Catalysts
·
2020
·Vol. 10
·期 2
·143
·
IF 3.52
Chengxiong Wang,Dezhi Ren,Junchen Du,Qinggao Qin,Aimin Zhang,Li Chen,Hao Cui,Jialin Chen,Yunkun Zhao
Ceria-modified Pt/Al2O3catalyst has been commonly prepared by the impregnation of platinum on ceria-modified alumina and widely applied in the chemical industry and automotive industry. The in situ diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), and thermogravimetric (TG) analysis techniques were employed to investigate the typical mechanisms of the bis(ethanolammonium)hexahydroxyplatinate(IV) and cerium nitrate decomposition catalyzed by Ptδ+species for the facile synthesis of CeO2-Pt/Al2O3catalyst. It was found that Pt4+-catalyzed decomposition of cerium nitrate leads to the higher dispersity of ceria and forming more active oxygen species, on the basis of X-ray diffraction (XRD) and H2temperature-programmed reduction (H2-TPR) results. The in situ activity measurements were also performed to investigate the reaction mechanisms and the specific activities for the catalytic CO, NO, C3H6and C3H8co-oxidation. The results indicate that undesirable N2O by-product is formed by the selective catalytic reduction (SCR) of NO by C3H6below 350 °C. The cerium addition effectively improves the activity of catalytic oxidation, but exhibits an increased N2O yield, due to the increased reducibility.Keywords:platinum;ceria;in situ characterization;catalytic oxidation
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 8
·3184
·
IF 3.4
Yan Qian,Zeen Huang,Guantao Zhou,Chenan Chen,Yuhang Sang,Zuolong Yu,Legao Jiang,Yuning Mei,Yunxiao Wei
This study investigates the montmorillonite (MMT) content, rotational viscosity, and colloidal index of sodium montmorillonite (Na-MMT) as a function of the sodium agent dosage, reaction time, reaction temperature, and stirring time. Na-MMT was modified using different octadecyl trimethyl ammonium chloride (OTAC) dosages under optimal sodification conditions. The organically modified MMT products were characterized via infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results show that the Na-MMT with good properties (i.e., the maximum rotational viscosity and highest Na-MMT content with no decrease in the colloid index) was obtained at a 2.8% sodium carbonate dosage (measured based on the MMT mass), a temperature of 25 °C, and a reaction time of two hours. Upon organic modification of the optimized Na-MMT, OTAC entered the NA-MMT interlayer, and the contact angle was increased from 20.0° to 61.4°, the layer spacing was increased from 1.58 to 2.47 nm, and the thermal stability was conspicuously increased. Thus, MMT and Na-MMT were modified by the OTAC modifier.Keywords:montmorillonite;organic modification;characterization;property
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
POLYMER SCIENCE SERIES B
·
2016
·Vol. 58
·期 5
·594-600
·
IF 0.737
Wang Yan,Wei Nuo,Feng Qingling,Li Sha,Yang Chang,Liu Zhiqiang,Zhang Wenming,Li Qing
Novel luminescent bio-based hydrogels comprising cellulose and Y 4 Si 2 O 7 N 2 :Ce 4+ (YC) were prepared in an alkali/urea aqueous system using epichlorohydrin as a cross-linker. The structure, characteristics and properties of the hydrogels were investigated by various techniques, including FTIR spectroscopy, wideangle X-ray diffraction, scanning electron microscopy, etc. The results showed that when the content of YC was less than 0.05 g, the YC particles were tightly embedded in the macro porous of cellulose matrix, which not only supplied cavities for YC immobilization, but also supplied the pore wall to protect the structure and character of YC. Hence, the cellulose–YC hybrid hydrogels exhibited strong cyan fluorescence under a UV lamp. However, excess of YC particles were enshrouded in the cellulose matrix resulted in smaller pores, weaker fluorescence intensity, lower swelling ratio and higher mechanical properties.
研究领域:
材料科学
·
生物材料
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Jian Zhao,Jiahuan Xu,Lingxi Li,Baoshan Sun
Polymeric polyphenols in different parts (fruits, leaves and calyces) of persimmon ( Diospyros kaki L. cv. Mopan) were characterized via four different degradation methods, followed by HPLC/UPLC-UV/vis, HPLC/UPLC-Q-Exactive-Orbitrap/MS and UPLC-QqQ/MS to obtain comprehensive structural constituent unit information of polymeric polyphenols. The results indicated that persimmon polymeric polyphenols not only consisted of proanthocyanidins as terminal and extension units, but also contained anthocyanidins, flavonols and phenolic acids as terminal units. Among these different fragments detected, (−)-gallocatechin, (−)-gallocatechin-3- O -gallate, (+)-catechin and (+)-catechin-3 -O- gallate as extension units and (−)-epicatechin, (−)-gallocatechin, (−)-epigallocatechin, eight phenolic acids and four flavonols as terminal units were found for the first time in persimmon polymeric polyphenols. The molar percentages of constitutive units of persimmon polymeric polyphenols varied considerably. Compared to polymeric polyphenols in persimmon fruits and calyces, anthocyanidins, flavonols and phenolic acid units with the highest molar percentages were found in polymeric polyphenols in persimmon leaves. In contrast, the mean polymerization degrees of polymeric polyphenols in persimmon fruits, leaves and calyces were 26.45 ± 0.43, 6.23 ± 0.08 and 11.60 ± 0.07, respectively. These findings provide, for the first time, comprehensive structural information on persimmon polymeric polyphenols, and offer valuable insights into their composition and characteristics.
研究领域:
食品科学
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植物化学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2021
·Vol. 10
·期 10
·2357
·
IF 4.35
Fei Li,Solju Pak,Jing Zhao,Yunlu Wei,Yuyu Zhang,Quanhong Li
A neutral pumpkin polysaccharide (NPPc) was extracted fromCucurbia moschataand its structural characterization is performed. Moreover, uptake behaviors of an NPPC were investigated at the cellular level. The results showed that NPPc, an average molecular weight (Mw) of 9.023 kDa, was linear (1→4)-α-D-Glcpresidues in the backbone, which branched point atO-6 position of (1→4,6)-α-D-Glcp. The side chain contained (1→6)-α-D-Glcpand terminal glucose. The cellular uptake kinetics results showed that the uptake of fluorescent-labeled NPPc was in time- and dose-dependent manners in Caco-2 cells. For subcellular localization of NPPc, it was accumulated in endoplasmic reticulum and mitochondrion. This study illustrates the characteristics on the uptake of NPPc and provides a rational basis for the exploration of polysaccharides absorption in intestinal epithelium.Keywords:Cucurbia moschata;polysaccharide;structural characterization;uptake characteristic
研究领域:
食品科学
·
营养学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2014
·
IF 3.107
Qiang Zhang,Jian Xiao,Qing-Qing Sun,Jian-Chun Qin,Gennaro Pescitelli,Jin-Ming Gao
Bioassay-guided fractionation of the fermentation extract of Xylaria sp. XC-16, an endophyte from Toona sinensis led to the isolation of two new cytochalasans cytochalasin Z27, 1, and cytochalasin Z28, 2, along with three known compounds seco-cytochalasin E, 3, and cytochalasin Z18, 4, and cytochalasin E, 5. The structures of 1 and 2 were elucidated by spectroscopic and electronic circular dichroism methods. Compound 5 was shown to be potently cytotoxic against brine shrimp (LC50 = 2.79 μM), comparable to that of the positive agent toosendanin (LC50 = 4.03 μM), and also exhibited potential phytotoxic effects on Lactuca sativa and Raphanus sativus L. seedlings, which are higher than that of the positive control glyphosate. Additionally, the fungicidal effect of 2 against the phytopathogen Gibberella saubinetti was better than that of hymexazol. This is the first report of the three types of cytochalasins present in genus Xylaria. A structure–phytotoxicity activity relationship is also discussed.
研究领域:
真菌学
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天然产物化学
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植物病理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food & Function
·
2021
·Vol. 12
·期 14
·6626-6636
·
IF 5.396
Ji Liu,Tianyu Li,Haiyun Chen,Qian Yu,Chunyan Yan
Polygonatum sibiricum Red., a kind of edible and medicinal plant, has a long history of use in traditional Chinese medicine and as a nutritional food additive. Water-soluble crude polysaccharide (PS50) was obtained from P. sibiricum rhizome. After deproteinization and dialysis, PS50 was isolated and purified via DEAE-52 cellulose and Sephadex G-75 gel filtration chromatography to obtain two novel polysaccharides (PSP50-2-1 and PSP50-2-2). Chemical analysis and nuclear magnetic resonance (NMR) studies indicated that PSP50-2-1 was composed of β-D-Glcp-(1→, →2)-β-D-Galp-(1→, →2,6)-β-D-Galp-(1→, β-D-Fruf-(2→, and PSP50-2-2 was composed of β-D-Glcp-(1→, β-D-Galp-(1→, →2)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →2,6)-β-D-Galp-(1→, β-D-Fruf-(2→. The morphological analysis suggested that PSP50-2-1 and PSP50-2-2 both had a rough surface with cracks. Pharmacological studies showed that PSP50-2-2 at concentrations of 2.59 and 5.19 μM significantly promoted the differentiation and mineralization of MC3T3-E1 cells in vitro, which indicated that PSP50-2-2 had a function of osteogenic activity. Above all, this study provides evidence that PSP50-2-2 may be used as an anti-osteoporotic agent, with applications in health-care and pharmaceutical industries.
研究领域:
药理学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 7
·1365
·
IF 3.06
Qianyun Fu,Guoyun Li,Chen Wang,Ya Wang,Qinying Li,Jiejie Hao,Guangli Yu
Intestinal mucins constitute the major component of the mucus covering the epithelium of the gastrointestinal tract, thereby forming a barrier against microbial colonization. Rabbits are bred in large numbers worldwide, with little known about intestinalO-glycosylation despite this insight being crucial to the understanding of host-pathogen interactions. In the present study, a major mucin-type glycopeptide (RIF6) of hyla rabbit intestine was isolated and theO-glycans were extensively characterized based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with bioinformatics approaches. Thirty-threeO-glycans were identified, and most of them were sulfated or sialylated glycans. It was worth noting that Neu5Gc-containing structures within sialylatedO-glycans accounted for 91%, which were extremely different from that of other species including humans, mice, chickens, etc. Sulfated glycans accounted for 58%, unique disufated and sulfated-sialylated glycans were also detected in rabbit intestinal mucin. These structural characterization reflected species diversity and may provide deeper insights into explaining the adaptability of hyla rabbit to the environment.Keywords:Hyla rabbit intestinal mucin;O-glycan;Neu5Gc;structural characterization
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2016
·Vol. 17
·期 7
·1011
·
IF 3.257
Juncheng Chen,Shan Tian,Xiaoying Shu,Hongtao Du,Na Li,Junru Wang
A response surface and Box-Behnken design approach was applied to augment polysaccharide extraction from the residue ofRhizoma gastrodiae. Statistical analysis revealed that the linear and quadratic terms for three variables during extraction exhibited obvious effects on extraction yield. The optimum conditions were determined to be a liquid-to-solid ratio of 54 mL/g, an extraction temperature of 74 °C, an extraction time of 66 min, and three extractions. These conditions resulted in a maximumRhizoma gastrodiaepolysaccharide (RGP) extraction yield of 6.11% ± 0.13%. Two homogeneous polysaccharides (RGP-1a and RGP-1b) were obtained using DEAE cellulose-52 and Sephadex G-100 columns. The preliminary characterization of RGP-1a and RGP-1b was performed using HPLC-RID, HPGPC, and FTIR. Tests of the immunological activityin vitroshowed that the two polysaccharides could significantly stimulate macrophages to release NO and enhance phagocytosis in a dose-dependent manner. In particular, RGP-1b (200 μg/mL) and LPS (2 μg/mL) had almost the same influence on the NO production and phagocytic activity of RAW 264.7 macrophages (p> 0.05). All the data obtained indicate that RGP-1a and RGP-1b have the potential to be developed as a health food.Keywords:Rhizoma gastrodiae;polysaccharides;optimized extraction;characterization;immunological activity
研究领域:
植物化学
·
免疫学
✓ 已验证
DOI
PubMed
高影响因子
Marine Drugs
·
2020
·Vol. 18
·期 10
·492
·
IF 4.073
Jiawen Zhao,Kening Jiang,Yixuan Chen,Juan Chen,Yangfan Zheng,Huilin Yu,Jiajin Zhu
Antarctic krill oil is high in nutritional value and has biological functions like anti-inflammation and hypolipidemic effects. But it has and unpleasant smell, and unsaturated fatty acids are prone to oxidative deterioration. Its high viscosity and low solubility in water make it difficult for processing. Microemulsion can be a new promising route for development of krill oil product. We determined a formula of krill oil-in-water microemulsion with krill oil: isopropyl myristate = 1:3 as oil phase, Tween 80:Span 80 = 8:2 as surfactant, ethanol as co-surfactant and the mass ratio of surfactant to co-surfactant of 3:1. After screening the formula, we researched several characteristics of the prepared oil-in-water microemulsion, including electrical conductivity, microstructure by transmission electron microscope and cryogenic transmission electron microscope, droplet size analysis, rheological properties, thermal behavior by differential scanning calorimeter and stability against pH, salinity, and storage time.Keywords:microemulsion;Antarctic krill oil;formula selection;characterization
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Lin Yue,Jingru Li,Wanwen Chen,Xiaoli Liu,Qixing Jiang,Wenshui Xia
The novel derivatives of geraniol grafted chitosan oligosaccharide were synthesized via substitution and deprotection reaction, respectively. The products were identified by Fourier transform infrared (FT-IR), 1 H nuclear magnetic resonance (NMR), X-ray diffraction analysis (XRD), Thermogravimetric analysis (TGA) and UV–vis absorption spectroscopy. It is revealed that the derivatives exhibited a good solubility, thermal stability and antibacterial properties.
研究领域:
生物材料学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Bioactive Carbohydrates and Dietary Fibre
·
2021
·
IF 0
Lu-Yao Ma,Rou Xu,Hai-Feng Lin,Ming-Yong Xie,Shao-Ping Nie,Jun-Yi Yin
In this study, okra ( Abelmoschus esculentus (Linn.) Moench) pods (pericarp) obtained after removing seeds and flesh were applied for polysaccharide extraction. The 60 °C water extract polysaccharide (OPW-60) was obtained from okra peel at 60 °C, and then 100 °C water extract polysaccharide (OPW-100) was obtained from the residue at 100 °C. Acid extraction at 60 °C was finally used to obtain the polysaccharide by acid leaching at 60 °C (OPA-60). Then, structural characteristics and antioxidant activities investigations were performed on the extracted polysaccharides. The results showed that monosaccharide composition of three polysaccharides was different. OPW-60 was mainly type I rhamnogalacturonan (RG-I) pectin, while OPW-100 and OPA-60 consist of RG-I and homogalacturoan (HG) pectins. 1 H NMR analysis confirmed the existence of rhamnose and acetyl group among them. The structure diversity resulted in the difference of viscosity, molecular weight, surface morphology and antioxidant activities. OPW-60 exhibited the highest apparent viscosity, which might be attributed to the differences in molecular weight distribution and monosaccharide composition. OPW-60 was most effective in scavenging 2,2-Diphenyl-1-picrylhydrazyl radicals and chelating ferrous ion ability, while OPW-100 exhibited the highest hydroxyl radical scavenging activity. The results showed that polysaccharides with different structure and antioxidant ability could be obtained from okra under different extraction conditions.
研究领域:
食品科学
·
生物化学
·
植物学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）