DOCSLIB.ORG

2. Artificial Nucleosides in Medicinal Chemistry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
2. Artificial Nucleosides in Medicinal Chemistry Stambasky, Jan (2008) Stereoselective synthesis of artificial C- nucleosides. PhD thesis. http://theses.gla.ac.uk/198/ Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Glasgow Theses Service http://theses.gla.ac.uk/ [email protected] A thesis submitted in part fulfilment of the requirements of the degree of Doctor of Philosophy Stereoselective Synthesis of Artificial C-Nucleosides Jan Štambaský University of Glasgow October 2007 2 Abstract Reported herein is a conceptually new synthetic route to 1’-aryl-C-ribofuranosides and their 2’,3’-didehydro-2’,3’-dideoxy (D4) analogues. We have successfully implemented a divergent synthetic route capable to reach two important, biologically significant groups of compounds. The first two strategic transformations are common for both families of target compounds (asymmetric allylic substitution, and ring-closing metathesis). D4 C-nucleoside analogues are synthesised in a three-step procedure, and 1’-aryl ribofuranoses are constructed in a four-step procedure. O Ar HO TBSO OH 233a 235b up to 46% >99% ee >99% ee >99% de + O OBoc Ar HO Ar HO OH 267 1o >99% ee up to 42% >99% ee >99% de The target compounds were prepared in an excellent enantio- and diastereopurity, in good overall yields. The yield in the synthesis of 1’-aryl-2’,3’-didehydro- 1’,2’,3’-trideoxyribofunanoses is up to 46% over all the reaction steps. The overall yield of the 1’-arylribofuranoses is up to 42%. All the strategic transformations rely on catalytic oranometallic reactions employing group 8a transition metals. All the reactions have been optimized with a view of maximal atom efficiency and environmental impact. In summary, our new methodology is perfectly suitable for the synthesis of 1’-arylribofuranoses, and their D4-analogues, bearing non-ortho-substituted aromatics and hereroaromatics, lacking coordinating (nitrogen) substituents or heteroatoms. In this point of view the most promising target application is the synthesis of lipophilic isosters of ribonucleosides for the RNA-studies. 3 Acknowledgement First of all I would like to thank my principal supervisor Prof. Pavel Kočovský. I would like to thank to my other supervisors Dr. Andrei. V. Malkov and Dr. Andrew Sutherland. Their continuous support of this project is greatly appreciated. I would like to thank Prof. Michal Hocek at the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic. His continuous interest in this project and many valuable discussions and advice regarding chemistry and general aspects of nucleosides and nucleic acids are very much appreciated. I would like to express my gratitude to the University of Glasgow, for the funding of this project. I am very grateful to Dr. Stephen N. Falling at Eastman Chemical Company, Kingsport, TN, USA. The generous gift of (R)-2-buten-1,2-diol and (S)-2-buten-1,2-diol has been very welcomed and is greatly appreciated. I am very grateful to all members of staff who have provided scientific and technical support; Dr. Andy Parkin (X-Ray), Mr. Jim Tweedie (mass spectroscopy), Mr. Ted Easdon and Mr. Alex Burns (chemistry store), Mr. William McCormack (glassblowing workshop), Mr. Stuart Mackay (IT support), Mr Jim Gall and Dr. David Adam (nuclear magnetic resonance), and Ms. Kim Wilson (microanalysis). I would like to thank all the members of our research team, present and past in the years 2004-2007: Dr. Sigitas Stončius, Dr. Filip Teplý, Dr. Angus J. P. Stewart-Liddon, Dr. Mary Margaret Westwater, Dr. Zainaba Bourhani, Dr. Marina Fruilo, Dr. John Hand, Dr. Pedro Ramírez López, Dr. Patrick Gunning, Dr. Linnea Soler, Ms. Květoslava Vranková, Mr. Kenneth MacDougall, Ms. Claire MacDonald, Ms. Louise E. Czemerys, Mr. Grant McGeoch, Mr. Mikhail Kabeshov, and Mr. Frédéric Friscourt. 4 Table of Contents Abbreviations....................................................................................................6 Preface...............................................................................................................9 1. Artificial Nucleosides in Chemical Biology ............................................10 1.1. Artificial Base-Pairs Based on Hydrogen-Bonding......................................................10 1.2. Artificial Base-Pairs Based on Hydrophobic Interactions............................................16 1.3. Artificial Base-Pairs Based on Metal Bridges..............................................................18 1.4. Artificial Base-Pairs Based on Covalent Cross-Linking...............................................20 2. Artificial Nucleosides in Medicinal Chemistry .......................................20 3. Synthetic Routes to C-Nucleosides ........................................................23 3.1. Construction of an Aglycon Unit upon a Carbohydrate Moiety....................................24 3.1.1. Introduction of the CN Group............................................................. 24 3.1.2. Wittig-Type Reaction.......................................................................... 30 3.1.3. Cycloaddition...................................................................................... 33 3.1.4. Other Methods of Construction of an Aglycon Unit........................... 39 3.2. Construction of a Carbohydrate Moiety upon an Aglycon Unit....................................42 3.3. Direct Coupling of a Carbohydrate Moiety with a Preformed Aglycon Unit .................48 3.3.1. Nucleophilic Addition to an Aldehyde Function of a Carbohydrate .. 49 3.3.2. Nucleophilic Addition to 1,2-Anhydrofuranoses ................................ 51 3.3.3. Nucleophilic Addition to Halogenoses ............................................... 52 3.3.4. Nucleophilic Addition to Furanolactones........................................... 54 3.3.5. Heck Coupling.................................................................................... 57 3.3.6. Coupling Mediated by Lewis Acids .................................................... 59 3.4. Chemical Modification of Existing C-Nucleosides.......................................................63 4. Novel Synthetic Approach to C-Nucleosides.........................................70 4.1. General Considerations..............................................................................................70 4.2. Retrosynthetic Analysis ..............................................................................................71 4.3. Metal-Catalysed Asymmetric Allylic Substitution ........................................................72 4.4. Ring-Closing Metathesis (RCM) .................................................................................77 4.5. Vicinal Dihydroxylation................................................................................................78 5. Results and Discussion ...........................................................................81 5.1. Linear Carbonates ......................................................................................................81 5.1.1. Boc Derivatization.............................................................................. 82 5.1.2. Suzuki-Miyaura Coupling................................................................... 83 5 5.1.3. Alkene Cross Metathesis..................................................................... 91 5.1.4. Horner-Wadsworth-Emmons Reaction............................................... 93 5.1.5. Conclusions......................................................................................... 94 5.2. Branched Carbonates.................................................................................................95 5.2.1. Racemic Branched Carbonates .......................................................... 95 5.2.2. Non-Racemic Branched Carbonates.................................................. 98 5.2.3. Conclusions....................................................................................... 101 5.3. Iridium-Catalysed Asymmetric Allylic Substitution (AAS)..........................................101 5.3.1. Synthesis of Protected Butenediols for AAS ..................................... 101 5.3.2. Synthesis of Ligands for AAS............................................................ 103 5.3.3. Optimization of the AAS Conditions................................................. 104 5.3.4. Conclusions....................................................................................... 114 5.4. Optimization of the Final Reaction-Sequence Steps and Completion of the Synthesis of Artificial C-Nucleosides and Their Analogues.......................................114 5.4.1. Proof of the Synthetic Concept Using Diastereoisomeric Mixtures ............................................................................................ 114 5.4.2. Synthesis of Diallylethers................................................................. 116 5.4.3. Synthesis of Artificial 2’,3’-Didehydro-2’,3’-Dideoxy- C-nucleosides ..................................................................................
Load more

Recommended publications
  • 5D57818a190bc447075641e128
    ChemComm View Article Online COMMUNICATION View Journal | View Issue Polymerase synthesis of oligonucleotides containing a Cite this: Chem. Commun., 2013, single chemically modified nucleobase for site-specific 49, 4652 redox labelling† Received 25th February 2013, Accepted 2nd April 2013 Petra Me´nova´,a Hana Cahova´,a Medard Plucnara,b Ludeˇk Havran,b bc ad DOI: 10.1039/c3cc41438h Miroslav Fojta* and Michal Hocek* www.rsc.org/chemcomm Enzymatic construction of single-nucleobase redox-labelled oligo- bioanalytical applications and that is why we report here a nucleotides was developed either based on polymerase incorpora- new general enzymatic methodology to prepare them. tion of a single modified nucleoside triphosphate (dNTP) followed The methodology was developed and tested for the synthesis by primer extension (PEX) with natural dNTPs or based on PEX of ssON probes bearing a single redox label3 – either an Creative Commons Attribution-NonCommercial 3.0 Unported Licence. with a biotinylated one-nucleotide overhang template, magneto- electroreducible 3-nitrophenyl group or electrooxidizable separation and the second PEX with a full-length template. 3-aminophenyl3b and ferrocenyl groups.3a Therefore, nitro- phenyl- (dNNO2TPs), aminophenyl- (dNNH2TPs) and ferrocenyl- Enzymatic synthesis of base-modified DNA and oligonucleo- ethynyl-modified dNTPs (dNFcTPs, Chart 1)3a,b,9 derived from tides (ONs) by polymerase incorporation of modified nucleo- all four nucleobases were tested and used as substrates for side triphosphates (dNTPs) is now an established method1 often polymerase incorporation. The modified dGXTPs were prepared used for fluorescence,2 redox,3 spin,4 barcode5 and reactive6 according to improved methods (see ESI†). Vent(exo-), Pwo and labelling, as well as for the protection of DNA.7 Primer extension KOD XL were tested as enzymes in this methodology.
    [Show full text]
  • SCNAC 2014 Program Monday, 9.6.2014 Chairman: Michal Hocek 8
    SCNAC 2014 Program Monday, 9.6.2014 Chairman: Michal Hocek 8:30 8:50 M. Hocek Opening 8:50 9:30 PL 1 H. Sugiyama Chemical Biology that Controls DNA Structure and Function: DNA Origami and Artificial Genetic Switch 9:30 9:50 OC 1 A. Taladriz Sender Synthesis and interaction studies of cationic glyco-oligoamide DNA binders 9:50 10:10 OC 2 J. W. Park Fluorescence Modification of the AAAA (4A) Loop to Probe the Structural Transition of the i-Motif 10:10 10:40 Coffee Break Chairman: Andreas Marx 10:40 11:20 PL 2 A. Ono Syntheses and characterizations of DNA duplexes having metal ion mediated base pairs 11:20 11:40 OC 3 M. Etheve-Quelquejeu Peptidyl-RNA conjugates to explore non-ribosomal peptide synthesis in bacteria. 11:40 12:00 OC 4 J. Heemstra Harnessing RNA-Small Molecule Recognition for Covalent RNA Modification 12:00 12:20 OC 5 T. Lavergne Template assembled synthetic antiparallel G-quadruplex 12:20 12:40 OC 6 G. Hayashi Metal-mediated reactions to detect 5-methylcytosine and 5-hydroxymethylcytosine in DNA 12:40 14:20 Lunch Chairman: Hiroshi Sugiyama 14:20 15:00 PL 3 H. Sleiman Three-dimensional DNA structures: design and biological applications 15:00 15:20 OC 7 J. Riedl Site-specific labeling of DNA base modifications for amplification of DNA damage 15:20 15:40 OC 8 S. Sturla Synthetic nucleosides for probing stability and polymerase processing of DNA adducts 15:40 16:00 OC 9 I. Hirao Generation of high affinity DNA aptamers by the expansion of the genetic alphabet 16:00 16:30 Coffee Break Chairman: Annemieke Madder 16:30 17:10 PL 4 O.
    [Show full text]
  • 2‐Substituted Datp Derivatives As Building Blocks for Polymerase
    Angewandte Communications Chemie International Edition: DOI: 10.1002/anie.201609007 DNA Modification German Edition: DOI: 10.1002/ange.201609007 2-Substituted dATP Derivatives as Building Blocks for Polymerase- Catalyzed Synthesis of DNA Modified in the Minor Groove Jn Matyasˇovsky´, Pavla Perlkov, Vincent Malnuit, Radek Pohl, and Michal Hocek* Abstract: 2’-Deoxyadenosine triphosphate (dATP) derivatives polymerases, whereas 2-arylamino-dATP derivatives were [16] bearing diverse substituents (Cl, NH2,CH3, vinyl, ethynyl, and found to act as polymerase inhibitors. The minor groove phenyl) at position 2 were prepared and tested as substrates for sites of the nucleobases are difficult to modify since they are DNA polymerases. The 2-phenyl-dATP was not a substrate for crucial both for Watson–Crick base pairing and for key minor- DNA polymerases, but the dATPs bearing smaller substituents groove interactions with DNA polymerase that are important were good substrates in primer-extension experiments, produc- for extension of the chain.[17] On the other hand, 2-ethynyl- ing DNA substituted in the minor groove. The vinyl-modified pyridone-C-nucleotide incorporated into DNA[18] formed DNA was applied in thiol–ene addition and the ethynyl- a stable base pair with adenine, and 2-(imidazolylalkylami- modified DNA was applied in a CuAAC click reaction to form no)purines in ONs also stabilized duplexes.[19] Because the DNA labelled with fluorescent dyes in the minor groove possibility of minor-groove base labelling would be attractive for many prospective
    [Show full text]
  • Synthesis and Cytotoxic and Antiviral Activity Profiling of All‐Four
    Full Paper Chemistry—A European Journal doi.org/10.1002/chem.202001124 & DrugDiscovery |Hot Paper| Synthesis and Cytotoxic and Antiviral Activity Profiling of All-Four Isomeric Series of Pyrido-Fused 7-Deazapurine Ribonucleosides Lucia Veselovskµ,[a] Natµlie Kudlovµ,[b, c] SonˇaGurskµ,[b, c] Barbora Lisˇkovµ,[b] Martina Medvedíkovµ,[b] Ondrˇej Hodek,[a] Eva Tlousˇtˇovµ,[a] NemanjaMilisavljevic,[a, d] Michal Tichy´,[a] Pavla Perlíkovµ,[a] HelenaMertlíkovµ-Kaiserovµ,[a] Jana Trylcˇovµ,[a] RadekPohl,[a] Blanka Klepetµrˇovµ,[a] Petr Dzˇubµk,[b, c] MariµnHajdfflch,[b, c] and Michal Hocek*[a, d] Abstract: All four isomeric series of novel 4-substituted The most active werepyrido[4’,3’:4,5]pyrimidine nucleosides pyrido-fused 7-deazapurine ribonucleosides possessing the bearing MeO, NH2,MeS, or CH3 groups at position 4, which pyridine nitrogen atom at different positions were designed showed submicromolar cytotoxic effects and good selectivi- and synthesized. The total synthesis of each isomeric fused ty for cancer cells. The mechanism involved activation by heterocycle through multistep heterocyclizationwas fol- phosphorylation and incorporation to DNA where the pres- lowed by glycosylation and derivatization at position 4by ence of the modified ribonucleosides causes double-strand cross-coupling reactions or nucleophilic substitutions. All breaksand apoptosis. compoundswere tested for cytostatic and antiviral activity. Introduction well as of emerging new viruses,[4] justifiesthe continuous in- terest in the development of other novel nucleoside deriva- Nucleoside derivatives or analogues modified at the heterocy- tives with potential antiviral or cytostatic effects. Particularly in- clic base are an important class of molecules with wide range teresting are modified pyrrolo[2,3-d]pyrimidine(7-deazapurine) of biological activities.
    [Show full text]
  • Switching Transcription with Bacterial RNA Polymerase Through Photocaging, Photorelease and Phosphorylation Reactions in the Major Groove of DNA
    Showcasing research from Professor Hocek’s laboratory, As featured in: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic. Switching transcription with bacterial RNA polymerase through photocaging, photorelease and phosphorylation reactions in the major groove of DNA In Nature, transcription is regulated by methylation and demethylation of DNA. We have developed an artifi cial switch of in vitro transcription with bacterial RNA polymerases. We synthesized a DNA template containing photocaged 5-hydroxymethyluracils (as surrogates of natural T) and the transcription was blocked. Through irradiation with visible light (400 nm) we cleaved off the masking groups and the transcription was switched ON. Then See Libor Krásný, Michal Hocek et al., by enzymatic phosphorylation of hydroxymethyluracils we have Chem. Sci., 2019, 10, 3937. switched the transcription OFF again. It is the fi rst step towards artifi cial bioorthogonal chemical epigenetics. rsc.li/chemical-science Registered charity number: 207890 Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Switching transcription with bacterial RNA polymerase through photocaging, photorelease Cite this: Chem. Sci.,2019,10,3937 All publication charges for this article and phosphorylation reactions in the major groove have been paid for by the Royal Society † of Chemistry of DNA ab c c c Zuzana Van´ıkova,´ ‡ Martina Janouˇskova,´ ‡ Milada Kambova,´ Libor Krasn´ y´ * and Michal Hocek *ab We report proof of principle biomimetic switching of transcription in vitro through non-natural chemical reactions in the major groove of DNA templates. Photocaged DNA templates containing nitrobenzyl- protected 5-hydroxymethyluracil or – cytosine permitted no transcription with E. coli RNA polymerase (OFF Received 14th January 2019 state).Theirirradiationwith400nmlightresultedinDNA templates containing hydroxymethylpyrimidines, Accepted 1st March 2019 which switched transcription ON with a higher yield (250–350%) compared to non-modified DNA.
    [Show full text]
  • Pavlína Vidláková
    MASARYKOVA UNIVERZITA PŘÍRODOVĚDECKÁ FAKULTA STUDIUM ELEKTROCHEMICKÝCH VLASTNOSTÍ SYNTETICKÝCH OLIGONUKLEOTIDŮ A DNA MODIFIKOVANÝCH REDOX-AKTIVNÍMI SKUPINAMI Disertační práce Pavlína Vidláková Vedoucí práce: Doc. RNDr. Miroslav Fojta CSc. Brno 2015 Bibliografický záznam Autor: Mgr. Pavlína Vidláková Studium elektrochemických vlastností syntetických Název práce: oligonukleotidů a DNA modifikovaných redox- aktivními skupinami Studijní program: Fyzika Studijní obor: Biofyzika Vedoucí práce: Doc. RNDr. Miroslav Fojta CSc. Akademický rok: 2014/15 Počet stran: 53+57 Klíčová slova: DNA, elektrochemie, elektrochemické značení, biosensor Bibliographic Entry Author Mgr. Pavlína Vidláková Study of electrochemical properties of of synthetic Title of Thesis: oligonucleotides and DNA modified with redox-active moieties Degree programme: Physics Field of Study: Biophysics Supervisor: Doc. RNDr. Miroslav Fojta CSc. Academic Year: 2014/15 Number of Pages: 53+57 Keywords: DNA, electrochemistry, electrochemical labeling, biosensor Poděkování Na tomto místě bych chtěla poděkovat svému školiteli Doc. RNDr. Miroslavu Fojtovi CSc. a také Mgr. Luďkovi Havranovi Dr. za jejich odborné vedení a cenné rady a také za připomínky při zpracování této práce. Déle děkuji kolegům z Biofyzikálního ústavu za příjemné pracovní prostředí a veškerou pomoc, které se mi od nich dostalo. Prohlášení Prohlašuji, že jsem svoji rigorózní práci vypracovala samostatně s využitím informačních zdrojů, které jsou v práci citovány. Brno 6. března 2015 ……………………………… Pavlína Vidláková © Pavlína Vidláková, Masarykova Universita, 2015 Abstrakt V této disertační práci se věnujeme elektrochemické analýze nukleotidových sekvencí s využitím elektrochemických značek a vlastnostem těchto značek. Teoretická část práce je zaměřena na shrnutí poznatků týkajících se elektrochemického chování nukleových kyselin a oligonukleotidů s využitím různých typů elektrod a elektrochemických metod. Dále jsou zde popsány metody značení nukleových kyselin elektroaktivními značkami a také příprava a použití DNA-biosenzorů.
    [Show full text]
  • Polymerase Synthesis of DNA Labelled with Benzylidene Cyanoacetamide-Based Fluorescent Cite This: Chem
    ChemComm View Article Online COMMUNICATION View Journal | View Issue Polymerase synthesis of DNA labelled with benzylidene cyanoacetamide-based fluorescent Cite this: Chem. Commun., 2015, 51, 4880 molecular rotors: fluorescent light-up probes for Received 19th January 2015, DNA-binding proteins† Accepted 10th February 2015 a a ab DOI: 10.1039/c5cc00530b Dmytro Dziuba, Radek Pohl and Michal Hocek* www.rsc.org/chemcomm Viscosity-sensitive fluorophores, fluorescent molecular rotors based would be advantageous. In our proof-of-the-principle studies we on aminobenzylidene–cyanoacetamide moiety, were tethered to showed that dNTPs bearing suitable environmentally sensitive 20-deoxycytidine triphosphate via apropargylaminelinkerandincor- fluorescent reporter (either solvatochromic aminophthalimide7 or porated into DNA by polymerases in primer extension, nicking GFP-fluorophore as a molecular rotor8)canbeincorporatedinto Creative Commons Attribution 3.0 Unported Licence. enzyme amplification or PCR. DNA probes incorporating modified DNA by polymerases. The resulting probes showed a light-up response nucleosides show a light-up response upon binding to a protein. upon binding to proteins, although the increase of fluorescence was rather low (max. 2.5-fold).7,8 Therefore, development of more sensitive Fluorescent probes targeting DNA-binding proteins are of great value fluorophores is highly desirable. for cell biology to study signaling pathways, for medicinal chemistry to Here we report improved fluorescent dNTPs based on molecular develop drug screening assays, and for clinical chemistry to detect rotors, their enzymatic incorporation into DNA and use for sensing of biomarkers.1 Although fluorescence spectroscopy is a powerful DNA–protein interactions. Fluorescent molecular rotors (FMRs) are a method for studying biomolecular interactions, the existing methods class of fluorescent dyes sensitive to local viscosity.
    [Show full text]
  • (2-Thienyl)-7-Deazaadenosine (AB61), a New Potent Nucleoside
    Published OnlineFirst January 27, 2016; DOI: 10.1158/1535-7163.MCT-14-0933 Small Molecule Therapeutics Molecular Cancer Therapeutics 7-(2-Thienyl)-7-Deazaadenosine (AB61), a New Potent Nucleoside Cytostatic with a Complex Mode of Action Pavla Perlkova1, Gabriela Rylova2, Petr Naus1,Tomas Elbert1, Eva Tloust'ova1, Aurelie Bourderioux1, Lenka Postova Slavet nska1, Kamil Motyka3, Dalibor Dolezal 2, Pawel Znojek2, Alice Nova2, Monika Harvanova2, Petr Dzub ak 2, Michal Siller 2, Jan Hlavac2,3, Marian Hajduch 2, and Michal Hocek1,4 Abstract 7-(2-Thienyl)-7-deazaadenosine (AB61) showed nanomolar protein translation/folding machinery. Indeed, formation cytotoxic activities against various cancer cell lines but only of large 53BP1 foci was observed in nuclei of AB61-treated mild (micromolar) activities against normal fibroblasts. The U2OS-GFP-53BP1 cells indicating DNA damage. Random selectivity of AB61 was found to be due to inefficient phos- incorporation of AB61 into RNA blocked its translation in an phorylation of AB61 in normal fibroblasts. The phosphoryla- in vitro assay and reduction of reporter protein expression was tion of AB61 in the leukemic CCRF-CEM cell line proceeds well also observed in mice after 4-hour treatment with AB61. AB61 and it was shown that AB61 is incorporated into both DNA and also significantly reduced tumor volume in mice bearing SK- RNA, preferentially as a ribonucleotide. It was further con- OV-3, BT-549, and HT-29 xenografts. The results indicate that firmed that a triphosphate of AB61 is a substrate for both RNA AB61 is a promising compound with unique mechanism of and DNA polymerases in enzymatic assays.
    [Show full text]
  • X0005d;Pyrimidine (7‐Deazapurine)
    Received: 19 April 2017 Revised: 26 July 2017 Accepted: 26 July 2017 DOI: 10.1002/med.21465 REVIEW ARTICLE Pyrrolo[2,3-d]pyrimidine (7-deazapurine) as a privileged scaffold in design of antitumor and antiviral nucleosides Pavla Perlíková1 Michal Hocek1,2 1Institute of Organic Chemistry and Biochem- istry, Czech Academy of Sciences, CZ-16610, Abstract Prague 6, Czech Republic 7-Deazapurine (pyrrolo[2,3-d]pyrimidine) nucleosides are important 2Department of Organic Chemistry, Faculty of analogues of biogenic purine nucleosides with diverse biological Science, Charles University in Prague, CZ-12843, activities. Replacement of the N7 atom with a carbon atom makes Prague 2, Czech Republic the five-membered ring more electron rich and brings a possibility of Correspondence attaching additional substituents at the C7 position. This often leads Michal Hocek, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, to derivatives with increased base-pairing in DNA or RNA or bet- Flemingovo nam. 2, CZ-16610 Prague 6, Czech ter binding to enzymes. Several types of 7-deazapurine nucleosides Republic. with potent cytostatic or cytotoxic effects have been identified. The Email: [email protected] most promising are 7-hetaryl-7-deazaadenosines, which are acti- vated in cancer cells by phosphorylation and get incorporated both to RNA (causing inhibition of proteosynthesis) and to DNA (caus- ing DNA damage). Mechanism of action of other types of cytostatic nucleosides, 6-hetaryl-7-deazapurine and thieno-fused deazapurine ribonucleosides, is not yet known. Many 7-deazaadenosine deriva- tives are potent inhibitors of adenosine kinases. Many types of sugar- modified derivatives of 7-deazapurine nucleosides are also strong antivirals.
    [Show full text]
  • Annual Meeting of the International Society of Electrochemistry I
    Program of the 59th Annual Meeting of the International Society of Electrochemistry i The 59th Annual Meeting of the International Society of Electrochemistry Electrochemistry Down to the Molecular Level: Interfacial Science for Life and Technology September 7 to 12, 2008 Seville, Spain PROGRAM ETY O CI F E O L S E C L T A R O N C O I H T E A M N I R S E T T R Y N I • ii Program of the 59th Annual Meeting of the International Society of Electrochemistry International Society of Electrochemistry Rue de Sébeillon 9b 1004 Lausanne Switzerland Copyright © 2008 All rights reserved. No part of this work may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the Publisher. No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of product liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Printed in Spain Program of the 59th Annual Meeting of the International Society of Electrochemistry iii Welcome Address he organizing committee of the 59th Annual Meeting of the International Society of Electrochemistry warmly invites you to visit Seville on September 7-12, 2008 and contribute to the scientific presentations Tand discussions related to the main subject of the meeting: Electrochemistry Down to the Molecular Level: Interfacial Science for Life and Technology. Seville is located in the South of Spain on the plain of the Guadalquivir River, which flows through the city.
    [Show full text]
  • Open Full Page
    Published OnlineFirst January 27, 2016; DOI: 10.1158/1535-7163.MCT-14-0933 Small Molecule Therapeutics Molecular Cancer Therapeutics 7-(2-Thienyl)-7-Deazaadenosine (AB61), a New Potent Nucleoside Cytostatic with a Complex Mode of Action Pavla Perlkova1, Gabriela Rylova2, Petr Naus1,Tomas Elbert1, Eva Tloust'ova1, Aurelie Bourderioux1, Lenka Postova Slavet nska1, Kamil Motyka3, Dalibor Dolezal 2, Pawel Znojek2, Alice Nova2, Monika Harvanova2, Petr Dzub ak 2, Michal Siller 2, Jan Hlavac2,3, Marian Hajduch 2, and Michal Hocek1,4 Abstract 7-(2-Thienyl)-7-deazaadenosine (AB61) showed nanomolar protein translation/folding machinery. Indeed, formation cytotoxic activities against various cancer cell lines but only of large 53BP1 foci was observed in nuclei of AB61-treated mild (micromolar) activities against normal fibroblasts. The U2OS-GFP-53BP1 cells indicating DNA damage. Random selectivity of AB61 was found to be due to inefficient phos- incorporation of AB61 into RNA blocked its translation in an phorylation of AB61 in normal fibroblasts. The phosphoryla- in vitro assay and reduction of reporter protein expression was tion of AB61 in the leukemic CCRF-CEM cell line proceeds well also observed in mice after 4-hour treatment with AB61. AB61 and it was shown that AB61 is incorporated into both DNA and also significantly reduced tumor volume in mice bearing SK- RNA, preferentially as a ribonucleotide. It was further con- OV-3, BT-549, and HT-29 xenografts. The results indicate that firmed that a triphosphate of AB61 is a substrate for both RNA AB61 is a promising compound with unique mechanism of and DNA polymerases in enzymatic assays.
    [Show full text]
  • Strategies Toward Protecting Group-Free Glycosylation Through Selective Activation of the Anomeric Center
    Strategies toward protecting group-free glycosylation through selective activation of the anomeric center A. Michael Downey1 and Michal Hocek*1,2 Review Open Access Address: Beilstein J. Org. Chem. 2017, 13, 1239–1279. 1Institute of Organic Chemistry and Biochemistry, Czech Academy of doi:10.3762/bjoc.13.123 Sciences, Flemingovo nam. 2, 16610 Prague 6, Czech Republic and 2Department of Organic Chemistry, Faculty of Science, Charles Received: 08 March 2017 University in Prague, 12843 Prague 2, Czech Republic Accepted: 01 June 2017 Published: 27 June 2017 Email: Michal Hocek* - [email protected] Associate Editor: S. Flitsch * Corresponding author © 2017 Downey and Hocek; licensee Beilstein-Institut. License and terms: see end of document. Keywords: glycosides; glycosylation; oligosaccharides; protecting groups Abstract Glycosylation is an immensely important biological process and one that is highly controlled and very efficient in nature. However, in a chemical laboratory the process is much more challenging and usually requires the extensive use of protecting groups to squelch reactivity at undesired reactive moieties. Nonetheless, by taking advantage of the differential reactivity of the anomeric center, a selective activation at this position is possible. As a result, protecting group-free strategies to effect glycosylations are available thanks to the tremendous efforts of many research groups. In this review, we showcase the methods available for the selective activation of the anomeric center on the glycosyl donor and the mechanisms by which the glycosylation reactions take place to illustrate the power these techniques. Review 1 Introduction The glycosylation reaction is of extreme importance in nature as termed the acceptor, with the product of the reaction termed it is possibly the most prevalent post-translational modification glycoside.
    [Show full text]