Table of Content

10 August 2009, Volume 30 Issue 8

Previous Issue    Next Issue

Contents

高等学校化学学报2009年第30卷第8期目次

2009, 30(8):  0. 

Asbtract ( )   PDF (834KB) ( )  

Related Articles | Metrics

下期目次预览

2009, 30(8):  0. 

Asbtract ( )   PDF (1070KB) ( )  

Related Articles | Metrics

Articles

Silver Colloid Induced Noncovalent Surface Modification of Multi-Walled Carbon Nanotubes

XIA Xiao-Dong*, SHEN Guo-Li, YU Ru-Qin

2009, 30(8):  1477-1480. 

Asbtract ( )   PDF (318KB) ( )  

References | Related Articles | Metrics

A facile noncovalent surface modification method for multi-walled carbon nanotubes(MWNTs) through soluble starch to be prearranged helical state produced by complexing with silver colloid was described. The starch modified MWNTs show great ease of exfoliation into water and SEM analysis shows a significant debundling upon silver colloid treatment. Amylatic reaction, IR and EDS analysis indicate the MWNTs surface modification by soluble starch.

Study on the Preparation and Electrochemical Property of Cu²⁺ Ion Doped Todorokite

QIU Guo-Hong, YANG Dan, FENG Xiong-Han, ZHANG Xu-Liang, CHEN Xiu-Hua, ......

2009, 30(8):  1481-1486. 

Asbtract ( )   PDF (579KB) ( )  

References | Related Articles | Metrics

The todorokite manganese oxides were widely examined as lithium insertion hosts for cathodes in rechargeable lithium batteries, catalytic materials, adsorbents, etc. Cu²⁺ doped todorokites also showed potential as electro-catalytic materials with selectivity. In this paper, the single and Cu²⁺ ion doped todorokites were prepared with different processes, and the influences of reaction conditions on product purity were investigated. The electrochemical activity and stability of todorokites were studied by powder microelectrode. It was found that the single todorokite or with Cu²⁺ doping on structure could be formed at atmosphere pressure by a refluxing process. The Cu²⁺ ion doped todorokite in the tunnel could only be synthesized in autoclave at a relative high temperature and pressure, and reaction temperature was the main influential factor for synthesis of single phase materials in the process. Todorokites exhibited high electrochemical activity and stability in solutions with high pH value. Cu²⁺ ion doping on structure would enhance the electrochemical activity and stability of todorokite, but it had a negative effect for electrochemical characters with Cu²⁺ ion doping in the tunnel. The structure of todorokite with Cu²⁺ doping in the tunnel was further proved by cyclic voltammetry with help of powder microelectrode.

Luminescent Characteristics and Crystallographic Sites of Ce³⁺ Activated LiSrBO₃ Phosphor

LI Pan-Lai*, WANG Zhi-Jun, WANG Ying, YANG Zhi-Ping, GUO Qing-Lin

2009, 30(8):  1487-1491. 

Asbtract ( )   PDF (451KB) ( )  

References | Related Articles | Metrics

The blue white LiSrBO₃∶Ce³⁺ phosphor was synthesized with solid-state method. The emission spectrum of LiSrBO₃∶Ce³⁺ phosphor shows one dissymmetrical band at 436 nm. The excitation spectrum for 436 nm emission has broad band at 369 nm. The crystallographic sites of Ce³⁺ in LiSrBO₃ were calculated by Van Uitert formula. The results show that the emission band centered at 433 nm originates from the Ce³⁺ center of the nine compounds, the other emission band centered at 469 nm originates from the Ce³⁺ center of the eight compounds. The effect of Ce³⁺ molar fraction on luminescent intensity of LiSrBO₃∶Ce³⁺ phosphor was investigated, the result shows that the luminescent intensity firstly increases with increasing Ce³⁺ molar fraction, then decreases, and reaches the maximal value at 3% Ce³⁺. The concentration quenching mechanisms are the D-D interaction by Dexter theory. Under the condition of doping charge compensation Li⁺, Na⁺ and K⁺, the emission spectrum intensity of LiSrBO₃∶Ce³⁺ was heightened. The relative emission spectrum of the blue white-emitting InGaN-based LiSrBO₃∶Ce³⁺ LED was investigated, and the CIE chromaticity of InGaN-based LiSrBO₃∶Ce³⁺ LED is (x=0.289, y=0.293).

Hydrothermal Synthesis and Properties of New Cathode Material Li_0.86V_0.8O₂

HU Fang, DU Fei , CHEN Yan, WEI Ying-Jin, MING Xing, CHEN Gang, ......

2009, 30(8):  1492-1496. 

Asbtract ( )   PDF (507KB) ( )  

References | Related Articles | Metrics

The new cathode material Li_0.86V_0.8O₂ was synthesized by two-steps reaction. The material crystallizes in the layered rhombohedral structure with space group R3m. The mechanism of phase evolution was studied in different alkalinity under hydrothermal condition. It is found that the hydrothermal reaction does not work in low LiOH·H₂O concentration. The single phase material of Li_0.86V_0.8O₂ can only be obtained in the concentration of 2.5 mol/L. Through X-ray photoemission spectrum, the binding of 516.4 and 523.1 eV can be attributed to the V_2p3/2⁴⁺ and V_2p1/2⁴⁺, which confirm the quadrivalent state of V ion in Li_0.86V_0.8O₂. With a current density of 7.4 mA/g, the charge capacity of Li_0.86V_0.8O₂ is 163 mA·h/g in the first cycle, and the first discharge capacity of the materials is 113 mA·h/g. After 20th cycles, the discharge capacity is still 80 mA·h/g, which shows good electrochemicalstability.

Preparation of Fluorescent Carbon Nanoparticles by Pulsed Laser

HU Sheng-Liang*, BAI Pei-Kang, CAO Shi-Rui, SUN Jing

2009, 30(8):  1497-1500. 

Asbtract ( )   PDF (314KB) ( )  

References | Related Articles | Metrics

Ultrafine carbon nanoparticles were prepared by irradiating graphite suspension employing millise-cond pulsed laser. Carbon nanoparticles emitted strong visible light after surface modification using PEG 2000. The characteristic of two-photon fluorescence was detected in the experiment. Fluorescence quantum yield of carbon nanoaprticles was 6.3% employing quinine sulfate in 0.1 mol/L H₂SO₄ as the standard reference sample. Graphite particles were heated up and sublimed by laser energy absorption; therefore, a large amount of carbon vapors were produced. After pulse duration, the carbon vapors cooled quickly under the liquid medium and formed carbon nanoparticles by condensation. Surface energy traps were created on the carbon nanoparticles after surface modification and resulted in the visible light emission due to the quantum confinement effects. Fluorescent carbon nanoparticles show high potential on the application of biology labeling and life science due to many advantages such as low cytotoxicity, biocompatibility, and chemically inert.

Synthesis and Properties of Novel Porphyrin Modified by Pyridine Derivative

LIU Mei, YAN Wei-Wei, ZANG Na, RUAN Wen-Juan*, ZHU Zhi-Ang

2009, 30(8):  1501-1508. 

Asbtract ( )   PDF (709KB) ( )  

References | Related Articles | Metrics

A new kind of tailed zinc porphyrin modified by pyridine derivative(o-PyOC₆H₁₂OTPPZn) was synthesized and characterized by elementary analysis, UV-Vis, ¹H NMR, IR, and MS spectra. The axial coordination reaction was studied between o-PyOC₆H₁₂OTPPZn and pyridine derivatives by UV-Vis spectra titration. The binding constants decreased in the order of K(4-MePy)>K(Py)>K(3-MePy)>K(2,4,6-triMePy)>K(2-MePy) for pyridine derivatives. The results show that the capability of axial ligands decreased in the sequence of 4-MePy>Py>3-MePy>2,4,6-triMePy>2-MePy. Moreover, the lowest energy conformations of the complexes between the zinc porphyrin and pyridine derivatives were obtained by simulated annealing and the results explained the experiment results well. The nonlinear optical property of o-PyOC₆H₁₂OTPPZn was investigated by Z-scan experiment. Reverse saturated absorption of the compound was observed.

Spectroscopic Studies on the Interaction of Murexide and Murexide-Copper Complex with Human Serum Albumin

MA Ping, CHI Yan-Hua*, ZHUANG Jia, WANG Han, CHEN Liang, LIU Xu, DONG Fa-Qin

2009, 30(8):  1509-1515. 

Asbtract ( )   PDF (645KB) ( )  

References | Related Articles | Metrics

The interactions of human serum albumin(HSA) with murexide(Mx) and murexide-copper complex(Mx-Cu²⁺) were investigated by fluorescence spectroscopy and Fourier transform infrared spectroscopy(FTIR) under simulative physiological conditions. The results show Mx and Mx-Cu²⁺ could quench the intrinsic fluorescence of HSA by static quenching and hydrophobic interaction was the predominant intermolecular force. The binding constant of Mx and HSA was increased in the presence of copper(Ⅱ). According to fluorescence resonance energy transfer(FRET), the distancer between donor(HSA) and acceptor(Mx and Mx-Cu²⁺) were calculated to be 2.82 and 2.53 nm, the ternary system energy transfer efficiency E′> binary system E, which showed the copper ion acts as the energy transfer agency. The synchronous fluorescence and FTIR study suggested that Mx and Mx-Cu²⁺ can cause almost the same changes in the secondary structure of HSA. Upon binding with Mx or Mx-Cu²⁺ complex, the α-helix structure was reduced more than 8%, the β-sheet reduced 1%, while the β-turn increased 6%, and the random coil increased 4%. The results show that the main factor of secondary structure changing is Mx.

Microwave-induced Synthesis and Spectral Properties of New 4-Hydroxycoumarin Derivatives

DONG She-Ying*, LI Jing, HUANG Ting-Lin

2009, 30(8):  1516-1521. 

Asbtract ( )   PDF (465KB) ( )  

References | Related Articles | Metrics

Three kinds of 4-hydroxycoumarin derivatives, 3,3′,3″,3″′-ethylenetetrakis-4-hydroxycoumarin(b), 3,3′-benzylidenedi-4-hydroxycoumarin(c) and 4-hydroxycoumarin-1,4-naphthaquinone(d) were synthesized from 4-hydroxycoumarin(a) under microwave irradiation and characterized by means of elemental analysis, IR, ¹H NMR and MS. The compounds a—d were studied by ultraviolet-visible absorption spectra and fluorescence spectroscopy. It was confirmed that the big π-conjugated, symmetrical compound b had better fluorescence in solution and possessed high molar extinction coefficient. When the concentration of compound b was in the range of 0.50—1.50×10^-4 mol/L, the fluorescence intensity linearly increased with decreasing concentration. In the range of pH=1.18—6.09, fluorescence intensity increased with increasing of pH, and in the range of pH=8.36—11.98 fluorescence intensity increased with decreasing of pH values. In addition, fluorescence enhancing was significantly observed in the presence of BSA and DNA.

Study on Role for Propecting HUVEC Damaged by Urate and Content Variation of Alkaloids Components in Ermiao Wan Categorized Formula

YIN Lian*, DENG Hai-Shan, ZHU Xiao-Qin, LI Xin, DUAN Jin-Ao, DING An-Wei

2009, 30(8):  1522-1527. 

Asbtract ( )   PDF (467KB) ( )  

References | Related Articles | Metrics

To reveal the compatibility of traditional Chinese medicine, the material foundation playing major role of Ermiao Wan categorized formula and their compatibility content variation was studied. The activity of the combined effective components by orthogonal design in its relevant herbs were evaluated for protecting HUVEC damaged model induced by urate, the results indicated that the alkaloids components of Phellodendron chinense(PC) of Ermiao Wan play a major role in its categorized formula. The fingerprint of alkaloids components in PC and Ermiao Wan categorized formula were analyzed and compared by high performance liquid chromatography-electrospray ionization-mass spectrometry(HPLC-ESI-MS). Twelve alkaloids were detected in the fingerprint of alkaloids. The contents of some alkaloids were found to be reduced, on the contrary, the contents of total alkaloids were increased 122.9% in Ermiao Wan, and reduced 80.7%, 60.2%, 94.2% in its categorized formula. From the chemical point of view, the material foundation of basic formula plays major role in its categorized formula, the variation of relative content of alkaloids are in accord with the virtue of Ermiao Wan categorized formula.

Liquid Chromatography-Tandem Mass Spectrometric Assay for the Determination of CTN986 and Its Deglycosylation Products in the Rat Brain Dialysate

GUO Ji-Fen, ZHANG Shao-Dong, MENG Fan-Hua, ZHAO Yi-Min*

2009, 30(8):  1528-1532. 

Asbtract ( )   PDF (409KB) ( )  

References | Related Articles | Metrics

An HPLC-MS/MS method was developed for the determination of CTN986 and its two deglycosylation products, rutin and hirsutin, in the rat brain dialysate. The dialysate samples were analyzed by offline liquid chromatography-tandem mass spectrometry. The separation was performed using a Zorbax C8 column with an isocratic mobile phase consisted of methanol/isopropanol/water/formic acid(20∶10∶70∶0.1, volume ratio). An API 3000 tandem mass spectrometer equipped with electrospray ionization source was used as detector and was operated under the positive ion mode. Multiple reactions monitoring(MRM) mode was used to quantify three analytes. Calibration was performed by external standardization and regression curves were constructed ranging from 2 to 500 ng/mL for each compound. The intra- and inter-day precision values were below 15% and accuracy was between -4% and 13% for all quality control samples. As a result, the procedure proved to be very suitable for routine analysis. This quantitation method was applied to the pharmacokinetic study of CTN986 in the brain dialysate samples from rats following oral administration.

Rapid Quantitative Detection of Toxic Diethylene Glycol in Toothpaste by Extractive Electrospray Ionization Ion Trap Mass Spectrometry

DING Jian-Hua, YANG Shui-Ping, LIU Qing, WU Zhuan-Zhang, CHEN Huan-Wen*, ......

2009, 30(8):  1533-1537. 

Asbtract ( )   PDF (390KB) ( )  

References | Related Articles | Metrics

Using ammonium acetate methanol solution(10 μmol/L) as the spray solvent, a novel method based on reactive extractive electrospray ionization(EESI) ion trap mass spectrometry was developed for the rapid determination of diethylene glycol(DEG) in toothpaste products, which are typical colloidal complex samples containing nano-scale particles in matrices. Under the optimized working conditions, DEG formed non-covalently bound complexes with NH₄⁺, Na⁺ and K⁺ rather than the protonated molecules in the mass spectrum. About 0.1 g of the toothpaste products were required for direct sensitive analysis with EESI-MS, the whole procedure was completed within less than 2 min. Furthermore, the qualitative demonstration and quantitative analysis of DEG of the paste products was also done by the EESI-MS and EESI-MS/MS spectra. This method can be used for the rapid and selective determination of low-level DEG in toothpaste products, and it is a useful method for the rapid determination of low-level components in the viscous nano-materials.

Real-time Monitoring Continuous Replication of DNA Leading Strand in vitro Based on Molecular Beacon

MENG Xiang-Xian, YANG Xiao-Hai, WANG Ke-Min*, GUO Qiu-Ping, LI Jun, TANG Zhi-Wen

2009, 30(8):  1538-1542. 

Asbtract ( )   PDF (382KB) ( )  

References | Related Articles | Metrics

Real-time monitoring of replication of DNA leading strand using molecular beacon in vitro was reported. DNA replication plays a pivotal role in life process. DNA replication is usually assayed by denatured gel electrophoresis and autoradiography, which are complex, time-consuming, and incapable of acquiring the dynamic data in real time. We employed molecular beacon as the probe and template for DNA replication and converted directly replication information into fluorescence signal. The replication information of DNA leading strand was obtained conveniently and accurately using molecular beacon. This method would provide a strategy for real-time monitoring DNA replication and for further research of replication dynamic data and some deseases associated with DNA replication.

Near Infrared Spectroscopy Combined with Principal Component Analysis Applied to Diagnosis of Endometrial Carcinoma

XU Ke, XIANG Yu-Hong, DAI Yin-Mei, ZHANG Zhuo-Yong*

2009, 30(8):  1543-1547. 

Asbtract ( )   PDF (359KB) ( )  

References | Related Articles | Metrics

The feasibility of near infrared(NIR) spectral feature extraction and early diagnosis of endometrial carcinoma were developed by chemometrics methods. Few papers have been reported about the studies on NIR spectra features of endometrial carcinoma so far. In this study, the NIR spectra of 154 specimens of endomet-rium were collected, and spectral data were analyzed by principal component analysis. In order to improve the classification, selection of wavelength range and spectral pretreatment methods were discussed. The results suggested that samples of malignant, hyperplasia and normal endometrium were classified correctly. Moreover, endometrium at various differentiation stages could also be identified, which provided reliable evidence for early diagnosis in endometrial carcinoma. This approach was proved to be rapid and convenient, which is able to be developed as a non-invasive diagnosis method for cancer.

Fabrication of Seamless PMMA Microfluidic Chips with and Without a Glass-fiber Mixer by Controlled in situ Polymerization

WANG Hai, CHEN Yi*

2009, 30(8):  1548-1552. 

Asbtract ( )   PDF (752KB) ( )  

References | Related Articles | Metrics

A new method was established for the fabrication of seamless polymer microfluidic chips. By the method, seamless PMMA microfluidic chips were easily fabricated by in situ polymerization of monomer solution casting on a channel mold temporarily fixed with pieces of fine iron wires by a magnet beneath the polymerizing container. Seamless channels were formed by bonding two pieces of 70%—80% polymerized PMMA slides of which one was preprinted with channels. Glass-fibers-embedded microfluidic mixers have also been fabricated in the same way where a section of about 2 mm glass-fiber bundle was inserted between two wires before casting polymerizing solution. With such a mixer, ideal mixing was easily achieved at Re≥22. This method features easy manipulation and low cost, it fits ordinary chemistry laboratories, requiring no clean room or lithographic facilities.

Research on Characterization and Biocompatibility of Nano-bacterial Cellulose Membrane

WANG Zong-Liang, JIA Yuan-Yuan, SHI Yi, CONG Deng-Li, CHEN Yan-Yan, ......

2009, 30(8):  1553-1558. 

Asbtract ( )   PDF (944KB) ( )  

References | Related Articles | Metrics

Bacterial cellulose membrane, possessing nanofibers, an ultrafine 3-dimensional network and proper porosity, was prepared by static culture of Acetobacter xylinum and characterized by light microscope, SEM(Scanning electron microscope) and AFM(Atomic force microscope). The results show that BC has extremely fine network of nano-structure, the pore size of freeze-dried BC is 0.6 to 2.8 μm; the width of cellulose is 50 to 80 nm. By measuring their dry weight and wet weight, the porosities of air-dried BC and freeze-dried BC were determined, respectively. The porosity of air-dried and freeze-dried BC is about 70% and 90%, respectively. The water vapor permeability of air-dried BC is quite excellent because the existence of a large number of hydroxyl. BC co-culture with fibroblasts(FBs) and chondrocytes, respectively, and subcutaneous implant of FBs-BC composition into nude mouse. The composition is well intergrated into the skin of nude mouse. FBs and chondrocytes form continuous cell layer on the surface of BC and the expression of GFP is normally. The results demonstrate that BC membrane is suitable for cell attachment and proliferation, and shows better biocompatibility. It is expected to become a promising tissue engineering scaffold.

Synthesis of Bulky Epoxides via Asymmetric Epoxidation of Bulky Olefins

SUN Yun-Kai, YANG Nian-Fa*, WU Shi, LING Ying, OUYANG Kun-Bing

2009, 30(8):  1559-1565. 

Asbtract ( )   PDF (414KB) ( )  

References | Related Articles | Metrics

It has been found that the optically active epoxide (S)-4,4,4-triphenyl-1-butene oxide[or its (R) isomer], which bears bulky pendant, can be polymerization to form helical polyether. To obtain the helical structure information of other polyethers bearing bulky pendant, the method for synthesis of optically active bulky epoxide with multifarious structure is necessary. The optically active bulky epoxide which contains a methene between the bulky group and epoxy group has been synthesized by coupling a bulky alkyllithium and optically active epichlorohydrin. However, this method is not suitable for the synthesis of other optically active bulky epoxides. In this article, seven chiral epoxides with high e.e. value were synthesized via synthesizing bulky olefins at first and then converting the olefins to the corresponding optical epoxides with oxone(KHSO₅) as an oxidant and a chiral ketone as a catalyst. The D-fructose ketone derivant had high enantioselectivity to epoxidation of trisubstituted olefins(the e.e. values of epoxides were 96.8%—99.5%), but its enantioselectivity to the epoxidation of monosubstituted olefins was not good. (2S,5R)-2-Isopropyl-5-methylcyclohexanone also showed an enantioselectivity to the epxidation of olefins but the enantioselectivity was poor in spite of the cases of monosubstituted, disubstituted or trisubstituted olefins(the e.e. values of epoxides were 25.6%—34.1%).

ESI Fragmentation Studies of Four Tea Catechins

LIU Guo-Qiang, DONG Jing, WANG Hong, WAN Le-Ren, HASHI Yuki*, CHEN Shi-Zhong*

2009, 30(8):  1566-1570. 

Asbtract ( )   PDF (423KB) ( )  

References | Related Articles | Metrics

The fragmentation pathways of tea catechins(two group stereoisomers ) were studied via the ion-trap time-of-flight(IT-TOF) mass spectrometer with the advantages of high mass accuracy, high resolution, multistage analysis. Hydrogen/deuterium exchange method was used to elucidate the fragmentation processes. The results show that catechin stereoisomers possess the same fragmentation pathways and cannot be differen-tiated even in MSⁿ spectra. We can locate the loss of CO₂ and C₂H₂O in MS² spectra from EC/C to A ring and B ring, respectively. The ions of ^1,4A^-, ^1,3A^-, ^1,2A^- and [M-H-B ring]^- were characteristic product ions for EC/C, and it could be used to propose the substituent group of A ring through the m/z shift of these ions. The ion at m/z 169 corresponding to the gallic acid anion was characteristic fragmentation of ECG/CG, which was great helpful for differentiating ECG/CG and EC/C.

Alcohol-induced Conformation of Myoglobin

JIANG Dan, CHU Yan-Qiu, DING Chuan-Fan*

2009, 30(8):  1571-1576. 

Asbtract ( )   PDF (503KB) ( )  

References | Related Articles | Metrics

This paper mainly reports the alcohol-induced effection. Accoding to the mass spectrometry, we got a lot differences among myoglobin conformations induced by different alcohol at pH=4.0, 30%(volume fraction) alcohol. The results show that alcohol′s molecular structures effect Mb conformation. Besides, we found that the alkyl′s number enhanced denaturation effection. Fluorine substituent could stabilize hMb and aMb selectively a certain extent. we also proved the regularity summarized as above farther and got more useful information of Fe ion′s coordination and election spin state via CD spectroscopy and UV-Vis Soret Absorption.

Chiral Resolution of D,L-Valine by Immobilized Cells with Acetylornithine Deacetylase Activity

ZHANG Fei, XIONG Ji-Bing, LIU Jun-Zhong, LIU Peng-Gang, JIAO Qing-Cai*

2009, 30(8):  1577-1580. 

Asbtract ( )   PDF (241KB) ( )  

References | Related Articles | Metrics

D-Amino acids are widely used intermediates in pharmacy. D-Amino acids can be produced by chiral separation of D,L-amino acids racemate. The stereospecific hydrolysis of N-acetyl-D,L-amino acids by microbial enzymys is one of the most extensively used procedures in optical resolution of D,L-amino acids. In this report, a new method of chiral resolution of D,L-valine by immobilized cells with acetylornithine deacetylase activity was developed. The optimum reaction conditions were 200 mmol/L N-acetyl-D,L-valine and 0.2 g/mL(or 100 U/mL) of immobilized cells with 0.1 mmol/L CoCl₂ as activator at pH=6. After 2—3 h incubation at 50 ℃, 95 mmol/L L-valine was obtained. In continuous use of immobilized cells for 10 times, the average conversion rate against N-acetyl-L-valine was 90.8%. The results display great potential in industrialization. This is the first report of chiral resolution of D,L-valine by acetylornithine deacetylase(ArgE).

Interaction Between PVA and Staphylokinase and Its Influence on the Secondary Structure of Staphylokinase

WANG Gai-Zhen, HE Jin-Tian*, ZHOU Zhi-Tao, ZHU Yu-Kun, GUO Yin-Yin

2009, 30(8):  1581-1585. 

Asbtract ( )   PDF (311KB) ( )  

References | Related Articles | Metrics

Gel filtration chromatography, fluorescence spectrophotometry, differential scanning calorimetry(DSC), Fourier transform infrared spectrophotometry(FTIR) and fibrinolytic activity analysis were used to investigate the interaction between polyvinyl alcohol(PVA) and staphylokinase under physiological conditions. The results show that staphylokinase can form complex with PVA. The results of fluorescence spectrophotometry and DSC suggested that the interaction of PVA with staphylokinase did not destroy advanced structures of staphylokinase. FTIR was combined with resolution enhancement technique Fourier deconvolution and Gaus-sian curve-fitting procedures to quantitate the spectral information from the amide Ⅰ bands of staphylokinase within the freeze-dried mixture of PVA and staphylokinase. The results show that the interaction of PVA with staphylokinase decrease β-sheet content which is associated with intermolecular interaction and protein denaturation. Analysis of fibrinolytic activity of the staphylokinase show that interaction of PVA with the staphylokinase do not destroy the tertiary structure of the staphylokinase.

Primary Studies on the Properties of Trichosanthin After Site-directed Mutagenesis and PEGylation

AN Qun-Xing, LEI Ying-Feng, YANG Jing, LI Zhi-Dong, MU Shi-Jie*, XU Zhi-Kai*

2009, 30(8):  1586-1591. 

Asbtract ( )   PDF (552KB) ( )  

References | Related Articles | Metrics

To construct a PEGylated trichosanthin(TCS) mutein by site-directed PEGylation and analyse its bioactivities, immunogenicity, acute toxicity and pharmacokinetics. By computer modeling, the site KR173-174 was identified as potential antigenic determinant of TCS. Then, a TCS mutein namely TCS_KR173-174CG was constructed by site-directed mutagenesis and expressed in E.coli BL21(DE3). After that, the bioactivities, immunogenicity, acute toxicity and pharmacokinetics of the mutant TCS and PEGylated TCS were examined. It was shown that the bioactivities of the mutant TCS were similar to wild-type TCS(wTCS), but with much lower immunogenicity. The PEGylated TCS show a significant decrease in immunogenicity and acute toxicity, and a marked increase in plasma half-life when compared with unmodified TCS. But there is a problem of activity reduction. The site-directed mutagenesis and PEGylation of TCS provide a new approach for reconstructing TCS.

Theoretical Studies on the Potency of Novel Matrix Metalloproteinases Inhibitors

LI Dai-Lin, ZHENG Qing-Chuan, ZHANG Hong-Xing*, JI Hai-Tao, YANG Jin-Gang, .....

2009, 30(8):  1592-1595. 

Asbtract ( )   PDF (298KB) ( )  

References | Related Articles | Metrics

By means of molecular mechanics and molecular dynamics methods, the binding modes and inte-ractions between newly found matrix melalloproteinases(MMPs) inhibitors, Pyrogallic acid and Myricetin, and MMP-7 were investigated in the present study. The calculated results show that the binding affinity between Myricetin and MMP-7 is higher than that between Pyrogallic acid and MMP-7 when they bind to MMP-7, thus Myricetin is more potent on MMP-7 than Pyrogallic acid. This is in agreement with the inhibitory activity order from experiments. Furthermore, the density functional theory calculation results indicate that the inhibitors can bind to the zinc ion of MMPs with ZBG in a monodentate way. The theoretical results may be helpful for the structure-based design of inhibitors with improved potency.

Theoretical Study of the Reaction Mechanism for the Formation of DNA Adducts by α-Hydroxy-nitrosopyrrolidine

LI Lan*, WANG Hong, NIU Xiao-Juan, LI Zong-He

2009, 30(8):  1596-1599. 

Asbtract ( )   PDF (311KB) ( )  

References | Related Articles | Metrics

The reaction mechanism for the formation of ultimate carcinogens diazohydroxide(B), diazonium(C) and oxoniumions(D) by α-hydroxylation-NPYR and the alkylation process of C and guanine were investigated including solvent effects at the B3LYP/6-31G** level. The formation of ultimate carcinogens involves isomerization and protonation. And the process is relatively easy to occur. The alkylation reaction by ultimate carcinogen C and N7 site of guanine is an S_N2 process, and forms DNA adduct F and G. Adduct G is isomerized by F. The isomerization energies are relatively high(in the gas phase: 244.77 kJ/mol; in solvent of water: 234.83 kJ/mol), which is consistent with the experiment that adduct F is the primary alkylation product.

Graphical Representation of Molecular Charge Distribution in ABEEM Model

YANG Zhong-Zhi*, LI Yang, GONG Li-Dong, ZHAO Dong-Xia

2009, 30(8):  1600-1604. 

Asbtract ( )   PDF (389KB) ( )  

References | Related Articles | Metrics

The charge distribution calculated by the Atom-bond electronegativity equalization method σ-π model(ABEEM σ-π) which is based on the density functional theory and electronegativity equalization me-thod, especially the charge distribution of bond charge and lone-pair electron, is programmed for graphical representation with the Matlab software. This can provide a clear and vivid knowledge for molecular charge distribution. The adenine, deoxyadensine monophosphate, and the Markov electrophilic addition reaction of propylene and HCl, are taken as examples to show the graphical representations of the charge distributions.

Density Functional Studies of Magnetic Exchange of Biheteroatom 11-Heteropoly Complexes: [M(H₂O)XW₁₁O₃₉]^7-(X=Fe^Ⅲ, Co^Ⅲ; M=Co^Ⅱ)

FANG Liang, GUAN Wei, YAN Li-Kai, SU Zhong-Min*

2009, 30(8):  1605-1610. 

Asbtract ( )   PDF (503KB) ( )  

References | Related Articles | Metrics

The magnetic exchange interactions for the biheteroatom 11-heteropoly complexes: [M(H₂O)XW₁₁O₃₉]^n-(Ⅰ: X=Fe^Ⅲ, M=Co^Ⅱ; Ⅱ: X=Co^Ⅲ, M=Co^Ⅱ) were investigated via density functional theory combined with broken-symmetry approach(DFT-BS) method. The calculated J values are -35 cm^-1(Ⅰ) and -44 cm^-1(Ⅱ), respectively, which show that antiferromagnetic exchange interactions exist in these complexes. The order of the absolute value of J is: |J(Ⅰ)|<|J(Ⅱ)|, indicating the increase of coupling interaction from system Ⅰ to Ⅱ. With the change of the heteroatom X via Fe^Ⅲ(Ⅰ)→Co^Ⅲ(Ⅱ), the spin densities on bridge oxygen atoms O_b and O_b2(O′_b2) increase. Furthermore, from the comparison of BS magnetic orbitals in system Ⅰ and Ⅱ we find the overlap of relative orbitals in system Ⅱ enlarges. Consequently, a stronger antiferromagnetic coupling arises in system Ⅱ than in Ⅰ.

Molecular Dynamics Simulation for Diffusion of 1-Butene and n-Butane in MCM-22 Zeolite

ZHANG Guo, ZHENG Qing-Chuan, ZHOU Xin, BAI Fu-Quan, LIU Tao, ZHANG Hong-Xing*

2009, 30(8):  1611-1614. 

Asbtract ( )   PDF (377KB) ( )  

References | Related Articles | Metrics

The molecular dynamics techniques were used to simulate the diffusion of 1-butene and n-butane in purely siliceous ITQ-1 zeolite. The mean square displacement(MSD) plots, diffusion trajectories, and diffusion coefficients of 1-butene and n-butane were obtained. The results show that the molecules of 1-butene and n-butane can diffuse in the different independence channel systems of ITQ-1 zeolite at 400 K; the diffusion capability of 1-butene is less than that of n-butane. The differences in diffusivity were observed between 1-butene and n-butane, especially in the sinusoidal 10 member ring system. Similar features in the diffusivity were observed in the supercages. The diffusion and migration of 1-butene and n-butane mainly occurred in supercage system. On the other hand, the diffusion of those adsorbates at the center of the supercage is easier than those at the upper and lower of the supercage. It indicated that the reaction of the skeletal isomerization happen in 10-MR channel systems.

Interaction Between Cation and Anion in Ion-pairs of [EPy][BF₄] and [EPy][PF₆] in Gas and Liquid Phases

WAN Hui, WANG Xiao-Lu, GUAN Guo-Feng*

2009, 30(8):  1615-1620. 

Asbtract ( )   PDF (449KB) ( )  

References | Related Articles | Metrics

The geometry structure optimization and frequency analysis of ion pairs of ionic liquids 1-ethylpyridinium tetrafluoroborate([EPy][BF₄]) and 1-ethylpyridinium hexafluorophosphate([EPy][PF₆]) were studied using ab initio method and density functional theory at HF/6-31G and B3LYP/6-311+G(d,p) level. Structure and interaction of ionic liquids in liquid phase were investigated by conductor-like polarizable conti-nuum model(CPCM). The most stable structures in gas and liquid phases and infrared spectra of two ionic liquids were obtained. Hydrogen bonding interaction between anion and cation was confirmed by geometry parameters of two ion pairs. The simulated infrared spectra agreed well with the experimental spectra. Natural bond orbital(NBO) analysis was performed to analyze atomic charge distribution and charges transfer in [EPy]⁺ cation and ionic liquids. The results show there are electrostatic interaction and hydrogen bonding interaction between cation and anion of ionic liquids. By means of geometry parameters, interaction energy and NBO analysis, because of neutralization of surrounding charges, interaction in liquid phase becomes smaller.

Influence of Acid Radical Ions upon Photoluminescence Properties of Anodic Aluminum Oxide

LI Yan, WANG Cheng-Wei*, LI Shou-Yi, LIU Wei-Min

2009, 30(8):  1621-1624. 

Asbtract ( )   PDF (362KB) ( )  

References | Related Articles | Metrics

Photoluminescence(PL) properties of anodic aluminum oxide(AAO) membranes with an ordered nanopore array formed in a mixture of sulfuric acid and oxalic acid solution with various volume ratios by two-step anodizing process were investigated under an excitation at 250 nm. Measurements reveal that the PL band in the wavelength range of 350—450 nm originates from optical transitions from oxygen vacancies, the 288 nm and 328 nm peaks attribute to the impurities of SO₄^2- and C2O₄^2- in AAO, respectively. With the increasing ratio of SO₄^2- vs. C₂O₄^2-, the intensity of 328 nm peak reaches a maximum value and then decreases, but the peak located at 288 nm vanishes nearly, then appears gradually. Analyse suggests that there is likely to be nonradiative energy transfer between the two kinds of PL centers originated from SO₄^2- and C₂O₄^2-. An energy transfer mechanism was proposed to explain the behaviors of the emission at 328 nm, and it was tentatively suggested by the PL properties of AAO membranes with dual-layered structure fabricated from sulfuric acid and oxalic acid.

Preparation of Ce_0.1+xTi_0.5-xAl_0.2Y_0.1La_0.1O_1.8 and Its Application in Three-way Catalyst

WANG Kang-Cai, LIU Zhi-Min, WANG Jian-Li, CAI Li, CHEN Yao-Qiang, GONG Mao-Chu*

2009, 30(8):  1625-1630. 

Asbtract ( )   PDF (647KB) ( )  

References | Related Articles | Metrics

Ce_0.1+xTi_0.5-xAl_0.2Y_0.1La_0.1O_1.8(0≤x≤0.4) mixed oxides were prepared by co-precipitation method and characterized by means of X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), nitrogen adsorption(BET), oxygen storage capacity(OSC), H₂-temperature programmed reduction(H₂-TPR) and NH₃-temperature programmed desorption(NH₃-TPD). The results of XRD revealed that there was only one single cubic phase in Ce_0.1+xTi_0.5-xAl_0.2Y_0.1La_0.1O_1.8 system when x value increased from 0.2 to 0.4. The results of XPS showed that the ratio of superficial Ce⁴⁺/Ce³⁺ is maximal when x is 0.2. With the increase of Ce/Ti ratio, OSC is increased to a maximum value, and then gradually decreased. When x value is 0.2, the OSC reaches to 660 μmol/g, and the reduction temperature of Ce⁴⁺ is the lowest according to the H₂-TPR test(616 ℃). In this paper, a series of Pt/Ce_0.1+xTi_0.5-xAl_0.2Y_0.1La_0.1O_1.8 three-way catalysts were prepared and the catalytic activities of catalysts were investigated. The results revealed that Pt/Ce_0.3Ti_0.3Al_0.2Y_0.1La_0.1O_1.8 exhibits excellent low-temperature catalytic activity. The light-off temperature of C₃H₈, CO and NO over Pt/Ce_0.3Ti_0.3Al_0.2Y_0.1La_0.1O_1.8 is 236, 147 and 228 ℃, respectively.

Studies on Phase Equilibrium of Tertbutanol in Supercritical CO₂

WANG Lin, LI Ru-Lin, SUN Lin-Tao , CHEN Kai-Xun*

2009, 30(8):  1631-1635. 

Asbtract ( )   PDF (461KB) ( )  

References | Related Articles | Metrics

Vapor-liquid phase equilibrium data of tertbutanol in the SC-CO₂ from 323.2 K to 353.2 K were determined by constant-volume visual method. The phase equilibrium model was established by Peng-Robinson equation of state and Vander Waals-2 mixed regulation. Model parameters were obtained by nonlinear least square method optimization calculation. Furthermore, the correlation equations of model parameters vs. temperature were obtained: k₁₂=-199.2066+1.8136T-0.00548T²+5.50×10^-6T³, n₁₂=-384.5626+3.4960T-0.01056T²+1.06×10^-5T³. Critical properties of critical pressure, critical temperature, critical molar volume and critical density were deduced. The results showed that critical temperature, critical pressure and critical compressibility factor of CO₂-tertbutanol system would decrease with the increasement of critical CO₂ content.

Homology Modeling and Evolution Trace Analysis of Human Adenovirus Type 3 Hexon

YUAN Xiao-Hui, QU Zhang-Yi*, WU Xiao-Min, WANG Ying-Chen, WEI Feng-Xiang, ......

2009, 30(8):  1636-1640. 

Asbtract ( )   PDF (366KB) ( )  

References | Related Articles | Metrics

The human adenovirus(HAdV) can cause a broad spectrum of human infective diseases. The major coat protein of HAdV is hexon which processes a mass of neutralizing epitopes. The complete amino acid sequence of hexon was directly obtained by sequencing hexon PCR product of HAdV type 3 which was isolated in local hospital. Homology modeling was utilized to construct a three-dimensional(3D) hexon model, and it was subsequently refined by molecular mechanics(MM) and molecular dynamics(MD) simulations. The neutralizing epitopes were analyzed by evolutionary trace(ET) approach including multiple sequence alignment(MSA), sites conservatism calculation and 3D mapping of conservatism. It was found that the sites conservatism was lower closer to the tower region and the major variable sites of hexon were located in the tower region. These results indicated that the type-specific neutralizing epitopes of hexon lied in the surface loop regions of hexon tower.

Molecular Simulations Study on the Residue 13 in Exendin-4

WANG Song, ZHAO Xi, ZHENG Qing-Chuan*, HUANG Xu-Ri, SUN Chia-Chung

2009, 30(8):  1641-1644. 

Asbtract ( )   PDF (243KB) ( )  

References | Related Articles | Metrics

Exendin-4 as a peptide of 39 amino acid residues is an important agonist for native GLP-1 receptor and its 13th residue is crucial for biological activity according to the mutational experiments(Tyr13→Gln13). In the present work, the role of the 13th residue in enhancing activity was investigated by means of the mole-cular dynamics simulations, molecular docking and electrostatic calculation. The results suggest that the mutated Exendin-4(Tyr13→Gln13) can strength the interactions with the receptor by adjusting itself local flexibi-lity, further increase the biological activity for GLP-1 receptor.

Raman Spectroscopic Study of Oxygen Vacancies in Ce_1-xTb_xO_2-δ Mixed Oxides

GUO Ming, PU Zhi-Ying, BI Qing-Yuan, LU Ji-Qing, LUO Meng-Fei*

2009, 30(8):  1645-1650. 

Asbtract ( )   PDF (637KB) ( )  

References | Related Articles | Metrics

A series of Ce_1-xTb_xO_2-δ mixed oxides were prepared by a sol-gel method. In situ Raman spectroscopy combined with X-ray diffraction(XRD), H₂-temperature programmed reduction(H₂-TPR) and O₂-temperature programmed desorption(O₂-TPD) were used to analyze oxygen vacancies in the mixed oxides under different atmospheres(O₂, He, and H₂) with 514 and 785 nm excitation laser lines and the blue shift of the F_2g vibration mode of CeO₂. The results show that increasing Tb content in the sample result in the blue shift of F_2g vibration mode of CeO₂ because of dominant effect of the shrinking of the crystal. Furthermore, the difference in the changing trend of oxygen vacancies is due to the different Raman excitation laser lines. 514 nm excitation laser line can provide the surface information, while 785 nm excitation laser line can get the whole information of the sample. The A₅₈₇/A₄₆₅ ratio reflecting the oxygen vacancies shows an inflexion under He and H₂ atmospheres could be explained by the change in microstructure of the sample along with the release of O₂ during the heating process.

Synthesis and Gelation Behavior of a Fluorescent Active Low-Molecular Mass Organic Gelator Based on Cholesterol

YAN Ni, YANG Mei-Ni, LIU Kai-Qiang, FANG Yu*

2009, 30(8):  1651-1657. 

Asbtract ( )   PDF (797KB) ( )  

References | Related Articles | Metrics

A new 7-nitrobenzo-2-oxa-1,3-diazol-4-yl-appended cholesterol derivative(NBD-C) was synthesized and characterized, and its gelation ability was evaluated in 30 solvents. It was found that NBD-C is an efficient gelator of acetonitrile, and the gel system possesses very smart thixotropic property. Scanning electron microscopy(SEM) observation showed that the gelator aggregated into different supramolecular structures in different solvents. FTIR, ¹H NMR and fluorescence spectroscopy studies revealed that in addition to the van der Waals interaction between the cholesterol units of the gelator molecules, intermolecular hydrogen-bonding also plays crucial rule for the spontaneous formation of the gel networks.

Phase Transition Capability of the Binary System Capric Acid-Myristic Acid

GAO Gui-Bo, QIAN Chun-Xiang*

2009, 30(8):  1658-1661. 

Asbtract ( )   PDF (299KB) ( )  

References | Related Articles | Metrics

Cooling-curves of different composition after ultrasonic blend were measured with the guide of theory forecast results of the binary system of capric acid and myristic acid. The experiment phase diagram was protracted, eutectic temperature and composition range were discovered of the binary system. Phase change properties of eutectic composition were tested with DSC, the change of the wave shape of eutectic composition after 300 thermocycling was tested with IR. The experiment results showed that the eutectic composition range in the binary system CA-MA is (76%—82%)CA+(24%—18%)MA, the eutectic temperature is 294.45 K, the maximal supercooling degree is 274.75 K and the delaminating phenomena not appeared in the phase change process. The test results showed the phase transition enthalpy is 149.02 J/g, the onset temperature of phase change is 292.80 K and thermal stability is fine of 78%CA+22%MA composition.

Preparation and Characterization of a Novel Thermoplastic Starch Using Dimethyl Sulfoxide as the Plasticizer

ZHANG Kun-Yu, RAN Xiang-Hai, WU Hang, YAO Bin, HAN Chang-Yu, ......

2009, 30(8):  1662-1667. 

Asbtract ( )   PDF (631KB) ( )  

References | Related Articles | Metrics

A novel thermoplastic starch was prepared by melting processing method using dimethyl sulfoxide(DMSO) as a plasticizer. The effect of the plasticizer was investigated by a combination of FTIR, XRD, SEM, DMA and tensile testing techniques, and was compared with the more conventional plasticizers, glycerol and glycerol/water. FTIR analysis show that DMSO act as a hydrogen bond acceptor and can form stable hydrogen bonds with starch. XRD and SEM results indicate that the crystalline of starch is destructed and the starch granules transferred to a continuous amorphous phase. It was found that the DMSO could more effectively restrain the retrogradation than the plasticizers, glycerol and glycerol/water, due to the stronger hydrogen bonds. The mechanical analysis showed that the effect of the DMSO was better than glycerol and glycerol/water.

Synthesis and Application of RAFT Agent p-Xylylene Di(N-carbazylcarbodithioate)

ZHANG Jian-Hua, GUO Rui-Wei*, LI Bin, DONG An-Jie

2009, 30(8):  1668-1673. 

Asbtract ( )   PDF (532KB) ( )  

References | Related Articles | Metrics

A double-functional reversible addition fragmentation chain transfer radical polymerization(RAFT) agent p-xylylene di(N-carbazylcarbodithioate)(PXCBD) was synthesized with carbazole and 1,4-bis(chloro-methyl)benzene as main material. With PXCBD as a chain transfer agent, the well-defined triblock and pen-tablock polymers were controllably synthesized by RAFT polymerization of styrene, methyl acrylate and N,N-dibutylacrylamide. The fluorescence characteristic of PXCBD and polymers prepared by PXCBD were studied. The results show that PXCBD as RAFT agent possesses good control ability and can be used to synthesize fluorescence-labelled polymers with well-defined structure.

Synthesis and Drug Release Behavior of Thermosensitive Dendrimer Derivatives

WANG Wei, ZHANG Jun, SU Qu, WANG Zheng*

2009, 30(8):  1674-1679. 

Asbtract ( )   PDF (504KB) ( )  

References | Related Articles | Metrics

The thermosensitve polymer was grafted to the polyamidoamine(PAMAM) dendrimer using EDC•HCl. The structure of the dendrimer derivative was characterized by FTIR and ¹H NMR and the mole-cular weight was determined by GPC and ¹H NMR, which indicates that the grafted polymer was synthesized successfully. The thermosensitve properties determined by UV-Vis photometer showed that the LCST was changed in different medium. Using indomethacin as a model drug, the behavior of the temperature controlled drug release from this novel polymer derivative have been studied. The results show that the rate of the drug release can be effectively controlled by the surrounding temperature, and the solubility of the drug is also increased. The new drug carrier is desirable to make a great effect in the drug delivery system.

Preparation of Oligo(p-phenylkene vinylene)/MCM-41 Nanocomposite Material

ZHAO Xian-Liang, LIN Hang, TANG Jun*, LIU Jun-Song*

2009, 30(8):  1680-1682. 

Asbtract ( )   PDF (289KB) ( )  

References | Related Articles | Metrics

Preparation of an oligo(p-phenylkene vinylene)(OPPV) inside the channels of the mesoporous silica MCM-41 was described. Presence of OPPV was observed by N₂ adsorption istherms. Fluorescence spectra results show that the luminescent peak of the OPPV in the composites undergo a blue shift about 80 nm and its emission intensity is enhanced compared with that of OPPV in solid state, and the photostability is much better, all of which make such composites of more practical significance.

Polyetherimide Microporous Films Prepared by Water-assisted Method

ZHAO Yan, ZHANG Shu-Ling, LIU Bai-Jun, ZHANG Chun-Feng, HU Yong-Cai, ......

2009, 30(8):  1683-1686. 

Asbtract ( )   PDF (613KB) ( )  

References | Related Articles | Metrics

Polymeric microporous films were successfully prepared from polyetherimide/chloroform solutions by water assisted method. The influence of key operating conditions on the morphology of pores, such as relative humidity and polymer concentration, were studied. By optimizing the humidity and polymer concentration, the regular and uniform microporous films based on polyetherimide(Ultem 1010) could be obtained. Moreover, the thermal stability, corrosion resistence and mechanical properties of the microporous films were excellent.