Polysaccharides of lichens

Nishikawa Y, Tanaka M, Shibata S, Fukuoka F (1970) Polysaccharides of lichens and fungi. IV. Antitumor active 0-acetylated pustulan-type glucans from the lichens of Umbilicaria species. Chem Pharm Bull 18 1431-1434... 

Seshadri TR, Venkatasubramanian GB (1959) A new synthesis of diploschistesic acid. J Chem Soc 1658-1659 Shibamoto T, Wei C-I (1984) Mutagenicity of lichen constituents. Environmental Mutagenesis 6 757-762 Shibata S (1973) Polysaccharides of lichens. J Natl Sci Counc Sri Lanka 1 183-188... 

Hauan, E., and O. Kj0lberg Studies on the Polysaccharides of Lichens. I. The Structure of a Water-soluble Polysaccharide in Stereocaulon paschale (L.) Fr. Acta Chem. Scand. 25, 2622 (1971). 

Shibata, S. Polysaccharides of Lichens. J. Nat. Res. Council Sri Lanka 1, 183 (1973). Shibata, S., Y. Nishikawa, T. Takeda, and M. Tanaka Polysaccharides in Lichens and Fungi. I. Antitumour Active Polysaccharides of Gyrophora esculenta Miyoshi and Lasallia papulosa (Ach.) Llano. Chem. Pharm. Bull. (Japan) 16, 2362 (1968). 

Takahashi, K., T. Takeda, and S. Shibata Polysaccharides of Lichen Symbionts. Chem. Pharm. Bull. (Japan) 27, 238 (1979). 

Kjolberg O, Kvernheim AL (1984) Studies on the Polysaccharides of Lichens. II. The Structure of Water-soluble Polysaccharides in Umbilkaria pustulata (L.) Hoffm. and Umbilkaria spodochroa (Ach.) Hoffm. Acta Chem Scand B38 735... 

Takahashi K, Kon T, Yokota 1, Shibata S (1981) Chemotaxonomic Studies on the Polysaccharides of Lichens. Polysaccharides of Stereocaulaceous Lichens. Carbohydrate Res 89 166... 

The Alkali-soluble Polysaccharides of the Lichen Cladonia alpestris (Reindeer Moss), G. O. Aspinall, E. L. Hirst, and (Mrs.) Margaret Warburton, J. Chem. Soc., 651... 

Acid-base titration studies measuring the concentrations and acid dissociation properties of functional groups on lichen cell walls, extracellular polysaccharides and lichen acids. 

Percival also applied himself to the study of the polysaccharides from lichens, as, for example, the complex product of alkaline extraction of Iceland moss (Cetraria islandica). As a result of this work, he concluded that the polysaccharide consists of S-D-glucose residues united by various linkages 1,2, 1,3, 1,4, and 1,6, and includes also terminal D-galacto- and D-gluco-pyranose end groups. It was not possible to decide whether these linkages all occur in one polysaccharide. ... 

Gorin PAJ, Barreto-Bergter E (1983) The chemistry of polysaccharides of fungi and lichens. In Aspinall GP (ed) The polysaccharides, vol 2. Academic Press, New York, chap 6... 

It contains more than 50% of a mucilage which is soluble in warm water and consists of two polysaccharides, lichenin, which is built of 60-200 glucose molecules, and isolichenin, which is soluble in cold water and built of about 40 glucose molecules. The bitter taste is due to the occmrence of lichen acids. 

Nishikawa Y, Takeda T, Shibata S, Fukuoka F (1969) Polysaccharides in lichens and fungi. III. Further investigation on the structures and the antitumor activity of the polysaccharides from Gyrophora esculenta Miyoshi and Lasallia pustulata Llano. Chem Pharm Bull 17 1910-1916... 

Yokota I, Shibata S (1978) A polysaccharide of the lichen, Stereocaulon japonicum. Chem Pharm Bull 26 2668-2670... 

Fujikawa F, Hirai K, Hirayama T et al (1972) Influence of cytochalasin B on hyphal morphogenesis of Aspergillus nidulans. Yakugaku Zasshi 92 823-827 Fukuoka F, Nakanishi M, Shibata S et al (1968) Polysaccharides in lichens and fungi. II. Antitumor activities on sarcoma-180 of the polysaccharide preparations from Gyrophora esculenta Miyoshi, Cetraria islandica (L.) Ach. var. orientalis Asahina, and some other lichens. Gann 59 421-432... 

Nishikawa Y, Ohno H (1981) Studies on the water-soluble constituents of lichens. IV. Effect of antitumor lichen-glucans and related derivatives on the phagocytic activity of the reticuloendothelial system in mice. Chem Pharm Bull (Tokyo) 29 3407-3410 Nishikawa Y, Takeda T, Shibata S et al (1969) Polysaccharides in lichens and fungi. 3. Further investigation on the structures and the antitumor activity of the polysaccharides from Gyrophora esculenta Miyoshi and Lasallia papulosa Llano. Chem Pharm Bull (Tokyo) 17 1910-1916... 

Takahashi, Takeda, and Shibata (322) have made a comparative study of the water-soluble polysaccharides isolated from laboratory cultures of lichen phycobionts and mycobionts. Those of the mycobionts were closely related to those of the parent lichen so that it is likely that the water-soluble lichen polysaccharides are produced by the mycobiont like the lichen metabolites of lower molecular weight. 

Neither Usno nor other lichen medicines have, however, gained a permanent position in the medical praxis the fight for a place in the sun among antibiotics is too hard. Since the last decade the medicinal research of lichens has turned to new directions the untiring Japanese group Nakazava, Komatsu, Hamada, Fujikawa, Hirai, Shibata et al. has studied the antitumor activity of lichens intensively since 1962. This activity obviously depends on the polysaccharide component in lichens, as found in Umbilicaria, Lasallia, Cetraria, Cladonia, Parmelia, and Usnea, and from psoromic acid. 

A solution of 0.2-0.5 gm iodine in 100 ml aqueous 0.5% potassium iodide is often used as a reagent for certain polysaccharides in lichens (the I test). The reagent is susceptible to air oxidation and should be renewed when the brownish color fades. Isolichenin, but not lichenin, will give a blue color. The chemistry of the color reaction is probably the same as that for the well-known iodine test for starch. The reaction is reversible (the color disappears upon dilution with water). 

Axenic cultures of lichen thalli are not possible because of the bacterial flora on the thalli. Bacterial cells are found lodged in chinks and cracks of the lichen thalli and embedded within the extracellular polysaccharide material found throughout the thalli (Jacobs and Ahmadjian, 1971). Attempts to sterilize thalli with plasmolyzing agents or radiation have not been successful. The only possible way to achieve lichen thalli that are free from contaminants is to begin with the separate symbionts and recombine them under sterile conditions. Such a possibility now exists with pusillum (Ahmadjian and Heikkila, 1970). 

The Polysaccharides, Vol. 2 (G. O. Aspinall, ed.) Academic, New York (1983). Chap. 1, Classification of polysaccharides Chap. 2, Cellulose Chap. 3, Other plant polysaccharides Chap. 4, Algal polysaccharides Chap. 5, Bacterial polysaccharides Chap. 6, The chemistry of polysaccharides of fimgi and lichens. 

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