Structure of a pentahexosylceramide (Forssman hapten) from canine intestine and kidney.

A pentahexosylceramide isolated from canine kidney and intestine was shown by enzyme hydrolyses, partial acid hydrolysis, permethylation and analysis of the products by gasliquid chromatography-mass spectrometry, and serological tests to be a Forssman hapten identical in structure with the Forssman glycolipid from horse spleen. The assigned structure was N-acetylgalactosaminyl(otl +d)N-acetylgalactosaminyl(~l-+3)galactosyl(crl+4)galactosyl(~l-+4)glucosyl(I +l)ceramide. In the course of this work, mass spectrometry was employed to elucidate the structures of partially methylated alditol acetates derived from hexosamines.