51
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Reaction of N-Fmoc aspartic anhydride with glycosylamines: a simple entry to N-glycosyl asparagines. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.08.106] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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52
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Aldhoun M, Massi A, Dondoni A. Click azide-nitrile cycloaddition as a new ligation tool for the synthesis of tetrazole-tethered C-glycosyl alpha-amino acids. J Org Chem 2009; 73:9565-75. [PMID: 18847242 DOI: 10.1021/jo801670k] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glycoproteins play a key role in a multitude of biological events in living organisms. Hence, neoglycopeptides obtained from unnatural C-glycosyl alpha-amino acids can be used as synthetic probes in studies aiming at clarifying the role of the carbohydrate domain in glycoprotein biological activity. A new class of C-glycosyl alpha-amino acids featuring a nitrogenated heterocycle ring holding the carbohydrate and glycinyl moiety was designed in our laboratory. Having previously prepared isoxazole-, 1,2,3-triazole-, and pyridine-tethered compounds, the family has now been enlarged by a group of newcomers represented by tetrazole derivatives. Two sets of compounds have been prepared, one being constituted of C-galactosyl and C-ribosyl O-tetrazolyl serines while the other contains S-tetrazolyl cysteine derivatives. In both cases, the synthetic scheme involved a two-step route, the first one being the thermal cycloaddition of a sugar azide with p-toluensulfonyl cyanide (TsCN) to give a 1-substituted 5-sulfonyl tetrazole and the second the replacement of the tosyl group with a serine or cysteine residue. For the high efficiency and operational simplicity, the azide-TsCN cycloaddition appears to be a true click process. Finally, one of the amino acids prepared was incorporated into a tripeptide.
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Affiliation(s)
- Mohammad Aldhoun
- Dipartimento di Chimica, Laboratorio di Chimica Organica, Università di Ferrara, Via L. Borsari 46, I-44100 Ferrara, Italy
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Lee HK, Smith MD, Smith BJ, Grussendorf J, Xu L, Gillies RJ, White HS, Bulaj G. Anticonvulsant Met-enkephalin analogues containing backbone spacers reveal alternative non-opioid signaling in the brain. ACS Chem Biol 2009; 4:659-71. [PMID: 19634861 DOI: 10.1021/cb900045c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Prosthesis of non-critical parts of a polypeptide backbone is an attractive strategy to simplify bioactive peptides. This approach was applied to an opioid neuropeptide, Met-enkephalin, in which two adjacent Gly2-Gly3 residues were replaced with a series of non-peptidic backbone spacers varying in length and/or physicochemical properties. The backbone spacers did not affect the overall structural properties of the analogues, but they did dramatically reduce their affinities and agonist activities toward delta- and mu-opioid receptors. Molecular modeling suggested that the decrease of the affinity of Met-enkephalin to delta-opioid receptor could be accounted for by the loss of a single hydrogen bond. Remarkably, the analogues containing the most isostere spacers retained potent antinociceptive and anticonvulsant properties that were comparable to that of the endogenous peptide. This unexpected high in vivo potency could not be accounted for by an increase in metabolic stability. Moreover, the antiepileptic activity could not be reversed by opioid receptor antagonists. In summary, the results obtained with the analogues containing backbone spacers suggest a novel mechanism for seizure control in the brain that involves alternative non-opioid signaling.
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Affiliation(s)
| | - Misty D. Smith
- Department of Pharmacology and Toxicology, The University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, Utah 84108
| | - Brian J. Smith
- The Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
| | - Joel Grussendorf
- Department of Pharmacology and Toxicology, The University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, Utah 84108
| | - Liping Xu
- Department of Radiology
- Department of Biochemistry and Molecular Biophysics, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona 85724
| | - Robert J. Gillies
- Department of Radiology
- Department of Biochemistry and Molecular Biophysics, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona 85724
| | - H. Steve White
- Department of Pharmacology and Toxicology, The University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, Utah 84108
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Lee HK, Zhang L, Smith MD, White HS, Bulaj G. Glycosylated neurotensin analogues exhibit sub-picomolar anticonvulsant potency in a pharmacoresistant model of epilepsy. ChemMedChem 2009; 4:400-5. [PMID: 19173215 DOI: 10.1002/cmdc.200800421] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neurotensin (NT) is an endogenous neuropeptide involved in a variety of central and peripheral neuromodulatory effects. Herein we show the effects of site-specific glycosylation on the in vitro and in vivo pharmacological properties of this neuropeptide. NT analogues containing O-linked disaccharides (beta-melibiose and alpha-TF antigen) or beta-lactose units linked by a PEG(3) spacer were designed and chemically synthesized using Fmoc chemistry. For the latter analogue, Fmoc-Glu-(beta-Lac-PEG(3)-amide) was prepared. Our results indicate that the addition of the disaccharides does not negatively affect the sub-nanomolar affinity or the low-nanomolar agonist potency for the neurotensin receptor subtype 1 (NTS1). Interestingly, three glycosylated analogues exhibited sub-picomolar potency in the 6 Hz limbic seizure mouse model of pharmacoresistant epilepsy following intracerebroventricular administration. Our results suggest for the first time that chemically modified NT analogues may lead to novel antiepileptic therapies.
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Affiliation(s)
- Hee-Kyoung Lee
- Department of Medicinal Chemistry, University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, UT 84112, USA
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55
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Aldrich JV, McLaughlin JP. Peptide kappa opioid receptor ligands: potential for drug development. AAPS JOURNAL 2009; 11:312-22. [PMID: 19430912 DOI: 10.1208/s12248-009-9105-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 03/26/2009] [Indexed: 11/30/2022]
Abstract
While narcotic analgesics such as morphine, which act preferentially through mu opioid receptors, remain the gold standard in the treatment of severe pain, their use is limited by detrimental liabilities such as respiratory depression and drug dependence. Thus, there has been considerable interest in developing ligands for kappa opioid receptors (KOR) as potential analgesics and for the treatment of a variety of other disorders. These include effects mediated both by central receptors, such as antidepressant activity and a reduction in cocaine-seeking behavior, and activity resulting from the activation of peripheral receptors, such as analgesic and anti-inflammatory effects. While the vast majority of opioid receptor ligands that have progressed in preclinical development have been small molecules, significant advances have been made in recent years in identifying opioid peptide analogs that exhibit promising in vivo activity. This review will focus on possible therapeutic applications of ligands for KOR and specifically on the potential development of peptide ligands for these receptors.
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Affiliation(s)
- Jane V Aldrich
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Dr., 4050 Malott Hall, Lawrence, Kansas 66045, USA.
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56
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Koda Y, Del Borgo M, Wessling ST, Lazarus LH, Okada Y, Toth I, Blanchfield JT. Synthesis and in vitro evaluation of a library of modified endomorphin 1 peptides. Bioorg Med Chem 2008; 16:6286-96. [PMID: 18468445 DOI: 10.1016/j.bmc.2008.04.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 10/22/2022]
Abstract
Endomorphin 1 (Endo-1=Tyr-Pro-Trp-Phe-NH(2)), an endogenous opioid with high affinity and selectivity for mu-opioid receptors, mediates acute and neuropathic pain in rodents. To overcome metabolic instability and poor membrane permeability, the N- and C-termini of Endo-1 were modified by lipoamino acids (Laa) and/or sugars, and 2',6'-dimethyltyrosine (Dmt) replacement of Tyr. Analogues were assessed for mu-opioid receptor affinity, inhibition of cAMP accumulation, enzymatic stability, and permeability across Caco-2 cell monolayers. C-terminus modification decreased receptor affinity, while N-terminus C8-Laa improved stability and permeability with slight change in receptor affinity. Dmt provided a promising lead compound: [C8Laa-Dmt[1]]-Endo-1 is nine times more stable (t(1/2)=43.5min), >8-fold more permeable in Caco-2 cell monolayers, and exhibits 140-fold greater mu-opioid receptor affinity (K(imu)=0.08nM).
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Affiliation(s)
- Yasuko Koda
- School of Pharmacy, University of Queensland, St. Lucia, Brisbane, Qld 4072, Australia
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Tosi G, Costantino L, Ruozi B, Forni F, Vandelli MA. Polymeric nanoparticles for the drug delivery to the central nervous system. Expert Opin Drug Deliv 2008; 5:155-74. [DOI: 10.1517/17425247.5.2.155] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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58
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Tosi G, Costantino L, Rivasi F, Ruozi B, Leo E, Vergoni AV, Tacchi R, Bertolini A, Vandelli MA, Forni F. Targeting the central nervous system: In vivo experiments with peptide-derivatized nanoparticles loaded with Loperamide and Rhodamine-123. J Control Release 2007; 122:1-9. [PMID: 17651855 DOI: 10.1016/j.jconrel.2007.05.022] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 05/16/2007] [Accepted: 05/21/2007] [Indexed: 10/23/2022]
Abstract
Polymeric nanoparticles (Np) represent one of the most innovative non-invasive approaches for the drug delivery to the central nervous system (CNS). It is known that the ability of the Np to cross the Blood Brain Barrier (BBB), thus allowing the drugs to exert their pharmacological activity in the central nervous district, is linked to their surface characteristics. Recently it was shown that the biocompatible polyester poly(d,l-lactide-co-glycolide) (PLGA) derivatized with the peptide H(2)N-Gly-l-Phe-d-Thr-Gly-l-Phe-l-Leu-l-Ser(O-beta-d-Glucose)-CONH(2) [g7] was a useful starting material for the preparation of Np (g7-Np); moreover, fluorescent studies showed that these Np were able to cross the BBB. In this research, g-7 Np were loaded with Loperamide in order to assess their ability as drug carriers for CNS, and with Rhodamine-123, in order to qualitatively determine their biodistribution in different brain macro-areas. A pharmacological evidence is given that g7-Np are able to cross the BBB, ensuring, for the first time, a sustained release of the embedded drug, and that these Np are able to reach all the brain areas here examined. The ability to enter the CNS appears to be linked to the sequence of the peptidic moiety present on their surface.
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Affiliation(s)
- G Tosi
- Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, Modena, Italy
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Montero A, Albericio F, Royo M, Herradón B. Synthesis of a 24-Membered Cyclic Peptide-Biphenyl Hybrid. European J Org Chem 2007. [DOI: 10.1002/ejoc.200600833] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
This review describes the recent advances in the field of glycopeptide and small glycoprotein synthesis. The strategies covered include chemical and chemoenzymatic synthesis, native chemical ligation (NCL), and expressed chemical ligation. The importance of glycopeptide synthesis is exemplified by giving the reader an overview of how versatile and important these well-defined glycopeptides are as tools in glycobiology.
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Affiliation(s)
- Therese Buskas
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, USA
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Polt R, Dhanasekaran M, Keyari CM. Glycosylated Neuropeptides: A New Vista for Neuropsychopharmacology? CHEMINFORM 2005; 36. [DOI: 10.1002/chin.200550248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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