Assessing the Environmental Risks of Sulfonylurea Pollutants: Insights into the Risk Priority and Structure-Toxicity Relationships Explorations

Abstract

Nowadays, sulfonylurea herbicides are the popularly used agrochemicals worldwide, but the health threats of the pollutants are still unclear. This story used fuzzy clustering to rank 44 sulfonylurea pollutants in risk priority and then explored the structure-toxicity relationships of sulfonylurea pollutants. The findings exhibit that 44 sulfonylurea pollutants can be clustered into 3 risk priorities (level I＜level II＜level III) and the pecking order (104 M-1) of the protein’s affinity is consistent with the risk priority ranking. Meantime, toxic conjugations causes marked changes in protein conformation, and the higher the risk priority, the greater the conformational changes, which was confirmed by the quantitative data of circular dichroism. Since the conformations of sulfonylurea pollutants are very similar in the reaction domain, the patterns of toxic action present a high degree of similarity. Structure-toxicity relationships analyses display that there is a positive correlation between Gibbs free energy (ΔG°), affinity, the logKow and risk priority, and the larger the ΔG°, the stronger the affinity, or the greater the logKow, the higher the risk. The electronegativity of the aromatic ring on the left side of sulfonylurea pollutants is the determinant that affects the affinity, and the greater the electronegativity, the weaker the affinity, and the smaller the risk; when the left aromatic ring is consistent, the stronger the electronegativity of the right heterocyclic ring, the larger the affinity, and the higher the risk. Undoubtedly, this scenario could contribute a mechanistic basis to assessing the health hazards of exposure to sulfonylurea pollutants.

Keywords: Sulfonylurea pollutants, Protein's affinity, Structure-toxicity relationships, Risk priority, Profiles of toxic action