CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Kaijun Dong,Jun Zhang,Weimin Luo,Lin Su,Zhilin Huang
An acid functionalized porous organic hyper-cross-linked polymer (HCP) derived from benzene monomer was prepared for catalytic dehydration of carbohydrates into 5-hydroxymethyl furfural (HMF) in a DMSO solvent. Systematic characterizations of the HCP catalysts including essential structural properties, sulfur content and acid amount, were identified by XRD, XPS, FESEM, Raman, NH 3 -TPD, TGA, nitrogen physisorption and elemental analysis. Optimization of reaction parameters such as acid amount, solvent, substrate type, temperature and catalyst dosage, and comparison with reported solid acids were systematically investigated. The results showed that sulfonated HCP materials were highly active in fructose dehydration, which could afford a highest HMF yield of 96.7% at almost 100% fructose conversion in 30 min. Furthermore, the catalyst presented satisfied performance and stability during recycling tests. More importantly, the sulfonated HCP catalysts also exhibited promising activity in hydrolytic reaction, esterification and transesterification for platform chemicals production in biomass transformation.
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Food Analytical Methods
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2015
·Vol. 8
·期 10
·2588-2594
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IF 1.956
Jiang Ting-Fu,Chong Lei,Yue Mei-E,Wang Yuan-Hong,Lv Zhi-Hua
In this study, the separation and determination of carbohydrates in food samples were developed by capillary electrophoresis using dynamically coating the capillary with indirect UV detection. The polycationic polymers of hexadimethrine bromide (HDB) were used as electroosmotic flow (EOF) modifier to reverse the EOF. A highly alkaline pH condition was used in order to charge every carbohydrate negatively. Several important parameters influencing buffer concentration, pH, and HDB concentration were optimized. The optimal background electrolyte composed of 20 mmol L −1 sorbic acid, 0.005 % ( w / v ) HDB, and 40 mmol L −1 NaOH at pH 12.2. Under optimal conditions, 32 carbohydrates including mono-, di-, oligosaccharides, and sugar alcohols were separated in less than 12 min. The proposed method provided a good linearity, low limits of detection, and good repeatability of the carbohydrates. This method was then utilized to analyze carbohydrates in food samples. The results indicated that the developed method is an excellent alternative for the carbohydrate routine analysis in the food field.
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ELECTROCHIMICA ACTA
·
2012
·
IF 3.832
Xiaohui Wu,Xiaoting Hong,Zhiping Luo,K.S. Hui,Hongyu Chen,Junwen Wu,K.N. Hui,Laisheng Li,Junmin Nan,Qiuyun Zhang
Novel mesoporous carbon has been synthesized using rod-like nano-hydroxyapatite (HA) particles as templates, sucrose as carbon precursor by polymerizing, carbonizing and the removal of templates with HCl solution. In the process, HA not only acted as an endotemplate but also an exotemplate producing micropores and mesopores. Subsequently, mesoporous carbon was modified by HNO 3 solution with different concentration. The morphology, pore structure, and surface functional groups of the as-obtained samples are analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller method (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The electrochemical performance for electrochemical capacitors is evaluated in a 1 M H 2 SO 4 aqueous solution. The results manifest that the structrue of resultant carbon with a high surface area (719.7 m 2 g −1 ) and large pore volume (1.51 cm 3 g −1 ) is the replica of HA. After modification, the surface area and pore volume mesoporous carbons slightly decrease, while their electrochemical performance have been significantly improved with the increase of the capacitance from 125.7 to 170.1 F g −1 and a non-decayed cycle life over 5000 cycles for HA-C-0.15N.
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EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
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2015
·
IF 3.85
Xingwang Zhang,Tianpeng Zhang,Yanghuan Ye,Huaqing Chen,Hua Sun,Xiaotong Zhou,Zhiguo Ma,Baojian Wu
Systemic delivery of amphiphobic drugs (insoluble in both water and oil) represents a formidable challenge in drug delivery. This work aimed to engineer a functional mesoporous carbon material to efficiently load SNX-2112, an amphiphobic anticancer agent , and to evaluate its performance in tumor-targeting delivery. Hydrothermal reaction combined with high-temperature activation was used to fabricate glucose-based mesoporous carbon nanospheres (MCNs). SNX-2112-loaded MCNs stabilized by phospholipid (SN-PMCNs) were prepared by the absorption/solvent diffusion/high-pressure homogenization method. The obtained SN-PMCNs were 180 nm around in particle size, showing a high drug load (42.7%) and acceptable physical stability. SN-PMCNs demonstrated an enhanced in vitro antitumor effect and increased uptake into cancer cells in comparison with the formulation of SNX-2112 solution (SN-Sol). The in vivo antitumor effect and biodistribution in 4T1 xenograft tumor mice, a breast cancer model, were also significantly improved through SN-PMCNs. It was shown that specific clathrin-dependent and nonspecific caveolae-dependent endocytosis were involved in the cellular trafficking of SN-PMCNs. Glucose transporter-mediated transport, prolonged body residence time and improved biodistribution via EPR effect were the main mechanisms of enhanced antitumor effect. SN-PMCNs have presented excellent tumor targeting properties and should be a promising carrier to address the systemic delivery of SNX-2112.
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PubMed
高影响因子
FOOD SCIENCE AND BIOTECHNOLOGY
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2015
·Vol. 24
·期 3
·867-873
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IF 0.653
Niu Liying,Li Dajing,Liu Chunquan,Liu Fuguo
Lipoxygenases (LOX) in milk-stage sweet corn and waxy corn were extracted using a phosphate buffer (pH 7.0) and enzyme activities were determined using linoleic acid as a substrate. Michaelis constant ( K m) values, decimal reduction times (D value), temperature sensitivity parameters (Z value), and activation energies ( E a) were calculated. Enzymes from both corn types followed first-order inactivation kinetics within 0–25 min and 50–70°C. However, enzymes exhibited different pH profiles and affinities toward linoleic acid. Km values (4.34 and 1.40 mM for sweet corn and waxy corn, respectively), heat stability values, and Ea values (116.81 and 246.82 kJ/mol) were different. Waxy corn LOX was more heat stable below 65–C with a higher D value, but was more temperature sensitive with a lower Z value. The different characteristics suggested the presence of different isoenzymes and necessitated the use of different parameters for blanching.
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GREEN CHEMISTRY
·
2014
·Vol. 16
·期 5
·2490-2499
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IF 6.852
Jinzhu Chen,Kegui Li,Limin Chen,Ruliang Liu,Xing Huang,Daiqi Ye
A series of sulfonic acid-functionalized metal–organic frameworks (MOF-SO3H) were prepared by postsynthetic modification (PSM) of the organic linkers within the MOF with chlorosulfonic acid. The obtained MOF-SO3H, including sulfonic acid-functionalized MIL-101(Cr) [MIL-101(Cr)-SO3H], UIO-66(Zr) [UIO-66(Zr)-SO3H], and MIL-53(Al) [MIL-53(Al)-SO3H], have been systematically studied as solid acids in fructose transformation to 5-hydroxymethylfurfural (HMF). With MIL-101(Cr)-SO3H as catalyst, a HMF yield of 90% with a full fructose conversion was obtained at 120 °C for 60 min in DMSO. The concentration of –SO3H in MOF-SO3H as well as the contribution of Brønsted acidity of MOF-SO3H parallels its –SO3H grafting rate. Under a lower –SO3H grafting level, a good linear correlation between catalytic activity, in terms of turnover frequency, and sulfonic acid-site density of MOF-SO3H was found. Moreover, the sulfonic acid groups, which function as the catalytic sites, are equivalent in all MOF-SO3H for fructose-to-HMF transformation, regardless of precursor MOFs. Both conversions of fructose and selectivities towards HMF increase with the sulfonic acid-site density of MOF-SO3H at an initial stage of fructose-to-HMF transformation. Kinetics studies reveal that the MIL-101(Cr)-SO3H promoted fructose-to-HMF transformation may follow pseudo-first-order kinetics with observed activation energy of 55 kJ mol−1 under the investigated conditions. Moreover, MIL-101(Cr)-SO3H behaves as a heterogeneous catalyst and can be easily recovered and reused. The research highlights a good prospect for catalytic application of MOF-derived solid acid catalysts for biomass carbohydrate valorization.
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Journal of Functional Foods
·
2014
·
IF 4.48
Chun-Feng Guo,Jing-Yan Li
The effects of a Tween 80 and CaCl 2 mixture on the hypocholesterolemic activity of bile salt hydrolase (BSH)-active Lactobacillus casei F0422 were investigated in rats fed a cholesterol-rich diet for 3 weeks. This mixture significantly enhanced the hypocholesterolemic activity of strain F0422 in rats. The group administered drinking water supplemented with both strain F0422 and the Tween 80 and CaCl 2 mixture had significantly lower levels of total serum cholesterol, low-density lipoprotein cholesterol and total liver cholesterol than did the group administered drinking water supplemented only with strain F0422 or the Tween 80 and CaCl 2 mixture. The hypocholesterolemic activity of the combined strain F0422 and Tween 80 and CaCl 2 mixture was attributed to the increase in fecal bile acid excretion through enhancement of bile salt tolerance and BSH catalytic activity of strain F0422 by Tween 80 and up-regulation of the adhesion of strain F0422 to intestinal epithelial cells by CaCl 2 .
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International Journal of Chemical Engineering
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2014
·
IF 0
Hu Li,Song Yang
L-Proline derived ionic liquids (ILs) used as both solvent and catalyst were efficient for transformation of fructose and sucrose to 5-hydroxymethylfurfural (HMF) in the presence of water. Response surface methodology (RSM) was employed to optimize fructose dehydration process, and a maximum HMF yield of 73.6% could be obtained at 90°C after 50 min. The recycling of the IL exhibited an almost constant activity during five successive trials, and a possible reaction mechanism for the dehydration of fructose to HMF was proposed.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
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2013
·
IF 3.458
Yanzhuo Zhang,Zhizhuang Zhi,Xue Li,Jian Gao,Yaling Song
The main objective of this study was to develop carboxylated ordered mesoporous carbon microparticles (c-MCMs) loaded with a poorly water-soluble drug, intended to be orally administered, able to enhance the drug loading capacity and improve the oral bioavailability. A model drug, carvedilol (CAR), was loaded onto c-MCMs via a procedure involving a combination of adsorption equilibrium and solvent evaporation. The physicochemical properties of the drug-loaded composites were systematically studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and HPLC. It was found that c-MCM has a high drug loading level up to 41.6%, and higher than that of the mesoporous silica template. Incorporation of CAR in both drug carriers enhanced the solubility and dissolution rate of the drug, compared to the pure crystalline drug. After loading CAR into c-MCMs, its oral bioavailability was compared with the marketed product in dogs. The results showed that the bioavailability of CAR was improved 179.3% compared with that of the commercial product when c-MCM was used as the drug carrier. We believe that the present study will help in the design of oral drug delivery systems for enhanced oral bioavailability of poorly water-soluble drugs.
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METABOLIC ENGINEERING
·
2013
·
IF 6.859
Wei Du,Feiyan Liang,Yangkai Duan,Xiaoming Tan,Xuefeng Lu
Because cyanobacteria are photosynthetic, fast-growing microorganisms that can accumulate sucrose under salt stress, they have a potential application as a sugar source for the biomass-derived production of renewable fuels and chemicals. In the present study, the production of sucrose by the cyanobacteria Synechocystis sp. PCC6803, Synechococcus elongatus PCC7942, and Anabaena sp. PCC7120 was examined. The three species displayed different growth curves and intracellular sucrose accumulation rates in response to NaCl. Synechocystis sp. PCC6803 was used to examine the impact of modifying the metabolic pathway on the levels of sucrose production. The co-overexpression of sps ( slr0045 ) , spp ( slr0953 ), and ugp ( slr0207 ) lead to a 2-fold increase in intracellular sucrose accumulation, whereas knockout of ggpS ( sll1566 ) resulted in a 1.5-fold increase in the production of this sugar. When combined, these genetic modifications resulted in a fourfold increase in intracellular sucrose accumulation. To explore methods for optimizing the transport of the intracellular sucrose to the growth medium, the acid-wash technique and the CscB (sucrose permease)-dependent export method were evaluated using Synechocystis sp. PCC6803. Whereas the acid-wash technique proved to be effective, the CscB-dependent export method was not effective. Taken together, these results suggest that using genetic engineering, photosynthetic cyanobacteria can be optimized for efficient sucrose production.
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INTERNATIONAL DAIRY JOURNAL
·
2013
·
IF 2.333
C.F. Guo,J.Y. Li
Elevated serum cholesterol is a major risk factor for coronary artery disease. Probiotics may manage elevated cholesterol. The hypocholesterolaemic effects of Lactobacillus casei F0822 and its functional mechanisms were investigated in rats . The serum total cholesterol, low-density lipoprotein cholesterol and liver total cholesterol levels significantly decreased in rats fed a high-cholesterol diet plus drinking water supplemented with viable cells of strain F0822; however, there was no significant difference in the serum high-density lipoprotein cholesterol levels among the treatment groups. The hypocholesterolaemic mechanisms of strain F0822 were attributed to its ability to suppress the reabsorption of bile acids into the enterohepatic circulation though hydrolysis of conjugated bile acids in the small intestine, binding of deoxycholic acid and hyodeoxycholic acid in the large intestine, and increase in propionate:acetate ratio in the large intestine in rats. Strain F0822 may be a promising probiotic culture with potential hypocholesterolaemic action in human.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2014
·Vol. 95
·期 11
·2228-2236
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IF 1.879
Pei-Hong Fan,Mei-Tong Zang,Jie Xing
BACKGROUND As probiotics, soy oligosaccharides have become popular as healthy foods to reduce disease risk. However, comprehensive information about oligosaccharides in different food legumes is limited. RESULTS In this study, eight oligosaccharides were well detected and quantified in different varieties of eight legume species using high-resolution mass spectrometry. It was determined that species could be distinguished by total content of oligosaccharides and their distribution modes. Among the studied species, Vigna unguiculata is a better resource of non-digestible oligosaccharides, while Vicia faba and black soybean ( Glycine max ) are at a disadvantage. Normally, stachyose predominates in non-digestible oligosaccharides, except in mung bean and broad bean, where verbascose predominates. For mung bean and green soybean, the seed coat should be taken into account for oligosaccharide consumption. The developed high-resolution mass spectrometry method greatly simplified the sample preparation process and permitted the identification of oligosaccharides without reference compounds. CONCLUSION This work involved extensive sample collecting and provided useful information for consumers. The developed method may be useful for rapid quantification of oligosaccharides in related foods. © 2014 Society of Chemical Industry
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