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  • 1.
    Ahlgren, Joakim
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Reitzel, Kasper
    Danielsson, Rolf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry.
    Gogoll, Adolf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Rydin, Emil
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Biogenic phosphorus in oligotropic mountain lake sediments: Differences in composition measured with NMR spectroscopy2006In: Water Research, no 40, p. 3705-3712Article in journal (Refereed)
  • 2.
    Ahlquist, Mårten
    et al.
    Technical University of Denmark.
    Nielsen, T E
    Le Quement, S
    Tanner, David
    Technical University of Denmark.
    Norrby, Per-Ola
    Technical Univeristy of Denmark.
    An experimental and theoretical study of the mechanism of stannylcupration of alpha, beta-acetylenic ketones and esters2006In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 12, no 10, p. 2866-2873Article in journal (Refereed)
    Abstract [en]

    The title reaction has been investigated by experimental and computational (DFT) techniques, and subsequently compared to the corresponding carbocupration reaction, with particular emphasis oil the stereoselectivity. For stannylcupration of an ynone substrate, only the anti-addition product is observed, whereas for the corresponding ynoate substrate, the stereoselectivity can be affected by the reaction conditions: in the presence of methanol as proton donor, the initial syn-addition product can be trapped, whereas a syn/anti mixture is obtained in a non-protic solvent. This is in sharp contrast to the carbocupration of the same ynone substrate with a cyanocuprate (RCu(CN)Li), which is highly selective for syn-addition. The product selectivities can be understood from a detailed computational characterization of the reaction paths, and in particular from the relative stabilities of the vinyl cuprate and allenolate intermediates. It is suggested that the stereodetermining step is protonation of vinyl cuprate intermediates.

  • 3. Aili, Daniel
    et al.
    Enander, Karin
    Rydberg, Johan
    Lundström, Ingemar
    Baltzer, Lars
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Liedberg, Bo
    Aggregation-Induced Folding of a de novo Designed Polypeptide Immobilized on Gold Nanoparticles2006In: J. Am. Chem. Soc., no 128, p. 2194-2195Article in journal (Refereed)
  • 4. Andre, Sabine
    et al.
    Pei, Zichao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Siebert, Hans-Christian
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Gabius, Hans-Joachim
    Glycosyldisulfides from Dynamic Combinatorial Libraries as O-Glycoside Mimetics for Plant and Endogenous Lectins: Their Reactivities in Solid-Phase and Cell Assays and Conformational Analysis by Molecular Dynamics Simulations2006In: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, Vol. 14, p. 6314-6326Article in journal (Refereed)
    Abstract [en]

    Dynamic combinatorial library design exploiting the thiol-disulfide exchange readily affords access to glycosyldisulfides. In order to reveal lectin-binding properties of this type of non-hydrolyzable sugar derivative, libraries originating from a mixture of common building blocks of natural glycans and thiocompounds were tested against three plant agglutinins with specificity to galactose, fucose or N-acetylgalactosamine, respectively, in a solid-phase assay. Extent of lectin binding to matrix-immobilized neoglycoprotein presenting the cognate sugar could be reduced, and evidence for dependence on type of carbohydrate was provided by dynamic deconvolution. Glycosyldisulfides also maintained activity in assays of increased physiological relevance, that is, using native tumor cells and also adding to the test panel an endogenous lectin (galectin-3) involved in tumor spread and cardiac dysfunction. N-Acetylgalactosamine was pinpointed as the most important building block of libraries for the human lectin and the digalactoside as most potent compound acting on the toxic mistletoe agglutinin which is closely related to the biohazard ricin. Because this glycosyldisulfide, which even surpasses lactose in inhibitory capacity, rivals thiodigalactoside as inhibitor, their degrees of intramolecular flexibility were comparatively analyzed by computational calculations. Molecular dynamics runs with explicit consideration of water molecules revealed a conspicuously high degree of potential for shape alterations by the disulfide's three-bond system at the interglycosidic linkage. The presented evidence defines glycosyldisulfides as biologically active ligands for lectins

  • 5.
    Baltzer, Lars
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Klinman, J.P.
    Hynes, J.T.
    Limbach, H-H.
    Acid base catalysis in designed polypeptides2006In: Handbook of Hydrogen Transfer, Wiley , 2006Chapter in book (Refereed)
  • 6.
    Barletta, Julien
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry.
    [11C]Carbon Monoxide in Rhodium-/Palladium-Mediated Carbonylation Reactions2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Methods for the 11C-labeling of carbonyl compounds applicable in the preparation of radiotracers for Positron Emission Tomography (PET) are described. To this end [11C]carbon monoxide at low concentration was used in transition metal- mediated reactions.

    Stille couplings were employed in the synthesis of [carbonyl-11C]ketones from methyl and aryl halides with [11C]carbon monoxide. The synthesized [carbonyl-11C]ketones were obtained from the corresponding organostannanes with analytical radiochemical yields up to 98%.

    A number of synthetic routes were designed using [11C]carbon monoxide and rhodium complexes. Nitrene intermediates were generated from azides and reacted via a rhodium-mediated carbonylation reaction as a general synthetic route to [carbonyl-11C]isocyanates, versatile precursors. [carbonyl-11C]Isocyanate reacted via nucleophilic attack of an amine to form N,N’-diphenyl[11C]urea in 82% analytical radiochemical yield, ethyl phenyl[11C]carbamate was synthesized by the same route, using ethanol as the nucleophile, in 70% radiochemical yield. [11C]Isocyanate was also able to react in a [2+3] cycloaddition with ethylene oxide to form 3-phenyl[carbonyl-11C]oxazolidin-2-one in over 80% analytical radiochemical yield. This method was applied to the synthesis of a potential efflux system tracer [11C]hydroxyurea in 38% isolated radiochemical yield and the derivative 1-hydroxy-3-phenyl[11C]urea in 35% isolated radiochemical yield. Carbene intermediates, generated from diazo compounds, were reacted with [11C]carbon monoxide in the rhodium-mediated synthesis of [carbonyl-11C]ketenes. [carbonyl-11C]Ketene intermediates were utilised in the synthesis of diethyl[carbonyl-11C]malonate, from ethyl diazoacetate and ethanol. The product was obtained with a 20% isolated radiochemical yield. Alkylation of diethyl[carbonyl-11C]malonate, with ethyliodide and tetrabutylammonium fluoride, was successfully accomplished and diethyl diethyl[carbonyl-11C]malonate was synthesized in 50% analytical radiochemical yield. Several (carbonyl-13C)compounds were also synthesized using the described methods as a way of characterizing the position of the label using 13C-NMR.

  • 7.
    Barman, Jharna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Acharya, Sandipta
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Zhou, Chuanzheng
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Chatterjee, Subhrangsu
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Engström, Åke
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Chattopadhyaya, Jyoti
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Non-identical electronic characters of the internucleotidic phosphates in RNA modulate the chemical reactivity of the phosphodiester bonds2006In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 4, no 5, p. 928-941Article in journal (Refereed)
    Abstract [en]

    We here show that the electronic properties and the chemical reactivities of the internucleotidic phosphates in the heptameric ssRNAs are dissimilar in a sequence-specific manner because of their non-identical microenvironments, in contrast with the corresponding isosequential ssDNAs. This has been evidenced by monitoring the delta H8(G) shifts upon pH-dependent ionization (pK(a1)) of the central 9-guaninyl (G) to the 9-guanylate ion (G(-)), and its electrostatic effect on each of the internucleotidic phosphate anions, as measured from the resultant delta P-31 shifts (pKa(2)) in the isosequential heptameric ssRNAs vis-`a-vis ssDNAs: [d/r( 5'-Cp(1)Ap(2)Q(1)p(3)Gp(4)Q(2)p(5)Ap(6)C-3'): Q(1) = Q(2) = A (5a/5b) or C (8a/8b), Q(1) = A, Q(2) = C (6a/6b), Q(1) = C, Q(2) = A (7a/7b)]. These oligos with single ionizable G in the centre are chosen because of the fact that the pseudoaromatic character of G can be easily modulated in a pH-dependent manner by its transformation to G(-) (the 2'-OH to 2-O- ionization effect is not detectable below pH 11.6 as evident from the N1-Me-G analog), thereby modulating/titrating the nature of the electrostatic interactions of G to G- with the phosphates, which therefore constitute simple models to interrogate how the variable pseudoaromatic characters of nucleobases under different sequence context (J. Am. Chem. Soc., 2004, 126, 8674-8681) can actually influence the reactivity of the internucleotide phosphates as a result of modulation of sequence context-specific electrostatic interactions. In order to better understand the impact of the electrostatic effect of the G to G- on the tunability of the electronic character of internucleotidic phosphates in the heptameric ssRNAs 5b, 6b, 7b and 8b, we have also performed their alkaline hydrolysis at pH 12.5 at 20 degrees C, and have identified the preferences of the cleavage sites at various phosphates, which are p(2), p(3) and p(4) (Fig. 3). The results of these alkaline hydrolysis studies have been compared with the hydrolysis of analogous N1-Me-G heptameric ssRNA sequences 5c, 7c and 8c under identical conditions in order to establish the role of the electrostatic effect of the 9-guanylate ion (and the 2'-OH to 2-O- ionization) on the internucleotidic phosphate. It turned out that the relative alkaline hydrolysis rate at those particular phosphates ( p2, p3 and p(4)) in the N1-Me-G heptamers was reduced from 16-78% compared to those in the native counterparts [Fig. 4, and ESI 2 (Fig. S11)]. Thus, these physico-chemical studies have shown that those p2, p3 and p4 phosphates in the native heptameric RNAs, which show pK(a2) as well as more deshielding ( owing to weaker P-31 screening) in the alkaline pH compared to those at the neutral pH, are more prone to the alkaline hydrolysis because of their relatively enhanced electrophilic character resulting from weaker P-31 screening. This screening effect originates as a result of the systematic charge repulsion effect between the electron cloud in the outermost orbitals of phosphorus and the central guanylate ion, leading to delocalization of the phosphorus pp charge into its d pi orbitals. It is thus likely that, just as in the non-enzymatic hydrolysis, the enzymatic hydrolysis of a specific phosphate in RNA by general base-catalyss in RNA-cleaving proteins (RNase A, RNA phosphodiesterase or nuclease) can potentially be electrostatically influenced by tuning the transient charge on the nucleobase in the steric proximity or as a result of specific sequence context owing to nearest-neighbor interactions.

  • 8.
    Bergman, Jan
    et al.
    Södertörn University, School of Life Sciences.
    Johnson, Ann-Louise
    A short synthesis of the carbazole alkaloid clausine E2006In: Organic preparations and procedures international, ISSN 0030-4948, E-ISSN 1945-5453, Vol. 38, no 6, p. 593-599Article in journal (Refereed)
  • 9.
    Berner, Simon
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Biela, Sarah
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Ledung, Greger
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Bäckvall, Jan-E.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Oscarsson, Sven
    Activity boost of a biomimetic oxidation catalyst by immobilization onto a gold surface2006In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 244, no 1, p. 86-91Article in journal (Refereed)
    Abstract [en]

    Thiol-functionalized cobalt porphyrins were used as a model system for investigating catalytic activity in homogeneous and heterogeneous oxidation catalysis. Self-assemble monolayers of thiol-functionalized cobalt porphyrins were prepared on a gold surface and served as heterogenous catalysts. These immoblilized molecules prevented the strong inactivation observed for their homogeneous congener. As a result, the turnover number per molecule in heterogeneous catalysis was at least 100 times higher than that of the corresponding homogeneous catalyst. It is atypical for a heterogenized catalyst to outperform its homogeneous congener. The properties of the molecular layers were characterized on the molecular level by means of X-ray photoelectorn spectroscopy (XPS) and scanning tunneling microscopy (STM). The results demonstrate that the performance of these biomimetic catalysts can be dramatically improved if the catalyst arangement can be controlled on the molecular level.

  • 10.
    Björk, Malin
    et al.
    Södertörn University, School of Life Sciences. Karolinska Institute.
    Grivas, Spiros
    Södertörn University, School of Life Sciences. Karolinska Institute.
    Synthesis of novel 2-aminoimidazo[4,5-b]pyridines, including the thieno analogue of the cooked-food mutagen IFP2006In: Journal of Heterocyclic Chemistry, ISSN 0022-152X, E-ISSN 1943-5193, Vol. 43, no 1, p. 101-109Article in journal (Refereed)
    Abstract [en]

    Eight new compounds, including three new ring systems obtained via the Friedlander condensation of ortho-aminothiophenecarbaldehydes 11, 21 and 24 with creatinine (8), are reported. The condensation afforded 1, which is the thieno analogue of the cooked-food mutagen IFP (2-amino-1,6-dimethylfuro[2,3-e]imidazo[4,5-b]pyridine), and the benzothieno[2,3-e]- and benzothieno[3,2-e]imidazo[4,5-b]pyridines 2 and 3. Attempts to condense 11 with isocreatinine (12) were unsuccessful. Desulfurization of 3 gave the known cooked-food carcinogen PhIP. The 2-nitro (4) and 2-hydroxy (5) derivatives of 3 are reported. The related 2-amino-1-methyl-imidazo[4,5-b]benzothiophene (25) was synthesized by a different route. Fully assigned H-1 and C-13 nmr data of all new compounds are reported.

  • 11.
    Bogár, Krisztián
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Olofsson, Berit
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Fransson, Ann-Britt L.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Bäckvall, Jan-E.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Asymmetric synthesis of 3,5-disubstituted piperidines by enzyme-metal combo catalysis2006In: Enzymatic Synthesis, Stockholm, Sweden, 2006Conference paper (Other (popular science, discussion, etc.))
  • 12.
    Bring, Torun
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Red Glass Coloration: a Colorimetric and Structural Study2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The aim of this thesis has been to find alternatives in the alkali silicate glass system to the most commonly used red glass pigment today, which is based on Cd(S, Se). The overall strategy has been to facilitate the use of already existing, well known but complicated and control-demanding pigments. Also the possi¬bilities to obtain red glass by combining elements as briefly reported in litera¬ture as possible red glass pigments, has been investigated.

    It has been found that by combining molybdenum and selenium in alkali-lime-silica glass under reducing conditions, a red pigment can be obtained. Red glass originating from this combination has not been reported earlier. The pigment is sensitive to batch composition and some glass components must be avoided. UV/vis spec¬troscopy and CIE colour coordinates were used when colour of samples was evaluated. Both ESCA and XANES give evidence that molybde¬num is present as Mo6+ ions. The colour is caused by an interaction between the molybdenum ions and selenium under reducing conditions. The presence of se¬lenium in a reduced state is evidenced by UV/vis spectroscopy and XANES analysis.

    The colour development in copper ruby glasses was studied by UV/vis spectros¬copy. It was observed that when low concentrations of colouring components were used, the pigment is stable regarding colour over long periods of time. Ex¬peri¬mental results from TEM and EXAFS provided good evidence that the col¬our origi¬nates from nanoparticles of metallic copper. This is in analogy with the gold ruby pigment.

    The impact of different reducing agents on the copper and gold ruby pigments was examined. It was concluded that SnO has a stronger reducing capacity to¬wards copper than Sb2O3 in alkali silicate glasses. The copper ruby colour can be obtained by the use of one of these reducing agents solely. Shifts in absorbance peak position as well as in colour hues are observed in both pigments and the largest shifts in absorption are observed in blue or bluish glasses, probably caused by larger particles.

    The possibility to combine red colour and semi-transparent alabaster glasses was studied. The studies however, indicated that the alabaster effect is not compati¬ble with pigments requiring strongly reducing conditions.

    Both gold and copper rubies are more environmentally friendly than the cad¬mium based Cd(S, Se) pigment, and must be regarded as possible alternatives. The Mo/Se pigment can also be an alternative.

  • 13.
    Bäck, Marcus
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, The Institute of Technology.
    Design and Synthesis of Hepatitis C Virus NS3 Protease Inhibitors Incorporating a P2 Cyclopentane-Derived Scaffold2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the design, synthesis and structure-activity relationships analysis of potential inhibitors targeting the hepatitis C virus (HCV) NS3 protease. Also discussed is the disease caused by HCV infection and the class of enzymes known as proteases. Furthermore are explained why such enzymes can be considered to be suitable targets for developing drugs to combat diseases in general and in particular HCV, focusing on the NS3 protease. Moreover, some strategies used to design protease inhibitors and the desired properties of potential drug candidates are briefly examined. Synthesis of linear and macrocyclic NS3 protease inhibitors comprising a designed trisubstituted cyclopentane moiety as an N-acyl-(4R)-hydroxyproline bioisostere is also addressed, and several very potent and promising compounds are evaluated.

  • 14.
    Chatterjee, Subhrangsu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Pathmasiri, Wimal
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Plashkevych, Oleksandr
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Honcharenko, Dmytro
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Varghese, Oommen P.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Maiti, Mohitosh
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Chattopadhyaya, Jyoti
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    The chemical nature of the 2'-substituent in the pentose-sugar dictates the pseudoaromatic character of the nucleobase (pKa) in DNA/RNA2006In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 4, no 9, p. 1675-1686Article in journal (Refereed)
  • 15. Cotton, Hanna K.
    et al.
    Norinder, Jakob
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Bäckvall, Jan-E.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Screening of Ligands in the Asymmetric Metallocenethiolatocopper(I)-Catalyzed Allylic Substitution with Grignard Reagents2006In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 62, no 24, p. 5632-5640Article in journal (Refereed)
    Abstract [en]

    Screening of metallocenethiolate ligands for copper(I)-catalyzed substitution of allylic acetates with Grignard reagents has been carried out. The previously used ligand, lithium (R,Sp)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4a), possessing both central and planar chirality, was the starting point for the screening. It was found that the diastereomeric ligand lithium (R,Rp)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4b) exhibiting reversed planar chirality gave increased enantioselectivity in the allylic substitution, at least when cinnamyl acetate was used as a substrate. The ruthenocene-based ligand lithium (R,Sp)-2-(1-dimethylaminoethyl)ruthenocenylthiolate (4c) gave an enhanced reaction rate, but lower chiral induction. The use of disulfide bis[(R,Sp)-2-(1-dimethylaminoethyl)ferrocenyl]disulfide (7a) as a ligand precursor worked well but resulted in lower enantioselectivity.

  • 16.
    Dinér, Peter
    et al.
    Department of Chemistry, University of Gothenburg.
    Amedjkouh, Mohamed
    Aminophosphonates as organocatalysts in the direct asymmetric aldol reaction towards syn selectivity in the presence of Lewis bases2006In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 4, no 11, p. 2091-2096Article in journal (Refereed)
  • 17.
    Dong, Hai
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Efficient carbohydrate synthesis by controlled inversion strategies2006Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In this study it has been demonstrated that a neighboring equatorial ester group plays a highly important role in this carbohydrate epimerization reaction, inducing the formation of inversion compounds in good yields. Based on this effect, efficient synthetic routes to a range of carbohydrate structures, notably β-D-mannosides and β-D-talosides, were designed. By use of the ester activation effect for neighboring groups, a double parallel as well as a double serial inversion strategy was developed.

  • 18.
    Dong, Hai
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Pei, Zhichao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Stereospecific Ester Activation in Nitrite-Mediated Carbohydrate Epimerization2006In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, no 8, p. 3306-3309Article in journal (Refereed)
    Abstract [en]

    The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In the present study, epimerization of gluco- and galactopyranoside derivatives to the corresponding allo- and gulopyranoside structures by triflation/nitrite treatment has been investigated. It was found that a neighboring ester group was essential for the reactivity of the nitrite-mediated triflate, inversion. Furthermore, a good inversion yield also depended on the relative configuration of the neighboring ester group to the triflate. Only with the ester group in the equatorial position, whatever the configuration of the triflate, did the reaction proceed smoothly, whereas a neighboring axial ester group proved largely inefficient. The results were subsequently used to predict the inversion of glucopyranoside derivatives to the mannopyranoside epimers.

  • 19.
    Engman, Lars
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    McNaughton, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Gajewska, Malgorzata
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Kumar, Sangit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Birmingham, Anne
    Powis, Garth
    Thioredoxin reductase and cancer cell growth inhibition by organogold(III) compounds2006In: Anti-Cancer Drugs, ISSN 0959-4973, E-ISSN 1473-5741, Vol. 17, no 5, p. 539-544Article in journal (Refereed)
    Abstract [en]

    Thioredoxin (Trx) expression is increased in several human primary cancers associated with aggressive tumor growth and decreased patient survival, and the Trx/Trx reductase (TrxR) system therefore provides an attractive target for cancer drug development. Various gold(III) compounds with none, one, two or three carbon-gold bonds were evaluated for their capacity to inhibit TrxR and the growth of MCF-7 cancer cells in vitro. Compounds with up to two carbon-gold bonds were often potent inhibitors of TrxR with IC50 values as low as 2 nmol/l. In the presence of Trx and insulin the inhibiting capacity was much lower. However, the inhibitory concentrations of the compounds did not correlate with the ability to kill cells. Out of the organometallics tested, only compound 8 with two carbon-gold bonds was able to inhibit colony formation by MCF-7 breast cancer cells at low micromolar concentrations (IC50=1,6umol/l). Unfortunately, the compound did not show any anti-tumor activity against MCF-7 breast cancer and HT-29 colon cancer zenografts in scid mice.

  • 20.
    Eriksson, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Isolation, Synthesis and Structure-Activity Relationships of Antifeedants against the Pine Weevil, Hylobius Abietis2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The large pine weevil, Hylobius abietis L., is a major insect pest on conifer seedlings in northern Europe. Due to its feeding newly planted trees get girdled, resulting in high seedling mortality (up to 80%). As a consequence great financial losses to the forest industry occur. Today the seedlings are protected with the pyrethroid insecticide cypermethrin. This insecticide is toxic to aquatic organisms and is, from 2010, prohibited for use in Sweden by the Swedish Chemicals Inspectorate. An alternative to insecticides is to protect the seedlings with antifeedants, compounds that, either through taste or smell or both, deter the weevils from feeding. This thesis describes the search for and the synthesis of such antifeedant compounds.

    Bark extracts of several woody species, known to be non-palatable to the weevil, were prepared and found to display antifeedant activity against H. abietis. The major chemical constituents of the extracts were tested for antifeedant activity. Antifeedants such as eugenol, 2-phenylethanol and benzylalcohol, but also feeding stimulants such as β-sitosterol and linoleic acid, were identified. An extract of linden bark, Tilia cordata, was shown to contain nonanoic acid, a highly active antifeedant. Other aliphatic carboxylic acids were also found to display high antifeedant activities against the weevil, both in laboratory and in field tests.

    The enantiomers of dihydropinidine, a piperidine alkaloid present in several conifer species, were prepared by dimethylzinc mediated allylation of 2- methyltetrahydropyridine-N-oxide. When tested in micro feeding assays, no difference in antifeedant activity was found for the enantiomers. In a field test high antifeedant activity, comparable with that of the presently used insecticide cypermethrin, was found for (±)-dihydropindine. Other naturally occurring piperidine alkaloids were synthesised and also found to display high antifeedant activities in laboratory tests.

    Structure-activity relationships were evaluated for methoxy substituted benzaldehydes, benzoic acids and cinnamic aldehydes, -acids, -esters and -alcohols. While the carboxylic acids were inactive or even feeding stimulants, the aldehydes were the most active antifeedants

  • 21. Eriksson, Carina
    et al.
    Sjödin, Kristina
    Schlyter, Fredrik
    Högberg, Hans-Erik
    Synthesis of (+)- and (−)-dihydropinidine by diastereoselective dimethylzinc promoted allylation of 2-methyltetrahydropyridine-N-oxide with an allylboronic ester2006In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 17, no 7, p. 1074-1080Article in journal (Refereed)
    Abstract [en]

    The enantiomers of the naturally occurring alkaloid dihydropinidine 1, potential antifeedants against the pine weevil, Hylobius abietis, were prepared by diastereoselective, dimethylzinc mediated addition of pinacolyl 2-propenylboronate 14 to nitrones (R)- and (S)2-methyl tetrahydropyridine-N-oxide 3, prepared from D- and L-alanine, respectively.

  • 22.
    Ersmark, Karolina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Nervall, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Gutiérrez-de-Terán, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Hamelink, Elizabeth
    Janka, Linda K.
    Clemente, Jose C.
    Dunn, Ben M.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Samuelsson, Bertil
    Åqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Hallberg, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Macrocyclic inhibitors of the malarial aspartic proteases plasmepsin I, II, and IV2006In: Biorganic & Medicinal Chemistry, no 14, p. 2197-2208Article in journal (Refereed)
  • 23. Fang, Yao-ren
    et al.
    MacMillar, Susanna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Kolodziejska-Huben, Magdalena
    Dybala-Defratyka, Agnieszka
    Paneth, Piotr
    Matsson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Westaway, Kenneth Charles
    The Effect of Solvent on the Structure of the Transition State for the SN2 Reaction between Cyanide Ion and Ethyl Chloride in DMSO and THF Probed with Six Different Kinetic Isotope Effects2006In: J. Org. Chem, no 71, p. 4742-4747Article in journal (Refereed)
    Abstract [en]

    The secondary a- and B-deuterium, the a-carbon, the nucleophile carbon, the nucleophile nitrogen, and the chlorine leaving group kinetic isotope effects forthe SN2 reaction between cyanide ion an dethyl chloride were determined in the very slightly polar solvent THF at 30 C. A comparison of these KIEs with those reported earlier for the same reaction in the polar solvent DMSO shows that the transition state in THF is only sligthly tighter with very slightly shorter NC-Ca-CI bonds. This minor change in transition state structure does not account for the different transition structures that were earlier suggested by interpreting the experimental KIEs and the gas-phase calculations, respectively. It therefore seems unlikely that the different transition states suggested by the two methods are due to the lack of appropriate solvent modeling in the theoretical calculations. Previously it was predicted that the transition state of SN2 reactions where the nucleophile and the leaving group have the same charge would be unaffected by a charge in solvent. The experimental KIEs support this view.

  • 24.
    Fransson, Ann-Britt L.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Deracemization of Functionalized Alcohols via Combined Ruthenium and Enzyme Catalysis2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed racemization or epimerization and lipase-catalyzed asymmetric transformations. A minor part of this thesis is focused on ruthenium-catalyzed redox reactions for transfer hydrogenation of 1,3-cycloalkanediketones.

    Kinetic resolution of racemic γ-hydroxy acid derivatives was performed via Pseudomonas cepacia lipase (PS-C)-catalyzed transesterification. γ-Hydroxy esters and γ-hydroxy amides were studied showing in higher selec-tivity and yields for the γ-hydroxy amides. The enzyme PS-C tolerates both variation in the chain length and different functionalities giving good to high enantioselectivity. Combining enzymatic kinetic resolution with a ruthenium-catalyzed racemization led to a dynamic kinetic resolution (DKR). The use of 2,4-dimethyl-3-pentanol as a hydrogen source to suppress ketone formation in the dynamic kinetic resolution increased the yields of the acetate product. The synthetic utility of this procedure was illustrated by the practical synthesis of the γ-lactone (R)-5-methyltetrahydrofuran-2-one.

    A distereoselective transformation of cis/trans-1,3-cyclohexandiol using Candida antarctica lipase B (CALB)-catalyzed transesterification was of interest. Desymmetrization of cis-1,3-cyclohexanediol to the (R-monoacetate was successfully accomplished. Enantiopure (R,R)-diacetate was obtained from the (R)-monoacetate in a DYKAT process at room tem-perature. Metal- and enzyme-catalyzed transformation of cis/trans-1,3-cyclohexanediol using PS-C, gives a high diastereoselectivity for cis-diacetate. The (S)-mono-acetate was obtained from cis-diacetate by CALB-catalyzed hydrolysis. In addition, it was shown, by the use of deuterium-labeling that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

    Ruthenium-catalyzed transfer hydrogenation of 1,3-cyclohexanedione under microwave heating was developed as an efficient and fast method for the preparation of 1,3-cycloalkandiols.

  • 25.
    Fransson, Ann-Britt L.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Xu, Yongmei
    Leijondahl, Karin
    Bäckvall, Jan-Erling
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Enzymatic Resolution, Desymmetrization and Dynamic Kinetic Asym-metric Transformation of 1,3-Cycloalkanediols2006In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, no 17, p. 6309-6316Article in journal (Refereed)
    Abstract [en]

    An efficient desymmetrization of cis-1,3-cyclohexanediol to (1S,3R)-3-(acetoxy)-1-cyclohexanol ((R,S)-2a) was performed via Candida antarctica lipase B (CALB)-catalyzed transesterification, in high yield (up to 93%) and excellent enantioselectivity (ee's up to >99.5%). (R,R)-Diacetate ((R,R)-3a) was obtained in a DYKAT process at room temperature from (1S,3R)-3-acetoxy-1-cyclohexanol ((R,S)-2a), in a high trans/cis ratio (91:9) and in excellent enantioselectivity of >99%. Metal- and enzyme-catalyzed dynamic transformation of cis/trans-1,3-cyclohexanediol using PS-C gave a high diastereoselectivity for cis-diacetate (cis/trans = 97:3). The (1R,3S)-3-acetoxy-1-cyclohexanol (ent-(R,S)-2a) was obtained from cis-diacetate by CALB-catalyzed hydrolysis in an excellent yield (97%) and selectivity (>99% ee). By deuterium labeling it was shown that intramolecular acyl migration does not occur in the transformation of cis-monoacetate to the cis-diacetate.

  • 26. Friberg, Annika
    et al.
    Johanson, Ted
    Franzén, Johan
    Division of Organic Chemistry, Center for Chemistry and Chemical Engineering, Lund University.
    Gorwa-Grauslund, Marie F.
    Frejd, Torbjoern
    Efficient bioreduction of bicyclo[2.2.2]octane-2,5-dione and bicyclo[2.2.2]oct-7-ene-2,5-dione by genetically engineered Saccharomyces cerevisiae2006In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 4, no 11, p. 2304-2312Article in journal (Refereed)
    Abstract [en]

    A screening of non-conventional yeast species and several Saccharomyces cerevisiae ( baker's yeast) strains overexpressing known carbonyl reductases revealed the S. cerevisiae reductase encoded by YMR226c as highly efficient for the reduction of the diketones 1 and 2 to their corresponding hydroxyketones 3 - 6 ( Scheme 1) in excellent enantiomeric excesses. Bioreduction of 1 using the genetically engineered yeast TMB4100, overexpressing YMR226c, resulted in > 99% ee for hydroxyketone (+)- 4 and 84 - 98% ee for (-)- 3, depending on the degree of conversion. Baker's yeast reduction of diketone 2 resulted in > 98% ee for the hydroxyketones (+)- 5 and (+)- 6. However, TMB4100 led to significantly higher conversion rates ( over 40 fold faster) and also a minor improvement of the enantiomeric excesses (> 99%).

  • 27.
    Frölander, Anders
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Lutsenko, Serghey
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Privalov, Timofei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Moberg, Christina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    OH-Metal hydrogen bond in Pd- and Ir-catalyzed allylic alkylations2006In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 2006, p. ORGN-259-Conference paper (Other academic)
    Abstract [en]

    Phosphinooxazolines carrying 4-hydroxybenzyl and 4-methoxybenzyl substituents exhibit contrasting behavior in Pd- and Ir-catalyzed allylic alkylations.  Whereas catalysts with the methoxy-contg. ligand generally provide products with high ee's, use of catalysts prepd. from the hydroxy contg. ligand results in products with low ee's or even racemates.  DFT calcns. suggest the presence of a hydrogen bond with Pd(0) as proton acceptor in the hydroxy contg. olefin Pd(0) complexes, which induces a conformational change in the ligand leading to different stereoselectivity.  We have previously obsd. the same kind of dramatic changes of enantioselectivities in palladium-catalyzed allylations upon methylation of hydroxy-contg. pyridinooxazolines and bisoxazolines.

  • 28.
    Govender, Thavendran
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Hojabri, Leila
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Matloubi Moghaddam, Firouz
    Arvidsson, Per I.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Organocatalytic synthesis of chiral benzopyrans2006In: Tetrahedron: Asymmetry, no 17, p. 1763-1767Article in journal (Refereed)
    Abstract [en]

    Benzopyrans, or chromenes, are widespread in nature and are considered to be a privileged scaffold in medicinal chemistry. Herein, we report the first organocatalyzed asymmetric synthesis of chiral benzopyrans. The benzopyran unit is constructed through a domino reaction involving an oxa-Michael attack of salicylic aldehyde derivatives onto a,B-unsaturated aldehydes, activated through iminium-ion formation with the organocatalyst, followed by an intramolecular aldol reaction and subsequent elimination of water. This overall reaction sequence provides benzopyrans with aromatic C-2 substituents in up to 60% enantioselectivity, while C-2 aliphatic analogues can be obtained in 90% enantiomeric excess, but with only 20% yield. The role of additives, as well as the possible racemization of the benzopyran, was also investigated.

  • 29.
    Hamberg, Anders
    et al.
    KTH, School of Biotechnology (BIO), Biochemistry.
    Lundgren, Stina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Penhoat, Maël
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Moberg, Christina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Hult, Karl
    KTH, School of Biotechnology (BIO), Biochemistry.
    High-Throughput Enzymatic Method for Enantiomeric Excess Determination of O-Acetylated Cyanohydrins2006In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 7, p. 2234-2235Article in journal (Refereed)
  • 30. Hansen, Anders L.
    et al.
    Ebran, Jean-Philippe
    Ahlquist, Mårten
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Norrby, Per-Ola
    Skrydstrup, Troels
    Heck coupling with nonactivated alkenyl tosylates and phosphates: Examples of effective 1,2-migrations of the alkenyl palladium(II) intermediates2006In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 45, no 20, p. 3349-3353Article in journal (Refereed)
  • 31.
    Holm, Lotta
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The MHC-glycopeptide-T cell interaction in collagen induced arthritis: a study using glycopeptides, isosteres and statistical molecular design in a mouse model for rheumatoid arthritis2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rheumatoid arthritis (RA) is an autoimmune disease affecting approximately 1% of the population in the western world. It is characterised by a tissue specific attack of cartilage in peripheral joints. Collagen induced arthritis (CIA) is one of the most commonly used animal models for (RA), with similar symptoms and histopathology. CIA is induced by immunisation of mice with type II collagen (CII), and the immunodominant part was previously found to be located between residues 256-270. This thesis describes the interaction between the MHC molecule, glycopeptide antigens from CII and the T cells that is essential in development of CIA. The glycopeptide properties for binding to the mouse MHC molecule Aq have been studied, as well as interaction points in the glycopeptide that are critical for stimulation of a T-cell response.

    The thesis is based on five studies. In the first paper the minimal glycopeptide core, that is required for binding to the Aq molecule while still giving a full T cell response was determined. The second paper studied the roles of amino acid side-chains and a backbone amide bond as T-cell contact points. In the third paper the hydrogen bond donor-acceptor characteristics of the 4-OH galactose hydroxyl group of the glycopeptide was studied in detail. In the fourth paper we established a structure activity relationship (QSAR model) for (glyco)peptide binding to the Aq molecule. Finally, the stereochemical requirements for glycopeptide binding to the Aq molecule and for T-cell recognition was studied in the fifth paper.

    The study was performed using collagen glycopeptide analogues, which were synthesised on solid phase. Amide bond and hydroxyl group isosteres were introduced for study of hydrogen bond donor-acceptor characteristics. Statistical methods were used to design a representative peptide test set and in establishing a QSAR model.

    The results give a deeper understanding of the interactions involved in the ternary MHC-glycopeptide-T cell complex. This information contributes to research directed towards finding new treatments for RA.

  • 32.
    Honcharenko, D.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Bioorganic Chemistry.
    Varghese, O.P.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Bioorganic Chemistry.
    Plashkevych, O.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Bioorganic Chemistry.
    Barman, J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Bioorganic Chemistry.
    Chattopadhyaya, Jyoti
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Bioorganic Chemistry.
    Synthesis and Structure of Novel Conformationally-constrained 1'2'-Azetidine-Fused Bicyclic Pyrimidine Nucleosides: Their Incorporation into Oligo-DNAs and the Thermal Stability of the Heteroduplexes2006In: Journal of Organic Chemistry, Vol. 71, p. 299-314Article in journal (Refereed)
  • 33.
    Honcharenko, Dmytro
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Varghese, Oommen P.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Plashkevych, Oleksandr
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Barman, Jharna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Chattopadhyaya, Jyoti
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Synthesis and Structure of Novel Conformationally Constrained 1‘,2‘-Azetidine-Fused Bicyclic Pyrimidine Nucleosides: Their Incorporation into Oligo-DNAs and Thermal Stability of the Heteroduplexes2006In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 71, no 1, p. 299-314Article in journal (Refereed)
  • 34.
    Isaksson, Dan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Lipase catalysed reactions of terpenoids : formation of hemiacetal esters : resolution of cryptone and its transformation to cadinenes2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    During attempted enzyme-catalysed resolution of sterically hindered secondary alcohols, hemiacetals and their esters were unexpectedly detected. Hemiacetal esters are reactive compounds that decompose to alcohol, aldehyde and acid under ordinary work-up conditions i.e. in contact with water, acid, or silica gel. Thus, the presence of these side products might decrease the enantiomeric excess of the residual alcohol after workup of a lipase-catalysed resolution. The formation of these hemiacetal esters were further studied using both terpenoid and non-terpenoid substrate alcohols, various acyl donors, and lipases. The prerequisite for their formation is the presence of a sterically hindered substrate alcohol, an aldehyde or an aldehyde releasing acyl donor, and a lipase (PCL-L6, PCL-PS and CAL-B).

    Enantioselective synthesis of (S)- and (R)-cryptone was performed via a ring closing metathesis (RCM) of (S)- and (R)-6-isopropyl-1,7-octadien-3-one. The stereochemistry was induced by using pseudoephedrine as chiral auxiliary in an alkylation reaction which provided a chiral octadienone. Problems with removal of the RCM-catalyst resulted in low yields and low enantiomeric purity. In an alternative approach, racemic cryptone was subjected to conjugate addition with thiophenol followed by reduction to the corresponding alcohol. Lipase-catalysed resolution of this alcohol yielded, after oxidation and elimination, (R)- and (S)- cryptone with 76% and 98% ee, respectively.

    Marine fouling of immersed objects is a serious problem. Many coatings contain effective antifouling compounds having the drawback of being toxic to the marine environment. The marine natural product 10-isocyano-4-cadinene is a potentially non-toxic antifouling agent against the barnacle Balanus amphitrite and therefore an interesting target for organic synthesis. Cryptone was used as a starting material in attempted syntheses of this compound and other similar model compounds.

  • 35. Isaksson, Dan
    et al.
    Sjödin, Kristina
    Högberg, Hans-Erik
    Enantiomerically enriched cryptone by lipase catalysed kinetic resolution2006In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 17, no 2, p. 275-280Article in journal (Refereed)
    Abstract [en]

    Thiophenol was added to racemic cryptone (4-isopropyl-2-cyclohexene-1-one) and the resulting 1,4-addition products, cis- and trans-4-isopropyl-3- (phenylsulfanyl)cyclohexanone were separated and the latter reduced to rac-1,3-cis-1,4-trans-4-isopropyl-3-(phenylsulfanyl)cyclohexanol, which was subjected to lipase catalysed resolution by acylation catalysed by CAL-B (Candida antarctica lipase B). The alcohol enantiomers obtained were oxidised. The remaining alcohol was separated from the produced acetate, which was hydrolysed to the alcohol. The initial products, probably sulfoxidoketones spontaneously decomposed to furnish enantiomerically enriched (R)- and (S)-cryptone with up to 76% and 98% ee, respectively

  • 36.
    Itsenko, Oleksiy
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Kihlberg, Tor
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Labeling of aliphatic carboxylic acids using [11C]carbon monoxide2006In: Nature Protocols, ISSN 1754-2189, Vol. 1, no 2, p. 798-802Article in journal (Refereed)
    Abstract [en]

    Here we present a protocol for labeling aliphatic carboxylic acids with the positron-emitting radionuclide 11C (t1/2 = 20.4 min) at the carboxyl position using [11C]carbon monoxide via photoinitiated free radical-mediated carbonylation. A solution of an alkyl iodide in a homogenous binary organic solvent-water mixture is introduced into a high-pressure photochemical reactor containing [11C]carbon monoxide. Then the reactor contents are pressurized to 40 MPa and irradiated with ultraviolet light for 6 min. The labeled product is purified using HPLC. All manipulations with radioactivity including the labeling synthesis are carried out on an automated Synthia system. In a typical case, 3.19 GBq of purified [1-11C]1,10-decanedicarboxylic acid (with a specific radioactivity of 188 GBq/μmol) can be obtained within 35 min after the end of a 10-μAh bombardment. Compared to previous labeling methods, this protocol is compatible with a wider range of functional groups, utilizes less-sensitive precursors, and is less subject to isotopic dilution.

  • 37. Janosik, Tomasz
    et al.
    Shirani, Hamid
    Wahlström, Niklas
    Malky, Ilham
    Stensland, Birgitta
    Bergman, Jan
    Södertörn University, School of Life Sciences. Karolinska Institute.
    Efficient sulfonation of 1-phenylsulfonyl-1H-pyrroles and 1-phenylsulfonyl-1H-indoles using chlorosulfonic acid in acetonitrile2006In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 62, no 8, p. 1699-1707Article in journal (Refereed)
    Abstract [en]

    The sulfonation of various 1-phenylsulfonyl-1H-pyrroles and 1-phenylsulfonyl-1H-indoles using chlorosulfonic acid in acetonitrile has been studied, leading to the development of a clean and operationally simple protocol allowing direct synthesis of the corresponding 1-phenylsulfonyl-1H-pyrrole-3-sulfonyl chlorides and 1-phenylsulfonyl-1H-indole-3-sulfonyl chlorides, respectively, both of which may be easily converted to various sulfonamide derivatives by treatment with nitrogen nucleophiles. Efficient and selective removal of the phenylsulfonyl- or tosyl groups in the sulfonamide series may be achieved under mild conditions.

  • 38. Johnson, A. -L
    et al.
    Slätt, J.
    Janosik, T.
    Bergman, Jan
    Södertörn University, School of Life Sciences. Karolinska Institute.
    Stereoselective synthesis and isomerization of the indole alkaloid murrayacarine2006In: Heterocycles, ISSN 0385-5414, E-ISSN 1881-0942, Vol. 68, no 10, p. 2165-2170Article in journal (Refereed)
    Abstract [en]

    A short and efficient stereoselective synthesis of the indole alkaloid murrayacarine is described, including studies on its acid-induced isomerization.

  • 39. Johnson, Ann-Louise
    et al.
    Bergman, Jan
    Södertörn University, School of Life Sciences. Karolinska Institute.
    Synthetic approaches towards an indole alkaloid isolated from the marine sponge Halichondria melanodocia2006In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 62, no 47, p. 10815-10820Article in journal (Refereed)
    Abstract [en]

    The exocyclic analogue of the indole alkaloid isolated from the marine sponge Halichondria melanodocia has been prepared via olefination of a phosphonoester derived from 3-(2-bromoacyl)indole. The formation of an unexpected indolylazepine is also discussed.

  • 40.
    Johnson, Ann-Louise
    et al.
    Unit for Organic Chemistry, Department of Biosciences, Karolinska Institute and Södertörn University College, Novum Research Park,.
    Slätt, Johnny
    Unit for Organic Chemistry, Department of Biosciences, Karolinska Institute and Södertörn University College, Novum Research Park,.
    Janosik, Tomasz
    Unit for Organic Chemistry, Department of Biosciences, Karolinska Institute and Södertörn University College, Novum Research Park,.
    Bergman, Jan
    Unit for Organic Chemistry, Department of Biosciences, Karolinska Institute and Södertörn University College, Novum Research Park,.
    Stereoselective synthesis and isomerization of the indole alkaloid murrayacarine2006In: Heterocycles, ISSN 0385-5414, E-ISSN 1881-0942, Vol. 68, no 10, p. 2165-2170Article in journal (Refereed)
    Abstract [en]

    A short and efficient stereoselective synthesis of the indole alkaloid murrayacarine is described, including studies on its acid-induced isomerization.

  • 41.
    Jonsson, K. Hanna M.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Weintraub, Andrej
    Widmalm, Göran
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Structural studies of the O-antigenic polysaccharide from Shigella dysenteriae type 3 and Escherichia coli O124, a reinvestigation2006In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 341, p. 2986-2989Article in journal (Refereed)
  • 42.
    Kauppi, Anna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Chemical attenuation of bacterial virulence: small molecule inhibitors of type III secretion2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Despite the large arsenal of antibiotics available on the market, treatment of bacterial infections becomes more challenging in view of the fact that microbes develop resistance against existing drugs. There is an obvious need for novel drugs acting on both old and new targets in bacteria. In this thesis we have employed a whole cell bacterial assay for screening and identification of type III secretion system (T3SS) inhibitors in Yersinia pseudotuberculosis. The T3SS is a common virulence mechanism utilized by several clinically relevant Gram-negative bacteria including Salmonella, Shigella, Pseudomonas aeruginosa, Chlamydiae and Escherichia coli. Several components in the T3SS have proved to be conserved and hence data generated with Y. pseudotuberculosis as model might also be valid for other bacterial species.

    We have screened a 9,400 commercial compound library for T3S inhibitors in Y. pseudotuberculosis using a yopE reporter gene assay. The initial ~ 30 hits were followed up in a growth inhibition assay resulting in 26 interesting compounds that were examined in more detail. Three of the most interesting compounds, salicylanilides, 2-hydroxybenzylidene-hydrazides and 2-arylsulfonamino-benzanilides, were selected for continued investigations. The inhibitor classes show different profiles regarding the effects on T3SS in Yersinia and their use as research tools and identification of the target proteins using a chemical biology approach will increase our understanding of bacterial virulence.

    The 2-hydroxybenzylidene-hydrazides have been extensively studied in vitro and show potential as selective T3S inhibitors in several Gram-negative pathogens besides Y. pseudotuberculosis. The data obtained suggest that this inhibitor class targets a conserved protein in the secretion apparatus. In cell-based ex vivo infection models T3SS was inhibited to the advantage of the infected eukaryotic cells. The salicylanilides and 2-arylsulfonamino-benzanilides have been further investigated by statistical molecular design (SMD) followed by synthesis and biological evaluation in the T3SS linked reporter gene assay. Multivariate QSAR models were established despite the challenges with data obtained from assays using viable bacteria. Our results indicate that this SMD QSAR strategy is powerful in development of virulence inhibitors targeting the T3SS.

  • 43.
    Källström, Klas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Asymmetric hydrogenation of tri-substituted alkenes with Ir-NHC-thiazole complexes2006In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 47, no 42, p. 7477-7480Article in journal (Refereed)
    Abstract [en]

    An efficient chiral N-heterocyclic carbene ligand for the Ir-catalyzed asymmetric hydrogenation of largely unfunctionalized tri-substituted olefins has been developed. The Ir-NHC-thiazole catalyst is able to reduce a large variety of substrates with excellent conversions and good enantioselectivities with ee's ranging from 34% to 90%, depending on the geometry around the double bond of the substrates.

  • 44.
    Källström, Klas
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Munslow, Ian
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Ir-Catalysed Asymmetric Hydrogenation: Ligands, Substrates and Mechanism2006In: Chem. Eur. J., no 12, p. 3194-3200Article in journal (Refereed)
  • 45.
    Källström, Klas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Munslow, Ian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Hedberg, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Iridium-Catalysed Asymmetric Hydrogenation of Vinylsilanes as a Route to Optically Active Silanes2006In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 348, no 18, p. 2575-2578Article in journal (Refereed)
    Abstract [en]

    The first use of vinylsilanes as substrates in the asymmetric iridium-catalysed hydrogenation is reported, providing products with enantioselectivities of up to 98%.

  • 46.
    Langlet, Abraham
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Nitration of Oxo-pyramidines and Oxo-imidazoles2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This thesis is mainly focused on the reactions of oxo-pyrimidines and oxo-imidazoles with nitric acid in sulfuric acid and properties of the gem-dinitro products formed in this process.

    Low temperature nitrations of 2-methylimidazoles produced – in addition to the known 2-methyl-5(4)-nitroimidazole – 2-(dinitromethylene)-5,5-dinitro-4-imidazolidinone and parabanic acid. This tetranitro compound was also obtained via nitration of 2-methyl-4,4-dihydro-(1H)-5- imidazolone. Thermal decomposition of 2-(dinitromethylene)-5,5-dinitro-4-imidazolidinone yielded 2-(dinitromethylene)-4,5-imidazolidinedione, which also was the product from the nitration of the new compound 2-methoxy-2-methyl-4,5-imidazolidienedione. Treatment of 2- (dinitromethylene)-5,5-dinitro-4-imidazolidinone with aqueous ammonia resulted in the previously unknown 1,1-diamino-2,2-dinitroethylene (Paper I).

    The nitration of some 2-substituted pyrimidine-4,6-diones in sulfuric acid, which afforded previously unknown 5,5-gem-dinitro-pyrimidine-4,6-diones in high yields, was studied. Alloxane was prepared in a one-step procedure by thermal decomposition of 5,5-dinitrobarbituric acid in hot acetic acid. The gem-dinitro products were found to be easily attacked by nucleophiles with concomitant formation of gem-dinitroacetyl derivatives, which in turn could be further hydrolysed to salts of dinitromethane and triureas (Papers II and III).

    Nitration of 4,6-dihydroxypyrimidine in sulfuric acid yielded nitroform as the sole product. This behaviour was tentatively explained by the formation of an intermediate, 5,5-dinitro-4,6- dihydroxypyrimidine, which underwent hydrolysis in the nitrating acid into gem-dinitroacetyl formamidine. This compound was further nitrated in the same reaction mixture into trinitroacetylformamidine, which finally underwent hydrolytic cleavage into nitroform. It was also demonstrated that gem-dinitroacetylureas could produce nitroform upon nitration. The structures of the proposed trinitroacetylureas were confirmed by the isolation of one of their derivatives (Paper IV).

  • 47.
    Larsson, Rikard
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Reversible Sulfur Reactions in Pre-Equilibrated and Catalytic Self-Screening Dynamic Combinatorial Chemistry Protocols2006Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Dynamic Combinatorial Chemistry (DCC) is a recently introduced supramolecular approach to generate dynamically interchanging libraries of compounds. These libraries are made of different building blocks that reversibly interact with one another and spontaneously assemble to encompass all possible combinations. If a target molecule, for instance a receptor is added to the system and one or more molecules show affinity to the target species, these compounds will, according to Le Châtelier´s principle, be amplified on the expense of the other non-bonding constituents. To date, only a handful of different systems and formats have been used. Hence, to further advance the technique, especially when biological systems are targeted, new reaction types and new screening methods are necessary. This thesis describes the development of reversible sulfur reactions, thiol/disulfide interchange and transthiolesterification (the latter being a new reaction type for DCC), as means of generating reversible covalent bond reactions. Two different types of target proteins are used, enzymes belonging to the hydrolase family and the plant lectin Concanavalin A. Furthermore, two new screening/analysis methods not previously used in DCC are also presented; the quartz crystal microbalance (QCM)-technique and catalytic self-screening.

  • 48.
    Larsson, Rikard
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Dynamic Combinatorial Thiolester Libraries for Efficient Catalytic Self-Screening of Hydrolase Substrates2006In: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, no 1, p. 285-291Article in journal (Refereed)
    Abstract [en]

    Dynamic combinatorial thiolester libraries were efficiently generated from pools of thiols and acyl functionalities through reversible transthiolesterification in aqueous media at neutral pH. The dynamic features of the library generation were investigated, and the libraries were screened against acetylcholinesterase, clearly demonstrating the catalytic self-screening of its substrates from the constituents. Acetyl- and propionylthiocholine were easily identified as the best substrates for the enzyme, whereas other constituents showed lower efficiency or were inactive. A range of hydrolases was furthermore screened for rapid substrate identification, clearly demonstrating the differences in selectivity. The results show that transthiolesterification is a useful method to generate dynamic libraries, and that the catalytic self -screening concept is highly valuable for substrate identification.

  • 49.
    Li, Junxin
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Grennberg, Helena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Microwave-Assisted Covalent Sidewall Functionalization of Multiwalled Carbon Nanotubes2006In: Chem. Eur. J., no 12, p. 3869-3875Article in journal (Refereed)
  • 50.
    Lindquist, Charlotta
    et al.
    Organisk kemi, Avdelningen för kemi, KTH.
    Ersoy, Oguz
    Somfai, Peter
    Parallel synthesis of an indole-based library via an iterativeMannich reaction sequence2006In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 62, no 14, p. 3439-3445Article in journal (Refereed)
    Abstract [en]

    A library of 1,3-disubstituted indoles has been prepared via an iterative Mannich reaction sequence. The first Mannich reaction with secondary amines and formaldehyde preferentially yields 3-aminomethyl indoles, while the second Mannich reaction introduces an additional aminomethyl group at the N1-position of the indole ring. A library of 25 substituted indoles has thus been prepared in moderate to good yields with purity.

123 1 - 50 of 102
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