Joseyphus R Selwin, Nair M Sivasankaran
Department of Chemistry, Manonmaniam Sundaranar University, Tirunelveli-627 012, India.
Mycobiology. 2008 Jun;36(2):93-8. doi: 10.4489/MYCO.2008.36.2.093. Epub 2008 Jun 30.
Two Schiff base ligands L1and L2 were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1: 1electrolytes. The IR data demonstrate the tetradentate binding of L1and tridentate binding of L2. The XRD data show that Zn(II) complexes with L1and L2 have the crystallite sizes of 53 and 61nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.
通过甘氨酰甘氨酸分别与咪唑 -2-甲醛和吲哚 -3-甲醛缩合得到了两种席夫碱配体L1和L2，并制备了它们与Zn(II)的配合物，通过微量分析、电导率测量、红外光谱（IR）、紫外可见光谱（UV-Vis.）、X射线衍射（XRD）和扫描电子显微镜（SEM）对其进行了表征。摩尔电导率测量表明，Zn(II)配合物为1:1电解质。红外光谱数据表明L1为四齿配位，L2为三齿配位。X射线衍射数据表明，与L1和L2形成的Zn(II)配合物的微晶尺寸分别为53和61nm。使用扫描电子显微镜研究了配合物的表面形态。通过纸片扩散法对所研究化合物针对金黄色葡萄球菌、大肠杆菌、肺炎克雷伯菌、普通变形杆菌和铜绿假单胞菌等细菌以及黑曲霉、匍枝根霉、黄曲霉、立枯丝核菌和白色念珠菌等真菌进行了体外生物筛选测试。席夫碱配体及其配合物抑制值的比较研究表明，配合物比游离配体表现出更高的抗菌活性。已证明锌离子对于生长抑制作用至关重要。抑制程度似乎强烈依赖于初始细胞密度和生长培养基。
