Lichenin, also known as lichenan or moss starch, is a complex

glucan A glucan is a polysaccharide derived from D-glucose, linked by glycosidic bonds. Glucans are noted in two forms: alpha glucans and beta glucans. Many beta-glucans are medically important. They represent a drug target for antifungal medications of ...

occurring in certain species of

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s. It can be extracted from ''Cetraria islandica'' ( Iceland moss). It has been studied since about 1957.

Structure

Chemically, lichenin is a mixed-linkage glucan, consisting of repeating

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

units linked by β-1,3 and β-1,4 glycosidic bonds.

Uses

It is an important carbohydrate for

reindeer The reindeer or caribou (''Rangifer tarandus'') is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, taiga, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only re ...

s and

northern flying squirrel The northern flying squirrel (''Glaucomys sabrinus'') is one of three species of the genus '' Glaucomys'', the only flying squirrels found in North America.Walker EP, Paradiso JL. 1975. ''Mammals of the World''. Baltimore: Johns Hopkins Universit ...

s, which eat the lichen '' Bryoria fremontii''. It can be extracted by digesting Iceland moss in a cold, weak solution of carbonate of soda for some time, and then boiling. By this process the lichenin is dissolved and on cooling separates as a colorless jelly.

Iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

imparts no color to it.

Other uses of the name

In his 1960 novel '' Trouble with Lichen'',

John Wyndham John Wyndham Parkes Lucas Beynon Harris (; 10 July 1903 – 11 March 1969) was an English science fiction writer best known for his works published under the pen name John Wyndham, although he also used other combinations of his name ...

gives the name ''Lichenin'' to a biochemical extract of lichen used to extend life expectancy beyond 300 years.

References

Polysaccharides Lichen products {{lichen-stub