Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin 300070, PR China.
J Inorg Biochem. 2012 Oct;115:78-86. doi: 10.1016/j.jinorgbio.2012.05.018. Epub 2012 Jun 7.
New oxamido-bridged copper(II) complexes, [Cu(2)(oxbp)(H(2)O)(2)(NCS)(2)] (1) and [Cu(2)(oxbp)(μ-DMSO)(2)(NCS)(2)][Cu(2)(oxbp)(DMSO)(2)(NCS)(2)] (2) (H(2)oxbp=N,N'-bis(2-(diethylamino)ethyl)oxalamide), were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, and electronic spectra. X-ray analysis revealed that complex 1 consists of neutral binuclear [Cu(2)(oxbp)(H(2)O)(2)(NCS)(2)] units which forms a two-dimensional network through intermolecular hydrogen bonds and complex 2 is constructed by neutral [Cu(2)(oxbp)(μ-DMSO)(2)(NCS)(2)] (2a) and [Cu(2)(oxbp)(DMSO)(2)(NCS)(2)] (2b) entities which alternately distribute to form a two-dimensional network by means of quasi μ-DMSO bridge and intermolecular hydrogen bonds. In both 1 and 2, bicopper centers are linked by the "trans-form" oxamido bridges with the distances of 5.272 Å for 1 and av. 5.296 Å for 2, respectively. The interaction of Cu(II) complexes with DNA was investigated by UV-visible, fluorescence emission spectrometry and agarose gel electrophoresis. The apparent binding constant (K(app)) values of 3.16×10(5) M(-1) for 1 and 4.9×10(5) M(-1) for 2 suggest moderate intercalative binding modes between the complexes and DNA. Complex 1 displayed efficient oxidative cleavage of supercoiled DNA, which might indicate that the underlying mechanism involves singlet oxygen (((1))O(2)) as reactive oxygen species. Complex 2 is characteristic of the involvement of a singlet oxygen-like entity and hydrogen peroxide in the cleavage process. In addition, our present work showed, by fluorescence spectrometry of BSA with complexes, both 1 and 2 bind to BSA with a medium affinity through a static mode which is tentatively assigned binding to Trp134 in BSA.
新的氧肟酸桥联铜（II）配合物[Cu(2)(oxbp)(H(2)O)(2)(NCS)(2)]（1）和[Cu(2)(oxbp)(μ-DMSO)(2)(NCS)(2)][Cu(2)(oxbp)(DMSO)(2)(NCS)(2)]（2）（H(2)oxbp=N,N'-双（2-（二乙氨基）乙基）氧酰胺），通过单晶 X 射线衍射、元素分析、IR 和电子光谱进行了合成和表征。X 射线分析表明，配合物 1 由中性双核[Cu(2)(oxbp)(H(2)O)(2)(NCS)(2)]单元组成，这些单元通过分子间氢键形成二维网络，而配合物 2 则由中性[Cu(2)(oxbp)(μ-DMSO)(2)(NCS)(2)]（2a）和[Cu(2)(oxbp)(DMSO)(2)(NCS)(2)]（2b）实体组成，这些实体通过准μ-DMSO 桥和分子间氢键交替分布形成二维网络。在 1 和 2 中，双铜中心通过“反式”氧肟酸桥连接，距离分别为 5.272 Å 和 av.5.296 Å。Cu(II)配合物与 DNA 的相互作用通过紫外可见、荧光发射光谱和琼脂糖凝胶电泳进行了研究。配合物 1 的表观结合常数（K(app)）值为 3.16×10(5) M(-1)，配合物 2 的 K(app)值为 4.9×10(5) M(-1)，表明配合物与 DNA 之间存在适度的嵌入结合模式。配合物 1 对超螺旋 DNA 具有有效的氧化断裂活性，这表明其潜在的机制涉及单线态氧（((1))O(2)）作为活性氧物质。配合物 2 的特征是涉及单线态氧样实体和过氧化氢在切割过程中。此外，通过复合物与 BSA 的荧光光谱研究，我们的工作表明，1 和 2 均通过静态模式与 BSA 中等亲和力结合，这种结合方式推测与 BSA 中的色氨酸 134 结合。
