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1.
Molecules ; 28(1)2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36615607

RESUMEN

The chemical immobilization of cobalt(II) ions in a silica aerogel matrix enabled the synthesis of the first representative example of aerogel-based single-ion magnets. For the synthesis of the lyogels, methyl-trimethoxysilane and N-3-(trimethoxysilyl)propyl ethylenediamine were co-hydrolyzed, then the ethylenediamine groups that were immobilized on the silica matrix enabled the subsequent binding of cobalt(II) ions. Lyogels with various amounts of ethylenediamine moieties (0.1-15 mol %) were soaked in isopropanol solutions of cobalt(II) nitrate and further supercritically dried in carbon dioxide to obtain aerogels with a specific surface area of 210-596 m2·g-1, an apparent density of 0.403-0.740 cm3·g-1 and a porosity of 60-78%. The actual cobalt content in the aerogels was 0.01-1.50 mmol per 1 g of SiO2, which could easily be tuned by the concentration of ethylenediamine moieties in the silica matrix. The introduction of cobalt(II) ions into the ethylenediamine-modified silica aerogel promoted the stability of the diamine moieties at the supercritical drying stage. The molecular prototype of the immobilized cobalt(II) complex, bearing one ethylenediamine ligand [Co(en)(MeCN)(NO3)2], was synthesized and structurally characterized. Using magnetometry in the DC mode, it was shown that cobalt(II)-modified silica aerogels exhibited slow magnetic relaxation in a nonzero field. A decrease in cobalt(II) concentration in aerogels from 1.5 mmol to 0.14 mmol per 1 g of SiO2 resulted in a weakening of inter-ion interactions; the magnetization reversal energy barrier likewise increased from 4 to 18 K.


Asunto(s)
Imanes , Dióxido de Silicio , Dióxido de Silicio/química , Cobalto/química , Magnetismo , Etilenodiaminas
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 289: 122228, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36516589

RESUMEN

The abuse of pesticides, antibiotics, organic solvents, etc., not only deteriorates the ecological environment, but even affects the normal development of organisms, posing a serious threat to global public health.Efficient and sensitive detection of pesticides, antibiotics, organic solvents and so on are very important, but also a challenge to scientists. By depositing Ag nanoparticles on the surface of Zn-MOF (1: {[Zn2(bta)(bpy)(H2O)2]·2H2O}n), a new type of composite material (Ag@1) was successfully synthesized and analyzed by TEM, EDS, XPS, XRD, IR and other characterization methods. Ag@1 can serve as multi-response fluorescence sensor to detect pesticides (fluazinam (FLU) and emamectin benzoate (EMB)), Tryptophan (Trp) and Ethylenediamine (EDA). In particular, Ag@1 showed "turn-off" fluorescence sensing for FLU and EDA, and "turn-on" fluorescence sensing for EMB and Trp. It is worth mentioning that we further explored its analysis of FLU and Trp in real water samples and fetal bovine serum. The recoveries are satisfactory, 97.95 % - 102.39 % and 96.69 % - 101.85 %, respectively. In addition, the photocatalytic performance of Ag@1 was found to be excellent, the degradation rate of methylene blue (MB) reached 86 %, and its degradation mechanism was discussed.


Asunto(s)
Nanopartículas del Metal , Plaguicidas , Plata , Triptófano , Fluorescencia , Antibacterianos , Colorantes , Etilenodiaminas , Solventes , Zinc
3.
Int J Mol Sci ; 23(22)2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36430745

RESUMEN

Lipase B from Candida antarctica was immobilized on heterofunctional support octyl agarose activated with vinyl sulfone to prevent enzyme release under drastic conditions. Covalent attachment was established, but the blocking step using hexylamine, ethylenediamine or the amino acids glycine (Gly) and aspartic acid (Asp) altered the results. The activities were lower than those observed using the octyl biocatalyst, except when using ethylenediamine as blocking reagent and p-nitrophenol butyrate (pNPB) as substrate. The enzyme stability increased using these new biocatalysts at pH 7 and 9 using all blocking agents (much more significantly at pH 9), while it decreased at pH 5 except when using Gly as blocking agent. The stress inactivation of the biocatalysts decreased the enzyme activity versus three different substrates (pNPB, S-methyl mandelate and triacetin) in a relatively similar fashion. The tryptophane (Trp) fluorescence spectra were different for the biocatalysts, suggesting different enzyme conformations. However, the fluorescence spectra changes during the inactivation were not too different except for the biocatalyst blocked with Asp, suggesting that, except for this biocatalyst, the inactivation pathways may not be so different.


Asunto(s)
Enzimas Inmovilizadas , Lipasa , Lipasa/metabolismo , Sefarosa/química , Enzimas Inmovilizadas/química , Butiratos , Etilenodiaminas
4.
Dalton Trans ; 51(45): 17170-17179, 2022 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-36314531

RESUMEN

Moderate Zn2+ selectivity over Cd2+ (IZn/ICd = 1.6) in the fluorescence enhancement of TQEN (N,N,N',N'-tetrakis(2-quinolylmethyl)ethylenediamine) was changed to Cd2+ preference via the introduction of a methoxymethyloxy (MOMO) substituent at the 8-position of one of the four quinoline rings (IZn/ICd = 0.2). Thus, 8-MOMOTQEN (N-(8-methoxymethyloxy-2-quinolylmethyl)-N,N',N'-tris(2-quinolylmethyl)ethylenediamine) showed not only high Cd2+-selectivity but also an enhanced fluorescence quantum yield upon Cd2+ binding and high sensitivity for Cd2+ detection as shown by ϕCd = 0.065 and LOD (limit of detection) = 19 nM. The two oxygen atoms of the MOMO group in 8-MOMOTQEN play a crucial role in the fluorescent metal-ion selectivity because the corresponding hydroxy (8-OHTQEN) and methoxy (8-MeOTQEN) derivatives resulted in a poor fluorescent response and metal selectivity, respectively. Another N6O2 ligand, N,N'-bis(8-methoxy-2-quinolylethyl)-N,N'-bis(2-quinolylmethyl)ethylenediamine ((8-MeO)2TQEN) exhibited a Zn2+-selective fluorescence enhancement (IZn/ICd = 2.2), indicating the superiority of the MOMO group for the selective sensing of Cd2+.


Asunto(s)
Cadmio , Éter , Oxígeno , Zinc/química , Colorantes Fluorescentes/química , Cristalografía por Rayos X , Etilenodiaminas/química , Éteres , Sitios de Unión
5.
Molecules ; 27(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36235283

RESUMEN

In this study, C-dots were facilely synthesized via microwave irradiation using citric acid and ethylenediamine as carbon precursors. The fluorescence emissions of the C-dots could be selectively quenched by Fe3+, and the degree of quenching was linearly related to the concentrations of Fe3+ presented. This phenomenon was utilized to develop a sensitive fluorescence assay for Fe3+ detection with broad linear range (0-250, 250-1200 µmol/L) and low detection limit (1.68 µmol/L). Most importantly, the assay demonstrated high reliability towards samples in deionized water, tap water and lake water, which should find potential applications for Fe3+ monitoring in complicated environments.


Asunto(s)
Carbono , Puntos Cuánticos , Ácido Cítrico , Etilenodiaminas , Colorantes Fluorescentes , Lagos , Límite de Detección , Reproducibilidad de los Resultados , Espectrometría de Fluorescencia , Agua
6.
Se Pu ; 40(10): 929-936, 2022 Oct.
Artículo en Chino | MEDLINE | ID: mdl-36222256

RESUMEN

Pesticides are used in the agricultural production process to ensure the yield and quality of agricultural products. However, in recent years, environmental pollution issues caused by pesticide residues have sparked widespread concern in society. It is important to develop convenient and efficient approaches to detect and monitor pesticide residues. In this study, targeting benzoylurea insecticides (BUs), polyamidoamine dendrimer-functionalized silica nanocomposite with polydopamine coating (SiO2-PAMAM-PDA) was designed and successfully synthesized. First, monodisperse silica nanoparticles were prepared by the hydrolysis of tetraethyl orthosilicate (TEOS) in mixed solution of ethanol, water and ammonia. The silane coupling agent (3-aminopropyl)triethoxysilane was then employed to introduce amino groups into the silica. Silica with the zeroth generation of polyamidoamine (PAMAM) modification (SiO2-PAMAM-G0) was obtained through Michael addition reaction of methyl acrylate. Ethylenediamine was added to polymerize with methyl acrylate using an amidation reaction to form the first-generation PAMAM (SiO2-PAMAM-G1). Finally, by polymerizing dopamine under alkaline conditions (pH=8.5), the SiO2-PAMAM-G1 was coated with PDA. Thus, the final product named SiO2-PAMAM-PDA was obtained. The composite was characterized using a transmission electron microscope (TEM) and an increase in surface roughness indicated the successful grafting of PDA coating. Dopamine structure contains abundant benzene rings and amino and hydroxyl groups. It could bind with BUs through multiple secondary interactions, such as hydrogen bond and π-π stacking interaction. Therefore, the introduction of PDA could effectively enhance the affinity of the material toward benzoylurea insecticides. The prepared nanocomposites were used as sorbents in a dispersive micro solid-phase extraction approach (D-µ-SPE). The established approach was employed to extract and enrich the BUs in water samples before high-performance liquid chromatography (HPLC) analysis. Diflubenzuron, triflumuron, hexaflumuron, and teflubenzuron were chosen as target analytes. The following was a typical D-µ-SPE procedure. The prepared adsorbents measuring 40 mg were first dispersed in an 8-mL sample solution containing 150 g/L NaCl. The dispersion was assisted by 120-s vortexing to ensure full contact between the SiO2-PAMAM-PDA and the targets. Next, the adsorbents were separated from the liquid phase by 4-min centrifugation (5000 r/min). Thereafter, the adsorbed benzoylureas were eluted using 1 mL acetonitrile as desorption solvent by 120-s vortexing. Separated by centrifugation, the eluate was dried under a mild nitrogen stream. The solid remains were redissolved in 0.1 mL of acetonitrile, filtered by filter membrane (0.22 µm), and then analyzed by HPLC. The experimental conditions in the D-µ-SPE process could have a great impact on the extraction efficiency. Experimental conditions were optimized using a single factor optimization approach to further enhance the extraction recoveries. The optimized conditions included adsorbent amount, extraction time, desorption solvent type, desorption solvent volume, desorption time, and NaCl addition amount. Under the optimal conditions, a linearity range of 10-500 µg/L and limits of detection (LODs, S/N=3) of 1.1-2.1 µg/L were obtained. The extraction recoveries and relative standard deviations (RSDs) of the four BUs were 82.8%-94.1% and 2.1%-8.0%, respectively. The established approach was compared with reported approaches targeting benzoylurea insecticides. It was discovered that this approach consumed less sample, material, organic solvent, and pretreatment time. It provided a more rapid and green choice for the determination of benzoylurea pesticides. To determine the applicability, the proposed approach was applied to analyze the four benzoylurea insecticides in three river water samples. The real water samples were pretreated using the developed approach ahead of instrumental analysis, and no benzoylurea pesticides residue was detected. Next, standard addition experiments were performed under three spiking levels, including 15, 50, and 200 µg/L. The established approach had good accuracy and feasibility with satisfactory recoveries (69.5%-99.4%) and RSDs (0.2%-9.5%).


Asunto(s)
Dendrímeros , Diflubenzurón , Insecticidas , Nanocompuestos , Residuos de Plaguicidas , Acetonitrilos/análisis , Acrilatos , Amoníaco/análisis , Benceno/análisis , Cromatografía Líquida de Alta Presión , Dendrímeros/análisis , Diflubenzurón/análisis , Dopamina/análisis , Etanol/análisis , Etilenodiaminas/análisis , Indoles , Insecticidas/análisis , Nanocompuestos/análisis , Nitrógeno/análisis , Residuos de Plaguicidas/análisis , Poliaminas , Polímeros , Silanos/análisis , Dióxido de Silicio/análisis , Cloruro de Sodio/análisis , Extracción en Fase Sólida , Solventes/análisis , Agua/análisis
7.
Law Hum Behav ; 46(5): 337-352, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36227319

RESUMEN

OBJECTIVE: In guilty plea hearings, judges must determine whether defendants' plea decisions were made knowingly, intelligently, and voluntarily. Little is known, however, about how plea hearings unfold, especially in juvenile court, where hearings are generally closed to the public. In this study, we had the unique opportunity to systematically observe plea hearings in juvenile and criminal court. HYPOTHESES: We predicted that plea hearings would be brief and that defendant participation, especially among juveniles, would be minimal. We also explored how often judges addressed the plea validity components of knowingness, intelligence, and voluntariness and whether addressing these components differed by the type of court (juvenile, criminal), pretrial custody status, and pled-to charge severity. METHOD: Trained coders in California (n = 104, juvenile court) and Virginia (n = 140, juvenile court; n = 593, criminal court) systematically observed more than 800 guilty plea hearings. Coders reliably documented hearing length, whether the defendant was in pretrial custody, whether the evidence was reviewed, details on defendant participation, and judicial attention to plea validity. RESULTS: On average, juvenile plea hearings lasted about 7 min and criminal plea hearings lasted 13 min. Prosecutors rarely reviewed evidence against the defendants in the juvenile courts, and in one juvenile court, judges paid virtually no attention to plea validity. In the other two courts, certain waived rights (e.g., to trial, to silence) were reviewed consistently. Depending on the court, hearing length and plea validity elements addressed varied by defendants' prehearing custody status and the pled-to charge severity. CONCLUSIONS: These findings provide novel insight into how components necessary for plea admissibility-knowingness, voluntariness, and intelligence-are discussed with defendants and, in doing so, raise concerns about the degree to which plea validity is actively assessed in plea hearings. Plea hearings are formal, minutes-long events in which defendant engagement is low. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Criminales , Derecho Penal , Etilenodiaminas , Culpa , Audición , Humanos , Abogados
8.
Curr Protoc ; 2(10): e559, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36200822

RESUMEN

The reversible oxidation of cysteine thiol groups to sulfenic acid by reactive oxygen species (ROS) such as hydrogen peroxide can impact protein function, activity, and localization. As a consequence, ROS have profound effects on cell functions including proliferation, differentiation, and survival. Furthermore, there are clear associations between the effects of ROS on cells and the etiology of several diseases including cancer and neurodegeneration. In spite of the importance of cysteine sulfenylation as a validated post-translational modification, its labile nature impedes efficient and reproducible detection of proteins with cysteine sulfenic acid residues. To overcome this challenge, we developed a novel cell-permeable bifunctional reagent, consisting of two linked bicyclo[6.1.0]nonyne (BCN) moieties coupled with a short ethylenediamine-derived linker (BCN-E-BCN) that enables the detection of sulfenylated proteins in vitro and in intact cells. The two symmetrical BCN groups allow protein sulfenic acids to be selectively tagged with a BCN at one end while allowing for copper-free click chemistry with azide-tagged reagents of the opposite BCN. In this protocol, the synthesis of BCN-E-BCN and its use to detect cysteine sulfenic acids will be detailed. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Copper-mediated cyclopropanation of 1,5-cyclooctadiene Basic Protocol 2: Synthesis of endo- and exo-bicyclononyne Basic Protocol 3: Synthesis of endo-BCN-E-BCN Basic Protocol 4: BCN-E-BCN treatment of wild-type and cysteine-deficient mutant recombinant cofilin protein Basic Protocol 5: BCN-E-BCN labeling in live cells Basic Protocol 6: Western blotting and visualization of BCN-E-BCN-labeled samples.


Asunto(s)
Azidas , Ácidos Sulfénicos , Factores Despolimerizantes de la Actina , Azidas/química , Reactivos de Enlaces Cruzados , Cisteína/análogos & derivados , Cisteína/metabolismo , Etilenodiaminas , Peróxido de Hidrógeno , Indicadores y Reactivos , Proteínas/química , Especies Reactivas de Oxígeno , Ácidos Sulfénicos/química , Compuestos de Sulfhidrilo
9.
Biosensors (Basel) ; 12(10)2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36291039

RESUMEN

Cellular iron supply is required for various biochemical processes. Measuring bioavailable iron in cells aids in obtaining a better understanding of its biochemical activities but is technically challenging. Existing techniques have several constraints that make precise localization difficult, and the lack of a functional readout makes it unclear whether the tested labile iron is available for metalloproteins. Here, we use geNOps; a ferrous iron-dependent genetically encoded fluorescent nitric oxide (NO) biosensor, to measure available iron in cellular locales. We exploited the nitrosylation-dependent fluorescence quenching of geNOps as a direct readout for cellular iron absorption, distribution, and availability. Our findings show that, in addition to ferrous iron salts, the complex of iron (III) with N,N'-bis (2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) can activate the iron (II)-dependent NO probe within intact cells. Cell treatment for only 20 min with iron sucrose was also sufficient to activate the biosensor in the cytosol and mitochondria significantly; however, ferric carboxymaltose failed to functionalize the probe, even after 2 h of cell treatment. Our findings show that the geNOps approach detects available iron (II) in cultured cells and can be applied to assay functional iron (II) at the (sub)cellular level.


Asunto(s)
Técnicas Biosensibles , Metaloproteínas , Hierro , Óxido Nítrico , Ácido Edético , Sacarato de Óxido Férrico , Sales (Química) , Etilenodiaminas
10.
Chemosphere ; 309(Pt 1): 136657, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36191772

RESUMEN

The mechanism of photolysis of the Fe(III) complex with ethylenediamine-N,N'-disuccinic acid ([FeEDDS]-) was revealed using a combination of time resolved and stationary photochemical methods. Using laser flash photolysis (λex = 355 nm), the formation of the primary intermediate, the radical complex of Fe(II) with quantum yield (φ0 = 0.21) was detected for the first time. The lifetime (1.8 ms) and the spectral characteristics (λmax = 520 nm, ε520 nm = 160 M-1cm-1) of this intermediate were also determined. The dependence of the quantum yield of photolysis of the [FeEDDS]- complex (φFeEDDS) and the hydroxyl radical quantum yield (φOH) on the excitation wavelength, pH, and concentrations of the ligand and iron ions were obtained for the first time. It has been established that under optimal conditions at neutral pH, the value of φFeEDDS is about 0.8, and φOH is about 0.15. It was found that φFeEDDS does not depend on the initial concentrations of Fe(III), EDDS, but depends on pH, the excitation wavelength and the presence of oxygen. φOH does not depend on the initial concentrations of Fe(III), EDDS, but depends on pH and the excitation wavelength. The high φOH values make the [FeEDDS]- complex a suitable system for the generation of •OH radical at neutral pH under UV radiation.


Asunto(s)
Compuestos Férricos , Radical Hidroxilo , Fotólisis , Ligandos , Etilenodiaminas , Hierro , Oxígeno , Compuestos Ferrosos
11.
Ann Nucl Med ; 36(11): 976-985, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36097232

RESUMEN

PURPOSE: In this study, we designed a new linear 6-Hydrazinonicotinamide (HYNIC)-conjugated peptide (HYNIC-KRWrNM) (M-6) and labeled with technetium-99m for gamma imaging of glioblastoma as a αvß3-positive tumor. We evaluated tumor targeting ability of this radio-peptide and compared with previous 99mTc-labeled HYNIC-conjugated RGD analogue peptides. PROCEDURES: One new linear peptide (HYNIC-KRWrNM) (M-6) was designed and labeled with technetium-99m in the presence of 2-[[1,3-dihydroxy-2-(hydroxymethyl) propan-2-yl] amino] acetic acid (Tricine)/Ethylenediamine-N,N'-diacetic acid (EDDA) as co-ligand system. Then, this 99mTc-labeled peptide ([99mTc]Tc-M-7) was evaluated for in vitro stability in saline and serum, specific binding assay, internalization, and binding affinity (Kd). In addition, we performed biodistribution study and planar imaging on nude mice bearing U87-MG xenograft as a αvß3-positive tumor. RESULTS: The radiochemical yield of [99mTc]Tc-M-7 was obtained ˃95%. This 99mTc-labeled peptide remained stable and intact in saline solution after 24 h incubation. In addition, metabolic stability of this 99mTc-labeled peptide was obtained ˃60% after 4 h incubation in serum. The Kd value for [99mTc]Tc-M-7 was obtained 5.2 ± 1.0 nM. Based on biodistribution results in nude mice bearing U87-MG xenograft, tumor/muscle activity ratio was 6.22 and decreased to 1.89 in blocking group at the same time point (4 h p.i.). The blocking experiment results also indicated that tumor uptake and kidney uptake were αvß3-mediated. In comparison with previous HYNIC-conjugated RGD analogue peptides, kidneys had the highest uptake of this 99mTc-labeled peptide (52.29 ± 11.48 at 1.5 h p.i. and 27.04 ± 0.66%ID/g at 4 h p.i.). Finally, similar to previous 99mTc-labeled HYNIC-conjugated RGD analogue peptides, [99mTc]Tc-M-7 showed acceptable tumor uptake after 4 h post-injection (based on ROI technique, target-to-background activity ratio = 3.80). CONCLUSIONS: This small linear 99mTc-labeled peptide, with high affinity to αvß3 integrin, desirable water solubility, and cost efficient, demonstrates a potent tumor targeting ability as well as previous HYNIC-conjugated RGD analogue peptides. Hence, [99mTc]Tc-M-7 can be of service to as a new candidate for early detection of αvß3-positive tumors.


Asunto(s)
Glioblastoma , Compuestos de Organotecnecio , Animales , Humanos , Ratones , Línea Celular Tumoral , Etilenodiaminas , Glioblastoma/diagnóstico por imagen , Integrina alfaVbeta3/metabolismo , Integrina beta3/metabolismo , Ligandos , Ratones Desnudos , Oligopéptidos/metabolismo , Péptidos/metabolismo , Solución Salina , Tecnecio , Distribución Tisular , Tomografía Computarizada de Emisión de Fotón Único
12.
Sci Total Environ ; 853: 158650, 2022 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-36089022

RESUMEN

While ethylenediamine tetramethylenephosphonic acid (EDTMPA) has been emerged as a stronger chelating agent than ethylene diamine tetraacetic acid (EDTA) for fouling mitigation, and transparent exopolymer particles (TEP) is a major foulant in membrane-based water treatment process, effects of EDTMPA on TEP fouling and the underlying mechanism have been not yet studied. In this study, Flory-Huggins lattice theory was combined with density functional theory (DFT) technology to explore this subject at molecular level. Filtration experiments showed a unimodal pattern of specific filtration resistance (SFR) of TEP sample with Ca2+ concentration in range of 0-3 mM. For the TEP sample with the peak SFR value at 1.5 mM Ca2+, continuous addition of EDTMPA (from 0 to 100 mg·L-1) resulted in a sustained decrease in SFR. Energy dispersive spectroscopy (EDS) mapping characterization showed the continuing decline of calcium content in the TEP layer with increase of EDTMPA addition, indicating that EDTMPA successfully captured Ca2+ from alginate­calcium ligation (TEP), and then disintegrated the TEP structure. DFT simulation showed that Ca2+ preferentially coordinated with the terminal carboxyl groups of alginate chains to form a coordination configuration that is conducive to stretch the three-dimensional polymer network. Such a network corresponded to an extremely high SFR according to Flory-Huggins theory. EDTMPA addition caused disintegration of the coordination configuration of Ca2+ binding to terminal carboxyl groups, which further resulted in collapse and flocculation of TEP gel network structure, thus leading to a continuous SFR decrease. This work provided deep thermodynamic insights into effects of EDTMPA on TEP-associated fouling at molecular level, facilitating to better understanding and mitigation of membrane fouling.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas , Purificación del Agua , Membranas Artificiales , Calcio/química , Ácido Edético , Filtración , Alginatos/química , Polímeros/química , Etilenodiaminas , Quelantes , Etilenos
13.
J Org Chem ; 87(18): 11968-11978, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36062357

RESUMEN

A C2-symmetrical bis-thiourea chiral solvating agent (CSA), TFTDA, for NMR spectroscopy has been obtained by reacting (1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine and 3,5-bis(trifluoromethyl)phenyl isothiocyanate. TFTDA shows remarkable propensity to enantiodiscriminate N-trifluoroacetyl (N-TFA) and N-acetyl (N-Ac) derivatives of amino acids with free carboxyl functions, with the co-presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as the third achiral additive, which is needed for substrate solubilization. TFTDA shows enhanced enantiodiscriminating efficiency in comparison with the corresponding monomeric counterpart, TFTMA, pointing out cooperativity between its two symmetrical entities. A wide range of amino acid derivatives have been efficiently enantiodiscriminated in CDCl3, with high enantioresolution quotients, which guarantee high quality in applications devoted to the quantification of enantiomers. High enantiodiscriminating efficiency is maintained also in diluted 5 mM conditions or in the presence of sub-stoichiometric amounts of CSA (0.3 equiv). The role of phenolic hydroxyls in the DABCO-mediated interaction mechanism between TFTDA and the two enantiomeric substrates has been pointed out by means of diffusion-ordered spectroscopy (DOSY) and rotating frame Overhauser effect spectroscopy (ROESY) experiments. A conformational model for both the CSA and its diastereomeric solvates formed with the two enantiomers of N-acetyl leucine has also been conceived on the basis of ROE data in order to give a chiral discrimination rationale.


Asunto(s)
Octanos , Tiourea , Aminas/química , Aminoácidos/química , Etilenodiaminas , Leucina , Espectroscopía de Resonancia Magnética/métodos , Estereoisomerismo
14.
J Org Chem ; 87(19): 13416-13421, 2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36153989

RESUMEN

FR901464 and thailanstatins are potent cytotoxic natural products that share an amine-containing tetrahydropyran ring. We previously reported the synthesis of the tetrahydropyran component. Here, we changed the protecting group for the amine from Boc to tosyl, improving yields and the time economy. A highlight of the revised synthetic scheme is the use of lithium, t-butanol, and ethylenediamine in THF (nontraditional Birch reduction conditions) for the N-detosylation.


Asunto(s)
Aminas , Productos Biológicos , Etilenodiaminas , Litio , Piranos , Compuestos de Espiro , Alcohol terc-Butílico
15.
Int J Mol Sci ; 23(18)2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36142657

RESUMEN

Metal-based enzyme mimics are considered to be acceptable agents in terms of their biomedical and biological properties; among them, iron oxides (Fe3O4) are treated as basement in fabricating heterogeneous composites through variable valency integrations. In this work, we have established a facile approach for constructing Fe3O4@Ag composite through assembling Fe3O4 and Ag together via polyethyleneimine ethylenediamine (PEI) linkages. The obtained Fe3O4@PEI@Ag structure conveys several hundred nanometers (~150 nm). The absorption peak at 652 nm is utilized for confirming the peroxidase-like activity of Fe3O4@PEI@Ag structure by catalyzing 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. The Michaelis-Menten parameters (Km) of 1.192 mM and 0.302 mM show the higher catalytic activity and strong affinity toward H2O2 and TMB, respectively. The maximum velocity (Vmax) value of 1.299 × 10-7 M·s-1 and 1.163 × 10-7 M·s-1 confirm the efficiency of Fe3O4@PEI@Ag structure. The biocompatibility illustrates almost 100% cell viability. Being treated as one simple colorimetric sensor, it shows relative selectivity and sensitivity toward the detection of glucose based on glucose oxidase. By using indocyanine green (ICG) molecule as an additional factor, a remarkable temperature elevation is observed in Fe3O4@PEI@Ag@ICG with increments of 21.6 ∘C, and the absorption peak is nearby 870 nm. This implies that the multifunctional Fe3O4@PEI@Ag structure could be an alternative substrate for formatting acceptable agents in biomedicine and biotechnology with enzymatic and photothermal properties.


Asunto(s)
Glucosa Oxidasa , Polietileneimina , Bencidinas , Etilenodiaminas , Glucosa , Peróxido de Hidrógeno , Verde de Indocianina , Hierro , Peroxidasas , Polietileneimina/química
16.
Am J Cardiol ; 183: 93-98, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-36114020

RESUMEN

Dilated cardiomyopathy associated with lamin A/C (LMNA) gene variants (LMNA-related dilated cardiomyopathy [DCM]) is a life-threatening condition with a high unmet need, accounting for approximately 6% of idiopathic DCM cases. Currently, no disease-specific treatments target the underlying disease mechanism. ARRY-371797 (PF-07265803), a potent, selective, oral, small-molecule inhibitor of the p38α mitogen-activated protein kinase pathway, improved 6-minute walk test (6MWT) distance in 12 patients with symptomatic LMNA-related DCM in a 48-week, open-label, phase 2 study. This long-term extension study examined the safety and efficacy of ARRY-371797 in patients from the phase 2 study. 6MWT, N-terminal pro-B-type natriuretic peptide concentration, and 12-item Kansas City Cardiomyopathy Questionnaire score were assessed at weeks 48, 72, 96, 120, and 144 from phase 2 study baseline. Eight patients enrolled (mean [SD] age, 51 [10] years, 4 male). Mean 6MWT increased by >30 m (>10%) from phase 2 study baseline up to week 120. The decrease in N-terminal pro-B-type natriuretic peptide observed in the phase 2 study was maintained throughout the present study. Twelve-item Kansas City Cardiomyopathy Questionnaire Physical Limitation increased from baseline at all visits except week 96 (range: -0.8 [week 96] to 13.8 [week 120]); results for other domains were variable. Treatment was generally well tolerated; 2 patients discontinued because of causes not considered treatment-related. There were no deaths. ARRY-371797 was generally well tolerated over median (range) 155.7 (61 to 327)-week exposure; evidence suggested preserved exercise capacity over the study period. The ongoing, pivotal, phase 3, randomized, placebo-controlled study REALM-DCM investigates the efficacy and safety of ARRY-371797 (PF-07265803) in LMNA-related DCM. (ClinicalTrials.gov Identifier: NCT02351856).


Asunto(s)
Cardiomiopatía Dilatada , Etilenodiaminas , Indazoles , Adulto , Cardiomiopatía Dilatada/tratamiento farmacológico , Cardiomiopatía Dilatada/genética , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Etilenodiaminas/efectos adversos , Femenino , Humanos , Indazoles/efectos adversos , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Masculino , Persona de Mediana Edad , Proteína Quinasa 14 Activada por Mitógenos , Péptido Natriurético Encefálico , Ensayos Clínicos Controlados Aleatorios como Asunto
17.
Sci Rep ; 12(1): 15580, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36114355

RESUMEN

In crush syndrome, massive muscle breakdown resulting from ischemia-reperfusion muscle injury can be a life-threatening condition that requires urgent treatment. Blood reperfusion into the ischemic muscle triggers an immediate inflammatory response, and neutrophils are the first to infiltrate and exacerbate the muscle damage. Since free zinc ion play a critical role in the immune system and the function of neutrophils is impaired by zinc depletion, we hypothesized that the administration of a zinc chelator would be effective for suppressing the inflammatory reaction at the site of ischemia-reperfusion injury and for improving of the pathology of crush syndrome. A crush syndrome model was created by using a rubber tourniquet to compress the bilateral hind limbs of mice at 8 weeks. A zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylenediamine (TPEN) was administered immediately after reperfusion in order to assess the anti-inflammatory effect of the chelator for neutrophils. Histopathological evaluation showed significantly less muscle breakdown and fewer neutrophil infiltration in TPEN administration group compared with control group. In addition, the expression levels of inflammatory cytokine and chemokine such as IL-6, TNFα, CXCL1, CXCL2, CXCR2, CCL2 in ischemia-reperfusion injured muscle were significantly suppressed with TPEN treatment. Less dilatation of renal tubules in histological evaluation in renal tissue and significantly better survival rate were demonstrated in TPEN treatment for ischemia-reperfusion injury in crush syndrome. The findings of our study suggest that zinc chelators contributed to the resolution of exacerbation of the inflammatory response and attenuation of muscle breakdown in the acute phase after crush syndrome. In addition, our strategy of attenuation of the acute inflammatory reaction by zinc chelators may provide a promising therapeutic strategy not only for crush syndrome, but also for other diseases driven by inflammatory reactions.


Asunto(s)
Quelantes , Síndrome de Aplastamiento , Infiltración Neutrófila , Daño por Reperfusión , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Quelantes/uso terapéutico , Quimiocinas , Síndrome de Aplastamiento/tratamiento farmacológico , Citocinas , Etilenodiaminas , Inflamación/tratamiento farmacológico , Interleucina-6/uso terapéutico , Isquemia/tratamiento farmacológico , Ratones , Músculos/patología , Infiltración Neutrófila/efectos de los fármacos , Reperfusión , Daño por Reperfusión/complicaciones , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/patología , Goma , Factor de Necrosis Tumoral alfa/uso terapéutico , Zinc/farmacología
18.
J Inorg Biochem ; 237: 111994, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36126431

RESUMEN

In this work we report the electrochemical, spectroscopical and spectro-electrochemical studies of a model complex [CuΙΙ(Bztpen)]2+, (Bztpen = (N-benzyl-N,N',N'-tris(pyridin-2-ylmethyl)ethylenediamine) in order to propose a methodology to evaluate the interaction of potential metal based anticancer agents during electron transfer processes, with transport proteins such as Bovine Serum Albumin (BSA). It was possible to establish a reversible electron transfer [CuΙΙ(Bztpen)]2+ +1e â†’ [CuΙ(Bztpen)]+ and a weak interaction energy between BSA and [CuΙΙ(Bztpen)] and [CuΙ(Bztpen)] species, with no adsorption of protein over the electrode surface. Circular Dichroism (CD) Spectroelectrochemistry, not reported before, reveals no significant changes in BSA structure during the electron transfer [CuΙΙ(Bztpen)]2+ + 1e â†’ [CuΙ(Bztpen)]+. CD experiments at variable temperature for BSA denaturalization in the absence and in the presence of [CuΙΙ(Bztpen)]2+, shown no change in thermodynamic parameters due to low interaction between the transport protein and copper complex.


Asunto(s)
Etilenodiaminas , Albúmina Sérica Bovina , Albúmina Sérica Bovina/química , Dicroismo Circular , Espectrometría de Fluorescencia , Cobre/química
19.
Biosens Bioelectron ; 217: 114676, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36126556

RESUMEN

Mercury ion (Hg2+) as a major environmental pollutant threatens human health even at very low concentrations, so it is essential to monitor mercury residues in food. In this study, Hg2+ was conjugated with protein carrier using 1-(4-Isothiocyanobenzyl) ethylenediamine N, N, N', N'-tetraacetic acid (ITCBE) as a bifunctional chelator. 7A1 monoclonal antibody (mAb) against Hg2+-ITCBE with high affinity (7.3 × 109 L/moL) and good specificity was obtained by cell fusion technology and performed to establish immunosensors. Immunochromatographic test strip using colloidal gold nanoparticles (AuNP with an average diameter of 18 nm) as signal reporter showed low sensitivity. Signal amplification probes including larger multi-branched gold nanoflowers (AuNF) and latex microspheres (LM) were employed to enhance the sensitivity of immunosensors. The visible limit of detection (vLOD) of the AuNF- and LM-based strip were determined to be 50 ng/mL and 25 ng/mL respectively, showing more sensitive than that of AuNP-based strip (200 ng/mL). Quantitative analysis showed that AuNF-based strip exhibited lower quantitative limit of detection (qLOD) (0.44 ng/mL) which was 20-fold lower than that of AuNP-based strip (8.92 ng/mL) for determination of Hg2+, and LM-based strip (0.49 ng/mL) was 18 times as sensitive as AuNP-based strip. In summary, the developed immunosensors using AuNF and LM as signal amplification probes exhibited excellent sensitivity and provided portable, on-site detection for Hg2+.


Asunto(s)
Técnicas Biosensibles , Contaminantes Ambientales , Mercurio , Nanopartículas del Metal , Anticuerpos Monoclonales/química , Quelantes , Contaminantes Ambientales/análisis , Etilenodiaminas , Oro/análisis , Oro Coloide , Humanos , Inmunoensayo , Iones/análisis , Látex , Mercurio/análisis , Nanopartículas del Metal/química
20.
Cell Biochem Biophys ; 80(4): 755-761, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36068383

RESUMEN

Zinc ion (Zn2+) is an important functional factor; however, excessive Zn2+ can be toxic. To understand the neurotoxicity of excessive Zn2+ and the underlying mechanism, PC12 cells were treated with excessive Zn2+ and Zn2+ plus N, N, N', N'-Tetrakisethylenediamine (TPEN), a zinc ion chelator agent. Trypan blue and 3-(4,5-dimethyl-2- thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, thiazolyl blue tetrazolium bromide (MTT) assays were used to test cell viability; the relative kits were used to detect the activity of NOS synthase and the content of the receptor for advanced glycation end product (RAGE) in cells. We observed that excessive zinc caused PC12 cell damage and that TPEN partially reversed cell damage caused by excessive zinc. In addition, excessive zinc decreased total nitric oxide synthase (TNOS) activity in cells, in which constitutive nitric oxide synthase (cNOS) activity was significantly reduced; however, inducible nitric oxide synthase (iNOS) activity was extremely promoted. Moreover, excessive zinc upregulated the expression of RAGE, and TPEN effectively reversed the increase in RAGE induced by excessive zinc ions. Therefore, we concluded that excessive zinc caused PC12 cell damage, correlating with the inhibition of NOS and increase of RAGE induced in cells.


Asunto(s)
Azul de Tripano , Zinc , Animales , Bromuros/metabolismo , Muerte Celular , Quelantes/farmacología , Etilenodiaminas , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Células PC12 , Ratas , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Zinc/metabolismo
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