Levan | Pharmaceutical Grade | 99.99% Purity | CAS 9013-95-0

Levan:Basic information

Applications and Synthetic Methods
Overview
Fructans are linear and/or branched polymers composed of fructose, serving as key storage carbohydrates in approximately 15% of angiosperms (Hendry, 1993). Research on fructans worldwide dates back to 1804, spanning roughly 200 years to the present (Rose, 1804). Early studies primarily focused on the physiological and biochemical properties of fructans. Following the discovery of enzymes involved in fructan metabolism, research focus shifted toward understanding fructan metabolic pathways and their biological functions (Pollock and Cairns, 1991).
Physiological Functions
Short-term storage of carbohydrates;
Regulation of sucrose pool size in photosynthetic tissues;
Maintenance of proper water potential in plant tissues via osmotic adjustment;
Depolymerization into fructose molecules lowers the freezing point of tissue water, improving plant cold tolerance;
Sustaining plant photosynthesis under low temperatures. It is well documented that starch-accumulating plants experience a dramatic drop in photosynthetic rate under cold conditions. By contrast, fructan-accumulating plants maintain stable photosynthetic rates even at 0 °C, supporting normal plant growth.
Classification
Fructans are polymers formed by linking sucrose with one or more fructose moieties, predominantly found in bacteria and higher plants. Bacterial fructans belong to the levan-type fructans, a class of extracellular polysaccharides with molecular weights 2 to 3 times higher than those of plant-derived fructans. Fructans from higher plants feature highly complex structures with widely variable chain lengths, generally consisting of 30 to 50 fructosyl units; their degree of polymerization (DP, the number of fructosyl residues) can sometimes exceed 200. The shortest fructan is trisaccharide kestose.
Applications
Fructans are indigestible by human digestive enzymes. They act as dietary fiber, help reduce cariogenic risks for oral health, and serve as a substrate for beneficial intestinal microorganisms.