The synthesis of internal standards for the quantitative determination of sphingolipids by tandem mass spectrometry.
Novel internal standards have been synthesised for the quantitative determination by tandem mass spectrometry (MS/MS) of the sphingolipids that accumulate in lysosomal storage diseases. The [d4]C16- and [d47]C24-isoforms of galactosylceramide (CMH), lactosylceramide (CDH), globotriaosylceramide (CTH), cerebroside sulphate, sphingomyelin and G(M1)-, G(M2)- and G(M3)-gangliosides were synthesised by the reaction of their lyso-forms with the acid chlorides of hexadecanoic 5,5,6,6-d4 acid ([d4]-palmitic acid) and tetracosanoic-d47 acid ([d47]-lignoceric acid), respectively. The acid chlorides were formed using oxalyl chloride. The structures of the internal standards were confirmed by MS/MS. The fragmentation pattern of each novel compound was similar to that of the corresponding natural form of the sphingolipid, making it a good internal standard for the quantitative determination of the natural sphingolipid by ESI-MS/MS. Characteristic product ions were identified for each compound.
Mills
Kevin
K
Biochemistry, Endocrinology and Metabolism Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
Eaton
Simon
S
Ledger
Victoria
V
Young
Elisabeth
E
Winchester
Bryan
B
D016464:Lysosomal Storage Diseases / Q000378:metabolism; D012015:Reference Standards; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013107:Sphingolipids / Q000032:analysis / Q000138:chemical synthesis* / Q000378:metabolism
D013107:Sphingolipids