Journal of Environmental Chemical Engineering
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2019
·
IF 0
Hao Chen,Xialei Wang,Xilei Lyu,Ling Xu,Juncheng Wang,Xiuyang Lu
Recovering heavy metals from a hyperaccumulator is of significant interest; however, such metals are typically extracted in the liquid phase, which increases the cost of recovery. In this work, hydrothermal processing is used to extract Cd, Cu, Pb and Zn from enriched Sedum alfredii Hance in order to separate the heavy metals into the solid phase for easy recovery and the simultaneous production of bio–oil. The results show that almost all enriched Cd, Cu, Pb and Zn (87.8% Ce, 87.5% Cu, 90.2% Pd and 87.2% Zn) are concentrated in the solid phase at only 320 °C (30 min), which also contains considerable carbohydrates. Interestingly, the additives/H 2 O 2 do not affect the removal of metals during the hydrothermal process. The yield of bio-oil is 21.5% (38.1 MJ/kg of calorific value) and is obtained with almost no heavy metals. Finally, we use different ratios of metals ions to reducing sugars as well as the non-hyper accumulating ecotype Sedum alfredii Hance to study the behavior of metals’ recovery. It is showed that the heavy metals are recovered in the solid phase due to reducing substances in the biomass that convert metal ions to the metallic state.
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ANALYST
·
2018
·Vol. 143
·期 10
·2369-2376
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IF 3.864
Fan Hu,PinPing Wu,RuYa Wang,Wei Liu,Hua He
Herein, a simple, novel, and rapid colorimetric sensor for cimetidine (Cim) detection based on D-xylose protected gold nanoparticles (D-x@AuNPs) has been developed for the first time. The D-x@AuNPs were characterized by UV-vis, TEM and FT-IR techniques. Cimetidine causes the aggregation of D-x@AuNPs due to the formation of a strong covalent Au–N bond and electrostatic binding. As the cimetidine concentration increased, the color of the solutions gradually changed from wine-red to blue, and the large absorption band shifted from 533 to 680 nm upon D-x@AuNP aggregation. The effects of different experimental parameters were investigated. A comparative study on the detection of Cim using citrated capped AuNPs and D-x@AuNPs was presented. Under optimum conditions, the UV-vis spectra showed that the absorption ratio (A680/A533) increased linearly with the concentration of cimetidine in the range of 7 × 10−8 to 3 × 10−6 M with a correlation coefficient of 0.9956 and a limit of detection of 1 × 10−8 M without needing any complicated instruments. The selectivity of the D-x@AuNP detection system for cimetidine was excellent when compared with other ions and analytes. Due to their rapid and visible color changes, and their remarkable selectivity, the D-x@AuNPs synthesized in this study were suitable and could be applied to the detection of cimetidine in human urine.
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FUEL PROCESSING TECHNOLOGY
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2018
·
IF 3.956
Siquan Xu,Donghui Pan,Yuanfeng Wu,Xianghai Song,Lijing Gao,Wenqi Li,Lalitendu Das,Guomin Xiao
We present here a study of the production of furfural from xylose and wheat straw using the chromium phosphate (CrPO 4 ) with Lewis and Brønsted acidity as a highly efficient catalyst in the water/tetrahydrofuran (THF) biphasic system. The effects of various reaction parameters including reaction temperature, reaction time, system, and catalyst dosage were explored to evaluate the product yield. Under CrPO 4 catalysis, an excellent furfural yield could reach 88% from the xylose at 160 °C for 60 min. Meanwhile, 67% furfural and 32% 5‑hydroxymethylfurfura (HMF) were simultaneously achieved from wheat straw at 180 °C for 90 min. Mechanistic studies suggested that the perfect catalytic activity of CrPO 4 was due to its inherent bifunctional catalysis activity. It was found that the CrPO 4 was easily to be recovered and a great catalytic activity was available after four cycles, which not only contributed to a sustainably reduced energy consumption on catalyst recovery , but also reduced the concerns associated with toxic chromium element.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Yao Xu,Huiyan Jiang,Congyong Sun,Michael Adu-Frimpong,Wenwen Deng,Jiangnan Yu,Ximing Xu
In this study, two polysaccharide fractions (RRP1: Mw = 5.5 kDa, and RRP2: Mw = 425.7 kDa) were isolated from Rhodiola rosea to investigate their antioxidation and hepatoprotective effects. Physicochemical analysis showed that RRP1 was composed of mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose with a relative molar ratio of 0.69:0.11:0.15:1:0.51:7.5 and RRP2 was consisted of mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose (relative molar ratio = 0.15:0.19:1.01:0.18:0.47:1). Periodate oxidation and Smith degradation analysis revealed that, in RRP1, part of the arabinose and glucose residues were 1 → 3,6/1 → 3/1 → 2,3/1 → 3,4/1 → 2,4/1 → 2,3,4-linked, and the mannose, rhamnose and galactose residues were 1 → 2,6/1 → 6/1 → 2/1→/1 → 4,6/1 → 4-linked. In RRP2, the rhamnose, glucose and galactose residues were linked by 1 → 3,6/1 → 3/1 → 2,3/1 → 3,4/1 → 2,4/1 → 2,3,4 linkages, and the arabinose and mannose residues were 1 → 2/1 → 6/1 → 4-linked. The methylation analysis confirmed the structure information of the two fractions. Importantly, fraction RRP1 demonstrated stronger antioxidative activities than RRP2 by scavenging DPPH, hydroxyl and superoxide anion radicals in vitro. Correspondently, RRP1 showed more significant effects than RRP2 on decreasing the levels of ALT, AST and MDA, and increasing the GSH, SOD and CAT levels in the CCl 4 -treated mice. These data demonstrated that the polysaccharide RRP1 could be developed as a promising candidate for preventing and treating liver damage induced by toxic chemicals.
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INDUSTRIAL CROPS AND PRODUCTS
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2018
·
IF 3.849
Shudong He,Zuoyong Zhang,Hanju Sun,Yuchen Zhu,Jinlong Zhao,Mingming Tang,Xiangyu Wu,Yanping Cao
Rapeseed peptide was used to produce flavor enhancer via heating with d -xylose at various temperatures (80–140 °C) at reaction pH 7.4 for 2 h with or without l -cysteine (RXC or RX). Effects of temperatures and l -cysteine on the Maillard reaction products (MRPs) were investigated by the determinations of pH, color, free amino acids (FAA), and volatile compounds, as well as E-nose and E-tongue analyses. Partial least square regression (PLSR) method was further applied to explore the correlations. Results suggested that pH decreased more significantly in RXCs, and a more dark brown color was observed in RXs with the increase of heating temperatures. The lowest bitterness MRPs were obtained by heating at 140 °C with cysteine (RXC-140), while the highest umami and saltiness sample was found in RX-100. Bitter and umami FAAs were present in greater amounts at higher temperatures with cysteine. Furthermore, RXC showed a meat-like flavor due to the generation of sulfur-containing compounds, and more furans and nitrogen-containing compounds were detected in RX, along with a caramel-like flavor.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
·
IF 3.909
Baolei Fan,Tingting Li,Xiaofang Song,Chao Wu,Chunqi Qian
A specific HPLC-MS/MS (High-Performance Liquid Chromatography with tandem Mass Spectrometry) method was developed and validated for simultaneous determination of several monosaccharides in three kinds Osmanthus fragrans Lour . After extraction, separation, protein removal, pigment removal and hydrolysis , monosaccharides was finally obtained from Osmanthus fragrans Lour . Positive ion mode detection and Multiple Reaction Monitoring (MRM) mode were used for quantitative analysis by PMP pre-column derivatization and Electrospray Ionization (ESI). Analysis and content determination of 6 monosaccharide components in 3 kinds of Osmanthus fragrans Lour . The HPLC separation was achieved on a Shim-pack VP-ODS6022748 (150 L × 2.0) with gradient elution at a flow rate of 0.2 ml/min in a run time of 40 min, and the mobile phase was acetonitrile-5 mmol/L ammonium acetate. PMP derivatization in HPLC-MS/MS can accurately measure Osmanthus fragrans Lour . mannose (Man), ribose (Rib), rhamnose (Rha), galacturonic acid (Gal UA), glucose (Glu), galactose (Gal), xylose (Xyl), fucose (Fuc). The results showed that HPLC-MS/MS pre-column derivatization method was simple and rapid, with small measurement error, but high sensitivity and good repeatability. The analysis of monosaccharide components in polysaccharide components has important practical significance.
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Biomed Research International
·
2018
·
IF 2.583
Xiaonan Zhang,Qingfeng Ban,Xibo Wang,Zhongjiang Wang
We adopted and developed an ultrasonic-assisted extraction method to obtain polysaccharides from tree peony pods using polyethylene glycol (PEG) as the solvent. The technological parameters have been designed as a single factor to enhance the tree peony pod polysaccharide extraction yield. Specific conditions (ultrasound irradiation power, 250 W; ultrasound irradiation time, 30 min; reaction temperature 50°C; liquid-solid ratio, 25 mL/g; and concentration of PEG, 0.2 g/mL) generated an experimental yield of 14.14% 0.44%. Subsequently, the monosaccharide composition of the tree peony pod polysaccharides was determined by HPLC using a 1-phenyl-3-methyl-5-pyrazolone precolumn derivatization method. The results indicated that tree peony pod polysaccharides contained mannoses, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose with a molar ratio of 1.44 : 2.87 : 0.32 : 18.99 : 3.99 : 10.21 : 0.96 : 1.85 : 0.21. The tree peony pod polysaccharides obtained are mainly galacturonic acid and galactose, which are acidic polysaccharides. Finally, the antioxidant activities (DPPH and FRAP) of the tree peony pod polysaccharides were assessed, and the compounds exhibited moderate antioxidant activities.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2019
·Vol. 36
·期 5
·740-752
·
IF 2.476
Gong Chen,Wei Junnan,Tang Xing,Zeng Xianhai,Sun Yong,Lin Lu
Biomass-derived levulinic acid (LA) and its esters are currently envisaged as versatile, renewable platform chemicals. In this study, cellulosic pulp derived from the cooking of lignocellulosic biomass with active oxygen and solid alkali was employed as raw material for the formation of LA or ethyl levulinate (EL). This pretreatment process is highly effective for the delignification and deconstruction of lignocellulose matrix, making a facile degradation of the resulting cellulosic pulp to LA or EL. At this point, the acid-catalyzed hydrolysis or ethanolysis of cellulosic pulp was optimized by response surface methodology (RSM), offering desirable LA yield of 65.3% or EL yield of 62.7%, which is significantly higher than those obtained from raw biomass. More importantly, coking behavior on the inwall of the reactor was eliminated during the hydrolysis or ethanolysis of cellulosic pulp, which is one of the top challenges for the acid-catalyzed conversion of biomass in an industrial scale.
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COMBUSTION AND FLAME
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2019
·
IF 4.12
Bin Hu,Qiang Lu,Zhen-Xi Zhang,Yu-Ting Wu,Kai Li,Chang-Qing Dong,Yong-Ping Yang
The fast pyrolysis mechanism of xylose , xylobiose and xylan was investigated with combined fast pyrolysis experiments and quantum chemistry calculations. The results indicate that acyclic d -xylose is an important intermediate for the formation of the major pyrolytic products in xylose pyrolysis, i.e., 1,4-anhydro- d -xylopyranose (ADX), furfural (FF) and hydroxyacetaldehyde (HAA). ADX derives from the successive cyclization of d -xylose which is the only source for ADX formation. 3-Deoxy-xylose is the most important intermediate for FF formation. HAA results from the C C bond scission by retro-aldol and cyclic Grob fragment. In addition, the five-membered intermediate derived from the ring-contraction reaction can transform into FF with high selectivity. The dehydrated xylose is also another source for HAA formation. The fast pyrolysis mechanism of xylobiose is similar to that of xylose, and thus similar pyrolytic product distribution can be obtained from them. However, the pyrolytic products of xylan differ significantly from those of xylose and xylobiose, which is ascribed to its high degree of polymerization and the branches in it.
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FOOD RESEARCH INTERNATIONAL
·
2019
·
IF 3.579
Ruiqiu Zhao,Ninghui Cheng,Paul A. Nakata,Liyan Zhao,Qiuhui Hu
The objective was to determine the contribution of A. auricular polysaccharides (AAP) in modulating the composition and diversity of the intestinal microbe in mice. AAP was extracted from A. auricula freeze-dried powder and different amounts of AAP (40, 80, 160 mg AAP/kg body weight) were administered to 6 week-old male ICR mice by gavage feeding over a five-week period. AAP feeding changed the intestinal environment in the mice. The pH value of the intestinal compartments decreased while SCFAs concentrations increased in AAP-fed groups, in a dose dependent manner, compared to the controls ( P < .05). High throughput sequencing revealed an enrichment in the diversity and an alteration in the composition of the fecal microbiota in the AAP fed mice with a significant decrease in the Firmicutes/Bacteroidetes ratio ( P < .05). The relative abundances of Porphyromonadaceae and Bacteroidaceae also increased in the AAP fed mice which positively correlated with an increase in serum IgA and IgG concentrations ( P < .05). The findings from this study show that AAP modulates the mouse gut microbiota and may contribute, at least in part, to some of the reported beneficial effects from the consumption of the mushroom, A. auricula .
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ACS Catalysis
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2018
·
IF 11.384
Yue Yan,Zihao Zhang,Seong-Min Bak,Siyu Yao,Xiaobing Hu,Zulipiya Shadike,Chi-Linh Do-Thanh,Feng Zhang,Hao Chen,Xilei Lyu,Kequan Chen,Yimei Zhu,Xiuyang Lu,Pingkai Ouyang,Jie Fu,Sheng Dai
Chemocatalysis of sugars to methyl lactate (MLA) exhibits great advantages over the conventional fermentation approach because of its higher productivity and cost-effective separation process. However, widely used supported metal oxide catalysts suffer from deactivation resulting from sintering during the reaction and removal of coke at high temperatures. Herein, we report ultrasmall cobalt oxide clusters (∼1.7 nm) stabilized within silicalite-1 crystals catalyst (CoO@silicalite-1), exhibiting superior catalytic activity and resistance to sintering for the conversion of fructose into methyl lactate. HAADF-STEM, EDS-mapping, and XRD experiments identify the existence of confined CoO clusters. XANES and Raman spectra demonstrated the covalent interaction between CoO and silicalite-1. Thanks to the ultrasmall CoO particle size (∼1.7 nm), the CoO@silicalite-1 affords nearly 100-fold higher Co-mass-based activity (mg MLA/mg Co) compared with CoO or Co3O4 particles outside the silicalite-1 framework. More importantly, this catalyst exhibits good reuse performance via the removal of coke with facile calcination.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Zhengyu Hu,Penghui Wang,Hongli Zhou,Yaping Li
Response surface methodology (RSM) combined with a Box–Behnken design (BBD) was used to optimize the hot-water extraction (HWE) conditions which were determined to be: liquid-solid ratio 29.25:1 mL/g, extraction time 1.66 h, extraction temperature 95 °C, the optimized yield of polysaccharides 0.47 ± 0.01% ( n = 3). Hot-water extraction polysaccharides (HWEP) and Microwave-assisted extraction polysaccharides (MAEP) both consist of Rha:Xyl:Ara:Fru:Glu with the molar ratio of 1.05:1.21:3.86:1:3.61:4.5 and 1:1.95:1.72:1.78:4.36:6.18, respectively. Ultrasound-assisted extraction polysaccharides (UAEP) consists of Rha:Xyl:Ara:Fru:Man:Glu with the molar ratio of 1:2.31:5.23:1.05:3.17:4.17:7.89. The molecular weight distribution of HWEP, MAEP and UAEP ranged from 16 kDa to 1698 kDa, 15 kDa to 913 kDa, and 17 kDa to 1118 kDa, respectively. The absorption peaks in FT-IR confirmed the skeletal modes of the pyranose ring in polysaccharides. The second derivative of FT-IR proved difference of polysaccharides obtained from different extraction methods. The antioxidant activity investigations shown all three polysaccharides extracts possess high scavenging activity of DPPH radicals, hydroxyl radical and ABTS+ radical. Polysaccharides from Carex meyeriana Kunth (CMKP) might be potentially used for various practical applications such as medical and food industries, and this paper provides a theoretical basis and reference for further study of CMK.
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