High Activity and Easily Hydrolyzable Sulfonylurea Inhibitor Design Based on Density Functional Theory Calculations

Abstract

To find new sulfonylurea inhibitors with high efficacy and fast hydrolysis degradation rate, a few compounds were first designed based on the commercial product Chlorimuron-Ethyl (CE) by estimating the binding interaction between the inhibitor and the Acetohydroxyacid Synthase (AHAS) using the quantum mechanical approach. Meanwhile, the activation energy barriers of hydrolysis for the sulfonylurea inhibitors with the amino and nitro groups onto para position of the benzene ring were calculated. Based on the calculated binding interaction energy and hydrolysis energy barrier, six new sulfonylurea inhibitors I1–I6 were designed and synthesized. By measuring the half-lives through hydrolysis degradation assay, it was indicated that the compounds I1–I3 with the introduction of an amino group at the fourth position of benzene ring show much faster degradation rate than those compounds with nitro groups, which is in a good agreement with the calculated results for hydrolysis barrier. The herbicide activity tests show that the compounds I1 and I2 remained excellent herbicidal activity on both broadleaf weeds with soil treatment at a concentration about 150[Formula: see text]mg/l. Due to their short half-lives of chemical hydrolysis and high herbicidal activities, compounds I1 and I2 could be potential herbicidal candidates in the future, which are helpful for the sustainable development of the environment and ecology.