Synthesis of four spacer-containing 'tetrasaccharides' that represent four possible repeating units of the capsular polysaccharide of Streptococcus pneumoniae type 6B

摘要

In the framework of studies towards oligosaccharide-conjugate based vaccines against Streptococcus pneumoniae, the synthesis is reported of four spacer-containing 'tetrasaccharides' that each can be conceived as representing a repeating unit of the capsular polysaccharide of S. pneumoniae serotype 6B, namely, 3-aminopropyl D-ribityl-(5 --> hydrogen phosphate --> 2)-alpha-D-galactopyranosyl-(1 --> 3)-alpha-D-glucopyranosyl-(1 --> 3)-alpha-L-rhamnopyranoside, 3-aminopropyl alpha-L-rhamnopyranosyl-( 1 --> 4)-D-ribityl-(5 --> hydrogen phosphate --> 2)-alpha-D-galactopyranosyl-( 1 --> 3)-alpha-D-glucopyranoside, 3-aminopropyl-alpha-D-glucopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-( 1 --> 4)-D-ribityl-(5 --> hydrogen phosphate --> 2)alpha-D-galactopyranoside, and alpha-D-galactopyranosyl-(1 --> 3)-alpha-D-glucopyranosyl-(1 --> 3) alpha-L-rhamnopyranosyl-(1 --> 4)-5-O-(3-aminopropyl hydrogen phosphate)-D-ribitol. Phosphorylations were carried out using the H-phosphonate method. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 31]