Phosphocholine-bonded galactosylceramides having a tri-unsaturated long-chain base from the clam worm, Marphysa sanguinea.

Seven glycosphingolipids were obtained in the pure state from the clam worm, Marphysa sanguinea, by preparative HPLC with a reversed-phase column in a recycling mode. Their structures were elucidated based on detailed analyses of 1H- and 13C-NMR spectra of the intact compounds. The position and the geometry of double bonds in the long-chain base (LCB) were determined by the two-dimensional NMR (COSY, NOESY, and HMBC) analyses. All compounds are phosphocholine-bonded monogalactosylceramides and two of them have tri-unsaturated long-chain bases.