JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Miaoduo Deng,Shuang Li,Liangzhao Cai,Xingjie Guo
In this study, a hydroxypropyl-β-cyclodextrin (HP-β-CD) functionalized monolithic capillary column was prepared by one-pot sequential reaction for the first time. The preparation of the HP-β-CD functionalized monolithic column involves two sequential reactions in one pot: (1) the ring opening reaction between HP-β-CD and glycidyl methacrylate (GMA) catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU); (2) the copolymerization of GMA-HP-β-CD, ethylene dimethacrylate (EDMA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS). A series of monolithic columns were successfully prepared by varying the temperature of the ring opening reaction or several copolymerization parameters (the type and composition of porogenic solvents, ratio of GMA-HP-β-CD to EDMA and polymerization temperature). Then, the morphologies and structures of the resulting monolithic stationary phases were characterized by optical microscopy, scanning electron microscopy (SEM) and nitrogen adsorption analysis. Raman spectroscopy clearly indicated the successful bonding of HP-β-CD onto the monolith. When the prepared chiral stationary phase (CSP) was applied for the separation of a set of racemic compounds by capillary electrochromatography (CEC), including racemic anticholinergic drugs, β-adrenergic drugs, meptazinol and its intermediates, satisfactory separation selectivities were obtained. Additionally, the column also showed excellent separation abilities towards four flavanone glycosides epimers. Furthermore, the prepared monolithic columns exhibited satisfactory stability and reproducibilities of retention time, resolution and column efficiency. These results demonstrated the potential and usefulness of the developed one-pot sequential strategy in the preparation of other derivatized CD functionalized monolithic columns.
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高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Huazhen Liao,Song Ye,Yanling Shi,Deping Wang
Small size optical-magnetic bifunctional upconversion nanoparticles (UCNPs) that can be effectively triggered by 808 nm exhibit distinct advantages of improved tissue penetrating depth, minimized overheating effect, possible for multimodal imaging and high clearance rate, which therefore are considered as desirable candidates for bioapplications. In this research, the 808 nm triggered sub-20 nm β-NaYF 4 :Yb 3+ /Er 3+ @NaGdF 4 :Yb 3+ /Nd 3+ @NaGdF 4 active-core@active-shell@inert-shell structured UCNPs with optical and magnetic bifunctional properties were developed by seed-mediated growth method with NaOA as sodium source instead of the generally used NaOH. Through optimizing Nd 3+ doping concentration and outermost NaGdF 4 inert-shell thickness, the optical-magnetic bifunctional core-shell-shell structured UCNPs exhibited strong UC emission intensity and improved magnetic property . Furthermore, the core-shell-shell NPs were validated to be no cytotoxicity by cell viability assessment. Therefore, this research may open a general avenue for the synthesis of small size multifunctional UCNPs for practical bioapplications without overheating.
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RSC Advances
·
2018
·Vol. 8
·期 23
·12944-12950
·
IF 2.936
Yang Su,Li-Na Hao,Kun Liu,Jun Zhang,Liang Dong,Yunjun Xu,Yang Lu,Hai-Sheng Qian
Upconversion core–shell nanoparticles have attracted a large amount of attention due to their multifunctionality and specific applications. In this work, based on a NaGdF4 sub-10 nm ultrasmall nanocore, a series of core–shell upconversion nanoparticles with uniform size doped with Yb3+, Er3+ and NaDyF4 shells with different thicknesses were synthesized by a facile sequential growth process. NaDyF4 coated upconversion luminescent nanoparticles showed an obvious fluorescence quenching under excitation at 980 nm as a result of energy resonance transfer between Yb3+, Er3+ and Dy3+. NaGdF4:Yb,Er@NaDyF4 core–shell nanoparticles with ultrathin layer shells exhibited a better T1-weighted MR contrast.
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高影响因子
Soft Matter
·
2018
·Vol. 15
·期 7
·1551-1561
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IF 3.709
Meng Zhou,Yuanyuan Xia,Feng Cao,Na Li,Yacine Hemar,Shangwen Tang,Yang Sun
A predicted three-dimensional structure of bovine β-casein was constructed using homology modeling with the aid of MODELLER and I-TASSER programs, with the validity and reliability of the models evaluated according to stereochemical qualities and small angle X-ray scattering. By comparing the results obtained from the two models using the CRYSOL program, an optimal model of the β-casein structure derived from I-TASSER was selected and used in subsequent molecular dynamics (MD) analysis. 300 ns MD simulations of β-casein in water and in the presence of different SDS concentrations at 300 K were performed. The results of the MD simulations indicated that SDS molecules played a dual role in modifying the conformation of β-casein at 300 K. Concentrations of SDS below its CMC (1 mM), at which only the monomer form of SDS was present, induced β-casein to lose its secondary structure by converting helices into random coils; however the conformation of the complex was still comparable with that of native β-casein. In the presence of 10 mM SDS (above its CMC), the helical content of β-casein was increased along with reduced random coils, and the structural rearrangement led to a more compact conformation. The latter change is likely related to the hydrophobic interactions that dominate the binding of the C-terminal region, along with the anchoring of sulfate groups of SDS on the positively charged N-terminal portion via electrostatic attraction. Hydrogen bonding supplemented the SDS-induced stabilization of β-casein. A correlated “necklace and bead” model, in which the micelles nucleate on the protein hydrophobic sites, was proposed for the structure of β-casein–SDS complexes.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 22
·22244-22258
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IF 2.8
Yan Xuechao,Zhang Xiaoping,Li Qian
In this paper, an effective chitosan/beta-cyclodextrin/nanometer zinc oxide (CS/β-CD/Nano-ZnO) composite porous membrane was synthesized by sol-gel and polymer-assisted inverting method. Preparation conditions of CS/β-CD/Nano-ZnO were investigated by single-factor and Box-Behnken response surface methodology optimizing triethoxyvinylsilane (JH-V151), beta-cyclodextrin (β-CD), and nanometer zinc oxide (Nano-ZnO), and applied to study the adsorption characteristics of Cong red (CR) from aqueous solution using batch experiments. The optimum preparation conditions were determined that the volume fraction of JH-V151 alcohol solution was 11%, the ratio of β-CD to CS was 5.35, and the ratio of Nano-ZnO’s mass to solution’s volume was 0.36%. Different characterization methods including field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and Universal Materials Tester were used to prove the appearance, crystallinity, functional groups, swelling degree, transmittance, and tensile property of CS/β-CD/Nano-ZnO. The optimized batch experimental parameters were 50 mg L −1 , 4 h, 7.0, 0.5 g L −1 , and 55.0 °C as initial concentration, contact time, pH, adsorbent dose, and temperature, respectively. The maximum adsorption capacity on CR reached 96.33 mg g −1 , which is 4.34 times with respect to CS. The batch experimental data were best described by a pseudo-second-order kinetics model and Langmuir isotherm model ( R 2 = 0.9965, theoretical saturated adsorption capacity 147.28 mg g −1 ). The values ∆G were − 2.09, − 4.73, and − 7.37 kJ mol −1 at 298, 308, and 318 K temperatures, respectively. The ∆H value was 76.68 kJ mol −1 , indicating the endothermic and spontaneous adsorption in nature. The ∆S value was 0.26 kJ mol −1 K −1 , a signal of entropy increase during adsorption. The adsorption capacity decreased only by 5.8% after six recycling runs, which indicated the reusability of CS/β-CD/Nano-ZnO. Therefore, the CS/β-CD/Nano-ZnO composite porous membrane is a promising membrane material for the efficient removal of CR from any water at large and economic scales at moderate concentration.
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APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 102
·期 14
·6047-6056
·
IF 3.34
Zhang Zhi-Jun,Cai Rui-Feng,Xu Jian-He
A nitrilase from Hoeflea phototrophica DFL-43 (HpN) demonstrating excellent catalytic activity towards benzoylacetonitrile was identified from a nitrilase tool-box, which was developed previously in our laboratory for ( R )- o -chloromandelic acid synthesis from o -chloromandelonitrile. The HpN was overexpressed in Escherichia coli BL21 (DE3), purified to homogeneity by nickel column affinity chromatography, and its biochemical properties were studied. The HpN was very stable at 30–40 °C, and highly active over a wide range of pH values (pH 6.0–10.0). In addition, the HpN could tolerate against several hydrophilic organic solvents. Steady-state kinetics indicated that HpN was highly active towards benzoylacetonitrile, giving a K M of 4.2 mM and a k cat of 170 s −1 , the latter of which is ca. fivefold higher than the highest record reported so far. A cascade reaction for the synthesis of optically pure ( S )-β-phenylalanine from benzoylacetonitrile was developed by coupling HpN with an ω-transaminase from Polaromonas sp. JS666 in toluene-water biphasic reaction system using β-alanine as an amino donor. Various ( S )-β-amino acids could be produced from benzoylacetonitrile derivatives with moderate to high conversions (73–99%) and excellent enantioselectivity (> 99% ee ). These results are significantly advantageous over previous studies, indicating a great potential of this cascade reaction for the practical synthesis of ( S )-β-phenylalanine in the future.
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高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Guanghui Wang,Wenzhe Fan,Qin Li,Nansheng Deng
In this work, aspartic acid-β-cyclodextrin (ACD) was synthesized by the reaction of β-cyclodextrin with aspartic acid and epichlorohydrin, and graphene oxide-TiO 2 (GO-TiO 2 ) composite catalyst was prepared by a hydrothermal method. The complexation of ACD with New Coccine (NC) and Pb 2+ was characterized with FT-IR and XPS, respectively, the results show that ACD can simultaneously complex NC and Pb 2+ . XRD analysis and SEM images of GO-TiO 2 show that TiO 2 platelets are well distributed on both sides of the graphene oxide sheets, and display a similar XRD pattern to the pure TiO 2 nanoparticles with the typical diffraction peak of anatase phase. The effects of ACD on the photocatalytic degradation of NC and photocatalytic reduction of Pb 2+ were investigated in the single pollution system, and the synergistic effects on the simultaneous photocatalytic NC degradation and Pb 2+ reduction in the presence of ACD were also evaluated. The results showed that the presence of ACD was favorable to the acceleration of photocatalytic oxidation of NC and photocatalytic reduction of Pb 2+ in the single pollution system, and the photocatalytic reaction rate constants of NC and Pb 2+ in the presence of ACD increased 58% and 42%, respectively. For the combined pollution system, the synergistic effects on the simultaneous conversion of NC and Pb 2+ in aqueous solutions were also further enhanced. ACD enhanced photocatalytic activity was attributed to the improvement of the electron transfer and mass transfer at the GO-TiO 2 interface.
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MOLECULAR PHARMACEUTICS
·
2018
·
IF 4.556
Mingliang Pei,Jui-Yu Pai,Pengcheng Du,Peng Liu
Fluorescent hyper-cross-linked β-cyclodextrin-carbon quantum dot (β-CD-CQD) hybrid nanosponges of about 200 nm with excellent biocompatibility and strong bright blue fluorescence excited at 365 nm with a high photoluminescence quantum yield (PLQY) of 38.0% were synthesized for tumor theranostic application by facile condensation polymerization of carbon quantum dots (CQDs) with β-cyclodextrin (β-CD) at a feeding ratio of 1:5. The DOX@β-CD-CQD theranostic nanomedicine, around 300 nm with DOX-loading capacity of 39.5% by loading doxorubicin (DOX) via host–guest complexation, showed a pH responsive controlled release and released DOX in the simulated tumor microenvironment in a sustained release mode, owing to the formation constant in the supramolecular complexation of DOX with the β-CD units in the β-CD-CQD nanosponges. The proposed DOX@β-CD-CQD theranostic nanomedicine could be internalized into HepG2 cells, and the released DOX was accumulated into the cell nuclei, demonstrating an antitumor efficacy more enhanced than that of the free drug.
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高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Bo Chen,Sijiang Chen,Huinan Zhao,Yang Liu,Fengxia Long,Xuejun Pan
Ascribing to their significant differences in physicochemical properties , it is extremely challenging to treat complex wastewater containing more than one class of pollutants via one-step treatment. Here, we focused on disposal of complex wastewater bearing organic dye and heavy metal by using adsorptive method. Thus, by combining the advantages of polyethyleneimine (PEI), β-cyclodextrin (β-CD) as well as Fe 3 O 4 magnetic nanoparticles , a versatile β-CD and PEI bi-functionalized magnetic nanoadsorbent (Fe 3 O 4 -PEI/β-CD) with spatially separated sorption sites was successfully constructed for simultaneous capture of methyl orange (MO) and Pb(II) in complex wastewater. In this setting, β-CD cavities and positively charged N-containing groups of PEI were mainly responsible for removal of MO via host-guest inclusion and electrostatic attraction, respectively, and oxygen-bearing groups on the edge of β-CD as well as the free amino moieties in PEI acted as the active sites for Pb(II) uptake. In their individual mono-pollutant system, the adsorption processes can be better described via applying pseudo-second-order kinetic and Langmuir isotherm models. Interestingly, presence of MO in Pb(II)-MO binary system significantly promoted the uptake of Pb(II). But the coexisting Pb(II) had almost no effects on MO uptake. Such results demonstrated that both MO and Pb(II) could be simultaneously and synergistically removed by Fe 3 O 4 -PEI/β-CD through multiple mechanisms (such as electrostatic attraction, host-guest inclusion, chelating, etc.). Particularly, the excellent regeneration and stability make Fe 3 O 4 -PEI/β-CD an ideal integrative adsorbent for purification of actual wastewater contaminated by MO and Pb(II). Thus, this study provides some insights into designing a well-performed and easily recyclable adsorbent for simultaneous and synergetic capture of both organic and inorganic contaminants in complex wastewater.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaomei Qin,Lan Bai,Yizheng Tan,Lei Li,Fei Song,Yuzhong Wang
The currently reported adsorbents for wastewater purification generally have only limited adsorption capacity towards a single type of pollutant; few of them can simultaneously remove multiple types of pollutants from cocontaminated water with high efficiency. In this work, a kind of β-Cyclodextrin based polymeric adsorbent (PCD-VI) with an expanded “pocket” structure was created, and it exhibited excellent adsorption capacities for different kinds of pollutants, cationic rhodamine B (RB), anionic Congo red (CR) and cadmium ion (Cd(II)) in a mono-component solution. Since the “pocket effect” (composed of cavity inclusion and π-π interactions), electrostatic attraction and coordination were the dominant mechanisms for RB , CR and Cd(II) adsorption, respectively, competitive adsorption was effectively avoided in the simultaneous adsorption process. RB and Cd(II) exhibited a synergistic effect in the RB-Cd(II) binary solution; the coexisting Cd(II) showed a negligible effect on CR adsorption at lower CR concentrations (≤400 mg L −1 ), while the removal of Cd(II) was prominently promoted by the coexisting CR in the CR-Cd(II) binary system. More importantly, RB and Cd(II) could be recovered separately, and PCD-VI could be recycled without a serious decline in performance even after five sequential adsorption-desorption cycles in the RB-Cd(II) binary system. Our studies suggest promising strategies for fabrication and application of advanced adsorption materials in water pollution remediation.
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ANALYST
·
2013
·Vol. 138
·期 7
·2051-2056
·
IF 3.969
Qian Han,Yonghua Wang,Yihan Huang,Liju Guo,Yingzi Fu
A chiral interface has been designed for specific recognition of carboxylic acids using multilayer architectures of β-cyclodextrin (β-CD) and methylene blue/reduce-graphene (MB@rGO) on glassy carbon electrodes. The advantages of β-CD as a chiral selector and MB@rGO composite as an electrochemical indicator were perfectly presented in this novel interface. It displayed good redox signal for sensing chiral target with high sensitivity and conductivity. Enormous signal differences were obtained after adsorption of target L isomer, due to strong blocking of the electron transfer process of methylene blue. Meanwhile mandelic acid was found to be the best chiral guest and obtained more effective chiral recognition.
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RSC Advances
·
2014
·Vol. 4
·期 97
·54268-54281
·
IF 3.708
Yinwen Li,Huilong Guo,Jian Zheng,Jianqun Gan,Yan Zhang,Xiaoxiao Guan,Kun Wu,Mangeng Lu
Novel macromolecular star polymers with triazole and cyclodextrin (CD) segments as branch points and poly(oligo(ethylene glycol)methacrylate) (POEGMAs) as dense hydrophilic branches were synthesized via a combination of azide–alkyne click chemistry and atom transfer radical polymerization (ATRP). Firstly, a tetrafunctional linking agent (PETP) was prepared by the reaction of pentaerythritol (PE) and propargyl bromide, and then a four arm β-CD terminated star polymer (PE-CD) was obtained through the click chemistry reaction. Finally, thermally-responsive star polymers (PE-CD–POEGMAs) with PE as the central core, triazole and CD segments as branch points, and POEGMAs as side branches were synthesized by the ATRP of MEO2MA and OEGMA using PE-CD terminated with bromines as macroinitiators. A study on the thermoresponsivity and morphology of PE-CD–POEGMAs indicated that polymeric nano-aggregates existed as multimolecular micelles and behaved with tunable thermosensitivity, which were driven by the strong hydrophobic–hydrophilic interactions in the inner core and outer shell. The encapsulation capacities towards multi-guest molecules were investigated and the results indicated that water soluble guests could be encapsulated by PE-CD–POEGMAs, and the guest encapsulation capacities were derived from the special star molecular structure properties of PE-CD–POEGMAs and the synergistic encapsulation phenomenon of different guest molecules. This unique amphiphilic star polymer illustrated the potential applications in supramolecular science, drug delivery and other nanotechnology applications.
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危险品化学品经营许可证（带存储）