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  • 1.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Karlsson, Jesper G.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svenson, Johan
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Can template-template self-association contribute to polymer-ligand recognition characteristics?2000Conference paper (Refereed)
  • 2.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    The development of molecular imprinting2000Other (Other academic)
  • 3. Belda, O
    et al.
    Kaiser, N F
    Bremberg, U
    Larhed, M
    Hallberg, A
    Moberg, C
    Highly stereo- and regioselective allylations catalyzed by Mo-pyridylamide complexes: Electronic and steric effects of the ligand2000In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 65, no 18, p. 5868-5870Article in journal (Refereed)
  • 4.
    Bergman, Jan
    et al.
    Södertörn University, Avdelning Naturvetenskap.
    Janosik, T
    Koch, E
    Pelcman, B
    Acid-induced dimerization of 3-(1H-indol-3-yl)maleimides. Formation of cyclopentindole derivatives2000In: JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, ISSN 1470-4358, no 16, p. 2615-2621Article in journal (Refereed)
    Abstract [en]

    Acid-induced dimerizations of 3-substituted maleimides have been investigated, leading to e.g. the cyclopentindole 9 and the deeply coloured spiro compounds 24 and 25 in good yields. 3-(1H-Indol-3-yl)maleimide 6b readily gave the cycloaddition products 13-15 on treatment with appropriate dienophiles. In addition, several related 3,3-di-(1H-indol-3-yl)succinimides have been prepared and studied.

  • 5.
    Bergman, Jan
    et al.
    Södertörn University, Avdelning Naturvetenskap.
    Janosik, T
    Yudina, L
    Desarbre, E
    Lidgren, G
    Venemalm, L
    Reactions of 1,2-bis(1H-indol-2-yl)ethane: Formation of indolo[2,3-c]carbazole and cyclohept[1,2-b : 5,4-b ']bisindole derivatives2000In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 56, no 13, p. 1911-1916Article in journal (Refereed)
    Abstract [en]

    1,2-Bis(1H-indol-2-yl)ethane (9) has been prepared and converted into indolo[2,3-c]carbazole (8) using palladium acetate in refluxing acetic acid. Reaction of 9 with CoF3 in hot TFA led to isolation of cyclohept[1,2-b:5,4-b']bisindole derivatives 11 and 12, which could be elaborated into further derivatives. Treatment of 9 with orthoesters, aldehydes and ketones under acidic conditions afforded additional bisindoles containing a seven-membered ring.

  • 6.
    Bergman, Jan
    et al.
    Södertörn University, Avdelning Naturvetenskap.
    Koch, E
    Pelcman, B
    Coupling reactions of indole-3-acetic acid derivatives. Synthesis of arcyriaflavin A2000In: JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, ISSN 1470-4358, no 16, p. 2609-2614Article in journal (Refereed)
    Abstract [en]

    The bisindolesuccinic acid methyl ester 10 was obtained by an iodine-promoted coupling of the dianion 9. The diester was converted to the N-benzylimide 12, which was oxidatively cyclized to the indolo[2,3-a]pyrrolo[3,4-c]carbazole 15. The diester 10 could be directly transformed to the known indolocarbazole diester 27 via acid-induced intramolecular cyclization in TFA. The same methodology gave arcyriaflavin A 4 from the succinimide 18b.

  • 7.
    Bowden, Tim
    Stockholm University.
    Studies on glycosylation mechanisms and synthesis of structures related to inositolphosphoglycans2000Doctoral thesis, comprehensive summary (Other academic)
  • 8. Brandt, Peter
    et al.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Exploring the Chemistry of 3-Substituted 2-Azanorbornyls in Asymmetric Catalysis2000In: Synlett, no 8, p. 1092-1106Article in journal (Refereed)
    Abstract
  • 9.
    Brandt, Peter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Södergren, Mikael
    Andersson, Pher
    Department of Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Norrby, Per-Ola
    Mechanistic Studies of Copper-Catalyzed Alkene Aziridination2000In: J. Am. Chem. Soc., ISSN 0002-7863, no 122, p. 8013-8020Article in journal (Refereed)
  • 10. Bremberg, U
    et al.
    Lutsenko, S
    Kaiser, N F
    Larhed, M
    Hallberg, A
    Mobert, C
    Rapid and stereoselective C-C, C-O, C-N and C-S couplings via microwave accelerated palladium-catalyzed allylic substitutions2000In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, no 7, p. 1004-1008Article in journal (Refereed)
    Abstract [en]

    Palladium-catalyzed substitution of cyclohex-2-en-1-yl ethyl carbonate with neutral C-, O-, and N-nucleophiles was achieved in 1-2 minutes using microwave flash hearing. Enantioselectivities up to 96% were observed. Ionic nucleophiles tended to result in lower ee. With S-nucleophiles problems with the stability of the nucleophile were encountered.

  • 11.
    Grivas, Spiros
    Södertörn University, Avdelning Naturvetenskap.
    2,1,3-benzoselenadiazoles as valuable synthetic intermediates2000In: Current organic chemistry, ISSN 1385-2728, E-ISSN 1875-5348, Vol. 4, no 7, p. 707-726Article in journal (Refereed)
    Abstract [en]

    N-alkyl-1,2-benzenediamines, 4-substituted-3-nitro-1,2-benzenediamines and 3,4-diamino-2-nitrophenols are readily obtained by deselenation of alkyl quaternary salts of 2,1,3-benzoselenadiazoles (bsd) and 5-substituted-4-nitro-bsd. The latter are easily obtained by nitration of 5-X-bsd (X = Me, Br, Cl, F, OMe, NHMe). Nitration of 5-fluoro-bsd yields the 4-nitro derivatives that are accompanied by substantial amounts of the corresponding 4-nitro-bsd-5-ols. ipso-Nitration of 5-fluoro-4-methyl-bsd is followed by instantaneous hydrolysis to (+/-)-4-methyl-4-nitro-bsd-5(4H)-one. Batcho-Leimgruber indole synthesis on 5-methyl-4-nitro-bsd followed by reductive deselenation of 1,2,5-selenadiazolo[3,4-g]indole affords 6,7-diaminoindole. Cyclocondensation of 3-nitro-1,2-benzenediamines with acetylacetone provides a convenient route for the preparation of 2-methyl-4-nitrobenzimidazoles. Less-accessible 6-halo-5-nitro- and 6-methoxy-5-nitroquinoxalines are efficiently synthesized by regioselective condensation of alpha-dicarbonyls with 4-halo- and 4-methoxy-3-nitro-1,2-benzenediamines. The reactive halogen atom or methoxyl group ortho to the nitro substituent renders these quinoxalines versatile intermediates to further heterocycles. The Se-77, C-13 and H-1 NMR chemical shifts of sixteen bsd derivatives, and the C-13 NMR chemical shifts of eight derivatives of 2-methylquinoxalines are presented.

  • 12.
    Hansson, Jonas
    Stockholm University.
    Synthesis of phosphate-containing oligosaccharides corresponding to capsular antigen structures from Haemophilus influenzae2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the synthesis of spacer-equipped di- and trimeric oligosaccharide structures corresponding to fragments of the capsular polysaccharides of Haemophilus influenzae types c and f. Both of these polysaccharides are of the teichoic acid type, built up by disaccharide repeating units linked via interglycosidic phosphodiester bonds. Introduction of the phosphodiester linkages was accomplished employing the glycosyl H-phosphonate method. The syntheses are designed in such a way as to allow the formation of even larger structures, as well as conjugation to a carrier protein. The first section of this thesis presents a general overview of the biological significance and structural features of anomeric phosphodiesters and synthetic approaches towards these structures, including a literature survey of research in this area during the past decade. In the second part, a new approach to the synthesis of anomeric phosphodiester linkages, utilizing non-anomeric glycosyl H-phosphonate acceptors and various galactosyl donors in glycosylation reactions, is described. Finally, synthesis of the capsular polysaccharide fragments of H. influenzae types c and f is discussed.

  • 13. Högberg, Hans-Erik
    et al.
    Lindmark, Marica
    KTH, Superseded Departments, Chemistry.
    Isaksson, Dan
    KTH, Superseded Departments, Chemistry.
    Sjödin, Kristina
    Franssen, Maurice
    Jongejan, Hugo
    Wijnberg, Joannes
    de Groot, Aeede
    Formation of hemiacetal esters in lipase-catalysed reactions of vinyl esters with secondary alcohols2000In: Tetrahedron Letters, Vol. 41, p. 3193-3196Article in journal (Refereed)
    Abstract [en]

    Normally many lipases are efficient catalysts for the acetylation of alcohols with vinyl acetate. Unexpectedly, we found that some sterically hindered secondary alcohols react slowly to yield hemiacetal esters as mixtures of diastereomers. Their formation can be explained by the reaction of the alcohol with acetaldehyde that is produced by the lipase-catalysed splitting of vinyl acetate and subsequent acetylation of the resulting hemiacetal by the lipase.

  • 14.
    Höög, Christer
    Stockholm University.
    Three-dimensional structure of oligosaccharides from molecular dynamics simulations2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis focuses on the conformation and flexibility of oligosaccharides around the glycosidic linkage. The methods employed for the elucidation of the three-dimensional structures of biomolecules are briefly described. The main techniques used here are computer simulations and molecular dynamics simulations in aqueous solution in particular. The experimental data derived from these simulations have been compared with nuclear magnetic resonance measurements. The results obtained demonstrate the occurrence of more than one conformation, even though at the same time the high value of the generalised order parameter indicates rigidity. Of special interest are the folded conformers discovered at the same linkage in a vicinally substituted trisaccharide dissolved in water. Such, folded conformers have been detected in carbohydrates earlier, but never at the same linkage.

    The free energy simulation methods thermodynamic perturbation and thermodynamic integration are described briefly and have been used to calculate the anomeric ratio of the monosaccharides D-xylose in water and methyl D-xyloside in methanol. Solvent effect of the a/b ratios were found to be small. The solvent structures surrounding these four monosaccharides were investigated utilising radial and spatial distribution functions.

  • 15.
    Johansson, Karl-Jonas
    Stockholm University.
    Studies of the anomeric center: mechanism and synthesis2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is based on three publications and one appendix and is divided into two parts. The first part is a mechanistic study of the anomerization reaction of both aldo and keto glycosides and the second part is a synthetic study of a unusual type of glycosidic linker found in the lipopolysaccharide core Proteus Mirabilis 0270.

    The first chapter contains a general introduction to the thesis.The second chapter treats the anomerization reaction of alkyl furanosides both by trapping experiments and kinetics. The conclusion from these studies is that the reaction proceeds via a concerted endo-cyclic C-O bond cleavage.The third chapter concerns the anomerization of alkyl pyranosides by the same techniques as those used in chapter 2. The results from these studies confirm that the reaction proceeds via exo-cyclic C-O bond cleavage.In the fourth chapter the anomerization of methyl fructosides has been investigated by trapping experiments. The outcome of this study is that the anomerization of fructosides occur via exo-cyclic C-O bond cleavage and that the anomerization reaction proceeds faster than ring-interconverison.In the final chapter an analogue of the unusual type of glycosidic linker fond in Proteus Mirabilis 0270 has been synthesised i.e. methyl ((1S)-arabinosyl o-(1Æ4,6))-a-D-galactopyranoside.

  • 16.
    Jonasson, Catrin
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Palladium (II)-catalyzed oxidations of allenes and conjugated dienes2000Doctoral thesis, comprehensive summary (Other academic)
  • 17. Kaiser, N F K
    et al.
    Bremberg, U
    Larhed, M
    Moberg, C
    Hallberg, A
    Fast, convenient, and efficient molybdenum-catalyzed asymmetric allylic alkylation under noninert conditions: An example of microwave-promoted fast chemistry2000In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 39, no 20, p. 3596-3598Article in journal (Refereed)
  • 18. Kaiser, N F K
    et al.
    Bremberg, U
    Larhed, M
    Moberg, C
    Hallberg, A
    Microwave-mediated palladium-catalyzed asymmetric allylic alkylation; an example of highly selective fast chemistry2000In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 603, no 1, p. 2-5Article in journal (Refereed)
    Abstract [en]

    Highly enantioselective palladium-catalyzed microwave-mediated fast chemistry has been performed on dimethyl malonate alkylation of(rac)-1,3-diphenylallyl-1-acetate (1). Utilizing the recently developed palladium-phosphineoxazoline catalytic system, with general stability at elevated temperatures (less than or equal to 145 degrees C), quantitative yields of greater than or equal to 97% and ee values of up to >99% were obtained after very short irradiation times (15-300 s, TOF up to 7000 h(-1)). (C) 2000 Elsevier Science S.A. All rights reserved.

  • 19.
    Karlström, A. Sofia E.
    Stockholm University.
    Copper- and nickel-catalyzed cross-coupling reactions: synthesis of 2-substituted 1,3-dienes and mechanistic and synthetic studies of the copper-mediated allylic substitution reaction2000Doctoral thesis, comprehensive summary (Other academic)
  • 20. Langlet, Abraham
    et al.
    Latypov, Nikolaj
    Wellmar, Ulf
    Goede, P.
    Bergman, Jan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Synthesis and reaction of 5,5-dinitrobarbituric acid2000In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Tetrahedron letters, Vol. 41, no 12, p. 2011-2013Article in journal (Refereed)
    Abstract [en]

    Nitration of barbituric acid at 40°C gave the previously unknown 5,5- dinitrobarbituric acid (3), which readily underwent hydrolysis to dinitroacetylurea (5), which in turn could be hydrolysed in basic media to the potassium salt of dinitromethane. Alloxane was prepared in a one step procedure by thermal decomposition of 5,5-dinitrobarbituric acid in hot acetic acid.

  • 21.
    Lindström, Ulf
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Synthesis and [3,3]-Sigmatropic Rearrangement of Vinylaziridines2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [sv]

    A general synthetic route from vinylepoxides to vinylaziridines via 1,2-amino alcohols was developed. The 1,2-amino alcohols were obtained from a stereospecific and regioselective aminolysis of vinylepoxides. The synthetic scope of the aminolysis could be expanded by the use of a microwave-assisted protocol. Some of the 1,2-amino alcohols were dehydrated with PPh3/DEAD to afford N-H vinylaziridines. All of the so obtained N-H vinylaziridines were acylated to give the corresponding N-acyl vinylaziridines. When variously substituted N-acyl vinylaziridines were subjected to LiHMDS in THF, the resulting amide enolates underwent a stereoselective aza-[3,3]-Claisen rearrangement to give mono-, di- and trisubstituted seven-membered lactams. The scope and limitations of the rearrangement were investigated. Finally, the aminolysis of vinylepoxides was applied in an asymmetric synthesis of (+)-1-deoxynojirimycin.

  • 22.
    Mühlman, Anna
    Stockholm University.
    Synthesis of inhibitors against the human immunodeficiency virus: diol-based inhibitors of the HIV-1 protase and 4-substituted carbocyclic nucleoside analogues2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The pandemic spread of HIV infection and AIDS has resulted in intensive research designed to develop effective therapeutic agents. Development of inexpensive inhibitors is necessary to allow treatment of HIV infections in the Third World.

    In the present thesis, the design and synthesis of several inhibitors of the HIV-1 virus are described. The first section presents a general overview of the life-cycle of HIV, i.e., the replication cycle and the functions of the HIV reverse transcriptase and HIV protease, as well as the strategies underlying anti-HIV chemotherapy. The design of C2-symmetric inhibitors of the HIV-1 protease, incorporating C-terminal duplication is also outlined. On the basis of molecular modelling, L-mannaric acid was selected as a general scaffold, i.e., the chiral template from which carbohydrate-based inhibitors were developed. By varying the pattern of substitution on this L-mannaric acid template, structural analogues that retained high anti-HIV activity were designed.

    The second section of the thesis describes four different syntheses of the C2-symmetric inhibitors of the HIV-1 protease, two of which provide access to potent inhibitors in a relatively few steps. These procedures open the possibility of developing cost-effective drugs.

    Finally, construction and synthesis of two 4-substituted carbocyclic nucleoside analogues, targeted against the HIV reverse transcriptase, are described.

  • 23.
    Nicholls, Ian A.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Andersson, Håkan S.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Thermodynamic principles underlying molecularly imprinted polymer formation and ligand recognition2000Other (Other academic)
  • 24.
    Olofsson, Berit
    et al.
    Royal Institute of Technology, Sweden.
    Khamrai, Uttam
    Royal Institute of Technology, Sweden.
    Somfai, Peter
    Royal Institute of Technology, Sweden.
    A regio- and stereodivergent synthesis of vic-amino alcohols2000In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 2, no 25, p. 4087-4089Article in journal (Refereed)
    Abstract [en]

    A regio- and stereodivergent synthesis of vic-amino alcs., e.g., I, starting from vinylepoxides is described. The developed strategy focuses on the propensity of vinylepoxides II and vinylaziridines III (R = PhCH2O, PhCH2, 4-MeOC6H4CH2O, R1 = H, CH2OCH2C6H4OMe-4) to be ring-opened at the allylic position by suitable nucleophiles and makes use of reactions that perform such tasks selectively with either retention or inversion of configuration.

  • 25. Olofsson, K
    et al.
    Larhed, M
    Hallberg, A
    Highly regioselective palladium-catalyzed beta-arylation of N,N-dialkylallylamines2000In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 65, no 21, p. 7235-7239Article in journal (Refereed)
  • 26.
    Salakdeh, Esmail Yousefi
    Stockholm University.
    Synthesis of nucleotide, peptide and lipid containing molecular tools for life science studies2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is based on five parts. The first and second chapters describes two synthetic routes, employing different protecting group strategies for synthesis of uridine 3'-(ethyl, 2-ethoxyethyl, 2-chloroethyl, 2,2-dichloroethyl and 2,2,2-trichloroethyl) phosphate. In the first synthetic route, uridine was protected with acid labile protecting groups, 4-methoxytetrahydropyran-4-yl for the 2'-OH group and 4-methoxytriphenylmethyl for the 5'-OH group. In the second synthesis route the tert-butyldimethylsilyl (TBDMS) was used for protection of the 2'- and 5'- hydroxyls. Silyl deprotection was performed using triethylamine trihydrofluoride.

    In the third chapter a method for O- and S-palmitoylation of non-protected peptides is described. The procedure consists of treatment of the peptides with excess of palmitoyl chloride in neat trifluoroacetic acid for 10 minutes at room temperature. The tripeptides Gly-Cys-Phe and Gly-Ser-Phe were S- and O-palmitoylated and the hydrophobic Pulmonary Surfactant Protein-C model peptides were converted to the respective S,S- and O,O-dipalmitoylated peptides.

    The production of S-citronellyl-L-cysteine and S-dolicyl-L-cysteines for use as mass spectrometry standards is described in chapter four. For formation of the thioether linkage, a mesylated citronellol and/or mesylated dolichols and L-cysteine ethyl ester were employed.

    Finally, in the last chapter a route for synthesis of 8-aminoadenosine 5'-(aminoalkyl phosphates), analogues of aminoacyl adenylates is described. The 5'-H-phosphonate of 2', 3'-O, O-benzylidene-8-bromoadenosine, with unprotected base was condensed with benzyloxycarbonyl (Z) protected amino alcohols (L-isoleucinol, L-histidinol and L-methioninol), in the presence of bis(2-oxo-oxazoline-3-yl)phosphonic chloride. After oxidation the 8-bromo was transformed into the 8-azido moiety by sodium azide in dimethyl sulfoxide. Deprotection of the benzylidene and benzyloxycarbonyl (Z) groups as well as reduction of the azido to the desired amino function was accomplished in a single step by catalytic transfer hydrogenation (palladium-carbon or palladium black in 80% acetic acid).

  • 27.
    Sjöström, A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Tolmachev, V.
    Koziorowski, J.
    Lebeda, O.
    Einarsson, L.
    Sjöberg, S.
    Carlsson, J.
    Lundqvist, H.
    Direct astatination of a peptide, human epidermal growth factor, using nido-carborane as a prosthetic group2000In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 21, no 6, p. 594-Article in journal (Refereed)
  • 28.
    Staaf, Mikael
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Structural and conformational studies of bacterial polysaccharides employing NMR spectroscopy2000Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Methods and approaches for performing structural and conformational analysis of bacterial polysaccharides in solution are described. The structure of one exopolysaccharide from Lactobacillus helveticus and two O-antigens from Escherichia coli have been determined using NMR spectroscopy, chemical degradation and mass spectrometry. This thesis discusses different problems encountered in connection with these structural elucidations, namely, overlap of NMR signals, heterogeneity in the polysaccharide sequence and the configurations of a nonulosonic acid.

    A conformational analysis of the enterobacterial common antigen (ECA) in the form of a cyclic dodecamer is described. Nuclear Overhauser effects (NOEs) and heteronuclear three-bond coupling constants (3JCH) over the glycosidic linkages were determined and used to calculate proton-proton distances and torsion angles. Residual dipolar couplings were measured in a liquid crystalline medium. These couplings provide orientational information distinct from that contained in the local NOE and 3JCH data. The experimental data were compared to the averaged distances, three-bond proton-carbon coupling constants and C-H vector orientations in a model obtained by molecular dynamics simulations. From a fragment that were in agreement with experimental data, a three-dimensional structure was generated for the cyclic ECA in solution

  • 29. Strandh, Magnus
    et al.
    Andersson, Håkan S.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ohlson, Sten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Weak Affinity Chromatography2000Book (Other academic)
  • 30. Södergren, Mikael
    et al.
    Bertilsson, Sophie
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Allylic Alcohols via Catalytic Asymmetric Epoxide Rearrangement2000In: J. Am. Chem. Soc., no 122, p. 6610-6619Article in journal (Refereed)
  • 31.
    Turek, Dominika
    Stockholm University.
    Synthesis of complex carbohydrates corresponding to the Lewis b blood group antigen and Vibrio cholerae polysaccharide structures2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is divided into two parts. The first part describes the syntheses of the Lewis b blood group antigen hexasaccharide and parts thereof. The Leb blood group antigen is one of the binding epitopes for the Helicobacter pylori bacteria in the human stomach. The oligosaccharides containing N-acetyl glucosamine, galactose and fucose, were synthesised as their 8-methoxycarbonyloctyl or 2-azidoethyl spacer glycosides and were conjugated to proteins using activated esters or the diethyl squarate methodology for binding studies with H. pylori. In the second part, structures from the lipopolysaccharide and capsular polysaccharide of Vibrio cholerae O139 synonym Bengal and Vibrio cholerae O22 were synthesised as 2-(4-benzyloxyamidophenyl)ethyl spacer glycosides for the study of their immunological properties. Unusual features of these oligosaccharides are the presence of a 6-membered cyclic phosphate diester and the 2,6-dideoxysugar colitose.

    The glycosylation reactions included halide-assisted couplings of the bromosugars of fucose and colitose, AgOTf promotion of galactosyl bromides, and DMTST or NIS promotion of thioethyl glycosides.

  • 32. Vallin, K S A
    et al.
    Larhed, M
    Johansson, K
    Hallberg, A
    Highly selective palladium-catalyzed synthesis of protected alpha,beta-unsaturated methyl ketones and 2-alkoxy-1,3-butadienes. High-speed chemistry by microwave flash heating2000In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 65, no 15, p. 4537-4542Article in journal (Refereed)
    Abstract [en]

    A selective and mild procedure is described for the direct synthesis of 2-alkene-2-methyl-1,3-dioxolanes via regiocontrolled Heck vinylation of commercially available 2-hydroxyethyl vinyl ether. The procedure permits chemoselective transformation of a vinylic triflate or bromide into a blocked alpha,beta-unsaturated methyl ketone. Furthermore, a significantly improved and highly regioselective synthesis of 2-alkoxy-1,3-butadienes has been developed. Flash heating by microwave irradiation promotes the palladium-catalyzed reactions, and the starting materials are fully converted after reaction times of 5-7 min.

  • 33. Witt, A
    et al.
    Bergman, Jan
    Södertörn University, Avdelning Naturvetenskap.
    Synthesis and reactions of some 2-vinyl-3H-quinazolin-4-ones2000In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 56, no 37, p. 7245-7253Article in journal (Refereed)
    Abstract [en]

    A simple, high-yielding synthesis of 2-vinyl-3H-quinazolin-4-one, 2-(1-chlorovinyl)-3H-quinazolin-4-one and 2-(1-bromovinyl)-3H-quinazolin-4-one. The 2-vinylquinazolinones 11a and 14 participate readily in nucleophilic addition reactions. Treatment with both carbon and nitrogen nucleophiles results in a clean conversion into a variety of 2-substituted 3H-quinazolin-4-one derivatives. The 2-(1-halovinyl)-3H-quinazolin-4-ones 11b and Ile reacted with carbon nucleophiles to give several derivatives of 2-substituted 3H-quinazolin-4-one, such as dihydrofurancarboxylic ethyl ester 23.

  • 34.
    Zamaratski, Edouard
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Bioorganic Chemistry.
    Some Aspects of Nucleic Acids Chemistry2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is divided into two parts based on a total of 8 papers: Part 1: Synthesis, physicochemical and biochemical studies of chemically modified oligonucleotides and their duplexes and triplexes. Potency of the chromophore conjugated DNA oligonucleotides as antigene and antisense gene repressors was evaluated. The effect of geometry, bulk and ¥ð-electron density of a series of chromophores, tethered at the 5'-end of oligonucleotides, as well as the effect of the linker nature, length and the attachment site of the chromophore to the oligo were explored based on the stability of the duplexes and triplexes. A dramatic improvement in the triplex stability with ara-U linked phenazine oligo (potent antigene) was achieved (¥ÄTm = 16.5¢ª C). A number of selected phenazine and dipyridophenazine tethered antisense oligos (AONs) and their phosphorothioate analogues were shown to form the AON/RNA hybrid duplexes with enhanced thermal stability. CD experiments revealed that these duplexes have the global structure unaltered from that of the native counterpart. RNase H degradation studies on three RNA targets having different degrees of folded structures showed that tethering of phenazine and dipyridophenazine increases the hydrolysis rates (potent antisense) of the target RNA, and that chemical nature of the chromophore influences the RNase H cleavage pattern. Further investigation at the RNA saturated conditions revealed that 3'-tethered chromophores influence the substrate recognition, and the kinetics of the cleavage by RNase H. Conjugation of different chromophores, charged polyaromatic systems and metal complexes with polyaromatic ligands at different sites of the AON revealed that RNase H is very sensitive to any modifications in the middle region of the AON/RNA duplex. On the contrary, any modification at the 3'-end of the AON regardless of the bulk of the substituent or presence of positive charge can be easily tolerated by the enzyme. Sensitivity of the RNase H towards the local structural changes in the AON/RNA hybrid was probed with a number of AONs containing a single 1-(1',3'-O-anhydro-©¬-D-psicofuranosyl)thymine with locked 3'-endo sugar conformation at different sites of AON. RNase H degradation studies revealed that the local conformational changes brought by the constrained nucleoside, although invisible by CD, span in the hybrid as far as 5 nucleotides toward the 5'-end of the AONs (3'-end of RNA), showing the unique transmission of the structural distortion from a single modification site. The results also showed that the structural requirements for the substrate binding and substrate cleavage by RNase H appear to be different. Part 2: Preparation of biologically important isotope labelled oligo-RNAs for the NMR structure determination in solution. Synthesis of the non-uniformly 13C5 labelled 29mer HIV-1 TAR RNA was achieved by solid-phase synthesis using 13C5 labelled ribonucleosides from 13C6-D-glucose). Two hammerhead forming RNAs (16mer and 25mer) were synthesized according to the Uppsala NMR-window strategy, where the sugar residues of the nucleosides forming stem I, II and the loop of the stem III of the resulting hammerhead complex were deuterated. UV melting and high resolution NMR structural studies showed that the 16mer RNA under quasiphysiological condition folds to a very stable hairpin structure, which prevents formation of a hammerhead RNA with the 25mer, primarily owing to thermodynamic reasons.

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