The name hydrazinopeptide designates peptidic structures in which one of the native CONH links is replaced by a CONHNH (hydrazido) fragment. In this paper, we report the synthesis of such hydrazinohexapeptides (3-5) analogous to Z-Ala-Ala-Pro-Val-Ala-Ala-NH i Pr (6), a substrate of human leukocyte elastase (HLE; EC 3.4. 21.37), cleaved by this serine protease between the Val4 and Ala5 residues. In hydrazinopeptides 3-5, the Ala5, Val4, or Pro3 ...
