Chemistry Central Journal
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2014
·Vol. 8
·期 1
·1-10
·
IF 1.663
Chen Feng,Li Hai-Long,Tan Yin-Feng,Guan Wei-Wei,Li Yong-Hui,Zhang Jun-Qing
Background Yakuchinone A has a plethora of beneficial biological effects. However, the pharmacokinetic (PK) data of yakuchinone A still remain unknown so far. Furthermore, the quantification of yakuchinone A in biological samples has not been reported in the literature. Therefore, in the present study we aimed to develop a new method for the fast, efficient and accurate assessment of yakuchinone A concentration in plasma, as a means for facilitating the PK evaluation of yakuchinone A.Results A liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the determination of yakuchinone A in rat plasma. Mass spectrometric and chromatographic conditions were optimized. Plasma samples were pretreated by protein precipitation with methanol. LC separation was performed on a Phenomenex Luna C18 column with gradient elution using a mobile phase consisting of methanol–water containing 0.5 mM formic acid (HCOOH) at a flow rate of 0.28 mL/min. ESI-MS spectra were acquired in positive ion multiple reaction monitoring mode (MRM). The precursor-to-product ion pairs used for MRM of yakuchinone A and yakuchinone B were m/z 313.1 → 137.0 and 311.2 → 117.1, respectively. Low concentration of HCOOH reduced the ion suppression caused by matrix components and clearly improved the analytical sensitivity. Yakuchinone A showed good linearity over a wide concentration range (r > 0.99). The accuracy, precision, stability and linearity were found to be within the acceptable criteria. This new method was successfully applied to analyze the rat plasma concentration of parent yakuchinone A after a single oral administration of SuoQuan capsules. Low systemic exposure to parent yakuchinone A was observed.Conclusion The proposed method is sensitive and reliable. It is hoped that this new method will prove useful for the future PK studies.
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FIBERS AND POLYMERS
·
2014
·Vol. 15
·期 1
·145-152
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IF 1.113
Liu Hongyi,Zhang Yong,Yao Juming
Recently, cellulose-based superabsorbent has attracted attention as a promising material in many fields because of its rich sources and outstanding properties of biodegradability and biocompatibility. This study examines the potential application of a novel flax yarn waste-g-poly(acrylic acid-co-acrylamide) (FYW/PAA) superabsorbent in the absorbent core layer of sanitary napkins. Acrylic acid (AA) and acrylamide (AM) were grafted onto the pretreated flax yarn waste (PFYW) by free-radical graft copolymerization in homogeneous aqueous solution. The synthesis conditions of the FYW/PAA superabsorbent and its application performance for sanitary napkin were investigated. The results showed that, under the optimal synthesis conditions, the water absorbency of the prepared FYW/PAA reached 787.6 g/g in deionized water, 109.5 g/g in 0.9 wt% NaCl solution and 206.5 g/g in artificial blood solution. The composited absorbent core layer containing the FYW/PAA achieved the similar artificial blood solution absorbency of 192.6 g/g and retention of 83.9 wt% to those of the marketed sanitary napkin products. Meanwhile, a weight residue of 53.6 wt% was attained for the FYW/PAA after being buried in soil for 90 d.
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Chemistry Central Journal
·
2014
·Vol. 8
·期 1
·1-7
·
IF 1.663
Luo Hui,Cai Yongqiang,Peng Zhijun,Liu Tao,Yang Shengjie
Background Hylocereus polyrhizus and Hylocereus undatus are two varieties of the commonly called pitaya fruits, and pitaya fruits have gained popularity in many countries all over the world. However, studies on chemical composition and the nutritional quality of pitaya flesh peel are limited.Results Extracts of pitaya (H. polyrhizus and H. undatus) peel were extracted by supercritical carbon dioxide extraction, and analyzed by gas chromatography–mass spectrometry analysis. Their cytotoxic and antioxidant activities were investigated. The main components of H. polyrhizus extract were β-amyrin (15.87%), α-amyrin (13.90%), octacosane (12.2%), γ-sitosterol (9.35%), octadecane (6.27%), 1-tetracosanol (5.19%), stigmast-4-en-3-one (4.65%), and campesterol (4.16%), whereas H. undatus were β-amyrin (23.39%), γ-sitosterol (19.32%), and octadecane (9.25%), heptacosane (5.52%), campesterol (5.27%), nonacosane (5.02%), and trichloroacetic acid, hexadecyl ester (5.21%). Both of the two extracts possessed good cytotoxic activities against PC3, Bcap-37, and MGC-803 cells (IC50 values ranging from 0.61 to 0.73 mg/mL), and the activities of their main components were also studied. Furthermore, these extracts also presented some radical scavenging activities, with IC50 values of 0.83 and 0.91 mg/mL, respectively.Conclusion This paper provides evidence for studying the chemical composition of supercritical carbon dioxide extracts of pitaya peel and their biological activity.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2014
·Vol. 21
·期 7
·5201-5210
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IF 2.757
Chen Xi,Yao Xiaoyan,Yu Chunna,Su Xiaomei,Shen Chaofeng,Chen Chen,Huang Ronglang,Xu Xinhua
Soil pollution by polychlorinated biphenyls (PCBs) arising from the crude disposal and recycling of electronic and electrical waste (e-waste) is a serious issue, and effective remediation technologies are urgently needed. Nanoscale zerovalent iron (nZVI) and bimetallic systems have been shown to promote successfully the destruction of halogenated organic compounds. In the present study, nZVI and Pd/Fe bimetallic nanoparticles synthesized by chemical deposition were used to remove 2,2′,4,4′,5,5′-hexachlorobiphenyl from deionized water, and then applied to PCBs contaminated soil collected from an e-waste recycling area. The results indicated that the hydrodechlorination of 2,2′,4,4′,5,5′-hexachlorobiphenyl by nZVI and Pd/Fe bimetallic nanoparticles followed pseudo-first-order kinetics and Pd loading was beneficial to the hydrodechlorination process. It was also found that the removal efficiencies of PCBs from soil achieved using Pd/Fe bimetallic nanoparticles were higher than that achieved using nZVI and that PCBs degradation might be affected by the soil properties. Finally, the potential challenges of nZVI application to in situ remediation were explored.
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Nanoscale Research Letters
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2013
·Vol. 8
·期 1
·1-8
·
IF 2.524
Zhou Na,Qiu Peiy,Wang Kan,Fu Hualin,Gao Guo,He Rong,Cui Daxiang
Water-soluble upconversion nanoparticles (UCNPs) were prepared by a one-pot procedure in a two-phase reacting system. Four kinds of surfactants were tested in the synthesis process as capping agent to tune size and morphology of nanocrystals. Nanoparticles (approximately 70 nm) and rods (400 nm and 2.5 μm) were synthesized, respectively. Then, Fourier transform infrared spectroscopy analysis confirmed the successful linking between UCNP surface and surfactant. Ionic liquids (ILs) and surfactants participated in synthesis process together, competing with each other to cap on UCNPs. ILs still led the competition of capping, while surfactants worked as cooperative assistants to develop functional surface. Further characterizations such as high-resolution transmission electron microscopy and X-ray diffraction indicated the changes in crystallization and phase transformation under the influence of surfactants. In addition, the growth mechanism of nanocrystals and upconversion fluorescence luminance was also investigated in detail. At last, the cytotoxicity of UCNPs was evaluated, which highly suggest that these surface-functionalized UCNPs are promising candidates for biomedical engineering.
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Food Analytical Methods
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2013
·Vol. 7
·期 7
·1458-1464
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IF 1.969
Ma Xinying,Chao Mingyong
A poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) for the electrochemical determination of kojic acid was developed. The polymerization mechanism of glutamic acid at the glassy carbon electrode, the electrocatalytic mechanism of the poly(glutamic acid) film toward kojic acid, and the electrochemical behavior of kojic acid at the PGA/GCE were investigated. The studies revealed that the oxidation of kojic acid at the PGA/GCE is greatly facilitated, which is attributed to the weakening of the bond energy between oxygen and hydrogen due to the formation of hydrogen bond between hydroxyl group in kojic acid and the nitrogen atom in poly(glutamic acid). The oxidation of kojic acid at the PGA/GCE is a one proton–one electron process. The catalytic effect was further used to determine kojic acid by cyclic voltammetry. The oxidation peak current shows a linear relationship with the concentrations of kojic acid in the range of 8.00 × 10 −6 to 6.60 × 10 −4 mol L −1 with the detection limit of 8.00 × 10 −7 mol L −1 . The modified electrode shows excellent sensitivity, selectivity, and stability and has been applied to detect kojic acid in a variety of food products with satisfactory results.
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FIBERS AND POLYMERS
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2013
·Vol. 14
·期 11
·1794-1802
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IF 0.912
Li Hui,Fu Shiyu,Peng Lincai
Depositing of TiO 2 nanoparticles on cellulose fiber surface has potential technological applications in the field of photocatalysis. With this motivation, multilayers composed of lignosulfonates (LS) and TiO 2 nanoparticles were constructed on cellulose fiber surface via layer-by-layer (LBL) self-assembly technique. X-ray photoelectron spectroscopy (XPS), zeta potential measurement and atomic force microscopy (AFM) were used to characterize the LS/TiO 2 multilayers on cellulose fiber surface. Moreover, the photocatalytic activities of modified cellulose fibers (decomposition of methyl orange and antibacterial test) were investigated. The decomposition efficiency of methyl orange for a (LS/TiO 2 ) 5 multilayer modified cellulose fibers was 74.7 % under 5 h UV irradiation. Photocatalytic decomposition efficiency of methyl orange by LS/TiO 2 multilayer modified cellulose fibers under the same UV irradiation time increased linearly with the number of bilayers. Antibacterial tests results revealed that the cellulose fibers modified with LS/TiO 2 multilayers exhibited excellent antibacterial activity against E.coil . The degree of E.coil growth inhibition for a (LS/TiO 2 ) 5 multilayer modified cellulose fiber reached as high as 93 %. In addition, the effect of LS/TiO 2 multilayers on properties of handsheets made from modified cellulose fibers was also considered. The air permeability of the handsheet prepared from fibers modified with TiO 2 /LS multilayers had 6.1–24.3 % higher compared with that of handsheet prepared from original fibers. The wetting properties measurement results demonstrated that the water contact angle of handsheet oscillated with the increasing number of layers depended on building block which was in the outermost layer.
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MICROCHIMICA ACTA
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2014
·Vol. 182
·期 3
·679-685
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IF 3.719
Xu Guiyun,Wang Wenting,Li Beibei,Luo Zhonglin,Luo Xiliang
An electrochemical dopamine sensor was developed by electrochemical modification of a carbon paste electrode with a biocomposite made from poly(3,4-ethylenedioxythiophene) (PEDOT) that was doped with double stranded or single stranded DNA. The resulting conducting biocomposite displays excellent electrocatalytic activity towards the oxidation of dopamine (DA) which is attributed to the presence of the DNA dopant. Under optimum conditions and at a working potential of 300 mV, the modified electrode is capable of detecting DA in the 0.25 to 66 μM concentration range. The detection limit is 74 nM. The sensor is not interfered by uric acid and ascorbic acid.
PEDOT biocomposites doped with dsDNA (left) and ssDNA (right) can be electrochemically prepared and used for the sensitive and selective detection of dopamine owing to their excellent catalytic activity towards dopamine oxidation.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2014
·Vol. 406
·期 28
·7213-7220
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IF 3.578
Gao Lin,Wang Jixiang,Li Xiuying,Yan Yongsheng,Li Chunxiang,Pan Jianming
In this study, we report here a general protocol for making core-shell magnetic Fe 3 O 4 /SiO 2 -MPS/MIPs (MPS = 3-(methacryloxyl) propyl trimethoxysilane, MIPs = molecularly imprinted polymers, Fe 3 O 4 /SiO 2 -MPS as core, MIPs as shell) via a surface molecular imprinting technique for optical detection of trace λ -cyhalothrin. The fluorescent molecularly imprinted polymer shell was first prepared by copolymerization of acrylamide with a small quantity of allyl fluorescein in the presence of λ -cyhalothrin to form recognition sites without doping. The magnetic Fe 3 O 4 /SiO 2 -MPS/MIPs exhibited paramagnetism, high fluorescence intensity, and highly selective recognition. Using fluorescence quenching as a detecting tool, Fe 3 O 4 /SiO 2 -MPS/MIPs were successfully applied to selectively and sensitively detect λ -cyhalothrin, and a linear relationship could be obtained covering a wide concentration range of 0–50 nM with a correlation coefficient of 0.9962 described by the Stern-Volmer equation. The experimental results of practical detection revealed that magnetic Fe 3 O 4 /SiO 2 -MPS/MIPs as an attractive recognition element was satisfactory for determination of trace λ -cyhalothrin in honey samples. This study, therefore, demonstrated the potential of MIPs for detection of λ -cyhalothrin in food.
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TRANSACTIONS OF TIANJIN UNIVERSITY
·
2014
·Vol. 20
·期 4
·273-281
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IF 0
Yuan Caideng,Zhao Xiaoming,Shao Liying,Tang Kehua
Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the properties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2014
·Vol. 118
·期 3
·1441-1449
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IF 2.206
Qiu Xiaolin,Lu Lixin,Zhang Zhixiong,Tang Guoyi,Song Guolin
This study focused on preparation and thermal properties of poly(stearyl methacrylate) shell (PSMA) microcapsules containing n -octadecane as a phase change material (PCM). Pentaerythritol triacrylate (PETA) and divinylbenzene (DVB) were employed as crosslinking agents. The surface morphologies, particle sizes, and distributions of the microencapsulated phase change material (microPCM) were studied by scanning electron microscopy. The thermal properties, thermal reliabilities, and thermal stabilities of the microPCMs were investigated by differential scanning calorimetry and thermal gravimetric analysis. The microPCM with DVB exhibits higher phase change enthalpies of melting (87.9 J g −1 ) and crystallization (94.8 J g −1 ) and a greater thermal stability in comparison with the microPCM with PETA. The phase change temperatures and enthalpies of the microPCMs varied little after thermal cycles. Thermal images showed that the gypsum board with PSMA/ n -octadecane microPCM possessed temperature-regulated property. Therefore, microencapsulated n -octadecane with PSMA as shell has good thermal energy storage and thermal regulation potential.
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NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY
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2014
·Vol. 387
·期 11
·1079-1089
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IF 2.36
Zhao Xin,Zhang Kai-ping,Huang Ting,Yan Cai-Chuan,Liu Li-Rong,Zhu Qi-Lei,Guo Feng-Feng,Liu Chen,Li Bao-Xin
Arsenic trioxide (As 2 O 3 ) is used to treat acute promyelocytic leukemia. However, the cardiotoxicity of long QT syndrome restricts its clinical application. Previous studies showed that As 2 O 3 can damage the human ether-a-go-go-related gene (hERG) current via disturbing its trafficking to cellular membrane. This study aimed to investigate whether the As 2 O 3 -insulted hERG channel can be rescued by resveratrol, a recognized cardioprotective agent. The whole-cell patch clamp technique was used to record the hERG current and action potential duration. Co-immunoprecipitation and Western blot assay were applied to determine the function of hERG-Hsp70/Hsp90 chaperone complexes and the expression alteration of protein-folding-related proteins, respectively. Compared with treatment of As 2 O 3 alone, co-treatment with resveratrol successfully restored the current and surface expression of hERG and obviously shortened action potential duration in guinea pig ventricular myocytes. Further experiments demonstrate that resveratrol relieved As 2 O 3 -caused endoplasmic reticulum (ER) stress by restoring the function of hERG-Hsp70/Hsp90 chaperone complexes and downregulating the protein expression of ER chaperone proteins (calnexin and calreticulin) and activating transcription factor 6. In conclusion, resveratrol was able to rescue the trafficking deficiency and relieve the ER stress (ERS). Our findings suggest that resveratrol has a potential effect to alleviate the adverse effect of As 2 O 3 on cardiotoxicity.
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