sponge Amphimedon compressa has shown it to contain two novelglycosphingolipids, amphiceramide A (1a) and B (2a), which possess an unusual Δ6-phytosphingosine. The saccharide chain of amphiceramide A is composed of a β-glucose residue glycosylated at the 6-position by an N-acetyl-β-glucosamine and has never been found before in a natural product. The saccharide chain of amphiceramideB consists of an