生物素标记试剂的合成方法改进及其在DNA合成中的应用

以生物素,4,4’-二甲氧基三苯基氯甲烷,6-氨基-1-己醇,2-氰基乙氧基-双(N,N-二异丙基)亚磷酰胺等为原料,采用改进方法合成了生物素标记试剂——[1-N-(4,4’-二甲氧基三苯甲基)-生物素-6-氨基己基]-2-氰乙氧基-N,N-二异丙基亚磷酰胺(3),总收率51.0%,其结构经1H NMR,13C NMR,31P NMR和MS确证。通过固相亚磷酰胺三酯法,应用3合成了一段含有十个碱基的5’-端生物素标记的寡核苷酸链,其结构经MS确证。     

N-碘代乙酰基-N’-生物素-3,6-二氧杂辛烷-1,8-二胺的简便合成

报道N-碘代乙酰基-N’-生物素-3,6-二氧杂辛烷-1,8-二胺(4)的简便合成方法。以3,6-二氧杂辛烷-1,8-二氨和D-生物素为原料,经4步反应,高收率(74.9%)地合成了4,其结构经1H NMR确证。     

生物素的全合成

本文综述国外学者在生物素合成方面所作的工作, 简述生物素的生化功能, 并指出在我国进行生物素合成开发研究的必要性和迫切性。     

11-巯基十一酸-(8-生物素酰胺基-3,6-二氧辛基)酰胺的合成

以溴十一酸、苄硫醇、生物素和长醚链二胺为原料,通过活化酯法,设计并合成了一种新型长链含巯基的生物素衍生物--11-巯基十一酸-(8-生物素酰胺基-3,6-二氧辛基)酰胺,其结构经<'1>H NMR和IR表征.     

1,3-二苄基-4-(4-甲氧羰基丁基)-噻吩并[3,4-d]-咪唑-2-酮的合成

1,3-二苄基-4-(4-甲氧羰基丁基)-噻吩并[3,4-d]-咪唑-2-酮(Ⅰ)是合成生物素的一个关键中间体.在超声波促进下,用低价钛试剂对(4 aR)-1,3-二苄基-4-(1-己二酸单甲酯酰基硫甲基)-咪唑-2,5-二酮(Ⅱ)进行还原偶联,即生成1,3-二苄基-4-(4-甲氧羰基丁基)-噻吩并[3,4-d]咪唑-2-酮(Ⅰ).超声反应1.5 h,收率71%.     

气相色谱法测定不对称催化合成反应液中手性1,1-二苯基-2-丙醇含量

(S)-(+)-1,1-二苯基-2-丙醇是一种很有用的医药中间体,用它可以合成生物素,此物质广泛应用于医学各领域。近年来大量研究证实,生物素-亲和素(BAS)系统几乎可与目前研究成功的各种标记物结合。在生物素-亲和素(BAS)系统中,借助所形成的生物素-亲和素-酶复合物,追踪生物素标记的抗原或抗体,通过酶催化底物显色,可检出相应的抗体或抗原。由于抗原或抗体分子可偶联多个生物素,     

原位Cu(Ⅰ)催化的叠氮-炔环加成反应合成长链双功能分子：蓝萼甲素与生物素的长链轭合分子的制备（英文）

新型生物素标记的蓝萼甲素可以作为潜在的、基于生物活性的靶标蛋白质的探针.利用原位Cu(I)催化的叠氮-炔环加成反应,以高区域选择性和较高收率合成了系列蓝萼甲素的生物素长链轭合分子.研究发现,在优选的反应条件下,原位还原生成的Cu(I)可以很好地被溶剂化,从而展现了高催化活性.本方法较好地解决了针对双长链的叠氮-炔环加成收率普遍较低的问题,简便,条件温和,同样适用于其他以三氮唑链接的长链双功能分子的合成.     

生物素-亲和素放大酶联免疫吸附法测定二乙基磷酸酯类有机磷农药

基于生物素和亲和素之间发生特异性反应,形成多酶系统,建立了二乙基磷酸酯类有机磷农药的竞争酶联免疫分析技术和生物素-亲和素放大酶联免疫分析技术.在优化条件下,二乙基磷酸酯类有机磷农药浓度在1×10-1～1×104 μg/L范围内与抑制率线性关系良好,其线性回归方程为y＝0.1168x+0.6259(r＝0.9889),半...     

1,3-二炔的合成

随着1,3-二炔类化合物在有机合成及功能材料等领域的广泛应用,它的合成引起了广大研究者的关注.本文阐述了1,3-二炔类化合物的合成发展历史,着重综述了近十年来1,3-二炔类化合物的合成发展情况,按原料类别进行介绍,主要包括以末端炔、炔基卤化物、金属炔化物和烯基卤化物等为原料合成1,3-二炔化合物的新成果.文章还分析了一些合成方法在医药领域的应用和重要的反应机理,并总结了该类化合物的合成及未来发展方向.     

6-羧甲硫基-7-硝基庚酸甲酯二环己基铵盐的合成

生物素（即维生素Ｈ）是重要的维生素，对人体及家禽的生长起着重要的作用［１］。现在国内所用生物素均从日本进口，而且未见国内有合成及应用方面的报道，因此进行生物素合成的研究是非常必要的。我们采用了由己内酯出发经中间体６－羧甲硫基－７－硝基庚酸甲酯二环己基...     

Alteration in photosystem II photochemistry of thylakoids isolated from senescing leaves of wheat seedlings

Wheat seedlings, grown for 7 days in the light, were allowed to senesce in the light or dark, and the change in the photosystem II (PS II) photochemistry of chloroplasts isolated from the primary leaves of these seedlings was investigated. The decrease in oxygen evolution and the fast fluorescence results indicated that the impairment of PS II in the leaves of seedlings senescing in the light was different from that in the leaves of seedlings senescing in the dark. Thermoluminescence studies showed a structural modification in the Q_B protein of chloroplasts isolated from leaves senescing in the light and an alteration in the S state transition of chloroplasts isolated from leaves senescing in the dark.     

An Evidence-Based Review of Application Devices for Nitric Oxide Concentration Determination from Exhaled Air in the Diagnosis of Inflammation and Treatment Monitoring

The measurement of nitric oxide (NO) in exhaled air is used in diagnostics and monitoring the pathologies not only in the respiratory system but also in the oral cavity. It has shown a huge increase in its level in asthma and diseases of the oral cavity. It seems reasonable to undertake research on the impact of inflammation on the level of NO in exhaled air. The aim of the study is to make an evidence-based review of the application of NO levels in exhaled air in the diagnosis of inflammation and treatment monitoring on the basis of selected measuring devices. Methods and Results: This paper presents an example of the application of NO measurement in exhaled air in individual human systems. Selected measuring devices, their non-invasiveness, and their advantages are described. Discussion: The usefulness of this diagnostic method in pathologies of the oral cavity was noted. Conclusions: Measuring the level of NO in exhaled air seems to be a useful diagnostic method.     

Analytical strategies to determine antibiotic residues in fish

The accelerated growth of aquaculture has resulted in a series of harmful effects to human health. The widespread and unrestricted use of antibiotics in this industry, to prevent bacterial infections, leads to remaining amounts in the aquatic environment. This has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase in antibiotic resistance in fish pathogens as well as in the transfer of these resistance determinants to human pathogens. Moreover, the use of large amounts of antibiotics may lead to the presence of residual antibiotics in fish tissue and fish products. Fluoroquinolones, tetracyclines, penicillins, sulphonamides and other antibiotics, exhibiting activity against both Gram-positive and Gram-negative bacteria, are widely used for the treatment and prevention of diseases in fish. An extended and comprehensive review on the recent analytical methodologies concerning antibiotic residues in fish reported in the literature is provided in the present article. Emphasis is given on sample preparation regarding isolation and purification, chromatographic conditions and method validation according to legislation. Results of published assays are comparatively presented and criticised.     

Effect of the displacement reaction on the composition of the magnetic layer in electrodeposited layered nanostructures Co-Cu/Cu and Ni-Cu/Cu

Methods of stripping voltammetry, quartz microgravimetry, and x-ray-fluorescence analysis are employed to explore the copper displacement process on thin electrodeposited layers of pure cobalt and nickel and on deposits of these metals with inclusions of copper. The displacement reaction proceeds at a considerable rate on cobalt in the sulfate and sulfosalicylate solutions and virtually does not proceed on nickel in both the sulfate or sulfate-chloride solutions. An estimate of the rate of the copper displacement reaction following a change in the concentration of copper ions in the solution and in the pH of the sulfosalicylate solution is given. A decrease in the contact exchange rate is facilitated by a decrease in the concentration of copper ions in solution and their participation in the formation of complexes.     

ESR方法检测竹红菌素的半醌负离子自由基

从顺磁共振波谱检测到通过竹红菌素的光诱导还原和基态竹红菌素跟脂肪胺的电子转移两条途径所得到的自由基信号, 并由电化学还原得到同一自由基, 确认它为半醌负离子自由基。竹红菌素溶液中加入芳香胺观察不到ESR信号。它的3,10位上与醌基相邻近的羟基离解以后, 无论在基态还是在激发态都观察不到ESR信号。此外, 还从吸收光谱观察到半醌负离子自由基吸收以及竹红菌素跟脂肪胺之间的相互作用。     

Changes in density and surface tension of water in silica pores

 The density and surface tension of water in small pores of silicas have been investigated. These physical properties of water in the pores were calculated from a comparison of pore volumes and pore radii which were estimated from adsorption and desorption isotherms of nitrogen and water. Below a pore radius of about 5 nm both the density and the surface tension of water in the pores were smaller than those of the bulk liquid and decreased with a decrease in pore size. The density of water in the pores decreased with an increase in the concentration of surface hydroxyl groups. Similarly the surface tension of water in the pores is influenced by the surface hydroxyl groups. Anomalous changes in the density and surface tension of the water in the pores are attributed to the interaction of water molecules with surface hydroxyl groups and hydrogen-bond formation among water molecules. Received: 20 April 1999 Accepted in revised form: 17 November 1999     

The Behavior of Trivalent and Pentavalent Methylarsenicals in Lake Biwa

Seasonal changes in the distribution of arsenic species were observed in a dredged area in the southern basin of Lake Biwa, Japan. The concentrations of dimethylarsenic acid [DMAA(V)] became comparable with those of inorganic forms during a stratification period. DMAA(V) increased not only in the photic zone but also in the hypolimnion. In the photic zone, an increase in DMAA(V) was observed with the yearly maximum of water temperature. In the hypolimnion, the seasonal changes in methylarsenicals differed from those in surface waters. DMAA(V) maxima appeared seasonally under sub-anoxic conditions and developed regionally at the redox boundary and above the sediment surface. The DMAA(V) concentrations increased in the initial period of oxygen depletion and just after the disappearance of anoxia, while they diminished in the anoxic hypolimnion by midsummer. The seasonal behavior of trivalent methylarsenicals, which are readily oxidized in oxic environments, was similar to that of DMAA(V). The total arsenic concentration in the surface layer rose to a maximum in late summer. Methylarsenicals did not increase in such a way that the total arsenic concentration increased during summer. © 1997 by John Wiley & Sons, Ltd.     

Analysis of sequence repeats of proteins in the PDB

Internal repeats in protein sequences play a significant role in the evolution of protein structure and function. Applications of different bioinformatics tools help in the identification and characterization of these repeats. In the present study, we analyzed sequence repeats in a non-redundant set of proteins available in the Protein Data Bank (PDB). We used RADAR for detecting internal repeats in a protein, PDBeFOLD for assessing structural similarity, PDBsum for finding functional involvement and Pfam for domain assignment of the repeats in a protein. Through the analysis of sequence repeats, we found that identity of the sequence repeats falls in the range of 20–40% and, the superimposed structures of the most of the sequence repeats maintain similar overall folding. Analysis sequence repeats at the functional level reveals that most of the sequence repeats are involved in the function of the protein through functionally involved residues in the repeat regions. We also found that sequence repeats in single and two domain proteins often contained conserved sequence motifs for the function of the domain.     

汽油铅与血铅的关系

论述了汽油铅对人体血铅水平的影响，主要内容包括：血铅水平与大气铅水平的关系，大气铅水平与加铅汽油耗量的关系，汽油铅耗量与居民血铅水平的关系。     

The Effect of Antiretroviral Therapy on SIRT1, SIRT3 and SIRT6 Expression in HIV-Infected Patients

Human Immunodeficiency Virus (HIV) infection and the chronic use of combined antiretroviral therapy (cART) may affect the occurrence of certain disturbances in the body. There is growing interest in sirtuins–enzymes involved in the regulation of many metabolic processes in the organism and in the pathogenesis of many diseases which also exhibit potential antiviral activity. The aim of the study was to investigate the connection of cART to the expression of Sirtuin 1 (SIRT1), Sirtuin 3 (SIRT3) and Sirtuin 6 (SIRT6) in HIV-infected men. The plasma levels of sirtuins were measured before and one year after cART, and related to HIV viral load, lymphocytes T CD4+ and CD8+ count as well as the applied cART. The levels of sirtuins in plasma were measured in HIV-infected patients (n = 53) and the control group (n = 35) by immunoassay methods. There were statistically significant (p < 0.05) differences between SIRT6 in the HIV-infected patients before therapy and in the subgroups, depending on the count of lymphocytes T CD8+. There were significant differences in the levels of SIRT1 depending on the applied treatment regimen. The obtained results indicate the most significant changes in the expression of SIRT6 in the course of HIV infection and suggest an influence of the type of cART on the level of SIRT1, which indicates its important role in the course of HIV.