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Sample records for acid model compounds

  1. Model compounds of humic acid and oxovanadium cations. Potentiometric titration and EPR spectroscopy studies

    Directory of Open Access Journals (Sweden)

    Mercê Ana Lucia Ramalho

    1999-01-01

    Full Text Available The stability constants and the isotropic EPR parameters Ao (hyperfine splitting constant and g o (g value were obtained by potentiometric titrations and EPR spectroscopy, respectively, of 85%v/v aqueous solutions of model compounds of humic acids - salicylic acid (SALA - and both nitrohumic acids, a laboratory artifact - nitrosalicylic acids, 3-nitrosalicylic acid (3-NSA, 5-nitrosalicylic acid (5-NSA and 3,5-dinitrosalicylic acid (3,5-DNSA and oxovanadium cations. It was possible to record EPR spectra of those model compounds and the ion VO2+ (V(IV, and the stability constants were obtained from a solution of VO3+ (V(V, the values for the logarithms of the stability constants ranging from 12.77 ± 0.04 to 7.06 ± 0.05 for the species ML, and from 9.90 ±0.04 to 4.06 ± 0.05 for the species ML2 according to the decrease in the acidity of the carboxylic and the hydroxyl groups in the aromatic ring of the model compounds studied as the -NO2 substituents were added. Species distribution diagrams were also obtained for the equilibria studied. The EPR parameters showed that as the logarithm of the overall stability constants increase, g o values also increase, while Ao values show a tendency to decrease.

  2. Model compounds for heavy crude oil components and tetrameric acids: Characterization and interfacial behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Nordgaard, Erland Loeken

    2009-07-01

    The tendency during the past decades in the quality of oil reserves shows that conventional crude oil is gradually being depleted and the demand being replaced by heavy crude oils. These oils contain more of a class high-molecular weight components termed asphaltenes. This class is mainly responsible for stable water-in-crude oil emulsions. Both heavy and lighter crude oils in addition contain substantial amounts of naphthenic acids creating naphthenate deposits in topside facilities. The asphaltene class is defined by solubility and consists of several thousand different structures which may behave differently in oil-water systems. The nature of possible sub fractions of the asphaltene has been received more attention lately, but still the properties and composition of such is not completely understood. In this work, the problem has been addressed by synthesizing model compounds for the asphaltenes, on the basis that an acidic function incorporated could be crucial. Such acidic, poly aromatic surfactants turned out to be highly inter facially active as studied by the pendant drop technique. Langmuir monolayer compressions combined with fluorescence of deposited films indicated that the interfacial activity was a result of an efficient packing of the aromatic cores in the molecules, giving stabilizing interactions at the o/w interface. Droplet size distributions of emulsions studied by PFG NMR and adsorption onto hydrophilic silica particles demonstrated the high affinity to o/w interfaces and that the efficient packing gave higher emulsion stability. Comparing to a model compound lacking the acidic group, it was obvious that sub fractions of asphaltenes that contain an acidic, or maybe similar hydrogen bonding functions, could be responsible for stable w/o emulsions. Indigenous tetrameric acids are the main constituent of calcium naphthenate deposits. Several synthetic model tetra acids have been prepared and their properties have been compared to the indigenous

  3. Priming of plant resistance by natural compounds. Hexanoic acid as a model

    Directory of Open Access Journals (Sweden)

    Paz eAranega Bou

    2014-10-01

    Full Text Available Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance phenomenon. The data presented in this review reflect the novel contributions made from studying these natural plant inducers, with special emphasis placed on hexanoic acid (Hx, proposed herein as a model tool for this research field. Hx is a potent natural priming agent of proven efficiency in a wide range of host plants and pathogens. It can early activate broad-spectrum defenses by inducing callose deposition and the SA and JA pathways. Later it can prime pathogen-specific responses according to the pathogen’s lifestyle. Interestingly, Hx primes redox-related genes to produce an anti-oxidant protective effect, which might be critical for limiting the infection of necrotrophs. Our Hx-induced resistance (Hx-IR findings also strongly suggest that it is an attractive tool for the molecular characterization of the plant alarmed state, with the added advantage of it being a natural compound.

  4. A model compound (methyl oleate, oleic acid, triolein) study of triglycerides hydrodeoxygenation over alumina-supported NiMo sulfide

    NARCIS (Netherlands)

    Coumans, A.E.; Hensen, E.J.M.

    We studied hydrodeoxygenation of model compounds for vegetable oil into diesel-range hydrocarbons on a sulfided NiMo/γ-Al2O3 catalyst under trickle-flow conditions. Methyl oleate (methyl ester of oleic acid, a C18 fatty acid with one unsaturated bond in the chain) represented the C18 alkyl esters in

  5. Radiation chemistry of salicylic and methyl substituted salicylic acids: Models for the radiation chemistry of pharmaceutical compounds

    International Nuclear Information System (INIS)

    Ayatollahi, Shakiba; Kalnina, Daina; Song, Weihua; Turks, Maris; Cooper, William J.

    2013-01-01

    Salicylic acid and its derivatives are components of many medications and moieties found in numerous pharmaceutical compounds. They have been used as models for various pharmaceutical compounds in pharmacological studies, for the treatment of pharmaceuticals and personal care products (PPCPs), and, reactions with natural organic matter (NOM). In this study, the radiation chemistry of benzoic acid, salicylic acid and four methyl substituted salicylic acids (MSA) is reported. The absolute bimolecular reaction rate constants for hydroxyl radical reaction with benzoic and salicylic acids as well as 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-salicylic acid were determined (5.86±0.54)×10 9 , (1.07±0.07)×10 10 , (7.48±0.17)×10 9 , (7.31±0.29)×10 9 , (5.47±0.25)×10 9 , (6.94±0.10)×10 9 (M −1 s −1 ), respectively. The hydrated electron reaction rate constants were measured (3.02±0.10)×10 9 , (8.98±0.27)×10 9 , (5.39±0.21)×10 9 , (4.33±0.17)×10 9 , (4.72±0.15)×10 9 , (1.42±0.02)×10 9 (M −1 s −1 ), respectively. The transient absorption spectra for the six model compounds were examined and their role as model compounds for the radiation chemistry of pharmaceuticals investigated. - Highlights: • Free radical chemistry of salicylic and 4 methyl salicylic acids is investigated. • The transient absorptions spectra for model compounds are measured. • Absolute bimolecular reaction rate constants for hydroxyl radical are determined. • Solvated electron reaction rate constants are calculated. • The use of salicylic acids as models for pharmaceuticals is explored

  6. Decomposition of lignin model compounds by Lewis acid catalysts in water and ethanol

    NARCIS (Netherlands)

    Guvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Emiel J. M.

    2015-01-01

    The conversion of benzyl phenyl ether, diphenyl ether, diphenyl methane and biphenyl as representative model compounds for alpha-O-4, 5-O-4, alpha(1) (methylene bridges) and 5-5' lignin linkages was investigated. We compared the use of metal chlorides and acetates. The reactions were studied in sub-

  7. Radiolysis of N-acetyl amino acids as model compounds for radiation degradation of polypeptides

    International Nuclear Information System (INIS)

    Garrett, R.W.; Hill, D.J.T.; Ho, S.Y.; O'Donnell, J.H.; O'Sullivan, P.W.; Pomery, P.J.

    1982-01-01

    Radiation chemical yields of (i) the volatile radiolysis products and (ii) the trapped free radicals from the γ-radiolysis of the N-acetyl derivatives of glycine, L-alanine, L-valine, L-phenylalanine and L-tyrosine in the polycrystalline state have been determined at room temperature (303 K). Carbon dioxide was found to be the major molecular product for all these compounds with G(CO 2 ) varying from 0.36 for N-acetyl-L-tyrosine to 8 for N-acetyl-L-valine. There was evidence for some scission of the N-Csub(α) bond, indicated by the production of acetamide and the corresponding aliphatic acid, but the deamination reaction was found to be of much lesser importance than the decarboxylation reaction. A protective effect of the aromatic ring in N-acetyl-L-phenylalanine and in N-acetyl-L-tyrosine was indicated by the lower yields of volatile products for these compounds. The yields of trapped free radicals were found to vary with the nature of the amino acid side chain, increasing with chain length and chain branching. The radical yields were decreased by incorporation of an aromatic moiety in the side chain, this effect being greater for the tyrosyl side chain than for the phenyl side chain. The G(R) values showed a good correlation with G(CO 2 ) indicating that a common reaction may be involved in radical production and carbon dioxide formation. (author)

  8. Advanced Model Compounds for Understanding Acid-Catalyzed Lignin Depolymerization: Identification of Renewable Aromatics and a Lignin-Derived Solvent.

    Science.gov (United States)

    Lahive, Ciaran W; Deuss, Peter J; Lancefield, Christopher S; Sun, Zhuohua; Cordes, David B; Young, Claire M; Tran, Fanny; Slawin, Alexandra M Z; de Vries, Johannes G; Kamer, Paul C J; Westwood, Nicholas J; Barta, Katalin

    2016-07-20

    The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity of this aromatic biopolymer. While overly simplified model compounds often lack relevance to the chemistry of lignin, the direct use of lignin streams poses significant analytical challenges to methodology development. Ideally, new methods should be tested on model compounds that are complex enough to mirror the structural diversity in lignin but still of sufficiently low molecular weight to enable facile analysis. In this contribution, we present a new class of advanced (β-O-4)-(β-5) dilinkage models that are highly realistic representations of a lignin fragment. Together with selected β-O-4, β-5, and β-β structures, these compounds provide a detailed understanding of the reactivity of various types of lignin linkages in acid catalysis in conjunction with stabilization of reactive intermediates using ethylene glycol. The use of these new models has allowed for identification of novel reaction pathways and intermediates and led to the characterization of new dimeric products in subsequent lignin depolymerization studies. The excellent correlation between model and lignin experiments highlights the relevance of this new class of model compounds for broader use in catalysis studies. Only by understanding the reactivity of the linkages in lignin at this level of detail can fully optimized lignin depolymerization strategies be developed.

  9. Preliminary characterization of wild lactic acid bacteria and their abilities to produce flavour compounds in ripened model cheese system.

    Science.gov (United States)

    Randazzo, C L; De Luca, S; Todaro, A; Restuccia, C; Lanza, C M; Spagna, G; Caggia, C

    2007-08-01

    The aim of this work was to preliminary characterize wild lactic acid bacteria (LAB), previously isolated during artisanal Pecorino Siciliano (PS) cheese-making for technological and flavour formation abilities in a model cheese system. Twelve LAB were studied for the ability to grow at 10 and 45 degrees C, to coagulate and acidify both reconstituted skim milk and ewe's milk. Moreover, the capacity of the strains to generate aroma compounds was evaluated in a model cheese system at 30- and 60-day ripening. Flavour compounds were screened by sensory analysis and throughout gas chromatography (GC)-mass spectrometry (MS). Most of the strains were able to grow both at 10 and 45 degrees C and exhibited high ability to acidify and coagulate ewes' milk. Sensory evaluation revealed that the wild strains produced more significant flavour attributes than commercial strains in the 60-day-old model cheese system. GC-MS data confirmed the results of sensory evaluations and showed the ability of wild lactobacilli to generate key volatile compounds. Particularly, three wild lactobacilli strains, belonging to Lactobacillus casei, Lb. rhamnosus and Lb. plantarum species, generated both in 60- and 30-day-old model cheeses system, the 3-methyl butan(al)(ol) compound, which is associated with fruity taste. The present work preliminarily demonstrated that the technological and flavour formation abilities of the wild strains are strain-specific and that wild lactobacilli, which produced key flavour compounds during ripening, could be used as tailor-made starters. This study reports the technological characterization and flavour formation ability of wild LAB strains isolated from artisanal Pecorino cheese and highlights that the catabolic activities were highly strain dependent. Hence, wild lactobacilli could be selected as tailor-made starter cultures for the PS cheese manufacture.

  10. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter

    2005-01-01

    rheometry indicates that the blocks of poly(acrylic acid) are placed on the surface of the microgels. The combination of these three results reveal that the microgels have a core mainly consisting of poly(N-isopropylacrylamide) and a diffuse/cloudy surface consisting mainly of poly(acrylic acid).   The core/shell......  Theoretical development within solid/liquid separation in colloidal systems is largely based on inorganic, low charged and incompressible particles. These do not reflect the properties in biosolid/organic systems. There is therefore a need for a development of colloidal and particles which mimic...

  11. Degradation of hyaluronic acid, poly- and monosaccharides, and model compounds by hypochlorite

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1998-01-01

    the site(s) of HOCl/ClO- attack, the intermediates formed, or the mechanism(s) of polymer degradation. In this study reaction of HOCl/ClO- with amides, sugars, polysaccharides, and hyaluronic acid has been monitored by UV-visible (220-340 nm) and EPR spectroscopy. UV-visible experiments have shown...

  12. Effects of Dimethylaminoethanol and Compound Amino Acid on D-Galactose Induced Skin Aging Model of Rat

    Science.gov (United States)

    Liu, Su; Chen, Zhenyu; Cai, Xia; Sun, Ying; Zhao, Cailing

    2014-01-01

    A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE) and compound amino acid (AA) in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat. PMID:25133239

  13. Effects of Dimethylaminoethanol and Compound Amino Acid on D-Galactose Induced Skin Aging Model of Rat

    Directory of Open Access Journals (Sweden)

    Su Liu

    2014-01-01

    Full Text Available A lasting dream of human beings is to reverse or postpone aging. In this study, dimethylaminoethanol (DMAE and compound amino acid (AA in Mesotherapy were investigated for their potential antiaging effects on D-galactose induced aging skin. At 18 days after D-gal induction, each rat was treated with intradermal microinjection of saline, AA, 0.1% DMAE, 0.2% DMAE, 0.1% DMAE + AA, or 0.2% DMAE + AA, respectively. At 42 days after treatment, the skin wound was harvested and assayed. Measurement of epidermal and dermal thickness in 0.1% DMAE + AA and 0.2% DMAE + AA groups appeared significantly thicker than aging control rats. No differences were found in tissue water content among groups. Hydroxyproline in 0.1% DMAE + AA, 0.2% DMAE + AA, and sham control groups was much higher than all other groups. Collagen type I, type III, and MMP-1 expression was highly upregulated in both 0.1% DMAE + AA and 0.2% DMAE + AA groups compared with aging control. In contrast, TIMP-1 expression levels of various aging groups were significantly reduced when compared to sham control. Coinjection of DMAE and AA into target tissue has marked antiaging effects on D-galactose induced skin aging model of rat.

  14. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  15. Reactions of hypoiodous acid with model compounds and the formation of iodoform in absence/presence of permanganate.

    Science.gov (United States)

    Zhao, Xiaodan; Ma, Jun; von Gunten, Urs

    2017-08-01

    The kinetics for the reactions of hypoiodous acid (HOI) with various phenols (phenol, 4-nitrophenol, 4-hydroxybenzoic acid), 3-oxopentanedioic acid (3-OPA) and flavone were investigated in the pH range of 6.0-11.0. The apparent second order rate constants for the reactions of HOI with phenolic compounds, 3-OPA, flavone and citric acid at pH 8.0 are 10-10 7  M -1 s -1 , (4.0 ± 0.3) × 10 3  M -1 s -1 , (2.5 ± 0.2) × 10 3  M -1 s -1 and permanganate/HOI/3-OPA and permanganate/iodide/3-OPA system at pH permanganate. For pH > 8.0, in presence of permanganate, iodoform formation is significantly inhibited and iodate formation enhanced, which is due to a faster permanganate-mediated HOI disproportionation to iodate compared to the iodination process. The production of reactive iodine in real waters containing iodide in contact with permanganate may lead to the formation of iodinated organic compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. PRODUCTION OF TRIFLUOROACETIC ACID COMPOUNDS

    Science.gov (United States)

    Haworth, W.N.; Stacey, M.

    1949-08-30

    A process is described for the preparation of trifluoroacetic acid. Acetone vapor diluted wlth nitrogen and fluorine also diluted with nltrogen are fed separately at a temperature of about 210 deg C into a reaction vessel containing a catalyst mass selected from-the group consisting of silver and gold. The temperature in the reaction vessel is maintained in the range of 200 deg to 250 deg C. The reaction product, trifluoroacetyl fluoride, is absorbed in aqueous alkali solution. Trifluoroacetic acid is recovered from the solution by acidification wlth an acid such as sulfuric followed by steam distillation.

  17. Advanced Model Compounds for Understanding Acid-Catalyzed Lignin Depolymerization : Identification of Renewable Aromatics and a Lignin-Derived Solvent

    NARCIS (Netherlands)

    Lahive, Ciaran W; Deuss, Peter J; Lancefield, Christopher S; Sun, Zhuohua; Cordes, David B; Young, Claire; Tran, Fanny; Slawin, Alexandra M Z; de Vries, Johannes G; Kamer, Paul C J; Westwood, Nicholas J; Barta, Katalin

    2016-01-01

    The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity of this aromatic biopolymer. While overly simplified model compounds often lack relevance to the chemistry of lignin, the direct use of lignin streams poses significant analytical challenges

  18. Catalytic Upgrading of Bio-Oil by Reacting with Olefins and Alcohols over Solid Acids: Reaction Paths via Model Compound Studies

    Directory of Open Access Journals (Sweden)

    Qingwen Wang

    2013-03-01

    Full Text Available Catalytic refining of bio-oil by reacting with olefin/alcohol over solid acids can convert bio-oil to oxygen-containing fuels. Reactivities of groups of compounds typically present in bio-oil with 1-octene (or 1-butanol were studied at 120 °C/3 h over Dowex50WX2, Amberlyst15, Amberlyst36, silica sulfuric acid (SSA and Cs2.5H0.5PW12O40 supported on K10 clay (Cs2.5/K10, 30 wt. %. These compounds include phenol, water, acetic acid, acetaldehyde, hydroxyacetone, d-glucose and 2-hydroxymethylfuran. Mechanisms for the overall conversions were proposed. Other olefins (1,7-octadiene, cyclohexene, and 2,4,4-trimethylpentene and alcohols (iso-butanol with different activities were also investigated. All the olefins and alcohols used were effective but produced varying product selectivities. A complex model bio-oil, synthesized by mixing all the above-stated model compounds, was refined under similar conditions to test the catalyst’s activity. SSA shows the highest hydrothermal stability. Cs2.5/K10 lost most of its activity. A global reaction pathway is outlined. Simultaneous and competing esterification, etherfication, acetal formation, hydration, isomerization and other equilibria were involved. Synergistic interactions among reactants and products were determined. Acid-catalyzed olefin hydration removed water and drove the esterification and acetal formation equilibria toward ester and acetal products.

  19. Prediction of the chromatographic retention of acid-base compounds in pH buffered methanol-water mobile phases in gradient mode by a simplified model.

    Science.gov (United States)

    Andrés, Axel; Rosés, Martí; Bosch, Elisabeth

    2015-03-13

    Retention of ionizable analytes under gradient elution depends on the pH of the mobile phase, the pKa of the analyte and their evolution along the programmed gradient. In previous work, a model depending on two fitting parameters was recommended because of its very favorable relationship between accuracy and required experimental work. It was developed using acetonitrile as the organic modifier and involves pKa modeling by means of equations that take into account the acidic functional group of the compound (carboxylic acid, protonated amine, etc.). In this work, the two-parameter predicting model is tested and validated using methanol as the organic modifier of the mobile phase and several compounds of higher pharmaceutical relevance and structural complexity as testing analytes. The results have been quite good overall, showing that the predicting model is applicable to a wide variety of acid-base compounds using mobile phases prepared with acetonitrile or methanol. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Oleic acid and docosahexaenoic acid cause an increase in the paracellular absorption of hydrophilic compounds in an experimental model of human absorptive enterocytes

    International Nuclear Information System (INIS)

    Aspenstroem-Fagerlund, Bitte; Ring, Linda; Aspenstroem, Pontus; Tallkvist, Jonas; Ilbaeck, Nils-Gunnar; Glynn, Anders W.

    2007-01-01

    Surface active compounds present in food possibly have the ability to enhance the absorption of water soluble toxic agents. Therefore, we investigated whether fatty acids such as oleic acid and docosahexaenoic acid (DHA), both commonly present in food, negatively affect the integrity of tight junctions (TJ) in the intestinal epithelium and thereby increase the absorption of poorly absorbed hydrophilic substances. Caco-2 cells, which are derived from human absorptive enterocytes, were grown on permeable filters for 20-25 days. Differentiated cell monolayers were apically exposed for 90 min to mannitol in emulsions of oleic acid (5, 15 or 30 mM) or DHA (5, 15 or 30 mM) in an experimental medium with or without Ca 2+ and Mg 2+ . Absorption of 14 C-mannitol increased and trans-epithelial electrical resistance (TEER) decreased in cell monolayers exposed to oleic acid and DHA, compared to controls. Cytotoxicity, measured as leakage of LDH, was higher in groups exposed to 30 mM oleic acid and all concentrations of DHA. Morphology of the cell monolayers was studied by using fluorescence microscopy. Exposure of cell monolayers to 5 mM DHA for 90 min resulted in a profound alteration of the cell-cell contacts as detected by staining the cells for β-catenin. Oleic acid (30 mM) treatment also induced dissolution of the cell-cell contacts but the effect was not as pronounced as with DHA. Cell monolayers were also exposed for 180 min to 250 nM cadmium (Cd) in emulsions of oleic acid (5 or 30 mM) or DHA (1 or 5 mM), in an experimental medium with Ca 2+ and Mg 2+ . Retention of Cd in Caco-2 cells was higher after exposure to 5 mM oleic acid but lower after exposure to 30 mM oleic acid and DHA. Absorption of Cd through the monolayers increased after DHA exposure but not after exposure to oleic acid. Our results indicate that fatty acids may compromise the integrity of the intestinal epithelium and that certain lipids in food may enhance the paracellular absorption of poorly

  1. Treatment of phthalic acid esters by electrocoagulation with stainless steel electrodes using dimethyl phthalate as a model compound.

    Science.gov (United States)

    Kabdaşli, Işik; Keleş, Asuman; Olmez-Hanci, Tuğba; Tünay, Olcay; Arslan-Alaton, Idil

    2009-11-15

    In this study, treatment of phthalates by electrocoagulation employing stainless steel electrodes was investigated using dimethyl phthalate (DMP) as a model compound. DMP was completely destructed within 30 min up to the high initial concentration of 100mg/L while total mineralization was also obtained within a couple of hours. The applied current density of 22.5 mA/cm(2) and electrolyte (NaCl) concentrations varying between 1000 and 1500 mg/L as chloride resulted in the highest treatment performance. The initial solution pH (2-6) had practically no effect on the process efficiency. Desorption experiments and the reaction rates obtained for DMP, COD and TOC abatements appeared to be a strong evidence of an oxidative removal mechanism. DMP removal fitted first order kinetics. COD and TOC removals began after the total DMP removal and also fitted first order kinetics. Activated sludge inhibition experiments revealed that toxicity could be significantly reduced by electrocoagulation application.

  2. Molecular modeling of inorganic compounds

    National Research Council Canada - National Science Library

    Comba, Peter; Hambley, Trevor W; Martin, Bodo

    2009-01-01

    ... mechanics to inorganic and coordination compounds. Initially, simple metal complexes were modeled, but recently the field has been extended to include organometallic compounds, catalysis and the interaction of metal ions with biological macromolecules. The application of molecular mechanics to coordination compounds is complicated by the numbe...

  3. Gas-phase Conformational Analysis of (R,R)-Tartaric Acid, its Diamide, N,N,N',N'- Tetramethyldiamide and Model Compounds

    Science.gov (United States)

    Hoffmann, Marcin; Szarecka, Agnieszka; Rychlewski, Jacek

    A review over most recent ab initio studies carried out at both RHF and MP2 levels on (R,R)-tartaric acid (TA), its diamide (DA), tetramethyldiamide (TMDA) and on three prototypic model systems (each of them constitutes a half of the respective parental molecule), i.e. 2-hydroxyacetic acid (HA), 2-hydroxyacetamide (HD) and 2-hydroxy-N,N-dimethylacetamide (HMD) is presented. (R,R)-tartaric acid and the derivatives have been completely optimized at RHF/6-31G* level and subsequently single-point energies of all conformers have been calculated with the use of second order perturbation theory according to the scheme: MP2/6-31G*//RHF/6-31G*. In the complete optimization of the model molecules at RHF level we have employed relatively large basis sets, augmented with polarisation and diffuse functions, namely 3-21G, 6-31G*, 6-31++G** and 6-311++G**. Electronic correlation has been included with the largest basis set used in this study, i.e. MP2/6-311++G**//RHF/6-311++G** single-point energy calculations have been performed. General confomational preferences of tartaric acid derivatives have been analysed as well as an attempt has been made to define main factors affecting the conformational behaviour of these molecules in the isolated state, in particular, the role and stability of intramolecular hydrogen bonding. In the case of the model compounds, our study principally concerned the conformational preferences and hydrogen bonding structure within the [alpha]-hydroxy-X moiety, where X=COOH, CONH2, CON(CH3)2.

  4. 15N NMR investigation of the covalent binding of reduced TNT amines to soil humic acid, model compounds, and lignocellulose

    Science.gov (United States)

    Thorn, K.A.; Kennedy, K.R.

    2002-01-01

    The five major reductive degradation products of TNT-4ADNT (4-amino-2,6-dinitrotoluene), 2ADNT (2-amino-4,6-dinitrotoluene), 2,4DANT (2,4-diamino-6-nitrotoluene), 2,6DANT (2,6-diamino-4-nitrotoluene), and TAT (2,4,6-triaminotoluene)-labeled with 15N in the amine positions, were reacted with the IHSS soil humic acid and analyzed by 15N NMR spectrometry. In the absence of catalysts, all five amines underwent nucleophilic addition reactions with quinone and other carbonyl groups in the soil humic acid to form both heterocyclic and nonheterocyclic condensation products. Imine formation via 1,2-addition of the amines to quinone groups in the soil humic acid was significant with the diamines and TAT but not the monoamines. Horseradish peroxidase (HRP) catalyzed an increase in the incorporation of all five amines into the humic acid. In the case of the diamines and TAT, HRP also shifted the binding away from heterocyclic condensation product toward imine formation. A comparison of quantitative liquid phase with solid-state CP/MAS 15N NMR indicated that the CP experiment underestimated imine and heterocyclic nitrogens in humic acid, even with contact times optimal for observation of these nitrogens. Covalent binding of the mono- and diamines to 4-methylcatechol, the HRP catalyzed condensation of 4ADNT and 2,4DANT to coniferyl alcohol, and the binding of 2,4DANT to lignocellulose with and without birnessite were also examined.

  5. Development of Monopole Interaction Models for Ionic Compounds. Part I: Estimation of Aqueous Henry’s Law Constants for Ions and Gas Phase pKa Values for Acidic Compounds

    Science.gov (United States)

    The SPARC (SPARC Performs Automated Reasoning in Chemistry) physicochemical mechanistic models for neutral compounds have been extended to estimate Henry’s Law Constant (HLC) for charged species by incorporating ionic electrostatic interaction models. Combinations of absolute aq...

  6. COBALT COMPOUNDS AS ANTIDOTES FOR HYDROCYANIC ACID.

    Science.gov (United States)

    EVANS, C L

    1964-12-01

    The antidotal potency of a cobalt salt (acetate), of dicobalt edetate, of hydroxocobalamin and of cobinamide against hydrocyanic acid was examined mainly on mice and rabbits. All the compounds were active antidotes for up to twice the LD50; under some conditions for larger doses. The most successful was cobalt acetate for rabbits (5xLD50), which was effective at a molar cyanide/cobalt (CN/Co) ratio of 5, but had as a side-effect intense purgation. Hydroxocobalamin was irregular in action, but on the whole was most effective for mice (4.5xLD50 at a molar ratio of 1), and had no apparent side effects. Dicobalt edetate, at molar ratios of up to 2, was more effective for rabbits (3xLD50) than for mice (2xLD50), but had fewer side effects than cobalt acetate. The effect of thiosulphate was to augment the efficacy of dicobalt edetate and, in mice, that of hydroxocobalamin; but, apparently, in rabbits, to reduce that of hydroxocobalamin. Cobinamide, at a molar ratio of 1, was slightly more effective than hydroxocobalamin on rabbits and also less irregular in its action. Cobalt acetate by mouth was effective against orally administered hydrocyanic acid. The oxygen uptake of the body, reduced by cyanide, is rapidly reinstated when one of the cobalt antidotes has been successfully administered.

  7. Conversion of polar and non-polar algae oil lipids to fatty acid methyl esters with solid acid catalysts--A model compound study.

    Science.gov (United States)

    Asikainen, Martta; Munter, Tony; Linnekoski, Juha

    2015-09-01

    Bio-based fuels are becoming more and more important due to the depleting fossil resources. The production of biodiesel from algae oil is challenging compared to terrestrial vegetable oils, as algae oil consists of polar fatty acids, such as phospholipids and glycolipids, as well as non-polar triglycerides and free fatty acids common in vegetable oils. It is shown that a single sulphonated solid acid catalyst can perform the esterification and transesterification reactions of both polar and non-polar lipids. In mild reaction conditions (60-70 °C) Nafion NR50 catalyst produces methyl palmitate (FAME) from the palmitic acid derivatives of di-, and tri-glyceride, free fatty acid, and phospholipid with over 80% yields, with the glycolipid derivative giving nearly 40% yields of FAME. These results demonstrate how the polar and non-polar lipid derivatives of algal oil can be utilised as feedstocks for biodiesel production with a single catalyst in one reaction step. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Prediction of acid dissociation constants of organic compounds using group contribution methods

    DEFF Research Database (Denmark)

    Zhou, Teng; Jhamb, Spardha; Liang, Xiaodong

    2018-01-01

    data-points with average absolute error of 0.23; (b) a non-linear GC model for organic compounds using 1622 data-points with average absolute error of 1.18; (c) an artificial neural network (ANN) based GC model for the organic compounds with average absolute error of 0.17. For each of the developed......In this paper, group contribution (GC) property models for the estimation of acid dissociation constants (Ka) of organic compounds are presented. Three GC models are developed to predict the negative logarithm of the acid dissociation constant pKa: (a) a linear GC model for amino acids using 180...

  9. College Chemistry Students' Mental Models of Acids and Acid Strength

    Science.gov (United States)

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  10. Characterization, quantitation and evolution of monoepoxy compounds formed in model systems of fatty acid methyl esters and monoacid triglycerides heated at high temperature

    Directory of Open Access Journals (Sweden)

    Berdeaux, O.

    1999-02-01

    Full Text Available Monoepoxy compounds formed after heating methyl oleate and linoleate, triolein and trilinolein at 180°C for 5, 10 and 15 hours, were characterized and quantitated after derivatization to fatty acid methyl esters by using two base-catalyzed procedures. Structures were identified by GC-MS before and after hydrogénation. A complete recovery of the epoxy compounds was obtained by comparing results from methyl oleate and linoleate before and after transesterification, and good repeatability was also attained. Similar amounts of epoxides were found for methyl esters and triglycerides of the same degree of unsaturation, although formation was considerably greater for the less unsaturated substrates, methyl oleate and triolein, possibly due to the absence of remaining double bonds in the molecule which would involve a lower tendency to participate in further reactions. On other hand, independently of the degree of unsaturation of the model systems and of the period of heating, significantly higher amounts of trans isomers were formed. Finally from comparison between the amounts of epoxides and the level of polar fatty acids in samples, it was deduced that monoepoxy compounds were one of the major groups formed under the conditions used.

    En este estudio se identifican y cuantifican los compuestos epoxidados formados a partir de sistemas modelo de oleato y linoleato de metilo, trioleína y trilinoleína, calentados a 180°C durante 5,10 y 15 horas. La identificación se lleva a cabo mediante CG-EM en las muestras de esteres metílicos antes y después de someter a hidrogenación y para su cuantificación se utilizan dos procedimientos de transesterificación en medio alcalino. La comparación de las cantidades obtenidas, antes y después de la derivatización de los sistemas modelo de esteres metílicos, permitió deducir que la recuperación fue completa, obteniéndose también una excelente repetibilidad. Las cantidades de ep

  11. Anti-Inflammatory Activity in Colon Models Is Derived from Δ9-Tetrahydrocannabinolic Acid That Interacts with Additional Compounds in Cannabis Extracts

    Science.gov (United States)

    Nallathambi, Rameshprabu; Mazuz, Moran; Ion, Aurel; Selvaraj, Gopinath; Weininger, Smadar; Fridlender, Marcelo; Nasser, Ahmad; Sagee, Oded; Kumari, Puja; Nemichenizer, Diana; Mendelovitz, Maayan; Firstein, Nave; Hanin, Orly; Konikoff, Fred; Kapulnik, Yoram; Naftali, Timna; Koltai, Hinanit

    2017-01-01

    Abstract Introduction: Inflammatory bowel diseases (IBDs) include Crohn's disease, and ulcerative colitis. Cannabis sativa preparations have beneficial effects for IBD patients. However, C. sativa extracts contain hundreds of compounds. Although there is much knowledge of the activity of different cannabinoids and their receptor agonists or antagonists, the cytotoxic and anti-inflammatory activity of whole C. sativa extracts has never been characterized in detail with in vitro and ex vivo colon models. Material and Methods: The anti-inflammatory activity of C. sativa extracts was studied on three lines of epithelial cells and on colon tissue. C. sativa flowers were extracted with ethanol, enzyme-linked immunosorbent assay was used to determine the level of interleukin-8 in colon cells and tissue biopsies, chemical analysis was performed using high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance and gene expression was determined by quantitative real-time PCR. Results: The anti-inflammatory activity of Cannabis extracts derives from D9-tetrahydrocannabinolic acid (THCA) present in fraction 7 (F7) of the extract. However, all fractions of C. sativa at a certain combination of concentrations have a significant increased cytotoxic activity. GPR55 receptor antagonist significantly reduces the anti-inflammatory activity of F7, whereas cannabinoid type 2 receptor antagonist significantly increases HCT116 cell proliferation. Also, cannabidiol (CBD) shows dose dependent cytotoxic activity, whereas anti-inflammatory activity was found only for the low concentration of CBD, and in a bell-shaped rather than dose-dependent manner. Activity of the extract and active fraction was verified on colon tissues taken from IBD patients, and was shown to suppress cyclooxygenase-2 (COX2) and metalloproteinase-9 (MMP9) gene expression in both cell culture and colon tissue. Conclusions: It is suggested that the anti-inflammatory activity of Cannabis

  12. Thermal decomposition of zirconium compounds with some aromatic hydroxycarboxylic acids

    Energy Technology Data Exchange (ETDEWEB)

    Koshel, A V; Malinko, L A; Karlysheva, K F; Sheka, I A; Shchepak, N I [AN Ukrainskoj SSR, Kiev. Inst. Obshchej i Neorganicheskoj Khimii

    1980-02-01

    By the thermogravimetry method investigated are processes of thermal decomposition of different zirconium compounds with mandelic, parabromomandelic, salicylic and sulphosalicylic acids. For identification of decomposition products the specimens have been kept at the temperature of effects up to the constant weight. Taken are IR-spectra, rentgenoarams, carried out is elementary analysis of decomposition products. It is stated that thermal decomposition of the investigated compounds passes in stages; the final product of thermolysis is ZrO/sub 2/. Nonhydrolized compounds are stable at heating in the air up to 200-265 deg. Hydroxy compounds begin to decompose at lower temperature (80-100 deg).

  13. Preparation of activated petroleum coke for removal of naphthenic acids model compounds: Box-Behnken design optimization of KOH activation process.

    Science.gov (United States)

    Niasar, Hojatallah Seyedy; Li, Hanning; Das, Sreejon; Kasanneni, Tirumala Venkateswara Rao; Ray, Madhumita B; Xu, Chunbao Charles

    2018-04-01

    This study employed Box-Behnken design and response surface methodology to optimize activation parameters for the production of activated petroleum coke (APC) adsorbent from petroleum coke (PC) to achieve highest adsorption capacity for three model naphthenic acids. Activated petroleum coke (APC) adsorbent with a BET surface area of 1726 m 2 /g and total pore volume of 0.85 cc/g was produced at the optimum activation conditions (KOH/coke mass ratio) of 3.0, activation temperature 790 °C, and activation time 3.47 h). Effects of the activation parameters on the adsorption pefromances (adsortion capaciy and kinetics) were investigated. With the APC obtained at the optimum activation condition, the maximum adsorption capacity of 451, 362, and 320 (mg/g) was achieved for 2-naphthoic acid, diphenylacetic acid and cyclohexanepentanoic acid (CP), respectively. Although, generally APC adsorbents with a higher specific surface area and pore volume provide better adsorption capacity, the textural properties (surface areas and pore volume) are not the only parameters determining the APC adsorbents' adsorption capacity. Other parameters such as surface functionalities play effective roles on the adsorption capacity of the produced APC adsorbents for NAs. The KOH activation process, in particular the acid washing step, distinctly reduced the sulfur and metals contents in the raw PC, decreasing the leaching potential of metals from APC adsorbents during adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Alleviating soil acidity through plant organic compounds

    Directory of Open Access Journals (Sweden)

    Anderson R. Meda

    2001-06-01

    Full Text Available A laboratory experiment was conducted to evaluate the effects of water soluble plant extracts on soil acidity. The plant materials were: black oat, oil seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spectabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso grass, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant extracts were added on soil surface in a PVC soil column at a rate of 1.0 ml min-1. Both soil and drainage water were analyzed for pH, Ca, Al, and K. Plant extracts applied on the soil surface increased soil pH, exchangeable Ca ex and Kex and decreased Al ex. Oil seed radish, black oat, and blue lupin were the best and millet the worst materials to alleviate soil acidity. Oil seed radish markedly increased Al in the drainage water. Chemical changes were associated with the concentrations of basic cations in the plant extract: the higher the concentration the greater the effects in alleviating soil acidity.Foram conduzidos experimentos de laboratórios para avaliar os efeitos de extratos de plantas solúveis em água na acidez do solo. Os materiais de plantas foram: aveia preta, nabo, tremoço branco e azul, mucuna cinza e anã, Crotalaria spectabilis e C. breviflora, milheto, guandu, grama estrela, grama mato grosso, folhas de café, folhas de cana-de-açúcar, palhada de arroz e palhada de trigo. Foi utilizado o seguinte procedimento para o extrato da planta solúvel em água: pesar 3g de material de planta, adicionar 150 ml de água, agitar por 8h e filtrar. Os extratos de plantas foram adicionados na superfície do solo em uma coluna de PVC (1 ml min-1. Após, adicionou-se água deionizada em quantidade equivalente a três volumes de poros. Os extratos de plantas aumentaram o pH, Ca e K trocável e diminuíram Al. Nabo, aveia preta e tremoço azul foram os melhores e milheto o pior material para amenizar a acidez do solo. Nabo aumentou Al na água de drenagem. As altera

  15. Synthesis of labelled compound of ferulic acid and caffeic acid with tritium

    International Nuclear Information System (INIS)

    Yi Mingguang; Wang Caiyun

    1986-01-01

    Effective components of Chinese traditional herbs consist of many compounds, but some of the compounds usually contain unsaturated carbon-carbon double bonds. The unsaturated organic compounds 3 H-Ferulic acid and 3 H-Caffeic acid are prepared with their tritiated intermediates made by electric-dischange exposure method, which ensures the compounds contaning double bonds not hydrogenated. The 3 H-Ferulic acid is composed of 3 H-vanillin and Malonic acid. The 3 H-Caffeic acid is composed of 3 H-protocatechuyl aldehyde and Malonic acid and the specific activity of the products is 0.2 mCi/mg. The radiochemicaly purity is greater than 90%

  16. Volatile Compounds and Lactic Acid Bacteria in Spontaneous Fermented Sourdough

    International Nuclear Information System (INIS)

    Kam, W.Y.; Aida, W.M.W.; Sahilah, A.M.; Maskat, M.Y.

    2011-01-01

    The aim of this study is to identify the predominating lactic acid bacteria (LAB) in a spontaneous fermented wheat sourdough. At the same time, an investigation towards volatile compounds that were produced was also carried out. Lactobacillus plantarum has been identified as the dominant species of lactobacilli with characters of a facultative heterofermentative strain. The generated volatile compounds that were produced during spontaneous fermentation were isolated by solvent extraction method, analysed by gas chromatography (GC), and identified by mass spectrophotometer (MS). Butyric acid has been found to be the main volatile compound with relative abundance of 6.75 % and acetic acid at relative abundance of 3.60 %. Esters that were formed at relatively low amount were butyl formate (1.23 %) and cis 3 hexenyl propionate (0.05 %). Butanol was also found at low amount with relative abundance of 0.60 %. The carbohydrate metabolism of Lactobacillus plantarum may contributed to the production of acetic acid in this study via further catabolism activity on lactic acid that was produced. However, butyric acid was not the major product via fermentation by LAB but mostly carried out by the genus Clostridium via carbohydrate metabolism which needs further investigation. (author)

  17. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; Binder, Joseph B.; Gray, Michel J.; White, James F.; Zhang, Z. Conrad

    2009-09-15

    Lignin, a readily available form of biomass, awaits novel chemistry for converting it to valuable aromatic chemicals. Recent work has demonstrated that ionic liquids are excellent solvents for processing woody biomass and lignin. Seeking to exploit ionic liquids as media for depolymerization of lignin, we investigated reactions of lignin model compounds in these solvents. Using Brønsted acid catalysts in 1-ethyl-3-methylimidazolium triflate at moderate temperatures, we obtained up to 11.6% yield of the dealkylation product guaiacol from the model compound eugenol and cleaved phenethyl phenyl ether, a model for lignin ethers. Despite these successes, acid catalysis failed in dealkylation of the unsaturated model compound 4-ethylguaiacol and did not produce monomeric products from organosolv lignin, demonstrating that further work is required to understand the complex chemistry of lignin depolymerization.

  18. Determination of ferulic acid and related compounds by thin layer ...

    African Journals Online (AJOL)

    The analysis of certain phenolic compounds from plants, and their chemical transformation with microorganisms or isolated enzymes, has application in the food and pharmaceutical industry. The rapid quantitative estimation of ferulic acid by thin layer chromatography is described by measurement of the area of the ...

  19. Ascorbic acid, β-carotene, total phenolic compound and ...

    African Journals Online (AJOL)

    A two year study at Alexandria University compared ascorbic acid, β-carotene, total phenolic compound, nitrite content and microbiological quality of orange and strawberry fruits grown under organic and conventional management techniques to see if producers concerns are valid. Organically grown oranges and ...

  20. Complex compound polyvinyl alcohol-titanic acid/titanium dioxide

    Science.gov (United States)

    Prosanov, I. Yu.

    2013-02-01

    A complex compound polyvinyl alcohol-titanic acid has been produced and investigated by means of IR and Raman spectroscopy, X-ray diffraction, and synchronous thermal analysis. It is claimed that it represents an interpolymeric complex of polyvinyl alcohol and hydrated titanium oxide.

  1. Integrated modelling of two xenobiotic organic compounds

    DEFF Research Database (Denmark)

    Lindblom, Erik Ulfson; Gernaey, K.V.; Henze, Mogens

    2006-01-01

    This paper presents a dynamic mathematical model that describes the fate and transport of two selected xenobiotic organic compounds (XOCs) in a simplified representation. of an integrated urban wastewater system. A simulation study, where the xenobiotics bisphenol A and pyrene are used as reference...... compounds, is carried out. Sorption and specific biological degradation processes are integrated with standardised water process models to model the fate of both compounds. Simulated mass flows of the two compounds during one dry weather day and one wet weather day are compared for realistic influent flow...... rate and concentration profiles. The wet weather day induces resuspension of stored sediments, which increases the pollutant load on the downstream system. The potential of the model to elucidate important phenomena related to origin and fate of the model compounds is demonstrated....

  2. Modelling the ecotoxicity of naphthenic acids

    International Nuclear Information System (INIS)

    Redman, A.; McGrath, J.; Parkerton, T.; Frank, R.; Di Toro, D.

    2010-01-01

    Oil sand-derived process water is comprised of mixtures of many different toxic compounds. Recent modelling studies have been developed to assess oil sand ecotoxicity caused by naphthenic acids (NA). The hydrocarbon block method was used to described the ecotoxicity of NA mixtures using a database of physico-chemical properties for individual hydrocarbons. Chemical speciation and biota partitioning models are used to characterize the toxicity of ionizable compounds. An analysis of model predictions has suggested that high MW and compounds from the higher Z families contribute significantly to the ecotoxicity of oil sand-derived process water. However, the current modelling method overpredicts the toxicity of the highest residual fractions, which suggests that the bioavailability of the highest MW compounds is limited. Further model refinement is needed to evaluate NA compounds across a wide range of MW and Z families.

  3. Coordination compounds of cobalt and cadmium with isobutyric acid amide

    International Nuclear Information System (INIS)

    Tsivadze, A.Yu.; Ivanova, I.S.; Solovkina, O.A.

    1983-01-01

    Coordination compounds of cobalt and cadmium with isobutyric acid amide (IBAA) of Co(NCS) 2 x(IBAA) 2 (H 2 O) 2 , CoCl 2 (IBAA) 4 , CoI 2 (IBAA) 8 (H 2 O) 2 , CdI 2 (IBAA) 2 composition have been synthesized and characterized. Their infrared absorption spectra (200-400 cm -1 ), electron reflection spectra (200-750 nm) were studied. It is shown that in all compounds there are IBAA molecUles coordinated through an oxygen atom. Thiocyanogroups are coordinated throUgh nitrogen atoms

  4. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids

    Directory of Open Access Journals (Sweden)

    Hongbin Lin

    2018-05-01

    Full Text Available Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC. Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln, glutamic acid (Glu, aspartic acid (Asp and asparagines (Asn were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  5. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids.

    Science.gov (United States)

    Lin, Hongbin; Yu, Xiaoyu; Fang, Jiaxing; Lu, Yunhao; Liu, Ping; Xing, Yage; Wang, Qin; Che, Zhenming; He, Qiang

    2018-05-29

    Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC). Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln), glutamic acid (Glu), aspartic acid (Asp) and asparagines (Asn) were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  6. Reaction of acid esters of methylenebis(phosphonous acid) with carbonyl compounds

    International Nuclear Information System (INIS)

    Novikova, Z.S.; Odinets, I.L.; Lutsenko, I.F.

    1987-01-01

    The reaction of methylenebis(phosphonites) containing two hydrophosphoryl groupings with aliphatic and aromatic aldehydes and ketones in the presence of alkali metal fluorides leads to methylenebis(α-hydroxyalkylphosphinates). The reaction of methylenebis(phosphonites) containing one hydrophosphoryl groupings with carbonyl compounds in the presence of alkali metal fluorides proceeds with the formation of a new type of heterocyclic phosphorus compound, viz., 1,2λ 3 ,4λ 5 -oxadiphospholanes. The reaction of acid esters of methylenebis(phosphonous) acid with carbonyl compounds in the presence of alkali metal alkoxides or a tertiary amine is accompanied by phosphinate-phosphonate rearrangement of the intermediately formed α-hydroxylalkylphosphinates

  7. Caldensinic acid, a benzoic acid derivative and others compounds from Piper carniconnectivum

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Harley da Silva; Souza, Maria de Fatima Vanderlei de; Chaves, Maria Celia de Oliveira, E-mail: cchaves@ltf.ufpb.b [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica

    2010-07-01

    A benzoic acid derivative - caldensinic acid, E-phythyl hexadecanoate, {beta}-sitosterol and stigmasterol mixture and phaeophytin a were isolated from the aerial parts of Piper carniconnectivum. The structures of these compounds were established unambiguously by IR, MS, 1D and 2D NMR analysis. (author)

  8. using stereochemistry models in teaching organic compounds

    African Journals Online (AJOL)

    Preferred Customer

    The purpose of the study was to find out the effect of stereochemistry models on students' ... consistent with the names given to organic compounds. Some of ... Considering class level, what is the performance of the students in naming organic.

  9. Stochastic interest rates model in compounding | Galadima ...

    African Journals Online (AJOL)

    Stochastic interest rates model in compounding. ... in finance, real estate, insurance, accounting and other areas of business administration. The assumption that future rates are fixed and known with certainty at the beginning of an investment, ...

  10. Effect of vanadium compounds on acid phosphatase activity

    OpenAIRE

    Vescina, Cecilia M.; Sálice, Viviana C.; Cortizo, Ana María; Etcheverry, Susana B.

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activi...

  11. Behavior of asphaltene model compounds at w/o interfaces.

    Science.gov (United States)

    Nordgård, Erland L; Sørland, Geir; Sjöblom, Johan

    2010-02-16

    Asphaltenes, present in significant amounts in heavy crude oil, contains subfractions capable of stabilizing water-in-oil emulsions. Still, the composition of these subfractions is not known in detail, and the actual mechanism behind emulsion stability is dependent on perceived interfacial concentrations and compositions. This study aims at utilizing polyaromatic surfactants which contains an acidic moiety as model compounds for the surface-active subfraction of asphaltenes. A modified pulse-field gradient (PFG) NMR method has been used to study droplet sizes and stability of emulsions prepared with asphaltene model compounds. The method has been compared to the standard microscopy droplet counting method. Arithmetic and volumetric mean droplet sizes as a function of surfactant concentration and water content clearly showed that the interfacial area was dependent on the available surfactant at the emulsion interface. Adsorption of the model compounds onto hydrophilic silica has been investigated by UV depletion, and minor differences in the chemical structure of the model compounds caused significant differences in the affinity toward this highly polar surface. The cross-sectional areas obtained have been compared to areas from the surface-to-volume ratio found by NMR and gave similar results for one of the two model compounds. The mean molecular area for this compound suggested a tilted geometry of the aromatic core with respect to the interface, which has also been proposed for real asphaltenic samples. The film behavior was further investigated using a liquid-liquid Langmuir trough supporting the ability to form stable interfacial films. This study supports that acidic, or strong hydrogen-bonding fractions, can promote stable water-in-oil emulsion. The use of model compounds opens up for studying emulsion behavior and demulsifier efficiency based on true interfacial concentrations rather than perceived interfaces.

  12. Inhibition of Enzymatic Browning of Chlorogenic Acid by Sulfur-Containing Compounds

    NARCIS (Netherlands)

    Kuijpers, T.F.M.; Narvaez Cuenca, C.E.; Vincken, J.P.; Verloop, J.W.; Berkel, van W.J.H.; Gruppen, H.

    2012-01-01

    The antibrowning activity of sodium hydrogen sulfite (NaHSO3) was compared to that of other sulfur-containing compounds. Inhibition of enzymatic browning was investigated using a model browning system consisting of mushroom tyrosinase and chlorogenic acid (5-CQA). Development of brown color

  13. Encapsulating fatty acid esters of bioactive compounds in starch

    Science.gov (United States)

    Lay Ma, Ursula Vanesa

    Interest in the use of many bioactive compounds in foods is growing in large part because of the apparent health benefits of these molecules. However, many of these compounds can be easily degraded during processing, storage, or their passage through the gastrointestinal tract before reaching the target site. In addition, they can be bitter, acrid, or astringent, which may negatively affect the sensory properties of the product. Encapsulation of these molecules may increase their stability during processing, storage, and in the gastrointestinal tract, while providing controlled release properties. The ability of amylose to form inclusion complexes and spherulites while entrapping certain compounds has been suggested as a potential method for encapsulation of certain molecules. However, complex formation and spherulitic crystallization are greatly affected by the type of inclusion molecules, type of starch, and processing conditions. The objectives of the present investigation were to: (a) study the effect of amylose, amylopectin, and intermediate material on spherulite formation and its microstructure; (b) investigate the formation of amylose and high amylose starch inclusion complexes with ascorbyl palmitate, retinyl palmitate, and phytosterol esters; (c) evaluate the ability of spherulites to form in the presence of fatty acid esters and to entrap ascorbyl palmitate, retinyl palmitate, and phytosterol esters; and (d) evaluate the effect of processing conditions on spherulite formation and fatty acid ester entrapment. Higher ratios of linear to branched molecules resulted in the formation of more and rounder spherulites with higher heat stability. In addition to the presence of branches, it appears that spherulitic crystallization is also affected by other factors, such as degree of branching, chain length, and chain length distribution. Amylose and Hylon VII starch formed inclusion complexes with fatty acid esters of ascorbic acid, retinol, or phytosterols

  14. The quantification of free Amadori compounds and amino acids allows to model the bound Maillard reaction products formation in soybean products

    NARCIS (Netherlands)

    Troise, Antonio Dario; Wiltafsky, Markus; Fogliano, Vincenzo; Vitaglione, Paola

    2018-01-01

    The quantification of protein bound Maillard reaction products (MRPs) is still a challenge in food chemistry. Protein hydrolysis is the bottleneck step: it is time consuming and the protein degradation is not always complete. In this study, the quantitation of free amino acids and Amadori products

  15. Coordination compounds of cobalt and cadmium with isobutyric acid amide

    Energy Technology Data Exchange (ETDEWEB)

    Tsivadze, A.Yu.; Ivanova, I.S.; Solovkina, O.A. (AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii)

    1983-06-01

    Coordination compounds of cobalt and cadmium with isobutyric acid amide (IBAA) of Co(NCS)/sub 2/x(IBAA)/sub 2/(H/sub 2/O)/sub 2/, CoCl/sub 2/(IBAA)/sub 4/, CoI/sub 2/(IBAA)/sub 8/(H/sub 2/O)/sub 2/, CdI/sub 2/(IBAA)/sub 2/ composition have been synthesized and characterized. Their infrared absorption spectra (200-400 cm/sup -1/), electron reflection spectra (200-750 nm) were studied. It is shown that in all compounds there are IBAA molecUles coordinated through an oxygen atom. Thiocyanogroups are coordinated through nitrogen atoms.

  16. Effect of vanadium compounds on acid phosphatase activity.

    Science.gov (United States)

    Vescina, C M; Sálice, V C; Cortizo, A M; Etcheverry, S B

    1996-01-01

    The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activity seems to depend on the geometry around the vanadium atom more than on the oxidation state. Our results indicate a correlation between the PTPase activity and the sensitivity to vanadate and vanadyl cation.

  17. Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques.

    Science.gov (United States)

    Tres, A; Ruiz-Samblas, C; van der Veer, G; van Ruth, S M

    2013-04-15

    Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been applied to verify the geographical origin of crude palm oil (continental scale). For this purpose 94 crude palm oil samples were collected from South East Asia (55), South America (11) and Africa (28). Partial least squares discriminant analysis (PLS-DA) was used to develop a hierarchical classification model by combining two consecutive binary PLS-DA models. First, a PLS-DA model was built to distinguish South East Asian from non-South East Asian palm oil samples. Then a second model was developed, only for the non-Asian samples, to discriminate African from South American crude palm oil. Models were externally validated by using them to predict the identity of new authentic samples. The fatty acid fingerprinting model revealed three misclassified samples. The volatile compound fingerprinting models showed an 88%, 100% and 100% accuracy for the South East Asian, African and American class, respectively. The verification of the geographical origin of crude palm oil is feasible by fatty acid and volatile compound fingerprinting. Further research is required to further validate the approach and to increase its spatial specificity to country/province scale. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Mechanism of Corrosion by Naphthenic Acids and Organosulfur Compounds at High Temperatures

    Science.gov (United States)

    Jin, Peng

    Due to the law of supply and demand, the last decade has witnessed a skyrocketing in the price of light sweet crude oil. Therefore, refineries are increasingly interested in "opportunity crudes", characterized by their discounted price and relative ease of procurement. However, the attractive economics of opportunity crudes come with the disadvantage of high acid/organosulfur compound content, which could lead to corrosion and even failure of facilities in refineries. However, it is generally accepted that organosulfur compounds may form protective iron sulfide layers on the metal surface and decrease the corrosion rate. Therefore, it is necessary to investigate the corrosive property of crudes at high temperatures, the mechanism of corrosion by acids (naphthenic acids) in the presence of organosulfur compounds, and methods to mitigate its corrosive effect. In 2004, an industrial project was initiated at the Institute for Corrosion and Multiphase Technology to investigate the corrosion by naphthenic acids and organosulfur compounds. In this project, for each experiment there were two experimentation phases: pretreatment and challenge. In the first pretreatment phase, a stirred autoclave was filled with a real crude oil fraction or model oil of different acidity and organosulfur compound concentration. Then, the stirred autoclave was heated to high temperatures to examine the corrosivity of the oil to different materials (specimens made from CS and 5% Cr containing steel were used). During the pretreatment, corrosion product layers were formed on the metal surface. In the second challenge phase, the steel specimens pretreated in the first phase were inserted into a rotating cylinder autoclave, called High Velocity Rig (HVR). The HVR was fed with a high-temperature oil solution of naphthenic acids to attack the iron sulfide layers. Based on the difference of specimen weight loss between the two steps, the net corrosion rate could be calculated and the protectiveness

  19. The quantification of free Amadori compounds and amino acids allows to model the bound Maillard reaction products formation in soybean products.

    Science.gov (United States)

    Troise, Antonio Dario; Wiltafsky, Markus; Fogliano, Vincenzo; Vitaglione, Paola

    2018-05-01

    The quantification of protein bound Maillard reaction products (MRPs) is still a challenge in food chemistry. Protein hydrolysis is the bottleneck step: it is time consuming and the protein degradation is not always complete. In this study, the quantitation of free amino acids and Amadori products (APs) was compared to the percentage of blocked lysine by using chemometric tools. Eighty thermally treated soybean samples were analyzed by mass spectrometry to measure the concentration of free amino acids, free APs and the protein-bound markers of the Maillard reaction (furosine, Nε-(carboxymethyl)-l-lysine, Nε-(carboxyethyl)-l-lysine, total lysine). Results demonstrated that Discriminant Analysis (DA) and Correlated Component Regression (CCR) correctly estimated the percent of blocked lysine in a validation and prediction set. These findings indicate that the measure of free markers reflects the extent of protein damage in soybean samples and it suggests the possibility to obtain rapid information on the quality of the industrial processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Ozonisation of model compounds as a pretreatment step for the biological wastewater treatment

    International Nuclear Information System (INIS)

    Degen, U.

    1979-11-01

    Biological degradability and toxicity of organic substances are two basic criteria determining their behaviour in natural environment and during the biological treatment of waste waters. In this work oxidation products of model compounds (p-toluenesulfonic acid, benzenesulfonic acid and aniline) generated by ozonation were tested in a two step laboratory plant with activated sludge. The organic oxidation products and the initial compounds were the sole source of carbon for the microbes of the adapted activated sludge. The progress of elimination of the compounds was studied by measuring DOC, COD, UV-spectra of the initial compounds and sulfate. Initial concentrations of the model compounds were 2-4 mmole/1 with 25-75ion of sulfonic acids. As oxidation products of p-toluenesulfonic acid the following compounds were identified and quantitatively measured: methylglyoxal, pyruvic acid, oxalic acid, acetic acid, formic acid and sulfate. With all the various solutions with different concentrations of initial compounds and oxidation products the biological activity in the two step laboratory plant could maintain. p-Toluenesulfonic acid and the oxidation products are biologically degraded. The degradation of p-toluenesulfonic acid is measured by following the increasing of the sulfate concentration after biological treatment. This shows that the elimination of p-toluenesulfonic acid is not an adsorption but a mineralization step. At high p-toluenesulfonic acid concentration and low concentration of oxidation products p-toluenesulfonic acid is eliminated with a high efficiency (4.3 mole/d m 3 = 0.34 kg p-toluenesulfonic acid/d m 3 ). However at high concentration of oxidation products p-toluenesulfonic acid is less degraded. The oxidation products are always degraded with an elimination efficiency of 70%. A high load of biologically degradable oxidation products diminished the elimination efficiency of p-toluenesulfonic acid. (orig.) [de

  1. Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

    Directory of Open Access Journals (Sweden)

    F. Riccobono

    2012-10-01

    Full Text Available Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and α-pinene showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene.

    New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (Γ, defined as the ratio between the measured growth rate in the presence of α-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed Γ values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and Γ showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

  2. Antimicrobial and enhancement of the antibiotic activity by phenolic compounds: Gallic acid, caffeic acid and pyrogallol.

    Science.gov (United States)

    Lima, Valéria N; Oliveira-Tintino, Cícera D M; Santos, Enaide S; Morais, Luís P; Tintino, Saulo R; Freitas, Thiago S; Geraldo, Yuri S; Pereira, Raimundo L S; Cruz, Rafael P; Menezes, Irwin R A; Coutinho, Henrique D M

    2016-10-01

    The indiscriminate use of antimicrobial drugs has increased the spectrum of exposure of these organisms. In our studies, these phenolic compounds were evaluated: gallic acid, caffeic acid and pyrogallol. The antibacterial, antifungal and modulatory of antibiotic activities of these compounds were assayed using microdilution method of Minimum Inhibitory Concentration (MIC) to bacteria and Minimum Fungicide Concentration (MFC) to fungi. The modulation was made by comparisons of the MIC and MFC of the compounds alone and combined with drugs against bacteria and fungi respectively, using a sub-inhibitory concentration of 128 μg/mL of substances (MIC/8). All substances not demonstrated clinically relevant antibacterial activity with a MIC above ≥1024 μg/mL. As a result, we observed that the caffeic acid presented a potentiating antibacterial effect over the 3 groups of bacteria studied. Pyrogallol showed a synergistic effect with two of the antibiotics tested, but only against Staphylococcus aureus. In general, caffeic acid was the substance that presented with the greatest number of antibiotics and with the greatest number of bacteria. In relation to the antifungal activity of all the compounds, the verified results were ≥1024 μg/mL, not demonstrating significant activity. Regarding potentiation of the effect of fluconazole, was observed synergistic effect only when assayed against Candida tropicalis, with all substances. Therefore, as can be seen, the compounds presented as substances that can be promising potentiating agents of antimicrobial drugs, even though they do not have direct antibacterial and antifungal action. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

    Science.gov (United States)

    Hui Wang; Mingyue Jiang; Shujun Li; Chung-Yun Hse; Chunde Jin; Fangli Sun; Zhuo Li

    2017-01-01

    Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and...

  4. Humic Acids as Therapeutic Compounds in Lead Intoxication.

    Science.gov (United States)

    Krempaská, Klára; Vaško, Ladislav; Vašková, Janka

    2016-01-01

    The toxicity of lead and its compounds is well known, causing anemia by inhibiting the synthesis of porphyrins. The neurotoxic effects, particularly in the young, alter the structure of cell membranes and DNA. Chronic exposure to lead has adverse effects on the body by disrupting the mechanisms of energy production and tissue damage, in particular in its links with thiol groups and competition for binding sites with zinc. This review is therefore a description of the mechanism of lead toxicity as well as of possible interventions for the detoxification of the body. Part of the clinical intervention is the provision of chelates that form insoluble complexes with lead and eliminate the load in tissues. Most of these chelating agents have a number of side effects. It is therefore not surprising that active compounds with distinctive antioxidant and chelating properties are being sought after. The possibility of administering lower amounts, and the corresponding decrease in side effects, would be important for clinical practice. Both prospective studies and our initial studies on humic acids have highlighted positive effects based on their antioxidant and chelating properties.

  5. Development of methods for determining organic free radical structures by electron spin resonance and application to the radiation chemistry of nucleic acid model compounds

    International Nuclear Information System (INIS)

    Fouse, G.W. Jr.

    1977-01-01

    This project was undertaken with the objective of developing more efficient and reliable methods for the analysis of free radicals in organic single crystals. A technique was developed for the rapid calculation of single crystal ESR line positions and intensities. This method, which avoids the time-consuming matrix operations required by conventional methods, has been incorporated into a computer program for determining ESR parameters by the least-squares fitting of digitized ESR spectra. This program has been used to analyze complex spectra arising from a . CH 2 -CH 2 -O-PO 3 H - radical trapped in O-phosphorylethanolamine. A method was developed for the estimation of variance and covariance of eigenvectors and eigenvalues of experimentally-determined tensors. This error analysis is quite general, and may be applied to any tensors which can be determined by the non-linear least-squares fitting of ESR data. Monte-Carlo simulations have been employed to estimate the limitations of the approximation method. This error analysis has been included in the analysis of two phosphite radicals, - O 2 -P-OX, found in single crystals of O-phosphorylethanolamine. To aid in the formulation and evaluation of free radical models, a generalized method for the calculation of theoretically-expected hyperfine coupling tensors for arbitrary radical models was developed. Tensors are calculated for a furan-type radical which may be found in 5' dCMP. These calculated tensors are compared with tensors determined by an ENDOR experiment. Two ENDOR studies were done, one in 5' dCMP, the other in L-asparagine. The observed radical in 5' dCMP is allylic, characterized by coupling to three α-hydrogens. In L-asparagine, the dominant room-temperature radical has the form CO(NH 2 )CHCH(N + H 3 )CO 2 - . In both these studies, a series of molecular orbital calculations were performed as a means of substantiating the postulated radical structures

  6. Hydrodeoxygenation of mono- and dimeric lignin model compounds on noble metal catalysts

    NARCIS (Netherlands)

    Guvenatam, Burcu; Kursun, Osman; Heeres, Hero; Pidko, Evgeny A.; Hensen, Emiel J. M.

    2014-01-01

    The influence of reaction conditions (temperature, acidity) on the catalytic performance of supported Pt, Pd and Ru catalysts for the aqueous phase hydrodeoxygenation (HDO) of lignin model compounds was systematically investigated. Phenol conversion proceeds via hydrogenation of the aromatic ring

  7. Accurate prediction of the toxicity of benzoic acid compounds in mice via oral without using any computer codes

    International Nuclear Information System (INIS)

    Keshavarz, Mohammad Hossein; Gharagheizi, Farhad; Shokrolahi, Arash; Zakinejad, Sajjad

    2012-01-01

    Highlights: ► A novel method is introduced for desk calculation of toxicity of benzoic acid derivatives. ► There is no need to use QSAR and QSTR methods, which are based on computer codes. ► The predicted results of 58 compounds are more reliable than those predicted by QSTR method. ► The present method gives good predictions for further 324 benzoic acid compounds. - Abstract: Most of benzoic acid derivatives are toxic, which may cause serious public health and environmental problems. Two novel simple and reliable models are introduced for desk calculations of the toxicity of benzoic acid compounds in mice via oral LD 50 with more reliance on their answers as one could attach to the more complex outputs. They require only elemental composition and molecular fragments without using any computer codes. The first model is based on only the number of carbon and hydrogen atoms, which can be improved by several molecular fragments in the second model. For 57 benzoic compounds, where the computed results of quantitative structure–toxicity relationship (QSTR) were recently reported, the predicted results of two simple models of present method are more reliable than QSTR computations. The present simple method is also tested with further 324 benzoic acid compounds including complex molecular structures, which confirm good forecasting ability of the second model.

  8. Selective Oxidation of Lignin Model Compounds.

    Science.gov (United States)

    Gao, Ruili; Li, Yanding; Kim, Hoon; Mobley, Justin K; Ralph, John

    2018-05-02

    Lignin, the planet's most abundant renewable source of aromatic compounds, is difficult to degrade efficiently to welldefined aromatics. We developed a microwave-assisted catalytic Swern oxidation system using an easily prepared catalyst, MoO 2 Cl 2 (DMSO) 2 , and DMSO as the solvent and oxidant. It demonstrated high efficiency in transforming lignin model compounds containing the units and functional groups found in native lignins. The aromatic ring substituents strongly influenced the selectivity of β-ether phenolic dimer cleavage to generate sinapaldehyde and coniferaldehyde, monomers not usually produced by oxidative methods. Time-course studies on two key intermediates provided insight into the reaction pathway. Owing to the broad scope of this oxidation system and the insight gleaned with regard to its mechanism, this strategy could be adapted and applied in a general sense to the production of useful aromatic chemicals from phenolics and lignin. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Modeling Compound Flood Hazards in Coastal Embayments

    Science.gov (United States)

    Moftakhari, H.; Schubert, J. E.; AghaKouchak, A.; Luke, A.; Matthew, R.; Sanders, B. F.

    2017-12-01

    Coastal cities around the world are built on lowland topography adjacent to coastal embayments and river estuaries, where multiple factors threaten increasing flood hazards (e.g. sea level rise and river flooding). Quantitative risk assessment is required for administration of flood insurance programs and the design of cost-effective flood risk reduction measures. This demands a characterization of extreme water levels such as 100 and 500 year return period events. Furthermore, hydrodynamic flood models are routinely used to characterize localized flood level intensities (i.e., local depth and velocity) based on boundary forcing sampled from extreme value distributions. For example, extreme flood discharges in the U.S. are estimated from measured flood peaks using the Log-Pearson Type III distribution. However, configuring hydrodynamic models for coastal embayments is challenging because of compound extreme flood events: events caused by a combination of extreme sea levels, extreme river discharges, and possibly other factors such as extreme waves and precipitation causing pluvial flooding in urban developments. Here, we present an approach for flood risk assessment that coordinates multivariate extreme analysis with hydrodynamic modeling of coastal embayments. First, we evaluate the significance of correlation structure between terrestrial freshwater inflow and oceanic variables; second, this correlation structure is described using copula functions in unit joint probability domain; and third, we choose a series of compound design scenarios for hydrodynamic modeling based on their occurrence likelihood. The design scenarios include the most likely compound event (with the highest joint probability density), preferred marginal scenario and reproduced time series of ensembles based on Monte Carlo sampling of bivariate hazard domain. The comparison between resulting extreme water dynamics under the compound hazard scenarios explained above provides an insight to the

  10. Catalytic hydroprocessing of simulated coal tars. 2. Effect of acid catalysts on the hydroconversion of model compounds on a sulphided Ni-Mo/Al/sub 2/O/sub 3/ catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lemberton, J.L.; Touzeyidio, M.; Guisnet, M. (Laboratoire de Catalyse en Chimie Organique CNRS, Poitiers (France))

    1989-09-15

    Acid catalysts were added to sulphided Ni-Mo/Al/sub 2/O/sub 3/ catalyst in order to obtain a higher hydrocracking activity. The hydroconversion of phenanthrene, alone or in the presence of carbazole and/or 1-naphthol, was chosen as a model reaction. The presence of acid catalysts greatly increases the conversion of phenanthrene and allows significant amounts of light products to be obtained. In the presence of carbazole or of 1-naphthol, acid catalysts create a small increase in phenanthrene conversion, but light products are no longer obtained as the acid sites are poisoned either by adsorption of ammonia from carbazole decomposition, or by extensive coke deposition generated from 1-naphthol. In the presence of carbazole and 1-naphthol, there is no longer any effect of the acid catalysts on the hydroconversion of phenanthrene, owing to complete inhibition of the acid sites. 12 refs., 5 tabs.

  11. Fate of aliphatic compounds in nitric acid processing solutions

    International Nuclear Information System (INIS)

    Clark, W.E.; Howerton, W.B.

    1975-01-01

    The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

  12. Acidic organic compounds in beverage, food, and feed production.

    Science.gov (United States)

    Quitmann, Hendrich; Fan, Rong; Czermak, Peter

    2014-01-01

    Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications.

  13. Compound list: tannic acid [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available tannic acid TAN 00093 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/...in_vitro/tannic_acid.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_...vitro/tannic_acid.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/...Liver/Single/tannic_acid.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc.jp/

  14. Compound list: mefenamic acid [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available mefenamic acid MEF 00084 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Hum...an/in_vitro/mefenamic_acid.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/R...at/in_vitro/mefenamic_acid.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat.../in_vivo/Liver/Single/mefenamic_acid.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosc

  15. Compound list: nicotinic acid [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available nicotinic acid NIC 00081 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Hum...an/in_vitro/nicotinic_acid.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/R...at/in_vitro/nicotinic_acid.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat.../in_vivo/Liver/Single/nicotinic_acid.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosc

  16. Compound list: valproic acid [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available valproic acid VPA 00005 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/valpr...oic_acid.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/valpr...oic_acid.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/valpr...edbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/valproic_acid.Rat.in_vivo.Liver.Repeat.zip ftp:...//ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/valproic_acid.Rat.in_vivo.Kidne

  17. Investigation on chemistry of model compounds of technetium radiopharmaceuticals

    International Nuclear Information System (INIS)

    Muenze, R.; Hartmann, E.

    1983-01-01

    The report summarized experimental and theoretical results concerning the chemical structures and the biodistribution of hydrophilic technetium chelates with hydroxycarboxylic and aminopolycarboxylic acids, thiol compounds and aliphatic and aromatic nitrogen compounds as ligands. Methods which are suitable for synthesizing and characterizing defined chelates of Tc(V), Tc(IV) and Tc(III) have been developed for crystlline substances and species in solution, respectively. For certain types of technetium chelates three dimensional structure models were calculated from atomic parameters. The electron energies and electron distribution of Tc(V) thiol compounds were calculated by quantum chemical methods in order to interprete physical properties of these substances. Biodistribution studies revealed relationships between the osteotropic behaviour and the structure of phosphorous and non-phosphorous technetium chelates and between the kidney uptake and ligand exchange ability of Tc(V) hydroxycarboxylates. Important parameters for the production of technetium-99m kits have been elaborated and used for the optimization of radiopharmaceuticals (bone-, kidney and hepatobiliaer agents). (author)

  18. Nitrogenous compounds stimulate glucose-derived acid production by oral Streptococcus and Actinomyces.

    Science.gov (United States)

    Norimatsu, Yuka; Kawashima, Junko; Takano-Yamamoto, Teruko; Takahashi, Nobuhiro

    2015-09-01

    Both Streptococcus and Actinomyces can produce acids from dietary sugars and are frequently found in caries lesions. In the oral cavity, nitrogenous compounds, such as peptides and amino acids, are provided continuously by saliva and crevicular gingival fluid. Given that these bacteria can also utilize nitrogen compounds for their growth, it was hypothesized that nitrogenous compounds may influence their acid production; however, no previous studies have examined this topic. Therefore, the present study aimed to assess the effects of nitrogenous compounds (tryptone and glutamate) on glucose-derived acid production by Streptococcus and Actinomyces. Acid production was evaluated using a pH-stat method under anaerobic conditions, whereas the amounts of metabolic end-products were quantified using high performance liquid chromatography. Tryptone enhanced glucose-derived acid production by up to 2.68-fold, whereas glutamate enhanced Streptococcus species only. However, neither tryptone nor glutamate altered the end-product profiles, indicating that the nitrogenous compounds stimulate the whole metabolic pathways involving in acid production from glucose, but are not actively metabolized, nor do they alter metabolic pathways. These results suggest that nitrogenous compounds in the oral cavity promote acid production by Streptococcus and Actinomyces in vivo. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  19. Formation and properties of radicals in γ-irradiated molecular compounds of urea with dicarboxylic acids

    International Nuclear Information System (INIS)

    Kasparov, M.S.; Trofimov, V.I.

    1978-01-01

    Radiation chemical yields of paramagnetic centres and their nature have been studied as well as secondary reactions in channel inclusion compounds of urea with sebacic acid and in mixed crystals of urea with succinic acid. In inclusion compounds of urea with sebacic acid the yield exceeds additive at 77 K. In mixed crystals of urea with succinic acid the yield at 77 K is equal to additive. In mixed crystals at all temperatures quazistationary concentrations of radicals are lower than in pure succinic acid. In inclusion compounds quazistationary concentration of radicals are higher than in pure sebacic acid. It has been shown that in solid two-component systems, when the nature of the components is identical, the matrix structure exerts an essential influence on the radiolysis of the system

  20. Modeling of RO/NF membrane rejections of PhACs and organic compounds : A statistical analysis

    NARCIS (Netherlands)

    Yangali-Quintanilla, V.; Kim, T.U.; Kennedy, M.; Amy, G.

    2008-01-01

    Rejections of pharmaceutical compounds (Ibuprofen, Diclofenac, Clofibric acid, Naproxen, Primidone, Phenacetin) and organic compounds (Dichloroacetic acid, Trichloroacetic acid, Chloroform, Bromoform, Trichloroethene, Perchloroethene, Carbontetrachloride, Carbontetrabromide) by NF (Filmtec, Saehan)

  1. A review on usnic acid, an interesting natural compound

    Science.gov (United States)

    Cocchietto, Moreno; Skert, Nicola; Nimis, Pier Luigi; Sava, Gianni

    2002-03-01

    Lichens are a world-widespread consortium of fungal and photosynthetic partners. Usnic acid is one of the most common and abundant lichen metabolites, well known as an antibiotic, but also endowed with several other interesting properties. This review summarises the most relevant studies on usnic acid, focusing on a number of biological activities in different fields. On the basis of the existing literature, usnic acid seems to be an exclusive lichen product. No synthetic derivatives more effective than the natural form are known. Both the (+) and (-) enantiomers of usnic acid are effective against a large variety of Gram-positive (G+) bacterial strains, including strains from clinical isolates, irrespective of their resistant phenotype. Of particular relevance is the inhibition of growth of multi-resistant strains of Streptococcus aureus, enterococci and mycobacteria. The (+)-usnic acid enantiomer appears to be selective against Streptococcus mutans without inducing perturbing side effects on the oral saprophyte flora. On the other hand, the (-)-usnic acid enantiomer is a selective natural herbicide because of its blocking action against a specific key plant enzyme. Other recognised characteristics of usnic acid are ultraviolet absorption and preserving properties. The toxicology, the in vitro anti-inflammatory effects and the mechanism of action of usnic acid need to be investigated in greater detail in order to reach clinical trials and to allow further applications. Furthermore, more research is needed to make possible intensive lichen culture, in order to produce large quantities of lichen substances for pharmaceutical, cosmetic and agricultural purposes. Some biological aspects, i.e. the possible biological roles of usnic acid, are discussed.

  2. Are intragastric N-nitroso compounds elevated after short-term acid suppression?

    NARCIS (Netherlands)

    Houben, G.M.P.; Hooi, J.D.; Brummer, R.J.M.; Stobberingh, E.E.; Stockbrügger, R.W.

    1996-01-01

    Are intragastric N-nitroso compounds elevated after short-term acid suppression? Houben GM, Hooi J, Brummer RJ, Stobberingh EE, Stockbrugger RW. Department of Gastroenterolgy, Academic Hospital Maastricht, The Netherlands. Publication Types: Clinical Trial Randomized Controlled Trial

  3. Physicochemical Profiling of α-Lipoic Acid and Related Compounds.

    Science.gov (United States)

    Mirzahosseini, Arash; Szilvay, András; Noszál, Béla

    2016-07-01

    Lipoic acid, the biomolecule of vital importance following glycolysis, shows diversity in its thiol/disulfide equilibria and also in its eight different protonation forms of the reduced molecule. In this paper, lipoic acid, lipoamide, and their dihydro derivatives were studied to quantify their solubility, acid-base, and lipophilicity properties at a submolecular level. The acid-base properties are characterized in terms of six macroscopic, 12 microscopic protonation constants, and three interactivity parameters. The species-specific basicities, the pH-dependent distribution of the microspecies, and lipophilicity parameters are interpreted by various intramolecular effects, and contribute to understanding the antioxidant, chelate-forming, and enzyme cofactor behavior of the molecules observed. © 2016 Wiley-VHCA AG, Zürich.

  4. Compounds formed by treatment of corn (Zea mays) with nitrous acid.

    Science.gov (United States)

    Archer, M C; Hansen, T J; Tannenbaum, S R

    1980-01-01

    Nitrohexane has been identified as a major product formed following treatment of corn (Zea mays) with nitrous acid. Preliminary evidence suggests that another compound isolated from the nitrosated corn is an unsaturated nitrolic acid. As an aid to the analysis of N-nitro compounds, we have characterized the response of a chemiluminescence detector (Thermal Energy Analyzer) as a function of pyrolysis chamber temperature for several nitrosamines and for an aliphatic C-nitroso compound, an aromatic C-nitro compound, a nitramine and an alkyl nitrite. The response-temperature profiles are valuable in distinguishing among the various compounds and in optimizing the sensitivity of the detector for use in chromatography. Other tests, including photolysis and stability toward nitrite-scavenging reagents, further aid in distinguishing among the various compounds.

  5. 2,4-Dichlorophenoxyacetic acid increases reserve compounds and ...

    African Journals Online (AJOL)

    The aim of this study was to develop an in vitro culture system for Senna spectabilis and to quantify contents of storage compounds and spectaline in induced calli in relation to exogenous auxin. Explants (cotyledon, hypocotyl, epicotyl, and leaf) were cultured on MS medium containing different concentrations of 2 ...

  6. Double generalized linear compound poisson models to insurance claims data

    DEFF Research Database (Denmark)

    Andersen, Daniel Arnfeldt; Bonat, Wagner Hugo

    2017-01-01

    This paper describes the specification, estimation and comparison of double generalized linear compound Poisson models based on the likelihood paradigm. The models are motivated by insurance applications, where the distribution of the response variable is composed by a degenerate distribution...... implementation and illustrate the application of double generalized linear compound Poisson models using a data set about car insurances....

  7. Interaction of arsenic compounds with model phospholipid membranes

    International Nuclear Information System (INIS)

    Jemiola-Rzeminska, Malgorzata; Rivera, Cecilia; Suwalsky, Mario; Strzalka, Kazimierz

    2007-01-01

    This study is part of a project aimed at examining the influence of arsenic on biological membranes. By the use of differential scanning calorimetry (DSC) we have followed the thermotropic behavior of multilamellar vesicles prepared from dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) upon incorporation of sodium arsenite (AsI), disodium arsenate (AsII), cacodylic acid (AsIII) and disodium methyl arsenate (AsIV). The effectiveness of perturbations exerted by various arsenic compounds on thermotropic phase transition was further analysed in terms of thermodynamic parameters: transition temperature, enthalpy and molar heat capacity, determined for lipid/As systems on the basis of heating and cooling scans. It is found that while it only has a slight influence on the thermotropic properties of DMPC, arsenic is able to significantly modify DMPE model membranes

  8. Bioconversion Using Lactic Acid Bacteria: Ginsenosides, GABA, and Phenolic Compounds.

    Science.gov (United States)

    Lee, Na-Kyoung; Paik, Hyun-Dong

    2017-05-28

    Lactic acid bacteria (LAB) are used as fermentation starters in vegetable and dairy products and influence the pH and flavors of foods. For many centuries, LAB have been used to manufacture fermented foods; therefore, they are generally regarded as safe. LAB produce various substances, such as lactic acid, β-glucosidase, and β-galactosidase, making them useful as fermentation starters. Existing functional substances have been assessed as fermentation substrates for better component bioavailability or other functions. Representative materials that were bioconverted using LAB have been reported and include minor ginsenosides, γ-aminobutyric acid, equol, aglycones, bioactive isoflavones, genistein, and daidzein, among others. Fermentation mainly involves polyphenol and polysaccharide substrates and is conducted using bacterial strains such as Streptococcus thermophilus, Lactobacillus plantarum, and Bifidobacterium sp. In this review, we summarize recent studies of bioconversion using LAB and discuss future directions for this field.

  9. Pyrolysis mechanism of microalgae Nannochloropsis sp. based on model compounds and their interaction

    International Nuclear Information System (INIS)

    Wang, Xin; Tang, Xiaohan; Yang, Xiaoyi

    2017-01-01

    Highlights: • Pyrolysis experiments were conducted by model compounds of algal components. • Interaction affected little bio-crude yield of model compounds co-pyrolysis. • Some interaction pathways between microalgae components were recommended. • N-heterocyclic compounds were further pyrolysis products of Maillard reaction products. • Surfactant synthesis (lipid-amino acids and lipid-glucose) between algal components. - Abstract: Pyrolysis is one of important pathways to convert microalgae to liquid biofuels and key components of microalgae have different chemical composition and structure, which provides a barrier for large-scale microalgae-based liquid biofuel application. Microalgae component pyrolysis mechanism should be researched to optimal pyrolysis process parameters. In this study, single pyrolysis and co-pyrolysis of microalgal components (model compounds castor oil, soybean protein and glucose) were conducted to reveal interaction between them by thermogrametric analysis and bio-crude evaluation. Castor oil (model compound of lipid) has higher pyrolysis temperature than other model compounds and has the maximum contribution to bio-crude formation. Bio-crude from soybean protein has higher N-heterocyclic compounds as well as phenols, which could be important aromatic hydrocarbon source during biorefineries and alternative aviation biofuel production. Potential interaction pathways based on model compounds are recommended including further decomposition of Maillard reaction products (MRPs) and surfactant synthesis, which indicate that glucose played an important role on pyrolysis of microalgal protein and lipid components. The results should provide necessary information for microalgae pyrolysis process optimization and large-scale pyrolysis reactor design.

  10. Synthesis of the Demospongic Compounds, (6Z, 11Z-Octadecadienoic Acid and (6Z, 11Z-Eicosadienoic Acid

    Directory of Open Access Journals (Sweden)

    V. R. Mamdapur

    1997-01-01

    Full Text Available A stereoselective synthesis of (6Z, 11Z-octadecadienoic acid (1 and (6Z, 11Z-eicosadienoic acid (2 from easily accessible pentane-1,5-diol (3 is described. Thus, compound 3 on pyranylation and oxidation gave the aldehyde 5 which was converted to the acid 7 by Wittig reaction with a suitable phosphorane. Its depyranylation and oxidation furnished the key aldehyde 9 which upon Wittig reaction with n-heptylidene and n-nonylidene phosphoranes, respectively followed by alkaline hydrolysis afforded the title acids.

  11. Formation of Flavor Compounds by Amino Acid Catabolism in Cheese (Turkish with English Abstract

    Directory of Open Access Journals (Sweden)

    2015-02-01

    Full Text Available Biochemical reactions which contribute flavor formation occur in result of proteolysis during cheese ripening. Casein as the main protein of cheese has a significant effect on the flavor and textural properties of cheeses via its degradation to small peptides and free amino acids by various factors like coagulant enzymes. Specific flavors of cheeses occur as a result of amino acid catabolism by starter and non-starter bacteria. Some flavor compounds are formed by enzymatic transformations as well as by non-enzymatic, chemical changes in cheese. In this paper, formation of flavor compounds by amino acid catabolism during cheese ripening reviewed.

  12. Key volatile aroma compounds of lactic acid fermented malt based beverages - impact of lactic acid bacteria strains.

    Science.gov (United States)

    Nsogning Dongmo, Sorelle; Sacher, Bertram; Kollmannsberger, Hubert; Becker, Thomas

    2017-08-15

    This study aims to define the aroma composition and key aroma compounds of barley malt wort beverages produced from fermentation using six lactic acid bacteria (LAB) strains. Gas chromatography mass spectrometry-olfactometry and flame ionization detection was employed; key aroma compounds were determined by means of aroma extract dilution analysis. Fifty-six detected volatile compounds were similar among beverages. However, significant differences were observed in the concentration of individual compounds. Key aroma compounds (flavor dilution (FD) factors ≥16) were β-damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Furthermore, acetaldehyde had the greatest odor activity value of up to 4266. Sensory analyses revealed large differences in the flavor profile. Beverage from L. plantarum Lp. 758 showed the highest FD factors in key aroma compounds and was correlated to fruity flavors. Therefore, we suggest that suitable LAB strain selection may improve the flavor of malt based beverages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Hydroxyapatite-phosphonoformic acid hybrid compounds prepared by hydrothermal method

    Science.gov (United States)

    Turki, Thouraya; Othmani, Masseoud; Bantignies, Jean-Louis; Bouzouita, Khaled

    2014-01-01

    Hydroxyapatites were prepared in the presence of different amounts of phosphonoformic acid (PFA) via the hydrothermal method. The obtained powders were characterized through chemical analysis, XRD, IR, 31P MAS-NMR, TEM, and TG-TDA. The XRD showed that the PFA did not affect the apatite composition. Indeed, only a reduction of the crystallite size was noted. After grafting of PFA, the IR spectroscopy revealed the appearance of new bands belonging to HPO42- and carboxylate groups of the apatite and organic moiety, respectively. Moreover, the 31P MAS-NMR spectra exhibited a peak with a low intensity assigned to the terminal phosphonate group of the organic moiety in addition to that of the apatite. Based on these results, a reaction mechanism involving the surface hydroxyl groups (tbnd Casbnd OH) of the apatite and the carboxyl group of the acid was proposed.

  14. Exploring sources of biogenic secondary organic aerosol compounds using chemical analysis and the FLEXPART model

    Directory of Open Access Journals (Sweden)

    J. Martinsson

    2017-09-01

    Full Text Available Molecular tracers in secondary organic aerosols (SOAs can provide information on origin of SOA, as well as regional scale processes involved in their formation. In this study 9 carboxylic acids, 11 organosulfates (OSs and 2 nitrooxy organosulfates (NOSs were determined in daily aerosol particle filter samples from Vavihill measurement station in southern Sweden during June and July 2012. Several of the observed compounds are photo-oxidation products from biogenic volatile organic compounds (BVOCs. Highest average mass concentrations were observed for carboxylic acids derived from fatty acids and monoterpenes (12. 3 ± 15. 6 and 13. 8 ± 11. 6 ng m−3, respectively. The FLEXPART model was used to link nine specific surface types to single measured compounds. It was found that the surface category sea and ocean was dominating the air mass exposure (56 % but contributed to low mass concentration of observed chemical compounds. A principal component (PC analysis identified four components, where the one with highest explanatory power (49 % displayed clear impact of coniferous forest on measured mass concentration of a majority of the compounds. The three remaining PCs were more difficult to interpret, although azelaic, suberic, and pimelic acid were closely related to each other but not to any clear surface category. Hence, future studies should aim to deduce the biogenic sources and surface category of these compounds. This study bridges micro-level chemical speciation to air mass surface exposure at the macro level.

  15. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    International Nuclear Information System (INIS)

    Calza, P.; Vione, D.; Minero, C.

    2014-01-01

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  16. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, P., E-mail: paola.calza@unito.it; Vione, D.; Minero, C.

    2014-09-15

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  17. Testing the compounding structure of the CP-INARCH model

    OpenAIRE

    Weiß, Christian H.; Gonçalves, Esmeralda; Lopes, Nazaré Mendes

    2017-01-01

    A statistical test to distinguish between a Poisson INARCH model and a Compound Poisson INARCH model is proposed, based on the form of the probability generating function of the compounding distribution of the conditional law of the model. For first-order autoregression, the normality of the test statistics’ asymptotic distribution is established, either in the case where the model parameters are specified, or when such parameters are consistently estimated. As the test statistics’ law involv...

  18. Biodegradation tests of mercaptocarboxylic acids, their esters, related divalent sulfur compounds and mercaptans.

    Science.gov (United States)

    Rücker, Christoph; Mahmoud, Waleed M M; Schwartz, Dirk; Kümmerer, Klaus

    2018-04-17

    Mercaptocarboxylic acids and their esters, a class of difunctional compounds bearing both a mercapto and a carboxylic acid or ester functional group, are industrial chemicals of potential environmental concern. Biodegradation of such compounds was systematically investigated here, both by literature search and by experiments (Closed Bottle Test OECD 301D and Manometric Respirometry Test OECD 301F). These compounds were found either readily biodegradable or at least biodegradable to a significant extent. Some related compounds of divalent sulfur were tested for comparison (mercaptans, sulfides, disulfides). For the two relevant monofunctional compound classes, carboxylic acids/esters and mercaptans, literature data were compiled, and by comparison with structurally similar compounds without these functional groups, the influence of COOH/COOR' and SH groups on biodegradability was evaluated. Thereby, an existing rule of thumb for biodegradation of carboxylic acids/esters was supported by experimental data, and a rule of thumb could be formulated for mercaptans. Concurrent to biodegradation, abiotic processes were observed in the experiments, rapid oxidative formation of disulfides (dimerisation of monomercaptans and cyclisation of dimercaptans) and hydrolysis of esters. Some problems that compromise the reproducibility of biodegradation test results were discussed.

  19. Some information needs for air quality modeling. [Environmental effects of sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F B

    1975-09-01

    The following topics were considered at the workshop: perturbation of the natural sulfur cycle by human activity; ecosystem responses to a given environmental dose of sulfur compounds; movement of sulfur compounds within the atmosphere; air quality models; contribution of biogenic sulfur compounds to atmospheric burden of sulfur; production of acid rain from sulfur dioxide; meteorological processes; and rates of oxidation of SO/sub 2/ via direct photo-oxidation, oxidation resulting from photo-induced free radical chemistry, and catalytic oxidation in cloud droplets and on dry particles. (HLW)

  20. Prediction model of biocrude yield and nitrogen heterocyclic compounds analysis by hydrothermal liquefaction of microalgae with model compounds.

    Science.gov (United States)

    Sheng, Lili; Wang, Xin; Yang, Xiaoyi

    2018-01-01

    The model of biocrude yield and the nitrogen heterocyclic compounds in biocrude of microalgae hydrothermal liquefaction are two of the most concerned issues in this field at present. This study explored a hydrothermal liquefaction biocrude yield model involved in the interaction among biochemical compounds in microalgae and analysed nitrogen heterocyclic compounds in biocrude. The model compound (castor oil, soya protein and glucose) and Nanochloropsis were liquefied at 280°C for 1h. The products were analyzed by GC-MS, element analysis and FTIR. The results suggested that interactions among different components in microalgae enhanced biocrude yield. The biocrude yield prediction model involved cross-interactions performed more accurate than previous models.When the ratio of protein and carbohydrate around 3, the cross-interaction and nitrogen heterocyclic compounds in biocrude would both reach the highest extent. Copyright © 2017. Published by Elsevier Ltd.

  1. Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: a biophysical approach to disease.

    Science.gov (United States)

    Pinheiro, Marina; Giner-Casares, Juan J; Lúcio, Marlene; Caio, João M; Moiteiro, Cristina; Lima, José L F C; Reis, Salette; Camacho, Luis

    2013-02-01

    This work focuses on the interaction of mycolic acids (MAs) and two antimycobacterial compounds (Rifabutin and N'-acetyl-Rifabutin) at the pulmonary membrane level to convey a biophysical perspective of their role in disease. For this purpose, accurate biophysical techniques (Langmuir isotherms, Brewster angle microscopy, and polarization-modulation infrared reflection spectroscopy) and lipid model systems were used to mimic biomembranes: MAs mimic bacterial lipids of the Mycobacterium tuberculosis (MTb) membrane, whereas Curosurf® was used as the human pulmonary surfactant (PS) membrane model. The results obtained show that high quantities of MAs are responsible for significant changes on PS biophysical properties. At the dynamic inspiratory surface tension, high amounts of MAs decrease the order of the lipid monolayer, which appears to be a concentration dependent effect. These results suggest that the amount of MAs might play a critical role in the initial access of the bacteria to their targets. Both molecules also interact with the PS monolayer at the dynamic inspiratory surface. However, in the presence of higher amounts of MAs, both compounds improve the phospholipid packing and, therefore, the order of the lipid surfactant monolayer. In summary, this work discloses the putative protective effects of antimycobacterial compounds against the MAs induced biophysical impairment of PS lipid monolayers. These protective effects are most of the times overlooked, but can constitute an additional therapeutic value in the treatment of pulmonary tuberculosis (Tb) and may provide significant insights for the design of new and more efficient anti-Tb drugs based on their behavior as membrane ordering agents. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Chemical predictive modelling to improve compound quality.

    Science.gov (United States)

    Cumming, John G; Davis, Andrew M; Muresan, Sorel; Haeberlein, Markus; Chen, Hongming

    2013-12-01

    The 'quality' of small-molecule drug candidates, encompassing aspects including their potency, selectivity and ADMET (absorption, distribution, metabolism, excretion and toxicity) characteristics, is a key factor influencing the chances of success in clinical trials. Importantly, such characteristics are under the control of chemists during the identification and optimization of lead compounds. Here, we discuss the application of computational methods, particularly quantitative structure-activity relationships (QSARs), in guiding the selection of higher-quality drug candidates, as well as cultural factors that may have affected their use and impact.

  3. Wine phenolic compounds influence the production of volatile phenols by wine-related lactic acid bacteria.

    Science.gov (United States)

    Silva, I; Campos, F M; Hogg, T; Couto, J A

    2011-08-01

    To evaluate the effect of wine phenolic compounds on the production of volatile phenols (4-vinylphenol [4VP] and 4-ethylphenol [4EP]) from the metabolism of p-coumaric acid by lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus collinoides and Pediococcus pentosaceus were grown in MRS medium supplemented with p-coumaric acid, in the presence of different phenolic compounds: nonflavonoids (hydroxycinnamic and benzoic acids) and flavonoids (flavonols and flavanols). The inducibility of the enzymes involved in the p-coumaric acid metabolism was studied in resting cells. The hydroxycinnamic acids tested stimulated the capacity of LAB to synthesize volatile phenols. Growth in the presence of hydroxycinnamic acids, especially caffeic acid, induced the production of 4VP by resting cells. The hydroxybenzoic acids did not significantly affect the behaviour of the studied strains. Some of the flavonoids showed an effect on the production of volatile phenols, although strongly dependent on the bacterial species. Relatively high concentrations (1 g l(-1) ) of tannins inhibited the synthesis of 4VP by Lact. plantarum. Hydroxycinnamic acids were the main compounds stimulating the production of volatile phenols by LAB. The results suggest that caffeic and ferulic acids induce the synthesis of the cinnamate decarboxylase involved in the metabolism of p-coumaric acid. On the other hand, tannins exert an inhibitory effect. This study highlights the capacity of LAB to produce volatile phenols and that this activity is markedly influenced by the phenolic composition of the medium. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  4. Hybrid Compounds Strategy in the Synthesis of Oleanolic Acid Skeleton-NSAID Derivatives

    Directory of Open Access Journals (Sweden)

    Anna Pawełczyk

    2016-04-01

    Full Text Available The current study focuses on the synthesis of several hybrid individuals combining a natural oleanolic acid skeleton and synthetic nonsteroidal anti-inflammatory drug moieties (NSAIDs. It studied structural modifications of the oleanolic acid structure by use of the direct reactivity of hydroxyl or hydroxyimino groups at position C-3 of the triterpenoid skeleton with the carboxylic function of anti-inflammatory drugs leading to new perspective compounds with high potential pharmacological activities. Novel ester- and iminoester-type derivatives of oleanolic unit with the different NSAIDs, such as ibuprofen, aspirin, naproxen, and ketoprofen, were obtained and characterized. Moreover, preliminary research of compounds obtaining structure stability under acidic conditions was examined and the PASS method of prediction of activity spectra for substances was used to estimate the potential biological activity of these compounds.

  5. Complexation and molecular modeling studies of europium(III)-gallic acid-amino acid complexes.

    Science.gov (United States)

    Taha, Mohamed; Khan, Imran; Coutinho, João A P

    2016-04-01

    With many metal-based drugs extensively used today in the treatment of cancer, attention has focused on the development of new coordination compounds with antitumor activity with europium(III) complexes recently introduced as novel anticancer drugs. The aim of this work is to design new Eu(III) complexes with gallic acid, an antioxida'nt phenolic compound. Gallic acid was chosen because it shows anticancer activity without harming health cells. As antioxidant, it helps to protect human cells against oxidative damage that implicated in DNA damage, cancer, and accelerated cell aging. In this work, the formation of binary and ternary complexes of Eu(III) with gallic acid, primary ligand, and amino acids alanine, leucine, isoleucine, and tryptophan was studied by glass electrode potentiometry in aqueous solution containing 0.1M NaNO3 at (298.2 ± 0.1) K. Their overall stability constants were evaluated and the concentration distributions of the complex species in solution were calculated. The protonation constants of gallic acid and amino acids were also determined at our experimental conditions and compared with those predicted by using conductor-like screening model for realistic solvation (COSMO-RS) model. The geometries of Eu(III)-gallic acid complexes were characterized by the density functional theory (DFT). The spectroscopic UV-visible and photoluminescence measurements are carried out to confirm the formation of Eu(III)-gallic acid complexes in aqueous solutions. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Computer modeling the boron compound factor in normal brain tissue

    International Nuclear Information System (INIS)

    Gavin, P.R.; Huiskamp, R.; Wheeler, F.J.; Griebenow, M.L.

    1993-01-01

    The macroscopic distribution of borocaptate sodium (Na 2 B 12 H 11 SH or BSH) in normal tissues has been determined and can be accurately predicted from the blood concentration. The compound para-borono-phenylalanine (p-BPA) has also been studied in dogs and normal tissue distribution has been determined. The total physical dose required to reach a biological isoeffect appears to increase directly as the proportion of boron capture dose increases. This effect, together with knowledge of the macrodistribution, led to estimates of the influence of the microdistribution of the BSH compound. This paper reports a computer model that was used to predict the compound factor for BSH and p-BPA and, hence, the equivalent radiation in normal tissues. The compound factor would need to be calculated for other compounds with different distributions. This information is needed to design appropriate normal tissue tolerance studies for different organ systems and/or different boron compounds

  7. Sweet taste in apple: the role of sorbitol, individual sugars, organic acids and volatile compounds

    Science.gov (United States)

    Aprea, Eugenio; Charles, Mathilde; Endrizzi, Isabella; Laura Corollaro, Maria; Betta, Emanuela; Biasioli, Franco; Gasperi, Flavia

    2017-03-01

    Sweetness is one of the main drivers of consumer preference, and thus is given high priority in apple breeding programmes. Due to the complexity of sweetness evaluation, soluble solid content (SSC) is commonly used as an estimation of this trait. Nevertheless, it has been demonstrated that SSC and sweet taste are poorly correlated. Though individual sugar content may vary greatly between and within apple cultivars, no previous study has tried to investigate the relationship between the amount of individual sugars, or ratios of these, and apple sweetness. In this work, we quantified the major sugars (sucrose, glucose, fructose, xylose) and sorbitol and explored their influence on perceived sweetness in apple; we also related this to malic acid content, SSC and volatile compounds. Our data confirmed that the correlation between sweetness and SSC is weak. We found that sorbitol content correlates (similarly to SSC) with perceived sweetness better than any other single sugar or total sugar content. The single sugars show no differentiable importance in determining apple sweetness. Our predictive model based on partial least squares regression shows that after sorbitol and SSC, the most important contribution to apple sweetness is provided by several volatile compounds, mainly esters and farnesene.

  8. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  9. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer as well as its complex side chain structures, it has been a challenge to effectively depolymerize lignin and produce high value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) inclduing 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPCs yields obtained were 18% and 22% based on the initial weight of the lignin in SESPL and DACSL respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47%. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  10. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds.

    Science.gov (United States)

    Ma, Ruoshui; Guo, Mond; Lin, Kuan-Ting; Hebert, Vincent R; Zhang, Jinwen; Wolcott, Michael P; Quintero, Melissa; Ramasamy, Karthikeyan K; Chen, Xiaowen; Zhang, Xiao

    2016-07-25

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Synthesis of esters of morpholino-4-carbothionothiolic acid as compounds of potential radioprotective action

    Energy Technology Data Exchange (ETDEWEB)

    Strzelczyk, M.; Kucharski, A. (Wojskowa Akademia Medyczna, Lodz (Poland))

    1979-01-01

    The compounds of the group of dithiocarbaminianes as complexing compounds are of importance in radioprotection. Present paper concerns the synthesis of 19, as yet undescribed dithiocarbaminianes esters of morpholino-4-carbothionothiolic acid. They were obtained in the reaction of the potassium salt of the mentioned acid with adequate alkyl or alkyloaryl halogenatas. Potassium salt of the morpholino-4-carbothionothiolic acid was obtained in the reaction of morpholine with carbon disulphite in the presence of potassium hydroxide. Obtaining of the pure potassium salt of the mentioned acid enabled the accurate calculation of the used substarate in further reactions and conduction of reaction in different solvents. Phenyloalkyl, phenacyl and morpholino-4-carbonyloalkyl esters were obtained. Their chemical structure was confirmed by elementary and spectral infrared analysis.

  12. Synthesis and study on biological activity of nitrogen-containing heterocyclic compounds – regulators of enzymes of nucleic acid biosynthesis

    Directory of Open Access Journals (Sweden)

    Alexeeva I. V.

    2013-07-01

    Full Text Available Results of investigations on the development of new regulators of functional activity of nucleic acid biosynthesis enzymes based on polycyclic nitrogen-containing heterosystems are summarized. Computer design and molecular docking in the catalytic site of target enzyme (T7pol allowed to perform the directed optimization of basic structures. Several series of compounds were obtained and efficient inhibitors of herpes family (simple herpes virus type 2, Epstein-Barr virus, influenza A and hepatitis C viruses were identified, as well as compounds with potent antitumor, antibacterial and antifungal activity. It was established that the use of model test systems based on enzymes participating in nucleic acids synthesis is a promising approach to the primary screening of potential inhibitors in vitro.

  13. Bioactive compounds from palm fatty acid distillate and crude palm oil

    Science.gov (United States)

    Estiasih, T.; Ahmadi, K.

    2018-03-01

    Crude palm oil (CPO) and palm fatty acid distillate (PFAD) are rich sources of bioactive compounds. PFAD is a by-product of palm oil refinery that produce palm frying oil. Physical refining of palm oil by deodorization produces palm fatty acid distillate. CPO and PFAD contain some bioactive compounds such as vitamin E (tocopherol and tocotrienols), phytosterol, and squalene. Bioactive compounds of CPO and PFAD are vitamin E, phytosterols, and squalene. Vitamin E of CPO and PFAD mainly comprised of tocotrienols and the remaining is tocopherol. Phytosterols of CPO and PFAD contained beta sitosterol, stigmasterol, and campesterol. Tocotrienols and phytosterols of CPO and PFAD, each can be separated to produce tocotrienol rich fraction and phytosterol rich fraction. Tocotrienol rich fraction from PFAD has both antioxidant and cholesterol lowering properties. Bioactive compounds of PFAD silmultaneously have been proven to improve lipid profile, and have hepatoprotector effect, imunomodulator, antioxidant properties, and lactogenic effect in animal test experiment. It is possible to develop separation of bioactive compounds of CPO and PFAD integratively with the other process that utilizes fatty acid.

  14. Multivariate characterisation and quantitative structure-property relationship modelling of nitroaromatic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Joensson, S. [Man-Technology-Environment Research Centre, Department of Natural Sciences, Orebro University, 701 82 Orebro (Sweden)], E-mail: sofie.jonsson@nat.oru.se; Eriksson, L.A. [Department of Natural Sciences and Orebro Life Science Center, Orebro University, 701 82 Orebro (Sweden); Bavel, B. van [Man-Technology-Environment Research Centre, Department of Natural Sciences, Orebro University, 701 82 Orebro (Sweden)

    2008-07-28

    A multivariate model to characterise nitroaromatics and related compounds based on molecular descriptors was calculated. Descriptors were collected from literature and through empirical, semi-empirical and density functional theory-based calculations. Principal components were used to describe the distribution of the compounds in a multidimensional space. Four components described 76% of the variation in the dataset. PC1 separated the compounds due to molecular weight, PC2 separated the different isomers, PC3 arranged the compounds according to different functional groups such as nitrobenzoic acids, nitrobenzenes, nitrotoluenes and nitroesters and PC4 differentiated the compounds containing chlorine from other compounds. Quantitative structure-property relationship models were calculated using partial least squares (PLS) projection to latent structures to predict gas chromatographic (GC) retention times and the distribution between the water phase and air using solid-phase microextraction (SPME). GC retention time was found to be dependent on the presence of polar amine groups, electronic descriptors including highest occupied molecular orbital, dipole moments and the melting point. The model of GC retention time was good, but the precision was not precise enough for practical use. An important environmental parameter was measured using SPME, the distribution between headspace (air) and the water phase. This parameter was mainly dependent on Henry's law constant, vapour pressure, log P, content of hydroxyl groups and atmospheric OH rate constant. The predictive capacity of the model substantially improved when recalculating a model using these five descriptors only.

  15. Hydrogen isotope exchange of organic compounds in dilute acid at elevated temperatures

    International Nuclear Information System (INIS)

    Werstiuk, N.H.

    1987-01-01

    Introduction of one or more deuterium (or tritium) atoms into organic molecules can be accomplished in many ways depending on the nature of the substrate and the extent and sterochemistry of deuteriation or tritiation required. Some of the common methods include acid- and base-catalyzed exchange of carbonyl compounds, metal hydride reductions, dissolving metal reductions, catalytic reduction of double bonds, chromatographic exchange, homogeneous and heterogeneous metal-catalyzed exchange, base-catalyzed exchange of carbon acids other than carbonyl compounds and acid-catalyzed exchange via electrophilic substitution. Only the latter three methods have been used for perdeuteriation of organic compounds. A very useful compendium of labeling methods with examples has been available to chemists for some time. Although metal-catalyzed exchange has been used extensively, the method suffers from some deficiencies: irreproducibility of catalyst surfaces, catalyst poisoning, side reactions such as coupling and hydrogenolysis of labile groups and low deuterium incorporation. Usually a number of cycles are required with fresh catalyst and fresh deuterium source to achieve substantial isotope incorporation. Acid-catalyzed exchange of aromatics and alkenes, strongly acidic media such as liquid DBr, concentrated DBr, acetic acid/stannic chloride, concentrated D 3 PO 4 , concentrated DC1, D 3 PO 4 /BF 3 SO 2 , 50-80% D 2 SO 4 and DFSO 4 /SbF 5 at moderate temperatures (<100 degrees) have been used to effect exchange. The methods are not particularly suitable for large scale deuteriations because of the cost and the fact that the recovery and upgrading of the diluted deuterium pool is difficult. This paper describes the hydrogen isotope exchange of a variety of organic compounds in dilute aqueous acid (0.1-0.5 M) at elevated temperatures (150-300 degrees)

  16. Synthesis, characterization and crystal structures of new organic compounds containing cyanoacrylic acid

    Czech Academy of Sciences Publication Activity Database

    Khalaji, A.D.; Mogheiseh, M.; Eigner, Václav; Dušek, Michal; Chow, T.J.; Maddahi, E.

    2015-01-01

    Roč. 1098, Oct (2015), s. 318-323 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : organic compounds * cyanoacrylic acid * single-crystal structure analysis * dye-sensitized solar cells * density functional theory Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.780, year: 2015

  17. Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques

    NARCIS (Netherlands)

    Tres, A.; Ruiz - Samblas, C.; Veer, van der G.; Ruth, van S.M.

    2013-01-01

    Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been

  18. Synthesis, Characterization, and Antimicrobial Activities of Coordination Compounds of Aspartic Acid

    Directory of Open Access Journals (Sweden)

    T. O. Aiyelabola

    2016-01-01

    Full Text Available Coordination compounds of aspartic acid were synthesized in basic and acidic media, with metal ligand M : L stoichiometric ratio 1 : 2. The complexes were characterized using infrared, electronic and magnetic susceptibility measurements, and mass spectrometry. Antimicrobial activity of the compounds was determined against three Gram-positive and three Gram-negative bacteria and one fungus. The results obtained indicated that the availability of donor atoms used for coordination was a function of the pH of the solution in which the reaction was carried out. This resulted in varying geometrical structures for the complexes. The compounds exhibited a broad spectrum of activity and in some cases better activity than the standard.

  19. Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations

    Science.gov (United States)

    Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

    1996-08-01

    An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that

  20. Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids.

    Science.gov (United States)

    Hayer, Kimran; Stratford, Malcolm; Archer, David B

    2014-10-01

    Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  1. Comparison of zwitterionic N-alkylaminomethanesulfonic acids to related compounds in the Good buffer series

    Directory of Open Access Journals (Sweden)

    Robert D. Long

    2010-04-01

    Full Text Available Several N-alkyl and N,N-dialkylaminomethanesulfonic acids were synthesized (as zwitterions and/or sodium salts to be tested for utility as biological buffers at lower pH levels than existing Good buffer compounds (aminoalkanesulfonates with a minimum of two carbons between amine and sulfonic acid groups as originally described by Norman Good, and in common use as biological buffers. Our hypothesis was that a shorter carbon chain (one carbon between the amino and sulfonic acid groups should lower the ammonium ion pKa values. The alkylaminomethanesulfonate compounds were synthesized in aqueous solution by reaction of primary or secondary amines with formaldehyde/sodium hydrogensulfite addition compound. The pKa values of the ammonium ions of this series of compounds (compared to existing Good buffers was found to correlate well with the length of the carbon chain between the amino and sulfonate moeties, with a significant decrease in amine basicity in the aminomethanesulfonate compounds (pKa decrease of 2 units or more compared to existing Good buffers. An exception was found for the 2-hydroxypiperazine series which shows only a small pKa decrease, probably due to the site of protonation in this compound (as confirmed by X-ray crystal structure. X-ray crystallographic structures of two members of the series are reported. Several of these compounds have pKa values that would indicate potential utility for buffering at pH levels below the normal physiological range (pKa values in the range of 3 to 6 without aqueous solubility problems – a range that is problematic for currently available Good buffers. Unfortunately, the alkylaminomethanesulfonates were found to degrade (with loss of their buffering ability at pH levels below the pKa value and were unstable at elevated temperature (as when autoclaving – thus limiting their utility.

  2. Semi classical model of the neutron resonance compound nucleus

    International Nuclear Information System (INIS)

    Ohkubo, Makio

    1995-01-01

    A Semi-classical model of compound nucleus is developed, where time evolution and recurrence for many degrees of freedom (oscillators) excited simultaneously are explicitly considered. The effective number of oscillators plays the role in the compound nucleus, and the nuclear temperatures are derived, which are in good agreement with the traditional values. Time structures of the compound nucleus at resonance are considered, from which equidistant level series with an envelope of strength function of giant resonance nature is obtained. S-matrix formulation for fine structure resonance is derived. (author)

  3. Statistical molecular design of balanced compound libraries for QSAR modeling.

    Science.gov (United States)

    Linusson, A; Elofsson, M; Andersson, I E; Dahlgren, M K

    2010-01-01

    A fundamental step in preclinical drug development is the computation of quantitative structure-activity relationship (QSAR) models, i.e. models that link chemical features of compounds with activities towards a target macromolecule associated with the initiation or progression of a disease. QSAR models are computed by combining information on the physicochemical and structural features of a library of congeneric compounds, typically assembled from two or more building blocks, and biological data from one or more in vitro assays. Since the models provide information on features affecting the compounds' biological activity they can be used as guides for further optimization. However, in order for a QSAR model to be relevant to the targeted disease, and drug development in general, the compound library used must contain molecules with balanced variation of the features spanning the chemical space believed to be important for interaction with the biological target. In addition, the assays used must be robust and deliver high quality data that are directly related to the function of the biological target and the associated disease state. In this review, we discuss and exemplify the concept of statistical molecular design (SMD) in the selection of building blocks and final synthetic targets (i.e. compounds to synthesize) to generate information-rich, balanced libraries for biological testing and computation of QSAR models.

  4. Spatial arrangement of organic compounds on a model mineral surface: implications for soil organic matter stabilization.

    Science.gov (United States)

    Petridis, Loukas; Ambaye, Haile; Jagadamma, Sindhu; Kilbey, S Michael; Lokitz, Bradley S; Lauter, Valeria; Mayes, Melanie A

    2014-01-01

    The complexity of the mineral-organic carbon interface may influence the extent of stabilization of organic carbon compounds in soils, which is important for global climate futures. The nanoscale structure of a model interface was examined here by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto a soil mineral analogue (Al2O3). Neutron reflectometry, a technique which provides depth-sensitive insight into the organization of the thin films, indicates that glucose molecules reside in a layer between Al2O3 and stearic acid, a result that was verified by water contact angle measurements. Molecular dynamics simulations reveal the thermodynamic driving force behind glucose partitioning on the mineral interface: The entropic penalty of confining the less mobile glucose on the mineral surface is lower than for stearic acid. The fundamental information obtained here helps rationalize how complex arrangements of organic carbon on soil mineral surfaces may arise.

  5. Phosphorus sorption on marine carbonate sediment: phosphonate as model organic compounds.

    Science.gov (United States)

    Huang, Xiao-Lan; Zhang, Jia-Zhong

    2011-11-01

    Organophosphonate, characterized by the presence of a stable, covalent, carbon to phosphorus (C-P) bond, is a group of synthetic or biogenic organophosphorus compounds. The fate of these organic phosphorus compounds in the environment is not well studied. This study presents the first investigation on the sorption of phosphorus (P) in the presence of two model phosphonate compounds, 2-aminothylphosphonoic acid (2-AEP) and phosphonoformic acid (PFA), on marine carbonate sediments. In contrast to other organic P compounds, no significant inorganic phosphate exchange was observed in seawater. P was found to adsorb on the sediment only in the presence of PFA, not 2-AEP. This indicated that sorption of P from phosphonate on marine sediment was compound specific. Compared with inorganic phosphate sorption on the same sediments, P sorption from organic phosphorus is much less in the marine environment. Further study is needed to understand the potential role of the organophosphonate compounds in biogeochemical cycle of phosphorus in the environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Fruit tree model for uptake of organic compounds from soil

    DEFF Research Database (Denmark)

    Trapp, Stefan; Rasmussen, D.; Samsoe-Petersen, L.

    2003-01-01

    -state, and an example calculation is given. The Fruit Tree Model is compared to the empirical equation of Travis and Arms (T&A), and to results from fruits, collected in contaminated areas. For polar compounds, both T&A and the Fruit Tree Model predict bioconcentration factors fruit to soil (BCF, wet weight based......) of > 1. No empirical data are available to support this prediction. For very lipophilic compounds (log K-OW > 5), T&A overestimates the uptake. The conclusion from the Fruit Tree Model is that the transfer of lipophilic compounds into fruits is not relevant. This was also found by an empirical study...... with PCDD/F. According to the Fruit Tree Model, polar chemicals are transferred efficiently into fruits, but empirical data to verify these predictions are lacking....

  7. Irradiation effects on polymer-model compounds

    International Nuclear Information System (INIS)

    Seguchi, Tadao; Hayakawa, Naohiro; Tamura, Naoyuki; Katsumura, Yosuke; Hayashi, Nariyuki; Tabata, Yoneho

    1991-01-01

    Irradiation effects on n-paraffins and squalane, used as models of polymers, were investigated by product analysis. Four n-paraffins, C 20 H 42 , C 21 H 44 , C 23 H 48 and C 24 H 50 , and squalane (C 30 H 62 ) were γ-irradiated under vacuum in liquid, crystalline and glassy states. The evolved gases were analyzed by gas chromatography and changes in molecular weight were analyzed by liquid chromatography and mass spectroscopy. G-values for crosslinking of n-paraffins were 1.2 for crystalline states (at 25 0 C) and 1.7 for liquid states (at 55 0 C), and showed no difference between odd and even carbon numbers. The G-value of liquid squalane was 1.7; it was 1.3 for the glassy state at low temperature (-77 0 C). Double bonds were common in the crosslinked products, especially after liquid-phase irradiation. The probability of chain scission was estimated as being negligible, though a small number of chain-scission products (which were products of scission at chain-ends or side chains) were observed by gas analysis. (author)

  8. Mathematical modeling of the mixing zone for getting bimetallic compound

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Stanislav L. [Institute of Applied Mechanics, Ural Branch, Izhevsk (Russian Federation)

    2011-07-01

    A mathematical model of the formation of atomic bonds in metals and alloys, based on the electrostatic interaction between the outer electron shells of atoms of chemical elements. Key words: mathematical model, the interatomic bonds, the electron shell of atoms, the potential, the electron density, bimetallic compound.

  9. 40 CFR 721.3100 - Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Oligomeric silicic acid ester compound with a hy-droxyl-al-kyla-mine. 721.3100 Section 721.3100 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.3100 Oligomeric silicic acid ester compound with a...

  10. Three sesquiterpene compounds biosynthesised from artemisinic acid using suspension-cultured cells of Averrhoa carambola (Oxalidaceae).

    Science.gov (United States)

    Yang, Li; Zhu, Jianhua; Song, Liyan; Shi, Xiaojian; Li, Xingyi; Yu, Rongmin

    2012-01-01

    A new sesquiterpene glycoside, artemisinic acid 3-β-O-β-D-glucopyranoside (3, 31.24%) and other two biotransformation products, 3-β-hydroxyartemisinic acid (2, 36.69%) and 3-β-hydroxyartemisinic acid β-D-glucopyranosyl ester (4, 7.03%), were biosynthesised after artemisinic acid (1) was administered to the cultured cells of Averrhoa carambola. The three biotransformation products were obtained for the first time by using the suspension-cultured cells of A. carambola as a new biocatalyst system, and their structures were identified on the basis of the physico-chemical properties, NMR and mass spectral analyses. The results indicate that the cultured cells of A. carambola have the abilities to hydroxylate and glycosylate sesquiterpene compounds in a regio- and stereoselective manner. Furthermore, the anti-tumour activity of compounds 3 and 4 was evaluated against K562 and HeLa cell lines. Compound 4 showed strong activity against HeLa cell line, with the IC₅₀ value of 0.56 µmol mL⁻¹.

  11. Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

    Science.gov (United States)

    Le Lay, Céline; Coton, Emmanuel; Le Blay, Gwenaëlle; Chobert, Jean-Marc; Haertlé, Thomas; Choiset, Yvan; Van Long, Nicolas Nguyen; Meslet-Cladière, Laurence; Mounier, Jérôme

    2016-12-19

    Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al., 2016), an extensive screening performed both in vitro and in situ allowed for the selection of bacteria exhibiting an antifungal activity. In the present study, active supernatants against Penicillium corylophilum and Aspergillus niger were analyzed to identify and quantify the antifungal compounds associated with the observed activity. Supernatant treatments (pH neutralization, heating and addition of proteinase K) suggested that organic acids played the most important role in the antifungal activity of each tested supernatant. Different methods (HPLC, mass spectrometry, colorimetric and enzymatic assays) were then applied to analyze the supernatants and it was shown that the main antifungal compounds corresponded to lactic, acetic and propionic acids, ethanol and hydrogen peroxide, as well as other compounds present at low levels such as phenyllactic, hydroxyphenyllactic, azelaic and caproic acids. Based on these results, various combinations of the identified compounds were used to evaluate their effect on conidial germination and fungal growth of P. corylophilum and Eurotium repens. Some combinations presented the same activity than the bacterial culture supernatant thus confirming the involvement of the identified molecules in the antifungal activity. The obtained results suggested that acetic acid was mainly responsible for the antifungal activity against P. corylophilum and played an important role in E. repens inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    Science.gov (United States)

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1992-01-01

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  13. Influence of combined use of selenious acid and SH compounds in parenteral preparations

    Energy Technology Data Exchange (ETDEWEB)

    Terada, A. [St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Public Health]|[St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Pharmacy; Yoshida, M. [St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Chemistry; Nakada, M.; Nakada, K.; Yamate, N. [St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Surgery; Kobayashi, T. [St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Pharmacy; Yoshida, K. [St. Marianna University School of Medicine, Kawasaki (Japan). Dept. of Public Health

    1997-12-31

    The influence of the combined use of selenious acid and SH compounds (glutathione (GSH) and cysteine (Cys), or ascorbic acid (Asc)) on cultured venous vascular endothelial cells was investigated experimentally. When cultured human umbilical venous vascular endothelial cells were exposed to 10 {mu}M of selenious acid combined with 0.5 mM-GSH or 0.5 mM-Cys, the release rates of [{sup 3}H]-adenine and lactate dehydrogenase (LDH) from cells into the medium increased significantly as compared with after exposure to selenious acid alone, and damage to the vascular endothelial cells was found to be intensified. Addition of 1 {mu}M of selenious acid simultaneously with 0.5 mM-GSH or 0.5 mM-Cys showed no differences in toxicity for the vascular endothelial cells as compared with the addition of selenious acid alone. On the other hand, simultaneous exposure to 10 {mu}M of selenious acid and 1 mM-Asc induced no significant differences in the release rates of [{sup 3}H]-adenine and LDH, and no damage was observed to the vascular endothelial cells. These results suggest that simultaneous addition of selenious acid together with GSH or Cys, which have the SH-group, may cause damage to the vascular endothelial cells. Therefore careful attention is warranted in total parenteral nutrition. (orig.)

  14. Effects of compound amino acids capsule on the immunological function of naval servicemen

    Directory of Open Access Journals (Sweden)

    Hai-zhong ZHONG

    2012-01-01

    Full Text Available Objective  To investigate the effects of the compound amino acids capsule on the immunological function of the naval servicemen during military activity. Methods  The subjects included 100 officers and soldiers, whose Modified Fatigue Rating Scale (MFIS scores were >21 points. The participants were randomly divided into two groups, namely, the amino acids capsule group and placebo group (n=50. Under the condition of military operations, either amino acids capsule (8 kinds of essential amino acids and 11 kinds of vitamins were contained or placebo capsule was given for 14 days continuously. The humoral immune indices, i.e., IgG, IgA, IgM, and complements C3 and C4, were measured with immunoturbidimetry. The percentage of peripheral blood CD subsets was measured using flow cytometry on the first day and 14th day. Results  The levels of IgG, IgM, and complement C3 in the capsule group were significantly higher on the 14th day than on the first day (P+CD4+ T lymphocytes and CD3-CD19+ B lymphocytes in the capsule group on the 14th day were higher than those on the first day, whereas the CD3-CD56+ NK lymphocytes decreased significantly (PConclusion  Compound amino acids capsule can improve the humoral and cellular immunological function of naval servicemen.

  15. Chemical composition, fatty acid profile and bioactive compounds of guava seeds (Psidium guajava L.

    Directory of Open Access Journals (Sweden)

    Ana Maria Athayde Uchôa-thomaz

    2014-09-01

    Full Text Available This study aimed to characterize the chemical composition, determine the fatty acid profile, and quantify the bioactive compounds present in guava seed powder (Psidium guajava L.. The powder resulted from seeds obtained from guava pulp processing. The agro-industrial seeds from red guava cv. paluma were used, and they were donated by a frozen pulp fruit manufacturer. They contain varying amounts of macronutrients and micronutrients, with a high content of total dietary fiber (63.94 g/100g, protein (11.19 g/100g, iron (13.8 mg/100g, zinc (3.31 mg/100g, and reduced calorie content (182 kcal/100g. Their lipid profile showed a predominance of unsaturated fatty acids (87.06%, especially linoleic acid (n6 and oleic acid (n9. The powder obtained contained significant amounts of bioactive compounds such as ascorbic acid (87.44 mg/100g, total carotenoids (1.25 mg/100 g and insoluble dietary fiber (63.55 g/100g. With regard to their microbiological quality, the samples were found suitable for consumption. Based on these results, it can be concluded that the powder produced has favorable attributes for industrial use, and that use of these seeds would be a viable alternative to prevent various diseases and malnutrition in our country and to reduce the environmental impact of agricultural waste.

  16. The catalytic ozonization of model lignin compounds in the presence of Fe(III) ions

    Science.gov (United States)

    Ben'ko, E. M.; Mukovnya, A. V.; Lunin, V. V.

    2007-05-01

    The ozonization of several model lignin compounds (guaiacol, 2,6-dimethoxyphenol, phenol, and vanillin) was studied in acid media in the presence of iron(III) ions. It was found that Fe3+ did not influence the initial rate of the reactions between model phenols and ozone but accelerated the oxidation of intermediate ozonolysis products. The metal concentration dependences of the total ozone consumption and effective rate constants of catalytic reaction stages were determined. Data on reactions in the presence of oxalic acid as a competing chelate ligand showed that complex formation with Fe3+ was the principal factor that accelerated the ozonolysis of model phenols at the stage of the oxidation of carboxylic dibasic acids and C2 aldehydes formed as intermediate products.

  17. Bioactive Compounds Derived from the Yeast Metabolism of Aromatic Amino Acids during Alcoholic Fermentation

    Directory of Open Access Journals (Sweden)

    Albert Mas

    2014-01-01

    Full Text Available Metabolites resulting from nitrogen metabolism in yeast are currently found in some fermented beverages such as wine and beer. Their study has recently attracted the attention of researchers. Some metabolites derived from aromatic amino acids are bioactive compounds that can behave as hormones or even mimic their role in humans and may also act as regulators in yeast. Although the metabolic pathways for their formation are well known, the physiological significance is still far from being understood. The understanding of this relevance will be a key element in managing the production of these compounds under controlled conditions, to offer fermented food with specific enrichment in these compounds or even to use the yeast as nutritional complements.

  18. Fate modelling of chemical compounds with incomplete data sets

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, Reinout

    2011-01-01

    Impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. These data are used in multi-media fate and exposure models, to calculate risk levels...... in an approximate way. The idea is that not all data needed in a multi-media fate and exposure model are completely independent and equally important, but that there are physical-chemical and biological relationships between sets of chemical properties. A statistical model is constructed to underpin this assumption...... and other indicators. ERA typically addresses one specific chemical, but in an LCIA, the number of chemicals encountered may be quite high, up to hundreds or thousands. This study explores the development of meta-models, which are supposed to reflect the “true”multi-media fate and exposure model...

  19. Organoboron compounds as Lewis acid receptors of fluoride ions in polymeric membranes.

    Science.gov (United States)

    Jańczyk, Martyna; Adamczyk-Woźniak, Agnieszka; Sporzyński, Andrzej; Wróblewski, Wojciech

    2012-07-06

    Newly synthesized organoboron compounds - 4-octyloxyphenylboronic acid (OPBA) and pinacol ester of 2,4,6-trifluorophenylboronic acid (PE-PBA) - were applied as Lewis acid receptors of fluoride anions. Despite enhanced selectivity, the polymer membrane electrodes containing the lipophilic receptor OPBA exhibited non-Nernstian slopes of the responses toward fluoride ions in acidic conditions. Such behavior was explained by the lability of the B-O bond in the boronic acids, and the OH(-)/F(-) exchange at higher fluoride content in the sample solution. In consequence, the stoichiometry of the OPBA-fluoride complexes in the membrane could vary during the calibration, changing the equilibrium concentration of the primary anion in membrane and providing super-Nernstian responses. The proposed mechanism was supported by (19)F NMR studies, which indicated that the fluoride complexation proceeds more effectively in acidic solution leading mainly to PhBF(3)(-) species. Finally, the performances of the membranes based on the phenylboronic acid pinacol ester, with a more stable B-O bond, were tested. As it was expected, Nernstian fluoride responses were recorded for such membranes with worsened fluoride selectivity. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Impact of Roasting on Fatty Acids, Tocopherols, Phytosterols, and Phenolic Compounds Present in Plukenetia huayllabambana Seed

    Directory of Open Access Journals (Sweden)

    Rosana Chirinos

    2016-01-01

    Full Text Available The effect of roasting of Plukenetia huayllabambana seeds on the fatty acids, tocopherols, phytosterols, and phenolic compounds was evaluated. Additionally, the oxidative stability of the seed during roasting was evaluated through free fatty acids, peroxide, and p-anisidine values in the seed oil. Roasting conditions corresponded to 100, 120, 140, and 160°C for 10, 20, and 30 min, respectively. Results indicate that roasting temperatures higher than 120°C significantly affect the content of the studied components. The values of acidity, peroxide, and p-anisidine in the sacha inchi oil from roasted seeds increased during roasting. The treatment of 100°C for 10 min successfully maintained the evaluated bioactive compounds in the seed and quality of the oil, while guaranteeing a higher extraction yield. Our results indicate that P. huayllabambana seed should be roasted at temperatures not higher than 100°C for 10 min to obtain snacks with high levels of bioactive compounds and with high oxidative stability.

  1. Laccase-mediator catalyzed conversion of model lignin compounds

    Science.gov (United States)

    Laccases play an important role in the biological breakdown of lignin and have great potential in the deconstruction of lignocellulosic feedstocks. We examined a variety of laccases, both commercially prepared and crude extracts, for their ability to oxidize three model lignol compounds (p-coumaryl...

  2. Photoacidic and Photobasic Behavior of Transition Metal Compounds with Carboxylic Acid Group(s)

    Energy Technology Data Exchange (ETDEWEB)

    O’Donnell, Ryan M. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Sampaio, Renato N. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Li, Guocan [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Johansson, Patrik G. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Ward, Cassandra L. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States; Meyer, Gerald J. [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States

    2016-03-10

    Excited state proton transfer studies of six Ru polypyridyl compounds with carboxylic acid/carboxylate group(s) revealed that some were photoacids and some were photobases. The compounds [RuII(btfmb)2(LL)]2+, [RuII(dtb)2(LL)]2+, and [RuII(bpy)2(LL)]2+, where bpy is 2,2'-bipyridine, btfmb is 4,4'-(CF3)2-bpy, and dtb is 4,4'-((CH3)3C)2-bpy, and LL is either dcb = 4,4'-(CO2H)2-bpy or mcb = 4-(CO2H),4'-(CO2Et)-2,2'-bpy, were synthesized and characterized. The compounds exhibited intense metal-to-ligand charge-transfer (MLCT) absorption bands in the visible region and room temperature photoluminescence (PL) with long τ > 100 ns excited state lifetimes. The mcb compounds had very similar ground state pKa’s of 2.31 ± 0.07, and their characterization enabled accurate determination of the two pKa values for the commonly utilized dcb ligand, pKa1 = 2.1 ± 0.1 and pKa2 = 3.0 ± 0.2. Compounds with the btfmb ligand were photoacidic, and the other compounds were photobasic. Transient absorption spectra indicated that btfmb compounds displayed a [RuIII(btfmb–)L2]2+* localized excited state and a [RuIII(dcb–)L2]2+* formulation for all the other excited states. Time dependent PL spectral shifts provided the first kinetic data for excited state proton transfer in a transition metal compound. PL titrations, thermochemical cycles, and kinetic analysis (for the mcb compounds) provided self-consistent pKa* values. The ability to make a single ionizable group photobasic or photoacidic through ligand design was unprecedented and was understood based on the orientation of the lowest-lying MLCT excited state dipole relative to the ligand that contained the carboxylic acid group(s).

  3. Studies of the radioprotective properties of nicotinyl compounds, aspartic acid, glutamic acid and methionine

    International Nuclear Information System (INIS)

    Itzel-Kietzmann, V.M.

    1986-01-01

    Radioprotective properties of sodium salts of nicotinyl aspartic acid, nicotinyl methionyl aspartic acid and nicotinyl glutamic acid were tested in mice (NMRI). Experimental animals were irradiated by rayage (9,5 Gy). Parameters were: survival rate, peritoneal fluid cell count, weight and DNA concentration of spleen, hepatic DNA polymerase activity and rate of protein synthesis, lactate dehydrogenase activity in serum, maltase, sucrase and leucine aminopeptidase activitiy in duodenum and jejunum. Following results were obtained: 1. There was no significant difference in survival rate of treated and untreated animals. In treated animals only a short prolongation of survival time was observed. 2. After irradiation a quick reduction of splenic weight and DNA concentration was measured. 3. A reduction of DNA polymerase activity in liver was observed in treated and untreated mice. The rate of hepatic protein synthesis was similar in all animals. A final decrease was observed. 4. Variable activities of maltase, sucrase and leucine aminopeptidase activity in duodenum and jejunum indicated no radioprotective effect of tested substances. In conclusion of these results the tested substances show no significant radioprotective properties. (orig.) [de

  4. QSAR modeling and chemical space analysis of antimalarial compounds

    Science.gov (United States)

    Sidorov, Pavel; Viira, Birgit; Davioud-Charvet, Elisabeth; Maran, Uko; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2017-05-01

    Generative topographic mapping (GTM) has been used to visualize and analyze the chemical space of antimalarial compounds as well as to build predictive models linking structure of molecules with their antimalarial activity. For this, a database, including 3000 molecules tested in one or several of 17 anti- Plasmodium activity assessment protocols, has been compiled by assembling experimental data from in-house and ChEMBL databases. GTM classification models built on subsets corresponding to individual bioassays perform similarly to the earlier reported SVM models. Zones preferentially populated by active and inactive molecules, respectively, clearly emerge in the class landscapes supported by the GTM model. Their analysis resulted in identification of privileged structural motifs of potential antimalarial compounds. Projection of marketed antimalarial drugs on this map allowed us to delineate several areas in the chemical space corresponding to different mechanisms of antimalarial activity. This helped us to make a suggestion about the mode of action of the molecules populating these zones.

  5. Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, A.L.C.S. do; Caires, F.J., E-mail: caires.flavio@yahoo.com.br; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

    2014-01-10

    Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L){sub 2}·nH{sub 2}O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, Co{sub 3}O{sub 4}, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.

  6. Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

    International Nuclear Information System (INIS)

    Nascimento, A.L.C.S. do; Caires, F.J.; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

    2014-01-01

    Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L) 2 ·nH 2 O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn 3 O 4 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds

  7. The nested-doorway model of multistep compound processes

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1982-05-01

    The multistep compound contribution to preequilibrium reaction are discussed within the nested-doorway model. Emphasis is placed on the generalized cross-section auto-correlation function. Several of the more widely used concepts in the conventional, one-class, statistical analysis are discussed and generalized to the multiclass case. A summary of the formal results of the nested-doorway model, obtained within Feshbach's projection operator theory is given. (Author) [pt

  8. Modeling the influence of organic acids on soil weathering

    Science.gov (United States)

    Lawrence, Corey R.; Harden, Jennifer W.; Maher, Kate

    2014-01-01

    Biological inputs and organic matter cycling have long been regarded as important factors in the physical and chemical development of soils. In particular, the extent to which low molecular weight organic acids, such as oxalate, influence geochemical reactions has been widely studied. Although the effects of organic acids are diverse, there is strong evidence that organic acids accelerate the dissolution of some minerals. However, the influence of organic acids at the field-scale and over the timescales of soil development has not been evaluated in detail. In this study, a reactive-transport model of soil chemical weathering and pedogenic development was used to quantify the extent to which organic acid cycling controls mineral dissolution rates and long-term patterns of chemical weathering. Specifically, oxalic acid was added to simulations of soil development to investigate a well-studied chronosequence of soils near Santa Cruz, CA. The model formulation includes organic acid input, transport, decomposition, organic-metal aqueous complexation and mineral surface complexation in various combinations. Results suggest that although organic acid reactions accelerate mineral dissolution rates near the soil surface, the net response is an overall decrease in chemical weathering. Model results demonstrate the importance of organic acid input concentrations, fluid flow, decomposition and secondary mineral precipitation rates on the evolution of mineral weathering fronts. In particular, model soil profile evolution is sensitive to kaolinite precipitation and oxalate decomposition rates. The soil profile-scale modeling presented here provides insights into the influence of organic carbon cycling on soil weathering and pedogenesis and supports the need for further field-scale measurements of the flux and speciation of reactive organic compounds.

  9. Desalination of fish sauce by electrodialysis: effect on selected aroma compounds and amino acid compositions.

    Science.gov (United States)

    Chindapan, Nathamol; Devahastin, Sakamon; Chiewchan, Naphaporn; Sablani, Shyam S

    2011-09-01

    Fish sauce is an ingredient that exhibits unique flavor and is widely used by people in Southeast Asia. Fish sauce, however, contains a significant amount of salt (sodium chloride). Recently, electrodialysis (ED) has been successfully applied to reduce salt in fish sauce; however, no information is available on the effect of ED on changes in compounds providing aroma and taste of ED-treated fish sauce. The selected aroma compounds, amino acids, and sensory quality of the ED-treated fish sauce with various salt concentrations were then analyzed. The amounts of trimethylamine, 2,6-dimethylpyrazine, phenols, and all carboxylic acids except for hexanoic acid significantly decreased, whereas benzaldehyde increased significantly when the salt removal level was higher. The amounts of all amino acids decreased with the increased salt removal level. Significant difference in flavor and saltiness intensity among ED-treated fish sauce with various salt concentrations, as assessed by a discriminative test, were observed. Information obtained in this work can serve as a guideline for optimization of a process to produce low-sodium fish sauce by ED. It also forms a basis for further in-depth sensory analysis of low-sodium fish sauce. © 2011 Institute of Food Technologists®

  10. Modeling of RO/NF membrane rejections of PhACs and organic compounds: a statistical analysis

    Directory of Open Access Journals (Sweden)

    G. Amy

    2008-07-01

    Full Text Available Rejections of pharmaceutical compounds (Ibuprofen, Diclofenac, Clofibric acid, Naproxen, Primidone, Phenacetin and organic compounds (Dichloroacetic acid, Trichloroacetic acid, Chloroform, Bromoform, Trichloroethene, Perchloroethene, Carbontetrachloride, Carbontetrabromide by NF (Filmtec, Saehan and RO (Filmtec, Saehan, Toray, Koch membranes were studied. Chloroform presented the lowest rejection due to small molar volume, equivalent width and length. Diclofenac and Primidone showed high rejections related to high molar volume and length. Dichloroacetic acid and Trichloroacetic acid presented good rejections caused by charge exclusion instead of steric hindrance mechanism influencing rejection. Bromoform and Trichloroethene showed low rejections due to small length and equivalent width. Carbontetrabromide, Perchloroethene and Carbontetrachloride with higher equivalent width than BF and TCE presented better rejections. A qualitative analysis of variables using Principal Component Analysis was successfully implemented for reduction of physical-chemical compound properties that influence membrane rejection of PhACs and organic compounds. Properties such as dipole moment, molar volume, hydrophobicity/hydrophilicity, molecular length and equivalent width were found to be important descriptors for simulation of membrane rejection. For membranes used in the experiments, we may conclude that charge repulsion was an important mechanism of rejection for ionic compounds. After analysis with Multiple Linear Regression, we also may conclude that membrane rejection of neutral compounds was well predicted by molar volume, length, equivalent width, hydrophobicity/hydrophilicity and dipole moment. Molecular weight was a poor descriptor variable for rejection modelling. We were able to provide acceptable statistical significance for important results.

  11. A study on superoxide dismutase activity of some model compounds.

    Science.gov (United States)

    Liao, Z; Liu, W; Liu, J; Jiang, Y; Shi, J; Liu, C

    1994-08-15

    The synthesis and characteristics of a binuclear ligand N,N,N',N'-tetrakis (2'-benzimidazolyl methyl)-1,4-diethylene amino glycol ether (EGTB) and its series of coordination compounds containing copper(II), iron(III), and manganese(II) with and without exogenous bridging ligand which was imidazolate ion (Im-), bipyridine (bpy), or 1,10-phenanthroline (phen) are reported. Depending on the redox potentials by cyclic voltammetry, the coordination compounds can act as catalysts for the dismutation of superoxide radicals (O2-). The detection of the rate constant of the reaction of superoxide ion with nitroblue tetrazolium (NBT) which is inhibited by superoxide dismutase (SOD) and its model compounds of the EGTB system has been performed by a modified illumination method. The rate constants kQ of the catalytic dismutation have been obtained.

  12. The chromatographic behavior of arsenic compounds on anion exchange columns with binary organic acids as mobile phases

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, J.; Goessler, W.; Kosmus, W. [Graz Univ. (Austria). Inst. fuer Analytische Chemie

    1998-03-01

    Identification and quantification of arsenic compounds was performed with high-performance liquid chromatography (HPLC) and flame atomic absorption spectrometry (FAAS) as element-specific detector. Arsenous acid, methylarsonic acid, dimethylarsinic acid, arsenic acid, arsenobetaine, and arsenocholine were separated on two anion-exchange columns (Synchropak Q 300 and PRP-X 100) with different binary organic acids as mobile phases. The influence of chromatographic parameters, such as pH and the concentration of the mobile phase were investigated. An unusual chromatographic behavior of arsenous acid was observed when tartaric acid was used as mobile phase. (orig.)

  13. Gaschromatographic and mass spectroscopic investigations of tall oil rosin acids and diterpenioc compounds and modified diterpene acids

    International Nuclear Information System (INIS)

    Mayr, M.

    1984-12-01

    Diterpene resin acids are important constituents of the coniferous wood. The composition of these nonvolatile extractives have been studied by a number of investigations; both naturally occurring resins (oleoresin) and distillation products of the alkaline sulfate pulping process (tall oil) were analyzed. These mixtures find important uses in chemical intermediates, paper sizes, ester gums, coatings and numerous other applications. Owing to the more ameliorate physical properties a major part of tall oil resin acids is chemically modified and is used in intermediate chemicals. Such modifications are the disproportionation in the presence of certain catalysts and the formation of Diels-Alder adducts. The present study was undertaken to obtain detailed information of the overall composition of diterpenoid compounds and to achieve a separation of the complex natural and tall oil mixtures using high resolution glass capillary columns. Furthermore, one objective was to characterize the identified diterpene compounds and Diels-Alder adducts by relative retention values. Additionally the presence of some major adduct components in the modified samples was checked by comparison with pure specimens, independently synthesized or purified by crystallization and the mechanism of the Diels-Alder reaction was investigated. A compilation of the mass spectra of the substances detected in the different samples closes this work. (Author)

  14. Utilization of Volatile Fatty Acids from Microalgae for the Production of High Added Value Compounds

    Directory of Open Access Journals (Sweden)

    Angelina Chalima

    2017-10-01

    Full Text Available Volatile Fatty Acids (VFA are small organic compounds that have attracted much attention lately, due to their use as a carbon source for microorganisms involved in the production of bioactive compounds, biodegradable materials and energy. Low cost production of VFA from different types of waste streams can occur via dark fermentation, offering a promising approach for the production of biofuels and biochemicals with simultaneous reduction of waste volume. VFA can be subsequently utilized in fermentation processes and efficiently transformed into bioactive compounds that can be used in the food and nutraceutical industry for the development of functional foods with scientifically sustained claims. Microalgae are oleaginous microorganisms that are able to grow in heterotrophic cultures supported by VFA as a carbon source and accumulate high amounts of valuable products, such as omega-3 fatty acids and exopolysaccharides. This article reviews the different types of waste streams in concert with their potential to produce VFA, the possible factors that affect the VFA production process and the utilization of the resulting VFA in microalgae fermentation processes. The biology of VFA utilization, the potential products and the downstream processes are discussed in detail.

  15. Syntheses, Characterization, Resolution, and Biological Studies of Coordination Compounds of Aspartic Acid and Glycine

    Science.gov (United States)

    Akinkunmi, Ezekiel; Ojo, Isaac; Adebajo, Clement; Isabirye, David

    2017-01-01

    Enantiomerically enriched coordination compounds of aspartic acid and racemic mixtures of coordination compounds of glycine metal-ligand ratio 1 : 3 were synthesized and characterized using infrared and UV-Vis spectrophotometric techniques and magnetic susceptibility measurements. Five of the complexes were resolved using (+)-cis-dichlorobis(ethylenediamine)cobalt(III) chloride, (+)-bis(glycinato)(1,10-phenanthroline)cobalt(III) chloride, and (+)-tris(1,10-phenanthroline)nickel(II) chloride as resolving agents. The antimicrobial and cytotoxic activities of these complexes were then determined. The results obtained indicated that aspartic acid and glycine coordinated in a bidentate fashion. The enantiomeric purity of the compounds was in the range of 22.10–32.10%, with (+)-cis-dichlorobis(ethylenediamine)cobalt(III) complex as the more efficient resolving agent. The resolved complexes exhibited better activity in some cases compared to the parent complexes for both biological activities. It was therefore inferred that although the increase in the lipophilicity of the complexes may assist in the permeability of the complexes through the cell membrane of the pathogens, the enantiomeric purity of the complexes is also of importance in their activity as antimicrobial and cytotoxic agents. PMID:28293149

  16. Whole body acid-base modeling revisited.

    Science.gov (United States)

    Ring, Troels; Nielsen, Søren

    2017-04-01

    The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis. Copyright © 2017 the American Physiological Society.

  17. Adsorption of selected pharmaceuticals and an endocrine disrupting compound by granular activated carbon. 2. Model prediction

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Z.; Peldszus, S.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). NSERC Chair in Water Treatment

    2009-03-01

    The adsorption of two representative pharmaceutically active compounds (PhACs) naproxen and carbamazepine and one endocrine disrupting compound (EDC) nonylphenol was studied in pilot-scale granular activated carbon (GAC) adsorbers using post-sedimentation (PS) water from a full-scale drinking water treatment plant. The GAC adsorbents were coal-based Calgon Filtrasorb 400 and coconut shell-based PICA CTIF TE. Acidic naproxen broke through fastest while nonylphenol was removed best, which was consistent with the degree to which fouling affected compound removals. Model predictions and experimental data were generally in good agreement for all three compounds, which demonstrated the effectiveness and robustness of the pore and surface diffusion model (PSDM) used in combination with the time-variable parameter approach for predicting removals at environmentally relevant concentrations (i.e., ng/L range). Sensitivity analyses suggested that accurate determination of film diffusion coefficients was critical for predicting breakthrough for naproxen and carbamazepine, in particular when high removals are targeted. Model simulations demonstrated that GAC carbon usage rates (CURs) for naproxen were substantially influenced by the empty bed contact time (EBCT) at the investigated conditions. Model-based comparisons between GAC CURs and minimum CURs for powdered activated carbon (PAC) applications suggested that PAC would be most appropriate for achieving 90% removal of naproxen, whereas GAC would be more suitable for nonylphenol. 25 refs., 4 figs., 1 tab.

  18. Organic compounds containing methoxy and cyanoacrylic acid: Synthesis, characterization, crystal structures, and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Khalaji, A. D., E-mail: alidkhalaji@yahoo.com [Golestan University, Department of Chemistry, Faculty of Science (Iran, Islamic Republic of); Maddahi, E. [Iran University of Science & Technology, Ms.C Educated, Department of Chemistry (Iran, Islamic Republic of); Dusek, M.; Fejfarova, K. [Institute of Physics of the ASCR, v.v.i. (Czech Republic); Chow, T. J. [Academia Sinica, Institute of Chemistry (China)

    2015-12-15

    Metal-free organic compounds 24-SC ((E)-2-cyano-3-(2,4-dimethoxyphenyl)acrylic acid) and 34-SC ((E)-2-cyano-3-(3,4-dimethoxyphenyl)acrylic acid), containing methoxy groups as a donor and the acrylic acid as an acceptor were synthesized and characterized by CHN, FT-IR, UV-Vis, {sup 1}H-NMR and single crystal X-ray diffraction and used as photosensitizers for the application of dye-sensitized solar cells (DSSC). The sensitizing characteristics of them were evaluated. Both compounds contain the natural molecule, its anionic form and the piperidinium cation and they differ by number of these molecules in the asymmetric unit. To get further insight into the effect of molecular structure on the performance of DSSC, their geometry and energies of HOMO and LUMO were optimized by density functional theory calculation at the B3LYP/6-31G(d) level with Gaussian 03. Overall conversion efficiencies of 0.78 under full sunlight irradiation are obtained for DSSCs based on the new metal-free organic dyes 24-SC and 34-SC.

  19. Effects of high pressure processing on fatty acid composition and volatile compounds in Korean native black goat meat.

    Science.gov (United States)

    Kang, Geunho; Cho, Soohyun; Seong, Pilnam; Park, Beomyoung; Kim, Sangwoo; Kim, Donghun; Kim, Youngjun; Kang, Sunmun; Park, Kyoungmi

    2013-08-01

    This study investigated the effects of high pressure processing (HPP) on fatty acid composition and volatile compounds in Korean native black goat (KNBG) meat. Fatty acid content in KNBG meat was not significantly (p > 0.05) different among the control goats and those subjected HPP. The 9,12-octadecadienoic acid and octadecanoic acid, well-known causes of off-flavors, were detected from meat of some KNBG. A difference between the control and HPP treatment was observed in the discriminated function analysis using an electronic nose. The results suggest that the volatile compounds in KNBG meat were affected by HPP.

  20. Immobilization of kojic acid in ZnAl-hydrotalcite like compounds

    Science.gov (United States)

    Ambrogi, Valeria; Perioli, Luana; Nocchetti, Morena; Latterini, Loredana; Pagano, Cinzia; Massetti, Elena; Rossi, Carlo

    2012-01-01

    Kojic acid (KOJ) is a melanin synthesis inhibitor widely used as skin lightening agent in topical preparations. Unfortunately it is easily susceptible to photo-oxidation, phenomenon responsible for chemical and organoleptic modifications. The aim of this work was the intercalation of KOJ in hydrotalcite-like compounds (HTlc) in order to stabilize KOJ and to reduce its photolability. Hydrotalcite containing Zn and Al (ZnAl-HTlc) was used as host to obtain the final compound ZnAl-HTlc-KOJ. The intercalation was carried out, after many attempts, by ionic exchange mechanism by means of the strong base EtO- in anhydrous ethanol/dimethylsulfoxide (DMSO) mixture as solvent in order to generate KOJ- anions. The final product was characterized by the X-ray powder diffraction (XRPD), FT-IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis. The intercalated compound was formulated in a siliconic water free self-emulsifying ointment and the in vitro release profile was evaluated. All samples (intercalation compound and its formulation) were submitted also to spectrophotometric assays in order to evaluate the matrix protective effect towards ultraviolet rays.

  1. Photoproduction of hydrogen peroxide in aqueous solution from model compounds for chromophoric dissolved organic matter (CDOM)

    International Nuclear Information System (INIS)

    Clark, Catherine D.; Bruyn, Warren de; Jones, Joshua G.

    2014-01-01

    Highlights: • CDOM produces hydrogen peroxide in sunlit surface waters. • Quinone moieties have been proposed as the photo-active chromophore in CDOM. • Hydrogen peroxide is produced in irradiated aqueous quinone solutions. • Concentrations and production rates are comparable to humic and fulvic acids. • Optical properties post-irradiation were similar to CDOM. - Abstract: To explore whether quinone moieties are important in chromophoric dissolved organic matter (CDOM) photochemistry in natural waters, hydrogen peroxide (H 2 O 2 ) production and associated optical property changes were measured in aqueous solutions irradiated with a Xenon lamp for CDOM model compounds (dihydroquinone, benzoquinone, anthraquinone, napthoquinone, ubiquinone, humic acid HA, fulvic acid FA). All compounds produced H 2 O 2 with concentrations ranging from 15 to 500 μM. Production rates were higher for HA vs. FA (1.32 vs. 0.176 mM h −1 ); values ranged from 6.99 to 0.137 mM h −1 for quinones. Apparent quantum yields (Θ app ; measure of photochemical production efficiency) were higher for HA vs. FA (0.113 vs. 0.016) and ranged from 0.0018 to 0.083 for quinones. Dihydroquinone, the reduced form of benzoquinone, had a higher production rate and efficiency than its oxidized form. Post-irradiation, quinone compounds had absorption spectra similar to HA and FA and 3D-excitation–emission matrix fluorescence spectra (EEMs) with fluorescent peaks in regions associated with CDOM

  2. Ursolic and oleanolic acids as antimicrobial and immunomodulatory compounds for tuberculosis treatment.

    Science.gov (United States)

    Jiménez-Arellanes, Adelina; Luna-Herrera, Julieta; Cornejo-Garrido, Jorge; López-García, Sonia; Castro-Mussot, María Eugenia; Meckes-Fischer, Mariana; Mata-Espinosa, Dulce; Marquina, Brenda; Torres, Javier; Hernández-Pando, Rogelio

    2013-10-07

    New alternatives for the treatment of Tuberculosis (TB) are urgently needed and medicinal plants represent a potential option. Chamaedora tepejilote and Lantana hispida are medicinal plants from Mexico and their hexanic extracts have shown antimycobacterial activity. Bioguided investigation of these extracts showed that the active compounds were ursolic acid (UA) and oleanolic acid (OA). The activity of UA and OA against Mycobacterium tuberculosis H37Rv, four monoresistant strains, and two drug-resistant clinical isolates were determined by MABA test. The intracellular activity of UA and OA against M. tuberculosis H37Rv and a MDR clinical isolate were evaluated in a macrophage cell line. Finally, the antitubercular activity of UA and OA was tested in BALB/c mice infected with M. tuberculosis H37Rv or a MDR strain, by determining pulmonary bacilli loads, tissue damage by automated histomorphometry, and expression of IFN-γ, TNF-α, and iNOS by quantitative RT-PCR. The in vitro assay showed that the UA/OA mixture has synergistic activity. The intracellular activity of these compounds against M. tuberculosis H37Rv and a MDR clinical isolate in a macrophage cell line showed that both compounds, alone and in combination, were active against intracellular mycobacteria even at low doses. Moreover, when both compounds were used to treat BALB/c mice with TB induced by H37Rv or MDR bacilli, a significant reduction of bacterial loads and pneumonia were observed compared to the control. Interestingly, animals treated with UA and OA showed a higher expression of IFN-γ and TNF-α in their lungs, than control animals. UA and OA showed antimicrobial activity plus an immune-stimulatory effect that permitted the control of experimental pulmonary TB.

  3. Surface characterisation of synthetic coal chars made from model compounds

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Pevida, C.; Rubiera, F.; Palacios, J.M.; Navarrete, R.; Denoyel, R.; Rouquerol, J.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2004-07-01

    Knowledge of surface properties is essential for understanding the reaction mechanisms involved in several coal conversion processes. However, due to the complexity and heterogeneity of coal this is rather difficult and the use of known model compounds could be a valuable tool. Single model compounds have been widely used, but they give a quite simplified picture. In this work a mixture of model compounds in a phenol-formaldehyde matrix was cured in order to create cross-linked structures. The obtained synthetic coal was pyrolysed in a fixed bed reactor, under helium atmosphere. The surface composition of the chars was evaluated by XPS, adsorption gravimetry of water vapour, temperature-programmed desorption and potentiometric titration. Texture was characterised by N{sub 2} and CO{sub 2} adsorption isotherms at 77 and 273 K, respectively, and immersion calorimetry in benzene. The results obtained from the different techniques were contrasted in order to give an overview of the surface properties (chemical and physical) of the samples studied. Chars obtained under the same operating conditions from a high volatile bituminous coal were used as a reference.

  4. Bone targeting compounds for radiotherapy and imaging: *Me(III)-DOTA conjugates of bisphosphonic acid, pamidronic acid and zoledronic acid.

    Science.gov (United States)

    Meckel, M; Bergmann, R; Miederer, M; Roesch, F

    2017-01-01

    Bisphosphonates have a high adsorption on calcified tissues and are commonly used in the treatment of bone disorder diseases. Conjugates of bisphosphonates with macrocyclic chelators open new possibilities in bone targeted radionuclide imaging and therapy. Subsequent to positron emission tomography (PET) examinations utilizing 68 Ga-labelled analogues, endoradiotheraphy with 177 Lu-labelled macrocyclic bisphosphonates may have a great potential in the treatment of painful skeletal metastases. Based on the established pharmaceuticals pamidronate and zoledronate two new DOTA-α-OH-bisphosphonates, DOTA PAM and DOTA ZOL (MM1.MZ) were successfully synthesized. The ligands were labelled with the positron emitting nuclide 68 Ga and the β - emitting nuclide 177 Lu and compared in in vitro studies and in ex vivo biodistribution studies together with small animal PET and single photon emission computed tomography (SPECT) studies against [ 18 F]NaF and a known DOTA-α-H-bisphosphonate conjugate (BPAPD) in healthy Wistar rats. The new DOTA-bisphosphonates can be labelled in high yield of 80 to 95 % in 15 min with post-processed 68 Ga and >98 % with 177 Lu. The tracers showed very low uptake in soft tissue, a fast renal clearance and a high accumulation on bone. The best compound was [ 68 Ga]DOTA ZOL (SUV Femur  = 5.4 ± 0.6) followed by [ 18 F]NaF (SUV Femur  = 4.8 ± 0.2), [ 68 Ga]DOTA PAM (SUV Femur  = 4.5 ± 0.2) and [ 68 Ga]BPAPD (SUV Femur  = 3.2 ± 0.3). [ 177 Lu]DOTA ZOL showed a similar distribution as the diagnostic 68 Ga complex. The 68 Ga labelled compounds showed a promising pharmacokinetics, with similar uptake profile and distribution kinetics. Bone accumulation was highest for [ 68 Ga]DOTA ZOL , which makes this compound probably an interesting bone targeting agent for a therapeutic approach with 177 Lu. The therapeutic compound [ 177 Lu]DOTA ZOL showed a high target-to-background ratio. SPECT experiments showed concordance

  5. THREE DIMENSIONAL CFD MODELLING OF FLOW STRUCTURE IN COMPOUND CHANNELS

    Directory of Open Access Journals (Sweden)

    Usman Ghani

    2010-10-01

    Full Text Available The computational modeling of three dimensional flows in a meandering compound channel has been performed in this research work. The flow calculations are performed by solving 3D steady state continuity and Reynolds averaged Navier-Stokes equations. The turbulence closure is approximated with standard - turbulence model. The model equations are solved numerically with a general purpose software package. A comprehensive validation of the simulated results against the experimental data and a demonstration that the software used in this study has matured enough for investigating practical engineering problems are the major contributions of this paper. The model was initially validated. This was achieved by computing streamwise point velocities at different depths of various sections and depth averaged velocities at three cross sections along the main channel and comparing these results with experimental data. After the validation of the model, predictions were made for different flow parameters including velocity contours at the surface, pressure distribution, turbulence intensity etc. The results gave an overall understanding of these flow variables in meandering channels. The simulation also established the good prediction capability of the standard - turbulence model for flows in compound channels.

  6. Influence of phenolic compounds on the growth and arginine deiminase system in a wine lactic acid bacterium

    Directory of Open Access Journals (Sweden)

    María R. Alberto

    2012-03-01

    Full Text Available The influence of seven phenolic compounds, normally present in wine, on the growth and arginine deiminase system (ADI of Lactobacillus hilgardii X1B, a wine lactic acid bacterium, was established. This system provides energy for bacterial growth and produces citrulline that reacts with ethanol forming the carcinogen ethyl carbamate (EC, found in some wines. The influence of phenolic compounds on bacterial growth was compound dependent. Growth and final pH values increased in presence of arginine. Arginine consumption decreased in presence of protocatechuic and gallic acids (31 and 17%, respectively and increased in presence of quercetin, rutin, catechin and the caffeic and vanillic phenolic acids (between 10 and 13%, respectively. ADI enzyme activities varied in presence of phenolic compounds. Rutin, quercetin and caffeic and vanillic acids stimulated the enzyme arginine deiminase about 37-40%. Amounts of 200 mg/L gallic and protocatechuic acids inhibited the arginine deiminase enzyme between 53 and 100%, respectively. Ornithine transcarbamylase activity was not modified at all concentrations of phenolic compounds. As gallic and protocatechuic acids inhibited the arginine deiminase enzyme that produces citrulline, precursor of EC, these results are important considering the formation of toxic compounds.

  7. The binding of aluminum to mugineic acid and related compounds as studied by potentiometric titration.

    Science.gov (United States)

    Yoshimura, Etsuro; Kohdr, Hicham; Mori, Satoshi; Hider, Robert C

    2011-08-01

    The phytosiderophores, mugineic acid (MA) and epi-hydroxymugineic acid (HMA), together with a related compound, nicotianamine (NA), were investigated for their ability to bind Al(III). Potentiometric titration analysis demonstrated that MA and HMA bind Al(III), in contrast to NA which does not under normal physiological conditions. With MA and HMA, in addition to the Al complex (AlL), the protonated (AlLH) and deprotonated (AlLH(-1)) complexes were identified from an analysis of titration curves, where L denotes the phytosiderophore form in which all the carboxylate functions are ionized. The equilibrium formation constants of the Al(III) phytosiderophore complexes are much smaller than those of the corresponding Fe(III) complexes. The higher selectivity of phytosiderophores for Fe(III) over Al(III) facilitates Fe(III) acquisition in alkaline conditions where free Al(III) levels are higher than free Fe(III) levels.

  8. Tannin structural elucidation and quantitative ³¹P NMR analysis. 1. Model compounds.

    Science.gov (United States)

    Melone, Federica; Saladino, Raffaele; Lange, Heiko; Crestini, Claudia

    2013-10-02

    Tannins and flavonoids are secondary metabolites of plants that display a wide array of biological activities. This peculiarity is related to the inhibition of extracellular enzymes that occurs through the complexation of peptides by tannins. Not only the nature of these interactions, but more fundamentally also the structure of these heterogeneous polyphenolic molecules are not completely clear. This first paper describes the development of a new analytical method for the structural characterization of tannins on the basis of tannin model compounds employing an in situ labeling of all labile H groups (aliphatic OH, phenolic OH, and carboxylic acids) with a phosphorus reagent. The ³¹P NMR analysis of ³¹P-labeled samples allowed the unprecedented quantitative and qualitative structural characterization of hydrolyzable tannins, proanthocyanidins, and catechin tannin model compounds, forming the foundations for the quantitative structural elucidation of a variety of actual tannin samples described in part 2 of this series.

  9. P-matrix in the quark compound bag model

    International Nuclear Information System (INIS)

    Kalashnikova, Yu.S.; Narodetskij, I.M.; Veselov, A.I.

    1983-01-01

    Meaning of the P-matrix analysis is discussed within the quark compound bag (QCB) model. The most general version of this model is considered including the arbitrary coupling between quark and hadronic channels and the arbitrary smearipg of the surface interection region. The behaviour of P-matrix poles as functions of matching radius r,L0 is discussed for r 0 > + . In conclusion are presented the parameters of an illustrative set of NN potentials that has been obtained from the P-matrix fit to experimental data

  10. Formulation, evaluation and bioactive potential of Xylaria primorskensis terpenoid nanoparticles from its major compound xylaranic acid.

    Science.gov (United States)

    Adnan, Mohd; Patel, Mitesh; Reddy, Mandadi Narsimha; Alshammari, Eyad

    2018-01-29

    In recent years, fungi have been shown to produce a plethora of new bioactive secondary metabolites of interest, as new lead structures for medicinal and other pharmacological applications. The present investigation was carried out to study the pharmacological properties of a potent and major bioactive compound: xylaranic acid, which was obtained from Xylaria primorskensis (X. primorskensis) terpenoids in terms of antibacterial activity, antioxidant potential against DPPH & H 2 O 2 radicals and anticancer activity against human lung cancer cells. Due to terpenoid nature, low water solubility and wretched bioavailability, its pharmacological use is limited. To overcome these drawbacks, a novel xylaranic acid silver nanoparticle system (AgNPs) is developed. In addition to improving its solubility and bioavailability, other advantageous pharmacological properties has been evaluated. Furthermore, enhanced anticancer activity of xylaranic acid and its AgNPs due to induced apoptosis were also confirmed by determining the expression levels of apoptosis regulatory genes p53, bcl-2 and caspase-3 via qRT PCR method. This is the first study developing the novel xylaranic acid silver nanoparticle system and enlightening its therapeutic significance with its improved physico-chemical properties and augmented bioactive potential.

  11. Supercritical fluid extraction of uranium and thorium from nitric acid medium using organophosphorous compounds

    Energy Technology Data Exchange (ETDEWEB)

    Pitchaiah, K.C.; Sujatha, K.; Rao, C.V.S. Brahmmananda; Subramaniam, S.; Sivaraman, N.; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2015-06-01

    In recent years, Supercritical Fluid Extraction (SFE) technique has been widely used for the extraction of metal ions. In the present study, extraction of uranium from nitric acid medium was investigated using supercritical carbon dioxide (Sc-CO{sub 2}) containing various organophosphorous compounds such as trialkyl phosphates e.g. tri-iso-amyl phosphate (TiAP), tri-sec-butyl phosphate (TsBP) and tri-n-butyl phosphate (TBP), dialkylalkyl phosphonates, e.g. diamylamyl phosphonate (DAAP) and dibutyl butyl phosphonate (DBBP), dialkyl hydrogen phosphonates, e.g. dioctyl hydrogen phosphonate (DOHP), dioctylphosphineoxide (DOPO), trioctyl phosphine oxide (TOPO), n-octylphenyl N,N-diisobutyl carbamoylmethylphosphine oxide (CMPO) and di-2-ethyl-hexyl phosphoric acid (HDEHP). Some of these ligands have been investigated for the first time in the supercritical phase for the extraction of uranium. The extraction efficiency of uranium was studied with TiAP, DAAP and DBBP as a function of nitric acid concentration; the kinetics of the equilibration period (static extraction) and transportation of the metal complex (dynamic extraction) was investigated. The influence of pressure and temperature on the extraction behaviour of uranium with DAAP was studied from 4 N HNO{sub 3}. The extraction efficiency of uranium from 4 N nitric acid medium was found to increase in the order of phosphates < phosphonates < HDEHP < TOPO < CMPO. In the case of phosphates and phosphonates, the maximum extraction of uranium was found to be from 4 N HNO{sub 3} medium. The acidic extractants, HDEHP and DOHP showed relatively higher extraction at lower acidities. The relative extraction of uranium and thorium from their mixture was also examined using Sc-CO{sub 2} containing phosphates, phosphonates and TOPO. The ligand, TsBP provided better fractionation between uranium and thorium compared to trialkyl phosphates, dialkyl alkyl phosphonates and TOPO.

  12. Retention prediction and hydrophobicity estimation of weak acidic compounds by reversed-phase liquid chromatography using acetic and perchloric acids as ion suppressors.

    Science.gov (United States)

    Han, Shu-ying; Ming, Xin; Qi, Zheng-chun; Sheng, Dong; Lian, Hong-zhen

    2010-11-01

    Simple acids are usually applied to suppress the ionization of weakly ionizable acidic analytes in reversed-phase liquid chromatography. The purpose of this study is to investigate the retention behavior of various weak acidic compounds (monoprotic, diprotic, triprotic, and tetraprotic acids) using acetic or perchloric acid as ion suppressor in a binary hydroorganic mobile phase. The apparent n-octanol-water partition coefficient (K(ow)") was proposed to calibrate the n-octanol-water partition coefficient (K(ow)) of weak acidic compound. LogK(ow)" was found to have a better linear correlation with logk(w), the logarithm of the retention factor obtained by extrapolating to neat aqueous fraction of the mobile phase, for all weakly ionizable acidic compounds. This straightforward relationship offers a potential medium for direct measurement of K(ow) data of weak acidic analytes and can be used to predict retention behavior of these compounds in the ion suppression reversed-phase liquid chromatographic mode.

  13. Fermentation of liquid coproducts and liquid compound diets: Part 2. Effects on pH, acid-binding capacity, organic acids and ethanol during a 6-day period

    NARCIS (Netherlands)

    Scholten, R.H.J.; Rijnen, M.M.J.A.; Schrama, J.W.; Boer, H.; Peet-Schwering, van der C.M.C.; Hartog, den L.A.; Vesseur, P.C.

    2001-01-01

    The effects of a 6-day storage period on changes in pH, acid-binding capacity, level of organic acids and ethanol of three liquid coproducts [liquid wheat starch (LWS), mashed potato steam peel (PSP) and cheese whey (CW)] and two liquid compound diets [liquid grower diet (LGD) and liquid finisher

  14. Biosynthesis of gallic and ellagic acids with 14C-labeled compounds in Acer and Rhus leaves

    International Nuclear Information System (INIS)

    Ishikura, Nariyuki; Hayashida, Shunzo; Tazaki, Kiyoshi

    1984-01-01

    The biosynthetic pathway for gallic and ellagic acids in young, mature and autumn leaves of Acer buergerianum and Rhus succedanea was examined by tracer experiments, and also by isotope competition, with D-shikimic acid- 14 C, L-phenylalanine-U- 14 C, L-phenyllactic acid-U- 14 C, gallic acid-G- 14 C and their unlabeled compounds. In young leaves of both plants, the incorporation rate of labeled shikimic acid into gallic acid was significantly higher than that of labeled phenylalanine, whereas in the mature and autumn leaves the latter was a good precursor rather than the former for the gallic acid biosynthesis. Therefore, two pathways for gallic acid formation, through β-oxidation of phenylpropanoid and through dehydrogenation of shikimic acid, could be operating in Acer and Rhus leaves, and the preferential pathway is altered by leaf age. In both plants, the incorporation rate of labeled phenyllactic acid during a 24 hr metabolic period was almost the same as that of labeled phenylalanine. The incorporation of D-shikimic acid-G- 14 C, L-phenylalanine-U- 14 C and L-phenyllactic acid-U- 14 C into ellagic acid was very similar to the case of the radioactive gallic acid formation. Furthermore, regardless of the presence of unlabeled shikimic acid and/or phenylalanine, incorporation of the radioactivity of labeled gallic acid into ellagic acid occurred at a very high rate, suggesting the reciprocal radical reaction of gallic acid for the ellagic acid formation. The incorporation of labeled compounds into ellagitannins was also examined and their biosynthesis discussed further. (author)

  15. Activation of Multiple Antibiotic Resistance in Uropathogenic Escherichia coli Strains by Aryloxoalcanoic Acid Compounds

    Science.gov (United States)

    Balagué, Claudia; Véscovi, Eleonora García

    2001-01-01

    Clofibric and ethacrynic acids are prototypical pharmacological agents administered in the treatment of hypertrigliceridemia and as a diuretic agent, respectively. They share with 2,4-dichlorophenoxyacetic acid (the widely used herbicide known as 2,4-D) a chlorinated phenoxy structural moiety. These aryloxoalcanoic agents (AOAs) are mainly excreted by the renal route as unaltered or conjugated active compounds. The relatedness of these agents at the structural level and their potential effect on therapeutically treated or occupationally exposed individuals who are simultaneously undergoing a bacterial urinary tract infection led us to analyze their action on uropathogenic, clinically isolated Escherichia coli strains. We found that exposure to these compounds increases the bacterial resistance to an ample variety of antibiotics in clinical isolates of both uropathogenic and nonpathogenic E. coli strains. We demonstrate that the AOAs induce an alteration of the bacterial outer membrane permeability properties by the repression of the major porin OmpF in a micF-dependent process. Furthermore, we establish that the antibiotic resistance phenotype is primarily due to the induction of the MarRAB regulatory system by the AOAs, while other regulatory pathways that also converge into micF modulation (OmpR/EnvZ, SoxRS, and Lrp) remained unaltered. The fact that AOAs give rise to uropathogenic strains with a diminished susceptibility to antimicrobials highlights the impact of frequently underestimated or ignored collateral effects of chemical agents. PMID:11353631

  16. Identification of didecyldimethylammonium salts and salicylic acid as antimicrobial compounds in commercial fermented radish kimchi.

    Science.gov (United States)

    Li, Jing; Chaytor, Jennifer L; Findlay, Brandon; McMullen, Lynn M; Smith, David C; Vederas, John C

    2015-03-25

    Daikon radish (Raphanus sativus) fermented with lactic acid bacteria, especially Leuconostoc or Lactobacillus spp., can be used to make kimchi, a traditional Korean fermented vegetable. Commercial Leuconostoc/radish root ferment filtrates are claimed to have broad spectrum antimicrobial activity. Leuconostoc kimchii fermentation products are patented as preservatives for cosmetics, and certain strains of this organism are reported to produce antimicrobial peptides (bacteriocins). We examined the antimicrobial agents in commercial Leuconostoc/radish root ferment filtrates. Both activity-guided fractionation with Amberlite XAD-16 and direct extraction with ethyl acetate gave salicylic acid as the primary agent with activity against Gram-negative bacteria. Further analysis of the ethyl acetate extract revealed that a didecyldimethylammonium salt was responsible for the Gram-positive activity. The structures of these compounds were confirmed by a combination of (1)H- and (13)C NMR, high-performance liquid chromatography, high-resolution mass spectrometry, and tandem mass spectrometry analyses. Radiocarbon dating indicates that neither compound is a fermentation product. No antimicrobial peptides were detected.

  17. Fatty acid composition of intramuscular fat and odour-active compounds of lamb commercialized in northern Spain.

    Science.gov (United States)

    Bravo-Lamas, Leire; Barron, Luis J R; Farmer, Linda; Aldai, Noelia

    2018-05-01

    Muscle fatty acid composition and odour-active compounds released during cooking were characterized in lamb chops (Longissimus thoracis et lumborum, n = 48) collected at retail level in northern Spain. Lamb samples were classified in two groups according to their 10 t/11 t-18:1 ratio: ≤1 (10 t-non-shifted, n = 21) and >1 (10 t-shifted, n = 27). Higher n-3 polyunsaturated fatty acid, vaccenic (11 t-18:1) and rumenic acid (9c,11 t-18:2), and iso-branched chain fatty acid contents were found in non-shifted lamb samples while n-6 polyunsaturated fatty acid, internal methyl-branched chain fatty acid, and 10 t-18:1 contents were greater in shifted samples. Regardless the fatty acid profile differences between lamb sample groups, odour-active compound profile was very similar and mostly affected by the cooking conditions. Overall, the main odour-active compounds of cooked lamb were described as "green", "meaty", "roasted", and "fatty" being methyl pyrazine, methional, dimethyl pyrazine, and dimethyl trisulphide the main odour-active compounds. Aldehydes and alcohols were the most abundant volatiles in all samples, and they were mostly originated from the oxidation of unsaturated fatty acids during cooking. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Lindley frailty model for a class of compound Poisson processes

    Science.gov (United States)

    Kadilar, Gamze Özel; Ata, Nihal

    2013-10-01

    The Lindley distribution gain importance in survival analysis for the similarity of exponential distribution and allowance for the different shapes of hazard function. Frailty models provide an alternative to proportional hazards model where misspecified or omitted covariates are described by an unobservable random variable. Despite of the distribution of the frailty is generally assumed to be continuous, it is appropriate to consider discrete frailty distributions In some circumstances. In this paper, frailty models with discrete compound Poisson process for the Lindley distributed failure time are introduced. Survival functions are derived and maximum likelihood estimation procedures for the parameters are studied. Then, the fit of the models to the earthquake data set of Turkey are examined.

  19. Amino acid compositions in heated carbonaceous chondrites and their compound-specific nitrogen isotopic ratios

    Science.gov (United States)

    Chan, Queenie Hoi Shan; Chikaraishi, Yoshito; Takano, Yoshinori; Ogawa, Nanako O.; Ohkouchi, Naohiko

    2016-01-01

    A novel method has been developed for compound-specific nitrogen isotope compositions with an achiral column which was previously shown to offer high precision for nitrogen isotopic analysis. We applied the method to determine the amino acid contents and stable nitrogen isotopic compositions of individual amino acids from the thermally metamorphosed (above 500 °C) Antarctic carbonaceous chondrites Ivuna-like (CI)1 (or CI-like) Yamato (Y) 980115 and Ornans-like (CO)3.5 Allan Hills (ALH) A77003 with the use of gas chromatography/combustion/isotope ratio mass spectrometry. ALHA77003 was deprived of amino acids due to its extended thermal alteration history. Amino acids were unambiguously identified in Y-980115, and the δ15N values of selected amino acids (glycine +144.8 ‰; α-alanine +121.2 ‰) are clearly extraterrestrial. Y-980115 has experienced an extended period of aqueous alteration as indicated by the presence of hydrous mineral phases. It has also been exposed to at least one post-hydration short-lived thermal metamorphism. Glycine and alanine were possibly produced shortly after the accretion event of the asteroid parent body during the course of an extensive aqueous alteration event and have abstained from the short-term post-aqueous alteration heating due to the heterogeneity of the parent body composition and porosity. These carbonaceous chondrite samples are good analogs that offer important insights into the target asteroid Ryugu of the Hayabusa-2 mission, which is a C-type asteroid likely composed of heterogeneous materials including hydrated and dehydrated minerals.

  20. A Compound Model for the Origin of Earth's Water

    Science.gov (United States)

    Izidoro, A.; de Souza Torres, K.; Winter, O. C.; Haghighipour, N.

    2013-04-01

    One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different water distribution models, and complement our study using the D/H ratio, finding possible relative contributions from each source and focusing on planets formed in the habitable zone. We find that the compound model plays an important role by showing greater advantage in the amount and time of water delivery in Earth-like planets.

  1. A COMPOUND MODEL FOR THE ORIGIN OF EARTH'S WATER

    International Nuclear Information System (INIS)

    Izidoro, A.; Winter, O. C.; De Souza Torres, K.; Haghighipour, N.

    2013-01-01

    One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different water distribution models, and complement our study using the D/H ratio, finding possible relative contributions from each source and focusing on planets formed in the habitable zone. We find that the compound model plays an important role by showing greater advantage in the amount and time of water delivery in Earth-like planets.

  2. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

    Science.gov (United States)

    Voorhees, Jaymie R.; Rohlman, Diane S.; Lein, Pamela J.; Pieper, Andrew A.

    2017-01-01

    Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally. PMID:28149268

  3. [Evaluation of compounding EDTA and citric acid on remediation of heavy metals contaminated soil].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Cai, Wen-Min

    2014-08-01

    As commonly used eluents, Na2EDTA (EDTA) and citric acid (CA) have been widely applied in remediation of soil contaminated by heavy metals. In order to evaluate the removal of arsenic, cadmium, copper, and lead in the contaminated soil collected in a chemical plant by compounding EDTA and CA, a series of stirring experiments were conducted. Furthermore, the changes in speciation distribution of heavy metals before and after washing were studied. The results showed that, adopting the optimal molar ratio of EDTA/CA (1:1), when the pH of the solution was 3, the stirring time was 30 min, the stirring rate was 150 r x min(-1) and the L/S was 5:1, the removal rates of arsenic, cadmium, copper and lead could reach 11.72%, 43.39%, 24.36% and 27.17%, respectively. And it was found that after washing, for arsenic and copper, the content of acid dissolved fraction rose which increased the percentage of available contents. Fe-Mn oxide fraction mainly contributed to the removal of copper. As for cadmium, the percentages of acid dissolved fraction, Fe-Mn oxide fraction and organic fraction also decreased. In practical projects, speciation changes would pose certain environmental risk after soil washing, which should be taken into consideration.

  4. Photoproduction of hydrogen peroxide in aqueous solution from model compounds for chromophoric dissolved organic matter (CDOM).

    Science.gov (United States)

    Clark, Catherine D; de Bruyn, Warren; Jones, Joshua G

    2014-02-15

    To explore whether quinone moieties are important in chromophoric dissolved organic matter (CDOM) photochemistry in natural waters, hydrogen peroxide (H2O2) production and associated optical property changes were measured in aqueous solutions irradiated with a Xenon lamp for CDOM model compounds (dihydroquinone, benzoquinone, anthraquinone, napthoquinone, ubiquinone, humic acid HA, fulvic acid FA). All compounds produced H2O2 with concentrations ranging from 15 to 500 μM. Production rates were higher for HA vs. FA (1.32 vs. 0.176 mM h(-1)); values ranged from 6.99 to 0.137 mM h(-1) for quinones. Apparent quantum yields (Θ app; measure of photochemical production efficiency) were higher for HA vs. FA (0.113 vs. 0.016) and ranged from 0.0018 to 0.083 for quinones. Dihydroquinone, the reduced form of benzoquinone, had a higher production rate and efficiency than its oxidized form. Post-irradiation, quinone compounds had absorption spectra similar to HA and FA and 3D-excitation-emission matrix fluorescence spectra (EEMs) with fluorescent peaks in regions associated with CDOM. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Aquatic pathways model to predict the fate of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L.; Mellinger, P.J.

    1983-04-01

    Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. The properties of heavier molecular weight phenolics (indanols, naphthols) are not well enough understood at this time to make similar judgements. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation (using APM) of a spill of solvent refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor.

  6. Aromatic products from reaction of lignin model compounds with UV-alkaline peroxide

    International Nuclear Information System (INIS)

    Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

    1997-01-01

    A series of guaiacyl and syringyl lignin model compounds and their methylated analogues were reacted with alkaline hydrogen peroxide while irradiating with UV light at 254 nm. The aromatic products obtained were investigated by gas chromatography-mass spectrometry (GC-MS). Guaiacol, syringol and veratrol gave no detectable aromatic products. However, syringol methyl ether gave small amounts of aromatic products, resulting from ring substitution and methoxyl displacement by hydroxyl radicals. Reaction of vanillin and syringaldehyde gave the Dakin reaction products, methoxy-1,4-hydroquinones, while reaction of their methyl ethers yielded benzoic acids. Acetoguaiacone, acetosyringone and their methyl ethers afforded several hydroxylated aromatic products, but no aromatic products were identified in the reaction mixtures from guaiacylpropane and syringylpropane. In contrast, veratrylpropane gave a mixture from which 17 aromatic hydroxylated compounds were identified. It is concluded that for phenolic lignin model compounds, particularly those possessing electrondonating aromatic ring substituents, ring-cleavage reactions involving superoxide radical anions are dominant, whereas for non-phenolic lignin models, hydroxylation reactions through attack of hydroxyl radicals prevail

  7. A Cocatalytic Effect between Meldrum's Acid and Benzoxazine Compounds in Preparation of High Performance Thermosetting Resins.

    Science.gov (United States)

    Chen, Yi; Lin, Liang-Kai; Chiang, Shu-Jen; Liu, Ying-Ling

    2017-02-01

    In this work, a cocatalytic effect between Meldrum's acid (MA) and benzoxazine (Bz) compounds has been explored to build up a self-promoting curing system. Consequently, the MA/Bz reactive blend exhibits a relatively low reaction temperature compared to the required temperatures for the cross-linking reactions of the pure MA and Bz components. This feature is attractive for energy-saving processing issues. Moreover, the thermosetting resins based on the MA/Bz reactive blends have been prepared. The MA component can generate additional free volume in the resulting resins, so as to trap air in the resin matrix and consequently to bring low dielectric constants to the resins. The MA-containing agent is an effective modifier for benzoxazine resins to reduce their dielectric constants. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Widespread occurrence of mycosporine-like amino acid compounds in scleractinians from French Polynesia

    Science.gov (United States)

    Teai, T.; Drollet, J. H.; Bianchini, J.-P.; Cambon, A.; Martin, P. M. V.

    1997-07-01

    A survey of 23 species of scleractinians, belonging to seven families and 8 genera, collected from two different areas in French Polynesia, showed that all specimens possessed between four and seven UV-absorbing compounds, identified as mycosporine-like amino acids (MAAs). In all, 11 different MAAs molecules were found, of which two were previously unknown. Palythine and mycosporine-glycine were the most abundant MAAs in the corals. With few exceptions, most specimens of each species possessed the same pattern of MAAs. Similarly, species from the same genus also had very similar qualitative composition of MAAs, although quantities of individuals MAAs varied from specimen to specimen. This suggests that MAAs are ancient and evolutionarily well conserved.

  9. Optical spectra of vanadium (5, 4) compounds during extraction by di-2-ethylhexylphosphoric acid

    International Nuclear Information System (INIS)

    Kurbatova, L.D.; Medvedeva, N.I.

    2000-01-01

    Optical spectra of vanadium (5, 4) complexes with HDEHP are studied using literature data on quantum-chemical calculations of vanadium (5) and vanadium (4) oxides. Extraction of vanadium is conducted by undiluted HDEHP from sulfuric acid solutions. Absorption electron spectra (AES) of vanadium (5), vanadium (4) and vanadium (5, 4) compounds are presented. In AES of vanadium (5, 4) four absorption bands at 24000, 17000, 14500 and 13500 cm -1 appear. Comparison with spectra of vanadium (5) and vanadium (4) shows that band 17000 cm -1 which appears only during mutual extraction of vanadium (5) and vanadium (4) is caused by transitions appearing between filled and empty levels of d-zone broadened by vanadium (5) and vanadium (4) interaction [ru

  10. Sprayed microspheres of poly(lactic acid) obtained with calcium compounds

    International Nuclear Information System (INIS)

    Goncalves, Raquel P.; Picciani, Paulo H. de Souza; Dias, Marcos L.

    2011-01-01

    In this work PLLA and PDLA were synthesized using calcium methoxide (Ca(OMe) 2 ) as initiator. This compound shows good activity in the bulk polymerization of L-lactide (LLA) and D-lactide (DLA) producing polymers with average molecular weight up to 22,300 g/mol, but with microstructure containing a significant amount of estereoerros, as revealed by 13 C NMR. Block copolymers containing blocks of L-and D-lactic acid were also prepared, using the method of sequential addition of LLA and DLA in an attempt to obtain stereo complexes. Analyses of scanning electron microscopy (SEM) revealed that the polymers obtained with catalysts of calcium produced PLA microspheres with diameters of around 5 μm via electro spray technique. (author)

  11. Impact of organic-mineral matter interactions on thermal reaction pathways for coal model compounds

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, A.C. III; Britt, P.F.; Struss, J.A. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

    1995-07-01

    Coal is a complex, heterogeneous solid that includes interdispersed mineral matter. However, knowledge of organic-mineral matter interactions is embryonic, and the impact of these interactions on coal pyrolysis and liquefaction is incomplete. Clay minerals, for example, are known to be effective catalysts for organic reactions. Furthermore, clays such as montmorillonite have been proposed to be key catalysts in the thermal alteration of lignin into vitrinite during the coalification process. Recent studies by Hatcher and coworkers on the evolution of coalified woods using microscopy and NMR have led them to propose selective, acid-catalyzed, solid state reaction chemistry to account for retained structural integrity in the wood. However, the chemical feasibility of such reactions in relevant solids is difficult to demonstrate. The authors have begun a model compound study to gain a better molecular level understanding of the effects in the solid state of organic-mineral matter interactions relevant to both coal formation and processing. To satisfy the need for model compounds that remain nonvolatile solids at temperatures ranging to 450 C, model compounds are employed that are chemically bound to the surface of a fumed silica (Si-O-C{sub aryl}linkage). The organic structures currently under investigation are phenethyl phenyl ether (C{sub 6}H{sub 5}CH{sub 2}CH{sub 2}OC{sub 6}H{sub 5}) derivatives, which serve as models for {beta}-alkyl aryl ether units that are present in lignin and lignitic coals. The solid-state chemistry of these materials at 200--450 C in the presence of interdispersed acid catalysts such as small particle size silica-aluminas and montmorillonite clay will be reported. Initial focus will be on defining the potential impact of these interactions on coal pyrolysis and liquefaction.

  12. Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L.) Grape Berries.

    Science.gov (United States)

    Ju, Yan-Lun; Liu, Min; Zhao, Hui; Meng, Jiang-Fei; Fang, Yu-Lin

    2016-10-12

    The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA) and methyl jasmonate (MeJA) on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC) and individual anthocyanins. Lipoxygenase (LOX) activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

  13. Experimental design for extraction and quantification of phenolic compounds and organic acids in white "Vinho Verde" grapes.

    Science.gov (United States)

    Dopico-García, M S; Valentão, P; Guerra, L; Andrade, P B; Seabra, R M

    2007-01-30

    An experimental design was applied for the optimization of extraction and clean-up processes of phenolic compounds and organic acids from white "Vinho Verde" grapes. The developed analytical method consisted in two steps: first a solid-liquid extraction of both phenolic compounds and organic acids and then a clean-up step using solid-phase extraction (SPE). Afterwards, phenolic compounds and organic acids were determined by high-performance liquid chromatography (HPLC) coupled to a diode array detector (DAD) and HPLC-UV, respectively. Plackett-Burman design was carried out to select the significant experimental parameters affecting both the extraction and the clean-up steps. The identified and quantified phenolic compounds were: quercetin-3-O-glucoside, quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-glucoside, quercetin, kaempferol and epicatechin. The determined organic acids were oxalic, citric, tartaric, malic, shikimic and fumaric acids. The obtained results showed that the most important variables were the temperature (40 degrees C) and the solvent (acid water at pH 2 with 5% methanol) for the extraction step and the type of sorbent (C18 non end-capped) for the clean-up step.

  14. Experimental and Kinetic Modeling Studies on the Conversion of Sucrose to Levulinic Acid and 5-Hydroxymethylfurfural Using Sulfuric Acid in Water

    NARCIS (Netherlands)

    Tan-Soetedjo, Jenny N. M.; van de Bovenkamp, Henk H.; Abdilla, Ria M.; Rasrendra, Carolus B.; van Ginkel, Jacob; Heeres, Hero J.

    2017-01-01

    We here report experimental and kinetic modeling studies on the conversion of sucrose to levulinic acid (LA) and 5-hydroxymethylfurfural (HMF) in water using sulfuric acid as the catalyst. Both compounds are versatile building blocks for the synthesis of various biobased (bulk) chemicals. A total of

  15. Synthesis and evaluation of ?-hydroxy fatty acid-derived heterocyclic compounds with potential industrial interest

    Directory of Open Access Journals (Sweden)

    El-Sayed, R.

    2006-12-01

    Full Text Available T2-Hydroxyheptadecanoic acid chloride (2 reacted with anthranilic acid to produce 2-substituted-3,1-benzoxazin-4-one (3 which was used as starting material to synthesize some condensed and non-condensed heterocyclic compounds by reaction with nitrogen nucleophiles e.g., hydrazine hydrate, and formamide. The products were subjected to reaction with different moles of propylene oxide (n = 5, 10, 15 to produce a novel group of nonionic compounds having a double function as antibacterial and surface active agents which can be used in the manufacturing of drugs, cosmetics, pesticides or can be used as antibacterial and/or antifungal additives. The surface active properties as surface and interfacial tension, cloud point, foaming height, wetting time, and emulsification power were determined, the antimicrobial and biodegradability were also screened.El cloruro del ácido 2-hidroxiheptadecanoico (2 reaccionó con el ácido antranílico para producir 3,1-benzoxazin-4-onas 2-sustituidas que fueron usadas como material de partida en la síntesis de compuestos heterocíclicos condensados y no condensados por reacción con nucleófilos nitrogenados, como la hidracina o la formamida. Los productos fueron hechos reaccionar con diferentes moles de óxido de propileno (n = 5, 10, 15 para producir un grupo nuevo de compuestos no-iónicos teniendo una doble función como antibacterianos y tensoactivos que pueden ser usados en la manufactura de medicamentos, cosméticos, pesticidas, o pueden ser usados como aditivos antibacterianos y/o antifúngicos. Se determinaron diversas propiedades físicas de los compuestos preparados así como sus efectos antimicrobianos y sus biodegrabilidad.

  16. Mefenamic Acid Induced Nephrotoxicity: An Animal Model

    Directory of Open Access Journals (Sweden)

    Muhammad Nazrul Somchit

    2014-12-01

    Full Text Available Purpose: Nonsteroidal anti-inflammatory drugs (NSAIDs are used for the treatment of many joint disorders, inflammation and to control pain. Numerous reports have indicated that NSAIDs are capable of producing nephrotoxicity in human. Therefore, the objective of this study was to evaluate mefenamic acid, a NSAID nephrotoxicity in an animal model. Methods: Mice were dosed intraperitoneally with mefenamic acid either as a single dose (100 or 200 mg/kg in 10% Dimethyl sulfoxide/Palm oil or as single daily doses for 14 days (50 or 100 mg/kg in 10% Dimethyl sulfoxide/Palm oil per day. Venous blood samples from mice during the dosing period were taken prior to and 14 days post-dosing from cardiac puncture into heparinized vials. Plasma blood urea nitrogen (BUN and creatinine activities were measured. Results: Single dose of mefenamic acid induced mild alteration of kidney histology mainly mild glomerular necrosis and tubular atrophy. Interestingly, chronic doses induced a dose dependent glomerular necrosis, massive degeneration, inflammation and tubular atrophy. Plasma blood urea nitrogen was statistically elevated in mice treated with mefenamic acid for 14 days similar to plasma creatinine. Conclusion: Results from this study suggest that mefenamic acid as with other NSAIDs capable of producing nephrotoxicity. Therefore, the study of the exact mechanism of mefenamic acid induced severe nephrotoxicity can be done in this animal model.

  17. The determination of vitamin C, organic acids, phenolic compounds concentration of Red and Golden delicious apple grown in Lorestan province

    Directory of Open Access Journals (Sweden)

    ebrahim Falahi

    2013-08-01

    Results: Ascorbic acid concentrations in Red and Golden delicious apples were 9.49 and 9.09 mg and 9.29 mg in total per 100 grams. Malic acid concentrations in Red and Golden delicious apples were 0.26 and 0.27 and citric acid concentrations in Red and Golden delicious apples were 0.28 mg per 100 grams in both cultivars. Acidity of Red delicious was 4 and Golden delicious was about 3.7. The acidity of Red delicious was higher than the Golden one. α-farensene was the most phenolic compound in both cultivars. Conclusion: Finally, apple cultivars grown in Lorestan have 3 times more ascorbic acid than the amount which mentioned in Iranian Food Consumption Table. There were no significant relation about malic and citric acid in both cultivars.

  18. Corrosion inhibition of carbon steel in acidic medium by orange peel extract and its main antioxidant compounds

    International Nuclear Information System (INIS)

    M’hiri, Nouha; Veys-Renaux, Delphine; Rocca, Emmanuel; Ioannou, Irina; Boudhrioua, Nourhéne Mihoubi; Ghoul, Mohamed

    2016-01-01

    Highlights: • Catechol and derived functions are responsible for flavonoids antioxidant activity. • Antioxidant activity of adsorbed molecules explains cathodic inhibition. • Orange peel extract inhibition is enhanced by the precipitation of a covering film. - Abstract: Chemical compounds of orange peel extracts were identified and their antioxidant activities were determined. The inhibiting effect on acidic steel corrosion brought by the extract and selected antioxidant compounds (neohesperidin, naringin, ascorbic acid) was evaluated separately by electrochemical methods. Whatever the extract concentration, a significant inhibition is observed, whereas selected antioxidant compounds show only a slight effect. Both electrochemical impedance spectroscopy results and scanning electron microscopy observations after immersion reveal that the inhibiting efficiency of orange peel extract is not only due to the antioxidant activity of its compounds but also to the precipitation of a surface film.

  19. Synthesis of novel 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds and their evaluation for tuberculostatic activity.

    Science.gov (United States)

    Gobis, Katarzyna; Foks, Henryk; Bojanowski, Krzysztof; Augustynowicz-Kopeć, Ewa; Napiórkowska, Agnieszka

    2012-01-01

    A series of novel 3-cyclohexylpropanoic acid derivatives and 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds (1-8) have been synthesized and evaluated for tuberculostatic activity. Compounds 1a, 1c, 1e and 1f bearing benzimidazole or benzimidazole-like systems showed the most potent tuberculostatic activity against Mycobacterium tuberculosis strains with MIC values ranging from 1.5 to 12.5μg/mL. More importantly 1a (6-chloro-2-(2-cyclohexylethyl)-4-nitro-1H-benzo[d]imidazole) and 1f (2-(2-cyclohexylethyl)-1H-imidazo[4,5-b]phenazine) appeared selective for M. tuberculosis as compared with eukaryotic cells (human fibroblasts), and other antimicrobial strains. These compounds may thus represent a novel, selective class of antitubercular agents. Additionally compound 1a stimulated type I collagen output by fibroblasts, in vitro. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Coordination compounds of cobalt(II), nickel(II), copper(II), and zinc(II) with pantothenic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shabilalov, A.A.; Yunuskhodzhaev, A.N.; Khodzhaev, O.F.; Azizov, M.A.

    1986-11-01

    The compounds Ni(PANA - H)/sub 2/ x 4H/sub 2/O (PANA stands for pantothenic acid, and - H indicates a deprotonated ligand), Cu(PANA - H)/sub 2/ x 2H/sub 2/O, Zn(PANA - H)/sub 2/ x H/sub 2/O, Co(PANA - H)Cl x H/sub 2/O, and Ni(PANA - H)Cl x 3H/sub 2/O have been synthesized on the basis of pantothenic acid and Co(II), Ni(II), Cu(II), and Zn(II) salts in aqueous media. The compounds have been identified by elemental and x-ray diffraction analysis. Some physicochemical properties (solubility, melting point, molar conductivity) of the compounds obtained have been studied. The structure of the compounds isolated has been established on the basis of an analysis of their IR, ESR, and electronic spectra, as well as derivatograms.

  1. Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy

    Directory of Open Access Journals (Sweden)

    Jurkić Lela Munjas

    2013-01-01

    Full Text Available Abstract Silicon (Si is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4, as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K, the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel, silica gel (amorphous silicon dioxide, and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4 in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources.

  2. Characterization of Fatty Acid, Amino Acid and Volatile Compound Compositions and Bioactive Components of Seven Coffee (Coffea robusta Cultivars Grown in Hainan Province, China

    Directory of Open Access Journals (Sweden)

    Wenjiang Dong

    2015-09-01

    Full Text Available Compositions of fatty acid, amino acids, and volatile compound were investigated in green coffee beans of seven cultivars of Coffea robusta grown in Hainan Province, China. The chlorogenic acids, trigonelline, caffeine, total lipid, and total protein contents as well as color parameters were measured. Chemometric techniques, principal component analysis (PCA, hierarchical cluster analysis (HCA, and analysis of one-way variance (ANOVA were performed on the complete data set to reveal chemical differences among all cultivars and identify markers characteristic of a particular botanical origin of the coffee. The major fatty acids of coffee were linoleic acid, palmitic acid, oleic acid, and arachic acid. Leucine (0.84 g/100 g DW, lysine (0.63 g/100 g DW, and arginine (0.61 g/100 g DW were the predominant essential amino acids (EAAs in the coffee samples. Seventy-nine volatile compounds were identified and semi-quantified by HS-SPME/GC-MS. PCA of the complete data matrix demonstrated that there were significant differences among all cultivars, HCA supported the results of PCA and achieved a satisfactory classification performance.

  3. An approach to accidents modeling based on compounds road environments.

    Science.gov (United States)

    Fernandes, Ana; Neves, Jose

    2013-04-01

    The most common approach to study the influence of certain road features on accidents has been the consideration of uniform road segments characterized by a unique feature. However, when an accident is related to the road infrastructure, its cause is usually not a single characteristic but rather a complex combination of several characteristics. The main objective of this paper is to describe a methodology developed in order to consider the road as a complete environment by using compound road environments, overcoming the limitations inherented in considering only uniform road segments. The methodology consists of: dividing a sample of roads into segments; grouping them into quite homogeneous road environments using cluster analysis; and identifying the influence of skid resistance and texture depth on road accidents in each environment by using generalized linear models. The application of this methodology is demonstrated for eight roads. Based on real data from accidents and road characteristics, three compound road environments were established where the pavement surface properties significantly influence the occurrence of accidents. Results have showed clearly that road environments where braking maneuvers are more common or those with small radii of curvature and high speeds require higher skid resistance and texture depth as an important contribution to the accident prevention. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Abd El-Kaway, Marwa Y.; Hindawy, Ahmed M.; Soayed, Amina A.

    The pH effect on electronic absorption spectra of some biologically active nucleic acid constituents have been studied at room temperature and the mechanism of ionization was explained. These compounds are of two categories (pyrimidines: [barbital; 5,5'-diethyl-barbituric acid], [SBA; 4,6-dihydroxy-2-mercapto-pyrimidin], [NBA; 5-nitro-2,4,6(1H,3H,5H)-pyrimidine trione] and [TU; 2,3-dihydro-2-thioxo-pyrimidin-4(1H)-one]) and (purines: [adenine; 6-amino purine], its [Schiff bases derived from adenine-acetylacetone; (Z)-4-(7H-purin-6-ylimino)pentan-2-one) and adenine-salicylaldehyde; 2-((7H-purin-6-ylimino) methyl) phenol] and its [Azo derived from adenine-resorcinol; 4-((7H-purin-6-yl)-diazenyl) benzene-1,3-diol]. The phenomena of tautomerization assigned different tautomers. Different spectrophotometric methods are applied to evaluate the pK's values that explained with their molecular structures. The interaction of Fe3+ with some selected pyrimidines (barbital, NBA and SBA) was explained using familiar six spectrophotometric methods. The data typified the existence of different absorbing species with the different stoichiometries 1:1, 1:2, 1:3 and 2:3. The stability constant of the complexes was computed. More approach was deduced to assign the existence of different species applying the distribution diagrams.

  5. Chemical Reductive Transformations of Synthetic Organic Compounds. Probe Compound Studies and Mechanistic Modeling

    National Research Council Canada - National Science Library

    Peyton, Gary

    2001-01-01

    Advanced Oxidation Processes (AOPs) can be used to selectively remove DNT (2,4-dinitrotoluene) from a complex waste stream by adding a precursor compound such as ethanol, which forms a reducing radical upon reaction with hydroxyl radical...

  6. Aromatic oxygen compounds boiling from 180/sup 0/ to 225/sup 0/ from acid oils in low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, A; Kattwinkel, G

    1950-01-01

    To determine the composition of the Krupp-Lurgi low-temperature coal tar and to develop methods for isolating the various compounds, a quantitative investigation was made of the dry tar acid mixture. The aromatic O compounds boiling up to 225/sup 0/ were secured by fractionation with one of the several columns that are described. Large volumes of tar were fractionated under vacuum in an apparatus with a 10-liter flask, electrically heated, and provided with a fractionating column (packed) with a jacket supplied by recirculated oil, externally heated. Large volumes were fractionated to give sufficient quantities of the O compounds. The method of fractional extraction, not described herein, made the separation of the acid oils by fractional distillation much easier. The aromatic O compounds present in greatest proportion are relatively easily isolated; those present in small quantities and more difficult to separate can be removed as a mixture, which can be hydrogenated directly to solvents. Phenols and cresols are formed in about equal fractions in low-temperature carbonization. Of the various xylenols, the sym-xylenol is present to the greatest extent. O compounds with longer side chains than C/sub 2/ were present only to a very slight extent. At the temperature of formation of these tars, side chains of three or more C atoms formed closed ring compounds (indan derivatives, etc.). Little change appears to occur up to 225/sup 0/ in the fractionation of these acid oils.

  7. Effect of drying of figs (Ficus carica L.) on the contents of sugars, organic acids, and phenolic compounds.

    Science.gov (United States)

    Slatnar, Ana; Klancar, Urska; Stampar, Franci; Veberic, Robert

    2011-11-09

    Fresh figs were subjected to two different drying processes: sun-drying and oven-drying. To assess their effect on the nutritional and health-related properties of figs, sugars, organic acids, single phenolics, total phenolics, and antioxidant activity were determined before and after processing. Samples were analyzed three times in a year, and phenolic compounds were determined using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). In figs, monomer sugars predominate, which is important nutritional information, and the content of sugars as well as organic acids in fresh figs was lower than in dried fruits. However, the best sugar/organic acid ratio was measured after the sun-drying process. Analysis of individual phenolic compounds revealed a higher content of all phenolic groups determined after the oven-drying process, with the exception of cyanidin-3-O-rutinoside. Similarly, higher total phenolic content and antioxidant activity were detected after the drying process. With these results it can be concluded that the differences in analyzed compounds in fresh and dried figs are significant. The differences between the sun-dried and oven-dried fruits were determined in organic acids, sugars, chlorogenic acid, catechin, epicatechin, kaempferol-3-O-glucoside, luteolin-8-C-glucoside, and total phenolic contents. The results indicate that properly dried figs can be used as a good source of phenolic compounds.

  8. Development of a canine model to enable the preclinical assessment of pH-dependent absorption of test compounds.

    Science.gov (United States)

    Fancher, R Marcus; Zhang, Hongjian; Sleczka, Bogdan; Derbin, George; Rockar, Richard; Marathe, Punit

    2011-07-01

    A preclinical canine model capable of predicting a compound's potential for pH-dependent absorption in humans was developed. This involved the surgical insertion of a gastrostomy feeding tube into the stomach of a beagle dog. The tube was sutured in position to allow frequent withdrawal of gastric fluid for pH measurement. Therefore, it was possible to measure pH in the stomach and assess the effect of gastric pH-modifying agents on the absorption of various test compounds. Fasted gastric pH in the dog showed considerable inter- and intra-animal variability. Pretreatment of pentagastrin (6 µg/kg intramuscularly) 20 min prior to test compound administration was determined to be adequate for simulating fasting stomach pH in humans. Pretreatment with famotidine [40 mg orally] 1 h prior to test compound administration was determined to be adequate for simulating human gastric pH when acid-reducing agents are coadministered. Pentagastrin and famotidine pretreatments were used to test two discovery compounds and distinct differences in their potential for pH-dependent absorption were observed. The model described herein can be used preclinically to screen out compounds, differentiate compounds, and support the assessment of various formulation- and prodrug-based strategies to mitigate the pH effect. Copyright © 2011 Wiley-Liss, Inc. and the American Pharmacists Association

  9. On the (R,s,Q) Inventory Model when Demand is Modelled as a Compound Process

    NARCIS (Netherlands)

    Janssen, F.B.S.L.P.; Heuts, R.M.J.; de Kok, T.

    1996-01-01

    In this paper we present an approximation method to compute the reorder point s in a (R; s; Q) inventory model with a service level restriction, where demand is modelled as a compound Bernoulli process, that is, with a xed probability there is positive demand during a time unit, otherwise demand is

  10. A thermal conductivity model for U-­Si compounds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andersson, Anders David Ragnar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-02

    U3Si2 is a candidate for accident tolerant nuclear fuel being developed as an alternative to UO2 in commercial light water reactors (LWRs). One of its main benefits compared to UO2 is higher thermal conductivity that increases with temperature. This increase is contrary to UO2, for which the thermal conductivity decreases with temperature. The reason for the difference is the electronic origin of thermal conductivity in U3Si2, as compared to the phonon mechanism responsible for thermal transport in UO2. The phonon thermal conductivity in UO2 is unusually low for a fluorite oxide due to the strong interaction with the spins in the paramagnetic phase. The thermal conductivity of U3Si2 as well as other U-­Si compounds has been measured experimentally [1-­4]. However, for fuel performance simulations it is also critical to model the degradation of the thermal conductivity due to damage and microstructure evolution caused by the reactor environment (irradiation and high temperature). For UO2 this reduction is substantial and it has been the topic of extensive NEAMS research resulting in several publications [5, 6]. There are no data or models for the evolution of the U3Si2 thermal conductivity under irradiation. We know that the intrinsic thermal conductivities of UO2 (semi-conductor) and U3Si2 (metal) are very different, and we do not necessarily expect the dependence on damage to be the same either, which could present another advantage for the silicide fuel. In this report we summarize the first step in developing a model for the thermal conductivity of U-­Si compounds with the goal of capturing the effect of damage in U3Si2. Next year, we will focus on lattice damage. We will also attempt to assess the impact of fission gas bubbles.

  11. Metabolism of arachidonic acid derivatives (prostaglandins and related compounds). Radioimmunological methods to measure certain of these compounds

    International Nuclear Information System (INIS)

    Sors, Herve.

    1978-06-01

    The detection of prostaglandins, present in tissues at concentrations of about 10 -7 to 10 -11 g/g and able to induce physiological effects at concentrations of the picomole order, sets the analyst a particularly difficult problem. Owing to the complexity of their metabolism, the existence of many structurally similar compounds and the low concentrations present, it is necessary to develop highly specific and sensitive methods. Suitable techniques are: the biological activity test or biotest; gas-liquid chromatogaphy combined with mass spectrometry; the radioimmunological method. The radioimmunological analysis procedure is developed: preparation of immunogens and immunisation; preparation of tracers; treatment of biological samples. The different radioimmunological systems are presented: determination of antiserum affinity constants; dose-response curves and sensitivities; specificities; applications to biological measurements. Some remarks are called for concerning the RIA of prostaglandins: the difficulty of obtaining antisera seems to depend on the nature of the PG, a good anti-PGB or PGFα is easier to get than an anti-PGA or PGE. The analysis of each compound implies the use of a corresponding immunoserum and it is therefore essential to have a range of immunosera in order to study as large a number of biosynthesis derivatives as possible; too many physiological investigations are still viewed in relation to one PG only (often a primary PG) at the expense of other derivatives [fr

  12. A Neat Trick Using Oxalic Acid Dihydrate and Potassium Permanganate and Other Experiments with Small Organic Amine or Oxygenated Compounds

    Science.gov (United States)

    Kelland, Malcolm A.

    2011-01-01

    Solid potassium permanganate (KMnO[subscript 4]) is shown to react in a variety of ways with small organic amines or oxygenated compounds depending on whether they are liquids or solids and whether water is present. In particular, its reaction with solid oxalic acid dihydrate can be initiated by the moisture in one's breath, making an intriguing…

  13. Sacha Inchi (Plukenetia volubilis): a seed source of polyunsaturated fatty acids, tocopherols, phytoserols, phenolic compounds and antioxidant capacity

    NARCIS (Netherlands)

    Chirinos, R.; Zuloeta, G.; Pedreschi Plasencia, R.P.

    2013-01-01

    Fatty acids (FA), phytosterols, tocopherols, phenolic compounds, total carotenoids and hydrophilic and lipophilic ORAC antioxidant capacities were evaluated in 16 cultivars of Sacha inchi (SI) seeds with the aim to valorise them and offer more information on the functional properties of SI seeds. A

  14. Hepatoprotective Activity of a Complex Compound of 5-Hydroxy-6-Methyluracil and Succinic Acid in Experimental Peritonitis

    Directory of Open Access Journals (Sweden)

    D. A. Yenikeyev

    2008-01-01

    Full Text Available Objective: to evaluate the hepatoprotective efficacy of a complex compound of 5-hydroxy-6-methyluracil and succinic acid in experimental peritonitis. Materials and methods. Experiments were carried out on 48 male albino rats in which peritonitis was simulated via intraperitoneal administration of 7% fecal suspension in a dose of 0.6 ml per 100 g bodyweight. The rate of free radical oxidation processes, the activity of antioxidative protection, the degree of endogenous intoxication and cytolytic syndrome, and the effect of the test compound on these parameters were estimated in the experiment. Results. With the development of an abdominal inflammatory process, there were increases in rates of endogenous intoxication and free radical oxidation (FRO, a change in the activity of antioxidative protection enzymes, and a reduction in the levels of ceruloplasmin and sulfahydryl groups. The complex compound, that comprised 5-hydroxy-6-methyluracil and succinic acid used as monotherapy, reduced the degree of endogenous intoxication, FRO, and lipid peroxidation-antioxidative defense system imbalance. Conclusion. The experimental data suggest that the use of the complex compound containing succinic acid and 5-hydroxy-6-methy-luracil is pathogenetically warranted. Key words: peritonitis, lipid peroxidation, antioxidants, succinic acid, pyrim-idine derivatives.

  15. Inoculation of the nonlegume Capsicum annuum L. with Rhizobium strains. 2. Changes in sterols, triterpenes, fatty acids, and volatile compounds.

    Science.gov (United States)

    Silva, Luís R; Azevedo, Jessica; Pereira, Maria J; Carro, Lorena; Velazquez, Encarna; Peix, Alvaro; Valentão, Patrícia; Andrade, Paula B

    2014-01-22

    Peppers (Capsicum spp.) are consumed worldwide, imparting flavor, aroma, and color to foods, additionally containing high concentrations of biofunctional compounds. This is the first report about the effect of the inoculation of two Rhizobium strains on sterols, triterpenes, fatty acids, and volatile compounds of leaves and fruits of pepper (Capsicum annuum L.) plants. Generally, inoculation with strain TVP08 led to the major changes, being observed a decrease of sterols and triterpenes and an increase of fatty acids, which are related to higher biomass, growth, and ripening of pepper fruits. The increase of volatile compounds may reflect the elicitation of plant defense after inoculation, since the content on methyl salicylate was significantly increased in inoculated material. The findings suggest that inoculation with Rhizobium strains may be employed to manipulate the content of interesting metabolites in pepper leaves and fruits, increasing potential health benefits and defense abilities of inoculated plants.

  16. A clinical and histopathological comparison of the effectiveness of salicylic acid to a compound of inorganic acids for the treatment of digital dermatitis in cattle

    DEFF Research Database (Denmark)

    Capion, N.; Larsson, E. K.; Nielsen, O. L.

    2018-01-01

    ; however, the demand for effective nonantibiotic alternatives is increasing. The objective was to evaluate the performance of 3 nonantibiotic topical treatments (salicylic acid and a compound of inorganic acids in a 20% solution and in a dry form) on DD in a commercial dairy herd. Within the 30-d test...... of spirochetes present in the epidermis), 2 (moderate number of spirochetes present and reaching an intermediary level in the epidermis), and 3 (large number of spirochetes present and reaching the deepest part of the epidermis or the superficial dermis). The improvement rate was 10/14 (71%) for salicylic acid......, 11/15 (73%) for the inorganic acid solution, and 8/13 (62%) for the inorganic acid powder. The analysis showed no difference among treatments. The association between clinical score and histopathological score was determined by an odds ratio. The odds ratio of a healed lesion having spirochetes...

  17. Characterization of Binary Organogels Based on Some Azobenzene Compounds and Alkyloxybenzoic Acids with Different Chain Lengths

    Directory of Open Access Journals (Sweden)

    Yongmei Hu

    2014-01-01

    Full Text Available In this work the gelation behaviors of binary organogels composed of azobenzene amino derivatives and alkyloxybenzoic acids with different lengths of alkyl chains in various organic solvents were investigated and characterized. The corresponding gelation behaviors in 20 solvents were characterized and shown as new binary organic systems. It showed that the lengths of substituent alkyl chains in compounds have played an important role in the gelation formation of gelator mixtures in present tested organic solvents. Longer methylene chains in molecular skeletons in these gelators seem more suitable for the gelation of present solvents. Morphological characterization showed that these gelator molecules have the tendency to self-assemble into various aggregates from lamella, wrinkle, and belt to dot with change of solvents and gelator mixtures. Spectral characterization demonstrated different H-bond formation and hydrophobic force existing in gels, depending on different substituent chains in molecular skeletons. Meanwhile, these organogels can self-assemble to form monomolecular or multilayer nanostructures owing to the different lengths of due to alkyl substituent chains. Possible assembly modes for present xerogels were proposed. The present investigation is perspective to provide new clues for the design of new nanomaterials and functional textile materials with special microstructures.

  18. Chlorogenic acid was specifically induced among phenolic compounds in centipedegrass by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    An, Byung Chul; Barampuram, Shyamkumar; Lee, Seung Sik; Lee, Eun Mi; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-03-15

    Centipedegrass is a warm season turfgrass in the world. Chlorogenic acid (CA) is one of the important compounds present in the leaf of centipedegrass and already known as an antioxidant, CA has become a key resistance against insect pests and bacteria pathogens of agricultural and horticultural plants during seedlling stage. Furthermore, CA is accumulated by abiotic stress such as an UV irradiation. In present study, we investigated enhancement of the level of CA upon gamma irradiation in centipedegrass. The high performance liquid chromatography (HPLC) data analysis showed an approximately increasing of the CA levels from among the irradiated samples. However, plants irradiated at 50 Gy showed a constant increase in the CA level (0.0066 to 0.114 mg ml{sup -1} and 0.0258 to 0.2211 mg ml{sup -1}, respectively) from 3{sup rd} to 15{sup th} day among one and three month irradiated plants compared to control. The present study, indicates an increase in the CA level upon gamma irradiation, suggests strategy for conferment of strong resistance on seedling stage plants by gamma irradiation as simplicity and cheaply method.

  19. Compound-specific isotope analysis resolves the dietary origin of docosahexaenoic acid in the mouse brain.

    Science.gov (United States)

    Lacombe, R J Scott; Giuliano, Vanessa; Colombo, Stefanie M; Arts, Michael T; Bazinet, Richard P

    2017-10-01

    DHA (22:6n-3) may be derived from two dietary sources, preformed dietary DHA or through synthesis from α-linolenic acid (ALA; 18:3n-3). However, conventional methods cannot distinguish between DHA derived from either source without the use of costly labeled tracers. In the present study, we demonstrate the proof-of-concept that compound-specific isotope analysis (CSIA) by GC-isotope ratio mass spectrometry (IRMS) can differentiate between sources of brain DHA based on differences in natural 13 C enrichment. Mice were fed diets containing either purified ALA or DHA as the sole n-3 PUFA. Extracted lipids were analyzed by CSIA for natural abundance 13 C enrichment. Brain DHA from DHA-fed mice was significantly more enriched (-23.32‰ to -21.92‰) compared with mice on the ALA diet (-28.25‰ to -27.49‰). The measured 13 C enrichment of brain DHA closely resembled the dietary n-3 PUFA source, -21.86‰ and -28.22‰ for DHA and ALA, respectively. The dietary effect on DHA 13 C enrichment was similar in liver and blood fractions. Our results demonstrate the effectiveness of CSIA, at natural 13 C enrichment, to differentiate between the incorporation of preformed or synthesized DHA into the brain and other tissues without the need for tracers. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  20. Mode of action of alginic acid compound in the reduction of gastroesophageal reflux

    International Nuclear Information System (INIS)

    Malmud, L.S.; Charkes, N.D.; Littlefield, J.; Reilley, J.; Stern, H.; Rosenberg, R.; Fisher, R.S.

    1979-01-01

    This study was designed to evaluate quantitatively the mode of action of alginic acid compound (AAC) in the treatment of patients with symptomatic gastroesophageal reflux. Gastroesophageal scintigraphy using an orally administered Tc-99m sulfur colloid solution was used to demonstrate that AAC decreased significantly the gastroesophageal reflux index from (9.9 +- 1.3)% to (6.5 +- 0.8)% (p < 0.05). No alteration of lower esophageal sphincter pressure was observed. After AAC was suitably labeled with Sr-87m, a dual-nuclide scintigraphic technique was used to show that most (< 75%) of the AAC was located in the upper half of the stomach in both normal subjects and patients with gastroesophageal reflux. In those subjects in whom reflux did occur after treatment with AAC, the Sr-87m-AAC refluxed into the esophagus preferentially compared with the liquid containing Tc-99m sulfur colloid. These findings suggest that AAC diminishes gastroesophageal reflux by means of its foaming, floating, and viscous properties

  1. Effect of diluents on the extraction of actinides and nitric acid by bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Rozen, A.M.

    1986-01-01

    The effect of dilutents on extraction by bidentate organophosphorus compounds (diphosphine dioxides, carbamoyl phosphonates, and phosphine oxides) was studied. Figures show the effect of dilutents on the extraction of americium by TOPO and by carbamoylmethylene phosphonate, and the effect of dilutents on the extraction of nitric acid and americium by carbamoylphosphine oxide. Also shown is the effect of dilutents on the extraction of americium by diphenyldioctyl methylenediphosphine dioxide, and the effect of dilutents on the extraction of americium by tetraphenylmethylenediphosphine dioxide. It was concluded that when TBP is added the distribution coefficient of Am increases but the effect of TBP may not be represented by the usual power relationship between the distribution coefficient and the TBP concentration, which would be expected if TBP was found to be very strong but for dilution by DCE it was relatively weak. The observed facts can be explained if it is assumed that TBP reacts with the bridging protons in the complex, which are free for dilution by benzene and are partially occupied when dichlorethane is used

  2. Angelica sinensis (Oliv.) Diels: Influence of Value Chain on Quality Criteria and Marker Compounds Ferulic Acid and Z-Ligustilide.

    Science.gov (United States)

    Giacomelli, Nino; Yongping, Yang; Huber, Franz K; Ankli, Anita; Weckerle, Caroline S

    2017-03-14

    Background: Dang gui (Apiaceae; Angelica sinensis radix) is among the most often used Chinese medicinal plants. However, hardly anything is known about its value chain and its influence on the main marker compounds of the drug. The aim of this study is to investigate the value chain of dang gui in Gansu and Yunnan, and the analysis of the marker compounds ferulic acid and Z-ligustilide concentration in relation to quality criteria such as the production area and size of the roots. Methods: During six months of field research in China, semi-structured interviews with various stakeholders of the value chain were undertaken and plant material was collected. High-performance thin layer chromatography (HPTLC) was used for semi-quantitative analysis of ferulic acid and Z-ligustilide. Results: Small-scale household cultivation prevails and in Gansu-in contrast to Yunnan-the cultivation of dang gui is often the main income source of farmers. Farmers and dealers use size and odor of the root as main quality criteria. For Chinese medicine doctors, Gansu as the production area is the main criterion. Higher amounts of ferulic acid in plant material from Yunnan compared to Gansu were found. Additionally, a negative relation of root length with both ferulic acid and Z-ligustilide as well as head diameter with ferulic acid were found. Conclusions: HPTLC is a valid method for semi-quantitative analysis of the marker compounds of dang gui . However, the two main marker compounds cannot explain why size and smell of the root or production area are seen as quality criteria. This hints at the inherent difficulty to correlate quality notions of medicinal plants with specific chemical compounds. With respect to this, more attention should be paid to quality in terms of cultivation and processing techniques.

  3. Synthesis of model compounds derived from natural clerodane insect antifeedants

    NARCIS (Netherlands)

    Klein Gebbinck, E.A.

    1999-01-01

    Insect antifeedants are compounds with the ability to reduce or inhibit insect feeding without directly killing the insect. Such compounds offer a number of properties that are highly desirable in environmentally friendly crop protection agents. Although the principle of insect control

  4. Effect of dose-rate of gamma irradiation (60Co) on the anti nutritional compounds phytic acid and antitrypsin on soybean (glycine max L.)

    International Nuclear Information System (INIS)

    Tanhindarto, R.P.; Hariyadi, P.; Purnomo, E.H.; Irawati, Z.

    2013-01-01

    An investigation on the effect of gamma irradiation at different dose-rate on the anti-nutritional compounds (phytic acid and antitrypsin) and the color of soybean has been conducted. The purpose of the study was to analyze the influence of the dose-rate on the rate of change of anti-nutritional compounds and color. Samples were irradiated with dose-rates of 1.30; 3.17; 5.71 and 8.82 kGy/hour with irradiation time varied from 0.5 to 55 hours. Phytic acid content and antitrypsin activity, as well as their L α b color values were analyzed. Results showed that a simple first order kinetics model can be used to describe changes in the concentration of the anti-nutritional compounds and color soybeans during the radiation processing. Data indicate that irradiation process at higher dose-rate (shorter time) is more effective in destroying anti-nutritional compounds as compared to that of irradiation process at lower dose-rate (longer time). Furthermore, irradiation process at higher dose-rate (shorter time) also have less detrimental effect on color of the soybean and the resulted soybean flour as compared to that of irradiation process at lower dose-rate (longer time). These findings suggest that irradiation process at a same dose may potentially be optimized by selecting the most appropriate combination of dose-rate and time of irradiation. (author)

  5. Phenolic compounds and fatty acids from acorns (Quercus spp.), the main dietary constituent of free-ranged Iberian pigs.

    Science.gov (United States)

    Cantos, Emma; Espín, Juan Carlos; López-Bote, Clemente; de la Hoz, Lorenzo; Ordóñez, Juan A; Tomás-Barberán, Francisco A

    2003-10-08

    The aim of the present work was to identify and quantify the phenolic compounds and fatty acids in acorns from Quercus ilex, Quercus rotundifolia, and Quercus suber. The concentration of oleic acid was >63% of total fatty acids in all cases, followed by palmitic and linoleic acids at similar concentrations (12-20%). The concentrations of alpha-tocopherol in Q. rotundifolia, Q. ilex, and Q. suber were 19, 31, and 38 mg/kg of dry matter (DM), respectively, whereas the concentrations of gamma-tocopherol were 113, 66, and 74 mg/kg of DM, respectively. Thirty-two different phenolic compounds were distinguished. All of them were gallic acid derivatives, in the form of either galloyl esters of glucose, combinations of galloyl and hexahydroxydiphenoyl esters of glucose, tergallic O- or C-glucosides, or ellagic acid derivatives. Several tergallic acid C-glucosides were also present in the extracts obtained from Q. suber. Acorns from Q. ilex and Q. rotundifolia showed similar polyphenol patterns mainly with gallic acid-like spectra. Chromatograms of Q. suber showed mainly polyphenols with ellagic acid-like spectra. Valoneic acid dilactone was especially abundant in Q. suber skin. The contribution of skin to the total phenolics of the acorn was relatively small in Q. rotundifolia and Q. ilex but relatively high in Q. suber. Skin extracts from Q. suber, Q. rotundifolia, and Q. ilex showed 1.3, 1.4, and 1.0 antioxidant efficiencies, respectively (compared to that of butylhydroxyanisole). Endosperm extracts showed lower capacity to prevent lipid peroxidation than skin extracts.

  6. The use of quantum chemically derived descriptors for QSAR modelling of reductive dehalogenation of aromatic compounds

    NARCIS (Netherlands)

    Rorije E; Richter J; Peijnenburg WJGM; ECO; IHE Delft

    1994-01-01

    In this study, quantum-chemically derived parameters are developed for a limited number of halogenated aromatic compounds to model the anaerobic reductive dehalogenation reaction rate constants of these compounds. It is shown that due to the heterogeneity of the set of compounds used, no single

  7. Crystal structures of two 1:2 dihydrate compounds of chloranilic acid with 2-carboxypyridine and 2-carboxyquinoline

    Directory of Open Access Journals (Sweden)

    Kazuma Gotoh

    2017-12-01

    Full Text Available The crystal structure of the 1:2 dihydrate compound of chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone with 2-carboxypyridine (another common name: picolinic acid; systematic name: pyridine-2-carboxylic acid, namely, 2C6H5.5NO20.5+·C6HCl2O4−·2H2O, (I, has been determined at 180 K, and the structure of the 1:2 dihydrate compound of chloranilic acid with 2-carboxyquinoline (another common name: quinaldic acid; systematic name: quinoline-2-carboxylic acid, namely, 2C10H7NO2·C6H2Cl2O4·2H2O, (II, has been redetermined at 200 K. This determination presents a higher precision crystal structure than the previously published structure [Marfo-Owusu & Thompson (2014. X-ray Struct. Anal. Online, 30, 55–56]. Compound (I was analysed as a disordered structure over two states, viz. salt and co-crystal. The salt is bis(2-carboxypyridinium chloranilate dihydrate, 2C6H6NO2+·C6Cl2O42−·2H2O, and the co-crystal is bis(pyridinium-2-carboxylate chloranilic acid dihydrate, 2C6H5NO2·C6H2Cl2O4·2H2O, including zwitterionic 2-carboxypyridine. In both salt and co-crystal, the water molecule links the chloranilic acid and 2-carboxypyridine molecules through O—H...O and N—H...O hydrogen bonds. The 2-carboxypyridine molecules are connected into a head-to-head inversion dimer by a short O—H...O hydrogen bond, in which the H atom is disordered over two positions. Compound (II is a 1:2 dihydrate co-crystal of chloranilic acid and zwitterionic 2-carboxyquinoline. The water molecule links the chloranilic acid and 2-carboxyquinoline molecules through O—H...O hydrogen bonds. The 2-carboxyquinoline molecules are connected into a head-to-tail inversion dimer by a pair of N—H...O hydrogen bonds.

  8. Compound-Specific Isotopic Analysis of Meteoritic Amino Acids as a Tool for Evaluating Potential Formation Pathways

    Science.gov (United States)

    Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael C.; Charnley, Steven B.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Measurements of stable hydrogen, carbon, and nitrogen isotopic ratios (delta D, delta C-13, delta N-15) of organic compounds can reveal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may point towards the most likely of these proposed pathways. The technique of gas chromatography coupled with mass spectrometry and isotope ratio mass spectrometry provides compound-specific structural and isotopic information from a single splitless injection, enhancing the amount of information gained from small amounts of precious samples such as carbonaceous chondrites. We have applied this technique to measure the compound-specific C, N, and H isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites. We are using these measurements to evaluate predictions of expected isotopic enrichments from potential formation pathways and environments, leading to a better understanding of the origin of these compounds.

  9. Influence of Fruit Ripening on Color, Organic Acid Contents, Capsaicinoids, Aroma Compounds, and Antioxidant Capacity of Shimatogarashi (Capsicum frutescens).

    Science.gov (United States)

    Manikharda; Takahashi, Makoto; Arakaki, Mika; Yonamine, Kaoru; Hashimoto, Fumio; Takara, Kensaku; Wada, Koji

    2018-01-01

    Shimatogarashi (Capsicum frutescens) is a typical chili pepper domesticated in southern Japan. Important traits of Shimatogarashi peppers, such as color; proportion of organic acids, capsaicinoids, and aromatic compounds; and antioxidant activity in three stages of maturity (green (immature), orange (turning), and red (mature) stages) were characterized. The results indicated that the concentration of organic acids, including ascorbic, citric, and malic acid, increased during ripening. In addition, the amount of capsaicinoids, which are responsible for the pungent taste of chili peppers, increased as the fruit matured to the orange and red stages. The volatile compound profile of Shimatogarashi was dominated by the presence of esters, which mainly contributed to fruity notes. The total amount of volatile compounds analyzed by gas chromatography-headspace solid-phase microextraction (GC-HS-SPME), especially esters, decreased as the fruit changed in color from green to red. This was in contrast to the amount of terpenoids, especially limonene, which increased at the red stage, denoting a change in flavor from fruity to a more citrus-like aroma. Based on the total phenolic content (TPC), the oxygen radical absorbance capacity (ORAC) and the diphenylpicrylhydrazyl (DPPH) free radical method, the antioxidant capacity of Shimatogarashi showed an increase at the mature red stage. However, while the red stage showed higher pungency and antioxidant capacity as well as an attractive color, the results of aromatic compound analysis revealed that the immature green stage had the advantages of having pleasant fruity smell, making it suitable for use in condiments.

  10. Antibacterial activity of sphagnum acid and other phenolic compounds found in Sphagnum papillosum against food-borne bacteria.

    Science.gov (United States)

    Mellegård, H; Stalheim, T; Hormazabal, V; Granum, P E; Hardy, S P

    2009-07-01

    To identify the phenolic compounds in the leaves of Sphagnum papillosum and examine their antibacterial activity at pH appropriate for the undissociated forms. Bacterial counts of overnight cultures showed that whilst growth of Staphylococcus aureus 50084 was impaired in the presence of milled leaves, the phenol-free fraction of holocellulose of S. papillosum had no bacteriostatic effect. Liquid chromatography-mass spectrometry analysis of an acetone-methanol extract of the leaves detected eight phenolic compounds. Antibacterial activity of the four dominating phenols specific to Sphagnum leaves, when assessed in vitro as minimal inhibitory concentrations (MICs), were generally >2.5 mg ml(-1). MIC values of the Sphagnum-specific compound 'sphagnum acid' [p-hydroxy-beta-(carboxymethyl)-cinnamic acid] were >5 mg ml(-1). No synergistic or antagonistic effects of the four dominating phenols were detected in plate assays. Sphagnum-derived phenolics exhibit antibacterial activity in vitro only at concentrations far in excess of those found in the leaves. We have both identified the phenolic compounds in S. papillosum and assessed their antibacterial activity. Our data indicate that phenolic compounds in isolation are not potent antibacterial agents and we question their potency against food-borne pathogens.

  11. Telluro amino acids-synthesis, characterization and properties of a new and potentially useful class of compounds

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.; Ambrose, K.R.; Callahan, A.P.

    1978-01-01

    The Te-123m nuclide emits 159 keV photons suggesting that agents labeled with this nuclide would be attractive candidates for tissue imaging. Amino acids labeled with Te-123m are of particular interest since some of these compounds would be isosteric with the sulfur analogs and might behave similarly in vivo. Such agents could possibly be useful for pancreatic imaging and for other biomedical applications. The goal of this investigation was to develop a general chemical method for the preparation of telluro amino acids. Attempts by other workers to prepare such compounds by microbiological methods have been unsuccessful. Since telluro amino acids were unknown prior to our studies we attempted the synthesis of a representative member of this class of compounds by several routes. Two general approaches were considered which involved either the introduction of an (organo telluro) reagent into a substrate that contained the protected -CH(NH 2 )COOH moiety or introduction of the reagent into a substrate that could subsequently be converted to the α-amino acid after the coupling step

  12. ImprimatinC1, a novel plant immune-priming compound, functions as a partial agonist of salicylic acid.

    Science.gov (United States)

    Noutoshi, Yoshiteru; Jikumaru, Yusuke; Kamiya, Yuji; Shirasu, Ken

    2012-01-01

    Plant activators are agrochemicals that protect crops from pathogens. They confer durable resistance to a broad range of diseases by activating intrinsic immune mechanisms in plants. To obtain leads regarding useful compounds, we have screened a chemical library using an established method that allows selective identification of immune-priming compounds. Here, we report the characterisation of one of the isolated chemicals, imprimatinC1, and its structural derivative imprimatinC2. ImprimatinC1 functions as a weak analogue of salicylic acid (SA) and activates the expression of defence-related genes. However, it lacks antagonistic activity toward jasmonic acid. Structure-activity relationship analysis suggests that imprimatinC1 and C2 can be metabolised to 4-chlorobenzoic acid and 3,4-chlorobenzoic acid, respectively, to function in Arabidopsis. We also found that imprimatinC1 and C2 and their potential functional metabolites acted as partial agonists of SA. Thus, imprimatinC compounds could be useful tools for dissecting SA-dependent signal transduction pathways.

  13. Mathematical modeling of acid-base physiology.

    Science.gov (United States)

    Occhipinti, Rossana; Boron, Walter F

    2015-01-01

    pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3(-), [Formula: see text] ) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cells-which to our knowledge is the first one capable of handling a multitude of buffer reactions-that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3(-) influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Separation of rare earths by means of acid organophosphorous compounds. Structure-activity study by molecular simulation

    International Nuclear Information System (INIS)

    Fourcot, Fabrice

    1991-01-01

    The increasing number of industrial applications of rare earths has resulted in an increased demand in purified rare earths whereas their separation is difficult due to their high chemical similarity. The search for a better separation leads to the search for more selective extraction agents. Organophosphorous compounds appear to be the most selective. As the search for new extraction agents resulting in high lanthanide extraction efficiency or in a better selectivity between rare earths has been mainly empiric, this research thesis aims at developing a molecular simulation method which allows the number of molecules to be synthesized and tested to be reduced. After having briefly recalled general knowledge on liquid-liquid extraction and on rare earths, and described calculation methods (quantum methods, methods based on molecular mechanics, conformational analysis, methods of charge calculation), the author proposes a critical review of literature related to rare earth liquid-liquid extraction by organophosphorous acids with respect to the used extraction agent. The molecular modelling issue is then addressed by describing ways to apply it to extraction problems, faced problems, brought solutions and obtained results

  15. Investigation of tritium removal by means of organic compounds. Catalytic hydrogenation (tritiation) of linoleic acid

    International Nuclear Information System (INIS)

    El-Sharnouby, A.; Weichselgartner, H.

    1984-11-01

    In the presence of noble-metal catalysts unsaturated fatty acids such as eruic acid and linoleic acid capture hydrogen (and tritium) quantitatively. The hydrogenation reaction of eruic acid has already been reported. The experimental results of the reaction of hydrogen (and tritium) with linoleic acid are now discussed in this paper. Obviously, the use of linoleic acid shows some advantages compared with eruic acid: - the hydrogenation reaction is faster, - linoleic acid is liquid, so that the choice of additional solvents is easier, and - linoleic acid is a more or less cheap natural product, which is available from a series of seeds, so that the cost of a technical tritium removal plant is not increased by the basic chemical material. (orig.)

  16. Formation of emerging DBPs from the chlorination and chloramination of seawater algal organic matter and related model compounds

    KAUST Repository

    Nihemaiti, Maolida

    2014-05-01

    Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the

  17. Trimethylamine (fishy odor) adsorption by biomaterials: effect of fatty acids, alkanes, and aromatic compounds in waxes.

    Science.gov (United States)

    Boraphech, Phattara; Thiravetyan, Paitip

    2015-03-02

    Thirteen plant leaf materials were selected to be applied as dried biomaterial adsorbents for polar gaseous trimethylamine (TMA) adsorption. Biomaterial adsorbents were efficient in adsorbing gaseous TMA up to 100% of total TMA (100 ppm) within 24 h. Sansevieria trifasciata is the most effective plant leaf material while Plerocarpus indicus was the least effective in TMA adsorption. Activated carbon (AC) was found to be lower potential adsorbent to adsorb TMA when compared to biomaterial adsorbents. As adsorption data, the Langmuir isotherm supported that the gaseous TMA adsorbed monolayer on the adsorbent surface and was followed pseudo-second order kinetic model. Wax extracted from plant leaf could also adsorb gaseous TMA up to 69% of total TMA within 24 h. Another 27-63% of TMA was adsorbed by cellulose and lignin that naturally occur in high amounts in plant leaf. Subsequently, the composition appearing in biomaterial wax showed a large quantity of short-chain fatty acids (≤C18) especially octadecanoic acid (C18), and short-chain alkanes (C12-C18) as well as total aromatic components dominated in the wax, which affected TMA adsorption. Hence, it has been demonstrated that plant biomaterial is a superior biosorbent for TMA removal.

  18. Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L. Grape Berries

    Directory of Open Access Journals (Sweden)

    Yan-Lun Ju

    2016-10-01

    Full Text Available The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA and methyl jasmonate (MeJA on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC and individual anthocyanins. Lipoxygenase (LOX activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

  19. Catalytic activity of laminated compounds of graphite with transitions metals in decomposition of alcohols and formic acid

    International Nuclear Information System (INIS)

    Novikov, Yu.N.; Lapkina, N.D.; Vol'pin, M.E.

    1976-01-01

    The catalytic activity is studied of laminated graphite compounds with Fe, Co, Ni, Cu, Mo, W and Mn both in the reduced and oxidized forms in gas phase decomposition reactions of isopropyl, n-butyl, cyclohexyl, and 4-tret-butylcyclohexyl alcohols, and also formic acid. All the catalysts are shown to be active in the reactions where isopropyl and n-butyl alcohols undergo decomposition. The laminated compounds of graphite with Co and Ni both in the oxidized and reduction form are the most active catalysts of the selective decomposition of alcohols to aldehydes and ketones, and also formic acid to CO 2 and H 2 . The kinetics of a number of reactions is found to obey the second order equation with allowance made for the system volume

  20. Helleborus purpurascens—Amino Acid and Peptide Analysis Linked to the Chemical and Antiproliferative Properties of the Extracted Compounds

    Directory of Open Access Journals (Sweden)

    Adina-Elena Segneanu

    2015-12-01

    Full Text Available There is a strong drive worldwide to discover and exploit the therapeutic potential of a large variety of plants. In this work, an alcoholic extract of Helleborus purpurascens (family Ranunculaceae was investigated for the identification of amino acids and peptides with putative antiproliferative effects. In our work, a separation strategy was developed using solvents of different polarity in order to obtain active compounds. Biochemical components were characterized through spectroscopic (mass spectroscopy and chromatographic techniques (RP-HPLC and GC-MS. The biological activity of the obtained fractions was investigated in terms of their antiproliferative effects on HeLa cells. Through this study, we report an efficient separation of bioactive compounds (amino acids and peptides from a plant extract dependent on solvent polarity, affording fractions with unaffected antiproliferative activities. Moreover, the two biologically tested fractions exerted a major antiproliferative effect, thereby suggesting potential anticancer therapeutic activity.

  1. Helleborus purpurascens-Amino Acid and Peptide Analysis Linked to the Chemical and Antiproliferative Properties of the Extracted Compounds.

    Science.gov (United States)

    Segneanu, Adina-Elena; Grozescu, Ioan; Cziple, Florentina; Berki, Daniel; Damian, Daniel; Niculite, Cristina Mariana; Florea, Alexandru; Leabu, Mircea

    2015-12-11

    There is a strong drive worldwide to discover and exploit the therapeutic potential of a large variety of plants. In this work, an alcoholic extract of Helleborus purpurascens (family Ranunculaceae) was investigated for the identification of amino acids and peptides with putative antiproliferative effects. In our work, a separation strategy was developed using solvents of different polarity in order to obtain active compounds. Biochemical components were characterized through spectroscopic (mass spectroscopy) and chromatographic techniques (RP-HPLC and GC-MS). The biological activity of the obtained fractions was investigated in terms of their antiproliferative effects on HeLa cells. Through this study, we report an efficient separation of bioactive compounds (amino acids and peptides) from a plant extract dependent on solvent polarity, affording fractions with unaffected antiproliferative activities. Moreover, the two biologically tested fractions exerted a major antiproliferative effect, thereby suggesting potential anticancer therapeutic activity.

  2. Synthesis of 6-Phosphofructose Aspartic Acid and Some Related Amadori Compounds

    OpenAIRE

    Hansen, Alexandar L.; Behrman, Edward J.

    2016-01-01

    We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid.

  3. A novel isoindoline, porritoxin sulfonic acid, from Alternaria porri and the structure-phytotoxicity correlation of its related compounds.

    Science.gov (United States)

    Horiuchi, Masayuki; Ohnishi, Keiichiro; Iwase, Noriyasu; Nakajima, Yoshikazu; Tounai, Kenji; Yamashita, Masakazu; Yamada, Yasumasa

    2003-07-01

    Novel zinniol-related compound 3, named porritoxin sulfonic acid, with an isoindoline skeleton was isolated from the culture liquid of Alternaria porri. The structure was determined to be 2-(2"-sulfoethyl)-4-methoxy-5-methyl-6-(3'-methyl-2'-butenyloxy)-2,3-dihydro-1H-isoindol-1-one. The phytotoxic activities of three isoindolines (1-3) were evaluated in a seedling-growth assay against stone leek and lettuce.

  4. Transformations of Phenolic Compounds in an in vitro Model Simulating the Human Alimentary Tract

    Directory of Open Access Journals (Sweden)

    Aleksandra Duda-Chodak

    2009-01-01

    Full Text Available The aim of this work is to establish the antioxidant properties of polyphenolic compounds of selected fruits before and after their transformations during digestion. The experiment was conducted in in vitro conditions on a set of dialysis membranes which simulated the human digestive tract. Apples of the Šampion, Malinowka and Golden Delicious cultivars, black chokeberry, banana, Wegierka zwykla blue plum, melon and Lukasowka pear were chosen for examination. It was found that compounds obtained after simulated digestion of chokeberries, pears and bananas showed lower antioxidant potential than fresh fruits, while the opposite results were obtained for apples and plums. All dialysates obtained after digestion were characterized by lower content of total polyphenols in comparison with raw material (fresh fruits. It was found that the polyphenols were hydrolyzed, especially glycosides of quercetin and cyanidin. Phenolic acids and cyanidin were characterized by low availability for absorption, whereas catechin and quercetin had a very high level of accessibility in the model small intestine.

  5. Photosynthetic pigments and model compounds studied by pulse radiolysis

    International Nuclear Information System (INIS)

    Jensen, N.-H.

    1980-05-01

    The photosynthetic pigments chlorophyll a and alltrans-β-carotene as well as the quinone model compound duroquinone have been studied in solution by pulse radiolysis combined with time-resolved absorption and resonance Raman spectroscopy. In benzene solution the excited triplet states of the subtrates were produced either directly in the case of duroquinone or by triplet energy transfer from triplet naphthalene in the case of chlorophyll a and β-carotene. All relevant rate constants involved in the reactions of the excited states in benzene were determined, including i) the rate constants for energy transfer from triplet naphthalene to chlorophyll a with k = (3.6+-0.6).10 9 M -1 s -1 and β-carotene with k = (10.7+-1.2).10 9 M -1 s -1 ii) the rate constants of triplet annihilation of chlorophyll a: (1.4+-0.3).10 9 M -1 s -1 , β-carotene: (3.6+-0.4).10 9 M -1 s -1 , duroquinone: (3.0+-0.6).10 9 M -1 s -1 . For β-carotene it is suggested that triplet-triplet annihilation produces the optically forbidden excited 1 Asub(g) state. The first-order components of the triplet decays were strongly dependent upon irradiation dose in the case of naphthalene and duroquinone but apparently only slightly dependent on or independent or irradiation dose in the case of chlorophyll a and β-carotene. Apparent bimolecular rate constants for triplet quenching by radiolytically produced free radicals are determined. The triplet state of duroquinone is quenched by ground state duroquinone with a rate constant of (1.2+-0.3).10 6 M -1 s -1 . The excited triplet state of all-trans-β-carotene has been investigated by time-resolved resonance Raman spectroscopy. Six transient Raman bands at 965 cm -1 , 1009 cm -1 , 1125 cm -1 , 1188 cm -1 , 1236 cm -1 and 1496 cm -1 were observed. The spectra suggest that the C = C band order is decreased and that the molecule may be substantially twisted, presumably at the 15,15 1 band, in the triplet state. The radical anion of chlorophyll a with

  6. Organic acid compounds in root exudation of Moso Bamboo (Phyllostachys pubescens) and its bioactivity as affected by heavy metals.

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Liu, Chen; Zhong, Bin; Guo, Hua; He, Lizhi; Liu, Dan

    2016-10-01

    Moso bamboo (Phyllostachys pubescens) has great potential as phytoremediation material in soil contaminated by heavy metals. A hydroponics experiment was conducted to determine organic acid compounds of root exudates of lead- (Pb), zinc- (Zn), copper- (Cu), and cadmium (Cd)-tolerant of Moso bamboo. Plants were grown in nutrients solution which included Pb, Zn, Cu, and Cd applied as Pb(NO 3 ) 2 (200 μM), ZnSO 4 ·7H 2 O (100 μM), CuSO 4 ·5H 2 O (25 μM), and CdCl 2 (10 μM), respectively. Oxalic acid and malic acid were detected in all treatments. Lactic acid was observed in Cu, Cd, and control treatments. The oxalic was the main organic acid exudated by Moso bamboo. In the sand culture experiment, the Moso bamboo significantly activated carbonate heavy metals under activation of roots. The concentration of water-soluble metals (except Pb) in sand were significantly increased as compared with control. Organic acids (1 mM mixed) were used due to its effect on the soil adsorption of heavy metals. After adding mixed organic acids, the Cu and Zn sorption capacity in soils was decreased markedly compared with enhanced Pb and Cd sorption capacity in soils. The sorption was analyzed using Langmuir and Freundlich equations with R 2 values that ranged from 0.956 to 0.999 and 0.919 to 0.997, respectively.

  7. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  8. Characterization and Influence of Green Synthesis of Nano-Sized Zinc Complex with 5-Aminolevulinic Acid on Bioactive Compounds of Aniseed.

    Science.gov (United States)

    Tavallali, Vahid; Rahmati, Sadegh; Rowshan, Vahid

    2017-11-01

    A new water soluble zinc-aminolevulinic acid nano complex (n[Zn(ALA) 2 ]), which was characterized by TEM, IR, and EDX spectra, has been prepared via sonochemical method under green conditions in water. In the current study, the effectiveness of foliar Zn amendment using synthetic Zn-ALA nano complex, as a new introduced Zn-fertilizer here, was evaluated. As the model plant, Pimpinella anisum, the most valuable spice and medicinal plant grown in warm regions, was used. By using zinc nano complex, further twenty compounds were obtained in the essential oil of anise plants. Application of 0.2% (w/v) Zn-ALA nano complex increased the levels of (E)-anethole, β-bisabolene, germacrene D, methyl chavicol, and α-zingiberene in the essential oil. Nano Zn complex at the rate of 0.2% induced considerable high phenolic compounds and zinc content of shoots and seeds. Chlorogenic acid had the highest level between four detected phenolic compounds. The maximum antioxidant activity was monitored through the application of Zn nano complex. According to the results, nanoscale nutrients can be provided with further decreased doses for medicinal plants. Using Zn-ALA nano complex is a new and efficient method to improve the pharmaceutical and food properties of anise plants. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  9. Testing antidepressant compounds in a neuropsychological model of drug action

    NARCIS (Netherlands)

    Cerit, Hilal

    2015-01-01

    Although much research effort has been put into the development of new antidepressant drugs, the process of developing a drug often fails at the stage of large randomized controlled trials (RCTs) in which an initially promising compound appears to lack efficacy after all. Several experimental

  10. Evidence for dynamic behavior of O2 in oxy-heme model compounds

    International Nuclear Information System (INIS)

    Montiel-Montoya, R.; Bill, E.; Trautwein, A.X.; Winkler, H.

    1986-01-01

    The authors have performed Moessbauer studies on several oxy-heme model compounds, and for two of them they have also derived the three dimensional structure from X-ray studies. The X-ray structure analysis of these model compounds provides the information that O 2 occupies three different sites in one and only two sites in the other. (Auth.)

  11. Modeling the degradation kinetics of ascorbic acid.

    Science.gov (United States)

    Peleg, Micha; Normand, Mark D; Dixon, William R; Goulette, Timothy R

    2018-06-13

    Most published reports on ascorbic acid (AA) degradation during food storage and heat preservation suggest that it follows first-order kinetics. Deviations from this pattern include Weibullian decay, and exponential drop approaching finite nonzero retention. Almost invariably, the degradation rate constant's temperature-dependence followed the Arrhenius equation, and hence the simpler exponential model too. A formula and freely downloadable interactive Wolfram Demonstration to convert the Arrhenius model's energy of activation, E a , to the exponential model's c parameter, or vice versa, are provided. The AA's isothermal and non-isothermal degradation can be simulated with freely downloadable interactive Wolfram Demonstrations in which the model's parameters can be entered and modified by moving sliders on the screen. Where the degradation is known a priori to follow first or other fixed order kinetics, one can use the endpoints method, and in principle the successive points method too, to estimate the reaction's kinetic parameters from considerably fewer AA concentration determinations than in the traditional manner. Freeware to do the calculations by either method has been recently made available on the Internet. Once obtained in this way, the kinetic parameters can be used to reconstruct the entire degradation curves and predict those at different temperature profiles, isothermal or dynamic. Comparison of the predicted concentration ratios with experimental ones offers a way to validate or refute the kinetic model and the assumptions on which it is based.

  12. Ionic liquid [OMIm][OAc] directly inducing oxidation cleavage of the β-O-4 bond of lignin model compounds.

    Science.gov (United States)

    Yang, Yingying; Fan, Honglei; Meng, Qinglei; Zhang, Zhaofu; Yang, Guanying; Han, Buxing

    2017-08-03

    We explored the oxidation reactions of lignin model compounds directly induced by ionic liquids under metal-free conditions. In this work, it was found that ionic liquid 1-octyl-3-methylimidazolium acetate as a solvent could promote the aerobic oxidation of lignin model compound 2-phenoxyacetophenone (1) and the yields of phenol and benzoic acid from 1 could be as high as 96% and 86%, respectively. A possible reaction pathway was proposed based on a series of control experiments. An acetate anion from the ionic liquid attacked the hydrogen from the β-carbon thereby inducing the cleavage of the C-O bond of the aromatic ether. Furthermore, it was found that 2-(2-methoxyphenoxy)-1-phenylethanone (4) with a methoxyl group could also be transformed into aromatic products in this simple reaction system and the yields of phenol and benzoic acid from 4 could be as high as 98% and 85%, respectively. This work provides a simple way for efficient transformation of lignin model compounds.

  13. Wild Roman chamomile extracts and phenolic compounds: enzymatic assays and molecular modelling studies with VEGFR-2 tyrosine kinase.

    Science.gov (United States)

    Guimarães, Rafaela; Calhelha, Ricardo C; Froufe, Hugo J C; Abreu, Rui M V; Carvalho, Ana Maria; Queiroz, Maria João R P; Ferreira, Isabel C F R

    2016-01-01

    Angiogenesis is a process by which new blood vessels are formed from the pre-existing vasculature, and it is a key process that leads to tumour development. Some studies have recognized phenolic compounds as chemopreventive agents; flavonoids, in particular, seem to suppress the growth of tumor cells modifying the cell cycle. Herein, the antiangiogenic activity of Roman chamomile (Chamaemelum nobile L.) extracts (methanolic extract and infusion) and the main phenolic compounds present (apigenin, apigenin-7-O-glucoside, caffeic acid, chlorogenic acid, luteolin, and luteolin-7-O-glucoside) was evaluated through enzymatic assays using the tyrosine kinase intracellular domain of the Vascular Endothelium Growth Factor Receptor-2 (VEGFR-2), which is a transmembrane receptor expressed fundamentally in endothelial cells involved in angiogenesis, and molecular modelling studies. The methanolic extract showed a lower IC50 value (concentration that provided 50% of VEGFR-2 inhibition) than the infusion, 269 and 301 μg mL(-1), respectively. Regarding phenolic compounds, luteolin and apigenin showed the highest capacity to inhibit the phosphorylation of VEGFR-2, leading us to believe that these compounds are involved in the activity revealed by the methanolic extract.

  14. Speciation of chromium compounds from humic acid-zeolite Y to an ionic liquid during extraction.

    Science.gov (United States)

    Huang, Hsin-Liang; Wei, Yu Jhe

    2018-03-01

    By synchrotron X-ray absorption spectroscopy, chemical structures of hexavalent chromium (Cr(VI))/trivalent chromium (Cr(III)) adsorbed on humic acid (HA)-zeolite Y and extracted in an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate ([C 4 mim][BF 4 ])) have been studied. By combining the competitive adsorption results and reduction of Cr(VI)-HA with the carboxyl groups of HA, Cr(III)-HA (58%) was shown to be the major compound in HA-zeolite Y using synchrotron X-ray absorption near-edge structure (XANES) spectroscopy. In an ionic liquid phase, the reduction of Cr(VI)-HA to Cr(III)-HA and the desorption of Cr(III) from HA were caused by [C 4 mim][BF 4 ]. The 9 F nuclear magnetic resonance (NMR) spectra show that the perturbation of the [C 4 mim][BF 4 ] anion was affected by the extractable chromium species. The formation of a Cr(III) ion affected the increase in the bond distance for the 1st shell CrO of the chromium species in [C 4 mim][BF 4 ] using extended X-ray absorption fine structure (EXAFS) spectroscopy. The changes in the non-extractable chromium species remaining in HA-zeolite Y were also caused by [C 4 mim][BF 4 ] during extraction. The desorption of the absorbed Cr(III) on HA and zeolite Y was observed to form Cr(III) ions. As the percentage of Cr(III) ions remaining in HA-zeolite Y increased, a slightly greater bond distance for CrO was found at 2.01 Å. The enhanced reduction of Cr(VI)-HA and desorption of Cr(III) adsorbed on the HA and zeolite Y to form Cr(III) ions were affected by [C 4 mim][BF 4 ]. Increased mobility of Cr(III) in the simulated soil can promote the migration of Cr(III) ions into the H 2 O during soil washing for remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Chemical Reductive Transformations of Synthetic Organic Compounds. Probe Compound Studies and Mechanistic Modeling

    National Research Council Canada - National Science Library

    Peyton, Gary

    2001-01-01

    .... A kinetic model that was previously developed to describe the results of batch AOP treatment by H2O2/UV did not give satisfactory predictive results obtained when extended to describe flow experiments...

  16. Modelling of the Kinetics of Sulfure Compounds in Desulfurisation Processes Based on Industry Data of Plant

    Directory of Open Access Journals (Sweden)

    Krivtcova Nadezhda

    2016-01-01

    Full Text Available Modelling of sulfur compounds kinetics was performed, including kinetics of benzothiophene and dibenzothiophene homologues. Modelling is based on experimental data obtained from monitoring of industrial hydrotreating set. Obtained results include kinetic parameters of reactions.

  17. Modelling of the Kinetics of Sulfure Compounds in Desulfurisation Processes Based on Industry Data of Plant

    OpenAIRE

    Krivtsova, Nadezhda Igorevna; Tataurshikov, A.; Kotkova, Elena

    2016-01-01

    Modelling of sulfur compounds kinetics was performed, including kinetics of benzothiophene and dibenzothiophene homologues. Modelling is based on experimental data obtained from monitoring of industrial hydrotreating set. Obtained results include kinetic parameters of reactions.

  18. [Effects of Aptamer-siRNA Nucleic Acid Compound on Growth and Apoptosis in Myeloid Leukemia Cell Line K562].

    Science.gov (United States)

    Ping, Juan; Shen, Zhi-Hui; Wang, Bao-Quan; Zhao, Na; Li, Rui; Li, Mian; Pang, Xiao-Bin; Chen, Chuan-Bo

    2015-04-01

    To explore the effects of aptamer-siRNA nucleic acid compound on growth and apoptosis in myeloid leukemia cell line K562. the changes of cellular morphology and structure were observed by using fluorescence microscope, laser confocal microscope, JEM-4000EX transmission electron microscopy; MTT assay were performed to evaluate the sensibility of K562 cells to aptamer-siRNA compound, the apoptosis was detected by DNA gel electro-phoresis. The remarkably changes of morphology and structure of K562 cells treated with 200 µmol/L aptamer-siRNA were observed under fluorescence microscopy and electromicroscopy. As compared with control, the aptamer-siRNA compound showed more inhibitory effect on K562 cells and there was significant difference (Pcompound for K562 cells was 150 µmol/L. According to agarose gel electrophoresis observation, when the aptamer-siRNA compound showed effect on K562 cells, the typical DNA lader could be observed. The aptamer-siRNA compound can significantly induce K562 cell apoptosis, and provide reference for gene therapy of patients with chronic myelocytic lenkemia.

  19. Aromatic Amino Acid-Derived Compounds Induce Morphological Changes and Modulate the Cell Growth of Wine Yeast Species.

    Science.gov (United States)

    González, Beatriz; Vázquez, Jennifer; Cullen, Paul J; Mas, Albert; Beltran, Gemma; Torija, María-Jesús

    2018-01-01

    Yeasts secrete a large diversity of compounds during alcoholic fermentation, which affect growth rates and developmental processes, like filamentous growth. Several compounds are produced during aromatic amino acid metabolism, including aromatic alcohols, serotonin, melatonin, and tryptamine. We evaluated the effects of these compounds on growth parameters in 16 different wine yeasts, including non- Saccharomyces wine strains, for which the effects of these compounds have not been well-defined. Serotonin, tryptamine, and tryptophol negatively influenced yeast growth, whereas phenylethanol and tyrosol specifically affected non- Saccharomyces strains. The effects of the aromatic alcohols were observed at concentrations commonly found in wines, suggesting a possible role in microbial interaction during wine fermentation. Additionally, we demonstrated that aromatic alcohols and ethanol are able to affect invasive and pseudohyphal growth in a manner dependent on nutrient availability. Some of these compounds showed strain-specific effects. These findings add to the understanding of the fermentation process and illustrate the diversity of metabolic communication that may occur among related species during metabolic processes.

  20. Catalytic Hydrodeoxygenation of Bio-oil Model Compounds over Pt/HY Catalyst

    Science.gov (United States)

    Lee, Heejin; Kim, Hannah; Yu, Mi Jin; Ko, Chang Hyun; Jeon, Jong-Ki; Jae, Jungho; Park, Sung Hoon; Jung, Sang-Chul; Park, Young-Kwon

    2016-06-01

    The hydrodeoxygenation of a model compound of lignin-derived bio-oil, guaiacol, which can be obtained from the pyrolysis of biomass to bio-oil, has attracted considerable research attention because of its huge potential as a substitute for conventional fuels. In this study, platinum-loaded HY zeolites (Pt/HY) with different Si/Al molar ratios were used as catalysts for the hydrodeoxygenation of guaiacol, anisole, veratrole, and phenol to a range of hydrocarbons, such as cyclohexane. The cyclohexane (major product) yield increased with increasing number of acid sites. To produce bio-oil with the maximum level of cyclohexane and alkylated cyclohexanes, which would be suitable as a substitute for conventional transportation fuels, the Si/Al molar ratio should be optimized to balance the Pt particle-induced hydrogenation with acid site-induced methyl group transfer. The fuel properties of real bio-oil derived from the fast pyrolysis of cork oak was improved using the Pt/HY catalyst.

  1. Distribution of 14C-activity among the organic acids in the Satsuma mandarin fruits fed with 14C-compounds

    International Nuclear Information System (INIS)

    Kubota, Shuji; Akao, Shoichiro; Hayashida, Michito.

    1978-01-01

    1. Twenty four hours after 14 CO 2 feeding to the leaves, malic acid had the highest level of total and specific radioactivity among the organic acids extracted from the juice vesicles, and citric acid had the second highest total activity. An unidentified acid compound had a relatively high activity. 2. Pyruvic acid-2- 14 C was fed as a substrate for acid formation to the one young fruit on a shoot, and NaH 14 CO 3 was fed as a source of carbon-dioxide to the other young fruit through the pedicel. After three hours of pyruvic acid feeding, malic acid, citric acid and aspartic acid were the major labelled compounds in the vesicles. Then, a marked increase and redistribution of activity in acids took place with time, and the levels of total and specific activity in citric acid increased steadily. The sorts of labelled compounds into which activity was incorporated from NaH 14 CO 3 were essentially similar to those in pyruvic acid-2- 14 C feeding. 3. These results seem to support the theory that the dark fixation of carbon-dioxide plays an important role in the synthesis of the organic acids in citrus fruit vesicles. (auth.)

  2. Effect of high hydrostatic pressure on phenolic compounds, ascorbic acid and antioxidant activity in cashew apple juice

    Science.gov (United States)

    Queiroz, C.; Moreira, C. F. F.; Lavinas, F. C.; Lopes, M. L. M.; Fialho, E.; Valente-Mesquita, V. L.

    2010-12-01

    The cashew apple is native to Brazil, but there is insufficient information regarding the nutritional properties of this fruit. The objective of this study was to evaluate the impact of high pressure processing (HPP) at room temperature (25 °C) on phenolic compound and ascorbic acid contents and antioxidant capacity of cashew apple juice. This study showed that HPP at 250 or 400 MPa for 3, 5 and 7 min did not change pH, acidity, total soluble solids, ascorbic acid or hydrolysable polyphenol contents. However, juice pressurized for 3 and 5 min showed higher soluble polyphenol contents. Antioxidant capacity, measured by the ferric-reducing antioxidant power method, was not altered by HPP, but when treated at 250 MPa for 3 min, it resulted in an increased value when 2,2-diphenyl-1-picrylhydrazyl was used. These data demonstrate that HPP can be used in the food industry for the generation of products with higher nutritional quality.

  3. Influence of variation in mobile phase pH and solute pK(a) with the change of organic modifier fraction on QSRRs of hydrophobicity and RP-HPLC retention of weakly acidic compounds.

    Science.gov (United States)

    Han, Shu-ying; Liang, Chao; Zou, Kuan; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

    2012-11-15

    The variation in mobile phase pH and ionizable solute dissociation constant (pK(a)) with the change of organic modifier fraction in hydroorganic mobile phase has seemingly been a troublesome problem in studies and applications of reversed phase high performance liquid chromatography (RP-HPLC). Most of the early studies regarding the RP-HPLC of acid-base compounds have to measure the actual pH of the mixed mobile phase rigorously, sometimes bringing difficulties in the practices of liquid chromatographic separation. In this paper, the effect of this variation on the apparent n-octanol/water partition coefficient (K(ow)″) and the related quantitative structure-retention relationship (QSRR) of logK(ow)″ vs. logk(w), the logarithm of retention factor of analytes in neat aqueous mobile phases, was investigated for weakly acidic compounds. This QSRR is commonly used as a classical method for K(ow) measurement by RP-HPLC. The theoretical and experimental derivation revealed that the variation in mobile phase pH and solute pK(a) will not affect the QSRRs of acidic compounds. This conclusion is proved to be suitable for various types of ion-suppressors, i.e., strong acid (perchloric acid), weak acid (acetic acid) and buffer salt (potassium dihydrogen phosphate/phosphoric acid, PBS). The QSRRs of logK(ow)″ vs. logk(w) were modeled by 11 substituted benzoic acids using different types of ion-suppressors in a binary methanol-water mobile phase to confirm our deduction. Although different types of ion-suppressor all can be used as mobile phase pH modifiers, the QSRR model obtained by using perchloric acid as the ion-suppressor was found to have the best result, and the slightly inferior QSRRs were obtained by using acetic acid or PBS as the ion-suppressor. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Misfit Layer Compounds and Ferecrystals: Model Systems for Thermoelectric Nanocomposites

    Directory of Open Access Journals (Sweden)

    Devin R. Merrill

    2015-04-01

    Full Text Available A basic summary of thermoelectric principles is presented in a historical context, following the evolution of the field from initial discovery to modern day high-zT materials. A specific focus is placed on nanocomposite materials as a means to solve the challenges presented by the contradictory material requirements necessary for efficient thermal energy harvest. Misfit layer compounds are highlighted as an example of a highly ordered anisotropic nanocomposite system. Their layered structure provides the opportunity to use multiple constituents for improved thermoelectric performance, through both enhanced phonon scattering at interfaces and through electronic interactions between the constituents. Recently, a class of metastable, turbostratically-disordered misfit layer compounds has been synthesized using a kinetically controlled approach with low reaction temperatures. The kinetically stabilized structures can be prepared with a variety of constituent ratios and layering schemes, providing an avenue to systematically understand structure-function relationships not possible in the thermodynamic compounds. We summarize the work that has been done to date on these materials. The observed turbostratic disorder has been shown to result in extremely low cross plane thermal conductivity and in plane thermal conductivities that are also very small, suggesting the structural motif could be attractive as thermoelectric materials if the power factor could be improved. The first 10 compounds in the [(PbSe1+δ]m(TiSe2n family (m, n ≤ 3 are reported as a case study. As n increases, the magnitude of the Seebeck coefficient is significantly increased without a simultaneous decrease in the in-plane electrical conductivity, resulting in an improved thermoelectric power factor.

  5. Energetics of hydrogen bonding in proteins: a model compound study.

    OpenAIRE

    Habermann, S. M.; Murphy, K. P.

    1996-01-01

    Differences in the energetics of amide-amide and amide-hydroxyl hydrogen bonds in proteins have been explored from the effect of hydroxyl groups on the structure and dissolution energetics of a series of crystalline cyclic dipeptides. The calorimetrically determined energetics are interpreted in light of the crystal structures of the studied compounds. Our results indicate that the amide-amide and amide-hydroxyl hydrogen bonds both provide considerable enthalpic stability, but that the amide-...

  6. Protective effect of Heliotropium foertherianum (Boraginaceae) folk remedy and its active compound, rosmarinic acid, against a Pacific ciguatoxin.

    Science.gov (United States)

    Rossi, Fanny; Jullian, Valérie; Pawlowiez, Ralph; Kumar-Roiné, Shilpa; Haddad, Mohamed; Darius, H Taiana; Gaertner-Mazouni, Nabila; Chinain, Mireille; Laurent, Dominique

    2012-08-30

    Senescent leaves of Heliotropium foertherianum Diane & Hilger (Boraginaceae) are traditionally used in the Pacific region to treat Ciguatera Fish Poisoning. This plant contains rosmarinic acid that is known for its multiple biological activities. In the present study, H. foertherianum aqueous extract, rosmarinic acid and its derivatives were evaluated for their capacity to reduce the effect of ciguatoxins. Aqueous extract of H. foertherianum leaves was prepared and studied for its effects against a Pacific ciguatoxin (P-CTX-1B) in the neuroblastoma cell assay and the receptor binding assay. Rosmarinic acid and six derivatives were also evaluated by means of these bioassays. For this purpose, we have developed an improved synthetic route for caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE). Both the aqueous extract of H. foertherianum leaves and rosmarinic acid showed inhibitory activities against a Pacific ciguatoxin in the above bioassays. Among all the molecules that were evaluated, rosmarinic acid was the most active compound. These results confirm further the potential of H. foertherianum in the treatment of Ciguatera Fish Poisoning. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. Investigating actinide compounds within a hybrid MCSCF-DFT model

    International Nuclear Information System (INIS)

    Fromager, E.; Jensen, H.J.A.; Wahlin, P.; Real, F.; Wahlgren, U.

    2007-01-01

    Complete text of publication follows: Investigations of actinide chemistry with quantum chemical methods still remain a complicated task since it requires an accurate and efficient treatment of the environment (crystal or solvent) as well as relativistic and electron correlation effects. Concerning the latter, the current correlated methods, based on either Density-Functional Theory (DFT) or Wave-Function Theory (WFT), have their advantages and drawbacks. On the one hand, Kohn-Sham DFT (KS-DFT) calculates the dynamic correlation quite accurately and at a fairly low computational cost. However, it does not treat adequately the static correlation, which is significant in some actinide compounds because of the near-degeneracy of the 5f orbitals: a first example is the bent geometry obtained in KS-DFT(B3LYP) for the neptunyl ion NpO 2 3+ , which is found to be linear within a Multi-Configurational Self-Consistent Field (MCSCF) model [1]. A second one is the stable and bent geometry obtained in KS-DFT(B3LYP) for the plutonyl ion PuO 2 4+ , which disintegrates at the MCSCF level [1]. On the other hand, WFT can describe the static correlation, using for example a MCSCF model, but then an important part of the dynamic correlation has to be neglected. This can be recovered with perturbation-theory based methods like for example CASPT2 or NEVPT2, but their computational complexity prevents large scale calculations. It is therefore of great interest to develop a hybrid MCSCF-DFT model which combines the best of both WFT and DFT approaches. The merge of WFT and DFT can be achieved by splitting the two-electron interaction into long-range and short-range parts [2]. The long-range part is then treated by WFT and the short-range part by DFT. We use the so-called 'erf' long-range interaction erf(μr 12 )/r 12 , which is based on the standard error function, and where μ is a free parameter which controls the long/short-range decomposition. The newly proposed recipe for the

  8. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta)

    International Nuclear Information System (INIS)

    Figueroa, Félix L.; Korbee, Nathalie; Abdala, Roberto; Jerez, Celia G.; López-de la Torre, Mayra; Güenaga, Leire; Larrubia, María A.; Gómez-Pinchetti, Juan L.

    2012-01-01

    The biofiltration capacity, biomass-yield and accumulation of N- and C-compounds of Hydropuntia cornea were analyzed. Algae were grown in different conditions for 28 d: outdoor and indoor, with or without fishpond effluents. N-uptake efficiency of these effluents was higher than 95% after 7 d both outdoors and indoors. N-enriched conditions reduced the extent of photoinhibition and increased the maximal quantum yield in H. cornea. The biomass-yield was higher in outdoor grown-algae after 7 d and decreased independently of the treatment after 28 d. N, acid polysaccharide (AP) and mycosporine-like amino acid (MAA)-yields decreased throughout the experiment in all conditions. The highest MAA-yield was observed in fishpond effluent outdoor-grown algae, indicating a positive effect of increased radiation on MAA accumulation. However, APs were higher under N-depleted conditions. The use of MAAs as UV-screening and antioxidants, and the use of AP as immunostimulants are discussed.

  9. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta).

    Science.gov (United States)

    Figueroa, Félix L; Korbee, Nathalie; Abdala, Roberto; Jerez, Celia G; López-de la Torre, Mayra; Güenaga, Leire; Larrubia, María A; Gómez-Pinchetti, Juan L

    2012-02-01

    The biofiltration capacity, biomass-yield and accumulation of N- and C-compounds of Hydropuntia cornea were analyzed. Algae were grown in different conditions for 28 d: outdoor and indoor, with or without fishpond effluents. N-uptake efficiency of these effluents was higher than 95% after 7 d both outdoors and indoors. N-enriched conditions reduced the extent of photoinhibition and increased the maximal quantum yield in H. cornea. The biomass-yield was higher in outdoor grown-algae after 7 d and decreased independently of the treatment after 28 d. N, acid polysaccharide (AP) and mycosporine-like amino acid (MAA)-yields decreased throughout the experiment in all conditions. The highest MAA-yield was observed in fishpond effluent outdoor-grown algae, indicating a positive effect of increased radiation on MAA accumulation. However, APs were higher under N-depleted conditions. The use of MAAs as UV-screening and antioxidants, and the use of AP as immunostimulants are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Structural and functional characterization of solute binding proteins for aromatic compounds derived from lignin: p-coumaric acid and related aromatic acids.

    Science.gov (United States)

    Tan, Kemin; Chang, Changsoo; Cuff, Marianne; Osipiuk, Jerzy; Landorf, Elizabeth; Mack, Jamey C; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R

    2013-10-01

    Lignin comprises 15-25% of plant biomass and represents a major environmental carbon source for utilization by soil microorganisms. Access to this energy resource requires the action of fungal and bacterial enzymes to break down the lignin polymer into a complex assortment of aromatic compounds that can be transported into the cells. To improve our understanding of the utilization of lignin by microorganisms, we characterized the molecular properties of solute binding proteins of ATP-binding cassette transporter proteins that interact with these compounds. A combination of functional screens and structural studies characterized the binding specificity of the solute binding proteins for aromatic compounds derived from lignin such as p-coumarate, 3-phenylpropionic acid and compounds with more complex ring substitutions. A ligand screen based on thermal stabilization identified several binding protein clusters that exhibit preferences based on the size or number of aromatic ring substituents. Multiple X-ray crystal structures of protein-ligand complexes for these clusters identified the molecular basis of the binding specificity for the lignin-derived aromatic compounds. The screens and structural data provide new functional assignments for these solute-binding proteins which can be used to infer their transport specificity. This knowledge of the functional roles and molecular binding specificity of these proteins will support the identification of the specific enzymes and regulatory proteins of peripheral pathways that funnel these compounds to central metabolic pathways and will improve the predictive power of sequence-based functional annotation methods for this family of proteins. Copyright © 2013 Wiley Periodicals, Inc.

  11. Infrared and Raman spectra of uric acid and its 15N and D labelled compounds

    International Nuclear Information System (INIS)

    Majoube, Michel

    Infrared and Raman spectra of polycrystalline uric acid (2, 6, 8-trioxypurine) 1.3, 7 and 9- 15 N and deuterated analogues have been determined. Band shifts with 15 N substitution and with deuteration are discussed. An assignment of fundamental vibrations of uric acid is proposed from the comparison of the eight isotopically substituted analogues [fr

  12. Discovery of a novel activator of 5-lipoxygenase from an anacardic acid derived compound collection

    NARCIS (Netherlands)

    Wisastra, Rosalina; Kok, Petra A. M.; Eleftheriadis, Nikolaos; Baumgartner, Matthew P.; Camacho, Carlos J.; Haisma, Hidde J.; Dekker, Frank J.

    2013-01-01

    Lipoxygenases (LOXs) and cyclooxygenases (COXs) metabolize poly-unsaturated fatty acids into inflammatory signaling molecules. Modulation of the activity of these enzymes may provide new approaches for therapy of inflammatory diseases. In this study, we screened novel anacardic acid derivatives as

  13. Synthesis of 6-phosphofructose aspartic acid and some related Amadori compounds.

    Science.gov (United States)

    Hansen, Alexandar L; Behrman, Edward J

    2016-08-05

    We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Sorbic acid interaction with sulfur dioxide in model food systems

    Energy Technology Data Exchange (ETDEWEB)

    Namor, O G

    1987-01-01

    The first chapter deals with the chemistry of sorbic acid and sulfur dioxide. The second chapter describes a study of the degradation products of sorbic acid, in aqueous systems, in the presence of sulfur dioxide and a possible mechanism for the occurrence of these products is proposed. Chapter three deals with the preparation and degradation of 6-(/sup 13/C)sorbic acid in order to find evidence for, or against, the mechanism proposed in chapter two. It also gives details of syntheses attempted in order to obtain 6- (/sup 13/C)sorbic acid. The interaction of sorbic acid and sulfur dioxide in real food systems is the subject of the fourth chapter. The food systems studied were mayonnaise, tomato puree, orange juice and cottage cheese. The effect of packaging on the rate of degradation of sorbic acid was also investigated. The final chapter deals with a microbiological study of two homologues of sorbic acid, 2,4-heptadienoic acid, 2,4-octadienoic acid. The fungicidal activity of these two compounds, towards selected fungi, was analyzed. 4-Oxobut-2-enoic acid, a degradation product of sorbic acid in aqueous systems, was also analyzed as a possible fungistat.

  15. Amino acids and volatile compounds in wines from Cabernet Sauvignon and Tempranillo varieties subjected to malolactic fermentation in barrels.

    Science.gov (United States)

    Hernández-Orte, P; Peña, A; Pardo, I; Cacho, J; Ferreira, V

    2012-04-01

    The aim of the present paper is to compare the behaviour of industrial lactic bacteria and indigenous bacteria of the cellar when malolactic fermentation was carried out in barrels. The effects of these bacteria on the concentration of metabolised amino acids during malolactic fermentation and on the composition of volatile compounds both before and after malolactic fermentation are studied. The experiment was performed with wines of the Tempranillo and Cabernet Sauvignon varieties. An analysis has been made of the easily extractable volatile compounds of the wood and the compounds from the grapes, and the action of the yeasts during the alcoholic fermentation. Acetoin and diacetyl decreased during the malolactic fermentation in barrels and the concentrations of furfural and its derivatives were up to 100 times higher in wines not subjected to malolactic fermentation. Most of the volatile phenols increased during the malolactic fermentation in wines of the Tempranillo variety, while only guaiacol (p < 0.05) and t-isoeugenol increased in the Cabernet Sauvignon wines. The decrease in amino acids during the malolactic fermentation depends much more on the variety than on the bacterial strain which carries out the malolactic fermentation.

  16. Modeling of a dissolution system for transuranic compounds

    International Nuclear Information System (INIS)

    Chiba, Z.; Dease, C.

    1991-02-01

    A system is currently being developed at Lawrence Livermore Laboratory to treat transuranic wastes by means of a mediated electrochemical oxidation process. The process involves generating Ag( ++ ) from a solution of silver nitrate and nitric acid in an electrochemical cell. Ag( ++ ) is highly reactive and is capable of attacking many organic and inorganic substances. In particular, if a mixture of particles containing transuranic and other scrap metal oxides is allowed to react with Ag( ++ ) in a nitric acid solution, the transuranic oxides will dissolve and can be removed with the solution leaving the other insoluble oxides behind. The dissolution of the transuranic oxides by reactions with Ag( ++ ) occurs due to further oxidation to higher valence states and the formation of soluble ions such as MO 2 + and MO 2 ++ . 7 refs., 5 figs., 1 tab

  17. Selecting a Response in Task Switching: Testing a Model of Compound Cue Retrieval

    Science.gov (United States)

    Schneider, Darryl W.; Logan, Gordon D.

    2009-01-01

    How can a task-appropriate response be selected for an ambiguous target stimulus in task-switching situations? One answer is to use compound cue retrieval, whereby stimuli serve as joint retrieval cues to select a response from long-term memory. In the present study, the authors tested how well a model of compound cue retrieval could account for a…

  18. Development of corresponding states model for estimation of the surface tension of chemical compounds

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Eslamimanesh, Ali; Sattari, Mehdi

    2013-01-01

    include critical temperature or temperature/critical volume/acentric factor/critical pressure/reduced temperature/reduced normal boiling point temperature/molecular weight of the compounds. Around 1,300 surface tension data of 118 random compounds are used for developing the first model (a four...

  19. Sensory Description of Cultivars (Coffea Arabica L. Resistant to Rust and Its Correlation with Caffeine, Trigonelline, and Chlorogenic Acid Compounds

    Directory of Open Access Journals (Sweden)

    Larissa de Oliveira Fassio

    2016-01-01

    Full Text Available Considering the importance of the chemical compounds in Arabica coffee beans in the definition of the drink sensory quality and authentication of coffee regions, the aim of this study was to evaluate, from principal component analysis—PCA—if there is a relation between the caffeine, trigonelline, and chlorogenic acid (5-CQA content and the sensory attributes of the drink, and in this context, enabling the differentiation of cultivars in two coffee-producing regions of Brazil. We evaluated seven rust-resistant Coffea arabica cultivars, and two rust-susceptible cultivars in two cultivation environments: Lavras, in the southern region of Minas Gerais state, and Patrocinio in the Cerrado region of Minas Gerais. The flavor and acidity were determinant for differentiation of the cultivars and their interaction with the evaluated environments. Cultivars Araponga MG1, Catigua MG2, and Catigua MG1 are the most suitable for the production of specialty coffee in the state of Minas Gerais. A poor correlation was found between caffeine, trigonelline, 5-CQA contents, and fragrance, flavor, acidity, body, and final score attributes. However, these compounds enabled the differentiation of the environments. The PCA indicated superiority in the sensory quality of cultivars resistant to rust, compared to the control, Bourbon Amarelo, and Topázio MG1190.

  20. Synthesis of nanoscale layers of heteropoly compounds based on molybdophosphoric acid by ion lamination on the silica surface

    International Nuclear Information System (INIS)

    Gulina, L.B.; Tolstoj, V.P.

    2004-01-01

    Nanolayers of iso- and heteropolycompound of the composition Zr 2.6 (OH) x PMo 8.0 Sn 1.9 O y · nH 2 O were synthesized by the method of ion lamination during successive treatment of quartz substrate by water solutions of reduced molybdophosphoric acid and zirconium acetate. The compounds prepared were characterized by the methods of electronic, IR and X-ray photoelectron spectroscopy. It was shown that heating of the compounds in the air at 200-400 deg C involves removal of water molecules from the layer, Mo 5+ oxidation to Mo 6+ and formation of chemical bonds Mo-O-Zr and Mo-O-Sn [ru

  1. Crystal structure of caesium hydrogen (L)-aspartate and an overview of crystalline compounds of aspartic acid with inorganic constituents

    Energy Technology Data Exchange (ETDEWEB)

    Fleck, M. [Universitaet Wien (Austria). Institut fuer Mineralogie und Kristallographie; Emmerich, R.; Bohaty, L. [Universitaet zu Koeln (Austria). Institut fuer Kristallographie

    2010-08-15

    The crystal structure of the new polar compound caesium hydrogen (L)-aspartate, Cs(C{sub 4}H{sub 6}NO{sub 4}), (abbreviated: Cs(L -AspH)) was determined from single crystal X-ray diffraction data; it comprises two crystallographically different L -AspH anions that are connected via caesium cations to form a three dimensional framework. The Cs ions are irregularly sevenfold[Cs1O{sub 7}] respectively eightfold[Cs2O{sub 8}] coordinated to all {alpha}- and {beta}- carboxylate oxygen atoms. Cs(L -AspH) represents a novel structure type of its own, as do most compounds of (L)-aspartic acid with inorganic constituents. A brief summary of such structurally known aspartates is given. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Proton-transfer compounds of 8-hydroxy-7-iodoquinoline-5-sulfonic acid (ferron) with 4-chloroaniline and 4-bromoaniline.

    Science.gov (United States)

    Smith, Graham; Wermuth, Urs D; Healy, Peter C

    2007-07-01

    The crystal structures of the proton-transfer compounds of ferron (8-hydroxy-7-iodoquinoline-5-sulfonic acid) with 4-chloroaniline and 4-bromoaniline, namely 4-chloroanilinium 8-hydroxy-7-iodoquinoline-5-sulfonate monohydrate, C(6)H(7)ClN(+) x C(9)H(5)INO(4)S(-) x H(2)O, and 4-bromoanilinium 8-hydroxy-7-iodoquinoline-5-sulfonate monohydrate, C(6)H(7)BrN(+) x C(9)H(5)INO(4)S(-) x H(2)O, have been determined. The compounds are isomorphous and comprise sheets of hydrogen-bonded cations, anions and water molecules which are extended into a three-dimensional framework structure through centrosymmetric R(2)(2)(10) O-H...N hydrogen-bonded ferron dimer interactions.

  3. Quark compound bag (QCB) model and nucleon-nucleon interaction

    International Nuclear Information System (INIS)

    Simonov, Yu.A.

    1983-01-01

    Quark degrees of freedom are treated in the NN system in the framework of the QCB model. The resulting QCB potential is in agreement with experimental data. P-matrix analysis inherent to the QCB model is discussed in detail. Applications of the QCB model are given including the weak NN interaction

  4. Omega-3 fatty acids, phenolic compounds and antioxidant characteristics of chia oil supplemented margarine.

    Science.gov (United States)

    Nadeem, Muhammad; Imran, Muhammad; Taj, Imran; Ajmal, Muhammad; Junaid, Muhammad

    2017-05-31

    Chia (Salvia hispanica L.) is known as power house of omega fatty acids which has great health benefits. It contains up to 78% linolenic acid (ω-3) and 18% linoleic acid (ω-6), which could be a great source of omega-3 fatty acids for functional foods. Therefore, in this study, margarines were prepared with supplementation of different concentrations of chia oil to enhance omega-3 fatty acids, antioxidant characteristics and oxidative stability of the product. Margarines were formulated from non-hydrogenated palm oil, palm kernel and butter. Margarines were supplemented with 5, 10, 15 and 20% chia oil (T 1 , T 2 , T 3 and T 4 ), respectively. Margarine without any addition of chia oil was kept as control. Margarine samples were stored at 5 °C for a period of 90 days. Physico-chemical (fat, moisture, refractive index, melting point, solid fat index, fatty acids profile, total phenolic contents, DPPH free radical scavenging activity, free fatty acids and peroxide value) and sensory characteristics were studied at the interval of 45 days. The melting point of T 1 , T 2 , T 3 and T 4 developed in current investigation were 34.2, 33.8, 33.1 and 32.5 °C, respectively. The solid fat index of control, T 1 , T 2 , T 3 and T 4 were 47.21, 22.71, 20.33, 18.12 and 16.58%, respectively. The α-linolenic acid contents in T 1 , T 2 , T 3 and T 4 were found 2.92, 5.85, 9.22, 12.29%, respectively. The concentration of eicosanoic acid in T 2 , T 3 and T 4 was 1.82, 3.52, 6.43 and 9.81%, respectively. The content of docosahexanoic acid in T 2 , T 3 and T 4 was present 1.26, 2.64, 3.49 and 5.19%, respectively. The omega-3 fatty acids were not detected in the control sample. Total phenolic contents of control, T 1 , T 2 , T 3 and T 4 samples were 0.27, 2.22, 4.15, 7.23 and 11.42 mg GAE/mL, respectively. DPPH free radical scavenging activity for control, T 1 , T 2 , T 3 and T 4 was noted 65.8, 5.37, 17.82, 24.95, 45.42 and 62.8%, respectively. Chlorogenic acid, caffeic acid

  5. Use of 3-(4-hydroxyphenyl)propionic acid as electron donating compound in a potentiometric aflatoxin M1-immunosensor

    International Nuclear Information System (INIS)

    Rameil, Steffen; Schubert, Peter; Grundmann, Peter; Dietrich, Richard; Maertlbauer, Erwin

    2010-01-01

    We developed a potentiometric aflatoxin M 1 -immunosensor which utilizes 3-(4-hydroxyphenyl)propionic acid (p-HPPA) as electron donating compound for horseradish peroxidase (HRP; EC 1.11.1.7). The assay system consists of a polypyrrole-surface-working electrode coated with a polyclonal anti-M 1 antibody (pAb-AFM 1 ), a Ag/AgCl reference electrode and a HRP-aflatoxin B 1 conjugate (HRP-AFB 1 conjugate). To optimize the potentiometric measuring system p-HPPA as well as related compounds serving as electron donating compounds were compared. Also the influence of different buffer systems, varying pH and substrate concentrations on signal intensity was investigated. Our results suggest that reaction conditions that favor the formation of Pummerer's type ketones lead to an increase in signal intensity rather than formation of fluorescent dye. Comparison with commercial ready-to-use HRP electron donating compounds such as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), o-phenylenediamine (OPD) or 3,3',5,5'-tetramethylbenzidine (TMB) showed that only 34%, 77% and 49% of the signal intensity of p-HPPA were reached, respectively. The optimized assay had a detection limit of 40 pg mL -1 and allowed detection of 500 pg mL -1 (FDA action limit) aflatoxin M 1 (AFM 1 ) in pasteurized milk and UHT-milk containing 0.3-3.8% fat within 10 min without any sample treatment. The working range was between 250 and 2000 pg mL -1 AFM 1 .

  6. Uncatalysed and potassium-catalysed pyrolysis of the cell-wall constituents of biomass and their model compounds

    Energy Technology Data Exchange (ETDEWEB)

    Nowakowski, Daniel J.; Jones, Jenny M. [Energy and Resources Research Institute, School of Process, Environmental and Materials Engineering (SPEME), University of Leeds, Leeds, LS2 9JT (United Kingdom)

    2008-09-15

    Cell-wall components (cellulose, hemicellulose (oat spelt xylan), lignin (Organosolv)), and model compounds (levoglucosan (an intermediate product of cellulose decomposition) and chlorogenic acid (structurally similar to lignin polymer units)) have been investigated to probe in detail the influence of potassium on their pyrolysis behaviours as well as their uncatalysed decomposition reaction. Cellulose and lignin were pretreated to remove salts and metals by hydrochloric acid, and this dematerialized sample was impregnated with 1% of potassium as potassium acetate. Levoglucosan, xylan and chlorogenic acid were mixed with CH{sub 3}COOK to introduce 1% K. Characterisation was performed using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). In addition to the TGA pyrolysis, pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) analysis was introduced to examine reaction products. Potassium-catalysed pyrolysis has a huge influence on the char formation stage and increases the char yields considerably (from 7.7% for raw cellulose to 27.7% for potassium impregnated cellulose; from 5.7% for raw levoglucosan to 20.8% for levoglucosan with CH{sub 3}COOK added). Major changes in the pyrolytic decomposition pathways were observed for cellulose, levoglucosan and chlorogenic acid. The results for cellulose and levoglucosan are consistent with a base catalysed route in the presence of the potassium salt which promotes complete decomposition of glucosidic units by a heterolytic mechanism and favours its direct depolymerization and fragmentation to low molecular weight components (e.g. acetic acid, formic acid, glyoxal, hydroxyacetaldehyde and acetol). Base catalysed polymerization reactions increase the char yield. Potassium-catalysed lignin pyrolysis is very significant: the temperature of maximum conversion in pyrolysis shifts to lower temperature by 70 K and catalysed polymerization reactions increase the char yield from 37% to 51%. A similar trend

  7. Determination of aminoglycoside antibiotics using complex compounds of chromotropic acid bisazoderivatives with rare earth ions

    International Nuclear Information System (INIS)

    Alykov, N.M.

    1981-01-01

    Studies of complex formation of bisazo derivatives of chromotropic acid with rare earth ions and aminoglycoside antibiotics have made it possible to choose carboxyarsenazo, orthanyl R and carboxynitrazo as highly sensitive reagents for determining aminoglycoside antibiotics. Conditions have been found for the formation of precipitates of different-ligand complexes containing rare earth ions, bisazo derivatives of chromotropic acid and aminogylcoside antibiotics. A procedure has been worked out of determining the antibiotics in biological samples with carboxyarsenazo [ru

  8. Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

    OpenAIRE

    Arumugham Suresh; Ramasamy Praveenkumar; Ramasamy Thangaraj; Felix Lewis Oscar; Edachery Baldev; Dharumadurai Dhanasekaran; Nooruddin Thajuddin

    2014-01-01

    Objective: To evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME) extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. Methods: Antimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp.,...

  9. Fulvic acid-like organic compounds control nucleation of marine calcite under suboxic conditions

    NARCIS (Netherlands)

    Neuweiler, F.; D'Orazio, M.; Immenhauser, A.M.; Geipel, G.; Heise, K.H.; Cocozza, C.; Miano, T.M.

    2003-01-01

    Intracrystalline organic compounds, enclosed within in situprecipitated marine microcrystalline calcite (automicrite), might represent either an inclusion or the catalyst of such precipitation. We use evidence from a Lower Cretaceous deep-water carbonate mound to show (1) the original source, (2)

  10. Enhanced fatty acid production in engineered chemolithoautotrophic bacteria using reduced sulfur compounds as energy sources

    DEFF Research Database (Denmark)

    Beller, Harry R.; Zhou, Peng; Jewell, Talia N.M.

    2016-01-01

    Chemolithoautotrophic bacteria that oxidize reduced sulfur compounds, such as H2S, while fixing CO2 are an untapped source of renewable bioproducts from sulfide-laden waste, such as municipal wastewater. In this study, we report engineering of the chemolithoautotrophic bacterium Thiobacillus...

  11. Identification of gut-derived metabolites of maslinic acid, a bioactive compound from Olea europaea L.

    Science.gov (United States)

    Lozano-Mena, Glòria; Sánchez-González, Marta; Parra, Andrés; Juan, M Emília; Planas, Joana M

    2016-09-01

    Maslinic acid has been described to exert a chemopreventive activity in colon cancer. Hereby, we determined maslinic acid and its metabolites in the rat intestine previous oral administration as a first step in elucidating whether this triterpene might be used as a nutraceutical. Maslinic acid was orally administered at 1, 2, and 5 mg/kg to male Sprague-Dawley for 2 days. At 24 h after the last administration, the content of the duodenum and jejunum, ileum, cecum, and colon was collected and extracted with methanol 80% prior to LC-APCI-MS analysis. The developed method was validated providing suitable sensitivity (LOQ of 5 nM), good recovery (97.8 ± 3.6%), linear correlation, and appropriate precision (< 9%). Maslinic acid was detected in all the segments with higher concentrations in the distal part of the intestine. LC-APCI-LTQ-ORBITRAP-MS allowed the identification of 11 gut-derived metabolites that were formed by mono-, dihydroxylation, and dehydrogenation reactions. Maslinic acid undergoes phase I reactions resulting in a majority of monohydroxylated metabolites without the presence of phase II derivatives. The high concentration of maslinic acid achieved in the intestine suggests that it could exert a beneficial effect in the prevention of colon cancer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Spectrographic determination of lanthanides in high-purity uranium compounds, after chromatographic separation by alumina-hydrofluoric acid

    International Nuclear Information System (INIS)

    Lordello, A.R.; Abrao, A.

    1979-01-01

    A method is presented for the determination of fourteen rare earth elements in high-purity uranium compounds by emission spectrography. The rare earths are chromatographically separated from uranium by using alumina-hydrofluoric acid. Lanthanum is used both as collector and internal standard. The technique of excitation involves a total consumption of the sample in a 17 ampere direct current arc. The range of determination is about 0.005 to 0.5 μg/g uranium. The coefficient of variation for Pr, Ho, Dy, Er, Tm, Lu, Gd and Tb amounts to 10%. (Author) [pt

  13. On complex compounds of molybdenum(5) with nicotinic amide, isonicotinic acid hydrazide and some of its derivatives

    International Nuclear Information System (INIS)

    Azizov, M.M.; Kushakbaev, A.; Parpiev, N.A.

    1977-01-01

    Oxychloride complexes of molybdenum (5) with polyfunctional ligands (L), namely with nicotinamide (NA), isonicotinic acid hydrazide (INH) and its derivatives (ftivazide, saluzide and larusan) have been synthesized and investigated. In ethanol all the ligands independently of their molar ratio form with MoCl 5 a non-electrolite compound MoOCl 3 xL 2 . Infrared spectra of the complexes suggest that in Mo(5) complexeS with NA and INH the central atom is bound through the pyridine nitrogen, whereas in the complexes with INH derivatives it is bound throught the carbonyl group oxygen

  14. Molecular distribution, seasonal variation, chemical transformation and sources of dicarboxylic acids and related compounds in atmospheric aerosols at remote marine Gosan site, Jeju Island

    Science.gov (United States)

    Kundu, S.; Kawamura, K.; Lee, M.

    2009-12-01

    between Chinese cities and Chichi-jima Island in Japan was observed higher than those in Chinese cities and lower than that of the Chichi-jima Island, pointing to the formation of diacid during long range transport. The lowest values of adipic/azelaic (C6/C9) and phthalic/azelaic (Ph/C9) were observed as a result of the overwhelming biogenic emission of the precursors (e.g., unsaturated fatty acids) of azelaic acid in summer.In this study, we will also discuss the sources and transport pathways of diacids and related compounds resolved using a hybrid receptor model, potential source contribution function (PSCF) and model results will be compared with available in-situ observations in East Asia.

  15. Effect of e-beam irradiation and microwave heating on the fatty acid composition and volatile compound profile of grass carp surimi

    International Nuclear Information System (INIS)

    Zhang, Hongfei; Wang, Wei; Wang, Haiyan; Ye, Qingfu

    2017-01-01

    In this study, we evaluated the effects of e-beam irradiationпј€1–7 kGyпј‰ and irradiation coupled to microwave heating (e-I-MC, 70 °C internal temperature) on the fatty acid composition and volatile compound profile of grass carp surimi. Compared to control samples, e-beam irradiation generated three novel volatile compounds (heptane, 2,6-dimethyl-nonane, and dimethyl disulfide) and increased the relative proportions of alcohols, aldehydes, and ketones. Meanwhile, e-I-MC significantly increased aldehyde levels and generated five heterocyclic compounds along with these three novel compounds. No significant difference in volatile compounds were detected in e-I-MC samples with increasing irradiation dose (p>0.05), comparing to the control group. E-beam irradiation at 5 and 7 kGy increased the levels of saturated fatty acids (SFAs) and decreased the levels of unsaturated fatty acids (p≤0.05), but did not affect the content of trans fatty acid levels (p>0.05). Irradiation, which had no significant effects on (Eicosapentaenoic acid) EPA, decreased (Docose Hexaenoie Acid) DHA levels. In the e-I-MC group, SFA levels increased and PUFA levels decreased. Additionally, MUFA levels were unaffected and trans fatty acid levels increased slightly following e-I-MC. - Highlights: • E-beam irradiation generated three novel volatile compounds. • E-beam irradiation increased the relative proportions of alcohols, aldehydes, and ketones. • E-beam irradiation coupled to microwave heating increased aldehyde levels and generated five heterocyclic compounds. • E-beam irradiation at 5 and 7 kGy decreased the levels of unsaturated fatty acids, but did not affect trans fatty acid levels.

  16. Fluxes of biogenic volatile organic compounds measured and modelled above a Norway spruce forest

    Science.gov (United States)

    Juráň, Stanislav; Fares, Silvano; Pallozzi, Emanuele; Guidolotti, Gabriele; Savi, Flavia; Alivernini, Alessandro; Calfapietra, Carlo; Večeřová, Kristýna; Křůmal, Kamil; Večeřa, Zbyněk; Cudlín, Pavel; Urban, Otmar

    2016-04-01

    Fluxes of biogenic volatile organic compounds (BVOCs) were investigated at Norway spruce forest at Bílý Kříž in Beskydy Mountains of the Czech Republic during the summer 2014. A proton-transfer-reaction-time-of-flight mass spectrometer (PTR-TOF-MS, Ionicon Analytik, Austria) has been coupled with eddy-covariance system. Additionally, Inverse Lagrangian Transport Model has been used to derive fluxes from concentration gradient of various monoterpenes previously absorbed into n-heptane by wet effluent diffusion denuder with consequent quantification by gas chromatography with mass spectrometry detection. Modelled data cover each one day of three years with different climatic conditions and previous precipitation patterns. Model MEGAN was run to cover all dataset with monoterpene fluxes and measured basal emission factor. Highest fluxes measured by eddy-covariance were recorded during the noon hours, represented particularly by monoterpenes and isoprene. Inverse Lagrangian Transport Model suggests most abundant monoterpene fluxes being α- and β-pinene. Principal component analysis revealed dependencies of individual monoterpene fluxes on air temperature and particularly global radiation; however, these dependencies were monoterpene specific. Relationships of monoterpene fluxes with CO2 flux and relative air humidity were found to be negative. MEGAN model correlated to eddy-covariance PTR-TOF-MS measurement evince particular differences, which will be shown and discussed. Bi-directional fluxes of oxygenated short-chain volatiles (methanol, formaldehyde, acetone, acetaldehyde, formic acid, acetic acid, methyl vinyl ketone, methacrolein, and methyl ethyl ketone) were recorded by PTR-TOF-MS. Volatiles of anthropogenic origin as benzene and toluene were likely transported from the most benzene polluted region in Europe - Ostrava city and adjacent part of Poland around Katowice, where metallurgical and coal mining industries are located. Those were accumulated during

  17. Functionalized antibiofilm thin coatings based on PLA–PVA microspheres loaded with usnic acid natural compounds fabricated by MAPLE

    Energy Technology Data Exchange (ETDEWEB)

    Grumezescu, Valentina [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, PO Box MG-36, Bucharest-Magurele, Bucharest (Romania); University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Science and Engineering of Oxidic Materials and Nanomaterials, Polizu Street no 1-7, 011061 Bucharest (Romania); Socol, Gabriel [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, PO Box MG-36, Bucharest-Magurele, Bucharest (Romania); Grumezescu, Alexandru Mihai, E-mail: grumezescu@yahoo.com [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Science and Engineering of Oxidic Materials and Nanomaterials, Polizu Street no 1-7, 011061 Bucharest (Romania); Holban, Alina Maria [Faculty of Biology, University of Bucharest, Microbiology Immunology Department, Aleea Portocalelor 1-3, Sector 5, 77206 Bucharest (Romania); Ficai, Anton [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Science and Engineering of Oxidic Materials and Nanomaterials, Polizu Street no 1-7, 011061 Bucharest (Romania); Truşcǎ, Roxana [S.C. Metav-CD S.A., 31Rosetti Str., 020015 Bucharest (Romania); Bleotu, Coralia [Stefan S Nicolau Institute of Virology, Bucharest (Romania); Balaure, Paul Cǎtǎlin [Department of Organic Chemistry, Faculty of Applied Chemistry and Materials Science, Politehnica Universitiy of Bucharest, Polizu Street no 1-7, 011061 Bucharest (Romania); Cristescu, Rodica [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, PO Box MG-36, Bucharest-Magurele, Bucharest (Romania); Chifiriuc, Mariana Carmen [Faculty of Biology, University of Bucharest, Microbiology Immunology Department, Aleea Portocalelor 1-3, Sector 5, 77206 Bucharest (Romania)

    2014-05-01

    We report the fabrication of thin coatings of PLA–PVA microspheres loaded with usnic acid by matrix assisted pulsed laser evaporation (MAPLE) onto Ti substrate. The obtained coatings have been physico-chemically characterized by scanning electron microscopy (SEM) and infrared microscopy (IRM). In vitro biological assays have been performed in order to evaluate the influence of fabricated microsphere thin coatings on the Staphylococcus aureus biofilm development as well as their biocompatibility. SEM micrographs have revealed a uniform morphology of thin coatings, while IRM investigations have proved both the homogeneity and functional groups integrity of prepared thin coatings. The obtained microsphere-based thin coatings have proved to be efficient vehicles for usnic acid natural compound with antibiofilm activity, as demonstrated by the inhibitory activity on S. aureus mature biofilm development, opening new perspectives for the prevention and therapy associated to biofilm related infections.

  18. A Signal Detection Model of Compound Decision Tasks

    Science.gov (United States)

    2006-12-01

    strict isolation (for many examples of such models see Egan, 1975; Macmillan & Creelman , 1991). The result has been twofold: A rich corpus of decision...Macmillan & Creelman , 1991). It is important to point out that SDT models are primarily decision models. They specify the rules and procedures for how...Broadbent, 1958; Macmillan & Creelman , 1991; Nolte & Jaarsma, 1967; Swensson & Judy, 1981; Tanner & Norman, 1954). To better understand how these two

  19. Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Arumugham Suresh

    2014-09-01

    Full Text Available Objective: To evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. Methods: Antimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp., Candida sp., and Aspergillus niger and Aspergillus flavus. The FAME profiles were determined through gas chromatography with a flame ionization detector. Results: The FAME was found to be radial effective in inhibiting the radial growth of both bacterial and fungal pathogens. The FAME extracts exhibited the antibacterial activity against three clinical pathogens, namely, Escherichia coli, Salmonella typhi and Enterobacter sp. with the maximum zone of inhibition of 12.0 mm, 12.0 mm and 11.0 mm, respectively. The FAME showed moderate antifungal activity against Cryptococcus sp. (11.8 mm, Aspergillus niger (10.5 mm, Candida sp. (11.8 mm and Fusarium sp. (10.4 mm. Gas chromatography-flame ionization detector analysis revealed about 30 different FAMEs. Conclusions: We assume that the observed antimicrobial potency may be due to the abundance of erucic acid methyl ester (C22:0, arachidic acid methyl ester (C20:0, palmitic acid methyl ester (C16:0, cis-11-eicosenoicmethyl ester (C20:1, cis-11, 14-eicosadienoic acid methyl ester (C20:2 and linolenic acid methyl ester (C18:3 in FAMEs which appears to be promising to treat microbial diseases.

  20. A Temperature-Dependent Hysteresis Model for Relaxor Ferroelectric Compounds

    National Research Council Canada - National Science Library

    Raye, Julie K; Smith, Ralph C

    2004-01-01

    This paper summarizes the development of a homogenized free energy model which characterizes the temperature-dependent hysteresis and constitutive nonlinearities inherent to relaxor ferroelectric materials...

  1. Identifying developmental vascular disruptor compounds using a predictive signature and alternative toxicity models

    Science.gov (United States)

    Identifying Developmental Vascular Disruptor Compounds Using a Predictive Signature and Alternative Toxicity Models Presenting Author: Tamara Tal Affiliation: U.S. EPA/ORD/ISTD, RTP, NC, USA Chemically induced vascular toxicity during embryonic development can result in a wide...

  2. Effect of γ-irradiation on bioactivity, fatty acid compositions and volatile compounds of clary sage seed (Salvia sclarea L.).

    Science.gov (United States)

    Yalcin, Hasan; Ozturk, Ismet; Tulukcu, Eray; Sagdic, Osman

    2011-09-01

    Clary sage seeds (Salvia sclarea L.) were obtained from plants cultivated, and 2.5, 4.0, 5.5, and 7.0 kGy doses of γ-irradiation were applied to the clary sage seeds. They were then analyzed for their protein, ash, oil and dry matter contents, and fatty acid composition. Additionally, the total phenolic contents, antiradical, antioxidant activities, and volatile compounds of the clary sage seed extract were determined. There was no significant difference in protein content. However, the moisture, oil, and ash contents of the samples were affected by irradiation. While the 7 kGy dose had a positive effect on the total phenolic content and antiradical activity of the sage seed extract, all doses have negative effects on the antioxidant activity of the sage seed. The main fatty acid of the sage seed was remarkably found as α-linolenic acid. The four irradiation levels caused significant differences in fatty acid composition by affecting all fatty acids except palmitic, palmitoleic, and eicosenoic acids. The dominant volatile compounds of control sage seed were found as β-pinene (18.81%) and limonene (15.60%). Higher doses of the irradiation decreased volatile components of sage seed. Clary sage seed including high omega-3 can be irradiated with low doses (≤ 2.5 kGy) of γ-irradiation. Clary sage is one of the most popular Salvia species in Turkey and many countries. Clary sage seed has approximately 29% oil content and this oil contains >50% of α-linolenic acid. γ-Irradiation is widely applied in the preservation of spice quality. The present study shows that the antioxidant activity of the clary sage seed is decreased by γ-irradiation. Additionally, higher doses of irradiation also decreased the volatile components of sage seed. Therefore, we suggest that clary sage seed which includes high levels of omega-3 should be irradiated with low doses (≤ 2.5 kGy) of γ-irradiation. © 2011 Institute of Food Technologists®

  3. New 3,4-diaminobenzoic acid Schiff base compounds and their complexes: synthesis, characterization and thermodynamics.

    Science.gov (United States)

    Mohammadi, Khosro; Niad, Mahmood; Jafari, Tahereh

    2014-03-25

    Some new tetradentate Schiff base ligands (H3L) were prepared via condensation of 3,4-diaminobenzoic acid with 2-hydroxybenzaldehyde derivatives, such as 3,4-bis((E)-2,4-dihydroxybenzylideneamino)benzoic acid (H3L(1)), 3,4-bis((E)-2-hydroxy-3-methoxybenzylideneamino)benzoic acid (H3L(2)) and 3,4-bis((E)-5-bromo-2-hydroxybenzylideneamino)benzoic acid (H3L(4)). Additionally, a tetradentate Schiff base ligand 3,4-bis((E)-2-hydroxybenzylideneamino)benzoic acid (H3L(3)) and its complexes were synthesized. Their metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) were prepared in good yields from the reaction of the ligands with the corresponding metal acetate. They were characterized based on IR, (1)H NMR, Mass spectroscopy and UV-Vis spectroscopy. Also, the formation constants of the complexes were measured by UV-Vis spectroscopic titration at constant ionic strength 0.1M (NaClO4), at 25 °C in dimethylformamide (DMF) as a solvent. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  4. Consideration of the Verleur model of far-infrared spectroscopy of ternary compounds

    International Nuclear Information System (INIS)

    Robouch, B. V.; Kisiel, A.; Sheregii, E. M.

    2001-01-01

    The clustering model proposed by Verleur and Barker [Phys. Rev. 149, 715 (1966)] to interpret far infrared data for face-centered-cubic ternary compounds is critically analyzed. It is shown that their approach, satisfactory for fitting some ternary compound spectral curves, is too restricted by its one-parameter β model to be able to describe preferences (with respect to a random distribution case) for the five tetrahedron configurations

  5. Dynamics in the concentrations of health-promoting compounds: lupeol, mangiferin and different phenolic acids during postharvest ripening of mango fruit.

    Science.gov (United States)

    Vithana, Mekhala Dk; Singh, Zora; Johnson, Stuart K

    2018-03-01

    Mango fruit (Mangifera indica L.) is renowned for its pleasant taste and as a rich source of health beneficial compounds. The aim of this study was to investigate the changes in concentrations of health-promoting compounds, namely ascorbic acid, carotenoids, antioxidants, lupeol, mangiferin, total phenols and individual phenolic acids, as well as ethylene production and respiration rates during climacteric ripening in 'Kensington Pride' and 'R2E2' mango fruit. The climacteric ethylene and respiration peaks were noted on the third day of the fruit ripening period. The concentrations of total carotenoids in the pulp, total antioxidants in both pulp and peel, and total phenols of the peel, lupeol and mangiferin were significantly elevated, whereas the concentration of ascorbic acid declined during post-climacteric ripening. Gallic, chlorogenic and vanillic acids were identified as the major phenolic acids in both pulp and peel of 'Kensington Pride' and 'R2E2' mangoes. The concentrations of phenolic acids (gallic, chlorogenic, vanillic, ferulic and caffeic acids) also increased during the post-climacteric phase. The concentrations of all phenolic compounds were several-fold higher in the peel than pulp. Mangoes at post-climacteric ripening phase offer the highest concentrations of health-promoting compounds. Peel, at this stage of fruit ripening, could be exploited as a good source for extraction of these compounds. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Oral cadmium chloride intoxication in mice: Effects of penicillamine, dimercaptosuccinic acid and related compounds

    International Nuclear Information System (INIS)

    Andersen, O.; Nielsen, J.B.

    1988-01-01

    The antidotal efficacies of chelators during acute cadmium intoxication has previously been examined in experiments where both a soluble cadmium salt and the chelator were administered parenterally. In the present study, PA, DMSA and related compounds were studied as oral antidotes during oral CdCl 2 intoxication. According to the antagonistic effects noted on mortality, peristaltic toxicity and intestinal cadmium uptake, the relative efficacies of the compounds tested were: DMSA>PAD>DMPS>MSA>PA>NAPA. None of the chelators induced major changes in the organ distribution of absorbed cadmium, in particular no increased cerebral deposition of cadmium. This study indicates that, in oral cadmium intoxication in humans, orally administered DMSA would be likely to offer protection against the local toxicity of cadmium in the gastrointestinal tract as well as to reduce the risk of systemic toxicity of absorbed cadmium. (author)

  7. Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media

    Directory of Open Access Journals (Sweden)

    Ebadi Mehdi

    2012-12-01

    Full Text Available Abstract Background The corrosion inhibition performance of pyrazolylindolenine compounds, namely 4-(3,3-dimethyl-3H-indol-2-yl-pyrazole-1-carbothioamide (InPzTAm, 4-(3,3-dimethyl-3H-indol-2-yl-1H-pyrazole-1-carbothiohydrazide (InPzTH and 3,3-dimethyl-2-(1-phenyl-1H-pyrazol-4-yl-3H-indole (InPzPh, on copper in 1M HCl solution is investigated by electrochemical impedance spectroscopy (EIS, open circuit potential (OCP and linear scan voltammetry (LSV techniques. Results The results show that the corrosion rate of copper is diminished by the compounds with the inhibition strength in the order of: InPzTAm> InPzTH > InPzPh. The corrosion inhibition efficiencies for the three inhibitors are 94.0, 91.4 and 79.3, for InPzTAm, InPzTH and InPzPh respectively with the same inhibitor concentration (2 mM. Conclusion From the EIS, OCP and LSV results it was concluded that pyrazolylindolenine compounds with S-atom (with an amine group have illustrated better corrosion inhibition performance compared to hydrazine and phenyl group.

  8. Mixtures of Quaternary Ammonium Compounds and Long-chain Fatty Acids as Antifungal Agents

    Science.gov (United States)

    Kull, F. C.; Eisman, P. C.; Sylwestrowicz, H. D.; Mayer, R. L.

    1961-01-01

    The influence of undecylenic acid on the fungistatic effect of phenoxyethyldimethyldodecylammonium bromide (Domiphen bromide) against Trichophyton mentagrophytes was investigated. The unsaturated fatty acid was found to enhance the fungistatic activity of Domiphen bromide against this organism. The ratio of concentrations of these agents has a marked influence on the results of in vitro tests for antifungal action resulting in a completely different effect than heretofore noted in combination experiments against bacteria. The enhancing phenomenon is not particular to T. mentagrophytes, it was observed also with Candida albicans. PMID:14460466

  9. Accumulation of Phenolic Compounds and Expression Profiles of Phenolic Acid Biosynthesis-Related Genes in Developing Grains of White, Purple, and Red Wheat.

    Science.gov (United States)

    Ma, Dongyun; Li, Yaoguang; Zhang, Jian; Wang, Chenyang; Qin, Haixia; Ding, Huina; Xie, Yingxin; Guo, Tiancai

    2016-01-01

    Polyphenols in whole grain wheat have potential health benefits, but little is known about the expression patterns of phenolic acid biosynthesis genes and the accumulation of phenolic acid compounds in different-colored wheat grains. We found that purple wheat varieties had the highest total phenolic content (TPC) and antioxidant activity. Among phenolic acid compounds, bound ferulic acid, vanillic, and caffeic acid levels were significantly higher in purple wheat than in white and red wheat, while total soluble phenolic acid, soluble ferulic acid, and vanillic acid levels were significantly higher in purple and red wheat than in white wheat. Ferulic acid and syringic acid levels peaked at 14 days after anthesis (DAA), whereas p-coumaric acid and caffeic acid levels peaked at 7 DAA, and vanillic acid levels gradually increased during grain filling and peaked near ripeness (35 DAA). Nine phenolic acid biosynthesis pathway genes (TaPAL1, TaPAL2, TaC3H1, TaC3H2, TaC4H, Ta4CL1, Ta4CL2, TaCOMT1, and TaCOMT2) exhibited three distinct expression patterns during grain filling, which may be related to the different phenolic acids levels. White wheat had higher phenolic acid contents and relatively high gene expression at the early stage, while purple wheat had the highest phenolic acid contents and gene expression levels at later stages. These results suggest that the expression of phenolic acid biosynthesis genes may be closely related to phenolic acids accumulation.

  10. One step hydrogenation–esterification of model compounds and bio-oil to alcohols and esters over Raney Ni catalysts

    International Nuclear Information System (INIS)

    Xu, Ying; Zhang, Limin; Chang, Jiamin; Zhang, Xinghua; Ma, Longlong; Wang, Tiejun; Zhang, Qi

    2016-01-01

    Highlights: • Fe–RN and Mo–RN showed excellent inhibition of alkylation and hydrogenation activity of phenol respectively. • The esterification activity of alcohols with acetic acid was followed as methanol > THFA > ethanediol. • After OHE of bio-oil, the total content of alcohols and esters reached to 87.27% in the product. - Abstract: Acids, aldehydes, ketones and phenols, which are the main components of bio-oil, have negative effects on the properties. In this paper, the mixture of acetic acid, furfural, hydroxyacetone, ethanediol, phenol and water were chosen as hybrid model compounds of bio-oil (MCB). To convert these compounds into stable and combustible oxygenated organics (alcohols and esters), one step hydrogenation–esterification (OHE) was carried out over Raney Ni catalyst (RN) and Mo, Sn, Fe, Cu modified Raney Ni catalysts (RNs) in the presence of methanol. 100% conversions of furfural and hydroxyacetone were achieved over RNs with high selectivity to desired products. The acetic acid conversion was only 35.1% with no methanol addition, while within 6 g/8 g methanol/MCB addition, the conversion of acetic acid increased to 81.1%. The esterification activity of alcohols was followed by methanol > tetrahydrofurfuryl alcohol (THFA), the hydrogenation product of furfural > ethanediol. Among the RNs, the addition of Fe catalyst restrained the aqueous-phase reforming of methanol and promoted the esterification of methanol and acetic acid. The Mo–RN showed the most favorable performance in the hydrogenation of phenol among the RNs. But the RN modified by both Fe and Mo did not give a good performance. After the OHE of light fraction of raw bio-oil over Mo–RN, there was no ketone & aldehyde detected and the contents of acids and phenols decreased from 49.04% and 7.35% to 8.21% and 3.84%. The conversion of acids could reach to 85.01% which was nearly to the conversion of acetic acid in MCB. The contents of alcohols and esters increased from 5

  11. Use of Shark Dental Protein to Estimate Trophic Position via Amino Acid Compound-Specific Isotope Analysis

    Science.gov (United States)

    Hayes, M.; Herbert, G.; Ellis, G.

    2017-12-01

    The diets of apex predators such as sharks are expected to change in response to overfishing of their mesopredator prey, but pre-anthropogenic baselines necessary to test for such changes are lacking. Stable isotope analysis (SIA) of soft tissues is commonly used to study diets in animals based on the bioaccumulation of heavier isotopes of carbon and nitrogen with increasing trophic level. In specimens representing pre-anthropogenic baselines, however, a modified SIA approach is needed to deal with taphonomic challenges, such as loss of soft tissues or selective loss of less stable amino acids (AAs) in other sources of organic compounds (e.g., teeth or bone) which can alter bulk isotope values. These challenges can be overcome with a compound-specific isotope analysis of individual AAs (AA-CSIA), but this first requires a thorough understanding of trophic enrichment factors for individual AAs within biomineralized tissues. In this study, we compare dental and muscle proteins of individual sharks via AA-CSIA to determine how trophic position is recorded within teeth and whether that information differs from that obtained from soft tissues. If skeletal organics reliably record information about shark ecology, then archaeological and perhaps paleontological specimens can be used to investigate pre-anthropogenic ecosystems. Preliminary experiments show that the commonly used glutamic acid/phenylalanine AA pairing may not be useful for establishing trophic position from dental proteins, but that estimated trophic position determined from alternate AA pairs are comparable to those from muscle tissue within the same species.

  12. Formation of volatile compounds in kefir made of goat and sheep milk with high polyunsaturated fatty acid content.

    Science.gov (United States)

    Cais-Sokolińska, D; Wójtowski, J; Pikul, J; Danków, R; Majcher, M; Teichert, J; Bagnicka, E

    2015-10-01

    This article explored the formation of volatile compounds during the production of kefir from goat and sheep milks with high polyunsaturated fatty acids (PUFA) as a result of feeding animals forage supplemented with maize dried distillers grains with solubles (DDGS). The increased PUFA content of the goat and sheep milks resulted in significant changes to the fermentation process. In particular, apart from an increase in the time taken to ferment sheep milk, fermentation yielded less 2,3-butanedione. The highest quantities of this compound were assayed in kefir produced from goat milk with an increased content of PUFA. An increase of PUFA significantly elevated ethanal synthesis during lactose-alcohol fermentation of sheep milk. Neither the origin of milk (sheep or goat) nor the level of PUFA had any statistical effect on the amount of ethanal assayed during the fermentation of milk and within the finished product. The proportion of l(+)-lactic acid was higher in kefirs produced using goat milk compared with sheep milk and did not depend on the content of PUFA in milk fat. The content of PUFA had a significant effect on the aroma profile of the resulting kefirs. An increase in PUFA content resulted in the loss of whey aroma in goat milk kefirs and the animal odor in sheep milk kefirs, and a creamy aroma became more prevalent in kefirs made from sheep milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Evaluation of Antioxidant Activity, Polyphenolic Compounds, Amino Acids and Mineral Elements of Representative Genotypes of Lonicera edulis

    Directory of Open Access Journals (Sweden)

    Jiri Sochor

    2014-05-01

    Full Text Available The aim of this study was to evaluate the bioactive substances in 19 berry cultivars of edible honeysuckle (Lonicera edulis. A statistical evaluation was used to determine the relationship between the content of selected bioactive substances and individual cultivars. Regarding mineral elements, the content of sodium was measured using potentiometry and spectrophotometry. The content of selected polyphenolic compounds with high antioxidant activity was determined by a HPLC–UV/ED method. The total amount of polyphenols was determined by the Folin-Ciocalteu method. The antioxidant activity was determined using five methods (DPPH, FRAP, ABTS, FR and DMPD that differ in their principles. The content of 13 amino acids was determined by ion-exchange chromatography. The experimental results obtained for the different cultivars were evaluated and compared by statistical and bioinformatic methods. A unique feature of this study lies in the exhaustive analysis of the chosen parameters (amino acids, mineral elements, polyphenolic compounds and antioxidant activity during one growing season.

  14. Biofilm formation is not a prerequisite for production of the antibacterial compound tropodithietic acid in Phaeobacter inhibens DSM17395

    DEFF Research Database (Denmark)

    Prol García, María Jesús; D'Alvise, Paul; Rygaard, Anita Mac

    2014-01-01

    Aims The goal of this study was to investigate if biofilm formation on population level is a physiological requirement for antagonism in Phaeobacter inhibens DSM17395, since the antibiotic compound tropodithietic acid (TDA) is produced by several Roseobacter clade species during growth as multice......Aims The goal of this study was to investigate if biofilm formation on population level is a physiological requirement for antagonism in Phaeobacter inhibens DSM17395, since the antibiotic compound tropodithietic acid (TDA) is produced by several Roseobacter clade species during growth...... as multicellular aggregates or biofilms at the air–liquid interface and is induced on single cell level upon attachment. Methods and Results A mutant library was created by Tn5 transposon insertion and 22 TDA-positive (brown) mutants with decreased biofilm formation or adhesion, and eight TDA-negative (white...... that are likely involved in EPS/LPS production, motility and chemotaxis, and redox regulation play a role in biofilm formation and/or adhesion in P. inhibens DSM17395. Conclusions Cell aggregation and biofilm formation are not physiological prerequisites for TDA production. Significance and Impact of the Study...

  15. Increased urinary imidazolepropionic acid, n-acetylhistamine and other imidazole compounds in patients with intestinal disorders

    NARCIS (Netherlands)

    Heiden, C. van der; Wadman, S.K.; Bree, P.K. de; Wauters, E.A.K.

    In 26 out of a large group of patients with gastrointestinal disorders abnormal urinary imidazole excretion patterns were found. Most frequently excessive or increased amounts of imidazolepropionic acid (ImPA) occurred, and as next N-acetylhistamine was excreted in excess. In a number of cases the

  16. Application of HPLC capacity coefficients to characterize the sorption of polycyclic aromatic compounds to humic acid

    DEFF Research Database (Denmark)

    Nielsen, T.; Helweg, C.; Siigur, K.

    1997-01-01

    The sorption coefficients to humic acid of 46 PAC having a wide range in polarity were compared with the capacity coefficients of the PAC to a non-polar HPLC column material (ODS) and a polar one (Diol). It is shown that polar interactions contribute to the sorption of polar PAC in addition...

  17. A modeling approach for compounds affecting body composition.

    Science.gov (United States)

    Gennemark, Peter; Jansson-Löfmark, Rasmus; Hyberg, Gina; Wigstrand, Maria; Kakol-Palm, Dorota; Håkansson, Pernilla; Hovdal, Daniel; Brodin, Peter; Fritsch-Fredin, Maria; Antonsson, Madeleine; Ploj, Karolina; Gabrielsson, Johan

    2013-12-01

    Body composition and body mass are pivotal clinical endpoints in studies of welfare diseases. We present a combined effort of established and new mathematical models based on rigorous monitoring of energy intake (EI) and body mass in mice. Specifically, we parameterize a mechanistic turnover model based on the law of energy conservation coupled to a drug mechanism model. Key model variables are fat-free mass (FFM) and fat mass (FM), governed by EI and energy expenditure (EE). An empirical Forbes curve relating FFM to FM was derived experimentally for female C57BL/6 mice. The Forbes curve differs from a previously reported curve for male C57BL/6 mice, and we thoroughly analyse how the choice of Forbes curve impacts model predictions. The drug mechanism function acts on EI or EE, or both. Drug mechanism parameters (two to three parameters) and system parameters (up to six free parameters) could be estimated with good precision (coefficients of variation typically mass and FM changes at different drug provocations using a similar model for man. Surprisingly, model simulations indicate that an increase in EI (e.g. 10 %) was more efficient than an equal lowering of EI. Also, the relative change in body mass and FM is greater in man than in mouse at the same relative change in either EI or EE. We acknowledge that this assumes the same drug mechanism impact across the two species. A set of recommendations regarding the Forbes curve, vehicle control groups, dual action on EI and loss, and translational aspects are discussed. This quantitative approach significantly improves data interpretation, disease system understanding, safety assessment and translation across species.

  18. A new synthetic granular calcium phosphate compound induces new bone in a sinus lift rabbit model.

    Science.gov (United States)

    Trbakovic, Amela; Hedenqvist, Patricia; Mellgren, Torbjörn; Ley, Cecilia; Hilborn, Jöns; Ossipov, Dmitri; Ekman, Stina; Johansson, Carina B; Jensen-Waern, Marianne; Thor, Andreas

    2018-03-01

    The aim of this study was to investigate if a synthetic granular calcium phosphate compound (CPC) and a composite bisphosphonate-linked hyaluronic acid-calcium phosphate hydrogel (HABP·CaP) induced similar or more amount of bone as bovine mineral in a modified sinus lift rabbit model. Eighteen adult male New Zeeland White rabbits, received randomly one of the two test materials on a random side of the face, and bovine mineral as control on the contralateral side. In a sinus lift, the sinus mucosa was elevated and a titanium mini-implant was placed in the alveolar bone. Augmentation material (CPC, HABP·CaP or bovine bone) was applied in the space around the implant. The rabbits were euthanized three months after surgery and qualitative and histomorphometric evaluation were conducted. Histomorphometric evaluation included three different regions of interest (ROIs) and the bone to implant contact on each installed implant. Qualitative assessment (p = <.05), histomorphometric evaluations (p = < .01), and implant incorporation (p = <.05) showed that CPC and bovine mineral induced similar amount of bone and more than the HABP·CaP hydrogel. CPC induced similar amount of bone as bovine mineral and both materials induced more bone than HABP·CaP hydrogel. The CPC is suggested as a synthetic alternative for augmentations in the maxillofacial area. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Metabolism of Seriola lalandi during Starvation as Revealed by Fatty Acid Analysis and Compound-Specific Analysis of Stable Isotopes within Amino Acids.

    Directory of Open Access Journals (Sweden)

    Fernando Barreto-Curiel

    Full Text Available Fish starvation is defined as food deprivation for a long period of time, such that physiological processes become confined to basal metabolism. Starvation provides insights in physiological processes without interference from unknown factors in digestion and nutrient absorption occurring in fed state. Juveniles of amberjack Seriola lalandi were isotopically equilibrated to a formulated diet for 60 days. One treatment consisted of fish that continued to be fed and fish in the other treatment were not fed for 35 days. The isotopic signatures prior to the beginning of and after the starvation period, for fish in the starvation and control treatments, were analysed for lipid content, fatty acid composition and isotopic analysis of bulk (EA-IRMS and of amino acids (compound specific isotope analysis, CSIA. There were three replicates for the starvation group. Fatty acid content in muscle and liver tissue before and after starvation was determined to calculate percent change. Results showed that crude lipid was the most used source of energy in most cases; the PUFAs and LC-PUFAs were highly conserved. According to the protein signature in bulk (δ15N and per amino acid (δ13C and δ15N, in muscle tissue, protein synthesis did not appear to occur substantially during starvation, whereas in liver, increases in δ13C and δ15N indicate that protein turnover occurred, probably for metabolic routing to energy-yielding processes. As a result, isotopic values of δ15N in muscle tissue do not change, whereas CSIA net change occurred in the liver tissue. During the study period of 35 days, muscle protein was largely conserved, being neither replenished from amino acid pools in the plasma and liver nor catabolized.

  20. Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

    2015-07-15

    Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

  1. A computational study of pyrolysis reactions of lignin model compounds

    Science.gov (United States)

    Thomas Elder

    2010-01-01

    Enthalpies of reaction for the initial steps in the pyrolysis of lignin have been evaluated at the CBS-4m level of theory using fully substituted b-O-4 dilignols. Values for competing unimolecular decomposition reactions are consistent with results previously published for phenethyl phenyl ether models, but with lowered selectivity. Chain propagating reactions of free...

  2. Phosphorus compounds, proteins, nuclease and acid phosphatase activities in isolated spinach chloroplasts

    Directory of Open Access Journals (Sweden)

    E. Mikulska

    2015-01-01

    Full Text Available This paper deals with attempts to elaborate a simple method of spinach chloroplast isolation ensuring a high proportion of intact chloroplasts. We obtained 3 preparations of isolated chloroplasts. Several preliminary analyses of the obtained chloroplast fraction were also performed. Phosphorus compounds, total protein and the enzyme activities of RNase, DNase and GPase were determined. We found: 0,36-0,59% of RNA, 0,19-0,24% of DNA, 2,1-2,9% of phospholipids and 26-28% of protein. RNase activity was very high.

  3. Cell motility is inhibited by the antiepileptic compound, valproic acid and its teratogenic analogues

    DEFF Research Database (Denmark)

    Walmod, P S; Foley, A; Berezin, A

    1998-01-01

    -term recordings and measurements of mean-cell speed, the reduction in the motile behaviour was shown to correlate with the teratogenic potency of the tested compounds. The observed effects of VPA on cell motility was independent of the employed L-cell clone, and could be reproduced in cells containing...... the neuronal marker NCAM and in the neuronal cell line N2a. Furthermore, the observed effect was independent of culture substratum, being observed for L-cells grown on fibronectin as well as on plastic. Immunofluorescence microscopy revealed that VPA-treatment of mouse L-cells caused a redistribution of F...

  4. Incidence of nitrogenous compounds of must on ethyl carbamate formation induced by lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    José Antonio Suárez Lepe

    2007-12-01

    Significance and impact of study: The composition of the nitrogen status of must has frequently been said to be a factor of concern on the final urethane concentration of wines. High contents of arginine coming from over fertilised vineyards are known to render significant levels of urea after alcoholic fermentation if conducted by arginase (+ yeast strains. This urea is always likely to undergo ethanolysis. No significant correlations were found between any of the nitrogenous compounds tested and final EC. High levels of arginine in the starting must did not lead to greater EC concentrations in the resulting wines.

  5. Adjuvant effects and antiserum action potentiation by a (herbal) compound 2-hydroxy-4-methoxy benzoic acid isolated from the root extract of the Indian medicinal plant 'sarsaparilla' (Hemidesmus indicus R. Br.).

    Science.gov (United States)

    Alam, M I; Gomes, A

    1998-10-01

    The adjuvant effect and antiserum potentiation of a compound 2-hydroxy-4-methoxy benzoic acid were explored in the present investigation. This compound, isolated and purified from the Indian medicinal plant Hemidesmus indicus R. Br, possessed antisnake venom activity. Rabbits immunized with Vipera russellii venom in the presence and absence of the compound along with Freund's complete adjuvant, produced a precipitating band in immunogel diffusion and immunogel electrophoresis. The venom neutralizing capacity of this antiserum showed positive adjuvant effects as evident by the higher neutralization capacity (lethal and hemorrhage) when compared with the antiserum raised with venom alone. The pure compound potentiated the lethal action neutralization of venom by commercial equine polyvalent snake venom antiserum in experimental models. These observations raised the possibility of the use of chemical antagonists (from herbs) against snake bite, which may provide a better protection in presence of antiserum, especially in the rural parts of India.

  6. Day–Night Changes of Energy-rich Compounds in Crassulacean Acid Metabolism (CAM) Species Utilizing Hexose and Starch

    Science.gov (United States)

    CHEN, LI-SONG; NOSE, AKIHIRO

    2004-01-01

    • Background and Aims Plants with crassulacean acid metabolism (CAM) can be divided into two groups according to the major carbohydrates used for malic acid synthesis, either polysaccharide (starch) or monosaccharide (hexose). This is related to the mechanism and affects energy metabolism in the two groups. In Kalanchoë pinnata and K. daigremontiana, which utilize starch, ATP-dependent phosphofructokinase (tonoplast inorganic pyrophosphatase) activity is greater than inorganic pyrophosphate-dependent phosphofructokinase (tonoplast adenosine triphosphatase) activity, but the reverse is the case in pineapple (Ananas comosus) utilizing hexose. To test the hypothesis that the energy metabolism of the two groups differs, day-night changes in the contents of ATP, ADP, AMP, inorganic phosphate (Pi), phosphoenolpyruvate (PEP) and inorganic pyrophosphate (PPi) in K. pinnata and K. daigremontiana leaves and in pineapple chlorenchyma were analysed. • Methods The contents of energy-rich compounds were measured spectrophotometrically in extracts of tissue sampled in the light and dark, using potted plants, kept for 15 d before the experiments in a growth chamber. • Key Results In the three species, ATP content and adenylate energy charge (AEC) increased in the dark and decreased in the light, in contrast to ADP and AMP. Changes in ATP and AEC were greater in Kalanchoë leaves than in pineapple chlorenchyma. PPi content in the three species increased in the dark, but on illumination it decreased rapidly and substantially, remaining little changed through the rest of the light period. Pi content of Kalanchoë leaves did not change between dark and light, whereas Pi in pineapple chlorenchyma increased in the dark and decreased in the light, and the changes were far greater than in Kalanchoë leaves. Light-dark changes in PEP content in the three species were similar. • Conclusions These results corroborate our hypothesis that day–night changes in the contents of energy

  7. Day-night changes of energy-rich compounds in crassulacean acid metabolism (CAM) species utilizing hexose and starch.

    Science.gov (United States)

    Chen, Li-Song; Nose, Akihiro

    2004-09-01

    Plants with crassulacean acid metabolism (CAM) can be divided into two groups according to the major carbohydrates used for malic acid synthesis, either polysaccharide (starch) or monosaccharide (hexose). This is related to the mechanism and affects energy metabolism in the two groups. In Kalanchoë pinnata and K. daigremontiana, which utilize starch, ATP-dependent phosphofructokinase (tonoplast inorganic pyrophosphatase) activity is greater than inorganic pyrophosphate-dependent phosphofructokinase (tonoplast adenosine triphosphatase) activity, but the reverse is the case in pineapple (Ananas comosus) utilizing hexose. To test the hypothesis that the energy metabolism of the two groups differs, day-night changes in the contents of ATP, ADP, AMP, inorganic phosphate (Pi), phosphoenolpyruvate (PEP) and inorganic pyrophosphate (PPi) in K. pinnata and K. daigremontiana leaves and in pineapple chlorenchyma were analysed. The contents of energy-rich compounds were measured spectrophotometrically in extracts of tissue sampled in the light and dark, using potted plants, kept for 15 d before the experiments in a growth chamber. In the three species, ATP content and adenylate energy charge (AEC) increased in the dark and decreased in the light, in contrast to ADP and AMP. Changes in ATP and AEC were greater in Kalanchoë leaves than in pineapple chlorenchyma. PPi content in the three species increased in the dark, but on illumination it decreased rapidly and substantially, remaining little changed through the rest of the light period. Pi content of Kalanchoë leaves did not change between dark and light, whereas Pi in pineapple chlorenchyma increased in the dark and decreased in the light, and the changes were far greater than in Kalanchoë leaves. Light-dark changes in PEP content in the three species were similar. These results corroborate our hypothesis that day-night changes in the contents of energy-rich compounds differ between CAM species and are related to the

  8. Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

    Science.gov (United States)

    Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

    2012-11-01

    Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

  9. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Directory of Open Access Journals (Sweden)

    Miguel A Martín-Acebes

    Full Text Available West Nile virus (WNV is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu on the highly basic internal capsid or core (C protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  10. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Science.gov (United States)

    Martín-Acebes, Miguel A; Blázquez, Ana-Belén; de Oya, Nereida Jiménez; Escribano-Romero, Estela; Shi, Pei-Yong; Saiz, Juan-Carlos

    2013-01-01

    West Nile virus (WNV) is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu) on the highly basic internal capsid or core (C) protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A) and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  11. Exome sequencing and SNP analysis detect novel compound heterozygosity in fatty acid hydroxylase-associated neurodegeneration

    Science.gov (United States)

    Pierson, Tyler Mark; Simeonov, Dimitre R; Sincan, Murat; Adams, David A; Markello, Thomas; Golas, Gretchen; Fuentes-Fajardo, Karin; Hansen, Nancy F; Cherukuri, Praveen F; Cruz, Pedro; Blackstone, Craig; Tifft, Cynthia; Boerkoel, Cornelius F; Gahl, William A

    2012-01-01

    Fatty acid hydroxylase-associated neurodegeneration due to fatty acid 2-hydroxylase deficiency presents with a wide range of phenotypes including spastic paraplegia, leukodystrophy, and/or brain iron deposition. All previously described families with this disorder were consanguineous, with homozygous mutations in the probands. We describe a 10-year-old male, from a non-consanguineous family, with progressive spastic paraplegia, dystonia, ataxia, and cognitive decline associated with a sural axonal neuropathy. The use of high-throughput sequencing techniques combined with SNP array analyses revealed a novel paternally derived missense mutation and an overlapping novel maternally derived ∼28-kb genomic deletion in FA2H. This patient provides further insight into the consistent features of this disorder and expands our understanding of its phenotypic presentation. The presence of a sural nerve axonal neuropathy had not been previously associated with this disorder and so may extend the phenotype. PMID:22146942

  12. The use of L-ascorbic acid in speciation of arsenic compounds in drinking water

    Directory of Open Access Journals (Sweden)

    Marjanović Nikola J.

    2009-01-01

    Full Text Available Arsenic speciation, besides total arsenic content determination, is very important in analysis of water, foodstuffs, and environmental samples, because of varying degrees of toxicity of different species. For such purpose hydride generation atomic absorption spectrometry can be used based on the generation of certain types of hydride, depending on the pH value and pretreatment in different reaction media. In this study, we have investigated the effect of L-ascorbic acid as the reaction medium as well as the pre-reducing agent in speciation of arsenic by hydride generation-atomic absorption spectrometry in order to determine monomethyl arsonic acid (MMA in the presence of inorganic forms of arsenic.

  13. Quinolinic Carboxylic Acid Derivatives as Potential Multi-target Compounds for Neurodegeneration: Monoamine Oxidase and Cholinesterase Inhibition.

    Science.gov (United States)

    Khan, Nehal A; Khan, Imtiaz; Abid, Syed M A; Zaib, Sumera; Ibrar, Aliya; Andleeb, Hina; Hameed, Shahid; Iqbal, Jamshed

    2018-01-01

    Parkinson's disease (PD), a debilitating and progressive disorder, is among the most challenging and devastating neurodegenerative diseases predominantly affecting the people over 60 years of age. To confront PD, an advanced and operational strategy is to design single chemical functionality able to control more than one target instantaneously. In this endeavor, for the exploration of new and efficient inhibitors of Parkinson's disease, we synthesized a series of quinoline carboxylic acids (3a-j) and evaluated their in vitro monoamine oxidase and cholinesterase inhibitory activities. The molecular docking and in silico studies of the most potent inhibitors were performed to identify the probable binding modes in the active site of the monoamine oxidase enzymes. Moreover, molecular properties were calculated to evaluate the druglikeness of the compounds. The biological evaluation results revealed that the tested compounds were highly potent against monoamine oxidase (A & B), 3c targeted both the isoforms of MAO with IC50 values of 0.51 ± 0.12 and 0.51 ± 0.03 µM, respectively. The tested compounds also demonstrated high and completely selective inhibitory action against acetylcholinesterase (AChE) with IC50 values ranging from 4.36 to 89.24 µM. Among the examined derivatives, 3i was recognized as the most potent inhibitor of AChE with an IC50 value of 4.36 ± 0.12 ±µM. The compounds appear to be promising inhibitors and could be used for the future development of drugs targeting neurodegenerative disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Model radioisotope experiments on the influence of acid rain on 65Zn binding with humic acid

    International Nuclear Information System (INIS)

    Koczorowska, E.; Mieloch, M.; Slawinski, J.

    2002-01-01

    Acid rain formed first of all from sulfur oxide emitted by natural and anthropogenic sources, may change the biological equilibrium and the metal stoppage in the soil. The model experiments were performed to determine the influence of acid rain on zinc bond with humic acid (HA). The samples were prepared in glass columns with quartz sand and overlaid HA or HA + 65 Zn radioisotope that simulates natural conditions. Then, solutions of H 2 SO 4 were introduced into the sand - HA layer. Zinc was washed with diluted (10 -4 - 10 -3 M) sulphuric acid as a simulation of acid rain. The results help to evaluate the migration behaviour of zinc in the presence of HA and H 2 SO 4 . The model studies illustrate the considerable influence of sulfuric acid on chemical degradation of HA. (author)

  15. Chromatographic retention prediction and octanol-water partition coefficient determination of monobasic weak acidic compounds in ion-suppression reversed-phase liquid chromatography using acids as ion-suppressors.

    Science.gov (United States)

    Ming, Xin; Han, Shu-ying; Qi, Zheng-chun; Sheng, Dong; Lian, Hong-zhen

    2009-08-15

    Although simple acids, replacing buffers, have been widely applied to suppress the ionization of weakly ionizable acidic analytes in reversed-phase liquid chromatography (RPLC), none of the previously reported works focused on the systematic studies about the retention behavior of the acidic solutes in this ion-suppression RPLC mode. The subject of this paper was therefore to investigate the retention behavior of monobasic weak acidic compounds using acetic, perchloric and phosphoric acids as the ion-suppressors. The apparent octanol-water partition coefficient (K" ow) was proposed to calibrate the octanol-water partition coefficient (K(ow)) of these weak acidic compounds, which resulted in a better linear correlation with log k(w), the logarithm of the hypothetical retention factor corresponding to neat aqueous fraction of hydroorganic mobile phase. This log K" ow-log k w linear correlation was successfully validated by the results of monocarboxylic acids and monohydrating phenols, and moreover by the results under diverse experimental conditions for the same solutes. This straightforward relationship not only can be used to effectively predict the retention values of weak acidic solutes combined with Snyder-Soczewinski equation, but also can offer a promising medium for directly measuring K(ow) data of these compounds via Collander equation. In addition, the influence of the different ion-suppressors on the retention of weak acidic compounds was also compared in this RPLC mode.

  16. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    International Nuclear Information System (INIS)

    Ezerskaya, N.A.; Buj Kuang Ki; Shubochkin, L.K.

    1987-01-01

    In the process of interaction of K 2 Ru(H 2 O)Cl 5 with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H 8 EDTP) Ru 3 mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl - , H 2 O) coordination. Ru 3 complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied

  17. Global emissions and models of photochemically active compounds

    International Nuclear Information System (INIS)

    Penner, J.E.; Atherton, C.S.; Graedel, T.E.

    1993-01-01

    Anthropogenic emissions from industrial activity, fossil fuel combustion, and biomass burning are now known to be large enough (relative to natural sources) to perturb the chemistry of vast regions of the troposphere. A goal of the IGAC Global Emissions Inventory Activity (GEIA) is to provide authoritative and reliable emissions inventories on a 1 degree x 1 degree grid. When combined with atmospheric photochemical models, these high quality emissions inventories may be used to predict the concentrations of major photochemical products. Comparison of model results with measurements of pertinent species allows us to understand whether there are major shortcomings in our understanding of tropospheric photochemistry, the budgets and transport of trace species, and their effects in the atmosphere. Through this activity, we are building the capability to make confident predictions of the future consequences of anthropogenic emissions. This paper compares IGAC recommended emissions inventories for reactive nitrogen and sulfur dioxide to those that have been in use previously. We also present results from the three-dimensional LLNL atmospheric chemistry model that show how emissions of anthropogenic nitrogen oxides might potentially affect tropospheric ozone and OH concentrations and how emissions of anthropogenic sulfur increase sulfate aerosol loadings

  18. Characterization of volatile compounds produced by Lactobacillus helveticus strains in a hard cheese model.

    Science.gov (United States)

    Cuffia, Facundo; Bergamini, Carina V; Wolf, Irma V; Hynes, Erica R; Perotti, María C

    2018-01-01

    Starter cultures of Lactobacillus helveticus used in hard cooked cheeses play an important role in flavor development. In this work, we studied the capacity of three strains of L. helveticus, two autochthonous (Lh138 and Lh209) and one commercial (LhB02), to grow and to produce volatile compounds in a hard cheese extract. Bacterial counts, pH, profiles of organic acids, carbohydrates, and volatile compounds were analyzed during incubation of extracts for 14 days at 37 ℃. Lactobacilli populations were maintained at 10 6 CFU ml -1 for Lh138, while decreases of approx. 2 log orders were found for LhB02 and Lh209. Both Lh209 and LhB02 slightly increased the acetic acid content whereas mild increase in lactic acid was produced by Lh138. The patterns of volatiles were dependent on the strain which reflect their distinct enzymatic machineries: LhB02 and Lh209 produced a greater diversity of compounds, while Lh138 was the least producer strain. Extracts inoculated with LhB02 and Lh 209 were characterized by ketones, esters, alcohols, aldehydes, and acids, whereas in the extracts with Lh138 the main compounds belonged to aromatic, aldehydes, and ketones groups. Therefore, Lh209 and LhB02 could represent the best cheese starters to improve and intensify the flavor, and even a starter composed by combinations of LhB02 or Lh209 with Lh138 could also be a strategy to diversify cheese flavor.

  19. Study of the effects of radiation of nucleic acids and related compounds. Progress report, August 15, 1975--August 14, 1976

    International Nuclear Information System (INIS)

    Wang, S.Y.

    1976-04-01

    Ionizing radiation produces genetic effects in biological systems. Since genetic effects are usually the result of modifications of DNA or sometimes of RNA, interest is being centered on the chemical and physical nature of radiation-induced lesions to nucleic acids and their components. These investigations have revealed the enormous complexity of chemical events and the possible degradation of nucleic acids by strand breakage. Therefore, work in the ionization radiation of nucleic acids has proceeded along a dual course. On the one hand, molecular changes have been characterized for a number of primary radiation products. On the other hand, strand breakage has been investigated intensively as a direct primary event. Both of these aspects were emphasized in our research last year. We succeeded in improving the synthesis of 5-hydroxy-methyl thymine (α-TOOH). α-TOOH was found to be much more effective than cis-5,6-dihydro-6-hydroperoxy-5-hydroxy thymine (6-TOOH) in the inactivation of transforming DNA of H. influenzae cells although α-TOOH is much less reactive chemically than 6-TOOH. 6-TOOH causes inactivation and acts as an inhibitor of DNA synthesis in mammalian cells. In addition, evidence may indicate that 6-TOOH does not induce strand breaks directly in DNA although we showed that 6-TOOH is a clastogenic compound

  20. A detailed chemical kinetic model for pyrolysis of the lignin model compound chroman

    Directory of Open Access Journals (Sweden)

    James Bland

    2013-12-01

    Full Text Available The pyrolysis of woody biomass, including the lignin component, is emerging as a potential technology for the production of renewable fuels and commodity chemicals. Here we describe the construction and implementation of an elementary chemical kinetic model for pyrolysis of the lignin model compound chroman and its reaction intermediate ortho-quinone methide (o-QM. The model is developed using both experimental and theoretical data, and represents a hybrid approach to kinetic modeling that has the potential to provide molecular level insight into reaction pathways and intermediates while accurately describing reaction rates and product formation. The kinetic model developed here can replicate all known aspects of chroman pyrolysis, and provides new information on elementary reaction steps. Chroman pyrolysis is found to proceed via an initial retro-Diels–Alder reaction to form o-QM + ethene (C2H4, followed by dissociation of o-QM to the C6H6 isomers benzene and fulvene (+ CO. At temperatures of around 1000–1200 K and above fulvene rapidly isomerizes to benzene, where an activation energy of around 270 kJ mol-1 is required to reproduce experimental observations. A new G3SX level energy surface for the isomerization of fulvene to benzene supports this result. Our modeling also suggests that thermal decomposition of fulvene may be important at around 950 K and above. This study demonstrates that theoretical protocols can provide a significant contribution to the development of kinetic models for biomass pyrolysis by elucidating reaction mechanisms, intermediates, and products, and also by supplying realistic rate coefficients and thermochemical properties.

  1. Urethral orifice hyaluronic acid injections: a novel animal model of bladder outlet obstruction.

    Science.gov (United States)

    Wang, Yongquan; Xiong, Zhiyong; Gong, Wei; Zhou, Zhansong; Lu, Gensheng

    2015-02-21

    We produced a novel model of bladder outlet obstruction (BOO) by periurethral injection of hyaluronic acid and compared the cystometric features, postoperative complications, and histopathological changes of that model with that of traditional open surgery. Forty female Sprague-Dawley rats were divided into three groups. Fifteen rats were subcutaneously injected with 0.2 ml hyaluronic acid at 5, 7, and 12 o'clock around the urethral orifice. Another fifteen rats underwent traditional open partial proximal urethral obstruction surgery, and 10 normal rats used as controls. After 4 weeks, filling cystometry, postoperative complications, and histopathological features were evaluated in each group. Three rats were also observed for 12 weeks after hyaluronic acid injection to evaluate the long-term effect. Hyaluronic acid periurethral injection caused increased maximum cystometric capacity, maximum bladder pressure, micturition interval, and post-void residual urine volume compared with control (p injection group had significantly shorter operative time, less incidence of incision infection and bladder stone formation compared with the surgery group (p injection and surgery bladders; these were not observed in the control group. Bladder weight and thickness of smooth muscle in the injection and surgery groups were significantly greater than those in the control group (p injection or control groups. Rats periurethrally injected hyaluronic acid were stable the compound was not fully absorbed in any rat after 12 weeks. Hyaluronic acid periurethral injection generates a simple, effective, and persistent animal model of BOO with lower complications, compared with traditional surgery.

  2. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Ezerskaya, N A; Ki, Buj Kuang; Shubochkin, L K

    1987-12-01

    In the process of interaction of K/sub 2/Ru(H/sub 2/O)Cl/sub 5/ with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H/sub 8/EDTP) Ru/sup 3/ mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl/sup -/, H/sub 2/O) coordination. Ru/sup 3/ complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied.

  3. Crystal structures of thiosemicarbazide diacetic acid and coordination compounds on its basis

    International Nuclear Information System (INIS)

    Burshtejn, I.F.; Petukhov, L.I.; Gehrbehlehu, N.V.; Volodina, G.F.; Bologa, O.A.

    1985-01-01

    Results of X-ray structure investigation of thiosemicarbazide diacetic acid (H 2 tscda) and its complex derivatives of the composition Mtscda (M=Cd, Co, Cu) have been reviewed. Structure characteristics of Cdtscdax4H 2 O are as follows: a=14.513, b=8.648, c=9.871 A, γ=98.46 deg, sp.gr. P2 1 /a, z=4. Cadmium complex structure represents a centrosymmetrical dimer with bridge oxygen atom of carboxylic group. Cd-Cd distance is 3.815 A. Cd atom has coordination number 7. Coordination Cd-polyhedron in the structure has configuration of trigonal one-cap prism

  4. Ambient air monitoring for organic compounds, acids, and metals at Los Alamos National Laboratory, January 1991

    International Nuclear Information System (INIS)

    Williams, C.H.; Eberhart, C.F.

    1992-01-01

    Los Alamos National Laboratory (LANL) contracted Radian Corporation (Radian) to conduct a short-term, intensive air monitoring program whose goal was to estimate the impact of chemical emissions from LANL on the ambient air environment. A comprehensive emission inventory had identified more than 600 potential air contaminants in LANL's emissions. A subset of specific target chemicals was selected for monitoring: 20 organic vapors, 6 metals and 5 inorganic acid vapors. These were measured at 5 ground level sampling sites around LANL over seven consecutive days in January 1991. The sampling and analytical strategy used a combination of EPA and NIOSH methods modified for ambient air applications

  5. A synergistic antiproliferation effect of curcumin and docosahexaenoic acid in SK-BR-3 breast cancer cells: unique signaling not explained by the effects of either compound alone

    International Nuclear Information System (INIS)

    Altenburg, Jeffrey D; Bieberich, Andrew A; Terry, Colin; Harvey, Kevin A; VanHorn, Justin F; Xu, Zhidong; Jo Davisson, V; Siddiqui, Rafat A

    2011-01-01

    Breast cancer is a collection of diseases in which molecular phenotypes can act as both indicators and mediators of therapeutic strategy. Therefore, candidate therapeutics must be assessed in the context of multiple cell lines with known molecular phenotypes. Docosahexaenoic acid (DHA) and curcumin (CCM) are dietary compounds known to antagonize breast cancer cell proliferation. We report that these compounds in combination exert a variable antiproliferative effect across multiple breast cell lines, which is synergistic in SK-BR-3 cells and triggers cell signaling events not predicted by the activity of either compound alone. Dose response curves for CCM and DHA were generated for five breast cell lines. Effects of the DHA+ CCM combination on cell proliferation were evaluated using varying concentrations, at a fixed ratio, of CCM and DHA based on their individual ED 50 . Detection of synergy was performed using nonlinear regression of a sigmoid dose response model and Combination Index approaches. Cell molecular network responses were investigated through whole genome microarray analysis of transcript level changes. Gene expression results were validated by RT-PCR, and western blot analysis was performed for potential signaling mediators. Cellular curcumin uptake, with and without DHA, was analyzed via flow cytometry and HPLC. CCM+DHA had an antiproliferative effect in SK-BR-3, MDA-MB-231, MDA-MB-361, MCF7 and MCF10AT cells. The effect was synergistic for SK-BR-3 (ER - PR - Her2 + ) relative to the two compounds individually. A whole genome microarray approach was used to investigate changes in gene expression for the synergistic effects of CCM+DHA in SK-BR-3 cells lines. CCM+DHA triggered transcript-level responses, in disease-relevant functional categories, that were largely non-overlapping with changes caused by CCM or DHA individually. Genes involved in cell cycle arrest, apoptosis, inhibition of metastasis, and cell adhesion were upregulated, whereas genes

  6. Modelling uptake into roots and subsequent translocation of neutral and ionisable organic compounds

    DEFF Research Database (Denmark)

    Trapp, Stefan

    2000-01-01

    A study on uptake of neutral and dissociating organic compounds from soil solution into roots, and their subsequent translocation, was undertaken using model simulations. The model approach combines the processes of lipophilic sorption, electrochemical interactions, ion trap, advection in xylem...... and dilution by growth. It needs as input data, apart fromplant properties, log KOW, pKa and the valency number of the compound, and pH and chemical concentration in the soil solution. Equilibrium and dynamic (steady-state) models were tested against measured data from several authors, including non...

  7. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru; Le Roux, Julien; Zhang, Tao; Croue, Jean-Philippe

    2014-01-01

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

  8. Formation of brominated disinfection byproducts from natural organic matter isolates and model compounds in a sulfate radical-based oxidation process

    KAUST Repository

    Wang, Yuru

    2014-12-16

    A sulfate radical-based advanced oxidation process (SR-AOP) has received increasing application interest for the removal of water/wastewater contaminants. However, limited knowledge is available on its side effects. This study investigated the side effects in terms of the production of total organic bromine (TOBr) and brominated disinfection byproducts (Br-DBPs) in the presence of bromide ion and organic matter in water. Sulfate radical was generated by heterogeneous catalytic activation of peroxymonosulfate. Isolated natural organic matter (NOM) fractions as well as low molecular weight (LMW) compounds were used as model organic matter. Considerable amounts of TOBr were produced by SR-AOP, where bromoform (TBM) and dibromoacetic acid (DBAA) were identified as dominant Br-DBPs. In general, SR-AOP favored the formation of DBAA, which is quite distinct from bromination with HOBr/OBr- (more TBM production). SR-AOP experimental results indicate that bromine incorporation is distributed among both hydrophobic and hydrophilic NOM fractions. Studies on model precursors reveal that LMW acids are reactive TBM precursors (citric acid > succinic acid > pyruvic acid > maleic acid). High DBAA formation from citric acid, aspartic acid, and asparagine was observed; meanwhile aspartic acid and asparagine were the major precursors of dibromoacetonitrile and dibromoacetamide, respectively.

  9. Physicochemical properties, phenolic acids and volatile compounds of oil extracted from dry alhydwan (Boerhavia elegana Choisy seeds

    Directory of Open Access Journals (Sweden)

    Al-Farga, A.

    2015-09-01

    Full Text Available In this study, the chemical composition, physicochemical properties, phenolic acids and volatile compounds of alhydwan (Boerhavia elegana Choisy seed oil were evaluated. The crude oil content was 11.49%, ash 6.88%, moisture 6.12%, protein content 14.60%, total carbohydrate 24.77% and fiber 36.13%. The oil contain a high quantity of unsaturated fatty acids (74.63 mg·100 g−1 with oleic (C18:1 (57.77%, palmitic (C16:0 (18.65% and linoleic (C18:2 (12.88% acids as the most abundant. The relative density was 0.88 and the iodine value 105.59. The color analysis showed a value of 28.33 Y+1.43 R. The oil also had a high relative oxidative stability. The tocol composition showed that α-tocotrienol, γ-tocopherol and γ-tocotrienol were in a higher concentration than the rest. Seven phenolic acids (caffeic, vanillic, galic, p-coumaric, ascorbic, cinnamic and ferulic were detected, with ascorbic acid as the predominant one (5.44 mg·100 g−1. In relation to the volatile composition, 48 compounds were found with Z-10-Pentadecen-1-ol (56.73%; Hexadecenoic acid, Z-11- (18.52%; 9,12-Octadecadienoic acid (Z,Z- (3.93% and 9,12-Octadecadienoic acid (Z,Z-, 2-hydroxy-1-(hydroxymethyl ethyl ester (3.04% as the most abundant. These findings demonstrated the potential of alhydwan seeds to be used as a good source of quality edible oil.En este estudio se ha determinado la composición química, las propiedades físico-químicas, ácidos fenólicos y compuestos volátiles de aceites de semillas de alhydwan (Boerhavia elegana Choisy. Las semillas contenían un 11.49% de aceite, 6.88% de cenizas, 6,12% de humedad, 14.60% de proteínas, 24.77% de carbohidratos totales y 36.13% de fibra. El aceite contiene 74,63 mg·100 g−1 de ácidos grasos insaturados, con oleico (C18: 1 (57,77%, palmítico (C16: 0 (18,65% y linoleico (C18: 2 (12,88% como los más abundantes. La densidad relativa fue de 0,88 y el índice de yodo de 105,59. El análisis del color mostró un valor de

  10. Interaction between Al3+ and acrylic acid and polyacrylic acid in acidic aqueous solution: a model experiment for the behavior of Al3+ in acidified soil solution.

    Science.gov (United States)

    Etou, Mayumi; Masaki, Yuka; Tsuji, Yutaka; Saito, Tomoyuki; Bai, Shuqin; Nishida, Ikuko; Okaue, Yoshihiro; Yokoyama, Takushi

    2011-01-01

    From the viewpoint of the phytotoxicity and mobility of Al(3+) released from soil minerals due to soil acidification, the interaction between Al(3+) and acrylic acid (AA) and polyacrylic acid (PAA) as a model compound of fulvic acid was investigated. The interaction was examined at pH 3 so as to avoid the hydrolysis of Al(3+). The interaction between Al(3+) and AA was weak. However, the interaction between Al(3+) and PAA was strong and depended on the initial (COOH in PAA)/Al molar ratio (R(P)) of the solution. For the range of 1/R(P), the interaction between Al(3+) and PAA can be divided into three categories: (1) 1:1 Al-PAA-complex (an Al(3+) combines to a carboxyl group), (2) intermolecular Al-PAA-complex (an Al(3+) combines to more than 2 carboxyl groups of other Al-PAA-complexes) in addition to the 1:1 Al-PAA-complex and (3) precipitation of intermolecular complexes. In conclusion, R(P) is an important factor affecting the behavior of Al(3+) in acidic soil solution.

  11. Modeling Human Exposure Levels to Airborne Volatile Organic Compounds by the Hebei Spirit Oil Spill

    OpenAIRE

    Kim, Jong Ho; Kwak, Byoung Kyu; Ha, Mina; Cheong, Hae-Kwan; Yi, Jongheop

    2012-01-01

    Objectives The goal was to model and quantify the atmospheric concentrations of volatile organic compounds (VOCs) as the result of the Hebei Spirit oil spill, and to predict whether the exposure levels were abnormally high or not. Methods We developed a model for calculating the airborne concentration of VOCs that are produced in an oil spill accident. The model was applied to a practical situation, namely the Hebei Spirit oil spill. The accuracy of the model was verified by comparing the res...

  12. Amino Acid Profile and Volatile Flavour Compounds of Raw and Steamed Patin Catfish (Pangasius hypophthalmus) and Narrow-barred Spanish Mackerel (Scomberomorus commerson)

    Science.gov (United States)

    Pratama, Rusky I.; Rostini, I.; Rochima, E.

    2018-02-01

    Fish species and processing methods could affect the volatile flavour composition and amino acid profile of fishery commodity. The objectives of this study were to identify volatile components and amino acid profile of two considered predominant fish species in Indonesia which are freshwater Patin catfish (Pangasius hypophthalmus) and marine water fish, Spanish mackerel (Scomberomorus commerson). The methods used in this study were to detect volatile compounds using Gas Chromatography/Mass Spectrometry (GC/MS) on fresh and steamed of both species samples (100°C for 30 minutes) and amino acid profile were also analyzed using High Performance Liquid Chromatography (HPLC). The volatile components analysis successfully detects as much as 29 and 59 volatiles compounds in fresh and steamed Patin catfish respectively, while 37 and 102 compounds were detected in fresh and steamed Spanish mackerel samples. Most of detected components derives from hydrocarbons, aldehydes, alcohols and ketone groups which could affected by their chemical composition and resulted from various thermal involved reaction. The amino acids profile identification results showed that glutamic acid was found higher compared to other amino acids standards in both samples. Glutamic acid is non-essential amino acid which is important in umami taste substances.

  13. Electrochemical and spectroscopic studies of the complexed species of models of nitrohumic acids derived from phthalic acid

    Directory of Open Access Journals (Sweden)

    Mercê Ana Lucia Ramalho

    1998-01-01

    Full Text Available The study of model compounds is necessary in order to obtain information about complex organic substances as in the case of humic substances (HS. These substances are potential organic fertilizers and have other important functions in soils, natural waters and organic sediments. The main chemical properties of the complexes formed from 3-nitrophthalic and 4-nitrophthalic acids and the metal ions Fe(III and Zn(II were studied using potentiometric titrations, ultraviolet-visible spectroscopy (UV-Vis and cyclic voltammetry (CV. A trial potentiometric titration was done with a mixture of the models for nitrohumic acids and Cu(II. Equilibrium constants for the systems were calculated and UV-Vis and CV were employed to monitor the formation of the species. Comparative studies involving chelating centres of nitrosalicylic acids and nitrocatechols with Fe(III, Zn(II and Cu(II are presented. The initial studies involving the nitrohumic substances (NHS, a laboratory artifact of HS have been made and good evidence was found for the further use of NHS as a potential organic fertilizer as well as HS. In this present work one of the observed advantages of NHS over HS was that some aromatic nitro- centres can bind some metal ions at p[H] values of normal soils, near 7.0 to 7.5.

  14. Quantitative chromatography in the analysis of labelled compounds 1. Quantitative paper chromotography of amino acids by A spot comparison technique

    International Nuclear Information System (INIS)

    Barakat, M.F.; Farag, A.N.; El-Gharbawy, A.A.

    1974-01-01

    For the determination of the specific activity of labelled compounds separated by paper sheet chromatography, it was found essential to perfect the quantitative aspect of the paper chromatographic technique. Actually, so far paper chromatography has been used as a separation tool mainly and its use in quantification of the separated materials is by far less studied. In the present work, the quantitative analysis of amino acids by paper sheet chromatography has been carried out by methods, depending on the use of the relative spot area values for correcting the experimental data obtained. The results obtained were good and reproducible. The main advantage of the proposed technique is its extreme simplicity. No complicated equipment of procedures are necessary

  15. Influence of Iron on Production of the Antibacterial Compound Tropodithietic Acid and Its Noninhibitory Analog in Phaeobacter inhibens

    DEFF Research Database (Denmark)

    D'Alvise, Paul W; Phippen, Christopher B W; Nielsen, Kristian Fog

    2016-01-01

    production is influenced by substrate components. High concentrations of ferric citrate, as present in marine broth, or other iron sources were required for production of antibacterially active TDA. However, when supernatants of noninhibitory, low-iron cultures of Phaeobacter inhibens were acidified......Tropodithietic acid (TDA) is an antibacterial compound produced by some Phaeobacter and Ruegeria spp. of the Roseobacter clade. TDA production is studied in marine broth or agar since antibacterial activity in other media is not observed. The purpose of this study was to determine how TDA......, antibacterial activity was detected in a bioassay. The absence of TDA in nonacidified cultures and the presence of TDA in acidified cultures were verified by liquid chromatography-high-resolution mass spectrometry. A noninhibitory TDA analog (pre-TDA) was produced by P. inhibens, Ruegeria mobilis F1926...

  16. The Dangling model in the construction of compound sentences with regard to verb tenses

    Directory of Open Access Journals (Sweden)

    Mahmoud Mehravaran

    2016-02-01

    the mistakes of some of the grammars. This research project has for the first time introduced constructive models of compound sentences in a comprehensive research taking in to account the tense of the verbs. The primary question in this research project is which kind of sentences can be considered as compound and what is the constructive of such a sentence? When defining a compound sentences, grammarians either shave the same beliefs or differ in their ideas. But all grammarians agree to the fact that a compound sentences has more than one verb. Different definitions are due to different criteria adapted in constructing a compound sentences. To construct a noun, and adjective, a verb and a sentence we should take similar and precise criteria to our consideration. In the grammatical units of noun, adjectives, and verbs construction means connecting two or more parts that can convey one similar meaning and its parts are dependent upon one another.  In the construction of compound sentences there must be the same criteria so that its applications can be truly recognized and identified just like the previously mentioned grammatical units. The first step to arrive at a criterion in defining and identifying compound sentences, is to separate this discussion from connective sentences that are relate to each other with connectives are called connective sentences. But sentences which are constructed with dependent making connectives and their parts are dependent upon one another are called compound sentences. Therefore the signs of compound sentences with regard to constructions and the meaning of criterion are as follows: 1 They have more than one verb. 2 The consistence of two or more dependent phrases. 3 Phrases construct a complete sentences all together and convey one similar message. 4 One of the phrases is the main clause and the other one is the subordinate one. 5 The phrases or subordinate clauses can be related to one of the major parts and they can take a

  17. The Dangling model in the construction of compound sentences with regard to verb tenses

    Directory of Open Access Journals (Sweden)

    Mahmoud Mehravaran

    2016-01-01

    the mistakes of some of the grammars. This research project has for the first time introduced constructive models of compound sentences in a comprehensive research taking in to account the tense of the verbs. The primary question in this research project is which kind of sentences can be considered as compound and what is the constructive of such a sentence? When defining a compound sentences, grammarians either shave the same beliefs or differ in their ideas. But all grammarians agree to the fact that a compound sentences has more than one verb. Different definitions are due to different criteria adapted in constructing a compound sentences. To construct a noun, and adjective, a verb and a sentence we should take similar and precise criteria to our consideration. In the grammatical units of noun, adjectives, and verbs construction means connecting two or more parts that can convey one similar meaning and its parts are dependent upon one another.  In the construction of compound sentences there must be the same criteria so that its applications can be truly recognized and identified just like the previously mentioned grammatical units. The first step to arrive at a criterion in defining and identifying compound sentences, is to separate this discussion from connective sentences that are relate to each other with connectives are called connective sentences. But sentences which are constructed with dependent making connectives and their parts are dependent upon one another are called compound sentences. Therefore the signs of compound sentences with regard to constructions and the meaning of criterion are as follows: 1 They have more than one verb. 2 The consistence of two or more dependent phrases. 3 Phrases construct a complete sentences all together and convey one similar message. 4 One of the phrases is the main clause and the other one is the subordinate one. 5 The phrases or subordinate clauses can be related to one of the major parts and they can take a

  18. Studies of dissolution solutions of ruthenium metal, oxide and mixed compounds in nitric acid

    International Nuclear Information System (INIS)

    Mousset, F.; Eysseric, C.; Bedioui, F.

    2004-01-01

    Ruthenium is one of the fission products generated by irradiated nuclear fuel. It is present throughout all the steps of nuclear fuel reprocessing-particularly during extraction-and requires special attention due to its complex chemistry and high βγ activity. An innovative electro-volatilization process is now being developed to take advantage of the volatility of RuO 4 in order to eliminate it at the head end of the Purex process and thus reduce the number of extraction cycles. Although the process operates successfully with synthetic nitrato-RuNO 3+ solutions, difficulties have been encountered in extrapolating it to real-like dissolution solutions. In order to better approximate the chemical forms of ruthenium found in fuel dissolution solutions, kinetic and speciation studies on dissolved species were undertaken with RuO 2 ,xH 2 O and Ru 0 in nitric acid media. (authors)

  19. Development of antiproliferative nanohybrid compound with controlled release property using ellagic acid as the active agent

    Directory of Open Access Journals (Sweden)

    Hussein MZ

    2011-07-01

    Full Text Available Mohd Zobir Hussein1,2, Samer Hasan Al Ali2, Zulkarnain Zainal2, Muhammad Nazrul Hakim31Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA, 2Department of Chemistry, Faculty of Science, 3Department of Biomedical Science, Faculty of Medicine and Health Science, Universiti Putra Malaysia, Selangor, MalaysiaAbstract: An ellagic acid (EA–zinc layered hydroxide (ZLH nanohybrid (EAN was synthesized under a nonaqueous environment using EA and zinc oxide (ZnO as the precursors. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was 10.4 Å, resulting in the spatial orientation of EA molecules between the interlayers of 22.5° from z-axis with two negative charges at 8,8′ position of the molecules pointed toward the ZLH interlayers. FTIR study showed that the intercalated EA spectral feature is generally similar to that of EA, but with bands slightly shifted. This indicates that some chemical bonding of EA presence between the nanohybrid interlayers was slightly changed, due to the formation of host–guest interaction. The nanohybrid is of mesopores type with 58.8% drug loading and enhanced thermal stability. The release of the drug active, EA from the nanohybrid was found to be sustained and therefore has good potential to be used as a drug controlled-release formulation. In vitro bioassay study showed that the EAN has a mild effect on the hepatocytes cells, similar to its counterpart, free EA.Keywords: ellagic acid, nonaqueous solution, ZnO, zinc-layered hydroxide, viability test

  20. THE COORDINATION COMPOUNDS OF COBALT (II, III WITH DITHIOCARBAMIC ACID DERIVATIVES — MODIFICATORS OF HYDROLYTIC ENZYMES ACTIVITY

    Directory of Open Access Journals (Sweden)

    L. D. Varbanets

    2013-02-01

    Full Text Available Chloride, bromide and isothiocyanate complexes of cobalt(II with N-substituted thiocarbamoyl-N?-pentamethylenesulfenamides (1–(12, and also complexes of cobalt(II, Ш with derivatives of morpholine-4-carbodithioic acid (13–(18 have been used as modificators of enzymes of hydrolytic action — Bacillus thurin-giensis ІМВ В-7324 peptidases, Bacillus subtilis 147 and Aspergillus flavus var. oryzae 80428 amylases, Eupenicillium erubescens 248 and Cryptococcus albidus 1001 rhamnosidases. It was shown that cobalt (II, Ш compounds influence differently on the activity of enzymes tested, exerted both inhibitory and stimulatory action. It gives a possibility to expect that manifestation of activity by complex molecule depends on ligand and anion presence — Cl–, Br– or NCS–. The high activating action of cobalt(II complexes with N-substituted thiocarbamoyl-N?-pentamethylenesulphenamides (1–(12 on elastase and fibrinolytic activity of peptidases compared to tris(4-morpholinecarbodithioatocobalt(ІІІ (14 and products of its interaction with halogens (15–(17, causes inhibitory effect that is probably due to presence of a weekly S–N link, which is easy subjected to homolytic breaking. The studies of influences of cobalt(II complexes on activity of C. аlbidus and E. еrubescens ?-Lrhamnosidases showed, that majority of compounds inhibits of its activity, at that the most inhibitory effect exerts to C. аlbidus enzyme.To sum up, it is possible to state that character of influence of cobalt(II complexes with N-substituted thiocarbamoyl-N?-pentamethylenesulphenamides, and also cobalt(II, Ш complexes with derivatives of morpholine-4-carbodithioic acid varies depending on both strain producer and enzyme tested. The difference in complex effects on enzymes tested are due to peculiarities of building and functional groups of their active centers, which are also responsible for binding with modificators.

  1. Capillary microreactors for lactic acid extraction: experimental and modelling study

    NARCIS (Netherlands)

    Susanti, Susanti; Winkelman, Jozef; Schuur, Boelo; Heeres, Hero; Yue, Jun

    2015-01-01

    Lactic acid is an important biobased chemical and, among others, is used for the production of poly-lactic acid. Down-stream processing using state of the art technology is energy intensive and leads to the formation of large amounts of salts. In this presentation, experimental and modeling studies

  2. Modelling of thermal degradation kinetics of ascorbic acid in ...

    African Journals Online (AJOL)

    Ascorbic acid (vitamin C) loss in thermally treated pawpaw and potato was modelled mathematically. Isothermal experiments in the temperature range of 50 -80 oC for the drying of pawpaw and 60 -100 oC for the blanch-drying of potato were utilized to determine the kinetics of ascorbic acid loss in both fruit and vegetable.

  3. Reproducing the organic matter model of anthropogenic dark earth of Amazonia and testing the ecotoxicity of functionalized charcoal compounds

    Directory of Open Access Journals (Sweden)

    Carolina Rodrigues Linhares

    2012-05-01

    Full Text Available The objective of this work was to obtain organic compounds similar to the ones found in the organic matter of anthropogenic dark earth of Amazonia (ADE using a chemical functionalization procedure on activated charcoal, as well as to determine their ecotoxicity. Based on the study of the organic matter from ADE, an organic model was proposed and an attempt to reproduce it was described. Activated charcoal was oxidized with the use of sodium hypochlorite at different concentrations. Nuclear magnetic resonance was performed to verify if the spectra of the obtained products were similar to the ones of humic acids from ADE. The similarity between spectra indicated that the obtained products were polycondensed aromatic structures with carboxyl groups: a soil amendment that can contribute to soil fertility and to its sustainable use. An ecotoxicological test with Daphnia similis was performed on the more soluble fraction (fulvic acids of the produced soil amendment. Aryl chloride was formed during the synthesis of the organic compounds from activated charcoal functionalization and partially removed through a purification process. However, it is probable that some aryl chloride remained in the final product, since the ecotoxicological test indicated that the chemical functionalized soil amendment is moderately toxic.

  4. Degradation and mineralization of organic UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) using UV-254 nm/H{sub 2}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Abdelraheem, Wael H.M. [Chemistry Department, Faculty of Science, Sohag University, Sohag 82524 (Egypt); Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); He, Xuexiang; Duan, Xiaodi [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); NIREAS-International Water Research Center, University of Cyprus, Nicosia 1678 (Cyprus); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); NIREAS-International Water Research Center, University of Cyprus, Nicosia 1678 (Cyprus)

    2015-01-23

    Graphical abstract: - Highlights: • UV-254 nm/H{sub 2}O{sub 2} AOP was utilized for the degradation and mineralization of PBSA and BSA. • Promotion of k{sub obs} with [H{sub 2}O{sub 2}]{sub 0} ≤ 4 mM and inhibition at higher [H{sub 2}O{sub 2}]{sub 0} were observed. • The S and N were released and monitored as SO{sub 4}{sup 2−} and NH{sub 4}{sup +}, respectively. • Br{sup −} inhibited both the degradation and mineralization much more significantly than Cl{sup −}. • There was an increase in [NH{sub 4}{sup +}] at higher [H{sub 2}O{sub 2}]{sub 0} and its further destruction at higher UV fluence. - Abstract: Various studies have revealed the non-biodegradable and endocrine disrupting properties of sulfonated organic UV absorbers, directing people's attention toward their risks on ecological and human health and hence their removal from water. In this study, UV-254 nm/H{sub 2}O{sub 2} advanced oxidation process (AOP) was investigated for degrading a model UV absorber compound 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and a structurally similar compound 1H-benzimidazole-2-sulfonic acid (BSA), with a specific focus on their mineralization. At 4.0 mM [H{sub 2}O{sub 2}]{sub 0}, a complete removal of 40.0 μM parent PBSA and 25% decrease in TOC were achieved with 190 min of UV irradiation; SO{sub 4}{sup 2−} was formed and reached its maximum level while the release of nitrogen as NH{sub 4}{sup +} was much lower (around 50%) at 190 min. Sulfate removal was strongly enhanced by increasing [H{sub 2}O{sub 2}]{sub 0} in the range of 0–4.0 mM, with slight inhibition in 4.0–12.0 mM. Faster and earlier ammonia formation was observed at higher [H{sub 2}O{sub 2}]{sub 0}. The presence of Br{sup −} slowed down the degradation and mineralization of both compounds while a negligible effect on the degradation was observed in the presence of Cl{sup −}. Our study provides important technical and fundamental results on the HO{sup ·} based degradation and

  5. Functionalities of chitosan conjugated with stearic acid and gallic acid and application of the modified chitosan in stabilizing labile aroma compounds in an oil-in-water emulsion.

    Science.gov (United States)

    Yang, Tsung-Shi; Liu, Tai-Ti; Lin, I-Hwa

    2017-08-01

    The aims of this research were to conjugate chitosan (CT) with stearic acid (SA) and gallic acid (GA), and apply the modified chitosan to stabilize labile aroma compounds such as allyl isothiocyanate (AITC) and limonene in oil-in-water emulsions. Generally, the antioxidant activity of CT-SA-GA increased as the GA content in the conjugate increased. In most assays, GA had a lower IC 50 value than that of CT-SA-GA; however, CT-SA-GA exhibited better performance than GA in the Fe 2+ -chelating activity. In accelerated tests (heating or illumination) for evaluating the chemical stability of AITC and limonene during storage, CT-SA and CT-SA-GA were used to prepare AITC and limonene O/W emulsions, respectively. Tween 80 and Span 80 (T-S-80), an emulsifier mixture, were used as a control in both emulsions for comparison. The results show that CT-SA or CT-SA-GA could protect AITC or limonene from degradation or oxidation more effectively than T-S-80. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Kinetic and Isotherm Modelling of the Adsorption of Phenolic Compounds from Olive Mill Wastewater onto Activated Carbon

    Directory of Open Access Journals (Sweden)

    Alessandro A. Casazza

    2015-01-01

    Full Text Available The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL, the maximum sorption capacity of activated carbon expressed as mg of caff eic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to bett er describe the sorption system. The results confi rmed the effi ciency of activated carbon to remove almost all phenolic compound fractions from olive mill effl uent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.

  7. Determination of the n-octanol/water partition coefficients of weakly ionizable basic compounds by reversed-phase high-performance liquid chromatography with neutral model compounds.

    Science.gov (United States)

    Liang, Chao; Han, Shu-ying; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

    2014-11-01

    A strategy to utilize neutral model compounds for lipophilicity measurement of ionizable basic compounds by reversed-phase high-performance liquid chromatography is proposed in this paper. The applicability of the novel protocol was justified by theoretical derivation. Meanwhile, the linear relationships between logarithm of apparent n-octanol/water partition coefficients (logKow '') and logarithm of retention factors corresponding to the 100% aqueous fraction of mobile phase (logkw ) were established for a basic training set, a neutral training set and a mixed training set of these two. As proved in theory, the good linearity and external validation results indicated that the logKow ''-logkw relationships obtained from a neutral model training set were always reliable regardless of mobile phase pH. Afterwards, the above relationships were adopted to determine the logKow of harmaline, a weakly dissociable alkaloid. As far as we know, this is the first report on experimental logKow data for harmaline (logKow = 2.28 ± 0.08). Introducing neutral compounds into a basic model training set or using neutral model compounds alone is recommended to measure the lipophilicity of weakly ionizable basic compounds especially those with high hydrophobicity for the advantages of more suitable model compound choices and convenient mobile phase pH control. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Enhanced corrosion resistance of carbon steel in normal sulfuric acid medium by some macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety: AC impedance and computational studies

    International Nuclear Information System (INIS)

    Bentiss, F.; Lebrini, M.; Vezin, H.; Chai, F.; Traisnel, M.; Lagrene, M.

    2009-01-01

    We report here the use of macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety (n-MCTH) in the corrosion inhibition of C38 carbon steel in 0.5 M H 2 SO 4 acid medium. The aim of this work is devoted to study the inhibition characteristics of these compounds for acid corrosion of C38 steel using electrochemical impedance spectroscopy (EIS). Data obtained from EIS show a frequency distribution and therefore a modeling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution and the protection efficiency increased with increasing inhibitors concentration. The difference in their inhibitive action can be explained on the basis of the number of oxygen atoms present in the polyether ring which contribute to the chemisorption strength through the donor acceptor bond between the non bonding electron pair and the vacant orbital of metal surface. Adsorption of n-MCTH was found to follow the Langmuir's adsorption isotherm. The thermodynamic functions of adsorption process were calculated and the interpretation of the results is given. These results are complemented with quantum chemical study in order to provide an explanation of the differences between the probed inhibitors. Correlation between the inhibition efficiency and the structure of these compounds are presented.

  9. Retroconversion is a minor contributor to increases in eicosapentaenoic acid following docosahexaenoic acid feeding as determined by compound specific isotope analysis in rat liver.

    Science.gov (United States)

    Metherel, Adam H; Chouinard-Watkins, Raphaël; Trépanier, Marc-Olivier; Lacombe, R J Scott; Bazinet, Richard P

    2017-01-01

    Dietary docosahexaenoic acid (DHA, 22:6n-3) not only increases blood and tissue levels of DHA, but also eicosapentaenoic acid (EPA, 20:5n-3). It is generally believed that this increase is due to DHA retroconversion to EPA, however, a slower conversion of α-linolenic acid (ALA, 18:3n-3) derived EPA to downstream metabolic products (i.e. slower turnover of EPA) is equally plausible. In this study, 21-day old Long Evans rats were weaned onto an ALA only or DHA + ALA diet for 12 weeks. Afterwards, livers were collected and the natural abundance 13 C-enrichment was determined by compound specific isotope analysis (CSIA) of liver EPA by isotope ratio mass-spectrometry and compared to dietary ALA and DHA 13 C-enrichment. Isotopic signatures (per mil, ‰) for liver EPA were not different ( p  > 0.05) between the ALA only diet (-25.89 ± 0.39 ‰, mean ± SEM) and the DHA + ALA diet (-26.26 ± 0.40 ‰), suggesting the relative contribution from dietary ALA and DHA to liver EPA did not change. However, with DHA feeding estimates of absolute EPA contribution from ALA increased 4.4-fold (147 ± 22 to 788 ± 153 nmol/g) compared to 3.2-fold from DHA (91 ± 14 to 382 ± 13 nmol/g), respectively. In conclusion, CSIA of liver EPA in rats following 12-weeks of dietary DHA suggests that retroconversion of DHA to EPA is a relatively small contributor to increases in EPA, and that this increase in EPA is largely coming from elongation/desaturation of ALA.

  10. An elemental model of retrospective revaluation without within-compound associations.

    Science.gov (United States)

    Connor, Patrick C; Lolordo, Vincent M; Trappenberg, Thomas P

    2014-03-01

    When retrospective revaluation phenomena (e.g., unovershadowing: AB+, then A-, then test B) were discovered, simple elemental models were at a disadvantage because they could not explain such phenomena. Extensions of these models and novel models appealed to within-compound associations to accommodate these new data. Here, we present an elemental, neural network model of conditioning that explains retrospective revaluation apart from within-compound associations. In the model, previously paired stimuli (say, A and B, after AB+) come to activate similar ensembles of neurons, so that revaluation of one stimulus (A-) has the opposite effect on the other stimulus (B) through changes (decreases) in the strength of the inhibitory connections between neurons activated by B. The ventral striatum is discussed as a possible home for the structure and function of the present model.

  11. [Modeling of lactic acid fermentation of leguminous plant juices].

    Science.gov (United States)

    Shurkhno, R A; Validov, Sh Z; Boronin, A M; Naumova, R P

    2006-01-01

    Lactic acid fermentation of leguminous plant juices was modeled to provide a comparative efficiency assessment of the previously selected strains of lactic acid bacteria as potential components of starter cultures. Juices of the legumes fodder galega, red clover, and alfalfa were subjected to lactic acid fermentation in 27 variants of experiment. Local strains (Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, and Lactobacillus sp. RS 4) and the collection strain Lactobacillus plantarum BS 933 appeared the most efficient (with reference to the rate and degree of acidogenesis, ratio of lactic and acetic acids, and dynamics of microflora) in fermenting fodder galega juice; Lactobacillus sp. RS 1, Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, Lactobacillus sp. RS 4, and L. plantarum BS 933 were the most efficient for red clover juice. Correction of alfalfa juice fermentation using the tested lactic acid bacterial strains appeared inefficient, which is explainable by its increased protein content and a low level of the acids produced during fermentation.

  12. Rapid profiling of polymeric phenolic acids in Salvia miltiorrhiza by hybrid data-dependent/targeted multistage mass spectrometry acquisition based on expected compounds prediction and fragment ion searching.

    Science.gov (United States)

    Shen, Yao; Feng, Zijin; Yang, Min; Zhou, Zhe; Han, Sumei; Hou, Jinjun; Li, Zhenwei; Wu, Wanying; Guo, De-An

    2018-04-01

    Phenolic acids are the major water-soluble components in Salvia miltiorrhiza (>5%). According to previous studies, many of them contribute to the cardiovascular effects and antioxidant effects of S. miltiorrhiza. Polymeric phenolic acids can be considered as the tanshinol derived metabolites, e.g., dimmers, trimers, and tetramers. A strategy combined with tanshinol-based expected compounds prediction, total ion chromatogram filtering, fragment ion searching, and parent list-based multistage mass spectrometry acquisition by linear trap quadropole-orbitrap Velos mass spectrometry was proposed to rapid profile polymeric phenolic acids in S. miltiorrhiza. More than 480 potential polymeric phenolic acids could be screened out by this strategy. Based on the fragment information obtained by parent list-activated data dependent multistage mass spectrometry acquisition, 190 polymeric phenolic acids were characterized by comparing their mass information with literature data, and 18 of them were firstly detected from S. miltiorrhiza. Seven potential compounds were tentatively characterized as new polymeric phenolic acids from S. miltiorrhiza. This strategy facilitates identification of polymeric phenolic acids in complex matrix with both selectivity and sensitivity, which could be expanded for rapid discovery and identification of compounds from complex matrix. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A compound memristive synapse model for statistical learning through STDP in spiking neural networks

    Directory of Open Access Journals (Sweden)

    Johannes eBill

    2014-12-01

    Full Text Available Memristors have recently emerged as promising circuit elements to mimic the function of biological synapses in neuromorphic computing. The fabrication of reliable nanoscale memristive synapses, that feature continuous conductance changes based on the timing of pre- and postsynaptic spikes, has however turned out to be challenging. In this article, we propose an alternative approach, the compound memristive synapse, that circumvents this problem by the use of memristors with binary memristive states. A compound memristive synapse employs multiple bistable memristors in parallel to jointly form one synapse, thereby providing a spectrum of synaptic efficacies. We investigate the computational implications of synaptic plasticity in the compound synapse by integrating the recently observed phenomenon of stochastic filament formation into an abstract model of stochastic switching. Using this abstract model, we first show how standard pulsing schemes give rise to spike-timing dependent plasticity (STDP with a stabilizing weight dependence in compound synapses. In a next step, we study unsupervised learning with compound synapses in networks of spiking neurons organized in a winner-take-all architecture. Our theoretical analysis reveals that compound-synapse STDP implements generalized Expectation-Maximization in the spiking network. Specifically, the emergent synapse configuration represents the most salient features of the input distribution in a Mixture-of-Gaussians generative model. Furthermore, the network’s spike response to spiking input streams approximates a well-defined Bayesian posterior distribution. We show in computer simulations how such networks learn to represent high-dimensional distributions over images of handwritten digits with high fidelity even in presence of substantial device variations and under severe noise conditions. Therefore, the compound memristive synapse may provide a synaptic design principle for future neuromorphic

  14. A compound memristive synapse model for statistical learning through STDP in spiking neural networks.

    Science.gov (United States)

    Bill, Johannes; Legenstein, Robert

    2014-01-01

    Memristors have recently emerged as promising circuit elements to mimic the function of biological synapses in neuromorphic computing. The fabrication of reliable nanoscale memristive synapses, that feature continuous conductance changes based on the timing of pre- and postsynaptic spikes, has however turned out to be challenging. In this article, we propose an alternative approach, the compound memristive synapse, that circumvents this problem by the use of memristors with binary memristive states. A compound memristive synapse employs multiple bistable memristors in parallel to jointly form one synapse, thereby providing a spectrum of synaptic efficacies. We investigate the computational implications of synaptic plasticity in the compound synapse by integrating the recently observed phenomenon of stochastic filament formation into an abstract model of stochastic switching. Using this abstract model, we first show how standard pulsing schemes give rise to spike-timing dependent plasticity (STDP) with a stabilizing weight dependence in compound synapses. In a next step, we study unsupervised learning with compound synapses in networks of spiking neurons organized in a winner-take-all architecture. Our theoretical analysis reveals that compound-synapse STDP implements generalized Expectation-Maximization in the spiking network. Specifically, the emergent synapse configuration represents the most salient features of the input distribution in a Mixture-of-Gaussians generative model. Furthermore, the network's spike response to spiking input streams approximates a well-defined Bayesian posterior distribution. We show in computer simulations how such networks learn to represent high-dimensional distributions over images of handwritten digits with high fidelity even in presence of substantial device variations and under severe noise conditions. Therefore, the compound memristive synapse may provide a synaptic design principle for future neuromorphic architectures.

  15. Modeling of iodine radiation chemistry in the presence of organic compounds

    International Nuclear Information System (INIS)

    Taghipour, Fariborz; Evans, Greg J.

    2002-01-01

    A kinetic-based model was developed that simulates the radiation chemistry of iodine in the presence of organic compounds. The model's mechanistic description of iodine chemistry and generic semi-mechanistic reactions for various classes of organics, provided a reasonable representation of experimental results. The majority of the model and experimental results of iodine volatilization rates were in agreement within an order of magnitude

  16. Production of fermentation aroma compounds by Saccharomyces cerevisiae wine yeasts: effects of yeast assimilable nitrogen on two model strains.

    Science.gov (United States)

    Carrau, Francisco M; Medina, Karina; Farina, Laura; Boido, Eduardo; Henschke, Paul A; Dellacassa, Eduardo

    2008-11-01

    The contribution of yeast fermentation metabolites to the aromatic profile of wine is well documented; however, the biotechnological application of this knowledge, apart from strain selection, is still rather limited and often contradictory. Understanding and modeling the relationship between nutrient availability and the production of desirable aroma compounds by different strains must be one of the main objectives in the selection of industrial yeasts for the beverage and food industry. In order to overcome the variability in the composition of grape juices, we have used a chemically defined model medium for studying yeast physiological behavior and metabolite production in response to nitrogen supplementation so as to identify an appropriate yeast assimilable nitrogen level for strain differentiation. At low initial nitrogen concentrations, strain KU1 produced higher quantities of esters and fatty acids whereas M522 produced higher concentrations of isoacids, gamma-butyrolactone, higher alcohols and 3-methylthio-1-propanol. We propose that although strains KU1 and M522 have a similar nitrogen consumption profile, they represent useful models for the chemical characterization of wine strains in relation to wine quality. The differential production of aroma compounds by the two strains is discussed in relation to their capacity for nitrogen usage and their impact on winemaking. The results obtained here will help to develop targeted metabolic footprinting methods for the discrimination of industrial yeasts.

  17. Enantioselective Synthesis of α-Mercapto-β-amino Esters via Rh(II)/Chiral Phosphoric Acid-Cocatalyzed Three-Component Reaction of Diazo Compounds, Thiols, and Imines.

    Science.gov (United States)

    Xiao, Guolan; Ma, Chaoqun; Xing, Dong; Hu, Wenhao

    2016-12-02

    An enantioselective method for the synthesis of α-mercapto-β-amino esters has been developed via a rhodium(II)/chiral phosphoric acid-cocatalyzed three-component reaction of diazo compounds, thiols, and imines. This transformation is proposed to proceed through enantioselective trapping of the sulfonium ylide intermediate generated in situ from the diazo compound and thiol by the phosphoric acid-activated imine. With this method, a series of α-mercapto-β-amino esters were obtained in good yields with moderate to good stereoselectivities.

  18. Effect of different compound feeds on the fatty acid composition and other quality indicators in the meat of Lithuanian black-and-white bulls

    OpenAIRE

    Baltrukonienė, Gintarė

    2015-01-01

    Aim and objectives – To evaluate the effect of compound feed on the milk and dairy Black-and white bulls grawing and beef quality, fatty acids composition in the meat and liver, to evaluate meat sensory and textere characteristics. Objectives of the study: 1. to analyze the chemical composition of rapeseed, linseed and sunflower cakes and accordingly that of compound feeds and to determine the content and ratio of fatty acids; 2. to evaluate the growth rate of bulls and carry out contro...

  19. Shyntesis and cytotoxicity evaluation in vitro of new compounds with hybrid structures of 8-flavoneacetic acid and quinolones; Sintesis y evaluacion citotoxica in vitro de nuevos compuestos con estructuras hibridas del acido 8-flavonacetico quinolonas

    Energy Technology Data Exchange (ETDEWEB)

    Biaa, M F; Castellano, J M; Emling, F; Schlick, E [Knoll, S.a., Madrid (Spain)

    1994-12-31

    Using the structural similarity between 8-flavoneacetic acid the antitumor quinolones, we have prepared some hybrid compounds on both systems and studied their cytotoxicity. None of the sinthesized compounds have shown sufficient interest for further development. 33 refs.

  20. Effect of maceration duration on physicochemical characteristics, organic acid, phenolic compounds and antioxidant activity of red wine from Vitis vinifera L. Karaoglan.

    Science.gov (United States)

    Kocabey, N; Yilmaztekin, M; Hayaloglu, A A

    2016-09-01

    Effects of different maceration times (5, 10 and 15 days) on composition, phenolic compounds and antioxidant activities of red wines made from the Vitis vinifera L. Karaoglan grown in Malatya were investigated. Maceration duration changed some chemical constituents and color of Karaoglan red wines. A linear relationship was observed between antioxidant activity of wine and maceration duration. Major organic acid was tartaric acid which was at the highest concentration in wine macerated for 10 days. A total of 25 phenolic compounds was determined in wine samples. Within these phenolics; procyanidin B2, trans -caftaric acid, gallic acid, trans -caffeic acid, (+) catechin, (-) epicatechin and quercetin-3- O -glucoside were the most abundant phenolics regardless of maceration duration. In general, extended maceration duration resulted in increase in the concentration of phenolic compounds, reflecting the antioxidant activities of wine. In conclusion, the highest concentrations of total and individual phenolic compounds as well as antioxidant activities were found in wines macerated for 15 days.

  1. The thermodynamic stability of hydrogen bonded and cation bridged complexes of humic acid models-A theoretical study

    International Nuclear Information System (INIS)

    Aquino, Adelia J.A.; Tunega, Daniel; Pasalic, Hasan; Haberhauer, Georg; Gerzabek, Martin H.; Lischka, Hans

    2008-01-01

    Hydrogen bonded and cation bridged complexation of poly(acrylic acid) oligomers, representing a model compound for humic acids, with acetic acid and the herbicide (4-chloro-2-methylphenoxy) acetic acid (MCPA) have been studied by means of density functional theory. Solvation effects were computed by means of a combination of microsolvation (explicit insertion of water molecules) and global solvation (polarizable continuum approach). The stability of hydrogen bonded complexes in solution is characterized by a strong competition between solute and solvent molecules. The cation bridged complexes of the negatively charged (deprotonated) ligands were found to be strongly favored explaining the capability of humic acids to fixate anionic species from soil solutions and the ability to form cross-linking structures within the humic acid macromolecules

  2. Publicly available models to predict normal boiling point of organic compounds

    International Nuclear Information System (INIS)

    Oprisiu, Ioana; Marcou, Gilles; Horvath, Dragos; Brunel, Damien Bernard; Rivollet, Fabien; Varnek, Alexandre

    2013-01-01

    Quantitative structure–property models to predict the normal boiling point (T b ) of organic compounds were developed using non-linear ASNNs (associative neural networks) as well as multiple linear regression – ISIDA-MLR and SQS (stochastic QSAR sampler). Models were built on a diverse set of 2098 organic compounds with T b varying in the range of 185–491 K. In ISIDA-MLR and ASNN calculations, fragment descriptors were used, whereas fragment, FPTs (fuzzy pharmacophore triplets), and ChemAxon descriptors were employed in SQS models. Prediction quality of the models has been assessed in 5-fold cross validation. Obtained models were implemented in the on-line ISIDA predictor at (http://infochim.u-strasbg.fr/webserv/VSEngine.html)

  3. Phase equilibrium modelling for mixtures with acetic acid using an association equation of state

    DEFF Research Database (Denmark)

    Muro Sunè, Nuria; Kontogeorgis, Georgios; von Solms, Nicolas

    2008-01-01

    Acetic acid is a very important compound in the chemical industry with applications both as solvent and intermediate in the production of, e.g., polyesters. The design of these processes requires knowledge of the phase equilibria of mixtures containing acetic acid and a wide variety of compounds ...

  4. Inferring Phytoplankton, Terrestrial Plant and Bacteria Bulk δ¹³C Values from Compound Specific Analyses of Lipids and Fatty Acids

    Science.gov (United States)

    Taipale, Sami J.; Peltomaa, Elina; Hiltunen, Minna; Jones, Roger I.; Hahn, Martin W.; Biasi, Christina; Brett, Michael T.

    2015-01-01

    Stable isotope mixing models in aquatic ecology require δ13C values for food web end members such as phytoplankton and bacteria, however it is rarely possible to measure these directly. Hence there is a critical need for improved methods for estimating the δ13C ratios of phytoplankton, bacteria and terrestrial detritus from within mixed seston. We determined the δ13C values of lipids, phospholipids and biomarker fatty acids and used these to calculate isotopic differences compared to the whole-cell δ13C values for eight phytoplankton classes, five bacterial taxa, and three types of terrestrial organic matter (two trees and one grass). The lipid content was higher amongst the phytoplankton (9.5±4.0%) than bacteria (7.3±0.8%) or terrestrial matter (3.9±1.7%). Our measurements revealed that the δ13C values of lipids followed phylogenetic classification among phytoplankton (78.2% of variance was explained by class), bacteria and terrestrial matter, and there was a strong correlation between the δ13C values of total lipids, phospholipids and individual fatty acids. Amongst the phytoplankton, the isotopic difference between biomarker fatty acids and bulk biomass averaged -10.7±1.1‰ for Chlorophyceae and Cyanophyceae, and -6.1±1.7‰ for Cryptophyceae, Chrysophyceae and Diatomophyceae. For heterotrophic bacteria and for type I and type II methane-oxidizing bacteria our results showed a -1.3±1.3‰, -8.0±4.4‰, and -3.4±1.4‰ δ13C difference, respectively, between biomarker fatty acids and bulk biomass. For terrestrial matter the isotopic difference averaged -6.6±1.2‰. Based on these results, the δ13C values of total lipids and biomarker fatty acids can be used to determine the δ13C values of bulk phytoplankton, bacteria or terrestrial matter with ± 1.4‰ uncertainty (i.e., the pooled SD of the isotopic difference for all samples). We conclude that when compound-specific stable isotope analyses become more widely available, the determination of

  5. High-Throughput Screening of Chemical Compound Libraries for Modulators of Salicylic Acid Signaling by In Situ Monitoring of Glucuronidase-Based Reporter Gene Expression.

    Science.gov (United States)

    Halder, Vivek; Kombrink, Erich

    2018-01-01

    Salicylic acid (SA) is a vital phytohormone that is intimately involved in coordination of the complex plant defense response to pathogen attack. Many aspects of SA signaling have been unraveled by classical genetic and biochemical methods using the model plant Arabidopsis thaliana, but many details remain unknown, owing to the inherent limitations of these methods. In recent years, chemical genetics has emerged as an alternative scientific strategy to complement classical genetics by virtue of identifying bioactive chemicals or probes that act selectively on their protein targets causing either activation or inhibition. Such selective tools have the potential to create conditional and reversible chemical mutant phenotypes that may be combined with genetic mutants. Here, we describe a facile chemical screening methodology for intact Arabidopsis seedlings harboring the β-glucuronidase (GUS) reporter by directly quantifying GUS activity in situ with 4-methylumbelliferyl-β-D-glucuronide (4-MUG) as substrate. The quantitative nature of this screening assay has an obvious advantage over the also convenient histochemical GUS staining method, as it allows application of statistical procedures and unbiased hit selection based on threshold values as well as distinction between compounds with strong or weak bioactivity. We show pilot screens for chemical activators or inhibitors of salicylic acid-mediated defense signaling using the Arabidopsis line expressing the SA-inducible PR1p::GUS reporter gene. Importantly, the screening methodology provided here can be adopted for any inducible GUS reporter line.

  6. Effects of membrane composition on release of model hydrophilic compound from osmotic delivery systems.

    Science.gov (United States)

    Ozdemir, N; Ozalp, Y; Ozkan, Y

    2000-01-01

    In this study, the effects of surface-active agents in different types and concentrations, added into the coating solution, on release of model hydrophilic compound have been examined. For this purpose, the tablets, prepared with the use of methylene blue as a model substance, were coated by spray coating technique with cellulose acetate solution containing polyethylene glycol 400 as a plasticizer. In addition, cetylpyridinium chloride as cationic surface-active agent and sodium lauryl sulphate as anionic surface-active agent were added into coating solution in different concentrations. After creating a delivery orifice by a microdrill on the tablets, release of model hydrophilic compound was tested by the USP paddle method. The data obtained were evaluated according to the different kinetics and the mechanism of release from the preparations was examined. The surface properties of the coating material were investigated by scanning electron microscope taken before and after the contact with medium fluid, as well as the mechanical properties by tensile tests. In conclusion, it has been found that the cationic surface active agent, cetylpyridinium chloride reduced the lag time, observed during the release of model hydrophilic compound, as a result of its enhancing effect on wettability of tablets by reducing the contact angle between the medium fluid and the coating material. On the other hand, the anionic surface active agent, sodium lauryl sulphate has been inactivated possibly due to the interaction with model hydrophilic compound that has cationic properties and/or substances contained in membrane composition; thus, the lag time has not decreased and furthermore, a significant decrease in the delivery rate of model hydrophilic compound has been observed.

  7. Utilization of biomass: Conversion of model compounds to hydrocarbons over zeolite H-ZSM-5

    DEFF Research Database (Denmark)

    Mentzel, Uffe Vie; Holm, Martin Spangsberg

    2011-01-01

    Zeolite catalyzed deoxygenation of small oxygenates present in bio-oil or selected as model compounds was performed under Methanol-to-Hydrocarbons (MTH) like reaction conditions using H-ZSM-5 as the catalyst. Co-feeding of the oxygenates with methanol generally decreases catalyst lifetime due...

  8. Absorption tuning of the green fluorescent protein chromophore: synthesis and studies of model compounds

    DEFF Research Database (Denmark)

    Brøndsted Nielsen, Mogens; Andersen, Lars Henrik; Rinza, Tomás Rocha

    2011-01-01

    The green fluorescent protein (GFP) chromophore is a heterocyclic compound containing a p-hydroxybenzylidine attached to an imidazol-5(4H)-one ring. This review covers the synthesis of a variety of model systems for elucidating the intrinsic optical properties of the chromophore in the gas phase ...

  9. Equation of state for neutron matter in the Quark Compound Bag model

    Science.gov (United States)

    Krivoruchenko, M. I.

    2017-11-01

    The equation of state for neutron matter is derived in the framework of the Quark Compound Bag model, in which the nucleon-nucleon interaction is generated by the s-channel exchange of six-quark Jaffe-Low primitives.

  10. Compound waves in a higher order nonlinear model of thermoviscous fluids

    DEFF Research Database (Denmark)

    Rønne Rasmussen, Anders; Sørensen, Mads Peter; Gaididei, Yuri B.

    2016-01-01

    A generalized traveling wave ansatz is used to investigate compound shock waves in a higher order nonlinear model of a thermoviscous fluid. The fluid velocity potential is written as a traveling wave plus a linear function of space and time. The latter offers the possibility of predicting...

  11. The Action of Chain Extenders in Nylon-6, PET, and Model Compounds

    NARCIS (Netherlands)

    Loontjens, T.; Pauwels, K.; Derks, F.; Neilen, M.; Sham, C.K.; Serné, M.

    1997-01-01

    The action of two complementary chain extenders is studied in model systems as well as in poly(ethylene terephthalate) (PET) and nylon–6. Chain extenders are low molecular weight compounds that can be used to increase the molecular weight of polymers in a short time. The reaction must preferably be

  12. Hazard rate model and statistical analysis of a compound point process

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr

    2005-01-01

    Roč. 41, č. 6 (2005), s. 773-786 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GA402/04/1294 Institutional research plan: CEZ:AV0Z10750506 Keywords : couting process * compound process * Cox regression model * intensity Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.343, year: 2005

  13. Computational results on the compound binomial risk model with nonhomogeneous claim occurrences

    NARCIS (Netherlands)

    Tuncel, A.; Tank, F.

    2013-01-01

    The aim of this paper is to give a recursive formula for non-ruin (survival) probability when the claim occurrences are nonhomogeneous in the compound binomial risk model. We give recursive formulas for non-ruin (survival) probability and for distribution of the total number of claims under the

  14. Using Molecular Modeling in Teaching Group Theory Analysis of the Infrared Spectra of Organometallic Compounds

    Science.gov (United States)

    Wang, Lihua

    2012-01-01

    A new method is introduced for teaching group theory analysis of the infrared spectra of organometallic compounds using molecular modeling. The main focus of this method is to enhance student understanding of the symmetry properties of vibrational modes and of the group theory analysis of infrared (IR) spectra by using visual aids provided by…

  15. Fermentative activity and production of volatile compounds by Saccharomyces grown in synthetic grape juice media deficient in assimilable nitrogen and/or pantothenic acid.

    Science.gov (United States)

    Wang, X D; Bohlscheid, J C; Edwards, C G

    2003-01-01

    To understand the impact of assimilable nitrogen and pantothenic acid on fermentation rate and synthesis of volatile compounds by Saccharomyces under fermentative conditions. A 2 x 3 factorial experimental design was employed with the concentrations of yeast assimilable nitrogen (YAN) (60 and 250 mg l(-1)) and pantothenic acid (10, 50 and 250 microg l(-1)) as variables. In media containing 250 microg l(-1) pantothenic acid, H2S production by two different species of Saccharomyces decreased when YAN was increased from 60 to 250 mg l(-1). Conversely, H2S production was significantly higher when the concentration of assimilable nitrogen was increased if pantothenic acid was deficient (10 or 50 microg l(-1)). Yeast synthesis of other volatile compounds were impacted by both assimilable nitrogen and pantothenic acid. While growth and fermentative rate of Saccharomyces was more influenced by nitrogen than by pantothenic acid, complicated interactions exist between these nutrients that affect the synthesis of volatile compounds including H2S. This study has important implications for the winemaking industry where a better understanding of the nutritional requirements of Saccharomyces is necessary to reduce fermentation problems and to improve final product quality.

  16. Kinetic analysis of polyoxometalate (POM) oxidation of non-phenolic lignin model compound

    Science.gov (United States)

    Tomoya Yokoyama; Hou-min Chang; Ira A. Weinstock; Richard S. Reiner; John F. Kadla

    2003-01-01

    Kinetic and reaction mechanism of non-phenolic lignin model compounds under anaerobic polyoxometalate (POM), Na5(+1.9)[SiV1(-0.1)MoW10(+0.1) 40], bleaching conditions were examined. Analyses using a syringyl type model, 1-(3,4,5-trimethoxyphenyl)ethanol (1), a guaiacyl type, 1-(3,4- imethoxyphenyl)ethanol (2), and 1- (4-ethoxy-3,5-dimethoxyphenyl)ethanol (3) suggest...

  17. Stochastic Interest Model Based on Compound Poisson Process and Applications in Actuarial Science

    OpenAIRE

    Li, Shilong; Yin, Chuancun; Zhao, Xia; Dai, Hongshuai

    2017-01-01

    Considering stochastic behavior of interest rates in financial market, we construct a new class of interest models based on compound Poisson process. Different from the references, this paper describes the randomness of interest rates by modeling the force of interest with Poisson random jumps directly. To solve the problem in calculation of accumulated interest force function, one important integral technique is employed. And a conception called the critical value is introduced to investigat...

  18. Interpreting expression data with metabolic flux models: predicting Mycobacterium tuberculosis mycolic acid production.

    Directory of Open Access Journals (Sweden)

    Caroline Colijn

    2009-08-01

    Full Text Available Metabolism is central to cell physiology, and metabolic disturbances play a role in numerous disease states. Despite its importance, the ability to study metabolism at a global scale using genomic technologies is limited. In principle, complete genome sequences describe the range of metabolic reactions that are possible for an organism, but cannot quantitatively describe the behaviour of these reactions. We present a novel method for modeling metabolic states using whole cell measurements of gene expression. Our method, which we call E-Flux (as a combination of flux and expression, extends the technique of Flux Balance Analysis by modeling maximum flux constraints as a function of measured gene expression. In contrast to previous methods for metabolically interpreting gene expression data, E-Flux utilizes a model of the underlying metabolic network to directly predict changes in metabolic flux capacity. We applied E-Flux to Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB. Key components of mycobacterial cell walls are mycolic acids which are targets for several first-line TB drugs. We used E-Flux to predict the impact of 75 different drugs, drug combinations, and nutrient conditions on mycolic acid biosynthesis capacity in M. tuberculosis, using a public compendium of over 400 expression arrays. We tested our method using a model of mycolic acid biosynthesis as well as on a genome-scale model of M. tuberculosis metabolism. Our method correctly predicts seven of the eight known fatty acid inhibitors in this compendium and makes accurate predictions regarding the specificity of these compounds for fatty acid biosynthesis. Our method also predicts a number of additional potential modulators of TB mycolic acid biosynthesis. E-Flux thus provides a promising new approach for algorithmically predicting metabolic state from gene expression data.

  19. Preparation of an aminopropyl imidazole-modified silica gel as a sorbent for solid-phase extraction of carboxylic acid compounds and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Na; Guo, Yong; Wang, Licheng; Liang, Xiaojing; Liu, Shujuan; Jiang, Shengxiang

    2014-05-21

    In this paper, a kind of aminopropyl imidazole-modified silica sorbent was synthesized and used as a solid-phase extraction (SPE) sorbent for the determination of carboxylic acid compounds and polycyclic aromatic hydrocarbons (PAHs). The resultant aminopropyl imidazole-modified silica sorbent was characterized by Fourier transform infrared spectroscopy (FT-IR) and elemental analysis (EA) to ensure the successful binding of aminopropyl imidazole on the surface of silica gel. Then the aminopropyl imidazole-modified silica sorbent served as a SPE sorbent for the enrichment of carboxylic acid compounds and PAHs. The new sorbent exhibited high extraction efficiency towards the tested compounds and the results show that such a sorbent can offer multiple intermolecular interactions: electrostatic, π-π, and hydrophobic interactions. Several parameters affecting the extraction recovery, such as the pH of sample solution, the pH of eluent, the solubility of eluent, the volume of eluent, and sample loading, were also investigated. Under the optimized conditions, the proposed method was applied to the analysis of four carboxylic acid compounds and four PAHs in environmental water samples. Good linearities were obtained for all the tested compounds with R(2) larger than 0.9903. The limits of detection were found to be in the range of 0.0065-0.5 μg L(-1). The recovery values of spiked river water samples were from 63.2% to 112.3% with relative standard deviations (RSDs) less than 10.1% (n = 4).

  20. The MCRA model for probabilistic single-compound and cumulative risk assessment of pesticides.

    Science.gov (United States)

    van der Voet, Hilko; de Boer, Waldo J; Kruisselbrink, Johannes W; Goedhart, Paul W; van der Heijden, Gerie W A M; Kennedy, Marc C; Boon, Polly E; van Klaveren, Jacob D

    2015-05-01

    Pesticide risk assessment is hampered by worst-case assumptions leading to overly pessimistic assessments. On the other hand, cumulative health effects of similar pesticides are often not taken into account. This paper describes models and a web-based software system developed in the European research project ACROPOLIS. The models are appropriate for both acute and chronic exposure assessments of single compounds and of multiple compounds in cumulative assessment groups. The software system MCRA (Monte Carlo Risk Assessment) is available for stakeholders in pesticide risk assessment at mcra.rivm.nl. We describe the MCRA implementation of the methods as advised in the 2012 EFSA Guidance on probabilistic modelling, as well as more refined methods developed in the ACROPOLIS project. The emphasis is on cumulative assessments. Two approaches, sample-based and compound-based, are contrasted. It is shown that additional data on agricultural use of pesticides may give more realistic risk assessments. Examples are given of model and software validation of acute and chronic assessments, using both simulated data and comparisons against the previous release of MCRA and against the standard software DEEM-FCID used by the Environmental Protection Agency in the USA. It is shown that the EFSA Guidance pessimistic model may not always give an appropriate modelling of exposure. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  1. Uniform angular overlap model interpretation of the crystal field effect in U(5+) fluoride compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, Z.; Mulak, J. (W. Trzebiatowski Inst. of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw (Poland))

    1990-11-01

    The uniform interpretation of the crystal field effect in three different U(5+) fluoride compounds: CsUF{sub 6}, {alpha}-UF{sub 5} and {beta}-UF{sub 5} within the angular overlap model (AOM) is given. Some characteristic relations between the AOM parameters and their distance dependencies resulting from ab initio calculations are introduced and examined from a phenomenological point of view. The traditional simplest approach with only one independent parameter, i.e. e{sub {sigma}} with e{sub {pi}}:e{sub {sigma}} = 0.32 and e{sub {delta}} = 0, is shown to provide a consistent interpretation of the crystal field effect of the whole class of the compounds. The parameters obtained for one compound are easily and successfully extrapolated to others. The specificity and importance of the e{sub {delta}} parameter for 5f{sup 1} systems is discussed. (orig.).

  2. Effect of stevia and citric acid on the stability of phenolic compounds and in vitro antioxidant and antidiabetic capacity of a roselle (Hibiscus sabdariffa L.) beverage.

    Science.gov (United States)

    Pérez-Ramírez, Iza F; Castaño-Tostado, Eduardo; Ramírez-de León, José A; Rocha-Guzmán, Nuria E; Reynoso-Camacho, Rosalía

    2015-04-01

    Plant infusions are consumed due to their beneficial effects on health, which is attributed to their bioactive compounds content. However, these compounds are susceptible to degradation during processing and storage. The objective of this research was to evaluate the effect of stevia and citric acid on the stability of phenolic compounds, antioxidant capacity and carbohydrate-hydrolysing enzyme inhibitory activity of roselle beverages during storage. The optimum extraction conditions of roselle polyphenolic compounds was of 95 °C/60 min, which was obtained by a second order experimental design. The incorporation of stevia increased the stability of colour and some polyphenols, such as quercetin, gallic acid and rosmarinic acid, during storage. In addition, stevia decreased the loss of ABTS, DPPH scavenging activity and α-amylase inhibitory capacity, whereas the incorporation of citric acid showed no effect. These results may contribute to the improvement of technological processes for the elaboration of hypocaloric and functional beverages. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Effect of low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Lignos, G.D.; Bakker, R.R.C.; Koukios, E.G.

    2012-01-01

    The objective of this work was to investigate the feasibility of combining low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis for the high production of fermentable substrates and the low release of inhibitory compounds. For most of the pretreatments at 160

  4. The Impact of the Antimicrobial Compounds Produced by Lactic Acid Bacteria on the Growth Performance of Mycobacterium avium subsp. paratuberculosis

    Directory of Open Access Journals (Sweden)

    Petr Kralik

    2018-04-01

    Full Text Available Cell-free supernatants (CFSs extracted from various lactic acid bacteria (LAB cultures were applied to Mycobacterium avium subsp. paratuberculosis (MAP cells to determine their effect on MAP viability. In addition, 5% lactic acid (LA; pH 3 and commercially synthetized nisin bacteriocin were also tested. This procedure was chosen in order to mimic the influence of LAB compounds during the production and storage of fermented milk products, which can be contaminated by MAP. Its presence in milk and milk products is of public concern due to the possible ingestion of MAP by consumers and the discussed role of MAP in Crohn’s disease. Propidium monoazide real-time PCR (PMA qPCR was used for viability determination. Although all CFS showed significant effects on MAP viability, two distinct groups of CFS – effective and less effective – could be distinguished. The effective CFSs were extracted from various lactobacilli cultures, their pH values were mostly lower than 4.5, and their application resulted in >2 log10 reductions in MAP viability. The group of less effective CFS were filtered from Lactococcus and enterococci cultures, their pH values were higher than 4.5, and their effect on MAP viability was <2 log10. LA elicited a reduction in MAP viability that was similar to that of the group of less effective CFS. Almost no effect was found when using commercially synthetized nisin at concentrations of 0.1–1000 μg/ml. A combination of the influence of the type of bacteriocin, the length of its action, bacteriocin production strain, and pH are all probably required for a successful reduction in MAP viability. However, certain bacteriocins and their respective LAB strains (Lactobacillus sp. appear to play a greater role in reducing the viability of MAP than pH.

  5. Lifetime modelling of lead acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bindner, H.; Cronin, T.; Lundsager, P.

    2005-04-01

    The performance and lifetime of energy storage in batteries are an important part of many renewable based energy systems. Not only do batteries impact on the system performance but they are also a significant expenditure when considering the whole life cycle costs. Poor prediction of lifetime can, therefore, lead to uncertainty in the viability of the system in the long term. This report details the work undertaken to investigate and develop two different battery life prediction methodologies with specific reference to their use in hybrid renewable energy systems. Alongside this, results from battery tests designed to exercise batteries in similar modes to those that they experience in hybrid systems have also been analysed. These have yielded battery specific parameters for use in the prediction software and the first results in the validation process of the software are also given. This work has been part of the European Union Benchmarking research project (ENK6-CT-2001-80576), funded by the European Union, the United States and Australian governments together with other European states and other public and private financing bodies. The project has concentrated on lead acid batteries as this technology is the most commonly used. Through this work the project partner institutions have intended to provide useful tools to improve the design capabilities of organizations, private and public, in remote power systems. (au)

  6. Determination of Acid Dissociation Constants (pKa) of Bicyclic Thiohydantoin-Pyrrolidine Compounds in 20% Ethanol-Water Hydroorganic Solvent

    Science.gov (United States)

    Nural, Yahya; Döndaş, H. Ali; Sarı, Hayati; Atabey, Hasan; Belveren, Samet; Gemili, Müge

    2014-01-01

    The acid dissociation constants of potential bioactive fused ring thiohydantoin-pyrrolidine compounds were determined by potentiometric titration in 20% (v/v) ethanol-water mixed at 25 ± 0.1°C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Proton affinities of potential donor atoms of the ligands were calculated by AM1 and PM3 semiempiric methods. We found, potentiometrically, three different acid dissociation constants for 1a–f. We suggest that these acid dissociation constants are related to the carboxyl, enol, and amino groups. PMID:24799905

  7. Acid hydrolysis of corn stover using hydrochloric acid: Kinetic modeling and statistical optimization

    Directory of Open Access Journals (Sweden)

    Sun Yong

    2014-01-01

    Full Text Available The hydrolysis of corn stover using hydrochloric acid was studied. The kinetic parameters of the mathematical models for predicting the yields of xylose, glucose, furfural and acetic acid were obtained, and the corresponding xylose generation activation energy of 100 kJ/mol was determined. The characterization of corn stover using with different techniques during hydrolysis indicated an effective removal of xylan and the slightly alteration on the structures of cellulose and lignin. A 23five levels Central Composite Design (CCD was used to develop a statistical model for the optimization of process variables including acid concentration, pretreatment temperature and time. The optimum conditions determined by this model were found to be 108ºC for 80 minutes with acid concentration of 5.8%. Under these conditions, the maximised results are the following: xylose 19.93 g/L, glucose 1.2 g/L, furfural 1.5 g/L, acetic acid 1.3 g/L. The validation of the model indicates a good agreement between the experimental results and the predicted values.

  8. Key intermediates in nitrogen transformation during microwave pyrolysis of sewage sludge: a protein model compound study.

    Science.gov (United States)

    Zhang, Jun; Tian, Yu; Cui, Yanni; Zuo, Wei; Tan, Tao

    2013-03-01

    The nitrogen transformations with attention to NH3 and HCN were investigated at temperatures of 300-800°C during microwave pyrolysis of a protein model compound. The evolution of nitrogenated compounds in the char, tar and gas products were conducted. The amine-N, heterocyclic-N and nitrile-N compounds were identified as three important intermediates during the pyrolysis. NH3 and HCN were formed with comparable activation energies competed to consume the same reactive substances at temperatures of 300-800°C. The deamination and dehydrogenation of amine-N compounds from protein cracking contributed to the formation of NH3 (about 8.9% of Soy-N) and HCN (6.6%) from 300 to 500°C. The cracking of nitrile-N and heterocyclic-N compounds from the dehydrogenation and polymerization of amine-N generated HCN (13.4%) and NH3 (31.3%) between 500 and 800°C. It might be able to reduce the HCN and NH3 emissions through controlling the intermediates production at temperatures of 500-800°C. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Ab initio and kinetic modeling studies of formic acid oxidation

    DEFF Research Database (Denmark)

    Marshall, Paul; Glarborg, Peter

    2015-01-01

    A detailed chemical kinetic model for oxidation of formic acid (HOCHO) in flames has been developed, based on theoretical work and data from literature. Ab initio calculations were used to obtain rate coefficients for reactions of HOCHO with H, O, and HO2. Modeling predictions with the mechanism...

  10. Bioactivation of carboxylic acid compounds by UDP-Glucuronosyltransferases to DNA-damaging intermediates: role of glycoxidation and oxidative stress in genotoxicity.

    Science.gov (United States)

    Sallustio, Benedetta C; Degraaf, Yvette C; Weekley, Josephine S; Burcham, Philip C

    2006-05-01

    Nonenzymatic modification of proteins by acyl glucuronides is well documented; however, little is known about their potential to damage DNA. We have previously reported that clofibric acid undergoes glucuronidation-dependent bioactivation to DNA-damaging species in cultured mouse hepatocytes. The aim of this study was to investigate the mechanisms underlying such DNA damage, and to screen chemically diverse carboxylic acid drugs for their DNA-damaging potential in glucuronidation proficient murine hepatocytes. Cells were incubated with each aglycone for 18 h, followed by assessment of compound cytotoxicity using the MTT assay and evaluation of DNA damage using the Comet assay. Relative cytotoxic potencies were ketoprofen > diclofenac, benoxaprofen, nafenopin > gemfibrozil, probenecid > bezafibrate > clofibric acid. At a noncytotoxic (0.1 mM) concentration, only benoxaprofen, nafenopin, clofibric acid, and probenecid significantly increased Comet moments (P Clofibric acid and probenecid exhibited the greatest DNA-damaging potency, producing significant DNA damage at 0.01 mM concentrations. The two drugs produced maximal increases in Comet moment of 4.51 x and 2.57 x control, respectively. The glucuronidation inhibitor borneol (1 mM) abolished the induction of DNA damage by 0.5 mM concentrations of clofibric acid and probenecid. In an in vitro cell-free system, clofibric acid glucuronide was 10 x more potent than glucuronic acid in causing DNA strand-nicking, although both compounds showed similar rates of autoxidation to generate hydroxyl radicals. In cultured hepatocytes, the glycation inhibitor, aminoguanidine, and the iron chelator, desferrioxamine mesylate, inhibited DNA damage by clofibric acid, whereas the free radical scavengers Trolox and butylated hydroxytoluene, and the superoxide dismutase mimetic bis-3,5-diisopropylsalicylate had no effect. In conclusion, clinically relevant concentrations of two structurally unrelated carboxylic acids, probenecid and

  11. Animal model of acid-reflux esophagitis: pathogenic roles of acid/pepsin, prostaglandins, and amino acids.

    Science.gov (United States)

    Takeuchi, Koji; Nagahama, Kenji

    2014-01-01

    Esophagitis was induced in rats within 3 h by ligating both the pylorus and transitional region between the forestomach and glandular portion under ether anesthesia. This esophageal injury was prevented by the administration of acid suppressants and antipepsin drug and aggravated by exogenous pepsin. Damage was also aggravated by pretreatment with indomethacin and the selective COX-1 but not COX-2 inhibitor, whereas PGE2 showed a biphasic effect depending on the dose; a protection at low doses, and an aggravation at high doses, with both being mediated by EP1 receptors. Various amino acids also affected this esophagitis in different ways; L-alanine and L-glutamine had a deleterious effect, while L-arginine and glycine were highly protective, both due to yet unidentified mechanisms. It is assumed that acid/pepsin plays a major pathogenic role in this model of esophagitis; PGs derived from COX-1 are involved in mucosal defense of the esophagus; and some amino acids are protective against esophagitis. These findings also suggest a novel therapeutic approach in the treatment of esophagitis, in addition to acid suppressant therapy. The model introduced may be useful to test the protective effects of drugs on esophagitis and investigate the mucosal defense mechanism in the esophagus.

  12. Bioaccumulation of ultraviolet sunscreen compounds (mycosporine-like amino acids) by the heterotrophic freshwater ciliate Bursaridium living in alpine lakes

    Science.gov (United States)

    Sonntag, Bettina; Kammerlander, Barbara; Summerer, Monika

    2017-01-01

    Abstract Ciliates in shallow alpine lakes are exposed to high levels of incident solar ultraviolet radiation (UVR). We observed the presence of specific sunscreen compounds, the mycosporine-like amino acids (MAAs), in several populations of Bursaridium, a relatively large ciliate species found in such lakes. The populations from 3 highly UV transparent lakes revealed the presence of 7 MAAs (MG, SH, PR, PI, AS, US, and PE) in total concentrations of 3.6–52.4 10−5 μg μg−1 dry weight (DW) per individual, whereas in one glacially turbid and less UV transparent lake, no MAAs were detected in the Bursaridium population. The MAAs in the ciliates generally reflected the composition and relative amounts of the lakes’ seston MAAs, assuming that the ciliates fed on MAA-rich plankton. We experimentally found that naturally acquired MAAs prevented ciliate mortality under simulated UVR and photosynthetically active radiation (PAR) conditions. We further tested the dietary regulation of the MAAs-content in the ciliates under artificial UVR and PAR exposure and found an increase in MAAs concentrations in all treatments. Our assumption was that several stress factors other than irradiation were involved in the synthesis or up-regulation of MAAs. PMID:28690781

  13. Residual wood polymers facilitate compounding of microfibrillated cellulose with poly(lactic acid) for 3D printer filaments

    Science.gov (United States)

    Winter, Armin; Mundigler, Norbert; Holzweber, Julian; Veigel, Stefan; Müller, Ulrich; Kovalcik, Adriana; Gindl-Altmutter, Wolfgang

    2017-12-01

    Microfibrillated cellulose (MFC) is a fascinating material with an obvious potential for composite reinforcement due to its excellent mechanics together with high specific surface area. However, in order to use this potential, commercially viable solutions to important technological challenges have to be found. Notably, the distinct hydrophilicity of MFC prevents efficient drying without loss in specific surface area, necessitating storage and processing in wet condition. This greatly hinders compounding with important technical polymers immiscible with water. Differently from cellulose, the chemistry of the major wood polymers lignin and hemicellulose is much more diverse in terms of functional groups. Specifically, the aromatic moieties present in lignin and acetyl groups in hemicellulose provide distinctly less polar surface-chemical functionality compared to hydroxyl groups which dominate the surface-chemical character of cellulose. It is shown that considerable advantages in the production of MFC-filled poly(lactic acid) filaments for three-dimensional printing can be obtained through the use of MFC containing residual lignin and hemicellulose due to their advantageous surface-chemical characteristics. Specifically, considerably reduced agglomerations of MFC in the filaments in combination with improved printability and improved toughness of printed objects are achieved. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  14. Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

    2010-05-15

    The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

  15. Residual wood polymers facilitate compounding of microfibrillated cellulose with poly(lactic acid) for 3D printer filaments.

    Science.gov (United States)

    Winter, Armin; Mundigler, Norbert; Holzweber, Julian; Veigel, Stefan; Müller, Ulrich; Kovalcik, Adriana; Gindl-Altmutter, Wolfgang

    2018-02-13

    Microfibrillated cellulose (MFC) is a fascinating material with an obvious potential for composite reinforcement due to its excellent mechanics together with high specific surface area. However, in order to use this potential, commercially viable solutions to important technological challenges have to be found. Notably, the distinct hydrophilicity of MFC prevents efficient drying without loss in specific surface area, necessitating storage and processing in wet condition. This greatly hinders compounding with important technical polymers immiscible with water. Differently from cellulose, the chemistry of the major wood polymers lignin and hemicellulose is much more diverse in terms of functional groups. Specifically, the aromatic moieties present in lignin and acetyl groups in hemicellulose provide distinctly less polar surface-chemical functionality compared to hydroxyl groups which dominate the surface-chemical character of cellulose. It is shown that considerable advantages in the production of MFC-filled poly(lactic acid) filaments for three-dimensional printing can be obtained through the use of MFC containing residual lignin and hemicellulose due to their advantageous surface-chemical characteristics. Specifically, considerably reduced agglomerations of MFC in the filaments in combination with improved printability and improved toughness of printed objects are achieved.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'. © 2017 The Author(s).

  16. Tinted windows: The presence of the UV absorbing compounds called mycosporine-like amino acids embedded in the frustules of marine diatoms

    Science.gov (United States)

    Ingalls, Anitra E.; Whitehead, Kenia; Bridoux, Maxime C.

    2010-01-01

    Diatom frustule-bound organic compounds presumably play an important role in biomineralization and constitute an important pool of organic matter preserved in diatom frustule-rich sediments. In this study, detailed analysis of diatom frustule-bound organic matter in opal-rich Southern Ocean plankton and sediments revealed for the first time the presence of low molecular weight, UV light absorbing compounds called mycosporine-like amino acids (MAAs). Chemically cleaned diatom frustule-derived biosilica was dissolved in HF, releasing bound or entrapped organic compounds that were subsequently characterized using liquid chromatography with UV-Vis and electrospray ionization mass spectrometry (LC/PDA/ESI-MS). Palythine ([M+H] + = 245), porphyra-334 ([M+H] + = 347) and shinorine ([M+H] + = 333) were the most abundant MAAs detected in HF digests of plankton and sediment. Traces of asterina ([M+H] + = 289), palythinol ([M+H] + = 303) and palythinic acid ([M+H] + = 329) were also detected. MAAs in cleaned HF digested frustules were up to two orders of magnitude more abundant than methanol extractable MAAs. MAAs are substituted with acid hydrolysable amino acid residues. Our results suggest that MAAs, and not proteins, could be responsible for the high proportion of the amino acids glycine and threonine found in hydrolysates of HF digested diatom-rich environmental samples. Total MAAs accounted for 3-27% of the carbon and 2-18% of total nitrogen in the frustules undergoing various chemical cleaning treatments. This is the first report of MAAs in close association with a mineral phase and we hypothesize that the mineral matrix could stabilize these compounds, thereby enhancing photoprotection against the harmful effects of UV light. The presence of frustule-bound MAAs in sediment cores further suggests the possibility that they could be used in compound-specific isotope analysis of diatom-bound organic matter and as indicators of past solar irradiance.

  17. Measurement and Modeling of Setschenow Constants for Selected Hydrophilic Compounds in NaCl and CaCl2 Simulated Carbon Storage Brines.

    Science.gov (United States)

    Burant, Aniela; Lowry, Gregory V; Karamalidis, Athanasios K

    2017-06-20

    Carbon capture, utilization, and storage (CCUS), a climate change mitigation strategy, along with unconventional oil and gas extraction, generates enormous volumes of produced water containing high salt concentrations and a litany of organic compounds. Understanding the aqueous solubility of organic compounds related to these operations is important for water treatment and reuse alternatives, as well as risk assessment purposes. The well-established Setschenow equation can be used to determine the effect of salts on aqueous solubility. However, there is a lack of reported Setschenow constants, especially for polar organic compounds. In this study, the Setschenow constants for selected hydrophilic organic compounds were experimentally determined, and linear free energy models for predicting the Setschenow constant of organic chemicals in concentrated brines were developed. Solid phase microextraction was employed to measure the salting-out behavior of six selected hydrophilic compounds up to 5 M NaCl and 2 M CaCl 2 and in Na-Ca-Cl brines. All compounds, which include phenol, p-cresol, hydroquinone, pyrrole, hexanoic acid, and 9-hydroxyfluorene, exhibited log-linear behavior up to these concentrations, meaning Setschenow constants previously measured at low salt concentrations can be extrapolated up to high salt concentrations for hydrophilic compounds. Setschenow constants measured in NaCl and CaCl 2 brines are additive for the compounds measured here; meaning Setschenow constants measured in single salt solutions can be used in multiple salt solutions. The hydrophilic compounds in this study were selected to elucidate differences in salting-out behavior based on their chemical structure. Using data from this study, as well as literature data, linear free energy relationships (LFERs) for prediction of NaCl, CaCl 2 , LiCl, and NaBr Setschenow constants were developed and validated. Two LFERs were improved. One LFER uses the Abraham solvation parameters, which include

  18. Predicting nucleic acid binding interfaces from structural models of proteins.

    Science.gov (United States)

    Dror, Iris; Shazman, Shula; Mukherjee, Srayanta; Zhang, Yang; Glaser, Fabian; Mandel-Gutfreund, Yael

    2012-02-01

    The function of DNA- and RNA-binding proteins can be inferred from the characterization and accurate prediction of their binding interfaces. However, the main pitfall of various structure-based methods for predicting nucleic acid binding function is that they are all limited to a relatively small number of proteins for which high-resolution three-dimensional structures are available. In this study, we developed a pipeline for extracting functional electrostatic patches from surfaces of protein structural models, obtained using the I-TASSER protein structure predictor. The largest positive patches are extracted from the protein surface using the patchfinder algorithm. We show that functional electrostatic patches extracted from an ensemble of structural models highly overlap the patches extracted from high-resolution structures. Furthermore, by testing our pipeline on a set of 55 known nucleic acid binding proteins for which I-TASSER produces high-quality models, we show that the method accurately identifies the nucleic acids binding interface on structural models of proteins. Employing a combined patch approach we show that patches extracted from an ensemble of models better predicts the real nucleic acid binding interfaces compared with patches extracted from independent models. Overall, these results suggest that combining information from a collection of low-resolution structural models could be a valuable approach for functional annotation. We suggest that our method will be further applicable for predicting other functional surfaces of proteins with unknown structure. Copyright © 2011 Wiley Periodicals, Inc.

  19. Selective cleavage of the C(α)-C(β) linkage in lignin model compounds via Baeyer-Villiger oxidation.

    Science.gov (United States)

    Patil, Nikhil D; Yao, Soledad G; Meier, Mark S; Mobley, Justin K; Crocker, Mark

    2015-03-21

    Lignin is an amorphous aromatic polymer derived from plants and is a potential source of fuels and bulk chemicals. Herein, we present a survey of reagents for selective stepwise oxidation of lignin model compounds. Specifically, we have targeted the oxidative cleavage of Cα-Cβ bonds as a means to depolymerize lignin and obtain useful aromatic compounds. In this work, we prepared several lignin model compounds that possess structures, characteristic reactivity, and linkages closely related to the parent lignin polymer. We observed that selective oxidation of benzylic hydroxyl groups, followed by Baeyer-Villiger oxidation of the resulting ketones, successfully cleaves the Cα-Cβ linkage in these model compounds.

  20. Mathematical Modeling of a Transient Vibration Control Strategy Using a Switchable Mass Stiffness Compound System

    Directory of Open Access Journals (Sweden)

    Diego Francisco Ledezma-Ramirez

    2014-01-01

    Full Text Available A theoretical control strategy for residual vibration control resulting from a shock pulse is studied. The semiactive control strategy is applied in a piecewise linear compound model and involves an on-off logic to connect and disconnect a secondary mass stiffness system from the primary isolation device, with the aim of providing high energy dissipation for lightly damped systems. The compound model is characterized by an energy dissipation mechanism due to the inelastic collision between the two masses and then viscous damping is introduced and its effects are analyzed. The objective of the simulations is to evaluate the transient vibration response in comparison to the results for a passive viscously damped single degree-of-freedom system considered as the benchmark or reference case. Similarly the decay in the compound system is associated with an equivalent decay rate or logarithmic decrement for direct comparison. It is found how the compound system provides improved isolation compared to the passive system, and the damping mechanisms are explained.

  1. Investigation of the synergistic effect of alcoholic compounds on the extraction of H3PO4 from Syrian wet phosphoric acid by TBP

    International Nuclear Information System (INIS)

    Abdulbaki, M. K.; Shino, O.; Wahoud, A.

    2006-01-01

    This paper studies the synergistic effects of alcoholic compounds such as isoamyl alcohol. Pentanol, hexanol and heptanol on the extraction of H 3 PO 4 from Syrian phosphoric acid by (TBP). The possibility to use these alcoholic compounds as a diluent instead of kerosene was also studied. The results show that the alcoholic compounds has bigger extraction yield than (TBP) diluted in kerosene. The alcoholic compounds has an important synergistic effect, when it was used as a diluent instead of kerosene, on the extraction of H 3 PO 4 by (TBP) and they have a bigger extraction yield and the quicker phase separation comparing with kerosene. Extraction of uranium, fluoride, sulfate and heavy metals is relatively small. (Authors)

  2. Increasing human Th17 differentiation through activation of orphan nuclear receptor retinoid acid-related orphan receptor γ (RORγ) by a class of aryl amide compounds.

    Science.gov (United States)

    Zhang, Wei; Zhang, Jing; Fang, Leiping; Zhou, Ling; Wang, Shuai; Xiang, Zhijun; Li, Yuan; Wisely, Bruce; Zhang, Guifeng; An, Gang; Wang, Yonghui; Leung, Stewart; Zhong, Zhong

    2012-10-01

    In a screen for small-molecule inhibitors of retinoid acid-related orphan receptor γ (RORγ), we fortuitously discovered that a class of aryl amide compounds behaved as functional activators of the interleukin 17 (IL-17) reporter in Jurkat cells. Three of these compounds were selected for further analysis and found to activate the IL-17 reporter with potencies of ∼0.1 μM measured by EC₅₀. These compounds were shown to directly bind to RORγ by circular dichroism-based thermal stability experiments. Furthermore, they can enhance an in vitro Th17 differentiation process in human primary T cells. As RORγ remains an orphan nuclear receptor, discovery of these aryl amide compounds as functional agonists will now provide pharmacological tools for us to dissect functions of RORγ and facilitate drug discovery efforts for immune-modulating therapies.

  3. AMPK modulatory activity of olive–tree leaves phenolic compounds: Bioassay-guided isolation on adipocyte model and in silico approach

    Science.gov (United States)

    Jiménez-Sánchez, Cecilia; Olivares-Vicente, Mariló; Rodríguez-Pérez, Celia; Herranz-López, María; Lozano-Sánchez, Jesús; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Encinar, José Antonio; Micol, Vicente

    2017-01-01

    Scope Olive-tree polyphenols have demonstrated potential for the management of obesity-related pathologies. We aimed to explore the capacity of Olive-tree leaves extract to modulate triglyceride accumulation and AMP-activated protein kinase activity (AMPK) on a hypertrophic adipocyte model. Methods Intracellular triglycerides and AMPK activity were measured on the hypertrophic 3T3-L1 adipocyte model by AdipoRed and immunofluorescence microscopy, respectively. Reverse phase high performance liquid chromatography coupled to time-of-flight mass detection with electrospray ionization (RP-HPLC-ESI-TOF/MS) was used for the fractionation of the extract and the identification of the compounds. In-silico molecular docking of the AMPK alpha-2, beta and gamma subunits with the identified compounds was performed. Results Olive-tree leaves extract decreased the intracellular lipid accumulation through AMPK-dependent mechanisms in hypertrophic adipocytes. Secoiridoids, cinnamic acids, phenylethanoids and phenylpropanoids, flavonoids and lignans were the candidates predicted to account for this effect. Molecular docking revealed that some compounds may be AMPK-gamma modulators. The modulatory effects of compounds over the alpha and beta AMPK subunits appear to be less probable. Conclusions Olive-tree leaves polyphenols modulate AMPK activity, which may become a therapeutic aid in the management of obesity-associated disturbances. The natural occurrence of these compounds may have important nutritional implications for the design of functional ingredients. PMID:28278224

  4. Compound-Specific Carbon, Nitrogen, and Hydrogen Isotopic Ratios for Amino Acids in CM and CR Chondrites and their use in Evaluating Potential Formation Pathways

    Science.gov (United States)

    Elsila, Jamie E.; Charnley, Steven B.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Stable hydrogen, carbon, and nitrogen isotopic ratios (oD, 013C, and olSN) of organic compounds can revcal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound-specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1I2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CRZ Graves Nunataks (GRA) 95229, CRZ Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing ODC and increasing oD with increasing carbon number in the aH, (l-NH2 amino acids that correspond to predictions made for formation via Streckercyanohydrin synthesis. We also observe light ODC signatures for -alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight-chain, amine-terminal amino acids (n-ro-amino acids). Higher deuterium enrichments are observed in amethyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than CM chondrites, reflecting different parent-body chemistry.

  5. Drosophila melanogaster as a model system for the evaluation of anti-aging compounds.

    Science.gov (United States)

    Jafari, Mahtab

    2010-01-01

    Understanding the causes of aging is a complex problem due to the multiple factors that influence aging, which include genetics, environment, metabolism and reproduction, among others. These multiple factors create logistical difficulties in the evaluation of anti-aging agents. There is a need for good model systems to evaluate potential anti-aging compounds. The model systems used should represent the complexities of aging in humans, so that the findings may be extrapolated to human studies, but they should also present an opportunity to minimize the variables so that the experimental results can be accurately interpreted. In addition to positively affecting lifespan, the impact of the compound on the physiologic confounders of aging, including fecundity and the health span--the period of life where an organism is generally healthy and free from serious or chronic illness--of the model organism needs to be evaluated. Fecundity is considered a major confounder of aging in fruit flies. It is well established that female flies that are exposed to toxic substances typically reduce their dietary intake and their reproductive output and display an artifactual lifespan extension. As a result, drugs that achieve longevity benefits by reducing fecundity as a result of diminished food intake are probably not useful candidates for eventual treatment of aging in humans and should be eliminated during the screening process. Drosophila melanogaster provides a suitable model system for the screening of anti-aging compounds as D. melanogaster and humans have many conserved physiological and biological pathways. In this paper, I propose an algorithm to screen anti-aging compounds using Drosophila melanogaster as a model system.

  6. Mathematical model of gluconic acid fermentation by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Takamatsu, T.; Shioya, S.; Furuya, T.

    1981-11-01

    A mathematical model for the study of gluconic acid fermentation by Aspergillus niger has been developed. The model has been deduced from the basic biological concept of multicellular filamentous microorganisms, i.e. cell population balance. It can be used to explain the behaviour of both batch and continuous cultures, even when in a lag phase. A new characteristic, involving the existence of dual equilibrium stages during fermentation, has been predicted using this mathematical model. (Refs. 6).

  7. Predicting acid dew point with a semi-empirical model

    International Nuclear Information System (INIS)

    Xiang, Baixiang; Tang, Bin; Wu, Yuxin; Yang, Hairui; Zhang, Man; Lu, Junfu

    2016-01-01

    Highlights: • The previous semi-empirical models are systematically studied. • An improved thermodynamic correlation is derived. • A semi-empirical prediction model is proposed. • The proposed semi-empirical model is validated. - Abstract: Decreasing the temperature of exhaust flue gas in boilers is one of the most effective ways to further improve the thermal efficiency, electrostatic precipitator efficiency and to decrease the water consumption of desulfurization tower, while, when this temperature is below the acid dew point, the fouling and corrosion will occur on the heating surfaces in the second pass of boilers. So, the knowledge on accurately predicting the acid dew point is essential. By investigating the previous models on acid dew point prediction, an improved thermodynamic correlation formula between the acid dew point and its influencing factors is derived first. And then, a semi-empirical prediction model is proposed, which is validated with the data both in field test and experiment, and comparing with the previous models.

  8. IN SILICO MODELLING OF CYTOTOXIC BEHAVIOUR OF ANTI-LEUKEMIC COMPOUNDS ON HL-60 CELL LINE

    Directory of Open Access Journals (Sweden)

    David Ebuka Arthur

    2016-05-01

    Full Text Available This research employs multiple linear regression technique in the modelling of some potent anti-leukemic compounds using paDEL molecular descriptor software calculator, to identify the best relationship between the chemical structure and toxicities of the anticancer datasets against some leukemic cell lines (HL-60. Statistical parameters such as Q2 and R2pred (test set were computed to validate the strength of the model, while Williams plot was used to assess its applicability domain. The mean effects of the molecular descriptors in the models were calculated to illuminate the principal properties of the molecules responsible for their cytotoxicity.

  9. DEVELOPMENT AND VALIDATION OF AN AIR-TO-BEEF FOOD CHAIN MODEL FOR DIOXIN-LIKE COMPOUNDS

    Science.gov (United States)

    A model for predicting concentrations of dioxin-like compounds in beef is developed and tested. The key premise of the model is that concentrations of these compounds in air are the source term, or starting point, for estimating beef concentrations. Vapor-phase concentrations t...

  10. The radiation chemistry of the purine bases within DNA and related model compounds

    International Nuclear Information System (INIS)

    Cadet, J.; Berger, M.; Shaw, A.

    1986-01-01

    Both the direct and indirect effects of ionizing radiations are believed to contribute to the chemical changes induced in cellular DNA. Relevant information on the possible degradation pathways has been provided by studies using DNA model compounds, the major proportion of which have focused on pyrimidine components and sugar derivatives. With the development of powerful analytical tools such as high performance liquid chromatography and soft ionization mass spectrometry techniques, progress has recently been made in the elucidation of the nature of the radiation-induced chemical modifications of purine bases in DNA and related nucleosides and nucleotides. This short review details recent aspects of the radiation-induced degradation of adenine and guanine bases in DNA and its model compounds as the result of both direct and indirect effects. 11 refs., 2 figs., 1 tab

  11. Chapter 8: Pyrolysis Mechanisms of Lignin Model Compounds Using a Heated Micro-Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Robichaud, David J.; Nimlos, Mark R.; Ellison, G. Barney

    2015-10-03

    Lignin is an important component of biomass, and the decomposition of its thermal deconstruction products is important in pyrolysis and gasification. In this chapter, we investigate the unimolecular pyrolysis chemistry through the use of singly and doubly substituted benzene molecules that are model compounds representative of lignin and its primary pyrolysis products. These model compounds are decomposed in a heated micro-reactor, and the products, including radicals and unstable intermediates, are measured using photoionization mass spectrometry and matrix isolation infrared spectroscopy. We show that the unimolecular chemistry can yield insight into the initial decomposition of these species. At pyrolysis and gasification severities, singly substituted benzenes typically undergo bond scission and elimination reactions to form radicals. Some require radical-driven chain reactions. For doubly substituted benzenes, proximity effects of the substituents can change the reaction pathways.

  12. Optimization of ultrasound-assisted extraction of phenolic compounds, antioxidants and rosmarinic acid from perilla leaves using response surface methodology

    Directory of Open Access Journals (Sweden)

    Hui-Zhen LI

    Full Text Available Abstract Response surface methodology (RSM was used to optimize ultrasound-assisted extraction (UAE of functional components from perilla leaves. The factors investigated were ethanol concentration, extraction temperature, and extraction time. The results revealed that ethanol concentration had significant effects on all extraction parameters. Based on the RSM results, the optimal conditions were an ethanol concentration of 56%, a UAE temperature of 54 °C, and a UAE time of 55 min. Under these conditions, the experimental TPC (total phenolic content, RA (rosmarinic acid, FRAP (ferric reducing antioxidant power and DPPH (1,1-diphenyl-2-picrylhydrazyl values were 48.85 mg GAE/g DW (mg gallic acid equivalent /g of dry weight, 31.02 mg/g DW, 85.55 μmol Fe2+/g DW and 73.35%, respectively. The experimental values were in agreement with those predicted by RSM models, confirming suitability of the model employed and the success of RSM for optimization of the extraction conditions.

  13. Preparation and studying acid - base properties of the compound a -mono thiosemicarbazide isatin-5-Sodium sulfonate (α-MTI-5-SO3Na)

    International Nuclear Information System (INIS)

    Al-Azrak, A.

    2015-01-01

    This research aims to prepare organic compounds containing functional groups and have analytical properties to use as analytical reagents for determination of metal ions by spectrophotometric methods as acid-base indicators and as indicators for metal ions in EDTA titrations in this paper was prepared the compound ((α-mono thiosemicarbazide isatien -5-sodium sulfonate) it showed analytical properties and significant practical applications this compound has in acidic medium yellow color while in the basic medium sharply changes its color to red color the value of pKa of this compound has been calculated by spectrophotometric method and was equal to (8.860±0.054) the pH transition range was between (8.20 to 9.8) the indicator was used for determination the end point of the titration standard samples of solution (0.1M, NaOH) with standard solution of 0.1M, HCI, and in titration standard samples of solution (0.1M, CH 3 COOH) with standard solution of 0.1M NaOH the results were compared with the results obtained by reference titrimetric methods the statistical treatment for allresults shows that the end point determination using acid - base ((α-MTI-5-SO 3 Na) is the most accurate. (author)

  14. Compound and Geometry-Dependent Pre-Compound Models to Calculate the Nuclear Data for Fusion Reactors

    International Nuclear Information System (INIS)

    Jahn, Helmut

    2005-01-01

    Compound and geometry-dependent pre-compound nuclear reactions are very useful concepts of nuclear theory to calculate cross sections of neutrons of around 14 MeV and below scattered by nuclei of material of installations producing energy of nuclear fusion. If these concepts are used to discuss and improve the experimental data they have to be completed by DWBA-type contributions to the small-step region of the incident neutron which can account for the angular distribution of the scattered neutron because there is the difficulty to separate experimentally the incoming from the scattered beam. The angle integrated cross-section in this region can be shown to be accounted for the surface dependent components of Blanns geometry-dependent precompound mechanism of the statistical state density and level density contributions of the compound and precompound components beeing calculated according to the recent developments of Anzaldo using the analytic number theory. The experimental data have been taken from the results of Hermsdorf, Meister, Sassonov, Seeliger, Seidel, Shahin and of A.Takahashi

  15. Molecular modeling of nucleic Acid structure: electrostatics and solvation.

    Science.gov (United States)

    Bergonzo, Christina; Galindo-Murillo, Rodrigo; Cheatham, Thomas E

    2014-12-19

    This unit presents an overview of computer simulation techniques as applied to nucleic acid systems, ranging from simple in vacuo molecular modeling techniques to more complete all-atom molecular dynamics treatments that include an explicit representation of the environment. The third in a series of four units, this unit focuses on critical issues in solvation and the treatment of electrostatics. UNITS 7.5 & 7.8 introduced the modeling of nucleic acid structure at the molecular level. This included a discussion of how to generate an initial model, how to evaluate the utility or reliability of a given model, and ultimately how to manipulate this model to better understand its structure, dynamics, and interactions. Subject to an appropriate representation of the energy, such as a specifically parameterized empirical force field, the techniques of minimization and Monte Carlo simulation, as well as molecular dynamics (MD) methods, were introduced as a way of sampling conformational space for a better understanding of the relevance of a given model. This discussion highlighted the major limitations with modeling in general. When sampling conformational space effectively, difficult issues are encountered, such as multiple minima or conformational sampling problems, and accurately representing the underlying energy of interaction. In order to provide a realistic model of the underlying energetics for nucleic acids in their native environments, it is crucial to include some representation of solvation (by water) and also to properly treat the electrostatic interactions. These subjects are discussed in detail in this unit. Copyright © 2014 John Wiley & Sons, Inc.

  16. Novel Caffeic Acid Nanocarrier: Production, Characterization, and Release Modeling

    Directory of Open Access Journals (Sweden)

    Milad Fathi

    2013-01-01

    Full Text Available This paper deals with the development of novel nanocarriers using layer by layer carbohydrate coating of caffeic acid loaded solid lipid nanoparticles (SLNs to improve stability and colon delivery of the poorly water-soluble caffeic acid. Three biopolymers (chitosan, alginate, and pectin in different concentrations (0.1, 0.25, and 0.5% were electrostatically coated over the SLN surface. The size and zeta potential of produced nanocarriers were measured using photon correlation spectroscopy. Mathematical models (i.e., zero-order, first-order, Higuchi, Ritger-Peppas, reciprocal powered time, Weibull, and quadratic models were used to describe the release and kinetic modeling in gastrointestinal solution (GIS. Also, antioxidant activity of caffeic acid during the release in GIS was investigated using DPPH and reducing activity methods. The prepared treatments coated by alginate-chitosan as well as pectin-chitosan coated SLN at the concentration of 0.1% showed nanosized bead; the latter efficiently retarded the release of caffeic acid in gastric media up to 2.5 times higher than that of SLN. Zeta potential values of coated samples were found to significantly increase in comparison to SLN indicating the higher stability of produced nanocarriers. Antioxidant activity of caffeic acid after gastric release did not result in the same trend as observed for caffeic acid release from different treatments; however, in line with less caffeic acid release in the intestine solution by the effect of coating, lower antioxidant activity was determined at the end stage of the experiment.

  17. Stability studies of endocrine disrupting tributyltin and triphenyltin compounds in an artificial sea water model.

    Science.gov (United States)

    Novotny, Ladislav; Sharaf, Leyla; Abdel-Hamid, Mohammed E; Brtko, Julius

    2018-01-01

    Triorganotins belong to toxic components present predominantly in antifouling paints for marine vessels. Tributyltin/triphenyltin at pico- or nanomolar concentrations in sea water are known to induce an irreversible sexual abnormality in females of over 190 marine species, an "imposex" phenomenon - the superimposition of male genitalia on a female. Moreover, trialkyltins and triaryltins function as potent nuclear retinoid X receptors (RXR) agonists. In mammals, triorganotin compounds induce immunosuppressive, metabolic, reproductive or developmental effects. Toxic effects of triorganotins warrant the need for monitoring of their long-lasting presence in the environment. This study brings novel data on the stability of two triorganotin compounds in artificial sea water model obtained by applying ultra-pressure liquid chromatography (UPLC) and gas chromatography-mass spectrometry (GC-MS) methods. Stability of tributyltin and triphenyltin chlorides was studied for 180 days and the degradation kinetic parameters were obtained. Tributyltin chloride was the less stable with the degradation kinetic parameters Kdeg = 0.00014 day-1 and t1/2 = 4950 days (13.6 years). Kdeg of the more stable triphenyltin chloride was determined to be Kdeg = 0.00006 day-1 with t1/2 = 11550 days (31.6 years). Since similar stability data of triorganotin compounds were not published previously, we report high stability for both tested compounds, which indicates a significant environmental problem when these substances enter sea water and later coastal sediments.

  18. Hydrodeoxygenation of O-containing polycyclic model compounds using a novel organometallic catalyst-precursor

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, S.R.; Song, C.S.; Schobert, H.H. [Pennsylvania State University, University Park, PA (United States). Dept. of Materials Science and Engineering

    1996-09-05

    Compounds containing oxygen functional groups, especially phenols, are undesirable components of coal-derived liquids. Removal of these compounds from the products of coal liquefaction is required. A beneficial alternative would be the removal of these compounds, or the prevention of their formation, during the liquefaction reaction itself, rather than as a separate processing step. A novel organometallic catalyst precursor containing Co and Mo has been studied as a potential hydrogenation catalyst for coal liquefaction. To ascertain the hydrodeoxygenation activity of this catalyst under liquefaction conditions, model compounds were investigated. Anthrone, 2,6-di-r-btuyl-4-methyl-phenol, dinaphthyl ether and xanthene were reacted in the presence of the Co-Mo catalyst precursor and a precursor containing only Mo over a range of temperatures, providing a comparison of conversions to deoxygenated products. These conversions give an indication of the hydrodeoxygenating abilities of organometallic catalyst precursors within a coal liquefaction system. For example, at 400{degree}C dinaphthyl ether was converted 100% (4.5% O-containing products) in the presence of the Co-Mo organometallic precursor, compared to 76.5% conversion (7.4% O-products) in the presence of the Mo catalyst.

  19. The Extract of Aster Koraiensis Prevents Retinal Pericyte Apoptosis in Diabetic Rats and Its Active Compound, Chlorogenic Acid Inhibits AGE Formation and AGE/RAGE Interaction

    Directory of Open Access Journals (Sweden)

    Junghyun Kim

    2016-09-01

    Full Text Available Retinal capillary cell loss is a hallmark of early diabetic retinal changes. Advanced glycation end products (AGEs are believed to contribute to retinal microvascular cell loss in diabetic retinopathy. In this study, the protective effects of Aster koraiensis extract (AKE against damage to retinal vascular cells were investigated in streptozotocin (STZ-induced diabetic rats. To examine this issue further, AGE accumulation, nuclear factor-kappaB (NF-κB and inducible nitric oxide synthase (iNOS were investigated using retinal trypsin digests from streptozotocin-induced diabetic rats. In the diabetic rats, TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling-positive retinal microvascular cells were markedly increased. Immunohistochemical studies revealed that AGEs were accumulated within the retinal microvascular cells, and this accumulation paralleled the activation of NF-κB and the expression of iNOS in the diabetic rats. However, AKE prevented retinal microvascular cell apoptosis through the inhibition of AGE accumulation and NF-κB activation. Moreover, to determine the active compounds of AKE, two major compounds, chlorogenic acid and 3,5-di-O-caffeoylquinic acid, were tested in an in vitro assay. Among these compounds, chlorogenic acid significantly reduced AGE formation as well as AGE/RAGE (receptor for AGEs binding activity. These results suggest that AKE, particularly chlorogenic acid, is useful in inhibiting AGE accumulation in retinal vessels and exerts a preventive effect against the injuries of diabetic retinal vascular cells.

  20. The effect of drying temperatures on antioxidant activity, phenolic compounds, fatty acid composition and tocopherol contents in citrus seed and oils.

    Science.gov (United States)

    Al Juhaimi, Fahad; Özcan, Mehmet Musa; Uslu, Nurhan; Ghafoor, Kashif

    2018-01-01

    In this study, the effect of drying temperature on antioxidant activity, phenolic compounds, fatty acid composition and tocopherol content of citrus seeds and oils were studied. Kinnow mandarin seed, dried at 60 °C, exhibited the highest antioxidant activity. Orlendo orange seed had the maximum total phenolic content and α-tocopherol content, with a value of 63.349 mg/100 g and 28.085 mg/g (control samples), respectively. The antioxidant activity of Orlendo orange seed (63.349%) was higher than seeds of Eureka lemon (55.819%) and Kinnow mandarin (28.015%), while the highest total phenolic content was found in seeds of Kinnow mandarin, followed by Orlendo orange and Eureka lemon (113.132). 1.2-Dihydroxybenzene (13.171), kaempferol (10.780), (+)-catechin (9.341) and isorhamnetin (7.592) in mg/100 g were the major phenolic compounds found in Kinnow mandarin. Among the unsaturated fatty acids, linoleic acid was the most abundant acid in all oils, which varied from 44.4% (dried at 80 °C) to 46.1% (dried at 70 °C), from 39.0% (dried at 60 °C) to 40.0% (dried at 70 °C). The total phenolic content, antioxidant activity and phenolic compounds of citrus seeds and tocopherol content of seed oils were significantly affected by drying process and varied depending on the drying temperature.

  1. Phenolic compounds reduce formation of Nε-(carboxymethyl)lysine and pyrazines formed by Maillard reactions in a model bread system.

    Science.gov (United States)

    Mildner-Szkudlarz, Sylwia; Siger, Aleksander; Szwengiel, Artur; Przygoński, Krzysztof; Wojtowicz, Elżbieta; Zawirska-Wojtasiak, Renata

    2017-09-15

    This study had the objective of determining the antiglycation activity of phenolic compounds (PCs) ((+)-catechin, quercetin, gallic, ferulic, and caffeic acids) added to a model bread with regards to the inhibition of N ε -(carboxymethyl)lysine (CML) formation. PCs were found to significantly reduce CML (31.77%-87.56%), even at the lowest concentration, with the exception of ferulic acid (FA). The strongest inhibitory effect of FA (∼62%) appeared when concentration was increased to 1.0g/100g of flour. The available lysine losses (0.00%-90.51%) showed a significant correlation (0.853-0.990) with effectiveness of CML inhibition, except in the case of samples with FA. (+)-Catechin reduced CML levels the most, probably due to its structure-antioxidant activity relationship, its thermal stability (∼51% loss), and its reactivity with ε-lysine side chains (∼40.77% loss). Although the bread supplemented with PCs contained low levels of CML, this process may adversely affect bread flavor, reducing the formation of pyrazines (1.10%-80.77%). Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Parity violating NN forcES in the quark compound bag model

    International Nuclear Information System (INIS)

    Simonov, Yu.A.

    1982-01-01

    Parity violation (PV) in the interaction is considered as due to the Weinberg-Salam quark-quark interaction inside the six-quark bag. The initial and final strong interaction is described within the same quark compound bag (QCB) model, where the NN coupling to the six quark QCB is defined from the NN experimental data. The resulting PV amplitude contains no free parameters and allows therefore an unambiguous test of the QCB model. An estimate of the 1 S 0 → 3 P 0 contribution to the proton-proton asymmetry is in a rough agreement with experimental data [ru

  3. Measurement of infrared refractive indices of organic and organophosphorous compounds for optical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Tonkyn, Russell G.; Danby, Tyler O.; Birnbaum, Jerome C.; Taubman, Matthew S.; Bernacki, Bruce E.; Johnson, Timothy J.; Myers, Tanya L.

    2017-05-03

    The complex optical refractive index contains the optical constants, n($\\tilde{u}$)and k($\\tilde{u}$), which correspond to the dispersion and absorption of light within a medium, respectively. By obtaining the optical constants one can in principle model most optical phenomena in media and at interfaces including reflection, refraction and dispersion. We have developed improved protocols based on the use of multiple path lengths to determine the optical constants for dozens of liquids, including organic and organophosphorous compounds. Detailed description of the protocols to determine the infrared indices will be presented, along with preliminary results using the constants with their applications to optical modeling.

  4. Isoflavonoid compounds extracted from Pueraria lobata suppress alcohol preference in a pharmacogenetic rat model of alcoholism.

    Science.gov (United States)

    Lin, R C; Guthrie, S; Xie, C Y; Mai, K; Lee, D Y; Lumeng, L; Li, T K

    1996-06-01

    The extract from an edible vine, Pueraria lobata, has long been used in China to lessen alcohol intoxication. We have previously shown that daidzin, one of the major components from this plant extract, is efficacious in lowering blood alcohol levels and shortens sleep time induced by alcohol ingestion. This study was conducted to test the antidipsotropic effect of daidzin and two other major isoflavonoids, daidzein and puerarin, from Pueraria lobata administered by the oral route. An alcohol-preferring rat model, the selectively-bred P line of rats, was used for the study. All three isoflavonoid compounds were effective in suppressing voluntary alcohol consumption by the P rats. When given orally to P rats at a dose of 100 mg/kg/day, daidzein, daidzin, and puerarin decreased ethanol intake by 75%, 50%, and 40%, respectively. The decrease in alcohol consumption was accompanied by an increase in water intake, so that the total fluid volume consumed daily remained unchanged. The effects of these isoflavonoid compounds on alcohol and water intake were reversible. Suppression of alcohol consumption was evident after 1 day of administration and became maximal after 2 days. Similarly, alcohol preference returned to baseline levels 2 days after discontinuation of the isoflavonoids. Rats receiving the herbal extracts ate the same amounts of food as control animals, and they gained weight normally during the experiments. When administered orally, none of these compounds affected the activities of liver alcohol dehydrogenase and aldehyde dehydrogenase. Therefore, the reversal of alcohol preference produced by these compounds may be mediated via the CNS. Data demonstrate that isoflavonoid compounds extracted from Pueraria lobata is effective in suppressing the appetite for alcohol when taken orally, raising the possibility that other constituents of edible plants may exert similar and more potent actions.

  5. Simple intake and pharmacokinetic modeling to characterize exposure of Americans to perfluoroctanoic acid, PFOA.

    Science.gov (United States)

    Lorber, Matthew; Egeghy, Peter P

    2011-10-01

    Models for assessing intakes of perfluorooctanoic acid, PFOA, are described and applied. One model is based on exposure media concentrations and contact rates. This model is applied to general population exposures for adults and 2-year old children. The other model is a simple one-compartment, first-order pharmacokinetic (PK) model. Parameters for this model include a rate of elimination of PFOA and a blood volume of distribution. The model was applied to data from the National Health and Nutritional Examination Survey, NHANES, to backcalculate intakes. The central tendency intake estimate for adults and children based on exposure media concentrations and contact rates were 70 and 26 ng/day, respectively. The central tendency adult intake derived from NHANES data was 56 and 37 ng/day for males and females, respectively. Variability and uncertainty discussions regarding the intake modeling focus on lack of data on direct exposure to PFOA used in consumer products, precursor compounds, and food. Discussions regarding PK modeling focus on the range of blood measurements in NHANES, the appropriateness of the simple PK model, and the uncertainties associated with model parameters. Using the PK model, the 10th and 95th percentile long-term average adult intakes of PFOA are 15 and 130 ng/day.

  6. Estimating effectiveness in HIV prevention trials with a Bayesian hierarchical compound Poisson frailty model

    Science.gov (United States)

    Coley, Rebecca Yates; Browna, Elizabeth R.

    2016-01-01

    Inconsistent results in recent HIV prevention trials of pre-exposure prophylactic interventions may be due to heterogeneity in risk among study participants. Intervention effectiveness is most commonly estimated with the Cox model, which compares event times between populations. When heterogeneity is present, this population-level measure underestimates intervention effectiveness for individuals who are at risk. We propose a likelihood-based Bayesian hierarchical model that estimates the individual-level effectiveness of candidate interventions by accounting for heterogeneity in risk with a compound Poisson-distributed frailty term. This model reflects the mechanisms of HIV risk and allows that some participants are not exposed to HIV and, therefore, have no risk of seroconversion during the study. We assess model performance via simulation and apply the model to data from an HIV prevention trial. PMID:26869051

  7. Stochastic Interest Model Based on Compound Poisson Process and Applications in Actuarial Science

    Directory of Open Access Journals (Sweden)

    Shilong Li

    2017-01-01

    Full Text Available Considering stochastic behavior of interest rates in financial market, we construct a new class of interest models based on compound Poisson process. Different from the references, this paper describes the randomness of interest rates by modeling the force of interest with Poisson random jumps directly. To solve the problem in calculation of accumulated interest force function, one important integral technique is employed. And a conception called the critical value is introduced to investigate the validity condition of this new model. We also discuss actuarial present values of several life annuities under this new interest model. Simulations are done to illustrate the theoretical results and the effect of parameters in interest model on actuarial present values is also analyzed.

  8. Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis

    International Nuclear Information System (INIS)

    Van Beneden, Katrien; Geers, Caroline; Pauwels, Marina; Mannaerts, Inge; Wissing, Karl M.; Van den Branden, Christiane; Grunsven, Leo A. van

    2013-01-01

    Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors. - Highlights: • Valproic acid is a potent antiproteinuric drug, whereas trichostatin A is not. • Trichostatin A and valproic acid reduce kidney fibrosis in doxorubicin nephropathy. • Both valproic acid and trichostatin A attenuate renal inflammation

  9. Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Van Beneden, Katrien, E-mail: kvbenede@vub.ac.be [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Geers, Caroline [Department of Pathology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Pauwels, Marina [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Mannaerts, Inge [Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Wissing, Karl M. [Department of Nephrology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Van den Branden, Christiane [Department of Human Anatomy, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium); Grunsven, Leo A. van, E-mail: lvgrunsv@vub.ac.be [Department of Cell Biology, Liver Cell Biology Lab, Vrije Universiteit Brussel, Brussels (Belgium)

    2013-09-01

    Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors. - Highlights: • Valproic acid is a potent antiproteinuric drug, whereas trichostatin A is not. • Trichostatin A and valproic acid reduce kidney fibrosis in doxorubicin nephropathy. • Both valproic acid and trichostatin A attenuate renal inflammation.

  10. Fast fission phenomenon, deep inelastic reactions and compound nucleus formation described within a dynamical macroscopic model

    International Nuclear Information System (INIS)

    Gregoire, C.; Ngo, C.; Remaud, B.

    1982-01-01

    We present a dynamical model to describe dissipative heavy ion reactions. It treats explicitly the relative motion of the two ions, the mass asymmetry of the system and the projection of the isospin of each ion. The deformations, which are induced during the collision, are simulated with a time-dependent interaction potential. This is done by a time-dependent transition between a sudden interaction potential in the entrance channel and an adiabatic potential in the exit channel. The model allows us to compute the compound-nucleus cross section and multidifferential cross-sections for deep inelastic reactions. In addition, for some systems, and under certain conditions which are discussed in detail, a new dissipative heavy ion collision appears: fast-fission phenomenon which has intermediate properties between deep inelastic and compound nucleus reactions. The calculated properties concerning fast fission are compared with experimental results and reproduce some of those which could not be understood as belonging to deep inelastic or compound-nucleus reactions. (orig.)

  11. Acidity in DMSO from the embedded cluster integral equation quantum solvation model.

    Science.gov (United States)

    Heil, Jochen; Tomazic, Daniel; Egbers, Simon; Kast, Stefan M

    2014-04-01

    The embedded cluster reference interaction site model (EC-RISM) is applied to the prediction of acidity constants of organic molecules in dimethyl sulfoxide (DMSO) solution. EC-RISM is based on a self-consistent treatment of the solute's electronic structure and the solvent's structure by coupling quantum-chemical calculations with three-dimensional (3D) RISM integral equation theory. We compare available DMSO force fields with reference calculations obtained using the polarizable continuum model (PCM). The results are evaluated statistically using two different approaches to eliminating the proton contribution: a linear regression model and an analysis of pK(a) shifts for compound pairs. Suitable levels of theory for the integral equation methodology are benchmarked. The results are further analyzed and illustrated by visualizing solvent site distribution functions and comparing them with an aqueous environment.

  12. Quark compound Bag model for NN scattering up to 1 GeV

    International Nuclear Information System (INIS)

    Fasano, C.; Lee, T.S.H.

    1987-01-01

    A Quark Compound Bag model has been constructed to describe NN s-wave scattering up to 1 GeV. The model contains a vertex interaction H/sub D/leftrightarrow/NN/ for describing the excitation of a confined six-quark Bag state, and a meson-exchange interaction obtained from modifying the phenomenological core of the Paris potential. Explicit formalisms and numerical results are presented to reveal the role of the Bag excitation mechanism in determining the relative wave function, P- and S-matrix of NN scattering. We explore the merit as well as the shortcoming of the Quark Compound Bag model developed by the ITEP group. It is shown that the parameters of the vertex interaction H/sub D/leftrightarrow/NN/ can be more rigorously determined from the data if the notation of the Chiral/Cloudy Bag model is used to allow the presence of the background meson-exchange interaction inside Bag excitation region. The application of the model in the study of quark degrees of freedom in nuclei is discussed. 41 refs., 6 figs., 3 tabs

  13. Linear and nonlinear methods in modeling the aqueous solubility of organic compounds.

    Science.gov (United States)

    Catana, Cornel; Gao, Hua; Orrenius, Christian; Stouten, Pieter F W

    2005-01-01

    Solubility data for 930 diverse compounds have been analyzed using linear Partial Least Square (PLS) and nonlinear PLS methods, Continuum Regression (CR), and Neural Networks (NN). 1D and 2D descriptors from MOE package in combination with E-state or ISIS keys have been used. The best model was obtained using linear PLS for a combination between 22 MOE descriptors and 65 ISIS keys. It has a correlation coefficient (r2) of 0.935 and a root-mean-square error (RMSE) of 0.468 log molar solubility (log S(w)). The model validated on a test set of 177 compounds not included in the training set has r2 0.911 and RMSE 0.475 log S(w). The descriptors were ranked according to their importance, and at the top of the list have been found the 22 MOE descriptors. The CR model produced results as good as PLS, and because of the way in which cross-validation has been done it is expected to be a valuable tool in prediction besides PLS model. The statistics obtained using nonlinear methods did not surpass those got with linear ones. The good statistic obtained for linear PLS and CR recommends these models to be used in prediction when it is difficult or impossible to make experimental measurements, for virtual screening, combinatorial library design, and efficient leads optimization.

  14. Multivariate-parameter optimization of aroma compound release from carbohydrate-oil-protein model emulsions.

    Science.gov (United States)

    Samavati, Vahid; D-jomeh, Zahra Emam

    2013-11-06

    Optimization for retention and partition coefficient of ethyl acetate in emulsion model systems was investigated using response surface methodology in this paper. The effects of emulsion model ingredients, tragacanth gum (TG) (0.5-1 wt%), whey protein isolate (WPI) (2-4 wt%) and oleic acid (5-10%, v/v) on retention and partition coefficient of ethyl acetate were studied using a five-level three-factor central composite rotatable design (CCRD). Results showed that the regression models generated adequately explained the data variation and significantly represented the actual relationships between the independent and response parameters. The results showed that the highest retention (97.20±0.51%) and lowest partition coefficient (4.51±0.13%) of ethyl acetate were reached at the TG concentration 1 wt%, WPI concentration 4 wt% and oleic acid volume fraction 10% (v/v). Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

    International Nuclear Information System (INIS)

    Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

    2016-01-01

    Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H_2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H_2O)]_n (1), [Cd(bzgluO)(2,4′-bipy)_2(H_2O)·3H_2O]_n (2), [Cd(bzgluO)(phen)·H_2O]_n (3), [Cd(bzgluO)(4,4′-bipy)(H_2O)]_n (4), [Cd(bzgluO)(bpp)(H_2O)·2H_2O]_n (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H_2bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H_2bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H_2bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid. • Each complex displays diverse structures and different supramolecular

  16. Simplified fate modelling in respect to ecotoxicological and human toxicological characterisation of emissions of chemical compounds

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, Reinout

    2011-01-01

    The impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. The purpose of the present study is to explore statistical options for reduction...... of the data demand associated with characterisation of chemical emissions in LCIA and ERA.Based on a USEtox™ characterisation factor set consisting of 3,073 data records, multi-dimensional bilinear models for emission compartment specific fate characterisation of chemical emissions were derived by application...... the independent chemical input parameters from the minimum data set, needed for characterisation in USEtox™, according to general availability, importance and relevance for fate factor prediction.Each approach (63% and 75% of the minimum data set needed for characterisation in USEtox™) yielded 66 meta...

  17. Experimental transmission electron microscopy studies and phenomenological model of bismuth-based superconducting compounds

    International Nuclear Information System (INIS)

    Elboussiri, Khalid

    1991-01-01

    The main part of this thesis is devoted to an experimental study by transmission electron microscopy of the different phases of the superconducting bismuth cuprates Bi_2Sr_2Ca_n_-_1Cu_nO_2_n_+_4. In high resolution electron microscopy, the two types of incommensurate modulation realized in these compounds have been observed. A model of structure has been proposed from which the simulated images obtained are consistent with observations. The medium resolution images correlated with the electron diffraction data have revealed existence of a multi-soliton regime with latent lock in phases of commensurate periods between 4b and 10b. At last, a description of different phases of these compounds as a result of superstructures from a disordered perovskite type structure is proposed (author) [fr

  18. Molybdenum (VI) binded to humic and nitrohumic acid models in aqueous solutions salicylic, 3-nitrosalicylic, 5-nitrosalicylic and 3,5 dinitrosalicylic acids, Part 2

    International Nuclear Information System (INIS)

    Merce, Ana Lucia R.; Lopes, Priscilla P.; Mangricha, Antonio S.

    2006-01-01

    In this work electrochemical and Ultraviolet-Visible studies were performed in solutions of salicylic acid models of humic and nitrohumic acids, a laboratory artifact, and molybdenum in order to determine the affinity of these models towards the metal ion. Molybdenum, which plays a very important role in the soil chemistry, and together with humic substances, impart fertility to soil and water and is a key element in the activity of nitrogenase. The obtained results showed that at least one complexed species is present at the pH range of 6.3 to 8.0, even for the less basic chosen models, the nitrosalicylic acids. Previous study showed that phthalic and nitrophthalic, also humic and nitrohumic acids model compounds, presented complexed species with molybdenum only till pH 6.5. The calculated formation constants showed that the substitution of the nitro group in the orto position was less favoured than in the para substitution, probably due to a steric hindrance in the former, which was clearly seen in the double substituted salicylic nitro derivative. The cyclic voltammetry as well as the Ultraviolet-Visible obtained spectra were able to show that the chemistry of molybdenum in aqueous solutions as the pH is increased is very complex, and the molybdate stops acting as an anion only after pH around 4, when it finally becomes a cation MoO 2 2+ (M). (author)

  19. Molybdenum (VI binded to humic and nitrohumic acid models in aqueous solutions. Salicylic, 3-nitrosalicylic, 5-nitrosalicylic and 3,5 dinitrosalicylic acids: part 2

    Directory of Open Access Journals (Sweden)

    Mercê Ana Lucia R.

    2006-01-01

    Full Text Available In this work electrochemical and Ultraviolet-Visible studies were performed in solutions of salicylic acid models of humic and nitrohumic acids, a laboratory artifact, and molybdenum in order to determine the affinity of these models towards the metal ion. Molybdenum, which plays a very important role in the soil chemistry, and together with humic substances, impart fertility to soil and water and is a key element in the activity of nitrogenase. The obtained results showed that at least one complexed species is present at the pH range of 6.3 to 8.0, even for the less basic chosen models, the nitrosalicylic acids. Previous study showed that phthalic and nitrophthalic, also humic and nitrohumic acids model compounds, presented complexed species with molybdenum only till pH 6.5. The calculated formation constants showed that the substitution of the nitro group in the orto position was less favoured than in the para substitution, probably due to a steric hindrance in the former, which was clearly seen in the double substituted salicylic nitro derivative. The cyclic voltammetry as well as the Ultraviolet-Visible obtained spectra were able to show that the chemistry of molybdenum in aqueous solutions as the pH is increased is very complex, and the molybdate stops acting as an anion only after pH around 4, when it finally becomes a cation MoO2(2+ (M.

  20. Solid-phase reduction of silico-12-molybdic acid H4SiMo12O40 by some organic oxygen containing compounds

    International Nuclear Information System (INIS)

    Chuvaev, V.F.; Pinchuk, I.N.; Spitsyn, V.I.

    1982-01-01

    A study is made on reduction reactions of anhydrous silico-12-molybdic acid by vapors of organic oxygen-containing compounds at 170 deg C: alcohols, simple carbonyl compounds. Methods of thermal analysis, electron paramagnetic resonance, paramagnetic resonance were used to established that depending on the nature of organic reagent and temperature, H 6 SiMo 2 5 Mo 10 6 O 40 two-electron or H 8 SiMo 4 5 Mo 8 6 O 40 four-electron flues form. It is shown that the increase of heterogeneous reduction temperature can lead to formation of anhydrous phases of SiMo 12 O 38 -(n/2), able to attach water reversibly with formation of corresponding blue. Characteristics of blues, prepared during solid-phase reduction of silico-12-molybdic acid and mixed valent forms with corresponding reduction degree, separated from water solutions, were compared

  1. Evaluation of the feasibility of the electronic tongue as a rapid analytical tool for wine age prediction and quantification of the organic acids and phenolic compounds. The case-study of Madeira wine

    Energy Technology Data Exchange (ETDEWEB)

    Rudnitskaya, A., E-mail: alisa.rudnitskaya@gmail.com [CESAM/Chemistry Department, University of Aveiro, Aveiro 3810-193 (Portugal); Chemistry Department, St. Petersburg University, St. Petersburg 199034 (Russian Federation); Rocha, S.M. [Chemistry Department, University of Aveiro, Aveiro 3810-193 (Portugal); Legin, A. [Chemistry Department, St. Petersburg University, St. Petersburg 199034 (Russian Federation); Pereira, V.; Marques, J.C. [Madeira Chemistry Center, University of Madeira, Funchal 9000-390 (Portugal)

    2010-03-03

    A set of fourteen Madeira wines comprising wines produced from four Vitis vinifera L. varieties (Bual, Malvasia, Verdelho and Tinta Negra Mole) that were 3, 6, 10 and 17 years old was analysed using HPLC and an electronic tongue (ET) multisensor system. Concentrations of 24 organic acids, phenolic and furanic compounds were determined by HPLC. The ET consisting of 26 potentiometric chemical sensors with plasticized PVC and chalcogenide glass membranes was used. Significance of the effects of age and variety on the ET response and wine composition with respect to the organic acids, phenolics and furanic derivatives were evaluated using ANOVA-Simultaneous Component Analysis (ASCA). Significance of the effects was estimated using a permutation test (1000 permutations). It was found that effects of age, grape variety and their interaction were significant for the HPLC data set and only the effect of age was significant for the ET data. Calibration models of the HPLC and ET data with respect to the wine age and of the ET data with respect to the concentration of the organic acids and phenolics were calculated using PLS1 regression. Models were validated using cross-validation. It was possible to predict wine age from HPLC and ET data with the accuracy in cross-validation of 2.6 and 1.8 years respectively. The ET was capable of detecting the following components (mean relative error in cross-validation is shown in the parentheses): tartaric (8%), citric (5%), formic (12%), protocatehuic (5%), vanillic (18%) and sinapic (14%) acids, catechin (6%), vanillin (12%) and trans-resveratrol (5%). The ET capability of predicting Madeira wine age with good accuracy (1.8 years) as well as quantify of some organic acids and phenolic compounds was demonstrated.

  2. Evaluation of the feasibility of the electronic tongue as a rapid analytical tool for wine age prediction and quantification of the organic acids and phenolic compounds. The case-study of Madeira wine

    International Nuclear Information System (INIS)

    Rudnitskaya, A.; Rocha, S.M.; Legin, A.; Pereira, V.; Marques, J.C.

    2010-01-01

    A set of fourteen Madeira wines comprising wines produced from four Vitis vinifera L. varieties (Bual, Malvasia, Verdelho and Tinta Negra Mole) that were 3, 6, 10 and 17 years old was analysed using HPLC and an electronic tongue (ET) multisensor system. Concentrations of 24 organic acids, phenolic and furanic compounds were determined by HPLC. The ET consisting of 26 potentiometric chemical sensors with plasticized PVC and chalcogenide glass membranes was used. Significance of the effects of age and variety on the ET response and wine composition with respect to the organic acids, phenolics and furanic derivatives were evaluated using ANOVA-Simultaneous Component Analysis (ASCA). Significance of the effects was estimated using a permutation test (1000 permutations). It was found that effects of age, grape variety and their interaction were significant for the HPLC data set and only the effect of age was significant for the ET data. Calibration models of the HPLC and ET data with respect to the wine age and of the ET data with respect to the concentration of the organic acids and phenolics were calculated using PLS1 regression. Models were validated using cross-validation. It was possible to predict wine age from HPLC and ET data with the accuracy in cross-validation of 2.6 and 1.8 years respectively. The ET was capable of detecting the following components (mean relative error in cross-validation is shown in the parentheses): tartaric (8%), citric (5%), formic (12%), protocatehuic (5%), vanillic (18%) and sinapic (14%) acids, catechin (6%), vanillin (12%) and trans-resveratrol (5%). The ET capability of predicting Madeira wine age with good accuracy (1.8 years) as well as quantify of some organic acids and phenolic compounds was demonstrated.

  3. Thermal Decomposition Mechanisms of Lignin Model Compounds: From Phenol to Vanillin

    Science.gov (United States)

    Scheer, Adam Michael

    Lignin is a complex, aromatic polymer abundant in cellulosic biomass (trees, switchgrass etc.). Thermochemical breakdown of lignin for liquid fuel production results in undesirable polycyclic aromatic hydrocarbons that lead to tar and soot byproducts. The fundamental chemistry governing these processes is not well understood. We have studied the unimolecular thermal decomposition mechanisms of aromatic lignin model compounds using a miniature SiC tubular reactor. Products are detected and characterized using time-of-flight mass spectrometry with both single photon (118.2 nm; 10.487 eV) and 1 + 1 resonance-enhanced multiphoton ionization (REMPI) as well as matrix isolation infrared spectroscopy. Gas exiting the heated reactor (300 K--1600 K) is subject to a free expansion after a residence time of approximately 100 micros. The expansion into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. By understanding the unimolecular fragmentation patterns of phenol (C6H5OH), anisole (C6H 5OCH3) and benzaldehyde (C6H5CHO), the more complicated thermocracking processes of the catechols (HO-C 6H4-OH), methoxyphenols (HO-C6H4-OCH 3) and hydroxybenzaldehydes (HO-C6H4-CHO) can be interpreted. These studies have resulted in a predictive model that allows the interpretation of vanillin, a complex phenolic ether containing methoxy, hydroxy and aldehyde functional groups. This model will serve as a guide for the pyrolyses of larger systems including lignin monomers such as coniferyl alcohol. The pyrolysis mechanisms of the dimethoxybenzenes (H3C-C 6H4-OCH3) and syringol, a hydroxydimethoxybenzene have also been studied. These results will aid in the understanding of the thermal fragmentation of sinapyl alcohol, the most complex lignin monomer. In addition to the model compound work, pyrolyisis of biomass has been studied via the pulsed laser ablation of poplar wood. With the REMPI scheme, aromatic lignin decomposition

  4. Analysis of the isobaric compounds propanol, acetic acid and methyl formate in humid air and breath by selected ion flow tube mass spectrometry, SIFT-MS

    Czech Academy of Sciences Publication Activity Database

    Pysanenko, A.; Španěl, Patrik; Smith, D.

    2009-01-01

    Roč. 285, 1-2 (2009), s. 42-48 ISSN 1387-3806 R&D Projects: GA ČR GA203/09/0256; GA ČR GA202/09/0800 Institutional research plan: CEZ:AV0Z40400503 Keywords : SIFT-MS * isobaric compound * propanol * acetic acid Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.117, year: 2009

  5. Transition metal-free oxidation of benzylic alcohols to carbonyl compounds by hydrogen peroxide in the presence of acidic silica gel

    Directory of Open Access Journals (Sweden)

    Hossein Ghafuri

    2015-01-01

    Full Text Available Oxidation of alcohols to carbonyl compounds has become an important issue in the process industry as well as many other applications. In this method, various benzylic alcohols were successfully converted to corresponding aldehydes and ketones under transition metal-free condition using hydrogen peroxide in the presence of some amount of catalytic acidic silica gel. Silica gel is inexpensive and available. One of the most important features of this method is its short reaction time.

  6. Experimental and kinetic modelling studies on the acid-catalysed hydrolysis of the water hyacinth plant to levulinic acid

    NARCIS (Netherlands)

    Girisuta, B.; Danon, B.; Manurung, R.; Janssen, L. P. B. M.; Heeres, H. J.

    2008-01-01

    A comprehensive experimental and modelling study on the acid-catalysed hydrolysis of the water hyacinth plant (Eichhornia crassipes) to optimise the yield of levulinic acid (LA) is reported (T = 150-175 degrees C, C-H2SO4 - 0.1-1 M, water hyacinth intake = 1-5 wt%). At high acid concentrations (>

  7. Effects of NaCl and soaking temperature on the phenolic compounds, α-tocopherol, γ-oryzanol and fatty acids of glutinous rice.

    Science.gov (United States)

    Thammapat, Pornpisanu; Meeso, Naret; Siriamornpun, Sirithon

    2015-05-15

    Soaking is one of the important steps of the parboiling process. In this study, we investigated the effect of changes in different sodium chloride (NaCl) content (0%, 1.5% and 3.0% NaCl, w/v) of soaking media and soaking temperatures (30°C, 45°C and 60°C) on the phenolic compounds (α-tocopherol, γ-oryzanol) and on the fatty acids of glutinous rice, compared with unsoaked samples. Overall, the total phenolic content, total phenolic acids, γ-oryzanol, saturated fatty acid and mono-unsaturated fatty acid of the glutinous rice showed an increasing trend as NaCl content and soaking temperature increased, while α-tocopherol and polyunsaturated fatty acids decreased. Soaking at 3.0% NaCl provided the highest total phenolic content, total phenolic acids and γ-oryzanol (0.2mg GAE/g, 63.61 μg/g and 139.76 mg/100g, respectively) for the soaking treatments tested. Nevertheless, the amount of α-tocopherol and polyunsaturated fatty acid were found to be the highest (18.30/100g and 39.74%, respectively) in unsoaked rice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Direct Synthesis of 5-Aryl Barbituric Acids by Rhodium(II)-Catalyzed Reactions of Arenes with Diazo Compounds**

    Science.gov (United States)

    Best, Daniel; Burns, David J; Lam, Hon Wai

    2015-01-01

    A commercially available rhodium(II) complex catalyzes the direct arylation of 5-diazobarbituric acids with arenes, allowing straightforward access to 5-aryl barbituric acids. Free N—H groups are tolerated on the barbituric acid, with no complications arising from N—H insertion processes. This method was applied to the concise synthesis of a potent matrix metalloproteinase (MMP) inhibitor. PMID:25959544

  9. [Separation of gamma linolenic acid from evening primrose oil with urea inclusion--orthogonal experiment of optimizing technological parameters and observation of urea inclusion compound I].

    Science.gov (United States)

    Wang, Hua; Ling, Man; Xue, Gang; Liu, Fengxia; Guo, Shuxian

    2010-05-01

    The influence on the urea inclusion compound under different conditions (allocated proportion, time of inclusion, temperature of inclusion) were studied through the orthogonal test, and theoretical reference of urea inclusion process for further optimization wound be offered. The orthogonal experiment was adopted, and microscope was used to observe the shape, aperture size of the urea inclusion compound under different technological parameters, the GC was employed to inspect the purity of GLA. The results indicated that the ratio of fatty acids and urea, inclusion of temperature, time of inclusion had great effect on urea inclusion compound. The three factors and its interactions significantly affected the purity of GLA. The results also showed that the best process was that the ratio of fatty acids and urea was 1 : 3, temperature of inclusion was--15 degrees C, time of inclusion was 24 h. Under the best condition, the purity of GLA reach up to 95.575 9%; and it is feasible to observe the shape and the amount of the urea inclusion compound to reflect and guide the urea inclusion technology.

  10. Metabotyping of docosahexaenoic acid - treated Alzheimer's disease cell model.

    Directory of Open Access Journals (Sweden)

    Priti Bahety

    Full Text Available BACKGROUND: Despite the significant amount of work being carried out to investigate the therapeutic potential of docosahexaenoic acid (DHA in Alzheimer's disease (AD, the mechanism by which DHA affects amyloid-β precursor protein (AβPP-induced metabolic changes has not been studied. OBJECTIVE: To elucidate the metabolic phenotypes (metabotypes associated with DHA therapy via metabonomic profiling of an AD cell model using gas chromatography time-of-flight mass spectrometry (GC/TOFMS. METHODS: The lysate and supernatant samples of CHO-wt and CHO-AβPP695 cells treated with DHA and vehicle control were collected and prepared for GC/TOFMS metabonomics profiling. The metabolic profiles were analyzed by multivariate data analysis techniques using SIMCA-P+ software. RESULTS: Both principal component analysis and subsequent partial least squares discriminant analysis revealed distinct metabolites associated with the DHA-treated and control groups. A list of statistically significant marker metabolites that characterized the metabotypes associated with DHA treatment was further identified. Increased levels of succinic acid, citric acid, malic acid and glycine and decreased levels of zymosterol, cholestadiene and arachidonic acid correlated with DHA treatment effect. DHA levels were also found to be increased upon treatment. CONCLUSION: Our study shows that DHA plays a role in mitigating AβPP-induced impairment in energy metabolism and inflammation by acting on tricarboxylic acid cycle, cholesterol biosynthesis pathway and fatty acid metabolism. The perturbations of these metabolic pathways by DHA in CHO-wt and CHO-AβPP695 cells shed further mechanistic insights on its neuroprotective actions.

  11. Kinetic modeling of formic acid pulping of bagasse.

    Science.gov (United States)

    Tu, Qiliang; Fu, Shiyu; Zhan, Huaiyu; Chai, Xinsheng; Lucia, Lucian A

    2008-05-14

    Organic solvent or organosolv pulping processes are alternatives to soda or kraft pulping to delignify lignocellulosic materials for the production of paper pulp. Formic acid, a typical organosolv system, has been presently examined under atmospheric pressure to pulp bagasse fibers. It was shown that efficient bagasse pulping was achieved when the formic acid concentration was limited to 90% (v/v). A statistical kinetic model based on the experimental results for the delignification of bagasse during formic acid pulping was developed that can be described as follows: D (delignification) = 0.747 x C(formicacid) (1.688) x (1 - e(-0.05171t)), an equation that can be used to predict the lignin content in formic acid during the pulping process. The delignification of bagasse by 90% formic acid was almost completed after approximately 80 min, while extended pulping did not improve the delignification but tended to degrade the carbohydrates in bagasse, especially the hemicelluloses, which were rapidly hydrolyzed at the onset of pulping.

  12. Mouse models: the ketogenic diet and polyunsaturated fatty acids.

    Science.gov (United States)

    Borges, Karin

    2008-11-01

    Literature on the anticonvulsant effects of the ketogenic diet (KD) in mouse seizure models is summarized. Recent data show that a KD balanced in vitamin, mineral, and antioxidant content is anticonvulsant in mice, confirming that the KD's effect in mice can be attributed to the composition of the diet and not other dietary factors. Given that the anticonvulsant mechanism of the KD is still unknown, the anticonvulsant profile of the diet in different seizure models may help to decipher this mechanism. The implications of the findings that the KD is anticonvulsant in electrical seizure models are indicated. Further, the potential involvement of polyunsaturated fatty acids (PUFA) in the KD's anticonvulsant mechanism is discussed.

  13. Model for fusion and cool compound nucleus formation based on the fragmentation theory

    International Nuclear Information System (INIS)

    Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.

    1986-01-01

    Collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two-center shell model in the Strutinsky method. It is shown that fusion of two colliding heavy ions occurs by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers, whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determines whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Coulomb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102 < or =Z < or =114

  14. Model for fusion and cool compound nucleus formation based on the fragmentation theory

    International Nuclear Information System (INIS)

    Malhotra, N.; Aroumougame, R.; Saroha, D.R.; Gupta, R.K.

    1985-07-01

    The collective potential energy surfaces are calculated in both the adiabatic and sudden approximations by using the asymmetric two centre shell model in Strutinsky method. It is shown that fusion of two colliding heavy ions occur by their crossing over of the adiabatic interaction barrier. The adiabatic scattering potentials present two barriers whereas no barrier is shown to occur in sudden scattering potentials. The first barrier is obtained just past the saddle shape but is too low, such that a deep inelastic process is expected. The other, inner, barrier is high enough to let the system fall into the fusion well, whose excitation energy then determine whether a cool compound nucleus is produced or the fusion-fission process occurs. For a given compound nucleus, the excitation energy is found to be small for only a few target-projectile combinations, which increase as their mass asymmetry increases. Such target-projectile combinations which refer to a cool compound nucleus, can be identified by a simple calculation of the fragmentation potential based on the ground state binding energies with Couloumb and proximity effects calculated at a constant relative separation of the two nuclei. Our calculations are made for the composite systems with 102<=Z<=114. (author)

  15. Compound toxicity screening and structure-activity relationship modeling in Escherichia coli.

    Science.gov (United States)

    Planson, Anne-Gaëlle; Carbonell, Pablo; Paillard, Elodie; Pollet, Nicolas; Faulon, Jean-Loup

    2012-03-01

    Synthetic biology and metabolic engineering are used to develop new strategies for producing valuable compounds ranging from therapeutics to biofuels in engineered microorganisms. When developing methods for high-titer production cells, toxicity is an important element to consider. Indeed the production rate can be limited due to toxic intermediates or accumulation of byproducts of the heterologous biosynthetic pathway of interest. Conversely, highly toxic molecules are desired when designing antimicrobials. Compound toxicity in bacteria plays a major role in metabolic engineering as well as in the development of new antibacterial agents. Here, we screened a diversified chemical library of 166 compounds for toxicity in Escherichia coli. The dataset was built using a clustering algorithm maximizing the chemical diversity in the library. The resulting assay data was used to develop a toxicity predictor that we used to assess the toxicity of metabolites throughout the metabolome. This new tool for predicting toxicity can thus be used for fine-tuning heterologous expression and can be integrated in a computational-framework for metabolic pathway design. Many structure-activity relationship tools have been developed for toxicology studies in eukaryotes [Valerio (2009), Toxicol Appl Pharmacol, 241(3): 356-370], however, to the best of our knowledge we present here the first E. coli toxicity prediction web server based on QSAR models (EcoliTox server: http://www.issb.genopole.fr/∼faulon/EcoliTox.php). Copyright © 2011 Wiley Periodicals, Inc.

  16. The dynamics of acid-soluble phosphorus compounds in the course of winter and spring wheat germination under various thermic conditions. Part II. Labile phosphorus after hydrolysis of the acid-soluble fraction

    Directory of Open Access Journals (Sweden)

    A. Barbaro

    2015-06-01

    Full Text Available The changes in labile phosphorus compounds content during germination of wheat were investigated. These compounds were determined in acid-soluble germ extracts separated into fractions according to the solubility of their barium salts. Low germination temperature was found to raise the labile phosphorus content in the fraction of insoluble barium salts. If we assume that labile P of this fraction consisted mainly of adenosinedi- and triphosphates, it would seem that the rise, in the ATP and ADP level under the influence of low temperature may be essential for initiating flowering in winter varieties.

  17. Nucleon-nucleon interaction in the quark-compound-bag model

    International Nuclear Information System (INIS)

    Simonov, Yu.A.

    1982-01-01

    The NN potential is investigated in the framework of the quark-compound-bag model. The cluster decomposition of the total six-quark wave function are obtained. The resulting potential is nonlocal and energy dependent with coefficients which can be derived both phenomenologically and theoretically. Stringent conditions exist for those coefficients. As an example the NN potentials for the 3 S 1 and 1 S 0 states are presented. The properties of the wave functions are studied both in the configurational and momentum space

  18. Quest for consistent modelling of statistical decay of the compound nucleus

    Science.gov (United States)

    Banerjee, Tathagata; Nath, S.; Pal, Santanu

    2018-01-01

    A statistical model description of heavy ion induced fusion-fission reactions is presented where shell effects, collective enhancement of level density, tilting away effect of compound nuclear spin and dissipation are included. It is shown that the inclusion of all these effects provides a consistent picture of fission where fission hindrance is required to explain the experimental values of both pre-scission neutron multiplicities and evaporation residue cross-sections in contrast to some of the earlier works where a fission hindrance is required for pre-scission neutrons but a fission enhancement for evaporation residue cross-sections.

  19. Repair of model compounds of photoinduced lesions in DNA. Electrochemical approaches

    International Nuclear Information System (INIS)

    Boussicault, F.

    2006-09-01

    The goal of this work is to better understand the repair mechanism of photoinduced lesions in DNA (cyclobutane dimers and pyrimidine (6-4) pyrimidone adducts) by photolyase redox enzymes, using tools and concepts of molecular electrochemistry. Thanks to the study of model compounds of cyclobutane lesions by cyclic voltametry, we have been able to mimic the key step of the enzymatic repair (dissociative electron transfer) and to monitor the repair of model compounds by Escherichia coli DNA photolyase. From these results, we have discussed the repair mechanism, especially the stepwise or concerted character of the process. Repair mechanism of (6-4) adducts is not known now, but a possible pathway implies an electron transfer coupled to the cleavage of two bonds in the closed form of the lesions (oxetanes). Voltammetric study of reduction and oxidation of model oxetanes and their repair by E. coli DNA photolyase gave some experimental evidence confirming the proposed mechanism and allowing a better understanding of it. (author)

  20. Effect of Selected Mercapto Flavor Compounds on Acrylamide Elimination in a Model System

    Directory of Open Access Journals (Sweden)

    Zhiyong Xiong

    2017-05-01

    Full Text Available The effect of four mercapto flavor compounds (1,2-ethanedithiol, 1-butanethiol, 2-methyl-3-furanthiol, and 2-furanmethanethiol on acrylamide elimination were investigated in model systems. The obtained results showed that mercaptans assayed were effective in elimination arylamide in a model system. Their reactivities for decreasing acrylamide content depended on mercaptan’s molecular structure and acrylamide disappearance decreased in the following order: 1,2-ethanedithiol > 2-methyl-3-furanthiol > 1-butanethiol > 2-furanmethanethiol. Mercaptans were added to acrylamide to produce the corresponding 3-(alkylthio propionamides. This reaction was irreversible and only trace amounts of acrylamide were formed by thermal heating of 3-(alkylthio propanamide. Although a large amount disappeared, only part of the acrylamide conversed into 3-(alkylthio propionamides. All of these results constitute a fundamental proof of the complexity of the reactions involved in the removal of free acrylamide in foods. This implies mercapto flavor/aroma may directly or indirectly reduce the level of acrylamide in food processing. This study could be regarded as a pioneer contribution on acrylamide elimination in a model system by the addition of mercapto flavor compounds.

  1. Modeling molecular acidity with electronic properties and Hammett constants for substituted benzoic acids.

    Science.gov (United States)

    Huang, Ying; Liu, Lianghong; Liu, Wanhui; Liu, Shaogang; Liu, Shubin

    2011-12-29

    Molecular acidity is an important physiochemical property essential in many fields of molecular studies, but an efficient and reliable computational approach to make accurate predictions is still missing. In this work, based on our previous studies to use gas phase electronic properties such as molecular electrostatic potential and valence natural atomic orbitals of the acidic atom and leaving proton, we demonstrate here that different approaches can be employed to tackle this problem. To that end, we employ 196 singly, doubly, and triply substituted benzoic acids for the study. We show that two different approaches are possible, one focusing on the carboxyl group through its localized electronic properties and the other on the substituting groups via Hammett constants and their additivity rule. Our present results clearly exhibit that with the linear models built from the singly substituted species, one can accurately predict the pK(a) values for the doubly and triply substituted species with both of these two approaches. The predictions from these approaches are consistent with each other and agree well with the experimental data. These intrinsically different approaches are the two manifestations of the same molecular acidity property, both valid and complementary to each other. © 2011 American Chemical Society

  2. Mechanism of nitric acid reduction and kinetic modelling

    International Nuclear Information System (INIS)

    Sicsic, David; Balbaud-Celerier, Fanny; Tribollet, Bernard

    2014-01-01

    In France, the recycling of nuclear waste fuels involves the use of hot concentrated nitric acid. The understanding and prediction of the behaviour of the structural materials (mainly austenitic stainless steels) requires the determination and modelling of the nitric acid reduction process. Nitric acid is indirectly reduced by an autocatalytic mechanism depending on the cathodic overpotential and acid concentration. This mechanism has been widely studied. All the authors agree on its autocatalytic nature, characterized by the predominant role of the reduction products. It is also generally admitted that neither nitric acid nor the nitrate ion is the electro-active species. However, the nature of the electro-active species, the place where the catalytic species regenerates and the thermodynamic and kinetic behaviour of the reaction intermediates remain uncertain. The aim of this study was to clarify some of these uncertainties by performing an electrochemical investigation of the reduction of 4 M nitric acid at 40 C at an inert electrode (platinum or gold). An inert electrode was chosen as the working electrode in a first step to avoid its oxidation and focus the research on the reduction mechanism. This experimental work enabled us to suggest a coherent sequence of electrochemical and chemical reactions. Kinetic modelling of this sequence was then carried out for a gold rotating disk electrode. A thermodynamic study at 25 C allowed the composition of the liquid and gaseous phases of nitric acid solutions in the concentration range 0.5-22 M to be evaluated. The kinetics of the reduction of 4 M nitric acid was investigated by cyclic voltammetry and chrono-amperometry at an inert electrode at 40 C. The coupling of chrono-amperometry and FTIR spectroscopy in the gaseous phase led to the identification of the gaseous reduction products as a function of the cathodic overpotential. The results showed that the reduction process is autocatalytic for potentials between 0

  3. Activity Prediction of Schiff Base Compounds using Improved QSAR Models of Cinnamaldehyde Analogues and Derivatives

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2015-10-01

    Full Text Available In past work, QSAR (quantitative structure-activity relationship models of cinnamaldehyde analogues and derivatives (CADs have been used to predict the activities of new chemicals based on their mass concentrations, but these approaches are not without shortcomings. Therefore, molar concentrations were used instead of mass concentrations to determine antifungal activity. New QSAR models of CADs against Aspergillus niger and Penicillium citrinum were established, and the molecular design of new CADs was performed. The antifungal properties of the designed CADs were tested, and the experimental Log AR values were in agreement with the predicted Log AR values. The results indicate that the improved QSAR models are more reliable and can be effectively used for CADs molecular design and prediction of the activity of CADs. These findings provide new insight into the development and utilization of cinnamaldehyde compounds.

  4. Predictive QSPR Modelling for the Second Virial Coefficient of the Pure Organic Compounds.

    Science.gov (United States)

    Mokshyna, E; Polishchuk, P G; Nedostup, V I; Kuzmin, V E

    2015-01-01

    In this article we developed a system of the predictive models for the second virial coefficients of the pure compounds. Second virial coefficient is the property derived from the virial equation of state, and is of particular interest as it describes pair intermolecular interactions. The two-layer QSPR models were developed, which exploited the well-known physical equations and allowed us to include this information into traditional QSPR methodology. This shows some new perspectives for work with temperature-dependent properties. It was shown that 2D descriptors can be successfully used for modeling of complex thermodynamic properties like virial coefficients. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Alternative host models for Testing Anti-Protozoal or Antifungal Compounds and fungal infection.

    Science.gov (United States)

    Torrecilhas, Ana Claudia; Xander, Patricia; Ferreira, Karen Spadari; Batista, Wagner Luiz

    2018-04-12

    The neglected tropical diseases (NTDs) are caused by several parasites, fungi, bacteria and viruses and affect more than one billion people in the world. The control and prevention against NTDs need implementation of alternative methods for testing new compounds against these diseases. For the implementation of alternative methods, it is necessary to apply the principles of replacement, reduction and refinement (the 3Rs) for the use of laboratory animals. Accordingly, the present review addressed a variety of alternative models to study the infections caused by protozoa and fungi. Overall, vertebrate and invertebrate models of fungal infection have been used to elucidate hostpathogen interactions. However, until now the insect model has not been used in protozoal studies as an alternative method, but there is interest in the scientific community to try new tools to screen alternative drugs to control and prevent protozoal infections. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. New compounds from acid hydrolyzed products of the fruits of Momordica charantia L. and their inhibitory activity against protein tyrosine phosphatas 1B.

    Science.gov (United States)

    Zeng, Ke; He, Yan-Ni; Yang, Di; Cao, Jia-Qing; Xia, Xi-Chun; Zhang, Shi-Jun; Bi, Xiu-Li; Zhao, Yu-Qing

    2014-06-23

    Four new cucurbitane-type triterpene sapogenins, compounds 1-4, together with other eight known compounds were isolated from the acid-hydrolyzed fruits extract of Momordica charantia L. Their chemical structures were established by NMR, mass spectrometry and X-ray crystallography. Compounds 1-7 and 9-12 were evaluated for their inhibitory activities toward protein tyrosine phosphatase 1B (PTP1B), a tyrosine phosphatase that has been implicated as a key target for therapy against type II diabetes. Compounds 1, 2, 4, 7 and 9 were shown inhibitory activities of 77%, 62%, 62% 60% and 68% against PTP1B, respectively. All of these tested compounds were exhibited higher PTP1B inhibition activities than that of the Na3VO4, a known PTP1B inhibitor used as positive control in present study. Structure activity relationship (SAR) analysis indicated that the inhibition activity of PTP1B was associated with the presence and number of -OH groups. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Antisera to gamma-aminobutyric acid. I. Production and characterization using a new model system.

    Science.gov (United States)

    Hodgson, A J; Penke, B; Erdei, A; Chubb, I W; Somogyi, P

    1985-03-01

    Antisera to the amino acid gamma-aminobutyric acid (GABA) have been developed with the aim of immunohistochemical visualization of neurons that use it as a neurotransmitter. GABA bound to bovine serum albumin was the immunogen. The reactivities of the sera to GABA and a variety of structurally related compounds were tested by coupling these compounds to nitrocellulose paper activated with polylysine and glutaraldehyde and incubating the paper with the unlabeled antibody enzyme method, thus simulating immunohistochemistry of tissue sections. The antisera did not react with L-glutamate, L-aspartate, D-aspartate, glycine, taurine, L-glutamine, L-lysine, L-threonine, L-alanine, alpha-aminobutyrate, beta-aminobutyrate, putrescine, or delta-aminolevulinate. There was cross-reaction with gamma-amino-beta-hydroxybutyrate, 1-10%, and the homologues of GABA: beta-alanine, 1-10%, delta-aminovalerate, approximately 10%, and epsilon-amino-caproate, approximately 10%. The antisera reacted slightly with the dipeptide gamma-aminobutyrylleucine, but not carnosine or homocarnosine. Immunostaining of GABA was completely abolished by adsorption of the sera to GABA coupled to polyacrylamide beads by glutaraldehyde. The immunohistochemical model is simple, amino acids and peptides are bound in the same way as in aldehyde-fixed tissue and, in contrast to radioimmunoassay, it uses an immunohistochemical detection system. This method has enabled us to define the high specificity of anti-GABA sera and to use them in some novel ways. The model should prove useful in assessing the specificity of other antisera.

  8. Comparison of receptor models for source apportionment of volatile organic compounds in Beijing, China

    International Nuclear Information System (INIS)

    Song Yu; Dai Wei; Shao Min; Liu Ying; Lu Sihua; Kuster, William; Goldan, Paul

    2008-01-01

    Identifying the sources of volatile organic compounds (VOCs) is key to reducing ground-level ozone and secondary organic aerosols (SOAs). Several receptor models have been developed to apportion sources, but an intercomparison of these models had not been performed for VOCs in China. In the present study, we compared VOC sources based on chemical mass balance (CMB), UNMIX, and positive matrix factorization (PMF) models. Gasoline-related sources, petrochemical production, and liquefied petroleum gas (LPG) were identified by all three models as the major contributors, with UNMIX and PMF producing quite similar results. The contributions of gasoline-related sources and LPG estimated by the CMB model were higher, and petrochemical emissions were lower than in the UNMIX and PMF results, possibly because the VOC profiles used in the CMB model were for fresh emissions and the profiles extracted from ambient measurements by the two-factor analysis models were 'aged'. - VOCs sources were similar for three models with CMB showing a higher estimate for vehicles

  9. Comparison of receptor models for source apportionment of volatile organic compounds in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Song Yu; Dai Wei [Department of Environmental Sciences, Peking University, Beijing 100871 (China); Shao Min [State Joint Key Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871 (China)], E-mail: mshao@pku.edu.cn; Liu Ying; Lu Sihua [State Joint Key Laboratory of Environmental Simulation and Pollution Control, Peking University, Beijing 100871 (China); Kuster, William; Goldan, Paul [Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO 80305 (United States)

    2008-11-15

    Identifying the sources of volatile organic compounds (VOCs) is key to reducing ground-level ozone and secondary organic aerosols (SOAs). Several receptor models have been developed to apportion sources, but an intercomparison of these models had not been performed for VOCs in China. In the present study, we compared VOC sources based on chemical mass balance (CMB), UNMIX, and positive matrix factorization (PMF) models. Gasoline-related sources, petrochemical production, and liquefied petroleum gas (LPG) were identified by all three models as the major contributors, with UNMIX and PMF producing quite similar results. The contributions of gasoline-related sources and LPG estimated by the CMB model were higher, and petrochemical emissions were lower than in the UNMIX and PMF results, possibly because the VOC profiles used in the CMB model were for fresh emissions and the profiles extracted from ambient measurements by the two-factor analysis models were 'aged'. - VOCs sources were similar for three models with CMB showing a higher estimate for vehicles.

  10. Synthesis and Odor Evaluation of Five New Sulfur-Containing Ester Flavor Compounds from 4-Ethyloctanoic Acid

    Directory of Open Access Journals (Sweden)

    Baoguo Sun

    2010-07-01

    Full Text Available Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthiopropyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

  11. Synthesis and odor evaluation of five new sulfur-containing ester flavor compounds from 4-ethyloctanoic acid.

    Science.gov (United States)

    Liu, Yuping; Chen, Haitao; Yin, Decai; Sun, Baoguo

    2010-07-29

    Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthio)propyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

  12. Electrospray ionization mass spectrometric investigations of [alpha]-dicarbonyl compounds--Probing intermediates formed in the course of the nonenzymatic browning reaction of l-ascorbic acid

    Science.gov (United States)

    Schulz, Anke; Trage, Claudia; Schwarz, Helmut; Kroh, Lothar W.

    2007-05-01

    A new method is presented which allows the simultaneous detection of various [alpha]-dicarbonyl compounds generated in the course of the nonenzymatic browning reaction initiated by thermal treatment of l-ascorbic acid, namely: glyoxal, methylglyoxal, diacetyl, 3-deoxy-l-pentosone, and l-threosoneE 3-Deoxy-l-threosone was successfully identified as a new C4-[alpha]-dicarbonyl structure for the first time in the degradation of Vitamin C by application of this non-chromatographic mass spectrometric approach. Moreover, a more detailed elucidation of the mechanistic scenario with respect to the oxidative and nonoxidative pathways is presented by using dehydro-l-ascorbic acid and 2,3-diketo-l-gulonic acid instead of l-ascorbic acid as a starting material. Furthermore, the postulated pathways are corroborated with the aid of 13C-isotopic labeling studies. The investigations were extended to baby food, and the successful detection of [alpha]-dicarbonyl compounds characteristic for Vitamin C degradation proved the matrix tolerance of the introduced method.

  13. Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

    Science.gov (United States)

    Lee, M T; Ahmed, T; Friedman, M E

    1989-01-01

    Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

  14. Postglacial climate reconstruction based on compound-specific D/H ratios of fatty acids from Blood Pond, New England

    Science.gov (United States)

    Hou, Juzhi; Huang, Yongsong; Wang, Yi; Shuman, Bryan; Oswald, W. Wyatt; Faison, Edward; Foster, David R.

    2006-03-01

    We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood Pond, Massachusetts, USA, in order to reconstruct climate changes during the past 15 kyr. In addition to palmitic acid (C16n-acid), which has been shown to record lake water D/H ratios, our surface sediments and down core data indicate that behenic acid (C22n-acid), produced mainly by aquatic macrophytes, is also effective for capturing past environmental change. Calibration using surface sediments from two transects across eastern North America indicates that behenic acid records δD variation of lake water. Down core variations in δD values of behenic acid and pollen taxa are consistent with the known climate change history of New England. By evaluating the hypothesis that D/H fractionations of long chain even numbered fatty acids (C24-C32n-acids) relative to lake water provide independent estimates of relative humidity during the growing season, we find that differences between lake-level records and isotopically inferred humidity estimates may provide useful insight into seasonal aspects of the hydrologic cycle. Combined analyses of D/H of short and long chain fatty acids from lake sediment cores thus allow reconstructions of both past temperature and growing season relative humidity. Comparison of δD records from two lakes in New England provides critical information on regional climate variation and abrupt climate change, such as the 8.2 ka event.

  15. Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

    Science.gov (United States)

    Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

    2016-01-01

    Five new Cd(II) coordination p