芦荟大黄素金属配合物的抗菌活性研究

Study on antibacterial activity of aloe emodin metal complex

目的合成芦荟大黄素-锰(Ⅱ)、芦荟大黄素-铁(Ⅲ)、芦荟大黄素-钴(Ⅱ)配合物并对其进行表征,比较配体和配合物的抗菌活性。方法以芦荟大黄素为原料,在无水乙醇中通过搅拌、溶解合成芦荟大黄素-锰(Ⅱ)、芦荟大黄素-铁(Ⅲ)、芦荟大黄素-钴(Ⅱ)配合物,采用核磁共振氢谱法、配位滴定法、红外光谱法、热重-差热分析法、紫外光谱法对其结构进行表征,采用滤纸片测试法和二倍稀释法比较配体和配合物对大肠埃希菌、金黄色葡萄球菌、肺炎链球菌等3种细菌的抑制作用。结果配体及配合物对3种细菌均有不同程度的抑制作用,其中大多数配合物抗菌活性强于其配体。结论芦荟大黄素与金属离子配位产生了协同抗菌作用。

Objective Synthesize aloeemodin-manganese(Ⅱ), aloeemodin-iron(Ⅲ), and aloeemodin-cobalt(Ⅱ) complexes and characterize their structures, and then compare the antibacterial activity of ligands and complexes. Methods Aloeemodin was used as the raw material, and aloeemodin-manganese(Ⅱ), aloeemodin-iron(Ⅲ), and aloeemodin-cobalt(Ⅱ) complexes were synthesized by dissolving in absolute ethanolandstirring. Then, the nuclear magnetic resonance proton spectroscopy, coordination titration, infrared spectroscopy, thermogravimetric-differential thermal analysis, andultraviolet spectroscopy were used to characterize their structures. The filter paper test method and the double dilution method were used to compare the inhibitory effects of ligands and complexes on three bacteria, including E. coli, Staphylococcus aureus, and Streptococcus pneumoniae. Results The ligands and complexes had different degrees of inhibition on E. coli, Staphylococcus aureus, and Streptococcus pneumoniae, and most of complexes had stronger antibacterial activity than their ligands. Conclusion The coordination of aloeemodin and metal ions produced a synergistic antibacterial effect.