Structure of a novel α-glucan substitute with the rare 6-deoxy-D-altrose from Lactarius lividatus (mushroom).

A novel alpha-glucan substituted rare 6-deoxy-D-altropyranose was isolated from edible fruiting bodies of a mushroom (Lactarius lividatus) grown in Okinawa, japan. The polysaccharide consists of D-glucose, D-galactose and 6-deoxy-D-altrose in a molar ratio of 3.0:1.0:1.0. The specific rotation [alpha](589) was estimated as +64.3 degrees (0.2% in water) at 25 degrees C. Based on results of IR, NMR (H-1, C-13, 2D-COSY, 2D-HMQC, 2D-ROESY and 2D-HMBC), and methylation analyses, the structure of the polysaccharide was determined as [GRAPHICS] This work is the first demonstration of rare 6-deoxy-D-altropyranose moiety on polysaccharides. (C) 2012 Elsevier Ltd. All rights reserved.