Mucilages neutral

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. 

The algal polysaccharides resembled the relatively simplified structures of tile neutral mucilages, as in the case of carrageenan A wider spectrum of struclures is found in Ihc bacterial gums, which arc generally of the highly branched type exuded by higher plants,... 

Opium contains 20 alkaloids in combination with meconic, lactic, and sulfuric acids the neutral principles are meconin and meconoiasin, besides glucose, mucilage, resin, pectin, caoutchouc,... 

Flaxseed mucilage, associated with hull of flaxseed, is a gum-like material and composed of acidic and neutral polysaccharides. The neutral fraction of flaxseed mainly contains xylose (62.8%), whereas the acidic fraction of flaxseed is comprised mainly of rhamnose (54.5%), followed by galactose (23.4%) (Cui et al., 1994a). A study by Warrand et al. (2005) found that the neutral monosaccharides were a mixture of three major families of polymers, arabinoxylans with a constant A/X ratio of 0.24, and various amount of galactose and fucose residues in the side chains. Acidic hydrolysis yields xylose, galactose, arabinose, rhamnose, galacturonic acid, fucose, and glucose (BeMiller, 1973 Erskine and Jones, 1957). 

Warrand, J., Michaud, P., Picton, L., Muller, G., Courtois, B., Ralainirina, R., and Courtois, J. 2005. Structural investigations of the neutral polysaccharide of Linum usitatissimum L. seeds mucilage. I nr J. Biol. Macromol. 35, 121-125. 

The closely related mucilages are widely distributed in intercellular material and in the cell contents, and they possess the same type of molecular structure as the gums. Mucilages may be either neutral or acidic (when uronic acid residues are present). Again, little is known of the finer details of molecular structure and it is often difficult to prove whether or not the material is homogeneous. 

Electrophoresis. —The use of the free boundary method, in which molecules migrate in solution under the influence of an applied electric field, has found limited application to polysaccharide solutions as a separation method. This applies even to acidic polysaccharides, such as plant gums and mucilages, bacterial polysaccharides, and mucopolysaccharides, which will migrate directly. Electrophoretic separation of neutral polysaccharides in alkali appears to be limited to a gross separation of neutral... 

Figure 8. Shear dependence of neutralized type B polymer mucilages.

Caesalpinia spinosa (Molina) Kuntze [1], commonly known as tara, is a leguminous shrub [2] native of Peru. It is cultivated as a source of tannins and is cultivated as an ornamental plant because of its colorful flowers and inflorescences. C. spinosa is in the family Fabaceae. It is distributed in the northern and central of South America. Some scientific synonyms are Caesalpinia tinctoria, Poinciana spinosa, Caesalpinia pectinata, Coulteria tinctoria, Tara tinctoria, and Caesalpinia stipulata. It is also known by various common names such as taya, tara, guarango, cuica, vinilo, vainillo, acacia amarilla, and divi divi. It contains polysaccharide derivatives of mannose (neutral mucilage). C. spinosa produces a alactomannan... 

Polyuronides macromolecular compounds found in plants, consisting of units of uronic acids in the pyr-anose form (see Carbohydrates). The main components are o-glucuronic acid, o-galacturonic acid and D-mannuronic acid. P. contain free carboxyl groups and are consequently more strongly hydrated than polysaccharides formed from neutral monosaccharides. Examples are pectins, alginic acid and plant mucilages. 

---