Leu-enkephalin
| Names | |
|---|---|
| IUPAC name (2R)-2-[[(2R)-2-[[2-[[2-[[(2R)-2-amino-3- | |
| Other names [Leu]enkephalin; [Leu5]enkephalin; | |
| Identifiers | |
| 3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.055.852 | 
| PubChem CID | |
| UNII | |
| CompTox Dashboard (EPA) | |
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| Properties | |
| C28H37N5O7 | |
| Molar mass | 555.62 g/mol | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Leu-enkephalin is an endogenous opioid peptide neurotransmitter with the amino acid sequence Tyr-Gly-Gly-Phe-Leu that is found naturally in the brains of many animals, including humans. It is one of the two forms of enkephalin; the other is met-enkephalin. The tyrosine residue at position 1 is thought to be analogous to the 3-hydroxyl group on morphine. Leu-enkephalin has agonistic actions at both the μ- and δ-opioid receptors, with significantly greater preference for the latter. It has little to no effect on the κ-opioid receptor.
A nasal spray formulation of leu-enkephalin (developmental code names NES-100, NM-0127, NM-127, PES-200; proposed brand name Envelta) is under development by Virpax Pharmaceuticals for the treatment of pain and post-traumatic stress disorder (PTSD). As of November 2023, it is up to the preclinical stage of development for these indications.