N-acyl migration in ceramides.
Upon exposure of truncated ceramides, such as N-acetyl-sphingenine, and long-chain ceramides to moderate acidic conditions, three derivatives are formed. Two of them turned out to be O-acylated sphingenine, 1-O- and 3-O-acyl-sphingenine, and the other was identified as sphingenine. Truncated dihydroceramides (e.g., N-acetyl- and N-hexanoyl-sphinganine) also show this type of rearrangement, which is therefore not related to the presence of the allylic hydroxy group or to the length of the N-acyl chain. Of particular concern is the fact that the O-acylated compounds, which can be considered sphingoid base analogs, can be formed in chloroform or chloroform-methanol mixtures upon storage. For long-term storage, methanol or dichloromethane is the preferred solvent. A procedure to document the presence/formation of such O-acylated sphingoid bases in ceramide solutions in the picomole range, based on reversed-phase chromatography after derivatization of their amino group with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, is presented.
Van Overloop
Helena
H
Katholieke Universiteit Leuven, Faculteit Geneeskunde, Departement Moleculaire Celbiologie, Afdeling Farmacologie, Leuven, Belgium.
Van der Hoeven
Gerd
G
Van Veldhoven
Paul P
PP
D000143:Acids / Q000494:pharmacology; D000215:Acylation / Q000187:drug effects; D002518:Ceramides / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure
D000143:Acids; D002518:Ceramides