Unusual partially 3-O-methylated α-galactan from mushrooms of the genus Pleurotus

Indistinguishable partially 3-O-methylated galactans were isolated from the edible basidiomycetes Pleurotus eryngii and Pleurotus ostreatoroseus. They were linear, partially 3-O-methylated, (1 → 6)-linked α-galactans containing Gal and 3-Me-Gal, in a 3:1 molar ratio. The presence of the structure now described is the first in fruit bodies of mushrooms.