Enzymic glycosphingolipid synthesis on polymer supports. III. Synthesis of GM3, its analog [NeuNAcalpha(2-3)Galbeta(1-4)Glcbeta(1-3)Cer] and their lyso-derivatives.

Two water-soluble polymers, carrying 0.24 meq g(-1) of lactosyl-beta(1-1)-sphingosine (7) and 0.13 meq g(-1) of lactosyl-beta(1-3)-sphingosine (8) were prepared. The polymers served as acceptors in the alpha-(2-3)-sialyltransferase reaction (up to 55.3 and 38.5% transfer yields, respectively). Subsequent photolysis, released compounds 11 (lyso-GM3) and 12 (lyso-GM3 analog), respectively; acylation and chromatography afforded (5-acetamido-3,5-dideoxy-D-glycero-alpha-galacto-2-nonulopyranosyloni c acid)-(2-3)-beta-D-galactopyranosyl-(1-4)-beta-D-glucopyranosyl-(1-1)-(2 S, 3R, 4E)-2-octadecanoylamino-4-octadecene-1,3-diol (13, GM3) and (5-acetamido-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylo nic acid)-(2-3)-beta-D-galactopyranosyl-(1-4)-beta-D-glucopyranosyl-(1-3)-(2 S, 3R, 4E)-2-octadecanoylamino-4-octadecene-1,3-diol (14, GM3 analogue), respectively, thus presenting a route to glycosphingolipids possessing the unusual glycosyl-beta(1-3)-spingosine linkage.