DNA-binding and photoactivated enantiospecific cleavage of chiral polypyridyl ruthenium(II) complexes.
A series of enantiomeric polypyridyl ruthenium(II) complexes Delta- and Lambda-[Ru(bpy)2CNOIP](PF6)2 (Delta-1 and Lambda-1; BPY=2,2'-bipyridine, CNOIP=2-(2-chloro-5-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline), Delta- and Lambda-[Ru(bpy)2HPIP](PF6)2 (Delta-2 and Lambda-2; HPIP=2-(2-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline), Delta- and Lambda-[Ru(bpy)2DPPZ](PF6)2 (Delta-3 and Lambda-3; DPPZ=dipyrido[3,2:a-2',3':c]-phenazine), Delta- and Lambda-[Ru(bpy)2TAPTP](PF6)2 (Delta-4 and Lambda-4; TAPTP=4,5,9,18-tetraazaphenanthreno[9,10-b] triphenylene) have been synthesized. Binding of these chiral complexes to calf thymus DNA has been studied by spectroscopic methods, viscosity, and equilibrium dialysis. The experimental results indicated that all the enantiomers of these complexes bound to DNA through an intercalative mode, but the binding affinity of each chiral complex to DNA was different due to the different shape and planarity of the intercalative ligand. After binding to DNA, the luminescence property of complex 1 was distinctly different from complexes 2 to 4. Upon irradiation at 302 nm, complexes 2-4 were found to promote the cleavage of plasmid pBR 322 DNA from supercoiled form I to nicked form II, and obvious enantioselectively was observed on DNA cleavage for the enantiomers of complexes 2 and 4. The mechanisms for DNA cleavage by these enantiomeric complexes were also proposed.
Zhang
Qian-Ling
QL
Department of Chemistry and Biology, Normal College, Shenzhen University, Shenzhen 518060, PR China. qlzh98@yahoo.com.cn
Liu
Jian-Hong
JH
Liu
Jian-Zhong
JZ
Zhang
Pei-Xin
PX
Ren
Xiang-Zhong
XZ
Liu
Yi
Y
Huang
Yi
Y
Ji
Liang-Nian
LN
D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D008968:Molecular Conformation; D015394:Molecular Structure; D010777:Photochemistry; D017975:Ruthenium Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*
D017975:Ruthenium Compounds; D004247:DNA