Synthesis of neoglycoproteins containing L-glycero-alpha-D-manno-heptopyranosyl-(1->4)- and -(1->5)-linked 3-deoxy-alpha-D-manno-oct-2-ulopyranosylonic acid (Kdo) phosphate determinants

The disaccharide allyl glycosides 4, 8, 13 and the trisaccharide 33 have been prepared using heptopyranosyl trichloroacetimidate 1 or the disaccharide bromide 27 as glycosyl donors followed by efficient O-phosphorylation via the amidite procedure. The allyl glycosides 4, 8 and 33 are converted into 3-(2-aminoethylthio)propyl glycosides and are coupled to bovine serum albumin. The resulting neoglycoconjugates 6 and 35 containing spacer-linked Heg-(1-->4)-Kdo and Hep-(1-->5)-Kdo 4-phosphate-(2-->6)-beta-GlcNAc residues correspond to part structures of the inner core region in bacterial lipopolysaccharide, whereas compound 10 contains the artificial analogue Hep-(1-->4)-Kdo 5-phosphate. The compounds may be used in immunochemical characterisation of monoclonal antibodies.