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1.
Sci Rep ; 11(1): 17827, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34497312

RESUMO

Because of their long lifespan, matrix proteins of the vascular wall, such as elastin, are subjected to molecular aging characterized by non-enzymatic post-translational modifications, like carbamylation which results from the binding of cyanate (mainly derived from the dissociation of urea) to protein amino groups. While several studies have demonstrated a relationship between increased plasma concentrations of carbamylated proteins and the development of cardiovascular diseases, molecular mechanisms explaining the involvement of protein carbamylation in these pathological contexts remain to be fully elucidated. The aim of this work was to determine whether vascular elastic fibers could be carbamylated, and if so, what impact this phenomenon would have on the mechanical properties of the vascular wall. Our experiments showed that vascular elastin was carbamylated in vivo. Fiber morphology was unchanged after in vitro carbamylation, as well as its sensitivity to elastase degradation. In mice fed with cyanate-supplemented water in order to increase protein carbamylation within the aortic wall, an increased stiffness in elastic fibers was evidenced by atomic force microscopy, whereas no fragmentation of elastic fiber was observed. In addition, this increased stiffness was also associated with an increase in aortic pulse wave velocity in ApoE-/- mice. These results provide evidence for the carbamylation of elastic fibers which results in an increase in their stiffness at the molecular level. These alterations of vessel wall mechanical properties may contribute to aortic stiffness, suggesting a new role for carbamylation in cardiovascular diseases.


Assuntos
Aorta/fisiologia , Tecido Elástico/metabolismo , Elastina/metabolismo , Rigidez Vascular/fisiologia , Animais , Aorta/efeitos dos fármacos , Bovinos , Cianatos/farmacologia , Tecido Elástico/efeitos dos fármacos , Camundongos , Carbamilação de Proteínas/efeitos dos fármacos , Rigidez Vascular/efeitos dos fármacos
2.
J Org Chem ; 86(17): 11399-11406, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34365792

RESUMO

We report the visible-light-promoted selenocyanation of cyclobutanone oxime esters using potassium selenocyanate in the presence of a fac-Ir(ppy)3 catalyst for the first time. Because of the mild conditions employed and use of readily accessible potassium selenocyanate, this method is an effective and green strategy for the synthesis of cyano and selenocyano bifunctional substituted alkanes.


Assuntos
Ésteres , Oximas , Cianatos , Potássio , Compostos de Selênio
3.
J Phys Chem B ; 125(31): 8907-8918, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34339200

RESUMO

Ultrafast infrared vibrational spectroscopy is widely used for the investigation of dynamics in systems from water to model membranes. Because the experimental observation window is limited to a few times the probe's vibrational lifetime, a frequent obstacle for the measurement of a broad time range is short molecular vibrational lifetimes (typically a few to tens of picoseconds). Five new long-lifetime aromatic selenocyanate vibrational probes have been synthesized and their vibrational properties characterized. These probes are compared to commercial phenyl selenocyanate. The vibrational lifetimes range between ∼400 and 500 ps in complex solvents, which are some of the longest room-temperature vibrational lifetimes reported to date. In contrast to vibrations that are long-lived in simple solvents such as CCl4, but become much shorter in complex solvents, the probes discussed here have ∼400 ps lifetimes in complex solvents and even longer in simple solvents. One of them has a remarkable lifetime of 1235 ps in CCl4. These probes have a range of molecular sizes and geometries that can make them useful for placement into different complex materials due to steric reasons, and some of them have functionalities that enable their synthetic incorporation into larger molecules, such as industrial polymers. We investigated the effect of a range of electron-donating and electron-withdrawing para-substituents on the vibrational properties of the CN stretch. The probes have a solvent-independent linear relationship to the Hammett substituent parameter when evaluated with respect to the CN vibrational frequency and the ipso 13C NMR chemical shift.


Assuntos
Compostos de Selênio , Vibração , Cianatos , Espectrofotometria Infravermelho
4.
Inorg Chem ; 60(17): 12984-12999, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34369772

RESUMO

Three new classes of ionic organoselenium compounds containing cationic benzimidazolium and imidazolium ring systems with selenocyanates as counterions are described. The cyclization of N,N'-disubstituted benzimidazolium and imidazolium bromides having N-(CH2)2-Br and N-(CH2)3-Br groups in the presence of potassium selenocyanate (KSeCN) led to formation of the corresponding selenazolium selenocyanates (21a, 21b, 22a, and 22b) and selenazinium selenocyanates (21c, 21d, 22c, and 22d). However, the open-chain selenocyanates with additional selenocyanate counterions (21e, 21f, 22e, and 22f) were formed from the N,N'-disubstituted benzimidazolium and imidazolium bromides having N-(CH2)6-Br groups. Mechanistic studies were carried out to understand the feasibility of such cyclization processes in the presence of KSeCN. The compounds were studied further for their potencies to catalytically reduce H2O2 in the presence of thiols. Interestingly, the cyclic selenazolium (21a, 21b, 22a, and 22b) and selenazinium compounds (21c, 21d, 22c, and 22d) exhibited significantly higher antioxidant activities than the corresponding acyclic selenocyanates (21f, 22e, and 22f). Selected compounds (22d and 22e) were further evaluated for their potencies in modulating the intracellular level of reactive oxygen species (ROS) in a representative macrophage cell line (RAW 264.7). Owing to the cationic nature of compounds, they may target and scavenge mitochondrial ROS in the cellular medium.


Assuntos
Antioxidantes/farmacologia , Benzimidazóis/farmacologia , Compostos Organosselênicos/farmacologia , Animais , Antioxidantes/síntese química , Benzimidazóis/síntese química , Cianatos/síntese química , Cianatos/farmacologia , Ciclização , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Camundongos , Compostos Organosselênicos/síntese química , Oxirredução , Células RAW 264.7 , Compostos de Selênio/síntese química , Compostos de Selênio/farmacologia
5.
J Steroid Biochem Mol Biol ; 213: 105975, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34418527

RESUMO

It is established that steroid based agents are an example of compounds obtained from natural patterns and are of great importance due to their application in the prevention and treatment of diseases. Selenosteroids are hybrids formed by attaching Se-moiety to a steroid molecule. In these types of hybrids, selenium can be present as selenide or as a part of selenosemicarbazones, isoselenocyanates, selenourea, etc. Attaching a Se-moiety to a biologically active steroid might enhance the biological properties of both fragments. Available literature indicates that these kinds of hybrids demonstrate significant anticancer activity, which renders them interesting in terms of medical use. In this review, we present various methods of synthesis and demonstrate that seleno-steroid compounds are promising molecules for further pharmaceutical application.


Assuntos
Antineoplásicos Hormonais/síntese química , Técnicas de Química Sintética/métodos , Cianatos/síntese química , Compostos Organosselênicos/síntese química , Compostos de Selênio/síntese química , Esteroides/síntese química , Ureia/análogos & derivados , Antineoplásicos Hormonais/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cianatos/farmacologia , Humanos , Concentração Inibidora 50 , Compostos Organosselênicos/farmacologia , Compostos de Selênio/farmacologia , Semicarbazonas/química , Esteroides/farmacologia , Relação Estrutura-Atividade , Ureia/síntese química , Ureia/farmacologia
6.
Int J Phytoremediation ; 23(10): 1030-1040, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33474973

RESUMO

Two strains of the chlorophyte Chlamydomonas reinhardtii, a wild type (WT) and a transgenic strain (C.CYN) contained an exogenous cyanase gene (CYN), were used to investigate the growth and cyanate biosorption capability through the analysis of the adsorption equilibrium isotherm. The potential antioxidants activity of the algal strains was also investigated under cyanate concentration. The antioxidants activity of both C.CYN and WT were enhanced by the application of cyanate.Two adsorption isotherm models and the sorption kinetics were used to check the efficiency of the cyanate removal process. The results showed the biosorbent efficiency of Chlamydomonas in the removal of KCNO from aqueous solution. The C.CYN strain has great efficiency to remove cyanate as compared to the WT. The maximum percentage of cyanate removal was 83.75% for the C.CYN and 50% for the WT as treated with 0.8 mg.ml-1 KCNO. The data were adapted to the nonlinear Langmuir model on the basis of the coefficient of determination. The calculated qmax was 0.54 and 0.42 µg.mg-1 for C.CYN and WT which correlated to the experimental one (0.67 and 0.4 µg.mg-1, respectively). Our data highlight the application of the transgenic algal strain toward the removal of highly toxic materials as cyanate.Novelty statement The main objective of this work is to find out an efficient genetically-modified Chlamydomonas strain to remove the highly toxic cyanate compound from contaminated area. Moreover, to evaluate the biosorption ability of this transgenic strain with its wild one via two adsorption isotherm (the Langmuir and Freundlich) models. Also, to estimate the antioxidants activity of these strains under the cyanate toxicity through four different assays.


Assuntos
Chlamydomonas reinhardtii , Poluentes Químicos da Água , Adsorção , Antioxidantes , Biodegradação Ambiental , Chlamydomonas reinhardtii/genética , Cianatos , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
7.
Acta Trop ; 215: 105801, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33352169

RESUMO

Compounds 1 and 2 (selenocyanate and diselenide derivatives, respectively) were evaluated for their potential use in vivo against visceral leishmaniasis (VL). Both entities showed low cytoxicity in vitro in Vero and Caco-2 cell lines. However, the compounds were not suitable for their oral administration, since they exhibited poor values of intestinal permeability in vitro. Microsomal stability assays did not show any metabolite for compound 1 after 120 min, whereas 2 was highly metabolized by the enzyme CYP450. Thus, the in vivo efficacy of compound 1 was assessed in a murine model of L. infantum VL. The daily i.v. administration of 1 mg/kg of compound 1 during 5 consecutive days reduced parasite load in liver, spleen and bone marrow (99.2%, 91.7% and 61.4%, respectively) compared to non-treated mice. To the best of our knowledge, this is the first time that a selenium compound has been tested in vivo against VL. Thus, this work evidences the possible usefulness of selenocyanate derivatives for the treatment of this disease.


Assuntos
Cianatos/uso terapêutico , Leishmania infantum , Leishmaniose Visceral/tratamento farmacológico , Compostos de Selênio/uso terapêutico , Animais , Células Cultivadas , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos Wistar
8.
Oxid Med Cell Longev ; 2020: 5417024, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33093936

RESUMO

Herein, we report the synthesis of novel selenocyanates and assessment of their effect on the oxidative challenge elicited by hydrogen peroxide (H2O2) in cultured mouse neurons. First, α-methylene-ß-hydroxy esters were prepared as precursors of allylic bromides. A reaction involving the generated bromides and sodium selenocyanate was conducted to produce the desired selenocyanates (3a-f). We next prepared cultures of neurons from 7-day-old mice (n = 36). H2O2 (10-5 M) was added into the culture flasks as an oxidative stress inducer, alone or combined with one of each designed compounds. (PhSe)2 was used as a positive control. It was carried out assessment of lipid (thiobarbituric acid reactive species, 4-hydroxy-2'-nonenal, 8-isoprostane), DNA (8-hydroxy-2'-deoxyguanosine), and protein (carbonyl) modification parameters. Finally, catalase and superoxide dismutase activities were also evaluated. Among the compounds, 3b, 3d, and 3f exhibited the most pronounced pattern of antioxidant activity, similar to (PhSe)2. These novel aromatic selenocyanates could be promising to be tried in most sophisticated in vitro studies or even at the preclinical level.


Assuntos
Cianatos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Compostos de Selênio/farmacologia , 8-Hidroxi-2'-Desoxiguanosina/metabolismo , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Catalase/metabolismo , Células Cultivadas , Cianatos/síntese química , Peróxido de Hidrogênio/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Neurônios/citologia , Neurônios/metabolismo , Compostos de Selênio/síntese química , Superóxido Dismutase/metabolismo
9.
Environ Sci Technol ; 54(19): 11818-11826, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32876440

RESUMO

Isocyanic acid (HNCO) is a potentially toxic atmospheric pollutant, whose atmospheric concentrations are hypothesized to be linked to adverse health effects. An earlier model study estimated that concentrations of isocyanic acid in China are highest around the world. However, measurements of isocyanic acid in ambient air have not been available in China. Two field campaigns were conducted to measure isocyanic acid in ambient air using a high-resolution time-of-flight chemical ionization mass spectrometer (ToF-CIMS) in two different environments in China. The ranges of mixing ratios of isocyanic acid are from below the detection limit (18 pptv) to 2.8 ppbv (5 min average) with the average value of 0.46 ppbv at an urban site of Guangzhou in the Pearl River Delta (PRD) region in fall and from 0.02 to 2.2 ppbv with the average value of 0.37 ppbv at a rural site in the North China Plain (NCP) during wintertime, respectively. These concentrations are significantly higher than previous measurements in North America. The diurnal variations of isocyanic acid are very similar to secondary pollutants (e.g., ozone, formic acid, and nitric acid) in PRD, indicating that isocyanic acid is mainly produced by secondary formation. Both primary emissions and secondary formation account for isocyanic acid in the NCP. The lifetime of isocyanic acid in a lower atmosphere was estimated to be less than 1 day due to the high apparent loss rate caused by deposition at night in PRD. Based on the steady state analysis of isocyanic acid during the daytime, we show that amides are unlikely enough to explain the formation of isocyanic acid in Guangzhou, calling for additional precursors for isocyanic acid. Our measurements of isocyanic acid in two environments of China provide important constraints on the concentrations, sources, and sinks of this pollutant in the atmosphere.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , China , Cianatos/análise , Monitoramento Ambiental , América do Norte
11.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 9): 392-397, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32880586

RESUMO

The unintentional crystallization of contaminant proteins in the place of target recombinant proteins is sporadically reported, despite the availability of stringent expression/purification protocols and of software for the detection of contaminants. Typically, the contaminant protein originates from the expression organism (for example Escherichia coli), but in rare circumstances contaminants from different sources have been reported. Here, a case of contamination from a Serratia bacterial strain that occurred while attempting to crystallize an unrelated protein from Burkholderia pseudomallei (overexpressed in E. coli) is presented. The contamination led to the unintended crystallization and structure analysis of a cyanase hydratase from a bacterial strain of the Serratia genus, an opportunistic enterobacterium that grows under conditions similar to those of E. coli and that is found in a variety of habitats, including the laboratory environment. In this context, the procedures that were adopted to identify the contaminant based on crystallographic data only are presented and the crystal structure of Serrata spp. cyanase hydratase is briefly discussed.


Assuntos
Artefatos , Cristalografia por Raios X/normas , Cianatos/química , Escherichia coli/genética , Hidroliases/ultraestrutura , Sítios de Ligação , Burkholderia pseudomallei/enzimologia , Burkholderia pseudomallei/genética , Cianatos/metabolismo , Escherichia coli/enzimologia , Expressão Gênica , Humanos , Hidroliases/genética , Hidroliases/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Serratia/enzimologia , Serratia/genética , Transgenes
12.
Int J Biol Macromol ; 164: 2380-2388, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795577

RESUMO

Carbamylation is the non-enzymatic reaction between isocyanic acid and macromolecules (mainly proteins) which results in carbamylation-derived products (CDPs) generation, wherein the macromolecules show altered structure and function. In this study, we examined the modifications caused in human serum albumin (HSA) upon interaction with potassium cyanate (KCNO). HSA was incubated with varying concentrations of KCNO for 6 h at 37 °C. The resultant product was characterized by biochemical and biophysical techniques. Among other changes, the carbamylated-HSA showed homocitrulline generation (LC-MS), increase in mass (DLS), and amyloidogenic aggregate formation (Congo red, SEM, TEM). The Gibb's free energy was calculated to be -2.91 to -3.95 kcal mol-1, suggesting that the binding was spontaneous and energetically favourable. The results indicate that in chronic kidney disease patients, elevated levels of isocyanic acid (formed from urea) may modify the albumin structure and lead to its conversion into amyloidogenic aggregates, thus accelerating kidney damage.


Assuntos
Amiloide/química , Agregados Proteicos , Carbamilação de Proteínas , Albumina Sérica Humana/química , Amiloide/ultraestrutura , Cianatos , Humanos , Microscopia Eletrônica , Análise Espectral
13.
Bioorg Med Chem Lett ; 30(17): 127371, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738977

RESUMO

A series of thirty-one selenocompounds covering a wide chemical space was assessed for in vitro leishmanicidal activities against Leishmania infantum amastigotes. The cytotoxicity of those compounds was also evaluated on human THP-1 cells. Interestingly most tested derivatives were active in the low micromolar range and seven of them (A.I.3, A.I.7, B.I.1, B.I.2, C.I.7 C.I.8 and C.II.8) stood out for selectivity indexes higher than the ones exhibited by reference compounds mitelfosine and edelfosine. These leader compounds were evaluated against infected macrophages and their trypanothione reductase (TryR) inhibition potency was measured to further approach the mechanism by which they caused their action. Among them diselenide tested structures were pointed out for their ability to reduce infection rates. Three of the leader compounds inhibited TryR effectively, therefore this enzyme may be implicated in the mechanism of action by which these compounds cause their leishmanicidal effect.


Assuntos
Antiprotozoários/farmacologia , Cianatos/química , Leishmania infantum/efeitos dos fármacos , Compostos de Selênio/química , Antiprotozoários/química , Sobrevivência Celular/efeitos dos fármacos , Cianatos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Leishmania infantum/fisiologia , NADH NADPH Oxirredutases/antagonistas & inibidores , NADH NADPH Oxirredutases/metabolismo , Testes de Sensibilidade Parasitária , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Compostos de Selênio/farmacologia , Relação Estrutura-Atividade , Células THP-1
14.
Molecules ; 25(14)2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32650504

RESUMO

In order to improve the mechanical and dielectric properties of radome cyanate, a synergistic reinforcement method is employed to develop a resin-based ternary-composite with high heat-resistance and preferable radar-band transmission, which is expected to be applied to fabricate radomes capable of resisting high temperature and strong electric field. According to copolymerization characteristics and self-curing mechanism, epoxy resin (EP) and bismaleimide (BMI) are employed as reinforcements mixed into a cyanate ester (CE) matrix to prepare CE/BMI/EP composites of a heat-resistant radome material by high-temperature viscous-flow blending methods under the catalysis of aluminum acetylpyruvate. The crystallization temperature, transition heat, and reaction rate of cured polymers were tested to analyze heat-resistance characteristics and evaluate material synthesis processes. Scanning electron microscopy was used to characterize the micro-morphology of tensile fracture, which was combined with the tensile strength test and dynamic thermomechanical analysis to investigate the composite modifications on tenacity and rigidity. Weibull statistics were performed to analyze the experimental results of the dielectric breakdown field, and the dielectric-polarization and wave-transmission performances were investigated according to alternative current dielectric spectra. Compared with the pure CE and the CE composites individually reinforced by EP or BMI, the CE/BMI/EP composite acquires the most significant amelioration in both the mechanical and electrical insulation performances as indicated by the breaking elongation and dielectric breakdown strength being simultaneously improved by 40%, which are consistently manifested by the obviously increased transverse lines uniformly distributed on the fracture cross-section. Furthermore, the glass-transition temperature of CE/BMI/EP composite reaches the highest values of nearly 300 °C, with the relative dielectric constant and dielectric loss being mostly reduced to less than 3.2 and 0.01, respectively. The experimental results demonstrate that the CE/BMI/EP composite is a highly-qualified wave-transmission material with preferences in mechanical, thermostability, and electrical insulation performances, suggesting its prospective applications in low-frequency transmittance radomes.


Assuntos
Cianatos/química , Resinas Epóxi/química , Teste de Materiais , Temperatura Alta , Propriedades de Superfície
16.
Bioorg Med Chem ; 28(11): 115509, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32354673

RESUMO

The application of a carbon-silicon bioisosteric replacement strategy to find new acaricides with improved properties led to the discovery of Sila-Cyflumetofen 6B, a novel and highly potent acaricide. The essential t-butyl group in the beta-ketonitrile acaricide Cyflumetofen 6A could be swapped with the bioisosteric trimethyl-silyl group with retention of high level acaricidal activity and favourable pharmacological properties. Sila-Cyflumetofen 6B was found to possess similar preferred energy-minimized conformation and electrostatic potential surface compare to Cyflumetofen 6A. Herein we also report the development and application of the first homology model of the spider mite mitochondrial electron transport complex II (succinate ubiquinone oxidoreductase; SQR) and demonstrated that the active metabolite AB-1 of Cyflumetofen 6A and its sila-analogue Sila-AB-1 bind to the Qp site in same binding pose and that both compounds form two H-bonds and a cation-π interaction with Trp 165, Tyr 433 and Arg 279, respectively. Furthermore, we also developed a new mode of action test for spider mite Complex II using cytochrome c as electron acceptor and blocking its re-oxidation by addition of KCN resulting in a sensitive and convenient colorimetric assay. This new method avoids the use of non-specific artificial electron acceptors and allows to measure SQR inhibition in crude extracts of Tetranychus urtice. In this assay Sila-AB-1, the intrinsically active metabolite of Sila-Cyflumetofen, 6A exhibited even a somewhat lower IC50 value than the metabolite of Cyflumetofen AB-1. Synthetic methodologies are described for the preparation of Sila-Cyflumetofen 6B and its active metabolite Sila-AB-1 which enable an efficient synthesis of these compounds in only 5 and 4 steps, respectively, from cheap commercial starting materials. Although the value of carbon-silicon bioisosteric replacements has already be demonstrated in the past it is to the best of our knowledge the first report of a successful application in crop protection research in the last two decades.


Assuntos
Acaricidas/farmacologia , Carbono/química , Desenho de Fármacos , Complexo II de Transporte de Elétrons/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Propionatos/farmacologia , Silício/química , Acaricidas/síntese química , Acaricidas/química , Animais , Cianatos/farmacologia , Relação Dose-Resposta a Droga , Complexo II de Transporte de Elétrons/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Estrutura Molecular , Propionatos/química , Relação Estrutura-Atividade , Tetranychidae/enzimologia
17.
Chemosphere ; 256: 127047, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32446000

RESUMO

Toxic sodium cyanate is always present in cyanide-contaminated waste. A new technology for the efficient decomposition of toxic sodium cyanate by hematite was first proposed in this study. The decomposition of sodium cyanate under various atmospheres has been studied. Studies show that sodium cyanate decomposes above 782 °C in Ar and above 627 °C in air. Sodium cyanate does not decompose even roasted at 400 °C for 120 min in air. Hematite does not promote the decomposition of sodium cyanate in Ar. However, almost all sodium cyanate decomposes efficiently at 400 °C and the mass ration of hematite to sodium cyanate of 1:1 for 30 min in air or oxygen atmosphere. The increased mass ratio of hematite to sodium cyanate and roasting temperature can both favor the efficient decomposition of sodium cyanate. The efficient decomposition of sodium cyanate occurs within 30 min, and it is almost stagnant with the prolongation of roasting time. When roasted in air or oxygen in the presence of hematite, sodium cyanate decomposes to Na2CO3, CO2 and N2 and a small amount of NaNO3 and NOx. The optimal efficient decomposition of sodium cyanate is to roast above 400 °C for 30 min in air or O2 at a mass ration of hematite to sodium cyanate greater than 1:1.


Assuntos
Cianatos/química , Compostos Férricos/química , Modelos Químicos , Atmosfera , Cianetos , Oxigênio , Temperatura
18.
Life Sci ; 251: 117635, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32272179

RESUMO

Molecular structures containing gold, such as auranofin, have been extensively studied in the diagnosis and treatment of many diseases, including cancer treatment. The pharmacological properties of the newly synthesized unique gold-ligand structures have been reported for different cancer cell lines. However, findings on bishydeten-metal salt complexes with gold are rare. In this work, the synthesis of five novel cyanide-bridged coordination compounds having the closed formulae [Ni(bishydeten)][Au(CN)2]2 (1), [Cu(bishydeten)][Au(CN)2]2 (2), [Zn(bishydeten)2Au3(CN)4][Au2(CN)3] (3), [Cd(bishydeten)0,5]2[Au(CN)2]4.2H2O (4), and [Cd(bishydeten)2][Au(CN)2]2 (5) (where bisyhdeten = N,N-bis(2-hydroxyethyl)ethylene diamine), and their characterization by elemental, infrared, ESI-MS, X-ray (for 2) and thermic measurement methods were performed. Complexes 1 and 3 are thermally more stable than the other three complexes. For these, pharmacological adequacies were also tested. The nucleic acid and protein binding affinities of the Au (I) compounds were also estimated by spectroscopic and electrophoretic techniques. Au (I) complexes were identified as strong chemotherapeutic with mild cytotoxicity, and they demonstrated a dose-dependent inhibition on the growth of cancer cells with IC50 at 0.11 to 0.47 µM. Investigation of mechanisms of action on cells revealed that Au (I) compounds managed to inhibit cell migration and led to a decrease in cytoskeletal proteins such as CK7 and CK20. However, Au (I) compounds failed to inhibit DNA topoisomerase I. Overall, and we suggest that potent antiproliferative activity, mild cytotoxicity, good solubility, and micromolar dosage of Au (I) compounds containing bisyhdeten-metal derivatives render them the potential focus of further studies as chemotherapeutic agents.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Cianatos/farmacologia , Ouro/farmacologia , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Chlorocebus aethiops , Cianatos/administração & dosagem , Cianatos/síntese química , Relação Dose-Resposta a Droga , Ouro/administração & dosagem , Humanos , Concentração Inibidora 50 , Neoplasias/patologia , Solubilidade , Células Vero
19.
Sci Rep ; 10(1): 3863, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32123230

RESUMO

Heme-copper oxygen reductases are terminal respiratory enzymes, catalyzing the reduction of dioxygen to water and the translocation of protons across the membrane. Oxygen consumption is inhibited by various substances. Here we tested the relatively unknown inhibition of cytochrome c oxidase (CcO) with isocyanate. In contrast to other more common inhibitors like cyanide, inhibition with cyanate was accompanied with the rise of a metal to ligand charge transfer (MLCT) band around 638 nm. Increasing the cyanate concentration furthermore caused selective reduction of heme a. The presence of the CT band allowed for the first time to directly monitor the nature of the ligand via surface-enhanced resonance Raman (SERR) spectroscopy. Analysis of isotope sensitive SERR spectra in comparison with Density Functional Theory (DFT) calculations identified not only the cyanate monomer as an inhibiting ligand but suggested also presence of an uretdion ligand formed upon dimerization of two cyanate ions. It is therefore proposed that under high cyanate concentrations the catalytic site of CcO promotes cyanate dimerization. The two excess electrons that are supplied from the uretdion ligand lead to the observed physiologically inverse electron transfer from heme a3 to heme a.


Assuntos
Proteínas de Bactérias/química , Cianatos/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Rhodobacter sphaeroides/enzimologia , Domínio Catalítico
20.
Chem Biodivers ; 17(5): e1900603, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32198823

RESUMO

In the present study, twenty-four selenocyanate and diselenide compounds were synthesized and characterized, and their anticancer activities against the human cancer cell lines Caco2, BGC-823, MCF-7 and PC-3 were determined. Interestingly, most of the new compounds were active in reducing the viability of different cancer cell lines. Two compounds exhibited higher promising activities than other derivatives. The most active compound showed the least IC50 values against the four cancer cell lines, particularly to PC-3 with IC50 values below 5 µm. Two compounds were selected to monitor the expression levels of Bcl-2, IL-2 and caspase-3 molecular biomarkers. Interestingly, the two compounds downregulated the Bcl-2 expression levels and upregulated the expression of IL-2 and caspase-3 in PC-3 cells compared to untreated cells. Moreover, most of the synthesized organoselenides exhibited good Gpx-like activities comparable to ebselen. These results appear that introduction of selenocyanate (-SeCN) or diselenides (-Se-Se-) moiety to some carboxy derivatives could serve as a promising launch point for the further design of this type of organic selenium anticancer agent.


Assuntos
Antineoplásicos/farmacologia , Cianatos/farmacologia , Compostos Organosselênicos/farmacologia , Compostos de Selênio/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Cianatos/síntese química , Cianatos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Compostos Organosselênicos/síntese química , Compostos Organosselênicos/química , Compostos de Selênio/síntese química , Compostos de Selênio/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
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