title: pH luminescence switch, DNA binding and photocleavage, and cytotoxicity of a dinuclear ruthenium complex.
abstract: The ground- and excited-state acid-base properties of [Ru2(bpy)4(H2bipt)]Cl4 1 {bpy = 2,2'-bipyridine, H2bipt = 2,5-bis[1,10]phenanthrolin[4,5-f]-imidazol-2-yl)thiophene} are investigated by emission and UV-visible absorption spectrophotometric pH titrations. The DNA binding properties of 1 are studied by means of DNA viscosity and optical spectroscopic techniques of UV-visible absorption and emission spectral titrations, steady-state emission quenching with ferrocyanide, ethidium bromide competitive binding, and DNA thermal denaturation as well as density functional theoretical calculations. The DNA photocleavage and singlet oxygen generation properties as well as in vitro anticancer activities against five cancer cell lines are studied as well. The results demonstrated that pH-induced luminescence switching, DNA binding, and anticancer properties of 1 are much improved with respect to those of the mononuclear analog [Ru(bpy)2(Htip)]Cl2 {Htip = 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline}.
authors: College of Chemistry, Beijing Key Laboratory of Energy Conversion and Storage Materials, Beijing Normal University, Beijing 100875, PR China.
authors: Xiao-Long
authors: XL
authors: Zhao
authors: Zhen-Sheng
authors: ZS
authors: Li
authors: Ze-Bao
authors: ZB
authors: Zheng
authors: An-Guo
authors: AG
authors: Zhang
authors: Ke-Zhi
authors: KZ
authors: Wang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D056831:Coordination Complexes / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061986:MCF-7 Cells; D009691:Nucleic Acid Denaturation; D010782:Photolysis; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*; D026082:Singlet Oxygen / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000970:Antineoplastic Agents; D056831:Coordination Complexes; D026082:Singlet Oxygen; D012428:Ruthenium; D004247:DNA