Facultat de Farmàcia
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Huprine - tacrine heterodimers as anti-amyloidogenic compounds of potential interest against Alzheimer's and prion diseases  

Carles Galdeano, Elisabet Viayna, Irene Sola, Xavier Formosa, Pelayo Camps, Albert Badia, M. Victòria Clos, Júlia Relat, Míriam Ratia, Manuela Bartolini, Francesca Mancini, Vincenza Andrisano, Mario Salmona, Cristina Minguillón, Gema C. González-Muñoz, M. Isabel Rodríguez-Franco, Axel Bidon-Chanal, F. Javier Luque, and Diego Muñoz-Torrero*

* Unitat de Química Farmacèutica, Departament de Farmacologia i Química Terapèutica

Abstract

A family of huprine-tacrine heterodimers has been developed to simultaneously block the active and peripheral sites of acetylcholinesterase (AChE). Their dual site binding for AChE, supported by kinetic and molecular modeling studies, results in a highly potent inhibition of the catalytic activity of human AChE and, more importantly, in the in vitro neutralization of the pathological chaperoning effect of AChE toward the aggregation of both the beta-amyloid peptide (Abeta) and a prion peptide with a key role in the aggregation of the prion protein. Huprine - tacrine heterodimers take on added value in that they display a potent in vitro inhibitory activity toward human butyrylcholinesterase, self-induced Abeta aggregation, and beta-secretase. Finally, they are able to cross the blood-brain barrier, as predicted in an artificial membrane model assay and demonstrated in ex vivo experiments with OF1 mice, reaching their multiple biological targets in the central nervous system. Overall, these compounds are promising lead compounds for the treatment of Alzheimer ' s and prion diseases.

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Identification of new aminoacid amides containing the imidazo[2,1- b ]benzothiazol-2-ylphenyl moiety as inhibitors of tumorigenesis by oncogenic Met signaling

Alessandro Furlan, Francesco Colombo, Andrea Kover, Nathalie Issaly, Cristina Tintori, Lucilla Angeli, Vincent Leroux, Sébastien Letard, Mercedes Amat, Yasmine Asses, Bernard Maigret, Patrice Dubreuil, Maurizio Botta, Rosanna Dono, Joan Bosch,* Oreste Piccolo, Daniele Passarella, Flavio Maina

* Unitat de Química Orgànica, Departament de Farmacologia i Química Terapèutica

Abstract

The Met receptor tyrosine kinase is a promising target in anticancer therapies for its role during tumor evolution and resistance to treatment. It is characterized by an unusual structural plasticity as its active site accepts different inhibitor binding modes. Such feature can be exploited to identify distinct agents targeting tumor dependence and/or resistance by oncogenic Met. Here we report the identification of bioactive agents, featuring a new 4-(imidazo[2,1- b ]benzothiazol-2-yl)phenyl moiety, targeting cancer cells dependent on oncogenic Met. One of these compounds (7c; Triflorcas) impairs survival, anchorage-independent growth, and in vivo tumorigenesis, without showing side effects. Our medicinal chemistry strategy was based on an in-house Met-focused library of aminoacid-amide derivatives enriched through structure-based computer modeling, taking into account the Met multiple-binding-mode feature. Altogether, our findings show how a rational structure-based drug design approach coupled to cell-based drug evaluation strategies can be applied in medicinal chemistry to identify new agents targeting a given oncogenic-dependency setting.

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Long-term treadmill exercise induces neuroprotective molecular changes in rat brain  

S. Bayod, J. del Valle, A. M. Canudas, J. F. Lalanza, S. Sanchez-Roige, A. Camins, R. M. Escorihuela, and M. Pallàs *

* Departament de Farmacologia i Química Terapèutica, Unitat de Farmacologia i Farmacognòsia

Abstract

Exercise enhances general health. However, its effects on neurodegeneration are controversial, and the molecular pathways in the brain involved in this enhancement are poorly understood. Here, we examined the effect of long-term moderate treadmill training on adult male rat cortex and hippocampus to identify the cellular mechanisms behind the effects of exercise. We compared three animal groups: exercised (30 min/day, 12 m/min, 5 days/wk, 36 wk), handled but nonexercised (treadmill handling procedure, 0 m/min), and sedentary (nonhandled and nonexercised). Moderate long-term exercise induced an increase in IGF-1 levels and also in energy parameters, such as PGC-1alpha and the OXPHOS system. Moreover, the sirtuin 1 pathway was activated in both the exercised and nonexercised groups but not in sedentary rats. This induction could be a consequence of exercise as well as the handling procedure. To determine whether the long-term moderate treadmill training had neuroprotective effects, we studied tau hyperphosphorylation and GSK3beta activation. Our results showed reduced levels of phospho-tau and GSK3beta activation mainly in the hippocampus of the exercised animals. In conclusion, in our rodent model, exercise improved several major brain parameters, especially in the hippocampus. These improvements induced the upregulation of sirtuin 1, a protein that extends life, the stimulation of mitochondrial biogenesis, the activation of AMPK, and the prevention of signs of neurodegeneration. These findings are consistent with other reports showing that physical exercise has positive effects on hormesis.

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A metabolomic approach differentiates between conventional and organic ketchups

Anna Vallverdú-Queralt, Alexander Medina-Remón, Isidre Casals-Ribes, Mercedes Amat, and Rosa Maria Lamuela-Raventós*

* Departament de Nutrició i Bromatologia

Abstract

The agronomic environments in which tomatoes are cultivated potentially affect the levels of antioxidants and other metabolites in commercial products. In this study, biochemical and metabolomic techniques were used to assess the differences between ketchups produced by organic and conventional systems. An untargeted metabolomic approach using QToF-MS was used to identify those nutrients that have the greatest impact on the overall metabolomic profile of organic ketchups as compared to conventional ones. Individual polyphenols were quantified using LC-ESI-QqQ. This multifaceted approach revealed that the agronomic environment in which tomatoes are grown induces alterations in the content of antioxidant capacity, phenolics, and other metabolites in ketchups. Organic cultivation was found to provide tomatoes and tomato-derived products with a significantly higher content of antioxidant microconstituents, whereas glutamylphenylalanine and N-malonyltryptophan were detected only in conventional ketchups.

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Total synthesis of Aeruginazole A  

Paolo Bruno, Stella Peña, Xavier Just-Baringo, Fernando Albericio, and Mercedes Álvarez*

* Unitat de Química Orgànica, Departament de Farmacologia i Química Terapèutica

Abstract

The first total synthesis of Aeruginazole A, prepared via a convergent strategy that involved both solid-phase peptide synthesis and solution phase chemistry and that enabled conservation of the stereochemistry of the intermediates, is reported.

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Highly stereoselective double ( R )-phenylglycinol-induced cyclocondensation reactions of symmetric aryl bis(oxoacids)  

Mercedes Amat,* Carlos Arróniz, Elies Molins, Carmen Escolano* and Joan Bosch

* Unitat de Química Orgànica, Departament de Farmacologia i Química Terapèutica

Abstract

The double cyclocondensation of symmetric pyridyl bis(oxoacids) 2b and 3b with ( R )-phenylglycinol stereoselectively gave access to bis-phenylglycinol-derived oxazolopyrrolidine 9 and oxazolopiperidone 10 , respectively. Application of the stereocontrolled cyclocondensation reaction to phenyl bis- gamma -oxoacid 4b provided 11 , which was converted to the corresponding enantiopure di(pyrrolidinyl)benzene 22 . The absolute configuration of the new stereogenic centers generated in the key cyclocondenstion step was unambiguously established by X-ray crystallographic analysis .

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Progress on lamellarins  

Daniel Pla, Fernando Albericio, and Mercedes Álvarez*

* Unitat de Química Orgànica, Departament de Farmacologia i Química Terapèutica

Abstract

This review covers recent literature on the lamellarins, a family of marine natural products, and related analogs, encompassing synthetic strategies for total synthesis, structure–activity relationships (SAR), and studies on mechanisms of biological action, namely in the context of anti-tumor activity. It reviews work published from January 2008 to December 2010.

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Effect of E1(64–81) hepatitis G peptide on the in vitro interaction of HIV-1 fusion peptide with membrane models. 

Maria Jesús Sánchez-Martín,* M. Antònia Busquets, Victoria Girona, Isabel Haro, M. Asunción Alsina, Montserrat Pujol

* Departament de Fisicoquímica

Abstract

One way to gain information about the fusogenic potential of virus-derived synthetic peptides is to examine their interfacial properties and subsequently to study them in monolayers and bilayers. Here, we characterize the physicochemical surface properties of the peptide E1(64–81), whose sequence is AQLVGELGSLYGPLSVSA. This peptide is derived from the E1 structural protein of GBV-C/HGV which was previously shown to inhibit leakage of vesicular contents caused by the HIV-1 fusion peptide (HIV-1 FP). Mixed isotherms of E1(64–81) and HIV-1 FP were obtained and their Brewster angle microscopy (BAM) and atomic force microscopy (AFM) images showed that the peptide mixture forms a different structure that is not present in the pure peptide images. Studies with lipid monolayers (1,2-dimyristoyl- sn -glycero-3-[phospho-rac-(1-glycerol)] (DMPG) and 1,2-dipalmitoyl- sn -glycero-3-phospho- rac -(1-glycerol) (DPPG)) show that both peptides interact with all the lipids assayed but the effect that HIV-1 FP has on the monolayers is reduced in the presence of E1(64–81). Moreover, differential scanning calorimetry (DSC) experiments show the capacity of HIV-1 FP to modify the properties of the bilayer structure and the capacity of E1(64–81) to inhibit these modifications. Our results indicate that E1(64–81) interacts with HIV-1 FP to form a new structure, and that this may be the cause of the previously observed inhibition of the activity of HIV-1 FP by E1(64–81).

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Analysis of HIV-1 fusion peptide inhibition by synthetic peptides from E1 protein of GB virus C  

Maria Jesús Sánchez-Martín,* Kalina Hristova, Montserrat Pujol, Maria J. Gómara, Isabel Haro, M. Asunción Alsina, M. Antònia Busquets

* Departament de Fisicoquímica

Abstract

The aim of this study was to identify proteins that could inhibit the activity of the peptide sequence representing the N-terminal of the surface protein gp41 of HIV, corresponding to the fusion peptide of the virus (HIV-1 FP). To do this we synthesized and studied 58 peptides corresponding to the envelope protein E1 of the hepatitis G virus (GBV-C).

Five of the E1 synthetic peptides: NCCAPEDIGFCLEGGCLV (P7), APEDIGFCLEGGCLVALG (P8), FCLEGGCLVALGCTICTD (P10), QAGLAVRPGKSAAQLVGE (P18) and AQLVGELGSLYGPLSVSA (P22) were capable of inhibiting the leakage of vesicular contents caused by HIV-1 FP. A series of experiments were carried out to determine how these E1 peptides interact with HIV-1 FP. Our studies analyzed the interactions with and without the presence of lipid membranes. Isothermal titration calorimetry revealed that the binding of P7, P18 and P22 peptides to HIV-1 FP is strongly endothermic, and that binding is entropy-driven. Gibbs energy for the process indicates a spontaneous binding between E1 peptides and HIV-1 FP. Moreover, confocal microscopy of Giant Unilamellar Vesicles revealed that the disruption of the lipid bilayer by HIV-1 FP alone was inhibited by the presence of any of the five selected peptides.

Our results highlight that these E1 synthetic peptides could be involved in preventing the entry of HIV-1 by binding to the HIV-1 FP. Therefore, the continued study into the interaction between GBV-C peptides and HIV-1 FP could lead to the development of new therapeutic agents for the treatment of AIDS.

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Comparative sensitivity of tumor and non-tumor cell lines as a reliable approach for in vitro cytotoxicity screening of lysine based surfactants with potential pharmaceutical applications  

Daniele Rubert Nogueira , Montserrat Mitjans, M. Rosa Infante, M. Pilar Vinardell*

* Departament de Fisiologia

Abstract

Surfactants are used as additives in topical pharmaceuticals and drug delivery systems. The biocompatibility of amino acid-based surfactants makes them highly suitable for use in these fields, but tests are needed to evaluate their potential toxicity. Here we addressed the sensitivity of tumor (HeLa, MCF-7) and non-tumor (3T3, 3T6, HaCaT, NCTC 2544) cell lines to the toxic effects of lysine-based surfactants by means of two in vitro endpoints (MTT and NRU). This comparative assay may serve as a reliable approach for predictive toxicity screening of chemicals prior to pharmaceutical applications. After 24-h of cell exposure to surfactants, differing toxic responses were observed. NCTC 2544 and 3T6 cell lines were the most sensitive, while both tumor cells and 3T3 fibroblasts were more resistant to the cytotoxic effects of surfactants. IC50-values revealed that cytotoxicity was detected earlier by MTT assay than by NRU assay, regardless of the compound or cell line. The overall results showed that surfactants with organic counterions were less cytotoxic than those with inorganic counterions. Our findings highlight the relevance of the correct choice and combination of cell lines and bioassays in toxicity studies for a safe and reliable screen of chemicals with potential interest in pharmaceutical industry.

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Stereocontrolled generation of benzo[ a ]- and indolo[2,3- a ]quinolizidines from ( S )-tryptophanol and ( S )-(3,4-dimethoxyphenyl)alaninol-derived lactams

Maria Pérez, Federica Arioli, Gianna Rigacci, Maria M. M. Santos, Arantxa Gómez-Esqué, Carmen Escolano, Pedro Florindo, Carlos Ramos, Joan Bosch, and Mercedes Amat *

* Unitat de Química Orgànica, Departament de Farmacologia i Química Terapèutica

Abstract

The stereochemical outcome of Pictet-Spengler cyclizations of ( S )-tryptophanol and ( S )-(3,4-dimethoxyphenyl)alaninol-derived lactams is discussed. When using HCl the respective trans -H-6/H-12b (or H-11b) indolo[2,3- a ]- or benzo[ a ]quinolizidines are stereoselectively formed, whereas BF3 · Et2O-promoted cyclizations lead to trans -H-6/H-11b benzo[ a ]quinolizidines but cis -H-6/H-12b indolo[2,3- a ]quinolizidines. The intermediacy of an oxazolinium salt in the latter process is demonstrated.

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Human HMGCS2 regulates mitochondrial fatty acid oxidation and FGF21 expression in HepG2 cell line

Anna Vilà-Brau, Ana Luísa De Sousa-Coelho, Cristina Mayordomo, Diego Haro, and Pedro F. Marrero *

* Departament de Bioquímica i Biologia Molecular

Abstract

HMGCS2 (hydroxymethylglutaryl CoA synthase 2), the gene that regulates ketone body production, is barely expressed in cultured cell lines. In this study, we restored HMGCS2 expression and activity in HepG2 cells, thus showing that the wild type enzyme can induce fatty acid beta -oxidation (FAO) and ketogenesis, whereas a catalytically inactive mutant C166A did not generate either process. Peroxisome proliferator-activated receptor (PPAR) alpha expression also induces fatty acid beta -oxidation and endogenous HMGCS2 expression. Interestingly, PPAR alpha -mediated induction was abolished when HMGCS2 expression was down-regulated by RNAi. These results indicate that HMGCS2 expression is both sufficient and necessary to the control of fatty acid oxidation in these cells. Next, we examined the expression pattern of several PPAR alph a target genes in this now “ketogenic” HepG2 cell line. FGF21 (fibroblast growth factor 21) expression was specifically induced by HMGCS2 activity or by the inclusion of the oxidized form of ketone bodies (acetoacetate) in the culture medium. This effect was blunted by SirT1 (sirtuin 1) RNAi, so we propose a SirT1-dependent mechanism for FGF21 induction by acetoacetate. These data suggest a novel feed-forward mechanism by which HMGCS2 could regulate adaptive metabolic responses during fasting. This mechanism could be physiologically relevant, because fasting-mediated induction of liver FGF21 was dependent on SirT1 activity in vivo .

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Conservation assessment of Aquilegia paui ( Ranunculaceae): a case study of an extremely narrow endemic.

Martinell, MC, López-Pujol, J., Blanché, C.*, Molero, J. & Sàez, L.

*Departament de Productes Naturals, Biologia Vegetal i Edafologia

Abstract

The extremely rare Aquilegia paui (Ranunculaceae) was described in 1920 but was not found again until 1999, when it was discovered in the Parc Natural dels Ports in Tarragona Province, Spain. This species had been confused with the widespread A. vulgaris and consequently its taxonomic and conservation status had been misinterpreted. Based on the limited range of A. paui and the level of disturbance of its habitat we recommend that it is categorized as Endangered on the IUCN Red List. We summarize the conservation actions available for such extremely narrow endemic plant species and make appropriate recommendations for the conservation of A. paui.

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Biodegradable chelate enhances the phytoextraction of copper by Oenothera picensis grown in copper-contaminated acid soils

Isabel González, Amparo Cortés, Alexander Neaman, Patricio Rubio

Departament de Productes Naturals, Biologia Vegetal i Edafologia, Unitat d'Edafologia i Química Agrícola

Abstract

Oenothera picensis plants (Fragrant Evening Primrose) grow in the acid soils contaminated by copper smelting in the coastal region of central Chile. We evaluated the effects of the biodegradable chelate MGDA (methylglycinediacetic acid) on copper extraction by O. picensis and on leaching of copper through the soil profile, using an ex situ experiment with soil columns of varying heights. MGDA was applied in four rates: 0 (control), 2, 6 and 10 mmol/plant. MGDA application significantly increased biomass production and foliar concentration, permitting an effective increase in copper extraction, from 0.09 mg/plant in the control, to 1.3 mg/plant in the 6 and 10 mmol/plant treatments. With 10 mmol/plant rate of MGDA, the copper concentration in the leachate from the 30 cm columns was 20 times higher than

in the control. For the 60 cm columns, copper concentration was 2 times higher than the control. It can be concluded that at increased soil depths, copper leaching would be minimal and that MGDA applications at the studied rates would not pose a high risk for leaching into groundwater. It can thus be stated that applications of MGDA are an effective and environmentally safe way to improve copper extraction by O. picensis in these soils.

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