Termitomycesphins G and H, Additional Cerebrosides from the Edible Chinese Mushroom Termitomyces albuminosus

Two new cerebrosides, termitomycesphins G and FI, were isolated from the edible Chinese mushroom, Termitomyces albuminosus (Berk.) Herm., and exhibited neuritogenic activity against PC12 cells. Their structures and absolute stereochemistry were elucidated by spectroscopic methods and by a comparison of the specific rotation of the hydrogenated products from termitomycesphins H and C. These cerebrosides possessed a unique modification by a hydroxyl group at the middle of the long-chain base, like earlier congeners termitomycesphins A F. Termitomycesphin G with a 16-carbon-chain fatty acid showed higher neuritogenic activity than that of termitomycesphin H with an 18-carbon-chain fatty acid. This effect was observed within the termitomycesphins, suggesting that the chain length of the fatty acyl moiety played a key role in the neuritogenic activity.