1. Sphingosine-N-(N-acetyl)-galactosaminido-4-β-galactoside (I), dihydrosphingosine-N-(N-acetyl)-galactosaminido-4-β-galactoside (II), α-glutamyl-(α, α'-dipalmitylglycerophosphoryl) -ethanolamine=N- (N-acetyl)-galactosaminido-4-β-galactoside (III), sphingosine-N-glucosido-6-β-galacto-side (IV), sphingosine-N-galactosido-4-β-galactoside (V), sphingosine-N-melibioside (VI) and -γ-glutamyl-(α, α'-dipalmitylglycerophosphoryl)-ethanolamine-N-melibioside (VII) were synthesized and examined regard-ing their potencies inhibiting hemagglutination of A, B and O erythrocytes by antisera.
2. I-IV are inhibitory to the agglutination of all A, B and O ery-throcytes although the inhibition degree varies from compound to com-pound and from antiserum to antiserum. V is not active at all. VI is specifically Group O(H) active, whereas VII which contains melibiose like VI is specifically Group B active, though weak. The disaccharides employed for the synthesis of the N-glycosides in 1., galactose, melibiose, lactose, raffinose and stachyose are devoid of any of those inhibitory powers.
3. Based on the findings, the spatial configuration of O substances is discussed.
Through the Grant Committee for Scientific Researches the Ministry of Education gave a grant in aid to us, which is gratefully acknowledged. H. Masamune.