Search for dissertations about: "ring modification"

Showing result 21 - 25 of 45 swedish dissertations containing the words ring modification.

  1. 21. New synthetic routes to azaspiro alkaloids : Applications to the synthesis perhydrohistrionicotoxin

    Author : Lars Hagberg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

    Abstract : Perhydrohistrionicotoxin, 1, is related to a family of alkaloids which display pharmacologically interesting properties. The thesis deals with development of new methods for the chemical synthesis of such alkaloids, and is divided into three parts according to the different approaches. READ MORE

  2. 22. Conformationally Constrained Oligonucleotides for RNA Targeting

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

    Abstract : 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. READ MORE

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

    Author : Dmytro Honcharenko; Jyoti Chattopadhyaya; Piet Herdewijn; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 24. Environment-Sensitive Multifunctional Drug Delivery Systems

    Author : Jian Qin; Mamoun Muhammed; Marcus Textor; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Materials chemistry; Materialkemi;

    Abstract : Drug delivery systems (DDS) with multiple functionalities such as environment-sensitive drug release mechanisms and visualization agents have motivated the biomedical community as well as materials chemists for more than a decade. This dissertation is concerned with the development of nanoparticles for multifunctional DDS  to tackle several crucial challenges in these complex systems, including polymeric nanospheres which respond to temperature change, superparamagnetic iron oxide nanoparticles/polymeric composite for magnetic resonance imaging contrast agents and drug carriers, immunoresponse of nanomaterials and injectable magnetic field sensitive ferrogels. READ MORE

  5. 25. Interaction studies of idiotypic and antiidiotypic antibodies at experimental tumor targeting

    Author : Ann Erlandsson; Mats Ohlin; Umeå universitet; []
    Keywords : anti-idiotypic antibody; clearing; cytokeratin 8; epitope; idiotypic antibody; immunotherapy;

    Abstract : An increasing number of antibodies are being labeled with radionuclides for immunotargeting, but the negative side effects generated on normal tissues by the nuclide remains a significant problem. The clearing of non-tumor-targeted radiolabeled antibodies from the circulation contributes significantly to improved targeting; it has been demonstrated that anti-idiotypic antibodies can be used for this purpose. READ MORE