A series of novel 6-sulfonyl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were designed and synthesized. CoMFA models were established to analyze the quantitative structure–activity relationships on the basis of the EC₅₀ values of the compounds. The models were used to design and synthesize compounds 32 and 33 with higher activities. The EC₅₀ values of compound 33 against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) were 0.59 and 1.63 mg/L, respectively, which were higher than those of thiodiazole copper (90.43 and 97.93 mg/L) and bismerthiazol (68.37 and 75.59 mg/L). Moreover, protective activities of compound 33 against bacterial leaf streak (BLS) and bacterial leaf blight (BLB) were 49.65% and 49.42%, respectively, which were superior to those of thiodiazole copper (44.28% and 41.51%) and bismerthiazol (38.89% and 40.09%). Protective activity of compound 33 against BLS was closely related to the improvement of defense-related enzyme activities, chlorophyll content, and photosynthesis activation. This is consistent with the upregulated expression of defense responses and photosynthesis-related proteins.

中文翻译：

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新型6-磺酰基-1,2,4-三唑[3,4- b ] [1,3,4]噻二唑衍生物的合成，抗菌活性及机理

设计并合成了一系列新颖的6-磺酰基-1,2,4-三唑并[3,4- b ] [1,3,4]噻二唑衍生物。建立了CoMFA模型，以根据化合物的EC ₅₀值分析定量的构效关系。该模型用于设计和合成具有较高活性的化合物32和33。化合物33对米黄单胞菌PV的EC ₅₀值。米（Xoo）和黄单胞菌（Xanthomonas oryzae）。空心稗（XOC）分别为0.59和1.63 mg / L，分别高于硫代二唑铜（90.43和97.93 mg / L）和比美噻唑（68.37和75.59 mg / L）。此外，化合物33对细菌叶斑纹（BLS）和细菌叶枯病（BLB）的防护活性分别为49.65％和49.42％，优于硫代二唑铜（44.28％和41.51％）和比美噻唑（38.89％）。和40.09％）。化合物33对BLS的保护活性与防御相关酶活性，叶绿素含量和光合作用活化的提高密切相关。这与防御反应和光合作用相关蛋白的表达上调相一致。