| 1. |
- Caraballo, Remi, et al.
(författare)
-
Structure-activity relationships for lipoprotein lipase agonists that lower plasma triglycerides in vivo
- 2015
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier. - 0223-5234 .- 1768-3254. ; 103, s. 191-209
-
Tidskriftsartikel (refereegranskat)abstract
- The risk of cardiovascular events increases in individuals with elevated plasma triglyceride (TG) levels, therefore advocating the need for efficient TG-lowering drugs. In the blood circulation, TG levels are regulated by lipoprotein lipase (LPL), an unstable enzyme that is only active as a non-covalently associated homodimer. We recently reported on a N-phenylphthalimide derivative (1) that stabilizes LPL in vitro, and moderately lowers triglycerides in vivo (Biochem. Biophys. Res. Common. 2014, 450, 1063). Herein, we establish structure activity relationships of 51 N-phenylphthalimide analogs of the screening hit 1. In vitro evaluation highlighted that modifications on the phthalimide moiety were not tolerated and that lipophilic substituents on the central phenyl ring were functionally essential. The substitution pattern on the central phenyl ring also proved important to stabilize LPL However, in vitro testing demonstrated rapid degradation of the phthalimide fragment in plasma which was addressed by replacing the phthalimide scaffold with other heterocyclic fragments. The in vitro potency was retained or improved and substance 80 proved stable in plasma and efficiently lowered plasma TGs in vivo. 2015 The Authors. Published by Elsevier Masson SAS.
|
|
| 2. |
- Chateau, Denis, et al.
(författare)
-
Silica hybrid sol-gel materials with unusually high concentration of Pt-organic molecular guests : Studies of luminescence and nonlinear absorption of light
- 2012
-
Ingår i: ACS Applied Materials and Interfaces. - Washington : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 4:5, s. 2369-2377
-
Tidskriftsartikel (refereegranskat)abstract
- The development of new photonic materials is a key step towards improvement of existing optical devices and for the preparation of a new generation of systems. Therefore synthesis of photonic hybrid materials with a thorough understanding and control of the microstructure-to-properties relationships is crucial. In this perspective, a new preparation method based on fast gelation reactions using simple dispersion of dyes without strong covalent bonding between dye and matrix has been developed. This new sol-gel method is demonstrated through synthesis of monolithic siloxane-based hybrid materials highly doped by various platinum(II) acetylide derivatives. Concentrations of the chromophores as high as 400 mM were obtained and resulted in unprecedented optical power limiting (OPL) performance at 532 nm of the surface-polished solids. Static and time-resolved photoluminescence of the prepared hybrid materials were consistent with both OPL data and previous studies of similar Pt(II) compounds in solution. The impacts of the microstructure and the chemical composition of the matrix on the spectroscopic properties, are discussed.
|
|
| 3. |
- Glimsdal, Eirik, et al.
(författare)
-
Luminescence, singlet oxygen production, and optical power limiting of some diacetylide platinum(II) diphosphine complexes
- 2010
-
Ingår i: Journal of Physical Chemistry A. - : ACS Publications. - 1089-5639 .- 1520-5215. ; 114:10, s. 3431-3442
-
Tidskriftsartikel (refereegranskat)abstract
- A series of four new trans-diphosphine Pt(II) diacetylide complexes, with a thiophene and two benzenoid rings in each acetylide ligand, have been synthesized and characterized with respect to optical absorption, spectrally and time-resolved luminescence, and optically nonlinear properties such as two-photon absorption cross section and optical power limiting. Density functional theory (DFT) calculations of a few ground state conformations of three Pt(II) diacetylide structures showed similar total energy for each geometry-optimized rotamer but some differences in the vertical excitation energies and in the ligand-to-metal charge-transfer character. The wavelengths of the calculated excitations were found to be red-shifted compared with peaks in the optical absorption spectra, but the general trends and shifts of wavelengths between the different structures are well reproduced. Static emission spectra for degassed samples in THF solution of the larger compounds showed small Stokes shifts and low fluorescence quantum yields, indicating fast intersystem crossing to the triplet manifold. More pronounced differences between the compounds were displayed in the phosphorescence data, in terms of spectral emission wavelengths and decay times. For instance, the phosphorescence decay of the compound with the thiophene ring close to the Pt center was found to be significantly faster than for the other compounds. A possible relationship between triplet lifetime and conformation of the compounds is discussed. It was also demonstrated that the quenching of the excited triplet states in air-saturated samples involves energy transfer to the oxygen triplet state, and subsequent generation of singlet oxygen showing the typical emission at approximately 1275 nm. The amount of produced singlet oxygen followed the phosphorescence yields of the solute molecules. Two-photon absorption cross sections (sigma(2)) were measured and showed values on the order of 10 GM at 780 nm for all compounds. Optical power limiting measurements of the new complexes in THF using 5 ns pulses, showed only slightly better performance at the wavelength of 532 nm compared to that of similar platinum compounds with only two aryl rings in each ligand. At 600 nm the complexes with three aryl rings were significantly better optical limiters than the smaller compounds with two aryl rings in the ligands.
|
|
| 4. |
- Kindahl, Tomas, et al.
(författare)
-
Development and optimization of simple one-step methods for the synthesis of 4-amino-substituted 1,8-naphthalimides
- 2014
-
Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; :28, s. 6175-6182
-
Tidskriftsartikel (refereegranskat)abstract
- The 1,8-naphthalimide central fragment can be found in a vast number of bioactive compounds and drugs in clinical trials, and can be recognized from their use as fluorescent probes. Of key importance for the fluorescent properties of the scaffold is the 4-amino substituent, which has also proven to be critical in several other chemical and biological applications. Because of the great interest in 1,8-naphthalimides in general, and 4-amino-substituted 1,8-naphthalimides in particular, we have developed and optimized one-step procedures with which to access these derivatives by using an experimental design approach. The multivariate studies of temperature, reaction time, and equivalents of substrates identified conditions with close to quantitative yields that could be applied to generate a range of 4-amino-substituted 1,8-naphthalimides in high yields.
|
|
| 5. |
- Kindahl, Tomas, et al.
(författare)
-
Efficient one-step synthesis of 4-amino substituted phthalimides and evaluation of their potential as fluorescent probes
- 2014
-
Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 12:25, s. 4461-4470
-
Tidskriftsartikel (refereegranskat)abstract
- The phthalimide scaffold is recognized from bioactive compounds and marketed drugs, but can also be used as fluorescent probes by introducing a 4-amino substituent. Unfortunately, a general and convenient method to synthesize various 4-amino substituted phthalimides has been lacking. To overcome this, an atom efficient one-step synthesis of 4-amino substituted phthalimides in good to excellent yields that tolerate a wide range of substituents has been developed. Several of the generated compounds display interesting solvatochromic properties with high quantum yield of fluorescence in non-polar solvents that are significantly reduced in polar protic solvents. Many of these compounds displayed non-toxic properties and non-detectable unspecific binding and can thus potentially be linked to a substrate and used as fluorescent probes. Furthermore, bioactive and fluorescent 4-amino substituted phthalimides with IC50-values in the low micromolar range in cell-based assays have been identified and could be used to study uptake and distribution. The developed convenient synthetic method is thus valuable not only to construct fluorescent probes and fluorescent bioactive compounds to gain information about target binding, but also from a structure activity point of view in the various areas where the phthalimides have displayed activity.
|
|
| 6. |
- Kindahl, Tomas, et al.
(författare)
-
Photophysical and DFT Characterization of Novel Pt(II)-Coupled 2,5-Diaryloxazoles for Nonlinear Optical Absorption
- 2012
-
Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 116:47, s. 11519-11530
-
Tidskriftsartikel (refereegranskat)abstract
- Several new bis-phosphine platinum(II) complexes with 2,5-diaryl-substituted oxazole-containing alkyne ligands have been synthesized and optically characterized in solution. Measurements of nonlinear absorption showed strong attenuation of laser light at 532 and 600 nm. The light absorption of the Pt complexes was shifted from the near-UV region for the ground state to the red region for the excited triplet state, and was associated with large extinction coefficients. The optical limiting effect can be explained by triplet-triplet excited state absorption in conjunction with fast excited singlet to-triplet intersystem crossing and slow triplet to-ground-state decay, in comparison with the pulse length of the laser. DFT calculations show good predictability of the S-0-S-1 and S-0-T-1 energy gaps and offer insight into the interaction strength between Pt and the alkyne ligands. The use of this type of ligand, with weak absorption for the Pt(II) complexes in the visual wavelength range as a key feature, enables the possibility to further improve these molecular systems for nonlinear absorption applications.
|
|
| 7. |
- Kindahl, Tomas, 1980-
(författare)
-
Synthesis and development of compounds for nonlinear absorption of light
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- High-intensity light — for instance that from a laser — can be destructive, not only to the human eye, but also to equipment such as imaging sensors and optical communication devices. Therefore, effective protection against such light is desirable. A protection device should ideally have high transmission to non-damaging light, and should also be fast-acting in order to effectively stop high-intensity light.In working towards a protection device, there is a need to conduct fundamental research in order to understand the processes involved. One of the photophysical processes of special interest in the field of optical power limiting (OPL) is reverse saturable absorption, where a compound in an excited state absorbs light more strongly than it does in its ground state.In this work, several novel organoplatinum compounds for OPL, rationally designed to have a strong reverse saturable absorption, have been synthesized. The compounds have been analyzed using linear and nonlinear absorption spectroscopy, luminescence spectroscopy, and quantum chemistry calculations to gain further knowledge regarding their photophysical properties.In addition to this fundamental research, the absorption capabilities of some of these compounds indicate that they can be used for OPL applications. Consequently, compounds from these studies have been incorporated into a sol–gel glass that could be used in optical systems.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Knutsson, Sofie, et al.
(författare)
-
N-Aryl-N'-ethyleneaminothioureas effectively inhibit acetylcholinesterase 1 from disease-transmitting mosquitoes
- 2017
-
Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 134, s. 415-427
-
Tidskriftsartikel (refereegranskat)abstract
- Vector control of disease-transmitting mosquitoes by insecticides has a central role in reducing the number of parasitic- and viral infection cases. The currently used insecticides are efficient, but safety concerns and the development of insecticide-resistant mosquito strains warrant the search for alternative compound classes for vector control. Here, we have designed and synthesized thiourea-based compounds as non-covalent inhibitors of acetylcholinesterase 1 (AChE1) from the mosquitoes Anopheles gambiae (An. gambiae) and Aedes aegypti (Ae. aegypti), as well as a naturally occurring resistant-conferring mutant. The N-aryl-N'-ethyleneaminothioureas proved to be inhibitors of AChE1; the most efficient one showed submicromolar potency. Importantly, the inhibitors exhibited selectivity over the human AChE (hAChE), which is desirable for new insecticides. The structure-activity relationship (SAR) analysis of the thioureas revealed that small changes in the chemical structure had a large effect on inhibition capacity. The thioureas showed to have different SAR when inhibiting AChE1 and hAChE, respectively, enabling an investigation of structure-selectivity relationships. Furthermore, insecticidal activity was demonstrated using adult and larvae An. gambiae and Ae. aegypti mosquitoes.
|
|
