scholarly journals Extract Methods, Molecular Characteristics, and Bioactivities of Polysaccharide from Alfalfa (Medicago sativa L.)

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1181 ◽  
Author(s):  
Chen Zhang ◽  
Zemin Li ◽  
Chong-Yu Zhang ◽  
Mengmeng Li ◽  
Yunkyoung Lee ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Medicago Sativa ◽  
Biological Activities ◽  
Average Molecular Weight ◽  
Molar Ratio ◽  
Molecular Characteristics ◽  
Ionization Mass ◽  
Potential Candidate ◽  
Dependent Manner ◽  
Medicago Sativa L

The polysaccharide isolated from alfalfa was considered to be a kind of macromolecule with some biological activities; however, its molecular structure and effects on immune cells are still unclear. The objectives of this study were to explore the extraction and purifying methods of alfalfa (Medicago sativa L.) polysaccharide (APS) and decipher its composition and molecular characteristics, as well as its activation to lymphocytes. The crude polysaccharides isolated from alfalfa by water extraction and alcohol precipitation methods were purified by semipermeable membrane dialysis. Five batches of alfalfa samples were obtained from five farms (one composite sample per farm) and three replicates were conducted for each sample in determination. The results from ion chromatography (IC) analysis showed that the APS was composed of fucose, arabinose, galactose, glucose, xylose, mannose, galactose, galacturonic acid (GalA), and glucuronic acid (GlcA) with a molar ratio of 2.6:8.0:4.7:21.3:3.2:1.0:74.2:14.9. The weight-average molecular weight (Mw), number-average molecular weight (Mn), and Z-average molecular weight (Mz) of APS were calculated to be 3.30 × 106, 4.06 × 105, and 1.43 × 108 g/mol, respectively, according to the analysis by gel permeation chromatography-refractive index-multiangle laser light scattering (GPC-RI-MALS). The findings of electron ionization mass spectrometry (EI-MS) suggest that APS consists of seven linkage residues, namely 1,5-Araf, galactose (T-D-Glc), glucose (T-D-Gal), 1,4-Gal-Ac, 1,4-Glc, 1,6-Gal, and 1,3,4-GalA, with molar proportions of 10.30%, 4.02%, 10.28%, 52.29%, 17.02%, 3.52%, and 2.57%, respectively. Additionally, APS markedly increased B-cell proliferation and IgM secretion in a dose- and time-dependent manner but not the proliferation and cytokine (IL-2, -4, and IFN-γ) expression of T cells. Taken together, the present results suggest that APS are macromolecular polymers with a molar mass (indicated by Mw) of 3.3 × 106 g/mol and may be a potential candidate as an immunopotentiating pharmaceutical agent or functional food.

Metathesis Polymerization of Phenylacetylene by Tungsten Aryloxo Complexes

1995 ◽  
Vol 60 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Hynek Balcar ◽  
Jan Sedláček ◽  
Marta Pacovská ◽  
Vratislav Blechta
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Induction Period ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Molar Ratio ◽  
Weight Average Molecular Weight ◽  
Polymer Yield ◽  
Positive Effect ◽  
Ligand Addition

Catalytic activity of the tungsten aryloxo complexes WCl5(OAr) and WOCl3(OAr), where Ar = 4-t-C4H9C6H4, 2,6-(t-C4H9)2C6H3, 2,6-Cl2C6H3, 2,4,6-Cl3C6H2, and 2,4,6-Br3C6H2 in polymerization of phenylacetylene (20 °C, monomer to catalyst molar ratio = 1 000) was studied. The activity of WCl5(OAr) as unicomponent catalysts increases with increasing electron withdrawing character of the -OAr ligand. Addition of two equivalents of organotin cocatalysts (Me4Sn, Bu4Sn, Ph4Sn, Bu3SnH) to WCl5(O-C6H2Cl3-2,4 ,6) has only slight positive effect (slightly higher polymer yield and/or molecular weight of poly(phenylacetylene)s was achieved). However, in the case of WOCl3(O-C6H3Cl2-2, 6) catalyst, it enhances the activity considerably by eliminating the induction period. Poly(phenylacetylene)s prepared with the catalysts studied have weight-average molecular weight ranging from 100 000 to 200 000. They are trans-prevailing and have relatively low molar fraction of monomer units comprised in cyclohexadiene sequences (about 6%).

Biological activity of partially purified low molecular weight luteinizing hormone binding inhibitor in porcine follicular fluids

1993 ◽  
Vol 128 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Nobuyoshi Kokawa ◽  
Mareo Yamoto ◽  
Kenichi Furukawa ◽  
Ryosuke Nakano
Keyword(s):  
Molecular Weight ◽  
Luteinizing Hormone ◽  
Competitive Inhibition ◽  
Biological Activities ◽  
Partial Purification ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Hormone Binding ◽  
Dose Dependent ◽  
Follicular Fluids

We performed partial purification of low molecular weight luteinizing hormone binding inhibitor from porcine follicular fluids and examined its biological activities. Following ultrafiltration, gel filtration and anion exchange of the pooled porcine follicular fluids, low molecular weight fractions (500–10,000 MW) inhibited [125I]hLH binding to porcine granulosa cells in a dose-dependent manner. The binding inhibition kinetics study revealed that the luteinizing hormone binding inhibitor may indicate a non-competitive inhibition with [125I]hLH binding. In vitro bioassay using adult mouse testicular interstitial cells revealed that the partially purified luteinizing hormone binding inhibitor reduced ovine LH-stimulated testosterone and cAMP production in a dose-dependent manner, whereas the luteinizing hormone binding inhibitor did not affect basal production of testosterone and cAMP. The inhibitory activity was heat stable and did not disappear with activated charcoal adsorption. The results of the present study suggest that the luteinizing hormone binding inhibitor may play an important role as an ovarian non-steroidal regulator modulating the receptor binding of LH and LH-mediated steroidogenesis.

scholarly journals A straightforward electrospray ionization high resolution mass spectrometry method for underivatized long chain polysaccharides

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Roxana M. Ghiulai ◽  
Mirela Sarbu ◽  
Constantin Ilie ◽  
Alina D. Zamfir
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Electrospray Ionization ◽  
High Resolution Mass Spectrometry ◽  
Average Molecular Weight ◽  
Ionization Mass ◽  
Esi Ms ◽  
Singly Charged ◽  
Charged Ions ◽  
Long Chain

AbstractStructural analysis of long chain polysaccharides by electrospray ionization mass spectrometry (ESI-MS) is challenging since these molecules do not contain readily ionizable groups. Their mass spectra are dominated by singly charged ions, limiting the detection of high molecular weight species. Derivatization can enhance ionization, but analyte loss on purification decreases sensitivity. We report a method based on nanoESI-MS and MS/MS by collision induced dissociation (CID) for underivatized long chain polysaccharides. The procedure was tested on underivatized polydisperse dextrans (average molecular weight 4,000) at 2.6 kV ESI voltage and CID MS/MS at energies between 30-60 eV. 113 ions corresponding to species from Glc2 to Glc35 were detected. Ions at m/z 1,409.48, 1,107.35 and 1,438.47, assigned to [G17+2Na]2+,[G20+H+Na+K]3+ and [G35+2H+Na+K]4+, were sequenced and characterized by MS/MS. The component containing 35 Glc repeats is the longest polysaccharide chain detected by ESI-MS and structurally analyzed by MS/MS without prior derivatization and/or separation.

scholarly journals The apoptotic effect of polysaccharides with specific molecular weight extracted from Inonotus obliquus on HT-29 colon cancer cells

2020 ◽  
Author(s):  
Xue Han ◽  
Sainan Zhao ◽  
Yu Wang ◽  
Jialei Sun ◽  
Shiwei Chen
Keyword(s):  
Molecular Weight ◽  
Cancer Cells ◽  
Morphological Changes ◽  
Underlying Mechanism ◽  
Potential Candidate ◽  
Dependent Manner ◽  
Nuclear Condensation ◽  
Inonotus Obliquus ◽  
Apoptotic Effect ◽  
Ht 29

Abstract Background: Recently, natural products, particularly Inonotus obliquus (I. obliquus), have attracted lots of attention due to their effective anticancer effects with relatively low toxicity. Results: I. obliquus polysaccharides (IOP) with different molecular weights were obtained by filtering the aqueous extract through fractional membrane. IOP60b (10 kDa ≤ molecular weight ≤ 30 kDa) with the highest yield and inhibition ratio of HT-29 cancer cells was chosen to evaluate the apoptotic effect on HT-29 cancer cells. After treated with different concentrations of IOP60b, morphological changes including cell shrinkage and nuclear condensation and DNA fragmentation of HT-29 cancer cells were observed. In addition, the proportions of cells in early apoptosis and late apoptosis were significantly (p<0.05) increased in a dose-dependent manner. To further explore the underlying mechanism, RT-PCR and Western blotting were employed. Results indicated that both Bcl-2 family and Caspase family were involved in the regulation process of apoptosis and IOP60b induced cellular apoptosis via upregulation of Bax/Bcl-2 ratio and activation of Caspase-3.Conclusion: These data suggested that IOP60b could be a potential candidate for the clinical prevention and treatment of colorectal cancer.

Synthesis and Properties of Biodegradable ABA Triblock Copolymers of Polylactide (A) and Polyethylene Glycol (B)

2006 ◽  
Vol 11-12 ◽  
pp. 469-472 ◽  
Author(s):  
Shu Xian Shi ◽  
Yu Zheng Xia ◽  
Xiao Yan Ma ◽  
Shu Ke Jiao ◽  
Xiao Yu Li
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Analytical Techniques ◽  
Normal Pressure ◽  
Molar Ratio ◽  
Poly Ethylene Glycol ◽  
Molar Ratios ◽  
Poly Ethylene

The triblock ABA copolymers of poly (D,L-lactide)-b-poly (ethylene glycol)-b-poly (D,L-lactide) (PDLLA-PEG-PDLLA) were synthesized by bulk ring-opening polymerization in the presence of N2 under normal pressure, using the D,L-lactide (DLLA) as monomer, hydroxyl endgroups of poly(ethylene glycol) (PEG) as initiator and the stannous octoate as the catalyst. The resulting copolymers were characterized by various analytical techniques. Effects of molar ratios of lactide to PEG and the chain length of PEG on the viscosity-average molecular weight of the copolymers, the biodegradation behaviors and hydrophilicity of the copolymers were investigated in detail. The results showed that the viscosity-average molecular weight and the contact angle of the copolymers increased with the molar ratio of lactide to PEG, but water uptake and degradability decreased.

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.

scholarly journals The Antioxidant Effect of Medicago sativa L. (Alfalfa) Ethanolic Extract against Mercury Chloride (HgCl2) Toxicity in Rat Liver and Kidney: An In Vitro and In Vivo Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
M. Raeeszadeh ◽  
M. Moradi ◽  
P. Ayar ◽  
Abolfazl Akbari
Keyword(s):  
Body Weight ◽  
Medicago Sativa ◽  
Ethanolic Extract ◽  
The Body ◽  
Control Group ◽  
Mercury Chloride ◽  
Dependent Manner ◽  
Histopathological Evaluation ◽  
Medicago Sativa L ◽  
Different Doses

Heavy metals such as mercury are some of the environmental pollutants and can induce toxicity by bioaccumulation and oxidative damage. This study aimed to investigate the effect of ethanolic extract of Medicago sativa L. (Alfalfa) on mercury damage in the kidney and liver of rats. Thirty Wistar rats were randomly divided into five groups, the control group, S group (2 mg/kg mercury chloride), and T1, T2, and T3 groups that, in addition to mercury, received doses of 250, 500, and 750 mg/kg of the alfalfa extract. On the last day, blood samples were taken, and the serum was separated to measure biochemical and oxidative stress parameters in the kidney and liver. A part of the kidney and liver was also used for histopathological evaluation. Total phenols and flavonoids were 40.45 ± 2.12 and 14.36 ± 0.45 mg/g, respectively, whereas IC50 was 245.18 ± 19.76 μg/ml. The body weight significantly decreased in the S group compared to other groups, while treatment with different doses of alfalfa extract increased the body weight. Mercury concentration in the kidney was higher than that in the liver. The serum levels of urea, creatinine, alanine aminotransferase (ALT), and alkaline phosphatase (ALP) significantly increased in the S group compared to the control group, while treatment with different doses of alfalfa extract increased their levels. Moreover, an increase in malondialdehyde (MDA) and a decrease in glutathione peroxidase (GPx), catalase (CAT), total antioxidant capacity (TAC), and superoxide dismutase (SOD) activity were observed in the S group. The level of these parameters significantly improved in the groups receiving the extract compared to the S group. Furthermore, the histopathological evaluation showed glomerular and tubular damage and hepatic necrosis in the S group and that these conditions improved in the T3 group. The findings of this study showed that the ethanolic extract of alfalfa in a dose-dependent manner has potentially unique protective effects against mercury poisoning in the kidney and liver.

scholarly journals The Apoptotic Effect of Polysaccharides with Specific Molecular Weight Extracted from Inonotus Obliquus on HT-29 Colon Cancer Cells

2020 ◽  
Author(s):  
Xue Han ◽  
Sainan Zhao ◽  
Yu Wang ◽  
Jialei Sun ◽  
Shiwei Chen
Keyword(s):  
Molecular Weight ◽  
Cancer Cells ◽  
Membrane Filtration ◽  
Water Extract ◽  
Potential Candidate ◽  
Dependent Manner ◽  
Inonotus Obliquus ◽  
Filtration Method ◽  
Apoptotic Effect ◽  
Ht 29

Abstract Background: Recently, much attention has been paid to natural products owing to their effective anticancer effects with relatively low toxicity, especially Inonotus obliquus (I. obliquus).Results: Polysaccharides with different molecular weights were filtered from water extract of I. obliquus using grading membrane filtration method. IOP60b (10 kDa ≤ molecular weight ≤ 30 kDa) was found to have the highest yield and the highest inhibition ratio of HT-29 cancer cells, therefore it was chosen to evaluate the apoptotic effect of HT-29 cancer cells. After treated with different concentrations of IOP60b, morphological changes including cell shrinkage and nuclear condensation and DNA fragmentation in HT-29 cancer cells were observed, and cells in early apoptosis and late apoptosis significantly (p<0.05) increased in a dose-dependent manner by arresting cell cycle at G0/G1 phase. To further explore the underlying mechanism, RT-PCR and Western blotting were applied. Results indicated that both Bcl-2 family and Caspase family were involved in the process of apoptosis regulation and IOP60b induced cellular apoptosis via upregulation of Bax/Bcl-2 ratio and activation of Caspase-3.Conclusion: These data suggested that IOP60b might be the potential candidate for the clinical prevention and treatment of colorectal cancer.

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