Polysaccharides from Basidiocarps of the Polypore Fungus Ganoderma resinaceum: Isolation and Structure

Abstract

In this study, we focused on the isolation and structural characterization of polysaccharides from a basidiocarp of polypore fungus Ganoderma resinaceum. Polysaccharide fractions were obtained by successive extractions with cold water at room temperature (20 °C), hot water under reflux (100 °C), and a solution of 1 mol L−1 sodium hydroxide. The purity of all fractions was controlled mainly by Fourier transform infrared (FTIR) spectroscopy, and their composition and structure were characterized by organic elemental analysis; neutral sugar and methylation analyses by gas chromatography equipped with flame ionization detector (GC/FID) and mass spectrometry detector (GC/MS), respectively; and by correlation nuclear magnetic resonance (NMR) spectroscopy. The aqueous extracts contained two main polysaccharides identified as a branched O-2-β-d-mannosyl-(1→6)-α-d-galactan and a highly branched (1→3)(1→4)(1→6)-β-d-glucan. Mannogalactan predominated in the cold water extract, and β-d-glucan was the main product of the hot water extract. The hot water soluble fraction was further separated by preparative anion exchange chromatography into three sub-fractions; two of them were identified as branched β-d-glucans with a structure similar to the corresponding polysaccharide of the original fraction. The alkaline extract contained a linear (1→3)-α-d-glucan and a weakly branched (1→3)-β-d-glucan having terminal β-d-glucosyl residues attached to O-6 of the backbone. The insoluble part after all extractions was identified as a polysaccharide complex containing chitin and β-d-glucans.

Antioxidant Activities of Enriched Polysaccharide Fractions from Mycelia of Amauroderma subresinosum

“…4 The FTIR spectra of ASF-1, ASF-3, and ASF-7 showed peaks at 1077.1, 1051.7, and 1037.2 cm -1 , respectively which indicated the presence of a pyranose ring. 4,19,29 Additionally, a weak band of ASF-3 at 926.8 cm -1 associated with the β configurations of glycosidic linkages confirmed that ASF-3's monosaccharide was mainly glucose. Antioxidant assays DPPH (2,2-diphenyl-1-picrylhydrazyl) is a free radical capable of absorbing molecular hydrogen and antioxidants.…”

“…Subsequently, 96% ethanol in a ratio of 1:3 (v/v) was added to precipitate the polysaccharide. 19 The resulting residue was neutralized, washed, and dried using the same process.…”

“…They indicate that the typical major broad stretching peak is around 3400 cm -1 of hydroxyl groups. 4,19,29,30 Weak bands at 2923.7 and 2925.2 cm -1 can be represented by C-H stretching vibration. The bands at around 1653.1 cm -1 and 1345.2 cm -1 , were associated with the carboxyl group.…”

Structural features and in vitro antitumor activity of a water-extracted polysaccharide from Ganoderma applanatum

“…16 It was reported that two polysaccharides obtained from Ganoderma resinaceum by water extraction proved to be a branched O-2-β- d -mannosyl-(1→ 6)-α- d -galactan and a highly branched (1→ 3)(1→4)(1→6)-β- d -glucan, respectively. 17 It is well-known that the structure of polysaccharides is the basis of their biological activities, and they are closely related. Therefore, it is of great importance to further study the structure of Ganoderma applanatum polysaccharides and to investigate the relationship between their structure and activity.…”

Mid-Infrared Spectroscopic Study of Cultivating Medicinal Fungi Ganoderma: Composition, Development, and Strain Variability of Basidiocarps

“…The presence and distribution of target bioactive components in the fruiting bodies (basidiocarps) and other parts of this fungus may depend on the genetic background, cultivation conditions, and developmental stage. There are many studies of cell wall macromolecules and secondary metabolites in Ganoderma basidiocarps based on various analytical methods, including photometric assays [10], different techniques of mass spectrometry (MS) [11][12][13][14], one-and two-dimensional (1D, 2D) nuclear magnetic resonance (NMR) spectroscopy [15][16][17][18][19], gas chromatography with MS detection (GC-MS) [20], high-performance liquid chromatography (HPLC) [10,21], and HPLC with MS [21][22][23][24] or NMR [25] detection. These methods exhibit high accuracy, selectivity, and sensitivity to the structure of the analytes.…”