Oligosaccharides verbascose

In 1910, Bourquelot and Bridel reported17 the isolation of a new oligosaccharide, verbascose, from the roots of the mullein, Verbascum thapsus. 

Fig. 1.—Molecular-rotation relationships of several raffinose-type oligosaccharides. Me, methyl a-D-galactopy ranoside Gl, D-glucose Mb, melibiose Mt, manninotriose Vt, verbascotetraose S, D-glucitol M, melibiitol Ml, manninotriitol Su, sucrose K, raffinose St, stachyose V, verbascose Gb, gentiobiose Ge, gentianose.

Recently, French33 has been able to prepare verbascotetraitol in crystalline form, by separation of the reduced oligosaccharides from ash manna. Likewise, the trisaccharide galactotriose, which is a component moiety in verbascose, has been obtained33 as a crystalline material. Although these compounds may eventually prove to be valuable reference compounds in the detailed examination of the verbascose structure, definitive, structural studies on these new compounds are as yet lacking. 

Raffinose series of oligosaccharides, (a) sucrose, (b) raffinose, (c) stachyose, (d) verbascose, (e) aungose... 

The complete analysis of foodstuffs may require the determination of simple sugars and reducing sugars (fructose, glucose, galactose, sorbitol, maltose, lactose), oligosaccharides (sucrose, raffinose, stachyose, verbascose), polysaccharides (starch, cellulose, etc.), and fibers, which vary in amovmt/ form and all of which may play an important role in the quality of the product. Methods of... 

Oligosaccharides in legumes are present in higher concentration than in cereals. Predominant in this fraction are sucrose, stachyose and verbascose (Table 16.21). 

The defatted toasted soya flour can be upgraded to a concentrate (70 % protein) by removing soluble material by leaching with water, or better still, with aqueous alcohol. This removes the oligosaccharides, sugars with 2-5 hexose units, i.e. sucrose, raffinose, stachyose and verbascose. Of these, the last three are recognised as flatus factors since it has been demonstrated that their metabolism involves intestinal gas production. 

Naturally occurring tri- and higher oligosaccharides (less than 10 sugar units) are rare. Rafifinose (3), stachyose (4), and verbascose (5) are all assembled on a sucrose core with substituents originating on the glucose moiety. 

The other major breakdown products of carbohydrate fermentation are hydrogen, methane, and carbon dioxide, which together comprise flatus gas. Excess gas production can cause distension and pain in some individuals, especially if they attempt to increase their fiber consumption too abruptly. In most cases, however, extreme flatus is probably caused more by fermentation of oligosaccharides such as stachyose and verbascose, which are fovmd principally in legume seeds, rather than the cell wall polysaccharides themselves. 

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