Synthesis of an N-glucoasparagine analog as a building block for a V3-loop glycopeptide from GP120 of HIV-I

The preparative synthesis of a new N4-(2-acetamido-2-deoxy-β-d-glucopyranosyl)-l-asparagine mimetic 1, starting from 2-amino-1,5-anhydro-2-deoxy-glucitol hydrochloride and Z-Asp-(OH)-OBn is described. This glycosyl-amino acid unit 1 is expected to show higher stabilities towards in vivo conditions. Further, the use of 1 as building block for the synthesis of modified glycopeptides using solid phase support is reported. The glycopeptide Ac-SXNTRKSIHIGPGRAF-NH2 having sugar-modified Asn2 mimics parts of the V3-loop structure containing the principle neutralizing determinant (PND) of HIV-1 and the naturally conserved glycosylation site within the V3 loop.