Die Erfindung betrifft Peptidmimetika aus den Resten P4-P3-P2-P1, die zwischen den Seitenketten der P3- und P2-Aminosäuren zyklisiert wurden und als Hemmstoffe der Serinprotease Plasmin geeignet sind, die Fibrinolyse zu hemmen und dadurch den Blutverlust bei hyperfibrinolytischen Zuständen, beispielsweise bei Operationen, zu reduzieren.(19S,22R)-22-Amino-3,12,21-trioxo-2,6,9,13,20-pentaazatetracyclo[22.2.2.2(6,9).2(14,17)]dotriaconta-1(26),14,16,24,27,29-hexaene-19-carbaldehyde derivatives (I) excluding (19S,22R)-N-[(4-carbamimidoylphenyl)methyl]-22-methanesulfonamido-3,12,21-trioxo-2,6,9,13,20-pentaazatetracyclo[22.2.2.2(6,9).2(14,17)]dotriaconta-1(26),14,16,24,27,29-hexaene-19-carboxamide derivatives (III), are new. (19S,22R)-22-Amino-3,12,21-trioxo-2,6,9,13,20-pentaazatetracyclo[22.2.2.2(6,9).2(14,17)]dotriaconta-1(26),14,16,24,27,29-hexaene-19-carbaldehyde derivatives of formula (I) and their salts and prodrugs, excluding (19S,22R)-N-[(4-carbamimidoylphenyl)methyl]-22-methanesulfonamido-3,12,21-trioxo-2,6,9,13,20-pentaazatetracyclo[22.2.2.2(6,9).2(14,17)]dotriaconta-1(26),14,16,24,27,29-hexaene-19-carboxamide derivatives of formula (III), are new. n : 1 or 2 m : 0-2 R1 : H or up to 3C alkyl (optionally branched) R2 : up to 5C alkyl (optionally branched), up to 7C aryl, up to 7C aralkyl or H P1 : substituted benzylamino moieties of formula (IIa), substituted pyridin-3-yl-methylamino moieties of formula (IIb), substituted pyridin-2-yl-methylamino moieties of formula (IIc), 4-(aminomethyl)benzylamino, substituted thiophen-2-yl-methylamino moieties of formula (IId), substituted thiazol-2-yl-methylamino moieties of formula (IIe), substituted thiazol-5-yl-methylamino moieties of formula (IIf), (4-amino-cyclohexylmethyl)-amino, -NH-CH 2-(CH 2) x-CH 2-NH-C(=NH 2)-NH 2or -NH-CH 2-(CH 2) x-CH 2-CH 2-NH 2 R3 : H, OH, O-CH 3, NH 2, O-CO-CH 3or CO-O-(CH 2) z-CH 3 z : 1-5 x : 1-3 P4 : H, SO 2-R4, SO 2-NH 2, SO 2-NH-R4, SO 2-N(R4) 2, CO-O-R4, CO-R4, CH 2-COOH or CH 2-COO-C 2H
