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Illuminati D, Trapella C, Zanirato V, Guerrini R, Albanese V, Sturaro C, Stragapede S, Malfacini D, Compagnin G, Catani M, Fantinati A. (L)-Monomethyl Tyrosine (Mmt): New Synthetic Strategy via Bulky 'Forced-Traceless' Regioselective Pd-Catalyzed C(sp 2)-H Activation. Pharmaceuticals (Basel) 2023; 16:1592. [PMID: 38004457 PMCID: PMC10675785 DOI: 10.3390/ph16111592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
The enormous influence in terms of bioactivity, affinity, and selectivity represented by the replacement of (L)-2,6-dimethyl tyrosine (Dmt) instead of Phenylalanine (Phe) into Nociceptin/orphanin (N/OFQ) neuropeptide analogues has been well documented in the literature. More recently, the non-natural amino acid (L)-2-methyl tyrosine (Mmt), with steric hindrance included between Tyr and Dmt, has been studied because of the modulation of steric effects in opioid peptide chains. Here, we report a new synthetic strategy to obtain Mmt based on the well-known Pd-catalyzed ortho-C(sp2)-H activation approach, because there is a paucity of other synthetic routes in the literature to achieve it. The aim of this work was to force only the mono-ortho-methylation process over the double ortho-methylation one. In this regard, we are pleased to report that the introduction of the dibenzylamine moiety on a Tyr aromatic nucleus is a convenient and traceless solution to achieve such a goal. Interestingly, our method provided the aimed Mmt either as N-Boc or N-Fmoc derivatives ready to be inserted into peptide chains through solid-phase peptide synthesis (SPPS). Importantly, the introduction of Mmt in place of Phe1 in the sequence of N/OFQ(1-13)-NH2 was very well tolerated in terms of pharmacological profile and bioactivity.
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Affiliation(s)
- Davide Illuminati
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 213/d, 41125 Modena, Italy;
| | - Claudio Trapella
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy; (C.T.); (V.Z.); (R.G.); (G.C.); (M.C.)
| | - Vinicio Zanirato
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy; (C.T.); (V.Z.); (R.G.); (G.C.); (M.C.)
| | - Remo Guerrini
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy; (C.T.); (V.Z.); (R.G.); (G.C.); (M.C.)
| | - Valentina Albanese
- Department of Environmental and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy;
| | - Chiara Sturaro
- U.O. Neurological Clinic, University Hospital of Ferrara, Via Aldo Moro, 8, 44124 Ferrara, Italy; (C.S.)
| | - Simona Stragapede
- U.O. Neurological Clinic, University Hospital of Ferrara, Via Aldo Moro, 8, 44124 Ferrara, Italy; (C.S.)
| | - Davide Malfacini
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via 8 Febbraio, 2, 35131 Padova, Italy;
| | - Greta Compagnin
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy; (C.T.); (V.Z.); (R.G.); (G.C.); (M.C.)
| | - Martina Catani
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy; (C.T.); (V.Z.); (R.G.); (G.C.); (M.C.)
| | - Anna Fantinati
- Department of Environmental and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy;
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Illuminati D, Fantinati A, De Ventura T, Perrone D, Sturaro C, Albanese V, Marzola E, Cristofori V, Oble J, Poli G, Trapella C. Synthesis of 2,6-Dimethyltyrosine-Like Amino Acids through Pinacolinamide-Enabled C-H Dimethylation of 4-Dibenzylamino Phenylalanine. J Org Chem 2022; 87:2580-2589. [PMID: 35138099 DOI: 10.1021/acs.joc.1c02527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of a small library of NH-Boc- or NH-Fmoc-protected l-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been achieved. The approach, which took advantage of a Pd-catalyzed directed C-H dimethylation of picolinamide derivatives, allowed the electronic and steric properties of the resulting amino acid derivatives to be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.
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Affiliation(s)
- Davide Illuminati
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy.,Faculté des Sciences et Ingénierie, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Anna Fantinati
- Department of Environmental and Prevention Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Tiziano De Ventura
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Daniela Perrone
- Department of Environmental and Prevention Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Chiara Sturaro
- Department of Neuroscience and Rehabilitation, Section of Pharmacology, University of Ferrara, Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Valentina Albanese
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Erika Marzola
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Virginia Cristofori
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Julie Oble
- Faculté des Sciences et Ingénierie, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Giovanni Poli
- Faculté des Sciences et Ingénierie, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Claudio Trapella
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
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Bender AM, Griggs NW, Gao C, Trask TJ, Traynor JR, Mosberg HI. Rapid Synthesis of Boc-2',6'-dimethyl-l-tyrosine and Derivatives and Incorporation into Opioid Peptidomimetics. ACS Med Chem Lett 2015; 6:1199-203. [PMID: 26713104 DOI: 10.1021/acsmedchemlett.5b00344] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/19/2015] [Indexed: 12/30/2022] Open
Abstract
The unnatural amino acid 2',6'-dimethyl-l-tyrosine has found widespread use in the development of synthetic opioid ligands. Opioids featuring this residue at the N-terminus often display superior potency at one or more of the opioid receptor types, but the availability of the compound is hampered by its cost and difficult synthesis. We report here a short, three-step synthesis of Boc-2',6'-dimethyl-l-tyrosine (3a) utilizing a microwave-assisted Negishi coupling for the key carbon-carbon bond forming step, and employ this chemistry for the expedient synthesis of other unnatural tyrosine derivatives. Three of these derivatives (3c, 3d, 3f) have not previously been examined as Tyr(1) replacements in opioid ligands. We describe the incorporation of these tyrosine derivatives in a series of opioid peptidomimetics employing our previously reported tetrahydroquinoline (THQ) scaffold, and the binding and relative efficacy of each of the analogues at the three opioid receptor subtypes: mu (MOR), delta (DOR), and kappa (KOR).
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Affiliation(s)
- Aaron M. Bender
- Interdepartmental
Program in Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nicholas W. Griggs
- Department
of Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Chao Gao
- Department
of Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tyler J. Trask
- Department
of Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John R. Traynor
- Department
of Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Henry I. Mosberg
- Interdepartmental
Program in Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department
of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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2',6'-dimethylphenylalanine: a useful aromatic amino Acid surrogate for tyr or phe residue in opioid peptides. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2012; 2012:498901. [PMID: 25954528 PMCID: PMC4412257 DOI: 10.1155/2012/498901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/15/2012] [Accepted: 03/18/2012] [Indexed: 11/17/2022]
Abstract
Two aromatic amino acids, Tyr(1) and Phe(3) or Phe(4), are important structural elements in opioid peptides because they interact with opioid receptors. The usefulness of an artificial amino acid residue 2',6'-dimethylphenylalanine (Dmp) was investigated as an aromatic amino acid surrogate for several opioid peptides, including enkephalin, dermorphin, deltorphin, endomorphin, dynorphin A, and nociceptin peptides. In most peptides, substitutions of Phe(3) by a Dmp residue produced analogs with improved receptor-binding affinity and selectivity, while the same substitution of Phe(4) induced markedly reduced receptor affinity and selectivity. Interestingly, replacement of Tyr(1) by Dmp produced analogs with unexpectedly high affinity or produced only a slight drop in receptor affinity and bioactivity for most peptides. Thus, Dmp is also a useful surrogate for the N-terminal Tyr residue in opioid peptides despite the lack of a phenolic hydroxyl group, which is considered necessary for opioid activity. The Dmp(1)-substituted analogs are superior to 2',6'-dimethyltyrosine (Dmt)(1)-substituted analogs for high receptor selectivity since the latter generally have poor receptor selectivity. Thus, Dmp is very useful as an aromatic amino acid surrogate in opioid peptides and may be useful for developing other novel peptide mimetics with high receptor specificity.
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Li T, Shiotani K, Miyazaki A, Tsuda Y, Ambo A, Sasaki Y, Jinsmaa Y, Marczak E, Bryant SD, Lazarus LH, Okada Y. Bifunctional [2',6'-dimethyl-L-tyrosine1]endomorphin-2 analogues substituted at position 3 with alkylated phenylalanine derivatives yield potent mixed mu-agonist/delta-antagonist and dual mu-agonist/delta-agonist opioid ligands. J Med Chem 2007; 50:2753-66. [PMID: 17497839 PMCID: PMC2669435 DOI: 10.1021/jm061238m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Endomorphin-2 (H-Tyr-Pro-Phe-Phe-NH2) and [Dmt1]EM-2 (Dmt = 2',6'-dimethyl-l-tyrosine) analogues, containing alkylated Phe3 derivatives, 2'-monomethyl (2, 2'), 3',5'- and 2',6'-dimethyl (3, 3', and 4', respectively), 2',4',6'-trimethyl (6, 6'), 2'-ethyl-6'-methyl (7, 7'), and 2'-isopropyl-6'-methyl (8, 8') groups or Dmt (5, 5'), had the following characteristics: (i) [Xaa3]EM-2 analogues exhibited improved mu- and delta-opioid receptor affinities. The latter, however, were inconsequential (Kidelta = 491-3451 nM). (ii) [Dmt1,Xaa3]EM-2 analogues enhanced mu- and delta-opioid receptor affinities (Kimu = 0.069-0.32 nM; Kidelta = 1.83-99.8 nM) without kappa-opioid receptor interaction. (iii) There were elevated mu-bioactivity (IC50 = 0.12-14.4 nM) and abolished delta-agonism (IC50 > 10 muM in 2', 3', 4', 5', 6'), although 4' and 6' demonstrated a potent mixed mu-agonism/delta-antagonism (for 4', IC50mu = 0.12 and pA2 = 8.15; for 6', IC50mu = 0.21 nM and pA2 = 9.05) and 7' was a dual mu-agonist/delta-agonist (IC50mu = 0.17 nM; IC50delta = 0.51 nM).
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MESH Headings
- Animals
- Binding, Competitive
- Brain/metabolism
- Guinea Pigs
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Muscle, Smooth/physiology
- Myenteric Plexus/physiology
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/physiology
- Oligopeptides/chemical synthesis
- Oligopeptides/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, mu/agonists
- Structure-Activity Relationship
- Synaptosomes/metabolism
- Tyrosine/analogs & derivatives
- Tyrosine/chemical synthesis
- Tyrosine/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Kimitaka Shiotani
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Anna Miyazaki
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Yuko Tsuda
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Akihiro Ambo
- Department of Biochemistry, Tohoku Pharmaceutical University, Aoba-ku, Sendai 981-8558, Japan
| | - Yusuke Sasaki
- Department of Biochemistry, Tohoku Pharmaceutical University, Aoba-ku, Sendai 981-8558, Japan
| | - Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Ewa Marczak
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Sharon D. Bryant
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Lawrence H. Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
- Corresponding authors: Y. Okada: Tel: +81-78-974-1551, fax: +81-78-974-5689., E-mail: . L. H. Lazarus: Tel: +1-919-541-3238, fax: + 1-919-541-5737. E-mail:
| | - Yoshio Okada
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Corresponding authors: Y. Okada: Tel: +81-78-974-1551, fax: +81-78-974-5689., E-mail: . L. H. Lazarus: Tel: +1-919-541-3238, fax: + 1-919-541-5737. E-mail:
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6
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Gao Y, Liu X, Liu W, Qi Y, Liu X, Zhou Y, Wang R. Opioid receptor binding and antinociceptive activity of the analogues of endomorphin-2 and morphiceptin with phenylalanine mimics in the position 3 or 4. Bioorg Med Chem Lett 2006; 16:3688-92. [PMID: 16682191 DOI: 10.1016/j.bmcl.2006.04.063] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 04/06/2006] [Accepted: 04/21/2006] [Indexed: 11/29/2022]
Abstract
Endomorphin-2 (EM-2) and morphiceptin are the same class of putative mu-opioid receptor ligands. To investigate the effectiveness of phenylglycine (Phg, L or D) and homophenylalanine (Hfe) as the surrogates of phenylalanine in the position 3 and/or 4 of them, a series of their analogues were synthesized. Opioid receptor binding affinities were determined. Two analogues, [Hfe3]EM-2 and [Phg4] (EM-2/morphiceptin), showed different but potent antinociceptive activity in mouse hot-plate test, the results combined with their half-lives of degradation by mouse brain homogenate could also present some evidence to the in vivo degradative mechanism of EM-2.
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Affiliation(s)
- Yanfeng Gao
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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Sasaki Y, Kawano S, Kohara H, Watanabe H, Ambo A. ORL1 and opioid receptor preferences of nociceptin and dynorphin A analogues with Dmp substituted for N-terminal aromatic residues. Bioorg Med Chem 2006; 14:2433-7. [PMID: 16321540 DOI: 10.1016/j.bmc.2005.11.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 11/10/2005] [Accepted: 11/11/2005] [Indexed: 11/19/2022]
Abstract
Nociceptin (NOC) and dynorphin A (DYN) analogues containing 2',6'-dimethylphenylalanine (Dmp) in place of Phe or Tyr in position 1 and/or 4 were synthesized and their metabolic stability and receptor-binding properties were investigated. [Dmp1]NOC(1-13)-NH2 (1) possessed high ORL1 receptor affinity comparable to that of the parent peptide with substantially improved affinities for kappa-, mu-, and delta-opioid receptors. However, Dmp4 substitution of NOC peptide (2) reduced ORL1 receptor affinity. [Dmp1]DYN(1-13)-NH2 (4) and its Dmp4 analogue (5) possessed a 3-fold greater kappa-opioid receptor affinity and improved kappa-receptor selectivity compared to the parent peptide. Analogue 4 however exhibited an unexpectedly low in vitro bioactivity (GPI assay), suggesting, the phenolic hydroxyl group at the N-terminal residue in DYN peptide is extremely important for activation of the kappa-opioid receptor. Analogue 5 possessed an improved kappa-opioid receptor selectivity with an IC50 ratio of 1(kappa)/509(mu)/211598(delta); thus, this peptide may serve as a highly selective kappa-receptor agonist for pharmacological study. Dmp1 substitution in both the NOC and DYN peptides improved metabolic stability toward these peptides, while Dmp4 substitution provided no additional metabolic stability.
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Affiliation(s)
- Yusuke Sasaki
- Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-ku, Sendai 981-8558, Japan.
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8
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Fichna J, Gach K, Piestrzeniewicz M, Burgeon E, Poels J, Broeck JV, Janecka A. Functional Characterization of Opioid Receptor Ligands by Aequorin Luminescence-Based Calcium Assay. J Pharmacol Exp Ther 2006; 317:1150-4. [PMID: 16497786 DOI: 10.1124/jpet.105.099986] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A functional assay, based on aequorin-derived luminescence triggered by receptor-mediated changes in intracellular calcium levels, was used to examine relative potency and efficacy of the mu-opioid agonists endomorphin-1, endomorphin-2, morphiceptin, and their position 3-substituted analogs, as well as the delta-agonist deltorphin-II. The results of the aequorin assay, performed on recombinant cell lines, were compared with those obtained in the functional assay on isolated tissue preparations (guinea pig ileum and mouse vas deferens). A range of nine opioid peptide ligands produced a similar rank order of potency for the mu- and delta-opioid receptor agonists in both functional assays. The highest potency at the mu-receptor was observed for endomorphin-1, endomorphin-2, and [D-1-Nal3]morphiceptin, whereas deltorphin-II was the most potent delta-receptor agonist. In the aequorin assay, the mu- and delta-agonist-triggered luminescence was inhibited by the opioid antagonists naloxone and naltrindole, respectively. We can conclude that the use of the aequorin assay for new mu- and delta-receptor-selective opioid analogs gives pharmacologically relevant data and allows high-throughput compound screening, which does not involve radioactivity or animal tissues. This is the first study that validates the application of this assay in the screening of opioid analogs.
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Affiliation(s)
- Jakub Fichna
- Laboratory of Biomolecular Chemistry, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland
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Li T, Tsuda Y, Minoura K, In Y, Ishida T, Lazarus LH, Okada Y. Enantioselective Synthesis of a Phenylalanine Library Containing Alkyl Groups on the Aromatic Moiety: Confirmation of Stereostructure by X-Ray Analysis. Chem Pharm Bull (Tokyo) 2006; 54:873-7. [PMID: 16755061 DOI: 10.1248/cpb.54.873] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Six phenylalanine analogues containing 2'-methyl-, 2',6'-dimethyl-, 2'-ethyl-6'-methyl-, 2'-isopropyl-6'-methyl-, 2',4',6'-trimethyl-, and 3',5'-dimethyl-L-phenylalanine were synthesized enantioselectively through asymmetric hydrogenation of acetamidoacrylate derivatives. Enzymatic digestion and X-ray analysis supported the L-configuration of the phenylalanine derivatives obtained.
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences and Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 651-2180, Japan
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Abstract
This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, USA.
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Takahata H, Ouchi H, Kumagai M, Sakurada S. Asymmetric Synthesis of All Six Regioisomers of N-Boc-dimethyl-phenylalanines. HETEROCYCLES 2004. [DOI: 10.3987/com-04-s(p)41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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