Starches Schardinger dextrins from

Note. The cyclic oligosaccharides arising from enzymic transglycosylation of starch have been referred to as Schardinger dextrins. These names (and those of the cyclohexaamylose type) are not recommended, but the abbreviation CD is tolerated. 

The first report in the literature of the isolation of a substance recognizable as a cyclodextrin was that of Villiers which appeared in 1891. From digests of Bacillus amylobacter on potato starch, Villiers obtained a small amount (3 g per 1000 g of starch) of a crystalline material, which he named cellulosine because of its resemblance in some respects to cellulose. The foundations of cyclodextrin chemistry were laid down, however, in the period 1903-1911 by Schardinger, and, in fact, some of the older literature frequently refers to the cyclodextrins as Schardinger dextrins. 

Prior to 1939, however, it was not known whether the cyclodextrins were products of the synthetic metabolism of Bacillus macerans, and therefore, perhaps, quite different from the components of starch, or whether they were formed by a single enzyme and therefore closely related to the starch structure. Then, Tilden and Hudson announced the discovery of a cell-free enzyme preparation from cultures of Bacillus macerans which had the ability to convert starch into the Schardinger dextrins without the production of maltose, glucose, or any other reducing sugars. They thus concluded that the Schardinger dextrins were either the true components of starch or closely related to such true components. 

While the enzymic approach must be refined and rationalized, present evidence is completely in accord with the concept of linear and branched structures for the two starch components. The theory has been advanced that the individual alpha and beta Schardinger dextrins originate from specific starch fractions, but this appears to be untenable. No satisfactory mechanism has been proposed to account for the production of the several crystalline dextrins. 

NUMBER OF D-GLUCOSE UNITS PER MOLECULE Fig. 25.—Chromatographic mobility of Schardinger dextrine ae compared with linear oligosaccharidee from starch. The values for the J- and e-dextrins were obtained from Fig. 9 and should be considered tentative. The ordinate (logarithmic scale) is the distribution function a as used by French and Wild. " ... 

At one time Freudenberg seriously proposed that starch is based upon a cyclic Schardinger dextrin nucleus, with side branches. In the bacterial breakdown, the branches would be broken off according to the following scheme (adapted from Freudenberg). 

Cyclodextrins, also called Schardinger dextrins, cycloamyloses, or cyclo-glucans, are a family of cyclic oligosaccharides obtained from starch and related compounds by the action of the amylase of Bacillus macerans. They were discovered by Villiers in 1891 [10] and the first detailed description of their properties and isolation was made by Schardinger in 1903 [11-13]. 

A. Villiers, Fermentation of starch by the but5ric ferment, Compt. Rend., 1891, 112, 536-538 F. Schardinger, Formation of crystaUine non-reducing polysaccharides from starch by microbic action. Cent. Bakt. Parasitenk. [II], 1909,22, 98-103 F. Schardinger, The formation of crystal-lin polysaccharides (dextrins) from starch paste by microorganisims, Cent. Bakt. Parasitenk. [II], 1911, 29, 188-197. 

Bacteria-free filtrates of Aerobadllus macerans (Bacillits macerans) produce from starch cyclic dextrins, known as Schardinger dextrins, in yields... 

Enzymes from Bacillus macerans act on either the linear or branched components of starch to form cyclic dextrins termed Schardinger dextrins... 

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