Neuritogenic cerebrosides from an edible Chinese mushroom. Part 2: Structures of two additional termitomycesphins and activity enhancement of an inactive cerebroside by hydroxylation

Termitomycesphins E and F, novel cerebrosides that are hydroxylated around the middle of the long-chain base (LCB), have been isolated from the edible Chinese mushroom Termitomyces albuminosus (Berk.) Heim. ('Jizong' in Chine se) together with termitomycesphins A-D, and shown to induce neuronal diffe rentiation in rat PC12 cells. Their stereostructures have been determined b ased on their chemical derivatization and spectroscopic analysis. The major cerebroside obtained from the same mushroom was not hydroxylated around th e middle of the LCB and was inactive against PC12 cells, suggesting the imp ortance of the extra hydroxyl group on LCB. The Di- and tetrahydroxylation of this inactive cerebroside resulted in the enhancement of its neuritogeni c activity. (C) 2001 Elsevier Science Ltd. All rights reserved.