Tan Fangfang, Shi Baojun, Li Jian, Wu Wenjun, Zhang Jiwen
College of Science, Northwest Agriculture and Forestry University, Yangling 712100, China.
Institute of Pesticide Science, Northwest Agriculture and Forestry University, Yangling 712100, China.
Molecules. 2015 Nov 9;20(11):20118-30. doi: 10.3390/molecules201119680.
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无催化剂方法，从半胱氨酸和取代苯腈设计并合成了60种2-芳基-4,5-二氢噻唑，产率在64%至89%之间。主要通过核磁共振光谱数据分析确认了标题化合物的结构。抗菌活性测定表明，化合物(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')对青枯雷尔氏菌、猕猴桃溃疡病菌、枯草芽孢杆菌和蜡样芽孢杆菌表现出显著抑制作用，最低抑菌浓度(MICs)在3.91至31.24μg·mL(-1)之间。取代基的影响表明，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，否则吸电子基团和供电子基团都会消除抗菌活性。扫描电子显微镜(SEM)和脂肪酸暴露实验结果表明，这些抗菌化合物影响受试细菌中的脂肪酸合成。
