Sökning: "derivatisation"

Visar resultat 1 - 5 av 22 avhandlingar innehållade ordet derivatisation.

  1. 1. Purification, Stereoisomeric Analysis and Quantification of Biologically Active Compounds in Extracts from Pine Sawflies, African Butterflies and Orchid Bees

    Författare :Joakim Bång; Erik Hedenström; Kristina Sjödin; Hans-Erik Högberg; Anna-Karin Borg-Karlsson; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiochemicals; sex pheromone; pine sawflies; Bicyclus; Euglossa; chiral separation; derivatisation; GC-­MS; Organic chemistry; Organisk kemi;

    Sammanfattning : Stereochemistry plays an important role in nature because biologically important molecules such as amino acids, nucleotides and sugars, only exist in enantiomerically pure forms. Semiochemicals carry messages, between the same species (pheromones) and between different species (allelochemicals). LÄS MER

  3. 2. Derivatisation of peptides for collision-induced dissociation mass spectrometry

    Författare :Ingemar Lindh; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : This study is concerned with the mass spectrometric analysis of peptides C-terminally derivatised with aminosulphonic acids. The aim was to increase the sensitivity of detection and to simplify the fragmentation patterns obtained upon collision-induced dissociation. LÄS MER

  4. 3. Flexible Synthesis of Rigid Cyclophanes - Synthesis and derivatisation of 2,7-diaza-1,2,3,6,7,8-hexahydropyrene into chiral macrocycles

    Författare :Jörgen Toftered; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Macromolecular chemistry; Makromolekylär kemi; biomimetic; cross-linking; thiourea; urea; difluorodinitrobenzene; cyclodimerisation; Cyclophanes; macrocycles;

    Sammanfattning : Rigid, chiral and amphiphilic cyclophanes of potential use as biomimetic host molecules were prepared by cyclic dimerisation of chiral diamino building blocks with amino-reactive cross-linking reagents. A reliable synthesis of the scaffold 2,7-diaza-1,2,3,6,7,8-hexahydropyrene was developed. LÄS MER

  5. 4. Control of Aryne Capture Regioselectivity via Fluoroboronate-induced Distortion

    Författare :Matic Hribersek; Lukasz Pilarski; Carl Johan Wallentin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Arynes are valued as extremely versatile electrophilic intermediates. Control over the regioselectivity with which arynes react is typically achieved using comparatively simple and/or chemically inutile substituents close to the reactive triple bond. LÄS MER

  7. 5. Isocyanates and Amines – Sampling and Analytical Procedures

    Författare :Åsa Marand; Gunnar Skarping; Marianne Dalene; Daniel Karlsson; Roy Rando; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Isocyanates; Amines; Polyurethane; Air sampling; Industrial hygiene; Mass spectrometry; Liquid chromatography; Chemiluminescence; Analytical chemistry; Analytisk kemi;

    Sammanfattning : This thesis covers sampling and analytical procedures for isocyanates (R-NCO) and amines (R-NH2), two kinds of chemicals frequently used in association with the polymeric material polyurethane (PUR). Exposure to isocyanates may result in respiratory disorders and dermal sensitisation, and they are one of the main causes of occupational asthma. LÄS MER