Synthèse de la L‐arginyl‐L‐prolyl‐L‐prolyl‐glycyl‐L‐phénylalanyl‐L‐Séryl‐L‐prolyl‐L‐phénylalanyl‐L‐arginine, un nonapeptide présentant les propriétés de la bradykinine

The synthesis of a nonapeptide exhibiting bradykinin‐like properties is described. Condensation of CBO‐(nitro)Arg‐Pro‐OH with H‐Pro‐Gly‐NHNH‐CTO and selective splitting of the CTO‐group yielded CBO‐(nitro)Arg‐Pro‐Pro‐Gly‐NHNH 2 . CBO‐Phe‐ Ser‐N 2 was condensed with H‐Pro‐Phe‐(nitro)Arg‐OBzN, the CBO‐group was selectively split, and the resulting pentapeptide was made to react with the azide corresponding to the above‐mentioned hydrazide. All the protective groups of the resulting nonapeptide were split off by catalytic hydrogenolysis, giving pure H‐Arg‐ Pro‐Pro‐Gly‐Phe‐Ser‐Pro‐Phe‐Arg‐OH after counter‐current distribution. On a molar basis, this nonapeptide was more active than histamine (ileum, bronchial muscle and capillary permeability of the guinea pig) and acetylcholine (duodenum of the rabbit, blood pressure of the rabbit and dog).