From LP2 to 2S-LP2: discovery of a biased dual-target mu/delta opioid receptor agonist for pain management Rita Turnaturi 1*, Carmela ParenC 2 , Girolamo Calò 3 , SanCna Chiechio 2 , AgosCno Marrazzo 1 and Lorella Pasquinucci 1 1 Department of Drug Sciences, Medicinal Chemistry Sec:on, University of Catania, Catania, Italy 2 Department of Drug Sciences, Pharmacology and Toxicology Sec:on, University of Catania, Catania, Italy 3 Department of Medical Sciences, Pharmacology sec:on, University of Ferrara, Ferrara, Italy * Corresponding author: rita.turnaturi@unict.it 1