Polysaccharides tragacanth

Gum tragacanth is a mixture consisting of a salt of a complex acidic polysaccharide (tragacanthic acid) and a neutral polysaccharide which contains arabinose units. It is the latter which probably accounts for the isolation of arabinose from the crude gum. ... 

Keywords Agar, alginates, carrageenan, cellulose, chitin, chitosan, excipients, hemicelluloses, natural, pharmaceutical, polysaccharides, tragacanth... 

Gum tragacanth is obtained from the large tap root and branches of a small perennial shmb found in the Middle East, especially Iran. Chemically, it is a mixture of water-insoluble polysaccharides. It is stable to heat, acidity, and aging, and is used extensively in pourable low calorie salad dressings. 

Finally, the A. aculeatus preparation was found to contain an enzyme releasing the dimer B-Xylp-(l-3)-GalAj, from a soluble soy cell wall polysaccharide. The enzyme was partially purified and appeared to be active towards saponified MHR and gum tragacanth as well. It was concluded that this enzyme degraded the xylogalacturonan part in MHR by an exo-fashion. 

Other natural polysaccharides used as thickening agents include gum arabic, gum tragacanth and xanthan gum, but these are of diminishing significance nowadays. 

Polysaccharide materials Starch, cellulose, plant gums (arabic gum, tragacanth, karaya, ghatti, guar, locust bean, fruit tree gum) Paper, paint binders, adhesives... 

Although the pyrolysis of some classes of polysaccharide materials has been studied quite extensively in the food, petrol and tobacco industry, very little has been published specifically on polysaccharide binders (arabic gum, tragacanth gum, fruit tree gum, honey and starch). The pyrolysis of glucane based polymers, especially cellulose, has been studied in detail [6,55], highlighting how anhydrosugars and furan derivatives are the main pyrolysis products, together with one-, two- and three-carbon aldehydes and acids. 

The crude gum tragacanth is a mixture of the salt of a complex acid polysaccharide and a neutral polysaccharide composed principally of L-arabinose residues. Starch is also present in the gum. The acid character of this gum is due to units of D-galacturonic acid and not D-glucuronic acid and it is of interest to note that in its ability to form gels it resembles pectin and the plant mucilages, which also contain D-galacturonic acid. 

O-Methyl-L-fucose occurs as a constituent of plum-leaf polysaccharides,23 linseed mucilage,24 soybean polysaccharides,25 and gum tragacanth.26... 

GlcA-(l— 4)-l-Fuc was isolated from partial, acid hydrolyzates of soybean polysaccharide,134 the pectin of leaves of Tussilago,135 and tragacanthic acid,136 and a-L-Fuc-(l— 2)-D-Xyl was obtained from soybean polysaccharide.25... 

The natural polymers frequently used for the preparation of pharmaceutical gels include tragacanth, pectin, carrageenan, agar, and alginic acid, as well as semisynthetic polysaccharides such as methylcellulose, hydroxymethylcellulose, and carb-oxymethylcellulose. 

Because of their large interfacial area, emulsions are basically unstable. In order to produce a stable emulsion, a surfactant is mostly needed. The surfactants are adsorbed at the oil-water interface, forming a link between the two phases of different polarity. For this purpose, a wide variety of emulsifying agents is currently available. Polysaccharides such as arabic gum, tragacanth, Karaya gum, and different seaweed carbohydrate polymers have been employed. They, however, show considerable batch-to-batch variations and might support microbial growth. 

Belkin et al. 29> were first to examine various polysaccharide fractions from higher plants for their antitumor activity. They could demonstrate that many of these fractions produced haemorrhagic necrosis in different tumor types. In most cases, the polysaccharides were injected intraperitoneally into mice carrying Sarkoma 37 ascites tumor. The result was a progressive increase in cell volume and in cytoplasmic vacuolization. Osswald 30) found that tragacanth, gum arabic, and CMC reduced tumor cells in Ehrlich ascites carcinoma in female NMRE mice. The effect depended upon the dose, the route of injection, and the molecular size of the polysaccharides administered. 

Other polysaccharides have found widespread application Gums, which are complex, highly branched polysaccharides produced by plants, form very viscous solutions in water at low concentrations. Examples such as gum tragacanth have been used as thickening agents in foods in place of starch and to alter the texture of ice cream. 

Natural gums include plant exudates, seed gums, plant extracts, seaweed extracts, and the extracellular microbial polysaccharides. Plant exudates include gum arabic, gum ghatti, gum karaya, and gum tragacanth. Seed gums include... 

Gum tragacanth comes from the shrub Astragalus. Its major country of origin is Iran. The gum is normally available as yellowish pieces or as a spray dried powder. It is another polysaccharide polymer and is composed of glucuronic acid and arabinose, the molecular weight being around 840 000. It is odourless but has a mucilaginous taste. 

Tragacanthin A complex mixture of polysaccharides containing some galacturonic acid residues The soluble component of the natural (plant origin) tragacanth gum Binder (in tablets) and demulcent... 

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