Sökning: "Helena Grennberg"
Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Helena Grennberg.
1. Development and mechanistic studies of palladium-catalysed oxidations of conjugated dienes and olefins : application to aerobic oxidations
Sammanfattning : .... LÄS MER
2. Chemistry of Carbon Nanostructures : Functionalization of Carbon Nanotubes and Synthesis of Organometallic Fullerene Derivatives
Sammanfattning : This thesis is based on two main parts. The first part concerns purification and functionalization of carbon nanotubes (papers I-III), and the second part is related to the synthesis of organometallic fullerene derivatives (papers IV-VII): Two oxidative methods involving aqueous nitric acid were compared with respect to their capability to introduce carboxylic groups into single walled carbon nanotubes, and several literature methods for esterification and amidation of these groups have been evaluated with focus on efficiency and reproducibility in forming covalently functionalized products soluble in organic media. LÄS MER
Sammanfattning : This thesis details various techniques and considerations for the purification of complex biomacromolecules. Initially an α-mannosidase from babaco fruit was purified using anion exchange-, lectin affinity- and size exclusion chromatography. LÄS MER
Sammanfattning : This thesis consists of seven research publications concerning (i) pKa studies of nucleobases in model nucleotides to understand why RNA duplexes are more stable than DNA duplexes (Paper I), (ii) the role of Me(T)-π interactions in the relative stability of DNA-RNA heteroduplexes (Paper II), (iii) pKa measurements in nucleotides with different 2′-substituents (paper III), (iv) a conformation study of constrained sugars and a pKa study of 1-thyminyl to reveal effect of sugar constraints on the pKa of the nucleobase (paper IV), (v) NMR and MD studies of 1′, 2′-oxetane constrained thymidine incorporated Dickerson Drew dodecamer (paper V), (vi) the sequence dependent pKa perturbation of 9-guaninyl moeity in single stranded (ss) DNA and RNA (paper VI), (vii) the non identical chemical nature of internucleotidic phosphates in (ss) RNA using 31P NMR (paper VI), and an alkaline hydrolysis study of phosphodiesters in ssRNAs (paper VII). The architecture of DNA and RNA molecules is determined by (a) hydrogen bonding (b) base stacking (c) a variety of additional non-covalent interactions. LÄS MER
Sammanfattning : This thesis is concerned with the synthesis and evaluation of regenerable chalcogen containing antioxidants. Variously substituted 2,3-dihydrobenzo[b]selenophene-5-ol antioxidants were evaluated in order to gain information about structure/reactivity-relationships. LÄS MER