placed the molecule in a substrate for growing Arabidopsis thaliana, a plant commonly considered as a weed in agriculture.
When exposed to an active dose of radulanin A similar to the amount that would be used for other herbicides like glyphosate, the Arabidopsis thaliana seedlings wilted, proving the molecule’s herbicidal properties.
Before considering the use of this natural molecule to replace synthetic herbicides currently on the market, scientists must first study the toxic effects of radulanin A on the environment and the food chain. These studies will be accompanied by further research into the molecule’s biological mechanisms, in order to find the most efficient compound according to the type of culture.
The l’X Molecular Chemistry Laboratory is also involved in this research, with Gilles Frison having already modeled the synthesis reaction required to obtain radulanin A, and Marie Cordier having carried out research on structural resolution.
More details on this research can be found in an article co-authored by researchers from CNRS, École Polytechnique and Sorbonne University, available online in Chemistry: A European Journal.
Bibliography: One-Pot Synthesis of Metastable 2,5-Dihydrooxepines Through Retro-Claisen Rearrangements: Methods and Applications. W. Zhang, E. Baudouin, M. Cordier, G. Frison and B. Nay., Chemistry: A European Journal, April 29, 2019.