JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2018
·Vol. 93
·期 11
·3176-3184
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IF 2.587
Muhammad Bilal,Sheng-Jie Yue,Hong-Bo Hu,Wei Wang,Xue-Hong Zhang
BACKGROUND Pseudomonas chlororaphis GP72 is a biocontrol strain with great capacity to produce a wide range of secondary metabolites including phenazine derivatives. Phenazine-1-carboxylic acid (PCA) is an environmentally friendly antibiotic with broad-spectrum biological and pharmaceutical activities. Many studies have been focused on engineering high-yielding strains and optimizing fermentation bioprocesses to enhance PCA biosynthesis. However, the separation and purification of PCA in biotechnological production remain to be addressed. In this context, the present work intended to develop a simple and proficient technique for the separation and purification of PCA from the fermentation broth of engineered P. chlororaphis GP72AN. RESULTS Five macroporous adsorbents with different physicochemical characteristics were screened to present their PCA separation potential. Among them, HP-20 resin was found highly suitable based on its promising adsorption and desorption performance in a static batch process. Langmuir and Freundlich isotherms deciphered the solute binding affinity towards HP-20 adsorbent at varying temperatures, and the experimental data fitted best to the Langmuir isotherm model. The column-assisted dynamic adsorption–desorption trials were executed to optimize the functional parameters for PCA separation. Under standardized separating conditions, the average adsorption capacity and desorption ratio of PCA were 24.4 ± 1.5 mg g −1 dry resin and 86.5 ± 1.3%, respectively. After treatment with HP-20 resin, PCA contents in the product were considerably increased with a recovery yield of 78.4 ± 2.4%. CONCLUSION In conclusion, the method proposed herein achieved effective separation and purification of PCA by applying HP-20 resin. The results obtained also suggest an encouraging basis for scale-up preparation of PCA and other high-value phenazine compounds of industrial interests. © 2018 Society of Chemical Industry
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
·
IF 4.229
Xiubing Huang,Jie Feng,Hassan R.S. Abdellatif,Jing Zou,Guan Zhang,Chengsheng Ni
Mn-substituted double perovskites , PrBaCo 2-x Mn x O 5+δ (x = 0, 0.5, 1), are evaluated as cathode materials for intermediate-temperature solid oxide fuel cells. The effects of Mn substitution content on their structural and electrochemical properties including crystal structure, thermal expansion coefficient , and cathodic interfacial polarization resistance are investigated. The PrBaCo 2-x Mn x O 5+δ samples exhibit structural changes with increasing Mn contents from tetragonal (x = 0) to cubic (x = 0.5 and 1.0) symmetry. The thermal expansion coefficient decreases with the increasing Mn content while the cathodic performance increases with the increment of Mn content from x = 0 to x = 0.5 then decreases with the further increment of Mn content from x = 0.5 to x = 1.0. When using La 0.8 Sr 0.2 Ga 0.8 Mg 0.15 Co 0.05 O 3 with 300 μm thickness as electrolyte and Sr 2 Fe 1.4 Ni 0.1 Mo 0.5 O 6-δ as anode, the maximum powder density of the x = 0.5 composite is 0.638 W cm −2 , which is higher than that of the other two samples with x = 0 (0.474 W cm −2 ) and x = 1.0 (0.371 W cm −2 ) at 800 °C.
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EBioMedicine
·
2018
·
IF 6.183
Aiyun Li,Qun Liu,Qiang Li,Baolin Liu,Yang Yang,Ning Zhang
Background Mitochondrial pyruvate import via mitochondrial pyruvate carrier (MPC) is a central step in hepatic gluconeogenesis. Berberine inhibits hepatic gluconeogenesis, but the mechanism is incompletely understood. This study aims to investigate whether berberine could reduce excessive hepatic glucose production (HGP) by limiting mitochondrial import of pyruvate through MPC1. Methods High-fat diet (HFD) feeding augmented HGP. The effects of berberine on hepatic fatty acid oxidation, sirtuin3 (SIRT3) induction and mitochondrial pyruvate carrier 1 (MPC1) function were examined. Findings HFD feeding increased hepatic acetyl coenzyme A (acetyl CoA) accumulation with impaired pyruvate dehydrogenase (PDH) activity and increased pyruvate carboxylase (PC) induction. Berberine reduced acetyl CoA accumulation by limiting fatty acid oxidation and prevented mitochondrial pyruvate shift from oxidation to gluconeogenesis through carboxylation. Upon pyruvate response, SIRT3 binded to MPC1 and stabilized MPC1 protein via deacetylation modification, facilitating mitochondrial import of pyruvate. Berberine preserved the acetylation of MPC1 by suppression of SIRT3 induction and impaired MPC1 protein stabilization via protein degradation, resultantly limiting mitochondrial pyruvate supply for gluconeogenesis. Interpretation Berberine reduced acetyl CoA contents by limiting fatty acid oxidation and increased MPC1 degradation via preserving acetylation, thereby restraining HGP by blocking mitochondrial import of pyruvate. These findings suggest that limitation of mitochondrial pyruvate import might be a therapeutic strategy to prevent excessive hepatic glucose production.
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PubMed
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APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Guojun Lv,Senlin Deng,Yi Zhai,Yongqiang Zhu,Haichao Li,Fumin Wang,Xubin Zhang
Hierarchical TS-1 stacked nanoplates with constrained mesopores were hydrothermally synthesized via a self-assembly process with the aid of P123 lamellar micelles. P123 lamellar micelles serve concomitantly as mesotemplate for hierarchical TS-1 zeolite and nanostructure regulator for TS-1 nanoplates. The successful preparation of TS-1 stacked nanoplates were verified by Scanning and Transmission electron microscope, X-ray diffraction patterns, FTIR spectra and UV–vis spectra. Moreover, their formation processes with crystallization time were investigated, and accordingly the possible mechanism was proposed. Hierarchical TS-1 stacked nanoplates displayed a chemical composition similar to that of hierarchical TS-1 zeolite with P123 spherical micelles as mesotemplate and showed remarkably enhanced catalytic activity in oxidative desulfurization of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and benzothiophene (BT) with tert-butyl hydroperoxide (TBHP) or hydrogen peroxide (H 2 O 2 ) as oxidant.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 3
·514-520
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IF 1.071
Liu Guomin,Li Yalong,Yang Shuting,Zhao Yi’an,Lu Tiancheng,Jia Wenyuan,Ji Xuan,Luo Yungang
To explore the ability of dihydroxyphenylalanine-insulin-like growth factor-1(DOPA-IGF-1) coated hydroxyapatite/poly(lactic-co-glycolic acid)(HA/PLGA) microspheres to promote the proliferation and osteoclastic differentiation of rabbit bone mesenchymal stem cells(rBMSCs), HA/PLGA microspheres with different HA content (10%, 30%, 50%, mass fraction) were prepared by electrospinning method and HA/PLGA microspheres with 50% HA were coated with IGF-1 and DOPA-IGF-1, respectively. They were co-cultured with rBMSCs, respctively. Cell counting kit-8(CCK-8) detection, confocal laser scanning microscopy(CLSM), alkaline phosphatase(ALP) detection and osteogenesis related genes COL1A1 , Runx2 and bone morphogenetic protein-2( BMP-2 ) detection were conducted to detect the proliferation activity, cell morphology, differentiation ability and the expression level of osteogenesis-related genes of cells cultured on all microspheres groups. The results showed that rBMSCs proliferation increased in an HA content dependent manner, and cells proliferated more in the IGF-1 coated and DOPA-IGF-1 coated groups, in particular in DOPA-IGF-1 coated group, and the differences were more remarkable over time ( P <0.05). HA/PLGA microspheres promoted the proliferation and osteogenic differentiation of rBMSCs, and DOPA-IGF-1 coating enhanced the proliferation and osteogenic differentiation of rBMSCs.
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FOOD CHEMISTRY
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2018
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IF 4.946
Ying Zhou,Qiyuan Peng,Ling Zhang,Sihua Cheng,Lanting Zeng,Fang Dong,Ziyin Yang
1-Phenylethanol is a chiral flavor compound that has enantiomers, ( R )- and ( S )-1-phenylethanol, with different flavor properties. Given that isolating these enantiomers from plants is low yielding and costly, enzymatic synthesis presents an alternative approach. However, the genes/enzymes that specifically produce ( R )- and ( S )-1-phenylethanol in plants are unknown. To identify these enzymes in tea ( Camellia sinensis ) flowers, 21 short chain dehydrogenase (SDR) genes were isolated from tea flowers, cloned, and functionally characterized. Several recombinant SDRs in Escherichia coli exhibited activity for converting acetophenone to ( S )-1-phenylethanol (CsSPESs, >99.0%), while only one SDR produced ( R )-1-phenylethanol (CsRPES, 98.6%). A pair of homologue enzymes (CsSPES and CsRPES) showed a strong preference for NADPH cofactor, with optimal enzymatic reaction conditions of 45–55 °C and pH 8.0. Identification of the tea flower-derived gene responsible for specific synthesis of ( R )- and ( S )-1-phenylethanolsuggests enzymatic synthesis of enantiopure 1-phenylethanol is possible using a plant-derived gene.
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ACS Catalysis
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2018
·
IF 11.384
Yue Yan,Zihao Zhang,Seong-Min Bak,Siyu Yao,Xiaobing Hu,Zulipiya Shadike,Chi-Linh Do-Thanh,Feng Zhang,Hao Chen,Xilei Lyu,Kequan Chen,Yimei Zhu,Xiuyang Lu,Pingkai Ouyang,Jie Fu,Sheng Dai
Chemocatalysis of sugars to methyl lactate (MLA) exhibits great advantages over the conventional fermentation approach because of its higher productivity and cost-effective separation process. However, widely used supported metal oxide catalysts suffer from deactivation resulting from sintering during the reaction and removal of coke at high temperatures. Herein, we report ultrasmall cobalt oxide clusters (∼1.7 nm) stabilized within silicalite-1 crystals catalyst (CoO@silicalite-1), exhibiting superior catalytic activity and resistance to sintering for the conversion of fructose into methyl lactate. HAADF-STEM, EDS-mapping, and XRD experiments identify the existence of confined CoO clusters. XANES and Raman spectra demonstrated the covalent interaction between CoO and silicalite-1. Thanks to the ultrasmall CoO particle size (∼1.7 nm), the CoO@silicalite-1 affords nearly 100-fold higher Co-mass-based activity (mg MLA/mg Co) compared with CoO or Co3O4 particles outside the silicalite-1 framework. More importantly, this catalyst exhibits good reuse performance via the removal of coke with facile calcination.
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Journal of Cleaner Production
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2018
·
IF 5.651
Chen Fan,Hongqiang Dong,You Liang,Jiale Yang,Gang Tang,Wenbing Zhang,Yongsong Cao
Cyhalothrin is lethally toxic to aquatic organisms and has caused adverse effects in the hydrosphere . It is urgent to develop efficient and sustainable material for its removal. High-quality HKUST-1 was rapidly synthesized by cholinium ionic liquids (ILs) in water at room temperature. Yields of HKUST-1 showed obviously positive correlation with Hammett values of ILs. When applying CuCl 2 as a copper salt, the yield of products was reached up to 95.5%, which was much higher than that of reported research. The reaction could be readily scalable with high space-time yield (242512 kg m −3 d −1 ). Additionally, ZrO 2 @HKUST-1 composite was successfully synthesized through a sol-gel method without complicated heat treatment. The whole process eliminates the use of environmentally unfriendly solvents/amines and enables the production of material at a reasonable cost. The obtained HKUST-1 and ZrO 2 @HKUST-1 possessed large pore volume (0.88–0.95 cm 3 g −1 ) and high surface area (1152–1484 m 2 g −1 ). The composite material was used for the adsorption/degradation of cyhalothrin and showed superior photocatalytic activity under moderate visible light, as compared to pure ZrO 2 , HKUST-1 and commercial TiO 2 samples. ZrO 2 @HKUST-1 displayed the high cyhalothrin adsorption capacity of 333 mg g −1 through π−π stacking, which facilitated more target molecules to contact the composite in a short time. ZrO 2 incorporating with HKUST-1 protected ZrO 2 nanoparticles from rapid agglomeration, thus narrowed the band gap of the composite. Moreover, the formation of a junction between HKUST-1 and ZrO 2 effectively reduced the recombination of photoinduced carriers in composite. Therefore, the novel ZrO 2 @HKUST-1 composite can be used as a sustainable efficient heterogeneous photocatalyst for the removal of organic pollutant.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
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IF 2.037
Xiaoxing Lu,Di Wu,Dengfeng Ye,Youping Wang,Yongsheng Guo,Wenjun Fang
Two guanidinium-based ionic liquids (ILs), 2-ethyl-1,1,3,3-tetramethylguanidinium bis(trifluoromethylsulfonyl)imide ([TMGEt][NTf2]) and ethyl sulfate ([TMGEt][C2OSO3]) were synthesized and characterized. Experimental densities and viscosities for the binary mixtures of the ILs with ethanol and 1-propanol from (293.15 to 323.15) K were measured over the whole composition range and at the atmospheric pressure of 0.1 MPa. The excess molar volumes (VmE) and the viscosity deviations (Δη) for the binary systems were calculated and fitted with the Redlich–Kister equation. It is found that the density of [TMGEt][NTf2] is much higher than that of [TMGEt][C2OSO3] at the same temperature, while the viscosity of the former with the value of 74.61 mPa·s is only 1/9 of that of the latter at 293.15 K. This indicates that the difference of the anions has a significant influence on the density and viscosity of the ILs with the same guanidinium cation. The addition of ethanol or 1-propanol leads to negative values of VmE and Δη, which result from the efficient packing of the constituents in the binary mixtures and the weakening of anion–cation interactions of the ILs. The partial molar volumes, excess partial molar volumes, Gibbs energy, and excess Gibbs energy of activation for viscous flow of the binary mixtures also have been calculated. It is hoped that the results provide useful information for the fundamental physicochemical properties of the guanidinium-based ILs and their further applications.
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RSC Advances
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2015
·Vol. 5
·期 76
·62241-62247
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IF 3.84
Yibo He,Chao Wan,Qinghua Zhang,Xiaoli Zhan,Dang-guo Cheng,Fengqiu Chen
Friedel–Crafts alkylation of benzene with 1-dodecene, which is an important reaction of synthetic detergent, was studied using the catalyst [bmim][TFSI]/AlCl3 (1-butyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide/AlCl3). These ionic liquid catalysts show biphasic behaviors at a specific condition. Active site species and Lewis acidity were determined by NMR and acetonitrile probe FT-IR. NMR spectroscopy investigations indicated that “coordinated” and “uncoordinated” [TFSI]− existed in the ionic liquid catalyst system simultaneously, while tetrahedral 4-coordinate Al2Cl7− was the main active species for Friedel–Crafts alkylation. The complex [AlClx(TFSI)y]− tends to decompose and release 4-coordinated Al2Cl7− and [TFSI]−. The phase behavior study of the ionic liquid [bmim][TFSI]/AlCl3 demonstrated that the upper phase could be used as an efficient heterogeneous catalyst when AlCl3/IL ≥ 1.5. Due to the presence of the anion [TFSI]− around the active sites, especially [TFSI]− at the “uncoordinated” state, the ionic liquid formed a stable and hydrophobic chemical environment, which enhanced catalyst durability. The influence of various reaction conditions including catalyst reusability on the alkylation reaction was studied, and the potential reasons for catalyst deactivation were discussed. The highest 2-LAB selectivity was more than 50% when 1-dodecene conversion was nearly 100%. Compared with liquid or solid acid catalyst, ionic liquid catalysts have many advantages concerning energy and the environment.
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APPLIED CATALYSIS A-GENERAL
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2013
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IF 3.41
Cheng Liu,Jiale Huang,Daohua Sun,Yao Zhou,Xiaolian Jing,Mingming Du,Haitao Wang,Qingbiao Li
Anatase type extra-framework titanium in titanium silicate-1 (TS-1) molecular sieves has been observed to cause adverse catalytic impediments such as carbon–carbon bond cleavage and low H 2 O 2 efficiency during the epoxidation of terminal alkenes. In this study, a series of TS-1 sieves were synthesized, and used as catalysts for styrene epoxidation. Among the catalysts, the TS-1 with a Si/Ti molar ratio of 35 and 0.21 mol% of anatase type extra-framework titanium exhibited the best styrene conversion and styrene oxide (SO) selectivity. The results suggests that, framework Ti species have no effect on the stabilization of SO selectivity, whereas the synergetic interaction between the framework Ti species and the anatase type extra-framework titanium is essential for the outstanding catalytic performance of TS-1 in styrene epoxidation. In addition, our results demonstrate that the usage of tetraethyl orthosilicate (TEOS), tetrabutyl titanate (TBOT), and isopropyl alcohol in the synthesis of TS-1 does not guarantee the absence of extra-framework Ti species. Instead, the asynchronous degrees of hydrolysis between TEOS and TBOT might account for the formation of the anatase type extra-framework titanium. The influence of H 2 O 2 amount, reaction temperature and time, as well as the types of solvent, oxidant, and catalyst amount, on the catalytic performance of TS-1 with anatase type extra-framework titanium was likewise investigated.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2014
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IF 2.354
Chengcheng Ren,Fang Wang,Zhiqing Zhang,Huihui Nie,Nan Li,Mei Cui
A novel class of Gemini imidazolium surfactants 1,3-bis(3-alkylimidazolium-1-yl) propane bromide [C n -3-C n im]Br 2 ( n = 8, 10, 12) were synthesized and characterized by FT-IR, 1 H NMR and elemental analysis. The surface activity and aggregation behavior of [C n -3-C n im]Br 2 ( n = 8, 10, 12) were investigated by surface tension, conductivity and steady fluorescence methods. A series of surface active parameters, including cmc, Γ max , p C 20 , cmc/ C 20 , A min , γ cmc and Π cmc were obtained from surface tension measurement. It was indicated that Gemini imidazolium surfactants with the longer alkyl chain showed the higher surface activity. The thermodynamic parameters of micellization process, namely, standard Gibbs free energy (Δ G m ο ), enthalpy (Δ H m ο ) and entropy (Δ S m ο ) were derived from conductivity measurement at different temperatures. The micropolarity and the mean aggregation number ( N agg ) of micelles were evaluated from steady fluorescence spectra. The results revealed that the micropolarity and N agg of micelles decreased with the increase of hydrocarbon chain length.
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危险品化学品经营许可证（带存储）