Helianorphin-19

Helianorphin-19 is a potent and selective κ-opioid receptor (KOR) agonist with high binding affinity (Ki = 25 nM) and functional activity (EC50 = 45 nM) . It demonstrates significant selectivity for KOR over μ- and δ-opioid receptors and provides effective peripheral analgesia in visceral pain models without central nervous system side effects like sedation.