2Gause Institute of New Antibiotics, Russian Academy of Medical Sciences, B. Pirogovskaya ul. 11, 119992 Moscow, Russia
* To whom correspondence should be addressed.
Received March 7, 2008
Two polysaccharides were isolated from submergedly cultured mycelium of the basidiomycete Ganoderma lucidum by extraction with alkali followed by fractionation with Fehling reagent. The polysaccharides were shown to be a linear (1→3)-α-D-glucan and a highly branched xylomannan containing a backbone built up of (1→3)-linked α-D-mannopyranose residues, the majority of which are substituted at O-4 by single β-D-xylopyranose residues or by disaccharide fragments β-D-Manp-(1→3)-β-D-Xylp-(1→. Polysaccharide structures were elucidated by NMR spectroscopy in combination with methylation analysis and periodate oxidation. An interesting feature of the xylomannan is the simultaneous presence of α-D-mannopyranose and β-D-mannopyranose residues, the first forming the backbone, and the second being the non-reducing terminal units of disaccharide side chains.
KEY WORDS: Basidiomycetes, white rot fungi, Ganoderma lucidum, polysaccharides, (→3)-α-D-glucan, branched xylomannan, NMR spectroscopy