Synthesis of Spacered Disaccharides Structurally Related to the Fucosylated Chondroitin Sulfates from Sea Cucumbers Holothuria nobilis and Psolus peronii

Abstract

The synthesis of selectively 3,4′,6′-tri- and 3,4,4′,6′-tetra-O-sulfated derivatives of the aminopropyl glycoside of the disaccharide α-D-GalNAc-(1→2)-α-L-Fuc (1 and 2), structurally related to highly unusual carbohydrate chain fragments of hexosaminoglycans found in the side chains of fucosylated chondroitin sulfates (FCS) from sea cucumbers Holothuria nobilis and Psolus peronii, is described. Spacered disaccharides 1 and 2 were obtained via a common synthetic route involving selectively protected L-fucose and phenyl-1-seleno-2-azido-2-deoxygalactose building blocks, the latter synthesized by azidophenylselenylation of triacetylgalactal. Target compounds 1 and 2 will be used as model structures to identify the pharmacophoric elements within these FCS that are responsible for their biological activity.