Chemical Research in Chinese Universities

Synthesis, Structure Characterization and Biological Activity of Layered Vanadium Oxides [NH₃(CH₂)₂NH(CH₂)₂NH₃][V₆O₁₄]

FU Ping-ping, WANG Xin-long, WANG En-bo, QIN Chao, XU Lin

2005, 21(5): 509-511.

Abstract ( )

PDF (251KB) ( )

References | Related Articles | Metrics

A new layered vanadium oxide [NH₃(CH₂)₂NH(CH₂)₂NH₃][V₆O₁₄](compound 1) was synthesized and characterized by elemental analysis, IR spectrometry and single crystal X ray diffraction. The compound crystallizes in a monoclinic space group P2(1)/n with a=1.0254(2) nm, b=0.6739(2) nm, c=1.2400(2) nm, β=93.88(3)°, V=0.8549(3) nm³, Z=2, R₁=0.0366, wR₂=0.1038. Compound 1 consists of two-dimensional mixed-valence vanadium oxide layers parallelling to the bc plane. The anti-tumor activity of the compound was estimated in three human tumor cell lines in vitro.

Synthesis of Nonionic Oligomeric Manganese(Ⅱ) Complexes and Investigation of Their Toxicity and T₁-Relaxation Enhancement

YU Kai-chao, LI Ying-xia, ZHOU Jin-lan, DING Shang-wu, YE Chao-hui

2005, 21(5): 512-516.

Abstract ( )

PDF (307KB) ( )

References | Related Articles | Metrics

Six nonionic oligomeric manganese(Ⅱ) complexes with oligomeric phosphate-polyglycol-EDTA ester ligands were synthesized and characterized. The longitudinal relaxivities of these complexes were measured. One of these complexes, which showed the highest relaxivity, was chosen to be used in the acute toxicity test and the T₁-weighted imaging experiment. It has been found that compared to Gd-DTPA, this nonionic oligomeric Mn(Ⅱ) complex exhibits no acute toxicity, generates highly enhanced MRI signals and increases the intention time in the rat liver tissue.

Electrochemical Detection of Clenbuterol in Pig Liver at Pyrrole-DNA Modified Boron-doped Diamond Electrode

WU Jing, LI Xiao-li, WU Xu-mei, HUAN Shuang-yan, SHEN Guo-li, YU Ru-qin

2005, 21(5): 517-521.

Abstract ( )

PDF (263KB) ( )

References | Related Articles | Metrics

The direct detection of clenbuterol(CL) in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond(BDD) electrode is reported. The pyrrole-DNA modified BDD electrode has a strong electrocatalytic effect on the redox reaction of CL. One oxidization and two reduction peaks of CL appear at 340.2, 299.8 and 166.6 mV(versus SCE), respectively. The pyrrole polymer alone cannot electrocatalyze the above reaction at a BDD electrode; the electrocatalytic effect of a BDD electrode modified with DNA membrane is unsufficient for the analytical detection of CL; the replacement of boron-doped diamond by glass carbon makes the electrocatalytic reaction impossible; the redox process is pH dependent. The influences of various experimental parameters on the pyrrole-DNA modified BDD electrode were investigated. A sensitive cyclic voltammetric response for CL was obtained in a linear range from 3.4×10^-6 to 5×10^-4 mol/L with a detection limit of 8.5×10^-7 mol/L. A mean recovery of 102.7% of CL in the pig liver sample solution and a reproducibility of 3.2% were obtained.

Kinetic Adsorption of Cd onto Nanometer Al₂O₃/Carbon Fibre

LI Yu, WANG Yue, HAN Wei, LI Su-wen, ZHAO Hui, ZHU Chang-yun, WANG Heng

2005, 21(5): 522-524.

Abstract ( )

PDF (296KB) ( )

References | Related Articles | Metrics

A new nanometer material, nano-Al₂O₃ with carbon fibre as the carrier, was employed for the removal of Cd with low concentrations from polluted water. The characterization of the material was carried out by means of SEM and TEM. Batch adsorption and elution experiments were carried out to determine the adsorption properties of Cd on the new adsorbent. The classical Thomas model was applied to estimating the equilibrium coefficients of Cd adsorption and the saturated adsorption ability. The results show that the Thomas model is fit for describing the kinetic adsorption process, and the maximum adsorption capacity of the nanometer Al₂O₃/carbon is 69.29 mg/g. The resulting information also indicates that the desorption of Cd eluted with de-ionized water at a rate of 9.8 mL/min can be neglected. With the advantage of a high adsorption capacity for removing low concentration Cd, the Al₂O₃/carbon fibre possesses the potentiality to be an effective adsorbent for the removal of Cd from polluted water.

Conformation Analysis and Comparison of Epristeride(17β-N-t-Butylcarboxamide-androst-3,5-diene-3-carboxylic Acid) and Its Analogs

YAO Li-xin

2005, 21(5): 525-527.

Abstract ( )

PDF (268KB) ( )

References | Related Articles | Metrics

Conformations of Epristeride(17-β-N-t-butylcarboxamide-androst-3,5-diene-3-carboxylic acid) and its analogs were analyzed with the random search method and compared by means of the methods for steroid conformers, Connolly surfaces, dihedral angles, and molecular accessibility probes with protons, hydroxyl and methyl groups contained simultaneously. Analog d is different from others, which is in accordance with the preliminary clinical trial results under double blind conditions.

Structure and Biological Activities of 2-(1,3-Dithiolan-2-ylidene)-1-phenyl-2-(1,2,4-triazol-1-yl)ethanone

XU Liang-zhong, LI Wei-hua, YU Guan-ping, QIN Yong-qi, YANG Shuang-hua, HOU Bao-rong

2005, 21(5): 528-530.

Abstract ( )

PDF (1400KB) ( )

References | Related Articles | Metrics

In order to find leading compounds with an excellent fungicidal activity, the title compound 2-(1,3-dithiolan-2-yl-idene)-1-phenyl-2-(1,2,4-triazol-1-yl)ethanone was synthesized according to the biological isosterism and its stru-cture was confirmed by means of IR, MS, ¹H NMR and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound exhibits some biological activities.

Terpenoid Glucosides from Aster Smithianus

GUO Shou-jun, ZHAO Xin-hua, YANG Yong-li, CHENG Dong-liang

2005, 21(5): 531-535.

Abstract ( )

PDF (270KB) ( )

References | Related Articles | Metrics

A diterpenoid trisaccharide, smithoside A, and a saponin, smithoside B, as well as six known compounds, apigenin, apigenin-7-O-glucoside, daucosterol, shanzhiside methyl ester, 8-acetylshanzhiside methyl ester and acteoside, were isolated from Aster smithianus. On the basis of spectral evidence and chemical analytical results, smithosides A and B were identified as pimar-15(16)-β-ene-8β,11α-diol-3β-O-β-D-glucopyranosyl(1^→3)-[β-glucopyranosyl(1^→2)]-β-D-glucopyranoside and 2β,3β,16β,21β,23-pentahydroxy-12-ene-28 oleanoic acid lactone-3-O-β-D-glucopyranosyl(1^→3)-β-D-glucopyranoside, respectively.

Synthesis of Novel Derivatives of (R)-Cysteine and Their Application in Asymmetric Reduction of Prochiral Ketones

WANG Hui, PEI Wei-wei, YE Wei-ping

2005, 21(5): 536-539.

Abstract ( )

PDF (510KB) ( )

References | Related Articles | Metrics

Novel chiral β-amino alcohols containing sulfide or sulfonyl groups were synthesized from (R)-cysteine. Their chiral induction in the asymmetric borane reduction of prochiral ketones was investigated. Optically active secondary alcohols with moderate or high e.e. values were obtained, and the causes of different enantioselectivities between these two sulfur-containing chiral β-amino alcohols were researched.

Syntheses and Antibacterial Activities of Novel Erythromycin O-Alkylamidoximes

ZHANG Zhan-tao, WU Cai-ling, ZHAO Yan-fang, CHENG Mao-sheng, GONG Ping

2005, 21(5): 540-544.

Abstract ( )

PDF (255KB) ( )

References | Related Articles | Metrics

Nine novel erythromycin O-alkylamidoxime derivatives were prepared in excellent yields via the condensation of different O-alkylhydroxylamines with erythromycin imino ether. The structures of all the compounds prepared were confirmed by ¹H NMR, ¹³C NMR, IR and MS, and their in vtiro antibacterial activities were tested. Among the compounds, two of them showed good antibacterial activities.

Synthesis and Characterization of N-(2,3,4,6-Tetra-O-acetyl-β-D-glucopyranosyl)-thiocarbamic-4-hydroxy-benzoyl Hydrazine Dihydrate

ZHANG Shu-sheng, YE Su-juan, LI Xue-mei, GU Shan-shan, LIU Qing

2005, 21(5): 545-548.

Abstract ( )

PDF (229KB) ( )

References | Related Articles | Metrics

A new complex of N-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-thiocarbamic 4-hydroxy-benzoyl hydrazine dihydrate, C₂₂H₂₇N₃O₁₀S·2H₂O, was synthesized and its structure was determined by X-ray crystallography and TG/DTG methods. The compound belongs to the orthorhombic system, which crystallizes in space group P2₁2₁2₁, with a=1.0275(3), b=1.3419(4), c=2.0234(6), V=2.7899(16) nm³, and Z=4. The hexopyranosyl ring adopts a ^{4C₁ conformation. All the substituents are at equatorial positions. The molecules are linked into a three-dimensional framework via intermolecular interactions. Atoms O5 and O9 show positional disorders.}

Isolation and Characterization of Two New Compounds from Lysimachia Davurica

TIAN Jing-kui, ZOU Zhong-mei, XU Li-zhen, YANG Shi-lin

2005, 21(5): 549-551.

Abstract ( )

PDF (411KB) ( )

References | Related Articles | Metrics

Two new saponins named davuricoside H and davuricoside K were isolated from the whole plant of Lysimachia davurica. The structures of davuricoside H and davuricoside K were determined by 1-D and 2-D NMR, MS techniques, and chemical methods to be 3β,16α,28-trihydroxy-olean-12-en-30-oic acid-3-O-β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranoside and 3β,16α,28-trihydroxy-olean-12-en-30-oic acid-3-O-{β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl}-30-O-β-D-glucopyranosyl-ester.

Gene Sequence, Soluble Expression and Homologous Comparison of a D-Hydantoinase from Pseudomonas putida YZ-26

SHI Ya-wei, ZHAO Li-xia, NIU Li-xi, FENG Xia, YUAN Jing-ming

2005, 21(5): 552-557.

Abstract ( )

PDF (401KB) ( )

References | Related Articles | Metrics

A 1440bp open-reading frame encoding D-hydantoinase from Pseudomonas putida YZ-26 was cloned and sequenced(GenBank AY387829). The DNA fragment was inserted into Nde and BamHI sites of vector pET-3a, yielding a recombinant plasmid, pET-HDT. After being transferred into the host strain, the artificial strain, pET-HDT/E.coli BL21 can express the D-hydantoinase as the soluble form in the Lura-Bertani medium without addition of any inducers. The activity of the enzyme toward substrate DL-hydantoin can reach 3000-4000 IU per cells from one-liter bacterial culture incubated at 30 ℃ for 10-12 h. By the comparison of amino acid sequence homology, hydrophobic residues analysis and secondary structure prediction, it was found that D-hydantoinase reported herein is quite similar to that from Pseudomonas putdia CCRC12857, and alike to that from Pseudomonas putdia DSM84 or other bacteria. A rapid and efficient purification procedure of the enzyme was performed by a three-step procedure: ammonium sulfate fractionation, phenyl Sepharose hydrophobic interaction chromatography and Sephacryl S-200 gel filtration. The molecular mass of the monomeric enzyme is 52042 Da as determined by MALDI-TOF mass spectrometry.

Purification and Characterization of Superoxide Dismutase(SOD) from Camellia Pollen

HE Xiao-hong, WU Min, LI Shan-yu, FAN Hao, CHU Yu-zhuo, LIU Lan-ying

2005, 21(5): 558-561.

Abstract ( )

PDF (305KB) ( )

References | Related Articles | Metrics

A superoxide dismutase(SOD) was purified to homogeneity from fresh camellia pollen by means of ammonium sulfate precipitation and column chromatography with DEAE-cellulose(DE52), Sephadex G-100 and phenyl sepharose^TM 6 Fast Flow columns. Its specific activity could reach to 4034 U/mg protein and it was determined to be Cu/Zn-SOD according to its different sensitivities to different inhibitors. The molecular weight of the SOD and its subunit were 69500 and 34700, respectively, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE), which implicates that the SOD in camellia pollen is a dimmer composed of two identical subunits. The iso-electric point of the enzyme was determined to be 4.1 by isoelectric focusing electrophoresis and the N-terminal amino acid was identified to be Gly by the DNS-Cl method. Its α-Helix was also calculated to be approximately 21.8% according to the circular dichroism(CD) spectra.

Chemical Modification of Tryptophan Residues in Superoxide Dismutase from Camellia Pollen and Its Fluorescence Spectrum

HE Xiao-hong, WU Min, LI Shan-yu, CHU Yu-zhuo, CHEN Jia, LIU Lan-ying

2005, 21(5): 562-565.

Abstract ( )

PDF (215KB) ( )

References | Related Articles | Metrics

The amino acid composition of the superoxide dismutase(SOD) from camellia pollen was measured and the tryptophan(Trp) residues were modified by using N-bromosuccinimide(NBS). The results show that there are 21 Trp residues in an SOD molecule and seven of which are located on the surface of the enzyme. By researching the fluorescence spectra of the native SOD and the modified SOD, we have found that the emission wavelength of Trp is at 335 nm and the fluorescence intensity will decrease when the enzyme is modified. The results also show that potassium iodide(KI) can significantly quench the fluorescence of the native SOD, but it has a less pronounced effect on the modified enzyme. Glycerin as a surface activation reagent can stabilize the fluorescence of the modified enzyme.

Synthesis of TP3 Fragment via One Pot Strategy and Its Immune Regulatory Activity

WANG Li-feng, CHEN Jie, SHAN Hui-jie, LI Wei

2005, 21(5): 566-568.

Abstract ( )

PDF (434KB) ( )

References | Related Articles | Metrics

We have modified the previously described one-pot peptide synthesis method. The modified method has been successfully applied to the synthesis of TP3. Furthermore, the immune regulatory activity of TP3 has been characterized. The results show that the modified one-pot method can be used to synthesize the biological active peptide with the advantages of low cost and high productivity. Moreover, TP3 has a higher immune regulatory activity than TP5.

Scattering Resonance States and Partial Potential Energy Surface of Reaction I+HI(v=0)^→IH(v′=0)+I

SUN Xiao-min, WANG Hua-yang, CAI Zheng-ting, FENG Da-cheng, BIAN Wen-sheng

2005, 21(5): 569-572.

Abstract ( )

PDF (237KB) ( )

References | Related Articles | Metrics

The partial potential energy surface of the I+HI^→IH+I reaction involving the translational and vibrational motions has been constructed at the QCISD(T)//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI- measured by Neumark^.

Catalytic Preparation of Methyl Formate from Methanol over Silver

YANG Zhi, LI Jing, YANG Xiang-guang, WU Yue

2005, 21(5): 573-576.

Abstract ( )

PDF (454KB) ( )

References | Related Articles | Metrics

A catalytic reaction over a silver catalyst performed in an unregarded temperature region(473-873 K) with a long catalytic lifetime for the production of methyl formate from methanol was provided as a potential preparing route. The optimal yield of methyl formate(ca. 14.8%) with a selectivity >90% was obtained at about 573 K. Because α-oxygen species and bulk oxygen species coexist in the unregarded temperature region, a synergistic process concerning α-oxygen species and bulk oxygen species was proved over O_α -rich and O_γ-rich samples.

Evaluation and Model of Performance of A Tubular Solid Oxide Fuel Cell

JIA Jun-xi, SHEN Sheng-qiang

2005, 21(5): 577-582.

Abstract ( )

PDF (322KB) ( )

References | Related Articles | Metrics

A simulation model was developed to analyze the steady state and transient operation of a tubular solid oxide fuel cell. The model covers both the electrochemical and the heat transfer models. The electrochemical model deals with the Nernst potential, ohmic polarization, activation polarization, and concentration polarization, while the heat transfer model concerns the heat transfer by conduction, convection and radiation. The numerical results show that the ohmic loss is the dominant one among the three polarizations in a cathode-supported solid oxide fuel cell and in the middle part of a solid oxide fuel cell the temperature is higher than those at both the ends. When the inlet temperature and the flow rates of the fuel and the oxidant are kept constantly, the temperature of the solid structure of the cell will increase due to the increase of power output of the cell from the initial state to the new one.

Effects of ZnO Buffer Layer Thickness on Properties of Mg_xZn_1-xO Thin Films Deposited by MOCVD

DONG Xin, LIU Da-li, DU Guo-tong, ZHANG Yuan-tao, ZHU Hui-chao, YAN Xiao-long, GAO Zhong-min

2005, 21(5): 583-586.

Abstract ( )

PDF (417KB) ( )

References | Related Articles | Metrics

High-quality Mg_xZn_1-xO thin films were grown on sapphire(0001) substrates with a ZnO buffer layer of different thicknesses by means of metal-organic chemical vapor deposition. Diethyl zinc, bis-cyclopentadienyl-Mg and oxygen were used as the precursor materials. The crystalline quality, surface morphologies and optical properties of the Mg_xZn_1-xO films were investigated by X-ray diffraction, atomic force microscopy and photoluminescence spectrometry. It was shown that the quality of the Mg_xZn_1-xO thin films depends on the thickness of the ZnO buffer layer and an Mg_xZn_1-xO thin film with a ZnO buffer layer whose thickness was 20 nm exhibited the best crystal-quality, optical properties and a flat and dense surface.

Late-model Ionic Clusters of KNO3 and Their Configurations

SHI Lei, YANG Zhi, LIU Zhi-qiang, LIU Shu-ying

2005, 21(5): 587-591.

Abstract ( )

PDF (890KB) ( )

References | Related Articles | Metrics

Late-model ionic clusters of KNO₃ were formed under the conditions of electrospray ionization. A series of peaks of the ionic clusters could be observed in the electrospray ionization mass spectra(ESIMS). The general formulae of the ionic clusters were deduced to be K⁺(KNO₃)_n and NO₃^-(KNO₃)_m. By referring to the crystal structure of KNO₃, the possible configurations of these new typical ionic clusters were speculated based on the calculated data by means of the Gaussian-94^x computer program.

Solution of the Poisson-Boltzmann Equation for a Cylindrical Particle with a Limited Length: Functional Theoretical Approach

WANG Zheng-wu, GU Ming-yan, ZHANG Ge-xin, YI Xi-zhang

2005, 21(5): 592-596.

Abstract ( )

PDF (259KB) ( )

Related Articles | Metrics

With the help of the method of separation of variables and the Debye-Hüchel approximation, the Poisson-Boltzmann equation that describes the distribution of the potential in the electrical double layer of a cylindrical particle with a limited length has been firstly solved under a very low potential condition. Then with the help of the functional analysis theory this equation has been further analytically solved under general potential conditions and consequently, the corresponding surface charge densities have been obtained. Both the potential and the surface charge densities coincide with those results obtained from the Debye-Hüchel approximation when the very low potential of zeΨ?kT is introduced.

Electrocatalytic Activity of Pt/C Electrodes for Ethanol Oxidation in Vapor Phase

LIANG Hong, YE Dai-qi, LIN Wei-ming

2005, 21(5): 597-600.

Abstract ( )

PDF (230KB) ( )

References | Related Articles | Metrics

High performance platinized-carbon electrodes have been developed for the electrocatalytic oxidation of ethanol to acetaldehyde in electrogenerative processes. A load current density of the electrode can be achieved as high as 600 mA per square centimeter for oxygen reducing in 3 mol/L sulfuric acid with a good stability. With these electrodes and sulfuric acid as an electrolyte in fuel cells, ethanol vapor carried by nitrogen gas can be oxidized selectively to acetaldehyde. Selectivity of acetaldehyde depends on the potential of the cell and the feed rate of ethanol vapor and it can be more than 80% under optimized conditions. The initial product of ethanol oxidized on a platinized-carbon electrode is acetaldehyde and the ethanol oxidation mechanism is discussed.

Synthesis, Characterization of Mesoporous Al-Mg Composite Oxide and Catalytic Performance for Oxyethylation of Fatty Alcohol

SONG Wei-ming, DENG Qi-gang, ZHOU De-rui, ZHAO De-feng

2005, 21(5): 601-605.

Abstract ( )

References | Related Articles | Metrics

A mesoporous Al-Mg composite oxide with a hexagonal structure was synthesized with aluminium nitrate and magnesium nitrate as the reagents and sodium dodecyl sulfate(SDS) as the template in the presence of ethylenediamine. The XRD, nitrogen adsorption-desorption and TEM studies indicate that the composite has a hexagonal framework structure and an average pore diameter of 2.6 nm. The TG/DTA spectra indicate that the decomposition and the removal of the occluded surfactant of the sample take place in a range of 230-550 ℃. The mesoporous Al-Mg composite oxide exhibites a highly catalytic activity for the oxyethylation of fatty alcohols. Narrow-range distributed ethoxylates are formed in the presence of the mesoporous Al-Mg composite oxide catalyst. The distribution selectivity coefficient(C_s) is 24 when the mesoporous Al-Mg composite oxide was used as a catalyst for the oxyethylation of octanol and the average adduct degree of ethoxylates is 6.4.

A New Method to Study the Sol-gel Transition Process of Organic/Inorganic Hybrid Materials

GUO Bin, GAO Jian-gang, CHEN Da-zhu, LIU Jian-ping, HE Ping-sheng, ZHANG Qi-jin

2005, 21(5): 606-610.

Abstract ( )

References | Related Articles | Metrics

The sol-gel transition process of PMMA/SiO₂ hybrid materials was first studied by means of the dynamic torsional vibration method. The different stages of the transition can be described by the change of torque. The temperature-dependent measurement of the gel time(t_g) gives the possibility to determine the apparent activation energy(E_a) of this transition according to Flory′s gelation theory. The non-equilibrium thermodynamic fluctuation theory was used to predict the transition behavior. The isothermal transition experiments on hybrid sols with different TEOS(tetraethyl orthosilicate) contents were carried out. The results show that the _a of a hybrid sol is higher than that of a non- hybrid sol of a TEOS-water-ethanol system. The increasing of TEOS content in a hybrid sol has no obvious effect on the E_a value, but it can enhance the sol-gel reaction rate.

Morphology and Compatibility of Compatibilized Polyethersulfone and Polycarbonate Blends

SUN Xiao-bo, JIANG Dong, WU Wei-chun, JIANG Zhen-hua

2005, 21(5): 611-614.

Abstract ( )

References | Related Articles | Metrics

A PES-PC(polyethersulfone-polycarbonate) multi block random copolymer was synthesized with two oligomers, polyethersulfone and polycarbonate. The effects of the copolymer, as a compatibilizer, on the morphology and compatibility of the PES-PC blends were investigated. It was found that the addition of this copolymer to the PES-PC blends could improve their compatibility.

Synthesis of Poly(styrene-b-isoprene-b-styrene) via Nitroxide-mediated Radical Polymerization by a Novel Alkoxyamine

GAO Long-cheng, PAN Qi-wei, FAN Xing-he, CHEN Xiao-fang, WAN Xin-hua, ZHOU Qi-feng

2005, 21(5): 615-618.

Abstract ( )

References | Related Articles | Metrics

Bifunctional alkoxyamine bis-TIPNO derived from 2,2,5-trimethyl-4-phenyl-3-azahexane-3-oxyl(TIPNO) and α, ω-alkyl bromide by atom transfer radical addition(ATRA) was employed as "biradical initiator" for nitroxide-mediated radical polymerization(NMRP) of isoprene and styrene. The kinetics study for the polymerization of styrene at different time showed living features. The poly(styrene-b-isoprene-b-styrene)(SIS) copolymers have two glass transition temperatures, indicating the immiscibility of the corresponding blocks.