Design, Synthesis, Anti-Tomato Spotted Wilt Virus Activity, and Mechanism of Action of Thienopyrimidine-Containing Dithioacetal Derivatives.

Currently, there is insufficient viricide to effectively control tomato spotted wilt virus (TSWV). To address this pending issue, a series of thienopyrimidine-containing dithioacetal derivatives were prepared and tested for their anti-TSWV activities. A subsequent three-dimensional quantitative structure-activity relationship was constructed to indicate the development of optimal compound 35 . The obtained compound 35 had excellent anti-TSWV curative, protective, and inactivating activities (63.0, 56.6, and 74.1%, respectively), and the EC 50 values of protective and inactivating activities of compound 35 were 252.8 and 113.5 mg/L, respectively, better than those of ningnanmycin (284.8 and 144.7 mg/L) and xiangcaoliusuobingmi (624.9 and 300.0 mg/L). In addition, the anti-TSWV activity of compound 35 was associated with defense-related enzyme activities, enhanced photosynthesis, and reduced stress response, thereby enhancing disease resistance.