The molecule is a N-acylsphingosine 1-phosphate(2-) in which the N-acyl group is specified as octadecanoyl (stearoyl). It is a conjugate base of a N-octadecanoylsphingosine 1-phosphate.
[(E,2S,3R)-3-hydroxy-2-(octadecanoylamino)octadec-4-enyl] phosphate