染料木素金属配合物的抗氧化活性研究

以染料木素化合物为配体与铜、锌金属离子配位,合成出染料木素过渡金属配合物。利用红外、紫外光谱、元素分析及摩尔电导等方法,对染料木素及其配合物进行了结构表征。此外,对配体及其金属配合物进行了抗氧化能力的测定。结果表明:金属离子与染料木素配体的协同作用可提高其抗氧化活性的能力。     

杯芳烃配位性质的研究进展

杯芳烃及其衍生物由于其结构的特殊性,几乎可以与所有的金属离子形成配合物。本文主要综述了其对碱金属及碱土金属、过渡金属及镧系锕系金属的配合作用,并对其应用前景进行了展望。     

槲皮素金属配合物及其抗肿瘤作用研究进展

槲皮素是一种具有广泛药理活性的天然独特分子结构的槲皮素多酚类黄酮,对多种肿瘤具有预防和治疗作用,是多种金属离子的良好螯合配体。研究表明,槲皮素与金属离子配合,能显著提高其抗氧化和抗肿瘤等作用,降低其金属毒性。综述了近10年合成的具有抗肿瘤活性的槲皮素金属配合物及其抗肿瘤作用机制,为槲皮素金属配合物开发成为预防与治疗癌症的药物提供理论参考。     

金属离子(Na+、K+、Mg2+、Ca2+)与鸟嘌呤活性位点相互作用的理论研究

本文用量子化学从头算方法对金属离子与碱基活性位点的相互作用及其形成配合物的结构和性质进行理论研究.用HF/6-311G*优化鸟嘌呤及其金属离子(Na 、K 、Mg2 、Ca2 )配合物.在HF水平上,运用6-311G*基组计算Ⅰa和Ⅱa族金属离子(Na 、K 、Mg2 、Ca2 )与鸟嘌吟(Guanine)活性位点的相互作用.结果表明:Mg2 、Ca2 离子引起配位体的变形较Na 、K 离子大;Mg2 、Ca2 离子配合物比Na 、K 离子配合物稳定.     

一种氨基酸Schiff碱及其铜、锌配合物的合成及抑菌活性

合成了3-氨基苯甲酸缩3,5-二溴水杨醛Schiff碱配体(L)及其过渡金属(Cu,Zn)的配合物。采用UV-vis,1HNMR,IR,MS和元素分析对其进行了表征。研究了配体及配合物的热稳定性能,由热重分析得知所合成的配体及配合物均具有良好的热稳定性能。对配体及配合物进行了抑制大肠杆菌、金黄色葡萄球菌及欧文氏草生杆菌的生物活性测定,配体及配合物都表现出一定的生物活性,其中Cu配合物的活性优于Zn配合物,说明配合物的生物活性与金属离子的类型有关。     

芦丁金属配合物的研究进展

芦丁及其衍生物具有广泛的药理活性。芦丁具有完整的大π键共轭体系,强配位氧原子与合适的空间构型,可与金属离子螯合成稳定的环状配合物。到目前为止,国内外合成的芦丁金属配合物,有些具有明显的生物活性,有些药理作用显著。芦丁与金属离子在一定条件下形成配合物后,还可应用于分光光度、荧光、极谱分析等,检测金属离子或者检测芦丁的含量。     

5-氯水杨醛缩甘氨酸与过渡金属离子配合物的合成及性质研究

合成了5-氯水杨醛缩甘氨酸Schiff碱配体及其三种金属离子(Ni2+、Cu2+、Co2+)的Schif碱配合物.用熔点、红外光谱、紫外-可见光谱、电导率等方法对配体及配合物的组成、结构、性质进行了研究,并检测了其抑菌活性.     

乙酰基甲酰苯胺缩氨基脲Schif碱配合物的合成及表征

合成了乙酰基甲酰苯胺缩氨基脲Ｓｃｈｉｆ碱及其与某些过渡金属离子的配合物。对产物进行了元素分析和红外光谱的解析。对其抗菌活性作了初步的研究     

水杨醛缩氨基硫脲配合物与牛血清蛋白的弱相互作用研究

本文合成了水杨醛缩氨基硫脲席夫碱配体并与锰、镉金属离子进行配位反应,合成了两种配合物。并通过红外光谱图分析,对配体及配合物的做了表征,分析了配合物可能存在的结构。选用荧光光谱法对席夫碱及其配合物和牛血清蛋白的弱相互作用进行了研究分析,结果表明该配体及其金属配合物与牛血清蛋白形成了基态复合物,引起了牛血清蛋白内源荧光猝灭现象,而具体何种荧光猝灭还有待进一步研究。     

乙酰基甲酰苯胺缩氨基脲Schiff碱配合物的合成及表征

合成了乙酰基甲酰胺缩氨基脲Ｓｃｈｉｆｆ碱及其与某些有过渡金属离子配合物，对产物进行了元素分析和红外光谱的解析，对其抗菌活性作了初步的研究。     

Cationic Peptides and Their Cu(II) and Ni(II) Complexes: Coordination and Biological Characteristics

Antimicrobial peptides are a promising group of compounds used for the treatment of infections. In some cases, metal ions are essential to activate these molecules. Examples of metalloantibiotics are, for instance, bleomycin and dermcidin. This study is focused on three new pseudopeptides with potential biological activity. The coordination behavior of all ligands with Cu(II) and Ni(II) ions has been examined. Various analytical methods such as potentiometric titration, UV-Vis and CD spectroscopies, and mass spectrometry were used. All compounds are convenient chelators for metal ion-binding. Two of the ligands tested have histidine residues. Surprisingly, imidazole nitrogen is not involved in the coordination of the metal ion. The N-terminal amino group, Dab side chains, and amide nitrogen atoms of the peptide bonds coordinated Cu(II) and Ni(II) in all the complexes formed. The cytotoxicity of three pseudopeptides and their complexes was evaluated. Moreover, their other model allowed for assessing the attenuation of LPS-induced cytotoxicity and anti-inflammatory activities were also evaluated, the results of which revealed to be very promising.     

生物基材料去除废水中重金属离子的研究综述

如何有效地去除水中的重金属离子的方法已成为当前水处理领域的研究热点。与其他各种处理材料相比较,生物基材料具有可生物降解、原料可再生和环境友好等特性,因而在去除重金属离子方面具有天然的优势。该文综述了典型生物基材料的结构特征及其在去除重金属离子方面的应用,分析了生物基材料处理重金属离子选择性好、去除率高的原因,原因在于生物基材料含有易与金属离子形成特定的络合结构,形成独特的金属配位化合物具有较高的立体选择性;着重探讨了生物基材料的不同改性方法、机理及必要性,展望了生物基材料研究的未来发展方向及前景。     

络合重金属废水处理的研究进展

络合重金属废水中含有的污染物不可生物降解,具有很强的毒性,可通过食物链在生物体内的累积而致癌。与游离态的重金属离子相比,络合态的重金属离子的去除难度更大,普通的加碱中和沉淀法难以获得满意的处理效果。综述了近年来处理络合重金属废水的主要方法,包括硫化物沉淀法、螯合沉淀法、Fenton氧化法、光催化氧化法、铁屑还原法、吸附法、离子交换法等,并且评价了它们的优势和局限性。     

Ion-Exchange Method for Fabricating High-Silica Glasses

Porous glasses produced by phase separation and leaching are used as substrates for the exchange of metal cations from a basic solution for the protons of silicon-bonded hydroxyl ions on the pore surfaces and on residual silica gel present in the pores. This method yields extremely homogeneous, fully dense high-silica glasses with low to moderate concentrations of metal dopants after sintering to collapse the pores. The quantity and rate of ion exchange are studied as a function of time, solution pH, and solution ion concentration for various dopant salts. In addition, a double ion-exchange method is described whereby, during the second exchange, ions which have a relatively low solubility in basic solutions can be exchanged from a neutral or acidic solution onto the glass surface.     

卤化银乳剂制备中的新型掺杂剂

本文综述了近年来乳剂制备中常用的新型掺杂剂 ,较详细地介绍了两种能提高光电子利用效率的掺杂剂 ,即过渡金属络合物浅电子陷阱掺杂剂和羧酸盐(酯 )有机空穴陷阱掺杂剂 ,总结了掺杂剂的选择原则 ,并举例说明了掺杂剂对乳剂感光度的影响 .     

掺杂型金属氧化物半导体材料的研究进展

金属氧化物是由金属阳离子和氧阴离子组成的一类离子型化合物,其金属正离子和氧负离子通过离子键合排布成各种不同的晶体结构而表现出独特的物理性质。然而,因其宽的能带间隙、低的光量子产率和光电转换效率、大的光生电子和空穴复合几率、低的气体响应速度、来自价带和导带消极的电子传递性能等缺陷限制了金属氧化物的应用潜力。综述了几种典型的掺杂型金属氧化物氧化锌、二氧化钛、三氧化二铁和稀土氧化物的研究进展,分析了金属掺杂对这几种典型金属氧化物在光、电、磁、传感性能方面的影响,并介绍了它们潜在的应用领域及研究现状,提出了未来的发展方向及需要关注的主题。     

Adsorbed metal ions as stabilizers for the thermal degradation of polyacrylamide

The thermal degradation of polyacrylamide has been studied in the presence of various metal ions using thermogravimetry. The thermal decomposition of the polymer in general occurs at higher temperatures in the presence of metal ions than with the pure polymer. Empirical measures of the stabilizing effect of the metal ions have been made by determining the temperatures of 12% and 50% decomposition, and the integral procedural decomposition temperature (IPDT). For main group metal ions, the stabilizing effect, as measured by the difference in ipdt between polymer-metal complex and copolymer, was inversely proportional to the radius of the metal ion, suggesting that the strength of the complex between the ion and polymer is important in determining stability. Transition metal ions, in contrast, showed no simple dependence of stabilizing effect on ionic radius, but showed, instead, a dependence upon the ligand field stabilization energy.     

Effect of Dopants on Zirconia Stabilization—An X-ray Absorption Study: I, Trivalent Dopants

Local atomic structures of Zr and dopant cations in zirconia solid solutions with Fe₂O₃, Ga₂O₃, Y₂O₃, and Gd₂O₃ have been determined. The Zr ions in both partially stabilized tetragonal and fully stabilized cubic zirconia have their own characteristic structures which are dopant-independent. The dopant cations substitute for Zr ions despite severe local distortions necessitated by the large difference in dopant–O distance ana Zr─O distance. Dopant ionic size determines the preferred locations of oxygen vacancies. Vacancies introduced by oversized dopants (Y and Gd) are located as nearest neighbors to Zr atoms, leaving 8-fold oxygen coordination to dopant cations. Undersized dopants (Fe and Ga) compete with Zr ions for the oxygen vacancies in zirconia, resulting in 6-fold oxygen coordination and a large disturbance to the surrounding next nearest neighbors. Since oxygen vacancies associated with Zr can provide stability for tetragonal and cubic zirconia, these results suggest an explanation for the observation that oversized trivalent dopants are more effective than undersized trivalent dopants in stabilizing cubic and tetragonal phases.     

Chelating polymers derived from polyvinyl alcohol and cellulose

Hydrophilic chelating polymers have been prepared by the reaction of organic compounds containing both a reactive halogen and a chelating function, with cellulose and, more especially, polyvinyl alcohol or their alkali metal derivatives. Suitable organic compounds used to illustrate the general reaction included: 5-chloromethyl-8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline, ethyl γ-chloroacetoacetate and chloromethyl-kojic acid. Subsequent reaction of the kojic acid-polyvinyl alcohol polymer with diazotised o-arsanilic acid to give a polymer containing the azo-phenylarsonic acid group indicates further scope for these materials. Preliminary tests have shown that the polymers remove metal ions from aqueous solutions. Degradation occurred, however, when the polymers were regenerated with acids to elute adsorbed metal ions.     

In Vitro Degradation and Conversion of Melt‐Derived Microfibrous Borate (13‐93B3) Bioactive Glass Doped with Metal Ions

Microfibrous melt‐derived bioactive glasses based on a borate 13‐93B3 composition are showing a considerable capacity to heal chronic soft tissue wounds in humans and animals. Metal ion dopants in borate 13‐93B3 microfibers can be beneficial for healing soft tissue wounds and bone defects but their role and delivery have received little attention. In this study, the effect of selected metal ion dopants on the degradation and conversion of 13‐93B3 microfibers in simulated body fluid at 37°C was investigated. Two groups of microfibers (diameter = 0.2–3 μm) composed of 13‐93B3 glass (composition 6 Na₂O, 12 K₂O, 5 MgO, 20 CaO, 4 P₂O₅, 53 B₂O₃, wt%) doped with (1) CuO (0.4 wt%) + ZnO (1.0 wt%); and (2) CuO (0.4 wt%) + ZnO (1.0 wt%) + Fe₂O₃ (0.4 wt%) + SrO (2.0 wt%) were studied. The metal ion dopants had little effect on the degradation of the parent 13‐93B3 glass microfibers and their conversion to an amorphous calcium phosphate (ACP) product but they inhibited the crystallization of the ACP to HA. The release of Cu and Sr ions from the glass into the medium was considerably higher than Zn and Fe ions which were retained mainly in the ACP or HA product. These results are pertinent to the design of borate bioactive glasses for optimum healing of soft tissue wounds and bone.