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. Many beta-glucans are medically important. They represent a drug target for antifungal medications of the echinocandin class. Types The following are glucans: (The ...
occurring in certain species of
lichen A lichen ( , ) is a composite organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy ( ...

s. It can be extracted from ''Cetraria islandica'' (
Iceland moss ''Cetraria islandica'', or Iceland moss, is a lichen A lichen ( or, sometimes in the UK, , ) is a composite organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contigu ...
). It has been studied since about 1957.


Chemically, lichenin is a mixed-linkage glucan, consisting of repeating
glucose Glucose is a simple with the . Glucose is the most abundant , a subcategory of s. Glucose is mainly made by and most during from water and carbon dioxide, using energy from sunlight, where it is used to make in s, the most abundant carbohydr ...

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


It is an important carbohydrate for
reindeer The reindeer (''Rangifer tarandus''), also known as the caribou in North America, is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of northern Europe, Siberia, and North ...

s and
northern flying squirrel The northern flying squirrel (''Glaucomys sabrinus'') is one of three species of the genus '' Glaucomys'', the only flying squirrel Flying squirrels (scientifically known as Pteromyini or Petauristini) are a tribe of 50 species In biolo ...

northern flying squirrel
s, which eat the lichen '' Bryoria fremontii''. It can be extracted by digesting Iceland moss in a cold, weak solution of 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 In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical ele ...

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 Science fiction (sometimes shortened to sci-fi or SF) is a genre of speculative fiction which typically deals with imaginat ...
gives the name ''Lichenin'' to a biochemical extract of lichen used to extend life expectancy beyond 300 years.


Polysaccharides Lichenology {{lichen-stub