Ceramides structural variation

The structural variations observed in ceramides, cerebrosides and gangliosides isolated from sea stars are numerous and cover the three moieties of which glyco-sphingobpids are formed the sugar moiety, of which a dozen examples have been identified the acid moiety, which is almost always a mixture of a dozen fatty chains of varying lengths, saturated in general but sometimes... 

Sphingoglycolipids are components of the cell membrane and play a significant role in various biological processes [1,2]. Sphingoglycolipids are composed of at least one monosaccharide residue and long-chain aliphatic components known as ceramides (Cer). A typical structure is illustrated in O Fig. 1. They have diverse stmctural variations on both the ceramide and saccharide residues, and they are classified into many types according to carbohydrate sequence. The representative families are summarized in O Table 1. In this section, recent syntheses... 

Much more work has been done on GC of sphingolipids after conversion to simpler ceramides and thence to appropriate volatile derivatives, and these are eluted from GC columns under similar conditions to diacylglycerols (see Section C above). As ceramide standards are not readily available, and considerable variation in molecular structure can occur, identification of peaks can present enormous difficulty unless the analyst has access to GC-MS. Much of the early work in this area consisted of systematic studies with model ceramides, that provided a solid foundation for subsequent analyses of natural samples. The chromatographic conditions employed in the pioneering studies in 1969 were a glass column (1.2 m x 3 mm i.d.), containing 2 % OV-1 on GasChrom (60-80 mesh), maintained at temperatures of 300 to 320°C, with helium as the... 

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