Glucans from Lichens

Parmelia caperata (L.) Ach. provided a cold-water-insoluble a-D-glucopyranan having (1— 3)- and (1— 4)-linked residues in equimolar proportions. As there were no successive, (1— 3) and (1— 4) linkages, the glucan is structurally similar to nigeran (repeating unit 5).75 

Mannans of Hansenula capsulata Y-1842 and H. holstii Y-2448 differ structurally from the phosphonomannan components.83 The man-nan of H. capsulata is probably a cell-wall component, and it has the linear, repeating-structure 6. Other Pichia and Hansenula mannans have predominantly linear structures.84 The 13C-n.m.r. spectrum of 6 (see Fig. 2) is distinguishable from that of the branched-chain man-nan85 from Saccharomyces rouxii (repeating unit 7.) 

The cell-wall mannan of Candida sp. P.R.L. 1520 is almost linear, with a block type of structure involving successive (1— 3)- and (1— 6)-linked a-D-mannopyranosyl units.86 

The mannan and glycoprotein from the cell wall of Saccharomyces cerevisiae have been extensively investigated by Ballou and coworkers.89 The mannan contains a (1— 6)-linked, a-D-mannopyranosyl 

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

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, 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... 

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). 

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). 

Stipanovic AJ, Giammatteo PJ, Robie SB (1986) Polysaccharides from Lichens. C-NMR Studies on (1 - 6)-P-o-Glucan (Pustulan). Polymer Science Technol 33 41... 

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. 

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. 

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