Polyfructosans

Many plants store carbohydrates in their tubers in the form of polysaccharides which upon acid hydrolysis yield D-fructose as the main product. These polysaccharides differ from one another in the size of the molecule as well as in the position of the linkages between the D-fructose residues. Polyfructosans have also been prepared by enzymic action on sucrose. 

A large number of polyfructosans that have been reported from time to time by different authors have been investigated by Schlubach and his associates. In order to obtain polysaccharides of constant optical rotation, 100 to 300 precipitations from aqueous solution by the addition of alcohol were necessary. Fifty to 150 precipitations from chloroform solution with petroleum ether were required for purification of the acetate derivatives. These were methylated according to the procedure of Haworth and Straight,24 and upon hydrolysis partially methylated fructoses were obtained. 

It is believed by Schlubach and Sinh35 that the polyfructosans are, as a rule, made up of D-fructose residues joined in a ring. According to these authors, when the methyl derivatives of the polysaccharides are hydrolyzed, the amounts of dimethyl- and tetramethyl-D-fructose formed... 

The polyfructosans, in contrast to the difructose anhydrides, are readily hydrolyzed in acid solution. Schlubach and his associates86 have measured the rates of hydrolysis of a large number of polyfructosans. The time required for 50% hydrolysis to take place in N sulfuric acid solution at 20° is recorded in Table III. These results are based on... 

Half Periods for Hydrolysis of Polyfructosans in N Sulfuric Acid at 20° C. Data of Schlubach and Sinh ... 

Taylor H. Evans and Harold Hibbert, Bacterial Polysaccharides 203 E. L. Hirst and J. K. N. Jones, The Chemistry of Pectic Materials 235 Emma J. McDonald, The Polyfructosans and Difructose Anhydrides 253 Joseph F. Haskins, Cellulose Ethers of Industrial Significance. 279... 

Polyfructosans. See Fructans. Polyglycosiduronic acids. See Glyco-siduronic acids, poly-. Polysaccharides. See also, Carbohydrates,... 

Ben Chekroun, M., Evolution hivemale des glucides (inuline et polyfructosanes) dans les tubercules de topinambour (Helianthus tuberosus L.) et la racine de chicoree (Cichorium intybus L.), These Uni-versite de Limoges, Limoges, France, 1990, p. 146. 

Schlubach, H.H., Huchting, I., and Muller, H., Untersuchungen iiber Polyfructosane. XXVIII. Uber die Kohlenhydrate der Topinambour. III. Uber das Synanthrin A, Justus Liebig s Annalen Chemie, 577, 47-53, 1952. 

The method described involves hydrolysis of Jerusalem artichoke polyfructosan and thermal treatment. The method enables increased fructose content to be obtained. It may be used for the treatment of patients suffering diabetes mellitus and obesity. 

McDo.nald, Emma j.. The Polyfructosans and Difructose Anhydrides, 2, 253-277... 

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