Chemical and hemolytic properties of sphingolipids modified by ozonolysis and reduction

Various sphingolipids were chemically modified in their sphingosine base by ozonolysis and reduction. The derivatives obtained from Forssman globoside, globoside I, galactosyl ceramide, and sphingomyelin were purified and all were found to be hemolytic. The presence of cholesterol could inhibit this activity. The simultaneous cleavage at a double bond in the fatty acid as well as in the sphingosine of Forssman globoside resulted in the formation of a more polar compound with no detectable hemolytic activity. The haptenic reactivity was retained after ozonolysis and reduction of Forssman globoside, as shown by precipitin line formation in agar gel with appropriate antibodies. The results indicate that this modification procedure may be useful in studies of the physiological and immunological properties of sphingolipids.