Polisaccaridi

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 ca 6000 - 8000Da.poly-M levels are ca 3%

Laminaran is a polysaccharide that co-occurs with fucoidan and alginate in brown seaweeds such as Laminaria digitata, Laminaria cloustoni, Eisenia bicyclis and Thallus laminariae. It is a β-1,3-linked glucan which it is claimed stimulates the immune system in mammals and fish.
The image was kindly provided by Prof Mike Guiry from Cork who runs ‘The Seaweed Site’.

Arabinoxylans consist of α-L-arabinofuranose residues attached as branch-points to β-(1,4)-linked D-xylopyranose main chains. These may be 2- or 3-substituted or 2- and 3- di-substituted. The arabinose residues may also be linked to other groups attached such as glucuronic acid residues, ferulic acid cross links and acetyl groups. Arabinoxylans generally consist of between 1500 - 5000 residues.

Guar gum is obtained from the seed of the legume Cyamopsis tetragonolobus, an annual plant that grows mainly in semi-arid regions of India. The structure of the polysaccharide consists of a main chain of (1,4)-linked β-D-mannopyranosyl units with single α-D-galactopyranosyl units linked (1,6) on average to every second main chain unit. Guar has a high viscosity in aqueous solution, shows marked pseudoplastic behaviour and forms synergistic gels in the presence of other gums such as carrageenan and xanthan gum.

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.

Amylopectin is composed of between 2,000 to 200,000 glucose residues linked α (1→4) with α (1→6) branching. The molecule is highly branched, every 24 to 30 glucose units, resulting in a soluble molecule with many terminal residues. Starch is made of about 70% amylopectin by weight, though it varies depending on the source (higher in medium-grain rice to 100% in glutinous rice, waxy potato starch, waxy corn, and lower in long-grain rice, amylomaize, and russet potatoes).

Gum karaya is exuded from Sterculia urens, a bushy tree found in dry regions of North India. Due to its extensive swelling capacity in water it is used as a laxative and as a denture adhesive. The structure consists of D-galactose, D-glucuronic acid and L-rhamnose but the detailed molecular structure is still incompletely known.

Pectins are regarded as linear chains of α-1,4-linked D-galacturonic acid, a homogalacturonan (pectic acid). In the products of commerce, the degree of methylation has a vital influence on the properties of pectin, especially the solubility and gel forming characteristics.