Structural characterization and determination of biological activities for different polysaccharides extracted from...

Chemical composition and structural characterization of polysaccharides of Fomes fomentarius (FF), Fuscoporia torulosa, Ganoderma adspersum, Ganoderma applanatum (GAP), Ganoderma lucidum, Phellinus igniarius, Pleurotus ostreatus (PO), and Porodaedalea pini (PP) tree mushrooms with antioxidant and anticholinesterase activities were determined in this research. Total carbohydrate contents of the polysaccharides were ranged between 65.06 ± 6.76 and 88.27 ± 5.15 µg/mg and total protein contents were ranged between 3.18 ± 0.72 and 6.56 ± 1.25 µg/mg. Galactose, glucose, and mannose were identified as major monosaccharides in all polysaccharides using gas chromatography-mass spectrometry. FT-IR analysis showed the characteristic peaks of the polysaccharides and high performance liquid chromatography-diode array detection was used to determine the molecular weight of the polysaccharides. In β-carotene-linoleic acid assay FF (IC₅₀ : 2.55 ± 0.40 µg/ml) displayed the highest antioxidant activity, whereas GAP indicated the highest antioxidant activity in cupric reducing antioxidant capacity (A_0.50 :59.90 ± 0.53 μg/ml), ABTS^•+ (IC₅₀ : 16.62 ± 0.31 μg/ml), and DPPH^• (IC₅₀ : 45.58 ± 0.21 μg/ml) assays. In cholinesterase inhibitory activity test, PO (56.31±0.0.74%) showed significant inhibitory activity against butyrylcholinesterase enzyme. PRACTICAL APPLICATIONS: Polysaccharides from mushrooms are the major class of bioactive compounds with various biological activities. Several studies were performed on the biological activity of the polysaccharide extracts from different mushrooms. However, to our knowledge, this is the first report on the chemical composition, structural characterization, antioxidant, and anticholinesterase activities of extracted polysaccharides from studied mushrooms in detail. This investigation shows that polysaccharide extracts obtained from tree mushrooms show a significant bioactivity and these polysaccharides might be used as bioactive natural sources in the pharmaceutical, food, and cosmetic industries.