果聚糖,Levan

Levan, also known as fructan or levan N, belongs to the class of organic compounds known as o-glycosyl compounds. These are glycoside in which a sugar group is bonded through one carbon to another group via a O-glycosidic bond. Levan is soluble (in water) and a very weakly acidic compound (based on its pKa). Levan has been found in human tongue, tooth and pancreas tissues. Within the cell, levan is primarily located in the cytoplasm.

Levan is a (2,6)-linked fructan produced by Erwinia herbicola. The polysaccharide contains branches every 10-12 fructose residues linked (1,2) and is reported to have a molecular weight in excess of 1000 KDa.  Potential industrial applications of levan have been proposed as an emulsifier, formulation aid, stabilizer and thickener, surface-finishing agent, encapsulating agent, and carrier for flavor and fragrances. In addition, levan is promising in medicine as a plasma substitute, drug activity prolongator and antihyperlipidemic agent.