Synthesis, Biological Evaluation, and Molecular Docking of Novel Ferulic Acid Derivatives Containing a 1,3,4-oxadiazole Thioether and Trifluoromethyl Pyrimidine Skeleton

In this study, 24 novel ferulic acid derivatives containing 1,3,4-oxadiazole thioether and trifluoromethyl pyrimidine were designed and synthesized. Bioactivity assay showed that some of the target compounds exhibited moderate to good antifungal activity against BD), sp. (PS), (BC), spp. (FS), (FG), and sp. (CS). Especially, compound 6f demonstrated superior antifungal activity against sp., with an EC value of 12.64 μg mL, outperforming pyrimethanil (35.16 μg mL) and hymexazol (27.01 μg mL). Meanwhile, compound 6p showed strong antibacterial activity against pv. citri (XAC) , with an inhibition ratio of 85.76%, which was higher than thiodiazole copper's 76.59% at 100 μg mL. Furthermore, molecular docking simulations elucidated that compound 6f engaged in hydrogen bonding with the succinate dehydrogenase (SDH) enzyme at SER-17, SER-39, ARG-14 and ARG-43 sites, clarifying its mode of action. This study highlights the potential of these novel ferulic acid derivatives as promising agents for controlling fungal and bacterial threats to plant health. To the best of our knowledge, this study represents the first report on the antifungal and antibacterial properties of ferulic acid derivatives containing 1,3,4-oxadiazole thioether and trifluoromethyl pyrimidine skeleton.