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1.
Nature ; 583(7817): 548-553, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32480398

RESUMO

Tertiary stereogenic centres containing one fluorine atom are valuable for medicinal chemistry because they mimic common tertiary stereogenic centres containing one hydrogen atom, but they possess distinct charge distribution, lipophilicity, conformation and metabolic stability1-3. Although tertiary stereogenic centres containing one hydrogen atom are often set by enantioselective desymmetrization reactions at one of the two carbon-hydrogen (C-H) bonds of a methylene group, tertiary stereocentres containing fluorine have not yet been constructed by the analogous desymmetrization reaction at one of the two carbon-fluorine (C-F) bonds of a difluoromethylene group3. Fluorine atoms are similar in size to hydrogen atoms but have distinct electronic properties, causing C-F bonds to be exceptionally strong and geminal C-F bonds to strengthen one another4. Thus, exhaustive defluorination typically dominates over the selective replacement of a single C-F bond, hindering the development of the enantioselective substitution of one fluorine atom to form a stereogenic centre5,6. Here we report the catalytic, enantioselective activation of a single C-F bond in an allylic difluoromethylene group to provide a broad range of products containing a monofluorinated tertiary stereogenic centre. By combining a tailored chiral iridium phosphoramidite catalyst, which controls regioselectivity, chemoselectivity and enantioselectivity, with a fluorophilic activator, which assists the oxidative addition of the C-F bond, these reactions occur in high yield and selectivity. The design principles proposed in this work extend to palladium-catalysed benzylic substitution, demonstrating the generality of the approach.


Assuntos
Carbono/química , Flúor/química , Alcenos/química , Catálise , Cátions , Halogenação , Hidrogênio/química , Irídio/química , Compostos Organofosforados/química , Oxirredução , Paládio/química
2.
Chemosphere ; 251: 126674, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32359720

RESUMO

Dimensionally stable anodes (DSA) have been widely used to degrade organic compounds because these surfaces promote the electrogeneration of active chlorine species in the bulk of the solution, as well as in the vicinity of the anode when NaCl is used as supporting electrolyte. In this work, the nanoparticles synthesis of IrO2 and RuO2 was performed to obtain two types of DSA electrodes named Class I and II to degrade oxamic acid. For Class I and II DSA, the nanoparticles used were synthesized separately and in the same reaction medium, respectively. Electrolysis were carried out in an open cylindrical cell without division at 25 °C, DSAs were used as anodes and a stainless-steel electrode as cathode, both elements have a geometric area of 2.8 cm2 immersed in 0.05 mol L-1 of NaCl or Na2SO4 and a current density of 3 mA cm-2 was applied for 6 h. Active chlorine species generated in the absence of oxamic acid in NaCl were also detected and quantified through ion chromatography. In Na2SO4 there was no degradation of the compound, but in NaCl the oxamic acid concentration reaching 85% with Class I DSA. The same tendency is observed in mineralization, in which Class I DSA allowed reaching a CO2 transformation close to 73%. The difference in the results occurs because with Class I DSA, more hypochlorite is generated than with Class II and therefore there is a larger amount of oxidizing species in the solution that enables the degradation and mineralization of oxamic acid.


Assuntos
Irídio/química , Modelos Químicos , Ácido Oxâmico/química , Compostos de Rutênio/química , Cloro/análise , Eletrodos , Eletrólise/métodos , Nanopartículas , Oxirredução , Poluentes Químicos da Água/análise
3.
Nat Commun ; 11(1): 2528, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32433521

RESUMO

Arene dearomatization reactions are an important class of synthetic technologies for the rapid assembly of unique chemical architectures. Herein, we report a catalytic protocol to initiate a carboamination/dearomatization cascade that proceeds through transient sulfonamidyl radical intermediates formed from native sulfonamide N-H bonds leading to 1,4-cyclohexadiene-fused sultams. Importantly, this work demonstrates a facile approach to employ two-dimensional aromatic compounds as modular building blocks to generate richly substituted, three-dimensional compounds. These reactions occur at room temperature under visible light irradiation and are catalyzed by the combination of an iridium(III) photocatalyst and a dialkyl phosphate base. Reaction optimization, substrate scope, mechanistic features, and synthetic applications of this transformation are presented.


Assuntos
Radicais Livres/química , Irídio/química , Catálise/efeitos da radiação , Ligação de Hidrogênio , Luz , Estrutura Molecular , Fosfatos/química , Sulfonamidas/química
4.
Dalton Trans ; 49(11): 3562-3569, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123890

RESUMO

The combination of chemotherapeutic and photodynamic activities in an iridium-based molecular compound is less reported. Herein, two iridium complexes (IrC1 and IrC2) with ß-carboline alkaloid ligands were designed and synthesized. Both complexes exhibited high anticancer activities with IC50 values of around 1 µM in the dark against several cell lines tested. Notably, the cytotoxicity of these two complexes against lung cancer (A549) cells increased significantly under light (425 nm) irradiation, with phototoxicity index (PI) values of 120 and 93, respectively. They were specifically enriched in the mitochondria. Cell-based assays demonstrated that IrC1 induced an increase in intracellular reactive oxygen species (ROS) levels, reduction in ATP production, mitochondrial DNA damage, an increase in lipid peroxidation levels, and proteasomal activity inhibition. Under light conditions (in some cases a two-photon laser was also applied), these effects were greatly enhanced. Overall, we have demonstrated that these iridium complexes have dual activities of chemotherapy and photodynamic therapy, which may help to design new metal-based anticancer agents for combined chemo-photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Irídio/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Dano ao DNA , DNA Mitocondrial/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Irídio/química , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química
5.
J Med Chem ; 63(8): 4005-4021, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32207946

RESUMO

Six complexes of formula [Ir(η5:κ1-C5Me4CH2py)(C,N)]PF6, where C5Me4CH2py is 2-((2,3,4,5-tetramethylcyclopentadienyl)methyl)pyridine, and C,N is 2-phenylpyridine (1), 7,8-benzoquinoline (2), 1-phenylisoquinoline (3), 2-(p-tolyl)pyridine (4), 4-chloro-2-phenylquinoline (5), or 2-(2,4-difluorophenyl)pyridine (6), have been synthesized. The cyclopentadienyl ligand bears a tethered pyridine that binds to the metal center, resulting in an Ir(η5:κ1-C5Me4CH2pyN) tether-ring structure, as confirmed by the X-ray crystal structures of 1, 2, 4, 5, and 6. Nontether versions of 1 and 2 were synthesized to aid unambiguous correlation between structure and activity. While nontether complexes are highly potent toward MCF7 cancer cells (similar to cisplatin), complexes bearing the tether-ring structure, 1-6, are exceptionally more potent (1-2 orders of magnitude). Additionally, 1-6 disrupt mitochondrial membrane potential (ΔΨm) and induce oxidative stress. Internalization studies strongly correlate intracellular accumulation and anticancer activity in tether and nontether complexes. We present a new class of organo-iridium drug candidates bearing a structural feature that results in a leap in anticancer potency.


Assuntos
Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Irídio/química , Antineoplásicos/farmacologia , Proliferação de Células/fisiologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Cristalografia por Raios X/métodos , Relação Dose-Resposta a Droga , Células HCT116 , Humanos , Irídio/farmacologia , Células MCF-7 , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo
6.
Chem Commun (Camb) ; 56(22): 3333-3336, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32090227

RESUMO

Facile access to quaternary α-trifluoromethyl α-amino acids has been developed. This sequential reaction involves an Ir-catalyzed asymmetric allylation of α-trifluoromethyl aldimine esters followed by an unprecedented kinetic resolution.


Assuntos
Aminoácidos/química , Irídio/química , Aminoácidos/síntese química , Catálise , Cristalografia por Raios X , Iminas/química , Cinética , Conformação Molecular , Estereoisomerismo
7.
Mikrochim Acta ; 187(2): 110, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31916015

RESUMO

The authors describe a peroxidase-mimicking nanozyme composed of IrO2 and graphene oxide (GO). It was synthesized from monodisperse IrO2 nanoparticles with an average diameter of 1.7 ± 0.3 nm that were prepared by pulsed laser ablation in ethanol. The nanoparticles were then placed on polyallylamine-modified GO nanosheets through electrostatic interaction. The peroxidase-like activity of the resulting nanocomposites was evaluated by catalytic oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of H2O2. Kinetic results demonstrated that the catalytic behavior of the nanocomposites follows Michaelis-Menten kinetics. Experiments performed with terephthalic acid and cytochrome C confirmed that the peroxidase-like activity originated from the electron transfer mechanism rather than from generation of hydroxy radicals. The peroxidase-like activity is inhibited in the presence of ascorbic acid (AA). Based on this property, a colorimetric assay was developed for the determination of AA by exploiting the peroxidase-like activity of IrO2/GO nanocomposites. The linear relationship between absorbance at 652 nm and the concentration of AA was acquired. The limit of detection for AA is 324 nM. Further applications of the method for AA detection in real samples were also successfully demonstrated. Graphical abstractSchematic of the preparation of polyallylamine (PAH)-stabilized IrO2/GO nanocomposites and the colorimetric detection of AA based on the peroxidase-like activity of IrO2/GO nanocomposites.


Assuntos
Ácido Ascórbico/análise , Grafite/química , Irídio/química , Nanopartículas Metálicas/química , Poliaminas/química , Ácido Ascórbico/química , Benzidinas/química , Catálise , Colorimetria/métodos , Corantes/química , Peróxido de Hidrogênio/química , Limite de Detecção , Nanocompostos/química , Oxirredução , Peroxidase/química
8.
Inorg Chem ; 59(4): 2426-2433, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-31977196

RESUMO

The development of new photoactive metal complexes that can trigger oxidative damages to the genetic material is of great interest. In the present paper, we describe the detailed study of a highly photo-oxidant iridium(III) complex that triggers photoinduced electron transfer (PET) with purine DNA bases. The PET has been studied by luminescence and laser flash photolysis experiments. From plasmid DNA agarose gel electrophoresis experiments, we demonstrated the high ability of the iridium complex to induce strand breaks upon light irradiation. Reactive oxygen species (ROS)-specific scavengers and stabilizers were employed to identify that the photocleavage process, the results of which infer singlet oxygen and hydrogen peroxide as the predominant species. To the best of our knowledge, the present work represents one of the few study for highly photo-oxidant bis-cyclometalated iridium(III) complex toward DNA.


Assuntos
Complexos de Coordenação/química , DNA/química , Complexos de Coordenação/efeitos da radiação , Quebras de DNA/efeitos dos fármacos , Peróxido de Hidrogênio/química , Irídio/química , Irídio/efeitos da radiação , Luz , Oxirredução , Oxigênio Singlete/química
9.
Environ Pollut ; 259: 113801, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31891908

RESUMO

Via the thermal sintering, a nanocrystalline IrO2 coating was formed on the Ti substrate to successfully prepare a Ti/IrO2 electrode. Based on the electrochemical analysis, the prepared Ti/IrO2 electrode was found to have powerful oxidation effect on the organics in the TNT red water, where the nitro compound was oxidized through an irreversible electrochemical process at 0.6 V vs. SCE. According to the analysis of the nitro compound content, the UV-vis spectra, and the FTIR spectra of 2,4,6-trinitrotoluene (TNT) red water with electrolytic periods, the degradation mechanism of the dinitrotoluene sulfonate (DNTS) was developed. And the intermediates were characterized by UPLC-HRMS. The DNTS mainly occurred one electron transfer reaction on the Ti/IrO2 electrode. At the early stage of the electrolysis, the polymerization of DNTS was mainly dominated. The generated polymer did not form a polymer film on the electrode surface, but instead it promoted a further reduction. After electrolyzing for 30 h, all NO2 function group in the TNT red water was degraded completely.


Assuntos
Trinitrotolueno/química , Poluentes Químicos da Água/química , Eletrodos , Irídio/química , Oxirredução , Titânio , Eliminação de Resíduos Líquidos , Água
10.
Molecules ; 25(2)2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31940938

RESUMO

Benz(o)hydrazide (BH) is the basic aryl hydrazide; aryl hydrazides have been pursued in the course of drug discovery. Oxidations of BH and phenylacetic hydrazide (PAH) by hexachloroiridate(IV) ([IrCl6]2-) were investigated by use of stopped-flow spectral, rapid spectral scan, RP-HPLC and NMR spectroscopic techniques. The oxidation reactions followed well-defined second-order kinetics and the observed second-order rate constant k' versus pH profiles were established over a wide pH range. Product analysis revealed that BH and PAH were cleanly oxidized to benzoic acid and phenylacetic acid, respectively. A reaction mechanism was proposed, resembling those suggested previously for the oxidations of isoniazid (INH) and nicotinic hydrazide (NH) by [IrCl6]2-. Rate constants of the rate-determining steps were evaluated, confirming a huge reactivity span of the protolysis species observed previously. The enolate species of BH is extremely reactive towards reduction of [IrCl6]2-. The determined middle-ranged negative values of activation entropies together with rapid scan spectra manifest that an outer-sphere electron transfer is probably taking place in the rate-determining steps. The reactivity of neutral species of hydrazides is clearly not correlated to the corresponding pKa values of the hydrazides. On the other hand, a linear correlation, logkenolate = (0.16 ± 0.07)pKenol + (6.1 ± 0.8), is found for the aryl hydrazides studied so far. The big intercept and the small slope of this correlation may pave a way for a rational design of new antioxidants based on aryl hydrazides. The present work also provides the pKa values for BH and PAH at 25.0 °C and 1.0 M ionic strength which were not reported before.


Assuntos
Hidrazinas/química , Irídio/química , Fenilacetatos/química , Ácido Benzoico/química , Concentração de Íons de Hidrogênio , Cinética , Oxirredução , Soluções , Relação Estrutura-Atividade
11.
Artigo em Inglês | MEDLINE | ID: mdl-31983279

RESUMO

An Ir(III) polypyridyl complex-conjugated 14-mer oligonucleotide (IrIII-DNA) was synthesized and its hybridization properties with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) were evaluated by UV-melting experiments. The stabilities of the duplexes of IrIII-DNA with 14-, 20-, and 26-mer ssDNAs were higher than those of the unconjugated oligonucleotides. The triplex of IrIII-DNA with 14-mer dsDNA was also stabilized. However, the triplexes of IrIII-DNA with 20- and 26-mer dsDNAs, flanked by 3 and 6 base pairs at the both ends of 14-mer dsDNA target, were destabilized. This is presumably because of steric repulsion between the Ir(III) complex and the protruding 3- and 6-mer dsDNA moieties which are inflexible compared to ssDNA.


Assuntos
Técnicas de Química Sintética , Irídio/química , Hibridização de Ácido Nucleico , Oligonucleotídeos/química , Sondas de DNA , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Conformação de Ácido Nucleico , Oligonucleotídeos/síntese química , Oligonucleotídeos/efeitos da radiação
12.
Dalton Trans ; 49(6): 1864-1872, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-31967143

RESUMO

Organometallic complexes have important application in the field of protein staining, with potential for use in proteomic analysis. The rational synthesis of a trinuclear luminescent organometallic complex with two platinum(ii) centres appended to the cyclometalated ligand of the iridium(iii) centre is reported here. Two di-2-picolylamine groups bonded to the cyclometalated phenyl pyridine moiety provide three coordinating sites to each platinum centre. The replacement of chloride in the fourth coordination site of two square planar platinum metal centres with the imidazole nitrogen or sulphur atom of histidine/cysteine is evident from the change in luminescence intensity upon binding these amino acids. The increase in luminescence emission intensity upon binding of histidine to the organometallic complex allowed it to be used as a protein staining agent. Reversibility of staining upon washing with imidazole enhances the possibility of its application in mass spectrometric analysis.


Assuntos
Complexos de Coordenação/química , Irídio/química , Substâncias Luminescentes/química , Proteínas/análise , Complexos de Coordenação/síntese química , Imidazóis/síntese química , Imidazóis/química , Luminescência , Substâncias Luminescentes/síntese química , Modelos Moleculares , Coloração e Rotulagem
13.
Chem Commun (Camb) ; 56(13): 2012-2015, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31961351

RESUMO

Here, we describe one simple Ir/hydrosilane catalytic system for chemoselective isomerization of 2-substituted allylic ethers. This facile strategy shows high efficiency towards a variety of substrates, including derivatives from bioactive molecules. The substituent at the α position of the olefins is supposed to be critical in retarding the alkene hydrosilylation process and leading the reaction to go through the isomerization pathway.


Assuntos
Éteres/química , Irídio/química , Silanos/química , Alcenos/química , Catálise , Complexos de Coordenação/química , Isomerismo
14.
Talanta ; 209: 120516, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892012

RESUMO

Monitoring hypochlorite anion (ClO-) in living cells is particularly meaningful and valuable, because over-exposure of the ClO- may cause a potential health hazard towards animals and humans. Considering the special structure and properties of the gemini surfactant, a novel amphiphilic gemini-iridium complex Ir[(ppy-iso)2(bpy-tma2Br2)] (Ir-iso) with isoniazide as a recognition site for ClO- was designed. The Ir-iso possessed an excellent water-solubility as well as a strong ClO- binding capacity, as revealed from the rapid response of emission signal towards ClO-. It was worth noting that such probe had a highly-specific selectivity with a low detection limit (20.5 nM) and was suitable in physiological environment. The cell viability assay, cell imaging, and co-location studies further proved that the Ir-iso had little cytotoxicity and was specifically localized in the mitochondria of breast cancer cells, being a promising candidate of chemo-sensor to detect the endogenous ClO- in living cells.


Assuntos
Complexos de Coordenação/química , Ácido Hipocloroso/análise , Isoniazida/análogos & derivados , Substâncias Luminescentes/química , Mitocôndrias/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/toxicidade , Irídio/química , Isoniazida/síntese química , Isoniazida/toxicidade , Limite de Detecção , Substâncias Luminescentes/síntese química , Substâncias Luminescentes/toxicidade , Medições Luminescentes/métodos , Camundongos , Microscopia Confocal/métodos
15.
Inorg Chem ; 59(1): 748-758, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31808678

RESUMO

The rational design by the introduction of fluorine into a compound has achieved success in the development of organic anticancer drugs. However, the fluorine effect in metal-based anticancer complexes has rarely been reported. In this contribution, we report the synthesis, characterization, chemical reactivity, and biological activity of a series of half-sandwich zwitterionic iridium(III) complexes containing different substituents in the η5-CpR ring. The molecular structures for complexes Ir1-Ir4 and Ir7 were determined by single-crystal X-ray crystallography techniques. Notably, the asymmetrically substituted fluoro complexes Ir4 and Ir6 in solution show two conformational isomers. These complexes have sufficient stability, exhibit fluorescence emission, and show potent catalytic activity in converting NADH to NAD+. The effect of the substituents in the η5-CpR ring for these zwitterionic complexes on their anticancer activity was systematically investigated. Surprisingly, the presence of fluorinated substituents gives rise to a significant increase in the anticancer activity. The lipophilicity and cellular uptake levels of these complexes appeared to be the primary factors for their cytotoxicity in this system. A microscopic mechanism study showed that the typical complex Ir4 entered A549 cancer cells through an energy-dependent pathway and was mainly located in lysosomes. Furthermore, an increase in ROS level, apoptosis induction, and cell-cycle perturbation together contribute to the anticancer potency of these zwitterionic complexes.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Flúor/química , Irídio/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/química , Cisplatino/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Irídio/química , Modelos Moleculares , Estrutura Molecular , Espécies Reativas de Oxigênio/análise
16.
Chem Commun (Camb) ; 56(5): 762-765, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31845680

RESUMO

A multifunctional photodynamic therapy (PDT) nanoplatform, characterized by red-shifted absorption and emission, was fabricated using an UiO-66-based metal-organic framework (MOF), a biscyclometalated iridium(iii) complex, and a pH/ROS-responsive polycationic polymer. Noticeably, this promising nanoplatform exhibited good biocompatibility in the dark and produced abundant ROS upon light irradiation, which could achieve apparent endo/lysosome escape and kill cancer cells effectively.


Assuntos
Resinas Acrílicas/farmacologia , Complexos de Coordenação/farmacologia , Estruturas Metalorgânicas/farmacologia , Nanopartículas/química , Fármacos Fotossensibilizantes/farmacologia , Resinas Acrílicas/química , Resinas Acrílicas/toxicidade , Complexos de Coordenação/química , Complexos de Coordenação/toxicidade , Desenho de Fármacos , Células HeLa , Humanos , Irídio/química , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/toxicidade , Microscopia de Fluorescência/métodos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/toxicidade , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Compostos de Amônio Quaternário/toxicidade , Espécies Reativas de Oxigênio/metabolismo
17.
Talanta ; 208: 120372, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816688

RESUMO

Inspired by the structure and properties of gemini surfactant, a novel amphiphilic gemini-iridium complex (GIC-Ir) has been developed, which can spontaneously form vesicles by self-assembly and exhibit excellent dispersibility and high emission intensity in water. The emission of GIC-Ir can be rapidly and selectively quenched by picric acid (PA) due to the aromatic groups and two long-chain quaternary ammonium (QA) groups with positive charge, which endow GIC-Ir vesicles outstanding capability to capture negatively charged PA, and greatly promote the interaction between GIC-Ir and PA. Theoretical calculations and spectral studied indicated that the photoinduced electron transfer and resonance energy transfer may be responsible to the emission quenching. Furthermore, the real water samples and in vitro studies further prove that GIC-Ir can be used as a promising chemosensor for the detection of PA both in water and intracellular.


Assuntos
Calcitriol/análogos & derivados , Complexos de Coordenação/química , Interações Hidrofóbicas e Hidrofílicas , Espaço Intracelular/química , Irídio/química , Picratos/análise , Água/química , Calcitriol/química , Células Hep G2 , Humanos , Limite de Detecção , Fatores de Tempo
18.
Chem Commun (Camb) ; 55(96): 14442-14445, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31724668

RESUMO

We firstly perpared liposome coated [Ir(pq)2(bpy)]Cl (Ir@liposome) as a transducer for radiopharmaceutical (18F-FDG) excited phosphorescence imaging (REPI). Ir@liposome-based REPI exhibited deep tissue penetration and high signal-to-noise ratio in the tumor.


Assuntos
Complexos de Coordenação/química , Irídio/química , Nanopartículas/química , Imagem Óptica/métodos , Compostos Radiofarmacêuticos/química , Animais , Linhagem Celular Tumoral , Fluordesoxiglucose F18/química , Humanos , Lipossomos/química , Camundongos , Razão Sinal-Ruído
19.
Mikrochim Acta ; 186(12): 841, 2019 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-31768640

RESUMO

A luminescent microRNA nanoprobe based on the target-triggered Ir(III)-solvent complex release has been fabricated. The complex is initially embedded into mesoporous silica nanoparticles (MSNs), and then is capped by single-stranded (ss) DNA. In the presence of the target microRNA, the ssDNA hybridize with the microRNA forming a rigid DNA/RNA heteroduplexes and leaving the surface of MSN. Thus, the capped Ir(III) solvent complex is released and re-coordinated with histidine (His) to form a new luminescent complex. The luminescence intensity of the nascent complex (with excitation/emission maxima at 340/570 nm) is positively correlated with the concentrations of the target microRNA in the range from 0.05 to 2 nM, and the detection limit of microRNA is estimated as 0.2 pM (S/N = 3). The ability of this nanoprobe to detect microRNA in cell extract further demonstrates its potential in practical application. Graphical abstractSchematic of a luminescent microRNA nanoprobe based on the target-triggered release of an Ir(III)-solvent complex from mesoporous silica nanoparticles.


Assuntos
Complexos de Coordenação/química , Substâncias Luminescentes/química , MicroRNAs/química , Nanopartículas/química , Dióxido de Silício/química , Acetonitrilos/química , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Histidina/química , Humanos , Irídio/química , Limite de Detecção , Medições Luminescentes/métodos , Células MCF-7 , MicroRNAs/genética , Hibridização de Ácido Nucleico , Porosidade , Estudo de Prova de Conceito
20.
Inorg Chem ; 58(23): 15917-15926, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31714764

RESUMO

A range of novel cyclometalated ruthenium(II) and iridium(III) complexes with a steroidal backbone based on androsterone were synthesized and characterized by NMR spectroscopy and X-ray crystallography. Their cytotoxic properties in RT112 and RT112 cP (cisplatin-resistant) cell lines as well as in MCF7 and somatic fibroblasts were compared with those of the corresponding nonsteroidal complexes and the noncyclometalated pyridyl complexes as well as with cisplatin as reference. All steroidal complexes were more active in RT112 cP cells than cisplatin, whereby the cyclometalated pyridinylphenyl complexes based on 5c showed high cytotoxicity while maintaining low resistant factors of 0.33 and 0.50.


Assuntos
Androstenóis/farmacologia , Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Irídio/farmacologia , Rutênio/farmacologia , Androstenóis/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Irídio/química , Ligantes , Modelos Moleculares , Estrutura Molecular , Rutênio/química , Relação Estrutura-Atividade
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