Opioid Activity Profiles of Oversimplified Peptides Lacking in the Protonable N-Terminus

Opioid Activity Profiles of Oversimplified Peptides Lacking in the Protonable N-Terminus Potent μ-Opioid Receptor Agonists from Cyclic Peptides Tyr-c[<scp>d</scp>-Lys-Xxx-Tyr-Gly]: Synthesis, Biological, and Structural Evaluation Synthesis of Tripeptides Containing <scp>d</scp>-Trp Substituted at the Indole Ring, Assessment of Opioid Receptor Binding and in Vivo Central Antinociception Synthesis and Evaluation of the Affinity toward μ-Opioid Receptors of Atypical, Lipophilic Ligands Based on the Sequencec[-Tyr-Pro-Trp-Phe-Gly-] Versatile Picklocks To Access All Opioid Receptors: Tuning the Selectivity and Functional Profile of the Cyclotetrapeptide c[Phe-<scp>d</scp>-Pro-Phe-Trp] (CJ-15,208) Nascent structure–activity relationship study of a diastereomeric series of kappa opioid receptor antagonists derived from CJ-15,208 Dermorphin sequence with high δ-afinity by fixing the phe sidechain to trans at ξ1 Synthesis and activity profiles of novel cyclic opioid peptide monomers and dimers Design, Synthesis, and Evaluation of Opioid Analogues with Non-Peptidic β-Turn Scaffold:  Enkephalin and Endomorphin Mimetics Endomorphin-1 Analogues Containing β-Proline Are μ-Opioid Receptor Agonists and Display Enhanced Enzymatic Hydrolysis Resistance