scholarly journals Characterization and Antioxidant Activity of a Low-Molecular-Weight Xanthan Gum

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 730 ◽  
Author(s):  
Hu ◽  
Wang ◽  
Yu ◽  
He ◽  
Qiao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyl Radicals ◽  
Xanthan Gum ◽  
Glucuronic Acid ◽  
Reducing Power ◽  
Monosaccharide Composition ◽  
Molar Ratio ◽  
Low Molecular Weight ◽  
Oxygen Species ◽  
Superoxide Anions

In the present work, a low-molecular-weight xanthan gum (LW-XG) was successfully obtained via biodegradation of commercial xanthan by the endophytic fungus Chaetomium globosum CGMCC 6882. The monosaccharide composition of LW-XG was glucose, mannose, and glucuronic acid in a molar ratio of 1.63:1.5:1.0. The molecular weight of LW-XG was 4.07 × 104 Da and much smaller than that of commercial xanthan (2.95 × 106 Da). Antioxidant assays showed that LW-XG had a good scavenging ability on DPPH radicals, superoxide anions, and hydroxyl radicals and good ferric reducing power. Moreover, LW-XG exhibited excellent protective effect on H2O2-injured Caco-2 cells. Results of this work suggested that LW-XG could be used in foods or pharmaceuticals to alleviate and resist the oxidative damage induced by the overproduction of reactive oxygen species.

scholarly journals Low-Molecular-Weight Polyethyleneimine Grafted Polythiophene for Efficient siRNA Delivery

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pan He ◽  
Kyoji Hagiwara ◽  
Hui Chong ◽  
Hsiao-hua Yu ◽  
Yoshihiro Ito
Keyword(s):  
Molecular Weight ◽  
Sirna Delivery ◽  
Fluorescent Microscopy ◽  
Molar Ratio ◽  
Low Molecular Weight ◽  
Label Free ◽  
Endosomal Membrane ◽  
Cationic Copolymers ◽  
Interfering Rna

Owing to its hydrophilicity, negative charge, small size, and labile degradation by endogenous nucleases, small interfering RNA (siRNA) delivery must be achieved by a carrier system. In this study, cationic copolymers composed of low-molecular-weight polyethylenimine and polythiophenes were synthesized and evaluated as novel self-tracking siRNA delivery vectors. The concept underlying the design of these copolymers is that hydrophobicity and rigidity of polythiophenes should enhance the transport of siRNA across the cell membrane and endosomal membrane. A gel retardation assay showed that the nanosized complexes formed between the copolymers and siRNA were stable even at a molar ratio of 1 : 2. The high cellular uptake (>80%) and localization of the copolymer vectors inside the cells were easily analyzed by tracking the fluorescence of polythiophene using fluorescent microscopy and cytometry. Anin vitroluciferase knockdown (KD) assay in A549-luc cells demonstrated that the siRNA complexes with more hydrophobic copolymers achieved a higher KD efficiency of 52.8% without notable cytotoxicity, indicating protein-specific KD activity rather than solely the cytotoxicity of the materials. Our polythiophene copolymers should serve as novel, efficient, low cell toxicity, and label-free siRNA delivery systems.

scholarly journals Polythiophenes with Cationic Phosphonium Groups as Vectors for Imaging, siRNA Delivery, and Photodynamic Therapy

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1432
Author(s):  
Laure Lichon ◽  
Clément Kotras ◽  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Morgane Daurat ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Photophysical Properties ◽  
Combined Therapy ◽  
Sirna Delivery ◽  
Aqueous Media ◽  
Low Molecular Weight ◽  
Oxygen Species ◽  
Cationic Polymers ◽  
Intracellular Location

In this work, we exploit the versatile function of cationic phosphonium-conjugated polythiophenes to develop multifunctional platforms for imaging and combined therapy (siRNA delivery and photodynamic therapy). The photophysical properties (absorption, emission and light-induced generation of singlet oxygen) of these cationic polythiophenes were found to be sensitive to molecular weight. Upon light irradiation, low molecular weight cationic polythiophenes were able to light-sensitize surrounding oxygen into reactive oxygen species (ROS) while the highest were not due to its aggregation in aqueous media. These polymers are also fluorescent, allowing one to visualize their intracellular location through confocal microscopy. The most promising polymers were then used as vectors for siRNA delivery. Due to their cationic and amphipathic features, these polymers were found to effectively self-assemble with siRNA targeting the luciferase gene and deliver it in MDA-MB-231 cancer cells expressing luciferase, leading to 30–50% of the gene-silencing effect. In parallel, the photodynamic therapy (PDT) activity of these cationic polymers was restored after siRNA delivery, demonstrating their potential for combined PDT and gene therapy.

scholarly journals Role of mitochondrial superoxide dismutase in contraction-induced generation of reactive oxygen species in skeletal muscle extracellular space

2004 ◽  
Vol 286 (5) ◽  
pp. C1152-C1158 ◽  
Author(s):  
A. McArdle ◽  
J. van der Meulen ◽  
G. L. Close ◽  
D. Pattwell ◽  
H. Van Remmen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Extracellular Space ◽  
Superoxide Anion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Superoxide Anions ◽  
Wild Type ◽  
Mnsod Activity

Contractions of skeletal muscles produce increases in concentrations of superoxide anions and activity of hydroxyl radicals in the extracellular space. The sources of these reactive oxygen species are not clear. We tested the hypothesis that, after a demanding isometric contraction protocol, the major source of superoxide and hydroxyl radical activity in the extracellular space of muscles is mitochondrial generation of superoxide anions and that, with a reduction in MnSOD activity, concentration of superoxide anions in the extracellular space is unchanged but concentration of hydroxyl radicals is decreased. For gastrocnemius muscles from adult (6–8 mo old) wild-type ( Sod2+/+) mice and knockout mice heterozygous for the MnSOD gene ( Sod2+/-), concentrations of superoxide anions and hydroxyl radical activity were measured in the extracellular space by microdialysis. A 15-min protocol of 180 isometric contractions induced a rapid, equivalent increase in reduction of cytochrome c as an index of superoxide anion concentrations in the extracellular space of Sod2+/+ and Sod2+/- mice, whereas hydroxyl radical activity measured by formation of 2,3-dihydroxybenzoate from salicylate increased only in the extracellular space of muscles of Sod2+/+ mice. The lack of a difference in increase in superoxide anion concentration in the extracellular space of Sod2+/+ and Sod2+/- mice after the contraction protocol supported the hypothesis that superoxide anions were not directly derived from mitochondria. In contrast, the data obtained suggest that the increase in hydroxyl radical concentration in the extracellular space of muscles from wild-type mice after the contraction protocol most likely results from degradation of hydrogen peroxide generated by MnSOD activity.

Seasonal changes in the chemical composision of the red alga Hypnea musciformis

1973 ◽  
Vol 24 (3) ◽  
pp. 275
Author(s):  
AF Abdel ◽  
NM Abed ◽  
M Edrees
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Seasonal Changes ◽  
Free Amino ◽  
Glucuronic Acid ◽  
Red Alga ◽  
Low Molecular Weight ◽  
Hypnea Musciformis ◽  
Algal Material

Seasonal changes were observed in the chemical composition of the marine red alga Hypnea musciformis. Lipids, cholesterol, and lanosterol were found as constituents of the algal material. No low-molecular weight carbohydrates were found except small amounts of mannitol. The algal hydrolysate was shown to contain galactose, glucose, and xylose in all seasons and was characterized by a high content of glucuronic acid and its lactone in February. Definite seasonal variations were found in the patterns of free amino acids and of amino acid compositions of proteins.

scholarly journals Purification and Characterization of a New Lectin from Loach Skin Mucus

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Peng-peng Sun ◽  
Yuan-yuan Ren ◽  
Jie Zheng ◽  
Ai-jun Hu
Keyword(s):  
Molecular Weight ◽  
Carbohydrate Chain ◽  
Acid Resistance ◽  
Monosaccharide Composition ◽  
Molar Ratio ◽  
Pathogen Defense ◽  
Hemagglutination Activity ◽  
Purification And Characterization ◽  
Skin Mucus

Lectin from loach skin mucus plays an important role in pathogen defense. However, hardly can any paper relevant to the character of lectin from loach skin mucus be found in recent years. In this study, a kind of new lectin (LML), with a high hemagglutination activity of 166.23 × 103 HU/mg, was successfully isolated and purified from loach skin mucus. LML was a kind of glycoprotein with a molecular weight of 245 kDa. Also, the monosaccharide composition suggested that its carbohydrate chain was composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose with a molar ratio of 2.02 : 11.66 : 2.06 : 1.00 : 14.09 : 6.00. Besides, LML depended on Ca2+ to induce hemagglutination and was strongly inhibited by D-lactose. The lectin exhibited powerful resistance to alkali and kept about 30% hemagglutination activity at pH 14.0, whereas its capacity of acid resistance was weak. The maximum hemagglutination activity of LML maintained at a temperature range from 20°C to 50°C. Moreover, the structure of LML was preliminarily studied, indicating it contained abundant glutamic acid, histidine, and serine, and its secondary structure contained α-helix (4.97%), β-sheet (27.55%), turns structure (49.78%), and unordered structure (17.70%).

Biodiesel fuel synthesis by interesterification of triglycerides with carboxylate esters of low molecular weight

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Egle Sendzikiene ◽  
Violeta Makareviciene
Keyword(s):  
Molecular Weight ◽  
Raw Materials ◽  
Fatty Acid Esters ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Transport Sector ◽  
Biodiesel Fuel ◽  
Low Molecular Weight ◽  
Raw Glycerol ◽  
Biodiesel Synthesis

Abstract The ever-increasing environmental pollution from greenhouse gases motivates the search for methods to reduce it. One such method is the use of biodiesel fuels in the transport sector. Conventional biodiesel production generates up to 10% of a by-product, raw glycerol, whose amount continues to increase as biodiesel production volumes expand, but its demand remains limited. Recently, options have been analysed to replace the triglyceride transesterification process generally used in biodiesel production with an interesterification process that does not generate raw glycerol, instead yielding triacylglycerol that can be directly used as fuel for diesel engines by mixing with fatty acid esters. Additionally, triacylglycerol improves the low-temperature properties of fuel. The present article discusses triglyceride interesterification processes using various carboxylate esters of low molecular weight. Information is provided on raw materials that can be subjected to interesterification for biodiesel synthesis. The possible applications of chemical and enzymatic catalysis for triglyceride interesterification are discussed, and the influence of the catalyst amount, molar ratio of reactants, temperature and process duration on the effectiveness of interesterification is examined. The conditions and effectiveness of noncatalytic interesterification are also discussed in the article. Qualitative indicators of the products obtained and their conformity to the requirements of the European standard for biodiesel fuel are discussed.

A reactive oxygen species (ROS)-responsive low molecular weight gel co-loaded with doxorubicin and Zn(ii) phthalocyanine tetrasulfonic acid for combined chemo-photodynamic therapy

2017 ◽  
Vol 5 (46) ◽  
pp. 9157-9164 ◽  
Author(s):  
Long Xu ◽  
Mingying Zhao ◽  
Yidi Yang ◽  
Yan Liang ◽  
Changzhen Sun ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Anticancer Drug ◽  
Reactive Oxygen ◽  
Low Molecular Weight ◽  
Oxygen Species

A ROS-responsive low molecular weight hydrogel was fabricated and loaded with an anticancer drug and a photosensitizer for efficient chemo-photodynamic therapy.

Production and Rheological Properties of Welan Gum Produced by Sphingomonas sp. ATCC 31555 with Different Nitrogen Sources

2017 ◽  
Vol 27 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Xiaopeng Xu ◽  
Zuoming Nie ◽  
Zhiyong Zheng ◽  
Li Zhu ◽  
Xiaobei Zhan
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Biomass Concentration ◽  
Bacterial Biomass ◽  
Nitrogen Sources ◽  
Monosaccharide Composition ◽  
Solution Concentration ◽  
Molar Ratio ◽  
Welan Gum ◽  
Beef Extract

This study aimed to investigate the effect of nitrogen sources on the production and rheological properties of welan gum produced by <i>Sphingomonas</i> sp. ATCC 31555. Six different nitrogen sources were used for ATCC 31555 fermentation, and 2 of these were further analyzed due to their more positive influence on welan gum production and bacterial biomass. Bacterial biomass, welan gum yield, welan viscosity, molecular weight, monosaccharide composition, acyl content, and welan structure were analyzed. Welan gum production and the biomass concentration of ATCC 31555 were higher in media containing NaNO<sub>3</sub> and beef extract. Welan viscosity decreased at higher temperatures of 30-90°C, and it increased with a higher welan concentration. In the media containing NaNO<sub>3</sub> (3 g·L<sup>-1</sup>), welan viscosity was higher at 30-70°C and a welan solution concentration of 6-10 g·L<sup>-1</sup>. With a reduced NaNO<sub>3</sub> concentration, the molecular weight of welan gum and the molar ratio of mannose decreased, but the molar ratio of glucuronic acid increased. With different nitrogen sources, the acetyl content of welan gum differed but its structure was similar. NaNO<sub>3</sub> and beef extract facilitated welan production. A reduced NaNO<sub>3</sub> concentration promoted welan viscosity.

scholarly journals Fructose 2,6-bisphosphate, the probably structure of the glucose- and glucagon-sensitive stimulator of phosphofructokinase

1980 ◽  
Vol 192 (3) ◽  
pp. 897-901 ◽  
Author(s):  
E Van Schaftingen ◽  
L Hue ◽  
H G Hers
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Reducing Power ◽  
Organic Phosphate ◽  
Low Molecular Weight ◽  
Acid Labile

The low-molecular-weight stimulator of phosphofructokinase [Van Schaftingen, Hue & Hers (1980) Biochem. J. 192, 887-895] has been purified from rat liver. It was completely destroyed upon incubation with 0.01 M-HCl for 10 min at 20 degrees C and fructose 6-phosphate and a reducing power equivalent in amount to the acid-labile organic phosphate were formed. It was therefore tentatively identified as fructose 2,6-bisphosphate.

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