Fig. 1. Synthesis of di- and monomannosylated peptides DM and MM. 1,2-Mannobiose azide 8 or azidomannose 9 were used to perform CuAAC for introducing the carbohydrate moiety to propargylglycine-substituted peptide P1 on resin. Conditions: CuSO4·5H2O, TBTA, sodium ascorbate, DMF/H2O, r.t., 30–40 h, side chains of resin-bound P1 were still protected during CuAAC; DMF/DCM/MeOH wash; resin cleavage, global deprotection (TFA/phenol/water/triisopropylsilyl ether/EDT (82.5/5/5/5/2.5, v/m/v/v/v)), r.t., 3 h, purification, 10% (P2), 20% (P3); DM = dimannosylated peptide P2; MM = monomannosylated peptide P3.
