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《分析试验室》2015,(11)
生命体内许多重要的巯基小分子,如半胱氨酸(Cysteine,Cys)、同型半胱氨酸(Homocysteine,Hcy)和还原谷胱甘肽(Glutathione,GSH)等,在维持生命体系中的氧化还原平衡发挥着重要作用。因此,定量检测和专一性识别巯基生物分子在生物医学研究中具有非常重要的意义。荧光分析法具有操作简便、灵敏度高、选择性好、实时检测以及对生物体损伤小等优点而受到广泛关注。双光子荧光探针技术相对于单光子荧光技术具有长波吸收,短波发射、高度的三维空间选择性、大的穿透深度、避免荧光漂白和光致毒以及降低组织自发荧光干扰等特点,在生命科学领域具有广阔的应用前景。介绍了有机单光子和双光子巯基小分子荧光探针的研究现状,同时展望了有机巯基小分子荧光探针未来的研究方向。 相似文献
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菁染料是一种商品化的近红外荧光染料, 其光谱范围位于近红外区域, 此光谱区域内生物基体光吸收或荧光强度较小, 因此利用菁染料对生物体进行成像, 可以降低背景干扰. 吲哚七甲川菁染料是一类具有代表性的菁染料, 其由吲哚杂环、七甲川链和N-取代基侧链组成, 由于具有溶解性好, 最大吸收波长可调, 摩尔消光系数大等优良的光学性质, 被广泛用于肿瘤靶向治疗、蛋白标记、痕量金属离子检测等生物方面. 以吲哚七甲川为母体, 通过向母体中引入活性基团或改变它们的结构, 使探针具有不同的功能, 这已成为生物领域荧光成像的研究热点. 分别从检测金属阳离子、pH变化、小分子和靶向标记肿瘤细胞、蛋白质等方面综述了近年来用于生物体荧光成像的吲哚七甲川类荧光探针的研究进展, 其中也对荧光探针在生物体内(模型)分布、光学成像及代谢方面进行了介绍, 最后讨论了这类荧光探针存在的问题及发展趋势. 相似文献
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荧光成像凭借灵敏度高、特异性强等诸多优势在重大疾病的诊疗领域发挥着重要作用.然而传统的近红外一区(NIR-I,700~900 nm)荧光成像存在组织穿透性差等问题,限制了其临床应用.近红外二区(NIR-II,1000~1700 nm)荧光成像可以极大地减弱生物组织对光的吸收、散射和自发荧光,从而显著提升成像深度及成像效果.在众多NIR-II荧光探针中,有机小分子由于具有毒性低、代谢快等优点正成为该领域的研究热点.作者以近年来NIR-II有机小分子荧光探针的发展为主体,概括了提升探针荧光量子产率的策略,分别就可激活型、多模态成像型和诊疗一体化型NIR-II荧光探针进行分类讨论,系统介绍了近年来该领域内的研究成果,并针对NIR-II荧光探针未来的发展进行了展望. 相似文献
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近年来,随着生命科学的不断发展,人们对细胞内活性小分子在病理、生理等方面的功能研究越来越深入。荧光成像作为一种直观、原位的可视化观测技术在小分子检测方面得到了广泛应用,其中基于近红外分子与纳米探针的荧光成像技术因具有背景干扰低、对细胞损伤小、样品穿透性强、检测灵敏度高等优点,显示了较好的应用前景。本文评述了近年来近红外荧光探针用于细胞内活性小分子成像检测的应用及进展,主要讨论该类方法在活性氧物质、金属离子、H+、阴离子及巯基化合物的分析应用,并对该方法的应用前景进行了展望。 相似文献
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汞具有很强的生物毒性,会对人类的健康和环境造成极大危害.荧光探针具有高灵敏度、高选择性、可实时监测等优点,近年来在汞离子检测中广泛应用.由于小分子具有结构多样性、重复性好、易修饰、感应机制清晰等优点,目前许多检测汞离子的有机小分子荧光探针也已经被开发出来.根据探针与汞离子反应机制的不同,将其分为基于配位型反应和基于断键型反应两类,重点综述了近五年来用于检测汞离子的有机小分子荧光探针的研究进展.展望未来,利用特征性反应开发“Turn On”型的反应性探针,将是检测汞离子的有机小分子荧光探针研究中的重点方向. 相似文献
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小分子荧光探针应用于检测污染物具有高选择性、高灵敏度和可视化等优点,但其检测效率低,难以与本体分离回收,对环境有一定污染。通过化学方法将小分子荧光探针负载到介孔材料表面,可以克服小分子荧光探针的不足,实现小分子荧光探针和介孔材料的优势互补。基于介孔材料的荧光探针不但兼具了小分子荧光探针的识别及清除功能,还可以通过调整介孔材料孔径大小和孔材料的成分实现更低浓度的检测,提高检测的灵敏度。本文首先综述了近年来基于介孔材料的不同类型荧光探针的研究进展,重点阐述荧光探针修饰的介孔材料在重金属离子检测、有机小分子检测、生物分子检测和阴离子检测等方面的应用,最后对基于介孔材料的荧光探针发展方向进行了展望。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献