Glucan
Encyclopedia
A glucan molecule is a polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...

 of D-glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

 monomers linked by glycosidic bond
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....

s.

Many beta-glucans are medically important.

Types

The following are glucans:
(The α- and β- and numbers clarify the type of O-glycosidic bond
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....

.)

Alpha

  • dextran
    Dextran
    Dextran is a complex, branched glucan composed of chains of varying lengths...

    , α-1,6-glucan with α-1,3-branches
  • glycogen
    Glycogen
    Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...

    , α-1,4- and α-1,6-glucan
  • pullulan
    Pullulan
    Pullulan is a polysaccharide polymer consisting of maltotriose units, also known as α-1,4- ;α-1,6-glucan'. Three glucose units in maltotriose are connected by an α-1,4 glycosidic bond, whereas consecutive maltotriose units are connected to each other by an α-1,6 glycosidic bond...

    , α-1,4- and α-1,6-glucan
  • starch
    Starch
    Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...

    , α-1,4- and α-1,6-glucan

Beta

  • cellulose
    Cellulose
    Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

    , β-1,4-glucan
  • curdlan
    Curdlan
    Curdlan is a high molecular weight polymer of glucose. Curdlan consists of β--linked glucose residues and forms elastic gels upon heating in aqueous suspension.It is produced by Agrobacterium biobar, a non pathogenic bacteria....

    , β-1,3-glucan
  • laminarin
    Laminarin
    The molecule laminarin is a storage glucan found in brown algae. It is used as a carbohydrate food reserve in the same way that chrysolaminarin is used by phytoplankton. It is created by photosynthesis and is made up of β-glucan with β-linkages. It is a linear polysaccharide, with a β:β ratio...

    , β-1,3- and β-1,6-glucan
  • chrysolaminarin
    Chrysolaminarin
    Chrysolaminarin is a linear polymer of β and β linked glucose units in a ratio of 11:1. It used to be known as leucosin. Chrysolaminarin is arguably one of the most common biopolymers in the world with cellulose being the other.-Function:...

    , β-1,3-glucan
  • lentinan
    Lentinan
    Lentinan is a beta-glucan with a glycosidic β-1,3:β-1,6 linkage. It is an anti-tumor polysaccharide from the shiitake mushroom. Lentinan is a polysaccharide that has a molecular weight of approximately 500,000 Da...

    , a strictly purified β-1,6:β-1,3-glucan from Lentinus edodes
  • lichenin
    Lichenin
    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 . It has been studied since about 1957...

    , β-1,3- and β-1,4-glucan
  • pleuran
    Pleuran
    Pleuran is an insoluble polysaccharide , isolated from Pleurotus ostreatus.Pleuran belongs to a group of glucose polymers commonly called beta-glucans demonstrating biological response modifier properties...

    , β-1,3- and β-1,6-glucan isolated from Pleurotus ostreatus
  • zymosan
    Zymosan
    Zymosan is a glucan with repeating glucose units connected by β-1,3-glycosidic linkages. It binds to TLR 2.Zymosan is prepared from yeast cell wall and consists of protein-carbohydrate complexes. It is used to induce experimental sterile inflammation...

    , β-1,3-glucan
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