稀土元素Eu络合物的合成及其抑菌性能

利用稀土元素Eu,以α-萘甲酸、β-萘甲酸、α-萘乙酸、β-萘乙酸作为络合物的第1配体,以1,10-邻菲口罗啉作为络合物的第2配体,合成了4种稀土络合物:Eu(α-NMA)3phen.H2O,Eu(α-NAA)3phen,Eu(β-NMA)3phen.H2O,Eu(β-NAA)3phen.成品为固体白色干燥粉末,热稳定性较好.通过滤纸条扩散法对所合成稀土络合物进行了抑菌性能测定,发现稀土络合物较单纯的稀土离子及配体对不同菌株均表现较强的抑制作用,具广谱抗菌性能;采用滤纸片扩散法,对所合成的稀土络合物以及相应配体的抑菌能力进行测定并比较,Eu(α-NMA)3phen.H2O稀土络合物的最小抑菌质量浓度(MIC)和最小杀菌质量浓度(MBC)分别是:MIC12为43.5μg/mL,MIB12为87μg/mL.根据稀土元素在紫外激发下发荧光的原理,通过荧光倒置显微镜观察,对稀土络合物的菌体作用位点进行了初步的定位;利用电子扫描显微镜观察了络合物对菌体形态的影响,结果表明稀土络合物对菌体生长的抑制,可能是先破坏菌体的表面结构,包括细胞膜和细胞壁,进而进入细胞内部,影响细菌细胞的生命活动.

Composition and Antibacterial Activity of Rare Earth Eu Complex

A series of complex such as Eu(α-NMA)3phen·H2O were synthesized using the rare earth Eu,the first ligand α-naphthoic acid,β-naphthoic acid,α-naphthaleneacetic acid,β-naphthalene acetic acid and the second ligand 1,10-phenanthroline.The 4 kinds of rare earth complexes were dry white powder,and exhibited good thermal stability.The antibacterial spectrum of the rare earth complexes were detected by the filter paper diffusion method,and the results showed that the antibacterial activity of them to different types of strains was stronger than the pure rare earth ions and the ligands,and with broad-spectrum anti-bacterial properties;At the same time,the antibacterial capacity of the rare earth complexes and its ligands were determined by the filter paper diffusion method.And their MIC12 is 43.5 μg/mL,MIB12 is 87 μg/mL.According to the principle that the rare earth elements could send out fluorescence under the UV excitation,a preliminary positioning to the role of cell position was observed by using fluorescence inverted microscope.The rare earth ions,phen and the complexes could damage the shape of the cell by observing with SEM and the rare earth ions and the complexes could also absorb on the cell surface while the phen could not,which was accordance with the result of the fluorescence inverted microscope.The above results indicated that the rare earth may damage the cell surface or the membrane or enzymes and so on.