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Pfadler W, Pfleiderer W. Syntheses and properties of pterin ribonucleosides. ARKIVOC 2008. [DOI: 10.3998/ark.5550190.0010.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Pfleiderer W. Universal 2-(4-nitrophenyl)ethyl and 2-(4-nitrophenyl)ethoxycarbonyl protecting groups for nucleosides and nucleotides. ACTA ACUST UNITED AC 2008; Chapter 2:Unit 2.13. [PMID: 18428974 DOI: 10.1002/0471142700.nc0213s30] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A universal blocking group strategy for nucleobases is described, using the 2-(4-nitrophenyl)ethyl (NPE) group for O4-T-, O4-U-, O6-dG-, and O6-G-protection as well as the 2-(4-nitrophenyl)ethoxycarbonyl (NPEOC) group for amino protection in dC, C, dA, A, dG, and G. Conversion into the corresponding 5'-O-dimethoxytrityl derivatives and subsequent phosphitylation to form the fully protected 3'-O-(2-cyanoethyl-N,N-diisopropylphosphoramidites) and 3'-O-(2-(4-nitrophenyl)ethyl-N,N-diisopropylphosphoramidites) produces a new class of interesting building blocks for oligonucleotide synthesis.
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Moheno P, Pfleiderer W, DiPasquale AG, Rheingold AL, Fuchs D. Cytokine and IDO metabolite changes effected by calcium pterin during inhibition of MDA-MB-231 xenograph tumors in nude mice. Int J Pharm 2008; 355:238-48. [PMID: 18272305 DOI: 10.1016/j.ijpharm.2007.12.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 12/15/2007] [Accepted: 12/17/2007] [Indexed: 11/15/2022]
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Wöll D, Laimgruber S, Galetskaya M, Smirnova J, Pfleiderer W, Heinz B, Gilch P, Steiner UE. On the Mechanism of Intramolecular Sensitization of Photocleavage of the 2-(2-Nitrophenyl)propoxycarbonyl (NPPOC) Protecting Group. J Am Chem Soc 2007; 129:12148-58. [PMID: 17877342 DOI: 10.1021/ja072355p] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A spectroscopic study of a variety of covalently linked thioxanthone(TX)-linker-2-(2-nitrophenyl)propoxycarbonyl(NPPOC)-substrate conjugates is presented. Herein, the TX chromophore functions as an intramolecular sensitizer to the NPPOC moiety, a photolabile protecting group used in photolithographic DNA chip synthesis. The rate of electronic energy transfer between TX and NPPOC was quantified by means of stationary fluorescence as well as nanosecond and femtosecond time-resolved laser spectroscopy. A dual mechanism of triplet-triplet energy transfer has been observed comprising a slower mechanism involving the T1(pipi*) state of TX with linker-length-dependent time constants longer than 20 ns and a fast mechanism with linker-length-dependent time constants shorter than 3 ns. Evidence is provided that the latter mechanism is due to energy transfer from the T2(npi*) state which is in fast equilibrium with the fluorescent S1(pipi*) state. In the case of direct linkage between the aromatic rings of TX and NPPOC, the spectroscopic properties are indicative of one united chromophore which, however, still shows the typical NPPOC cleavage reaction triggered by intramolecular hydrogen atom transfer to the nitro group.
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Charubala R, Pfleiderer W, Suhadolnik RJ, Sobol RW. Chemical Synthesis and Biological Activity of 2′-5′-Phosphorothioate Tetramer Cores. ACTA ACUST UNITED AC 2007. [DOI: 10.1080/07328319108046484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hijazi A, Pfleiderer W. Nucleosides, XL1Synthesis and Properties of lin-Naphthamidazole-Ribonucleosides. ACTA ACUST UNITED AC 2007. [DOI: 10.1080/07328318408081289] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Dimitrova DI, Reichenbach NL, Yang X, Pfleiderer W, Charubala R, Gaughan JP, Suh B, Henderson EE, Suhadolnik RJ, Rogers TJ. Inhibition of HIV type 1 replication in CD4+ and CD14+ cells purified from HIV type 1-infected individuals by the 2-5A agonist immunomodulator, 2-5A(N6B). AIDS Res Hum Retroviruses 2007; 23:123-34. [PMID: 17263642 PMCID: PMC1941645 DOI: 10.1089/aid.2005.0091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Two major interferon (IFN)-mediated antiviral defense enzymes are double-stranded (ds)RNA-dependent 2',5'-oligoadenylate (2-5A) synthetase (2-5OAS) and p68 kinase (PKR). When activated by dsRNA, 2-5OAS synthesizes 2-5A, which binds to and activates RNase L. Activated RNase L hydrolyzes single-stranded viral RNA, thereby inhibiting viral protein synthesis. HIV-1 inhibits the IFN-mediated intracellular antiviral pathways. We have reported the synthesis and characterization of a nuclease-resistant 2-5A agonist (2-5A(N6B)) that overcomes the HIV-1 induced blockades by restoring the 2-5OAS/RNase L antiviral pathway (Homan JW, et al., J Acquir Immune Defic Syndr 2002;30:9-20). The objective of this study was to test the effect of 2-5A(N6B) on chronically infected CD4(+) T lymphocytes and CD14(+) monocytes derived from HIV-1-seropositive individuals. Wild-type HIV-1 replication was effectively inhibited by 2-5A(N6B) in CD4(+) T lymphocytes and CD14(+) monocytes purified from HIV-1 seropositive individuals (n = 18) compared to untreated cells. We also assessed the cytotoxicity of 2-5A(N6B) and report that 2-5A(N6B) exerts its anti-HIV-1 activity with no evidence of cytotoxicity (IC(90) > 100,000 nM). Furthermore, 2-5A(N6B) did not alter the cellular RNA profile, affect CCR5 or CXCR4 coreceptor expression, or activate caspase-dependent apoptosis. Evidence is also provided to show that 2-5A(N6B), and naturally occurring 2-5A(4), act as ligands to activate human Toll-like receptor 4. These results indicate that the 2-5A agonist 2-5A(N6B) has the potential to enhance host cell innate and acquired immune defense mechanisms against HIV-1 infection.
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Suhadolnik RJ, Doetsch PW, Devash Y, Henderson EE, Charubala R, Pfleiderer W. 2′,5′-Adenylate and Cordycepin Trimer Cores: Metabolic Stability and Evidence for Antimitogenesis without 5′-Rephosphorylation. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318308078869] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Himmelsbach F, Uhlmann E, Charubala R, Pfleiderer W. Synthesis of 3′-Deoxyadenylate Trimer. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318508077852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Pfleiderer W, Himmelsbach F, Charubala R, Schirmeister H, Beiter A, Schulz B, Trichtinger T. The p-Nitrophenylethyl Group - An Universal Blocking Group in Nucleoside and Nucleotide Chemistry. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318508077832] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Charubala R, Pfleiderer W. The Chemical Syntheses of (2′-5′)-P-Thioadenylate Dimers, Trimers and Tetramers. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318808056313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Pfister M, Farkas S, Charubala R, Pfleiderer W. Recent Progress in Oligoribonucleotide Synthesis. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328318808056292] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Bühler S, Giegrich H, Pfleiderer W. New Photolabile Protecting Groups of the 2-(2-Nitrophenyl)ethoxycarbonyl- and the 2-(2-Nitrophenyl)ethylsulfonyl-Type for the Oligonucleotide Synthesis. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319908044692] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Pey AL, Martinez A, Charubala R, Maitland DJ, Teigen K, Calvo A, Pfleiderer W, Wood JM, Schallreuter KU. Specific interaction of the diastereomers 7(R)- and 7(S)-tetrahydrobiopterin with phenylalanine hydroxylase: implications for understanding primapterinuria and vitiligo. FASEB J 2006; 20:2130-2. [PMID: 16935936 DOI: 10.1096/fj.06-5835fje] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pterin-4a-carbinolamine dehydratase (PCD) is an essential component of the phenylalanine hydroxylase (PAH) system, catalyzing the regeneration of the essential cofactor 6(R)-L-erythro-5,6,7,8-tetrahydrobiopterin [6(R)BH4]. Mutations in PCD or its deactivation by hydrogen peroxide result in the generation of 7(R,S)BH4, which is a potent inhibitor of PAH that has been implicated in primapterinuria, a variant form of phenylketonuria, and in the skin depigmentation disorder vitiligo. We have synthesized and separated the 7(R) and 7(S) diastereomers confirming their structure by NMR. Both 7(R)- and 7(S)BH4 function as poor cofactors for PAH, whereas only 7(S)BH4 acts as a potent competitive inhibitor vs. 6(R)BH4 (Ki=2.3-4.9 microM). Kinetic and binding studies, as well as characterization of the pterin-enzyme complexes by fluorescence spectroscopy, revealed that the inhibitory effects of 7(R,S)BH4 on PAH are in fact specifically based on 7(S)BH4 binding. The molecular dynamics simulated structures of the pterin-PAH complexes indicate that 7(S)BH4 inhibition is due to its interaction with the polar region at the pterin binding site close to Ser-251, whereas its low efficiency as cofactor is related to a suboptimal positioning toward the catalytic iron. 7(S)BH4 is not an inhibitor for tyrosine hydroxylase (TH) in the physiological range, presumably due to the replacement of Ser-251 by the corresponding Ala297. Taken together, our results identified structural determinants for the specific regulation of PAH and TH by 7(S)BH4, which in turn aid in the understanding of primapterinuria and acute vitiligo.
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Giegrich H, Eisele-Bühler S, Hermann C, Kvasyuk E, Charubala R, Pfleiderer W. New Photolabile Protecting Groups in Nucleoside and Nucleotide Chemistry—Synthesis, Cleavage Mechanisms and Applications. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319808004738] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Matysiak S, Frank R, Pfleiderer W. Acetal Oligonucleotide Conjugates in Antisense Strategy. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708002963] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Lazrek HB, Engels JW, Pfleiderer W. Synthesis of Novel Branched Nucleoside Dimers Containing a 1,2,3-Triazolyl Linkage. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319808004722] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Sigmund H, Maier T, Pfleiderer W. A New Type of Fluorescence Labeling of Nucleosides, Nucleotides and Oligonucleotides. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708002935] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jungmann O, Pfleiderer W. Pteridine Nucleosides Analogs of 2′-Deoxyadenosine as Building Blocks for Oligonucleotide Synthesis. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708002964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Münch U, Pfleiderer W. The (2-Cyano-1-phenyl)ethoxycarbonyl (CPEOC) Group-A New Protecting Group for Oligoribonucleotide Synthesis. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708002955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Srikrishnan T, Parthasarathy R, Pfleiderer W, De** NC, Chheda** GB. Cis-transIsomerization of the N-Formyl Amino Group in a Novel Modified Uracil Derivative: 6-Amino-3-methyl-5-(N-Formylamino)uracil. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319708001345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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