Synthesis, DFT calculation, DNA-binding, antimicrobial, cytotoxic and molecular docking studies on new complexes VO(II), Fe(III), Co(II), Ni(II) and Cu(II) of pyridine Schiff base ligand
Synthesis, DFT calculation, DNA-binding, antimicrobial, cytotoxic and molecular docking studies on new complexes VO(II), Fe(III), Co(II), Ni(II) and Cu(II) of pyridine Schiff base ligand
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DOI：
10.1088/2053-1591/ab95d6
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发表时间：
2020-06-01
影响因子：
2.3
通讯作者：
AlZamil, Noura O.
中科院分区：
文献类型：
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作者：
AlZamil, Noura O.
以2，6-二氨基吡啶和3-乙氧基水杨醛为原料，以1：2的摩尔比合成了一个新的H2 L配体（6，6 '-（吡啶-2，6-二基双（氮烷-1-基-1-亚基））双（甲烷-1-基-1-亚基）双（2-乙氧基苯酚），并通过元素分析和光谱手段对其进行了表征。通过配体与不同金属盐的反应，合成了五种新的配合物CuL、CoL、NiL、FeL和Vol，并通过元素分析、红外光谱、紫外-可见光谱、磁矩、摩尔电导和热重分析等手段对其结构进行了表征。从电导率数据可以推断，所有的配合物都是非电解质。FT-IR光谱表明，席夫碱配体与金属离子的配位方式为ONNO供体中心、吡啶环上的氮原子、甲亚胺基上的氮原子和两个酚羟基上的两个氧原子。电子光谱和磁化率的结果证实了FeL配合物的八面体构型，CoL、CuL和VOL的四方锥构型，NiL的四方平面构型。在DFT-B3 LYP-311 G** 水平上对H2 L配体及其配合物的电子结构进行了理论研究。FT-IR光谱证实吡啶氮参与了配位过程。TGA研究支持配合物CoL，CuL和FeL的配位球内的配位水分子的存在。对两种革兰氏阳性菌（B. subtitles和S. aureus）和2株革兰氏阴性（E.大肠杆菌和P. vulgaris）和两种真菌（白色念珠菌和烟曲霉）。结果表明，配合物的抗菌性能优于配体，其中VOL配合物表现出优异的抗菌效果。结果表明，配合物的抗菌和抗真菌能力依次为H_2L < NiL <CuL < CoL < FeL <Vol。这些研究证实，复合物通过具有一定亲和力的沟槽结合模式与CT-DNA结合（对于CuL、FeL、VOL、NiL和CoL，Kb分别为6.25 × 10（5）、5.50 × 10（5）、3.20 × 10（5）、2.50 × 10（5）和1.52 × 10（5））。此外，对肝癌细胞系（HEP-G2）的细胞毒作用进行了筛选。配体和配合物的IC_（50）值表明，化合物具有很好的细胞毒活性，其顺序为：CuL >FeL>VOL>NiL>CoL > H_2L。这些结果与CT-DNA与不同金属配合物的结合常数的结果一致。
A new H2L ligand (6, 6 '-(pyridine-2, 6-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)bis(2-ethoxyphenol) was obtained from the reaction of 2, 6- diamino pyridine and 3- ethoxy salicyaldehyde in 1:2 molar ratio and fully characterized using elemental analyses and spectroscopic tools. The reaction of a ligand with the different metal salts yields five new complexes CuL, CoL, NiL, FeL, and VOL. The new complexes were identified according to the results of elemental analyses, IR and UV-vis spectra, magnetic moment, molar conductance and thermal analyses (TGA). From the conductivity data, it is deduced that all complexes are non-electrolytes. FT-IR spectra displayed that the Schiff base ligand coordinated to the metal ions in a manner with ONNO donor sites, the nitrogen atom of the pyridine ring, the nitrogen of one azomethine group and two oxygen atoms of the two phenolic OH groups. The results of electronic spectra and magnetic susceptibility confirmed octahedral geometry of FeL complex and square pyramidal geometry for CoL, CuL and VOL and square planar for NiL. The electronic structure of H2L ligand and its complexes were investigated theoretically at the DFT-B3LYP-311 G** level of the theory. FT-IR spectra established the involvement of pyridine nitrogen in the coordination process. The presence of coordinated water molecules inside the coordination sphere of the complexes CoL, CuL and FeL are supported by TGA studies. The antimicrobial activities of the ligand and its complexes were determined against two Gram-positive bacteria (B. subtitles and S. aureus) and two Gram-negative (E. coli and P. vulgaris) and two fungus (Candida albicans and Aspergilla's fumigates). The results showed that the complexes behaved as better antimicrobial agents than the ligand, VOL complex shows exceptional antimicrobial efficacy. The order of increasing the antibacterial and antifungal potency is H2L < NiL < CuL < CoL < FeL < VOL. The binding of the complexes with CT-DNA was followed using electronic absorption, viscosity and gel-electrophoresis measurements. These studies confirmed that the complexes bind to CT-DNA through a groove binding mode with certain affinities (Kb = 6.25 x 10(5), 5.50 x 10(5), 3.20 x 10(5), 2.50 x 10(5) and 1.52 x 10(5) for CuL, FeL, VOL, NiL, and CoL respectively). Moreover, cytotoxic effect against hepatocellular carcinoma cell line (HEP-G2) was screened. The IC50 values of the ligand and complexes suggest that the compounds possess very good cytotoxic activity and follow the order: CuL >FeL>VOL>NiL>CoL > H2L. These results strongly agree with results of binding constant of CT-DNA with different metal complexes.