Memòria de l’estada BE 2005

La tècnica de l’Activació Neutrònica (AAN) mitjançant un reactor nuclear és amplament emprada en els estudis sobre ceràmica majòlica. D’aquesta manera es poden atribuir ceràmiques de provinença desconeguda al seu centre productor o fins i tot arribar a discriminar entre diferents tallers o tradicions de producció pertanyent al mateix nucli productor. S’ha analitzat per AAN una mostra composada per individus ceràmics procedents de diversos centres productors de la Península Ibérica. La comparació de les dades obtingudes mitjançant aquest mètode amb les obtingudes amb la tècnica de la Fluorescència de Raigs X (FRX) ha permès aprofundir en el coneixement arqueomètric de les produccions i exportacions de les ceràmiques majòliques de la Península Ibèrica. També s’han realitzat anàlisis sobre la composició química dels vidrats de la ceràmica majòlica a partir de la tècnica de LA-ICP-MS, caracteritzant-ne les diferents decoracions cromàtiques que es troben en el vidrat de cadascuna de les ceràmiques analitzades.

Impacte de l’aplicació de fangs de depuradora en un sòl agrícola

L'elevada quantitat d'aigües residuals generades per la societat actual i el posterior procés de depuració per tal d'eliminar els contaminants de l'aigua, provoca un gran volum de fangs que tradicionalment es duien en un abocador controlat o, pitjor encara, a les zones litorals on es dipositaven directament al mar. La reutilització dels fangs, obtinguts com a subproducte del tractament de les aigües residuals en les EDAR, com a adob biològic en camps agrícoles, és una de les opcions més utilitzades per a la seva gestió. Aquesta, pot ser una bona opció sempre i quan no suposi un risc per la salut, donat que el contingut al fang d'alguns contaminants pot ser elevat i l'acumulació excessiva per exemple d'elements potencialment tòxics (PTE) pot suposar un risc pels sòls i les plantes amb els problemes que això pot ocasionar. Encara que els fangs normalment presenten continguts en PTE inferiors als valors límit establerts per la normativa europea, la seva aplicació reiterada pot suposar un risc d'acumulació dels metalls en el sòl i, depenent de la seva mobilitat, també en les plantes. En aquest projecte, ens centrem en l'estudi de la mobilitat i biodisponibilitat dels metalls en els sòls on s'han cultivat cereals d'hivern, concretament ordi. Els fangs aportats en aquesta experiència són procedents de l'EDAR de Palamós, on reben un tractament de digestió anaeròbia. S'avalua tan el contingut pseudototal de PTE en el sòl, amb l'ajuda d'una digestió al microones, com el contingut de metall biodisponible. A continuació, es determinarà la concentració dels PTE en els extractes mitjançant l'ICP-AES o ICP-MS, depenent de la concentració d'aquests.El projecte es centra en l'avaluació del possible impacte de l'aplicació continuada de biosòlids en sòls agrícoles. Des d'un punt de vista operacional, l'estudi es portarà a terme en parcel•les experimentals situades a l'Estació Experimental Mas Badia, on es porten aplicant fangs de depuradora de manera reiterada durant 12 anys, amb l'objectiu de valorar l'interès agrícola i la incidència agronòmica de l’aplicació de fangs de depuradora en diferents cultius, a mig i a llarg termini

Selenium uptake by edible plants from enriched peat.

As a constituent of selenoproteins, selenium (Se) is considered an essential element for human health.The main way that Se enters the body is via the consumption of vegetables, whose concentration of thiselement depends on soil Se content. We grew cabbage, lettuce, chard and parsley, in peat enriched in Seby means of the additive Selcote Ultra®and Na2SeO3and Na2SeO4. Total Se in plants was determinedby acidic digestion and Se speciation by an enzymatic extraction. Both were measured by ICP/MS. Theconcentration ranges were between 0.1 mg Se kg−1and 30 mg Se kg−1for plants grown in Selcote Ultra®media, and between 0.4 mg Se kg−1and 1606 mg Se kg−1for those grown in peat enriched with Se sodiumsalts. We found Se (IV), Se (VI) and SeMet in all the extracts. Peat fortified with Selcote Ultra®gave slightlyhigher Se concentration than natural content values. For plants grown with selenium sodium salts, Secontent increases with the Se added and part of the inorganic Se was converted mainly to SeMet. A highSe fortification can damage or inhibit plant growth. Cabbage showed the greatest tolerance to Se.

Conjugation of a Ru(II) Arene Complex to Neomycin or to Guanidinoneomycin Leads to Compounds with Differential Cytotoxicities and Accumulation between Cancer and Normal Cells

A straightforward methodology for the synthesis of conjugates between a cytotoxic organometallic ruthenium(II) complex and amino- and guanidinoglycosides, as potential RNA-targeted anticancer compounds, is described. Under microwave irradiation, the imidazole ligand incorporated on the aminoglycoside moiety (neamine or neomycin) was found to replace one triphenylphosphine ligand from the ruthenium precursor [(η6-p-cym)RuCl(PPh3)2]+, allowing the assembly of the target conjugates. The guanidinylated analogue was easily prepared from the neomycin-ruthenium conjugate by reaction with N,N′-di-Boc-N″-triflylguanidine, a powerful guanidinylating reagent that was compatible with the integrity of the metal complex. All conjugates were purified by semipreparative high-performance liquid chromatography (HPLC) and characterized by electrospray ionization (ESI) and matrix-assisted laser desorptionionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and NMR spectroscopy. The cytotoxicity of the compounds was tested in MCF-7 (breast) and DU-145 (prostate) human cancer cells, as well as in the normal HEK293 (Human Embryonic Kidney) cell line, revealing a dependence on the nature of the glycoside moiety and the type of cell (cancer or healthy). Indeed, the neomycinruthenium conjugate (2) displayed moderate antiproliferative activity in both cancer cell lines (IC50 ≈ 80 μM), whereas the neamine conjugate (4) was inactive (IC50 ≈ 200 μM). However, the guanidinylated analogue of the neomycinruthenium conjugate (3) required much lower concentrations than the parent conjugate for equal effect (IC50 = 7.17 μM in DU-145 and IC50 = 11.33 μM in MCF-7). Although the same ranking in antiproliferative activity was found in the nontumorigenic cell line (3 2 > 4), IC50 values indicate that aminoglycoside-containing conjugates are about 2-fold more cytotoxic in normal cells (e.g., IC50 = 49.4 μM for 2) than in cancer cells, whereas an opposite tendency was found with the guanidinylated conjugate, since its cytotoxicity in the normal cell line (IC50 = 12.75 μM for 3) was similar or even lower than that found in MCF-7 and DU-145 cancer cell lines, respectively. Cell uptake studies performed by ICP-MS with conjugates 2 and 3 revealed that guanidinylation of the neomycin moiety had a positive effect on accumulation (about 3-fold higher in DU-145 and 4-fold higher in HEK293), which correlates well with the higher antiproliferative activity of 3. Interestingly, despite the slightly higher accumulation in the normal cell than in the cancer cell line (about 1.4-fold), guanidinoneomycinruthenium conjugate (3) was more cytotoxic to cancer cells (about 1.8-fold), whereas the opposite tendency applied for neomycinruthenium conjugate (2). Such differences in cytotoxic activity and cellular accumulation between cancer and normal cells open the way to the creation of more selective, less toxic anticancer metallodrugs by conjugating cytotoxic metal-based complexes such as ruthenium(II) arene derivatives to guanidinoglycosides.

Caracterizacion quimica de la vidriera del roseton del Duomo de Siena (Italia, 1288-1289)

Se han caracterizado químicamente una colección de vidrios arquitectónicos coloreados originales del rosetón del Duomo (catedral) de Siena, Italia, realizados bajo diseño del artista Duccio di Buoninsegna en 1288-89. Esta comunicación expone los resultados obtenidos mediante el empleo de microsonda electrónica de Castaing (mayoritarios) y espectrometría de masas con fuente de plasma acoplado inductivamente (ICP-MS, elementos en traza) en vidrios de varios colores (incoloro, verde oscuro, verde oliva, amarillo, violeta, rosa, azul oscuro, azul celeste, rojo plaqué). Se trata de vidrios sódico-cálcicos (valores en peso alrededor del 13-14 % de Na2O, 56-64 % SiO2, 4% MgO, 9-10 % CaO, 2,5-4 K2O) de tradición por tanto mediterránea. Un resultado semejante se encontró precedentemente para vidrios realizados a lo largo del siglo XIV, cuanto menos unos 40 años después (vidriera de la iglesia del Monestir de Pedralbes, Barcelona). En general, el estado de conservación de estos vidrios es bueno, excepto por lo que se refiere a la adherencia de las grisallas al vidrio base.

Conjugation of a Ru(II) Arene Complex to Neomycin or to Guanidinoneomycin Leads to Compounds with Differential Cytotoxicities and Accumulation between Cancer and Normal Cells

A straightforward methodology for the synthesis of conjugates between a cytotoxic organometallic ruthenium(II) complex and amino- and guanidinoglycosides, as potential RNA-targeted anticancer compounds, is described. Under microwave irradiation, the imidazole ligand incorporated on the aminoglycoside moiety (neamine or neomycin) was found to replace one triphenylphosphine ligand from the ruthenium precursor [(η6-p-cym)RuCl(PPh3)2]+, allowing the assembly of the target conjugates. The guanidinylated analogue was easily prepared from the neomycin-ruthenium conjugate by reaction with N,N′-di-Boc-N″-triflylguanidine, a powerful guanidinylating reagent that was compatible with the integrity of the metal complex. All conjugates were purified by semipreparative high-performance liquid chromatography (HPLC) and characterized by electrospray ionization (ESI) and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and NMR spectroscopy. The cytotoxicity of the compounds was tested in MCF-7 (breast) and DU-145 (prostate) human cancer cells, as well as in the normal HEK293 (Human Embryonic Kidney) cell line, revealing a dependence on the nature of the glycoside moiety and the type of cell (cancer or healthy). Indeed, the neomycin-ruthenium conjugate (2) displayed moderate antiproliferative activity in both cancer cell lines (IC50 ≈ 80 μM), whereas the neamine conjugate (4) was inactive (IC50 ≈ 200 μM). However, the guanidinylated analogue of the neomycin-ruthenium conjugate (3) required much lower concentrations than the parent conjugate for equal effect (IC50 = 7.17 μM in DU-145 and IC50 = 11.33 μM in MCF-7). Although the same ranking in antiproliferative activity was found in the nontumorigenic cell line (3 2 > 4), IC50 values indicate that aminoglycoside-containing conjugates are about 2-fold more cytotoxic in normal cells (e.g., IC50 = 49.4 μM for 2) than in cancer cells, whereas an opposite tendency was found with the guanidinylated conjugate, since its cytotoxicity in the normal cell line (IC50 = 12.75 μM for 3) was similar or even lower than that found in MCF-7 and DU-145 cancer cell lines, respectively. Cell uptake studies performed by ICP-MS with conjugates 2 and 3 revealed that guanidinylation of the neomycin moiety had a positive effect on accumulation (about 3-fold higher in DU-145 and 4-fold higher in HEK293), which correlates well with the higher antiproliferative activity of 3. Interestingly, despite the slightly higher accumulation in the normal cell than in the cancer cell line (about 1.4-fold), guanidinoneomycin-ruthenium conjugate (3) was more cytotoxic to cancer cells (about 1.8-fold), whereas the opposite tendency applied for neomycin-ruthenium conjugate (2). Such differences in cytotoxic activity and cellular accumulation between cancer and normal cells open the way to the creation of more selective, less toxic anticancer metallodrugs by conjugating cytotoxic metal-based complexes such as ruthenium(II) arene derivatives to guanidinoglycosides.

Study of selenocompounds from selenium-enriched culture of edible sprouts

Selenium is recognised as an essential micronutrient for humans and animals. One of the main sources of selenocompounds in the human diet is vegetables. Therefore, this study deals with the Se species present in different edible sprouts grown in Se-enriched media. We grew alfalfa, lentil and soy in a hydroponic system amended with soluble salts, containing the same proportion of Se, in the form of Se(VI) and Se(IV). Total Se in the sprouts was determined by acidic digestion in a microwave system and by ICP/MS. Se speciation was carried out by enzymatic extraction (Protease XIV) and measured by LC-ICP/MS. The study shows that the Se content of plants depends on the content in the growth culture, and that part of the inorganic Se was biotransformed mainly into SeMet. These results contribute to our understanding of the uptake of inorganic Se and its biotransformation by edible plants.

Standardisation of elemental analytical techniques applied to provenance studies of archaeological ceramics: an inter laboratory calibration study

Chemical analysis is a well-established procedure for the provenancing of archaeological ceramics. Various analytical techniques are routinely used and large amounts of data have been accumulated so far in data banks. However, in order to exchange results obtained by different laboratories, the respective analytical procedures need to be tested in terms of their inter-comparability. In this study, the schemes of analysis used in four laboratories that are involved in archaeological pottery studies on a routine basis were compared. The techniques investigated were neutron activation analysis (NAA), X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). For this comparison series of measurements on different geological standard reference materials (SRM) were carried out and the results were statistically evaluated. An attempt was also made towards the establishment of calibration factors between pairs of analytical setups in order to smooth the systematic differences among the results.

Migration of antimony from polyethylene terephthalate used in mineral water bottles.

The influence of storage time and temperature on Sb migration from PET bottles into mineral water was studied in short-term tests lasting up to 15 days and long-term studies lasting up to 220 days. Samples purchased were stored in three different coloured bottles: clear (CL), light blue (LB) and dark blue (DB). Sb migration was assayed by HG-AFS for total determination and HPLC-ICP-MS for speciation analysis. Migration studies showed that waters stored at 4 and 20 oC were not subject to Sb migration. At 40 oC there was a significant increase in Sb concentration, although the maximum limit established by the European Union (5.0 ug/L) was not exceeded, whereas at 60 oC samples were subject to considerable Sb migration after 30 days of storage. In this case, the maximum limit established by the European Union was exceeded and both Sb (V) and Sb (III) were detected.

Nivel de mercurio en cabello de ninos peruanos expuestos en una zona minera de Arequipa y de la ciudad de Lima

Objetivo: El propósito del estudio fue comparar los niveles de mercurio en cabello en dos muestras de ninos peruanos provenientes de dos zonas geográficas distintas: una zona rural minera y una zona urbana. Material y métodos: La zona minera correspondió al poblado de Mollehuaca (Arequipa), de donde se obtuvieron 52 muestras de cabello; la zona urbana no expuesta a minería correspondió al distrito de Los Olivos (Lima), de donde se obtuvieron 40 muestras. Se determinó el nivel de mercurio con la técnica estandarizada de plasma de inducción acoplado con un espectrómetro de masas (ICP-MS). Resultados: En la zona rural, en promedio, se obtuvo un nivel de mercurio de 7,47 ppb±26,9. En la zona urbana, el nivel de mercurio alcanzó un promedio de 2,47 ppb±1,28. No se encontraron diferencias significatives en el nivel de mercurio según edad o género. Conclusión: Se concluye que el grupo expuesto a minería aurífera informal y de zona rural presentó niveles de mercurio en cabello en promedio mayores a los del grupo de zona urbana, pero esta diferencia no fue significativa (p=0,188, α=0,05).