Iglesias R.,University of Valladolid |
Citores L.,University of Valladolid |
Ferreras J.M.,University of Valladolid |
Perez Y.,University of Valladolid |
And 7 more authors.
Biochimie | Year: 2010
Sialic acid-binding dwarf elder agglutinin (SEA) present only in rhizomes of the medicinal plant Sambucus ebulus L., was found to be a tetrameric glycoprotein consisting of two covalently-associated dimers of an enzymic A chain with rRNA N-glycosidase activity (EC 220.127.116.11) linked to a B chain with agglutinin properties. The lectin inhibited protein synthesis by a cell-free system and depurinated ribosomes. Cloning of the corresponding gene and molecular modeling of the deduced amino acid sequence demonstrated that SEA has a three-dimensional structure which resembles that reported for other two tetrameric type 2 RIPs from Sambucus (SNAI and SSA). The lectin agglutinated red blood cells and displayed sugar affinity for sialic acid residues apart from d-galactose, binding to the mucin-producing gut goblet cells. Since sialic acid is present in animal cells, especially in epithelial lining gut cells, but not in plants, SEA could play a role in the defense against insect attack. The nucleotide sequence reported in this paper has been submitted to the GenBank nucleotide database under accession number AM981401. © 2009 Elsevier Masson SAS. All rights reserved.
Garcia-Villanova R.J.,Nutricion y Bromatologia |
Mera B.B.,Nutricion y Bromatologia |
Gonzalez Paramas A.M.,Nutricion y Bromatologia |
Hernandez Hierro J.M.,Nutricion y Bromatologia |
And 3 more authors.
Journal of Environmental Monitoring | Year: 2010
This article explains the general difficulties of the Spanish source waters and climatic conditions regarding a control of trihalomethanes (THMs), as reflected by the case of Castilla y León, and how the median values of 75 and 163 μg L -1 of years 1999 and 2002 gave way to the more moderate of 31 and 47 μg L -1 of years 2006 and 2007, respectively - both the latter being measured during the warmer season. Particular circumstances such as raw surface water - with frequently high total organic carbon (T.O.C) values - being the source for 80% of population served, the moderate-to-high water temperatures during the warm seasons and the high chlorine dosages frequently applied account for such as high levels. The median global value (n = 98) for raw water T.O.C. was 4.26 mg L -1 (90th percentile of 9.81 mg L -1) and a median T.O.C. removal of 30% was observed during the treatment, but with an enormous variety (a 90th percentile in the order of 70%). Regression analysis associated the variables raw water temperature, prechlorination dosage and raw and finished water T.O.C. with the THMs measured in the finished waters and in the distribution systems. A certain linear correlation exists between THMs and haloacetic acids (HAAs) contents. However, a shift on their profile is noticeable with the temperature of the water, so that above 11.12 °C, THMs concentration tends to be higher than that of HAAs, and vice versa. © 2010 The Royal Society of Chemistry.
Sanchez-Prado L.,Nutricion y Bromatologia |
Lamas J.P.,Nutricion y Bromatologia |
Garcia-Jares C.,Nutricion y Bromatologia |
Llompart M.,Nutricion y Bromatologia
Chromatographia | Year: 2012
The exceptional properties of the ILs make them ideal for gas chromatography stationary phases. New stationary phases exhibiting good separation selectivity, high efficiency, and high thermal stability are in high demand. Recently, several gas chromatographic capillary columns containing IL stationary phases of various polarities have been introduced on the market. The aim of this work is to extend the applications of the ILs as GC column coatings. The effectiveness of five different commercial IL columns (SLB™-IL59, SLB™-IL76, SLB™-IL82, SLB™-IL100 and SLB™-IL111) for the analysis of two different families of emerging contaminants of environmental concern (plasticizers and synthetic musk fragrances) has been explored. The results obtained for these two families of compounds are compared with the ones obtained when using a (5 %-phenyl)-methylpolysiloxane column. For three of these IL columns, applications have not yet been described. Good resolution for the most of the studied emerging pollutants belonging to five different analytical groups (adipates, phthalates, macrocyclic musks, nitromusks and polycyclic musks) was achieved in all the IL columns. © 2012 Springer-Verlag.
Pena Crecente R.M.,Nutricion y Bromatologia |
Lovera C.G.,Nutricion y Bromatologia |
Garcia J.B.,Nutricion y Bromatologia |
Mendez J.A.,Nutricion y Bromatologia |
And 2 more authors.
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2014
The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption-elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L- 1, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64-22.9 μg Pb L- 1). © 2014 Elsevier B.V.
Alvarez Mendez J.,Nutricion y Bromatologia |
Barciela Garcia J.,Nutricion y Bromatologia |
Garcia Martin S.,Nutricion y Bromatologia |
Pena Crecente R.M.,Nutricion y Bromatologia |
Herrero Latorre C.,Nutricion y Bromatologia
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2015
A new method for the determination of Cd and Pb in urine samples has been developed. The method involves dispersive solid-phase extraction (DSPE), slurry sampling (SS), and subsequent electrothermal atomic absorption spectrometry (ETAAS). Oxidized multiwalled carbon nanotubes (MWCNTs) were used as the sorbent material. The isolated MWCNT/analyte aggregates were treated with nitric acid to form a slurry and both metals were determined directly by injecting the slurry into the ETAAS-atomizer. The parameters that influence the adsorption of the metals on MWCNTs in the DSPE process, the formation and extraction of the slurry, and the ETAAS conditions were studied by different factorial design strategies. The detection and quantification limits obtained for Cd under optimized conditions were 9.7 and 32.3 ng L- 1, respectively, and for Pb these limits were 0.13 and 0.43 μg L- 1. The preconcentration factors achieved were 3.9 and 5.4. The RSD values (n = 10) were less than 4.1% and 5.9% for Cd and Pb, respectively. The accuracy of the method was assessed in recovery studies, with values in the range 96-102% obtained for Cd and 97-101% for Pb. In addition, the analysis of certified reference materials gave consistent results. The DSPE-SS-ETAAS method is a novel and useful strategy for the determination of Pb and Cd at low levels in human urine samples. The method is sensitive, fast, and free of matrix interferences, and it avoids the tedious and time-consuming on-column adsorption and elution steps associated with commonly used SPE procedures. The proposed method was used to determine Cd and Pb in urine samples of unexposed healthy people and satisfactory results were obtained. © 2015 Elsevier B.V.All rights reserved.
Ayala M.D.,University of Murcia |
Abdel I.,University of Murcia |
Santaella M.,Nutricion y Bromatologia |
Martinez C.,Nutricion y Bromatologia |
And 4 more authors.
LWT - Food Science and Technology | Year: 2010
Sea bream, Sparus aurata L., specimens were studied in pre-rigor (3 h) and during the following post-mortem days: 1, 5, 10, 15 and 22. Muscle and textural parameters were evaluated on 6 specimens/stage. Structural results showed scarce fibre-to-fibre detachment on pre-rigor, which increased during the post-mortem degradation. Ultrastructural changes revealed rapid muscle degradation. In pre-rigor myofibrils were detached to both sarcolemma and endomysium. Intermyofibrillar spaces increased and some mitochondriae and sarcoplasmic reticulum were swollen. After 1 day, the sarcolemma appeared occasionally disrupted and the interfibrillar spaces increased. From 5 to 10 days, the I-band and Z line presented some alterations, although these were more severe at 15-22 days. Thus, in these two last stages, loss of I-band, Z line and actin filaments was observed, that coincides with the alteration of the hexagonal arrangement in these advanced stages. Also, the fragmentation of myofibrils increased from 5 to 10 days on. Sarcolemma and endomysium were gradually disrupted throughout the post-mortem stages with total loss at 22 days. Consequently, the interfibrillar spaces increased at last stages. Autophagic mechanisms increased from 5 days on, with an intense destruction of all the intracytoplasmic organelles. Textural parameters decreased from pre-rigor until 5-10 days, mainly associated to detachment of myofibers to sarcolemma-endomysium. © 2009 Elsevier Ltd. All rights reserved.
PubMed | Nutricion y Bromatologia
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2010
The use of acacia wood for the aging of vinegars is increasing because the efficient air transfer through the pores permits a good acetification rate. In this study, vinegars aged in acacia (Robinia pseudoacacia) wood barrels were analyzed and found to contain a characteristic compound, which increased during the aging process. This so far unknown compound was isolated by semipreparative LC and structurally identified by NMR spectroscopy. (1)H and (13)C NMR chemical shifts and optical rotation revealed its structure to be (+)-dihydrorobinetin, a dihydroflavonol identified for the first time in vinegars as a marker of aging in this kind of wood. This study also reports for the first time the complete assignment of (13)C NMR data for this compound. Moreover, it revealed a longer contact time with acacia wood results in higher concentrations of (+)-dihydrorobinetin found in vinegars. Another finding was that the vinegars aged with nontoasted acacia chips showed significantly higher concentrations of (+)-dihydrorobinetin than found in vinegars aged with toasted acacia chips (384.8 and 23.5 mg/L, respectively). The in vitro antioxidant activity (DPPH(*) and ORAC assays) of (+)-dihydrorobinetin was also determined. (+)-Dihydrorobinetin is reported here for the first time as a chemical marker of vinegars aged in acacia wood and can be used for authenticity purposes.