N-[1-(取代苯基)乙基]-2-羟基苯甲酰肼的合成、表征及抑菌活性

依据邻羟基二苯醚及芳香肼类化合物的抗菌特性, 以邻羟苯基为分子核心, 酰肼键为桥基, 设计合成了7种未见报道的N-(取代苯基)乙基-2-羟基苯甲酰肼类化合物. 以水杨酸甲酯为原料, 经肼解反应后与取代苯乙酮缩合, 再与硼氢化钠反应制得目标化合物, 化合物结构经IR, ¹H NMR和元素分析等证实. 抗菌活性测试结果表明, 该类化合物对不同菌株的抑菌活性具有明显的选择性和特异性. 当质量浓度为1×10^-4 g/mL时, 化合物3b和3e对大肠杆菌和白色念珠菌的抑菌率高达100%, 有极强的抑菌活性; 所有化合物对金黄色葡萄球菌的抑菌率均大于70%, 有一定的抑菌活性. 构效关系分析结果表明, 苯基中引入Cl或Br等卤原子能显著增强化合物的抑菌活性, 而引入-NO₂及-CH₃基团则会降低其抑菌活性.

Synthesis, Characterization and Antibacterial Activities of N-[1-(Substituted phenyl)ethyl]-2-hydroxybenzohydrazide

A series of novel N-1-(Substituted phenyl)ethyl]-2-hydroxybenzohydrazide derivatives was designed and synthesized by combining o-hydroxyl phenyl and substituted phenyl ethyl with the bridge of hydrazide bond, based on antibacterial characteristics of o-hydroxydiphenyl ethers and aromatic hydrazine compounds. Salicylic hydrazide was prepared by hydrazinolysis of methylsalicylate, and then condensated with the substituted acetophenones, finally reacted with NaBH4 to obtain the title compounds. The structures of the seven compounds were confirmed by 1H NMR, IR and elemental analysis. The results of preliminary bioassay showed that the title compounds had obvious specificity and selective antibacterial activities to different classificatory bacterium, and the inhibitory rates against Escherichia coli and Monilia albican of compounds 3b and 3e were as high as 100% at a mass concentration of 1×10-4 g/mL, which displayed excellent antibacterial activities, and the inhibitory rates against Staphlococcus aureus were over 70%, which exhibited a certain extent antibacterial activities. The analysis of structure-activity relationship showed that the antibacterial activities of the title compounds were enhanced by the halogen groups of the phenyl ring, but reduced by -NO2 and -CH3 of the phenyl ring.