Chemists and biologists from the CNRS, École Polytechnique and Sorbonne University have just highlighted the phytotoxic nature of a natural molecule, radulanine A (1). This work has also been the subject of a doctoral thesis in chemistry.
This molecule has a low active dose herbicidal effect, close to that of glyphosate, the herbicide of reference. It remains to test its harmlessness for man and the environment.
► What is this molecule?
Radulanin A is a compound produced by a Radula-type moss, a primitive land-based plant with no roots and sap-conducting vessels, but small filaments that allow it to cling to soil, rocks or tree trunks. trees. Loving wet undergrowth, it is able to withstand drying.
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Very simple, its leaves have only one to three layers of cells. " In nature, it is likely that this foam secretes radulanin A in case of competition vis-à-vis other plant species "Says Bastien Nay, chemist at the synthesis chemistry laboratory (CNRS-Ecole Polytechnique) and head of the team.
► How was it synthesized?
The radulanine A is naturally present in the leaves. " It is a fairly simple, cyclic molecule consisting of 7 carbon atoms and one oxygen atomexplains Bastien Nay, a pharmacist by training. However, it exists in very small quantities. Hence the idea of trying to synthesize it in the laboratory. What we managed to do, low environmental impact: in one step, saving energy, and without using a metal catalyst "Continues the chemist.
Synthetic chemistry has made it possible to obtain more radulanine A for the scientists, one can imagine that one day one could amplify the reaction to obtain very large quantities likely to be valorized in agriculture.
► How would it work in agriculture?
To identify its effect, the researchers added radulanine A to the culture medium of a model plant, the cress of the ladies. As a result, the guinea-pig plant quickly yellowed before dying, proving the herbicidal effect of radulanine A. " This, at a low active dose, close to that of glyphosate, the herbicide of reference ", Observes Bastien Nay. Therefore, radulanine may have a lower environmental impact than currently used synthetic herbicides.
" Glyphosate is a simple molecule, derived from an amino acid, low in toxicity, easily degradable, easy to synthesize, cheap. But he has bad press, he is socially unacceptable and he should eventually be banned, observes Bastien Nay. In this context, we have a chance to value this product, but it will not be for many years. "
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A patent application on the molecule and its potential herbicidal use has been filed. For the future, scientists will first test the potential toxic effects of this molecule vis-à-vis humans and the environment. They then consider more precisely the mechanisms of the herbicidal effect of radulanine A and better identify the plant species that would be the target.