LAUSR

BACKGROUND chlorsulfuron, metsulfuron-methyl, and ethametsulfuron can damage sensitive crops in rotation pattern due to their long persistence in soil. To explore novel sulfonylurea (SU) herbicides with favorable soil degradation rates, four series of SUs were synthesized through a structure-based drug design (SBDD) strategy. RESULTS the target compounds, especially Ia, Id, and Ie, exhibited prospective herbicidal activity against dicotyledon oil seed rape (Brassica campestris), amaranth (Amaranthus retroflexus), monocotyledon barnyard grass (Echinochloa crusgalli), and crab grass (Digitaria sanguinalis) at a concentration of 15 a.i. g·ha-1 . Additionally, Ia, Id and Ig displayed excellent inhibitory effects against AtAHAS, with Kapp i values of 59.1, 34.5, and 71.8 μM, respectively, which were much lower than that of chlorsulfuron at 149.4 μM. The π-π stack and H-bonds between the Ia conformation and AtAHAS in the molecular docking results confirmed the series of compounds to be conventional AHAS inhibitors. In alkaline soil (pH=8.46), compounds Ia-Ig revealed various degrees of acceleration in the degradation rate compared with chlorsulfuron. Besides, compound Ia showed considerable wheat and corn safety under postemergence at the concentration of 30, 60, and even 120 a.i. g·ha-1 . CONCLUSION overall, considering the synthetic procedure, herbicidal activity, soil degradation, and crop safety, the series sulfonylureas of Ia were investigated to be prospective as AHAS inhibitors. The 5-dimethylamino group on SUs accelerated degradation rate at different levels in alkaline soils which seems to be controllable in conventional cropping systems in their further application. This article is protected by copyright. All rights reserved.