Influence of extraction parameters on physico-chemical characters and antioxidant activity of water soluble polysaccharides from Macrocybe gigantea (Massee) Pegler & Lodge

Abstract

Polysaccharides from mushrooms are potentially active pharmaceutical ingredients and their action is dependent upon conformation, composition, size etc. In this context, three water soluble crude polysaccharide rich fractions viz. hot water extracted polysaccharide (HWP), cold alkaline extracted polysaccharide (CAP) and hot alkaline extracted polysaccharide (HAP) have been isolated using varying extraction parameters from Macrocybe gigantea, a well-known edible mushroom collected from Gangetic plain of West Bengal and authenticated by DNA barcoding of nrDNA ITS region. Physico-chemical investigation revealed that the fractions were mainly composed of β-configuration in pyranose form of sugars conjugated with small amount of protein. Further analysis presented that polysaccharides were composed of same monosaccharide even in similar order of ratio (D-glucose > D-galactose > D-mannose > D-xylose). However, Dglucose as well as β-glucan were found to be in the highest amount in CAP. The helical structure was determined by Congo red assay which indicated that polysaccharides were in aggregate forms except HWP which consisted of tertiary structure. These diverse structural features may have imparted effect on free radical scavenging activity of polysaccharides where HWP was the most active in all assays. HWP was proved to be a good scavenger of free radicals, strong chelator of ferrous ion and had high reducing power. Thus it can be inferred that HWP may foster further studies for searching active compound which might be used as ingredients of functional foods, nutraceuticals and pharmaceuticals. Moreover, to the best of our knowledge this is the first report on chemical composition and antioxidant activity of different crude polysaccharides from M. gigantea.

Crude polysaccharide from a wild mushroom enhances immune response in murine macrophage cells by TLR/NF-κB pathway

“…Firstly, chemical parameters of MLHWP were analysed spectroscopically which can be ranked in the following order: carbohydrates > protein (Table ). Carbohydrates, especially β‐glucan constituted the major proportion of this crude polysaccharide and its relative composition of is very much allied with previous published research findings on Russula alatoreticula , Macrocybe gigantea , Lentinus squarrosulus , Ganoderma applanatum and others.…”

“…The band at 883.6 cm À1 confined that the polysaccharide possessed b glycosidic linkages between sugar residues. [26] Altogether, the spectrum demonstrated that MLHWP was a b-glucan with pyranose sugar residues linked through b glycosidic bonds although little amount of phenols and proteins were co-extracted with polysaccharide.…”

“…The hydrolysate was then dissolved in 50% ethanol and after centrifugation, to remove unhydrolysed polysaccharide, the supernatant was subjected for HPTLC and GC‐MS analysis. For HPTLC, eight monosaccharide standards were used and GC‐MS chromatogram was analysed using programmed database (NIST) of the system …”

“…For HPTLC, eight monosaccharide standards were used and GC-MS chromatogram was analysed using programmed database (NIST) of the system. [26] Determination of immune-boosting effect of MLHWP…”

Influence of Solid Media on Growth of Mycelia and Antibacterial Activity of Wild Macrofungi, Macrocybe Gigantea

“…The giant sized macrofungi Macrocybe gigantea (Massee) Pegler & Lodge 6 was collected from Agumbe rainforest. More fruiting bodies of M. gigantea are found during continuous rain with an average relative humidity of 70% and temperature range between 25 -28 º C. M. gigantea is a common edible mushroom which grows in regions of high temperature and humidity and distributes in subtropical rain forests in Africa and Asia 7. In India, this macrofungus has been documented from three states, viz., Kerala, Karnataka and West Bengal 8,9,10 . This Basidiomycetes fungus belongs to the family Catathelasmataceae.…”