Polysaccharides

Gum Jhingan is a modified carbohydrate with a fluorinated saccharide. It is an oligosaccharide that has been synthesized from the sugar galactose. Gum Jhingan is a high-purity, custom-synthesized product that has been methylated and glycosylated. The modification process of this carbohydrate includes fluorination and click chemistry.

Xanthan gum is a polysaccharide produced by the Gram negative bacteria Xanthomonas campestris. It has unique rheological and gel forming properties and finds many applications particularly in the food and oil industries. Recently, it has been shown that ternary mixtures of konjac glucomannan, xanthan gum and sodium alginate can form a non-covalently linked complex which exhibits enhanced rheological properties of value in, for example, functional foods. The structure of xanthan is based on a cellulosic backbone of β-(1,4)-linked glucose units which have a trisaccharide side chain of mannose-glucuronic acid-mannose linked to every second glucose unit in the main chain. Some terminal mannose units are pyruvylated and some of the inner mannose units are acetylated.

Applications 3-O-Methyl-d3 Quercetin is the labeled analogue of 3-O-Methyl Quercetin (M326545), a metabolite of the flavanoid Quercetin (Q509500) with inhibitory activity on lipopolysaccharide-induced activation of macrophage U937 cells. Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package References Okoko, T. et al.: Food Chem. Toxicol., 47, 809 (2009); Duenas, M. et al.: Eur. Food Res. Technol., 232, 103 (2011); Marzouk, M. et al.: Phytochem., 52, 943 (1999)

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.

Ulvans are structural polysaccharides present in the cell walls of green algae such as Ulva armoricana, Ulva rotondata, Ulva rigida, Ulva lacterca and Ulva pertusa. They are highly sulphated and contain rhamnose 3-sulphate, xylose, xylose 2-sulphate, glucuronic acid and iduronic acid residues. Ulvan has several potentially valuable functionalities such as gel formation for agricultural and food applications and possible anticoagulant, antioxidant, antihyperlipidemic and antitumoral activities for pharmaceutical applications. The image was kindly provided by Prof Mike Guiry from Cork who runs ‘The Seaweed Site’.

Sodium carboxymethyl dextran is a white, odourless and tasteless powder, which is freely soluble in water or electrolyte solutions. Applications that have been described for carboxymethyl dextran include carriers of paramagnetic contrast agents, preparation of conjugates of pharmacologically active compounds and carboxymethyl dextrans in biosensors.  A number of other uses in cosmetics, agriculture, foods, paints and textiles have been the subject of patent applications.

Anterograde and retrograde tracer in neurons; biologically inert

A fucan sulphate found in brown marine algae (Phaeophyta-typically Fucus serratus, Ascophyllum nodosum, Laminaria digitata (illustrated) and Macrocystis pyrifyra) 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 image was kindly provided by Prof Mike Guiry from Cork who runs ‘The Seaweed Site’.

An apiose-rich pectic polysaccharide zosterin is found in the sea grass Zostera marina and is typical of similar structures occurring in higher plants. The structure consists of an α-1,4-D-galactopyranosyluronan backbone substituted by 1,2-linked apiofuranose oligosaccharides and single apiose residues. The average molecular mass of the polysaccharide has been shown to be about 4100 Da with a low polydispersity.

Gycosaminoglycan in many organs; joint lubricant and shock absorber

Curdlan is a microbial polysaccharide produced by a mutant strain of Alcaligenes faecalis var. myxogenes which was first shown to produce succinoglucan prior to mutation. Curdlan is a β-1,3 glucan forming clear solutions at about 55 °C which then gels (“low-set”) when cooled. Suspensions of curdlan at higher temperatures form firm resilient gels (“high set”) that melt at 140 - 160 °C. The image was kindly provided by Dr. Chris Lawson.