TheScientificWorldJOURNAL
·
2014
·
IF 1.219
Fujia Chen,Xiaohua Long,Zhaopu Liu,Hongbo Shao,Ling Liu
Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs) were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid) by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW), 4,5-dicaffeoylquinic acid (5.633 mg/g DW), and 3,5-dicaffeoylquinic acid (4.900 mg/g DW) were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu). Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW) than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals.
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高影响因子
HIGH PERFORMANCE POLYMERS
·
2015
·
IF 1.286
Qiuxiang Wu,Zhizhou Yang,Jinshui Yao,Donghong Yu
Five new optically active poly(amide–imide)s (PAIs) (PAI3a–PAI3e) were synthesized through the direct polycondensation reaction between chiral N,N′-(pyromellitoyl)-bis-l-amino acids and 4,4′-diaminodiphenyl ether. The resulted polymers were fully characterized by means of Fourier transform infrared (FTIR) and proton nuclear magnetic resonance spectroscopy, elemental analysis, inherent viscosity measurement, solubility tests, specific rotation, and thermogravimetric analysis (TGA). The biodegradation studies of the PAIs were performed in soil and in phosphate buffer solution. The surface morphology and hydrophobicity of the biodegraded PAI films were investigated. FTIR spectra showed structural changes on PAI powders being treated in phosphate buffer solution. The TGA data showed that the thermal stability of PAI powders decreased with the degradation time. The collected degradation products were soluble in water and had absorption in ultraviolet and visible light region. Possible biodegradation mechanism of amino acid-based PAIs was explored.
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TALANTA
·
2015
·
IF 3.545
Mengzhen Dai,Ting Huang,Long Chao,Qingji Xie,Yueming Tan,Chao Chen,Wenhua Meng
Horseradish peroxidase (HRP)-catalyzed polymerization of l -DOPA (vs. dopamine) in the presence of H 2 O 2 (and uricase (UOx)) was exploited to immobilize mono-/bi-enzymes for hydroquinone-mediated amperometric biosensing of H 2 O 2 and uric acid (UA). The relevant polymeric biocomposites (PBCs) were prepared in phosphate buffer solution containing HRP and l -DOPA (or plus UOx) after adding H 2 O 2 . The mono-/bi-enzyme amperometric biosensors were prepared simply by casting some of the PBCs on Au-plated Au (Au plate /Au) electrodes, followed by coating with an outer-layer chitosan (CS) film for each. UV–vis spectrophotometry , scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy were used for film characterization and/or process monitoring. The HRP immobilized by enzyme catalysis well preserved its bioactivity, as confirmed by UV–vis spectrophotometry . Under optimized conditions, the monoenzyme CS/HRP-poly( l -DOPA) (PD)/Au plate /Au electrode potentiostated at −0.1 V responded linearly to H 2 O 2 concentration from 0.001 to 1.25 mM with a sensitivity of 700 μA mM −1 cm −2 and a limit of detection (LOD) of 0.1 μM, and the bienzyme CS/UOx–HRP–PD/Au plate /Au electrode at −0.1 V responded linearly to UA concentration from 0.001 to 0.4 mM with a sensitivity of 349 μA mM −1 cm −2 and a LOD of 0.1 μM. The mono-/bi-enzyme biosensors based on biosynthesized PD performed better than many reported analogues and those based on similarly biosynthesized polydopamine.
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高影响因子
ANALYST
·
2015
·Vol. 140
·期 23
·7974-7983
·
IF 4.107
Wenhua Qiao,Lu Wang,Baoxian Ye,Gaiping Li,Jianjun Li
A new and sensitive voltammetric sensor for palmatine, based on an electrochemically reduced L-methionine functionalized graphene oxide modified glassy carbon electrode (L-Met-ERGO/GCE), is reported. The electrochemical characteristics of palmatine at the proposed sensor were studied systematically and some dynamic parameters were calculated for the first time. A reasonable reaction mechanism for palmatine on the L-Met-ERGO/GCE electrode was proposed and discussed, and this could be a reference for the pharmacological action of palmatine in clinical study. Under optimized conditions, the peak current had a linear relationship with palmatine concentration in the range of 1 × 10−7 to 5 × 10−5 mol L−1 with a detection limit of 6 × 10−8 mol L−1. Additionally, the proposed method was also used to detect palmatine in human urine samples, medicinal tablets and the Chinese herb Fibraurea recisa Pierre with satisfactory results.
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TALANTA
·
2015
·
IF 3.545
Wenjing Wang,Lu Wang,Lina Zou,Gaiping Li,Baoxian Ye
A novel voltammetric sensor was constructed by simple dripping single-walled carbon nanotubes (SWCNTs) on to the glass carbon electrode (GCE) firstly and electro-polymerizing l -Citrulline film subsequently. The resulting poly( l -Citrulline)/SWCNTs/GCE showed a significant voltammetric response to picroside II due to the synergistic effect of SWCNTs and poly( l -Citrulline) film. The first electroanalytical method of picroside II was proposed with detection linear range from 8.0×10 −8 to 5.0×10 −6 mol L −1 and a detection limit of 3×10 −8 mol L −1 .The high sensitivity, selectivity and long-term stability made the sensor suitable for the determination of picroside II. Moreover, based on the systematically investigation and some kinetics parameters calculated in the experimentation, the reaction mechanism of picroside II at the poly( l -Citrulline)/SWCNTs modified GCE was obtained reliably. Lastly, the proposed sensor was used for the determination of picroside II in real sample with satisfactory results. This work promoted the potential applications of amino acid materials and SWCNTs in electro-chemical sensors.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Yongling Ding,Shirley Z. Shen,Huadong Sun,Kangning Sun,Futian Liu
l -Glutathione capped (GSH) ZnSe quantum dots (QDs) have been synthesized as a fluorescence ions probes for ultrasensitive Cu (II) detection. These QDs surface decoration with glutathione shells can be directly applied without previous treatment. The fluorescence quenching of the GSH-capped-ZnSe QDs depends on the concentration, pH values and reaction time of the Cu 2+ solution. Based on the effective electron transfer from GSH to Cu 2+ and the surface ligand stripping occurs onto the surface of ZnSe QDs, it results in the reduction of Cu 2+ to Cu + and increment of surface defection on the surface of the QDs. Under the optimum conditions, the detection limit of Cu 2+ is 2 × 10 −10 mol L −1 . Meanwhile, the effect of foreign ions displays a low interference response in the detecting of Cu 2+ ions. Moreover, based on the invariable absorption peak position and curtate luminescence lifetime of ZnSe QDs, the quenching process has also been confirmed to be a dynamic quenching procedure. With regard to the practical feasibility test of the fluorescent probe , a relative lower standard deviation (RSD) (≤3%) and a high recovery rate demonstrate that the proposed simple method is sensitive, accurate and reliable.
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JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2016
·Vol. 54
·期 5
·706-712
·
IF 1.32
Zhang Meiling,Zhao Cui,Liang Xianrui,Ying Yin,Han Bing,Yang Bo,Jiang Cheng
A fingerprinting approach was developed by means of ultra high-performance liquid chromatography with photodiode array detector for the quality control of Desmodium triquetrum L., an herbal medicine widely used for clinical purposes. Ten batches of raw material samples of D. triquetrum were collected from different regions of China. All UPLC analyses were carried out on a Waters ACQUITY UPLC BEH shield RP18 column (2.1 × 50 mm, 1.7 µm particle size) at 60°C, with a gradient mobile phase composed of 0.1% aqueous formic acid and acetonitrile at a flow rate of 0.45 mL/min. The method validation results demonstrated the developed method possessing desirable reproducibility, efficiency, and allowing fingerprint analysis in one chromatographic run within 13 min. The quality assessment was achieved by using chemometrics methods including similarity analysis, hierarchical clustering analysis and principal component analysis. The developed method can be used for further quality control of D. triquetrum.
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JOURNAL OF MOLECULAR RECOGNITION
·
2017
·Vol. 31
·期 1
·e2657
·
IF 2.175
Jie Li,Yang Zhang,Yanmei Chen,Xuefang Shang,Tongyu Ti,Hongli Chen,Tianyun Wang,Jinlian Zhang,Xiufang Xu
Inspired by biological related parts, Schiff base derivatives and functional groups of chemical modification can provide efficient detection method of amino acids. Therefore, we have designed and prepared 4 compounds based on Schiff base derivatives involving ─NO 2 , ─OH, and naphthyl group. Results indicated that compound 4 containing 2 nitro groups showed strong sensitivity and high selectivity for arginine (Arg) among normal 18 kinds of standard amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, and cysteine). Theoretical investigation also approved the strong binding ability of compound 4 for Arg. In addition, compound 4 displayed high combining ability of Arg and low cytotoxicity of MCF-7 cell in the 0 to 150 μg mL −1 of concentration range; it can be used for Arg in vivo detection of fluorescent probe.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Ze Zhang,Xiaowei Zhao,Xiaojun Jv,Hongguang Lu,Lianjie Zhu
In this work, l-tyrosine modified magnetite nanoparticles (TMNPs) are prepared by a facile ultrasound assisted solution route and used for adsorption of both methylene blue (MB) and methyl orange (MO), the typical cationic and anionic dye, respectively. The as-prepared magnetic adsorbents TMNPs are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FT-IR), and vibrating sample magnetometer (VSM). The influential factors (solution pH and contact time) to the adsorption of the dyes by the magnetite nanoparticles are investigated. The adsorption kinetics illustrates the suitability of employing the pseudo-second-order kinetic model. Three isothermal adsorption models (Langmuir, Freundlich, and Temkin) are tested to investigate the adsorption properties. The results show that the adsorption behavior fits quite well with the Langmuir model. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) are estimated and implied that the adsorption process is spontaneous and exothermic in nature. Moreover, TMNPs can be successfully regenerated and reused for at least five cycles without compromising the adsorption capacity, which is greatly reduced the using cost.
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CHEMISTRY & BIODIVERSITY
·
2017
·Vol. 14
·期 9
·e1700114
·
IF 1.44
Lu Wang,Yanan Wu,Tao Huang,Kan Shi,Zhenqiang Wu
Hydrodistilled essential oils (EO) of Psidium guajava L. leaves from different regions in China were analyzed by GC and GC/MS. The samples from Guangdong Province displayed high EO yields (0.61 – 0.75%, v / w ). A total of 50 components, representing over 98.00% of the EOs, were identified and semi-quantitatived. The major constituents of EOs included β -caryophyllene (17.17 – 31.38%), γ -gurjunene (9.17 – 15.22%), τ -cadinol (1.35 – 10.02%) and calamenene (2.13 – 7.80%). The terpenoids in all sample oils were dominated by sesquiterpenes hydrocarbons (70.18 – 84.35%), followed by oxygenated sesquiterpenes (9.89 – 22.19%). The similarities and differences among EOs from different samples were evaluated by hierarchical cluster analysis and principal component analysis methods. The IC 50 values of EOs from different regions were between 18.52 – 33.72 mg/ml (DPPH) and 13.12 – 25.15 mg/ml (ABTS + ). The FRAP value of EO from Guangdong Province was 7.34 – 9.13 mmol Vc/g DM, while the FRAP value of EO from Taiwan Province was 2.29 – 2.36 mmol Vc/g DM. The antimicrobial tests revealed that EO had a higher antimicrobial activity against all Gram -positive bacteria and two fungi. Moreover, EO from P . guajava leaves of Guangdong Province showed the highest antimicrobial activity. These properties can be considered in the design of industrial products and for further application in the food, pharmaceutical and cosmetic industries. Graphical
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
X. Jia,Y.H. Zhao,T. Liu,Y.H. He
Short-term exposure to elevated CO 2 increases cadmium (Cd) uptake in some plant species (wheat, poplars, and willows), which triggers an increase in antioxidative system activity to deal with additional reactive oxygen species that are generated. Here, we examined leaf defenses in Robinia pseudoacacia L. seedlings exposed to elevated CO 2 + Cd for 3 years. Three years of elevated CO 2 decreased Cd uptake into leaves and the Cd content in soils and increased the pH of rhizosphere soil relative to ambient CO 2 . In plants exposed to Cd stress , leaf chlorophyll content was greater under elevated CO 2 than under ambient CO 2 . Superoxide dismutase, peroxidase, and catalase activity increased, glutathione content increased, and malondialdehyde and phytochelatins contents decreased under elevated CO 2 + Cd relative to Cd alone. Proline, soluble sugars, flavonoids, saponins, and phenolic acids contents were greater under elevated CO 2 + Cd than under Cd alone, and condensed tannin content was lower. Overall, long-term elevation of CO 2 enhanced the leaf defense system of R. pseudoacacia exposed to Cd by stimulating antioxidant enzyme activity , osmotic adjustment, and the production of glutathione, flavonoids and phenolic acids. Future research should focus on understanding the mechanisms involved in the decrease in Cd uptake into leaves and Cd content in soils and the increase in rhizosphere soil pH under long-term exposure to elevated CO 2 .
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 10
·5807-5821
·
IF 2.599
Xiao Jianliang,Lv Weiyang,Xie Zhou,Song Yihu,Zheng Qiang
It is a challenge to develop broad-spectrum, high-efficiency, easy-recyclable adsorbents for the removal of water contaminants. Herein, l -cysteine-reduced graphene oxide/poly(vinyl alcohol) (CRG/PVA) ultralight aerogels with good mechanical strength and reusability are prepared via a direct sol–aerogel transition strategy by freeze drying. At optimized composition, the aerogel shows high adsorption efficiency toward both cationic and anionic dyes, overcoming the defect of many traditional adsorbents that usually can only remove one type of organic dyes. The adsorption is proved to involve in π – π interaction between CRG and dyes, endowing the aerogel with universality in adsorbing a wide range of conjugated dyes. Moreover, a remarkable synergetic effect is observed for removal of two oppositely charged dyes from aqueous system, yielding exceptionally high total adsorption capacities surpassing all known adsorbents examined for removing binary dyes. Thus, the CRG/PVA aerogel demonstrates great potential for usage as reusable, high-efficiency, and broad-spectrum adsorbent in water treatment.
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