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141.
WEI Xiaolan* & SHEN Peikang State Key Laboratory of Optoelectromic Materials Technologies School of Physics Engineering Sun Yat-Sen University Guangzhou China Department of Applied Chemistry South China University of Technology Guangzhou China. 《中国科学B辑(英文版)》2005,48(6):511-515
Approaches for preparation of porous oxides with different length scales are currently available[1?3]. Materials with hierarchical pore systems at two or three different length scales have also been prepared[4?7]. Such materials are important both for the… 相似文献
142.
Qian Feng WENG Wen Rui JIN* School of Chemistry Chemical Engineering Shandong University Jinan 《中国化学快报》2002,13(10)
Capillary electrophoresis (CE) has become a useful and powerful separation technique and has many applications. Electrochemical detection (ED) has been shown to be one of the most sensitive detection techniques available for use in CE. Dual-electrode detection can expand the applicability of CE-ED1-5, the materials such as gold/mercury1,3, carbon fiber2, Pt4 and Au3,5 have been used for the two electrodes in dual-electrodes. As is well known, the electrochemical response of different c… 相似文献
143.
Man LU Jian Guo FANG Zhong Li LIU Long Min WU* National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(10)
Nitroxides have been found to be the intermediate in the in vivo metabolism of hydroxamic acid, a well-known biological molecule1. Structural modification of some antitumor drugs by introducing nitroxides can lower toxicity remarkably with retention or even increase of the antitumor activity2. Furthermore, the use of nitroxides as spin probes makes it possible to get information regarding the microenvironment of the reaction. 4-Substituted Hantzsch 1,4-dihydropyridines (DHP) are analogs … 相似文献
144.
Qian Feng WENG Wen Rui JIN* School of Chemistry Chemical Engineering Shandong University Jinan 《中国化学快报》2002,13(10)
Sensitive and selective methods for the detection of amino acids (AAs) in single cells are of increasing importance. Capillary zone electrophoresis (CZE) with electrochemical detection (ED) is suitable for analysis of electroactive contents in single cells. However, most native AAs have no electroactivity. Derivatization with an electroactive tag is an attractive method. An on-capillary derivatization scheme was reported1. Naphtha- lene-2, 3-dicarboxaldehyde (NDA) can react with pri… 相似文献
145.
An Pai LI Hui WANG Cheng Lu ZHANG Tong Xing WU Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(2)
Hypargenin B, a diterpene with the abietane skeleton, was isolated by Ayhan from the root of an endemic species salvia hypargenia and showed antibacterial activity1. In this diterpene, the junction of A/B ring is trans. In order to provide for studying further the relationship between the structure and bioactivities, we develop a novel route whereby the hypargenin B methyl ether 22 could be obtained in good yield. To our knowledge no total synthetic work has been reported on the title com… 相似文献
146.
Han LIANG Jing Jian LI* Xiao Dong LI Fei Li TANG Gu YUAN* Department of Chemistry Peking University Beijing The Key Laboratory of Bioorganic Chemistry Molecular Engineering Department of Chemical Biology Peking University Beij 《中国化学快报》2002,13(10)
Distamycin is a naturally occurring antibiotic which binds to the AT rich regions in minor groove of DNA1. We have reported the interaction between the analogs and calf thymus DNA by circular dichroism spectropolarimetry (CD) and isothermal titration calorimetry (ITC)2. Due to the greater sensitivity of fluorescence-based techniques in comparison with CD, we employ the fluorimety to explore the interaction between four new distamycin analogs and DNA from herring sperm. O2NNNOHNNO… 相似文献
147.
Jun MA Qing Yang FENG Liang He SHI Jian XU* State Key Laboratory of Polymer Physics & Chemistry Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 《中国化学快报》2002,13(1):75-78
The term polysilsesquioxanes in this paper refers to all structures with the empiri-cal formulas (RSiO3/2)n where R is hydrogen or any alkyl, alkylene, aryl, arylene, or organo-functional derivatives of alkyl, alkylene, or aryl. Polymethylsilsesquioxane (PMSQ) is characterized by its low weight loss at high temperatures. X-ray photoelectron spectroscopy (XPS) characterization of PMSQ was unavailable from reported literatures. In this study, the pyrolysis was carried out in an inert at… 相似文献
148.
Jun Gui DAI Meng ZHANG Min YE Wei Hua ZHU Ji Yu GUO Xiao Tian LIANG* Institute of Materia Medica Chinese Academy of Medical Science & Peking Union Medical College Beijing 《中国化学快报》2003,14(8)
Sinenxan A, 2a, 5a, 10b,14b-tetraacetoxy-4(20),11-taxadiene, is a taxoid isolated from the callus cultures of Taxus spp. in high yield (ca. 1~2% of dry weight)1,2. The rich resources and its taxane-skeleton vest it valuable potential for the semisynthesis of paclitaxel or other structurally related bioactive compounds, such as 搒econd -generation?taxoid anticancer agents and taxane-based multidrug resistant anticancer agents3-5. Many remarkable studies on its structural modification by chemi… 相似文献
149.
Zhi Hua MA Cong LIU Yong Hua ZHAO Wei LI Jian Bo WANG* Key Laboratory of Bioorganic Chemistry Molecular Engineering of Ministry of Education Department of Chemical Biology College of Chemistry Peking University Beijing 《中国化学快报》2002,13(8)
b-Amino acids and their derivatives have attracted considerable attention in recent years due to their occurrence in biologically active natural products, such as dolastatins 11, cyclohexylnorstatine 22 and taxol 33. bAmino acids also find application in the synthesis of blactams4, piperidines5, indolizidines6. Moreover, the peptides consisting of bamino acids, the so called bpeptides, have been extensively studied recently7. Consequently, considerable efforts have been directed to the synt… 相似文献
150.
JIAO Qing ze ZHAO Yun LI Xiao dan EVANS D. G. DUAN Xue * Key Laboratory of Science Technology of Controllable Chemical Reactions Ministry of Education Beijing University of Chemical Technology Beijing P. R. China 《高等学校化学研究》2002,18(2)
IntroductionGlycolethersareimportantindustrialderivativesofepoxides .Polyethylene glycolethylethersandpolypropyleneglycolethylethersaretwoimportantseriesofproducts .Glycolethersaregoodsolventsduetothepresenceof—O—and—OH groups.Asare sult ,theyarewidelyuse… 相似文献