Synthesis and Structural Characterization of Water-Soluble Gold(I) N-Heterocyclic Carbene Complexes. An X-ray Absorption Fine Structure Spectroscopy (XAFS) Study

Fernández, Gabriela Araceli; Picco, Agustín Silvio; Ceolı́n, Marcelo; Chopa, Alicia B.; Silbestri, Gustavo F.

doi:10.1021/om400663a

Cited by 53 publications

(25 citation statements)

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“…[61][62][63][64][65] The synthesis of the Ag(I) precursors of 3 and 4 has been reported previously. [65][66][67][68] However, to date no direct synthetic pathway for 3 has been published. In this study compound 3 was prepared by the straightforward reaction of the respective silver biscarbene complex and equimolar amounts of the transmetalation agent Au(SMe2)Cl.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Characterization of Hydrophilic Gold(I) N-Heterocyclic Carbene (NHC) Complexes as Potent TrxR Inhibitors Using Biochemical and Mass Spectrometric Approaches

et al. 2017

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We report here on the synthesis of a series of mono- and dinuclear gold(I) complexes exhibiting sulfonated bis(NHC) ligands and novel hydroxylated mono(NHC) Au(I) compounds, which were also examined for their biological activities. Initial cell viability assays show strong antiproliferative activities of the hydroxylated mono(NHC) gold compounds (8 > 9 > 10) against 2008 human ovarian cancer cells even after 1 h incubation. In order to gain insight into the mechanism of biological action of the gold compounds, their effect on the pivotal cellular target seleno-enzyme thioredoxin reductase (TrxR), involved in the maintenance of intracellular redox balance, was investigated in depth. The compounds' inhibitory effects on TrxR and glutathione reductase (GR) were studied comparatively, using either the pure proteins or cancer cell extracts. The results show a strong and selective inhibitory effect of TrxR, specifically for the hydroxyl-functionalized NHC gold(I) complexes (8-10). Valuable information on the gold compounds' molecular reactivity with TrxR was gained using the BIAM (biotin-conjugated iodoacetamide) assay and performing competition experiments by mass spectrometry (MS). In good agreement, both techniques suggest the binding affinity of the mono(NHC) Au(I) complexes toward selenols and thiols. Notably, for the first time, bis-carbene formation from mono-carbenes in buffered solution could be observed by MS, which may provide new insights into the speciation mechanisms of bioactive Au(I) NHC complexes. Furthermore, the compounds' interactions with another relevant in cellulo target, namely telomeric G-quadruplex DNA-a higher-order DNA structure playing key roles in telomere function-was investigated by means of FRET melting assays. The lack of interactions with this type of nucleic acid secondary structure support the idea of selective targeting of the hydrophilic Au(I) NHC compounds toward proteins such as TrxR.

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Section: Synthesis and Characterizationmentioning

confidence: 99%

Characterization of Hydrophilic Gold(I) N-Heterocyclic Carbene (NHC) Complexes as Potent TrxR Inhibitors Using Biochemical and Mass Spectrometric Approaches

et al. 2017

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“…On the other hand, C2 and C3 were not stable even at room temperature. Thus, the water-dissolution of both was accompanied—immediately—by a violet coloration [ 71 , 73 ]), we proceed to the Au-NPs synthesis and the study of their stabilization in the presence of sulphonated imidazolium salts L1 , L2 and L3 ( scheme 1 a ), in order to evaluate whether the steric bulk of the substituents influences the stability of these dispersed in water. Also, it is interesting to explore the Au-NPs formation without using the complexes route since it is very time-consuming.…”

Section: Resultsmentioning

confidence: 99%

Gold nanoparticles stabilized with sulphonated imidazolium salts in water and reverse micelles

et al. 2017

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Herein we describe the synthesis of gold nanoparticles (Au-NPs) in presence of sulphonated imidazolium salts [1,3-bis(2,6-diisopropyl-4-sodiumsulfonatophenyl)imidazolium (L1), 1-mesityl-3-(3-sulfonatopropyl)imidazolium (L2) and 1-(3-sulfonatopropyl)imidazolium (L3)] in water and in a confinement environment created by reverse micelles (RMs). The Au-NPs were characterized—with an excellent agreement between different techniques—by UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential. In homogeneous media, the Au-NPs interact with the imidazolium ring and the sulphonate groups were directed away from the NPs' surface. This fact is responsible for the Au-NPs' stability—over three months—in water. Based on the obtained zeta potential values we assume the degree of coverage of the Au-NPs by the imidazolium salts. In n-heptane/sodium 1,4-bis (2-ethylhexyl) sulfosuccinate (AOT)/water RMs, the Au-NPs formed in presence of sulphonated imidazolium salts present different patterns depending on the ligand used as stabilizer. Interestingly, the Au-NPs are more stable in time when the salts are present in AOT RMs (three weeks) in comparison with the same RMs system but in absence of ligands (less than an hour). Clearly, the sulphonated imidazolium salts are very effective Au-NPs stabilizers in a different medium and this generates a plus to be able to use them for multiple purposes.

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“…The gold cation is thought to be the active center in the hydration of phenylacetylene . Hence, the control of the equilibrium concentration of the gold cation in solution should be an effective way to influence the catalytic activity of these catalysts.…”

Section: Resultsmentioning

confidence: 99%

“…As NHC‐AuX compounds are expensive, the recycling of NHC‐AuX catalysts is of great significance and has attracted wide attention . However, the poor stability of NHC‐AuCl compounds makes recycling a big challenge at high temperature.…”

Section: Resultsmentioning

confidence: 99%

Room‐Temperature Hydration of Alkynes Catalyzed by Different Carbene Gold Complexes and their Precursors

Zhang

et al. 2015

ChemCatChem

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The room‐temperature hydration of alkynes catalyzed by NHC‐gold(I) (NHC=N‐heterocyclic carbene), NAC‐gold(I) (NAC=nitrogen acyclic carbene), and isocyanide gold(I) complexes was investigated carefully in the presence of different weakly coordinating anions. NHC(IPr)‐AuCl/KB(C6F5)4 (NHC(IPr)=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) was found to be the most active catalyst at room temperature, and the room‐temperature hydration of different alkynes could be completed in 7 h using only 0.5 mol % NHC(IPr)‐AuCl/KB(C6F5)4. It was further demonstrated that the catalyst system could be simply reused at least six times without a noticeable loss of catalytic activity.

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Synthesis and Structural Characterization of Water-Soluble Gold(I) N-Heterocyclic Carbene Complexes. An X-ray Absorption Fine Structure Spectroscopy (XAFS) Study

Cited by 53 publications

References 74 publications

Characterization of Hydrophilic Gold(I) N-Heterocyclic Carbene (NHC) Complexes as Potent TrxR Inhibitors Using Biochemical and Mass Spectrometric Approaches

Characterization of Hydrophilic Gold(I) N-Heterocyclic Carbene (NHC) Complexes as Potent TrxR Inhibitors Using Biochemical and Mass Spectrometric Approaches

Gold nanoparticles stabilized with sulphonated imidazolium salts in water and reverse micelles

Room‐Temperature Hydration of Alkynes Catalyzed by Different Carbene Gold Complexes and their Precursors

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