A convergent synthesis for erythropoietin (EPO) 1-28 N-glycopeptide hydrazides was developed. In this approach, EPO 1-28 peptides were synthesized on the solid phase and converted to C-terminal hydrazides after cleavage from the resin. After selective deprotection of the Asp24 side chain, the desired glycosylamine was coupled by pseudoproline-assisted Lansbury aspartylation. Although the initial yields of the EPO 1-28 glycopeptides were satisfactory, they could be markedly improved by increasing the purity of the peptide using a reversed-phase high-performance liquid chromatography (RP-HPLC) purification of the protected peptide.
Keywords: HPLC; glycopeptide; purification; solid-phase peptide synthesis.
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