Yeast mannans

Mannans yeast mannan, Porphyra umbilicalis Tnafinan... 

Yeast cells contain, in addition to glucans, a highly branched mannan (yeast gum) which contains (i->-2), (1- 3), and (1 6) linkages, predominantly of the a-D-configuration. 

Many different types of carbohydrate-containing molecules are located on the surface of microbial cells. Some of these are components of die microbial cell wall and are limited to certain types of micro-organisms such as bacterial peptidoglycan, lipopolysaccharides, techoic adds and yeast mannans. Other polysaccharides are not... 

D. Page, D. Zanini, and R. Roy, Macromolecular recognition Effect of multivalency in the inhibition of binding of yeast mannan to concanavalin A and pea lectins by mannosylated dendrimers, Bioorg. Med. Chem., 4 (1996) 1949-1961. 

In this context, Lindhorst et al. proposed biological investigations of pentaerythri-tol-based mannoside clusters to test their capacity to block the binding of E. coli to yeast mannan in vitro.75 In all of the proposed structures, and according to a rational approach, pentaerythritol itself, as well as the included C3 spacers, were used as structural components for substituting the inner regions of the monosaccharide moieties (Scheme 4). The tetravalent cluster 27 has been efficiently synthesized according... 

Y. Li, X. Zhang, S. Chu, K. Yu, and H. Guan, Synthesis of cluster mannosides via a Ugi four-component reaction and their inhibition against the binding of yeast mannan to concanavalin A, Carbohydr. Res., 339 (2004) 873-879. 

Fungus A general term to denote a group of eukaryotic protist, including mushrooms, yeasts, rusts, molds, smuts, etc., which are characterized by the absence of a rigid cell wall composed of chitin, mannans, and sometimes cellulose. 

The majority of ascomycetous yeasts form cell-wall mannans or ga-lactomannans having main chains of (1— 6)-linked a-D-mannopyrano-syl residues, often substituted at 0-2 by a-linked glycosyl groups. The linkage types in the rest of the side chains vary widely, and can consist of 2-O-substituted a- or /3-D-mannopyranosyl residues, or 3-O-substi-... 

The structure of mannose-rich polysaccharide core in GL4 is close to that of yeast mannan (from Saccharomyces cerevisiae), which was inactive for IL-6 induction in a human peripheral whole-blood cells test system. This fact suggests that not the mannose moieties but other components, such as the lipophilic moiety and/or phosphates, are important for the activity. The lipophilic products in HF-hydrolysate of GL4 were then analyzed. In addition to peaks corresponding to the known fatty acids (C16 0, C18 1), two other unknown ion peaks at m/z 330 and 356 were found by FAB-MS (data not shown). 

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