J . Med. Chem. 1988,31, 1430-1436
1430
Dopamine Receptor Modulation by Conformationally Constrained Analogues of Pro-Leu-Gly-NH2 Kuo-Long Yu,' G. Rajakumar,*Lalit K. Srivastava,f Ram K. Mishra,t and Rodney L. Johnson*+ Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, and Departments of Psychiatry and Neurosciences, McMaster University Health Sciences Center, Hamilton, Ontario L8N 325, Canada. Received January 7, 1988
Two series of conformationally constrained analogues of Pro-Leu-Gly-NHz (PLG) have been synthesized. In one series of analogues, the Leu-Gly-NHz dipeptide segment of PLG was replaced with the y-lactam residues 3(S)- and 3(R)-amino-2-oxopyrrolidineacetamideand the d-lactam residue 3(S)-amino-2-oxopiperidineacetamide.The corresponding y-lactam analogues of
