Diflumetorim is a member of pyrimidinamine fungicides that possess excellent antifungal activities. Nevertheless, as reported that the activity of diflumetorim to corn rust (Puccinia sorghi) was not ideal (EC50 = 53.26 mg/L). Herein, a series of novel pyrimidinamine derivatives containing phenyl-thiazole/oxazole moiety were designed based on our previous study and the structural characteristics of diflumetorim, synthesized and bioassayed to discover novel fungicides with excellent antifungal activities. Among these compounds, T18 gave the optimal fungicidal activity, which respectively offers control effects with EC50 values of 0.93 mg/L against P. sorghi and 1.24 mg/L against E. graminis, significantly superior to commercial fungicides diflumetorim, tebuconazole, and flusilazole. Cell cytotoxicity results suggested that compound T18 has lower toxicities than diflumetorim. Furthermore, DFT calculation indicated that the phenyl-thiazole/oxazole moiety plays an unarguable role in the improvement of activity, which will contribute to designing and developing more potent compounds in the future.

中文翻译：

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新型含苯基噻唑/恶唑基嘧啶胺衍生物的设计，合成和杀真菌活性评估。

地氟美林是嘧啶胺杀菌剂的成员，具有优异的抗真菌活性。然而，据报道，双氟甲蝶呤对玉米锈病（高粱）的活性并不理想（EC50 = 53.26 mg / L）。在此，根据我们先前的研究和双氟甲草胺的结构特征，设计合成了一系列含有苯基-噻唑/恶唑部分的新型嘧啶胺衍生物，并对其进行了生物测定并进行了生物测定，以发现具有优异抗真菌活性的新型杀菌剂。在这些化合物中，T18具有最佳的杀真菌活性，分别对高粱P.orghi和E. graminis的EC50值为0.93 mg / L和1.24 mg / L，具有明显优于商业杀真菌剂diflumetorim，tebuconazole和flusilazole的防治效果。细胞的细胞毒性结果表明，化合物T18的毒性低于双氟甲蝶呤。此外，DFT计算表明，苯基噻唑/恶唑部分在活性提高中起着不可争辩的作用，这将有助于将来设计和开发更有效的化合物。