Sökning: "conformationally constrained nucleosides"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden conformationally constrained nucleosides.

  1. 1. Conformationally Constrained Nucleosides Design, Synthesis, and Biochemical Evaluation of Modified Antisense Oligonucleotides

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Oommen P. Varghese; Uppsala universitet.; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; chemically modified oligonucleotides; azetidine; aza-ENA-T; cyanomethylene locked; free energy of activation; diaxial interactions; chair conformation; stable duplex; human serum; snake venom phosphodiesterase; antisense agents; RNase H; Organisk kemi; NATURAL SCIENCES Chemistry; NATURVETENSKAP Kemi;

    Sammanfattning : This thesis is concerned with synthesis, structure and biochemical analysis of chemically modified oligonucleotides with potential therapeutic applications. The three types of chemical modifications described here are: (a) A North-East locked 1',2'-azetidine nucleoside (b) A North locked 2',4'-cyanomethylene bridged nucleoside and (c) A 2',4'-aza-ENA-T nucleoside. LÄS MER

  2. 2. Conformationally Constrained Nucleosides, Nucleotides and Oligonucleotides Design, Synthesis and Properties

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Dmytro Honcharenko; Jyoti Chattopadhyaya; Piet Herdewijn; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bioorganic chemistry; antisense oligonucleotides; conformationally constrained nucleosides; azetidine; aza-ENA; target affinity; RNase H; exonuclease stability; pyrene-functionalized nucleotides; fluorescence; mismatch discrimination; Bioorganisk kemi; NATURAL SCIENCES Biology Cell and molecular biology; NATURVETENSKAP Biologi Cell- och molekylärbiologi;

    Sammanfattning : This thesis is based on six original research publications describing synthesis, structure and physicochemical and biochemical analysis of chemically modified oligonucleotides (ONs) in terms of their potential diagnostic and therapeutic applications. Synthesis of two types of bicyclic conformationally constrained nucleosides, North-East locked 1',2'-azetidine and North locked 2',4'-aza-ENA, is described. LÄS MER

  3. 3. Conformationally Constrained Oligonucleotides for RNA Targeting

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Qing Li; Jyoti Chattopadhyaya; Li-He Zhang; [2012]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; conformationally constrained nucleoside; antisense oligonucleotide; RNA affinity; nuclease stability; RNase H; RNA degradation; Chemistry with specialization in Bioorganic Chemistry; Kemi med inriktning mot bioorganisk kemi;

    Sammanfattning : A short oligonucleotide sequence as in a single-stranded antisense oligo nucleotides (AON) or in double-stranded small interfering RNAs (siRNA) can modulate the gene expression by targeting against the cellular mRNA, which can be potentially exploited for therapeutic purposes in the treatment of different diseases. In order to improve the efficacy of oligonucleotide-based drugs, the problem of target affinity, nuclease stability and delivery needs to be addressed. LÄS MER

  4. 4. Structural and Biophysical Studies of Nucleic Acids

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Wimal Pathmasiri; Uppsala universitet.; [2007]
    Nyckelord :Organic chemistry; nucleic acids; Nuclear Magnetic Resonance; molecular dynamics; sugar modified nucleosides; pKa; Organisk kemi;

    Sammanfattning : This thesis is based on six research publications concerned with (i) study of the molecular structures and dynamics of modified nucleosides; (ii) investigation of the effect of incorporation of modified nucleosides on the structure of DNA; (iii) examination of the effect of the sugar modifications on the pseudo-aromatic properties (pKa) of the nucleobases; (iv) analysis of the effect of the CH-π interactions on the relative stability of the DNA-RNA hybrid duplexes. The structural stability of the nucleic acids as well as their behavior in molecular recognition is dominated by hydrogen bonding and stacking interactions beside other non-covalent interactions. LÄS MER

  5. 5. Carbon-Carbon Bond Formation via Radical Cyclization and Transition Metal Catalysis

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Puneet Srivastava; Lars Engman; Ullrich Jahn; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radical cyclizations; transition metal catalysis; NATURAL SCIENCES Chemistry; NATURVETENSKAP Kemi; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

    Sammanfattning : Free radical cyclization methodology has been used extensively in synthesis for manipulation of complex molecules such as alkaloids, terpenes, carbohydrates, peptides and nucleic acids. The methodology has emerged as a result of work by physical organic chemists who determined rate constants for the most common radical reactions used in organic synthesis. LÄS MER