Abstract Twenty-seven phosphine and six bipyridine ligands were synthesised and characterized. Additionally, a new route to the family of phosphine ligands via o-thioanisyldichlorophosphine was found. The phosphine ligands contain thiomethylphenyl, methoxyphenyl, dimethylaminophenyl, pyridyl, naphthyl and anthracenyl groups, and the bipyridine ligands thiomorpholine and piperidine groups. Metal complexes of 3-pyridyldiphenylphosphine, 6,6'-bis(methylthiomorpholine)-2,2'-bipyridine and 4,4'-dimethyl-6,6'-bis(methylthiomorpholine)-2,2'-bipyridine were prepared. Ligands and complexes were characterized by 1H-, 13C-, 31P- and two-dimensional HSQC-NMR spectroscopy, and crystal structures were determined for the ligands and two of the metal complexes. Tertiary phosphine ligands were prepared for catalytic purposes and tested in hydroformylation reaction at the Helsinki University of Technology and the University of Joensuu. Bipyridine ligands were designed for bimetallic coordination. The phosphine ligands cover a wide range of electronic and steric properties. The spectroscopic parameters and crystal structures were studied with the purpose of charting trends in the basicities and steric effects of the ligands.

Phosphorus release from sediments contributes significantly to high phosphorus level in lake water and provides nutrient support to promote algal growth. To speed up the recovery of eutrophic lakes, it is necessary to limit phosphorus release from sediments. Accurate sedimentary phosphorus fractionation is a strong basis for understanding phosphorus release from sediments. There are several techniques to study sedimentary phosphorus fractionation. Chemical sequential extraction (CSE) techniques are commonly used by industrial practitioners. However, it is doubtful that the P fractionation of the lake sediments studied using the Jensen and Thamdrup (1993) method is reliable. The reason is that the phosphorus fractions do not exactly correspond to the chemically defined compounds in the sequential phosphorus extraction. In order to further understand the Jensen and Thamdrup (1993) method, it is necessary to study P species in the supernatant and residue of each fraction. X-ray absorption near-edge structure (XANES) can provide direct information about the mineral phase of phosphorus in the sediments. Solution phosphorus nuclear magnetic resonance (31P NMR) reveals direct molecular and structural characterization of organic phosphorus in the sediments. This study enhanced the understanding of the Jensen and Thamdrup (1993) chemical sequential extraction method for studying the sedimentary phosphorus fractionation by using solution 31P NMR spectroscopy and phosphorus K-edge XANES spectroscopy. The research using the chemical sequential extraction indicated that inorganic P was dominant in all sediments samples. Also, it suggested that calcium-bound P accounted for the largest proportion of the total P in every sediments sample. The solution 31P NMR spectroscopy clearly identified orthophosphate, phytic acid, pyrophosphate, and polyphosphate in the sediments samples. The P K-edge XANES spectroscopy showed all of the sediments samples contained apatite and phytic acid. In addition, the study using the XANES identified apatite in the residue after the HCl extraction of Blackstrap #6; however it indicated no apatite in the supernatant of HCl fraction of both Blackstrap #3 and Pond #11.

Lignin, en av huvudkomponenterna i lignocellulosabiomassa, utgör en stor mängd av sidoströmen från massaindustrin. Lignin är aromatiska makromolekyler som förekommer i rikliga mängder i naturen och uppvisar unika antioxidant-, uv-skyddande, anti-ultravioletta, antikorrosiva och antimikrobiella egenskaper, etc. Ligninbaserade produkter är ännu inte kommersialiserade eftersom de är begränsade av den kemiska heterogeniteten hos lignin som separerats från olika råvaror och producerats i olika industriella processer. Istället förbränns lignin vanligtvis för värme- och elproduktion efter extraktion. Tillvägagångssätt för att bevara värdefulla egenskaper hos lignin och samtidigt övervinna begränsningar har blivit heta ämnen. I detta projekt genomfördes kemiska modifieringar av kraftlignin från olika naturliga råvaror, gran och eukalyptus, där fenolgrupperna ersattes av alkylgrupper med olika kedjelängder (kolnummer 1, 6 och 12). De kemiska strukturerna och de termiska egenskaperna hos kraftlignin studerades med en kombination av analytiska metoder. Egenskaperna hos två typer av tekniska kraftligniner och dess derivat undersöktes även för jämförelse. Resultaten visade att kemiskt modifierat lignin kan vara ett lovande råmaterial för förädlade produkter som till exempel ligninbaserade nanopartiklar. / Lignin, one of the major components in lignocellulose biomass, makes up a large amount of sidestream from the pulp industry. As an abundant feedstock of bio- originated aromatic macromolecules, lignin shows unique antioxidant, UV-protective, anticorrosive, and antimicrobial properties, etc. However, limited by the chemical heterogeneity of lignin separated from different bioresources and industrial procedures as well as its recalcitrance as macromolecules, lignin-based products are not yet commercialized, while lignin is commonly burnt for heat or power generation after extraction. Approaches of preserving valuable properties of lignin meanwhile overcoming limitations have become heated topics. In this project, chemical modifications of kraft lignin from different natural bio-origins, spruce and eucalyptus, were conducted, with alkyl groups of various chain lengths (carbon numbers 1, 6 and 12) substituting the phenolic groups. A combination of analytical methods for characterizing the chemical structures and thermal properties of kraft lignin and chemically modified kraft lignin were studied. Meanwhile, the characteristics of two kinds of technical kraft lignin and their derivatives were investigated for comparison. Results highlighted that chemically modified lignin could be a promising material to serve as a feedstock for value-added products such as lignin-based nanoparticles.

Thesis advisor: Mary F. Roberts / Thesis advisor: Steven D. Bruner / The bacterial phosphatidylinositol-specific phospholipase C (PI-PLC) from <italic>Bacillus thuringiensis</italic> is specifically activated by low concentrations of a non-substrate lipid, phosphatidylcholine (PC), presented as an interface. However, if the PC concentration in the interface is too high relative to substrate, the enzyme exhibits surface dilution inhibition. Understanding this bacterial enzyme, which shares many kinetic features with the larger and more complex mammalian PI-PLC enzymes, requires elucidating the mechanism for PC activation and inhibition. Various techniques were applied to study the interaction of the protein with vesicles composed of both the activator lipid PC and the substrate lipid (or a nonhydrolyzable analogue). Fluorescence correlation spectroscopy (FCS), used to monitor bulk partitioning of the enzyme on vesicles, revealed that both the PC and the substrate analogue are required for the tightest binding of the PI-PLC to vesicles. Furthermore, the tightest binding occurred at low mole fractions of substrate-like phospholipids. Field cycling <super>31</super>P NMR (fc-P-NMR) spin-lattice relaxation studies provided information on how bound protein affects the lipid dynamics in mixed substrate analogue/PC vesicles. The combination of the two techniques could explain the enzyme kinetic profile for the PC activation and surface dilution inhibition: small amounts of PC in an interface enhanced PI-PLC binding to substrate-rich vesicles while high fractions of PC tended to sequester the enzyme from the bulk of its substrate leading to reduced specific activity. FCS binding profiles of mutant proteins were particularly useful in determining if a specific mutation affected a single or both phospholipid binding modes. In addition, an allosteric PC binding site was identified by fc-P-NMR and site directed spin labeling. A proposed model for PC activation suggested surface-induced dimerization of the protein. Experiments in support of the model used cysteine mutations to create covalent dimers of this PI-PLC. Two of these disulfide linked dimers, formed from W242C or S250C, exhibited higher specific activities and tighter binding to PC surfaces. In addition, single molecule total internal reflection fluorescence microscopy was used to monitor the off-rate of PI-PLC from surface tethered vesicles, providing us with a direct measure of off-rates of the protein from different composition vesicles. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

In tundra, phosphorus (P) is an important macronutrient for plants and microorganisms. A major fraction of P exists as organic compounds in the topsoil which can be mineralized to bioavailable inorganic P. Since mineralization is positively related to temperature, climate warming is likely to increase P bioavailability but the extend of these changes may also depend on vegetation cover and soil properties. I assessed organic and inorganic P concentrations across an elevation and vegetation gradient in northern Sweden using one dimensional (1D) solution 31P nuclear magnetic resonance spectroscopy. I hypothesized that concentration of labile soil P will decrease with increasing elevation (decreasing temperature) and that soils with meadow vegetation will contain higher concentrations of labile P than heath soils. Concentration of labile P in the form of Resin-P and polyphosphates decreased with elevation whereas less labile orthophosphate monoesters increased. Across vegetation types, polyphosphates were more abundant in heath and meadow contained higher concentrations of monoesters. The inverse response of Resin-P and monoesters to elevation may be best explained by lowered organic P mineralization in colder climate. High concentrations of polyphosphates at the lowest elevation may indicate an increased presence of fungal communities associated with mountain birch forest. Heath seemed to be more dominated by fungal communities than meadow and higher concentration of monoesters in meadow indicated a higher soil sorption capacity. In a broader view, the results may suggest that a warmer climate increases mineralization of organic P in form of orthophosphate monoesters to more labile P forms. This effect might be enhanced by an upward movement of the tree line and might be more pronounced in heath than meadow soils due to a higher fungal activity.

Lignin är en restprodukt från massaindustrin som har stor potential för vidareanvändning i bland annat materialutveckling. För att utreda möjliga användningsområden för ett specifikt lignin är det viktigt att ha kunskap om ligninets molekylstruktur och bindningar. 31P-NMR spektroskopi kan användas som analysmetod för kvantifiering av hydroxylgrupperna hos lignin. Vid användning av 31P-NMR spektroskopi måste ligninprovet först derivatiseras med ett derivatiserings-reagens innehållande fosfor. Till analyserna behövs en lämplig intern standard för att kunna beräkna halten av de olika strukturelementen i lignin. RISE Research Institutes of Sweden ville se om det gick att komplettera analyserna av lignins struktur med hjälp av ett nytt derivatiserings-reagens, DR(I) (2-chloro-1,3,2-dioxaphospholane). Tidigare har derivatiserings-reagenset DR(II) (2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane) använts. Det nya derivatiserings-reagenset DR(I) har en liknande struktur men är en mindre molekyl och förväntades därför kunna analysera fler strukturelement som tidigare inte kunnat påvisas. Projektet har undersökt 10 olika interna standarder med DR(I) i syfte att hitta den bästa interna standarden. Den första som undersöktes är den som används med DR(II), N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine. Av de undersökta interna standarderna är tre tagna från tidigare litteratur och sex är tidigare helt obeprövade. Samtliga undersöktes både som blankprov och med ett utvalt barrveds-kraftlignin. N-hydroxy-1,8-naftalimid (intern standard 4) var bäst baslinjeupplöst men inte tillräckligt stabil för att kunna användas som intern standard. Bisfenol-A (intern standard 3) var den interna standard som var den mest stabila och alla stabilitetstest utfördes med denna interna standard som referens. Av de tidigare obeprövade interna standarderna är det endast N-hydroxysuccinimide (intern standard 5) som kan användas som intern standard, dock är den inte tillräckligt stabil. N-hydroxy-5-norborene-2,3-dicarboxylic acid imine (intern standard 1) ansågs vara den bäst lämpade interna standarden. Denna prövades med olika typer av kraftlignin; barrveds-kraftlignin, lövveds-kraftlignin samt ett blandlignin. Den undersöktes även med ”milled wood lignin”. För detta lignin var det uppenbart att den valda interna standarden inte var helt optimal. En annan intern standard med bättre baslinjeupplösning skulle vara ett bättre alternativ för ”milled wood lignin”. Relaxationstiden mättes även för intern standard 1 och de olika strukturerna i ligninet. RISE Research Institutes of Sweden kan använda DR(I) som komplement till den nuvarande analysen med DR(II) vid beräkning av mängden av de sekundära alifatiska grupperna. En uppdelning av de olika formerna (erythro och threo) av den vanligaste bindningen hos lignin, β-O-4-bindningen, går också att urskilja. Eftersom denna bindning bryts i sulfatmassaprocessen är signalen svag, vilket gör att en uppdelning av erythro och threo vid beräkningarna av hydroxylgrupperna inte är relevant. / Lignin is a residue from the pulp industry, which has great potential for further use, including material development. To investigate possible uses for a specific lignin, it is important to have knowledge of the lignin's molecular structure. 31P NMR spectroscopy can be used when quantifying the hydroxyl groups of lignin. When using 31P NMR spectroscopy, the lignin sample must be derivatized with a phosphorous reagent. The analysis requires an appropriate internal standard to calculate the amount of the different structural elements in lignin. RISE Research Institutes of Sweden wishes to complement the analyzes of lignin structures using a new derivatization reagent, DR(I) (2-chloro-1,3,2-dioxaphospholane). Previously, the derivatization reagent DR(II) (2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane) has been used. The new derivatization reagent DR(I) has a similar structure but is a smaller molecule. In this report, 10 different internal standards have been examined with DR(I) to find the most suitable one. The first internal standard, N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine, was used with DR(II). Three internal standards were from articles and six were previously unexamined. All of these were first tested as blanks without lignin and then with a selected softwood lignin. N-hydroxy-1,8-naphthalimide (internal standard 4) showed the best resolution but was not stable enough to be used as an internal standard. Bisphenol A (internal standard 3) was the most stable derivatized internal standard and the stability tests were performed with this internal standard as a reference. Of the previously unexamined internal standards, N-hydroxysuccinimide (internal standard 5) was the only appropriate internal standard to use. However, it was not as stable as N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine (internal standard 1), which was found to be the most suitable internal standard. N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine (internal standard 1) was examined with different types of kraft lignin; softwood kraft lignin, hardwood kraft lignin and a mixture kraft lignin. N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine was also investigated with "milled wood lignin". For ”milled wood lignin” it became obvious that the resolution of the selected internal standard can be improved. Another internal standard that has not been examined in this report could be a better option. The relaxation time was also determined for N-hydroxy-5-norbornene-2,3-dicarboxylic acid imine and the different hydroxyl groups of lignin. RISE Research Institutes of Sweden can use DR(I) in analysis of kraft lignin as a complement to the currently used method with DR(II) for calculating the amount of secondary aliphatic groups. A differentiation of erythro and threo of the most common binding (β-O-4) can also be noted with these lignins with DR(I). Since this bond is broken to a large extent in the kraft process, the signal is week. This means that when calculating the hydroxyl groups, a separation of erythro and threo is not relevant.

No description available.

No description available.

Wie in anderen Zellen sind auch bei Säugerspermien spezifische Lipide und Proteine der Zellmembran aufgrund ihrer heterogenen lateralen Verteilung in speziellen Domänen angereichert, die in unterschiedlichen räumlichen und zeitlichen Dimensionen existieren und der Zelle funktionale Variabilität ermöglichen. Aufgrund der fehlenden aktiven Proteinbiosynthese bietet dies den Spermien eine Möglichkeit, auf unterschiedliche Anforderungen zu reagieren. In der vorliegenden Arbeit wurden daher sogenannte detergenzresistente Membrandomänen (DRMs) aus Eberspermien unterschiedlicher Reifestadien präpariert und untersucht. Dabei stieg bereits in den Dichtegradienten mit zunehmender Reife die Dichte, bei der die opaleszenten Banden auftraten. Eine Analyse dieser mittels 31P-NMR zeigte mit zunehmender Reife eine Anreicherung an Glycerophosphatidylethanolamin und Phosphatidylinositol bei den Glycerophospholipiden, der Gehalt an Sphingomyelin hingegen nahm während der Nebenhodenreifung und auch nach der Ejakulation ab. Diese Veränderungen könnten auf eine Destabilisierung von Membrandomänen hindeuten, um eine Zusammenlagerung zu größeren Domänenclustern zu erleichtern, möglicherweise in Vorbereitung auf Kapazitation und Akrosomenreaktion. Zunächst werden die destabilisierten Membrandomänen jedoch durch die Anlagerung von Seminalplasmaproteinen geschützt, was vermutlich für das verringerte Lipid- zu Proteinverhältnis der DRMs bei Ejakulatspermien sorgt. Aufgrund der generellen Kälteempfindlichkeit von Eberspermien findet ihre Lagerung üblicherweise bei 16°C statt. Dies ist aus mikrobiologischer Sicht nachteilig gegenüber einer kälteren Lagerungstemperatur. Eine Untersuchung der Spermien von 64 Ebern zeigte jedoch bei 10% der Ejakulate eine individuum-spezifische Resistenz gegenüber der Lagerung bei 4°C. Die DRMs der kälteresistenten Spermien hatten einen erhöhten Anteil an langkettigen, mehrfach ungesättigten Fettsäuren, wie 31P-NMR und MALDI-TOF MS Analysen zeigten. / The lateral distribution of lipids and proteins in the plasma membrane is heterogeneous. Therefore specific lipids and proteins in membranes of mammalian spermatozoa are enriched in special domains of varying size and different time scales enabling the cell’s membrane functional variability. Being transcriptional inactive this is especially relevant for spermatozoa in responding to multiple challenges on their way to fertilization. Therefore so called detergent resistant membrane domains (DRMs) from boar spermatozoa of different developmental stages were investigated. Already in the sucrose density gradients differences were visible, so the opalescent bands of more maturated sperm had a higher density. An analysis of these bands by 31P-NMR showed an enrichment of glycerophosphatidylethanolamine and phosphatidylinositol during maturation and a decrease of sphingomyelin during maturation in the epididymis and even after ejaculation. This suggests destabilization of DRMs and hence of putative membrane domains. This could enable clustering to bigger membrane domain platforms in preparation for capacitation and acrosome reaction. First, however, seminal fluid proteins cover the spermatozoa protecting the membrane with the destabilized membrane domains. This could have led to the detected decrease of the lipid to protein ratio in DRMs of ejaculated sperm. Boar spermatozoa are sensitive to storage at cold temperatures and are therefore usually stored at 16°C, which is especially disadvantageous with regard to growing of bacteria. A screening of sperm from 64 boars showed a ratio of 10% individuals with cold resistant sperm which could be stored at 4°C without quality loss. The DRMs of cold resistant sperm had a higher proportion of longchained, polyunsaturated fatty acids, as shown by analysis with 31P-NMR und MALDI-TOF MS.

Phosphorus (P) is an essential element for life on our planet. It is central in numerous biochemical processes in terrestrial and aqueous ecosystems including food production; and it is the primary growth-limiting nutrient in some of the world’s biomes. The main source of P for use as agricultural fertilizer is mining of non-renewable mineral phosphate. In terrestrial ecosystems the main source is soil P, where the largest fraction is organic P, composed of many species with widely differing properties. This fraction controls the utilization of P by plants and microorganisms and influences ecosystem development and productivity. However, there is only scarce knowledge about the molecular composition of the organic P pool, about the processes controlling its bioavailability, and about its changes as soils develop. Therefore, the aim of this thesis was to develop robust solution- and solid-state 31P nuclear magnetic resonance spectroscopy (NMR) methods to provide molecular information about speciation of the organic P pool, and to study its dynamics in boreal and tropical soils. By studying humus soils of a groundwater recharge/discharge productivity gradient in a Fennoscandian boreal forest by solution- and solid-state NMR, it was found that P speciation changed with productivity. In particular, the level of orthophosphate diesters decreased with increasing productivity while mono-esters such as inositol phosphates increased. Because the use of solution NMR on conventional NaOH/EDTA extracts of soils was limited due to severe line broadening caused by the presence of paramagnetic metal ions, a new extraction method was developed and validated. Based on the removal of these paramagnetic impurities by sulfide precipitation, a dramatic decrease in NMR linewidths was obtained, allowing for the first time to apply modern multi-dimensional solution NMR techniques to soil extracts. Identification of individual soil P-species, and tracking changes in the organic P pools during soil development provided information for connecting P-speciation to bioavailability and ecosystem properties. Using this NMR approach we studied the transformation of organic P in humus soils along a chronosequence (7800 years) in Northern Sweden. While total P varied little, the composition of the soil P pool changed particularly among young sites, where also the largest shift in the composition of the plant community and of soil microorganisms was observed. Very old soils, such as found Africa, are thought to strongly adsorb P, limiting plant productivity. I used NMR to study the effect of scattered agroforestry trees on P speciation in two semi-arid tropical woodlands with different soil mineralogy (Burkina Faso). While the total P concentration was low, under the tree canopies higher amounts of P and higher diversity of P-species were found, presumably reflecting higher microbial activity. / <p>I delarbete III har titel och författaruppgifter förändrats.</p>