Polysaccharides

A fucan sulphate found in brown marine algae (Phaeophyta-typically Fucus vesiculotus, Ascophyllum nodosum, Alaria and Macrocystis pyrifyra (illustrated) and has been shown to have anticoagulant activity. The main constituents are α-1,4 and α-1,2 linked L-fucose sulphates, although galactose also occurs and there are many variations of the basic structure found in different species of Phaeophyta.
The fucose content of this fucan is approx. 31% and it also contains galactose (approx. 2.2%), uronic acid (approx. 12.4%) and sulfate (approx. 32.5%).
The image was kindly provided by Prof Mike Guiry from Cork who runs ‘The Seaweed Site’.

Sugar beet arabinan consists of a 1,5 α-linked arabinose backbone to which 1,3 α-linked (and possibly some 1,2 α-linked) L-arabinofuranosyl residues are attached. Approximately 60% of the main-chain arabinofuranosyl residues are substituted by single 1,3-linked arabinofuranosyl groups. The reducing terminal arabinosyl residue is attached through rhamnose to fragments of the rhamnogalacturonan backbone of the native pectin molecule.

Dextran sulphate is a dextran derivative whose ulcer (colitis) -causing properties were first reported in hamsters and extrapolated a few years later to mice and rats. The exact mechanisms through which dextran sulphate induces intestinal inflammation are unclear but may be the result of direct damage of the monolayer of epithelial cells in the colon, leading to the crossing of intestinal contents (for e.g. commensal bacteria and their products) into underlying tissue and therefore induction of inflammation.  The dextran sulphate sodium-induced ulceration model in laboratory animals has some advantages when compared to other animal models of colitis due to its simplicity and similarities to human inflammatory bowel disease. 
MW is in the range of 40,000Da

Dermatan sulphate is a glycosaminoglycan found in skin, blood vessels, heart valves, tendons, aorta, spleen and brain and is usually isolated from pig skin or beef lung tissue. The disaccharide repeat unit is composed of L-iduronic acid and N-acetyl-galactosamine-4-sulphate linked β-(1,3) and β-(1,4). There are also small amounts of D-glucuronic acid.

Chitin forms the tough fibrous exoskeletons of insects, crustaceans and other arthropods, and, in addition to its presence in some fungi, it occurs in at least one alga. The structure of chitin is similar to that of cellulose but with glucose replaced with N-acetyl-D-glucosaminyl units linked β-D-(1,4) in a linear chain. Chitin is normally produced from the shells of lobster, crab or shrimp.

Oat β-glucans are water-soluble β-glucans derived from the endosperm of oat kernels, which contain β-1,3 and β-1,4 linkages. They are known for cholesterol lowering and hypoglycemic properties, as well as their use in various cosmetic applications. Recent research has shown their potential application in immunomodulation and wound healing.

Dextran is α-(1,6)-linked α-D-glucan produced by fermentation of Leuconostoc mesenteroides via the action of the enzyme dextransucrase on sucrose. The main use for native dextran is as a blood plasma extender in blood transfusions. A complex of iron with dextran, known as iron dextran, is used as a source of iron to baby piglets which are often anaemic at birth.