席夫碱稀土配合物与DNA的作用方式

以糠醛和对氨基苯磺酸反应合成席夫碱配体,与稀土离子配位制得相应的稀土配合物,并运用光谱法研究配合物与DNA之间的作用机制,为新型抗癌药物的设计开发提供依据。采用元素分析、红外和紫外光谱对配合物性质进行表征测试,确定其化学组成为REL(OH),RE为La~(3+)、Nd~(3+)、Eu~(3+),L为去质子形式的希夫碱配体。此外,运用光谱法和循环伏安法研究了REL(OH)配合物与鲱鱼精DNA之间的作用方式。配合物在加入DNA后,特征吸收峰强度发生明显的减色效应,但峰位红移不明显。配合物能够猝灭中性红-DNA体系的荧光。Fe(CN)_6~(3-)/~(4-)的氧化还原峰电流在配合物加入后减小,式量电位有正移趋势,表明配合物、Fe(CN)_6~(3-)/~(4-)与DNA的作用存在竞争。研究结果表明:这3种席夫碱稀土配合物与鲱鱼精DNA的作用均属于嵌插,且含有不同稀土离子的配合物与DNA的作用强弱不同,作用大小次序为Eu配合物La配合物Nd配合物席夫碱,这可能与DNA和配合物中的稀土离子所发生的作用有关。     

8-氮杂腺嘌呤及其金属配合物与DNA的作用机理

8-氮杂腺嘌呤是抗代谢类药物,临床上广泛用于治疗增殖很快的肿瘤。文章以溴化乙啶为探针,通过紫外光谱,荧光光谱,研究了8-氮杂腺嘌呤及其与Co2+和Cu2+ 离子形成的配合物同DNA的作用。结果发现：在pH 9.86时,8-氮杂腺嘌呤可与Co2+形成稳定配合物,此配合物与DNA之间静电作用较强、嵌插作用较弱;在pH 7.4时,8-氮杂腺嘌呤可与Cu2+形成稳定配合物, 其与DNA之间主要以嵌插作用为主、静电作用为辅;在pH 2.85时,8-氮杂腺嘌呤-Cu2+配合物与DNA之间嵌插作用较强、静电作用较弱;在pH 7.4时,8-氮杂腺嘌呤几乎不影响EB和DNA之间的嵌入结合方式, 它与DNA为静电方式结合。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理论依据。     

染料木素铬(Ⅲ)配合物与DNA相互作用的研究

在pH 7.2 Tris缓冲溶液中,采用紫外、DNA熔点、荧光、粘度等手段研究了染料木素铬(Ⅲ)配合物与小牛胸腺DNA(ctDNA)的作用机制,探讨了其作用模式。当加入一定量的ctDNA时,染料木素铬(Ⅲ)配合物的紫外吸收光谱的最大吸收峰产生明显的减色效应;而配合物体系的荧光强度、共振光散射信号随ctDNA的加入逐渐增强。配合物的存在能有效猝灭EB-DNA体系的荧光,且猝灭方式为静态猝灭。同时ctDNA的熔点和ctDNA溶液的粘度随配合物的加入而增大。据此推断,染料木素铬(Ⅲ)配合物与ctDNA之间具有较强的作用,配合物主要以插入方式与DNA结合,二者的键合常数为1.9×105 L·mol-1。该研究结果提示染料木素铬(Ⅲ)配合物有望作为抗癌活性候选药物,值得进一步深入研究。     

邻菲啰啉和水杨酸构筑铜配合物的电化学行为及与DNA的相互作用

合成了一种新型的三元铜配合物[Cu(phen)(SA)_2]·H_2O(phen=1,10-邻菲啰啉,SA=水杨酸),并以鲱鱼精DNA为靶点,通过紫外吸收光谱法、循环伏安法、差分脉冲伏安法和DNA粘度滴定实验,探讨了配合物与DNA的键合方式。结果表明,SA的羧酸根离子与Cu~(2+)单齿配位,phen的两个氮原子与Cu~(2+)呈双齿配位,形成的配合物在0.489 V/0.050 V处呈现一对明显的准可逆氧化还原峰,并且中心Cu~(2+)在玻碳电极上的反应主要由扩散过程控制。配合物与DNA作用时,可观察到配合物的紫外光谱出现明显的减色效应,但是红移现象不明显,氧化还原峰的电流减小,峰电位发生正移,并且DNA的粘度随配合物的加入而增大。结论认为,配合物以嵌插方式与DNA发生作用形成1∶1的复合物,但插入程度较弱(结合常数为1.55×10~4L·mol~(-1))。     

鬼臼酰肼金属Ni(Ⅱ), Co(Ⅱ), Zn(Ⅱ)配合物与DNA分子作用机制的研究

在pH 7.08 Tris缓冲溶液中,采用粘度测定、电子吸收光谱、凝胶电泳和溴化乙锭荧光分析法研究了鬼臼酰肼(hydrazide-podophyllic,HDPP)NiⅡ, CoⅡ, ZnⅡ金属配合物与小牛胸腺DNA的作用机制,探讨了作用模式。结果发现,当加入一定量的DNA时,配合物的电子吸收光谱的最大吸收峰产生减色效应,同时,DNA也能较大程度地猝灭配合物体系的荧光强度。配合物都能引起DNA粘度的略微增加和将超螺旋DNA切割得到缺刻DNA。所有这些研究表明配合物可能与DNA发生了相互作用,其中镍和钴配合物与DNA之间主要以插入方式相结合;而锌配合物与DNA之间的结合方式为部分插入;求出了三种鬼臼酰肼金属配合物与DNA的结合常数。     

8-羟基喹啉-山梨酸稀土配合物与鲱鱼精DNA相互作用的光谱研究

合成了以山梨酸(SA)和8-羟基喹啉(Hq)为配体的Sm(Ⅲ)、Eu(Ⅲ)为中心的三元稀土配合物,研究了配合物与DNA之间的作用机制。采用红外光谱、紫外-可见吸收光谱、差热热重、元素分析和摩尔电导等方法,确定了配合物的化学组成,采用光谱法探讨了配合物与鲱鱼精DNA的作用机制。结果表明:配合物的化学组成为Sm(Hq)(SA)2和Eu(Hq)(SA)2,其最大吸收峰在加入DNA后发生减色和红移,中性红(NR)使配合物-DNA体系的吸收发生减色,伴有等色点出现。配合物的加入导致NR-DNA体系的吸收峰强度和位置发生变化。计算求得Eu(Hq)(SA)2和Sm(Hq)(SA)2分别与DNA的结合位点数为5,在20℃下,Sm(Hq)(SA)2、Eu(Hq)(SA)2与DNA的结合常数分别是2.04×104L/mol和1.09×104L/mol。2种稀土配合物都能不同程度地猝灭NR-DNA体系的荧光,表明2种稀土配合物对DNA都有较强的嵌插作用且能自发进行,结合能力为Sm(Hq)(SA)2Eu(Hq)(SA)2。     

钴(Ⅲ)的联吡啶类混配配合物的合成,表征及其与DNA键合的光谱研究

合成了两种新的钴多吡啶类混配配合物。通过元素分析 ,红外 ,紫外 ,核磁方法对其进行表征 ,应用吸收及发射光谱 ,DNA熔点技术 ,循环伏安法 ,研究了其与小牛胸腺DNA的作用。结果显示 ,混配配合物与DNA作用时 ,使紫外吸收明显减色 ,荧光显著增强 ,DNA熔点升高。循环伏安法研究表明 ,配合物仅有还原峰 ,与DNA作用后 ,还原峰电流明显下降。这些结果证明配合物与DNA存在插入结合 ,[Fe(CN) 6 ]4 - 猝灭实验也支持这一结论。峰电位有位移 ,说明配合物与DNA分子中带负电荷的磷酸基团可能存在静电结合 ,进而计算得到配合物与DNA的键合常数分别为 1 8× 10 4 ,4 37× 10 4 。     

氯唑西林钠与镧离子、DNA之间的作用研究

共沉淀法制得氯唑西林钠与镧离子的固体配合物,并对其进行了红外,荧光,核磁共振等研究,确定了该配合物的配位点并探讨了配位机理.同时进一步研究了该配合物与DNA形成三元配合物的荧光特性.研究结果发现:配合物的荧光发射峰强度随着DNA的加入而逐渐减小,而后随着DNA浓度的继续增大,发射峰又增高,说明此配合物与DNA可能是先嵌入结合,而后伴随有静电结合,配合物在DNA分子表面进行长距离自组装.研究证明所合成的配合物能够与DNA作用,可作为DNA的荧光探针.     

原子簇化合物十羰基二锰与DNA相互作用

采用紫外-可见吸收光谱、荧光光谱等对十羰基二锰簇合物与小牛胸腺DNA的作用方式进行了研究,结果发现在该簇合物存在下,DNA的紫外吸收光谱产生了明显的增色效应。荧光光谱研究表明DNA的荧光强度随着羰基锰簇合物的加入其荧光强度明显增加,说明羰基二锰簇合物与DNA之间存在着相互作用,作用方式可能为嵌插。     

新型4-氨基安替比林席夫碱的合成及对Cu2+的选择性识别

设计合成了一种新型安替比林-席夫碱衍生物M(4-氨基安替比林缩5-硝基水杨醛席夫碱),用IR、1H NMR及元素分析对其结构进行了表征。通过紫外光谱和荧光光谱研究了M对Cu2+的选择性识别作用。结果表明:M与Cu2+能够以1∶1的化学计量比形成配合物,结合常数为6.5×104L·mol-1;M和Cu2+的结合导致M在496 nm处的荧光猝灭,紫外可见吸收光谱红移,且M对Cu2+有较高的选择性,受常见离子的干扰较小。     

水杨醛缩壳寡糖-Cu配合物与鲱鱼精DNA的相互作用

采用紫外吸收光谱、荧光光谱和循环伏安法,研究了水杨醛缩壳寡糖-Cu配合物与鲱鱼精DNA的相互作用.发现DNA使得水杨醛缩壳寡糖-Cu的紫外吸收光谱呈现增色效应;水杨醛缩壳寡糖-Cu离子在电极上的反应主要由扩散过程控制,加入DNA后氧化还原峰电流急剧降低.结果表明水杨醛缩壳寡糖-Cu与DNA分子之间以静电模式而发生了相互作用.     

Spectrophotometric Study on the Binding of Two Water Soluble Schiff Base Complexes of Mn (III) with ct-DNA

In this work, binding of two water soluble Schiff base complexes: Bis sodium (5-sulfosalicylaldehyde) o- phenylendiiminato) Manganese (III) acetate (Salophen complex) and Bis sodium (5-sulfosalicylaldehyde) 1, 2 ethylendiiminato) Manganese (III) acetate (Salen complex) with calf thymus (ct) DNA were investigated by using different spectroscopic and electrometric techniques including UV-vis, Circular dichroism (CD) and fluorescence spectroscopy, viscommetry and cyclic voltammetry (CV). Both complexes have shown a hyperchromic and a small bathochromic shift in the visible region spectra. A competitive binding study showed that the enhanced emission intensity of ethidium bromide (EB) in the presence of DNA was quenched by the addition of the two Schiff base complexes indicating that they displace EB from its binding site in DNA. Moreover structural changes in the CD spectra and an increase in the CV spectra with addition of DNA were observed. The results show that both complexes bind to DNA. The binding constants have been calculated using fluorescence data for two complexes also K_b was calculated with fluorescence Scatchard plot for Salophen. Ultimately, the experimental results show that the dominant interactions are electrostatic while binding mode is surface binding then followed by hydrophobic interactions in grooves in high concentration of complexes.     

Synthesis,Spectral Characterization,DNA Binding Studies and Antimicrobial Activity of Co(II), Ni(II), Zn(II), Fe(III) and VO(IV) Complexes with 4-Aminoantipyrine Schiff Base of Ortho-Vanillin

A series of transition metal complexes of Co(II), Ni(II), Zn(II), Fe(III) and VO(IV) have been synthesized involving the Schiff base, 2,3-dimethyl-1-phenyl-4-(2-hydroxy-3-methoxy benzylideneamino)-pyrazol-5-one(L), obtained by condensation of 4-aminoantipyrine with 3-methoxy salicylaldehyde. Structural features were obtained from their FT-IR, UV–vis, NMR, ESI Mass, elemental analysis, magnetic moments, molar conductivity and thermal analysis studies. The Schiff base acts as a monovalent bidentate ligand, coordinating through the azomethine nitrogen and phenolic oxygen atom. Based on elemental and spectral studies six coordinated geometry is assigned to Co(II), Ni(II), Fe(III) and VO(IV) complexes and four coordinated geometry is assigned to Zn(II) complex. The interaction of metal complexes with Calf thymus DNA were carried out by UV–VIS titrations, fluorescence spectroscopy and viscosity measurements. The binding constants (K_b) of the complexes were determined as 5?×?10⁵ M^?1 for Co(II) complex, 1.33?×?10⁴ M^?1 for Ni(II) complex, 3.33?×?10⁵ M^?1 for Zn(II) complex, 1.25?×?10⁵ M^?1 for Fe(III) complex and 8?×?10⁵ M^?1 for VO(IV) complex. Quenching studies of the complexes indicate that these complexes strongly bind to DNA. Viscosity measurements indicate the binding mode of complexes with CT DNA by intercalation through groove. The ligand and it’s metal complexes were screened for their antimicrobial activity against bacteria. The results showed the metal complexes to be biologically active, while the ligand to be inactive.     

Deoxyribonucleic Acid and Bovine Serum Albumin Interaction with the Asymmetric Schiff Base Ligand and Its Molybdenum (VI) Complex: Multi Spectroscopic and Molecular Docking Studies

The interaction of an asymmetric Schiff base ligand derived from allylamine and 2,3-dihydroxybenzaldehyde and its molybdenum (VI) complex with deoxyribonucleic acid (DNA) and bovine serum albumin (BSA) were studied using spectroscopic and molecular docking methods. The spectroscopic results revealed that the DNA and BSA affinity for binding the Mo(VI) complex is greater than its ligand. Furthermore, the molecular docking calculations showed that H-bond, hydrophobic, π-π and π-cation interactions had the dominant roles in the stability of the compound-BSA complexes. The DNA interaction results suggested that the compounds interacted with DNA by the groove binding mechanism.     

噻吩甲酰基吡唑啉酮缩β-丙氨酸配合物的合成、表征及极谱行为

在非水溶剂中 ,β 丙氨酸与 1 苯基 3 甲基 4 (2 噻吩甲酰基 )吡唑啉酮 5反应合成新型酰基吡唑啉酮席夫碱化合物 1 苯基 3 甲基 4 (2 噻吩甲酰基 )吡唑啉酮 5缩 β 丙氨酸 (HL) .通过回流席夫碱和金属硝酸盐合成了UO2 (Ⅱ )、Cu(Ⅱ )、Co(Ⅱ )和Fe(Ⅱ )金属配合物 .在乙酸 乙酸钠 (pH =4 .6 )缓冲溶液 饱和甘汞电极体系中 ,测量电位 - 1.2 4V处 ,测得铜配合物的极谱波 .元素分析及摩尔电导值表明 ,新配合物的组成为 [UO2 L2 ]·H2 O ,[CuL2 ]·2H2 O ,[CoL2 ]·2H2 O和 [FeL2 ]·2H2 O .运用红外光谱、紫外光谱、核磁共振谱、热谱和磁矩对配合物进行了表征 .结果表明 ,配合物的中心离子 (除UO2 2 + 以外 )均为 6配位 .铜配合物的Cu2 + 还原产生峰电流 ,其电极反应转移 1个电子 .     

Synthesis,Characterization, DNA Binding Properties and Antioxidant Activity of Ln(III) Complexes with Schiff Base Ligand Derived from 3-Carbaldehyde Chromone and Aminophenazone

A novel Schiff base ligand, chromone-3-carbaldehyde-aminophenazone (L) and its Ln(III) (Ln = La, Yb) complexes were synthesized and characterized by physicochemical methods. The interaction between the ligand, Ln(III) complexes and calf thymus DNA in physiological buffer (pH = 7.10) was investigated by using UV–vis spectroscopy, fluorescence spectra, ethidium bromide experiments and viscosity measurements, indicating that the studied compounds can all bind to DNA via an intercalation binding mode and the complexes have stronger binding affinity than the free ligand alone. Furthermore, antioxidant activity of the ligand and its complexes was determined by superoxide and hydroxyl radical scavenging methods in vitro, suggesting that Ln(III) complexes inhibit stronger antioxidant activity than the ligand alone and some standard antioxidants, such as mannitol and vitamin C.     

三种席夫碱化合物对DNA作用的表面增强拉曼光谱研究

用表面增强拉曼光谱研究了三种Ｄ－氨基葡萄糖水杨醛席夫碱化合物以及它们对ＤＮＡ的作用情况,探讨了它们在银胶上的吸附模式和与ＤＮＡ的作用方式,比较了它们之间的差别。     

Research on the interaction of cr(III) complex of genistein with DNA

The interaction of the Cr(III) complex of genistein (GEN-Cr) with calf thymus DNA (ctDNA) in Tris (pH 7.2) buffer was investigated using UV spectra, DNA melting, fluorescence spectra and viscosity. From the absorption titration experiment, no obvious red shift was found, but the notable hypochromicities were observed. When C(DNA)/C(GEN-Cr) = 3, the pi-pi* transitions of the complex at 272 nm showed a decrease in intensity of 29.1%, which indicated that there was remarkable intercalation between complex and DNA base pairs, involving a strong pi-stacking interacting between them. The binding constant for the complex was K = 1.9 x 10(5) mol x L(-1). From the melting curves of ctDNA in the absence and presence of the complex, the melting temperature of ctDNA was found to increase by 5.5 degrees C from 74 to 79.5 degrees C, owing to the increased stability of the helix in the presence of the complex that was intercalated into the double helix. The complex could emit weak luminescence in Tris buffer. The emission intensity of the complex at 340 nm increased steadily with the addition of ctDNA. The result suggested that the complex got into a hydrophobic environment inside the DNA and avoided the effect of solvent water molecules. The strong interaction of the complex and ctDNA also resulted in greatly enhanced intensity of the resonance light scattering spectra. The emission intensity of DNA-EB system at 600 nm decreased remarkably with increasing the complex concentration, which indicated that the complex could be intercalated into DNA and replace EB from the DNA-EB system. According to the classical Stern-Volmer equation, the quenching plots at 25 and 37 degrees C both appeared approximately linear. These results showed that there was one predominant quenching style in this process. Viscosity experiments were carried out by an Ubbelodhe viscometer at 20.0 (+/- 0.1) degrees C. The relative viscosity of ctDNA increased steadily with the increased in the complex. The result clearly showed that the complex could be intercalated between DNA base pairs, causing an extension of the helix, and thus increased the viscosity of DNA. The results above indicated that there is a relatively strong interaction between the GEN-Cr complex and ctDNA, and the complex could bind ctDNA mainly by intercalation. The research suggested that the GEN-Cr complex may be a promising candidate for anticancer, which deserves further research.