Use of acid-labile protective groups for carbohydrate moieties in synthesis of glycopeptides related to type II collagen

beta-D-Galactopyranosyl and alpha-D-glucopyranosyl-beta-D-galactopyranosyl moieties carrying silyl, isopropylidene and 4-methoxybenzyl protective groups have been attached to the amino acid 5-hydroxy-L-norvaline. The resulting glycosylated building blocks were used in Fmoc solid-phase synthesis of glycopeptides related to a fragment from type II collagen which is immunodominant in a mouse model for rheumatoid arthritis. The protective groups used for the carbohydrate moieties were completely removed during acid catalyzed cleavage of the glycopeptides from the solid phase under conditions which left the O-glycosidic bonds intact. (C) 1998 Elsevier Science Ltd. All rights reserved.