title: DNA-binding and photocleavage studies of cobalt(III) polypyridyl complexes:.
abstract: Two complexes of [Co(phen)2IP]3+ (IP=imidazo[4,5-f][l,10]phenanthroline) and [Co(phen)2PIP]3+ (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline) have been synthesized and characterized by UV/VIS, IR, EA and mass spectra. The binding of the two complexes with calf thymus DNA has been investigated by absorption spectroscopy, cyclic voltammetry, viscosity measurements and DNA cleavage assay. The spectroscopic studies together with cyclic voltammetry and viscosity experiments support that both of the complexes bind to CT DNA by intercalation via IP or PIP into the base pairs of DNA. [Co(phen)2PIP]3+ binds more avidly to CT DNA than [Co(phen)2IP]3+, which is consistent with the extended planar and pi system of PIP. Noticeably, the two complexes have been found to be efficient photosensitisers for strand scissions in plasmid DNA.
authors.affiliation: Department of Chemistry, Zhongshan University, Guangzhou, PR China.
authors.forename: Q L
authors.initials: QL
authors.lastname: Zhang
authors.forename: J G
authors.initials: JG
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Chao
authors.forename: G Q
authors.initials: GQ
authors.lastname: Xue
authors.forename: L N
authors.initials: LN
authors.lastname: Ji
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004563:Electrochemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010618:Phenanthrolines / Q000138:chemical synthesis / Q000737:chemistry*; D010782:Photolysis; D013057:Spectrum Analysis
chemical_list: D009942:Organometallic Compounds; D010618:Phenanthrolines; D003035:Cobalt; D004247:DNA