A series of metal complexes that combine the structure of phenanthroline and salen have been synthesized and characterized by electron paramagnetic resonance spectroscopy. The effects of the 2,9-bis(2-hydroxyphenyl)-1,10-phenanthroline compounds complexed with CuII, NiII, CoII or MnIII on the temperature-dependent helix-to-coil transition of DNA have been measured. The interaction with DNA is metal-dependent and the highest stabilization is observed with the Co complex. The DNA cleaving activities have been studied with plasmid DNA and/or with a 32P-labelled duplex oligonucleotide depending on the redox properties of the complexes. The Cu complex is inactive whereas the Co chelate efficiently cleaves DNA in the presence of a reducing agent. Cleavage of DNA by the Mn complex can occur either in the presence of a reducing agent via the production of oxygen radicals (which are detected by EPR spectroscopy) or in the presence of an oxidant such as KHSO5. In both cases, the cleavage of nucleic acids is very efficient whereas no cleavage is observed with the Ni complex. The complexes of bis(hydroxyphenyl)phenanthroline with Mn and Co complement the tool-box of reagents available for cleavage of DNA.
一系列结合了
邻菲罗啉和salen结构的
金属配合物已通过电子顺磁共振光谱合成并表征。测量了2,9-双(2-羟
苯基)-1,10-
苯并
菲啉与CuII、NiII、CoII或MnIII形成的配合物对DNA温度依赖性螺旋-线圈转变的影响。与DNA的相互作用依赖于
金属类型,最高稳定化效果是由Co配合物实现的。根据配合物的
氧化还原性质,研究了它们对质粒DNA和/或32P标记的双链寡
核苷酸的DNA切割活性。Cu配合物无活性,而Co螯合物在还原剂存在下能有效切割DNA。Mn配合物通过产生
氧自由基(通过EPR光谱检测)或在与
氧化剂如KHSO5存在下均可切割DNA。无论是哪种情况,
核酸的切割都非常有效,而Ni配合物则没有观察到切割作用。Mn和Co的双(羟
苯基)
苯并罗啉配合物补充了DNA切割的试剂工具箱。