具抗凝血作用的三种钕配合物与人血清白蛋白的相互作用

采用荧光光谱法,紫外光谱法以及圆二色谱法研究了具抗凝血作用的水杨酸钕((NdL′3.2H2O,L′=水杨酸离子))、华法灵钕(NdL3.2H2O,L=华法灵离子)和华法灵水杨酸钕(NdL2L′.2H2O)3种配合物与人血清白蛋白的相互作用。结果表明:配合物对人血清白蛋白(HSA)的荧光产生猝灭现象;配合物的存在使得HSA紫外吸收光谱的强度增加;配合物的存在也对HSA的构象产生影响。水杨酸钕的猝灭方式为动态与静态猝灭,而华法灵钕和华法灵水杨酸钕的猝灭方式属于两者之间生成了不发荧光的复合物而导致的静态猝灭。并分别确定了它们的结合力类型:华法灵钕与HSA之间主要作用力是静电作用力;水杨酸钕与HSA之间主要作用力为典型的疏水作用力;华法灵水杨酸钕与HSA之间为氢键和范德华力。计算了配合物与人血清白蛋白的结合常数K和结合位点数n。     

Synthesis,reactions with DNA,and antitumor activity of platinum complexes with aminonitroxyl radicals

The work is a review of the data on the synthesis of mono- and biradical Pt^II complexes with mono- and diaminonitroxyl radicals, as well as of a binuclear complex with diaminonitroxyl radical. A “mild” method is considered for the synthesis of a number of Pt^IV nitroxyl complexes (9–11), whose lipophilicity varies within a wide range due to the trans-ligands, i.e., the linear aliphatic acid moieties. Correlations between the structures of the complexes, efficiency of their binding to DNA, and the effect of this binding on the DNA stability were established. Cytotoxic properties of the complexes against the HeLa, H1299, and MCF7 tumor cells, the effect of the complexes on the cell cycle, and the p53 protein expression were studied. The data on the antitumor activity of the complexes in the animal tumor model, P388 leukemia, are given. The rate of the development of resistance to complex 10a for P388 leukemia is 2.5 times lower than the corresponding value for cisplatin. It was found that a synergistic enhancement of antitumor activity is observed when low doses of cisplatin and complexes 9b or 10b are simultaneously administered. The specificities of biological activity of the platinum nitroxyl complexes are presumably due to the antioxidant properties of the nitroxyl pharmacophore and the ability of these complexes to cause the p53-independent tumor cell death.     

Modeling of 1,2,4,5-tetrazine complexes with organic amines

Tetrazine complexes with organic ligands have been modeled. The composition and structure of the model complexes agree with experimental data. The structure and nature of the complexes affect a number of chemical reactions of 1,2,4,5-tetrazines with organic amines. It is shown that the possibility and route of nucleophilic substitution in the 3 and 6 positions of the tetrazine ring are provided by amine localization in the tetrazine complex and also by the orbital characteristics of the reagents. The route and possibility of cycloaddition reactions for tetrazines are dictated by the ability of the latter to form π-complexes with reagents and by the orbital characteristics of the complexes. The route of the cycloaddition reaction is also affected by the solvent.     

大环多胺及其金属配合物与DNA的相互作用*

本文综述了近年来基于大环多胺及其金属配合物与DNA相互作用的研究进展,着重介绍本课题组在有关单双核、多核以及功能化大环多胺衍生物及其金属配合物与DNA相互作用方面的研究和发现,并对其在化学核酸酶方面的应用进行了讨论。在单双核大环多胺衍生物方面,我们分别合成了以吡啶、苯环、咪唑、三氮唑为侧臂的单核大环多胺金属配合物,同时合成了以刚性桥相连的双核配合物和以柔性链相连的双核配合物。并研究这些单双核大环多胺与DNA的相互作用,发现以刚性链相连的双核大环多胺金属配合物具有很好的切割DNA的性质,可以在低浓度、短时间内切断DNA。在功能化大环多胺方面,我们合成了含有碱基、PNA单体、咪唑鎓盐、冠醚、二茂铁等功能化基团的大环多胺衍生物及金属配合物,并研究了其与DNA的相互作用。在多核大环多胺方面,我们合成了基于大环多胺的寡聚物,研究发现该类物质可与DNA形成复合物,从而有效地保护DNA免于酶解。     

Mesomorphism of lanthanide-containing Schiff's base complexes with chloride counterions

Liquid crystalline complexes [Ln(LH) 3 Cl 3 ] have been synthesized, where Ln is a trivalent lanthanide ion (Pr-Lu, except Pm) and where LH is the Schiff's base ligand N -octadecyl4-tetradecyloxysalicylaldimine. Although the ligand does not exhibit mesomorphism, the complexes do (SmA phase). The mesophase behaviour of these compounds has been investigated by polarizing optical microscopy, differential scanning calorimetry and high temperature X-ray diffraction. The lanthanide complexes have much higher melting and clearing points than comparable complexes with nitrate or dodecyl sulphate counterions. In addition, the transition temperatures are virtually independent of the type of lanthanide ion. This behaviour is opposite to that observed for similar complexes with nitrate counterions [Ln(LH) 3 (NO 3 ) 3 ]. The differences in temperature dependence can be related to structural differences. Whereas in the nitrate complexes the Schiff's base ligand binds in a zwitterionic form, two-dimensional 1H NMR correlation spectroscopy (COSY) of [Lu(LH) 3 Cl 3 ] gives an indication that in the chloride complexes, besides coordination via the oxygen of molecules in the zwitterionic form, some of the Schiff's base ligands bind in a bidentate fashion (via the phenolic oxygen and the imine nitrogen).     

Computational study of the interaction of indole-like molecules with water and hydrogen sulfide

The characteristics of the interaction between water and hydrogen sulfide with indole and a series of analogs obtained by substituting the NH group of indole by different heteroatoms have been studied by means of ab initio calculations. In all cases, minima were found corresponding to structures where water and hydrogen sulfide interact by means of X-H···π contacts. The interaction energies for all these π complexes are quite similar, spanning from -13.5 to -18.8 kJ/mol, and exhibiting the stability sequence NH > CH(2) ≈ PH > Se ≈ S > O, for both water and hydrogen sulfide. Though interaction energies are similar, hydrogen sulfide complexes are slightly favored over their water counterparts when interacting with the π cloud. σ-Type complexes were also considered for the systems studied, but only in the case of water complexes this kind of complexes is relevant. Only for complexes formed by water and indole, a significantly more stable σ-type complex was found with an interaction energy amounting to -23.6 kJ/mol. Oxygen and phosphorous derivatives also form σ-type complexes of similar stability as that observed for π ones. Despite the similar interaction energies exhibited by complexes with water and hydrogen sulfide, the nature of the interaction is very different. For π complexes with water the main contributions to the interaction energy are electrostatic and dispersive contributing with similar amounts, though slightly more from electrostatics. On the contrary, in hydrogen sulfide complexes dispersion is by far the main stabilizing contribution. For the σ-type complexes, the interaction is clearly dominated by the electrostatic contribution, especially in the indole-water complex.     

Theoretical Studies on the Interactions of Cations with Diazine

1 INTRODUCTION Interaction between cations and π electron systems is a kind of common and important non-covalent inter- action[1～21]. It could be observed in many systems, such as gas ion-molecule complexes and biological macromolecular proteins. Especially, in biological macromolecular systems, this interaction is signi- ficant for revealing the structures and functions of proteins or disclosing the atomic essence of protein- ligand effect. Interaction between benzene and metal ions h…     

Complexes of sodium and lithium borohydrides with macrocyclic polyethers

A method for the synthesis of complexes of sodium and lithium borohydrides with crown ethers is proposed. The complexes of sodium borohydride with benzo-15-crown-5, 4′-aminobenzo-15-crown-5, dibenzo-18-crown-6, and diaza-18-crown-6 and the complexes of lithium borohydride with benzo-15-crown-5 and dibenzo-18-crown-6 are synthesized. These complexes can be used for the preparation of hydrogen in their reactions with methanol. The complex formation does not affect the purity of hydrogen formed.     

Molecular complexes of 1,3,5-trinitrobenzene with naphthalene and its derivatives

The relation between spectral parameters of molecular complexes formed by 1,3,5-trinitrobenzene with naphthalene derivatives and ionization potentials of the donor molecule is discussed. The molecular complexes were divided into three groups: naphthalene, naphthalene-1-amine, and naphthalene-2-amine derivatives. This division was substantiated in terms of the existence of several intermolecular interactions between the components and steric structure of the complexes. Problems related to classification of molecular complexes are discussed.     

Interaction of ampholyte dendrimers with linear polyelectrolytes

The interaction of ampholyte propylenimine dendrimers containing peripheral carboxyl groups and inner tertiary amino groups with linear polyelectrolytes has been studied. Both in acidic and alkaline media up to pH ～ pI, dendritic polyampholytes can form interpolyelectrolyte complexes with flexible linear polyanions and polycations. A variation in the composition of complexes with a change in pH is associated with the formation of intramolecular zwitterion pairs in a dendrimer molecule. The ability of interpolyelectrolyte complexes to dissolve in water is shown to be determined by the degree of dissociation of ionogenic groups of the dendrimer not directly involved in the formation of interpolyelectrolyte salt bonds stabilizing the complex. It has been demonstrated that the territorial separation of carboxyl and tertiary amino groups in the polyampholyte dendrimers is reflected in different structures of interpolyelectrolyte complexes formed by dendrimers with oppositely charged linear polyions.     

铈—邻苯二酚衍生物配合物的氧化显色反应及其机理

对邻苯二酚、邻苯二酚－３，５－二磺酸钠、连苯三酚、３，４－二羟基苯甲酸及３，４－５－三羟基苯甲酸等系列邻苯二酚衍生物笔Ｃｅ＾３＋生成紫红色配合物的反应进行了研究，结果表明，该显色反应是因Ｃｅ＾３＋配合物被氧化成了Ｃｅ＾４＋配合物；提出了Ｃｅ＾３｜与这类试剂氧化显色反应的机理并对其进行了验证实验。     

Molecular complexes of paraquat with anilines

The U V-VIS spectra of molecular complexes of paraquat with ring and N-substituted anilines have been recorded in methanol and 50% v/v aqueous methanol. All the complexes exhibited well-resolved charge transfer bands in the wavelength region where neither of the components have any absorption. The energies of charge transfer bands of the substituted aniline-paraquat complexes bear linear relationships with the ionization potentials obtained from the substituted aniline-TCNE complexes, indicating π - π interaction between paraquat and the donors. Both ring and N-substituents have effects on the positions of the CT bands as well as on the stabilities of the complexes. The positions of the CT bands are shifted to shorter wavelengths and the stabilities of the complexes decrease on going from methanol to aqueous. methanol.     

Liquid crystalline behaviour of hydrogen-bonded complexes of alkoxycinnamic acids with octyloxystilbazole

Hydrogen-bonded liquid crystalline complexes have been obtained through 1:1 (molar ratio) complexation of 4- n -alkoxycinnamic acids ( n CNA: n = 4, 8, 10, 12, where n is the number of carbons in the alkyloxy chain) and trans -4-octyloxystilbazole (8Sz). These hydrogen-bonded complexes ( n CNA8Sz) form stable mesophases. The mesomorphic range was extended by the mixing of complexes. Hexatic modification of smectic B (SmB h ), smectic C (SmC), smectic A (SmA), and nematic mesophases of these complexes were determined by a combination of X-ray diffraction and polarizing optical microscopy. Transitions between the various smectic phases were deduced from the temperature-dependent layer spacing of n CNA8Sz. The layer spacing of these complexes in the SmB h and SmA phases gradually increased with increasing alkoxy chain length. The favouring of smectic phases in these complexes is believed to originate from the increment of polarity of the mesogen by intermolecular H-bonding.     

Characterization of non-covalent complexes of rutin with cyclodextrins by electrospray ionization tandem mass spectrometry

Electrospray ionization tandem mass spectrometry (ESI-MS(n)) and the phase solubility method were used to characterize the gas-phase and solution-phase non-covalent complexes between rutin (R) and alpha-, beta- and gamma-cyclodextrins (CDs). The direct correlation between mass spectrometric results and solution-phase behavior is thus revealed. The order of the 1 : 1 association constants (K(c)) of the complexes between R and the three CDs in solution calculated from solubility diagrams is in good agreement with the order of their relative peak intensities and relative collision-induced dissociation (CID) energies of the complexes under the same ESI-MS(n) condition in both the positive and negative ion modes. Not only the binding stoichiometry but also the relative stabilities and even binding sites of the CD-R complexes can be elucidated by ESI-MS(n). The diagnostic fragmentation of CD-R complexes, with a significant contribution of covalent fragmentation of rutin leaving the quercetin (Q) moiety attached to the CDs, provides convincing evidence for the formation of inclusion complexes between R and CDs. The diagnostic fragment ions can be partly confirmed by the complexes between Q and CDs. The gas-phase stability order of the deprotonated CD-R complexes is beta-CD-R > alpha-CD-R > gamma-CD/R; beta-CD seems to bind R more strongly than the other CDs.     

Mixed-ligand complexes of copper with some amino-acids and malonate

The mixed-ligand complexes formed by copper(II) with an amino-acid (valine, threonine, isoleucine, aspartic acid, glutamic acid, lysine) and malonic acid have been investigated polarographically and their stability constants determined. The complexes are less stable than the corresponding complexes with oxalic acid instead of malonic, but also exhibit less disproportionation into the simple complexes, because the simple oxalate complexes are more stable than the malonate complexes.     

Tautomerism of metal complexes with quinalizarin

The formation of complexes with quinalizarin was found to occur through the peri-hydroxycarbonyl groups with participation of tautomers and conformers. The diversity of the electronic absorption spectra of quinalizarin complexes is explained not only by the ligand ionization degree but also by the shifts in the tautomeric and conformer equilibria. The classification of the known quinalizarin complexes is suggested on the basis of spectrophotometric data and quantum-chemical calculations of the π _l ,π^*-band position by the Pariser-Parr-Pople method.     

Mesomorphism of lanthanide-containing Schiff's base complexes with chloride counterions

Liquid crystalline complexes [Ln(LH)3Cl3] have been synthesized, where Ln is a trivalent lanthanide ion (Pr-Lu, except Pm) and where LH is the Schiff's base ligand N-octadecyl4-tetradecyloxysalicylaldimine. Although the ligand does not exhibit mesomorphism, the complexes do (SmA phase). The mesophase behaviour of these compounds has been investigated by polarizing optical microscopy, differential scanning calorimetry and high temperature X-ray diffraction. The lanthanide complexes have much higher melting and clearing points than comparable complexes with nitrate or dodecyl sulphate counterions. In addition, the transition temperatures are virtually independent of the type of lanthanide ion. This behaviour is opposite to that observed for similar complexes with nitrate counterions [Ln(LH)3(NO3)3]. The differences in temperature dependence can be related to structural differences. Whereas in the nitrate complexes the Schiff's base ligand binds in a zwitterionic form, two-dimensional 1H NMR correlation spectroscopy (COSY) of [Lu(LH)3Cl3] gives an indication that in the chloride complexes, besides coordination via the oxygen of molecules in the zwitterionic form, some of the Schiff's base ligands bind in a bidentate fashion (via the phenolic oxygen and the imine nitrogen).     

Thermal and structural studies of the chloro complexes of cobalt,nickel and copper with 3-phenylpyridine

The chloro complexes of cobalt, nickel and copper with 3-phenylpyridine were prepared in ethanolic solution from which solid compounds were isolated. The cobalt and copper complexes have stoichiometry M₂LCl₄ while the nickel complex has stoichiometry NiLCl₂. The suggested structure for the cobalt and copper complexes is tetrahedral, while for the nickel complex it is octahedral. Thermal analysis studies show that the cobalt and copper complexes form intermediate complexes before their metal oxides are produced. The nickel complex also forms an intermediate complex and then nickel chloride before the nickel oxide is obtained.     

Water-soluble nonstoichiometric polyelectrolyte complexes of chitosan with a polystyrenesulfonate anion

Chitosan complexes that meet the performance criteria of water-soluble nonstoichiometric polyelectrolyte complexes have been first prepared via the interaction of chitosan with excess polystyrenesulfonate anions in acidic media. Thus, the region of the existence of soluble complexes can be narrowed down through a decrease in the degree of polymerization of a lyophilizing polyanion until fully degenerates as in the case of oligomeric anions. The critical concentration of a salt that brings about phase separation decreases with an increase in the relative content of a blocking chitosan in a mixture and depends on the ratio of chain lengths of polymer components. This is also typical of nonstoichiometric polyelectrolyte complexes. The results of this study may be useful for designing soluble chitosan complexes with polyanions, including those of biological origin.     

稀土-香兰素缩赖氨酸希夫碱配合物的合成、表征及其与DNA作用的研究

合成了香兰素缩赖氨酸希夫碱配体(HL)和15种香兰素缩赖氨酸希夫碱的稀土配合物REL(NO3)2.3H2O(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu),并通过元素分析、摩尔电导、热重分析、红外光谱、紫外光谱、核磁共振方法对配合物的组成和结构进行了表征。采用紫外光谱和荧光光谱方法初步研究了Nd,Tb,Yb,Lu这4种希夫碱配合物与DNA的相互作用,实验结果显示,随着DNA的加入,配合物在280 nm处的紫外吸收峰不断增强,同时配合物在418 nm左右的荧光发射峰随DNA浓度的增大均逐渐减小,说明配合物和DNA是以静电模式结合。