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25 July 2009, Volume 25 Issue 4

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Content of Chemical Research in Chinese Universities Vol.25 No.4(2009)

2009, 25(4):  0. 

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Articles

Synthesis, Characterization and Phase Transformation of 3D Open-framework Zinc Phosphate [Zn₆(H₂O)P₅O₂₀][C₅N₂H₁₄][C₆H₁₆N₂]_0.5·3H₂O

SONG Yu, DONG Zhao-jun, WANG Yong-wei, FU Jun* and LI Ji-yang*

2009, 25(4):  407-411. 

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With N,N'-dimethylpiperazine(DMPIP) as the structure-directing agent, a zinc phosphate [Zn₆(H₂O)·P₅O₂₀][C₅N₂H₁₄][C₆H₁₆N₂]_0.5·3H₂O(1) with a novel three-dimensional(3D) open-framework architecture was hydrothermally synthesized. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by ICP, NMR, and TG analyses. Compound 1 crystallized in the triclinic space group P1(No.2) with a=0.9984(2) nm, b=1.2354(3) nm, c=1.2384(3) nm, α=88.32(3)°, β=74.57(3)°, γ=75.81(3)° and Z=2. The alternation arrrangement of tetrahedral Zn units[ZnO₄ and ZnO₃(H₂O)] and PO₄ units forms an anionic 3D open framework containing intersecting 16-, 10- and 8-ring channels. Water molecules, diprotonated DMPIP, and diprotonated N-methyl-piperazine(MPIP) decomposed from DMPIP, are located in the channels and interact with the host framework via H-bonds. Compound 1 transforms to another new phase(compound 2) upon calcination at 200―350 °C with the removal of the water coordinated to Zn atoms in the lattice. The phase transformation of compound 2 was further studied.

Carbon Nitride Nanowire Bundle and Tubes: Solid-state Synthesis, Characterization and Photoluminescent Properties

ZHAO Peng, WANG Bai-nian*, CHEN Xiang-ying and QIAN Yi-tai

2009, 25(4):  412-416. 

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Graphite-like carbon nitride nanowire bundles were synthesized from melamine via the solid state thermolysis at relatively low temperature(400 °C). Hexagonal carbon nitride tubes were prepared for the first time by heating the nanowire bundles at 550 °C in argon atmosphere. The forming process of tubes and transformation of the molecular structures from s-triazine rings to tri-s-triazine units were analyzed. The blue and yellow-green emission photoluminescent(PL) properties of the products were investigated in detail, and the reasons for the differences of PL properties between the bundles and tubes were discussed.

New 3D Framework Vanadium(III) Phosphite with One-dimensional 4, 12-Member Ring Channels

ZHANG Hua, WANG Li-ping, SONG Tian-you, WANG Li*, SHI Su-hua* and YANG Lei

2009, 25(4):  417-420. 

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A new vanadium(III) phosphite, V₂(HPO₃)₃(1), was synthesized hydrothermally with V₂O₅, H₃PO₃ as reactants, 1,6-diaminopropane(1,6-HAD) as the structure-directing agent and characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, TGA, ICP-AES and elemental analyses. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallized in the P6(3)/m hexagonal space group with the unit-cell parameters: a=0.80436(10) nm, c=0.73972(2) nm, V=0.41447(13) nm³, Z=4. The construction of 3D framework structure of compound 1 may be viewed as the assembly of V₂O₉ dimers and HPO₃ pseudo-pyramids which lead to form the one-dimensional 4,12-member ring channels along the [001] direction.

Synthesis of Stable Silver Nanoparticles with Antimicrobial Activities in Room-temperature Ionic Liquids

AN Jing, WANG De-song and YUAN Xiao-yan*

2009, 25(4):  421-425. 

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Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate([BMIM]?BF₄) at room temperature. Results of UV-Vis diffuse reflectance spectroscopy show as-prepared Ag nanoparticles exhibit a typical emission peak at 400―430 nm. By varying the reaction temperature and the precursor concentration, the size and the shape of the silver nanoparticles could be easily controlled under mild conditions. Analyses of transmission electron micrographs, X-ray diffraction pattern and X-ray photoelectron spectrum further reveal that the silver nanoparticles were coated incompletely by [BMIM]?BF₄. Microbial experiments indicate that as-prepared silver nanoparticles show a wide spectrum of antimicrobial activities and have better antimicrobial activities to Pseudomonas aeruginosa than silver nitrate with the same concentration of silver.

Hydrothermal Synthesis and Crystal Structure of a New2D Layer Compound [{Ni(en)₂}₂Sb₈V₁₄O₄₂]·5.5H₂O

YU Li, LIU Jiang-ping, WANG Jing-ping and NIU Jing-yang*

2009, 25(4):  426-429. 

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A new compound based on polyoxovanadate [{Ni(en)₂}₂Sb₈V₁₄O₄₂]·5.5H₂O(en=ethylenediamine)(1) was synthesised hydrothermally as black rhombus crystals. Compound 1 crystallized in the monoclinic system with space group P2₁/n, Z=4, a=1.46953(9) nm, b=1.28623(8) nm, c=1.76008(11) nm, β=105.7230(10)°. In the asymmetric unit, cluster {Sb₈V₁₄O₄₂} can be considered as an Sb derivative of the {V₁₈O₄₂} unit. Each {Sb₈V₁₄O₄₂} cluster as a building block interconnected to four other neighboring units by {Ni(en)₂} bridging groups which are linked through the terminal oxygen atoms of the polyoxoanions, forming a two dimensional network.

Structures and Properties of Zn_1-xCu_xO Nanoparticles by Sol-gel Method

LIU Hui-lian, YANG Jing-hai*, ZHANG Yong-jun, WANG Ya-xin and WEI Mao-bin

2009, 25(4):  430-432. 

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Copper-doped ZnO nanoparticles were synthesized by the sol-gel method. The X-ray diffraction(XRD) result shows that Zn_1-xCu_xO(x≤0.04) samples are single phase with ZnO-like wurtzite structure, while the secondary phase Cu is observed in a Zn_0.95Cu_0.05O sample. Magnetic measurements indicate that Zn_1-xCu_xO(x≤0.04) samples are ferromagnetic at room temperature. A strong green peak(520 nm) was observed except for UV band peak in photoluminescent(PL) spectrum of Zn_0.98Cu_0.02O.

Quantitative Determination of Adrenaline Hydrochloride Injection and Noradrenaline Bitartrate Injection by a New HPLC Method via Substitute for Reference Substance

XIE Yuan-chao*, HUANG Hai-wei, ZHANG Qi-ming and JIN Shao-hong

2009, 25(4):  433-438. 

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An HPLC method for quantitative determination of adrenaline hydrochloride injection and noradrenaline bitartrate injection was established and validated with a substitute for the reference substance. Phenylephrine hydrochloride was selected as the substitute for the reference substance of adrenaline and noradrenaline bitartrate. The correction factor of phenylephrine hydrochloride with respect to the reference substance of adrenaline and noradrenaline bitartrate was determined under defined conditions. Adrenaline hydrochloride injection and noradrenaline bitartrate injection were quantified by assaying phenylephrine hydrochloride and a correct factor. The results indicate that the HPLC method with the substitute for reference substance was reliable and feasible for quantitative determination of drugs.

Microwave Assisted-extraction of Flavonols from Acanthopanax Senticosus Harms and High-performance Liquid Chromatography Analysis

LIU Yan-bo*

2009, 25(4):  439-442. 

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Flavonols were extracted from Acanthopanax Senticosus Harms by Soxhlet extraction(SE), atmospheric pressure microwave-assisted extraction(AMAE) and pressurized microwave-assisted extraction(PMAE). The influences of experimental conditions, such as concentration of ethanol in the eluent, microwave irradiation time, etc. on the extraction yield were studied. Four flavonols(hyperin, rutin, quercitrin and quercetin) in the extracts were determined quantitatively by HPLC method. The experimental results demonstrate the advantages of PMAE and AMAE over those of conventional SE, that is the extraction time is dramatically reduced, and the yields of flavonols are effective improved. Although the yield of flavonols is higher and the extraction time is shorter by PMAE than those of AMAE, flavonols are easy to be decomposed over a certain time.

Inhibitive Determination of Heavy Metal Ions by Conductometric Nitrate Reductase Biosensor

WANG Xue-jiang*, XIA Si-qing, ZHAO Jian-fu, ZHAO Hong-ning,......

2009, 25(4):  443-445. 

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A conductometric nitrate biosensor based on methyl viologen/Nafion^®/nitrate reductase(NR) interdigitated electrode for heavy metal determination was proposed. The activity of NR(EC 1.6.6.2) from Asper gillusniger(A. niger) was assayed as a function of metal concentration in the presence of Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺. Parameters influencing the performance of the biosensor were optimized for the application of it in the inhibition determination of heavy metal ions. Detection limits for Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ were about 0.05, 0.5, 0.1 and 1.0 μmol/L, respectively. The results show that NR activity could not be regained after exposure to Cu²⁺, but could be partially recovered after exposure to Zn²⁺, Pb²⁺ and Cd²⁺.

Effect of Sorbents Added on Adsorption Capability of Soil for Nano-TiO₂

PAN Shu-ying, GAO Bao-yu* and YUE Qin-yan

2009, 25(4):  446-450. 

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The adsorption capability of loam soil for nano-TiO₂ affected by the amount and intensity of leached water has been investigated by simulating the natural rainfall process under the leaching condition. The results show that the amount and the intensity of leached water are two important factors affecting the adsorption capability of loam soil for nano-TiO₂. The results indicate that the depth of the loam soil containing a maximal amount of nano-TiO₂ is proportional to the amount of leached water, while it is inversely proportional to the intensity of leached water, at a constant amount of the leached water. It was also found that the adsorption capability of soils for nano-TiO₂ can be improved by adding other materials, such as dissolved organic matter(DOM), bentonite and straw. It was found that DOM is the best sorbent for improving the adsorption capability of loam soil for nano-TiO₂, followed by bentonite, while straw is not suitable for the modification of loam soil. The improvement of adsorption capability of loam soil depends on the amount of these additives. Nano-TiO₂ can be effectively adsorbed on the surface layer of loam soil containing an appropriate amount of additive.

Degradation of Furfural by UV/O₃ Technology

KANG Chun-li*, TANG Xiao-jian, JIAO Xin-qian, GUO Ping, QUAN Fu-min,......

2009, 25(4):  451-454. 

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Furfural in aqueous solution was treated by UV/O₃ method. The results show that the removal rate of furfural is severely enhanced and the synergism phenomenon appears when ultraviolet and ozone are present together. The influences of experimental parameters such as pH, the intensity of light and the negative-positive ions on furfural degradation were investigated. The results indicate that furfural(300 mg/L) is almost completely degraded after 3 h under the optimum conditions. The intermediate in the furfural degradation was characterized by GC-MS and IR spectrum and the degradation mechanism of furfural by UV/O₃ technology was proposed.

Cobalt Sulfate as a Recyclable Catalyst for Chemoselective Synthesis of Diacetates from Aldehydes

WANG Min*, TIAN Gui-fu, SONG Zhi-guo and JIANG Heng

2009, 25(4):  455-457. 

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A mild and efficient method for diacetylation reaction was developed, by which diacetate could be achie- ved through the reaction of aldehyde with acetic anhydride, in the presence of cobalt sulfate, with an admirable yield, at room temperature, without solvent. The catalyst could be recycled six times without a distinct loss of activity.

New Octadecanoyl Diterpenoid Arabinoside from Conyza blinii

CHEN Lei, SU Yan-fang* and TU Guang-zhong

2009, 25(4):  458-460. 

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A new octadecanoyl diterpenoid glycoside, (E)-8α,15-dihydroxy-15-(3S-hydroxy-octadecanoyl)-13- labdene-8-O-α-L-arabinopyranoside(1), was isolated from the aerial parts of Conyza blinii, and the structure was identified on the basis of a detailed spectroscopic analysis, including 2D NMR spectrometry and HRESI-MS.

Michael Addition of Amines to Activated Alkenes Promoted by Zn/NH₄Cl System

KOU Jing-ping, LU Yu-juan, LUO Xu-yang and LI Ji-zhen*

2009, 25(4):  461-464. 

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A Zn/NH₄Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters, nitriles, amides, and ketones to give the corresponding saturated amines under the mild condition in high yield.

Synthesis of Novel 1-Alkyl-2-chloro(alkoxy)-1H-indole 3-Carbaldehyde Oximes and Oxime-ethers(esters) Derivatives

GAO Wen-tao*, GAO De-peng and GUO Hui

2009, 25(4):  465-473. 

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A convenient synthesis of 1-alkyl-2-chloro-1H-indole-3-carbaldehyde oximes(5a―5d) and 1-alkyl-2- phenoxy-1H-indole-3-carbaldehyde oximes(6a―6d) from 2-indolone was completed via the Vilsmeier-Haack reaction, with N-alkylation and oximation as the key steps. An improved one-pot method for the synthesis of 1-alkyl-2-alkoxy-1H-indole-3-carbaldehyde oximes(7a―7h) from 1-alkyl-2-chloro-1H-indole-3-carbaldehydes(3a―3d) was described. The Williamson reactions and esterification reactions were performed and the oxime-ethers and oxime-esters were synthesized, respectively. The new synthesized compounds(3a―11d) were characterized by  ¹H NMR, IR, MS, and elemental analysis.

Synthesis and Antiproliferative Activity of Novel [1,2,4]Triazolo[1,5-a]pyrimidine-7-amine Derivatives

ZHAI Xin, ZHANG Cun-long, HE Lei, LI Qi, WANG Jiu-liang, SHEN Xiao-li,......

2009, 25(4):  474-479. 

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A series of novel N-anilino-2-substituted-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine-7-amine derivatives was prepared and evaluated for their in vitro antiproliferative activity against two cancer cell lines, Bel-7402 and HT-1080. Most of the compounds inhibited the cell proliferation at a low concentration. Seven compounds, VI₅, VI₇, VI₁₀, and VI₁₂―VI₁₅, possessed marked antiproliferative activity superior to that of cisplatin. Of these seven initial hits, compound VI₁₀ was the most active.

Two Eremophilane-type Sesquiterpenoids from theRhizomes of Ligularia veitchiana(Hemsl.) Greenm

2009, 25(4):  480-482. 

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Two eremophilane-type sesquiterpenoids from the rhizomes of Ligularia veitchiana(Hemsl.) Greenm were isolated and determined as 10α,11-endoperoxide-1(2)-en-7α-hydroeremophilane(1) and 1(10)-en-2-oxo-7α-isopropanol-eremophilane(2). Compound 1 was a new compound and compound 2 was a new natural product. The structures of the two compounds were established by means of spectral methods including ¹H NMR, ¹³C NMR, 2D NMR and MS.

Development and Characterization of Monoclonal Antibody Specifically Against TSP50

LIU Yang, BAO Yong-li, YU Chun-lei, WU Yin*, YANG Xiao-guang, XU Hao-peng,......

2009, 25(4):  483-486. 

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Testis-specific protease 50(TSP50) has been identified as a testis-specific protein that is expressed abnormally in most human breast cancer samples, which makes it an attractive molecular marker and a potential target for diagnosis and therapy. In the present study, we prepared a panel of monoclonal antibodies(mAbs) with high specificity and sensitivity against TSP50 by hybridoma method and characterized them by ELISA, Western blot, immunofluroescence and immunohistochemical analyses. The results show that all of the 9 different clones can specifically bind to TSP50. The mAbs against TSP50 we generated could be good tools for both basic and clinical studies.

Effect of Polysaccharides from Fruit Body of Ganoderma tsugae on Bidirectional Regulation of Proinflammatory Cytokine Production in THP-1 Cells

LIU Ai-dong, ZHENG Ke-yan, MIAO Qing-fang, IKEJIMA Takashi, ZHANG Jie,......

2009, 25(4):  487-491. 

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The polysaccharides, FIII-2, FIII-2-a, FIII-2-b and FIII-2-c were purified from the fruit body of Ganoderma tsugae(G. tsugae) to study the effects of the four polysaccharides on the productions of human proinflammatory cytokines, interleukin-1α(IL-1α) and tumor necrosis factor α(TNFα). The results show that the polysaccharides up-regulated the production of IL-1α and TNFα in THP-1 cells under non-stimulatory condition or under stimulation of both lower concentration lipopolysaccharide(LPS) and phorbol myristate acetate(PMA), and they down-regulated the secretion of IL-1α and TNFα under stronger stimulatory conditions. The four polysaccharides promoted the expression of TNFα mRNA. Production of TNFα protein reflects the quantity of TNFα mRNA. These polysaccharides purified from Ganoderma tsugae bodies exhibit bidirectional regulation effects on cytokine production under diffe- rent cell stimulatory conditions.

Characterization of DNA Intercalator Bound to Calf Thymus DNA: Ionic Strength and pH Value Effects

YUAN Chun-li, ZHANG Zhi-chao*, SONG Ting and WU Gui-ye

2009, 25(4):  492-496. 

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By means of circular dichroism(CD) spectrum coupled with UV-Vis and fluorescence spectra, the binding model of DNA intercalator A1{4-(2-diethylamino-ethylamino)-8-oxo-8H-acenaphtho[1,2-b]pyrrole-9-carbonitrile} to calf thymus(CT) DNA was investigated, depending on the values of R(R is defined as the ratio of the concentration of A1 to CT DNA base pairs) and different outer factors. Molecules A1 were intercalated into the CT DNA base pairs in different orientations in the intercalation pocket at a lower R value(R≤0.20), while A1 molecules aggregated on the surface of the helix of the CT DNA as the R value increased. The influence of NaCl on the binding was smaller because the electrostatic interaction only provided approximately 16% of the overall free energy of binding. The protonated diethyl-amine substitution would influence the binding geometry greatly at a low pH value via forming hydrogen bonds with the exposed C=O group on DNA surface.

Letters

Increased Sensitivity of Porcine ΔF508-CFTR Chloride Channel to Specific Small Molecule CFTR Inhibitors

ZHAO Hai-feng, YU Ting, LIU Xin, LIU Rui, ZHENG Lan, SONG Li-na, JIA Li, ......

2009, 25(4):  497-499. 

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Deletion of the codon encoding the phenylalanine residue at position 508(ΔF508) in the cystic fibrosis transmembrane conductance regulator(CFTR) is the most common mutation causing cystic fibrosis(CF). The human ΔF508 mutation results in a CFTR protein with impaired folding, trafficking, and gating in human and rodents. Recent studies suggest that pig ΔF508-CFTR can be efficiently processed to the plasma membrane as maturely glycosylated protein, indicating species difference of the molecular mechanisms of CFTR cellular maturation. In this study, the functional characterization in stably transfected FRT cells cultured at 37 °C demonstrates that pig ΔF508-CFTR is remarkably more sensitive to specific CFTR inhibitors CFTRinh-172 and GlyH101 than wildtype pig CFTR. The wildtype pig CFTR is more sensitive to GlyH101 than to CFTRinh-172. The present study indicates that the gating property of ΔF508-CFTR chloride channel is altered and GlyH101 may be a more suitable small molecule probe for generating CF phenotypes in pig tissues.

Articles

GST Fusion Protein Based Specific Polyclonal Antibody Preparation of Mouse Aquaporin 1

LI Jiang*, YANG Nan-yang, GUAN Xin-gang, ZHANG Shu-zhi, ZHANG Yan,......

2009, 25(4):  500-505. 

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Aquaporins(AQPs) are specific membrane channels for water and other small nonionic molecules. In order to overcome the difficulties to generate the effictive antibody of membrane protein, we selected the cytoplasmic C-terminus of Aquaporin 1(AQP1) as an unique antigen. The long C-terminus of mouse AQP1 was overexpressed in the Glutathione S-tansferase Gene Fusion System. On the basis of the resonable amounts of soluable membrane protein peptides, we prepared the specific antibody. To pursure this object, we constructed pGEX-4T-1/mAQP1(DNA sequence from 700 to 801 bp) recombinant plasmid and transformed it into Escherichia coli BL21 cells. The GST-AQP1 C-terminal hydrophilic peptide fusion protein was induced by IPTG and further purified by Glutathione Sepharose 4B to obtain the right size fusion protein. Then we immunized the New Zealand rabbits to prepare the  antiserum. The purified AQP1 antibody showed high sensitivity by ELISA assay and high specificity by Western blot with AQP1 null mice served as negative control. Finally, we also checked the AQP1 localization in the mouse renal tissues in wild type of mice and AQP1 null mice served as negative control. We demonstrated that AQP1 was highly expressed at the descending limb of Henle tube using our purified AQP1 antibody, which was consistent with previous report. The successful design and preparation of AQP1 antibody through GST technique is an example as ma- king antibodies against a specific membrane protein.

Construction and Cleavage Characterization of SingleTargeted Multi-ribozyme Expression Systems in vitro

TIAN Sheng-Li*, XU Dong-ping and OHNUMA Takao

2009, 25(4):  506-512. 

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In order to clarify cleavage efficiency of a multi-ribozyme expression system on their substrates, plasmids containing 20 cis-acting hammerhead ribozymes for self-cleavage and 10 trans-acting hammerhead ribozymes targeted on MDR1 and MRP1 substrates, the target plasmids pGEM-MDR1 and pGEM-MRP1 were constructed by employing PCR and DNA recombination. The endonuclease’s digestion and DNA sequencing confirmed exactness of the multi-ribozyme expression systems and the target plasmids. The repeated self-cleavage tests revealed that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and trans-acting hammerhead ribozymes 196 Rz and 210 Rz were released. The cleavage efficiencies of liberated ribozymes on their targets were evaluated in vitro and the results indicate that 196 Rz and 210 Rz were able to cleave the MDR1 and MRP1 RNA substrates. The profile of cleavage reaction shows that the cleavage efficiencies were correlated with the numbers of trans-acting hammerhead ribozymes contained in the multi-ribozyme expression systems, as well as the multi-ribozyme system is much better than the single ribozyme. Test of various concentrations of Mg²⁺ reveals that ribozyme cleavage reactions were dependent on Mg²⁺ concentration. The plot of lg(k_obs) vs. lg[Mg²⁺] displays a linear relationship in the concentration range observed(2.5―20 mmol/L).

Effect of Calcium Cation on Thermophilic Acylamino Acid-releasing Enzyme Ape1547 from Aeropyrum pernix K1

ZHOU Jun, XIE Gui-qiu, CAO Shu-gui and GAO Ren-jun*

2009, 25(4):  513-517. 

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The gene of enzyme(Ape1547) was cloned from hyperthermophilic archaeon Aeropyrum pernix K1 and expressed in Escherichia coil. The effect of calcium cation on the properties of Ape1547 was studied. Ape1547 exhibits both peptidase activity and esterase activity. The fluorescence spectrum shows that calcium cation quenches the fluorescence of the enzyme through static quenching mechanism, indicating that calcium cation was bound to the enzyme. Based on the study of calcium cation on CD ellipticity of Ape1547 by circular dichroism, we concluded that the change of enzyme structure induced by calcium cation may be responsible for the change of enzyme activity. Calcium cation has dual effects on Ape1547: it could activate the enzyme activity when its concentration was 0.1 mol/L, and the enzyme had the highest activity; however, when its concentration was higher than 0.2 mol/L, the enzyme activity was inhibited. The results indicate that the activity center of peptidase activity might involve more amino acid residues than that of esterase activity.

Highly Luminescent N-Benzylcarbazole Compound Immobilized in Amino-functionalized Mesoporous SBA-15

WANG Hong-su, GUAN Jing-qi, SONG Ke, XU Chen and KAN Qiu-bin*

2009, 25(4):  518-521. 

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An inorganic-organic photoluminescence solid material was obtained by immobilizing N-benzylcarbazole compound to an amino-functionalized mesoporous SBA-15(designated as N-benzylcarbazole-amino-SBA-15). XRD, SEM, and N₂ adsorption-desorption measurements indicate that the mesostructure of parent material SBA-15 was preserved after introducing amino and N-benzylcarbazole groups. The absorbance and emission studies reveal that the fluorescent N-benzylcarbazole-amino-SBA-15 exhibited red-shift character in comparison to pure N-benzylcarbazole.

Liquid Membrane Oscillation of Water/Oil/Water SystemContaining TTAB and Recognition to Amino Acids

ZHOU Li*, TANG Jiao-ning, LIU Bo and WU Yi-guang

2009, 25(4):  522-525. 

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The liquid membrane oscillation of a novel water(aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution)/oil(picric acid in chloroform solution)/water(aqueous glucose solution) system was investigated by means of a homemade device. The results show that the water(aqueous 7 mmol/L TTAB and 0.5 mol/L n-propanol solution)/oil(0.5 mmol/L icric acid in chloroform solution)/water(0.1 mol/L glucose solution) system performed sustained and stable oscillation at 30 °C. The oscillation curve under optimized conditions is considered to be referent. Several oscillation curves were accumulated with the addition of different amino acids. The results showed that the novel system can recognize the added amino acids such as L-tryptophan, L-tyrosine, and D,L-tyrosine. And there is corresponding relationship between the change of curve shape and the quantity of amino acid added.

Low-temperature Heat Capacities and Thermodynamic Properties of Solid State Coordination Compound Zn(nicotinate)₂·H₂O(s)

CHEN Jing-tao, DI You-ying*, DAN Wen-yan, HONG Yuan-ping, YANG Wei-wei,......

2009, 25(4):  526-531. 

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A novel compound—monohydrated zinc nicotinate was prepared via room temperature solid phase synthesis and ball grinding. FTIR, chemical and elemental analyses and X-ray powder diffraction technique were applied to characterizing the structure and composition of the complex. Low-temperature heat capacities of the solid coordination compound were measured by a precision automated adiabatic calorimeter over a temperature range from 77 to 400 K. A solid-solid phase transition process occurred in a temperature range of 321―342 K inferred according to the heat capacity curve, and the peak temperature, molar enthalpy and entropy of the phase transition of monohydrated zinc nicotinate were determined to be T_trs=(340.584±0.829) K, ?_trsH_m=(12.682±0.041) kJ/mol and ?_trsS_m= (37.235±0.101) J/(K?mol). The experimental values of the molar heat capacities in the temperature regions of 77―321 K and 342―400 K were, respectively, fitted to two polynomial equations. In addition, the polynomial fitted values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K.

Apparent Kinetics for Electrosynthesis Process of Chromic Acid

LI Cheng-wei, WANG Fu-an*, QI Tao, WANG Rui-lin, TANG Xiao-hong, ......

2009, 25(4):  532-536. 

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A new green technique for producing chromic acid via an electrosynthesis method was studied. The kinetic experiments were carried out on the direct electrosynthesis reaction of chromic acid from sodium dichromate in a self-made electrosynthesis reactor with a multiple-unit metal oxides combination anode, a stainless steel cathode, and a reinforcing combination Nafion^®324 cation exchange membrane. The apparent kinetic data were experimentally measured at different reaction time under different reaction conditions by relating many essential cell processes and their interaction, as well as their synergistic effect to the whole electrochemical synthesis process. The results show that the electrosynthesis reaction process follows a quasi-first-order reaction kinetic characteristic. The apparent kinetic model of the electrosynthesis reaction was established, and kinetic parameters were calculated.

Charge Transport Processes of Immobilized Heteropolyanions atSelf-assembled Monolayer Modified Gold Electrode byElectrochemical Quartz Crystal Microbalance Measurement

BU Xin-yuan, JIAO Lian-sheng, HAN Dong-xue* and YANG Gui-fu*

2009, 25(4):  537-542. 

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The in situ electrochemical quartz crystal microbalance(EQCM) technique was used to investigate the ion transport of immobilized heteropolyanions at a self-assembled monolayer(SAM) modified gold electrode during electrochemical redox process. A mixed transfer method was presented to analyse the abnormal change of resonant frequency based on the simultaneous insertion/extraction of different ions. The results indicate that the migration of HSO₄^– anions was indispensable in the redox process of the heteropolyanions in a 1 mol/L H₂SO₄ solution and played a key role in the abnormal change of the resonant frequency. Such a change was attributed to different packing densities derived by means of differently immobilized methods.

TiO₂/NaY Composite as Photocatalyst for Degradation of Omethoate

ZHAO Di-shun*, WANG Jia-lei, ZHAO Xue-heng and ZHANG Juan

2009, 25(4):  543-549. 

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Photocatalytic activities of TiO₂ and NaY zeolites-supported TiO₂ were investigated with omethoate as a model pollutant. The physical and chemical states of NaY zeolite-supported TiO₂ were evaluated via XRD, FTIR, BET and SEM. Photodegradation of omethoate was studied with H₂O₂ as oxidant and TiO₂ supported on NaY zeolite as photocatalyst. Parameters involved in the photo-catalysis of omethoate, i.e., the calcination temperature of the photocatalyst, initial omethoate concentration, the amount of TiO₂ loaded on NaY zeolite, photocatalyst dosage and H₂O₂ concentration were investigated in detail. The results show that TiO₂/NaY zeolite prepared by means of sol-gel method exhibited a good photocatalytic activity for the degradation of omethoate. Optimum conditions included the calcination temperature of photocatalyst 550 °C, initial omethoate concentration 500 mg/L, the amount of TiO₂ loaded on NaY zeolite 35%(mass fraction), the amount of photocatalyst 5 g/L, H₂O₂ concentration 30 mL/L and an irradiation time of 180 min. The removal of omethoate was up to 93%. Kinetics parameters of the photocatalytic degradation of omethoate were measured and calculated. The result shows the kinetics of photocatalytic degradation of omethoate is first-order.

Electron Communication Between Electrode and Dye-Linked L-Proline Dehydrogenase in Organized Layer-by-Layer Multilayer Film

ZHENG Hai-tao*, DONG Li-ping, LIU Hai-hui, JIA Hai-lian and SUYE Shin-ichiro

2009, 25(4):  550-555. 

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Multilayer film was fabricated on an electrode surface by alternate layer-by-layer(LBL) adsorption of polycationic redox polymer(PEI-Fc) and dye-linked L-proline dehydrogenase(L-proDH). The electrochemistry of the PEI-Fc/L-proDH multilayer modified electrode was investigated by cyclic voltammetry, and the enzyme catalysis mediated by the redox polymer was studied in a solution containing L-proline. It was observed that electron communication between L-proDH and the electrode was achieved with the help of PEI-Fc. A mathematical expression for the current response was evaluated based on the Michaelis-Menten kinetics mode, and the calculated currents fitted well with the experimental data. The kinetic analysis indicates that only a small fraction of the immobilized enzyme was efficiently electrically wired by the redox polymer. 

Interaction Between 1,2,3-Trichloropropane and Haloalkane Dehalogenase LinB

ZHAO Yong-shan, ZHENG Qing-chuan*, ZHANG Hong-xing, CHU Hui-ying, ......

2009, 25(4):  556-559. 

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The haloalkane dehalogenase LinB from Sphingomonas paucimobills UT26 was found to transform the 1,2,3-trichloropropane(TCP) into inorganic halide ions and 2,3-dichloro-1-propanol although the catalytic activity is very low(K_cat=0.005 s^–1). In this study, molecular dynamics simulation and docking studies were performed to investigate the binding of TCP to LinB. The docking results indicate that LinB does not restrict TCP to be bound productively in the active site and the water-mediated inhibition occurs in the process of TCP interacting with LinB. The residues Ile134, Leu150, Phe154, Pro208, and Ile211 located on the cap domain are potential targets for mutagenesis researches.

Solvent Effect on Conformation of a Cycloheptapeptide, Stylopeptide 1, Evaluated by Molecular Dynamics in Methonal and Aqueous Environments

LIU Xiao-qing, LI Xiao-hui, TENG Hu and XIU Zhi-long*

2009, 25(4):  560-563. 

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Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer cell. Based on the different amounts of methanol and water during synthesis, isolation and purification of the cyclic peptides, molecular dynamics(MD) was employed to simulate the conformation of stylopeptide 1 in methanol and aqueous environments. The comparative results show that the backbone ring was more rigid in methanol than in water. In methanol, two β-turns and three hydrogen bonds were well conserved throughout the simulation, whereas no hydrogen bonds or turns were preserved in water. The activity difference of stylopeptide 1 seemed to be attributed to the solvent effect on its conformation.

Synthesis, Characterization and Standard Molar Formation Enthalpy of [Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]?2H₂O

LI Xu, YANG De-jun, LI Qiang-guo*, LI Ai-tao, YE Li-juan and JIANG Jian-hong

2009, 25(4):  564-568. 

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[Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]·2H₂O was synthesized from the reaction of samarium chloride hexahydrate with salicylic acid and thioproline, and characterized by IR, elemental analysis and thermogravimatric analysis. The standard molar enthalpies of the solutions of SmCl₃·6H₂O(s), 2[C₇H₆O₃(s)], [C₄H₇NO₂S(s)] and [Sm(C₇H₅O₃)₂·
(C₄H₆NO₂S)·2H₂O(s)] in a mixed solvent of absolute ethyl alcohol, dimethyl formamide(DMF) and 3 mol/L HCl were, respectively, determined by calorimetry to be Δ_sH_m^Θ[SmCl₃·6H₂O(s), 298.15 K]=(–46.68±0.15) kJ/mol, Δ_sH_m^Θ[2C₇H₆O₃(s), 298.15 K]=(25.19±0.02) kJ/mol, Δ_sH_m^Θ[C₄H₇NO₂S(s), 298.15 K]=(16.20±0.17) kJ/mol and  Δ_sH_m^Θ{[Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]·2H₂O(s), 298.15 K}=(–81.24±0.67) kJ/mol. The enthalpy change of the reaction SmCl₃·6H₂O(s)+2C₇H₆O₃(s)+C₄H₇NO₂S(s)=[Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]·2H₂O(s)+3HCl(g)+4H₂O(l) was determined to be Δ_rH_m^Θ=(123.45±0.71) kJ/mol. From the data in the literature, the standard molar formation enthalpy of [Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]·2H₂O(s) was estimated to be Δ_fH_m^Θ{[Sm(C₇H₅O₃)₂(C₄H₆NO₂S)]·2H₂O(s), 298.15 K}= (–2912.03±3.1) kJ/mol through Hess’ law.

Novel Method for Preparation of Polypropylene Blends with High Melt Strength by Reactive Compounding

LIU Yu-guang, HUANG Yu-dong*, ZHANG Cheng-wu, HOU Jing and ZHANG Xue-quan

2009, 25(4):  569-572. 

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Ultrafine full-vulcanized polybutadiene rubber(UFBR) with particle sizes of ca. 50―100 nm were used for modifying mechanical and processing performances of polypropylene(PP) with PP-g-maleic anhydride(PP-g-MA) as a compatibilizer for enhancing the interfacial adhesion between the two components. The morphology, dynamical rheology response and mechanical properties of the blends were characterized by means of SEM, rheometer and tensile test, respectively. The results show that the ternary PP/UFBR blends compatibilized with PP-g-MA possess rheological behaviors like highly branched PP, while no obvious strain hardening is observed in its control binary PP/ UFBR blends, a low level of PP-g-MA in PP/UFBR blends can even endow the material with rheological characteristics of high melt strength materials like highly branched PP. The enhancement interfacial interaction between the UFBR particles and PP matrix accounting for the rheological behavior of compatibilized blends and effectiveness of PP-g-MA were proposed and proved.

Dynamic Mechanical Behavior and Prediction for PP/POE Blends

YING Ji-ru, XIE Xiao-lin*, ZHOU Xing-ping, ZHOU Hua-min and LI De-qun

2009, 25(4):  573-578. 

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Polypropylene(PP)/ethylene-octene copolymer(POE) blends were prepared with a twin-screw extruder. Their dynamic mechanical behavior were systematically investigated. The results show that PP/POE blends are heterogeneities with a partial compatible two-phase structure, the glass transition temperature of PP phases in the blends tends to shift towards high temperature with increasing the POE content, and the glass transition temperature of POE phases shifts towards the low temperature with increasing the PP content. The Kerner’s dispersed phase model and co-continuous phase model can reasonably predict the visco-elasticity of PP/POE blends with different compositions. Additionally, the morphological structure of the blends can be estimated via comparing the predicted DMA behavior with the experimental data.

Odd-even Effect on Liquid Crystalline Behavior for C₃-Cyclotriveratrylene(CTV) Derivatives Containing Alkoxies with Different Lengths as Peripheral Groups

CHEN Dan-mei, DONG Yan-ming*, SHEN Bing-xing, YANG Xue-hui, LI Yan-jie, ......

2009, 25(4):  579-584. 

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A series of bowlic cyclotriveratrylenes(CTV) with peripheral groups with different lengths were synthesized. These compounds were investigated by diferential scanning calorimetry and hot stage coupled polarizing microscopy. Several CTV derivatives show thermotropic liquid crystalline properties. The experimental results of their thermotropic liquid crystalline behavior indicate that the clear points, the entropy changes of melting points, the crystallization temperatures, and their entropy changes all exhibited an evident odd-even effect except the melting points, which decreased monotonously with the increase of the length of the alkoxy groups. The parameter values of CTVs with even number carbon atoms were larger than those of CTVs with odd number. When the length of alkoxyl chains was even longer, a monotonous decrease occured. Nevertheless, in the case of the entropy changes of both melting points and crystallization temperatures, the effect was valid for all the six species, and therefore, the whole curves presented as a zig-zag form.

Synthesis of Poly[2,2′-(m-phenylene)-5,5′-bibenzimidazole] andPoly(2,5-benzimidazole) by Microwave Irradiation

HE Rong-huan*, SUN Bao-ying, YANG Jing-shuai and CHE Quan-tong

2009, 25(4):  585-589. 

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A rapid way assisted by microwave irradiation was proposed to synthesize poly[2,2′-(m-phenylene)-  5,5′-bibenzimidazole](PBI) and poly(2,5-benzimidazole)(ab-PBI). Synthesis of PBI in polyphosphoric acid is conducted for 20 h or even more. Under microwave irradiation, the polycondensations could be completed in polyphosphoric acid within 3 h from 3,3′-diaminobenzidine tetrahydrochloride(DAB·4HCl·2H₂O) and isophthalic acid for PBI, and from 3,4-diaminobenzoic acids(DABA) for ab-PBI, respectively. The conditions for the polymerization including the power of microwave irradiation, temperature, heating time, and concentrations of the reactants in polyphosphoric acid were optimized. The inherent viscosity of the polymers in concentrated sulfuric acid at 30 °C was 0.9766 dL/g for PBI, and 0.6480 dL/g for ab-PBI, respectively. Characterization of the polymer products was made by nuclear magnetic resonance(¹H NMR), Fourier transform infrared spectra(FTIR) and thermogravimetric analysis(TGA).

Bright White Organic Light-emitting Device Based on 1,2,3,4,5,6-Hexakis(9,9-diethyl-9H-fluoren-2-yl)benzene

MA Tao, YU Jun-sheng*, LOU Shuang-ling, TANG Xiao-qing, JIANG Ya-dong, ......

2009, 25(4):  590-594. 

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Organic light-emitting devices(OLEDs) with the structure of indium-tin-oxide(ITO)/N,N′-bis-(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine(NPB)/2,9-dimenthyl-4,7-diphenyl-1,10-phenanthroline(BCP)/tris(8-hydroxyquinoline)aluminum(Alq₃)/Mg:Ag or that of ITO/NPB/1,2,3,4,5,6-hexakis(9,9-diethyl-9H-fluoren-2-yl)benzene(HKEthFLYPh)/Alq₃/Mg:Ag were studied. White light emission was achieved with the two devices when the thicknesses of BCP and HKEthFLYPh were 1.5 nm(device B) and 5 nm (device II), respectively. The obvious difference was that the EL spectrum of device II was not sensitive to the thickness of HKEthFLYPh compared to that of BCP layer. Moreover, the maximum luminance of device II was about 1000 cd/m² higher than that of device B at a forward bias of 15 V, and it exhibited a maximum power efficiency of 1.0 lm/W at 5.5 V, which is nearly twice that of device B. The performance of device II using a novel star-shaped hexafluorenylbenzene organic material was improved compared with that of BCP.