Laminarin structure

Laminarin is the reserve carbohydrate of the sublitoral brown algae, especially Laminaria. There are two types of laminarin as regards solubility, the normal or water-insoluble laminarin (from L. cloustoni) and a soluble type (from L. digitata). These two kinds of laminarin differ only in solubility and are otherwise indistinguishable in composition and structure. They will not be further differentiated in this description. 

FIGURE 1 Potential hydrolysis rates of six structurally distinct polysaccharides in seawater (A) and surface sediments (B) from Skagerrak and Svalbard. Pull = pullulan, lam = laminarin, xyl = xylan, fu = fucoidan, ara = arabinogalactan, chon = chondroitin sulfate. Note the differences in scale on the y axes for sediments and for seawater. [Skagerrak data from Arnosti (2000).]... 

Studies on the Metabolism of the Chrysophyceae. Comparative Structural Investigations on Leucosin (Chrysolaminarin) Separated from Diatoms and Laminarin from the Brown Algae, Anne Beattie, E. L. Hirst, and Elizabeth Percival, Biochem. J., 79, 531 (1961). 

Among the polysaccharide elicitors are 3,6-3-glucans from Phytophthora megasperma (84, 85) and yeast cell walls (59) and the algal glucan, laminarin (84)., which have structures comparable to those described for the wilt-inducing P. cinnamomi,... 

Pang Z., Otaka K., Maoka X, Hidaka K., Ishijima S., Oda M., Ohnishi M., Structure of beta-glucan oligomer from laminarin and its effect on human monocytes to inhibit the proliferation of receptor binding in the CR3- human promonocytic cell line U937, Biosci. Biotechnol. Biochem., 69(3), 2005, 553-558. 

Polysaccharides of fresh water algae have been examined (139) and structural investigations of seaweed polysaccharides include fucoidin (68), laminarin (69,208), and a mannan (150). 

Other polysaccharides studied by ROA are lami-narin [16] and pullulan [18]. Laminarin, which is a P(l—>3) linked polymer of D-glucose, adopts a triple helix conformation. This is concluded by comparison with the ROA of the compound that corresponds to laminarin s dimer subunit, D-laminaribose. Pullulan is a linear polymer of D-glucose, consisting of D-mal-totriose units connected through a(1 6) glycosidic links. It adopts a random coil structure in aqueous solution, as can be deduced by the similarity of its ROA spectrum to that of D-maltotriose. 

The following study of laminarin polysaccharides illustrates the potential of MALDI-MS for rapidly and sensitively defining the degree of polymerization (d.p.) of carbohydrate polymers and for revealing structural modifications which result in altered molecular weight. 

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