Artikler, rapporter og annet (kjemi): Nye registreringer
Viser treff 401-420 av 565
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3,4-Dihydroquinoxalin-2-ones: recent advances in synthesis and bioactivities
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-26)A summary of recent synthesis approaches to 3,4-dihydroquinoxaline-2-ones is discussed herein along with highlights of biological activity. The synthetic approaches include access to enantiopure heterocycles from chiral pool amino acids via coupling/cyclization, Michael addition/cyclization cascades, 3,3-disubstituted systems from multicomponent couplings, Bargellini reaction or photochemical ... -
EURODELTA-Trends, a multi-model experiment of air quality hindcast in Europe over 1990-2010
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-05)The EURODELTA-Trends multi-model chemistry-transport experiment has been designed to facilitate a better understanding of the evolution of air pollution and its drivers for the period 1990–2010 in Europe. The main objective of the experiment is to assess the efficiency of air pollutant emissions mitigation measures in improving regional-scale air quality. <br>The present paper formulates the ... -
Metallo-β-lactamase inhibitors by bioisosteric replacement: preparation, activity and binding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-14)Bacterial resistance is compromising the use of β-lactam antibiotics including carbapenems. The main resistance mechanism against β-lactams is hydrolysis of the β-lactam ring mediated by serine- or metallo-β-lactamases (MBLs). Although several inhibitors of MBLs have been reported, none has been developed into a clinically useful inhibitor. Mercaptocarboxylic acids are among the most prominent ... -
Energetics of saddling versus ruffling in metalloporphyrins: Unusual ruffled dodecasubstituted porphyrins
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-13)Presented herein is a first major density functional theory (BP86/D3/STO-TZ2P) survey of the energetics of saddling versus ruffling for a wide range of dodecasubstituted metalloporphyrins with M = Ni, Cu, Zn, Pd, and Pt. For the majority of X<sub>8</sub>TPP (i.e., β-octasubstituted-meso-tetraphenylporphyrin), the calculations indicated a clear preference for the saddled conformation, consistent with ... -
Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-29)Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation ... -
Structural insight into a CE15 esterase from the marine bacterial metagenome
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-08)The family 15 carbohydrate esterase (CE15) MZ0003, which derives from a marine Arctic metagenome, has a broader substrate scope than other members of this family. Here we report the crystal structure of MZ0003, which reveals that residues comprising the catalytic triad differ from previously-characterized fungal homologs, and resolves three large loop regions that are unique to this bacterial ... -
Data driven polypharmacological drug design for lung cancer: analyses for targeting ALK, MET, and EGFR
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-04)Drug design of protein kinase inhibitors is now greatly enabled by thousands of publicly available X-ray structures, extensive ligand binding data, and optimized scaffolds coming off patent. The extensive data begin to enable design against a spectrum of targets (polypharmacology); however, the data also reveal heterogeneities of structure, subtleties of chemical interactions, and apparent inconsistencies ... -
Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials
(Journal article; Tidsskriftartikkel, 2017-05-02)Accurate prediction of triplet excitation energies for transition metal complexes has proven to be a difficult task when confronted with a variety of metal centers and ligand types. Specifically, phosphorescent transition metal light emitters, typically based on iridium or platinum, often give calculated results of varying accuracy when compared to experimentally determined T1 emission values. ... -
β-Octabromo- and β-Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-26)Presented herein is a study of the acid-induced demetalation of two sterically hindered copper corroles, Cu b-octabromomeso-triphenylcorrole (Cu[Br8TPC]) and b-octakis(trifluoromethyl)-meso-tris(p-methoxyphenyl)corrole (Cu[(CF3 )8TpOMePC]). Unlike reductive demetalation, which affords the free-base boctabromocorrole, demetalation of Cu[Br8TPC] under nonreductive conditions (CHCl3 /H2SO4 ) ... -
One-Pot Synthesis of a bis-Pocket Corrole through a 14-fold Bromination Reaction.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-14)A one-pot protocol, effecting 14-fold bromination with elemental bromine, has afforded copper β-octabromo-meso-tris (2,6-dibromo-3,5-dimethoxyphenyl) corrole, a new bis-pocket metallocorrole. The Cu complex underwent smooth demetalation under reductive conditions, affording the free corrole ligand, which in turn could be readily complexed to MnIII and AuIII. A single-crystal X-ray structure was ... -
Dynamical models of mutated chronic myelogenous leukemia cells for a postimatinib treatment scenario: Response to dasatinib or nilotinib therapy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-05)Targeted inhibition of the oncogenic BCR-ABL1 fusion protein using the ABL1 tyrosine kinase inhibitor imatinib has become standard therapy for chronic myelogenous leukemia (CML), with most patients reaching total and durable remission. However, a significant fraction of patients develop resistance, commonly due to mutated ABL1 kinase domains. This motivated development of second-generation drugs ... -
A comparative study of cold-and warmadapted Endonucleases A using sequence analyses and molecular Dynamics simulations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-13)The psychrophilic and mesophilic endonucleases A (EndA) from Aliivibrio salmonicida (VsEndA) and Vibrio cholera (VcEndA) have been studied experimentally in terms of the biophysical properties related to thermal adaptation. The analyses of their static X-ray structures was no sufficient to rationalize the determinants of their adaptive traits at the molecular level. Thus, we used Molecular Dynamics ... -
Structure and function of a CE4 deacetylase isolated from a marine environment
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-06)Chitin, a polymer of β(1–4)-linked N-acetylglucosamine found in e.g. arthropods, is a valuable resource that may be used to produce chitosan and chitooligosaccharides, two compounds with considerable industrial and biomedical potential. Deacetylating enzymes may be used to tailor the properties of chitin and its derived products. Here, we describe a novel CE4 enzyme originating from a marine ... -
Gauge-origin independent calculations of electric-field-induced second-harmonic generation circular intensity difference using London atomic orbitals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)We present the first gauge-origin independent calculations of the circular intensity difference (CID) in electric-field-induced second-harmonic generation (EFISHG), including all contributions up to the electric-quadrupole–magnetic-dipole level. A recursive, open-ended response theory framework in combination with the use of London atomic orbitals allows us to ensure gauge-origin independent results. ... -
Channel interference in multiphoton absorption
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-30)We extend the theory of channel interference to higher-order multiphoton absorption processes. We derive an explicit expression for channel interference in a three-photon absorption process and propose a general scheme for deriving such expressions for multiphoton absorption processes of any order. Based on this general scheme, we derive and analyze the simplest few-state models for multiphoton ... -
Structure, activity and thermostability investigations of OXA-163, OXA-181 and OXA-245 using biochemical analysis, crystal structures and differential scanning calorimetry analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)The first crystal structures of the class D β-lactamases OXA-181 and OXA-245 were determined to 2.05 and 2.20 Å resolution, respectively; in addition, the structure of a new crystal form of OXA-163 was resolved to 2.07 Å resolution. All of these enzymes are OXA-48-like and have been isolated from different clinical Klebsiella pneumoniae strains and also from other human pathogens such as Pseudomonas ... -
One‐Pot Synthesis of a bis‐Pocket Corrole through a 14‐fold Bromination Reaction
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-14)A one-pot protocol, effecting 14-fold bromination with elemental bromine, has afforded copper beta-octabromo-meso-tris(2,6-dibromo-3,5-dimethoxyphenyl)corrole, a new bis-pocket metallocorrole. The Cu complex underwent smooth demetalation under reductive conditions, affording the free corrole ligand, which in turn could be readily complexed to Mn<sup>III</sup> and Au<sup>III</sup>.A single-crystal ... -
The Dalton quantum chemistry program system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05)Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree–Fock, Kohn–Sham, multiconfigurational self-consistent-field, Møller–Plesset, configuration-interaction, and coupled-cluster levels of theory. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients ... -
A Dihydride Mechanism Can Explain the Intriguing Substrate Selectivity of Iron-PNP-Mediated Hydrogenation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-24)Iron-PNP pincer complexes are efficient catalysts for the hydrogenation of aldehydes and ketones. A variety of hydrogenation mechanisms have been proposed for these systems, but there appears to be no clear consensus on a preferred pathway. We have employed high-level quantum chemical calculations to evaluate various mechanistic possibilities for iron-PNP catalysts containing either CH2, NCH3, ... -
Averaged Solvent Embedding Potential Parameters for Multiscale Modeling of Molecular Properties
(Journal article; Tidsskriftartikkel, 2016-03-03)We derive and validate averaged solvent parameters for embedding potentials to be used in polarizable embedding quantum mechanics/molecular mechanics (QM/MM) molecular property calculations of solutes in organic solvents. The parameters are solvent-specific atom-centered partial charges and isotropic polarizabilities averaged over a large number of geometries of solvent molecules. The use ...