Synthesis and Antifungal Activity of Chimonanthus praecox Derivatives

To search for efficient agricultural antifungal lead compounds, 39 Chimonanthus praecox derivatives were designed, synthesized, and evaluated for their antifungal activities. The structures of target compounds were fully characterized by (1)H NMR, (13)C NMR, and MS spectra. The preliminary bioassays revealed that some compounds exhibited excellent antifungal activities in vitro. For example, the minimum inhibitory concentration (MIC) of compound b15 against Phytophthora infestans was 1.95 µg mL(−1), and the minimum inhibitory concentration (MIC) of compound b17 against Sclerotinia sclerotiorum was 1.95 µg mL(−1). Therefore, compounds b15 and b17 were identified as the most promising candidates for further study.