Peptide aldehyde as antithrombotic agent

PURPOSE: To obtain a novel peptide aldehyde which selectively exhibit serine protease inhibitory activity and is highly stable in aqueous solutions and useful as an anti-trypsin and anti-thrombin active substance. CONSTITUTION: The objective peptide aldehyde is represented by the formula [R 1 and R 2 are each H or COOR (wherein R is H, an alkyl, benzyl or the like); R 3 and R 4 are each H, an alkyl, benzyl, phenyl, a cyclo-alkyl or the like or both are linked to form a 3-7C cycloalkyl, phenyl or the other aromatic rings; R 5 is H or an alkyl or R 5 is linked with R 3 or R 4 to form a 3-7C heterocyclic ring; X is CO, (CH 2 ) m (wherein (m) is 0-3) or SO 2 ; Y is (CH 2 ) m , CH 2 CH-NHR 8 (wherein R 8 is an alkyl or benzyl) or SO 2 R 9 (wherein R 9 is an alkyl, phenyl or the like); when Y is (CH 2 ) m , R 6 is (CH 2 ) m R 10 (wherein R 10 is phenyl, pyridyl, naphthyl, quinolinyl or the like); R 7 is CHO, CH 2 OH or COOH; and (n) is -1, -2 or 0-4] and includes, e.g. Nα-[N-(3-(3-pyridyl)propa-noyl)-L-prolyl]-L- argininaldehyde dihydrochloride. COPYRIGHT: (C)1995,JPO