Platinum (II) and palladium (II) complexes with (N,N') and (C,N,N') ligands derived from pyrazole as anticancer and antimalarial agents: synthesis, characterization and in vitro activities

The study of the reactivity of three 1-(2-dimethylaminoethyl)-1H-pyrazole derivatives of general formula [1-(CH2)2NMe2}-3,5-R2-pzol] {where pzol represents pyrazole and Rdouble bond; length as m-dashH (1a), Me (1b) or Ph (1c)} with [MCl2(DMSO)2] (Mdouble bond; length as m-dashPt or Pd) under different experimental conditions allowed us to isolate and characterize cis-[M{κ2-N,N′-{[1-(CH2)2NMe2}-3,5-R2-pzol])}Cl2] {MMdouble bond; length as m-dashPtPt (2a-2c) or Pd (3a-3c)} and two cyclometallated complexes [M{κ3-C,N,N′-{[1-(CH2)2NMe2}-3-(C5H4)-5-Ph-pzol])}Cl] {Mdouble bond; length as m-dashPt(II) (4c) or Pd(II) (5c)}. Compounds 4c and 5c arise from the orthometallation of the 3-phenyl ring of ligand 1c. Complex 2a has been further characterized by X-ray crystallography. Ligands and complexes were evaluated for their in vitro antimalarial against Plasmodium falciparum and cytotoxic activities against lung (A549) and breast (MDA MB231 and MCF7) cancer cellular lines. Complexes 2a-2c and 5c exhibited only moderate antimalarial activities against two P. falciparum strains (3D7 and W2). Interestingly, cytotoxicity assays revealed that the platinacycle 4c exhibits a higher toxicity than cisplatin in the three human cell lines and that the complex 2a presents a remarkable cytotoxicity and selectivity in lung (IC50 = 3 μM) versus breast cancer cell lines (IC50 > 20 μM). Thus, complexes 2c and 4c appear to be promising leads, creating a novel family of anticancer agents. Electrophoretic DNA migration studies in presence of the synthesized compounds have been performed, in order to get further insights into their mechanism of action.

Identification of myxobacteria-derived HIV inhibitors by a high-throughput two-step infectivity assay

Drug-resistance and therapy failure due to drug-drug interactions are the main challenges in current treatment against Human Immunodeficiency Virus (HIV) infection. As such, there is a continuous need for the development of new and more potent anti-HIV drugs. Here we established a high-throughput screen based on the highly permissive TZM-bl cell line to identify novel HIV inhibitors. The assay allows discriminating compounds acting on early and/or late steps of the HIV replication cycle. The platform was used to screen a unique library of secondary metabolites derived from myxobacteria. Several hits with good anti-HIV profiles were identified. Five of the initial hits were tested for their antiviral potency. Four myxobacterial compounds, sulfangolid C, soraphen F, epothilon D and spirangien B, showed EC50 values in the nM range with SI > 15. Interestingly, we found a high amount of overlapping hits compared with a previous screen for Hepatitis C Virus (HCV) using the same library. The unique structures and mode-of-actions of these natural compounds make myxobacteria an attractive source of chemicals for the development of broad-spectrum antivirals. Further biological and structural studies of our initial hits might help recognize smaller drug-like derivatives that in turn could be synthesized and further optimized.

Plant-derived phenolics inhibit the accrual of structurally characterised protein and lipid oxidative modifications

Epidemiological data suggest that plant-derived phenolics beneficial effects include an inhibition of LDL oxidation. After applying a screening method based on 2,4-dinitrophenyl hydrazine- protein carbonyl reaction to 21 different plant-derived phenolic acids, we selected the most antioxidant ones. Their effect was assessed in 5 different oxidation systems, as well as in other model proteins. Mass-spectrometry was then used, evidencing a heterogeneous effect on the accumulation of the structurally characterized protein carbonyl glutamic and aminoadipic semialdehydes as well as for malondialdehyde-lysine in LDL apoprotein. After TOF based lipidomics, we identified the most abundant differential lipids in Cu++-incubated LDL as 1-palmitoyllysophosphatidylcholine and 1-stearoyl-sn-glycero-3-phosphocholine. Most of selected phenolic compounds prevented the accumulation of those phospholipids and the cellular impairment induced by oxidized LDL. Finally, to validate these effects in vivo, we evaluated the effect of the intake of a phenolic-enriched extract in plasma protein and lipid modifications in a well-established model of atherosclerosis (diet-induced hypercholesterolemia in hamsters). This showed that a dietary supplement with a phenolic-enriched extract diminished plasma protein oxidative and lipid damage. Globally, these data show structural basis of antioxidant properties of plant-derived phenolic acids in protein oxidation that may be relevant for the health-promoting effects of its dietary intake. that a dietary supplement with a phenolic-enriched extract diminished plasma protein oxidative and lipid damage. Globally, these data show structural basis of antioxidant properties of plant-derived phenolic acids in protein oxidation that may be relevant for the health-promoting effects of its dietary intake.

Building complexity in O2-binding copper complexes : site-selective metalation and intermolecular O2-binding at dicopper and heterometallic complexes derived from an unsymmetric ligand

A novel unsymmetric dinucleating ligand (LN3N4) combining a tridentate and a tetradentate binding sites linked through a m-xylyl spacer was synthesized as ligand scaffold for preparing homo- and dimetallic complexes, where the two metal ions are bound in two different coordination environments. Site-selective binding of different metal ions is demonstrated. LN3N4 is able to discriminate between CuI and a complementary metal (M′ = CuI, ZnII, FeII, CuII, or GaIII) so that pure heterodimetallic complexes with a general formula [CuIM′(LN3N4)]n+ are synthesized. Reaction of the dicopper(I) complex [CuI 2(LN3N4)]2+ with O2 leads to the formation of two different copper-dioxygen (Cu2O2) intermolecular species (O and TP) between two copper atoms located in the same site from different complex molecules. Taking advantage of this feature, reaction of the heterodimetallic complexes [CuM′(LN3N4)]n+ with O2 at low temperature is used as a tool to determine the final position of the CuI center in the system because only one of the two Cu2O2 species is formed

Derived categories and Grothendieck duality

"Vegeu el resum a l'inici del document del fitxer adjunt."

Aplicació de la termoquimiolisi - cromatografia de gasos - espectrometria de masses a l'estudi de la matèria orgànica del sòl

Estudi realitzat a partir d’una estada a la Université de Poitiers, França, entre 2007 i 2009. El treball s'ha centrat en dues activitats bàsiques. El treball realitzat s’ha centrat en dues activitats bàsiques. D’una banda, la posada a punt d'un protocol de fraccionament de la matèria orgànica del sòl, per extraccions successives amb solvents alcalins després d'una seqüència de pretractaments al sòl: cap pretractament, atac amb àcid (per destruir els carbonats), atac amb ditionit (per reduir els òxids de Fe i Al i facilitar l'extracció de la matèria orgànica associada a aquests compostos). El protocol dóna una visió de conjunt de la situació de la matèria orgànica del sòl, combinant aspectes físics (protecció, precipitació, oclusió per carbonats) i químics (grau d'humificació). D’altra banda, l'aprenentatge de la tècnica de termoquimiolisi-cromatografia de gasos-espectrometria de masses. Aquest era l'objectiu de l'estada a Poitiers, al qual hem donat prioritat. Ens hem centrat en l'estudi de fraccions físiques (densimètriques) obtingudes en estudis anteriors sobre sòls forestals. Les fraccions considerades són: fracció lleugera (FL), tres fraccions ocluïdes (OC1, OC2 i OC3) i fracció densa (FD). L’aplicació de la termoquimiolisi permet de caracteritzar diversos grups de substàncies, de les quals ens hem centrat en alguns indicadors bioquímics: àcids grasos, alcohols, diàcids, productes fenòlics i altres productes aromàtics, derivats de carbohidrats. L’estudi de conjunt d’aquests productes indica que és a les fraccions ocluïdes (que solen ser minoritàries a tots els horitzons) on la matèria orgànica d’origen microbià és dominant, mentre que a les fraccions lleugera (FL) i densa (FD) la matèria orgànica d’origen vegetal sembla dominant. Es preveu aplicar aquesta tècnica a l’estudi de les fraccions obtingudes a la primera part del treball, actualment congelades i a l’espera de ser processades.

Solid-phase synthesis and NMR studies of modified oligonucleotides forming triplex helix and of oligonucleopeptides mimicking the topoisomerase I-DNA covalent complex

Report for the scientific sojourn carried out at the Institut de Biologia Molecular de Barcelona of the CSIC –state agency – from april until september 2007. Topoisomerase I is an essential nuclear enzyme that modulates the topological status of DNA, facilitating DNA helix unwinding during replication and transcription. We have prepared the oligonucleotide-peptide conjugate Ac-NLeu-Asn-Tyr(p-3’TTCAGAAGC5’)-LeuC-CONH-(CH2)6-OH as model compound for NMR studies of the Topoisomerase I- DNA complex. Special attention was made on the synthetic aspects for the preparation of this challenging compound especially solid supports and protecting groups. The desired peptide was obtained although we did not achieve the amount of the conjugate needed for NMR studies. Most probably the low yield is due to the intrinsic sensitive to hydrolysis of the phosphate bond between oligonucleotide and tyrosine. We have started the synthesis and the structural characterization of oligonucleotides carrying intercalating compounds. At the present state we have obtained model duplex and quadruplex sequences modified with acridine and NMR studies are underway. In addition to this project we have successfully resolved the structure of a fusion peptide derived from hepatitis C virus envelope synthesized by the group of Dr. Haro and we have synthesized and started the characterization of a modified G-quadruplex.

Simultaneous Evaluation of Intact Glucosinolates and Phenolic Compounds by UPLC-DAD-MS/MS in Brassica oleracea L. var. botrytis

A method for the simultaneous determination of intact glucosinolates and main phenolic compounds (flavonoids and sinapic acid derivatives) in Brassica oleracea L. var. botrytis was proposed. A simplified sample extraction procedure and a UPLC separation were carried out to reduce the total time of analysis. Brassica oleracea samples were added with internal standards (glucotropaeolin and rutin), and extracted with boiling methanol. Crude extracts were evaporated under nitrogen, redissolved in mobile phase and analyzed by UPLC with double detection (ESI--MRM for glucosinolates and flavonoids, and DAD for main sinapic acid derivatives). The proposed method allowed a satisfactory quantification of main native sinapic acid derivatives, flavonoids and glucosinolates with a reduced time of analysis.

Obtenció de nous anàlegs amb activitat brassinoesteroide mitjançant modelització molecular i síntesi

Els brassinoesteroides són productes naturals que actuen com a potents reguladors del creixement vegetal. Presenten aplicacions prometedores en l’agricultura degut a que, aplicats exògenament, augmenten la qualitat i la quantitat de les collites. Ara bé, el seu ús s’ha vist restringit degut a la seva costosa obtenció. Aquest fet ha motivat la recerca de nous compostos actius més assequibles. En aquest projecte es planteja el disseny i obtenció de nous anàlegs seguint diferents estratègies que impliquen tant l’ús de mètodes de modelització molecular com de síntesi orgànica. La primera d’aquestes estratègies consisteix en buscar compostos actius en bases de dades de compostos comercials a través de processos de Virtual Screening desenvolupats amb mètodes computacionals basats en Camps d’Interacció Molecular. Així, es van establir i interpretar models de Relacions Quantitatives Estructura-Activitat (QSAR) emprant descriptors independents de l’alineament (GRIND) i, amb col•laboració amb la Universitat de Perugia, aquest criteri de cerca es va ampliar amb l’aplicació de descriptors FLAP de nova generació. Una altra estratègia es va basar en intentar substituir l’esquelet esteroide dels brassinoesteroides per una estructura equivalent, fixant com a cadena lateral el grup (R)-hexahidromandelil. S’han aplicat dos criteris: mètodes computacionals basats en models QSAR establerts amb descriptors GRIND i també en la metodologia SHOP (scaffold hopping), i, per altra banda, anàlegs proposats racionalment a partir d’un estudi efectuat sobre disruptors endocrins no esteroïdals. Sobre les estructures trobades s’hi va unir la cadena lateral comercial esmentada per via sintètica, en la qual s’ha hagut de fer un èmfasi especial en grups protectors. En total, 49 estructures es proposen per a ser obtingudes sintèticament. També s’ha treballat en l’obtenció un agonista derivat de l’hipotètic antagonista KM-01. Totes les molècules candidates, ja siguin comercials o obtingudes sintèticament, estant sent avaluades en el test d’inclinació de la làmina d’arròs (RLIT).

Abundància i persistència de Faecalibacteriun prausnitzii en la Malaltia de Crohn

Faecalibacterium prausnitzii és un del bacteris anaeròbis més abundants entre les espècies comensals del tracte intestinal humà sa. Aquesta espècie és una de les principals productores de butirat a l'intestí (que és la principal font d’energia per als colonòcits), però també s'ha suggerit que pot produir compostos antiinflamatoris i intervenir en la regulació de vàries rutes metabòliques de l’hoste. F. prausnitzii és un bacteri difícil de cultivar, ja que presenta una elevada sensibilitat a l'oxigen i presenta uns requeriments nutricionals molt exigents, el que ha compromès considerablement el nombre d’estudis basats en aïllats d’aquesta espècie. No obstant això, en els darrers anys l’interès en aquest bacteri està creixent ja que s’ha evidenciat que les poblacions de F. prausnitzii són variables en diferents grups d'edat i que es veuen reduïdes en certs trastorns intestinals com ara la malaltia inflamatòria intestinal i el càncer colorectal. L’objectiu d'aquest treball ha estat aprofundir en el rol que desenvolupa F. prausnitzii com un dels principals bacteris comensals del tracte intestinal humà. En primer lloc, s’ha dissenyat, optimitzat i validat un nou mètode molecular per determinar l’abundància d’aquesta espècie en mostres del tracte gastrointesinal, i s’ha demostrat la seva possible aplicació per ajudar al diagnòstic de la malaltia de Crohn. En segon lloc, s’ha dut a terme un estudi de les característiques filogenètiques i fenotípiques dels aïllats de F. Prausnitzii disponibles en l'actualitat a fi de coneixre’n millor la diversitat genètica i fenotípica i dilucidar quins factors són crucials en comprometre la població d’aquest bacteri en un intestí malalt. L’anàlisi de les soques ha revelat que F. prausnitzii inclou Principalment dos filogrups, nutricionalment versàtils i molt sensibles a canvis en les condicions ecològiques que pot patir l’intestí de l’hoste sota certes malalties intestinals. En conclusió, els resultat obtinguts en aquest estudi mostren que F. prausnitzii és una espècie ben establerta al còlon sa, amb una elvada versatilitat metabòlica ja que és capaç d’ interactuar amb carbohidrats de diferent estructura i complexitat. S’ha corroborat que aquest microorganisme seria un bon indicador de salut intestinal ja que la seva abundància es veu significativament reduida en pacients amb malaltia de Crohn. Aquests resultats concorden amb els obtinguts per proves fisiològiques que mostren una elevada sensibilitat de l’espècie a determinades condicions relacionades amb malalties intestinals. Estudis futurs s’orientaran a comprendre millor quins factros derrivats de la interacció amb l’hoste també determinen la persistència d’aquesta espècie en un intestí sa o malalt.

Evaluation of work-related volatile organic compounds (VOCs) exposition in automotive painting cabins industrial cleanings

Automotive painting cabins are cleaned with several solvents, being great part of them mixtures of volatile organic compounds (VOCs), where the three xylene isomers are the most important constituents. To evaluate the work-related exposition of the cleaners that use these mixtures of solvents, xylenes have been determined in the working ambient air as well as its metabolite, o-m-p-methyl hippuric acid, has been analysed in urine to establish the dermal and respiratory exposition. This evaluation has been done in order to assess the occupational exposure to VOCs and to know the working conditions of the cleaners, but also to evaluate the effectiveness of personal protective equipment (PPE), the engineering control and the work practices.The xylenes have been chosen as indicators of exposition because they are the main components in the cleaning solvents used, with a level of concentration between 50% and 85%.The Xylenes have an occupational exposure limit (8 h TWA) of 50 ppm (221 mg/m3) and a short-term exposure limit (STEL) of 100 ppm (442 mg/m3). On the other hand, the biological exposure index (BEI) for xylenes is the sum of the total methyl hippuric acids in urine at the end of the work-shift, being the value 1500 mg/g creatinine.

Reconstruction of a superscheme from its derived category

The aim of this paper is to construct a "super" version of a tensor triangulated category, and to show that super-schemes can be reconstructed from its category of perfect complexes in a way similar to Balmer [Bal05] provided we consider this extra structure.

A comparative analysis by means of quantum molecular similarity measures of density distributions derived from conventional ab initio and density functional methods

A procedure based on quantum molecular similarity measures (QMSM) has been used to compare electron densities obtained from conventional ab initio and density functional methodologies at their respective optimized geometries. This method has been applied to a series of small molecules which have experimentally known properties and molecular bonds of diverse degrees of ionicity and covalency. Results show that in most cases the electron densities obtained from density functional methodologies are of a similar quality than post-Hartree-Fock generalized densities. For molecules where Hartree-Fock methodology yields erroneous results, the density functional methodology is shown to yield usually more accurate densities than those provided by the second order Møller-Plesset perturbation theory

Blood levels of brain-derived neurotrophic factor correlate with several psychopathological symptoms in anorexia nervosa patients

Background: Evidence of a role of brain-derived neurotrophic factor (BDNF) in the pathophysiology of eating disorders (ED) has been provided by association studies and by murine models. BDNF plasma levels have been found altered in ED and in psychiatric disorders that show comorbidity with ED. Aims: Since the role of BDNF levels in ED-related psychopathological symptoms has not been tested, we investigatedthe correlation of BDNF plasma levels with the Symptom Checklist 90 Revised (SCL-90R) questionnaire in a total of 78 ED patients. Methods: BDNF levels, measured bythe enzyme-linked immunoassay system, and SCL-90R questionnaire, were assessed in a total of 78 ED patients. The relationship between BDNF levels and SCL-90R scales was calculated using a general linear model. Results: BDNF plasma levels correlated with the Global Severity Index and the Positive Symptom Distress Index global scales and five of the nine subscales in the anorexia nervosa patients. BDNF plasma levels were able to explain, in the case of the Psychoticism subscale, up to 17% of the variability (p = 0.006). Conclusion: Our data suggest that BDNF levels could be involved in the severity of the disease through the modulation of psychopathological traits that are associated with the ED phenotype.

Altered brain-derived neurotrophic factor blood levels and gene variability are associated with anorexia and bulimia

Murine models and association studies in eating disorder (ED) patients have shown a role for the brain-derived neurotrophic factor (BDNF) in eating behavior. Some studies have shown association of BDNF -270C/T single-nucleotide polymorphism (SNP) with bulimia nervosa (BN), while BDNF Val66Met variant has been shown to be associated with both BN and anorexia nervosa (AN). To further test the role of this neurotrophin in humans, we screened 36 SNPs in the BDNF gene and tested for their association with ED and plasma BDNF levels as a quantitative trait. We performed a family-based association study in 106 ED nuclear families and analyzed BDNF blood levels in 110 ED patients and in 50 sib pairs discordant for ED. The rs7124442T/rs11030102C/rs11030119G haplotype was found associated with high BDNF levels (mean BDNF TCG haplotype carriers = 43.6 ng/ml vs. mean others 23.0 ng/ml, P = 0.016) and BN (Z = 2.64; P recessive = 0.008), and the rs7934165A/270T haplotype was associated with AN (Z =-2.64; P additive = 0.008). The comparison of BDNF levels in 50 ED discordant sib pairs showed elevated plasma BDNF levels for the ED group (mean controls = 41.0 vs. mean ED = 52.7; P = 0.004). Our data strongly suggest that altered BDNF levels modulated by BDNF gene variability are associated with the susceptibility to ED, providing physiological evidence that BDNF plays a role in the development of AN and BN, and strongly arguing for its involvement in eating behavior and body weight regulation.