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1.
Nano Lett ; 24(17): 5197-5205, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38634879

RESUMO

Highly active nonprecious-metal single-atom catalysts (SACs) toward catalytic transfer hydrogenation (CTH) of α,ß-unsaturated aldehydes are of great significance but still are deficient. Herein, we report that Zn-N-C SACs containing Zn-N3 moieties can catalyze the conversion of cinnamaldehyde to cinnamyl alcohol with a conversion of 95.5% and selectivity of 95.4% under a mild temperature and atmospheric pressure, which is the first case of Zn-species-based heterogeneous catalysts for the CTH reaction. Isotopic labeling, in situ FT-IR spectroscopy, and DFT calculations indicate that reactants, coabsorbed at the Zn sites, proceed CTH via a "Meerwein-Ponndorf-Verley" mechanism. DFT calculations also reveal that the high activity over Zn-N3 moieties stems from the suitable adsorption energy and favorable reaction energy of the rate-determining step at the Zn active sites. Our findings demonstrate that Zn-N-C SACs hold extraordinary activity toward CTH reactions and thus provide a promising approach to explore the advanced SACs for high-value-added chemicals.

2.
FASEB J ; 36(6): e22340, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524736

RESUMO

The prevention role of Lactiplantibacillus plantarum against the formation of kidney stones has been increasingly recognized; its mechanism, however, has mainly been focused on inhibiting the inflammation in the colon in the gastrointestinal (GI) system, and the intestinal metabolites from microflora have not been revealed fully with regarding to the stone formation. In this study, we investigated the effect of L. plantarum J-15 on kidney stone formation in renal calcium oxalate (CaOx) rats induced by ethylene glycol and monitored the changes of intestinal microflora and their metabolites detected by 16S rRNA sequencing and widely targeted analysis, followed by the evaluation of the intestinal barrier function and inflammation levels in the colon, blood and kidney. The results showed that L. plantarum J-15 effectively reduced renal crystallization and urinary oxalic acid. Ten microbial genera, including anti-inflammatory and SCFAs-related Faecalibaculum, were enriched in the J-15 treatment group. There are 136 metabolites from 11 categories significantly different in the J-15 supplementation group compared with CaOx model rats, most of which were enriched in the amino acid metabolic and secondary bile acid pathways. The expression of intestinal tight junction protein Occludin and the concentration of pro-inflammatory cytokines and prostaglandin were decreased in the intestine, which further reduced the translocated lipopolysaccharide and inflammation levels in the blood upon J-15 treatment. Thus, the inflammation and injury in the kidney might be alleviated by downregulating TLR4/NF-κB/COX-2 signaling pathway. It suggested that L. plantarum J-15 might reduce kidney stone formation by restoring intestinal microflora and metabolic disorder, protecting intestinal barrier function, and alleviating inflammation. This finding provides new insights into the therapies for renal stones.


Assuntos
Microbioma Gastrointestinal , Cálculos Renais , Animais , Oxalato de Cálcio/metabolismo , Feminino , Humanos , Inflamação/metabolismo , Cálculos Renais/induzido quimicamente , Cálculos Renais/prevenção & controle , Lactobacillaceae/genética , Lactobacillaceae/metabolismo , Masculino , RNA Ribossômico 16S/genética , Ratos
3.
Pharmacol Res ; 187: 106586, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36460280

RESUMO

Over the past few decades, the treatment of atherosclerotic cardiovascular disease has mainly been through an LDL lowering strategy and treatments targeting other traditional risk factors for atherosclerosis, which has significantly reduced cardiovascular mortality. However, the overall benefit of targeting these risk factors has stagnated, and the discovery of new therapeutic targets for atherosclerosis remains a challenge. Accumulating evidence from clinical and animal experiments has revealed that the gut microbiome play a significant role in human health and disease, including cardiovascular diseases. The gut microbiome contribute to host health and disease through microbial composition and function. The gut microbiome function like an endocrine organ by generating bioactive metabolites that can impact atherosclerosis. In this review, we describe two gut microbial metabolites/pathways by which the gut affects atherosclerotic cardiovascular disease. On the one hand, we discuss the effects of trimethylamine oxide (TMAO), bile acids and aromatic amino acid metabolites on the development of atherosclerosis, and the protective effects of beneficial metabolites short chain amino acids and polyamines on atherosclerosis. On the other hand, we discuss novel therapeutic strategies for directly targeting gut microbial metabolites to improve cardiovascular outcomes. Reducing gut-derived TMAO levels and interfering with the bile acid receptor farnesoid X receptor (FXR) are new therapeutic strategies for atherosclerotic disease. Enzymes and receptors in gut microbiota metabolic pathways are potential new drug targets. We need solid insight into these underlying mechanisms to pave the way for therapeutic strategies targeting gut microbial metabolites/pathways for atherosclerotic cardiovascular disease.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Microbioma Gastrointestinal , Animais , Humanos , Doenças Cardiovasculares/etiologia , Metilaminas/metabolismo , Aterosclerose/diagnóstico , Aterosclerose/tratamento farmacológico , Aterosclerose/complicações
4.
Anal Chem ; 94(8): 3727-3734, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35184546

RESUMO

The real-time tracking and efficacy evaluation of therapeutic nanoplatforms especially in deep-tissues is of great importance but faces challenges. Meanwhile, chemodynamic therapy (CDT), relying on Fenton reaction by converting H2O2 into toxic hydroxyl radicals (•OH), has drawn wide interests in the fabrication of nanozymes for tumor therapy, while endogenous H2O2 is usually insufficient for effective CDT. Here, we report the pH-responsive multifunctional nanoplatforms consisting of copper peroxide (CP) nanoparticles, paclitaxel (PTX) and perfluoro-15-crown-5-ether (PFCE), for 19F magnetic resonance imaging guided and enhanced chemo-chemodynamic synergetic therapy with self-supplied H2O2 stemmed from the decomposition of CP nanoparticles under acid conditions in tumor. The decomposition of CP nanoparticles further promotes the release of PTX for enhanced chemotherapy. Both in vitro and in vivo results indicate that the efficient generation of •OH and drug release effectively inhibits tumor growth. Furthermore, 19F MRI signal can clearly track the fate of nanoplatforms in tumor and guide tumor treatment. This work provides a promising strategy for the rational design and construction of multifunctional nanoplatforms for imaging-guided synergistic therapy of deep seated tumor.


Assuntos
Peróxido de Hidrogênio , Nanopartículas , Linhagem Celular Tumoral , Radical Hidroxila , Imageamento por Ressonância Magnética
5.
Anal Chem ; 92(17): 11739-11746, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32786481

RESUMO

Multiresponsive nanoprobes are highly desirable for low background and highly sensitive imaging in biomedical applications. Herein, we design a glutathione (GSH)/pH dual-responsive nanoprobe capable of both fluorescence imaging in cells and 19F magnetic resonance imaging (19F MRI) in deep tissue, by encapsulating manganese oleate (Mn(OA)2) on the surface of fluorinated fluorescent quantum dots (F-ZnS:Mn2+). In this approach, Mn(OA)2 serves as an efficient quencher of both fluorescence and 19F MRI signal. Both the fluorescence and 19F MRI signal can be turned on by introducing glutathione (GSH) that breaks up the Mn-O bonds within Mn(OA)2 under weak acidity conditions (e.g., pH 6.0). The imaging results in cells and mice suggest that this novel strategy can offer a promising nanoprobe for turn-on fluorescence/19F MRI dual-modal tumor imaging.


Assuntos
Imageamento por Ressonância Magnética/métodos , Nanomedicina/métodos , Imagem Óptica/métodos , Fluorescência , Humanos , Pontos Quânticos/química
6.
J Am Chem Soc ; 140(37): 11594-11598, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30168714

RESUMO

Single-atom metal-nitrogen-carbon (M-N-C) catalysts have sparked intense interests, but the catalytic contribution of N-bonding environment neighboring M-N4 sites lacks attention. Herein, a series of Fe-N-C nanoarchitectures have been prepared, which confer adjustable numbers of atomically dispersed Fe-N4 sites, tunable hierarchical micro-mesoporous structures and intensified exposure of interior active sites. The optimization between Fe-N4 single sites and carbon matrix delivers superior oxygen reduction reaction activity (half-wave potential of 0.915 V vs RHE in alkaline medium) with remarkable stability and high atom-utilization efficiency (almost 10-fold enhancement). Both experiments and theoretical calculations verified the selective C-N bond cleavage adjacent to Fe center induced by porosity engineering could form edge-hosted Fe-N4 moieties, and therefore lower the overall oxygen reduction reaction barriers comparing to intact atomic configuration. These findings provide a new pathway for the integrated engineering of geometric and electronic structures of single-atom materials to improve their catalytic performance.

7.
Anal Chem ; 88(2): 1434-9, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26691536

RESUMO

Aqueous sulfides are emerging signaling agents implicated in various pathological and physiological processes. The development of sensitive and selective methods for the sensing of these sulfides is therefore very important. Herein, we report that the as-synthesized 1-oxo-1H-phenalene-2,3-dicarbonitrile (OPD) compound provides promising fluorescent properties and unique reactive properties toward aqueous sulfides. It was found that OPD showed high selectivity and sensitivity toward Na2S over thiols and other inorganic sulfur compounds through a sulfide involved reaction which was confirmed by high-resolution mass spectroscopy (HRMS) and nuclear magnetic resonance (NMR) results. The fluorescence intensity increases linearly with sulfide concentration in the range of 1.0-30 µM with a limit of detection of 52 nM. This novel fluorescent probe was further exploited for the fluorescence imaging sensing of aqueous sulfide in HeLa cells.


Assuntos
Corantes Fluorescentes/química , Nitrilas/química , Espectrometria de Fluorescência/instrumentação , Sulfetos/análise , Sobrevivência Celular , Corantes Fluorescentes/análise , Células HeLa , Humanos , Estrutura Molecular , Nitrilas/análise , Sulfetos/química , Água/química
8.
Anal Chem ; 88(15): 7853-7, 2016 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-27349933

RESUMO

The use of fluorescence probes for biomedical imaging has attracted significant attention over recent years owing to their high resolution at cellular level. The probes are available in many formats including small particle size based imaging agents which are considered to be promising candidates, due to their excellent stabilities. Yet, concerns over the potential cytotoxicity effects of inorganic luminescent particles have led to questions about their suitability for imaging applications. Exploration of alternatives inspired us to use organic fluorophores with aggregation-induced emission (AIE), prepared by functionalizing the amine group on tetraphenylethene with 3,5-bis(trifluoromethyl)phenyl isocyanate. The as-synthesized novel AIE fluorophore (TPE-F) display enhanced quantum yield and longer lifetime as compared with its counterparts (4,4',4″,4‴-(ethene-1,1,2,2-tetrayl)tetraaniline, TPE-AM). Furthermore, the TPE-F was encapsulated into small-size organic nanoparticles (NPs; dynamic light scattering size, ∼10 nm) with polysuccinimide (PSI). The biocompatibility, excellent stability, bright fluorescence, and selective cell targeting of these NPs enable the as-prepared TPE-F NPs to be suitable for specific fluorescence cell imaging.


Assuntos
Corantes Fluorescentes/química , Microscopia Confocal , Nanopartículas/química , Difusão Dinâmica da Luz , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Polímeros/química
9.
Anal Chem ; 87(4): 2383-8, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25605399

RESUMO

We developed an efficient one-pot strategy for the preparation of hydrophilic amine-functionalized nanocomposites by using hydrophobic fluorescence quantum dots ZnS:Mn(2+)@allyl mercaptan (QDs@AM) as building blocks through novel light-induced in situ polymerization. The average size of as-prepared hydrophilic nanocomposites was ∼50 nm, which could be further tuned by varying the concentrations of the monomers. Importantly, these nanocomposites were further utilized for the facile, highly sensitive, and selective detection of nitroaromatics. The linear ranges for 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP) lie in 0.01-0.5 µg/mL and 0.05-8.0 µg/mL, respectively, barely interfered with by other nitroaromatics such as 2,4-dinitrotoluene (DNT) and nitrobenzene (NB). Moreover, the novel surface modification method developed here offered a general strategy for fabricating hydrophobic nanocomposites with hydrophilic properties and indicated various potential applications including sensing and imaging.


Assuntos
Corantes Fluorescentes/química , Nanotecnologia , Nitrobenzenos/análise , Pontos Quânticos , Compostos Alílicos/química , Fluorescência , Corantes Fluorescentes/análise , Interações Hidrofóbicas e Hidrofílicas , Manganês/química , Nitrobenzenos/química , Processos Fotoquímicos , Polimerização , Sulfetos/química , Compostos de Zinco/química
10.
Small ; 11(33): 4183-90, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25981697

RESUMO

According to the simulation, the self-assembly of Cu7 S4 nanocrystals would enhance the photothermal conversion efficiency (PCE) because of the localized surface plasmon resonance effects, which is highly desirable for photothermal therapy (PTT). A new strategy to synthesize Cu7 S4 nanosuperlattices with greatly enhanced PCE up to 65.7% under irradiation of 808 nm near infrared light is reported here. By tuning the surface properties of Cu7 S4 nanocrystals during the synthesis via thermolysis of a new single precursor, dispersed nanoparticles (NPs), rod-like alignments, and nanosuperlattices are obtained, respectively. To explore their PTT applications, these hydrophobic nanostructures are transferred into water by coating with home-made amphiphilic polymer while maintaining their original structures. Under identical conditions, the PCE are 48.62% and 56.32% for dispersed NPs and rod-like alignments, respectively. As expected, when the nanoparticles are self-assembled into nanosuperlattices, the PCE is greatly enhanced up to 65.7%. This strong PCE, along with their excellent photothermal stability and good biocompatibility, renders these nanosuperlattices good candidates as PTT agents. In vitro photothermal ablation performances have undoubtedly proved the excellent PCE of our Cu7 S4 nanosuperlattices. This research offers a versatile and effective solution to get PTT agents with high photothermal efficiency.


Assuntos
Cobre/química , Fototerapia/instrumentação , Pontos Quânticos/química , Compostos de Enxofre/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Doxiciclina/química , Doxiciclina/farmacologia , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Raios Infravermelhos , Nanoestruturas/química , Fototerapia/métodos , Compostos de Enxofre/química , Compostos de Enxofre/farmacologia , Propriedades de Superfície
11.
Adv Healthc Mater ; 12(26): e2300883, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37437241

RESUMO

The fast renal clearance of hydrophilic small molecular anticancer drugs and ultrasmall nanoparticles (NPs) results in the low utilization rate and certain side effects, thus improving the tumor targeting is highly desired but faces great challenges. A novel and general ß-cyclodextrin (CD) aggregation-induced assembly strategy to fabricate doxorubicin (DOX) and CD-coated NPs (such as Au) co-encapsulated pH-responsive nanocomposites (NCs) is proposed. By adding DOX×HCl and reducing pH in a reversed microemulsion system, hydrophilic CD-coated AuNPs rapidly assemble into large NCs. Then in situ polymerization of dopamine and sequentially coordinating with Cu2+ on the surface of NCs provide extra weak acid responsiveness, chemodynamic therapy (CDT), and improved biocompatibility as well as stability. The subsequent tumor microenvironment responsive dissociation notably improves their passive tumor targeting, bioavailability, imaging, and therapeutic capabilities, as well as facilitates their internalization by tumor cells and metabolic clearance, thereby reducing side effects. The combination of polymerized dopamine and assembled AuNPs reinforces photothermal capability, thus further boosting CDT through thermally amplifying Cu-catalyzed Fenton-like reaction. Both in vitro and in vivo studies confirm the desirable outcomes of these NCs as photoacoustic imaging guided trimodal (thermally enhanced CDT, photothermal therapy, and chemotherapy) synergistic tumor treatment agents with minimal systemic toxicity.


Assuntos
Hipertermia Induzida , Nanopartículas Metálicas , Nanopartículas , Neoplasias , Humanos , Ouro , Dopamina/uso terapêutico , Hipertermia Induzida/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Nanopartículas/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Linhagem Celular Tumoral , Microambiente Tumoral
12.
Signal Transduct Target Ther ; 8(1): 55, 2023 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737432

RESUMO

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.


Assuntos
Aneurisma da Aorta Abdominal , Ruptura Aórtica , Animais , Humanos , Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/genética , Ruptura Aórtica/terapia , Estudos de Coortes
13.
Adv Sci (Weinh) ; 10(26): e2302123, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37449329

RESUMO

Cardiovascular disease is the leading cause of death worldwide. Reperfusion therapy is vital to patient survival after a heart attack but can cause myocardial ischemia/reperfusion injury (MI/RI). Nitric oxide (NO) can ameliorate MI/RI and is a key molecule for drug development. However, reactive oxygen species (ROS) can easily oxidize NO to peroxynitrite, which causes secondary cardiomyocyte damage. Herein, L-arginine-loaded selenium-coated gold nanocages (AAS) are designed, synthesized, and modified with PCM (WLSEAGPVVTVRALRGTGSW) to obtain AASP, which targets cardiomyocytes, exhibits increased cellular uptake, and improves photoacoustic imaging in vitro and in vivo. AASP significantly inhibits oxygen glucose deprivation/reoxygenation (OGD/R)-induced H9C2 cell cytotoxicity and apoptosis. Mechanistic investigation revealed that AASP improves mitochondrial membrane potential (MMP), restores ATP synthase activity, blocks ROS generation, and prevents NO oxidation, and NO blocks ROS release by regulating the closing of the mitochondrial permeability transition pore (mPTP). AASP administration in vivo improves myocardial function, inhibits myocardial apoptosis and fibrosis, and ultimately attenuates MI/RI in rats by maintaining mitochondrial function and regulating NO signaling. AASP shows good safety and biocompatibility in vivo. This findings confirm the rational design of AASP, which can provide effective treatment for MI/RI.


Assuntos
Traumatismo por Reperfusão Miocárdica , Ratos , Animais , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/uso terapêutico , Ouro , Arginina/metabolismo , Mitocôndrias/metabolismo
14.
Neuron ; 111(22): 3634-3649.e7, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37683629

RESUMO

Blood-brain barrier (BBB) function deteriorates during aging, contributing to cognitive impairment and neurodegeneration. It is unclear what drives BBB leakage in aging and how it can be prevented. Using single-nucleus transcriptomics, we identified decreased connexin 43 (CX43) expression in cadherin-5+ (Cdh5+) cerebral vascular cells in naturally aging mice and confirmed it in human brain samples. Global or Cdh5+ cell-specific CX43 deletion in mice exacerbated BBB dysfunction during aging. The CX43-dependent effect was not due to its canonical gap junction function but was associated with reduced NAD+ levels and mitochondrial dysfunction through NAD+-dependent sirtuin 3 (SIRT3). CX43 interacts with and negatively regulates poly(ADP-ribose) polymerase 1 (PARP1). Pharmacologic inhibition of PARP1 by olaparib or nicotinamide mononucleotide (NMN) supplementation rescued NAD+ levels and alleviated aging-associated BBB leakage. These findings establish the endothelial CX43-PARP1-NAD+ pathway's role in vascular aging and identify a potential therapeutic strategy to combat aging-associated BBB leakage with neuroprotective implications.


Assuntos
Conexina 43 , NAD , Animais , Humanos , Camundongos , Envelhecimento/fisiologia , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Conexina 43/genética , Conexina 43/metabolismo , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo
15.
ACS Appl Mater Interfaces ; 13(17): 20094-20104, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33890773

RESUMO

The design of low-cost yet highly efficient electrocatalysts plays a critical role in energy storage and conversion reactions. The oxygen evolution reaction (OER) is considered a bottleneck of electrochemical water splitting for hydrogen fuel generation. It is still challenging to extract a high density of charge carriers in noble-metal-free alternative catalysts to facilitate sluggish kinetics. Herein, we report the rational design and coherent interface engineering for combining light-harvesting Cu31S16 with electroactive Co9-xNixS8 (x = 0-9) to form novel Cu31S16-Co9-xNixS8 heterodimers. By delicately controlling the kinetic growth in a seed-mediated growth method, the bifunctional centers, even with two distinct crystal phases, were integrated into a synergistic architecture, which achieved full-spectrum solar energy capture and light conversion to drive and activate the electrochemical reaction. Benefiting from the well-defined structure, high-quality interface, oriented attachment, and optimal Co/Ni bimetal ratio, Cu31S16-Co7.2Ni1.8S8 produces a dramatically reduced overpotential (242 mV at 10 mA cm-2) with a shift of 83 mV under visible-light excitation, achieving a 4.5-fold higher turnover frequency than that of its unirradiated Co7.2Ni1.8S8 counterpart. This enhanced performance also far exceeds commercial RuO2 (358 mV at 10 mA cm-2) and most nonprecious-metal nanocatalysts. Further mechanistic studies reveal that coherent interface engineering leads to a strong photo/electricity coupling effect and efficient spatial charge separation, which induces sufficient hot holes that eventually accumulate at the electroactive sites to accelerate the multihole-involved OER. This work would open up new opportunities for the fabrication of non-noble metal electrocatalysts and management of charge carriers.

16.
ACS Omega ; 5(14): 8373-8379, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32309748

RESUMO

Hydrogen sulfide (H2S) is considered as a highly toxic environmental pollutant and an important signal transmitter in physiological processes, and the selective and reliable detection of H2S is of great concern and remains challenging. Herein, we report a smart sensitive "off-on" 19F NMR sensor for H2S by partially introducing a fluorinated ligand to construct a hollow dual metal-organic framework (MOF) nanosystem, F-ZnFeIII hMOF, in which the fluorinated ligand acts as the 19F signal source but is initially quenched due to the strong paramagnetic relaxation enhancement (PRE) effect from neighboring Fe3+ nodes. Upon exposure to sulfide ions, reduction of Fe3+ to Fe2+ is specifically triggered, which attenuates PRE efficiency, thus turning on the 19F NMR signal. The unique hollow MOF architecture benefits the mobility of 19F atoms, thereby improving the response sensitivity. Meanwhile, the desirable H2S-sorption feature and appropriate redox potential of Fe3+/Fe2+ account for the favorable selectivity. The increase in the 19F signal is linear with the concentration of sulfide in the range of 20 to 150 µM with a detection limit of 2.8 µM. The probe is well demonstrated by analyzing H2S in complex matrixes such as biological and foodstuff samples.

17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(1): 98-102, 2008 Jan.
Artigo em Zh | MEDLINE | ID: mdl-18422128

RESUMO

An efficient and environmentally friendly procedure for the one-pot synthesis of (3S,4aS,8aS)-2-((2R,3R)-3-amino-2-hydroxy-4-(phenylthio)butyl)- N-tert -butyl-decahydroisoquinoline-3-carboxamide(VII), the intermediate of nelfinavir, was described, and activating ester was applied to getting nelfinavir(IX). Under the catalysis of potassium hydroxide, benzyl (R)-1-((S)-oxiran-yl)-2-(phenylthio) ethyl carbamate was obtained(IV) in methanol. Then IV and (3S,4aS,8aS)- N-tert -butyl-decahydroisoquinoline-3-carboxamide(V) were refluxed in methanol until the reaction was finished. Potassium hydroxide(w(KOH) = 40%) in water was added to remove benzyloxycarbonyl group in water bath with a yield of 89.0%. 3-acetoxy-2-methylbenzoic acid-succinimide ester(II) reacted with VII and acetyl group was removed by dense aqueous ammonia, giving nelfinavir(IX). The vibrations of functional groups of thiIIs compound corresponding to the main infrared absorption peaks were discussed. The molecular ion and quasi molecular ion peaks were obtained via MALDI-TOF MS, and 1H NMR and 13CNMR shifts of this compound were assigned by means of DEPT(distortionless enhancement by polarization transfer spectrum), HMBC(1H detected heteronuclearmultiple bond correlation spectrum), HSQC(1H detected heteronuclear single-quantum coherence spectrum) and DQF-COSY(double-quantum filtered-correlated spectroscopy). The results provided useful information for structure characterization and quality control of nelfinavir.


Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/síntese química , Nelfinavir/química , Nelfinavir/síntese química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Espectrofotometria Infravermelho
18.
J Mater Chem B ; 6(47): 7936-7942, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-32255039

RESUMO

Metal-organic frameworks (MOFs) have been widely used for drug/dye loading, but the large scale continuous production of these nanoparticles with good stability and biocompatibility still faces great challenges. Herein, a thermal-assisted microfluidic system was developed for the continuous and scalable fabrication of drug loaded MOFs@SiO2 nanoparticles with uniform shape, narrow size distribution, good stability and excellent biocompatibility. This facile and general strategy is readily employed in the encapsulation of many dyes and drugs. In vivo photodynamic therapy for cancers, based on rose bengal-loaded nanoparticles, demonstrates the great potential of this novel fabrication strategy in biomedical fields.

19.
Food Chem ; 269: 342-346, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30100444

RESUMO

Furan, which has been identified as a carcinogenic risk for humans, can be induced in different foods by UV-C light. In this study, we hypothesized that furan was produced by a UV light-induced free radical mechanism and antioxidants could suppress its formation. Our results demonstrated that, by adding antioxidants, such as butylated hydroxyl toluene, ascorbic acid or gallic acid, to simulated juice or apple cider during UV-C treatment, amounts of furan were significantly reduced. For example, the concentration of furan produced in apple cider by UV-C at 9.0 J/cm2 was 636 ppb but was less than 20 ppb with 0.25 ppm butylated hydroxyl toluene present, less than 3 ppb with 0.5% (w/v) ascorbic acid, and less than 1.0 ppb with 0.5% (w/v) gallic acid. These findings confirmed that antioxidants can be used as a safe and simple mitigation measure to control furan production in fruit drinks exposed to UV-light.


Assuntos
Manipulação de Alimentos/métodos , Furanos/síntese química , Malus/química , Raios Ultravioleta , Antioxidantes , Ácido Ascórbico , Bebidas/análise , Humanos , Açúcares
20.
Food Chem ; 192: 9-14, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304314

RESUMO

A headspace solid phase microextraction (HS-SPME) procedure followed by gas chromatography-flame ionisation detector (GC-FID) analysis was developed and validated for the simultaneous analysis of furan, 2-methylfuran and 2-pentylfuran from juice samples. Extraction at 32 °C for 20 min with stirring at 600 rpm and NaCl concentration 15% (W/V) was the optimal HS-SPME condition for all the three compounds by using a carboxen/polydimethylsiloxane fused silica fibre (75 µm). The extracted compounds were base line separated on a SPB-1 GC column within 12 min. The relative standard deviations of all analytes were less than 6.7%. The recovery rates were between 90.2% and 110.1%. The limits of detection and limits of quantification were 0.056-0.23 ng/mL and 0.14-0.76 ng/mL, respectively. The results showed that the developed method was sensitive, precise, accurate and robust for the determination of furan, 2-methylfuran and 2-pentylfuran in complex matrices without interferences from other components.


Assuntos
Ionização de Chama/métodos , Sucos de Frutas e Vegetais/análise , Furanos/química , Microextração em Fase Sólida/métodos , Cromatografia Gasosa/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos
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