DNA-binding studies and antioxidant activities of two-, three- and four-coordinate silver(I) complexes containing bis(2-benzimidazolyl)aniline derivatives
DNA-binding studies and antioxidant activities of two-, three- and four-coordinate silver(I) complexes containing bis(2-benzimidazolyl)aniline derivatives
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DOI：
10.1039/c4nj00503a
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发表时间：
2014-07
影响因子：
3.3
通讯作者：
Huilu Wu;Yanhui Zhang;Chengyong Chen;Jiawen Zhang;Yuchen Bai;Furong Shi;Xiaoli Wang
中科院分区：
文献类型：
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作者：
Huilu Wu;Yanhui Zhang;Chengyong Chen;Jiawen Zhang;Yuchen Bai;Furong Shi;Xiaoli Wang
制备了双（苯并咪唑-2-基甲基）苯胺（bba）、双（n -甲基苯并咪唑-2-基甲基）苯胺（Mebba）和双（n -乙基苯并咪唑-2-基甲基）苯胺（Etbba）三个配体。这些设计的形状特异性配体与Ag(pic) （pic =苦酸盐）反应得到了三种新型配合物，即[Ag2(bba)2](pic)2·2DMF 1, [Ag(Mebba)2]（pic）·Et2O 2和[Ag(Etbba)(pic)] 3。通过元素分析、紫外可见光谱、红外光谱、核磁共振和x射线晶体学对配体和Ag(I)配合物进行了表征。1是具有2重旋转对称的双核金属环，其中两个同构象bba配体由两个线性配位的Ag(I)原子连接。2由一个Ag(I)离子和两个Mebba配体组装而成的中心对称单核孔管结构组成，形成扭曲的四面体几何形状。3的结构由一个Etbba配体、一个苦味酸阴离子和一个Ag(I)原子组成，Ag(I)周围的配位几何最适合描述为y形。为了探究其结构与生物学特性之间的关系，通过电子吸收、荧光和粘度测量等方法研究了其dna结合特性。实验结果表明，Ag(I)复合物以插层方式与DNA结合，其与DNA的结合亲和力为2 > 1 > 3数量级。此外，还研究了标题配合物的抗氧化活性。结果表明，这三种Ag(I)配合物具有很强的体外清除羟基和超氧自由基的潜力。
Three ligands bis(benzimidazol-2-ylmethyl)aniline (bba), bis(N-methylbenzimidazol-2-ylmethyl)aniline (Mebba), and bis(N-ethylbenzimidazol-2-ylmethyl)aniline (Etbba) have been prepared. Reaction of these shape-specific designed ligands with Ag(pic) (pic = picrate) afforded three novel complexes, namely, [Ag2(bba)2](pic)2·2DMF 1, [Ag(Mebba)2](pic)·Et2O 2 and [Ag(Etbba)(pic)] 3. The ligands and Ag(I) complexes were characterized by elemental analysis, UV-vis, IR, NMR and X-ray crystallography. 1 is a dinuclear metallacycle with 2-fold rotational symmetry in which two syn-conformational bba ligands are connected by two linearly coordinated Ag(I) atoms. 2 consists of a centrosymmetric uninuclear pore canal structure assembled from a Ag(I) ion and two Mebba ligands, resulting in a distorted tetrahedron geometry. The structure of 3 consists of a ligand of Etbba, one picrate anion, and one Ag(I) atom, and the coordination geometry around Ag(I) is best described as Y-shaped. In order to explore the relationship between the structure and biological properties, the DNA-binding properties have been investigated by electronic absorption, fluorescence, and viscosity measurements. The experimental results suggest that Ag(I) complexes bind to DNA in an intercalation mode, and their binding affinity for DNA follows the order 2 > 1 > 3. Moreover, antioxidant activities of the title complexes have been investigated. The result demonstrates that the three Ag(I) complexes have a strong potential to be applied as scavengers to eliminate hydroxyl and superoxide radicals in vitro.