Lichenan polysaccharide

Investigation into the formation of carboxymethyl ethers of polysaccharides has continued, on account of the great utility of these derivatives as ion-exchange materials and polyelectrolytes. As expected, a whole series of polysaccharide derivatives of different degrees of substitution can be prepared by variation of the reaction conditions and molar proportions of monochloroacetic acid. " Published reports include the preparation of various carboxymethyl ethers of starches, amyloses, lichenan, pachymans, and chitin and introduction of the carboxymethyl group into polysaccharide derivatives constitutes a useful way of raising their solubility in water. By combining the introduction of alkyl and carboxy-... 

Lichen consists of mainly of the polysaccharide lichenan, with some for 62% of the total carbohydrate content. Lichenan is a linear polysaccharide from /3-D-glucopyranose that is linked by both 1,3 and 1,4 linkages (37). 

Baron M, lacomini M, Fanta ES, Gorin PA (1991) Galactomannan, lichenan and, isolichenan from the polysaccharide-rich lichen Neuropogon aurantiaco-ater. Phytochemistry 30 3125-3126... 

Homoglycans, linear Glucans cellulose, amylose, chitin, laminaran, lichenan, crown gall polysaccharide, pustulan... 

The lichen Cetraria islandica (Iceland moss) contains the structural polysaccharide lichenan, which is insoluble in cold water, and the related water-soluble polysaccharide isolichenan. Periodate oxidation and methylation studies indicate that lichenan is a linear glucan containing both / -D-(i - 3) and /S-D-(i 4) linkages in a ratio approximately 2 5, while isolichenan is similarly constituted but with the linkages in the ratio 3 2. Isolichenan has a TTP of 42-44. 

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