Direct evidence by carbon‐13 NMR spectroscopy for the erythro configuration of the sphingoid moiety in Gaucher cerebroside and other natural sphingolipids

Abstract

By comparison of carbon‐13 NMR data from Gaucher cerebroside and from other natural sphingolipids with those from synthetic L‐threo‐ceramide, D‐glucosyl‐L‐threo‐ceramide, D‐erythro‐ceramide and D‐glucosyl‐D‐erythro‐ceramide, we have been able to obtain directly, for the first time, unequivocal evidence for the erythro configuration of the sphingosine moiety in natural sphingolipids. Gaucher cerebroside gave the same data as D‐glucosyl‐D‐erythro‐ceramide. In contrast, significant shift differences have been observed for sphingosine C‐3 (1.9 ppm) and C‐4(1.2 ppm) when comparing the spectral data of Gaucher cerebroside with those of D‐glucosyl‐L‐threo‐ceramide. Similar differences have also been found between the carbon‐13 NMR data of synthetic D‐erythro‐ceramide and those of L‐threo‐ceramide. In addition, we have observed that threo‐sphingosine C‐5 and C‐4 of ceramide and D‐glucosyl‐ceramide resonate near 129.5 ppm and 133.5 ppm, respectively, with a signal separation of about 4 ppm. On the other hand, these signals from the spectra of synthetic D‐erythro‐ceramide and D‐glucosyl‐D‐erythro‐ceramide as well as from those of gangliosides, lactosyl‐ceramide, galactosyl‐ceramide and sphingomyelin are found near 130 ppm and 135 ppm, respectively, thus being apart by about 5 ppm, irrespective of the degree of glycosylation of the ceramide portion. Thus, by carbon‐13 NMR spectroscopy the erythro configuration of the sphingoid base in natural sphingolipids is directly demonstrated. Copyright © 1985, Wiley Blackwell. All rights reserved