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喜树碱结构与活性的关系 总被引:2,自引:0,他引:2
喜树碱是从我国特有植物喜树中分离得到的。它是一种广谱抗癌药物,对多种肿瘤有疗效,但同时也有副作用。为了寻找一种既具抗癌活性,毒性又小的喜树碱类似物,国外学者对喜树的五个环分别进行了修饰,并对修饰产物进行了药理研究,找到了抗癌活性与结构之间的关系。本文着重介绍他们的研究结果并简要总结一下喜树碱的结构、性质。 相似文献
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喜树碱(Camptothecin,CPT)是美国化学家Wall和Wani在1966年首先从中国珙桐科植物喜树(Camptothecaacuminata)中提取出来的一种生物碱.试验表明它对许多实体瘤有抗肿瘤活性.药物学家对喜树碱分子的结构修饰,大多数集中在喜树碱的A,B和E环上.喜树碱的C环上5-位取代往往降低活性.我们在制备喜树碱烷基化衍生物过程中发现,喜树碱及其衍生物在碳酸钾和活泼溴代烷作用下得到5-位烷基化产物,用不同的溴代烷分别得到单取代或双取代产物.我们合成的5-位烷基化的喜树碱衍生物经过人肿瘤细胞(KB,KB/VCR,A549,HCT-8,Bel7402,A2780)的体外筛选实验,表明这一类化合物细胞毒性显著降低甚至丧失,这可能是因为取代基的空间位阻作用影响了D环羰基和受体的结合. 相似文献
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选择天然产物齐墩果酸进行炔基化修饰(OA-alkyne),与环金属铱前体CycloIr-N3在铜催化条件下发生叠氮-炔环加成(CuAAC)反应,得到新的环金属铱配合物CycloIr-OA,通过1H NMR、ESI-MS对配体及配合物进行了表征。配合物具有良好的脂溶性,可以快速进入细胞。用MTT法、激光共聚焦成像及流式细胞术对CycloIr-OA的抗肿瘤活性和抗癌机制进行了研究。结果表明,连接齐墩果酸后,配合物CycloIr-OA的抗癌活性有较大提升。CycloIr-OA富集在肿瘤细胞的线粒体中,导致活性氧产生,同时将细胞周期阻滞在S期,最终诱导肿瘤细胞坏死。 相似文献
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《Journal of Coordination Chemistry》2012,65(3):187-191
Abstract The kinetics of Cr2+(aq) reductions of glycinato-, D,L-alanato, D,L-phenylalanato-, and D,L-leucinatobis-(ethylenediamine)cobalt(III) ions have been investigated. The rate law is of the form d(ln[Co(III)]/dt = k[Cr2+], where the rate constant k(M?1sec?1) and associated activation parameters δHδ(kcal mol?1 and δSδ (cal deg ?1mol?1) in parentheses, are respectively 1.65 · 0.06 (9.7 · 0.1, -25 · 1), 0.367 · 0.008 (10.9 · 04,-24 ·1), 0.529 · 0.021 (11.2 · 0.4, -22 · 1); and 0.358 · 0.019 (11.5 · 0.3, -22 · 1) at 298·K and ·[CIO·] = 1.0 M. The reactions are all inner-sphere. 相似文献
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Fifteen of the bichromophore compounds containing oxazole or oxidation ring have been synthesized. Their structures have been identified by IR, 1H NMR spectra and elemental analysis. The UV spectra, fluorescence spectra and the laser conversion efficiencies have been determined . The results of determination show that the absorption and emission spectra Pf the bichromophore compounds are different from those of the corresponding single chromophore compounds. 相似文献
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Alexander V. Butin Artem S. Dmitriev Maxim G. Uchuskin Vladimir T. Abaev Igor V. Trushkov 《合成通讯》2013,43(10):1569-1578
A simple transformation of 2‐alkylfurans and 2‐formylbenzoic acids into 4‐unsubstituted 3‐(3‐oxoalkyl)isocoumarins is described. It is based on the synthesis of 2‐(2‐carboxybenzyl)furans followed by their acid‐catalyzed recyclization to the target isocoumarins. 相似文献
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Lara Bianchi Dr. Gianluca Giorgi Prof. Massimo Maccagno Dr. Giovanni Petrillo Prof. Fernando Sancassan Prof. Elda Severi Dr. Domenico Spinelli Prof. Marco Stenta Dr. Cinzia Tavani Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(4):1312-1318
When Ar is a low‐aromaticity homo‐ or heterosystem, the sulfonyl‐stabilized anion of nitrobutadienes 4 (which derive from the initial ring opening of 3‐nitrothiophene) undergoes a rather surprising addition onto the aromatic ring itself, thereby leading to the construction of an unusual eight‐membered sulfur heterocycle condensed with the original Ar ring. The competitiveness of such a pathway with respect to the formation of the thiopyran ring (i.e., addition onto the nitrovinyl moiety) is favored at low temperatures, thus revealing its nature as a kinetically controlled process. 相似文献
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Dr. Lambert Sicard Fabien Lucas Dr. Olivier Jeannin Dr. Pierre-Antoine Bouit Dr. Joëlle Rault-Berthelot Dr. Cassandre Quinton Dr. Cyril Poriel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):11159-11165
For the last ten years, ring-shaped π-conjugated macrocycles possessing radially directed π-orbitals have been subject to intense research. The electronic properties of these rings are deeply dependent on their size. However, most studies involve the flagship family of nanorings: the cyclo-para-phenylenes. We report herein the synthesis and study of the first examples of cyclofluorenes possessing five constituting fluorene units. The structural, optical and electrochemical properties were elucidated by X-ray crystallography, UV-vis absorption and fluorescence spectroscopy, and cyclic voltammetry. By comparison with a shorter analogue, we show how the electronic properties of [5]-cyclofluorenes are drastically different from those of [4]-cyclofluorenes, highlighting the key role played by the ring size in the cyclofluorene family. 相似文献
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Lambert Sicard Fabien Lucas Olivier Jeannin Pierre‐Antoine Bouit Joëlle Rault‐Berthelot Cassandre Quinton Cyril Poriel 《Angewandte Chemie (International ed. in English)》2020,59(27):11066-11072
For the last ten years, ring‐shaped π‐conjugated macrocycles possessing radially directed π‐orbitals have been subject to intense research. The electronic properties of these rings are deeply dependent on their size. However, most studies involve the flagship family of nanorings: the cyclo‐para‐phenylenes. We report herein the synthesis and study of the first examples of cyclofluorenes possessing five constituting fluorene units. The structural, optical and electrochemical properties were elucidated by X‐ray crystallography, UV‐vis absorption and fluorescence spectroscopy, and cyclic voltammetry. By comparison with a shorter analogue, we show how the electronic properties of [5]‐cyclofluorenes are drastically different from those of [4]‐cyclofluorenes, highlighting the key role played by the ring size in the cyclofluorene family. 相似文献
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Dr. Jing Shang Dr. Varsha J. Thombare Dr. Carlie L. Charron Prof. Uta Wille Prof. Craig A. Hutton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(5):1620-1625
The AgI-promoted reaction of thiolactams with N-Boc amino acids yields an N-(α-aminoacyl) lactam that can rearrange through an acyl transfer process. Boc-deprotection results in convergence to the ring-expanded adduct, thereby facilitating an overall insertion of an amino acid into the thioamide bond to generate medium-sized heterocycles. Application to the site-specific insertion of amino acids into cyclic peptides is demonstrated. 相似文献
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