Enkephalin analogues with 2′,6′-dimethylphenylalanine replacing phenylalanine in position 4

Enkephalin analogues with 2′,6′-dimethylphenylalanine replacing phenylalanine in position 4 Dermorphin tetrapeptide analogues with 2′,6′-dimethylphenylalanine (Dmp) substituted for aromatic amino acids have high μ opioid receptor binding and biological activities1 Stereospecific synthesis of (2 S )-2-methyl-3-(2′,6′-dimethyl-4′-hydroxyphenyl)-propionic acid (Mdp) and its incorporation into an opioid peptide Dermorphin and deltorphin heptapeptide analogues: replacement of Phe residue by Dmp greatly improves opioid receptor affinity and selectivity Systemic analgesic activity and .delta.-opioid selectivity in [2,6-dimethyl-Tyr1, D-Pen2, D-Pen5]enkephalin Development of Potent μ and δ Opioid Agonists with High Lipophilicity Syntheses of potent Leu-enkephalin analogs possessing β-hydroxy-α,α-disubstituted-α-amino acid and their characterization to opioid receptors [Cyclic] [D-Pen2,D-Pen5]enkephalin analogs with increased affinity and selectivity for .delta.-opioid receptors Novel Deltorphin Heptapeptide Analogs with Potent .delta. Agonist, .delta. Antagonist, or Mixed .mu. Antagonist/.delta. Agonist Properties Synthesis and Biological Activities of Cyclic Lanthionine Enkephalin Analogues:  δ-Opioid Receptor Selective Ligands