Enantioseparation, bioactivity, environmental fate and toxicity of chiral triazole fungicide ipconazole in soil and earthworm

Ipconazole (IPC) is a chiral triazole fungicide and commonly used for disease control in seeds. This study investigated the bioactivity and potential mechanism of ipconazole against pathogenic microorganisms at the chiral perspective. It explored the accumulation behavior of ipconazole enantiomers within the soil-earthworm system and evaluated its toxic effects on earthworms. Bioactivity evaluation revealed that the bioactivity order of ipconazole against three plant pathogens is (−)-1S,2 R,5S-IPC > rac-IPC > (+)-1R,2S,5R-IPC, and the bioactivity of (−)-1S,2 R,5S-IPC is 34.6-129.5 times higher than that of (+)-1R,2S,5R-IPC. Molecular docking found that (−)-1S,2 R,5S-IPC has a stronger binding affinity for the target protein CYP51 to cause activity differences. Accumulation and metabolism studies revealed that (−)-1S,2 R,5S-IPC is more persistent than that of (+)-1R,2S,5R-IPC, and ipconazole was primarily metabolized into hydroxylated ipconazole through hydroxylation in the soil-earthworm system. Toxicological evaluation found growth inhibitory effects and histopathological damage to earthworms at an exposure concentration of 1.5 mg kg^-1 ipconazole. Further investigation indicated that these toxic effects of ipconazole were caused by inducing oxidative damage and influencing the functional gene expression of related growth. These research findings will further enhance the understanding of the activity and risks of ipconazole enantiomers, contributing to the safer use of ipconazole in the agricultural environment.