JOURNAL OF ASIA-PACIFIC ENTOMOLOGY
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2017
·
IF 1.046
Yunhua Zhang,Jinyun Ji,Xiao Zhao,Ruoheng Jin,Jianhong Li,Hu Wan
A previous study demonstrated that a β- N -acetyl- d -hexosaminidase ( NlHex4 ) from the brown planthopper could serve as a new potential target for biopesticides due to its requirement for molting, and lethal phenotypes were observed via RNA interference . However, the enzymatic properties of NlHex4 remain unclear. In the present study, NlHex4 was expressed, purified and characterized. Recombinant NlHex4 was functionally expressed in baculovirus-infected insect cells and purified with a molecular weight of approximately 70 kDa. Recombinant NlHex4 had an optimal pH and temperature of 6.0 and 60 °C, respectively. Moreover, recombinant NlHex4 exhibited thermal stability at 50 °C for at least 1 h. Furthermore, the activity of recombinant NlHex4 was inhibited by the metal ions Fe 2 + and Fe 3 + and the serine protease inhibitor phenylmethanesulfonyl fluoride. These results reveal the enzymatic properties of NlHex4 and provide a basis for future investigation of the interaction between HEX and chitin oligosaccharide .
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JOURNAL OF CHROMATOGRAPHY A
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2017
·
IF 3.981
Najing Fu,Liteng Li,Xiao Liu,Nian Fu,Chenchen Zhang,Liandong Hu,Donghao Li,Baokun Tang,Tao Zhu
Typically, a target compound is selected as a template for a molecularly imprinted polymer (MIP); however, some target compounds are not suitable as templates because of their poor solubility. Using the tailoring properties of a deep eutectic solvent (DES), the insoluble target compound caffeic acid was transformed into a ternary choline chloride–caffeic acid–ethylene glycol (ChCl–CA–EG) DES, which was then employed as a template to prepare MIPs. The ternary DES-based MIPs were characterized by Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy, and atomic force microscopy. The effects of time, temperature, ionic strength, and pH on the recognition processes for four polyphenols (caffeic acid, protocatechuic acid, catechin, and epicatechin) by 13 ChCl–CA–EG ternary DES-based MIPs was investigated using high-performance liquid chromatography. The recognition specificity of the MIPs for CA was significantly better than that for the other polyphenols, and the MIPs exhibited obvious characteristics of chromatographic packing materials. In addition, the recognition processes mainly followed a second-order kinetics model and the Freundlich isotherm model, which together indicated that the MIPs mainly recognized the polyphenols by chemical interactions including ion exchange, electron exchange, and new bond formation. Furthermore, the specific recognition ability of the MIPs for polyphenols, which was better than those of C 18 , C 8 , or non-molecularly imprinted polymer adsorbents, was successfully applied to the recognition of polyphenols in a Radix asteris sample. The transformation of an insoluble target compound in a polymeric DES for MIP preparation and recognition is a novel and feasible strategy suitable for use in further MIP research developments.
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MATERIALS & DESIGN
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2016
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IF 3.997
Xinjian Cheng,Yun Yu,Yiru Jia,Lian Duan
Three small molecular boron dipyrromethene (BODIPY) derivatives (B3a, B3b and B3c) were well-designed and synthesized at first, and then were incorporated into polyurethane to obtain macromolecular fluorescent sensors. These small molecular BODIPY derivatives exhibited high sensitivity and selectivity to Hg 2 + , Cr 3 + and Fe 3 + ions. The colors of these chemicals changed rapidly upon the addition of Hg 2 + , Cr 3 + and Fe 3 + ions. In addition, their fluorescence peaks shifted and was enhanced as well. B3a, B3b and B3c still remained the sensing properties when being introduced to polyurethane (PU). The functionalized PU films not only showed color change and fluorescence shift for detecting Hg 2 + , Cr 3 + and Fe 3 + ions as their small molecular counterparts, but also triggered a new emission peak in 500–600 nm. Besides, the functionalized PU film (PU-B3a as a sample) could absorb Hg 2 + ions more than 84 mg/g in unit time and volume. It suggested that as long as the structure of the small molecular sensor was remained, the fluorescent ability remained even it is introduced to the macromolecular chains. In addition, Glass transition temperature (T g ) of the PU films changed when B3a, B3b and B3c were introduced.
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MATERIALS CHEMISTRY AND PHYSICS
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2017
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IF 2.084
Yiru Jia,Yi Pan,Haiying Wang,Rong Chen,Hua Wang,Xinjian Cheng
A fluorescent monomer of boron dipyrromethene (BODIPY) derivative ( 9AnPD) is designed and synthesized at first, and then it is introduced into polyurethane to obtain polymeric chemosensor with dangling fluorescent side groups. The monomer chemosensor 9AnPD exhibits highly selective properties to Hg 2+ ion in a wide pH range. The color of the monomer changed rapidly upon the addition of Hg 2+ ion. The fluorescence peak shifted and is enhanced about 4-flod. In addition, the monomer chemosensor reaches the detection limit of Hg 2+ is as low as 5 × 10 −6 m. When the fluorescent monomer is introduced to polymers, the sensing properties of the monomer chemosensor 9AnPD still remained. The polymer chemosensors not only exhibit fluorescence shift and color change for identifying Hg 2+ ion as its monomer chemosensor, but also improve the efficiency of detection. The detection limit of polymer chemosensor could reach 5 × 10 −7 m , and the fluorescence enhanced about 6-flod. The glass transition temperature (T g ) of the fluorescent PU is increased with the introduction of 9AnPD . However, it is about 60 °C, and will not lead to any adverse effect for the process. The molecular weights of PUs are lower than which without 9AnPD , but still of the macromolecular level.
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NANOTECHNOLOGY
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2017
·Vol. 28
·期 16
·165502
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IF 3.44
Pengfei Lv,Yixin Yao,Huimin Zhou,Jin Zhang,Zengyuan Pang,Kelong Ao,Yibing Cai,Qufu Wei
Herein, we report an eco-friendly and simple fluorescent nitrogen-doped carbon quantum dot (N-CQD) biosensor which was synthesized via a hydrothermal method using erhanediamine (EDA) and citric acid (CA) as precursors. The surface functionalization of N-CQDs exhibited a bright blue emission under the excitation wavelength of 350 nm. The obtained N-CQDs were characterized by atomic force microscopy (AFM), Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and transmission electron microscopy. It was found that the surface of the CQDs was successfully functionalized. After that, as-prepared N-CQDs were further applied in Fe(III) detection. Spectroscopic data indicated that fluorescent carbon-based nanomaterials displayed a sensitive response to Fe3+ in the range of 0.5–1000 μM as a fluorescence sensor in real environmental samples. Furthermore, the results also showed that a novel N-CQD nanomaterial could be employed as an ideal fluorescent Fe(III) probe.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2016
·Vol. 133
·期 35
·
IF 1.866
Jin Liu,Xiaohui Tian,Jinyu Sun,Yizhong Yuan
Poly(methyl methacrylate- co -butyl methacrylate) [P(MMA- co -BMA)] nanoparticles were synthesized via emulsion polymerization, and incorporated into natural rubber (NR) by latex compounding. Monodispersed, core-shell P(MMA- co -BMA)/casein nanoparticles (abbreviated as PMBMA-CA) were produced with casein (CA) as surfactant. The chemical structure of P(MMA- co -BMA) copolymers were confirmed by 1 H-NMR and FTIR analyses. Transmission electron microscopy demonstrated the core–shell structure of PMBMA-CA, and PMBMA-CA homogenously distributed around NR particles, indicating the interaction between PMBMA-CA and NR. As a result, the tensile strength and modulus of NR/PMBMA-CA films were significantly enhanced. The tensile strength was increased by 100% with 10% copolymer addition, when the molar ratio of MMA:BMA was 8:2. In addition, scanning electron microscopy and atomic force microscopy results presented that the NR/PMBMA-CA films exhibited smooth surfaces with low roughness, and PMBMA-CA was compatible with NR. FTIR-ATR analyses also suggested fewer PMBMA-CA nanoparticles migrated out of NR. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43843.
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JOURNAL OF ETHNOPHARMACOLOGY
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2016
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IF 3.055
Lingyu Zhou,Tianyu Zhang,Bin Lu,Zengyang Yu,Xiyu Mei,Palida Abulizi,Lili Ji
Ethnopharmacological relevance Lonicerae Japonicae Flos (Jin-Yin-Hua) is a well-known traditional Chinese medicine used for clearing away heat and toxic material. Aim of the study This study aims to observe the attenuation of aqueous extract of Lonicerae Japonicae Flos (FL) against streptozotocin (STZ)-induced diabetic retinopathy (DR) and its engaged mechanism. Materials and methods STZ-induced proliferative DR (PDR) for 5 month in C57BL/6 mice was used in this study. Retinal vessels were observed by immunofluorescence staining with cluster of differentiation 31 (CD31) and histopathological evaluation. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum vascular endothelial growth factor (VEGF) content. Cell proliferation was detected by 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide (MTT) assay in choroid-retinal endothelial RF/6A cells. VEGF-induced tube formation in RF/6A cells was observed. The contents of chlorogenic acid (CGA), caffeic acid (CA), and luteolin in FL were detected by high-performance liquid chromatography (HPLC). Results Histopathological evaluation demonstrated that retinal vessels were increased in STZ-induced PDR mice, whereas FL decreased such increase. The results of CD31 staining also showed that FL decreased the increased number of retinal vessels in STZ-induced PDR mice. In addition, FL reduced the increased serum VEGF content in STZ-induced PDR mice. FL reduced VEGF-induced RF/6A cell proliferation in the concentration-dependent manner, but had no obvious effect on RF/6A cell viability without VEGF stimulation. VEGF-induced tube formation in RF/6A cells was inhibited by different concentrations of FL. CGA, CA and luteolin all inhibited VEGF-induced tube formation in RF/6A cells, and the lowest effective concentration of CGA and CA was both 0.625 μM, but of luteolin was 5 μM. Furthermore, the results of HPLC demonstrated that the amount of CGA was the highest in FL. Conclusions FL ameliorates STZ-induced PDR by inhibiting retinal angiogenesis. Phenolic acid CGA is the main compound contributing to the inhibition of FL on retinal angiogenesis.
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ACS Applied Materials & Interfaces
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2017
·
IF 7.504
Shuhua Li,Shixin Zhou,Yunchao Li,Xiaohong Li,Jia Zhu,Louzhen Fan,Shihe Yang
The IR780 iodide (IR780) is recognized as an effective theranostic agent for simultaneous near-infrared fluorescence imaging and photothermal therapy (PTT). However, the rigid chloro-cyclohexenyl ring makes IR780 insoluble in almost all pharmaceutically acceptable solvents, which inevitably limits its clinical application. We report folic acid (FA)-functionalized graphene quantum dots (GQDs-FA) containing a large and intact sp2 domain with carboxyl groups around the edge. Such GQDs-FA possess exceptionally high loading capacity for IR780 via strong π–π stacking interactions, and the water solubility of IR780 is improved by over 2400-fold after loading onto GQDs-FA (IR780/GQDs-FA). IR780/GQDs-FA with an improved photostability, an enhanced tumor-targeting ability, and a high photothermal conversion efficiency of 87.9% were capable of producing sufficient hyperthermia to effectively kill cancer cells and completely eradicate tumors upon 808 nm laser irradiation. The present IR780/GQDs-FA may open up great opportunities for the effective PTT to treat cancer.
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JOURNAL OF SEPARATION SCIENCE
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2017
·Vol. 40
·期 8
·1651-1659
·
IF 2.557
Tong Wang,Hai-Long Wu,Li-Xia Xie,Li Zhu,Zhi Liu,Xiao-Dong Sun,Rong Xiao,Ru-Qin Yu
In this work, a smart chemometrics-enhanced strategy, high-performance liquid chromatography, and diode array detection coupled with second-order calibration method based on alternating trilinear decomposition algorithm was proposed to simultaneously quantify 12 polyphenols in different kinds of apple peel and pulp samples. The proposed strategy proved to be a powerful tool to solve the problems of coelution, unknown interferences, and chromatographic shifts in the process of high-performance liquid chromatography analysis, making it possible for the determination of 12 polyphenols in complex apple matrices within 10 min under simple conditions of elution. The average recoveries with standard deviations, and figures of merit including sensitivity, selectivity, limit of detection, and limit of quantitation were calculated to validate the accuracy of the proposed method. Compared to the quantitative analysis results from the classic high-performance liquid chromatography method, the statistical and graphical analysis showed that our proposed strategy obtained more reliable results. All results indicated that our proposed method used in the quantitative analysis of apple polyphenols was an accurate, fast, universal, simple, and green one, and it was expected to be developed as an attractive alternative method for simultaneous determination of multitargeted analytes in complex matrices.
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JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Xiuping He,Jianlei Chen,Jiangtao Wang,Liju Tan
Due to the high cost of domoic acid (DA), different carboxylic acid compounds including indole-3-acetic acid (IAA), pyrrole-2-formic acid (PFA), pyridine-2,3-dicarboxylic anhydride (PDA), trimesitinic acid (TA) and citric acid (CA) were investigated as dummy templates for the molecularly imprinted solid-phase extraction (MISPE) for selective isolation and pre-concentration of an amnesic shellfish poison (ASP), DA. The highest binding amount of the polymers towards DA was obtained when CA was used as dummy template owing to its high hydrophilicity. In addition, the “four-point” recognition site constructed by three COOH groups and a OH group in CA was also speculated to be the reason for the high binding amount of CA-MIPs and the rebinding of DA can be depend on the three COOH groups and a NH group with conformational change in the recognition process. Finally, the CA-MISPE column was chosen for DA isolation and pre-concentration and effective result was obtained with recoveries higher than 90% and relative standard deviation (RSD) less than 5% (n = 3). This new polymer can be effectively applied to the monitoring and predicting the existence of trace DA.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2017
·
IF 3.359
Yunchang Fan,Xiaojing Li,Ping Shen,Hongxin Cai,Feifei Li,Yongxiang Wang
In this work, imidazolium-based ionic liquids (ILs) were used to extract hydroxycinnamic acids from water. Experimental results indicated that the ILs with CF 3 SO 3 − anion had higher extraction ability for hydroxycinnamic acids because of the stronger hydrogen-bonding strength of CF 3 SO 3 − . The combination of cation and anion, both of which have strong hydrogen-bonding ability, generates a hydrogen-bonding-functionalized IL, 1-butyl-3-(11-hydroxyundecyl)imidazolium trifluoromethanesulfonate ([C 4 C 11 OHim]CF 3 SO 3 ) which has strongest hydrogen-bonding ability and strongest extraction ability for hydroxycinnamic acids. Thermodynamic analysis suggested that hydrogen-bonding interaction was the major driving force; meanwhile, the influence of hydrophobic interaction and steric hindrance between ILs and hydroxycinnamic acids should be considered when interpreting the extraction behavior of ILs. The extraction ability of the ILs was strongly influenced by the aqueous pH; it decreased with increasing pH in the range of pH > p K a (dissociation constant). The stronger extraction ability of ILs at lower pH values could be interpreted by the strong hydrogen-bonding interaction between ILs and the undissociated hydroxyl and carboxyl groups of the hydroxycinnamic acids. Preliminary results suggested that [C 4 C 11 OHim]CF 3 SO 3 may be applied to the process of the recovery of hydroxycinnamic acids from aqueous media.
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RSC Advances
·
2016
·Vol. 6
·期 83
·79781-79791
·
IF 3.289
Yanmei Luo,Junhui Ran,Rong Chen,Xinjian Cheng
Porous organic polymers (POPs) were prepared via two-step reactions. In the first step, dialdehyde compounds were synthesized using the Suzuki–Miyaura coupling reaction, and in the second step, the dialdehyde compounds reacted with hydrazine hydrate to form polymers using Schiff’s base formation reactions. These POPs are nanosheet-layer structured, crystalline and fluorescent. They were studied using FTIR, fluorescence spectra, UV-Vis, SEM, TEM, XRD, DSC, and TGA. It was found that the pore parameters, such as specific surface areas and pore diameters, of the POPs could be adjusted by changing the reaction time and temperature. The specific surface areas increased with the increasing of reaction time and temperature. The maximum specific surface area could reach 715.6 m2 g−1. Furthermore, the POPs could detect and remove Pd(II) ions and organic dyes. When in contact with Pd(II) ions, the fluorescence of the POPs was quenched, and the POPs could absorb Pd(II) ions as well. The maximum absorption capacity for Pd(II) ions could reach 20.6 mg g−1 within 5 min. Meanwhile, the POPs could absorb two model dyes, rhodamine B (RhB) and methylene blue (MB), with high efficiency within 5 min.
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