Search results for "saccharide"

Ultraviolet B Irradiation Modulates the Immune System of Fish (Rutilus rutilus, Cyprinidae) Part III: Lymphocytes¶

2001

Abstract The effects of short-term exposure to ultraviolet B (UVB) radiation on lymphocyte-related parameters were studied under controlled laboratory conditions using roach (Rutilus rutilus), a cyprinid teleost, as the model fish. In vitro lymphoproliferative responses stimulated with a T-cell–specific mitogen, concanavalin A (ConA), or a B-cell–specific activator, lipopolysaccharide (LPS), were decreased in exposed fish. Also nonstimulated proliferation was lower than in unexposed fish. ConA-activated responses returned to normal levels within 7 days after exposure, but LPS-activated responses were reduced throughout the 14 day follow-up. The capability of UVB-exposed fish to produce an a…

Stereoselective synthesis of oligosaccharides by de novo saccharide welding

2012

Carbohydrates as Chemical Constituents of Biowaste Composts and their Humic and Fulvic Acids

1995

The decomposition of organic matter of source-separated biowaste during composting was followed during 18 months. Compost samples were fractionated into three parts: (i) hot water soluble extract (HWE) (ii) bitumen fraction and (iii) humic substances (humic acids (HA) and fulvic acids (FA)). Original compost samples and the HA and FA fractions were hydrolyzed with sulfuric acid for hexoses and pentoses. Quantitative spectrophotometric and qualitative GC/MS analyses of monosaccharides as trimethylsilyl ethers of the corresponding alditols were carried out.During composting, the amount of HA in the organic matter of the compost increased, the amounts of HWE and bitumen decreased and the amoun…

Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays.

2014

International audience; Increasing interest is devoted to carbohydrates for their roles in plant immunity. Some of them are elicitors of plant defenses whereas other ones act as signaling molecules in a manner similar to phytohormones. This review first describes the main classes of carbohydrates associated to plant immunity, their role and mode of action. More precisely, the state of the art about perception of "PAMP, MAMP, and DAMP (Pathogen-, Microbe-, Damage-Associated Molecular Patterns) type" oligosaccharides is presented and examples of induced defense events are provided. A particular attention is paid to the structure/activity relationships of these compounds. The role of sugars as…

High pressure processing of food-grade emulsion systems: Antimicrobial activity, and effect on the physicochemical properties

2019

Abstract The use of high pressure processing (HPP) for development of stable emulsion-based delivery systems has been recently increased. Under adequate conditions, application of high pressures modifies the functionality of protein and polysaccharide molecules and significantly promotes the emulsifying activities. Application of high pressures also modulates the emulsion microstructure without any destabilization and gelation of protein molecules. The lipid oxidation in HPP-treated emulsions can be accelerated, particularly with higher pressure levels, while the HPP utilization on emulsions in acidic conditions can highly inhibit the growth of spoilage and pathogenic microorganisms. In thi…

Solid-Phase Synthesis of a Sialyl-Tn-Glycoundecapeptide of the MUC1 Repeating Unit

1997

The synthesis of glycopeptides carrying tumour-associated antigens is of interest for cancer diagnosis and treatment. Here, a very efficient route lo disaccharide threonine building block 8 is presented which allows the introduction of the sialyl-Tn antigen into a peptide. The syntheses of the undecapeptide and the sialyl-Tn-containing glycoundecapeptide, which are a part of the repeating unit of MUC1, were performed by solid-phase synthesis with an allylic anchor cleavable under neutral conditions. After detachment from the resin, the peptide and the glycopeptide arc completely deprotected giving the target compounds 13 and 15, respectively.

Lentils enhance probiotic growth in yogurt and provide added benefit of antioxidant protection

2013

Abstract We evaluated the antioxidant potential of lentil polysaccharides in stimulating the growth of probiotic bacteria in yogurt. Microbial counts, pH and total titratable acidity (TTA) were measured in yogurt samples containing starter cultures with or without probiotic bacteria, supplemented with whole ground green lentils. Additionally, the antioxidant potential of polysaccharides extracted from green, red, and dehulled red lentils were measured by oxygen radical absorbance capacity (ORAC) assay. Results demonstrate that green lentils selectively enhanced the number of probiotic bacteria in yogurt in the initial stages of storage and maintained overall microbial counts (starter cultur…

α-L-rhamnosidases: Old and New Insights

2007

L-Rhamnose is a component of plant cell wall pectic polysaccharides (Mutter et al., 1994; Ridley et al., 2001), glycoproteins (Haruko and Haruko, 1999) and secondary metabolites such as anthocyanins (Renault et al., 1997), flavonoids (Bar-Peled et al., 1991) and triterpenoids (Friedman and McDonald, 1997). It has also been found in bacterial heteropolysaccharides (Hashimoto and Murata, 1998), rhamnolipids (Ochsner et al., 1994) and in the repeating units of the O-antigen structure of the lipopolysaccharide component of bacterial outer membranes (Chua et al., 1999). Some rhamnosides are important bioactive compounds, e.g. cytotoxic saponins (Bader et al., 1998; Yu et al., 2002), antifungal p…

Influence of some physicochemical factors on the viscosity of aqueous levan solutions ofZymomonas mobilis

1998

Zymomonas mobilis strain 113 “S” produces levan – an extracellular, viscous, biologically active, non-toxic fructose polymer with a unique structure and extraordinary properties. This polysaccharide was isolated at two different degrees of purity by alcohol precipitation from aqueous solutions and was characterized with respect to some rheological properties and stability of viscous solutions. The effects of temperature, pH and salt concentration on the viscosity of 1–3% levan solutions were examined. The viscosity of levan solutions was found to be quite stable and reversible at room temperature over a wide range of pH from 4 to 11. The viscosity was slightly affected by increased salt con…

Alkaline Pre-treatment of Hardwood Chips Prior to Delignification

2013

Scots pine (Pinus sylvestris) chips were pre-treated with alkaline solutions (alkali charges of 1, 2, 3, 4, 6, and 8% of NaOH on the oven-dried wood material) at 130°C and 150°C for various treatment times (30, 60, 90, and 120 minutes). Under these conditions, 2.0–13.6% of the wood d.s. was dissolved into the aqueous hydrolysates. The soluble organic fraction was primarily characterized in terms of carbohydrates (monosaccharides and oligo-/polysaccharides) and their alkali-catalyzed degradation products: aliphatic carboxylic acids containing, besides non-volatile hydroxy carboxylic acids, volatile formic and acetic acids. With increasing alkali charge, temperature, and time, the enhanced fo…