The present invention relates to new compounds that act as specific inhibitors of the
cysteine protease dipeptidyl peptidase I (DP I). Those compounds are represented by the general formula and the pharmaceutical salts thereof, in which R is an acyl-residue including urethane and
peptide, or a branched or unbranched C1-C9
alkyl chain, a branched or unbranched C2-C9 alkenyl chain, a branched or unbranched C2-C9 alkynyl chain, a C3-C9 cycloalkyl, C4-C9 carbocyclic, C5-C14
aryl, C3-C9 heteroaryl, C3-C9 heterocyclic, all of the above residues may be optionally substituted, or is H, AS is an
amino acid or
a peptide mimetic thereof. The
amino acid is
peptide bound with R and R' is a branched or unbranched C1-C9
alkyl chain, a branched or unbranched C2-C9 alkenyl chain, a branched or unbranched C2-C9 alkynyl chain, a C3-C9 cycloalkyl, C4-C9 cycloalkenyl, C2-C9 heterocycloalkyl, C3-C9 heterocycloalkenyl, C5-C14
aryl, C3-C9 heteroaryl, C3-C9 heterocyclic, whereas the heterocycloalkyl, heterocycloalkenyl, heteroaryl, heterocyclic residue can have up to 6 hetero ring atoms, an
amino acid or
a peptide mimetic thereof, all of the above residues my be optionally substituted, or is H.