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Sample records for alkyl phosphonic acid

  1. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  2. A plausibly prebiotic synthesis of phosphonic acids.

    PubMed

    de Graaf, R M; Visscher, J; Schwartz, A W

    1995-11-30

    The insolubility of calcium phosphate in water is a significant stumbling block in the chemistry required for the origin of life. The discovery of alkyl phosphonic acids in the Murchison meteorite suggests the possibility of delivery of these water-soluble, phosphorus-containing molecules by meteorites or comets to the early Earth. This could have provided a supply of organic phosphorus for the earliest stages of chemical evolution; although probably not components of early genetic systems, phosphonic acids may have been precursors to the first nucleic acids. Here we report the synthesis of several phosphonic acids, including the most abundant found in the Murchison meteorite, by ultraviolet irradiation of orthophosphorous acid in the presence of formaldehyde, primary alcohols, or acetone. We argue that similar reactions might explain the presence of phosphonic acids in Murchison, and could also have occurred on the prebiotic Earth.

  3. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  4. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  5. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  6. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  7. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  8. 40 CFR 721.10677 - Alkyl phosphonate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10677 Alkyl phosphonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl phosphonate (PMN...

  9. Isopropyl methyl phosphonic acid (IMPA)

    Integrated Risk Information System (IRIS)

    Isopropyl methyl phosphonic acid ( IMPA ) ; CASRN 1832 - 54 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

  10. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  11. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  12. Hydrophosphorylation of substituted alkynes by phosphonic acids

    SciTech Connect

    Nifant'ev, E.F.; Solovetskaya, L.A.; Maslennikova, V.I.; Sergeev, N.M.

    1987-08-20

    Hydrophosphorylation of functionally substituted alkynes by phosphonic acids can be a convenient method for synthesis of functionally substituted mono- and diphosphine oxides. The ease of hydrophosphorylation is determined by the strength of the negative inductive effect of the substituents on the triple bond and the steric factor. The structure of the bis-adducts was confirmed by elementary analysis and the /sup 31/P and /sup 13/C NMR spectra. The /sup 31/P NMR spectrum is an AB two-spin system. The values of the chemical shifts and spin-spin interaction constants /sup 3/J/sub PP/ are in agreement with the data in the literature for similar compounds.

  13. Developmental Toxicity of Perfluorinated Phosphonic Acids in Mice

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a third member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. PFPAs are used primarily as a surfactant defoaming agent in pesticide production. Re...

  14. Fluorescent carboxylic and phosphonic acids: comparative photophysics from solution to organic nanoparticles.

    PubMed

    Faucon, Adrien; Lenk, Romaric; Hémez, Julie; Gautron, Eric; Jacquemin, Denis; Le Questel, Jean-Yves; Graton, Jérôme; Brosseau, Arnaud; Ishow, Eléna

    2013-08-14

    Phosphonic and carboxylic fluorescent nanoparticles have been fabricated by direct reprecipitation in water. Their fluorescence properties strongly differ from those of the corresponding esters where strong H-bonding formation is prohibited. Comparative experiments between the two acid derivatives, differing only in their acid functions while keeping the same alkyl chain, have evidenced the peculiar behavior of the phosphonic acid derivative compared to its carboxylic analog. A dramatic emission quenching for the phosphonic acid in aprotic toluene could be observed while a fivefold increase in the fluorescence signal was observed for molecules assembled as nanoparticles. Such properties have been attributed on the theoretical basis to the formation of folded conformers in solution, leading to deactivation of the radiative excited state through intramolecular H-bonding. These studies evidence for the first time through time-resolved fluorescence measurements the stronger H-donating character of phosphonic acids compared to the carboxylic ones, and provide information on the degree of structural heterogeneity within the nanoparticles. They should pave the way for the rational fabrication of chelating acid fluorophores, able to complex metal oxides to yield stiff hybrid magnetofluorescent nanoparticles which are attracting considerable attention in the growing fields of bimodal imaging and vectorization applications.

  15. Characterizing mixed phosphonic acid ligand capping on CdSe/ZnS quantum dots using ligand exchange and NMR spectroscopy.

    PubMed

    Davidowski, Stephen K; Lisowski, Carmen E; Yarger, Jeffery L

    2016-03-01

    The ligand capping of phosphonic acid functionalized CdSe/ZnS core-shell quantum dots (QDs) was investigated with a combination of solution and solid-state (31) P nuclear magnetic resonance (NMR) spectroscopy. Two phosphonic acid ligands were used in the synthesis of the QDs, tetradecylphosphonic acid and ethylphosphonic acid. Both alkyl phosphonic acids showed broad liquid and solid-state (31) P NMR resonances for the bound ligands, indicative of heterogeneous binding to the QD surface. In order to quantify the two ligand populations on the surface, ligand exchange facilitated by phenylphosphonic acid resulted in the displacement of the ethylphosphonic acid and tetradecylphosphonic acid and allowed for quantification of the free ligands using (31) P liquid-state NMR. After washing away the free ligand, two broad resonances were observed in the liquids' (31) P NMR corresponding to the alkyl and aromatic phosphonic acids. The washed samples were analyzed via solid-state (31) P NMR, which confirmed the ligand populations on the surface following the ligand exchange process. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Reaction of perfluoroalkyl grignard reagents with phosphorus trihalides: a new route to perfluoroalkyl-phosphonous and -phosphonic acids.

    PubMed

    Hosein, Adil I; Le Goff, Xavier F; Ricard, Louis; Caffyn, Andrew J M

    2011-02-21

    The reaction of perfluoroalkyl Grignard reagents with phosphorus(III) halides was explored. In the process a new convenient, one-pot, high yield method for the synthesis of (perfluoroalkyl)phosphonic acids has been developed. Perfluoroalkyl Grignard reagents react with phosphorus trichloride or phosphorus tribromide to form (perfluoroalkyl)phosphonous dihalides. Hydrolysis gives the corresponding (perfluoroalkyl)phosphonous acids. Oxidation of the phosphonous acids with H(2)O(2) produces (perfluoroalkyl)phosphonic acids in 60-78% overall yields, based on the corresponding perfluoroalkyl iodide. The X-ray crystal structures of the toluidinium salts, [MeC(6)H(4)NH(3)](2)[C(2)F(5)PO(3)] and [MeC(6)H(4)NH(3)][C(8)F(17)P(O)(2)OH], are reported.

  17. 40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid ester (generic) (P-07... Specific Chemical Substances § 721.10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance... phosphonic acid ester (PMN P-07-706) is subject to reporting under this section for the significant new...

  18. 40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid ester (generic) (P-07... Specific Chemical Substances § 721.10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance... phosphonic acid ester (PMN P-07-706) is subject to reporting under this section for the significant new...

  19. 40 CFR 721.10412 - Phosphonic acid ester (generic) (P-07-706).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid ester (generic) (P-07... Specific Chemical Substances § 721.10412 Phosphonic acid ester (generic) (P-07-706). (a) Chemical substance... phosphonic acid ester (PMN P-07-706) is subject to reporting under this section for the significant new...

  20. Asymmetric Friedel-Crafts alkylations of indoles with dialkyl 3-oxoprop-1-enylphosphonates: organocatalytic enantioselective synthesis of alpha-indolyl phosphonates.

    PubMed

    Guo, Ying-Cen; Li, Dong-Ping; Li, Yu-Ling; Wang, Hong-Mei; Xiao, Wen-Jing

    2009-08-01

    Organocatalytic enantioselective synthesis of alpha-indolyl phosphonates has been successfully carried out via asymmetric Friedel-Crafts alkylation of substituted indoles with (E)-dialkyl 3-oxoprop-1-enylphosphonates in 48-82% yield and 73-96% ee.

  1. Synthesis and characterization of phosphonate ester and phosphonic acid containing polymers and blends

    NASA Astrophysics Data System (ADS)

    Tamber, Harinder Singh

    1997-12-01

    Vinylbenzylphosphonate ester (VBP) was homopolymerized and copolymerized with methyl methacrylate and the reactivity ratio of this pair of monomers was calculated from Finneman-Ross and Kelen-Tudos methods. These methods provided identical values, which are rsb1 (VBP) = 1.23 and rsb2(MMA) = 0.43. The phosphonate ester group, -P = O(OEt)sb2; in VBP and poly(VBP-MMA) copolymers was hydrolysed to phosphonic acid, -P = O(OH)sb2; at room temperature to obtain vinylbenzylphosphonic acid (VBPa) and poly(VBPa-MMA) copolymers. sp1H, sp{13}C & sp{31}P NMR spectroscopy, DSC and FTIR were used to monitor the hydrolysis of these phosphorylated monomers and polymers. The glass transition temperature of PVBP was 13sp°C as compared to 198sp°C of PVBPa. The phosphoryl group in the parent polymers acts as a self plasticizing agent resulting in lower glass transition temperature, on the other hand inter and intra hydrogen bonding results in broad and high Tsbg in these hydrolysed polymers. VBP was also polymerized with BisGMA or TEGDM to low conversions. These oligomers were tested in vitro as potential adhesive materials for dental/enamel and composite resins. The phosphonate esters containing polymers show substantial capacity to dissolve the heavy metal salts, e.g., UOsb2(NO)sb3.6Hsb2O and thus provides radiopaque polymers. Excessive sorption of water lead to phase separation and, hence, loss of radiopacity. Thus, an alternate method of synthesis of radiopaque polymers is also described in which radiopacifying agent is covalently linked to polymer backbone. Styryldiphenylbismuth was prepared by the reaction of diphenylbismuthchloride and Grignard of p-bromostyrene, but some other by-products such as triphenylbismuth, distyrylphenyl bismoth were also obtained as revealed by reverse phase HPLC and the yield of the reaction was low. Iodinated monomers VBTIsb3 and IEMIsb3 were prepared by reacting VBC or IEM to triiodophenol in high yields. Decomposition kinetic analysis was done by

  2. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  3. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  4. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  5. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  6. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  7. Phosphonic Acid-Functionalized Polyurethane Dispersions with Improved Adhesion Properties.

    PubMed

    Breucker, Laura; Landfester, Katharina; Taden, Andreas

    2015-11-11

    A facile route to phosphorus-functionalized polyurethane dispersions (P-PUDs) with improved adhesion properties is presented. (Bis)phosphonic acid moieties serve as adhesion promoting sites that are covalently attached via an end-capping reaction to isocyanate-reactive polyurethane particles under aqueous conditions. The synthetic approach circumvents solubility issues, offers great flexibility in terms of polyurethane composition, and allows for the synthesis of semicrystalline systems with thermomechanical response due to reversible physical cross-linking. Differential scanning calorimetry (DSC) is used to investigate the effect of functionalization on the semicrystallinity. The end-capping conversion was determined via inductively-coupled plasma optical emission spectroscopy (ICP-OES) and was surprisingly found to be almost independent of the stoichiometry of reaction, suggesting an adsorption-dominated process. Particle charge detection (PCD) experiments reveal that a dense surface coverage of phosphonic acid groups can be attained and that, at high functionalization degrees, the phosphonic adhesion moieties are partially dragged inside the colloidal P-PUD particle. Quartz crystal microbalance with dissipation (QCMD) investigations conducted with hydroxyapatite (HAP) and stainless steel sensors as model surfaces show a greatly enhanced affinity of the aqueous P-PUDs and furthermore indicate polymer chain rearrangements and autonomous film formation under wet conditions. Due to their facile synthesis, significantly improved adhesion, and variable film properties, P-PUD systems such as the one described here are believed to be of great interest for multiple applications, e.g., adhesives, paints, anticorrosion, or dentistry.

  8. 40 CFR 721.10370 - Phosphonic acid, p-octyl-, lanthanum (3+) salt (2:1).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, p-octyl-, lanthanum... New Uses for Specific Chemical Substances § 721.10370 Phosphonic acid, p-octyl-, lanthanum (3+) salt... substance identified as phosphinic acid, p-octyl-, lanthanum (3+) salt (2:1) (PMN P-10-99; CAS No....

  9. 40 CFR 721.10370 - Phosphonic acid, p-octyl-, lanthanum (3+) salt (2:1).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, p-octyl-, lanthanum... New Uses for Specific Chemical Substances § 721.10370 Phosphonic acid, p-octyl-, lanthanum (3+) salt... substance identified as phosphinic acid, p-octyl-, lanthanum (3+) salt (2:1) (PMN P-10-99; CAS No....

  10. 40 CFR 721.10370 - Phosphonic acid, p-octyl-, lanthanum (3+) salt (2:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, p-octyl-, lanthanum... New Uses for Specific Chemical Substances § 721.10370 Phosphonic acid, p-octyl-, lanthanum (3+) salt... substance identified as phosphinic acid, p-octyl-, lanthanum (3+) salt (2:1) (PMN P-10-99; CAS No....

  11. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1996-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  12. Phosphonic acid based ion exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1994-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene disphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  13. Phosphonic Acid Functionalized Asymmetric Phthalocyanines: Synthesis, Modification of Indium Tin Oxide (ITO), and Charge Transfer

    SciTech Connect

    Polaske, Nathan W.; Lin, Hsiao-Chu; Tang, Anna; Mayukh, Mayank; Oquendo, Luis E.; Green, John; Ratcliff, Erin L.; Armstrong, Neal R.; Saavedra, S. Scott; McGrath, Dominic V.

    2011-12-20

    Metalated and free-base A₃B-type asymmetric phthalocyanines (Pcs) bearing, in the asymmetric quadrant, a flexible alkyl linker of varying chain lengths terminating in a phosphonic acid (PA) group have been synthesized. Two parallel series of asymmetric Pc derivatives bearing aryloxy and arylthio substituents are reported, and their synthesis and characterization through NMR, combustion analysis, and MALDI-MS are described. We also demonstrate the modification of indium tin oxide (ITO) substrates using the PA functionalized asymmetric Pc derivatives and monitoring their electrochemistry. The PA functionalized asymmetric Pcs were anchored to the ITO surface through chemisorption and their electrochemical properties characterized using cyclic voltammetry to investigate the effects of PA structure on the thermodynamics and kinetics of charge transfer. Ionization energies of the modified ITO surfaces were measured using ultraviolet photoemission spectroscopy.

  14. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  15. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  16. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  17. Kinetic resolution of racemic carboxylic acids through asymmetric protolactonization promoted by chiral phosphonous acid diester.

    PubMed

    Sakuma, Masayuki; Sakakura, Akira; Ishihara, Kazuaki

    2013-06-07

    Chiral phosphonium salts induce the kinetic resolution of racemic α-substituted unsaturated carboxylic acids through asymmetric protolactonization. Both the lactones and the recovered carboxylic acids are obtained with high enantioselectivities and high S (= kfast/kslow) values. Asymmetric protolactonization also leads to the desymmetrization of achiral carboxylic acids. Notably, chiral phosphonous acid diester not only induced the enantioselectivity but also promoted protolactonization.

  18. Effects of Perfluorinated Phosphonic Acid Exposure during pregnancy in the mouse

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. These chemicals have recently been detected in the environment, particularly in surface wa...

  19. Preliminary assessment of developmental toxicity of Perfluorinated Phosphonic Acid in mice

    EPA Science Inventory

    Perfluorinated phosphonic acids (PFPAs) are a third member of the perfluoroalkyl acid (PFAA) family, and are structurally similar to the perfluoroalkyl sulfonates and perfluoroalkyl carboxylates. These emerging chemicals have recently been detected in the environment, particularl...

  20. Graphene phosphonic acid as an efficient flame retardant.

    PubMed

    Kim, Min-Jung; Jeon, In-Yup; Seo, Jeong-Min; Dai, Liming; Baek, Jong-Beom

    2014-03-25

    We report the preparation of graphene phosphonic acid (GPA) via a simple and versatile method and its use as an efficient flame retardant. In order to covalently attach phosphorus to the edges of graphene nanoplatelets, graphite was ball-milled with red phosphorus. The cleavage of graphitic C-C bonds during mechanochemical ball-milling generates reactive carbon species, which react with phosphorus in a sealed ball-mill crusher to form graphene phosphorus. Subsequent opening of the crusher in air moisture leads to violent oxidation of graphene phosphorus into GPA (highest oxidation state). The GPA is readily dispersible in many polar solvents, including neutral water, allowing for solution (spray) coating for high-performance, nontoxic flame-retardant applications.

  1. Bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism.

    PubMed Central

    Wackett, L P; Shames, S L; Venditti, C P; Walsh, C T

    1987-01-01

    Carbon-phosphorus bond cleavage activity, found in bacteria that utilize alkyl- and phenylphosphonic acids, has not yet been obtained in a cell-free system. Given this constraint, a systematic examination of in vivo C-P lyase activity has been conducted to develop insight into the C-P cleavage reaction. Six bacterial strains were obtained by enrichment culture, identified, and characterized with respect to their phosphonic acid substrate specificity. One isolate, Agrobacterium radiobacter, was shown to cleave the carbon-phosphorus bond of a wide range of substrates, including fosfomycin, glyphosate, and dialkyl phosphinic acids. Furthermore, this organism processed vinyl-, propenyl-, and propynylphosphonic acids, a previously uninvestigated group, to ethylene, propene, and propyne, respectively. A determination of product stoichiometries revealed that both C-P bonds of dimethylphosphinic acid are cleaved quantitatively to methane and, furthermore, that the extent of C-P bond cleavage correlated linearly with the specific growth rate for a range of substrates. The broad substrate specificity of Agrobacterium C-P lyase and the comprehensive characterization of the in vivo activity make this an attractive system for further biochemical and mechanistic experiments. In addition, the failure to observe the activity in a group of gram-positive bacteria holds open the possibility that a periplasmic component may be required for in vivo expression of C-P lyase activity. PMID:3804975

  2. Determination of perfluoroalkyl carboxylic, sulfonic, and phosphonic acids in food.

    PubMed

    Ullah, Shahid; Alsberg, Tomas; Vestergren, Robin; Berger, Urs

    2012-11-01

    A sensitive and accurate method was developed and validated for simultaneous analysis of perfluoroalkyl carboxylic acids, sulfonic acids, and phosphonic acids (PFPAs) at low picograms per gram concentrations in a variety of food matrices. The method employed extraction with acetonitrile/water and cleanup on a mixed-mode co-polymeric sorbent (C8 + quaternary amine) using solid-phase extraction. High-performance liquid chromatographic separation was achieved on a C18 column using a mobile phase gradient containing 5 mM 1-methyl piperidine for optimal chromatographic resolution of PFPAs. A quadrupole time-of-flight high-resolution mass spectrometer operating in negative ion mode was used as detector. Method detection limits were in the range of 0.002 to 0.02 ng g(-1) for all analytes. Sample preparation (extraction and cleanup) recoveries at a spiking level of 0.1 ng g(-1) to a baby food composite were in the range of 59 to 98 %. A strong matrix effect was observed in the analysis of PFPAs in food extracts, which was tentatively assigned to sorption of PFPAs to the injection vial in the solvent-based calibration standard. The method was successfully applied to a range of different food matrices including duplicate diet samples, vegetables, meat, and fish samples.

  3. Nanocomposites of phosphonic-acid-functionalized polyethylenes with inorganic quantum dots.

    PubMed

    Rünzi, Thomas; Baier, Moritz C; Negele, Carla; Krumova, Marina; Mecking, Stefan

    2015-01-01

    Insertion of diethyl vinyl phosphonates and free vinyl phosphonic acid, respectively, into [(P^O)Pd(Me)(dmso)] ((P^O) = κ(2)-P,O-Ar2PC6H4SO2O with Ar = 2-MeOC6H4) (1-dmso) occurs in a 2,1- as well as 1,2-fashion, to form a four-and a five-membered chelate [(P^O)Pd{κ(2)-C,O-CH(P(O)(OR)2)CH2CH3}] and [(P^O)Pd{κ(2)-C,O-CH2CH(P(O)(OR)2)CH3}] (R = H, Et). No decomposition or other reactions of 1 by free phosphonic acid moieties occur. Copolymerization in a pressure reactor by 1-dmso yields linear random poly(ethylene-co-diethyl vinyl phosphonate) and poly(ethylene-co-vinyl phosphonic acid). In these copolymerizations, reversible coordination of the phosphonate moieties of free monomer as well as chelate formation by incorporated monomer retards chain growth as also evidenced by relative binding studies of diethyl phosphonate towards 1. Post-polymerization emulsification of poly(ethylene-co-vinyl phosphonic acid) together with CdSe/CdS quantum dots (QDs) yields submicron (ca. 50 nm from dynamic light scattering (DLS) and transmission electron microscopy (TEM)) polymer particles with the QDs embedded in the functionalized polyethylene in a nonaggregated fashion. This embedding benefits the fluorescence behavior in terms of continuous emission and life-time as revealed by wide-field fluorescence measurements. These composite particle dispersions are employed as a ″masterbatch" together with an aqueous high density polyethylene (HDPE) dispersion to generate thin films (by spin-coating) and bulk materials (from the melt), respectively, in which the inorganic nanoparticles remain highly disperse.

  4. Iron-Catalyzed Decarboxylative Alkyl Etherification of Vinylarenes with Aliphatic Acids as the Alkyl Source.

    PubMed

    Jian, Wujun; Ge, Liang; Jiao, Yihang; Qian, Bo; Bao, Hongli

    2017-03-20

    Because of the lack of effective alkylating reagents, alkyl etherification of olefins with general alkyl groups has not been previously reported. In this work, a variety of alkyl diacyl peroxides and peresters generated from aliphatic acids have been found to enable the first iron-catalyzed alkyl etherification of olefins with general alkyl groups. Primary, secondary and tertiary aliphatic acids are suitable for this reaction, delivering products with yields up to 97 %. Primary and secondary alcohols react well, affording products in up to 91 % yield.

  5. Layered Calcium Structures of p-Phosphonic Acid O-Methyl-Calix[6]arene

    PubMed Central

    Clark, Thomas E.; Martin, Adam; Makha, Mohamed; Sobolev, Alexandre N.; Su, Dian; Rohrs, Henry W.; Gross, Michael L.; Raston, Colin L.

    2010-01-01

    Hexamethoxy-calix[6]arene has been fully functionalized with p-phosphonic acid groups on the upper rim in 57% yield over three steps, and has been authenticated in the solid state by X-ray diffraction as either a nitrate salt or one of two calcium complexes. The latter differ by the ratio of calcium ions per calixarene, either 3:1 or 4:1. In both structures the coordination sphere of the calcium ions is made up of oxygen atoms from the phosphonic acid groups and from water of crystallization, as part of extended polymeric layers in the extended 3D packing. Hirshfeld surface analysis shows extensive O…H and O…Ca interactions for the phosphonic acid moieties in both calcium structures. MALDI-TOF MS of the hexaphosphonic acid shows nano-arrays consisting of up to a maximum of 28 calixarene units. PMID:20657793

  6. Discovery of phosphonic acid natural products by mining the genomes of 10,000 actinomycetes.

    PubMed

    Ju, Kou-San; Gao, Jiangtao; Doroghazi, James R; Wang, Kwo-Kwang A; Thibodeaux, Christopher J; Li, Steven; Metzger, Emily; Fudala, John; Su, Joleen; Zhang, Jun Kai; Lee, Jaeheon; Cioni, Joel P; Evans, Bradley S; Hirota, Ryuichi; Labeda, David P; van der Donk, Wilfred A; Metcalf, William W

    2015-09-29

    Although natural products have been a particularly rich source of human medicines, activity-based screening results in a very high rate of rediscovery of known molecules. Based on the large number of natural product biosynthetic genes in microbial genomes, many have proposed "genome mining" as an alternative approach for discovery efforts; however, this idea has yet to be performed experimentally on a large scale. Here, we demonstrate the feasibility of large-scale, high-throughput genome mining by screening a collection of over 10,000 actinomycetes for the genetic potential to make phosphonic acids, a class of natural products with diverse and useful bioactivities. Genome sequencing identified a diverse collection of phosphonate biosynthetic gene clusters within 278 strains. These clusters were classified into 64 distinct groups, of which 55 are likely to direct the synthesis of unknown compounds. Characterization of strains within five of these groups resulted in the discovery of a new archetypical pathway for phosphonate biosynthesis, the first (to our knowledge) dedicated pathway for H-phosphinates, and 11 previously undescribed phosphonic acid natural products. Among these compounds are argolaphos, a broad-spectrum antibacterial phosphonopeptide composed of aminomethylphosphonate in peptide linkage to a rare amino acid N(5)-hydroxyarginine; valinophos, an N-acetyl l-Val ester of 2,3-dihydroxypropylphosphonate; and phosphonocystoximate, an unusual thiohydroximate-containing molecule representing a new chemotype of sulfur-containing phosphonate natural products. Analysis of the genome sequences from the remaining strains suggests that the majority of the phosphonate biosynthetic repertoire of Actinobacteria has been captured at the gene level. This dereplicated strain collection now provides a reservoir of numerous, as yet undiscovered, phosphonate natural products.

  7. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  8. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  9. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  10. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  11. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  12. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  13. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  14. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  15. Intermediate temperature proton conductors for PEM fuel cells based on phosphonic acid as protogenic group: a progress report.

    PubMed

    Steininger, H; Schuster, M; Kreuer, K D; Kaltbeitzel, A; Bingöl, B; Meyer, W H; Schauff, S; Brunklaus, G; Maier, J; Spiess, H W

    2007-04-21

    The melting behaviour and transport properties of straight chain alkanes mono- and difunctionalized with phosphonic acid groups have been investigated as a function of their length. The increase of melting temperature and decrease of proton conductivity with increasing chain length is suggested to be the consequence of an increasing ordering of the alkane segments which constrains the free aggregation of the phosphonic acid groups. However, the proton mobility is reduced to a greater extent than the proton diffusion coefficient indicating an increasing cooperativity of proton transport with increasing length of the alkane segment. The results clearly indicate that the "spacer concept", which had been proven successful in the optimization of the proton conductivity of heterocycle based systems, fails in the case of phosphonic acid functionalized polymers. Instead, a very high concentration of phosphonic acid functional groups forming "bulky" hydrogen bonded aggregates is suggested to be essential for obtaining very high proton conductivity. Aggregation is also suggested to reduce condensation reactions generally observed in phosphonic acid containing systems. On the basis of this understanding, the proton conductivities of poly(vinyl phosphonic acid) and poly(meta-phenylene phosphonic acid) are discussed. Though both polymers exhibit a substantial concentration of phosphonic acid groups, aggregation seems to be constrained to such an extent that intrinsic proton conductivity is limited to values below sigma = 10(-3) S cm(-1) at T = 150 degrees C. The results suggest that different immobilization concepts have to be developed in order to minimize the conductivity reduction compared to the very high intrinsic proton conductivity of neat phosphonic acid under quasi dry conditions. In the presence of high water activities, however, (as usually present in PEM fuel cells) the very high ion exchange capacities (IEC) possible for phosphonic acid functionalized ionomers (IEC

  16. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  17. Ligand-Accelerated ortho-C–H Alkylation of Arylcarboxylic Acids Using Alkyl Boron Reagents

    PubMed Central

    Thuy-Boun, Peter S.; Villa, Giorgio; Dang, Devin; Richardson, Paul; Su, Shun; Yu, Jin-Quan

    2013-01-01

    A protocol for the Pd(II)-catalyzed ortho-C–H alkylation of phenylacetic and benzoic acids using alkylboron reagents is disclosed. Mono-protected amino acid ligands (MPAA) were found to significantly promote reactivity. Both potassium alkyltrifluoroborates and alkylboronic acids were compatible coupling partners. The possibility of a radical alkyl transfer to Pd(II) was also investigated. PMID:24124892

  18. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  19. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  20. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  1. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  2. 40 CFR 721.6075 - Phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-tetrakis(1-methylethyl) ester. 721.6075 Section 721.6075 Protection of Environment ENVIRONMENTAL PROTECTION...-methylethyl) ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phosphonic acid, 1,1-methylenebis-tetrakis(1-methylethyl) ester (PMN P-95-168)...

  3. Characterization of linear alkyl phosphonate self-assembled on perovskite substrate

    NASA Astrophysics Data System (ADS)

    Lazauskas, A.; Baltrusaitis, J.; Grigaliūnas, V.; Prosyčevas, I.

    2015-07-01

    In recent years, functional material surface functionalization has grown into an expanding area of research due to the development and design of advanced systems and devices for key areas in biotechnology, smart sensing, environmental applications and manufacturing. In this work, NdNiO3 surface was functionalized with octadecylphosphonic acid (ODP) using liquid phase reaction to attain superhydrophobic properties. The resulting ODP modified surface exhibited dual-scale roughness with a stable static contact angle of 170 ± 2°. Electron microscopy micrographs of ODP crystals formed revealed a non-uniform lateral growth characteristics. The presence of ODP hydrocarbon chains was confirmed using Fourier transform infrared spectroscopy with characteristic peaks at 2924 cm-1 and 2851 cm-1.

  4. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1997-09-01

    The need to increase throughput in alkylation plants has resulted in higher operating temperatures and higher water levels in alkylation acids than projected by design. Combined with higher flow rates, the more severe process environment causes carbon steel to corrode at increased rates. Carbon steel is the main material of construction for horizontal contactors (Stratco reactors). A leak to the atmosphere in the hydraulic end cone of one contactor and the realization that basic corrosion data are not available for high throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in alkylation unit horizontal contactors is successfully mitigated by saturating fresh alkylation acid with ferrous sulfate.

  5. Synthesis of phosphonic analogues of carnitine and gamma-amino-beta-hydroxybutyric acid.

    PubMed

    Tadeusiak, Elzbieta J

    2004-12-01

    The involvement of carnitine and gamma-amino-beta-hydroxybutyric acid in the biology of mammalian cells, the physiology of the human body, and some important aspects of medicinal treatment has induced many research groups to develop their pharmacologically potent analogues. Among them are the very important phosphonic analogues: phosphocarnitine and gamma-amino-beta-hydroxypropylphosphonic acid. This mini-review describes the various methodologies used for the synthesis of these compounds.

  6. In situ chemical functionalization of gallium nitride with phosphonic acid derivatives during etching.

    PubMed

    Wilkins, Stewart J; Greenough, Michelle; Arellano, Consuelo; Paskova, Tania; Ivanisevic, Albena

    2014-03-04

    In situ functionalization of polar (c plane) and nonpolar (a plane) gallium nitride (GaN) was performed by adding (3-bromopropyl) phosphonic acid or propyl phosphonic acid to a phosphoric acid etch. The target was to modulate the emission properties and oxide formation of GaN, which was explored through surface characterization with atomic force microscopy, X-ray photoelectron spectroscopy, photoluminescence (PL), inductively coupled plasma-mass spectrometry, and water contact angle. The use of (3-bromopropyl) phosphonic acid and propyl phosphonic acid in phosphoric acid demonstrated lower amounts of gallium oxide formation and greater hydrophobicity for both sample sets, while also improving PL emission of polar GaN samples. In addition to crystal orientation, growth-related factors such as defect density in bulk GaN versus thin GaN films residing on sapphire substrates were investigated as well as their responses to in situ functionalization. Thin nonpolar GaN layers were the most sensitive to etching treatments due in part to higher defect densities (stacking faults and threading dislocations), which accounts for large surface depressions. High-quality GaN (both free-standing bulk polar and bulk nonpolar) demonstrated increased sensitivity to oxide formation. Room-temperature PL stands out as an excellent technique to identify nonradiative recombination as observed in the spectra of heteroepitaxially grown GaN samples. The chemical methods applied to tune optical and physical properties of GaN provide a quantitative framework for future novel chemical and biochemical sensor development.

  7. Spatially Modulating Interfacial Properties of Transparent Conductive Oxides: Patterning Work Function with Phosphonic Acid Self-Assembled Monolayers

    SciTech Connect

    Knesting, Kristina M.; Hotchkiss, Peter J.; MacLeod, Bradley A.; Marder, Seth R.; Ginger, David S.

    2011-09-29

    The interface between an organic semiconductor and a transparent conducting oxide is crucial to the performance of organic optoelectronics. We use microcontact printing to pattern pentafluorobenzyl phosphonic acid self-assembled monolayers (SAMs) on indium tin oxide (ITO). We obtain high-fidelity patterns with sharply defined edges and with large work function contrast (comparable to that obtained from phosphonic acid SAMs deposited from solution).

  8. An overview of the properties of fatty acid alkyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid alkyl esters of plant oils, especially in the form of methyl esters, have numerous applications with fuel use having received the most attention in recent times due to the potential high volume. Various properties imparted by neat fatty acid alkyl esters have been shown to influence fuel ...

  9. Deaminative and decarboxylative catalytic alkylation of amino acids with ketones.

    PubMed

    Kalutharage, Nishantha; Yi, Chae S

    2013-12-16

    It cuts two ways: The cationic [Ru-H] complex catalyzes selective coupling of α- and β-amino acids with ketones to form α-alkylated ketone products. The reaction involves CC and CN bond cleavage which result in regio- and stereoselective alkylation using amino acids. A broad substrate scope and high functional-group tolerance is demonstrated.

  10. Flower-like supramolecular self-assembly of phosphonic acid appended naphthalene diimide and melamine

    PubMed Central

    Bhosale, Rajesh S; Al Kobaisi, Mohammad; Bhosale, Sidhanath V.; Bhargava, Suresh; Bhosale, Sheshanath V.

    2015-01-01

    Diverse supramolecular assemblies ranging from nanometres to micrometers of small aromatic π-conjugated functional molecules have attracted enormous research interest in light of their applications in optoelectronics, chemosensors, nanotechnology, biotechnology and biomedicines. Here we study the mechanism of the formation of a flower-shaped supramolecular structure of phosphonic acid appended naphthalene diimide with melamine. The flower-shaped assembly formation was visualised by scanning electron microscope (SEM) and transmission electron microscopy (TEM) imaging, furthermore, XRD and DLS used to determined mode of aggregation. Characteristically, phosphonic acid-substituted at imide position of NDIs possess two important properties resulting in the formation of controlled flower-like nanostructures: (i) the aromatic core of the NDI which is designed to optimize the dispersive interactions (π-π stacking and van der Waals interactions) between the cores within a construct and (ii) phosphonic acid of NDI interact with malamine through molecular recognition i.e. strong hydrogen-bonding (H-bonding). We believe such arrangements prevent crystallization and favour the directional growth of flower-like nanostructure in 3D fashion. These works demonstrate that complex self-assembly can indeed be attained through hierarchical non-covalent interactions of two components. Furthermore, flower-like structures built from molecular recognition by these molecules indicate their potential in other fields if combined with other chemical entities. PMID:26416382

  11. Phosphonate utilization by bacteria.

    PubMed Central

    Cook, A M; Daughton, C G; Alexander, M

    1978-01-01

    Bacteria able to use at least one of 13 ionic alkylphosphonates of O-alkyl or O,O-dialkyl alkylphosphonates as phosphorus sources were isolated from sewage and soil. Four of these isolates used 2-aminoethylphosphonic acid (AEP) as a sole carbon, nitrogen, and phosphorus source. None of the other phosphonates served as a carbon source for the organisms. One isolate, identified as Pseudomonas putida, grew with AEP as its sole carbon, nitrogen, and phosphorus source and released nearly all of the organic phosphorus as orthophosphate and 72% of the AEP nitrogen as ammonium. This is the first demonstration of utilization of a phosphonoalkyl moiety as a sole carbon source. Cell-free extracts of P. putida contained an inducible enzyme system that required pyruvate and pyridoxal phosphate to release orthophosphate from AEP; acetaldehyde was tentatively identified as a second product. Phosphite inhibited the enzyme system. PMID:618850

  12. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1999-03-01

    A leak to the atmosphere in the hydraulic end cone of a horizontal contactor and the realization that basic corrosion data are not available for high-throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in the horizontal contractor of an alkylation unit was mitigated successfully by saturating fresh alkylation acid with ferrous sulfate (FeSO{sub 4}).

  13. Atomistic Simulations of Perfluoro Phosphonic and Phosphinic Acid Membranes and Comparisons to Nafion

    SciTech Connect

    Idupulapati, Nagesh B.; Devanathan, Ramaswami; Dupuis, Michel

    2011-03-31

    We used classical molecular dynamics (MD) simulations to investigate the nanoscale morphology and proton transport properties of perfluoro phosphonic (FPA) and phosphinic acid (FPA-I) membranes as they are being considered for use in low temperature fuel cells. We systematically investigated these properties as a function of the hydration level. The changes in nanostructure, in transport dynamics of water and hydronium ions, and in water network percolation were extracted from MD simulations and compared with Nafion. Phosphonic and phosphinic acid moieties in FPA and FPA-I, have lower acidity than sulfonic acid in Nafion, yet the diffusion of water was observed to be faster in FPA and FPA-I than in Nafion, particularly at low hydration levels. However this did not give rise to notable differences in hydronium ion diffusion and water network percolation for these membranes over Nafion. Similar observations were also reported by our group recently in a study of perfluoro-sulfonyl imide membranes carrying stronger super-acids than sulfonic acid of Nafion. These findings together suggest no strong apparent correlation between the acidity strength of the functional acid groups and the dynamics of water and hydronium ions in hydrated polymer electrolyte membranes (PEMs) with similar fluorocarbon backbones and acidic group-carrying side chains. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  14. Novel alpha-hydroxy phosphonic acids via castor oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydroxy fatty acids (HFAs) have found a number of uses in today’s market, with uses ranging from materials to pharmaceuticals. Castor oil has served as a versatile HFA; its principle component, ricinoleic acid, can be isolated from castor oil and has been modified extensively for a number of applica...

  15. Poly(vinylidene fluoride) Containing Phosphonic Acid as Anticorrosion Coating for Steel.

    PubMed

    Banerjee, Sanjib; Wehbi, Mohammad; Manseri, Abdellatif; Mehdi, Ahmad; Alaaeddine, Ali; Hachem, Ali; Ameduri, Bruno

    2017-02-22

    Vinylidene fluoride (VDF)-based copolymers bearing pendant phosphonic acid function for potential application as anticorrosion coatings were synthesized via free radical copolymerization of VDF with a new phosphorus containing 2-trifluoromethacrylate monomer, (dimethoxyphosphoryl)methyl 2-(trifluoromethyl)acrylate (MAF-DMP). MAF-DMP was prepared from 2-trifluoromethacrylic acid in 60% overall yield. Radical copolymerizations of VDF with MAF-DMP initiated by tert-amyl peroxy-2-ethylhexanoate at varying ([VDF]0/[MAF-DMP]0) feed ratios led to several poly(VDF-co-MAF-DMP) copolymers having different molar percentages of VDF (79-96%) and number-average molecular weights (Mn's) up to ca. 10 000 g mol(-1) in fair yields (47-53%). Determination of the composition and microstructure of all the synthesized copolymers was done by (1)H and (19)F NMR spectroscopies. The monomer reactivity ratios of this new VDF/MAF-DMP pair were also determined (rVDF = 0.76 ± 0.34 and rMAF-DMP = 0 at 74 °C). The resulting poly(VDF-co-MAF-DMP) copolymers exhibited high melting temperature (162-171 °C, with respect to the VDF content), and the degree of crystallinity reached up to 51%. Finally, the pendant dimethyl phosphonate ester groups of the synthesized poly(VDF-co-MAF-DMP) copolymer were quantitatively hydrolyzed, giving rise to novel phosphonic acid-functionalized PVDF (PVDF-PA). In comparison to hydrophobic poly(VDF-co-MAF-DMP) copolymers (the water contact angle, WCA, was 98°), the hydrophilic character of the PVDF-PA was found to be surprisingly rather pronounced, exhibiting low WCA (15°). Finally, steel plates coated with PVDF-PA displayed satisfactory anticorrosion properties under simulated seawater environment.

  16. New water-soluble metal working fluids additives from phosphonic acid derivatives for aluminum alloy materials.

    PubMed

    Kohara, Ichitaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short paper describes properties of new additives for water-soluble cutting fluids for aluminum alloy materials. Some alkyldiphosphonic acids were prepared with known method. Amine salts of these phosphonic acids showed anti-corrosion property for aluminum alloy materials. However, they have no hard water tolerance. Monoesters of octylphosphonic acid were prepared by the reaction of octylphosphonic acid dichloride with various alcohols in the presence of triethylamine. Amine salts of monoester of octylphosphonic acid with diethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether and triethyleneglycol monomethyl ether showed both of a good anti-corrosion property for aluminum alloy materials and hard water tolerance.

  17. Exciton-blocking phosphonic acid-treated anode buffer layers for organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Zimmerman, Jeramy D.; Song, Byeongseop; Griffith, Olga; Forrest, Stephen R.

    2013-12-01

    We demonstrate significant improvements in power conversion efficiency of bilayer organic photovoltaics by replacing the exciton-quenching MoO3 anode buffer layer with an exciton-blocking benzylphosphonic acid (BPA)-treated MoO3 or NiO layer. We show that the phosphonic acid treatment creates buffers that block up to 70% of excitons without sacrificing the hole extraction efficiency. Compared to untreated MoO3 anode buffers, BPA-treated NiO buffers exhibit a ˜ 25% increase in the near-infrared spectral response in diphenylanilo functionalized squaraine (DPSQ)/C60-based bilayer devices, increasing the power conversion efficiency under 1 sun AM1.5G simulated solar illumination from 4.8 ± 0.2% to 5.4 ± 0.3%. The efficiency can be further increased to 5.9 ± 0.3% by incorporating a highly conductive exciton blocking bathophenanthroline (BPhen):C60 cathode buffer. We find similar increases in efficiency in two other small-molecule photovoltaic systems, indicating the generality of the phosphonic acid-treated buffer approach to enhance exciton blocking.

  18. The antiviral activity of tetrazole phosphonic acids and their analogues.

    PubMed Central

    Hutchinson, D W; Naylor, M

    1985-01-01

    5-(Phosphonomethyl)-1H-tetrazole and a number of related tetrazoles have been prepared and their effects on the replication of Herpes Simplex Viruses-1 and -2 have been investigated as well as their abilities to inhibit the DNA polymerases induced by these viruses and the RNA transcriptase activity of influenza virus A. Contrary to an earlier report, 5-(phosphonomethyl)-1H-tetrazole was not an efficient inhibitor of the replication of HSV-1 and HSV-2 in tissue culture. Analogues of 5-(phosphonomethyl)-1H-tetrazole were also devoid of significant antiviral activity. Only 5-(phosphonomethyl)-1H-tetrazole and 5-(thiophosphonomethyl)-1H-tetrazole inhibited the influenza virus transcriptase, and both were more effective as inhibitors than phosphonoacetic acid under the same conditions. The DNA polymerases induced by HSV-1 and HSV-2 were inhibited slightly by 5-(phosphonomethyl)-1H-tetrazole and to a lesser extent by its N-ethyl analogue and 3-(phosphonomethyl)-1H-1,2,4-triazole. None of these compounds were as effective as phosphonoacetic acid. 5-(Thiophosphonomethyl)-1H-tetrazole was a better inhibitor of the DNA polymerase induced by HSV-1 than 5-(phosphonomethyl)-1H-tetrazole. PMID:2417198

  19. Screening of nerve agent markers with hollow fiber-chemosorption of phosphonic acids.

    PubMed

    Holmgren, Karin Höjer; Gustafsson, Tomas; Östin, Anders

    2016-10-15

    This report describes a method developed for extracting nerve gas markers such as phosphonic acids from urine and other aqueous samples. It involves single-step microextraction with chemosorption to hollow fibers that have been pre-soaked in a solution containing a derivatization reagent (3,5 triflouro methyl benzene diazomethane). The derivatives it forms with phosphonic acids can be sensitively detected by mass spectrometric detectors operating in negative chemical ionization (NCI) mode. Limits of quantification obtained in analyses of water and urine extracts by GC/MS in negative chemical ionization and selected ion monitoring mode were 0.1-10 and 0.5-10ng/mL, respectively. Pentaflourophenyl diazomethane can also be used as a derivatization reagent, and the micro-extracts (which generate low background signals) can be sensitively analyzed by GC-MS/MS in NCI selected reaction monitoring (SRM) mode, using two specific transitions for both reagents. Thus, this sensitive approach can be flexibly modified to obtain confirmatory information, or address potential problems caused by interferences in some samples.

  20. Conserved biosynthetic pathways for phosalacine, bialaphos and newly discovered phosphonic acid natural products

    PubMed Central

    Blodgett, Joshua A. V; Zhang, Jun Kai; Yu, Xiaomin; Metcalf, William W.

    2015-01-01

    Natural products containing phosphonic or phosphinic acid functionalities often display potent biological activities with applications in medicine and agriculture. The herbicide phosphinothricin-tripeptide (PTT) was the first phosphinate natural product discovered, yet despite numerous studies, questions remain surrounding key transformations required for its biosynthesis. In particular, the enzymology required to convert phosphonoformate to carboxyphosphonoenolpyruvate and the mechanisms underlying phosphorus-methylation remain poorly understood. In addition, the model for NRPS assembly of the intact tripeptide product has undergone numerous revisions that have yet to be experimentally tested. To further investigate the biosynthesis of this unusual natural product, we completely sequenced the PTT biosynthetic locus from Streptomyces hygroscopicus and compared it to the orthologous cluster from Streptomyces viridochromogenes. We also sequenced and analysed the closely related phosalacine (PAL) biosynthetic locus from Kitasatospora phosalacinea. Using data drawn from the comparative analysis of the PTT and PAL pathways, we also evaluate three related recently discovered phosphonate biosynthetic loci from Streptomyces sviceus, Streptomyces sp. WM6386 and Frankia alni. Our observations address long-standing biosynthetic questions related to PTT and PAL production and suggest that additional members of this pharmacologically important class await discovery. PMID:26328935

  1. Conserved biosynthetic pathways for phosalacine, bialaphos and newly discovered phosphonic acid natural products.

    PubMed

    Blodgett, Joshua A V; Zhang, Jun Kai; Yu, Xiaomin; Metcalf, William W

    2016-01-01

    Natural products containing phosphonic or phosphinic acid functionalities often display potent biological activities with applications in medicine and agriculture. The herbicide phosphinothricin-tripeptide (PTT) was the first phosphinate natural product discovered, yet despite numerous studies, questions remain surrounding key transformations required for its biosynthesis. In particular, the enzymology required to convert phosphonoformate to carboxyphosphonoenolpyruvate and the mechanisms underlying phosphorus methylation remain poorly understood. In addition, the model for non-ribosomal peptide synthetase assembly of the intact tripeptide product has undergone numerous revisions that have yet to be experimentally tested. To further investigate the biosynthesis of this unusual natural product, we completely sequenced the PTT biosynthetic locus from Streptomyces hygroscopicus and compared it with the orthologous cluster from Streptomyces viridochromogenes. We also sequenced and analyzed the closely related phosalacine (PAL) biosynthetic locus from Kitasatospora phosalacinea. Using data drawn from the comparative analysis of the PTT and PAL pathways, we also evaluate three related recently discovered phosphonate biosynthetic loci from Streptomyces sviceus, Streptomyces sp. WM6386 and Frankia alni. Our observations address long-standing biosynthetic questions related to PTT and PAL production and suggest that additional members of this pharmacologically important class await discovery.

  2. Benefits of the stirred, autorefrigerated reactor in sulfuric acid alkylation

    SciTech Connect

    Ackerman, S.; Lerner, H.; Zaczepinski, S.

    1996-12-01

    Alkylation is a process which combines propylenes, butylenes, and pentylenes with isobutane in the presence of an acid catalyst (H{sub 2}SO{sub 4} or HF) to produce a premium quality gasoline blendstock. The alkylation process was developed in the late 1930`s and processing capacity grew tremendously during World War II in response to demand for aviation gasoline. Since that time, alkylation capacity has steadily grown to supply an important motor gasoline component. Now, more than 50 years later, alkylation is in the spotlight again for reformulated gasoline. Alkylate is a high octane, low sensitivity, low RVP, totally paraffinic material which represents the ideal blendstock for modern gasoline manufacture. Two types of modern reactor systems are currently offered for license to the refining industry for sulfuric acid alkylation. These are the stirred, autorefrigerated system offered by Exxon Research and Engineering (ERE) and the indirect, or effluent refrigerated system offered by others. By means of a case study example, this paper discusses the autorefrigerated reaction system and its benefits.

  3. Directed Regulation of Multienzyme Complexes of 2-Oxo Acid Dehydrogenases Using Phosphonate and Phosphinate Analogs of 2-Oxo Acids.

    PubMed

    Artiukhov, A V; Graf, A V; Bunik, V I

    2016-12-01

    2-Oxo acid dehydrogenase complexes are important metabolic checkpoints functioning at the intercept of sugar and amino acid degradation. This review presents a short summary of architectural, catalytic, and regulatory principles of the complexes structure and function, based on recent advances in studies of well-characterized family members. Special attention is given to use of synthetic phosphonate and phosphinate analogs of 2-oxo acids as selective and efficient inhibitors of the cognate complexes in biological systems of bacterial, plant, and animal origin. We summarize our own results concerning the application of synthetic analogs of 2-oxo acids in situ and in vivo to reveal functional interactions between 2-oxo acid dehydrogenase complexes and other components of metabolic networks specific to different cells and tissues. Based on our study of glutamate excitotoxicity in cultured neurons, we show how a modulation of metabolism by specific inhibition of its key reaction may be employed to correct pathologies. This approach is further developed in our study on the action of the phosphonate analog of 2-oxoglutarate in animals. The study revealed that upregulation of 2-oxoglutarate dehydrogenase complex is involved in animal stress response and may provide increased resistance to damaging effects, underlying so-called preconditioning. The presented analysis of published data suggests synthetic inhibitors of metabolic checkpoints as promising tools to solve modern challenges of systems biology, metabolic engineering, and medicine.

  4. A report on emergent uranyl binding phenomena by an amidoxime phosphonic acid co-polymer

    SciTech Connect

    Abney, C. W.; Das, S.; Mayes, R. T.; Kuo, L. -J.; Wood, J.; Gill, G.; Piechowicz, M.; Lin, Z.; Lin, W.; Dai, S.

    2016-01-01

    The development of technology to harvest the uranium dissolved in seawater would enable access to vast quantities of this critical metal for nuclear power generation. Amidoxime polymers are the most promising platforms for achieving this separation, yet the design of advanced adsorbents is hindered by uncertainty regarding the uranium binding mode. In this work we use XAFS to investigate the uranium coordination environment in an amidoxime–phosphonic acid copolymer adsorbent. In contrast to the binding mode predicted computationally and from small molecule studies, a cooperative chelating model is favoured, attributable to emergent behavior resulting from inclusion of amidoxime in the polymer. Samples exposed to seawater also display a feature consistent with a μ2-oxo-bridged transition metal, suggesting the formation of an in situ specific binding site. These findings challenge long held assumptions and provide new opportunities for the design of advanced adsorbent materials.

  5. A report on emergent uranyl binding phenomena by an amidoxime phosphonic acid co-polymer

    DOE PAGES

    Abney, C. W.; Das, S.; Mayes, R. T.; ...

    2016-08-01

    Development of technology to harvest the uranium dissolved in seawater would enable access to vast quantities of this critical metal for nuclear power generation. Amidoxime polymers are the most promising platform for achieving this separation, yet design of advanced adsorbents is hindered by uncertainty regarding the uranium binding mode. In this work we use XAFS to investigate the uranium coordination environment in an amidoxime-phosphonic acid copolymer adsorbent. In contrast to the binding mode predicted computationally and from small molecule studies, a cooperative chelating model is favoured, attributable to emergent behavior resulting from inclusion of amidoxime in a polymer. Samples exposedmore » to seawater also display a feature consistent with a 2-oxo-bridged transition metal, suggesting formation of an in situ specific binding site. As a result, these findings challenge long held assumptions and provide new opportunities for the design of advanced adsorbent materials.« less

  6. A report on emergent uranyl binding phenomena by an amidoxime phosphonic acid co-polymer

    SciTech Connect

    Abney, C. W.; Das, S.; Mayes, R. T.; Kuo, L. -J.; Wood, J.; Gill, G.; Piechowicz, M.; Lin, Z.; Lin, W.; Dai, S.

    2016-08-01

    Development of technology to harvest the uranium dissolved in seawater would enable access to vast quantities of this critical metal for nuclear power generation. Amidoxime polymers are the most promising platform for achieving this separation, yet design of advanced adsorbents is hindered by uncertainty regarding the uranium binding mode. In this work we use XAFS to investigate the uranium coordination environment in an amidoxime-phosphonic acid copolymer adsorbent. In contrast to the binding mode predicted computationally and from small molecule studies, a cooperative chelating model is favoured, attributable to emergent behavior resulting from inclusion of amidoxime in a polymer. Samples exposed to seawater also display a feature consistent with a 2-oxo-bridged transition metal, suggesting formation of an in situ specific binding site. As a result, these findings challenge long held assumptions and provide new opportunities for the design of advanced adsorbent materials.

  7. Effects of radiation, acid, and base on the extractant dihexyl-(diethylcarbamoyl)methyl) phosphonate

    SciTech Connect

    Bahner, C.T.; Shoun, R.R.; McDowell, W.J.

    1981-11-01

    The effects of exposure to gamma radiation (/sup 60/Co) and of contact with acidic and basic aqueous solutions on dihexyl((diethylcarbamoyl)methyl)phosphonate (DHDECMP) were studied. Gamma radiation decomposes DHDECMP into a variety of products. The most troublesome of those are the acidic compounds that cause problems in stripping the actinides and lanthanides from the extractant at low acid concentrations. The rate of degradation of DHDECMP by radiation is about the same or only slightly higher than that of tri-n-butyl phosphate (TBP). It is relatively easy to remove the radiation-produced impurities by equilibration (scrubbing) with sodium carbonate or sodium hydroxide or by column chromatographic methods. The hydrolysis of DHDECMP in contact with aqueous solutions containing less than 3 M HNO/sub 3/ is not more severe than that of TBP under the same conditions but is significant above that acid concentration. Hydrolysis of DHDECMP in contact with aqueous sodium hydroxide solution does occur, but it should not pose an important problem with the short contact times such as those anticipated for the removal of the radiation-induced degradation products by caustic scrubbing. Results of various chromatographic tests to characterize the degradation products of DHDECMP are also given.

  8. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  9. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  10. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl polycarboxylic acids, esters... Significant New Uses for Specific Chemical Substances § 721.6475 Alkyl polycarboxylic acids, esters with... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated...

  11. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  12. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  13. Substituted ethan phosphonic acid esters as reagents for the separation of molybdenum from rhenium by solvent extraction.

    PubMed

    Jordanov, N; Mareva, S; Borisov, G; Jordanov, B

    1968-02-01

    New esters of the ethan phosphonic acids have been synthesized and their extraction properties studied with respect to Mo(VI), Re(VII), Fe(III),Au(III),Tl(III) and Sb(V). A possibility is shown for the analytical separation of molybdenum from rhenium (beta = 700). The state of these new extraction agents in carbon tetrachloride solution, and the mechanism of the extraction processes, have been investigated by means of infrared spectra.

  14. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    PubMed

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  15. Phosphonic acid functionalized poly(pentafluorostyrene) as polyelectrolyte membrane for fuel cell application

    NASA Astrophysics Data System (ADS)

    Atanasov, Vladimir; Oleynikov, Andrey; Xia, Jiabing; Lyonnard, Sandrine; Kerres, Jochen

    2017-03-01

    In this paper we introduce polyelectrolyte membranes based on phosphonated poly(pentafluorostyrene) (PPFS) and their performances in a fuel cell. The polyelectrolytes were obtained via partial phosphonation of PPFS varying the phosphonation degree from 17 to 66%. These membranes showed a high resistance to temperature (Tdecomp. = 355-381 °C) and radical attack (96-288 h in Fenton's test). A blend membrane consisting of 82 wt% fully phosphonated PPFS and 18 wt% poly(benzimidazole) is compared to the 66% phosphonated membrane having similar ion-conductivity (σ = 57 mS cm-1 at 120 °C, 90% RH). In the fuel cell the blend showed the best performance reaching 0.40 W cm-2 against 0.34 W cm-2 for the 42 wt% phosphonated membrane and 0.35 W cm-2 for Nafion 212. Furthermore, the blend maintained its operation at potentiostatic regime (0.5 V) for 620 h without declining in its performance. The highest power density of 0.78 W cm-2 was reached for the blend with a thickness of 15 μm using humidified oxygen (RH > 90%) at the cathode side. The switch from humidified to dry gasses during operation reduced the current density down to 0.6 A cm-2, but the cell maintained under operation for 66 h.

  16. Tailored control and optimisation of the number of phosphonic acid termini on phosphorus-containing dendrimers for the ex-vivo activation of human monocytes.

    PubMed

    Rolland, Olivier; Griffe, Laurent; Poupot, Mary; Maraval, Alexandrine; Ouali, Armelle; Coppel, Yannick; Fournié, Jean-Jacques; Bacquet, Gérard; Turrin, Cédric-Olivier; Caminade, Anne-Marie; Majoral, Jean-Pierre; Poupot, Rémy

    2008-01-01

    The syntheses of a series of phosphonic acid-capped dendrimers is described. This collection is based on a unique set of dendritic structural parameters-cyclo(triphosphazene) core, benzylhydrazone branches and phosphonic acid surface-and was designed to study the influence of phosphonate (phosphonic acid) surface loading towards the activation of human monocytes ex vivo. Starting from the versatile hexachloro-cyclo(triphosphazene) N(3)P(3)Cl(6), six first-generation dendrimers were obtained, bearing one to six full branches, that lead to 4, 8, 12, 16, 20 and 24 phosphonate termini, respectively. The surface loading was also explored at the limit of dense packing by means of a first-generation dendrimer having a cyclo(tetraphosphazene) core and bearing 32 termini, and with a first-generation dendrimer based on a AB(2)/CD(5) growing pattern and bearing 60 termini. Human monocyte activation by these dendrimers confirms the requirement of the whole dendritic structure for bioactivity and identifies the dendrimer bearing four branches, thus 16 phosphonate termini, as the most bioactive.

  17. Synthesis of Alkyl Methylphosphonic Acid Esters

    SciTech Connect

    Mong, Gary M.; Harvey, Scott D.; Campbell, James A.

    2005-08-01

    This manuscript describes a simple synthesis and purification of cyclohexyl methylphosphonic and isopropyl methylphosphonic acids that provides high purity (>95% purity) product in gram quantities. Based on needs for improved analytical methods for indirect detection of nerve agent use, there is an increasing demand for these nerve agent hydrolysis products. These products are not commercially available. Synthesis is based on reaction of equimolar amounts of alcohol with methylphosphonic dichloride in toluene followed by the addition of excess water (two mole equivalents). The product was then extracted from the resulting aqueous layer into chloroform. The extraction scheme proved highly effective in removing unreacted starting materials and reaction by-products.

  18. A Metabolically-Stabilized Phosphonate Analog of Lysophosphatidic Acid Attenuates Collagen-Induced Arthritis

    PubMed Central

    Sevastou, Ioanna; Sirioti, Ivi; Samiotaki, Martina; Madan, Damian; Prestwich, Glenn D.; Aidinis, Vassilis

    2013-01-01

    Rheumatoid arthritis (RA) is a destructive arthropathy with systemic manifestations, characterized by chronic synovial inflammation. Under the influence of the pro-inflammatory milieu synovial fibroblasts (SFs), the main effector cells in disease pathogenesis become activated and hyperplastic while releasing a number of signals that include pro-inflammatory factors and tissue remodeling enzymes. Activated RA SFs in mouse or human arthritic joints express significant quantities of autotaxin (ATX), a lysophospholipase D responsible for the majority of lysophosphatidic acid (LPA) production in the serum and inflamed sites. Conditional genetic ablation of ATX from SFs resulted in attenuation of disease symptoms in animal models, an effect attributed to diminished LPA signaling in the synovium, shown to activate SF effector functions. Here we show that administration of 1-bromo-3(S)-hydroxy-4-(palmitoyloxy)butyl-phosphonate (BrP-LPA), a metabolically stabilized analog of LPA and a dual function inhibitor of ATX and pan-antagonist of LPA receptors, attenuates collagen induced arthritis (CIA) development, thus validating the ATX/LPA axis as a novel therapeutic target in RA. PMID:23923032

  19. Transcriptional and cellular responses of the green alga Chlamydomonas reinhardtii to perfluoroalkyl phosphonic acids.

    PubMed

    Sanchez, David; Houde, Magali; Douville, Mélanie; De Silva, Amila O; Spencer, Christine; Verreault, Jonathan

    2015-03-01

    Perfluoroalkyl phosphonic acids (PFPAs), a new class of perfluoroalkyl substances used primarily in the industrial sector as surfactants, were recently detected in surface water and wastewater treatment plant effluents. Toxicological effects of PFPAs have as yet not been investigated in aquatic organisms. The objective of the present study was to evaluate the effects of perfluorooctylphosphonic acid (C8-PFPA) and perfluorodecylphosphonic acid (C10-PFPA) exposure (31-250μg/L) on Chlamydomonas reinhardtii using genomic (qRT-PCR), biochemical (reactive oxygen species production (ROS) and lipid peroxidation), and physiological (cellular viability) indicators. After 72h of exposure, no differences were observed in cellular viability for any of the two perfluorochemicals. However, increase in ROS concentrations (36% and 25.6% at 125 and 250μg/L, respectively) and lipid peroxidation (35.5% and 35.7% at 125 and 250μg/L, respectively) was observed following exposure to C10-PFPA. C8-PFPA exposure did not impact ROS production and lipid peroxidation in algae. To get insights into the molecular response and modes of action of PFPA toxicity, qRT-PCR-based assays were performed to analyze the transcription of genes related to antioxidant responses including superoxide dismutase (SOD-1), glutathione peroxidase (GPX), catalase (CAT), glutathione S-transferase (GST), and ascorbate peroxidase (APX I). Genomic analyses revealed that the transcription of CAT and APX I was up-regulated for all the C10-PFPA concentrations. In addition, PFPAs were quantified in St. Lawrence River surface water samples and detected at concentrations ranging from 250 to 850pg/L for C8-PFPA and 380 to 650pg/L for C10-PFPA. This study supports the prevalence of PFPAs in the aquatic environment and suggests potential impacts of PFPA exposure on the antioxidant defensive system in C. reinhardtii.

  20. Preparation, characterization, and modeling of α-zirconium phosphonates with ether-functional surfaces

    PubMed Central

    Furman, Benjamin R.; Wellinghoff, Stephen T.; Thompson, Paul M.; Beall, Gary W.; Laine, Richard M.; Rawls, H. Ralph

    2009-01-01

    Layered α-zirconium(IV) phosphonates were prepared from novel ether-terminal alkyl phosphonic acids, providing nanoplatelets with brush-like polar surfaces. The precursor materials were characterized by NMR, mass spectrometry, and elemental analysis. The derived nanoparticles were examined by XRD, TEM, TGA, and elemental analysis. The experimental compositions were slightly rich in organophosphorus content. In general, the layered materials had good crystallinity, with layer reflections appearing up to (005) and d-spacings consistent with the anticipated α-phase structure. Computer simulations suggest that tailored surface chemistries, including ether functionalities, will offer favorable thermodynamic interactions with polyester polymer matrices. PMID:20090854

  1. The Effect of Supercritical Fluids on Solid Acid Catalyst Alkylation

    SciTech Connect

    Ginosar, Daniel Michael; Thompson, David Neil; Burch, Kyle Coates; Zalewski, D. J.

    2002-05-01

    The alkylation of isobutane with trans-2-butene was explored over six solid acid catalysts in the liquid, near-critical liquid, and supercritical regions through the addition of an inert cosolvent to the reaction feed mixture. The addition of supercritical cosolvents did not result in sustained catalytic alkylation activity. A modest improvement in product yield was obtained with the addition of methane in the modified-liquid region; however, catalyst longevity and product selectivity were decreased compared to cosolvent-free liquid conditions. This paper describes the catalyst screening and selection process, an exploration of catalyst performance with varying concentrations of methane, and an examination of the effects of seven supercritical fluids on catalyst performance. The catalysts included two zeolites, two sulfated metal oxides, and two Nafion catalysts. Three hydrocarbons, two fluorocarbons, carbon dioxide, and sulfur hexafluoride were explored as inert cosolvents added to the reaction mixture.

  2. Effect of Time and Deposition Method on Quality of Phosphonic Acid Modifier Self-Assembled Monolayers on Indium Zinc Oxide

    SciTech Connect

    Sang, Lingzi; Knesting, Kristina M.; Bulusu, Anuradha; Sigdel, Ajaya K.; Giordano, Anthony J.; Marder, Seth R.; Berry, Joseph J.; Graham, Samuel; Ginger, David S.; Pemberton, Jeanne E.

    2016-12-15

    Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F5BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after -48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F13-octylphosphonic acid (F13OPA), and pentafluorinated benzyl phosphonic acid (F5BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48-168 h solution deposition at both room temperature and 70 degrees C result in contamination- and surface etch-free close-packed monolayers with good reproducibility. SAMs fabricated by micro-contact printing and spray coating are much less well ordered.

  3. Effect of time and deposition method on quality of phosphonic acid modifier self-assembled monolayers on indium zinc oxide

    NASA Astrophysics Data System (ADS)

    Sang, Lingzi; Knesting, Kristina M.; Bulusu, Anuradha; Sigdel, Ajaya K.; Giordano, Anthony J.; Marder, Seth R.; Berry, Joseph J.; Graham, Samuel; Ginger, David S.; Pemberton, Jeanne E.

    2016-12-01

    Phosphonic acid (PA) self-assembled monolayers (SAMs) are utilized at critical interfaces between transparent conductive oxides (TCO) and organic active layers in organic photovoltaic devices (OPVs). The effects of PA deposition method and time on the formation of close-packed, high-quality monolayers is investigated here for SAMs fabricated by solution deposition, micro-contact printing, and spray coating. The solution deposition isotherm for pentafluorinated benzylphosphonic acid (F5BnPA) on indium-doped zinc oxide (IZO) is studied using polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) at room temperature as a model PA/IZO system. Fast surface adsorption occurs within the first min; however, well-oriented high-quality SAMs are reached only after ∼48 h, presumably through a continual process of molecular adsorption/desorption and monolayer filling accompanied by molecular reorientation. Two other rapid, soak-free deposition techniques, micro-contact printing and spray coating, are also explored. SAM quality is compared for deposition of phenyl phosphonic acid (PPA), F13-octylphosphonic acid (F13OPA), and pentafluorinated benzyl phosphonic acid (F5BnPA) by solution deposition, micro-contact printing and spray coating using PM-IRRAS. In contrast to micro-contact printing and spray coating techniques, 48-168 h solution deposition at both room temperature and 70 °C result in contamination- and surface etch-free close-packed monolayers with good reproducibility. SAMs fabricated by micro-contact printing and spray coating are much less well ordered.

  4. Bioaccumulation of perfluorinated alkyl acids: observations and models.

    PubMed

    Ng, Carla A; Hungerbühler, Konrad

    2014-05-06

    In this review, we consider the two prevailing hypotheses for the mechanisms that control the bioaccumulation of perfluorinated alkyl acids (PFAAs). The first assumes that partitioning to membrane phospholipids, which have a higher affinity for charged species than neutral storage lipids, can explain the high bioaccumulation potential of these compounds. The second assumes that interactions with proteins--including serum albumin, liver fatty acid binding proteins (L-FABP), and organic anion transporters--determine the distribution, accumulation and half-lives of PFAAs. We consider three unique phenomena to evaluate the two models: (1) observed patterns of tissue distribution in the laboratory and field, (2) the relationship between perfluorinated chain length and bioaccumulation, and (3) species- and gender-specific variation in elimination half-lives. Through investigation of these three characteristics of PFAA bioaccumulation, we show the strengths and weaknesses of the two modeling approaches. We conclude that the models need not be mutually exclusive, but that protein interactions are needed to explain some important features of PFAA bioaccumulation. Although open questions remain, further research should include perfluorinated alkyl substances (PFASs) beyond the long-chain PFAAs, as these substances are being phased out and replaced by a wide variety of PFASs with largely unknown properties and bioaccumulation behavior.

  5. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic)....

  6. 40 CFR 721.10664 - Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic). 721.10664 Section 721.10664... Alkenedioic acid dialkyl ester, reaction products with alkenoic acid alkyl esters and diamine (generic)....

  7. Synthesis of highly phosphonic acid functionalized benzene-bridged periodic mesoporous organosilicas for use as efficient dye adsorbents.

    PubMed

    Deka, Juti Rani; Liu, Chia-Ling; Wang, Tzu-Hua; Chang, Wei-Chieh; Kao, Hsien-Ming

    2014-08-15

    Periodic mesoporous organosilicas (PMOs) with benzene bridging groups in the silica wall were functionalized with a tunable content of phosphonic acid groups. These bifunctional materials were synthesized by co-condensation of two different organosilane precursors, that is, 1,4-bis(triethoxysilyl)benzene (BTEB) and sodium 3-(trihydroxysilyl)propyl methyl phosphate (SPMP), under acidic conditions using nonionic surfactant Brij-S10 as template. The materials exhibited well-ordered mesostructures and were characterized by X-ray diffraction, nitrogen sorption, TEM, TGA, FTIR, and solid-state NMR measurements. The materials thus obtained were employed as adsorbents to remove different types of dyes, for example, cationic dyes methylene blue and phenosafranine, anionic orange II, and amphoteric rhodamine B, from aqueous solutions. The materials exhibited a remarkably high adsorption capacity than activated carbon due to their ordered mesostructures, a large number of phosphonic acid groups, and high surface areas. The adsorption was mainly governed by electrostatic interaction, but also involved π-π stacking interaction as well as hydrogen bonding. The adsorption kinetics can be better fitted by the pseudo-second order model. The adsorption process was controlled by the mechanisms of external mass transfer and intraparticle diffusion. The materials retained more than 97% dye removal efficiency after use for five consecutive cycles.

  8. Solid-acid alkylation process development is at a crucial stage

    SciTech Connect

    Rao, P.; Vatcha, S.R.

    1996-09-09

    The refining industry is seeking more environmentally acceptable and economical methods of producing reformulated gasoline (RFG). Alkylate, the cleanest gasoline-blending stream produced in a refinery, is a prime blend stock for RFG production. Alkylation with solid acid catalysts has potential environmental and safety advantages over conventional liquid-acid alkylation. This is especially true for the HF alkylation process. Difficult technical challenges must be overcome in the next few years to achieve a commercially successful solid-acid alylation process. Substantial innovations in catalysts, catalyst regeneration, reactor design, and product separation will be required for solid catalyst processes to replace the incumbent processes, which are being improved continually. The paper discusses background, HF alkylation, H{sub 2}SO{sub 4} alkylation, solid-acid catalysts, reaction mechanism, activity and selectivity, feedstock effects, catalyst life, resistance to poisons, reactors and processes, business issues, and R and D guidelines.

  9. Sol-gel synthesis of tantalum oxide and phosphonic acid-modified carbon nanotubes composite coatings on titanium surfaces.

    PubMed

    Maho, Anthony; Detriche, Simon; Delhalle, Joseph; Mekhalif, Zineb

    2013-07-01

    Carbon nanotubes used as fillers in composite materials are more and more appreciated for the outstanding range of accessible properties and functionalities they generate in numerous domains of nanotechnologies. In the framework of biological and medical sciences, and particularly for orthopedic applications and devices (prostheses, implants, surgical instruments, …), titanium substrates covered by tantalum oxide/carbon nanotube composite coatings have proved to constitute interesting and successful platforms for the conception of solid and biocompatible biomaterials inducing the osseous regeneration processes (hydroxyapatite growth, osteoblasts attachment). This paper describes an original strategy for the conception of resistant and homogeneous tantalum oxide/carbon nanotubes layers on titanium through the introduction of carbon nanotubes functionalized by phosphonic acid moieties (-P(=O)(OH)2). Strong covalent C-P bonds are specifically inserted on their external sidewalls with a ratio of two phosphonic groups per anchoring point. Experimental results highlight the stronger "tantalum capture agent" effect of phosphonic-modified nanotubes during the sol-gel formation process of the deposits compared to nanotubes bearing oxidized functions (-OH, -C=O, -C(=O)OH). Particular attention is also paid to the relative impact of the rate of functionalization and the dispersion degree of the carbon nanotubes in the coatings, as well as their wrapping level by the tantalum oxide matrix material. The resulting effect on the in vitro growth of hydroxyapatite is also evaluated to confirm the primary osseous bioactivity of those materials. Chemical, structural and morphological features of the different composite deposits described herein are assessed by X-ray photoelectron spectroscopy (XPS), scanning (SEM) and transmission (TEM) electronic microscopies, energy dispersive X-rays analysis (EDX) and peeling tests.

  10. Synthesis of novel castor oil phosphonates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Castor oil has served as a versatile hydroxy fatty acid (HFA); its principle component, ricinoleic acid, can be isolated from castor oil and has been modified extensively for a number of applications. Additionally, phosphonates and their corresponding phosphonic acids are a functional moiety that ha...

  11. Covalent attachment of diamondoid phosphonic acid dichlorides to tungsten oxide surfaces.

    PubMed

    Li, Fei Hua; Fabbri, Jason D; Yurchenko, Raisa I; Mileshkin, Alexander N; Hohman, J Nathan; Yan, Hao; Yuan, Hongyuan; Tran, Ich C; Willey, Trevor M; Bagge-Hansen, Michael; Dahl, Jeremy E P; Carlson, Robert M K; Fokin, Andrey A; Schreiner, Peter R; Shen, Zhi-Xun; Melosh, Nicolas A

    2013-08-06

    Diamondoids (nanometer-sized diamond-like hydrocarbons) are a novel class of carbon nanomaterials that exhibit negative electron affinity (NEA) and strong electron-phonon scattering. Surface-bound diamondoid monolayers exhibit monochromatic photoemission, a unique property that makes them ideal electron sources for electron-beam lithography and high-resolution electron microscopy. However, these applications are limited by the stability of the chemical bonding of diamondoids on surfaces. Here we demonstrate the stable covalent attachment of diamantane phosphonic dichloride on tungsten/tungsten oxide surfaces. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) spectroscopy revealed that diamondoid-functionalized tungsten oxide films were stable up to 300-350 °C, a substantial improvement over conventional diamondoid thiolate monolayers on gold, which dissociate at 100-200 °C. Extreme ultraviolet (EUV) light stimulated photoemission from these diamondoid phosphonate monolayers exhibited a characteristic monochromatic NEA peak with 0.2 eV full width at half-maximum (fwhm) at room temperature, showing that the unique monochromatization property of diamondoids remained intact after attachment. Our results demonstrate that phosphonic dichloride functionality is a promising approach for forming stable diamondoid monolayers for elevated temperature and high-current applications such as electron emission and coatings in micro/nano electromechanical systems (MEMS/NEMS).

  12. Effects of steroidal allenic phosphonic acid derivatives on the parasitic protists Leishmania donovani, Leishmania mexicana mexicana, and Pneumocystis carinii carinii.

    PubMed Central

    Beach, D H; Chen, F; Cushion, M T; Macomber, R S; Krudy, G A; Wyder, M A; Kaneshiro, E S

    1997-01-01

    Several pathogenic fungi and protozoa are known to have sterols distinct from those of their mammalian hosts. Of particular interest as targets for drug development are the biosyntheses of the sterols of important parasites such as the kinetoplastid flagellates and the AIDS-associated opportunistic protist Pneumocystis carinii. These pathogens synthesize sterols with an alkyl group at C-24, and some have a double bond at C-22 of the side chain. Humans and other mammalian hosts are incapable of C-24 alkylation and C-22 desaturation. In the present study, three steroidal compounds with side chains substituted by phosphonyl-linked groups were synthesized and tested for their effects on Leishmania donovani and L. mexicana mexicana culture growth. The compounds inhibited organism proliferation at concentrations in micrograms per milliliter. The most potent inhibitors of this group of compounds were characterized by two ethyl groups at the phosphate function. Leishmania organisms treated with 17-[2-(diethylphosphonato) ethylidienyl]3-methoxy-19-norpregna-1,3,5-triene exhibited reduced growth after transfer into inhibitor-free medium. Because there are currently no axenic methods available for the continuous subcultivation of P. carinii, the effects of these drugs on this organism were evaluated by two alternative screening methods. The same two diethyl phosphonosteroid compounds that inhibited Leishmania proliferation were also the most active against P. carinii as determined by the potent effect they had on reducing cellular ATP content. Cystic as well as trophic forms responded to the drug treatments, as evaluated by a dual fluorescent staining live-dead assay. Other modifications of steroidal phosphonates may lead to the development of related drugs with increased activity and specificity for the pathogens. PMID:8980773

  13. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  14. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  15. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  16. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  17. 40 CFR 721.6477 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... with ethoxylated fatty alcohols, reaction products with maleic anhydride. 721.6477 Section 721.6477... Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols, reaction products with maleic... identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols,...

  18. A comparative analysis of pharmacokinetics properties of diagnostic bone-seeking radiopharmaceuticals on the basis of phosphonic acids and technetium-99m

    NASA Astrophysics Data System (ADS)

    Tishchenko, V. K.; Petriev, V. M.; Smoryzanova, O. A.; Zavestovskaya, I. N.

    2017-01-01

    This work is devoted to comparative research of pharmacokinetics properties of four bone-seeking radiopharmaceuticals (RPP) on the basis of bi- tetra- and penta-phosphonic acids. Biodistribution studies were performed in intact rats after intravenous injections of 99mTc-hydroxyethylidenediphosphonic acid (99mTc-HEDP), 99mTc-oxabiphor (99mTc-OXB), 99mTc-ethylenediaminetetramethylenephosphonic acid (99mTc-EDTMP) or 99mTc-diethylenetriaminopentakis(methylphosphonic acid) (99mTc-PPA). In the structure of the HEDP contains two phosphonic groups, OENTMP and EDTMP – four phosphonic groups, PPA – five phosphonic groups. Radiochemical yield of labeled 99mTc HEDP, OENTMP, EDTMP, PPA is not less than 95%, the radiochemical impurities does not exceed 5%. The investigated compounds have high stability in vivo and selective accumulation in osseous tissue. The highest concentrations of labeled compounds is reached in 3–24 hours after their intravenous injections. The investigated compounds are rapidly excreted from blood and soft organs and tissues mainly through the urinary routes. So present study has showed that these RPP have properties, which making them promising candidates as a diagnostic pharmaceuticals of bone metastases.

  19. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl amino substituted triazine...

  20. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl amino substituted triazine...

  1. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl amino substituted triazine...

  2. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl amino substituted triazine...

  3. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl amino substituted triazine...

  4. Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids.

    PubMed

    Fu, Ming-Chen; Shang, Rui; Cheng, Wan-Min; Fu, Yao

    2015-07-27

    A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts.

  5. 75 FR 50926 - 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol, polyethylene...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... AGENCY 40 CFR Part 180 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol... tolerance for residues of 2-propenoic acid, 2-methyl-, C12-16- alkyl esters, telomers with 1-dodecanethiol... residues of 2-propenoic acid, 2-methyl-, C12-16-alkyl esters, telomers with 1-dodecanethiol,...

  6. 1-Ammonio-1-phosphono-pentane-1-phospho-nic acid.

    PubMed

    Bon, V V; Dudko, A V; Kozachkova, A N; Pekhnyo, V I

    2008-11-26

    The title compound, C(5)H(15)NO(6)P(2), was obtained by the reaction of penta-nenitrile with PCl(3) followed by the dropwise addition of water. The asymmetric unit contains one mol-ecule, which exists as a zwitterion with a positive charge on the -NH(3) group and a negative charge on one of the phospho-nic O atoms. The crystal structure displays N-H⋯O and O-H⋯O hydrogen bonding, which creates a three-dimensional network.

  7. Molecular dynamics simulations of phosphonic acid-aluminum oxide self-organization and their evolution into ordered monolayers.

    PubMed

    Dietrich, H; Schmaltz, T; Halik, M; Zahn, D

    2017-02-15

    We outline an unprejudiced molecular dynamics simulation approach to study the mechanisms of self-organization encompassing the evolution of surfactant-surface interactions to the growth of self-assembled monolayers (SAMs). Therein, the time-length scale problem is tackled by combining an efficient docking-type procedure for implementing surfactant-by-surfactant association with detailed molecular simulations to explore structural relaxation. For this, nanosecond-scale molecular dynamics simulations unravel ordering processes during the gradual assembly of the monolayer. Along this line, different packing motifs of octadecyl phosphonic acid (ODPA) on the (0001) surface of α-alumina and implications for the final density and ordering of the resulting monolayers are elucidated. Moreover, the role of the solvent is discriminated by comparing SAM formation in 2-propanol, hexane and in a vacuum.

  8. Influence of complexation phenomena with multivalent cations on the analysis of glyphosate and aminomethyl phosphonic acid in water.

    PubMed

    Freuze, Ingrid; Jadas-Hecart, Alain; Royer, Alain; Communal, Pierre-Yves

    2007-12-21

    Experimental and theoretical influence of multivalent cations on the analysis of glyphosate and aminomethyl phosphonic acid (AMPA) was studied in pure water and in one surface water. The procedure chosen, based on derivatization with FMOC-Cl, HPLC separation, and fluorescence detection, appears highly affected at cations concentrations current in natural waters. A detailed speciation study performed with the VMINTEQ software strongly suggests that the complexes formed between analytes and cations do not dissociate during the reaction and do not react with the derivatization agent, so that only the free forms are derivatized. These results point out the necessity of a pre-treatment to prevent these interferences, even in low salinity waters. The different ways conceivable are discussed in terms of kinetic and thermodynamic considerations.

  9. Low adhesion, non-wetting phosphonate self-assembled monolayer films formed on copper oxide surfaces.

    PubMed

    Hoque, E; DeRose, J A; Bhushan, B; Hipps, K W

    2009-07-01

    Self-assembled monolayer (SAM) films have been formed on oxidized copper (Cu) substrates by reaction with 1H,1H,2H,2H-perfluorodecylphosphonic acid (PFDP), octadecylphosphonic acid (ODP), decylphosphonic acid (DP), and octylphosphonic acid (OP) and then investigated by X-ray photoelectron spectroscopy (XPS), contact angle measurement (CAM), and atomic force microscopy (AFM). The presence of alkyl phosphonate molecules, PFDP, ODP, DP, and OP, on Cu were confirmed by CAM and XPS analysis. No alkyl phosphonate molecules were seen by XPS on unmodified Cu as a control. The PFDP/Cu and ODP/Cu SAMs were found to be very hydrophobic having water sessile drop static contact angles of more than 140 degrees , while DP/Cu and OP/Cu have contact angles of 119 degrees and 76 degrees , respectively. PFDP/Cu, ODP/Cu, DP/Cu, and OP/Cu SAMs were studied by friction force microscopy, a derivative of AFM, to better understand their micro/nanotribological properties. PFDP/Cu, ODP/Cu, and DP/Cu had comparable adhesive force, which is much lower than that for unmodified Cu. ODP/Cu had the lowest friction coefficient followed by PFDP/Cu, DP/Cu, and OP/Cu while unmodified Cu had the highest. XPS data gives some indication that a bidentate bond forms between the alkyl phosphonate molecules and the oxidized Cu surface. Hydrophobic phosphonate SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for anti-wetting, low adhesion surfaces.

  10. Alkylation by propylene oxide of deoxyribonucleic acid, adenine, guanosine and deoxyguanylic acid

    PubMed Central

    Lawley, P. D.; Jarman, M.

    1972-01-01

    1. Propylene oxide reacts with DNA in aqueous buffer solution at about neutral pH to yield two principal products, identified as 7-(2-hydroxypropyl)guanine and 3-(2-hydroxypropyl)adenine, which hydrolyse out of the alkylated DNA at neutral pH values at 37°C. 2. These products were obtained in quantity by reactions between propylene oxide and guanosine or adenine respectively. 3. The reactions between propylene oxide and adenine in acetic acid were parallel to those between dimethyl sulphate and adenine in neutral aqueous solution; the alkylated positions in adenine in order of decreasing reactivity were N-3, N-1 and N-9. A method for separating these alkyladenines is described. 4. Deoxyguanylic acid sodium salt was alkylated at N-7 by propylene oxide in neutral aqueous solution. 5. The nature of the side chain in the principal alkylation products was established by mass spectrometry, and the nature of the products is consistent with their formation by the bimolecular reaction mechanism. PMID:5073240

  11. Fatty acid alkyl esters: perspectives for production of alternative biofuels.

    PubMed

    Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

    2010-02-01

    The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis.

  12. Diarmed (adamantyl/alkyl) surfactants from nitrilotriacetic acid.

    PubMed

    Trillo, Juan V; Vázquez Tato, José; Jover, Aida; de Frutos, Santiago; Soto, Victor H; Galantini, Luciano; Meijide, Francisco

    2014-11-01

    The compounds presented here constitute a clear example of molecular biomimetics as their design is inspired on the structure and properties of natural phospholipids. Thus novel double-armed surfactants have been obtained in which nitrilotriacetic acid plays the role of glycerol in phospholipids. The hydrophobic arms are linked to the head group through amide bonds (which is also the case of sphingomyelin): (R1NHCOCH2)(R2NHCOCH2)NCH2CO2H (R1 being CH3(CH2)11, CH3(CH2)17, CH3(CH2)7CHCH(CH2)8, and adamantyl, and R2=adamantyl). The dependence of the surface tension with concentration shows the typical profile of surfactants since a breaking point, which corresponds to the critical aggregation concentration (cac), is observed in all cases. The cac of these diarmed derivatives are about 1-3 orders of magnitude lower than those of classical monoalkyl derivatives used as reference compounds. In contrast to conventional surfactants, reversed trends in cac values and molecular areas at the solution-air interface have been observed. This anomalous behavior is tied to the structure of the surfactants and suggests that long and flexible alkyl chains should self-coil previous to the aggregation or adsorption phenomena. Above cac all compounds form large aggregates, globular in shape, which tend to associate forming giant aggregates.

  13. Improve the Strength of PLA/HA Composite Through the Use of Surface Initiated Polymerization and Phosphonic Acid Coupling Agent

    PubMed Central

    Wang, Tongxin; Chow, Laurence C.; Frukhtbeyn, Stanislav A.; Ting, Andy Hai; Dong, Quanxiao; Yang, Mingshu; Mitchell, James W.

    2011-01-01

    Bioresorbable composite made from degradable polymers, e.g., polylactide (PLA), and bioactive calcium phosphates, e.g., hydroxyapatite (HA), are clinically desirable for bone fixation, repair and tissue engineering because they do not need to be removed by surgery after the bone heals. However, preparation of PLA/HA composite from non-modified HA usually results in mechanical strength reductions due to a weak interface between PLA and HA. In this study, a calcium-phosphate/phosphonate hybrid shell was developed to introduce a greater amount of reactive hydroxyl groups onto the HA particles. Then, PLA was successfully grafted on HA by surface-initiated polymerization through the non-ionic surface hydroxyl groups. Thermogravimetric analysis indiated that the amount of grafted PLA on HA can be up to 7 %, which is about 50 % greater than that from the literature. PLA grafted HA shows significantly different pH dependent ζ-potential and particle size profiles from those of uncoated HA. By combining the phosphonic acid coupling agent and surface initiated polymerization, PLA could directly link to HA through covalent bond so that the interfacial interaction in the PLA/HA composite can be significantly improved. The diametral tensile strength of PLA/HA composite prepared from PLA-grafted HA was found to be over twice that of the composite prepared from the non-modified HA. Moreover, the tensile strength of the improved composite was 23 % higher than that of PLA alone. By varying additional variables, this approach has the potential to produce bioresorbable composites with improved mechanical properties that are in the range of natural bones, and can have wide applications for bone fixation and repair in load-bearing areas. PMID:22399838

  14. Metal salts of alkyl catechol dithiophosphoric acids and oil compositions containing the salts

    SciTech Connect

    Yamaguchi, E.S.; Liston, T.V.

    1988-03-08

    Metal salts of alkyl catechol esters of dithiophosphoric acid suitable as additives in oil compositions are disclosed in this patent. Oil compositions containing the salts of such esters show improved extreme pressure/anti-wear and anit-oxidant properties.

  15. Comparative Oxidative Stability of Fatty Acid Alkyl Esters by Accelerated Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several fatty acid alkyl esters were subjected to accelerated methods of oxidation, including EN 14112 (Rancimat method) and pressurized differential scanning calorimetry (PDSC). Structural trends elucidated from both methods that improved oxidative stability included decreasing the number of doubl...

  16. Analysis of Phosphonic Acids: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS999

    SciTech Connect

    Owens, J; Vu, A; Koester, C

    2008-10-31

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled Analysis of Diisopropyl Methylphosphonate, Ethyl Hydrogen Dimethylamidophosphate, Isopropyl Methylphosphonic Acid, Methylphosphonic Acid, and Pinacolyl Methylphosphonic Acid in Water by Multiple Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry: EPA Version MS999. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in EPA Method MS999 for analysis of the listed phosphonic acids and surrogates in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of EPA Method MS999 can be determined.

  17. Oligonucleoside alkyl or arylphosphonate derivatives capable of crosslinking with or cleaving nucleic acids

    DOEpatents

    Miller, Paul S.; Ts'o, Paul O.P.

    1999-06-15

    A composition for inactivating a target nucleic acid which comprises an oligonucleoside alkyl or arylphosphonate analogue which is complementary to the sequence of the target nucleic acid and includes a functional group which reacts with the target nucleic acid to render the target nucleic acid inactive or nonfunctional.

  18. Oligonucleoside alkyl or arylphosphonate derivatives capable of crosslinking with or cleaving nucleic acids

    DOEpatents

    Miller, P.S.; Ts'o, P.O.P.

    1999-06-15

    A composition for inactivating a target nucleic acid which comprises an oligonucleoside alkyl or arylphosphonate analogue which is complementary to the sequence of the target nucleic acid is provided. It includes a functional group which reacts with the target nucleic acid to render the target nucleic acid inactive or nonfunctional. 16 figs.

  19. Bioavailability and bioconcentration potential of perfluoroalkyl-phosphinic and -phosphonic acids in zebrafish (Danio rerio): Comparison to perfluorocarboxylates and perfluorosulfonates.

    PubMed

    Chen, Fangfang; Gong, Zhiyuan; Kelly, Barry C

    2016-10-15

    Currently, information regarding bioavailability and bioconcentration potential of perfluoroalkyl phosphinic acids (PFPiAs) in aquatic organisms does not exist. The main objective of the present study was to assess uptake and elimination kinetics of PFPiAs in zebrafish (Danio rerio) following aqueous exposure. The results showed that PFPiA exposure can result in very high steady-state bioconentration factors (BCFss), compared to perfluorocarboxylates and perfluorosulfonates.C6/C10 PFPiA exhibited the highest BCFss, ranging between 10(7) and 10(10), orders of magnitude higher than those for long-chain perfluorocarboxylates. Strong positive relationships were observed between BCFss versus the membrane-water distribution coefficient (Dmw) and the protein-water partition coefficient (Kpw) of the studied perfluoroalkyl substances. However, BCFss exhibited a substantial drop for the very hydrophobic PFPiAs (C8/C10 and C6/C12 PFPiAs). The reduced BCFss of these long-chain PFPiAs (perfluoroalkyl chain length=18; Dmw=10(9)) is likely the result of reduced bioavailability due to interaction with solute molecules/organic matter present in the water phase and/or reduced gill membrane permeability. While PFPiAs can be metabolized to perfluoroalkyl phosphonic acids, the metabolic transformation rate seems insufficient to counteract the high degree of uptake across gill membranes. These findings help to better understand exposure pathways and bioaccumulation behavior of these important perfluorinated acids in aquatic systems.

  20. Isolation and identification of products from alkylation of nucleic acids: ethyl- and isopropyl-purines.

    PubMed Central

    Lawley, P D; Orr, D J; Jarman, M

    1975-01-01

    Ethylation and isopropylation of guanine in alkaline solution, or of adenine in formic acid, by alkyl methanesulphonates gave the following products: 1-, N2-, 3-, O6-, 7- and 9-alkylguanines; 1-, 3-, 7- and 9-alkyladenines. The products were identified from their characteristic u.v-absorption spectra, by comparison with either known ethyladenines or with the corresponding known methyladenines, and were also characterized by mass spectrometry. Their chromatographic properties on paper, t.l.c. and various columns were determined. DNA was alkylated in neutral solution with 14C-labelled alkyl methanesulphonates and the ratios of the alkylpurines formed were obtained, and compared for alkylation by methyl, ethyl and isopropyl methanesulphonates and by N-methyl-N-nitrosourea. The extents of alkylation at O-6 of guanine relative to those at N-7 of guanine varied with the reactivity of the methylating agents according to the predictions of Swain & Scott (1953) relating nucleophilicity of the groups alkylated with the substrate constants of the alkylating agents. The relative extents of alkylation at N-3 of adenine did not follow this correlation. PMID:172066

  1. Hybrid porous tin(IV) phosphonate: an efficient catalyst for adipic acid synthesis and a very good adsorbent for CO2 uptake.

    PubMed

    Dutta, Arghya; Pramanik, Malay; Patra, Astam K; Nandi, Mahasweta; Uyama, Hiroshi; Bhaumik, Asim

    2012-07-07

    A new porous organic-inorganic hybrid tin phosphonate material has been synthesized hydrothermally, which shows a Brunauer-Emmett-Teller surface area of 723 m(2) g(-1) and it adsorbs 4.8 mmol g(-1) CO(2) at 273 K and 5 bar pressure. The material also shows remarkable catalytic activity in one-pot liquid phase oxidation of cyclohexanone to adipic acid under eco-friendly conditions.

  2. Americium(III) capture using phosphonic acid-functionalized silicas with different mesoporous morphologies: adsorption behavior study and mechanism investigation by EXAFS/XPS.

    PubMed

    Zhang, Wen; He, Xihong; Ye, Gang; Yi, Rong; Chen, Jing

    2014-06-17

    Efficient capture of highly toxic radionuclides with long half-lives such as Americium-241 is crucial to prevent radionuclides from diffusing into the biosphere. To reach this purpose, three different types of mesoporous silicas functionalized with phosphonic acid ligands (SBA-POH, MCM-POH, and BPMO-POH) were synthesized via a facile procedure. The structure, surface chemistry, and micromorphology of the materials were fully characterized by (31)P/(13)C/(29)Si MAS NMR, XPS, and XRD analysis. Efficient adsorption of Am(III) was realized with a fast rate to reach equilibrium (within 10 min). Influences including structural parameters and functionalization degree on the adsorption behavior were investigated. Slope analysis of the equilibrium data suggested that the coordination with Am(III) involved the exchange of three protons. Moreover, extended X-ray absorption fine structure (EXAFS) analysis, in combination with XPS survey, was employed for an in-depth probe into the binding mechanism by using Eu(III) as a simulant due to its similar coordination behavior and benign property. The results showed three phosphonic acid ligands were coordinated to Eu(III) in bidentate fashion, and Eu(P(O)O)3(H2O) species were formed with the Eu-O coordination number of 7. These phosphonic acid-functionalized mesoporous silicas should be promising for the treatment of Am-containing radioactive liquid waste.

  3. Synthesis and biological evaluation of a series of liver-selective phosphonic acid thyroid hormone receptor agonists and their prodrugs.

    PubMed

    Boyer, Serge H; Jiang, Hongjian; Jacintho, Jason D; Reddy, Mali Venkat; Li, Haiqing; Li, Wenyu; Godwin, Jennifer L; Schulz, William G; Cable, Edward E; Hou, Jinzhao; Wu, Rongrong; Fujitaki, James M; Hecker, Scott J; Erion, Mark D

    2008-11-27

    Phosphonic acid (PA) thyroid hormone receptor (TR) agonists were synthesized to exploit the poor distribution of PA-based drugs to extrahepatic tissues and thereby to improve the therapeutic index. Nine PAs showed excellent TR binding affinities (TRbeta(1), K(i) < 10 nM), and most of them demonstrated significant cholesterol lowering effects in a cholesterol-fed rat (CFR) model. Unlike the corresponding carboxylic acid analogue and T(3), PA 22c demonstrated liver-selective effects by inducing maximal mitochondrial glycerol-3-phosphate dehydrogenase activity in rat liver while having no effect in the heart. Because of the low oral bioavailability of PA 22c, a series of prodrugs was synthesized and screened for oral efficacy in the CFR assay. The liver-activated cyclic 1-(3-chlorophenyl)-1,3-propanyl prodrug (MB07811) showed potent lipid lowering activity in the CFR (ED(50) 0.4 mg/kg, po) and good oral bioavailability (40%, rat) and was selected for development for the treatment of hypercholesterolemia.

  4. Alkylation of phenol with polybutenes in the presence of benzenesulfonic acid

    SciTech Connect

    Belov, P.S.; Gulyaev, I.A.; Korenev, K.D.; Yakovlev, V.B.; Zakupra, V.A.

    1982-09-01

    The purpose of this work is to test benzenesulfonic acid (BSA) as a catalyst in the alkylation of phenol with polyisobutylene (PIB). This material is used as a catalyst in the production of technical C/sub 5/-C/sub 12/ tert-alkylphenol. Finds that the optimal compromise between acceleration of the reaction and the alkylate viscosity increase that limits the reaction rate is achieved at a temperature of about 105 C and a BSA/PIB mole ratio of 0.15. Recommends BSA as an effective replacement for boron fluoride, boron fluoride complexes, and other highly corrosive catalysts used in the alkylation of phenol with polybutenes.

  5. Quantitative Determination and Comparison of the Surface Binding of Phosphonic Acid, Carboxylic Acid, and Catechol Ligands on TiO2 Nanoparticles.

    PubMed

    Zeininger, Lukas; Portilla, Luis; Halik, Marcus; Hirsch, Andreas

    2016-09-12

    The adsorption, desorption, co-adsorption, and exchange behavior of phosphonic acid, carboxylic acid, and catechol derivatives on the surface of titanium oxide (anatase) nanoparticles are investigated. Thermogravimetric analysis provides a facile and fast-track quantitative determination of the wet-chemical monolayer adsorption constants and grafting densities of ten adsorbates, all under neutral pH conditions. This characterization protocol allows straightforward quantification of the relevant thermodynamic data of ligand adsorption and a comparison of ligand adsorption strengths. The reported procedure is proposed as a universal tool and it should be applicable to many other colloidal metal oxide materials. Moreover, the determined values for the adsorption constants and the monolayer grafting densities provide a toolbox for the assessment of the adsorbates' behavior in desorption, exchange, and co-adsorption equilibria. This versatile evaluation procedure will help to identify optimal monolayer-surface combinations and to evaluate critical parameters, such as monolayer robustness, ligand exchange rates, or targeted mixed assembly of functionalities.

  6. Investigation of vinyl phosphonic acid/hydroxylated α-Al 2O 3( 0 0 0 1 ) reaction enthalpies

    NASA Astrophysics Data System (ADS)

    Hector, L. G., Jr.; Opalka, S. M.; Nitowski, G. A.; Wieserman, L.; Siegel, D. J.; Yu, H.; Adams, J. B.

    2001-11-01

    The eleven ion vinyl phosphonic acid (VPA) molecule consists of a phosphorus ion that serves as a cationic anchor for two electron-rich functional groups, viz., a tripodal oxygen-rich base and vinyl hydrocarbon tail. Recent inelastic tunneling experiments have implied that VPA binds in a tridentate coordination though its base leaving the vinyl tail free to react with a resin in adhesive bonding applications. Using first-principles total energy calculations, the reaction enthalpies for bonding of a single VPA molecule to selected threefold sites on hydroxylated α-Al 2O 3(0 0 0 1) are investigated. Tridentate, bidentate and unidentate coordinations, both with and without liberated water molecules, are examined to determine if the tridentate coordination is favored over the others and the extent to which the VPA molecule is sensitive to surface site geometry. The electron localization function is used to examine the extent of covalent character between the P-O bonds that anchor the VPA fragment to the oxide surface. Some comments on the entropic contributions of the VPA and H 2O molecules to the binding energetics are offered, along with a discussion of the effects of H 2O placement on the oxide surface and aluminum alloying agents.

  7. Anhydrous proton-conducting electrolyte membranes based on hyperbranched polymer with phosphonic acid groups for high-temperature fuel cells

    NASA Astrophysics Data System (ADS)

    Itoh, Takahito; Hirai, Keita; Tamura, Masashi; Uno, Takahiro; Kubo, Masataka; Aihara, Yuichi

    The two different molecular weight hyperbranched polymers (HBP(L)-PA-Ac and HBP(H)-PA-Ac) with both phosphonic acid group as a functional group and acryloyl group as a cross-linker at the chain ends were successfully synthesized as a new thermally stable proton-conducting electrolyte. The cross-linked electrolyte membranes (CL-HBP-PA) were prepared by their thermal polymerizations using benzoyl peroxide and their ionic conductivities under dry condition and thermal properties were investigated. The ionic conductivities of the low molecular weight CL-HBP(L)-PA membrane and the high molecular weight CL-HBP(H)-PA membrane were found to be 1.2 × 10 -5 and 2.6 × 10 -6 S cm -1, respectively, at 150 °C under dry condition, and showed the Vogel-Tamman-Fulcher (VTF) type temperature dependence. Both membranes were thermally stable up to 300 °C, and they had suitable thermal stability as electrolyte membranes for the high-temperature fuel cells under dry condition. Fuel cell measurements using a single membrane electrode assembly cell with both cross-linked membranes were successfully performed.

  8. 40 CFR 721.10702 - Polyfluorinated alkyl thio polyacrylic acid-acrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... acid-acrylamide (generic). 721.10702 Section 721.10702 Protection of Environment ENVIRONMENTAL...-acrylamide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyfluorinated alkyl thio polyacrylic acid-acrylamide (PMN P-11-534)...

  9. Alkyl substituent effects on gas-phase acidities - The influence of hybridization.

    NASA Technical Reports Server (NTRS)

    Brauman, J. I.; Blair, L. K.

    1971-01-01

    Exploration of the effect on acidity of alkyl groups bonded to trigonal and digonal carbon. Some results on the relative acidities of toluene and p-xylene, and acetylene and substitute acetylenes, as determined by ion cyclotron resonance (icr) spectroscopy, are described. Some limitations of the CNDO/2 calculation method are discussed.

  10. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium from a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant to and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate, nonsaturated in uranium. The uranium is stripped from, the organic extractant into the stripping solution, and the resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  11. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium for a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate or hydroxide thereby stripping uranium from the organic extractant into the stripping solution. The resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  12. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  13. Reductive alkylation and sequential reductive alkylation-click chemistry for on-solid-support modification of pyrrolidinyl peptide nucleic acid.

    PubMed

    Ditmangklo, Boonsong; Boonlua, Chalothorn; Suparpprom, Chaturong; Vilaivan, Tirayut

    2013-04-17

    A methodology for the site-specific attachment of fluorophores to the backbone of pyrrolidinyl peptide nucleic acids (PNAs) with an α/β-backbone derived from D-prolyl-(1S,2S)-2-aminocyclopentanecarboxylic acid (acpcPNA) has been developed. The strategy involves a postsynthetic reductive alkylation of the aldehyde-containing labels onto the acpcPNA that was previously modified with (3R,4S)-3-aminopyrrolidine-4-carboxylic acid on the solid support. The reductive alkylation reaction is remarkably efficient and compatible with a range of reactive functional groups including Fmoc-protected amino, azide, and alkynes. This allows further attachment of readily accessible carboxyl-, alkyne-, or azide-containing labels via amide bond formation or Cu-catalyzed azide-alkyne cycloaddition (CuAAC, also known as click chemistry). The label attached in this way does not negatively affect the affinity and specificity of the pairing of the acpcPNA to its DNA target. Applications of this methodology in creating self-reporting pyrene- and thiazole orange-labeled acpcPNA probes that can yield a change in fluorescence in response to the presence of the correct DNA target have also been explored. A strong fluorescence enhancement was observed with thiazole orange-labeled acpcPNA in the presence of DNA. The specificity could be further improved by enzymatic digestion with S1 nuclease, providing a 9- to 60-fold fluorescence enhancement with fully complementary DNA and a less than 3.5-fold enhancement with mismatched DNA targets.

  14. Improvement of catalytic activity of Candida rugosa lipase in the presence of calix[4]arene bearing iminodicarboxylic/phosphonic acid complexes modified iron oxide nanoparticles.

    PubMed

    Ozyilmaz, Elif; Bayrakci, Mevlut; Yilmaz, Mustafa

    2016-04-01

    In the present study, iron oxide magnetite nanoparticles, prepared through a co-precipitation method, were coated with phosphonic acid or iminodicarboxylic acid derivatives of calix[4]arene to modulate their surfaces with different acidic groups. Candida rugosa lipase was then directly immobilized onto the modified nanoparticles through sol-gel encapsulation. The catalytic activities and enantioselectivities of the two encapsulated lipases in the hydrolysis reaction of (R/S)-naproxen methyl ester and (R/S)-2-phenoxypropionic acid methyl ester were assessed. The results showed that the activity and enantioselectivity of the lipase were improved when the lipase was encapsulated in the presence of calixarene-based additives; the encapsulated lipase with the phosphonic acid derivative of calix[4]arene had an excellent rate of enantioselectivity against the (R/S)-naproxen methyl and (R/S)-2-phenoxypropionic acid methyl esters, with E=350 and 246, respectively, compared to the free enzyme. The encapsulated lipases (Fe-Calix-N(COOH)) and (Fe-Calix-P) showed good loading ability and little loss of enzyme activity, and the stability of the catalyst was very good; they only lost 6-11% of the enzyme's activity after five batches.

  15. Discovery of the antibiotic phosacetamycin via a new mass spectrometry-based method for phosphonic acid detection.

    PubMed

    Evans, Bradley S; Zhao, Changming; Gao, Jiangtao; Evans, Courtney M; Ju, Kou-San; Doroghazi, James R; van der Donk, Wilfred A; Kelleher, Neil L; Metcalf, William W

    2013-05-17

    Naturally occurring phosphonates such as phosphinothricin (Glufosinate, a commercially used herbicide) and fosfomycin (Monurol, a clinically used antibiotic) have proved to be potent and useful biocides. Yet this class of natural products is still an under explored family of secondary metabolites. Discovery of the biosynthetic pathways responsible for the production of these compounds has been simplified by using gene based screening approaches, but detection and identification of the natural products the genes produce have been hampered by a lack of high-throughput methods for screening potential producers under various culture conditions. Here, we present an efficient mass-spectrometric method for the selective detection of natural products containing phosphonate and phosphinate functional groups. We have used this method to identify a new phosphonate metabolite, phosacetamycin, whose structure, biological activity, and biosynthetic gene cluster are reported.

  16. Discovery of the antibiotic phosacetamycin via a new mass spectrometry-based method for phosphonic acid detection

    PubMed Central

    Evans, Bradley S.; Zhao, Changming; Gao, Jiangtao; Evans, Courtney M.; Ju, Kou-San; Doroghazi, James R.; van der Donk, Wilfred A.; Kelleher, Neil L.; Metcalf, William W.

    2013-01-01

    Naturally occurring phosphonates such as phosphinothricin (Glufosinate, a commercially used herbicide) and fosfomycin (Monurol, a clinically used antibiotic) have proved to be potent and useful biocides. Yet this class of natural products is still an under explored family of secondary metabolites. Discovery of the biosynthetic pathways responsible for the production of these compounds has been simplified by using gene based screening approaches, but detection and identification of the natural products the genes produce has been hampered by a lack of high-throughput methods for screening potential producers under various culture conditions. Here we present an efficient mass-spectrometric method for the selective detection of natural products containing phosphonate and phosphinate functional groups. We have used this method to identify a new phosphonate metabolite, phosacetamycin, whose structure, biological activity, and biosynthetic gene cluster are reported. PMID:23474169

  17. Synthesis of Functionalized Dialkyl Ketones From Carboxylic Acid Derivatives and Alkyl Halides

    PubMed Central

    Wotal, Alexander C.; Weix, Daniel J.

    2012-01-01

    Unsymmetrical dialkyl ketones can be directly prepared by the nickel-catalyzed reductive coupling of carboxylic acid chlorides or (2-pyridyl)thioesters with alkyl iodides or benzylic chlorides. A wide variety of functional groups are tolerated by this process, including common nitrogen protecting groups and C-B bonds. Even hindered ketones flanked by tertiary and secondary centers can be formed. The mechanism is proposed to involve the reaction of a (L)Ni(alkyl)2 intermediate with the carboxylic acid derivative. PMID:22360350

  18. Epoxy Phosphonate Crosslinkers for Providing Flame Resistance to Cotton Textiles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new monomers (2-methyl-oxiranylmethyl)-phosphonic acid dimethyl ester (3) and [2-(dimethoxy-phosphorylmethyl)-oxyranylmethyl]-phosphonic acid dimethyl ester (6) were prepared and used with dicyandiamide (7) and citric acid (8) to impart flame resistance to cotton plain weave, twill, and 80:20-co...

  19. Safety assessment of xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes as used in cosmetics.

    PubMed

    Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Hill, Ronald; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2011-12-01

    Xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes used in cosmetics as surfactants, hydrotropes, were reviewed in this safety assessment. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Cosmetic Ingredient Review Expert Panel reviewed relevant animal and human data related to these ingredients. The panel concluded that xylene sulfonic acid and alkyl aryl sulfonate hydrotropes are safe as cosmetic ingredients in the present practices of use and concentrations as described in this safety assessment, when formulated to be nonirritating.

  20. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  1. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  2. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  3. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  4. 40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfuric acid, mono-C9-11-alkyl esters... Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  5. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

    PubMed

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

    2013-10-01

    Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

  6. Phosphonic acids aid composition adjustment in the synthesis of Cu2+ x Zn1- x SnSe4- y nanoparticles

    NASA Astrophysics Data System (ADS)

    Ibáñez, Maria; Berestok, Taisiia; Dobrozhan, Oleksandr; LaLonde, Aaron; Izquierdo-Roca, Victor; Shavel, Alexey; Pérez-Rodríguez, Alejandro; Snyder, G. Jeffrey; Cabot, Andreu

    2016-08-01

    The functional properties of quaternary I2-II-IV-VI4 nanomaterials, with potential interest in various technological fields, are highly sensitive to compositional variations, which is a challenging parameter to adjust. Here we demonstrate the presence of phosphonic acids to aid controlling the reactivity of the II element monomer to be incorporated in quaternary Cu2ZnSnSe4 nanoparticles and thus to provide a more reliable way to adjust the final nanoparticle metal ratios. Furthermore, we demonstrate the composition control in such multivalence nanoparticles to allow modifying charge carrier concentrations in nanomaterials produced from the assembly of these building blocks.

  7. DNA-damaging disinfection byproducts: alkylation mechanism of mutagenic mucohalic acids.

    PubMed

    Gómez-Bombarelli, Rafael; González-Pérez, Marina; Arenas-Valgañón, Jorge; Céspedes-Camacho, Isaac Fabián; Calle, Emilio; Casado, Julio

    2011-10-15

    Hydroxyhalofuranones form a group of genotoxic disinfection byproduct (DBP) of increasing interest. Among them, mucohalic acids (3,4-dihalo-5-hydroxyfuran-2(5H)-one, MXA) are known mutagens that react with nucleotides, affording etheno, oxaloetheno, and halopropenal derivatives. Mucohalic acids have also found use in organic synthesis due to their high functionalization. In this work, the alkylation kinetics of mucochloric and mucobromic acids with model nucleophiles aniline and NBP has been studied experimentally. Also, the alkylation mechanism of nucleosides by MXA has been studied in silico. The results described allow us to reach the following conclusions: (i) based on the kinetic and computational evidence obtained, a reaction mechanism was proposed, in which MXA react directly with amino groups in nucleotides, preferentially attacking the exocyclic amino groups over the endocyclic aromatic nitrogen atoms; (ii) the suggested mechanism is in agreement with both the product distribution observed experimentally and the mutational pattern of MXA; (iii) the limiting step in the alkylation reaction is addition to the carbonyl group, subsequent steps occurring rapidly; and (iv) mucoxyhalic acids, the hydrolysis products of MXA, play no role in the alkylation reaction by MXA.

  8. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with ethoxylated fatty alcohols. 721.6475 Section 721.6475 Protection of Environment ENVIRONMENTAL... ethoxylated fatty alcohols. (a) Chemical substance and significant new uses subject to reporting. (1) The... generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols (PMN...

  9. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with ethoxylated fatty alcohols. 721.6475 Section 721.6475 Protection of Environment ENVIRONMENTAL... ethoxylated fatty alcohols. (a) Chemical substance and significant new uses subject to reporting. (1) The... generically as alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols (PMN...

  10. Friedel-crafts alkylation of benzene by normal omega-chloroalkanoic acids and their methyl esters and nitriles

    SciTech Connect

    Zakharkin, L.I.; Anikina, E.V.

    1987-08-20

    In the Friedel-Crafts alkylation of benzene by normal 1-haloalkanes with three or more carbon atoms a mixture of phenylalkanes forms, due to isomerization of the alkyl chain and migration of a hydrogen atoms. Under analogous conditions the alkylation of benzene by omega-chloroalkanoic acids, Cl(CH/sub 2/)/sub n/COOH, and omega-bromoalkanonitriles proceeds with isomerization of the alkyl chain, but beginning only with 6-chlorohexanoic acid and 6-bromohexanonitrile. Such a difference in the behavior of these halogen derivatives has not received a convincing explanation, although the mechanism of Friedel-Crafts alkylation of benzene should be the same in the two cases. For a better understanding of this difference, this work presents a systematic study of benzene alkylation by 4-chlorobutyric, 5-chlorovaleric, 6-chlorohexanoic, and 7-chloroheptanoic acids and their methyl esters and nitriles, and by ..gamma..-butyro- and delta-valerolactones. The catalyst was crystalline AlCl/sub 3/ twice sublimed from Mg. For comparison, alkylation with the respective 1-chloroalkanes was carried out. In the alkylation of benzene by omega-chloroalkanoic acids Cl(CH/sub 2/)/sub n/COOH (where n = 3-6) and their methyl esters and nitriles, in the presence of AlCl/sub 3/, the degree of isomerization of the alkyl chain is less than with the corresponding 1-chloroalkanes, depending on the increase in electron acceptor activity in the sequence HOOC- > CH/sub 3/OCO- > CN-.

  11. Grafting of bifunctional phosphonic and carboxylic acids on Phynox: Impact of induction heating

    NASA Astrophysics Data System (ADS)

    Devillers, S.; Lanners, L.; Delhalle, J.; Mekhalif, Z.

    2011-05-01

    Phynox, a cobalt-chromium alloy, exhibits interesting mechanical properties making it a valuable material for a number of applications. However, its applications (especially biomedical ones) often require specific surface properties that can be imparted via suitable surface functionalizations. Based on Faraday's law of induction, induction heating is a widely used method to heat metallic substrates directly and contactless. The aim of this work is to compare the influence of induction heating and a conventional heating method on the functionalization of Phynox surfaces with bifunctional (6-phosphonohexanoic and 11-phosphoundecanoic acids) monolayers in order to create a platform for a large variety of post-grafting chemical reactions, e.g. with alcohols and amines, to modify and control the surface properties. In a first part, we assess the influence of the heating method on the interaction between the two terminal moieties of the 6-phosphonohexanoic and 11-phosphoundecanoic acids and the Phynox surface by studying the grafting of n-dodecylphosphonic acid and n-dodecanoic acid separately. The suitability of such bifunctional molecules for post-grafting chemical reactions has then been assessed by studying the post-grafting of a fluorinated alcohol by the Steglich esterification reaction between the carboxylic end of the grafted bifunctional molecules and the alcohol function of the post-grafted molecule. It has been shown that induction heating can lead to a much more selective adsorption of bifunctional molecules on the surface of Phynox, leaving a higher amount of free carboxylic acid functions to react during the second modification step.

  12. An organocatalytic domino Michael-alkylation reaction: highly enantioselective construction of spiro-cyclopentanoneoxindoles and tetronic acid scaffolds.

    PubMed

    Zhou, Jing; Wang, Qi-Lin; Peng, Lin; Tian, Fang; Xu, Xiao-Ying; Wang, Li-Xin

    2014-12-04

    A new organocatalytic asymmetric domino Michael-alkylation reaction of methyleneindolinones and γ-halogenated-β-ketoesters is described. A variety of spiro-cyclopentanoneoxindoles were obtained in high yields (up to 96%), good diastereoselectivities (up to 12 : 1 dr) and excellent enantioselectivities (up to >99% ee) via α-alkylation. Interestingly, O-alkylated products with tetronic acid motifs could be obtained by tuning the N-protecting groups on methyleneindolinones with excellent enantioselectivities (up to >99% ee).

  13. V-shaped crystalline structures of di-n-alkyl esters of phosphoric acid.

    PubMed

    Thünemann, Andreas F; Kurth, Dirk G; Beinhoff, Matthias; Bienert, Ralf; Schulz, Burkhard

    2006-06-20

    We prepared crystals of di-n-alkyl esters of phosphoric acid with chain lengths of n = 10, 12, 14, 16, and 18. These were characterized by single-crystal X-ray analysis and differential scanning calorimetry (DSC). It was found that the alkyl chains are in an extended all-trans conformation and aligned close to perpendicular, forming V-shaped molecules. This is in strong contrast to the typical arrangement of the alkyl chains of phospholipids where the two alkyl chains are arranged parallel in the same direction (e.g., tuning fork configuration in bilayers). Additionally, it was found that the arrangement of the V-shaped molecules of the di-n-alkyl esters in neighboring stacks of the lamellar crystals is antiparallel for short chain lengths (n = 10 and 12) and parallel for the longer (n = 14 and 16). DSC reveals that the melting of the crystals increases systematically with increasing chain lengths from 48 to 82 degrees C. The contribution of each methylene group to the melting enthalpy (70-133 kJ/mol) is independent of the chain length (3.9 kJ per mol CH2).

  14. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  15. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  16. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  17. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  18. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  19. Formulation of ascorbic acid microemulsions with alkyl polyglycosides.

    PubMed

    Pakpayat, N; Nielloud, F; Fortuné, R; Tourne-Peteilh, C; Villarreal, A; Grillo, I; Bataille, B

    2009-06-01

    Ascorbic acid microemulsions for topical application were developed. In this study, microemulsions were prepared using HLD (hydrophilic lipophilic deviation) concept to optimise the formulation. From this optimal formulation, the realisation of dilution ternary diagrams leads to obtain microemulsion zones. In addition, the effects of composition variable on the physicochemical characteristics of each system were investigated. After optimisation of the microemulsion systems, ascorbic acid was loaded in the formulations. Surface tension and small angle neutron scattering were used to characterise the surface properties and the structure of the microemulsions. Bicontinuous structure microemulsions were identified, and the influence of ascorbic acid localisation at the interface leading to modifications of the microemulsion structure was pointed out. The solubilisation of ascorbic acid, the stabilisation and in vitro transdermal penetration "Frantz cells" of ascorbic acid microemulsions were studied. Three different microemulsions were envisaged. The results confirmed that these microemulsion systems present a real interest for formulation and protection of ascorbic acid. Regarding their transcutaneous penetration behaviour, the different microemulsions studied could be useful for different topical applications. A major location of ascorbic acid found in the epidermis where the decomposition of melanin occurred indicates that microemulsion could be considered as a suitable carrier system for application of ascorbic acid as a whitening agent. In addition, a good passage of the drug in the dermis could be interesting for the relative oxygen matrix damage.

  20. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  1. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  2. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  3. Fate of malathion and a phosphonic acid in activated sludge with varying solids retention times.

    PubMed

    Janeczko, Allen K; Walters, Edward B; Schuldt, Steven J; Magnuson, Matthew L; Willison, Stuart A; Brown, Lisa M; Ruiz, Oscar N; Felker, Daniel L; Racz, LeeAnn

    2014-06-15

    This study examined the ability of activated sludge (AS) to sorb and biodegrade ethylmethylphosphonic acid (EMPA) and malathion, a degradation product and surrogate, respectively, for an organophosphate chemical warfare agent. Sorption equilibrium isotherm experiments indicate that sorption of EMPA and malathion to AS is negligible. EMPA at a concentration of 1 mg L(-1) degraded by approximately 30% with apparent first-order kinetics, possibly via co-metabolism from nitrification. Heterotrophic bacteria and abiotic mechanisms, however, are largely responsible for malathion degradation also with apparent first-order kinetics. EMPA did not inhibit chemical oxygen demand (COD) oxidation or nitrification activity, although malathion did appear to induce a stress response resulting in inhibition of COD oxidation. The study also included a 30-day experiment in which malathion, at a concentration of 5 mg L(-1), was repeatedly fed to AS in bench-scale sequencing batch reactors (SBRs) operating at different solids retention times (SRTs). Peak malathion concentrations occurred at day 4.5, with the longer SRTs yielding greater peak malathion concentrations. The AS reduced the malathion concentrations to nearly zero by day 10 for all SRTs, even when the malathion concentration in the influent increased to 20.8 mg L(-1). The data suggest a biodegradation pathway for malathion involving an oxygenase. Phylogenetic analyses revealed that all samples had an abundance of Zoogloea, though there was greater bacterial diversity in the SBR with the SRT of 50 days. The SBR with an SRT of 9.5 days had an apparent reduction in the diversity of the bacterial community.

  4. Alkyl protocatechuates as novel urinary biomarkers of exposure to p-hydroxybenzoic acid esters (parabens).

    PubMed

    Wang, Lei; Kannan, Kurunthachalam

    2013-09-01

    Human exposure to p-hydroxybenzoic acid esters (parabens) is a concern, owing to adverse health effects of these compounds. Parabens are metabolized and eliminated from the human bodies within a few hours of exposure. In this study, for the first time, methyl- and ethyl-protocatechuates (OH-MeP and OH-EtP) and their parent compounds, methyl- (MeP) and ethyl-parabens (EtP), were determined in urine samples collected from U.S. children and adults. Alkyl protocatechuates were found in almost all urine samples, with median concentrations of 11.8 (OH-MeP) and 2.90ng/mL (OH-EtP) in adults, and 5.43 (OH-MeP) and 0.85ng/mL (OH-EtP) in children. In adults, the concentrations of urinary OH-MeP and OH-EtP were higher than the corresponding concentrations of MeP and EtP. Significant correlation between OH-MeP/OH-EtP and MeP/EtP was observed. This is the first report to document hydroxylation of parabens in humans, and to propose hydroxylated metabolites (i.e., alkyl protocatechuates) as alternative biomarkers of exposure to parabens in human biomonitoring studies. The rates of transformation of parabens between children and adults appeared to be different, as evidenced from the slopes of regression between alkyl protocatechuates and parabens. In addition to alkyl protocatechuates, hydroxybenzoic acid (4-HB) and 3,4-dihydroxybenzoic acid (3,4-DHB) were found at considerable levels in the urine samples. The occurrence of a significant proportion of alkyl protocatechuates and 3,4-DHB suggests the need for inclusion of these derivatives in accurate estimation of human exposure to parabens and in epidemiological studies that associate paraben exposure to health outcomes in populations.

  5. Effective methylation of phosphonic acids related to chemical warfare agents mediated by trimethyloxonium tetrafluoroborate for their qualitative detection and identification by gas chromatography-mass spectrometry.

    PubMed

    Valdez, Carlos A; Leif, Roald N; Alcaraz, Armando

    2016-08-24

    The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found to be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (∼10 μg mL(-1)). Due to its insolubility in methylene chloride, TMO·BF4 conveniently settles to the bottom during the reaction and does not produce additional interfering by-products that may further complicate the GC-MS analysis. The method was demonstrated to successfully methylate a variety of Schedule 2 phosphonic acids, including their half esters, resulting in derivatives that were readily detected and identified using the instrument's spectral library. Most importantly, the method was shown to simultaneously methylate a mixture of the organophosphorus-based nerve agent hydrolysis products: pinacolyl methylphosphonate (PMPA), cyclohexyl methylphosphonate (CyMPA) and ethyl methylphosphonate (EMPA) (at a 10 μg mL(-1) concentration each) in a fatty acid ester-rich organic matrix (OPCW-PT-O3) featured in the 38th Organisation for the Prohibition of Chemical Weapons (OPCW) Proficiency Test. In addition, the protocol was found to effectively methylate N,N-diethylamino ethanesulfonic acid and N,N-diisopropylamino ethanesulfonic acid that are products arising from the oxidative degradation of the V-series agents VR and VX respectively. The

  6. Synthesis of 5-alkylated barbituric acids and 3-alkylated indoles via microwave-assisted three-component reactions in solvent-free conditions using Hantzsch 1,4-dihydropyridines as reducing agents.

    PubMed

    Baruah, Biswajita; Seetham Naidu, P; Borah, Pallabi; Bhuyan, Pulak J

    2012-05-01

    Reaction of barbituric acids with aldehydes and dihydropyridines in one pot under microwave (MW) irradiation in the absence of solvent, affords 55–82% of the 5-benzylated barbituric acids. Use of alkyl nitriles or barbituric acids with indole-3-aldehyde and dihydropyridine (DHP) afforded 3-alkylated indoles in 57–76 % yield. In each case DHPs are converted to pyridines.

  7. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural product dihydroferulic acid (DFA, 1) and the synthesized DFA methyl (4a), ethyl (4b), propyl (4c), hexyl (4d), octyl (4e), and decyl (4f) esters were examined for antifungal activity. Test fungi included Saccharomyces cerevisiae (wild type, and deletion mutants slt2delta and bck1delta), ...

  8. Fungicidal Activities of Dihydroferulic Acid Alkyl Ester Analogs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural product dihydroferulic acid (DFA, 1) and the synthesized DFA methyl (4a), ethyl (4b), propyl (4c), hexyl (4d), octyl (4e), and decyl (4f) esters were examined for antifungal activity. Test fungi included Saccharomyces cerevisiae (wild type, and deletion mutants slt2' and bck1'), Aspergil...

  9. Directing alkyl chain ordering of functional phosphorus coupling agents on ZrO2.

    PubMed

    Lomoschitz, Christoph J; Feichtenschlager, Bernhard; Moszner, Norbert; Puchberger, Michael; Müller, Klaus; Abele, Matthias; Kickelbick, Guido

    2011-04-05

    ZrO(2) powder (6.6 m(2)/g) was modified using polymerizable phosphorus-based coupling agents (P-CAs) (i.e., phosphonic acid, phosphoric acid, and bis-phosphonic acid), resulting in densely grafted layers as determined by thermogravimetry and elemental analysis (up to 4.2 molecules/nm(2)). The applied P-CAs contained a methacrylate group, which led to the covalent incorporation of a polymerizable moiety into the grafted layer. To direct the ordering of the alkyl chains in the layer, three different approaches were evaluated with respect to their structure-directing ability by means of FT-IR and nitrogen sorption at 77 K: (i) variation of the chain length, (ii) variation of the anchoring group and (iii) comodification with a defined amount of a nonfunctional phosphonic acid (variation of the functional/nonfunctional acid ratio). It was shown that the chain length and anchoring group size have significant effects on the alkyl chain ordering and morphology of the layer.

  10. Ignition Delays of Alkyl Thiophosphites with White and Red Fuming Nitric Acids Within Temperature Range 80 to -105 F

    NASA Technical Reports Server (NTRS)

    Miller, Riley O; Ladanyi, Dezso J

    1953-01-01

    Ignition delays of alkyl thiophosphites were obtained in a modified open-cup apparatus and a small-scale rocket engine apparatus. At -40 F, mixed alkyl thiophosphites gave short delays with white fuming nitric acid containing 2 percent water and red fuming nitric acids of widely varying compositions. At -40 F and higher, triethyl trithiophosphite blended with as much as 40 percent n-heptane gave satisfactory self-igniting properties at temperatures as low as -76 F.

  11. Effects of the addition of dimer acid alkyl esters on the properties of ethyl cellulose.

    PubMed

    Lee, Sangjun; Ko, Kwang-Hwan; Shin, Jihoon; Kim, Nam-Kyun; Kim, Young-Wun; Kim, Joon-Seop

    2015-05-05

    In this study, we synthesized dimer acid (DA) esters, having short to long alkyl chains, (DA-Cn) by the Diels-Alder reaction and subsequent esterification reaction of fatty acids that were prepared by the hydrolysis of waste vegetable oil. It was found that the DA-Cn were thermally more stable than common petroleum-based plasticizer DOP. When the DOP, DA, or DA-Cn with short alkyl chains were added to ethyl cellulose (EC), the optical clarity and SEM images of the samples showed their good miscibility with those additives in a micro-scale. It was also found that the rubbery modulus of the EC decreased with increasing amount of additives; the type of the additives did not affect the rates of the decrease in the rubbery modulus. The main transition temperatures of the EC containing either DA or DA-C1 or DA-C4 decreased with increasing amounts of those additives and were comparable to that of the DOP-containing EC. The above findings suggested that the DA and its esters with short alkyl chains could act as effective plasticizer and, thus, could be used instead of the DOP. In addition, the results obtained from tensile testing and leaching experiments implied that the DA might be better plasticizer than the DA-C1 and DA-C4, at least in some cases, because of hydrogen-bonding with the EC.

  12. Template-free synthesis of a porous organic-inorganic hybrid tin(IV) phosphonate and its high catalytic activity for esterification of free fatty acids.

    PubMed

    Dutta, Arghya; Patra, Astam K; Uyama, Hiroshi; Bhaumik, Asim

    2013-10-23

    Here we have synthesized an organic-inorganic hybrid mesoporous tin phosphonate monolith (MLSnP-1) with crystalline pore walls by a template-free sol-gel route. N2 sorption analysis shows Brunauer-Emmett-Teller (BET) surface area of 347 m2 g(-1). Wide-angle powder X-ray diffraction (PXRD) pattern shows few broad diffraction peaks indicating crystalline pore wall of the material. High-resolution transmission electron microscopic (HR TEM) image further reveals the crystal fringes on the pore wall. Framework bonding and local environment around phosphorus and carbon were examined by Fourier transform infrared (FT IR) spectroscopy and solid-state MAS NMR spectroscopy. The material exhibits remarkable catalytic activity for esterification of long chain fatty acids under mild reaction conditions at room temperature.

  13. Metallaphotoredox-catalysed sp3-sp3 cross-coupling of carboxylic acids with alkyl halides

    NASA Astrophysics Data System (ADS)

    Johnston, Craig P.; Smith, Russell T.; Allmendinger, Simon; MacMillan, David W. C.

    2016-08-01

    In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp3-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp2-hybridized species, the development of methods for sp3-sp3 bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp3-sp3 bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step- and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp3-sp3 coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp3-sp3 bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox protocol is suitable for

  14. Raman Scattering Sensor for Control of the Acid Alkylation Process in Gasoline Production

    SciTech Connect

    Uibel, Rory, H.; Smith, Lee M.; Benner, Robert, E.

    2006-04-19

    Gasoline refineries utilize a process called acid alkylation to increase the octane rating of blended gasoline, and this is the single most expensive process in the refinery. For process efficiency and safety reasons, the sulfuric acid can only be used while it is in the concentration range of 98 to 86 %. The conventional technique to monitor the acid concentration is time consuming and is typically conducted only a few times per day. This results in running higher acid concentrations than they would like to ensure that the process proceeds uninterrupted. Maintaining an excessively high acid concentration costs the refineries millions of dollars each year. Using SBIR funding, Process Instruments Inc. has developed an inline sensor for real time monitoring of acid concentrations in gasoline refinery alkylation units. Real time data was then collected over time from the instrument and its responses were matched up with the laboratory analysis. A model was then developed to correlate the laboratory acid values to the Raman signal that is transmitted back to the instrument from the process stream. The instrument was then used to demonstrate that it could create real-time predictions of the acid concentrations. The results from this test showed that the instrument could accurately predict the acid concentrations to within ~0.15% acid strength, and this level of prediction proved to be similar or better then the laboratory analysis. By utilizing a sensor for process monitoring the most economic acid concentrations can be maintained. A single smaller refinery (50,000 barrels/day) estimates that they should save over $120,000/year, with larger refineries saving considerably more.

  15. Palladium-Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite.

    PubMed

    Shavnya, Andre; Hesp, Kevin D; Mascitti, Vincent; Smith, Aaron C

    2015-11-09

    A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.

  16. Scope and limitations of aliphatic Friedel-Crafts alkylations. Lewis acid catalyzed addition reactions of alkyl chlorides to carbon-carbon double bonds

    SciTech Connect

    Mayr, H.; Striepe, W.

    1983-04-22

    Lewis acid catalyzed addition reactions of alkyl halides with unsaturated hydrocarbons have been studied. 1:1 addition products are formed if the addends dissociate faster than the corresponding products; otherwise, polymerization takes place. For reaction conditions under which these compounds exist mainly undissociated, solvolysis constants of model compounds can be used to predict the outcome of any such addition reactions if systems with considerable steric hindrance are excluded.

  17. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  18. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  19. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., C12-18 alkyl esters (generic). 721.3025 Section 721.3025 Protection of Environment ENVIRONMENTAL... alkyl esters (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  20. Hyaluronic acid alkyl derivative: A novel inhibitor of metalloproteases and hyaluronidases.

    PubMed

    Pavan, Mauro; Galesso, Devis; Secchieri, Cynthia; Guarise, Cristian

    2016-03-01

    Extracellular matrix (ECM) degradation, one of the main features of osteoarthritis, is driven by at least two major classes of enzymes: matrix metalloproteases (MMPs) and hyaluronidases. Among certain glycosaminoglycans, including natural and chemically cross-linked HAs, which are currently used as viscosupplements, the hyaluronic acid (HA) alkyl-amides (Hyadd) were here selected as the strongest MMP and hyaluronidase inhibitors. We used C. histolyticum collagenase (ChC) and bovine testicular hyaluronidase (BTH) as representative models of human MMPs and hyaluronidases, respectively. The role of the alkyl moiety was investigated using HA derivatives with varying alkyl lengths and degrees of derivatization. The selected compound was then screened against 10 different human MMPs in vitro, and the results were validated ex vivo in human synovial fluid. Hyadd-C16, identified as a lead compound, showed the highest inhibition potency against MMP13 and MMP8. The in vitro results were confirmed by the inhibition of human MMP13 (Ki=106.1 μM) and hyaluronidase-2 in the synovial fluid of patients with osteoarthritis. This study demonstrates the unique properties of Hyadd-C16, including its remarkable enzymatic inhibitory activity, which is conferred by the hydrophobic chain, and its high biocompatibility and water solubility of the HA backbone.

  1. DEGRADATION OF NITRILOTRIS (METHYLENEPHOSPHONIC ACID) AND RELATED (AMINO) PHOSPHONATE CHELATING AGENTS IN THE PRESENCE OF MANGANESE AND MOLECULAR OXYGEN. (R826376)

    EPA Science Inventory

    Phosphonates are used in an increasing variety of industrial and household
    applications including cooling waters systems, oil production, textile industry,
    and detergents. Phosphonates are not biodegraded during wastewater treatment but
    instead are removed by adsor...

  2. Effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying evaluated using a non-invasive breath test in conscious rats

    PubMed Central

    Uchida, Masayuki; Kobayashi, Orie; Iwasawa, Kaori; Shimizu, Kimiko

    2016-01-01

    Aim: Some amino acids been known to influence gastric emptying. Thus we have evaluated the effects of straight alkyl chain, extra hydroxylated alkyl chain and branched chain amino acids on gastric emptying. Materials and Methods: Gastric emptying was evaluated in rats after feeding with Racol (nutrient formulae) containing [1-13C] acetic acid. Using a breath test, the content of 13CO2 in their expired air was measured by infrared analyzers. Rats were orally administered with test amino acids, while control rats were administered orally with distilled water. Results: The expired 13CO2 content in the expired air increased with time, peaked after about 30 min and decreased thereafter. Among the amino acids having an alkyl chain, l-serine, l-alanine and l-glycine, significantly decreased the 13CO2 content and Cmax, and delayed Tmax, suggesting inhibition and delay of gastric emptying. AUC120 min values of l-alanine and l-glycine also decreased significantly. l-Threonine significantly decreased 13CO2 content and delayed Tmax, but had no influence on Cmax and AUC120 min values, suggesting a delay of gastric emptying. l-Isoleucine and l-leucine and l-valine significantly decreased 13CO2 content, suggesting inhibition of the gastric emptying, but Cmax, Tmax and AUC120 min values were not significantly affected. Conclusion: The results show that the amino acids used in the present study had different effects on gastric emptying. Moreover, it was found that inhibition and delay of gastric emptying were clearly classifiable by analyzing the change in 13CO2 content of the expired air and the Cmax, Tmax and AUC120 min values. PMID:27169776

  3. Application of Supercritical Fluids to Solid Acid Catalyst Alkylation and Regeneration

    SciTech Connect

    Lucia M. Petkovic; Daniel M. Ginosar; David N. Thompson; Kyle C. Burch

    2007-05-01

    Supercritical fluid (SCF) regeneration is a promising alternative method for regenerating solid catalysts deactivated by carbonaceous deposits. The unique solvent and transport properties of SCFs such as solvent strength similar to liquids and transport properties similar to gases make them highly suitable for extraction of fouling materials from porous heterogeneous catalysts. A brief review of the research work performed at the Idaho National Laboratory (INL) on the application of supercritical fluids to both isobutane/butene alkylation reaction and solid acid catalyst regeneration is presented in this contribution.

  4. Virucidal effects of bleach activators, sodium alkyl acyloxybenzene sulfonate and acyloxybenzoic acid, against Feline calicivirus.

    PubMed

    Tobe, Seiichi; Hoshi, Marika; Iizuka, Kinue; Tadenuma, Hirohiko; Takaoka, Hiromitsu; Komoriya, Tomoe; Kohno, Hideki

    2012-01-01

    Noroviruses (NVs) are major causative pathogens of gastroenteritis. The disinfection of contaminated clothing during common household washing is desirable. The virucidal effects of 2 bleach activators, sodium alkyl acyloxybenzene sulfonate (OBS) and alkyl acyloxybenzoic acid (OBC), were studied using Feline calicivirus (FCV) as a surrogate for NVs. FCV was added to solutions containing either OBS or OBC and sodium percarbonate at various temperatures and for varying lengths of time. OBS and OBC, which generate long carbon chain peroxy acids, enhanced the virucidal effect of sodium percarbonate (PC). In particular, sodium lauroyloxybenzene sulfonate (OBS-12) and decanoyloxybenzoic acid (OBC-10) showed superior virucidal effects. Although the virucidal effect of 38-200 mg/L OBS-12 was maintained with 2-5% (v/v) horse serum, there was less of an effect with the same concentration of available chlorine. OBS and OBC have been used as ingredients in some laundry products to increase bleaching activity. It is expected that the use of OBS and OBC is also effective for the inactivation of NVs under common household washing conditions.

  5. Phosphonated chelates for nuclear imaging.

    PubMed

    Abada, Sabah; Lecointre, Alexandre; Christine, Câline; Ehret-Sabatier, Laurence; Saupe, Falk; Orend, Gertraud; Brasse, David; Ouadi, Ali; Hussenet, Thomas; Laquerrière, Patrice; Elhabiri, Mourad; Charbonnière, Loïc J

    2014-12-21

    A series of bis-, tris- and tetra-phosphonated pyridine ligands is presented. In view of their potential use as chelates for radiopharmaceutical applications, the physico-chemical properties of the ligands and of their Co(II), Ni(II), Cu(II), and Zn(II) complexes were studied by means of potentiometry and UV-Vis absorption spectroscopy. The pKa values of the ligands and of the complexes, as well as the stability constants for the formation of the complexes, are presented. The kinetic aspects of the formation of Cu(II) complexes and of their dissociation in acidic media were studied by means of stopped flow experiments, and the stability of the Cu(II) complex toward reduction to Cu(I) was investigated by cyclic voltammetry and by titration with different reducing agents. The different thermodynamic and kinetic aspects of the polyphosphonated ligands were compared with regard to the impact of the number of phosphonic acid functions. Considering the very promising properties for complexation, preliminary SPECT/CT imaging experiments were carried out on mice with (99m)Tc using the bis- and tetra-phosphonated ligands L(2) and L(1). Finally, a bifunctional version of chelate L(1), L*, was used to label MTn12, a rat monoclonal antibody with both specificity and relatively high affinity for murine tenascin-C. The labeling was monitored by MALDI/MS spectrometry and the affinity of the labeled antibody was checked by immunostaining experiments. After chelation with (99m)Tc, the (99m)Tc-L*-MTn12 antibody was injected into a transgenic mouse with breast cancer and the biodistribution of the labeled antibody was followed by SPECT/CT imaging.

  6. Actinide phosphonate complexes in aqueous solutions

    SciTech Connect

    Nash, K.L.

    1993-10-01

    Complexes formed by actinides with carboxylic acids, polycarboxylic acids, and aminopolycarboxylic acids play a central role in both the basic and process chemistry of the actinides. Recent studies of f-element complexes with phosphonic acid ligands indicate that new ligands incorporating doubly ionizable phosphonate groups (-PO{sub 3}H{sub 2}) have many properties which are unique chemically, and promise more efficient separation processes for waste cleanup and environmental restoration. Simple diphosphonate ligands form much stronger complexes than isostructural carboxylates, often exhibiting higher solubility as well. In this manuscript recent studies of the thermodynamics and kinetics of f-element complexation by 1,1 and 1,2 diphosphonic acid ligands are described.

  7. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  8. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  9. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  10. 40 CFR 721.10218 - 2-Propenoic acid, 2-mehtyl-, C12-15-branched and linear alkyl esters, telomers with alkyl 2...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-branched and linear alkyl esters, telomers with alkyl 2- thio]-2-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated (generic). 721.10218 Section 721.10218...-alkanoate, aminoalkyl methacrylate and alkyl methacrylate, tert-Bu 2-ethylhexanoperoxoate-initiated...

  11. Poly(arlyene ether sulfone) based semi-interpenetrating polymer network membranes containing cross-linked poly(vinyl phosphonic acid) chains for fuel cell applications at high temperature and low humidity conditions

    NASA Astrophysics Data System (ADS)

    Kim, Kihyun; Heo, Pilwon; Ko, Taeyun; Kim, Ki-hyun; Kim, Sung-Kon; Pak, Chanho; Lee, Jong-Chan

    2015-10-01

    Semi-interpenetrating polymer network (semi-IPN) membranes are prepared by in-situ casting and thermal-initiated radical polymerization of vinyl phosphonic acid (VPA) and bis(2-(methacryloyloxy)ethyl) phosphate (BMAEP) in N,N-dimethylacetamide solutions of sulfonated poly(arylene ether sulfone) (SPAES). The incorporation of VPA units into the SPAES membranes improves proton conductivity especially at high temperature and low humidity conditions. In addition the cross-linker, BMAEP, prevents the decrease of the mechanical and chemical stabilities by the aliphatic linear poly(vinyl phosphonic acid) chains in the semi-IPN membranes, and furthermore the phosphonic acid group in BMAEP can prevent the decrease of the proton conductivity by the formation of cross-linked structures. Therefore, the resulting semi-IPN membranes show high proton conductivities up to 15 mS cm-1 at 120 °C and 40% RH. The fuel cell performance (187 mW cm-2 at 120 °C and 40% RH) of membrane-electrode assembly (MEA) from the semi-IPN membrane is found to be superior to that (145 mW cm-2 at 120 °C and 40% RH) of MEA from the SPAES membrane. The durability test result at the operating conditions indicates that the semi-IPN membrane is electrochemically very stable maintaining the low hydrogen cross-over and high power densities.

  12. Induction of mitochondrial fusion by cysteine-alkylators ethacrynic acid and N-ethylmaleimide.

    PubMed

    Bowes, Timothy J; Gupta, Radhey S

    2005-03-01

    Mitochondrial fusion and fission are important aspects of eukaryotic cell function that permit the adoption of varied mitochondrial morphologies depending upon cellular physiology. We previously observed that ethacrynic acid (EA) induced mitochondrial fusion in cultured BSC-1 and CHO/wt cells. However, the mechanism responsible for it was not clear since EA has a number of known cellular effects including glutathione (GSH) depletion and alkylation of cysteine residues. To gain insight, we have tested the effects of a variety of compounds on EA induced cellular toxicity and mitochondrial fusion. N-acetyl cysteine (NAC), a GSH precursor, was found to abrogate both the toxic and fusion-inductive effects, whereas diethylmaleate (dEM), a GSH depletor, potentiated both these effects in a dose-dependent manner. However, treatment with dEM alone, which depleted GSH to the same degree as EA, did not induce mitochondrial fusion. These results indicate that although detoxification of EA via formation of GSH conjugates is dependant upon GSH levels, the depletion of GSH by EA is not responsible for its effect on mitochondrial fusion. Dihydro-EA (DH-EA), a saturated EA analogue, lacked EA's toxicity and effect on fusion, indicating that the alpha,beta-unsaturated ketone is central to its observed effects. N-ethylmaleimide (NEM), another well-known cysteine-alkylator, also induced mitochondrial fusion at near toxic concentrations. These data suggests that cysteine-alkylation is the causative factor for fusion and toxicity. In live BSC-1 cells, EA induced fusion of mitochondria occurred very rapidly (<20 min), which suggests that it is inducing fusion by modifying certain critical cysteine residue(s) in proteins involved in the process.

  13. Diametric Stereocontrol in Dynamic Catalytic Reduction of Racemic Acyl Phosphonates: Divergence from α-Keto Ester Congeners

    PubMed Central

    Corbett, Michael T.; Johnson, Jeffrey S.

    2013-01-01

    An unexpected dichotomy was observed in the Ru-catalyzed asymmetric transfer hydrogenation of acyl phosphonates: reduction proceeded from the opposite face relative to that observed in the analogous reduction of α-keto esters. The first highly selective catalytic hydrogenation of acyl phosphonates was utilized in the dynamic kinetic resolution of α-aryl acyl phosphonates providing β-stereogenic α-hydroxy phosphonic acid derivatives. PMID:23297694

  14. Biodistribution and pharmacokinetics of variously sized molecular radiolabelled polyethyleneiminomethyl phosphonic acid as a selective bone seeker for therapy in the normal primate model.

    PubMed

    Dormehl, I C; Louw, W K; Milner, R J; Kilian, E; Schneeweiss, F H

    2001-01-01

    An ideal radiopharmaceutical for the treatment of neoplastic and inflammatory (benign) bone disease would be a radiolabelled compound that predominantly accumulates in bone lesions with limited access to normal bone and other organs. Neoplastic tissue's abnormal blood supply (increased permeability) and lack of lymphatics will selectively accumulate radiolabelled macromolecules. This enhanced permeability and retention effect forms the basis of this study, using various molecular sizes of the radiolabelled macromolecule polyethyleneiminomethyl phosphonic acid (PEI-MP) for increased selectivity of the bone-seeking radiopharmaceutical. PEI-MP was synthesized by condensation of polyethyleneimine, phosphonic acid and formaldehyde, followed by fractionation into different molecular sizes by membrane ultrafiltration. Labelling efficiency to 99mTc (as radiotracer) was approximately 99% with complexes stable for 24 h. The pharmacokinetics and biodistribution of various 99mTc-PEI-MP fractions were investigated using 4 experimental baboons (Papio ursinus) per fraction. Scintigraphy was performed on the baboons under general anaesthesia of pentobarbital i.v. After an i.v. bolus of 99mTc-PEI-MP (approximately 185 MBq) both dynamic studies (30 x 1 min frames), and static studies (2 min acquisition every hour for 4 h) were done, as well as blood samples and urine collected. From the results macromolecules with sizes ranging between 30-300 kDa were characterized by excessive liver (21%-57% retained activity) and kidney (40% retained activity) uptake and accompanying long residing times (t1/2 up to 24 h). The percentage bone uptake averaged at 8% for these particles excluding sizes 100-300 kDa where very little bone uptake was seen (< 1%). In this case the blood clearance was also slow (t1/2 approximately 2 h). The fraction size 10-30 kDa had comparatively low accumulation and short residence times in the liver and kidneys (resp. 20%, t1/2 = 22 +/- 4 min; 17.5%, t1/2 = 20 +/- 3

  15. Microbial biodegradation of aromatic alkanoic naphthenic acids is affected by the degree of alkyl side chain branching

    PubMed Central

    Johnson, Richard J; Smith, Ben E; Sutton, Paul A; McGenity, Terry J; Rowland, Steven J; Whitby, Corinne

    2011-01-01

    Naphthenic acids (NAs) occur naturally in oil sands and enter the environment through natural and anthropogenic processes. NAs comprise toxic carboxylic acids that are difficult to degrade. Information on NA biodegradation mechanisms is limited, and there are no studies on alkyl branched aromatic alkanoic acid biodegradation, despite their contribution to NA toxicity and recalcitrance. Increased alkyl side chain branching has been proposed to explain NA recalcitrance. Using soil enrichments, we examined the biodegradation of four aromatic alkanoic acid isomers that differed in alkyl side chain branching: (4′-n-butylphenyl)-4-butanoic acid (n-BPBA, least branched); (4′-iso-butylphenyl)-4-butanoic acid (iso-BPBA); (4′-sec-butylphenyl)-4-butanoic acid (sec-BPBA) and (4′-tert-butylphenyl)-4-butanoic acid (tert-BPBA, most branched). n-BPBA was completely metabolized within 49 days. Mass spectral analysis confirmed that the more branched isomers iso-, sec- and tert-BPBA were transformed to their butylphenylethanoic acid (BPEA) counterparts at 14 days. The BPEA metabolites were generally less toxic than BPBAs as determined by Microtox assay. n-BPEA was further transformed to a diacid, showing that carboxylation of the alkyl side chain occurred. In each case, biodegradation of the carboxyl side chain proceeded through beta-oxidation, which depended on the degree of alkyl side chain branching, and a BPBA degradation pathway is proposed. Comparison of 16S rRNA gene sequences at days 0 and 49 showed an increase and high abundance at day 49 of Pseudomonas (sec-BPBA), Burkholderia (n-, iso-, tert-BPBA) and Sphingomonas (n-, sec-BPBA). PMID:20962873

  16. Microbial biodegradation of aromatic alkanoic naphthenic acids is affected by the degree of alkyl side chain branching.

    PubMed

    Johnson, Richard J; Smith, Ben E; Sutton, Paul A; McGenity, Terry J; Rowland, Steven J; Whitby, Corinne

    2011-03-01

    Naphthenic acids (NAs) occur naturally in oil sands and enter the environment through natural and anthropogenic processes. NAs comprise toxic carboxylic acids that are difficult to degrade. Information on NA biodegradation mechanisms is limited, and there are no studies on alkyl branched aromatic alkanoic acid biodegradation, despite their contribution to NA toxicity and recalcitrance. Increased alkyl side chain branching has been proposed to explain NA recalcitrance. Using soil enrichments, we examined the biodegradation of four aromatic alkanoic acid isomers that differed in alkyl side chain branching: (4'-n-butylphenyl)-4-butanoic acid (n-BPBA, least branched); (4'-iso-butylphenyl)-4-butanoic acid (iso-BPBA); (4'-sec-butylphenyl)-4-butanoic acid (sec-BPBA) and (4'-tert-butylphenyl)-4-butanoic acid (tert-BPBA, most branched). n-BPBA was completely metabolized within 49 days. Mass spectral analysis confirmed that the more branched isomers iso-, sec- and tert-BPBA were transformed to their butylphenylethanoic acid (BPEA) counterparts at 14 days. The BPEA metabolites were generally less toxic than BPBAs as determined by Microtox assay. n-BPEA was further transformed to a diacid, showing that carboxylation of the alkyl side chain occurred. In each case, biodegradation of the carboxyl side chain proceeded through beta-oxidation, which depended on the degree of alkyl side chain branching, and a BPBA degradation pathway is proposed. Comparison of 16S rRNA gene sequences at days 0 and 49 showed an increase and high abundance at day 49 of Pseudomonas (sec-BPBA), Burkholderia (n-, iso-, tert-BPBA) and Sphingomonas (n-, sec-BPBA).

  17. Interaction of model aryl- and alkyl-boronic acids and 1,2-diols in aqueous solution.

    PubMed

    Marinaro, William A; Prankerd, Richard; Kinnari, Kaisa; Stella, Valentino J

    2015-04-01

    The goal of this work was to quantitate ester formation between alkyl and aryl boronic acids and vicinal-diols or 1,2-diols in aqueous solution. As used here, 1,2-diols includes polyols with one or more 1,2-diol pairs. Multiple techniques were used including apparent pKa shifts of the boronic acids using UV spectrophotometry (for aryl acids) and titration (for aryl and alkyl acids). Isothermal microcalorimetry was also used, with all reactions being enthalpically favored. For all the acids and 1,2-diols and the conditions studied, evidence only supported 1:1 ester formation. All the esters formed were found to be significantly more acidic, as Lewis acids, by 3-3.5 pKa units than the corresponding nonesterified boronic acid. The equilibrium constants for ester formation increased with increasing number of 1,2-diol pairs but stereochemistry may also play a role as sorbitol with five possible 1,2-diol pairs and five isomers (taking into account the stereochemistry of the alcohol groups) was twice as efficient at ester formation compared with mannitol, also with five possible 1,2-diol pairs but only three isomers. Alkyl boronic acids formed esters to a greater extent than aryl acids. Although some quantitative differences were seen between the various techniques used, rank ordering of the structure/reactivity was consistent. Formulation implications of ester formation between boronic acids and 1,2-diols are discussed.

  18. δ-Aminolevulinic acid dehydrase activity in the blood of men working with lead alkyls

    PubMed Central

    Millar, J. A.; Thompson, G. G.; Goldberg, A.; Barry, P. S. I.; Lowe, E. H.

    1972-01-01

    Millar, J. A., Thompson, G. G., Goldberg, A., Barry, P. S. I., and Lowe, E. H. (1972).Brit. J. industr. Med.,29, 317-320. δ-Aminolevulinic acid dehydrase activity in the blood of men working with lead alkyls. The activity of erythrocyte ALA1-dehydrase is inhibited in vivo at blood lead (Pb2+) levels within the upper range of normal (20-40 μg/100 ml) and in vitro at lead concentrations greater than 10-7 M. In view of the high sensitivity of the enzyme to Pb2+, the levels of enzyme activity in the blood of men occupationally exposed to lead alkyls, particularly tetraethyllead, were measured. It was found that the enzyme activity in an exposed group of men was significantly less (P<0·001) than in a control group, the respective mean values being 220 and 677 units of enzyme activity. Tetraethyllead is metabolized in the body via triethyllead and diethyllead ions. As the latter compound possesses properties similar to Pb2+, it was synthesized in the laboratory and its effect on ALA-dehydrase was studied. Diethyllead ion was found to inhibit ALA-dehydrase activity at concentrations greater than 5 x 10-5 M, although the degree of inhibition was less than that obtained with Pb2+. These results suggest that exposure to tetraethyllead can cause a decrease in erythrocyte ALA-dehydrase activity. PMID:5044603

  19. Uptake of perfluorinated alkyl acids by hydroponically grown lettuce (Lactuca sativa).

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; de Voogt, Pim

    2012-11-06

    An uptake study was carried out to assess the potential human exposure to perfluorinated alkyl acids (PFAAs) through the ingestion of vegetables. Lettuce (Lactuca sativa) was grown in PFAA-spiked nutrient solutions at four different concentrations, ranging from 10 ng/L to 10 μg/L. Eleven perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonic acids (PFSAs) were analyzed by HPLC-MS/MS. At the end of the experiment, the major part of the total mass of each of the PFAAs (except the short-chain, C4-C7, PFCAs) taken up by plants appeared to be retained in the nonedible part, viz. the roots. Root concentration factors (RCF), foliage/root concentration factors (FRCF), and transpiration stream concentration factors (TSCF) were calculated. For the long chained PFAAs, RCF values were highest, whereas FRCF were lowest. This indicates that uptake by roots is likely governed by sorption of PFAAs to lipid-rich root solids. Translocation from roots to shoots is restricted and highly depending on the hydrophobicity of the compounds. Although the TSCF show that longer-chain PFCAs (e.g., perfluorododecanoic acid) get better transferred from the nutrient solution to the foliage than shorter-chain PFCAs (e.g., perfluoroheptanoic acid), the major fraction of longer-chain PFCAs is found in roots due to additional adsorption from the spiked solution. Due to the strong electron-withdrawing effect of the fluorine atoms the role of the negative charge of the dissociated PFAAs is likely insignificant.

  20. Binding modes of phosphonic acid derivatives adsorbed on TiO2 surfaces: Assignments of experimental IR and NMR spectra based on DFT/PBC calculations

    NASA Astrophysics Data System (ADS)

    Geldof, D.; Tassi, M.; Carleer, R.; Adriaensens, P.; Roevens, A.; Meynen, V.; Blockhuys, F.

    2017-01-01

    A DFT study on the adsorption of a series of phosphonic acids (PAs) on the TiO2 anatase (101) and (001) surfaces was performed. The adsorption energies and geometries of the most stable binding modes were compared to literature data and the effect of the inclusion of dispersion forces in the energy calculations was gauged. As the (101) surface is the most exposed surface of TiO2 anatase, the calculated chemical shifts and vibrational frequencies of PAs adsorbed on this surface were compared to experimental 31P and 17O NMR and IR data in order to assign the two possible binding modes (mono- and bidentate) to peaks and bands in these spectra; due to the corrugated nature of anatase (101) tridentate binding is not possible on this surface. Analysis of the calculated and experimental 31P chemical shifts indicates that both monodentate and bidentate binding modes are present. For the reactive (001) surface, the results of the calculations indicate that both bi- and tridentate binding modes result in stable systems. Due to the particular sensitivity of 17O chemical shifts to hydrogen bonding and solvent effects, the model used is insufficient to assign these spectra at present. Comparison of calculated and experimental IR spectra leads to the conclusion that IR spectroscopy is not suitable for the characterization of the different binding modes of the adsorption complexes.

  1. Fatty acid alkyl esters presence in olive oil vs. organoleptic assessment.

    PubMed

    Gómez-Coca, R B; Moreda, W; Pérez-Camino, M C

    2012-12-01

    The scientific work on the authenticity and quality of olive oil is an ever-growing area. Olive oil genuineness is not only valuable for the producers, but also for the consumers who expect an actual correspondence between the products they purchase and the information on the packaging labels. Sometimes oil's rejection by consumers is just a matter of taste, sometimes is a more objective question. Low quality olive oils with weak organoleptic defects are the targets of illegal blends that can be detected by determining the content of fatty acid alkyl esters (FAAEs). In this line we have established a relationship between the FAAEs concentration of olive oils and their sensory classification. Besides, a connection between the presence of large quantities of FAAEs and fermentative organoleptic defects has been proven.

  2. [Phosphonate esterase activity in human serum (author's transl)].

    PubMed

    Labadie, M; Laplaud, P M; Lachatre, G; Breton, J C

    1980-02-01

    A simple methodology for the spectrophotometric assay of phosphonate esterase activity in human serum samples is described, featuring incubation at 30 degrees C in a medium containing p-nitrophenol and phenyl-phosphonic acid ester. Reproducibility of the method as well a mean values in normal patients vs age and sex are reported. Serum activity appears to be increased almost exclusively during pregnancy or administration of estrogenic drugs (as oral contraceptives or in prostate neoplasms).

  3. Transition metal ion-assisted photochemical generation of alkyl halides and hydrocarbons from carboxylic acids

    SciTech Connect

    Carraher, Jack; Pestovsky, Oleg; Bakac, Andreja

    2012-03-14

    Near-UV photolysis of aqueous solutions of propionic acid and aqueous Fe3+ in the absence of oxygen generates a mixture of hydrocarbons (ethane, ethylene and butane), carbon dioxide, and Fe2+. The reaction becomes mildly catalytic (about five turnovers) in the presence of oxygen which converts a portion of alkyl radicals to oxidizing intermediates that reoxidize Fe2+. The photochemistry in the presence of halide ions (X− = Cl−, Br−) generates ethyl halides via halogen atom abstraction from FeXn3−n by ethyl radicals. Near-quantitative yields of C2H5X are obtained at ≥0.05 M X−. Competition experiments with Co(NH3)5Br2+ provided kinetic data for the reaction of ethyl radicals with FeCl2+ (k = (4.0 ± 0.5) × 106 M−1 s−1) and with FeBr2+ (k = (3.0 ± 0.5) × 107 M−1 s−1). Photochemical decarboxylation of propionic acid in the presence of Cu2+ generates ethylene and Cu+. Longer-chain acids also yield alpha olefins as exclusive products. These reactions become catalytic under constant purge with oxygen which plays a dual role. It reoxidizes Cu+ to Cu2+, and removes gaseous olefins to prevent accumulation of Cu+(olefin) complexes and depletion of Cu2+. The results underscore the profound effect that the choice of metal ions, the medium, and reaction conditions exert on the photochemistry of carboxylic acids.

  4. Dietary predictors and plasma concentrations of perfluorinated alkyl acids in a Singapore population.

    PubMed

    Liu, Yu; Su, Jin; van Dam, Rob M; Prem, Kiesha; Hoong, Joey Y S; Zou, Li; Lu, Yonghai; Ong, Choon Nam

    2017-03-01

    Perfluorinated alkyl acids (PFAAs), a family of man-made organofluorinated compounds, have drawn much attention due to their ubiquitous existence in the environment and their bioaccumulation potential. Here, we examined the plasma concentrations of thirteen PFAAs in a healthy population (N = 270) in Singapore, and investigated the association between major food groups and plasma PFAA concentrations. We detected eight types of PFAAs in more than 75% of all samples (N = 270), and their median concentrations ranged from 0.05 to 8.34 ng mL(-1). Age- and gender-related differences were observed for the three dominant PFAAs, i.e., perfluorooctanesulfonic acid (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoate acid (PFOA), with concentrations being higher in men and older adults. Multiple linear regression analyses showed that fish, shellfish, red meat and poultry were associated with increased PFAAs concentrations in plasma, whereas grains and soy products showed inverse associations with PFAAs. Further, significant correlations were observed between various long-chain PFAAs and plasma concentrations of omega-3 fatty acids, suggesting seafood was a significant source of these PFAAs, within this population. Future studies on diet exposure to PFAAs are encouraged to focus more on the effects on diet pattern.

  5. Asymmetric PTC C-alkylation catalyzed by chiral derivatives of tartaric acid and aminophenols. Synthesis Of (R)- and (S)-alpha-methyl amino acids

    PubMed

    Belokon; Kochetkov; Churkina; Ikonnikov; Chesnokov; Larionov; Singh; Parmar; Vyskocil; Kagan

    2000-10-20

    A new type of efficient chiral catalyst has been elaborated for asymmetric C-alkylation of CH acids under PTC conditions. Sodium alkoxides formed from chiral derivatives of tartaric acid and aminophenols (TADDOL's 2a-e and NOBIN's 3a-h) can be used as chiral catalysts in the enantioselective alkylation, as exemplified by the reaction of Schiff's bases 1a-e derived from alanine esters and benzaldehydes with active alkyl halides. Acid-catalyzed hydrolysis of the products formed in the reaction afforded (R)-alpha-methylphenylalanine, (R)-alpha-naphthylmethylalanine, and (R)-alpha-allylalanine in 61-93% yields and with ee 69-93%. The procedure could be successfully scaled up to 6 g of substrate 1b. When (S,S)-TADDOL or (R)-NOBIN are used, the (S)-amino acids are formed. A mechanism rationalizing the observed features of the reaction has been suggested.

  6. Tuning the Band Bending and Controlling the Surface Reactivity at Polar and Nonpolar Surfaces of ZnO through Phosphonic Acid Binding.

    PubMed

    McNeill, Alexandra R; Hyndman, Adam R; Reeves, Roger J; Downard, Alison J; Allen, Martin W

    2016-11-16

    ZnO is a prime candidate for future use in transparent electronics; however, development of practical materials requires attention to factors including control of its unusual surface band bending and surface reactivity. In this work, we have modified the O-polar (0001̅), Zn-polar (0001), and m-plane (101̅0) surfaces of ZnO with phosphonic acid (PA) derivatives and measured the effect on the surface band bending and surface sensitivity to atmospheric oxygen. Core level and valence band synchrotron X-ray photoemission spectroscopy was used to measure the surface band bending introduced by PA modifiers with substituents of opposite polarity dipole moment: octadecylphosphonic acid (ODPA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctylphosphonic acid (F13OPA). Both PAs act as surface electron donors, increasing the downward band bending and the strength of the two-dimensional surface electron accumulation layer on all of the ZnO surfaces investigated. On the O-polar (0001̅) and m-plane (101̅0) surfaces, the ODPA modifier produced the largest increase in downward band bending relative to the hydroxyl-terminated unmodified surface of 0.55 and 0.35 eV, respectively. On the Zn-polar (0001) face, the F13OPA modifier gave the largest increase (by 0.50 eV) producing a total downward band bending of 1.00 eV, representing ∼30% of the ZnO band gap. Ultraviolet (UV) photoinduced surface wettability and photoconductivity measurements demonstrated that the PA modifiers are effective at decreasing the sensitivity of the surface toward atmospheric oxygen. Modification with PA derivatives produced a large increase in the persistence of UV-induced photoconductivity and a large reduction in UV-induced changes in surface wettability.

  7. CHEMISTRY OF FOG WATER IN CALIFORNIA'S CENTRAL VALLEY: 2. PHOTOCHEMICAL TRANSFORMATIONS OF AMINO ACIDS AND ALKYL AMINES. (R825433)

    EPA Science Inventory

    Although amino compounds are seemingly ubiquitous in atmospheric particles and deposition, little is known of their fate in the troposphere. We report here on the fate of 21 amino acids and alkyl amines in fog waters from Davis, California, illuminated with simulated sunlight ...

  8. Stereoselective Alkylation of the Vinylketene Silyl N,O-Acetal and Its Application to the Synthesis of Mycocerosic Acid.

    PubMed

    Nakamura, Tatsuya; Kubota, Kei; Ieki, Takanori; Hosokawa, Seijiro

    2016-01-04

    Stereoselective alkylation of the vinylketene silyl N,O-acetal possessing a chiral auxiliary has been achieved by using activated alkyl halides including allyl iodides, benzyl iodides, and propargyl iodide with Ag(I) ion in the presence of BF3·OEt2. The reaction proceeded to give reduced polyketides in high stereoselectivity. The synthesis of mycocerosic acid, a component of the cell envelope of Mycobacterium tuberculosis, has been accomplished by this methodology. During the synthetic studies, 2-methylbenzimidazole was found to be a bulky proton source which worked in the presence of liquid ammonia.

  9. Comparison of silatrane, phosphonic acid, and carboxylic acid functional groups for attachment of porphyrin sensitizers to TiO2 in photoelectrochemical cells.

    PubMed

    Brennan, Bradley J; Llansola Portolés, Manuel J; Liddell, Paul A; Moore, Thomas A; Moore, Ana L; Gust, Devens

    2013-10-21

    A tetra-arylporphyrin dye was functionalized with three different anchoring groups used to attach molecules to metal oxide surfaces. The physical, photophysical and electrochemical properties of the derivatized porphyrins were studied, and the dyes were then linked to mesoporous TiO2. The anchoring groups were β-vinyl groups bearing either a carboxylate, a phosphonate or a siloxy moiety. The siloxy linkages were made by treatment of the metal oxide with a silatrane derivative of the porphyrin. The surface binding and lability of the anchored molecules were studied, and dye performance was compared in a dye-sensitized solar cell (DSSC). Transient absorption spectroscopy was used to study charge recombination processes. At comparable surface concentration, the porphyrin showed comparable performance in the DSSC, regardless of the linker. However, the total surface coverage achievable with the carboxylate was about twice that obtainable with the other two linkers, and this led to higher current densities for the carboxylate DSSC. On the other hand, the carboxylate-linked dyes were readily leached from the metal oxide surface under alkaline conditions. The phosphonates were considerably less labile, and the siloxy-linked porphyrins were most resistant to leaching from the surface. The use of silatrane proved to be a practical and convenient way to introduce the siloxy linkages, which can confer greatly increased stability on dye-sensitized electrodes with photoelectrochemical performance comparable to that of the other linkers.

  10. DDQ-promoted dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones by a radical ion mechanism.

    PubMed

    Ding, Ye; Huang, Zhangjian; Yin, Jian; Lai, Yisheng; Zhang, Shibo; Zhang, Zhiguo; Fang, Lei; Peng, Sixun; Zhang, Yihua

    2011-09-07

    A novel and facile DDQ-mediated dehydrogenation from natural rigid polycyclic acids or flexible alkyl acids to generate lactones is described. The formation of lactones proceeds by a radical ion mechanism, which has been established by DPPH˙-mediated chemical identification, ESR spectroscopy and an enol intermediate trapping.

  11. Alkylation of nucleic acids by DNA-targeted 4-anilinoquinolinium aniline mustards: kinetic studies.

    PubMed

    O'Connor, C J; Denny, W A; Fan, J Y

    1991-01-01

    The rate of constant for hydrolysis of a series of 4-substituted aniline mustards Ar-X-pC6H4-N(CH2CH2Cl)2, where Ar is 4-anilinoquinolinium and X = O, CH2, CONH and CO, have been measured in water and 0.02 M imidazole buffer at 37 degrees C and in 50% aqueous acetone at 66 degrees C. The equilibrium binding constants of the compounds and their hydrolysis products to nucleic acids of differing base composition have been determined at varying ionic strengths, and the results are consistent with the compounds binding as expected in the DNA minor groove. The alkylating reactivity of the mustards towards these nucleic acids has been measured in water at 37 degrees C and in 0.01 M HEPES buffer over a range of temperatures from 25 degrees C to 60 degrees C. Evaluation of the thermodynamic parameters for these kinetic and equilibrium studies suggests that the interaction with nucleic acids is via an internal SN2 mechanism involving an aziridinium ion.

  12. Mn2+ complexes of 1-oxa-4,7-diazacyclononane based ligands with acetic, phosphonic and phosphinic acid pendant arms: stability and relaxation studies.

    PubMed

    Drahoš, Bohuslav; Pniok, Miroslav; Havlíčková, Jana; Kotek, Jan; Císařová, Ivana; Hermann, Petr; Lukeš, Ivan; Tóth, Eva

    2011-10-21

    A new class of macrocyclic ligands based on 1-oxa-4,7-diazacyclononane was synthesized and their Mn(2+) complexes were investigated with respect to stability and relaxation properties. Each ligand has two pendant arms involving carboxylic (H(2)L(1)--1-oxa-4,7-diazacyclononane-4,7-diacetic acid), phosphonic (H(4)L(2)--1-oxa-4,7-diazacyclononane-4,7-bis(methylenephosphonic acid)), phosphinic (H(2)L(3)--1-oxa-4,7-diazacyclononane-4,7-bis(methylenephosphinic acid)) or phenylphosphinic (H(2)L(4)--1-oxa-4,7-diazacyclononane-4,7-bis[methylene(phenyl)phosphinic acid]) acid moieties. H(2)L(3) and H(2)L(4) were synthesized for the first time. The crystal structure of the Mn(2+) complex with H(2)L(4) confirmed a coordination number of 6 for Mn(2+). The protonation constants of all ligands and the stability constants of their complexes with Mn(2+) and some biologically or biomedically relevant metal ions were determined by potentiometry. The protonation sequence of H(2)L(3) was followed by (1)H and (31)P NMR titration and the second protonation step was attributed to the second macrocyclic nitrogen atom. The potentiometric data revealed a relatively low thermodynamic stability of the Mn(2+) complexes with all ligands investigated. For H(2)L(3) and H(2)L(4), full Mn(2+) complexation cannot be achieved even with 100% ligand excess. The transmetallation of MnL(1) and MnL(2) with Zn(2+) was too fast to be followed at pH 6. Variable temperature (1)H NMRD and (17)O NMR measurements have been performed on MnL(1) and MnL(2) to provide information on water exchange and rotational dynamics. The (17)O chemical shifts indicate hydration equilibrium between mono- and bishydrated species for MnL(1), while MnL(2) is monohydrated. The water exchange is considerably faster on MnL(1) (k(ex)(298) = 1.2 × 10(9) s(-1)) than on MnL(2) (k(ex)(298) = 1.2 × 10(7) s(-1)). Small endogenous anions (phosphate, carbonate, citrate) do not replace the coordinated water in either of the complexes, but they

  13. Antioxidant activity of ferulic acid alkyl esters in a heterophasic system: a mechanistic insight.

    PubMed

    Anselmi, Cecilia; Centini, Marisanna; Granata, Paola; Sega, Alessandro; Buonocore, Anna; Bernini, Andrea; Facino, Roberto Maffei

    2004-10-20

    The antioxidant activity of some esters of ferulic acid with the linear fatty alcohols C7, C8 (branched and linear), C9, C11, C12, C13, C15, C16, and C18 has been studied in homogeneous and heterogeneous phases. Whereas in homogeneous phase all of the alkyl ferulates possessed similar radical-scavenging abilities, in rat liver microsomes they showed striking differences, the more effective being C12 (7) (IC50 = 11.03 M), linear C8 (3) (IC50 = 12.40 microM), C13 (8) (IC50 = 18.60 microM), and C9 (5) (IC50 = 19.74 microM), followed by C7 (2), C15 (9), C11 (6), branched C8 (4), C16 (10), and C18 (11) (ferulic acid was the less active, IC50 = 243.84 microM). All of the molecules showed similar partition coefficients in an octanol-buffer system. Three-dimensional studies (NMR in solution, modeling in vacuo) indicate that this behavior might be due to a different anchorage of the molecules with the ester side chain to the microsomal phospholipid bilayer and to a consequent different orientation/positioning of the scavenging phenoxy group outside the membrane surface against the flux of oxy radicals.

  14. 40 CFR 721.10442 - 1,2-Benzenedicarboxylic acid, di-C6-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-branched and linear alkyl esters. 721.10442 Section 721.10442 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C6-14-branched and linear...

  15. 40 CFR 721.10442 - 1,2-Benzenedicarboxylic acid, di-C6-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters. 721.10442 Section 721.10442 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C6-14-branched and linear...

  16. 40 CFR 721.10441 - 1,2-Benzenedicarboxylic acid, di-C7-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-branched and linear alkyl esters. 721.10441 Section 721.10441 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C7-14-branched and linear...

  17. 40 CFR 721.10441 - 1,2-Benzenedicarboxylic acid, di-C7-14-branched and linear alkyl esters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-branched and linear alkyl esters. 721.10441 Section 721.10441 Protection of Environment ENVIRONMENTAL...-branched and linear alkyl esters. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1,2-benzenedicarboxylic acid, di-C7-14-branched and linear...

  18. SOLVENT EXTRACTION PROCESS FOR THE RECOVERY OF METALS FROM PHOSPHORIC ACID

    DOEpatents

    Bailes, R.H.; Long, R.S.

    1958-11-01

    > A solvent extraction process is presented for recovering metal values including uranium, thorium, and other lanthanide and actinide elements from crude industrial phosphoric acid solutions. The process conslsts of contacting said solution with an immisclble organic solvent extractant containing a diluent and a material selected from the group consisting of mono and di alkyl phosphates, alkyl phosphonates and alkyl phosphites. The uranlum enters the extractant phase and is subsequently recovered by any of the methods known to the art. Recovery is improved if the phosphate solution is treated with a reducing agent such as iron or aluminum powder prior to the extraction step.

  19. Surface active molecules: preparation and properties of long chain n-acyl-l-alpha-amino-omega-guanidine alkyl acid derivatives.

    PubMed

    Infante, R; Dominguez, J G; Erra, P; Julia, R; Prats, M

    1984-12-01

    Synopsis A new route for the synthesis of long chain N(alpha)-acyl-l-alpha-amino-omega-guamdine alkyl acid derivatives, with cationic or amphoteric character has been established. The general formula of these compounds is shown below. A physico-chemical and antimicrobial study of these products as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue (x) and the number of carbons between the omega-guanidine and omega-carboxyl group (n) has been investigated. The water solubility, surface tension, critical micelle concentration (c.m.c.) and minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria (including Pseudomonas) has been determined. Dicyclohexylcarbodiimide has been used to condense fatty acids and alpha-amino-omega-guanidine alkyl acids. In these conditions protection of the omega-guanidine group is not necessary. The main characteristic of this synthetic procedure is the use of very mild experimental conditions (temperature, pH) to form the amide linkage which leads to pure optical compounds in high yield in the absence of electrolytes. The results show that some structural modifications, particularly the protection of the carboxyl group, promote variations of the surfactant and antimicrobial properties. Only those molecules with the blocked carboxyl group (cationic molecules, where R = Me, Et or Pr) showed a good surfactant and antimicrobial activity. When the carboxyl group was unprotected (amphoteric molecules, where R = Na(+)) the resulting compounds were inactive.

  20. Perfluorinated alkylated acids in groundwater and drinking water: identification, origin and mobility.

    PubMed

    Eschauzier, Christian; Raat, Klaasjan J; Stuyfzand, Pieter J; De Voogt, Pim

    2013-08-01

    Human exposure to perfluorinated alkylated acids (PFAA) occurs primarily via the dietary intake and drinking water can contribute significantly to the overall PFAA intake. Drinking water is produced from surface water and groundwater. Waste water treatment plants have been identified as the main source for PFAA in surface waters and corresponding drinking water. However, even though groundwater is an important source for drinking water production, PFAA sources remain largely uncertain. In this paper, we identified different direct and indirect sources of PFAA to groundwater within the catchment area of a public supply well field (PSWF) in The Netherlands. Direct sources were landfill leachate and water draining from a nearby military base/urban area. Indirect sources were infiltrated rainwater. Maximum concentrations encountered in groundwater within the landfill leachate plume were 1.8 μg/L of non branched perfluorooctanoic acid (L-PFOA) and 1.2 μg/L of perfluorobutanoic acid (PFBA). Sum concentrations amounted to 4.4 μg/L total PFAA. The maximum concentration of ΣPFAA in the groundwater originating from the military camp was around 17 ng/L. Maximum concentrations measured in the groundwater halfway the landfill and the PWSF (15 years travel distance) were 29 and 160 ng/L for L-PFOA and PFBA, respectively. Concentrations in the groundwater pumping wells (travel distance >25 years) were much lower: 0.96 and 3.5 ng/L for L-PFOA and PFBA, respectively. The chemical signature of these pumping wells corresponded to the signature encountered in other wells sampled which were fed by water that had not been in contact with potential contaminant sources, suggesting a widespread diffuse contamination from atmospheric deposition.

  1. Concentration effects in the nucleophilic reactions of tertiary amines in aqueous solutions: Alkylation of amines with chloroacetic acid

    NASA Astrophysics Data System (ADS)

    Kazantsev, O. A.; Baruta, D. S.; Shirshin, K. V.; Sivokhin, A. P.; Kamorin, D. M.

    2011-03-01

    In alkylations of tertiary amines with chloroacetic acid in aqueous solutions, an increase in the initial concentrations of reagents to a certain level led to an abrupt increase in the initial rates and conversions attained during the control time. Viscosimetric and refractometric data showed that association with reagents occurred in these systems. The structures of associates that determine the character of the concentration effects of the Menschutkin reaction in water were suggested.

  2. Sulfotanone, a new alkyl sulfonic acid derivative from Streptomyces sp. IFM 11694 with TRAIL resistance-overcoming activity.

    PubMed

    Abdelfattah, Mohamed S; Ishikawa, Naoki; Karmakar, Utpal K; Ishibashi, Masami

    2016-04-01

    One new alkyl sulfonic acid derivative, sulfotanone (1), and the known panosialin wA (2) were isolated from the methanolic extract of mycelium of Streptomyces sp. 11694. The structure of the new compound (1) was established by a combination of spectroscopic techniques, including HRESIMS, IR, 1D and 2D NMR measurements. Compound 1 (40 µM) in combination with TRAIL showed synergistic activity in sensitizing TRAIL-resistance in human gastric adenocarcinoma cell lines.

  3. A New Epoxy Bis-Phosphonate Crosslinker for Durable Fire Retardancy on Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new epoxy bis-phosphonate crosslinker for cotton [2-(dimethoxy-phosphorylmethyl)-oxiranylmethyl]-phosphonic acid dimethyl ester was prepared in two steps from 3-chloro-2-chloromethylpropene in 55% yield. The new monomer was characterized by proton and carbon NMR and GC-mass spectrometry. This cro...

  4. Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus).

    PubMed

    Christie, Ian; Reiner, Jessica L; Bowden, John A; Botha, Hannes; Cantu, Theresa M; Govender, Danny; Guillette, Matthew P; Lowers, Russell H; Luus-Powell, Wilmien J; Pienaar, Danie; Smit, Willem J; Guillette, Louis J

    2016-07-01

    Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area.

  5. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  6. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  7. Syn-Selective Synthesis of β-Branched α-Amino Acids by Alkylation of Glycine-Derived Imines with Secondary Sulfonates.

    PubMed

    Lou, Sha; McKenna, Grace M; Tymonko, Steven A; Ramirez, Antonio; Benkovics, Tamas; Conlon, David A; González-Bobes, Francisco

    2015-10-16

    A syn-selective synthesis of β-branched α-amino acids has been developed based on the alkylation of glycine imine esters with secondary sulfonates. The potassium counterion for the enolate, the solvent, and the leaving group on the electrophile were key levers to maximize the diasteroselectivity of the alkylation. The optimized conditions enabled a straightforward preparation of a number of β-branched α-amino acids that can be challenging to obtain.

  8. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  9. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  10. 40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-boxy-lic acid, ethyl es-ter, bis- amino]-alkyl-phenyl]-az-o] (ge-ner-ic name). (a) Chemical substance...-lic acid, ethyl ester, bis- -amino]-alkyl-phenyl]-azo] (PMN P-87-304) is subject to reporting under... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ni-tro-thio-phene-car-boxy-lic...

  11. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  12. Novel self-assembled phosphonic acids monolayers applied in N-channel perylene diimide (PDI) organic field effect transistors

    NASA Astrophysics Data System (ADS)

    Cheng, Heng; Huai, Jinyue; Cao, Li; Li, Zhefeng

    2016-08-01

    Phosphoric acid (PA) self-assembled monolayers (SAMs) have been developed for applications in organic field-effect transistors (OFETs). This efficient interface modification is helpful for semiconductor layer to form crystal thin film during vapor deposition. Results show that the PDI-i8C based OFETs with PA SAMs exhibit field-effect mobilities up to 0.014 cm2 V-1 s-1 (with ODPA as SAMs), which is over 500 times higher than the device without SAMs. Also, transistors with Naph6PA as SAMs show up to 1.5 × 10-3 cm2 V-1 s-1. By studying the morphology of semiconductor layer and SAMs surface, it is found that ODPA bilayer structure plays a key role in inducing PDI-i8C to form orderly crystal thin film.

  13. Studies on the Labeling of Ethylenediaminetetramethylene Phosphonic Acid, Methylene Diphosphonate, Sodium Pyrophosphate and Hydroxyapatite with Lutetium-177 for use in Nuclear Medicine

    PubMed Central

    Abbasi, Imtiaz Ahmed

    2015-01-01

    For the treatment of skeletal metastasis, a therapeutic radionuclide tagged with a bone seeking ligand is required, while for radiation synovectomy (RS), a therapeutic radionuclide irreversibly attached to pre-formed particles of appropriate size is required. Radio lanthanides are mostly therapeutic, and ligands containing phosphate groups are predominantly bone seekers. Exploiting these facts, number of new therapeutic radiopharmaceuticals could be developed. Labeling of four phosphate containing materials was pursued in the present study. It was hypothesized that various 177Lu-labeled bone-seeking complexes such as 177Lu-ethylenediaminetetramethylene phosphonic acid (EDTMP), 177Lu-methylene diphosphonate (MDP) and 177Lu-pyrophosphate (PYP) could be developed as agents for palliative radiotherapy of bone pain due to skeletal metastases, and 177Lu-Hydroxyapatite (HA) could be developed as an agent for radiosynovectomy of small joints. Lyophilized kit vials of EDTMP, MDP and sodium pyrophosphate (Na-PYP) were formulated. HA particles were synthesized locally and purity was checked by high-performance liquid chromatography (HPLC). 177Lu was labeled with EDTMP, MDP, PYP, and HA and the behavior of all was studied by radio-thin layer chromatography (TLC) radio-HPLC and radio-electrophoresis. Radio-TLC confirmed the labeling. HPLC analysis too verified the labeling. Radio-electrophoresis results depicted peaks for 177Lu-MDP, 177Lu-EDTMP and 177Lu-PYP at 3.37 ± 0.06 cm, 5.53 ± 0.15 cm and 7.03 ± 0.06 cm respectively confirming negative charge on each specie as all migrated toward positive anode. All 3 methods verified the labeling. The study demonstrated that EDTMP, MDP and PYP form stable complexes with 177Lu in injectable solution form. HA particulates could too be labeled with 177Lu with high radiochemical yields (>98%) in suspension form. Former three could be utilized as bone-pain palliation agents for the treatment of bone metastases, and the later could be

  14. Studies on the Labeling of Ethylenediaminetetramethylene Phosphonic Acid, Methylene Diphosphonate, Sodium Pyrophosphate and Hydroxyapatite with Lutetium-177 for use in Nuclear Medicine.

    PubMed

    Abbasi, Imtiaz Ahmed

    2015-01-01

    For the treatment of skeletal metastasis, a therapeutic radionuclide tagged with a bone seeking ligand is required, while for radiation synovectomy (RS), a therapeutic radionuclide irreversibly attached to pre-formed particles of appropriate size is required. Radio lanthanides are mostly therapeutic, and ligands containing phosphate groups are predominantly bone seekers. Exploiting these facts, number of new therapeutic radiopharmaceuticals could be developed. Labeling of four phosphate containing materials was pursued in the present study. It was hypothesized that various (177)Lu-labeled bone-seeking complexes such as (177)Lu-ethylenediaminetetramethylene phosphonic acid (EDTMP), (177)Lu-methylene diphosphonate (MDP) and (177)Lu-pyrophosphate (PYP) could be developed as agents for palliative radiotherapy of bone pain due to skeletal metastases, and (177)Lu-Hydroxyapatite (HA) could be developed as an agent for radiosynovectomy of small joints. Lyophilized kit vials of EDTMP, MDP and sodium pyrophosphate (Na-PYP) were formulated. HA particles were synthesized locally and purity was checked by high-performance liquid chromatography (HPLC). (177)Lu was labeled with EDTMP, MDP, PYP, and HA and the behavior of all was studied by radio-thin layer chromatography (TLC) radio-HPLC and radio-electrophoresis. Radio-TLC confirmed the labeling. HPLC analysis too verified the labeling. Radio-electrophoresis results depicted peaks for (177)Lu-MDP, (177)Lu-EDTMP and (177)Lu-PYP at 3.37 ± 0.06 cm, 5.53 ± 0.15 cm and 7.03 ± 0.06 cm respectively confirming negative charge on each specie as all migrated toward positive anode. All 3 methods verified the labeling. The study demonstrated that EDTMP, MDP and PYP form stable complexes with (177)Lu in injectable solution form. HA particulates could too be labeled with (177)Lu with high radiochemical yields (>98%) in suspension form. Former three could be utilized as bone-pain palliation agents for the treatment of bone metastases, and

  15. Design of a metal primer containing a dithiooctanoate monomer and a phosphonic acid monomer for bonding of prosthetic light-curing resin composite to gold, dental precious and non-precious metal alloys.

    PubMed

    Ikemura, Kunio; Fujii, Toshihide; Negoro, Noriyuki; Endo, Takeshi; Kadoma, Yoshinori

    2011-01-01

    The effect of metal primers on adhesion of a resin composite to dental metal alloys was investigated. Experimental primers containing a dithiooctanoate monomer [10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT) or 6-methacryloyloxyhexyl 6,8-dithiooctanoate (6-MHDT)] and a phosphonic acid monomer [6-methacryloyloxyhexyl phosphonoacetate (6-MHPA) or 6-methacryloyloxyhexyl 3-phosphonopropionate (6-MHPP)] were prepared. After treating Au, Au alloy, Ag alloy, Au-Ag-Pd alloy, and Ni-Cr alloy with the experimental primers, their shear bond strengths (SBSs) with a prosthetic light-curing resin composite (Solidex, Shofu Inc., Japan) were measured after 1-day storage followed by 5,000 thermal cycles. The SBSs between Solidex and the primer-treated metals which were incubated in air at 50°C for 2 months were further measured. Results showed that the SBSs [mean (SD)] of all metal adherends treated with primer DT-PA-1 (5.0 wt% 10-MDDT, 1.0 wt% 6-MHPA) ranged between 31.2 (5.2) and 34.5 (5.8) MPa. The SBSs of the primer-treated metals did not degrade after 2-month incubation at 50°C. Therefore, a combined primer application consisting of a dithiooctanoate monomer and a phosphonic acid monomer provided efficacious bonding to Au as well as precious and non-precious metal alloys.

  16. Quinolone antimicrobial agents. 1. Versatile new synthesis of 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids.

    PubMed

    Mitscher, L A; Gracey, H E; Clark, G W; Suzuki, T

    1978-05-01

    A flexible reaction sequence has been developed which starts with readily available anthranilic acids or isatoic anhydrides and leads regiospecifically to 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids after reaction with 1,3-dicarbonyl compounds. The sequence is superior to earlier published methods by allowing electron-releasing and -withdrawing groups in any position on the aro;atic ring, by allowing convenient substitution at C2, and better overall yield. A number of new and known antimicrobial agents were prepared and tested in vitro, demonstrating, inter alia, that substitution of the H at C2 abolished antibacterial activity.

  17. Metabolic properties of phosphonate esters.

    PubMed

    Somogyi, G; Buchwald, P; Bodor, N

    2004-05-01

    The object of the present work was to investigate the difference in the metabolism of the phosphonate derivatives of primary or secondary hydroxyl groups. To study the phosphorolytic cleavage of such P-O bonds, zidovudine (AZT) hexanoyloxymethyl-methylphosphonate (HOM-AZT-P), an ester of a primary OH functionality, and methyl-pivaloyloxymethyl-testosterylphosphonate (POM-T-P), an ester of a secondary OH functionality, were prepared. The actions of pure enzymes such as alkaline phosphatase and phosphodiesterase on the corresponding phosphonate compounds (AZT-P and T-P) were investigated at various pH values. The phosphonate derivative of the secondary hydroxyl group of testosterone proved completely resistant to such phosphorolytic attacks, and release of free testosterone could not be detected. The phosphonate derivative of the primary hydroxyl group of zidovudine proved resistant to phosphodiesterase, but not to alkaline phosphatase, and in this second case, release of free zidovudine could be detected.

  18. The role of alkyl chain length of monothiol-terminated alkyl carboxylic acid in the synthesis, characterization, and application of gelatin-g-poly(N-isopropylacrylamide) carriers for antiglaucoma drug delivery.

    PubMed

    Luo, Li-Jyuan; Lai, Jui-Yang

    2017-02-01

    To improve ocular bioavailability and extend pharmacological response, this study aims to investigate the role of alkyl chain length of monothiol-terminated alkyl carboxylic acids in the synthesis, characterization, and application of gelatin-g-poly(N-isopropylacrylamide) (GN) biodegradable in situ gelling carriers for antiglaucoma drug delivery. In the presence of mercaptoacetic acid (MAA), mercaptopropionic acid (MPA), mercaptobutyric acid (MBA), or mercaptohexanoic acid (MHA) as a chain transfer agent, the carboxylic end-capped poly(N-isopropylacrylamide) samples were prepared by free radical polymerization technique. Our results showed that with increasing alkyl chain length, the hydrophobicity of thermo-responsive polymer segments significantly increased, mainly due to an increase in CH stretching frequencies. In addition, the greater hydrophobic association favored the decrease in both phase transition temperature and weight loss of GN copolymers, thereby accelerating their temperature-triggered gelation process and retarding the degradation progress under physiological conditions. The benefits from these features allowed the pilocarpine carriers to increase drug payload and extend drug release. Irrespective of carbon number of monothiol-terminated alkyl carboxylic acid, the synthesized GN materials exhibited high tolerance to corneal endothelial cells without any evidence of inhibited proliferation, viability loss, inflammatory stimulation, and functional abnormality, indicating good biocompatibility. Results of clinical observations and histological examinations demonstrated that the therapeutic efficacies in treating glaucomatous damage are in response to in vivo drug release profiles from various intracamerally injected GN carriers. The research findings suggest the influence of alkyl chain length of chain transfer agent-mediated polymer hydrophobicity and degradability on pharmacological bioavailability and action of pilocarpine in a glaucomatous rabbit

  19. Selective Alkylation of C-Rich Bulge Motifs in Nucleic Acids by Quinone Methide Derivatives.

    PubMed

    Lönnberg, Tuomas; Hutchinson, Mark; Rokita, Steven

    2015-09-07

    A quinone methide precursor featuring a bis-cyclen anchoring moiety has been synthesized and its capacity to alkylate oligonucleotide targets quantified in the presence and absence of divalent metal ions (Zn(2+) , Ni(2+) and Cd(2+) ). The oligonucleotides were designed for testing the sequence and secondary structure specificity of the reaction. Gel electrophoretic analysis revealed predominant alkylation of C-rich bulges, regardless of the presence of divalent metal ions or even the bis-cyclen anchor. This C-selectivity appears to be an intrinsic property of the quinone methide electrophile as reflected by its reaction with an equimolar mixture of the 2'-deoxynucleosides. Only dA-N1 and dC-N3 alkylation products were detected initially and only the dC adduct persisted for detection under conditions of the gel electrophoretic analysis.

  20. New structural forms in molecular metal phosphonates: novel tri- and hexanuclear zinc(II) cages containing phosphonate and pyrazole ligands.

    PubMed

    Chandrasekhar, Vadapalli; Kingsley, Savariraj; Rhatigan, Brian; Lam, Matthew K; Rheingold, Arnold L

    2002-03-11

    The reaction of ZnCl(2) with tert-butylphosphonic acid and 3,5-dimethylpyrazole in the presence of triethylamine as a hydrogen chloride scavenger affords a trinuclear molecular zinc phosphonate [Zn(3)Cl(2)(3,5-Me(2)Pz)(4)(t-BuPO(3))(2)]. The structure of this compound contains a planar trizinc assembly containing two bicapping mu(3) [t-BuPO(3)](2-) ligands and terminal pyrazole and chloride ligands. In contrast an analogous reaction of ZnCl(2) with phenylphosphonic acid and 3,5-dimethylpyrazole affords a hexanuclear zinc phosphonate [Zn(6)Cl(4)(3,5-Me(2)PzH)(8)(PhPO(3))(4)]. The six zinc centers are arranged in a chairlike conformation. The four phosphonates in this complex also act as bridging tripodal mu(3) [RPO(3)](2-) ligands.

  1. Enantioselective Alkylation of Amino Acid Derivatives Promoted by Cyclic Peptoids under Phase-Transfer Conditions.

    PubMed

    Schettini, Rosaria; De Riccardis, Francesco; Della Sala, Giorgio; Izzo, Irene

    2016-03-18

    The effects of substituents and cavity size on catalytic efficiency of proline-rich cyclopeptoids under phase-transfer conditions were studied. High affinity constants (Ka) for the sodium and potassium cations, comparable to those reported for crown ethers, were observed for an alternated N-benzylglycine/L-proline hexameric cyclopeptoid. This compound was found to catalyze the alkylation of N-(diphenylmethylene)glycine cumyl ester in values of enantioselectivities comparable with those reported for the Cinchona alkaloid ammonium salts derivatives (83-96% ee), and with lower catalyst loading (1-2.5% mol), in the presence of a broad range of benzyl, allyl and alkyl halides.

  2. Targeted synthesis of silicomolybdic acid (Keggin acid) inside mesoporous silica hollow spheres for Friedel-Crafts alkylation.

    PubMed

    Dou, Jian; Zeng, Hua Chun

    2012-10-03

    Herein we report an inside-out preinstallation-infusion-hydration method for targeted synthesis of Keggin heteropoly acids (silicomolybdic acid, H(4)SiMo(12)O(40)) within mesoporous silica (SiO(2)) hollow spheres. In this process, discrete molybdenum dioxide (MoO(2)) nanoparticles with diameter size ranging from 25 to 60 nm were first prepared by a one-pot hydrothermal route in water/ethanol mixed solvents at 180 °C, which were then used as cores to grow the shell of supramolecular templated silica with tetraethyl orthosilicate (TEOS) and hexadecyltrimethyl- ammonium chloride (CTACl) in alkaline solution. By thermal treatment of as-synthesized MoO(2)@SiO(2) core-shell spheres, the organic template was burned off and mesoporous shell was formed (BET specific surface area was as high as 872 m(2)/g). Meanwhile, the encapsulated MoO(2) was oxidized to Mo(6+) and infused to the mesoporous silica shells, forming heptamolybdate species (Mo(7)O(24)(6-)) uniformly dispersed on the mesopore surfaces of silica, while generating void space at the center of spheres. After hydration with water, H(4)SiMo(12)O(40) was formed by reaction between the surface Mo(7)O(24)(6-) and silica species in the presence of water. The prepared H(4)SiMo(12)O(40) @mSiO(2) hollow spheres were tested for Friedel-Crafts alkylation of toluene by benzyl alcohol. The H(4)SiMo(12)O(40)@mSiO(2) catalysts fabricated via this novel route exhibited excellent catalytic activity toward benzylation of toluene, which was approximately 2.6 times as high as that of commercial Amberlyst-15 catalyst. In addition, the H(4)SiMo(12)O(40)@mSiO(2) catalyst was very robust and could be reused after regeneration.

  3. A surprising substituent effect provides a superior boronic acid catalyst for mild and metal-free direct Friedel-Crafts alkylations and prenylations of neutral arenes.

    PubMed

    Ricardo, Carolynne L; Mo, Xiaobin; McCubbin, J Adam; Hall, Dennis G

    2015-03-09

    The development of more general and efficient catalytic processes for Friedel-Crafts alkylations is an important objective of interest toward the production of pharmaceuticals and commodity chemicals. Herein, 2,3,4,5-tetrafluorophenylboronic acid was identified as a potent air- and moisture-tolerant metal-free catalyst that significantly improves the scope of direct Friedel-Crafts alkylations of a variety of slightly activated and neutral arenes, including polyarenes, with allylic and benzylic alcohols. This method also provides a simple alternative for the direct installation of prenyl units commonly found in naturally occurring arenes. Alkylations with benzylic alcohols occur under exceptionally mild conditions.

  4. Heterogeneous catalysis by solid superacids--14. Perfluorinated resinsulfonic acid (nafion-h) catalyzed Friedel-crafts alkylation of toluene and phenol with alkyl chloroformates and oxalates

    SciTech Connect

    Olah, G.A.; Meidar, D.; Malhotra, R.; Olah, J.A.; Narang, S.C.

    1980-01-01

    Product distributions obtained in the alkylation of toluene with methyl, ethyl, and isopropyl chloroformate and dimethyl oxalate and of phenol with methyl and ethyl chloroformate and dimethyl- and diethyloxalate.

  5. 3D-QSAR studies and molecular docking on [5-(4-amino-1 H-benzoimidazol-2-yl)-furan-2-yl]-phosphonic acid derivatives as fructose-1,6-biphophatase inhibitors

    NASA Astrophysics Data System (ADS)

    Lan, Ping; Xie, Mei-Qi; Yao, Yue-Mei; Chen, Wan-Na; Chen, Wei-Min

    2010-12-01

    Fructose-1,6-biphophatase has been regarded as a novel therapeutic target for the treatment of type 2 diabetes mellitus (T2DM). 3D-QSAR and docking studies were performed on a series of [5-(4-amino-1 H-benzoimidazol-2-yl)-furan-2-yl]-phosphonic acid derivatives as fructose-1,6-biphophatase inhibitors. The CoMFA and CoMSIA models using thirty-seven molecules in the training set gave r cv 2 values of 0.614 and 0.598, r 2 values of 0.950 and 0.928, respectively. The external validation indicated that our CoMFA and CoMSIA models possessed high predictive powers with r 0 2 values of 0.994 and 0.994, r m 2 values of 0.751 and 0.690, respectively. Molecular docking studies revealed that a phosphonic group was essential for binding to the receptor, and some key features were also identified. A set of forty new analogues were designed by utilizing the results revealed in the present study, and were predicted with significantly improved potencies in the developed models. The findings can be quite useful to aid the designing of new fructose-1,6-biphophatase inhibitors with improved biological response.

  6. Intra- and intermolecular alkylation of N,O-acetals and π-activated alcohols catalyzed by in situ generated acid.

    PubMed

    Hamon, Mélanie; Dickinson, Niall; Devineau, Alice; Bolien, David; Tranchant, Marie-José; Taillier, Catherine; Jabin, Ivan; Harrowven, David C; Whitby, Richard J; Ganesan, A; Dalla, Vincent

    2014-03-07

    Intramolecular and intermolecular alkylations of carbocation precursors of limited ionization ability, principally N,O-acetals, without the use of an exogenous reagent have been developed. The reactions are carried out in 1,1,2,2-tetrachloroethane (TCE) and take advantage of the ability of this solvent to continuously release small amounts of HCl by thermolytic elimination. A study of the reaction led to several improved protocols such as (1) preheated TCE, (2) microwave-assisted reactions, and (3) flow or sealed-tube conditions, which allow significant reaction rate enhancements and made possible some challenging reactions such as the α-amidoalkylation of ketones. Studies using flow chemistry confirmed not only that very low concentrations of HCl generated from the solvent were responsible for the reactivity but also that TCE had additional beneficial properties in comparison to other chlorinated solvents such as dichloroethane. The method can easily be extended to the alkylation using proelectrophiles such as π-activated alcohols, which are normally unreactive toward HCl catalysis. This work represents the first successful use of HCl, the simplest strong Brønsted acid, as an efficient alkylation catalyst.

  7. Enantioselective sp(3) C-H alkylation of γ-butyrolactam by a chiral Ir(I) catalyst for the synthesis of 4-substituted γ-amino acids.

    PubMed

    Tahara, Yu-ki; Michino, Masamichi; Ito, Mamoru; Kanyiva, Kyalo Stephen; Shibata, Takanori

    2015-12-04

    Ir-catalyzed sp(3) C-H alkylation of γ-butyrolactam with alkenes was used for the highly enantioselective synthesis of 5-substituted γ-lactams, which were readily converted into chiral 4-substituted γ-amino acids. A broad scope of alkenes was amenable as coupling partners, and the alkylated product using acrylate could be transformed into the key intermediate of pyrrolam A synthesis.

  8. Interaction of potassium phosphonate fungicide in laterite soil.

    PubMed

    Kumar, R Anil; Velayudhan, K T; Vasu, K; Ramachandran, V; Bhai, R Susheela; Unnikrishnan, G

    2005-10-01

    Potassium phosphonate is a fungicide widely used to control Phytophthora fungi species in many crops all over the world. In this paper, an attempt has been made to study the interaction of potassium phosphonate with soil under varying pH and calcium level. Several reports available in literature indicate that the phosphonate in organic form adsorb strongly on almost all mineral surfaces and natural materials like soil and sediments. The present study conducted on laterite soil of Kerala using 2 mm sieved sample indicated that phosphonate obeys Freundlich adsorption isotherm. Though at lower concentrations, Langmuir model equally fits well, deviation was observed at higher concentrations. pH and calcium content of the soil had striking influence on the interaction of the chemical with the soil. The calcium source also appeared to influence the adsorption phenomenon. Since potassium phosphonate is extensively used to control Phytophthora fungi species in black pepper (Piper nigrum) plantations in India and liming is a standard practice followed as soil amendment in acid soils to increase the soil pH, this study may help to maintain good soil quality.

  9. Synthesis of biologically active phosphonates from Lesquerella oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bisphosphonates and vinyl phosphonates are two classes of compounds that have much potential, namely as pharmaceutical agents and synthetic building blocks. Previous studies have shown success in synthesizing these compounds from hydroxy fatty acids (HFAs) found in Ricinus communis, commonly known a...

  10. N-Chlorosuccinimide-mediated oxidative chlorination of thiols to Nα-protected amino alkyl sulfonyl azides and their utility in the synthesis of sulfonyl triazole acids.

    PubMed

    Sharnabai, K M; Krishnamurthy, M; Sagar, N R; Santhosh, L; Vommina, Sureshbabu V

    2016-11-30

    An efficient oxidative chlorination of thiols to Nα-protected amino alkyl sulfonyl azides is delineated. The reaction involves in situ generation of sulfonyl chloride employing N-chlorosuccinimide and tetrabutylammonium chloride-water in acetonitrile, followed by the reaction with sodium azide. The protocol is simple, straight forward, mild and high yielding. Amino acids with simple as well as bifunctional side chains were used to obtain Nα-protected amino alkyl sulfonyl azides. Further, sulfonyl azides were utilized to synthesize unnatural amino acids via Cu(OAc)2.H2O/2-amino phenol catalyzed Click reaction with propiolic acid.

  11. A COMPARISON OF THE SPECIFICITY OF INHIBITION BY PHOSPHONATE ESTERS OF THE FIRST COMPONENT OF COMPLEMENT AND THE ANTIGEN-INDUCED RELEASE OF HISTAMINE FROM GUINEA PIG LUNG

    PubMed Central

    Becker, Elmer L.; Austen, K. Frank

    1964-01-01

    The ability of a number p-nitrophenylethyl alkyl, phenyl alkyl, chloroalkyl, and aminoalkyl phosphonates to inhibit the activated first component (C'1a) of guinea pig complement, and the antigen-induced release of histamine from sliced, perfused guinea pig lung has been compared. C'1a in its reactivity with these phosphonates is distinctly more similar to trypsin than to any of the other enzymes studied previously. It is suggested that both trypsin and C'1a possess an anionic group in the active center of the respective enzyme, but the distance between the anionic and esteratic site in C'1a might be less than in trypsin. The pattern of inhibition of histamine relase by the alkyl, phenyl alkyl, and chloroalkyl phosphonates is similar to the inhibition of C'1a by these compounds, although distinct differences are apparent. The aminoalkyl phosphonates are distinctly less active inhibitors of histamine release than the corresponding alkyl phosphonates, whereas the reverse is true of the inhibition of C'1a. On the basis of these differences, it is tentatively concluded that the organophosphorus-inhibitable enzymes in the guinea pig systems studied here are similar but not identical. PMID:14212115

  12. Lewis Acid Catalyzed Friedel-Crafts Alkylation of Alkenes with Trifluoropyruvates.

    PubMed

    Xiang, Bin; Xu, Teng-Fei; Wu, Liang; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-05-06

    A Friedel-Crafts alkylation reaction of styrenes with trifluoropyruvates has been developed, which delivered allylic alcohols in excellent yields (up to 98%) using the Ni(ClO4)2·6H2O/bipyridine complex as a catalyst. The asymmetric reaction was catalyzed by the chiral Cu(OTf)2/bisoxazoline complex to afford the corresponding chiral allylic alcohols bearing trifluoromethylated quaternary stereogenic centers in moderate enantioselectivities (up to 75% ee).

  13. Survey of organic acid eluents for anion chromatography

    SciTech Connect

    Book, D.E.

    1981-10-01

    Of all the potential eluents surveyed (including aromatic, sulfonic, phosphonic, among other acids), only the carboxylic acids and the nitrophenols are recommended as eluents for anion chromatography. The concentration of the eluent should be in the range 5 x 10/sup -5/ to 1 x 10/sup -3/ M. The eluent should have the same charge as inorganic anions, a higher charge than organic acid samples. Choice of eluents for separation of halides, chloride and sulfate, multivalent inorganic anions, small alkyl acids, and aromatic acids is discussed. (DLC)

  14. Water-mediated recognition of simple alkyl chains by heart-type fatty-acid-binding protein.

    PubMed

    Matsuoka, Shigeru; Sugiyama, Shigeru; Matsuoka, Daisuke; Hirose, Mika; Lethu, Sébastien; Ano, Hikaru; Hara, Toshiaki; Ichihara, Osamu; Kimura, S Roy; Murakami, Satoshi; Ishida, Hanako; Mizohata, Eiichi; Inoue, Tsuyoshi; Murata, Michio

    2015-01-26

    Long-chain fatty acids (FAs) with low water solubility require fatty-acid-binding proteins (FABPs) to transport them from cytoplasm to the mitochondria for energy production. However, the precise mechanism by which these proteins recognize the various lengths of simple alkyl chains of FAs with similar high affinity remains unknown. To address this question, we employed a newly developed calorimetric method for comprehensively evaluating the affinity of FAs, sub-Angstrom X-ray crystallography to accurately determine their 3D structure, and energy calculations of the coexisting water molecules using the computer program WaterMap. Our results clearly showed that the heart-type FABP (FABP3) preferentially incorporates a U-shaped FA of C10-C18 using a lipid-compatible water cluster, and excludes longer FAs using a chain-length-limiting water cluster. These mechanisms could help us gain a general understanding of how proteins recognize diverse lipids with different chain lengths.

  15. Regioselective, borinic acid-catalyzed monoacylation, sulfonylation and alkylation of diols and carbohydrates: expansion of substrate scope and mechanistic studies.

    PubMed

    Lee, Doris; Williamson, Caitlin L; Chan, Lina; Taylor, Mark S

    2012-05-16

    Synthetic and mechanistic aspects of the diarylborinic acid-catalyzed regioselective monofunctionalization of 1,2- and 1,3-diols are presented. Diarylborinic acid catalysis is shown to be an efficient and general method for monotosylation of pyranoside derivatives bearing three secondary hydroxyl groups (7 examples, 88% average yield). In addition, the scope of the selective acylation, sulfonylation, and alkylation is extended to 1,2- and 1,3-diols not derived from carbohydrates (28 examples); the efficiency, generality, and operational simplicity of this method are competitive with those of state-of-the-art protocols including the broadly applied organotin-catalyzed or -mediated reactions. Mechanistic details of the organoboron-catalyzed processes are explored using competition experiments, kinetics, and catalyst structure-activity relationships. These experiments are consistent with a mechanism in which a tetracoordinate borinate complex reacts with the electrophilic species in the turnover-limiting step of the catalytic cycle.

  16. Determination of methyl-, 2-hydroxyethyl- and 2-cyanoethylmercapturic acids as biomarkers of exposure to alkylating agents in cigarette smoke.

    PubMed

    Scherer, Gerhard; Urban, Michael; Hagedorn, Heinz-Werner; Serafin, Richard; Feng, Shixia; Kapur, Sunil; Muhammad, Raheema; Jin, Yan; Sarkar, Mohamadi; Roethig, Hans-Juergen

    2010-10-01

    Alkylating agents occur in the environment and are formed endogenously. Tobacco smoke contains a variety of alkylating agents or precursors including, among others, N-nitrosodimethylamine (NDMA), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), acrylonitrile and ethylene oxide. We developed and validated a method for the simultaneous determination of methylmercapturic acid (MMA, biomarker for methylating agents such as NDMA and NNK), 2-hydroxyethylmercapturic acid (HEMA, biomarker for ethylene oxide) and 2-cyanoethylmercapturic acid (CEMA, biomarker for acrylonitrile) in human urine using deuterated internal standards of each compound. The method involves liquid/liquid extraction of the urine sample, solid phase extraction on anion exchange cartridges, derivatization with pentafluorobenzyl bromide (PFBBr), liquid/liquid extraction of the reaction mixture and LC-MS/MS analysis with positive electrospray ionization. The method was linear in the ranges of 5.00-600, 1.00-50.0 and 1.50-900 ng/ml for MMA, HEMA and CEMA, respectively. The method was applied to two clinical studies in adult smokers of conventional cigarettes who either continued smoking conventional cigarettes, were switched to test cigarettes consisting of either an electrically heated cigarette smoking system (EHCSS) or having a highly activated carbon granule filter that were shown to have reduced exposure to specific smoke constituents, or stopped smoking. Urinary excretion of MMA was found to be unaffected by switching to the test cigarettes or stop smoking. Urinary HEMA excretion decreased by 46 to 54% after switching to test cigarettes and by approximately 74% when stopping smoking. Urinary CEMA excretion decreased by 74-77% when switching to test cigarettes and by approximately 90% when stopping smoking. This validated method for urinary alkylmercapturic acids is suitable to distinguish differences in exposure not only between smokers and nonsmokers but also between smoking of conventional and

  17. Nitrated Fatty Acids Reverse Cigarette Smoke-Induced Alveolar Macrophage Activation and Inhibit Protease Activity via Electrophilic S-Alkylation.

    PubMed

    Reddy, Aravind T; Lakshmi, Sowmya P; Muchumarri, Ramamohan R; Reddy, Raju C

    2016-01-01

    Nitrated fatty acids (NFAs), endogenous products of nonenzymatic reactions of NO-derived reactive nitrogen species with unsaturated fatty acids, exhibit substantial anti-inflammatory activities. They are both reversible electrophiles and peroxisome proliferator-activated receptor γ (PPARγ) agonists, but the physiological implications of their electrophilic activity are poorly understood. We tested their effects on inflammatory and emphysema-related biomarkers in alveolar macrophages (AMs) of smoke-exposed mice. NFA (10-nitro-oleic acid or 12-nitrolinoleic acid) treatment downregulated expression and activity of the inflammatory transcription factor NF-κB while upregulating those of PPARγ. It also downregulated production of inflammatory cytokines and chemokines and of the protease cathepsin S (Cat S), a key mediator of emphysematous septal destruction. Cat S downregulation was accompanied by decreased AM elastolytic activity, a major mechanism of septal destruction. NFAs downregulated both Cat S expression and activity in AMs of wild-type mice, but only inhibited its activity in AMs of PPARγ knockout mice, pointing to a PPARγ-independent mechanism of enzyme inhibition. We hypothesized that this mechanism was electrophilic S-alkylation of target Cat S cysteines, and found that NFAs bind directly to Cat S following treatment of intact AMs and, as suggested by in silico modeling and calculation of relevant parameters, elicit S-alkylation of Cys25 when incubated with purified Cat S. These results demonstrate that NFAs' electrophilic activity, in addition to their role as PPARγ agonists, underlies their protective effects in chronic obstructive pulmonary disease (COPD) and support their therapeutic potential in this disease.

  18. Extraction of manganese by alkyl monocarboxylic acid in a mixed extractant from a leaching solution of spent lithium-ion battery ternary cathodic material

    NASA Astrophysics Data System (ADS)

    Joo, Sung-Ho; Shin, Dongju; Oh, ChangHyun; Wang, Jei-Pil; Shin, Shun Myung

    2016-02-01

    We investigate the separation of manganese by an antagonistic effect from a leaching solution of ternary cathodic material of spent lithium-ion batteries that contain 11,400 mg L-1 Co, 11,700 mg L-1 Mn, 12,200 mg L-1 Ni, and 5300 mg L-1 Li using a mixture of alkyl monocarboxylic acid and di-(2-ethylhexyl)phosphoric acid extractants. pH isotherm, distribution coefficient, separation factor, McCabe-Thiele diagram, selective scrubbing, and countercurrent extraction tests are carried out to prove an antagonistic effect and to recover manganese using alkyl monocarboxylic in the mixed extractant. Slope analysis is used to determine the extraction mechanism between a mixture of extractants and valuable metals. An increasing concentration of alkyl monocarboxylic acid in the mixture of extractants results in a decrease in distribution coefficient of cobalt and manganese, however, the separation factor value (β(Mn/Co)) increases at pH 4.5. This is caused by slope analysis where alkyl monocarboxylic acid disrupts the extraction mechanism between di-(2-ethylhexyl)phosphoric acid and cobalt. Finally, continuous countercurrent extraction in a mini-plant test demonstrate the feasibility of manganese recovery from cobalt, nickel, and lithium.

  19. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acids C12-18, C18 unsaturated... Significant New Uses for Specific Chemical Substances § 721.3025 Fatty acids C12-18, C18 unsaturated, C12-18... chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  20. 40 CFR 721.3025 - Fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acids C12-18, C18 unsaturated... Significant New Uses for Specific Chemical Substances § 721.3025 Fatty acids C12-18, C18 unsaturated, C12-18... chemical substance identified generically as fatty acids C12-18, C18 unsaturated, C12-18 alkyl esters...

  1. Fast and selective sugar conversion to alkyl lactate and lactic acid with bifunctional carbon-silica catalysts.

    PubMed

    de Clippel, Filip; Dusselier, Michiel; Van Rompaey, Ruben; Vanelderen, Pieter; Dijkmans, Jan; Makshina, Ekaterina; Giebeler, Lars; Oswald, Steffen; Baron, Gino V; Denayer, Joeri F M; Pescarmona, Paolo P; Jacobs, Pierre A; Sels, Bert F

    2012-06-20

    A novel catalyst design for the conversion of mono- and disaccharides to lactic acid and its alkyl esters was developed. The design uses a mesoporous silica, here represented by MCM-41, which is filled with a polyaromatic to graphite-like carbon network. The particular structure of the carbon-silica composite allows the accommodation of a broad variety of catalytically active functions, useful to attain cascade reactions, in a readily tunable pore texture. The significance of a joint action of Lewis and weak Brønsted acid sites was studied here to realize fast and selective sugar conversion. Lewis acidity is provided by grafting the silica component with Sn(IV), while weak Brønsted acidity originates from oxygen-containing functional groups in the carbon part. The weak Brønsted acid content was varied by changing the amount of carbon loading, the pyrolysis temperature, and the post-treatment procedure. As both catalytic functions can be tuned independently, their individual role and optimal balance can be searched for. It was thus demonstrated for the first time that the presence of weak Brønsted acid sites is crucial in accelerating the rate-determining (dehydration) reaction, that is, the first step in the reaction network from triose to lactate. Composite catalysts with well-balanced Lewis/Brønsted acidity are able to convert the trioses, glyceraldehyde and dihydroxyacetone, quantitatively into ethyl lactate in ethanol with an order of magnitude higher reaction rate when compared to the Sn grafted MCM-41 reference catalyst. Interestingly, the ability to tailor the pore architecture further allows the synthesis of a variety of amphiphilic alkyl lactates from trioses and long chain alcohols in moderate to high yields. Finally, direct lactate formation from hexoses, glucose and fructose, and disaccharides composed thereof, sucrose, was also attempted. For instance, conversion of sucrose with the bifunctional composite catalyst yields 45% methyl lactate in

  2. Palladium-catalyzed difluoroalkylation of aryl boronic acids: a new method for the synthesis of aryldifluoromethylated phosphonates and carboxylic acid derivatives.

    PubMed

    Feng, Zhang; Min, Qiao-Qiao; Xiao, Yu-Lan; Zhang, Bo; Zhang, Xingang

    2014-02-03

    The palladium-catalyzed difluoroalkylation of aryl boronic acids with bromodifluoromethylphosphonate, bromodifluoroacetate, and further derivatives has been developed. This method provides a facile and useful access to a series of functionalized difluoromethylated arenes (ArCF2 PO(OEt)2 , ArCF2 CO2 Et, and ArCF2 CONR(1) R(2) ) that have important applications in drug discovery and development. Preliminary mechanistic studies reveal that a single electron transfer (SET) pathway may be involved in the catalytic cycle.

  3. Fluoride exposure from hydrofluoric acid in a motor gasoline alkylation unit

    SciTech Connect

    Brown, M.G.

    1985-11-01

    To assess the possible health risks associated with occupational exposure to gaseous fluoride, air and biological monitoring surveys were carried out at a motor gasoline alkylation unit within an oil refinery. Pre- and post-shift urinary fluoride measurements were obtained from 27 male operators and maintenance workers attached to the plant; personal fluoride-in-air monitoring was carried out simultaneously for 23 of these men. All readings were below NIOSH recommendations and Australia exposure standards. Significant exposure identified by changes in urine level during the shift could be demonstrated only in sub-groups of workers whose jobs involved higher routine exposures. No significant correlation between air levels and changes in urinary fluoride during the shift could be demonstrated. This survey indicates that the workers in this plant are not at risk of chronic fluorosis.

  4. Morphology Tailoring of Sulfonic Acid Functionalized Organosilica Nanohybrids for the Synthesis of Biomass-Derived Alkyl Levulinates.

    PubMed

    An, Sai; Song, Daiyu; Lu, Bo; Yang, Xia; Guo, Yi-Hang

    2015-07-20

    Morphology evolution of sulfonic acid functionalized organosilica nanohybrids (Si(Et)Si-Pr/ArSO3 H) with a 1D tubular structure (inner diameter of ca. 5 nm), a 2D hexagonal mesostructure (pore diameter of ca. 5 nm), and a 3D hollow spherical structure (shell thickness of 2-3 nm and inner diameter of ca. 15 nm) was successfully realized through P123-templated sol-gel cocondensation strategies and fine-tuning of the acidity followed by aging or a hydrothermal treatment. The Si(Et)Si-Pr/ArSO3 H nanohybrids were applied in synthesis of alkyl levulinates from the esterification of levulinic acid and ethanolysis of furfural alcohol. Hollow spherical Si(Et)Si-Pr/ArSO3 H and hexagonal mesoporous analogues exhibited the highest and lowest catalytic activity, respectively, among three types of nanohybrids; additionally, the activity was influenced by the -SO3 H loading. The activity differences are explained in terms of different Brønsted acid and textural properties, reactant/product diffusion, and mass transfer rate, as well as accessibility of -SO3 H sites to the reactant molecules. The reusability of the nanohybrids was also evaluated.

  5. Asymmetric direct α-alkylation of 2-oxindoles with Michler's hydrol catalyzed by bis-cinchona alkaloid-Brønsted acid via an SN1-type pathway.

    PubMed

    Zhang, Tao; Qiao, Zhen; Wang, Yan; Zhong, Nengjun; Liu, Li; Wang, Dong; Chen, Yong-Jun

    2013-02-25

    An enantioselective direct α-alkylation of 2-oxindoles with Michler's hydrol via an S(N)1-type pathway in the non-covalent activation mode using the bis-cinchona alkaloid and Brønsted acid as a co-catalyst was developed and good to high yields and enantioselectivities were obtained.

  6. Lewis acid-catalyzed Friedel-Crafts alkylations of 3-hydroxy-2-oxindole: an efficient approach to the core structure of azonazine.

    PubMed

    Ghosh, Santanu; Kinthada, Lakshmana K; Bhunia, Subhajit; Bisai, Alakesh

    2012-10-18

    A Lewis acid catalyzed Friedel-Crafts reaction of electron rich aromatics with 3-alkyl-3-hydroxy-2-oxindole (5) has been developed. The methodology provides a straightforward access to the core of azonazine (2) sharing an all-carbon quaternary stereocenter at the tetracyclic ring junction.

  7. Enantioselective Friedel-Crafts alkylation of indole derivatives catalyzed by new Yb(OTf)3-pyridylalkylamine complexes as chiral Lewis acids.

    PubMed

    Grach, Guillaume; Dinut, Aurelia; Marque, Sylvain; Marrot, Jérôme; Gil, Richard; Prim, Damien

    2011-01-21

    New Yb(OTf)(3)-pyridylalkylamine complexes have been employed as chiral Lewis acids in the enantioselective Friedel-Crafts alkylation of indole derivatives with trifluoropyruvates. The influence of the substituents as well as the configuration of the ligands have been studied and allowed us to reach enantiomeric excesses up to 83%.

  8. General approach for the stereocontrolled construction of the beta-lactam ring in amino acid-derived 4-alkyl-4-carboxy-2-azetidinones.

    PubMed

    Gerona-Navarro, Guillermo; García-López, M Teresa; González-Muñiz, Rosario

    2002-05-31

    The first general approach toward the asymmetric synthesis of 4-alkyl-4-carboxy-2-azetidinones derived from amino acids is described. The stereoselective construction of the beta-lactam ring was achieved through base-mediated intramolecular cyclization of the corresponding N(alpha)-chloroacetyl derivatives bearing (+)- or (-)-10-(N,N-dicyclohexylsulfamoyl)isoborneol as chiral auxiliary (ee up to 82%).

  9. Phosphonate-hydroxyapatite hybrid compounds prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Agougui, H.; Aissa, A.; Maggi, S.; Debbabi, M.

    2010-12-01

    Calcium hydroxyapatite (CaHAp) was prepared in the presence of two alkylphosphonates, the tert-butyl phosphonic acid TBPOH and the 2-carboxyletylphosphonic acid 2-CEPA, by hydrothermal method at 120 °C for 15 h. The modification of hydroxyapatite by grafting organic moieties is confirmed by IR and NMR MAS ( 1H and 31P) spectroscopy and chemical analysis. X-ray powder diffraction patterns show that the incorporation of organic moieties induces a significant loss of the material crystallinity and a clear increase of the unit cell lattice parameter a as function of 2-CEPA grafting rate. The specific surface area (SSA) increases with increasing phosphonate amount especially for 2-CEPA. All techniques show the lower reactivity of TBPOH due to the steric effects of tert-butyl, whereas the 2-CEPA with a linear chain and double acidic functions is more reactive and can replace the OH - groups of the apatitic structure.

  10. Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

    SciTech Connect

    Jiang, Tingshun Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

    2014-10-15

    Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH{sub 3}-TPD and N{sub 2} physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)–MCM-48 samples, SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO{sub 4}{sup 2−}/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h{sup −1} and the reaction temperature is 140 °C. - Highlights: • Sulfuric acid functional mesoporous solid acid catalysts were prepared via impregnation method. • The alkylation of phenol with tert-butyl alcohol was carried out over these solid acid catalysts. • The catalytic activity of SO{sub 4}{sup 2−}/Zr-MCM-48-25 catalyst is much higher than that of the others. • A maximum phenol conversion of 91.6% was achieved under optimum reaction conditions for SO{sub 4}{sup 2−}/Zr-MCM-48-25.

  11. Hydrogen-Bond Directed Regioselective Pd-Catalyzed Asymmetric Allylic Alkylation: The Construction of Chiral α-Amino Acids with Vicinal Tertiary and Quaternary Stereocenters.

    PubMed

    Wei, Xuan; Liu, Delong; An, Qianjin; Zhang, Wanbin

    2015-12-04

    A Pd-catalyzed asymmetric allylic alkylation of azlactones with 4-arylvinyl-1,3-dioxolan-2-ones was developed, providing "branched" chiral α-amino acids with vicinal tertiary and quaternary stereocenters, in high yields and with excellent selectivities. Mechanistic studies revealed that the formation of a hydrogen bond between the Pd-allylic complex and azlactone isomer is responsible for the excellent regioselectivities. This asymmetric alkylation can be carried out on a gram scale without a loss of catalytic efficiency, and the resulting product can be further transformed to a chiral azetidine in two simple steps.

  12. Molecular design of boronic acid-functionalized squarylium cyanine dyes for multiple discriminant analysis of sialic acid in biological samples: selectivity toward monosaccharides controlled by different alkyl side chain lengths.

    PubMed

    Ouchi, Kazuki; Colyer, Christa L; Sebaiy, Mahmoud; Zhou, Jin; Maeda, Takeshi; Nakazumi, Hiroyuki; Shibukawa, Masami; Saito, Shingo

    2015-02-03

    We designed a new series of boronic acid-functionalized squarylium cyanine dyes (SQ-BA) with different lengths of alkyl chain residues, suitable for multiple discriminant analysis (MDA) of sialic acid (Neu5Ac) in biological samples. The SQ-BA dyes form aggregates based on hydrophobic interactions, which result in quenched fluorescence in aqueous solutions. When the boronic acid binds with saccharides, the fluorescence intensity increases as a result of dissociation to the emissive monomeric complex. We inferred that different dye aggregate structures (H-aggregates and J-aggregates) were induced depending on the alkyl chain length, so that monosaccharides would be recognized in different ways (especially, multipoint interaction with J-aggregates). A distinctive emission enhancement of SQ-BA dyes with shorter-alkyl-chains in the presence of Neu5Ac was observed (2.4-fold fluorescence enhancement; with formation constant 10(1.7) M(-1)), with no such enhancement for SQ-BA dyes with longer-alkyl-chain. In addition, various enhancement factors for other monosaccharides were observed depending on the alkyl chain length. Detailed thermodynamic and NMR studies of the SQ-BA complexes revealed the unique recognition mechanism: the dye aggregate with a shorter-alkyl-chain causes the slipped parallel structure and forms a stable 2:1 complex with Neu5Ac, as distinct from longer-alkyl-chain dyes, which form a 1:1 monomeric complex. MDA using the four SQ-BA dyes was performed for human urine samples, resulting in the successful discrimination between normal and abnormal Neu5Ac levels characteristic of disease. Thus, we successfully controlled various responses to similar monosaccharides with a novel approach that chemically modified not the boronic acid moiety itself but the length of the alkyl chain residue attached to the dye in order to generate specificity.

  13. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  14. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  15. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  16. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  17. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  18. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  19. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  20. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  1. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  2. 40 CFR 721.9460 - Tall oil fatty acids, reaction products with polyamines, alkyl substituted.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Tall oil fatty acids, reaction... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9460 Tall oil fatty acids, reaction... reporting. (1) The chemical substance identified generically as tall oil fatty acids, reaction products...

  3. Outlook for the U. S. alkylation industry

    SciTech Connect

    Felten, J.R.; Bradshaw, T.; McCarthy, K. )

    1994-01-01

    Alkylation has long been recognized in the refining industry as one of the best options to convert refinery olefins into valuable, clean, high octane blending components. In fact, refinery alkylation is a preferred source of blending stocks for reformulated gasoline. However, the hydrofluoric acid (HF) alkylation process and, to a lesser extent, the sulfuric acid (SA) process have come under increasing pressure in the US due to safety and environmental concerns. This paper examines the current outlook for the US alkylation industry including: key trends and driving forces in the industry, the impact of environmental issues on both HF and SA alkylation, US alkylation supply/demand forecast including the outlook for oxygenates, how US refines will respond to the increased demand and restricted supply for alkylates, and the outlook for new solid acid alkylation (SAC) technology.

  4. Enhanced production of short-chain fatty acid from food waste stimulated by alkyl polyglycosides and its mechanism.

    PubMed

    Zhao, Jianwei; Yang, Qi; Li, Xiaoming; Wang, Dongbo; Luo, Kun; Zhong, Yu; Xu, Qiuxiang; Zeng, Guangming

    2015-12-01

    Short-chain fatty acids (SCFAs) are the valuable products derived from the anaerobic fermentation of organic solid waste. However, SCFAs yield was limited by the worse solubilization and hydrolysis of particulate organic matter, and rapid consumption of organic acid by methanogens. In this study, an efficient and green strategy, i.e. adding biosurfactant alkyl polyglycosides (APG) into anaerobic fermentation system, was applied to enhance SCFAs production from food waste. Experimental results showed that APG not only greatly improved SCFAs production but also shortened the fermentation time for the maximum SCFAs accumulation. The SCFAs yield at optimal APG dosage 0.2g/g TS (total solid) reached 37.2g/L, which was 3.1-fold of that in blank. Meanwhile, the time to accumulate the maximum SCFAs in the presence of APG was shortened from day 14 to day 6. The activities of key enzymes such as hydrolytic and acid-forming enzymes were greatly promoted due to the presence of APG. These results demonstrated that the enhanced mechanism of SCFAs production should be attributed to the acceleration of solubilization and hydrolysis, enhancement of acidification and inhibition of methanogenesis by APG.

  5. Molecular Anchors for Self-Assembled Monolayers on ZnO: A Direct Comparison of the Thiol and Phosphic Acid Moieties

    SciTech Connect

    Perkins, C. L.

    2009-01-01

    Two of the most promising schemes for attaching organic molecules to metal oxides are based on the chemistry of the thiol and phosphonic acid moieties. We have made a direct comparison of the efficacy of these two molecular anchors on zinc oxide by comparing the chemical and physical properties of n-hexane derivatives of both. The surface properties of polycrystalline ZnO thin films and ZnO(000)-O crystals modified with 1-hexanethiol and 1-hexanephosphonic acid were examined with a novel quartz crystal microbalance (QCM)-based flow cell reactor, angle-resolved and temperature-dependent photoelectron spectroscopy, and contact angle measurements. A means of using ammonium chloride as a probe of molecule-ZnO interactions is introduced and used to ascertain the relative quality of self-assembled monolayers (SAMs) based on thiols and phosphonic acids. QCM data shows that a phosphonic acid-anchored alkyl chain only six carbons long can provide significant corrosion protection for ZnO against Bronsted acids, reducing the etch rate relative to the bare ZnO surface by a factor of more than nine. In contrast, we find that monolayers from the analogous molecule hexanethiol are more defective as revealed by their higher ionic permeability and lower hydrophobicity. Substrate attenuation X-ray photoelectron spectroscopy (XPS) experiments were used to determine the thickness of SAMs formed by the two hexane derivatives and it was found that SAMs from phosphonic acids were approximately twice as thick as those formed by hexanethiol. The thermal stability of the two linking groups was also explored and we find that previous claims of highly stable alkanethiolate monolayers on ZnO are suspect. Taken as a whole, our results indicate that the phosphonic acid moiety is preferred over thiols for the attachment of short alkyl groups to ZnO.

  6. Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 C-H bond and Lewis acid catalysis.

    PubMed

    Wang, Ming-Zhong; Zhou, Cong-Ying; Wong, Man-Kin; Che, Chi-Ming

    2010-05-17

    Ruthenium porphyrins (particularly [Ru(2,6-Cl(2)tpp)CO]; tpp=tetraphenylporphinato) and RuCl(3) can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82% based on 60-95% substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron-withdrawing or electron-donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N-arylindoles to 3-{[(N-aryl-N-alkyl)amino]methyl}indoles (yield: up to 82%, conversion: up to 95%) and the alkylation of N-alkyl or N-H indoles to 3-[p-(dialkylamino)benzyl]indoles (yield: up to 73%, conversion: up to 92%). A tentative reaction mechanism involving two pathways is proposed: an iminium ion intermediate may be generated by oxidation of an sp(3) C-H bond of the alkylated aniline by an oxoruthenium species; this iminium ion could then either be trapped by an N-arylindole (pathway A) or converted to formaldehyde, allowing a subsequent three-component coupling reaction of the in situ generated formaldehyde with an N-alkylindole and an aniline in the presence of a Lewis acid catalyst (pathway B). The results of deuterium-labeling experiments are consistent with the alkylation of N-alkylindoles via pathway B. The relative reaction rates of [Ru(2,6-Cl(2)tpp)CO]-catalyzed oxidative coupling reactions of 4-X-substituted N,N-dimethylanilines with N-phenylindole (using tBuOOH as oxidant), determined through competition experiments, correlate linearly with the substituent constants sigma (R(2)=0.989), giving a rho value of -1.09. This rho value and the magnitudes of the intra- and intermolecular deuterium isotope effects (k(H)/k(D)) suggest that electron transfer most likely occurs during the initial stage of the oxidation of 4-X-substituted N,N-dimethylanilines. Ruthenium-catalyzed three-component reaction of N-alkyl/N-H indoles

  7. Molecular Basis for Resistance Against Phosphonate Antibiotics and Herbicides

    PubMed Central

    Chekan, Jonathan R.; Cogan, Dillon P.; Nair, Satish K.

    2015-01-01

    Research in recent years have illuminated data on the mechanisms and targets of phosphonic acid antibiotics and herbicides, including fosfomycin, glyphosate, fosmidomycin and FR900098. Here we review the current state of knowledge of the structural and biochemical characterization of resistance mechanisms against these bioactive natural products. Advances in the understanding of these resistance determinants have spurred knowledge-based campaigns aimed towards the design of derivatives that retain biological activity but are less prone to tolerance. PMID:26811741

  8. Concentrations of volatile 4-alkyl-branched fatty acids in sheep and goat milk and dairy products.

    PubMed

    Kaffarnik, Stefanie; Kayademir, Yasemin; Heid, Carolina; Vetter, Walter

    2014-11-01

    Goat and sheep milk and dairy products thereof are characterized by a strong and unique flavor. In this context, the volatile minor fatty acid 4-ethyloctanoic acid plays a prominent role along with 4-methyloctanoic acid when both are present in free form. Using a novel GC/MS method in the selected ion-monitoring mode, previously developed for sheep subcutaneous adipose tissue, we were able to analyze the total concentrations of these flavor-relevant minor fatty acids as methyl esters in goat and sheep milk as well as in their products. Differences between the concentrations and ratios of 4-methyloctanoic acid and 4-ethyloctanoic acid in goat milk (n = 4), goat cheese (n = 4), sheep milk (n = 2), and sheep cheese (n = 4) were observed. Goat milk and cheese resulted in higher concentrations for both fatty acids (190 to 480 μg/g milk fat) and smaller 4-Me-8:0 to 4-Et-8:0 ratios (1.4 to 2.7) compared to sheep milk and cheese (78 to 220 μg/g milk fat; 4-Me-8:0 to 4-Et-8:0 ratio: 15 to 42). In all samples, the concentration of 4-Me-8:0 exceeded the one of 4-Et-8:0. However, due to its lower flavor threshold value the contribution of 4-Et-8:0 to the flavor was generally >76%. The calculated flavor values were >1400 for goat milk and cheeses and >200 for sheep milk and cheeses. In goat milk and its products, only a proportion of <0.1% 4-alkyl-branched fatty acids present in free form in the goat milk and <0.5% in the sheep samples would be sufficient to generate the characteristic goaty flavor. Parameters that promote or prevent the release of 4-Me-8:0, and especially 4-Et-8:0, will be decisive for the flavor in the resulting dairy product.

  9. Crystal structures of the apo form and a complex of human LMW-PTP with a phosphonic acid provide new evidence of a secondary site potentially related to the anchorage of natural substrates.

    PubMed

    Fonseca, Emanuella M B; Trivella, Daniela B B; Scorsato, Valéria; Dias, Mariana P; Bazzo, Natália L; Mandapati, Kishore R; de Oliveira, Fábio L; Ferreira-Halder, Carmen V; Pilli, Ronaldo A; Miranda, Paulo C M L; Aparicio, Ricardo

    2015-08-01

    Low molecular weight protein tyrosine phosphatases (LMW-PTP, EC 3.1.3.48) are a family of single-domain enzymes with molecular weight up to 18 kDa, expressed in different tissues and considered attractive pharmacological targets for cancer chemotherapy. Despite this, few LMW-PTP inhibitors have been described to date, and the structural information on LMW-PTP druggable binding sites is scarce. In this study, a small series of phosphonic acids were designed based on a new crystallographic structure of LMW-PTP complexed with benzylsulfonic acid, determined at 2.1Å. In silico docking was used as a tool to interpret the structural and enzyme kinetics data, as well as to design new analogs. From the synthesized series, two compounds were found to act as competitive inhibitors, with inhibition constants of 0.124 and 0.047 mM. We also report the 2.4Å structure of another complex in which LMW-PTP is bound to benzylphosphonic acid, and a structure of apo LMW-PTP determined at 2.3Å resolution. Although no appreciable conformation changes were observed, in the latter structures, amino acid residues from an expression tag were found bound to a hydrophobic region at the protein surface. This regions is neighbored by positively charged residues, adjacent to the active site pocket, suggesting that this region might be not a mere artefact of crystal contacts but an indication of a possible anchoring region for the natural substrate-which is a phosphorylated protein.

  10. Synthesis of Li-Al layered double hydroxide intercalated with amino tris(methylene phosphonic acid) and kinetic and equilibrium studies of the uptake of Nd3+ and Sr2+ ions

    NASA Astrophysics Data System (ADS)

    Kameda, Tomohito; Shinmyou, Tetsu; Yoshioka, Toshiaki

    2016-03-01

    A Li-Al layered double hydroxide intercalated with amino tris(methylene phosphonic acid) (AMP·Li-Al LDH) was synthesized by the drop-wise addition of an Al-containing solution to a Li-AMP solution at a constant pH of 8.0. The AMP·Li-Al LDH was found to take up Nd3+ and Sr2+ ions from aqueous solutions; this phenomenon was attributable to the metal-chelating functionality of the AMP ions in the interlayers of the AMP·Li-Al LDH. Further, the AMP·Li-Al LDH was found to take up Nd3+ ions preferentially than Sr2+ ions. This was attributable to the stability of the Nd-AMP complex being higher than that of the Sr-AMP complex. The mass-transfer-controlled shrinking-core model could describe the uptake behavior better than the surface-reaction-control model. The AMP ions in the AMP·Li-Al LDH interlayers rapidly formed chelate complexes with the Nd3+ or Sr2+ ions. As a result, the transfer of Nd3+ and Sr2+ ions through the product layer was the rate-limiting step. Furthermore, this reaction could be explained by a Langmuir-type adsorption mechanism, indicating that it involved chemical adsorption; this was consistent with the formation of chelate complexes between Nd3+ and Sr2+ ions and the AMP ions in the interlayers of the AMP·Li-Al LDH.

  11. Nanolayer formation on titanium by phosphonated gelatin for cell adhesion and growth enhancement

    PubMed Central

    Zhou, Xiaoyue; Park, Shin-Hye; Mao, Hongli; Isoshima, Takashi; Wang, Yi; Ito, Yoshihiro

    2015-01-01

    Phosphonated gelatin was prepared for surface modification of titanium to stimulate cell functions. The modified gelatin was synthesized by coupling with 3-aminopropylphosphonic acid using water-soluble carbodiimide and characterized by 31P nuclear magnetic resonance and gel permeation chromatography. Circular dichroism revealed no differences in the conformations of unmodified and phosphonated gelatin. However, the gelation temperature was changed by the modification. Even a high concentration of modified gelatin did not form a gel at room temperature. Time-of-flight secondary ion mass spectrometry showed direct bonding between the phosphonated gelatin and the titanium surface after binding. The binding behavior of phosphonated gelatin on the titanium surface was quantitatively analyzed by a quartz crystal microbalance. Ellipsometry showed the formation of a several nanometer layer of gelatin on the surface. Contact angle measurement indicated that the modified titanium surface was hydrophobic. Enhancement of the attachment and spreading of MC-3T3L1 osteoblastic cells was observed on the phosphonated gelatin-modified titanium. These effects on cell adhesion also led to growth enhancement. Phosphonation of gelatin was effective for preparation of a cell-stimulating titanium surface. PMID:26366080

  12. Nanolayer formation on titanium by phosphonated gelatin for cell adhesion and growth enhancement.

    PubMed

    Zhou, Xiaoyue; Park, Shin-Hye; Mao, Hongli; Isoshima, Takashi; Wang, Yi; Ito, Yoshihiro

    2015-01-01

    Phosphonated gelatin was prepared for surface modification of titanium to stimulate cell functions. The modified gelatin was synthesized by coupling with 3-aminopropylphosphonic acid using water-soluble carbodiimide and characterized by (31)P nuclear magnetic resonance and gel permeation chromatography. Circular dichroism revealed no differences in the conformations of unmodified and phosphonated gelatin. However, the gelation temperature was changed by the modification. Even a high concentration of modified gelatin did not form a gel at room temperature. Time-of-flight secondary ion mass spectrometry showed direct bonding between the phosphonated gelatin and the titanium surface after binding. The binding behavior of phosphonated gelatin on the titanium surface was quantitatively analyzed by a quartz crystal microbalance. Ellipsometry showed the formation of a several nanometer layer of gelatin on the surface. Contact angle measurement indicated that the modified titanium surface was hydrophobic. Enhancement of the attachment and spreading of MC-3T3L1 osteoblastic cells was observed on the phosphonated gelatin-modified titanium. These effects on cell adhesion also led to growth enhancement. Phosphonation of gelatin was effective for preparation of a cell-stimulating titanium surface.

  13. [EFfect of quinazolone-alkyl-carboxylic acid derivatives on the transmembrane Ca2+ ion flux mediated by AMPA receptors].

    PubMed

    Szárics, Eva; LaszTóczi, Bálint; Nyikos, Lajos; Barabás, Péter; Kovács, Ilona; Skuban, Nina; Nagy, Péter I; Kökösi, József; Takácsné, Novák Krisztina; Kardos, Julianna

    2002-01-01

    The excitatory neurotransmitter, Glu, plays a crucial role in many sensory and motor functions as well as in brain development, learning and memory and it is also involved in the pathogenesis of a number of neurological disorders, including epilepsy, Alzheimer's and Parkinson's diseases. Therefore, the study of Glu receptors (GluRs) is of therapeutical importance. We showed here by fluorescence monitoring of transmembrane Ca2+ ion fluxes in response to (S)-alpha-amino-3-hidroxi-5-metil-4-izoxazol propionic acid ((S)-AMPA) on the time scale of 0.00004-10 s that Ca2+ ion influx proceeds through faster and slower desensitizing receptors. Pharmacological isolation of the slower and faster desensitizing AMPA receptor was possible by fluorescence monitoring of Ca2+ ion translocation in response to (S)-AMPA in the presence and absence of various 2-methyl-4-oxo-3H-quinazoline-3-alkyl-carboxilic acid derivatives (Qxs): the acetic acid Q1 inhibits the slower desensitizing receptor response specifically, while the acetyl-piperidine Q5 is a more potent inhibitor of the faster desensitizing receptor response. In addition, spontaneous interictal activity, as induced by high [K+] conditions in hippocampal slices, was reduced significantly by Q5, suggesting a possible anticonvulsant property of Q5. Substitutions of Qxs into the GluR2 S1S2 binding core were consistent with their effect by causing variable degree of S1S2 bridging interaction as one of the main determinants of AMPA receptor agonist activity. The exploitation of differences between similar receptors will be important in the development and use of drugs with high pharmacological specificity.

  14. Stabilization of alkylated azacrown ether by fatty acid at the air-water interface.

    PubMed

    Zarbakhsh, Ali; Campana, Mario; Webster, John R P; Wojciechowski, Kamil

    2010-12-07

    The adsorbed amount of partially deuterated dihexadecyl-diaza-18-crown-6 ether (d-ACE16) in the presence of different chain length fatty acids as a function of surface pressure was determined by neutron reflectometry technique. The highest adsorbed amount of the azacrown ether was observed for the mixture of ACE16 with hexadecanoic (palmitic) acid, pointing to the importance of chain length matching between the two species for optimum stabilization of the mixed monolayer. The contrast variation technique was used to estimate the contribution to the total adsorbed amount from stearic acid and ACE16. It was found that the mixed Langmuir monolayer is stable against dissolution up to a surface pressure of 20 mN m(-1). Above this pressure, however, the spread and adsorbed amounts start to deviate, indicative of partial dissolution into the aqueous subphase. The consequences of this behavior for the transport of metal ions through the interfaces of permeation liquid membranes (PLMs) are discussed.

  15. Alkyl halide-free heteroatom alkylation and epoxidation facilitated by a recyclable polymer-supported oxidant for the in-flow preparation of diazo compounds.

    PubMed

    Nicolle, Simon M; Hayes, Christopher J; Moody, Christopher J

    2015-03-16

    Highly reactive metal carbenes, generated from simple ketones via diazo compounds, including diazo-amides and -phosphonates, using a recyclable reagent in-flow, are transient but versatile electrophiles for heteroatom alkylation reactions and for epoxide formation. The method produces no organic waste, with the only by-products being water, KI and nitrogen, without the attendant hazards of isolation of intermediate diazo compounds.

  16. Extraction of perfluorinated alkyl acids from human serum for determination of the combined xenoestrogenic transactivity: a method development.

    PubMed

    Bjerregaard-Olesen, Christian; Bossi, Rossana; Bech, Bodil Hammer; Bonefeld-Jørgensen, Eva Cecilie

    2015-06-01

    Humans are exposed to perfluorinated alkyl acids (PFAAs) through food, drinking water, consumer products, dust, etc. The human metabolism and excretion of the long-chain PFAAs is slow with half-lives up to 8.8years. Studies suggest that the PFAAs are potential endocrine-disrupting compounds that might affect human health. We developed a method for extraction of PFAAs from human serum with simultaneous removal of endogenous sex hormones. The developed method includes solid phase extraction, liquid/liquid extraction, HPLC fractionation and weak anion exchange. The method was validated by extraction of seven persistent PFAAs spiked to human male serum obtaining mean recoveries between 49.6% and 78.6%. Using an estrogen receptor (ER) transactivation luciferase reporter gene assay, analysis of the extracted PFAA serum fraction from three pregnant women showed the ER-active endogenous hormones were removed. The developed method was further documented by extraction of the PFAAs from the serum of 18 Danish pregnant women. The PFAA fraction from three of the 18 samples significantly induced the ER-transactivity. Upon co-exposure with the natural ER-ligand 17β-estradiol (E2), 17 of the 18 PFAA fractions caused a significant further increase of the E2 induced ER-transactivity. In conclusion, we developed a method to extract PFAAs from human serum, and the method documentation suggested that PFAAs at the levels found in human serum can transactivate the ER.

  17. Alkyl polyglucose enhancing propionic acid enriched short-chain fatty acids production during anaerobic treatment of waste activated sludge and mechanisms.

    PubMed

    Luo, Jingyang; Feng, Leiyu; Chen, Yinguang; Sun, Han; Shen, Qiuting; Li, Xiang; Chen, Hong

    2015-04-15

    Adding alkyl polyglucose (APG) into an anaerobic treatment system of waste activated sludge (WAS) was reported to remarkably improve the production of short-chain fatty acids (SCFAs), especially propionic acid via simultaneously accelerating solubilization and hydrolysis, enhancing acidification, inhibiting methanogenesis and balancing carbon to nitrogen (C/N) ratio of substrate. Not only the production of SCFAs, especially propionic acid, was significantly improved by APG, but also the feasible operation time was shortened. The SCFAs yield at 0.3 g APG per gram of total suspended solids (TSS) within 4 d was 2988 ± 60 mg chemical oxygen demand (COD) per liter, much higher than that those from sole WAS or sole WAS plus sole APG. The corresponding yield of propionic acid was 1312 ± 25 mg COD/L, 7.9-fold of sole WAS. Mechanism investigation showed that during anaerobic treatment of WAS in the presence of APG both the solubilization and hydrolysis were accelerated and the acidification was enhanced, while the methanogenesis was inhibited. Moreover, the activities of key enzymes involved in WAS hydrolysis and acidification were improved through the adjustment of C/N ratio of substrates with APG. The abundance of microorganisms responsible for organic compounds hydrolysis and SCFAs production was also observed to be greatly enhanced with APG via 454 high-throughput pyrosequencing analysis.

  18. Chiral phosphoric acid catalyzed highly enantioselective Friedel-Crafts alkylation reaction of C3-substituted indoles to β,γ-unsaturated α-ketimino esters.

    PubMed

    Bi, Bo; Lou, Qin-Xin; Ding, Yu-Yang; Chen, Sheng-Wei; Zhang, Sha-Sha; Hu, Wen-Hui; Zhao, Jun-Ling

    2015-02-06

    A highly enantioselective C2 Friedel-Crafts alkylation reaction of 3-substituted indoles to β,γ-unsaturated α-ketimino esters has been developed. This reaction was efficiently catalyzed by a chiral phosphoric acid catalyst. The corresponding C2-substituted indole derivatives, bearing an α-ketimino ester motif, were obtained in moderate to high yields (up to 93%) and with high enantioselectivities (up to >99% ee).

  19. Electrochemical method for producing a biodiesel mixture comprising fatty acid alkyl esters and glycerol

    DOEpatents

    Lin, YuPo J; St. Martin, Edward J

    2013-08-13

    The present invention relates to an integrated method and system for the simultaneous production of biodiesel from free fatty acids (via esterification) and from triglycerides (via transesterification) within the same reaction chamber. More specifically, one preferred embodiment of the invention relates to a method and system for the production of biodiesel using an electrodeionization stack, wherein an ion exchange resin matrix acts as a heterogeneous catalyst for simultaneous esterification and transesterification reactions between a feedstock and a lower alcohol to produce biodiesel, wherein the feedstock contains significant levels of free fatty acid. In addition, because of the use of a heterogeneous catalyst, the glycerol and biodiesel have much lower salt concentrations than raw biodiesel produced by conventional transesterification processes. The present invention makes it much easier to purify glycerol and biodiesel.

  20. Polyimides with pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1982-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  1. Hollow cobalt phosphonate spherical hybrid as high-efficiency Fenton catalyst

    NASA Astrophysics Data System (ADS)

    Zhu, Yun-Pei; Ren, Tie-Zhen; Yuan, Zhong-Yong

    2014-09-01

    Organic-inorganic hybrid of cobalt phosphonate hollow nanostructured spheres were prepared in a water-ethanol system through a mild hydrothermal process in the absence of any templates using diethylenetriamine penta(methylene phosphonic acid) as bridging molecule. SEM, TEM and N2 sorption characterization confirmed a hollow spherical micromorphology with well-defined porosity. The structure and chemical states of the hybrid materials were investigated by FT-IR, XPS and thermogravimetric analysis, revealing the homogeneous integrity of inorganic and organic units inside the network. As a heterogeneous catalyst, hollow cobalt phosphonate material exhibited considerable catalytic oxidizing decomposition of methylene blue with sulfate radicals as compared to cobalt phosphonate nanoparticles synthesized in single water system, which could be attributed to enhanced mass transfer and high surface area for the hollow material. Some operational parameters, including pH and reaction temperature, were found to influence the oxidation process. The present results suggest that cobalt phosphonate material can perform as an efficient heterogeneous catalyst for the degradation of organic contaminants, providing insights into the rational design and development of alternative catalysts for wastewater treatment.Organic-inorganic hybrid of cobalt phosphonate hollow nanostructured spheres were prepared in a water-ethanol system through a mild hydrothermal process in the absence of any templates using diethylenetriamine penta(methylene phosphonic acid) as bridging molecule. SEM, TEM and N2 sorption characterization confirmed a hollow spherical micromorphology with well-defined porosity. The structure and chemical states of the hybrid materials were investigated by FT-IR, XPS and thermogravimetric analysis, revealing the homogeneous integrity of inorganic and organic units inside the network. As a heterogeneous catalyst, hollow cobalt phosphonate material exhibited considerable

  2. Synthesis and Structural Studies of Calcium and Magnesium Phosphinate and Phosphonate Compounds

    NASA Astrophysics Data System (ADS)

    Bampoh, Victoria Naa Kwale

    The work presented herein describes synthetic methodologies leading to the design of a wide array of magnesium and calcium based phosphinate and phosphonates with possible applications as bone scaffolding materials or additives to bone cements. The challenge to the chemistry of the alkaline earth phosphonate target compounds includes poor solubility of compounds, and poorly understood details on the control of the metal's coordination environment. Hence, less is known on phosphonate based alkaline earth metal organic frameworks as compared to transition metal phosphonates. Factors governing the challenges in obtaining crystalline, well-defined magnesium and calcium solids lie in the large metal diameters, the absence of energetically available d-orbitals to direct metal geometry, as well as the overall weakness of the metal-ligand bonds. A significant part of this project was concerned with the development of suitable reaction conditions to obtain X-ray quality crystals of the reaction products to allow for structural elucidation of the novel compounds. Various methodologies to aid in crystal growth including hydrothermal methods and gel crystallization were employed. We have used phosphinate and phosphonate ligands with different number of phosphorus oxygen atoms as well as diphosphonates with different linker lengths to determine their effects on the overall structural features. An interesting correlation is observed between the dimensionality of products and the increasing number of donor oxygen atoms in the ligands as we progress from phosphinic acid to the phosphorous acids. As an example, monophosphinate ligand only yielded one-dimensional compounds, whereas the phosphonates crystallize as one and two-dimensional compounds, and the di- and triphosphonate based compounds display two or three-dimensional geometries. This thesis provides a selection of calcium and magnesium compounds with one-dimensional geometry, as represented in a calcium phosphinate to novel

  3. Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina

    NASA Technical Reports Server (NTRS)

    Bangma, Jacqueline T.; Bowden, John A.; Brunell, Arnold M.; Christie, Ian; Finnell, Brendan; Guillette, Matthew P.; Jones, Martin; Lowers, Russell H.; Rainwater, Thomas R.; Reiner, Jessica L.; Wilkinson, Philip M.; Guillette, Louis J., Jr.

    2016-01-01

    This study aimed to quantitate fourteen perfluoroalkyl acids (PFAAs) in 125 adult American alligators at twelve sites across the southeastern US. Of those fourteen PFAAs, nine were detected in 65% - 100% of the samples: PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTriA, PFTA, PFHxS, and PFOS. Males (across all sites) showed significantly higher concentrations of four PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at Merritt Island National Wildlife Refuge and Kiawah Nature Conservancy both exhibited some of the highest PFOS concentrations (medians 99.5 ng/g and 55.8 ng/g respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length (SVL) were observed in both sexes suggesting PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. This study is the first to report PFAAs in American alligators, reveals potential PFAA hot spots in Florida and South Carolina, and provides and additional contaminant of concern when assessing anthropogenic impacts on ecosystem health.

  4. Lipase-catalyzed enantioselective synthesis of (R,R)-lactide from alkyl lactate to produce PDLA (poly D-lactic acid) and stereocomplex PLA (poly lactic acid).

    PubMed

    Jeon, Byoung Wook; Lee, Jumin; Kim, Hyun Sook; Cho, Dae Haeng; Lee, Hyuk; Chang, Rakwoo; Kim, Yong Hwan

    2013-10-20

    R-lactide, a pivotal monomer for the production of poly (D-lactic acid) (PDLA) or stereocomplex poly (lactic acid) (PLA) was synthesized from alkyl (R)-lactate through a lipase-catalyzed reaction without racemization. From among several types of lipase, only lipase B from Candida antarctica (Novozym 435; CAL-B) was effective in the reaction that synthesized (R,R)-lactide. Enantiopure (R,R)-lactide, which consisted of over 99% enantiomeric excess, was synthesized from methyl (R)-lactate through CAL-B catalysis. Removal of the methanol by-product was critical to obtain a high level of lactide conversion. The (R,R)-lactide yield was 56% in a reaction containing 100 mg of Novozym 435, 10 mM methyl (R)-lactate and 1500 mg of molecular sieve 5A in methyl tert-butyl ether (MTBE). The important monomer (R,R)-lactide that is required for the production of the widely recognized bio-plastic PDLA and the PLA stereocomplex can be obtained using this novel synthetic method.

  5. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia

    2009-09-22

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  6. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2010-12-28

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  7. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography.

    PubMed

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren

    2015-04-29

    In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate-MAA ratios were investigated to prepare a series of 30% alkyl methacrylate-MAA-EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  8. An efficient preparation of isosteric phosphonate analogues of sphingolipids by opening of oxirane and cyclic sulfamidate intermediates with alpha-lithiated alkylphosphonic esters.

    PubMed

    Sun, Chaode; Bittman, Robert

    2004-10-29

    D-erythro-(2S,3R,4E)-Sphingosine-1-phosphonate (1), the isosteric phosphonate analogue of naturally occurring sphingosine 1-phosphate (1a), and D-ribo-phytosphingosine 1-phosphonate (2), the isosteric phosphonate analogue of D-ribo-phytosphingosine-1-phosphate (2a), were synthesized starting with methyl 2,3-O-isopropylidene-d-glycerate (4) and D-ribo-phytosphingosine (3), respectively. Oxirane 12 was formed in eight steps from 4, and cyclic sulfamidate 22 was formed in five steps from 3. The phosphonate group was introduced via regioselective ring-opening reactions of oxirane 12 and cyclic sulfamidate 22 with lithium dialkyl methylphosphonate, affording 13 and 23, respectively. The synthesis of 1 was completed by S(N)2 displacement of chloromesylate intermediate 14b with azide ion, followed by conversion of the resulting azido group to a NHBoc group and deprotection. The synthesis of 2 was completed by cleavage of the acetal, N-benzyl, and alkyl phosphonate ester groups.

  9. N-Acyl Amino Acid Ligands for Ruthenium(II)-Catalyzed meta-C-H tert-Alkylation with Removable Auxiliaries.

    PubMed

    Li, Jie; Warratz, Svenja; Zell, Daniel; De Sarkar, Suman; Ishikawa, Eloisa Eriko; Ackermann, Lutz

    2015-11-04

    Acylated amino acid ligands enabled ruthenium(II)-catalyzed C-H functionalizations with excellent levels of meta-selectivity. The outstanding catalytic activity of the ruthenium(II) complexes derived from monoprotected amino acids (MPAA) set the stage for the first ruthenium-catalyzed meta-functionalizations with removable directing groups. Thereby, meta-alkylated anilines could be accessed, which are difficult to prepare by other means of direct aniline functionalizations. The robust nature of the versatile ruthenium(II)-MPAA was reflected by challenging remote C-H transformations with tertiary alkyl halides on aniline derivatives as well as on pyridyl-, pyrimidyl-, and pyrazolyl-substituted arenes. Detailed mechanistic studies provided strong support for an initial reversible C-H ruthenation, followed by a SET-type C-Hal activation through homolytic bond cleavage. Kinetic analyses confirmed this hypothesis through an unusual second-order dependence of the reaction rate on the ruthenium catalyst concentration. Overall, this report highlights the exceptional catalytic activity of ruthenium complexes derived from acylated amino acids, which should prove instrumental for C-H activation chemistry beyond remote functionalization.

  10. Hydrogen bonds and van der Waals forces as tools for the construction of a herringbone pattern in the crystal structure of hexane-1,6-diaminium hexane-1,6-diyl bis-(hydrogen phospho-nate).

    PubMed

    Reiss, Guido J; van Megen, Martin; Frank, Walter

    2017-01-01

    The asymmetric unit of the title salt, [H3N(CH2)6NH3][(HO)O2P(CH2)6PO2(OH)], consists of one half of a hexane-1,6-diaminium dication and one half of a hexane-1,6-diyl bis-(hydrogen phospho-nate) dianion. Both are located around different centres of inversion (Wyckoff sites: 2a and 2d) of the space group P21/c. The shape of the hexane-1,6-diaminium cation is best described as a double hook. Both aminium groups as well as the two attached CH2 groups are turned out from the plane of the central four C atoms. In contrast, all six C atoms of the dianion are almost in a plane. The hydrogen phospho-nate (-PO3H) groups of the anions and the aminium groups of the cations form two-dimensional O-H⋯ and O-H⋯N hydrogen-bonded networks parallel to the ac plane, built up from ten-membered and twelve-membered ring motifs with graph-set descriptors R3(3)(10) and R5(4)(12), respectively. These networks are linked by the alkyl-ene chains of the anions and cations. The resulting three-dimensional network shows a herringbone pattern, which resembles the parent structures 1,6-di-amino-hexane and hexane-1,6-di-phospho-nic acid.

  11. Synthesis, characterization and fuel cell performance tests of boric acid and boron phosphate doped, sulphonated and phosphonated poly(vinyl alcohol) based composite membranes

    NASA Astrophysics Data System (ADS)

    Şahin, Alpay; Ar, İrfan

    2015-08-01

    The aim of this study is to synthesize a composite membrane having high proton conductivity, ion exchange capacity and chemical stability. In order to achieve this aim, poly(vinyl alcohol) (PVA) based composite membranes are synthesized by using classic sol-gel method. Boric acid (H3BO3) and boron phosphate (BPO4) are added to the membrane matrix in different ratios in order to enhance the membrane properties. Characterization tests, i.e; FT-IR analysis, mechanical strength tests, water hold-up capacities, swelling properties, ion exchange capacities, proton conductivities and fuel cell performance tests of synthesized membranes are carried out. As a result of performance experiments highest performance values are obtained for the membrane containing 15% boron phosphate at 0.6 V and 750 mA/cm2. Water hold-up capacity, swelling ratio, ion exchange capacity and proton conductivity of this membrane are found as 56%, 8%, 1.36 meq/g and 0.37 S/cm, respectively. These values are close to the values obtained ones for perfluorosulphonic acid membranes. Therefore this membrane can be regarded as a promising candidate for usage in fuel cells.

  12. Flame Resistant Cotton Durability and Antimicrobial Resistance Properties by using a Novel Epoxy Phosphonate Monomers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently we showed the design, synthesis, characterization, and usefulness of 2-(dimethoxy-phosphorylmethyl)-oxiranylmethyl]-phosphonic acid dimethyl ester that was generated from 3-chloro-2-chloromethylpropene (Polymer Preprints 2005, 46(1), 583-584). This monomer was grafted onto cotton fabrics (...

  13. The AlkB Family of Fe(II)/α-Ketoglutarate-dependent Dioxygenases: Repairing Nucleic Acid Alkylation Damage and Beyond.

    PubMed

    Fedeles, Bogdan I; Singh, Vipender; Delaney, James C; Li, Deyu; Essigmann, John M

    2015-08-21

    The AlkB family of Fe(II)- and α-ketoglutarate-dependent dioxygenases is a class of ubiquitous direct reversal DNA repair enzymes that remove alkyl adducts from nucleobases by oxidative dealkylation. The prototypical and homonymous family member is an Escherichia coli "adaptive response" protein that protects the bacterial genome against alkylation damage. AlkB has a wide variety of substrates, including monoalkyl and exocyclic bridged adducts. Nine mammalian AlkB homologs exist (ALKBH1-8, FTO), but only a subset functions as DNA/RNA repair enzymes. This minireview presents an overview of the AlkB proteins including recent data on homologs, structural features, substrate specificities, and experimental strategies for studying DNA repair by AlkB family proteins.

  14. The AlkB Family of Fe(II)/α-Ketoglutarate-dependent Dioxygenases: Repairing Nucleic Acid Alkylation Damage and Beyond*

    PubMed Central

    Fedeles, Bogdan I.; Singh, Vipender; Delaney, James C.; Li, Deyu; Essigmann, John M.

    2015-01-01

    The AlkB family of Fe(II)- and α-ketoglutarate-dependent dioxygenases is a class of ubiquitous direct reversal DNA repair enzymes that remove alkyl adducts from nucleobases by oxidative dealkylation. The prototypical and homonymous family member is an Escherichia coli “adaptive response” protein that protects the bacterial genome against alkylation damage. AlkB has a wide variety of substrates, including monoalkyl and exocyclic bridged adducts. Nine mammalian AlkB homologs exist (ALKBH1–8, FTO), but only a subset functions as DNA/RNA repair enzymes. This minireview presents an overview of the AlkB proteins including recent data on homologs, structural features, substrate specificities, and experimental strategies for studying DNA repair by AlkB family proteins. PMID:26152727

  15. Acid-catalyzed ortho-alkylation of anilines with styrenes: an improved route to chiral anilines with bulky substituents.

    PubMed

    Cherian, Anna E; Domski, Gregory J; Rose, Jeffrey M; Lobkovsky, Emil B; Coates, Geoffrey W

    2005-11-10

    [reaction: see text] Reaction of para-substituted anilines with styrene derivatives at elevated temperatures, when catalyzed by CF3SO3H, results in highly chemoselective ortho-alkylation of the aniline. When R = H, dialkylation can be achieved by varying the ratio of styrene to aniline. Several different substituted anilines and styrenes were examined, and good yields (42-87%) were obtained, except in the case where electron-withdrawing substituents are present on the styrene.

  16. A dual-task design of corrosion-controlling and osteo-compatible hexamethylenediaminetetrakis- (methylene phosphonic acid) (HDTMPA) coating on magnesium for biodegradable bone implants application.

    PubMed

    Zhao, Sheng; Chen, Yingqi; Liu, Bo; Chen, Meiyun; Mao, Jinlong; He, Hairuo; Zhao, Yuancong; Huang, Nan; Wan, Guojiang

    2015-05-01

    Magnesium as well as its alloys appears increasingly as a revolutionary bio-metal for biodegradable implants application but the biggest challenges exist in its too fast bio-corrosion/degradation. Both corrosion-controllable and bio-compatible Mg-based bio-metal is highly desirable in clinic. In present work, hexamethylenediaminetetrakis (methylenephosphonic acid) [HDTMPA, (H2 O3 P-CH2 )2 -N-(CH2 )6 -N-(CH2 -PO3 H2 )2 ], as a natural and bioactive organic substance, was covalently immobilized and chelating-deposited onto Mg surface by means of chemical conversion process and dip-coating method, to fullfill dual-task performance of corrosion-protective and osteo-compatible functionalities. The chemical grafting of HDTMPA molecules, by participation of functional groups on pretreated Mg surface, ensured a firmly anchored base layer, and then sub-sequential chelating reactions of HDTMPA molecules guaranteed a homogenous and dense HDTMPA coating deposition on Mg substrate. Electrochemical corrosion and immersion degradation results reveal that the HDTMPA coated Mg provides a significantly better controlled bio-corrosion/degradation behavior in phosphate buffer saline solution as compared with untreated Mg from perspective of clinic requirement. Moreover, the HDTMPA coated Mg exhibits osteo-compatible in that it induces not only bioactivity of bone-like apatite precipitation but also promotes osteoblast cells adhesion and proliferation. Our well-controlled biodegradable and biocompatible HDTMPA modified Mg might bode well for next generation bone implant application.

  17. Mesoporous cerium phosphonate nanostructured hybrid spheres as label-free Hg²⁺ fluorescent probes.

    PubMed

    Zhu, Yun-Pei; Ma, Tian-Yi; Ren, Tie-Zhen; Yuan, Zhong-Yong

    2014-09-24

    Porous phosphonate-based organic-inorganic hybrid materials have been shown to have novel and amazing physicochemical properties due to the integration of superiorities from both inorganic components and organic moieties. Herein, mesoporous cerium phosphonate nanostructured hybrid spheres are prepared with the assistance of cationic surfactant cetyltrimethylammonium bromide while using ethylene diamine tetra(methylene phosphonic acid) as the coupling molecule. The resulting hybrid is constructed from the cerium phosphonate nanoparticles, accompanied by high specific surface area of 455 m(2) g(-1). The uniform incorporation of rare-earth element cerium and organophosphonic functionalities endows mesoporous cerium phosphonate with excellent fluorescence properties for the development of an optical sensor for selective Hg(2+) detection on the basis of the fluorescence-quenching mechanism. The signal response of mesoporous cerium phosphonate against the Hg(2+) concentration is linear over the range from 0.05 to 1.5 μmol L(-1), giving a limit of detection of 16 nmol L(-1) (at a signal-to-noise ratio of 3). Most of the common physiologically relevant cations and anions did not interfere with the detection of Hg(2+). This label-free system provides a promising platform for further use in bioimaging and biomedical fields.

  18. Development of Oseltamivir Phosphonate Congeners as Anti-Influenza Agents

    PubMed Central

    Cheng, Ting-Jen R.; Weinheimer, Steven; Tarbet, E. Bart; Jan, Jia-Tsrong; Cheng, Yih-Shyun E.; Shie, Jiun-Jie; Chen, Chun-Lin; Chen, Chih-An; Hsieh, Wei-Che; Huang, Pei-Wei; Lin, Wen-Hao; Wang, Shi-Yun; Fang, Jim-Min; Hu, Oliver Yoa-Pu; Wong, Chi-Huey

    2012-01-01

    Oseltamivir phosphonic acid (tamiphosphor, 3a), its monoethyl ester (3c), guanidino-tamiphosphor (4a) and its monoethyl ester (4c) are potent inhibitors of influenza neuraminidases. They inhibit the replication of influenza viruses, including the oseltamivir-resistant H275Y strain, at low nM to pM levels, and significantly protect mice from infection with lethal doses of influenza viruses when orally administered with 1 mg/kg or higher doses. These compounds are stable in simulated gastric fluid, liver microsomes and human blood, and are largely free from binding to plasma proteins. Pharmacokinetic properties of these inhibitors are thoroughly studied in dogs, rats and mice. The absolute oral bioavailability of these compounds was lower than 12%. No conversion of monoester 4c to phosphonic acid 4a was observed in rats after intravenous administration, but partial conversion of 4c was observed with oral administration. Advanced formulation may be investigated to develop these new anti-influenza agents for better therapeutic use. PMID:23009169

  19. Chiral hydroxy phosphonates: synthesis, configuration and biological properties

    NASA Astrophysics Data System (ADS)

    Kolodiazhnyi, Oleg I.

    2006-03-01

    Published data on the synthesis, absolute configurations and biological properties of chiral hydroxy phosphonates are generalised and described systematically. Examples of asymmetric synthesis of hydroxy phosphonates by the phospho-aldol reaction, reduction of keto phosphonates, chemo-enzymatic approach, and so on are discussed. Methods for determination of the optical purity and absolute configuration of hydroxy phosphonates using modification by chiral reagents, NMR, circular dichroism, GLC and HPLC on columns with chiral sorbents are considered. The significance of hydroxy phosphonates as promising compounds for the development of new drugs and bioregulators is demonstrated.

  20. Use of short chain alkyl imidazolium ionic liquids for on-line stacking and sweeping of methotrexate, flinic acid and folic acid: their application to biological fluids.

    PubMed

    Abd El-Hady, Deia; Albishri, Hassan M; Rengarajan, Rajesh; Wätzig, Hermann

    2014-07-01

    Methotrexate (MTX) is widely used for the treatment of many types of cancer. Folinic acid (FNA) and folic acid (FA) were usually simultaneously supplemented with MTX to reduce the side effects of a folate deficiency. This study, for the first time, included on-line sample preconcentration by stacking and sweeping techniques under reduced or enhanced electric conductivity in the sample region using short chain alkyl imidazolium ionic liquids (ILs) as micelle forming agents for analyte focusing. Both analyte focusing by micelle collapse (AFMC) and sweeping-MEKC had been investigated for the comparison of their effectiveness to examine simultaneously MTX, FNA and FA in plasma and urine under physiological conditions. In sweeping-MEKC, the sample solution without micelles was hydrodynamically injected as a long plug into a fused-silica capillary pre-filled with phosphate buffer containing 3.0 mol/L of 1-butyl-3-methylimidazolium bromide (BMIMBr). Using AFMC, the analytes were prepared in BMIMBr micellar matrix and hydrodynamically injected into the phosphate buffer without IL micelles. The conductivity ratio between BGE and sample (γ, BGE/sample) was optimized to be 3.0 in sweeping-MEKC and 0.33 in AFMC resulting the adequate separation of analytes within 4.0 min. To reduce the possibility of BMIMBr adsorption, an appropriate rinsing protocol was used. The limits of detection were calculated as 0.1 ng/mL MTX, 0.05 ng/mL FNA and 0.05 ng/mL FA by sweeping-MEKC and 0.5 ng/mL MTX, 0.3 ng/mL FNA and 0.3 ng/mL FA by AFMC. The accuracy was tested by recovery in plasma and urine matrices giving values ranging between 90 and 110%. Both stacking and sweeping by BMIMBr could be successfully used for the rapid, selective and sensitive determination of pharmaceuticals in complex matrices due to its fascinating properties, including high conductivity, good thermal stability and ability to form different types of interactions by electrostatic, hydrophobic, hydrogen bonding and

  1. Metal phosphonate hybrid mesostructures: environmentally friendly multifunctional materials for clean energy and other applications.

    PubMed

    Ma, Tian-Yi; Yuan, Zhong-Yong

    2011-10-17

    The synthesis of porous hybrid materials has been extended to mesoporous non-silica-based organic-inorganic hybrid materials, in which mesoporous metal phosphonates represent an important family. By using organically bridged polyphosphonic acids as coupling molecules, the homogeneous incorporation of a considerable number of organic functional groups into the metal phosphonate hybrid framework has been realized. Small amounts of organic additives and the pH value of the reaction solution have a large impact on the morphology and textural properties of the resultant hybrid mesoporous metal phosphonate solids. Cationic and nonionic surfactants can be used as templates for the synthesis of ordered mesoporous metal phosphonates. The materials are used as efficient adsorbents for heavy metal ions, CO₂, and aldehydes, as well as in the separation of polycyclic aromatic hydrocarbons. They are also useful photocatalysts under UV and simulated solar light irradiation for organic dye degradation. Further functionalization of the synthesized mesoporous hybrids makes them oxidation and acid catalysts, both with impressive performances in the fields of sustainable energy and environment.

  2. Mechanistic understanding of calcium-phosphonate solid dissolution and scale inhibitor return behavior in oilfield reservoir: formation of middle phase.

    PubMed

    Zhang, Ping; Shen, Dong; Ruan, Gedeng; Kan, Amy T; Tomson, Mason B

    2016-08-03

    Phosphonates are an important class of mineral scale inhibitors used for oilfield scale control. By injecting the phosphonate into an oilfield reservoir, calcium-phosphonate precipitate will form and subsequently release the phosphonate into produced water for scale control. In this study, a systematic procedure is developed to mechanistically characterize an acidic calcium-phosphonate amorphous material that is later developed into a middle phase and eventually a crystalline phase. The phosphonate used in this study is diethylenetriamine pentakis (methylene phosphonic acid) (DTPMP). An amorphous calcium-DTPMP solid is precipitated by mixing a calcium-containing solution with a DTPMP solution. The stoichiometry of this initially formed solid can be experimentally confirmed via a static dissolution test. Following another dynamic development test, two additional Ca-DTPMP solid phases, i.e., a middle phase and a crystalline phase have been observed. Electron microscopy and X-ray diffraction were employed to characterize the morphology and crystallinity of different Ca-DTPMP solids of interest. Evidently, the dynamic brine flushing of the Ca-DTPMP solid developed the initially amorphous material into a middle phase solid with an amorphous/microcrystalline structure and eventually into a crystalline material. Furthermore, a dissolution characterization study was carried out to determine the solubility product of the middle phase solid at different conditions. The obtained mechanistic understanding of the Ca-DTPMP solid related to precipitation chemistry, dissolution behavior and phase transition is critical to elucidate oilfield DTPMP return data and more importantly, can optimize the oilfield scale squeeze design to achieve an extended squeeze lifetime.

  3. A new approach to cyclic hydroxamic acids: Intramolecular cyclization of N-benzyloxy carbamates with carbon nucleophiles

    PubMed Central

    Liu, Yuan; Jacobs, Hollie K.

    2011-01-01

    N-Alkyl-N-benzyloxy carbamates, 2, undergo facile intramolecular cyclization with a variety of carbon nucleophiles to give functionalized 5- and 6-membered protected cyclic hydroxamic acids, 3, in good to excellent yields. This method can be extended to prepare seven-membered cyclic hydroxamic acids in moderate yields. The sulfone intermediates 3 from this study can be alkylated while the corresponding phosphonates have been shown to undergo HWE reaction. The α,β-unsaturated synthon, 8, prepared by thermal elimination of sulfoxide 3m, undergoes Michael addition with secondary amines. The usefulness of this approach to prepare polydentate chelators has been demonstrated by the synthesis of bis cyclic hydroxamic acids 12, 14, and 15. PMID:21499514

  4. Gas chromatography with tandem differential mobility spectrometry of fatty acid alkyl esters and the selective detection of methyl linolenate in biodiesels by dual-stage ion filtering.

    PubMed

    Pasupuleti, D; Pierce, K; Eiceman, G A

    2015-11-20

    Alkyl esters of fatty acids (FAAEs) with carbon numbers from 8 to 20 formed protonated monomers and proton bound dimers through atmospheric pressure chemical ionization reactions and these gas ions were characterized for their field dependent mobility coefficients using differential mobility spectrometry (DMS). Separation of ion peaks with a vapor modifier was achieved for ions with masses of 317-1033 Da though the differences in these coefficients and the resolution of ion peaks decreased proportionally with increased ion mass. Differences in dispersion curves were sufficient to isolate ions from specific FAAEs in the effluent of a gas chromatograph by dual stage ion filtering using a tandem DMS detector. Methyl linolenate was isolated from nearby eluting methyl oleate, methyl stearate and methyl linoleate within analysis times of 10s without measureable complications from charge suppression in the ion source or leakage in filtering of ions with close proximity of dispersion behavior.

  5. Efficient conversion of furfuryl alcohol into alkyl levulinates catalyzed by an organic-inorganic hybrid solid acid catalyst.

    PubMed

    Zhang, Zehui; Dong, Kun; Zhao, Zongbao Kent

    2011-01-17

    A clean, facile, and environment-friendly catalytic method has been developed for the conversion of furfuryl alcohol into alkyl levulinates making use of the novel solid catalyst methylimidazolebutylsulfate phosphotungstate ([MIMBS]₃PW₁₂O₄₀). The solid catalyst is an organic-inorganic hybrid material, which consists of an organic cation and an inorganic anion. A study for optimizing the reaction conditions such as the reaction time, the temperature and the catalyst loading has been performed. Under optimal conditions, a high n-butyl levulinate yield of up to 93 % is obtained. Furthermore, the kinetics of the reaction pathways and the mechanism for the alcoholysis of furfuryl alcohol are discussed. This method is environmentally benign and economical for the conversion of biomass-based derivatives into fine chemicals.

  6. Hydrothermal synthesis and structural characterization of ammonium ion-templated lanthanide(III) carboxylate-phosphonates

    PubMed Central

    Ayi, Ayi A.; Kinnibrugh, Tiffany L.; Clearfield, Abraham

    2014-01-01

    Using N-(phosphonomethyl) iminodiacetic acid (H4PMIDA), as a complexing agent, two new complexes, (NH4)La(PMIDA)(H2O)•H2O, 1 and (NH4)Yb(PMIDA), 2 have been synthesized hydrothermally. In both compounds, the metal ions are trapped by a three five-membered chelate rings by the chelating PMIDA anions giving a tricapped trigonal prismatic LaO8N and monocapped trigonal prismatic YbO6N geometries for 1 and 2, respectively. The structure of 1 consists of La(PMIDA)(H2O) chelating units, linked together by the phosphonate oxygen atoms O1 and O3 to form a chain along the c-axis. The chains are then connected together by the bridging phosphonate oxygen O2 to form a 2D layered structure with alternating 4- and 8-membered apertures. The structure of 2 consists Yb(PMIDA) chelating units, which are connected by alternating bridging carboxylate and phosphonate groups along the [010] direction forming chains with a corrugated pattern. The third phosphonate oxygen bridges the chains together along the [001] direction to build the two-dimensional layer with 4- and 6-membered apertures in the bc-plane. Under excitation of 330 nm, compound 2 shows a broad emission band at λmax = 460 nm. This emission is essentially in the blue luminescent region, which corresponds to ligand centered fluorescence. PMID:25414845

  7. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  8. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  9. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  10. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  11. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  12. 40 CFR 721.10067 - Ether amine phosphonate salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ether amine phosphonate salt (generic... Specific Chemical Substances § 721.10067 Ether amine phosphonate salt (generic). (a) Chemical substances... ether amine phosphonate salt (PMNs P-05-57, P-05-58, P-05-59, P-05-61, P-05-62, P-05-63, P-05-64, and...

  13. Influences of humic acid on the bioavailability of phenanthrene and alkyl phenanthrenes to early life stages of marine medaka (Oryzias melastigma).

    PubMed

    Liu, Yangzhi; Yang, Chenghu; Cheng, Pakkin; He, Xiaojing; Zhu, Yaxian; Zhang, Yong

    2016-03-01

    The influences of humic acid (HA) on the environmental behavior and bioavailability of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs were investigated and compared using the early life stages of marine medaka (Oryzias melastigma, O. melastigma). It was demonstrated that the binding affinity of parent phenanthrene (PHE) with HA was smaller than that of 3-methyl phenanthrene (3-MP) and 9-ethyl phenanthrene (9-EP). Furthermore, the bioaccumulation of the three PAHs and the levels of lipid peroxidation (LPO) were calculated to study the changes in bioavailability of PAHs in presence of HA. The results indicated that the addition of HA significantly decreased the bioaccumulation and toxicity of PAHs by decreasing free PAHs concentrations. The bioavailable fractions of HA-bound PAHs in bioaccumulation (α) and toxicity (β) were evaluated, indicating that the HA-bound 3-MP and 9-EP show higher bioavailability in bioaccumulation and lower bioavailability in toxicity relative to those of PHE. The β/α values were less than 1 for all PAH treatment groups containing HA, suggesting that the fraction of HA-bound PAHs contributing to bioaccumulation was higher than that of HA-bound PAHs inducing toxic effect. In addition, we proposed that the free PAHs generated by desorption from HA in the cell were toxic by showing that the β/α ratio values are correlated with the log KOW values (p = 0.007 and R(2) = 0.8355). Thus, oil spill risk assessments should consider both alkyl PAHs and the factors that influence the bioavailability and toxicity of PAHs in the natural aquatic environments.

  14. Catalytic asymmetric synthesis of {alpha}-amino phosphonates using lanthanoid-potassium-BINOL complexes

    SciTech Connect

    Sasai, Hiroaki; Arai, Shigeru; Shibasaki, Masakatsu

    1995-10-20

    {alpha}-Amino phosphonic acids 3 are interesting compounds in the design of enzyme inhibitors. The concept of mimicking tetrahedral transition states of enzyme-medicated peptide bond hydrolysis previously led to the successful design and synthesis of phosphonamide-containing peptides as a promising new class of proteinase inhibitors. It is not surprising that the absolute configuration of the {alpha}-carbon strongly influences the biological properties of 3. Several methods for the synthesis of optically active {alpha}-aminophosphonic acids have been published. The authors report here the first example of a catalytic asymmetric hydrophosphonylation to imines using lanthanoid-potassium-BINOL heterobimetallic complexes (LnPB, Ln = lanthanoid metal), which gives optically active {alpha}-amino phosphonates in modest to high enantiometric excess. 17 refs., 1 tab.

  15. Preparation and use of crystalline bis-monoorganic phosphonate and phosphate salts of tetravalent metals

    DOEpatents

    Maya, L.

    1980-06-26

    A method of preparing and using the crystalline organic derivatives of the tetravalent metal phosphates and phosphonates provides for the contacting of an aqueous solution of a metal nitrate, with a solution of an organophosphorus acid for a period of time at room temperature that is sufficient for the formation of a metal phosphate product, and thereafter recovering said product. According to the invention, the product of the disclosed process is used in effecting analytical separations, such as ion exchange and chromatography.

  16. Distorted cubic tetranuclear vanadium(IV) phosphonate cages: double-four-ring (D4R) containing transition metal ion phosphonate cages.

    PubMed

    Chandrasekhar, Vadapalli; Dey, Atanu; Senapati, Tapas; Sañudo, E Carolina

    2012-01-21

    The reaction of VCl(3) with 3,5-dimethylpyrazole (3,5-Me(2)PzH) and trichloromethylphosphonic/tert-butylphosphonic acid in the presence of triethylamine as a hydrogen chloride scavenger afforded the tetranuclear V(IV) assemblies, [(VO)(4)(3,5-Me(2)PzH)(8)(CCl(3)PO(3))(4)] (1) and [(VO)(4)(3,5-Me(2)PzH)(4)(t-BuPO(3))(4)] (2). Both of these compounds possess a distorted cubic framework structures containing V(IV) ions and phosphorus atoms in the alternate corners of the cube. The edges of the cube contain oxygen atoms derived from the phosphonate ligand. The phosphonate ligand in both of these compounds is dianionic and helps to bind to three V(IV) centers. The faces of the cubic ensembles contain puckered V(2)P(2)O(4) eight-membered rings. The V(IV) center in 1 is six-coordinate in a distorted octahedral geometry while in 2 it is five-coordinate in a distorted square-pyramidal geometry. Magnetic studies carried out on 1 and 2 reveal that the V(IV) centers are anti-ferromagnetically coupled to each other, albeit weakly, through the mediation of the phosphonate ligands.

  17. Aerobic biotransformation of alkyl branched aromatic alkanoic naphthenic acids via two different pathways by a new isolate of Mycobacterium.

    PubMed

    Johnson, Richard J; West, Charles E; Swaih, Aisha M; Folwell, Ben D; Smith, Ben E; Rowland, Steven J; Whitby, Corinne

    2012-04-01

    Naphthenic acids (NAs) are complex mixtures of carboxylic acids found in weathered crude oils and oil sands, and are toxic, corrosive and persistent. However, little is known about the microorganisms and mechanisms involved in NA degradation. We isolated a sediment bacterium (designated strain IS2.3), with 100% 16S rRNA gene sequence identity to Mycobacterium aurum, which degraded synthetic NAs (4'-n-butylphenyl)-4-butanoic acid (n-BPBA) and (4'-t-butylphenyl)-4-butanoic acid (t-BPBA). n-BPBA was readily oxidized with almost complete degradation (96.8% ± 0.3) compared with t-BPBA (77.8% ± 3.7 degraded) by day 49. Cell counts increased fourfold by day 14 but decreased after day 14 for both n- and t-BPBA. At day 14, (4'-butylphenyl)ethanoic acid (BPEA) metabolites were detected. Additional metabolites produced during t-BPBA degradation were identified by mass spectrometry of derivatives as (4'-carboxy-t-butylphenyl)-4-butanoic acid and (4'-carboxy-t-butylphenyl)ethanoic acid; suggesting that strain IS2.3 used omega oxidation of t-BPEA to oxidize the tert-butyl side-chain to produce (4'-carboxy-t-butylphenyl)ethanoic acid, as the primary route for biodegradation. However, strain IS2.3 also produced this metabolite through initial omega oxidation of the tert-butyl side-chain of t-BPBA, followed by beta-oxidation of the alkanoic acid side-chain. In conclusion, an isolate belonging to the genus Mycobacterium degraded highly branched aromatic NAs via two different pathways.

  18. An ultra-sensitive method for the analysis of perfluorinated alkyl acids in drinking water using a column switching high-performance liquid chromatography tandem mass spectrometry.

    PubMed

    Dasu, Kavitha; Nakayama, Shoji F; Yoshikane, Mitsuha; Mills, Marc A; Wright, J Michael; Ehrlich, Shelley

    2017-04-21

    In epidemiological research, it has become increasingly important to assess subjects' exposure to different classes of chemicals in multiple environmental media. It is a common practice to aliquot limited volumes of samples into smaller quantities for specific trace level chemical analyses. A novel method was developed for the determination of 14 perfluorinated alkyl acids (PFAAs) in small volumes (10mL) of drinking water using off-line solid phase extraction (SPE) pre-treatment followed by on-line pre-concentration on a WAX column before analysis on column-switching high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In general, large volumes (100-1000mL) have been used for the analysis of PFAAs in drinking water. The current method requires approximately 10mL of drinking water concentrated by using an SPE cartridge and eluted with methanol. A large volume injection of the extract was introduced on to a column-switching HPLC-MS/MS using a mix-mode SPE column for the trace level analysis of PFAAs in water. The recoveries for most of the analytes in the fortified laboratory blanks ranged from 73±14% to 128±5%. The lowest concentration minimum reporting levels (LCMRL) for the 14 PFAAs ranged from 0.59 to 3.4ng/L. The optimized method was applied to a pilot-scale analysis of a subset of drinking water samples from an epidemiological study. These samples were collected directly from the taps in the households of Ohio and Northern Kentucky, United States and the sources of drinking water samples are both surface water and ground water, and supplied by different water distribution facilities. Only five PFAAs, perfluoro-1-butanesulfonic acid (PFBS), perfluoro-1- -hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluoro-n-heptanoic acid (PFHpA) and perfluoro-n-octanoic acid (PFOA) are detected above the LCMRL values. The median concentrations of these five PFAAs detected in the samples was ≤4.1ng/L with PFOS at 7.6ng

  19. Regioselectivity of Birch reductive alkylation of biaryls.

    PubMed

    Lebeuf, Raphaël; Robert, Frédéric; Landais, Yannick

    2005-10-13

    [reaction: see text] The regioselectivity of the Birch reductive alkylation of polysubstituted biaryls has been investigated. Results indicate that regioselectivity is affected by the electronic nature of substituents on both aromatic rings. The electron-rich 3,5-dimethoxyphenyl moiety is selectively reduced and then alkylated, while phenols and aniline are not dearomatized under these conditions. Biaryls possessing a phenol moiety are alkylated on the second ring, providing that the acidic proton has been removed prior to the Li/NH3 reduction.

  20. Nitro-fatty acid reaction with glutathione and cysteine. Kinetic analysis of thiol alkylation by a Michael addition reaction.

    PubMed

    Baker, Laura M S; Baker, Paul R S; Golin-Bisello, Franca; Schopfer, Francisco J; Fink, Mitchell; Woodcock, Steven R; Branchaud, Bruce P; Radi, Rafael; Freeman, Bruce A

    2007-10-19

    Fatty acid nitration by nitric oxide-derived species yields electrophilic products that adduct protein thiols, inducing changes in protein function and distribution. Nitro-fatty acid adducts of protein and reduced glutathione (GSH) are detected in healthy human blood. Kinetic and mass spectrometric analyses reveal that nitroalkene derivatives of oleic acid (OA-NO2) and linoleic acid (LNO2) rapidly react with GSH and Cys via Michael addition reaction. Rates of OA-NO2 and LNO2 reaction with GSH, determined via stopped flow spectrophotometry, displayed second-order rate constants of 183 M(-1)S(-1) and 355 M(-1)S(-1), respectively, at pH 7.4 and 37 degrees C. These reaction rates are significantly greater than those for GSH reaction with hydrogen peroxide and non-nitrated electrophilic fatty acids including 8-iso-prostaglandin A2 and 15-deoxy-Delta(12,14)-prostaglandin J2. Increasing reaction pH from 7.4 to 8.9 enhanced apparent second-order rate constants for the thiol reaction with OA-NO2 and LNO2, showing dependence on the thiolate anion of GSH for reactivity. Rates of nitroalkene reaction with thiols decreased as the pKa of target thiols increased. Increasing concentrations of the detergent octyl-beta-d-glucopyranoside decreased rates of nitroalkene reaction with GSH, indicating that the organization of nitro-fatty acids into micellar or membrane structures can limit Michael reactivity with more polar nucleophilic targets. In aggregate, these results reveal that the reversible adduction of thiols by nitro-fatty acids is a mechanism for reversible post-translational regulation of protein function by nitro-fatty acids.

  1. Adsorbed States of phosphonate derivatives of N-heterocyclic aromatic compounds, imidazole, thiazole, and pyridine on colloidal silver: comparison with a silver electrode.

    PubMed

    Podstawka, Edyta; Olszewski, Tomasz K; Boduszek, Bogdan; Proniewicz, Leonard M

    2009-09-03

    Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

  2. Cytotoxicity of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-ethyl derivative of thiosalicylic acid

    NASA Astrophysics Data System (ADS)

    Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Milovanović, Jelena; Arsenijević, Aleksandar; Stojanović, Bojana; Trifunović, Srećko R.; Radić, Gordana P.

    2016-07-01

    The spectroscopically predicted structure of the obtained copper(II)-complex with S-ethyl derivative of thiosalicylic acid was confirmed by X-ray structural study and compared to previously reported crystal structure of the Cu complex with S-methyl derivative. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Cytotoxic effects of S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding binuclear copper(II)-complexes on murine colon carcinoma cell lines, CT26 and CT26.CL25 and human colon carcinoma cell line HCT-116 were reported here. The analysis of cancer cell viability showed that all the tested complexes had low cytotoxic effect on murine colon carcinoma cell lines, but several times higher cytotoxicity on normal human colon carcinoma cells.

  3. Diversity and abundance of phosphonate biosynthetic genes in nature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphonates, molecules containing direct C-P bonds, comprise a structurally diverse class of natural products with interesting and useful biological properties. Although their synthesis in protozoa was discovered more than fifty years ago, the extent and diversity of phosphonate production in natur...

  4. Determination of relative acidities of some alpha, omega-bis(3-alkyl(aryl)-4,5-dihydro-1H-1,2,4-triazol-5-on-4-yl) alkanes.

    PubMed

    Karaböcek, S; Dalman, O; Nohut, S; Tüfekçi, M; Sancak, K; Güner, S

    1998-07-01

    The solutions of nine alpha, omega-bis(3-alkyl(aryl)-4,5-dihydro-1H-1,2,4-triazol-5-on-4-yl) alkanes were titrated with tetrabutylammoniumhydroxide (TBAH) in methanol, using potentiometric methods. The half neutralization potentials values were found for all cases. Potentiometric titration curves of compounds in methanol with 0.03 M TBAH are similar to those of weak acids obtained in aqueous media with strong bases. Methanol is found to be a suitable medium for the weakly acidic compounds titrated since they are poorly dissolved in other organic solvents. A comparison among the compounds having the same alkyl chains between the two ring systems has shown that basicity increases and acidity decreases as the size of alkyl chains increases. However, the compound with a substituted phenyl group was found to be the most acidic one among the examined compounds indicating that phenyl group donates ring electrons less effectively to the system. This can be attributed to the stability of the benzene ring.

  5. Nanostructured alkyl carboxylic acid-based restricted access solvents: Application to the combined microextraction and cleanup of polycyclic aromatic hydrocarbons in mosses.

    PubMed

    Caballero-Casero, N; Çabuk, H; Martínez-Sagarra, G; Devesa, J A; Rubio, S

    2015-08-26

    Alkyl carboxylic acid-based nanostructured solvents, synthesized in mixtures of tetrahydrofuran (THF) and water through self-assembly and coacervation, were proved to behave as restricted access liquids. Both physical and chemical mechanisms were found responsible for exclusion of macromolecules such as proteins and polysaccharides. The potential of these solvents for extracting small molecules from complex solid samples, without interference from large biomolecules, was here evaluated. For this purpose, they were applied to the extraction of 14 priority polycyclic aromatic hydrocarbons (PAHs) from mosses prior to their separation by liquid chromatography and fluorescence detection (LC-FLD). Sample treatment involved the vortex shaking of 200 mg of moss with 200 μL of decanoic acid-based solvent for 5 min, subsequent centrifugation for 8 min and analysis of the extract by LC-FLD using external calibration. Proteins precipitated during extraction because of both the decrease of the dielectric constant of the solution caused by THF and the formation of macromolecular complexes with decanoic acid. Polysaccharides were not solubilized in the aqueous cavities of the solvent because of their size exclusion. In-house method validation was performed according to the recommendations of the European Commission Decision 202/657/EC. Method detection and quantification limits for the different PAHs were in the ranges 0.04-0.24 and 0.14-0.80 μg kg(-1), respectively. The method was applied to the determination of different moss species collected in both polluted and unpolluted sites in the South of Spain. Recoveries were within the range 71-110%. The results obtained show that solvents with restricted access properties have the potential to expand the scope of application of restricted access materials to areas other than biological fluids because of their suitability to combine analyte isolation and sample cleanup of solid samples in a single step.

  6. Alkyl sulfonic acide hydrazides: Synthesis, characterization, computational studies and anticancer, antibacterial, anticarbonic anhydrase II (hCA II) activities

    NASA Astrophysics Data System (ADS)

    O. Ozdemir, Ummuhan; İlbiz, Firdevs; Balaban Gunduzalp, Ayla; Ozbek, Neslihan; Karagoz Genç, Zuhal; Hamurcu, Fatma; Tekin, Suat

    2015-11-01

    Methane sulfonic acide hydrazide, CH3SO2NHNH2 (1), ethane sulfonic acide hydrazide, CH3CH2SO2NHNH2 (2), propane sulfonic acide hydrazide, CH3CH2CH2SO2NHNH2 (3) and butane sulfonic acide hydrazide, CH3CH2CH2CH2SO2NHNH2 (4) have been synthesized as homologous series and characterized by using elemental analysis, spectrophotometric methods (1H-13C NMR, FT-IR, LC-MS). In order to gain insight into the structure of the compounds, we have performed computational studies by using 6-311G(d, p) functional in which B3LYP functional were implemented. The geometry of the sulfonic acide hydrazides were optimized at the DFT method with Gaussian 09 program package. A conformational analysis of compounds were performed by using NMR theoretical calculations with DFT/B3LYP/6-311++G(2d, 2p) level of theory by applying the (GIAO) approach. The anticancer activities of these compounds on MCF-7 human breast cancer cell line investigated by comparing IC50 values. The antibacterial activities of synthesized compounds were studied against Gram positive bacteria; Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Bacillus cereus NRRL-B-3711, Enterococcus faecalis ATCC 29212 and Gram negative bacteria; Escherichia coli ATCC 11230, Pseudomonas aeruginosa ATCC 15442, Klebsiella pneumonia ATCC 70063 by using the disc diffusion method. The inhibition activities of these compounds on carbonic anhydrase II enzyme (hCA II) have been investigated by comparing IC50 and Ki values. The biological activity screening shows that butane sulfonic acide hydrazide (4) has more activity than the others against tested breast cancer cell lines MCF-7, Gram negative/Gram positive bacteria and carbonic anhydrase II (hCA II) isoenzyme.

  7. Biosynthesis of murein lipoprotein in Escherichia coli: effects of 3,4-dihydroxybutyl-1-phosphonate.

    PubMed Central

    Chattopadhyay, P K; Engel, R; Tropp, B E; Wu, H C

    1979-01-01

    The effects of 3,4-dihydroxybutyl-1-phosphonate, a four-carbon analog of sn-glycerol 3-phosphate, on the biosynthesis of the glyceryl moiety in murein lipoprotein of Escherichia coli were studied. The compound at a concentration of 55 microM strong inhibits in the incorporation of [2-3H]glycerol radioactivity into lipoprotein by virtue of its inhibition of the synthesis of phosphatidylglycerol. On the other hand, the incorporation of prelabeled [2-3H]glycerol radioactivity into lipoprotein was only partially inhbited by 3,4-dihydroxybutyl-1-phosphonate even at a much higher concentration (1 mM). These data were consistent with the postulated pathway for the biosynthesis of the lipid moiety in lipoportein: cysteine-lipoprotein + phosphatidylglycerol leads to glycerylcystein-lipoprotein + phosphatidic acid. PMID:378946

  8. Physico-chemical studies and emulsifying properties of N-propyl-N-methylene phosphonic chitosan.

    PubMed

    Albertengo, Liliana; Farenzena, Sonia; Debbaudt, Adriana; Zuñiga, Adriana; Schulz, Pablo; Rodriguez, Maria Susana

    2013-02-15

    Chitosan is a modified, natural carbohydrate polymer derived by deacetylation of chitin. Due to the presence of two functional groups can undergo many chemical modifications. In a previous work we described the synthetic strategy and characterization of a novel soluble derivative: N-propyl-N-methylene phosphonic chitosan (PNMPC). In the study of some physicochemical properties, results showed that this modified chitosan aggregates in several steps when the concentration is increased. By addition of NaOH the initially coiled molecules stretch exposing more phosphonic acid groups to neutralization and finally give a cooperative reaction with OH((). PNMPC has emulsifying properties and gives O/W emulsions with quasi-monodisperse small droplets. Emulsions with 0.18% PNMPC and 30:70 o:w ratio exhibited the best emulsifying properties within the test range. This emulsion ratio showed high stability to long time storage and several successive freeze/thaw and heating/cooling cycles.

  9. Estimation of alkane-water logP for neutral, acidic, and basic compounds using an alkylated polystyrene-divinylbenzene high-performance liquid chromatography column.

    PubMed

    Jensen, Derek A; Gary, Ronald K

    2015-10-23

    Reliable HPLC methods are available to estimate octanol-water partition coefficients, but there is no comparable method for alkane-water partition coefficients that is accurate and applicable across a broad span of logP(alk). This study describes a high-throughput method for determining HPLC-logP(alk), a chromatographic parameter closely related to logP(alk), using an alkylated polystyrene-divinylbenzene column and fast acetonitrile gradient. A structurally diverse set of neutral, acidic, and basic compounds was analyzed under ionization-suppressing pH conditions. In this chromatographic system, the relationship between gradient retention time and isocratic logk was essentially linear. Thus, gradient retention time could be used as the sole input needed to determine an apparent logP(alk)by HPLC. HPLC-logP(alk) showed linear correlation (R(2)>0.96, n=59) with reference logP(alk) values from shake-flask measurements over 8 orders of magnitude, ranging from -2.3 to +5.7. Linear solvation energy relationship (LSER) analysis revealed that the relative contributions of intermolecular forces effecting retention in the fast gradient system or its corresponding isocratic variant were highly similar to those governing partition in bulk alkane-water.

  10. Synthesis, biological evaluation, and structure-activity relationships for 5-[(E)-2-arylethenyl]-3-isoxazolecarboxylic acid alkyl ester derivatives as valuable antitubercular chemotypes.

    PubMed

    Pieroni, Marco; Lilienkampf, Annamaria; Wan, Baojie; Wang, Yuehong; Franzblau, Scott G; Kozikowski, Alan P

    2009-10-22

    Tuberculosis (TB), mostly caused by Mycobacterium tuberculosis (Mtb), is one of the leading causes of death from infectious disease worldwide. Its coinfection with HIV and the emergence of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) strains have further worsened the TB pandemic. Despite its global impact, TB is considered a neglected disease and no new anti-TB therapeutics have been introduced over the last four decades. The nonreplicating persistent form of TB (NRP-TB) is responsible for the length of the treatment and is the putative cause of treatment failure. Therefore, new anti-TB agents, which are active against both the replicating form of Mtb (R-TB) and NRP-TB, are urgently needed. Herein, we report the synthesis and structure-activity relationships (SAR) of a series of 5-[(E)-2-arylethenyl]-3-isoxazolecarboxylic acid alkyl esters as potent anti-TB agents. Several compounds had submicromolar minimum inhibitory concentrations (MIC) against R-TB and were active against NRP-TB in the low micromolar range, thus representing attractive lead compounds for the possible development of new anti-TB agents.

  11. Use of dynamic simulation to assess the behaviour of linear alkyl benzene sulfonates and their biodegradation intermediates (sulfophenylcarboxylic acids) in estuaries

    NASA Astrophysics Data System (ADS)

    García-Luque, E.; González-Mazo, E.; Forja, J. M.; Gómez-Parra, A.

    2009-02-01

    Dynamic laboratory simulation of processes affecting chemical species in their transit through estuaries is a very useful tool to characterize these littoral systems. To date, laboratory studies concerning biodegradation and sorption (onto suspended particulate matter) of LAS in an estuary are scarce. For this reason, a dynamic automated estuarine simulator has been employed to carry out different experiments in order to assess the biodegradability of linear alkyl benzene sulfonates (LAS) and their biodegradation intermediates (sulfophenylcarboxylic acids, SPCs) using environmentally representative LAS concentrations in estuaries by a continuous injection of LAS into the system. During the experiments, a great affinity of LAS for the solid phase has been found, as well as an increased adsorption in line with increased chain length. On the other hand, the presence of SPCs with chain length between 6 and 13 carbon atoms was detected. Accumulation and persistence of medium chain length SPCs (C 6-C 8) along the experiments show that their degradation constitutes the limiting step for the process of LAS mineralization. In the final zone of the simulated estuarine system, the levels of SPCs were below the limits of detection. Thus, the disappearance of SPCs indicated that LAS biodegradation had been completed along the estuary. Similar results have been described for different Iberian littoral ecosystems. Therefore, the simulator employed in this research appears to be a useful tool to anticipate the behaviour of a xenobiotic chemical in its transit through littoral systems with different salinity gradients.

  12. Cyclic phosphatidic acid inhibits alkyl-glycerophosphate-induced downregulation of histone deacetylase 2 expression and suppresses the inflammatory response in human coronary artery endothelial cells.

    PubMed

    Tsukahara, Tamotsu; Haniu, Hisao; Matsuda, Yoshikazu

    2014-01-01

    Activation of the endothelium by alkyl-glycerophosphate (AGP) has been implicated in the development of atherosclerosis. Our previous study suggested that cyclic phosphatidic acid (cPA) inhibits arterial wall remodeling in a rat model in vivo. However, the mechanisms through which specific target genes are regulated during this process remain unclear. Here, we examined whether cPA inhibited AGP-induced expression of class I histone deacetylases (HDACs, namely HDAC1, HDAC2, HDAC3, and HDAC8), which may affect subsequent transcriptional activity of target genes. Our experimental results showed that human coronary artery endothelial cells (HCAECs) expressed high levels of HDAC2 and low levels HDAC1, HDAC3, and HDAC8. Moreover, AGP treatment induced downregulation of HDAC2 expression in HCAECs. However, cotreatment with cPA inhibited this downregulation of HDAC2 expression. Interestingly, treatment with AGP increased the expression and secretion of endogenous interleukin (IL)-6 and IL-8; however, this effect was inhibited when HCAECs were cotreated with cPA or the synthetic peroxisome proliferator-activator receptor gamma (PPARγ) antagonist T0070907. Thus, our data suggested that cPA may have beneficial effects in inflammation-related cardiovascular disease by controlling HDAC2 regulation.

  13. Searches for new alkylation catalysts, processes forge ahead

    SciTech Connect

    Rhodes, A.

    1994-08-22

    As a result of the hazardous properties of hydrofluoric acid (HF), HF alkylation has been the subject of much recent controversy. The safety and environmental requirements associated with the HF alkylation processes continue to drive industry to develop new alkylation technologies. In fact, several major process licensors are well on their ways to bringing these new technologies to market. The new alkylation processes under development center around new, less-harmful catalysts. Although this work is progressing rapidly, an update of the status of some of these new processes will keep refiners abreast of the new options they may soon have for building new alkylation units or retrofitting existing ones. The process development and economics are described for a Topsoe/Kellogg fixed bed alkylation process and the Kerr-McGee homogeneous alkylation technology process.

  14. Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base.

    PubMed

    Kawashima, Aki; Shu, Shuangjie; Takeda, Ryosuke; Kawamura, Akie; Sato, Tatsunori; Moriwaki, Hiroki; Wang, Jiang; Izawa, Kunisuke; Aceña, José Luis; Soloshonok, Vadim A; Liu, Hong

    2016-04-01

    Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is in extremely high demand due to the pharmaceutical importance of this tailor-made, sterically constrained α-amino acid. Here we report the development of an advanced procedure for preparation of the target amino acid via two-step SN2 and SN2' alkylation of novel axially chiral nucleophilic glycine equivalent. Excellent yields and diastereoselectivity coupled with reliable and easy scalability render this method of immediate use for practical synthesis of (1R,2S)-vinyl-ACCA.

  15. LATE POISONING WITH CHLOROFORM AND OTHER ALKYL HALIDES IN RELATIONSHIP TO THE HALOGEN ACIDS FORMED BY THEIR CHEMICAL DISSOCIATION

    PubMed Central

    Graham, Evarts A.

    1915-01-01

    The central lobular necrosis in the liver, which has been regarded by some writers as characteristic of late chloroform poisoning, has been produced experimentally with a number of other drugs. It is, therefore, in no sense peculiar to chloroform poisoning. Substances which have been shown to produce a morphological picture indistinguishable from that of late chloroform poisoning are: (a) dichlor- and tetrachlormethane, (b) tribrom- and triiodomethane, (c) monochlor-, monobrom-, and monoiodoethane, also the dibromethane; that is, in general, the halogen substituted aliphatic hydrocarbons containing one or two carbon atoms. Presumably similar results might be obtained with the higher members of the same series. The mechanism by which chloroform produces its characteristic tissue changes must accordingly be considered as a group reaction. Outside the body the similarities between the chemical behavior of different members of this group have been correlated by Nef on the basis of the type of dissociation which these substances undergo and the differences in their behavior on the basis of the differences of the degree to which such dissociations occur. According to the work of Nef, the group of substances under discussion has the property of dissociating to yield a halogen acid and an unsaturated alkylidene rest. Thus with chloroform the type of dissociation may be expressed thus: See PDF for Equation In this paper the view is developed that the changes characteristic of late poisonings with the above named group, namely edema, multiple hemorrhages, fat infiltration, and necrosis are ascribable (1) to acids and (2) to the fact that the amount of acid formed parallels the chemical dissociability of the drug outside of the body. Favoring the view that acid is responsible for the changes are the following observations. 1. All the characteristic features of late chloroform poisoning have been produced merely by the administration of hydrochloric acid, except, however, for

  16. Electrocatalytic activities of cathode electrodes for water electrolysis using tetra-alkyl-ammonium-sulfonic acid ionic liquid as electrolyte

    NASA Astrophysics Data System (ADS)

    Fiegenbaum, Fernanda; de Souza, Michèle O.; Becker, Márcia R.; Martini, Emilse M. A.; de Souza, Roberto F.

    2015-04-01

    The hydrogen evolution reaction (HER) performed with platinum (Pt), nickel (Ni), stainless steel 304 (SS) or glassy carbon (GC) cathodes in 0.1 M 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS.BF4) solution is studied using quasi-potentiostatic and impedance spectroscopy techniques. The objective is to compare the catalytic effect on the cathode using different materials to obtain hydrogen by water electrolysis. Furthermore, the catalytic effect of the ionic liquid (IL) on the cathode compared with that of a hydrochloric acid (HCl) solution with same pH value (0.8) is reported. A low activation energy (Ea) of 8.7 kJ mol-1 is found for the glassy carbon cathode. Tafel plots obtained with TEA-PS.BF4 IL suggest the formation of an electroactive layer of IL on the cathode, which may be responsible for the catalytically enhanced performance observed.

  17. Alkylation of isobutane with light olefins: Yields of alkylates for different olefins

    SciTech Connect

    Albright, L.F.; Kranz, K.E.; Masters, K.R.

    1993-12-01

    For alkylation of isobutane with C{sub 3}-C{sub 5} olefins using sulfuric acid as the catalyst, the yields of alkylates with different olefins are compared as the operating conditions are changed. The results of recent pilot plant experiments with propylene, C{sub 4} olefins, and C{sub 5} olefins permit such comparisons. The yields expressed as weight of alkylate produced per 100 wt of olefin consumed varied from about 201:100 to 220:100. Weight ratios of the isobutane consumed per olefin consumed vary from about 101:100 to 120:100. differences of yield values are explained by the changes in the overall chemistry. The procedure employed to calculate yields with good accuracy is based on the analysis of the alkylate and the amount of conjunct polymers produced. Based on literature data, yields are also reported for alkylations using HF as the catalyst.

  18. Effects of alkyl polyglycoside, a nonionic surfactant, and forage-to-concentrate ratio on rumen fermentation, amino acid composition of rumen content, bacteria and plasma in goats.

    PubMed

    Zeng, Bo; Tan, Zhiliang; Tang, Shaoxun; Han, Xuefeng; Tan, Chuanyan; Zhong, Rongzhen; Hea, Zhixiong; Arigbede, Oluwasanmi Moses

    2011-06-01

    In the present study, the effects of different forage-to-concentrate ratios (F:C) and an alkyl polyglycoside (APG) supplementation on parameters of rumen and blood metabolism were investigated in goats. A 2 x 2 factorial experiment was arranged within a 4 x 4 Latin square design (four 22-day periods), using four wether goats equipped with permanent ruminal cannulas. The experimental diets included two F:C levels (40:60 vs. 60:40), and two APG supplementation levels (None or 13 ml APG daily per animal). Rumen contents and blood samples were collected at the end of each period. Dietary F:C alteration affected plasma urea and influenced the proportions of leucine, histidine, arginine, glycine, proline, alanine, valine, phenylalanine, cysteine and tyrosine in rumen content, and the proportions of methionine, threonine and proline in solid-associated bacteria (SAB) significantly. Dietary APG decreased the proportions of valine and phenylalanine in rumen content, and the histidine content of liquid-associated bacteria. The interaction between dietary F:C and APG was significant for the proportions of glycine and alanine in rumen content, and the proportions of lysine and threonine in SAB. The proportion of lysine was greater, but the proportion of threonine was less in SAB for goats fed high F:C diet without APG supplementation. The proportions of plasma free amino acids and glucose concentration were not affected by experimental treatments. These results indicated that dietary APG addition affected the amino acid composition of the rumen content and ruminal bacteria, but this depended on the dietary F:C ratio. It is necessary to validate the effectiveness of dietary APG supplementation in further studies with more animals.

  19. The Alkylation of Nucleic Acids of Rat and Mouse In Vivo by the Carcinogen 1,2-Dimethylhydrazine

    PubMed Central

    Hawks, A.; Magee, P. N.

    1974-01-01

    1,2-Dimethylhydrazine, in contrast to 1-methylhydrazine, is a potent carcinogen for the colon in rats and mice. 1,2-[14C]Dimethylhydrazine was administered to rats and mice in doses which are carcinogenic following a single dose in the former species, or carcinogenic on repeated administration in the latter species, and the rate of 14CO2 exhalation was measured. Exhalation of 14CO2 was also studied after administration of single doses of 1-[14C]methylhydrazine to mice. Incorporation of radioactivity into the nucleic acids of a variety of organs was found at a time after injection (about 6 h) when 14CO2 production from both compounds was virtually complete. Methylation of nucleic acids of liver and colon, as indicated by the formation of 7-methylguanine, was observed after treatment with 1,2-dimethylhydrazine and to a smaller extent by a factor of about 10 after treatment with 1-methylhydrazine. Less than 1% of a single dose of 1,2-[14C]dimethylhydrazine was excreted in the bile of rats as determined by chemical and radioactivity assays. The similarities of the biological and biochemical actions of 1,2-dimethylhydrazine with those of some nitroso compounds and of cycasin (methylazoxymethanol glucoside) are emphasized. PMID:4469196

  20. Friedel-Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates. Efficient synthesis of highly fluorescent diethyl 1-(pyrene-1-carboxamido)alkylphosphonates and 1-(pyrene-1-carboxamido)methylphosphonic acid.

    PubMed

    Wrona-Piotrowicz, Anna; Zakrzewski, Janusz; Gajda, Anna; Gajda, Tadeusz; Makal, Anna; Brosseau, Arnaud; Métivier, Rémi

    2015-01-01

    Friedel-Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates promoted by trifluoromethanosulfonic acid afforded diethyl 1-(pyrene-1-carbothioamido)alkylphosphonates in 83-94% yield. These compounds were transformed, in 87-94% yield, into the corresponding diethyl 1-(pyrene-1-carboxamido)alkylphosphonates by treatment with Oxone(®). 1-(Pyrene-1-carboxamido)methylphosphonic acid was obtained in a 87% yield by treating the corresponding diethyl phosphonate with Me3Si-Br in methanol. All of the synthesized amidophosphonates were emissive in solution and in the solid state. The presence of a phosphonato group brought about an approximately two-fold increase in solution fluorescence quantum yield in comparison with that of a model N-alkyl pyrene-1-carboxamide. This effect was tentatively explained by stiffening of the amidophosphonate lateral chain which was caused by the interaction (intramolecular hydrogen bond) of phosphonate and amide groups. The synthesized phosphonic acid was soluble in a biological aqueous buffer (PBS, 0.01 M, pH 7.35) and was strongly emissive under these conditions (λem = 383, 400 nm, τ = 18.7 ns, ΦF > 0.98). Solid-state emission of diethyl 1-(pyrene-1-carboxamido)methylphosphonate (λmax = 485 nm; ΦF = 0.25) was assigned to π-π aggregates, the presence of which was revealed by single-crystal X-ray diffraction analysis.

  1. Study of the resistance of SAMs on aluminium to acidic and basic solutions using dynamic contact angle measurement.

    PubMed

    Liakos, Ioannis L; Newman, Roger C; McAlpine, Eoghan; Alexander, Morgan R

    2007-01-30

    We report the development of a method to determine the aqueous stability of self-assembled monolayers (SAMs) using the Wilhelmy plate dynamic contact angle (DCA) experiment. The DCA is measured in solutions over a range of pH values for alkyl carboxylic and alkyl phosphonic acid SAMs formed on magnetron-sputtered aluminum. The change in DCA on repeated immersion is used as a measure of the degradation of the SAMs by hydrolytic attack. The short and intermediate chain length alkyl acids are not stable in water of neutral pH, whereas molecules with the longest alkyl chains show considerably greater stability in neutral and both high and low pH solutions. The packing density inferred from the DCA and the contact angle hysteresis suggests the C18CO2H monolayer to be slightly less well packed than that of the C18P(=O)(OH)2; this is consistent with related friction force microscopy and infrared reflection absorption spectroscopy findings published elsewhere (Foster, T. T.; Alexander, M. R.; Leggett, G. J.; McAlpine, E. Langmuir 2006, 22, 9254-9259). The resistance of the SAMs to acid and alkaline environments is discussed in the context of aluminum oxide solubility, SAM packing density, and the resistance of the interfacial phosphate and carboxylate functionalities to different aqueous conditions.

  2. Diversity and abundance of phosphonate biosynthetic genes in nature

    PubMed Central

    Yu, Xiaomin; Doroghazi, James R.; Janga, Sarath C.; Zhang, Jun Kai; Circello, Benjamin; Griffin, Benjamin M.; Labeda, David P.; Metcalf, William W.

    2013-01-01

    Phosphonates, molecules containing direct carbon–phosphorus bonds, compose a structurally diverse class of natural products with interesting and useful biological properties. Although their synthesis in protozoa was discovered more than 50 y ago, the extent and diversity of phosphonate production in nature remains poorly characterized. The rearrangement of phosphoenolpyruvate (PEP) to phosphonopyruvate, catalyzed by the enzyme PEP mutase (PepM), is shared by the vast majority of known phosphonate biosynthetic pathways. Thus, the pepM gene can be used as a molecular marker to examine the occurrence and abundance of phosphonate-producing organisms. Based on the presence of this gene, phosphonate biosynthesis is common in microbes, with ∼5% of sequenced bacterial genomes and 7% of genome equivalents in metagenomic datasets carrying pepM homologs. Similarly, we detected the pepM gene in ∼5% of random actinomycete isolates. The pepM-containing gene neighborhoods from 25 of these isolates were cloned, sequenced, and compared with those found in sequenced genomes. PEP mutase sequence conservation is strongly correlated with conservation of other nearby genes, suggesting that the diversity of phosphonate biosynthetic pathways can be predicted by examining PEP mutase diversity. We used this approach to estimate the range of phosphonate biosynthetic pathways in nature, revealing dozens of discrete groups in pepM amplicons from local soils, whereas hundreds were observed in metagenomic datasets. Collectively, our analyses show that phosphonate biosynthesis is both diverse and relatively common in nature, suggesting that the role of phosphonate molecules in the biosphere may be more important than is often recognized. PMID:24297932

  3. Gallium(III) complexes of NOTA-bis (phosphonate) conjugates as PET radiotracers for bone imaging.

    PubMed

    Holub, Jan; Meckel, Marian; Kubíček, Vojtěch; Rösch, Frank; Hermann, Petr

    2015-01-01

    Ligands with geminal bis(phosphonic acid) appended to 1,4,7-triazacyclonone-1,4-diacetic acid fragment through acetamide (NOTAM(BP) ) or methylenephosphinate (NO2AP(BP) ) spacers designed for (68) Ga were prepared. Ga(III) complexation is much faster for ligand with methylenephosphinate spacer than that with acetamide one, in both chemical (high reactant concentrations) and radiolabeling studies with no-carrier-added (68) Ga. For both ligands, formation of Ga(III) complex was slower than that with NOTA owing to the strong out-of-cage binding of bis(phosphonate) group. Radiolabeling was efficient and fast only above 60 °C and in a narrow acidity region (pH ~3). At higher temperature, hydrolysis of amide bond of the carboxamide-bis(phosphonate) conjugate was observed during complexation reaction leading to Ga-NOTA complex. In vitro sorption studies confirmed effective binding of the (68) Ga complexes to hydroxyapatite being comparable with that found for common bis(phosphonate) drugs such as pamindronate. Selective bone uptake was confirmed in healthy rats by biodistribution studies ex vivo and by positron emission tomography imaging in vivo. Bone uptake was very high, with SUV (standardized uptake value) of 6.19 ± 1.27 for [(68) Ga]NO2AP(BP) ) at 60 min p.i., which is superior to uptake of (68) Ga-DOTA-based bis(phosphonates) and [(18) F]NaF reported earlier (SUV of 4.63 ± 0.38 and SUV of 4.87 ± 0.32 for [(68) Ga]DO3AP(BP) and [(18) F]NaF, respectively, at 60 min p.i.). Coincidently, accumulation in soft tissue is generally low (e.g. for kidneys SUV of 0.26 ± 0.09 for [(68) Ga]NO2AP(BP) at 60 min p.i.), revealing the new (68) Ga complexes as ideal tracers for noninvasive, fast and quantitative imaging of calcified tissue and for metastatic lesions using PET or PET/CT.

  4. Phase Behavior and Conductivity of Phosphonated Block Copolymers Containing Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Jung, Ha Young; Kim, Sung Yeon; Park, Moon Jeong

    2015-03-01

    As the focus on proton exchange fuel cells continues to escalate in the era of alternative energy systems, the rational design of sulfonated polymers has emerged as a key technique for enhancing device efficiency. While the sulfonic acid group guarantees high proton conductivity of membranes under humidified conditions, the growing need for high temperature operation has discouraged their practical uses in fuel cells. In this respect, phosphonated polymers have drawn intensive attention in recent years owing to their self-dissociation ability. In this study, we have synthesized a set of phosphonated block copolymers, poly(styrenephosphonate-methylbutylene) (PSP- b - PMB), by varying phosphonation level (PL). A wide variety of self-assembled morphologies, i.e., disordered, lamellar, hexagonally perforated lamellae and hexagonally packed cylindrical phases, were observed with PL. Remarkably, upon comparing the morphology of PSP- b-PMB and that of sulfonated analog, we found distinctly dissimilar domain sizes at the same molecular weight and composition. A range of ionic liquids (ILs) were incorporated into the PSP- b-PMB block copolymers and their ion transport properties were examined. It has been revealed that the degree of confinement of ionic phases (domain size) impacts the ion mobility and proton dissociation efficiency of IL-containing polymers.

  5. From chain collapse to new structures: spectroscopic properties of poly(3-thiophene acetic acid) upon binding by alkyl trimethylammonium bromide surfactants.

    PubMed

    Franco, I Echavarri; Lorchat, P; Lamps, J-P; Schmutz, M; Schröder, A; Catala, J-M; Combet, J; Schosseler, F

    2012-03-13

    The binding of cationic surfactants with varying alkyl chain length to a regiorandom conjugated polyanion, poly(3-thiophene acetic acid) (PTAA), is studied in an aqueous buffer by using absorption and emission spectroscopies, photon correlation spectroscopy, isothermal titration calorimetry, and cryogenic transmission electron microscopy. We study the mixed solutions as a function of composition ratio R of surfactant molecules to monomer units molar concentrations, at low polymer concentration and in a very wide composition range (10(-6) < R < 10(2)) below the critical micellar concentration. Upon surfactant binding, the molecularly dispersed chains first collapse progressively and then form new structures as the mixed aggregates get enriched in surfactant. The collapse leads to a strong decrease of the conjugation length and to a blue shift of the absorption spectra by 30 to 50 nm. The new structures are responsible for a new intense emission band at about 600 nm, red-shifted by nearly 130 nm from the initial emission maximum of the polymer (~472 nm). As the surfactant tail becomes shorter, the blue shift of the absorption spectra and the intensity raise of the new emission are delayed to larger composition ratios while their variations become smoother functions of the surfactant concentration. These particular spectroscopic properties of PTAA seem related to its unique combination of a strongly hydrophobic backbone, a large ratio of contour length to persistence length, and an overall good aqueous solubility. Our results show that such features are well suited to design a colorimetric biosensor at small composition ratio, and a fluorescent biomarker at large composition ratio.

  6. Structure of the Escherichia coli Phosphonate Binding Protein PhnD and Rationally Optimized Phosphonate Biosensors

    PubMed Central

    Alicea, Ismael; Marvin, Jonathan S.; Miklos, Aleksandr E.; Ellington, Andrew D.; Looger, Loren L.; Schreiter, Eric R.

    2012-01-01

    The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by ~70° between the two states. Extensive hydrogen bonding and electrostatic interactions stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into phosphonate uptake by bacteria and facilitated the rational design of high signal-to-noise phosphonate biosensors based both on coupled small molecule dyes and autocatalytic fluorescent proteins. PMID:22019591

  7. [Molluscacide activity of a mixture of 6-n-alkyl salicylic acids (anacardic acid) and 2 of its complexes with copper (II) and lead (II)].

    PubMed

    Mendes, N M; de Oliveira, A B; Guimarães, J E; Pereira, J P; Katz, N

    1990-01-01

    The molluscicide activity of hexanic extract from Anacardium occidentale L. (cashew) nut shell, of copper (II) complex, of lead (II) complex and anacardic acid has been compared in the laboratory in an attempt to obtain better stability than anacardic acid. This was obtained from the hexanic extract of the cashew nut shell by precipitation with lead (II) hydroxide or cupric sulfate plus sodium hydroxide or (II) cupric hydroxide followed by treatment of lead (II) complex with a diluted solution of sulfuric acid. Ten products of the mixture obtained were tested on adults snails of Biomphalaria glabrata at 1 to 10 ppm. The most active products were copper (II) complex, obtained by cupric sulfate plus sodium hydroxide, and anacardic acid (sodium hydroxide) which presented activity at 4 ppm. The anacardic acid's lead content was above the limits accepted by the United States standards.

  8. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOEpatents

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  9. Two di-alkyl-ammonium salts of 2-amino-4-nitro-benzoic acid: crystal structures and Hirshfeld surface analysis.

    PubMed

    Wardell, James L; Jotani, Mukesh M; Tiekink, Edward R T

    2016-12-01

    The crystal structures of two ammonium salts of 2-amino-4-nitro-benzoic acid are described, namely di-methyl-aza-nium 2-amino-4-nitro-benzoate, C2H8N(+)·C7H5N2O4(-), (I), and di-butyl-aza-nium 2-amino-4-nitro-benzoate, C8H20N(+)·C7H5N2O4(-), (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl-ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti-periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl-ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra-molecular chain by charge-assisted amine-N-H⋯O(carboxyl-ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N-O⋯π(arene) and methyl-C-H⋯O(nitro) inter-actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N-H⋯O(carboxyl-ate) hydrogen bonding. The formation of ammonium

  10. A comparison of the solvation thermodynamics of amino acid analogues in water, 1-octanol and 1-n-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids by molecular simulation

    NASA Astrophysics Data System (ADS)

    Paluch, Andrew S.; Vitter, Cameron A.; Shah, Jindal K.; Maginn, Edward J.

    2012-11-01

    A computational approach is developed to quantitatively study the solvation thermodynamics of amino acid analogues in ionic liquids via molecular simulation. The solvation thermodynamics of amino acid analogues in ionic liquids is important for an understanding of protein-ionic liquid interactions, shedding insight into the structure and solubility of proteins, and the activity of enzymes in ionic liquids. This information is additionally key to developing novel extraction processes. As a result of the challenge of quantitatively describing the solvation behavior of ionic liquids, a key outcome of the present study is the development of a "hydrophobicity" scale to quantitatively describe the amino acid analogues. The scale allows one to separate the results of both the hydrophobic and hydrophillic analogues, simplifying an understanding of the observed trends. Equipped with the proposed hydrophobicity scale, one needs only perform conventional solvation free energy calculations of the amino acid analogues in the ionic liquids of interest. The necessary simulation tools are available in most open-source simulation software, facilitating the adoption of this approach by the simulation community at large. We have studied the case of varying the cation alkyl-chain length of a 1-n-alkyl-3-methylimidazolium cation paired with the bis(trifluoromethylsulfonyl)imide anion. The findings suggest that a judicious selection of both the cation and anion could potentially lead to a solvent for which the amino acid analogues have an affinity far greater than that for both water and a non-polar reference solvent.

  11. Chemoselective recognition with phosphonate cavitands: the ephedrine over pseudoephedrine case.

    PubMed

    Biavardi, Elisa; Ugozzoli, Franco; Massera, Chiara

    2015-02-25

    Complete discrimination of ephedrine and pseudoephedrine, both in solution and in the solid state, was achieved with a phosphonate cavitand receptor. The molecular origin of the epimer discrimination was revealed by the crystal structure of the respective complexes.

  12. Betulin Phosphonates; Synthesis, Structure, and Cytotoxic Activity.

    PubMed

    Chrobak, Elwira; Bębenek, Ewa; Kadela-Tomanek, Monika; Latocha, Małgorzata; Jelsch, Christian; Wenger, Emmanuel; Boryczka, Stanisław

    2016-08-26

    Betulin derivatives are a widely studied group of compounds of natural origin due to their wide spectrum of biological activities. This paper describes new betulin derivatives, containing a phosphonate group. The allyl-vinyl isomerization and synthesis of acetylenic derivatives have been reported. Structural identification of products as E and Z isomers has been carried out using ¹H-, (13)C-, (31)P-NMR, and crystallographic analysis. The crystal structure in the orthorhombic space group and analysis of crystal packing contacts for 29-diethoxyphosphoryl-28-cyclopropylpropynoyloxy-lup-20E(29)-en-3β-ol 8a are reported. All new compounds were tested in vitro for their antiproliferative activity against human T47D (breast cancer), SNB-19 (glioblastoma), and C32 (melanoma) cell lines.

  13. Synthesis of phosphonate and phostone analogues of ribose-1-phosphates

    PubMed Central

    Nasomjai, Pitak; Slawin, Alexandra M Z

    2009-01-01

    Summary The synthesis of phosphonate analogues of ribose-1-phosphate and 5-fluoro-5-deoxyribose-1-phosphate is described. Preparations of both the α- and β-phosphonate anomers are reported for the ribose and 5-fluoro-5-deoxyribose series and a synthesis of the corresponding cyclic phostones of each α-ribose is also reported. These compounds have been prepared as tools to probe the details of fluorometabolism in S. cattleya. PMID:19777136

  14. A new chiral uranyl phosphonate framework consisting of achiral building units generated from ionothermal reaction: structure and spectroscopy characterizations.

    PubMed

    Zheng, Tao; Gao, Yang; Chen, Lanhua; Liu, Zhiyong; Diwu, Juan; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2015-11-07

    The ionothermal reactions of uranyl nitrate and 1,3-pbpH4 (1,3-pbpH4 = 1,3-phenylenebis(phosphonic acid) ligand in ionic liquids of [C4mim][Dbp], [C4mpyr][Br], and [Etpy][Br], respectively, afforded three new uranyl phosphonates, namely [C4mim][(UO2)2(1,3-pbpH)(1,3-pbpH)·Hmim] (1), [UO2(1,3-pbpH2)H2O·mpr] (2), and [Etpy][UO2(1,3-pbpH2)F] (3). Compound 1 exhibits a rare example of a chiral uranyl phosphonate 3D framework structure built from achiral building units of tetragonal bipyramidal uranium polyhedra and 1,3-pbp ligands. The structure adopts a network with channels extending along the b axis, which are filled with C4mim(+) and protonated 1-methylimidazole. In sharp contrast, compounds 2 & 3 both show pillared topology composed of uranyl pentagonal bipyramid polyhedra and phosphonate ligands. The layers are neutral in compound 2 with N-methylpyrrole molecules in the interlayer space, while compound 3 adopts anionic layer, and the charge is compensated with N-ethyl-pyridinium cations between the layers. Although compounds 1, 2, and 3 were synthesized under identical conditions with sole variation of the ionic liquid species, the resulting structures show a rich diversity in the local coordination environment of uranyl ions, the protonation of the phosphonate ligand, the conformation of ionic liquid ions, and the overall arrangement of the structure. All compounds were characterized by absorption, temperature dependent fluorescence, as well as infrared and Raman spectroscopies.

  15. Sorption of Perfluoroalkyl Phosphonates and Perfluoroalkyl Phosphinates in Soils.

    PubMed

    Lee, Holly; Mabury, Scott Andrew

    2017-02-22

    Perfluoroalkyl phosphonates (PFPAs) and perfluoroalkyl phosphinates (PFPiAs) are recently discovered perfluoroalkyl acids (PFAAs) that have been widely detected in house dust, aquatic biota, surface water, and wastewater environments. The sorption of C6, C8, and C10 monoalkylated PFPAs and C6/C6, C6/C8, and C8/C8 dialkylated PFPiAs was investigated in seven soils of varying geochemical parameters. Mean distribution coefficients, logKd*, ranged from 0.2 to 2.1 for the PFPAs and PFPiAs and were generally observed to increase with perfluoroalkyl chain length. The logKd* of PFPiAs calculated here (1.6-2.1) were similar to those previously measured for the longer-chain perfluorodecane sulfonate (1.9, PFDS) and perfluoroundecanoate (1.7, PFUnA) in sediments, but overall when compared as a class, were greater than those for the perfluoroalkane sulfonates (-0.8-1.9, PFSAs), perfluoroalkyl carboxylates (-0.4-1.7, PFCAs), and PFPAs (0.2-1.5). No single soil-specific parameter, such as pH and organic carbon content, was observed to control the sorption of PFPAs and PFPiAs, the lack of which may be attributed to competing interferences in the naturally heterogeneous soils. The PFPAs were observed to desorb to a greater extent and likely circulate as aqueous contaminants in the environment, while the more sorptive PFPiAs would be preferentially retained by environmental solid phases.

  16. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  17. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  18. Differential effects of phosphonic analogues of GABA on GABA(B) autoreceptors in rat neocortical slices.

    PubMed

    Ong, J; Marino, V; Parker, D A; Kerr, D I

    1998-04-01

    The effects of five phosphonic derivatives of GABA on the release of [3H]-GABA from rat neocortical slices, preloaded with [3H]-GABA, were investigated. Phaclofen and 4-aminobutylphosphonic acid (4-ABPA) increased the overflow of [3H] evoked by electrical stimulation (2 Hz) in a concentration-dependent manner, with similar potencies (phaclofen EC50=0.3 mmol/l, 4-ABPA EC50=0.4 mmol/l). At 3 mmol/l, phaclofen increased the release of [3H]-GABA by 82.6+/-8.6%, and 4-ABPA increased the release by 81.3+/-9.0%. 2-Amino-ethylphosphonic acid (2-AEPA) increased the overflow of [3H] by 46.8+/-10.9% at the highest concentration tested (3 mmol/l). In contrast, the lower phosphonic homologue 3-aminopropylphosphonic acid (3-APPA), and 2-amino-2-(p-chlorophenyl)-ethylphosphonic acid (2-CPEPA), a baclofen analogue, did not modify the stimulated overflow. These results suggest that phaclofen, 4-ABPA and 2-AEPA are antagonists at GABA(B) autoreceptors, the latter being the weakest antagonist, whilst neither 3-APPA nor 2-CPEPA are active at these receptors. Since phaclofen, 4-ABPA and 2-CPEPA are antagonists and 3-APPA a partial agonist/antagonist on GABA(B) heteroreceptors, the lack of effect of 3-APPA and 2-CPEPA on [3H]-GABA release in this study suggests that GABA(B) autoreceptors may be pharmacologically distinct from the heteroreceptors.

  19. Tunneling Spectroscopy Studies of Urea, Thiourea, and Selected Phosphonate Molecules Adsorbed on Aluminum Oxide

    NASA Astrophysics Data System (ADS)

    Crowder, Charles D.

    Experimental and calculated inelastic electron tunneling intensities were compared for several of the vibrational modes of thiourea adsorbed on aluminum oxide. The partial charge model of Kirtley, Scalapino, and Hansma was used to compute the theoretical intensities of each mode. The required partial charges were determined using a method developed by Momany. Essentially, the Coulomb potential resulting from point charges located at atom sites was fitted to the quantum mechanical electrostatic potential of a molecule calculated from Hartree-Fock theory. The effect of a vibrational mode pattern on the electrostatic potential of a molecule was investigated. This effect could not be acceptably modeled with a single point charge located on each atom, so one charge was used to represent the positive nucleus of each atom and a second charge was used to represent the valence cloud. The valence charge was allowed to move independently of the nuclear charge during a molecular vibration, and the motions of the two charges were found to be very different for hydrogen atoms. This model gave very reasonable agreement between the theoretical and observed relative intensities for the in plane vibrational modes of thiourea. An acceptable set of out of plane force constants could not be found. This caused problems in the interpretation of the out of plane relative intensities. Based on the in plane modes, it was concluded that thiourea bonded to aluminum oxide with the sulfur atom near the oxide and the sulfur-carbon bond perpendicular to the aluminum oxide surface. Quantum mechanical electrostatic potentials were also calculated for urea, phosphoric acid (PA), methylphosphonic acid (MPA), hydroxymethylphosphonic acid (HMP), and nitrotrismethylphosphonic acid (NTMP). Electron tunneling spectra were taken for PA, HMP and NTMP, and the observed frequencies were compared to values obtained from Fourier transform infrared, infrared and Raman spectroscopy. Upward shifts in the P=O and P

  20. Iron-Catalyzed C-H Alkylation of Heterocyclic C-H Bonds.

    PubMed

    Babu, Kaki Raveendra; Zhu, Nengbo; Bao, Hongli

    2017-01-06

    An efficient, iron-catalyzed C-H alkylation of benzothiazoles by using alkyl diacyl peroxides and alkyl tert-butyl peresters which are readily accessible from carboxylic acids to synthesize 2-alkylbenzothiazoles is developed. This reaction is environmentally benign and compatible with a broad range of functional groups. Various primary, secondary, and tertiary alkyl groups can be efficiently incorporated into diverse benzothiazoles. The effectiveness of this method is illustrated by late-stage functionalization of biologically active heterocycles.

  1. Transition metal-free decarboxylative alkylation reactions.

    PubMed

    Liu, Ping; Zhang, Guanghui; Sun, Peipei

    2016-11-22

    This review summarizes advances in the decarboxylative alkylation of carboxylic acids and their derivatives under transition metal-free conditions in recent years. Unlike most transition metal-catalyzed decarboxylative coupling reactions which tend to undergo catalytic cycles, the mechanisms of reactions under metal-free conditions are usually diverse and even ambiguous in some cases. This article offers an overview of reaction types and their corresponding mechanisms, highlights some of the advantages and limitations, and focuses on introducing UV and visible light-induced, organocatalyst and peroxide promoted radical processes for decarboxylative alkylation and the formation of C-C bonds.

  2. Alkyl ferulates in wound healing potato tubers.

    PubMed

    Bernards, M A; Lewis, N G

    1992-10-01

    Seven ferulic acid esters of 1-alkanols ranging in carbon length from C16 to C28 were synthesized and an HPLC protocol for their separation developed. Extracts prepared from wound healing potato (Solanum tuberosum) tubers and analysed by HPLC indicated that alkyl ferulate esters begin to accumulate 3-7 days after wound treatment. Of the nine esters identified by EIMS, (including two esters of odd chain length alkanols) hexadecyl and octadecyl ferulates were predominant. Alkyl ferulate esters were restricted to the wound periderm.

  3. Mitsunobu alkylation of cancerostatic 5-fluorouridine with (2E)-10-hydroxydec-2-enoic acid, a fatty acid from royal jelly with multiple biological activities.

    PubMed

    Ottenhaus, Vanessa; Rosemeyer, Helmut

    2015-09-01

    5-Fluorouridine (1) - a nucleoside antimetabolite with strong cancerostatic properties - was protected i) at the 2'- and 3'-OH groups with a heptan-4-ylidene residue and ii) at the 5'-OH group with a (4-methoxyphenyl)(diphenyl)methyl residue. This fully protected compound, 3, was submitted to a Mitsunobu reaction with the N-hydroxysuccinimide (NHS) ester, 5, of (2E)-10-hydroxydec-2-enoic acid (4) which gave nucleolipid 6. The latter was detritylated with Cl2 CHCOOH to yield the co-drug 7 as NHS ester.

  4. Asymmetric hydrogenation of alpha,beta-unsaturated phosphonates with Rh-BisP* and Rh-MiniPHOS catalysts: scope and mechanism of the reaction.

    PubMed

    Gridnev, Ilya D; Yasutake, Masaya; Imamoto, Tsuneo; Beletskaya, Irina P

    2004-04-13

    Optically active 1,2-bis(alkylmethylphosphino)ethanes and bis(alkylmethylphosphino)methanes are unique diphosphine ligands combining the simple molecular structure and P-stereogenic asymmetric environment. This work shows that these ligands exhibit excellent enantioselectivity in rhodium-catalyzed asymmetric hydrogenation of alpha,beta-unsaturated phosphonic acid derivatives. The enantioselective hydrogenation mechanism elucidated by NMR study is also described.

  5. A layered mixed zirconium phosphate/phosphonate with exposed carboxylic and phosphonic groups: X-ray powder structure and proton conductivity properties.

    PubMed

    Donnadio, Anna; Nocchetti, Morena; Costantino, Ferdinando; Taddei, Marco; Casciola, Mario; da Silva Lisboa, Fábio; Vivani, Riccardo

    2014-12-15

    A novel mixed zirconium phosphate/phosphonate based on glyphosine, of formula Zr2(PO4)H5(L)2·H2O [L = (O3PCH2)2NCH2COO], was synthesized in mild conditions. The compound has a layered structure that was solved ab initio from laboratory PXRD data. It crystallizes in the monoclinic C2/c space group with the following cell parameters: a = 29.925(3), b = 8.4225(5), c = 9.0985(4) Å, and β = 98.474(6)°. Phosphate groups are placed inside the sheets and connect the zirconium atoms in a tetradentate fashion, while uncoordinated carboxylate and P-OH phosphonate groups are exposed on the layer surface. Due to the presence of these acidic groups, the compound showed remarkable proton conductivity properties, which were studied in a wide range of temperature and relative humidity (RH). The conductivity is strongly dependent on RH and reaches 1 × 10(-3) S cm(-1) at 140 °C and 95% RH. At this RH, the activation energy of conduction is 0.15 eV in the temperature range 80-140 °C. The similarities of this structure with related structures already reported in the literature were also discussed.

  6. Synthesis Of Alkyl Hydroperoxides Via Alkylation Of gem-Dihydroperoxides

    PubMed Central

    Kyasa, ShivaKumar; Puffer, Benjamin W.

    2013-01-01

    Two-fold alkylation of 1,1-dihydroperoxides, followed by hydrolysis of the resulting bisperoxyacetals, provides a convenient method for synthesis of primary and secondary alkyl hydroperoxides. PMID:23469994

  7. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  8. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  9. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  10. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  11. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  12. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  13. Ligand-promoted alkylation of C(sp3)-H and C(sp2)-H bonds.

    PubMed

    Zhu, Ru-Yi; He, Jian; Wang, Xiao-Chen; Yu, Jin-Quan

    2014-09-24

    9-Methylacridine was identified as a generally effective ligand to promote a Pd(II)-catalyzed C(sp(3))-H and C(sp(2))-H alkylation of simple amides with various alkyl iodides. This alkylation reaction was applied to the preparation of unnatural amino acids and geometrically controlled tri- and tetrasubstituted acrylic acids.

  14. Low-risk gasoline alkylation process using a homogeneous liquid phase catalyst

    SciTech Connect

    Nelson, S.R.; Nelson, L.G.

    1996-12-31

    Kerr-McGee`s interest in finding additional applications for its ROSES technology has led to a promising new alkylation process for the production of gasoline. The technology is timely due to its inherent environmental safety. The Homogeneous Alkylation Technology (HAT{trademark}) process uses a soluble alkylaluminum chloride-based catalyst at less than 1 percent of the acid concentrations used in conventional alkylation processes. The patented process greatly reduces the environmental risks associated with accidental acid releases from HF and sulfuric acid alkylation units. In addition, the process is projected to operate at lower cost than sulfuric acid alkylation and is a retrofit option for existing HF and sulfuric-acid alkylation units. Kerr-McGee has entered into a relationship with a major U.S. refiner to carry on the development of the HAT process. A gallon-per-day-scale pilot unit has been constructed for use in developing the process. 1 fig., 1 tab.

  15. Polyimide characterization studies - Effect of pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1984-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  16. Spectroscopic and structural characterization of the charge-transfer interaction of N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide with chloranilic and picric acids

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Ahmed, Hamdy A.; Grabchev, Ivo; El-Zayat, Lamia A.

    2008-09-01

    Charge-transfer (CT) complexes formed from the reactions of two N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide such as N, N'-bis[2-hydroxyethyl)]-1,4,6,8-naphthalenediimide (BHENDI) and N, N'-bis-[2- N, N-dimethylaminoethyl)]-1,4,6,8-naphthalenediimide (BDMAENDI) with chloranilic acid (CLA) and piciric acid (PA) as π-acceptors, have been studied spectrophotometrically in methanol and chloroform, respectively at 25 °C. The photometric titration curves for the reactions indicated that the data obtained refer to 1:1 charge-transfer complexes of [(BHENDI)(CLA)], [(BDMAENDI)(CLA)], [(BHENDI)(PA)] and [(BDMAENDI)(PA)] were formed. Benesi-Hildebrand and its modification methods were applied to the determination of association constant ( K), molar extinction coefficient ( ɛ). The solid CT complexes have been synthesized and characterization by different spectral methods.

  17. Anti-HIV Nucleoside Phosphonate GS-9148 and Its Prodrug GS-9131: Scale Up of a 2'-F Modified Cyclic Nucleoside Phosphonate and Synthesis of Selected Amidate Prodrugs.

    PubMed

    Mackman, Richard L

    2014-03-26

    Nucleoside phosphonate analogs are an important class of antiviral drugs for the treatment of HIV and HBV. The most recent nucleoside phosphonate to progress to clinical development is GS-9131, a cyclic nucleoside phosphonate (CNP). This unit contains procedures for the synthesis of the parent CNP 2'-Fd4AP (GS-9148) and selected monoamidate and bisamidate prodrugs, including the monoamidate clinical prodrug GS-9131. The first basic protocol of this unit details improved procedures for the preparation of 2'-Fd4AP and related phosphonate esters by introduction of a hydroxylmethyl phosphonate ester regioselectively and stereoselectively onto a furanose core via a glycal intermediate. The method described is believed to be robust and flexible, allowing for a variety of analogs with other nucleobases or furanose 2'-ring substitutions to be prepared. The preparation of monoamidate and bisamidate prodrugs either on the phosphonate diacid or its monophenyl ester is then described in the second and third basic protocols of this unit.

  18. Molecular requisites for drug binding to muscle CLC-1 and renal CLC-K channel revealed by the use of phenoxy-alkyl derivatives of 2-(p-chlorophenoxy)propionic acid.

    PubMed

    Liantonio, Antonella; Accardi, Alessio; Carbonara, Giuseppe; Fracchiolla, Giuseppe; Loiodice, Fulvio; Tortorella, Paolo; Traverso, Sonia; Guida, Patrizia; Pierno, Sabata; De Luca, Annamaria; Camerino, Diana Conte; Pusch, Michael

    2002-08-01

    CLC channels are a gene family of Cl(-) channels that serve a variety of functions, several of which are involved in genetic diseases. Few specific ligands of CLC channels are known that could be useful as pharmacological tools or potential drugs. We synthesized various derivatives of 2-(p-chlorophenoxy)propionic acid, the S(-)-enantiomer of which is a specific blocker of the muscle channel CLC-1. In particular, compounds with different alkyl or phenoxy-alkyl groups on the chiral center, isosteres of the oxygen in the aryloxy moiety, or bioisosteres of the carboxy function were prepared. We found that compounds containing a phenoxy and a phenoxy-alkyl group on the chiral center (bis-phenoxy derivatives) specifically inhibited renal CLC-K channels from the extracellular side with an affinity in the 150-microM range and with almost no effect on other CLC channels when applied from the outside. Surprisingly, the same substances inhibited CLC-1 from the intracellular side in a voltage-dependent manner with an apparent K(D) of <5 microM at -140 mV, thus being the most potent blockers of a CLC channel known so far. Although the chlorine atom in para- position of the second phenoxy group was essential for inhibition of CLC-K channels from the outside, it could be substituted by a methoxy group without changing the potency of block for CLC-1 from the inside. These newly identified substances provide powerful tools for studying the structure-function relationship and the physiological role of CLC channels and may represent a starting point for the development of useful drugs targeting CLC-K channels.

  19. Phosphonate Analogs of 2-Oxoglutarate Perturb Metabolism and Gene Expression in Illuminated Arabidopsis Leaves

    PubMed Central

    Araújo, Wagner L.; Tohge, Takayuki; Nunes-Nesi, Adriano; Daloso, Danilo M.; Nimick, Mhairi; Krahnert, Ina; Bunik, Victoria I.; Moorhead, Greg B. G.; Fernie, Alisdair R.

    2012-01-01

    Although the role of the 2-oxoglutarate dehydrogenase complex (2-OGDHC) has previously been demonstrated in plant heterotrophic tissues its role in photosynthetically active tissues remains poorly understood. By using a combination of metabolite and transcript profiles we here investigated the function of 2-OGDHC in leaves of Arabidopsis thaliana via use of specific phosphonate inhibitors of the enzyme. Incubation of leaf disks with the inhibitors revealed that they produced the anticipated effects on the in situ enzyme activity. In vitro experiments revealed that succinyl phosphonate (SP) and a carboxy ethyl ester of SP are slow-binding inhibitors of the 2-OGDHC. Our results indicate that the reduced respiration rates are associated with changes in the regulation of metabolic and signaling pathways leading to an imbalance in carbon-nitrogen metabolism and cell homeostasis. The inducible alteration of primary metabolism was associated with altered expression of genes belonging to networks of amino acids, plant respiration, and sugar metabolism. In addition, by using isothermal titration calorimetry we excluded the possibility that the changes in gene expression resulted from an effect on 2-oxoglutarate (2OG) binding to the carbon/ATP sensing protein PII. We also demonstrated that the 2OG degradation by the 2-oxoglutarate dehydrogenase strongly influences the distribution of intermediates of the tricarboxylic acid (TCA) cycle and the GABA shunt. Our results indicate that the TCA cycle activity is clearly working in a non-cyclic manner upon 2-OGDHC inhibition during the light period. PMID:22876250

  20. Paclitaxel-loaded phosphonated calixarene nanovesicles as a modular drug delivery platform

    PubMed Central

    Mo, Jingxin; Eggers, Paul K.; Yuan, Zhi-xiang; Raston, Colin L.; Lim, Lee Yong

    2016-01-01

    A modular p-phosphonated calix[4]arene vesicle (PCV) loaded with paclitaxel (PTX) and conjugated with folic acid as a cancer targeting ligand has been prepared using a thin film-sonication method. It has a pH-responsive capacity to trigger the release of the encapsulated PTX payload under mildly acidic conditions. PTX-loaded PCV conjugated with alkyne-modified PEG-folic acid ligands prepared via click ligation (fP-PCVPTX) has enhanced potency against folate receptor (FR)-positive SKOV-3 ovarian tumour cells over FR-negative A549 lung tumour cells. Moreover, fP-PCVPTX is also four times more potent than the non-targeting PCVPTX platform towards SKOV-3 cells. Overall, as a delivery platform the PCVs have the potential to enhance efficacy of anticancer drugs by targeting a chemotherapeutic payload specifically to tumours and triggering the release of the encapsulated drug in the vicinity of cancer cells. PMID:27009430

  1. Adsorption and removal kinetics of phosphonate from water using natural adsorbents.

    PubMed

    Kumar, R Anil; Velayudhan, K T; Ramachandran, V; Bhai, R Susheela; Unnikrishnan, G; Vasu, K

    2010-01-01

    The removal of phosphonate from water was studied using some natural adsorbents. Potassium phosphonate is a fungicide used for the control of Phytophthora capsici, which is prevalent in black pepper (Piper nigrum L.). Batch adsorption kinetic experiments were conducted on the adsorption of phosphonate onto the adsorbents. The concentration of phosphonate was measured on a high-performance liquid chromatograph fitted with a conductivity detector. The percentage removal of phosphonate by powdered laterite stone (PLS) from water was 40.4%, within a residence time of 15 minutes. The mechanisms of the rate of adsorption were analyzed and compared using the pseudo-second-order, Elovich, and intraparticle diffusion models. The experimental data was found to correlate well with the pseudo-second-order kinetic model, indicating adsorption as a chemisorption process. A possible reaction in the phosphonate-PLS system also has been proposed. The PLS can be used as a low-cost natural adsorbent for phosphonate removal from water.

  2. Congener-specific numbering systems for the environmentally relevant C4 through C8 perfluorinated homologue groups of alkyl sulfonates, carboxylates, telomer alcohols, olefins, and acids, and their derivatives.

    PubMed

    Rayne, Sierra; Forest, Kaya; Friesen, Ken J

    2008-10-01

    We introduce a congener-specific numbering system for the C4 through C8 perfluorinated homologue groups of alkyl sulfonates, carboxylates, telomer alcohols, olefins, and acids, and their derivatives. Increasing length of the carbon chain beyond C3 leads to a corresponding rapid increase in the number of potential isomers (C4 = 4, C5 = 8, C6 = 17, C7 = 39, and C8 = 89 congeners). There is a need for clear and unambiguous chemical shorthand to ensure accuracy and consistency in the future perfluorinated alkyl substance (PFA) literature, and to correct previous misconceptions that may have restricted research efforts into developing full-congener PFA analysis. If adopted by the research community, introduction of a numbering system at this relatively early stage of investigations into the congener-specific analysis, environmental behavior, and toxicology of PFAs would not require an arduous and difficult reassignment of historical structures and naming conventions presented in the prior art. Many PFA congeners are chiral, necessitating a consideration of their enantiospecific environmental behavior and toxicology.

  3. Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore.

    PubMed

    Biswas, Sujoy; Pathak, P N; Roy, S B

    2012-06-01

    An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λ(max)) for UO(2)(2+)-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol(-1)cm(-1)). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to > 24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO(2)(2+)-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is < 2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98-105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ± 2%. This method can be used to determine 2.5-250 μg mL(-1) uranium in ore leach solutions with high accuracy and precision.

  4. Flame retardant properties of triazine phosphonates derivative with cotton fabric

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flame retardant behavior of a cotton fabric treated with phosphorus-nitrogen containing triazine compound was evaluated. It was found that cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) is an excellent starting material for the preparation of phosphonates flame retardants that interacts wel...

  5. Solid state {sup 31}P NMR study of phosphonate binding sites in guanidine-functionalized, molecular imprinted silica xerogels

    SciTech Connect

    Sasaki, D.Y.; Alam, T.D.

    2000-01-03

    Phosphonate binding sites in guanidine and ammonium surface-functionalized silica xerogels were prepared via the molecular imprinting technique and characterized using solid state {sup 31}P MAS NMR. One-point, two-point, and non-specific host-guest interactions between phenylphosphonic acid (PPA) and the functionalized gels were distinguished by characteristic chemical shifts of the observed absorption peaks. Using solid state as well as solution phase NMR analyses, absorptions observed at 15.5 ppm and 6.5 ppm were identified as resulting from the 1:1 (one-point) and 2:1 (two-point) guanidine to phosphonate interactions, respectively. Similar absorptions were observed with the ammonium functionalized gels. By examining the host-guest interactions within the gels, the efficiency of the molecular imprinting procedure with regard to the functional monomer-to-template interaction could be readily assessed. Template removal followed by substrate adsorption studies conducted on the guanidine functionalized gels provided a method to evaluate the binding characteristics of the receptor sites to a phosphonate substrate. During these experiments, {sup 29}Si and {sup 31}P MAS NMR acted as diagnostic monitors to identify structural changes occurring in the gel matrix and at the receptor site from solvent mediated processes.

  6. Preparation and characterization of N-methylene phosphonic and quaternized chitosan composite membranes for electrolyte separations.

    PubMed

    Saxena, Arunima; Kumar, Arvind; Shahi, Vinod K

    2006-11-15

    Chitosan was functionalized either by introducing a phosphonic acid group or by quaternization of existing primary ammonium groups in order to make it a water-soluble material. Functionalized chitosans and poly(vinyl alcohol) (PVA)-based nanoporous charged membranes were prepared in aqueous media and gelated in methanol at 10 degrees C to tailor their pore structure. These membranes were extensively characterized for their physicochemical, electrochemical, and permeation characteristics using FTIR, TGA, DSC, water content, ion-exchange capacity, ionic transport properties, and membrane permeability studies. N-Methylene phosphonic chitosan (NMPC)/PVA-based membranes exhibited mild cation selectivity and quaternized chitosan (QC)/PVA composite membranes had mild anion selectivity, while a blend of NMPC-QC/PVA membranes exhibited weak cation selectivity because of formation of zwitterionic structure. Viscosity measurements and interaction studies for individual and mixed solutions of NMPC and QC were carried out for the prediction of charge interactions between -PO3H2 and -N+(CH3)3 groups and effect on molecular weight due to functionalization. Elaborate electrochemical and permeation experiments were conducted in order to predict suitability of these membranes for the separation of mono- and bivalent electrolytes based on their hydrated ionic radius, and it was found that among all the synthesized membranes, PC/QC-30 had the highest relative permeability, which may extend its suitability for electrolyte separations. Observations were correlated with equivalent pore radius of the different membranes as estimated by membrane permeability measurements.

  7. ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

    DOEpatents

    Long, R.L.

    1958-09-30

    A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

  8. Effect of olive storage conditions on Chemlali olive oil quality and the effective role of fatty acids alkyl esters in checking olive oils authenticity.

    PubMed

    Jabeur, Hazem; Zribi, Akram; Abdelhedi, Ridha; Bouaziz, Mohamed

    2015-02-15

    The present paper accounts for the study of the storage of Chemlali olive fruits at two conditions of limited aerobiosis: in closed plastic bags and in open perforated plastic boxes for different periods before oil extraction. The ultimate objective is to investigate the effect of the container type of the postharvest fruit storage on the deterioration of the olive oil quality. The results have shown that the oil quality of Chemlali olives deteriorated more rapidly during fruit storage in closed plastic bags than in perforated plastic boxes. Therefore, the use of perforated plastic boxes is recommended for keeping the olives for longer periods of storage. The repeated measures analysis of variance of all parameters analyzed indicated that the olive oil quality is mainly affected by the olives storage conditions (containers type and storage periods). Finally, blends of extra-virgin olive oil and mildly deodorized low-quality olive oils can be detected by their alkyl esters concentrations.

  9. Biosynthesis of rhizocticins, antifungal phosphonate oligopeptides produced by Bacillus subtilis ATCC6633

    PubMed Central

    Borisova, Svetlana A.; Circello, Benjamin T.; Zhang, Jun Kai; van der Donk, Wilfred A.; Metcalf, William W.

    2010-01-01

    Summary Rhizocticins are phosphonate oligopeptide antibiotics containing the C-terminal non-proteinogenic amino acid (Z)-l-2-amino-5-phosphono-3-pentenoic acid (APPA). Here we report the identification and characterization of the rhizocticin biosynthetic gene cluster (rhi) in Bacillus subtilis ATCC6633. Rhizocticin B was heterologously produced in the non-producer strain Bacillus subtilis 168. A biosynthetic pathway is proposed based on bioinformatics analysis of the rhi genes. One of the steps during the biosynthesis of APPA is an unusual aldol reaction between phosphonoacetaldehyde and oxaloacetate catalyzed by an aldolase homolog RhiG. Recombinant RhiG was prepared and the product of an in vitro enzymatic conversion was characterized. Access to this intermediate allows for biochemical characterization of subsequent steps in the pathway. PMID:20142038

  10. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721.10679 Section 721... Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester... identified generically as carboxylic acid, substituted alkylstannylene ester, reaction products...

  11. 76 FR 6335 - Sodium and Potassium Salts of N-alkyl (C8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ... AGENCY 40 CFR Part 180 Sodium and Potassium Salts of N-alkyl (C 8 - C 18 )-beta-iminodipropionic acid... residues of sodium and potassium salts of N-alkyl (C 8 -C 18 )-beta-iminodipropionic acid where the C 8 -C.... EPA previously published a final rule to establish a tolerance exemption for sodium salts of SSNA...

  12. Formation of furan fatty alkyl esters from their bis-epoxide fatty esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reactions of epoxidized alkyl soyate with four different alcohols: ethanol, isopropyl alcohol, 2-ethylhexanol, and benzyl alcohol were investigated in the presence of Bronsted acid catalyst. Products not reported in prior studies of similar reactions were found. These were furan fatty acid alkyl est...

  13. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  14. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  15. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  16. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  17. 40 CFR 721.2140 - Carbo-poly-cycli-col azo-alkyl-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. 721.2140 Section 721.2140 Protection of Environment...-aminoalkyl-carbo-mono-cyclic ester, halogen acid salt. (a) Chemical substance and significant new uses...-mino-al-kyl-car-bo-mon-o-cyc-lic ester, halogen acid salt (PMN P-88-1682) is subject to reporting...

  18. Structure of the Escherichia coli Phosphonate Binding Protein PhnD and Rationally Optimized Phosphonate Biosensors

    SciTech Connect

    Alicea, Ismael; Marvin, Jonathan S.; Miklos, Aleksandr E.; Ellington, Andrew D.; Looger, Loren L.; Schreiter, Eric R.

    2012-09-17

    The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate (Pn) uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by {approx}70{sup o} between the two states. Extensive hydrogen bonding and electrostatic interactions stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into Pn uptake by bacteria and facilitated the rational design of high signal-to-noise Pn biosensors based on both coupled small-molecule dyes and autocatalytic fluorescent proteins.

  19. Formation of carboxylic acids from alcohols and olefins in zeolite H-ZSM-5 under mild conditions via trapping of alkyl carbenium ions with carbon monoxide: An in situ {sup 13}C solid state NMR study

    SciTech Connect

    Stepanov, A.G.; Luzgin, M.V.; Romannikov, V.N.; Sidelnikov, V.N.; Zamaraev K.I.

    1996-12-01

    Using in situ {sup 13}C solid state MAS NMR (for some reagents in combination with ex situ GC-MS), it is shown that butyl alcohols and olefins (ethene, isobutene, octene-1) undergo carbonylation to form carboxylic acids (the Koch reaction) with high conversion on zeolite H-ZSM-5 at 296-373 K. The reactions proceed without application of pressurized conditions, just upon coadsorption of CO and alcohols or CO, H{sub 2}O, and olefins on zeolite. The observed Koch reaction under mild conditions provides strong evidence for the formation of alkyl carbenium ions from alcohols and olefins on the zeolites as crucial reaction intermediates. Of the family of carbenium ions, CO reacts selectively with tertiary cations to produce tertiary carboxylic acids, unless the carbonylated molecule is too large for more bulky tertiary moieties to be accommodated and carbonylated in the narrow pores of H-ZSM05. Thus, t-BuOH, i-BuOH, and isobutene produce trimethylacetic acid with high selectivity and conversion, while ethene transforms selectively into 2-methyl-2-ethyl butyric acid. Reaction of octene-1 molecules with CO and H{sub 2}O results in acids of the C{sub 8}H{sub 17}COOH and C{sub 16}H{sub 33}COOH families with predominantly linear hydrocarbon chains. The data obtained may open up new possibilities in using solid acids in organic synthesis as carbonylation catalysts under mild conditions i.e., low temperature and normal atmospheric pressure. 55 refs., 8 figs.

  20. Layered zirconium phosphonate with inorganic–organic hybrid structure: Preparation and its assembly with DNA

    SciTech Connect

    Liu, Li-Min; Lu, Guo-Yuan; Jiang, Li-Ping; Zhu, Jun-Jie

    2014-07-01

    An aminoethoxy-functionalized zirconium phosphonate (Zr(O{sub 3}POCH{sub 2}CH{sub 2}NH{sub 2}){sub 2}·3H{sub 2}O), abbreviated as ZrRP (R=OCH{sub 2}CH{sub 2}NH{sub 2}), with layered structure has been synthesized. This layered compound possesses the characteristic of inorganic–organic hybrid, due to the covalently linked aminoethoxy in the host layer. The anion exchanged property of this zirconium phosphonate is suitable for the direct intercalation of negatively charged DNA, which is different from these reported zirconium phosphates or zirconium phosphonates. As a precursor, this prepared zirconium phosphonate was utilized to fabricate a novel DNA/ZrRP binary hybrid via a delamination-reassembly procedure. The release behavior of DNA from the DNA/ZrRP composite was investigated at different medium pH, because the combination between zirconium phosphonate sheets and DNA was pH-dependent sensitively. Moreover, the helical conformation of DNA was almost retained after the intercalation and release process. These properties of the DNA/ZrRP composite suggested the potential application of layered zirconium phosphonate as a non-viral vector in gene delivery. - Graphical abstract: The intercalation of DNA into zirconium phosphonate and the release of DNA from the interlayer of zirconium phosphonate. - Highlights: ●A layered aminoethoxy-functionalized zirconium phosphonate has been synthesized. ●DNA was intercalated directly into the prepared zirconium phosphonate. ●A novel zirconium phosphonate/DNA binary hybrid was fabricated. ●DNA can be reversibly released from the interlayer of zirconium phosphonate. ●The intercalation/release processes do not induce the denaturalization of DNA.

  1. Synthesis of lesquerella a-hydroxy phosphonates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydroxy fatty acids (HFAs) have found a number of uses in today’s market, with uses ranging from industrial materials to pharmaceuticals. Castor oil, which is obtained from castor seeds, has served as a source of a versatile HFA; its principle component, ricinoleic acid, can be isolated from castor ...

  2. Safety assessment of alkyl benzoates as used in cosmetics.

    PubMed

    'Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2012-01-01

    The functions of alkyl benzoates in cosmetics include fragrance ingredients, skin-conditioning agents--emollient, skin-conditioning agents--miscellaneous, preservatives, solvents, and plasticizers. The Cosmetic Ingredient Review Expert Panel reviewed the relevant animal and human data and noted gaps in the available safety data for some of the alkyl benzoates. Similar structure activity relationships, biologic functions, and cosmetic product usage allowed the available data of many of the alkyl benzoates to be extended to the entire group. Carcinogenicity data were not available, but available data indicated that these alkyl benzoate cosmetic ingredients are not genotoxic. Also benzoic acid and tested component alcohols were not reproductive or developmental toxicants, are not genotoxic in almost all assays, and are not carcinogenic. These ingredients were determined to be safe in the present practices of use and concentration.

  3. Regeneration of a deactivated USY alkylation catalyst using supercritical isobutane

    SciTech Connect

    Daniel M. Ginosar; David N. Ghompson; Kyle C. Burch

    2005-01-01

    Off-line, in-situ alkylation activity recovery from a completely deactivated solid acid catalyst was examined in a continuous-flow reaction system employing supercritical isobutane. A USY zeolite catalyst was initially deactivated during the liquid phase alkylation of butene with isobutane in a single-pass reactor and then varying amounts of alkylation activity were recovered by passing supercritical isobutane over the catalyst bed at different reactivation conditions. Temperature, pressure and regeneration time were found to play important roles in the supercritical isobutane regeneration process when applied to a completely deactivated USY zeolite alkylation catalyst. Manipulation of the variables that influence solvent strength, diffusivity, surface desorption, hydride transfer rates, and coke aging, strongly influence regeneration effectiveness.

  4. Genomics-Enabled Discovery of Phosphonate Natural Products and their Biosynthetic Pathways

    PubMed Central

    Ju, Kou-San; Doroghazi, James R.; Metcalf, William W.

    2014-01-01

    Phosphonate natural products have proven to be a rich source of useful pharmaceutical, agricultural and biotechnology products, whereas study of their biosynthetic pathways has revealed numerous intriguing enzymes that catalyze unprecedented biochemistry. Here we review the history of phosphonate natural product discovery, highlighting technological advances that have played a key role in the recent advances in their discovery. Central to these developments has been the application of genomics, which allowed discovery and development of a global phosphonate metabolic framework to guide research efforts. This framework suggests that the future of phosphonate natural products remains bright, with many new compounds and pathways yet to be discovered. PMID:24271089

  5. Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

    PubMed Central

    2016-01-01

    Summary Multicomponent reactions (MCRs) are one of the most important processes for the preparation of highly functionalized organic compounds in modern synthetic chemistry. As shown in this review, they play an important role in organophosphorus chemistry where phosphorus reagents are used as substrates for the synthesis of a wide range of phosphorylated heterocycles. In this article, an overview about multicomponent reactions used for the synthesis of heterocyclic compounds bearing a phosphonate group on the ring is given. PMID:27559377

  6. Morphology and Proton Transport in Humidified Phosphonated Peptoid Block Copolymers

    PubMed Central

    2016-01-01

    Polymers that conduct protons in the hydrated state are of crucial importance in a wide variety of clean energy applications such as hydrogen fuel cells and artificial photosynthesis. Phosphonated and sulfonated polymers are known to conduct protons at low water content. In this paper, we report on the synthesis phosphonated peptoid diblock copolymers, poly-N-(2-ethyl)hexylglycine-block-poly-N-phosphonomethylglycine (pNeh-b-pNpm), with volume fractions of pNpm (ϕNpm) values ranging from 0.13 to 0.44 and dispersity (Đ) ≤ 1.0003. The morphologies of the dry block copolypeptoids were determined by transmission electron microscopy and in both the dry and hydrated states by synchrotron small-angle X-ray scattering. Dry samples with ϕNpm > 0.13 exhibited a lamellar morphology. Upon hydration, the lowest molecular weight sample transitioned to a hexagonally packed cylinder morphology, while the others maintained their dry morphologies. Water uptake of all of the ordered samples was 8.1 ± 1.1 water molecules per phosphonate group. In spite of this, the proton conductivity of the ordered pNeh-b-pNpm copolymers ranged from 0.002 to 0.008 S/cm. We demonstrate that proton conductivity is maximized in high molecular weight, symmetric pNeh-b-pNpm copolymers. PMID:27134312

  7. Morphology and Proton Transport in Humidified Phosphonated Peptoid Block Copolymers.

    PubMed

    Sun, Jing; Jiang, Xi; Siegmund, Aaron; Connolly, Michael D; Downing, Kenneth H; Balsara, Nitash P; Zuckermann, Ronald N

    2016-04-26

    Polymers that conduct protons in the hydrated state are of crucial importance in a wide variety of clean energy applications such as hydrogen fuel cells and artificial photosynthesis. Phosphonated and sulfonated polymers are known to conduct protons at low water content. In this paper, we report on the synthesis phosphonated peptoid diblock copolymers, poly-N-(2-ethyl)hexylglycine-block-poly-N-phosphonomethylglycine (pNeh-b-pNpm), with volume fractions of pNpm (ϕNpm) values ranging from 0.13 to 0.44 and dispersity (Đ) ≤ 1.0003. The morphologies of the dry block copolypeptoids were determined by transmission electron microscopy and in both the dry and hydrated states by synchrotron small-angle X-ray scattering. Dry samples with ϕNpm > 0.13 exhibited a lamellar morphology. Upon hydration, the lowest molecular weight sample transitioned to a hexagonally packed cylinder morphology, while the others maintained their dry morphologies. Water uptake of all of the ordered samples was 8.1 ± 1.1 water molecules per phosphonate group. In spite of this, the proton conductivity of the ordered pNeh-b-pNpm copolymers ranged from 0.002 to 0.008 S/cm. We demonstrate that proton conductivity is maximized in high molecular weight, symmetric pNeh-b-pNpm copolymers.

  8. Phosphonate Biosynthesis and Catabolism: A Treasure Trove of Unusual Enzymology

    PubMed Central

    Peck, Spencer C.

    2013-01-01

    Natural product biosynthesis has proven a fertile ground for the discovery of novel chemistry. Herein we review the progress made in elucidating the biosynthetic pathways of phosphonate and phosphinate natural products such as the antibacterial compounds dehydrophos and fosfomycin, the herbicidal phosphinothricin-containing peptides, and the antimalarial compound FR-900098. In each case, investigation of the pathway has yielded unusual, and often unprecedented, biochemistry. Likewise, recent investigations have uncovered novel ways to cleave the C-P bond to yield phosphate under phosphorus starvation conditions. These include the discovery of novel oxidative cleavage of the C-P bond catalyzed by PhnY and PhnZ as well as phosphonohydrolases that liberate phosphate from phosphonoacetate. Perhaps the crown jewel of phosphonate catabolism has been the recent resolution of the longstanding problem of the C-P lyase responsible for reductively cleaving the C-P bond of a number of different phosphonates to release phosphate. Taken together, the strides made on both metabolic and catabolic fronts illustrate an array of fascinating biochemistry. PMID:23870698

  9. Specific detection and properties of enzyme hydrolyzing phosphonate ester in serum.

    PubMed

    Han, G Y; Fan, X H; Jin, X B; Wang, D P

    1992-03-01

    An enzyme capable of hydrolyzing 4-methylumbelliferyl phenylphosphonate to 4-methylumbelliferone and phenylphosphonic acid has been detected in human serum. It has a Km value of 1.72 x 10(-4) mol/L, has an optimum pH of 8.8-9.1 in Tris buffer, and shows maximum activity at 60 degrees C (30 min). The enzymic activity can be inhibited by Na3PO4, EDTA, and cysteine. We saw no effect of CuSO4, adenosine, thymidine, NaN3, diethyl p-nitrophenyl phosphate, p-chloromercuribenzoate, isopropyl fluorophosphate, or eserine on the enzymic activity. The enzyme cannot hydrolyze substrates of phosphodiesterase I or alkaline phosphatase. The enzyme is considered a phosphonate esterase.

  10. Synthesis and Use of a Phosphonate-amidine to Generate an Anti-phosphoarginine Specific Antibody

    PubMed Central

    Subramanian, Venkataraman

    2015-01-01

    Protein arginine phosphorylation is a post-translational modification (PTM) that is important for bacterial growth and virulence. Despite its biological relevance, the intrinsic acid lability of phosphoarginine (pArg) have impaired studies of this novel PTM. Herein, we report for the first time the development of phosphonate-amidines and sulfonate-amidines as isosteres of pArg and then use these mimics as haptens to develop the first high affinity sequence independent anti-pArg specific antibody. Employing this anti-pArg antibody, we further showed that arginine phosphorylation is induced in Bacillus subtilis during oxidative stress. Overall, we expect this antibody to see widespread use in analyzing the biological significance of arginine phosphorylation. Additionally, the chemistry reported here will facilitate the generation of pArg mimetics as highly potent inhibitors of the enzymes that catalyze arginine phosphorylation/dephosphorylation. PMID:26458230

  11. Relative binding affinity of carboxylate-, phosphonate-, and bisphosphonate-functionalized gold nanoparticles targeted to damaged bone tissue

    NASA Astrophysics Data System (ADS)

    Ross, Ryan D.; Cole, Lisa E.; Roeder, Ryan K.

    2012-10-01

    Functionalized Au NPs have received considerable recent interest for targeting and labeling cells and tissues. Damaged bone tissue can be targeted by functionalizing Au NPs with molecules exhibiting affinity for calcium. Therefore, the relative binding affinity of Au NPs surface functionalized with either carboxylate ( l-glutamic acid), phosphonate (2-aminoethylphosphonic acid), or bisphosphonate (alendronate) was investigated for targeted labeling of damaged bone tissue in vitro. Targeted labeling of damaged bone tissue was qualitatively verified by visual observation and backscattered electron microscopy, and quantitatively measured by the surface density of Au NPs using field-emission scanning electron microscopy. The surface density of functionalized Au NPs was significantly greater within damaged tissue compared to undamaged tissue for each functional group. Bisphosphonate-functionalized Au NPs exhibited a greater surface density labeling damaged tissue compared to glutamic acid- and phosphonic acid-functionalized Au NPs, which was consistent with the results of previous work comparing the binding affinity of the same functionalized Au NPs to synthetic hydroxyapatite crystals. Targeted labeling was enabled not only by the functional groups but also by the colloidal stability in solution. Functionalized Au NPs were stabilized by the presence of the functional groups, and were shown to remain well dispersed in ionic (phosphate buffered saline) and serum (fetal bovine serum) solutions for up to 1 week. Therefore, the results of this study suggest that bisphosphonate-functionalized Au NPs have potential for targeted delivery to damaged bone tissue in vitro and provide motivation for in vivo investigation.

  12. Precision Morphology in Sulfonic, Phosphonic, Boronic, and Carboxylic Acid Polyolefins

    DTIC Science & Technology

    2013-11-15

    S. Aitken, C. Francisco Buitrago , Jason D. Heffley, Minjae Lee, Harry W. Gibson, Karen I. Winey, Kenneth B. Wagener. Precision Ionomers: Synthesis...Seitz, C. Francisco Buitrago , Karen I. Winey, Kathleen L. Opper, Travis W. Baughman, Kenneth B. Wagener, Todd M. Alam. The impact of zinc

  13. Asymmetric hydrogenation of α,β-unsaturated phosphonates with Rh-BisP* and Rh-MiniPHOS catalysts: Scope and mechanism of the reaction

    PubMed Central

    Gridnev, Ilya D.; Yasutake, Masaya; Imamoto, Tsuneo; Beletskaya, Irina P.

    2004-01-01

    Optically active 1,2-bis(alkylmethylphosphino)ethanes and bis(alkylmethylphosphino)methanes are unique diphosphine ligands combining the simple molecular structure and P-stereogenic asymmetric environment. This work shows that these ligands exhibit excellent enantioselectivity in rhodium-catalyzed asymmetric hydrogenation of α,β-unsaturated phosphonic acid derivatives. The enantioselective hydrogenation mechanism elucidated by NMR study is also described. PMID:15024119

  14. Synergistic interplay of a non-heme iron catalyst and amino acid coligands in H2 O2 activation for asymmetric epoxidation of α-alkyl-substituted styrenes.

    PubMed

    Cussó, Olaf; Ribas, Xavi; Lloret-Fillol, Julio; Costas, Miquel

    2015-02-23

    Highly enantioselective epoxidation of α-substituted styrenes with aqueous H2 O2 is described by using a chiral iron complex as the catalyst and N-protected amino acids (AAs) as coligands. The amino acids synergistically cooperate with the iron center in promoting an efficient activation of H2 O2 to catalyze epoxidation of this challenging class of substrates with good yields and stereoselectivities (up to 97%ee) in short reaction times.

  15. New water soluble phosphonate and polycarboxylate complexants for enhanced f element separations

    SciTech Connect

    Nash, K.L.; Rickert, P.G.; Lessmann, E.P.; Mendoza, M.D.; Feil, J.F.; Sullivan, J.C.

    1994-08-01

    While lipophilic extractant molecules and ion exchange polymeric materials are clearly essential to efficient separation of metal ions by solvent extraction or ion exchange, the most difficult separations often could not be accomplished without the use of water soluble complexants. This report focuses on recent developments in design, synthesis and characterization of phosphonic acid and polycarboxylic acid ligands for enhanced f element separations. Emphasis is on the basic solution chemistry and crystal structures of complexes of the f elements with selected amino-derivatives of methanediphosphonic acid and with tetrahydrofuran-2,3,4,5-tetracarboxylic acid. The former series of compounds exhibit high affinity for lanthanides and actinides in acidic solutions. The latter ligand exhibits an unusual (and very useful) ``anti-selectivity`` for uranyl ion in a solvent extraction process, which permits efficient separation of uranyl from more radioactive components of nuclear wastes. Most of the observed effects can be explained through examination of the structure of the ligand, and comparison of the spectroscopic and thermodynamic parameters for complexation of various metal ions.

  16. Phosphonate removal from discharged circulating cooling water using iron-carbon micro-electrolysis.

    PubMed

    Zhou, Zhen; Qiao, Weimin; Lin, Yangbo; Shen, Xuelian; Hu, Dalong; Zhang, Jianqiao; Jiang, Lu-Man; Wang, Luochun

    2014-01-01

    Phosphonate is a commonly used corrosion and scale inhibitor for a circulating cooling water (CCW) system. Its discharge could cause eutrophication of receiving waters. The iron-carbon (Fe/C) micro-electrolysis technology was used to degrade and remove phosphonate from discharged CCW. The influences of initial pH, Fe/C ratio (FCR) and temperature on phosphonate removal were investigated in a series of batch tests and optimized by response surface methodology. The quadratic model of phosphonate removal was obtained with satisfactory degrees of fitness. The optimum conditions with total phosphorus removal efficiency of 95% were obtained at pH 7.0, FCR of 1.25, and temperature of 45 °C. The phosphonate removal mechanisms were also studied. Phosphonate removal occurred predominantly via two consecutive reactive phases: the degradation of phosphonate complexes (Ca-phosphonate) and the precipitation of Fe/C micro-electrolysis products (PO₄(3-), Ca²⁺ and Fe³⁺).

  17. Anchored [RuCl2(p-cymene)]2 in hybrid zirconium phosphate-phosphonate coated and pillared with double-stranded hydrophobic linear polystyrene as heterogeneous catalyst suitable for aqueous asymmetric transfer hydrogenation.

    PubMed

    Wang, Rui; Wan, Jingwei; Ma, Xuebing; Xu, Xiao; Liu, Liu

    2013-05-14

    A novel type of phosphonate-containing polystyrene copolymers 1a-e bearing an N'-alkylated TsDPEN chiral ligand and double-stranded polystyrene chains were prepared for the first time using simple radical copolymerization of 1-phosphonate styrene with (R,R)-N'-4'-vinylbenzyl-N-4-vinylbenzenesulfonyl-1,2-diphenylethylene-1,2-diamine. Through the coprecipitation of their supported Ru polystyrene copolymers 2a-e and NaH2PO4 with ZrOCl2, pillared hybrid zirconium phosphate-phosphonate-anchored Ru catalysts 3a-e and 4d1-d5 were obtained as heterogeneous catalysts suitable for aqueous asymmetric transfer hydrogenation. In the aqueous asymmetric transfer hydrogenation of aromatic ketones, the anchored Ru catalysts showed good catalytic activities, chemoselectivities (~100%), and enantioselectivities (73.6% ee to 95.6% ee). The Ru catalysts retained their catalytic properties even at the fifth recycle time (92.2% conv., 92.1% ee). However, corresponding supported Ru catalyst 3d' resulted in disappointing reusability because of the loss of ruthenium in every recycle process. The conversions of aromatic ketones were closely related to the o-, m- or p-positions of the substituents on the aromatic ring caused by shape-selective matching.

  18. A new procedure for N1-alkylation of imidazolidin-4-ones and its NMR characterization

    NASA Astrophysics Data System (ADS)

    Vale, Nuno; Figueiredo, Patrícia

    2016-12-01

    N1-unsubstituted imidazolidin-4-ones of primaquine (PQ) can be stabilized by N1-alkylation under basic conditions. Here we report the development, with our conditions, of peptidomimetic derivatives of PQ with L-amino acid and alkyl derivatives. The new derivatives represent potential new therapeutics for use against protozoan parasites, through enzymatic protection of aminopeptidases.

  19. Step by Step Assembly of Polynuclear Lanthanide Complexes with a Phosphonated Bipyridine Ligand.

    PubMed

    Souri, Nabila; Tian, Pingping; Lecointre, Alexandre; Lemaire, Zoé; Chafaa, Salah; Strub, Jean-Marc; Cianférani, Sarah; Elhabiri, Mourad; Platas-Iglesias, Carlos; Charbonnière, Loïc J

    2016-12-19

    The synthesis of the octadentate ligand L (LH8 = ((([2,2'-bipyridine]-6,6'-diylbis(methylene))bis(azanetriyl))tetrakis(methylene))tetrakis(phosphonic acid)) is reported. The coordination of L with various lanthanide cations was monitored by absorption and luminescence spectrophotometric titration experiments (Ln = Tb, Yb), potentiometry (Ln = La, Eu, Lu), and mass spectrometry (Ln = Tb). It was found that L forms very stable mononuclear (LnL) species in aqueous solutions (log K = 19.80(5), 19.5(2), and 19.56(5) for La, Eu, and Lu, respectively) with no particular trend along the series. Spectroscopic data showed the Ln cations to be enclosed in the cavity formed by the octadentate ligand, thereby shielding the metal from interactions with water molecules in the first coordination sphere. When more than one equivalent of cations is added, the formation of polynuclear [(LnL)2Lnx] complexes (x = 1-3) can be observed, the presence of which could be confirmed by electrospray and MALDI mass spectrometry experiments. DFT modeling of the mononuclear (LnL) complexes indicated that the coordination of the cation in the cavity of the ligand results in a very asymmetric charge distribution, with a region of small negative electrostatic potential on the hemisphere composed of the chromophoric bipyridyl moiety and an electron-rich domain at the opposite hemisphere around the four phosphonate functions. DFT further showed that this polarization is most likely at the origin of the strong interactions between the (LnL) complexes and the incoming additional cations, leading to the formation of the polynuclear species. (1)H and (31)P NMR were used to probe the possible exchange of the lanthanide complexed in the cavity of the ligand in D2O, revealing no detectable exchange after 4 weeks at 80 °C and neutral pD, therefore pointing out an excellent kinetic inertness.

  20. Novel alpha-zirconium phosphonates for the reinforcement of ductile thermoplastics

    NASA Astrophysics Data System (ADS)

    Furman, Benjamin R.

    2007-12-01

    Ductile thermoplastics are useful additives for providing fracture toughness to brittle thermosetting polymers; however, this toughening is usually accompanied by a significant decrease in elastic modulus. Therefore, alpha-zirconium phosphonates (ZrP) were developed and investigated as reinforcing nano-scale fillers that increase the yield strength and elastic modulus of a polyester thermoplastic without causing a reduction in its ductility. ZrP materials are synthetic layered compounds that are imbued with targeted organic surface functionalities and whose structural development can be carefully controlled in the laboratory. Ether-terminal alkyl ZrP materials were designed and synthesized, using a conventional ZrF62--mediated preparation, with the intent of developing strong dipole-dipole interactions between the layer surfaces and polyester macromolecules. Additionally, a general method for using lamellar lyotropic liquid crystals (LLC's) as supramolecular templates for alkyl ZrP was evaluated, whose products showed promising similarity to the conventionally prepared materials. The LLC-forming characteristics of several organophosphonate preparations were determined, showing improved mesophase stability with mixed amphiphiles and preparation with R4N + counterions. A mixed-surface octyl/methoxyundecyl ZrP was produced and combined with polycaprolactone (PCL) and polymethylmethacrylate (PMMA) in concentrations up to 50% (w/w). The mechanical properties of the ZrP/PCL nanocomposite were evaluated by tensile, flexural, and dynamic mechanical testing methods. Nanocomposites containing 5% (w/w) ZrP showed significant increases in tensile yield stress and elastic modulus without suffering any loss of ductility versus the unfilled polymer. Layer delamination from the ZrP tactoids was minimal and did not occur through an intercalative mechanism. Higher ZrP loadings resulted in the agglomeration of tactoids, leading to defect structures and loss of strength and ductility

  1. Surface-enhanced Raman scattering studies on the interaction of phosphonate derivatives of imidazole, thiazole, and pyridine with a silver electrode in aqueous solution.

    PubMed

    Podstawka, Edyta; Kudelski, Andrzej; Olszewski, Tomasz K; Boduszek, Bogdan

    2009-07-23

    Surface-enhanced Raman scattering (SERS) spectra from phosphonate derivatives of N-heterocyclic aromatic compounds immobilized on an electrochemically roughened silver electrode surface are reported and compared to Raman spectra of the corresponding solid species. The tested compounds contain imidazole [ImMeP ([hydroxy-(1H-imidazol-5-yl)-methyl]-phosphonic acid) and (ImMe)2P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]-phosphinic acid)]; thiazole [BAThMeP ((butylamino-thiazol-2-yl-methyl)-phosphonic acid) and BzAThMeP ((benzylamino-thiazol-2-yl-methyl)-phosphonic acid)]; and pyridine ((PyMe)2P (bis[(hydroxy-pyridin-3-yl-methyl)]-phosphinic acid) aromatic rings. Changes in wavenumber, broadness, and the enhancement of N-heterocyclic aromatic ring bands upon adsorption are consistent with the adsorption primarily occurring through the N lone pair of electrons with the ring arranged in a largely edge-on manner for ImMeP and BzAThMeP or in a slightly inclined orientation to the silver electrode surface at an intermediate angle from the surface normal for (ImMe)2P, BAThMeP, and (PyMe)2P. A strong enhancement of a roughly 1500 cm(-1) SERS signal for ImMeP and (PyMe)2P is also observed. This phenomenon is attributed to the formation of a localized C=C bond, which is accompanied by a decrease in the ring-surface pi-electrons' overlap. In addition, more intense SERS bands due to the benzene ring in BzAThMeP are observed than those observed for the thiazole ring, which suggests a preferential adsorption of benzene. Some interaction of a phosphonate unit is also suggested but with moderate strength between biomolecules. The strength of the P=O coordination to the silver electrode is highest for ImMeP but lowest for BzAThMeP. For all studied biomolecules, the contribution of the structural components to their ability to interact with their receptors was correlated with the SERS patterns.

  2. Polymethylated DOTA ligands. 1. Synthesis of rigidified ligands and studies on the effects of alkyl substitution on acid-base properties and conformational mobility.

    PubMed

    Ranganathan, Ramachandran S; Pillai, Radhakrishna K; Raju, Natarajan; Fan, Helen; Nguyen, Hanh; Tweedle, Michael F; Desreux, Jean F; Jacques, Vincent

    2002-12-16

    This work describes the synthesis and the conformational properties of new polymethylated macrocyclic ligands of potential interest for magnetic resonance imaging. M4cyclen, (2S,5S,8S,11S)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecane, was obtained by cyclotetramerization of (2S)-1-benzyl-2-methylaziridine followed by catalytic hydrogenation. The ligands M4DOTA, [(2S,5S,8S,11S)-4,7,10-tris-carboxymethyl-2,5,8,11-tetramethyl- 1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, and M4DOTMA, (R)-2-[(2S,5S,8S,11S)-4,7,10-tris-((R)-1-carboxyethyl)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, were prepared by carboxyalkylation of M4cyclen in the presence of Na(2)CO(3). The triacetic ligand M4DO3A, [(2S,5S,8S,11S)-4,7-bis-carboxymethyl-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, was obtained in good yields without traces of M4DOTA if NaHCO(3) was the acid scavenger when adding the carboxylic arms. In the same conditions, cyclen yielded M4DOTA in 82% yield. The difference between the reactivity of cyclen and M4cyclen is assigned to the high basicity of the substituted tetraamine as estimated by NMR titration. The one- and two-dimensional (1)H and (13)C NMR spectra of M4DOTA and M4DOTMA in the H(4)L or H(6)L(2+) forms are interpreted as arising from a slow exchange between two elongated geometries in which the methyl substituents are in one of the two possible equatorial-like positions, either close to or away from the carboxylic arms. The axial-like positions are sterically too crowded and cannot be occupied by the methyl groups. An elongated conformation is also adopted by DOTMA, (R)-2-[4,7,10-tris-((R)-carboxyethyl)-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, in the H(6)L(2+) form. The rigidification of the polymethylated ligands allows a detailed NMR analysis that cannot be carried out on the parent unsubstituted ligand DOTA.

  3. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride

  4. Phosphonate utilization by the globally important marine diazotroph Trichodesmium.

    PubMed

    Dyhrman, S T; Chappell, P D; Haley, S T; Moffett, J W; Orchard, E D; Waterbury, J B; Webb, E A

    2006-01-05

    The factors that control the growth and nitrogen fixation rates of marine diazotrophs such as Trichodesmium have been intensively studied because of the role that these processes have in the global cycling of carbon and nitrogen, and in the sequestration of carbon to the deep sea. Because the phosphate concentrations of many ocean gyres are low, the bioavailability of the larger, chemically heterogeneous pool of dissolved organic phosphorus could markedly influence Trichodesmium physiology. Here we describe the induction, by phosphorus stress, of genes from the Trichodesmium erythraeum IMS101 genome that are predicted to encode proteins associated with the high-affinity transport and hydrolysis of phosphonate compounds by a carbon-phosphorus lyase pathway. We show the importance of these genes through expression analyses with T. erythraeum from the Sargasso Sea. Phosphonates are known to be present in oligotrophic marine systems, but have not previously been considered to be bioavailable to marine diazotrophs. The apparent absence of genes encoding a carbon-phosphorus lyase pathway in the other marine cyanobacterial genomes suggests that, relative to other phytoplankton, Trichodesmium is uniquely adapted for scavenging phosphorus from organic sources. This adaptation may help to explain the prevalence of Trichodesmium in low phosphate, oligotrophic systems.

  5. [Study of the enzymatic hydrolysis of a phosphonic ester using microcalorimetry].

    PubMed

    Labadie, M; Debord, J; Breton, J C

    1979-01-01

    A "Batch" microcalorimeter is used at 30 degrees C for the study of the hydrolysis of 4-nitro-phenylphenylphosphonate with a calf-intestinal phosphonate esterase, in a tris buffer, pH 8. The yield of enzymatic hydrolysis is estimated by spectrophotometric determination of the p--nitrophenol evolved; we have then calculated the apparent molar enthalph of the reaction. (delta Happ = -72,2 kj. mol-1). Phenylphosphonic acid, the second reaction product, is not transphosphonylated on tris. The second acidity of phenylphosphonic acid was studied at 30 degrees C by sodium hydroxide electrotitration (pKa2 = 7,13) and by "Flow" microcalorimetry (delta Hionization = 19,8 kj.mol-1). In the same manner at 30 degrees C, we measured the heat of ionization of p-nitrophenol (delta Hionization = 26,75 kj.mol-1). These findings allow a calculation for the actual heat of hydrolysis of 4-nitro-phenyl-phenylphosphonate (delta Hrho = -29,7 kj.mol-1).

  6. Synthetic resin-bound truncated Candida antarctica lipase B for production of fatty acid alkyl esters by transesterification of corn and soybean oils with ethanol or butanol.

    PubMed

    Hughes, Stephen R; Moser, Bryan R; Robinson, Samantha; Cox, Elby J; Harmsen, Amanda J; Friesen, Jon A; Bischoff, Kenneth M; Jones, Marjorie A; Pinkelman, Rebecca; Bang, Sookie S; Tasaki, Ken; Doll, Kenneth M; Qureshi, Nasib; Liu, Siqing; Saha, Badal C; Jackson, John S; Cotta, Michael A; Rich, Joseph O; Caimi, Paolo

    2012-05-31

    A gene encoding a synthetic truncated Candida antarctica lipase B (CALB) was generated via automated PCR and expressed in Saccharomyces cerevisiae. Western blot analysis detected five truncated CALB variants, suggesting multiple translation starts from the six in-frame ATG codons. The longest open reading frame, which corresponds to amino acids 35-317 of the mature lipase, appeared to be expressed in the greatest amount. The truncated CALB was immobilized on Sepabeads® EC-EP resin and used to produce ethyl and butyl esters from crude corn oil and refined soybean oil. The yield of ethyl esters was 4-fold greater from corn oil than from soybean oil and was 36% and 50% higher, respectively, when compared to a commercially available lipase resin (Novozym 435) using the same substrates. A 5:1 (v/v) ratio of ethanol to corn oil produced 3.7-fold and 8.4-fold greater yields than ratios of 15:1 and 30:1, respectively. With corn oil, butyl ester production was 56% higher than ethyl ester production. Addition of an ionic catalytic resin step prior to the CALB resin increased yields of ethyl esters from corn oil by 53% compared to CALB resin followed by ionic resin. The results suggest resin-bound truncated CALB has potential application in biodiesel production using biocatalysts.

  7. PROCESS OF RECOVERING ZIRCONIUM VALUES FROM HAFNIUM VALUES BY SOLVENT EXTRACTION WITH AN ALKYL PHOSPHATE

    DOEpatents

    Peppard, D.F.

    1960-02-01

    A process of separating hafnium nitrate from zirconium nitrate contained in a nitric acid solution by selectively. extracting the zirconium nitrate with a water-immiscible alkyl phosphate is reported.

  8. Systematic investigation of zinc aminoalkylphosphonates: influence of the alkyl chain lengths on the structure formation.

    PubMed

    Schmidt, Corinna; Stock, Norbert

    2012-03-05

    With the high-throughput (HT) methodology, the bifunctional aminoalkylphosphonic acids (AAPA) linker molecules 2-aminoethyl- (AEPA), 3-aminopropyl- (APPA), and 4-aminobutylphosphonic acid (ABPA) [HO(3)P-C(n)H(2n)-NH(2) (n = 2-4)] and zinc nitrate were used to synthesize new metal phosphonates in order to investigate the influence of the alkyl chain length on the structure formation. The systematic investigations led to one known (ZnO(3)PC(2)H(4)NH(2)) and six new compounds: one using AEPA, three using APPA, and two using ABPA. The crystal structures of five compounds were determined by single crystal X-ray diffraction, using X-ray powder diffraction (XRPD) data as well as structure modeling employing force field methods. For compound 1, Zn(O(3)P-C(2)H(4)-NH(3))(NO(3))(H(2)O) (monoclinic, Cc, a = 4.799(1) Å, b = 29.342(6) Å, c = 5.631(1) Å, β = 91.59(3)°, V = 792.7(3) Å(3), Z = 4), and compound 2, Zn(2)(OH)(O(3)P-C(3)H(6)-NH(3))(NO(3)) (monoclinic, P2/c, a = 12.158(2) Å, b = 5.0315(10) Å, c = 13.952(3) Å, β = 113.23(3)°, V = 784.3(3) Å(3), Z = 2), the structures were determined using single crystal X-ray diffraction data. The crystal structures of [Zn(O(3)P-C(3)H(6)-NH(2))]·H(2)O (3) (monoclinic, P2(1)/c, a = 9.094(2) Å, b = 5.0118(7) Å, c = 16.067(4) Å, β = 90.38(2)°, V = 732.3(2) Å(3), Z = 4) and Zn(O(3)P-C(4)H(8)-NH(2)) (5) (monoclinic, P2(1)/c, a = 8.570(7) Å, b = 8.378(4) Å, c = 9.902(6) Å, β = 90.94(5)°, V = 710.9(8) Å(3), Z = 4) were determined using XRPD data. The structural model for compound 6, Zn(O(3)P-C(4)H(8)-NH(3))(NO(3))(H(2)O), was established using lattice parameters from XRPD data and following crystal structure modeling employing force field methods. The structures depend strongly on the alkyl chain length n. For n = 2 and 4 isoreticular compounds are observed, while n = 3 leads to new structures. Larger amounts of all compounds were obtained employing scale-up syntheses in a conventional oven as well as in a microwave

  9. Probing the interaction of U(VI) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy

    DOE PAGES

    Uribe, Eva C.; Mason, Harris E.; Shusterman, Jennifer A.; ...

    2016-05-30

    The fundamental interaction of U(VI) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(VI) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength. Single-pulse 31P NMR on U(VI) contacted samples revealed that U(VI)only interacts with a fraction of the ligands present on the surface. At pH 4 the U(VI) extraction capacity of the material is limited to 27–37% of the theoretical capacity, based on ligand loading. We combined single pulse 31P NMR on U(VI)-contacted samples withmore » batch studies to measure a ligand-to-metal ratio of approximately 2 : 1 at pH 3 and 4. Batch studies and cross-polarization NMR measurements reveal that U(VI) binds to deprotonated phosphonate and/or silanol sites. We use 31P–31P DQ-DRENAR NMR studies to compare the average dipolar coupling between phosphorus spins for both U(VI)-complexed and non-complexed ligand environments. Furthermore, these measurements reveal that U(VI) extraction is not limited by inadequate surface distribution of ligands, but rather by low stability of the surface phosphonate complex.« less

  10. Probing the interaction of U(vi) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy.

    PubMed

    Uribe, Eva C; Mason, Harris E; Shusterman, Jennifer A; Bruchet, Anthony; Nitsche, Heino

    2016-06-21

    The fundamental interaction of U(vi) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(vi) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength. Single-pulse (31)P NMR on U(vi) contacted samples revealed that U(vi) only interacts with a fraction of the ligands present on the surface. At pH 4 the U(vi) extraction capacity of the material is limited to 27-37% of the theoretical capacity, based on ligand loading. We combined single pulse (31)P NMR on U(vi)-contacted samples with batch studies to measure a ligand-to-metal ratio of approximately 2 : 1 at pH 3 and 4. Batch studies and cross-polarization NMR measurements reveal that U(vi) binds to deprotonated phosphonate and/or silanol sites. We use (31)P-(31)P DQ-DRENAR NMR studies to compare the average dipolar coupling between phosphorus spins for both U(vi)-complexed and non-complexed ligand environments. These measurements reveal that U(vi) extraction is not limited by inadequate surface distribution of ligands, but rather by low stability of the surface phosphonate complex.

  11. In situ EPR studies of reaction pathways in Titania photocatalyst-promoted alkylation of alkenes.

    PubMed

    Rhydderch, Shona; Howe, Russell F

    2015-03-03

    In situ EPR spectroscopy at cryogenic temperatures has been used to observe and identify paramagnetic species produced when titania is irradiated in the presence of reactants used in the photocatalytic alkylation of maleimide with t-butyl carboxylic acid or phenoxyacetic acid. It is shown that maleimide acts as an acceptor of conduction band electrons. Valence band holes oxidise t-butyl carboxylic acid to the t-butyl radical and phenoxyacetic acid to the phenoxyacetic acid radical cation. In the presence of maleimide, the phenoxymethyl radical is formed from phenoxyacetic acid. The relevance of these observations to the mechanisms of titania photocatalyst-promoted alkylation of alkenes is discussed.

  12. Materials performance in HF-alkylation units

    SciTech Connect

    Forsen, O.; Aromaa, J.; Somervuori, M.; Tavi, M.

    1995-11-01

    Materials selection in HF-alkylation units is mostly based on long time experience. The most widely used material in the Station units is standard carbon steel, because it is capable to form a thick protective FeF{sub 2} layer in concentrated or anhydrous hydrofluoric acid. The corrosion resistance decreases, when the acid is dilute (less than 64% HF) or the temperature is above 160F (70 C). The composition and metallurgical state are also suspected to affect the corrosion resistance of carbon steel. The effect of composition appears more complicated than believed, especially the A-106 specification on the total amount of Cr+Ni+Cu+Mo+V < 1% should be studied more closely from the corrosion point of view. Laboratory tests showed that the uniform corrosion rate may be 100 times higher in galvanic contact of two dissimilar steels. The effect of galvanic contacts can neither be excluded in the process equipment corrosion cases.

  13. Total synthesis of alkyl citrate natural products.

    PubMed

    Rizzacasa, Mark A; Sturgess, Dayna

    2014-03-07

    This review highlights the synthesis of members of the alkyl citrate family of natural products. The focus is on the stereoselective construction of the alkyl citrate moiety common to these compounds.

  14. Two di­alkyl­ammonium salts of 2-amino-4-nitro­benzoic acid: crystal structures and Hirshfeld surface analysis

    PubMed Central

    Wardell, James L.; Jotani, Mukesh M.; Tiekink, Edward R. T.

    2016-01-01

    The crystal structures of two ammonium salts of 2-amino-4-nitro­benzoic acid are described, namely di­methyl­aza­nium 2-amino-4-nitro­benzoate, C2H8N+·C7H5N2O4 −, (I), and di­butyl­aza­nium 2-amino-4-nitro­benzoate, C8H20N+·C7H5N2O4 −, (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl­ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti­periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl­ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra­molecular amino-N—H⋯O(carboxyl­ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra­molecular chain by charge-assisted amine-N—H⋯O(carboxyl­ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N—H⋯O(carboxyl­ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N—O⋯π(arene) and methyl-C—H⋯O(nitro) inter­actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N—H⋯O(carboxyl­ate) hydrogen bonding. The formation of ammonium

  15. Alkylating potential of styrene oxide: reactions and factors involved in the alkylation process.

    PubMed

    González-Pérez, Marina; Gómez-Bombarelli, Rafael; Pérez-Prior, M Teresa; Arenas-Valgañón, Jorge; García-Santos, M Pilar; Calle, Emilio; Casado, Julio

    2014-10-20

    The chemical reactivity of styrene-7,8-oxide (SO), an alkylating agent with high affinity for the guanine–N7 position and a probable carcinogen for humans, with 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilic characteristics similar to those of DNA bases, was investigated kinetically in water/dioxane media. UV–vis spectrophotometry and ultrafast liquid chromatography were used to monitor the reactions involved. It was found that in the alkylation process four reactions occur simultaneously: (a) the formation of a β-NBP–SO adduct through an SN2 mechanism; (b) the acid-catalyzed formation of the stable α-NBP–SO adduct through an SN2′ mechanism; (c) the base-catalyzed hydrolysis of the β-adduct, and (d) the acid-catalyzed hydrolysis of SO. At 37.5 °C and pH = 7.0 (in 7:3 water/dioxane medium), the values of the respective reaction rate constants were as follows: kalkβ = (2.1 ± 0.3) × 10–4 M–1 s–1, kalkα = (1.0 ± 0.1) × 10–4 M–1 s–1, khydAD = (3.06 ± 0.09) × 10–6 s–1, and khyd = (4.2 ± 0.9) × 10–6 s–1. These values show that, in order to determine the alkylating potential of SO, none of the four reactions involved can be neglected. Temperature and pH were found to exert a strong influence on the values of some parameters that may be useful to investigate possible chemicobiological correlations (e.g., in the pH 5.81–7.69 range, the fraction of total adducts formed increased from 24% to 90% of the initial SO, whereas the adduct lifetime of the unstable β-adduct, which gives an idea of the permanence of the adduct over time, decreased from 32358 to 13313 min). A consequence of these results is that the conclusions drawn in studies addressing alkylation reactions at temperatures and/or pH far from those of biological conditions should be considered with some reserve.

  16. Efficient asymmetric synthesis of novel gastrin receptor antagonist AG-041R via highly stereoselective alkylation of oxindole enolates.

    PubMed

    Emura, Takashi; Esaki, Toru; Tachibana, Kazutaka; Shimizu, Makoto

    2006-10-27

    An efficient method for asymmetric synthesis of the potent Gastrin/CCK-B receptor antagonist AG-041R was developed. Core oxindole stereochemistry was established by asymmetric alkylation of oxindole enolates with bromoacetic acid esters, using l-menthol as a chiral auxiliary. The key alkylation reaction of the oxindole enolates generated tetrasubstituted chiral intermediates with high diastereoselectivity. The stereoselective alkylation reactions are described in detail.

  17. Chichibabin-type direct alkylation of pyridyl alcohols with alkyl lithium reagents.

    PubMed

    Jeffrey, Jenna L; Sarpong, Richmond

    2012-11-02

    Direct C(6) alkylation of pyridyl alcohols can be achieved following an initial deprotonation of the hydroxy group. This transformation, which is believed to occur by a Chichibabin-type alkylation, avoids lateral deprotonation prior to pyridine ring alkylation and gives increased regioselectivity for C(6) over C(4) alkylation.

  18. Refiners discuss HF alkylation process and issues

    SciTech Connect

    Not Available

    1992-04-06

    Safety and oxygenate operations made HF alkylation a hot topic of discussion at the most recent National Petroleum Refiners Association annual question and answer session on refining and petrochemical technology. This paper provides answers to a variety of questions regarding the mechanical, process, and safety aspects of the HF alkylation process. Among the issues discussed were mitigation techniques, removal of oxygenates from alkylation unit feed, and amylene alkylation.

  19. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  20. Radioiodination of Aryl-Alkyl Cyclic Sulfates

    PubMed Central

    Mushti, Chandra; Papisov, Mikhail I.

    2015-01-01

    Among the currently available positron emitters suitable for Positron Emission Tomography (PET), 124I has the longest physical half-life (4.2 days). The long half-life and well-investigated behavior of iodine in vivo makes 124I very attractive for pharmacological studies. In this communication, we describe a simple yet effective method for the synthesis of novel 124I labeled compounds intended for PET imaging of arylsulfatase activity in vivo. Arylsulfatases have important biological functions, and genetic deficiencies of such functions require pharmacological replacement, the efficacy of which must be properly and non-invasively evaluated. These enzymes, even though their natural substrates are mostly of aliphatic nature, hydrolyze phenolic sulfates to phenol and sulfuric acid. The availability of [124I]iodinated substrates is expected to provide a PET-based method for measuring their activity in vivo. The currently available methods of synthesis of iodinated arylsulfates usually require either introducing of a protected sulfate ester early in the synthesis or introduction of sulfate group at the end of synthesis in a separate step. The described method gives the desired product in one step from an aryl-alkyl cyclic sulfate. When treated with iodide, the source cyclic sulfate opens with substitution of iodide at the alkyl center and gives the desired arylsulfate monoester. PMID:23135631

  1. Microbial degradation of n-alkyl tetrahydrothiophenes found in petroleum.

    PubMed Central

    Fedorak, P M; Payzant, J D; Montgomery, D S; Westlake, D W

    1988-01-01

    Although n-alkyl-substituted tetrahydrothiophenes are found in nonbiodegraded petroleums, they are not found in petroleums which have undergone biodegradation in their reservoirs. These observations suggested that this group of compounds with alkyl chain lengths from approximately C10 to at least C30 is biodegradable. Two of these sulfides, 2-n-dodecyltetrahydrothiophene (DTHT) and 2-n-undecyltetrahydrothiophene, were synthesized, and their biodegradabilities were tested by using five gram-positive, n-alkane-degrading bacterial isolates. The alkyl side chains of these compounds were oxidized, and the major intermediates found in 2-n-undecyltetrahydrothiophene- and DTHT-metabolizing cultures were 2-tetrahydrothiophenecarboxylic acid (THTC) and 2-tetrahydrothiopheneacetic acid (THTA), respectively. Four n-alkane-degrading fungi were also shown to degrade DTHT, yielding both THTA and THTC. Quantitation of tetrahydrothiophene ring-containing products in 28-day-old bacterial and fungal cultures suggested that THTC and THTA were metabolized further to unidentified products. In addition, two of the bacterial isolates were shown to degrade a mixture of n-alkyl tetrahydrothiophenes isolated from Bellshill Lake crude oil. PMID:3389816

  2. A Novel Multi-Phosphonate Surface Treatment of Titanium Dental Implants: A Study in Sheep

    PubMed Central

    von Salis-Soglio, Marcella; Stübinger, Stefan; Sidler, Michéle; Klein, Karina; Ferguson, Stephen J.; Kämpf, Käthi; Zlinszky, Katalin; Buchini, Sabrina; Curno, Richard; Péchy, Péter; Aronsson, Bjorn-Owe; von Rechenberg, Brigitte

    2014-01-01

    The aim of the present study was to evaluate a new multi-phosphonate surface treatment (SurfLink®) in an unloaded sheep model. Treated implants were compared to control implants in terms of bone to implant contact (BIC), bone formation, and biomechanical stability. The study used two types of implants (rough or machined surface finish) each with either the multi-phosphonate Wet or Dry treatment or no treatment (control) for a total of six groups. Animals were sacrificed after 2, 8, and 52 weeks. No adverse events were observed at any time point. At two weeks, removal torque showed significantly higher values for the multi-phosphonate treated rough surface (+32% and +29%, Dry and Wet, respectively) compared to rough control. At 52 weeks, a significantly higher removal torque was observed for the multi-phosphonate treated machined surfaces (+37% and 23%, Dry and Wet, respectively). The multi-phosphonate treated groups showed a positive tendency for higher BIC with time and increased new-old bone ratio at eight weeks. SEM images revealed greater amounts of organic materials on the multi-phosphonate treated compared to control implants, with the bone fracture (from the torque test) appearing within the bone rather than at the bone to implant interface as it occurred for control implants. PMID:25215424

  3. Determination of Selected Perfluorinated Alkyl Acids in ...

    EPA Pesticide Factsheets

    The 1996 amendments to the Safe Drinking Water Act (SDWA) required EPA to establish a Contaminant Candidate List (CCL), that contains a list of drinking water contaminants that the Agency will consider for future regulation. EPA must make a regulatory determination on a minimum of five contaminants every five years. The first CCL was published in 1998, and updates were anticipated every five years thereafter. One of the key pieces of information that must be available in order to make a regulatory determination is nationwide occurrence data for the chemical contaminants under consideration. Historically, EPA has collected the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMR). Under the UCMR, monitoring is conducted at selected drinking water utilities for specific contaminants of interest. The chemical analyses are usually performed by the utilities or by commercial laboratories. To meet the requirements of monitoring under the UCMR program, the analytical methods developed should be specific, sensitive, and practical enough for application in commercial laboratories. This task will focus on the development of analytical methods for chemicals identified on future CCLs or emerging contaminants not yet listed on the CCL. These methods will be used for the collection of occurrence data under future UCMRs. The objective of this research effort is to develop analytical methods to be used to measure the occurrence of

  4. Probing the influence of phosphonate bonding modes to uranium(VI) on structural topology and stability: a complementary experimental and computational investigation.

    PubMed

    Zheng, Tao; Wu, Qun-Yan; Gao, Yang; Gui, Daxiang; Qiu, Shiwen; Chen, Lanhua; Sheng, Daopeng; Diwu, Juan; Shi, Wei-Qun; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2015-04-20

    Systematic control of the reactions between U(VI) and 1,4-phenylenebis(methylene))bis(phosphonic acid) (pmbH4) allows for alterations in the bonding between these constituents and affords three uranyl phosphonate compounds with chiral one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) structures, namely, [TPA][UO2(pmbH3)(pmbH2)H2O]·2H2O (1), [NH4]2[UO2(pmb)] (2), UO2(pmbH2) (3), and the first uranyl mixed phosphite/phosphonate compound [TMA]2[(UO2)2(pmb)(HPO3)] (4) (TPA = NPr4+, TMA = NMe4+). These compounds crystallize in the space groups P212121, P1̅, P21/c, and Cmcm, respectively. Further investigation of the local uranyl coordination environment reveals that in 1 only oxygen atoms from P=O moieties ligate the uranium centers; whereas in 2 only P-O(-) oxygen atoms are involved in bonding and yield a layered topology. Compound 3 differs sharply from the first two in that conjugated P=O and P-O(-) oxygen atoms chelate the uranium centers resulting in a 3D framework. In compound 4, a phosphonate group bridges three uranyl centers further coordinated with a phosphite ligand HPO32–, which is a product of pmbH4 decomposing, forming a 2D layered structure. Compounds 3 and 4 also contain a different coordination environment for U(VI) than that found in 1 or 2. In this case, tetragonal bipyramidal UO6 units occur instead of the far more common UO7 pentagonal bipyramids found in 1 and 2. Interestingly, 1 converts to 3 at elevated reaction temperatures, indicating that the formation of 1 is likely under kinetic control. This is supported by thermal analysis, which reveals that 3 has higher thermal stability than 1 or 2. UV-vis-near-IR absorption and fluorescence spectroscopy show that the absorption and photoluminescence intensity increases from 1 to 4. Density functional theory electronic structure calculations provide insight into the nature of the interactions between U(VI) and the phosphonate ligands.

  5. Rhodium carbene routes to oxazoles and thiazoles. Catalyst effects in the synthesis of oxazole and thiazole carboxylates, phosphonates, and sulfones.

    PubMed

    Shi, Baolu; Blake, Alexander J; Lewis, William; Campbell, Ian B; Judkins, Brian D; Moody, Christopher J

    2010-01-01

    Dirhodium tetraacetate catalyzed reaction of alpha-diazo-beta-keto-carboxylates and -phosphonates with arenecarboxamides gives 2-aryloxazole-4-carboxylates and 4-phosphonates by carbene N-H insertion and cyclodehydration. In stark contrast, dirhodium tetrakis(heptafluorobutyramide) catalysis results in a dramatic change of regioselectivity to give oxazole-5-carboxylates and 5-phosphonates. Alpha-diazo-beta-ketosulfones behave similarly and give 5-sulfonyloxazoles upon dirhodium tetrakis(heptafluorobutyramide) catalyzed reaction with carboxamides. The analogous reactions of thiocarboxamides give the corresponding thiazole-5-carboxylates, -phosphonates, and -sulfones.

  6. Bifunctional alkylating agent-induced p53 and nonclassical nuclear factor kappaB responses and cell death are altered by caffeic acid phenethyl ester: a potential role for antioxidant/electrophilic response-element signaling.

    PubMed

    Minsavage, Gary D; Dillman, James F

    2007-04-01

    Bifunctional alkylating agents (BFA) such as mechlorethamine (nitrogen mustard) and bis-(2-chloroethyl) sulfide (sulfur mustard; SM) covalently modify DNA and protein. The roles of nuclear factor kappaB (NF-kappaB) and p53, transcription factors involved in inflammatory and cell death signaling, were examined in normal human epidermal keratinocytes (NHEK) and immortalized HaCaT keratinocytes, a p53-mutated cell line, to delineate molecular mechanisms of action of BFA. NHEK and HaCaT cells exhibited classical NF-kappaB signaling as degradation of inhibitor protein of NF-kappaBalpha (IkappaBalpha) occurred within 5 min after exposure to tumor necrosis factor-alpha. However, exposure to BFA induced nonclassical NF-kappaB signaling as loss of IkappaBalpha was not observed until 2 or 6 h in NHEK or HaCaT cells, respectively. Exposure of an NF-kappaB reporter gene-expressing HaCaT cell line to 12.5, 50, or 100 muM SM activated the reporter gene within 9 h. Pretreatment with caffeic acid phenethyl ester (CAPE), a known inhibitor of NF-kappaB signaling, significantly decreased BFA-induced reporter gene activity. A 1.5-h pretreatment or 30-min postexposure treatment with CAPE prevented BFA-induced loss of membrane integrity by 24 h in HaCaT cells but not in NHEK. CAPE disrupted BFA-induced phosphorylation of p53 and p90 ribosomal S6 kinase (p90RSK) in both cell lines. CAPE also increased nuclear factor E2-related factor 2 and decreased aryl hydrocarbon receptor protein expression, both of which are involved in antioxidant/electrophilic response element (ARE/EpRE) signaling. Thus, disruption of p53/p90RSK-mediated NF-kappaB signaling and activation of ARE/EpRE pathways may be effective strategies to delineate mechanisms of action of BFA-induced inflammation and cell death signaling in immortalized versus normal skin systems.

  7. Adsorption of phosphonate antiscalant from reverse osmosis membrane concentrate onto granular ferric hydroxide.

    PubMed

    Boels, Luciaan; Keesman, Karel J; Witkamp, Geert-Jan

    2012-09-04

    Adsorptive removal of antiscalants offers a promising way to improve current reverse osmosis (RO) concentrate treatment processes and enables the reuse of the antiscalant in the RO desalination process. This work investigates the adsorption and desorption of the phosphonate antiscalant nitrilotris(methylenephosphonic acid) (NTMP) from RO membrane concentrate onto granular ferric hydroxide (GFH), a material that consists predominantly of akaganéite. The kinetics of the adsorption of NTMP onto GFH was predicted fairly well with two models that consider either combined film-pore or combined film-surface diffusion as the main mechanism for mass transport. It is also demonstrated that NTMP is preferentially adsorbed over sulfate by GFH at pH 7.85. The presence of calcium causes a transformation in the equilibrium adsorption isotherm from a Langmuir type to a Freundlich type with much higher adsorption capacities. Furthermore, calcium also increases the rate of adsorption substantially. GFH is reusable after regeneration with sodium hydroxide solution, indicating that NTMP can be potentially recovered from the RO concentrate. This work shows that GFH is a promising adsorbent for the removal and recovery of NTMP antiscalant from RO membrane concentrates.

  8. Rapid Synthesis and Antiviral Activity of (Quinazolin-4-Ylamino)Methyl-Phosphonates Through Microwave Irradiation

    PubMed Central

    Luo, Hui; Hu, Deyu; Wu, Jian; He, Ming; Jin, Linhong; Yang, Song; Song, Baoan

    2012-01-01

    This study describes the simple synthesis of new (quinazolin-4-ylamino) methylphosphonates via microwave irradiation. Substituted-2-aminobenzonitrile reacted with 1,1-dimethoxy-N,N-dimethylmethanamine at a reflux condition to obtain N′-(substituted-2-cyanophenyl)-N,N-dimethylformamidine (1). The subsequent reaction of this intermediate product with α-aminophosphonate (2) in a solution containing glacial acetic acid in 2-propanol through microwave irradiation resulted in the formation of (quinazolin-4-ylamino)methyl-phosphonate derivatives 3a to 3x, which were unequivocally characterized by the spectral data and elemental analysis. The influence of the reaction conditions on the yield of 3a was investigated to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 3a include a 1:1 molar ratio of N′-(2-cyanophenyl)-N,N-dimethylformamidine to diethyl amino(phenyl)methylphosphonate and a 4:1 volume ratio of isopropanol to HOAc in the solvent mixture, at a reaction temperature of 150 °C, with a microwave power of 100 W and a corresponding pressure of 150 psi for 20 min in the microwave synthesizer. The yield of 3a was approximately 79%, whereas those of 3b to 3x were approximately 77% to 86%. Some of the synthesized compounds displayed weak to good anti-Tobacco mosaic virus (TMV) activity. PMID:22837660

  9. Diastereoselectivity in the Mukaiyama-Michael Reaction Employing alpha-Acyl beta,gamma-Unsaturated Phosphonates.

    PubMed

    Telan, Leila A.; Poon, Chi-Duen; Evans, Slayton A.

    1996-10-18

    The unique electronic and structural nature of the alpha-acylphosphonate functional group affords both dimeric and chelated complexes of diethyl crotonyl phosphonate (1; DECP) with stannic chloride (SnCl(4)). The dimeric complex, SnCl(4).(DECP)(2) (5) results from the coordination of two DECP molecules, ligated via the phosphoryl oxygens to the tin atom. The chelated complex, SnCl(4).(DECP) (6), is best represented with both phosphoryl and carbonyl oxygens coordinated to the metal center. Both metal ligated and chelated complexes have unique (13)C (31)P, and (119)Sn NMR spectra. In complex 5, the (13)C NMR resonances attributed to the carbonyl carbons were shifted upfield of free DECP. A monocoordinating Lewis acid, BF(3).OEt(2), produced a similar chemical shift trend in both the (13)C and (31)P NMR spectra of the BF(3).DECP complex. Essentially quantitative yields and moderate diastereomeric excesses favoring anti (or trans) diethyl 6-phenyl-4,5-dimethyl-6-(trimethylsilyloxy)-2-dihydropyranphosphonate (3) and diethyl 5-phenyl-3,4-dimethyl-1,5-dioxopentanephosphonate (4) were obtained from both chelated and dimeric SnCl(4).(DECP)(n) (n = 1, 2) when treated with either diastereomeric (Z)- or (E)-1-phenyl-1-(trimethylsilyloxy)-1-propene 2. Diethyl crotonylphosphonate (1), 3, and 4 were fully characterized.

  10. Highly Ordered Mesostructured Vanadium Phosphonate toward Electrode Materials for Lithium-Ion Batteries.

    PubMed

    Mei, Peng; Pramanik, Malay; Lee, Jaewoo; Ide, Yusuke; Alothman, Zeid Abdullah; Kim, Jung Ho; Yamauchi, Yusuke

    2017-03-28

    Highly ordered mesostructured vanadium phosphonates (VP) have been synthesized in the presence of cetyltrimethylammonium bromide (CTAB) as a structure-directing agent. Nitrilotris(methylene)triphosphonic acid (NMPA) and (ammonium/sodium) metavanadate (NH4 VO3 /NaVO3 ) have been used for the construction of pore walls. The CTAB templates are removed from the materials by an extraction process without destroying the parent mesostructure. The formation mechanism for the ordered mesoporous structure and its impact on electrochemical application in lithium ion batteries (LIBs) are explained by considering the structural and electrochemical stability of the framework. The results demonstrate that the counter cations (NH4(+) /Na(+) ) of the metavanadate precursors have a crucial role in stabilizing the mesoporous structure of the mesoporous VP materials. Mesoporous VP materials with highly ordered structure have great applicability as high-performance electrode materials in LIBs due to the advantages of their large contact area with electrolyte and short transport paths for lithium ions. Mesoporous VP electrodes exhibit high reversible specific capacity with superb cycling stability (100 cycles) and excellent retention of capacity (92 %).

  11. Versatile (bio)functionalization of bromo-terminated phosphonate-modified porous aluminum oxide.

    PubMed

    Debrassi, Aline; Roeven, Esther; Thijssen, Selina; Scheres, Luc; de Vos, Willem M; Wennekes, Tom; Zuilhof, Han

    2015-05-26

    Porous aluminum oxide (PAO) is a nanoporous material used for various (bio)technological applications, and tailoring its surface properties via covalent modification is a way to expand and refine its application. Specific and complex chemical modification of the PAO surface requires a stepwise approach in which a secondary reaction on a stable initial modification is necessary to achieve the desired terminal molecular architecture and reactivity. We here show that the straightforward initial modification of the bare PAO surface with bromo-terminated phosphonic acid allows for the subsequent preparation of PAO with a wide scope of terminal reactive groups, making it suitable for (bio)functionalization. Starting from the initial bromo-terminated PAO, we prepared PAO surfaces presenting various terminal functional groups, such as azide, alkyne, alkene, thiol, isothiocyanate, and N-hydroxysuccinimide (NHS). We also show that this wide scope of easily accessible tailored reactive PAO surfaces can be used for subsequent modification with (bio)molecules, including carbohydrate derivatives and fluorescently labeled proteins.

  12. Structural basis of allosteric and synergistic activation of AMPK by furan-2-phosphonic derivative C2 binding

    PubMed Central

    Langendorf, Christopher G.; Ngoei, Kevin R. W.; Scott, John W.; Ling, Naomi X. Y.; Issa, Sam M. A.; Gorman, Michael A.; Parker, Michael W.; Sakamoto, Kei; Oakhill, Jonathan S.; Kemp, Bruce E.

    2016-01-01

    The metabolic stress-sensing enzyme AMP-activated protein kinase (AMPK) is responsible for regulating metabolism in response to energy supply and demand. Drugs that activate AMPK may be useful in the treatment of metabolic diseases including type 2 diabetes. We have determined the crystal structure of AMPK in complex with its activator 5-(5-hydroxyl-isoxazol-3-yl)-furan-2-phosphonic acid (C2), revealing two C2-binding sites in the γ-subunit distinct from nucleotide sites. C2 acts synergistically with the drug A769662 to activate AMPK α1-containing complexes independent of upstream kinases. Our results show that dual drug therapies could be effective AMPK-targeting strategies to treat metabolic diseases. PMID:26952388

  13. A Novel Side-Bridged Hybrid Phosphonate/Acetate Pendant Cyclam: Synthesis, Characterization, and 64Cu Small Animal PET Imaging

    PubMed Central

    Boswell, C. Andrew; Regino, Celeste A. S.; Baidoo, Kwamena E.; Wong, Karen J.; Milenic, Diane E.; Kelley, James A.; Lai, Christopher C.; Brechbiel, Martin W.

    2008-01-01

    Copper-64 (t½ = 12.7 hr; β+: 0.653 MeV, 17.4%; β−: 0.578 MeV, 39%) is produced in a biomedical cyclotron and has applications in both imaging and therapy. Macrocyclic chelators are widely used as bifunctional chelators to bind copper radionuclides to antibodies and peptides owing to their relatively high kinetic stability. A novel side-bridged cyclam featuring both pendant acetate and phosphonate groups was synthesized using a Kabachnik-Fields approach followed by hydrobromic acid deprotection. The Cu(II) complex of the novel ligand was synthesized, radiolabeling with 64Cu was demonstrated, and in vitro (serum) stability was performed. In addition, in vivo distribution and clearance of the 64Cu-labeled complex was visualized by positron emission tomography (PET) imaging. This novel chelate may be useful in 64Cu-mediated diagnostic positron emission tomography (PET) imaging as well as targeted radiotherapeutic applications. PMID:19101152

  14. Construction of Uranyl Organic Hybrids by Phosphonate and in Situ Generated Carboxyphosphonate Ligands.

    PubMed

    Liu, Chao; Yang, Weiting; Qu, Ning; Li, Lei-Jiao; Pan, Qing-Jiang; Sun, Zhong-Ming

    2017-02-06

    The hydrothermal reaction of uranyl ions with (5-methyl-1,3-phenylene)diphosphonic acid (H4MPDP) in the presence of additives such as nitric acid, N-bearing species, and heterometal ions yielded five new uranyl organic hybrids: (H3O)[(UO2)5(H2O)4(H3DPB)2(H2DPB)(HDPB)]·2H2O (1), (Hphen)(phen)[(UO2)3(H2DPB)(HDPB)] (2), (H2dipy)[(UO2)3(MPDP)2] (3), Zn(bipy)(UO2)(MPDP) (4), and Co(bipy)(UO2)(MPDP)·H2O (5) (H5DPB = 3,5-diphosphonobenzoic acid; phen = 1,10-phenanthroline; dipy = 4,4'-bipyridine; bipy = 2,2'-bipyridine). Single-crystal X-ray diffraction (XRD) demonstrates that 1 and 2 are 3D frameworks constructed of uranyl centers and carboxyphosphonate DPB ligands; the latter were formed via the in situ oxidation of H4MPDP. In the homometallic uranyl diphosphonate 3, less common UO6 square bipyramids connected by MPDP ligands were incorporated to form the 2D assembly. A further introduction of heterometal ions produced two heterobimetallic uranyl phosphonates 4 and 5. Both of them show layered structures, formed by UO6 square bipyramids linked by MPDP ligands with heterometal-centered polyhedra decorated on the sides of the layers. It is found that the pH and heterometal ions have significant effects on the structures of the complexes. In addition to the syntheses and XRD characterization, the spectroscopic properties of these uranyl complexes were also addressed. To complement the experimental results, density functional theory calculations were carried out on several model complexes that feature a homo- or heterobimetallic molecular skeleton. Geometrical/electronic structures, IR spectra, and electronic absorptions were discussed.

  15. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, B.F.; Robison, T.W.; Gohdes, J.W.

    1999-04-06

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  16. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    2002-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  17. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    1999-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  18. Phosphonate-anchored monolayers for antibody binding to magnetic nanoparticles.

    PubMed

    Benbenishty-Shamir, Helly; Gilert, Roni; Gotman, Irena; Gutmanas, Elazar Y; Sukenik, Chaim N

    2011-10-04

    Targeted delivery of magnetic iron oxide nanoparticles (IONPs) to a specific tissue can be achieved by conjugation with particular biological ligands on an appropriately functionalized IONP surface. To take best advantage of the unique magnetic properties of IONPs and to maximize their blood half-life, thin, strongly bonded, functionalized coatings are required. The work reported herein demonstrates the successful application of phosphonate-anchored self-assembled monolayers (SAMs) as ultrathin coatings for such particles. It also describes a new chemical approach to the anchoring of antibodies on the surface of SAM-coated IONPs (using nucleophilic aromatic substitution). This anchoring strategy results in stable, nonhydrolyzable, covalent attachment and allows the reactivity of the particles toward antibody binding to be activated in situ, such that prior to the activation the modified surface is stable for long-term storage. While the SAMs do not have the well-packed crystallinity of other such monolayers, their structure was studied using smooth model substrates based on an iron oxide layer on a double-side polished silicon wafer. In this way, atomic force microscopy, ellipsometry, and contact angle goniometry (tools that could not be applied to the nanoparticles' surfaces) could contribute to the determination of their monomolecular thickness and uniformity. Finally, the successful conjugation of IgG antibodies to the SAM-coated IONPs such that the antibodies retain their biological activity is verified by their complexation to a secondary fluorescent antibody.

  19. Reactions of (chloroethynyl)phosphonates with neutral nucleophiles

    SciTech Connect

    Garibina, V.A.; Leonov, A.A.; Dogadina, A.V.; Ionin, B.I.; Petrov, A.A.

    1987-12-20

    The authors studied reactions of (chloroethynyl)phosphonates with a number of neutral nucleophiles containing a primary amino group together with a second nucleophilic center. The phosphorylated benzimidazoles are crystalline substances. The chemical shift of phosphorus in these compounds, delta/sub p/ +22.0 ppm, is characteristic for compounds containing an sp/sup 3/-hybridized carbon atom attached to phosphorus. The PMR spectra of the compounds contain a characteristic signal of the protons of a methylene group attached to phosphorus, delta 2.8, /sup 2/J/sub HP/ 22.0 Hz. The /sup 13/C NMR spectrum of the compounds contain the signals of a methoxy group on phosphorus delta/sub C/(CH/sub 3/O) 49.50 ppm, J/sub CP/ 6.9 Hz; and a doublet signal of the carbon atom of the methylene group delta/sub C/ 23.16 ppm, J/sub CP/ 138.8 Hz; and a doublet of carbon of the benzimidazole ring delta/sub C/ 141.6 ppm, J/sub CP/ 8.7 Hz; the carbon atoms of the benzene ring resonate in the weak field.

  20. SF2312 is a natural phosphonate inhibitor of Enolase

    PubMed Central

    Maxwell, David; Lin, Yu-Hsi; Hammoudi, Naima; Peng, Zhenghong; Pisaneschi, Federica; Link, Todd M.; Lee, Gilbert R.; Sun, Duoli; Prasad, Basvoju A. Bhanu; Di Francesco, Maria Emilia; Czako, Barbara; Asara, John M.; Wang, Y. Alan; Bornmann, William; DePinho, Ronald A.; Muller, Florian L.

    2016-01-01

    Despite being critical for energy generation in most forms of life, few if any microbial antibiotics specifically inhibit glycolysis. To develop a specific inhibitor of the glycolytic enzyme Enolase 2 for the treatment of cancers with deletion of Enolase 1, we modeled the synthetic tool compound inhibitor, Phosphonoacetohydroxamate (PhAH) into the active site of human ENO2. A ring-stabilized analogue of PhAH, with the hydroxamic nitrogen linked to the alpha-carbon by an ethylene bridge, was predicted to increase binding affinity by stabilizing the inhibitor in a bound conformation. Unexpectedly, a structure based search revealed that our hypothesized back-bone-stabilized PhAH bears strong similarity to SF2312, a phosphonate antibiotic of unknown mode of action produced by the actinomycete Micromonospora, which is active under anaerobic conditions. Here, we present multiple lines of evidence, including a novel X-ray structure, that SF2312 is a highly potent, low nM inhibitor of Enolase. PMID:27723749