Dermorphin and deltorphin are naturally occurring heptapeptides purified from skin extracts of the South American frog Phyllornedusa sauvagei that show high affinity and selectivity for μ and δ opioid receptors, respectively. They share a similar N-terminal tripeptide sequence Tyr-D-Xaa-Phe, where D-Xaa is either D-Ala (dermorphin) or D-Met (deltorphin), and have an amidated COOH terminus. The two dermorphin-like peptides(Dermorphin 1 and Dermorphin 8) have a similar affinity and selectivity for the mu opioid receptor as dermorphin.
Mignogna G, Severini C, Simmaco M, et al. Identification and characterization of two dermorphins from skin extracts of the Amazonian frog Phyllomedusa bicolor. FEBS Lett. 1992;302(2):151-4.