Sphingosine and Dihydrosphingosine

With the elucidation of the structure of 18 sphingosine, Zabin and Mead 

The results of these experiments have been recalculated from the data of Zabin and Mead (1953, 1954) and Sprinson and Coulon (1954) and are presented in Table 1. It is immediately apparent from this data that acetate labelled in either the one or two positions gives rise exclusively to the hydrocarbon portion of the sphingosine. Degradation of the palmitic acid derived from the sphingosine labelled with acetate-2-shows that carbon 4 is 3 to 5 times richer in than carbons 3 or 5. This is consistent with the pattern observed during fatty acid synthesis 

Determined after reduction to dihydrosphingosine (see text). Adopted from the data of Zabin and Mead (1953, 1954) and Sprinson and Coulon (1954). 

In vivo studies indicate the formation of sphingosine as formulated in the following reaction  

With this reaction in mind, Brady and Kovajl (1957, 1958) demonstrated that incubating DL-serine-3- C in the presence of pyridoxal phosphate, magnesium chloride, TPN, DPN, and an unidentified substance present in a kochsaft prepared from rat liver would yield sphingosine containing radioactivity in the presence of a dialyzed brain supernatant preparation. Subsequent studies by Brady and Koval (1957, 1958) and Brady et al. (1958) have delineated an enzyme system capable of the step-wise synthesis of 18 sphingosine. 

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Precoated silica gel plates (silica gel 60) were purchased from Scientific Products. Bio-Sil A (200 - 400 Mesh) was obtained from Bio-Rad Laboratories. Fatty acid methyl esters, sphingosine and dihydrosphingosine were products of Supelco, Inc. as were 10% DEGS-PS, 3% SP-2340 and 3% OV-17 (all on Supelcoport support). N-acetyl and N-glycolyl neuraminic acid, DEAE-Sephadex A50 and neuraminidase type IX were obtained from Sigma Company. Ganglio-side standards from human brain and neutral glycosphingolipid standards from bovine erythrocytes were prepared in this laboratory. 

Sphingolipids are built from long-chain, hydroxylated bases rather than from glycerol. Two such bases are found in animals sphingosine and dihydrosphingosine (sphinganine), with the former being much more common. 

Sphingolipids. The sphingolipids contain Cis hy-droxyamino alcohols. Four such long-chain hy-droxyamino alcohols have been isolated from natural lipids. Sphingosine and dihydrosphingosine are typical of animal tissues. 

Sphingosines and dihydrosphingosines do not exist in the free state in animals, plants, or micro-organisms. 

On sphingosine. The oxidation of sphingosine and dihydrosphingosine. J. biol. Chem. 

Fig. 2. Spectrophotometric measurement of the reduction of Safranin T by dihydrosphingosine ( ) and sphingosine (O)-At Arrow 1.0.4 imo1e of sphingosine and dihydrosphingosine hydrochlorides suspended in 10 mg. of bovine serum albumin were added to the respective cuvettes At Arrow 2, 0.2 / mole of additional substrate was added. From Brady and Koval (1958)...

Snell, E.E., Dimari, S.J., and Brady, R.N. 1970. Biosynthesis of sphingosine and dihydrosphingosine by cell-free systems from Hansenula ciferri. Chem Phys. Lipids 5 116-138. 

For synthesis of phytosphingosine [40] and dihydrosphingosine [7], many methods have been reported. These utihzed a chiral pool strategy with amino acid or carbohydrate similar to that of sphingosine. 

Mammalian SC ceramides contain one of four sphingoid bases, namely sphingosine, 6-hydroxysphingosine, phytosphingosine and dihydrosphingosine... 

Nine different commercially available ceramides (Ceramide III, IIIB, and VI N-palmitoyl-, V-stearoyl-, V-oleoyl- and V-nervonoyl-D-sphingosine, and V-palmi-toyl- and V-lignoceroyl-DL-dihydrosphingosine) were analyzed on a 30°C Cj colunm (ELSD), drift tube 35 C, N2 at 1 bar) using a 15-tnin 95/5/0 — 35/5/60 acetonitrile/THF/n-propyl alcohol (all phases made lOmM in both triethylamine and formic acid) gradient. The authors studied the effects of mobile phase components (methanol and dichloromethane offered no advantages). Peak area was shown to be a strong positive function of mobile phase modifier concentration from 1 to 10 mM, whereas the overall retention was unaffected [1037]. 

Inhibitors of autotaxin/lysophospholipase D have yet to be identified. However, inhibitors of sphingosine kinase, such as dimethylsphingosine and dihydrosphingosine, potentiate the cell death induced by recognized anticancer treatments, are effective in drug- and radiation-resistant cancer cells and have shown significant inhibition of cancers in preclinical trials (Cuvillier and Levade, 2003). 

Two final questions remained, first, is the product of the reaction of serine with palmitaldehyde dihydrosphingosine or sphingosine and second, does an enzyme exist in tWs brain enzyme system which will convert dihydrosphingosine to sphingosine ... 

This enzyme, which has been purified some 200-fold, also catalyzes the synthesis of ceramide from sphingosine and free fatty acid. Acyl CoA derivatives are active only after hydrolysis by thiolase to release free fatty acid which is then available to condense with sphingosine. Attempts to dissociate these enzymic processes from one another have been unsuccessful. The preparation showed hydrolytic activity (ceramidase) toward A-palmitoyl, oleoyl, and stearoyl sphingosine, as well as with. V-palmitoyl dihydrosphingosine. Cerefarosides, sphingomyelin, and iV-acetyl sphingosine were not cleaved. 

Fatty acids and sphingosines. The lipid composition of the four monosialogangliosides is shown in Table II. The major fatty acids are palmitic, stearic and oleic acids. The long chain base is composed mainly of C-18 sphingosine with less than 20% of dihydrosphingosine. 

Stewart, M.E., and Downing, D.T., Free sphingosines of human skin include 6-hydroxysphingosine and unusually long-chain dihydrosphingosines, J. Invest. Dermatol., 105, 613, 1995. 

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