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25 May 2008, Volume 24 Issue 3

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Content of Chemical Research in Chinese Universities Vol.24 No.3(2008)

2008, 24(3):  0-0.  doi:

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Articles

Preparation, Structure and Properties of 3D Supramolecular Architecture, on the Basis of Hydrogen Bonds and π-π Stacking Between 2D Layers, with Windmill Building Blocks

YU Li-qiong, HUANG Ru-dan, CHI Ying-nan , HU Chang-wen

2008, 24(3):  251-254.  doi:

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A novel three-dimensional(3D) supramolecular architecture, {[Nd(OH-BDC)(OH-HBDC)(H₂O)₂]·2H₂O}_n(1)(OH-H₂BDC=5-hydroxyisophthalic acid), which was formed through hydrogen bonds and π-π stacking between two-dimensional(2D) layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H₂BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain(•••M―O―C―O―M•••) along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer(LMCT). Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.

Synthesis, Crystal Structure and Electrochemistry of Two Complexes (YL_n)³⁺[PW₁₂O₄₀]³⁻(L=Me₂SO, Me₂NCHO)

HAN Qiu-xia , WANG Chun-zhang , MA Jian-ru , NIU Jing-yang , WANG Jing-ping

2008, 24(3):  255-259.  doi:

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The reaction of α-H₃[PW₁₂O₄₀] with Y(NO₃)₃ in the presence of DMF or DMSO leads to two complexes with the formulae {Y(DMSO)₇}·PW₁₂O₄₀(1) and {[Y(DMF)₇]₂PW₁₂O₄₀}·PW₁₂O₄₀(2). The crystal structures indicate that complex 1 consists of discrete [YL_n]³⁺ cations and α-Keggin heteropolyanions [PW₁₂O₄₀]³⁻, whereas, in complex 2, donor-acceptor interaction results in a cation-anion-cation triplet. In addition, the electrochemical behavior of the two complexes indicates the usual successive reduction processes of the W atoms in the anions.

A Facile Solvothermal Synthesis of Monodisperse Ni Nanoparticles

YU Peng-fei, CUI Bin, ZHANG Yan , SHI Qi-zhen

2008, 24(3):  260-262.  doi:

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A simple solvothermal approach was developed to synthesize uniform spherical monodisperse Ni nanoparticles, which can easily disperse in nonpolar solvents to form homogenous colloidal solution. The as-prepared sample was characterized by XRD, TEM, and FTIR. The results indicate that Ni nanoparticles have the structure of face-centered cube and a narrow distribution with a diameter of (3.5±0.5) nm. The FTIR spectrum reveals that the nanoparticles are coated with oleic acid. In the synthetic process, N₂H₄·H₂O was used as a reducing agent and oleic acid as a surfactant. The probable formation mechanism of the spherical nanoparticles was also discussed.

A New Maleamide Bridged Carbazole Chromogenic-sensor Based on Proton Transfer Signaling Mode

WANG Yue-hong , LIN Hai , SHAO Jie , LIN Hua-kuan

2008, 24(3):  263-265.  doi:

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A Maleamide bridged carbazole receptor was designed and synthesized, the interactions between the receptor and anions, such as Ac^-, H₂PO₄^-, OH^-, F^-, Cl^-, Br^- and I^- in DMSO were investigated by UV-Vis spectroscopy and ¹H NMR titration. The results of UV-Vis spectral studies indicate that interactions existed between receptor and anions, which induced remarkable color changes. The ¹H NMR titration indicated amide moiety of the receptor was deprontonated first when a small quantity of anions such as Ac^-, H₂PO₄^-, F^- were added; however, the carbazole N―H was gradually deprontonated upon the addition of anions.

Synthesis and Optical Properties of Ce-doped ZnO

YANG Jing-hai, , GAO Ming , ZHANG Yong-jun , YANG Li-li , LANG Ji-hui, , WANG Dan-dan , WANG Ya-xin , LIU Hui-lian , FAN Hou-gang , WEI Mao-bin , LIU Fu-zhu

2008, 24(3):  266-269.  doi:

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ZnO nanorods were synthesized using the sol-gel method, and the effects of annealing temperature and Ce doping on the morphologies and optical properties of ZnO nanostructures were investigated in detail. The XRD measurements showed that the as-synthesized ZnO nanostructures had a hexagonal wurtzite structure. SEM images showed that uniform nanorods formed at 900 °C. Photoluminescence measurements showed an ultraviolet emission peak and a relatively broad visible light emission peak for the samples sintered at different temperatures. The UV emission peak bathochromically shifted when the annealing temperature rose from 850 to 1000 °C. Ce doping decreased the synthesized temperature of the ZnO nanorods to 500 °C, and the UV peaks hypsochromically shifted.

Studies on the Components of Crude and Processed Fructus Corni by ESI-MSⁿ


ZHOU Li-li , WU Guo-guang , LIU Zhi-qiang , LIU Shu-ying

2008, 24(3):  270-274.  doi:

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The components of crude and processed Fructus Corni were investigated by means of electrospray ionization-tandem mass spectrometry(ESI-MSⁿ) technique in the negative ion mode. Compared with those of crude Fructus Corni, the chemical components of the processed Fructus Corni were changed both in quality and in quantity. From the ESI-MS spectra of the crude and processed Fructus Corni, six peaks were selected to establish the characte- ristic ESI-MS peaks. Several factors in the processing procedure were examined. The experimental results demonstrate that the chemical reactions that occurred in the processing procedure can be used for the elucidation of the processed mechanism of Fructus Corni, which is regularly affected by the processing conditions. The present article provides both the chemistry evidence for the understanding of the processing procedure of Fructus Corni and the specific methodology for the research of the processing procedure and quality identification of traditional Chinese medicine.

Rapid Extraction and Analysis of Essential Oil from Cinnamomum Cassia Presl.

WANG Lu , WANG Zi-ming , LI Tie-chun , ZHOU Xin , DING Lan , ZHANG Han-qi

2008, 24(3):  275-280.  doi:

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An improved solvent-free microwave extraction(ISFME) was used for the extraction of essential oil from dried Cinnamomum cassia Presl. Two kinds of solid microwave absorption media[carbonyl iron powder(CIP) and graphite powder(GP)] were used. When ISFME was applied, the heating rate was enhanced and the extraction time was obviously shorter than that consumed in conventional solvent-free microwave extraction(CSFME). Twenty-eight kinds of compounds in the essential oil were identified, and the total content fractions of the compounds obtained by CIP-ISFME, GP-ISFME, CSFME, and hydrodistillation(HD) were 96.65%, 96.06%, 97.22%, and 96.29%, respectively. The compounds in the essential oil obtained from Cinnamomum cassia Presl. by ISFME, CSFME, and HD were compared and the quantity of the essential oil was almost the same. The ISFME has been proved to be a feasible way to extract essential oil from dried samples, and there are several obvious advantages in ISFME over those of HD and CSFME, for example, shorter extraction time(30 min) and lower energy consumption.

Evaluation and QSAR Study of Joint Toxicity of Substituted Phenols and Cadmium to Photobacterium phosphoreum


SU Li-min, YUAN Xing, MU Chun-fang, YAN Ji-chang , ZHAO Yuan-hui

2008, 24(3):  281-284.  doi:

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The single toxicity of cadmium(Cd) or 9 substituted phenols to Phtobacterium phosphoreum was determined, respectively. The results indicate that the single toxicity was related to group variety, group sum and substitutive positions. On the basis of single toxicity, the joint toxicity of Cd and 9 substituted phenols was measured. The result indicates that the joint toxicity was basically a simple addition of the single toxicity of them or close to simple addition of the single toxicity of them. QSAR equations were built from the joint toxicity and molecular structural descriptors of substituted phenols under the different Cd concentrations. It was shown that the joint toxicity under different Cd concentrations was related to the identical descriptors, the logarithm of n-octanol/water partition coefficient(lgP) and the heat of formation(ΔH_f), with R²=0.855, 0.878 and 0.780, respectively. Good agreement between the predicted and observed values was found with R²=0.837.

Degradation of Phenol by Hydroxyl Radicals on Different Coating Lead Dioxide Electrodes


LIU Miao , TANG Yi-nan , WANG Li , HU Yan-dong , JIAO Xin-qian , HUANG Wen-peng

2008, 24(3):  285-290.  doi:

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Lead dioxide electrodes on Ti substrates were prepared by thermal-deposition or electro-deposition. The amount of hydroxyl radicals generated at the electrodes prepared by the above-mentioned two methods was compared with that at the electrodes mingled with Bi or La prepared by electro-deposition. The experimental results indicate that the highest concentration of hydroxyl radicals generated by thermal-deposition, electro-deposition mingled with nothing, electro-deposition mingled with Bi or La was 0.781, 1.048, 1.838 or 2.044 μmol/L, respectively. When phenol was electrolyzed on the four electrodes at a current density of 30 mA/cm², the removal efficiency of phenol after electrolysis for 1.5 h was 87.30%, 93.55%, 97.95% or 98.70%, TOC removal efficiency after electrolysis for 5 h was 86.76%, 94.26%, 98.53% or 99.60%, respectively. Through the degradation experiments of phenol, the amount of hydroxyl radicals was responsible for the removal efficiency of phenol. The electro-catalytic characteristics were investigated by SEM, the generation amount of hydroxyl radicals, the degradation degree of phenol and the stability and conductivity of the electrodes were also investigated. The experimental results indicate that the four electrodes all show good electro-catalytic characteristics; the electro-catalytic characteristics of the electrode mingled with La were superior to those of the other three ones, and the electrochemical degradation of phenol followed one-step reaction dynamics.

Synthesis, Crystal Structure and Biological Activity of Novel Dichloroacetyl Oxazolidine Herbicide Safeners


FU Ying , FU Hong-gang , YE Fei , WEN Xiao-tian , JIANG Ling-xue

2008, 24(3):  291-294.  doi:

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A series of novel N-dichloroacetyl oxazolidine herbicide safeners was synthesized and characterized by IR, ¹H NMR, ¹³C NMR, elemental analysis and X-ray diffraction. The preliminary biological test shows that the compounds could protect maize against injury caused by chlorsulfuron to a certain extent.

Synthesis, Crystal Structure and Biological Activity of 2-Chloro-N-{2-fluoro-5-[N-(phenylsulfonyl) phenyl- sulfonamido]phenyl}benzamide

LI Wen-ming, WANG Jian-guo, LI Zheng-ming , SONG Hai-bin

2008, 24(3):  295-298.  doi:

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2-Chloro-N-{2-fluoro-5-[N-(phenylsulfonyl)phenylsulfonamido]phenyl}benzamide was synthesized and its crystal structure was also determined by X-ray single-crystal diffraction. The title compound(C₂₅H₁₈ClFN₂O₅S₂) belongs to monoclinic, space group P2₁/n with a=0.7377(3) nm, b=1.2036(5) nm, c=2.6846(11) nm, β=90.895(9)°, V=2.3833(16) nm³, M_r=544.98, Z=4, D_c=1.519 g/cm³, μ=0.385 mm^–1, F(000)=1120, R₁=0.0632, and wR₂=0.1438. Its crystal structure belongs to a novel class that has not been reported yet, and its preliminary herbicidal activity was also tested. Its inhibition rate to seedling growth of barnyard grass reaches 15.1% at 100 μg/mL.

Structure and Biological Activities of Novel Triazole Compounds Containing 1,3,4-Oxadiazole Ring


XU Liang-zhong, BI Wen-zhao, SHANG Yu-qing, ZHAI Zhi-wei , YI Xu

2008, 24(3):  299-302.  doi:

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Eighteen novel triazole compounds containing 1,3,4-oxadiazole groups were synthesized from 2-(1H- 1,2,4-triazol-1-yl)acetohydrazide and carbon disulfide by several step reactions. The target compounds were characterized by elemental analysis, ¹H NMR, ¹³C NMR, IR, MS, and X-ray crystallography. The results of preliminary biological tests show that all the compounds exhibit certain fungicidal activities.

New Macrocyclic Diamide from Rauvolfia Yunnanensis Tsiang

GENG Chang-an , LIU Xi-kui

2008, 24(3):  303-305.  doi:

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A new macrocyclic diamide, 22-membered macrocyclic diamide, named cyclodicaprylamide(2), and five known compounds, bis(2-ethylhexyl) phthalate(1), ethyl 3,4,5-trimethoxybenzoate(3), ethyl 3,4,5-trimethoxycinnamate (4), (+)-syringaresinol(5), loliolide(6), were isolated from the roots of Rauvolfia yunnanensis Tsiang. Their structures were elucidated based on NMR, 2D NMR, and MS spectrum, respectively. They were obtained from it for the first time.

Schiff-base Amino Alcohol-zinc Complex for Enantioselective Addition of Phenylacetylene to Aromatic Ketones

CHEN Chao, HONG Liang, WANG Quan, ZHANG Bang-zhi , WANG Rui

2008, 24(3):  306-311.  doi:

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A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%(molar fraction), an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.

Mutation Analysis of AVPR2 and AQP2 Gene in Chinese Patients with Congenital Nephrogenic Diabetes Insipidus

WANG Ying , LI Hong-jun , YU Zhen-xiang , BAO Yong-li , WU Yin , YU Chun-lei , MENG Xiang-ying , LI Yu-xin

2008, 24(3):  312-315.  doi:

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To detect mutations of the aquaporin 2 gene(AQP2) and the arginine vasopressin V2 receptor gene(AVPR2) of Chinese congenital nephrogenic diabetes insipidus, and to establish the foundation for further studying the emergence mechanism of the disease and clinical diagnosis, all the exons and part of introns of AQP2 and AVPR2 genes were amplified with intronic primers, using genomic DNA extracted from three patients with congenital nephrogenic diabetes insipidus and two mothers as template, PCR product was ligated into a T-vector and then sequenced. The result was compared with the database sequence to identify the mutable sites via a BLAST search, the incidence of every mutation was analyzed, and the putative transcription factor binding sites that maybe disturbed were analyzed by MAPPER. Mutation g.1394A>G in exon 3 of AVPR2 was detected in all the subjects, g.861C>T(S167L) in exon 2 of AVPR2 and IVS1+3G>A in intron of AQP2 were detected, respectively, in two patients, and c.836A>C in 3′ untranslated region of AQP2 was detected in two patients and one mother. Four mutations were identified. g.1394A>G of AVPR2 and c.836A>C of AQP2 have high incidence in patients with nephrogenic diabetes insipidus. Detection on the two sites may become auxiliary diagnosis index of congenital nephrogenic diabetes insipidus.

Expression and Characterization of HIV-1 Envelope Glycoprotein in Pichia Pastoris

ZHAO Li-hui , YU Xiang-hui , JIANG Chun-lai , WU Yong-ge , SHEN Jia-cong , KONG Wei

2008, 24(3):  316-321.  doi:

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To obtain a sufficient amount of glycoprotein for further studying the structure and function of HIV-1 envelope glycoprotein, amplified and modified HIV-1 envelope glycoprotein gene which recombined subtypes(850 amino acids) from Guangxi in China was inserted into Pichia pastoris expression vector pPICZαB; then the recombinant plasmid was transported into the yeast cells to induce the expression of Env protein with methanol. The results of SDS-PAGE and Western blot indicate that the envelope glycoprotein could be expressed in Pichia pastoris with productions of a 120000 glycoprotein and a 41000 glycoprotein, which showed satisfactory immunogenicity by indirect ELISA.

Comparison Between the Effects of 2-Selenium Bridged β-Cyclodextrin and Ebselen on Treating SHRsp Stroke

JIA Zhi-dan, LIN Feng, LIU Lei, MU Ying, YAN Gang-lin , LUO Gui-min

2008, 24(3):  322-329.  doi:

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A glutathione peroxidase(GPX) mimic, 2-selenium bridged β-cyclodextrin(2-SeCD), was synthesized. In order to examine its role and mechanism in treating stroke we chose stroke-prone spontaneously hypertensive rats(SHRsp) as animal model. 56 SHRsps of 8-week olds were randomly divided into several groups: test groups (low, moderate, high dose of 2-SeCD) and control groups(positive and negative). After onset of the stroke, the rats in test groups were orally administrated with different amounts of 2-SeCD, the positive control group with ebselen, and the negative control group with drinking water. The treatment lasted two weeks, followed by observation of the rats for 10 days, meanwhile blood pressure, biochemical parameters of plasma, and the contents of nitric oxide(NO) and malondialdehyde(MDA) in plasma and brain were determined. The results show that there were significant differences in contents of NO and MDA in plasma and brain between the test groups(high, moderate dose of 2-SeCD) and negative control group. The NO contents of the test groups were obviously higher than that of the negative control group (P<0.01). The MDA contents of the test groups(high, moderate dose of 2-SeCD) were obviously lower than that of the negative control group(P<0.01). The mechanism of 2-SeCD in treating stroke was discussed, which maybe related to the increase of NO and the decrease of MDA in plasma and brain tissue, but the exact mechanism should be further studied. Moreover, the tendencies of changes in systolic blood pressure, contents of NO and MDA, and other physiological parameters for the test groups were shown to be much better than the corresponding parameters for the positive group(the group with ebselen)(P<0.05), indicating that the treatment effect of 2-SeCD is better than that of ebselen.

In vivo Anti-tumor Effect of siRNA Against STAT3 on Transplanted Lewis Lung Cancer in Mice


WANG Chun-guang , WANG Rong-you , SUN Mei , LI Jin-dong , GAO Nan , ZHANG Xing-yi , SHI Dong-lei , JIN Cheng-yan

2008, 24(3):  330-337.  doi:

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This study aims at determining the therapeutic effect of knockdown of signal transducers and activators of transcription3(STAT3) gene expression by short interference RNA(siRNA) on transplanted Lewis lung cancer in mice in vivo. pSilencer 2.1-U6 STAT3 siRNA against STAT3(STAT3 siRNA) was synthesized. Lewis lung cancer cells were inoculated subcutaneously into C57BL/6 mice. Seven days after inoculation, the tumor-bearing mice were randomly divided into 3 groups and received intratumoral injection of (1) vehicle(PBS solution), (2) vector(negative control), and (3) STAT3 siRNA. Tumor volume and weight were calculated. Tumors and the lungs were excised for 21 days after inoculation. Expressions of STAT3, vascular endothelial growth factor(VEGF), and matrix metalloproteinase-2(MMP2) were analyzed by RT-PCR, Western blot, and immunohistochemical staining. HE staining and TUNEL assay were used to confirm the apoptosis of tumors. The synthetic STAT3 siRNA effectively suppressed tumor growth, prevented tumor from pulmonary metastasis, and induced tumor apoptosis in vivo compared with vehicle and vectore in controls. It significantly inhibited STAT3 expression to contribute to downregulation of VEGF and MMP2 expression within tumors in vivo. This study demonstrates that STAT3 siRNA can effectively inhibit the expression of STAT3 gene within tumors, leading to suppression of tumor growth, prevention of cancer from pulmonary metastasis, and enhancing apoptosis of the transplanted Lewis lung cancer in mice in vivo.

Peptide Inhibitors of HIV-1 Virus Infection Based on Cullin-5

ZHU Ke-tong, ZHANG Xi-zhen, LOU Chao-ping, GUO Bo, DU Juan, WANG Xiao-dan, WU Yong-ge, KONG Wei , YU Xiang-hui

2008, 24(3):  338-343.  doi:

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Virion infectivity factor(Vif) is one of the six accessory proteins of HIV-1 and is necessary for viral infectivity. Human Apolipoprotein B editing complex protein 3G(h-APOBEC3G) is a cytidine deaminase only expressed in “nonpermissive” cells and exhibits virus suppressive activity. With the aid of a Cullin-5 E3 ligase, Vif induces h-APOBEC3G degradation and with the destruction of this ligase, Vif is functionally inactive. Therefore, it is expected that blocking this E3 pathway would be a new therapeutic strategy against HIV-1 infection. In this article, the authors’ took sequence alignment of the N-termini of Cullin-5 and three other members of the Cullin protein family, respectively. A set of small peptides has been synthesized based on the sequence comparison results and possible Vif-Cullin-5 interaction domains. Moreover, it has been demonstrated that several peptides can reduce virus infectivity in “nonpermissive” cells with a dose-responsive manner, but not in “permissive” cells. The results also indicate that the loss of viral infectivity may be because of the increase of APOBEC3G amount in the peptide-treated cells. It is concluded that peptides derived from Cullin-5 can block the APOBEC3G degradation induced by Vif and suppress HIV-1 infectivity. Therefore this study starts a novel strategy for the development of a new HIV-1 inhibitor.

Cloning and Expression of Intracellular Part of Receptor Protein Tyrosine Phosphatase RPTPα and Preparation of Its Polyclonal Antibodies

CHEN Yang , YANG Su-juan , FU Yao , WANG Jia-peng , ZHAO Zhi-zhuang , FU Xue-qi

2008, 24(3):  344-347.  doi:

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A DNA fragment encoding the intracellular part of tyrosine phosphatase RPTPα designated as RPTPα-2D gene was amplified by PCR from a human prostate cDNA library and cloned into the pT7 E. coli expression vector. The resulting plasmid pT7-RPTPα-2D was used to transform Rosetta DE3 E. coli cells. RPTPα-2D was predominately expressed in the insoluble inclusion body and was effectively purified using preparative electrophoresis gels. Polyclonal antibodies were obtained after immunization of a rabbit with purified RPTPα-2D. The antibodies displayed a high titer and sensitivity. This study thus provided a valuable tool for further researches on RPTPα.

Purification and Characterization of a Proteolytic Enzyme from Fig Latex


HUANG Lu, QU He-zhi, ZHANG Lei, DU Shan-shan, YANG Shuo, HAO Dong-yun , WANG Xiao-ping

2008, 24(3):  348-352.  doi:

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Ficin is an important component of plants in Ficus family such as fig latex. It is of special significance in medicine and industry because it exhibits activity throughout a wide range of temperature and pH values. In this work, we purified a component of ficin from the latex homogeneity of Shandong fig trees, and the properties of the purified ficin were studied. The current findings revealed that heavy metal ions were able to inhibit ficin, while DTT, L-cysteine, and β-ME were found to promote ficin activity. It was also observed that the half life of ficin at 65 °C was longer than 1 h and the Michaelis constant(K_m) for casein hydrolyzation was determined to be 1.56 mg/mL. Our study shows that this purified ficin is a cysteine protease.

Decomposition Reaction of Zn-MPA(3-Mercaptopropionic Acid) Complex Under Microwave Irradiation


JIAN Wen-ping , LIU Sheng , LI Jun , YANG Wen-sheng

2008, 24(3):  353-356.  doi:

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The thermal decomposition of Zn-MPA complex was investigated under microwave irradiation. ZnO and ZnS nanocrystals could be obtained by decomposing Zn-MPA(3-mercaptopropionic acid) complex under different reaction conditions. It was found that both the pH value of the solution and the molar ratio of Zn²⁺ and MPA can play an important role in the formation of ZnO and ZnS nanocrystals. MPA mainly acts as an S source or as a complexing agent. This study provides a new route for the controllable preparation of semiconductor nanocrystals.

Preparation, Characterization and Catalytic Performance of La-SO₄²⁻/SBA-15 in Esterification of Acetic Acid with n-Butanol

TIAN Zhi-ming , DENG Qi-gang , SUN Hui , ZHAO De-feng

2008, 24(3):  357-361.  doi:

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La-SO₄²⁻/SBA-15 was synthesized with various amounts of lanthanum via incipient-wetness impregnation. Characterization was done by X-ray diffraction(XRD), transmission electron micrographs(TEM), nitrogen adsorption, FTIR spectroscopic analysis, thermogravimetric analysis, and the total amount of acidity of catalyst was estimated by TPD of NH₃. The results indicate that lanthanum has been incorporated into SBA-15 molecular sieve. The prepared materials(La-SO₄²⁻/SBA-15) keep the highly ordered mesoporous two-dimensional hexagonal structure and do not change the mesoporous channel structure of the support SBA-15. The catalyst showed best catalytic activity in the synthesis of n-butyl acetate. The optimum conditions of the esterification by orthogonal experiments were studied: the molar ratio of n-butanol to acetic acid 1:1.2, the amount of catalyst 7.5%, reaction time 80 min. The yield of n-butyl acetate could reach 93.2% under the optimum conditions. The catalyst was recyclable, cost effective and environmental friendly.

Controllable Synthesis of Titania Nanocrystals with Different Morphologies and Application to the Degradation of Phenol

CHEN Da-wei, SHI Jin-e, YAN Ji-chang, WANG Yue-hong, YAN Fu-cheng, SHANG Shu-xia , XUE Jing

2008, 24(3):  362-366.  doi:

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Titania nanocrystals with different morphologies were prepared using the hydrothermal method via controlling the pH values of solution, the ratio of reactants, temperature, and time of the hydrothermal reaction. The experimental results showed that uniform rod-like titania particles with an average aspect ratio of 6:1 could be obtained under the conditions of pH=11, n(TBOT):n(TEA)=1:2, hydrothermal treatment at 150 °C for 24 h. When pH<10, spherical titania nanocrystals could be obtained; with increasing the pH value, the diameter became smaller. Finally, the smallest size of the particles could reach 7 nm. Nanocrystals with uniformly well-dispersed and perfect crystallographic form were obtained via the above method. Phenol was used as the degradation model for testing the photocatalytical activity of the titania nanocrystals with different morphologies.

Ultra-large Scale Molecular Dynamics Simulation for Nano-engineering

ZHAO Jian-wei, YIN Xing, LIANG Shuai, LIU Yun-hong, WANG Dong-xu, DENG Sheng-yuan , HOU Jie

2008, 24(3):  367-370.  doi:

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In light of the special need of nano-engineering, an ultra-large scale and high-performance molecular dynamics(MD) simulation program was implemented. In many nano-engineering processes, the free boundary condition should be adopted. To meet this particular requirement, a pointer link and dynamic array data structures were employed so that both reliability and accuracy of simulation could be ensured. Using this method, one could realize the MD simulation of the nano-engineering system consisting of several million atoms per single CPU.

Theoretical Studies on N₂H+O Reaction

LÜ Ying-wen , LÜ Wen-cai , SU Zhong-min

2008, 24(3):  371-377.  doi:

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The N₂H+O potential energy profile was studied at the CCSD(T)/6-311G++(df,p)//MP2/6-311G(d,p) level. Reactions associated with four intermediates(cis-HNNO, trans-HNNO, NNHO, and NNOH) were investigated. The results indicate that N₂H+O reaction toward H+N₂O is more favored than that toward N₂+OH, consistent with previous experimental studies. The pathways for the two reactions are found to go through cis-HNNO, transition state, and finally to the products. The N₂H+O→NH+NO reaction was studied in detail. Product NO in such a reaction is likely to occur via cis-HNNO, followed by trans-HNNO, and finally dissociates into NH+NO. These results suggest that N₂H+ONH+NO is an important channel in NO production.

Preparation and Characterization of Titania-grafted Poly(styrene-divinybenzene) Nanocomposite Microspheres

LI Sen , CHENG Jiang , WANG Kuan , YANG Zhuo-ru

2008, 24(3):  378-382.  doi:

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Titania-grafted poly(styrene-divinylbenzene)(TiO₂/PSt-DVB) nanocomposite microspheres were prepared by an open-ring reaction and radical grafting copolymerization method. The TiO₂ nanoparticles were first modified by attachment of epoxy groups to their surfaces to provide reactive groups that could covalently bond to the polymer (PSt-DVB) microspheres. The nanocomposite obtained was characterized by FTIR, SEM, XRD, and TGA analyses as well as UV-Vis spectrophotometry. The results indicated that the TiO₂ nanoparticles were uniformly grafted onto the surface of the polymer microsphere producing grain sizes of about 5―10 μm. The modified TiO₂ showed better UV absorbing property than the unmodified form, and the nanocomposite also retained the same UV absorbing property as the free modified TiO₂ nanoparticle.

Letter

Preparation and Electrode Performance of Ferrihydrites for Rechargeable Lithium Batteries

WANG Hong , LAI Xiao-yong , XIA Wei , YU Ran-bo , MAO Dan , XING Chao-jian , YAO Jian-xi , WANG Dan , LI Xiao-tian

2008, 24(3):  383-384.  doi:

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We first investigated the potential of 2-line ferrihydrite for application in electrode materials of lithium ion battery. Besides the conventionally rapid hydrolysis route, a novel selective extraction route from layered double hydroxides (LDHs) and their calcinates (LDOs) has been designed and employed to prepare 2-line ferrihydrite. The electrochemical results reveal 2-line ferrihydrites from LDHs is one of the best of them, possessing a high discharge capacity of 133.4 mA·h·g^–1 after the activation process and a good cycle performance remaining 115.4 mA·h·g^–1 after 21 cycles.

Research Note

An Efficient and Simple Reaction: Solvent-Free Preparation of Rosolic Acid under Microwave Irradiation

LI Min , ZHANG Qi-jun , YANG Jun-wei , TONG Shan-ling , YANG Ke-er , XIAO Feng-shou , K. P. Ng. Dennis , YAN Yan

2008, 24(3):  385-388.  doi:

Abstract ( )  

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An acid-base indicator, rosolic acid, was prepared under solvent-free conditions irradiated by microwave. The product was characterized by means of UV-Vis, IR, ¹H-NMR and CCD methods. The reaction conditions were optimized and a possible mechanism was established based on XRD and IR determinations. Electrochemical properties of rosolic acid product acid product was also examined.