| 1. |
- Magoulas, George E., et al.
(författare)
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Synthesis and antiproliferative activity of two diastereomeric lignan amides serving as dimeric caffeic acid-l-DOPA hybrids
- 2016
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Ingår i: Bioorganic Chemistry. - : Elsevier BV. - 0045-2068. ; 66, s. 132-144
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Tidskriftsartikel (refereegranskat)abstract
- Two new diastereomeric lignan amides (4 and 5) serving as dimeric caffeic acid-l-DOPA hybrids were synthesized. The synthesis involved the FeCl3-mediated phenol oxidative coupling of methyl caffeate to afford trans-diester 1a as a mixture of enantiomers, protection of the catechol units, regioselective saponification, coupling with a suitably protected l-DOPA derivative, separation of the two diastereomers thus obtained by flash column chromatography and finally global chemoselective deprotection of the catechol units. The effect of hybrids 4 and 5 and related compounds on the proliferation of two breast cancer cell lines with different metastatic potential and estrogen receptor status (MDA-MB-231 and MCF-7) and of one epithelial lung cancer cell line, namely A-549, was evaluated for concentrations ranging from 1 to 256 μM and periods of treatment of 24, 48 and 72 h. Both hybrids showed interesting and almost equipotent antiproliferative activities (IC50 64-70 μM) for the MDA-MB-231 cell line after 24-48 h of treatment, but they were more selective and much more potent (IC50 4-16 μM) for the MCF-7 cells after 48 h of treatment. The highest activity for both hybrids and both breast cancer lines was observed after 72 h of treatment (IC50 1-2 μM), probably as the result of slow hydrolysis of their methyl ester functions.
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| 2. |
- Fakhardji, Wissam, et al.
(författare)
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Collision-induced absorption in Ar–Kr gas mixtures : A molecular dynamics study with new potential and dipole data
- 2019
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 151:14
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Tidskriftsartikel (refereegranskat)abstract
- We have implemented a scheme for classical molecular dynamics simulations of collision-induced absorption. The program has been applied to a gas mixture of argon (Ar) and krypton (Kr). The simulations are compared with accurate quantum dynamical calculations. The comparisons of the absorption coefficients show that classical molecular dynamics is correct within 10% for photon wave numbers up to 220 cm−1 at a temperature of 200 K for this system. At higher temperatures, the agreement is even better. Molecular dynamics accounts for many-body interactions, which, for example, give rise to continuous dimer formation and destruction in the gas. In this way, the method has an advantage compared with bimolecular classical (trajectory) treatments. The calculations are carried out with a new empirical Ar–Kr pair potential. This has been obtained through extensive analysis of experimental thermophysical and transport properties. We also present a new high level ab initio Ar–Kr potential curve for comparison, as well as ab initio interaction-induced dipole curves computed with different methods. In addition, the Ar–Kr polarizability and hyperpolarizability are reported. A comparison of the computed absorption spectra with an experiment taken at 300 K shows satisfactory agreement although a difference in absolute magnitude of 10%–15% persists. This discrepancy we attribute mainly to experimental uncertainty.
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| 3. |
- Fakhardji, Wissam, et al.
(författare)
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Contribution from dimers to the collision-induced absorption spectra in an Ar–Kr gas mixture
- 2019
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Ingår i: 24th International Conference on Spectral Lines Shapes 17-22 June 2018, Dublin, Ireland. - : Institute of Physics (IOP).
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Konferensbidrag (refereegranskat)abstract
- We have developed an empirical Barker, Fisher and Watts (BFW) interatomic potential for the Ar–Kr pair along with a dipole moment computed from first principles using Møller–Plesset perturbation theory to second order (MP2). Using these results, we performed molecular dynamics calculations to compute the Ar–Kr collision induced absorption (CIA) spectrum at different temperatures. By comparing them to other calculations using a two body interaction treated with quantum mechanics, we have shown that the difference is due to the dimer's contribution which grows in importance as the temperature is lowered.
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| 4. |
- Glaz, Waldemar, et al.
(författare)
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Effects of anisotropic interaction-induced properties of hydrogen-rare gas compounds on rototranslational Raman scattering spectra : Comprehensive theoretical and numerical analysis
- 2016
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 145:3
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Tidskriftsartikel (refereegranskat)abstract
- A comprehensive study is presented of many aspects of the depolarized anisotropic collision induced (CI) component of light scattered by weakly bound compounds composed of a dihydrogen molecule and a rare gas (Rg) atom, H2-Rg. The work continues a series of earlier projects marking the revival of interest in linear light scattering following the development of new highly advanced tools of quantum chemistry and other theoretical, computational, and experimental means of spectral analyses. Sophisticated ab initio computing procedures are applied in order to obtain the anisotropic polarizability component's dependence on the H2-Rg geometry. These data are then used to evaluate the CI spectral lines for all types of Rg atoms ranging from He to Xe (Rn excluded). Evolution of the properties of CI spectra with growing polarizability/masses of the complexes studied is observed. Special attention is given to the heaviest, Kr and Xe based, scatterers. The influence of specific factors shaping the spectral lines (e.g., bound and metastable contribution, potential anisotropy) is discussed. Also the share of pressure broadened allowed rotational transitions in the overall spectral profile is taken into account and the extent to which it is separable from the pure CI contribution is discussed. We finish with a brief comparison between the obtained results and available experimental data
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| 5. |
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| 6. |
- Gustafsson, Magnus, et al.
(författare)
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Calculated isotropic Raman spectra from interacting H2-rare-gas pairs
- 2014
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 548
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Tidskriftsartikel (refereegranskat)abstract
- We report on a theoretical study of the H2-He and H2-Ar pair trace-polarizability and the corresponding isotropic Raman spectra. The conventional quantum mechanical approach for calculations of interaction-induced spectra, which is based on an isotropic interaction potential, is employed. This is compared with a close-coupling approach, which allows for inclusion of the full, anisotropic potential. It is established that the anisotropy of the potential plays a minor role for these spectra. The computed isotropic collision-induced Raman intensity, which is due to dissimilar pairs in H2-He and H2-Ar gas mixtures, is comparable to the intensities due to similar pairs (H2-H2, He-He, and Ar-Ar), which have been studied previously.
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