Electrochemical one‐electron reduction of dioxomolybdenum complexes with tetradentate N2O2 or N2S2 ligands containing sec. amino groups result in deprotonation of the amino groups and loss of an oxo ligand as H2O. This biomimetically undesirable result is circumvented by synthesis of the ligand (VI) and its complexes (VIII) (which can be prepared also from dioxobis(acetylacetonato)molybdenum and (VI) with 80% yield) and (X).

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A series of carboxy-alkylamidated and 7V-acetylated amino acids and peptides were synthesized and examined for their ability to inhibit human leukocyte elastase. The Bocamino acid alkylamides were found to be potent specific and competitive inhibitors of this enzyme. They were found not to or only poorly inhibit several other serine proteinases such as bovine trypsin, α-chymotrypsin, porcine pancreatic elastase and human leukocyte cathepsin G at concentrations less than 10~4M. Specificity and maximum inhibition of human leukocyte elastase were achieved when the N-terminus of the amino acid was protected by a t-butyloxycarbonyl (Boc) group, the oligopeptide fragment consisted of valine residues and when the alkyl chain was between 10 and 12 carbon atoms in length and attached to the C-terminus of the peptide fragment. Highest inhibition was obtained with the compound Boc-[Val] 3 -NH[CH 2 ]n--CH 3 (K { = 0.2 ΙμΜ). These specific inhibitors were also found to be non-toxic after oral administration to mice and rats (LD 50 greater than 3.0 g/kg body weight).

Electrochemical one‐electron reduction of dioxomolybdenum complexes with tetradentate N2O2 or N2S2 ligands containing sec. amino groups result in deprotonation of the amino groups and loss of an oxo ligand as H2O. This biomimetically undesirable result is circumvented by synthesis of the ligand (VI) and its complexes (VIII) (which can be prepared also from dioxobis(acetylacetonato)molybdenum and (VI) with 80% yield) and (X).