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新型咪唑啉金属配合物的合成及其与DNA的相互作用

Synthesis of Novel Metal Complexes of Imidazoline and Their Interaction with DNA

【作者】 张金艳

【导师】 肖小明;

【作者基本信息】 湖南师范大学 , 有机化学, 2010, 硕士

【摘要】 本文综述了化合物与核酸相互作用方式及其研究的发展状况,总结了化合物与核酸作用的研究方法、研究技术、发展方向及其应用前景,简单介绍了咪唑啉类化合物合成方法及研究进展,以及在医药、缓蚀剂、表面活性剂和催化剂等方面的应用。本课题采用微波辐射法,由吡啶-2,6-二甲酸与乙二胺一步合成了2,6-二(2’-咪唑啉-2’-基)吡啶化合物,收率达到71%,反应时间仅为1.5h。而文献曾报道用吡啶-2,6-二甲酸、SOCl2、P2S5、乙二胺等为原料,通过多步反应合成了此化合物,但操作繁琐、耗时长,且产生有毒气体,收率仅为47.7%。相比之下,采用微波辐射法显著缩短了反应时间,提高了收率,减少了环境污染。采用常规方法,合成了铬、锌、铜、镍四种过渡金属的2,6-二(2’-咪唑啉-2’-基)吡啶配合物,并通过红外、紫外、核磁、摩尔电导率、元素分析、热重分析等对其进行了表征与分析,推测出配合物的化学式分别为:[ZnLNO3]NO3、[CuLNO3]NO3·2H2O、[NiLNO3]NO3·2H2O、[CrL2][NO3]3。配合物的红外光谱、紫外光谱、核磁数据相对配体都发生了不程度的移动,充分说明金属离子已与配体发生配位作用。采用紫外光谱、黏度法研究了这四种过渡金属配合物及配体与DNA的相互作用。研究发现:这些物质与DNA作用时,紫外吸收都发生了不同程度的增色,表明它们与DNA发生氢键作用;DNA溶液黏度随配合物浓度增加而减少,表明配合物与DNA发生了静电作用,而DNA溶液黏度随配体浓度增加变化不明显,表明配体与DNA可能发生了沟面结合作用。本工作还运用Guassian 03量子化学程序包中的密度泛函理论(DFT),研究了由吡啶-2,6-二甲酸与乙二胺一步合成2,6-二(2’-咪唑啉-2’-基)吡啶化合物的反应过程。对化合物和脱氧核糖核苷酸单体(dAMP, dGMP, dTMP, dCMP)全自由度几何优化。相同水平计算得到分子NBO电荷、分子半径、偶极矩、分子总能量、分子前线轨道能量、红外光谱图。通过TD-DFT方法,计算紫外吸收光谱。采用规范不变原子轨道GIAO法,计算它们的1H NMR和13C NMR化学位移值。通过分析比较,计算值与理论值在一定程度上相对一致。并模拟了化合物与DNA相互作用,得到了与实验一致的结论。

【Abstract】 The investigation of the interaction between molecule and nucleic acid was fully described in the dissertation paper. It involved interaction modes and research methods and research techniques. The direction and prospects of the interaction between molecule and nucleic acid were also expatiated. The recent advances in the study of imidazolines and their derivatives and their application of drugs in medicine, corrosion resistance in industry, surfactant in lives and catalysts in synghesis were reviewed.2,6-di(2’-imidazoline-2’-yl)pyridine (dimlpy, ligand, L) has been synthesized by using pyridine 2,6-dicarboxylic acid and ethylenediamine under the condition of microwave irradiation and catalyst free. The overall yield was 71% and the irradiation time was 1.5 h. The method provided a simple and inexpensive access to the title compound. The method has a characteristic of low energy consumptions and environmental protection. Compared with the conventional methods, this procedure has the advantages of simple operation and short reaction times. However, it had been synthesized by using pyridine 2,6-dicarboxylic acid, SOC12, P2S5, and ethylenediamine by Baker. The overall yield was only 47.7%. But this method provided an expensive and intricacy access to the title compound. The method has a characteristic of environmental pollution.The four complexes of chromium (Ⅲ), zinc (Ⅱ), copper (Ⅱ) and nickel (Ⅱ) with 2,6-di(2’-imidazoline-2’-yl)pyridine were synthesized in the conventional condition and characterized by infrared spectroscopy, UV, NMR, mass spectrometry, elemental analyses, molar conductivity, TG-DSC. The results showed that the complexes had been synthesized successfully and the general chemical formulas were [CrL2][NO3]3, [ZnLNO3]NO3, [CuLNO3]NO3-2H2O, [NiLNO3]NO3·2H2O, respectively.UV absorption and viscosity measurements were used to study of these complexes and ligand interaction with DNA. The absorbance of the complexes and ligand all increase, but the wavelength has not red shifted with increasing DNA concentration. The results of viscosity measurements reveal that the presence of these complexes decreases the relative viscosity of DNA. So, these complexes may bind to DNA by hydrogen bonding and external electrostatic binding. But, the results of viscosity measurements reveal that the presence of ligand has no obvious effect on the relative viscosity of DNA. It may bind to DNA by hydrogen bonding and groove-face binding.Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) with hybrid functional B3LYP were used to investigate several physical and chemical properties of the compounds, including the geometry, electron structure, charge population, IR, NMR, as well as UV absorption spectra. Other physicochemical characteristics, such as bond lengths, dipole moments, energies of the lowest unoccupied (LUMO) and highest occupied (HOMO) molecular orbitals, molecular total energy and Fukui functions were also obtained from theoretical calculations. Calculations were also reported to explain the experimental behavior of these systems. The calculated UV absorption spectrum was in good agreement with the experimental spectrum. This was also confirmed by a comparison of experimental IR with frequencies derived theoretically.1H and 13C chemical shifts obtained at the gauge-independent atomic orbital (GIAO) level of theory were explained. Synthetic principle and the interaction between the compounds and DNA have been discussed. Calculations were also reported to explain the interaction between these compounds and DNA. The calculated conclusions were in good agreement with the experimental phenomena.

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