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  • 1.
    An, Junxue
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Duan, Lele
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    The Ru complexes containing pyridine-dicarboxylate ligand: electronic effect on their catalytic activity toward water oxidation2011In: Faraday discussions (Online), ISSN 1359-6640, E-ISSN 1364-5498, Vol. 155, p. 267-275Article in journal (Refereed)
    Abstract [en]

    Two series of mononuclear ruthenium complexes [Ru(pdc)L-3] (H(2)pdc = 2,6-pyridinedicarboxylic acid; L = 4-methoxypyridine, 1; pyridine, 2; pyrazine, 3) and [Ru(pdc)L-2(dmso)] (dmso = dimethyl sulfoxide; L = 4-methoxypyridine, 4; pyridine, 5) were synthesized and spectroscopically characterized. Their catalytic activity toward water oxidation has been examined using Ce-IV (Ce(NH4)(2)(NO3)(6)) as the chemical oxidant under acidic conditions. Complexes 1, 2 and 3 are capable of catalyzing Ce-IV-driven water oxidation while 4 and 5 are not active. Electronic effects on their catalytic activity were illustrated: electron donating groups increase the catalytic activity.

  • 2.
    Anderson, Mattias
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Afewerki, Samson
    Berglund, Per
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Córdova, Armando
    Chemoenzymatic amination of alcohols by combining oxidation catalysts with transaminases in one potManuscript (preprint) (Other academic)
    Abstract [en]

    Chemoenzymatic methods for the amination of alcohols have been developed. The reactions were performed in a one-pot two-step fashion, where the alcohol starting material was first oxidized to the corresponding carbonyl compound and then subsequently converted to the amine product with an enzymatic system based on an amine transaminase. The enzyme system was able to operate in a water/organic solvent two-phase system in the presence of either a heterogeneous palladium(0) catalyst or a homogeneous copper(I) catalyst. High conversions to the product amines were achieved for a range of substituted benzyl alcohols and similar compounds, but unfortunately the use of aliphatic alcohols resulted in lower conversions and secondary alcohols could not be converted to the corresponding amines with this methodology.

  • 3.
    Andersson, Samir
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    An efficient water oxidation system based on supramolecular assembly of molecular catalyst and cucurbit[7]urilManuscript (preprint) (Other academic)
  • 4.
    Andersson, Samir
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zou, Dapeng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Rong
    Sun, Shiguo
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Light driven formation of a supramolecular system with three CB 8 s locked between redox-active Ru(bpy)(3) complexes2009In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 7, no 17, p. 3605-3609Article in journal (Refereed)
    Abstract [en]

    Three CB[8]s have been reversibly locked between two Ru(bpy)(3)-viologen complexes by light driven electron transfer reactions.

  • 5. 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

  • 6.
    Angelin, Marcus
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Discovery-Oriented Screening of Dynamic Systems: Combinatorial and Synthetic Applications2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is divided into six parts, all centered around the development of dynamic (i.e., reversibly interacting) systems of molecules and their applications in dynamic combinatorial chemistry (DCC) and organic synthesis.

    Part one offers a general introduction, as well as a more detailed description of DCC, being the central concept of this thesis. Part two explores the potential of the nitroaldol reaction as a tool for constructing dynamic systems, employing benzaldehyde derivatives and nitroalkanes. This reaction is then applied in part three where a dynamic nitroaldol system is resolved by lipase-catalyzed transacylation, selecting two out of 16 components.

    In part four, reaction and crystallization driven DCC protocols are developed and demonstrated. The discovery of unexpected crystalline properties of certain pyridine β-nitroalcohols is used to resolve a dynamic system and further expanded into asynthetic procedure. Furthermore, a previously unexplored tandem nitroaldol-iminolactone rearrangement reaction between 2-cyanobenzaldehyde and primarynitroalkanes is used for the resolution of dynamic systems. It is also coupled with diastereoselective crystallization to demonstrate the possibility to combine several selection processes. The mechanism of this reaction is investigated and a synthetic protocol is developed for asymmetric synthesis of 3-substituted isoindolinones.

    Part five continues the exploration of tandem reactions by combining dynamic hemithioacetal or cyanohydrin formation with intramolecular cyclization to synthesize a wide range of 3-functionalized phthalides.

    Finally, part six deals with the construction of a laboratory experiment to facilitate the introduction of DCC in undergraduate chemistry education. The experiment is based on previous work in our group and features an acetylcholinesterase-catalyzed resolution of a dynamic transthioacylation system.

  • 7.
    Angelin, Marcus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Crystallization-induced secondary selection from a tandem driven dynamic combinatorial resolution process2008In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 73, no 9, p. 3593-3595Article in journal (Refereed)
    Abstract [en]

    Crystallization-induced secondary selection from a tandem driven dynamic combinatorial library is presented. In a one-pot experiment, an initial nitroaldol equilibrium was kinetically driven by a tandem reaction resulting in a subsequent dynamic library of diastereoisomers. This library was then further driven by a phase change, resulting in amplification and isolation of a highly diastereomerically enriched and synthetically interesting isoindolinone.

  • 8.
    Angelin, Marcus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Larsson, Rikard
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Vongvilai, Pornrapee
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Introducing Dynamic Combinatorial Chemistry: Probing the Substrate Selectivity of Acetylcholinesterase2010In: Journal of Chemical Education, ISSN 0021-9584, E-ISSN 1938-1328, Vol. 87, no 11, p. 1248-1251Article in journal (Refereed)
  • 9.
    Angelin, Marcus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Rahm, Martin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Fischer, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Diastereoselective One-Pot Tandem Synthesis of 3-Substituted Isoindolinones: A Mechanistic Investigation2010In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 75, no 17, p. 5882-5887Article in journal (Refereed)
    Abstract [en]

    The mechanism of a base-catalyzed one-pot reaction of 2-cyanobenzaldehyde and primary nitroalkanes, to produce 3-substituted isoindolinones, has been investigated. A route starting with a nitroaldol (Henry) reaction, followed by a subsequent cyclization and rearrangement, was supported by intermediate analogue synthesis and DFT calculations. Direct diastereoselective crystallization from the reaction mixture was also achieved and studied for a number of substrates. Furthermore, the 3-substituted isoindolinones are an interesting group of compounds, both present important natural products, as well as being precursors to other valuable building blocks.

  • 10. Ashitani, T.
    et al.
    Kusumoto, N.
    Borg-Karlson, Anna Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Fujita, K.
    Takahashi, K.
    Antitermite activity of β-caryophyllene epoxide and episulfide2013In: Zeitschrift für Naturforschung C - A Journal of Biosciences, ISSN 0939-5075, E-ISSN 1865-7125, Vol. 68 C, no 7-8, p. 302-306Article in journal (Refereed)
    Abstract [en]

    Caryophyllene-6,7-epoxide and caryophyllene-6,7-episulfide can be easily synthesized from β-caryophyllene by autoxidation or episulfidation. The bioactivities of β-caryophyllene and its derivatives were investigated against the subterranean termite Reticulitermes speratus Kolbe. The antifeedant, feeding, and termiticidal activities of each compound were tested using no-choice, dual-choice, and non-contact methods. Antitermitic activities were not shown by β-caryophyllene, but were observed for the oxide and sulfide derivatives. Caryophyllene- 6,7-episulfide showed especially high antifeedant and termiticidal activities. Thus, naturally abundant, non-bioactive β-caryophyllene can be easily converted into an antitermite reagent via a non-biological process.

  • 11.
    Axelsson, Karolin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Chemical signals in interactions between Hylobius abietis and associated bacteria2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The pine weevil (Hylobius abietis L.) is one of the two topmost economically important insect pests in Swedish conifer forests. The damage increase in areas were the silvicultural practice is to use clear cuttings were the insects gather and breed. During egglaying the female protects her offspring by creating a cave in roots and stumps were she puts her egg and covers it with frass, a mixture of weevil feces and chewed bark. Adult pine weevils have been observed to feed on the other side of the egg laying site and antifeedant substance has been discovered in the feces of the pine weevil. We think it is possible that microorganisms present in the frass contribute with antifeedant/repellent substances. Little is known about the pine weevils associated bacteria community and their symbiotic functions. In this thesis the bacterial community is characterized in gut and frass both from pine weevils in different populations across Europe as well as after a 28 day long diet regime on Scots pine, silver birch or bilberry. Volatile substances produced by isolated bacteria as well as from a consortium of microorganisms were collected with solid phase micro extraction (SPME) and analyzed with GC-MS. The main volatiles were tested against pine weevils using a two-choice test. Wolbachia, Rahnella aquatilis, Serratia and Pseudomonas syringae was commonly associated with the pine weevil. 2-Methoxyphenol, 2-phenylethanol, 3-methyl-1-butanol were found in the headspace from Rahnella aquatilis when grown in substrate containing pine bark. 2-Methoxyphenol and 3-methyl-1-butanol, phenol and methyl salicylate were found in pine feces. Birch and bilberry feces emitted mainly linalool oxides and bilberry emitted also small amounts of 2-phenylethanol.

    A second part of the thesis discusses the role of fungi in forest insect interactions and the production of oxygenated monoterpenes as possible antifeedants. Spruce bark beetles (Ips typhographus L.) aggregate with the help of pheromones and with collected forces they kill weakened adult trees as a result of associated fungi growth and larval development. A fungi associated with the bark beetle, Grosmannia europhoides, was shown to produce de novo 2-methyl-3-buten-2-ol, the major component of the spruce bark beetle aggregation pheromone. Chemical defense responses against Endoconidiophora polonica and Heterobasidion parviporum were investigated using four clones of Norway spruce with different susceptibility to Heterobasidion sp. Clone specific differences were found in induced mono-, sesqui and diterpenes. A number of oxygenated monoterpenes which are known antifeedants for the pine weevil were produced in the infested areas.

  • 12.
    Axelsson, Karolin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Konstanzer, Vera
    Kuttuva Rajarao, Guna
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Terenius, Olle
    Dep of Ecology, SLU.
    Seriot, Lisa
    Nordenhem, Henrik
    Dep. of Ecology, SLU.
    Nordlander, Göran
    Dep. of Ecology, SLU.
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Antifeedants produced by bacteria associated to the gut of the pine weevil (Hylobius abietis)Manuscript (preprint) (Other academic)
  • 13.
    Axelsson, Karolin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Nilsson, Louise
    Nordlander, Göran
    Dep. of Ecology, SLU.
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Terenius, Olle
    Dep of Ecology, SLU.
    Do pine weevil microbiota and corresponding volatiles change due to selective feeding?Manuscript (preprint) (Other academic)
  • 14.
    Axelsson, Karolin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zendegi-Shiraz, Amene
    Swedjemark, Gunilla
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhao, Tao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Clone specific chemical defense responses in Norway spruce to infestations by two pathogenic fungi2016In: Forest Pathology, ISSN 1437-4781, E-ISSN 1439-0329Article in journal (Other academic)
    Abstract [en]

    Heterobasidion parviporum (Hp) were investigated using four clones of Norway spruce (Picea abies) with different susceptibility to Heterobasidion sp. Eight year old trees were inoculated with Ep and Hp to minimize the variation due to environment. After three weeks the bark tissue at the upper border of the inoculation hole were extracted with hexane and analyzed by GC-MS. Both treatment and clonal differences were found based on induced mono-, sesqui- and diterpenes. In addition, the Hp produced toxin, fomanoxin, was identified in lowest amount in the most Hp susceptible clone. The clonal trees seem to use different defense strategies towards the two fungi. One of the clones was able to induce strong chemical defense against both fungi, one clone induced chemical defense only against Ep and the most susceptible clone exhibited the least capacity to produce an effective defense against Ep and Hp. Two diterpenes were found to be distinctly different between clones with different susceptibilities, which can be used as chemical indication of Norway spruce resistance against fungi.

  • 15.
    Azeem, Muhammad
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Microbes Associated with Hylobius abietis: A Chemical and Behavioral Study2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is based on three inter-related studies: the first part deals with the microbial consortium, the identification of microbes and their volatiles, the second part deals with the study of bio-chemical control methods of two conifer pests; the pine weevil Hylobius abietis (L.) and the root rot fungi Heterobasidion spp., and the third part describes the production of styrene by a fungus using forest waste.The large pine weevil (Hylobius abietis L.) is an economically important pest insect of conifers in reforestation areas of Europe and Asia. The female weevils protect their eggs from feeding conspecifics by adding frass (mixture of weevil feces and chewed bark) along with the eggs. In order to understand the mechanism behind frass deposition at the egg laying site and to find repellents/antifeedants for pine weevils, microbes were isolated from the aseptically collected pine weevil frass. Microbial produced volatile organic compounds (VOCs) were collected by solid phase micro extraction and analyzed by GC-MS after cultivating them on weevil frass broth. The major VOCs were tested against pine weevils using a multi-choice olfactometer. Ewingella sp., Mucor racemosus, Penicillium solitum, P. expansum, Ophiostoma piceae, O. pluriannulatum, Debaryomyces hansenii and Candida sequanensis were identified as abundant microbes. Styrene, 6-protoilludene, 1-octene-3-ol, 3-methylanisole, methyl salicylate, 2-methoxyphenol and 2-methoxy-4-vinylphenol were the VOCs of persistently isolated microbes. In behavioral bioassay, methyl salicylate, 3-methylanisole and styrene significantly reduced the attraction of pine weevils to their host plant volatiles. Heterobasidion spp. are severe pathogenic fungi of conifers that cause root and butt rot in plants. Bacterial isolates were tested for the antagonistic activity against fungi on potato dextrose agar. Bacillus subtilis strains significantly inhibited the growth of H. annosum and H. parviporum. Styrene is an industrial chemical used for making polymeric products, currently produced from fossil fuel. A strain of Penicillium expansum isolated from pine weevil frass was investigated for the production of styrene using forest waste. Grated pine stem bark and mature oak bark supplemented with yeast extract produced greater amounts of styrene compared to potato dextrose broth.

  • 16.
    Bah, Juho
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Metal-Free Catalysis for Efficient Synthesis2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The strength of efficient metal-free catalysis will be examined in this thesis. Efforts towards more sustainable processes will be demonstrated through implementation of strategies that meet several of the 12 principles of Green Chemistry.In the first part, a stereoselective total synthesis of multiple alkaloids from the Corynantheine and Ipecac families together with their non-natural analogues will be disclosed. A highly efficient, common synthetic strategy is applied leading to high overall yields starting from easily available starting material. Overall operational simplicity and sustainability have been the main focus. Time-consuming and waste-generating isolations and purifications of intermediates have been minimized, as well as the introduction of protection-group chemistry. Moreover, the first example of the total synthesis of Hydroxydihydrocorynantheol together with its non-natural epimer has been accomplished in multi-gram scale without protection groups and without a single isolation or purification step in high overall yield and diastereoselectivity.In the second part, carbocations will be presented as highly effective and versatile non-metal Lewis acid catalysts. Lewis acidity-tuning of carbocations will be introduced and applied in several reactions to suppress competing reactions. Finally, the broad scope of carbocation catalyzed transformations will be exposed.At large, evident progress has been made towards more sustainable chemistry.

  • 17.
    Bah, Juho
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Naidu, Veluru Ramesh
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Teske, Johannes
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Franzén, Johan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Carbocations as Lewis Acid Catalysts: Scope and Reactivity2015In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 357, no 1, p. 148-158Article in journal (Refereed)
    Abstract [en]

    One class of potential Lewis acids that has received negligible attention as a catalyst is the carbocation. Here we show the potential of triarylmethylium ions as highly powerful Lewis acid catalysts for organic reactions. The Lewis acidity of the triarylmethylium ion can be easily tuned by variation of the electronic properties of the aromatic rings and the catalytic activity of the carbocation is shown to correlate directly to the level of stabilization of the empty p(C)-orbital at the cationic carbon. The versatility of triarylmethylium ions as efficient Lewis acid catalysts for organic reactions is demonstrated in Diels-Alder, aza-Diels-Alder, conjugate addition, halogenation, epoxide rearrangement and intramolecular hetro-ene reactions.

  • 18. Bassanini, Ivan
    et al.
    Hult, Karl
    KTH, School of Biotechnology (BIO), Industrial Biotechnology. CNR, Italy.
    Riva, Sergio
    Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers2015In: Beilstein Journal of Organic Chemistry, ISSN 2195-951X, E-ISSN 1860-5397, Vol. 11, p. 1583-1595Article, review/survey (Refereed)
    Abstract [en]

    Dicarboxylic acids and their derivatives (esters and anhydrides) have been used as acylating agents in lipase-catalyzed reactions in organic solvents. The synthetic outcomes have been dimeric or hybrid derivatives of bioactive natural compounds as well as functionalized polyesters.

  • 19. Bednarska, Joanna
    et al.
    Zalesny, Robert
    Tian, Guangjun
    Natarajan Arul, Murugan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Bartkowiak, Wojciech
    Nonempirical Simulations of Inhomogeneous Broadening of Electronic Transitions in Solution: Predicting Band Shapes in One- and Two-Photon Absorption Spectra of Chalcones2017In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 22, no 10, article id 1643Article in journal (Refereed)
    Abstract [en]

    We have examined several approaches relying on the Polarizable Embedding (PE) scheme to predict optical band shapes for two chalcone molecules in methanol solution. The PE-TDDFT and PERI-CC2 methods were combined with molecular dynamics simulations, where the solute geometry was kept either as rigid, flexible or partly-flexible (restrained) body. The first approach, termed RBMD-PE-TDDFT, was employed to estimate the inhomogeneous broadening for subsequent convolution with the vibrationally-resolved spectra of the molecule in solution determined quantum-mechanically (QM). As demonstrated, the RBMD-PE-TDDFT/QM-PCM approach delivers accurate band widths, also reproducing their correct asymmetric shapes. Further refinement can be obtained by the estimation of the inhomogeneous broadening using the RBMD-PERI-CC2 method. On the other hand, the remaining two approaches (FBMD-PE-TDDFT and ResBMD-PE-TDDFT), which lack quantum-mechanical treatment of molecular vibrations, lead to underestimated band widths. In this study, we also proposed a simple strategy regarding the rapid selection of the exchange-correlation functional for the simulations of vibrationally-resolved one-and two-photon absorption spectra based on two easy-to-compute metrics.

  • 20.
    Bellini, Rosalba
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Magre, Marc
    Biosca, Maria
    Norrby, Per-Ola
    Pamies, Oscar
    Dieguez, Montserrat
    Moberg, Christina
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Conformational Preferences of a Tropos Biphenyl Phosphinooxazoline-a Ligand with Wide Substrate Scope2016In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 6, no 3, p. 1701-1712Article in journal (Refereed)
    Abstract [en]

    Excellent enantioselectivities are observed in palladium-catalyzed allylic substitutions of a wide range of substrate types and nucleophiles using a bidentate ligand composed of oxazoline and chirally flexible biaryl phosphite elements. This unusually wide substrate scope is shown by experimental and theoretical studies of its eta(3)-allyl and eta(2)-olefin complexes not to be a result of configurational interconversion of the biaryl unit, since the ligand in all reactions adopts an S-a,S configuration on coordination to palladium, but rather the ability of the ligand to adapt the size of the substrate-binding pocket to the reacting substrate. This ability also serves as an explanation to its excellent performance in other types of catalytic processes.

  • 21.
    Bengtsson, Linda
    KTH, School of Chemical Science and Engineering (CHE).
    Odorant binding protein and olfactory receptors: plausible role as detectors in an odorant biosensor2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The development of an inexpensive, portable, stable, sensitive and selective biosensor for detection of odorants is a daunting task. Here, we hypothesized the development of a detector layer composed of the protein groups; the olfactory receptors (ORs) and the odorant binding proteins (OBPs), known to bind odorants in animal sensing. We report the design of 13 OR gene-vector constructs, and their subsequent transformation into

    Escherichia (E.) coli (BL21 (DE3)-STAR-pLysS) strain. Moreover, we report the expression of several ORs into an in vitro wheat germ extract using three separate detergent mixes for protein solubilization.

     

    In addition, we describe the design of an odorant binding protein from the Aenopheles gambiae mosquito PEST strain (OBP-PEST) gene-vector construct under an IPTG (Isopropyl β-D-1-thiogalactopyranoside) inducible promoter. OBP-PEST was heterologously expressed in E.coli with an 8 amino acid long sequence (WSPQFEK) attached C-terminally, via a thrombin cleavage site and a flexible linker (GSSG). The WSPQFEK sequence, commonly referred to as a Strep-tag, enabled subsequent affinity chromatography purification of the protein, via binding to an engineered Streptavidin equivalent. Surprisingly, the OBP-PEST was found to contain a signal sequence leading to its truncation and secretion when expressed in E.coli.

     

    Biophysical analyses were established using Circular Dichroism (CD) for the analysis of two lipocalins: Beta-lactoglobulin (BLG) and OBP-PEST. We studied the solubility, refoldability and the conformational transitions of BLG, as a result of change in solvent, pH and temperature. The secondary structure of OBP-PEST and its thermal stability was investigated.

     

    In conclusion, this thesis work has enabled biophysical analyses of OBP-PEST and future analogs of interest to the development of a stable protein detector layer. Although further experiments are needed to fully characterize the biophysical properties, and to find odorant substrates of OBP-PEST, it was found to be a suitable alternative to ORs in a biosensor detector layer application. More importantly, an inherent OBP-PEST signal sequence was found to mediate protein secretion when expressed heterologously in E.coli. To the best of our knowledge this is the first lipocalin discovered to be secreted upon heterologous expression in E.coli.

     

    We hypothesize that this signal peptide could be used as a means for targeted secretion and, hence, efficient protein purification.

  • 22.
    Berglund, Per
    KTH, School of Biotechnology (BIO), Biochemistry.
    Asymmetric Organic Synthesis with Enzymes: Edited by Vicente Gotor, Ignacio Alfonso and Eduardo Garcia-Urdiales2008In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 47, no 35, p. 6514-6515Article, book review (Other academic)
  • 23.
    Berglund, Per
    KTH, Superseded Departments, Chemistry.
    Candida rugosa lipase as a catalyst in organic media: Enantioselectivity in kinetic resolutions of 2-methylalkanoic acids1995Doctoral thesis, comprehensive summary (Other academic)
  • 24.
    Berglund, Per
    et al.
    KTH, Superseded Departments, Biotechnology.
    Branneby, Cecilia
    Svedendahl Humble, Maria
    KTH, School of Biotechnology (BIO), Biochemistry (closed 20130101).
    Carlqvist, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry (closed 20110630).
    Magnusson, Anders
    Hult, Karl
    KTH, School of Biotechnology (BIO), Biochemistry (closed 20130101).
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry (closed 20110630).
    Aldol and Michael additions catalyzed by a rationally redesigned hydrolytic enzyme2003In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 226, no 2, p. U155-U156Article in journal (Refereed)
  • 25. Bergman, J.
    et al.
    Pettersson, B.
    Hasimbegovic, V.
    Svensson, Per H.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. AstraZeneca R&D, Pharmaceut Dev, Sweden.
    Thionations using a P4S10-pyridine complex in solvents such as acetonitrile and dimethyl sulfone2011In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 76, no 6, p. 1546-1553Article in journal (Refereed)
    Abstract [en]

    Tetraphosphorus decasulfide (P 4S 10) in pyridine has been used as a thionating agent for a long period of time. The moisture-sensitive reagent has now been isolated in crystalline form, and the detailed structure has been determined by X-ray crystallography. The thionating power of this storable reagent has been studied and transferred to solvents such as acetonitrile in which it has proven to be synthetically useful and exceptionally selective. Its properties have been compared with the so-called Lawesson reagent (LR). Particularly interesting are the results from thionations at relatively high temperatures (̃165 °C) in dimethyl sulfone as solvent. Under these conditions, for instance, acridone and 3-acetylindole could quickly be transformed to the corresponding thionated derivatives. Glycylglycine similarly gave piperazinedithione. At these temperatures, LR is inefficient due to rapid decomposition. The thionated products are generally cleaner and more easy to obtain because in the crystalline reagent, impurities which invariably are present in the conventional reagents, P 4S 10 in pyridine or LR, have been removed.

  • 26. Bergman, Jan
    et al.
    Arewang, Carl-Johan
    Svensson, Per H.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. SP Process Development, Sweden .
    Oxidative Ring Expansion of Spirocyclic Oxindole Derivatives2014In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 79, no 19, p. 9065-9073Article in journal (Refereed)
    Abstract [en]

    Oxidation of the spirocyclic oxindole derivative, isamic acid 1, led to decarboxylation and ring expansion to quinazolino[4,5-b]quinazoline-6,8-dione 7 rather than, as previously believed, its isomer 6. The structure of 7 was confirmed by X-ray crystallography. Condensation of isatin (indole-2,3-dione) and 2-aminobenzamide led to the spirocyclic molecule, spiro[3H-indole-3,2'(1H)quinazoline]-2,4'(1H,3H)dione 8, which was also identified as an intermediate in the oxidation of isamic acid. Mild hydrolysis of 7 gave the 10-membered molecule 22. Isamic acid could easily be converted to N-nitrosoisamic acid, which when heated in ethanol underwent a ring expansion to a hydroximino derivative, 38, of compound 6. The structure of 38 was confirmed by X-ray crystallography.

  • 27.
    Blid, Jan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Asymmetric [2,3]-Sigmatropic Rearrangement of Allylic Ammonium Ylides2005Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The thesis describes the realization of an asymmetric [2,3]-sigmatropic rearrangement of achiral allylic amines. It is divided into two parts; the first part deals with the development of a Lewis acid-mediated [2,3]-sigmatropic rearrangement and the second the asymmetric version thereof. Quaternization of an -amino amide with various Lewis acids established BBr3 and BF3 to be the most appropriate ones. Various allylic amines were subsequently rearranged into the corresponding homoallylic amines in good to excellent syn-diastereoselectivities, revealing the endo-transition state to be the preferred pathway. The structures of the intermediate Lewis acid-amine complexes were confirmed by NMR spectroscopy studies and DFT calculations.

    Based on this investigation a chiral diazaborolidine was chosen as Lewis acid and was shown to efficiently promote the asymmetric [2,3]-sigmatropic rearrangement furnishing homoallylic amines in good yields and excellent enantiomeric excesses. In contrast to the achiral rearrangement mediated by BBr3 and BF3, the asymmetric version gave the opposite major diastereomer, revealing a preference for the exo-transition state in the asymmetric rearrangement. To account for the observed selectivities, a kinetic and thermodynamic pathway was presented. On the basis of a deuterium exchange experiment on a rearranged Lewis acid-amine complex and an NMR spectroscopic investigation, the kinetic pathway was shown to be favored.

  • 28.
    Blid, Jan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Panknin, Olaf
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Tuzina, Pavel
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Lewis acid mediated asymmetric 2,3 -sigmatropic rearrangement of allylic amines. Scope and mechanistic investigation2007In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 72, no 4, p. 1294-1300Article in journal (Refereed)
    Abstract [en]

    [GRAPHIC] The first asymmetric [2,3]-sigmatropic rearrangement of achiral allylic amines has been realized by quaternization of the amines with an enantiomerically pure diazaborolidine and subsequent treatment with Et3N. The resultant homoallylic amines were obtained in good yields and excellent ee's. The observed diastereo- and enantioselectivities were rationalized by invoking a kinetically controlled process, and support for this model was obtained from an NMR spectroscopic investigation of the chiral Lewis acid-substrate complex. The structure of the Lewis acid-product complex was established by X-ray crystallographic analysis and supported the proposed mechanism.

  • 29.
    Blomkvist, Björn
    KTH, School of Chemical Science and Engineering (CHE).
    The application of reversible covalent bonds in catalysis2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work has been concerned with the study of ligand exchange of trimethylborate and its  ability to induce temporary intramolecularity. Experiments aimed at understanding the affinity of various alcohols and amines to boron centers by studying the formation of mixed borate species during equilibrium. Furthermore, a variety of reactions has been screened with the aim to perform catalysis by induced intramolecularity through the trimethylborate.

  • 30.
    Bo, Xu
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Advanced Organic Hole Transport Materials for Solution-Processed Photovoltaic Devices2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Solution-processable photovoltaic devices (PVs), such as perovskite solar cells (PSCs) and solid-state dye-sensitized solar cells (sDSCs) show great potential to replace the conventional silicon-based solar cells for achieving low-cost and large-area solar electrical energy generation in the near future, due to their easy manufacture and high efficiency. Organic hole transport materials (HTMs) play important roles in both PSCs and sDSCs, and thereby can well facilitate the hole separation and transportation, for obtaining high performance solar cells.

    The studies in this thesis aimed to develop advanced small-molecule organic HTMs with low-cost, high hole mobility and conductivity for the achievement of highly efficient, stable and reproducible sDSCs and PSCs. In order to achieve these objectives, two different strategies were utilized in this thesis: the development of new generation HTMs with simple synthetic routes and the introduction of cost-effective p-type dopants to control the charge transport properties of HTMs.

    In Chapter 1 and Chapter 2, a general introduction of the solution-processed sDSCs and PSCs, as well as the characterization methods that are used in this thesis were presented.

    In Chapter 3 and Chapter 4, a series of novel triphenylamine- and carbazole- based HTMs with different oxidation potential, hole mobility, conductivity and molecular size were designed and synthesized, and then systematically applied and investigated in sDSCs and PSCs.

    In Chapter 5, two low-cost and colorless p-type dopants AgTFSI and TeCA were introduced for the organic HTM-Spiro-OMeTAD, which can significantly increase the conductivity of the Spiro-OMeTAD films. The doping effects on the influence of sDSC and PSC device performances were also systematically investigated.

  • 31.
    Borg, Tessie
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Stereoselective Nucleophilic Additions to Aldehydes and Development of New Methodology in Organic Synthesis2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is divided into four separate parts with nucleophilic addition to aldehydes as the common feature in three of them.

    The first part deals with the investigation of the stereochemical induction and elucidation of the factors that dictate the p-facial selectivities in Mukaiyama aldol addition to a- and a,b-heteroatom substituted aldehydes. An explanation for the unexpected shift from 1,2-anti to 1,2-syn selectivity seen in the reaction when applying nucleophiles of different sizes in the addition to a-chloro aldehydes is offered.

    The next two parts describes the addition of 1,3-bis(silyl)propenes and C3 substituted 1,3-bis(silyl)propenes to aldehydes and the development of two highly stereoselective new methodologies for the construction of 1,3-dienes and 2,3,4,5-tetrasubstituted tetrahydrofuranes, respectively.

    The last part describes the attempts made towards the total synthesis of (±)-aspidophylline A, where the intention was to apply a domino carbopalladation-carbonylation reaction as the key step in the synthetic route.

  • 32.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Danielsson, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Mukaiyama aldol addition to α-chloro-substituted aldehydes. Origin of the unexpected syn selectivity.2010In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 46, no 8, p. 1281-1283Article in journal (Refereed)
    Abstract [en]

    The addition of sterically demanding enolsilanes to alpha-chloro aldehydes results unexpectedly in preferential formation of the anti-PFA product (1,2-syn), while the addition of the corresponding boron enolate furnishes the expected polar Felkin-Anh product (1,2-anti). A stereoinduction model explaining these observations is proposed.

  • 33.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Restorp, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    ORGN 988-Diastereoselective addition of nucleophiles to aldehydes having polar - and -substituents2007In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 234Article in journal (Other academic)
  • 34.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Timmer, Brian
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Diastereoselective formation of 2,3,4,5-tetrasubstituted tetrahydrofurans by a Lewis acid promoted addition of C3-substituted 1,3-bis(silyl)propenes to aldehydes2010Manuscript (preprint) (Other academic)
  • 35.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Tuzina, Pavel
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Lewis Acid-Promoted Addition of 1,3-Bis(silyl)propenes to Aldehydes: A Route to 1,3-Dienes2011In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 76, no 19, p. 8070-8075Article in journal (Refereed)
    Abstract [en]

    The Lewis acid-promoted addition of 1,3-bis(silyl)-propenes to aldehydes to provide the corresponding (E)-1,3-dienes in excellent stereoselectivity and good to excellent yields is reported. The procedure is mild, base-free, and operationally straightforward.

  • 36. Bouchet, Aude
    et al.
    Brotin, Thierry
    Linares, Mathieu
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Cavagnat, Dominique
    Buffeteaeu, Thierry
    Enantioselective Complexation of Chiral Propylene Oxide by an Enantiopure Water-Soluble Cryptophane2011In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 76, no 10, p. 4178-4181Article in journal (Refereed)
    Abstract [en]

    ECD and NMR experiments show that the complexation of propylene oxide (PrO) within the cavity of an enantiopure water-soluble cryptophane 1 in NaOH solution is enantioselective and that the (R)-PrO@PP-1 diastereomer is more stable than the (S)-PrO@PP-1 diastereomer with a free energy difference of 1.7 kJ/mol. This result has been confirmed to by molecular dynamics (MD) and ab initio calculations. The enantioselectivity is preserved in LiOH and KOH solutions even though the binding constants decrease, whereas PrO is not complexed in CsOH solution.

  • 37.
    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.

  • 38. Brotin, Thierry
    et al.
    Montserret, Roland
    Bouchet, Aude
    Cavagnat, Dominique
    Linares, Mathieu
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Buffeteau, Thierry
    High Affinity of Water-Soluble Cryptophanes for Cesium Cations2012In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 77, no 2, p. 1198-1201Article in journal (Refereed)
    Abstract [en]

    Exceptionally high affinity for cesium cations was achieved in aqueous solution using two enantiopure cryptophanes. Complexation of cesium was evidenced by Cs-133 NMR spectroscopy and by electronic circular dichroism (ECD). Binding constants as high as 6 X 10(9) M-1 have been measured by isothermal titration calorimetry (ITC). Very strong complexation of rubidium cations (K similar to 10(6) M-1) has also been measured. Chiral hosts allowed the detection of the two cations at low concentrations (mu M) using ECD.

  • 39.
    Brulé, Emilie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Hii, K K
    de Miguel, Y R
    Polymer-supported manganese porphyrin catalysts - peptide-linker promoted chemoselectivity2005In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 3, no 10, p. 1971-1976Article in journal (Refereed)
    Abstract [en]

    Manganese porphyrin catalysts were tethered to polymer-supports via peptide linkers. The reactivity and chemoselectivity of the catalysts were assessed in the epoxidation of limonene. It was found that the inclusion of a peptide linker incorporating a donor heteroatom which could act as an axial ligand led to a supported manganese porphyrin catalyst with unprecedented selectivity and stability.

  • 40.
    Butchosa, Núria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Water redispersible cellulose nanofibrils adsorbed with carboxymethyl cellulose2014In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, no 6, p. 4349-4358Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils (CNFs) are difficult to redisperse in water after they have been completely dried due to the irreversible agglomeration of cellulose during drying. Here, we have developed a simple process to prepare water-redispersible dried CNFs by the adsorption of small amounts of carboxymethyl cellulose (CMC) and oven drying. The adsorption of CMC onto CNFs in water suspensions at 22 and 121 °C was studied, and the adsorbed amount of CMC was measured via conductimetric titration. The water-redispersibility of dried CNFs adsorbed with different amounts of CMC was characterized by sedimentation test. Above a critical threshold of CMC adsorption, i.e. 2.3 wt%, the oven dried CNF–CMC sample was fully redispersible in water. The morphology, rheological, and mechanical properties of water-redispersed CNF–CMC samples were investigated by field emission scanning electron microscopy, viscosity measurement, and tensile test, respectively. The water-redispersed CNFs preserved the original properties of never dried CNFs. This new method will facilitate the production, transportation and storage, and large-scale industrial applications of CNFs.

  • 41.
    Caraballo, Rémi
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Dynamic Sulfur Chemistry: Screening, Evaluation and Catalysis2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with the design, formation and evaluation of dynamic systems constructed by means of sulfur-containing reversible reactions, in organic and aqueous media and under mild conditions.

    In a first part, the synthesis of thioglycoside derivatives, constituting the biologically relevant starting components of the dynamic systems, is described. In addition, the pD-profile of the mutarotation process in aqueous media for a series of 1-thioaldoses is reported and revealed an astonishing beta-anomeric preference for all the carbohydrate analogs under acidic or neutral conditions.

    In a second part, the phosphine-catalyzed or -mediated disulfide metathesis for dynamic system generation in organic or aqueous media is presented, respectively. The direct in situ 1H STD-NMR resolution of a dynamic carbohydrate system in the presence of a target protein (Concanavalin A) proved the suitability and compatibility of such disulfide metathesis protocols for the discovery of biologically relevant ligands.

    In a third part, hemithioacetal formation is demonstrated as a new and efficient reversible reaction for the spontaneous generation of a dynamic system, despite a virtual character of the component associations in basic aqueous media. The direct in situ 1H STD-NMR identification of the best dynamic beta-galactosidase inhibitors from the dynamic HTA system was performed and the results were confirmed by inhibition studies. Thus, the HTA product formed from the reaction between 1-thiogalactopyranose and a pyridine carboxaldehyde derivative provided the best dynamic inhibitor.

    In a fourth and final part, a dynamic drug design strategy, where the best inhibitors from the aforementioned dynamic HTA system were used as model for the design of non-dynamic (or “static”) beta-galactosidase inhibitors, is depicted. Inhibition studies disclosed potent leads among the set of ligands.

  • 42.
    Cassimjee, Karim Engelmark
    et al.
    KTH, School of Biotechnology (BIO), Biochemistry.
    Humble, Maria Svedendahl
    KTH, School of Biotechnology (BIO), Biochemistry.
    Land, Henrik
    KTH, School of Biotechnology (BIO), Biochemistry.
    Abedi, Vahak
    Berglund, Per
    KTH, School of Biotechnology (BIO), Biochemistry.
    Chromobacterium violaceum omega-transaminase variant Trp60Cys shows increased specificity for (S)-1-phenylethylamine and 4 '-substituted acetophenones, and follows Swain-Lupton parameterisation2012In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 10, no 28, p. 5466-5470Article in journal (Refereed)
    Abstract [en]

    For biocatalytic production of pharmaceutically important chiral amines the.-transaminase enzymes have proven useful. Engineering of these enzymes has to some extent been accomplished by rational design, but mostly by directed evolution. By use of a homology model a key point mutation in Chromobacterium violaceum omega-transaminase was found upon comparison with engineered variants from homologous enzymes. The variant Trp60Cys gave increased specificity for (S)-1-phenylethylamine (29-fold) and 4'-substituted acetophenones (similar to 5-fold). To further study the effect of the mutation the reaction rates were Swain-Lupton parameterised. On comparison with the wild type, reactions of the variant showed increased resonance dependence; this observation together with changed pH optimum and cofactor dependence suggests an altered reaction mechanism.

  • 43.
    Chen, Shan
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology. Hainan University, China.
    Liu, Fuyan
    Zhang, Kuan
    Huang, Hansheng
    Wang, Huani
    Zhou, Jiaying
    Zhang, Jing
    Gong, Yiwei
    Zhang, Dela
    Chen, Yiping
    Lin, Chang
    Wang, Bo
    An efficient enzymatic aminolysis for kinetic resolution of aromatic alpha-hydroxyl acid in non-aqueous media2016In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 57, no 48, p. 5312-5314Article in journal (Refereed)
    Abstract [en]

    A new and highly efficient enzymatic aminolysis approach for kinetic resolution of aromatic a-hydroxy acid in non-aqueous media has been developed. The corresponding alpha-hydroxyl acid ester was employed as the substrate, and commercially available Candida antarctica lipase B is used as the biocatalyst, anhydrous ammonia is the resolving agent. Reactions can be proceeded smoothly in organic solvent at ambient temperatures. High concentration of substrate is allowed due to the application of organic media and the products are obtained in yields of up to 49% with ee values of up to 99%, and with E value of >300, representing an appealing and promising protocol for large-scale preparations.

  • 44. Chen, Shao
    et al.
    Yuxin, Pei
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhichao, Pei
    Regioselective Acylation of 2 '- or 3 '-Hydroxyl Group in Salicin: Hemisynthesis of Acylated Salicins2014In: Chemical Research in Chinese Universities, ISSN 1005-9040, E-ISSN 2210-3171, Vol. 30, no 5, p. 774-777Article in journal (Refereed)
    Abstract [en]

    Salicin-based phenolic glycosides(PGs) are important defensive substances against herbivore feeding and have good bioactivities. In this work, a novel approach for the synthesis of salicin-based PGs has been developed, by which PGs of 2'-O-acetylsalicin(5a), 3'-O-acetylsalicin(5b) and 3'-O-benzoylsalicin(5d) were hemisynthesized. The effects of acylation reagent, solvent and temperature on the regioselective acylation of 2'- or 3'-hydroxyl groups of salicin mediated by dibutyltin oxide were investigated. The optimal conditions under which the best regioselectivity reached for 5a-5d were discovered, respectively. Moreover, a tentative tin-oxygen coordination mechanism was put forward to explain the different regioselectivities shown under different conditions.

  • 45. Cheng, Ming
    et al.
    Yang, Xichuan
    Li, Shifeng
    Wang, Xiuna
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Efficient dye-sensitized solar cells based on an iodine-free electrolyte using L-cysteine/L-cystine as a redox couple2012In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 5, no 4, p. 6290-6293Article in journal (Refereed)
    Abstract [en]

    A new iodine-free electrolyte based on amino acids L-cysteine/L-cystine as a redox couple has been designed and synthesized. DSSCs fabricated with the conventional I-/I-3(-) redox couple gave efficiencies of 8.1% and 6.3% under optimized experimental conditions based on ruthenium dye, N719, and metal-free organic dye, TH202, respectively. Based on the same dyes, the DSSCs employing the new L-cysteine/L-cystine redox couple showed comparable efficiencies of 7.7% and 5.6%, respectively. However, higher incident-photon-to-electron (IPCE) conversion efficiencies and larger J(sc) values were found for devices with the L-cysteine/L-cystine redox couple than with I-/I-3(-). From an electrochemical impedance spectroscopic study, we found that the charge recombination between the conduction band electrons in the TiO2 film and the electrolyte containing the L-cysteine/L-cystine redox couple is restrained.

  • 46.
    Cong, Jiayan
    et al.
    Dalian Univ Technol, Dalian, Peoples R China.
    Yang, Xichuan
    Dalian Univ Technol, Dalian, Peoples R China.
    Liu, Jing
    Dalian Univ Technol, Dalian, Peoples R China.
    Zhao, Jinxia
    Dalian Univ Technol, Dalian, Peoples R China.
    Hao, Yan
    Dalian Univ Technol, Dalian, Peoples R China.
    Wang, Yu
    Dalian Univ Technol, Dalian, Peoples R China.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Nitro group as a new anchoring group for organic dyes in dye-sensitized solar cells2012In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 48, no 53, p. 6663-6665Article in journal (Refereed)
    Abstract [en]

    An organic dye JY1 bearing a nitro group was designed, synthesized and applied in DSCs. An unusual colour change was observed when the voltage applied to the device was reversed which was accompanied by a five-fold increase in the cell efficiency. We propose that applying a bias enabled the attachment of nitro groups to the TiO2 surface.

  • 47. Córdova, Armando
    et al.
    Berglund, Per
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Anderson, Mattias
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Afewerki, Samson
    Efficient Synthesis Of Amines And Amides From Alcohols And Aldehydes By Using Cascade Catalysis2015Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention relates generally to an eco-friendly methodology for the conversion of alcohols and aldehydes to amines and amides using an integrated enzyme cascade system with metal-and organocatalysis. More specifically, the present invention relates to synthesis of capsaicinoids starting from vanillin alcohol and using a combination of an enzyme cascade system and catalysts. Furthermore, the method also relates to synthesis of capsaicinoids derivatives starting from vanillin alcohol derivatives and using a combination of an enzyme cascade system and catalysts.

  • 48.
    Daniel, Quentin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Water oxidation: From Molecular Systems to Functional Devices2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The production of hydrogen gas, through the process of water splitting,is one of the most promising concepts for the production of clean andrenewable fuel.The introduction of this thesis provides a brief overview of fossil fuelsand the need for an energy transition towards clean and renewable energy.Hydrogen gas is presented as a possible candidate fuel with its productionthrough artificial photosynthesis, being described. However, the highlykinetically demanding key reaction of the process – the water oxidationreaction – requires the use of a catalyst. Hence, a short presentation of differentmolecular water oxidation catalysts previously synthesized is also provided.The second part of the thesis focuses on ruthenium-based molecularcatalysis for water oxidation. Firstly, the design and the catalytic performancefor a new series of catalysts are presented. Secondly, a further study onelectron paramagnetic resonance of a catalyst shows the coordination of awater molecule to a ruthenium centre to generate a 7-coordinated complex atRuIII state. Finally, in an electrochemical study, coupled with nuclear magneticresonance analysis, mass spectrometry and X-ray diffraction spectroscopy, wedemonstrate the ability of a complex to perform an in situ dimerization of twounits in order to generate an active catalyst.The final part of this thesis focuses on immobilisation of first rowtransition metal catalysts on the surface of electrodes for electrochemical wateroxidation. Initially, a copper complex was designed and anchored on a goldsurface electrode. Water oxidation performance was studied byelectrochemistry, while deactivation of the electrode was investigated throughX-ray photoelectron spectroscopy, revealing the loss of the copper complexfrom the electrode during the reaction. Finally, we re-investigated cobaltporphyrin complexes on the surface of the electrode. Against the backgroundof previous report, we show that the decomposition of cobalt porphyrin intocobalt oxide adsorbed on the surface is responsible for the catalytic activity.This result is discussed with regard to the detection limit of various spectroscopic methods.

  • 49.
    Daniel, Quentin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Ambre, Ram
    Wang, Lei
    Zhang, Peili
    Chen, Hong
    Zhang, Biaobiao
    Li, Fusheng
    Fan, Ke
    Sun, Licheng
    Electrochemical water oxidation by Copper peptidecomplexes: molecular catalysts on gold electrode surfaceArticle in journal (Refereed)
  • 50.
    Daniel, Quentin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Duan, Lele
    Chen, Hong
    Ambre, Ram
    Zhang, Biaobiao
    Li, Fusheng
    Sun, Licheng
    Water oxidation initiated by in-situ dimerization of theRu(pdc) catalystArticle in journal (Refereed)
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