Interaction of the La(III)–Morin Complex with Human Serum Albumin

Journal of Solution Chemistry - Lanthanum (La) is one of the most reactive rare earth elements, whose carbonate had been approved by the FDA for marketing as a treatment drug for hyperphosphatemia....     

EXFAS electron spectroscopy as a new tool of local characterisation of copper in Cu-Beta zeolite

EXFAS spectroscopy has been applied for the first time to the study of the local characterisation of reduced copper in zeolites. The oscillating features observed beyond the Cu M_2,3VV Auger transition have been isolated and analysed following the standard EXAFS procedure.     

Study on the Synergism Effect of Lomefloxacin and Ofloxacin for Bovine Serum Albumin in Solution by Spectroscopic Techniques

Both lomefloxacin (LOM) and ofloxacin (OFL) have a powerful ability to quench the fluorescence of bovine serum albumin (BSA). The fluorescence quenching action is much stronger when the two drugs coexist. The synergism between LOM and OFL was studied using fluorescence and ultraviolet spectroscopy under imitated physiological conditions. The results show that static quenching and non-radiation energy transfer are the main reasons for the fluorescence quenching. The synergism results in both the reduction of the binding stability between drugs and BSA and an increase of the free drug concentration, which will increase the efficacy of drugs. The thermodynamic parameters at different temperatures were calculated and the binding distances r between the drugs and BSA were obtained based on Försters theory of non-radiation energy transfer. The synchronous fluorescence spectra indicated that the effect of synergism affected the conformation of BSA.     

Synthesis,Crystal Structure and Cytotoxic Property of <Emphasis Type="Italic">catena</Emphasis>-Poly[[{2-[2-(methylamino)ethyliminomethyl]-4-nitrophenolato}Zinc(II)]-μ-acetato]

Abstract  

The acetato-bridged polymeric Schiff base zinc(II) complex [Zn(MENP)(CH₃COO)]_n (MENP = 2-[2-(methylamino)ethyliminomethyl]-4-nitrophenolate) was synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P2₁/c with a = 14.054(2), b = 11.167(1), c = 9.323(2) ?, β = 92.053(2)°, V = 1462.2(4) ?³, Z = 4, R ₁ = 0.0420 and wR ₂ = 0.1019. The Zn atom is coordinated in a trigonal–bipyramidal manner by one Schiff base ligand and two bridging acetate anions. The adjacent Zn···Zn distance is 4.727(2) ?. The [Zn(MENP)] units are linked through the bridging acetate groups, forming chains running along the c axis. The complex shows slight cytotoxic property to both normal and carcinoma cells.     

Copper supported on N-heterocyclic carbene-functionalized porous organic polymer for efficient oxidative carbonylation of methanol

A new heterogeneous catalyst for the oxidative carbonylation of methanol to dimethyl carbonate based on copper coordinated in N-heterocyclic carbene-functionalized porous organic polymer (Cu@PQP-NHC) was presented. The solid catalyst that featured relatively large surface area, hierarchical pore structure, and excellent swelling property, was prepared via a facile copolymerization reaction of tetra-vinylphosphonium salt and bis-vinylimidazolium salt, followed by successful immobilization of CuCl. Accordingly, the resulting Cu@PQP-NHC showed excellent catalytic performance for the oxidative carbonylation of methanol. A 10 mmol/l of Cu usage was sufficient for 9.3% conversion of methanol with a high TOF number of 57 h⁻¹. Importantly, the catalyst was easily recovered by simple centrifugation, and could be reused up to 10 consecutive recycles without obvious loss of its initial activity. Also, the solid catalyst showed negligible Cu leaching during the recycling, and 99% Cu species was still retained after reusing 10 times. The results in this study highlights the advantages of porous organic polymer supported NHC-Cu catalyst as a highly active and stable heterogeneous catalyst, providing a promising route for the synthesis of dimethyl carbonate.     

Spectroscopic Study of the Interactions of Buflomedil to Serum Albumin and β-Cyclodextrin

The effects of buflomedil (BFM), a novel cerebrovascular medicine, on serum albumin and the feasibility of ??-cyclodextrin (??-CD) acting as a controlled releaser for BFM were investigated by molecular spectroscopy methods, including fluorescence emission, UV?Cvisible absorption, Fourier transform infrared (FT-IR), synchronous and three-dimensional fluorescence spectroscopies. The interaction of BFM with bovine serum albumin (BSA) was analyzed by fluorescence quenching and it was found that BFM had reacted with BSA in the ground state and had affected the secondary structure of BSA. The observed binding constant K _b, the number of binding sites n, the distance r between donor (BSA) and acceptor (BFM), the enthalpy change (??H ^?? ), Gibbs energy change (??G ^?? ) and entropy change (??S ^?? ) at different temperatures were calculated. The inclusion reaction between ??-CD and BFM was explored by the Lineweaver?CBurk equation. The inclusion constants and the thermodynamic parameters were determined. The mechanism of the inclusion reaction was discussed and the controlled release characteristics of ??-CD to BFM were considered at the molecule level.     

实验数据处理的excel函数解法研究

回归分析是一类数学模型,其研究对象是一个随机变量同一个或多个非随机变量的关系问题,在提出一元和多元线性回归的基础上,通过比较最小二乘法解法和Excel函数解法,指出Excel函数解法可以简化复杂的数学运算,并配以图表,给求解过程带来方便。     

可参数化曲面上特征值比较的数值计算原理

对于一个给定的完备可参数化曲面,我们给出了其上特征值比较时进行数值计算所遵循的基本原理.