scholarly journals Purification, Characterization of Two Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine and Their Anti-Inflammatory Effects on Mucus Secretion of Airway Epithelium

2019 ◽  
Vol 20 (14) ◽  
pp. 3553 ◽  
Author(s):  
Meibian Hu ◽  
Yujie Liu ◽  
Li Wang ◽  
Jiaolong Wang ◽  
Lin Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Interferon Γ ◽  
Sem Analysis ◽  
Exchange Chromatography ◽  
Mucus Secretion ◽  
Interleukin 4 ◽  
Molar Ratio ◽  
Homogeneous Surface ◽  
Anti Inflammatory

Pinelliae Rhizoma Praeparatum cum Alumine (PRPCA) is an important traditional processed herbal medicine mainly used for treating phlegm in China for more than 2000 years. In our previous studies, extraction optimization, characterization, and bioactivities of total polysaccharides from PRPCA were investigated. In this study, further purification of these polysaccharides was performed. Two polysaccharides named neutral fraction of total polysaccharides-II (TPN-II) and acidic fraction of total polysaccharides-II (TPA-II) were obtained by gradient ion-exchange chromatography followed by gel-permeation chromatography. Results of scanning electron microscopy (SEM) analysis in the present study showed that TPN-II had a tight structure with a rough and uneven surface, while TPA-II had a relative homogeneous surface and a loose structure. Further studies indicated that TPN-II was a homosaccharide mainly composed by glucose with a molecular weight of 8.0 kDa. TPA-II was mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose in a molar ratio of 2.1, 2.3, 1.7, 10.6, 2.6, 14.2, and 2.5, with a molecular weight of 1250 kDa. The nuclear magnetic resonance (NMR) results indicated that α and β form glycoside bonds existed in TPN-II and TPA-II, and TPN-II was composed of α-glucopyranose. In addition, both purified polysaccharides have significant anti-inflammatory effects on mucus secretion of human airway epithelial NCI-H292 cells without cytotoxicity. Compared with TPN-II, TPA-II exhibited more significant anti-inflammatory effects on lipopolysaccharide (LPS)-induced airway inflammation by regulating levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) and inhibiting mucus secretion. The results suggest that polysaccharides from PRPCA could be explored as therapeutic agents in treating inflammation and over secretion of mucus in asthma.

scholarly journals Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1114 ◽  
Author(s):  
Yani Luo ◽  
Jian Li ◽  
Derong Luo ◽  
Qingliang You ◽  
Zifeng Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Gel Permeation Chromatography ◽  
13C Nmr Spectroscopy ◽  
Molar Ratio ◽  
Tandem Catalysis ◽  
Titanium Complexes ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Branching Degree

A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature 13C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 106 g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti2L1 with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

Multiple forms of ribonuclease II in mouse liver: relative sizes, subcellular distributions, and pH–activity profiles

1987 ◽  
Vol 65 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Scot R. Kimball ◽  
William L. Meyer
Keyword(s):  
Molecular Weight ◽  
Mouse Liver ◽  
Heavy Particle ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Total Activity ◽  
Exchange Chromatography ◽  
The Other ◽  
Multiple Forms ◽  
Small Series

Multiple forms of ribonuclease II (EC 3.1.27.5) have been resolved from extracts of crude fractions of mouse liver by ion-exchange chromatography on phosphocellulose and gel permeation chromatography. The forms are designated 6S, 6L, 5S, 5L, 4S, 4L, 3S, 3L, 2, and 1 in increasing order of apparent cationic character. The forms fall into two series of apparent molecular weight. The small series increases from molecular weight equal to 9000 for form 1 to 14 000 for form 6S. The large series increases from molecular weight equal to 22 000 for form 2 to 44 000 for form 6L. All forms have pH–activity profiles with maxima near pH 7. Activity falls to no less than 30% of this maximum at pHs 5 and 8.5. Relative to the other forms, form 1 has a higher ratio of activity in the alkaline compared with acid pH range. Form 1 is found in the cytosolic, "light" particle, and "heavy" particle fractions. The other forms are largely restricted to the heavy particle fraction. In this fraction the proportion of total activity attributable to each form generally decreases in order from form 1 down to form 6. The results are accommodated by models in which one or more gene products give rise to multiple forms of ribonuclease II by processes involving dimerization and glycosylation.

Ethylene Polymerization by Thioether Bridged Dinuclear Titanocene Complex

2011 ◽  
Vol 213 ◽  
pp. 354-357 ◽  
Author(s):  
Yu Jing Nie ◽  
Ming Yang
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Ethylene Polymerization ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
High Concentration ◽  
Highly Active ◽  
Cyclopentadienyl Ligand ◽  
Broad Molecular Weight Distribution

The thioether bridged metallocene complex [(C5H5)Cl2TiC5H4CH2CH2]2S has been synthesized by treating the dilithium salts of the thioether bridged cyclopentadienyl ligand with two equivalents of C5H5TiCl3 and characterized by 1HMNR and elemental analysis. After activation with methylaluminoxane (MAO), the complex was highly active catalysts for homogeneous ethylene polymerization in toluene. The influence of the molar ratio [MAO]/[Cat], the catalyst concentration, time and temperature have been studied systematically. The catalytic activity of 1 is 3.63×105 g PE/mol•Cat•h. Rising the polymerization temperature decreases the catalytic activity for 1. A high concentration of the catalysts drops the catalytic activity as well as the molecular weight of polyethylene for the complex. High temperature gel permeation chromatography (HT-GPC) proves the production of polyethylene with a broad molecular weight distribution (MWD).

A convenient route to distannanes, oligostannanes, and polystannanes

2010 ◽  
Vol 88 (10) ◽  
pp. 1046-1052 ◽  
Author(s):  
Aman Khan ◽  
Robert A. Gossage ◽  
Daniel A. Foucher
Keyword(s):  
Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Low Pressure ◽  
Inert Atmosphere ◽  
Major Product ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Gel Permeation ◽  
Highly Dispersed ◽  
Convenient Route

The quantitative conversion of the tertiary stannane (n-Bu)3SnH (2) into (n-Bu)6Sn2 (4) was achieved by heating the neat hydride material under low pressure or under closed inert atmosphere conditions. A 31% conversion of Ph3SnH (3) to Ph6Sn2 (5) was also observed under low pressure; however, under closed inert atmosphere conditions afforded Ph4Sn (6) as the major product. A mixed distannane, (n-Bu)3SnSnPh3 (7), can also be prepared in good yield utilizing an equal molar ratio of 2 and 3 and the same reaction conditions used to prepare 4. This solvent-free, catalyst-free route to distannanes was extended to a secondary stannane, (n-Bu)2SnH2 (8), which yielded evidence (NMR) for hydride terminated distannane H(n-Bu)2SnSn(n-Bu)2H (9), the polystannane [(n-Bu)2Sn]n (10), and various cyclic stannanes [(n-Bu)2Sn]n=5,6 (11, 12). Further evidence for 10 was afforded by gel permeation chromatography (GPC) where a broad, moderate molecular weight, but highly dispersed polymer, was obtained (Mw = 1.8 × 104 Da, polydispersity index (PDI) = 6.9) and a characteristic UV–vis absorbance (λmax) of ≈370 nm observed.

scholarly journals A Polysaccharide Produced by Lactococcus lactis subsp. lactis YZ1 Isolated from Traditional Indonesian Fermented Milk, "Dadih"

2000 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Yusdar Zakaria
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Lactococcus Lactis ◽  
Monosaccharide Composition ◽  
Fermented Milk ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Neutral Sugar ◽  
Glycoside Linkage

ABSTRACT.Lactococcus lactis subsp. Lactis YZI was isolated from M17 agar in which diluted Dadih was poured and incubated at 30 0C for 48 h. Taxonomix properties of the isolate were examined according to Bergey’s Manual of Systematic Bacteriologi and Manual for  Identification of Medical Bacteria. The isolation of polysaccharide from the precipitant was performed on an ion-exchange chromatography. The result showed that the polysaccharides produced by Lactococus lactis subsp. lactis YZI were neutral sugar (unadsorbrd fraction) and glycoconjugated (absorbed fraction). The neutral sugar had molecular weight of 10,000 and 20,000 with and α-glycoside linkage. The monosaccharide composition was mannose, glucose and galactose with a molar ratio of 1 :1,5 : 4,9.

scholarly journals Cytokine profile of cervical mucus at different forms of papillomavirus infection

2014 ◽  
Vol 95 (5) ◽  
pp. 642-645
Author(s):  
O V Skidanenko-Levina
Keyword(s):  
Inflammatory Cytokines ◽  
Interleukin 2 ◽  
Interleukin 10 ◽  
Interferon Γ ◽  
Epithelial Dysplasia ◽  
Interleukin 4 ◽  
Necrosis Factor Alpha ◽  
Papillomavirus Infection ◽  
Anti Inflammatory ◽  
Cervical Secretion

Aim. To study the levels of pro- and anti-inflammatory cytokines in cervical secretion in females with cervical epithelial dysplasia and latent papillomavirus infection. Methods. The study included 120 females aged 20 to 40 years with cervical papillomavirus infection, who were assigned to two groups using «case-control» method. The first group included 60 females with latent disease, the second group - 60 females with mild and moderate cervical epithelial dysplasia (cervical intraepithelial neoplasia stages I and II). Cytokine levels in cervical secretion were measured by ELISA using «ProCon» test system. Results. ELISA test showed increased levels of interleukin-4 and interleukin-10 (43 [21; 74] and 48 [12; 88] pg/ml, respectively) and decreased levels of interleukin-2 (18.5 [5.5; 27.5] pg/ml), interleukin-6 (0.6 [0.06; 0.9] pg/ml), tumor necrosis factor alpha (88.5 [0; 123] pg/ml), interferon γ (2 [0; 4] pg/ml) in cervical secretion of females with cervical epithelial dysplasia compared to females with latent papillomavirus infection. Thus, females with cervical epithelial dysplasia showed increased levels of anti-inflammatory cytokines: interleukin-4 - by 2.7 times and interleukin-10 - by 2.4 times compared to females with latent disease, while levels of pro-inflammatory cytokines was decreased as following: interleukin-2 - by 1.4 times, interleukin-6 - by 4.5 times, tumor necrosis factor alpha - by 1.8 times, interferon γ - by 6.3 times (p 0.05). Conclusion. Imbalance of immune response cytokine regulation with anti-inflammatory cytokines prevailing might be an important factor facilitating persistence of papillomavirus in cervical epithelium and contributing to cervical epithelial dysplasia onset and progression.

scholarly journals Homologous Over-Expression of Chain Length Determination Protein EpsC Increases the Molecular Weight of Exopolysaccharide in Streptococcus thermophilus 05-34

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhengyuan Zhai ◽  
Shuxin Xie ◽  
Hongxing Zhang ◽  
Huaxi Yi ◽  
Yanling Hao
Keyword(s):  
Molecular Weight ◽  
Chain Length ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Streptococcus Thermophilus ◽  
Monosaccharide Composition ◽  
Molar Ratio ◽  
Gas Chromatography Mass Spectrometry ◽  
Over Expression ◽  
Length Determination

In Streptococcus thermophilus, EpsC is a polysaccharide co-polymerase which is involved in determining the chain length of EPS synthesized by the Wzx/Wzy-dependent pathway. Our previous study found that there was a positive correlation between transcription level of epsC and molecular weight of EPS in S. thermophilus 05-34. To further investigate the effects of EpsC on EPS biosynthesis, this gene was over-expressed in S. thermophilus 05-34 in this study. Reverse transcription qPCR and Western blotting confirmed the successful transcription and translation of epsC in 05-34, respectively. The yield of EPS was not affected by the over-expression of EpsC. Gas chromatography-mass spectrometry (GC-MS) showed that the monosaccharide composition was still composed of galactose and glucose in a molar ratio of 1.0:0.8, whereas high performance gel permeation chromatography (HPGPC) indicated that the molecular weight of EPS was increased from 4.62 × 105 Da to 9.17 × 105 Da by the over-expression of EpsC. In addition, S. thermophilus 05epsC which could produce higher molecular weight EPS improved the viscoelasticity and water-holding capacity of yogurt, but significantly reduced the level of syneresis in yogurt. In summary, these results indicated that homologous over-expression of EpsC in S. thermophilus could increase the molecular weight of EPS and improve the microrheological or physical properties of yogurt.

Binary molybdenum-based catalyst for coordination polymerization of styrene

2016 ◽  
Vol 49 (5) ◽  
pp. 408-421 ◽  
Author(s):  
Jieting Geng ◽  
Youguo Shao ◽  
Feng Song ◽  
Feng Li ◽  
Jing Hua
Keyword(s):  
Molecular Weight ◽  
Catalyst Activity ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Bulk Polymerization ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Coordination Polymerization ◽  
Co Catalyst

Coordination polymerization of styrene (St) using molybdenum pentachloride supported by phosphite ligand in the presence of metal organic compound was studied for the first time. The types of phosphite and co-catalysts significantly affected the catalytic activity of the molybdenum (V) (Mo(V)) active center and the number-average molecular weight ( Mn) of the resultant polymer. Among the examined catalysts, tri(nonylphenyl)phosphite (TNPP) ligand and AlOPhCH3( i-Bu)2 as co-catalyst provided the polymer with highest yield (up to 87.1%), metallocene as co-catalyst provided the polymer with highest Mn (up to 5.32 × 105). The effect of [P]/[Mo] molar ratio on catalyst activity of the polymerization was discussed and the structures of Mo·TNPP complexes were preliminarily studied by infrared (IR) and ultraviolet spectroscopies. Besides, the polystyrene (PS) samples synthesized through bulk polymerization and solution polymerization were characterized by gel permeation chromatography, IR, carbon 13 nuclear magnetic resonance, and differential scanning calorimetry, respectively, and the results indicated both of the PS had high molecular weight (approximately 105) and atactic structure. All these results demonstrated that Mo(V) catalyst system was very effective for St polymerization.

Study on Synthesis and Properties of Phenols Polymer Syntan Catalyzed by Enzyme

2011 ◽  
Vol 138-139 ◽  
pp. 1072-1077
Author(s):  
Sheng Hua Lv ◽  
Rui Gong ◽  
Yan Fen Ma
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Structure And Properties ◽  
Monomer Composition ◽  
Gel Permeation

A phenolic copolymer was synthesized from resorcinol (RSC) and 3,5-dihydroxy benzoic acid (DBA) using horseradish peroxidase (HRP)/H2O2 as the radical copolymerization’s initiateor. It was discussed that the effects of monomer composition on the properties of the copolymer. The best molar ratio was 1:1. The structure and properties of the copolymer was characterized by Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (HNMR), Molecular weight (MW) was determined by gel permeation chromatography (GPC). The result shows that the average molecular weight of the copolymer is about 40000. The effect of dosage of HRP on the properties of the copolymer was investigated. And the mechanism of polymerization of RSC and DBA was advanced. The copolymer was used as tanning agent, applied results show that it has excellent retanning properties. It was realized the applicatiom of HRP on the phenols syntan.

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