5-溴-2-羟基苯甲酰基取代芳醛腙的合成、表征及抑菌活性

以水杨酸甲酯为原料,先经溴化反应制得5-溴水杨酸甲酯,再经肼解反应制得5-溴-2-羟基苯甲酰肼,再与取代芳香醛缩合反应,制得7种5-溴-2-羟基苯甲酰基取代芳醛腙,其中3种为新化合物. 化合物的结构经IR、1H NMR、MS与元素分析测试技术表征确证. 抑菌测试表明,该类化合物对不同菌株的抑菌活性具有明显的选择性;在质量浓度为0.05%时,上述化合物对白色念珠菌、枯草芽孢杆菌的抑菌率高达100%,具有强抑菌活性,是一类极具潜力的抗真菌、抗革兰氏阳性菌的化合物. 5-溴-2-羟基苯基-3′,5′-二溴-2-羟基苯甲醛腙的抗菌活性接近广谱高效杀菌剂三氯生. 构效分析表明,化合物的抑菌活性与Ar环及其取代基性质有关,引入呋喃环、Ar环邻、对位引入-OH、-OCH_3等供电基容易导致化合物抑菌活性降低,Ar环的间位引入Cl、Br等卤素原子能够提高化合物的抑菌活性.

Synthesis, Characterization and Antibacterial Activities of 5-Bromo-2-hydroxybenzoyl Substituted Aromatic Aldehyde HydrazonesZHANG Ming, LU Jun-Rui , XIN Chun-Wei, LIU Fang, ZHOU Chang-Ming,

Seven 5-bromo-2-hydroxy benzoyl substituted aromatic aldehyde hydrazones were synthesized with methyl salicylate as raw materials via bromination, hydrazination and condensation reactions, respectively. Three novel compounds were reported. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, mass spectra and elemental analysis. The result of preliminary bioassay shows that the title compounds have obvious selective antibacterial activities to different classificatory bacterium at 0.05%(mass concentration), and have 100% inhibitory rate on Monilia albican and Bacillus subtilis. They will be a kind of potential antibacterial compounds against fungus and Gram-positive bacteria. 5-Bromo-2-hydroxyphenyl-3′,5′-dibromo-o-hydroxyphenyl substituted aromatic aldehyde hydrazone has the same antibacterial activity as triclosan. The analysis of structure activity shows that the antibacterial activities are related to the kind of Ar-ring and its substituent groups. The antibacterial activities are reduced by electron-donating groups, such as o-,p-OH, -OCH_3 of Ar-ring, however, they are enhanced by the m-substituted halogen groups of Ar-ring.