Polysaccharides

An alginate-like polysaccharide produced by the fermentation of Azotobacter vinelandii or Pseudomonas mendocina. The chemical structure consists of blocks of (1,4) linked-β-D-polymannuronic acid (poly M), (1,4) linked-α-L-polyguluronic acid (poly G) and alternating blocks of the two uronic acids (poly MG). Unlike the alginate from seaweed, this polysaccharide is partially acetylated.

Rhamnogalacturonan is a natural polysaccharide that is a major component of plant cell walls. It can be synthesized in the laboratory and modified with different functional groups to alter its properties. Rhamnogalacturonan has been shown to have anti-inflammatory, antioxidant, and immunomodulatory activities. It also has the ability to inhibit bacterial growth and stimulate phagocytosis by macrophages. This product has a high purity, is custom synthesized, and can be modified with different functional groups.

Polyguluronic acid is produced from alginates by partial hydrolysis and chromatography of brown algae such as Laminaria digitata, Ascophyllum nodosum and Fucus spp. The image was kindly provided by Prof Mike Guiry from Cork who runs ‘The Seaweed Site’.MW is less then 8000Da.

Gellan is a microbial polysaccharide produced by Pseudomonas elodea and generates gels with similar properties to agar. Gellan gum is a linear tetrasaccharide of (1,4)-β-L-rhamnopyranosyl, (1,3)-α-D-glucopyranosyl, (1,4)-β-D-glucuronopyranosyl, (1,4)-β-D-glucopyranosyl- with O(2) L-glyceryl and O(6) acetyl substituents on the 3-linked glucose. Both substituents are located on the same glucose residue, and on average, there is one glycerate per repeat and one acetate per every two repeats. In low acyl gellan gum, the acyl groups are removed completely. The high acyl form produces soft, elastic, non-brittle gels, whereas the low acyl form produces firm, non-elastic, brittle gels.

Chitosan is the deacetylated form of chitin.  The polysaccharide is deacetylated in order to render it soluble, which is then possible at pH values of less than 7 (normally in dilute acid).  This then allows the material to be used in a number of industrial applications as a binder and film former.

Chitosan is the deacetylated form of chitin. The polysaccharide is deacetylated in order to render it soluble, which is then possible at pH values of less than 7 (normally in dilute acid). This then allows the material to be used in a number of industrial applications as a binder and film former.

Pectin is a highly complex polysaccharide matrix that is found in the primary walls of dicotyledenous and monocotyledenous plants and gymnosperms, including soy plants. A key fragment of this complex is rhamnogalacturonan I, containing a backbone of the repeating disaccharide  [-4)-α-D-GalpA-(1,2)-α-L-Rhap-(1,]. Several applications for RG1 have been described including drug targeting to the colon via the oral administration route for local treatment of e.g. inflammatory bowel disease and colonic cancer. This has several advantages such as needle-free administration and low infection risk and in the gastro-intestinal tract RG-I is only degraded by the action of the colonic microflora.  High purity rhamnogalacturonan I is also used in research, biochemical enzyme assays and in vitro diagnostic analysis.

Fluorescein isothiocyanate carboxymethyl dextran (FITC-CM Dextran) has been reported to provide a valuable carrier for nanoparticles of iron oxide.  These products provide a potent tool for contrast enhancement in magnetic resonance imaging.