16] Synthesis and Characterization of Ganglioside GM3 Derivatives: Lyso-GM3, De-N-acetyl-GM3, and Other Compounds

Abstract

Publisher Summary This chapter discusses various methods developed for the synthesis of five G M3 derivatives, as based on (l) preferential hydrolysis of the N-acetyl group of sialic acid, (2) de-N-acylation of both N-acetylsialic acid and N-acylsphingosine, followed by selective N-acetylation of sialic acid by protection of the amino group of sphingosine in dpPC liposomes, and (3) preferential N-acetylation of the sphingosine amino group by catalytic N-acetylation in an aqueous micellar solution. Thus, the desired derivatives of G M3 (D l - D 5 ) can be prepared and their structures verified by proton magnetic resonance ( I HNMR) and mass spectrometry. The functional role of membrane gangliosides has been thought to be modulation of membrane proteins such as receptors and transporters, although the gangliosides themselves have been implicated as receptors for cell-cell and cell-microbe recognition. The procedures described in this chapter for G M3 can be applied to any ganglioside to give derivatives that may be useful for the study of the cell physiological and pharmacological effects of membrane gangliosides.