A simple and novel method for tritium labeling of gangliosides and other sphingolipids

A very simple method for introducing tritium specifically into the ceramide portion of gangliosides, neutral glycosphingolipids and sphingomyelin has been developed using potassium boro [3H]hydride and palladium as catalyst. In this way six different gangliosides, five different neutral glycosphingolipids and sphinomyelin with high specific radioactivity were prepared for the first time. This simple procedure which does not require sophisticated apparatuses is suitable for large scale preparation of tritium-labeled sphingolipids as well as for nanogram quantities of individual sphingolipids so as to serve for analytical purposes. During the course of the labeling procedure no degradation of even the most labile trisialosyl-gangliotetraosylceramide has been observed. The yield of tritiated compounds is almost quantitative. The specific radioactivity depends on the unsaturation of the ceramide moiety and the specific activity of the boro[3H]hydride employed.