Institutt for kjemi: Recent submissions
Now showing items 141-160 of 611
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Computer Simulation of Antimicrobial Agents
(Master thesis; Mastergradsoppgave, 2021-10-15)The last 18 months has shown the impact a single microorganism can have on society with the SARS-CoV-2 virus. This is not the only global threat on our health, with the World Health Organisation and other government agencies warning against the increase in antimicrobial resistance today. Antimicrobial peptides have been seen as a possible solution, as they are known to fight bacteria as a part of ... -
Tailored Leaching Tests as a Tool for Environmental Management of Mine Tailings Disposal at Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-10)The expanding human activities in coastal areas increase the need for developing solutions to limit impacts on the marine environment. Sea disposal affects the marine environment, but despite the growing knowledge of potential impacts, there are still no standardized leaching tests for sea disposal. The aim of this study was to contribute to the development of leaching tests, exemplified using ... -
Cobalt-Catalyzed Asymmetric Hydrogenation of Enamides: Insights into Mechanisms and Solvent Effects
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-25)The mechanistic details of the (<sup>Ph</sup>BPE)Co-catalyzed asymmetric hydrogenation of enamides are investigated using computational and experimental approaches. Four mechanistic possibilities are compared: a direct Co(0)/Co(II) redox path, a metathesis pathway, a nonredox Co(II) mechanism featuring an azametallacycle, and a possible enamide−imine tautomerization pathway. The results indicate ... -
Anodic Activity of Hydrated and Anhydrous Iron (II) Oxalate in Li-Ion Batteries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-12)We discuss the applicability of the naturally occurring compound Ferrous Oxalate Dihydrate (FOD) (FeC2O4·2H2O) as an anode material in Li-ion batteries. Using first-principles modeling, we evaluate the electrochemical activity of FOD and demonstrate how its structural water content affects the intercalation reaction and contributes to its performance. We show that both Li0 and Li+ intercalation in ... -
Critical Assessment of Metagenome Interpretation: the second round of challenges
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-08)Evaluating metagenomic software is key for optimizing metagenome interpretation and focus of the Initiative for the Critical Assessment of Metagenome Interpretation (CAMI). The CAMI II challenge engaged the community to assess methods on realistic and complex datasets with long- and short-read sequences, created computationally from around 1,700 new and known genomes, as well as 600 new plasmids ... -
Role of conical intersection seam topography in the chemiexcitation of 1,2-dioxetanes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-06)Chemiexcitation, the generation of electronic excited states by a thermal reaction initiated on the ground state, is an essential step in chemiluminescence, and it is mediated by the presence of a conical intersection that allows a nonadiabatic transition from ground state to excited state. Conical intersections classified as sloped favor chemiexcitation over ground state relaxation. The chemiexcitation ... -
Complete analytic anharmonic hyper-Raman scattering spectra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-11)We present the first computational treatment of the complete second-order vibrational perturbation theory applied to hyper-Raman scattering spectroscopy. The required molecular properties are calculated in a fully analytic manner using a recently developed program [Ringholm, Jonsson and Ruud, J. Comp. Chem., 2014, 35, 622] that utilizes recursive routines. For some of the properties, these ... -
Presence of acyl-homoserine lactones in 57 members of the Vibrionaceae family
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-31)Aims: The aim of this study was to use a sensitive method to screen and quantify 57 Vibrionaceae strains for the production of acyl-homoserine lactones (AHLs) and map the resulting AHL profiles onto a host phylogeny.<p> <p>Methods and Results: We used a high-performance liquid chromatography– tandem mass spectrometry (HPLC-MS/MS) protocol to measure AHLs in spent media after bacterial growth. ... -
NMR Backbone Assignment of VIM-2 and Identification of the Active Enantiomer of a Potential Inhibitor
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-28)Carbapenem resistance caused by metallo-β-lactamases is a serious global challenge that, if not tackled efficiently, is expected to lead to millions of deaths in the coming decades. Verona-integron encoded metallo-β-lactamase 2 (VIM-2) is a bacterial enzyme that has been reported from multidrug-resistant nosocomial isolates of Pseudomonas aeruginosa and other Gram-negative pathogens. As it hydrolyzes ... -
Structure and Mechanism of a Cold-Adapted Bacterial Lipase
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-03)The structural origin of enzyme cold-adaptation has been the subject of considerable research efforts in recent years. Comparative studies of orthologous mesophilic–psychrophilic enzyme pairs found in nature are an obvious strategy for solving this problem, but they often suffer from relatively low sequence identity of the enzyme pairs. Small bacterial lipases adapted to distinctly different ... -
Evaluating the Predictivity of Virtual Screening for Abl Kinase Inhibitors to Hinder Drug Resistance
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-06-08)Virtual screening methods are now widely used in early stages of drug discovery, aiming to rank potential inhibitors. However, any practical ligand set (of active or inactive compounds) chosen for deriving new virtual screening approaches cannot fully represent all relevant chemical space for potential new compounds. In this study, we have taken a retrospective approach to evaluate virtual screening ... -
Exploring Palladium-Catalyzed Cross-Coupling at Nitrile Groups
(Master thesis; Mastergradsoppgave, 2022-05-16)Carbon-Carbon cross-coupling is a useful method that is used to connect carbons of different molecules to create a larger molecule. This is particularly powerful in synthesis of complicated molecules because it allows for different parts of the target molecule to be worked with separately before they are connected, which reduces the restrictions on the methods used during synthesis. One major drawback ... -
Chiral recognition by fullerenes: CHFClBr enantiomers in the C82 cage
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-18)Density-functional theory and symmetry-adapted perturbation theory calculations on complexes of the enantiomers of CHFClBr with the most stable isomer of C<sub>82</sub>-3 fullerene show that despite the guests being too large for the host cage, they are nevertheless stabilized by electrostatic interactions. The complexation leads to considerable strain on the cage and the guests accompanied by ... -
The impact of interplay between electronic and steric effects on the synthesis and the linear and non-linear optical properties of diketopyrrolopyrrole bearing benzofuran moieties
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-07)An in-depth investigation of the reaction of substituted salicylaldehydes with chloroacetonitrile led to the development of new conditions for the synthesis of 2-cyanobenzofurans. The crucial improvement lies in the use of phase-transfer catalysis in the second step, i.e., intramolecular aldol type condensation. In a two-step process, the reactants were transformed into a library of 3,6-bis(ben ... -
Computational and experimental insights into asymmetric Rh‐catalyzed hydrocarboxylation with CO2
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-18)The asymmetric Rh‐catalyzed hydrocarboxylation of α,β‐unsaturated carbonyl compounds was originally developed by Mikami and co‐workers but gives only moderate enantiomeric excesses. In order to understand the factors controlling the enantioselectivity and to propose novel ligands for this reaction, we have used computational and experimental methods to study the Rh‐catalyzed hydrocarboxylation with ... -
Origin-independent two-photon circular dichroism calculations in coupled cluster theory
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-03)We present the first origin-independent approach for the treatment of two-photon circular dichroism (TPCD) using coupled cluster methods. The approach is assessed concerning its behavior on the choice of the basis set and different coupled cluster methods. We also provide a comparison of results from CC2 with those from density functional theory using the CAM-B3LYP functional. Concerning the basis ... -
Platinum corroles
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-06-09)Platinum has been inserted into corroles for the first time and three oxidized Pt<sup>IV</sup>(corrole<sup>2-</sup>)ArAr0 complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl - corrole<sup>2-</sup> charge transfer character in these transitions. -
The three Endonuclease III variants of Deinococcus radiodurans possess distinct and complementary DNA repair activities
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-28)Endonuclease III (EndoIII) is a bifunctional DNA glycosylase that removes oxidized pyrimidines from DNA. The genome of Deinococcus radiodurans encodes for an unusually high number of DNA glycosylases, including three EndoIII enzymes (drEndoIII1-3). Here, we compare the properties of these enzymes to those of their well-studied homologues from E. coli and human. Our biochemical and mutational data, ... -
Lactoferricin-inspired peptide AMC-109 augments the effect of ciprofloxacin against Pseudomonas aeruginosa biofilm in chronic murine wounds
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-23)Objectives: Chronic wounds are characterised by prolonged inflammation, low mitogenic activity, high protease/low inhibitor activity, microbiota changes and biofilm formation, combined with the aetiology of the original insult. One strategy to promote healing is to terminate the parasitism-like relationship between the biofilm-growing pathogen and host response. Antimicrobial peptide AMC-109 is a ... -
Identification and Cross-Characterisation of Artificial Promoters and 5′ Untranslated Regions in Vibrio natriegens
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-27)Vibrio natriegens has recently gained attention as a novel fast-growing bacterium in synthetic biology applications. Currently, a limited set of genetic elements optimised for Escherichia coli are used in V. natriegens due to the lack of DNA parts characterised in this novel host. In this study, we report the identification and cross-characterisation of artificial promoters and 5′ untranslated ...