Discovery of Natural Product-Based Fungicides (II): Semisynthesis and Biological Activity of Sarisan Attached 3-Phenylisoxazolines as Antifungal Agents

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