APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Zhongkui Zhao,Xianhui Wang
The supported phosphotungstic acid catalysts on modified activated carbon (PTA/AC) prepared by a facile wet impregnation method were employed for Friedel–Crafts alkenylation of diverse aromatics with phenylacetylene to synthesize their corresponding α-arylstyrenes. Reaction results demonstrate that the fabricated PTA/AC catalyst with 30 wt.% PTA loading exhibits outstanding catalytic performance. The 100% conversion of phenylacetylene with 95.7% selectivity towards α-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N 2 adsorption–desorption, Fourier transform infrared spectroscopy, and NH 3 temperature-programmed desorption were employed to reveal the relationship between the catalysts nature and catalytic properties. Moreover, the results on the scope of aromatics for the Friedel–Crafts alkenylation illustrate that the developed PTA/AC alkenylation catalyst can be efficiently catalyze the diverse aromatics and even for the electron deficient chlorobenzene. The developed PTA/AC catalyst, using the modified low-cost and sustainable AC as support, may be a robust and promising candidate for highly-efficient and clean α-arylstyrenes production through Friedel–Crafts alkenylation of diverse aromatics including electron-donating and electron-withdrawing groups substituted benzene derivatives as well as heterocyclic and polypolycyclic arenes with phenylacetylene.
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JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 20
·6567-6577
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IF 2.371
Hu Caibiao,Zhao Guodong,Xia Qiang,Sun Rui
The present study investigated a self-double-emulsifying drug delivery system (SDEDDS) loaded with epigallocatechin-3-gallate (EGCG) and α-lipoic acid to improve EGCG photostability and possess a sustained release behavior. The long chain solid lipids (cetostearyl alcohol) and macadamia oil were utilized as a carrier to co-deliver the two bioactive ingredients. The prepared EA-SDEDDS for topical application was formulated using modified two-step method and characterized by confocal microscopy, in vitro release, and antioxidant effects. EA-SDEDDS was found to be stable under simulated sunlight for 1 month (at room temperature). In vitro cell culture studies, EA-SDEDDS provided protection for 3t3 fibroblasts that underwent H 2 O 2 oxidative stress due to sustained release property. Cellular antioxidant activity assay indicated that EA-SDEDDS showed anti-oxidative capacity with the same efficacy compared to EGCG-α-lipoic acid solution.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2015
·Vol. 16
·期 8
·17999-18017
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IF 2.862
Bin Li,Benguo Liu,Jiaqi Li,Huizhi Xiao,Junyi Wang,Guizhao Liang
Isoliquiritigenin (ILTG) possesses many pharmacological properties. However, its poor solubility and stability in water hinders its wide applications. The solubility of bioactive compounds can often be enhanced through preparation and delivery of various cyclodextrin (CD) inclusion complexes. The 6-O-α-d-maltosyl-β-CD (G2-β-CD), as one of the newest developments of CDs, has high aqueous solubility and low toxicity, especially stable inclusion characteristics with bioactive compounds. In this work, we for the first time construct and characterize the supermolecular structure of ILTG/G2-β-CD by scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD). The solubility of ILTG in water at 25 °C rises from 0.003 to 0.717 mg/mL by the encapsulation with G2-β-CD. Our experimental observations on the presence of the ILTG/G2-β-CD inclusion complex are further supported by the ONIOM(our Own N-layer Integrated Orbital molecular Mechanics)-based QM/MM (Quantum Mechanics/Molecular Mechanics) calculations, typically substantiating these supermolecular characteristics, such as detailed structural assignments, preferred binding orientations, selectivity, solvent effects, interaction energies and forces of the ILTG/G2-β-CD inclusion complex. Our results have elucidated how ILTG interacts with G2-β-CD, demonstrating the primary host-guest interactions between ILTG and G2-β-CD, characterized by hydrogen bonds, hydrophobic interactions, electrostatic forces, and conformational effects, are favored for the formation of the ILTG/G2-β-CD inclusion.Keywords:isoliquiritigenin;6-O-α-d-Maltosyl-β-CD;inclusion complex;ONIOM calculation
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2015
·Vol. 26
·期 5
·449-456
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IF 1.757
Xiangyu Liu,Jingwen He,Yile Niu,Yefei Li,Ding Hu,Xinnian Xia,Yanbing Lu,Weijian Xu
Photo-responsive block copolymer mPEG-b-poly(Tyr)-g-NB was prepared by introduction of o -nitrobenzyl ester group into the side chain of amphiphilic poly(ethylene glycol)-b-poly( α -hydroxy acids) (mPEG-b-poly(Tyr)) containing pendent alkynyl group via copper-catalyzed azide-alkyne cycloaddition reaction. The amphiphilic mPEG-b-poly(Tyr) was synthesized via the ring-opening polymerization of O -carboxyanhydrides, with monomethoxy poly(ethylene glycol) (mPEG) as macroinitiator. The molecular structure, self-assembly, and photo-controlled release of the obtained mPEG-b-poly(Tyr)-g-NB were thoroughly investigated. mPEG-b-poly(Tyr)-g-NB could self-assemble into spherical micelles in water and showed disassembly under UV light irradiation, which was demonstrated by means of UV-vis spectroscopy, scan electron microscopes, and dynamic light scattering measurement. Fluorescence emission measurements demonstrated that Nile red, encapsulated by micelles, can be released upon UV irradiation. This study provides a convenient way to construct smart poly( α -hydroxy acids)-based nanocarriers for controlled release of hydrophobic drugs. Copyright © 2015 John Wiley & Sons, Ltd.
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International Journal of Nanomedicine
·
2017
·
IF 4.3
Xiaoying Lei,Ke Li,Yan Liu,Zhen Yu Wang,Ban Jun Ruan,Li Wang,An Xiang,Daocheng Wu,Zifan Lu
A combination administration of chemical agents was highlighted to treat tumors. Recently, tumor cell has been found to be different from normal cell in metabolic manner. Most of cancer cells prefer aerobic glycolysis to mitochondrial oxidative phosphorylation (OXPHOS) to satisfy energy and biomass synthesis requirement to survive, grow and proliferate, which provides novel and potential therapeutic targets for chemotherapy. Here, 2-deoxy-d-glucose (2-DG), a potent inhibitor of glucose metabolism, was used to inhibit glycolysis of tumor cells; α-tocopheryl succinate (α-TOS), a water-insoluble vitamin E derivative, was chosen to suppress OXPHOS. Our data demonstrated that the combination treatment of 2-DG and α-TOS could significantly promote the anti-tumor efficiency in vitro compared with administration of the single drug. In order to maximize therapeutic activity and minimize negative side effects, a co-delivery nanocarrier targeting folate receptor (FR) was developed to encapsulate 2-DG and α-TOS simultaneously based on our previous work. Transmission electron microscope, dynamic light scattering method and UV-visible spectrophotometers were used to investigate morphology, size distribution and loading efficiency of the α-TOS-2-DG-loaded and FR-targeted nanoparticles (TDF NPs). The TDF NPs were found to possess a layer-by-layer shape, and the dynamic size was <100 nm. The final encapsulation efficiencies of α-TOS and 2-DG in TDF NPs were 94.3%±1.3% and 61.7%±7.7% with respect to drug-loading capacities of 8.9%±0.8% and 13.2%±2.6%, respectively. Almost no α-TOS release was found within 80 h, and release of 2-DG was sustained and slow within 72 h. The results of FR binding assay and fluorescence biodistribution revealed that TDF NPs could target FR highly expressed on tumor cell in vitro and in vivo. Further, in vivo anti-tumor experiments showed that TDF NPs had an improved biological function with less toxicity. Thus, our work indicates that the co-delivery TDF NPs have a great potential in tumor therapy.
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MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
S.T. Zhang,Y.R. Ruan,C. Liu,P. Wang,Y.Q. Ma
α-Fe/FeTiO 3 /TiO 2 was synthesized through the reduction of Fe 3 O 4 @TiO 2 at 800 °C, and subsequently nitrided in NH 3 atmosphere at the nitridation temperature T N = 400, 600, 800 and 1000 °C. In the crystal lattice of TiO 2 , with increasing T N , the N element itself exhibits the chemical states of TiO 2-x N x , TiN and interstitial N, and simultaneously it induces the complex variation of the chemical state of the Ti and O elements. The photocatalytic performance of the nitrided samples is not determined only by the chemical states of the N element but by the synergistic effects of chemical states of the N, Ti and O elements.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-13
·
IF 4.259
Zhao Wenwen,Feng Haitao,Guo Shuhui,Han Yantao,Chen Xiuping
ICAM-1 overexpression and subsequent adhesion of leukocytes to endothelial cells play critical roles in the early stage of atherosclerosis. Danshenol A (DA) is an abietane-type diterpenoid isolated from traditional Chinese herb Salvia miltiorrhiza Bunge. The mechanisms under its regulation of adhesion of molecular expression are explored. Here, the effect of DA on TNF-α-induced ICAM-1 expression was investigated in endothelial cells. TNF-α-induced ICAM-1 expression and subsequent adhesion of monocytes, as well as elevated reactive oxygen species (ROS) generation and NOX4 expression were all significantly reversed by DA, siNOX4 and NOX4 inhibitor GKT137831. Furthermore, TNF-α-induced ICAM-1 expression, which was increased via IKKβ/IκBα-mediated activation of NF-κB p65, was also inhibited by DA. Interestingly, NOX4 overexpression suppressed the ICAM-1 expression, and this finding may be ascribed to the activation of Nrf-2. Additionally, NF-κB inhibitor PDTC, siNOX4, or DA can decrease the TNF-α-induced ICAM-1 expression and suppress the adhesion of monocytes. In all, DA inhibited TNF-α-induced ICAM-1 expression and subsequent monocyte adhesion to endothelial cells through the NOX4-dependent IKKβ/NF-κB pathway. Besides, NOX4 played dual role in regulating ICAM-1 expression via diverse signal pathway. This novel bioactivity will make DA a good candidate to be further explored for therapeutic or preventive application for atherosclerosis.
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Analytical Methods
·
2016
·Vol. 8
·期 40
·7319-7323
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IF 1.915
Jisan Sun,Dazhi Tian,Qingjun Guo,Li Zhang,Wentao Jiang,Minghui Yang
A sensitive and selective electrochemical immunosensor for label-free detection of cancer biomarker α-fetoprotein (AFP) was developed based on hydroxyapatite (HAP) nanoparticles induced electrochemical current. HAP nanoparticles and graphene oxide (GO) were co-immobilized onto an electrode surface to modify the electrode. The phosphate groups contained in the HAP nanoparticles can react with molybdate to form redox molybdophosphate precipitates on the electrode surface, generating electrochemical current. GO enhanced the electrochemical current intensity due to its good conductivity. The following immobilization of the anti-AFP antibody and capture of AFP resulted in the formation of an immuno-complex layer on the electrode. This immuno-complex layer prevented the reaction of hydroxyapatite nanoparticles with molybdate, leading to the decrease of the electrochemical current, and the current change is proportional to the concentration of AFP detected. A wide linear range (0.01–10 ng mL−1) and low detection limit (5 pg mL−1) towards AFP detection were obtained. The reliability of the proposed immunosensor was evaluated by the detection of AFP in human serum samples. This study demonstrated the potential of the developed immunosensor in ultrasensitive detection of AFP or other biomarkers.
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Small
·
2016
·Vol. 12
·期 40
·5564-5571
·
IF 8.315
Ming Zhong,Donghui Yang,Chenchao Xie,Zhang Zhang,Zhen Zhou,Xian-He Bu
Manganese oxides (MnO x ) are promising anode materials for lithium ion batteries, but they generally exhibit mediocre performances due to intrinsic low ionic conductivity, high polarization, and poor stability. Herein, yolk–shell nanorods comprising of nitrogen-doped carbon (N–C) coating on manganese monoxide (MnO) coupled with zinc manganate (ZnMn 2 O 4 ) nanoparticles are manufactured via one-step carbonization of α -MnO 2 /ZIF-8 precursors. When evaluated as anodes for lithium ion batteries, MnO@ZnMn 2 O 4 /N–C exhibits an reversible capacity of 803 mAh g −1 at 50 mA g −1 after 100 cycles, excellent cyclability with a capacity of 595 mAh g −1 at 1000 mAg −1 after 200 cycles, as well as better rate capability compared with those non-N–C shelled manganese oxides (MnO x ). The outstanding electrochemical performance is attributed to the unique yolk–shell nanorod structure, the coating effect of N–C and nanoscale size.
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RSC Advances
·
2016
·Vol. 6
·期 88
·85367-85373
·
IF 3.289
Wenle Ma,Li Wang,Junying Xue,Hongtao Cui
Usually, monolayer-stated nanosheets of hydroxides have to be prepared by a multiple step layer-exfoliation processe, following “bottom-up” mechanism. The related preparative procedure is quite exhaustive and low yielding. In this work, α-Ni(OH)2 monolayer nanosheets were successfully synthesized in pure ethanol solution with a high yield using NaOH as a precipitant, based on a facile one-step “bottom-up” strategy. It was proposed that the water-deficient environment in ethanol solution could not provide adequate water molecules for the formation of hydrogen bond to link the layers, resulting in monolayer formation. Due to the large interface between the monolayer and electrolyte, the obtained monolayer nanosheets presented high electrochemical performance.
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RSC Advances
·
2017
·Vol. 7
·期 81
·51452-51459
·
IF 3.108
Lihua Xie,Xiaoyan Wang,Fengli Yu,Bing Yuan,Congxia Xie,Shitao Yu
Amphiphilic mesoporous silica modified with trimethoxy (3,3,3-trifluoropropyl) silane (TFPS) and (3-aminopropyl) trimethoxysilane (APTS) was prepared by one-step synthesis. The structure and morphology of the mesoporous silica were characterized and confirmed by solid-state nuclear magnetic resonance, X-ray diffraction (XRD), N2 adsorption–desorption, Fourier transfer infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Meanwhile, the thermostability of the amphiphilic mesoporous silica was detected by thermogravimetric (TG) technique. Highly dispersed Ru nanoparticles supported on such amphiphilic mesoporous silica (marked as Ru/MF@MN) were synthesized by wet impregnation method with the assistance of ultrasonic. The catalyst was characterized by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). In water medium, Ru/MF@MN was used in α-pinene hydrogenation to prepare cis-pinane. Under the optimum reaction conditions (35 °C, 2 MPa H2, 1 h, m (H2O) : m (α-pinene) : m (Ru/MF@MN) = 200 : 60 : 1), 99.9% α-pinene conversion and 98.9% cis-pinane selectivity were obtained. When Ru/MF@MN was recycled six times, the conversion slightly decreased and the selectivity was nearly unchanged.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2017
·
IF 3.743
Peng Xu,Ledan Huang
Populations of many amphibian species are declining worldwide in part because of pesticide contamination. As a surface water contaminant, α-cypermethrin may have severe ecological impacts on amphibians. Here, we examined the acute toxicity of α-cypermethrin enantiomers to dark-spotted frog Rana nigromaculata tadpoles at 24, 48, 72 and 96 h, finding that the tadpoles were indeed sensitive to α-cypermethrin. The (S)-(1R, 3R)-enantiomer was approximately 29 times more toxic than the (R)-(1S, 3S)-enantiomer at 96 h. A significant delayed growth in R. nigromaculata tadpoles after exposure to 0.5 µg L −1 of S-(1R, 3R)-cypermethrin was observed. Additionally, increased superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and malondialdehyde (MDA) levels indicate the presence of oxidative stress in the tadpoles. Further, tadpoles exposed to sublethal concentrations of α-cypermethrin enantiomers exhibited enantioselective growth and oxidative damage. Bioaccumulation experiments showed that the tadpoles could rapidly accumulate α-cypermethrin. The (R)-(1S, 3S)-enantiomer was preferentially accumulated over the (S)-(1R, 3R)-enantiomer, and it was also eliminated more quickly, as evidenced in the subsequent depuration experiments.
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