ANALYST
·
2020
·Vol. 145
·期 7
·2692-2700
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IF 3.978
Menghan Li,Rongrong Zhu,Xiaoxia Song,Zhijun Wang,Hongbo Weng,Jianying Liang
Short-chain fatty acids (SCFAs) were identified as critical markers in the diagnosis of chronic and metabolic diseases, but a sensitive and stable method to determine SCFAs in feces is a challenge for analysts due to the high volatility. Herein, a sensitive and accurate method to determine SCFAs adopting precolumn derivatization coupled with gas chromatography-mass spectrometry (GC-MS) has been developed. Benzyl chloroformate (BCF) was chosen as the reaction reagent and emulsified derivatization was applied to homogenize the reaction system. Higher sensitivity, wider application and satisfactory derivatization efficiency were obtained using the developed method. An excellent method validation showed a good linearity ranging from 0.9947 to 0.9998. At the same time, the intra-day and inter-day precision were achieved in the range of 0.56% to 13.07%. The lower limits of detection of all target analytes varied from 0.1 to 5 pg. The recovery ranged from 80.87% to 119.03%, and storage stability under three different conditions was also determined. This method was also successfully applied to the analysis of SCFAs in mice fecal samples to illustrate the significant differences between normal and type 2 diabetes mellitus mice.
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Food & Function
·
2020
·Vol. 11
·期 9
·7681-7695
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IF 4.171
Zhihong Zhang,Songtao Fan,Danfei Huang,Tao Xiong,Shaoping Nie,Mingyong Xie
Lactic acid bacteria strain (LAB) NCU116 fermented Asparagus officinalis polysaccharides (FAOP) have been proven to cause substantial changes in physicochemical properties such as monosaccharide composition and molecular weight, accounting for their enhanced immune activity than unprocessed Asparagus officinalis polysaccharides (AOP). In the current study, the hepatoprotective effects of FAOP in mice with cyclophosphamide (CTX)-induced hepatotoxicity were investigated. FAOP were more effective than AOP in alleviating CTX-induced hepatic damage, including inhibition of hepatic biochemical markers (ALT, AST, AKP and LDH) and pro-inflammatory cytokines (TNF-α and IL-1β) as well as reinforcement of antioxidant systems (T-AOC, SOD, CAT, and MDA). In particular, compared with AOP, FAOP showed superior performance by promoting GSH biosynthesis, and normalizing the expression level of bile acid receptors (FXR and SHP) and key enzymes in bile acid synthesis (CYP7A1, CYP8B1 and CYP27A1). Modulation of disordered homeostasis of bile acids by FAOP can be attributed to the upregulation of hepatic short chain fatty acid (SCFA) receptors GPR41 and GPR109A as well as intestinal SCFA production. Furthermore, serum metabolomics study validated the hepatoprotective superiority of FAOP than AOP with evidence from variations in bile acid compositions and the construction of related metabolic pathways. Therefore, LAB NCU116 fermentation of Asparagus officinalis was practical and effective to obtain promising hepatoprotective polysaccharides, which might arise from enhanced SCFA production than unprocessed AOP.
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CATALYSIS LETTERS
·
2020
·Vol. 151
·期 3
·720-733
·
IF 2.482
Zhu Anlian,Li Qixing,Feng Wanlu,Fan Dongshuang,Li Lingjun
Abstract The synthesis of 2-amino-4H-chromenes through one-pot multicomponent reactions has received great attention due to the high atom efficiency and the broad bioactivities of the products. Here, the catalytic performances of a series of functional ionic liquids towards this type of reaction were investigated and the results showed that the ionic liquid, choline acetate ([Choline][Ac]), could efficiently promote this reactions under room temperature without the necessary of organic solvents. The reaction is easy to be conducted and the following work-up procedures are very simple. The pure products can be obtained through extraction and washing procedures, no column separation procedures are needed. Intriguingly, this reaction system can be easily scaled up to multi-gram, suggesting its perspective in industrial applications. In addition, the ionic liquid [Choline][Ac] can be easily prepared from cheap and biocompatible materials, and it can be feasibly recycled and reutilized for at least five cycles. Graphic Abstract
Various aldehydes, malononitrile and activated phenols could be converted to the
corresponding 2-amino-4H-chromenes with good to excellent isolated yields under
the catalysis of choline acetate at room temperature.
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POLYMER INTERNATIONAL
·
2020
·Vol. 69
·期 7
·619-626
·
IF 2.574
Liping Yin,Yanli Bao,Lin Liu,Jinze Wang,Li Chen
In clinical treatment, multidrug resistance (MDR) is one of the major obstacles resulting in the failure of chemotherapy. It is still a challenge to overcome MDR. Herein, we fabricated intelligent dextran-based dual-drug delivery systems histidine modified dextran conjugated doxorubicin/zinc porphyrin/paclitaxel (DHTD/Zn-TPP/PTX) via supramolecular metallo-coordination for synergistic chemo-photodynamic therapy to overcome cancer drug resistance. In this designed DHTD/Zn-TPP/PTX, one anticancer drug (doxorubicin, DOX) was conjugated on the dextran backbone through a reactive oxygen species sensitive linker and the other drug PTX was encapsulated into the acid responsive supramolecular micelles formed by the photosensitizer Zn-TPP and histidine grafted on dextran. DHTD/Zn-TPP/PTX with excellent stability could be effectively internalized by tumour cells. In the acidic tumour environment, the loaded PTX and Zn-TPP as photosensitizer could be released; moreover, when irradiated with light the conjugated DOX could be specifically released because the linker broke. As the obtained data indicate, DHTD/Zn-TPP/PTX exhibited not only an enhanced anticancer therapeutic effect but also significant growth inhibition for drug-resistant MCF-7/ADR cells to reverse MDR, having great potential for synergistic treatments of cancer to overcome MDR. © 2020 Society of Chemical Industry
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ChemCatChem
·
2020
·Vol. 12
·期 9
·2469-2477
·
IF 4.853
Lidong Wang,Zhaosheng Zhang,Meng Li,Qiuhan Li,Bo Wang,Shuwen Wang,Huang Zhou,Boyang Mao
Graphical HER electrocatalysis : We developed a novel Pt(II)-porphyrin based catalyst for HER electrocatalysis, its optimised performance can be quantitatively designed in molecular level. The optimized Pt(II)-porphyrin loading and precisely morphology control could be fine-tuned and quantitatively premeditated by using fluorescence and UV-vis titration based on the unique π–π interactions behaviour of the porphyrin. This study provides a new approach for preparing a highly active and stable HER catalyst, which could potentially be extended to other reactions to improve the utilization efficiency of precious metal catalysts. Functionalised porphyrins have attracted considerable attention owing to their ability to coordinate with numerous metal ions. We design and synthesize a novel composite system based on functionalised Pt(II)-porphyrin and multiwalled carbon nanotubes for hydrogen evolution reaction (HER) electrocatalysis. Rather than qualitatively integrating porphyrin with carbon nanotubes, the optimized Pt(II)-porphyrin loading and precisely morphology control could be fine-tuned and quantitatively premeditated by using fluorescence and UV-vis titration based on the unique π–π interactions behaviour of the porphyrin for the first time. The as-prepared composites exhibit superior HER catalytic activity with an overpotential of 35 mV for an electrocatalytic current density of j=−10 mA cm −2 and a Tafel slope of 32.3 mV dec −1 . Moreover, such catalysts do not exhibit observable activity decay after a 1000-cycle stability test, thus demonstrating their excellent durability. To further reduce Pt loading to achieve cost efficiency, we develop a Pt−Co bimetallic HER catalyst with an ultra-low platinum content through a straightforward synthesis pathway with high catalytic activity and stability. This study provides a new approach for preparing a highly active and stable HER catalyst, which could potentially be extended to other reactions to improve the utilization efficiency of precious metal catalysts.
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Chemical Engineering and Processing-Process Intensification
·
2020
·
IF 3.731
Zhiming Wu,Qian Zeng,Hongye Cheng,Lifang Chen,Zhiwen Qi
Separation of components of light cycle oil (LCO) into aromatic-rich and nonaromatic-rich fractions is the essential step for upgrading LCO to produce benzene, toluene, xylene enriched fraction, and high-quality diesel. In this work, extractive separation of model LCO which contains 70 wt% tetralin and 30 wt% dodecane was performed using deep eutectic solvent (DES) as the extractant and water as the anti-extractant. Tetrabutylphosphonium bromide (TBPB) and levulic acid (LA) at a molar ratio of 1:4 was determined as the extractant, due to its high and stable performance during extraction and regeneration processes. The liquid-liquid equilibrium data of ternary systems involving TBPB:LA(1:4) were then experimentally determined and fitted using non-random two-liquid model. The continuous extraction process was simulated and optimized, high mass purity (0.980 for tetralin and 0.987 for dodecane) and high recovery ratio (0.994 for tetralin and 0.954 for dodecane) were achieved.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2020
·Vol. 100
·期 6
·2554-2567
·
IF 2.614
Shasha Wang,Guangjing Chen,Kewei Chen,Jianquan Kan
BACKGROUND Carapax Trionycis is the shell of the soft-shelled turtle. It is rich in minerals, amino acid, peptides, and other nutrients. Current processing and consumption of soft-shelled turtle leads to the waste of huge quantities of Carapax Trionycis in the form of spent materials. In this study, the bioavailability, prebiotic activity, and physicochemical properties of Carapax Trionycis using different processing methods were investigated. The vinegar-quenched Carapax Trionycis (V-CT), fine powders (D0.18, D0.10), and superfine powders (D0.05, D0.025) of Carapax Trionycis were prepared by the vinegar-quenching method, common grinding, and the superfine grinding method. RESULTS The average particle sizes of D0.18, D0.10, D0.05, and D0.025 were 147.82, 77.35, 36.65, and 2.24 μm, respectively. Superfine grinding changed the surface morphology of Carapax Trionycis and promoted the release of active ingredients. D0.025 had the highest polypeptide (8.15%), polysaccharide (1.21%), total free amino acid (232.36 mg 100 g −1 ) and water-soluble extract content (10.74%), and showed the highest calcium release rate (55.64%) after in vitro digestion. The apparent permeability (P APP ) of the resulting Carapax Trionycis samples in the dialysis tubing model and the everted intestinal sac model increased significantly with the decrease in the Carapax Trionycis particle sizes. Furthermore, the five Carapax Trionycis samples significantly stimulated the growth of the tested probiotics and increased lactic acids production after 48 h fermentation compared to the control. The Carapax Trionycis powder prepared by superfine grinding displayed better prebiotic activity than other samples as it significantly induced a greater proliferation of probiotic bacteria and higher production of lactic acid, as well as greater release of free calcium. CONCLUSIONS The results showed that Carapax Trionycis superfine powder D0.025 had the highest active ingredient content, calcium bioavailability, and prebiotic activity. Our approach of developing Carapax Trionycis superfine powder as natural calcium supplement or potential prebiotic would therefore broaden the scope of soft-shelled turtle processing waste utilization in an eco-friendly, cost-effective, and sustainable approach in the future. © 2020 Society of Chemical Industry
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Xiao Zhang,Jude Juventus Aweya,Zong-Xun Huang,Zhuo-Ying Kang,Zi-Hao Bai,Kun-Huan Li,Xiao-Tong He,Yang Liu,Xian-Qiang Chen,Kit-Leong Cheong
The fermentation behaviour of sulfated polysaccharides (GLP) and their agaro-oligosaccharides (GLO) derived from Gracilaria lemaneiformis were examined. During in vitro fermentation, GLP and GLO increased the concentrations of short chain fatty acids (SCFAs) and modulated the composition and diversity of gut microorganisms compared with control groups. GLP increased the abundance of Bacteroidetes and decreased the abundance of Firmicutes, while GLO increased the abundance of Firmicutes and Actinobacteria. Moreover, the abundances of potential pathogenic bacteria were reduced. Molecular weight and intrinsic viscosity of GLP decreased significantly from 2.15 × 10 5 to 1.22 × 10 5 Da, 374.45–113.91 mL/g, respectively. Furthermore, GLP was degraded into smaller degree of polymerization of oligosaccharides, with no significant change observed in GLO. Overall, this study revealed GLP and GLO could be beneficial for gastrointestinal tract by producing SCFAs and modulating intestinal microbes, indicating GLP and GLO are potentially sources of prebiotics in functional foods.
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ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Qi Zhao,Yu Liu,Hui Ma,Yan Qiao,Jianbin Chao,Xianglin Hou,Yuqi Wang,Yingxiong Wang
Fischer-Tropsch (F-T) process is an important synthesis route to acquire clean liquid fuels through modern coal chemical industry, which converts syngas (CO and H 2 ) into hydrocarbon, and also generates oxygenates discharged as the F-T waste-water. These oxygen-containing compounds in F-T waste-water have the similar molecular weight and some are even isomers of each other. Hence, it is necessary to develop rapid and efficient analysis tools to obtain identification and quantitative information of the F-T waste-water. The pure shift NMR techniques provided only chemical shift information in one-dimension 1 H NMR spectra , without homonuclear J H-H coupling. In this work, we tested and compared three pure shift NMR techniques (including Zangger-Sterk, PSYCHE and TSE-PSYCHE methods) in the analysis of two F-T waste-water model mixtures, genuine waste-water and two alcohol isomer mixtures. The results show that J H-H coupling multiplicities are collapsed into singlets corresponding to individual chemically distinct protons of the compound. For some severely overlapped signals in the pure shift NMR spectra , the chemical shift selective filters with TOCSY (CSSF-TOCSY) experiments were conducted to assist the signal assignment. Thus, pure shift NMR approaches can identify most signals of components, and CSSF-TOCSY can extract the signal of a specific compound. The combination of these two NMR techniques offers a powerful tool to analyze the F-T waste-water or other complex mixtures including isomer mixtures.
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Yudong Zhang,Long Liang,Ziyang Chen,Jinjun Wen,Wen Zhong,Sibei Zou,Mingli Fu,Limin Chen,Daiqi Ye
Self-assembled CeO 2 with 3D hollow nanosphere, nanoparticle and nanocube morphologies were prepared and used to support Cu particles. The obtained samples (denoted as Cu/CeO 2 -hs, Cu/CeO 2 -np and Cu/CeO 2 -nc, respectively) were tested for the reverse water-gas shift (RWGS) reaction. Under the reaction conditions, V (H 2 ): V (CO 2 ) = 3:1 and weight hourly space velocity (WHSV) = 300,000 mL g −1 h −1 , the Cu/CeO 2 -hs sample exhibited the best catalytic performance among the as-prepared catalysts. In order to reveal the key factors affecting the catalytic performance, the physicochemical properties of the catalysts were analyzed by XRD, BET, SEM, TEM, H 2 -TPR, quasi in-situ XPS and in situ UV-Raman techniques. The results point out that the particle size of Cu is not the rate-determining factor while the amount of surface oxygen vacancies is highly correlated with the catalytic reaction rate. In situ UV-Raman and in situ DRIFTS experiments indicate the formation of bidentate carbonate and formate species on oxygen vacancy sites which is thought to be the key intermediates for the RWGS reaction. These findings unravel the crucial roles of surface oxygen vacancies on CO 2 adsorption and activation and also highlight a feasible way for the design of highly efficient catalysts for the important RWGS reaction in chemical industry.
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JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Yujie Zhang,Hui Zhong,Zi'ang Cao,Shouyong Zhou,Dabing Zhang,Renling Lu,Haifeng Han,Mingliang Zhang,Hongdeng Qiu
The present work described two triacontyl-bonded silica adsorbents containing different polar embedded groups ( i.e. amide- and carbamate-type) for high performance liquid chromatography, which were prepared by covalent surface modification of silica gel with respective pre-synthesized polar-embedded triacontyl (C30) silane. The acylimidazole-mediated method was used for the first time for the synthesis of amide-type alkyl silane, while the carbamate-type silane was obtained via an improved solvent-free procedure. A conventional C30 stationary phase was also developed on the same silica substrate in the similar manner, which was used as a reference column for comparison of the unique mechanisms facilitated and/or furnished by the polar groups. The successful immobilization of the designed C30 species was confirmed by infrared spectroscopy and elemental analysis. In further comparison with an amide-embedded octadecyl (C18) two other conventional C18 stationary phases of different surface chemistry, detailed chromatographic characterization of the C30 series stationary phases was performed in terms of surface density, hydrophobicity, aromatic selectivity, shape selectivity and water tolerance using a diversified range of analytes, including homologous alkylbenzenes, isomeric polycyclic aromatic hydrocarbons, carotenes, congeners of polychlorobiphenyls, aromatic amines, phenolic compounds, estrogens and nucleosides. A high resemblance between the chromatographic behaviors of the two polar-modified C30 stationary phases was observed, meanwhile they demonstrated noticeable differences from non-polar C30 stationary phase. The polar-embedded C30 phases showed satisfactory performance towards the solutes of interest in the studied conditions. The beneficial synergy of the polar groups and the triacontyl chains enabled these polar-enhanced C30 stationary phases to address challenging separation tasks with high selectivity.
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Jun-Yi Yin,Lu-Yao Ma,Ming-Yong Xie,Shao-Ping Nie,Jian-Yong Wu
Konjac glucomannan (KGM) with a molecular weight (MW) of 823.4 kDa was partially degraded by endo-1,4-β-mannanase. Two hydrolyzed KGM fractions (KGM-M-1: 147.2 kDa and KGM-M-2: 21.5 kDa) were characterized and applied to the animal tests in comparison with the native KGM. After oral feeding to the mice, KGM-M-1 and KGM-M-2 significantly increased the levels of short chain fatty acids (SCFAs) in the colonic contents and the native KGM increased the SCFAs in the cecum. The more significant effect of the native KGM in the cecum may be attributable to its high viscosity, slowing down the movement of intestinal microflora through the cecum, while the lower MW KGM-M-1 and KGM-M-2 could move more easily through the colon to be fermented by colonic bacteria. This new finding may be useful for future research and development of low-MW KGM polysaccharides through enzyme hydrolysis for the desired gut health benefits.
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危险品化学品经营许可证（带存储）