Ruthenium(II) mixed-ligand complex containing 2-(4'-benzyloxy-phenyl)imidazo[4,5-f][1,10]phenanthroline: synthesis, DNA-binding and photocleavage studies.
A novel polypyridyl ligand 2-(4'-benzyloxyphenyl)imidazo[4,5-f][1,10]phenanthroline (BPIP) and its complex [Ru(bpy)2(BPIP)]2+ (1) (bpy=2,2'-bipyridine) and (2) [Ru(phen)2(BPIP)]2+) (phen=1,10-phenanthroline) have been synthesized and characterized by elemental analysis, electrospray mass spectra and 1H NMR. The DNA-binding properties of the two complexes were investigated by spectroscopic and viscosity measurements. The results suggest that both complexes bind to DNA via an intercalative mode. Both complexes can enantioselectively interact with calf thymus DNA (CT-DNA) in a way. The Lambda enantiomer of complex 1 is slightly predominant for binding to CT-DNA to the Delta enantiomer. Under irradiation at 365 nm, both complexes have also been found to promote the photocleavage of plasmid pBR 322 DNA. Inhibitors studies suggest that singlet oxygen ((1)O2) and hydroxyl radical (*OH) play a significant role in the cleavage mechanism for both complexes. Moreover, the DNA-binding and photocleavage properties of both complexes were compared with that of [Ru(bpy)2(BPIP)]2+ and [Ru(phen)2(BPIP)]2+. The experimental results indicate that methene group existence or not have a significant effect on the DNA-binding and cleavage mechanism of these complexes.
Tan
Li-Feng
LF
College of Chemistry, Xiangtan University, Xiangtan 411105, PR China. lfwyxh@yahoo.com.cn
Wang
Fang
F
Chao
Hui
H
Zhou
Yang-Fan
YF
Weng
Chao
C
D004247:DNA / Q000737:chemistry*; D053837:DNA Cleavage / Q000528:radiation effects; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods; D012428:Ruthenium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
D008024:Ligands; D009942:Organometallic Compounds; D010618:Phenanthrolines; D012428:Ruthenium; D004247:DNA