Search for dissertations about: "Violaceae"

Showing result 1 - 5 of 7 swedish dissertations containing the word Violaceae.

2. 1. Distribution and Chemical Diversity of Cyclotides from Violaceae : Impact of Structure on Cytotoxic Activity and Membrane Interactions

   Author : Robert Burman; Ulf Göransson; Lars Bohlin; William Gerwick; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cyclotide; Violaceae; Viola; Cytotoxic; Mechanism; In vivo; Structure-activity; Membrane; Mass spectrometry; Pharmacognosy; Farmakognosi; Pharmacognosy; Farmakognosi;

   Abstract : During the last decade there has been increased interest in the cyclotide protein family, which consist of a circular chain of approximately 30 amino acids, including six cysteines that form three disulfide bonds, arranged in a cyclic cystine knot motif. This thesis gives new insights in cyclotide distribution and occurrence in the plant family Violaceae, structure-activity relationships for cytotoxic effects, membrane disruption and adsorption on lipid membranes, and evaluates toxicity and anti-tumor activity in vivo. READ MORE

4. 2. Structure and Activity of Circular Plant Proteins : Cytotoxic Effects of Viola Cyclotides

   Author : Anders Herrmann; Ulf Göransson; Lars Bohlin; Douglas Kinghorn; Uppsala universitet; []
   Keywords : Pharmacognosy; cyclotide; cytotoxic; anti-tumour; macrocyclic; cyclic cystine knot; Alpine violet; Sweet violet; Viola; Violaceae; chemical modifications; structure-activity studies; mass spectroscopy; cDNA clones; Farmakognosi;

   Abstract : Cyclotides are a family of small and macrocyclic proteins that have been found in Violacaee and Rubiaceae plant species. These proteins contain a cystine knot: two disulfides bonds together with their connecting peptide backbone form an embedded ring which is penetrated by a third disulfide bond. READ MORE

5. 3. Cyclotides evolve : Studies on their natural distribution, structural diversity, and activity

   Author : Sungkyu Park; Göransson Ulf; Lars Bohlin; Mohamed Marahiel; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cyclotide; cyclic cystine knot; evolution; peptide synthesis; chemical ligation; QSAR; Viola; Violaceae; phylogeny; Farmakognosi; Pharmacognosy;

   Abstract : The cyclotides are a family of naturally occurring peptides characterized by cyclic cystine knot (CCK) structural motif, which comprises a cyclic head-to-tail backbone featuring six conserved cysteine residues that form three disulfide bonds. This unique structural motif makes cyclotides exceptionally resistant to chemical, thermal and enzymatic degradation. READ MORE

6. 4. Cytotoxic Cyclotides : Structure, Activity, and Mode of Action

   Author : Erika Svangård; Per Claeson; Lars Bohlin; Ulf Göransson; John H. Cardellina II; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacognosy; cyclotide; cytotoxic; cancer; cyclic cystine knot; Viola; Violaceae; liposome; hollow fibre; homology modelling; mass spectrometry; amphipathic; structure–activity; tumour; membrane disruption; necrosis; Farmakognosi; Pharmacognosy; Farmakognosi;

   Abstract : Cyclotides are small cyclic plant proteins, and this thesis addresses their cytotoxic structure-activity properties and their mode of action on human cancer cell lines. Cyclotides were isolated from Viola odorata and Viola tricolor; three novel cyclotide sequences and two known sequences, but of new origin, were identified using mass spectrometry, amino acid analysis, and Edman degradation. READ MORE

7. 5. Cyclotides : Tuning Parameters Toward Their Use in Drug Design

   Author : Mariamawit Yonathan Yeshak; Ulf Göransson; Lars Bohlin; Kaleab Asres; Robert Kiss; Uppsala universitet; []
   Keywords : cyclotide; Viola abyssinica; Viola odorata; Extraction; Violaceae; vaby; cytotoxic; genotoxic; cell penetrating; microautoradiography; LC-MS; comet assay; cycloviolacin O2; Farmakognosi; Pharmacognosy;

   Abstract : Cyclotides are plant proteins with a unique topology, defined as the cyclic cystine knot motif. The motif endows cyclotides with exceptional chemical and biological stability. They also exhibit a wide range of biological activities including insecticidal, cytotoxic, anti-HIV and antimicrobial effects. READ MORE