特异识别和切割DNA的过渡金属配合物

利用过渡金属配合物及其载体衍生物识别和切割ＤＮＡ是近十年来发展起来的新型分子生物学和基因工程工具试剂。作为ＤＮＡ构象变化的探讨，ＤＮＡ－蛋白质相互作用分析的足迹试，或基因组和染色体作图和测试的工具试剂已受到了广泛极大重视。     

Schiff碱,咪唑金属配合物的合成与抗癌活性

报道一类新的Ｓｃｈｉｆｆ碱和咪唑的混合型金属配合物，即水杨醛缩甘氨酸，咪唑金属配合物和２，４－二羟基苯甲醛缩丙氨酸，咪唑金属配合物的合成，用溴化乙锭荧光分析法研究了这类配合物与ＤＮＡ的相互作用，其中镍配合物与ＤＮＡ的作用明显。     

三核过渡金属配合物在催化反应中的研究进展

多核过渡金属配合物作为一类广泛应用的均相催化剂,其设计灵感往往来自天然酶的多金属活性位点所发挥的重要作用.目前,三核金属配合物作为活化小分子的多金属催化剂受到了广泛的关注.为深入理解三核过渡金属配合物在催化反应中作用特点,对近年报道的代表性三核过渡金属配合物按金属中心进行分类,并对配体环境形成特点及催化应用进行综述.从金属中心出发,讨论了三核过渡金属配合物的几何结构和电子特征;从配体环境出发,总结了关联三个独立的金属位点的配位环境特征;在催化应用方面,重点综述了三核过渡金属配合物在涉及特定化学键活化反应的催化作用机制,最后对三核过渡金属配合物的催化应用前景进行展望.     

Schiff碱,咪唑金属配合物合成及抗癌活性的荧光筛选研究

本文报道了一类新的Ｓｃｈｉｆｆ碱和唑的混合型金属配合物（即水杨醛缩甘氨酸，咪唑金属配合物和２．４－二羟基苯甲醛缩丙氨酸，咪唑金属配合物）的合成，以及用溴化乙锭荧光分析法对这类配合物与ＤＮＡ相互作用的研究。结果表明，其中金属镍配合物与ＤＮＡ的作用效明显，可作为具有抗癌作用的药物进行深入研究。     

Schiff碱、咪唑金属配合物合成及抗癌活性的荧光筛选研究

本文报道了一类新的Ｓｃｈｉｆｆ碱和咪唑的混合型金属配合物（即水杨醛缩甘氨酸、咪唑金属配合物和２．４—二羟基苯甲醛缩丙氨酸、咪唑金属配合物）的合成，以及用深化乙锭荧光分析法对这类配合物与ＤＮＡ相互作用的研究。结果表明，其中金属镍配合物与ＤＮＡ的作用较明显，可作为具有抗癌作用的药物进行深入研究。     

β-K4H3[SiW9O37(CpTi)3]·11H2O环戊二烯钛多酸衍生物与DNA作用研究

某些过渡金属配合物具有特异性催化DNA和RNA断裂的功能, 因而研究过渡金属配合物对DNA和RNA的断链反应对新型抗肿瘤、抗艾滋病化学药物的定向设计及其基因治疗和分子生物学中DNA和RNA的高度专一性定点断裂、 DNA定位诱变和构象识别具有重要意义和应用前景[1,2]. 我们对二茂钛多酸有机金属衍生物合成及抗肿瘤活性研究表明, 环戊二烯钛多氧金属酸盐衍生物具有很高的抗肿瘤活性和较好的水溶性及稳定性, 有潜在的抗肿瘤药用价值[3].     

过渡金属膦配合物在硅氢化反应中的应用研究

过渡金属膦配合物在有机合成和催化反应中的应用非常广泛, 大量含膦杂原子配体被设计合成, 利用其特定的配位能力, 和过渡金属配位成过渡金属膦配合物, 并测试其对特定有机化学反应的催化性能. 硅氢加成反应是有机硅化学中的重要反应, 多种过渡金属包括铂、钯、铑、钌等的膦配合物对于硅氢加成反应均有催化活性. 综述了近几年来过渡金属膦配合物在硅氢加成反应中的应用进展.     

过渡金属氢化物的合成方法

概述了过渡金属氢化物尤其是钌氢配合物的氧化加成、M-X还原、质子化、过渡金属氢化物转化和原子簇过渡金属配合物氢聚等合成方法的进展情况.     

手性席夫碱配合物用于催化不对称环氧化

手性席夫碱过渡金属配合物可以高效催化烯烃不对称环氧化反应,因此其合成及催化性能研究一直以来受到广泛的关注.本文较详细地综述了最近十年来合成的手性席夫碱过渡金属配合物及其对烯烃环氧化反应的催化性能的研究进展.重点讨论了新型的对称和非对称salen型配体过渡金属配合物的合成及其应用,分析探讨了手性席夫碱过渡金属配合物作为催化剂的优缺点、催化机理和未来发展方向.     

异构化的π-丁二烯二羰基(乙氧基芳基卡宾)铁配合物的质谱研究

1964年Fischer等报道了第一个过渡金属卡宾配合物以来,为数众多的过渡金属配合物已被合成和鉴定。最近我们合成了一系列异构化的π-丁二烯二羰基(乙氧基芳基卡宾)铁配合物,并研究了它们的红外光谱和核磁共振谱。本文报道这类新型配合物的低分辨电子轰击电离(EI)质谱,探讨其可能的断裂途径。它们的EI质谱表明,存在一系列具有结构信息的特征离子,相应的特征峰有助于配合物的结构鉴定。根据红外光谱分析和X-射线晶体结构分析,这些新型配合物具有下面两种结构类型,其中3为B型结构,其它均为A型结构。     

Development of a Metal‐Ion‐Mediated Base Pair for Electron Transfer in DNA

A new C‐nucleoside structurally based on the hydroxyquinoline ligand was synthesized that is able to form stable pairs in DNA in both the absence and the presence of metal ions. The interactions between the metal centers in adjacent Cu^II‐mediated base pairs in DNA were probed by electron paramagnetic resonance (EPR) spectroscopy. The metal–metal distance falls into the range of previously reported values. Fluorescence studies with a donor–DNA–acceptor system indicate that photoinduced charge‐transfer processes across these metal‐ion‐mediated base pairs in DNA occur more efficiently than over natural base pairs.     

Analytical applications of Raman spectroscopy

In this article interaction of transition metal complexes with DNA and its applications in electrochemical DNA biosensors as hybridization indicator or electroactive marker of DNA are reviewed. Special emphasis has been given to the efforts for the development of new transition metal complexes and their interaction to DNA. DNA and polymers covalently conjugated with transition metal complexes were also reviewed.     

二价金属离子对平阳霉素与DNA作用的影响

二价金属离子对平阳霉素与ＤＮＡ作用的影响王自春，黄登宇，袁静明（山西大学分子科学研究所，太原，０３０００６）关键词二价金属离子，平阳霉素，ＤＮＡ平阳霉素（简称ＢＬＭ－Ａ５）是抗肿瘤抗生素博莱霉素的成分之一，其化学结构、理化性质和药理作用虽基本相同［１...     

Effect of divalent metal ions on DNA studied by capillary electrophoresis

Divalent metal ions, such as Zn(2+), Co(2+), and Ni(2+), are capable of incorporating into DNA under certain conditions to form complexes termed M-DNA. To better understand the effects of these cations on DNA we used capillary electrophoresis (CE). The presence of these metal ions in a typical genotyping buffer led to broad peaks with low fluorescence intensities. In addition, some of the metal-complexed DNA molecules had different electrophoretic mobilities than their normal DNA counterparts. It is likely that the mobility shifts observed in the electropherograms of these affected fragments are due to the divalent cations causing structural changes in the single-stranded DNA. However, as can be seen from the resulting peak shapes, the structure, charge, and/or mass changes due to metal binding are not conserved among all of the DNA fragments. The extent of both peak-broadening and mobility shifts were found to be dependent on the metal cation and its concentration, the length of time that the DNA sample existed in formamide prior to injection into the capillary, and also the fragment size and sequence. These results suggest that the presence of metal ions might be responsible for the poor CE performance that occurs when genotyping certain kinds of DNA samples.     

DNA modified with metal complexes: Applications in the construction of higher order metal–DNA nanostructures

DNA has recently emerged as a useful building block for higher order nanostructures, such as extended two-dimensional surfaces and discrete two- and three-dimensional structures. Transition metal complexes can introduce functionality to these otherwise passive nanostructures. This review examines the synthetic strategies used to introduce metals in a site-specific manner to DNA: either by attaching preformed metal complexes to DNA, or by metal coordination to unmodified or modified DNA. The applications of metal–DNA complexes in building higher order nanostructures and the utility of attaching luminescent or electrochemical labels are discussed.     

Influence of Mg2+ and Cd2+ on the interaction between sparfloxacin and calf thymus DNA

Mg(2+) and Cd(2+) have different binding capacity to sparfloxacin, and have different combination modes with calf thymus DNA. Selecting these two different metal ions, the influence of them on the binding constants between SPFX and calf thymus DNA, as well as the related mechanism have been studied by using absorption and fluorescence spectroscopy. The result shows that Cd(2+) has weak binding capacity to SPFX in the SPFX-Cd(2+) binary system, but can decrease the binding between SPFX and DNA obviously in SPFX-DNA-Cd(2+) ternary system. Mg(2+) has strong binding capacity to SPFX. It can increase the binding between SPFX and DNA at concentrations <0.01 mM, and decrease the binding between them at concentrations >0.01 mM. Referring to the different modes of Mg(2+) and Cd(2+) binding to DNA, the mechanism of the influence of metal ions on the binding between SPFX and DNA has been proposed. SPFX can directly bind to DNA by chelating DNA base sites. If a metal ion at certain concentration mainly binds to DNA bases, it can decrease the binding constants between SPFX and DNA through competing with SPFX. While if a metal ion at certain concentration mainly binds to phosphate groups of DNA, it can increase the binding constants by building a bridge between SPFX and DNA. The influence direction of metal ions on the binding between quinolone and DNA relays on their binding ratio of affinity for bases to phosphate groups on DNA. Our result supports Palumbo's conclusion that the binding between SPFX and the phosphate groups is the precondition for the combination between SPFX and DNA, which is stabilized through stacking interactions between the condensed rings of SPFX and DNA bases.     

Evaluation of complexes of DNA duplexes and novel benzoxazoles or benzimidazoles by electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry is used to compare the metal ion binding and metal-mediated DNA binding of benzoxazole (1, 2, 3, 4) and benzimidazole (5) compounds and to elucidate the putative binding modes and stoichiometries. The observed metal versus non-metal-mediated DNA binding, as well as the specificity of DNA binding, is correlated with the biological activities of the analogs. The ESI-MS spectra for the antibacterial benzoxazole and benzimidazole analogs 4 and 5 demonstrated non-specific and non-metal-mediated binding to DNA, with the appearance of DNA complexes containing multiple ligands. The anticancer analog 2 demonstrates a clear preference for metal-mediated DNA interactions, with an apparent selectivity for Ni2+ -mediated binding over the more physiologically relevant Mg2+ or Zn2+ cations. Complexation between DNA and the biologically inactive analog 1 was not observed, either in the absence or presence of metal cations.     

Influence of metal ions on the interaction between gatifloxacin and calf thymus DNA

To study the interaction between gatifloxacin (GT), metal ions (Cu²⁺, Cd²⁺, Co²⁺, Mg²⁺) and calf thymus DNA under condition of physiology pH, UV absorption and fluorescence methods were adopted. Result shows that metal ions and DNA are able to react with GT in ground state. In further research, by studying the influence of metal ions on binding of GT with DNA in metal ions–GT–DNA ternary system, we found that influential mechanism of Mg²⁺ on the binding of GT with DNA may be different from the other three. Mg²⁺ can act as a bridge in the binding of GT's carboxyl/carbonyl with DNA phosphate in certain concentration range; while Cu²⁺, Cd²⁺, Co²⁺ can combine directly with GT by reaction between GT carboxyl/carbonyl and DNA base, and enhance the binding ability of GT with DNA. The influence extent and type depend not only on the binding site of DNA with metal ions (phosphate or base), but also the binding ability of which. The stronger the binding ability of metal ions with DNA base is, the larger their promotion to binding of GT with DNA is. The order of metal ions’ influential ability on the binding of GT–DNA is identical to the binding ability order of metal ions with DNA base, that is: Cu²⁺ > Cd²⁺ > Co²⁺ > Mg²⁺.     

金属离子与DNA相互作用的研究进展

对金属离子与DNA相互作用的研究进展进行了综述,讨论了不同金属离子与DNA碱基的作用位点以及不同金属离子与DNA相互作用的特点.     

DNA sequencing with titanium nitride electrodes

We construct a hydrogen‐bond based metal–molecule–metal junction, which contains two identical “reader” molecules, one single DNA base as a bridged molecule, and two titanium nitride electrodes. Hydrogen bonds are formed between “reader” molecules and DNA base, whereas titanium–sulfur bonds are formed between “reader” molecules and titanium nitride electrodes. We perform electronic structure calculations for both the bare bridged molecule and the full metal–molecule–metal system. The projected density of states shows that when the molecule is connected to the titanium nitride electrode, the energy levels of the bridged molecule are shifted, with an indirect effect on the hydrogen bonds. This is similar to the case for a gold electrode but with a more pronounced effect. We also calculate the current–voltage characteristics for the molecular junctions containing each DNA base. Results show that titanium nitride as an electrode can generate distinct conductance for each DNA base, providing an alternative electrode for DNA sequencing. © 2013 Wiley Periodicals, Inc.