RT Journal Article
ID 629d03f25ad7b95c
A1 Vinogradov, Evgeny
A1 Petersen, Bent O.
A1 Duus, Jens O.
T1 The Structure of the Polysaccharides Produced by Higher Basidiomyces <i>Tremella mesenterica</i> Ritz.: Fr. and <i>Inonotus levis</i> P. Karst
JF International Journal of Medicinal Mushrooms
JO IJM
YR 2005
FD 2005-09-02
VO 7
IS 3
SP 480
OP 481
AB Polysaccharides are the best known and most potent mushroom-derived substances, with various positive health effects including immunostimulation, lowering glucose level in blood, anticancer activity, and many others. Biologically active polysaccharides are widerspread among higher Basidiomycetes mushrooms, and most of them have unique structures in different species. There is still no clear correlation between biological activity and structural features of the polysaccharides. This situation results in part from poor knowledge of polysaccharide structures. Herein, we present the results from analyzing two polymers of <i>Tremella mesenterica</i> and <i>Inonotus levis</i>.<br>
<i>Tremella mesenterica</i> (Yellow Brain mushroom) possesses a wide spectrum of medicinal properties, including immunostimulating, protecting against radiation, antidiabetic, anti-inflammatory, hypocholesterolemic, hepatoprotective, and antiallergic effects. Glucuronoxylomannan (GXM), an extracellular polysaccharide produced by single cell culture of <i>T. mesenterica</i>, has a number of beneficial health effects. We developed a new strain of <i>T. mesenterica</i>, CBS 101939, which grows in submerged culture and offers superior yields of one-cell biomass rich in exocellular heteropolysaccharide GXM.<br>
NMR and chemical analysis showed that it has a defined structure of repeating unit, which is <i>O</i>-acetylated at several points, stoichometrically at <i>O</i>-6 of two mannose residues, and partially at GlcA residue, which is present in non-acetylated or acetylated at positions 3 or 4 forms (see F&#305;g. 1).<br>
These results differ from existing data on the structures of mushroom mannan-based polysaccharides, where mannan backbone was believed to be randomly glycosylated with xylan chains of different lengths.<br>
<i>Inonotus levis</i> polysaccharide had the structure shown in Figure 2, where terminal glucuronic acid residue is present in about half of the molecules, thus making some of the chains acidic and others neutral. We believe that these short polymeric chains were originally attached to some protein via serine or threonine residue and were cleaved off due to alkaline conditions of extraction. Another polymer, co-extracted with this galactan, was a branched, phosphorylated mannan with a structure similar to that of the mannan from yeast <i>Saccharomyces cerevisiae</i> yeast.
PB Begell House
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