Determination of the critical activities of a public-private intermediary organization with the help of value chain analysis

Tämän diplomityön tavoitteena oli selvittää arvoketjuanalyysin avulla toiminnot, joilla voittoatavoittelemattoman, julkisen osakeyhtiön toimintaa voitaisiin kuvata. Tarkoituksena oli selvittää mainitut toiminnot yleisesti ja luoda malli kohdeyrityksen arvoketjusta ja sen toiminnoista. Tutkielma jakautuu teoreettiseen ja empiiriseen osaan. Ensimmäinen pohjautuu aikaisempaan tutkimukseen ja kirjallisuuteen sidosryhmistä, arvon muodostumisesta ja arvoketjuanalyysistä. Jälkimmäinen on laadullista tapaustutkimusta. Empiriassa mallinnettiin Lappeenranta Innovation Oy:nsisäisiä toimintoja ja sidosryhmien odotuksia. Empiirinen tutkimus perustui kohdeyrityksen omistajille ja henkilöstölle tehtyihin haastatteluihin sekä yrityksen toiminnan päivittäiseen seurantaan. Johtopäätöksenätodettiin, että julkisen, voittoa tavoittelemattoman yrityksen toiminnot on mahdollista kuvata arvoketjuanalyysin avulla. Alan ja yrityksen asettamat erityispiirteet toivat haasteita määrittelylle, mutta silti arvoketju antoi selkeän tavan kohdeyrityksen toimintojen mallintamiselle.

Comparative genome analysis of Pseudomonas knackmussii B13, the first bacterium known to degrade chloroaromatic compounds.

Pseudomonas knackmussii B13 was the first strain to be isolated in 1974 that could degrade chlorinated aromatic hydrocarbons. This discovery was the prologue for subsequent characterization of numerous bacterial metabolic pathways, for genetic and biochemical studies, and which spurred ideas for pollutant bioremediation. In this study, we determined the complete genome sequence of B13 using next generation sequencing technologies and optical mapping. Genome annotation indicated that B13 has a variety of metabolic pathways for degrading monoaromatic hydrocarbons including chlorobenzoate, aminophenol, anthranilate and hydroxyquinol, but not polyaromatic compounds. Comparative genome analysis revealed that B13 is closest to Pseudomonas denitrificans and Pseudomonas aeruginosa. The B13 genome contains at least eight genomic islands [prophages and integrative conjugative elements (ICEs)], which were absent in closely related pseudomonads. We confirm that two ICEs are identical copies of the 103 kb self-transmissible element ICEclc that carries the genes for chlorocatechol metabolism. Comparison of ICEclc showed that it is composed of a variable and a 'core' region, which is very conserved among proteobacterial genomes, suggesting a widely distributed family of so far uncharacterized ICE. Resequencing of two spontaneous B13 mutants revealed a number of single nucleotide substitutions, as well as excision of a large 220 kb region and a prophage that drastically change the host metabolic capacity and survivability.

In silico pathway reconstruction: Iron-sulfur cluster biogenesis in Saccharomyces cerevisiae

Background: Current advances in genomics, proteomics and other areas of molecular biology make the identification and reconstruction of novel pathways an emerging area of great interest. One such class of pathways is involved in the biogenesis of Iron-Sulfur Clusters (ISC). Results: Our goal is the development of a new approach based on the use and combination of mathematical, theoretical and computational methods to identify the topology of a target network. In this approach, mathematical models play a central role for the evaluation of the alternative network structures that arise from literature data-mining, phylogenetic profiling, structural methods, and human curation. As a test case, we reconstruct the topology of the reaction and regulatory network for the mitochondrial ISC biogenesis pathway in S. cerevisiae. Predictions regarding how proteins act in ISC biogenesis are validated by comparison with published experimental results. For example, the predicted role of Arh1 and Yah1 and some of the interactions we predict for Grx5 both matches experimental evidence. A putative role for frataxin in directly regulating mitochondrial iron import is discarded from our analysis, which agrees with also published experimental results. Additionally, we propose a number of experiments for testing other predictions and further improve the identification of the network structure. Conclusion: We propose and apply an iterative in silico procedure for predictive reconstruction of the network topology of metabolic pathways. The procedure combines structural bioinformatics tools and mathematical modeling techniques that allow the reconstruction of biochemical networks. Using the Iron Sulfur cluster biogenesis in S. cerevisiae as a test case we indicate how this procedure can be used to analyze and validate the network model against experimental results. Critical evaluation of the obtained results through this procedure allows devising new wet lab experiments to confirm its predictions or provide alternative explanations for further improving the models.

Synthesis of the two isomers of the potential sex pheromone of Thaumetopoea pityocampa (Lepidoptera, Notodontidae) and related model compounds

The synthesis of the major component of the sex pheromone secretion of the processionary moth, Tkawnztopoeja pltyocampa (Denis and Schiff.) (Lepidoptera, Notodontidae), (Z)-13-hexadecen-ll-ynyl acetate (1), the corresponding (E)-isomer (2) and the four structurally related model compounds (Z⁄E,Z,Z)-5,9,13-hexadecatrienyl acetate (3), (Z⁄E,Z,Z)-3,7,ll-hexadecatrienyl acetate (4), (Z⁄E,E,Z)-7,9,13-hexadecatrienyl acetate (5) and (Z)-7-hexadecen-5-ynyl acetate (6) is described.

Effect of water velocity on the uptake of polychlorinatedd biphenyls (PCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers: an assessment of the efficiency of performance reference compounds (PRCs) in river-like flow conditions

One aim of this study is to determine the impact of water velocity on the uptake of indicator polychlorinated biphenyls (iPCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers. A second aim is to assess the efficiency of performance reference compounds (PRCs) to correct for the impact of water velocity. SR and LDPE samplers were spiked with 11 or 12 PRCs and exposed for 6 weeks to four different velocities (in the range of 1.6 to 37.7 cm s−1) in river-like flow conditions using a channel system supplied with river water. A relationship between velocity and the uptakewas found for each iPCB and enables to determine expected changes in the uptake due to velocity variations. For both samplers, velocity increases from 2 to 10 cm s−1, 30 cm s−1 (interpolated data) and 100 cm s−1 (extrapolated data) lead to increases of the uptake which do not exceed a factor of 2, 3 and 4.5, respectively. Results also showed that the influence of velocity decreased with increasing the octanol-water coefficient partition (log Kow) of iPCBs when SR is used whereas the opposite effect was observed for LDPE. Time-weighted average (TWA) concentrations of iPCBs in water were calculated from iPCB uptake and PRC release. These calculations were performed using either a single PRC or all the PRCs. The efficiency of PRCs to correct the impact of velocity was assessed by comparing the TWA concentrations obtained at the four tested velocities. For SR, a good agreement was found among the four TWA concentrations with both methods (average RSD b 10%). Also for LDPE, PRCs offered a good correction of the impact of water velocity (average RSD of about 10 to 20%). These results contribute to the process of acceptance of passive sampling in routine regulatory monitoring programs.

Grx5 is a mitochondrial glutaredoxin required for the activity of iron/sulfur enzymes

Yeast cells contain a family of three monothiol glutaredoxins: Grx3, 4, and 5. Absence of Grx5 leads to constitutive oxidative damage, exacerbating that caused by external oxidants. Phenotypic defects associated with the absence of Grx5 are suppressed by overexpression ofSSQ1 and ISA2, two genes involved in the synthesis and assembly of iron/sulfur clusters into proteins. Grx5 localizes at the mitochondrial matrix, like other proteins involved in the synthesis of these clusters, and the mature form lacks the first 29 amino acids of the translation product. Absence of Grx5 causes: 1) iron accumulation in the cell, which in turn could promote oxidative damage, and 2) inactivation of enzymes requiring iron/sulfur clusters for their activity. Reduction of iron levels in grx5 null mutants does not restore the activity of iron/sulfur enzymes, and cell growth defects are not suppressed in anaerobiosis or in the presence of disulfide reductants. Hence, Grx5 forms part of the mitochondrial machinery involved in the synthesis and assembly of iron/sulfur centers.

A peroxisomal glutathione transferase of Saccharomyces cerevisiae is functionally related to sulfur amino acid metabolism

Saccharomyces cerevisiae cells contain three omega-class glutathione transferases with glutaredoxin activity (Gto1, Gto2, and Gto3), in addition to two glutathione transferases (Gtt1 and Gtt2) not classifiable into standard classes. Gto1 is located at the peroxisomes, where it is targeted through a PTS1-type sequence, whereas Gto2 and Gto3 are in the cytosol. Among the GTO genes, GTO2 shows the strongest induction of expression by agents such as diamide, 1-chloro-2,4-dinitrobenzene, tert-butyl hydroperoxide or cadmium, in a manner that is dependent on transcriptional factors Yap1 and/or Msn2/4. Diamide and 1-chloro-2,4-dinitrobenzene (causing depletion of reduced glutathione) also induce expression of GTO1 over basal levels. Phenotypic analyses with single and multiple mutants in the S. cerevisiae glutathione transferase genes show that, in the absence of Gto1 and the two Gtt proteins, cells display increased sensitivity to cadmium. A gto1-null mutant also shows growth defects on oleic acid-based medium, which is indicative of abnormal peroxisomal functions, and altered expression of genes related to sulfur amino acid metabolism. As a consequence, growth of the gto1 mutant is delayed in growth medium without lysine, serine, or threonine, and the mutant cells have low levels of reduced glutathione. The role of Gto1 at the S. cerevisiae peroxisomes could be related to the redox regulation of the Str3 cystathionine -lyase protein. This protein is also located at the peroxisomes in S. cerevisiae, where it is involved in transulfuration of cysteine into homocysteine, and requires a conserved cysteine residue for its biological activity.

Conjugation of a Ru(II) Arene Complex to Neomycin or to Guanidinoneomycin Leads to Compounds with Differential Cytotoxicities and Accumulation between Cancer and Normal Cells

A straightforward methodology for the synthesis of conjugates between a cytotoxic organometallic ruthenium(II) complex and amino- and guanidinoglycosides, as potential RNA-targeted anticancer compounds, is described. Under microwave irradiation, the imidazole ligand incorporated on the aminoglycoside moiety (neamine or neomycin) was found to replace one triphenylphosphine ligand from the ruthenium precursor [(η6-p-cym)RuCl(PPh3)2]+, allowing the assembly of the target conjugates. The guanidinylated analogue was easily prepared from the neomycin-ruthenium conjugate by reaction with N,N′-di-Boc-N″-triflylguanidine, a powerful guanidinylating reagent that was compatible with the integrity of the metal complex. All conjugates were purified by semipreparative high-performance liquid chromatography (HPLC) and characterized by electrospray ionization (ESI) and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and NMR spectroscopy. The cytotoxicity of the compounds was tested in MCF-7 (breast) and DU-145 (prostate) human cancer cells, as well as in the normal HEK293 (Human Embryonic Kidney) cell line, revealing a dependence on the nature of the glycoside moiety and the type of cell (cancer or healthy). Indeed, the neomycin-ruthenium conjugate (2) displayed moderate antiproliferative activity in both cancer cell lines (IC50 ≈ 80 μM), whereas the neamine conjugate (4) was inactive (IC50 ≈ 200 μM). However, the guanidinylated analogue of the neomycin-ruthenium conjugate (3) required much lower concentrations than the parent conjugate for equal effect (IC50 = 7.17 μM in DU-145 and IC50 = 11.33 μM in MCF-7). Although the same ranking in antiproliferative activity was found in the nontumorigenic cell line (3 2 > 4), IC50 values indicate that aminoglycoside-containing conjugates are about 2-fold more cytotoxic in normal cells (e.g., IC50 = 49.4 μM for 2) than in cancer cells, whereas an opposite tendency was found with the guanidinylated conjugate, since its cytotoxicity in the normal cell line (IC50 = 12.75 μM for 3) was similar or even lower than that found in MCF-7 and DU-145 cancer cell lines, respectively. Cell uptake studies performed by ICP-MS with conjugates 2 and 3 revealed that guanidinylation of the neomycin moiety had a positive effect on accumulation (about 3-fold higher in DU-145 and 4-fold higher in HEK293), which correlates well with the higher antiproliferative activity of 3. Interestingly, despite the slightly higher accumulation in the normal cell than in the cancer cell line (about 1.4-fold), guanidinoneomycin-ruthenium conjugate (3) was more cytotoxic to cancer cells (about 1.8-fold), whereas the opposite tendency applied for neomycin-ruthenium conjugate (2). Such differences in cytotoxic activity and cellular accumulation between cancer and normal cells open the way to the creation of more selective, less toxic anticancer metallodrugs by conjugating cytotoxic metal-based complexes such as ruthenium(II) arene derivatives to guanidinoglycosides.

Metabolic origin of δ15N values in nitrogenous compounds from Brassica napus L. leaves

Nitrogen isotope composition (δ15N) in plant organic matter is currently used as a natural tracer of nitrogen acquisition efficiency. However, the δ15N value of whole leaf material does not properly reflect the way in which N is assimilated because isotope fractionations along metabolic reactions may cause substantial differences among leaf compounds. In other words, any change in metabolic composition or allocation pattern may cause undesirable variability in leaf δ15N. Here, we investigated the δ15N in different leaf fractions and individual metabolites from rapeseed (Brassica napus) leaves. We show that there were substantial differences in δ15N between nitrogenous compounds (up to 30 ) and the content in (15N enriched) nitrate had a clear influence on leaf δ15N. Using a simple steady-state model of day metabolism, we suggest that the δ15N value in major amino acids was mostly explained by isotope fractionation associated with isotope effects on enzyme-catalysed reactions in primary nitrogen metabolism. δ15N values were further influenced by light versus dark conditions and the probable occurrence of alternative biosynthetic pathways. We conclude that both biochemical pathways (that fractionate between isotopes) and nitrogen sources (used for amino acid production) should be considered when interpreting the δ15N value of leaf nitrogenous compounds

Antifungal activity of compounds targeting the Hsp90-calcineurin pathway against various mould species.

OBJECTIVES: Invasive mould infections are associated with a high mortality rate and the emergence of MDR moulds is of particular concern. Calcineurin and its chaperone, the heat shock protein 90 (Hsp90), represent an important pathway for fungal virulence that can be targeted at different levels. We investigated the antifungal activity of compounds directly or indirectly targeting the Hsp90-calcineurin axis against different mould species. METHODS: The in vitro antifungal activity of the anticalcineurin drug FK506 (tacrolimus), the Hsp90 inhibitor geldanamycin, the lysine deacetylase inhibitor trichostatin A and the Hsp70 inhibitor pifithrin-μ was assessed by the standard broth dilution method against 62 clinical isolates of Aspergillus spp. and non-Aspergillus moulds (Mucoromycotina, Fusarium spp., Scedosporium spp., Purpureocillium/Paecilomyces spp. and Scopulariopsis spp.) RESULTS: FK506 had variable antifungal activity against different Aspergillus spp. and was particularly active against Mucor spp. Geldanamycin had moderate antifungal activity against Fusarium spp. and Paecilomyces variotii. Importantly, trichostatin A had good activity against the triazole-resistant Aspergillus ustus and the amphotericin B-resistant Aspergillus terreus as well as the MDR Scedosporium prolificans. Moreover, trichostatin A exhibited synergistic interactions with caspofungin against A. ustus and with geldanamycin against Rhizopus spp. for which none of the other agents showed activity. Pifithrin-μ exhibited little antifungal activity. CONCLUSIONS: Targeting the Hsp90-calcineurin axis at different levels resulted in distinct patterns of susceptibility among different fungal species. Lysine deacetylase inhibition may represent a promising novel antifungal strategy against emerging resistant moulds.

DIETARY FIBRE CONTENT, PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN SOURSOPS (Annona muricata L.)

ABSTRACT Healthy eating is associated with the consumption of fruits, which are notable for their beneficial effects on human health. The aim of this study was to evaluate the proximate composition, composition of fibers and components with antioxidant activity in soursops varieties Crioula, Lisa and Morada of physiological maturity (PM) and mature (M). The protein, lipid and moisture contents did not differ between soursop varieties, but the ash contents were higher in the Morada-PM (0.56%±0.03) and the Morada-M (0.82%±0.10) varieties. The Crioula-M variety showed higher levels of total dietary fibre (5.76%±0.12). The Lisa-M variety showed higher levels of insoluble dietary fibre (4.46%±0.00). The Lisa-M variety also showed a higher level of phenolic compounds (284.25 mg gallic acid/100 g of soursop pulp), differing significantly (p <0.05) from the Crioula-PM soursop (154.40 mg of gallic acid/100 g of soursop pulp). Under the DPPH• system, the soursops that showed highest antioxidant activity were the Crioula-M (EC50 of 156.40 g.g DPPH-1) and the Crioula-PM (EC50 of 162.41 g.g DPPH-1), which differed significantly from the Morada soursops. The results suggest that the consumption of soursops is useful for increasing concentrations of bioactive compounds and dietary fibre.

Gas-phase photocatalytic oxidation of volatile organic compounds

Substances emitted into the atmosphere by human activities in urban and industrial areas cause environmental problems such as air quality degradation, respiratory diseases, climate change, global warming, and stratospheric ozone depletion. Volatile organic compounds (VOCs) are major air pollutants, emitted largely by industry, transportation and households. Many VOCs are toxic, and some are considered to be carcinogenic, mutagenic, or teratogenic. A wide spectrum of VOCs is readily oxidized photocatalytically. Photocatalytic oxidation (PCO) over titanium dioxide may present a potential alternative to air treatment strategies currently in use, such as adsorption and thermal treatment, due to its advantageous activity under ambient conditions, although higher but still mild temperatures may also be applied. The objective of the present research was to disclose routes of chemical reactions, estimate the kinetics and the sensitivity of gas-phase PCO to reaction conditions in respect of air pollutants containing heteroatoms in their molecules. Deactivation of the photocatalyst and restoration of its activity was also taken under consideration to assess the practical possibility of the application of PCO to the treatment of air polluted with VOCs. UV-irradiated titanium dioxide was selected as a photocatalyst for its chemical inertness, non-toxic character and low cost. In the present work Degussa P25 TiO2 photocatalyst was mostly used. In transient studies platinized TiO2 was also studied. The experimental research into PCO of following VOCs was undertaken: - methyl tert-butyl ether (MTBE) as the basic oxygenated motor fuel additive and, thus, a major non-biodegradable pollutant of groundwater; - tert-butyl alcohol (TBA) as the primary product of MTBE hydrolysis and PCO; - ethyl mercaptan (ethanethiol) as one of the reduced sulphur pungent air pollutants in the pulp-and-paper industry; - methylamine (MA) and dimethylamine (DMA) as the amino compounds often emitted by various industries. The PCO of VOCs was studied using a continuous-flow mode. The PCO of MTBE and TBA was also studied by transient mode, in which carbon dioxide, water, and acetone were identified as the main gas-phase products. The volatile products of thermal catalytic oxidation (TCO) of MTBE included 2-methyl-1-propene (2-MP), carbon monoxide, carbon dioxide and water; TBA decomposed to 2-MP and water. Continuous PCO of 4 TBA proceeded faster in humid air than dry air. MTBE oxidation, however, was less sensitive to humidity. The TiO2 catalyst was stable during continuous PCO of MTBE and TBA above 373 K, but gradually lost activity below 373 K; the catalyst could be regenerated by UV irradiation in the absence of gas-phase VOCs. Sulphur dioxide, carbon monoxide, carbon dioxide and water were identified as ultimate products of PCO of ethanethiol. Acetic acid was identified as a photocatalytic oxidation by-product. The limits of ethanethiol concentration and temperature, at which the reactor performance was stable for indefinite time, were established. The apparent reaction kinetics appeared to be independent of the reaction temperature within the studied limits, 373 to 453 K. The catalyst was completely and irreversibly deactivated with ethanethiol TCO. Volatile PCO products of MA included ammonia, nitrogen dioxide, nitrous oxide, carbon dioxide and water. Formamide was observed among DMA PCO products together with others similar to the ones of MA. TCO for both substances resulted in the formation of ammonia, hydrogen cyanide, carbon monoxide, carbon dioxide and water. No deactivation of the photocatalyst during the multiple long-run experiments was observed at the concentrations and temperatures used in the study. PCO of MA was also studied in the aqueous phase. Maximum efficiency was achieved in an alkaline media, where MA exhibited high fugitivity. Two mechanisms of aqueous PCO – decomposition to formate and ammonia, and oxidation of organic nitrogen directly to nitrite - lead ultimately to carbon dioxide, water, ammonia and nitrate: formate and nitrite were observed as intermediates. A part of the ammonia formed in the reaction was oxidized to nitrite and nitrate. This finding helped in better understanding of the gasphase PCO pathways. The PCO kinetic data for VOCs fitted well to the monomolecular Langmuir- Hinshelwood (L-H) model, whereas TCO kinetic behaviour matched the first order process for volatile amines and the L-H model for others. It should be noted that both LH and the first order equations were only the data fit, not the real description of the reaction kinetics. The dependence of the kinetic constants on temperature was established in the form of an Arrhenius equation.

Blood monitoring of perfluorocarbon compounds (F-tert-butylcyclohexane, perfluoromethyldecalin and perfluorodecalin) by headspace-gas chromatography-tandem mass spectrometry.

A headspace-gas chromatography-tandem mass spectrometry (HS-GC-MS/MS) method for the trace measurement of perfluorocarbon compounds (PFCs) in blood was developed. Due to oxygen carrying capabilities of PFCs, application to doping and sports misuse is speculated. This study was therefore extended to perform validation methods for F-tert-butylcyclohexane (Oxycyte(®)), perfluoro(methyldecalin) (PFMD) and perfluorodecalin (PFD). The limit of detection of these compounds was established and found to be 1.2µg/mL blood for F-tert-butylcyclohexane, 4.9µg/mL blood for PFMD and 9.6µg/mL blood for PFD. The limit of quantification was assumed to be 12µg/mL blood (F-tert-butylcyclohexane), 48µg/mL blood (PFMD) and 96µg/mL blood (PFD). HS-GC-MS/MS technique allows detection from 1000 to 10,000 times lower than the estimated required dose to ensure a biological effect for the investigated PFCs. Thus, this technique could be used to identify a PFC misuse several hours, maybe days, after the injection or the sporting event. Clinical trials with those compounds are still required to evaluate the validation parameters with the calculated estimations.

Kaivosteollisuudessa syntyvän kipsin hyödyntäminen

Diplomityön tarkoituksena oli tutkia ja kehittää käyttökohde kaivosteollisuudessa syntyvälle märälle kipsisivuvirralle, joka sisältää metalliepäpuhtauksina alumiinia, rautaa ja mangaania ja jonka määrä on noin 1 000 000 t/a. Kirjallisuuden pohjalta tutkittiin aluksi mahdollisuutta hyödyntää kipsiaines asfaltti- ja sementtiteollisuuden raaka-aineena. Sementin joukkoon lisätään tavallisesti noin 5 p-% kipsiä, mutta harvinaisimpiin sementtilaatuihin sitä voidaan lisätä jopa 30 p-%. Tästä huolimatta vain pieni osa tutkimuksen kohteessa syntyvästä kipsisivuvirrasta voitaisiin hyödyntää tässä sovelluksessa. Lisäksi kipsisivuvirran sisältämät epäpuhtaudet täytyisi poistaa tai saattaa inaktiiviseen muotoon. Myöskään sen kosteuspitoisuus ei saisi olla suuri. Näin ollen tämän kipsisivuvirran hyödyntäminen asfaltti- ja sementtiteollisuuden lisäaineena ei ole mahdollista Seuraavaksi harkittiin kipsin kierrättämistä, jolloin yhtenä vaihtoehtona oli hajottaa kipsi termisesti rikkioksideiksi ja valmistaa niistä rikkihappoa. Taloudellisista syistä hajoamistuotteen on oltava rikkitrioksidia, josta voitaisiin veteen imeyttämällä valmistaa rikkihappoa. Kipsin hajottaminen termovaa´alla osoitti, että kipsi vaatii noin 1400 ºC:n lämpötilan ja haihtuvat komponentit ovat H2O, SO ja SO2, muttei SO3. Alempien oksidien muuttaminen rikkihapoksi vaatisi katalyyttisen hapetuksen, mikä olisi käytännössä liian kallista. Toisena vaihtoehtona kipsin kierrättämiseksi tutkittiin sen biologista pelkistämistä rikkivedyksi ja kalsiumhydroksidilietteeksi. Laboratoriossa Ca(OH)2-lietteestä valmistettiin hiilidioksidin avulla kalsiumkarbonaattia, jolloin päästiin 90 %:n kalsiumhydroksidin konversiossa. Lisäksi alumiinihydroksidi saatiin erotettua kipsilietteestä kokeellisesti hydrosyklonin avulla. Diplomityössä päädyttiin siihen, että sulfaatin biologinen pelkistäminen ja alumiinihydroksidin mekaaninen erotus jatkuvatoimisesti on varteenotettava vaihtoehto kipsisivuvirran hyödyntämiseksi.

Synthesis of Janus compounds for the recognition of G-U mismatched nucleobase pairs

The design and synthesis of two Janus-type heterocycles with the capacity to simultaneously recognize guanine and uracyl in G-U mismatched pairs through complementary hydrogen bond pairing is described. Both compounds were conveniently functionalized with a carboxylic function and efficiently attached to a tripeptide sequence by using solid-phase methodologies. Ligands based on the derivatization of such Janus compounds with a small aminoglycoside, neamine, and its guanidinylated analogue have been synthesized, and their interaction with Tau RNA has been investigated by using several biophysical techniques, including UV-monitored melting curves, fluorescence titration experiments, and 1H NMR. The overall results indicated that Janus-neamine/guanidinoneamine showed some preference for the +3 mutated RNA sequence associated with the development of some tauopathies, although preliminary NMR studies have not confirmed binding to G-U pairs. Moreover, a good correlation has been found between the RNA binding affinity of such Janus-containing ligands and their ability to stabilize this secondary structure upon complexation.