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  • 1.
    Alfredsson, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis and Characterization of Acrylfentanyl Metabolites2017Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Acrylfentanyl is a synthetic opioid that has been widely used in the last year. To help in the fight against synthetic drugs two potential metabolites of acrylfentanyl, one monohydroxy and one dihydroxy were synthesized. These metabolites will hopefully later be implemented in the analytical methods for metabolites of acrylfentanyl in urine by the Swedish National Board of Forensic Medicine.

    To have metabolites for analysis are very important as they are the main target in drug testing.

    The method used to synthesize the metabolites is a five-step synthesis with an additional 6th step for the dihydroxy metabolite. The methods used in the synthesis includes protection of amine with tert-butyloxycarbonyl, reductive amination with sodium triaceto boronhydride, alkylation and demethylation with boron tribromide. The methods used produced good results with high yields in nearly all steps.

  • 2.
    Alfredsson, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis and characterization of novel thiophene based tetramers for potential detection of protein aggregates2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Alzheimer’s disease is a big problem in the elderly population. An important tool in gaining insight in this disease are staining studies using different probes. Conjugated oligothiophenes have shown promising properties as probes and in this thesis new potential probes have been made.

    Three new tetrameric probes have been synthesized, consisting of three thiophene units and one aromatic heterocycle moiety. The aromatic heterocycles used were BTD, pyridine and indole. The synthesis method involved Suzuki cross coupling, bromination with NBS and iridium catalyst borylation. The BTD and pyridine containing probes were tested in staining experiments and the pyridine probe showed promising results.

  • 3.
    Andersson, Anna
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Harir, Mourad
    Helmholtz Zentrum München, Germany.
    Gonsior, Michael
    University of Maryland Center for Environmental Science, USA.
    Hertkorn, Norbert
    Helmholtz Zentrum München, Germany.
    Schmitt-Kopplin, Philippe
    Helmholtz Zentrum München, Germany.
    Kylin, Henrik
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Susanne
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Ashiq, Muhammad Jamshaid
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Lavonen, Elin
    Norrvatten, Kvalitet och Utveckling.
    Nilsson, Kerstin
    VA SYD.
    Pettersson, Ämma
    Nodra.
    Stavklint, Helena
    Tekniska verken i Linköping.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Waterworks-specific composition of drinking water disinfection by-products2019In: Environmental Science: Water Research & Technology, ISSN 2053-1419, no 5, p. 861-872Article in journal (Refereed)
    Abstract [en]

    Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64–92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited.This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future.

  • 4.
    Arja, Katriann
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Multimodal Porphyrin-Based Conjugates: Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Organic compounds that interact both with certain biological targets and display specific photophysical properties can be utilized as molecular tools to visualize and possibly effect disease related processes taking place in living organisms. In this regard, porphyrins are a class of naturally occurring molecules that possess intriguingly interesting photophysical properties where they can act as luminescent probes by emitting detectable light, as well as photosensitizers in the light mediated therapy called photodynamic therapy. In this thesis, the porphyrin structure has been synthetically combined with other molecule classes to achieve compounds with desirable multimodal characteristics.

    Firstly, luminescent conjugated oligothiophenes (LCOs) that have extensively, and with great success, been utilized as fluorescent ligands for amyloid formations, have been conjugated to porphyrins to render oligothiophene porphyrin hybrids (OTPHs) comprising two optically active modalities. When applied as fluorescent amyloidophilic dyes for visualization of amyloid-β (Aβ), one of the pathological hallmarks in Alzheimer’s disease, an enhanced optical assignment of distinct aggregated forms of Aβ was afforded.  Thus, properly functionalized OTPHs could give us more information about pathological processes underlying devastating disorders, such as Alzheimer’s disease. In addition, the OTPHs can be associated with synthetic peptides inducing peptide folding into certain three-dimensional helical structures giving rise to novel optically active materials.

    Secondly, this thesis also embraces porphyrins’ potential as photosensitizers in photodynamic therapy to kill cancer cells. Grounded on the prerequisites for an optimal photosensitizer, we designed porphyrin-based conjugates equipped with common carbohydrates for improved cancer cell selectivity and with a fluorinated glucose derivative, 2-fluoro 2-deoxy glucose, for advantageous metabolism in cancer cells. Furthermore, incorporation of a radioisotopic fluorine-18 atom into the glycoporphyrins could give the means for diagnostic use of the conjugates in positron emission tomography (PET).

    In order to tether together the above-mentioned molecular moieties in a controlled fashion, we developed a robust synthetic strategy for asymmetrical functionalization of porphyrin core. The method involves chlorosulfonation of this otherwise inert tetrapyrrolic structure, followed by alkynylation. Parallelly to amide coupling reactions, copper(I)-catalyzed alkyne azide cycloaddition is used for fast and high-yielding late-stage conjugations. Overall, this thesis demonstrates how combining different molecular moieties in synthetic organic chemistry yields novel molecules with combined and improved multimodal properties for biological and medicinal applications, guided by the design-by-function methodology.      

    List of papers
    1. Enhanced Fluorescent Assignment of Protein Aggregates by an Oligothiophene-Porphyrin-Based Amyloid Ligand
    Open this publication in new window or tab >>Enhanced Fluorescent Assignment of Protein Aggregates by an Oligothiophene-Porphyrin-Based Amyloid Ligand
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    2013 (English)In: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 34, no 9, p. 723-730Article in journal (Refereed) Published
    Abstract [en]

    Fluorescent probes identifying protein aggregates are of great interest, as deposition of aggregated proteins is associated with many devastating diseases. Here, we report that a fluorescent amyloid ligand composed of two distinct molecular moieties, an amyloidophilic pentameric oligothiophene and a porphyrin, can be utilized for spectral and lifetime imaging assessment of recombinant A 1-42 amyloid fibrils and A deposits in brain tissue sections from a transgenic mouse model with Alzheimers disease pathology. The enhanced spectral range and distinct lifetime diversity of this novel oligothiopheneporphyrin-based ligand allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye.

    Place, publisher, year, edition, pages
    Wiley-VCH Verlag, 2013
    Keywords
    oligothiophene, porphyrin, protein deposits, imaging, fluorescence
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-93385 (URN)10.1002/marc.201200817 (DOI)000318354500004 ()
    Note

    Funding Agencies|Swedish Research Council||Knut and Alice Wallenberg Foundation||Swedish Foundation for Strategic Research||European Union FP7 HEALTH (Project LUPAS)||LiU Neuroscience Center||ERC Starting Independent Researcher grant (Project: MUMID)||

    Available from: 2013-05-31 Created: 2013-05-31 Last updated: 2018-08-24
    2. Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-beta Morphotypes
    Open this publication in new window or tab >>Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-beta Morphotypes
    2018 (English)In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 6, article id 391Article in journal (Refereed) Published
    Abstract [en]

    Molecular tools for fluorescent imaging of protein aggregates are essential for understanding the significance of these pathological hallmarks in proteopathic neurodegenerative diseases, such as Alzheimers disease. Here, we report the synthesis of a series of oligothiophene porphyrin hybrids, OTPHs, and the evaluation of these dyes for fluorescent imaging of beta-amyloid aggregates in tissue sections from a transgenic mouse model with Alzheimers disease pathology. The OTPHs proved to be successful for spectral and lifetime imaging assessment of protein deposits and our findings confirm that the enhanced spectral range and distinct lifetime diversity of these novel tools allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye. In addition, the chemical identity of the porphyrin moiety, as well as the spacing between the two optical active moieties, influenced the OTPHs performance for fluorescent assignment of the protein deposits. We foresee that our findings will aid in the chemical design of dyes that can be utilized as optical tools for studying the polymorphic nature of protein aggregates associated with proteopathic neurodegenerative diseases.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2018
    Keywords
    oligothiophene; porphyrin; protein deposits; imaging; fluorescence
    National Category
    Biophysics
    Identifiers
    urn:nbn:se:liu:diva-151479 (URN)10.3389/fchem.2018.00391 (DOI)000443424100001 ()30234103 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [621-2013-4754, 2016-00748]

    Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2018-10-19
    3. Synthesis and Characterization of Novel Fluoro-glycosylated Porphyrins that can be Utilized as Theranostic Agents
    Open this publication in new window or tab >>Synthesis and Characterization of Novel Fluoro-glycosylated Porphyrins that can be Utilized as Theranostic Agents
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    2018 (English)In: ChemistryOpen, ISSN 2191-1363, Vol. 7, no 7, p. 495-503Article in journal (Refereed) Published
    Abstract [en]

    Small molecules with modalities for a variety of imaging techniques as well as therapeutic activity are essential, as such molecules render opportunities to simultaneously conduct diagnosis and targeted therapy, so called theranostics. In this regard, glycoporphyrins have proven useful as theranostic agents towards cancer, as well as noncancerous conditions. Herein, the synthesis and characterization of heterobifunctional glycoconjugated porphyrins with two different sugar moieties, a common monosaccharide at three sites, and a 2-fluoro-2-deoxy glucose (FDG) moiety at the fourth site are presented. The fluoro-glycoconjugated porphyrins exhibit properties for multimodal imaging and photodynamic therapy, as well as specificity towards cancer cells. We foresee that our findings might aid in the chemical design of heterobifunctional glycoconjugated porphyrins that could be utilized as theranostic agents.

    Place, publisher, year, edition, pages
    Wiley-VCH Verlagsgesellschaft, 2018
    Keywords
    cancer; glycoporphyrins; imaging; photodynamic therapy; photosensitizers
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:liu:diva-150279 (URN)10.1002/open.201800020 (DOI)000440286200002 ()30003003 (PubMedID)2-s2.0-85051290816 (Scopus ID)
    Note

    Funding Agencies|Swedish Foundation for Strategic Research; Swedish Research Council

    Available from: 2018-08-17 Created: 2018-08-17 Last updated: 2019-04-01Bibliographically approved
  • 5.
    Björk, Linnea
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Synthesis of proteophenes that can be utilized as fluorescent ligands for biological targets2019Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Small fluorescent probes are important tools when studying protein aggregates involved in different neurodegenerative diseases, such as Alzheimer’s disease. Luminescent conjugated oligothiophenes have been developed and shown to be excellent ligands when studying morphology among amyloids, due to their conjugated thiophene backbone that provides them with unique photophysical properties. This kind of probes are being developed successively to enhance the specificity of their biological targets. In this project, luminescent conjugated oligothiophenes functionalized with amino acids, so called proteophenes, have been synthesized to investigate their optical properties. Since amino acids are chiral molecules, the possibility of induced chirality to the thiophene backbone was examined, as well as the proteophenes ability to work as amyloidospecific ligands for the study of protein aggregates. The synthesis of four different proteophenes are presented in this report, along with analysis results of their photophysical properties.

  • 6.
    Bykov, Maxim
    et al.
    Univ Bayreuth, Germany.
    Chariton, Stella
    Univ Bayreuth, Germany.
    Fei, Hongzhan
    Univ Bayreuth, Germany.
    Fedotenko, Timofey
    Univ Bayreuth, Germany.
    Aprilis, Georgios
    Univ Bayreuth, Germany.
    Ponomareva, Alena V
    Natl Univ Sci and Technol MISIS, Russia.
    Tasnadi, Ferenc
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Abrikosov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Merle, Benoit
    Friedrich Alexander Univ Erlangen Nurnberg FAU, Germany.
    Feldners, Patrick
    Friedrich Alexander Univ Erlangen Nurnberg FAU, Germany.
    Vogel, Sebastian
    Univ Munich LMU, Germany.
    Schnick, Wolfgang
    Univ Munich LMU, Germany.
    Prakapenka, Vitali B.
    Univ Chicago, IL 60637 USA.
    Greenberg, Eran
    Univ Chicago, IL 60637 USA.
    Hanfland, Michael
    European Synchrotron Radiat Facil, France.
    Pakhomova, Anna
    DESY, Germany.
    Liermann, Hanns-Peter
    DESY, Germany.
    Katsura, Tomoo
    Univ Bayreuth, Germany.
    Dubrovinskaia, Natalia
    Univ Bayreuth, Germany.
    Dubrovinsky, Leonid
    Univ Bayreuth, Germany.
    High-pressure synthesis of ultraincompressible hard rhenium nitride pernitride Re-2(N-2)(N)(2) stable at ambient conditions2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 2994Article in journal (Refereed)
    Abstract [en]

    High-pressure synthesis in diamond anvil cells can yield unique compounds with advanced properties, but often they are either unrecoverable at ambient conditions or produced in quantity insufficient for properties characterization. Here we report the synthesis of metallic, ultraincompressible (K-0 = 428(10) GPa), and very hard (nanoindentation hardness 36.7(8) GPa) rhenium nitride pernitride Re-2(N-2)(N)(2). Unlike known transition metals pernitrides Re-2(N-2)(N)(2) contains both pernitride N-2(4-) and discrete N3- anions, which explains its exceptional properties. Re-2(N-2)(N)(2) can be obtained via a reaction between rhenium and nitrogen in a diamond anvil cell at pressures from 40 to 90 GPa and is recoverable at ambient conditions. We develop a route to scale up its synthesis through a reaction between rhenium and ammonium azide, NH4N3, in a large-volume press at 33 GPa. Although metallic bonding is typically seen incompatible with intrinsic hardness, Re-2(N-2)(N)(2) turned to be at a threshold for superhard materials.

  • 7.
    Bäck, Marcus
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, The Institute of Technology.
    Design and Synthesis of Hepatitis C Virus NS3 Protease Inhibitors Incorporating a P2 Cyclopentane-Derived Scaffold2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

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

    List of papers
    1. Potent inhibitors of the hepatitis C virus NS3 protease: use of a novel P2 cyclopentane-derived template
    Open this publication in new window or tab >>Potent inhibitors of the hepatitis C virus NS3 protease: use of a novel P2 cyclopentane-derived template
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    2006 (English)In: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, E-ISSN 1464-3391, Vol. 14, no 15, p. 5136-5151Article in journal (Refereed) Published
    Abstract [en]

    The HCV NS3 protease is essential for replication of the hepatitis C virus (HCV) and therefore constitutes a promising new drug target for anti-HCV therapy. Several potent and promising HCV NS3 protease inhibitors, some of which display low nanomolar activities, were identified from a series of novel inhibitors incorporating a trisubstituted cyclopentane dicarboxylic acid moiety as a surrogate for the widely used N-acyl-(4R)-hydroxyproline in the P2 position.

    Keywords
    HCV, NS3, Protease inhibitor, Cyclopentane-derived P2 scaffold
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-14308 (URN)10.1016/j.bmc.2006.04.008 (DOI)
    Available from: 2007-02-21 Created: 2007-02-21 Last updated: 2017-12-13Bibliographically approved
    2. Potent Macrocyclic Inhibitors of the Hepatitis C Virus NS3 Protease. Use of Cyclopentane and Cyclopentene Derived P2-Scaffolds
    Open this publication in new window or tab >>Potent Macrocyclic Inhibitors of the Hepatitis C Virus NS3 Protease. Use of Cyclopentane and Cyclopentene Derived P2-Scaffolds
    Show others...
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14309 (URN)
    Available from: 2007-02-21 Created: 2007-02-21 Last updated: 2010-01-13
  • 8.
    Bäcklund, Fredrik G.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Pallbo, Jon
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Controlling Amyloid Fibril Formation by Partial Stirring2016In: Biopolymers, ISSN 0006-3525, E-ISSN 1097-0282, Vol. 105, no 5, p. 249-259Article in journal (Refereed)
    Abstract [en]

    Many proteins undergoes self-assembly into fibrillar structures known as amyloid fibrils. During the self-assembly process related structures, known as spherulites, can be formed. Herein we report a facile method where the balance between amyloid fibrils and spherulites can be controlled by stirring of the reaction mixture during the initial stages of the self-assembly process. Moreover, we report how this methodology can be used to prepare non-covalently functionalized amyloid fibrils. By stirring the reaction mixture continuously or for a limited time during the lag phase the fibril length, and hence the propensity to form liquid crystalline phases, can be influenced. This phenomena is utilized by preparing films consisting of aligned protein fibrils incorporating the laser dye Nile red. The resulting films display polarized Nile red fluorescence.

  • 9.
    Bäcklund, Fredrik G.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tuning the aqueous self-assembly process of insulin by a hydrophobic additive2015In: RSC ADVANCES, ISSN 2046-2069, Vol. 5, no 112, p. 92254-92262Article in journal (Refereed)
    Abstract [en]

    Biomolecular self-assembly is an efficient way of preparing soft-matter based materials. Herein we report a novel method, based on the use of insoluble additives in aqueous media, for influencing the self-assembly process. Due to their low solubility, the use of hydrophobic additives in aqueous media is problematic; however, by mixing the additive with the biomolecule in the solid state, prior to solvation, this problem can be circumvented. In the investigated self-assembly system, where bovine insulin self-assembles into spherical structures, the inclusion of the hydrophobic material α-sexithiophene (6T) results in significant changes in the self-assembly process. Under our reaction conditions, in the case of materials prepared from insulin-only the growth of spherulites typically stops at a diameter of 150μm. However, by adding 2 weight % of hydrophobic material, spherulite growth continues up to diameters in the mm-range. The spherulites incorporate 6T and are thus fluorescent. The method reported herein should be of interest to all scientists working in the field of self-assembly as the flexible materials preparation, based simply on co-grinding of commercially available materials, adds another option to influence the structure and properties of products formed by  self-assembly reactions.

  • 10.
    Bäcklund, Fredrik Gustaf
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ajjan, Fátima Nadia
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Convection Induced Air-Water Interface Assembly of Amyloid FibrilsManuscript (preprint) (Other academic)
    Abstract [en]

    We report that hydrophobically modified amyloid fibrils form macroscopic films at the air-water interface. The hydrophobically modified fibrils are prepared in a two step process. First bovine insulin is ground with a hydrophobic compound. The resulting material is dissolved in acidic water and heated to induce assembly into fibrils incorporating the hydrophobic compounds. Upon dilution followed by asymmetric heating, resulting in convection flow, the fibrills form highly ordered films with thicknesses from 80 nm and up. The thickness of the film can be controlled by the fibril concentration and/or reaction time. The films contain anisotropic domains spanning several square centimeters. In addition, the films contains ordered assemblies of dyes that display emission of polarized light.

  • 11.
    Carlsson, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering. Swedish National Forens Centre NFC, Linkoping, Sweden.
    Synthesis and spectroscopic characterization of emerging synthetic cannabinoids and cathinones2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The application of different analytical techniques is fundamental in forensic drug analysis. In the wake of the occurrence of large numbers of new psychoactive substances possessing similar chemical structures as already known ones, focus has been placed on applied criteria for their univocal identification. These criteria vary, obviously, depending on the applied technique and analytical approach. However, when two or more substances are proven to have similar analytical properties, these criteria no longer apply, which imply that complementary techniques have to be used in their differentiation.

    This work describes the synthesis of some structural analogues to synthetic cannabinoids and cathinones based on the evolving patterns in the illicit drug market. Six synthetic cannabinoids and six synthetic cathinones were synthesized, that, at the time for this study, were not as yet found in drug seizures. Further, a selection of their spectroscopic data is compared to those of already existing analogues; mainly isomers and homologues. The applied techniques were mass spectrometry (MS), Fourier transformed infrared (FTIR, gas phase) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. In total, 59 different compounds were analyzed with the  selected techniques.

    The results from comparison of spectroscopic data showed that isomeric substances may in some cases be difficult to unambiguously identify based only on their GC-MS EI spectra. On the other hand, GC-FTIR demonstrated more distinguishable spectra. The spectra for the homologous compounds showed however, that the GC-FTIR technique was less successful compared to GC-MS. Also a pronounced fragmentation pattern for some of the cathinones was found.

    In conclusion, this thesis highlights the importance of using complementary techniques for the univocal identification of synthetic cannabinoids and cathinones. By increasing the number of analogues investigated, the more may be learnt about the capabilities of different techniques for structural differentiations, and thereby providing important identification criteria leading to trustworthy forensic evidence.

    List of papers
    1. Prediction of designer drugs: synthesis and spectroscopic analysis of synthetic cannabinoid analogues of 1H-indol-3-yl(2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone
    Open this publication in new window or tab >>Prediction of designer drugs: synthesis and spectroscopic analysis of synthetic cannabinoid analogues of 1H-indol-3-yl(2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone
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    2016 (English)In: Drug Testing and Analysis, ISSN 1942-7603, E-ISSN 1942-7611, Vol. 8, no 10, p. 1015-1029Article in journal (Refereed) Published
    Abstract [en]

    In this work, emergence patterns of synthetic cannabinoids were utilized in an attempt to predict those that may appear on the drug market in the future. Based on this information, two base structures of the synthetic cannabinoid analogues - (1H-indol-3-yl (2,2,3,3-tetramethylcyclopropyl) methanone and 1H-indol-3-yl(adamantan-1-yl)methanone) - together with three substituents butyl, 4-fluorobutyl and ethyl tetrahydropyran - were selected for synthesis. This resulted in a total of six synthetic cannabinoid analogues that to the authors knowledge have not yet appeared on the drug market. Spectroscopic data, including nuclearmagnetic resonance (NMR), mass spectrometry (MS), and Fourier transforminfrared (FTIR) spectroscopy (solid and gas phase), are presented for the synthesized analogues and some additional related cannabinoids. In this context, the suitability of the employed techniques for the identification of unknowns is discussed and the use of GC-FTIR as a secondary complementary technique to GC-MS is addressed. Examples of compounds that are difficult to differentiate by their mass spectra, but can be distinguished based upon their gas phase FTIR spectra are presented. Conversely, structural homologueswhere mass spectra aremore powerful than gas phase FTIR spectra for unambiguous assignments are also exemplified. This work further emphasizes that a combination of several techniques is the key to success in structural elucidations. Copyright (C) 2015 John Wiley amp; Sons, Ltd.

    Place, publisher, year, edition, pages
    WILEY-BLACKWELL, 2016
    Keywords
    drug analysis; proactive; synthetic cannabinoids; synthesis; mass spectrometry
    National Category
    Pharmaceutical Sciences
    Identifiers
    urn:nbn:se:liu:diva-132473 (URN)10.1002/dta.1904 (DOI)000384806400003 ()26526273 (PubMedID)
    Note

    Funding Agencies|Swedish Contingencies Agency (MSB)

    Available from: 2016-11-13 Created: 2016-11-12 Last updated: 2018-01-13
  • 12.
    Cirera, B.
    et al.
    IMDEA Nanosci, Spain.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Otero, R.
    IMDEA Nanosci, Spain; University of Autonoma Madrid, Spain.
    Gallego, J. M.
    CSIC, Spain.
    Miranda, R.
    IMDEA Nanosci, Spain; University of Autonoma Madrid, Spain.
    Ecija, D.
    IMDEA Nanosci, Spain.
    Efficient Lanthanide Catalyzed Debromination and Oligomeric Length-Controlled Ullmann Coupling of Aryl Halides2017In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 14, p. 8033-8041Article in journal (Refereed)
    Abstract [en]

    Lanthanide elements play a vital role in a broad range of high-tech applications, and there is an increasing interest in their catalytic activity, particularly in organo-metallics. However, their catalytic role on surfaces remains unexplored. Here, we present a scanning tunneling microscopy and density functional theory study of the debromination, contacting, and coupling of dibromine terphenyl species with Dy (f-block element) and Ag (d-block element) adatoms, respectively. We show that Dy debrominates the targeted species more efficiently than Ag adatoms at room temperature, promoting the formation of unprecedented C-Dy-C organo-metallic supramolecules versus C-Ag-C parallel chains for the Ag case. DFT calculations corroborate our results showing an almost spontaneous debromination process with Dy compared to Ag. Upon annealing, for samples containing Dy, the formation of C-Ag-C organometallic bonds and concomitant C-C coupling is inhibited, giving rise to a self-assembly of debrominated monomers, showing only a minority number of covalent dimes species. For samples without Dy covalent chains of irregular length are promoted. Our studies open new avenues for using lanthanide elements as efficient dehalogenation catalysts. Furthermore, we illustrate their potential as inhibitors of uncontrolled C-C coupling reactions, of great relevance for fine-tuning the length of polymeric compounds.

  • 13.
    Das, Biswanath
    et al.
    Lund University, Sweden.
    Lee, Bao-Lin
    Stockholm University, Sweden.
    Karlsson, Erik A.
    Stockholm University, Sweden.
    Akermark, Torbjorn
    Stockholm University, Sweden.
    Shatskiy, Andrey
    Stockholm University, Sweden.
    Demeshko, Serhiy
    University of Gottingen, Germany.
    Liao, Rong-Zhen
    Huazhong University of Science and Technology, Peoples R China.
    Laine, Tanja M.
    Stockholm University, Sweden.
    Haukka, Matti
    University of Jyvaskyla, Finland.
    Zeglio, Erica
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Abdel-Magied, Ahmed F.
    Stockholm University, Sweden.
    Siegbahn, Per E. M.
    Stockholm University, Sweden.
    Meyer, Franc
    University of Gottingen, Germany.
    Karkas, Markus D.
    Stockholm University, Sweden.
    Johnston, Eric V.
    Stockholm University, Sweden.
    Nordlander, Ebbe
    Lund University, Sweden.
    Åkermark, Bjorn
    Stockholm University, Sweden.
    Water oxidation catalyzed by molecular di- and nonanuclear Fe complexes: importance of a proper ligand framework2016In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 45, no 34, p. 13289-13293Article in journal (Refereed)
    Abstract [en]

    The synthesis of two molecular iron complexes, a dinuclear iron(III,III) complex and a nonanuclear iron complex, based on the di-nucleating ligand 2,2-(2-hydroxy-5-methyl-1,3-phenylene)bis(1H-benzo[d]imidazole-4-carboxylic acid) is described. The two iron complexes were found to drive the oxidation of water by the one-electron oxidant [Ru(bpy)(3)](3+).

  • 14.
    Elgland, Mathias
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Synthesis and application of β-configured [18/19F]FDGs: Novel prosthetic CuAAC click chemistry fluoroglycosylation tools for amyloid PET imaging and cancer theranostics2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Positron emission tomography (PET) is a non-invasive imaging method that renders three-dimensional images of tissue that selectively has taken up a radiolabelled organic compound, referred to as a radiotracer. This excellent technique provides clinicians with a tool to monitor disease progression and to evaluate how the patient respond to treatment. The by far most widely employed radiotracer in PET is called 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), which is often referred to as the golden standard in PET. From a molecular perspective, [18F]FDG is an analogue of glucose where a hydroxyl group has been replaced with a radioactive fluorine atom (18F). It is well known that covalent attachment of carbohydrates (i.e., glycosylation) to biomolecules tend to improve their properties in the body, in terms of; improved pharmacokinetics, increased metabolic stability and faster clearance from blood and other non-specific tissue. It is therefore natural to pursuit the development of a [18F]fluoroglycosylation method where [18F]FDG is chemically conjugated to a ligand with high affinity for a given biological target (e.g., tumors or disease-associated protein aggregates).

    This thesis describes a novel [18F]fluoroglycosylation method that in a simple and general manner facilitate the conjugation of [18F]FDG to biological ligands using click chemistry. The utility of the developed [18F]fluoroglycosylation method is demonstrated by radiolabelling of curcumin, thus forming a tracer that may be employed for diagnosis of Alzheimer’s disease. Moreover, a set of oligothiophenes were fluoroglycosylated for potential diagnosis of Alzheimer’s disease but also for other much rarer protein misfolding diseases (e.g., Creutzfeldt-Jakob disease and systemic amyloidosis). In addition, the synthesis of a series of 19F-fluoroglycosylated porphyrins is described which exhibited promising properties not only to detect but also to treat melanoma cancer. Lastly, the synthesis of a set of 19F-fluorinated E-stilbenes, structurally based on the antioxidant resveratrol is presented. The E-stilbenes were evaluated for their capacity to spectrally distinguish between native and protofibrillar transthyretin in the pursuit of finding diagnostic markers for the rare but severe disease, transthyretin amyloidosis.

    List of papers
    1. beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET
    Open this publication in new window or tab >>beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET
    Show others...
    2017 (English)In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 41, no 18, p. 10231-10236Article in journal (Refereed) Published
    Abstract [en]

    In oncology and neurology the F-18-radiolabeled glucose analogue 2-deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) is by far the most commonly employed metabolic imaging agent for positron emission tomography (PET). Herein, we report a novel synthetic route to beta-configured mannopyranoside precursors and a chemoselective F-18-fluoroglycosylation method that employ two b-configured [F-18]FDG derivatives equipped with either a terminal azide or alkyne aglycon respectively, for use as a CuAAC clickable tool set for PET. The b-configured precursors provided the corresponding [F-18]FDGs in a radiochemical yield of 77-88%. Further, the clickability of these [F-18]FDGs was investigated by click coupling to the suitably functionalized Fmoc-protected amino acids, Fmoc-N-(propargyl)-glycine and Fmoc-3-azido-L-alanine, which provided the F-18-fluoroglycosylated amino acid conjugates in radiochemical yields of 75-83%. The F-18-fluoroglycosylated amino acids presented herein constitute a new and interesting class of metabolic PET radiotracers.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2017
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:liu:diva-141934 (URN)10.1039/c7nj00716g (DOI)000411767400073 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic Research; Swedish Research Council

    Available from: 2017-10-13 Created: 2017-10-13 Last updated: 2018-02-21
    2. Novel Trans-Stilbene-based Fluorophores as Probes for Spectral Discrimination of Native and Protofibrillar Transthyretin
    Open this publication in new window or tab >>Novel Trans-Stilbene-based Fluorophores as Probes for Spectral Discrimination of Native and Protofibrillar Transthyretin
    Show others...
    2016 (English)In: ACS Chemical Neuroscience, ISSN 1948-7193, E-ISSN 1948-7193, Vol. 7, no 7, p. 924-940Article in journal (Refereed) Published
    Abstract [en]

    Accumulation of misfolded transthyretin (TTR) as amyloid fibrils causes various human disorders. Native transthyretin is a neurotrophic protein and is a putative extracellular molecular chaperone. Several fluorophores have been shown in vitro to bind selectively to native TTR. Other compounds, such as thioflavin T, bind TTR amyloid fibrils. The probe 1-anilinonaphthalene-8-sulfonate (ANS) binds to both native and fibrillar TTR, becoming highly fluorescent, but with indistinguishable emission spectra for native and fibrillar TTR. Herein we report our efforts to develop a fluorescent small molecule capable of binding both native and misfolded protofibrillar TTR, providing distinguishable emission spectra. We used microwave synthesis for efficient production of a small library of trans-stilbenes and fluorescence spectral screening of their binding properties. We synthesized and tested 22 trans-stilbenes displaying a variety of functional groups. We successfully developed two naphthyl-based trans-stilbenes probes that detect both TTR states at physiological concentrations. The compounds bound with nanomolar to micromolar affinities and displayed distinct emission maxima upon binding native or misfolded protofibrillar TTR (>100 nm difference). The probes were mainly responsive to environment polarity providing evidence for the divergent hydrophobic structure of the binding sites of these protein conformational states. Furthermore, we were able to successfully use one of these probes to quantify the relative amounts of native and protofibrillar TTR in a dynamic equilibrium. In conclusion, we identified two trans-stilbene-based fluorescent probes, (E)-4-(2-(naphthalen-1-yl)vinyl)benzene-1,2-diol (11) and (E)-4-(2-(naphthalen-2-yl)vinyl)benzene-1,2-diol (14), that bind native and protofibrillar TTR, providing a wide difference in emission maxima allowing conformational discrimination by fluorescence spectroscopy. We expect these novel molecules to serve as important chemical biology research tools in studies of TTR folding and misfolding.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2016
    Keywords
    transthyretin, amyloid, stilbene, fluorescence, probe, spectrum
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-122842 (URN)10.1021/acschemneuro.6b00062 (DOI)000380297500009 ()27144293 (PubMedID)
    Note

    At the time for thesis presentation publication was in status: Manuscript

    Funding agencies:The work was supported by Goran Gustafsson's Foundation (PH), The Swedish Research Council (PH), The Linkoping center for systemic neuroscience, LiU-Neuro, (XW), and Sven and Lilly Lawski's foundation (ME).

    Available from: 2015-11-26 Created: 2015-11-26 Last updated: 2018-04-25Bibliographically approved
  • 15.
    Elgland, Mathias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Nordeman, P.
    Uppsala University, Sweden.
    Fyrner, Timmy
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Antoni, G.
    Uppsala University, Sweden.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    beta-Configured clickable [F-18] FDGs as novel F-18-fluoroglycosylation tools for PET2017In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 41, no 18, p. 10231-10236Article in journal (Refereed)
    Abstract [en]

    In oncology and neurology the F-18-radiolabeled glucose analogue 2-deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) is by far the most commonly employed metabolic imaging agent for positron emission tomography (PET). Herein, we report a novel synthetic route to beta-configured mannopyranoside precursors and a chemoselective F-18-fluoroglycosylation method that employ two b-configured [F-18]FDG derivatives equipped with either a terminal azide or alkyne aglycon respectively, for use as a CuAAC clickable tool set for PET. The b-configured precursors provided the corresponding [F-18]FDGs in a radiochemical yield of 77-88%. Further, the clickability of these [F-18]FDGs was investigated by click coupling to the suitably functionalized Fmoc-protected amino acids, Fmoc-N-(propargyl)-glycine and Fmoc-3-azido-L-alanine, which provided the F-18-fluoroglycosylated amino acid conjugates in radiochemical yields of 75-83%. The F-18-fluoroglycosylated amino acids presented herein constitute a new and interesting class of metabolic PET radiotracers.

  • 16.
    Fors, Jonathan
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Modeling and OpenFOAM simulation of streamers in transformer oil2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electric breakdown in power transformers is preceded by pre-breakdown events such as streamers. The understanding of these phenomena is important in order to optimize liquid insulation systems. Earlier works have derived a model that describes streamers in transformer oil and utilized a finite element method to produce numerical solutions. This research investigates the consequences of changing the numerical method to a finite volume-based solver implemented in OpenFOAM. Using a standardized needle-sphere geometry, a number of oil and voltage combinations were simulated, and the results are for the most part similar to those produced by the previous method. In cases with differing results the change is attributed to the more stable numerical performance of the OpenFOAM solver. A proof of concept for the extension of the simulation from a two-dimensional axial symmetry to three dimensions is also presented.

  • 17.
    Fyrner, Timmy
    Linköping University, The Department of Physics, Chemistry and Biology.
    Synthesis of Structures Related to Antifreeze Glycoproteins2005Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    In this thesis, synthesis of structures related to antifreeze glycoproteins (AFGPs) are presented. Synthetic routes to a protected carbohydrate derivative, 2,3,4,6-tetra-O-benzyl-β-galactopyranosyl-(1→3)-2-deoxy-2-azido-4,6-di-O-benzyl-β-D-thio-1-galactopyranoside, and a tBu-Ala-Thr-Ala-Fmoc tripeptide, are described. These compounds are meant to be used in the assembly of AFGPs and analogues thereof. A Gal-GlcN disaccharide was synthesized via glycosylation between the donor, bromo-2-O-benzoyl-3,4,6-tri-O-benzyl-α-Dgalactopyranoside, and acceptor, ethyl 4,6-O-benzylidene-2-deoxy-2-N-phthalimido-β-D-1-thio-glucopyranoside, using silver triflate activation. Subsequent epimerization to a Gal-GalN disaccharide was achieved using Moffatt oxidation followed by L-selectride® reduction. The tripeptide was synthesized in a short and convenient manner using solid phase peptide synthesis with immobilized Fmoc-Ala on Wang® resins as starting point.

  • 18.
    Garcia-Iglesias, Miguel
    et al.
    Eindhoven University of Technology, Netherlands.
    de Waal, Bas F. M.
    Eindhoven University of Technology, Netherlands.
    Gorbunov, Andrey V.
    Eindhoven University of Technology, Netherlands.
    Palmans, Anja R. A.
    Eindhoven University of Technology, Netherlands.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering. Eindhoven University of Technology, Netherlands.
    Meijer, E. W.
    Eindhoven University of Technology, Netherlands.
    A Versatile Method for the Preparation of Ferroelectric Supramolecular Materials via Radical End-Functionalization of Vinylidene Fluoride Oligomers2016In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, no 19, p. 6217-6223Article in journal (Refereed)
    Abstract [en]

    A synthetic method for the end-functionalization of vinylidene fluoride oligomers (OVDF) via a radical reaction between terminal olefins and I-OVDF is described. The method shows a wide substrate scope and excellent conversions, and permits the preparation of different disc-shaped cores such as benzene-1,3,5-tricarboxamides (BTAs), perylenes bisimide and phthalocyanines (Pc) bearing three to eight ferroelectric oligomers at their periphery. The formation, purity, OVDF conformation, and morphology of the final adducts has been assessed by a combination of techniques, such as NMR, size exclusion chromatography, differential scanning calorimetry, polarized optical microscopy, and atomic force microscopy. Finally, PBI-OVDF and Pc-OVDF materials show ferroelectric hysteresis behavior together with high remnant polarizations, with values as high as P-r approximate to 37 mC/m(2) for Pc-OVDF. This work demonstrates the potential of preparing a new set of ferroelectric materials simply by attaching OVDF oligomers to different small molecules. The use of carefully chosen small molecules paves the way to new functional materials in which ferroelectricity and electrical conductivity or light-harvesting properties coexist in a single compound.

  • 19.
    Hellwig, Raphael
    et al.
    Tech Univ Munich, Germany.
    Uphoff, Martin
    Tech Univ Munich, Germany.
    Paintner, Tobias
    Tech Univ Munich, Germany.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Ruben, Mario
    KIT, Sweden; Univ Strasbourg, France.
    Klappenberger, Florian
    Tech Univ Munich, Germany.
    Barth, Johannes V.
    Tech Univ Munich, Germany.
    Ho-Mediated Alkyne Reactions at Low Temperatures on Ag(111)2018In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, no 60, p. 16126-16135Article in journal (Refereed)
    Abstract [en]

    Low-temperature approaches to catalytic conversions promise efficiency, selectivity, and sustainable processes. Control over certain coupling reactions can be obtained via the pre-positioning of reactive moieties by self-assembly. However, in the striving field of on-surface synthesis atomistic precision and control remains largely elusive, because the employed coupling reactions proceed at temperatures beyond the thermal stability of the supramolecular templates. Here, utilizing scanning tunneling microscopy, we demonstrate terminal alkyne on-surface reactions mediated by Ho atoms at a weakly reactive Ag(111) substrate at lowtemperatures. Density functional theory calculations confirm the catalytic activity of the involved adatoms. Pre-deposited Ho induces alkyne dehydrogenation starting at substrate temperatures as low as 100 K. Ho arriving at molecularly pre-covered surfaces held at 130 and 200 K produces covalent enyne-linked dimers and initiates cyclotrimerization, respectively. Statistical product analysis indicates a two-step pathway for the latter, whereby the enyne intermediates influence the distribution of the products. High chemoselectivity results from the absence of cyclotetramerization and diyne-forming homocoupling. Our analysis indicates that mainly the arriving Ho adatoms enable the coupling. These findings support the concept of dynamic heterogeneity by single-atom catalysts and pave the way for alternative means to control on-surface reactions.

  • 20.
    Hur, Deniz
    et al.
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Say, Mehmet Girayhan
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Bionkit Co Ltd, Turkey.
    Diltemiz, Sibel E.
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Duman, Fatma
    Anadolu Univ, Turkey.
    Ersoz, Arzu
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    Say, Ridvan
    Anadolu Univ, Turkey; Bionkit Co Ltd, Turkey.
    3D Micropatterned All-Flexible Microfluidic Platform for Microwave-Assisted Flow Organic Synthesis2018In: CHEMPLUSCHEM, ISSN 2192-6506, Vol. 83, no 1, p. 42-46Article in journal (Refereed)
    Abstract [en]

    A large-area, all-flexible, microwaveable polydimethoxysilane microfluidic reactor was fabricated by using a 3D printing system. The sacrificial microchannels were printed on polydimethoxysilane substrates by a direct ink writing method using water-soluble Pluronic F-127 ink and then encapsulated between polydimethoxysilane layers. The structure of micron-sized channels was analyzed by optical and electron microscopy techniques. The fabricated flexible microfluidic reactors were utilized for the acetylation of different amines under microwave irradiation to obtain acetamides in shorter reaction times and good yields by flow organic synthesis.

  • 21.
    Klingstedt, Therése
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Åslund, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Simon, Rozalyn
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Johansson, Leif B. G.
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Mason, Jeffrey
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Nyström, Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Protein Science. Linköping University, The Institute of Technology.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Protein Science. Linköping University, The Institute of Technology.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Synthesis of a library of oligothiophenes and their utilization as fluorescent ligands for spectral assignment of protein aggregates2011In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 9, no 24, p. 8356-8370Article in journal (Refereed)
    Abstract [en]

    Molecular probes for selective identification of protein aggregates are important to advance our understanding of the molecular pathogenesis underlying protein aggregation diseases. Here we report the chemical design of a library of anionic luminescent conjugated oligothiophenes (LCOs), which can be utilized as ligands for detection of protein aggregates. Certain molecular requirements were shown to be necessary for detecting (i) early non-thioflavinophilic protein assemblies of A beta 1-42 and insulin preceding the formation of amyloid fibrils and (ii) for obtaining distinct spectral signatures of the two main pathological hallmarks observed in human Alzheimers diease brain tissue (A beta plaques and neurofibrillary tangles). Our findings suggest that a superior anionic LCO-based ligand should have a backbone consisting of five to seven thiophene units and carboxyl groups extending the conjugated thiophene backbone. Such LCOs will be highly useful for studying the underlying molecular events of protein aggregation diseases and could also be utilized for the development of novel diagnostic tools for these diseases.

  • 22.
    Lai, Kwok Kei
    et al.
    Hong Kong University of Science and Technology, Clear Water Bay, P. R. China .
    Renneberg, Reinhard
    Hong Kong University of Science and Technology, Clear Water Bay, P. R. China .
    Mak, Wing Cheung
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    High efficiency single-step biomaterial-based microparticle fabrication via template-directed supramolecular coordination chemistry2016In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 18, no 6, p. 1715-1723Article in journal (Refereed)
    Abstract [en]

    Biomaterial-based microparticles have attracted much attention for medical and biological applications such as pharmaceutics, bioseparation and cosmetics. Emerging technologies enable versatile and facile fabrication of microparticles, with key features being purity, precise size control, mild preparation conditions and minimal processing. Here, an innovative approach combining template synthesis, biomolecule assembly and partial-purification within a single step for high efficiency fabrication of pure biomaterial-based microparticles is reported. This concept is based on facile co-precipitation of biomolecules within CaCO3 templates and simultaneous crosslinking of entrapped biomolecules via Ca2+ driven supramolecular coordination chemistry, followed by template removal. Carbohydrate (alginate) and proteins (casein and fresh milk) are used as models of biomolecules. The process driven by selective crosslinking automatically excludes non-specific materials from the template and thus provides the additional function of partial-purification, as demonstrated using highly complexed fresh milk. This green approach to fabrication of biomaterial-based microparticles offers three critical advantages (i) mild conditions to preserve the chemical and secondary structures of biomolecules; (ii) single processing step to facilitate scale-up production; and (iii) partial-purification without the need for upstream raw material purification. This innovative approach not only addresses fundamental issues in fabrication techniques, but also marks progress in energy and environmental conservation during manufacturing processes.

  • 23.
    Lazzaroni, R.
    et al.
    Service de Chimie des Matériaux Nouveaux, Département des Matériaux et Procédés, Université de Mons-Hainaut, Belgium.
    Brédas, J. L.
    Service de Chimie des Matériaux Nouveaux, Département des Matériaux et Procédés, Université de Mons-Hainaut, Belgium.
    Dannetun, Per
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Lögdlund, Michael
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Salaneck, William R
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Electronic structure of the aluminum/polythiophene interface: A joint experimental and theoretical study1991In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 43, no 1-2, p. 3323-3328Article in journal (Refereed)
    Abstract [en]

    Not Available.

  • 24.
    Li, Guowei
    et al.
    Max Planck Inst Chem Phys Solids, Germany.
    Fu, Chenguang
    Max Planck Inst Chem Phys Solids, Germany.
    Shi, Wujun
    ShanghaiTech Univ, Peoples R China.
    Jiao, Lin
    Max Planck Inst Chem Phys Solids, Germany.
    Wu, Jiquan
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Yang, Qun
    Max Planck Inst Chem Phys Solids, Germany.
    Saha, Rana
    Max Planck Inst Microstruct Phys, Germany.
    Kamminga, Machteld E.
    Univ Groningen, Netherlands.
    Srivastava, Abhay K.
    Max Planck Inst Microstruct Phys, Germany.
    Liu, Enke
    Max Planck Inst Chem Phys Solids, Germany.
    Yazdani, Aliza N.
    Carleton Coll, MN 55057 USA.
    Kumar, Nitesh
    Max Planck Inst Chem Phys Solids, Germany.
    Zhang, Jian
    Tech Univ Dresden, Germany.
    Blake, Graeme R.
    Univ Groningen, Netherlands.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wirth, Steffen
    Max Planck Inst Chem Phys Solids, Germany.
    Auffermann, Gudrun
    Max Planck Inst Chem Phys Solids, Germany.
    Gooth, Johannes
    Max Planck Inst Chem Phys Solids, Germany.
    Parkin, Stuart
    Max Planck Inst Microstruct Phys, Germany.
    Madhavan, Vidya
    Univ Illinois, IL 61801 USA; Univ Illinois, IL 61801 USA.
    Feng, Xinliang
    Tech Univ Dresden, Germany.
    Sun, Yan
    Max Planck Inst Chem Phys Solids, Germany.
    Felser, Claudia
    Max Planck Inst Chem Phys Solids, Germany.
    Dirac Nodal Arc Semimetal PtSn4: An Ideal Platform for Understanding Surface Properties and Catalysis for Hydrogen EvolutionIn: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773Article in journal (Refereed)
    Abstract [en]

    Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER). However, it is a challenge to combine these factors into a single compound. Herein, we discover a superior electrocatalyst for a HER in the recently identified Dirac nodal arc semimetal PtSn4. The determined turnover frequency (TOF) for each active site of PtSn4 is 1.54 H-2 s(-1) at 100 mV. This sets a benchmark for HER catalysis on Pt-based noble metals and earth-abundant metal catalysts. We make use of the robust surface states of PtSn4 as their electrons can be transferred to the adsorbed hydrogen atoms in the catalytic process more efficiently. In addition, PtSn4 displays excellent chemical and electrochemical stabilities after long-term exposure in air and long-time HER stability tests.

  • 25.
    Li, Sogjun
    et al.
    School of Materials Science & Engineering, Jiangsu University, Zhenjiang, China.
    Cao, ShunshengCranfield University, UK / Jiangsu University, Zhenjiang, China.Piletsky, SergeyBiotechnology Center, Cranfield University, UK.Turner, AnthonyLinköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Molecularly Imprinted Catalysts: principle, synthesis and applications2015Collection (editor) (Refereed)
    Abstract [en]

    Molecularly Imprinted Catalysts: Principle, Synthesis, and Applications is the first book of its kind to provide an in-depth overview of molecularly imprinted catalysts and selective catalysis, including technical details, principles of selective catalysis, preparation processes, the catalytically active polymers themselves, and important progress made in this field. It serves as an important reference for scientists, students, and researchers who are working in the areas of molecular imprinting, catalysis, molecular recognition, materials science, biotechnology, and nanotechnology.Comprising a diverse group of experts from prestigious universities and industries across the world, the contributors to this book provide access to the latest knowledge and eye-catching achievements in the field, and an understanding of what progress has been made and to what extent it is being advanced in industry.

  • 26.
    Li, Songjun
    et al.
    School of Materials Science & Engineering, Jiangsu University, Zhenjiang, China.
    Zhu, Maiyong
    School of Materials Science & Engineering, Jiangsu University, Zhenjiang, China.
    Whitcombe, Michael J.
    Department of Chemestry, Unversity of Leicester, UK.
    Piletsky, Sergey A.
    Department of Chemestry, Unversity of Leicester, UK.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Molecularly Imprinted Polymers for Enzyme-Like Catalysis: principle, design and applications2015In: Molecularly imprinted polymers for enzyme-like catalysis : principle, design and applications / [ed] Sogjun Li, Cao Shunsheng, Sergey Piletsky, Anthony Turner, Elsevier, 2015, p. 1-17Chapter in book (Refereed)
    Abstract [en]

    Selective catalysis remains a significant challenge owing to the lack of a generic protocol suitable for the preparation of selective catalytic materials. A promising approach is to translate the principle of enzyme catalysis for the design of new catalytic materials. Known as a “key-to-lock” technology, molecular imprinting provides a promising perspective by helping create in a straightforward manner binding sites that possess enzyme-like catalytic ability with but higher stability. In this chapter, we focus on discussing some key issues involved in active molecularly imprinted polymers from catalytic applications. The similarity and difference between preparing conventional molecularly imprinted polymers and catalytic imprinted polymers are highlighted. Other aspects relating to the principle, design, and future outlook of catalytic molecularly imprinted polymers are also discussed.

  • 27.
    Luszczynska, B.
    et al.
    Lodz Univ Technol, Poland.
    Akkuratov, A. V
    Russian Acad Sci, Russia.
    Szymanski, Marek
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Susarova, D. K.
    Russian Acad Sci, Russia.
    Dupont, B. G. R.
    Lodz Univ Technol, Poland.
    Babenko, S. D.
    Russian Acad Sci, Russia.
    Inasaridze, L. N.
    Russian Acad Sci, Russia.
    Bujak, P.
    Warsaw Univ Technol, Poland.
    Troshin, P. A.
    Lodz Univ Technol, Poland; Skolkovo Innovat Ctr, Russia.
    Ulanski, J.
    Lodz Univ Technol, Poland.
    New copolymers with fluorinated and non-fluorinated benzothiadiazole units for efficient single layer near infra-red photodiodes with fast time response2018In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 243, p. 67-74Article in journal (Refereed)
    Abstract [en]

    We describe the synthesis and photodetecting properties of new, low band-gap copolymers: P1 with 5,6-difluoro-2,1,3-benzothiadiazole and P2 with 2,1,3-benzothiadiazole, both containing diketopyrrolopyrrole acceptor units. These compounds have been used for fabrication of single layer, solution processed photodetectors. For this purpose, two blends with fullerene derivative (6,6)-phenyl-C61-butyric acid methyl ester ([60]PCBM): P1: [60]PCBM and P2:[60]PCBM, were prepared and applied as active layers in bulk-heterojunction photodiodes. For near infrared light (810 nm), these photodetectors, in spite of single layer structure, display competitive performance, showing specific detectivity up to 5.10(11) Jones, responsivity up to 0.3 A/W and rise and fall times of the transient signals below 10 mu s.

  • 28.
    Nilsson, David
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    An Organic Electrochemical Transistor for Printed Sensors and Logic2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Conducting polymers entered the research field in late 70´s and efforts aimed at achieving printed electronics started a decade later. This thesis treats printable organic electrochemical transistors (OECT). Some conjugated polymers can be switched between a high conducting and a low conducting state in an electrochemical cell. In this thesis, the work carried out using poly(3,4-ethylenedioxythiophene) (PEDOT) as the active material in an electrochemical transistor is reported. The electrochemical transistors, presented, can be designed into a bi-stable and dynamic mode of operation. These transistors operates at voltages below 2V and current on/off ratios are typically 5000, but 105 have been reached. The transistor device can be built up from all-organic materials using common printing techniques such as with screen-printing. The bi-stable transistor can be combined with an electrochromic (EC) display cell to form a smart pixel circuit. Combining several of these smart pixels yield an actively addressed cross-point matrix display. From this an all-organic active matrix display printable on paper has been achieved. The OECT, combined with a resistor network was successfully used in inverter and logic circuits.

    One important feature of these organic electrochemical devices is that both ions and electrons are used as the charge (signal) carriers. This is of particular interest and importance for chemical sensors. By combining a proton-conducting electrolyte (Nafion®) that changes its conductivity upon exposure to humidity, a simple OECT humidity sensor was achieved. This proves the use of this OECT as the ion-to-electron transducer.

    List of papers
    1. Bi-stable and dynamic current modulation in electrochemical organic transistors
    Open this publication in new window or tab >>Bi-stable and dynamic current modulation in electrochemical organic transistors
    Show others...
    2002 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 14, no 1, p. 51-54Article in journal (Refereed) Published
    Abstract [en]

    Novel electrochemical transistors, based on the conductive polymer PEDOT, operating at driving voltages of only a few volts in bulk material, and with little demand on substrate planarity, are described by the authors. The underlying polymer ion pair PEDOT:PSS is conductive in both oxidized and reduced state. Two transistor architectures, a bi-stable and a dynamic transistor (the first electrochemical specimen of its kind) with an on/off ratio of 105 and 200 Hz modulation speed, were realized.

    Keywords
    Conductivity, Polymer films, Transistors
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-13560 (URN)10.1002/1521-4095(20020104)14:1<51::AID-ADMA51>3.0.CO;2-# (DOI)
    Available from: 2008-11-12 Created: 2008-11-12 Last updated: 2017-12-13
    2. An all-organic sensor-transistor based on a novel electrochemical transducer concept printed electrochemical sensors on paper
    Open this publication in new window or tab >>An all-organic sensor-transistor based on a novel electrochemical transducer concept printed electrochemical sensors on paper
    2002 (English)In: Sensors and Actuators B: Chemical, ISSN 0925-4005, Vol. 86, no 2-3, p. 193-197Article in journal (Refereed) Published
    Abstract [en]

    A novel transducer concept based on an organic electrochemical transistor is described. Its function as an integral part of an air humidity sensor, in which the proton conductor Nafion acts as sensitivity layer has been realised. The resulting electrochemical sensor–transistor, based on the conducting polymer PEDOT:PSS, operates at low voltages, on the order of 1 V. The sensor response, measured as the drain–source current of the electrochemical transistor, versus air humidity, has a close to exponential behaviour. The sensor can be realised using exclusively printing and coating fabrication techniques. Here, we demonstrate devices realised on plastic foils and on ordinary coated fine paper substrates. This organic electrochemical transducer promise future applications such as all-integrated low-cost sensor tags for single-use chemical sensors.

    Keywords
    Organic transistors, Electrochemistry, Nafion, Proton conductors, Printing
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-13561 (URN)10.1016/S0925-4005(02)00170-3 (DOI)
    Available from: 2005-03-10 Created: 2005-03-10 Last updated: 2017-02-03
    3. Active Matrix Displays Based on All-Organic Electrochemical Smart Pixels Printed on Paper
    Open this publication in new window or tab >>Active Matrix Displays Based on All-Organic Electrochemical Smart Pixels Printed on Paper
    Show others...
    2002 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 14, no 20, p. 1460-1464Article in journal (Refereed) Published
    Abstract [en]

    An organic electronic paper display technology (see Figure and also inside front cover) is presented. The electrochromic display cell together with the addressing electrochemical transistor form simple smart pixels that are included in matrix displays, which are achieved on coated cellulose-based paper using printing techniques. The ion-electronic technology presented offers an opportunity to extend existing use of ordinary paper.

     

    Place, publisher, year, edition, pages
    Weinheim, Germany: Wiley-VCH Verlagsgesellschaft, 2002
    Keywords
    Displays, active matrix, Electronic paper, Poly(3, 4-ethylenedioxythiophene) (PEDOT), Polystyrene sulfonate (PSS)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-12763 (URN)10.1002/1521-4095(20021016)14:20<1460::AID-ADMA1460>3.0.CO;2-S (DOI)000179034200004 ()
    Available from: 2008-11-12 Created: 2008-11-12 Last updated: 2017-12-14Bibliographically approved
    4. Electrochemical Logic Circuits
    Open this publication in new window or tab >>Electrochemical Logic Circuits
    2005 (English)In: Advanced Materials, ISSN 0935-9648, Vol. 17, no 3, p. 353-358Article in journal (Refereed) Published
    Keywords
    Logic gates, organic, Transistors, electrochemical
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-13563 (URN)10.1002/adma.200401273 (DOI)
    Available from: 2008-11-12 Created: 2008-11-12 Last updated: 2017-02-03
  • 29.
    Nilsson, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, The Institute of Technology.
    Design, Synthesis and Characterization of Small Molecule Inhibitors and Small Molecule: Peptide Conjugates as Protein Actors2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes different aspects of protein interactions. Initially the function of peptides and their conjugates with small molecule inhibitors on the surface of Human Carbonic Anhydrase isoenzyme II (HCAII) is evaluated.

    The affinities for HCAII of the flexible, synthetic helix-loop-helix motif conjugated with a series of spacered inhibitors were measured by fluorescence spectroscopy and found in the best cases to be in the low nM range. Dissociation constants show considerable dependence on linker length and vary from 3000 nM for the shortest spacer to 40 nM for the longest with a minimum of 5 nM for a spacer with an intermediate length. A rationale for binding differences based on cooperativity is presented and supported by affinities as determined by fluorescence spectroscopy. Heteronuclear Single Quantum Correlation Nuclear Magnetic Resonance (HSQC) spectroscopic experiments with 15N-labeled HCAII were used for the determination of the site of interaction.

    The influence of peptide charge and hydrophobicity was evaluated by surface plasmon resonance experiments. Hydrophobic sidechain branching and, more pronounced, peptide charge was demonstrated to modulate peptide – HCAII binding interactions in a cooperative manner, with affinities spanning almost two orders of magnitude.

    Detailed synthesis of small molecule inhibitors in a general lead discovery library as well as a targeted library for inhibition of α-thrombin is described. For the lead discovery library 160 members emanate from two N4-aryl-piperazine-2-carboxylic acid scaffolds derivatized in two dimensions employing a combinatorial approach on solid support.

    The targeted library was based on peptidomimetics of the D-Phe-Pro-Arg showing the scaffolds cyclopropane-1R,2R-dicarboxylic acid and (4-amino-3-oxo-morpholin-2-yl)- acetic acid as proline isosters. Employing 4-aminomethyl-benzamidine as arginine mimic and different hydrophobic amines and electrophiles as D-phenylalanine mimics resulted in 34 compounds showing IC50 values for α-thrombin ranging more than three orders of magnitude with the best inhibitor showing an IC50 of 130 nM. Interestingly, the best inhibitors showed reversed stereochemistry in comparison with a previously reported series employing a 3-oxo-morpholin-2-yl-acetic acid scaffold.

    List of papers
    1. The binding of human Carbonic Anhydrase II by functionalized folded polypeptide receptors
    Open this publication in new window or tab >>The binding of human Carbonic Anhydrase II by functionalized folded polypeptide receptors
    Show others...
    2005 (English)In: Chemistry and Biology, ISSN 1074-5521, E-ISSN 1879-1301, Vol. 12, no 11, p. 1245-1252Article in journal (Refereed) Published
    Abstract [en]

    Several receptors for human carbonic anhydrase II (HCAII) have been prepared by covalently attaching benzenesulfonamide carboxylates via aliphatic aminocarboxylic acid spacers of variable length to the side chain of a lysine residue in a designed 42 residue helix-loop-helix motif. The sulfonamide group binds to the active site zinc ion of human carbonic anhydrase II located in a 15 Å deep cleft. The dissociation constants of the receptor-HCAII complexes were found to be in the range from low micromolar to better than 20 nM, with the lowest affinities found for spacers with less than five methylene groups and the highest affinity found for the spacer with seven methylene groups. The results suggest that the binding is a cooperative event in which both the sulfonamide residue and the helix-loop-helix motif contribute to the overall affinity.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13359 (URN)10.1016/j.chembiol.2005.08.018 (DOI)
    Available from: 2005-09-21 Created: 2005-09-21 Last updated: 2017-12-13
    2. Electrostatic and hydrophobic contributions to protein: peptide surface interactions
    Open this publication in new window or tab >>Electrostatic and hydrophobic contributions to protein: peptide surface interactions
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-13360 (URN)
    Available from: 2005-09-21 Created: 2005-09-21 Last updated: 2010-01-13
    3. Solid-phase synthesis of libraries generated from a 4-phenyl-2-carboxy-piperazine Scaffold
    Open this publication in new window or tab >>Solid-phase synthesis of libraries generated from a 4-phenyl-2-carboxy-piperazine Scaffold
    Show others...
    2001 (English)In: Journal of Combinatorial Chemistry, ISSN 2156-8952, Vol. 3, no 6, p. 546-553Article in journal (Refereed) Published
    Abstract [en]

    Strategies for finding novel structures of therapeutical interest are discussed. The rationale for the selection of the two scaffolds N4-(m-aminophenyl)-piperazine-2-carboxylic acid E and N4-(o-aminophenyl)-piperazine-2-carboxylic F is described. The synthesis of the appropriate precursors to scaffold E and F and their use in solid-phase chemistry are described. A 160-member library was produced combining these novel piperazine scaffolds with eight sulfonyl chlorides/acid chlorides and 10 amines. The compound library prepared was analyzed using LC-MS, showing the expected base peak in all wells at an average purity of 82%.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2001
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13467 (URN)10.1021/cc010013o (DOI)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2018-05-21
    4. Synthesis and SAR of Thrombin Inhibitors Incorporating a Novel 4-Amino-Morpholinone Scaffold: Analysis of X-ray Crystal Structure of Enzyme Inhibitor Complex
    Open this publication in new window or tab >>Synthesis and SAR of Thrombin Inhibitors Incorporating a Novel 4-Amino-Morpholinone Scaffold: Analysis of X-ray Crystal Structure of Enzyme Inhibitor Complex
    Show others...
    2001 (English)In: Journal of Medicinal Chemistry, ISSN 0022-2623, Vol. 46, no 19, p. 3985-4001Article in journal (Refereed) Published
    Abstract [en]

    A 4-amino-2-carboxymethyl-3-morpholinone structural motif derived from malic acid has been used to mimic d-Phe-Pro in the thrombin inhibiting tripeptide d-Phe-Pro-Arg. The arginine in d-Phe-Pro-Arg was replaced by the more rigid P1 truncated p-amidinobenzylamine (Pab). These new thrombin inhibitors were used to probe the inhibitor binding site of α-thrombin. The best candidate in this series of thrombin inhibitors exhibits an in vitro IC50 of 0.130 μM. Interestingly, the stereochemistry of the 4-amino-2-carboxymethyl-3-morpholinone motif is reversed for the most active compounds compared to that of a previously reported 2-carboxymethyl-3-morpholinone series. The X-ray crystal structure of the lead inhibitor cocrystallized with α-thrombin is discussed.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13362 (URN)10.1021/jm0307990 (DOI)
    Available from: 2005-09-21 Created: 2005-09-21 Last updated: 2009-05-28
  • 30.
    Nygren, Patrik
    Linköping University, The Department of Physics, Chemistry and Biology.
    Bioorganisk fastfas syntes för att skapa intelligenta ytor2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    This thesis investigates three different surface modifications, and the route to design and synthesize them. The thesis is therefore divided into three sub- projects. (i.) Design and synthesis of a peptide which secondary structure could be controlled by a negatively charged surface. (ii.) Design and synthesis of a cyclic peptide, that would self-organize prior to surface interaction, using the type I anti-freeze protein of a winter flounder as template. (iii.) The use of solid-phase synthesis to make the synthesis of SAM-molecules easier.

  • 31.
    Nygren, Patrik
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    De Novo Design and Characterization of Surface Binding Peptides - Steps toward Functional Surfaces2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The ability to create surfaces with well-defined chemical properties is a major research field. One possibility to do this is to design peptides that bind with a specific secondary structure to silica nanoparticles. The peptides discussed in this thesis are constructed to be random coil in solution, but are “forced” to become helical when adsorbed to the particles. The positively charged side-chains on the peptides strongly disfavor an ordered structure in solution due to electrostatic repulsion. When the peptides are introduced to the particles these charges will strongly favor the structure because of ion pair bonding between the peptide and the negatively charged nanoparticles. The peptide-nanoparticle system has been thoroughly investigated by systematic variations of the side-chains. In order to determine which factors that contributes to the induced structure, several peptides with different amino acid sequences have been synthesized. Factors that have been investigated include 1) the positive charge density, 2) distribution of positive charges, 3) negative charge density, 4) increasing hydrophobicity, 5) peptide length, and 6) by incorporating amino acids with different helix propensities. Moreover, pH dependence and the effect of different nanoparticle curvature have also been investigated. It will also be shown that the system can be modified to incorporate a catalytic site that is only active when the helix is formed. This research will increase our understanding of peptide-surface interactions and might be of importance for both nanotechnology and medicine.

    List of papers
    1. Induction of structure and function in a designed peptide upon adsorption on a silica nanoparticle
    Open this publication in new window or tab >>Induction of structure and function in a designed peptide upon adsorption on a silica nanoparticle
    2006 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 45, no 48, p. 8169-8173Article in journal (Refereed) Published
    Abstract [en]

    No abstrack available.

    Keywords
    Amino acids, catalysis, helical structures, nanoparticles, peptides
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-14548 (URN)10.1002/anie.200600965 (DOI)
    Available from: 2008-02-25 Created: 2008-02-25 Last updated: 2017-12-13Bibliographically approved
    2. Optimizing Nanoparticle Induced Helical Structure in a De Novo Designed Peptide by Rational Changes in Amino Acid Sequence
    Open this publication in new window or tab >>Optimizing Nanoparticle Induced Helical Structure in a De Novo Designed Peptide by Rational Changes in Amino Acid Sequence
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14549 (URN)
    Available from: 2008-02-25 Created: 2008-02-25 Last updated: 2010-01-13
  • 32.
    Okabayashi, Yohei
    Linköping University, Department of Physics, Chemistry and Biology.
    Synthesis of azide- and alkyne-terminated alkane thiols and evaluation of their application in Huisgen 1,3-dipolar cycloaddition ("click") reactions on gold surfaces2009Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Immobilization of different bio- and organic molecules on solid supports is fundamental within many areas of science. Sometimes, it is desirable to obtain a directed orientation of the molecule in the immobilized state. In this thesis, the copper (I) catalyzed Huisgen 1,3-dipolar cycloaddition, referred to as a “click chemistry” reaction, was explored as a means to perform directed immobilization of small molecule ligands on gold surfaces. The aim was to synthesize alkyne- and azide-terminated alkanethiols that would form well-organized self assembled monolayers (SAMs) on gold from the commercially available substances orthoethylene glycol and bromo alkanoic acid. N-(23-azido-3,6,9,12,15,18,21-heptaoxatricosyl)-n-mercaptododekanamide/hexadecaneamide (n = 12, 16) were successfully synthesized and allowed to form SAMs of different compositions to study how the differences in density of the functional groups on the surface would influence the structure of the monolayer and the click chemistry reaction. The surfaces were characterized by different optical methods: ellipsometry, contact angle goniometry and infrared reflection-absorption spectroscopy (IRAS). The click reaction was found to proceed at very high yields on all investigated surfaces. Finally, the biomolecular interaction between a ligand immobilized by click chemistry on the gold surfaces and a model protein (bovine carbonic anhydrase) was demonstrated by surface plasmon resonance using a Biacore system.

  • 33.
    Oruganti, Baswanth
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Computational Design of Molecular Motors and Excited-State Studies of Organic Chromophores2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents computational quantum chemical studies of molecular motors and excited electronic states of organic chromophores.

    The first and major part of the thesis is concerned with the design of light-driven rotary molecular motors. These are molecules that absorb light energy and convert it into 360° unidirectional rotary motion around a double bond connecting two molecular halves. In order to facilitate potential applications of molecular motors in nanotechnology, such as in molecular transport or in development of materials with photo-controllable properties, it is critical to optimize the rates and efficiencies of the chemical reactions that produce the rotary motion. To this end, computational methods are in this thesis used to study two different classes of molecular motors.

    The first class encompasses the sterically overcrowded alkenes developed by Ben Feringa, co-recipient of the 2016 Nobel Prize in Chemistry. The rotary cycles of these motors involve two photoisomerization and two thermal isomerization steps, where the latter are the ones that limit the attainable rotational frequencies. In the thesis, several new motors of this type are proposed by identifying steric, electronic and conformational approaches to accelerate the thermal isomerizations. The second class contains motors that incorporate a protonated Schiff base and are capable to achieve higher photoisomerization rates than overcrowded alkene-based motors. In the thesis, a new motor of this type is proposed that produces unidirectional rotary motion by means of two photochemical steps alone. Also, this motor lacks both a stereocenter and helical motifs, which are key features of almost all synthetic rotary motors developed to date.

    The second part of the thesis focuses on the design and assessment of composite computational procedures for modeling excited electronic states of organic chromophores. In particular, emphasis is put on developing procedures that facilitate the calculations of accurate 0−0 excitation energies of such compounds in a cost-effective way by combining quantum chemical methods with different accuracies.

    List of papers
    1. Computational study of the working mechanism and rate acceleration of overcrowded alkene-based light-driven rotary molecular motors
    Open this publication in new window or tab >>Computational study of the working mechanism and rate acceleration of overcrowded alkene-based light-driven rotary molecular motors
    2014 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 20, p. 10240-10251Article in journal (Refereed) Published
    Abstract [en]

    In recent years, much progress has been made in the design, synthesis and operation of light-driven rotary molecular motors based on chiral overcrowded alkenes. Through consecutive cistrans photoisomerization and thermal helix inversion steps, where the latter dictate the overall rate of rotation, these motors achieve a full 360° unidirectional rotation around the carbon–carbon double bond connecting the two (rotator and stator) alkene halves. In this work, we report quantum chemical calculations indicating that a particularly fast-rotating overcrowded alkene-based motor capable of reaching the MHz regime, can be made to rotate even faster by the substitution of a rotator methyl group with a methoxy group. Specifically, using density functional theory methods that reproduce the rate-limiting 35 kJ mol−1 thermal free-energy barriers shown by the methyl-bearing motor with errors of 5 kJ mol−1 only, it is predicted that this substitution reduces these barriers by a significant 15–20 kJ mol−1. This prediction is preceded by a series of benchmark calculations for assessing how well density functional theory methods account for available experimental data (crystallographic, UV-vis absorption, thermodynamic) on the rotary cycles of overcrowded alkenes, and a detailed examination of the thermal and photochemical reaction mechanisms of the original motor of this type.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2014
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-104688 (URN)10.1039/C3RA46880A (DOI)000332061300048 ()2-s2.0-84894247198 (Scopus ID)
    Available from: 2014-02-22 Created: 2014-02-22 Last updated: 2017-12-05Bibliographically approved
    2. Computational design of faster rotating second-generation light-driven molecular motors by control of steric effects
    Open this publication in new window or tab >>Computational design of faster rotating second-generation light-driven molecular motors by control of steric effects
    2015 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 33, p. 21740-21751Article in journal (Refereed) Published
    Abstract [en]

    We report a systematic computational investigation of the possibility to accelerate the rate-limiting thermal isomerizations of the rotary cycles of synthetic light-driven overcrowded alkene-based molecular motors through modulation of steric interactions. Choosing as a reference system a second-generation motor known to accomplish rotary motion in the MHz regime and using density functional theory methods, we propose a three-step mechanism for the thermal isomerizations of this motor and show that variation of the steric bulkiness of the substituent at the stereocenter can reduce the (already small) free-energy barrier of the rate-determining step by a further 15-17 kJ mol(-1). This finding holds promise for future motors of this kind to reach beyond the MHz regime. Furthermore, we demonstrate and explain why one particular step is kinetically favored by decreasing and another step is kinetically favored by increasing the steric bulkiness of this substituent, and identify a possible back reaction capable of impeding the rotary rate.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2015
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-121153 (URN)10.1039/c5cp02303c (DOI)000359596600080 ()26234787 (PubMedID)
    Note

    Funding Agencies|Linkoping University; Swedish Research Council; Olle Engkvist Foundation; Wenner-Gren Foundations; NSFC [11404141]; National Supercomputer Centre (NSC) in Linkoping

    Available from: 2015-09-08 Created: 2015-09-08 Last updated: 2018-03-22
    3. On the possibility to accelerate the thermal isomerizations of overcrowded alkene-based rotary molecular motors with electron-donating or electron-withdrawing substituents
    Open this publication in new window or tab >>On the possibility to accelerate the thermal isomerizations of overcrowded alkene-based rotary molecular motors with electron-donating or electron-withdrawing substituents
    2016 (English)In: Journal of Molecular Modeling, ISSN 1610-2940, E-ISSN 0948-5023, Vol. 22, no 9, p. 219-Article in journal (Refereed) Published
    Abstract [en]

    We employ computational methods to investigate the possibility of using electron-donating or electron-withdrawing substituents to reduce the free-energy barriers of the thermal isomerizations that limit the rotational frequencies achievable by synthetic overcrowded alkene-based molecular motors. Choosing as reference systems one of the fastest motors known to date and two variants thereof, we consider six new motors obtained by introducing electron-donating methoxy and dimethylamino or electron-withdrawing nitro and cyano substituents in conjugation with the central olefinic bond connecting the two (stator and rotator) motor halves. Performing density functional theory calculations, we then show that electron-donating (but not electron-withdrawing) groups at the stator are able to reduce the already small barriers of the reference motors by up to 18 kJ mol(-1). This result outlines a possible strategy for improving the rotational frequencies of motors of this kind. Furthermore, exploring the origin of the catalytic effect, it is found that electron-donating groups exert a favorable steric influence on the thermal isomerizations, which is not manifested by electron-withdrawing groups. This finding suggests a new mechanism for controlling the critical steric interactions of these motors.

    Place, publisher, year, edition, pages
    SPRINGER, 2016
    Keywords
    Electronic effects; Molecular motors; Quantum chemistry; Rotary rates; Steric effects
    National Category
    Theoretical Chemistry
    Identifiers
    urn:nbn:se:liu:diva-131672 (URN)10.1007/s00894-016-3085-y (DOI)000382748100024 ()27553304 (PubMedID)
    Note

    Funding Agencies|Linkoping University; Swedish Research Council [621-2011-4353]; Olle Engkvist Foundation; Carl Trygger Foundation

    Available from: 2016-10-03 Created: 2016-09-30 Last updated: 2017-11-30
    4. Computational Insight to Improve the Thermal Isomerisation Performance of Overcrowded Alkene-Based Molecular Motors through Structural Redesign
    Open this publication in new window or tab >>Computational Insight to Improve the Thermal Isomerisation Performance of Overcrowded Alkene-Based Molecular Motors through Structural Redesign
    2016 (English)In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 17, no 21, p. 3399-3408Article in journal (Refereed) Published
    Abstract [en]

    Synthetic overcrowded alkene-based molecular motors achieve 360° unidirectional rotary motion of one motor half (rotator) relative to the other (stator) through sequential photochemical and thermal isomerisation steps. In order to facilitate and expand the use of these motors for various applications, it is important to investigate ways to increase the rates and efficiencies of the reactions governing the rotary motion. Here, we use computational methods to explore whether the thermal isomerisation performance of some of the fastest available motors of this type can be further improved by reducing the sizes of the motor halves. Presenting three new redesigned motors that combine an indanylidene rotator with a cyclohexadiene, pyran or thiopyran stator, we first use multiconfigurational quantum chemical methods to verify that the photoisomerisations of these motors sustain unidirectional rotary motion. Then, by performing density functional calculations, we identify both stepwise and concerted mechanisms for the thermal isomerisations of the motors and show that the rate-determining free-energy barriers of these processes are up to 25 kJ mol−1 smaller than those of the original motors. Furthermore, the thermal isomerisations of the redesigned motors proceed in fewer steps. Altogether, the results suggest that the redesigned motors are useful templates for improving the thermal isomerisation performance of existing overcrowded alkene-based motors.

    Place, publisher, year, edition, pages
    Wiley-Blackwell Publishing Inc., 2016
    Keywords
    Density functional calculations, isomerisation, molecular motors, rotary rates, stepwise versus concerted mechanisms
    National Category
    Theoretical Chemistry Materials Chemistry Chemical Engineering
    Identifiers
    urn:nbn:se:liu:diva-132609 (URN)10.1002/cphc.201600766 (DOI)000388629200011 ()27550708 (PubMedID)
    Note

    Funding agencies: Swedish Research Council [621-2011-4353]; Olle Engkvist Foundation [2014/734]; Carl Trygger Foundation [CTS 15:134]; Linkoping University

    Available from: 2016-11-16 Created: 2016-11-16 Last updated: 2017-11-29Bibliographically approved
    5. How method-dependent are calculated differences between vertical, adiabatic, and 0-0 excitation energies?
    Open this publication in new window or tab >>How method-dependent are calculated differences between vertical, adiabatic, and 0-0 excitation energies?
    2014 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 118, no 23, p. 4157-4171Article in journal (Refereed) Published
    Abstract [en]

    Through a large number of benchmark studies, the performance of different quantum chemical methods in calculating vertical excitation energies is today quite well established. Furthermore, these efforts have in recent years been complemented by a few benchmarks focusing instead on adiabatic excitation energies. However, it is much less well established how calculated differences between vertical, adiabatic and 0-0 excitation energies vary between methods, which may be due to the cost of evaluating zero-point vibrational energy corrections for excited states. To fill this gap, we have calculated vertical, adiabatic, and 0-0 excitation energies for a benchmark set of molecules covering both organic and inorganic systems. Considering in total 96 excited states and using both TD-DFT with a variety of exchange-correlation functionals and the ab initio CIS and CC2 methods, it is found that while the vertical excitation energies obtained with the various methods show an average (over the 96 states) standard deviation of 0.39 eV, the corresponding standard deviations for the differences between vertical, adiabatic, and 0-0 excitation energies are much smaller: 0.10 (difference between adiabatic and vertical) and 0.02 eV (difference between 0-0 and adiabatic). These results provide a quantitative measure showing that the calculation of such quantities in photochemical modeling is well amenable to low-level methods. In addition, we also report on how these energy differences vary between chemical systems and assess the performance of TD-DFT, CIS, and CC2 in reproducing experimental 0-0 excitation energies.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2014
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-109132 (URN)10.1021/jp501974p (DOI)000337497300017 ()24848558 (PubMedID)
    Available from: 2014-08-13 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
    6. Assessment of a composite CC2/DFT procedure for calculating 0-€“0 excitation energies of organic molecules
    Open this publication in new window or tab >>Assessment of a composite CC2/DFT procedure for calculating 0-€“0 excitation energies of organic molecules
    2016 (English)In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 114, no 23, p. 3448-3463Article in journal (Refereed) Published
    Abstract [en]

    The task to assess the performance of quantum chemical methods in describing electronically excited states has in recent years started to shift from calculation of vertical (ΔEve) to calculation of 0-€“0 excitation energies (ΔE00). Here, based on a set of 66 excited states of organic molecules for which high-resolution experimental ΔE00 energies are available and for which the approximate coupled-cluster singles and doubles (CC2) method performs particularly well, we explore the possibility to simplify the calculation of CC2-quality ΔE00 energies using composite procedures that partly replace CC2 with more economical methods. Specifically, we consider procedures that employ CC2 only for the ΔEve part and density functional theory methods for the cumbersome excited-state geometry optimisations and frequency calculations required to obtain ΔE00 energies from ΔEve ones. The results demonstrate that it is indeed possible to both closely (to within 0.06-€“0.08 eV) and consistently approximate ‘true’ CC2 ΔE00 energies in this way, especially when CC2 is combined with hybrid density functionals. Overall, the study highlights the unexploited potential of composite procedures, which hitherto have found widespread use mostly in ground-state chemistry, to also play an important role in facilitating accurate studies of excited states.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2016
    National Category
    Theoretical Chemistry Atom and Molecular Physics and Optics Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-132610 (URN)10.1080/00268976.2016.1235736 (DOI)000390851000004 ()
    Note

    Funding agencies: Swedish Research Council [621-2011-4353]; Olle Engkvist Foundation [2014/734]; Carl Trygger Foundation [CTS 15:134]; Wenner-Gren Foundations; Linkoping University

    Available from: 2016-11-16 Created: 2016-11-16 Last updated: 2018-03-19Bibliographically approved
  • 34.
    Oruganti, Baswanth
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Wang, Jun
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Durbeej, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Excited-State Aromaticity Improves Molecular Motors: A Computational Analysis2017In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 19, no 18, p. 4818-4821Article in journal (Refereed)
    Abstract [en]

    A new approach to the design of more efficient light-driven rotary molecular motors is presented and evaluated computationally based on molecular dynamics simulations. The approach involves enabling part of the motor to become aromatic in the photoactive excited state, and is found to sharply increase the rotary quantum yields of the photoisomerizations that underlie the motor function. Excited-state aromaticity thus holds promise as a guiding principle toward better-performing molecular motors.

  • 35.
    Paintner, Tobias
    et al.
    Tech Univ Munich, Germany.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Du, Ping
    Karlsruhe Inst Technol, Germany.
    Klyatskaya, Svetlana
    Karlsruhe Inst Technol, Germany.
    Paszkiewicz, Mateusz
    Tech Univ Munich, Germany.
    Hellwig, Raphael
    Tech Univ Munich, Germany.
    Uphoff, Martin
    Tech Univ Munich, Germany.
    Oener, Murat A.
    Tech Univ Munich, Germany.
    Cuniberto, Edoardo
    Tech Univ Munich, Germany.
    Deimel, Peter S.
    Tech Univ Munich, Germany.
    Zhang, Yi-Qi
    Tech Univ Munich, Germany.
    Palma, Carlos-Andres
    Tech Univ Munich, Germany; Chinese Acad Sci, Peoples R China.
    Allegretti, Francesco
    Tech Univ Munich, Germany.
    Ruben, Mario
    Karlsruhe Inst Technol, Germany; Univ Strasbourg, France.
    Barth, Johannes V
    Tech Univ Munich, Germany.
    Klappenberger, Florian
    Tech Univ Munich, Germany.
    Quantum Tunneling Mediated Interfacial Synthesis of a Benzofuran Derivative2019In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 58, no 33, p. 11285-11290Article in journal (Refereed)
    Abstract [en]

    Reaction pathways involving quantum tunneling of protons are fundamental to chemistry and biology. They are responsible for essential aspects of interstellar synthesis, the degradation and isomerization of compounds, enzymatic activity, and protein dynamics. On-surface conditions have been demonstrated to open alternative routes for organic synthesis, often with intricate transformations not accessible in solution. Here, we investigate a hydroalkoxylation reaction of a molecular species adsorbed on a Ag(111) surface by scanning tunneling microscopy complemented by X-ray electron spectroscopy and density functional theory. The closure of the furan ring proceeds at low temperature (down to 150 K) and without detectable side reactions. We unravel a proton-tunneling-mediated pathway theoretically and confirm experimentally its dominant contribution through the kinetic isotope effect with the deuterated derivative.

  • 36.
    Palma, Carlos-Andres
    et al.
    Technishe Universität München, Garching, Germany.
    Diller, Katharina
    Technishe Universität München, Garching, Germany.
    Berger, Reinhard
    Max-Planck-Institut für Polymerforschung, Mainz, Germany.
    Welle, Alexander
    Karlsruher Institut für Technologie, Eggenstein-Leopoldshafen, Germany.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Cabellos, Jose Luis Cabellos
    Universidad del País Vasco UPV/EHU, San Sebastián, Spain.
    Mowbray, Duncan John
    Universidad del País Vasco UPV/EHU, San Sebastián, Spain.
    Papageorgiou, Anthoula C.
    Technishe Universität München, Garching, Germany.
    Ivleva, Natalia P.
    Technische Universität München, München, Germany.
    Matich, Sonja
    Walter Schottky Institut, Garching, Germany.
    Margapoti, Emanuela
    Walter Schottky Institut, Garching, Germany.
    Niesser, Reinhard
    Technische Universität München, Germany.
    Menges, Bernhard
    Max-Planck-Institut für Polymerforschung, Mainz, Germany.
    Reichert, Joachim
    Technishe Universität München, Garching, Germany.
    Feng, Xinliang
    Max-Planck-Institut für Polymerforschung, Mainz, Germany.
    Räder, Hans Joachim
    Max-Planck-Institut für Polymerforschung, Mainz, Germany.
    Klappenberger, Florian
    Technishe Universität München, Garching, Germany.
    Rubio, Angel
    Universidad del País Vasco UPV/EHU, San Sebastián, Spain.
    Müllen, Klaus
    Max-Planck-Institut für Polymerforschung, Mainz, Germany.
    Barth, Johannes V.
    Technishe Universität München, Garching, Germany.
    Photo-induced C-C reactions on insulators towards photolithography of graphene nanoarchitectures2014In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, p. 4651-4658Article in journal (Refereed)
    Abstract [en]

    On-surface chemistry for atomically precise sp2 macromolecules requires top-down lithographic methods on insulating surfaces in order to pattern the long-range complex architectures needed by the semiconductor industry. Here, we fabricate sp2-carbon nm-thin films on insulators and under ultra-high vacuum (UHV) conditions from photo-coupled brominated precursors. We reveal that covalent coupling is initiated by C-Br bond cleavage through photon energies exceeding 4.4 eV, as monitored by laser desorption ionization (LDI) mass spectrometry (MS) and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) gives insight into the mechanisms of C-Br scission and C-C coupling processes. Further, unreacted material can be sublimed and the coupled sp2-carbon precursors can be graphitized by e-beam treatment at 500°C, demonstrating promising applications in photolithography of graphene nanoarchitectures. Our results present UV-induced reactions on insulators for the formation of all sp2-carbon architectures, thereby converging top-down lithography and bottom-up on-surface chemistry into technology.

  • 37.
    Rivilla, Ivan
    et al.
    Department of Organic Chemistry I, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), Donostia/San Sebastián, Spain.
    de Cozar, Abel
    Department of Organic Chemistry I, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), Donostia/San Sebastián, Spain; Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
    Schafer, Thomas
    Ikerbasque, Basque Foundation for Science, Bilbao, Spain; NanoBioSeparations Group, POLYMAT University of the Basque Country (UPV/EHU), Donostia/San Sebastián, Spain.
    Hernandez, Frank J.
    NanoBioSeparations Group, POLYMAT University of the Basque Country (UPV/EHU), Avda. Tolosa 72, E-20018 Donostia/San Sebastián, Spain.
    Bittner, Alexander M.
    NanoBioSeparations Group, POLYMAT University of the Basque Country (UPV/EHU), Donostia/San Sebastián, Spain; CIC NanoGUNE, Donostia/San Sebastián, Spain.
    Eleta-Lopez, Aitziber
    CIC NanoGUNE, Donostia/San Sebastián, Spain.
    Aboudzadeh, Ali
    NanoBioSeparations Group, POLYMAT University of the Basque Country (UPV/EHU), Donostia/San Sebastián, Spain.
    Santos, Jose I.
    SGIker NMR Facility, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia/San Sebastián, Spain.
    Miranda, Jose I.
    SGIker NMR Facility, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia/San Sebastián, Spain.
    Cossio, Fernando P.
    Department of Organic Chemistry I, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), Donostia/San Sebastián, Spain .
    Catalysis of a 1,3-dipolar reaction by distorted DNA incorporating a heterobimetallic platinum(ii) and copper(ii) complex2017In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 8, no 10, p. 7038-7046Article in journal (Refereed)
    Abstract [en]

    A novel catalytic system based on covalently modified DNA is described. This catalyst promotes 1,3-dipolar reactions between azomethine ylides and maleimides. The catalytic system is based on the distortion of the double helix of DNA by means of the formation of Pt(ii) adducts with guanine units. This distortion, similar to that generated in the interaction of DNA with platinum chemotherapeutic drugs, generates active sites that can accommodate N-metallated azomethine ylides. The proposed reaction mechanism, based on QM(DFT)/MM calculations, is compatible with thermally allowed concerted (but asynchronous) [[small pi]4s + [small pi]2s] mechanisms leading to the exclusive formation of racemic endo-cycloadducts.

  • 38.
    Salinas, Borja Cirera
    et al.
    Technische Universität München, Garching, Germany.
    Zhang, Yi-Qi
    Technische Universität München, Garching, Germany.
    Björk, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Klyatskaya, Svetlana
    Karlsruhe Institute of Technology, Garching, Germany.
    Chen, Zhi
    Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
    Ruben, Mario
    Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
    Barth, Johannes V.
    Technische Universität München, Garching, Germany.
    Klappenberger, Florian
    Technische Universität München, Garching, Germany.
    Synthesis of Extended Graphdiyne Wires by Vicinal Surface Templating2014In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, no 4, p. 1891-1897Article in journal (Refereed)
    Abstract [en]

    Surface-assisted covalent synthesis currently evolves into an important approach for the fabrication of functional nanostructures at interfaces. Here, we employ scanning tunneling microscopy to investigate the homo-coupling reaction of linear, terminal alkyne-functionalized polyphenylene building-blocks on noble metal surfaces under ultra-high vacuum. On the flat Ag(111) surface thermal activation triggers a variety of side-reactions resulting in irregularly-branched polymeric networks. Upon alignment along the step-edges of the Ag(877) vicinal surface drastically improves the chemoselectivity of the linking process permitting the controlled synthesis of extended-graphdiyne wires with lengths reaching 30 nm. The ideal hydrocarbon scaffold is characterized by density functional theory as a 1D, direct band gap semiconductor material with both HOMO and LUMO-derived bands promisingly isolated within the electronic structure. The templating approach should be applicable to related organic precursors and different reaction schemes thus bears general promise for the engineering of novel low-dimensional carbon-based materials.

  • 39.
    Selvaraj, Karthik
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Mofers, Arjan
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Pellegrini, Paola
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Salomonsson, Johannes
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Ahlner, Alexandra
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Morad, Vivian
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Hillert, Ellin-Kristina
    Karolinska Inst, Sweden.
    Espinosa, Belen
    Karolinska Inst, Sweden.
    Arner, Elias S. J.
    Karolinska Inst, Sweden.
    Jensen, Lasse
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pharmacology.
    Malmstrom, Jonas
    Recipharm AB, Sweden.
    Turkina, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    D´arcy, Padraig
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Walters, Michael A.
    Univ Minnesota, MN 55455 USA.
    Sunnerhagen, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Linder, Stig
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. Karolinska Inst, Sweden.
    Cytotoxic unsaturated electrophilic compounds commonly target the ubiquitin proteasome system2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 9841Article in journal (Refereed)
    Abstract [en]

    A large number of natural products have been advocated as anticancer agents. Many of these compounds contain functional groups characterized by chemical reactivity. It is not clear whether distinct mechanisms of action can be attributed to such compounds. We used a chemical library screening approach to demonstrate that a substantial fraction (similar to 20%) of cytotoxic synthetic compounds containing Michael acceptor groups inhibit proteasome substrate processing and induce a cellular response characteristic of proteasome inhibition. Biochemical and structural analyses showed binding to and inhibition of proteasome-associated cysteine deubiquitinases, in particular ubiquitin specific peptidase 14 (USP14). The results suggested that compounds bind to a crevice close to the USP14 active site with modest affinity, followed by covalent binding. A subset of compounds was identified where cell death induction was closely associated with proteasome inhibition and that showed significant antineoplastic activity in a zebrafish embryo model. These findings suggest that proteasome inhibition is a relatively common mode of action by cytotoxic compounds containing Michael acceptor groups and help to explain previous reports on the antineoplastic effects of natural products containing such functional groups.

  • 40.
    Singh, Prem
    et al.
    Indian Inst Technol Mandi, India.
    Sonika,
    Indian Inst Technol Mandi, India.
    Gangadharan, Pranav K.
    CSIR Natl Chem Lab, India; Acad Sci and Innovat Res AcSIR, India.
    Khan, Ziyauddin
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kurungot, Sreekumar
    CSIR Natl Chem Lab, India; Acad Sci and Innovat Res AcSIR, India.
    Jaiswal, Amit
    Indian Inst Technol Mandi, India.
    Cubic Palladium Nanorattles with Solid Octahedron Gold Core for Catalysis and Alkaline Membrane Fuel Cell Applications2019In: ChemCatChem, ISSN 1867-3880, E-ISSN 1867-3899, Vol. 11, no 17, p. 4383-4392Article in journal (Refereed)
    Abstract [en]

    Herein, we report the synthesis of palladium nanorattles (Au-Pd NRTs) comprising of a gold octahedral core caged within a thin porous cubic palladium shell. The introduction of core-shell and porous architecture was realized by combining seed mediated and galvanic replacement reaction techniques. Next, we examined the catalytic efficiency of the nanocatalyst in comparison with solid palladium nanocube (Pd-NC) of similar size for the degradation of p-nitrophenol and organic dyes. The rate constant of Au-Pd NRTs was found nearly 12 times higher than the Pd-NCs. Further, we exploited our catalyst for electrochemical oxygen reduction reaction (ORR) and observed its high intrinsic ORR activity. Compared with commercialized Pt/C, the Au-Pd NRT displayed nearly comparable onset and half-wave potential values and excellent durability upon potential cycling. The system level validation in a single-cell mode of alkaline exchange membrane fuel cell also confirms the efficiency of the present catalyst to serve as a potential cathode catalyst for realistic device applications.

  • 41.
    Singh, Sandeep Kumar
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Oxygen Reduction Reaction in Conducting Polymer PEDOT: Density Functional Theory Study2017In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 22, p. 12270-12277Article in journal (Refereed)
    Abstract [en]

    An oxygen reduction reaction (ORR) mechanism in conducting polymer PEDOT is studied using the density functional theory. It is demonstrated that pure PEDOT chains possess the catalytic activity, where no platinum catalyst or external dopants are needed to sustain the electrocatalysis. This remarkable property of PEDOT is related to the formation of polaronic states, which leads to the decrease of the HOMO LUMO gap and thus to the enhancement of the reactivity of the system. It is shown that ORR on PEDOT chains can proceed via two pathways, whether via a four-electron process when the oxygen reacts with protons and is reduced directly into water in four steps (Reaction path I) or via the two-electron process leading to formation of the hydrogen peroxide as an intermediate specimen (Reaction path II). Path I is demonstrated to be energetically preferable. This conclusion also holds for ORR on two pi-pi stacked chains and ORR for the case when PEDOT is reduced during the reaction. It is also found that ORR on PEDOT effectively proceeds in the presence of H3O+ but does not occur in the absence of acidic environment.

  • 42.
    Sjöqvist, Jonas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    González-Cano, Rafael C.
    University of Málaga, Spain.
    López Navarette, Juan T.
    University of Málaga, Spain.
    Casado, Juan
    University of Málaga, Spain.
    Ruiz Delgado, M. Carmen
    University of Málaga, Spain.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    A combined MD/QM and experimental exploration of conformational richness in branched oligothiophenes2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 45, p. 24841-24852Article in journal (Refereed)
    Abstract [en]

    Infrared (IR) absorption and vibrational Raman spectra of a family of branched oligothiophenes have been determined experimentally as well as theoretically. The molecular spectra have been compared to those of the linear analogues, with identification made of spectral features due to structural properties that are valued in organic solar cell applications. The theoretical spectra have been obtained through a newly developed method in which individual conformer spectra, calculated at the time-dependent DFT level in this work, are weighted by statistics extracted from classical molecular dynamics trajectories. The agreement with experiment for the resulting averaged spectra is at least as good as, and often better than, what is observed for Boltzmann-weighted spectra. As the weights are available before the costly step of spectrum calculation, the method has the additional advantage of enabling efficient approximations. For simulating the molecular dynamics of the studied α,β-linked thiophenes and 2-methylthiophenes, high quality parameters have been derived for the CHARMM force field. Furthermore, the temperature dependence of the IR and Raman spectra have been investigated, both experimentally and theoretically.

  • 43.
    Sjöqvist, Jonas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Maria, Jerôme
    Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
    Simon, Rozalyn
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Lindgren, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology. Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
    Toward a molecular understanding of the detection of amyloid proteins with flexible conjugated oligothiophenes2014In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 118, no 42, p. 9820-9827Article in journal (Refereed)
    Abstract [en]

    Molecular and electronic structures and optical absorption properties of oligothiophenes used for spectral assignment of amyloid deposits have been investigated for a family of probes known as luminescent conjugated oligothiophenes (LCOs). Theoretical absorption spectra have been determined using conformational averaging, combining classical molecular dynamics (MD) simulations with quantum mechanical/molecular mechanics (QM/MM) time-dependent density functional theory (TD-DFT) spectrum calculations. Theoretical absorption spectra are in excellent agreement with experiments, showing average errors below 5 nm for absorption maxima. To couple observed properties to molecular structures, a measure of planarity is defined, revealing a strong correlation between the transition wavelength of the first and dominating electronically excited state and dihedral rotations. It is shown that from this correlation, predictions can be made of the absorption properties of probes based only on information from MD trajectories. We show experimentally that red shifts observed in the excitation maxima of LCOs when bound to amyloid protein aggregates are also evident in absorption spectra. We predict that these red shifts are due to conformational restriction of the LCO in a protein binding pocket, causing a planarization of the conjugated backbone. On the basis of our studies of planarity, it is shown that such shifts are both possible and realistic.

  • 44.
    Svensson, David
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Synthesis and characterisation of polyelectrolytes based on polymers of diallyldimethyl ammonium chloride and poly(styrene-co-butadiene)2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In printed electronics there are many polyelectrolytes to choose from. While polyelectrolytes such as polystyrene sulfonic acid can fulfill many ofthe desired functionalities of a semiconductor, there is a need for other polyelectrolytes with other functionalities, such as functionality at low airhumidity and better cross-linking possibilities, while still functioning as a good semiconductor.Within this thesis, there is a description of general polyelectrolytes, as well as various usages.The synthesis and characterization of new polyelectrolytes that have been developed, based upon diallyldimethyl ammonium chloride (DADMAC)and a derivative of polystyrene sulfonic acid (PSSH) is described.The study and experimental testing of the polymers as polyelectrolytes under different conditions is described.

  • 45.
    Tengdelius, Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Fucoidan-Mimetic Glycopolymers: Synthesis and Biomedical Applications2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The marine polysaccharide fucoidan has demonstrated several interesting biological properties, for instance being antiviral, anticoagulant, anti-inflammatory, anticancer, and platelet activating. Many of these properties are desirable for various biomedical applications. Yet, there are few reports on fucoidan being used in such applications. The reasons for this are primarily the heterogeneity and low structural reproducibility of fucoidan.

    This thesis describes the synthesis of polymers with pendant saccharides bearing the key structural features of fucoidan. These glycopolymers were synthesized via different radical polymerization techniques yielding polymers of different chain lengths and dispersity. These glycopolymers showed antiviral and platelet activating properties similar to those of natural fucoidan, thus making them fucoidan-mimetic glycopolymers. However, compared to fucoidan from natural sources, the fucoidan-mimetic glycopolymers had homogeneous and reproducible structures making them suitable for biomedical applications.

    Further studies demonstrated that platelet activation, caused by these glycopolymers, showed dose-response curves almost identical to fucoidan. The platelet activation was induced via intracellular signaling and caused platelet surface changes similar to those of fucoidan. Fucoidan-mimetic glycopolymers can therefore be used as unique biomolecular tools for studying the molecular and cellular responses of human platelets.

    Fucoidan-mimetic glycopolymers generally assert their antiviral activity by blocking viral entry to host cells, thus inhibiting spreading of the viral infection but not acting virucidal, i.e. not killing the viruses. Introduction of hydrophobic groups to the polymer’s chain ends improved the antiviral properties significantly and is an important step towards yielding glycopolymers with virucidal properties.

    The fucoidan-mimetic glycopolymers were also applied as capping agents when synthesizing gold nanoparticles. These fucoidan-mimetic glycopolymer coated gold nanoparticles showed improved colloidal stability compared to uncapped gold nanoparticles. Furthermore, the nanoparticles also demonstrated selective cytotoxicity against a human colon cancer cell line over fibroblast cells.

    List of papers
    1. Synthesis and biological evaluation of fucoidan-mimetic glycopolymers through cyanoxyl-mediated free-radical polymerization
    Open this publication in new window or tab >>Synthesis and biological evaluation of fucoidan-mimetic glycopolymers through cyanoxyl-mediated free-radical polymerization
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    2014 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 15, no 7, p. 2359-2368Article in journal (Refereed) Published
    Abstract [en]

    The sulfated marine polysaccharide fucoidan has been reported to have health benefits ranging from antivirus and anticancer properties to modulation of high blood pressure. Hence, they could enhance the biological function of materials for biomedical applications. However, the incorporation of fucoidan into biomaterials has been difficult, possibly due to its complex structure and lack of suitable functional groups for covalent anchoring to biomaterials. We have developed an approach for a rapid synthesis of fucoidanmimetic glycopolymer chains through cyanoxyl-mediated free-radical polymerization, a method suitable for chain-end functionalizing and subsequent linkage to biomaterials. The resulting sulfated and nonsulfated methacrylamido alpha-L-fucoside glycopolymers fucoidan-mimetic properties were studied in HSV-1 infection and platelet activation assays. The sulfated glycopolymer showed similar properties to natural fucoidan in inducing platelet activation and inhibiting HSV-1 binding and entry to cells, thus indicating successful syntheses of fucoidan-mimetic glycopolymers.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2014
    National Category
    Chemical Sciences Clinical Medicine Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-109382 (URN)10.1021/bm5002312 (DOI)000339090500003 ()24813544 (PubMedID)
    Available from: 2014-08-15 Created: 2014-08-15 Last updated: 2017-12-05Bibliographically approved
    2. Synthesis and anticancer properties of fucoidan-mimetic glycopolymer coated gold nanoparticles
    Open this publication in new window or tab >>Synthesis and anticancer properties of fucoidan-mimetic glycopolymer coated gold nanoparticles
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    2015 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 51, no 40, p. 8532-8535Article in journal (Refereed) Published
    Abstract [en]

    Gold nanoparticles coated with fucoidan-mimetic glycopolymers were synthesized that displayed good colloidal stability and promising anti-cancer properties. Fucoidan mimetic glycopolymers on their own were nontoxic, while glycopolymer coated gold nanoparticles displayed selective cytotoxicity to human colon cancer cell lines (HCT116) while it was non-toxic to mouse fibroblast cells (NIH3T3).

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2015
    National Category
    Chemical Sciences Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-119269 (URN)10.1039/c5cc02387d (DOI)000354043200034 ()25892661 (PubMedID)
    Note

    Funding Agencies|Swedish Strategic Research StemTherapy

    Available from: 2015-06-12 Created: 2015-06-12 Last updated: 2017-12-04
  • 46.
    Thinprakong, Chorpure
    Linköping University. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Excitation transfer between conjugated polyelectrolytes and triplet emitter confined in protein nanowires2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Phosphorescent metal complexes can be incorporated into amyloid-like fibrils, and these fibrils can be decorated with conjugated polyelectrolytes (CPEs). In this study, fac-tris[2-phenylpyridinato-C2,N]irdium(III) complexes [Ir(piq)3] were used as the phosphorescence emitter and Sodium-poly(3-thiophene acetic acid) (PTAA-Na) compounds were used as CPEs. Herein we study the energy transfer processes between the iridium complexes and the CPEs. To investigate these mechanisms, the analysis of the emission quenching and time-resolved measurements were done. Our measurements show that energy can be transfered from singlet state of PTAA to the singlet state of Ir(piq)3. Moreover, incorporation of iridium into amyloid fibrils decreases the importance of energy transfer by the Dexter mechanism. Finally we propose a geometry of interaction to explain the obtained results.

  • 47.
    Thorstensson, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, The Institute of Technology.
    Structure-Based Design and Synthesis of Protease Inhibitors Using Cycloalkenes as Proline Bioisosteres and Combinatorial Syntheses of a Targeted Library2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Structure-based drug design and combinatorial chemistry play important roles in the search for new drugs, and both these elements of medicinal chemistry were included in the present studies. This thesis outlines the synthesis of protease inhibitors against thrombin and the HCV NS3 protease, as well as the synthesis of a combinatorial library using solid phase chemistry.In the current work potent thrombin inhibitors were generated based on the D-Phe-Pro-Arg motif incorporating cyclopentene and cyclohexene scaffolds that were synthesized by ring-closing metathesis chemistry. A structure-activity relationship study was carried out using the crystallographic results for one of the inhibitors co-crystallized with thrombin. HCV NS3 protease inhibitors comprising the proline bioisostere 4-hydroxy-cyclopent-2-ene-1,2-dicarbboxylic acid were synthesized displaying low nanomolar activity. The stereochemistry and regiochemistry of the scaffolds were determined by NOESY and HMBC spectra, respectively. The final diastereomeric target compounds were isolated and annotated by applying TOCSY and ROESY NMR experiments. Furthermore, a 4-phenyl-2-carboxypiperazine targeted combinatorial chemistry library was synthesized to be used early in the lead discovery phase. This was done using a scaffold that was synthesized by palladiumcatalyzed aromatic amination chemistry and subsequently derivatized with eight electrophiles and ten nucleophiles.

    List of papers
    1. Solid-phase synthesis of libraries generated from a 4-phenyl-2-carboxy-piperazine Scaffold
    Open this publication in new window or tab >>Solid-phase synthesis of libraries generated from a 4-phenyl-2-carboxy-piperazine Scaffold
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    2001 (English)In: Journal of Combinatorial Chemistry, ISSN 2156-8952, Vol. 3, no 6, p. 546-553Article in journal (Refereed) Published
    Abstract [en]

    Strategies for finding novel structures of therapeutical interest are discussed. The rationale for the selection of the two scaffolds N4-(m-aminophenyl)-piperazine-2-carboxylic acid E and N4-(o-aminophenyl)-piperazine-2-carboxylic F is described. The synthesis of the appropriate precursors to scaffold E and F and their use in solid-phase chemistry are described. A 160-member library was produced combining these novel piperazine scaffolds with eight sulfonyl chlorides/acid chlorides and 10 amines. The compound library prepared was analyzed using LC-MS, showing the expected base peak in all wells at an average purity of 82%.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2001
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13467 (URN)10.1021/cc010013o (DOI)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2018-05-21
    2. Synthesis of Novel Thrombin Inhibitors. Use of Ring-Closing Metathesis Reactions for Synthesis of P2 Cyclopentene and Cyclohexene Dicarboxylic Acid Derivatives
    Open this publication in new window or tab >>Synthesis of Novel Thrombin Inhibitors. Use of Ring-Closing Metathesis Reactions for Synthesis of P2 Cyclopentene and Cyclohexene Dicarboxylic Acid Derivatives
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    2003 (English)In: Journal of Medicinal Chemistry, ISSN 0022-2623, Vol. 46, no 7, p. 1165-1179Article in journal (Refereed) Published
    Abstract [en]

    The thrombin inhibitory tripeptide d-Phe-Pro-Arg has been mimicked using either cyclopentenedicarboxylic derivatives or a cyclohexenedicarboxylic derivative as surrogate for the P2 proline. In the P3 position, tertiary amides were optimized as d-Phe P3 replacements. The P1 arginine was, in all compounds, substituted with the more rigid and biocompatible 4-aminomethylbenzamidine. One of the novel inhibitors was cocrystallized with α-thrombin and subjected to X-ray analysis. From analysis of the X-ray crystal structure, new ligands were designed leading to significantly improved binding affinity, the lead candidate exhibiting an in vitro IC50 of 49 nM.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13468 (URN)10.1021/jm021065a (DOI)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2009-06-05
    3. Synthesis of Novel Potent Hepatitis C Virus NS3 Protease Inhibitors: Discovery of 4-Hydroxy-cyclopent-2-ene-1,2-dicarboxylic Acid as a N-Acyl-L-Hydroxyproline Bioisostere
    Open this publication in new window or tab >>Synthesis of Novel Potent Hepatitis C Virus NS3 Protease Inhibitors: Discovery of 4-Hydroxy-cyclopent-2-ene-1,2-dicarboxylic Acid as a N-Acyl-L-Hydroxyproline Bioisostere
    Show others...
    2007 (English)In: Bioorganic & medicinal chemistry, ISSN 0968-0896, Vol. 15, no 2, p. 827-838Article in journal (Refereed) Published
    Abstract [en]

    Potent tetrapeptidic inhibitors of the HCV NS3 protease have been developed incorporating 4-hydroxy-cyclopent-2-ene-1,2-dicarboxylic acid as a new N-acyl-l-hydroxyproline mimic. The hydroxycyclopentene template was synthesized in eight steps from commercially available (syn)-tetrahydrophthalic anhydride. Three different amino acids were explored in the P1-position and in the P2-position the hydroxyl group of the cyclopentene template was substituted with 7-methoxy-2-phenyl-quinolin-4-ol. The P3/P4-positions were then optimized from a set of six amino acid derivatives. All inhibitors were evaluated in an in vitro assay using the full-length NS3 protease. Several potent inhibitors were identified, the most promising exhibiting a Ki value of 1.1 nM.

    Keywords
    HCV; NS3; Protease inhibitor; N-Acyl-l-hydroxyproline mimic; 4-Hydroxy-cyclopent-2-ene-1, 2-dicarboxylic acid; Cyclopentene
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13983 (URN)10.1016/j.bmc.2006.10.044 (DOI)
    Available from: 2006-09-14 Created: 2006-09-14 Last updated: 2009-05-15
  • 48.
    Tian, Xiaohe
    et al.
    Anhui University, Peoples R China.
    Zhang, Qian
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. Anhui University, Peoples R China.
    Zhang, Mingzhu
    Anhui University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wang, Qin
    Anhui Agriculture University, Peoples R China.
    Chen, Junyang
    Anhui University, Peoples R China.
    Du, Wei
    Anhui University, Peoples R China.
    Huang, Bei
    Anhui University, Peoples R China.
    Wu, Jieying
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China; Nanjing University, Peoples R China.
    Probe for simultaneous membrane and nucleus labeling in living cells and in vivo bioimaging using a two-photon absorption water-soluble Zn(II) terpyridine complex with a reduced pi-conjugation system2017In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 8, no 1, p. 142-149Article in journal (Refereed)
    Abstract [en]

    Small, biocompatible and water-soluble molecules with high two-photon absorption (2PA) cross-section values (delta) are in high demand for specific bioimaging applications. Here, two novel terpyridine derivative ligands with donor-acceptor (D-A) (L1) and donor-pi-acceptor (D-pi-A) (L2) models, and their corresponding Zn(II) complexes are designed and characterized. It was found that the two-photon absorption cross section values (d) in the near-infrared region (NIR, about 800 nm) are significantly enhanced for complexes 1 and 2 compared to their free D-A type ligand L1, while those of complexes 3 and 4 were greatly decreased relative to their free ligand L2, thus confirming that the smaller ligand (D-A type) displays a suitable Turn-ON fluorescence pair for two-photon fluorescence microscopy (2PFM). Firstly, the potential of simultaneously labeling a live cell plasma membrane and nucleus using complex 1 is demonstrated. In addition, live larval and adult zebrafish incubated with an optimal concentration of 1 demonstrated clear brain uptake. Lastly and importantly, using such a probe to visualize the blood-brain- barrier (BBB) capillary endothelial cells and penetrate the BBB into the central nervous system (CNS) intravenously in a mouse model is also explored.

  • 49.
    Trupina, Snjezana
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, Department of Physics, Chemistry and Biology.
    Synthesis of Metalloporphyrins with Oligothiophenes as Probes for Amyloid Diseases2010Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Abnormal aggregation of misfolded proteins is related to numerous neurodegenerative diseases, which include Alzheimer’s, Parkinson’s disease and prion diseases. Luminescent conjugated probes (LCPs) have been used as dyes for these supramolecular assemblies termed amyloid fibrils. To these probes, metalloporphyrin (MP) derivates have been attached to achieve new spectroscopic properties, which will allow for new ways to study protein aggregation diseases.

    In this thesis the synthesis of two different LCPs anchored porphyrin derivates are described. The LCPs are synthesized from 3-thiopheneacetic acid and additional thiophene units are added with the use of Suzuki cross coupling reaction. The porphyrin is synthesized from pyrrol, benzaldehyde and methyl-4- formylbenzoate in a condensation reaction. In the first target molecule (TM) the porphyrin and thiophene are coupled with a spacer and the second one is a direct coupling between the two compounds.

  • 50.
    Wallgren, Jakob
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Vikingsson, Svante
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Johansson, Anders
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Josefsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Green, Henrik
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Dahlén, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Wu, Xiongyu
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Synthesis and identification of an important metabolite of AKB-48 with a secondary hydroxyl group on the adamantyl ring2017In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 58, no 15, p. 1456-1458Article in journal (Refereed)
    Abstract [en]

    Studies on the metabolism of bioactive substances containing the adamantyl moiety have shown that hydroxylation is likely to occur at a tertiary carbon of adamantane. Herein, we report the synthesis and identification of one major metabolite of AKB-48, a new illicit psychoactive substance with a hydroxyl group at a secondary carbon of the adamantyl ring. (C) 2017 Elsevier Ltd. All rights reserved.

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