Discovery of Chiral Diamine Derivatives Containing 1,2-Diphenylethylenediamine as Novel Antiviral and Fungicidal Agents

Severe plant virus diseases lead to poor harvests andpoor cropquality, and the lack of effective suppressive drugs makes plant diseasecontrol a huge challenge. Natural product-based structural simplificationis an important strategy for finding novel pesticide candidates. Accordingto our previous research on the antiviral activities of harmine andtetrahydroharmine derivatives, a series of chiral diamine compoundswere designed and synthesized by means of structural simplificationusing diamines in natural products as the core structure in this work,and the antiviral and fungicidal activities were investigated. Mostof these compounds displayed higher antiviral activities than thoseof ribavirin. Compounds 1a and 4g displayedhigher antiviral activities than ningnanmycin at 500 & mu;g/mL.The antiviral mechanism research revealed that compounds 1a and 4g could inhibit virus assembly by binding to tobaccomosaic virus (TMV) CP and interfere with the assembly process of TMVCP and RNA via transmission electron microscopy andmolecular docking. Further fungicidal activity tests showed that thesecompounds displayed broad-spectrum fungicidal activities. Compounds 3a, 3i, 5c, and 5d withexcellent fungicidal activities against Fusarium oxysporum f.sp. cucumerinum can be considered as new fungicidalcandidates for further research. The current work provides a referenceto the development of agricultural active ingredients in crop protection.