BTRX-335140 is a potent and selective, orally active κ opioid receptor (KOR) antagonist, has antagonist activity for κOR, μOR and δOR with IC50 values of 0.8 nM, 110 nM, and 6500 nM, respectively.

Gluten exorphin C is an opioid peptide derived from wheat gluten. Its IC50 values are 40 μM and 13.5 μM for μ opioid and δ opioid activities in the GPI and MVD assays, respectively.Gluten Exorphin C, isolated from the pepsin-trypsin-chymotrypsin digest of wheat gluten, was considered as a δ-opioid receptor-selective ligand.Gluten exorphin C, a novel opioid peptide, is isolated from the pepsin-trypsin-chymotrypsin digest of wheat gluten.

A potent and selective δ-opioid receptor agonist that has high affinity and selectivity for the δ1 subtype with Ki of 1.12 nM.