New insecticides discovered from herbicides

Chinese researchers have identified herbicides based on diphenyl ethers as potential inhibitors of trehalase, an enzyme essential for energy metabolism in insects.

The discovery suggests the possibility of a new mechanism for controlling agricultural pests.

Research summary

The work focused on the enzyme trehalase, responsible for the conversion of trehalose into glucose, crucial for energy and chitin synthesis in insects.

The study explored two herbicide-derived compounds—bifenox and chlomethoxyfen—as non-carbohydrate inhibitors of this enzyme. These compounds were shown to effectively inhibit trehalase and reduce glucose in treated insects.

The results indicated that bifenox and chlomethoxyfen not only retarded the growth of pest larvae but Ostrinia furnacalis, but also caused high mortality in locusts, with rates exceeding 60%.

Development and results

• Identification of compounds: Using virtual screening and biological assays, scientists tested more than 48 compounds. Bifenox and chlomethoxyfen emerged as the most promising, with competitive inhibition mechanisms on the enzyme.

• Biological evaluation: in locusts fed on treated plants, there was a significant decrease in mobility and hemolymph glucose levels, followed by mortality. This suggests interruption in the insects' main energy supply pathway.

• Practical applications: Both compounds are widely known herbicides used for weed control. This discovery extends their application to integrated pest management, combining control of invasive plants and insects.

Impact on the agricultural sector

The use of diphenyl ether-based trehalase inhibitors could represent a paradigm shift in pest management. Since these compounds are already commercially available, adapting them for insect control could reduce development costs and accelerate adoption. Furthermore, since humans do not possess trehalase, these products appear to pose a low risk of impact on human health.

Next Steps

The researchers indicate that further studies should optimize the chemical structure of the compounds for greater efficacy and specificity. There is also the possibility of combining these inhibitors with environmentally sustainable application techniques.

More information can be found at doi.org/10.1016/j.aac.2024.12.001