RESUMO
Ruthenium(II) complexes containing phenazine ring have attracted attention to design as 'molecular light switches'. In this study, we synthesized two ruthenium complexes containing phenazine ring and studied their abilities to function as DNA intercalators, DNA 'light switches', DNA topo I inhibitors, DNA photocleavers and potential antitumor reagents. [Ru(bpy)2(mbipz)](PF6)2 (1) (bpy = 2,2'-bipyridine, mbipz = 2-(4'-methyl-bipyridine-4-yl)-1H-imidazo[4,5-b]phenazine) exhibited off-on type DNA 'light swtich' behavior. DNA binding modes of the two complexes were determined as intercalation by using UV-vis spectra, emission spectra, viscosity and molecular docking experiments. DNA photocleavage experimental results showed that the two ruthenium complexes effectively cleave plasmid DNA by producing singlet oxygen. Furthermore, they displayed good topo I inhibition activities. We further found that the two complexes displayed good antitumor activities against Eca-109 cells and A549 cells. The results demonstrated that introduction of phenazine ring will be helpful to design DNA 'light switch' based on ruthenium complex.Communicated by Ramaswamy H. Sarma.
Assuntos
Rutênio , DNA , DNA Topoisomerases Tipo I , Simulação de Acoplamento Molecular , FenazinasRESUMO
In this work, to make out the aryl-fusion effect on the photophysical properties of boron-pyridyl-imino-isoindoline dyes, compounds 1-5 were theoretically studied through analyses of their geometric and electronic structures, optical properties, transport abilities, and radiative (k r) and non-radiative decay rate (k nr) constants. The highest occupied molecular orbitals of aryl-fused compounds 2-5 are higher owing to the extended conjugation. Interestingly, aryl fusion in pyridyl increases the lowest unoccupied molecular orbital (LUMO) level, while isoindoline decreases the LUMO level; thus, 4 and 5 with aryl fusion both in pyridyl and isoindoline exhibit a similar LUMO to 1. Compounds 4 and 5 show relatively low ionization potentials and high electron affinities, suggesting a better ability to inject holes and electrons. Importantly, the aryl fusion is conducive to the decrease of k IC. The designed compound 5 exhibits a red-shifted emission maximum, low λh, and low k IC, which endow it with great potential for applications in organic electronics. Our investigation provides an in-depth understanding of the aryl-fusion effect on boron-pyridyl-imino-isoindoline dyes at molecular levels and demonstrates that it is achievable.
RESUMO
A new strategy for a G-quadruplex fluorescent probe based on a nitro-substituted ruthenium complex is described. G-quadruplex DNA can be distinguished from double- or single-strand DNA by the naked eye. This ability originates from variation of the degree of protection of the nitro group on the complex from water by G-quadruplex and other structure DNAs.
Assuntos
Complexos de Coordenação/química , DNA/análise , Corantes Fluorescentes/química , Quadruplex G , Nitrobenzenos/química , Colorimetria/métodos , DNA/genética , Humanos , Rutênio/químicaRESUMO
A new ligand mhcip (mhcip=2-(4-methyl-7-hydroxyl-8-coumarinyl)imidazo[4,5-f]-[1,10]phenanthroline) and its ruthenium complexes, [Ru(L)2mhcip](2+) (L=bpy (2,2'-bipyridine), phen (1,10-phenanthroline)), have been synthesized and characterized. The introduction of coumarin ring may play an important role in the strong fluorescence of the complexes. Intercalative binding mode between both complexes and CT-DNA was determined by UV-visible spectroscopy, fluorescence spectroscopy and viscosity measurements. The two complexes show efficient DNA photocleavage under irradiation at 365 nm. The cycling of light switch off and on has been achieved for both complexes through the introduction of Cu(2+) and EDTA in the absence or presence of DNA.
Assuntos
Cumarínicos/farmacologia , DNA/metabolismo , Substâncias Intercalantes/farmacologia , Compostos Organometálicos/farmacologia , Rutênio/farmacologia , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacologia , Animais , Bovinos , Cumarínicos/química , Clivagem do DNA/efeitos dos fármacos , Clivagem do DNA/efeitos da radiação , Substâncias Intercalantes/química , Luz , Compostos Organometálicos/química , Fenantrolinas/química , Fenantrolinas/farmacologia , Fotólise/efeitos dos fármacos , Fotólise/efeitos da radiação , Rutênio/químicaRESUMO
Two new ruthenium complexes with [Ru(L)(2)(qip)](2+) (L=bpy (2,2'- bipyridine), phen (1,10-phenanthroline); qip=2-(2-quinolinyl)imidazo[4,5-f][1,10]phenanthroline), have been synthesized and characterized by elemental analysis, ES-MS, (1)H NMR. The binding properties of two complexes towards CT-DNA were investigated by various optical methods and viscosity measurements. The experiment results suggested that both Ru(II) complexes can intercalate into DNA base pairs. Strong quenching in emission intensity of two Ru(II) complexes were observed upon addition of Ag(+) in the absence and presence of CT-DNA. Furthermore, the two complexes can promote cleavage of pBR322 DNA under irradiation at 365 nm, and complex 2 exhibits a stronger DNA-photocleavage efficiency than complex 1. The mechanism of DNA cleavage suggests that singlet oxygen ((1)O(2)) is likely to be the cleaving agent.
Assuntos
2,2'-Dipiridil/análogos & derivados , DNA/metabolismo , Substâncias Intercalantes/química , Substâncias Intercalantes/farmacologia , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Fenantrolinas/química , Fenantrolinas/farmacologia , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacologia , Animais , Bovinos , DNA/química , Clivagem do DNA/efeitos dos fármacos , Clivagem do DNA/efeitos da radiação , Imidazóis/química , Imidazóis/farmacologia , Medições Luminescentes , Processos Fotoquímicos , Prata/metabolismoRESUMO
A novel asymmetric ligand 2-(pyridine-2-yl)-1-H-imidazo[4,5-i]dibenzo[2,3-a:2',3'-c]phenazine (pidbp) and its ruthenium complexes [Ru(L)(2)(pidbp)](2+) (L=bpy (2, 2'- bipyridine), phen (1, 10 - phenanthroline)), have been synthesized and characterized by elemental analysis, ES-MS, (1)H NMR. Various methods support the conclusion that both Ru(II) complexes can intercalate into DNA base pairs. Complex [Ru(bpy)(2)(pidbp)](2+)4 exhibits its DNA "molecular light switch" properties. Furthermore, the two complexes are efficient DNA-photocleavers under irradiation at 365 nm, and complex 5 exhibits a stronger DNA-photocleavage efficiency than complex 4. The mechanism of DNA cleavage is an oxidative process by generating singlet oxygen.
Assuntos
Complexos de Coordenação/metabolismo , Clivagem do DNA/efeitos da radiação , DNA/metabolismo , Substâncias Intercalantes/metabolismo , Rutênio/metabolismo , Absorção/efeitos da radiação , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Elétrons , Eletroforese em Gel de Ágar , Etídio/química , Substâncias Intercalantes/química , Ligantes , Luz , Plasmídeos/metabolismo , Rutênio/química , Espectrometria de Fluorescência , Titulometria , Viscosidade/efeitos da radiaçãoRESUMO
In the title compound, C(18)H(14)N(4)O(2)·C(8)H(6)O(4), both types of mol-ecule lie on inversion centers. In the N,N'-bis-(pyridin-3-yl)terephthalamide mol-ecule, the pyridine ring forms a dihedral angle of 11.33â (9)° with the central benzene ring. In the crystal, N-Hâ¯O and O-Hâ¯N hydrogen bonds connect the components into a three-dimensional network.
RESUMO
Two novel Ru(II) complexes [Ru(bpy)(2)(pyip)](2+)1 and [Ru(phen)(2)(pyip)](2+)2 (bpy=2,2'-bipyridine; phen=1,10-phenanthroline; pyip=2-(pyridine-2-yl)imidazo-[4,5-f][1,10]-phenanthroline), have been synthesized and characterized by elemental analysis, ES-MS, (1)H NMR, UV-Vis. The DNA-binding behaviors of both complexes were studied by spectroscopic methods and viscosity measurements. The results indicate that the two complexes can bind to CT-DNA in an intercalative mode, and also show that these two Ru(II) complexes can promote the photocleavage of pBR322 DNA. In addition, In the presence of Co(2+), the emission of DNA-[Ru(L)(2)pyip](2+) can be quenched, which exhibited the DNA "light switch" properties.