Chemoselective acylation of hydrazinopeptides: a novel and mild method for the derivatization of peptides with sensitive fatty acids

N-terminal α-hydrazinoacetylpeptides were synthesized and chemoselectively acylated on the hydrazine moiety with various fatty acid succinimidyl esters or N-(cholesterylcarbonyloxy) succinimide. The acylation was performed in water/2-methyl-propane-2-ol mixtures buffered at pH 5.1. The mild reaction conditions allow the derivatization of peptides by sensitive fatty acids.