Structural studies of Paecilomyces tenuipes Samson polysaccharide-part-2

A water-soluble polysaccharide-part-2 separated from Paecilomyces tenuipes Samson was determined to be homogeneous by gel permeation chromatography (GPC). HPLC showed a monosaccharide containing d-glucose, d-galactose, and d-mannose at a ratio of about 2:1:1. The number-average molecular weight was estimated to be 1.02 × 104. The specific rotation was determined to be [α]D20=+54°. The GC–MS analysis of hydrolysates obtained from acid-catalyzed hydrolysis of both Paecilomyces tenuipes Samson-part-2 and its methylated product showed that it has a β-(1 → 6)-d-glucose main chain with β-(1 → 6)-d-mannose and β-(2 → 6)-d-galactose side chains. The results obtained from IR, 1H NMR, and 13C NMR analyses confirmed the proposed structure.