D-erythro-C20-Sphingosine

Sphingosine is a characteristic structural unit of sphingolipids such as ceramides, gangliosides, globosides, sulfatides, sphingomyelin, and others.1 It is most abundant in nervous tissue and cell membranes. Sphingosine with an 18-carbon chain and a double bond at carbon 4 is the most abundant sphingosine in animal tissues but C20-sphingosine is the most abundant in many other organisms. C20-sphingosine acylated to gangliosides can be found in significant amounts in the central nervous system of mammals but is almost non-existent in other mammalian tissues.2 The ratio of C20:C18-sphingosine has been shown to increase with age in at least some mammals. Interestingly, in sialic acid containing sphingolipids an increase of C20-sphingosine is found to correspond with an increase in sialic acid groups. The seemingly minor difference between C18 and C20 sphingosines of two carbons results in significant differences in their physical and chemical properties such as aggregation characteristics and monolayer formation.3 These differences result in critical biological functions of their sphingolipid derivatives. Sialic acid containing sphingolipids such as gangliosides form micelles in water and this micellar size is directly influenced by the chain length of the sphingosine. Lysosphingolipids inhibit protein kinase C activity resulting in the pathogenesis of sphingolipidoses such as Krabbe's disease and Gaucher's disease. Sphingosine can be phosphorylated via two kinases to form sphingosine-1-phosphate, which has important signaling functions. While sphingosines and ceramides can induce apoptosis,4 sphingosine-1-phosphate can promote cell survival or proliferation. Sphingosine has been shown to cause an increase in the cytoplasmic calcium level of cells.