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 composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Iceland moss ''Cetraria islandica'', also known as true Iceland lichen or Iceland moss, is an Arctic-alpine lichen whose erect or upright, leaflike habit gives it the appearance of a moss, where its name likely comes from. Description It is often of a pale ...

). It has been studied since about 1957.

Structure

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

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

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

Uses

It is an important carbohydrate for reindeers 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 with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vio ...

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 names ...

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

References

Polysaccharides Lichen products {{lichen-stub