Structure Identification of Two Polysaccharides from with Antioxidant Activity.

Mushrooms of the genus exhibit a variety of biological activities. Two polysaccharides (MSP1-1, 389.0 kDa; MSP1-2, 23.4 kDa) were isolated from by subcritical water extraction and column chromatography fractionation. Methylation and nuclear magnetic resonance analysis determined MSP1-1 as a glucan with a backbone of (1→4)-α-D-glucan branched at O-6, and MSP1-2 as a galactomannan with coextracted α-glucan. Light scattering analysis and transmission electron microscopy revealed that MSP1-1 possessed a random coil chain and that MSP1-2 had a network chain. This is the first time that a network structure has been observed in a polysaccharide from . Despite the differences in their chemical structures and conformations, both MSP1-1 and MSP1-2 possessed good thermal stability and showed antioxidant activity. This study provides fundamental data on the structure-activity relationships of polysaccharides.