Compounds > phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide

phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide and enkephalin, d-penicillamine (2,5)-

phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide has been researched along with enkephalin, d-penicillamine (2,5)- in 31 studies

Research

Studies (31)

Timeframe	Studies, this research(%)	All Research%
pre-1990	3 (9.68)	18.7374
1990's	19 (61.29)	18.2507
2000's	7 (22.58)	29.6817
2010's	2 (6.45)	24.3611
2020's	0 (0.00)	2.80

Authors

Authors	Studies
Levine, JD; Miaskowski, C	1
Jacobson, AE; Ni, Q; Rice, KC; Rothman, RB; Xu, H	1
Lawrence, AJ; Traynor, JR	1
Bals-Kubik, R; Herz, A; Shippenberg, TS	1
Suh, HH; Tseng, LF	1
Herz, A; Shippenberg, TS; Spanagel, R	1
Gulya, K; Hawkins, KN; Hruby, VJ; Kazmierski, W; Knapp, RJ; Lui, GK; Pelton, JT; Wan, YP; Yamamura, HI	1
Gulya, K; Hruby, VJ; Pelton, JT; Yamamura, HI	1
Gulya, K; Hruby, VJ; Kazmierski, W; Lui, GK; Pelton, JT; Yamamura, HI	1
Kradel, BK; Monroe, PJ; Smith, DJ; Smith, DL	1
Crisp, T; Keck, BJ; Stafinsky, JL; Uram, M	1
Almeida, OF; Shippenberg, TS; Spanagel, R	1
Búzás, B; Cox, BM; Izenwasser, S	1
North, RA; Tanaka, E	1
Carter, BD; Medzihradsky, F	1
North, RA; Sugita, S	1
Gouardères, C; Jhamandas, K; Sutak, M; Zajac, JM	1
Davis, P; Horvath, R; Hruby, VJ; Lipkowski, AW; Misicka, A; Porreca, F; Yamamura, HI	1
Aghajanian, GK; Marek, GJ	1
Cooper, AJ; Stanford, IM	1
Dun, NJ; Hwang, BH; Mizoguchi, H; Nagase, H; Narita, M; Oji, DE; Tseng, LF	1
Lohmann, AB; Welch, SP	1
Allescher, HD; Brechmann, C; Hahn, A; Schusdziarra, V; Storr, M	1
Carr, JA; Lovering, AT	1
Devi, LA; Gomes, I; Gupta, A; Jordan, BA; Nagy, V; Trapaidze, N	1
Clarke, PB; Fraser, GL; Pradhan, AA; Wahlestedt, C	1
Lunzer, MM; Portoghese, PS	1
Hempelmann, G; Hirsch, J; Menzebach, A; Welters, ID	1
Cools, AR; Hirose, N; Koshikawa, N; Murakawa, K; Nagase, H; Oi, Y; Suzuki, T; Takada, K	1
Kemppainen, H; Kiianmaa, K; Raivio, N; Suo-Yrjo, V	1
Hettiarachchi, K; Johnson, M; Liu, M; Struble, E	1

Other Studies

31 other study(ies) available for phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide and enkephalin, d-penicillamine (2,5)-

Article	Year
Inhibition of spinal opioid analgesia by supraspinal administration of selective opioid antagonists. Brain research, 1992, Nov-20, Volume: 596, Issue:1-2 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Analgesics, Opioid; Animals; Dose-Response Relationship, Drug; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalins; Injections, Intraventricular; Injections, Spinal; Male; Narcotic Antagonists; Pain Threshold; Pyrrolidines; Rats; Rats, Sprague-Dawley; Somatostatin	1992
Preliminary ligand binding data for subtypes of the delta opioid receptor in rat brain membranes. Life sciences, 1991, Volume: 49, Issue:18 Topics: Amino Acid Sequence; Animals; Binding Sites; Brain; Cell Membrane; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine-2-Alanine; Enkephalins; Kinetics; Molecular Sequence Data; Oligopeptides; Radioligand Assay; Rats; Receptors, Opioid; Receptors, Opioid, delta; Somatostatin	1991
Characterisation of opioid binding sites using selective antagonists. Progress in clinical and biological research, 1990, Volume: 328 Topics: Animals; Binding, Competitive; Brain; Diprenorphine; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Guinea Pigs; In Vitro Techniques; Indoles; Morphinans; Naltrexone; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin	1990
Involvement of central mu and delta opioid receptors in mediating the reinforcing effects of beta-endorphin in the rat. European journal of pharmacology, 1990, Jan-03, Volume: 175, Issue:1 Topics: Amino Acid Sequence; Animals; beta-Endorphin; Conditioning, Operant; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalins; Male; Molecular Sequence Data; Narcotic Antagonists; Rats; Rats, Inbred Strains; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, mu; Reinforcement, Psychology; Somatostatin	1990
Different types of opioid receptors mediating analgesia induced by morphine, DAMGO, DPDPE, DADLE and beta-endorphin in mice. Naunyn-Schmiedeberg's archives of pharmacology, 1990, Volume: 342, Issue:1 Topics: Analgesia; Animals; beta-Endorphin; Endorphins; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalin, Leucine-2-Alanine; Enkephalins; Injections, Intraventricular; Male; Mice; Mice, Inbred ICR; Morphine; Narcotic Antagonists; Reaction Time; Receptors, Opioid; Somatostatin	1990
Identification of the opioid receptor types mediating beta-endorphin-induced alterations in dopamine release in the nucleus accumbens. European journal of pharmacology, 1990, Nov-06, Volume: 190, Issue:1-2 Topics: Analgesics; Animals; beta-Endorphin; Biogenic Monoamines; Brain Chemistry; Chromatography, High Pressure Liquid; Dialysis; Dopamine; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalins; Injections, Intraventricular; Male; Narcotic Antagonists; Nucleus Accumbens; Rats; Rats, Inbred Strains; Receptors, Opioid; Somatostatin	1990
[3H]-[H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2] ([3H]CTOP), a potent and highly selective peptide for mu opioid receptors in rat brain. The Journal of pharmacology and experimental therapeutics, 1989, Volume: 248, Issue:1 Topics: Animals; Brain; Endorphins; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; In Vitro Techniques; Kinetics; Magnesium; Male; Rats; Rats, Inbred Strains; Receptors, Opioid; Receptors, Opioid, mu; Sodium; Somatostatin; Temperature; Tritium	1989
Cyclic somatostatin octapeptide analogues with high affinity and selectivity toward mu opioid receptors. Life sciences, 1986, Jun-16, Volume: 38, Issue:24 Topics: Animals; Binding, Competitive; Brain; Cell Membrane; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Naloxone; Oligopeptides; Rats; Rats, Inbred Strains; Receptors, Cell Surface; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, mu; Receptors, Somatostatin; Somatostatin; Structure-Activity Relationship	1986
H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2: a potent and selective antagonist opioid receptors. NIDA research monograph, 1986, Volume: 75 Topics: Animals; Brain; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Kinetics; Naloxone; Rats; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin	1986
Opioid effects on spinal [3H]5-hydroxytryptamine release are not related to their antinociceptive action. European journal of pharmacology, 1995, Jan-05, Volume: 272, Issue:1 Topics: Amino Acid Sequence; Analgesics; Animals; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; In Vitro Techniques; Isotope Labeling; Male; Molecular Sequence Data; Naltrexone; Narcotics; Potassium; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Serotonin; Somatostatin; Spinal Cord; Synaptic Transmission; Synaptosomes	1995
A lack of supersensitivity to opioid receptor agonists following chronic spinal opioid receptor antagonist administration in the rat. General pharmacology, 1995, Volume: 26, Issue:1 Topics: Animals; Dose-Response Relationship, Drug; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Male; Naltrexone; Narcotic Antagonists; Rats; Rats, Sprague-Dawley; Receptors, Opioid; Somatostatin; Species Specificity; Spinal Cord	1995
Evidence that nor-binaltorphimine can function as an antagonist at multiple opioid receptor subtypes. European journal of pharmacology, 1994, Oct-24, Volume: 264, Issue:2 Topics: Amino Acid Sequence; Analgesics; Animals; Benzeneacetamides; Drug Interactions; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalins; Injections, Intraventricular; Male; Molecular Sequence Data; Naltrexone; Narcotic Antagonists; Pain; Pain Threshold; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, Opioid, kappa; Somatostatin	1994
Differential regulation of adenylyl cyclase activity by mu and delta opioids in rat caudate putamen and nucleus accumbens. The Journal of pharmacology and experimental therapeutics, 1993, Volume: 267, Issue:1 Topics: Adenylyl Cyclases; Amino Acid Sequence; Animals; Benzeneacetamides; Caudate Nucleus; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalins; Male; Molecular Sequence Data; Naloxone; Naltrexone; Nucleus Accumbens; Oligopeptides; Putamen; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Signal Transduction; Somatostatin	1993
Opioid actions on rat anterior cingulate cortex neurons in vitro. The Journal of neuroscience : the official journal of the Society for Neuroscience, 1994, Volume: 14, Issue:3 Pt 1 Topics: Animals; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Methionine; Enkephalins; Glutamates; Glutamic Acid; Gyrus Cinguli; Naloxone; Narcotic Antagonists; Narcotics; Neurons; Neurotransmitter Agents; Rats; Receptors, Opioid; Somatostatin; Synapses; Synaptic Transmission	1994
Go mediates the coupling of the mu opioid receptor to adenylyl cyclase in cloned neural cells and brain. Proceedings of the National Academy of Sciences of the United States of America, 1993, May-01, Volume: 90, Issue:9 Topics: Adenylate Cyclase Toxin; Adenylyl Cyclases; Analgesics; Animals; Antibodies; Cell Membrane; Clone Cells; Corpus Striatum; Cyclic AMP; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; GTP-Binding Proteins; Humans; Kinetics; Membrane Proteins; Neuroblastoma; Pertussis Toxin; Rats; Receptors, Opioid, mu; Somatostatin; Tumor Cells, Cultured; Virulence Factors, Bordetella	1993
Opioid actions on neurons of rat lateral amygdala in vitro. Brain research, 1993, May-28, Volume: 612, Issue:1-2 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Amino Acid Sequence; Amino Acids; Amygdala; Analgesics; Animals; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalin, Methionine; Enkephalins; GABA-A Receptor Antagonists; In Vitro Techniques; Molecular Sequence Data; Naloxone; Narcotic Antagonists; Narcotics; Neurons; Pyrrolidines; Rats; Somatostatin; Synapses	1993
Role of opioid receptors in the spinal antinociceptive effects of neuropeptide FF analogues. British journal of pharmacology, 1996, Volume: 117, Issue:3 Topics: Amino Acid Sequence; Analgesics; Analgesics, Opioid; Animals; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Injections, Spinal; Male; Molecular Sequence Data; Morphine; Naltrexone; Narcotic Antagonists; Oligopeptides; Pain Measurement; Rats; Rats, Sprague-Dawley; Receptors, Opioid; Somatostatin; Spinal Cord	1996
Structure-activity relationship of biphalin. The synthesis and biological activities of new analogues with modifications in positions 3 and 4. Life sciences, 1997, Volume: 60, Issue:15 Topics: Analgesics; Animals; Brain; Dose-Response Relationship, Drug; Enkephalin, D-Penicillamine (2,5)-; Enkephalins; Guinea Pigs; Ileum; Male; Mice; Mice, Inbred ICR; Muscle Contraction; Muscle, Smooth; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin; Structure-Activity Relationship; Vas Deferens	1997
5-Hydroxytryptamine-induced excitatory postsynaptic currents in neocortical layer V pyramidal cells: suppression by mu-opiate receptor activation. Neuroscience, 1998, Volume: 86, Issue:2 Topics: alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Animals; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Methionine; Enkephalins; Evoked Potentials; Excitatory Postsynaptic Potentials; In Vitro Techniques; Male; Models, Neurological; Neocortex; Pyramidal Cells; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Serotonin, 5-HT2A; Receptors, Opioid, mu; Receptors, Serotonin; Serotonin; Somatostatin; Synapses	1998
Presynaptic mu and delta opioid receptor modulation of GABAA IPSCs in the rat globus pallidus in vitro. The Journal of neuroscience : the official journal of the Society for Neuroscience, 1999, Jun-15, Volume: 19, Issue:12 Topics: 2-Amino-5-phosphonovalerate; 6-Cyano-7-nitroquinoxaline-2,3-dione; Analgesics; Analgesics, Opioid; Animals; Bicuculline; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Methionine; Enkephalins; Excitatory Amino Acid Antagonists; GABA Antagonists; Globus Pallidus; In Vitro Techniques; Male; Membrane Potentials; Neostriatum; Neurons; Patch-Clamp Techniques; Presynaptic Terminals; Rats; Rats, Wistar; Receptors, GABA-A; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin; Synaptic Transmission; Tetrodotoxin	1999
Identification of the G-protein-coupled ORL1 receptor in the mouse spinal cord by [35S]-GTPgammaS binding and immunohistochemistry. British journal of pharmacology, 1999, Volume: 128, Issue:6 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Animals; Atropine; Autoradiography; Baclofen; Binding, Competitive; Dose-Response Relationship, Drug; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; GTP-Binding Proteins; Guanosine 5'-O-(3-Thiotriphosphate); Guanosine Diphosphate; Haloperidol; Immunohistochemistry; In Vitro Techniques; Male; Membranes; Mice; Mice, Inbred ICR; Naltrexone; Narcotic Antagonists; Nociceptin; Nociceptin Receptor; Opioid Peptides; Peptide Fragments; Propranolol; Receptors, Opioid; Somatostatin; Spinal Cord; Sulfur Radioisotopes; Yohimbine	1999
ATP-gated K(+) channel openers enhance opioid antinociception: indirect evidence for the release of endogenous opioid peptides. European journal of pharmacology, 1999, Dec-03, Volume: 385, Issue:2-3 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Adenosine Triphosphate; Analgesics; Animals; Cromakalim; Diazoxide; Dose-Response Relationship, Drug; Drug Interactions; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Glyburide; Injections, Intraventricular; Ion Channel Gating; Male; Mice; Mice, Inbred ICR; Morphine; Naltrexone; Narcotic Antagonists; Nociceptors; Opioid Peptides; Pain; Potassium Channels; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Somatostatin	1999
Modulatory effect of endogenous and exogenous opioids on the excitatory reflex pathway of the rat ileum. Neuropeptides, 2000, Volume: 34, Issue:1 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Animals; Endorphins; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Enkephalin, Methionine; Ileum; In Vitro Techniques; Male; Morphine; Muscle, Smooth; Naltrexone; Narcotic Antagonists; Narcotics; Peristalsis; Rats; Rats, Wistar; Receptors, Opioid; Somatostatin	2000
Mu and delta opioid receptor regulation of pro-opiomelanocortin peptide secretion from the rat neurointermediate pituitary in vitro. Neuropeptides, 2000, Volume: 34, Issue:1 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; alpha-MSH; Analgesics, Opioid; Animals; beta-Endorphin; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; In Vitro Techniques; Male; Oligopeptides; Opioid Peptides; Pituitary Gland; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin	2000
Heterodimerization of mu and delta opioid receptors: A role in opiate synergy. The Journal of neuroscience : the official journal of the Society for Neuroscience, 2000, Nov-15, Volume: 20, Issue:22 Topics: Analgesics, Opioid; Animals; Cell Line; CHO Cells; Cricetinae; Detergents; Dimerization; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Humans; Ligands; Mice; Narcotic Antagonists; Oligopeptides; Precipitin Tests; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin	2000
Supraspinal antinociceptive response to [D-Pen(2,5)]-enkephalin (DPDPE) is pharmacologically distinct from that to other delta-agonists in the rat. The Journal of pharmacology and experimental therapeutics, 2000, Volume: 295, Issue:3 Topics: Analgesics, Opioid; Animals; Dose-Response Relationship, Drug; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Male; Oligonucleotides, Antisense; Oligopeptides; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Somatostatin; Spinal Cord	2000
Identity of the putative delta1-opioid receptor as a delta-kappa heteromer in the mouse spinal cord. European journal of pharmacology, 2003, Apr-25, Volume: 467, Issue:1-3 Topics: Animals; Benzylidene Compounds; Dynorphins; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Immune Sera; Mice; Naltrexone; Oligopeptides; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Somatostatin; Spinal Cord	2003
Effects of endogenous and synthetic opioid peptides on neutrophil function in vitro. British journal of anaesthesia, 2003, Volume: 91, Issue:4 Topics: Antigens, CD; beta-Endorphin; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine-2-Alanine; Enkephalin, Methionine; Flow Cytometry; Humans; Male; Neutrophil Activation; Neutrophils; Opioid Peptides; Peptide Fragments; Somatostatin; Superoxides	2003
Interactions among mu- and delta-opioid receptors, especially putative delta1- and delta2-opioid receptors, promote dopamine release in the nucleus accumbens. Neuroscience, 2005, Volume: 135, Issue:1 Topics: Analgesics, Opioid; Anesthetics, Local; Animals; Benzylidene Compounds; Dopamine; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Enkephalin, Leucine; Extracellular Space; Male; Microdialysis; Naloxone; Naltrexone; Narcotic Antagonists; Nucleus Accumbens; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, mu; Somatostatin; Tetrodotoxin	2005
Opioidergic modulation of ethanol self-administration in the ventral pallidum. Alcoholism, clinical and experimental research, 2012, Volume: 36, Issue:2 Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Alcohol Drinking; Analgesics, Opioid; Animals; Dose-Response Relationship, Drug; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalin, D-Penicillamine (2,5)-; Globus Pallidus; Male; Microinjections; Morphine; Motor Activity; Naltrexone; Narcotic Antagonists; Rats; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, kappa; Receptors, Opioid, mu; Self Administration; Somatostatin	2012
Characterization of cyclic peptides containing disulfide bonds. Journal of pharmaceutical and biomedical analysis, 2015, May-10, Volume: 109 Topics: Acetic Acid; Chromatography, High Pressure Liquid; Disulfides; Dithiothreitol; Enkephalin, D-Penicillamine (2,5)-; Indicators and Reagents; Magnetic Resonance Spectroscopy; Peptides, Cyclic; Somatostatin; Tandem Mass Spectrometry; Trifluoroacetic Acid	2015