Design, synthesis and bioactivity of novel herbicides targeted ALS (VII): Quantitative structure-activity relationships of herbicidal sulfonylureas

The quantitative relationship between the structures of 20 sulfonylureas an d their herbicidal activities against rape was analyzed using physicochemic al parameters and regression analysis. The results showed that the electron ic properties of the molecules are the dominant factor to the activity and there is apparently an optimum electronic property (Sigma sigma or pK(a)) f or the molecules to fit the receptor. Combined with the previous QSAR resul ts for herbicidal triazolopyrimidine-2-sulfonamides, we can conclude that t he structure-activity relationships of these two sets of compounds are iden tical, which suggested that these, two sets of compounds acted on the same target site.