5-甲基异噁唑-4-甲酸肟酯衍生物的合成及抑菌活性

Synthesis and antifungal activity of 5-methylisoxazole-4-carboxylic oxime esters

摘要: 异噁唑是具有较好活性的五元杂环，本文设计并合成了15个5-甲基异噁唑-4-甲酸肟酯类新化合物，利用核磁氢谱、核磁碳谱和高分辨质谱对其结构进行确证，并测试了其对番茄灰霉病菌Botrytis cinerea、水稻纹枯病菌Rhizoctonia solani、苹果树腐烂病菌Valsa mali和小麦全蚀病菌Gaeumannomyces graminis的离体抑菌活性。结果表明，在50 μg/mL下，目标化合物对供试病原菌均有一定的抑菌活性，其中化合物 5g 对番茄灰霉病菌的抑制活性优于先导化合物 L1 和肟菌酯，EC₅₀值为1.95 μg/mL。

Abstract: Isoxazole is a five-membered heterocycle with good activity. Fifteen new 5-methylisoxazole-4-carboxylic oxime esters were designed and synthesized in this paper. Their structures were determined by ¹H NMR, ¹³C NMR and HRMS. The in vitro antifungal activities against Botrytis cinerea, Rhizoctonia solani, Valsa mali and Gaeumannomyces graminis were evaluated. The bioactivity results showed that the target compounds had certain antifungal activities at the concentration of 50 μg/mL. Particularly, compound 5g displayed better activity against B. cinerea than lead compound L1 and trifloxystrobin with an EC₅₀ value of 1.95 μg/mL.