Synthesis of oligosaccharide structures unique to pituitary glycoprotein hormones

Abstract

The trisaccharide βDGalNac(1 → 4)βDGlcNAc(1 → 2)αDMan (2) and its 4″-O-sulfate ester (3) have been chemically synthesized as their 8-methoxycarbonyloctyl glycosides. Structures 2 and 3 contain oligosaccharide sequences unique to the asparagine-linked carbohydrate chains of pituitary glycoprotein hormones. The characteristic chemical shift for H-4 of the βDGalNAc residue in the sulfate ester 3 (4.692 ppm) is identical to that in the 1H nuclear magnetic resonance spectrum of glycopeptides isolated from bovine lutropin (luteinizing hormone), thus establishing the position of sulfation in the natural structures.