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Material type:	Polymer
Material group:	Homo polysaccharide, both linear and branched
Monomer(s):	D-glucose
Links:	beta-(1-3) beta-(1-4) beta-(1-6)
Origin of the polymer:	Natural

Structure

Two types:
Type I: (→3)-ß-D-glucose(1→) and (→4)-ß-D-glucose(1→). Linear, 1,3 and 1,4 bond ratio: 1:2 [2].
Type II: (→3)-ß-D-glucose(1→) (major) and (→6)-ß-D-glucose(1→) (minor). Branched, variable proportions. Some yeasts have highly regular structures others are of uncertain destribution [1].

Chemical properties

Poorly soluble in cold water [2].

Preferred substitution at position 6. Derivatives with branching at position 6 usually adopts a single helix formation at neutral pH [3].

Biological properties

Antitumor activity. Decreasing activity with increasing degree of 1,4-linking. Sulfoalkylation removes antitumor activity [3].

Physical properties

Appearance
	Physical state @ 20°C:	Solid

Bulk properties
	Molecular weight (g/mol):	5400-7200 [2].
	Degree of polymerization:	30-40 [2]

Occurence, isolation & synthesis

Occurence
Type I: Various lichens, cereals (especially oats and barley), and grasses. Occurs as cell-wall component in monocots increasingly recognized.
Type II: Widespread in yeast [1].

References

1: H.F.Mark, N.M.Bikales, C.G.Overberger, G.Menges, J.I.Kroschwitz. Encyclopedia of Polymer Science and Engineering 2.ed.
(1988) John Wiley & Sons

2: P.Krämer, U.Wincierz, G.Grubler, J.Tschakert, W.Voelter, H.Mayer. Rational Approach to Fractionation, Isolation, and Characterization of Polysaccharides from the Lichen Cetraria islandica
Arzneimittelforschung (1995) 45 726-31

3: S.Demleitner, J.Kraus, G.Franz. Synthesis and Antitumour Activity of Sulfoalkyl Derivatives of Curdlan and Lichenan
Carbohydr. Res. (1992) 226 247-52

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© Michael Pilgaard
Created: March 6, 2008