Synthesis of Fluorescent Gangliosides.

Labeled gangliosides are invaluable tools to study their transport and metabolism within cells as well as to determine their distribution in membranes, and their interaction with membrane lipids and proteins. Here I describe established procedures to synthesize ganglioside derivatives with a fluorescent tag either attached to its sialooligosaccharide or ceramide portion. These procedures are chosen as to minimize the integrity of the ganglioside molecule and hence, to leave their native skeleton formally intact. The α-position of the stearic acid residue is favorable for the attachment both of hydrophilic and of lipophilic dyes. In some other cases, and starting from lyso-gangliosides, procedures are described by which a fluorescent tag bound to a short acyl chain replaces the native acyl chain of gangliosides.