ISOLATION, PURIFICATION AND STRUCTURAL CHARACTERIZATION OF A NOVEL WATER-SOLUBLE GLUCAN FROM THE FRUITING BODIES OF PHELLINUS BAUMII PILÁT

Abstract

Phellinus baumii Pilat is a well-known oriental medicinal fungus that has various biological activities such as antitumor, antimutagenicity and immunomodulating activity. A new β-D-glucan easily soluble in water, was obtained from the fruiting bodies of P. baumii Pilat (PBF-I) using hot water extraction, ethanol precipitation and anion-exchange and gel-filtration chromatography. Its chemical structure was investigated by compositional analysis, methylation analysis, Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR) and 13C NMR spectroscopy analysis. Based on the data obtained, PBF-I was mainly composed of glucose, with an average molecular weight of about 1,920 kDa. It was shown to have a backbone of β-(16)-linked D-glucopyranosyl residues, with a minor of β-(13)-linked D-glucopyranosyl and terminal β-D-glucopyranosyl residues. PRACTICAL APPLICATION Recently, medicinal mushroom polysaccharides have received special attention because they have potent biological and pharmacological activities including antitumor, immunomodulating, antiviral, hypoglycemic, hepatoprotective and antioxidant activities. Phellinus baumii Pilat, a well-known fungus belonging to the Hymenochaetaceae basidiomycetes, is a mushroom used as folk medicine for a variety of human diseases, such as diabetes, cancer and toxification in Asia. This paper describes the structure of polysaccharides isolated from P. baumii Pilat using methylation analysis, nuclear magnetic resonance spectroscopy, gel and ion-exchange chromatography as a contribution to better identify correlations between structure and functionality. It should help in understanding the antitumor mechanisms of Phellinus mushroom polysaccharides. The polysaccharide would certainly be significant for its utilization both in pharmaceutical and food industries.