Sphingophospholipids

The backbone of sphingomyelin is the amino alcohol sphingosine, rather than glycerol (Fig.1). A long-chain-length FA (LCFA) is attached to the amino group of sphingosine through an amide linkage, producing a ceramide, which can also serve as a precursor of glycolipids .
The alcohol group at carbon 1 of sphingosine is esterified to phosphorylcholine, producing sphingomyelin, the only significant sphingophospholipid in humans. Sphingomyelin is an important constituent of the myelin sheath of nerve fibers. [Note: The myelin sheath is a layered, membranous structure that insulates and protects neuronal axons of the central nervous system (CNS).]

Figure 1 : Structure of sphingomyelin, showing sphingosine (in green box) and ceramide components (in dashed box). = phosphate.