Ceramide structure and derivatives

Ceramide belongs to waxy lipid biomolecules family (Latin Cera word means wax). Structure of ceramide is constituted by sphingosine alcohol and a fatty acid linked by an amide bond. Ceramide is precursor for many sphingolipids which are ubiquitously present in eukaryotic cell membrane, involved in myriad signalling pathways. The length of fatty acid may vary from C14 to C25. Ceramide becomes influential due to their presence in sphingomyelin present in myelin sheath of neurons. Ceramide and their derivatives are endowed with functions like regulating differentiation, cell proliferation and apoptosis. The sphingosine is a nitrogen-containing acyl amino alcohol synthesised from palmitoyl-CoA and serine. The acyl group is attached at amino group. This rate-limiting reaction requires PLP, NADPH and Mn++. 3-keto sphinganine formed here is reduced to dihydro sphingosine