以肿瘤凋亡相关蛋白和基因为靶的小分子*

细胞凋亡的调控作为治疗肿瘤的新兴手段,近年来受到广泛关注。本文对细胞凋亡途径中的重要靶点,包括Bcl-2,IAP,p53等的结构及作用机制作了较详尽的阐述,并且总结了针对上述不同靶点的对细胞凋亡进行调控的化学小分子的研究。在对这些研究现状进行分析的基础上,对该研究领域下一步的发展方向提出了我们的观点。     

Characterization and application of d-amino acid oxidase and catalase within permeabilized <Emphasis Type="Italic">Pichia pastoris</Emphasis> cells in bioconversions

The high-density fermentation of recombinant Pichia pastoris was carried out in a 1-L fermentor. After 60 h of fermentation, the activities of D-amino acid oxidase (DAAO) and catalase assayed with the permeabilized cells attained 12,532 and 684,800 U/L, respectively. Additionally, the stability of DAAO and catalase within the permeabilized cells was relatively high. The half-life of the two enzymes reached 14.5 and 4.0 d at 30 degrees C, respectively. Furthermore, these permeabilized cells could convert D-phenylalanine into 99% phenylpyruvate within 100 min and could be efficiently reused up to 13 cycles. After being treated with base and heating, these treated permeabilized cells could be reused up to three cycles in a batchwise conversion of cephalosporin C, and about 90% 7-beta-(4-carboxybutanamido)-cephalosporanic acid was ultimately obtained at each cycle.     

Study of the feasibility of distinguishing cigarettes of different brands using an Adaboost algorithm and near-infrared spectroscopy

The feasibility of utilizing an Adaboost algorithm in conjuction with near-infrared (NIR) spectroscopy to automatically distinguish cigarettes of different brands was explored. Simple linear discriminant analysis (LDA) was used as the base algorithm to train all weak classifiers in Adaboost. Both principal component analysis (PCA) and its kernel version (kernel principal component analysis, KPCA) were used for feature extraction and were also compared to each other. The influence of the training set size on the final classification model was also investigated. Using a case study, it was demonstrated that Adaboost coupled with PCA or KPCA can obviously improve the ability to discriminate between samples that cannot be separated by a single linear classifier. However, in term of the overall performance, KPCA appears preferable to PCA for feature extraction, especially when the samples used for training are relatively small. The results also indicate that more training samples should be applied, if possible, in order to fully demonstrate the superiority of Adaboost. It seems that the use of an Adaboost algorithm in conjunction with NIR spectroscopy in combination with KPCA for feature extraction comprises a promising tool for distinguishing cigarettes of different brands, especially in situations where there is an obvious overlap between the NIR spectra afforded by cigarettes of different brands.     

One-step purification of epigallocatechin gallate from crude green tea extracts by mixed-mode adsorption chromatography on highly cross-linked agarose media

(-)-Epigallocatechin gallate (EGCG) was purified in one step from a green tea polyphenol (GTP) crude extract by adsorption chromatography on a Superose 12 HR 10/30 column. The mobile phase used was a mixture of acetonitrile and water with an optimum mobile phase compositions regarding purity, recovery and separation time of 78/22 (v/v). Maximum practical sample loading was 100 mg GTP per run (corresponding to 4.2 mg/ml Superose). An EGCG purity of 99% with recoveries in the range 60-65% was achieved in one step directly from the crude GTP extract. Full column regeneration was obtained using solvents in the following order: 0.5 M NaOH, distilled water and 30% acetic acid.     

Catalytic Oxidation of Dimethyl Ether to Dimethoxymethane over Cs Modified HaPW12O40/SiO2 Catalysts

The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40（40%）/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modification of H3PW12O40（40%）/SiO2 gave the most promising result of 20% dimethyl ether conversion and 34.8% dimethoxymethane selectivity. Dimethoxymethane could be synthe- sized via methoxy groups decomposed from dimethyl ether through the synergistic effect between the acid sites and the redox sites of Cs modified H3PW12O40（40%）/SiO2.     

四足配体铽配合物-蒙脱土超分子复合发光材料的插层组装、表征和性质研究

用两种方法分别将四足配体铽配合物[TbL（NO3）]^2＋和[TbL]^3＋插层组装到了蒙脱土（MT）层板间，制备出超分子复合发光材料[TbL（NO3）^2＋-MT和[TbL]^3＋-MT。方法一：通过离子交换反应让配离子[TbL（NO3）]^2＋取代钠＋基蒙脱土（Na-MT）中的Na^＋离子，插层组装到蒙脱土层板间。方法二：用配体L与铽基蒙脱土（Tb-MT）反应，使配体插入蒙脱土层板间与Tb^3＋离子配位。用元素分析、XRD，FT-IR,UV-vis和热分析对材料进行了表征，并对其荧光性质进行了研究。结果表明，复合材料保持了蒙脱土良好的层柱结构特征，其层间距d001值与插层配离予的直径吻合较好，配离子以单层形式分布于蒙脱土层板间，复合材料中配合物的热稳定性有明显提高。在紫外光激发下，复合材料发出较强的Tb^3＋特征荧光，其发射光谱与相应配合物的发射光谱很相似；复合材料中配合物的相对荧光强度较相应纯配合物有明显提高。荧光寿命较长；配合物的激发波长向可见光区发生位移，说明插层组装实现了对配合物激发波长的调制作用。     

Synthesis and thermodynamic properties of a metal-organic framework: [LaCu6(μ-OH)3(Gly)6im6](ClO4)6

A metal-organic complex, which has the potential property of absorbing gases, [LaCu₆(μ-OH)₃(Gly)₆im₆](ClO₄)₆ was synthesized through the self-assembly of La³⁺, Cu²⁺, glycine (Gly) and imidazole (Im) in aqueous solution and characterized by IR, element analysis and powder XRD. The molar heat capacity, C_p,m, was measured from T = 80 to 390 K with an automated adiabatic calorimeter. The thermodynamic functions [H_T − H_298.15] and [S_T − S_298.15] were derived from the heat capacity data with temperature interval of 5 K. The thermal stability of the complex was investigated by differential scanning calorimetry (DSC).     

Adiabatic calorimetry and thermal analysis on acetaminophen

Molar heat capacities of acetaminophen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 330 K. A solid-solid transition at 149.96 K was found from the C_p,m-T curve. The polynomial functions of C_p,.m(J K^-1 mol^-1) vs. T were established on the heat capacity measurements by means of the least square fitting method. Thermal decomposition processes of acetaminophen have been studied by thermogravimetry. And the thermal decomposition kinetics parameters, such as activation energy E, pre-exponential factor A and reaction order n, were calculated by TG-DTG techniques with the Freeman-Carroll method, Kissinger method and Ozawa method. Accordingly the thermal decomposition kinetics equation of acetaminophen is expressed as: dα/dt=2.67·10⁷e^-89630/RT(1-α)^0.23. The process of fusion has been investigated through DSC. The melting point, molar enthalpy and entropy of fusion are to be (441.89±0.04) K, 26.49±0.44 kJ mol^-1 and 59.80±1.01 J K^-1 mol^-1, respectively.     

Synthesis and luminescence properties of lanthanide complexes with a new aryl amide bifunctional bridging ligand

A new aryl amide type bifunctional bridging ligand 4,4'-bis{[(2'-benzylaminoformyl)phenoxyl]methyl}-1,1'-biphenyl (L) and its complexes with lanthanide ions (Ln=Pr, Eu, Gd, Tb, Ho, Er) were synthesized and characterized by elemental analysis, infrared spectra, conductivity measurements and thermal analysis. At the same time, the luminescence properties of the Eu and Tb complexes in acetone solutions were investigated. Under the excitation of UV light, these two complexes exhibited characteristic emission of europium and terbium ions. And the lowest triplet state energy level T1 of this ligand matches better to the lowest resonance energy level of Tb(III) than to Eu(III) ion.