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Sjuvarsson E, Marquez VE, Eriksson S. Selective Phosphorylation of South and North-Cytidine and Adenosine Methanocarba-Nucleosides by Human Nucleoside and Nucleotide Kinases Correlates with Their Growth Inhibitory Effects on Cultured Cells. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2016; 34:544-64. [PMID: 26167664 DOI: 10.1080/15257770.2015.1031248] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here bicyclo[3.1.0]hexane locked deoxycytidine (S-MCdC, N-MCdC), and deoxyadenosine analogs (S-MCdA and N-MCdA) were examined as substrates for purified preparations of human deoxynucleoside kinases: dCK, dGK, TK2, TK1, the ribonucleoside kinase UCK2, two NMP kinases (CMPK1, TMPK) and a NDP kinase. dCK can be important for the first step of phosphorylation of S-MCdC in cells, but S-MCdCMP was not a substrate for CMPK1, TMPK, or NDPK. dCK and dGK had a preference for the S-MCdA whereas N-MCdA was not a substrate for dCK, TK1, UCK2, TK2, dGK nucleoside kinases. The cell growth experiments suggested that N-MCdC and S-MCdA could be activated in cells by cellular kinases so that a triphosphate metabolite was formed. List of abbreviations: ddC, 2', 3'-didioxycytosine, Zalcitabine; 3TC, β-L-(-)-2',3'-dideoxy-3'-thiacytidine, Lamivudine; CdA, 2-cloro-2'-deoxyadenosine, Cladribine; AraA, 9-β-D-arabinofuranosyladenine; hCNT 1-3, human Concentrative Nucleoside Transporter type 1, 2 and 3; hENT 1-4, human Equilibrative Nucleoside Transporter type 1, 2, 3, and 4.
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Affiliation(s)
- Elena Sjuvarsson
- a Department of Anatomy, Physiology, and Biochemistry, Swedish University of Agricultural Sciences , VHC , Uppsala , Sweden
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2
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Effects of substitutions at the 4' and 2 positions on the bioactivity of 4'-ethynyl-2-fluoro-2'-deoxyadenosine. Antimicrob Agents Chemother 2013; 57:6254-64. [PMID: 24100493 DOI: 10.1128/aac.01703-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) form the backbone of most anti-HIV therapies. We have shown that 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a highly effective NRTI; however, the reasons for the potent antiviral activity of EFdA are not well understood. Here, we use a combination of structural, computational, and biochemical approaches to examine how substitutions in the sugar or adenine rings affect the incorporation of dA-based NRTIs like EFdA into DNA by HIV RT and their susceptibility to deamination by adenosine deaminase (ADA). Nuclear magnetic resonance (NMR) spectroscopy studies of 4'-substituted NRTIs show that ethynyl or cyano groups stabilize the sugar ring in the C-2'-exo/C-3'-endo (north) conformation. Steady-state kinetic analysis of the incorporation of 4'-substituted NRTIs by RT reveals a correlation between the north conformation of the NRTI sugar ring and efficiency of incorporation into the nascent DNA strand. Structural analysis and the kinetics of deamination by ADA demonstrate that 4'-ethynyl and cyano substitutions decrease the susceptibility of adenosine-based compounds to ADA through steric interactions at the active site. However, the major determinant for decreased susceptibility to ADA is the 2-halo substitution, which alters the pKa of N1 on the adenine base. These results provide insight into how NRTI structural attributes affect their antiviral activities through their interactions with the RT and ADA active sites.
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3
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Ketkar A, Zafar MK, Banerjee S, Marquez VE, Egli M, Eoff RL. A nucleotide-analogue-induced gain of function corrects the error-prone nature of human DNA polymerase iota. J Am Chem Soc 2012; 134:10698-705. [PMID: 22632140 DOI: 10.1021/ja304176q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Y-family DNA polymerases participate in replication stress and DNA damage tolerance mechanisms. The properties that allow these enzymes to copy past bulky adducts or distorted template DNA can result in a greater propensity for them to make mistakes. Of the four human Y-family members, human DNA polymerase iota (hpol ι) is the most error-prone. In the current study, we elucidate the molecular basis for improving the fidelity of hpol ι through use of the fixed-conformation nucleotide North-methanocarba-2'-deoxyadenosine triphosphate (N-MC-dATP). Three crystal structures were solved of hpol ι in complex with DNA containing a template 2'-deoxythymidine (dT) paired with an incoming dNTP or modified nucleotide triphosphate. The ternary complex of hpol ι inserting N-MC-dATP opposite dT reveals that the adenine ring is stabilized in the anti orientation about the pseudo-glycosyl torsion angle, which mimics precisely the mutagenic arrangement of dGTP:dT normally preferred by hpol ι. The stabilized anti conformation occurs without notable contacts from the protein but likely results from constraints imposed by the bicyclo[3.1.0]hexane scaffold of the modified nucleotide. Unmodified dATP and South-MC-dATP each adopt syn glycosyl orientations to form Hoogsteen base pairs with dT. The Hoogsteen orientation exhibits weaker base-stacking interactions and is less catalytically favorable than anti N-MC-dATP. Thus, N-MC-dATP corrects the error-prone nature of hpol ι by preventing the Hoogsteen base-pairing mode normally observed for hpol ι-catalyzed insertion of dATP opposite dT. These results provide a previously unrecognized means of altering the efficiency and the fidelity of a human translesion DNA polymerase.
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Affiliation(s)
- Amit Ketkar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, USA
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4
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Singh R, Vince R. 2-Azabicyclo[2.2.1]hept-5-en-3-one: Chemical Profile of a Versatile Synthetic Building Block and its Impact on the Development of Therapeutics. Chem Rev 2012; 112:4642-86. [DOI: 10.1021/cr2004822] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Rohit Singh
- Center for Drug Design, Academic Health Center, University of Minnesota, 516 Delaware Street Southeast,
Minneapolis, MN 55455, United States
| | - Robert Vince
- Center for Drug Design, Academic Health Center, University of Minnesota, 516 Delaware Street Southeast,
Minneapolis, MN 55455, United States
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5
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Elhalem E, Pujol CA, Damonte EB, Rodriguez JB. Synthesis and biological evaluation of N-thia-carba-thymidine as an antiherpetic agent. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.02.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Michel BY, Strazewski P. Total syntheses of a conformationally locked North-type methanocarba puromycin analogue and a dinucleotide derivative. Chemistry 2009; 15:6244-57. [PMID: 19441002 DOI: 10.1002/chem.200802629] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An original synthetic approach for the first synthesis of an enantiopure methanocarba puromycin (3'-alpha-aminoacylamino-3'-deoxyadenosine) analogue and its cytidine dinucleotide derivative is described. Each compound is conformationally locked in a North-type pucker and exhibits both a pseudoaxial hydroxy group and a pseudoequatorial aminoacyl group. The syntheses were accomplished from D-ribose in 18 and 19 steps, respectively, with key steps being a ring-closing metathesis, a Luche reduction, a Simmons-Smith cyclopropanation, a Mitsunobu coupling, a Mattocks bromoacetylation, a regioselective and a stereoselective nucleophilic substitution, a chemoselective phosphoramidite coupling and a Staudinger-Vilarrasa coupling. Both molecules are being tested for peptidyl transfer efficiency in ribosomes for comparison with the peptidyl transfer kinetics of natural puromycin and other natural and synthetic ribosomal A site substrates.
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Affiliation(s)
- Benoît Y Michel
- UMR 5246, CNRS, Laboratoire de Synthèse de Biomolécules, Université Claude Bernard Lyon 1, Villeurbanne, Université de Lyon, 69622 Lyon, France
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7
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Joshi BV, Melman A, Mackman RL, Jacobson KA. Synthesis of ethyl (1S,2R,3S,4S,5S)-2,3-O-(isopropylidene)-4-hydroxy-bicyclo[3.1.0]hexane-carboxylate from L-ribose: a versatile chiral synthon for preparation of adenosine and P2 receptor ligands. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 27:279-91. [PMID: 18260011 DOI: 10.1080/15257770701845253] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Substitution of the ribose moiety of various nucleosides and nucleotides with the (N)-methanocarba ring system increases the potency and selectivity as ligands at certain subtypes of adenosine and P2 receptors. We have prepared a key intermediate in the synthesis of these derivatives, ethyl (1S,2R,3S,4S,5S)-2,3-O-(isopropylidene)-4-hydroxybicyclo[3.1.0]hexane-carboxylate (15), starting from L-ribose (8) as a readily available, enantiopure building block. L-ribose was converted to the corresponding 5'-iodo derivative (9), which was cleaved reductively with Zn. Improvements were made in subsequent steps corresponding to a published route to biologically important (N)-methanocarba 5'-uronamido nucleosides, and new steps were added to prepare related 5'-nucleotides.
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Affiliation(s)
- Bhalchandra V Joshi
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892-0810, USA
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8
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Aubin Y, Audran G, Monti H, De Clercq E. Chemoenzymatic synthesis and antiviral evaluation of conformationally constrained and 3′-methyl-branched carbanucleosides using both enantiomers of the same building block. Bioorg Med Chem 2008; 16:374-81. [PMID: 17905585 DOI: 10.1016/j.bmc.2007.09.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 09/10/2007] [Accepted: 09/14/2007] [Indexed: 10/22/2022]
Abstract
Starting from both enantiomers of a readily available building block, a straightforward enantioselective approach to constrained 3'-methyl-2',3'-alpha-oxirane-fused and 3'-methyl-3',4'-alpha-oxirane-fused carbanucleosides bearing different purine base analogues is described. The title compounds were evaluated as potential antiviral agents against important viruses. None of the new compounds had significant antiviral activity at a concentration of 100 microg/mL, which was the highest concentration tested.
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Affiliation(s)
- Yoann Aubin
- Laboratoire de Réactivité Organique Sélective, U.M.R. 6180 Chirotechnologies: catalyse et biocatalyse, Université Paul Cézanne, Aix-Marseille III, 13397 Marseille Cedex 20, France
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9
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Gagneron J, Gosselin G, Mathé C. Synthesis of Nucleoside Analogues Bearing the Five Naturally Occurring Nucleic Acid Bases Built on a 2-Oxabicylo[3.1.0]hexane Scaffold. J Org Chem 2005; 70:6891-7. [PMID: 16095310 DOI: 10.1021/jo051047b] [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] [Indexed: 11/29/2022]
Abstract
Hitherto unknown nucleoside analogues incorporating the five naturally occurring nucleic acid bases built on a 2-oxabicyclo[3.1.0]hexane template were synthesized. The synthesis of these new conformationally restricted nucleoside analogues involved the preparation of a suitable sugar precursor bearing the 2-oxabicyclo[3.1.0]hexane scaffold. This sugar was readily obtained from [(3aS,6aS)-2,2-dimethyl-3a,6a-dihydrofuro[2,3-d][1,3]dioxol-5-yl]methyl benzyl ether (4) following a Simons-Smith-type cyclopropanation reaction. Finally, glycosylation reactions and deprotection provided the nucleoside analogues. Using nucleoside 14 bearing thymine base as a model, we found that the conformation of such nucleoside analogue was restricted toward a (0)T(1) conformation.
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Affiliation(s)
- Julien Gagneron
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, UMR 5625 CNRS-Université Montpellier II, case courrier 008, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
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10
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Len C, Violeau B. Asymmetric synthesis of thymine nucleoside analogues based on the isochroman core. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.05.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Ataie G, Safarian S, Divsalar A, Saboury AA, Moosavi-Movahedi AA, Ranjbar B, Cristalli G, Mardanian S. Kinetic and structural analysis of the inhibition of adenosine deaminase by acetaminophen. J Enzyme Inhib Med Chem 2004; 19:71-8. [PMID: 15202496 DOI: 10.1080/14756360310001632741] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Kinetic and thermodynamic studies have been made on the effect of acetaminophen on the activity and structure of adenosine deaminase in 50 mM sodium phosphate buffer pH 7.5, at two temperatures of 27 and 37 degrees C using UV spectrophotometry, circular dichroism (CD) and fluorescence spectroscopy. Acetaminophen acts as a competitive inhibitor at 27 degrees C (Ki = 126 microM) and an uncompetitive inhibitor at 37 degrees C (Ki = 214 microM). Circular dichroism studies do not show any considerable effect on the secondary structure of adenosine deaminase by increasing the temperature from 27 to 37 degrees C. However, the secondary structure of the protein becomes more compact at 37 degrees C in the presence of acetaminophen. Fluorescence spectroscopy studies show considerable change in the tertiary structure of the protein by increasing the temperature from 27 to 37 degrees C. Also, the fluorescence spectrum of the protein incubated with different concentrations of acetaminophen show different inhibition behaviors by the effector at the two temperatures.
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Affiliation(s)
- G Ataie
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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12
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Paoli ML, Piccini S, Rodriquez M, Sega A. Sensible improvements induced by ionic liquids in the reaction of modified carbasugars with bases for the building of constrained carbanucleosides. J Org Chem 2004; 69:2881-3. [PMID: 15074946 DOI: 10.1021/jo035807z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Starting from racemic 4-hydroxy-4-methyl-2-cyclopentenone, a family of enantiopure carbanucleosides locked in the northern conformation has been synthesized. The use of ionic liquids was determinant in the last step resulting in a tangible increase of the yields and dramatic reduction of reaction times and volumes of organic solvents. To our knowledge, this is the first example of the use of ionic liquids in the coupling of carbasugars with heterocyclic bases.
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Affiliation(s)
- M Laura Paoli
- Dipartimento Farmaco-Chimico-Tecnologico, Università degli Studi di Siena, Via A. Moro, 53100 Siena, Italy
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13
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Schelling P, Claus MT, Johner R, Marquez VE, Schulz GE, Scapozza L. Biochemical and Structural Characterization of (South)-Methanocarbathymidine That Specifically Inhibits Growth of Herpes Simplex Virus Type 1 Thymidine Kinase-transduced Osteosarcoma Cells. J Biol Chem 2004; 279:32832-8. [PMID: 15163659 DOI: 10.1074/jbc.m313343200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two analogs of the natural nucleoside dT featuring a pseudosugar with fixed conformation in place of the deoxyribosyl residue (carbathymidine analogs) were biochemically and structurally characterized for their acceptance by both human cytosolic thymidine kinase isoenzyme 1 (hTK1) and herpes simplex virus type 1 thymidine kinase (HSV1 TK) and subsequently tested in cell proliferation assays. 3'-exo-Methanocarbathymidine ((South)-methanocarbathymidine (S)-MCT), which is a substrate for HSV1 TK, specifically inhibited growth of HSV1 TK-transduced human osteosarcoma cells with an IC(50) value in the range of 15 microM without significant toxicity toward both hTK1-negative (TK(-)) and non-transduced cells. 2'-exo-Methanocarbathymidine ((North)-methanocarbathymidine (N)-MCT), which is a weak substrate for hTK1 and a substantial one for HSV1 TK, induced a specific growth inhibition in HSV1 TK-transfected cells comparable to that of (S)-MCT and ganciclovir. A growth inhibition activity was also observed with (N)-MCT and ganciclovir in non-transduced cells in a cell line-dependent manner, whereas TK(-) cells were not affected. The presented 1.95-A crystal structure of the complex (S)-MCT.HSV1 TK explains both the more favorable binding affinity and catalytic turnover of (S)-MCT for HSV1 TK over the North analog. Additionally the plasticity of the active site of the enzyme is addressed by comparing the binding of (North)- and (South)-carbathymidine analogs. The presented study of these two potent candidate prodrugs for HSV1 TK gene-directed enzyme prodrug therapy suggests that (S)-MCT may be even safer to use than its North counterpart (N)-MCT.
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Affiliation(s)
- Pierre Schelling
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH), Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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14
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Marquez VE, Ben-Kasus T, Barchi JJ, Green KM, Nicklaus MC, Agbaria R. Experimental and structural evidence that herpes 1 kinase and cellular DNA polymerase(s) discriminate on the basis of sugar pucker. J Am Chem Soc 2004; 126:543-9. [PMID: 14719951 DOI: 10.1021/ja037929e] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two isomers of methanocarba (MC) thymidine (T), one an effective antiherpes agent with the pseudosugar moiety locked in the North (N) hemisphere of the pseudorotational cycle (1a, N-MCT) and the other an inactive isomer locked in the antipodean South (S) conformation (1b, S-MCT) were used to determine whether kinases and polymerases discriminate between their substrates on the basis of sugar conformation. A combined solid-state and solution conformational analysis of both compounds, coupled with the direct measurement of mono-, di-, and triphosphate levels in control cells, cells infected with the Herpes simplex virus, or cells transfected with the corresponding viral kinase gene (HSV-tk), suggests that kinases prefer substrates that adopt the S sugar conformation. On the other hand, the cellular DNA polymerase(s) of a murine tumor cell line transfected with HSV-tk incorporated almost exclusively the triphosphate of the locked N conformer (N-MCTTP), notwithstanding the presence of higher triphosphate levels of the S-conformer (S-MCTTP).
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Affiliation(s)
- Victor E Marquez
- Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, 376 Boyles St., Frederick, MD, 21702, USA.
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15
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Comin MJ, Rodriguez JB, Russ P, Marquez VE. Synthesis of conformationally locked carbocyclic nucleosides built on an oxabicyclo[3.1.0]hexane system. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(02)01528-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Quirk Dorr DR, Vince R. Synthesis and biological evaluation of endocyclic 2',3'-didehydro-2',3'-dideoxymethanocarba adenosine. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2002; 21:665-80. [PMID: 12502282 DOI: 10.1081/ncn-120015724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This is the first report describing the synthesis and conformation of methanocarba nucleosides incorporating an endo (beta-face) cyclopropyl at the 2',3' position of 2',3'-didehydro-2',3'-dideoxy carbocyclic nucleosides. These nucleoside isosteres have been shown to exist in a unique extreme eastern conformation. This prediction was confirmed by x-ray crystallography and high resolution NMR spectroscopy. As expected, the methanocarba adenosine compound was neither a substrate nor an inhibitor of adenosine deaminase. However, some of the compounds synthesized demonstrated moderate antiviral activity against HSV-1. The methanocarba adenosine and its triphosphate form were evaluated as inhibitors of HIV-1 reverse transcriptase.
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Affiliation(s)
- Danaè R Quirk Dorr
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 308 Harvard Street S. E., Minneapolis, MN 55455, USA
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17
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Yoshimura Y, Moon HR, Choi Y, Marquez VE. Enantioselective synthesis of bicyclo[3.1.0]hexane carbocyclic nucleosides via a lipase-catalyzed asymmetric acetylation. Characterization of an unusual acetal byproduct. J Org Chem 2002; 67:5938-45. [PMID: 12182625 DOI: 10.1021/jo020249u] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bicyclo[3.1.0]hexane scaffold can lock the conformation of a carbocyclic nucleoside into one of the two antipodal (north or south) conformations typical of conventional nucleosides that normally exist in a rapid, two-state equilibrium in solution. In a recent brief communication, we reported a practical method to access the requisite bicyclo[3.1.0]hexane pseudosugar for the north antipode via an intramolecular olefin-ketocarbene cycloaddition. The most attractive features of this synthesis was that a relatively complex synthon was obtained from simple and inexpensive starting materials and that the resulting racemic mixtures of purine nucleosides could be successfully resolved by adenosine deaminase (ADA) hydrolysis. In this work, we describe the development of a more general, lipase-catalyzed double-acetylation reaction, which could successfully resolve an earlier precursor, 4-(tert-butyldiphenylsilamethoxy)-1-(hydroxymethyl)bicyclo[3.1.0]hexan-2-ol [(+/-)-7], into enantiomerically pure (+)-diacetate 8 and (-)-monoacetate 9. The former diacetate was converted to the conformationally locked (north)-carbocyclic guanosine (+)-17 identical to the one obtained previously by ADA resolution. The present method represents a more general and efficient process applicable to the synthesis of all classes of (north) bicyclo[3.1.0]hexane nucleosides, including pyrimidine analogues. During the lipase-catalyzed resolution, we were able to demonstrate the presence of an unusual acetal-forming reaction that consumed small amounts of the unreactive monoacetate (-)-9. This side reaction was also enzyme-catalyzed and was triggered by the byproduct acetaldehyde generated during the reaction.
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Affiliation(s)
- Yuichi Yoshimura
- Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute-Frederick, 376 Boyles St., Frederick, Maryland 21702, USA
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18
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Bhushan RG, Vince R. Synthesis of conformationally restricted 2',3'-exo-methylene carbocyclic nucleosides built on a bicyclo[3.1.0]hexane template. Bioorg Med Chem 2002; 10:2325-33. [PMID: 11983530 DOI: 10.1016/s0968-0896(02)00063-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of 2',3'-exo-methylene carbocyclic nucleosides was synthesized as potential antiviral agents. These compounds were built on a bicyclo[3.1.0]hexane template that exhibits a rigid pseudoboat conformation and is capable of maintaining an identical conformation in solid state and in solution. The structures of the synthesized compounds were elucidated by NMR and X-ray crystallography. All the compounds were tested as anti-HIV and anti-HSV agents. The chemically synthesized 5'-triphosphate analogue of 7 was evaluated directly as a reverse transcriptase inhibitor.
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Affiliation(s)
- Rashmi Gupta Bhushan
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
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19
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20
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Choi Y, George C, Strazewski P, Marquez VE. Synthesis of a conformationally locked version of puromycin amino nucleoside. Org Lett 2002; 4:589-92. [PMID: 11843598 DOI: 10.1021/ol010288c] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A conformationally locked carbocyclic version of puromycin amino nucleoside was synthesized via Mitsunobu coupling of a 3-azido-substituted carbocyclic moiety with 6-chloropurine without interference from the azido group reacting with triphenylphosphine. The requisite 3-azido-substituted carbocyclic pseudosugar was prepared by a double inversion of configuration at C3' (nucleoside numbering) involving a nucleophilic displacement with azide.
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Affiliation(s)
- Yongseok Choi
- Laboratory of Medicinal Chemistry, Center for Cancer Research, NCI, Frederick, Maryland 21702, USA
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21
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Paquette LA, Bibart RT, Seekamp CK, Kahane AL. Spirocyclic restriction of nucleosides. Synthesis of the first exemplary syn-1-oxaspiro[4.4]nonanyl member. Org Lett 2001; 3:4039-41. [PMID: 11735579 DOI: 10.1021/ol010209x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The potential benefits associated with the spirocyclic restriction of nucleosides are summarized. Following exploration of a pi-allylpalladium route to 5'-alpha- or syn-dideoxy examples, we evaluated MOM protection of the 5'-hydroxyl as being suited to the synthesis of the first member of this new class of nucleoside mimic.
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Affiliation(s)
- L A Paquette
- Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA.
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22
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Wang P, Brank AS, Banavali NK, Nicklaus MC, Marquez VE, Christman JK, MacKerell AD. Use of Oligodeoxyribonucleotides with Conformationally Constrained Abasic Sugar Targets To Probe the Mechanism of Base Flipping byHhaI DNA (Cytosine C5)-methyltransferase. J Am Chem Soc 2000. [DOI: 10.1021/ja001989s] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Moon HR, Ford H, Marquez VE. A remarkably simple chemicoenzymatic approach to structurally complex bicyclo[3.1.0]hexane carbocyclic nucleosides. Org Lett 2000; 2:3793-6. [PMID: 11101421 DOI: 10.1021/ol000238s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Intramolecular cyclopropanation of a carbene engendered from the corresponding diazo beta-ketoester produced the desired bicyclo[3.1. 0]hexane pseudosugar. Purine nucleosides obtained via Mitsunobu coupling were resolved with adenosine deaminase. The requisite beta-ketoester was assembled in one step from ethyl acetoacetate and acrolein.
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Affiliation(s)
- H R Moon
- Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, FCRDC, Frederick, Maryland 21702-1201, USA
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Jacobson KA, Ji X, Li AH, Melman N, Siddiqui MA, Shin KJ, Marquez VE, Ravi RG. Methanocarba analogues of purine nucleosides as potent and selective adenosine receptor agonists. J Med Chem 2000; 43:2196-203. [PMID: 10841798 PMCID: PMC3471159 DOI: 10.1021/jm9905965] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adenosine receptor agonists have cardioprotective, cerebroprotective, and antiinflammatory properties. We report that a carbocyclic modification of the ribose moiety incorporating ring constraints is a general approach for the design of A(1) and A(3) receptor agonists having favorable pharmacodynamic properties. While simple carbocyclic substitution of adenosine agonists greatly diminishes potency, methanocarba-adenosine analogues have now defined the role of sugar puckering in stabilizing the active adenosine receptor-bound conformation and thereby have allowed identification of a favored isomer. In such analogues a fused cyclopropane moiety constrains the pseudosugar ring of the nucleoside to either a Northern (N) or Southern (S) conformation, as defined in the pseudorotational cycle. In binding assays at A(1), A(2A), and A(3) receptors, (N)-methanocarba-adenosine was of higher affinity than the (S)-analogue, particularly at the human A(3) receptor (N/S affinity ratio of 150). (N)-Methanocarba analogues of various N(6)-substituted adenosine derivatives, including cyclopentyl and 3-iodobenzyl, in which the parent compounds are potent agonists at either A(1) or A(3) receptors, respectively, were synthesized. The N(6)-cyclopentyl derivatives were A(1) receptor-selective and maintained high efficacy at recombinant human but not rat brain A(1) receptors, as indicated by stimulation of binding of [(35)S]GTP-gamma-S. The (N)-methanocarba-N(6)-(3-iodobenzyl)adenosine and its 2-chloro derivative had K(i) values of 4.1 and 2.2 nM at A(3) receptors, respectively, and were highly selective partial agonists. Partial agonism combined with high functional potency at A(3) receptors (EC(50) < 1 nM) may produce tissue selectivity. In conclusion, as for P2Y(1) receptors, at least three adenosine receptors favor the ribose (N)-conformation.
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Affiliation(s)
- K A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810, USA.
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Shin KJ, Moon HR, George C, Marquez VE. Construction of the bicyclo[3.1.0]hexane template of a conformationally locked carbocyclic adenosine via an olefin keto-carbene cycloaddition. J Org Chem 2000; 65:2172-8. [PMID: 10774042 DOI: 10.1021/jo9917691] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An intramolecular olefin keto-carbene cycloaddition reaction created the bicyclo[3.1.0]hexane template 10 that was necessary for the synthesis of carbocyclic amine 15. This amine is a direct precursor to a family of rigid nucleosides that are conformationally locked in the Southern hemisphere of the pseudorotational cycle. The synthesis of the conformationally locked adenosine analogue is reported herein as an illustrative example of the methodology. The racemic (South)-methanocarba adenosine analogue (+/-)-4 is the first example of a conformationally locked ribonucleoside version in the Southern hemisphere.
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Affiliation(s)
- K J Shin
- Laboratory of Medicinal Chemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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