Metal Complexes of a Novel Schiff Base Based on Penicillin: Characterization, Molecular Modeling, and Antibacterial Activity Study.
Metal Complexes of a Novel Schiff Base Based on Penicillin: Characterization, Molecular Modeling, and Antibacterial Activity Study.
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DOI：
10.1155/2017/6927675
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发表时间：
2017
影响因子：
3.8
通讯作者：
Mishra P
中科院分区：
文献类型：
--
作者：
Chaudhary NK;Mishra P
采用三水合阿莫西林与烟醛缩合反应制备了新型HL型希夫碱配体。通过元素分析、熔点、电导率、1H NMR、IR、UV-Vis光谱、ESR、SEM和质谱等物理和光谱技术对Co+2、Ni+2、Cu+2和Zn+2金属配合物进行了表征和研究。通过热分析技术（TGA/DTA）进一步分析了配合物的热稳定性和动力学性质。热数据显示了高的热稳定性和分解步骤的非自发性质。采用Coats-Redfern方法提取热力学参数来解释其动力学行为。摩尔电导值相对较低，表明其非电解性质。粉末XRD图谱除铜配合物（1c）以三斜晶系结晶外，其余均为非晶态。EPR研究强烈推荐1c为四面体。通过ArgusLab 4.0.1软件进行MM力场计算的结构优化，支持了相关复合物的几何形状。在两种不同浓度下，对大肠杆菌、寻常假单胞菌、肺炎克雷伯菌和金黄色葡萄球菌4种病原菌的体外抑菌活性进行了筛选，均表现出比母药和对照药更好的抑菌活性。
A novel Schiff base ligand of type HL was prepared by the condensation of amoxicillin trihydrate and nicotinaldehyde. The metal complexes of Co+2, Ni+2, Cu+2, and Zn+2 were characterized and investigated by physical and spectral techniques, namely, elemental analysis, melting point, conductivity, 1H NMR, IR, UV-Vis spectra, ESR, SEM, and mass spectrometry measurements. They were further analyzed by thermal technique (TGA/DTA) to gain better insight about the thermal stability and kinetic properties of the complexes. Thermal data revealed high thermal stability and nonspontaneous nature of the decomposition steps. The Coats-Redfern method was applied to extract thermodynamic parameters to explain the kinetic behavior. The molar conductance values were relatively low, showing their nonelectrolytic nature. The powder XRD pattern revealed amorphous nature except copper complex (1c) that crystallized in the triclinic crystal system. The EPR study strongly recommends the tetrahedral geometry of 1c. The structure optimization by MM force field calculation through ArgusLab 4.0.1 software program supports the concerned geometry of the complexes. The in vitro antibacterial activity of all the compounds, at their two different concentrations, was screened against four bacterial pathogens, namely, E. coli, P. vulgaris, K. pneumoniae, and S. aureus, and showed better activity compared to parent drug and control drug.