{{Chembox | ImageFile = Deltorphin.svg | ImageClass = skin-invert-image | ImageSize = 250px | IUPACName = (3''S'')-3-[(2''S'')-2-[(2''S'')-2-[(2''S'')-2-[(2''S'')-2-[(2''R'')-2-[(2''S'')-2-amino-3-(4-hydroxyphenyl)propanamido]-4-(methylsulfanyl)butanamido]-3-phenylpropanamido]-3-(1''H''-imidazol-4-yl)propanamido]-4-methylpentanamido]-4-(methylsulfanyl)butanamido]-3-carbamoylpropanoic acid<br />or<br /><small>L</small>-tyrosyl-<small>D</small>-methionyl-<small>L</small>-phenylalanyl-<small>L</small>-histidyl-<small>L</small>-leucyl-<small>L</small>-methionyl-<small>L</small>-α-asparagine | OtherNames = Deltorphin A; Dermenkephalin |Section1={{Chembox Identifiers | CASNo = 119975-64-3 | PubChem = 3035060 | ChemSpiderID = 2299380 | SMILES = O=C(O)C[C@@H](C(=O)N)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](NC(=O)[C@@H](N)Cc1ccc(O)cc1)CCSC)Cc2ccccc2)Cc3c[nH]cn3)CC(C)C)CCSC | InChI = 1/C44H62N10O10S2/c1-25(2)18-34(42(62)50-32(15-17-66-4)40(60)51-33(38(46)58)22-37(56)57)52-44(64)36(21-28-23-47-24-48-28)54-43(63)35(20-26-8-6-5-7-9-26)53-41(61)31(14-16-65-3)49-39(59)30(45)19-27-10-12-29(55)13-11-27/h5-13,23-25,30-36,55H,14-22,45H2,1-4H3,(H2,46,58)(H,47,48)(H,49,59)(H,50,62)(H,51,60)(H,52,64)(H,53,61)(H,54,63)(H,56,57)/t30-,31+,32-,33-,34-,35-,36-/m0/s1 | InChIKey = BHSURCCZOBVHJJ-NWOHMYAQBV | StdInChI = 1S/C44H62N10O10S2/c1-25(2)18-34(42(62)50-32(15-17-66-4)40(60)51-33(38(46)58)22-37(56)57)52-44(64)36(21-28-23-47-24-48-28)54-43(63)35(20-26-8-6-5-7-9-26)53-41(61)31(14-16-65-3)49-39(59)30(45)19-27-10-12-29(55)13-11-27/h5-13,23-25,30-36,55H,14-22,45H2,1-4H3,(H2,46,58)(H,47,48)(H,49,59)(H,50,62)(H,51,60)(H,52,64)(H,53,61)(H,54,63)(H,56,57)/t30-,31+,32-,33-,34-,35-,36-/m0/s1 | StdInChIKey = BHSURCCZOBVHJJ-NWOHMYAQSA-N }} |Section2={{Chembox Properties | Formula = C<sub>44</sub>H<sub>62</sub>N<sub>10</sub>O<sub>10</sub>S<sub>2</sub> | MolarMass = 955.154 g/mol | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}
'''Deltorphin''', also known as '''deltorphin A''' and '''dermenkephalin''', is a naturally occurring, exogenous opioid heptapeptide and thus, exorphin, with the amino acid sequence Tyr-<small>D</small>-Met-Phe-His-Leu-Met-Asp-NH<sub>2</sub>.<ref name="pmid2542051">{{cite journal |vauthors=Kreil G, Barra D, Simmaco M | title = Deltorphin, a novel amphibian skin peptide with high selectivity and affinity for delta opioid receptors | journal = European Journal of Pharmacology | volume = 162 | issue = 1 | pages = 123–8 |date=March 1989 | pmid = 2542051 | doi = 10.1016/0014-2999(89)90611-0|display-authors=etal}}</ref><ref name="pmid2551734">{{cite journal |vauthors=Mor A, Delfour A, Sagan S | title = Isolation of dermenkephalin from amphibian skin, a high-affinity delta-selective opioid heptapeptide containing a D-amino acid residue | journal = FEBS Letters | volume = 255 | issue = 2 | pages = 269–74 |date=September 1989 | pmid = 2551734 | doi = 10.1016/0014-5793(89)81104-4| s2cid = 6095995 |display-authors=etal| doi-access = free }}</ref><ref name="pmid2544892">{{cite journal |vauthors=Erspamer V, Melchiorri P, Falconieri-Erspamer G | title = Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 86 | issue = 13 | pages = 5188–92 |date=July 1989 | pmid = 2544892 | pmc = 297583 | doi = 10.1073/pnas.86.13.5188| bibcode = 1989PNAS...86.5188E |display-authors=etal| doi-access = free }}</ref> Along with the other deltorphins (such as deltorphin I and deltorphin II) and the dermorphins, deltorphin is endogenous to frogs of the genus ''Phyllomedusa'' such as ''P. bicolor'' and ''P. sauvagei'' where it is produced in their skin, and is not known to occur naturally in any other species.<ref name="pmid2542051" /><ref name="pmid2551734" /><ref name="pmid2541018">{{cite journal |vauthors=Temussi PA, Picone D, Tancredi T | title = Conformational properties of deltorphin: new features of the delta-opioid receptor | journal = FEBS Letters | volume = 247 | issue = 2 | pages = 283–8 |date=April 1989 | pmid = 2541018 | doi = 10.1016/0014-5793(89)81353-5| s2cid = 84259225 |display-authors=etal| doi-access = free }}</ref> Deltorphin is one of the highest affinity and most selective naturally occurring opioid peptides known, acting as a very potent and highly specific agonist of the δ-opioid receptor.<ref name="pmid2542051" /><ref name="pmid2551734" /><ref name="pmid2544892" />
Deltorphins have an unusually high blood–brain barrier penetration rate. The nonselective opiate antagonist naloxone inhibits deltorphin uptake by brain microvessels, but neither the selective δ-opioid antagonist naltrindole nor a number of opioid peptides with different affinities for δ- or μ-opioid receptors compete with deltorphins for the transport.<ref>{{Cite journal|last1=Fiori|first1=Anna|last2=Cardelli|first2=Patrizia|last3=Negri|first3=Lucia|last4=Savi|first4=Maria Rosaria|last5=Strom|first5=Roberto|last6=Erspamer|first6=Vittorio|date=1997-08-19|title=Deltorphin transport across the blood–brain barrier|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=94|issue=17|pages=9469–9474|doi=10.1073/pnas.94.17.9469|issn=0027-8424|pmid=9256506|pmc=23226|bibcode=1997PNAS...94.9469F|doi-access=free}}</ref>
== See also == * Deltorphin I * Dermorphin
== References == {{Reflist|2}}
{{Opioidergics}}
Category:Analgesics Category:Opioid peptides
{{analgesic-stub}}