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25 July 2012, Volume 28 Issue 4

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Cover and Content of Chemical Research in Chinese Universities Vol.28 No.4(2012)

2012, 28(4):  1. 

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Articles

Nano/Micro HKUST-1 Fabricated by Coordination Modulation Method at Room Temperature

NA Li-yan, HUA Rui-nian, NING Gui-ling, OU Xiao-xia

2012, 28(4):  555-558. 

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A simple and fast route for the synthesis of metal-organic framework(MOF) particles was presented. Cu₃(BTC)₂(HKUST-1, BTC=1,3,5-benzenetricarboxylate), one of the most well-known MOFs, was synthesized at room temperature via coordination modulation method. By adding different modulators(monocarboxylic acids) into the reaction system, the morphologies of HKUST-1 crystals were tuned from nano spheres to micro octahedrons at room temperature without any complex equipment. X-Ray diffractions and gas sorption measurements revealed highly crystalline particles with large Brunauer-Emmett-Teller(BET) surface areas(1116-1273 m²/g) and total pore volumes(0.62-0.73 cm³/g). The significantly small particle sizes and high capacity of gas sorption are considered advantageous for envisaged application in practical industrial process.



Synthesis of Mesostructured Iron Oxides with Potential As(V) Adsorption Application

LI Fei-hu, FU Xiao-ru, HUANG Jie, ZHAI Jian-ping

2012, 28(4):  559-562. 

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Mesostructured iron oxides(MIOs) were nanocasted from a plugged hexagonal templated silica(PHTS) with a Brunauer-Emmett-Teller(BET) surface area of 694 m²/g. Results of X-ray diffraction(XRD), transmission electron microscopy(TEM) and N₂ adsorption-desorption suggest that the nanocasted MIOs are synthetic hematite(α-Fe₂O₃) with a wormhole-like mesoporous network. As(V) adsorption test shows that the selected MIO—MIO-500(calcinated at 500℃) with a BET surface area of 82 m²/g has a maximum adsorption capacity of 5.39 mg/g for As(V), which is 2.5 times as large as that of natural hematite adsorbent. The study suggests that MIOs could be potentially used as the adsorbent of As(V) in wastewater.



Synthesis, Characterization and Magnetic Properties of a New Manganese(II) Phosphite

ZHANG Hua, WANG Li-ping, SHI Su-hua, HUANG Liang-liang, WANG Li

2012, 28(4):  563-566. 

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A new manganese(II) phosphite, Mn₂F₂(HPO₃)(1), was synthesized with tetraethylene pentamine as structure directing agent under hydrothermal conditions. The as-synthesized product was characterized by single crystal X-ray diffraction, powder X-ray diffraction, infrared(IR), UV-Vis spectrum, thermogravimetric analysis(TGA), inductive coupled plasma-atomic emission spectroscopy(ICP-AES), elemental analyses and magnetic susceptibility measurement. Single crystal X-ray diffraction analysis reveals that compound 1 crystallized in the orthorhombic space group Pnma, with a=0.75667(15) nm, b=1.0247(2) nm, c=0.55432(11) nm, V=0.42980(15) nm³, Z=4. The 3D compact framework of compound 1 was built up by the Mn₂O₆F₄ dimers and HPO₃ pseudo-pyramids. Compound 1, a new metal-rich manganese phosphite, shows a high thermal stability limit of 550℃. Magnetic measurement indicates that compound 1 exhibits the global antiferromagnetic interactions with a ferromagnetic transition at 28 K.



Shape Controlled Preparation, Characterization and Gas Sensitivities of Shuttle-like Cr-doped α-Fe₂O₃ Nanoparticles

Shufeng Si Zhengqiu Ming Guowen Xing Xi Yan

2012, 28(4):  567-571. 

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α-Fe2O3 nanoparticles doped with various mol% Cr3+ have been synthesized by a forced hydrolysis route, and were characterized by XRD, SEM, XPS and ICP techniques. The particles reserve shuttle-like shape in the presence of Cr3+ ions. The crystallite sizes of Fe2O3 become smaller with the increased Cr3+ concentration in solution. The responses of Cr doped α-Fe2O3 sensors were studied towards reducing gases such as ethanol, methanol, acetone, gasoline and n-hexane. Gas sensors based on these materials have higher sensitivities and rapid response/recovery time to alcohol than to hydrocarbon.



Novel Iridium Complex with Carbazol-2-yl-β-diketone Derivative: Low-energy Excitation and Red Electrophosphorescent Devices

LIU Jian, CHEN Hong-bin, LIU Sheng-gui

2012, 28(4):  572-576. 

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A novel iridium-complex, (BPPBI)₂Ir(2-TFDBC)[BPPBI=2-(biphenyl-4-yl)-1-phenyl-1H-benzo[d]imi- dazole, 2-TFDBC=1-(9-ethyl-9H-carbazol-2-yl)-4,4,4-trifluorobutane-1,3-dione], was synthesized, and its structure and component were confirmed by ¹H NMR and element analysis, respectively. UV-Vis absorption and photoluminescent(PL) spectra of (BPPBI)₂Ir(2-TFDBC) in dichloromethane were investigated. The Ir-complex exhibited a long wavelength excitation of 470 nm, i.e., low-energy excitation. So, it is a promising candidate for phosphorescent probe and PL material. (BPPBI)₂Ir(2-TFDBC)-based electroluminescent devices, ITO/MoO₃(10 nm)/NPB(80 nm)/ CBP:x(BPPBI)₂Ir(2-TFDBC)(20 nm)/TPBi(45 nm)/LiF/Al, were fabricated, where x(%) was of 4% or 8% doping concentration(mass fraction); ITO=indium tin oxides; NBP=N,N'-bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1'-biphenyl)- 4,4'-diamine, CBP=4,4'-bis(N-carbazolyl)-1,1'-biphenyl, TPBi=1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene. The devices showed a red emission of 620 nm. The maximum current efficiency and brightness were 1.7 cd/A and 4063 cd/m² for a device of 8%(mass fraction) doping level, respectively. The moderate luminous efficiency was due to the inadequate energy transfer from the host material to the guest material.



Solvothermal Preparation of Mn₃O₄ Nanoparticles and Effect of Temperature on Particle Size

SONG Rui, WANG Hong-jun, FENG Shou-hua

2012, 28(4):  577-580. 

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Hausmannite Mn₃O₄ nanoparticles were successfully prepared via a facile one-step solvothermal route with Mn(CH₃COO)₂·4H₂O as manganese source in the mixed solvent of acetone and water. Powder X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectrometry and transmission electron microscopy(TEM) were used to characterize Mn₃O₄ nanoparticles. It was found that the particle size could be tailored by varying the synthesis temperature. On the whole, the particle size becomes larger with the rising of solvothermal reaction temperature. But there is no linear relation between them. According to the different temperatures(60-140℃), the average particle size is from about 9 nm to 15 nm. Magnetic properties of Mn₃O₄ samples prepared at 60, 100 and 140℃ were studied via a superconducting quantum interference device(SQUID), respectively.



Temperature-controlled Hydrothermal Synthesis of Copper(I or II) Coordination Polymers via a Variety of Copper Coordination Modes

QU Xue-jian, WANG Shuang, ZHANG Dao-jun, JING Xue-min, ZHANG Li-rong, LI Guang-hua, HUO Qi-sheng, LIU Yun-ling

2012, 28(4):  581-584. 

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Two 1D coordination polymers Cu₂^I(C₆N₃H₄)₂(1) and Cu^II(C₆N₃H₄)₂·H₂O(2) based on benzotriazole(Bta) were hydrothermally synthesized by controlling the crystallization temperature. Single-crystal X-ray diffraction (XRD) analyses reveal that compound 1 is a 1D tubular structure constructed from two types of 1D chains {-Cu-N=N-N-}_n, where the Cu(I) ions adopt linear, triangular, and tetrahedral coordination modes to connect two types of Bta ligands via π-π interaction inside the tubular-like chain. For compound 2, the Cu(II) ions assume a quadrilateral coordination mode linking to the Bta ligands to give 1D straight chains, which stacks through π-π interactions to construct a 2D layer structure. Further characterizations including elemental analyses, infrared IR spectra, thermogravimetric(TG) analyses and luminescence properties have been done.



Synthesis, Crystal Structure, Thermal Decomposition and Sensitive Properties of a New Complex [Cu(IMI)₄](PA)₂

WANG Shi-wei, WU Bi-dong, YANG Li, ZHANG Tong-lai, ZHOU Zun-ning, ZHANG Jian-guo

2012, 28(4):  585-589. 

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A new coordination complex [Cu(IMI)₄](PA)₂ had been synthesized with imidazole(IMI) as ligands and picrate(PA^-) groups as outer anions, and characterized by Fourier transform infrared(FTIR) spectrum and elemental analysis. Its crystal structure was determined by single crystal X-ray diffraction(XRD) analysis. The crystallographic data show that the crystal belongs to monoclinic, C2/c space group, a=2.542(5) nm, b=0.91773(18) nm, c=1.3778(3) nm, β=107.854(3)° and Z=4. Furthermore, the central copper(II) ion is coordinated by four N atoms from four imi- dazole ligands. All the molecular units are linked into a zigzag pattern along a-axis by the hydrogen bonds, and extended to the distance regularly. Thermal decomposition mechanisms were determined based on differential scanning calorimetry(DSC) and thermogravimetry-differential thermogravimetry(TG-DTG) analysis, and kinetic parameters of the first exothermic process were studied using Kissinger’s and Ozawa-Doyle’s method, respectively. Sensitivity tests show that the title complex has low sensitivity to external stimulus, but it has a higher energy of combustion of 14.2 kJ/g due to which it may be used as the additives of energetic materials to improve the explosive performance.



Synthesis and Characterization of Manganese-copper Spinel Ferrite Powders

CAO Jun-gang, LI Jian-jun, DUAN Hai-feng, LIN Ying-jie

2012, 28(4):  590-593. 

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Magnetic Mn_1-xCu_xFe₂O₄(x=0.2, 0.5, 0.8 and 1.0) nanoparticles were synthesized by single citrate precursor method. The samples were characterized by powder X-ray diffraction, vibrating sample magnetometry and electron paramagnetic resonance(EPR). For samples with a low copper content(x<0.5), the copper ions have a tendency to occupy and substitute the Fe³⁺ at the tetrahedral(A) sites. For samples with a high copper content(x>0.5), most Cu²⁺ enter into the octahedral(B) sites. Transfer of Fe³⁺ from octahedral sites to tetrahedral sites leads to the decrease of the saturation magnetization. Maximum coercivity is observed for CuFe₂O₄ nanoparticles due to the strengthened magnetic anisotropy arisen from the Jahn-Teller effect of the octahedral copper ions. The dependence of magnetic properties of Mn_0.8Cu_0.2Fe₂O₄ nanoparticles on calcination temperature was investigated. The cation distribution in Mn_0.8Cu_0.2Fe₂O₄ is sensitive to the calcination temperature.



Metsulfuron-methyl Molecularly Imprinted Stir Bar Sorptive Extraction Coupled with High Performance Liquid Chromatography for Trace Sulfonylurea Herbicides Analysis in Complex Samples

XU Zhi-gang, DU Zhuo, LIAN Hai-xian, HU Yu-ling, LI Gong-ke

2012, 28(4):  594-599. 

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Metsulfuron-methyl molecularly imprinted polymer(MIP)-coated stir bar was prepared for sorptiveextraction of sulfonylurea herbicides in complex samples. The MIP-coating was about 21.3 祄 thickness with the relative standard deviation(RSD) of 4.4%(n=10). It was homogeneous and porous with good thermal stability and chemical stability. The extraction capability of the MIP-coating was 2.8 times over that of the non-imprinted polymer (NIP)-coating in hexane. The MIP-coating exhibited selective adsorption ability to the template and its analogues. The extraction conditions, including extraction solvent, desorption solvent, extraction time, desorption time and stirring speed, were optimized. A method for the determination of six sulfonylurea herbicides by MIP-coated stir bar sorptive extraction coupled with high performance liquid chromatography(HPLC) was developed. The linear range was 10-200 礸/L and the detection limits were within a range of 2.0-3.3 礸/L. It was also applied to the analysis of sulfonylurea herbicides in spiked river water, soil and rice samples.



Electrochemical Assay of Effects of Organophosphate Poisoning on Acetylcholinesterase from Pheretima via 2,6-Dimethyl-p-benzoquinone

WU Wu-ai, LI Jun, GAO Bao-ping, GUO Man-dong

2012, 28(4):  600-603. 

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Electroanalytical techniques could be a reliable and promising alternative to classical and sophisticated methods because of their simplicity(small and portable), easy use, the ability to deliver fast response with high sensitivity and selectivity. A square wave voltammetric method was developed for the assessment of organophosphorus(OPs) compound impact on acetylcholinesterase(AChE) of Pheretima with 2,6-dimethyl-p-benzoquinone(2,6- DMBQ) as a redox indicator. The substrate of acetylthiocholine is hydrolyzed by AChE and the produced thiocholine reacts with 2,6-DMBQ to give an obvious shift of electrochemical signal. The reduction peak of 2,6-DMBQ is located at around -0.18 V which is far away from the oxidation potential of possible interference components often present in biosample. The decreased rate of reduction current was related with the activity of AChE. The inhibition of parathion-methyl on AChE was assessed. The inhibiton rate of OPs on AChE activity increased quickly during the first 10 min inhibition, and after that the value of inhibition rate approached to be constant. AChE lost almost 29.3% of acti- vity after 10 min incubation with 1 mg/mL parathion-methyl and 67.5% of activity with 10 mg/mL parathion-methyl, while the activity that corresponds to 40 mg/mL parathion-methyl was nearly completely inhibited(94.9%). Compared to cyclic voltammetry and amperometry, Square wave voltammetry(SWV) method is a high sensitive electroanalysis with fast scan-rate(only several seconds for one signal value) which is useful to prevent the electrodes from possible fouling or passivation. This method can be employed to assess the inhibition of organophosphate on AChE and investigate OPs impact on environmental animals.



Determination of Biotin in Pharmaceutical Formulations by Potassium Permanganate-luminol-CdTe Nanoparticles Chemiluminescence System

TRAORE Zoumana Sékou, SU Xing-guang

2012, 28(4):  604-608. 

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A sensitive flow-injection chemiluminescence method was developed for the determination of biotin in the pharmaceutical formulations. The affinity between avidin and biotin was used to adsorb biotin on the polystyrene, with subsequent quantification of biotin based on its ability to enhance the chemiluminescence(CL) signal generated by the redox reaction of potassium permanganate-luminol-CdTe nanoparticles CL system. The investigations prove that apart from 3-aminophthalate, the CdTe quantum dots(QDs) play both catalytic and emitter roles. Under optimum conditions, the linear range for the determination of biotin was 0.01-25ng/mL with a detection limit of 7.3?10^-3 ng/mL(S/N=3). The relative standard deviation of 5 ng/L biotin was 2.06%(n=7). The proposed method was used to determine the biotin concentration in the pharmaceutical formulations and the recovery was between 96.4% and 104%. The proposed method is simple, convenient, rapid and sensitive.



6-(N,N-Dimethylamino)-2-naphthoylacryl Acid: a Highly Selective and Sensitive Fluorescent Sensor of Copper(II)

XIAO Xu-zhi, CHEN Peng, CHEN He-ru

2012, 28(4):  609-613. 

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A novel fluorescent probe, 6-(N,N-dimethylamino)-2-naphthoylacryl acid(ACADAN) was designed and synthesized as a fluorescent sensor for Cu²⁺ in aqueous media. Significant amplification of fluorescence signals without causing any discernible change of maximum fluorescence emission wavelength(λ_max) was observed upon the addition of Cu²⁺. Importantly, ACADAN is capable of recognizing Cu²⁺ selectively in aqueous media in the presence of various biologically relevant metal ions and the prevalent toxic metal ions in the environment with high sensitivity(detection limit was 0.1 μmol/L).



Luminescence Studies on Interaction of an Isoquinoline Alkaloid with Calf Thymus DNA in Aqueous Medium and on Solid Substrate

LI Jun-fen, SHI Wen-tao, HAN Xiu-ying, DONG Chuan, CHOI Martin M. F.

2012, 28(4):  614-619. 

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The interaction of calf thymus DNA(ctDNA) with berberine(Ber) was systematically investigated via UV-Vis, fluorescence and phosphorescence spectroscopies in aqueous solution and on solid substrate. The very weak fluorescence intensity of Ber at 525 nm in aqueous solution can be greatly enhanced by ctDNA. The UV-Vis spectrum shows that Ber could bind with DNA by intercalation. In addition, strong fluorescence of Ber alone could be observed on filter paper substrate and can be quenched by ctDNA effectively, and the increase of fluorescence polarization of Ber on the filter paper implies the intercalation binding. Ber emits phosphorescence at 619 nm in the presence of thallium(I) acetate. The lifetime of Ber increased from 38.4 ms to 43.4 ms with the increase of ctDNA. The increase of lifetime is possibly attributed to the increase of rigidity of Ber after its intercalating into the ctDNA base pairs. This explanation is also augmented by the anionic quenching results. Ber behaves as a typical intercalating agent into ctDNA.The intrinsic binding constant between Ber and ctDNA is (1.84?0.12)?10⁴ L/mol and n=0.16.



Central Composite Design for Optimized Extraction of Polysaccharides from Undaria pinnatifida

ZHU Tao, HEO Hyo-jung, ROW Kyung-ho

2012, 28(4):  620-623. 

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Response surface methodology was used to optimize the extraction conditions of polysaccharides from Undaria pinnatifida. The effects of three independent variables, extraction time, extraction temperature and ratio of water to raw material were investigated by a central composite design. The experimental data were fitted to a second-order polynomial equation via multiple regression analysis and also examined with the appropriate statistical methods. The adjusted coefficient of determination(R_ADj²) for the model was 0.9171. An optimum extraction yield of 30.78% was obtained when the extraction temperature was 95℃, extraction time was 4.5 h, and the ratio of water to raw material was 35(mL/g). Under these conditions, validation experiments were done and the mean extraction yield of polysaccharides was 30.79%, which was in good agreement with the predicted model value.



Binding of Pyrene to Different Molecular Weight Fractions of Dissolved Organic Matter: Effects of Chemical Composition and Steric Conformation

WU Ji-zhou, SUN Hong-wen, WANG Cui-ping, LI Yong-hong

2012, 28(4):  624-630. 

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The binding constant(K_DOM) of pyrene onto different molecular weight(M_w) fractions of a dissolved organic matter(DOM) extract from an estuarine sediment was measured via a fluorescence quenching method, and the possible binding mechanisms were discussed. The influence of water chemical parameters on pyrene binding was studied to elucidate the effects of DOM steric conformation. DOM fraction with larger M_w(>14000) showed a greater K_DOM(2.02×10⁵) than that with smaller M_w did, and the K_DOMs were 1.16×10⁵ and 1.13×10⁵ for the fractions with M_w of 1000-14000 and <1000, respectively. The K_DOMs of different M_w DOM fractions were correlated positively with the atomic ratio of C/H and absorbance at 280 nm; while a negative correlation existed between K_DOM and (O+C)/N (atomic ratio), and K_DOM and O-containing groups. These correlations indicate the positive influence of aromatic structure and the negative effect of polarity on DOM binding capacity. Infrared spectroscopy revealed that specific interactions existed between pyrene and the DOM fraction with larger M_W besides hydrophobic partition, i.e., NH-π interaction in DOM moiety(1000-14000) and π-π electron donor acceptor(EDA) forces in DOM moiety (>14000). K_DOM varied in a complex pattern with increasing cation concentration and pH, which could be explained by the change in DOM steric conformation. Formed aggregates favored the lipophilic partition of pyrene. However, the accessibility to some interior binding sites became low when the aggregate was too large, leading to a reduced K_DOM.



Synthesis of Bioactive Natural Polymethoxyflavones and Their Vinyl Ether Derivatives

CAI Shuang-lian, LIU Shuang, LIU Li, WANG Qiu-an

2012, 28(4):  631-636. 

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Bioactive natural polymethoxyflavones 1-6 and their vinyl ether derivatives 7-15 were synthesized by bromination, aromatic nucleophilic substitution, methylation, benzyl protection, Friedel-Crafts acetylation, aldol condensation, cyclization, DDQ dehydrogenation, regioselective demethylation, debenzylation and O-prenylation or O-farnesylation with resorcinol and appropriate substituted benzaldehydes as starting materials. Among them, compounds 7-15 are new compounds. Natural products 2-4 were firstly total synthesized. The syntheses of compounds 1, 5 and 6 were efficiently improved by the new synthetic routes. The structures of all synthetic compounds were confirmed by NMR, IR spectra and MS.



Preparation of Chiral 1,4-Phenylene-silicas via Chiral Low-molecular-weight Amphiphiles

XIAO Min, LIU Xiao-juan, HU Kai, WU Li-min, LI Yi, LI Bao-zong, YANG Yong-gang

2012, 28(4):  637-641. 

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Chiral organic-inorganic hybrid silicas can be prepared via the self-assemblies of chiral surfactants and gelators as templates. However, the relationship between the chirality of the hybrid silica and the structure of the surfactant/gelator has not been systemically studied. Herein, a series of chiral low-molecular-weight amphiphiles(LMWAs) derived from L-valine was synthesized. Their alkyl chains were n-butadecyl, n-hexadecyl and n-octadecyl, respectively. They can form viscous liquids in pure water, and physical gels in tetrahydrofuran, cyclohexanone, acetonitrile, acetone, chlorobenzene and nitrobenzene. Chiral 1,4-phenylene-silicas were prepared viathe self-assemblies of these LMWAs as templates. With increasing the alkyl chain length, the 1,4-phenylene-silicas changed from short mesoporous nanorods to long nanotubes. The circular dichroism spectra of the 1,4-phenylene-silicas indicated that the long nanotubes exhibit the strongest chirality.



Ga(ClO₄)₃-catalyzed Reaction of 1,2-Diamines and α-Bromoketones: Synthesis of 2-Substituted Quinoxalines

JI Yun-fei, CHEN Tang-ming, MAO Hai-feng, ZOU Jian-ping

2012, 28(4):  642-646. 

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Ga(ClO₄)₃-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxa- lines in good yields is described. The reaction proceeded via grinding process with 10%(molar fraction) catalyst under solvent-free conditions at room temperature. For unsymmetrical o-phenylenediamines bearing electron-with- drawing groups, regio-selective quinoxalines were obtained.



Novel Bis-β-diketone-type Ligand and Its Copper and Zinc Complexes for Two-photon Biological Imaging

ZHOU Shuang-sheng, XUE Xuan, WEI Dong, JIANG Bo, WANG Jia-feng, LU Cheng-hua

2012, 28(4):  647-651. 

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A curcumin derivative ligand, 1,7-bis(3-methoxyl-4-oxyethylacetate)phenyl-1,6-heptadiene-3,5-diketone (diethyl acetatecurcumin, abbreviated as HL), and its Cu(II) and Zn(II) complexes have been synthesized and characterized by elemental analyses, infrared(IR), ¹H NMR and molar conductivity. The experimental results show that the resulting complexes bear strong two-photon excited fluorescence(TPEF) in N,N-dimethyformamide solvent, which has been proven to be potentially useful for two-photon microscopy imaging in living cells. In addition, cytotoxicity tests show that the low-micromolar concentrations of metal-ligand complex(ML₂) did not cause significant reduction in cell viability over a period of, at least, 24 h and should be safe for further biological studies.



Synthesis of Polysubstituted 1,4-Dihydropyridines via Four-component Reactions of Arylamine, Acetylenedicarboxylate, Aromatic Aldehyde and Ethyl Acetoacetate

WU Ping, XIA Er-yan, SUN Jing, YAN Chao-guo

2012, 28(4):  652-655. 

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An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine, acetylenedicarboxylate, aromatic aldehyde and ethyl acetoacetate. The reaction mechanism involves the formation of β-enamino ester and its sequential Michael addition to arylidene acetoacetate.



Anti-tumor Activity of Biodegradable Polymer-paclitaxel Conjugated Micelle Against Mice U14 Cervical Cancers

CHEN Feng, DONG Dan, FU Yan, ZHENG Yong-hui, LIU Shi, CHANG Ming-xin, JING Xia-bin

2012, 28(4):  656-661. 

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Two kinds of paclitaxel(PTX) conjugate micelles, of which one contained 25%(mass fraction) PTX [M(PTX)] and the other contained 22.5%(mass fraction) of PTX and 1.4%(mass fraction) of folate(FA)[FA-M(PTX)], were prepared for cell apoptosis and anti-tumor activity evaluation on U14 cervical cancer mouse models in comparison with 0.9%(mass fraction) saline(control) and equivalent Taxol. Seven days after tail intravenous injection of the drugs, the mice were sacrificed to measure the tumor masses. The average tumor masses were 4.26, 2.89, 2.63, and 2.17 g for the control, Taxol, M(PTX) and FA-M(PTX) groups, respectively. The inhibition rates of tumor growth calculated for the three drug groups were 32%, 38% and 49%, respectively. Flow cytometry(FC) analysis and termi- nal deoxynucleotidyl transferase(TdT)-mediated deoxyuridine triphosphate(dUTP) nick end labeling(TUNEL) assay were conducted on the cancer tissues. The cell apoptosis rates based on the FC data and the TUNEL data were 20%, 31%, 37%, 42%, and 10%, 22%, 26%, 34%, respectively, both showing statistically significant differences(P<0.05) between three drug groups and the control group, and between the FA-M(PTX) group and the other two drug groups. In conclusion, the composite FA-M(PTX) micelles can be used for U14 cervical cancer treatment.



DNA Extraction from Formalin-fixed and Paraffin-embedded Tissues by Triton X-100 for Effective Amplification of EGFR Gene by Polymerase Chain Reaction

WANG Xiao-feng, DU Zhen-wu, WU Mei, ZHANG Yu-cheng, JIANG Yang, ZHANG Gui-zhen

2012, 28(4):  662-665. 

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For first-line non-small-cell lung cancer(NSCLC) therapy, detecting mutation status of the epidermal growth factor receptor(EGFR) geneconstitutes a prudent test to identify patients who are most likely to benefit from EGFR-tyrosine kinase inhibitor(TKI) therapy. Now, the material for detecting EGFR gene mutation status mainly comes from formalin-fixed and paraffin-embedded(FFPE) tissues. DNA extraction from FFPE and the amplification of EGFR gene by polymerase chain reaction(PCR) are two key steps for detecting EGFR gene mutation. We showed a simple method of DNA extraction from FFPE tissues for the effective amplification of EGFR gene. Extracting DNA from the FFPE tissues of NSCLC patients with 1% Triton X-100(pH=10.0) was performed by heating at 95℃ for 30 min. Meanwhile, a commercial kit was used to extract DNA from the same FFPE tissues of NSCLC patients for comparison. DNA extracted products were used as template for amplifying the exons 18, 19, 20 and 21 of EGFR by PCR for different amplified fragments. Results show that DNA fragment size extracted from FFPE tissues with 1% Triton X was about 250-500 base pairs(bp). However,DNA fragment size extracted from FFPE tissues via commercial kit was about from several hundreds to several thousands bp. The DNA yield extracted from FFPE tissues with 1% Triton X was larger than that via commercial kit. For about 500 bp fragment, four exons of EGFR could not be amplified more efficiently from extracted DNA with 1% Triton X than with commercial kit. However, for about 200 bp fragment. This simple and non-laborious protocol could successfully be used to extract DNA from FFPE tissue for the amplification of EGFR gene by PCR, further screening of EGFR gene mutation and facilitating the molecular analysis of a large number of FFPE tissues from NSCLC patients.



Molecular Cloning and Characterization of a New Cold-active Extradiol Dioxygenase from a Metagenomic Library Derived from Polychlorinated Biphenyl-contaminated Soil

REN He-jun, LU Yang, ZHOU Rui, DAI Chun-yan, WANG Yan, ZHANG Lan-ying

2012, 28(4):  666-671. 

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To find new extradiol dioxygenases(EDOs, EC 1.13.11.2), a metagenomics library was constructed from polychlorinated biphenyl-contaminated soil and was screened for some dioxygenase with aromatic ring cleavage activity. A novel EDO, designated as Bph­C_A, was identified and heterologously expressed in Escherichia coli. The deduced amino acid sequence of BphC­_A exhibited a homology of less than 60% with other known EDOs. Phylogenetic analysis of BphC­_A suggests that the protein is a novel member of the EDO family. The enzyme exhibits higher substrate affinity and catalytic efficiency toward 3-methylcatechol than toward 2,3-dihydroxybiphenyl or catechol, the preferred substrate of other known EDOs. The optimum activity of purified Bph­C_A occurred at pH=8.5 and 35℃, and Bph­C_A showed more than 40% of its initial activity at 5℃. The activity of purified Bph­C_A was significantly induced by Mn²⁺ and slightly reduced by Al³⁺, Cu²⁺ and Zn²⁺.



Delivering DNA into Plant Cell by Gene Carriers of ZnS Nanoparticles

FU Yu-qin, LI Lu-hua, WANG Pi-wu,, QU Jing, FU Yong-ping, WANG Hui, SUN Jing-ran, L? Chang-li

2012, 28(4):  672-676. 

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The development of nanotechnology provides a new method for genetic engineering. However, the nanoparticles as gene carriers have been mainly used in the mammalian cells so far. We observed that ZnS nanoparticles modified with positively charged poly-L-lysine(PLL) successfully delivered GUS-encoding plasmid DNA into tobacco cells by means of ultrasound-assisted method. Polymerase chain reaction(PCR) detection, Southern blot analysis and GUS histochemical staining were carried out for the regenerated plants. The stable genetic modified plants mediated by ZnS nanoparticles can be obtained. This article demonstrates the great potential of nanoparticles as gene carrier in plant transformation and proves a novel approach for plant genetic decoration.



Comparative Analysis of Polysaccharides from Two Ecological Types of Leymus chinensis

LI Jing-jing, BI Hong-tao, YAN Ji-hong, SUN Fang, FAN Sha-sha, CAO Gang, ZHOU Yi-fa, CHEN Xi-guang

2012, 28(4):  677-681. 

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Leymus chinensis(Trin.) Tzvel., widely distributed at eastern Eurasian steppe and divided into gray-green type and yellow-green type, has different stress resistance to environment. In the present study, the water-soluble polysaccharides from two ecotypes of L. chinensis were analyzed in detail, and the differences between polysaccharides from the two ecotypes of L. chinensis in the yield, monosaccharide composition, molecular weight and structure were clarified. The polysaccharides of L. chinensis were composed of both neutral and acidic polysaccharides. The neutral polysaccharides contained mannose, glucose, galactose, xylose and arabinose, and mainly consisted of β-1,4-Glcp, α-1,3-Galp and α-1,2-Xylp residues. The acidic polysaccharides contained mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and arabinose. However, the yields, monosaccharides contents and the molecular weights of the polysaccharides from the two ecotypes of L. chinensis were different. Moreover, the resistance type(gray-green type) of L. chinensis contained a number of α-1,3-Manp and reducing end of β-Glcp residues, and much more O-methyl groups than normal type(yellow-green type) of L. chinensis. The differences of the polysaccharides of the two ecotypes of L. chinensis might be due to the long-term environmental adaptability of plant, and the differences of the polysaccharides might influence the stress resistance of L. chinensis.



Cyclodextrin Polymer Films Optical Waveguide Sensor for Volatile Organic Gas Detection

YASIN Patime, YIMIT Abliz, RAHMAN Ebeyla, NIZAMIDIN Patima

2012, 28(4):  682-685. 

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A sensitive optical waveguide(OWG) sensor which can be used to detect volatile organic compounds(VOCs) was presented. The sensing device(element) was fabricated by means of the immobilization of polyvinyl pyrrolidone(PVP)-cyclodextrin(CD) composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method. The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1-1000 μL/L.



Structure Evolution and Electrochemical Performance of Al₂O₃-coated LiNi_0.4Co_0.2Mn_0.4O₂ During Charge-discharge Cycling

LIU Hao-han, ZHANG Jian, LOU Yu-wan, YANG Chuan-zheng, XIE Xiao-hua, XIA Bao-jia

2012, 28(4):  686-690. 

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Several lithium-ion batteries of 18650-type were assembled with pristine or Al₂O₃-coated LiNi_0.4Co_0.2Mn_0.4O₂(NCM) as cathode material and mesocarbon microbeads(MCMB) as anode material. The cycling performance of the batteries was examined under 25℃ at a 2C rate within a potential range of 2.75-4.20 V. The changes of the crystal structure, the lattice parameter, the mean crystallite size, and the mean micro-strain of pristine NCM and Al₂O₃-coated NCM during the charge-discharge cycling were determined by X-ray diffraction(XRD). The results indicate that the bulk structure of Al₂O₃-coated NCM is more stable than that of pristine NCM, which leads to the better cycling performance of Al₂O₃-coated NCM compared to that of pristine NCM.



Corrosion Inhibition of Imidazoline Derivates with Benzene Rings on Mild Steel in CO₂-Saturated Brine Solution

CHEN Guo-hao, ZHAO Jing-mao

2012, 28(4):  691-695. 

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Corrosion inhibition of three imidazoline derivates with different numbers of benzene rings, namely 2-phenyl-1-ethylamino imidazoline(CI-1), 2-phenyl-1-ethylamino-1-methylbenzyl quaternary imidazoline(CI-12) and 2-phenyl-1-benzoyl ethylamino imidazoline(CI-13), on mild steel in CO₂-saturated brine solution was evaluated by mass-loss method and potentiodynamic polarization method. The results show that the three imidazoline derivates can inhibit CO₂ corrosion effectively with CI-12 ranking the highest. They mainly restrain the anodic dissolution and act as anodic-type inhibitors. The adsorptions of these derivates on the mild steel surface follow the Langmuir adsorption isothermal equation and belong to chemical adsorption.



Theoretical Studies on Structural and Spectroscopic Properties of Photoelectrochemical Cell Ruthenium Sensitizers-the Derivatives of N3

CHEN Jie, WANG Jian, BAI Fu-quan, ZHENG Qing-chuan, ZHANG Hong-xing

2012, 28(4):  696-702. 

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A series of dye molecules was designed theoretically. Particularly, azoles and their derivatives were chosen as the modifying groups linking to ancillary ligands of [Ru(dcbpyH₂)₂(NCS)₂](N3, dcbpy=4,4′-dicarboxy- 2,2′-bipyridine; NCS=thiocyanato). Density functional theory(DFT) based approaches were applied to exploring the electronic structures and properties of all these systems. The dye molecule with 1,2,4-triazole groups which exhibits a very high intensity of absorption in visible region, was obtained. Time-dependent DFT(TD-DFT) results indicate that the ancillary ligand dominates the molecular orbital(MO) energy levels and masters the absorption transition nature to a certain extent. The deprotonation of anchoring ligand not only affects the frontier MO energy levels but also controls the energy gaps of the highest occupied MO(HOMO) to the lowest unoccupied MO(LUMO) and LUMO to LUMO+1 orbital. If the gap between LUMO-LUMO+1 is small enough, the higher efficiency of dye-sensitized solar cell(DSSC) should be expected.



Asymmetric Photochemical Reaction of 5-Methylbicyclo[1.1.1]-pentanyl Ketone

WANG Xiao-lin, ZHANG Ke

2012, 28(4):  703-706. 

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The density functional theory(DFT) calculations were performed to investigate a typical Norrish/Yang type II photoreaction of 5-methylbicyclo[1.1.1]-pentanyl ketone. The results reveal the essential correlation between structures on the one hand and energies, on the other hand, of the reactants, transition states and products based on both singlet ground(S₀) and triplet excited(T₁) potential energy surfaces. The feasible mechanism indicates that an intramolecular Norrish/Yang cyclization reaction takes place via H-abstraction to obtain the sole chiral cyclobutanol photoproduct. The located crossing point plays an important role in the cyclization process, which permits intersystem crossing(ISC) from T₁ to S₀ state. The rate-determining step may be to experience ISC between two different potential energy surfaces, requiring sufficient time for electron spin reversion, i.e., spin multiplicity alteration. These conclusions are further confirmed by the second-order M鴏ler-Plesset perturbation theory(MP2) calculations.



Improving Sensitivity of Enzyme to Organophosphorous Compounds by Combining Experiment and Theory Methods

WANG Yue-xi, WANG Ye, HAN Wei-wei, FENG Yan

2012, 28(4):  707-711. 

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In this paper, we compared the sensitivities of AFEST(a thermophilic esterase from the archaea Archaeoglobus fulgidus) and acetylcholinesterase(AChE) towards five organophosphorus compounds(OPs) by means of molecular docking, and found that only the docking energy between AFEST and dichlorvos is lower than that between AChE and dichlorvos. Via the docking model of AFEST and dichlorvos, Arg43 was found to play an important role in the interaction between AFEST and dichlorvos by means of stabilizing the complex. Then mutant R43S was constructed, the IC₅₀(the concentration required to reduce virus-induced cytopathicity by 50% is estimated as 50% inhibitory concentration) of which to dichlorvos was lower than that of the wild type AFEST by a factor of 1.56, indicating the enhanced sensitivity of mutant R43S to dichlorvos. Combining of theory with experiment, we have obtained important structure-function information of AFEST, which will be helpful to the further studies of esterase.



Preparation and Photovoltaic Properties of p-Type Nano-ZnFe₂O₄

LI Zi-heng, ZOU Xu, LI Gen, ZOU Guang-tian

2012, 28(4):  712-715. 

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p-Type nano-ZnFe₂O₄ semiconductors were gained by high-prssure treatment. Surface photovoltaic spectrum(SPS) and transient photovoltaic technology(TPV) were used for studying the photogenerated charge of nano-ZnFe₂O₄. Results show that the photovoltaic behavior of nano-ZnFe₂O₄ changed as the processing pressure increased. When the processing pressure was higher than 2 GPa, both SPS response interval and peak changed significantly. XPS results show that the non-lattice oxygen entered into the lattice and the content of lattice oxygen increased with the increase of processing pressure. The material changed from oxygen vacancy type to oxygen excess type and the photoelectric properties changed from n-type to p-type when the processing pressure is higher than 2 GPa.



Synthesis, Crystal Structure and Thermal Behavior of 4,5-Dimethoxy-2-(dinitromethylene)imidazolidine

WANG Min, XU Kang-zhen, HE Fei, ZHANG Hang, CHEN Yong-shun, SONG Ji-rong, ZHAO Feng-qi

2012, 28(4):  716-720. 

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A new energetic material, 4,5-dimethoxy-2-(dinitromethylene)imidazolidine(DMDNI), was synthesized by the reaction of 4,5-dihydroxyl-2-(dinitromethylene)-imidazolidine(DDNI) and methanol, and structurally characterized by single crystal X-ray diffraction. DMDNI crystallized in triclinic space group P, with crystal data a=0.4324(4) nm, b=1.3599(11) nm, c=1.7503(14) nm, α=77.406(14)°, β=84.494(15)°, γ=87.976(14)°, V=0.9997(14) nm³, Z=4, μ＝0.140 mm^-1, F(000)=488, D_c=1.556 g/cm³, R₁=0.0773 and wR₂=0.1574. Thermal decomposition of DMDNI was studied, and its thermal decomposition process was divided into two stages. The first stage was a mel- ting process and the second stage was an exothermic decomposition process. The enthalpy, apparent activation energy and pre-exponential constant of the exothermic decomposition reaction are -491.5 J/g, 142.3 kJ/mol and 10^14.24 s^-1, respectively. The critical temperature of thermal explosion is 162.47℃. DMDNI has a lower thermal stability than DDNI but it is close to that of 4,5-diacetoxyl-2-(dinitromethylene)-imidazolidine(DADNI).



Facile Preparation and Visible-light Photocatalysis Enhancement of N-Doped β-TiO₂ Nanobelts

JI Tian-hao, LIU Yang, DONG Li-ya, HAN Peng, SUN Jia-yue

2012, 28(4):  721-726. 

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A facile preparation of nitrogen-doped β-TiO₂(N-doped β-TiO₂) nanobelts and their visible-light photocatalytic activity were reported. The preparation of N-doped β-TiO₂ nanobelts consisted of cation-exchange between layered sodium titanate nanobelts and NH₄⁺ in aqueous solution at room temperature and subsequent calcination in air. Such a calcination treatment is beneficial to the formation of monoclinic N-doped β-TiO₂ nanobelts. Various measurement results indicate that not only were the nitrogen atoms doped into the lattice of β-TiO₂ nanobelts resulting in a strong visible-light absorption, but also a large number of defects were caused by them in the lattice, increasing the stability of β-TiO₂. The photocatalysis enhancement of N-doped β-TiO₂ nanobelts for the photodegradation of Rhodamine B was demonstrated.



Preparation and Photocatalysis of Mesoporous TiO₂ Nanofibers via an Electrospinning Technique

WANG Wei, YUAN Qing, CHI Yue, SHAO Chang-lu, LI Nan, LI Xiao-tian

2012, 28(4):  727-731. 

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Mesoporous TiO₂ nanofibers have been synthesized by a new method that combines sol-gel chemistry and electrospinning technique. The obtained mesoporous TiO₂ nanofibers were characterized with scanning electron microscopy(SEM), X-ray diffraction(XRD), transmission electron microscopy(TEM) and nitrogen adsorption-desorption isotherms. The photocatalytic performance was evaluated by the photocatalytic degradation of Rhodamine B under UV light irradiation. The results show that mesoporous TiO₂ nanofibers exhibit higher photocatalytic activity compared with nonporous TiO₂ nanofibers.



Responses of Transmembrane Peptide and Lipid Chains to Hydrophobic Mismatch

YANG Lei, LI Jian-tao, QI Hai-yan, LI Fei

2012, 28(4):  732-736. 

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Hydrophobic mismatch between the hydrophobic length of membrane proteins and hydrophobic thickness of membranes is a crucial factor in controlling protein function and assembly. We combined fluorescence with circular dichroism(CD) and attenuated total reflection infrared(ATR-IR) spectroscopic methods to investigate the behaviors of the peptide and lipids under hydrophobic mismatch using a model peptide from the fourth transmembrane domain of natural resistance-associated macrophage protein 1(Nramp1), the phosphatidylcholines(PCs) and phosphatidylglycerols(PGs) with different lengths of acyl chains(14:0, 16:0 and 18:0). In all PG lipid membranes, the peptide forms stable a-helix structure, and the helix axis is parallel to lipid chains. The helical span and orientation hardly change in varying thickness of PG membranes, while the lipid chains can deform to accommodate to the hydrophobic surface of embedded peptide. By comparison, the helical structures of the model peptide in PC lipid membranes are less stable. Upon incorporation with PC lipid membranes, the peptide can deform itself to accommodate to the hydrophobic thickness of lipid membranes in response to hydrophobic mismatch. In addition, hydrophobic mismatch can increase the aggregation propensity of the peptide in both PC and PG lipid membranes and the peptide in PC membranes has more aggregation tendency than that in PG membranes.



Influence of Surfactant-polymer Complexes on Crystallization and Aggregation of CaCO₃

PAN Yan, GUO Yu-peng, ZHAO Xu, WANG Zi-chen

2012, 28(4):  737-742. 

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Hollow calcium carbonate(CaCO₃) microspheres with different morphologies were synthesized via the precipitation reaction of calcium chloride with sodium carbonate in the presence of different surfactant-polymer complexes. The selected anionic surfactants were sodium dodecyl sulfonate(SDS) and sodium dodecyl benzenesulfonate(SDBS), respectively. The selected water-soluble polymers were polyacrylic acid(PAA) and polyvinyl pyrrolidone(PVP). In this work, SDS-PVP “pearl-necklace model” micellar complex was formed via hydrophobic effectiveness between SDS and PVP and it served as the spherical template to generate spherical CaCO₃ aggregates with hollow microspheres composed of about 500 nm irregular shaped particles. SDS-PAA complexes and SDBS-PAA complexes formed “core-shell model” aggregates with calcium ions serving as the medium to link the anionic surfactant and the polymer. SDS-PAA “core-shell model” aggregates would act as templates for hollow CaCO₃ microspheres consisting of 30-50 nm irregular shaped crystallites. SDBS-PAA “core-shell model” aggregates served as the spherical aggregate templates to generate spherical CaCO₃ aggregates consisted of many small spherical particles which had grown together. All the obtained CaCO₃ hollow microspheres are calcite particles. This research may provide new insight into the control of morphologies of hollow CaCO₃ microspheres in the presence of surfactant- polymer complexes.



Dissolution Properties of 2-(Dinitromethylene)-5-methyl-1,3-diazacyclopentane in Dimethyl Sulfoxide and N-Methyl Pyrrolidone

XIAO Li-bai, XING Xiao-ling, ZHAO Feng-qi, XU Kang-zheng, YAO Er-gang, TAN Yi, HAO Hai-xia

2012, 28(4):  743-746. 

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The molar enthalpies of dissolution for 2-(dinitromethylene)-5-methyl-1,3-diazacyclopentane(DNMDZ) in dimethyl sulfoxide(DMSO) and N-methyl pyrrolidone(NMP) were measured using an RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the molar enthalpies of dissolution(Δ_dissH) were obtained from the experimental data of the dissolution processes of DNMDZ in DMSO or NMP. The relationships between the rate constant(k) and the molality(b) and between the reaction order(n) and the molality(b) were determined. The corresponding kinetic equations describing the two dissolution processes were dα/dt=10^-2.16(1-α)^1.01 for the dissolution of DNMDZ in DMSO, and dα/dt=10^-2.02(1-α)^0.85 for the dissolution of DNMDZ in NMP, respectively.



Alumina/Polyimide Composite Porous Nanosolid: Dielectric Characteristics and Compressive Strength

LUAN Chun-hong, GENG Yu-jing, YU Qin-qin, CAO Li-li, LIAN Gang, CUI De-liang

2012, 28(4):  747-751. 

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Al₂O₃ porous nanosolid was prepared via solvothermal hot-press(SHP) method. The dielectric constant of Al₂O₃ porous nanosolid is as low as 2.34, while its compressive strength is very poor. In order to improve the compressive strength and maitain low dielectric constant, polyimide was introduced to prepare Al₂O₃/polyimide composite porous nanosolid. Compared to Al₂O₃ porous nanosolid, Al₂O₃/polyimide composite porous nanosolid possesses much higher compressive strength, which reaches its saturation value when the mass loading of polyimide is 7.75%. In addition, the in situ Fourier transformation infrared(FTIR) monitoring result reveals that Al₂O₃/polyimide composite porous nanosolid is stable up to 400℃.



Properties, Morphology and Structure of BPDA/PPD/TFMB Polyimide Fibers

HUANG Sen-biao, GAO Zhong-min, MA Xiao-ye, GUO Hai-quan, QIU Xue-peng, GAO Lian-xun

2012, 28(4):  752-756. 

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The mechanical properties of fibers were notably improved by incorporating 2,2′-bis(trifluoromethyl)- benzidine(TFMB) into 3,3′,4,4′-biphenyltetracarboxylic dianhydride(s-BPDA) and p-phenylenediamine(PPD) backbone. The best strength and modulus of BPDA/PPD/TFMB polyimide(PI) fiber(diamine molar ratio of PPD/TFMB= 90/10) were 1.60 and 90 GPa, respectively, which was over two times that of BPDA/PPD PI fiber. SEM image showed that the cross-section of fibers at each stage was round and voids free. Besides, the “skin-core” and microfibrillar structure were not observed. The thermal properties of PI fibers were also investigated. The results showed that the fibers owned excellent thermal stability, moreover, the structural homogeneity of fibers were significantly improved by heat-drawn stage. The T_g values were found to be around 300℃ by dynamic mechanical analysis(DMA). Wide angle X-ray diffraction(WAXD) and small angle X-ray scattering(SAXS) experiments indicated that the order degree of longitudinal and lateral stacks, the molecular orientation and the structural homogeneity of fibers were improved in the preparation process of fibers.