Synthesis and conjugation of a sulfated disaccharide involved in the aggregation process of the marine sponge Microciona prolifera

Abstract

The synthesis is reported of allyl (sodium 2-acetamido-2-deoxy-beta-D-glucopyranosyl 3-sulfate)-(1->3)-alpha-L-fucopyranoside which represents an oligosaccharide fragment of the aggregation factor of the marine sponge Microciona prolifera. The title compound was obtained by coupling of 3-O-allyloxycarbonyl-2-deoxy-4,6-O-isopropylidene-2-phthalimido-beta-D-glucopyranosyl trichloroacetimidate with allyl 2,4-di-O-benzoyl-alpha-L-fucopyranoside, followed by de-isopropylidenation, acetylation, de-allyloxycarbonylation, sulfation, de-acylation, and finally N-acetylation. The allyl glycoside was eventually converted into a 3-(2-aminoethylthio)propyl glycoside and then coupled to bovine serum albumin (BSA) using diethyl squarate as the bivalent linker, yielding 8 hapten molecules per molecule of BSA.