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Task specific ionic liquids and onium salts have been used as soluble supports for peptide synthesis. These new supports combine easy monitoring, high loading capacities, large scale preparation, and homogeneous kinetics characteristics while keeping advantages of solid-phase synthesis including easy purification and workup. Careful structural design of these supports allowed for fine tuning of physical properties leading to better yields, kinetics, and purities. 相似文献
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Raymond Wai‐Yin Sun Dr. Carrie Ka‐Lei Li Dr. Dik‐Lung Ma Dr. Jessie Jing Yan Chun‐Nam Lok Dr. Chung‐Hang Leung Dr. Nianyong Zhu Dr. Chi‐Ming Che Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(10):3097-3113
In the design of physiologically stable anticancer gold(III) complexes, we have employed strongly chelating porphyrinato ligands to stabilize a gold(III) ion [Chem. Commun. 2003 , 1718; Coord. Chem. Rev. 2009 , 253, 1682]. In this work, a family of gold(III) tetraarylporphyrins with porphyrinato ligands containing different peripheral substituents on the meso‐aryl rings were prepared, and these complexes were used to study the structure–bioactivity relationship. The cytotoxic IC50 values of [Au(Por)]+ (Por=porphyrinato ligand), which range from 0.033 to >100 μM , correlate with their lipophilicity and cellular uptake. Some of them induce apoptosis and display preferential cytotoxicity toward cancer cells than to normal noncancerous cells. A new gold(III)–porphyrin with saccharide conjugation [Au(4‐glucosyl‐TPP)]Cl ( 2 a ; H2(4‐glucosyl‐TPP)=meso‐tetrakis(4‐β‐D ‐glucosylphenyl)porphyrin) exhibits significant cytostatic activity to cancer cells (IC50=1.2–9.0 μM ) without causing cell death and is much less toxic to lung fibroblast cells (IC50>100 μM ). The gold(III)–porphyrin complexes induce S‐phase cell‐cycle arrest of cancer cells as indicated by flow cytometric analysis, suggesting that the anticancer activity may be, in part, due to termination of DNA replication. The gold(III)–porphyrin complexes can bind to DNA in vitro with binding constants in the range of 4.9×105 to 4.1×106 dm3 mol?1 as determined by absorption titration. Complexes 2 a and [Au(TMPyP)]Cl5 ( 4 a ; [H2TMPyP]4+=meso‐tetrakis(N‐methylpyridinium‐4‐yl)porphyrin) interact with DNA in a manner similar to the DNA intercalator ethidium bromide as revealed by gel mobility shift assays and viscosity measurements. Both of them also inhibited the topoisomerase I induced relaxation of supercoiled DNA. Complex 4 a , a gold(III) derivative of the known G‐quadruplex‐interactive porphyrin [H2TMPyP]4+, can similarly inhibit the amplification of a DNA substrate containing G‐quadruplex structures in a polymerase chain reaction stop assay. In contrast to these reported complexes, complex 2 a and the parental gold(III)–porphyrin 1 a do not display a significant inhibitory effect (<10 %) on telomerase. Based on the results of protein expression analysis and computational docking experiments, the anti‐apoptotic bcl‐2 protein is a potential target for those gold(III)–porphyrin complexes with apoptosis‐inducing properties. Complex 2 a also displays prominent anti‐angiogenic properties in vitro. Taken together, the enhanced stabilization of the gold(III) ion and the ease of structural modification render porphyrins an attractive ligand system in the development of physiologically stable gold(III) complexes with anticancer and anti‐angiogenic activities. 相似文献
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Goran N. Kaluđerović Valentina Tayurskaya Reinhard Paschke Sanjiv Prashar Mariano Fajardo Santiago Gómez‐Ruiz 《应用有机金属化学》2010,24(9):656-662
The carboxylate compounds [Ti(η5‐C5H5)(η5‐C5H4{CMe2(CH2CH2CH?CH2)})(O2CCH2SXyl)2] (2; Xyl = 3,5‐Me2C6H3) and [Ti(η5‐C5H5)(η5‐C5H4{CMe2(CH2CH2CH?CH2)})(O2CCH2SMesl)2] (3; Mes 1 = 2,4,6‐Me3C6H2) were synthesized by the reaction of [Ti(η5‐C5H5)(η5‐C5H4{CMe2(CH2CH2CH?CH2)})Cl2] (1) with 2 equivalents of xylylthioacetic acid or mesitylthioacetic acid, respectively. Compounds 2 and 3 were characterized by spectroscopic methods. The cytotoxic activity of 1–3 was tested against human tumor cell lines from four different histogenic origins—8505C (anaplastic thyroid cancer), DLD‐1 (colon cancer) and the cisplatin sensitive A253 (head and neck cancer) and A549 (lung carcinoma)—and compared with those of the reference complex [Ti(η5‐C5H5)2Cl2] (R1) and cisplatin. Surprisingly, the cytotoxic activities of the carboxylate derivatives were lower than those of their corresponding dichloride analogue (1). However, complexes 1–3 were more active than titanocene dichloride against all the studied cells with the exception of complex 2 against A253 and A549 cell lines. DNA‐interaction tests were also carried out. Solutions of all the studied complexes were treated with different concentrations of fish sperm DNA, observing modifications of the UV spectra with intrinsic binding constants of 2.99 × 105, 2.45 × 105, and 2.35 × 105 M ?1 for 1–3. Structural studies based on density functional theory calculations of 2 and 3 were also carried out. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献