Department of Chemistry, Faculty of Science, Razi University, Kermanshah, Iran.
DNA Cell Biol. 2011 Jul;30(7):507-15. doi: 10.1089/dna.2010.1151. Epub 2011 Feb 23.
Two cobalt (II) complexes containing a dipyrido[3,2-a:2',3'-c]phenazine (dppz) base with the general formulation [Co(dppz)(dmp)(2)]Cl(2), where dmp is 4,7-dimethyl-1,10-phenanthroline ligand (4,7-dmp) (1) and 2,9-dimethyl-1,10-phenanthroline ligand (2,9-dmp) (2) were synthesized and characterized. Binding interactions of these complexes with calf thymus DNA were investigated by emission, absorption, circular dichroism, and viscosity studies, and the effects of the positions of methyl substitutions in phenanthroline coligands were investigated. The DNA binding constants obtained from the absorption spectral titrations decrease in the order of 1 > 2, which is consistent with the trend in apparent emission enhancement of the complexes on binding to calf thymus DNA. These observations were supported by circular dichroism spectroscopy and viscosity measurements and reveal that DNA binding affinity of the complexes depends on the position of methyl groups on the phenanthroline ligands.
合成并表征了两种含有二吡啶并[3,2-a:2',3'-c]吩嗪（dppz）碱基的钴（II）配合物，其通式为[Co(dppz)(dmp)(2)]Cl(2)，其中 dmp 是 4,7-二甲基-1,10-菲咯啉配体（4,7-dmp）（1）和 2,9-二甲基-1,10-菲咯啉配体（2,9-dmp）（2）。通过荧光、吸收、圆二色性和粘度研究研究了这些配合物与小牛胸腺 DNA 的结合相互作用，并研究了菲咯啉辅助配体中甲基取代位置的影响。从吸收光谱滴定获得的 DNA 结合常数按 1>2 的顺序减小，这与配合物与小牛胸腺 DNA 结合时的明显发射增强趋势一致。这些观察结果得到了圆二色性光谱和粘度测量的支持，并表明配合物的 DNA 结合亲和力取决于菲咯啉配体上甲基的位置。
