壳聚糖/羧甲基壳聚糖金属配合物对氧自由基的清除作用研究

以NADH-PMS-NBT体系产生超氧阴离子自由基(o2-·)和EDTANa2·Fe(Ⅱ)-H2O2体系产生 羟自由基(·OH)来研究壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合物、羧甲基壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合物时氧自由基的 清除作用。结果显示配合物对O2-·和·OH均具有明显的清除作用,其中铜(Ⅱ)配合物对O2-·的清除活 性最高,而锌(Ⅱ)配合物比铜(Ⅱ)配合物具有更强的清除·OH的能力,羧甲基壳聚糖Cu(Ⅱ)、Zn(Ⅱ)配合 物与含有相同金属离子的壳聚糖配合物相比对O2-·和·OH具有更高的抑制活性。     

组氨酸钴氧合配合物二聚体形态的电喷雾串联质谱验证研究

电喷雾质谱(ESI-MS)是一种软电离质谱技术,已在配合物的结构和机理的研究中显示了重要的作用。本文根据组氨酸钴(CoL2)(L=组氨酸)对分子氧活性很高,极易生成双核氧合配合物(CoL2-O2-CoL2)的特点,采用ESI-MS方法研究了组氨酸钴氧合物(CoL2-O2-CoL2)和组氨酸配合物ML2(M=Cu、Zn)。结果发现,质谱图中在相应于双核氧合配合物的高质荷比端(m/z>ML2),CoL2出现质谱峰,而组氨酸配合物ML2(M=Cu、Zn)在质谱图中高质荷比端没有出现质谱峰,只有配合物ML2的相关峰;这个结果证明了文献报道中的双核氧合配合物(CoL2-O2-CoL2)的存在,根据所得质谱结果,初步研究了组氨酸钴双核氧合配合物和ML2配合物的裂解规律。结果表明,可根据质谱数据中有无二聚体形态,做出Co配合物有无吸氧性能的初步判断,因此电喷雾质谱(ESI-MS)可做为研究Co配合物氧合反应和表征Co氧合配合物的有效分析手段。     

酰基吡唑啉酮配合物的合成、结构、量化计算及生物活性

在溶液中合成了1－苯基－3－甲基－4－苯甲酰基－吡唑啉酮－5（HPMBP）的Co(Ⅱ）、Ni（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）配合物,对配合物进行了元素分析和红外光谱表征。用X射线衍射方法测定了Zn(Ⅱ）配合物的晶体结构,用密度泛函方法对Co(Ⅱ）及Zn（Ⅱ）配合物进行了量子化计算,生物活性实验表明四种配合物对大肠杆菌和金黄色葡萄球菌均有一定的抗菌作用。     

含草酰胺桥的Cu(Ⅱ)-Fe(Ⅱ)和Cu(Ⅱ)-Zn(Ⅱ)双核配合物的合成、磁性及生物活性

以N,N'-双（3－氨基－2,2－二甲基丙基）草酰胺根阴离子（Me2oxpn)为桥联配体,分别端接N,N,N',N'-四甲基乙二胺（tmen)和2,9－二甲基－1,10－邻菲甲啉（Me2-phen);合成和表征了3种新的异双核配合和物[Cu(Me2oxpn)Fe(tmen)2]SO4(a),[Cu(Me2oxpn)Zn(tmen)2]SO4(b)和[Cu(Me2oxpn)Zn(Me2-phen)2]SO4(c)。经元素分析、红外光谱、电子光谱、电导及磁性测量等方法推定了这些配合物的结构。测定并研究了（a)的变温磁化率（4－300K）,求得交换参数J＝－12．96cm^-1,表明双核配合物中Cu(Ⅱ）-Fe(Ⅱ)离子间存在反铁磁超交换作用。测试了3个双核配合物的杀菌作用。     

4-[(N-甲基-N-羟乙基)氨基]苯甲醛缩氨基硫脲及其过渡金属配合物的合成及表征

本文报道了4－[(N－甲基－N－羟乙基）氨基]苯甲醛缩氨基硫脲（HL）及其金属配合物的合成,通过元素分析、红外光谱、紫外、核磁共振对配体和配合物进行了表征。配合物的组成为ML2（M=Ni(Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）、Cd（Ⅱ）、Pd（Ⅱ）。晶体结构分析表明配体分子中除了羟乙基偏离平面外,其余各原子几乎在一个平面上。晶体结构中存在N－H…O（N1…O1）和O－H…S氢键,形成一个二维网状结构。在与金属离子配合时,配体由硫酮式转变为硫醇式作为负一价二齿配体通过S和β-N与金属离子螯合,形成稳定的中性配合物。     

含硫希夫碱过渡金属配合物及其抗癌活性的研究Ⅴ.3-乙酰吡啶缩氨基硫脲与ZnX_2.CuX_2.NiX_2的配合物及其抗癌活性

合成和表征了3-乙酰吡啶缩氨基硫脲与Zn(Ⅱ)Cu(Ⅱ)Ni(Ⅱ)的六个配合物,并用体外试管法测试了配体和配合物的抗癌活性。结果表明:3-乙酰吡啶是通过亚胺基N原子和S原子与金属离子形成配合物,这些配合物的抗癌活性均强于自由配体,Zn(Ⅱ)和Cu(Ⅱ)配合物对腹水癌细胞的杀死率均为100%.     

Schiff碱单核及双核配合物拟酶催化性能的研究

系统地研究了新型Schiff碱单核及双核配合物在拟酶催化PhIO单加氧化环己烷反应中的催化性能.结果表明,双核配合物MnML{M=Mn(Ⅱ),Fe(Ⅲ)Cl,Cr(Ⅲ)Cl,Cu(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ);L=双[N,N'亚乙基2,2'(苯亚甲基)二(3,4二甲基吡咯5醛缩亚胺)]}的催化活性比对应的单核配合物MnH₂L与MH₂L之混合物的催化活性高.因此,我们认为在双核配合物中两金属离子间存在协同作用,并发现这种协同作用一般随双核配合物中成单d电子数增加而增大.     

3-乙基-2-乙酰吡嗪缩4-苯基氨基脲铜/锌配合物的晶体结构及荧光性质（英文）

合成了配合物[Cu(HL)(H_2O)(NO3)]NO3(1)和[Zn(HL)Cl2](2)(HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲),并通过单晶X射线衍射、元素分析及红外光谱表征了结构。单晶衍射结果表明,配合物1中,中心Cu(Ⅱ)离子与1个中性三齿缩氨基脲配体,1个水分子和1个硝酸根配位,配位构型为扭曲的四方锥。配合物2中Zn(Ⅱ)离子周围的配位原子为N2OCl2,其配位构型与配合物1中Cu(Ⅱ)离子的相同。甲醇溶液中,配合物2的荧光发射峰与配体HL相似。而配合物1由于配体和金属离子之间的能量转移,最大荧光发射峰略有红移。     

D-氨基葡萄糖、α-甘氨酸金属混配物的研究

报道了D－氨基葡萄糖，α－甘氨酸与Cu(Ⅱ),Zn(Ⅱ),Fe(Ⅲ），Co(Ⅲ),Ni(Ⅱ)形成的混配物的合成方法，通过元素分析，IR，UV－Vis,1HNMR,13CNMR等手段对配合物进行了表征。采用Pryrogallol-NBT比色法对化合物清除超氧自由基（O2－）的能力进行了测试，结果表明各配位体对超氧自由基（O2－）均有一定的清除作用。     

SOD酶模型配合物的合成及催化歧化作用——1,3,4-噻二唑类希夫碱配合物的合成、表征及对超氧离子的抑制作用

合成了2－氨基－5－巯基－1，3，4－噻二唑缩2，4－二羟基苯甲醛及其与Cu(Ⅱ），Co（Ⅱ），Zn（Ⅱ）的配合物，通过元素分析、摩尔电导、IR及其电子光谱对其组成和结构进行了表征。活性实验表明，配合物均对超氧离子有一定的抑制效果。     

聚吡咯/Gd-掺杂铜锌铁氧体复合物的制备及电/磁性能

用溶胶-凝胶法和溶液原位聚合法分别制备了Gd-掺杂纳米级Zn_0.6Cu_0.4Fe_2－xGd_xO₄ (x＝0～0.10)铁氧体粉末和聚吡咯/Zn_0.6Cu_0.4Fe_1.96Gd_0.04O₄纳米复合物. 用现代分析技术表征了样品的结构、形貌和电磁性能. 结果表明Gd-掺杂铁氧体的饱和磁化强度随Gd含量的增加而增大; 复合物的电导率和饱和磁化强度与聚吡咯的含量有关, 当聚吡咯的含量从w＝50%增加到w＝80%, 复合物的电导率从0.0139增加到0.0423 S/cm, 而饱和磁化强度则从18.37减小到14.35 emu/g. 在8～18 GHz频段内, 吸收层厚度为2 mm时, PPy在16 GHz附近的反射损耗峰值为－19.68 dB, 有效带宽为6.2 GHz; 而ZCGFO的反射损耗峰值和有效带宽分别为－16.6 dB和5.16 GHz. 和PPy和ZCGFO相比, PPy/ZCGFO复合物有更低的反射损耗和更大的有效带宽, ZCGFO相对含量为20%的PPy/ZCGFO复合物的反射峰值和有效带宽分别达到－20.90 dB和14.05 GHz. 这些结果说明PPy/ZCCFO复合物适合作为电磁波吸收与屏蔽的候选材料.     

加料方式对CuO/ZnO/Al2O3系催化剂前驱体性质的影响

用XRD、TG-DTG、TPR技术研究了不同加料方式对CuO/ZnO/Al2O3系催化剂前驱体物相组成及其结晶情况的影响，用加压微反装置考察了催化剂合成甲醇反应活性。结果表明, 加料方式对Cu2+形成的中间化合物的物相组成及结晶度影响显著,对Zn2+及Al3+的沉淀物相的影响很小。不同加料方式对催化剂前驱体物相组成及催化剂性能的影响主要是形成的初始前驱体中Cu的物相及结晶度不同。正加法主要形成Cu2(OH)3NO3,并流法主要形成无定形Cu2CO3(OH)2,后者与Zn5(CO3)2(OH)6相互作用转化为(Cu,Zn)2CO3(OH)2和（Cu,Zn）5(CO3)2(OH)6，由它们分解形成的CuO-ZnO固溶体是合成甲醇反应的活性相。并流法能最大程度的形成CuO-ZnO固溶体，有利于CuO粒子的细化，其催化活性较好。     

苯并咪唑取代胺类及其金属配合物的研究与应用

概述了双苯并咪唑取代胺类、三苯并咪唑取代胺类及四苯并咪唑取代胺类配体及其金属配合物的研究和应用。研究报道,这些配体与人体必需的微量元素铜、锌、钴、镍、锰等金属形成的配合物能较好地模拟SOD分子中与金属离子配位的组氨酸的结构,且具有较好的拟SOD生物活性。     

Adsorption of Cu(II) on porous chitosan membranes functionalized with histidine

The ability of chitosan to form complexes with bivalent metal ions has been broadly explored in the literature. The present work investigates the influence of functionalization of macroporous chitosan membranes with histidine on their ability to remove copper ions from aqueous solution in the range of pH 4–6. The maximum adsorption capacity for Cu(II) ion was 2.5 mmol metal/g pristine chitosan membranes. Under this condition, no influence of membrane porosity was observed. However, for membranes with immobilized histidine, the porosity was shown to be a factor that affects the maximum adsorption capacity, with values ranging from 2.0 to 3.0 mmol metal/g chitosan. These results indicate that the immobilization of histidine on porous chitosan membranes presents synergy with porosity in the ability to complex Cu(II) ions. This synergy may be negative or positive, depending on the initial membrane porosity.     

Gas-phase investigation of Pd(II)-alanine complexes with small native and derivatized peptides containing histidine

We report here the generation of gas-phase complexes containing Pd(II), a ligand (deprotonated alanine, A-), and/or N-terminus derivatized peptides containing histidine as one of the amino acids. The species were produced by electrospray ionization, and their gas-phase reactions were investigated using ion-trap tandem mass spectrometry. Pd(II) forms a stable diaqua complex in the gas phase of the formula, [Pd(A-) (H(2)O)(2)]+, (where A- = deprotonated alanine) along with ternary complexes containing A- and peptide. The collision-induced dissociation (CID) patterns of the binary and ternary complexes were investigated, and the dissociation patterns for the ternary complexes suggest that: (a) the imidazole ring of the histidine side group may be the intrinsic binding site of the metal ion, and (b) the peptides fragment primarily by cleavage of the amide bond to the C-terminal side of the histidine residues. These observations are in accord with previous solution-state studies in which Pd(II) was shown to cause hydrolysis of an amide bond of a peptide at the same position.     

Evaluation of chiral recognition characteristics of metal and proton complexes of di-o-benzoyl-tartaric acid dibutyl ester and L-tryptophan in the gas phase

Chiral recognition of di-o-benzoyl-tartaric acid dibutyl ester (T) was achieved in the gas phase by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. In this method two divalent transition metal cations, zinc(II) and copper(II), were used as binding metal ions, and L-tryptophan (A) was used as a chiral reference. Multimeric complexes were readily formed by electrospray ionization of a methanol:water (50:50) solution containing metal ion, L-tryptophan and T. These multimeric complexes included singly charged protonated dimeric [TAH](+), doubly charged copper(II) bound tetrameric [TACu-H](2)(2+) and doubly charged zinc(II) bound tetrameric [TAZn-H](2)(2+), together with other complexes. The mass-selected complex, i.e., [TAH](+), [TACu-H](2)(2+) and [TAZn-H](2)(2+), was used to acquire the second stage mass spectra. The chiral recognition capability of these three complexes was evaluated using the abundance ratios of daughter ion to parent ion. A high degree of chiral recognition ability was observed in [TACu-H](2)(2+) and [TAZn-H](2)(2+). It was found that the type of binding ion played an important role in the chiral recognition. Different binding ions exhibited distinctive dissociation pathways and unique chiral recognition characteristics. The present method is based not only on whole-molecule loss but also on fractional-molecule loss. In addition, the reproducibility of the chiral recognition method was confirmed by several determinations of the abundance ratios of daughter ion to parent ion with a fixed activation energy and with five different activation energies. It was also shown that this chiral recognition method can tolerate acid interference.     

Charge transfers influence on the spin ground state of manganese and iron superoxide dismutases: a DFT study on a model of the reduced active site interacting with O2-

From DFT and time-dependent DFT calculations on Mn(II)SOD and Fe(II)SOD active site models interacting with O2- we have determined that metal-to-ligand charge transfers stabilise the S = 2 and S = 5/2 spin states as ground spin states for the [Mn(II)SOD-02-] and [Fe(II)SOD-O2-] model complexes, respectively. These charge transfers are ruled by the electronic configuration of the metal ion, and they can be determinant in the catalysis reaction.     

Nature of metal binding sites in Cu(II) complexes with histidine and related N-coordinating ligands, as studied by EXAFS

Knowledge of the complexes formed by N-coordinating ligands and Cu(II) ions is of relevance in understanding the interactions of this ion with biomolecules. Within this framework, we investigated Cu(II) complexation with mono- and polydentate ligands, such as ammonia, ethylenediamine (en), and phthalocyanine (Pc). The obtained Cu-N coordination distances were 2.02 A for [Cu(NH(3))(4)](2+), 2.01 A for [Cu(en)(2)](2+), and 1.95 A for CuPc. The shorter bond distance found for CuPc is attributed to the macrocyclic effect. In addition to the structure of the first shell, information on higher coordination shells of the chelate ligands could be extracted by EXAFS, thus allowing discrimination among the different coordination modes. This was possible due to the geometry of the complexes, where the absorbing Cu atoms are coplanar with the four N atoms forming the first coordination shell of the complex. For this reason multiple scattering contributions become relevant, thus allowing determination of higher shells. This knowledge has been used to gain information about the structure of the 1:2 complexes formed by Cu(II) ions with the amino acids histidine and glycine, both showing a high affinity for Cu(II) ions. The in-solution structure of these complexes, particularly that with histidine, is not clear yet, probably due to the various possible coordination modes. In this case the square-planar arrangements glycine-histamine and histamine-histamine as well as tetrahedral coordination modes have been considered. The obtained first-shell Cu-N coordination distance for this complex is 1.99 A. The results of the higher shells EXAFS analysis point to the fact that the predominant coordination mode is the so-called histamine-histamine one in which both histidine molecules coordinate Cu(II) cations through N atoms from the amino group and from the imidazole ring.     

Structure and properties of a series of 2-cinnamoyl-1,3-indandiones and their metal complexes

A series of seven 2-cinnamoyl-1,3-indandiones and their metal(II) complexes were synthesized and characterized by means of spectroscopic (IR, NMR, electron absorption and emission spectroscopy) and/or single-crystal X-ray diffraction methods. The optical spectra of the organic compounds show very strong absorption in the visible region and weak fluorescence with moderate to strong Stokes shift. The effect of concentration, water addition and metal ion complexation on the optical properties was also studied. In search of potential practical application, the complexation of 2-cinnamoyl-1,3-indandiones with metal(II) ions was investigated. A series of non-charged complexes with Cu(II), Cd(II), Zn(II), Co(II) and Ni(II) was isolated and analyzed by elemental analyses and IR. Most of the complexes show presence of water molecules, most probably coordinated to the metal ion, thus forming octahedral geometry. For the paramagnetic Cu(II) complexes a distorted, flattened tetrahedral structure is proposed, basing on the EPR data. The optical properties of the metal complexes, however, do not differ appreciably from those of the free ligands.     

Isothermal titration calorimetry measurements of Ni(II) and Cu(II) binding to His, GlyGlyHis, HisGlyHis, and bovine serum albumin: a critical evaluation

The binding of Ni(II) and Cu(II) to histidine, to the tripeptides GlyGlyHis and HisGlyHis, and to the protein bovine serum albumin has been studied by isothermal titration calorimetry (ITC) to determine the experimental conditions and data analysis necessary to reproduce literature values for the binding constants and thermodynamic parameters. From analysis of the ITC data, we find that there are two major considerations for the use of this method to accurately quantify metal ion interaction with biological macromolecules. First, to determine true pH-independent binding constants, ITC data must be corrected for metal ion competition with protons by accounting for the experimental pH and pKa values of the metal-binding residues. Second, metal interaction with the buffer (stability and enthalpy of formation of metal-buffer complex(es)) must be included in the analysis of the ITC data to determine the binding constants and the change in enthalpy. While it may be possible to use a buffer that forms only weak, and therefore negligible, complexes with the metal, a buffer that has a strong and well-characterized interaction has the benefit of suppressing metal ion hydrolysis and precipitation, and of allowing the quantification of high-affinity metal-binding sites on biological macromolecules. This study has also quantified the contribution of the N-terminal imidazole of HisGlyHis to the stability of the Cu(II) and Ni(II) complexes of this protein sequence and has provided new insight about Cu(II) binding to albumin.