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 and their herbicidal activities against rape was analyzed using physicochemical parameters and regression analysis. The results showed that the electronic properties of the molecules are the dominant factor to the activity and there is apparently an optimum electronic property (∑σ or pKa) for the molecules to fit the receptor. Combined with the previous QSAR results for herbicidal triazolopyrimidine-2-sulfonamides, we can conclude that the structure-activity relationships of these two sets of compounds are identical, which suggested that these two sets of compounds acted on the same target site.     

STRUCTURAL RULES OF TRANSITIONMETAL CARBONYL COMPOUNDS

In this article we have proposed two topological rules to account for the electronic structures of transition-metal carbonyl compounds. The second rule is applied to those which have polyhedral metalhc skeletons with triangular faces and their derivates, while the first rule is applied to all the others We have used these two rules to analyze 261 structure-known compounds with the number of metal atoms from 2 to 12, and the results show that the two rules are in good agreement with the experimental facts. Furthermore, we have also derived from the second rule a formula which can be used to account for the electronic structures of closedpacking carbonyl compounds and which is the same as that given by Ciani and his coworkers.