139244-26-1Relevant articles and documents
Synthesis of ganglioside lactams corresponding to GM1-, GM2-, GM3-, and GM4-ganglioside lactones
Wilstermann, Michael,Kononov, Leonid O.,Nilsson, Ulf,Ray, Asim K.,Magnusson, G?ran
, p. 4742 - 4754 (2007/10/02)
Ganglioside lactams are potentially useful analogs of ganglioside lactones, which are highly immunogenic derivatives of gangliosides. The lactam corresponding to the GM3-lactone saccharide has been synthesized by sialylation of a suitably protected lactose derivative carrying an azido group in the 2′-position, followed by reduction and ring closure to form GM3-lactam. Glycosylation in the 4-position of the central saccharide unit gave the GM2- and GM1-lactam saccharides. By a similar route, a 2-azido-Gal derivative was sialylated and treated as above to give the GM4-lactam saccharide. Deprotection gave the GM2-4-lactam saccharides in water soluble form, whereas attempted deprotection of the GM1-lactam caused its degradation. The GM3-lactam saccharide was coupled to ceramide, to afford the ganglioside lactam analog, and via a spacer to bovine serum albumin (BSA). The BSA conjugate was used as immunogen to raise monoclonal antibodies that cross-reacted with GM3-lactone. The antibodies were used in a histological staining of murine melanoma cells, clearly showing the presence of GM3-lactone on the cell surface. Keeping the GM2-4-lactam saccharides in D2O at 37 °C for 1 month caused marginal (0-11%) hydrolysis of the lactam ring.
