miun.sePublications
Change search
Refine search result
1234567 1 - 50 of 432
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Development of catalytic enantioselective C-C bond-forming and cascade transformations by merging homogeneous or heterogeneous transition metal catalysis with asymmetric aminocatalysis2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Chiral molecules play a central role in our daily life and in nature, for instance the different enantiomers or diastereomers of a chiral molecule may show completely different biological activity. For this reason, it is a vital goal for synthetic chemists to design selective and efficient methodologies that allow the synthesis of the desired enantiomer. In this context, it is highly important that the concept of green chemistry is considered while designing new approaches that eventually will provide more environmental and sustainable chemical synthesis.The aim of this thesis is to develop the concept of combining transition metal catalysis and aminocatalysis in one process (dual catalysis). This strategy would give access to powerful tools to promote reactions that were not successful with either transition metal catalyst or the organocatalyst alone. The protocols presented in this thesis based on organocatalytic transformations via enamine or iminium intermediates or both, in combination with transition metal catalysis, describes new enantioselective organocatalytic procedures that afford valuable compounds with high chemo- and enantioselectivity from inexpensive commercial available starting materials. In paper I, we present a successful example of dual catalysis: the combination of transition metal activation of an electrophile and aminocatalyst activation of a nucleophile via enamine intermediate. In paper II, the opposite scenario is presented, here the transition metal activates the nucleophile and the aminocatalyst activates the electrophile via an iminium intermediate. In paper III,we present a domino Michael/carbocyclisation reaction that is catalysed by a chiral amine (via iminium/enamine activation) in combination with a transition metal catalysts activation of an electrophile. In paper IV, the concept of dual catalysis was further extended and applied for the highly enantioselective synthesis of valuable structural scaffolds, namely poly-substituted spirocyclic oxindoles. Finally, in paper V the concept of dual catalysis was expanded, by investigating more challenging and environmentally benign processes, such as the successful combination of a heterogeneous palladium and amine catalysts for the highly enantioselective synthesis of functionalised cyclopentenes, containing an all carbonquaternary stereocenter, dihydrofurans and dihydropyrrolidines.

  • 2.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Direct regiospecific and highly enantioselective intermolecular a-allylic alkylation of aldehydes by combination of transition metal and chiral amine catalysts2012Conference paper (Refereed)
    Abstract [en]

    The direct intermolecular regiospecific and highly enantioselective a-allylic alkylation of linear aldehydes by combination of achiral bench stable Pd(0) complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific a-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 er). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals and 2-alkyl-butane-1,4-diols.

  • 3.
    Afewerki, Samson
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Breistein, Palle
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Pirttilä, Kristian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Deiana, Luca
    Univ Stockholm, Arrhenius Lab, Dept Organ Chem, S-10691 Stockholm, Sweden.
    Dziedzic, Pawel
    Univ Stockholm, Arrhenius Lab, Dept Organ Chem, S-10691 Stockholm, Sweden.
    Ibrahem, Ismail
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Catalytic Enantioselective beta-Alkylation of alpha,beta-Unsaturated Aldehydes by Combination of Transition-Metal- and Aminocatalysis: Total Synthesis of Bisabolane Sesquiterpenes2011In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 17, no 32, 8784-8788 p.Article in journal (Refereed)
    Abstract [en]

    Branching out! The first co-catalytic enantioselective (up to 98:2 e.r.) β-alkylation of α,β-unsaturated aldehydes by combination of simple chiral amine and copper catalysts provides β-branched aldehydes in a one-pot protocol (see scheme). The methodology was applied to the short total syntheses of bisabolane sesquiterpenes (S)-(+)-curcumene, (E)-(S)-(+)-3- dehydrocurcumene and (S)-(+)-tumerone. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 4.
    Afewerki, Samson
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Arrhenius Lab, Berzelii Ctr EXSELENT, Stockholm.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Arrhenius Lab, Berzelii Ctr EXSELENT, Stockholm.
    Combinations of Aminocatalysts and Metal Catalysts: A Powerful Cooperative Approach in Selective Organic Synthesis2016In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 116, no 22, 13512-13570 p.Article, review/survey (Refereed)
    Abstract [en]

    The cooperation and interplay between organic and metal catalyst Arninocatalysis systems is of utmost importance in nature and chemical synthesis. Here innovative and selective cooperative catalyst systems can be designed by combining two catalysts that complement rather than inhibit one another. This refined strategy can permit chemical transformations unmanageable by either of the catalysts alone. This review summarizes innovations and developments in selective organic synthesis that have used cooperative dual catalysis by combining simple aminocatalysts with metal catalysts. Considerable efforts have been devoted to this fruitful field. This emerging area employs the different activation modes of amine and metal catalysts as a platform to address challenging reactions. Here, aminocatalysis (e.g., enamine activation catalysis, iminium activation catalysis, single occupied molecular orbital (SOMO) activation catalysis, and photoredox activation catalysis) is employed to activate unreactive carbonyl substrates. The transition metal catalyst complements by activating a variety of substrates through a range of interactions (e.g., electrophilic pi-allyl complex formation, Lewis acid activation, allenylidene complex formation, photoredox activation, C-H activation, etc.), and thereby novel concepts within catalysis are created. The inclusion of heterogeneous catalysis strategies allows for "green" chemistry development, catalyst recyclability, and the more eco-friendly synthesis of valuable compounds.

  • 5.
    Afewerki, Samson
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Guangning, Ma
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Ibrahem, Ismail
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Highly enantioselective organo/metal cooperative catalysis for construction of spirocyclopentaneoxindoles2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248, 173-ORGNArticle in journal (Other academic)
  • 6.
    Afewerki, Samson
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Ibrahem, Ismail
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Rydfjord, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Breistein, Palle
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Direct Regiospecific and Highly Enantioselective Intermolecular α-Allylic Alkylation of Aldehydes By Combination of Transition Metal and amine Catalysts2012In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 18, no 10, 2972-2977 p.Article in journal (Refereed)
    Abstract [en]

    The first direct intermolecular regiospecific and highly enantioselective α-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd 0 complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecificα-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 e.r.; e.r.=enantiomeric ratio). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals, 2-alkyl-butane-1,4-diols, and amines. The concise co-catalytic asymmetric total syntheses of biologically active natural products (e.g., Arundic acid) are disclosed. Go organic! Directintermolecular regiospecific and highly enantioselective α-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd 0complexes and simple chiral amines as co-catalysts is disclosed (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 7.
    Afewerki, Samson
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Berzelii Ctr EXSELENT, SE-10691 Stockholm, Sweden.
    Ma, Guangning
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Ibrahem, Ismail
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Liu, Leifeng
    Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden .
    Sun, Junliang
    Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden .
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden .
    Highly Enantioselective Control of Dynamic Cascade Transformations by Dual Catalysis: Asymmetric Synthesis of Polysubstituted Spirocyclic Oxindoles2015In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 5, no 2, 1266-1272 p.Article in journal (Refereed)
    Abstract [en]

    The highly enantioselective (up to >99.5:0.5 er) synthesis of polysubstituted spirocyclic oxindoles with four new contiguous stereocenters, including the spiro all-carbon quaternary center, is disclosed. It is accomplished by the highly stereoselective control of a dynamic conjugate/intramolecular allylic alkylation relay sequence based on the synergistic cooperation of metal and chiral amine catalysts in which the careful selection of organic Nand, metal complex, and chiral amine is essential. The intermolecular C-C bond-forming step occurred only when both the metal and chiral amine catalysts were present.

  • 8. Ahonen-Jonnarth, U.
    et al.
    Van Hees, P.A.W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Finlay, R.D.
    Organic acids produced by mycorrhizal Pinus sylvestris exposed to elevated aluminium and heavy metals concentrations2000In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 146, no 3, 557-567 p.Article in journal (Refereed)
    Abstract [en]

    A cultivation method was developed to enable exposure of ectomycorrhizal plants with intact extramatrical mycelium to solutions containing different concentrations of aluminium or heavy metals. Pinus sylvestris seedlings colonized by Suillus variegatus (two isolates), Rhizopogon roseolus or Paxillus involutus (two isolates) were used. Seedlings were transferred to Petri dishes containing glass beads and exposed to elevated concentrations of Al, Cd, Cu, or Ni in two ways: immediately following transfer; and after allowing mycorrhizal seedlings to develop an extraradical mycelium that colonized the interface between the upper surface of the beads and the metal-containing solution. Production of organic acids in mycorrhizal and non-mycorrhizal systems was measured by withdrawing samples from the solution and analyzing by HPLC. In most experiments, levels of oxalic acid were significantly higher in mycorrhizal treatments than in non-mycorrhizal controls. The measured levels of organic acids were variable, but the results obtained suggest that production of oxalic acid is stimulated by exposure to elevated Al in mycorrhizal seedlings colonized by S. variegatus and R. roseolus. Elevated Al concentrations also increased oxalic acid production by non-mycorrhizal seedlings significantly in two of four Al experiments performed, but the measured concentrations were significantly lower than in corresponding mycorrhizal treatments in both cases. Malonic acid was found in the culture solution of non-mycorrhizal had P. involutus-colonized seedlings, but only trace amounts were found in S. variegatus or R. roseolus-infected seedlings. Citric, shikimic, lactic, acetic, propionic, fumaric, formic, iso-butyric and butyric acid were found in variable concentrations. Production of oxalic acid by seedlings ColoniZed by S. variegatus BL or P. involutus was not stimulated by exposure to 0.44 μM Cd or 17 μM Ni. Exposure to 0.157 mM CU in two separate experiments using P. involutus 87.017 and two strains of S. variegatus (BL and 159) appeared to stimulate production of oxalic acid irrespective of mycorrhizal status or species.

  • 9. Alison, M Lee-Manion
    et al.
    Price, Ruth K
    Strain, J J
    Dimberg, Lena H
    Sunnerheim, Kerstin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Welch, Robert W
    In Vitro Antioxidant Activity and Antigenotoxic Effects of Avenanthramides and Related Compounds2009In: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 57, no 22, 10619-10624 p.Article in journal (Refereed)
    Abstract [en]

    Avenanthramides are substituted N-cinnamoylanthranilic acids, with hydroxycinnamic acid and anthranilic acid moieties. These alkaloid phenols, which are unique to oats, may confer health benefits via antioxidant or other mechanisms. Synthetic avenanthramides, hydroxycinnamic acids, Tranilast, and ascorbic acid were evaluated for antioxidant activity using two assays, DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant potential), and for antigenotoxicity using the Comet assay with stressed human adenocarcinoma colon cells. Of all the compounds tested, N-(3′,4′-dihydroxy-(E)-cinnamoyl)-5-hydroxyanthranilic acid (2c), an abundant oat avenanthramide, generally had the highest activity in all three assays. The drug Tranilast showed antigenotoxic effects, but not antioxidant activity, suggesting that antigenotoxicity is not dependent on antioxidant effects. Overall, results show that avenanthramides exert antioxidant and antigenotoxic activities that are comparable to those of ascorbic acid and which have the potential to exert beneficial physiological effects.

     

  • 10. Almesåker, Ann
    et al.
    Bourne, Susan A.
    Ramon, Gaëlle
    Scott, Janet. L.
    Strauss, Chris. R.
    Coordination chemistry of N,N,4-tris(pyridin-2-ylmethyl)aniline, a novel flexible, multimodal ligand2007In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 9, no 11, 997-1010 p.Article in journal (Refereed)
    Abstract [en]

    The ligand N, N, 4-tris(pyridin-2-ylmethyl) aniline was synthethised using a multicomponent reaction, which is applicable to the synthesis of a large library of similarly structured ligands. A range of metal complexes with copper, cobalt and manganese ions were crystallised as discrete complexes, dimers and 1D coordination polymers, illustrating the flexibility of the ligand in the preparation of diverse structures. While coordination about the metal centres is similar in each group with a common metal ion, the different structures represent materials with varying structural and packing topologies. Varying the counterions and crystallisation solvents gives rise to discrete complexes, dimers and a porous 1D coordination polymer. In the latter case, solvent molecules entrapped in the channels are replaceable and guest exchange is detected by single crystal and powder diffraction indicating interesting storage possibilities.

  • 11.
    Almesåker, Ann
    et al.
    School of Chemistry and Centre for Green Chemistry, Monash University, Victoria 3800, Australia.
    Gamez, P.
    Reedijk, J.
    Scott, J. L.
    Spiccia, L.
    Teat, S. J.
    Stabilisation of a very short Cu-F bond within the protected cavity of a copper(II) compound from a tris(2-aminoethyl)amine derivative2009In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 7, no 21, 4077-4080 p.Article in journal (Refereed)
    Abstract [en]

    The copper(II) coordination compound of an N-functionalised derivative of tris(2-aminoethyl)amine forms a cavity that is an excellent fluoride ion host, generating a Cu-F entity with a very short distance (182 pm) and characterised by a fluoride ion devoid of any additional intermolecular interactions.

  • 12.
    Almesåker, Ann
    et al.
    School of Chemistry and ARC Special Research Centre for Green Chemistry, Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
    Scott, J. L.
    Spiccia, L.
    Strauss, C. R.
    One-pot synthesis of tripodal tris(2-aminoethyl)amine derivatives from seven molecular components2009In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 50, no 16, 1847-1850 p.Article in journal (Refereed)
    Abstract [en]

    Complex tripodal tris(2-aminoethyl)amine (tren)-based ligands have been prepared in a single-pot reaction of tren with 3 equiv each of cyclohexenone and a benzaldehyde derivative (i.e., from seven components and three molecular types). The highest yield of product was obtained for p-nitrobenzaldehyde, the most electrophilic aldehyde used. (C) 2009 Published by Elsevier Ltd.

  • 13.
    Alves, L.
    et al.
    University of Coimbra, Department of Chemistry, Coimbra, Portugal .
    Medronho, B.
    Faculty of Sciences and Technology, Centre for Mediterranean Bioresources and Food, University of Algarve, Ed. 8, Campus de Gambelas, Faro, Portugal .
    Antunes, F. E.
    University of Coimbra, Department of Chemistry, Coimbra, Portugal .
    Fernández-García, M. P.
    IFIMUP and in - Institute of Nanoscience and Nanotechnology, Department of Physics and Astronomy, Faculty of Science, University of Porto, Porto, Portugal .
    Ventura, J.
    IFIMUP and in - Institute of Nanoscience and Nanotechnology, Department of Physics and Astronomy, Faculty of Science, University of Porto, Porto, Portugal .
    Araújo, J. P.
    IFIMUP and in - Institute of Nanoscience and Nanotechnology, Department of Physics and Astronomy, Faculty of Science, University of Porto, Porto, Portugal .
    Romano, A.
    Faculty of Sciences and Technology, Centre for Mediterranean Bioresources and Food, University of Algarve, Ed. 8, Campus de Gambelas, Faro, Portugal .
    Lindman, Björn
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering. Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore .
    Unusual extraction and characterization of nanocrystalline cellulose from cellulose derivatives2015In: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 210, 106-112 p.Article in journal (Refereed)
    Abstract [en]

    Unlike many nanomaterials, nanocrystalline cellulose (CNC) is not synthesized from molecular or atomic components but rather extracted from naturally occurring cellulose. Undoubtedly, the exploitation of CNCs will become a bridge between nanoscience and natural resource products, which could play a major role in reviving the forest industry. In this work, CNC was successfully extracted from unusual sources, hydroxypropyl methylcellulose (HPMC) and carboxymethylcellulose (CMC). The extracted crystallites were purified and further characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and dynamic light scattering (DLS). The average size of the CNCs extracted from HPMC and CMC was found to be less (and with lower zeta potential) than the ones extracted from microcrystalline cellulose (MCC). On the other hand, FTIR and XRD revealed that native HPMC and CMC are unexpectedly highly crystalline and hence can be used as a source for CNCs. © 2014 Elsevier B.V.All rights reserved.

  • 14. Anderbrant, O
    et al.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Pheromone mating disruption of the pine sawfly Neodiprion sertifer.: Is the size of the area important?2002In: IOBC/WPRS Bulletin, ISSN 1027-3115, Vol. 25, no 9, 111-116 p.Article in journal (Other scientific)
    Abstract [en]

    The success of mating disruption in relation to the area treated is discussed

  • 15. Anderbrant, O
    et al.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Löfqvist, J
    Towards use of Pine Sawfly Pheromones in Forest Protection: Evalution of a Behavioural Antagonist for Mationg Disruption of Neodiprion sertifer1998In: Population Dynamics, Impacts and Integrated Management of Forest Defoliating Insects, 1998, 53-63 p.Conference paper (Refereed)
  • 16. Anderbrant, O
    et al.
    Löfqvist, E
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Development of mating disruption for control of pine sawfly populations1995In: Entomologia Experimentalis et Applicata, ISSN 0013-8703, Vol. 74, no 1, 83-90 p.Article in journal (Refereed)
  • 17. Anderbrant, O
    et al.
    Löfqvist, J
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Baldassari, N
    Baronio, P
    Kolmakova, G
    Lyons, B
    Naito, T
    Odinokov, V
    Simandl, J
    Suptashvili, A
    Tai, A
    Tourianov, R
    Geographic Variation in the Field Response of Male Pine Sawflies Neodiprion sertifer, to Different Pheromone Stereoisomers and Esters2000In: Entomologia Experimentalis et Applicata, ISSN 0013-8703, E-ISSN 1570-7458, Vol. 95, no 3, 229-239 p.Article in journal (Refereed)
  • 18. Anderbrant, O
    et al.
    Löfqvist, J
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wassgren, A.-B.
    Bergström, G
    Bengtsson, M
    Magnusson, G
    Field Response Of The Pine Sawfly Neodiprion-Sertifer To The Pheromone (2s,3s,7s)-Diprionyl Acetate And Its Stereoisomers1992In: Entomologia Experimentalis et Applicata, ISSN 0013-8703, Vol. 62, no 2, 169-181 p.Article in journal (Refereed)
  • 19. Anderbrant, Olle
    et al.
    Lyons, D. Barry
    Bång, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Sex Pheromone of the Introduced Pine Sawfly, Diprion similis (Diprionidae), Revisited: No Activity of Earlier Reported SynergistsManuscript (preprint) (Other academic)
    Abstract [en]

    Extracts of Diprion similis females were found to contain about 15 ng of the sex pheromone precursor 3,7-dimethylpentadecan-2-ol per female. When analysing the extracts after derivatisation with (2S)-2-acetoxypropionyl chloride, we found that the major stereoisomer in the extract was (2S,3R,7R)-3,7-dimethylpentadecan-2-ol. Also other stereoisomers of 3,7-dimethylpentadecan-2-ol were identified in the extract namely, 1% of (2R,3S,7S) , 0.3% (2R,3R,7R) and 0.4% of (2R,3R,7S). An unknown fifth substance showed an identical spectrum to 3,7-dimethylpentadecan-2-ol, both in SIM and full scan mode. In field tests in Ontario, Canada, the earlier identified main pheromone component, viz. the propanoate of (2S,3R,7R)-3,7-dimethylpentadecan-2-ol, was tested alone and in combination with other stereoisomers, earlier reported to be synergistic. In none of the tests were any synergistic effects detected and the threo four-isomer blend was as attractive as the pure main compound. Thus, one of the few examples of a diprionid sawfly using more than one substance in its sex pheromone could not be confirmed. The results also suggest that monitoring programs can use the more easily synthesized threo-blend without losing efficiency.

  • 20. Anderbrant, Olle
    et al.
    Löfqvist, J
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Mating disruption of the Pine Sawfly Neodiprion sertifer (Hymenoptera: Dipionidae): Effects on Pheromone Trap Catch, Sex Ratio, Population Density and Tree Damage1995In: Behavior, population dynamics, and control of forest insects: Proceedings of the International Union of Forestry Research Organizations Joint conference, February 1994, 1995, 415-427 p.Conference paper (Refereed)
  • 21.
    Anderbrant, Olle
    et al.
    Department of Biology, Lund University.
    Löfqvist, Jan
    Department of Plant Protection Science, Swedish University of Agricultural Sciences, Alnarp.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Bång, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Tai, Akira
    Faculty of Science, Himeji Institute of Technology, Kanaji Kamigor, Japan.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Field Response of Male Pine Sawflies, Neodiprion sertifer (Diprionidae), to Sex Pheromone Analogs in Japan and Sweden2010In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 36, no 9, 969-977 p.Article in journal (Refereed)
    Abstract [en]

    The pine sawfly Neodiprion sertifer (Geoffroy) uses the acetate or propionate of (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) as pheromone components, with the (2S,3R,7R)-isomer being antagonistic, synergistic, or inactive according to the population tested. In this study, we tested the attraction of males to the acetates of three analogs of diprionol, each missing one methyl group, viz. (2S,7S)-7-methyl-2-pentadecanol, (2S,6S)-2,6-dimethyl-1-tetradecanol, and (2S,3S)-3-methyl-2-pentadecanol. None of the analogs alone, or in combination with diprionol acetate, was attractive in Sweden, even at 100 times the amount of diprionol acetate attractive to N. sertifer. In Japan, the acetate of (2S,3S)-3-methyl-2-pentadecanol attracted males when tested in amounts 10–20 times higher than the acetate pheromone component. The acetate esters of the (2S,3R)-analog and the (2S,3R,7R)-isomer of diprionol also were tested in combination with the pheromone compound (acetate ester). Both compounds caused an almost total trap-catch reduction in Sweden, whereas in Japan they appear to have relatively little effect on trap capture when added to diprionol acetate. Butyrate and iso-butyrate esters of diprionol were unattractive to N. sertifer in Sweden. In summary, there exists geographic variation in N. sertifer in responses to both diprionyl acetate and some of its analogs.

  • 22. Anderbrant, Olle
    et al.
    Östrand, Fredrik
    Bergström, Gunnar
    Wassgren, Ann-Britt
    Auger-Rozenberg, Marie-Anne
    Geri, Claude
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Release of sex pheromone and its precursors in the pine sawfly Diprion pini (Hym., Diprionidae)2005In: Chemoecology, ISSN 0937-7409, E-ISSN 1423-0445, Vol. 15, no 3, 147-151 p.Article in journal (Refereed)
    Abstract [en]

    The first identification of a sex pheromone of a pine sawfly (Hymenoptera, Diprionidae) dates back almost thirty years. Since then, female-produced pheromones of over twenty diprionid species have been investigated by solvent extraction followed by separation and identification. However, no study has shown what the females actually release. Collection of airborne compounds using absorbtion on charcoal filter as well as solid phase microextraction (SPME) followed by analysis employing gas chromatography combined with mass spectrometry (GC-MS), revealed an unusual system in Diprion pini, in which the pheromone precursor alcohol, 3,7-dimethyl-2-tridecanol, is released together with acetic, propionic, butyric and isobutyric acids. The corresponding acetate, propionate and butyrate esters of 3,7-dimethyl-2-tridecanol were also found in the samples. All esters were electrophysiologically active, and the propionate and isobutyrate were attractive in trapping experiments. Based on these and earlier reported results, it seems that at least in part of its range, the pheromone response of D. pini is not very specific with regard to the functional group, as long as this is an ester.

     

     

  • 23.
    Anderson, Mattias
    et al.
    AlbaNova Univ Ctr, KTH Royal Inst Technol, Sch Biotechnol, Div Ind Biotechnol, SE-10691 Stockholm, Sweden.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Berglund, Per
    AlbaNova Univ Ctr, KTH Royal Inst Technol, Sch Biotechnol, Div Ind Biotechnol, SE-10691 Stockholm, Sweden.
    Cordova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Stockholm Univ, Dept Organ Chem, Arrhenius Lab, SE-10691 Stockholm, Sweden.
    Total Synthesis of Capsaicin Analogues from Lignin-Derived Compounds by Combined Heterogeneous Metal, Organocatalytic and Enzymatic Cascades in One Pot2014In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 356, no 9, 2113-2118 p.Article in journal (Refereed)
    Abstract [en]

    The total synthesis of capsaicin analogues was performed in one pot, starting from compounds that can be derived from lignin. Heterogeneous palladium nanoparticles were used to oxidise alcohols to aldehydes, which were further converted to amines by an enzyme cascade system, including an amine transaminase. It was shown that the palladium catalyst and the enzyme cascade system could be successfully combined in the same pot for conversion of alcohols to amines without any purification of intermediates. The intermediate vanillyl-amine, prepared with the enzyme cascade system, could be further converted to capsaicin analogues without any purification using either fatty acids and a lipase, or Schotten-Baumann conditions, in the same pot. An aldol compound (a simple lignin model) could also be used as starting material for the synthesis of capsaicin analogues. Using l-alanine as organocatalyst, vanillin could be obtained by a retro-aldol reaction. This could be combined with the enzyme cascade system to convert the aldol compound to vanillylamine in a one-step one-pot reaction.

  • 24. Andersson, Fredrik
    1. Asymmetric aldol and alkylation reactions using pyrrolidine-based chiral auxiliaries 2. Syntheses of pine sawfly pheromone precursors and structurally related compounds2002Licentiate thesis, comprehensive summary (Other academic)
  • 25.
    Andersson, Fredrik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Highly stereoselective alkylation of (S)-proline-based chiral auxiliaries2004In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 15, no 16, 2539-2545 p.Article in journal (Refereed)
    Abstract [en]

    Alkylation of the enolates of the propanoylamides of two chiral auxiliaries (S)-(-)-2-(pyrrolidin-2-yl)propan-2-ol 1a and (S)-(-)-2-(2-methoxypropan-2-yl)pyrrolidine 1b, derived from (S)-proline, with benzyl bromide and n-butyl iodide has been studied. The auxiliaries 1a and 1b induced opposite selectivity that is (R)- and (S)-configuration, respectively, at the newly created stereogenic centre. The diastereoselectivities and conversion yields in these alkylations were moderate to excellent. When Cp2ZrCl2 was used as an enolate coordinating agent, benzylation of propanoylated 1b gave an excellent diastereomeric ratio of 99:1. The benzylated diastereomeric products from either propanoylated 1a or 1b were easily separated by liquid chromatography.

  • 26.
    Andersson, Fredrik
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Synthesis of two (S)-indoline-based chiral auxiliaries and their use in diastereoselective alkylation reactions2006In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 17, no 13, 1952-1957 p.Article in journal (Refereed)
    Abstract [en]

    Two chiral auxiliaries, 2-[(S)-indolin-2-yl]propan-2-ol 1a and (S)-2-(2-methoxypropan-2-yl)indoline 1b, were synthesised from enantiomerically pure (S)-indoline-2-carboxylic acid 3. High diastereoselectivities in alkylations of enolates of the propanoylamides derived from the two auxiliaries are presented. Surprisingly, both auxiliaries induced the same selectivity at the newly created stereogenic centre. The benzyl bromide and n-butyl iodide alkylation reactions showed diastereomeric ratios that were moderate (81:19) to very good (96:4) and with very good yields (86-98%). When LiCl was used as an enolate coordinating agent, in the benzylation of the enolate from propanoylated auxiliary 1a, a very high crude diastereomeric ratio was obtained (99.7:0.3).

  • 27.
    Andersson, K.
    et al.
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, SE-23053 Alnarp, Sweden.
    Bergman, K. -O
    IFM Biology, Conservation Ecology Group, Linköping University, SE-58183 Linköping, Sweden.
    Andersson, Fredrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Jansson, N.
    IFM Biology, Conservation Ecology Group, Linköping University, SE-58183 Linköping, Sweden.
    Burman, J.
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, SE-23053 Alnarp, Sweden.
    Winde, I.
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, SE-23053 Alnarp, Sweden.
    Larsson, M. C.
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, SE-23053 Alnarp, Sweden.
    Milberg, P.
    IFM Biology, Conservation Ecology Group, Linköping University, SE-58183 Linköping, Sweden.
    High-accuracy sampling of saproxylic diversity indicators at regional scales with pheromones: The case of Elater ferrugineus (Coleoptera, Elateridae)2014In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 171, 156-166 p.Article in journal (Refereed)
    Abstract [en]

    The rare beetle Elater ferrugineus was sampled at 47 sites in the county of Östergötland, Sweden by means of pheromone-baited traps to assess its value as an indicator species for hollow oak stands rich in rare saproxylic beetle species. In addition, Osmoderma eremita was also sampled with pheromone baits. These data were then compared against species survey data collected at the same sites by pitfall and window traps. Both species co-occur with many Red Listed saproxylic beetles, with E. ferrugineus being a somewhat better indicator for the rarest species. The conservation value of a site (measured as Red List points or number of Red Listed species) increased with the number of specimens of E. ferrugineus and O. eremita caught. Accuracy of sampling by means of pheromone trapping turned out to be radically different for the two model species. E. ferrugineus traps put out during July obtained full accuracy after only 6. days, whereas O. eremita traps needed to be out from early July to mid-August in order to obtain full accuracy with one trap per site. By using E. ferrugineus, or preferably both species, as indicator species, accuracy would increase and costs decrease for saproxylic biodiversity sampling, monitoring and identification of hotspots. © 2014 Elsevier Ltd.

  • 28.
    Barhoum, Ahmed
    et al.
    Vrije Universiteit Brussel (VUB), Belgium.
    Samyn, Pieter
    Hasselt University, Belgium.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dufresne, Alain
    Univ. Grenoble Alpes, France.
    Review of recent research on flexible multifunctional nanopapers2017In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 40, 15181-15205 p.Article in journal (Refereed)
    Abstract [en]

    Traditional paper and papermaking have struggled with a declining market during the last decades. However, the incorporation of nanotechnology in papermaking has brought possibilities to develop low-cost, biocompatible and flexible products with sophisticated functionalities. The functionality of nanopapers emerges from the intrinsic properties of the nanofibrous network, the additional loading of specific nanomaterials, or the additional deposition and patterning of thin films of nanomaterials on the paper surface. A successful development of functional nanopapers requires understanding in how the nanopaper matrix, nanomaterial fillers, coating pigments/inks, functional additives and manufacturing processes all interact to provide the intended functionality. This review addresses the emerging area of functional nanopapers. The review discusses flexible and multifunctional nanopapers, nanomaterials being used in nanopaper making, manufacturing techniques, and functional applications that provide new important possibilities to utilize papermaking technology. The interface where nanomaterials research meets traditional papermaking has important implications for food packaging, energy harvesting, and energy storage, flexible electronics, low-cost devices for medical diagnostics, and numerous other areas.

  • 29. Berg, S.
    et al.
    Jonsson, Anders
    Högskolan i Östersund.
    Analysis of airborne organic lead1984In: Biological effects of organolead compounds, Boca Raton, FL: CRC Press , 1984, 278- p.Chapter in book (Other academic)
  • 30. Berg, S.
    et al.
    Jonsson, Anders
    Högskolan i Östersund.
    Two-dimensional gas chromatography for determination of volatile compounds in ambient air1984In: HRC & CC, Journal of High Resolution Chromatography and Chromatography Communications, ISSN 0344-7138, Vol. 7, no 12, 687-695 p.Article in journal (Refereed)
  • 31. Bergelin, A.
    et al.
    van Hees, P. A. W.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wahlberg, O.
    Department of Chemistry, Royal Institute of Technology, .
    Lundström, Ulla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    The acid-base properties of high and low molecular weight organic acids in soil solutions of podzolic soils2000In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 94, no 2-4, 223-235 p.Article in journal (Refereed)
    Abstract [en]

    The acid properties of the organic acids and identified low molecular weight (LMW) organic acids in soil solutions of podzolic soils were determined using proton affinity spectra, based on EMF titration data, and Gran titrations. The proton affinity spectra showed apparent pKa values of 2.6, 4.1, 5.4 and 6.7 for the dissolved organic material. The LMW organic acids had similar pKa values. The average specific buffer capacity as determined by Gran titrations was 8.8±0.5 μmol H+/mg DOC. The specific buffer capacity for the identified low molecular acids was 40±2 μmol H+/mg DOC.

  • 32.
    Berglund, Per
    et al.
    Department of Biotechnology, Royal Institute of Technology, SE-100 44 Stockholm.
    Christiernin, M
    Department of Biotechnology, Royal Institute of Technology, SE-100 44 Stockholm.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Enantiorecognition of Chiral Acids by Candida rugosa Lipase: Two Substrate Binding Modes Evidenced in an Organic Medium2001In: Applied Biocatalysis in Speciality Chemicals and Pharmaceuticals, 2001, 263-273 p.Conference paper (Refereed)
    Abstract [en]

    We have identified the existence of different modes of binding the enantiomers of 2-methyl-branched carboxylic acids to a lipase active site by rational substrate engineering. Similar to hydrolysis, previously investigated, we have now evidence for differential binding modes in the Candida rugosa lipase-catalyzed esterifications in cyclohexane. The relevance of considering two different binding modes to understand lipase enantiorecognition is demonstrated by introducing bulky substituents on a chiral carboxylic acid which impose a different orientation of the substrate acyl chain in the active site of Candida rugosa lipase. With this substrate engineering approach based on molecular modeling it is thus possible to markedly alter the enantioselectivity of the lipase. Examples from hydrolysis and new results from esterifications in an organic solvent are presented and discussed.

  • 33. Berglund, Per
    et al.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Preparation of 2-, 3-, and 4-methylcarboxylic acids and the corresponding alcohols of high enantiopurity by lipase catalyzed esterification2001In: Enzymes in Nonaqueous Solvents: Methods and Protocols, Humana Press, 2001, 307-317 p.Chapter in book (Other academic)
  • 34.
    Berglund, Per
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmquist, M
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hult, K
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    2-Methylalkanoic Acids Resolved by Esterification Catalysed by Candida rugosa: Alcohol Chain Length and Enantioselectivity1993In: Tetrahedron: Asymmetry, ISSN 0957-4166, Vol. 4, no 8, 1869-1878 p.Article in journal (Refereed)
  • 35.
    Berglund, Per
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmquist, M
    Hult, K
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Alcohols as Enantioselective Inhibitors in a Lipase Catalysed Esterification of a Chiral Acyl Donor1995In: Biotechnology Letters, ISSN 0141-5492, Vol. 17, no 1, 55-60 p.Article in journal (Refereed)
  • 36. Bergström, G
    et al.
    Wassgren, A.-B.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hefetz, Abraham
    Simon, Dan
    Ohlsson, T
    Löfqvist, J
    Species specific, Two-Component, Volatile Signals in two Sympatric Ant-lion Species: Synclysis baetica and Acanthaclisis occitanica (Neuroptera, Myrmeleontidae1992In: Journal of Chemical Ecology, ISSN 0098-0331, Vol. 17, no 7, 1177-1188 p.Article in journal (Refereed)
  • 37. Bergström, Gunnar
    et al.
    Wassgren, A.-B.
    Anderbrant, O
    Fägerhag, Jonas
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Geri, C
    Auger, M. A.
    Varama, M
    Hansson, B. S.
    Löfqvist, J
    Sex pheromone of the pine sawfly Diprion pini (Hymenoptera: Diprionidae): Chemical identification, synthesis and biological activity1995In: Experientia, ISSN 0014-4754, Vol. 51, no 4, 370-380 p.Article in journal (Refereed)
  • 38. Bergström, Gunnar
    et al.
    Wassgren, Ann-Britt
    Anderbrant, Olle
    Ochieng, Samuel
    Östrand, Fredrik
    Hansson, Bill S.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sex Pheromone of the Pine Sawfly Microdiprion pallipes (Hymenoptera: Diprionidae)1998In: Naturwissenschaften, ISSN 0028-1042, Vol. 85, no 5, 244-248 p.Article in journal (Refereed)
  • 39. Bhupinderpal-Singh,
    et al.
    Nordgren, A
    Ottosson Löfvenius, Mikael
    Högberg, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Mellander, Per- Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Högberg, P
    Large-scale girdling of Scots pine boreal forest reveals controls and estimates of mycorrhizal root soil heterotrophic respiration2003In: Proceedings Third International Symposium on the Dynamics of Physiological Processes in Woody Roots. Perth, Western Australia 29 Sept – 3 Oct, 2003, 2003Conference paper (Other scientific)
  • 40. Bohman, B
    et al.
    Nordenhem, H
    Sunnerheim, Kerstin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Borg-Karlson, A-K
    Unelius, C R
    Structure-activity relationships of phenylpropanoids as antifeedants for the pine weevil Hylobius abietis2008In: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 34, no 3, 339-352 p.Article in journal (Refereed)
    Abstract [en]

    Ethyl cinnamate has been isolated from the bark of Pinus contorta in the search for antifeedants for the pine weevil, Hylobius abietis. Based on this lead compound, a number of structurally related compounds were synthesized and tested. The usability of the Topliss scheme, a flow diagram previously used in numerous structure-activity relationship (SAR) studies, was evaluated in an attempt to find the most potent antifeedants. The scheme was initially followed stepwise; subsequently, all compounds found in the scheme were compared. In total, 51 phenylpropanoids were tested and analyzed for SARs by using arguments from the field of medicinal chemistry (rational drug design). Individual Hansch parameters based on hydrophobicity, steric, and electronic properties were examined. The effects of position and numbers of substituents on the aromatic ring, the effects of conjugation in the molecules, and the effects of the properties of the parent alcohol part of the esters were also evaluated. It proved difficult to find strong SARs derived from single physicochemical descriptors, but our study led to numerous new, potent, phenylpropanoid antifeedants for the pine weevil. Among the most potent were methyl 3-phenylpropanoates monosubstituted with chloro, fluoro, or methyl groups and the 3,4-dichlorinated methyl 3-phenylpropanoate.

  • 41.
    Boija, Susanne
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    On metal ion chelates and conditional stability constant determination: Method development and selective ion flotation of chelating surfactants2014Licentiate thesis, comprehensive summary (Other academic)
  • 42.
    Boija, Susanne
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Almesåker, Ann
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Determination of conditional stability constants for some divalent transition metal ion-EDTA complexes by electrospray ionization mass spectrometry2014In: Journal of Mass Spectrometry, ISSN 1076-5174, E-ISSN 1096-9888, Vol. 49, no 7, 550-556 p.Article in journal (Refereed)
    Abstract [en]

    Conditional stability constants of coordination complexes comprising divalent transition metals, Cu2+, Ni2+, Zn2+, Co2+, and ethylenediaminetetraacetic acid (EDTA) were determined utilizing electrospray ionization mass spectrometry. The deviation of signal response of a reference complex was monitored at addition of a second metal ion. The conditional stability constant for the competing metal was then determined through solution equilibria equations. The method showed to be applicable to a system where Co2+ and Zn2+ competed for EDTA at pH 5. When Cu2+ and Ni2+ competed for EDTA, the equilibrium changed over time. This change was shown to be affected in rate and size by the type of organic solvent added. In this work, 30% of either methanol or acetonitrile was used. It was found that if calibration curves are prepared for both metal complexes in solution and the measurements are repeated with sufficient time space, any change in equilibrium of sample solutions will be discovered. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  • 43. Bratt, Katarina
    et al.
    Sunnerheim, Kerstin
    Bryngelsson, Susanne
    Fagerlund, Amelie
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engman, Lars
    Andersson, Rolf E
    Dimberg, Lena H
    Avenanthramides in Oats (Avena Sativa L.) and Structure-Activity Relationships2003In: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 51, no 3, 594-600 p.Article in journal (Refereed)
    Abstract [en]

    Eight avenanthramides, amides of anthranilic acid (1) and 5-hydroxyanthranilic acid (2), respectively, and the four cinnamic acids p-coumaric (p), caffeic (c), ferulic (f), and sinapic (s) acid, were synthesized for identification in oat extracts and for structure−antioxidant activity studies. Three compounds (2p, 2c, and 2f) were found in oat extracts. As assessed by the reactivity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH), all avenanthramides except 1p showed activity. Initially, the antioxidant activity of the avenanthramides decreased in a similar order as for the corresponding cinnamic acids, that is: sinapic > caffeic > ferulic > p-coumaric acid. The avenanthramides derived from 2 were usually slightly more active than those derived from 1. All avenanthramides inhibited azo-initiated peroxidation of linoleic acid. 1c and 1s were initially the most effective compounds. The relative order of antioxidant activities was slightly different for the DPPH and the linoleic acid assays run in methanol and chlorobenzene, respectively.

  • 44.
    Breistein, Palle
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Development of highly enantioselective organocatalyzed transformations2011Doctoral thesis, comprehensive summary (Other academic)
  • 45.
    Breistein, Palle
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Johansson, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Ibrahem, Ismail
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lin, S.
    Deiana, Luca
    Sun, J.
    Córdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    One-step catalytic enantioselective 5-hydroxy-α-quaternary proline synthesis: An asymmetric entry to highly functionalized α-quaternary proline derivativesManuscript (preprint) (Other academic)
  • 46.
    Breistein, Palle
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Karlsson, Staffan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Chiral pyrrolidinium salts as organocatalysts in stereoselective 1,4-conjugate addition of N-methylpyrrole to cyclopent-1-ene carbaldehyde2006In: Tetrahedron: Asymmetry, ISSN 0957-4166, Vol. 17, no 1, 107-111 p.Article in journal (Refereed)
  • 47.
    Bydén Sjöbom, Malin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Dependence of Alkyl Chain Asymmetry on the Phase Equilibria of Three Catanionic Surfactant Mixtures Containing Dodecyltrimethylammonium Chloride-Sodium Alkylcarboxylate-Water2002In: Langmuir, ISSN 0743-7463, Vol. 18, no 22, 8309-8317 p.Article in journal (Refereed)
  • 48.
    Bydén Sjöbom, Malin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lindström, Birger
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    BinaBinary Phase Equilibria and Structure of the Two α-Methyl-Substituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate ry Phase Exuilibria and Structure of the Chiral α-Methylsubstituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate1999In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 15, no 8, 2654-2660 p.Article in journal (Refereed)
    Abstract [en]

    In this study, we present the binary phase diagrams for the aqueous systems of the alkyldecanoic salts racemic sodium 2-methyldecanoate and sodium (R)-2-methyldecanoate, respectively. Both systems form a micellar solution phase, as well as a normal hexagonal, a cubic, and a lamellar liquid crystalline phase. They also form a very narrow intermediate phase, situated between the hexagonal and cubic liquid crystalline phases. The methods used for characterization were crossed polaroids, polarizing optical microscope and 2H NMR quadrupolar splittings combined with SAXS studies. The cubic phase gave a well-resolved SAXS diffraction pattern, with eight peaks present, which establishes the bicontinuous cubic structure as Ia3d. A significant difference in these two phase diagrams, compared to those of unsubstituted alkanoates with the same chain length, is the very low Krafft boundary.

  • 49.
    Bydén Sjöbom, Malin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Binary Phase Equilibria of Three alfa-Methylsubstituted Sodium Alkanoate Surfactant Systems.2003In: Journal of Colloid and Interface Science, ISSN 0021-9797, Vol. 257, no 2, 333-336 p.Article in journal (Refereed)
    Abstract [en]

    In this work, we continue our study of methyl -substituted surfactants and present the aqueous binary phase diagrams of racemic sodium 2-methyloctanoate, -nonanoate, and -dodecanoate, respectively. All systems have very low Krafft temperatures within the solution phase, between 1 and 4 degreesC. The phase sequences of the two shorter surfactants are very similar to those of the unsubstituted sodium octanoate, although with somewhat different range of existence for the phases formed. The sodium 2-methyldodecanoate system is different from the unsubstituted sodium dodecanoate system, as the former seems to lack a hexagonal phase. The surfactant systems were delineated using H-2 NMR splittings and crossed polarizers, and combined with SAXS for determination of phase structure. 

  • 50.
    Bydén Sjöbom, Malin
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Marques, Eduardo
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Khan, Ali
    Phase Equilibria of the Mixed Didodecyldimethylammonium Bromide-Taurodeoxycholate-Water System with a Large Solution Region.2005In: Colloids and Surfaces, ISSN 0166-6622, E-ISSN 1873-4340, Vol. 269, no 1-3, 87-95 p.Article in journal (Refereed)
    Abstract [en]

    The phase behavior over the entire concentration range for the system didodecyldimethylammonium bromide (DDAB)-sodium taurodeoxycholate (STDC)-water, at 25 degrees C, has been investigated, with emphasis on the DDAB-rich part. Polarizing microscopy, SAXS, H-2 NMR and H-1 self-diffusion NMR have been used in combination as probing techniques for phase behavior and microstructure. The system forms four major phases, all deriving from the respective binary surfactant systems. The two lamellar phases originating from the binary DDAB-water axis (D-I and D-II, at 3-30 and 83-91 wt.% DDAB, respectively) are only able to incorporate small amounts of STDC. The D-II phase solubilizes a comparatively higher amount of bile salt (up to ca. 6 wt.%), while the D, phase takes up less than 0.25 wt.%. From the STDC-water axis, a solution phase and a "hexagonal-like" liquid crystalline phase are derived, at 0-26 and 37-60 wt.% of STDC, respectively. Heterogeneous regions are also indicated on the basis of NMR and SAXS data. The most striking feature is the large extension of the isotropic solution phase, which originates from the water corner and curves toward the DDAB-rich side of the phase diagram. Even though at the upper limit of the solution phase the amount of water is reduced to 10 wt.%, the measured water and DDAB self-diffusion coefficients exclude the possibility of reverse-type structures.

1234567 1 - 50 of 432
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf