Browsing by Subject "Iron"
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- PublicationOpen AccessAssembly of Heterometallic Rigid-Rod Complexes and Coordination Oligomers from Gold(I) Metalloligands(American Chemical Society, 2015-06-18) Cámara, Verónica; Barquero, Natalia; Bautista, Delia; Gil-Rubio, Juan; Vicente, José; Química InorgánicaThe reactions of TpylC6H4C≡CAuL (Tpyl = 2,2':6',2''-terpyridin-4'-yl; L = PPh3, CNXy; Xy = 2,6-dimethylphenyl) with MX2·nH2O (M = Fe, X = ClO4; M = Co, X = BF4; M = Zn, X = TfO, ClO4) in a 2:1 molar ratio give complexes [M(TpylC6H4C≡CAuL)2]X2. Similarly, the reactions of PPN[(TpylC6H4C≡C)2Au] (PPN = (Ph3P)2N) with an equimolar amount of MX2·nH2O give coordination oligomers [M{(TpylC6H4C≡C)2Au}]nXn (M = Fe, Zn, X = ClO4; M = Co, X = BF4). The complexes and oligomers have been isolated and characterized. The crystal structures of [Fe(TpylC6H4C≡CAuCNXy)2](ClO4)2 and [Co(TpylC6H4C≡CAuPPh3)2](BF4)2 have been determined by X-ray diffraction. The hydrodynamic sizes of complexes [M(TpylC6H4C≡CAuPPh3)2]X2 and coordination oligomers [M{(TpylC6H4C≡C)2 Au}]nXn have been studied by NMR diffusion spectroscopy and Dynamic Light Scattering (DLS) measurements.
- PublicationOpen AccessDistribution of ferric iron in larval lampreys, Petromyzon marinus L(Murcia : F. Hernández, 1988) Hall, S.J.; Youson, J.H.The distribution and abundance of ferric iron in larval lampreys (Petromyzon marinus L.) were investigated using light microscopy and the Prussian blue stain. Animals from various watersheds contained different concentrations of iron, although the sites of deposition were the same for all animals. A major portion of iron is within adipose tissue. while the liver, and cartilage contain predominantly low to trace amounts of iron. respectively. Iron is associated with fibrous connective tissue in several places in the body, and this association may have particular significance in the inner ear. Iron is also located in cells of the meninges. The presence of iron in the epithelia1 cells of the posterior intestine may reflect elimination of the metal through the extrusion of iron-loaded cells into the intestinal lumen. Iron within mucous cells of the epidermis, suggest elimination of iron during mucous secretion. Iron-loaded cells of bipolar shape are also present in the epidermis, but are particularly prominent around the branchiopore. Low concentrations of iron are observed within in melanin-containing macrophages (melano-macrophages) in regions of iron absorption, erythrophagocytosis, and haemopoiesis. High levels of iron in the epithelia and lumina of pronephric tubules are concomitant with degeneration of this organ. These data are evidence of the wide spread distribution of iron in lamprey tissues and additional evidence for the potential value of lampreys for the study of iron metabolism in vertebrates.
- PublicationRestrictedEffect of Dephytinization and Follow-on Formula Addition on in Vitro Iron, Calcium, and Zinc Availability from Infant Cereals(American Chemical Society, 2008-04-24) Frontela Saseta, María del Carmen; Ros Berruezo, Gaspar; Martínez Gracia, Carmen; Haro Vicente, Juan Francisco; Tecnología de Alimentos, Nutrición y BromatologíaCereals are introduced to infants between the ages of 4 and 6 months to supplement breast milk and follow-on formula. Our objectives were to examine the content and in vitro availability of Fe, Ca, and Zn from five commercially available infant cereals mixed with water or follow-on formula before and after dephytinization. We estimated the bioaccessibility by measuring the soluble or dialyzable mineral fraction resulting from in vitro gastrointestinal digestion of the sample. For most infant cereals analyzed, dephytinization increased the in vitro availability of iron and zinc. This finding was especially dramatic among infant cereals mixed with follow-on formula rather than with water. However, the liquid used for reconstitution did not always show a significant (p < 0.05) interaction with phytase addition and in vitro mineral availability. The results of this study indicate that adding follow-on formula to infant cereals does not improve the bioaccessibility of iron, calcium, and zinc, despite the increase in mineral content it implies. Results obtained also showed that mineral solubility and dialyzability do not always follow parallel trends.
- PublicationOpen AccessEffect of dephytinization on bioavailability of iron, calcium and zinc from infant cereals assessed in the Caco-2 cell model(Baishideng Publishing Group, 2019-04-28) Frontela Saseta, María del Carmen; Scarino,Maria Laura; Ferruzza, Simonetta; Ros Berruezo, Gaspar; Martínez Gracia, Carmen; Tecnología de Alimentos, Nutrición y BromatologíaAIM: To test the effect of the dephytinization of three different commercial infant cereals on iron, calcium, and zinc bioavailability by estimating the uptake, retention, and transport by Caco-2 cells. METHODS: Both dephytinized (by adding an exogenous phytase) and non-dephytinized infant cereals were digested using an in vitro digestion protocol adapted to the gastrointestinal conditions of infants younger than 6 mo. Mineral cell retention, transport, and uptake from infant cereals were measured using the soluble fraction of the simulated digestion and the Caco-2 cells. RESULTS: Dephytinization of infant cereals significantly increased (P < 0.05) the cell uptake efficiency (from 0.66%-6.05% to 3.93%-13%), retention (from 6.04%-16.68% to 14.75%-20.14%) and transport efficiency (from 0.14%-2.21% to 1.47%-6.02%), of iron, and the uptake efficiency (from 5.0%-35.4% to 7.3%-41.6%) and retention (from 4.05%-20.53% to 14.45%-61.3%) of zinc, whereas calcium only cell uptake showed a significant increase (P < 0.05) after removing phytate from most of the samples analyzed. A positive relationship (P < 0.05) between mineral solubility and the cell uptake and transport efficiencies was observed. CONCLUSION: Removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. Since in developing countries cereal-based complementary foods for infants are usually consumed mixed with water, exogenous phytase additions could improve the nutritional value of this weaning food
- PublicationOpen AccessFerrioxalate Photocatalysis: A Multitasking Platform for Reductive Iron Catalysis(AAAS, 2026-01-01) Carlos Bernabeu; Sergio Adalid; Sara Colombo; Nojus Cironis; Partha Pratim Sen; Ken Okuno; Fabio Juliá; Juliá Hernández, Fabio; Fabio Juliá; Química Inorgánica; Fabio Juliá; Facultades de la UMU::Facultad de QuímicaIron’s abundance motivates its use in sustainable catalyst systems that also offer complementary reactivity manifolds compared to precious metals. However, the challenging reduction of benchmark iron salts to active species hinders their application in reductive transformations. Here we report a photochemical strategy that exploits the innate reactivity of ligand-to-metal charge-transfer (LMCT) excited states of iron oxalate complexes to harness oxalate salts as latent terminal 2-electron reductants in iron catalysis. The investigation of this activation mode has led to the development of a versatile catalytic platform enabling transformations hitherto inaccessible to previous iron catalyst systems. The synthetic value of this tactic is demonstrated on diverse reductive transformations using readily available building blocks with high chemoselectivity, opening new synthetic opportunities.
- PublicationRestrictedIron and calcium availability from digestion of infant cereals by Caco-2 cells(Springer Nature, 2009-01-09) Frontela Saseta, María del Carmen; Ros Berruezo, Gaspar; Martínez Gracia, Carmen; Tecnología de Alimentos, Nutrición y BromatologíaAn adequate mineral intake during infancy is needed for normal growth and development. This study investigated the eVect of dephytinization of four infant cereals and the use of water and follow-on formula as the liquid of reconstitution on the intestinal cell uptake of iron and calcium from infant cereals using a model that combines a simulated gastrointestinal digestion adapted to the gastrointestinal conditions of infants younger than 6 months and the Caco-2 cell line. Iron and calcium uptake by Caco-2 cells from most infant cereals was signiWcantly (p < 0.05) improved when a phytase was added. When infant cereals were reconstituted with water, dephytinization increased iron (3.2–19.5 vs. 3–10%) and calcium (0.66–2.3 vs. 0.35–0.59%) availability compared to the same infant cereals reconstituted with a follow-on formula. We can conclude that dephytinization of infant cereals and water addition improved iron and calcium availability, depending on the infant cereal used.
- PublicationOpen AccessIron in the migraine brain(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Tepe, Nermin; Yemisci, Muge; Karatas, HulyaIron, a vital element for numerous peripheral and central nervous system functions, is a key player in DNA synthesis, gene expression, myelination, neurotransmission, and mitochondrial electron transport. Iron has utmost importance in various neurological functions, including neurotransmitter synthesis and brain cell metabolism. Migraine is a neurogliovascular disorder in which neuroinflammation plays a crucial role. Iron deficiency has been associated with various neurological issues and could potentially influence migraine frequency or severity. However, the relationship between iron levels and migraine is not fully clear and necessitates further research. On the other hand, iron overload could also have negative effects, as excessive iron might contribute to oxidative stress and inflammation, which may impact migraine-related pathways. The interplay between iron levels and neuroinflammation might affect migraines. While iron deficiency could exacerbate inflammation or disrupt neurotransmitter balance, iron overload might increase oxidative stress and neuroinflammation. Comprehending this balance is fundamental, as both iron deficiency and overload can have detrimental effects on brain health and migraine symptoms. In this review, we will summarize the current interconnection between migraine, iron levels, and neuroinflammation that are currently under active investigation
- PublicationOpen Accesslron deprivation and cancer: a view beginning with studies of monoclonal antibodies against the transferrin receptor(Murcia : F. Hernández, 1997) Kemp, J.D.This review provides a perspective on the potential utility of iron deprivation treatments as components of cancer therapy. The perspective began to develop with investigations of the selective inhibitory effects on lymphocyte activation which were produced by rnonoclonal antibodies against the transferrin receptor. Those investigations led to the unexpected discovery that such antibodies would produce synergistic inhibition of lymphoid tumor growth in vitro when used in combination with the iron chelator deferoxamine. The perspective was further developed whea additional studies in vivo indicated that combination iron deprivation treatrnent could prevent initial tumor outgrowth and cause regressions of established tumors in the 38C13 rnurine lymphorna model. The anti-tumor effects were accompanied by significant toxicities, however, and the analysis of the causes of those toxicities is now an irnportant issue. The opportunities and problerns which these results present are interpreted in the broader context of currently available information conceming the anti-tumor effects of deferoxamine and gallium nitrate in the pre-clinical and clinical settings, and questions for future research are presented.
- PublicationRestrictedPhytic acid and inositol phosphates in raw flours and infant cereals: the effect of processing(Elsevier, 2008-03-04) Frontela Saseta, María del Carmen; García Alonso, Francisco Javier; Ros Berruezo, Gaspar; Martínez Gracia, Carmen; Tecnología de Alimentos, Nutrición y BromatologíaInositol phosphate modification in infant cereals was examined during industrial processing which included roasting and alphaamylase treatment. A considerable (po0.05) decrease in phytate content was observed after both treatments in all the samples analysed. However, the industrial processing observed was not sufficient to cause degradation of the phytate to achieve phytate mineral ratios optimal for mineral absorption in infant cereals. All samples analysed had a phytate/iron molar ratio 41.3, and of the 6 samples, 5 had a phytate/zinc molar ratio 414. The bioavailability of minerals is particularly important during weaning when minerals stores in infants are naturally low. Further studies are needed to evaluate the efficacy and effectiveness of phytase treatment to increase mineral bioavailability in infant foods.
- PublicationOpen AccessRegional brain iron and gene expression provide insights into neurodegeneration in Parkinson’s disease(Oxford Univeristy Press, 2021-03-11) Thomas, George E.C.; Zarkali, Angeliki; Ryten, Mina; Shmueli, Karin; Gil Martínez, Ana Luisa; Leyland, Louis-Ann; McColgan, Peter; Acosta-Cabronero, Julio; Lees, Andrew J.; Weil, Rimona S.; Ingeniería de la Información y las ComunicacionesThe mechanisms responsible for the selective vulnerability of specific neuronal populations in Parkinson’s disease are poorly understood. Oxidative stress secondary to brain iron accumulation is one postulated mechanism. We measured iron deposition in 180 cortical regions of 96 patients with Parkinson’s disease and 35 control subjects using quantitative susceptibility mapping. We estimated the expression of 15 745 genes in the same regions using transcriptomic data from the Allen Human Brain Atlas. Using partial least squares regression, we then identified the profile of gene transcription in the healthy brain that underlies increased cortical iron in patients with Parkinson’s disease relative to controls. Applying gene ontological tools, we investigated the biological processes and cell types associated with this transcriptomic profile and identified the sets of genes with spatial expression profiles in control brains that correlated significantly with the spatial pattern of cortical iron deposition in Parkinson’s disease. Gene ontological analyses revealed that these genes were enriched for biological processes relating to heavy metal detoxification, synaptic function and nervous system development and were predominantly expressed in astrocytes and glutamatergic neurons. Furthermore, we demonstrated that the genes differentially expressed in Parkinson’s disease are associated with the pattern of cortical expression identified in this study. Our findings provide mechanistic insights into regional selective vulnerabilities in Parkinson’s disease, particularly the processes involving iron accumulation.
- PublicationOpen AccessLa tumba de hierro del empresario Francisco Peña Vaquero(Universidad de Murcia. Servicio de Publicaciones, 2021) Palazón Botella, Mª Dolores; Molina Gómez, José AntonioEl cementerio Nuestro Padre Jesús de Murcia atesora una tumba de hierro única, impulsada por Francisco Peña Vaquero, un industrial propietario de una de las fundiciones más importantes de la Murcia en el cruce de los siglos XIX y XX, para el que el trabajo lo era todo. Sobre ese material se proyectaría un programa iconográfico que combina elementos tradicionales del mundo de la muerte con un repertorio centrado en los propios útiles de su actividad profesional. La suma de todo ello daría como resultado un catafalco desde el que se proclamaban los ideales de la resurrección cristiana a partir del esfuerzo laboral desarrollado durante la vida. Analizar estos aspectos y vincularlos con los aportes económicos y funerarios de su contexto nos dará las pautas para abordar el análisis de su significado.