Glycerol phosphorylcholine (GPC) and serine ethanolamine phosphodiester (SEP): evolutionary mirrored metabolites and their potential metabolic roles.

Water-soluble phosphodiesters (WSPDE) are a prominent feature of many 31P-NMR spectra; however, their role has remained somewhat of a mystery. What has been missed in almost all previous studies is the fact that two classes of WSPDE exist in vertebrates: those in mammals and those in the other (reptile-avian) line. The first is represented by glycerol phosphorylcholine and the second by serine ethanolamine phosphodiester. A further examination of the literature suggests a common role for all WSPDE as lysophospholipase inhibitors and therefore net sparers of phospholipids by decreasing phospholipid metabolic throughput.