Polysaccharide acidic

Psyllium Seed Gum. PsyUium seed gum [8036-16-9] is derived from plants of the genus Plantago several species of which are used as commercial sources. However, most current production is from Plantago ovata grown in India. The gum is located in the coat which is removed by cracking. The gum is then extracted with boiling water and separated from the insoluble residue by filtration. It consists of mixtures of both neutral and acidic polysaccharides, the composition of which is species dependent (66). 

Ion Exchange. Acidic polysaccharides containing uronic acids, sulfate, or phosphate groups are cation exchangers, binding metal ions. The... 

Physica.1 Sta.bihty, Physical stabiHty depends primarily on the purity of the enzyme. Impurities remaining from the fermentation broth may precipitate or form a hazy solution. Unwanted sedimentation is often related to Ca " or acidic polysaccharides. The solubiHty of some enzymes can be increased by optimizing the ionic strength or changing the dielectric constant of the solution by a dding low molecular-weight polyols. 

Sephadex. Other carbohydrate matrices such as Sephadex (based on dextran) have more uniform particle sizes. Their advantages over the celluloses include faster and more reproducible flow rates and they can be used directly without removal of fines . Sephadex, which can also be obtained in a variety of ion-exchange forms (see Table 15) consists of beads of a cross-linked dextran gel which swells in water and aqueous salt solutions. The smaller the bead size, the higher the resolution that is possible but the slower the flow rate. Typical applications of Sephadex gels are the fractionation of mixtures of polypeptides, proteins, nucleic acids, polysaccharides and for desalting solutions. 

Separations of polysaccharides by fractionation on a preparative scale were also examined. Stemming from earlier work in his laboratory on the isolation of acidic polysaccharides by precipitation as their insoluble Cetavlon salts, Stacey and coworkers showed that it was possible to fractionate neutral polysaccharides by selective precipitation with Cetavlon after the formation of borate complexes. 

Observations on the Properties of Cetyltrimethylammonium Salts of some Acidic Polysaccharides, ... 

Acanthus ebracteatus is a plant traditionally used for various ailments, amongst those skin diseases in Thai traditional medicine. The stem of the plant was shown to contain neutral and acidic polysaccharides with effect in... 

Resistance to phagocytosis is sometimes associated with specific components of the cell wall and/or with the presence of capsules surrounding the cell wall. Classic examples of these are the M-proteins of the streptococci and the polysaccharide capsules of pneumococci. The acidic polysaccharide K-antigens of Escherichia coli and Sal typhi behave similarly, in that (i) they can mediate attachment to the intestinal epithelial cells, and (ii) they render phagocytosis more difficult. Generally, possession of an extracellular capsule will reduce the likelihood of phagocytosis. 

Crude polysaccharide fraction (GL-2) was prepared from the leaves of P. ginseng by hot water extraction, ethanol precipitation and dialysis, and GL-2 was fractionated by Cetavlon precipitation and weakly acidic polysaccharide fraction (GL-4) was obtained[3]. GL-4IIb2 was purified from GL-4 by DEAE-Sepharose CL-6B as described previousely [3]. In order to remove the color-materials, GL-4IIb2 was further purified by Q-Sepharose (C1 form), and the major fraction, eluted with 0.3 M NaCl, was repurifled by gel filtration on Bio-gel P-30 column to obtain purified active polysaccharide, GL-4IIb2. ... 

Polymers are examples of organic compounds. However, the main difference between polymers and other organic compounds is the size of the polymer molecules. The molecular mass of most organic compounds is only a few hundred atomic mass units (for reference, atomic hydrogen has a mass of one atomic mass unit). The molecular masses of polymeric molecules range from thousands to millions of atomic mass units. Synthetic polymers include plastics and synthetic fibers, such as nylon and polyesters. Naturally occurring polymers include proteins, nucleic acids, polysaccharides, and rubber. The large size of a polymer molecule is attained by the repeated attachment of smaller molecules called monomers. 

Volume 203. Molecular Design and Modeling Concepts and Applications (Part B Antibodies and Antigens, Nucleic Acids, Polysaccharides, and Drugs) Edited fey John J. Langone... 

Pectin is used in foods in two forms, high methoxyl pectin and low methoxyl pectin. High methoxyl pectin is the form normally found in fruit while low methoxyl pectin is a chemically modified pectin. Pectins are acidic polysaccharides that occur in the cell walls of fruit. The commercial source of pectin is either citrus peel or apple pomace. The citrus peel is the residue from the production of citrus juices while apple pomace is the residue of cider production. Thus pectin is a by-product of either cider or fruit juice production. 

Avigad and Milner224 used a turbidimetric method based on the measurement of residual turbidity caused by complexing the acid polysaccharide with such quaternary ammonium detergents as cetyl-pyridinium bromide. The activity unit was expressed as the amount of enzyme bringing about a decrease of absorbance at 400 nm of 0.01/min. 

Kim, K.H. et al., Acidic polysaccharide from Panax ginseng, ginsan, induces Thl cell and macrophage cytokines and generates LAK cells in synergy with rIL-2, Planta Med, 64, 110, 1998. 

Shin, J.Y. et al., Immunostimulating effects of acidic polysaccharides extract of Panax ginseng on macrophage function, Immunopharmacol Immunotoxicol, 24, 469, 2002. 

Several other properties of selected dietary fibers may influence the bioavailability of calcium directly or indirectly. Those fibers which have cation exchange capabilities such as acid polysaccharides due to free carboxyl groups on the sugar residues may bind minerals such as calcium (3,17,33,36). Loss of calcium binding protein as a result of mucosa injury caused by the feeding of some kinds of dietary fiber was credited as being the partial cause of decreased calcium absorption in everted, rat gut sac studies by Oku et al. (16). 

Figure 14.2 Representative oligosaccharide structures found on mammalian glycoproteins and glycolipids. The complex oligosaccharides may be bi-, tri-, or tetra-antennary the branches may be more or less elongated with 1—>4 linked lactosamine units, and they may or may not be sialylated. The SLex, Lea, and Leb structures represent the different blood group determinants often present on lipids, and the elongated core 2 structure is a mucin-type glycosylation. Proteoglycans have a common core to which a variety of linear acidic polysaccharides are attached.

S. Xu and M. Yonese, in Charge Densities and Nanoparticle Formation of Complexes Composed of Acid Polysaccharides and Protein, Nagoya, Japan, 1998, p. E1076. 

Hope, D.B. and Kent, P.W., Ester and lactone linkages in acidic polysaccharides. Part II. Lactones of D-glucosaminic acid. J. Chem. Soc. Abstr., 1955, 1831. 

Big molecules of life include the proteins, nucleic acids, polysaccharides, and a few other more exotic constrncts of nature. Generally, it is the interactions between big molecules and small ones that nnderlie really interesting things taste or smeU or the beneficial actions of drugs, for example. 

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