Polysaccharides

Xyloglucans are members of a group of polysaccharides typically refered to as hemicelluloses. Hemicelluloses are plant cell wall polysaccharides that are not solubilized by water but are solubilized by aqueous alkali (e.g. 1 and 4M KOH). Other hemicellulosic polysaccharides include xylan, glucuronoxylan, arabinoxylan, mannan, glucomannan and galactoglucomannan. Hemicelluloses have a backbone of 1,4-linked β-D-pyranosyl residues in which O4 is in the equatorial orientation (e.g. Glc, Man, and Xyl). Xyloglucan is the predominant hemicellulose in the primary walls of dicots and non-graminaceous monocots and may account for up to 20% of the dry weight of the primary wall. Xyloglucan has a backbone composed of 1,4-linked β-D-Glcp residues. Up to 75% of these residues are substituted at O6 with mono-, di-, or triglycosyl side chains.

Carboxymethyl chitosan has good solubility in water and unique chemical, physical and biological properties such as high viscosity, large hydrodynamic volume, low toxicity, biocompatibility and good ability to form films, fibres and hydrogels. For this reason, it has been extensively used in many biomedical fields such as a moisture-retention agent, bactericide, wound dressing agent, in artificial bone and skin, as blood anticoagulant and as a component in different drug delivery matrices. The reactive ligands COOH and NH2 groups are available for metal chelation and dye binding.

The extracellular polysaccharide produced by Arthrobacter stabilis NRRL B-3225 contains D-glucose, D-galactose, pyruvic acid, O-succinyl, and O-acetyl in the approximate molar ratio of 6:3:1:1:1.5. Succinyl is linked as its half-ester, making it readily removable. The viscosity of aqueous, salt-free solutions of both native and deacylated polymer is relatively low, but atypical of anionic polysaccharides, increases rapidly in the presence of salts, acids, or alkali.

In water, hydroxypropyl cellulose forms liquid crystals with many mesophases depending on concentration. These mesophases include isotropic, anisotropic, nematic and cholesteric, the latter resulting in many colors such as violet, green and red. Pharmaceutical applications include treatments for medical conditions such as dry eye syndrome (keratoconjunctivitis sicca), recurrent corneal erosions, decreased corneal sensitivity, exposure and neuroparalytic keratitis. It is also used as a binder in tablets. Hydroxypropylcellulose is also used as a thickener, a binder and emulsion stabiliser in foods with E number E463.  HPC is used as a support matrix for DNA separations by capillary and microchip electrophoresis.

Quaternization of the primary amine in N-Trimethylchitosan increases the water solubility of chitosan and keeps chitosan soluble over a wide pH range. N-Trimethylchitosan is soluble in water and ethanol, making it ideal for use in biotechnology applications.The degree of quaternization is 30-70%