Optimization of Synthesis of Spherical Lignosulphonate Resin and Its Structure Characterization

Calcium lignosulphonate was used to synthesize a spherical lignosulphonate resin in a cheap and non-toxic disperse medium by reversed phase suspension polymerization. The process conditions were optimized by orthogonal experiments. Under .the optxmal conditxons （T=95 ℃, CHCl= 3 mol·L^-1, mHCHO： mCLS=7%, WCLS=50%）, globulation took about 20 min and the product was featured with excellent spherical shape, narrow particle size range, 61.20% of water retention capacity, 0.83 mmol·ml^- 1 of total volume exchange capacity and 3.46 mmol·g^- 1 of total exchange capacity. The results of Scanning Electron Micrograph and Scanning Probe Micrograph indicate that spherical lignosulphonate resin has a rugged surface with porous microstructure in the gel skeleton. The average pore size of dry samples was determined to be 10.46 nm. by the BET method.

Effect of Limited Enzymatic Hydrolysis on Structure Characterization of Glycinin

[ Objective] This study aimed to characterize the structure of soybean glycinin affected by limited enzymatic hydrolysis. [ Method ] The glycinin was limitedly hydrolyzed by alkaline protease; then the SDS-polyacrylamide gel electrophoresis （SDS-PAGE）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （fTIR） and other means were performed to characterize the glyeinin structure changing during the hydrolysis process. [ Result] SDS-PAGE analysis showed that the subunit contem of glycinin significantly decreased after hydrolysis, and acidic subunits were more susceptible to hydrolysis than alkaline subunits. The scanning electron microscopy revealed that the structure of glycinin powder changed greatly after hydrolysis. The I^TIR results showed that the propor- tions of all conformations of glycinin changed greatly during hydrolysis process. In addition, the protein hydrophobicity and sulfhydryl content were also significantly influenced by hydrolysis. [ Conclusion] The enzymatic hydrolysis greatly changed the conformations of glyeinin, and the change was dependent on the degree of hy- drolysis.

Bio-soft matter derived from traditional Chinese medicine:Characterizations of hierarchical structure,assembly mechanism,and beyond

Structural and functional explorations on bio-soft matter such as micelles,vesicles,nanoparticles,aggregates or polymers derived from traditional Chinese medicine(TCM)has emerged as a new topic in the field of TCM.The discovery of such cross-scaled bio-soft matter may provide a unique perspective for unraveling the new effective material basis of TCM as well as developing innovative medicine and biomaterials.Despite the rapid rise of TCM-derived bio-soft matter,their hierarchical structure and assembly mechanism must be unambiguously probed for a further in-depth understanding of their pharmacological activity.In this review,the current emerged TCM-derived bio-soft matter assembled from either small molecules or macromolecules is introduced,and particularly the unambiguous elucidation of their hierarchical structure and assembly mechanism with combined electron microscopic and spectroscopic techniques is depicted.The pros and cons of each technique are also discussed.The future challenges and perspective of TCM-derived bio-soft matter are outlined,particularly the requirement for their precise in situ structural determination is highlighted.

Structural characterization of three acidic polysaccharides from Opuntia dillenii Haw.fruits and their protective effect against hydrogen peroxide-induced oxidative stress in Huh-7 cells

Three novel acidic polysaccharide fractions(OFPP-1,OFPP-2,OFPP-3)with different m olecular weights(803.7,555.1 and 414.5 k Da)were isolated from the peeled Opuntia dillenii Haw.fruits by alkali-extraction,graded alcohol precipitation and column chromatography.Structural analysis indicated that OFPPs were pectic polysaccharides consisting of rhamnose,arabinose and galactose residues.The backbone of OFPP-1 consisted of a repeating unit→6-α-D-Galp A-(1→2)-α-L-Rhap-(1→with T-α-D-Galp A-(1→6)-α-D-Galp A-(1→4)-α-D-Glcp-(1→,T-β-D-Xylp-(1→6)-α-D-Galp A-(1→4)-α-D-Glcp-(1→or T-α-D-Galp A-(1→3)-α-L-Araf-(1→as the side chains.The backbone of OFPP-2 consisted of a disaccharide repeating unit→2)-α-L-Rhap-(1→4)-β-D-Galp A-(1→with T-β-L-Araf-(1→as the branches substituted at the O-4 position of→2,4)-α-LRhap-(1→.Whereas the backbone of OFPP-3 was→2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-β-L-Araf-(1→or→2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→4)-β-D-Galp A-(1→,which was branched at the O-4 position of→2,4)-α-L-Rhap-(1→.Moreover,these three polysaccharide fractions could protect Huh-7 cells against H2O2-induced oxidative stress to different extents by decreasing the MDA content and increasing the SOD,CAT,GSH-Px activities and the GSH level in the Huh-7 cells.These results suggest that OFPPs have the potential to be used as natural antioxidants.

Structural characterization and anti-inflammatory activities of novel polysaccharides obtained from Pleurotus eryngii

Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present study.Results showed that molecular weights of these polysaccharides were 3235,2041 and 23933 Da,respectively.Further,structural characterization revealed that PEP-0.1-1 had a→4-α-D-Glcp-1→backbone and contained→4)-α-D-Glcp and→4)-β-D-Glcp reducing end groups.PEP-0-1 backbone contained→4-α-D-Glcp-1→and→6-α-3-O-Me-D-Galp-1→,and the side chains containedα-D-Glcp,β-D-Manp-1→andα-D-Glcp-3→.However,PEP-0-2 backbone consisted of→4-α-DGlcp-1→and→6-α-3-O-Me-D-Galp-(1→6)-α-D-Galp-1→while the side chains containedα-D-Glcp andβ-D-Manp-1→.Biological activity analysis was then carried out and found that all these polysaccharides could significantly suppress the relative mRNA expression of toll-like receptor 4,nitric oxide(NO),tumor necrosis factor-α,interleukin(IL)-1βand IL-6 in lipopolysaccharide(LPS)-induced inflammation of RAW264.7 cells,as well as the over secretion of the above cell cytokines.Moreover,Western blotting analysis revealed that all these purified fractions displayed significant inhibition effects on the expression of c-Jun N-terminal kinases protein induced by LPS in mitogen activated protein kinase pathway,along with the relieving on the inhibition effect of LPS on IκB-αprotein expression.In summary,the information generated by the present study could provide a theoretical basis for the exploration of novel healthy food materials from edible mushroom with antiinflammation activities.

Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

Solvothermal Synthesis and Characterization of [TM(1,2-dap)3]HgSb2Se5(TM = Co,Fe)with a Chain Structure

One organic-decorated quanternaery [TM（1,2-dap）3]Hg Sb2Se5（1,2-dap = 1,2-dianinopropane, TM = Co（1）, Fe（2）） compound has been solvothermally synthesized. The compounds crystallize in triclinic space group P 1, with a = 11.248（6）, b = 11.542（7）, c = 12.180（12） A, V =1268.7（16） A^3, Z = 2, F（000） = 1010 for 1 and a = 11.311（5）, b = 11.558（5）, c = 12.180（9） A, V =1276.5（12） A^3, Z = 2, F（000） = 1008 for 2. The crystal structure consists of one-dimensional anionics chains composed of Hg Se4 tetrahedra and SbSe3 trigonal pyramids sharing corners and[TM（dap）3]^2＋ cations. The [HgSb2Se＋5^2-]∞ anionic chains run along the [001] direction, and are surrounded by the [TM（dap）3]^2＋ cations. Meanwhile, 8-ring [Hg2Sb2Se4] and 6-ring [HgSb2Se2] are alternately found. The compounds were structurally characterized by elemental analysis,thermogravimetric analysis, infrared spectroscopy and UV-Vis diffuse reflectance spectroscopy.

Structure elucidation and in vitro rat intestinal fermentation properties of a novel sulfated glucogalactan from Porphyra haitanensis

This study was to investigate the structure and rat fecal microbial fermentation properties of a polysaccharide fraction(PHP2)isolated from the red marine alga Porphyra haitanensis.PHP2 was characterized as a sulfated glucogalactan,with a hypothetical backbone structure of→4)Gα(1→6)G4 Sβ(1→4)Glc(1→and a side chain of Man(1→6)Glc.PHP2 had an irregular spherical chain conformation.The 16 S r RNA sequence analysis revealed that PHP2 modulated the rat fecal micro-flora composition,with a similar effect to inulin,changing the dominant genus(Lactobacillus and Escherichia-Shigella)and promoting the growth of organisms that degrade sulfur-containing polysaccharides,such as Desulfovibrio,Ruminococcaceae_UCG-005,and Ruminococcus_2.PHP2 can promote production of acetic,propionic and butyric acid by rat fecal micro-flora.Prediction of metabolic function suggested that PHP2 could modulate cholesterol metabolism.The sulfated glucogalactan fermentation behavior may be associated with its monosaccharide composition,chain branching and chain conformation.PHP2 appeared to have considerable potential as functional food,and was associated with sulfur-containing polysaccharides in general.

Micro-and Nano-structure Characterization of Isotropic Pyrocarbon Obtained via Chemical Vapor Deposition in Hot Wall Reactor

The hot wall reactor was used to deposit isotropic pyrocarbon. The density of the product was measured by Archimedes method. The fracture morphology and texture of the product were investigated by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Raman spectroscopy was also applied to characterizing the structure of the product. The results show that the density of the product is about 1.31 g/cm^3. The pyrocarbon consists of granular particles with the size of about 1.5 μm under SEM images. Under TEM images, the pyrocarbon is composed of irregular grains and onion-like particles are also detected. The orientation angle （180 deg.） of pyrocarbon reveals its isotropic character. The ID/IG ratio in Raman spectrum is about 1.2, indicating the isotropic feature of the product qualitatively.

A facile method for fabrication of nano-structured Ni-Al_2O_3 graded coatings: Structural characterization

Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings were fabricated using powdermixtures with a wide range of Ni/Al2O3mass ratio varying from1:1to plain Ni.XRD,SEM and TEM techniques were employed tostudy the structural characteristics of the coatings.It was found that the composition of the starting mixture strongly affects the Al2O3content and the microstructure of the final coating.Mixtures containing higher contents of Al2O3yield higher volume fractions of theAl2O3particles in the coating.Though Ni-Al2O3composite coatings with about50%of Al2O3particles were successfully deposited,well-compacted and free of cracks and/or voids coatings included less than20%(volume fraction)of Al2O3particles which weredeposited from powder mixtures with Ni/Al2O3mass ratios of4:1or higher.Moreover,mechanical and metallurgical bondings arethe main mechanisms of the adhesion of the coating to the Al substrate.Finally,functionally graded composite coatings withnoticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions.

Characterization of Interface State Density of Ni/p-GaN Structures by Capacitance/Conductance-Voltage-Frequency Measurements

For the frequency range of I kHz-lOMHz, the interface state density of Ni contacts on p-GaN is studied using capacitance-voltage （C-V） and conductance-frequency-voltage （G-f-V） measurements at room temperature. To obtain the real capacitance and interface state density of the Ni/p-GaN structures, the effects of the series resistance （Rs） on high-frequency （SMHz） capacitance values measured at a reverse and a forward bias are investigated. The mean interface state densities obtained from the CHF-CLF capacitance and the conductance method are 2 ×1012 e V-1 cm-2 and 0.94 × 1012 eV-1 cm-2, respectively. Furthermore, the interface state density derived from the conductance method is higher than that reported from the Ni/n-GaN in the literature, which is ascribed to a poor crystal quality and to a large defect density of the Mg-doped p-GaN.

A DIACETYLENE CONTAINING α-NITRONYL NITROXIDE——SYNTHESIS,CRYSTAL STRUCTURE AND MAGNETIC CHARACTERIZATION

The mono-α-nitronyl nitroxide substituted diacetylene was synthesized and its structure was established by EA,FAB-MS,IR,ESR and x-ray diffraction analysis.Using the Extracting Sample Magnetometer,its magnetic properties was investigated,and the results indicate that this compound possesses antiferromagnetic properties.

STUDY ON SYNTHESIS,CHARACTERIZATION AND STRUCTURE OF A NEW RARE EARTH COORDINATION COMPOUND WITH BENZOIC ACID

In this paper,a new rare earth benzoate coordination compound,[TbL_3(HL)(H_2O)]_2 (HL=C_7H_6O_2=benzoic acid) is synthesized and characterized by elemental analysis DTA,TG,DTC,and IR spectra.The title compound crystallizes in triclinic,space.group P with a=9.148(1),b=11.460(2), c=13.506(2);α=112.76(1),β=91.83(1),γ=91.99(1)°;Z=1;V=1303.3.The final R factor is 0.0235.The rare earth ion is nine-coordinated to form a distorted monocapped square antiprism.

SYNTHESIS,CHARACTERIZATION AND CRYSTAL STRUCTURES OF η~5-CH_3C_5H_4)M(CO)_2NO AND(η~5-CH_3C_5H_4)M(μ_3-NH)(μ_2-NO)(μ_2-CO)Fe_2(CO)_6(M=Mo or W)

Synthesis of complexes（η;-CH;C;H;）M（CO）;NO（M=Mo,I;M=W,II）and clusters（η;-CH;C;H;）M（μ;-NH）(μ;-NO) （μ;-CO）Fe;（CO）;（M=Mo,III:M=W,IV）,based on the reaction of （η;-C5;）M（CO）;Cl with Na[Fe（CO）;NO] at room tem-perature,have been demonstrated,The crystal structures of II and IV arealso presented.

Structural characterizations andα-glucosidase inhibitory activities of four Lepidium meyenii polysaccharides with different molecular weights

Four polysaccharides(MCPa,MCPb,MCPc,MCPd)were obtained from Lepidium meyenii Walp.Their structures were characterized by chemical and instrumental methods including total sugar,uronic acid and protein content determi-nation,UV,IR and NMR spectroscopy,as well as monosaccharide composition determination and methylation analy-ses.Four polysaccharides were a group of glucans with different molecular weights ranging from 3.12 to 14.4 kDa,and shared a similar backbone chain consisting of(1→4)-glucose linkages with branches attached to C-3 and C-6.Furthermore,bioactivity assay showed that MCPs had concentration-dependent inhibitory activity onα-glucosidase.MCPb(Mw=10.1 kDa)and MCPc(Mw=5.62 kDa)with moderate molecular weights exhibited higher inhibitory activ-ity compared with MCPa and MCPd.

Structural characterization and immunostimulatory activity of a water-soluble polysaccharide from abalone(Haliotis discus hannai Ino)muscle

A water-soluble polysaccharide from abalone muscle(AMPP)was isolated.The contents of carbohydrate,protein,uronic acid,and sulfate in AMPP were 83.5%,0.5%,2.7%,and 2.6%,respectively.High-performance liquid chromatography analysis indicated that AMPP was homogeneous and had an average molecular weight of approximately 3.2 kDa.The main monosaccharides of AMPP were glucose(Glc)and mannose with a molar ratio of 99.7:0.3.The structural characteristics of AMPP were elucidated through methylation analysis,Fourier transform infrared spectroscopy,and nuclear magnetic resonance spectroscopy.The linkages of AMPP consisted of terminal,1,4-linked,1,6-linked,and 1,4,6-linked Glcp with a molar ratio of 3.1:7.2:1.0:2.5.In one repeat unit of the proposed AMPP structure,the backbone chain was composed of eight 1→4 glycosidic bonds and one 1→6 glycosidic bond,with three branch chains linked by 1→6 glycosidic bond.In addition,AMPP was found to possess potent immunostimulatory activity via rising phagocytosis of RAW264.7 cells and promoting secretion of TNF-α.

Research Progress on Structure and Bioactivity of Longan Polysaccharide

Longan originates from southern China and has high nutritional and health value.Recent phytochemistry and pharmacology studies have shown that polysaccharides are a main bioactive component of longan.Longan polysaccharides possess antioxidant,anti-aging,anti-tumor,immunomodulatory,and other bioactivities.Hot-water extraction,ethanol precipitation,and ultrasonic extraction are generally used to extract water-soluble longan polysaccharides.However,the relationship between the structure and bioactivity of longan polysaccharides remains unclear,requiring further investigation.The aim of this review is to evaluate the current literature focusing on the extraction,purification,structural characterization,and biological activity of longan polysaccharides.We believe that this review would provide a useful bibliography for further innovation and a basis for using longan polysaccharides in functional food.

Physicochemical, structural characterization, and antioxidant activities of chondroitin sulfate from Oreochromis niloticus bones

In this study,chondroitin sulfate was extracted from Oreochromis niloticus bones(OCS)and isolated to three fractions(OCS-1,OCS-2,and OCS-3).The physicochemical properties and structure characterization including monosaccharide,disaccharide compositions,molecular weight(Mw)of OCS were determined by HPAEC,HPLC-SAX,HPGPC,FT-IR spectra,and 1D/2D NMR.Moreover,their thermal properties,crystalline structure,and microstructure were also analyzed.Results showed that their Mw were between 10 kDa and 50 kDa.CS-6 was the predominant disaccharide unit in four OCS,and the CS-4/CS-6 ratios were close to CS from shark cartilage.Besides,the results of antioxidant activity showed that different fractions of OCS had a distinct DPPH radical,hydroxyl radical,and ABTS+radical scavenging activity.OCS-1 has the highest scavenging activities in DPPH and hydroxyl radical compared with other fractions,which showed a higher medicinal value.Those findings may lay some theoretical basis for the potential application development of OCS.

Catalytic Performance and Characterization of Anatase TiO_(2) Supported Pd Catalysts for the Selective Hydrogenation of Acetylene

Anatase TiO_(2)nanospindles containing 89%exposed{101}facets(TIO_(2)-101)and nanosheets with 77%exposed{001}facets(TiO_(2)-001)were hydrothermally synthesized and used as supports for Pd catalysts.The effects of the TiO_(2)materials on the catalytic performance of Pd/TiO_(2)-101 and Pd/TiO_(2)-001 catalysts were investigated in the selective hydrogenation of acetylene to polymer-grade ethylene.The PdfTiO_(2)-101 catalyst exhibited enhanced performance in terms of acetylene conversion and ethylene yield.To understand these effects,the catalysts were characterized by H_(2)temperature-programmed desorption(H_(2)-TPD),H_(2)temperature-programmed reduction(H=-TPR),transmission electron microscopy(TEM),pulse CO chemisorption,X-ray photoelectron spectroscopy(XPS),and thermogravimetric analysis(TGA).The TEM and CO chemisorption results confirmed that Pd nanoparticles(NPs)on the TiO_(2)-101 support had a smaller average particle size(1.53 nm)and a higher dispersion(15.95%)than those on the TiO_(2)-001 support(average particle size of 4.36 nm and dispersion of 9.06%).The smaller particle size and higher dispersion of Pd on the Pd/TiO_(2)-101 catalyst provided more reaction active sites,which contributed to the improved catalytic activity of this supported catalyst.

Production, structure, and bioactivity of polysaccharide isolated from Tremella fuciformis

Tremella fuciformis polysaccharide(TFP) is an important bioactive substance in T. fuciformis, which contributes to its application as medicine and food. In the present work, TFP was extracted with enzymatic combined with wet beating and its physicochemical as well as biological activities were investigated in the study. The result showed that the purity of TFP1 reached 92.14%(m/m). The TFP1, purified by DEAE column, had a molecular weight(Mw) of 5.8 × 10^(3) k Da and consisted mainly of mannose, xylose, fucose, glucose and glucuronic acid at a molar ratio of 1.91 : 0.1 : 2.49 : 6.23 : 0.95. The structure of TFP1 was preliminarily investigated by infrared spectroscopy, nuclear magnetic resonance and atomic force microscope(AFM) analysis. Moreover, the antioxidant assays showed that TFP1 could scavenge DPPH, ABTS+ and hydroxyl radicals. The excellent water holding capacity of TFP1 implied its application in the food, pharmaceutical andcosmetic industries.