Lichen polysaccharides

C,2H220,i 342.299 Constit. of the lichen polysaccharide in Cetraria islandica (iceland moss), Ramalina usnea and in the seed galacto-mannan of Cassia marylandica. 

Hirabayashi K, Iwata S, Ito M, Shigeta S, Narui T, Mori T, Shibata S (1989) Inhibitory effect of a lichen polysaccharide sulfate, GE-3-S, on the replication of human immunodeficiency virus (HIV) in vitro. Chem Pharm BuU 37 2410-2412... 

There has been considerable activity in this field since the last review (777) which has no doubt been stimulated by reports of the anti-tumour activity of many of these compounds 255,. 292, 294), although the mechanism of action is not known 330). The anti-tumour properties of some chemically modified lichen polysaccharides have also been studied (257). 

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. 

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

Watanabe M, Iwai K, Shibata S, Takahashi K, Narui T, Tashiro T (1986) Purification and Characterization of Mouse -Acid Glycoprotein and its Possible Role in the Antitumor Activity of some Lichen Polysaccharides. Chem Pharm Bull... 

A highly branched, acidic galactomannan was isolated from the oak lichen Evemia prunastri by extraction with cold alkali, followed by successive purification steps with barium hydroxide and Fehling solutions. The polysaccharide contained nonreducing end-units of galac-topyranose, mannopyranose, and glucopyranosyluronic acid, with 2-O-, 2,6-di-O-, 3-6-di-O-, and 2,3,6-tri-O-substituted mannopyranosyl... 

An article by Barreto-Bergter (Rio de Janeiro, Brazil) and Gorin (Saskatoon, Canada) likewise invokes strong emphasis on n.m.r. methods for structure determination, in this instance by use of carbon-13 techniques in delineating the structural chemistry of polysaccharides from fungi and lichens. 

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... 

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