lichenin
{{chembox
| Verifiedfields = changed
| verifiedrevid = 433643349
| ImageFile = Beta-1,3-1,4-glucan.png
| IUPACName =
| OtherNames = Lichenan; Moss starch
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 1402-10-4
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = M7F3LRN53I
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 6452
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = none
| PubChem = 439241
| PubChem_Comment = monomer
| SMILES = }}
|Section2={{Chembox Properties
| Formula = (C6H10O5)x
| MolarMass = Variable
| Appearance =
| Density =
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|Section3={{Chembox Hazards
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Lichenin, also known as lichenan or moss starch, is a complex glucan occurring in certain species of lichens. It can be extracted from Cetraria islandica (Iceland moss).{{cite journal |last1=Perlin |first1=A. S. |last2=Suzuki |first2=S. |year=1962 |title=The Structure of Lichenin: Selective Enzymolysis Studies |journal=Canadian Journal of Chemistry |volume=40 |issue=1 |pages=50–56 |publisher=National Research Council of Canada |location=Canada |doi=10.1139/v62-009|doi-access=free }} It has been studied since about 1957.{{cite journal |last1=Cunningham |first1=WL |last2=Manners |first2=DJ |date=March 1964 |title=Studies on carbohydrate-metabolizing enzymes. 11. The hydrolysis of lichenin by enzyme preparations from malted barley and Rhizopus arrhizus |journal=The Biochemical Journal |volume=90 |issue=3 |pages=596–602 |publisher=Portland Press on behalf of the Biochemical Society |location=England |issn=0264-6021 |pmid=5833367 |pmc=1202740 |doi=10.1042/bj0900596}}
Structure
Chemically, lichenin is a mixed-linkage glucan, consisting of repeating glucose units linked by β-1,3 and β-1,4 glycosidic bonds.
Uses
It is an important carbohydrate for reindeers and northern flying squirrels, 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 imparts no color to it.{{NIE|wstitle=Lichenin|year=1905|inline=1}}
Other uses of the name
In his 1960 novel Trouble with Lichen, John Wyndham gives the name Lichenin to a biochemical extract of lichen used to extend life expectancy beyond 300 years.