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1.
Chembiochem ; 21(7): 886-910, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31803982

RESUMO

The combination of supramolecular functional systems with biomolecular chemistry has been a fruitful exercise for decades, leading to a greater understanding of biomolecules and to a great variety of applications, for example, in drug delivery and sensing. Within these developments, the phospholipid bilayer membrane, surrounding live cells, with all its functions has also intrigued supramolecular chemists. Herein, recent efforts from the supramolecular chemistry community to mimic natural functions of lipid membranes, such as sensing, molecular recognition, membrane fusion, signal transduction, and gated transport, are reviewed.

2.
J Am Chem Soc ; 141(51): 20137-20145, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31739668

RESUMO

The membrane transport mechanisms of cell-penetrating peptides (CPPs) are still controversial, and reliable assays to report on their internalization in model membranes are required. Herein, we introduce a label-free, fluorescence-based method to monitor membrane transport of peptides in real time. For this purpose, a macrocyclic host and a fluorescent dye forming a host-dye reporter pair are encapsulated inside phospholipid vesicles. Internalization of peptides, which can bind to the supramolecular host, leads to displacement of the dye from the host, resulting in a fluorescence change that signals the peptide uptake and, thus, provides unambiguous evidence for their transport through the membrane. The method was successfully validated with various established CPPs, including the elusive peptide TP2, in the presence of counterion activators of CPPs, and with a calixarene-based supramolecular membrane transport system. In addition, transport experiments with encapsulated host-dye reporter pairs are not limited to large unilamellar vesicles (LUVs) but can also be used with giant unilamellar vesicles (GUVs) and fluorescence microscopy imaging.

3.
Angew Chem Int Ed Engl ; 56(49): 15742-15745, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29024239

RESUMO

Phosphorylation and dephosphorylation of peptides by kinases and phosphatases is essential for signal transduction in biological systems, and many diseases involve abnormal activities of these enzymes. Herein, we introduce amphiphilic calixarenes as key components for supramolecular, phosphorylation-responsive membrane transport systems. Dye-efflux experiments with liposomes demonstrated that calixarenes are highly active counterion activators for established cell-penetrating peptides, with EC50 values in the low nanomolar range. We have now found that they can even activate membrane transport of short peptide substrates for kinases involved in signal transduction, whereas the respective phosphorylated products are much less efficiently transported. This allows regulation of membrane transport activity by protein kinase A (PKA) and protein kinase C (PKC), as well as monitoring of their activity in a label-free kinase assay.


Assuntos
Peptídeos/metabolismo , Transporte Biológico , Calixarenos/química , Calixarenos/metabolismo , Peptídeos/química , Fosforilação , Tensoativos/química , Tensoativos/metabolismo
4.
Chemistry ; 21(44): 15486-90, 2015 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-26493875

RESUMO

A BODIPY-containing Cu(II) -bipyridine complex for the simple selective fluorogenic detection of NO in air and in live cells is reported. The detection mechanism is based on NO-promoted Cu(II) to Cu(I) reduction, followed by demetallation of the complex, which results in the clearly enhanced emission of the boron dipyrromethene (BODIPY) unit.

5.
Chem Asian J ; 10(10): 2121-5, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26282179

RESUMO

A new photosensitizer (1) based on the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) scaffold has been synthesized. 1 is water soluble and showed an intense absorption band at 490 nm (ɛ=77,600 cm(-1) m(-1)) and an emission at 514 nm. In vitro toxicity of 1 in the presence of light and in darkness has been studied with HeLa, HaCaT, MCF-7, and SCC-13 cell lines. Moreover, internalization studies of 1 in these cell lines were also performed. These results suggested that 1 is more toxic for SCC-13 and HeLa carcinoma cells than for the HaCaT non-cancerous immortal human keratinocytes. Toxicity upon light irradiation was due to the formation of singlet oxygen and reactive oxygen species (ROS). Cellular co-localization experiments revealed preferential localization of the dye in the endoplasmic reticulum.


Assuntos
Compostos de Boro/química , Fármacos Fotossensibilizantes/química , Linhagem Celular Tumoral , Humanos , Luz , Estrutura Molecular , Fotoquimioterapia , Espécies Reativas de Oxigênio , Oxigênio Singlete
6.
J Hazard Mater ; 298: 73-82, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26005922

RESUMO

We report herein a study of the hydrolysis of Tabun mimic DCNP in the presence of different amines, aminoalcohols and glycols as potential suitable organocatalysts for DCNP degradation. Experiments were performed in CD3CN in the presence of 5% D2O, which is a suitable solvent mixture to follow the DCNP hydrolysis. These studies allowed the definition of different DCNP depletion paths, resulting in the formation of diethylphosphoric acid, tetraethylpyrophosphate and phosphoramide species as final products. Without organocatalysts, DCNP hydrolysis occurred mainly via an autocatalysis path. Addition of tertiary amines in sub-stoichiometric amounts largely enhanced DCNP depletion whereas non-tertiary polyamines reacted even faster. Glycols induced very slight increment in the DCNP hydrolysis, whereas DCNP hydrolysis increased sharply in the presence of certain aminoalcohols especially, 2-(2-aminoethylamino)ethanol. For the latter compound, DCNP depletion occurred ca. 80-fold faster than in the absence of organocatalysts. The kinetic studies revealed that DCNP hydrolysis in the presence of 2-(2-aminoethylamino)ethanol occurred via a catalytic process, in which the aminoalcohol was involved. DCNP hydrolysis generally depended strongly on the structure of the amine, and it was found that the presence of the OHCH2CH2N moiety in the organocatalyst structure seems important to induce a fast degradation of DCNP.


Assuntos
Aminas/química , Substâncias para a Guerra Química/toxicidade , Recuperação e Remediação Ambiental/métodos , Agentes Neurotóxicos/toxicidade , Nitrofenóis/toxicidade , Organofosfatos/toxicidade , Amino Álcoois/química , Catálise , Substâncias para a Guerra Química/química , Glicóis/química , Hidrólise , Cinética , Agentes Neurotóxicos/química , Nitrofenóis/química , Organofosfatos/química
7.
Org Biomol Chem ; 12(43): 8745-51, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25260024

RESUMO

A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with DFP in acetonitrile released fluoride that hydrolysed the TIPS group in P4 to yield a colour change from pink to blue. Probe P4 was able to discriminate between DFP and DCNP with remarkable sensitivity; limits of detection of 0.36 and 0.40 ppm for DCNP and DFP, respectively, were calculated. Besides, no interference from other organophosphorous derivatives or with presence of acid was observed. The sensing behaviour of P4 was also retained when incorporated into silica gel plates or onto polyethylene oxide membranes, which allowed the development of simple test strips for the colorimetric detection of DCNP and DFP in the vapour phase. P4 is the first probe capable of colorimetrically differentiating between a Tabun mimic (DCNP) and a Sarin and Soman mimic (DFP).


Assuntos
Compostos de Boro/química , Substâncias para a Guerra Química/análise , Sondas Moleculares/química , Organofosfatos/análise , Sarina/análise , Soman/análise , Acetonitrilos , Compostos de Boro/síntese química , Cor , Colorimetria , Humanos , Limite de Detecção , Membranas Artificiais , Mimetismo Molecular , Sondas Moleculares/síntese química , Fosforilação , Fitas Reagentes , Sarina/análogos & derivados , Sílica Gel , Solventes , Soman/análogos & derivados , Especificidade por Substrato
8.
Chem Commun (Camb) ; 50(87): 13289-91, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-25233370

RESUMO

Two new Eu(3+) and Au(3+) BODIPY-complexes capable of chromo-fluorogenically detecting micromolar concentrations of V-type nerve agent surrogates by a simple displacement assay are described.


Assuntos
Compostos de Boro/química , Substâncias para a Guerra Química/análise , Európio/química , Ouro/química , Compostos Organometálicos/química , Compostos Organotiofosforados/análise , Estrutura Molecular , Compostos Organometálicos/síntese química
9.
Chemistry ; 20(21): 6339-47, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24700454

RESUMO

Two chromo-fluorogenic probes, each based on the boron dipyrromethene core, have been developed for the detection of nerve-agent mimics. These chemosensors display both a color change and a significant enhancement of fluorescence in the presence of diethylcyanophosphonate (DCNP) and diisopropylfluorophosphate (DFP). No interference from other organophosphorus compounds or acids has been observed. Two portable chemosensor kits have been developed and tested to demonstrate its practical application in real-time monitoring.


Assuntos
Boro/química , Corantes/química , Corantes Fluorescentes , Estrutura Molecular , Fosforilação
11.
Chem Commun (Camb) ; 48(24): 3000-2, 2012 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-22318503

RESUMO

A new selective chromo-fluorogenic probe for Fe(3+), Cr(3+) and Al(3+) is reported. Detection limits are in the µM range and the fluorogenic sensing ability could be observed by the naked eye when illuminated with UV-light. No response is observed with divalent cations.


Assuntos
Alumínio/análise , Cromo/análise , Fluoresceína/química , Corantes Fluorescentes/química , Ferro/análise , Acetonitrilos/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
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