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Phosphates
Kinds of Phosphates Selected AbstractsPHOSPHATES IN ARCHAEOLOGICAL FINDS: IMPLICATIONS FOR ENVIRONMENTAL CONDITIONS OF BURIAL,ARCHAEOMETRY, Issue 4 2004L. MARITAN The occurrence of coarse-grained vivianite and mitridatite aggregates in a potsherd, a grand ring and a timber imprint from the Second Iron Age site of Adria (Rovigo, northeastern Italy) suggest contrasting environmental conditions of burial. In particular, bone fragments were replaced by vivianite at relatively low pH and Eh, due to the presence of deteriorating organic matter, together with slag and iron flakes. Subsequent interactions with Ca-rich groundwater characterized by higher pH and Eh determined the growth of mitridatite after vivianite. Although phosphates crystallized after burial, the examined samples were not involved in pervasive chemical contamination. [source] Structural Diversity in Organotin Compounds Derived from Bulky Monoaryl Phosphates: Dimeric, Tetrameric, and Polymeric Tin Phosphate ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2008Ramaswamy Murugavel Abstract Monoaryl phosphates with a bulky aryl substituent have been used to synthesize new organotin clusters and polymers. The equimolar reaction between 2,6-diisopropylphenylphosphate (dipp-H2) and Me2SnCl2 in ethanol at 25 °C leads to the formation of [Me2Sn(,3 -dipp)]n (1), while the reaction of 2,6-dimethylphenylphosphate (dmpp-H2) with Me2SnCl2 in either a 1:1 or 2:1 molar ratio proceeds to produce exclusively [Me2Sn(,-dmpp-H)2]n·nH2O (2). Compounds 1 and 2 are 1D polymers with different architectures. In compound 1, the tin atom is five-coordinate (trigonal bipyramidal). Each dipp ligand bridges three different tin atoms to form an infinite ladder-chain structure. In 2, each six-coordinate (octahedral) tin atom is surrounded by four phosphate oxygen atoms originating from four different bridging dmpp-H ligands, thus forming a spirocyclic coordination polymeric chain. The use of nBu2SnO as the diorganotin source in its reaction with dipp-H2 leads to the isolation of dimeric [nBu2Sn(,-dipp-H)(dipp-H)]2 (4), which contains a central Sn2O4P2 unit. There are two chemically different half molecules of 4 in the asymmetric part of the unit cell and hence it actually exists as a 1:1 mixture of [nBu2Sn(,-dipp-H)(dipp-H)]2 and [nBu2Sn(,-dipp)(dipp-H2)]2 in the solid state. The reaction of the monoorgano tin precursor nBuSn(O)(OH)·xH2O with dipp-H2 takes place in acetone at room temperature to yield the tetrameric cluster 5, which has different structures in the solution and in the solid state. 31P NMR spectroscopy clearly suggests that 5 has the formula [nBu4Sn4(,-O)2(,-dipp-H)8] in solution. The single-crystal X-ray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu4Sn4(,-OH)2(,-dipp-H)6(,-dipp)2]. The use of compounds 1,4 as possible precursors for the preparation of ceramic tin phosphate materials has been investigated. The thermolysis of 1 at 500 °C leads to the formation of quantitative amounts of Sn2P2O7, while the thermolysis of 2, 3, and 4 under similar conditions results in the formation of SnP2O7. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Amine-Intercalated Layered SnII Phosphates with Open-Framework StructuresEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2006Padmini Ramaswamy Abstract Three new SnII phosphate materials, [NH3(CH2)3NH2(CH2)2NH2(CH2)3NH3]·2[Sn2P2O8] (I), [(N2C5H14)2][Sn4P4O16]·3H2O (II) and [(N2C5H14)][Sn2P2O8]·H2O (III), have been synthesised by means of hydrothermal methods using N,N, -bis(3-aminopropyl)ethylenediamine (BAPEN; for I) and homopiperazine (H-PIP; for II and III), respectively, as the structure-directing organic amines. The solids I,III have layered architectures. The structures of all three compounds consist of strictly alternating vertex-sharing trigonal-pyramidal SnO3 and tetrahedral PO4 moieties forming infinite layers possessing apertures bound by 4- and 8-T atoms (T = Sn, P). The distorted 4- and 8-membered apertures within the layers suggest the subtle influence of the lone-pair of electrons of SnII on the structure. The interlamellar space is occupied by the protonated organic amine molecules which interact with the framework through N,H···O hydrogen bonding. The compounds I,III bear some structural relationship to the layered zinc phosphite phases. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Effects of Phosphates and Salt in Ground Raw and Cooked Farmed Cod (Gadus morhua) Muscle Studied by the Water Holding Capacity (WHC), and Supported by 31P-NMR MeasurementsJOURNAL OF FOOD SCIENCE, Issue 3 2009S.O. Johnsen ABSTRACT:, A model system consisting of ground farmed cod muscle (80%, w/w) and added brine (20%, w/w) with different content and combinations of salt (0% and 3% in brine) and phosphorus compounds (mono-, di-, tri- and hexametaphosphates; 0% and 3% in brine) was used to simulate industrial brining of muscle foods. Individual phosphorus component concentrations and breakdown as function of time (0, 23 h) were analyzed using 31P-NMR spectroscopy. The effects of salt and phosphate on water holding capacity (WHC) were measured at similar sampling times, and interrelations between phosphorous components determined by NMR and WHC were established. Addition of salt led to a significant increase (+18%) in WHC, and the combined effect of salt and phosphates was even more pronounced (+29%). The positive effect of triphosphate and salt on WHC was also seen after cooking (+36% in raw and +41% in cooked cod muscle, relative to control), although NMR analysis showed a rapid breakdown of di- and triphosphates. [source] Properties, Translucence, and Microstructure of Pacific White Shrimp Treated with Mixed Phosphates as Affected by Freshness and DeveiningJOURNAL OF FOOD SCIENCE, Issue 1 2008N. Rattanasatheirn ABSTRACT:, Effects of freshness and deveining on some properties, translucence, and microstructure of Pacific white shrimp (Litopenaeus vannamei) soaked in 2.5% NaCl containing different phosphates were studied. Shrimp soaked in all solutions had increases in weight gain and cooking yield with lowered cooking loss, compared with the control (P < 0.05). However, efficacy of mixed phosphates in quality improvement of ice-stored shrimp was lower than fresh shrimp. Deveining resulted in increased weight gain and yield (P < 0.05). Nevertheless, samples treated with phosphates became more translucent. Shrimp stored in ice for 7 d and treated with mixed phosphates were generally more translucent than fresh counterparts (P < 0.05). Shrimp soaked in 2.5% NaCl containing 0.875% sodium acid pyrophosphate (SAPP) and 2.625% tetrasodium pyrophosphate (TSPP) were generally less translucent and had high weight gain and cooking yield along with low cooking loss. The microstructure study revealed that the muscle fibers were less attached with the loss of Z-disks after being treated with mixed phosphates. Cooked meats of fresh shrimp and ice-stored shrimp had more compact fiber arrangement with the shrinkage of sarcomere compared with raw samples. Disintegration was observed at the M-line in ice-stored shrimp treated with mixed phosphates after cooking, while such a phenomenon was not found in the cooked fresh sample treated with phosphates. Tmax and enthalpy of both myosin and actin peaks shifted to lower values when shrimp were treated with mixed phosphates (P < 0.05). Those changes were generally more pronounced in ice-stored shrimp. Therefore, freshness and deveining process had an impact on the quality of Pacific white shrimp treated with phosphates. [source] Evaluation of Garam Masala Spices and Phosphates as Antioxidants in Cooked Ground BeefJOURNAL OF FOOD SCIENCE, Issue 5 2006Mihir N. Vasavada ABSTRACT:, This study determined antioxidant effects and sensory attributes of individual ingredients (black pepper, caraway, cardamom, chili powder, cinnamon, cloves, coriander, cumin, fennel, ginger, nutmeg, salt, star anise) of an Indian spice blend (garam masala) in cooked ground beef. Thiobarbituric acid (TBA) values were measured as an indicator of rancidity for cooked samples on 1-, 8-, or 15-d refrigerated storage. Cooked samples were evaluated by a trained panel (n= 13) for the intensity of rancid odor/flavor, beef flavor, and spice flavor and correlated with TBA values of same day samples. We also investigated possible additive effects between spice antioxidants and iron binding (type II) antioxidants on lipid oxidation by measuring TBA values. All spices had antioxidant effects on cooked ground beef, compared to controls. Among spices, cloves were the most effective in controlling lipid oxidation, with TBA values of 0.75, after 15-d refrigerated storage. All spices at their recommended levels lowered rancid odor and flavor in cooked ground beef, compared to controls. As expected, most spices also imparted distinctive flavors to cooked ground beef. There was a positive correlation (0.77) between TBA values on 15-d refrigerated storage and rancid odor/flavor. Type II antioxidants (iron-binding phosphate compounds) were more effective than individual type I antioxidants (spices and butylated hydroxytoluene; BHT) for maintenance of low TBA values in cooked ground beef during storage. Additive effects were observed with rosemary + milk mineral or sodium tripolyphosphate (STP) compared to rosemary alone. [source] Coupling of Canine Serotonin 5-HT1B and 5-HT1D Receptor Subtypes to the Formation of Inositol Phosphates by Dual Interactions with Endogenous Gi/o and Recombinant G,15 ProteinsJOURNAL OF NEUROCHEMISTRY, Issue 3 2000Thierry Wurch Abstract: Molecular cloning and expression of canine (ca) serotonin 5-HT1B and ca 5-HT1D receptor subtypes showed that besides the lower binding affinity of ketanserin for the ca 5-HT1D receptor, the ligand binding profiles were similar to their human homologues. Site-directed mutagenesis studies suggest that a Gln189 residue in the second extracellular loop of the ca 5-HT1D receptor may partially account for the lower binding affinity of ketanserin. The coupling of ca 5-HT1B and ca 5-HT1D receptor subtypes to the phospholipase C pathway was analyzed by measuring stimulation of inositol phosphate formation in COS-7 cells. Zolmitriptan potently stimulated (EC50 = 4.9 nM) the inositol phosphate formation at ca 5-HT1D receptors in a fully pertussis toxin (PTX)-dependent manner, whereas only a weak PTX-resistant inositol phosphate response (26-29% at 10 ,M zolmitriptan) could be detected for the ca 5-HT1B receptor at a similar expression level. In contrast, both ca 5-HT1B and ca 5-HT1D receptor subtypes yielded a similar maximal magnitude of inositol phosphate formation (300-340% at 10 ,M zolmitriptan) upon co-expression with a mouse (m) G,15 protein. PTX treatment and co-expression with a ,-adrenergic receptor kinase C-terminal polypeptide partially (20-46%) abolished the m G,15 protein-dependent ca 5-HT1B and ca 5-HT1D receptor-mediated stimulation of inositol phosphate formation. This study suggests both 5-HT receptor subtypes can activate ,, subunits of endogenous Gi/o proteins besides their coupling to recombinant m G,15 protein. [source] Metathetic Reaction in Reverse Micelles: Synthesis of Nanostructured Alkaline-Earth Metal PhosphatesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2007Purnendu Parhi For the past few years, hydroxyapatite (HAp) has been identified as a potential biomaterial due to its excellent biocompatibility and bioactivity. The preparation of nanostructured HAp with controlled powder characteristics is a pre-requisite for processing it into useful biocomposites. Here, the synthesis of nanorods of calcium hydroxyapatite (Ca-HAp), strontium hydroxyapatite (Sr-HAp), and barium hydroxyapatite (Ba-HAp) by exploiting the metathetic reaction taking place in reverse micelles in the presence of cetyltrimethylammonium bromide has been reported. Powder X-ray diffraction analysis and thermogravimetric measurements confirm the formation of monophasic Ca-HAp and Sr-HAp. The growth of nanorods was further confirmed using transmission electron microscopy studies. The average lengths of Ca-HAp and Sr-HAp were ,60 and 30 nm, respectively. However, the preparation of Ba-HAp invariably yielded a multiphasic mixture with other competitive phases like BaHPO4 and Ba(H2PO4)2. [source] Gold(I)-Catalyzed Addition of Diphenyl Phosphate to Alkynes: Isomerization of Kinetic Enol Phosphates to the Thermodynamically Favored Isomers,ANGEWANDTE CHEMIE, Issue 38 2010Prof. Gold, Gold oder , Gold? Der Gold- Katalysator bestimmt, ob bei der im Schema gezeigten Hydrophosphoryloxylierung das Produkt der thermodynamischen oder der kinetischen Steuerung entsteht. Ein dritter Katalysator, [(C6F5)3PAuOTf], erwies sich als enorm effektiv in der bislang unbekannten Isomerisierung kinetischer Enolphosphate in die thermodynamisch begünstigten Isomere. Tf=Trifluormethansulfonyl; R=Alkyl, Cyclohexyl, Ph. [source] Layered Zinc Phosphates with Photoluminescence and Photochromism: Chemistry in Deep Eutectic Solvents,ANGEWANDTE CHEMIE, Issue 25 2010Pei-Ci Jhang Ein orangefarbenes Leuchtmaterial ohne Metallaktivator wurde aus ZnO/H3PO3/Diamin in Cholinchlorid/Oxalsäure als Lösungsmittel mit tiefem Eutektikum synthetisiert, das zugleich , durch Dissoziation der Cholin-Ionen , als Methylierungsmittel und Quelle von Ethylenglycol (EG) wirkte. Die Einlagerung von dimethylierten Ammoniumionen ergab photochromes schichtförmiges Zinkphosphat (,ZnPO", siehe Bild), und ihre Wechselwirkung mit EG führte zu Fluorophoren mit orangefarbener Photolumineszenz. [source] Promotion and contribution of biota in low water exchange ponds farming blue shrimp Litopenaeus stylirostris (Stimpson)AQUACULTURE RESEARCH, Issue 1 2002Luis R Martinez-Cordova Abstract An experimental study was conducted during 20 weeks in Bahia Kino, Sonora, Mexico, in order to evaluate the feasibility of promoting biota in low-water exchange ponds farming blue shrimp, Litopenaeus stylirostris. The effect of that promotion on the production parameters of cultured shrimp as well as on the water quality parameters was evaluated. Treatments consisted of: (i) ponds fed formulated food (FF), and (ii) ponds fed formulated plus promoted natural food (NFF). Phytoplankton, zooplankton and benthos were effectively promoted during some weeks of the culture period. Growth and feed conversion ratio (15.16 g and 1.79 respectively) were significantly better in treatment NFF than in treatment FF (13.89 g and 2.02 respectively). Differences in some of the water quality parameters were observed among treatments. Phosphates (0.15 mg/L versus 0.53 mg/L), and total ammonia-N (0.09 mg/L versus 0.12 mg/L) presented greater concentrations in treatment FF than in the NFF. [source] Reaction of Cytidine Nucleotides with Cyanoacetylene: Support for the Intermediacy of Nucleoside-2,,3,-cyclic Phosphates in the Prebiotic Synthesis of RNACHEMBIOCHEM, Issue 6 2006Michael A. Crowe Abstract A robust and prebiotically plausible synthesis of RNA is a key requirement of the "RNA World" hypothesis, but, to date, no such synthesis has been demonstrated. Monomer synthesis strategies involving attachment of preformed nucleobases to sugars have failed, and, even if activated 5,-nucleotides could be made, the hydrolysis of these intermediates in water makes their efficient oligomerisation appear unlikely. We recently reported a synthesis of cytidine-2,,3,-cyclic phosphate 1 (C>p) in which the nucleobase was assembled in stages on a sugar-phosphate template. However, 2,,3,-cyclic nucleotides (N>p's) also undergo hydrolysis, in this case giving a mixture of the 2,- and 3,-monophosphates. This hydrolysis has previously been seen as making the, otherwise promising, oligomerisation of N>p's seem as unlikely as that of the 5,-activated nucleotides. We now find that cyanoacetylene, the reagent used for the second stage of nucleobase assembly in the synthesis of C>p, also reverses the effect of the hydrolysis by driving efficient cyclisation of C2,p and C3,p back to C>p. Excess cyanoacetylene also derivatises the nucleobase, but this modification is reversible at neutral pH. These findings significantly strengthen the case for N>p's in a prebiotic synthesis of RNA. [source] ChemInform Abstract: Copper-Catalyzed ,-Selective Allyl,Alkyl Coupling Between Allylic Phosphates and Alkylboranes.CHEMINFORM, Issue 31 2010Hirohisa Ohmiya Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Palladium-Catalyzed Direct Arylations, Alkenylations, and Benzylations Through C,H Bond Cleavages with Sulfamates or Phosphates as Electrophiles.CHEMINFORM, Issue 27 2010Lutz Ackermann Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Syntheses, Crystal and Electronic Structures of Two New Lead Indium Phosphates: Pb2In4P6O23 and Pb2InP3O11.CHEMINFORM, Issue 6 2010Wei-Long Zhang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Aminocarbonylations of Alkenyl Phosphates, Chlorides, Bromides, and Triflates with Mo(CO)6 as a Solid CO Source.CHEMINFORM, Issue 1 2010Olof Lagerlund Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Channels Occupancy and Distortion in New Lithium Uranyl Phosphates with Three-Dimensional Open-Frameworks.CHEMINFORM, Issue 36 2009C. Renard Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: An Efficient and Highly Selective Synthesis of (Z)-Fluoroenol Phosphates from Hydroxy Difluorophosphonates.CHEMINFORM, Issue 32 2009Petr Beier Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Total Synthesis of Isoindolobenzazepine Alkaloids, Lennoxamine (XV) and Chilenine (XVI), Based on Palladium-Catalyzed Reduction of Alkenyl Phosphates.CHEMINFORM, Issue 11 2009Haruhiko Fuwa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Crystal Chemistry and Thermal Behavior of Anhydrous Phosphates.CHEMINFORM, Issue 9 2009Part 42. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Iron-Catalyzed Alkenylation of Grignard Reagents by Enol Phosphates.CHEMINFORM, Issue 1 2009Gerard Cahiez Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Syntheses and Crystal Structures of Two New Open-Framework Tin(II) Phosphates: Sn5O2(PO4)2 and Sn4O(PO4)2.CHEMINFORM, Issue 16 2008Le-Qing Fan Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Structural Characterizations and Magnetic Properties of Three New Reduced Molybdenum Phosphates.CHEMINFORM, Issue 6 2008Xiao Zhang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Synthesis and Crystal Structure of Three Silver Indium Double Phosphates.CHEMINFORM, Issue 10 2007M. A. Strelkov Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of Functionalized Diarylmethanes via a Copper-Catalyzed Cross-Coupling of Arylmagnesium Reagents with Benzylic Phosphates.CHEMINFORM, Issue 2 2007Christiane C. Kofink Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Amine-Intercalated Layered SnII Phosphates with Open-Framework Structures.CHEMINFORM, Issue 47 2006Padmini Ramaswamy Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Heck Coupling with Nonactivated Alkenyl Tosylates and Phosphates: Examples of Effective 1,2-Migrations of the Alkenyl Palladium(II) Intermediates.CHEMINFORM, Issue 37 2006Anders L. Hansen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Natural Phosphate and Potassium Fluoride Doped Natural Phosphates as New Catalysts for the Vilsmeier,Haack Type Reaction.CHEMINFORM, Issue 24 2006Mohamed Zahouily Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Formation of New Phosphates from Aldehydes by a DBU-Catalyzed Phospha-Brook Rearrangement in a Polar Solvent.CHEMINFORM, Issue 5 2006Laurent El Kaim No abstract is available for this article. [source] Syntheses, Structures, and Ion-Exchange Properties of the Three-Dimensional Framework Uranyl Gallium Phosphates, Cs4 [(UO2)2(GaOH)2(PO4)4] ×H2O and Cs[UO2Ga(PO4)2].CHEMINFORM, Issue 13 2005Tatiana Y. Shvareva Abstract For Abstract see ChemInform Abstract in Full Text. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||