In this letter, a variety of simple 6-chloro-4-(4-substituted piperazinyl)quinazoline derivatives was prepared. Preliminary bioassays revealed that these compounds showed good antibacterial activities toward phytopathogens Ralstonia solanacearum and Xanthomonas oryzae pv. oryzae (Xoo). Among these derivatives, compounds 5a, 5d, 5e, 5f, 5p, 5q, 6b, and 6d exhibited potent inhibition effects against R. solanacearum with EC50 within 4.60-9.94 µg/mL, especially, compound 5g exerted the strongest activity with EC50 of 2.72 µg/mL; compound 6b possessed the best inhibitory activity toward Xoo with EC50 of 8.46 µg/mL. Subsequently, a good predictive three-dimensional quantitative structure-activity relationship (3D-QSAR) model was constructed via CoMFA to direct the future structural modification and optimization. Furthermore, the pathogens' topological studies were performed to explore the possible antibacterial mechanism. Given their simple frameworks and facile synthesis, title compounds can serve as the potential antibacterial leads.

中文翻译：

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对青枯雷尔氏菌和米黄单胞菌的抗菌活性。6-氯-4-（4-取代的哌嗪基）喹唑啉衍生物的米杂。

在这封信中，制备了多种简单的6-氯-4-（4-取代的哌嗪基）喹唑啉衍生物。初步的生物测定表明，这些化合物对植物病原体Ralstonia solanacearum和Xanthomonas oryzae pv表现出良好的抗菌活性。稻（Xoo）。在这些衍生物中，化合物5a，5d，5e，5f，5p，5q，6b和6d在4.60-9.94 µg / mL范围内表现出对茄形青枯菌的强效抑制作用，尤其是化合物5g的EC50最强。 2.72微克/毫升; 化合物6b对Xoo具有最佳的抑制活性，EC50为8.46 µg / mL。随后，通过CoMFA构建了良好的预测性三维定量构效关系（3D-QSAR）模型，以指导未来的结构修改和优化。此外，病原体的 进行了拓扑研究，以探讨可能的抗菌机制。鉴于其简单的框架和容易的合成，标题化合物可以用作潜在的抗菌药。