title: Two novel copper complexes of 2,2'-bipyridine: evaluation of the DNA binding and cytotoxic activity.
abstract: Two novel copper-2,2'-bipyridine complexes [Cu(SAL)(2,2'-bipy)ClO4]2 (1) and [Cu(μ2-O)(2,2'-bipy)NO3]2 (2) (HSAL=salicylaldehyde) were synthesized and characterized by X-ray single-crystal diffraction, elemental analysis and IR spectra. The interactions of the complexes with salmon sperm DNA were investigated by viscosity analysis, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral (Kb=3.00×10(5)M(-1) (1), 3.49×10(5)M(-1)(2)), emission spectral ((Ksv) 3.33×10(4)M(-1) (1), 3.40×10(4)M(-1) (2)), and viscosity measurements reveal that 1 and 2 interact with DNA through intercalation. In fluorimetric studies, the enthalpy (ΔH>0) and entropy (ΔS>0) changes of the reactions between the Cu (II) complexes with DNA demonstrate hydrophobic interactions. In addition, CD study indicates the Cu (II) complexes cause a more B-like to a more A-like conformational change upon binding DNA. All the experimental results show that the interaction mode of the two complexes was greatly affected by the coordination environments of Cu (II) centers. Their in vitro cytotoxicity towards five selected tumor cell lines HepG-2, HeLa, NCI-H460, MCF-7 and HL-60 has been evaluated by MTT method, and 2 exhibits higher growth inhibition of the selected cell lines at concentration of 50 μM, this result is identical with their DNA binding ability order.
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China. baolifei@yahoo.com
authors.forename: Bao-Li
authors.initials: BL
authors.lastname: Fei
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.forename: Wu-Shuang
authors.initials: WS
authors.lastname: Xu
authors.forename: Yang-Guang
authors.initials: YG
authors.lastname: Li
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Long
authors.forename: Qing-Bo
authors.initials: QB
authors.lastname: Liu
authors.forename: Kui-Zhan
authors.initials: KZ
authors.lastname: Shao
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Su
authors.forename: Wei-Yin
authors.initials: WY
authors.lastname: Sun
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D009942:Organometallic Compounds; D015082:2,2'-Dipyridyl; D003300:Copper; D004247:DNA
keywords: Binuclear complex; Copper; Crystal structure; Cytotoxicity; DNA