Design, synthesis, herbicidal activity, in vivo enzyme activity evaluation and molecular docking study of acylthiourea derivatives as novel acetohydroxyacid synthase inhibitor

Abstract In order to develop novel herbicides, a series of novel acylthiourea derivatives containing methylsulfone were synthesized and characterized by melting point, elemental analysis, infrared spectroscopy, mass spectrometry and 1H NMR spectroscopy. Furthermore, the preliminary herbicidal activity of title compounds was determined against Echinochloa crusgal, Polypogon fugax, Digitaria adscendens, Brassica napus, Amaranthus retroflexus and Abutilon theophrasti. The results of the petri dish experiments showed that a small part of title compounds had a good inhibitory effect on Digitaria adscendens and Brassica napus. The results of the greenhouse herbicidal activity experiments indicated that the compounds 4p, 4w and 4x exhibited more high herbicidal activity against Brassica napus and Digitaria adscendens than the commercial herbicide bensulfuron-methyl. Moreover, except for compound 4i, all test compounds performed well in crop safety evaluation. Next, acetohydroxyacid synthase (AHAS) enzyme activity experiments were carried out, and the results showed that compound 4x had the highest inhibition rate reaching 89.12%. Finally, in order to screen AHAS inhibitor, molecular docking was performed by using AHAS protein and target ligand molecules 4a-4x. The results of molecular docking were similar to bioassay experiments. Compound 4p, 4w and 4x were considered potential AHAS inhibitors.