白蛋白希夫碱配合物结合体清除自由基性能的研究

以水溶性生物高分子牛血清白蛋白(BSA)为载体,与小分子N-4-羟基水杨醛缩苯丙氨酸希夫碱金属配合物(HOSalpheM)结合,制得水溶性生物高分子金属配合物结合体(BSA-HOSalpheM,M=Co、Mn、Zn、Cu、Fe)。采用FT-IR、UV-Vis、CD和Native-PAGE电泳对其结构进行了表征和分析。采用NBT光化学还原法考察了BSA-HOSalpheM清除羟基自由基(·OH)的活性。结果表明:HOSalpheM具有一定的抗·OH活性,与生物高分子结合后,结合体BSA-HOSalpheM具有良好的水溶性和·OH清除能力。     

金属卟啉白蛋白结合体模拟SOD酶性能研究

将两类水难溶性金属卟啉(MP),meso-四苯基卟啉金属配合物(MTPP,M=ZnII,CoII)和meso-四(p-羟基苯基)卟啉金属配合物(MTpHPP,M=ZnII,CoII)分别与牛血清白蛋白(BSA)结合,制得水溶性金属卟啉白蛋白结合体(MP@BSA).采用UV-vis光谱、聚丙烯酰胺凝胶电泳(PAGE)、圆二色谱进行了表征与分析,发现金属卟啉的水溶性和稳定性得到大幅度提高.采用NBT光还原法测定了MP@BSA结合体清除超氧阴离子自由基(O2·-)的能力,发现结合体MP@BSA具有清除O2·-的性能,与小分子金属卟啉相比,结合体的抗O2·-性能提高了一个数量级.MP@BSA抗氧化活性分别是VC和BSA的600倍和40倍.其中,羟基取代金属卟啉结合体表现出更强的清除O2·-的活性,CoTpHPP@BSA的EC50为1.5μmol/L,对天然Cu,Zn-SOD的模拟度为2.73%.最后提出了生物高分子结合体清除O2·-的可能机理.     

低聚壳聚糖及其金属配合物的抗O·-2活性研究

以NBT/VB2/蛋氨酸为O*-2产生、检测体系,对自制低聚壳聚糖及其金属配合物进行了抗O*-2活性研究,结果显示低聚壳聚糖及其金属配合物对O*-2均具有明显的清除活性.质量浓度为0.5×10-2 g/mL时,壳聚糖对O*-2的清除率达80.3%,其与氯化镧、醋酸铜、醋酸钴的配合物对O*-2的清除率分别为98.9%、84.1%、78.4%;相同条件下,高分子壳聚糖和单糖对O*-2没有明显的清除作用,清除率仅为13%、9.5%.随着样品质量浓度降低,低聚壳聚糖及其金属配合物的清除活性逐渐下降.     

壳聚糖希夫碱钴配合物的合成及抗羟基自由基活性

以水溶性低聚壳聚糖为原料,经水杨醛、香草醛、2,4-二羟基苯甲醛修饰后制得了三种低聚壳聚糖希夫碱钴配合物CS-Sal-Co、CS-Val-Co和CS-Dh-Co,采用FT-IR和ICP对其结构和金属含量进行了分析。首次采用BPR-硫脲催化光度法测定了三种钴配合物的抗.OH活性。结果表明:CS-Sal-Co对.OH的清除效果最好,清除率可达到95.41%;CS-Val-Co对.OH的清除作用较弱,清除率最大为46.77%;CS-Dh-Co对.OH清除率最大为58.50%。探讨了壳聚糖希夫碱钴配合物清除.OH的机理。     

角蛋白金属结合体的制备及清除超氧阴离子自由基性能

本文在制备可溶性羽毛角蛋白溶液的基础上,制备了羽毛角蛋白(FK)结合ZnII、CuII、MnII和NiII的角蛋白金属结合体(FKM,M=Zn,Cu,Mn,Ni)。采用IR、UV-Vis、TGA、CD和SEM等对其结构进行了表征和分析。用核黄素/蛋氨酸-NBT还原法考察了角蛋白金属结合体FKM清除超氧阴离子自由基(O2-)的性能,探讨了其清除机理。结果表明:含不同金属离子的结合体均具有清除O2-的能力。其中,Cu结合体的抗氧化活性最强。     

低聚壳聚糖及其金属配合物的抗O_2~(·-)活性研究

以 NBT/VB2 /蛋氨酸为 O· - 2 产生、检测体系 ,对自制低聚壳聚糖及其金属配合物进行了抗 O· - 2 活性研究 ,结果显示低聚壳聚糖及其金属配合物对 O· - 2 均具有明显的清除活性 .质量浓度为 0 .5× 1 0 - 2 g/m L时 ,壳聚糖对 O· - 2 的清除率达 80 .3 % ,其与氯化镧、醋酸铜、醋酸钴的配合物对 O· - 2 的清除率分别为98.9%、84.1 %、78.4% ;相同条件下 ,高分子壳聚糖和单糖对 O· - 2 没有明显的清除作用 ,清除率仅为 1 3 %、9.5 % .随着样品质量浓度降低 ,低聚壳聚糖及其金属配合物的清除活性逐渐下降     

高分子希夫碱金属配合物的研究进展 (Ⅰ)高分子担载希夫碱金属配合物的制备与性能

综述了近十几年来有关高分子担载希夫碱金属配合物的研究进展。此类配合物所采用的合成方法主要有：（ａ）含乙烯侧基的配体或金属配合物共聚；（ｂ）小分子配体或配合物锚连于高分子载体。其主要性能为结合分子氧和催化活性。     

高分子希夫碱金属配合物的研究进展：（I）高分子担载希夫碱金属配合物？…

综述了近十几年来有关高分子担载希夫碱金属配合物的研究进展。此类配合物所采用的合成方法主要有：（ａ）含乙烯侧基的配体或金属配合物共聚；（ｂ）小分子配体或配合物锚连于高分子载体。其主要性能为结合分子氧和催化活性。     

邻香草醛缩天冬氨酸铜、锌、钴、镍配合物的合成

氨基酸希夫碱是具有多种配位原子和生物、化学活性的配体,其过渡金属配合物对生物无机化学和医药有重要意义［１～３］,我们曾报道过某些氨基酸希夫碱及其配合物的抗Ｏ－·２性能［４,５］．本文合成了邻香草醛缩天冬氨酸铜、锌、钴、镍配合物并进行了系列表征,提出其...     

N(—2-羟基乙基)—水杨醛亚胺稀土配合物的合成与性质研究

J.J.Calienni等以水杨醛及取代水杨醛与取代氨基乙醇反应制得多种希夫碱,并合成了它们与铕的希夫碱配合物。N-(2-羟基乙基)-水杨醛亚胺(HESI)与Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)和Zn(Ⅱ)配合物的合成和抗癌活性的研究也有报道,但该希夫碱稀土配合物尚未见文献报道。鉴于有些稀土化合物具有消炎、抗癌活性,合成稀土希夫碱配     

Antioxidant activity of bovine serum albumin binding amino acid Schiff-bases metal complexes

Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin (BSA),which afforded BSA binding Schiff-base metal complexes (BSA-SalGluM,M=Cu,Co,Ni,Zn).The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE.It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes.The effect of the antioxidant activity was investigated.The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes.     

Synthesis and DNA binding studies of Ni(II), Co(II), Cu(II) and Zn(II) metal complexes of N1,N5-bis[pyridine-2-methylene]-thiocarbohydrazone Schiff-base ligand

The thiocarbohydrazone Schiff-base ligand with a nitrogen and sulphur donor was synthesized through condensation of pyridine-2-carbaldehyde and thiocarbohydrazide. Schiff-base ligands have the ability to conjugate with metal salts. A series of metal complexes with a general formula [MCl2(H2L)]·nH2O (MNi, Co, Cu and Zn) were synthesized by forming complexes of the N1,N5-bis[pyridine-2-methylene]-thiocarbohydrazone (H2L) Schiff-base ligand. These metal complexes and ligand were characterized by using ultraviolet-visible (UV-Vis), Fourier Transform Infrared (FT-IR), 1H and 13C NMR spectroscopy and mass spectroscopy, physicochemical characterization, CHNS and conductivity. The biological activity of the synthesized ligand was investigated by using Escherichia coli DNA as target. The DNA interaction of the synthesized ligand and complexes on E. coli plasmid DNA was investigated in the aqueous medium by UV-Vis spectroscopy and the binding constant (Kb) was calculated. The DNA binding studies showed that the metal complexes had an improved interaction due to trans-geometrical isomers of the complexes than ligand isomers in cis-positions.     

左氧氟沙星铜(Ⅱ)配合物的合成及生物活性研究

合成了四个新左氧氟沙星铜(Ⅱ)配合物:[Cu(Lvfx)(Bipy)(H2O)]Cl.4H2O(1),[Cu(Lvfx)(Phen)(H2O)]Cl.5H2O(2),[Cu(Lvfx)(Tatp)(H2O)]Cl.5H2O(3),[Cu(Lvfx)(Dppz)(H2O)]Cl.4.5H2O(4){Lvfx=左氧氟沙星,Bipy=2,2’-联吡啶,Phen=1,10-邻菲罗啉,Tatp=1,4,8,9-四氮三联苯,Dppz=二吡啶并[3,2-a:2’,3’-c]吩嗪},并通过红外光谱法、紫外-可见光谱法、元素分析、原子吸收光谱法、摩尔电导率分析和差热-热重分析对配合物进行了表征。用滤纸片扩散法和试管二倍稀释法分别测试了配合物及配体对大肠杆菌、金黄色葡萄球菌的抗菌活性,结果显示配合物(3)对大肠杆菌具有最佳的抑菌效果。采用荧光光谱法初步研究了配合物与BSA的相互作用。结果表明,四个配合物均对BSA的荧光有较强的猝灭作用,且发生了能量转移,其与BSA的结合常数(K)分别为4.7×102、5.7×103、5.0×103和1.7×103L.mol-1,结合位点n分别为0.59、0.83、0.81和0.69。     

没食子酸丙酯Fe(Ⅲ)、Cr(Ⅲ)、Cu(Ⅱ)配合物的合成、表征及模拟超氧化物歧化酶

研究了没食子酸丙酯在水溶液中分别与Fe3+、Cr3+、Cu2+生成没食子酸丙酯-铁(PG-Fe)、没食子酸丙酯-铬(PG-Cr)、没食子酸丙酯-铜(PG-Cu)这3种金属配合物(PG-M)的反应。 通过紫外光谱、核磁共振、红外光谱、质谱、元素分析、摩尔电导率和循环伏安法等测试技术对3种金属配合物进行了表征。 确定3种金属配合物的分子式分别为[C10H10O5]2Fe·H2O、[C10H10O5]3Cr·2H2O、[C10H10O5]2Cu·2H2O。 红外光谱分析表明,中心金属原子与酚羟基发生配位,形成Ar-O-M键。 电化学数据显示,PG-M的抗氧化性优于PG配体,且PG-Cu＞PG-Cr＞PG-Fe。 用改进的核黄素光还原NBT法检测了3种金属配合物的模拟超氧化物歧化酶(SOD)活性。 结果表明,3种金属配合物均有一定的催化歧化超氧阴离子自由基(O-2·)活性,均可被称作超氧化物歧化酶活性中心的模拟配合物。     

一种含磷三足体衍生物及其铕配合物的合成及性能表征

设计合成了一种新型含磷的水溶性三足体衍生物[L:N-二(吡啶-二氨基乙酰基)甲基磷酸]及其Eu(Ⅲ)的配合物,用红外吸收光谱、元素分析、差热-热重和紫外光谱法等技术手段对该配合物进行了表征,用荧光光谱法研究了室温下该配合物和牛血清白蛋白(BSA)的相互作用。 结果表明,配体与苦味酸铕形成1:1型配合物Eu(pic)₃L;配合物与BSA之间有很强的结合作用;配合物对BSA内源荧光的猝灭方式为静态猝灭;配合物与BSA的作用力为分子间氢键和范德华力。 分别考察了Fe³⁺和Cu²⁺对配合物与BSA结合作用的影响,证明Fe³⁺和Cu²⁺能够以金属离子桥键与配合物结合使配合物-BSA的稳定性增强。 根据Foster型偶极-偶极无辐射能量转移机理可知,配合物可以和BSA以偶极-偶极无辐射进行能量传递。     

Synthesis and spectral characterization of Schiff-base complexes derived from alanine and 2-acetylpyridine with some divalent metal acetates

Schiff-base complexes [ML(H₂O)₂(Ac)]nH₂O (M?=?Co(II), Ni(II) and Zn(II); L?=?Schiff-base ligand derived from 2-acetylpyridine and alanine and n?=?1–3/2) were synthesized and characterized by elemental analysis, spectral (FTIR, UV/Vis, MS, ¹H-NMR), thermal (TGA), conductance and magnetic moment measurements. The results suggest octahedral geometry for all the isolated complexes. IR spectra show that the ligand coordinates to the metal ions as mononegative tridentate through pyridyl nitrogen, azomethine nitrogen and carboxylate oxygen after deprotonation of the hydroxyl group. Semi-empirical calculations PM3 and AM1 have been used to study the molecular geometry and the harmonic vibrational spectra to assist the experimental assignments of the complexes.     

Interactions between metal ions and carbohydrates. Spectroscopic characterization and the topology coordination behavior of erythritol with trivalent lanthanide ions

The coordination of carbohydrate to metal ions is important because it may be involved in many biochemical processes. The synthesis and characterization of several novel lanthanide-erythritol complexes (TbCl(3)·1.5C(4)H(10)O(4)·H(2)O (TbE(I)), Pr(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (PrEN), Ce(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (CeEN), Y(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (YEN), Gd(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (GdEN)) and Tb(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (TbEN) are reported. The structures of these complexes in the solid state have been determined by X-ray diffraction. Erythritol is used as two bidentate ligands or as three hydroxyl group donor in these complexes. FTIR spectra indicate that two kinds of structures, with water and without water involved in the coordination sphere, were observed for lanthanide nitrate-erythritol complexes. FIR and THz spectra show the formation of metal ion-erythritol complexes. Luminescence spectra of Tb-erythritol complexes have the characteristics of the Tb ion.     

Synthesis,structure, and DNA binding of three reduced amino-acid Schiff-base zinc(II), nickel(II), and cadmium(II) complexes

Three new reduced amino-acid Schiff-base complexes, [Zn(HL)₂] · H₂O (1), [Ni(HL)₂] · H₂O (2), and [Cd(HL)₂] · H₂O (3), where H₂L is a reduced Schiff base derived from condensation of N-(2-hydroxybenzaldehyde) and L-histidine, have been synthesized and characterized by elemental analysis, UV-Vis absorption spectra and single crystal X-ray diffraction. Complexes 1–3 are isostructural. All metal centers are six-coordinate with O₂N₄ donor sets in slightly distorted octahedra. Unlike its Schiff-base counterpart, the deprotonated monoanionic ligand HL^? has a more flexible backbone and two HL^? are tridentate to one metal. Moreover, the binding interactions of these complexes with calf thymus DNA (CT-DNA) have been investigated by UV-Vis spectra and fluorescence quenching, which show that the complexes bind in an intercalative mode.     

Engineering of highly luminescent lanthanide tags suitable for protein labeling and time-resolved luminescence imaging

The synthesis of a new ligand LH(4) based on a glutamic acid skeleton bis-functionalized on its nitrogen atom by 6-methylene-6'-carboxy-2,2'-bipyridine chromophoric units is described. UV-vis spectrophotometric titrations revealed the formation of 1:1 M:L complexes with lanthanide(III) cations, and complexation of LH(4) with equimolar amounts of hydrated LnCl(3) salts (Ln = Eu, Gd, and Tb) gave water-soluble and stable complexes of the general formula [LnL(H(2)O)]Na, which were characterized by elemental analysis, IR, UV-vis absorption spectroscopy, (1)H NMR (Ln = Eu), and mass spectrometry. The conditional stability constant for formation of the [EuL(H(2)O)]Na complex was determined by competitive complexation experiments to be log K = 16.5 +/- 0.6 in 0.01 M TRIS/HCl buffer (pH = 7.0). In water solution, the [EuL(H(2)O)]Na and [TbL(H(2)O)]Na complexes were highly luminescent with quantum yields of 8% and 31%, respectively, despite the presence of ca. one water molecule in the first coordination sphere of the metal ions. Activation of the appended carboxylate function of the glutamate moiety in the form of an N-hydroxysuccinimidyl ester allows for the covalent linking of the complexes to primary amino groups of biological compounds. Bovine serum albumin (BSA) was labeled with both Eu or Tb complexes, and the Ln-BSA conjugates were characterized by UV-vis absorption and emission spectroscopy and MALDI-TOF mass spectrometry. Labeling ratios (number of complex molecules per BSA) of ca. 8:1 and 7:1 were established for Eu-BSA and Tb-BSA, respectively. The suitability of the tagged compound for use in bioanalytical time-resolved luminescence microscopy was established by comparison with fluorescein-labeled probes.     

Co(II), Ni(II) and Cu(II) complexes with coumarin-8-yl Schiff-bases: spectroscopic, in vitro antimicrobial, DNA cleavage and fluorescence studies

A new series of Co(II), Ni(II) and Cu(II) complexes of the type ML·2H2O of Schiff-bases derived from m-substituted thiosemicarbazides and 8-acetyl-7-hydroxy-4-methylcoumarin have been synthesized and characterized by spectroscopic studies. Schiff-bases exhibit thiol-thione tautomerism wherein sulphur plays an important role in the coordination. The coordination possibility of the Schiff-bases towards metal ions have been proposed in the light of elemental analyses, spectral (IR, UV-vis, FAB-mass, ESR and fluorescence), magnetic and thermal studies. The low molar conductance values in DMF indicate that, the metal complexes are non-electrolytes. The cyclic voltammetric studies suggested that, the Cu(II) and Ni(II) complexes are of single electron transfer quasi-reversible nature. The Schiff-bases and its metal complexes have been evaluated for their in vitro antibacterial (Escherichia coli, Staphilococcus aureus, Bascillus subtilis and Salmonella typhi) and antifungal activities (Candida albicans, Cladosporium and Aspergillus niger) by MIC method. The Schiff-base I and its metal complexes exhibited DNA cleavage activity on isolated DNA of A. niger.