Design, Synthesis, and Herbicidal Activity of Thioether Containing 1,2,4-Triazole Schiff Bases as Transketolase Inhibitors

Abstract

Transketolase (TK) represents a potential target for novel herbicide development. To discover novel TK inhibitors with potency against resistant weeds, 36 thioether compounds containing 1,2,4-triazole Schiff bases were designed and synthesized for herbicidal activity evaluation. The results demonstrated that compounds <b>5av</b> and <b>5aw</b> provided excellent weed control with inhibition of over 90% against the tested weeds, even at concentrations as low as 100 mg/L <i>in vitro</i>. In addition, compounds <b>5av</b> and <b>5aw</b> exhibited higher postemergence herbicidal activity than all of the positive controls against the tested weeds at 50-90 g [active ingredient (ai)]/ha in a greenhouse, while being safe for crops of maize and wheat at 90 g (ai)/ha. Fluorescent binding experiments of <i>At</i> TK indicated that compounds <b>5av</b> and <b>5aw</b> had strong TK inhibitory activity and could tightly bind with the enzyme <i>At</i> TK. Also, molecular docking analyses revealed that the structures of compounds <b>5av</b> and <b>5aw</b> were suitable for TK inhibitory activity. Taken together, these results suggested that compounds <b>5av</b> and <b>5aw</b> were promising herbicide candidates for weed control in wheat and maize fields targeting TK.