Sphingoid bases mass spectrometry

Berdyshev, E. V., Gorshkova, I. A., Garcia, J. G., Natarajan, V., Hubbard, W. C. Quantitative analysis of sphingoid base-1-phosphates as bisacetylated derivatives by liquid chromatography-tandem mass spectrometry. Anal Biochem 339 (2005) 129-136. 

Jungalwala, F. B., Evans, J. E., Kadowaki, H. and McCluer, R. H. (1984) High performance liquid chromatography-chemical ionisation mass spectrometry of sphingoid bases using moving-belt interface. J. Lipid Res., 25, 209-16. 

Aldehydes are more easily identified than are the parent compounds, since a wide range of standards is available from commercial sources or can be prepared synthetically from other lipids. As an example of the full application of this methodology, more than 30 different bases were detected in the sphingolipids of bovine kidney [469]. Mass spectrometry can be utilised as an aid to identification of aldehydes (see also Section B above), although some workers have preferred to reduce them to fatty alcohols and then to prepare acetate or TMS ether derivatives for this purpose [624]. In addition, all the methods for the location of double bonds in fatty acids, such as ozonolysis or hydroxylation with osmium tetroxide and preparation of TMS ethers for MS, have been utilised with aldehydes prepared from sphingoid bases [464,465]. 

One further type of derivative of sphingoid bases for GC-MS purposes is worthy of note, i.e. cyclic boronates [277]. Usually, it is necessary to protect the amine group, but a b/s-boronate derivative is formed from trihydroxy bases. Model compounds, prepared from standards, had excellent GC properties and also exhibited distinctive fragmentation properties on mass spectrometry. For example, they gave molecular ions in reasonable abundance. Unfortunately, they do not appear to have been applied to the analysis of natural samples. 

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