TALANTA
·
2019
·
IF 4.916
Yuanyuan Xia,Faqiong Zhao,Baizhao Zeng
A novel L -tryptophan ( L -Trp) electrochemical sensor is fabricated, which is based on the molecularly imprinted copolymer (MIP) of dual –functional monomers and ionic liquid (i.e. 1-butyl-3-methylimidazolium hexafluorophosphate) functionalized multi-walled carbon nanotubes (MWCNTs@IL). The MWCNTs@IL is prepared via ion exchange, while the MIP is synthesized by using L -Trp as template, styrene and 4-vinylbenzoic acid as functional monomers, Triton X-100 as emulsifier , 1, 2-divinylbenzene as cross-linking reagent and K 2 S 2 O 8 as initiator. Prior to copolymerization the functional monomer 4-vinylbenzoic acid is combined with the template molecule by forming amide bond. The template molecule is eluted by hydrolysis, and rebound by electrostatic, hydrogen-bond and π-π interaction. To construct L -Trp sensor a little of Nafion is introduced to enhance the stability and to promote rebinding. The resulting sensor Nafion-MIP-MWCNTs@IL/GCE shows a wide linear range (8 nM–26 μM) and a low detection limit (6 nM). It is successfully applied to the determination of L -Trp in oral liquid and human serum samples.
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INDUSTRIAL CROPS AND PRODUCTS
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2019
·
IF 4.191
Lu Wang,Xue Lin,Jiachao Zhang,Weimin Zhang,Xiaoping Hu,Wu Li,Congfa Li,Sixin Liu
Non-extractable/bound phenolics from plant matrices played an increasingly important role in human health benefits, but conventional solvent extraction missed high amounts of bound phenolics. In this study, Rubus idaeus L. leaves (RDLR) and seeds residues (RDSR) free of extractable phenolics were treated by different methods, respectively. The results revealed that acid, alkaline, and enzymatic hydrolysis can all significant improve the releasing of bound phenolics. Moreover, acid hydrolysis was the most efficient method for releasing the bound phenolics from RDLR and RDSR, followed by enzymatic hydrolysis. The quantitative results showed that most of individual phenolic compounds were significantly enhanced from RDLR and RDSR after acid hydrolysis. Especially for ellagic acid , was increased by 156.1-folds for RDLR and 101.8-folds for RDSR compared with methanol extraction. For RDLR or RDSR, regardless of the hydrolysis methods, higher contents of bound phenolics evidently showed the stronger antioxidant activities and inhibitory potency in α -glucosidase. Importantly, a significantly positive correlation existed in between the investigated bio-activities and bound phenolics/flavonoids released from RDLR or RDSR. These results provided comprehensive approaches for treating the residues of agricultural crops or fruit tree leaves enriched in bound phenolics, thereby to enhance their bio-accessibility.
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AICHE JOURNAL
·
2019
·Vol. 65
·期 6
·e16596
·
IF 3.463
Xuke Zhang,Hui Li,Weizhen Miao,Qin Shen,Jing Wang,Donglai Peng,Jindun Liu,Yatao Zhang
The novel functional superwettable materials for high-efficiency oil/water separation are urgently required due to oil pollution in water body caused by oil tanker accidents, seabed oil production, and oil from refineries and petrochemical plants. Here, the superhydrophobic and superoleophilic zeolitic imidazolate framework-L (ZIF-L) mesh with antimicrobial effect was successfully fabricated by in-situ growth, composed of vertically ZIF-L with micro-/nanodagger-like structure and exhibited the water contact angle of 155.4 ± 1.8° and the oil contact angle of 0° in air. Furthermore, ZIF-L was verified to have an excellent antimicrobial activity, which endowed ZIF-L mesh with good antimicrobial performance. ZIF-L mesh provided a permeation flux with 1.75 × 10 5 L m −2 hr −1 and 99.7% separation efficiency after 10 cycles operations for water mixtures with isooctane and presented optimal stability. Accordingly, the results demonstrated that ZIF-L as a new material shows an attractive applied promise for oil/water separation in industry.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Xinbao Li,Kaihui Li,Ali Farajtabar,Yating He,Gaoquan Chen,Hongkun Zhao
The solubilities of d-tryptophan in neat n-propanol, ethyl acetate, ethylene glycol (EG), n-butanol, acetonitrile, 1-octanol, and dimethyl sulfoxide and of l-tyrosine in ethyl acetate, EG, isopropanol, acetonitrile, n-butanol, and N,N-dimethylformamide (DMF) were determined via a shake-flask method at temperatures from 283.15 to 328.15 K under about 101.2 kPa. At the fixed temperature, the mole fraction solubility of d-tryptophan was the largest in EG and the lowest in 1-octanol. However, for l-tyrosine, the maximum solubility was observed in the ethyl acetate and minimum in n-butanol. X-ray powder diffraction analysis was carried out to analyze the solids equilibrated with the corresponding liquor, indicating that no polymorphic transformation or solvate formation took place in the studied systems. The solubility correlation was performed via the Apelblat equation. The obtained maximum root-mean-square deviation and relative average deviation values were 13.65 × 10–5 and 4.32%, respectively. In addition, the solvent–solvent and solute–solvent interactions were investigated on the basis of the approach of linear solvation energy relationship.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Hongwei Pan,Zengwen Cao,Yunjing Chen,Xiangyu Wang,Shiling Jia,Huili Yang,Huiliang Zhang,Lisong Dong
A comparative study on interfacial crystallization of poly( l -lactic acid) (PLLA) with different stereoregularity (PLLA2003D 96.0%, PLLA4032D 98.5%, and PLLA290 99.2%) surrounding macroscopic basalt fibers (BF) has been carried out in polymer composites. The effect of stereoregularity on the interface crystallization was systemically studied by microstructure. From polarized optical microscopy (POM) analysis, it was found that the transcrystallinity of PLLA was influenced by temperature. Moreover, stereoregularity significantly affects the crystallization kinetics . It was also found that increased molecular mobility providing faster orientation with high stereoregularity and low molecular weight. It might be the reason for the observation that the PLLA290 samples crystallized more rapidly than the PLLA4032D samples. Appropriate molecular stereoregularity exhibits a clear increase in extensional stress that is directly correlated with the crystalline orientation of the crystallization samples. The mechanism of formation of transcrystallinity underwent the process of “a mismatch in thermal expansion coefficients” with the extensional stress.
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高影响因子
MOLECULES
·
2019
·Vol. 24
·期 12
·2266
·
IF 3.06
Xueying Liu,Xiaoku Ran,Muhammad Riaz,Haixue Kuang,Deqiang Dou,Decheng Cai
The major objective of this study was to investigate the anti-chronic nonbacterial prostatitis (CNP) mechanism ofT. patulaby metabolomics and network pharmacology. The study demonstrated that the flavonoids and polysaccharides ofT. patulacould alleviate prostatitis by improving the level of DHT, reducing the secretion of PSA and TNF-α. Besides, both could enhance Na+/K+-ATPase activity, decrease the O2consumption, CO2production, heat production, energy expenditure of rats and promote respiratory exchange ratio of rats. Up to 28 potential biomarkers and 8 key metabolic pathways related to the treatment of CNP were elucidated by the metabolomics analysis, including phenylalanine metabolism, taurine and hypotaurine metabolism, tryptophan metabolism etc. Network pharmacology prediction also reflected the potential mechanism was associated with tryptophan metabolism and energy pathway. Generally, the potential anti-CNP mechanism of flavonoids and polysaccharides ofT. patulamight be through reducing the expression of inflammation factors, adjusting the level of hormone and regulating the amino acid metabolism, energy metabolism and glucose and lipid metabolism.Keywords:Tagetes patulaL.;chronic nonbacterial prostatitis;metabolomics;energy metabolism;network pharmacology
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Microbial Cell Factories
·
2019
·Vol. 18
·期 1
·1-10
·
IF 4.402
Xu Jian-Miao,Li Jian-Qiang,Zhang Bo,Liu Zhi-Qiang,Zheng Yu-Guo
Background l -2-aminobutyric acid ( l -ABA) is an unnatural amino acid that is a key intermediate for the synthesis of several important pharmaceuticals. To make the biosynthesis of l -ABA environmental friendly and more suitable for the industrial-scale production. We expand the nature metabolic network of Escherichia coli using metabolic engineering approach for the production of l -ABA. Results In this study, Escherichia coli THR strain with a modified pathway for threonine-hyperproduction was engineered via deletion of the rhtA gene from the chromosome. To redirect carbon flux from 2-ketobutyrate (2-KB) to l -ABA, the ilvIH gene was deleted to block the l -isoleucine pathway. Furthermore, the ilvA gene from Escherichia coli W3110 and the leuDH gene from Thermoactinomyces intermedius were amplified and co-overexpressed. The promoter was altered to regulate the expression strength of ilvA* and leuDH . The final engineered strain E. coli THR Δ rhtA Δ ilvIH /Gap- ilvA *-Pbs- leuDH was able to produce 9.33 g/L of l -ABA with a yield of 0.19 g/L/h by fed-batch fermentation in a 5 L bioreactor. Conclusions This novel metabolically tailored strain offers a promising approach to fulfill industrial requirements for production of l -ABA.
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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 1
·249-255
·
IF 0.524
Tian Tian,Hu Xiaoling,Guan Ping,Tang Yimei,Wang Hongli
L-(+)-α-(positive butyl)-leucine ethyl ester bromide chiral ionic liquid was synthesized by using microwave-assisted synthesis method and L-(+)-α-(positive butyl)-leucine ethyl ester terafluoroborate and hexafluorophosphate chiral ionic liquids were synthesized by the anion exchange reaction. The structures were characterized by IR, 1HNMR and structure optimization calculation. The results of studies on physicochemical properties show that they possess better thermal stability, solubility, bio-solubility and high conductivity. They can serve as effective reaction media as well as chiral catalysts. They are presently being investigated as dispersion agents in molecular imprinting ployer.
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TALANTA
·
2018
·
IF 4.244
Wenya Feng,Juan Qiao,Dan Li,Li Qi
Utilizing block copolymers as coatings, a protocol of chiral ligand exchange capillary electrochromatography (CLE-CEC) protocol was designed and developed with dual ligands for D,L-amino acids enantioseparation. Four block copolymers including poly maleic anhydride- co -styrene- co -N-methacryloyl- L -histidine methyl ester [P(MAn-St-MAH)], poly maleic anhydride- co -styrene- co -N-methacryloyl- L -lysine methyl ester [P(MAn-St-MAL)], poly maleic anhydride- co -styrene- co -N-methacryloyl- L -phenylalanine methyl ester [P(MAn-St-MAP)] and poly maleic anhydride- co -styrene- co -N-methacryloyl- L -threonine methyl ester [P(MAn-St-MAT)] were synthesized by reversible addition fragmentation chain transfer polymerization reaction. Key factors affecting the enantioresolution were optimized, including the concentration of Zn (II) central ion, pH value of buffer solution and monomers of the block copolymers. The enantioresolution of the proposed CLE-CEC system could be enhanced dramatically by employing P(MAn-St-MAH) as the immobilized chiral ligand and by coordinating the synergistic effect of free ligand in buffer solution. The principle of improved enantioresolution of the CLE-CEC system with dual ligands was discussed. Well enantioseparation was successfully realized with 7 pairs of D,L-amino acids enantiomers baseline separation and 5 pairs part separation. For quantitative analysis of D, L -alanine, a good linearity was established in the range of 9.4 μM to 1.5 mM (r 2 = 0.997) with the limits of detection (LODs) 3.7 μM of D -alanine, 2.0 μM for L -alanine, and limits of quantification (LOQs) 9.0 μM for D -alanine and 6.0 μM for L -alanine. The peak area and migration time reproducibility (n = 6) were 4.1% and 3.5% for D -alanine, 3.7% and 3.1% for L -alanine. Further, the enzyme kinetics study of alanine aminotransferase was investigated with the constructed CLE-CEC system.
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NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 4
·2476-2482
·
IF 3.201
Fanglin Cai,Wei Su,Hussein A. Younus,Kui Zhou,Cheng Chen,Somboon Chaemchuen,Francis Verpoort
While the role of negatively charged axial ligands (e.g. Cl−, Br− and I−) in tuning the reactivity and stability of molecular Ru water oxidation catalysts was well-documented, less was explored when axial ligands are neutral molecules. In this work, we reported the synthesis and full characterization of [Ru(NCNHCO)(bpy)L]+ complexes (L = DMSO, 1; L = 4-picoline, 2), where L is a neutral axial ligand. The effects of these axial ligands on the stability and reactivity of the catalysts were thoroughly investigated. Both complexes were competent to oxidize water with turnover numbers up to 463 and 107, respectively. Complex 1 initiated the water oxidation involving a PCET process. It was found that complex 2 afforded its corresponding Ru–aqua complex owing to the carboxylate dissociation, while complex 1 exhibited considerable stability in acidic aqueous solutions. On the other hand, in the presence of an oxidant, for complex 1 DMSO/H2O exchange occurred, facilitating water oxidation. In contrast, the Ru–O bond cleavage of complex 2 was inhibited, leading to an inferior catalytic performance.
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TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS
·
2018
·Vol. 71
·期 5
·1113-1126
·
IF 0.91
Chen Jin-ping,Zhang Xue-song
Four hydrosoluble macroazacyclic compounds, phosphorus phthalocyanine and substituent phosphorus triaza tetrabenzo corrole substituted with amino or sulfonate groups respectively, were investigated as corrosion inhibitors for mild steel in 1 mol/L HCl. The results obtained from weight loss test showed that the inhibitive efficiency of phosphorus phthalocyanine was higher than the phosphorus triaza tetrabenzo corrole; while the amino substituent phosphorus phthalocyanine showed the strongest inhibitive ability among them. The potentiodynamic tests illustrated that these inhibitors protected steel according to the mixed type mechanism on electrochemistry; while the impedance spectra revealed the increasing of charge transfer resistance and the decreasing of double layer capacitor caused by the adsorption of inhibitors. The surface analysis (XPS and SEM) proved the protection of steel surface by the adsorbed inhibitors. The molecular dynamic simulation indicated the advantages of phosphorus phthalocyanine as inhibitors associating with highly binding stability and stable adsorption configuration. The unique degradation properties of these inhibitors under visible light made them useful with environmental advantage in application.
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Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 42
·6865-6876
·
IF 4.776
Weijun Zhang,Kunxi Zhang,Shifeng Yan,Jie Wu,Jingbo Yin
A hydrogel with excellent mechanical properties and self-healing ability provides a promising tool for the repair of load-bearing tissues under a dynamic microenvironment. In this study, poly(L-glutamic acid) (PLGA)-based composite hydrogels with good toughness and self-healing ability were fabricated via filling soft self-healing hydrogels into a tough porous hydrogel skeleton. The PLGA-based tough porous hydrogel skeleton was treated by laser ablation to form a uniform porous structure with 85% porosity and 260 μm pore diameter, and the structure formation was reinforced by the hydrophobic assembly mechanism. The resulting hydrogel skeleton possessed good toughness (maximum compressive stress of 0.51 MPa with strain of 80%) and could fully recover after cyclic compression tests. Furthermore, PLGA-based self-healing hydrogels were fabricated based on a Schiff base reaction, followed by being composited with a tough porous hydrogel skeleton. More importantly, the composite hydrogel exhibited a homogenous interpenetrated structure that inherited mechanical strength and the self-healing ability of the two original compositions. These composite hydrogels exhibited a compressive failure stress of 0.21 MPa at a 63% strain, which was 1.3-fold higher than the value of the original porous hydrogel skeleton at 63% strain. The healing percentage gradually reached 81% within 6 h, indicating the good self-healing efficiency. Furthermore, live/dead staining images revealed that 89% of laden cells remained alive after culture for 7 days. Moreover, the composite hydrogel could self-heal even after cell encapsulation. The developed PLGA-based composite hydrogel will be a promising biomaterial for the repair of load-bearing tissues.
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