洛美沙星与Al^3＋及DNA相互作用的光谱研究

利用荧光和紫外光谱法研究了洛美沙星与Al^3＋及DNA的相互作用。实验结果表明,AP能够与洛美沙星（LMX）形成二元配合物,并且一定浓度范围内Al^3＋对DNA和LMX的结合具有明显的促进作用。讨论了LMX—AI（RI）配合物与DNA的结合机理,证实LMX—Al（Ⅲ）配合物通过沟槽结合的方式与DNA结合,为进一步研究洛美沙星药物的抗菌杀菌机理提供了参考依据。     

金属配合物与DNA相互作用的研究进展

DNA是生物体中一类重要的生物大分子,对生命遗传密码的翻译、转录、复制起着非常重要的作用,一方面,DNA靶向化合物成为很重要的核酸探针选择对象;另一方面,临床上使用的许多抗癌药物都以DNA为作用靶点.以金属配合物与DNA的作用机理为主要内容,阐述了紫外光谱法、荧光光谱法、电化学法等多种仪器分析方法在研究金属配合物与DNA相互作用中的应用,并对今后的发展趋势进行了展望.     

四环素-铜（Ⅱ）配合物与DNA相互作用的吸收光谱研究

用紫外光谱方法研究了四环素(TC)-Cu(Ⅱ)配合物与DNA的相互作用．吸收光谱研究表明，DNA能与四环素(TC)及Cu(Ⅱ)形成的配合物发生反应，配合物与DNA的作用方式随着配合物类型及DNA浓度的不同而不尽相同：当四环素与铜形成1：1型配合物时，较低浓度的DNA能与配合物以嵌插方式相互作用，而较高浓度的DNA与该配合物除了发生嵌插作用外，还存在另外的作用方式；当四环素与铜形成1：2型配合物时，DNA与该配合物则主要以嵌插方式相互作用，并且这两种配合物与DNA的嵌插作用均是通过四环素配体插入的．     

一种席夫碱钴(Ⅱ)配合物的合成及其与DNA的相互作用

以邻苯二胺、水杨醛和乙酸钴为原料,合成了一种新型的席夫碱钴(Ⅱ)配合物(CoL,L=双水杨醛缩邻苯二胺),采用红外光谱和元素分析对配体及配合物结构进行了表征。在pH 7.0的Britton-Robinson(B-R)缓冲溶液中,采用紫外光谱法、粘度法和循环伏安法研究了该席夫碱钴(Ⅱ)配合物与DNA的相互作用。紫外光谱实验表明DNA的加入能引起配合物特征吸收峰的减色效应,表明了二者之间的相互作用,通过光谱滴定法测得二者的结合常数为1.1×104L/mol。粘度实验显示,随着配合物浓度的加大,DNA相对粘度先增大后减小,说明二者之间通过部分嵌插模式结合。电化学实验表明配合物在玻碳电极上有一对对应于中心Co(Ⅱ)离子的氧化还原峰,当加入一定量的DNA后,该对氧化还原峰电流显著降低,进一步表明席夫碱钴配合物与DNA发生了相互作用。     

Synthesis and DNA Binding Properties of a Water-Soluble CHT-Co（Ⅱ） Complex

以1,10-菲罗啉、壳聚糖和四水合乙酸钴为原料,合成了水溶性壳聚糖钴（II）配合物（CHT-Co（II））,采用红外光谱对配体及配合物进行了表征。在pH 7.5的Tris-HCl缓冲溶液中,采用粘度法、紫外可见吸收光谱法和电化学方法（循环伏安法,微分脉冲伏安法）研究了配合物与DNA的相互作用。粘度法表明二者能发生部分嵌插作用;DNA的加入能引起配合物紫外光谱的变化也表明了二者之间的相互作用。电化学实验表明配合物在玻碳电极上的氧化还原为一可逆过程,当加入一定量的DNA时,配合物的氧化峰电流明显降低,式电位有所正移,验证了二者之间存在部分嵌插作用。     

壳寡糖席夫碱Cu(Ⅱ)配合物与鲱鱼精DNA的相互作用?

以壳寡糖与对羟基苯甲醛反应合成的席夫碱化合物作为配体,构建了一系列的金属Cu(Ⅱ)配合物,并通过紫外光谱法、电化学手段以及粘度实验,初步研究了配合物与DNA的作用机理。紫外光谱实验发现,配合物的特征吸收峰在加入DNA后峰位均呈现红移和减色;从循环伏安曲线可见,DNA加入后配合物的氧化峰电流呈下降趋势,峰电位伴随有正移趋势;DNA的粘度随着配合物浓度的依次增大,呈先增大后降低的趋势。结合以上这些信息,认为配合物与DNA以部分嵌插方式作用的。     

3,5-二硝基苯甲酸钐与1,10-邻菲罗啉配合物的合成、性能及与小牛胸腺DNA作用研究

以3,5-二硝基苯甲酸(HL)和1,10-邻菲罗啉(Phen)为配体,采用溶液合成法合成了一种钐配合物。通过元素分析、配位滴定、摩尔电导率、红外光谱和紫外光谱法确定了配合物的组成为Sm(L)3phen。利用热分析、电化学手段对配合物的热稳定性、电化学性能进行了分析。应用粘度法对配合物与小牛胸腺DNA的相互作用进行了研究。结果表明,钐配合物和DNA相互作用是插入模式。     

双水杨醛缩邻苯二胺-Ce（Ⅲ）配合物的生物活性研究

合成了一种salen稀土金属双水杨醛缩邻苯二胺ce（Ⅲ）配合物,其结构用紫外光谱、红外光谱、核磁共振及电喷雾质谱进行表征。用纸片法测定配合物对大肠杆菌和枯草杆菌的抗菌活性,表明配合物对大肠杆菌有较好的抗菌活性。用紫外光谱和荧光光谱研究配合物与小牛胸腺DNA（ctDNA）的相互作用,初步表明配合物与DNA之间很可能是嵌入作用、静电作用的方式并存,并且配合物还可作为DNA的荧光染料。     

双水杨醛缩邻苯二胺钙配合物与DNA相互作用的光谱性质

合成了新的双水杨醛缩邻苯二胺钙配合物,并通过红外光谱、核磁共振谱法对其结构进行表征,并利用紫外光谱和荧光光谱法研究了钙配合物与DNA的相互作用方式,实验研究表明配合物与DNA之间很可能是嵌入作用和部分嵌入作用并存。     

多核铜槲皮素配合物对DNA的作用研究

应用紫外光谱、凝胶电泳法实验探究了3种多核铜槲皮素配合物与DNA的作用形式及对DNA的裂解能力。结果显示,3种配合物对DNA的作用效果强于槲皮素,配合物通过插入、静电、剪切多种形式与DNA作用,具有高效的DNA断裂活性。     

光度法研究姜黄素金属络合物与鲑鱼精DNA的相互作用

采用紫外可见分光光度法研究了姜黄素(CUR)的光谱特性及其金属络合物与鲑鱼精DNA的相互作用。结果表明,在pH值为6.5的Tris-HCl缓冲溶液中,姜黄素的特征吸收峰在430 nm处,Fe3+-CUR形成了1∶3的金属络合物,其结合常数KD=4.326×104L/mol,确定了Fe3+-CUR与鲑鱼精DNA之间有嵌插作用存在,其结合常数KD=136.24 L/g。     

乳酸-钴(Ⅱ)-1,10-菲啰啉三元配合物与DNA结合的光谱与电化学研究

以1,10-菲啰啉(phen)和乳酸为配体合成了三元钴配合物[Co(phen)(la)_2]。采用紫外光谱、循环伏安法、计时库仑法和微分脉冲伏安法等考察了其与鲱鱼精天然DNA的相互作用。紫外光谱实验显示,在[Co(phen)(la)_2]中加入DNA后,配合物在270 nm处的紫外特征吸收峰出现明显的减色效应,并伴随红移,表明[Co(phen)(la)_2]可通过其phen配体插入DNA中相邻碱基对。循环伏安法和计时库仑法进一步表明,与DNA结合后,复合物在水溶液中扩散系数降低,从而导致电化学信号减弱。微分脉冲伏安实验显示,[Co(phen)(la)_2]氧化峰电流与DNA浓度在2.66×10~(-5)~1.34×10~(-4)mol/L范围内呈现良好的线性关系,表明[Co(phen)(la)_2]可作为一种潜在的DNA检测探针。     

微波辅助四（p-甲氧苯基）卟啉铜（Ⅱ）的合成及其与c-myc G4 DNA的相互作用

以吡咯、p-甲氧基苯甲醛为原料,丙酸为溶剂,130℃ 条件下制得四（p-甲氧苯基）卟啉（TMOPP）;然后在100℃ 微波辐射条件下,以TMOPP和乙酸铜为原料,DMF为溶剂,制得目标化合物四（p-甲氧苯基）卟啉铜（Ⅱ）配合物 （CuTMOPP）。采用电喷雾质谱、紫外光谱和红外光谱等分析方法对所合成的目标化合物进行了表征,目标化合物的理论值和实验值基本一致。进一步采用紫外光谱、CD光谱、FRET熔点实验、PCR-Stop实验考察了目标化合物与c-myc G4 DNA的相互作用,结果表明目标化合物可能与c-myc G4 DNA以静电方式结合,从而抑制其复制,进一步对其生物功能的影响还在研究中。     

[Ru(L)2(3-tppp)]2 + (L = bpy,phen) stabilizes two different forms of the human telomeric G-quadruplex DNA

The binding properties of new complexes [Ru(L)₂(3-tppp)]^2 + (L = bpy, phen) towards two different forms of the human telomeric G-quadruplexes DNA have been investigated by UV–Vis spectroscopy, fluorescent indicator displacement (FID) assays, fluorescence resonance energy transfer (FRET) melting assays and molecular docking studies. The molecular docking studies indicated that both complexes interacted with 22AG with the stoichiometric ratio of 1:1, but the two complexes showed different G-quadruplexed DNA binding affinity. Complex 2 bound to the G-quadruplexes DNA more tightly than complex 1 did. Moreover, the FRET melting assay revealed that both complexes could be potential stabilizers for G-quadruplex architectures. These studies are useful not only for better understanding of the interaction between the target G-quadruplexes DNA and metal complexes but also valuable in defining the best strategy to prepare metal complexes as potential anticancer drugs.     

PLFX-Co(phen)_3~(2+)复合物与CT-DNA的结合性质及切割活性

利用荧光光谱及流体动力学等方法,研究了普利沙星(PLFX)-Co(phen)32+与CT-DNA间的作用机理。荧光光谱测量结果表明:普利沙星和Co(phen)32+发生了结合作用形成了复合物,配比为2∶1;向PLFX-Co(phen)32+体系中,加入CT-DNA后,复合物进一步与DNA相结合,结合常数为2.18×105L/mol。通过粘度法、熔点测定及凝胶电泳实验研究了复合物与CT-DNA的相互作用。结果表明体系与CT-DNA间主要是沟槽作用;PLFX-Co(phen)32+能够有效切割质粒DNA。     

钌(Ⅱ)多吡啶配合物与G-四链体DNA的相互作用研究

应用圆二色光谱、紫外-可见吸收光谱、荧光光谱等实验研究在H2O溶液中钌(II)多吡啶配合物[Ru(phen)2(Hecip)](ClO4)2(phen=1,10-邻菲啰啉,Hecip=2(9-乙基-9H-咔唑-3-基)-1H-咪唑并[4,5-f][1,10]菲啰啉)与G-四链体DNA(AG3(T2AG3)3)相互作用。圆二色光谱实验表明,配合物能够诱导无序的G-四链体DNA以平行构型和反平行构型的共存体存在;从紫外和荧光滴定实验表明配合物与G-四链体之间存在较强的亲和力,拟合得到的结合常数可达106。     

Effect of ion-binding on the formation of temporary viscoelastic networks of proanthocyanidin biopolymers

The gel formation of the alkali salts of proanthocyanidin polymers from Pinus radiata bark with calcium(II) and aluminum(III) has been investigated. The calcium- and aluminum-induced gelation of the hot water extract (HWE) has been studied by UV spectroscopy as well as through conductivity and rheological measurements. The ability of an HWE to complex was observed to increase significantly as the solution's pH became more alkaline, and the conductivity data are consistent with UV spectra with respect to structural change as metal binding occurs. The addition of the cationic species Ca²⁺ and Al³⁺ markedly increased the elasticity of the extracts, even at low extract concentration. Rheological measurements of metal binding in the HWE paralleled the UV spectral and conductivity behavior, thus indicating that the HWE binds more readily with calcium than with aluminum. In the concentrated HWE system, maximum association of the HWE with metal ions was found to appear at the same molar ratio of 3.6. The addition of such cationic species to the extracts is thought to reduce their fluidity primarily by increasing the number of physical electrostatic crosslinks. Such an increase results, in turn, in an increase in the apparent molecular weight of extract polymers and a decrease in fluidity. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1795–1805, 1997     

The Interaction of Sheep Genomic DNA with a Cobalt(II) Complex Containing p-Nitrobenzoate and N,N′-Diethylnicotinamide Ligands

The synthesized cobalt(II) complex, CoPNBDENA and the binding of this complex with sheep genomic DNA were investigated by UV–Visible absorption and viscosity techniques. Also the interaction of sheep genomic DNA with the complex was studied using the agarose gel electrophoresis method. The results indicated that the complex interacted with DNA. The nature of the binding seemed to be mainly an electrostatic interaction between DNA and the cobalt(II) complex. Other binding modes such as hydrogen bonds may also exist in this system. In this study, after the interaction of DNA–CoPNBDENA, it was observed that the migration of the DNA band became slow as the amount of cobalt(II) complex was increased. This clearly demonstrates that the CoPNBDENA complex neutralizes the negative charges of DNA.     

Synthesis of New Five Coordinated Copper(II) and Nickel(II) Complexes of L-Valine and Kinetic Study of Copper(II) with Calf Thymus DNA

Five coordinated novel complexes of CuII and NiII have been synthesized from benzil and 1,3- diaminopropane-CuII/NiII complex and characterized by elemental analysis, i.r., n.m.r., e.p.r, molar conductance and u.v-vis, spectroscopy. The complexes are ionic in nature and exhibit pentaeoordinated geometry around the metal ion. The reaction kinetics of C25H36N5O2CuCl with calf thymus DNA was studied by u.v-vis, spectroscopy in aqueous medium. The complex after interaction with calf thymus DNA shows shift in the absorption spectrum and hypochromicity indicating an intercalative binding mode. The Kobs values have been calculated under pseudo-first order conditions. The redox behaviour of complex C25H36N5O2CuCl in the presence and in the absence of calf thymus DNA in the aqueous solution has been investigated by cyclic voltammetry. The cyclic voitammogram exhibits one quasi-reversible redox wave corresponding to CuII/CuI redox couple with E1/2 values of -0.377 and -0.237 V respectively at a scan rate of 0.1Vs-1 .On interaction with calf thymus DNA, the complex C25H36N5O2CuCl exhibits shifts in both Ep as well as in E1/2 values, indicating strong binding of the complex to the calf thymus DNA.