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4-Amino-1,8-naphthalimide based fluorescent photoinduced electron transfer (PET) pH sensors as liposomal cellular imaging agents: The effect of substituent patterns on PET directional quenching

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Frontiers of Chemical Science and Engineering 2020年第1期14卷 61-75页

作者： Miguel Martinez-Calvo Sandra A.Bright Emma B.Veale Adam F.Henwood D.Clive Williams Thorfinnur Gunnlaugsson School of Chemistry and Trinity Biomedical Sciences Institute(TBSI) Trinity College DublinThe University of DublinDublin 2Ireland School of Biochemistry and Immunology and Trinity Biomedical Sciences Institute(TBSI) Trinity College DublinThe University of DublinDublin 2Ireland Centro Singular de Investigacion en quimica Bioloxica e Materiais Moleculares(CIQUS)and departamento de quimica Organica Universidade de Santiago de Compostela Rua Jenaro de la Fuente s/n15782Santiago de CompostelaSpain

Four new fluorescent sensors(1-4)based on the 4-amino-1,8-naphthalimide fluorophores(Naps)have been synthesized based on the classical fluorophore-spacer-receptor model.These four compounds all gave rise to emission bands centred at ca.535 nm,which were found to be highly pH dependent,the emission being‘switched on’in acidic media,while being quenched due to PET from the amino moieties to the excited state of the Nap at more alkaline pH.The luminescent pH dependence for these probes was found to be highly dependent on the substitution on the imide site,as well as the polyamine chain attached to the position 4-amino moiety.In the case of sensor 2 the presence of the 4-amino-aniline dominated the pH dependent quenching.Nevertheless,at higher pH,PET quenching was also found to occur from the polyamine site.Hence,2 is better described as a receptor1-spacer1-fluorophore-spacer2-receptor2 system,where the dominant PET process is due to(normally less favourable)‘directional’PET quenching from the 4-amino-aniline unit to the Nap site.Similar trends and pH fluorescence dependences were also seen for 3 and 4.These compounds were also tested for their imaging potential and toxicity against HeLa cells(using DRAQ5 as nuclear stain which does now show pH dependent changes in acidic and neutral pH)and the results demonstrated that these compounds have reduced cellular viability at moderately high concentrations(with IC50 values between ca.8-30μmol?L^?1),but were found to be suitable for intracellular pH determination at 1μmol?L^?1 concentrations,where no real toxicity was observed.This allowed us to employ these as lysosomal probes at sub-toxic concentrations,where the Nap based emission was found to be pH depended,mirroring that seen in aqueous solution for 1-4,with the main fluorescence changes occurring within acidic to neutral pH.

关键词： sensors pH photoinduced electron transfer cellular imaging confocal microscopy

Cadmium sorption by sodium and thiourea-modified zeolite-rich tuffs

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Journal of Environmental Sciences 2017年第2期29卷 39-48页

作者： Perfecto Barragán P M.Guadalupe Macedo M Maria T.Olguín Instituto Tecnologico de Toluca Laboratorio de Investigacion en Ingenieria Ambiental.Av.Tecnologico S/NColonia Ex-Rancho La VirgenMetepecEstado de Meico CP.52140Mexico Instituto National de Investigaciones Nucleares Departamento de QuimicaA.P.18-1027Col.EseandonDelegacion Miguel Hidalgo C.P.11801Mexico

In the present investigation, two zeolite-rich tuffs from Guaymas and El Cajon（State of Sonora）, which were conditioned with a sodium chloride solution and subsequently modified with a thiourea solution, were chosen to evaluate the removal of Cd from aqueous systems. The zeolitic materials were characterized by scanning electron microscopy and X-ray diffraction. The surface area was also determined. The experiments were performed in a batch system, and the influences of p H, contact time between phases, and the concentration of Cd in the solution on the adsorption by sodium or thiourea-modified zeolite-rich tuff were investigated. It was found that the efficiency of Cd ion removal from aqueous solutions is influenced by the p H of the aqueous systems. The Cd adsorption kinetic data were well fitted to a pseudo-second-order model in all cases. The Langmuir and Langmuir–Freundlich isotherms adequately described the Cd sorption behavior by the zeolite from El Cajon pretreated with Na Cl and the zeolite from Guaymas modified with thiourea, respectively.

关键词： Cadmium Zeolite-rich-tuff Sorption Kinetics Isotherms

Nickel phosphonate MOF as efficient water splitting photocatalyst

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Nano Research 2021年第2期14卷 450-457页

作者： Pablo Salcedo-Abraira Sergio M.F.Vilela Artem A.Babaryk Maria Cabrero-Antonino Pedro Gregorio Fabrice Salles Sergio Navalon Hermenegildo Garcia Patricia Horcajada IMdeA Energy Advanced Porous Materials Unit(APMU)Avda.Ramon de Ia Sagra 3E 28935 MostolesMadridSpain deparrtamento de quimica Inorginica I.Fac.CC.quimicas Universidad Complutense de MadridAvda.Complutense s/n28040 MadridSpain departamento de quimica and Instituto de Tecnologia quimica(CSIC-UPV) Universitat Politecnica de ValenciaC/Camino de Veras/n46022 ValenciaSpain Institut Charles Gerhardt Montpellier UMR 5253 CNRS UM ENSCMUniversite MontpellierPlace E.Bataillon34095 Montpellier Cedex 05France

A novel microporous two-dimensional(2D)Ni-based phosphonate metal-organic framework(MOF;denoted as IEF-13)has been successfully synthesized by a simple and green hydrothermal method and fully characterized using a combination of experimental and computational techniques.Structure resolution by single-crystal X-ray diffraction reveals that IEF-13 crystallizes in the triclinic space group Pi having bi-octahedra nickel nodes and a photo/electroactive tritopic phosphonate ligand.Remarkably,this material exhibits coordinatively unsaturated nickel(II)sites,free-P0_(3)H_(2)and-P0_(3)H acidic groups,a C0_(2)accessible microporosity,and an exceptional thermal and chemical stability.Further,its in-deep optoelectronic characterization evidences a photoresponse suitable for photocatalysis.In this sense,the photocatalytic activity for challenging H_(2)generation and overall water splitting in absence of any co-catalyst using UV-Vis irradiation and simulated sunlight has been evaluated,constituting the first report for a phosphonate-MOF photocatalyst.IEF-13 is able to produce up to 2,200 fimol of H_(2)per gram using methanol as sacrificial agent,exhibiting stability,maintaining its crystal structure and allowing its recycling.Even more,170μmol of H_(2)per gram were produced using IEF-13 as photocatalyst in the absence of any co-catalyst for the overall water splitting,being this reaction limited by the 0_(2)reduction.The present work opens new avenues for further optimization of the photocatalytic activity in this type of multifunctional materials.

关键词： metal-organic framework phosphonates photocatalysis water splitting

An egg-shell bifunctional CeO_(2)-modified NiPd/Al_(2) O_(3) catalyst for petrochemical processes involving selective hydrogenation and hydroisomerization

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Journal of Rare Earths 2021年第11期39卷 1382-1388,I0003页

作者： Franklin J.Mendez Javier A.Alves Yahse Rojas-Challa Oscar Corona Yanet Villasana Julia Guerra German Garcia-Colli Osvaldo M.Martinez Joaquin L.Brito Centro de quimica Instituto Venezolano de Invesdgaciones CientfficasCarretera PanamericanaKm 11 Altos de PipeCaracas1020AVenezuela departamento de Estado Solido Instituto de FisicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico departamento de Ingenieria quimica Facultad de Ingenieria(UNLP)and Centro de Investigacion y Desarrollo en Ciencias Aplicadas"Dr.J.J.Ronco"(CINDECA)CCT-La Plata-CONICET-UNLPLa Plata1900Argentina departamento de quimica Analitica Facultad de QufmicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico04510Mexico Instituto Tecnoldgico Venezolano del Petroleo SA. Petrole os de Venezuela SA.Urb.Santa Rosa-Sector El TamborLos Teques1201Venezuela Instituto Superior de Formacion Docente Salome Urena Esquina Leonardo D'VinciSanto Domingo10114Republica Dominicana Biomass to Resources Group Universidad Regional Amazonica IkiamKm 7 via MuyunaTena150150Ecuador departamento de Termodinamica y Fenomenos de Transferencia Universidad Simon BolivarValle de SartenejasCaracas1086Venezuela

The catalytic performance during the 1-butyne hydrogenation using two reduced Al_(2) O_(3)-supported Pdbased catalysts was carried out in a total recirculation system with an external fixed-bed reactor.The lab-prepared egg-shell NiPd/CeO_(2)-Al_(2) O_(3) catalyst(NiPdCe) with Pd loading=0.5 wt%,Ni/Pd atomic ratio=1 and CeO_(2) loading=3 wt% was synthesized and characterized,and it was compared with an egg-shell Al_(2) O_(3)-supported Pd based commercial catalyst(PdCC).The reduced catalysts were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy.The textural characteristics and ammonia temperature-programmed desorption profiles of the fresh(unreduced) catalysts were also obtained.Both catalysts show high 1-butyne conversion and selectivity to 1-butene,but the catalysts also present important differences between hydroisomerizing and hydrogenating capabilities.NiPdCe catalyst shows higher capability for hydroisomerization reactions,while the PdCC catalyst exhibits higher hydrogenating capability.The observed catalytic performances can be interesting for some industrial processes and can provide a guideline for the development of a Pd-based catalyst with specific catalytic properties.

关键词： 1-Butyne Bifunctional catalyst Egg-shell Hydrogenation Hydroisomerization NiPd catalyst

Carbonaceous residues from biomass gasification as catalysts for biodiesel production

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Journal of Natural Gas Chemistry 2012年第3期21卷 246-250页

作者： Rafael Luque Antonio Pineda Juan C. Colmenares Juan M. Campelo Antonio A. Romero Juan Carlos Serrano-Ruiz Luisa F. Cabeza Jaime Cot-Gores departamento de quimica Organica Universidad de Cardoba Campus de Rabanales Edif icio Marie Curie E-14014 Cardoba Spain Universitat de Lleida GREA lnnovacio Concurrent Lleida Spain Universitat de Lleida GREA lnnovacio Concurrent Lleida Spain

Tars and alkali ashes from biomass gasification processes currently constitute one of the major problems in biomass valorisation, generating clogging of filters and issues related with the purity of syngas production. To date, these waste residues find no useful applications and they are generally disposed upon generation in the gasification process. A detailed analysis of these residues pointed out the presence of high quantities of Ca （〉30 wt%）. TG experiments indicated that a treatment under air at moderate temperatures （400-800 ~C） decomposed the majority of carbon species, while XRD indicated the presence of a crystalline CaO phase. CaO enriched valorized materials turned out to be good heterogeneous catalysts for biodiesel production from vegetable oils, providing moderate to good activities （50%-70% after 12 h） to fatty acid methyl esters in the transesterification of sunflower oil with methanol.

关键词： biomass gasification residues biodiesel catalyst calcium oxide

Fast determination of Benzodiazepines in Human Urine via Liquid-Liquid Extraction with Low Temperature Partitioning and LC-HRMS

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American Journal of Analytical Chemistry 2012年第2期3卷 118-124页

作者： Elisangela Jaqueline Magalhaes Clesia Cristina Nascentes Rodinei Augusti Maria Eliana Lopes Ribeiro de Queiroz Julio Cesar Cardoso da Silva Robson Jose de Cassia Franco Afonso departamento de quimica Universidade Federal de Minas GeraisBelo HorizonteBrazil departamento de quimica Universidade Federal de VicosaVicosaBrazil departamento de quimica Universidade Federal de Ouro PretoOuro PretoBrazil

A simple and high-throughput method to simultaneously determine selected benzodiazepines (i.e., diazepam, lorazepam, clonazepam, and bromazepam) in urine was developed and validated. The entire methodology consisted of the application of an innovative extraction/cleanup procedure, namely liquid-liquid extraction with low-temperature partitioning (LLE-LTP), and analysis by liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). The LLE-LTP procedure was optimized via factorial design and by evaluating crucial variables, specifically the freezing mode (either slow or fast), the urine/acetonitrile volume ratio, and the sample ionic strength. The benzodiazepines were quantified using matrix-matched calibration curves where the following parameters were assessed by validation protocol: in general, linearity range of 17 - 200 μg?L–1 (r > 0.9957);limits of detection lower than 5 μg?L–1;relative standard deviations (RSD) lower than 12.5%;and accuracy ranging from 72.3 to 117%. To test this procedure’s performance, the method was applied to determine the content of diazepam in actual urine samples. The validation results obtained for the method demonstrated that the present methodology could be potentially applied in proficient laboratories as a routine approach for determining benzodiazepines compounds content in urine.

关键词： Benzodiazepines Urine LC-HRMS Extraction Procedure Low-Temperature Partitioning

Direct evidence of traps controlling the carriers transport in SnO_(2) nanobelts

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Journal of Semiconductors 2017年第12期38卷 8-12页

作者： Olivia M.Berengue Adenilson J.Chiquito LCCTnano Departamento de Fisica e Quimica-Universidade Estadual Paulista(Unesp)Faculdade de Engenharia de GuaratinguetfiCampus GuaratinguetfiSgo PauloBrasil NanO LaB-departamento de Fisica Universidade Federal de Sao CarlosCEP 13565-905CP 676Sgo CarlosSgo PauloBrasil

This work reports on direct evidence of localized states in undoped Sn02 nanobelts. Effects of disorder and electron localization were observed in Schottky barrier dependence on the temperature and in thermally stimulated currents. A transition from thermal activation to hopping transport mechanisms was also observed. The energy levels found by thermally stimulated current experiments were in close agreement with transport data confirming the role of localization in determining the properties of devices.

关键词： trap transport SnO2

Phenolic profile and biological potential of Endopleura uchi extracts

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Asian Pacific Journal of Tropical Medicine 2015年第11期8卷 870-878页

作者： Luis R.Silva Rafaela Teixeira CICS-UBI-Centro de Investigacao em Ciencias da Saude.Universidale da Beira Interior Av.Infante D.Henrique.6201-506.Corilha.Portugal Instituto Politecnico de Castelo Branco Escola Superior de Saude Dr Lopes DiasArenido do EmpresarioCampus da Talagueira6000-767Castelo BrancaPortugal LEPABE Departamento de Engenharia QuimicaFaculdade de Engenharia.Universidade do PortoRua Dr.Roberto Friass/n4200-465 PortoPortugal REQUIMTE/Laboratorio de Farmacognosia Departamento de QuimicaFaculdade de FarmaciaUniversidade do Porto.Rua de Jorge Viterbo Ferreira228.4050-313 PortoPortugal

Objective:To improve the knowledge on the metabolite composition of Endopleura uchi bark,concerning phenolic compounds,and to evaluate some of its biological capacities for further possible exploitation in food and pharmaceutical industries associated to their healthpromoting qualities.Methods:Two different extracts(infusion and hydroethanolic) were studied concerning phenolic composition and biological potential.Results:Five compounds were determined by HPLC-DAD,being bergenin the major one.In general way,infusion presents a greater richness in these metabolites.The antioxidant,acetylcholinesterase.butyrylcholinesterase,α-glucosidase and antibacterial activity were checked by in vitro assays.A dose-dependent response was noticed against DPPH,superoxide and nitric oxide radicals,acetylcholinesterase,butyrylcholinesterase and against α-glucosidase inhibitory assay.Antibacterial capacity of both extracts was investigated against Gram-positive and Gramnegative bacteria,being more effective against the first one.The concentrations of infusion extract tested here revealed that is non-toxic for intestinal(Caco-2) cells line.Conclusions:The results suggest that the extracts of Endopleura uchi may be interesting for incorporating in pharmaceutical preparations for human health,since it can suppress hyperglycaemia and inhibit cholinesteases,and or as food additive due to its antiradical and antibacterial activities.

关键词： Endopleura uchi Bark Phenolic compounds Anti-diabe

Evaluation of physicochemical properties as supporting information on quality control of raw materials and veterinary pharmaceutical formulations

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Journal of Pharmaceutical Analysis 2018年第3期8卷 168-175页

作者： Sara da Silva Anacleto Marcella Matos Cordeiro Borges Hanna Leijoto de Oliveira Andressa Reis Vicente Eduardo Costa de Figueiredo Marcone Augusto Leal de Oliveira Barbara Juliana Pinheiro Borges Marcelo Antonio de Oliveira Warley de Souza Borges Keyller Bastos Borges departamento de Ciencias Naturals Universidade Federal de Sao Joao del-Rei Campus Dom Bosco Praca Dora Helvecio 74 Fabricas 36301-160 Sao Joao del-Rei Minas Gerais Brazil departamento de quimica Universidade Federal do Espirito Santo Avenida Fernando Ferrari 514 Goiabeiras 29075-910 Vitdria Espirito Santo Brazil Laboratorio de Analise de Toxicantes e Farmacos Faculdade de Ciencias Farmaceuticas Universidade Federal de Alfenas Rua Gabriel Monteiro da Silva 700 Centro 37130-000 Alfenas Minas Gerais Brazil departamento de quimica Universidade Federal de Juiz de Fora Rua Jose Lourenco Kelmer s/n 36036-330 Juiz de Fora Minas Gerais Brazil Centro de Ciencias da Saude Universidade Federal do Espirito Santo Avenida Marechal Campos 1468 Maruipe 29.043-900 Vitori Espirito Santo Brazil Centro Universitario Norte do Espirito Santo Universidade Federal do Espirito Santo Br 101 Norte Km 67 Sao Mateus Espirito Santo Brazil

This study aimed to show that the physicochemical proprieties obtained by Fourier transform infrared spectroscopy （FTIR）, thermogravimetry （TG）, and scanning electronic microscopy （SEM） can be useful tools for evaluating the quality of active pharmaceutical ingredients （APIs） and pharmaceutical products. In addition, a simple, sensitive, and efficient method employing HPLC-DAD was developed for simulta- neous determination of lidocaine （LID）, ciprofloxacin （CFX） and enrofloxacin （EFX） in raw materials and in veterinary pharmaceutical formulations. Compounds were separated using a Gemini Cm （250 mm×4.6 mm, 5μm） Phenomenex column, at a temperature of 25℃, with a mobile phase containing 10 mM of phosphoric acid （pH 3.29）： acetonitrile （85.7：14.3, v/v） and a flow rate of 1.5 mL/min. Physicochemical characterization by TG, FTIR, and SEM of raw materials of LID, CFX, and EFX provided information useful for the evaluation, differentiation, and qualification of raw materials. Finally, the HPLC method was proved to be useful for evaluation of raw material and finished products, besides satisfying the need for an analytical method that allows simultaneous determination of EFX, CFX, and LID, which can also be extended to other matrices and applications.

关键词： HPLC Physicochemical characterization Quality control Veterinary pharmaceutical formulation Raw material