Occurrence of phosphonotetraglycosyl ceramide in the sea hare Dolabella auricularia

Two kinds of phosphonoglycolipids were isolated from the sea hare Dolabella auricularia. One was phosphonopentaglycosyl ceramide with the same structure as that of the phosphonoglycolipid obtained from the sea hare Aplysia kurodai. The other, phosphonotetraglycosyl ceramide, was discovered in this study. Its structure was determined to be 3-O-Me-Gal alpha 1-3(AEP-6Gal alpha 1-2)Gal beta 1-4Glc beta 1-1-ceramide. The presence of tetraglycosyl and pentaglycosyl ceramides, the backbone structures of phosphonoglycolipids in the neutral glycolipid fraction, indicate that these neutral glycolipids are precursors of the phosphonoglycolipids.