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Status of study on biological and toxicological effects of nanoscale materials

Science china chemistry 2005年第5期48卷 385-394页

作者： WANG Bing1, FENG Weiyue1, ZHAO Yuliang1, XING Gengmei1, CHAI Zhifang1, WANG Haifang2.& JIA Guang3 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, beijing 100049, china {2., peking university, beijing 100871, china 3. Department of Occupational and Environmental Health Sciences, School of Public Health, peking university, beijing 100083, china 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China 2. college of chemistry and molecular engineering Peking University 100871 Beijing China 3. Department of Occupational and Environmental Health Sciences School of Public Health Peking University 100083 Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

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Inhibitory effect of picroside Ⅱ on hepatocyte apoptosis

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Acta Pharmacologica Sinica 2005年第6期26卷 729-736页

作者： Hua GAO, Ya-wei ZHOU~2.college of chemistry and {2. engineering, peking university, beijing 100871, china college of chemistry and {2. engineering Peking University Beijing China

Aim: To investigate the influence of picroside on hepatocyte apoptosis and its mechanism. Methods: Morphological changes and quantification of apoptotic cells were determined under transmission electron microscopy and flow cytometry respectively. DNA fragmentation was visualized by agarose gel electrophoresis. Semi-quantitative reverse transcription-PCR (RT-PCR) was used to analyze the expression of bcl-2.and bax genes. The content of manganese-superoxide dismutase (SOD) in liver mitochondria was detected by the Marland method. The content of malonic aldehyde (MDA) and the protein level in liver tissue were determined by thiobarbituric acid colorimetry and Lowry method. Results: Picroside decreased the levels of alanine aminotransferase and aspartate aminotransferase in the serum resulting from acute-liver injured mice induced with D-GalN and LPS; it also reduced the content of MDA, and thus, enhanced the activity of SOD. Picroside 0 mg/kg was found to protect hepatocytes against apoptosis in a dose-dependent manner; it up-regulated the expression of bcl-2.genes, thus increased the bcl-2.bax ratio. Conclusion: Picroside 鈪an protect hepatocytes against injury and prevent hepatocytes from apoptosis. It might by upregulating the bcl-2.gene expression and antioxidation.

关键词： picroside Ⅱ hepatocytes apoptosis oxidative stress bcl-2.genes bax genes

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Synthesis and Crystal Structure of 4,6Di-tert-butyl-2.hydroxy-3-(N-1-phenylethyliminomethyl) phenyl bis(triphenylphosphine)palladium bromide

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Chinese Journal of Structural chemistry 1999年第4期18卷 54-59页

作者： XU JiaXi\ ZHANG ZeYing\= (college of chemistry and {2. engineering, peking university, beijing 100871, china) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａ... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＰａｌａｄｉｕｍｃｏｍｐｌｅｘｅｓｓｕｃｈａｓｔｅｔｒａｋｉｓ（ｔｒｉｐｈｅｎｙｌｐｈｏｓｐｈｉｎｅ）ｐａｌａｄｉｕｍａｒｅａｋｉｎｄｏｆｉｍｐｏｒｔａｎｔｃａｔａｌｙｓｔｓｉｎｔｈｅｒｅａｃｔｉｏｎｏｆｃａｒｂｏｎｃａｒ...

关键词： palladium complex synthesis molecular structure crystal structure

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STABILITY OF POLY(N,N'-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)MICROGEL DISPERSION AND ADJUSTMENT OF THE HYDROPHOBICITY IN THE MICROGELS

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Chinese Journal of Polymer Science 2005年第6期23卷 635-642页

作者： Qing-de Chen Xing-hai Shen and Hong-cheng Gao Department of Applied chemistry,college of chemistry and molecular engineering,peking university,beijing 100871,china peking Univ Dept Appl Chem Coll Chem & Mol Engn Beijing 100871 Peoples R China

In the UV-Vis spectra of pure light-scattering systems, there is an exponential relationship between absorbance and wavelength （A = Kλ^-n）. Here, the exponent n is named as flocculation-coagulation parameter. In the present paper, the effects of different additives on the stability of poly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine）（poly（Bis-co-4-VP）） microgel dispersion were studied in detail via this parameter. The results showed that the stability of the dispersion mainly comes from the ionization of pyridine groups, making the microgel positively charged on its surface. This was confirmed by the measurement of Zeta potential and the result of conductometric titration. The result of fluorescence analysis indicated that the hydrophobicity in the microgels is enhanced with the increase in total 4-VP unit content.

关键词： Microgel dispersion(s) 4-Vinylpyridine Flocculation-coagulation parameter Zeta potential

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EFFECTS OF L-PHENYLALANINE ON THE RADIATION SYNTHESIS OF POLY(N,N'-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)(MICRO)GELS

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Chinese Journal of Polymer Science 2005年第6期23卷 643-650页

The effects of L-phenylalanine （L-Phe） on the synthesis ofpoly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine）（poly（Bis-co-4-VP））（micro）gels by γ-ray irradiation were studied. The addition of L-Phe could not only decrease the gelation dose （Dg） of the synthesis obviously, but also transform the morphology of copolymer from microgel to gel. In addition, the swelling ability of the （micro）gels was also affected in the presence of L-Phe. The decrease of Dg was ascribed to the effect of pH, while the transformation of the morphology was ascribed to the effect of L-Phe on the stability of the poly（Bis-co-4-VP） microgel. Such an effect was confirmed further as compared with the effects of L-alanine, L-glutamic acid, L-arginine, sulfuric acid and aqueous ammonia.

关键词： L-Phenylalanine γ-Ray irradiation Gelation dose Morphology transformation (Micro)gel

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Synthesis,Structure and Antitumor Activities of Tridccapeptide PSPP3 from Papaver Somniferum Pollen

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Chinese Chemical Letters 1999年第2期10卷 115-116页

作者： Jia Xi XU Sheng JIN(college of chemistry and {2. engineering, peking university, beijing 100871) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

Five analogs and five segments of the Papavor Somniferum pollen tridecapeptidePSPP3 were designed and synthesized by using solid-phase peptide synthesis method. Theirinhibitive activities to human liver tumor cell Bel-7402.were assayed by MTT method and theirsecondary structures in solution were determined by CD spectra. The relationship of the structureand activity was discussed.

关键词： Pollen peptide anti-tumor activity structure and activity

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PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

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Chinese Journal of Polymer Science 2001年第4期19卷 371-376页

作者： Chen-yu Su Guang-li Zhang Hong-zhi Zhang Department of Polymer Science and engineering college of {2. and molecular engineering peking university beijing 100871, china peking Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3 degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2.00, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.

关键词： polyurethane poly(oxyethylene-co-oxytetramethylene) diol low temperature resilience heteropolyacid-ethylene oxide initiator system

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Antiviral compounds and one new iridoid glycoside from Cornus officinalis

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Progress in Natural Science:Materials International 2006年第2期16卷 142-146页

作者： WANG Yue, LI Zhengquan, CHEN Lirong and XU Xiaojie (college of chemistry and {2. engineering, peking university, beijing 100871, china) [a]college of chemistry and {2. engineering Piking University Beijing China

From Cornus officinalis Sieb. et Zucc., bioassay-guided fractionation led to the isolation of four active tannin compounds with high effectiveness of inhibiting Hepatitis C virus NS3 serine protease in vitro. The compounds are: 1,2.3, 6-tetragalloyl-β-D-glucopyranose (1), 1,2.3,4,6- pentagalloyl-β-D-glucopyranose (2., Tellimagrandin I (3) and Tellimagrandin II(4). The four compounds could inhibit HCV NS3 protease in vitro with IC50 values of 6.98, 5.11, 7.0 and 4.8μmol/L respectively. In addition, a new iridoid glycoside (5) was also isolated from Cornus officinalis Sieb. et Zucc., which was assigned to be 7-O-butyl morroniside by spec-troscopic analysis.

关键词： inhibitor HCV NS3 protease iridoid glycoside Cornus officinalis Sieb. et Zucc.

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Biotic communities of the marine ecosystem in Meizhou Bay

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Journal of Environmental Sciences 1996年第1期8卷 48-56页

作者： Ren Jiuchang Cai Xiaoming (Center of Environmental Sciences,peking university,{2.,china)Chen Bin(college of Life Sciences, peking university,{2., china )Li Peng(college of chemistry and molecular engineering, peking university, Bei Ctr of Envmtl Sci Peking Univ Beijing China China

The current situation of biotic communities in Meizhou Bay is presented in this *** species composition,seasonal variation,and distribution of phytoplankton,zooplankton, red tide organisms,fishes,and benthos in Meizhou Bay were investigated,and the content of chlorophyll a and primary production and their seasonal variation were also *** water quality of Meizhou Bay was monitored by measuring the density of Escherichia coli. Results reveal that there is a great variety of species in Meizhou Bay and the water in Meizhou Bay is *** the individual numbers of various organisms are very low, especially those of ***,there are more than 40 species of red tide organisms and there exist opportunities of red tides between May and *** these demand cautious be taken in the future development of this area although it has great environment capacity.

关键词： biotic community marine ecosystem Meizhou Bay.

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SYNTHESIS AND PROPERTIES OF NEW MESOGEN-JACKETED LIQUID CRYSTALLINE POLYMERS

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Chinese Journal of Polymer Science 2000年第2期18卷 139-148页

作者： Qi-ding Mi Qi-feng Zhou Department of Polymer Science & engineering, college of {2. peking university, beijing 100871, china peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

Some new mesogen-jacketed liquid crystalline polymers (MJLCP) with polymer backbones, spacers, and mesogenic units of different structures were synthesized by radical polymerization. The mesomorphic behavior of these polymers was examined using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Their liquid crystallinity is influenced by the variation of polymer backbone, spacer, mesogenic unit and its terminal groups. The results show that 1) a more flexible polymer main-chain is more favorable to the formation of a liquid crystal phase, while 2. a flexible spacer will decrease the 'Jacket Effect' and the liquid crystallinity and 3) a subtle modification of the terminal groups on the mesogenic unit may also have a significant influence on properties of the polymers.

关键词： mesogen-jacketed liquid crystalline polymers polymer backbones spacers mesogenic units liquid crystallinity

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