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February 15,2015
Volume 8,Issue 3
Pages -
Subject Area:Basic Subject of Chemical Engineering,Biochemical Engineering,Coal Chemical Engineering,Analytical Chemistry,Bioinorganic Chemistry,Coordination Chemistry

Title: Mechanism of synthesis of ethylene carbonate from urea and ethylene glycol: quantum chemistry computing

Authors: YANG Bolun, CHENG Jin, KANG Cheng, ZHANG Ying
PP: 296-304
Abstract: The mechanism for the synthesis of ethylene carbonate (EC) from urea and ethylene glycol (EG) has been studied based on the density functional theory (DFT). At the B3LYP/6-31G (d, p) level, the geometries of all species in the reaction system (reactants, isomers, transition states and products) were optimized. The transition states were validated by the vibrational frequency analysis and the calculations of the internal reaction coordinate (IRC). The computational results were as follows: firstly, transfer of H atoms was in every step of the reaction, and H-bond with hydroxyl of EG promoted the reaction; secondly, the reaction had two possible paths, direct-alcoholysis-elimination and decomposition-addition-elimination, and the main reaction pathway was the latter because of it’s low energy barrier. Finally, elimination reaction of 2-hydroxyethyl carbamate (HEC) to EC was the control step of entire reaction due to its highest energy barrier.
Keywords: basic subject of chemical engineering; reaction mechanism; density functional theory; urea; ethylene carbonate

Title: Purification and activity identification of white muscardin silkworm (Bombyx batryticatus) antioxidant peptide

Authors: WEN Shuisha, WANG Cailian, YANG Xuehai, LU Rushui, LI Canhui, WEN Cailing, LIU Wenbin
PP: 290-295
Abstract: In our current study, the antioxidant peptide was produced from enzymatic hydrolysate of white muscardin silkworm and was preliminary separated through the ultrafiltration. The antioxidant activity was analyzed. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity was used as the criterion for antioxidant activity. Peptides derived from trypsin hydrolysate exhibited the highest DPPH radical scavenging activity. Protein was enzymatically hydrolyzed at 50℃, pH=6.9, 0.31 g/L for enzyme concentration, 3.0 g/L for substrate concentration, 3.67 h for enzymatic hydrolysis time. DPPH clearance was 60%. After ultrafiltration to obtain the low-molecular weight peptide less than 3 ku, the DPPH scavenging activity arrived at 96%. The concentration for DPPH scavenging activity of 50% was 2 g/L, the total reductive activity and liposome oxidation inhibition was quite equal with ascorbic acid. High temperature treatment (boiling water bath) for 2.5 h as well as repeated freeze-thaw for 6 times, seemed not to affect the antioxi-dant activity. But the antioxidant activity decreased with the increasing storage days at room temperature.
Keywords: biochemical engineering; Bombyx batryticatus; antioxidant peptide; proteolysis; separation and puriffica-tion

Title: Effect of temperature on gas formation characteristics during pyrolysis of Huadian oil shale

Authors: LIANG Kun, LIANG Jie, LIU Jie, LIU Yongdong, LIU Kuan, LIU Tianze, GULAMBAR Matturzi
PP: 285-289
Abstract: The pyrolysis experiment with Huadian oil shale was conducted in a lab-made pyrolysis facilities to study the variations of instantaneous flow rate, components, contents and calorific value of pyrolysis gas with temperatures. It was found that instantaneous flow rate of gas products reached the most at 525℃. After 375℃, H2, CO, CH4, CO2, O2, C2H4, C2H6, C3H8 and C4 were the main components of the gas products. The content of H2 was the most while CH4 took second place. With the increase of the temperature, the content of H2 and CH4 increased at first and decreased later. The content of CO almost didn’t change. With the increase of the temperature, the gas calorific value reached the most at 4 599.66 kJ/m3, which was 37.2 times than that at 375℃.
Keywords: coal chemical engineering; oil shale; pyrolysis gas; temperature; instantaneous flow rate; calorific value

Title: Structural analysis of low molecular weight heparins

Authors: WANG Zhangjie, XU Xiaohui, LI Daoyuan, CHI Lianli
PP: 278-284
Abstract: Low molecular weight heparins (LMWH) are novel antithrombotic drugs prepared by either enzymatic or chemical depolymerization of heparin. In this study, systematic methodologies for fingerprinting analysis of LMWH were established. Reversed-phase ion-pairing liquid chromatography mass spectrometry (RPIP-LC-MS) approach revealed 36 components ranging from tetrasaccharides to hexacosasaccharides from enoxaparin. The partial digested fragments of enoxaparin was also analyzed using technique of RPIP-LC-MS. A total of 65 components from disaccharides to decasaccharides were characterized. RPIP-LC-MS coupled with pre-column derivatization was applied to analyze the exhaustive digests of enoxaparin. Besides the 8 natural common heparin disaccharides, many characteristic structures from enoxaparin, such as modified structures from both termini as well as 3-O-sulfated tetrasaccharides and trisaccharides, had been unambiguously identified.
Keywords: analytical chemistry; low molecular weight heparin; reversed-phase ion-pairing liquid chromatography mass spectrometry; intact chain; partial digestion; exhaustive digestion

Title: Enzyme-free detection of hydrogen peroxide based on 3DOM ionic liquid doped polyaniline inverse opals

Authors: Li Xinghua, Dai Lin
PP: 270-277
Abstract: In this paper, three-dimensional ordered macroporous (3DOM) ionic liquid doped polyaniline (IL-PANI) inverse opals modified electrode was prepared by using electropolymerization method for the enzyme-free detection of hydrogen peroxide (H2O2). The electrocatalytical behaviors of the electrochemical reduction of H2O2 were studied with cyclic voltammetry (CV) and amperometry. We found the suitable experimental parameters for amperometric detection of H2O2. The determination limit and the linear concentration range were also examined. The approach provided a linear response range between 0.05 mmol/L and 3.00 mmol/L with a detection limit of 16.7 μmol/L (signal-to-noise ratio S/N=3). This sensor which can be easily made and had a fast response and good sensitivity may be used to the routine detection of H2O2.
Keywords: analytical chemistry; electrochemical sensor; polyaniline; ionic liquid; hydrogen peroxide

Title: Dynamic structure of amyloid 餬 protein fragment A餬16-21 in aqueous solution

Authors: ZHUANG Danling, YAN Siyi, LIU Jia, CAI Kaicong
PP: 264-269
Abstract: Molecular dynamic simulations were performed for the amyloid 餬 protein fragment 16-21 (Aβ16-21) which is known as the factor of Alzheimer’s disease (AD) to gain insight into the conformational feature of A餬16-21 in aqueous solution. Statistic analysis was carried out on the all atoms trajectory. The understanding about the hydration effect and the microstructure around of amide units of A餬16-21, and the degree of the hydrogen effect between A餬16-21 and the water molecules were also revealed. These results provided the oretical insights and would be helpful for further pathological research of AD.
Keywords: physical chemistry; Alzheimer’s disease; amyloid 餬 protein; molecular dynamic simulations; structural dynamics

Title: Synthesis and characterization of Silicalite-1 with hierarchical porosity using monodisperse porous ploystyrene microspheres as template

Authors: YANG Xiaoyuan, WANG Zhuqian, KAN Qiubin, GUAN Jingqi
PP: 258-263
Abstract: The hierarchical Silicalite-1 was prepared by a template of poly(styrene-co-divinylbenzene) (PSD) microsphere with pore structure. The hierarchical porous Silicalite-1 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and nitrogen adsorption-desorption techniques. SEM proved that this kind of composite materials kept the original appearance shape characteristic of the template. XRD and infrared spectroscopy (IR) showed that it had a good MFI structure. Nitrogen ad-sorption-desorption isotherms demonstrated that the composite material had large pore volume.
Keywords: physical chemistry; hierarchial porous material; polystyrene microspheres; Silicalite-1

Title: Study on selective hydrogenation of diethyl oxalate to ethanol over SBA-15-supported Cu catalysts

Authors: LONG Pei, ZHENG Xinlei, ZHENG Jianwei, CHEN Jin, DUAN Xinping, YUAN Youzhu
PP: 251-257
Abstract: 25Cu/SBA-15 and 25Cu/SiO2-sol catalysts were prepared by an ammonia-evaporation method for the selective hydrogenation of diethyl oxalate (DEO) to ethanol. The results indicated that 25Cu/SBA-15 and 25Cu/SiO2-sol showed similar catalytic performance initially, but Cu/SBA-15 displayed a better thermal-resistant ability. Nearly 100% conversion of DEO and 87.3% selectivity to ethanol could be obtained under the optimized conditions [553 K, 3.0 MPa and 2.0 h 1 weight liquid hourly space velocity (WLHSV)]. Characterization studies revealed that dispersion and stability of copper nanoparticles were benefited from the formation of copper phyllosilicate species on the surfaces. The high surface area and the pore confinement of SBA-15 support have important contributions to the performance enhancement.
Keywords: physical chemistry; 25Cu/SBA-15; diethyl oxalate; ethanol; hydrogenation

Title: Study on fluorescent staining of counting Skeletonema costatum and its dead/alive assay

Authors: MENG Fanpeng, TAO Ping
PP: 246-250
Abstract: In this paper, a typical red tide algas, Skelrtonema costatum, was studied. Counting by fluorescent staining, a method to determine and count the dead/alive S. costatum cells was established by using fluorescein diacetate (FDA). The results showed that the dyeing rate of S. costatum (1.0 06 cells/mL) was 100%, when the concentration of FDA was 100.0 mg/L and the dyeing time was 10 min. Using the established method by counting the algae solution of S. costatum containing 0, 25%, 50%, 75%, 100% of dead cells, we found that the measured value was basically equal to the distribution value and the R2 value of the fitting curve was 0.997.
Keywords: bioinorganic chemistry; fluorescein diacetate; Skelrtonema costatum; fluoresence staining; counting; dead/live assay

Title: Surface modification of poly(ethylene glycol) derivative on floxuridine-layered double hydorxide (FL-LDH) nanohybrid

Authors: XU Jie, LI Dongxiang, XU Xinjie, HOU Wanguo,
PP: 240-245
Abstract: Surface modification of the layered double hydroxide (LDH) was of much importance for its stability, dispersity and biocompatibility as drug-carriers. In this paper, floxuridine (FL) intercalated LDH (FL-LDH) was modified with poly(ethylene glycol) monomethyl ether-sebacate salt (MPS). The obtained FL-LDH-MPS nanocomposites showed enhanced stability, dispersity and controlled drug release property. The obtained FL-LDH-MPS nanocomposites could have advantages as drug delivery system with controlled-release due to the biocompatible and water-soluble PEG shells with “stealth” function upon in-travenous injection.
Keywords: inorganic chemistry; layered double hydroxide; poly(ethylene glycol); floxuridine; nanohybrid; surface modification

Title: Preparation and application of polymeric aluminum ferric chloride from red mud

Authors: CHEN Miao, ZHANG Xiang, LI Ruige, DUAN Jianbang
PP: 236-239
Abstract: The polymeric aluminum ferric chloride (PAFC) was prepared by using red mud as raw materials. The leaching rate of Al and Fe were all above 80% and the basicity met the national standard (GB/T 22627—2008) under the optimum hydrochloric acid dosage and reaction temperature. The flocculation effect of PAFC on printing and dyeing wastewater was studied. Under the condition of PAFC=1.0 mL/L and pH=7-8, the removal rate of turbidity, chrominance and chemical oxygen demand (COD) were 95.2%, 90.3% and 85.6%, respectively.
Keywords: inorganic chemistry; polymeric aluminum ferric chloride; red mud; turbidity; chrominance; chemical oxygen demand

Title: Preparation and characterization of LaFeO3 nanofibers with different morphologies and their photocatalytic activity

Authors: GUO Meirong, LI Shudan
PP: 229-235
Abstract: In this paper, one-dimensional LaFeO3 fibers with several different morphologies were synthesized by electrospinning. The crystal structure and morphology were investigated by X-ray diffraction(XRD), scanning electron microscope SEM) and transmission electron microscope (TEM). The relationship between the morphology of fibers and the concentration of acetic acid and metal nitrate in the precursor solution were discussed. The effects of morphology on photocatalytic activity were also investigated. The results indicated that all the samples were orthorhombic perovskite. With concentration of acetic acid increasing in precursor solution, the morphologies of fiber were nano-porous belt-like fibers, nanofibers and nanorods, respectively. With concentration of metal nitrate increasing, the fibers were tended to be belt-like. The results of photocatalytic activity showed that LaFeO3 nano-porous fibers exhibited excellent photocatalytic activity.
Keywords: inorganic chemistry; LaFeO3; nanofibers; electrospinning; photocatalytic activity

Title: Design, synthesis and antitumor activities of novel bivalentβ-carbolines linked by alkylamino spacer

Authors: MA Qin, ZHANG Guoxian, FAN Wenxi, GUO Liang, LI Jianru, CAO Rihui
PP: 222-228
Abstract: Four novel bivalent β-carbolines with a spacer of three to six methylene units between the 3-methylamino group were synthesized from the starting material L-tryptophan by Spictet-Splengler condensation, oxidative decarboxylation, alkylation, oxidation, condensation and reduction. All compounds were evaluated against ten human tumor cell lines using thiazolyl blue (MTT) method. The chemical structures of all the newly synthesized compounds were characterized by electrosprany inonization mass spectrometry (ESI-MS), 1H NMR, 13C NMR and high resolution mass spectnometry(HRMS). The cytotoxic activities of all bivalent β-carbolines was evaluated in vitro against a panel of human tumor cell lines and compared with the reference drugs cisplatin. The results demonstrated that compound with a spacer of five methylene units exhibited more potent cytotoxic activities.
Keywords: organic chemistry; synthesis; bivalent β-carbolines; antitumor

Title: Synthesis, characterization and blue electroluminescent deviceapplications of all aryl substituted anthracene derivatives

Authors: ZHUANG Shaoqing ZHANG Wenzhi1, WANG Lei1
PP: 213-221
Abstract: 9-(1-naphthyl)-10-(9-phenanthrenyl) anthrancene (1-PNA) and 9-(2-naphthyl)-10-(9-phenanthrenyl) and thrancene (2-PNA), which were highly efficient blue anthracene derivatives modified by phenanthrene and naphthalene at 9 or 10 position, were synthesized and characterized. Compounds showed high quantum efficiency and reversible redox process. With respect to the three layer device 1-PNA and 2-PNA as the emitting layer, maximum current efficiency reached 2.64 cd/A, 4.60 cd/A with commission internationale del’eclairage (CIE) coordinates of (0.15, 0.10) and (0.16, 0.15). Interestingly, devices using all aryl fluorescent materials exhibited negligible efficiency rolling off at high current densities.
Keywords: photochemistry; phenanthrene; naphthalene; anthracene; organic light-emitting diode; efficiency roll-off

Title: Advanced in transition metal-catalyzed transformations offunctional groups on aromatic rings

Authors: SHI Liangliang, FU Hua
PP: 201-212
Abstract: Transformation of the functional groups is an important field of chemistry research. Transition metal-catalyzed conversion reaction of functional group on aromatic ring had achieved remarkable results. This article summarized the six aspects of transition metal catalyzed conversion of functional groups on the aromatic ring from the transition metal-catalyzed synthesis halogenated aromatic hydrocarbons, phenols, aromatic amines, aryl azide, nitrobenzene derivatives to aryl boronic acid ester. This review focused on the recent advance in transition metal-catalyzed transformation of the functional groups and discussed the application prospect of these methods to obtain more simple, efficient and less toxic catalysts.
Keywords: coordination chemistry; aromatic compounds; review; functional group transformation; transition metal-catalyzed

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