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1.
J Drugs Dermatol ; 15(4): 434-41, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27050698

RESUMEN

BACKGROUND: Hyaluronic acid (HA) is a popular ingredient in topical formulations for cosmetic improvement of the skin. Most formulations contain linear, non-crosslinked HA oligomers, low molecular weight (LMW) HA, and/or high molecular weight (HMW) HA. Crosslinking of HA enhances its clinical longevity and mechanical characteristics. The objective of this study was to characterize the topical effects of a new, crosslinked resilient HA (RHA) that is also available as a cohesive, tissue-integrating injectable filler, compared with non-crosslinked HMW HA and LMW HA. Living human skin explants that preserve the 3-dimensional structure of in vivo skin were used to maximize clinical relevance. METHODS: Standardized doses of each HA product were applied daily for 9 days to human skin explant surfaces. Untreated explants served as controls. Water content of the stratum corneum and entire epidermis was analyzed by Raman spectroscopy. Transepidermal water loss (TEWL) was measured to assess skin barrier function. Explant morphology and microrelief were evaluated by optical and scanning electron microscopy. RESULTS: Crosslinked RHA achieved a significant increase in epidermal water content (7.6%) over the control. Spectral cartography confirmed a higher epidermal water content with RHA than with HMW HA or LMW HA. TEWL was reduced by 27.8% with RHA, and by 15.6% with HMW HA, but increased by 55.5% with LMW HA. Cutaneous microrelief improved with RHA. Corneocyte cohesion improved with RHA and HMW HA. CONCLUSIONS: This comparative, multimodal study demonstrated greater benefits of topical crosslinked RHA over linear HMW HA or LMW HA in reducing TEWL, retaining and redistributing water within the epidermis, maintaining skin integrity, and improving skin barrier structure and function. RHA was a more efficacious humectant than LMW HA, and a more efficacious occlusive moisturizer than HMW HA. These integrative epidermal repair activities are of significant value for addressing primary deficits of aging skin, improving tolerance to retinoids and other topical agents, and optimizing procedural outcomes. A combination of topical and injectable HA provides an elegant model of synergistic, multi-level skin restoration.


Asunto(s)
Reactivos de Enlaces Cruzados/administración & dosificación , Ácido Hialurónico/administración & dosificación , Envejecimiento de la Piel/efectos de los fármacos , Fenómenos Fisiológicos de la Piel/efectos de los fármacos , Pérdida Insensible de Agua/efectos de los fármacos , Administración Cutánea , Anciano , Reactivos de Enlaces Cruzados/química , Composición de Medicamentos , Femenino , Humanos , Ácido Hialurónico/química , Modelos Biológicos , Técnicas de Cultivo de Órganos , Proyectos Piloto , Envejecimiento de la Piel/patología , Pérdida Insensible de Agua/fisiología
2.
Bioorg Med Chem Lett ; 22(12): 3978-82, 2012 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-22608391

RESUMEN

A multi-disciplinary approach was used to identify the first pharmacophore model for KCC2 blockers: several physico-chemical studies such as XRD and NMR were combined to molecular modelling techniques, SAR analysis and synthesis of constrained analogues in order to determine a minimal conformational space regrouping few potential bioactive conformations. These conformations were further compared to the conformational space of a different series of KCC2 blockers in order to identify the common pharmacophoric features. The synthesis of more potent analogues in this second series confirmed the usefulness of this KCC2 blocker pharmacophore model.


Asunto(s)
Anticonvulsivantes/síntesis química , Bloqueadores de los Canales de Potasio/síntesis química , Prolina/análogos & derivados , Prolina/síntesis química , Simportadores/antagonistas & inhibidores , Animales , Anticonvulsivantes/farmacología , Línea Celular Tumoral , Furosemida/farmacología , Ensayos Analíticos de Alto Rendimiento , Humanos , Transporte Iónico/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Bloqueadores de los Canales de Potasio/farmacología , Prolina/farmacología , Ratas , Relación Estructura-Actividad , Simportadores/metabolismo , Difracción de Rayos X , Cotransportadores de K Cl
3.
Langmuir ; 27(19): 12149-55, 2011 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-21902211

RESUMEN

We synthesized new amphiphiles comprised of a single diacetylenic chain and an oligoethylenoxide polar chain linked by an amide bond. In aqueous medium, they are not soluble at room temperature but form weak gels. Electron microscopy studies have shown that they self-assemble into helical tapes or nanotubes with lengths of several micrometers, and inner and outer diameters of 50 ± 1 and 59 ± 1 nm, respectively. The wall has a thickness of 10 ± 1 nm for both kinds of objects and has an amphiphile bilayer structure. The hydrophobic chains are ordered, and the amide groups are linked with each other by H-bonds. The dissociation of the tubes is a first-order transition with an enthalpy of ca. 40 kJ mol(-1). The nanotubes were photopolymerized to yield purple solutions consisting of helical tapes and almost flat ribbons. The polymers exhibit irreversible thermochromism upon heating.


Asunto(s)
Acetileno/química , Óxido de Etileno/síntesis química , Nanotubos/química , Acetileno/análogos & derivados , Amidas/química , Óxido de Etileno/química , Interacciones Hidrofóbicas e Hidrofílicas , Estructura Molecular , Tamaño de la Partícula , Polimerizacion , Propiedades de Superficie
4.
J Chem Inf Model ; 51(12): 3050-9, 2011 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-22077795

RESUMEN

Antioxidative activity expressed as protection of thymidine has been investigated for a set of 30 pulvinic acid derivatives. A combination of in vitro testing and in silico modeling was used for synthesis of new potential antioxidants. Experimental data obtained from a primary screening test based on oxidation under Fenton conditions and by an UV exposure followed by back-titration of the amount of thymidine remaining intact have been used to develop a computer model for prediction of antioxidant activity. Structural descriptors of 30 compounds tested for their thymidine protection activity were calculated in order to define the structure-property relationship and to construct predictive models. Due to the potential nonlinearity, the counter-propagation artificial neural networks were assessed for modeling of the antioxidant activity of these compounds. The optimized model was challenged with 80 new molecules not present in the initial training set. The compounds with the highest predicted antioxidant activity were considered for synthesis. Among the predicted structures, some coumarine derivatives appeared to be especially interesting. One of them was synthesized and tested on in vitro assays and showed some antioxidant and radioprotective activities, which turned out as a promising lead toward more potent antioxidants.


Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacología , Diseño de Fármacos , Lactonas/química , Lactonas/farmacología , Timidina/metabolismo , Línea Celular , Humanos , Peróxido de Hidrógeno/metabolismo , Hierro/metabolismo , Redes Neurales de la Computación , Oxidación-Reducción/efectos de los fármacos , Relación Estructura-Actividad Cuantitativa , Rayos Ultravioleta
5.
Bioorg Med Chem Lett ; 20(8): 2542-5, 2010 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-20299216

RESUMEN

The discovery and optimization of a novel class of selective submicromolar KCC2 blockers is described. Details of synthesis and SAR are given together with ADME properties of selected compounds. A methylsulfone residue on the R(1) phenyl group improved the overall general profile of these prolinate derivatives.


Asunto(s)
Prolina/análogos & derivados , Simportadores/antagonistas & inhibidores , Animales , Prolina/química , Prolina/farmacología , Ratas , Estereoisomerismo , Relación Estructura-Actividad , Cotransportadores de K Cl
6.
Bioorg Med Chem ; 18(22): 7931-9, 2010 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-20965736

RESUMEN

The synthesis of three types of pulvinic acid analogues, using a diversity-oriented strategy starting from a single compound, dimethyl l-tartrate, is described. Lacey-Dieckmann condensation, alcohol dehydration and Suzuki-Miyaura cross-couplings were employed in the course of the analogues syntheses. The evaluation of the antioxidant properties of the 28 synthesized analogues was carried out using antioxidant capacity assays (protection of thymidine and ß-carotene) and free radical scavenging assays (DPPH radical and ABTS radical cation). This allowed to assess the relative influence of the groups bonded to the tetronic ring and to the exocyclic double bond on the activity, as well as the importance of this exocyclic double bond. It was shown that the presence of an electron-donating group on the 3-position of the tetronic ring had a beneficial effect. It was shown in several assays that the presence of the exocyclic bond was not crucial to the activity.


Asunto(s)
Ácidos Carboxílicos/química , Depuradores de Radicales Libres/química , Lactonas/química , Benzotiazoles/química , Compuestos de Bifenilo/química , Ácidos Carboxílicos/síntesis química , Ácidos Carboxílicos/farmacología , Depuradores de Radicales Libres/síntesis química , Depuradores de Radicales Libres/farmacología , Lactonas/síntesis química , Lactonas/farmacología , Picratos/química , Ácidos Sulfónicos/química , Tartratos/química , Timidina/química , beta Caroteno/química , beta Caroteno/metabolismo
7.
Chemistry ; 15(42): 11187-96, 2009 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-19760727

RESUMEN

Syntheses of chiral 6,15-dihydronaphtho[2,3-c]pentaphene derivatives of opposite configurations are reported. Starting from anthracene, the strategy involves two key steps: a Diels-Alder reaction on a prochiral dianthraquinone, and an enantiomeric resolution using (-)-menthol. The final molecules exhibit very strong optical activity, as shown by their circular dichroism spectra, and are examples of chiral facial amphiphiles. Their adsorption at the surface of single-walled carbon nanotubes (SWNTs) has also been studied, and has been found to occur preferentially on 0.8-1.0 nm diameter nanotubes among the population of a high-pressure CO conversion (HiPco) SWNT sample (0.8-1.2 nm). The synthesised facial amphiphiles act as nano-tweezers for the diameter-selective solubilisation of SWNTs in water. The expected optical activities of the SWNT samples solubilised by each of the chiral amphiphiles have been studied by circular dichroism spectroscopy, but the results are not yet conclusive.


Asunto(s)
Antracenos/química , Nanotubos de Carbono/química , Dicroismo Circular , Estereoisomerismo
8.
Org Biomol Chem ; 7(9): 1771-4, 2009 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-19590768

RESUMEN

Functionalized (Z,E)-1-halo-1,3-dienol esters are synthesized in a highly stereoselective manner via CrCl2-mediated rearrangement of allylic trihalomethylcarbinol esters induced by microwave irradiation.


Asunto(s)
Cloruros/química , Compuestos de Cromo/química , Ésteres/síntesis química , Metano/análogos & derivados , Microondas , Ésteres/química , Metano/química , Estructura Molecular , Estereoisomerismo
9.
J Nanosci Nanotechnol ; 9(11): 6777-82, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19908599

RESUMEN

The bundling state of several dry single-walled carbon nanotube (SWNT) samples is compared using isothermal microcalorimetry (IMC). So as to get different dry samples with various bundling states, the pristine SWNTs were pretreated with a solution of an aromatic amphiphile with or without sonication, washed and dried before being studied by IMC. The bundling state of the different SWNT samples, which was first analyzed by TEM, was then correlated to the obtained IMC data thanks to the interpretation of the observed energy transfer phenomena. From our results, IMC appears to be an interesting technique for the surface probing of dry SWNT samples, and herein for the evaluation of the bundling state.

10.
J Org Chem ; 73(23): 9490-3, 2008 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-19007182

RESUMEN

The synthesis of the monoaromatic pulvinic dilactone 1 from a tetronic acid derivative is reported. The reaction of 1 with various amines was found to provide the two pulvinamides regioisomers 2a and 2b. Using tetrabutylammonium fluoride (TBAF) as an activator, pulvinamides 2a could be obtained with excellent regioselectivities and good yields. Additions of alcohols to 1 are also studied, leading to similar observations.


Asunto(s)
Aminas/química , Ácidos Carboxílicos/química , Química Orgánica/métodos , Furanos/química , Lactonas/química , Compuestos de Amonio Cuaternario/química , Alcoholes/química , Amidas/química , Antioxidantes/química , Ácidos Carboxílicos/síntesis química , Hidrólisis , Lactonas/síntesis química , Espectroscopía de Resonancia Magnética , Modelos Químicos , Solventes/química , Temperatura
12.
Chem Biol ; 11(3): 319-26, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15123261

RESUMEN

Cowpea mosaic virus is composed of 60 identical copies of a two-subunit protein organized in pentameric assemblies around the icosahedral 5-fold symmetry axis. Treatment of the virus with the Ni(II) complex of the tripeptide GGH and a peroxide oxidant, or irradiation in the presence of Ru(bpy)(3)(2+) and persulfate generates covalent crosslinks across the pentameric subunit boundaries, effectively stitching the subunits together. Intersubunit crosslinking was found to occur exclusively at adjacent tyrosine residues (Y52-Y103), as predicted from the X-ray crystal structure of the capsid, and to be more extensive with the photochemical ruthenium system. The Ni/GGH oxidative procedure was also used to make covalent attachments to the virion by trapping with a functionalized disulfide reagent.


Asunto(s)
Proteínas de la Cápside/química , Proteínas de la Cápside/metabolismo , Reactivos de Enlaces Cruzados/química , Tirosina/metabolismo , Proteínas de la Cápside/antagonistas & inhibidores , Proteínas de la Cápside/genética , Comovirus/química , Comovirus/genética , Comovirus/metabolismo , Cristalografía por Rayos X , Cisteína/metabolismo , Concentración de Iones de Hidrógeno , Modelos Moleculares , Estructura Molecular , Mutación/genética , Níquel/química , Oxidación-Reducción , Péptidos/química , Péptidos/metabolismo , Fotoquímica , Ácidos Ftálicos/química , Estructura Cuaternaria de Proteína , Rutenio/química , Análisis Espectral , Temperatura , Tirosina/genética , Virión/química , Virión/metabolismo
13.
Org Lett ; 6(16): 2777-9, 2004 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-15281767

RESUMEN

Aryl propargyl ethers and esters are cleaved selectively in the presence of aryl methyl ethers and esters by boron tribromide in dichloromethane. Under the same conditions, allyl ethers undergo very rapid Claisen rearrangement, and benzyl ethers are also cleaved more rapidly than propargyl. A mechanism involving intramolecular delivery of bromide to the propargyl terminus is proposed. [reaction: see text]


Asunto(s)
Compuestos de Boro/química , Bromuros/química , Ésteres/química , Éteres/química , Compuestos Alílicos/química , Compuestos de Bencilo/química , Óxidos
14.
Carbohydr Polym ; 112: 102-8, 2014 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-25129722

RESUMEN

The cetyltrimethylammonium bromide turbidimetric method (CTM) has been developed to quantify the hyaluronic acid (HA) in complex media to overcome the lack of selectivity and specificity of the standard carbazole method. The objective of this work is to assess the potential application of CTM to determine HA concentration. Factors such as duration of incubation, linearity range, HA size and form (natural linear HA or cross linked HA), pH and ionic environment impact were investigated. The incubation time was set to 10 min and the calibration curve was linear up to 0.6 g L(-1). The quantitative method was relevant whatever the HA size and form, and also for a wide range of conditions. The robustness of the CTM added to its high specificity and simplicity demonstrated that the CTM is a valuable method that would be an interesting substitute to the carbazole assay for HA quantification.


Asunto(s)
Compuestos de Cetrimonio/química , Ácido Hialurónico/análisis , Nefelometría y Turbidimetría/métodos , Butileno Glicoles/química , Cetrimonio , Reactivos de Enlaces Cruzados/química , Ácido Hialurónico/química , Concentración de Iones de Hidrógeno , Cinética , Sensibilidad y Especificidad
15.
ChemMedChem ; 6(3): 561-9, 2011 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-21246736

RESUMEN

A high-throughput screening method has highlighted the marked antioxidant activity of some pulvinic acid derivatives (PADs) towards oxidation of thymidine, under γ and UV irradiation, and Fenton-like conditions. Here, we report the synthesis of a series of new hydrophilic PADs and the evaluation of their radioprotective efficacy in cell culture. Using a cell-based fluorescent assay, we show that some of these compounds have a pronounced ability to prevent cell death caused by radiation and to allow the subsequent resumption of proliferation. Thus, PADs may be considered as a novel class of radioprotective agents.


Asunto(s)
Ácidos Carboxílicos/química , Lactonas/química , Protectores contra Radiación/síntesis química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/síntesis química , 4-Butirolactona/química , 4-Butirolactona/farmacología , Ácidos Carboxílicos/síntesis química , Ácidos Carboxílicos/farmacología , Línea Celular , Ensayos Analíticos de Alto Rendimiento , Humanos , Lactonas/síntesis química , Lactonas/farmacología , Fenilacetatos/síntesis química , Fenilacetatos/química , Fenilacetatos/farmacología , Protectores contra Radiación/química , Protectores contra Radiación/farmacología , Rayos Ultravioleta
16.
J Phys Chem B ; 114(17): 5718-22, 2010 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-20380427

RESUMEN

Because they have a great propensity to aggregation in water, solubilization of carbon nanotubes (CNTs) in aqueous media remains an important challenge. Our laboratory has reported the self-organization of synthetic lipids into hemi-micellar structures at the carbon nanotubes surface. Subsequent stabilization of these carbon nanotube/lipid assembly (CNT/LA) constructs is achieved through photopolymerization of the diyne motif of the pentacosa-10,12-diynoic lipids. Herein we investigate the scope of this coating procedure for CNT solubilization. A panel of CNTs was selected according to the method of production and the characteristics of CNTs. The study revealed that it is possible to reach a complete lipid adsorption. The TEM analyses demonstrate that lipid hemi-micellar self-assemblies can be formed around SWNTs as well as around DWNTs and MWNTs, particularly for carbon nanotubes produced by the arc-discharged method. The nanotube suspensions show a very good stability and are homogeneous for months even at a high nanotubes concentration.


Asunto(s)
Lípidos/química , Agua/química , Micelas , Nanotubos de Carbono/química , Solubilidad , Propiedades de Superficie
18.
J Med Chem ; 52(8): 2454-64, 2009 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-19309153

RESUMEN

The natural mushroom pigment Norbadione A and three other pulvinic acids were shown by our group to display very efficient antioxidant properties by comparison with a collection of potent molecules including catechols, flavonoids, stilbenes, or coumarins. Despite numerous publications on robust and straightforward synthetic access to pulvinic acids by us and others, no report has been made to unravel the structure-activity relationships that govern the striking antioxidant activity. Herein is presented the synthesis of 18 diverse pulvinic acid derivatives and the study of their radical scavenging capacities by four different assays. The influence of each of the two phenyl rings, of their substituents and of the lateral chain on the antioxidant properties, was explored to reveal a simplified structure of excellent activity. These results, along with the absence of cytotoxicity, make the synthesized compounds interesting to evaluate for several biological activities and especially for anti-inflammatory effects and skin protection against UV induced oxidative stress.


Asunto(s)
Antioxidantes/síntesis química , Ácidos Carboxílicos/síntesis química , Lactonas/síntesis química , Animales , Antioxidantes/química , Antioxidantes/toxicidad , Células CHO , Ácidos Carboxílicos/química , Ácidos Carboxílicos/toxicidad , Cricetinae , Cricetulus , ADN Superhelicoidal/química , Depuradores de Radicales Libres/síntesis química , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/toxicidad , Lactonas/química , Lactonas/toxicidad , Estrés Oxidativo , Estereoisomerismo , Relación Estructura-Actividad , Superóxidos/química , Timidina/química , Rayos Ultravioleta/efectos adversos
19.
Nat Nanotechnol ; 3(12): 743-8, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19057595

RESUMEN

Amphiphilic molecules-molecules that have both hydrophobic and hydrophilic properties-can self-assemble in water to form diverse structures such as micelles, vesicles and tubes, and these nanostructures can be used for delivering drugs, stabilizing membrane proteins or as nanoreactors. We have previously shown that lipids can self-organize on the surface of single-walled carbon nanotubes into regular ring-shaped assemblies. Here we show that these lipid assemblies can be polymerized and isolated from the nanotube template by application of an electric field. We also demonstrate that these assemblies are monodispersed, water-soluble, and can dissolve various hydrophobic rylene dyes, fullerenes and membrane proteins. The stability of these constructs and their diverse applications will be useful in the fields of cosmetics, medicine and material sciences.


Asunto(s)
Lípidos de la Membrana/química , Nanotecnología/métodos , Nanotubos de Carbono/química , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de la Membrana/química , Microscopía Electrónica de Transmisión , Modelos Moleculares , Polímeros/metabolismo , Sideróforos/química , Solubilidad
20.
Nano Lett ; 8(7): 1830-5, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18540661

RESUMEN

Adsorption of specifically designed and geometrically constrained polyaromatic amphiphiles on single-walled carbon nanotubes (SWNTs) was found to be selective of the nanotube helicity angle. Starting from the same SWNT mixture, photoluminescence and resonant Raman spectroscopies show that a pentacenic-based amphiphile leads to the solubilization of armchair SWNTs and that a quaterrylene-based amphiphile leads to the solubilization of zigzag SWNTs. The results were predicted by the design of the two amphiphiles and are consistent with a supramolecular recognition of the nanotube graphene-type atomic structure by the aromatic part of the molecules through optimized pi-pi-stacking interactions.


Asunto(s)
Nanotubos de Carbono/química , Mediciones Luminiscentes , Modelos Moleculares , Estructura Molecular , Espectrometría Raman
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