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 EC50 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.