共查询到19条相似文献,搜索用时 62 毫秒
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分子识别是生物体系的基本特征,并在生命活动中起中心作用。生物酶高效专一地催化生化反应,抗体与抗原的结合,蛋白质分子与DNA序列的相互作用等都源于精确的分子识别[1,2]。利用合成的人工受体与适当底物之间的分子识别以建立仿生仿酶模型的研究,已成为生物有机化学前沿富有挑战性的领域。分子裂缝作为一类新型的人工受体,以其灵活的结构以及易于将功能团聚集在受体与底物结合的活性部位上等优点,引起了人们的广泛关注[3-5]。胆甾因其具有刚性的凹面结构和天然的手性,是构筑分子裂缝人工受体的理想结构单元。我们曾报道3α-OH和7α-OH同… 相似文献
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新的席夫碱型鹅去氧胆酸分子钳的微波无溶剂合成 总被引:1,自引:0,他引:1
在微波辐射无溶剂条件下,以鹅去氧胆酸甲酯为隔离剂,通过氨基与不同芳香醛缩合合成了十个含席夫碱结构单元为手臂的新型鹅去氧胆酸分子钳.通过微波法和常规法的对比发现,使用微波法后,产率从30%~75%提高到85%~94%,反应时间从300~480 min缩短到0.5~1.5 min.所有合成化合物的结构均经1H NMR,IR,ESI-MS和元素分析确证.利用紫外光谱滴定法考察了其对分子的识别性能研究.实验结果表明,这类分子钳人工受体对有机小分子具有良好的识别能力. 相似文献
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高效液相色谱法测定牛黄解毒片中胆酸和猪去氧胆酸的含量及其质量分析 总被引:1,自引:0,他引:1
建立高效液相色谱法测定牛黄解毒片中胆酸和猪去氧胆酸的含量的方法,分析不同厂家、不同批次牛黄解毒片中这两种成分的差异.选用Welch Ultimate LP–C18柱(250 mm×4.60 mm,5μm)为分离柱,流动相为甲醇–乙腈–0.1%甲酸溶液(体积比为63:17:20),流量为0.8 mL/min,柱温为30℃... 相似文献
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《Radiation Physics and Chemistry》2009,78(4):244-250
Phenylacetylene was polymerized as inclusion compound (clathrate) inside deoxycholic acid (DOCA) crystals. The polymerization was initiated by γ radiation and a total dose of 320 kGy was employed. The resulting polyphenylacetylene (PPA) was isolated by dissolution of deoxycholic acid in boiling ethanol. PPA high polymer was accompanied by a series of phenylacetylene oligomers, which were detected by liquid chromatographic analysis (HPLC). PPA was characterized by electronic absorption spectroscopy and by FT-IR spectroscopy in comparison to a reference PPA prepared by a stereospecific catalyst. The microstructure of PPA from inclusion polymerization was highly trans type, similar to that observed on PPA prepared by bulk radiolysis. No optical activity was detected by polarimetry on PPA prepared by inclusion polymerization.The host–guest complex PPA/DOCA was studied by differential thermal analysis (DTA) and by thermogravimetry (TGA). DTA provided evidences of the host–guest complex formation from the shift of the melting point of DOCA while the TGA confirmed the identity – in terms of thermal behaviour – of the PPA from inclusion polymerization with that from stereospecific polymerization. 相似文献
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Three monomeric and three dimeric deoxycholic acid (DCA) alkylamido-phenylurea derivatives are designed based on known gelators and are synthesized and characterized by 1H and 13C NMR spectroscopy, ESI-TOF mass spectrometry, and elemental analyses. Among them, a monomeric derivative forms supramolecular gels in CHCl3 and chlorobenzene, whereas a dimeric derivative gels THF and higher 1-alkanols containing 7-10 carbons. The morphologies of their xerogels are studied by scanning electron microscopy (SEM). No signature of macroscopic chirality of the gels is visible. 相似文献
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The reaction of 3-aminopropylamide of cholic acid with CS? produced a bile acid derivative of dithiocarbamic acid which further formed an ammonium salt with another molecule of 3-aminopropylamide of cholic acid. The cationic 3-ammonium propylamide of cholic acid did not react further with CS? and the formed salt was stable in the reaction mixture, even when excess CS? was used. When the reaction was carried out in the presence of aqueous sodium hydroxide, only the bile acid derivative of sodium dithiocarbamate was formed. The dithiocarbamate derivatives were characterized by 1H- and 13C-NMR spectroscopy and ESI-TOF mass spectrometry. 相似文献
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Cynthia J. Burrows Richard A. Sauter 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(1):117-121
New synthetic hosts have been designed incorporating two molecules of cholic acid linked by a rigid diamine. Proton NMR studies indicate that the compounds exist in a rigid conformation with the steroid hydroxyl groups intramolecularly hydrogen-bonded. Heat or addition of methanol leads to conformational isomerism due to insertion of methanol into the cavity.A preliminary report of this work was presented at the 4th International Symposium on Inclusion Phenomena, July 20–25, 1986, Lancaster, U.K. 相似文献
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We wish to report here a new and efficient partial synthesis of 3-oxa-5β-steroid, the first oxa steroid synthesized from cholic acid. 相似文献
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M. V. Veselovska M. M. Garazd O. S. Ogorodniychuk Ya. L. Garazd V. P. Khilya 《Chemistry of Heterocyclic Compounds》2008,44(2):153-162
Sulfur-and nitrogen-containing derivatives of spirodihydropyranochromen-2-ones at the exocyclic oxygen atom have been synthesized.
Modification of the oximes and hydrazones of the spiro-substituted pyranocoumarins with N-substituted amino acids were carried
out using activated ester and symmetrical anhydride methods.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 208–220, February, 2008. 相似文献