Abstract

A series of novel pyrazole-4-carboxamides were rationally designed, synthesized, and their structures were characterized by ¹H NMR, ¹³C NMR and HRMS. Preliminary bioassay showed that four compounds 8g, 8j, 8o and 8s exhibited more than 90% and even completed inhibition against Alternaria solani at 100 μg/mL; and 8d displayed 100% inhibition against Fusarium oxysporum at the same concentration. Moreover, 8j exhibited good in vitro fungicidal activity against A. solani with EC₅₀ value of 3.06 μg/mL, and it also displayed completed in vivo protective antifungal activity against A. solani on tomato at 10 mg/L, as boscalid did. The molecular docking results indicated that 8j exhibited the high affinity with SDH protein by H-bond and π–π stacking interactions, which may explain the reasons for its good activities. These data support that compound 8j could be used as a fungicide candidate for further study.

Graphic abstract

A practical method for the synthesis of pyrazole-4-carboxamides were provided and evaluation of their antifungal activities.

中文翻译：

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作为潜在候选杀菌剂的吡唑-4-甲酰胺的合成。

 抽象的

合理设计、合成了一系列新型吡唑-4-甲酰胺，并通过¹ H NMR、 ¹³ C NMR 和 HRMS 对其结构进行了表征。初步生物测定表明， 8g 、 8j 、 8o 、 8s​​ 4个化合物在100 μg/mL浓度下对茄斑病菌的抑制率达到90%以上甚至完全； 8d在相同浓度下对尖孢镰刀菌的抑制率为100%。此外， 8j对茄病菌表现出良好的体外杀菌活性，EC ₅₀值为3.06 μg/mL，并且与啶酰菌胺一样，在10 mg/L浓度下对番茄也表现出完整的体内抗茄病菌保护性抗真菌活性。分子对接结果表明， 8j通过H键和π - π堆积相互作用与SDH蛋白表现出高亲和力，这可能解释了其良好活性的原因。这些数据支持化合物8j可以作为候选杀菌剂进行进一步研究。

 图文摘要

提供了一种实用的吡唑-4-甲酰胺的合成方法并评价其抗真菌活性。