Structure-activity relationships of the oxindole growth hormone secretagogues.

  title={Structure-activity relationships of the oxindole growth hormone secretagogues.},
  author={Teruhisa Tokunaga and W. Ewan Hume and Jun Nagamine and Tetsuya Kawamura and Mutsuo Taiji and Ryu Nagata},
  journal={Bioorganic & medicinal chemistry letters},
  volume={15 7},
A series of substituted oxindole derivatives of SM-130686 was synthesized and evaluated as ghrelin receptor agonists. Modification of the substituents on the C3-aromatic part of the oxindole led to compounds with subnanomolar binding affinities. Compound 4i (IC(50)=0.02 nM) was orally active at low doses and showed in vivo activity when orally administered, 2 mg/kg twice a day for 4 days, as evidenced by significant body weight gain.