Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Carbocyclic analogs of nucleosides. Part 2.Part 1: [1].. Synthesis of 2′,3′-dideoxy-5′-homonucleoside analogs (1992)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 75 (1992), S. 1944-1954 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A set of derivatives of cyclopentaneacetic acid cis-substituted at position 3 by nucleoside bases (both purines and pyrimidines) were prepared and characterized (see 11, 14, and 23a, b; Schemes 2-4). These molecules are carbocyclic analogs of 2′,3′-dideoxy-5′-homonucleosides. In this synthesis, the skeleton was constructed from norbornanone and a novel method based on Mitsunobu chemistry used for the introduction of nucleoside-base substituents. The scope of this method was further explored via the preparation of a cyclobutyl analog of dideoxyguanosine (see 17, Scheme 3).
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19920750620
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Synthesis, Molecular Recognition, and Enzymology of Oligonucleotides Containing the Non-standard Base Pair between 5-Aza-7-deazaisoguanine and 6-Amino-3-methylpyrazin-2(1H)-one, a Donor-Acceptor-Acceptor Purine Analog and an Acceptor-Donor-Donor Pyrimidine Analog (1996)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 79 (1996), S. 1881-1898 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A 6-aminopyrazin-2(1H)-one (pyADD), when incorporated as a pyrimidine-base analog into an oligonucleotide chain, presents a H-bond acceptor-donor-donor pattern to 5-aza-7-deazaisoguanine (puDAA), the complementrary donor-acceptor-acceptor purine analog. Reported here are the syntheses of the phosphoramidite of the 2′-deoxyribonucleoside bearing the puDAA base, oligonucleotides containing this nucleoside unit, the enzyme-assisted synthesis of oligoribonucleotides containing the pyADD ribonucleoside, and the molecular-recognition properties of this non-standard base pair in an oligonucleotide context. A series of melting experiments suggests that the pyADD · puDAA base pair contributes to the relative stability of a duplex structure approximately the same as an A · T base pair, and significantly more than mismatches between these non-standard bases and certain standard nucleobases. The pyADD nucleoside bisphosphate is accepted by T4 RNA ligase, but the triphosphate of the pyADD nucleoside was not incorported by T7 RNA polymerase opposite the puDAA nucleobase in a template. Oligonucleotides containing the pyADD base slowly undergo a reversible first-order reaction, presumably an epimerization process to give the α-D-anomer. These experiments provide the tools for laboratory-based use of the pyADD · puDAA base pair as a component of an oligonucleotide-like molecular-recognition system based on an expanded genetic alphabet.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19960790711
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A Direct Route to 3-(D-Ribofuranosyl)pyridine Nucleosides (1991)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 74 (1991), S. 397-406 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A route for synthesizing C-nucleosides with 2,6-substituted pyridines as heterocyclic aglycones is described. Condensation of appropriately substituted lithiated pyridines with ribono-1,4-lactone derivatives yields hemiacetal 4a-g (Table 1), which can be reduced by Et3SiH and BF3·Et2O to the corresponding C-nucleoside (see Scheme 1 for 4d → β-D-5). Conditions are presented that optimize the amount of the 2,6-dichloropyridine-derived β-D-anomer β-D-5 formed (Table 3). Aminolysis of β-D-5 yields the diaminonucleoside 14 (Scheme 3).
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19910740217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Determination of the Absolute Configuration of Dimethyl (2S,3S)-2-Allyl-3-hydroxyglutarate: A Chiral Building Block for Preparing Branched-Chain Nucleoside Analogues (1993)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 76 (1993), S. 2969-2975 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A yeast-catalyzed reduction of dimethyl (2S,3S)-2-allyl-3-hydroxyglutarate is the key step in the preparation of bis-homo, branched-chain nucleoside analogues. To establish unambiguously the stereochemical course of the microbial reaction, the product has been converted to a derivative esterified with camphanoyl chloride, and a crystal structure of the derivative solved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19930760821
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Carbocyclic Analogs of Nucleosides. Part 4.Part 3: [1]. Preparation of enantiomerically pure analogs of purine nucleosides for the synthesis of sulfone-linked oligonucleotide analogs (1993)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 76 (1993), S. 826-841 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclopentane derivatives bearing a 3-(hydroxymethyl) group, a 4-(2-hydroxyethyl) functionality, and a nucleoside base are carbocyclic variants of nucleoside analogs previously described as building blocks for the preparation of oligonucleotide analogs having dimethylene sulfone (= methanosulfonylmethano) linking groups replacing the phosphodiester linking units found in natural oligonucleotides. These carbocyclic nucleoside analogs (e.g. 17 and 20) are stable to both acid-catalyzed depurination and base-catalyzed hydrolysis, in contrast with most non-ionic analogs of oligonucleotides. Furthermore, they can be prepared with complete control over the stereochemistry at the ‘anomeric’ center. A procedure is given for preparing these purine-nucleoside analogs via the construction of an enantiomerically pure carbocyclic skeleton (Schemes 1-3), followed by a Mitsunobu-type reaction to introduce the purine-base derivatives (Scheme 4). Furthermore, preliminary results for the coupling of these analogs to yield nucleoside dimers (e.g. 26) are also reported (Scheme 5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19930760207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The Donor-Acceptor-Acceptor Purine Analog: Transformation of 5-aza-7-deaza-1H-isoguanine (=4-aminoimidazo-[1,2-a]-1,3,5-triazin-2(1H)-one) to 2′-deoxy-5-aza-7-deaza-isoguanosine using purine nucleoside phosphorylase (1993)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 76 (1993), S. 2061-2069 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new synthesis is reported for 4-aminoimidazo[1,2-a]-1,3,5-triazin-2(1H)-one ( =5-aza-7-deaza-isoguanosine; 8), a purine analog that, when incorporated into an oligonucleotide chain, presents a H-bond donor-acceptor-acceptor pattern to a complementary pyrimidine analog. A protected ribose derivative was coupled to 8 to yield 4-amino-8-(β-D-ribofuranosyl)imidazo[1,2-a]-1,3,5-triazin-2(8H)-one ( =5-aza-7-deaza-isoguanosine; 11) after deprotection, Alternatively, direct synthesis of both the ribo derivative 11 and the corresponding deoxyribo derivative 17 as the β-D-anomers was achieved using the enzyme purine nucleoside phosphorylase in a one-pot reaction. This adapts a known synthetic approach to yield a new strategy for obtaining diastereoisomerically pure deoxyribonucleoside analogs on 1-gram scales.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19930760520
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Synthesis and Characterization of Non-standard Nucleosides and Nucleotides Bearing the Acceptor-Donor-Donor Pyrimidine Analog 6-Amino-3-methylpyrazin-2(1H)-one (1996)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 79 (1996), S. 1863-1880 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 6-Aminopyrazin-2(1H)-one, when incorporated as a pyrimidine-base analog into an oligonucleotide chain, presents a H-bond acceptor-donor-donor pattern to a complementary purine analog. When paired with the corresponding donor-acceptor-acceptor purine in oligonucleotides, the heterocycle selectively contributes to the stability of the duplex, presumably by forming a base pair of Watson-Crick geometry joined by a non-standard H-bonding pattern. Aspects of the nucleoside chemistry, including syntheses of the β-furanosyl ribonucleoside 1, the ribonucleoside triphosphate 2 and the ribonucleoside bisphosphate 3 of 6-aminopyrazin-2(1H)-one are reported here. In aqueous solution, the ribonucleoside 1 was found to undergo acid- and base-catalyzed rearrangement with an apparent half-life of ca. 63 h at neutral pH and 30°. The rearrangement appears to be specific acid- and base-catalyzed. The thermodynamically most stable compound formed during this rearrangement reaction was isolated by HPLC and shown to be the β-pyranosyl form 4 of the 6-aminopyrazin-2(1H)-one nucleoside in its 4C1 chair conformation. This reactivity of 1 under physiological conditions may explain why Nature does not use this particular heterocyclic system to implement an acceptor-donor-donor H-bonding pattern in the genetic alphabet.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19960790710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Synthesis of Oligonucleotides Containing 2′-Deoxyisoguanosine and 2′-Deoxy-5-methylisocytidine Using Phosphoramidite Chemistry (1998)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 81 (1998), S. 793-811 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of oligonucleotides containing 2′-deoxy-5-methylisocytidine and 2′-deoxyisoguanosine using phosphoramidite chemistry in solid-phase oligonucleotide synthesis is described. Supporting previous observations, the N,N-diisobutylformamidine moiety was found to be a far superior protecting group than N-benzoyl for 2′-deoxy-5-methylisocytidine. 2′-Deoxy-N2-[(diisobutylamino)methylidene]-5′-(4,4′-dimethoxytityl)-5-methylisocytidine 3′-(2-cyanoethyl diisopropylphosphoramidite) (1c) incorporated multiple consecutive residues during a standard automated synthesis protocol with a coupling efficiency 〉 99% according to dimethoxytrityl release. Extending coupling times of the standard protocol to ≥ 600s using 2′-deoxy-N6-[(diisobutylamino)methylidene]-5′-O-(dimethoxytrityl)-O2-(diphenylcarbamoyl)isoguanosine, 3′-(2-cyanoethyl diisopropylphosphoramidite) (7e) led to successful incorporation of multiple consecutive 2′-deoxyisoguanosine bases with a coupling efficiency 〉 97% according to dimethoxytrityl release.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19980810502
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Predicted secondary and supersecondary structure for the serine-threonine-specific protein phosphatase family (1995)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 21 (1995), S. 1-10 
    Details
    ISSN: 0887-3585
    Keywords: protein structure prediction ; protein phosphatase ; evolution ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A bona fide consensus prediction for the secondary and supersecondary structure of the serine-threonine specific protein phosphatases is presented. The prediction includes assignments of active site segments, an internal helix, and a region of possible 310 helical structure. An experimental structure for a member of this family of proteins should appear shortly, allowing this prediction to be evaluated. © 1995 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340210102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A consensus prediction of the secondary structure for the 6-phospho-β-D-galactosidase superfamily (1995)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 21 (1995), S. 273-281 
    Details
    ISSN: 0887-3585
    Keywords: prediction contests ; α-β barrel ; protein sequence alignment ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Two separate unrefined models for the secondary structure of two subfamilies of the 6-phospho-β-D-galactosidase superfamily were independently constructed by examining patterns of variation and conservation within homologous protein sequences, assigning surface, interior, parsing, and active site residues to positions in the alignment, and identifying periodicities in these. A consensus model for the secondary structure of the entire superfamily was then built. The prediction tests the limits of an unrefined prediction made using this approach in a large protein with substantial functional and sequence divergence within the family. The protein belongs to the (α-β class), with the core β strands aligned parallel. The supersecondary structural elements that are readily identified in this model is a parallel β sheet built by strands C, D, and E, with helices 2 and 3 connecting strands (C + D) and (D + E), respectively, and an analogous α-β unit (strand G and helix 7) toward the end of the sequence. The resemblance of the supersecondary model to the tertiary structure formed by 8-fold α-β barrel proteins is almost certainly not coincidental. © 1995 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340210402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...