Design, Synthesis, and Herbicidal Activity of Indole-Containing Fusarium Acid Derivatives Targeting Transketolase

Transketolase (TKL; EC 2.2.1.1) has been validated as a potential new herbicide target. To develop a new and highly effective herbicides-targeted TKL, a series of indole-containing fusarium acid (FA) derivatives 9a-9s were designed and synthesized. Among them, compound 9o exhibited more excellent herbicidal activity against Digitaria sanguinalis and Amaranthus retroflexus (inhibition > 90%) compared to the positive controls at 375 g ai/ha. Furthermore, compound 9o was safe for maize and wheat (phytotoxicity 5%) at 375 g ai/ha. Also, compound 9o exhibited a slightly better inhibition effect against Setaria viridis (Sv)TKL than that of the positive control (IC50: 0.229, 0.420 mg/L). Molecular docking and molecular dynamics simulations (MDS) indicated that the binding between SvTKL and 9o is stronger. Moreover, SvTKL-9o has more favorable binding residues including SER101, ARG169, PHE512, HIS539, and ARG598. These results have guiding significance for the molecular design of higher herbicidal activity compounds targeting TKL.