Structure-Activity Relationships of Cyclic Pentapeptide Endothelin A Receptor Antagonists
作者:Takehiro Fukami、Toshio Nagase、Kagari Fujita、Takashi Hayama、Kenji Niiyama、Toshiaki Mase、Shigeru Nakajima、Takahiro Fukuroda、Toshihiko Saeki
DOI:10.1021/jm00021a021
日期:1995.10
D-heteroarylglycine was preferable at this position. Among synthesized cyclic pentapeptides, compound 36 (BQ-518) was the most potent ETA receptor antagonist, with a pA2 of 8.1 against ET-1-induced vasoconstriction in isolated porcine coronary arteries. This compound also showed the greatest selectivity between ETA and ETB receptors (IC50 for human ETA = 1.2 nM, IC50 for human ETB = 55 microM). In contrast, compound
天然产物内皮素A(ETA)受体拮抗剂的类似物环(-D-Trp1-D-Glu2-Ala3-D-Val4-Leu5-)(1)和环(-D-Trp1-D-Glu2-Ala3-D -alloIle4-Leu5-)(2)的制备和测试对[125I]内皮素(ET-1)与蛋白质ETA受体结合的抑制活性。天然产物的DDLDL手性序列似乎对于抑制活性至关重要,因为D-Trp或D-Glu(或两者)在1中转化为相应的L-异构体消除了该特性。在天然产物的每个位置上的系统修饰阐明了结构-活性关系,并导致了高效和选择性的ETA受体拮抗剂。D-Trp1和Leu5多数被其他氨基酸替代导致抑制活性的显着降低。相反,用D-Asp2替代D-Glu2增强了活性。关于Ala3的位置,所有具有亚氨基酸的类似物,无论是环状的还是无环的,都比氨基酸类似物具有更高的亲和力。另外,大多数在其侧链中具有各种官能团的氨基酸替代物并未显着改变ETA结合亲和力。D-Val4