| 摘要 |
PURPOSE:To obtain a new cyclic hexapeptide for treating diseases such as hypertension, breast bang, cardiac infarction, asthma, arteriosclerosis, shock, etc., caused by endothelin, having excellent antagonistic activity on an endothelin receptor, comprising a specific hexapeptide. CONSTITUTION:A new cyclic hexapeptide of formula I [A is a D-acidic-alpha-amino acid residue; Y is an acidic-alpha-amino acid residue; C is an L-alpha-amino acid residue; R<1> is a group of formula II (X<1> and X<2> are each H, a 1-6C alkyl, a 1-6C alkoxy, a halogen, nitro or X<1> and X<2> are bonded to form a ring with an adjoining carbon atom); R<2> is a 1-6C alkyl, a 3-7C cycloalkyl, a 1-6C alkoxy, etc.; R<3> is H, a 1-6C alkyl, a 3-7C cycloalkyl, acyl, etc.] having excellent antagonistic activity on an endothelin receptor. The compound is obtained by condensing two kinds of fragments to be divided into two parts at an arbitrary position of the compound to form a straight-chain hexapeptide and then condensing the hexapeptide through ring closure. |
