Discovery of Novel Pyrazol-5-yl-benzamide Derivatives Containing a Thiocyanato Group as Broad-Spectrum Fungicidal Candidates

作者：Yantao Li, Han Yang, Yidan Ma, Yuan Cao, Dan Xu, Xili Liu, Gong Xu · 发表于：Journal of Agricultural and Food Chemistry · 年份：2023 · DOI：10.1021/acs.jafc.3c04869 · 被引用次数：21 · 研究领域：Fungal Plant Pathogen Control、Synthesis and biological activity、Phytochemical compounds biological activities

In an effort to promote the development of new fungicides, a series of 48 novel N -(1-methyl-4-thiocyanato-1 H -pyrazol-5-yl)-benzamide derivatives A1 – A36 and B1 – B12 were designed and synthesized by incorporating a thiocyanato group into the pyrazole ring, and their fungicidal activities were evaluated against Sclerotinia sclerotiorum, Valsa mali, Botrytis cinerea, Rhizoctonia solani, and Phytophthora capsici . In the in vitro antifungal/antioomycete assay, many of the target compounds exhibited good broad-spectrum fungicidal activities. Among them, compound A36 displayed the best antifungal activity against V. mali with an EC 50 value of 0.37 mg/L, which was significantly higher than that of the positive controls fluxapyroxad (13.3 mg/L) and dimethomorph (10.3 mg/L). Meanwhile, compound B6 exhibited the best antioomycete activity against P. capsici with an EC 50 value of 0.41 mg/L, which was higher than that of azoxystrobin (29.2 mg/L) but lower than that of dimethomorph (0.13 mg/L). Notably, compound A27 displayed broad-spectrum inhibitory activities against V. mali, B. cinerea, R. solani, S. sclerotiorum, and P. capsici with respective EC 50 values of 0.71, 1.44, 1.78, 0.87, and 1.61 mg/L. The in vivo experiments revealed that compounds A27 and B6 presented excellent protective and curative efficacies against P. capsici, similar to that of the positive control dimethomorph . Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed t...