Many phytopathogenic fungi cause severe damage to crop yields. In continuation of our research aimed at the discovery and development of natural products-based fungicides, a series of thirty-one sarisan attached 3-phenylisoxazolines were synthesized and evaluated for their antifungal activities against five phytopathogenic fungi ( B. cinerea , C. lagenarium , A. solani , F. solani , and F. graminearum ). Among all title sarisan derivatives, compounds IV2 , IV14 and IV23 showed potent antifungal activity against some phytopathogenic fungi. In particular, compound IV2 exhibited a broad-spectrum and more potent antifungal activity against A. solani , F. solani , and F. graminearum than the commercial fungicide Hymexazol. In addition, compounds IV2 , IV14 and IV23 also displayed relative low toxicity on normal NRK-52E cells. This work will give some insights into the development of sarisan derivatives as new fungicide candidates in plant protection. Graphical
A series of sarisan analogs containing 1,3,4-oxadiazole moieties were synthesized by iodine-mediated oxidative cyclization and screened in vitro for their antifungal activities at 50 μg/mL against five phytopathogenic fungi such as Valsa mali , Curvularia lunata , Alternaria alternate , Fusarium solani and Fusarium graminearum . 1,3,4-Oxadiazole derivatives 7e , 7p , 7r , 7t and 7u exhibited potent and a broad spectrum of antifungal activities against at least three phytopathogenic fungi at the concentration of 50 μg/mL. Especially, compound 7r displayed more potent antifungal activities against five phytopathogenic fungi than the positive control hymexazol. The EC 50 of 7r against V. mali , C. lunata and A. alternate were 12.6, 14.5 and 17.0 μg/mL, respectively. Additionally, some interesting results of structure-activity relationships (SARs) were also observed.