6.1.2. Aqueous V(III) Chemistry 877 6.1.3. Oxidation State of Vanadium in Tunicates 878 6.1.4. Uptake of Vanadate into Tunicates 879 6.1.5. Vanadium Binding Proteins: Vanabins 879 6.1.6. Model Complexes and Their Chemistry 880 6.1.7. Catechol-Based Model Chemistry 880 6.1.8. Vanadium Sulfate Complexes 881 6.2. Fan Worm Pseudopotamilla occelata 883 7. Vanadium Nitrogenase 883 7.1. Nitrogenases 883 7.2. Biochemistry of Nitrogenase 884 7.3. Clusters in Nitrogenase and Model Systems: Structure and Reactivity 885

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The chemistry and biochemistry of vanadium and the biological activities exerted by vanadium compounds.

Starting with the history of the fundamental science of the relation of structure to composition delineated completely by Goldschmidt, we use the perovskite structure to illustrate the enormous pow...

The perovskite structure—a review of its role in ceramic science and technology

Calcium oxalate (CaOx) crystals are distributed among all taxonomic levels of photosynthetic organisms from small algae to angiosperms and giant gymnosperms. Accumulation of crystals by these organisms can be substantial. Major functions of CaOx crystal formation in plants include high-capacity calcium (Ca) regulation and protection against herbivory. Ultrastructural and developmental analyses have demonstrated that this biomineralization process is not a simple random physical-chemical precipitation of endogenously synthesized oxalic acid and environmentally derived Ca. Instead, crystals are formed in specific shapes and sizes. Genetic regulation of CaOx formation is indicated by constancy of crystal morphology within species, cell specialization, and the remarkable coordination of crystal growth and cell expansion. Using a variety of approaches, researchers have begun to unravel the exquisite control mechanisms exerted by cells specialized for CaOx formation that include the machinery for uptake and accumulation of Ca, oxalic acid biosynthetic pathways, and regulation of crystal growth.

CALCIUM OXALATE IN PLANTS: Formation and Function

I. Introduction A FUNCTIONAL relationship between cell growth and the initiation and progression of events associated with differentiation has been a fundamental question challenging developmental biologists for more than a century. In the case of bone, as observed with other cells and tissue, the relationship of growth and differentiation must be maintained and stringently regulated, both during development and throughout the life of the organism, to support tissue remodeling. For many years, bone was defined anatomically and examined largely in a descriptive manner by ultrastructural analysis and by biochemical and histochemical methods. These studies provided the basis for our understanding of bone tissue organization and orchestration of the progressive recruitment, proliferation, and differentiation of the various cellular components of bone tissue. Now, complemented by an increased knowledge of molecular mechanisms that are associated with and regulate expression of genes encoding phenotypic compone...

Molecular mechanism mediating proliferation, defferentiation interralationships during progressie development of the osteoblast phenotype

Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds.

/pdf/application-of-spectroscopic-methods-for-structural-analysis-82d20hw0o9.pdf

Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan

1 Departamento de Ingeniería Química, Facultad de Ingeniería, Universidad Nacional del Centro de la Provincia de Buenos Aires, 7400 Olavarría, Argentina. 2 Química Inorgánica, Departamento “Estrella Campos”, Facultad de Química, Universidad de la República, Montevideo, Uruguay. 3 Centro de Química Inorgánica (CEQUINOR, CONICET/UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C. Correo 962, 1900 La Plata, Argentina.

Vibrational spectra of Copper(II) complexes of L-Proline

The infrared spectrum of the Ag(NH2C6H4COO) complex was recorded and briefly discussed in relation to its structural characteristics. The solubility of the compound in water, at 20 °C, was determined by conductimetric measurements. For comparative purposes similar measurements were also performed with the Ag(I) complexes of saccharin and sulfadiazine. The results suggest that the anthranilate and saccharinate complexes may be useful as slow silver releasing systems in pharmaceutical formulations. RESUMEN. “Caracterizacion de antranilato de plata, un promisorio agente antibactericida”. Se registro el espectro de infrarrojo del complejo Ag(NH2C6H4COO) y se lo discutio brevemente en base a sus caracteristicas estructurales. La solubilidad del compuesto en agua, a 20 °C, se determino mediante medidas conductimetricas. Con fines comparativos se realizaron mediciones similares con los complejos que la Ag(I) forma con la sacarina y la sulfadiazina. Los resultados sugieren que los complejos de antranilato y de sacarinato podrian ser utiles como sistemas de liberacion lenta de plata en formulaciones farmaceuticas.

http://www.latamjpharm.org/trabajos/21/1/LAJOP_21_1_1_5_I577B660ER.pdf

Characterization of silver anthranilate, a promising antibacterial agent

Es wird eine neue Reihe tellurhaltiger Mischoxide der Zusammensetzung K3MIIITe3O12 (mit M = Al, Ga, Cr, Fe) beschrieben, welche in einer Uberstruktur des PbTiO3-Typs kristallisieren Die kristallographischen Daten der tetragonalen Elementarzellen wurden aus Pulverdiagrammen ermittelt Die IR-Spektren dieser Phasen sowie auch das 57Fe-Mosbauer-Spektrum von K3FeTe3O12 wurden aufgenommen und analysiert



Preparation and Properties of a New Series of Tellurium Containing Perovskites of the Type K3MIIITe3O12



A new series of tellurium containing mixed oxides of composition K3MIIITe3O12 (M = Al, Ga, Cr, Fe) has been described They crystallize in a superstructure-lattice of the PbTiO3 type The crystallographic data of the tetragonal unit cells have been determined from powder diffractograms The ir spectra of these phases as well as the 57Fe-Mossbauer-spectrum of K3FeTe3O12 were recorded and discussed

Enrique J. Baran

Papers

Vibrational spectra of Copper(II) complexes of L-Proline

Characterization of silver anthranilate, a promising antibacterial agent

Darstellung und Eigenschaften einer neuen Reihe tellurhaltiger Perovskite des typs K3MIIITe3O12

A spectrophotometric study of the interaction of VO2+ with cytosine in nucleotides.

Vibrational spectrum of Hg2ReO5