Oliver Scheel

Synthesis of Glycosyl Glycerols and Related Glycolipids

Abstract Several isomeric glycosyl glycerols were synthesized. Acetylated allyl glycosides of D-glucose and D-galactose were transformed into l-O-(glycopyranosyl)-rac-glycerols in a three step procedure via the corresponding 2,3-epoxypropyl glycosides and the peracetylated glycosyl glycerols. Tetra-O-benzyl-D-glucose was glycosylated with 1,3-di-O-benzylglycerol to give the α-aiomer preferentially. The 2-O-(tetra-O-acetyl-β-glycopyranosyl)-sn-glycerols and 2-O-(β-glycopyranosyl)-sn-glycerols of D-glucose, D-galactose and N-acetyl-D-glucosamine and the corresponding α-derivatives of D-mannose were synthesized by selective glycosylation methods from 1,3-di-O-benzylglycerol and 1,3-O-benzylideneglycerol, respectively, and activated sugar compounds followed by hydrogenolysis. After long chain acylation and selective deacetylation the 1,3-di-O-acyl-2-O-(β-glycopyranosyl)-sn-glycerols of D-glucose, D-galactose and N-acetyl-D-glucosamine and the corresponding α-derivative of D-mannose were synthesized.

Enzymatic Galactosylation of Cello‐ and Chito‐Oligomers

Terminal galactosylations of cello‐ and chito‐oligomers are studied employing galactosyltransferase with and without α‐lactalbumin. The lactose synthase complex allows just for galactosylation of cellobiose in lower yield but not for higher cello‐oligomers. In contrast, the affinity in galactosylation of chito‐oligomers increases with higher members to reach the maximum at chitohexaose with only a 30% reduction in transfer rate. In addition to kinetic data, preparative studies with a number of acceptor substrates gave galactosylated oligosaccharides in high yields.