Design, Synthesis, and Antifungal Activities of Novel Potent Fluoroalkenyl Succinate Dehydrogenase Inhibitors.

The development of new fungicide molecules is a crucial task for agricultural chemists to enhance the effectiveness of fungicides in agricultural production. In this study, a series of novel fluoroalkenyl modified succinate dehydrogenase inhibitors were synthesized and evaluated for their antifungal activities against eight fungi. The results from the antifungal assay demonstrated that compound exhibited superior activity against with an EC value of 0.04 μM, outperforming commercial fluxapyroxad (EC = 0.18 μM) and boscalid (EC = 3.07 μM). Furthermore, compound showed similar effects to fluxapyroxad on other pathogenic fungi such as (EC = 1.13 μM), (EC = 1.61 μM), (EC = 1.21 μM), and also demonstrated protective and curative efficacies on rapeseed leaves and tomato fruits. Enzyme activity experiments and protein-ligand interaction analysis by surface plasmon resonance revealed that compound had a stronger inhibitory effect on succinate dehydrogenase compared to fluxapyroxad. Additionally, molecular docking and DFT calculation confirmed that the fluoroalkenyl unit in compound could enhance its binding capacity with the target protein through p-π conjugation and hydrogen bond interactions.