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有机锗倍半硒化物的合成 总被引:1,自引:0,他引:1
根据有机锗倍半氧(硫)化物具有明显抗癌活性和硒与肿瘤发病率的密切负相关关系,设计并合成了四个新的有机锗倍半硒化物,期望获得有更显著抗癌活性的化合物,对有机锗倍半氧,硫和硒化物的红外光谱进行了比较,发现Ge-X(X=O,S和Se)红外吸附峰符合振动波数(cm^-1)与原子量成反比的变化规律。 相似文献
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合成有机锗倍半硫化物的新方法 总被引:5,自引:0,他引:5
有机锗倍半硫化物的合成是有机锗抗癌药物研究中的热点之一。在路易斯碱(如吡啶或三乙胺)存在下,经有机锗三氯化物溶液中通干燥的硫化氢气体制得有机锗倍半硫化物的方法有许多缺点,如无法计算吸收的硫化氢的量、设备复杂、操作困难并产生硫化氢臭味和毒性。我们用无水硫化钠直接与有机锗三氯化物作用即可得到有机锗倍半硫化物。利用此法合成了8种有机锗倍半硫化物: 相似文献
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Kifunensine是一种从名为Kitasatosporia kifunense的放线菌中分离出来的生物碱,它是一种中性,稳定的化合物,同时也是甘露糖苷酶I的有效抑制剂,目前被广泛地用于药物研发领域,具有非常高的商业价值,但是它的合成制备非常困难,存在收率低、合成成本高等问题。本文对其合成方法进行了研究,以廉价易得的L-古洛糖酸-γ-内酯为原料,经过一系列转化得到Kifunensine,该操作中多个步骤可以用一锅法投料,操作简便,总产率为4.8%,该方法为该化合物的大规模制备提供了新的思路。 相似文献
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乳化剂在双重乳液合成含胰岛素纳米胶囊中的作用 总被引:2,自引:0,他引:2
Insulin entrapped nanocapsules to use polylactide (PLA) as the encapsulating material were prepared through a modified water-in-oil-in-water (W/O/W) emulsification and solvent evaporation method, The average particle size of PLA nanocapsules obtained was decreased to (181.5 ± 8.4) nm, and capably adjusted from 180 to 370 nm by using different types and content of nonionic emulsifiers. The influence of emulsifiers on property of nanocapsules was discussed in detail. The effects of spans and tweens to modify the size of the nanocapsules were different, which can be due to the distribution of the surfactants on the inner interface between the inner water and oil of the double emulsion. The encapsulation efficiency and drug release of nanocapsules were affected obviously by the content and type of emulsifiers. 相似文献
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某些有机锗倍半氧化物的合成及活性研究 总被引:1,自引:0,他引:1
某些有机锗倍半氧化物的合成及活性研究曾强,曾宪顺,崔涛(南开大学元素有机化学研究所,天津300071)范继能(四川师范学院化学系,南充637002)Ge-132及其类似物具有广泛的药理活性[1],作为药物或辅剂,其主要特点是毒性低。其中一大类倍半氧锗... 相似文献
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《Analytical letters》2012,45(19):1509-1523
Abstract A highly sensitive sandwich enzyme immunoassay for insulin in human serum has been developed using capybara anti-insulin serum. Capybara anti-insulin IgG-coated polystyrene balls were incubated with serum samples in the presence of 0.4 M NaCl and then with capybara anti-insulin Fab'-horseradish peroxidase conjugate. The peroxidase activity bound to the polystyrene balls was correlated to the amount of insulin to be assayed. Serum interference was eliminated by the presence of 0.4 M NaC1, and there was no need to add insulin-free serum to a standard curve. The sensitivity was 4 nU/tube or 0.2 μU/ml of serum when 20 μ1 of serum samples was used. The recovery of insulin added to human serum was 92–97 %. The coefficients of within-assay and between-assay variations were 5.1–7.2 % and 7.6–9.2 %, respectively. The regression equation and correlation coefficient to radioimmunoassay were Y(EIA)=0.91×(RIA)-2.4 and 0.97 (n=76), respectively. 相似文献
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BAO Yong-li JIANG Hong-yu Ji Shou-xian WU Yin MENG Xiang-ying LI Yu-xin 《高等学校化学研究》2006,22(2):229-232
Introduction Insulinisbestknownforitsactiononperipheral insulintargettissuessuchastheadipocyte,muscleand liverinordertoregulateglucosehomeostasis.Sincethe mid1990s,datahavebeenaccumulatedonthein volvementofbraininsulinincognitiveprocesses,and atpresentiti… 相似文献
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《Analytical letters》2012,45(4):672-681
Insulin plays an important role in glucose metabolism and its detection in biological fluids is of interest. In this study, a triple-helix molecular switch was employed for the simple, sensitive, and rapid determination of insulin. The triple-helix molecular switch was composed of a target specific aptamer sequence flanked by two arm segments and a dual-labeled oligonucleotide acting as a signal transduction probe. This approach takes advantage of unique properties of aptamers and triple-helix molecular switches such as high affinity, selectivity, and stability. In the absence of insulin, the fluorescence of triple-helix molecular switch is on. Upon addition of insulin, the aptamer binds to its target, leading to the release of the signal transduction probe, folding of the signal transduction probe to a stem loop structure, and the quenching of the fluorescence. This sensor showed a high selectivity toward insulin and a limit of detection as low as 9.97 nM. The sensor was employed for the determination of insulin in biological samples. This platform may be generalizable for a variety of molecules. 相似文献
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猪胰岛素的活力位置的电子结构分析 总被引:1,自引:0,他引:1
叶元杰 《高等学校化学学报》1993,14(6):812-816
本文采用负因子计数方法对猪胰岛素分子作了完整分子的量子化学计算,其中对矩阵元的计算采用EHMO方法。我们将前线轨道的概念推广为靠近Fermi能级的能量区域中的分子轨道,将局域于少数氨基酸残基上的前线轨道简称为活性轨道。计算结果表明,猪胰岛素70%的活力敏感位置上局域有活性轨道。对全部结果的分析说明猪胰岛素的活性轨道和生物活力之间存在某些内在联系,但不是一一对应关系;猪胰岛素的三级构象的变化可以引起电子结构的变化;相同种类的氨基酸残基在分子的不同位置上可以有不同的活性轨道能级和轨道分布。 相似文献
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胰岛素分子间的相互作用是人们所关心的一个课题,它对探讨胰岛素及其类似物与受休的相互作用和它们在溶液中的行为有着重要的意义,本文在前文工作的基础上,计算了两个胰岛素分子在不同距离和不同取向时的相互作用能,并试图对上述问题的研究提供线索。 我们从胰岛素两聚体的晶体结构数据出发,找出两个单体分子相距最近的三对点,求其中点坐标,在过该三点的平面上作一条垂线,作为分子间平移和转动的参考轴,固 相似文献
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对蛋白质分子进行量子化学计算常采用如下方法:以肽基和残基侧链为基本计算单元,使对蛋白质分子的计算分解成各次单元的计算(图10)。计算时往往根据构象图选择代表点以减少工作量。例如,计算木瓜蛋白酶时,根据其构象图,212个肽基被分为10组,每组中选取1个代表点进行计算。用同样的方法处理残基侧链的计算。但该方法 相似文献
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LI Wei Introduction In1986,Geysen[1]foundthatshortpeptidescon tainingthekeyresiduesofaproteincanmimicthede terminantoftheprotein;mostofthebindingenergybe tweenproteinsresultsfromthenoncovalentinteractions ofsomekeyresidues.Thesesmallpeptidesgenerally have… 相似文献
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Yun Liu Yanfang Wang Yuejun Yao Juan Zhang Wei Liu Kangfan Ji Xinwei Wei Yuanwu Wang Prof. Xiangsheng Liu Prof. Shiming Zhang Prof. Jinqiang Wang Prof. Zhen Gu 《Angewandte Chemie (International ed. in English)》2023,62(20):e202303097
Lipid nanoparticle-based drug delivery systems have a profound clinical impact on nucleic acid-based therapy and vaccination. Recombinant human insulin, a negatively-charged biomolecule like mRNA, may also be delivered by rationally-designed positively-charged lipid nanoparticles with glucose-sensing elements and be released in a glucose-responsive manner. Herein, we have designed phenylboronic acid-based quaternary amine-type cationic lipids that can self-assemble into spherical lipid nanoparticles in an aqueous solution. Upon mixing insulin and the lipid nanoparticles, a heterostructured insulin complex is formed immediately arising from the electrostatic attraction. In a hyperglycemia-relevant glucose solution, lipid nanoparticles become less positively charged over time, leading to reduced attraction and subsequent insulin release. Compared with native insulin, this lipid nanoparticle-based glucose-responsive insulin shows prolonged blood glucose regulation ability and blood glucose-triggered insulin release in a type 1 diabetic mouse model. 相似文献