Peptide argininol “inverse substrates” of anisic acid: Novel inhibitors of the trypsin-like serine proteinases

Peptides containing a C-terminal argininol residue linked, via an ester bond, to anisic acid have been synthesized as putative inhibitors of trypsin-like serine proteinases. The most potent analogue, Boc-Ile-Glu-Gly-Arg-ψ-(CH2---O)---CO---C6H4-OMe, that was modelled on a known recognition sequence for the clotting enzyme factor Xa, was found to inactivate the protease with a second-order rate constant of 4.5 × 105 M−1.min−1.