New glycosphingolipids from the marine sponge Halichondria panicea.

A novel sphingolipid containing an iso-fatty acid, (4E,8E)-N-13'-methyltetradecanoyl-1-O-beta-D-glucopyra nosyl-4-sphingadiene, was isolated from the Oregon marine sponge Halichondria panicea and its structure determined using a combination of spectroscopic and chemical degradation techniques. A second galactosyl-ceramide, which contained an unusually long chain fatty acid amide component, was also isolated from H. panicea.