Lichens glucans

Pustulan (a glucan from the lichen Umbilicaria pustulata)... 

Antitumor Activity of Lichen Glucans Against Subcutaneously Implanted Sarcoma 180 in Mice"... 

Table I describes the glucans we examined, including their source, molecular weight, and solubility in H20 The samples were used without further purification, with the exception of pustulan i9)y which was purchased as an unbleached and partially acetylated extract of the lichen P. papullosa. Deacetylation (saponification) of native pustulan was accomplished by dissolving the material in 1% aqueous NaOH at 90 C and allowing the solution to stand at 50-60 C overnight. Following neutralization with HCl, the brown colored solution was bleached with NaClO yielding a faintly yellow solution. The bleached pustulan was precipitated with 95% ethanol and collected by vacuum filtration. After several washings with alcohol, the precipitate was redissolved in hot water, allowed to cool, and dialyzed using an Amicon ultrafiltration membrane apparatus. Solutions were then freeze dried.

A similar linear (1 - 6)-glucan was isol. from the lichen Gyrophora esculenta. 

The first polysaccharides found to stimulate the reticuloendothelial system were isolated from fungi, algae and lichens and have been described in several review articles [1, 52-54]. As shown in Table 4, the glucans with P-1,3-linkages in the back bone and further P-1,6-branching points are the dominating types. 

Activity Against Human Immunodeficiency Virus (HIV). A sulfate (GE-3-S) prepared by chlorosulfonic acid treatment GE-3, a partially acetylated P(1 - 6)glucan from the lichen Umbilicaria esculenta (Miyoshi) Mink., inhibited the cytopathic effect of HIV in vitro (Hirabayashi et al. 1989). 

Nishikawa Y, Ohno H (1981) Studies on the water-soluble constituents of lichens. IV. Effect of antitumour lichen-glucans and related derivatives on the phagocytic activity of the reticuloendothelial system in mice. Chem Pharm Bull 29 3407-3410... 

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... 

Nishikawa Y, Yoshimoto K, Horiuchi R (nee Murakami), Michishita K, Okabe M, Fukuoka F (1979) Studies on the water-soluble constituents of lichens. III. Changes in antitumor effect caused by modifications of pustulan- and lichenan-type glucans. Chem Pharm Bull 27 2065-2072... 

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... 

The hyphal cell walls of three mycobionts isolated from the lichens Xanthoria parientina, Tornabenia intricata, and Sarcogyne sp. are composed of chitin and glucan. Fluorescein-labelled lectins were used to locate the polysaccharides in the cell wall. 

HRANiSAVLJEVif -JAKOVLJEVi( , M., J. Miljkovic-Stojanovk , R. DiMiTRiJEVif , and V. M. M1COV16 Water- and Alkali-Soluble Glucans from Oak Lichen. Carbohydrate Res. 39,115 (1975). 

Nishikawa, Y., K. Yoshimoto, R. Horiuchi (nee Murakami), K. Michishita, M. Okabe, and F. Fukuoka Change in Antitumor Effect Caused by Modifications of Pustulan Type and Lichenan Type Glucans. Chem. Pharm. Bull. (Japan) 27,1065 (1979). Nolan, T. J., J. Algar, E. P. McCann, W. A. Manahan, and N. Nolan The Chemical Constituents of Lichens Found in Ireland. Buellia canescens. Part 3. The Constitution of Diploicin. Sci. Proc. Roy. Dublin Soc. 24, 319 (1948). 

Takeda, T., Y. Nishikawa, and S. Shibata A New a-Glucan from the Lichen Parmelia caperata (L.) Ach. Chem. Pharm. Bull. (Japan) 18, 1074 (1970). 

The cell walls of the hyphae consist mainly of the polysaccharides, lichenin and isolichenin, and, to a lesser extent, pustulan and other glucans, some of which occur solely in lichens. The widespread lichenin is a linear /5-D-glucopyranosyl polymer of molecular weight 20,000-40,000 lying between those of starch and cellulose (Peat et aL, 1961). 

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