带有位阻基团的钌多吡啶配合物与DNA键合及其光断裂DNA性质的研究

合成了两个钌多吡啶配合物[Ru(bpy)₂DMNP](C1O₄)₂ (Ru1)和[Ru(bpy)₂BOPIP](C1O₄)₂ (Ru2), 应用元素分析、核磁共振对配合物结构进行了表征, 通过电子吸收光谱、荧光光谱、粘度实验以及凝胶电泳技术对配合物与DNA相互作用的性质进行了研究. 结果表明, 配合物与DNA分子之间以插入模式结合. 在紫外光照下, 两种配合物均能使质粒pBR322DNA断裂, 机理研究表明, 其光断裂DNA的活性氧化物种为单线态氧.     

手性钌(Ⅱ)配合物对DNA的立体选择性断裂

八面体钌(Ⅱ)多吡啶配合物与双螺旋DNA插入结合后具有较强的结合能力,并且含有一个具有氧化一还原活性的中心金属离子．它们对氧化剂相对比较稳定,但对光比较敏感,因此可利用光辐射使之产生单线态氧或羟基自由基等而使DNA裂解．此外,这些配合物具有左手∧-和右手△-两种构型,与同样具有手性的DNA作用时,存在着立体选择性结合．并且在对DNA的断裂反应中也存在一定的立体选择性,可作为不同构型DNA的结构探针．     

金属钌配合物的抗肿瘤活性及其作用机理

金属配合物在医药领域起着重要的作用,金属钌配合物在抗肿瘤活性研究方面取得了重要的进展.结合本组的研究工作,本文对金属钌配合物在抗肿瘤活性以及抗肿瘤作用机制方面的研究进展进行了综述.     

钌(II)多吡啶配合物光断裂DNA的实验研究

研究了一系列钌(II)多吡啶配合物对pBR 322 DNA 的光断裂作用, 并与光谱法和粘度法的研究结果进行了对比. 实验结果表明, 钌(II)多吡啶配合物光断裂DNA的能力不仅与配合物与DNA相互作用的结合模式和结合强度有关, 还与配合物自身的电子结构有关; 钌(II)多吡啶配合物对DNA的光断裂存在立体选择性; 其断裂机理是激发态的配合物与溶液中的氧分子发生能量转移生成单线态氧活性氧化物种, 将鸟嘌呤碱基氧化而导致DNA断裂. 本研究对于遗传工程中的化学核酸酶以及以DNA为靶标的药物设计有重要的意义.     

钌(Ⅱ)多吡啶配合物光断裂DNA的实验研究

研究了一系列钌(Ⅱ)多吡啶配合物对pBR 322DNA的光断裂作用,并与光谱法和粘度法的研究结果进行了对比．实验结果表明,钌(Ⅱ)多吡啶配合物光断裂DNA的能力不仅与配合物与DNA相互作用的结合模式和结合强度有关,还与配合物自身的电子结构有关;钌(Ⅱ)多吡啶配合物对DNA的光断裂存在立体选择性;其断裂机理是激发态的配合物与溶液中的氧分子发生能量转移生成单线态氧活性氧化物种,将鸟嘌呤碱基氧化而导致DNA断裂．本研究对于遗传工程中的化学核酸酶以及以DNA为靶标的药物设计有重要的意义．     

RuNi双核配合物识别DNA的分子机理研究

RuNi异金属双核配合物Ru(phen)_2(phen-cyclam-Ni)~(4+)(1)(phen=1,10-邻菲咯啉;cyclam=1,4,8,11-四氮杂环十四烷)和Ru(bpy)_2(bpy-cyclam-Ni)~(4+)”(2)(bpy=2,2 ’-联吡啶)具有多种重要的性质和功能;为了阐明它们在体外抗艾滋病病毒(HIV-1)活性方面的分子机理,我们用多种手段研究了这些化合物与DNA的相互作用。 1 实验部分 配合物1和2根据文献合成。粘度测定用乌氏粘度计在Pipes 00缓冲液中于300.2℃下进行。紫外可见光谱用Varian DMS 200 UV-Vis分光光度计在室温下测定。DNA断裂活性的测定采用DYY-Ⅲ4型电泳仪,0.8％的琼脂糖凝胶,电泳缓冲液用05×TBE。对pBR322质粒DNA的断裂结果在紫外透射及反射仪上观察和照相,并用紫外薄层扫描法进行初步定量分析。 2 结果与讨论 2.1 粘度测定 当用配合物1对DNA(CT-DNA)溶液进行滴定时,其特性粘度有较明显的     

多吡啶钌配合物作为DNA结构探针的研究

本文对多吡啶钌配合物作为DNA荧光或结构探针的研究背景、研究技术及其特点、钌配合物与DNA的键合模式及其结合力大小的影响因素、钌配合物与DNA键合的异构选择性及不同键合速率、非放射性核酸标记及DNA分子光开关等方面进行了简要述评     

手性双核钌(Ⅱ)配合物与DNA的相互作用研究

本文合成了1对手性双核钌(Ⅱ)配合物ΔΔ-和ΛΛ-[(bpy)₂Ru(mbpibH₂)Ru(bpy)₂](ClO₄)₄(bpy=2,2′-联吡啶,mbpibH₂=1,3-二(咪唑并[4,5-f][1,10-邻菲咯啉])苯)。通过元素分析、质谱、核磁共振、CD光谱对这两个化合物进行了结构表征。采用循环伏安法对配合物的电化学性质进行了分析。利用紫外-可见吸收光谱滴定、荧光光谱滴定     

钌配合物抗肿瘤研究新进展*

钌配合物作为抗癌药物的研究已受到广泛关注,成为无机药物化学的重要研究内容之一。本文简要评述了近年来钌配合物的抗肿瘤活性研究进展,包括作为细胞毒药物的钌配合物设计与筛选、钌配合物以端粒酶、DNA拓扑异构酶及蛋白激酶作为抗肿瘤作用新靶点等。     

钌(II)多吡啶配合物与DNA相互作用研究*

DNA是遗传信息的携带者和基因表达的物质基础,金属配合物与DNA的相互作用研究已受到广泛关注,成为生物无机化学的重要研究内容之一。本文简要评述了钌(II)多吡啶配合物在DNA识别、断裂及拓扑异构酶抑制方面的研究情况。     

Cationic ruthenium(II) complexes supported on mesoporous silica as catalyst precursors in the selective oxidative cleavage of 1‐octene

The selective oxidative cleavage of 1‐octene to heptanal and heptanoic acid is reported. A range of model and silica‐immobilized ruthenium(II) systems were evaluated. The MCM‐41 and SBA‐15 immobilized systems were found to show superior activity when compared to their homogeneous counterparts and were found to exert control over the selective formation of aldehydes or carboxylic acids. This could be achieved by varying the reaction times with very high yields being achieved at relatively short reaction times and low metal concentrations. The immobilized catalysts were characterized using nitrogen sorption, powder X‐ray diffraction, transmission and scanning electron microscopies, solid‐state NMR spectroscopy and thermogravimetric analysis.     

Crystal structures and DNA cleavage activities of two mononuclear nickel(II) complexes

Two new nickel complexes, [Ni(L₁)₂]?·?2(CH₃OH) (1) and [Ni(L₂)₂]?·?2(CH₃OH) (2), where HL₁ is 4-chloro-2-((2-hydroxy-ethylimino)methyl)phenol and HL₂ is 4-fluoro-2-((2-hydroxy-ethylimino)methyl)phenol, have been synthesized and characterized by single-crystal X-ray diffraction and UV-Vis absorption spectra. The coordination polyhedron of nickel(II) in each complex can be described as distorted octahedral. The interactions between the complexes and calf thymus (CT)-DNA/DNA were investigated by UV-Vis spectra and agarose gel electrophoresis. The results show that the complex transforms supercoiled to nicked form and exhibits effective DNA cleavage activity via hydrolytic cleavage mechanism.     

Hydrolytic cleavage of DNA by quercetin manganese(II) complexes

Quercetin manganese(II) complexes were investigated focusing on its DNA hydrolytic activity. The complexes successfully promote the cleavage of plasmid DNA, producing single and double DNA strand breaks. The amount of conversion of supercoiled form (SC) of plasmid DNA to the nicked circular form (NC) depends on the concentration of the complex as well as the duration of incubation of the complexes with DNA. The maximum rate of conversion of the supercoiled form to the nicked circular form at pH 7.2 in the presence of 100 μM of the complexes is found to be 1.32 × 10⁻⁴ s⁻¹. The hydrolytic cleavage of DNA by the complexes was supported by the evidence from free radical quenching, thiobarbituric acid-reactive substances (TBARS) assay and T4 ligase ligation.     

Conformational changes of DNA molecules in interactions with bioactive compounds. II. DNA complexes with coordination compounds of cobalt and ruthenium

A comparative analysis is made of the character of conformational changes of the DNA molecule in its interaction with coordination compounds of cobalt and ruthenium with different ligand sets in the coordination sphere of the ion. It is shown that during complexation global conformational changes of DNA (e.g., the reduction of its volume) practically do not depend on the location and on the binding mode of the complex ion, but are primarily determined by its charge, whereas local conformational changes of the macromolecule are very sensitive to the type of the complex being formed, as indicated by the change of spectral properties of DNA. An assessment of sizes of the particles that are formed as a result of DNA condensation due to its binding with trivalent ions of cobalt and ruthenium was performed with the use of dynamic light scattering.     

Oxidative and hydrolytic DNA cleavage by Cu(II) complexes of salicylidene tyrosine schiff base and 1,10 phenanthroline/bipyridine

Ternary Cu(II) complexes [Cu(II)(saltyr)(B)] (1,2), (saltyr = salicylidene tyrosine, B = 1,10 phenanthroline (1) or 2,2′ bipyridine (2)) were synthesized and characterized by various techniques. The complexes exhibit square pyramidal (CuN₃O₂) geometry. CT-DNA binding studies revealed that the complexes show good binding propensity (K_b = 3.47 × 10⁴ M⁻¹ and 3.01 × 10⁴ M⁻¹ for 1 and 2, respectively). The role of these complexes in the oxidative and hydrolytic DNA cleavage was studied. The catalytic ability of 1 and 2 follows the order: 1 > 2. The rate constants for the hydrolysis of phosphodiester bond were determined as 2.80 h⁻¹ and 2.11 h⁻¹ for 1 and 2, respectively. It amounts to (0.58-0.77) × 10⁸ fold rate enhancement compared to non-catalyzed DNA cleavage, which is significant.     

DNA-binding and cleavage activity of polypyridyl ruthenium(II) complexes

Polypyridyl ruthenium(II) complexes [Ru^II(3-bptpy)(dmphen)Cl]ClO₄ (1), [Ru^II(3-cptpy)(dmphen)Cl]ClO₄ (2), [Ru^II(2-tptpy)(dmphen)Cl]ClO₄ (3), and [Ru^II(9-atpy)(dmphen)Cl]ClO₄ (4) {where 3-bptpy?=?4′-(3-bromophenyl)-2,2′:6′,2″-terpyridine, 3-cptpy?=?4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine, 2-tptpy?=?4′-(2-thiophenyl)-2,2′:6′,2″-terpyridine, 9-atpy?=?4′-(9-anthryl)-2,2′:6′,2″-terpyridine, dmphen?=?2,9-dimethyl-1,10-phenanthroline} have been synthesized and characterized. The DNA-binding properties of the complexes with Herring Sperm DNA have been investigated by absorption titration and viscosity measurements. The ability of complexes to break the pUC19 DNA has been checked by gel electrophoresis. The experimental results suggest that all the complexes bind DNA via partial intercalation. The results also show that the order of DNA-binding affinities of the complexes is 4?<?3?<?2?<?1, confirming that planarity of the ligand in a complex is very important for DNA-binding.     

Oxidative DNA cleavage by copper ternary complexes of 1,10-phenanthroline and ethylenediamine-sulfonamide derivatives

Ternary copper(II) complexes (1–3) of 1,10-phenanthroline and ethylenediamine-R-sulfonamide derivatives (R = benzene, toluene and naphthalene rings) have been synthesized and characterized with the aid of X-ray diffraction and spectroscopic and electrochemical techniques. The crystal structures of the complexes show that the coordination polyhedron around copper(II) is distorted square planar. Both 1,10-phenanthroline and ethylenediamine-R-sulfonamide act as bidentate ligands. The three structures are stabilized by π–π stacking interactions. The interaction of the complexes with calf thymus DNA has been investigated by thermal denaturation studies which indicated that DNA was stabilized in the presence of the compounds. The increase in DNA stability induced by the complexes follows the order: 3 > 2 > 1. All three complexes were found to be very efficient agents of plasmid DNA cleavage in the presence of ascorbate as reducing agent. Mechanistic studies of the DNA cleavage process performed with radical scavengers show that the reactive oxygen species involved in the DNA damage are the hydroxyl radical, singlet oxygen-like species, the superoxide* and hydrogen peroxide.     

Synthesis and DNA cleavage properties of ternary Cu(II) complexes containing histamine and amino acids

The ternary complexes of [Cu^II(Hist)(Tyr)]⁺1 and [Cu^II(Hist)(Trp)]⁺2 have been synthesized, structurally characterized and their DNA binding and cleavage abilities probed. The intrinsic binding constants (K_b) for complexes/CT-DNA were also determined (K_b = 2.7 × 10² for complex 1 and K_b = 2.2 × 10² for complex 2). These complexes exhibit their nuclease activity on plasmid DNA, which seems to depend on the nature of the aromatic moiety. The DNA hydrolytic cleavage rate constants were also determined for complexes 1 and 2, which are 0.91 and 0.79 h⁻¹, respectively.