Synthesis of artificial group A and B substances.

plementarily. He also announced,s),2a) being based on the phenomenon of interconversion in vitro of Group A and B in a group lipoid, that the foremost structural difference existing between Group A and B substances exists in which mode of union, ƒ¿or ƒÀ-glycosidic, the carbohydrate moity, which constitutes the determinant group, is linked with aglycon portion in the molecule. According to him, the aglycon most probably shields the right or wrong side of the plain carbohydrate molecule or one of the cut ends of the coiled carbohydrate molecule, laying the other side or the other cut end bare to combine with the agglutinin. Our later structural study3)4)4a) indicated that blood group lipoids are N-glycosides of poly saccharides consisting of chondrosamine, galactose and mannose or of hexosamines and galactose, and that the aglycon is a lipid-polypeptide complex whose glutamyl residue participates with its amino group in linkage with the polysaccharide. On the other hand Yamakawa5) discover ed, apart from our studies, remarkable group potency in " globo sides "6) which comprise an acylsphingosine and a carbohydrate made up of 1 molecule of N-acetylchondrosamine, 3 molecules of galactose and a trace of glucose. After these considerations, it appeared to us that group active substances might be prepared only by adequately fixing N-glycosidically a hexosamine-galactoside to different amphipatic structures, that form large micelles, such as phosphatidylpeptide, sphingosine and proteinic materials. Hence we synthesized two series of N-glycosides of hexosamine4-ƒÀ-galactoside and of its dimer, employing firstly various phosphatidyl-