New Synthetic Inhibitors of Chymotrypsin

4-Substituted carbonylphenyl ester derivatives were prepared and their inhibitory effects on chymotrypsin, trypsin, thrombin, plasmin, pancreatic kallikrein, and plasma kallikrein were examined. Among the various inhibitors tested, 4-[2-(di-methylamino)ethylaminocarbonyl]phenyl 1,2,3,4-tetrahydro-1-naphthoate hydrochlo-ride (FK-316), 4-[(2-[4-pyrrolidinocarbonylmethyl)piperadino]ethyl)oxycarbonyll-phenyl 5-methoxyindole-3-acetate dihydrochloride (FK-375), 4-[(2-[4-(piperidinocar-bonylmethylpiperadino]ethyl)oxycarbonyl]phenyl 1-naphthylacetate dihydrochloride (FK-386), 4-[(2-[4-(2-[morpholino]ethyl)piperadino]ethyl)oxycarbonyl]phenyl 5-meth-oxy-2-methylindole-3-acetate trihydrochloride (FK-401) and 4-(4-isopropylpiperadino-carbonyl)phenyl 1,2,3,4-tetrahydro-1-naphthoate methanesulfonate (FK-448) were the most effective and specific inhibitors of chymotrypsin.