IPP·CAAS revealed the action metabolism of Chinese novel pesticide Cyetpyrafen

Recently, a team from IPP·CAAS, published a paper, which is entitled "Insight into the uptake and metabolism of a new insecticide cyetpyrafen in plants” in Environment International. In this paper, the uptake and metabolism of Cyetpyrafen in crops were systematically described for the first time, and the physicochemical properties and ecotoxicity of its metabolism were predicted and evaluated, which provided ideas and guidance for the study of metabolic mechanism of new pesticides.

Cyetpyrafen is a novel insecticide and acaricide created in China, which can effectively control a variety of pests and mites in horticulture and crops, and has been widely used in China. However, the mechanism of uptake, elimination kinetics and transformation of its parent and metabolites in crops is not clear, which hinders the accurate evaluation of its application risk.

In this study, the uptake and elimination kinetics and transformation of Cyetpyrafen, in two model crops (lettuce and rice) were first evaluated by hydroponic experiments. The study suggested that root uptake of Cyetpyrafen was likely to be dominated by passive diffusion and was difficult to transport via xylem and phloem.

Ten phase I and three phase II metabolites of Cyetpyrafen were tentatively identified in the hydroponic-plant system through a nontarget screening strategy.

The metabolic pathways include hydroxylation, hydrolysis, dehydrogenation, dehydration and conjugation. It was revealed that Cytochrome P450, Carboxylesterase, Glycosyltransferase, Glutathione S-transferases and Peroxidase were involved in the metabolism of Cyetpyrafen in crops.

It was predicted that the phase I metabolites of Cyetpyrafen had high toxicity to aquatic organisms, and the metabolites M-391, M-409-1, M-409-2 and M-407 had similar toxicity levels to the mother.

The results provided important basic data for the efficient and safe application of Cyetpyrafen, and provided methodological and technical reference for the study of metabolic behavior mechanism of new pesticides in crops.