![J Med Chem cover](/sites/default/files/styles/original_ratio_zero/public/2021-07/J%20Med%20Chem.png?itok=IaPS_X7m)
The Aba-Gly scaffold, incorporated into Dmt-Tic ligands (H-Dmt-Tic-Gly-NH-CH2-Ph, H-Dmt-Tic-Gly-NH-Ph, H-Dmt-Tic-NH-CH2-Bid), exhibited mixed μ/δ or δ opioid receptor activities with μ agonism. Substitution of Tic by Aba-Gly coupled to −NH−CH2−Ph (1), −NH−Ph (2), or −Bid (Bid = 1H-benzimidazole-2-yl) (3) shifted affinity (Ki(μ) = 0.46, 1.48, and 19.9 nM, respectively), selectivity, and bioactivity to μ-opioid receptors. These compounds represent templates for a new class of lead opioid agonists that are easily synthesized and suitable for therapeutic pain relief.