Peptidomimetic growth hormone secretagogues: Synthesis and biological activities of analogs varied at the indole nucleus of the prototypical spiropiperidine L-162,752

Article abstract of DOI:10.1016/0960-894X(96)00305-8

SAR studies around the indole nucleus of the prototypical peptidomimetic L-162,752 revealed that the D-Trp could be replaced with 3-phenylpropyl-D-glycine and O-benzyl-D-serine to provide secretagogues with comparable intrinsic activity but with significantly better oral activity in dogs. Use of dimethyl β-alanine amino side-chains led to a considerable loss of activity in the D-homophenylalanine and O-benzyl-D-serine series.