共查询到20条相似文献,搜索用时 15 毫秒
1.
Mei Wen-Jie Liu Jie Chao Hui Ji Liang-Nian Li An-Xing Liu Jian-Zhong 《Transition Metal Chemistry》2003,28(8):852-857
A novel porphyrin ruthenium mixed complex, [MPyTPP—Ru(pip)2Cl]+, has been prepared and characterized by elemental analyses, ES-MS, u.v.–vis. and electrochemistry. The DNA binding properties of this complex have been investigated by absorption spectroscopy, fluorescence spectroscopy and by viscosity measurements. The results indicate that the complex may bind with DNA in a groove-binding mode. Upon irradiation with u.v. light, this complex has been found to promote cleavage of plasmid pBR 322 DNA from the supercoiled form I to the open circular form II. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(21):3512-3521
A new ligand ITAP and its complex [Ru(dmb)2(ITAP)](ClO4)2 (ITAP = isatino [1,2-b]-1,4,8, 9-tetraazatriphenylene, dmb = 4,4′-dimethyl-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, Fast atom bombardment mass spectra, Electrospray mass spectra, and 1H NMR. Thermal denaturation and absorption titration experiments show the complex binds to calf thymus DNA (CT-DNA) with moderate affinities. Viscosity measurements and thermal denaturation indicate that the DNA-binding mode could be intercalative interaction. The Ru(II) complex in the presence of plasmid pBR322 DNA has been found to promote the cleavage of plasmid pBR322 DNA from the supercoiled Form I to the open circular Form II upon irradiation. Mechanisms for DNA cleavage by the complex were also investigated. 相似文献
3.
Photochemical and Photobiological Studies of a Furonaphthopyranone as a Benzo-spaced Psoralen Analog in Cell-free and Cellular DNA 总被引:1,自引:0,他引:1
Waldemar Adam Karsten Mielke Chantu R. Saha-Möller Marianne Möller Helga Stopper Rudolf Hutterer Friedemann W. Schneider Daniel Ballmaier Bernd Epe Francis F. Gasparro Xinsheng Chen Jacques Kagan 《Photochemistry and photobiology》1997,66(1):46-54
Abstract— Photobiological activities of the benzo-spaced psoralen analog furonaphthopyranone 3 have been investigated in cell-free and cellular DNA. The molecular geometry parameters of 3 suggest that it should not form interstrand crosslinks with DNA. With cell-free DNA no evidence for crosslinking but also not for monoadduct formation was obtained; rather, the unnatural furocoumarin 3 induces oxidative DNA modifications under near-UVA irradiation. The enzymatic assay of the photosensitized damage in cell-free PM2 DNA revealed the significant formation of lesions sensitive to formamidopyrimidine DNA glyco-sylase (Fpg protein). In the photooxidation of calf thymus DNA by the furonaphthopyranone 3, 0.29±0.02% 8-oxo-7,8-dihydroguanine (8-oxoGua) was observed. With 2'-deoxyguanosine (dGuo), the guanidine-releasing photooxidation products oxazolone and oxoimidazolidine were formed predominately, while 8-oxodGuo and 4-HO-8-oxodGuo were obtained in minor amounts. The lack of a significant D2 O effect in the photooxidation of DNA and dGuo reveals that singlet oxygen (type II process) plays a minor role; control experiments with tert -butanol and mannitol confirm the absence of hydroxyl radicals as oxidizing species. The furonaphthopyranone 3 (Ered = -1.93±0.03V) should act in its singlet-excited state as electron acceptor for the photooxidation of dGuo (δGET ca – kcal/mol), which corroborates photoinduced electron transfer (type I) as a major DNA-oxidizing mechanism. A comet assay in Chinese hamster ovary (CHO) AS52 cells demonstrated that the psoralen analog 3 damages cellular DNA upon near-UVA irradiation; however, no photosensitized mutagenicity was observed in CHO AS52 cell cultures 相似文献
4.
Jean-Luc Ravanat Jean Cadet Koiti Araki Henrique E. Toma Marisa H. G. Medeiros Paolo Di Mascio 《Photochemistry and photobiology》1998,68(5):698-702
The tetraruthenated porphyrin, u.-[/wes0-5,1O,15,2O-tet-ra(pyridyl)porphyrin]tetrakis[ftis-(bipyridine)chloride ruthenium(II)] (TRP) is a supramolecular cationic species. The aim of the present investigation was to evaluate the photodynamic properties of TRP and Zn-TRP to damage DNA with emphasis on the mechanistic aspects. The ability for tetraruthenated porphyrin derivatives to induce photosensitization reactions has been determined using 2′-deoxyguanosine as a DNA model compound. The main photooxidation products of the targeted nucleoside were identified and classified according to their mechanisms of formation, involving either a radical pathway (type I) or a singlet oxygen-mediated mechanism (type II). Quantification of the different oxidation products provides a means to evaluate the relative contribution of type I and type II pathways associated with the oxidative photosensitization of 2′-deoxyguanosine by tetraruthenated porphyrin derivatives. Results indicate that x02 plays a major role in the mechanism of photooxidation mediated by these porphyrin derivatives. In addition an increase of the photosensitizing effect in the presence of zinc is observed. For each sensitizer, the ratio between type II and type I photoproducts has been calculated and compared to that of other known dyes such as methylene blue and riboflavin. 相似文献
5.
P. Nagababu J. Naveena lavanya latha M. Rajesh S. Satyanarayana 《Journal of the Iranian Chemical Society》2009,6(1):145-152
The complex of cobalt(III) ethylenediamine was synthesized, isolated and characterized by UV-Vis, IR, and 1H NMR spectral methods. The binding of the complex with calf thymus DNA was investigated by absorption and emission spectroscopy, viscosity measurements, DNA melting and DNA photocleavage. The spectroscopic studies together with the viscosity measurements and DNA melting studies indicated that the complex binds to calf thymus DNA in a nonintercalative mode. This complex is found to promote photocleavage of the DNA plasmid pBR322 and shows a cytotoxic effect against CHO cells. 相似文献
6.
Induction of 8-Oxo-7,8-Dihydro-2'-Deoxyguanosine by Ultraviolet Radiation in Calf Thymus DNA and HeLa Cells 总被引:1,自引:0,他引:1
Xueshu Zhang Barry S. Rosenstein Yan Wang Mark Lebwohl David M. Mitchell Huachen Wei 《Photochemistry and photobiology》1997,65(1):119-124
Abstract— The levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) in purified calf thymus DNA and HeLa cells were measured following exposure to either UVC, UVB or UVA wavelengths. This DNA damage was quantitated using HPLC coupled with an electrochemical detector. The 8-oxodGuo was induced in purified DNA in a linear dose-dependent fashion by each portion of the UV spectrum at yields of 100, 0.46 and 0.16 8-oxodGuo per 105 2'-deoxyguanosine (dGuo) per kJ/m2 for UVC, UVB and UVA, respectively. However, the amount of 8-oxodGuo in HeLa cells irradiated with these UV sources decreased to approximately 2.0, 0.013 and 0.0034 8-oxodGuo per 105 dGuo per kJ/m2 , respectively. In contrast, the levels of cyclobutyl pyrimidine dimers were similar in both irradiated DNA and cells. Therefore, 8-oxodGuo is induced in cells exposed to wavelengths throughout the UV spectrum although it appears that protective precesses exist within cells that reduce the UV-induced formation of this oxidative DNA damage. Cell survival was also measured and the number of dimers or 8-oxodGuo per genome per lethal event determined. These calculations are consistent with the conclusion that dimers play a major role in cell lethality for UVC- or UVB-irradiated cells but only a minor role in cells exposed to UVA wavelengths. In addition, it was found that the relative yield of 8-oxodGuo to dimers increased nearly 1000-fold in both UVA-irra-diated cells and DNA compared with cells subjected to either UVC or UVB. These results are supportive of the hypothesis that 8-oxodGuo, and possible other forms of oxidative damage, play an important role in the induction of biological effects caused by wavelengths in the UVA portion of the solar spectrum. 相似文献
7.
Yun‐Jun Liu Hui Chao Jun‐Hua Yao Hong Li Yi‐Xian Yuan Liang‐Nian Ji 《Helvetica chimica acta》2004,87(12):3119-3130
A novel ligand 3‐(1H‐imidazo[4,5‐f][1,10]phenanthrolin‐2‐yl)‐4H‐1‐benzopyran‐4‐one (ipbp) and its ruthenium(II) complexes [Ru(bpy)2(ipbp)]2+ ( 1 ) and [Ru(ipbp)(phen)2]2+ ( 2 ) (bpy=2,2′‐bipyridine, phen=1,10‐phenanthroline) were synthesized and characterized by elemental analysis and mass, 1H‐NMR, and electronic‐absorption spectroscopy. The electrochemical behavior of the complexes was studied by cyclic voltammetry. The DNA‐binding behavior of the complexes was investigated by spectroscopic methods and viscosity measurements. The results indicate that complexes 1 and 2 bind with calf‐thymus DNA in an intercalative mode. In addition, 1 and 2 promote cleavage of plasmid pBR 322 DNA from the supercoil form I to the open circular form II upon irradiation. 相似文献
8.
表柔比星-铜体系与DNA作用的光谱和电化学法研究 总被引:1,自引:0,他引:1
表柔比星是临床上广泛用于治疗增殖很快的肿瘤. 应用紫外、荧光、黏度、循环伏安等方法研究了表柔比星及表柔比星-Cu2+体系与DNA的作用. 结果发现: 在pH=7.4时, 表柔比星可与Cu2+形成稳定体系. 加入DNA后表柔比星-Cu2+体系的紫外吸收明显降低; Scatchard图表明表柔比星-Cu2+体系对溴化乙锭(EB)与DNA的结合为竞争性抑制; 同时此体系可使DNA-EB体系荧光偏振度增大; 使DNA的热变性温度(tm)上升; 黏度增大; 循环伏安法表明DNA的加入使得表柔比星及表柔比星-Cu2+体系的式量电位正移; 凝胶电泳表明表柔比星-Cu2+体系对pBR322 DNA有非常好的水解切割活性. 综合以上结果得出: 表柔比星及表柔比星-Cu2+体系与DNA之间均为嵌插作用; 表柔比星-Cu2+体系具有更好的水解切割活性. 这些结果可为合理改善药效、降低抗癌药物毒性和设计新药提供依据. 相似文献
9.
The binding of the ruthenium(II) complexes [Ru(bpy)2(ITAP)](ClO4)2 (bpy = 2,2’-bipyridine) and [Ru(phen)2(ITAP)](ClO4)2 (phen = 1,10-phenanthroline, ITAP = isatino[1,2-b]-1,4,8,9-tetraazatriphenylene) to calf thymus DNA (CT-DNA) have been investigated
with UV–visible and emission spectroscopy, viscosity measurements, thermal denaturation, and photoactivated cleavage. The
experimental results indicate that the two complexes bind to CT-DNA through an intercalative mode. The two Ru(II) complexes
in the presence of plasmid pBR322 DNA have been found to give rise to nicking of DNA upon irradiation. 相似文献
10.
Zhang Qian-Ling Xu Hong Li Hong Liu Jie Liu Jian-Zhong Ji Liang-Nian Liu Jin-Gang 《Transition Metal Chemistry》2002,27(2):149-154
Two novel complex ions [Co(bpy)2IP]3+ and [Co(bpy)2PIP]3+, have been prepared and characterized by EA, mass spectra, u.v.–vis., and cyclic voltammetry. The binding behavior of both complexes to calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods, cyclic voltammetry, and viscosity measurements. The results suggest that both complexes bind to DNA by intercalation. Both promote cleavage of plasmid pBR 322 DNA from the supercoiled Form I to the open circular Form II upon irradiation. Mechanisms for photocleavage are proposed. 相似文献
11.
12.
The photoinduced DNA damage by the berberine derivative coralyne is presented. The irradiation of coralyne in the presence of plasmid DNA namely, pBR322, leads to remarkably fast DNA damage by single-strand cleavage, as determined by agarose-gel electrophoresis. Even upon exposure to sunlight, almost all of the supercoiled plasmid is converted to the open circular form in less than a minute [c(pBR322) = 3.5 x 10(-9) M; c(coralyne) = 4.3 x 10(-5) M]. The efficiency of the DNA strand cleavage is not decreased in the presence of radical-trapping reagents such as tert-butanol or DMSO. Moreover, the extent of the DNA damage is the same under aerobic conditions and at reduced oxygen concentration. Thus, the formation of reactive intermediates such as hydroxyl radicals or singlet oxygen is excluded. These results show that the exposure of coralyne and derivatives thereof to light, even with moderate light intensity, needs to be avoided during experiments in which their biological activity is assessed by plasmid unwinding assays. 相似文献
13.
Yun-Jun Liu Na Wang Wen-Jie Mei Fei Chen Li-Xin He Liu-Qing Jian Rui-Jie Wang Fu-Hai Wu 《Transition Metal Chemistry》2007,32(3):332-337
A novel ruthenium(II) polypyridyl complex [Ru(phen)2{ipbd)](ClO4)2 (ipbd = 3-(1H-Imidazo[4,5-f][1,10]phenanthrolin-2-yl)-1-benzodioxane, phen = 1,10-phenanthroline} has been synthesized and characterized
by elemental analysis, ES-MS and 1H-NMR spectra. The interaction of the complex with calf thymus DNA (CT-DNA) was investigated by absorption titration, fluorescence
spectra, thermal denaturation, viscosity measurements, circular dichroism and photoinduced cleavage. The results suggest that
the complex intercalates into the CT-DNA base pairs. Upon irradiation, this novel Ru(II) complex can cleave the plasmid pBR
322 DNA from the supercoiled form I to the open circular form II. 相似文献
14.
15.
Li‐Feng Tan Fang Wang Hui Chao Sheng Zhang Jun‐Jie Fei Liang‐Nian Ji 《Helvetica chimica acta》2008,91(7):1251-1260
A novel polypyridine ligand, dipyrido[3,2‐a:2′,3′‐c]phenazine‐11‐carboxylic acid methyl ester (=dppz‐11‐CO2Me), and its ruthenium(II) complex, [Ru(bpy)2(dppz‐11‐CO2Me)]2+ ( 1 ), were synthesized and characterized. The binding properties of this complex to calf‐thymus DNA (CT‐DNA) were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that the complex binds to DNA in an intercalative mode and serves as a molecular ‘light switch’ for DNA. When irradiated at 365 nm, the complex 1 promoted the photocleavage of plasmid pBR‐322 DNA. 相似文献
16.
三齿多吡啶钴(Ⅲ)、钌(Ⅱ)配合物的合成、表征及与DNA的相互作用 总被引:2,自引:0,他引:2
杨浩 《高等学校化学学报》2007,28(5):872-876
合成了两种新型三齿多吡啶钴(Ⅲ) [Co(PhTPY)(H2Bzimpy)]3+(A)和钌(Ⅱ) [Ru(PhTPY)(Bzimpy)](B)混配配合物, 用元素分析和1H NMR等对其结构进行了表征, 测定了配合物B的晶体结构. 用电子吸收光谱和荧光光谱等方法研究了配合物与小牛胸腺DNA的相互作用以及配合物对pBR322DNA的断裂作用. 结果表明, 两种配合物均是通过静电作用与DNA结合的. 凝胶电泳实验结果表明, 配合物A经波长310 nm光辐射15 min, 配合物B经450 nm光辐射4 min, 可使超螺旋pBR322DNA断裂为开环缺口型和线型DNA. 相似文献
17.
Chen GJ Qiao X Tian JL Xu JY Gu W Liu X Yan SP 《Dalton transactions (Cambridge, England : 2003)》2010,39(44):10637-10643
Two Eu(III) complexes, [Eu(acac)(3)(dpq)] (1) and [Eu(acac)(3)(dppz)] CH(3)OH (2) {viz. acetylacetonate (acac), dipyrido[3,2-d:20,30-f]quinoxaline (dpq), dipyrido[3,2-a:20,30-c] phenazine (dppz)}, have been synthesized and their DNA binding, photo-induced DNA cleavage activity and cell cytotoxicity are studied. The complexes display significant binding propensity to the calf thymus DNA in the order: 2(dppz) >1(dpq). Cleavage experiments using pBR322 supercoiled DNA suggest major groove binding for 2 and minor groove binding for 1. The mechanistic aspects on natural light (natural light in room during the day) and UV-A (365 nm) irradiation are via a mechanistic pathway involving formation of singlet oxygen and hydroxyl radical as the reactive species. The photo-induced DNA cleavage activity of 2 is also stronger than 1. The cytotoxicity of 1 and 2 against HeLa (cervical) cancer cells show that the IC(50) value of 19.11 ± 3.56 μM and 17.95 ± 5.47 μM, respectively. 相似文献
18.
5-Azido-8-alkoxy psoralens were synthesized. Laser flash photolysis (LFP: XeF, 351 nm, 55 mJ, 17 ns) of the azides in acetonitrile or benzene solution produces the triplet nitrene and a small amount of ketenimine. Laser flash photolysis of the azides in methanol or aqueous solution cleanly produces the triplet nitrene. In aqueous solution containing highly polymerized calf thymus DNA, LFP produces a mixture of triplet nitrene and ketenimine corresponding to photolysis of free and bound psoralen, respectively. The two transients decay slowly but at different rates. Assignment of the transient spectra were secured by matrix EPR and UV-visible spectroscopy. The triplet nitrene lifetime is the same in buffer and in the presence and absence of calf thymus DNA. The results explain why psoralen azides are unable to efficiently nick plasmid DNA pBR322 upon UV activation. 相似文献
19.
《应用有机金属化学》2017,31(8)
On treatment of copper(II) acetate with aryl hydrazone ligands, four new solid derivatives of copper(II) were produced in appreciable yields. Various characterization techniques including infrared, UV–visible, NMR, electron paramagnetic resonance and mass spectroscopies, elemental analysis, scanning electron microscopy, powder X‐ray diffraction and thermogravimetric analysis revealed a tetra‐coordination in all the mononuclear crystalline complexes with high thermal stability. Further, significant interaction of these novel complexes with calf thymus DNA via intercalative mode of binding was revealed by electronic absorption spectroscopy. The chemical nuclease activity of the complexes on pBR322 DNA was investigated in the presence and absence of oxidizing agent (H2O2). A potent nuclease activity was observed only in the presence of H2O2. Further, antibacterial and antifungal studies of the new ligands and complexes revealed that the latter possessed comparatively better activity. 相似文献
20.
Two new Schiff base-hydrazones bearing furan ring, (Z)-4-butoxy-N′-(furan-2-ylmethylene)benzohydrazide (IV) and (Z)-N′-(furan-2-ylmethylene)-4-(hexyloxy)benzohydrazide (V), as well as their Cu(II), Ni(II), and Zn(II) complexes have been synthesised and characterised. The DNA-binding and DNA-cleavage activities of both aroylhydrazone ligands and their transition metal complexes were examined using UV-VIS titration and agarose gel electrophoresis in the presence of an oxidative agent (H2O2). The results indicate that the copper complexes bind significantly to calf thymus DNA and effectively cleave pBR322 DNA whereas the nickel and zinc complexes interact slightly with DNA. 相似文献