Sphingosine formation

Shfe, C.W., Wang, E., Hunter, R., Wang, S., Burgess, C., Liotta, D.C., and Merrill, A.H.Jr., 1989, Free sphingosine formation from endogenous substrates by a liver plasma membrane system with a divalent cation dependence and a neutral pH optimum. J. Biol. Chem. 264 10371-10377. 

The initial step in sphingosine formation involves the condensation of palmitoyl CoA with serine, which undergoes a simultaneous decarboxylation. 

FIGURE8.il Formation of an amide linkage between a fatty acid and sphingosine produces a ceramide. 

The transformation of the cyano group could also introduce a new chiral center under diastereoselective control (Figure 5.13). Grignard-transimination-reduction sequences have been employed in a synthesis of heterocyclic analogues of ephedrine [81]. The preferential formation of erythro-/3-amino alcohols may be explained by preferential hydride attack on the less-hindered face of the intermediate imine [82], and hydrocyanation of the imine would also appear to proceed via the same type of transition state. In the case of a,/3-unsaturated systems, reduction- transimination-reduction may be followed by protection of the /3-amino alcohol to an oxazolidinone, ozonolysis with oxidative workup, and alkali hydrolysis to give a-hydroxy-/3-amino acids [83]. This method has been successfully employed in the synthesis L-threo-sphingosine [84]. 

Alemany, R., Sichelschmidt, B., Meyer zu Heringdorf, D.M., Lass, H., Van Koppen, C.J. and Jakobs, K.H., 2000, Stimulation of sphingosine 1-phosphate formation by theP2Y2 receptor in HL-60 ceUs requirement and imphcation in receptor-mediated... 

Sphingosine bases are usually isolated from glycosphingolipids by treatment with methanolic HC1 containing some water,148 and characterized, in the form of the free bases or their 2,4-dinitrophenyl (DNP) derivatives,149 151 by t.l.c. For quantitative determination of bases, a colorimetric procedure is used, based on color formation of the base with Methyl Orange.152 The composition of the sphingosine bases, as their Me3Si derivatives, is determined by g.l.c. and g.l.c.-m.s.,148,153,154 as well as by using for this purpose... 

More than 25 years ago, Stoffel et al. (1970) reported the formation of sphingosine- 1-P in erythrocytes. This metabolite of sphingosine can be regarded as tranj -4-sphingenine-l-P (Figure 6-8). 

Figure 9.63 Relation between substrate concentration and rate of hydrolysis of galactosyl-N-DANS-sphingosine by crude /3-galactosidase. Galactosyl-W-DANS-sphingosine was hydrolyzed by crude /3-galactosidase (0.7 mg), and the formation of TV-DANS-sphingosine was measured by HPLC. (From Naoi and Yagi, 1981.)...

Figure 26.3. Synthesis of Sphingolipids. Sphingosine is converted into ceramide, which is an intermediate in the formation of sphingomyelin and gangliosides.

C. Palmitoyl CoA and serine react to form a precursor that is converted to sphingosine. Sphingosine does not contain a glycerol moiety. Formation of an amide with a fatty acyl CoA converts sphingosine to ceramide. Ceramide may be converted to sphingomyelin, cerebrosides, and gangliosides. 

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