排序方式: 共有64条查询结果,搜索用时 15 毫秒
61.
ngel Snchez-Gonzlez Nuno A. G. Bandeira Iker Ortiz de Luzuriaga Frederico F. Martins Sawssen Elleuchi Khaled Jarraya Jose Lanuza Xabier Lopez Maria Jos Calhorda Adri Gil 《Molecules (Basel, Switzerland)》2021,26(16)
This work provides new insights from our team regarding advances in targeting canonical and non-canonical nucleic acid structures. This modality of medical treatment is used as a form of molecular medicine specifically against the growth of cancer cells. Nevertheless, because of increasing concerns about bacterial antibiotic resistance, this medical strategy is also being explored in this field. Up to three strategies for the use of DNA as target have been studied in our research lines during the last few years: (1) the intercalation of phenanthroline derivatives with duplex DNA; (2) the interaction of metal complexes containing phenanthroline with G-quadruplexes; and (3) the activity of Mo polyoxometalates and other Mo-oxo species as artificial phosphoesterases to catalyze the hydrolysis of phosphoester bonds in DNA. We demonstrate some promising computational results concerning the favorable interaction of these small molecules with DNA that could correspond to cytotoxic effects against tumoral cells and microorganisms. Therefore, our results open the door for the pharmaceutical and medical applications of the compounds we propose. 相似文献
62.
Runhai Chen Guorui Qin Shihui Li Alison J. Edwards Ross O. Piltz Iker Del Rosal Laurent Maron Dongmei Cui Jianhua Cheng 《Angewandte Chemie (International ed. in English)》2020,59(28):11250-11255
Hydrogenolysis of alkyl‐substituted cyclopentadienyl (CpR) ligated thorium tribenzyl complexes [(CpR)Th(p‐CH2‐C6H4‐Me)3] ( 1 – 6 ) afforded the first examples of molecular thorium trihydrido complexes [(CpR)Th(μ‐H)3]n (CpR=C5H2(tBu)3 or C5H2(SiMe3)3, n=5; C5Me4SiMe3, n=6; C5Me5, n=7; C5Me4H, n=8; 7 – 10 and 12 ) and [(Cp#)12Th13H40] (Cp#=C5H4SiMe3; 13 ). The nuclearity of the metal hydride clusters depends on the steric profile of the cyclopentadienyl ligands. The hydrogenolysis intermediate, tetra‐nuclear octahydrido thorium dibenzylidene complex [(Cpttt)Th(μ‐H)2]4(μ‐p‐CH‐C6H4‐Me)2 (Cpttt=C5H2(tBu)3) ( 11 ) was also isolated. All of the complexes were characterized by NMR spectroscopy and single‐crystal X‐ray analysis. Hydride positions in [(CpMe4)Th(μ‐H)3]8 (CpMe4=C5Me4H) were further precisely confirmed by single‐crystal neutron diffraction. DFT calculations strengthen the experimental assignment of the hydride positions in the complexes 7 to 12 . 相似文献
63.
Dr. Pelin Sözen‐Aktaş Dr. Iker Del Rosal Dr. Eric Manoury Prof. Funda Demirhan Prof. Agustí Lledós Prof. Rinaldo Poli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(12):3969-3985
The speciation of compounds [Cp*2M2O5] (M=Mo, W; Cp*=pentamethylcyclopentadienyl) in different protic and aprotic polar solvents (methanol, dimethyl sulfoxide, acetone, acetonitrile), in the presence of variable amounts of water or acid/base, has been investigated by 1H NMR spectrometry and electrical conductivity. Specific hypotheses suggested by the experimental results have been further probed by DFT calculations. The solvent (S)‐assisted ionic dissociation to generate [Cp*MO2(S)]+ and [Cp*MO3]? takes place extensively for both metals only in water/methanol mixtures. Equilibrium amounts of the neutral hydroxido species [Cp*MO2(OH)] are generated in the presence of water, with the relative amount increasing in the order MeCN≈acetone<MeOH<DMSO. Addition of a base (Et3N) converts [Cp*2M2O5] into [Et3NH]+[Cp*MO3]?, for which the presence of a N? H???O?M interaction is revealed by 1H NMR spectroscopy in comparison with the sodium salts, Na+[Cp*MO3]?. These are fully dissociated in DMSO and MeOH, but display a slow equilibrium between free ions and the ion pair in MeCN and acetone. Only one resonance is observed for mixtures of [Cp*MO3]? and [Cp*MO2(OH)] because of a rapid self‐exchange. In the presence of extensive ionic dissociation, only one resonance is observed for mixtures of the cationic [Cp*MO2(S)]+ product and the residual undissociated [Cp*2M2O5] because of a rapid associative exchange via the trinuclear [Cp*3M3O7]+ intermediate. In neat methanol, complex [Cp*2W2O5] reacts to yield extensive amounts of a new species, formulated as the mononuclear methoxido complex [Cp*WO2(OMe)] on the basis of the DFT study. An equivalent product is not observed for the Mo system. The addition of increasing amounts of water results in the rapid decrease of this product in favor of [Cp*2W2O5] and [Cp*WO2(OH)]. 相似文献
64.
Iker Montes-Burgos Dorota Walczyk Patrick Hole Jonathan Smith Iseult Lynch Kenneth Dawson 《Journal of nanoparticle research》2010,12(1):47-53
Before commencing any nanotoxicological study, it is imperative to know the state of the nanoparticles to be used and in particular
their size and size distribution in the appropriate test media is particularly important. Particles satisfying standards can
be commercially purchased; however, these invariably cannot be used directly and need to be dispersed into the relevant biological
media. Often such changes in the environment or ionic strength, or a change in the particle concentration, results in some
aggregation or a shift in the particle size distribution. Such unexpected aggregation, dissolution or plating out, if unaccounted
for, can have a significant effect on the available nanoparticle dose and on interpretation of any results obtained thereafter.
Here, we demonstrate the application of characterisation instrumentation that sizes nanoparticles based on their Brownian
motion in suspension. Unlike classical light-scattering techniques, the nanoparticle tracking and analysis (NTA) technique
allows nanoparticles to be sized in suspension on a particle-by-particle basis allowing higher resolution and therefore better understanding of aggregation than ensemble methods (such as dynamic
light scattering (DLS) and differential centrifugation sedimentation (DCS)). Results will be presented from gold (standard)
nanoparticles in biologically relevant media that emphasise the importance of characterisation of the nanoparticle dispersion.
It will be shown how the NTA technique can be extended to multi-parameter analysis, allowing for characterization of particle
size and light scattering intensity on an individual basis. This multi-parameter measurement capability allows sub-populations
of nanoparticles with varying characteristics to be resolved in a complex mixture. Changes in one or more of such properties
can be followed both in real time and in situ. 相似文献