title: Differences in structure, physiological stability, electrochemistry, cytotoxicity, DNA and protein binding properties between two Ru(III) complexes.
abstract: A novel Ru(III) complex, mer-[RuCl(3)(CH(3)CN)(dpq)] (1), has been synthesized and characterized by X-ray diffraction, where dpq=dipyrido[3,2-d:2',3'-f]quinoxaline. Its chemical and biological properties have been intensively compared with those of mer-[RuCl(3)(DMSO)(dpq)] (DMSO=dimethyl sulfoxide) (2). It has been found that the stability in buffered solutions and the reduction potential for the Ru(III)/Ru(II) couple can be modulated by changing the small molecule bonded to the Ru(III) center. Interactions of 1 with DNA have been investigated by DNA melting experiments, DNA competitive binding with EB (ethidium bromide), plasmid DNA cleavage experiments and viscosity measurements. The interaction of 1 and 2 with BSA (bovine serum albumin) has also been studied using fluorescent quenching method. The experimental results show that 1 exerts higher affinity towards DNA and BSA than 2 does. The cytotoxicity of 1 has been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method, and 2 shows slightly higher anticancer potency than 1 does against all the cell lines screened. Attempts are made to clarify the possible antitumor mechanisms of these two complexes by analyzing the experimental results presented.
authors.affiliation: MOE Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Caiping
authors.initials: C
authors.lastname: Tan
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zheng
authors.forename: Shuo
authors.initials: S
authors.lastname: Shi
authors.forename: Lanmei
authors.initials: L
authors.lastname: Chen
authors.forename: Liangnian
authors.initials: L
authors.lastname: Ji
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D004247:DNA / Q000378:metabolism*; D004563:Electrochemistry; D004996:Ethidium / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding; D012428:Ruthenium / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000378:metabolism*
chemical_list: D009942:Organometallic Compounds; C528076:mer-trichloro(acrylonitrile)(dipyrido(3,2-d-2',3'-f)quinoxaline)ruthenium(III); D012710:Serum Albumin, Bovine; D012428:Ruthenium; D004247:DNA; D004996:Ethidium