Korn, vatten, humle och jäst är råvarorna för att göra ett gott öl. Innan man kan använda kornet blöts det i vatten och får ligga under värme för att gro. Detta kallas mältning och enzymet för att ombilda stärkelse i kornet till socker bildas. I kölnan torkas malten (kornet) med varmluft och transporteras till bryggeriet för bryggning. Malten krossas och blandas med vatten till en mäsk som värms upp. Detta är mäskningen där enzymet ombildar stärkelse till socker. När man silat blandningen, som nu kallas vört, kokas den kraftigt tillsammans med humlen som ger ölet smak. Sedan silar man bort humleresterna. Vörten går vidare till jäsning där de förjäsbara sockerarterna omvandlas till alkohol och när ölet jäst färdigt måste det lagras en tid, beroende på doft och smak. Slutligen filtrerar man ölet och tappar det på flaskor, burkar eller fat. Samtidigt pastöriserar man ölet dvs. tar kål på jästresterna och andra organismer som kan skada ölet.

This thesis deals with studies of on-line electrochemistry electrospray ionisation mass spectrometry (EC/ESI-MS). It is shown that the use of EC/ESI-MS demands optimal coupling characteristics. Pre-concentration and desalting, due to matrix exchange, were demonstrated for the model substance 1-hexanethiol in an EC/ESI-MS setup. The setup was also used for investigations of the oxidation states of the manganese complex [Mn2(bpmp)(µ-OAc)2][ClO4], where bpmp is a 2,6-bis[[N,N-di(2-pyridylmethyl)amino]methyl]-4-methylphenol compound. The manganese complex, which is relevant to artificial photosynthesis, was found to be a good model compound for the EC/ESI-MS studies, thanks to its many oxidation states. For the first time, the presence of the Mn(III,IV) state of the manganese complex was demonstrated in the studies. During the experimental work, the importance of the electrode positioning within the electrochemical cell was investigated. Different EC cell configurations were studied using the manganese complex as a model substance. It was clearly shown that the EC cell design influences the distribution between the peaks in the mass spectra - not only for manganese complexes and Olsalazine but also for 4-chloroaniline. A previously unknown comproportionation reaction was found for 4-chloroaniline involving the oxidised dimer, 4-[(4-chlorophenyl)imino]-2,5-cyclohexadien-1-imine. This reaction explained the unexpected presence of the signal due to the reduced dimer, 4-amino-4'-chlorodiphenylamine, in the mass spectra. Furthermore, it was shown that EC/ESI-MS was successful in conjunction with miniaturised gold wire electrodes in a PDMS chip within which dopamine was oxidised with a conversion efficiency of 30%. The oxidation products of dopamine were detected after 0.6-1.2 seconds for 1.0 and 0.5 µl/min, respectively. The combination of electrochemically controlled solid-phase extraction (EC-SPE) with ESI-MS was found to be less straightforward than detecting anions pre-concentrated on a polypyrrole coated electrode with EC-SPE/ICP-MS. The on-line combination of liquid chromatography with EC/ESI-MS/MS for studying antioxidants in yellow onion extracts was shown to be fast and a relatively easy complement to classical antioxidant activity determinations.

This thesis addresses structure and reactivity of polypeptide catalysts in reactions that mimic the hydrolysis of RNA and DNA. A designed helix-loop-helix motif was used as a scaffold where the amino acid residues were systematically varied. The reactivity of a previously reported catalyst, HNI, was evaluated and the catalytic residues of the active site, Arg and His, were replaced in a stepwise manner by the artificial amino acid Gcp. Gcp has a guanidinocarbonyl pyrrole side chain, i.e. a side chain that mimics that of Arg but with a lower pKa. Gcp was used to replace both histidine and arginine in the polypeptide catalysts and was able to bind phosphate as well as carry out general base catalysis. The parent polypeptide HNI was shown to catalyse phosphoryl transfer reactions of phosphodiesters in an active site with two His and two Arg residues. The performance of the active site was improved by the introduction of two Tyr residues to form the catalyst HJ1 designed to provide nucleophilic catalysis in the hydrolysis of DNA model substrates. To improve the catalytic activity beyond that of HJI, Gcp was introduced to replace Arg and His residues in the HN1 scaffold. The designed catalyst JL3 was capable of a 150-fold rate enhancement compared to HNI in the reaction of the substrate HPNP, representing the first step in RNA hydrolysis. Mechanistic studies of JL3 catalysis suggested that the pKa value of the Gcp residue in the folded polypeptides was around 5. In combination with the observation of a solvent kinetic isotope effect of 1.7 the Gcp residue was proposed to provide general base catalysis and transition state stabilisation in the reaction of uridine 3′-2,2,2-trichloroethylphosphate, a realistic RNA model with a leaving group pKa of 12.5. The JL3 polypeptide catalyst followed saturation kinetics with a kcat/KM of 1.08 x 10-3 M-1s-1. The introduction of a designed photoswitchable amino acid in a catalytic polypeptide allowed the activity of the polypeptide in the reaction with an activated ester to be under photochemical control. Photoisomerization of this switch altered the structure of the polypeptide and affected the catalytic activity of the polypeptide catalyst. The chemical synthesis of designed molecules expands the amino acid alphabet and makes it possible to downsize enzymatic functions. It opens up possibilities for the production of novel biocatalysts that can catalyse natural as well as non-natural reactions.

The aim of this thesis was to develop analytical methods for measuring antimalarial drugs in biological fluids. Solid phase extraction (SPE) was used for the enrichment and purification of the drugs. Automatic extraction procedures using a SPE robot were developed to reduce the workload for the analyst and to minimize variations in the extraction procedure. Liquid chromatography (LC) with either UV or mass spectrometric (MS) detection was used to determine sample concentrations. Determination of Pyronaridine in whole blood utilised a weak cation exchanger to extract Pyronaridine from blood. To improve LC separation between Pyronaridine and the internal standard, ion-pairing was utilized. For the simultaneous quantification of the highly lipophilic Atovaquone and the strong basic drug Proguanil with metabolites, a novel mixed mode solid phase extraction column was used. It combines the properties of a carboxylic acid (CBA) column and a non-polar octyl-silica (C8) column to extract the compounds from plasma; it also required a gradient LC separation. Stability is an important factor when developing new methods. A new approach was used to evaluate the stability of Amodiaquine in blood and plasma. This included the use of a stability marker, a stable compound which was added together with Amodiaquine when preparing the stability samples. This eliminated between-run variations and variations associated with preparation of new stock solutions. Lumefantrine (LF) is one of the active components in a new drug combination recommended by the World Health Organization as a replacement for older drugs which have lost their effect. The first of the two methods described for this compound is the determination of LF and a possible metabolite in plasma with a calibration range suitable for pharmacokinetic studies. In the second method, a capillary sampling technique is used where the blood is dried on a sampling paper and sent to the laboratory where the extraction and determination of LF concentrations take place. This method facilitates sample collection and will enable drug efficacy studies conducted in rural settings. To monitor a current change in treatment policy and self medication, a screening assay was developed. Its purpose is to be a complement to interviewing patients about their previous medication (in the previous few weeks) and to detect some of the more common drugs which might have been used. / Paper 6. as Manuscript

This thesis is mainly focused on the development of new palladium catalyzed transformations using so-called “pincer” complexes. These complexes were applied as catalysts in two important areas of organometallic chemistry: substitution of propargylic substrates by dimetallic reagents; and allylation of aldehydes and imines by allylstannanes. In addition, this thesis includes studies on Lewis acid mediated cyclization reactions of allylsilanes with aldehydes. Pincer complex catalyzed substitution of various propargylic substrates could be achieved under mild conditions using tin and silicon based dimetallic reagents to obtain propargyl- and allenylstannanes and silanes. The regioselectivity of the substitution reaction strongly depends on the steric and electronic effects of the propargylic substrate. According to our mechanistic studies the key intermediate of the reaction is an organostannane (or silane) coordinated pincer complex. DFT modeling studies on the transfer of the trimethylstannyl functionality to the propargylic substrate revealed a novel mechanism, which is based on the unique topology of the pincer-complex catalysts. Our further studies showed that palladium pincer complexes can be employed as efficient catalysts for electrophilic allylic substitution of allylstannanes with aldehyde and imine substrates. In contrast to previous applications for electrophilic allylic substitutions via bis-allylpalladium complexes, this reaction involves mono-allylpalladium intermediates which were observed by 1H-NMR spectroscopy. The last chapter of this thesis is focused on Lewis-acid mediated cyclization of hydroxy functionalized allylsilanes, which afford tetrahydropyran derivatives with a high stereoselectivity.

The solid bimetallic compounds TtPt(CN)4(ClO4) and TtPt(CN)4(NO3) have been prepared by reactions between tetracyanoplatinate complex [Pt(CN)4]2- and aqueous solutions of Tl(ClO4)3 and Tl(NO3)3, respectively. The elemental analysis (N, C, H, Tl) of the compound has been carried out. The results of the analysis are reasonably consistent with the above compositions of the compounds. The bimetallic compounds have been characterized by IR and Raman spectroscopy as well as X-ray diffraction. IR and Raman spectra of the Tl-Pt compounds confirm presence of the perchlorate and nitrate counter ions in the solid. The presence of a direct Tl-Pt metal-metal bond in the compounds is confirmed by appearance of a strong vibrational band the low frequency region of the vibrational spectra.

Mayonnaise is a very popular food emulsion, traditionally made out of water, oil, hen egg yolk and vinegar, throughout the world. However, the quality is often reduced by separation when exposed to environmental stress, such as freeze-thawing which is an issue during transportation through regions of varying climates. The egg yolk proteins in the mayonnaise fail to keep the emulsion stable, thus limiting the freeze-thaw stability for longer time periods. Starches which are hydrophobically modified by octenyl succinic anhydride (OSA-starch) could generate a more freeze-thaw stable emulsion due to their higher molecular weight which generates a thicker layer on the oil droplets if adsorbed. The purpose of this master thesis was to investigate how freeze-thaw stability in mayonnaise could be increased and whether OSA-starch could provide a stabilizing effect in this context. The different parameters investigated included the size of the tubes in which the emulsions were frozen, pH at the time of emulsification, the amount and type of oil, preprocessing and amount of OSA-starch as well as the amount and type of egg yolk powder. Emulsions were prepared according to a standardized method, freeze-thawed and analyzed visually and in a microscope. The surface load of OSA-starch and egg yolk proteins at the interface of emulsions was determined according to the method of Aman (1994) and with BCA protein assay. Large variations were observed, thus limiting the possibility to draw conclusions from these results.Mayonnaise with rapeseed oil showed lower freeze-thaw stability than sunflower oil, most likely because of its tendency to form large ƒÀ-crystals in combination with having a higher degree of solid fat at -25‹C. Decreased oil content in mayonnaise generated higher freeze-thaw stability, probably because of lower collision frequency of the oil droplets. The size of the tubes used in this study did not appear to affect the freeze-thaw stability. An emulsion prepared at pH 3.5 showed a higher surface load of OSA-starch and egg yolk proteins but no increased freeze-thaw stability. This could potentially be explained with the surface layer being too thin or that OSA-starch just does not increase the freeze-thaw stability. An emulsion prepared with OSA-starch as the sole emulsifier demonstrated an increased surface load of OSA-starch at both pH 6.5 and 3.5 and maintained freeze-thaw stable after 7 days in the freezer. One possible explanation to these results is the lack of competitive adsorption from egg yolk proteins and the fact that the system is less complex with fewer components. In conclusion, a 56 % emulsion with OSA-starch as the sole emulsifier resulted in a very stable emulsion. It is without doubt that o/w emulsions stabilized with egg yolk is a very complex system. More research concerning egg yolk and its behavior during emulsifying and freeze-thawing of o/w emulsions is of great interest as it could generate new solutions and innovations in the production of food emulsions.

No description available.

Fragment based lead discovery (FBLD), where libraries of small fragments are screened andlater on developed to lead compounds, is an alternative to the classical drug discovery methods such as high trough-put screening. Weak affinity chromatography (WAC) is a new promising approach to the screening process of FBLD. WAC is performed by injections of fragments onto a high performance liquid chromatography (HPLC) column in which a protein is immobilized to a silica support. The retention of the injected fragments is correlated to the binding affinity of the fragments towards the immobilized protein. Immobilization capacity of three different silica materials with varying pore size (Kromasil240 Å, Nucleosil 1000 Å and Kromasil 300 Å) was evaluated by immobilization of trypsin. Retention of benzamidines on the trypsin columns was evaluated with different mobile phases. Contribution of non-specific binding in the interaction between the 4-aminobenzamidine and thrombin was estimated by frontal chromatography on a capillary columnusing PBS and PBS/acetonitrile as mobile phases. This study showed that the Kromasil 300 Å had a superior immobilization capacity of trypsin compared to the Kromasil 240 Å andthe Nucleosil 1000 Å (100 mg compared to 87.4 mg and 15.1 mg trypsin/g silica, respectively). However, the Nucleosil 1000 Å might be a more suitable support for the immobilization of larger proteins. Adding 5 % methanol or acetonitrile to the mobile phase resulted in a significant (p < 0.05) decreased retention of benzamidine fragments on the trypsin 240 Å column. Non-specific binding between thrombin and 4-ABA was not statistically significantly altered when 5 % acetonitrile was added to the mobile phase.

<p>The solid bimetallic compounds TtPt(CN)₄(ClO₄) and TtPt(CN)₄(NO₃) have been prepared by reactions between tetracyanoplatinate complex [Pt(CN)4]2- and aqueous solutions of Tl(ClO₄)₃ and Tl(NO₃)₃, respectively. The elemental analysis (N, C, H, Tl) of the compound has been carried out. The results of the analysis are reasonably consistent with the above compositions of the compounds. The bimetallic compounds have been characterized by IR and Raman spectroscopy as well as X-ray diffraction. IR and Raman spectra of the Tl-Pt compounds confirm presence of the perchlorate and nitrate counter ions in the solid. The presence of a direct Tl-Pt metal-metal bond in the compounds is confirmed by appearance of a strong vibrational band the low frequency region of the vibrational spectra.</p>