Elias Assayehegn, Abraha Tadese, Goitom G/Yohannes, S. Alemayehu, Tesfamariam Teklu
{"title":"Synthesis, Physicochemical, and Antimicrobial Activity of Copper and Zinc Complexes with N, O - Bidentate Schiff Base","authors":"Elias Assayehegn, Abraha Tadese, Goitom G/Yohannes, S. Alemayehu, Tesfamariam Teklu","doi":"10.4314/mejs.v15i1.3","DOIUrl":null,"url":null,"abstract":"This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc diffusion assay against Staphylococcus aureus (gram-positive), Escherichia coli (gram-negative), and Bacillus cereus (gram-negative) bacteria. For all microbial, the metal complexes recorded higher activities than the parent ligand; such increased activity of the complexes may be due to the chelation of the metal ion in the complexes, which enhances the lipophylic character favoring its permeation through the lipid layer of the cell membrane. Such metal complexes can therefore be explored in the future as an option for decreasing the pathogenic potential of infecting bacteria.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3000,"publicationDate":"2023-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Momona Ethiopian Journal of Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4314/mejs.v15i1.3","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc diffusion assay against Staphylococcus aureus (gram-positive), Escherichia coli (gram-negative), and Bacillus cereus (gram-negative) bacteria. For all microbial, the metal complexes recorded higher activities than the parent ligand; such increased activity of the complexes may be due to the chelation of the metal ion in the complexes, which enhances the lipophylic character favoring its permeation through the lipid layer of the cell membrane. Such metal complexes can therefore be explored in the future as an option for decreasing the pathogenic potential of infecting bacteria.
本文旨在制备新的高效抗菌配合物。通过水杨醛与对甲苯胺的缩合反应,成功地合成了席夫碱及其Cu、Zn配合物。采用摩尔电导率、紫外-可见(UV-Vis)、原子吸收光谱(AAS)和傅里叶变换红外(FTIR)技术对希夫碱及其配合物进行了表征。因此,这些表征不仅证实了合成的席夫碱作为N,O双齿配体(通过亚甲基氮和苯氧氧),并与Cu(II)和Zn(II)以1:2的金属配体比螯合,还揭示了配体π→π*/ N→π*的电子跃迁特征,以及配体-金属电荷转移和金属配合物的d-d转移特征。此外,Cu和Zn配合物的摩尔电导分别为54.12和51.41 S cm2 mol-1。此外,通过圆盘扩散试验对金黄色葡萄球菌(革兰氏阳性)、大肠杆菌(革兰氏阴性)和蜡样芽孢杆菌(革兰氏阴性)的抑菌活性进行了评价。对所有微生物而言,金属配合物的活性均高于母体配体;配合物活性的增加可能是由于配合物中的金属离子的螯合作用,这增强了其脂性,有利于其通过细胞膜的脂质层渗透。因此,未来可以探索这种金属配合物,作为降低感染细菌致病潜力的一种选择。