The Structure of the Polysaccharides Produced by Higher Basidiomyces Tremella mesenterica Ritz.: Fr. and Inonotus levis P. Karst.
Bibliographic record
Abstract
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 Tremella mesenterica and Inonotus levis. Tremella mesenterica (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 T. mesenterica, has a number of beneficial health effects. We developed a new strain of T. mesenterica, CBS 101939, which grows in submerged culture and offers superior yields of one-cell biomass rich in exocellular heteropolysaccharide GXM. NMR and chemical analysis showed that it has a defined structure of repeating unit, which is O-acetylated at several points, stoichometrically at O-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 Fıg. 1). 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. Inonotus levis 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 Saccharomyces cerevisiae yeast.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".