The mushrooms of the genus Ganoderma are popular for their important biological activities, such as antioxidation, anti-inflammatory, antitumour, antiulcer, antiviral, etc. Ganoderma capense is one of the important members of this fungus family, which possesses potential pharmacological properties. There is a dearth of information on the biochemical constituents of G. capense. The present study aimed to isolate, purify, and characterize the structure of the polysaccharide obtained from the mycelia of G. capense. A novel water-soluble polysaccharide (GCP50-1) was obtained from the dried powder of submerged fermentation mycelia of G. capense by extraction with hot water and further successive purification through diethylaminoethyl (DEAE) Sepharose CL-6B and Sephadex G-75 column chromatography. The average molecular weight of the polymer was 1.5 × 10(4)Da determined by a high performance gel permeation chromatography (HPGPC), and its specific optical rotation was be [α]₂₅(D)=+170°. The structural feature of GCP50-1 was investigated by monosaccharide analysis, partial acid hydrolysis, methylation analysis, periodic acid oxidation, gas chromatography-mass spectrometry (GC-MS), Fourier transform-infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy. The results obtained from the analyses indicated that GCP50-1 was an α-D-glucan with the main backbone chain of (1→4)-α-D-glucopyranosyl residue interspersed with (1→4, 6)-α-D-glucopyranosyl residue and the side chain attached to the O-6 position with (1→)-α-D-glucopyranosyl residue. This was the first report on the detailed structure elucidation of this novel polysaccharide from G. capense mycelia powder.

structure, polysaccharide, α-D-glucan, Edible mushroom, Ganoderma capense (Lloyd) Teng

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
4	aDGlcp	99.6	71.7	73.3	76.7	71.5	60.7
4,4	aDGlcp	99.6	71.7	73.3	76.7	71.5	60.7
6	aDGlcp	?	72.4	74.0	71.3	71.1	60.4
	aDGlcp	95.7	72.8	74.5	76.8	76.2	69.3

The spectrum also has 1 signal at unknown position (not plotted).

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@@H]1[C@@H](CO)O[C@H](O[C@@H]2[C@@H](CO)O[C@H](O[C@@H]3[C@@H](CO)O[C@H](O[C@@H]4[C@@H](CO)O[C@H](O[C@@H]5[C@@H](CO)O[C@H](O[C@@H]6[C@@H](CO)O[C@H](O[C@@H]7[C@@H](CO[C@H]8O[C@H](CO)[C@@H](O)[C@H](O)[C@H]8O)O[C@H](*)[C@H](O)[C@H]7O)[C@H](O)[C@H]6O)[C@H](O)[C@H]5O)[C@H](O)[C@H]4O)[C@H](O)[C@H]3O)[C@H](O)[C@H]2O)[C@H](O)[C@H]1O

1297.128 g/mol (C₄₈H₈₀R₂O₄₀, R = next and previous repeats, not counted in mol weight)

We find that the N-linked Man8GlcNAc2- core oligosaccharide of Saccharomyces cerevisiae mnn mutant mannoproteins is enlarged by the addition of the outer chain to the α 1----3-linked mannose in the side chain that is attached to the β 1----4-linked mannose rather than by addition to the terminal α 1----6-linked mannose. This conclusion is derived from structural studies on a phosphorylated oligosaccharide fraction and from mass spectral fragment analysis of neutral core oligosaccharides.

There are 2 chemically distinct structures. Please, select:
aDManp(1-2)aDManp(1-2)aDManp(1-3)[aDManp(1-3)[aDManp(1-2)[aDManp(1-6)]aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]?DGlcpN aDManp(1-2)aDManp(1-2)aDManp(1-3)[aDManp(1-3)[aDManp(1-2)[aDManp(1-6)]aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]xDGlcaN

SVGMWSMILES3D molIonize

 

CC(=O)N[C@H]1C(O)O[C@H](CO)[C@@H](O[C@@H]2O[C@H](CO[C@H]3O[C@H](CO[C@H]4O[C@H](CO[C@H]5O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]5O)[C@@H](O)[C@H](O)[C@@H]4O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H](O)[C@H](O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H]3O)[C@@H](O)[C@H](O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O)[C@@H]2O)[C@@H]1O

1680.478 g/mol (C₆₂H₁₀₅NO₅₁)

We find that the N-linked Man8GlcNAc2- core oligosaccharide of Saccharomyces cerevisiae mnn mutant mannoproteins is enlarged by the addition of the outer chain to the α 1----3-linked mannose in the side chain that is attached to the β 1----4-linked mannose rather than by addition to the terminal α 1----6-linked mannose. This conclusion is derived from structural studies on a phosphorylated oligosaccharide fraction and from mass spectral fragment analysis of neutral core oligosaccharides.

There are 2 chemically distinct structures. Please, select:
aDManp(1-2)aDManp(1-2)[aDManp(1-6)]aDManp(1-3)[aDManp(1-3)[aDManp(1-2)aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]?DGlcpN aDManp(1-2)aDManp(1-2)[aDManp(1-6)]aDManp(1-3)[aDManp(1-3)[aDManp(1-2)aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]xDGlcaN

SVGMWSMILES3D molIonize

 

CC(=O)N[C@H]1C(O)O[C@H](CO)[C@@H](O[C@@H]2O[C@H](CO[C@H]3O[C@H](CO[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H](O)[C@H](O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H]3O)[C@@H](O)[C@H](O[C@H]3O[C@H](CO[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O)[C@@H]2O)[C@@H]1O

1680.478 g/mol (C₆₂H₁₀₅NO₅₁)

We find that the N-linked Man8GlcNAc2- core oligosaccharide of Saccharomyces cerevisiae mnn mutant mannoproteins is enlarged by the addition of the outer chain to the α 1----3-linked mannose in the side chain that is attached to the β 1----4-linked mannose rather than by addition to the terminal α 1----6-linked mannose. This conclusion is derived from structural studies on a phosphorylated oligosaccharide fraction and from mass spectral fragment analysis of neutral core oligosaccharides.

There are 2 chemically distinct structures. Please, select:
aDManp(1-2)aDManp(1-2)[aDManp(1-2)aDManp(1-6)]aDManp(1-3)[aDManp(1-3)[aDManp(1-2)aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]?DGlcpN aDManp(1-2)aDManp(1-2)[aDManp(1-2)aDManp(1-6)]aDManp(1-3)[aDManp(1-3)[aDManp(1-2)aDManp(1-6)]aDManp(1-6)]bDManp(1-4)[Ac(1-2)]xDGlcaN

SVGMWSMILES3D molIonize

 

CC(=O)N[C@H]1C(O)O[C@H](CO)[C@@H](O[C@@H]2O[C@H](CO[C@H]3O[C@H](CO[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H](O)[C@H](O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H]3O)[C@@H](O)[C@H](O[C@H]3O[C@H](CO[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]4O)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]3O)[C@@H]2O)[C@@H]1O

1842.619 g/mol (C₆₈H₁₁₅NO₅₆)