Collect. Czech. Chem. Commun. 1988, 53, 2877-2883

Di- and tripeptide N-alkyl- and N-aralkyl amides as chymotrypsin inhibitors

Evžen Kasafíreka, Irena Šutiakováb, Michal Bartíkb and Antonín Šturca

a Research Institute for Pharmacy and Biochemistry, 130 60 Prague 3
b Institute of Biochemistry and Agrochemistry, Veterinary University, 041 81 Košice


Two competitive inhibitors of chymotrypsin, Glt-Ala-Ala-Leu-EtPh and Glt-Ala-Ala-Pro-NH-EtPh, were synthesized and their inhibition constants Ki were determined. The Ki-determination was carried also with a set of peptides of type X-(Ala)nNH-Y, where X is 3-carboxypropionyl- or 4-carboxybutyryl-, n is 2 or 3 and Y is methyl, ethyl, diethyl, isopropyl, propyl, butyl, isobutyl and 2-phenylethyl. Chymotrypsin inhibition was observed only with peptides containing an aralkyl residue whereas peptides with an alkyl are without any effect. Glt-Ala-Ala-Leu-NH-EtPh shows the highest Ki-value (80 μmol l-1).