Synthetic preparation and immunological evaluation of ß-mannosylceramide and related N-acyl analogues.

The synthesis of the invariant natural killer (iNK) T cell agonist ß-mannosylceramide along with a series of fatty amide analogues is reported. Of the six ß-glycosylation protocols investigated, the sulfoxide methodology developed by Crich and co-workers proved to be the most effective where the reaction of a mannosyl sulfoxide and phytosphingosine derivative gave a key glycolipid intermediate as a 95 : 5 mixture of ß- to α-anomers in high yield. A series of mannosyl ceramides were evaluated for their ability to activate D32.D3 NKT cells and induce antitumour activity.