CHEMISTRY & BIODIVERSITY
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2018
·Vol. 16
·期 3
·e1800504
·
IF 1.617
Ji-Rui Wang,Long-Yun Li,Jun Tan,Xu-Hong Song,Da-Xia Chen,Jin Xu,Gang Ding
Styphnolobium japonicum (L.) S chott is widely cultivated in China, and its flowers and flower buds (FFB-SJ) are commonly used as traditional Chinese medicine. This work aimed to assess variations in the chemical components and antioxidant and tyrosinase inhibitory activities of S. japonicum extract during five flower maturity stages (ES1–ES5). The results showed that the contents of total flavonoids, rutin, and narcissin were highest at ES1, whereas the contents of quercetin and isorhamnetin were highest at ES3. ES1 presented considerable antioxidant activities in terms of reducing power (RP) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH . ) and hydroxyl radical ( . OH) scavenging capacity, whereas ES3 showed excellent tyrosinase inhibitory activity and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS .+ )- and O 2 .− -scavenging capacity. Rutin and quercetin are the main bioactive components of FFB-SJ with antioxidant and tyrosinase inhibition, and the immature flower buds of S. japonicum (S2 and S3) with excellent biological activities and relatively high extract yields were the best for product development.
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高影响因子
Biotechnology Journal
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2019
·Vol. 14
·期 7
·1800643
·
IF 3.543
Liwei Gao,Shiying Li,Yanning Xu,Chengqiang Xia,Jiadi Xu,Jun Liu,Yuqi Qin,Xin Song,Guodong Liu,Yinbo Qu
α- l -Arabinofuranosidases are important in the degradation of plant polysaccharides and are used in several industrial processes. Although the use of filamentous fungi for the production of α- l -arabinofuranosidases is widely reported, there are few reports on strain engineering for enhanced production of these enzymes by fungi. In this study, the function of transcription factor AraR in l -arabinose release and catabolism by the fungus Penicillium oxalicum ( P. oxalicum ) is investigated. Also, a mutant of AraR, AraR A731V , is constructed to improve the production of α- l -arabinofuranosidases on the basis of the sequence homology between AraR and the xylanolytic gene activator XlnR. The AraR A731V -overexpressing strain can synthesize α- l -arabinofuranosidase in the absence of an inducer and shows a 54.1-fold increase in α- l -arabinofuranosidase production and a 7.4-fold increase in α-galactosidase production in the medium containing wheat bran. Determination of the transcript abundances of lignocellulolytic enzyme genes reveals significant upregulation of multiple α- l -arabinofuranosidase genes and downregulation of some cellulolytic and xylanolytic enzyme genes in the engineered strain relative to its parent. Taken together, the results suggest the conserved regulatory function of AraR in the family Trichocomaceae and provide a strategy for engineering fungal strains for enhanced α- l -arabinofuranosidase production. Graphical α- l -Arabinofuranosidases are important in plant cell-wall degradation and are used in many industries. In this study, it is shown that a point mutation of transcription factor AraR could increase α- l -arabinofuranosidase production by 54.1-fold in the fungus Penicillium oxalicum .
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2018
·
IF 3.235
Fengming Zhao,Menglei Zhou,Lingqiao Wang,Zhangkao Huang,Youqun Chu
l -proline assisted silver nanoparticles were electrodeposited on glassy carbon electrode by one-step voltammetry method. The results of Raman spectroscopy, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy confirmed a uniform distribution of nanometer sized silver nanoparticles in the presence of l -proline and the formation of mixed silver oxides in the absence. l -proline as a stabilizer plays the very important role in slowing the oxidation of metallic silver and makes contributions to avoid aggregations. More importantly, l -proline caused nearly 200 mV potential shifted towards less negative potential and almost two-fold sensitivity increased. This low-cost and simple silver nanoparticles sensor is not only free from various disadvantages of enzyme or noble based sensors, but also provides a superior sensing performance for electrochemical detection of hydrogen peroxide. The resultant silver nanoparticles stabilized using l -proline displayed lower detection limit of 0.05 μM, larger detection linear range from 0.1 μM to 5145 μM, and higher selectivity in the presence of interfering species such as ascorbic acid , uric acid , l -glucose, glycine and lactose, for H 2 O 2 detection, relative to silver nanoparticles without l -proline. These comprehensive characterizations attribute the excellent H 2 O 2 electrocatalytic performance to its fast electron transfer kinetics of the metallic silver (Ag 0 ) in l -proline stabilized silver nanoparticles. The fabricated sensor also reliably applied in detection of H 2 O 2 in milk samples. This work suggests the l -proline assisted silver nanoparticles are promising materials for highly active and selective non-enzymatic H 2 O 2 detection.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 136
·期 44
·48177
·
IF 2.188
Xue Wan,Hongqiu Wei,Fenghua Zhang,Yanju Liu,Jinsong Leng
Four-dimensional (4D) printing of shape memory materials has attracted increasing interests for personalized structures. In this study, a biocompatible poly( d , l -lactide- co -trimethylene carbonate) (PLMC) is utilized to fabricate 4D shape-changing structures with customized geometries through direct ink writing. The printed objects show shape transformations at different dimensions under thermal programming. The influence of the printing parameters on the properties including rheological, solvent evaporation, and static mechanical behavior are systematically investigated. A printing map is further depicted to achieve high-quality printing with high viscous ink flowed from micronozzle to construct various structures. The printed structures in one-dimensional, two-dimensional, and three-dimensional (3D) exhibit shape-changing behavior with fast response around body temperature. The fast responsive time shows potential in the field of surgical suture (4 s), nonwoven fabric (3 s), and self-expandable stent (35 s). The feasibility of 3D printing of PLMC opens the way for applications in shape-changing devices with small diameter. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48177.
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PROCESS BIOCHEMISTRY
·
2018
·
IF 2.616
Jinsha Huang,Wei Zhuang,Lei Ge,Kai Wang,Zhenfu Wang,Huanqing Niu,Jinglan Wu,Chenjie Zhu,Yong Chen,Hanjie Ying
Surface amine modification could not only improve the microenvironment near the active sites of enzyme, but also enhance the multi-point chemical crosslinking between the enzyme and carrier. The linear structured polymer of ε-poly - l - lysine (EPL) is an ideal donor of amino with much more exposed on the surface for enzyme attachment. Analysis of the result of dynamic light scattering (DLS) and circular dichroism (CD) demonstrated the favorable electrostatic interactions and negligible impact on the conformation of enzymes, Glucose Oxidase and Catalase (GOx&CAT). Titration and dissociation curve together with Zeta-potential characterization revealed that enzymes (EPL@GOx&CAT) under the protection of EPL had more stable structure and better activity and stability in acidic reaction environment. Meanwhile, the activity recovery of immobilized EPL@GOx&CAT increased to 1.56 times higher than that of GOx&CAT, and the acid resistance was improved by 1.44 times with the optimum pH shifting to acidic by 0.50 unit. The substrate affinity was raised with the decrease of K m from 5.98 to 4.35 mg mL −1 . Thus, the gluconic acid production in low pH system could be increased by pH-engineering of the enzyme microenvironment via conjugation with positively charged polyelectrolyte.
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ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Shuyan Zhao,Tiankun Liang,Lingyan Zhu,Liping Yang,Tianqi Liu,Jia Fu,Bohui Wang,Jingjing Zhan,Lifen Liu
6:2 fluorotelomer sulfonic acid (6:2 FTSA) is currently used as an alternative to perfluorooctanesulfonate (PFOS) and is widely detected in the environment. The uptake, translocation and biotransformation of 6:2 FTSA in pumpkin ( Cucurbita maxima L.) were investigated by hydroponic exposure for the first time. The root concentration factor (RCF) of 6:2 FTSA was 2.6–24.2 times as high as those of perfluoroalkyl acids (PFAAs) of the same or much shorter carbon chain length, demonstrating much higher bioaccumulative ability of 6:2 FTSA in pumpkin roots. The translocation capability of 6:2 FTSA from root to shoot depended on its hydrophobicity . Six terminal perfluorocarboxylic acid (PFCA) metabolites, including perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), perfluorobutanoic acid (PFBA), perfluoropropionic acid (PFPrA) and trifluoroacetic acid (TFA) were found in pumpkin roots and shoots. PFHpA was the primary metabolite in roots, while PFBA was the major product in shoots. 1-aminobenzotriazole (ABT), a cytochromes P450 (CYPs) suicide inhibitor, could decrease the concentrations of PFCA products with dose-dependent relationships in pumpkin tissues, implying the role of CYP enzymes involved in plant biotransformation of 6:2 FTSA. This study indicated that the application of 6:2 FTSA can lead to the occurrence of PFCAs (C2–C7) in plants.
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高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Sihui Chen,Maoqiang Chi,Yun Zhu,Mu Gao,Ce Wang,Xiaofeng Lu
Superaramagnetic Fe 3 O 4 nanomaterials are good candidates as enzyme mimics due to their excellent catalytic activity, high stability and facile synthesis. However, the morphology of Fe 3 O 4 nanomaterials has much influence on their enzyme-like catalytic activity. In this work, we have developed a simple polymer-assisted thermochemical reduction approach to prepare Fe 3 O 4 nanofibers for peroxidase-like catalytic applications. The as-prepared Fe 3 O 4 nanofibers show a higher catalytic activity than commercial Fe 3 O 4 nanoparticles. The steady-state kinetic assay result shows that the Michaelis–Menten constant value of the as-obtained Fe 3 O 4 nanofibers is similar to that of horseradish peroxidase (HRP), indicating their superior affinity to the 3,3′,5,5′-tetramethylbenzidine (TMB) and H 2 O 2 substrate. Based on the outstanding catalytic activity, a sensing platform for the detection of l- cysteine has been performed and the limit of detection is as low as 0.028 μM. In addition, an excellent selectivity toward l- cysteine over other types of amino acids, glucose and metal ions has been achieved as well. This work offers an original means for the fabrication of superparamagnetic Fe 3 O 4 nanofibers and demonstrates their delightful potential applications in the fields of biosensing, environmental monitoring, and medical diagnostics.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Songqiang Deng,Tan Ke,Yanfang Wu,Chao Zhang,Zhiquan Hu,Hongmei Yin,Limin Guo,Lanzhou Chen,Dayi Zhang
Polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are predominant pollutants normally coexisting at electronic waste dumping sites or in agricultural soils irrigated with wastewater. The accumulation of PAHs and HMs in food crops has become a major concern for food security. This study explored the hydroponic uptake of 16 priority PAHs and 5 HMs (Cd, Cr, Cu, Pb, and Zn) by pak choi (Brassica chinensis L.). PAHs exhibited stronger inhibition on pak choi growth and physiological features than HMs. Five HMs were categorized into high-impact HMs (Cr, Cu, and Pb) and low-impact HMs (Cd and Zn) with distinct behavior under the coexposure with PAHs, and low-impact HMs showed synergistic toxicity effects with PAHs. Coexposure to PAHs and HMs slightly decreased the uptake and translocation of PAHs by pak choi, possibly attributing to the commutative hindering effects on root adsorption or cation−π interactions. The bioconcentration factors in PAHs + HMs treatments were independent of the octanol–water partition coefficient (Kow), owing to the cation-π interaction associated change of Kow and induced defective root system. This study provides new insights into the mechanisms and influential factors of PAHs uptake in Brassica chinensis L. and gives clues for reassessing the environmental risks of PAHs in food crops.
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RSC Advances
·
2018
·Vol. 8
·期 43
·24458-24463
·
IF 2.936
Jing Zhou,Dongrong Cai,Qingbo Xu,Yanyan Zhang,Feiya Fu,Hongyan Diao,Xiangdong Liu
Silver nanoparticles (Ag NPs) have outstanding antimicrobial effects, but their weak adhesive force onto cotton fiber surfaces often causes undesired silver loss from antibacterial fabrics, diminishing antibacterial durability, and even leading to environmental and health risks. To improve adhesion of the Ag NPs, various strategies have been tried, but achieving long-term antibacterial effectiveness still remains challenging. Here, L-methionine is proposed as a binder reagent because it has low toxicity towards mammalian cells and has a methyl group to enhance its coordination ability. The antibacterial cotton fabric was fabricated via a very simple pad-dry-cure process: after dipping a cotton fabric in an L-methionine solution followed with heating for esterification, Ag NPs are formed via the reaction of silver nitrate with sodium borohydride. The resulting cotton fabric exhibits an excellent antibacterial property and laundering durability. Its bacterial reduction rates (BR) against both S. aureus and E. coli remained over 97% even after 90 consecutive laundering cycles. Moreover, the modification causes insignificant damage to cotton's characteristics, such as tensile breaking strength, water absorptivity, and vapor permeability.
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高影响因子
CHIRALITY
·
2018
·Vol. 30
·期 11
·1182-1194
·
IF 1.833
Huimin Zang,Shun Yao,Yingjie Luo,Dan Tang,Hang Song
As one kind of functionalized green medium, chiral ionic liquids (CILs) have been widely applied in fields of asymmetric catalysis, enantioseparation, and so on. In this study, four kinds of amino acid–based CILs were synthesized by using trimethylamine, N-methylpyrrolidine, N-methylimidazole, and tropine as cationic nucleus, respectively. Then their specific optical rotation and solubility in common solvents were determined for further resolution application. The effect of different cations in these CILs was explored on the separation of racemic phenylalanine in complex-precipitation way. Moreover, various factors were systematically investigated for their effects on resolution efficiency, including the type of additive copper salts, the molar ratio of Cu (II) to CIL, pH value, the amount of racemic phenylalanine, and temperature. Under the appropriate conditions, L-phenylalanine mainly existed in solid phase and could be separated from its enantiomers in liquid phase. Furthermore, the mechanism of resolution was studied by thermogravimetric analysis, infrared spectrum, and molecular simulation. The resolution system has characteristics of no organic solvent, fast separation speed, simple resolution process, and easy scale-up.
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RSC Advances
·
2019
·Vol. 9
·期 30
·17325-17334
·
IF 3.049
Wei Yi,Zihua He,Junjie Fei,Xiaohua He
Heavy metal pollution can be toxic to humans and wildlife, thus it is of great significance to develop rapid and sensitive methods to detect heavy metal ions. Here, a novel type of electrochemical sensor for the simultaneous detection of heavy metal ions has been prepared by using poly(L-glutamic acid) (PGA) and graphene oxide (GO) composite materials to modify the glassy carbon electrode (GCE). Due to the good binding properties of poly(L-glutamic acid) (PGA) for the heavy metal ions (such as Cu2+, Cd2+, and Hg2+) as well as good electron conductivity of graphene oxide (GO), the heavy metal ions, Cu2+, Cd2+, and Hg2+ in aqueous solution can be accurately detected by using differential pulse anodic stripping voltammetry method (DPASV). Under the optimized experiment conditions, the modified GCE shows excellent electrochemical performance toward Cu2+, Cd2+, and Hg2+, and the linear range of PG/GCE for Cu2+, Cd2+, and Hg2+ is 0.25–5.5 μM, and the limits of detection (LODs, S/N ≥ 3) Cu2+, Cd2+, and Hg2+ are estimated to be 0.024 μM, 0.015 μM and 0.032 μM, respectively. Moreover, the modified GCE is successfully applied to the determination of Cu2+, Cd2+, and Hg2+ in real samples. All obtained results show that the modified electrode not only has the advantages of simple preparation, high sensitivity, and good stability, but also can be applied in the field of heavy metal ion detection.
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JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2019
·
IF 4.978
Ping Kou,Yu-Fei Kang,Li-Tao Wang,Li-Jun Niu,Ying Xiao,Na Guo,Qi Cui,Yan-Yan Li,Yu-Jie Fu
This study explored an integrated strategy for extraction and preparative separation of four anthocyanins from Ribes nigrum L. using DES-based microwave assisted extraction and flash chromatography. The extraction yield of anthocyanins reached 2.03 mg/g after optimization. An efficient preparative separation process of four main anthocyanins by macroporous resin and flash chromatography was established afterwards. The yields of D3G, D3R, C3G and C3R reached 0.32 mg/g, 0.47 mg/g, 0.18 mg/g and 0.43 mg/g with the purities of more than 95%, respectively. The developed procedure represents an efficient and convenient alternative for the systematic utilization of natural products from plant materials.
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危险品化学品经营许可证（带存储）