Oligonuclear polypyridylruthenium(ii) complexes incorporating flexible polar and non-polar bridges: synthesis, DNA-binding and cytotoxicity
作者:Yanyan Mulyana、Daniel K. Weber、Damian P. Buck、Cherie A. Motti、J. Grant Collins、F. Richard Keene
DOI:10.1039/c0dt01250e
日期:——
The paper reports the synthesis and characterisation of a series of flexible di-bidentate bridging ligands in which two 4-methyl-2,2′-bipyridine groups are linked at the 4′-position by polymethylene (bbn), linear polyether (bbOn) or linear alkylamine (bbNn) chains of varying length (n). The enantiomers (ΔΔ/ΛΛ) of the rac forms of the ruthenium(II) dinuclear complexes incorporating these ligands – i.e. [Ru(phen)2}2(μ-BL)]4+ (phen = 1,10-phenanthroline; BL = bbn, bbOn or bbNn) – have been isolated by reaction of Δ- or Λ-[Ru(phen)2(py)2]2+ (py = pyridine) with the respective bridging ligands. Mononuclear species - in which only one of the bidentate moieties of the bridging ligand is coordinated – have also been isolated, as well as trinuclear and tetranuclear species involving the bb7 bridge. Fluorescence displacement studies of the DNA-binding of the dinuclear complexes containing the bbOn and bbNn bridges generally revealed a lower affinity than their bbn analogues for an oligonucleotide containing a single bulge site; the mononuclear complexes showed a lower affinity - and the trinuclear and tetranuclear complexes a higher affinity – than the dinuclear species, revealing an interesting interplay of lipophilicity, electrostatics and size in the complex/nucleic acid interaction. Cytotoxicity studies of these complexes against a murine leukaemia cell line revealed that the presence of the polyether or polyamine links in the chain lowered the cytotoxicity compared with their polymethylene analogues, and that the bb7-bridged trinuclear and tetranuclear complexes showed considerably enhanced cytotoxicity compared with the dinuclear Rubb7 analogue.
该论文报道了一系列柔性二齿桥连配体的合成和表征,其中两个4-甲基-2,2'-联吡啶基团通过聚亚甲基(bbn)、线性聚醚(bbOn)在4'位连接或不同长度 (n) 的线性烷基胺 (bbNn) 链。包含这些配体的钌(II)双核配合物的外消旋形式的对映体 (ΔΔ/ΛΛ) – 即 [Ru(phen)2}2(μ-BL)]4+ (phen = 1,10-菲咯啉; BL = bbn、bbOn 或 bbNn) – 通过 Δ- 或 Λ-[Ru(phen)2(py)2]2+ (py = 吡啶) 与各自的桥接配体反应分离。单核物种(其中仅桥配体的二齿部分之一被配位)以及涉及 bb7 桥的三核和四核物种也已被分离出来。含有 bbOn 和 bbNn 桥的双核复合物的 DNA 结合的荧光置换研究通常表明,与含有单个凸出位点的寡核苷酸相比,它们的 bbn 类似物具有较低的亲和力;与双核物质相比,单核复合物表现出较低的亲和力,而三核和四核复合物则表现出更高的亲和力,揭示了复合物/核酸相互作用中亲脂性、静电和大小之间有趣的相互作用。这些复合物针对小鼠白血病细胞系的细胞毒性研究表明,与聚亚甲基类似物相比,链中聚醚或多胺连接的存在降低了细胞毒性,并且与双核 Rubb7 类似物。