Design and Synthesis of New 2-Aryl-4,5-Dihydro-thiazole Analogues: In Vitro Antibacterial Activities and Preliminary Mechanism of Action
作者:Fangfang Tan、Baojun Shi、Jian Li、Wenjun Wu、Jiwen Zhang
DOI:10.3390/molecules201119680
日期:——
Sixty 2-aryl-4,5-dihydrothiazoles were designed and synthesized in yields ranging from 64% to 89% from cysteine and substituted-benzonitriles via a novel metal- and catalyst-free method. The structures of the title compounds were confirmed mainly by NMR spectral data analysis. Antibacterial activity assays showed that the compounds (S)-2-(2′-hydroxyphenyl)-4-hydroxy-methyl- 4,5-dihydrothiazole (7h) and (R)-2-(2′-hydroxyphenyl)-4-hydroxymethyl-4,5-dihydro-thiazole (7h′) exhibited significant inhibition against Ralstonia solanacearum, Pseudomonas syringae pv. actinidiae, Bacillus subtilis and Bacillus cereus, with minimum inhibitory concentrations (MICs) ranging from 3.91 to 31.24 μg·mL−1. The effect of substituents showed that not only electron-withdrawing groups, but also electron-donating groups could abolish the antibacterial activities unless a 2′-hydroxy group was introduced on the 2-aryl substituent of the 4,5-dihydrothiazole analogues. The results of scanning electron microscope (SEM) and fatty acid exposure experiments indicated that these antibacterial compounds influence fatty acid synthesis in the tested bacteria.
通过一种新型的无金属和催化剂方法,设计并合成了 60 个 2-芳基-4,5-二氢噻唑类化合物,其中半胱氨酸和取代苯腈类化合物的产率为 64% 至 89%。标题化合物的结构主要通过核磁共振光谱数据分析得到了证实。抗菌活性测定结果表明,(S)-2-(2′-羟基苯基)-4-羟甲基-4,5-二氢噻唑(7h)和(R)-2-(2′-羟基苯基)-4-羟甲基-4,5-二氢噻唑(7h′)化合物对茄属拉氏菌(Ralstonia solanacearum)、丁香假单胞菌(Pseudomonas syringae pv.最低抑菌浓度为 3.91 μg-mL-1 至 31.24 μg-mL-1。取代基的影响表明,不仅取电子基团会削弱抗菌活性,而且供电子基团也会削弱抗菌活性,除非在 4,5-二氢噻唑类似物的 2-芳基取代基上引入 2′-羟基。扫描电子显微镜(SEM)和脂肪酸暴露实验的结果表明,这些抗菌化合物会影响受试细菌的脂肪酸合成。