Sökning: "sugar modified nucleosides"

Hittade 5 avhandlingar innehållade orden sugar modified nucleosides.

1. 1. Conformationally Constrained Nucleosides, Nucleotides and Oligonucleotides : Design, Synthesis and Properties

   Författare :Dmytro Honcharenko; Jyoti Chattopadhyaya; Piet Herdewijn; Uppsala universitet; []
   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; Cell and molecular biology; 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. 2. Structural and Biophysical Studies of Nucleic Acids

   Författare :Wimal Pathmasiri; Adolf Gogoll; Lena Mäler; Uppsala universitet; []
   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

4. 3. Conformationally Constrained Oligonucleotides for RNA Targeting

   Författare :Qing Li; Jyoti Chattopadhyaya; Li-He Zhang; Uppsala universitet; []
   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

5. 4. Novel Pentofuranose Chemistry to Modulate RNA Function

   Författare :Mansoureh Karimiahmadabadi; Jyoti Chattapadhyaya; Jesper Wengel; Uppsala universitet; []
   Nyckelord :pentofuranose chemistry; conformationally locked nucleoside; carbocyclic-LNA; bicyclo[2.2.1]heptane;

   Sammanfattning : Chemical modifications of oligonucleotides provide an important tool to understand how the natural substrate works as well as how to improve their biochemical and biological properties as potential therapeutics and diagnostics. Our carba-LNA (2',4'-carba-bridged Locked Nucleic Acid) modified oligo-DNA or -RNA have been found to be useful to modulate oligo-RNA and -DNA activity. LÄS MER

7. 5. Some Aspects of Nucleic Acids Chemistry

   Författare :Edouard Zamaratski; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bioorganic chemistry; Bioorganisk kemi; Bioorganic chemistry; Bioorganisk kemi; bioorganisk kemi; Biorganic Chemistry;

   Sammanfattning : This thesis is divided into two parts based on a total of 8 papers: Part 1: Synthesis, physicochemical and biochemical studies of chemically modified oligonucleotides and their duplexes and triplexes. Potency of the chromophore conjugated DNA oligonucleotides as antigene and antisense gene repressors was evaluated. LÄS MER