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Sample records for acides amines du

  1. Extraction of some acids using aliphatic amines; Extraction de quelques acides par des amines aliphatiques

    Energy Technology Data Exchange (ETDEWEB)

    Matutano, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-06-01

    Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [French] Les acides chlorhydrique, nitrique, sulfurique, perchlorique, phosphorique, acetique et formique, en solution aqueuse - 0,05 a 10 M - sont extraits par l'amberlite LA2 et la trilaurylamine en solution, a 5 pour cent en volume, dans le kerosene et le xylene respectivement. L'extraction comprend: une neutralisation de l'amine par l'acide avec formation d'un sel d'amine; une 'extraction moleculaire', c'est-a-dire une extraction d'acide en exces par rapport a la stoechiometrie du sel d'amine. Suivant le comportement des acides au cours de l'extraction nous distinguons trois groupes: acides entierement dissocies, acides carboxyliques, acide phosphorique. Cette classification est egalement valable pour l'extraction de l'eau qui est simultanee a celle de l'acide. Un mecanisme d'extraction pour l'acide formique est propose et nous calculons la constante de formation de son sel d'amine. (auteur)

  2. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E S [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  3. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E.S. [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  4. Extraction of some acids using aliphatic amines

    International Nuclear Information System (INIS)

    Matutano, L.

    1964-06-01

    Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [fr

  5. Amine reactivity with charged sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    B. R. Bzdek

    2011-08-01

    Full Text Available The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4(H2SO4x] and [(NH4x(HSO4x+1(H2SO43]. Dimethylamine substitution for ammonia in [(NH4 x(HSO4 x+1(H2SO43] clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4 (H2SO4 x] clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition

  6. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts. (a... a fatty acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject to reporting...

  7. Extraction and purification of plutonium by a tertiary amine; Extraction et purification du plutonium par une amine tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Trentinian, M de; Chesne, A [Commissariat a l' Energie Atomique, Fontenay aux Roses, Section de Chimie des Actimides (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Trilaurylamine diluted with a paraffinic solvent (dodecane) was studied as part of the research dealing with the separation and purification of plutonium. The physical properties (solubility of nitrates in the amine as a function of temperature) and the resistance to radiations of this substance were examined. The extraction characteristics of nitric solutions of plutonium, uranium and certain fission products are given as a function of the following factors: concentration of the various ions in solution, valency states. A method of plutonium purification based on these results is presented. (author) [French] La trilaurylamine diluee par un solvant paraffinique (dodecane) a ete etudiee dans le cadre des recherches concernant la separation et la purification du plutonium. Une etude des caracteres physiques (solubilite des nitrates dans l'amine en fonction de la temperature) s'ajoute a celle de la tenue aux radiations de ce corps. Les caracteristiques d'extraction de solutions nitriques de plutonium, uranium, et certains produits de fission, sont donnes en fonction des facteurs suivants: concentration des differents ions en solution, etats de valence. On presente une methode de purification du plutonium basee sur ces resultats. (auteur)

  8. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen; Didas, Stephanie A.; Jones, Christopher W.

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams

  9. Early Post-Irradiation Changes in the Metabolism of Biogenic Amines; Les Changements Precoces du Metabolisme des Amines Biogenes apres Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Deanovic, Z [Institut Rudjer Boskovic, Zagreb, Yugoslavia (Croatia)

    1971-03-15

    There is accumulating evidence for the radiation-induced release of biogenic amines from their body stores. Having in mind the high patho-physiological activity of these ''local'' hormones and ''neuro-hormones'', it is reasonable to assume that they play an important role in the pathogenesis of the acute radiation syndrome. Under these pathological conditions the possible synergic and antagonistic effects of biogenic amines due to their complex interactions must be taken into consideration. The extent and dose-dependence of post-irradiation changes in the metabolism of histamine, serotonin, catecholamines and acetylcholine will be examined regarding particularly the search for biochemical indicators of radiation injury. The determination of bio-amines and their metabolites in urine seems to be a suitable method for following up those metabolic changes which could be of a biodosimetrical and/or prognostical value. Data published on this subject, obtained in experimental animals as well as in man, have been reviewed and the applicability of these tests is discussed. (author) [French] Des preuves se sont accumulees, qui demontrent que les amines biogenes sont liberees de leurs depots sous l'effet des rayonnements ionisants. Etant donne la grande activite pathophysiologique de ces hormones 'locales' et 'neurohormones', il est raisonnable de considerer que ces substances biogenes jouent un role important dans la pathogenese du syndrome aigu d'irradiation. Dans ces conditions pathologiques il faut tenir compte des effets synergiques et antagonistes des bio-amines, lies a des interactions compliquees. Les changements metaboliques en fonction de la dose recue font l'objet d'un examen qui englobe les alterations quantitatives de .'histamine, de la serotonine, des catecholamines et de l'acetylcholine et dont l'objectif est la recherche sur des indicateurs biochimiques de la lesion provoquee par l'irradiation. L'analyse des bio-amines et de leurs metabolites dans les urines

  10. Decomposition of some amines and amino acids in steam generator environments

    International Nuclear Information System (INIS)

    Jayaweera, P.; Hettiarachchi, S.; Millett, P.J.

    1994-01-01

    Hydrothermal decomposition rate constants and high temperature pH values of some selected high-molecular weight amines and amino acids were measured under simulated steam generator conditions. These amines and amino acids were evaluated as potential crevice buffering agents for steam generator applications in pressurized water reactors. The study showed that, although the high molecular weight amines undergo hydrothermal decomposition, they have a better buffer capacity than their low molecular weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the simulated crevice solution by as much as 2.84 to 4.24 units. However, volatility data for the amines and amino acids are needed before in-plant testing to ensure that amines can concentrate sufficiently in steam generator crevices to provide effective buffering

  11. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

  12. Evolution des acides aminés libres dans le moût de raisin sous l'action des levures de fleur

    Directory of Open Access Journals (Sweden)

    M.C. POLO

    1974-03-01

    La plus grande partie des travaux qui existent dans la bibliographie sur la teneur en acides aminés du raisin pendant l'évolution de la maturation ainsi que sur les teneurs des moûts et des vins de différents pays, ont été réalisés par chromatographie sur papier ou en utilisant des méthodes microbiologiques ou colorimétriques.

  13. Diazotisation of Weakly Basic Aromatic and Heterocyclic Amines in Strongly Acid Media

    Science.gov (United States)

    Godovikova, Tamara I.; Rakitin, Oleg A.; Khmel'nitskii, Lenor I.

    1983-05-01

    The review is devoted to the diazotisation of weakly basic aromatic amines. The methods of synthesis of diazonium salts based on these amines by non-traditional methods are examined. Data on the mechanism of the diazotisation reaction in strongly acid media are surveyed. Reactions of diazonium salts leading to the synthesis of new compounds are presented. The bibliography includes 75 references.

  14. Elaboration and characterisation of acids catalyst for the obtention of amines

    International Nuclear Information System (INIS)

    Khemaissia, S.; Zaoui, B.; Nibou, D.

    1997-04-01

    The nuclear energy has shown the interest of aminated substances as solvents for removal and purification. These extractants are generally used in uranium ores treatment processes and several technology fields, specially, in organic and pharmaceutical industries. The present work deals with elaboration and characterization of acidic solid catalyst used in aminated extractants obtaining

  15. Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA).

    Science.gov (United States)

    Chatterjee, Nachiketa; Goswami, Avijit

    2015-08-07

    A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.

  16. Composition of amino acids and bioactive amines in common wines of Brazil

    Directory of Open Access Journals (Sweden)

    Bruna Carla Agustini

    2014-10-01

    Full Text Available Since most consumed wines in Brazil are common wines and since their representativeness is not accounted for in scientific research, current study quantifies bioactive amines and their precursors in Brazilian sweet and dry common wines, correlates the formation of amines with physical and chemical parameters and clusters studied areas by their amine and amino acid contents. Forty-seven wine samples varying in type, color and origin were analyzed simultaneously for seventeen amino acids, ammonium ion and five bioactive amines by reversed-phase high performance liquid chromatography and ultraviolet detection after the derivation phase. Physical and chemical analyses comprised titratable acidity, pH, organic acids, sugar and alcohol contents. Sweet wines had lower concentrations of amino acids and bioactive amines. Dry white wines had higher amino acid contents when compared to those in dry red wines. Since multivariate data analysis confirmed similarities between the studied regions, their unity as potential viniculture area was reinforced. Amine levels in Brazilian common wines were reported for the first time and results reinforced the importance of bioactive amines quantification and the use of suitable vinification practices to reduce their formation.

  17. A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

    Science.gov (United States)

    Andrews, Keith G.; Faizova, Radmila; Denton, Ross M.

    2017-06-01

    Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through the introduction of fluorine is of paramount importance in medicinal chemistry. Current synthesis methods for the construction of fluorinated amines rely on air and moisture sensitive reagents that require special handling or harsh reductants that limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions of free amines exhibiting remarkable functional group tolerance. The reactions proceed in conventional glassware without rigorous exclusion of either moisture or oxygen, and use trifluoroacetic acid as a stable and inexpensive fluorine source. The new methods provide access to a wide range of medicinally relevant functionalized tertiary β-fluoroalkylamine cores, either through direct trifluoroethylation of secondary amines or via a three-component coupling of primary amines, aldehydes and trifluoroacetic acid. A reduction of in situ-generated silyl ester species is proposed to account for the reductive selectivity observed.

  18. Efficient acetylation of primary amines and amino acids in ...

    Indian Academy of Sciences (India)

    bDepartment of Clinical and Experimental Pharmacology, School of Tropical Medicine ... As a result ... methods of acetylation of amines are known using ace- ... vents we report here, environmentally benign, eco- ... It was filtered under suction,.

  19. Contribution to the study of the mechanism of extraction of uranyl chloride by long chain aliphatic amines; Contribution a l'etude du mecanisme d'extraction du chlorure d'uranyle par les amines aliphatiques a longues chaines

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, G R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    After having studied and developed the mechanisms which may 'a priori' explain the extraction process (co-ordination, ion association or intermediate mechanism), experience shows that ion association only should be taken into consideration. The structure of the organic complex of uranyl chloride has been defined on the basis of the study of the variation of the distribution coefficient of uranium between the two phases at the equilibrium as a function of successively the activity of Cl{sup -} ions in the aqueous phase, the concentration of amine salt in the organic phase and finally of the concentration of uranium in the aqueous phase. The plotting of the results in bi-logarithmic co-ordinates enables us to propose the following formula for the extracted compound: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. The calculation of the equilibrium constant of formation of the organic compound of uranyl chloride has been possible in the case of diluted solutions of uranium only. (author) [French] Apres avoir expose et developpe les mecanismes qui a priori pouvaient expliquer le processus d'extraction (coordination, association d'ions ou mecanisme intermediaire), le recours a l'experience a finalement permis de ne retenir que l'association d'ions. La structure du complexe organique de chlorure d'uranyle a ete definie a partir de l'etude de la variation du coefficient de partage de l'uranium entre les deux phases a l'equilibre en fonction successivement de l'activite des ions Cl{sup -} en phase aqueuse, de la concentration de sel d'amine en phase organique et enfin de la concentration d'uranium de la phase aqueuse. La representation bilogarithmique des resultats de ces essais a permis de proposer la formule suivante pour le compose extrait: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. Le calcul de la constante d'equilibre de formation du compose organique de chlorure d'uranyle a ete seulement possible pour les solutions diluees en uranium. (auteur)

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

    Science.gov (United States)

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

    2015-07-27

    A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Visible-Light-Promoted Metal-Free Aerobic Oxidation of Primary Amines to Acids and Lactones.

    Science.gov (United States)

    Cheng, Xiaokai; Yang, Bo; Hu, Xingen; Xu, Qing; Lu, Zhan

    2016-12-05

    A unique metal-free aerobic oxidation of primary amines via visible light photocatalytic double carbon-carbon bonds cleavage and multi carbon-hydrogen bonds oxidation was observed. Aerobic oxidation of primary amines could be controlled to afford acids by using dioxane with 18 W CFL, and lactones by using DMF with 8 W green LEDs, respectively. A plausible mechanism was proposed based on control experiments. This observation showed direct evidences for the fragmentation in the aerobic oxidation of aliphatic primary amines. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Effect of Amine Adlayer on Electrochemical Uric Acid Sensor Conducted on Electrochemically Reduced Graphene Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sumi; Kim, Kyuwon [Incheon National University, Incheon (Korea, Republic of)

    2016-03-15

    The electrochemical biosensing efficiency of uric acid (UA) detection on an electrochemically reduced graphene oxide (ERGO)-decorated electrode surface was studied by using various amine linkers used to immobilize ERGO. The amine linkers aminoethylphenyldiazonium , 2,2'-(ethylenedioxy)bis(ethylamine), 3-aminopro-pyltriethoxysilane, and polyethyleneimine were coated on indium-tin-oxide electrode surfaces through chemical or electrochemical deposition methods. ERGO-decorated surfaces were prepared by the electrochemical reduction of graphene oxide (GO), which was immobilized on the amine-coated electrode surfaces through the electrostatic interaction between GO and the ammonium ion of the linker on the surface. We monitored the sensing results of electrochemical UA detection with differential pulse voltammetry. The ERGO-modified surface presented electrocatalytic oxidation of UA and ascorbic acid. Among the different amines tested, 3-aminopropyltriethoxysilane provided the best biosensing performance in terms of sensitivity and reproducibility.

  3. Effect of Amine Adlayer on Electrochemical Uric Acid Sensor Conducted on Electrochemically Reduced Graphene Oxide

    International Nuclear Information System (INIS)

    Park, Sumi; Kim, Kyuwon

    2016-01-01

    The electrochemical biosensing efficiency of uric acid (UA) detection on an electrochemically reduced graphene oxide (ERGO)-decorated electrode surface was studied by using various amine linkers used to immobilize ERGO. The amine linkers aminoethylphenyldiazonium , 2,2'-(ethylenedioxy)bis(ethylamine), 3-aminopro-pyltriethoxysilane, and polyethyleneimine were coated on indium-tin-oxide electrode surfaces through chemical or electrochemical deposition methods. ERGO-decorated surfaces were prepared by the electrochemical reduction of graphene oxide (GO), which was immobilized on the amine-coated electrode surfaces through the electrostatic interaction between GO and the ammonium ion of the linker on the surface. We monitored the sensing results of electrochemical UA detection with differential pulse voltammetry. The ERGO-modified surface presented electrocatalytic oxidation of UA and ascorbic acid. Among the different amines tested, 3-aminopropyltriethoxysilane provided the best biosensing performance in terms of sensitivity and reproducibility.

  4. Brain uptake of pipecolic acid, amino acids, amines following intracarotid injection in the mouse

    International Nuclear Information System (INIS)

    Nishio, H.; Giacobini, E.

    1981-01-01

    The uptake of pipecolic acid by the mouse brain was compared to that of several amino acids and amines, following an injection of a double-labeled mixture into the carotid artery. In general, BUI (brain uptake index) values were lower in the mouse than those previously reported in the rat. The only exception was proline. Lysine, a precursor of pipecolic acid biosynthesis in brain, showed a higher BUI than pipecolic acid. The BUI of D,L-[3H]pipecolic acid was found to be 3.39 (at 0.114 mM). This was saturable between a concentration of 0.114 and 3.44 mM. Kinetic analysis suggests the presence of two kinds of transport systems. Substances structurally related to pipecolic acid, such as nipecotic acid, isonipecotic acid, L-proline, and piperidine show a significant inhibitory effect. Amont the amino acids tested, only GABA showed an inhibitory effect. Data are reported which, when considered with other findings present evidence that pipecolic acid is (1) synthesized both in vitro and in vivo in the mouse brain, (2) actively transported in vivo into the brain, and (3) taken up in vitro by synaptosomal preparations

  5. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Science.gov (United States)

    2010-07-01

    ... methods for protecting against such risk, into an MSDS as described in § 721.72(c) within 90 days from the..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... manner or method of manufacture, import, or processing associated with any use of this substance without...

  6. Efficient acetylation of primary amines and amino acids in ...

    Indian Academy of Sciences (India)

    This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the ...

  7. Acid-catalyzed reductive amination of aldoses with 8-aminopyrene-1,3,6-trisulfonate.

    Science.gov (United States)

    Evangelista, R A; Guttman, A; Chen, F T

    1996-02-01

    The reductive amination of monosaccharides with 8-aminopyrene-1,3,6-trisulfonate (APTS) in seven different organic acids including the commonly used acetic acid was investigated by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. The correlation between the yields of the saccharide-APTS adducts and pKa of the organic acid catalyst is consistent with general acid catalysis of the rate-determining step of the reductive amination reaction. Derivatization in the presence of organic acids of higher strength than acetic acid produced substantially higher yields of APTS-sugar adducts, an effect which is more pronounced for N-acetylamino sugars. Optimum yields were obtained using citric acid as a catalyst. Conversion of a few nanomoles of neutral saccharides to the APTS derivatives is achieved at 75 degrees C in less than 60 min.

  8. Reaction constants, in cyclohexane, of lauryl-amines with tetrabromo-phenolphthalein magenta E acid

    International Nuclear Information System (INIS)

    Perez, J.J.

    1966-11-01

    Trilauryl amine is an extracting agent used for plutonium purification. Its main degradation product is di-laurylamine. The titration of this impurity is carried out by spectro-colorimetry in cyclohexane using bromophtalein Magenta E as coloured acid indicator. The reported dissociation constants for alcoylammonium salts are too closed to lead to a discrimination between secondary and tertiary amines. The present spectrophotometric study shows that the ratios of various dissociation constants for bromophtalein Magenta E salts are notably different from those for salts of simple coloured acids like 2,4 dinitro phenol. The structural changes accompanying the colorations are discussed in order to explain this phenomenon. (author) [fr

  9. Density, viscosity, and N2O solubility of aqueous amino acid salt and amine amino acid salt solutions

    International Nuclear Information System (INIS)

    Aronu, Ugochukwu E.; Hartono, Ardi; Svendsen, Hallvard F.

    2012-01-01

    Highlights: ► Density of amino acid salt and amine amino acid salt. ► Viscosity of amino acid salt and amine amino acid salt. ► Henry’s law constant/N 2 O solubility of amino acid salt and amine amino acid salt. ► Schumpe model. Correlations for density, viscosity, and N 2 O solubility. - Abstract: Physicochemical properties of aqueous amino acid salt (AAS), potassium salt of sarcosine (KSAR) and aqueous amine amino acid salt (AAAS), 3-(methylamino)propylamine/sarcosine (SARMAPA) have been studied. Densities of KSAR were measured for sarcosine mole fraction 0.02 to 0.25 for temperature range 298.15 K to 353.15 K, the viscosities were measured for 0.02 to 0.10 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.10 mole fraction sarcosine solutions (298.15 K to 363.15 K). Densities of SARMAPA were measured for sarcosine mole fraction 0.02 to 0.23 for temperature range (298.15 K to 353.15 K), viscosities were measured for 0.02 to 0.16 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.16 mole fraction sarcosine solutions (298.15 K to 343.15 K). Experimental results were correlated well with empirical correlations and N 2 O solubility results for KSAR were predicted adequately by a Schumpe model. The solubilities of N 2 O in AAS and AAAS are significantly lower than values for amines. The solubilities vary as: amine > AAAS > AAS.

  10. Facile preparation of amine and amino acid adducts of [60]fullerene using chlorofullerene C60Cl6 as a precursor.

    Science.gov (United States)

    Kornev, Alexey B; Khakina, Ekaterina A; Troyanov, Sergey I; Kushch, Alla A; Peregudov, Alexander; Vasilchenko, Alexey; Deryabin, Dmitry G; Martynenko, Vyacheslav M; Troshin, Pavel A

    2012-06-04

    We report a general synthetic approach to the preparation of highly functionalized amine and amino acid derivatives of [60]fullerene starting from readily available chlorofullerene C(60)Cl(6). The synthesized water-soluble amino acid derivative of C(60) demonstrated pronounced antiviral activity, while the cationic amine-based compound showed strong antibacterial action in vitro.

  11. Amino Acids and Biogenic Amines Evolution during the Estufagem of Fortified Wines

    OpenAIRE

    Vanda Pereira; Ana C. Pereira; Juan P. Pérez Trujillo; Juan Cacho; José C. Marques

    2015-01-01

    The current study was focused on the impact of accelerated ageing (heating step) on the amino acid and biogenic amine profiles of fortified wines. In this sense, three Madeira wines from two commonly used grape varieties (one red and the other white) were analysed during the heating, at standard (45°C, 3 months) and overheating (70°C, 1 month) conditions, following a precolumn derivatization procedure using iodoacetic acid, o-phthaldialdehyde, and 2-mercaptoethanol, carried out in the injecti...

  12. Amino Acids and Biogenic Amines Evolution during the Estufagem of Fortified Wines

    Directory of Open Access Journals (Sweden)

    Vanda Pereira

    2015-01-01

    Full Text Available The current study was focused on the impact of accelerated ageing (heating step on the amino acid and biogenic amine profiles of fortified wines. In this sense, three Madeira wines from two commonly used grape varieties (one red and the other white were analysed during the heating, at standard (45°C, 3 months and overheating (70°C, 1 month conditions, following a precolumn derivatization procedure using iodoacetic acid, o-phthaldialdehyde, and 2-mercaptoethanol, carried out in the injection loop prior to RP-HPLC-FLD detection. Eighteen amino acids were identified, with arginine being the most abundant. An important decrease of the amino acid levels was detected during the standard heating (up to 30%, enhanced up to 61% by the temperature increase. Cysteine, histidine, and asparagine revealed the greatest decreases at 45°C. Conversely, some amino acids, such as asparagine, slightly increased. Four biogenic amines were identified but always in trace amounts. Finally, it was observed that the accelerated ageing did not favour the biogenic amine development. The results also indicate that the heating process promotes the amino acid transformation into new ageing products.

  13. Amine Chemistry at Aqueous Interfaces: The Study of Organic Amines in Neutralizing Acidic Gases at an Air/Water Surface Using Vibrational Sum Frequency Spectroscopy

    Science.gov (United States)

    McWilliams, L.; Wren, S. N.; Valley, N. A.; Richmond, G.

    2014-12-01

    Small organic bases have been measured in atmospheric samples, with their sources ranging from industrial processing to animal husbandry. These small organic amines are often highly soluble, being found in atmospheric condensed phases such as fogwater and rainwater. Additionally, they display acid-neutralization ability often greater than ammonia, yet little is known regarding their kinetic and thermodynamic properties. This presentation will describe the molecular level details of a model amine system at the vapor/liquid interface in the presence of acidic gas. We find that this amine system shows very unique properties in terms of its bonding, structure, and orientation at aqueous surfaces. The results of our studies using a combination of computation, vibrational sum frequency spectroscopy, and surface tension will report the properties inherent to these atmospherically relevant species at aqueous surfaces.

  14. Myeloperoxidase-catalyzed incorporation of amines into proteins: role of hypochlorous acid and dichloramines.

    Science.gov (United States)

    Thomas, E L; Jefferson, M M; Grisham, M B

    1982-11-23

    Myeloperoxidase-catalyzed oxidation of chloride (Cl-) to hypochlorous acid (HOCl) resulted in formation of mono- and dichloramine derivatives (RNHCl and RNCl2) of primary amines. The RNCl2 derivatives could undergo a reaction that resulted in incorporation of the R moiety into proteins. The probable mechanism was attack of RNCl2 or an intermediate formed in the decomposition of RNCl2 on histidine, tyrosine, and cystine residues and on lysine residues at high pH. Incorporation of radioactivity from labeled amines into stable, high molecular weight derivatives of proteins was measured by acid or acetone precipitation and by gel chromatography and electrophoresis. Whereas formation of RNCl2 was favored at low pH, the subsequent incorporation reaction was favored at high pH. Up to several hours were required for the maximum amount of incorporation, which was less than 10% of the label in RNCl2. For the amines tested, incorporation was in the order histamine greater than 1,2-diaminoethane greater than putrescine greater than taurine greater than lysine greater than glucosamine greater than leucine greater than methylamine. Initiation of the reaction required HOCl, and oxidized forms of bromide, iodide, or thiocyanate did not substitute. Inhibitors of incorporation fell into three classes. First, ammonia or amines competed with the labeled amine for reaction with HOCl, so that larger amounts of HOCl were required. Second, readily oxidized substances such as sulfhydryl or diketo compounds or thioethers (methionine) reduced RNCl2. Third, certain compounds competed with protein as the acceptor for the incorporation reaction. The amount required to block incorporation into protein depended on protein concentration. Among these inhibitors were imidazole compounds (histidine), phenols (tyrosine), and disulfides (glutathione disulfide, GSSG). Low yields of derivatives of histidine, tyrosine, and GSSG were detected by thin-layer chromatography. Acid-precipitable derivatives were

  15. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere.

    Science.gov (United States)

    Almeida, João; Schobesberger, Siegfried; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Worsnop, Douglas R; Vehkamäki, Hanna; Kirkby, Jasper

    2013-10-17

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid-amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid-dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.

  16. Postprandial Differences in the Amino Acid and Biogenic Amines Profiles of Impaired Fasting Glucose Individuals after Intake of Highland Barley

    Directory of Open Access Journals (Sweden)

    Liyan Liu

    2015-07-01

    Full Text Available The aim of this study was to measure the postprandial changes in amino acid and biogenic amine profiles in individuals with impaired fasting glucose (IFG and to investigate the changes of postprandial amino acid and biogenic amine profiles after a meal of highland barley (HB. Firstly, 50 IFG and 50 healthy individuals were recruited for the measurement of 2 h postprandial changes of amino acid and biogenic amine profiles after a glucose load. Secondly, IFG individuals received three different loads: Glucose (GL, white rice (WR and HB. Amino acid and biogenic amine profiles, glucose and insulin were assayed at time zero and 30, 60, 90 and 120 min after the test load. The results showed fasting and postprandial amino acid and biogenic amine profiles were different between the IFG group and the controls. The level of most amino acids and their metabolites decreased after an oral glucose tolerance test, while the postprandial level of γ-aminobutyric acid (GABA increased significantly in IFG individuals. After three different test loads, the area under the curve for glucose, insulin, lysine and GABA after a HB load decreased significantly compared to GL and WR loads. Furthermore, the postprandial changes in the level of GABA between time zero and 120 min during a HB load were associated positively with 2 h glucose and fasting insulin secretion in the IFG individuals. Thus, the HB load produced low postprandial glucose and insulin responses, which induced changes in amino acid and biogenic amine profiles and improved insulin sensitivity.

  17. Acid-base equilibria inside amine-functionalized mesoporous silica.

    Science.gov (United States)

    Yamaguchi, Akira; Namekawa, Manato; Kamijo, Toshio; Itoh, Tetsuji; Teramae, Norio

    2011-04-15

    Acid-base equilibria and effective proton concentration inside a silica mesopore modified with a trimethyl ammonium (TMAP) layer were studied by steady-state fluorescence experiments. The mesoporous silica with a dense TMAP layer (1.4 molecules/nm(2)) was prepared by a post grafting of N-trimethoxysilylpropyl-N,N,N-trimethylammonium at surfactant-templated mesoporous silica (diameter of silica framework =3.1 nm). The resulting TMAP-modified mesoporous silica strongly adsorbed of anionic fluorescence indicator dyes (8-hydroxypyrene-1,3,6-trisulfonate (pyranine), 8-aminopyrene-1,3,6-trisulfonate (APTS), 5,10,15,20-tetraphenyl-21H,23H-porphinetetrasulfonic acid disulfuric acid (TPPS), 2-naphthol-3,6-disulfonate (2NT)) and fluorescence excitation spectra of these dyes within TMAP-modified mesoporous silica were measured by varying the solution pH. The fluorescence experiments revealed that the acid-base equilibrium reactions of all pH indicator dyes within the TMAP-modified silica mesopore were quite different from those in bulk water. From the analysis of the acid-base equilibrium of pyranine, the following relationships between solution pH (pH(bulk)) and the effective proton concentration inside the pore (pH(pore)) were obtained: (1) shift of pH(pore) was 1.8 (ΔpH(pore)=1.8) for the pH(bulk) change from 2.1 to 9.1 (ΔpH(bulk)=7.0); (2) pH(pore) was not simply proportional to pH(bulk); (3) the inside of the TMAP-modified silica mesopore was suggested to be in a weak acidic or neutral condition when pH(bulk) was changed from 2.0 to 9.1. Since these relationships between pH(bulk) and pH(pore) could explain the acid-base equilibria of other pH indicator dyes (APTS, TPPS, 2NT), these relationships were inferred to describe the effective proton concentration inside the TMAP-modified silica mesopore. © 2011 American Chemical Society

  18. Extraction mechanism of Sc(III) from sulphuric acid solution by primary amine N1923

    International Nuclear Information System (INIS)

    Le Shaoming; Li Deqian; Ni Jiazan

    1987-01-01

    The extraction mechanism of Sc(III) from sulphuric acid solution by primary amine N 1923 (RNH 2 ) has been investigated by means of slope, isomolar continuous variation and saturation methods. The effect of temperature on the extraction of Sc(III) is observed. The extraction equilibrium constant and thermodynamic functions (ΔH, ΔS and ΔG) are obtained. The IR and NMR of extracted compound are measured

  19. Mechanism of the extraction of nitric acid and water by organic solutions of tertiary alkyl-amines; Mecanisme d'extraction de l'acide nitrique et de l'eau par les solutions organiques d'alcoylamines tertiaires

    Energy Technology Data Exchange (ETDEWEB)

    Gourisse, D

    1966-06-01

    The micellar aggregation of tri-alkyl-ammonium nitrates in low polarity organic solvents has been verified by viscosity, conductivity and sedimentation velocity measurements. The aggregation depends upon the polarity of solvent, the length of the alkyl radicals and the organic concentration of the various constituents (tri-alkyl-ammonium nitrate, tri-alkyl-amine, nitric acid, water). The amine salification law has been established and the excess nitric acid and water solubilities in the organic solutions have been measured. Nitric acid and water are slightly more soluble in micellar organic solutions than in molecular organic solutions. A description of excess nitric acid containing tri-alkyl-ammonium nitrate solutions is proposed. (author) [French] Mecanisme d'extraction de l'acide nitrique et de l'eau par les solutions organiques d'alcoylamines tertiaires. L'agregation micellaire des nitrates de trialcoylammonium dans les solvants peu polaires a ete verifiee par viscosimetrie, conductimetrie et ultracentrifugation des solutions organiques. L'agregation depend de la polarite du solvant, de la longueur des radicaux alcoyle, et des concentrations des differents constituants de la solution organique (nitrate de trialcoylammonium, alcoylamine tertiaire, acide nitrique, eau). La loi de salification de l'amine a ete determinee et les solubilites de l'acide nitrique en exces et de l'eau dans les solutions organiques ont ete mesurees. L'acide nitrique et l'eau sont legerement plus solubles dans les organiques micellaires que dans les solutions organiques moleculaires. Une description des solutions de nitrate de trialcoylammonium contenant de l'acide nitrique en exces est proposee. (auteur)

  20. Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere

    CERN Document Server

    Almeida, João; Kürten, Andreas; Ortega, Ismael K; Kupiainen-Määttä, Oona; Praplan, Arnaud P; Adamov, Alexey; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; David, André; Dommen, Josef; Donahue, Neil M; Downard, Andrew; Dunne, Eimear; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Guida, Roberto; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Henschel, Henning; Jokinen, Tuija; Junninen, Heikki; Kajos, Maija; Kangasluoma, Juha; Keskinen, Helmi; Kupc, Agnieszka; Kurtén, Theo; Kvashin, Alexander N; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Leppä, Johannes; Loukonen, Ville; Makhmutov, Vladimir; Mathot, Serge; McGrath, Matthew J; Nieminen, Tuomo; Olenius, Tinja; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Riipinen, Ilona; Rissanen, Matti; Rondo, Linda; Ruuskanen, Taina; Santos, Filipe D; Sarnela, Nina; Schallhart, Simon; Schnitzhofer, Ralf; Seinfeld, John H; Simon, Mario; Sipilä, Mikko; Stozhkov, Yuri; Stratmann, Frank; Tomé, Antonio; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Vaattovaara, Petri; Viisanen, Yrjo; Virtanen, Annele; Vrtala, Aron; Wagner, Paul E; Weingartner, Ernest; Wex, Heike; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Yli-Juuti, Taina; Carslaw, Kenneth S; Kulmala, Markku; Curtius, Joachim; Baltensperger, Urs; Vehkamaki, Hanna; Kirkby, Jasper

    2013-01-01

    Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei. Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes. Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases. However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere. It is thought that amines may enhance nucleation, but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates ...

  1. Ionic networks derived from the protonation of dendritic amines with carboxylic acid end‐functionalized PEGs

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Skov, Anne Ladegaard; Hvilsted, Søren

    2013-01-01

    The synthesis and characterization of novel ionic networks linked by the ammonium salts of poly(propylene imine) (PPI) dendrimers of the first (PPI G1) and second (PPI G2) generation and two short bis carboxymethyl ether terminated poly(ethylene glycol)s (DiCOOH‐PEG) with different molecular...... weights (Mn ∼ 250 and Mn ∼ 600) are reported. Likewise, an ionic network based on PPI G1 and a long αω‐dicarboxylic acid functionalized PEG (Mn ∼ 4800) were evaluated. Simpler ionic structures based on tris(2‐aminoethyl)amine or hexamethylene diamine and the short DiCOOH‐PEGs are also investigated....... The ionic structures formed were confirmed by differential scanning calorimetry, Fourier Transform Infrared spectroscopy in the attenuated‐total‐reflection mode, and 1H‐13C NMR spectroscopy. A comprehensive 1H NMR analysis revealed that only the primary amines of the PPI G1 dendrimer residing...

  2. Quality properties, fatty acids, and biogenic amines profile of fresh tilapia stored in ice.

    Science.gov (United States)

    Kulawik, Piotr; Özoğul, Fatih; Glew, Robert H

    2013-07-01

    This work determines quality properties and fatty acids content of Nile tilapia (Oreochromis niloticus) stored in ice for 21 d. The quality properties consist of thiobarbituic acid (TBA), total volatile basic nitrogen (TVB-N), trimethylamine (TMA), and microbiological analysis (total viable count (TVC), total coliform, Salmonella and Staphylococcus aureus) and determination of biogenic amines content (histamine, cadaverine, putrescine, spermine, spermidine, 2-phenylethylamine, agmatine, tyramine, and ammonia). Moreover, the fat, moisture, and ash composition as well as fatty acids profile have also been analyzed. The TBA, TVB-N, and biogenic amines analysis showed rather low levels of spoilage even after 21 d of storage. The microbiological analysis, however, showed that tilapia was unsuitable for consumption after just 10 d. The fat, ash, moisture, and fatty acids profile analysis showed that tilapia is not a good source of n-3 fatty acids. The research indicated that the microbiological analysis was the best method to establish spoilage of tilapia stored in ice, of all analytical methods performed in this study. © 2013 Institute of Food Technologists®

  3. Behavioral correlates of cerebrospinal fluid amino acid and biogenic amine neurotransmitter alterations in dementia.

    Science.gov (United States)

    Vermeiren, Yannick; Le Bastard, Nathalie; Van Hemelrijck, An; Drinkenburg, Wilhelmus H; Engelborghs, Sebastiaan; De Deyn, Peter P

    2013-09-01

    Behavioral and psychological signs and symptoms of dementia (BPSD) are a heterogeneous group of behavioral and psychiatric disturbances occurring in dementia patients of any etiology. Research suggests that altered activities of dopaminergic, serotonergic, (nor)adrenergic, as well as amino acid neurotransmitter systems play a role in the etiopathogenesis of BPSD. In this study we attempted to identify cerebrospinal fluid (CSF) neurochemical correlates of BPSD to provide further insight into its underlying neurochemical pathophysiological mechanisms. Patients with probable Alzheimer's disease (AD; n = 202), probable AD with cerebrovascular disease (n = 37), probable frontotemporal dementia (FTD; n = 32), and probable dementia with Lewy bodies (DLB; n = 26) underwent behavioral assessment and lumbar puncture. CSF levels of six amino acids and several biogenic amines and metabolites were analyzed using ultraperformance liquid chromatography with fluorescence detection and reversed-phase high-performance liquid chromatography with fluorescence detection. In the AD patients, CSF homovanillic acid/5-hydroxyindoleacetic acid (HVA/5HIAA) ratios correlated positively with anxieties/phobias, whereas CSF levels of taurine correlated negatively with depression and behavioral disturbances in general. In FTD patients, CSF levels of glutamate correlated negatively with verbally agitated behavior. In DLB patients, CSF levels of HVA correlated negatively with hallucinations. Several neurotransmitter systems can be linked to one specific behavioral syndrome depending on the dementia subtype. In addition to biogenic amines and metabolites, amino acids seem to play a major role in the neurochemical etiology of BPSD as well. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  4. The impacts of temperature, alcoholic degree and amino acids content on biogenic amines and their precursor amino acids content in red wine.

    Science.gov (United States)

    Lorenzo, C; Bordiga, M; Pérez-Álvarez, E P; Travaglia, F; Arlorio, M; Salinas, M R; Coïsson, J D; Garde-Cerdán, T

    2017-09-01

    The aim was to study how factors such as temperature, alcoholic degree, and amino acids supplementation are able to influence the content of tyramine, histamine, 2-phenylethylamine, tryptamine and their precursor amino acids in winemaking process. Biogenic amines and amino acids were quantified at the beginning, middle and end of alcoholic fermentation, and at the end of malolactic fermentation. In general, samples produced with amino acid supplementation did not show the highest concentrations of biogenic amines, except for histamine, which content increased with the addition of the four amino acids. The synthesis of tyramine was mainly affected by the temperature and alcoholic degree, the formation of phenylethylamine was largely influenced by alcoholic degree, and tryptamine synthesis principally depended on temperature. Interestingly, there was interaction between these three factors for the biogenic amines studied. In conclusion, winemaking conditions should be established depending on the biogenic amine which synthesis is required to be controlled. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Correlations between the 1H NMR chemical shieldings and the pKa values of organic acids and amines.

    Science.gov (United States)

    Lu, Juanfeng; Lu, Tingting; Zhao, Xinyun; Chen, Xi; Zhan, Chang-Guo

    2018-06-01

    The acid dissociation constants and 1 H NMR chemical shieldings of organic compounds are important properties that have attracted much research interest. However, few studies have explored the relationship between these two properties. In this work, we theoretically studied the NMR chemical shifts of a series of carboxylic acids and amines in the gas phase and in aqueous solution. It was found that the negative logarithms of the experimental acid dissociation constants (i.e., the pK a values) of the organic acids and amines in aqueous solution correlate almost linearly with the corresponding calculated NMR chemical shieldings. Key factors that affect the theoretically predicted pK a values are discussed in this paper. The present work provides a new way to predict the pK a values of organic/biochemical compounds. Graphical abstract The chemical shielding values of organic acids and amines correlate near linearly with their corresponding pK a values.

  6. Capillary Electrophoresis Analysis of Organic Amines and Amino Acids in Saline and Acidic Samples Using the Mars Organic Analyzer

    Science.gov (United States)

    Stockton, Amanda M.; Chiesl, Thomas N.; Lowenstein, Tim K.; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A.

    2009-11-01

    The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pKa values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75 mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50 mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions.

  7. An evaluation of the physiological activity of 9-amine-9-fluorenephosphonic acid derivatives

    Directory of Open Access Journals (Sweden)

    Henryk Skrabka

    2013-12-01

    Full Text Available The physiological activity of eleven 9-amine-9-fluorenephosphonic acid derivatives, synthesized at the Wrocław Polytechnic, was examined. The test plant was Spirodela oligorrhiza. The effect of these compounds on the increase of the dry matter of this plant was tested in eight-day experiments. The activity of the compounds was varied. The most toxic were nos. 2, 4, 9, 8, 5 and 6 which were lethal in low concentrations. Somewhat less toxic were nos. 7, 10 and 11; nos. 1 and 3 were the least toxic.

  8. Decomposition of formic acid over silica encapsulated and amine functionalised gold nanoparticles

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Kunov-Kruse, Andreas Jonas; Kegnæs, Søren

    2017-01-01

    Formic acid has recently attracted considerable attention as a safe and convenient source of hydrogen for sustainable chemical synthesis and renewable energy storage. Here, we show that silica encapsulated and amine functionalised gold nanoparticles are highly active catalysts for the production...... of hydrogen by vapour phase decomposition of formic acid. The core-shell catalysts are prepared in a reverse micelle system that makes it possible to control the size of the Au nanoparticles and the thickness of the SiO2 shells, which has a large impact on the catalytic activity. The smallest gold...... nanoparticles are 2.2 ± 0.3 nm in diameter and have a turnover frequency (TOF) of up to 958 h−1 at a temperature of 130 °C. Based on detailed in situ ATR-FTIR studies and results from kinetic isotope labelling experiments we propose that the active site is a low-coordinated and amine functionalised Au atom...

  9. Biogenic amines, amino acids and regional blood flow in rat brain after prenatal irradiation

    International Nuclear Information System (INIS)

    Deroo, J.; Gerber, G.B.; Maes, J.

    1986-01-01

    Damage to nerve cells after prenatal irradiation could affect their later ability to function normally. The concentration of several biogenic amines and amino acids was therefore determined at different times after prenatal irradiation with 0.95 Gy on day 10, 12 or 15 of pregnancy. The offspring was sacrified 0.5, 1, 3 and 6 months after birth and the following structures were dissected: Cortex, hippocampus, striatum, thalamus, hypothalamus, cerebellum and medulla. Biogenic amines isolated by HPLC and detected electrochemically were: Dopamine, DOPA, DOPAC, epinephrine, norepinephrine, serotonin and hydroxyindolacetate. Amino acids converted to their dansyl derivatives and separated by HPLC were: Aspartate, glutamate, glutamine, gamma aminobutyrate and taurine. Many neurotransmitters were found increased in brain after prenatal irradiation, particularly on day 12 and 15 p.c. Marked changes were found for serotonin in several brain structures and for dopamin in striatum. An increase was also found in glutamate, glutamine and GABA. Studies on regional blood flow using injection of labelled 15 μ microspheres did not reveal significant alterations after prenatal irradiation. (orig.)

  10. Tuning the acid/base properties of nanocarbons by functionalization via amination.

    Science.gov (United States)

    Arrigo, Rosa; Hävecker, Michael; Wrabetz, Sabine; Blume, Raoul; Lerch, Martin; McGregor, James; Parrott, Edward P J; Zeitler, J Axel; Gladden, Lynn F; Knop-Gericke, Axel; Schlögl, Robert; Su, Dang Sheng

    2010-07-21

    The surface chemical properties and the electronic properties of vapor grown carbon nanofibers (VGCNFs) have been modified by treatment of the oxidized CNFs with NH(3). The effect of treatment temperature on the types of nitrogen functionalities introduced was evaluated by synchrotron based X-ray photoelectron spectroscopy (XPS), while the impact of the preparation methods on the surface acid-base properties was investigated by potentiometric titration, microcalorimetry, and zeta potential measurements. The impact of the N-functionalization on the electronic properties was measured by THz-Time Domain spectroscopy. The samples functionalized via amination are characterized by the coexistence of acidic and basic O and N sites. The population of O and N species is temperature dependent. In particular, at 873 K nitrogen is stabilized in substitutional positions within the graphitic structure, as heterocyclic-like moieties. The surface presents heterogeneously distributed and energetically different basic sites. A small amount of strong basic sites gives rise to a differential heat of CO(2) adsorption of 150 kJ mol(-1). However, when functionalization is carried out at 473 K, nitrogen moieties with basic character are introduced and the maximum heat of adsorption is significantly lower, at approximately 90 kJ mol(-1). In the latter sample, energetically different basic sites coexist with acidic oxygen groups introduced during the oxidative step. Under these conditions, a bifunctional acidic and basic surface is obtained with high hydrophilic character. N-functionalization carried out at higher temperature changes the electronic properties of the CNFs as evaluated by THz-TDS. The functionalization procedure presented in this work allows high versatility and flexibility in tailoring the surface chemistry of nanocarbon material to specific needs. This work shows the potential of the N-containing nanocarbon materials obtained via amination in catalysis as well as electronic

  11. Extraction of {sup 95}(Zr, Nb) from oxalic acid solutions by means of tri-iso-octyl amine, Annex 8

    Energy Technology Data Exchange (ETDEWEB)

    Susic, M V; Maksimovic, Z B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za visoku aktivnost, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    The extractability of {sup 95}(Zr, Nb) with tri-iso-octyl amine in xylene from an oxalic acid solution has been investigated. The behaviour of uranium and other fission products has also been observed. The extraction of {sup 95}(Zr, Nb) has been studied as u function of oxalic acid and amine concentrations. Effects of the aqueous phase pH, uranium and the presence of other electrolytes have also been observed and the possibility of separating {sup 95}(Zr, Nb) from uranium and from other fission products considered (author)

  12. The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Esmeray Küley

    2013-01-01

    Full Text Available The influences of fish infusion decarboxylase broth (IDB on biogenic amines (BA formation by lactic acid bacteria (LAB were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream IDB. The result of the study showed that significant differences in ammonia (AMN and BA production were observed among the LAB strains in fish IDB (p < 0.05. The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM, dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L and mackerel (100.84 mg/L IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L in sardine IDB.

  13. 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.

  14. Amination of oxy acids in aqueous solution by gamma-irradiation

    International Nuclear Information System (INIS)

    Ema, Kimiko; Kato, Taizo; Shinagawa, Mutsuaki

    1978-01-01

    Alanin, β-alanine, glicine, and aspartic, α-amino-n-butyric, and γ-amino-n-butyric acids were obtained by γ-irradiation of aqueous ammonia solutions of lactic, β-oxypropionic, glycolic, malic, α-oxybutyric, and γ-oxybutyric acids, respectively. The yields of amino acids were examined for functions of radiation dose (0.75 - 3.55Mrad), concentrations of oxy acid (0.01 - 0.1M) and ammonia (0.1 - 15M), and substances added as radical (potassium iodide), and hydrated electron (nitrous oxide) scavengers. The maximum G-values were 0.6 for alanine in a solution of 0.1M lactic acid-4M ammonia and some nitrous oxide and 1.14 for β-alanine in a solution of 0.1M β-oxypropionic acid and 0.7M ammonia. The yield of alanine increased with increased concentrations of lactic acid and ammonia due to saturation of nitrous oxide but decreased when potassium iodide (0.03M) was added. The yield of β-alanine showed a maximum increase at ca. 0.7M ammonia and decreased when potassium iodide and nitrous oxide were added. Serine was obtained from G = 0.002 in a solution of β-oxypropionic acid and increased to G = 0.058 due to saturation of nitrous oxide. The manner of chemical amination due to radiation was studied from the above results. In general, oxy acids from which hydrogen has been abstracted by an H or OH radical react with ammonia to form amino acids. The effect of ammonia concentration on the yield of amino acids demonstrates that the NH 2 radical abstracts the α-hydrogen of lactic acid but does not react with the β-hydrogen of β-oxypropionic acid. The effect of nitrous oxide indicates that hydrated electrons interfere with alanine formation, contribute to β-alanine formation, react with the carboxyl group of lactic acids to form lactamide, and abstract the β-hydroxyl group of β-oxypropionic acids to form β-alanine. (Bell, E.)

  15. 3,3'-Diaryl-BINOL phosphoric acids as enantioselective extractants of benzylic primary amines.

    Science.gov (United States)

    Verkuijl, Bastiaan J V; de Vries, Johannes G; Feringa, Ben L

    2011-01-01

    We report that 3,3'-diaryl-BINOL phosphoric acids are effective enantioselective extractants in chiral separation methods based on reactive liquid-liquid extraction. These new extractants are capable of separating racemic benzylic primary amine substrates. The effect of the nature of the substituents at the 3,3'-positions of the host were examined as well as the structure of the substrate, together with important parameters such as the organic solvent, the pH of the aqueous phase, and the host stoichiometry. Titration of the substrate with the host was monitored by FTIR, NMR, UV-Vis, and CD spectroscopy, which provided insight into the structure of the host-guest complex involved in extraction. Copyright © 2010 Wiley-Liss, Inc.

  16. Dielectric properties of supramolecular ionic structures obtained from multifunctional carboxylic acids and amines

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Yu, Liyun; Hvilsted, Søren

    2014-01-01

    The dielectric properties of several supramolecular ionic polymers and networks, linked by the ammonium salts of hexamethylene diamine (HMDA), tris(2-aminoethyl)amine (TAEA), poly(propylene imine) (PPI) dendrimers and two short bis carboxymethyl ether-terminated poly(ethylene glycol)s (Di......COOH-PEG), are reported in this paper. All supramolecular ionic polymers and networks exhibit very high relative dielectric permittivities ( 3 0 )( 10 2 – 10 6 ) at low frequencies, and signi fi cantly lower values (from 1 up to 26) at high frequencies. Additionally, the dielectric properties of supramolecular ionic......), are investigated. Here the relative dielectric permittivities of the supramolecular ionic structures formed with the multifunctional carboxylic acids were lower than those from the supramolecular ionic structures formed with the two carboxymethyl ether-terminated poly(ethylene glycol)s....

  17. Nuclear magnetic resonance titration studies of simple host-guest amine-carboxylic acid systems

    International Nuclear Information System (INIS)

    Mahinay, Myrna S.; Lindoy, Leonard F.

    1999-01-01

    Adduct formation for the open-chain 1,2-diaminoethane and its N-methyl derivatives [N,N-dimethyl-ethylenediamine (N,N-DMEN),N,N'-dimethylethylenediamine (N,N'-DMEN);N,N,N',N'-tetramethyl-ethylenediamine (N,N,N',N'-TMEN)]; 1,4-diaminobutane; diethylenetriamine (DIEN); triethylenetramine (TRIEN); and the carboxylic acid systems in polar CD 3 OH and nonpolar CDCl 3 solvents were elucidated by nmr titration. The stoichiometries of the adducts were found to correspond to the number of nitrogen present in the amine species with the exception of ligand incorporating N-donors of low basicity; that is, whose log K values for the protonated species in water were less than approximately 6 to 7.(Author)

  18. Antiglycation, radical scavenging, and semicarbazide-sensitive amine oxidase inhibitory activities of acetohydroxamic acid in vitro

    Directory of Open Access Journals (Sweden)

    Liu YH

    2017-07-01

    Full Text Available Yuh-Hwa Liu,1,2,* Yeh-Lin Lu,3,* Der-Zen Liu,4 Wen-Chi Hou5 1Division of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 2Department of General Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3Department of Pharmacy, Taipei Medical University, Taipei, Taiwan; 4Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei, Taiwan; 5Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan *These authors contributed equally to this work Abstract: Advanced glycation endproducts (AGEs can promote intracellular reactive oxygen species production, and the levels of AGEs are highly correlated with cardiovascular disease and diabetes complications. Acetohydroxamic acid (acetH is a bacterial urease inhibitor drug used to treat kidney stones and infections in the urinary tract, and hydroxyurea (HU is a drug used for antineoplasm and sickle cell diseases. Both acetH and HU are hydroxamic acid derivatives. It was found that acetH and HU at 2.5 or 5 mM showed anti-AGE formation by lowering the AGEs’ fluorescent intensities and Nε-(carboxymethyllysine formation in bovine serum albumin/galactose models, and both showed better and significant differences (P<0.05 compared to the positive control of aminoguanidine. Regarding radical scavenging activities, the half-inhibition concentrations (IC50 of acetH against α,α-diphenyl-β-picrylhydrazyl radical and hydroxyl radical were 34.86 and 104.42 µM, respectively. The IC50 of acetH against semicarbazide-sensitive amine oxidase was 10.56 µM, and acetH showed noncompetitive inhibition respective to the substrates (benzylamine. The antiglycation, antioxidant, and semicarbazide-sensitive amine oxidase inhibitory activities of acetH prove that it has the potential for treating cardiovascular disease and diabetes complications and it needs further investigation in animal models. Keywords: acetH, AGEs, Nε

  19. 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…

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

    Science.gov (United States)

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

  1. Amine-Functionalized Amino Acid-based Ionic Liquids as Efficient and High-Capacity Absorbents for CO2

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Kunov-Kruse, Andreas Jonas; Fehrmann, Rasmus

    2014-01-01

    Ionic liquids (ILs) comprised of ammonium cations and anions of naturally occurring amino acids containing an additional amine group (e.g., lysine, histidine, asparagine, and glutamine) were examined as high-capacity absorbents for CO2. An absorption capacity of 2.1 mol CO2 per mol of IL (3.5 mol...

  2. Aldehyde Selective Wacker Oxidations of Phthalimide Protected Allylic Amines : A New Catalytic Route to beta(3)-Amino Acids

    NARCIS (Netherlands)

    Weiner, Barbara; Baeza Garcia, Alejandro; Jerphagnon, Thomas; Feringa, Ben L.

    2009-01-01

    A new method for the synthesis of B-3-amino acids is presented. Phthalimide protected allylic amines are oxidized under Wacker conditions selectively to aldehydes using PdCl2 and CuCl or Pd(MeCN)(2)Cl(NO2) and CuCl2 as complementary catalyst systems. The aldehydes are produced in excellent yields

  3. Mechanism of the extraction of nitric acid and water by organic solutions of tertiary alkyl-amines

    International Nuclear Information System (INIS)

    Gourisse, D.

    1966-06-01

    The micellar aggregation of tri-alkyl-ammonium nitrates in low polarity organic solvents has been verified by viscosity, conductivity and sedimentation velocity measurements. The aggregation depends upon the polarity of solvent, the length of the alkyl radicals and the organic concentration of the various constituents (tri-alkyl-ammonium nitrate, tri-alkyl-amine, nitric acid, water). The amine salification law has been established and the excess nitric acid and water solubilities in the organic solutions have been measured. Nitric acid and water are slightly more soluble in micellar organic solutions than in molecular organic solutions. A description of excess nitric acid containing tri-alkyl-ammonium nitrate solutions is proposed. (author) [fr

  4. Extraction of sulphates by long chain amines; Extraction des sulfates par les amines a longues chaines

    Energy Technology Data Exchange (ETDEWEB)

    Boirie, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-05-15

    The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [French] L'extraction de l'acide sulfurique par des amines a longues chaines en solution organique a ete etudiee en vue de la determination de la valeur des constantes de stabilite des sulfates et bisulfates d'amines formes. Parmi les sulfates, nous nous sommes particulierement interesses au sulfate d'uranium et au sulfate de thorium. Nous avons determine les formules des complexes extractibles avec les amines, ainsi que les constantes de dissociation correspondantes. Nous avons remarque que pour le sulfate d'uranium, la formule du complexe ne depend que de la nature de l'amine, alors que pour le thorium cette formule varie avec la structure de l'amine. Les formules determinees et la valeur des constantes calculees, nous ont permis de decrire les meilleures conditions d'extraction de l'uranium et du thorium ainsi que celles d'une separation de ces deux elements. Nous proposons enfin une application de cette etude au dosage de l'uranium dans les minerais, ou la separation de l'uranium par cette methode est

  5. Contribution of the microbial and meat endogenous enzymes to the free amino acid and amine contents of dry fermented sausages.

    Science.gov (United States)

    Hierro, E; de La Hoz, L; Ordóñez, J A

    1999-03-01

    The role of the starter culture and meat endogenous enzymes on the free amino acid and amine contents of dry fermented sausages was studied. Five batches of sausages were prepared. The control batch was manufactured with aseptic ingredients without microbial inoculation. The other four experimental batches were manufactured with aseptic ingredients inoculated with Lactobacillus plantarum 4045 or Micrococcus-12 or L. plantarum 4045 and Micrococcus-12 or L. plantarum 4045 and Staphylococcus sp. Their effects on pH, a(w), myofibrillar proteins, and free amino acid and amine contents were studied. Sausages inoculated only with L. plantarum 4045 or with this starter combined with a Micrococcaceae had the lowest pH as a result of carbohydrate fermentation. In all batches similar patterns were observed for myofibrillar proteins and free amino acids which could indicate that meat endogenous proteases play an important role in proteolytic phenomena. No changes were observed in the amine fraction, indicating that the strains used as starter cultures did not show amino acid decarboxylase activity.

  6. Regulation of adipose branched-chain amin acid catabolism enzyme expression and cross-adipose amino acid flux in human obesity

    Science.gov (United States)

    Elevated blood branched-chain amin acids (BCAA)are often assoicated with insulin resistance and type2 diabetes, which might result from a reduced cellular utilization and/or incomplete BCAA oxidation. White adipose tissue (WAT) has become appreciated as a potential player in whole body BCAA metaboli...

  7. Contribution to the study of the mechanism of extraction of uranyl chloride by long chain aliphatic amines; Contribution a l'etude du mecanisme d'extraction du chlorure d'uranyle par les amines aliphatiques a longues chaines

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, G.R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    After having studied and developed the mechanisms which may 'a priori' explain the extraction process (co-ordination, ion association or intermediate mechanism), experience shows that ion association only should be taken into consideration. The structure of the organic complex of uranyl chloride has been defined on the basis of the study of the variation of the distribution coefficient of uranium between the two phases at the equilibrium as a function of successively the activity of Cl{sup -} ions in the aqueous phase, the concentration of amine salt in the organic phase and finally of the concentration of uranium in the aqueous phase. The plotting of the results in bi-logarithmic co-ordinates enables us to propose the following formula for the extracted compound: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. The calculation of the equilibrium constant of formation of the organic compound of uranyl chloride has been possible in the case of diluted solutions of uranium only. (author) [French] Apres avoir expose et developpe les mecanismes qui a priori pouvaient expliquer le processus d'extraction (coordination, association d'ions ou mecanisme intermediaire), le recours a l'experience a finalement permis de ne retenir que l'association d'ions. La structure du complexe organique de chlorure d'uranyle a ete definie a partir de l'etude de la variation du coefficient de partage de l'uranium entre les deux phases a l'equilibre en fonction successivement de l'activite des ions Cl{sup -} en phase aqueuse, de la concentration de sel d'amine en phase organique et enfin de la concentration d'uranium de la phase aqueuse. La representation bilogarithmique des resultats de ces essais a permis de proposer la formule suivante pour le compose extrait: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. Le calcul de la constante d'equilibre de formation du compose organique de chlorure d

  8. Metabolic Signature of Remote Ischemic Preconditioning Involving a Cocktail of Amino Acids and Biogenic Amines.

    Science.gov (United States)

    Chao de la Barca, Juan Manuel; Bakhta, Oussama; Kalakech, Hussein; Simard, Gilles; Tamareille, Sophie; Catros, Véronique; Callebert, Jacques; Gadras, Cédric; Tessier, Lydie; Reynier, Pascal; Prunier, Fabrice; Mirebeau-Prunier, Delphine

    2016-09-24

    Remote ischemic preconditioning (RIPC) is an attractive therapeutic procedure for protecting the heart against ischemia/reperfusion injury. Despite evidence of humoral mediators transported through the circulation playing a critical role, their actual identities so far remain unknown. We sought to identify plasmatic RIPC-induced metabolites that may play a role. Rat plasma samples from RIPC and control groups were analyzed using a targeted metabolomic approach aimed at measuring 188 metabolites. Principal component analysis and orthogonal partial least-squares discriminant analysis were used to identify the metabolites that discriminated between groups. Plasma samples from 50 patients subjected to RIPC were secondarily explored to confirm the results obtained in rats. Finally, a combination of the metabolites that were significantly increased in both rat and human plasma was injected prior to myocardial ischemia/reperfusion in rats. In the rat samples, 124 molecules were accurately quantified. Six metabolites (ornithine, glycine, kynurenine, spermine, carnosine, and serotonin) were the most significant variables for marked differentiation between the RIPC and control groups. In human plasma, analysis confirmed ornithine decrease and kynurenine and glycine increase following RIPC. Injection of the glycine and kynurenine alone or in combination replicated the protective effects of RIPC seen in rats. We have hereby reported significant variations in a cocktail of amino acids and biogenic amines after remote ischemic preconditioning in both rat and human plasma. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01390129. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  9. Primordial Synthesis of Amines and Amino Acids in a 1958 Miller H2S-Rich Spark Discharge Experiment

    Science.gov (United States)

    Parker, Eric T.; Cleaves, Henderson J.; Dworkin, Jason P.; Glavin, Daniel P.; Callahan, Michael; Aubrey, Andrew; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Archived samples from a previously unreported 1958 Stanley Miller electric discharge experiment containing hydrogen sulfide (H2S) were recently discovered and analyzed using high-performance liquid chromatography and time-of-flight mass spectrometry. We report here the detection and quantification of primary amine-containing compounds in the original sample residues, which were produced via spark discharge using a gaseous mixture of H2S, CH4, NH3, and CO2. A total of 23 amino acids and 4 amines, including 7 organosulfur compounds, were detected in these samples. The major amino acids with chiral centers are racemic within the accuracy of the measurements, indicating that they are not contaminants introduced during sample storage. This experiment marks the first synthesis of sulfur amino acids from spark discharge experiments designed to imitate primordia! environments. The relative yield of some amino acids, in particular the isomers of aminobutyric acid, are the highest ever found in a spark discharge experiment. The simulated primordial conditions used by Miller may serve as a model for early volcanic plume chemistry and provide insight to the possible roles such plumes may have played in abiotic organic synthesis. Additionally, the overall abundances of the synthesized amino acids in the presence of H2S are very similar to the abundances found in some carbonaceous meteorites, suggesting that H2S may have played an important role in prebiotic reactions in early solar system environments.

  10. Saponification of esters of chiral alpha-amino acids anchored through their amine function on solid support.

    Science.gov (United States)

    Cantel, Sonia; Desgranges, Stéphane; Martinez, Jean; Fehrentz, Jean-Alain

    2004-06-01

    Anchoring an alpha-amino acid residue by its amine function onto a solid support is an alternative to develop chemistry on its carboxylic function. This strategy can involve the use of amino-acid esters as precursors of the carboxylic function. A complete study on the Wang-resin was performed to determine the non racemizing saponification conditions of anchored alpha-amino esters. The use of LiOH, NaOH, NaOSi(Me)3, various solvents and temperatures were tested for this reaction. After saponification and cleavage from the support, samples were examined through their Marfey's derivatives by reversed phase HPLC to evaluate the percentage of racemization.

  11. Study of the effect of vintage, maturity degree, and irrigation on the amino acid and biogenic amine content of a white wine from the Verdejo variety.

    Science.gov (United States)

    Ortega-Heras, Miriam; Pérez-Magariño, Silvia; Del-Villar-Garrachón, Vanesa; González-Huerta, Carlos; Moro Gonzalez, Luis Carlos; Guadarrama Rodríguez, Alberto; Villanueva Sanchez, Sonia; Gallo González, Rubén; Martín de la Helguera, Sara

    2014-08-01

    The aim of this study was to determine the effect of three factors directly related to the amino acid content of grapes and their interaction. These three factors were vintage, maturity degree and irrigation. The evolution of amino acid was also assessed during the winemaking along with the effect of maturity and irrigation on the biogenic amine formation. The grapes used for this study were of the Verdejo variety. The results indicated that there was a strong vintage effect on amino acid content in grapes, which seemed to be clearly related to climatic conditions. The effect of maturity on amino acid content depended on vintage, irrigation and the amino acid itself although it was observed that irrigation caused the increase of most amino acids present in the berry. Irrigation did not affect the evolution of nitrogen compounds during the alcoholic fermentation process but the maturity degree in some of the amino acids tested did so. No direct relationship could be established between irrigation or maturity degree and biogenic amines. However, it should be noted that the biogenic amine content was very low. Vintage has a strong effect on the amino acid content in grapes which appears to be related to weather conditions. No direct relationship has been found between irrigation or maturity degree and biogenic amines content. Furthermore, it is noted that biogenic amine content found in final wines was very low. © 2013 Society of Chemical Industry.

  12. Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation.

    Science.gov (United States)

    Mirza-Aghayan, Maryam; Tavana, Mahdieh Molaee; Boukherroub, Rabah

    2016-03-01

    Sulfonated reduced graphene oxide nanosheets (rGO-SO3H) were prepared by grafting sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide (rGO) under sonochemical conditions. rGO-SO3H catalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). rGO-SO3H catalyst was successfully applied as a reusable solid acid catalyst for the direct amidation of carboxylic acids with amines into the corresponding amides under ultrasonic irradiation. The direct sonochemical amidation of carboxylic acid takes place under mild conditions affording in good to high yields (56-95%) the corresponding amides in short reaction times. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Poole, Loree Joanne [Univ. of California, Berkeley, CA (United States); King, C. Judson [Univ. of California, Berkeley, CA (United States)

    1990-03-01

    Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO2 and H2S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The

  14. On the formation of sulphuric acidamine clusters in varying atmospheric conditions and its influence on atmospheric new particle formation

    Directory of Open Access Journals (Sweden)

    I. K. Ortega

    2012-10-01

    Full Text Available Sulphuric acid is a key component in atmospheric new particle formation. However, sulphuric acid alone does not form stable enough clusters to initiate particle formation in atmospheric conditions. Strong bases, such as amines, have been suggested to stabilize sulphuric acid clusters and thus participate in particle formation. We modelled the formation rate of clusters with two sulphuric acid and two amine molecules (JA2B2 at varying atmospherically relevant conditions with respect to concentrations of sulphuric acid ([H2SO4], dimethylamine ([DMA] and trimethylamine ([TMA], temperature and relative humidity (RH. We also tested how the model results change if we assume that the clusters with two sulphuric acid and two amine molecules would act as seeds for heterogeneous nucleation of organic vapours (other than amines with higher atmospheric concentrations than sulphuric acid. The modelled formation rates JA2B2 were functions of sulphuric acid concentration with close to quadratic dependence, which is in good agreement with atmospheric observations of the connection between the particle formation rate and sulphuric acid concentration. The coefficients KA2B2 connecting the cluster formation rate and sulphuric acid concentrations as JA2B2=KA2B2[H2SO4]2 turned out to depend also on amine concentrations, temperature and relative humidity. We compared the modelled coefficients KA2B2 with the corresponding coefficients calculated from the atmospheric observations (Kobs from environments with varying temperatures and levels of anthropogenic influence. By taking into account the modelled behaviour of JA2B2 as a function of [H2SO4], temperature and RH, the atmospheric particle formation rate was reproduced more closely than with the traditional semi-empirical formulae based on sulphuric acid concentration only. The formation rates of clusters with two sulphuric acid and two amine molecules with different amine compositions (DMA or TMA or one of both had

  15. Phosphotungstic acid encapsulated in the mesocages of amine-functionalized metal-organic frameworks for catalytic oxidative desulfurization.

    Science.gov (United States)

    Wang, Xu-Sheng; Huang, Yuan-Biao; Lin, Zu-Jin; Cao, Rong

    2014-08-21

    Highly dispersed Keggin-type phosphotungstic acid (H3PW12O40, PTA) encapsulated in the mesocages of amine-functionalized metal-organic frameworks MIL-101(Cr)-NH2 has been prepared by an anion-exchange method. PTA anions (PW12O40(3-)) are stabilized in the mesocages via the electrostatic interaction with amino groups of the MIL-101(Cr)-NH2. The obtained catalyst (denoted PTA@MIL-101(Cr)-NH2) exhibits high catalytic activity in the extractive and catalytic oxidative desulfurization (ECODS) system under mild conditions. Moreover, it can be easily recovered and recycled several times without leaching and loss of activity.

  16. Systematic evaluation and optimization of modification reactions of oligonucleotides with amines and carboxylic acids for the synthesis of DNA-encoded chemical libraries.

    Science.gov (United States)

    Franzini, Raphael M; Samain, Florent; Abd Elrahman, Maaly; Mikutis, Gediminas; Nauer, Angela; Zimmermann, Mauro; Scheuermann, Jörg; Hall, Jonathan; Neri, Dario

    2014-08-20

    DNA-encoded chemical libraries are collections of small molecules, attached to DNA fragments serving as identification barcodes, which can be screened against multiple protein targets, thus facilitating the drug discovery process. The preparation of large DNA-encoded chemical libraries crucially depends on the availability of robust synthetic methods, which enable the efficient conjugation to oligonucleotides of structurally diverse building blocks, sharing a common reactive group. Reactions of DNA derivatives with amines and/or carboxylic acids are particularly attractive for the synthesis of encoded libraries, in view of the very large number of building blocks that are commercially available. However, systematic studies on these reactions in the presence of DNA have not been reported so far. We first investigated conditions for the coupling of primary amines to oligonucleotides, using either a nucleophilic attack on chloroacetamide derivatives or a reductive amination on aldehyde-modified DNA. While both methods could be used for the production of secondary amines, the reductive amination approach was generally associated with higher yields and better purity. In a second endeavor, we optimized conditions for the coupling of a diverse set of 501 carboxylic acids to DNA derivatives, carrying primary and secondary amine functions. The coupling efficiency was generally higher for primary amines, compared to secondary amine substituents, but varied considerably depending on the structure of the acids and on the synthetic methods used. Optimal reaction conditions could be found for certain sets of compounds (with conversions >80%), but multiple reaction schemes are needed when assembling large libraries with highly diverse building blocks. The reactions and experimental conditions presented in this article should facilitate the synthesis of future DNA-encoded chemical libraries, while outlining the synthetic challenges that remain to be overcome.

  17. omega-Amino acid:pyruvate transaminase from Alcaligenes denitrificans Y2k-2: a new catalyst for kinetic resolution of beta-amino acids and amines.

    Science.gov (United States)

    Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

    2004-04-01

    Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed omega-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic beta-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for L-beta-amino-n-butyric acid (L-beta-ABA). The enzyme converts various beta-amino acids and amines to the corresponding beta-keto acids and ketones by using pyruvate as an amine acceptor. The apparent K(m) and V(max) for L-beta-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM L-beta-ABA, the apparent K(m) and V(max) for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM D,L-beta-ABA, producing optically pure D-beta-ABA (99% enantiomeric excess) with 53% conversion.

  18. ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

    Science.gov (United States)

    Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

    2004-01-01

    Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for l-β-amino-n-butyric acid (l-β-ABA). The enzyme converts various β-amino acids and amines to the corresponding β-keto acids and ketones by using pyruvate as an amine acceptor. The apparent Km and Vmax for l-β-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM l-β-ABA, the apparent Km and Vmax for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM d,l-β-ABA, producing optically pure d-β-ABA (99% enantiomeric excess) with 53% conversion. PMID:15066855

  19. N-Boc Amines to Oxazolidinones via Pd(II)/Bis-sulfoxide/Brønsted Acid Co-Catalyzed Allylic C–H Oxidation

    Science.gov (United States)

    2015-01-01

    A Pd(II)/bis-sulfoxide/Brønsted acid catalyzed allylic C–H oxidation reaction for the synthesis of oxazolidinones from simple N-Boc amines is reported. A range of oxazolidinones are furnished in good yields (avg 63%) and excellent diastereoselectivities (avg 15:1) to furnish products regioisomeric from those previously obtained using allylic C–H amination reactions. Mechanistic studies suggest the role of the phosphoric acid is to furnish a Pd(II)bis-sulfoxide phosphate catalyst that promotes allylic C–H cleavage and π-allylPd functionalization with a weak, aprotic oxygen nucleophile and to assist in catalyst regeneration. PMID:24999765

  20. N-Boc amines to oxazolidinones via Pd(II)/bis-sulfoxide/Brønsted acid co-catalyzed allylic C-H oxidation.

    Science.gov (United States)

    Osberger, Thomas J; White, M Christina

    2014-08-06

    A Pd(II)/bis-sulfoxide/Brønsted acid catalyzed allylic C-H oxidation reaction for the synthesis of oxazolidinones from simple N-Boc amines is reported. A range of oxazolidinones are furnished in good yields (avg 63%) and excellent diastereoselectivities (avg 15:1) to furnish products regioisomeric from those previously obtained using allylic C-H amination reactions. Mechanistic studies suggest the role of the phosphoric acid is to furnish a Pd(II)bis-sulfoxide phosphate catalyst that promotes allylic C-H cleavage and π-allylPd functionalization with a weak, aprotic oxygen nucleophile and to assist in catalyst regeneration.

  1. Study of the degradation mechanisms of amines used for the capture of CO{sub 2} in industrial fumes; Etude des mecanismes de degradation des amines utilisees pour le captage du CO{sub 2} dans les fumees

    Energy Technology Data Exchange (ETDEWEB)

    Lepaumier, H

    2008-10-15

    Global warming leads to reduce greenhouse gas emissions. Post combustion CO{sub 2} capture with solvent is the most advanced technology to reduce CO{sub 2} emissions in industrial fumes. A major problem associated with chemical absorption of CO{sub 2} using the benchmark ethanolamine (MEA) is solvent degradation through irreversible side reactions with CO{sub 2} and O{sub 2} which leads to numerous harmful impacts to the process: corrosion, solvent loss, foaming, fouling, and viscosity increase. So, developing new amines with higher chemical stability is essential. This work is based on the chemical stability study of 17 different molecules. Their structures have been chosen in order to establish structure-property relationships: alkanolamines, known for gas treatment application (MEA, DEA, MDEA, AMP...), di-amines, and tri-amines without alcohol function. Impact of temperature, CO{sub 2}, and O{sub 2} on degradation has been studied. Strong experimental conditions have been used to observe significant degradation after a 15 days experiment. Separation, identification and quantification of degradation products have been performed by using different testing instructions such as gas chromatography, mass spectrometry, ionic chromatography and NMR. Different mechanisms are proposed to explain most of degradation compounds. Radical reactions (dealkylation, alkylation, ring-closure reactions and piperazinones formation) are involved under O{sub 2} pressure whereas CO{sub 2} induces ionic reactions (dealkylation, alkylation, addition, ring-closure reactions and oxazolidinones or imidazolidinones formation). Large discrepancies of stability are noticed among the different amines. Knowledge of degradation products and reaction mechanisms has thus permitted to establish some relationships between structure and chemical stability: for example, role of the amine function (primary, secondary, tertiary), impact of alkyl chain length between the two amino groups and steric

  2. Terahertz time-domain spectroscopy response of amines and amino acids intercalated smectites in far-infrared region

    Energy Technology Data Exchange (ETDEWEB)

    Janek, M., E-mail: marian.janek@fns.uniba.sk [Comenius University, Faculty of Natural Sciences, Department of Physical and Theoretical Chemistry, Mlynská dolina CH1, SK-84215 Bratislava (Slovakia); Zich, D. [Comenius University, Faculty of Natural Sciences, Department of Physical and Theoretical Chemistry, Mlynská dolina CH1, SK-84215 Bratislava (Slovakia); Naftaly, M., E-mail: mira.naftaly@npl.co.uk [National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW (United Kingdom)

    2014-06-01

    Layered clay minerals from the smectite group with different chemical composition and resulting layer charge (e.g. pyrophyllite, illite, hectorite and montmorillonite) were characterised for their dielectric properties in the far-infrared region using terahertz-time domain spectroscopy (THz-TDS). Samples with distinct cation exchange capacity such as hectorite and montmorillonite were modified using cation exchange reaction with alkylamines or amino acids. The presence of these species in 2D gallery was proved by X-ray diffraction and Fourier transform infrared spectroscopy. The frequency-dependent refractive index of these minerals was determined in the experimentally accessible range of 0.1–3.0 THz (3–100 cm{sup −1}) using THz-TDS. Pristine samples revealed their refractive indices to be 1.82–2.15 at about 1 THz while the modified montmorillonite samples had their refractive indices changed by organic molecules used for their modification to 1.70–2.35 for amines and 1.97–2.36 for amino acids. The presence of organic substances in 2D gallery of clays was detectable despite the relatively high absorption of smectites with magnitude of 100 cm{sup −1}. - Graphical abstract: Display Omitted - Highlights: • “Guest” molecules in “host” layered material were investigated. • Amines and amino-acids were selected as guest molecules. • Natural and synthetic host with smectite phyllosilicate structure were used. • Dielectric properties were investigated by terahertz time domain spectroscopy. • Resonance absorption peaks of guest were detected in far infrared region.

  3. Reactions of Hot Tritium Atoms with Amino Acids; Reactions entre Atomes Chauds de Tritium et Acides Amines; Reaktsii goryachikh atomov tritiya s aminokislotami; Reacciones de Atomos de Tritio Calientes con Aminoacidos

    Energy Technology Data Exchange (ETDEWEB)

    Simonov, E. F.; Nesmejanov, An. N. [Moskovskij Gosudarstvennyj Universitet, Moskva, SSSR (Russian Federation)

    1965-04-15

    de la structure des composes (longueur de la chaine, groupes de substitution fonctionnels). Les auteurs ont etudie le rendement des reactions entre atomes chauds de tritium et acides amines: 1. lorsque la chaine des acides amines s'allonge; 2. lorsque les acides amines ont une chaine carbonee de longueur identique mais possedent des groupes de substitution fonctionnels differents. A cette fin, ils ont irradie des melanges de carbonate de lithium et d'acides a etudier dans un flux de neutrons lents de 0,87 * 10{sup 13}n/cm{sup 2} * s, pendant 15 min. L'analyse a ete faite au moyen d'un appareil de chromatographie gazeuse sur colonne a supports interchangeables (tamis moleculaires, huile de vaseline sur terre d'infusoires) et par chromatographie sur papier. Les donnees obtenues sur la survie a l'irradiation des acides amines en fonction de la longueur de la chaine carbonee semblent contredire une regle fondamentale de radiochimie, selon laquelle la duree de conservation des molecules augmente avec l'allongement de leur chaine, mais elles peuvent s'expliquer par un transfert intramoleculaire de l'excedent d'energie le long de la chaine carbonee - du point d'impact de l'atome chaud au groupe hydroxyle - et la dissipation consecutive de cet excedent; en revanche, bien que l'energie des atomes de tritium de recul depasse l'energie de liaison chimique, cette derniere agit malgre tout sur la conservation des molecules qui ont une chaine carbonee de meme longueur, mais possedent des groupes de substitution differents. (author) [Spanish] Las obras publicadas hasta la fecha no contienen datos sistematicos sobre la interaccion de los atomos de retroceso de tritio con aminoacidos. Tales datos, en conjuncion con los resultados obtenidos para los acidos organicos y las aminas, podrian ayudar a establecer el mecanismo de las reacciones de atomos calientes referido a la estructura de los compuestos (longitud de la cadena, naturaleza de los grupos funcionales). Los autores

  4. Fast and Living Ring-Opening Polymerization of α-Amino Acid N-Carboxyanhydrides Triggered by an "Alliance" of Primary and Secondary Amines at Room Temperature

    KAUST Repository

    Zhao, Wei

    2015-04-13

    A novel highly efficient strategy, based on an "alliance" of primary and secondary amine initiators, was successfully developed allowing the fast and living ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs) at room temperature. (Chemical Equation Presented). © 2015 American Chemical Society.

  5. Fast and Living Ring-Opening Polymerization of α-Amino Acid N-Carboxyanhydrides Triggered by an "Alliance" of Primary and Secondary Amines at Room Temperature

    KAUST Repository

    Zhao, Wei; Gnanou, Yves; Hadjichristidis, Nikolaos

    2015-01-01

    A novel highly efficient strategy, based on an "alliance" of primary and secondary amine initiators, was successfully developed allowing the fast and living ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs) at room temperature. (Chemical Equation Presented). © 2015 American Chemical Society.

  6. General synthesis of C-glycosyl amino acids via proline-catalyzed direct electrophilic alpha-amination of C-glycosylalkyl aldehydes.

    Science.gov (United States)

    Nuzzi, Andrea; Massi, Alessandro; Dondoni, Alessandro

    2008-10-16

    Non-natural axially and equatorially linked C-glycosyl alpha-amino acids (glycines, alanines, and CH2-serine isosteres) with either S or R alpha-configuration were prepared by D- and L-proline-catalyzed (de >95%) alpha-amination of C-glycosylalkyl aldehydes using dibenzyl azodicarboxylate as the electrophilic reagent.

  7. Genome Sequence of Lactobacillus saerimneri 30a (Formerly Lactobacillus sp. Strain 30a), a Reference Lactic Acid Bacterium Strain Producing Biogenic Amines

    NARCIS (Netherlands)

    Romano, Andrea; Trip, Hein; Campbell-Sills, Hugo; Bouchez, Olivier; Sherman, David; Lolkema, Juke S.; Lucas, Patrick M.

    2013-01-01

    Lactobacillus sp. strain 30a (Lactobacillus saerimneri) produces the biogenic amines histamine, putrescine, and cadaverine by decarboxylating their amino acid precursors. We report its draft genome sequence (1,634,278 bases, 42.6% G+C content) and the principal findings from its annotation, which

  8. Observation of new particle formation and measurement of sulfuric acid, ammonia, amines and highly oxidized organic molecules at a rural site in central Germany

    Directory of Open Access Journals (Sweden)

    A. Kürten

    2016-10-01

    Full Text Available The exact mechanisms for new particle formation (NPF under different boundary layer conditions are not known yet. One important question is whether amines and sulfuric acid lead to efficient NPF in the atmosphere. Furthermore, it is not clear to what extent highly oxidized organic molecules (HOMs are involved in NPF. We conducted field measurements at a rural site in central Germany in the proximity of three larger dairy farms to investigate whether there is a connection between NPF and the presence of amines and/or ammonia due to the local emissions from the farms. Comprehensive measurements using a nitrate chemical ionization–atmospheric pressure interface time-of-flight (CI-APi-TOF mass spectrometer, a proton-transfer-reaction mass spectrometer (PTR-MS, particle counters and differential mobility analyzers (DMAs, as well as measurements of trace gases and meteorological parameters, were performed. We demonstrate here that the nitrate CI-APi-TOF is suitable for sensitive measurements of sulfuric acid, amines, a nitrosamine, ammonia, iodic acid and HOMs. NPF was found to correlate with sulfuric acid, while an anti-correlation with RH, amines and ammonia is observed. The anti-correlation between NPF and amines could be due to the efficient uptake of these compounds by nucleating clusters and small particles. Much higher HOM dimer (C19/C20 compounds concentrations during the night than during the day indicate that these HOMs do not efficiently self-nucleate as no nighttime NPF is observed. Observed iodic acid probably originates from an iodine-containing reservoir substance, but the iodine signals are very likely too low to have a significant effect on NPF.

  9. Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia

    Directory of Open Access Journals (Sweden)

    T. Kurtén

    2008-07-01

    Full Text Available We have studied the structure and formation thermodynamics of dimer clusters containing H2SO4 or HSO4 together with ammonia and seven different amines possibly present in the atmosphere, using the high-level ab initio methods RI-MP2 and RI-CC2. As expected from e.g. proton affinity data, the binding of all studied amine-H2SO4 complexes is significantly stronger than that of NH3•H2SO4, while most amine-HSO4 complexes are only somewhat more strongly bound than NH3•HSO4. Further calculations on larger cluster structures containing dimethylamine or ammonia together with two H2SO4 molecules or one H2SO4 molecule and one HSO4 ion demonstrate that amines, unlike ammonia, significantly assist the growth of not only neutral but also ionic clusters along the H2SO4 co-ordinate. A sensitivity analysis indicates that the difference in complexation free energies for amine- and ammonia-containing clusters is large enough to overcome the mass-balance effect caused by the fact that the concentration of amines in the atmosphere is probably 2 or 3 orders of magnitude lower than that of ammonia. This implies that amines might be more important than ammonia in enhancing neutral and especially ion-induced sulfuric acid-water nucleation in the atmosphere.

  10. Characterization of micro-organisms isolated from dairy industry after cleaning and fogging disinfection with alkyl amine and peracetic acid.

    Science.gov (United States)

    Bore, E; Langsrud, S

    2005-01-01

    To characterize micro-organisms isolated from Norwegian dairy production plants after cleaning and fogging disinfection with alkyl amine/peracetic acid and to indicate reasons for survival. Microbial samples were collected from five dairy plants after cleaning and fogging disinfection. Isolates from two of these production plants, which used fogging with alkylamino acetate (plant A), and peracetic acid (plant B), were chosen for further characterization. The sequence of the 16S ribosomal DNA, fatty acid analysis and biochemical characteristics were used to identify isolates. Three isolates identified as Rhodococcus erythropolis, Methylobacterium rhodesianum and Rhodotorula mucilaginosa were isolated from plant A and one Sphingomonas sp. and two M. extorquens from plant B. Different patterns of resistance to seven disinfectants in a bactericidal suspension test and variable degree of attachment to stainless steel were found. The strains with higher disinfectant resistance showed lower degree of attachment than susceptible strains. The study identifies and characterizes micro-organisms present after cleaning and fogging disinfection. Both surface attachment and resistance were shown as possible reasons for the presence of the isolates after cleaning and disinfection. These results contribute to the awareness of disinfectant resistance as well as attachment as mechanisms of survival in dairy industry. It also strengthens the argument of frequent alternation of disinfectants in the food processing industry to avoid the establishment of resistant house strains.

  11. 2-Phenyl-tetrahydropyrimidine-4(1H-ones – cyclic benzaldehyde aminals as precursors for functionalised β2-amino acids

    Directory of Open Access Journals (Sweden)

    Markus Nahrwold

    2009-09-01

    Full Text Available Novel procedures have been developed to condense benzaldehyde effectively with β-amino acid amides to cyclic benzyl aminals. Double carbamate protection of the heterocycle resulted in fully protected chiral β-alanine derivatives. These serve as universal precursors for the asymmetric synthesis of functionalised β2-amino acids containing acid-labile protected side chains. Diastereoselective alkylation of the tetrahydropyrimidinone is followed by a chemoselective two step degradation of the heterocycle to release the free β2-amino acid. In the course of this study, an L-asparagine derivative was condensed with benzaldehyde and subsequently converted to orthogonally protected (R-β2-homoaspartate.

  12. Peptidyl prolyl isomerase Pin1-inhibitory activity of D-glutamic and D-aspartic acid derivatives bearing a cyclic aliphatic amine moiety.

    Science.gov (United States)

    Nakagawa, Hidehiko; Seike, Suguru; Sugimoto, Masatoshi; Ieda, Naoya; Kawaguchi, Mitsuyasu; Suzuki, Takayoshi; Miyata, Naoki

    2015-12-01

    Pin1 is a peptidyl prolyl isomerase that specifically catalyzes cis-trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Theoretical prediction of pKa in methanol: testing SM8 and SMD models for carboxylic acids, phenols, and amines.

    Science.gov (United States)

    Miguel, Elizabeth L M; Silva, Poliana L; Pliego, Josefredo R

    2014-05-29

    Methanol is a widely used solvent for chemical reactions and has solvation properties similar to those of water. However, the performance of continuum solvation models in this solvent has not been tested yet. In this report, we have investigated the performance of the SM8 and SMD models for pKa prediction of 26 carboxylic acids, 24 phenols, and 23 amines in methanol. The gas phase contribution was included at the X3LYP/TZVPP+diff//X3LYP/DZV+P(d) level. Using the proton exchange reaction with acetic acid, phenol, and ammonia as reference species leads to RMS error in the range of 1.4 to 3.6 pKa units. This finding suggests that the performance of the continuum models for methanol is similar to that found for aqueous solvent. Application of simple empirical correction through a linear equation leads to accurate pKa prediction, with uncertainty less than 0.8 units with the SM8 method. Testing with the less expensive PBE1PBE/6-311+G** method results in a slight improvement in the results.

  14. Amino Acid and Biogenic Amine Profile Deviations in an Oral Glucose Tolerance Test: A Comparison between Healthy and Hyperlipidaemia Individuals Based on Targeted Metabolomics

    Directory of Open Access Journals (Sweden)

    Qi Li

    2016-06-01

    Full Text Available Hyperlipidemia (HLP is characterized by a disturbance in lipid metabolism and is a primary risk factor for the development of insulin resistance (IR and a well-established risk factor for cardiovascular disease and atherosclerosis. The aim of this work was to investigate the changes in postprandial amino acid and biogenic amine profiles provoked by an oral glucose tolerance test (OGTT in HLP patients using targeted metabolomics. We used ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry to analyze the serum amino acid and biogenic amine profiles of 35 control and 35 HLP subjects during an OGTT. The amino acid and biogenic amine profiles from 30 HLP subjects were detected as independent samples to validate the changes in the metabolites. There were differences in the amino acid and biogenic amine profiles between the HLP individuals and the healthy controls at baseline and after the OGTT. The per cent changes of 13 metabolites from fasting to the 2 h samples during the OGTT in the HLP patients were significantly different from those of the healthy controls. The lipid parameters were associated with the changes in valine, isoleucine, creatine, creatinine, dimethylglycine, asparagine, serine, and tyrosine (all p < 0.05 during the OGTT in the HLP group. The postprandial changes in isoleucine and γ-aminobutyric acid (GABA during the OGTT were positively associated with the homeostasis model assessment of insulin resistance (HOMA-IR; all p < 0.05 in the HLP group. Elevated oxidative stress and disordered energy metabolism during OGTTs are important characteristics of metabolic perturbations in HLP. Our findings offer new insights into the complex physiological regulation of metabolism during the OGTT in HLP.

  15. Third phase formation in organic solutions in the extraction of mono-acids by tertiary trialcoyl-amines diluted in very slightly polar organic solvents

    International Nuclear Information System (INIS)

    Robaglia, Michele

    1973-01-01

    The phenomena of third phase formation which can occur during the extraction of an acid with a tertiary amine diluted in a low polarity diluent are studied. In the first part a system including water (TnOA - C 6 H 12 - HCl - H 2 O) is compared with an anhydrous system (TnOA - C 6 H 12 - HCl - N 2 ). There are two kinds of gaps. One during amine salification, another one during the extraction of excess acid. The important part of the water content of the organic phase is demonstrated. The presence of water enhances the gaps. The polar water molecules are dissolved inside the tri-octylamine salt micelles. The heavy phase is formed by aggregates, the light phase represents the solubility of the non soluble species in the medium. In the second part are studied the influence of some parameters (like nature of diluent, acid, amine and temperature) on the gaps formation and on the extraction of excess acid and water. In every cases the part played by water remains the same. Finally some comparisons are made between tertiary systems and binary systems which formed them. The binary systems were studied by the mean of crystallization curves. (author) [fr

  16. Profiling of Amino Acids and Their Derivatives Biogenic Amines Before and After Antipsychotic Treatment in First-Episode Psychosis

    Directory of Open Access Journals (Sweden)

    Liisa Leppik

    2018-04-01

    Full Text Available Schizophrenia (SCH is a heterogeneous disorder, deriving from a potential multitude of etiopathogenetic factors. During the past few years there has been an increasing interest in the role of circulating amino acids (AAs and biogenic amines (BAs in the pathophysiology of SCH. In the present study, we aimed to provide an insight into the potential role of alterations in levels of AAs and BAs as well as examine their more specific metabolic shifts in relation to early stage of SCH. We measured 21 AAs and 17 BAs in serum samples of patients with first-episode psychosis (FEP before and after 7-month antipsychotic treatment in comparison to control subjects (CSs. According to multivariate analysis, antipsychotic-naïve FEP patients had significantly higher levels of taurine and spermine, whereas values of proline (Pro, alpha-aminoadipic acid (alpha-AAA, kynurenine (Kyn, valine (Val, tyrosine (Tyr, citrulline (Citr, tryptophan (Trp, and histidine (His were diminished compared to CSs. Increased levels of taurine and spermine, as well as reduced levels of alpha-AAA and Kyn probably reflect the compromised function of N-methyl-D-aspartate (NMDA receptors in patients. The decreased levels of Pro (AA modulating the function of glutamate decarboxylase likely reflect the imbalanced function of gamma-aminobutyric acid (GABA system in the brain of FEP patients. The alterations in ratio between Tyr and phenylalanine (Phe can be taken as a sign of compromised function of dopaminergic system. These metabolic shifts were reinstated by 7-month antipsychotic treatment. Serum metabolic profiles can be regarded as important indicators to investigate clinical course of SCH and treatment response.

  17. Amino Acids from Icy Amines: A Radiation-Chemical Approach to Extraterrestrial Synthesis

    Science.gov (United States)

    Dworkin, J. P.; Moore, M. H.

    2010-01-01

    Detections of amino acids in meteorites go back several decades, with at least 100 such compounds being reported for the Murchison meteorite alone. The presence of these extraterrestrial molecules raises questions as to their formation, abundance, thermal stability, racemization, and possible subsequent reactions. Although all of these topics have been studied in laboratories, such work often involves many variables and unknowns. This has led us to seek out model systems with which to uncover reaction products, test chemical predictions, and sited light on underlying reaction mechanisms. This presentation will describe one such study, focusing on amino-acid formation in ices.

  18. THE EFFECT OF SULPHURIC ACID CONCENTRATION ON SOLVENT EXTRACTION OF ReO4 - BY THE LONG-CHAIN ALIPHATIC TERTIARY AMINES AND ALCOHOLS

    Directory of Open Access Journals (Sweden)

    Aleksander G. Kasikov

    2010-06-01

    Full Text Available The effect of sulphuric acid concentration on solvent extraction of ReO4- by the long-chain aliphatic tertiary amines and alcohols in a wide range of H2SO4 concentrations in initial solutions is discussed. It has been established that the influence of the sulphuric acid concentration on rhenium solvent extraction is largely due to the extraction process mechanism. In the case of the anion-exchange mechanism, ReO4- is best extracted from weakly acidic solutions, whereas when the hydrate-solvate mechanism takes place – from solutions containing 4-7 mole/l H2SO4.

  19. Copper/ascorbic acid dyad as a catalytic system for selective aerobic oxidation of amines

    Czech Academy of Sciences Publication Activity Database

    Šrogl, Jiří; Voltrová, Svatava

    2009-01-01

    Roč. 11, č. 4 (2009), s. 843-845 ISSN 1523-7060 Institutional research plan: CEZ:AV0Z40550506 Keywords : copper * ascorbic acid * oxidative deamination Subject RIV: CC - Organic Chemistry Impact factor: 5.420, year: 2009

  20. Investigation of the ageing effects on phenol-urea-formaldehyde binder and alkanol amine-acid anhydride binder coated mineral fibres

    DEFF Research Database (Denmark)

    Zafar, Ashar; Schjødt-Thomsen, Jan; Sodhi, R.

    2013-01-01

    -ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to identify the chemical changes occurring in the PUF binder coated mineral fibres and alkanol amine-acid anhydride binder coated mineral fibres during that ageing. The samples were aged in a climate......Phenol-Urea-Formaldehyde (PUF) binder coated mineral fibres' mechanical properties have been observed to degrade during ageing at elevated temperatures and humidity, while alkanol amine-acid anhydride binder based mineral fibres exhibited better ageing properties for same duration of ageing. X...... chamber for 7 days at 70 °C and 95% relative humidity. In the case of the PUF binder coated fibres, quantitative XPS measurements showed some significant changes in the atomic composition of the PUF binder coated mineral fibres after ageing, including decreased urea and carbonyl groups concentrations...

  1. N,N-dimethyl hexadecylamine and related amines regulate root morphogenesis via jasmonic acid signaling in Arabidopsis thaliana.

    Science.gov (United States)

    Raya-González, Javier; Velázquez-Becerra, Crisanto; Barrera-Ortiz, Salvador; López-Bucio, José; Valencia-Cantero, Eduardo

    2017-05-01

    Plant growth-promoting rhizobacteria are natural inhabitants of roots, colonize diverse monocot and dicot species, and affect several functional traits such as root architecture, adaptation to adverse environments, and protect plants from pathogens. N,N-dimethyl-hexadecylamine (C16-DMA) is a rhizobacterial amino lipid that modulates the postembryonic development of several plants, likely as part of volatile blends. In this work, we evaluated the bioactivity of C16-DMA and other related N,N-dimethyl-amines with varied length and found that inhibition of primary root growth was related to the length of the acyl chain. C16-DMA inhibited primary root growth affecting cell division and elongation, while promoting lateral root formation and root hair growth and density in Arabidopsis thaliana (Arabidopsis) wild-type (WT) seedlings. Interestingly, C16-DMA induced the expression of the jasmonic acid (JA)-responsive gene marker pLOX2:uidA, while JA-related mutants jar1, coi1-1, and myc2 affected on JA biosynthesis and perception, respectively, are compromised in C16-DMA responses. Comparison of auxin-regulated gene expression, root architectural changes in WT, and auxin-related mutants aux1-7, tir1/afb2/afb3, and arf7-1/arf19-1 to C16-DMA shows that the C16-DMA effects occur independently of auxin signaling. Together, these results reveal a novel class of aminolipids modulating root organogenesis via crosstalk with the JA signaling pathway.

  2. Nitrogen fertilisation increases biogenic amines and amino acid concentrations in Vitis vinifera var. Riesling musts and wines.

    Science.gov (United States)

    Smit, Inga; Pfliehinger, Marco; Binner, Antonie; Großmann, Manfred; Horst, Walter J; Löhnertz, Otmar

    2014-08-01

    Wines rich in biogenic amines can cause adverse health effects to the consumer. Being nitrogen-containing substances, the amount of amines in wines might be strongly influenced by the rate of nitrogen fertiliser application during grape production. The aim of this work was to evaluate the effect of nitrogen fertilisation in the vineyard on the formation of biogenic amines in musts and wines. In a field experiment which compared unfertilised and fertilised (60 and 150 kg N ha(-1)) vines over two separate years, the total amine concentrations in must and wine increased. The latter was due to an increase of individual amines such as ethylamine, histamine, isopentylamine, phenylethylamine and spermidine in the musts and wines with the nitrogen application. Furthermore, the fermentation process increased the concentration of histamine and ethylamine in most of the treatments, while spermidine, spermine and isopentylamine concentrations generally decreased. Throughout both vintages, the concentrations of tyramine and histamine of the investigated musts and wines never reached detrimental levels to the health of non-allergenic people. Nitrogen fertilisation has a significant effect on amines formation in musts and wines. Furthermore, during fermentation, ethylamine and histamine increased while other amines were presumably serving as N sources during fermentation. © 2013 Society of Chemical Industry.

  3. Effect of ethanol amine plasmalogens on Fe-induced peroxidation of arachidonic acid in dipalmitoylphosphatidylcholine vesicles.

    Science.gov (United States)

    Omodeo Salè, M F; Rizzo, A M; Masserini, M

    2000-12-01

    We have investigated the influence of ethanolamine plasmalogens on iron-induced oxidation of arachidonic acid in dipalmitoylphosphatidylcholine (DPPC) vesicles. Lipoperoxidation was induced by the addition of 50 microM FeSO4 and studied above (50 degrees C) and below (15 degrees C) the gel-to liquid transition temperature of the vesicles, at two different pH values (7.4 or 6.4). The extent of peroxidation was measured as thiobarbituric reactive product formed and the influence exerted by ethanolamine plasmalogens (PEPL) in this process was compared to that of dipalmitoylphosphatidylethanolamine (DPPE) and diacylphosphatidylethanolamines (DAPE). The extent of peroxidation of arachidonic acid embedded in DPPC vesicles was similar at the two temperatures and greater at 50 degrees C under acidic conditions. However, the peroxidative process was significantly decreased at 50 degrees C in the presence of PEPL, but not of DPPE or DAPE and the inhibitory effect was enhanced at pH 6.4. The possibility that a different phase distribution of the phospholipids, namely a transition from a lamellar to a hexagonal phase, may play a role in the scavenger effect of ethanolamine plasmalogens is discussed.

  4. Amine-modified hyaluronic acid-functionalized porous silicon nanoparticles for targeting breast cancer tumors

    Science.gov (United States)

    Almeida, Patrick V.; Shahbazi, Mohammad-Ali; Mäkilä, Ermei; Kaasalainen, Martti; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A.

    2014-08-01

    Active targeting of nanoparticles to receptor-overexpressing cancer cells has great potential for enhancing the cellular uptake of nanoparticles and for reducing fast clearance of the nanoparticles from the body. Herein, we present a preparation method of a porous silicon (PSi)-based nanodelivery system for breast cancer targeting, by covalently conjugating a synthesized amide-modified hyaluronic acid (HA+) derived polymer on the surface of undecylenic acid-modified thermally hydrocarbonized PSi (UnTHCPSi) nanoparticles. The resulting UnTHCPSi-HA+ nanoparticles showed relatively small size, reduced polydispersibility, high biocompatibility, improved colloidal and human plasma stability, as well as enhanced cellular interactions and internalization. Moreover, we demonstrated that the enhanced cellular association of UnTHCPSi-HA+ relies on the capability of the conjugated HA+ to bind and consequently target CD44 receptors expressed on the surface of breast cancer cells, thus making the HA+-functionalized UnTHCPSi nanoparticles a suitable and promising nanoplatform for the targeting of CD44-overexpressing breast tumors and for drug delivery.Active targeting of nanoparticles to receptor-overexpressing cancer cells has great potential for enhancing the cellular uptake of nanoparticles and for reducing fast clearance of the nanoparticles from the body. Herein, we present a preparation method of a porous silicon (PSi)-based nanodelivery system for breast cancer targeting, by covalently conjugating a synthesized amide-modified hyaluronic acid (HA+) derived polymer on the surface of undecylenic acid-modified thermally hydrocarbonized PSi (UnTHCPSi) nanoparticles. The resulting UnTHCPSi-HA+ nanoparticles showed relatively small size, reduced polydispersibility, high biocompatibility, improved colloidal and human plasma stability, as well as enhanced cellular interactions and internalization. Moreover, we demonstrated that the enhanced cellular association of Un

  5. NMR chemical shifts in amino acids: Effects of environments, electric field, and amine group rotation

    International Nuclear Information System (INIS)

    Yoon, Young-Gui; Pfrommer, Bernd G.; Louie, Steven G.; Canning, Andrew

    2002-01-01

    The authors present calculations of NMR chemical shifts in crystalline phases of some representative amino acids such as glycine, alanine, and alanyl-alanine. To get an insight on how different environments affect the chemical shifts, they study the transition from the crystalline phase to completely isolated molecules of glycine. In the crystalline limit, the shifts are dominated by intermolecular hydrogen-bonds. In the molecular limit, however, dipole electric field effects dominate the behavior of the chemical shifts. They show that it is necessary to average the chemical shifts in glycine over geometries. Tensor components are analyzed to get the angle dependent proton chemical shifts, which is a more refined characterization method

  6. Oxidation of amines by flavoproteins.

    Science.gov (United States)

    Fitzpatrick, Paul F

    2010-01-01

    Many flavoproteins catalyze the oxidation of primary and secondary amines, with the transfer of a hydride equivalent from a carbon-nitrogen bond to the flavin cofactor. Most of these amine oxidases can be classified into two structural families, the D-amino acid oxidase/sarcosine oxidase family and the monoamine oxidase family. This review discusses the present understanding of the mechanisms of amine and amino acid oxidation by flavoproteins, focusing on these two structural families. Copyright 2009 Elsevier Inc. All rights reserved.

  7. Determination of airborne, volatile amines from polyurethane foams by sorption onto a high-capacity cation-exchange resin based on poly(succinic acid).

    Science.gov (United States)

    Seeber, G; Buchmeiser, M R; Bonn, G K; Bertsch, T

    1998-06-05

    A high-capacity carboxylic acid-functionalized resin prepared by ring-opening metathesis polymerization based on cross-linked endo,endo-poly(norborn-2-ene-5,6-dicarboxylic acid) was used for the sampling of volatile, airborne amines from polyurethane (PU) foams. Six tertiary amines which represent commonly used promotors for the formation of PUs from diisocyanates and polyols, namely pentamethyldiethylenetriamine, diazabicyclooctane, N-methylmorpholine, N-ethylmorphine, 1,4-dimethylpiperazine and N,N-dimethylethanolamine, were sorbed onto the new resin. The sorption behavior of the new material was investigated in terms of loading capacities, the influence of concentration, flow-rate as well as of the amount of resin. Breakthrough curves were recorded from each single component as well as of mixtures thereof. Finally, the resin was used for the sampling of amines evaporating from PU foams applied in buildings. Further information about time dependent concentration profiles were obtained using a combination of GC-MS and Fourier transform IR spectroscopy.

  8. Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Buchweishaija, Joseph

    1997-12-31

    Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

  9. The n-butyl amine TPD measurement of Brönsted acidity for solid catalysts by simultaneous TG/DTG-DTA

    Science.gov (United States)

    Sasca, V.; Avram, Livia; Verdes, Orsina; Popa, A.

    2010-06-01

    The method for Brönsted acidity measurement based on TPD of alkyl amines desorption by gas-chromatography or thermogravimetry was adapted for simultaneous TG/DTG-DTA analysis. The acidity measurements were focused on the 12-tungstophosphoric acid (H 3PW 12O 40) and its salts, especially with Cesium since these posses the highest Brönsted acidity and they are among the most interesting catalysts. The n-butyl amine (NBA) desorption takes place in three steps for Cs xH 3- xPW 12O 40, x = 0-2, and four steps for the Cs 2.5H 0.5PW 12O 40. The steps of desorption correspond to the release of NBA molecules in stages, as NBA or butene molecules resulted from the Hofmann elimination reaction and NH 3 + H 2O formed by decomposition of ammonium salt. The quantities of desorption products, C 4H 8 and NH 3 + H 2O, corresponding to the stages with the maximum desorption rates at 400-420 °C, respectively 560-600 °C, are in the stoichiometric ratio with the Brönsted acidity.

  10. Impact of primary amine group from aminophospholipids and amino acids on marine phospholipids stability: Non-enzymatic browning and lipid oxidation

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2013-01-01

    The main objective of this study was to investigate the oxidative stability and non-enzymatic browning reactions of marine PL in the presence or in the absence of primary amine group from aminophospholipids and amino acids. Marine phospholipids liposomal dispersions were prepared from two authentic......) Strecker derived volatiles, (ii) yellowness index (YI), (iii) hydrophobic and (iv) hydrophilic pyrroles content. The oxidative stability of the samples was assessed through measurement of secondary lipid derived volatile oxidation products. The result showed that the presence of PE and amino acids caused...... the formation of pyrroles, generated Strecker derived volatiles, decreased the YI development and lowered lipid oxidation. The lower degree of lipid oxidation in liposomal dispersions containing amino acids might be attributed to antioxidative properties of pyrroles or amino acids....

  11. Sorption Characteristics of Mixed Molecules of Glutaraldehyde from Water on Mesoporous Acid-Amine Modified Low-Cost Activated Carbon: Mechanism, Isotherm, and Kinetics

    Directory of Open Access Journals (Sweden)

    Mukosha Lloyd

    2015-01-01

    Full Text Available The environmental discharge of inefficiently treated waste solutions of the strong biocide glutaraldehyde (GA from hospitals has potential toxic impact on aquatic organisms. The adsorption characteristics of mixed polarized monomeric and polymeric molecules of GA from water on mesoporous acid-amine modified low-cost activated carbon (AC were investigated. It was found that the adsorption strongly depended on pH and surface chemistry. In acidic pH, the adsorption mechanism was elaborated to involve chemical sorption of mainly hydroxyl GA monomeric molecules on acidic surface groups, while in alkaline pH, the adsorption was elaborated to involve both chemical and physical sorption of GA polymeric forms having mixed functional groups (aldehyde, carboxyl, and hydroxyl on acidic and amine surface groups. The optimum pH of adsorption was about 12 with significant contribution by cooperative adsorption, elucidated in terms of hydrogen bonding and aldol condensation. Freundlich and Dubinin-Radushkevich models were fitted to isotherm data. The adsorption kinetics was dependent on initial concentration and temperature and described by the Elovich model. The adsorption was endothermic, while the intraparticle diffusion model suggested significant contribution by film diffusion. The developed low-cost AC could be used to supplement the GA alkaline deactivation process for efficient removal of residual GA aquatic toxicity.

  12. Effect of γ-Aminobutyric Acid (GABA Producing Bacteria on Rumen Fermentation, Biogenic Amine Production and Anti-oxidation Using Corn Meal as Substrate

    Directory of Open Access Journals (Sweden)

    Bum Seung Ku

    2013-06-01

    Full Text Available The effects and significance of γ-amino butyric acid (GABA producing bacteria (GPB on in vitro rumen fermentation and reduction of biogenic amines (histamine, methylamine, ethylamine, and tyramine using corn meal as a substrate were determined. Ruminal samples collected from ruminally fistulated Holstein cows served as inoculum and corn was used as substrate at 2% dry matter (DM. Different inclusion rates of GPB and GABA were evaluated. After incubation, addition of GPB had no significant effect on in vitro fermentation pH and total gas production, but significantly increased the ammonia nitrogen (NH3-N concentration and reduced the total biogenic amines production (p<0.05. Furthermore, antioxidation activity was improved as indicated by the significantly higher concentration of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px among treated samples when compared to the control (p<0.05. Additionally, 0.2% GPB was established as the optimum inclusion level. Taken together, these results suggest the potential of utilizing GPB as feed additives to improve growth performance in ruminants by reducing biogenic amines and increasing anti-oxidation.

  13. Fluorinated Amine Stereotriads via Allene Amination.

    Science.gov (United States)

    Liu, Lu; Gerstner, Nels C; Oxtoby, Lucas J; Guzei, Ilia A; Schomaker, Jennifer M

    2017-06-16

    The incorporation of fluorine into organic scaffolds often improves the bioactivity of pharmaceutically relevant compounds. C-F/C-N/C-O stereotriad motifs are prevalent in antivirals, neuraminidase inhibitors, and modulators of androgen receptors, but are challenging to install. An oxidative allene amination strategy using Selectfluor rapidly delivers triply functionalized triads of the form C-F/C-N/C-O, exhibiting good scope and diastereoselectivity for all syn products. The resulting stereotriads are readily transformed into fluorinated pyrrolidines and protected α-, β-, and γ-amino acids.

  14. Spectrophotometric study of the complexes of cerium and uranides with diethylenetetraaminepentaacetic acid (DTPA); Contribution a l'etude de la complexation du cerium et des uranides par l'acide diethylenetetraminepentaacetique (DTPA)

    Energy Technology Data Exchange (ETDEWEB)

    Hafez, M B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-03-01

    A spectrophotometric determination was made of the complexes of cerium and uranides in their different degrees of oxidation with diethylenetriaminepentaacetic acid (DTPA). Two physico-chemical states, the ionic and hydrolysis ones, were considered. In the former case, we studied the influence of the pH on the formation of the complex, and whenever the complexes were stable, we determined the molecular ratio and calculated their stability constants. In the latter case, we studied the conditions of solubilization of the precipitate by formation of complexes soluble in water as a function of pH, age of the precipitate and time of precipitate-chelate contact. (authors) [French] Etude spectrophotometrique de la complexation du cerium et des uranides (uranium, neptunium, plutonium et americium) dans leurs differents etats d'oxydation par l'acide diethylenetriaminepentaacetique (DTPA). Deux etats physicochimiques ont retenu notre attention, l'etat ionique et l'etat precipite d'hydrolyse. Dans le premier cas, nous avons etudie l'influence du pH sur la formation du complexe, et dans tous les cas ou le complexe est stable, nous avons determine le rapport moleculaire (5) [element]/[chelatant] du complexe forme et nous avons calcule leurs constantes de stabilite. Dans le deuxieme cas, l'etat de precipite d'hydrolyse, nous avons etudie les conditions de solubilisation du precipite, par formation du complexe, en fonction du pH, de l'age du precipite et du temps de contact precipite - chelatant. (auteurs)

  15. Amine synergism in uranium extraction

    International Nuclear Information System (INIS)

    Rinelli, G.; Abbruzzese, C.

    1977-01-01

    Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)

  16. A simple synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid with a cyclic aminic substituent at the 4α position as possible inhibitors of sialidases.

    Science.gov (United States)

    Rota, Paola; Allevi, Pietro; Agnolin, Irene S; Mattina, Roberto; Papini, Nadia; Anastasia, Mario

    2012-04-14

    A simple protocol for the synthesis of N-perfluoroacylated and N-acylated glycals of neuraminic acid, with a secondary cyclic amine (morpholine or piperidine) at the 4α position, has been set-up, starting from peracetylated N-acetylneuraminic acid methyl ester that undergoes, sequentially to its direct N-transacylation followed by a C-4 amination, a β-elimination, and a selective hydrolysis of the ester functions, without affecting the sensitive perfluorinated amide. This journal is © The Royal Society of Chemistry 2012

  17. Stable isotope N-phosphoryl amino acids labeling for quantitative profiling of amine-containing metabolites using liquid chromatography mass spectrometry.

    Science.gov (United States)

    Zhang, Shanshan; Shi, Jinwen; Shan, Changkai; Huang, Chengting; Wu, Yile; Ding, Rong; Xue, Yuhua; Liu, Wen; Zhou, Qiang; Zhao, Yufen; Xu, Pengxiang; Gao, Xiang

    2017-07-25

    Stable isotope chemical labeling liquid chromatography-mass spectrometry (LC-MS) is a powerful strategy for comprehensive metabolomics profiling, which can improve metabolites coverage and quantitative information for exploration of metabolic regulation in complex biological systems. In the current work, a novel stable isotope N-phosphoryl amino acids labeling strategy (SIPAL) has been successful developed for quantitative profiling of amine-containing metabolites in urine based on organic phosphorus chemistry. Two isotopic reagents, 16 O 2 - and 18 O 2 -N-diisopropyl phosphoryl l-alanine N-hydroxysuccinimide esters ( 16 O/ 18 O-DIPP-L-Ala-NHS), were firstly synthesized in high yields for labeling the amine-containing metabolites. The performance of SIPAL strategy was tested by analyzing standard samples including 20 l-amino acids, 10 d-amino acids and small peptides by using LC-MS. We observed highly efficient and selective labeling for SIPAL strategy within 15 min in a one-pot derivatization reaction under aqueous reaction conditions. The introduction of a neutral phosphate group at N-terminus can increase the proton affinity and overall hydrophobicity of targeted metabolites, leading to the better ionization efficiency in electrospray ionization processes and chromatographic separations of hydrophilic metabolites on reversed-phase column. Furthermore, the chiral metabolites, such as d-amino acids, could be converted to diastereomers after SIPAL and successfully separated on regular reversed-phase column. The chirality of labeled enantiomers can be determined by using different detection methods such as 31 P NMR, UV, and MS, demonstrating the potential application of SIPAL strategy. In addition, absolute quantification of chiral metabolites in biological samples can be easily achieved by using SIPAL strategy. For this purpose, urine samples collected from a healthy volunteer were analyzed by using LC-ESI-Orbitrap MS. Over 300 pairs of different amine

  18. Effects of S-adenosylmethionine decarboxylase, polyamines, amino acids, and weak bases (amines and ammonia) on development and ribosomal RNA synthesis in Xenopus embryos.

    Science.gov (United States)

    Shiokawa, Koichiro; Aso, Mai; Kondo, Takeshi; Takai, Jun-Ichi; Yoshida, Junki; Mishina, Takamichi; Fuchimukai, Kota; Ogasawara, Tsukasa; Kariya, Taro; Tashiro, Kosuke; Igarashi, Kazuei

    2010-02-01

    We have been studying control mechanisms of gene expression in early embryogenesis in a South African clawed toad Xenopus laevis, especially during the period of midblastula transition (MBT), or the transition from the phase of active cell division (cleavage stage) to the phase of extensive morphogenesis (post-blastular stages). We first found that ribosomal RNA synthesis is initiated shortly after MBT in Xenopus embryos and those weak bases, such as amines and ammonium ion, selectively inhibit the initiation and subsequent activation of rRNA synthesis. We then found that rapidly labeled heterogeneous mRNA-like RNA is synthesized in embryos at pre-MBT stage. We then performed cloning and expression studies of several genes, such as those for activin receptors, follistatin and aldolases, and then reached the studies of S-adenosylmethionine decarboxylase (SAMDC), a key enzyme in polyamine metabolism. Here, we cloned a Xenopus SAMDC cDNA and performed experiments to overexpress the in vitro-synthesized SAMDC mRNA in Xenopus early embryos, and found that the maternally preset program of apoptosis occurs in cleavage stage embryos, which is executed when embryos reach the stage of MBT. In the present article, we first summarize results on SAMDC and the maternal program of apoptosis, and then describe our studies on small-molecular-weight substances like polyamines, amino acids, and amines in Xenopus embryos. Finally, we summarize our studies on weak bases, especially on ammonium ion, as the specific inhibitor of ribosomal RNA synthesis in Xenopus embryonic cells.

  19. Study the influence of reacted aliphatic amine series length on its kinetic reaction with dimeric fatty acid C36 and properties of resulted polyamide

    International Nuclear Information System (INIS)

    Al-Mohammad, H.; Falah, A.; Al-Hammoy, M.

    2013-01-01

    Kinetic studies were carried out on the reaction between dimeric fatty acid C 3 6 with 1.3 Diamino propane and 1.4 Diamino butane and 1.6 Diamino hexane and 1.8 Diamino octane in molten phase. The reaction was performed at 145 o C. The polyamidation reaction was found to be on the overall a second order up to 83% conversion for reaction dimeric fatty acid C-36 with 1.3 Diamino propane and 86% conversion for reaction dimeric fatty acid C 3 6 with 1.4 Diamino butane and 87% conversion for reaction dimeric fatty acid C 3 6 with 1.6 Diamino hexane and 1.8 Diamino octane then the reaction order changes to the third order above last conversion. The degree of polymerization,number average molecular weight and weight average molecular weight have been calculated during different times. Their relationships with the times are linear until last conversion. The melting point and thermodynamic constants for melting are determined by use of differential scanning calorimetry DSC. The melting point and thermodynamic constants increase by increasing the length of reacted amine series. (author)

  20. Simultaneous efficient adsorption of Pb2+ and MnO4− ions by MCM-41 functionalized with amine and nitrilotriacetic acid anhydride

    International Nuclear Information System (INIS)

    Chen, Feiyun; Hong, Mingzhu; You, Weijie; Li, Chong; Yu, Yan

    2015-01-01

    Highlights: • MCM-41 was successfully modified with amine and nitrilotriacetic acid anhydride. • The adsorbent can simultaneously remove Pb 2+ and MnO 4 − by adjusting pH of the system. • The maximum adsorption capacities of Pb 2+ and MnO 4 − are 147 mg/g and 156 mg/g. • The absorbent exhibits good regeneration and reusability for 5 cycles use. - Abstract: A novel adsorbent NH 2 /MCM-41/NTAA, capable of simultaneous adsorption of cations and anions from aqueous solution, was prepared by immobilization of amine and nitrilotriacetic acid anhydride (NTAA) onto MCM-41. The structures and properties before and after surface modification were systematically investigated through X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM), nitrogen adsorption–desorption, and infrared spectroscopy (FTIR), thermogravimetry (TGA) and X-ray photoelectron spectroscopy (XPS). They together confirm that the amine and NTAA group were chemically bonded to the internal surface of the mesoporous. The NH 2 /MCM-41/NTAA were used to adsorb Pb 2+ and MnO 4 − in an aqueous solution in a batch system, and the maximum adsorption efficiency was found to occur at pH 5.0 and 3.0, respectively. NH 2 /MCM-41/NTAA exhibit preferable removal of Pb 2+ through electrostatic interactions and chelation, whereas it captures MnO 4 − by means of electrostatic interactions. The experimental data are fitted the Langmuir isotherm model reasonably well, with the maximum adsorption capacity of 147 mg/g for Pb 2+ and of 156 mg/g for MnO 4 − . The adsorption rates of both Pb 2+ and MnO 4 − are found to follow the pseudo-second order kinetics. Furthermore, the NH 2 /MCM-41/NTAA adsorbent performs good recyclability and reusability for 5 cycles use. This study indicates a potential applicability of NH 2 /MCM-41/NTAA as new absorbents for effective simultaneous adsorption of hazardous metal ions and anions from wastewater.

  1. Extraction and separation of molybdenum and vanadium from acidic and alkaline media using tertiary and quaternary amines

    International Nuclear Information System (INIS)

    Stas, J.; Dahdouh, A.; Rizkallah, I.

    2010-01-01

    The extraction of vanadium and molybdenum from alkaline leaching solutions coming from the leaching of fly ash of fired electrical power stations by tri-n dodecylamine (TDA) and metyl trioctyl ammonium chloride (QA) in the presence of octanol-2 as modifier in kerosene has been investigated. Some parameters influencing the extraction process have been studied (agitation time, octanol-2 percentage in the organic phase, pH of the aqueous phase, concentration of TDA and QA, concentration of vanadium in the aqueous phase and temperature). It has been shown that the extraction capacity of both V and Mo by TDA increases by decreasing the pH of the aqueous phase and reaches a maximum extraction at pH=2. The concentration of TDA plays an important role on the separation selectivity between these two elements, where the selectivity of Mo vs V (S M o, v=[Mo] o rg/[V] o rg) increases with the decrease of TDA concentration to reach a maximum selectivity value of S M o, v = 0.37 for [TDA]=1.5 M. It has been also shown that, whatever vanadium concentration in the aqueous phase, molybdenum will be first extracted, then the remaining free TDA will be occupied by vanadium. Concerning the quaternary amine QA, the pH value of the aqueous phase plays an important role in the separation process between vanadium and molybdenum, where the value of the selectivity of V vs Mo (S v , Mo=[V] o rg/[Mo] o rg) is maximal for pH>8 and the pH=8.5 is the best value which permit a good separation between these two elements at QA concentration equal to 6%, especially at high vanadium concentration. It is very important to note that for low vanadium concentration and at pH=1.5 the value of the selectivity of Mo vs V (S M o,v) increases with increasing Mo concentration in the aqueous phase which enable us the separation between these two elements under these experimental conditions, where Mo will be much more extracted than vanadium. The stripping of vanadium and molybdenum from the loaded organic

  2. Hydrolysis and rearrangement of phthalamic acid derivatives and assessment of their potential as prodrug forms for amines

    DEFF Research Database (Denmark)

    Bundgaard, Hans; Steffansen, Bente

    1990-01-01

    Although it is well-known that N-substituted phthalamic acid derivatives are readily hydrolyzed in acidic aqueous solution due to intramolecular catalysis by the neighbouring carboxy group, sparse information is available on the degradation behaviour in neutral solutions. A recent publication [5]...

  3. Direct measurement of the interaction energy between solids and gases--3. Comparison of the calorimetric titration method with the amine titration method for the determination of acid strength distribution of the silica-alumina surface

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, H.; Masuda, T.; Tsutsumi, K.; Takahashi, H.

    1978-07-01

    Comparison of the calorimetric titration method with the amine titration method for the determination of acid strength distribution of the silica-alumina surface was carried out for a catalyst containing 13% by wt alumina and evacuated at 400/sup 0/C at 0.00001 mm Hg for five hours. The heats of adsorption of ammonia on silica-alumina poisoned with Hammett indicators of 8.2 to 3.3 pK/sub a/ were also measured to obtain the relation between the dissociation constant of the acid (pK/sub a/) and the heat of adsorption. At pK/sub a/ values of -5.6 and +3.3, the differential heats of adsorption were 76.1 and 55.1 kj/mole, respectively. The number of acid sites calculated from the heat vs. adsorbed-amount curve was about twice as large as that determined by amine titration. The discrepancy is discussed.

  4. Comparison of γ-aminobutyric acid and biogenic amine content of different types of ewe’s milk cheese produced in Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    Gavina Manca

    2015-06-01

    Full Text Available The bioactive compounds γ-aminobutyric acid (GABA and biogenic amines (BA, together with protein-free amino acids, were measured by high-performance liquid chromatography in ewe’s milk cheeses produced in Sardinia with different technological traits. The study included three types of cheese: Pecorino Sardo PDO, Pecorino and Casu Marzu. Farmhouse Casu Marzu and Pecorino showed GABA content (maximum levels: 1001.3 and 378.1 mg 100 g–1 respectively that had never been found so high in cheese before, suggesting that these types of cheese present ideal conditions to produce GABA. These two types of cheese also showed high levels of BA (their total maximum levels were 1035.7 and 288.0 mg 100 g–1 respectively. Pearson correlation analysis detected significant correlation between GABA and the main BA present in the cheeses (tyramine, cadaverine and putrescine, suggesting that the factors affecting the production of GABA are the same as those influencing BA formation.

  5. Poly (amido amine) and nano-calcium phosphate bonding agent to remineralize tooth dentin in cyclic artificial saliva/lactic acid

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Kunneng [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Weir, Michael D.; Reynolds, Mark A. [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Zhou, Xuedong [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Li, Jiyao, E-mail: jiyaoliscu@163.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Xu, Hockin H.K., E-mail: hxu@umaryland.edu [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore County, MD 21250 (United States)

    2017-03-01

    The objectives of this study were to develop a novel method to remineralize dentin lesions, and investigate the remineralization effects of poly (amido amine) (PAMAM) dendrimer plus a bonding agent with nanoparticles of amorphous calcium phosphate (NACP) in a cyclic artificial saliva/lactic acid environment for the first time. Dentin lesions were produced via phosphoric acid. Four groups were tested: (1) dentin control, (2) dentin with PAMAM, (3) dentin with NACP bonding agent, and (4) dentin with PAMAM plus NACP bonding agent. Specimens were treated with cyclic artificial saliva/lactic acid. The remineralized dentin was examined using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), hardness and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). NACP bonding agent yielded a dentin shear bond strength similar to commercial controls (Prime & Bond NT, Dentsply; Scotchbond Multi-purpose, 3M) (p > 0.1). Increasing NACP in bonding agent from 0 to 40% did not affect bond strength. NACP bonding agent neutralized the acid and released Ca ions with concentrations of 4 to 20 mmol/L, and P ions of 2 to 9 mmol/L. PAMAM or NACP bonding agent alone achieved slight remineralization. The PAMAM + NACP group achieved the greatest dentin remineralization p < 0.05). At 20 days, PAMAM + NACP increased the hardness of pre-demineralized dentin to reach the normal dentin hardness (p > 0.1). In conclusion, superior remineralization of PAMAM + NACP bonding agent was demonstrated for the first time. PAMAM + NACP bonding agent induced dentin remineralization under acid challenge, when conventional remineralization methods such as PAMAM alone did not work well. The novel PAMAM + NACP bonding agent method is promising to improve the longevity of resin-dentin bonds, inhibit caries, and protect teeth. - Highlights: • PAMAM induced moderate remineralization for dentin in artificial saliva/lactic acid. • Acid challenge reduced the

  6. Poly (amido amine) and nano-calcium phosphate bonding agent to remineralize tooth dentin in cyclic artificial saliva/lactic acid

    International Nuclear Information System (INIS)

    Liang, Kunneng; Weir, Michael D.; Reynolds, Mark A.; Zhou, Xuedong; Li, Jiyao; Xu, Hockin H.K.

    2017-01-01

    The objectives of this study were to develop a novel method to remineralize dentin lesions, and investigate the remineralization effects of poly (amido amine) (PAMAM) dendrimer plus a bonding agent with nanoparticles of amorphous calcium phosphate (NACP) in a cyclic artificial saliva/lactic acid environment for the first time. Dentin lesions were produced via phosphoric acid. Four groups were tested: (1) dentin control, (2) dentin with PAMAM, (3) dentin with NACP bonding agent, and (4) dentin with PAMAM plus NACP bonding agent. Specimens were treated with cyclic artificial saliva/lactic acid. The remineralized dentin was examined using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), hardness and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). NACP bonding agent yielded a dentin shear bond strength similar to commercial controls (Prime & Bond NT, Dentsply; Scotchbond Multi-purpose, 3M) (p > 0.1). Increasing NACP in bonding agent from 0 to 40% did not affect bond strength. NACP bonding agent neutralized the acid and released Ca ions with concentrations of 4 to 20 mmol/L, and P ions of 2 to 9 mmol/L. PAMAM or NACP bonding agent alone achieved slight remineralization. The PAMAM + NACP group achieved the greatest dentin remineralization p < 0.05). At 20 days, PAMAM + NACP increased the hardness of pre-demineralized dentin to reach the normal dentin hardness (p > 0.1). In conclusion, superior remineralization of PAMAM + NACP bonding agent was demonstrated for the first time. PAMAM + NACP bonding agent induced dentin remineralization under acid challenge, when conventional remineralization methods such as PAMAM alone did not work well. The novel PAMAM + NACP bonding agent method is promising to improve the longevity of resin-dentin bonds, inhibit caries, and protect teeth. - Highlights: • PAMAM induced moderate remineralization for dentin in artificial saliva/lactic acid. • Acid challenge reduced the

  7. Hydrogen generation from formic acid catalyzed by a metal complex under amine-free and aqueous conditions

    KAUST Repository

    Huang, Kuo-Wei

    2018-01-04

    The present invention provides a class of catalyst compounds that can safely and effectively release hydrogen gas from a chemical substrate without producing either noxious byproducts or byproducts that will deactivate the catalyst. The present invention provides catalysts used to produce hydrogen that has a satisfactory and sufficient lifespan (measured by turnover number (TON)), that has stability in the presence of moisture, air, acid, or impurities, promote a rapid reaction rate, and remain stable under the reaction conditions required for an effective hydrogen production system. Described herein are compounds for use as catalysts, as well as methods for producing hydrogen from formic acid and/or a formate using the disclosed catalysts. The methods include contacting formic acid and/or a formate with a catalyst as described herein, as well as methods of producing formic acid and/or a formate using the disclosed catalyst and methods for generating electricity using the catalysts described herein.

  8. Hydrogen generation from formic acid catalyzed by a metal complex under amine-free and aqueous conditions

    KAUST Repository

    Huang, Kuo-Wei; Guan, Chao; Pan, Yupeng; Hu, Jinsong; Li, Huaifeng

    2018-01-01

    invention provides catalysts used to produce hydrogen that has a satisfactory and sufficient lifespan (measured by turnover number (TON)), that has stability in the presence of moisture, air, acid, or impurities, promote a rapid reaction rate, and remain

  9. Extraction of sulphates by long chain amines

    International Nuclear Information System (INIS)

    Boirie, Ch.

    1959-05-01

    The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [fr

  10. Evaluation of amine inhibitors for suitability as crevice buffering agents

    International Nuclear Information System (INIS)

    Jayaweera, P.; Hettiarachchi, S.

    1994-03-01

    This report describes the results of a research effort to evaluate the suitability of some selected amines and amino acids as a crevice-buffering agents in pressurized water reactor (PWR) steam generators. The amines may be useful for buffering acid crevices, and the amino acids, because they contain both acidic and basic groups, may be useful for acidic and caustic crevices. Five commercially available amines and two amino acids were studied during this research. The study involved (1) the hydrolysis of these commercially available amines and amino acids, including measurement of their kinetics of decomposition, in simulated steam generator bulk water at 290 C, and (2) determination of their thermal stability in a simulated crevice environment. The study showed that, although the high-molecular-weight amines undergo hydrothermal decomposition, they have a better buffering capacity than their low-molecular-weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the crevice solution by as much as 2.84 and to 4.24 units in the experimental setup used in this program. It was concluded that polyamines provide excellent buffering of the simulated crevice environment at 290 C and morpholine remains the best low-molecular-weight amine investigated. However, detailed volatility studies of the amines were not considered in this work. Such data would be needed before in-plant testing to ensure that the amines can concentrate in steam generator crevices to the levels assumed in this study

  11. Sillica Gel-Amine from Geothermal Sludge

    Science.gov (United States)

    Muljani, S.; Pujiastuti, C.; Wicaksono, P.; Lutfianingrum, R.

    2018-01-01

    Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

  12. Threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy of simple organic acids, aldehydes, ketones and amines

    International Nuclear Information System (INIS)

    Yencha, Andrew J; Malins, Andrew E R; Siggel-King, Michele R F; Eypper, Marie; King, George C

    2009-01-01

    We have initiated a research program to investigate the ionization behavior of some simple organic molecules containing the carboxyl group (R 2 C=O), where R could be H, OH, NH 2 , or CH 3 or other aliphatic or aromatic carbon groups, using threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy. We report here on the simplest organic acid, formic acid, and two simple aldehydes: acetaldehyde and the simplest unsaturated aldehyde, 2-propenal (acrolein). The objective of this study was to characterize the valence cationic states of these molecules with vibrational structural resolution.

  13. Oxidative versus Non-oxidative Decarboxylation of Amino Acids: Conditions for the Preferential Formation of Either Strecker Aldehydes or Amines in Amino Acid/Lipid-Derived Reactive Carbonyl Model Systems.

    Science.gov (United States)

    Zamora, Rosario; León, M Mercedes; Hidalgo, Francisco J

    2015-09-16

    Comparative formation of both 2-phenylethylamine and phenylacetaldehyde as a consequence of phenylalanine degradation by carbonyl compounds was studied in an attempt to understand if the amine/aldehyde ratio can be changed as a function of reaction conditions. The assayed carbonyl compounds were selected because of the presence in the chain of both electron-donating and electron-withdrawing groups and included alkenals, alkadienals, epoxyalkenals, oxoalkenals, and hydroxyalkenals as well as lipid hydroperoxides. The obtained results showed that the 2-phenylethylamine/phenylacetaldehyde ratio depended upon both the carbonyls and the reaction conditions. Thus, it can be increased using electron-donating groups in the chain of the carbonyl compound, small amounts of carbonyl compound, low oxygen content, increasing the pH, or increasing the temperature at pH 6. Opposed conditions (use of electron-withdrawing groups in the chain of the carbonyl compound, large amounts of carbonyl compound, high oxygen contents, low pH values, and increasing temperatures at low pH values) would decrease the 2-phenylethylamine/phenylacetaldehyde ratio, and the formation of aldehydes over amines in amino acid degradations would be favored.

  14. Alteration of amino acid and biogenic amine metabolism in hepatobiliary cancers : Findings from a prospective cohort study

    NARCIS (Netherlands)

    Stepien, Magdalena; Duarte-Salles, Talita; Fedirko, Veronika; Floegel, Anne; Barupal, Dinesh Kumar; Rinaldi, Sabina; Achaintre, David; Assi, Nada; Tjønneland, Anne; Overvad, Kim; Bastide, Nadia; Boutron-Ruault, Marie Christine; Severi, Gianluca; Kühn, Tilman; Kaaks, Rudolf; Aleksandrova, Krasimira; Boeing, Heiner; Trichopoulou, Antonia; Bamia, Christina; Lagiou, Pagona; Saieva, Calogero; Agnoli, Claudia; Panico, Salvatore; Tumino, Rosario; Naccarati, Alessio; Bueno-de-Mesquita, H. B.; Peeters, Petra H.; Weiderpass, Elisabete; Quirós, J. Ramón; Agudo, Antonio; Sánchez, María José; Dorronsoro, Miren; Gavrila, Diana; Barricarte, Aurelio; Ohlsson, Bodil; Sjöberg, Klas; Werner, Mårten; Sund, Malin; Wareham, Nick; Khaw, Kay Tee; Travis, Ruth C.; Schmidt, Julie A.; Gunter, Marc; Cross, Amanda; Vineis, Paolo; Romieu, Isabelle; Scalbert, Augustin; Jenab, Mazda

    2016-01-01

    Perturbations in levels of amino acids (AA) and their derivatives are observed in hepatocellular carcinoma (HCC). Yet, it is unclear whether these alterations precede or are a consequence of the disease, nor whether they pertain to anatomically related cancers of the intrahepatic bile duct (IHBC),

  15. Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3-thiophene acetic acid) conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, T.; Magyar, M.; Nagy, L. [Department of Medical Physics and Informatics, University of Szeged, H-6720 Szeged (Hungary); Nemeth, Z.; Hernadi, K. [Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged (Hungary); Endrodi, B.; Bencsik, G.; Visy, Cs. [Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged (Hungary); Horvath, E.; Magrez, A.; Forro, L. [Institute of Physics of Complex Matter, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

    2012-12-15

    A large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio-nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3-thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Free amino acids, biogenic amines, and ammonium profiling in tobacco from different geographical origins using microwave-assisted extraction followed by ultra high performance liquid chromatography.

    Science.gov (United States)

    Cai, Kai; Xiang, Zhangmin; Li, Hongqin; Zhao, Huina; Lin, Yechun; Pan, Wenjie; Lei, Bo

    2017-12-01

    This work describes a rapid, stable, and accurate method for determining the free amino acids, biogenic amines, and ammonium in tobacco. The target analytes were extracted with microwave-assisted extraction and then derivatized with diethyl ethoxymethylenemalonate, followed by ultra high performance liquid chromatography analysis. The experimental design used to optimize the microwave-assisted extraction conditions showed that the optimal extraction time was 10 min with a temperature of 60°C. The stability of aminoenone derivatives was improved by keeping the pH near 9.0, and there was no obvious degradation during the 80°C heating and room temperature storage. Under optimal conditions, this method showed good linearity (R 2 > 0.999) and sensitivity (limits of detection 0.010-0.081 μg/mL). The extraction recoveries were between 88.4 and 106.5%, while the repeatability and reproducibility ranged from 0.48 to 5.12% and from 1.56 to 6.52%, respectively. The newly developed method was employed to analyze the tobacco from different geographical origins. Principal component analysis showed that four geographical origins of tobacco could be clearly distinguished and that each had their characteristic components. The proposed method also showed great potential for further investigations on nitrogen metabolism in plants. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Biosynthesised ZnO : Dy3+ nanoparticles: Biodiesel properties and reusable catalyst for N-formylation of aromatic amines with formic acid

    Science.gov (United States)

    Reddy Yadav, L. S.; Raghavendra, M.; Sudheer Kumar, K. H.; Dhananjaya, N.; Nagaraju, G.

    2018-04-01

    ZnO nanoparticles doped with trivalent dysprosium ions (Dy3+) were prepared through the green combustion technique using E. tirucalli plant latex as a fuel. The fundamental and optical properties of the samples are examined via the X-ray diffraction, FTIR, UV-visible analytical methods and morphology by scanning electron microscope and transmission electron microscope. Rietveld refinement results show that the ZnO : Dy3+ were crystallized in the wurtzite hexagonal structure with space group P63mc (No. 186). The average particle size of ZnO : Dy3+ prepared with the different concentration of latex was found to be in the range 30-38nm, which is also confirmed by TEM analysis. A rapid and convenient method for the one-pot preparation of N-formamide derivatives aromatic amines and amino acid esters has been developed using Dy3+ doped ZnO as a catalytic agent. This method provides an efficient and much improved modification over reported protocols regarding yield, clean and work-up procedure milder reaction conditions. In this work, Pongamiapinnata oil was recycled for the preparation of biodiesel via Dy3+ doped ZnO as a catalytic agent.

  18. Relative quantification of enantiomers of chiral amines by high-throughput LC–ESI-MS/MS using isotopic variants of light and heavy L-pyroglutamic acids as the derivatization reagents

    International Nuclear Information System (INIS)

    Mochizuki, Toshiki; Taniguchi, Sayuri; Tsutsui, Haruhito; Min, Jun Zhe; Inoue, Koichi; Todoroki, Kenichiro; Toyo’oka, Toshimasa

    2013-01-01

    Highlights: ► Development of chiral labeling reagent for a pair of amine enantiomers. ► High-throughput analysis of diastereomers by UPLC–ESI-MS/MS. ► Highly efficient separation and detection of the enantiomers. ► Differential analysis of enantiomer ratio in different sample groups using light and heavy labeling reagents. -- Abstract: L-Pyroglutamic acid (L-PGA) was evaluated as a chiral labeling reagent for the enantioseparation of chiral amines in terms of separation efficiency by reversed-phase chromatography and detection sensitivity by ESI-MS/MS. Several amines and amino acid methyl esters were used as typical representatives of the chiral amines. Both enantiomers of the chiral amines were easily labeled with L-PGAs at room temperature for 60 min in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1-hydroxy-1H-benzotriazole as the activation reagents. The resulting diastereomers were completely separated by reversed-phase chromatography using the small particle (1.7 μm) ODS column (Rs = 1.6–6.8). A highly sensitive detection at a low-fmol level (1–4 fmol) was also obtained from the multiple reaction monitoring (MRM) chromatograms. Therefore, a high-throughput determination was achieved by the present UPLC–ESI-MS/MS method. An isotope labeling strategy using light and heavy L-PGAs for the differential analysis of chiral amines in different sample groups was also proposed in this paper. As a model study, the differential analysis of the R and S ratio of 1-phenylethylamine (PEA) was performed according to the proposed procedure using light and heavy reagents, i.e., L-PGA and L-PGA-d 5 . The R/S ratio of PEA, spiked at the different concentrations in rat plasma, was almost similar to the theoretical values. Consequently, the proposed strategy using light and heavy chiral labeling reagents seems to be applicable for the differential analysis of chiral amine enantiomers in different sample groups, such as healthy persons and

  19. Kinetic and analytical study on precipitation reactions with 110AgNO3 of some di(β-chloroethyl)amine derivatives and hydrochlorides with esters of N-(p-aminobenzoyl)-L-aspartic acid as carriers from dimethylformamide - water solution

    International Nuclear Information System (INIS)

    Cecal, Al.; Sunel, V.; Ghimiciu, L.

    1983-01-01

    The kinetics of precipitation reactions with 110 AgNO 3 of some di(β-chloroethyl) amine derivates and hydrochlorides with esters of N-(p-aminobenzoyl)-L-aspartic acid as carriers in dimethylformamide-water mixture, were studied. The rate constants of these reactions were of the order of 10 -4 lxmol -1 xmin -1 . The concentrations of the corresponding hydrochloride solutions were measured by radiometric titration with 110 AgNO 3 solution of given concentration. (author)

  20. Tris(2-aminoethyl)amine-based α-branched fatty acid amides - Synthesis of lipids and comparative study of transfection efficiency of their lipid formulations.

    Science.gov (United States)

    Erdmann, Nicole; Wölk, Christian; Schulze, Ingo; Janich, Christopher; Folz, Manuela; Drescher, Simon; Dittrich, Matthias; Meister, Annette; Vogel, Jürgen; Groth, Thomas; Dobner, Bodo; Langner, Andreas

    2015-10-01

    The synthesis of a new class of cationic lipids, tris(2-aminoethyl)amine-based α-branched fatty acid amides, is described resulting in a series of lipids with specific variations in the lipophilic as well as the hydrophilic part of the lipids. In-vitro structure/transfection relationships were established by application of complexes of these lipids with plasmid DNA (pDNA) to different cell lines. The α-branched fatty acid amide bearing two tetradecyl chains and two lysine molecules (T14diLys) in mixture with the co-lipid 1,2-di-[(9Z)-octadec-9-enoyl]-sn-glycero-3-phosphoethanolamine (DOPE) (1/2, n/n) exhibits effective pDNA transfer in three different cell lines, namely Hep-G2, A549, and COS-7. The presence of 10% serum during lipoplex incubation of the cells did not affect the transfection efficiency. Based on that, detailed investigations of the complexation of pDNA with the lipid formulation T14diLys/DOPE 1/2 (n/n) were carried out with respect to particle size and charge using dynamic light scattering (DLS), ζ-potential measurements, and transmission electron microscopy (TEM). Additionally, the lipoplex uptake was investigated by confocal laser scanning microscopy (CLSM). Overall, lipoplexes prepared from T14diLys/DOPE 1/2 (n/n) offer large potential as lipid-based polynucleotide carriers and further justify advanced examinations. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Amine Measurements in Boreal Forest Air

    Science.gov (United States)

    Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

    2015-04-01

    Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

  2. Solvent-extraction and purification of uranium(VI) and molybdenum(VI) by tertiary amines from acid leach solutions

    International Nuclear Information System (INIS)

    La Gamma, Ana M.G.; Becquart, Elena T.; Chocron, Mauricio

    2008-01-01

    Considering international interest in the yellow-cake price, Argentina is seeking to exploit new uranium ore bodies and processing plants. A study of similar plants would suggest that solvent- extraction with Alamine 336 is considered the best method for the purification and concentration of uranium present in leaching solutions. In order to study the purification of these leach liquors, solvent-extraction tests under different conditions were performed with simulated solutions which containing molybdenum and molybdenum-uranium mixtures. Preliminary extraction tests carried out on mill acid-leaching liquors are also presented. (authors)

  3. Amphetamine, 3,4-methylenedioxymethamphetamine, lysergic acid diethylamide, and metabolites of the catecholamine neurotransmitters are agonists of a rat trace amine receptor.

    Science.gov (United States)

    Bunzow, J R; Sonders, M S; Arttamangkul, S; Harrison, L M; Zhang, G; Quigley, D I; Darland, T; Suchland, K L; Pasumamula, S; Kennedy, J L; Olson, S B; Magenis, R E; Amara, S G; Grandy, D K

    2001-12-01

    The trace amine para-tyramine is structurally and functionally related to the amphetamines and the biogenic amine neurotransmitters. It is currently thought that the biological activities elicited by trace amines such as p-tyramine and the psychostimulant amphetamines are manifestations of their ability to inhibit the clearance of extracellular transmitter and/or stimulate the efflux of transmitter from intracellular stores. Here we report the discovery and pharmacological characterization of a rat G protein-coupled receptor that stimulates the production of cAMP when exposed to the trace amines p-tyramine, beta-phenethylamine, tryptamine, and octopamine. An extensive pharmacological survey revealed that psychostimulant and hallucinogenic amphetamines, numerous ergoline derivatives, adrenergic ligands, and 3-methylated metabolites of the catecholamine neurotransmitters are also good agonists at the rat trace amine receptor 1 (rTAR1). These results suggest that the trace amines and catecholamine metabolites may serve as the endogenous ligands of a novel intercellular signaling system found widely throughout the vertebrate brain and periphery. Furthermore, the discovery that amphetamines, including 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy"), are potent rTAR1 agonists suggests that the effects of these widely used drugs may be mediated in part by this receptor as well as their previously characterized targets, the neurotransmitter transporter proteins.

  4. Automatisation en flux continu du dosage enzymatique de l'acide malique des vins

    Directory of Open Access Journals (Sweden)

    Aline Lonvaud-Funel

    1980-12-01

    The authors report a continuous flow technic for enzymatic analysis of malic acid in wines. In order to minimize the effect of interfering compounds, the NADH content is read at 570 nm. This method preserve the specificity and sensibility of the enzymatic manual assay.

  5. A comparative study of three ternary complexes prepared in different mixing orders of siRNA/redox-responsive hyperbranched poly (amido amine/hyaluronic acid

    Directory of Open Access Journals (Sweden)

    Chen CJ

    2012-07-01

    Full Text Available Cheng-Jun Chen,1 Zhi-Xia Zhao,1 Jian-Cheng Wang,1 En-Yu Zhao,1 Ling-Yan Gao,1 Shu-Feng Zhou,2 Xiao-Yan Liu,1 Wan-Liang Lu,1 Qiang Zhang11State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutics, School of Pharmaceutical Science, Peking University, Beijing, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USAAbstract: In this study, a novel redox-responsive hyperbranched poly(amido amine (named PCD was synthesized and used as a cationic polymer to form a ternary complex with small interfering RNA (siRNA and hyaluronic acid (HA for siRNA delivery. Here, it is hypothesized that different mixing orders result in different assembly structures, which may affect the siRNA delivery efficiency. To investigate the effects of mixing orders on siRNA delivery efficiency in two human breast cancer cell lines, three ternary complexes with different mixing orders of siRNA/PCD/HA were prepared and characterized: mixing order I (initially prepared siRNA/PCD binary complex further coated by negatively charged HA, mixing order II (initially prepared HA/PCD binary complex further incubated with siRNA, and mixing order III (initially prepared siRNA/HA mixture further electrostatically compacted by positively charged PCD. With an optimized siRNA/PCD/HA charge ratio of 1/20/16, the particle sizes and zeta potentials of these ternary complexes were 124.8 nm and 27.3 mV (mixing order I, 147.5 nm and 29.9 mV (mixing order II, and 128.8 nm and 19.4 mV (mixing order III. Also, the effects on stability, cellular uptake, and gene silencing efficiency of siRNA formulated in ternary complexes with different mixing orders were investigated. The results showed that mixing orders I and III displayed better siRNA transfection and protection than mixing order II in human breast cancer MCF-7 and MDA-MB-231 cells. More interesting, at the siRNA/PCD/HA charge ratio of 1/20/16, the

  6. Yb(OTf){sub 3}-catalyzed one-pot three component synthesis for tertiary amines

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bum Seok; Kim, Ji Hye; Nam, Tae Kyu; Jang, Doo Ok [Dept. of Chemistry, Yonsei University, Wonju (Korea, Republic of)

    2015-07-15

    Tertiary amine functionality is found in many natural bioactive products such as alkaloids, amino acids, nucleic acids, pharmaceuticals, and agrochemicals. Tertiary amines have also been used as building blocks for nitrogen-containing organic compounds and synthetic polymers. A one-pot method for direct reductive amination of aldehydes has been developed to synthesize tertiary amines using HMDS as a nitrogen source in the presence of Yb(OTf ){sub 3}. With a stoichiometric amount of HMDS, the reaction afforded the desired tertiary amines without competitive reduction of the parent carbonyl compounds. This reaction offers a convenient and efficient protocol for synthesizing aromatic and aliphatic tertiary amines under mild reaction conditions.

  7. General Dialdehyde Click Chemistry for Amine Bioconjugation.

    Science.gov (United States)

    Elahipanah, Sina; O'Brien, Paul J; Rogozhnikov, Dmitry; Yousaf, Muhammad N

    2017-05-17

    The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research. In particular, primary amines are a ubiquitous functional group found in biological systems as free amino acids, as key side chain lysines in proteins, and in signaling molecules and metabolites and are also present in many natural product classes. Due to its abundance, the primary amine is the most convenient functional group handle in molecules for ligation to other molecules for a broad range of applications that impact all scientific fields. Because of the primary amine's central importance in synthetic chemistry, acid-base chemistry, redox chemistry, and biology, many methods have been developed to efficiently react with primary amines, including activated carboxylic acids, isothiocyanates, Michael addition type systems, and reaction with ketones or aldehydes followed by in situ reductive amination. Herein, we introduce a new traceless, high-yield, fast click-chemistry method based on the rapid and efficient trapping of amine groups via a functionalized dialdehyde group. The click reaction occurs in mild conditions in organic solvents or aqueous media and proceeds in high yield, and the starting dialdehyde reagent and resulting dialdehyde click conjugates are stable. Moreover, no catalyst or dialdehyde-activating group is required, and the only byproduct is water. The initial dialdehyde and the resulting conjugate are both straightforward to characterize, and the reaction proceeds with high atom economy. To demonstrate the broad scope of this new click

  8. Influence of nature, concentration and pH of buffer acid-base system on rate determining step of the electrochemiluminescence of Ru(bpy){sub 3} {sup 2+} with tertiary aliphatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Pastore, Paolo [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy)]. E-mail: paolo.pastore@unipd.it; Badocco, Denis [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy); Zanon, Francesco [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy)

    2006-07-28

    The electrogenerated chemiluminescence (ECL) of Ru(bpy){sub 3} {sup 2+} (bpy 2,2'-bipyridyl) with tertiary aliphatic amines as co-reactants, was theoretically and experimentally studied as a function of the pre-equilibria involved in the ammonium proton lost and in relation to the nature of the rate determining step. Transient potential steps were used with a 3-mm glassy carbon disk electrode or carbon fiber ultramicroelectrodes array to investigate emission behavior in a variety of aqueous solution types, containing phosphate, tartrate and phthalate acid-base systems at differing pH values. The emission of Ru(bpy){sub 3} {sup 2+} resulting from the reaction with n-tripropylamine (TPrA), tri-isobutylamine (TisoBuA), n-tributylamine (TBuA), methyl-di-n-propylamine (MeDPrA) and triethylamine (TEtA) in varying acid-base media was interpreted on the basis of the quoted pre-equilibria, ammonium pK {sub a} being known. The nature of the rate determining steps changes depending on pH. Above pH {approx} 5 the amine neutral radical formation is the rate determining step and, is independent of pH with rate constant close to 10{sup 3} s{sup -1}; below pH {approx} 5 the rate determining step becomes the deprotonation of the ammonium ion, operated by different bases present in solution. Different amines in the same acid-base system showed analogous ECL behavior, conditioned by the chosen acid base system. A single amine in different acid-base systems showed different kinetic behaviors, due to the dissociation constants of the chosen buffers. The concentration of the acid-base system also played an important role and influenced emission intensity and shape. ECL emission were simulated by finite difference methods, implementing a previously proposed mechanism by including the relevant pre-equilibria. Simulation may also give estimates of the pK {sub a} values of the ammonium ions. An ion pair formation between R{sub 3}N{center_dot} {sup +} and the mostly charged species

  9. Influence of nature, concentration and pH of buffer acid-base system on rate determining step of the electrochemiluminescence of Ru(bpy)32+ with tertiary aliphatic amines

    International Nuclear Information System (INIS)

    Pastore, Paolo; Badocco, Denis; Zanon, Francesco

    2006-01-01

    The electrogenerated chemiluminescence (ECL) of Ru(bpy) 3 2+ (bpy 2,2'-bipyridyl) with tertiary aliphatic amines as co-reactants, was theoretically and experimentally studied as a function of the pre-equilibria involved in the ammonium proton lost and in relation to the nature of the rate determining step. Transient potential steps were used with a 3-mm glassy carbon disk electrode or carbon fiber ultramicroelectrodes array to investigate emission behavior in a variety of aqueous solution types, containing phosphate, tartrate and phthalate acid-base systems at differing pH values. The emission of Ru(bpy) 3 2+ resulting from the reaction with n-tripropylamine (TPrA), tri-isobutylamine (TisoBuA), n-tributylamine (TBuA), methyl-di-n-propylamine (MeDPrA) and triethylamine (TEtA) in varying acid-base media was interpreted on the basis of the quoted pre-equilibria, ammonium pK a being known. The nature of the rate determining steps changes depending on pH. Above pH ∼ 5 the amine neutral radical formation is the rate determining step and, is independent of pH with rate constant close to 10 3 s -1 ; below pH ∼ 5 the rate determining step becomes the deprotonation of the ammonium ion, operated by different bases present in solution. Different amines in the same acid-base system showed analogous ECL behavior, conditioned by the chosen acid base system. A single amine in different acid-base systems showed different kinetic behaviors, due to the dissociation constants of the chosen buffers. The concentration of the acid-base system also played an important role and influenced emission intensity and shape. ECL emission were simulated by finite difference methods, implementing a previously proposed mechanism by including the relevant pre-equilibria. Simulation may also give estimates of the pK a values of the ammonium ions. An ion pair formation between R 3 N· + and the mostly charged species present in solution is hypothesized to explain the contradictory experimental

  10. Amines, Astrocytes and Arousal

    OpenAIRE

    Bazargani, N.; Attwell, D.

    2017-01-01

    Amine neurotransmitters, such as noradrenaline, mediate arousal, attention, and reward in the CNS. New data suggest that, from flies to mammals, a major mechanism for amine transmitter action is to raise astrocyte [Ca2+]i and release gliotransmitters that modulate neuronal activity and behavior.

  11. Partial amino acid sequence of the branched chain amino acid aminotransferase (TmB) of E. coli JA199 pDU11

    International Nuclear Information System (INIS)

    Feild, M.J.; Armstrong, F.B.

    1987-01-01

    E. coli JA199 pDU11 harbors a multicopy plasmid containing the ilv GEDAY gene cluster of S. typhimurium. TmB, gene product of ilv E, was purified, crystallized, and subjected to Edman degradation using a gas phase sequencer. The intact protein yielded an amino terminal 31 residue sequence. Both carboxymethylated apoenzyme and [ 3 H]-NaBH-reduced holoenzyme were then subjected to digestion by trypsin. The digests were fractionated using reversed phase HPLC, and the peptides isolated were sequenced. The borohydride-treated holoenzyme was used to isolate the cofactor-binding peptide. The peptide is 27 residues long and a comparison with known sequences of other aminotransferases revealed limited homology. Peptides accounting for 211 of 288 predicted residues have been sequenced, including 9 residues of the carboxyl terminus. Comparison of peptides with the inferred amino acid sequence of the E. coli K-12 enzyme has helped determine the sequence of the amino terminal 59 residues; only two differences between the sequences are noted in this region

  12. Fertilisation continue des Oxisols acides non humifères du

    Directory of Open Access Journals (Sweden)

    Nzabonihankuye G.

    1998-01-01

    Full Text Available Crop rotation system of maize and beans, established at Rubona (Rwanda from 1984 to 1992, was used to evaluate different types and rates of fertilizers in improving the productivity of acid Oxisols. Continuous cropping of maize followed by beans for a period of 8 years gave no yield in control plots. Asingle application of 2 t per ha of lime increased significantly (p = .01 the soil pH, Ca2+ content, cationic exchange capacity, and decreased the level of the exchangeable aluminium. This quantity of lime when applied every two years for a period of eight years led to overliming. The application of more than 8 t per ha of fresh farmyard manure (annually, combined to 300 kg per ha of NPK 17:17:17 (every six months significantly improved soil organic C and crop production at Rubona. The high rate (35 t per ha of fresh manure or the combination of “lime, manure and NPK fertilizers” gave the best crop performance. Ten tons of farmyard manure (dry matter per ha and per year seems to be the minimum acceptable amount which can effectively substitute for inorganic fertilizers.

  13. Complexation des acides aminés basiques arginine, histidine et lysine avec l'ADN plasmidique en solution aqueuse : participation à la capture de radicaux sous irradiation X à 1,5 keV

    Science.gov (United States)

    Tariq Khalil, Talat; Taillefumier, Baptiste; Boulanouar, Omar; Mavon, Christophe; Fromm, Michel

    2016-09-01

    L'environnement chimique de l'ADN en situation biologique est complexe notam-ment en raison de la présence d'histones, protéines nucléaires, associées en quantité approximativement égales à l'ADN pour former la chromatine. Les histones possèdent de nombreux radicaux basiques arginine et lysine chargés positivement et dont la majorité se trouve sur les chaînes émergentes, l'ADN présente quant à lui des charges négatives sur ses groupements phosphates localisés tout au long de la double hélice. Dans cette étude, la complexité de la structure de la chromatine nucléaire est dans un premier temps mimée en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois acides aminés basiques, Arg, His, Lys, qui, mis à part His, sont protonés au pH physiologique. Ces acides aminés libres en solution sont réputés être des capteurs efficaces de radicaux libres, notamment pour le radical hydroxyle, conférant ainsi un pouvoir protecteur vis-à-vis des effets indirects sur l'ADN en situation d'exposition aux rayonnements ionisants. A concentration fixée, les capacités de capture des acides aminés libres, σ, pour le radical hydroxyle sont typiquement les suivantes σHis ≈σArg > σLys (σLys ≈ 0,1 × σArg). Nous avons mesuré les taux de cassures simple brin par plasmide et par Gray (χ) lors d'expositions de solutions aqueuses de complexes [acide aminé - ADN plasmidique] aux rayons X ultra-mous (1,5 keV). A concentrations égales, les trois acides aminés complexés et présents en large excès ne manifestent pas une capacité de protection de l'ADN proportionnelle à leur capacité de capture libre et en solution ; on trouve en effet des taux de cassures dans l'ordre suivant χHis > χArg > χLys (χLys ≈ 0,01 χArg). Après avoir détaillé le mode opératoire de ces mesures, nous analyserons sur des bases bibliographiques, les modes spécifiques d'interaction des acides aminés basiques avec l'ADN. La sp

  14. Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

    Science.gov (United States)

    Gündüz, T; Kiliç, E; Cakirer, O

    1996-05-01

    Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

  15. Impact of restricted amoxicillin/clavulanic acid use on Escherichia coli resistance--antibiotic DU90% profiles with bacterial resistance rates: a visual presentation.

    Science.gov (United States)

    Mimica Matanovic, Suzana; Bergman, Ulf; Vukovic, Dubravka; Wettermark, Björn; Vlahovic-Palcevski, Vera

    2010-10-01

    High use of amoxicillin/clavulanic acid (AMC) at the University Hospital Osijek (Croatia) contributed to high rates of resistance in Enterobacteriaceae, in particular Escherichia coli (50%). Thus, in order to decrease bacterial resistance, AMC use was restricted. We present results of the restriction on resistance amongst antibiotics accounting for 90% of antibiotic use [drug utilisation 90% (DU90%)]. Data were analysed on antibiotic use and microbiological susceptibility of E. coli during two 9-month periods, before and after the restriction of AMC use. Drug use was presented as numbers of defined daily doses (DDDs) and DDDs/100 bed-days. Resistance of E. coli to antibiotics was presented as percentages of isolated strains in the DU90% segment. Use of AMC was 16 DDDs/100 bed-days or 30% of all antibiotics before the intervention. Use of AMC fell to 2 DDDs/100 bed-days or 4% after the intervention, and resistance of E. coli fell from 37% to 11%. In conclusion, restricted use of AMC resulted in a significant decrease of E. coli resistance. DU90% resistance profiles are simple and useful tools in highlighting problems in antibiotic use and resistance but may also be useful in long-term follow-up of antibiotic policy. Copyright 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  16. The Determination of Sub-Microgram Quantities, of Amino Acids with H{sup 3}- and C{sup 1}4-Labelled 1-Fluoro-2.4 Dinitrobenzene; Determination d'acides amines en quantites inferieures au microgramme a l'aide de 1-fluoro-2,4-dinitrobenzen e marque au {sup 3}H et au {sup 14}C; Podschet submikrogrammnykh kolichestv aminokislot pri pomoshchi 2 : 4 dinitroftor'enzola, mechennogo H{sup 3} i C{sup 14}; Determinacion de cantidades de aminoacidos inferiores al microgramo por medio de 1-fluoro-2,4-dinitrobenceno marcado con {sup 3}H y {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Beale, D; Whitehead, J K [Middlesex Hospital Medical School, London (United Kingdom)

    1962-01-15

    A method of isotope derivation analysis is described for the estimation of amino acids at levels as low as 10{sup -5} {mu}M in protein hydrolysates. 1-fluoro-2.4-dinitrobenzene-H{sup 3} (G) was synthesized from bromobenzene-H{sup 3} (G), and 1-fluoro- 2.4-dinitrobenzene-C{sup 14} (G) was prepared from chlorobenzene-C{sup 14} (G). The method of analysis involves the treatment of the mixture of amino acids with the tritiated reagent (specific activity 12,8{mu}c/{mu}-equivalent) in alkaline solution followed by the addition of known activities (6000 dpm) of C{sup 14}-labelled 2.4-dinitto phenyl derivatives. After solvent extraction the reaction mixture is separated into its constituent dinitro phenyl derivatives by two-way paper chromatography, and the H{sup 3} and C{sup 14} contente of each spot are determined by combustion and gas counting. The H{sup 3} count gives a measure of the amount of DNP derivative of amino acid isolated from the original mixture, and the C{sup 14} count gives a measure pf losses ihcurred during the analysis. The results obtained from the analysis of ({mu}g of hydrolyzed insulin are in good agreement with values obtained by derivative analysis with H{sup 3} and C{sup 14}-labelled acetic anhydride and by ion exchange resin chromatography. [French] Les auteurs decrivent une methode d'analyse par derivation isotopique permettant d'evaluer des quantites d'acides amines aussi faibles que 10{sup -5} {mu}M dans des hydrolysats de proteine. Le 1-fluoro-2,4-dinitrobenzene-{sup 3}H (G) a ete prepare par synthese a partir du bromobenzene-{sup 3}H (U), et le 1-fluoro-2,4-dinitrobenzene-{sup 14}C (G) a partir du chlorobenzene-{sup 14}C (U). Cette methode d'analyse implique le traitement du melange d'acides amines par le reactif tritie (activite specifique: 12,8 p.c par microequivalent) en solution alcaline, suivi.de l'addition de derives du dinitro-2,4-phenyl e marque au {sup 14}C d'activite connue (6000 dpm). Apres extraction par solvant, les derives du

  17. Cysteic acid and taurine synthesis from sulphate in the chick embryo; Synthese de l'acide cysteique et de la taurine a partir du sulfate dans l'oeuf embryonne de poule

    Energy Technology Data Exchange (ETDEWEB)

    Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-07-01

    The formation of taurine from sulphate was studied in the chick embryo using the radioisotopes of: sulphur, carbon and hydrogen. The following reactions occur: 1) reduction of sulphate to sulphite; 2) fixation of the sulphite on a carbon chain with an amino group, resulting from desulphydration of L-cysteine, which leads to the formation of L-cysteic acid; 3) decarboxylation of L-cysteic acid. Reaction (1) takes place only in the endo-dermal cells of the yolk sac; reaction (2) in these same cells and in the yolk; reaction (3) is general, localized in the yolk sac, in the yolk as well as in the tissues of the embryo itself. The enzyme which catalyses reaction (2) has been purified; the coenzyme is pyridoxal phosphate. The desulphydration of cysteine by this enzyme is a reversible reaction. In non-physiological conditions of concentration and temperature, pyridoxal phosphate catalyses in the presence of metallic ions, the desulphydration of cysteine and the formation of cysteic acid from sulphite. (author) [French] On a montre que la formation de taurine a partir de sulfate dans I'oeuf embryonne de poule, etudiee a l'aide des radioisotopes, du soufre, du carbone et de l'hydrogene, correspond aux reactions suivantes: 1) reduction du sulfate en sulfite; 2) fixation du sulfite sur une chaine tricarbonee et aminee provenant de la desulfhydration de la L-cysteine, fixation conduisant a la formation d'acide L-cysteique; 3) decarboxylation de l'acide L-cysteique. La reaction (1) a lieu uniquement dans les cellules de l'endoderme du sac vitellin; la reaction (2) dans les memes cellules et dans le vitellus; la reaction (3) est plus generale, elle est localisee dans le sac vitellin, dans le vitellus et dans les tissus de l'embryon. L'enzyme qui catalyse la reaction (2) a ete purifie; il possede le phosphate de pyridoxal comme coenzyme. La desulfhydration de la cysteine par cet enzyme est une reaction reversible. Dans les conditions non physiologiques de concentration et de

  18. Amine Functionalized Porous Network

    KAUST Repository

    Eddaoudi, Mohamed; Guillerm, Vincent; Weselinski, Lukasz Jan; Alkordi, Mohamed H.; Mohideen, Mohamed Infas Haja; Belmabkhout, Youssef

    2015-01-01

    Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

  19. Amine Functionalized Porous Network

    KAUST Repository

    Eddaoudi, Mohamed

    2015-05-28

    Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

  20. Modification Of Poly(glycidyl Methacrylate) Grafted Onto Crosslinked Pvc With Tertiary Amine Group And Use For Removing Acidic Dyes From Water

    OpenAIRE

    Yorgun, Gülden

    2009-01-01

    In this study, glycidylmethacrylate is grafted onto partially dehydrochlorinated poly(vinyl chloride) (DHPVC) using ATRP method and polymerization kinetics of the reaction is studied. Then, the polymeric resin was interacted with excess of diethylamine, giving a tertiary amine containing sorbent. Surface initiated polymerizations have been widely used to overcome inadequate properties of poly(vinylchloride) (PVC). Epoxy group is one of the most important type to be integrated into polymers. T...

  1. Simultaneous Determination of Food-Related Biogenic Amines and Precursor Amino Acids Using in Situ Derivatization Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction by Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Wang, Renjun; Wei, Na; Sun, Jing; Dang, Jun; Chen, Guang; Liu, Zhiqiang; Zhu, Shuyun; You, Jinmao

    2016-11-02

    A simple, rapid, sensitive, selective, and environmentally friendly method, based on in situ derivatization ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) using multiple reaction monitoring (MRM) mode has been developed for the simultaneous determination of food-related biogenic amines and amino acids. A new mass-spectrometry-sensitive derivatization reagent 4'-carbonyl chloride rosamine (CCR) was designed, synthesized, and first reported. Parameters and conditions of in situ DUADLLME and UHPLC-MS/MS were optimized in detail. Under the optimized conditions, the in situ DUADLLME was completed speedily (within 1 min) with high derivatization efficiencies (≥98.5%). With the cleanup and concentration of microextraction step, good analytical performance was obtained for the analytes. The results showed that this method was accurate and practical for quantification of biogenic amines and amino acids in common food samples (red wine, beer, wine, cheese, sausage, and fish).

  2. A Mild and Green Route for Regio-selective Amination of Oxiranes Using Nanomagnetic Supported Ferrous Ion as a Solid Lewis Acid Catalyst in Water

    Directory of Open Access Journals (Sweden)

    Fariborz Mansouri

    2016-07-01

    Full Text Available A mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of Mn(II, Fe(II, Co(II, Ni(II, Cu(II and Zn(II cations onto the surface of hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp. Among six magnetically recoverable catalytic systems denoted as [γ-Fe2O3@HAp-MII], the catalyst in which M designated as Fe(II showed the best efficiency as well as regio-selectivity in amination of oxiranes under an ambient reaction condition. A wide variety of aromatic and aliphatic amines were reacted with epoxides using magnetically separable iron catalyst to give the corresponding amino alcohols in excellent yields and selectivities in water as solvent at room temperature. In addition, recovery of the catalyst was successfully carried out in subsequent runs without any decrease in activity even after 5 runs. High regio-selectivity toward terminal ring-opening, efficient catalyst reusability using simple magnetic separation, high yields, simplicity in operation and diversity for various substrates are of advantages of this study.

  3. Extraction of uranyl sulfate with primary amine

    International Nuclear Information System (INIS)

    Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

    1984-01-01

    PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

  4. Enhanced Adsorption of p-Arsanilic Acid from Water by Amine-Modified UiO-67 as Examined Using Extended X-ray Absorption Fine Structure, X-ray Photoelectron Spectroscopy, and Density Functional Theory Calculations.

    Science.gov (United States)

    Tian, Chen; Zhao, Jian; Ou, Xinwen; Wan, Jieting; Cai, Yuepeng; Lin, Zhang; Dang, Zhi; Xing, Baoshan

    2018-03-20

    p-Arsanilic acid ( p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high adsorption affinity are urgently needed. Herein, amine-modified UiO-67 (UiO-67-NH 2 ) metal-organic frameworks (MOFs) were synthesized, and their adsorption affinities toward p-ASA were 2 times higher than that of the pristine UiO-67. Extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results revealed adsorption through a combination of As-O-Zr coordination, hydrogen bonding, and π-π stacking, among which As-O-Zr coordination was the dominant force. Amine groups played a significant role in enhancing the adsorption affinity through strengthening the As-O-Zr coordination and π-π stacking, as well as forming new adsorption sites via hydrogen bonding. UiO-67-NH 2 s could remove p-ASA at low concentrations (<5 mg L -1 ) in simulated natural and wastewaters to an arsenic level lower than that of the drinking water standard of World Health Organization (WHO) and the surface water standard of China, respectively. This work provided an emerging and promising method to increase the adsorption affinity of MOFs toward pollutants containing both organic and inorganic moieties, via modifying functional groups based on the pollutant structure to achieve synergistic adsorption effect.

  5. Analytical methods used in plutonium purification cycles by trilaurylamine; Methodes analytiques utilisees dans les cycles de purification du plutonium par la trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    The utilisation of trilaurylamine as a solvent extractant for the purification of plutonium has entailed to perfect a set of analytical methods which involves, various techniques. The organic impurities of the solvent can be titrated by gas-liquid chromatography. The titration of the main degradation product, the di-laurylamine, can be accomplished also by spectro-colorimetry. Potentiometry is used for the analysis of the different salts of amine-nitrate-sulfate-bisulfate as also the extracted nitric acid. The determination of the nitrate in aqueous phase is carried out by constant current potentiometry. The range of application, the accuracy and the procedure of these analysis are related in the present report. (author) [French] L'utilisation de la trilaurylamine comme solvant d'extraction pour la purification du plutonium a necessite la mise au point d'un ensemble de methodes analytiques qui ressortent de techniques diverses. Les impuretes organiques du solvant peuvent etre dosees par chromatographie gaz-liquide. Le dosage du principal produit de degradation, la dilaurylamine, peut egalement etre effectue par spectrocolorimetrie. La potentiometrie est utilisee pour les analyses des differents sels d'amine: nitrate, sulfate, bisulfate, ainsi que de l'acide nitrique extrait. La determination des nitrates en phase aqueuse est executee par potentiometrie a courant impose. Le domaine d'application, la precision et le mode operatoire de ces analyses sont indiques dans le present rapport. (auteur)

  6. Some aspects of sulphite metabolism in plants; Quelques aspects du metabolisme du sulfite chez les vegetaux

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Milan, Hernan

    1958-05-15

    As sulphite appears to be an intermediate substance in the degradation of sulphur-containing amino acids, and has an important metabolic role, notably for plants, this research thesis aims at comparing transformations which may occur for a same chemical compound (the sulphite) in various organisms belonging to different species or kingdoms. More particularly, the author studied the formation of sulphite in vegetal tissues, and the oxidisation of sulphite into sulfate within these tissues. In vitro experiments have been performed with oat, while in vivo experiments have been performed on tobacco plants [French] Le sulfite apparait comme une substance intermediaire de la degradation des acides amines soufres. Son role dans la biosynthese de certains d'entre eux, problematique chez les mammiferes, est certain chez les oiseaux, qui, a cet egard, se comportent comme des autotrophes partiels, puisqu'ils reduisent le sulfate en sulfite. On s'apercoit ainsi qu'un degre d'evolution moindre confere au sulfite une importance metabolique plus grande. On peut s'attendre a trouver chez les vegetaux un role encore accru pour le sulfite. Le present travail entre dans ce cadre d'etudes comparees des transformations que peut subir un meme type de compose chimique: le sulfite, dans divers organismes appartenant a des especes ou a des regnes differents. Les donnees acquises exposees ici auront trait aux deux points suivants: I - La formation du sulfite dans les tissus vegetaux, II - L'oxydation dans ces tissus, du sulfite en sulfate. L'avoine nous a servi comme materiel de depart pour les experiences faites in vitro. Cette plante presente en effet l'avantage de se bien cultiver en toutes saisons, de se broyer facilement, et d'etre depourvue au maximum de mucilages, de resines, substances genantes pour l'analyse ulterieure. Les essais faits in vivo, ont mis en oeuvre des plants de tabac, qui permettent une nutrition par le petiole ou par la tige particulierement aisee.

  7. A fast, reliable, ultra high performance liquid chromatography method for the simultaneous determination of amino acids, biogenic amines and ammonium ions in cheese, using diethyl ethoxymethylenemalonate as a derivatising agent.

    Science.gov (United States)

    Redruello, Begoña; Ladero, Victor; Cuesta, Isabel; Álvarez-Buylla, Jorge R; Martín, María Cruz; Fernández, María; Alvarez, Miguel A

    2013-08-15

    Derivatisation treatment with diethyl ethoxymethylenemalonate followed by ultra-HPLC allowed the simultaneous quantification of 22 amino acids, 7 biogenic amines and ammonium ions in cheese samples in under 10 min. This is the fastest elution time ever reported for such a resolution. The proposed method shows good linearity (R(2)>0.995) and sensitivity (detection limit 0.08-3.91 μM; quantification limit <13.02 μM). Intra- and inter-day repeatability ranged from 0.35% to 1.25% and from 0.85% to 5.2%, respectively. No significant effect of the cheese matrix was observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Efficient one-pot, four-component synthesis of N,N-dibenzyl-N-{1-[5-(3-aryl-1,3,4-oxadiazol-2-yl]cyclobutyl}amine derivatives from the reaction of (isocyanoiminotriphenylphosphorane, dibenzylamine, an aromatic carboxylic acid and cyclobutanone

    Directory of Open Access Journals (Sweden)

    Shajari Nahid

    2012-01-01

    Full Text Available Four-component reaction of cyclobutanone, dibenzylamine and (Nisocyanimino triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and under neutral conditions to afford N,N-dibenzyl-N-{1-[5-(3-aryl-1,3,4-oxadiazol-2-yl]cyclobutyl}amine derivatives in high yields.

  9. Inhibitory action of an heterocyclic organic compound containing amine group for copper corrosion in 5,0 M nitric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    El-Naggar, M.M.; Abdallah, M. [Benha Univ., Benha (Egypt). Chemistry Dept., Faculty of Science

    2000-10-01

    An heterocyclic organic compound containing amine group namely: 3-mercaptomethyl-4amino-5-hydroxy-1, 2, 4-triazole compound 1{sub a} was tested as a new inhibitor for copper corrosion in 5.0 M HNO{sub 3} solution. It proved to have a high value of inhibition efficiency (> 99.9%) at an inhibitor concentration of {>=} 2.5 x 10{sup -}3 M. A parallelism is established between the results obtained from weight loss, thermometric and galvanostatic polarization techniques. The high protective effect of compound I{sub a} is related to the decomposition of HNO{sub 2} formed through the autocatalytic cycle. The decomposition of HNO{sub 2} could be attributed to its reaction with the adsorbed inhibitor amine group. Furthermore, the results indicated that compound I{sub a} provides long-term protection and behaves as a mixed inhibitor type with a predominant cathodic effectiveness. [Italian] E' stato valutato, quale nuovo inibitore della corrosione del rame in soluzione 5.0 M di HNO{sub 3}, un composto organico eterociclico contenente un amino gruppo, chiamato: 3-mercaptometil-4amino-5-idrossi-1, 2, 4-triazolo composto I{sub a}. Questi, ad una concentrazione {>=} 2.5 x 10{sup -}3 M, ha dimostrato di possedere un elevato valore di efficienza di inibizione (> 99.9%). E' stato stabilito un parallelismo tra i risultati ottenuti dalla perdita di peso, da misure termometriche e di polarizzazione galvanostatica. L'elevato effetto protettivo del composto I{sub a} e' correlato alla decomposizione dell'HNO{sub 2} formatosi attraverso il ciclo autocatalitico. La decomposizione di HNO{sub 2} puo' essere attribuita alla sua reazione con il gruppo inibitore aminico adsorbito. Inoltre, i risultati indicano che il composto I{sub a} fornisce una protezione a lungo termine e si comporta come un inibitore di tipo misto con una predominante efficienza catodica.

  10. Amine functionalized nanodiamond promotes cellular adhesion, proliferation and neurite outgrowth

    International Nuclear Information System (INIS)

    Hopper, A P; Dugan, J M; Gill, A A; Haycock, J W; Claeyssens, F; Fox, O J L; May, P W

    2014-01-01

    In this study, we report the production of amine functionalized nanodiamond. The amine functionalized nanodiamond forms a conformal monolayer on a negatively charged surface produced via plasma polymerization of acrylic acid. Nanodiamond terminated surfaces were studied as substrates for neuronal cell culture. NG108-15 neuroblastoma-glyoma hybrid cells were successfully cultured upon amine functionalized nanodiamond coated surfaces for between 1 and 7 d. Additionally, primary dorsal root ganglion (DRG) neurons and Schwann cells isolated from Wistar rats were also successfully cultured over a period of 21 d illustrating the potential of the coating for applications in the treatment of peripheral nerve injury. (paper)

  11. Characterization of particulate amines

    International Nuclear Information System (INIS)

    Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

    1979-01-01

    The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

  12. Detection of cometary amines in samples returned by Stardust

    Science.gov (United States)

    Glavin, D. P.; Dworkin, J. P.; Sandford, S. A.

    2008-02-01

    The abundances of amino acids and amines, as well as their enantiomeric compositions, were measured in samples of Stardust comet-exposed aerogel and foil using liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC-FD/ToF-MS). A suite of amino acids and amines including glycine, L-alanine, β-alanine (BALA), γ-amino-n-butyric acid (GABA), ɛ-amino-n-caproic acid (EACA), ethanolamine (MEA), methylamine (MA), and ethylamine (EA) were identified in acid-hydrolyzed, hot-water extracts of these Stardust materials above background levels. With the exception of MA and EA, all other primary amines detected in cometexposed aerogel fragments C2054,4 and C2086,1 were also present in the flight aerogel witness tile that was not exposed to the comet, indicating that most amines are terrestrial in origin. The enhanced relative abundances of MA and EA in comet-exposed aerogel compared to controls, coupled with MA to EA ratios (C2054,4: 1.0 ± 0.2; C2086,1: 1.8 ± 0.2) that are distinct from preflight aerogels (E243-13C and E243-13F: 7 ± 3), suggest that these volatile amines were captured from comet Wild 2. MA and EA were present predominantly in an acid-hydrolyzable bound form in the aerogel, rather than as free primary amines, which is consistent with laboratory analyses of cometary ice analog materials. It is possible that Wild 2 MA and EA were formed on energetically processed icy grains containing ammonia and approximately equal abundances of methane and ethane. The presence of cometary amines in Stardust material supports the hypothesis that comets were an important source of prebiotic organic carbon and nitrogen on the early Earth.

  13. Effect of Bronsted Acids and Bases, and Lewis Acid (Sn(2+)) on the Regiochemistry of the Reaction of Amines with Trifluoromethyl-β-diketones: Reaction of 3-Aminopyrrole to Selectively Produce Regioisomeric 1H-Pyrrolo[3,2-b]pyridines.

    Science.gov (United States)

    De Rosa, Michael; Arnold, David; Hartline, Douglas; Truong, Linda; Verner, Roman; Wang, Tianwei; Westin, Christian

    2015-12-18

    Reaction of 3-aminopyrrole (as its salt) with trifluoromethyl-β-diketones gave γ-1H-pyrrolo[3,2-b]pyridines via reaction at the less reactive carbonyl group. The trifluoromethyl group increased the electrophilicity of the adjacent carbonyl group and decreased the basicity of the hydroxyl group of the CF3 amino alcohol formed. This amino alcohol was formed faster, but its subsequent dehydration to the β-enaminone was slow resulting in the preferential formation of the γ-regioisomer. Reaction of 4,4,4-trifluoro-1-phenyl-1,3-butadione with 3-aminopyrrole was carried out using a series of 6 amine buffers. Yields of the α-1H-pyrrolo[3,2-b]pyridine increased as the pKa of the amine buffer decreased. Surprisingly the yield went down at higher pKas. There was a change in mechanism as the reaction mixture became more basic. With strong amines trifluoromethyl-β-diketones were present mainly or completely as the enolate. Under reductive conditions (3-nitropyrrole/Sn/AcOH/trifluoromethyl-β-diketone) the α-1H-pyrrolo[3,2-b]pyridine was the major product as a result of Lewis acid catalysis by Sn(2+). Similar α-regiochemistry was observed when the reaction of the 3-aminopyrrole salt with trifluoromethyl-β-diketones was carried out in the presence of base and tin(II) acetate.

  14. Ozone Promotes Chloropicrin Formation by Oxidizing Amines to Nitro Compounds.

    Science.gov (United States)

    McCurry, Daniel L; Quay, Amanda N; Mitch, William A

    2016-02-02

    Chloropicrin formation has been associated with ozonation followed by chlorination, but the reaction pathway and precursors have been poorly characterized. Experiments with methylamine demonstrated that ozonation converts methylamine to nitromethane at ∼100% yield. Subsequent chlorination converts nitromethane to chloropicrin at ∼50% yield under the conditions evaluated. Similarly high yields from other primary amines were limited to those with functional groups on the β-carbon (e.g., the carboxylic acid in glycine) that facilitate carbon-carbon bond cleavage to release nitromethyl anion. Secondary amines featuring these reactive primary amines as functional groups (e.g., secondary N-methylamines) formed chloropicrin at high yields, likely by facile dealkylation to release the primary nitro compound. Chloropicrin yields from tertiary amines were low. Natural water experiments, including derivatization to transform primary and secondary amines to less reactive carbamate functional groups, indicated that primary and secondary amines were the dominant chloropicrin precursors during ozonation/chlorination. Ozonation followed by chlorination of the primary amine side chain of lysine demonstrated low yields (∼0.2%) of chloropicrin, but high yields (∼17%) of dichloronitrolysine, a halonitroalkane structural analogue to chloropicrin. However, chloropicrin yields increased and dichloronitrolysine yields decreased in the absence of hydroxyl radical scavengers, suggesting that future research should characterize the potential occurrence of such halonitroalkane analogues relative to natural radical scavenger (e.g., carbonate) concentrations.

  15. An integrated scheme for the simultaneous determination of biogenic amines, precursor amino acids, and related metabolites by liquid chromatography with electrochemical detection.

    Science.gov (United States)

    Oka, K; Kojima, K; Togari, A; Nagatsu, T; Kiss, B

    1984-06-08

    A new method using high-performance liquid chromatography with electrochemical detection (HPLC-ED) for the simultaneous determination of monoamines, their precursor amino acids, and related major metabolites in small samples of brain tissue weighing from 0.5 to 50 mg is described. The method is based on the preliminary isolation of monoamines (dopamine, norepinephrine, epinephrine, and serotonin), their precursor amino acids (tyrosine, 3,4-dihydroxyphenylalanine, tryptophan and 5-hydroxytryptophan), and their major metabolites (3-methoxytyramine, normetanephrine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, vanillylmandelic acid, 3-methoxy-4-hydroxyphenylethyleneglycol, and 5-hydroxyindoleacetic acid) by chromatography on small columns of Amberlite CG-50 and Dowex 50W, and by ethyl acetate extraction. All the compounds in the four isolated fractions were measured by HPLC-ED on a reversed-phase column under four different conditions. The sensitivity was from 0.1 to 40 pmol, depending on the substances analysed. This newly established method was applied to the study of the effects of an aromatic L-amino acid decarboxylase inhibitor (NSD-1015) and a monoamine oxidase inhibitor (pargyline) on the levels of monoamines, their precursor amino acids and their major metabolites in brain regions of mice.

  16. The economics of amine usage

    International Nuclear Information System (INIS)

    Fountain, M.J.

    1994-01-01

    The EPRI computer programm, 'Aminemod', a PWR chemistry model, has been used to compare the technical advantages of the 'advanced' amines, ethanolamine, 1,2 diaminoethane and 5 aminopentanol over morpholine in generating an elevated pH in the moisture separator and the economics of using these amines has been assessed by using an MS Excel spreadsheet in conjunction with Aminemod. The advanced amines are capable of achieving 1 pH unit above neutrality, the EPRI target for prevention of erosion-corrison, at acceptable cost and, compared with 'conventional' amines, at considerably reduced ionic load on the condensate polisher. The exercise demonstrates that it is essential to evaluate the effect of an amine dosing regime on the total operating cost and that it is not possible to prejudge the economic outcome on the basis of an amine's purchase price. (orig.)

  17. Uranium diphosphonates templated by interlayer organic amines

    International Nuclear Information System (INIS)

    Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Albrecht-Schmitt, Thomas E.; Ewing, Rodney C.

    2013-01-01

    The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 °C results in the crystallization of a series of layered uranium diphosphonate compounds, [C 10 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Ubip2), [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} (UDAB), [C 2 H 10 N 2 ] 2 {(UO 2 ) 2 (H 2 O) 2 [CH 2 (PO 3 ) 2 ] 2 ·0.5H 2 O} (Uethyl), and [C 12 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Uphen). The crystal structures of the compounds are based on UO 7 units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also shown. The structure is constructed from UO 7 pentagonal bipyramids (yellow), oxygen=red, phosphorus=magenta, carbon=black, and nitrogen=blue. Highlights: ► Organic amines act both as charge-balancing and as structure-directing agents. ► Extensive hydrogen bonding interactions with solvent water molecules and amines

  18. Thermodynamic and structural of the water - dodecane - bis(ethyl-2-hexyl) phosphoric acid and its sodium salt; Etude thermodynamique et structurale du systeme: eau - dodecane - acide bis(ethyl-2 hexyl) phosphorique et de son sel de sodium

    Energy Technology Data Exchange (ETDEWEB)

    Lovera, Jacqueline

    1985-12-20

    This research thesis reports the study of the appearance and disappearance of the 'third phase' obtained during the salification of the bis(ethyl-2 hexyl) phosphoric acid (HDEHP) diluted in dodecane, by sodium aqueous solutions. After a large bibliographical study on the properties of the intervening compounds (extraction of metallic cation by the acid, parameters influencing the 'third phase' appearance, surfactant properties, direct and inverse micelles, formation of para-crystalline phases), the author presents chemical experimental methods: liquid-liquid extraction tests, tests by the synthetic way, preparation of reactants, dosing method, methods of chemical analysis). Then, she reports and discusses experimental results in terms of determination of phase diagrams at 25 C, of composition by weight of the third phase, of influence of the apolar diluent, and of influence of the electrolyte. Physical experimental methods are then presented (differential calorimetric analysis, NMR, small angle X-ray scattering, light scattering, polarised light microscopy, constrained phase microscopy, photography, infrared spectroscopy, conductometry, transmission electron micrography, volumetric mass measurements, surface and interface tension measurements, viscoelasticity measurements) and their results are discussed and interpreted [French] Nous etudions l'apparition et la disparition de la 'troisieme phase' obtenue lors de la salification de l'acide bis(ethyl-2 hexyl) phosphorique - HDEHP - dilue dans le dodecane, par des solutions aqueuses de soude. Nous obtenons cinq resultats experimentaux essentiels: a - dans le systeme etudie, la troisieme phase n'apparait qu'au dela de la salification. La phase qui apparait est une phase aqueuse de soude diluee, se separant de la phase organique en equilibre avec le dodecane presente a la salification exacte. b - la disparition de la troisieme phase s'effectue par recombinaison des deux phases organiques: la 'phase organique lourde

  19. Extraction separation studies of uranium(VI) by amine oxides

    International Nuclear Information System (INIS)

    Ejaz, M.

    1975-01-01

    The extraction of uranium(VI) by two amine oxides, 4-(5-nonyl)pyridine oxide and trioctylamine oxide has been studied. The extraction behavior of these two N-oxides is compared. The dependence of extraction on the type of amine oxide and acid, nature of organic diluent, and amine oxide concentration has been investigated. The influence of the concentration of the metal and salting-out agents is described. The possible mechanism of extraction is discussed in the light of the results of extraction isotherms, loading radiodata, and log-log plots of amine oxide concentration vs distribution ratio. The separation factors for a number of metal ions are reported, and the separation of uranium from some fission elements has also been achieved

  20. The ozonolysis of primary aliphatic amines in fine particles

    Science.gov (United States)

    Zahardis, J.; Geddes, S.; Petrucci, G. A.

    2008-02-01

    The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3- (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  1. The ozonolysis of primary aliphatic amines in fine particles

    Directory of Open Access Journals (Sweden)

    J. Zahardis

    2008-02-01

    Full Text Available The oxidative processing by ozone of the particulate amines octadecylamine (ODA and hexadecylamine (HDA is reported. Ozonolysis of these amines resulted in strong NO2 and NO3 ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3 (HNO3. For ozonized mixed particles containing ODA or HDA + oleic acid (OL, with pO3≥3×10–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines and stabilized Criegee intermediates (SCI or secondary ozonides (for amides from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10−3 atm for 17 s. This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3, formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  2. Azobisisobutyronitrile initiated aerobic oxidative transformation of amines: coupling of primary amines and cyanation of tertiary amines.

    Science.gov (United States)

    Liu, Lianghui; Wang, Zikuan; Fu, Xuefeng; Yan, Chun-Hua

    2012-11-16

    In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These "metal-free" aerobic oxidative coupling reactions may find applications in a wide range of "green" oxidation chemistry.

  3. Novel acid-base hybrid membrane based on amine-functionalized reduced graphene oxide and sulfonated polyimide for vanadium redox flow battery

    International Nuclear Information System (INIS)

    Cao, Li; Sun, Qingqing; Gao, Yahui; Liu, Luntao; Shi, Haifeng

    2015-01-01

    A series of novel acid-base hybrid membranes (SPI/PEI-rGO) based on sulfonated polyimide (SPI) with polyethyleneimine-functionalized reduced graphene oxide (PEI-rGO) are prepared by a solution-casting method for vanadium redox flow battery (VRB). FT-IR and XPS results prove the successful fabrication of PEI-rGO and SPI/PEI-rGO hybrid membranes, which show a dense and homogeneous structure observed by SEM. The physicochemical properties such as water uptake, swelling ratio, ion exchange capacity, proton conductivity and vanadium ion permeability are well controlled by the incorporated PEI-rGO fillers. The interfacial-formed acid-base pairs between PEI-rGO and SPI matrix effectively reduce the swelling ratio and vanadium ion permeability, increasing the stability performance of the hybrid membranes. SPI/PEI-rGO-2 hybrid membrane exhibits a higher coulombic efficiency (CE, 95%) and energy efficiency (EE, 75.6%) at 40 mA cm −2 , as compared with Nafion 117 membrane (CE, 91% and EE, 66.8%). The self-discharge time of the VRB with SPI/PEI-rGO-2 hybrid membrane (80 h) is longer than that of Nafion 117 membrane (26 h), demonstrating the excellent blocking ability for vanadium ion. After 100 charge-discharge cycles, SPI/PEI-rGO-2 membrane exhibits the good stability under strong oxidizing and acid condition, proving that SPI/PEI-rGO acid-base hybrid membranes could be used as the promising candidates for VRB applications

  4. Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

    Science.gov (United States)

    Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

    2012-01-01

    Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

  5. Control of biogenic amines in fermented sausages: role of starter cultures

    Directory of Open Access Journals (Sweden)

    Mariluz eLatorre-Moratalla

    2012-05-01

    Full Text Available Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

  6. Biogenic amines in dry fermented sausages: a review.

    Science.gov (United States)

    Suzzi, Giovanna; Gardini, Fausto

    2003-11-15

    Biogenic amines are compounds commonly present in living organisms in which they are responsible for many essential functions. They can be naturally present in many foods such as fruits and vegetables, meat, fish, chocolate and milk, but they can also be produced in high amounts by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern because their not equilibrate assumption in human organism can generate different degrees of diseases determined by their action on nervous, gastric and intestinal systems and blood pressure. High microbial counts, which characterise fermented foods, often unavoidably lead to considerable accumulation of biogenic amines, especially tyramine, 2-phenylethylamine, tryptamine, cadaverine, putrescine and histamine. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the quali-quantitative composition of microbial microflora, the chemico-physical variables, the hygienic procedure adopted during production, and the availability of precursors. Dry fermented sausages are worldwide diffused fermented meat products that can be a source of biogenic amines. Even in the absence of specific rules and regulations regarding the presence of these compounds in sausages and other fermented products, an increasing attention is given to biogenic amines, especially in relation to the higher number of consumers with enhanced sensitivity to biogenic amines determined by the inhibition of the action of amino oxidases, the enzymes involved in the detoxification of these substances. The aim of this paper is to give an overview on the presence of these compounds in dry fermented sausages and to discuss the most important factors influencing their accumulation. These include process and implicit factors as well as the role of starter and nonstarter microflora growing in the different steps of sausage production

  7. The economics of amine usage

    International Nuclear Information System (INIS)

    Fountain, M.J.

    1994-01-01

    Research carried out over the past decade in the USA (funded by EPRI) and by the CEGB/Nuclear Electric in the UK has identified several thermally stable, low-toxicity 'advanced' amines with good high-temperature basicity and low steam-water distribution ratio. As a direct result of this work several US PWR stations are now evaluating monoethanolamine (ETA) and Nuclear Electric's Wylfa Power Station (magnox) now doses 5 aminopentanol (5AP) instead of AMP, which had successfully combated erosion-corrosion for the past nine years. It has recently been stated that the use of 5AP ''...could save Nuclear Electric up to 1.5M pounds per year''. To provide US power station chemists with a tool for tailoring amine dosage to their own plant requirements EPRI has developed a computer model, Aminmod, which can, with user-defined circuit parameters and amine feed concentrations, calculate amine concentrations and pH(t) values at various points around the circuit. To complement this model a user-friendly spreadsheet program is being developed which will work in conjunction with Aminmod, via active links, to calculate the total operating cost associated with the selected amine dosing regime and compare alternative scenarios. This paper discusses the relationship between the technical and economic aspects of choosing an amine dosing regime and draws on combined Aminmod/spreadsheet results to illustrate how differences in amine properties can influence the optimum economic solution for a typical PWR. (author). 3 figs., 2 tabs., 5 refs

  8. Clustering of amines and hydrazines in atmospheric nucleation

    Science.gov (United States)

    Li, Siyang; Qu, Kun; Zhao, Hailiang; Ding, Lei; Du, Lin

    2016-06-01

    It has been proved that the presence of amines in the atmosphere can enhance aerosol formation. Hydrazine (HD) and its substituted derivatives, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), which are organic derivatives of amine and ammonia, are common trace atmospheric species that may contribute to the growth of nucleation clusters. The structures of the hydrazine and amine clusters containing one or two common nucleation molecules (ammonia, water, methanol and sulfuric acid) have been optimized using density functional theory (DFT) methods. The clusters growth mechanism has been explored from the thermochemistry by calculating the Gibbs free energies of adding an ammonia, water, methanol or sulfuric acid molecule step by step at room temperature, respectively. The results show that hydrazine and its derivatives could enhance heteromolecular homogeneous nucleation in the earth's atmosphere.

  9. Chemical and Molecular Descriptors for the Reactivity of Amines with CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Anita S.; Kitchin, John R.

    2012-10-24

    Amine-based solvents are likely to play an important role in CO{sub 2} capture applications in the future, and the identification of amines with superior performance will facilitate their use in CO{sub 2} capture. While some improvements in performance will be achieved through process modifications, modifying the CO{sub 2} capture performance of an amine also implies in part an ability to modify the reactions between the amine and CO{sub 2} through development of new functionalized amines. We present a computational study of trends in the reactions between CO{sub 2} and functionalized amines with a focus on identifying molecular descriptors that determine trends in reactivity. We examine the formation of bicarbonate and carbamate species on three classes of functionalized amines: alkylamines, alkanolamines, and fluorinated alkylamines including primary, secondary and tertiary amines in each class. These functional groups span electron-withdrawing to donating behavior, hydrogen-bonding, extent of functionalization, and proximity effects of the functional groups. Electron withdrawing groups tend to destabilize CO{sub 2} reaction products, whereas electron-donating groups tend to stabilize CO{sub 2} reaction products. Hydrogen bonding stabilizes CO{sub 2} reaction products. Electronic structure descriptors based on electronegativity were found to describe trends in the bicarbonate formation energy. A chemical correlation was observed between the carbamate formation energy and the carbamic acid formation energy. The local softness on the reacting N in the amine was found to partially explain trends carbamic acid formation energy.

  10. N-nitrosamine formation by monochloramine, free chlorine, and peracetic acid disinfection with presence of amine precursors in drinking water system.

    Science.gov (United States)

    West, Danielle M; Wu, Qihua; Donovan, Ariel; Shi, Honglan; Ma, Yinfa; Jiang, Hua; Wang, Jianmin

    2016-06-01

    In this study, the formation of eight N-nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine, N-nitrosomethylamine, N-nitrosodi-n-propylamine, N-nitrosodi-n-butylamine, N-Nitrosopiperidine, N-Nitrosopyrrolidine, N-Nitrosomorpholine, were systematically evaluated with respect to seven N-nitrosamine precursors (dimethylamine, trimethylamine, 3-(dimethylaminomethyl)indole, 4-dimethylaminoantipyrine, ethylmethylamine, diethylamine, dipropylamine) and three disinfectants (monochloramine, free chlorine, peracetic acid) under variable dosages, exposure times, and pH in a drinking water system. Without the presence of the seven selected N-nitrosamine precursors N-nitrosamine formation was not observed under any tested condition except very low levels of N-Nitrosopyrrolidine under some conditions. With selected N-nitrosamine precursors present N-nitrosamines formed at different levels under different conditions. The highest N-nitrosamine formation was NDMA with a maximum concentration of 1180 ng/L by monochloramine disinfection with precursors present; much lower levels of N-nitrosamines were formed by free chlorine disinfection; and no detectable level of N-nitrosamines were observed by peracetic acid disinfection except low level of N-Nitrosodi-n-propylamine under some conditions. NDMA formation was not affected by pH while four other N-nitrosamine formations were slightly affected by sample pH tested between 7 and 9, with formation decreasing with increasing pH. Monochloramine exposure time study displayed fast formation of N-nitrosamines, largely formed in four hours of exposure and maximized after seven days. This was a systematic study on the N-nitrosamine formation with the seven major N-nitrosamine precursors presence and absence under different conditions, including peracetic acid disinfection which has not been studied elsewhere. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain.

    Science.gov (United States)

    Burchett, Scott A; Hicks, T Philip

    2006-08-01

    ,N-dimethyltryptamine, and lysergic acid diethylamide, have revitalized the field of scientific studies investigating trace amine synaptic physiology, and its association with major human disorders of affect and cognition.

  12. Trace Amines and the Trace Amine-Associated Receptor 1: Pharmacology, Neurochemistry and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Yue ePei

    2016-04-01

    Full Text Available Biogenic amines are a collection of endogenous molecules that play pivotal roles as neurotransmitters and hormones. In addition to the classical biogenic amines resulting from decarboxylation of aromatic acids, including dopamine (DA, norepinephrine, epinephrine, serotonin (5-HT and histamine, other biogenic amines, present at much lower concentrations in the central nervous system (CNS, and hence referred to as trace amines (TAs, are now recognized to play significant neurophysiological and behavioural functions. At the turn of the century, the discovery of the trace amine-associated receptor 1 (TAAR1, a phylogenetically conserved G protein-coupled receptor that is responsive to both TAs, such as β-phenylethylamine, octopamine and tyramine, and structurally-related amphetamines, unveiled mechanisms of action for TAs other than interference with aminergic pathways, laying the foundations for deciphering the functional significance of TAs and its mammalian CNS receptor, TAAR1. Although its molecular interactions and downstream targets have not been fully elucidated, TAAR1 activation triggers accumulation of intracellular cAMP, modulates PKA and PKC signalling and interferes with the β-arrestin2-dependent pathway via G protein-independent mechanisms. TAAR1 is uniquely positioned to exert direct control over DA and 5-HT neuronal firing and release, which has profound implications for understanding the pathophysiology of, and therefore designing more efficacious therapeutic interventions for, a range of neuropsychiatric disorders that involve aminergic dysregulation, including Parkinson’s disease, schizophrenia, mood disorders and addiction. Indeed, the recent development of novel pharmacological tools targeting TAAR1 has uncovered the remarkable potential of TAAR1-based medications as new generation pharmacotherapies in neuropsychiatry. This review summarizes recent developments in the study of TAs and TAAR1, their intricate neurochemistry and

  13. Relation between separation factor of carbon isotope and chemical reaction of CO2 with amine in nonaqueous solvent

    International Nuclear Information System (INIS)

    Takeshita, Kenji; Kitamoto, Asashi

    1989-01-01

    The separation factor for carbon isotope exchange reaction between CO 2 and amine in nonaqueous solvent was related to absorption reaction of CO 2 in a solution. The test solutions were mixtures of primary amine (such as butylamine and tert-butylamine) or secondary amine (such as diethylamine, dipropylamine and dibutylamine) diluted with nonpolar solvent (octane or triethyalmine) or polar solvent (methanol), respectively. The isotope exchange reaction consists of three steps related to chemical reaction of CO 2 in amine and nonaqueous solvent mixture, namely the reaction between CO 2 and carbamic acid, that between CO 2 and amine carbamate, and that between CO 2 and carbamic ion. Above all, the isotope separation factor between CO 2 and carbamic acid had the highest value. The overall separation factor can be higher in amine-nonaqueous solvent mixture where the concentration of carbamic acid becomes higher. (author)

  14. Synthesis of new chiral amines with a cyclic 1,2-diacetal skeleton derived from (2R, 3R)-(+)-tartaric acid.

    Science.gov (United States)

    Barros, M Teresa; Phillips, Ana Maria Faísca

    2006-03-17

    The syntheses of new chiral cyclic 1,2-diacetals from (2R, 3R)-( )-tartaric acid are described. C(2)-symmetrical diamines were prepared via direct amidation of the tartrate or from the corresponding bismesylate via reaction with sodium azide. For C1-symmetrical compounds, the Appel reaction was used to form the key intermediate, a monochlorocarbinol, from the diol. Some of the new chiral compounds, produced in good to high yields, may be potentially useful as asymmetric organocatalysts or as nitrogen and sulfur chelating ligands for asymmetric metal catalyzed reactions. Thus, a bis-N-methyl-methanamine derivative, used in substoichiometric amounts, was found to catalyze the enantioselective addition of cyclohexanone to (E)-beta-nitrostyrene with high diastereoselectivity (syn / anti = 92:8), albeit giving moderate optical purity (syn: 30 %).

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

    Science.gov (United States)

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

    2010-05-17

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

  16. METALCOMPLEXES OF TELLURIUM-CONTAINING AMINES AND AZOMETINES

    Directory of Open Access Journals (Sweden)

    G. M. Abakarov

    2014-01-01

    Full Text Available In this article methods of synthesis and reactionary ability of metalcomplexes of tellurium-containing amines, azometines, of a problem of competitive coordination with use of the principle of "soft" and "rigid" acids and the bases (R. Pearson.

  17. Ultrasound-assisted oxidative desulfurization process of liquid fuel by phosphotungstic acid encapsulated in a interpenetrating amine-functionalized Zn(II)-based MOF as catalyst.

    Science.gov (United States)

    Afzalinia, Ahmad; Mirzaie, Abbas; Nikseresht, Ahmad; Musabeygi, Tahereh

    2017-01-01

    In this work, ultrasound-assisted oxidative desulfurization (UAOD) of liquid fuels performed with a novel heterogeneous highly dispersed Keggin-type phosphotungstic acid (H 3 PW 12 O 40 , PTA) catalyst that encapsulated into an amino-functionalized MOF (TMU-17-NH 2 ). The prepared composite exhibits high catalytic activity and reusability in oxidative desulfurization of model fuel. Ultrasound-assisted oxidative desulfurization (UAOD) is a new way to performed oxidation reaction of sulfur-contain compounds rapidly, economically, environment-friendly and safely, under mild conditions. Ultrasound waves can be apply as an efficient tool to decrease the reaction time and improves oxidative desulfurization system performance. PTA@TMU-17-NH 2 could be completely performed desulfurization of the model oil by 20mg of catalyst, O/S molar ratio of 1:1 in presence of MeCN as extraction solvent. The obtained results indicated that the conversions of DBT to DBTO 2 achieve 98% after 15min in ambient temperature. In this work, we prepared TMU-17-NH 2 and PTA/TMU-17-NH 2 composite by ultrasound irradiation for first time and employed in UAOD process. Prepared catalyst exhibit an excellent reusability without PTA leaching and loss of activity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Fonctionnalité, résilience, maintenance, acides gras insaturés Un exemple : l’acide linoléique et les récepteurs du LDL-cholestérol

    Directory of Open Access Journals (Sweden)

    Mendy François

    2001-07-01

    Full Text Available Fonctionnalité, résilience, maintenance, et acides gras poly-insaturés. Il deviendra impossible dans le futur de poser le problème des apports nutritionnels conseillés sans se poser la question : Conseillés dans quel but ? Comptable, humanitaire, épanouissement individuel ? Obtenir une croissance, une reproduction, un gain de masse musculaire dans le plus court temps sont des objectifs de nutritionnistes zoo-techniciens. Dans ce système, l’objectif final est la mort programmée dans un abattoir dans le délai le plus court et le plus rentable possible. En nutrition humaine, l’objectif est d’obtenir la meilleure adaptabilité possible dans n’importe quelle situation et le plus longtemps possible. L’objectif n’est plus comme à la fin du xviiie et xixe siècle, d’obtenir une main-d’oeuvre pouvant se développer et se reproduire le plus rapidement possible, assurer un travail physique efficace au moindre coût. Peut-être est-il la transmission des connaissances anciennes, l’acquisition et la transmission de connaissances nouvelles, durant le plus lontemps possible. Pour l’homme, la définition des apports nutritionnels conseillés devrait être la définition des marges de sécurités entre les apports minimaux acceptables et les apports maximaux tolérables. Ces marges de sécurité devraient permettre d’obtenir une fonctionnalité réelle, soit la meilleure conformation récepteurs-enzymes, malgré des status génétiques variés (mutations, polymorphisme, etc., un environnement aléatoire, d’obtenir la résislience, l’adaptabilité individuelle, maximale, durant le plus longtemps possible (maintenance. Il n’existe pas d’autres possibilités de prévention des maladies conformationnelles nouvellement décrites. À titre d’exemple, les conditions d’obtention du niveau de régulation optimale du récepteur LDL, la dégradation sécrétoire de l’ApoB par le récepteur LDL sur le chemin de la s

  19. Production of Primary Amines by Reductive Amination of Biomass-Derived Aldehydes/Ketones.

    Science.gov (United States)

    Liang, Guanfeng; Wang, Aiqin; Li, Lin; Xu, Gang; Yan, Ning; Zhang, Tao

    2017-03-06

    Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO 2 , which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO 2 -containing multivalence Ru association species worked as a bifunctional catalyst, with RuO 2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Enhancing amine terminals in an amine-deprived collagen matrix.

    LENUS (Irish Health Repository)

    Tiong, William H C

    2008-10-21

    Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.

  1. Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

    Science.gov (United States)

    Wendlandt, Alison E; Stahl, Shannon S

    2012-06-01

    Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

  2. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    International Nuclear Information System (INIS)

    Hosseini Koupaie, E.; Alavi Moghaddam, M.R.; Hashemi, S.H.

    2011-01-01

    Highlights: → Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. → More than 65% of the dye total metabolites was completely mineralized. → Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. → Inhibition of biofilm growth was increased with increasing the initial dye concentration. → Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  3. Genetic cytological and biochemical study of a tomato chlorophyll mutant of the xanthic type, obtained by irradiation of the seeds; Etude genetique, cytologique et biochimique d'un mutant chlorophyllien de tomate du type xantha, obtenu par irradiation de graines

    Energy Technology Data Exchange (ETDEWEB)

    Lefort, M; Duranton, J; Galmiche, J M; Roux, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Irradiation of Lycopersicum aesculantum seeds with increasing doses of X-rays and thermal neutrons leads to the appearance of chlorophyll mutations in the descendants of the irradiated seeds. A genetic study of one of these mutants of the xanthic type showed that it was a recessive mutant with typical mono-genetic separation, while the cytological study demonstrated that the differentiation of the plast stopped at the stage of elementary lamella. Finally it is shown that in the light, the mutation brings about a very large deviation of the carbon metabolism towards the synthesis of amino acids and proteins, at the expense of that of glucosides. (author) [French] L'irradiation de graines de Lycopersicum Aesculantum avec des doses croissantes de rayons X et de neutrons thermiques entraine l'apparition de mutations chlorophylliennes dans la descendance des graines irradiees. L'etude genetique d'un de ces mutants du type xantha a montre qu'il s'agissait d'un mutant recessif a disjonction monogenique typique, tandis que l'etude cytologique a revele que la differentiation du plaste s'arretait au stade de lamelles elementaires. Il est apparu enfin qu'a la lumiere la mutation entrainait une deviation tres importante du metabolisme du carbone vers la synthese des acides amines et des proteines, au detriment de celle des glucides. (auteur)

  4. Color test for selective detection of secondary amines on resin and in solution.

    Science.gov (United States)

    Boas, Ulrik; Mirsharghi, Sahar

    2014-11-21

    Resins for solid-phase synthesis give orange to red-brown resin beads selectively when secondary amines are present on the resin when treated with a solution of acetaldehyde and an Fmoc-amino acid in NMP. The method shows good specificity and gives colorless beads when exposed to a variety of other functional groups. Furthermore, the acetaldehyde/Fmoc amino acid method can be used as a selective colorimetric test for secondary amines in solution.

  5. Uranium diphosphonates templated by interlayer organic amines

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, 52428 Juelich (Germany); Institut fuer Kristallographie, RWTH Aachen University, D-52066 Aachen (Germany); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556 (United States); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States)

    2013-02-15

    The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 Degree-Sign C results in the crystallization of a series of layered uranium diphosphonate compounds, [C{sub 10}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Ubip2), [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} (UDAB), [C{sub 2}H{sub 10}N{sub 2}]{sub 2}{l_brace}(UO{sub 2}){sub 2}(H{sub 2}O){sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sub 2}{center_dot}0.5H{sub 2}O{r_brace} (Uethyl), and [C{sub 12}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Uphen). The crystal structures of the compounds are based on UO{sub 7} units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also

  6. Comparison of Predicted pKa Values for Some Amino-Acids, Dipeptides and Tripeptides, Using COSMO-RS, ChemAxon and ACD/Labs Methods Comparaison des valeurs de pKa de quelques acides aminés, dipeptides et tripeptides, prédites en utilisant les méthodes COSMO-RS, ChemAxon et ACD/Labs

    Directory of Open Access Journals (Sweden)

    Toure O.

    2013-05-01

    as peptides. The final goal of this study is to use the pKa values in a predictive thermodynamics model for products of interest in food industry. For this purpose, the effects of several factors (like conformations set treatment in COSMO-RS calculations, ionic strength effect that can affect the comparison between observed and predicted pKa data are discussed. Les valeurs de constantes d’acidité (pKa jouent un rôle très important, en particulier dans l’industrie alimentaire. Les propriétés chimiques des molécules dépendent significativement de leurs états d’ionisation. La plupart des molécules sont capables de gagner et/ou perdre un proton dans les solutions aqueuses. Ce transfert de proton apparaît la plupart du temps entre l’eau et un atome ionisable de la molécule organique. La réponse de la molécule à la protonation ou à la déprotonation dépend significativement du site concerné par le transfert de proton. La distribution partielle des charges dans la molécule varie également en fonction des sites actifs pour la protonation du couple acide; base. Par conséquent on peut l’utiliser pour déterminer le pKa d’une molécule. Dans un premier temps, nous avons utilisé la méthode COSMO-RS, une combinaison du modèle de solvatation diélectrique (COSMO et d’un traitement de thermodynamique statistique pour des solvants plus réels (RS, pour prédire les constantes de dissociation de 50 molécules environ (des acides aminés, des dipeptides et des tripeptides. Les résultats de pKa obtenus ont été comparés aux valeurs expérimentales, ainsi qu’aux valeurs de pKa prédites par deux autres méthodes. Nous avons utilisé respectivement la méthode ChemAxon, utilisant un programme basé sur le calcul des charges partielles des atomes d’une molécule, et la méthode ACD/Labs qui permet de déterminer des valeurs de pKa pour chaque centre de dissociation en considérant que le reste de la molécule est neutre, en utilisant une base de

  7. Amine Swingbed Payload Project Management

    Science.gov (United States)

    Walsch, Mary; Curley, Su

    2013-01-01

    The International Space Station (ISS) has been designed as a laboratory for demonstrating technologies in a microgravity environment, benefitting exploration programs by reducing the overall risk of implementing such technologies in new spacecraft. At the beginning of fiscal year 2010, the ISS program manager requested that the amine-based, pressure-swing carbon dioxide and humidity absorption technology (designed by Hamilton Sundstrand, baselined for the Orion Multi-Purpose Crew Vehicle, and tested at the Johnson Space Center in relevant environments, including with humans, since 2005) be developed into a payload for ISS Utilization. In addition to evaluating the amine technology in a flight environment before the first launch of the Orion vehicle, the ISS program wanted to determine the capability of the amine technology to remove carbon dioxide from the ISS cabin environment at the metabolic rate of the full 6 ]person crew. Because the amine technology vents the absorbed carbon dioxide and water vapor to space vacuum (open loop), additional hardware needed to be developed to minimize the amount of air and water resources lost overboard. Additionally, the payload system would be launched on two separate Space Shuttle flights, with the heart of the payload-the swingbed unit itself-launching a full year before the remainder of the payload. This paper discusses the project management and challenges of developing the amine swingbed payload in order to accomplish the technology objectives of both the open -loop Orion application as well as the closed-loop ISS application.

  8. Development and validation of an LC?MS/MS method for the determination of biogenic amines in wines and beers

    OpenAIRE

    Nalazek-Rudnicka, Katarzyna; Wasik, Andrzej

    2017-01-01

    Abstract Biogenic amines are group of organic, basic, nitrogenous compounds that naturally occur in plant, microorganism, and animal organisms. Biogenic amines are mainly produced through decarboxylation of amino acids. They are formed during manufacturing of some kind of food and beverages such as cheese, wine, or beer. Histamine, cadaverine, agmatine, tyramine, putrescine, and ?-phenylethylamine are the most common biogenic amines found in wines and beers. This group of compounds can be tox...

  9. Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

    International Nuclear Information System (INIS)

    Moyer, B.A.; McDowell, W.J.

    1981-01-01

    The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used

  10. Platinum-Catalyzed, Terminal-Selective C(sp(3))-H Oxidation of Aliphatic Amines.

    Science.gov (United States)

    Lee, Melissa; Sanford, Melanie S

    2015-10-14

    This Communication describes the terminal-selective, Pt-catalyzed C(sp(3))-H oxidation of aliphatic amines without the requirement for directing groups. CuCl2 is employed as a stoichiometric oxidant, and the reactions proceed in high yield at Pt loadings as low as 1 mol%. These transformations are conducted in the presence of sulfuric acid, which reacts with the amine substrates in situ to form ammonium salts. We propose that protonation of the amine serves at least three important roles: (i) it renders the substrates soluble in the aqueous reaction medium; (ii) it limits binding of the amine nitrogen to Pt or Cu; and (iii) it electronically deactivates the C-H bonds proximal to the nitrogen center. We demonstrate that this strategy is effective for the terminal-selective C(sp(3))-H oxidation of a variety of primary, secondary, and tertiary amines.

  11. Extraction of beryllium sulfate by a long chain amine

    International Nuclear Information System (INIS)

    Etaix, E.S.

    1968-01-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [fr

  12. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  13. Sodium Perborate Oxidation of an Aromatic Amine

    Science.gov (United States)

    Juestis, Laurence

    1977-01-01

    Describes an experiment involving the oxidation of aromatic primary amines to the corresponding azo compound; suggests procedures for studying factors that influence the yield of such a reaction, including the choice of solvent and the oxidant-amine ratio. (MLH)

  14. Electrochemical degradation of aromatic amines on BDD electrodes

    International Nuclear Information System (INIS)

    Pacheco, M.J.; Santos, V.; Ciriaco, L.; Lopes, A.

    2011-01-01

    The electrochemical oxidation of four aromatic amines, with different substituent groups, 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid (A1), 5-amino-2-methoxybenzenesulfonic acid (A2), 2,4-dihydroxyaniline hydrochloride (A3) and benzene-1,4-diamine (A4), was performed using as anode a boron-doped diamond electrode, commercially available at Adamant Technologies. Tests were run at room temperature with model solutions of the different amines, with concentrations of 200 ppm, using as electrolyte 0.035 M Na 2 SO 4 aqueous solutions, in a batch cell with recirculation, at different current densities (200 and 300 A m -2 ). The following analyses were performed with the samples collected during the assays: UV-Vis spectrophotometry, chemical oxygen demand (COD), total organic carbon (TOC), total Kjeldahl nitrogen, ammonia nitrogen, nitrates and HPLC. Results have shown a good electrodegradation of all the amines tested, with COD removals, after 6 h assays, higher than 90% and TOC removals between 60 and 80%. Combustion efficiency (η C ), which measures the tendency to convert organic carbon to CO 2 , was also determined for all the amines, being η CA1 CA2 CA3 CA4 = 0.99.

  15. Interaction of biogenic amines with ethanol.

    Science.gov (United States)

    Smith, A A

    1975-01-01

    Ethanol through its primary catabolite, acetaldehyde, competitively inhibits oxidation of aldehyde dehydrogenase substrates. As a consequence biogenic amines form increased quantities of alcohols rather than the corresponding acids. During this biotransformation, condensation reactions between deaminated and intact amines may occur which can yield tetrahydropapaverolines. These compounds are closely related to precursors of opioids which is cause to link ethanol abuse to morphine addiction. There is, however, no pharmacological or clinical evidence suggesting similarities between ethanol dependence or opiod addiction. Acetaldehyde plays an additional role in alkaloidal formation in vitro. Biogenic amines may react with acetaldehyde to form isoquinoline or carboline compounds. Some of these substances have significant pharmacological activity. Furthermore, they may enter neural stores and displace the natural neurotransmitter. Thus, they can act as false neurotransmitters. Some investigators believe that chronic ethanol ingestion leads to significant formation of such aberrant compounds which may then upset autonomic nervous system balance. This disturbance may explain the abnormal sympathetic activity seen in withdrawal. While these ideas about the etiology of alcohol abuse have a definite appeal, they are naturally based on in vitro preliminary work. Much study of the quantitative pharmacology of these compounds in animals is required before judgement can be made as to the merits of the proposed hypotheses. In the meantime, pharmacological studies on the ability of ethanol to depress respiration in the mouse has revealed that unlike opioids or barbituates, respiratory depression induced by ethanol requires the presence in brain of serotonin. This neurotransmitter also mediates the respiratory effects of several other alcohols but curiously, not chloral hydrate, yet this compound is purported to alter biogenic amine metabolism much like ethanol. Thus, the response

  16. Comparative study of kinetic reaction of 4,4′-Methylenebis (2-m ethel cyclo hexyl amine) with dimeric fatty acid c36 by use of a catalyst of phosphoric acid and dioxide manganese

    International Nuclear Information System (INIS)

    Al-Mohanna, N.; Al-Mohammad, H.

    2015-01-01

    Kinetic study was carried out on the reaction between 4,4′-Methylenebis (2-methylcyclohexylamine and dimeric fatty acid C 3 6 in molten state by use a catalyst of phosphoric acid and dioxide manganese the reaction was performed at 150 o C, and followed by determining the acid value of the product the polyamidation reaction was found to be of overall a second order until equilibrium state moreover the reaction was faster in the presence of the dioxide manganese polyamidation reaction was automatic where the value of free energy was negative the kinetics of thermal degradation was studied by use of thermogravimetric analysis (TGA) and was found to be of overall a second order and was followed by determining the thermodynamic constants of the thermal degradation reaction melting points and transitional glass in the presence of the catalyst were determined by use of differential calorimetry scanning (DSC) and was found to be close the degree of polymerization number average molecular weight and weight average molecular weight have been calculated during different times we noticed that the relationship between degree of polymerization and number average molecular weight, weight average molecular weight with time is linear until equilibrium state the prepared polyamide involve crystallization and amorphous area this was shown by XRD spectra. (author)

  17. Electrochemical characterization of aminated acrylic conducting polymer

    International Nuclear Information System (INIS)

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-01-01

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study

  18. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  19. Characterization of molybdenum interfacial crud in a uranium mill that employs tertiary-amine solvent extraction

    International Nuclear Information System (INIS)

    Moyer, B.; McDowell, W.J.

    1983-01-01

    In the present work, samples of a molybdenum-caused green gummy interfacial crud from an operating western US uranium mill have been physically and chemically examined. Formaton of cruds of this description has been a long-standing problem in the use of tertiary amine solvent extraction for the recovery of uranium from low-grade ores (Amex Process). The crud is essentially an organic-continuous dispersion containing about 10 wt % aqueous droplets and about 37 wt % greenish-yellow crystalline solids suspended in kerosene-amine process solvent. The greenish-yellow crystals were found to be a previously unknown double salt of tertiary amine molybdophosphate with three tertiary amine chlorides having the empirical formula (R 3 NH) 3 [PMo 12 O 40 ].3(R 3 NH)Cl. To confirm the identification of the compound, a pure trioctylamine (TOA) analog was synthesized. In laboratory extraction experiments, it was demonstrated that organic-soluble amine molydophosphate forms slowly upon contact of TOA solvent with dilute sulfuric acid solutions containing low concentrations of molybdate and phosphate. If the organic solutions of amine molybdophosphate were then contacted with aqueous NaCl solutions, a greenish-yellow precipitate of (TOAH) 3 [PMo 12 O 40 ].3(TOAH)Cl formed at the interface. The proposed mechanism for the formation of the crud under process conditions involves build up of molybdenum in the solvent, followed by reaction with extracted phosphate to give dissolved amine molybdophosphate. The amine molybdophosphate then co-crystallizes with amine chloride, formed during the stripping cycle, to give the insoluble double salt, which precipitates as a layer of small particles at the interface. The proposed solution to the problem is the use of branched-chain, instead of straight-chain, tertiary amine extractants under the expectation that branching would increase the solubility of the double salt. 2 figures, 5 tables

  20. Fiche technique du spermogramme et du spermocytogramme ...

    African Journals Online (AJOL)

    En Afrique la stérilité du couple constitue un drame social. Selon l'OMS, environ 8 à 12 % des couples africains sont touchés par une infertilité. La responsabilité masculine dans la stérilité est comprise entre 30 à 40%. Les causes de l'infertilité masculine peuvent être l'impuissance et/ ou l'altération du sperme. L'étude de ...

  1. Biogenic Amines in Insect Antennae

    Directory of Open Access Journals (Sweden)

    Marianna I. Zhukovskaya

    2017-06-01

    Full Text Available Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA and its metabolic precursor tyramine (TA affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA modulates gustatory neurons. Serotonin can serve as a neurotransmitter in some afferent mechanosensory neurons and both as a neurotransmitter and neurohormone in efferent fibers targeted at the antennal vessel and mechanosensory organs. As a neurohormone, serotonin affects the generation of the transepithelial potential by sensillar accessory cells. Other possible targets of biogenic amines in insect antennae are hygro- and thermosensory neurons and epithelial cells. We suggest that the insect antenna is partially autonomous in the sense that biologically active substances entering its hemolymph may exert their effects and be cleared from this compartment without affecting other body parts.

  2. Bilan du 7e congrès organisé par l’International Society For the Study of Fatty Acids and Lipids (ISSFAL, à Cairns, Australie, du 23 au 28 juillet 2006

    Directory of Open Access Journals (Sweden)

    Guesnet Philippe

    2007-01-01

    Full Text Available The 7th congress was organized by the International Society For the Study of Fatty Acids and Lipids (ISSFAL in Cairns (Australia from 23 to 28 July 2006. It joined more than 400 delegates from 35 countries. The meeting included a plenary program, with 25 conferences and selected short communications, and 32 concurrent sessions in which around 300 free communications were presented (oral + posters. The primary themes explored several areas of research on lipids, fatty acids, metabolism and cerebral functions (3 sessions and 4 plenary conferences with respect to maternal and infant health (3 sessions, ageing (1 session and Alzheimer disease (1 session, omega-3 fatty acids and mental health (1 session, PUFA metabolism (3 sessions, the impact of dietary omega-3 and trans fatty acids on several pathologies such as obesity (1 session, cardiovascular disease and the metabolic syndrome (4 sessions and 3 plenary conferences, diabetes (1 session, cancer (1 session and osteoporosis (1 session. Lastly, several concurrent sessions focused on methodological aspects for implementing new dietary sources of fatty acids (4 sessions.

  3. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    politique de bas prix exercée par la Russie et le Qatar vient confirmer ce constat ; s'ajoute à cela l'entrée éventuelle du gaz non conven- tionnel, dont son prix actuel de 3/4 $US, offre aux USA l'opportunité d'être exportateur de ..... les compagnies à produire en matière du gaz naturel, tels le prix du gaz naturel, le prix des ...

  4. Bulletin du CRDI #124

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les femmes jouent un rôle important dans les exploitations minières artisanales et à petite échelle en Afrique subsaharienne. De concert ... Couverture du livre: Une vie saine pour les femmes et les enfants vulnérables · Couverture du livre: Entre el activismo y la intervención · Couverture du livre: Revitalizing Health for All.

  5. Bulletin du CRDI #125

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'IOSRS remporte le prix de la diplomatie scientifique · GrowInclusive : la plateforme tant attendue est en construction · Toutes les nouvelles. Activités à venir. Semaine du développement international 2018. Le CRDI célébrera la Semaine du développement international du 4 au 10 février 2018. Suivez-nous sur Twitter et ...

  6. Réponses comportementales du brochet (Esox lucius L. à un extrait épidermique de carassin doré (Carassius auratus L. en olfactomètre

    Directory of Open Access Journals (Sweden)

    SAGLIO Ph.

    1993-04-01

    Full Text Available Les effets de solutions brutes (EE et d'une fraction d'acides aminés libres reconstituée (FAA, issues d'un extrait épidermique de Carassin doré (Carassius auratus L., ont été analysés sur l'attraction et le comportement exploratoire du Brochet (Esox lucius L. en olfactomètre. Des effets significatifs ont été observés en réponse aux différentes solutions et doses testées (EE = 0,005 ; 0,05 ; 0,5 équivalent-carassin/l ; FAA = 0,5 équivalent-carassin/l. L'effet stimulant des solutions épidermiques brutes sur l'exploration varie en raison inverse de la concentration testée. L'activité de ces solutions sur l'attraction augmente avec la concentration. L'effet stimulant de la fraction d'acides aminés libres reconstituée sur l'exploration et sur l'attraction est apparu inférieur à celui observé en réponse à la solution brute. Ces résultats sont discutés à la lueur de données sur le rôle des sécrétions de la peau et des acides aminés dans la communication chimique chez les poissons.

  7. Manganese-catalysed benzylic C(sp3)-H amination for late-stage functionalization.

    Science.gov (United States)

    Clark, Joseph R; Feng, Kaibo; Sookezian, Anasheh; White, M Christina

    2018-06-01

    Reactions that directly install nitrogen into C-H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Although selective intramolecular C-H amination reactions are known, achieving high levels of reactivity while maintaining excellent site selectivity and functional-group tolerance remains a challenge for intermolecular C-H amination. Here, we report a manganese perchlorophthalocyanine catalyst [MnIII(ClPc)] for intermolecular benzylic C-H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site selectivity. In the presence of a Brønsted or Lewis acid, the [MnIII(ClPc)]-catalysed C-H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies suggest that C-H amination likely proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C-H cleavage is the rate-determining step of the reaction. Collectively, these mechanistic features contrast with previous base-metal-catalysed C-H aminations and provide new opportunities for tunable selectivities.

  8. Regularities of synthesis and mechanism of polycondensation of aromatic amines

    International Nuclear Information System (INIS)

    Matnishyan, Hagob

    2002-01-01

    Full text.Aniline polymers and its derivatives are widely used in modern electronics, electrical engineering and manufacturing of various appliances. They are used for production of electrical power sources, probes and sensors, composite materials absorbing high frequency radiations, anticorrosion coatings, nonlinear optical devices-such as lasers, cathode ray tubes, photodiodes etc. Such a wide usage of aromatic amine polymers brings up new demands to their structure and properties, which is dependent on conditions of synthesis and forming of the hard phase. The presented article describes regularities and mechanisms of oxidative polycondensation of aromatic amines. Several types of polymers have been synthesized by chemical and electrochemical oxidation of aniline and its chlor-, brom-, iodo-, nitro-, p-substituted derivatives; diphenylamine, benzidine and phenylenediamines in nonwater media. On the basis of kinetic and electrochemical studies and literature analysis we suggested a mechanism of polycondensation of aromatic amines. According to it, oxidation of amines starts with the electron transfer with cation-radical formation on the first stage, which stabilizes in acid environments due to complex formation with initial amine. Dimer formation and further growth of chain takes place upon another electron transfer from formed complex, which results in forming of macromolecules. We also suggested a scheme for obtaining of structures defect in media assisting in deprotonizing of cation radicals and formation of arylamine radical centers. Those processes lead to formation of azo- and diphenyl fragments in the main chain of the polymer and predetermine the possibility of chain disruption. We also considered reactions leading to formation of branched polymers and cyclic structures, such as phenazine in particular. The peculiarity of electrochemical process lies in regulation of concentration of active centres on the positive electrode surface

  9. Iridium-Catalyzed Condensation of Primary Amines To Form Secondary Amines

    DEFF Research Database (Denmark)

    Lorentz-Petersen, Linda Luise Reeh; Jensen, Paw; Madsen, Robert

    2009-01-01

    Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields.......Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields....

  10. "Cirque du Freak."

    Science.gov (United States)

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  11. Novel bioreducible poly(amido amine)s for highly efficient gene delivery

    NARCIS (Netherlands)

    Lin, C.; Zhong, Zhiyuan; Lok, Martin C.; Jiang, Xulin; Hennink, Wim E.; Feijen, Jan; Engbersen, Johannes F.J.

    2007-01-01

    A series of novel bioreducible poly(amido amine)s containing multiple disulfide linkages (SS-PAAs) were synthesized and evaluated as nonviral gene vectors. These linear SS-PAAs could be easily obtained by Michael-type polyaddition of various primary amines to the disulfide-containing cystamine

  12. Biogenic amines degradation by malolactic bacteria: towards a potential application in wine

    Directory of Open Access Journals (Sweden)

    Vittorio eCapozzi

    2012-04-01

    Full Text Available Biogenic amines in wine represent a toxicological risk for the health of the consumer, with several trade implications. In this study 26 strains of Lactobacillus plantarum were analysed for their ability to degrade biogenic amines commonly found during wine fermentation. Two strains of L. plantarum were selected in reason of their ability to degrade putrescine and tyramine. The degradation was assessed in vitro, both in presence of the biogenic amines and in presence of the specific chemical precursor and of producer bacteria. The two L. plantarum biotypes were found capable to work synergically. In addition, the survival in wine-like medium and the aptitude to degrade malic acid after alcoholic fermentation of the selected L. plantarum strains was analysed. Our results suggest the potential application of wine L. plantarum strains to design malolactic starter cultures able to degrade biogenic amines in wine.

  13. Purification and characterization of the amine dehydrogenase from a facultative methylotroph.

    Science.gov (United States)

    Coleman, J P; Perry, J J

    1984-01-01

    Strain RA-6 is a pink-pigmented organism which can grow on a variety of substrates including methylamine. It can utilize methylamine as sole source of carbon via an isocitrate lyase negative serine pathway. Methylamine grown cells contain an inducible primary amine dehydrogenase [primary amine: (acceptor) oxidoreductase (deaminating)] which is not present in succinate grown cells. The amine dehydrogenase was purified to over 90% homogeneity. It is an acidic protein (isoelectric point of 5.37) with a molecular weight of 118,000 containing subunits with approximate molecular weights of 16,500 and 46,000. It is active on an array of primary terminal amines and is strongly inhibited by carbonyl reagents. Cytochrome c or artificial electron acceptors are required for activity; neither NAD nor NADP can serve as primary electron acceptor.

  14. Interaction of aromatic amines with iron oxides: implications for prebiotic chemistry.

    Science.gov (United States)

    Shanker, Uma; Singh, Gurinder; Kamaluddin

    2013-06-01

    The interaction of aromatic amines (aniline, p-chloroaniline, p-toludine and p-anisidine) with iron oxides (goethite, akaganeite and hematite) has been studied. Maximum uptake of amines was observed around pH 7. The adsorption data obtained at neutral pH were found to follow Langmuir adsorption. Anisidine was found to be a better adsorbate probably due to its higher basicity. In alkaline medium (pH > 8), amines reacted on goethite and akaganeite to give colored products. Analysis of the products by GC-MS showed benzoquinone and azobenzene as the reaction products of aniline while p-anisidine afforded a dimer. IR analysis of the amine-iron oxide hydroxide adduct suggests that the surface acidity of iron oxide hydroxides is responsible for the interaction. The present study suggests that iron oxide hydroxides might have played a role in the stabilization of organic molecules through their surface activity and in prebiotic condensation reactions.

  15. Berkelium (4) and cerium (4) extraction with tertiary amines

    International Nuclear Information System (INIS)

    Milyukova, M.S.; Malikov, D.A.; Myasoedov, B.V.

    1978-01-01

    Oxidation of indicator quantities of berkelium and cerium by a mixture of silver nitrate and ammonium persulfate in the solutions of nitric and sulfuric acid has been examined. The stability of the elements in a tetravalent state and their extraction by the solutions of ternary amines have been investigated. It has been established that berkelium and cerium oxidation under these conditions occurs under the effect of ions of divalent silver which is formed owing to oxidation of monovalent silver by peroxide sulfate ions. The following supposition has been put forward: a difference in the behaviour of tetravalent berkelium and cerium during their extraction by ternary amines is explained by their different stability in this state, but not by the formation of complex compounds with nitrate ions

  16. The ozonolysis of primary aliphatic amines in single and multicomponent fine particles

    Science.gov (United States)

    Zahardis, J.; Geddes, S.; Petrucci, G. A.

    2007-10-01

    The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitro alkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3-(HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides was shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g. NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  17. Bases chimiosensorielles du comportement alimentaire chez les poissons

    Directory of Open Access Journals (Sweden)

    SAGLIO Ph.

    1981-07-01

    Full Text Available Le comportement alimentaire, indispensable à la survie de l'individu et donc de l'espèce, occupe à ce titre une position de première importance dans la hiérarchie des comportements fondamentaux qui tous en dépendent très étroitement. Chez les poissons, cette prééminence se trouve illustrée par l'extrême diversité des supports sensoriels impliqués et des expressions comportementales qui leur sont liées. A la suite d'un certain nombre de mises en évidence neurophysiologiques et éthologiques de l'importance du sens chimique (olfaction, gustation dans le comportement alimentaire des poissons, de très importants secteurs d'études électrophysiologiques et d'analyses physico-chimiques visant à en déterminer la nature exacte (en termes de substances actives se sont développés ces vingt dernières années. De tous ces travaux dont les plus avancés sont présentés ici, il ressort que les acides aminés de série L plus ou moins associés à d'autres composés de poids moléculaires < 1000 constituent des composés chimiques jouant un rôle déterminant dans le comportement alimentaire de nombreuses espèces de poissons carnivores.

  18. Studies on coordination and addition compounds and anti microbial activity of some mixed ligand complexes of Au(III), Mo(II), Co(II) and Cd(II) with dibasic acid and heterocyclic amines and addition compounds of As(III) and Sb(III) halides with benzamide and acetophenon

    International Nuclear Information System (INIS)

    Hossain, M.; Sultana, C.; Saidul Islam, M.; Zakaria, C.M.

    2008-06-01

    Three new mixed ligand complexes of Au(III) and Mo(II) with dibasic acid e.g., homophthalic acid, oxalic acid and heterocylic amines e.g., quinonine, iso-quinonine, bipyridine, Phenylanaline and the two new addition compounds of As(III) and Sb(III) halides with N-donor ligands viz. benzamide and acetophenone and one complex [Cd(DPH)(IQ) 2 ], where IQ = Iso-quinoline and DPH = Deprotonated phthalic acid have been prepared according to the procedure in the literature. Their conventional physical and chemical analyses have been done. Their antibacterial studies against nine gram positive and five gram negative pathogenic bacteria and antifungal activities against eight plant and three human fungi have been evaluated. Kanamycin and Nystatin have been used as a standard for carrying out experiments of antibacterial and antifungal activities, respectively. The minimum inhibitory concentration (MIC) values of these compounds, as antibiotic against two gram positive and two gram negative pathogenic bacteria, have also been carried out and in this case, Amoxacilin antibiotic has been used as a standard antibiotic. (author)

  19. Platinum-Catalyzed Terminal-Selective C(sp3)–H Oxidation of Aliphatic Amines

    Science.gov (United States)

    Lee, Melissa; Sanford, Melanie S.

    2016-01-01

    This paper describes the terminal-selective Pt-catalyzed C(sp3)–H oxidation of aliphatic amines without the requirement for directing groups. CuCl2 is employed as a stoichiometric oxidant, and the reactions proceed in high yield at Pt loadings as low as 1 mol %. These transformations are conducted in the presence of sulfuric acid, which reacts with the amine substrates in situ to form ammonium salts. We propose that protonation of the amine serves at least three important roles: (i) it renders the substrates soluble in the aqueous reaction medium; (ii) it limits binding of the amine nitrogen to Pt or Cu; and (ii) it electronically deactivates the C–H bonds proximal to the nitrogen center. We demonstrate that this strategy is effective for the terminal-selective C(sp3)–H oxidation of a variety of primary, secondary and tertiary amines. PMID:26439251

  20. Fishmeal with different levels of biogenic amines in Aquafeed: Comparison of feed protein quality, fish growth performance, and metabolism

    DEFF Research Database (Denmark)

    Jasour, Mohammad Sedigh; Wagner, Liane; Sundekilde, Ulrik Kræmer

    2018-01-01

    The current study investigated the effects of fishmeal quality (low (LB) and high (HB) levels of endogenous biogenic amines) and feed extrusion temperatures (100 and 130 °C) on protein oxidation indicators and amino acids racemization (AAR) in extruded fish feed. Furthermore, the study investigated......, secondary oxidation products, and racemized methionine correlated positively with a low content of biogenic amines, whereas the primary oxidation product, protein hydroperoxides, and in vivo AAs digestibility correlated positively with high content of biogenic amines. At an extrusion temperature of 100 °C......, the growth performance of the fish decreased when the content of biogenic amines increased. In contrast, at an extrusion temperature of 130 °C, the growth performance was unaffected by the level of biogenic amines. The latter could be a consequence of the higher level of protein oxidation of LB fishmeal...

  1. Intolerance to dietary biogenic amines: A review

    NARCIS (Netherlands)

    Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

  2. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

    Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

  3. Method for the production of primary amines

    NARCIS (Netherlands)

    Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

    2014-01-01

    The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

  4. Ecologie du phytoplancton du lac Kivu

    Directory of Open Access Journals (Sweden)

    Sarmento, H.

    2008-01-01

    Full Text Available Speciation within the African Coffee Pathogen. Cet article analyse s'il est avantageux d'utiliser le compost au lieu de l'engrais minéral pour produire la laitue dans la zone urbaine et péri-urbaine de Yaoundé. Les résultats de terrain montrent l'obtention de rendements et profits plus élevés lorsqu'on utilise le compost. Les résultats de la fonction de production Cobb-Douglas prouvent que l'utilisation du compost est statistiquement significative pour expliquer la variation de rendement de la laitue et que le compost est l'intrant le plus productif. D'autres résultats montrent que le compost fournit la matière organique utile au sol et que les besoins d'irrigation en eau de la culture sont réduits grâce à l'utilisation du compost. Par conséquent, malgré le fait que l'application du compost demande une main-d'oeuvre beaucoup plus élevée, son utilisation est généralement bénéfique pour les agriculteurs vivant aux alentours de Yaoundé. Les programmes de vulgarisation de cet intrant pour encourager son adoption devraient donc figurer parmi les points prioritaires dans la politique agricole du gouvernement camerounais.

  5. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    Science.gov (United States)

    Smith, R.E.; Dolbeare, F.A.

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

  6. Thermodynamics of mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)], E-mail: jagl@termo.uva.es; Mozo, Ismael; Garcia de la Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Riesco, Nicolas [Department of Chemical Engineering, Loughborough University, Loughborough, LE113TU Leicestershire (United Kingdom)

    2008-01-30

    Mixtures with dimethyl or trimethylpyridines and alkane, aromatic compound or 1-alkanol have been examined using different theories: DISQUAC, Flory, the concentration-concentration structure factor, S{sub CC}(0), or the Kirkwood-Buff formalism. DISQUAC represents fairly well the available experimental data, and improves theoretical calculations from Dortmund UNIFAC. Two important effects have been investigated: (i) the effect of increasing the number of methyl groups attached to the aromatic ring of the amine; (ii) the effect of modifying the position of the methyl groups in this ring. The molar excess enthalpy, H{sup E}, and the molar excess volume, V{sup E}, decrease in systems with alkane or methanol as follows: pyridine > 3-methylpyridine > 3,5-dimethylpyridine and pyridine > 2-methylpyridine > 2,4-dimethylpyridine > 2,4,6-trimethylpyridine, which has been attributed to a weakening of the amine-amine interactions in the same sequences. This is in agreement with the relative variation of the effective dipole moment, {mu}-bar, and of the differences between the boiling temperature of a pyridine base and that of the homomorphic alkane. For heptane solutions, the observed H{sup E} variation, H{sup E} (3,5-dimethylpyridine) > H{sup E} (2,4-dimethylpyridine) > H{sup E} (2,6-dimethylpyridine), is explained similarly. Calculations on the basis of the Flory model confirm that orientational effects become weaker in systems with alkane in the order: pyridine > methylpyridine > dimethylpyridine > trimethylpyridine. S{sub CC}(0) calculations show that steric effects increase with the number of CH{sub 3}- groups in the pyridine base, and that the steric effects exerted by methyl groups in positions 2 and 6 are higher than when they are placed in positions 3 and 5. The hydrogen bond energy in methanol mixtures is independent of the pyridine base, and it is estimated to be -35.2 kJ mol{sup -1}. Heterocoordination in these solutions is due in part to size effects. Their

  7. Étude de la technique d'échange ionique avec compétition. Cas du dépôt de platine sur support solide acide par échange cationique Research on the Ion Exchange Technique with Competition. Case of Platinum Deposit on a Solid Acid Support by Cation Exchange

    Directory of Open Access Journals (Sweden)

    Ribeiro F.

    2006-11-01

    Full Text Available Cet article présente une étude détaillée de la technique de dépôt de platine sur support acide par échange cationique avec compétition. Cette technique permet d'obtenir à la fois une dispersion quasi atomique et une répartition macroscopique homogène du métal sur la surface du solide. En l'absence de limitations diffusionnelles extra-granulaires, les résultats expérimentaux sont en bon accord avec les prévisions théoriques . This article is a detailed examination of the technique of depositing platinum on an acid support by cation exchange with compétition. This technique produces both a quasi-atomic dispersion and a homogeneous macroscopic distribution of the métal onthe surface of the solid. In the absence of extragranular diffusion limitations, experimental findings are in good agreement with theoretical predictions.

  8. Du Pont de Nemours

    NARCIS (Netherlands)

    Ros JPM; LAE

    1994-01-01

    Dit rapport over Du Pont de Nemours (produktie van o.a. chemische stoffen) is gepubliceerd binnen het Samenwerkingsproject Procesbeschrijvingen Industrie Nederland (SPIN). In het kader van dit project is informatie verzameld over industriele bedrijven of industriele processen ter ondersteuning

  9. Effect of salt-tolerant yeast of Candida versatilis and Zygosaccharomyces rouxii on the production of biogenic amines during soy sauce fermentation.

    Science.gov (United States)

    Qi, Wei; Hou, Li-Hua; Guo, Hong-Lian; Wang, Chun-Ling; Fan, Zhen-Chuan; Liu, Jin-Fu; Cao, Xiao-Hong

    2014-06-01

    This study aimed to enhance and improve the quality and safety of soy sauce. In the present work, the change of biogenic amines, such as histamine, tyramine, cadaverine, spermidine, was examined by the treatment of Candida versatilis and Zygosaccharomyces rouxii, and the influence of salt-tolerant yeast on biogenic amines was analysed during the whole fermentation process. The results showed that the content of biogenic amines was elevated after yeast treatment and the content of biogenic amines was influenced by using yeast. The dominating biogenic amine in soy sauce was tyramine. At the end of fermentation, the concentrations of biogenic amines produced by Zygosaccharomyces rouxii and Candida versatilis in the soy mash were 122.71 mg kg(-1) and 69.96 mg kg(-1) . The changes of biogenic amines in high-salt liquid soy mash during fermentation process indicated that a variety of biogenic amines were increased in the fermentation ageing period, which may be due to amino acid decarboxylation to form biogenic amines by yeast decarboxylase. The fermentation period of soy sauce should be longer than 5 months because biogenic amines began to decline after this time period. © 2013 Society of Chemical Industry.

  10. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    6 juil. 2007 ... La problématique du développement du secteur de l'artisanat en. Algérie a été très peu abordée par les chercheurs, qu'ils soient universitaires ou .... La loi a institué une taxe d'apprentissage dont le taux a été fixé à. 1% de la ...

  11. Les outils du CERN

    CERN Multimedia

    1999-01-01

    C'est le plus grand centre mondial de recherche en physique des particules. Les outils du Laboratoire, accélérateurs et détecteurs de particules, figurent parmi les instruments scientifiques les plus complexes au monde. Des prix Nobels ont d'ailleurs été attribués aux physiciens du CERN pour leurs développements.

  12. Bulletin du CRDI #127

    International Development Research Centre (IDRC) Digital Library (Canada)

    La mise à l'échelle de la recherche et de l'innovation en vue de créer un impact social constitue une priorité pour la communauté du développement. Toutefois ... Nous avons renouvelé notre soutien à la recherche auprès du gouvernement de l'Inde ... Des femmes étudient à l'École supérieure d'infotronique d'Haïti.

  13. Brain perfusion imaging with iodinated amines

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Traditional nuclear medicine brain study using 99m Tc pertechnetate, glucoheptonate or diethlenetriaminepentacetic acid (DTPA) and planar imaging has experienced a significant decline in the past 10 years. This is mainly due to the introduction of X-ray CT and more recently the nuclear magnetic resonance (NMR) imaging, by which detailed morphology of the brain, including the detection of breakdown of the blood-brain barrier, can be obtained. The nuclear medicine brain imaging is only prescribed as a complementary test when X-ray CT is negative or equivocal and clinical suspicion remains. The attention of nuclear medicine brain imaging has been shifted from the detection of the breakdown of the blood-brain barrier to the study of brain function-perfusion, metabolism, and receptor binding, etc. The functional brain imaging provides diagnostic information usually unattainable by other radiological techniques. In this article, the iodinated amines as brain perfusion imaging agents are reviewed. Potential clinical application of these agents is discussed

  14. Electrophysiological effects of trace amines on mesencephalic dopaminergic neurons

    Directory of Open Access Journals (Sweden)

    Ada eLedonne

    2011-07-01

    Full Text Available Trace amines (TAs are a class of endogenous compounds strictly related to classic monoamine neurotransmitters with regard to their structure, metabolism and tissue distribution. Although the presence of TAs in mammalian brain has been recognized for decades, until recently they were considered to be by-products of amino acid metabolism or as ‘false’ neurotransmitters. The discovery in 2001 of a new family of G protein-coupled receptors (GPCRs, namely trace amines receptors, has re-ignited interest in TAs. In particular, two members of the family, trace amine receptor 1 (TA1 and trace amine receptor 2 (TA2, were shown to be highly sensitive to these endogenous compounds. Experimental evidence suggests that TAs modulate the activity of catecholaminergic neurons and that TA dysregulation may contribute to neuropsychiatric disorders, including schizophrenia, attention deficit hyperactivity disorder, depression and Parkinson’s disease, all of which are characterised by altered monoaminergic networks. Here we review recent data concerning the electrophysiological effects of TAs on the activity of mesencephalic dopaminergic neurons. In the context of recent data obtained with TA1 receptor knockout mice, we also discuss the mechanisms by which the activation of these receptors modulates the activity of these neurons. Three important new aspects of TAs action have recently emerged: (a inhibition of firing due to increased release of dopamine; (b reduction of D2 and GABAB receptor-mediated inhibitory responses (excitatory effects due to dysinhibition; and (c a direct TA1 receptor-mediated activation of GIRK channels which produce cell membrane hyperpolarization. While the first two effects have been well documented in our laboratory, the direct activation of GIRK channels by TA1 receptors has been reported by others, but has not been seen in our laboratory (Geracitano et al., 2004. Further research is needed to address this point, and to further

  15. Oxidation of aromatic amines and diamines by OH radicals. Formation and ionization constants of amine cation radicals in water

    International Nuclear Information System (INIS)

    Hayon, E.; Rao, P.S.

    1975-01-01

    The one-electron oxidation by hydroxyl radicals of aromatic amines and diamines in water was studied using the fast-reaction technique of pulse radiolysis and kinetic absorption spectrophotometry. The following compounds were examined: N,N,N 1 ,N 1 - tetramethyl-p-phenylenediamine (TMPD), p-phenylenediamine (PD), N,N-dimethyl-p-phenylenediamene (DMPD), N,N,N 1 ,N 1 -tetramethylbenzidine (TMB), and diphenylamine (DPA). The main initial reaction of the OH radicals is suggested to be an addition to these compounds to give absorption spectra which absorb strongly in the visible and uv regions. These OH radical adducts decay by first-order kinetics and have lifetimes of approximately 5-50 μsec, dependent on the pH, buffer concentration, and the nature of the aromatic amines and diamines. They decay to give species with somewhat similar absorption spectra and extinction coefficients, which are very long lived in the absence of oxygen. The latter species are assigned to the cation radicals TMPD. + , PD. + , DMPD. + , TMB. + , and DPA. + . The OH radical adducts and the cation radicals have acid-base properties. The pK/sub a/ values of the cation radicals TMPDH. 2+ , PDH. 2+ , DMPDH. 2+ , TMBH. 2+ , and DPAH. 2+ were found to be 5.3, 5.9, 6.1, 5.1, and 4.2, respectively. The results indicate that these aromatic amines and diamines can be oxidized by free radicals to yield the corresponding cation radicals. (U.S.)

  16. Effect of pH and modifier-concentration on the solvent extraction of molybdenum with an alkyl amine

    International Nuclear Information System (INIS)

    Al-Siddique, F.R.; Adeler, I.; Huwyler, S.

    1980-07-01

    The results of the extraction behaviour of molybdenum in aqueous sulfuric acid solutions of an alkyl amine (amberlite LA-2) in kerosene under various pH and in the presence of various percentage of 1-octanol has been reported. The concentration of molybdenum employed was high enough to precipitate it partially during extraction as an amine-molybdenum complex. The maximum extraction coefficient was found to lie between pH 1.5-2.5. Presence of 1-octanol increased the extraction coefficient of molybdenum by increasing the solubility of the amine-molybdenum complex in the organic phase without changing the pH at the maximum extraction. (Auth.)

  17. Quantification of amine functional groups and their influence on OM/OC in the IMPROVE network

    Science.gov (United States)

    Kamruzzaman, Mohammed; Takahama, Satoshi; Dillner, Ann M.

    2018-01-01

    Recently, we developed a method using FT-IR spectroscopy coupled with partial least squares (PLS) regression to measure the four most abundant organic functional groups, aliphatic C-H, alcohol OH, carboxylic acid OH and carbonyl C=O, in atmospheric particulate matter. These functional groups are summed to estimate organic matter (OM) while the carbon from the functional groups is summed to estimate organic carbon (OC). With this method, OM and OM/OC can be estimated for each sample rather than relying on one assumed value to convert OC measurements to OM. This study continues the development of the FT-IR and PLS method for estimating OM and OM/OC by including the amine functional group. Amines are ubiquitous in the atmosphere and come from motor vehicle exhaust, animal husbandry, biomass burning, and vegetation among other sources. In this study, calibration standards for amines are produced by aerosolizing individual amine compounds and collecting them on PTFE filters using an IMPROVE sampler, thereby mimicking the filter media and collection geometry of ambient standards. The moles of amine functional group on each standard and a narrow range of amine-specific wavenumbers in the FT-IR spectra (wavenumber range 1 550-1 500 cm-1) are used to develop a PLS calibration model. The PLS model is validated using three methods: prediction of a set of laboratory standards not included in the model, a peak height analysis and a PLS model with a broader wavenumber range. The model is then applied to the ambient samples collected throughout 2013 from 16 IMPROVE sites in the USA. Urban sites have higher amine concentrations than most rural sites, but amine functional groups account for a lower fraction of OM at urban sites. Amine concentrations, contributions to OM and seasonality vary by site and sample. Amine has a small impact on the annual average OM/OC for urban sites, but for some rural sites including amine in the OM/OC calculations increased OM/OC by 0.1 or more.

  18. Tunable, chemoselective amination via silver catalysis.

    Science.gov (United States)

    Rigoli, Jared W; Weatherly, Cale D; Alderson, Juliet M; Vo, Brian T; Schomaker, Jennifer M

    2013-11-20

    Organic N-containing compounds, including amines, are essential components of many biologically and pharmaceutically important molecules. One strategy for introducing nitrogen into substrates with multiple reactive bonds is to insert a monovalent N fragment (nitrene or nitrenoid) into a C-H bond or add it directly to a C═C bond. However, it has been challenging to develop well-defined catalysts capable of promoting predictable and chemoselective aminations solely through reagent control. Herein, we report remarkable chemoselective aminations that employ a single metal (Ag) and a single ligand (phenanthroline) to promote either aziridination or C-H insertion by manipulating the coordination geometry of the active catalysts.

  19. Biogenic amines and radiosensitivity of solitary cells

    International Nuclear Information System (INIS)

    Goncharenko, E.N.

    1978-01-01

    Different stability of cells to ionizing radiation is considered from a position of the ''elevated biochemical radioresistance background'' concept. Experimental evidence presented indicates an important role of endogenic amines (serotonin and histamine) possessing radioprotector properties in the cell radioresistance formation. The concept about their effect as being solely a result of circulatory hypoxia is critically discussed. The experimental results favor the existence of a ''cellular'' component, along with the ''hypoxic'' one, in the mechanism of action of biogenic amines. These compounds can affect the initial stages of peroxide oxidation of lipids, thereby favoring a less intensive oxidation induced by radiation. Biogenic amines can also exert influence on the cyclic nucleotide system

  20. Enrichment Mechanism of Semiconducting Single-walled Carbon Nanotubes by Surfactant Amines

    Science.gov (United States)

    Ju, Sang-Yong; Utz, Marcel; Papadimitrakopoulos, Fotios

    2009-01-01

    Utilization of single-walled carbon nanotubes (SWNTs) in high-end applications hinges on separating metallic (met-) from semiconducting (sem-) SWNTs. Surfactant amines, like octadecylamine (ODA) have proven instrumental for the selective extraction of sem-SWNTs from tetrahydrofuran (THF) nanotube suspensions. The chemical shift differences along the tail of an asymmetric, diacetylenic surfactant amine were used to probe the molecular dynamics in the presence and absence of nanotubes via NMR. The results suggest that the surfactant amine head is firmly immobilized onto the nanotube surface together with acidic water, while the aliphatic tail progressively gains larger mobility as it gets farther from the SWNT. X-ray and high-resolution TEM studies indicate that the sem-enriched sample is populated mainly by small nanotube bundles containing ca. three SWNTs. Molecular simulations in conjunction with previously determined HNO3/H2SO4 oxidation depths for met- and sem-SWNTs indicate that the strong pinning of the amine surfactants on the sem-enriched SWNTs bundles is a result of a well-ordered arrangement of nitrate/amine salts separated with a monomolecular layer of H2O. Such continuous 2D arrangement of nitrate/amine salts shields the local environment adjacent to sem-enriched SWNTs bundles and maintains an acidic pH that preserves nanotube oxidation (i.e. SWNTn+). This, in turn, results in strong interactions with charge-balancing NO3- counter ions that through their association with neutralized surfactant amines provide effective THF dispersion and consequent sem-enrichment. PMID:19397291

  1. The application experience of ethanol amine at KORI unit 4

    International Nuclear Information System (INIS)

    Lee, Sang-hak; Park, Jong-il; Lee, Jae-won; Kim, Guem-Soo

    2004-01-01

    The secondary system water chemistry in the KORI PWR units has been well controlled by reducing the corrosion in the tubes of the steam generators; the pH agent has been changing from ammonia to ethanol amine (ETA) (1.8 to 2.0 ppm). For example, the iron concentration in the system was reduced by 40 to 70% compared with ammonia treatment. The paper presents the detailed information, such as ETA injection concentration and the variation of pH, concentration of organic acid products, and irons in the system, and a significant change on sludge after ETA application. (S. Ohno)

  2. Anodic selective functionalization of cyclic amine derivatives

    OpenAIRE

    Onomura, Osamu

    2012-01-01

    Anodic reactions are desirable methods from the viewpoint of Green Chemistry, since no toxic oxidants are necessary for the oxidation of organic molecules. This review introduces usefulness of anodic oxidation and successive reaction for selective functionalization of cyclic amine derivatives.

  3. Transition metals in the amination of chloroarenes

    Energy Technology Data Exchange (ETDEWEB)

    Serdyuk, O V [Leibniz-Institut fuer Katalyse an der Universitaet Rostock (Germany); Abaev, Vladimir T [North-Ossetia State University, Vladikavkaz (Russian Federation)

    2009-11-30

    The review is devoted to the catalytic amination of chloroarenes and chlorohetarenes. Examples of the formation of the C-N bond in the presence of iron-, nickel- and copper-based catalytic systems are given.

  4. Effet du Pediococcus acidilactici sur le bilan lipidique sanguin du ...

    African Journals Online (AJOL)

    Les résultats relatifs aux performances zootechniques ont montré que l'addition du probiotique a amélioré significativement le gain de poids pendant la phase de croissance se traduisant par un indice de consommation meilleur. Les dosages du cholestérol total, des triglycérides, du HDL et du LDL ont été déterminés à la ...

  5. Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

    Science.gov (United States)

    Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

    2012-01-14

    Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

  6. Color test for selective detection of secondary amines on resin and in solution

    DEFF Research Database (Denmark)

    Boas, Ulrik; Mirsharghi, Sahar

    2014-01-01

    Resins for solid-phase synthesis give orange to red-brown resin beads selectively when secondary amines are present on the resin when treated with a solution of acetaldehyde and an Fmoc-amino acid in NMP. The method shows good specificity and gives colorless beads when exposed to a variety of oth...

  7. The N-terminus of amine oxidase of Hansenula polymorpha contains a peroxisomal targeting signal

    NARCIS (Netherlands)

    Faber, Klaas Nico; Keizer-Gunnink, Ineke; Pluim, Dick; Harder, Willem; AB, Geert; Veenhuis, Marten

    1995-01-01

    Here we describe the identification of the targeting sequence of peroxisomal amine oxidase (AMO) of H. polymorpha. Deletion analysis revealed that essential targeting information is located within the extreme N-terminal 16 amino acids. Moreover, this sequence can direct a reporter protein to the

  8. Synthesis and bioelectrochemical behavior of aromatic amines.

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Bolte, Michael; McKee, Vickie

    2017-12-01

    Four aromatic amines 1-amino-4-phenoxybenzene (A 1 ), 4-(4-aminophenyloxy) biphenyl (A 2 ), 1-(4-aminophenoxy) naphthalene (A 3 ) and 2-(4-aminophenoxy) naphthalene (A 4 ) were synthesized and characterized by elemental, spectroscopic (FTIR, NMR), mass spectrometric and single crystal X-ray diffraction methods. The compounds crystallized in monoclinic crystal system with space group P2 1 . Intermolecular hydrogen bonds were observed between the amine group and amine/ether acceptors of neighboring molecules. Electrochemical investigations were done using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). CV studies showed that oxidation of aromatic amines takes place at about 0.9 V (vs. Ag/AgCl) and the electron transfer (ET) process has irreversible nature. After first scan reactive intermediate were generated electrochemically and some other cathodic and anodic peaks also appeared in the succeeding scans. DPV study revealed that ET process is accompanied by one electron. DNA binding study of aromatic amines was performed by CV and UV-visible spectroscopy. These investigations revealed groove binding mode of interaction of aromatic amines with DNA. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Metal-free, mild, nonepimerizing, chemo- and enantio- or diastereoselective N-alkylation of amines by alcohols via oxidation/imine-iminium formation/reductive amination: a pragmatic synthesis of octahydropyrazinopyridoindoles and higher ring analogues.

    Science.gov (United States)

    Khan, Imran A; Saxena, Anil K

    2013-12-06

    A mild step and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure has been developed via oxidation/imine-iminium formation/reduction cascade using TEMPO-BAIB-HEH-Brønsted acid catalysis in DMPU as solvent and a stoichiometric amount of amine. The optimized conditions were further extended for the nonenzymatic kinetic resolution of the chiral amine thus formed under nonenzymatic in situ hydrogen-transfer conditions using VAPOL-derived phosphoric acid (VAPOL-PA) as the Brønsted acid catalyst. The enantioselective cascade of the presented reaction was successfully utilized in the synthesis of octahydropyrazinopyridoindole and its higher ring analogues.

  10. Les mots du jazz

    OpenAIRE

    Roueff, Olivier

    2007-01-01

    L’ouvrage d’André Schaeffner constitue la première analyse savante du jazz (1926). Il a marqué une étape importante dans le processus de réinvention du jazz en France en contribuant notamment, par sa réception et les polémiques qu’il a suscitées, à transformer l’identification du jazz d’une musique « américaine » à une musique « noire-américaine » (c’est-à-dire aux « racines » africaines). Les analyses proposées dans cet ouvrage, alors qu’elles désignaient des musiques que la critique de jazz...

  11. Evaluation of biogenic amines and microbial counts throughout the ripening of goat cheeses from pasteurized and raw milk.

    Science.gov (United States)

    Novella-Rodríguez, Sonia; Veciana-Nogués, M Teresa; Roig-Sagués, Artur X; Trujillo-Mesa, Antonio J; Vidal-Carou, M Carmen

    2004-05-01

    The effect of the hygienic quality of milk on changes in microbial counts and biogenic amine content was evaluated during ripening of goat cheeses manufactured from pasteurized and raw milks at 1, 14, 30, 60 and 90 d. The original milk, rennet, curd and whey were also included in the study. The pH, salt content and extent of proteolysis in the cheese were also evaluated. Spermidine and spermine were the main amines in raw milk, while they were minor amines in cheeses. Other amines increased markedly during ripening, tyramine being the main amine in cheese made from raw milk and cadaverine and putrescine in those produced from pasteurized milk. Enterobacteriaceae counts decreased during ripening whereas those of lactic acid bacteria increased, especially lactobacilli and enterococci. Cheese made from raw milk showed higher microbial counts during ripening than those made from pasteurized milk, especially for Enterobacteriaceae and enterococci, counts being 2 or 3 log units higher. Raw milk cheese showed remarkably higher biogenic amines compared with pasteurized milk cheeses. Therefore, pasteurization of milk causes a decrease in final biogenic amine content of cheese as a result of the reduction of its microbial counts.

  12. fibrosarcome du larynx

    African Journals Online (AJOL)

    pie du lit tumoral est employée comme complément thé- rapeutique [9] alors que la chimiothérapie est générale- ment indiquée dans les formes métastatiques. Le pronos- tic dépend essentiellement du degré de différentiation his- tologique. En fait, le fibrosarcome bien différencié est caractérisé par la fréquence de récidive ...

  13. du Chott Marouane

    African Journals Online (AJOL)

    plancton de 90 µm de vide de maille. Ils ont été conservés dans du formol à 5%. L'identification de l'espèce est basée sur des critères morphologiques [20]: la forme des furcas, les lobes frontaux des antennes des mâles, de l'organe copulateur (pénis) et du sac ovigère. Le comptage des soies furcales a été réalisé. L'étude ...

  14. Analysis of irradiated biogenic amines by computational chemistry and spectroscopy

    International Nuclear Information System (INIS)

    Oliveira, Jorge L.S.P.; Borges Junior, Itamar; Cardozo, Monique; Souza, Stefania P.; Lima, Antonio L.S.; Lima, Keila S.C.

    2011-01-01

    Biogenic Amines (B A) are nitrogenous compounds able to cause food poisoning. In this work, we studied the tyramine, one of the most common BA present in foods by combining experimental measured IR (Infrared) and GC/MS (Gas Chromatograph / Mass Spectrometry) spectra and computational quantum chemistry. Density Functional Theory (DFT) and the Deformed Atoms in Molecules (DMA) method was used to compute the partition the electronic densities in a chemically-intuitive way and electrostatic potentials of molecule to identify the acid and basic sites. Trading pattern was irradiated using a Cs 137 radiator, and each sample was identified by IR and GC/MS. Calculated and experimental IR spectra were compared. We observed that ionizing gamma irradiation was very effective in decreasing the population of standard amine, resulting in fragments that could be rationalized through the quantum chemistry calculations. In particular, we could locate the acid and basic sites of both molecules and identify possible sites of structural weaknesses, which allowed to propose mechanistic schemes for the breaking of chemical bonds by the irradiation. Moreover, from this work we hope it will be also possible to properly choose the dose of gamma irradiation which should be provided to eliminate each type of contamination. (author)

  15. Bioreducible poly(amido amine)s for non-viral gene delivery

    NARCIS (Netherlands)

    Lin, C.

    2008-01-01

    This thesis describes the design and development of bioreducible poly(amido amine)s as non-viral vectors for gene delivery in vitro and in vivo. The structural influences of these polymers on their physico-chemical properties and gene delivery properties, transfection capability and cytotoxicity in

  16. Nucleic Acids and Protein Metabolism of Bone Marrow Cells Studied by Means of Tritiumlabelled Precursors; Etude du Metabolisme des Acides Nucleiques et des Proteines dans les Cellules de la Moelle Osseuse, a l'Aide de Precurseurs Trities; 0418 0437 0443 0414 ; Estudio con Ayuda de Precursores Tritiados del Metabolismo de los acidos Nucleicos y de las Proteinas en las Celulas de la Medula Osea;

    Energy Technology Data Exchange (ETDEWEB)

    Gavosto, F. [Istituto di Clinica Medica Generale e Centro di Studi Fisico-Biologici, Universita de Turin, Turin (Italy)

    1962-02-15

    avantages que presente l'emploi de composes trities pour l'autoradiographie. En effet les electrons du tritium ont une energie maximum de 0,018 MeV, correspondant a un parcours d'environ 1 micron dans une emulsion photographique, ce qui permet d'obtenir le plus fort degre de resolution possible aux niveaux cellulaire et infracellulaire. Ce phenomene est particulierement utile pour l'etude du metabolisme de tissus comme la moelle osseuse, qui sont composes de differents types de cellules a divers stades de differenciation. Cette technique a ete utilisee pour l'etude du metabolisme des acides nucleiques et des proteines des cellules normales et leucemiques de la moelle osseuse. L'auteur a etudie le metabolisme de l'ADN a l'aide d'un precurseur specifique, la thymidine tritiee. Il a decele certaines differences importantes dans les pourcentages de cellules marquees, en comparant les elements normaux et leucemiques au meme stade de maturation. Il a constate, en particulier, que dans les cellules d'un sujet atteint de leucemie aiguee, le taux d'incorporation de la thymidine etait beaucoup plus faible, ce qui prouve une diminution de la capacite de proliferation de ces cellules par rapport aux myeloblastes normaux. L'auteur a utilise la meme technique pour etudier le metabolisme de l'ARN et des proteines, a l'aide des precurseurs suivants: uridine, leucine et phenylalanine tritiees. Il est maintenant admis en biologie cellulaire qu'il existe un rapport etroit entre le metabolisme de l'ARN et celui des proteines; l'auteur a demontre qu'il existait egalement un rapport constant entre l'incorporation de l'uridine et des acides amines, dans les cellules normales de la moelle osseuse. Dans les cellules de sujets atteints de leucemie aiguee, l'incorporation de l'ARN et des precurseurs protidiques, bien qu'elle differe dans chaque cas, est toujours nettement plus faible. De plus, le rapport entre l'incorporation de l'uridine et celle des amino-acides varie constamment dans ces cellules

  17. Click and chemically triggered declick reactions through reversible amine and thiol coupling via a conjugate acceptor

    Science.gov (United States)

    Diehl, Katharine L.; Kolesnichenko, Igor V.; Robotham, Scott A.; Bachman, J. Logan; Zhong, Ye; Brodbelt, Jennifer S.; Anslyn, Eric V.

    2016-10-01

    The coupling and decoupling of molecular units is a fundamental undertaking of organic chemistry. Herein we report the use of a very simple conjugate acceptor, derived from Meldrum's acid, for the sequential ‘clicking’ together of an amine and a thiol in aqueous conditions at neutral pH. Subsequently, this linkage can be ‘declicked’ by a chemical trigger to release the original amine and thiol undisturbed. The reactivity differs from that of other crosslinking agents because the selectivity for sequential functionalization derives from an altering of the electrophilicity of the conjugate acceptor on the addition of the amine. We describe the use of the procedure to modify proteins, create multicomponent libraries and synthesize oligomers, all of which can be declicked to their starting components in a controlled fashion when desired. Owing to the mild reaction conditions and ease of use in a variety of applications, the method is predicted to have wide utility.

  18. Continuous-flow oxidative cyanation of primary and secondary amines using singlet oxygen.

    Science.gov (United States)

    Ushakov, Dmitry B; Gilmore, Kerry; Kopetzki, Daniel; McQuade, D Tyler; Seeberger, Peter H

    2014-01-07

    Primary and secondary amines can be rapidly and quantitatively oxidized to the corresponding imines by singlet oxygen. This reactive form of oxygen was produced using a variable-temperature continuous-flow LED-photoreactor with a catalytic amount of tetraphenylporphyrin as the sensitizer. α-Aminonitriles were obtained in good to excellent yields when trimethylsilyl cyanide served as an in situ imine trap. At 25°C, primary amines were found to undergo oxidative coupling prior to cyanide addition and yielded secondary α-aminonitriles. Primary α-aminonitriles were synthesized from the corresponding primary amines for the first time, by an oxidative Strecker reaction at -50 °C. This atom-economic and protecting-group-free pathway provides a route to racemic amino acids, which was exemplified by the synthesis of tert-leucine hydrochloride from neopentylamine. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Introduction of various amine groups onto polyethylene bead prepared by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Kim, M.S.; Choi, S.H.; Lee, K.P.

    2002-01-01

    Complete text of publication follows. Radiation-induced graft polymerization is a good method for modification of chemical and physical properties of polymeric materials because it can endow properties such as membrane quality, ion exchange, blood compatibility, dyeability, protein adsorption, and immobilization of bioactive materials. Polyethylene microbead is very useful material due to the following advantages; low price, simple purchase, high sensitivity, and simple analysis. On the other hand, the epoxy group of the glycidyl methacrylate (GMA) can easily be converted to the various functional groups such as amines, alcohols, phosphoric acid, sulfonic acid, and amino acid, etc. Cyclodextrin have been applied universally in various industries such as foods, cosmetics, pharmaceutical industry, analytical chemistry, and chemical industry. In order to obtain cyclodextrins, polyethylene microbead with the epoxy group were prepared by radiation-induced graft polymerization of GMA onto polyethylene microbead. The physical and chemical properties of the GMA-induced polyethylene microbeads were investigated by IR, thermal analysis (TGA/DSC), and SEM, respectively. Subsequently, the various amine groups such as diethylamine. diethylenetriamine, triethylamine, triethylenetetramine, and 1,6-hexanediamine were induced onto the epoxy group in polyethylene microbead. Finally, cyclodextrin glucanotransferase were immobilized onto polyethylene microbead with various amines under the various experimental conditions, such as pH, amin content, immobilization time, and etc. The activity of CGTase-immobilized polyethylene microbead was determined by Phenolphthein method. The production of the cyclodextrins from starch is in progress

  20. les cahiers du cread

    African Journals Online (AJOL)

    Our Journal “les cahiers du cread” is a quarterly economic review publishing original findings of empirical research and theoretical debates on fields pertaining to our mission coverage (Macro Economics, Industrial Economics and Firms, Human Development & Social Economics, Agriculture & Environment). Other websites ...

  1. Dicarbonic acid anilides containing radioactive iodine (iodine 131, 123, 125, or 132) as well as their metal and amine salts; methods for the preparation of these compounds and of radioactive functional diagnostics containing them

    International Nuclear Information System (INIS)

    Buttermann, G.

    1976-01-01

    A method for the preparation of dicarbonic acid anilides containing radioactive iodine is described. The initial substances are N,N dimethyl-p-toluene sulfonamide, N,N bis-dimethyl aminosulfon, or dimethyl sulfon, or mixtures of these, which are heated in aqueous solution or in a melt with an alkali or alkaline earth radioiodide as carrier-free as possible. From the water-soluble salts of the obtained iodine-labelled dicarbonic acid anilides aqueous solutions are produced with 1 mg up to 5 g iodine-labelled dicarbonic acid anilide per 10 ml and an activity of 0.025 and 25 mCi per ml with physiologically compatible bases as radioactive functional diagnostics. (RB) [de

  2. Spectroscopic Studies of the Chan-Lam Amination: A Mechanism-Inspired Solution to Boronic Ester Reactivity.

    Science.gov (United States)

    Vantourout, Julien C; Miras, Haralampos N; Isidro-Llobet, Albert; Sproules, Stephen; Watson, Allan J B

    2017-04-05

    We report an investigation of the Chan-Lam amination reaction. A combination of spectroscopy, computational modeling, and crystallography has identified the structures of key intermediates and allowed a complete mechanistic description to be presented, including off-cycle inhibitory processes, the source of amine and organoboron reactivity issues, and the origin of competing oxidation/protodeboronation side reactions. Identification of key mechanistic events has allowed the development of a simple solution to these issues: manipulating Cu(I) → Cu(II) oxidation and exploiting three synergistic roles of boric acid has allowed the development of a general catalytic Chan-Lam amination, overcoming long-standing and unsolved amine and organoboron limitations of this valuable transformation.

  3. BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2015-02-01

    Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

  4. Modification and characterization of sites giving acid cracking on aluminium oxide supports; Modification et caracterisation des sites responsables du craquage acide sur des supports a base d`alumine

    Energy Technology Data Exchange (ETDEWEB)

    Guillaume, D

    1997-10-23

    The aim of this work is to characterize the surface acid properties of {gamma} alumina, especially the nature, the amount, the strength and the environment of acid sites. The techniques that have been used are: the thermo-desorption of trimethyl-phosphine followed by {sup 31}P MAS NMR, the infrared spectroscopy, the n-heptane cracking, the modification of {gamma} alumina by the addition of chlorine, silicon and alkali (K{sup +}, Na{sup +}), alkaline-earths (Mg{sup 2+}, Ca{sup 2+}), lanthanum (La{sup 3+}) cations. The combination of these techniques has allowed to identify the surface acid properties of {gamma} alumina through the n-heptane transformation reactions under reforming conditions. We have shown that Lewis acidity is responsible for cracking reactions leading to C{sub 1}-C{sub 6} and C{sub 2}-C{sub 5} whereas the cracking of n-heptane producing C{sub 3}-C{sub 4} is due to Broensted acid sites. The isomerization and cyclization reactions both require weaker Broensted acid sites than cracking leading to C{sub 3}-C{sub 4}. The mechanisms involved in the formation of products of these reactions have been identified. Despite the complexity of surface acid properties of {gamma} alumina, this study has determined the environment of catalytically active sites, considering the presence of cation vacancies. (author) 206 refs.

  5. Solid-phase reductive amination for glycomic analysis.

    Science.gov (United States)

    Jiang, Kuan; Zhu, He; Xiao, Cong; Liu, Ding; Edmunds, Garrett; Wen, Liuqing; Ma, Cheng; Li, Jing; Wang, Peng George

    2017-04-15

    Reductive amination is an indispensable method for glycomic analysis, as it tremendously facilitates glycan characterization and quantification by coupling functional tags at the reducing ends of glycans. However, traditional in-solution derivatization based approach for the preparation of reductively aminated glycans is quite tedious and time-consuming. Here, a simpler and more efficient strategy termed solid-phase reductive amination was investigated. The general concept underlying this new approach is to streamline glycan extraction, derivatization, and purification on non-porous graphitized carbon sorbents. Neutral and sialylated standard glycans were utilized to test the feasibility of the solid-phase method. As results, almost complete labeling of those glycans with four common labels of aniline, 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA) and 2-amino-N-(2-aminoethyl)-benzamide (AEAB) was obtained, and negligible desialylation occurred during sample preparation. The labeled glycans derived from glycoproteins showed excellent reproducibility in high performance liquid chromatography (HPLC) and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Direct comparisons based on fluorescent absorbance and relative quantification using isotopic labeling demonstrated that the solid-phase strategy enabled 20-30% increase in sample recovery. In short, the solid-phase strategy is simple, reproducible, efficient, and sensitive for glycan analysis. This method was also successfully applied for N-glycan profiling of HEK 293 cells with MALDI-TOF MS, showing its attractive application in the high-throughput analysis of mammalian glycome. Published by Elsevier B.V.

  6. Comparaison du filtre adaptatif RIF et du filtre a base de reseau de ...

    African Journals Online (AJOL)

    Comparaison du filtre adaptatif RIF et du filtre a base de reseau de neurones pour le filtrage du courant de reference pour la commande du filtre actif parallele. C Benachaiba, A Bassou, B Mazari ...

  7. Transglutaminase-catalyzed amination of pea protein peptides using the biogenic amines histamine and tyramine.

    Science.gov (United States)

    Lu, Xinyao; Hrynets, Yuliya; Betti, Mirko

    2017-06-01

    Biogenic amines (BAs) are produced by the enzymatic decarboxylation of amino acids, and are well-known for their toxicity to humans. This study describes a new method using microbial transglutaminase (MTGase) to covalently link BAs such as histamine (HIS) and tyramine (TYR) to the glutamine residues of alcalase-hydrolyzed pea protein (PPH). The incubation of PPH and HIS and TYR in the presence of MTGase at 37 °C led to the formation of conjugates, as determined by liquid chromatography, after derivatization with dansyl chloride. Seventy-six % of HIS and 65% of TYR were covalently incorporated to PPH by MTGase. The incubation of PPH and TYR in the presence of MTGase exhibited a 52% DPPH radical scavenging activity at 10 mg mL -1 . Conjugation via MTGase improved the antioxidant status by reducing lipid peroxidation. This study emphasizes that the application of MTGase can effectively reduce histamine and tyramine content while simultaneously enhancing antioxidative capacity of PPH. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Pru du 2S albumin or Pru du vicilin?

    Science.gov (United States)

    Garino, Cristiano; De Paolis, Angelo; Coïsson, Jean Daniel; Arlorio, Marco

    2015-06-01

    A short partial sequence of 28 amino acids is all the information we have so far about the putative allergen 2S albumin from almond. The aim of this work was to analyze this information using mainly bioinformatics tools, in order to verify its rightness. Based on the results reported in the paper describing this allergen from almond, we analyzed the original data of amino acids sequencing through available software. The degree of homology of the almond 12kDa protein with any other known 2S albumin appears to be much lower than the one reported in the paper that firstly described it. In a publicly available cDNA library we discovered an expressed sequence tag which translation generates a protein that perfectly matches both of the sequencing outputs described in the same paper. A further analysis indicated that the latter protein seems to belong to the vicilin superfamily rather than to the prolamin one. The fact that also vicilins are seed storage proteins known to be highly allergenic would explain the IgE reactivity originally observed. Based on our observations we suggest that the IgE reactive 12kDa protein from almond currently known as Pru du 2S albumin is in reality the cleaved N-terminal region of a 7S vicilin like protein. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Absorption mechanism study of benzoic acid on calcite. Influence on the wettability; Etude du mecanisme d`absorption de l`acide benzoique sur la calcite. Incidence sur la mouillabilite

    Energy Technology Data Exchange (ETDEWEB)

    Legens, Ch

    1997-12-03

    A pure carbonate rock is strongly water-wet whereas oil accumulations study shows that most of carbonate reservoirs are oil-wet or of mixed-wettability. This is one of the main difficulties to extract crude oil. This change of behavior is due to the adsorption of some crude oil compounds on the mineral surface. We have mainly studied the interactions between acid molecules by adsorption on a calcite powder in an organic phase (benzoic acid and lauric acid) and in an aqueous phase (benzoic acid and lauric sodium salt). The technics which enabled us to define and characterize adsorption are thermogravimetry infrared diffuse reflection and thermal analysis with controlled kinetic linked to a mass spectrometer. Molecular modelling calculations have completed these analysis. It has been showed that when crude oil fills the biggest pores of the reservoir rock, the aqueous film is unstable and acids adsorb via ionic bonds on mineral calcium ions. Wettability is evaluated thanks to contact angle measurements of a water droplet deposited on a compacted powder pellet. Calcite wettability changes were all the greater as hydro-carbonated chains were longer, as it confers molecule hydrophobia. It has been also investigated acid molecules diffusion from the organic to the aqueous phase which saturates the smallest pores. Molecules which are able to diffuse from the first to the second medium do not adsorb on the surface. As a consequence, carbonate rock wettability changes require a direct contact between crude oil and mineral that involves aqueous film instability. (author) 128 refs.

  10. Base metal dehydrogenation of amine-boranes

    Science.gov (United States)

    Blacquiere, Johanna Marie [Ottawa, CA; Keaton, Richard Jeffrey [Pearland, TX; Baker, Ralph Thomas [Los Alamos, NM

    2009-06-09

    A method of dehydrogenating an amine-borane having the formula R.sup.1H.sub.2N--BH.sub.2R.sup.2 using base metal catalyst. The method generates hydrogen and produces at least one of a [R.sup.1HN--BHR.sup.2].sub.m oligomer and a [R.sup.1N--BR.sup.2].sub.n oligomer. The method of dehydrogenating amine-boranes may be used to generate H.sub.2 for portable power sources, such as, but not limited to, fuel cells.

  11. Catalyst for hydrogen-amine D exchange

    International Nuclear Information System (INIS)

    Holtslander, W.J.; Johnson, R.E.

    1976-01-01

    A process is claimed for deuterium isotopic enrichment (suitable for use in heavy water production) by amine-hydrogen exchange in which the exchange catalyst comprises a mixture of alkyl amides of two metals selected from the group consisting of the alkali metals. Catalyst mixtures comprising at least one of the alkali amides of lithium and potassium are preferred. At least one of the following benefits are obtained: decreased hydride formation, decreased thermal decomposition of alkyl amide, increased catalyst solubility in the amine phase, and increased exchange efficiency. 11 claims

  12. Corrosion inhibition of brass by aliphatic amines

    International Nuclear Information System (INIS)

    Taha, K. K.; Sheshadri, B. S; Ahmed, M. F.

    2005-01-01

    Aliphatic amines hexylamine (HCA), octylamine (OCA) and decylamine (DCA) have been used as corrosion inhibitors for (70/30) brass in 0.I M HCIO 4 . The inhibitor efficiency (%P) calculated using weight loss, Tafel extrapolation, linear polarization and impedance methods was found to be in the order DCA> OCA> HCA. These adsorb on brass surface following bockris-swinkels' isotherm. DCA, OCA and HCA displaced 4, 3 and 2 molecules of water from interface respectively. Displacement of water molecules brought a great reorganization of double layer at the interface. These amines during corrosion form complexes with dissolved zinc and copper ions.(Author)

  13. Selective amine catalysed steroidal dimerization

    Indian Academy of Sciences (India)

    of cholesterol is the formation of a green colour in concentrated sulphuric acid, and this was shown to be due to a polyenyl steroidal dimer carbocation.7–9 Many dimeric and oligomeric steroids exhibit interesting micellular, detergent and liquid crystal behaviour.10,11. Most of the steroidal dimmers are also well-known.

  14. Enantioselective catalytic syntheses of alpha-branched chiral amines

    DEFF Research Database (Denmark)

    Brase, S.; Baumann, T.; Dahmen, S.

    2007-01-01

    Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

  15. SEDIMENT-ASSOCIATED REACTIONS OF AROMATIC AMINES. 2. QSAR DEVELOPMENT

    Science.gov (United States)

    The fate of aromatic amines in soils and sediments is dominated by irreversible binding through nucleophilic addition and oxidative radical coupling. Despite the common occurrence of the aromatic amine functional group in organic chemicals, the molecular properties useful for pr...

  16. Le ministre du Commerce international du Canada rencontre des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    17 juil. 2017 ... La promotion de l'entrepreneuriat, la façon dont le commerce peut profiter aux femmes et à leur famille, et la création d'emplois pour les plus vulnérables étaient au coeur de la discussion en table ronde du ministre du Commerce international du Canada, l'honorable François-Philippe Champagne, et des ...

  17. Extraction and determination of biogenic amines in fermented sausages and other meat products using reversed-phase-HPLC.

    Science.gov (United States)

    Straub, B; Schollenberger, M; Kicherer, M; Luckas, B; Hammes, W P

    1993-09-01

    A convenient method is described for the analysis of biogenic amines (BA) by means of reversed-phase-HPLC. The method is characterized by multi-channel UV detection (diodearray), subsequent post-column derivatization with o-phthaldialdehyde and 3-mercaptopropionic acid, and fluorescence detection. For the analysis of meat products and especially fermented sausages an optimized perchloric acid extraction process was introduced to determine putrescine, cadaverine, histamine, tyramine and 2-phenylethylamine. BA recoveries from meat ranged between 96 and 113% with a detection limit for amines of 0.5 mg/kg.

  18. Portage vaginal du streptocoque du groupe B chez la femme ...

    African Journals Online (AJOL)

    Introduction: le streptocoque du groupe B est le principal agent impliqué dans les infections materno-fœtales, les septicémies et les méningites du nouveau-né à terme. L'objectif est de déterminer le taux de portage maternel du streptocoque du groupe B (SGB) à terme. Méthodes: un prélèvement vaginal a été réalisé de ...

  19. Aux origines du monde

    CERN Multimedia

    2004-01-01

    "C'est l'histoire d'une aventure humaine, scientifique, international qui a vu le jour il y a cinquante ans, aux confins de la Suisse et du département de l'Ain. Le plus grand laboratoire de physique des particules du monde, le Cern, a été fondé en 1954. Les festivités organisées à l occasion de cet anniversaire connaîtront leur point d'orgue le 16 octobre prochain, avec portes-ouvertes, accueil de personallités et inauguration d'un monumnet spécifique, le Globe de l'innovation" (2 pages)

  20. CHOEUR DU CERN

    CERN Multimedia

    CHOEUR DU CERN

    2010-01-01

    Les répétitions du chœur du CERN reprendront le mercredi 15 septembre à 20.00 heures à l’amphithéâtre principal – bâtiment 500. Au programme la préparation de notre concert de Noël avec la Missa Brevis, KV115, de Léopold Mozart et de la musique de Noël d’Europe. Les personnes qui aiment chanter, notamment des sopranes et des ténors, sont les bienvenues. Pour tout contact s’adresser à : Baudouin Bleus - (tél.CERN 767 82 44) -(baudouin.bleus@cern.ch) ou Martin Gatehouse ( martin.gatehouse@wanadoo.fr) ou Jean-Paul Diss (jean-pauldiss@wanadoo.fr).  

  1. Factors Influencing Biogenic Amines Accumulation in Dairy Products

    Science.gov (United States)

    Linares, Daniel M.; del Río, Beatriz; Ladero, Victor; Martínez, Noelia; Fernández, María; Martín, María Cruz; Álvarez, Miguel A.

    2012-01-01

    Fermented foods are among the food products more often complained of having caused episodes of biogenic amines (BA) poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain potentially harmful levels of BA, specially tyramine, histamine, and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report all those elaboration and processing technological aspects affecting BA biosynthesis and accumulation in dairy foods. Improved knowledge of the factors involved in the synthesis and accumulation of BA should lead to a reduction in their incidence in milk products. Synthesis of BA is possible only when three conditions converge: (i) availability of the substrate amino acids; (ii) presence of microorganisms with the appropriate catabolic pathway activated; and (iii) environmental conditions favorable to the decarboxylation activity. These conditions depend on several factors such as milk treatment (pasteurization), use of starter cultures, NaCl concentration, time, and temperature of ripening and preservation, pH, temperature, or post-ripening technological processes, which will be discussed in this chapter. PMID:22783233

  2. Technological factors affecting biogenic amine content in foods: a review

    Directory of Open Access Journals (Sweden)

    Fausto Gardini

    2016-08-01

    Full Text Available Biogenic amines (BAs are molecules which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine and agmatine. The importance of preventing the excessive accumulation of BAs in food is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BA accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting biogenic amine content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity and other BAs, environmental factors influencing BA formation (temperature, salt concentration, pH. In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolising BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances are addressed.

  3. Hepatiques du Surinam

    NARCIS (Netherlands)

    Jovet-Ast, S.

    1957-01-01

    Il n’existe pas, actuellement, de catalogue des Hépatiques du Surinam. Les Hépatiques de ce pays restent très peu connues. Cependant, certaines ont attiré l’attention des Bryologues et ont été citées dans quelques ouvrages anciens ou récents. Je ne ferai pas ici une révision complète de ces

  4. (l.) Medik du Maroc

    African Journals Online (AJOL)

    PR BOKO

    Résumé. Dipcadi serotinum (L.) Medik, est une plante de la famille des Hyacinthaceae, elle est largement utilisée comme réchauffant et aussi pour combattre la jaunisse. Cette plante trouve une large utilisation par la population de la région côtière du Maroc. À notre connaissance l'huile essentielle de cette espèce n'a ...

  5. Amines in the Earth’s Atmosphere: A Density Functional Theory Study of the Thermochemistry of Pre-Nucleation Clusters

    Directory of Open Access Journals (Sweden)

    Jason Herb

    2011-02-01

    Full Text Available The impact of organic species which are present in the Earth’s atmosphere on the burst of new particles is critically important for the understanding of the molecular nature of atmospheric nucleation phenomena. Amines have recently been proposed as possible stabilizers of binary pre-nucleation clusters. In order to advance the understanding of atmospheric nucleation phenomena, a quantum-chemical study of hydrogen-bonded complexes of binary sulfuric acid-water clusters with methyl-, dimethyl- and trimethylamines representing common atmospheric organic species, vegetation products and laboratory impurities has been carried out. The thermochemical stability of the sulfuric acid-amines-water complexes was found to be higher than that of the sulfuric acid-ammonia-water complexes, in qualitative agreement with the previous studies. However, the enhancement in stability due to amines appears to not be large enough to overcome the difference in typical atmospheric concentrations of ammonia and amines. Further research is needed in order to address the existing uncertainties and to reach a final conclusion about the importance of amines for the atmospheric nucleation.

  6. La mesure du danger

    CERN Document Server

    Manceron, Vanessa; Revet, Sandrine

    2014-01-01

    La mesure du danger permet d’explorer des dangers de nature aussi diverse que la délinquance, la pollution, l’écueil maritime, la maladie ou l’attaque sorcellaire, l’extinction d’espèces animales ou végétales, voire de la Planète tout entière. Au croisement de la sociologie, de l’anthropologie et de l’histoire, les différents articles analysent les pratiques concrètes de mesure pour tenter de comprendre ce qui se produit au cours de l’opération d’évaluation du danger sans préjuger de la nature de celui-ci. L’anthropologie a contribué à la réflexion sur l’infortune en s’intéressant aux temporalités de l’après : maladies, catastrophes, pandémies, etc. et en cherchant à rendre compte de l’expérience des victimes, de leur vie ordinaire bouleversée, de la recomposition du quotidien. Elle s’intéresse aussi aux autres types de mesures, les savoirs incorporés, qui reposent sur l’odorat, la vue ou le toucher et ceux qui ressortent d’une épistémologie « non ...

  7. Reductive amination with zinc powder in aqueous media

    Directory of Open Access Journals (Sweden)

    Giovanni B. Giovenzana

    2011-08-01

    Full Text Available Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

  8. Direct electrochemical imidation of aliphatic amines via anodic oxidation.

    Science.gov (United States)

    Zhang, Li; Su, Ji-Hu; Wang, Sujing; Wan, Changfeng; Zha, Zhenggen; Du, Jiangfeng; Wang, Zhiyong

    2011-05-21

    Direct electrochemical synthesis of sulfonyl amidines from aliphatic amines and sulfonyl azides was realized with good to excellent yields. Traditional tertiary amine substrates were broadened to secondary and primary amines. The reaction intermediates were observed and a reaction mechanism was proposed and discussed. © The Royal Society of Chemistry 2011

  9. Lactoperoxidase, an Antimicrobial Milk Protein, as a Potential Activator of Carcinogenic Heterocyclic Amines in Breast Cancer.

    Science.gov (United States)

    Sheikh, Ishfaq Ahmad; Jiffri, Essam Hussain; Kamal, Mohammad Amjad; Ashraf, Ghulam Md; Beg, Mohd Amin

    2017-11-01

    Lactoperoxidase (LPO) is an antimicrobial protein secreted from mammary, salivary and other mucosal glands. It is an important member of heme peroxidase enzymes and the primary peroxidase enzyme present in breast tissues. In addition to the antimicrobial properties, LPO has been shown to be associated with breast cancer etiology. Heterocyclic amines, an important class of environmental and dietary carcinogens, have been increasingly associated with breast cancer etiology. Heterocyclic amines undergo activation in breast tissue as a result of oxidation by LPO. The current study includes three important heterocyclic amines, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methy-6-phenylimidazo[4,5-b]-pyridine (PhIP), that have carcinogenic activity. The structural binding characterization of IQ, MeIQx and PhIP with LPO was done using in silico approaches. Their binding pattern and interactions with LPO amino acid residues were analyzed. The three compounds bound in the distal heme cavity of LPO without replacing the important water molecule required for oxidation of substrate compounds. PhIP displayed lesser binding affinity for LPO in comparison to IQ and MeIQx. The binding mode of heterocyclic amines in distal heme cavity of LPO resembled to that of substrate binding pattern. The three heterocyclic amines are suggested to act as LPO substrate. The undisturbed water molecule present in distal heme cavity of the LPO is expected to facilitate the oxidation and activation of the three heterocyclic amines. These activated compounds may potentially bind with DNA in breast tissues forming DNA adducts and may subsequently lead to breast cancer initiation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  10. The Synthesis of Methyl Salicylate: Amine Diazotization.

    Science.gov (United States)

    Zanger, Murray; McKee, James R.

    1988-01-01

    Notes that this experiment takes safety and noncarcinogenic reactants into account. Demonstrates the use of diazonium salts for the replacement of an aromatic amine group by a phenolic hydroxyl. Involves two pleasant-smelling organic compounds, methyl anthranilate (grape) and methyl salicylate (oil of wintergreen). (MVL)

  11. Microbiological, physicochemical properties and biogenic amine ...

    African Journals Online (AJOL)

    Thirty three strained yoghurt samples were collected from local open markets in different provinces of Turkey (Afyon [AF], Aydın [AY], Burdur [B], Isparta [I] and Muğla [M]). Physicochemical and microbiological properties, as well as biogenic amine content, were examined in each of the samples. The dry matter (17.90 to ...

  12. Direct amination of secondary alcohols using Ammonia

    NARCIS (Netherlands)

    Pingen, D.L.L.; Müller, C.; Vogt, D.

    2010-01-01

    Hydrogen shuttle: For the first time secondary alcohols and ammonia can be directly converted into primary amines with a selectivity of up to 99¿% by using a simple ruthenium/phosphine catalyst (see scheme; R1, R2= alkyl, aryl, alkenyl; M=[Ru3(CO)12]; and L=phosphine ligand).

  13. Direct Amination of alpha-Hydroxy Amides

    NARCIS (Netherlands)

    Chandgude, Ajay L.; Dömling, Alexander

    A TiCl4-mediated reaction for the direct amination of alpha-hydroxy amides has been developed. This simple, general, additive/base/ligand-free reaction is mediated by economical TiCl4. The reaction runs under mild conditions. This highly efficient C-N bond formation protocol is valid for diverse

  14. Influence of phosphates when uranium in solutions obtained by attacking Forez with sulfuric acid is precipitated by the action of lime; Influence des phosphates, lors de la precipitation par la chaux, de l'uranium contenu dans les solutions d'attaque sulfurique du Forez

    Energy Technology Data Exchange (ETDEWEB)

    Brebec, G

    1959-03-01

    Influence of phosphates when uranium in solutions obtained by attacking Forez with sulfuric acid is precipitated by the action of lime was studied. Most of the phosphates were eliminated in the form of ferric phosphates without noticeable losses of uranium: for this it is only necessary to add sufficient ferric sulfate to the solution to be treated so that [Po{sub 4}{sup 3-}]/[Fe{sup 3+}] {approx} 0,4. In these conditions, the preparation of a calcium concentrate rich in uranium takes place in two stages. The first is neutralization at pH 2,7 to 2,8 with elimination of phosphates, sulfates and iron; the second is precipitation of the concentrate at pH 6,5. (author) [French] Nous avons reussi a eliminer la majeure partie des phosphates sous forme de phosphates ferriques, sans pertes sensibles d'uranium. Pour cela, il suffit d'ajouter a la solution a traiter, du sulfate ferrique en quantite telle que: (Po{sub 4}{sup 3-}]/[Fe{sup 3+}] {approx} 0,4. Dans ces conditions, la preparation du concentre calcique, riche en uranium, s'effectue normalement en deux temps: 1) preneutralisation a pH 2,7-2,8: elimination des sulfates, phosphates et fer; 2) precipitation du concentre a pH 6,5. (auteur)

  15. Teneurs en acides gras polyinsaturés essentiels du lait maternel en France : évolution du contenu en acides linoléique et alphalinolénique au cours des 10 dernières années

    Directory of Open Access Journals (Sweden)

    Boué-Vaysse Carole

    2009-01-01

    Full Text Available Background: Long-chain polyunsaturated fatty acids (LC-PUFA are nutritionally important constituents of breast milk to support normal growth, immune function and central nervous system development of newborn infants. Both linoleic acid (18:2 n-6; LA and alpha-linolenic acid (18:3 n-3; ALA, the essential fatty acids, precursors of n-6 and n-3 LC-PUFA, are also present in breast milk. Although the total amount of fat in human milk is fairly constant, the fatty acid composition can vary substantially depending on the diet of the mother. Large variations in the LA, ALA and DHA (22:6 n-3 contents are observed among countries. As reported by previous studies (1993-2001, the ALA consumption of the French population was 2-3 times lower than the recommended value. Since this period, the food industry offers more food products enriched in n-3 fatty acids. Objective: The present study aimed to investigate whether current recommendations and improved n-3 PUFA content of food products comply with the actual breast-milk PUFA composition. For this purpose, the PUFA content of a large number of human milk samples collected in 2007 in different French regions were compared with previous data obtained in studies conducted in the nineties years (1993-1998. Moreover, this study aimed to confirm expected reduction of the trans fatty acid (TFA intake resulting from decreased level of TFA in margarine and other dietary fats during the same period. Study design and methods: Mature (postpartum day ≥ 30 human milk samples (n = 145 were provided in 2007 by eight French regional human milk banks (Bordeaux : n = 20; Dijon: n = 21; Ile-de-France: n = 18; Lyon: n = 20; Montpellier: n = 18; Nantes: n = 21; St Etienne: n = 6; Tours: n = 21, from healthy women volunteers with no particular health history. The fatty acid composition of breast milk was analysed by high-resolution gas-liquid chromatography. Statistical analysis was performed with Kruskall Wallis and Mann and

  16. Development and validation of an LC-MS/MS method for the determination of biogenic amines in wines and beers.

    Science.gov (United States)

    Nalazek-Rudnicka, Katarzyna; Wasik, Andrzej

    2017-01-01

    Biogenic amines are group of organic, basic, nitrogenous compounds that naturally occur in plant, microorganism, and animal organisms. Biogenic amines are mainly produced through decarboxylation of amino acids. They are formed during manufacturing of some kind of food and beverages such as cheese, wine, or beer. Histamine, cadaverine, agmatine, tyramine, putrescine, and β -phenylethylamine are the most common biogenic amines found in wines and beers. This group of compounds can be toxic at high concentrations; therefore, their control is very important. Analysis of biogenic amines in alcoholic drinks (beers and wines) was carried out by HPLC-MS/MS after their derivatization with p -toluenesulfonyl chloride (tosyl chloride). The developed method has been applied for analysis of seventeen biogenic amines in twenty-eight samples of lager beers and in twelve samples of different homemade wines (white grape, red grape, strawberry, chokeberry, black currant, plum, apple, raspberry, and quince). The developed method is sensitive and repeatable for majority of the analytes. It is versatile and can be used for the determination of biogenic amines in various alcoholic beverages.

  17. Halide salts and their structural properties in presence of secondary amine based molecule: A combined experimental and theoretical analysis

    Science.gov (United States)

    Ghosh, Pritam; Hazra, Abhijit; Ghosh, Meenakshi; Chandra Murmu, Naresh; Banerjee, Priyabrata

    2018-04-01

    Biologically relevant halide salts and its solution state structural properties are always been significant. In general, exposure of halide salts into polar solution medium results in solvation which in turn separates the cationic and anionic part of the salt. However, the conventional behaviour of salts might alter in presence of any secondary amine based compound, i.e.; moderately strong Lewis acid. In its consequence, to investigate the effect of secondary amine based compound in the salt solution, novel (E)-2-(4-bromobenzylidene)-1-(perfluorophenyl) hydrazine has been synthesized and used as secondary amine source. The secondary amine compound interestingly shows a drastic color change upon exposure to fluoride salts owing to hydrogen bonding interaction. Several experimental methods, e.g.; SCXRD, UV-Vis, FT-IR, ESI-MS and DLS together with modern DFT (i.e.; DFT-D3) have been performed to explore the structural properties of the halide salts upon exposure to secondary amine based compound. The effect of counter cation of the fluoride salt in binding with secondary amine source has also been investigated.

  18. Influence on wine biogenic amine composition of modifications to soil N availability and grapevine N by cover crops.

    Science.gov (United States)

    Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; Cabrita, Maria João; García-Escudero, Enrique; Peregrina, Fernando

    2017-11-01

    Vineyard soil management can modify the nitrogen soil availability and, therefore, grape amino acid content. These compounds are precursors of biogenic amines, which have negative effects on wine quality and human health. The objective was to study whether the effect of conventional tillage and two cover crops (barley and clover) on grapevine nitrogen status could be related to wine biogenic amines. Over 4 years, soil NO 3 - -N, nitrogen content in leaf and wine biogenic amine concentration were determined. Barley reduced soil NO 3 - -N availability and clover increased it. In 2011, at bloom, nitrogen content decreased with barley treatment in both blade and petiole. In 2012, nitrogen content in both leaf tissues at bloom was greater with clover than with tillage and barley treatments. Also, total biogenic amines decreased in barley with respect to tillage and clover treatments. There were correlations between some individual and total biogenic amine concentrations with respect to nitrogen content in leaf tissues. Wine biogenic amine concentration can be affected by the grapevine nitrogen status, provoked by changes in the soil NO 3 - -N availability with both cover crop treatments. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. Contribution to the study of the redox couple Np(VI)/Np(V) in the presence of uranium(VI) in solutions of nitric acid and nitrous acid; Contribution a l'etude du comportement redox du couple Np(VI)/Np(V) en presence d'uranium VI dans les solutions constituees d'acide nitrique et d'acide nitreux

    Energy Technology Data Exchange (ETDEWEB)

    Arpigny, S. [CEA Marcoule, Dept. de Radiochimie et Procedes, DRP, 30 (France)

    2001-07-01

    The redox behavior of the Np(VI)/Np(V) couple was the subject of a spectrometric study of the Np(VI) reduction reaction in nitric acid solutions (4 to 5 M) containing variable concentrations (1.5 to 3.5 x 10{sup -3} M) of nitrous acid. A low nitrous acid concentration and a high nitric acid concentration were found to favor the stabilization of Np(VI). The stoichiometric coefficients of nitrous acid and nitric acid in the Np(VI) reduction reaction were determined thermodynamically, although only the reaction order with respect to HNO{sub 2} could be calculated from a kinetic analysis. Adding nitrate ions to a HNO{sub 3}/HNO{sub 2} solution enhanced the stability of neptunium at oxidation state +VI, but also increased the reduction rate. When uranium(VI) was added to the HNO{sub 3}/HNO{sub 2} solutions, the total quantity of neptunium at oxidation state +V (either free or as a Np(V)-U(VI) complex) remained practically unchanged, as did the Np(VI) reduction rate. The electrochemical behavior of the Np(VI)/Np(V) couple was investigated in a weak acidic medium by voltammetry with an ultra-micro-electrode (UME). The oxidation wave limiting current variation was a linear function of the Np(V) concentration when a gold UME was used, but not with a platinum UME; the reduction wave limiting current variation versus the Np(V) concentration was linear with either gold or platinum UMEs. The presence of the Np(V)-U(VI) complex in the neptunium solutions was characterized by a shift in the normal apparent potential of the Np(VI)/Np(V) couple toward anodic potentials consistent with the previously determined values of the complexation constants. (author)

  20. Intolerance to dietary biogenic amines: a review.

    Science.gov (United States)

    Jansen, Sophia C; van Dusseldorp, Marijke; Bottema, Kathelijne C; Dubois, Anthony E J

    2003-09-01

    To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature. Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive. A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache. The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

  1. Reactive extraction of lactic acid using alamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2002-01-01

    Lactic acid is an important commercial product and extracting it out of aqueous solution is a growing requirement in fermentation based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent)

  2. Preparation and reactivity studies of maleimidophenyl glycidylether with amines

    Directory of Open Access Journals (Sweden)

    B. Lakshmi

    2011-04-01

    Full Text Available The hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl glycidylether (N-MPGE was prepared by reacting N-(4-hydroxyphenyl maleimide (HPM with epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possessed both the oxirane ring and maleimide group. The curing reaction of N-MPGE with amines as curing agents such as tetraethylenepentamine (TEPA, bishexamethylenetriamine (BHMT, 2-methyl pentamethylenediamine (2-MPMDA and 2,2,4-trimethy diamines (2,2,4-TMDA was studied. The cured samples exhibited good thermal stability and excellent chemical (acid/alkali/solvent and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity network of the cured systems.

  3. Recyclable surfaces for amine conjugation chemistry via redox reaction

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Inseong; Yeo, Woon Seok [Dept. of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul (Korea, Republic of); Bae, Se Won [Green Materials and Process Group, Research Institute of Sustainable Manufacturing System, Korea Institute of Industrial Technology, Cheonan (Korea, Republic of)

    2017-02-15

    In this study, we extended this strategy to present a switchable surface that allows surface functionalization and removal of functional groups repeatedly. The substrate presenting a benzoquinone acid group is first used to immobilize with an amine-containing (bio)molecule using well-known conjugation chemistry. The benzoquinone group is then converted to the corresponding hydroquinone by treating with a reducing agent. We have described a strategy for the dynamic control of surface properties with recyclability via a simple reduction/ oxidation reaction. A stimuli-responsive quinone derivative was harnessed for the repeated immobilization and release of (bio)molecules, and thus, for the repeated dynamic change of the surface properties according to the characteristics of the immobilized (bio)molecules.

  4. Treatment of acidic mine waters from the Solbec-Cupra site using the Mediaflex{trademark} process; Traitement des eaux minieres acides du site Solbec-Cupra par le procede Mediaflex{sub TM}

    Energy Technology Data Exchange (ETDEWEB)

    Belanger, M -C; Ross, A; Shoiry, J [Valoraction Inc., Sherbrooke, PQ (Canada)

    1995-01-01

    Applications and development of Mediaflex{trademark} filter treatment technology are described. The method combines physical, chemical, and biological processes into a technology suitable for purification of sanitary landfill leachates, septic tank sludge, and acidic mine waters. More than a dozen of the patented filters are in use. The treatment can reach 99.9% removal of heavy metals and phenolic compounds present in waste water. Since installation of the Mediaflex{sub TM} filter at the Cambior Solbec-Cupra mining site more than 50,000 cubic metres of acidic mine waste waters (pH 5.5) have been treated. After Mediaflex{sub TM} filtration, the pH is approximately 8.0, with the heavy metal content reduced substantially. 3 refs., 4 figs., 3 tabs.

  5. Acid lixiviation of a contaminated earth with the view to the dimensioning of an electro-remediation process; Lixiviation acide d'une terre contaminee en vue du dimensionnement d'un procede d'electroremediation

    Energy Technology Data Exchange (ETDEWEB)

    Palaprat, S; Fernandez, A [Ecole des Mines d' Albi-Carnaux, Centre Energetique-Environnement, Lab. du Genie des Procedes des Solides Divises, 83 - Albi (France); Sardin, M [Centre National de la Recherche Scientifique (CNRS-ENSIC), Lab. des Sciences du Genie Chimique, 54 - Nancy (France)

    2001-07-01

    Electro-remediation is a process developed for the treatment of polluted earths and which uses a direct current for the extraction of the pollutants in solution. When this process is applied to a multi-metal system, preliminary physico-chemical studies are necessary to determine the reaction mechanisms responsible for the solubilization of the pollutants. In this work, dynamic experiments are performed with a laboratory column and sulfuric acid is used to change the acidification of the earth. (J.S.)

  6. Catalytic N{sub 2}O decomposition in a model tail gas from nitric acid plants; Decomposition catalytique du protoxyde d'azote dans un modele de gaz de queue produits par un atelier d'acide nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Mul, G.; Xu, X.; Perez Ramirez, J.; Vaccaro, A.R.; Kapteijn, F.; Moulijn, J.A. [Delft University of Technology, Faculty of Chemical Technology and Materials Sciences, Delft (Netherlands)

    2001-07-01

    In this study direct catalytic decomposition of N{sub 2}O in simulated tail-gas from nitric acid plants, containing water, oxygen, NO{sub x}, was investigated. Three groups of catalysts were prepared: oxide-supported catalysts; zeolite-based catalysts; mixed oxides derived from hydrotalcites-like (HTLc) materials. The activity of these types of catalysts was tested in an advanced automated six-flow reactor system. Nobel metal (Ru, Rh) based catalysts, either supported on zeolites or ex-hydrotalcite compositions (Mg-Al or Co-Al mixed oxides), and Fe-ZSM-5 effectively decompose N{sub 2}O in tail-gas conditions at temperatures of about 400-450 deg C, typical for certain nitric acid plants. Catalysts active for tail gas temperatures of 230-250 deg C, typical for other nitric acid plants, were not found. This is mainly due to the dramatic negative effect of especially water and NO{sub x} on the conversion of N{sub 2}O. The negative effect of NO{sub x} observed for many catalysts might be related to the formation of surface nitrites and nitrates, blocking active sites for N{sub 2}O decomposition in the 200-300 deg C temperature range. (authors)

  7. Intensification of conversion of glucose to lactic acid : equilibria and kinetics for back extraction of lactic acid using trimethylamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, A. Bert M.; Versteeg, Geert F.; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  8. Intensification of conversion of glucose to lactic acid: equilibria and kinetics for back extraction of lactic acid using trimethylamine

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2004-01-01

    Alamine 336 is an effective extractant for the recovery of lactic acid from aqueous solutions. An approach for regeneration and product recovery from such extracts is to back extract lactic acid with a water soluble, volatile tertiary amine such as trimethyl amine. Equilibrium data are presented

  9. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    Directory of Open Access Journals (Sweden)

    H. Herrmann

    2009-12-01

    Full Text Available Monomethylamine (MA, dimethylamine (DMA and diethylamine (DEA were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0–30 pg m−3 for MA, 130–360 pg m−3 for DMA and 5–110 pg m−3 for DEA during the spring bloom in May 2007 and 2–520 pg m−3 for MA, 100–1400 pg m−3 for DMA and 90–760 pg m−3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14–0.42 μm indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC content ranged from 0.2–2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N–1.5% N in the sum of nitrate, ammonium and amines. This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

  10. Archives: les cahiers du cread

    African Journals Online (AJOL)

    Items 1 - 24 of 24 ... Archives: les cahiers du cread. Journal Home > Archives: les cahiers du cread. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 24 of 24 Items. 2016 ...

  11. Le commerce du Nord

    OpenAIRE

    Pourchasse, Pierrick; Bouëdec, Gérard Le

    2015-01-01

    Au XVIIIe siècle, la France s'approvisionne abondamment dans les pays du Nord : bois, chanvre et goudron de la Baltique, tonnellerie de Poméranie, pêche de rogue de Norvège, graines de lin de Courlande, barres de fer suédois… Sa balance commerciale est pourtant positive grâce aux sels, aux vins et surtout des nouvelles marchandises coloniales. Or, la plupart des transactions passent par l’incontournable intermédiaire hollandais. Les explications sur l’absence des Français dans le Nord sont re...

  12. La voie du Centre

    OpenAIRE

    2017-01-01

    Après avoir quelque peu louvoyé dans un discours apparemment anarchique où les souvenirs semblent se bousculer sans autre fil conducteur que la référence obsédante au mal satanique, brusquement le narrateur annonce un événement primordial : Foi um fato que se deu, um dia, se abriu. O primeiro. Depois o senhor verá por quê, me devolvendo minha razão (79). Cette introduction situe la rencontre du Menino comme fondatrice d’un destin dont il reviendrait au narrataire de dégager les enchaînements....

  13. Bulletin du CRDI #126

    International Development Research Centre (IDRC) Digital Library (Canada)

    26 févr. 2018 ... Dans ce numéro, découvrez comment la recherche financée par le CRDI permet d'améliorer la santé des mères et des enfants dans les pays du Sud et comment les innovations techniques et sociales de l'initiative SEARCH permettent de surmonter les défis liés à la cybersanté. N'oubliez pas non plus de ...

  14. Metabolism and Biomarkers of Heterocyclic Aromatic Amines in Molecular Epidemiology Studies: Lessons Learned from Aromatic Amines

    Science.gov (United States)

    2011-01-01

    Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group, to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs and, thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review article, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and

  15. Amine functionalization of carbon nanotubes for the preparation of CNT based polyactide composites - A comparative study

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2011-11-01

    Full Text Available . They are proven to have unique electronic, mechanical, and physical properties.1,2 However, the limited solubility of CNTs in most organic solvents limits their chemical manipulation, quantitative characterization, and wide application. In recent years... (SWCNTs) can be solubilized in common organic solvents by noncovalent (ionic) functionalization of the carboxylic acid groups by using octadecyl amine (ODA). They found that the same dissolution process applied to arc-produced MWCNTs, average length < 1...

  16. Improved behavior of cooper-amine complexes during thermal annealing for conductive thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ayag, Kevin Ray; Panama, Gustavo; Paul, Shrabani; Kim, Hong Doo [Dept. of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin (Korea, Republic of)

    2017-02-15

    Previous studies successfully produced conductive thin films from organo-metallic-compounds-based inks. Some inks like those made from copper salt and amines, however, tend to move during thermal annealing and, thus, affect the conductive pattern on the substrate. In this study, conductive inks were synthesized by forming complexes of copper with amines and/or blended amines. To build-up an organo-metallic framework and preserve the pattern throughout the annealing period, diamine was added to the complex in different proportions. The prepared inks were coated on glass substrate and were annealed on a hot plate at 170°C under the gaseous mixture of formic acid and alcohol for 5 min. The metallic film was observed to retain the original pattern of the ink during and after annealing. Adhesion on the substrate was also improved. Inks with blended amines produced films with lower resistivities. The lowest electrical resistivity recorded was 4.99 μΩ cm, three times that of bulk copper.

  17. Deuterium exchange between hydrofluorocarbons and amines

    International Nuclear Information System (INIS)

    Hammond, W.B.; Bigeleisen, J.; Tuccio, S.A.

    1983-01-01

    The invention consists of a process for obtaining a compound enriched in deuterium which comprises the known method of exposing a gaseous hydrofluorocarbon to infrared laser radiation of a predetermined frequency to selectively cause a chemical reaction involving hydrofluorocarbon molecules containing deuterium without substantially affecting hydrofluorocarbon molecules not containing deuterium, thereby producing, as reaction products, a compound enriched in deuterium and hydrofluorocarbon depleted in deuterium; combined with a new method, which comprises enriching the deuterium content of the depleted hydrofluorocarbon by contacting the depleted hydrofluorocarbon with an alkali metal amide and an amine having a concentration of deuterium at least that which will yield an increase in deuterium concentration of the hydrofluorocarbon upon equilibration, whereby the amine becomes depleted in deuterium

  18. Amine chemistry. Update on impact on resin

    International Nuclear Information System (INIS)

    Bachman, Gregory; Kellogg, Douglas; Wilkes, Marty

    2012-01-01

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  19. Amine chemistry. Update on impact on resin

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gregory; Kellogg, Douglas [Siemens Industry, Inc., Rockford, IL (United States). Technology and Lab Services; Wilkes, Marty [Siemens Industry, Inc., Rockford, IL (United States). Water Technologies Div.

    2012-03-15

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  20. Ruthenium-Catalyzed Aerobic Oxidation of Amines.

    Science.gov (United States)

    Ray, Ritwika; Hazari, Arijit Singha; Lahiri, Goutam Kumar; Maiti, Debabrata

    2018-01-18

    Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Choeur du CERN : Concert

    CERN Multimedia

    CERN Choir

    2017-01-01

    Une œuvre à découvrir! La grande Missa pro defunctis de François-Joseph Gossec (1734-1829) est le chef-d’œuvre tôt venu (à vingt-cinq ans) d’un compositeur qui vivra encore 70 ans après sa création. Elle a connu la gloire, puis s’est fait un peu oublier. Pas du tout le monde cependant : des musicologues ont montré ce que le Requiem de Mozart lui devait ; et il suffit de l’avoir entendue pour comprendre pourquoi Berlioz (qui avait vingt-six ans à la mort de Gossec) en a été impressionné : les nombreux cuivres et bois répartis dans des endroits plus ou moins cachés de la salle de concert pour exprimer les frayeurs du Jugement dernier annoncent son Requiem – et celui de Verdi. Mais « plus encore que par...

  2. Les risques du travail

    CERN Document Server

    Thébaud-Mony, Annie

    2015-01-01

    Depuis les années 1990, les conditions de travail se sont peu à peu imposées dans le débat social. Néanmoins, la situation reste critique. Les risques traditionnels n'ont pas disparu : les manutentions lourdes, l'exposition professionnelle aux cancérogènes, au bruit ou aux vibrations demeurent répandues... De plus, certaines " améliorations " n'ont fait que déplacer et dissimuler les problèmes, telle l'externalisation des risques grâce à la sous-traitance. Dans le même temps, les transformations du travail et des modalités de gestion de la main-d'œuvre ont fragilisé les collectifs et accru l'isolement des salariés, conduisant à une montée visible de la souffrance psychique. Face à ces évolutions, il est plus que jamais nécessaire que tous les acteurs concernés, en particulier les salariés eux-mêmes et leurs représentants, s'approprient les connaissances indispensables pour améliorer la protection de la santé sur les lieux du travail. Tel est le but de ce livre, qui renouvelle int�...

  3. Rate phenomena in uranium extraction by amines

    International Nuclear Information System (INIS)

    Coleman, C.F.; McDowell, W.J.

    1979-01-01

    Kinetics studies and other rate measurements are reviewed in the amine extraction of uranium and of some other related and associated metal ions. Equilibration is relatively fast in the uranium sulfate systems most important to uranium hydrometallurgy. Significantly slow equilibration has been encountered in some other systems. Most of the recorded rate information, both qualitative and quantitative, has come from exploratory and process-development work, while some kinetics studies have been directed specifically toward elucidation of extraction mechanisms. 71 references

  4. Ultrasonic promoted catalyst-free N-formylation of amines in neutral ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Vinod T. Kamble

    2017-05-01

    Full Text Available A catalyst-free, simple and efficient protocol for N-formylation of alkyl, aryl, and heteroaryl amines with formic acid under ultrasonic irradiation at room temperature using 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 as a neutral medium is described.

  5. Degradation of biogenetic amines by gamma radiation process and identification by GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Cardozo, Monique; Souza, Stefania P. de; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME, Instituto Militar de Engenharia, RJ (Brazil)

    2011-07-01

    Biogenic amines are low molecular weight organic bases with aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structures that can be found in several foods, in which they are mainly produced by microbial decarboxylation of amino acids. The reasons to control amines in food are their potential toxicity and their use like food quality markers. The consumption of food containing large amounts of biogenic amines can result in allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Biogenic amines are also known as possible precursors of carcinogens, such as N-nitrosamines. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth. However, control measures to reduce their levels once formed need to be also considered. The biogenic amines are frequently found in high concentrations and not reduced by high-temperature treatment, which makes difficult to use conventional methods of food preservation for this purpose. Food irradiation has been used in many countries for inhibition of sprouting, destruction of food borne insects, extension of shelf life or improvement of the technological of food. Irradiation is also known as a good method for inactivating pathogens and reducing microorganisms in food materials. Furthermore, besides the sanitary purpose, irradiation technology in new trials can be applied to induce radiolysis of toxic contaminants in food products reducing their content. This study has the objective to evaluate the effect of different gamma irradiation doses (1, 3 and 5kGy) in methanol solutions of three different biogenic amines: tryptamine, tyramine and b-phenylethylamine. The solutions were prepared using standard biogenic amines purchased from Sigma-Aldrich Brazil and methanol HPLC grade with a concentration of 100 {mu}g/mL. They were irradiated in Centro Tecnologico do Exercito

  6. Degradation of biogenetic amines by gamma radiation process and identification by GC/MS

    International Nuclear Information System (INIS)

    Cardozo, Monique; Souza, Stefania P. de; Lima, Keila dos S.C.; Lima, Antonio L. dos S.

    2011-01-01

    Biogenic amines are low molecular weight organic bases with aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structures that can be found in several foods, in which they are mainly produced by microbial decarboxylation of amino acids. The reasons to control amines in food are their potential toxicity and their use like food quality markers. The consumption of food containing large amounts of biogenic amines can result in allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Biogenic amines are also known as possible precursors of carcinogens, such as N-nitrosamines. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth. However, control measures to reduce their levels once formed need to be also considered. The biogenic amines are frequently found in high concentrations and not reduced by high-temperature treatment, which makes difficult to use conventional methods of food preservation for this purpose. Food irradiation has been used in many countries for inhibition of sprouting, destruction of food borne insects, extension of shelf life or improvement of the technological of food. Irradiation is also known as a good method for inactivating pathogens and reducing microorganisms in food materials. Furthermore, besides the sanitary purpose, irradiation technology in new trials can be applied to induce radiolysis of toxic contaminants in food products reducing their content. This study has the objective to evaluate the effect of different gamma irradiation doses (1, 3 and 5kGy) in methanol solutions of three different biogenic amines: tryptamine, tyramine and b-phenylethylamine. The solutions were prepared using standard biogenic amines purchased from Sigma-Aldrich Brazil and methanol HPLC grade with a concentration of 100 μg/mL. They were irradiated in Centro Tecnologico do Exercito

  7. Jouer du piano

    Directory of Open Access Journals (Sweden)

    Fériel Kaddour

    2011-04-01

    Full Text Available La réflexion s’appuie dans un premier temps sur une opposition entre deux attitudes de pianistes  à l’égard du travail à l’instrument : Gould, qui revendique une séparation d’avec le clavier pour ne privilégier que la lecture; Arrau, dont la technique au contraire vise à « faire corps » avec son piano. L’étude de ces deux démarches d’interprètes conduit à une conclusion croisée : l’abstraction gouldienne n’est rien d’autre qu’un déplacement du jeu vers d’autres instruments (ceux qui servent à la prise de son et au montage de ses enregistrements ; le « faire-corps » hérité de la culture pianistique romantique est plus dialectique que fusionnel, et en cela implique une capacité de mise à distance. A partir de cette double conclusion, on tâche enfin de repenser la place du jeu à l’instrument dans la mise en œuvre d’une interprétation, en interrogeant le dialogue qui s’instaure entre la partition telle qu’elle s’écrit et le geste tel qu’il se joue.Our study leans on an opposition between two pianists' attitudes about their work with the instrument. Gould claims a necessary separation from the keyboard in order to prioritize reading. Arrau, on the contrary, relies on a technique which consists in “being one” with his piano. The analysis of these two interprets’ behaviours leads to a crossed conclusion: the gouldian abstraction is nothing else than a displacement of the playing towards another kind of instruments, the ones he uses in sound recording and cut up; Arrau’s “being one” is more dialectic than at first sight, and it therefore implies a real distancing from the piano. This constatation leads to rethink the place of the piano playing in the setting of an interpretation, and to highlight the real dialogue which develops itself between the score as it has been written and the gesture as it is played.

  8. Tertiary-amine-containing thermo- and pH-sensitive hydrophilic ABA triblock copolymers: effect of different tertiary amines on thermally induced sol-gel transitions.

    Science.gov (United States)

    Henn, Daniel M; Wright, Roger A E; Woodcock, Jeremiah W; Hu, Bin; Zhao, Bin

    2014-03-11

    This Article reports on the synthesis of a series of well-defined, tertiary-amine-containing ABA triblock copolymers, composed of a poly(ethylene oxide) (PEO) central block and thermo- and pH-sensitive outer blocks, and the study of the effect of different tertiary amines on thermally induced sol-gel transition temperatures (T(sol-gel)) of their 10 wt % aqueous solutions. The doubly responsive ABA triblock copolymers were prepared from a difunctional PEO macroinitiator by atom transfer radical polymerization of methoxydi(ethylene glycol) methacrylate and ethoxydi(ethylene glycol) methacrylate at a feed molar ratio of 30:70 with ∼5 mol % of either N,N-diethylaminoethyl methacrylate (DEAEMA), N,N-diisopropylaminoethyl methacrylate, or N,N-di(n-butyl)aminoethyl methacrylate. The chain lengths of thermosensitive outer blocks and the molar contents of tertiary amines were very similar for all copolymers. Using rheological measurements, we determined the pH dependences of T(sol-gel) of 10 wt % aqueous solutions of these copolymers in a phosphate buffer. The T(sol-gel) versus pH curves of all polymers exhibited a sigmoidal shape. The T(sol-gel) increased with decreasing pH; the changes were small on both high and low pH sides. At a specific pH, the T(sol-gel) decreased with increasing the hydrophobicity of the tertiary amine, and upon decreasing pH the onset pH value for the T(sol-gel) to begin to increase noticeably was lower for the more hydrophobic tertiary amine-containing copolymer. In addition, we studied the effect of different tertiary amines on the release behavior of FITC-dextran from 10 wt % micellar gels in an acidic medium at 37 and 27 °C. The release profiles for three studied hydrogels at 37 °C were essentially the same, suggesting that the release was dominated by the diffusion of FITC-dextran. At 27 °C, the release was significantly faster for the DEAEMA-containing copolymer, indicating that both diffusion and gel dissolution contributed to the

  9. Coalescence of organic solutions in acid and metal extraction by tri-alkylamines; Demixtion des solutions organiques lors de l'extraction des acides et des metaux par les trialcoylamines

    Energy Technology Data Exchange (ETDEWEB)

    Blain, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1970-07-01

    The formation of two layers with tri-alkylammonium salts solutions in low polarity diluents could be explained on the basis of settling of micelles. Light scattering and viscosity measurements reveal that micelles size increases rather sharply before coalescence. The existence of micelles in the solution has been confirmed by ultracentrifuge experiments. The behaviour of these solutions, in general, is similar to that of colloidal soap solutions. The various parameters which promote third phase formation are: anion size in the order of Cl{sup -} {approx} Br{sup -} < NO{sub 3} < ClO{sub 4}{sup -}; extraction of excess acid; metal cation size in the order of UO{sub 2}{sup ++} < Pu{sup 4+} {approx} Th{sup 4+}; decreasing in the length of the n-alkyl chain in the alkyl-ammonium salts; decreasing in diluent polarity. The above phenomenon could be explained on the basis of the affinity between alkylammonium salts and organic solvent. The composition of the three phases is independent of the initial amine concentration for a fixed acid and metal concentration. This has been verified experimentally and is in conformity with phase rule. (author) [French] La demixtion des solutions organiques de sels de trialcoyl-ammonium dans les solvants peu polaires est provoquee par la decantation des micelles presentes dans la solution. Nous avons montre par viscosimetrie et surtout par diffusion de la lumiere que les micelles grossissent de facon importante juste avant demixtion. Des experiences d'ultracentrifugation nous ont permis de confirmer la presence de micelles. Le comportement de ces solutions est analogue a celui des solutions colloidales de savons dans l'eau. Ainsi tous les parametres qui font decroitre la compatibilite du sel d'ammonium R{sub 3}NH+ oooX{sup -} avec le solvant organique favorisent l'agregation du sel et par consequent la demixtion, soient: l'extraction des anions de taille croissante Cl{sup -} {approx} Br{sup -} < NO{sub 3} < ClO{sub 4}{sup -}; l

  10. Amine promoted, metal enhanced degradation of Mirex under high temperature conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jallad, Karim N. [American University of Sharjah, Department of Chemistry, P.O. Box 26666, Sharjah (United Arab Emirates)]. E-mail: kjallad@runbox.com; Lynn, Bert C. [University of Kentucky, Department of Chemistry, Lexington, KY 40506-055 (United States); Alley, Earl G. [Mississippi State University, Department of Chemistry, MS State, MS 39762 (United States)

    2006-07-31

    In this study, zero-valent metal dehalogenation of mirex was conducted with amine solvents at high temperatures. Mirex was treated with excess amine in sealed glass tube reactors under nitrogen. The amines used were n-butyl amine (l), ethyl amine (l), dimethyl amine (g), diethyl amine (l), triethyl amine (l), trimethyl amine (g) and ammonia (g). The metals used were copper, zinc, magnesium, aluminum and calcium. The most suitable amine solvent and metal were selected by running a series of reactions with different amines and different zero-valent metals, in order to optimize the conditions under which complete degradation of mirex takes place. These dehalogenation reactions illustrated the role of zero-valent metals as reductants, whereas the amine solvents acted as proton donors. In this study, we report that mirex was completely degraded with diethyl amine (l) in the presence of copper at 100 deg. C and the hydrogenated products accounted for more than 94 of the degraded mirex.

  11. Study of molybdenum (VI) complexation and precipitation by zirconium (IV) in strongly acid medium. Application to nuclear spent fuel dissolution; Etude de la complexation et de la precipitation du molybdene (VI) par le zirconium (IV) en milieu tres acide. Application a la dissolution du combustible nucleaire irradie

    Energy Technology Data Exchange (ETDEWEB)

    Esbelin, E

    1999-07-01

    These last years the formation of solid deposits has been observed in the dissolution workshops of the La Hague plant. A sample of the solid was withdrawn for expertise: molybdenum and zirconium are the two major components of the solid, identified as zirconium molybdate. This thesis consisted in the approach of the mechanisms in solution liable to induce precipitate formation. After a bibliographical overview on the chemistry of Mo(VI) in highly acidic solution, this system was studied by absorption spectrophotometry in perchloric medium. The implication of two major forms of Mo(VI) in a dimerization equilibrium was confirmed by this way and by {sup 95}Mo NMR. The principal parameters governing this equilibrium were identified. It is thus shown that the molybdenum dimerization reaction is exothermic. Disturbance of the Mo(VI) system in highly acidic solution by Zr(IV) was also studied. In a restricted experimental field, for which 'conventional' exploitation methodologies had to be adapted to the system, a main complex of stoichiometry 1:1 between Mo(VI) and Zr(IV) was found. The precipitation study of Mo(VI) by Zr(IV) under conditions close to those of the dissolution medium of nuclear spent fuel was undertaken. The main parameters which control precipitation kinetics were identified. The results obtained reveal that precipitation is controlled by a single macroscopic process and therefore can be described by a single equation. The solid obtained is composed of only one phase presenting a Mo:Zr non-stoichiometry when compared to the theoretical formula ZrMo{sub 2}O{sub 7}(OH){sub 2},2H{sub 2}O. At last, on the basis of the research results, a descriptive mechanism of the system is proposed in which intervenes a 1:1 intermediate complex, much more soluble than a probable 2:1 precipitation precursor. (author)

  12. Tandem catalytic allylic amination and [2,3]-Stevens rearrangement of tertiary amines.

    Science.gov (United States)

    Soheili, Arash; Tambar, Uttam K

    2011-08-24

    We have developed a catalytic allylic amination involving tertiary aminoesters and allylcarbonates, which is the first example of the use of tertiary amines as intermolecular nucleophiles in metal-catalyzed allylic substitution chemistry. This process is employed in a tandem ammonium ylide generation/[2,3]-rearrangement reaction, which formally represents a palladium-catalyzed Stevens rearrangement. Low catalyst loadings and mild reaction conditions are compatible with an unprecedented substrate scope for the ammonium ylide functionality, and products are generated in high yields and diastereoselectivities. Mechanistic studies suggested the reversible formation of an ammonium intermediate.

  13. Differential modulation of Beta-adrenergic receptor signaling by trace amine-associated receptor 1 agonists.

    Directory of Open Access Journals (Sweden)

    Gunnar Kleinau

    Full Text Available Trace amine-associated receptors (TAAR are rhodopsin-like G-protein-coupled receptors (GPCR. TAAR are involved in modulation of neuronal, cardiac and vascular functions and they are potentially linked with neurological disorders like schizophrenia and Parkinson's disease. Subtype TAAR1, the best characterized TAAR so far, is promiscuous for a wide set of ligands and is activated by trace amines tyramine (TYR, phenylethylamine (PEA, octopamine (OA, but also by thyronamines, dopamine, and psycho-active drugs. Unfortunately, effects of trace amines on signaling of the two homologous β-adrenergic receptors 1 (ADRB1 and 2 (ADRB2 have not been clarified yet in detail. We, therefore, tested TAAR1 agonists TYR, PEA and OA regarding their effects on ADRB1/2 signaling by co-stimulation studies. Surprisingly, trace amines TYR and PEA are partial allosteric antagonists at ADRB1/2, whereas OA is a partial orthosteric ADRB2-antagonist and ADRB1-agonist. To specify molecular reasons for TAAR1 ligand promiscuity and for observed differences in signaling effects on particular aminergic receptors we compared TAAR, tyramine (TAR octopamine (OAR, ADRB1/2 and dopamine receptors at the structural level. We found especially for TAAR1 that the remarkable ligand promiscuity is likely based on high amino acid similarity in the ligand-binding region compared with further aminergic receptors. On the other hand few TAAR specific properties in the ligand-binding site might determine differences in ligand-induced effects compared to ADRB1/2. Taken together, this study points to molecular details of TAAR1-ligand promiscuity and identified specific trace amines as allosteric or orthosteric ligands of particular β-adrenergic receptor subtypes.

  14. Tailoring Enzyme-Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress.

    Science.gov (United States)

    Liu, Ching-Ping; Wu, Te-Haw; Lin, Yu-Lung; Liu, Chia-Yeh; Wang, Sabrina; Lin, Shu-Yi

    2016-08-01

    The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase-like activity can decompose hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating-mediated enzyme-like activities. Herein, it is reported for the first time that amine-terminated PAMAM dendrimer-entrapped gold nanoclusters (AuNCs-NH2 ) unexpectedly lose their peroxidase-like activity while still retaining their catalase-like activity in physiological conditions. Surprisingly, the methylated form of AuNCs-NH2 (i.e., MAuNCs-N(+) R3 , where R = H or CH3 ) results in a dramatic recovery of the intrinsic peroxidase-like activity while blocking most primary and tertiary amines (1°- and 3°-amines) of dendrimers to form quaternary ammonium ions (4°-amines). However, the hidden peroxidase-like activity is also found in hydroxyl-terminated dendrimer-encapsulated AuNCs (AuNCs-OH, inside backbone with 3°-amines), indicating that 3°-amines are dominant in mediating the peroxidase-like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°-amines on the surface of dendrimer-encapsulated AuNCs provides sufficient suppression of the critical mediator •OH for the peroxidase-like activity. Finally, it is demonstrated that AuNCs-NH2 with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. La grammaticalisation du monde.

    Directory of Open Access Journals (Sweden)

    Etienne Pingaud

    2010-01-01

    Full Text Available Ouvrage atypique par le fond comme par la forme, Le devoir et la grâce rend compte du minutieux travail d’élaboration théorique auquel s’attelle Cyril Lemieux depuis plusieurs années. Et le résultat final se veut pour le moins ambitieux : l’auteur propose un système total supposé dépasser d’un même élan le relativisme, le mentalisme, l’universalisme ethnocentrique, l’historicisme, le naturalisme et l’herméneutisme, tout en réconciliant les sciences sociales avec le ...

  16. Le sacre du printemps

    Directory of Open Access Journals (Sweden)

    Denise Pumain

    2002-03-01

    Full Text Available Cybergeo aura six ans en avril : dans la réalité du virtuel, dans l'univers récent et fluctuant de la publication en ligne, cela fait de nous, tout à la fois, des pionniers et des vétérans. De façon plus surprenante, il se trouve que nous sommes aussi uniques : parmi toutes les revues électroniques de sciences sociales, aucune ne combine comme Cybergeo ancienneté, publication exclusivement électronique, liberté d'accès au texte intégral, édition et gestion par des chercheurs, et comité de lec...

  17. Le Brahmane du Komintern

    Directory of Open Access Journals (Sweden)

    Elizabeth Burgos

    2008-01-01

    Full Text Available Le Brahmane du Komintern, largometraje documental del realizador francés Vladimir León, constituye un ejercicio ejemplar de investigación histórica y  de lograda factura de realización. Y, pese a no haber contado con la ayuda de ninguno organismo público, se trata de un ambicioso proyecto que cubre una amplia extensión geográfica que abarca: Estados Unidos, México, Moscú, Berlín, y la India. Gira en torno a una figura que tuvo en su tiempo su hora de gloria. Un bengalí, hijo de braman, la c...

  18. (Sorghum bicolor (L.) Moench) du Nord du Burkina Faso

    African Journals Online (AJOL)

    SARAH

    29 déc. 2014 ... sorghos à grains sucrés ont un cycle court et arrivent donc à maturité avant les autres sorghos et le mil d'où leur exploitation comme aliment de soudure par les paysans. L'organisation de la diversité morphologique des accessions de sorghos à grains sucrés du Nord du. Burkina autour principalement des ...

  19. OPERATION DU FOISONNEMENT

    Directory of Open Access Journals (Sweden)

    Gholamreza Djelveh

    2010-04-01

    Full Text Available Mousses alimentaires sont un sous-ensemble des aliments connus sous le nom de produits fouettés ou des produits aérés. Ils sont des produits formulés avec des qualités telles que la légèreté et la souplesse et sont principalement consommés à l'apéritif ou au dessert. Les produits en mousse obtenue par dispersion d'un gaz dans une matrice alimentaire (la phase continue ont connu un développement croissant au cours des années 80 et 90. Le processus d'aération liés à leurs activités de production est appelée l'expansion ou à fouetter. Le document présente les principaux-paramètres du procédé du point permanent de la formulation, la mise en œuvre processus dans les installations pilotes et à l'échelle industrielle, la caractérisation des produits finis, la base énergétique de l'échelle de processus en place, et le lien entre la formulation, émulsion préparation de l'expansion. Cette vue d'ensemble de l'opération d'expansion continue, nous a permis de mettre en évidence le fait qu'il ya des opérations de l'unité encore mal décrite par le génie des procédés et pour lesquels les méthodes et outils pour l'extrapolation et la prédiction sont encore à leurs balbutiements.

  20. Bioactive amines in Brazilian wines: types, levels and correlation with physico-chemical parameters

    Directory of Open Access Journals (Sweden)

    Solange C. Souza

    2005-01-01

    Full Text Available The levels of ten bioactive amines and the physico-chemical characteristics of Cabernet Sauvignon, Cabernet Franc and Merlot wines from Bento Gonçalves, RS, Brazil, vintage of 1999 were investigated. The physico-chemical characteristics varied significantly: pH from 3.80 to 4.07, total acidity from 67.7 to 85.3 meq/L, alcohol content from 11.45 to 12.46 mL/100 mL and total SO2 from 9.6 to 102 mg/L. Six amines were detected in every sample - spermidine, putrescine, histamine, tyramine, serotonine and phenylethylamine. Total amine levels ranged from 2.03 to 7.60 mg/L. Putrescine was the prevalent amine, contributing with 20 to 66% of total levels. The amine profile and total levels were affected to a greater extent by vinification practices compared to grape type. There was significant correlation between some amines and also between amines and the physico-chemical parameters. Histamine levels were well below limits recommended by several countries.Os teores de aminas bioativas e as características físico-químicas de Cabernet Sauvignon, Cabernet Franc e Merlot da região de Bento Gonçalves, RS, safra de 1999, foram analisados. As características físico-químicas variaram significativamente: pH de 3,80 a 4,07; acidez total de 67,7 a 85,3 meq/L, teor alcoólico de 11,45 a 12,46 mL/100 mL e SO2 total de 9,6 a 102 mg/L. Seis aminas estavam presentes em todas as amostras - espermidina, putrescina, histamina, tiramina, serotonina e feniletilamina. Os teores totais de aminas variaram de 2,03 a 7,60 mg/L. Putrescina foi a amina predominante, contribuindo com 20 a 66% do total. O perfil de aminas foi mais afetado pela vinícola do que pelo tipo de uva. Houve correlação significativa entre aminas e também entre aminas e parâmetros físico-químicos. Os teores de histamina detectados são inferiores aos limites máximos estipulados para o vinho em outros países.

  1. Alimentation du nouveau-ne et du nourrisson dans la region ...

    African Journals Online (AJOL)

    Alimentation du nouveau-ne et du nourrisson dans la region centrale du togo : pratiques familiales et communautaires avant la mise en oeuvre de la strategie « prise en charge integree des maladies de l'enfant »

  2. New potential of the reductive alkylation of amines

    International Nuclear Information System (INIS)

    Gusak, K N; Ignatovich, Zh V; Koroleva, E V

    2015-01-01

    Available data on the reductive alkylation of amines with carbonyl compounds — a key method for the preparation of secondary and tertiary amines — are described systematically. The review provides information on the relevant reducing agents and catalysts and on the use of chiral catalysts in stereo- and enantiocontrolled reactions of amine synthesis. The effect of the reactant and catalyst structures on the reaction rates and chemo- and stereo(enantio)selectivity is considered. The bibliography includes 156 references

  3. Synthesis of aldehyde-linked nucleotides and DNA and their bioconjugations with lysine and peptides through reductive amination.

    Science.gov (United States)

    Raindlová, Veronika; Pohl, Radek; Hocek, Michal

    2012-03-26

    5-(5-Formylthienyl)-, 5-(4-formylphenyl)- and 5-(2-fluoro-5-formylphenyl)cytosine 2'-deoxyribonucleoside mono- (dC(R)MP) and triphosphates (dC(R)TP) were prepared by aqueous Suzuki-Miyaura cross-coupling of 5-iodocytosine nucleotides with the corresponding formylarylboronic acids. The dC(R)TPs were excellent substrates for DNA polymerases and were incorporated into DNA by primer extension or PCR. Reductive aminations of the model dC(R)MPs with lysine or lysine-containing tripeptide were studied and optimized. In aqueous phosphate buffer (pH 6.7) the yields of the reductive aminations with tripeptide III were up to 25 %. Bioconjugation of an aldehyde-containing DNA with a lysine-containing tripeptide was achieved through reductive amination in yields of up to 90 % in aqueous phosphate buffer. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Ionic liquid and solid HF equivalent amine-poly(hydrogen fluoride) complexes effecting efficient environmentally friendly isobutane-isobutylene alkylation.

    Science.gov (United States)

    Olah, George A; Mathew, Thomas; Goeppert, Alain; Török, Béla; Bucsi, Imre; Li, Xing-Ya; Wang, Qi; Marinez, Eric R; Batamack, Patrice; Aniszfeld, Robert; Prakash, G K Surya

    2005-04-27

    Isoparaffin-olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin-olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane-isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, "green" class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.

  5. Fluorescence quenching of Rhodamine B base by two amines

    Science.gov (United States)

    Bakkialakshmi, S.; Selvarani, P.; Chenthamarai, S.

    2013-03-01

    Fluorescence quenching of Rhodamine B base (RhB) in DMF solution has been studied at different concentrations of the amine Triethyl amine (TEA) and n-butyl amine (NBA) at room temperature. It has been observed that the fluorescence intensity of RhB decrease with increase in the concentration of the TEA and NBA. It has been observed that the quenching due to amines proceeds via dynamic quenching process. The rate constants for the quenching process have been calculated using Stern-Volmer equation. Time resolved fluorescence study and 1H NMR spectral study have also been carried out and discussed.

  6. Design of amine modified polymer dispersants for liquid-phase exfoliation of transition metal dichalcogenide nanosheets and their photodetective nanocomposites

    Science.gov (United States)

    Lee, Jinseong; Hahnkee Kim, Richard; Yu, Seunggun; Babu Velusamy, Dhinesh; Lee, Hyeokjung; Park, Chanho; Cho, Suk Man; Jeong, Beomjin; Sol Kang, Han; Park, Cheolmin

    2017-12-01

    Liquid-phase exfoliation (LPE) of transition metal dichalcogenide (TMD) nanosheets is a facile, cost-effective approach to large-area photoelectric devices including photodetectors and non-volatile memories. Non-destructive exfoliation of nanosheets using macromolecular dispersing agents is beneficial in rendering the TMD nanocomposite films suitable for mechanically flexible devices. Here, an efficient LPE of molybdenum disulfide (MoS2) with an amine modified poly(styrene-co-maleic anhydride) co-polymer (AM-PSMA) is demonstrated, wherein the maleic anhydrides were converted into maleic imides with primary amines using N-Boc-(CH2) n -NH2. The exfoliation of nanosheets was facilitated through Lewis acid-base interaction between the primary amine and transition metal. The results demonstrate that the exfoliation depends upon both the fraction of primary amines in the polymer chain and their distance from the polymer backbone. Under optimized conditions of primary amine content and its distance from the backbone, AM-PSMA gave rise to a highly concentrated MoS2 nanosheet suspension that was stable for over 10 d. Exfoliation of several other TMDs was also achieved using the optimized AM-PSMA, indicating the scope of AM-PSMA applications. Furthermore, a flexible composite film of AM-PSMA and MoS2 nanosheets fabricated by vacuum-assisted filtration showed excellent photoconductive performances including a high I on/I off ratio of 102 and a fast photocurrent switching of 300 ms.

  7. Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

    OpenAIRE

    Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

    2013-01-01

    The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

  8. Analysis of primary aromatic amines using precolumn derivatization by HPLC fluorescence detection and online MS identification.

    Science.gov (United States)

    Zhao, Xianen; Suo, Yourui

    2008-03-01

    2-(2-phenyl-1H-phenanthro-[9,10-d]imidazole-1-yl)-acetic acid (PPIA) and 2-(9-acridone)-acetic acid (AAA), two novel precolumn fluorescent derivatization reagents, have been developed and compared for analysis of primary aromatic amines by high performance liquid chromatographic fluorescence detection coupled with online mass spectrometric identification. PPIA and AAA react rapidly and smoothly with the aromatic amines on the basis of a condensation reaction using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) as dehydrating catalyst to form stable derivatives with emission wavelengths at 380 and 440 nm, respectively. Taking six primary aromatic amines (aniline, 2-methylaniline, 2-methoxyaniline, 4-methylaniline, 4-chloroaniline, and 4-bromoaniline) as testing compounds, derivatization conditions such as coupling reagent, basic catalyst, reaction temperature and time, reaction solvent, and fluorescent labeling reagent concentration have also been investigated. With the better PPIA method, chromatographic separation of derivatized aromatic amines exhibited a good baseline resolution on an RP column. At the same time, by online mass spectrometric identification with atmospheric pressure chemical ionization (APCI) source in positive ion mode, the PPIA-labeled derivatives were characterized by easy-to-interpret mass spectra due to the prominent protonated molecular ion m/z [M + H](+) and specific fragment ions (MS/MS) m/z 335 and 295. The linear range is 24.41 fmol-200.0 pmol with correlation coefficients in the range of 0.9996-0.9999, and detection limits of PPIA-labeled aromatic amines are 0.12-0.21 nmol/L (S/N = 3). Method repeatability, precision, and recovery were evaluated and the results were excellent for the efficient HPLC analysis. The most important argument, however, was the high sensitivity and ease-of-handling of the PPIA method. Preliminary experiments with wastewater samples collected from the waterspout of a paper mill and its nearby soil where

  9. Poly(Amido Amine)s containing agmatine and butanol side chains as efficient gene carriers

    NARCIS (Netherlands)

    Won, Young-Wook; Ankone, Martinus J.K.; Engbersen, Johannes F.J.; Feijen, Jan; Kim, S.W.

    2016-01-01

    A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of

  10. Ecologie du phytoplancton du lac Kivu

    Directory of Open Access Journals (Sweden)

    Sarmento, H.

    2009-01-01

    Full Text Available Microbiological, Biochemical and Genetic Potential of Freeze Dried Starter Cultures of Acetic Acid Bacteria Isolated from Tropical Products Found in Sub-Saharan Africa and Intended for Use in the Production of Vinegar. The International Assessment of Agricultural Science and Technology for Development (IAASTD is a unique international effort that evaluates the relevance, quality and effectiveness of agricultural knowledge, science, and technology (AKST, the effectiveness of public and private sector policies as well as institutional arrangements in relation to AKST. The purpose of IAASTD is to assess the impact of AKST on hunger, poverty, nutrition, human health, and environmental and social sustainability, in order to formulate options for actions to use AKST more effectively to facilitate sustainable development. The IAASTD report concludes that business as usual is not an option, successfully meeting development and sustainability goals and responding to new priorities and changing circumstances would require a fundamental shift in agricultural knowledge, science, and technology.

  11. Modular functionalization of allenes to aminated stereotriads.

    Science.gov (United States)

    Adams, Christopher S; Boralsky, Luke A; Guzei, Ilia A; Schomaker, Jennifer M

    2012-07-04

    Nitrogen-containing stereotriads, compounds with three adjacent stereodefined carbons, are commonly found in biologically important molecules. However, the preparation of molecules bearing these motifs can be challenging. Herein, we describe a modular oxidation protocol which converts a substituted allene to a triply functionalized amine of the form C-X/C-N/C-Y. The key step employs a Rh-catalyzed intramolecular conversion of the allene to a strained bicyclic methylene aziridine. This reactive intermediate is further elaborated to the target products, often in one reaction vessel and with effective transfer of the axial chirality of the allene to point chirality in the stereotriad.

  12. Oxyfunctionalization of the Remote C-H Bonds of Aliphatic Amines by Decatungstate Photocatalysis.

    Science.gov (United States)

    Schultz, Danielle M; Lévesque, François; DiRocco, Daniel A; Reibarkh, Mikhail; Ji, Yining; Joyce, Leo A; Dropinski, James F; Sheng, Huaming; Sherry, Benjamin D; Davies, Ian W

    2017-11-27

    Aliphatic amines, oxygenated at remote positions within the molecule, represent an important class of synthetic building blocks to which there are currently no direct means of access. Reported herein is an efficient and scalable solution that relies upon decatungstate photocatalysis under acidic conditions using either H 2 O 2 or O 2 as the terminal oxidant. By using these reaction conditions a series of simple and unbiased aliphatic amine starting materials can be oxidized to value-added ketone products. Lastly, NMR spectroscopy using in situ LED-irradiated samples was utilized to monitor the kinetics of the reaction, thus enabling direct translation of the reaction into flow. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Mechanistic insight into benzenethiol catalyzed amide bond formations from thioesters and primary amines

    DEFF Research Database (Denmark)

    Stuhr-Hansen, Nicolai; Bork, Nicolai; Strømgaard, Kristian

    2014-01-01

    The influence of arylthiols on cysteine-free ligation, i.e. the reaction between an alkyl thioester and a primary amine forming an amide bond, was studied in a polar aprotic solvent. We reacted the ethylthioester of hippuric acid with cyclohexylamine in the absence or presence of various quantities...... of thiophenol (PhSH) in a slurry of disodium hydrogen phosphate in dry DMF. Quantitative conversions into the resulting amide were observed within a few hours in the presence of equimolar amounts of thiophenol. Ab initio calculations showed that the reaction mechanism in DMF is similar to the well-known aqueous...... reaction mechanism. The energy barrier of the catalyzed amidation reaction is approximately 40 kJ mol(-1) lower than the non-catalyzed amidation reaction. At least partially this can be explained by a hydrogen bond from the amine to the π-electrons of the thiophenol, stabilizing the transition state...

  14. Controlling Nitrosamines, Nitramines, and Amines in Amine-Based CO₂ Capture Systems with Continuous Ultraviolet and Ozone Treatment of Washwater.

    Science.gov (United States)

    Dai, Ning; Mitch, William A

    2015-07-21

    Formation of nitrosamines and nitramines from reactions between flue gas NOx and the amines used in CO2 capture units has arisen as a significant concern. Washwater scrubbers can capture nitrosamines and nitramines. They can also capture amines, preventing formation of nitrosamines and nitramines downwind by amine reactions with ambient NOx. The continuous application of UV alone, or a combination of UV and ozone to the return line of a washwater treatment unit was evaluated to control the accumulation of nitrosamines, nitramines and amines in a laboratory-scale washwater unit. With model secondary amine solvents ranging from nonvolatile diethanolamine to volatile morpholine, application of 272-537 mJ/cm(2) UV incident fluence alone reduced the accumulation of nitrosamines and nitramines by approximately an order of magnitude. Modeling indicated that the gains achieved by UV treatment should increase over time, because UV treatment converts the time dependence of nitrosamine accumulation from a quadratic to a linear function. Ozone (21 mg/L) maintained low steady-state concentrations of amines in the washwater. While modeling indicated that more than 80% of nitrosamine accumulation in the washwater was associated with reaction of washwater amines with residual NOx, a reduction in nitrosamine accumulation rates due to ozone oxidation of amines was not fully realized because the ozonation products of amines reduced nitrosamine photolysis rates by competing for photons.

  15. Le plurilinguisme du perroquet

    Directory of Open Access Journals (Sweden)

    Manuel Mühlbacher

    2012-05-01

    Full Text Available La figure du perroquet occupe une position ambiguë face à la question de la traduction. Il est capable d’imiter des paroles en toutes les langues, mais il n’est capable d’en comprendre aucune — il ne peut que répéter des sons, c’est-à-dire des signifiants. Le traducteur semble faire le contraire quand il passe d’une langue à une autre en tâchant de transmettre une signification semblable par d’autres signes. L’article vise à discuter le rôle du traducteur et sa relation, éventuellement équivoque, au perroquet, en analysant la traduction allemande de Trois Contes par André Stoll et Cora van Kleffens. Un décalage au niveau sémantique peut éclairer l’interprétation du texte, par exemple en explicitant des allusions sous-jacentes, tandis que le transfert de la syntaxe française en allemand pose souvent des problèmes considérables. Comment le traducteur peut-il reproduire des structures syntaxiques qui n’existent pas en allemand, mais qui ne cessent de revenir dans le texte français ? Que faire si le texte se met à jouer au perroquet et finit par se singer lui-même ? André Stoll et Cora van Kleffens ont su trouver des stratégies pour affronter ces difficultés.The figure of the parrot holds an ambiguous position towards the question of translation. It is able to imitate all languages, but it will never understand any of them – its only skill is to mimic sounds, i.e. mere signifiers. On the contrary, the translator seems to be the antithesis of the parrot when he moves from one language to another. He endeavours to convey a similar meaning, but by different signs. The article aims at discussing the role of the translator and his or her eventually equivocal relation to the parrot by means of analysing the German translation of Trois Contes by André Stoll and Cora van Kleffens. Whereas a semantic divergence can result in a different tendency on the level of interpretation, as in the case of an underlying

  16. Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination

    KAUST Repository

    Moulin, Solenne; Dentel, Hé lè ne; Pagnoux-Ozherelyeva, Anastassiya; Gaillard, Sylvain; Poater, Albert; Cavallo, Luigi; Lohier, Jean Franç ois; Renaud, Jean Luc

    2013-01-01

    . Festival of amination: Two series of modified Knölker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight

  17. Catalytic oxidation of 2-aminophenols and ortho hydroxylation of aromatic amines by tyrosinase

    International Nuclear Information System (INIS)

    Toussaint, O.; Lerch, K.

    1987-01-01

    The usual substrates of tyrosinase, a copper-containing monooxygenase (EC 1.14.18.1), are monophenols and o-diphenols which are both converted to o-quinones. In this paper, the authors studied the reaction of this enzyme with two new classes of substrates: aromatic amines and o-aminophenols, structural analogues of monophenols and o-diphenols, respectively. They undergo the same catalytic reactions (ortho hydroxylation and oxidation), as documented by product analysis and kinetic studies. In the presence of tyrosinase, arylamines and o-aminophenols are converted to o-quinone imines, which are isolated as quinone anils or phenoxazones. As an example, in the presence of tyrosinase, 2-amino-3-hydroxybenzoic acid (an o-aminophenol) is converted to cinnabarinic acid, a well-known phenoxazone, while p-aminotoluene (an aromatic amine) gives rise to the formation of 5-amino-2-methyl-1,4-benzoquinone 1-(4-methylanil). Kinetic studies using an oxygen electrode show that arylamines and the corresponding monophenols exhibit similar Michaelis constants. In contrast, the reaction rates observed for aromatic amines are relatively slow as compared to monophenols. The enzymatic conversion of arylamines by tryosinase is different from the typical ones: N-oxidation and ring hydroxylation without further oxidation. This difference originates from the regiospecific hydroxylation (ortho position) and subsequent oxidation of the intermediate o-aminophenol to the corresponding o-quinone imine. Finally, the well-know monooxygenase activity of tyrosinase was also confirmed for the aromatic amine p-aminotoluene, with 18 O 2

  18. Etat Du Magnesium Dans Quelques Sols Sales Du Sud Et Du ...

    African Journals Online (AJOL)

    étude a été réalisée sur 86 échantillons de sols provenant du Centre et du Sud de l´Irak. L\\'expérimentation a consisté, d´une part, à calculer les différents sels dominants dans les sols salés par la méthode de combinaison hypothétique et, ...

  19. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d\\'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  20. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Administrateur

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  1. Agmatine deiminase pathway genes in Lactobacillus brevis are linked to the tyrosine decarboxylation operon in a putative acid resistance locus

    NARCIS (Netherlands)

    Lucas, Patrick M.; Blancato, Victor S.; Claisse, Olivier; Magni, Christian; Lolkema, Juke S.; Lonvaud-Funel, Aline

    In lactic acid bacteria (LAB), amino acids and their derivatives may be converted into amine-containing compounds designated biogenic amines, in pathways providing metabolic energy and/ or acid resistance to the bacteria. In a previous study, a pathway converting tyrosine to tyramine was detected in

  2. Study of isobutyric acid reactivity by electron spin resonance and infrared spectroscopy of the sodium salt and of 1-vanado-11-molybdophosphoric acid; Etude de la reactivite de l`acide isobutyrique par spectroscopie infrarouge et resonance paramagnetique electronique du sel de sodium et de l`acide de l`ion 1-vanado-11-molybdophosphorique

    Energy Technology Data Exchange (ETDEWEB)

    Rabia, C.; Bettahar, M.M. [Universite des sciences et de technologies, Houari-Boumediene, Algiers (Algeria); Fournier, M. [Universite des Sciences et technologies de Lille, 59 - Villeneuve d`Ascq (France)

    1997-11-01

    The alkaline salt 1-vanado-11-molybdo-phosphore acid as been investigated in isobutyric absorption-desorption-re-oxidation cycles by IR and ESR spectroscopies in comparison to the bulk acid compound. The stability of the active phase in catalysis seems to be related to the formation of a cubic phase depending strongly on the presence of water vapor in the gas stream. This phase can be generated from an alkali precursor subject to a moderate thermal treatment leading to a dispersion of di-oxovanadium cation into the alkali-12-molybdophosphate lattice. (authors) 14 refs.

  3. Isotopic data to study the mechanism of the oxidation of mercaptoacetic acid; Donnees isotopiques pour l'etude du mecanisme d'oxydation de l'acide mercaptoacetique; Izotopnyj metod issledovaniya mekhanizma okisleniya merkapgouksusnoj kisloty; Estudio del mecanismo de oxidacion del acido mercaptoacetico por medio de datos obtenidos con radioisotopos

    Energy Technology Data Exchange (ETDEWEB)

    Gal, D [Central Isotope Laboratory, University of Szeged (Hungary); Guczi, L [Department of Radiology, Elelmiszeripari Kutato Intezet, Budapest (Hungary)

    1962-03-15

    Numerous researchers have been studying the liquid-phase autoxidation by molecular oxygen of compounds containing a mercapto group. It has been stated that, in the course of the reaction, sulphide is formed, but the exact mechanism of this process has not been determined. The oxidation of mercaptoacetic acid, at 50{sup o}C and at a pH of 8, was investigated both in the presence of Complexon IV and in the presence of iron-ions. Na{sub 2}S, labelled with S{sup 35}, was introduced into the system and it was determined that this sulphide considerably increases the rate of the oxygen uptake both in the processes catalysed by trivalent iron and free of iron-ions. In the course of the reaction the concentration of the sulphide, its specific activity and its total activity were measured. In using these data and on the basis of the kinetic isotopic method developed by Neiman and co-workers, it was possible to calculate the rate of sulphide formation and its further oxidation. In comparing these data with other kinetic data, it is shown that the oxidation of mercaptoacetic acid in the liquid phase is a branching chain reaction; one of its principal chains being the formation of Na{sub 2}S and its further oxidation. Moreover, it was determined that sulphate is formed in the course of the reaction only through the inorganic sulphide. Iron-ions catalyse the formation of organic disulphide and therefore also have influence on the sulphide formation. (author) [French] De nombreux chercheurs ont etudie l'autoxydation des composes contenant un groupe mercaptan par l'oxygene moleculaire en phase liquide. Ils ont trouve qu'il y avait formation de sulfure au cours de la reaction, mais le mecanisme exact de ce processus n'a pas ete determine. L'oxydation de l'acide mercaptoacetique a 50{sup o}C et pour un pH de 8 a ete etudiee en presence de complexone IV et egalement; en presence de fer. Du Na{sub 2}S marque au {sup 35}S a ete introduit dans le systeme et on a constate que le Na{sub 2

  4. Thermodynamics of organic mixtures containing amines

    International Nuclear Information System (INIS)

    Gonzalez, Juan Antonio; Mozo, Ismael; Fuente, Isaias Garcia de la; Cobos, Jose Carlos

    2006-01-01

    Binary mixtures containing pyridine (PY), or 2-methylpyridine (2MPY) or 3-methylpyridine (3MPY) or 4-methylpyridine (4MPY) and an organic solvent as benzene, toluene, alkane, or 1-alkanol are investigated in the framework of DISQUAC. The corresponding interaction parameters are reported. The model describes accurately a whole set of thermodynamic properties: vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE), solid-liquid equilibria (SLE), molar excess Gibbs energies (G E ), molar excess enthalpies (H E ), molar excess heat capacities at constant pressure (C P E ) and the concentration-concentration structure factor (S CC (0)). It is remarkable that DISQUAC correctly predicts the W-shaped curve of the C P E of the pyridine + n-hexadecane system. The model can be applied successfully to mixtures with strong positive or negative deviations from the Raoult's law. DISQUAC improves the theoretical results from UNIFAC (Dortmund version). The replacement of pyridine by a methylpyridine leads to a weakening of the amine-amine interactions, ascribed to the steric effect caused by the methyl group attached to the aromatic ring. This explains that for a given solvent (alkane, 1-alkanol) H E (pyridine)>H E (methylpyridine)

  5. Reducing tube bundle deposition with alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Frattini, P.L.

    1998-01-01

    Particle deposition rates have been measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates an order of magnitude greater than those measured for magnetite, although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) ammonia (0.51) : dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat transfer mechanism from nucleate boiling to two-phase forced convection through a thin film. (author)

  6. Reducing tube bundle deposition using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Frattini, P.L.

    1999-07-01

    Particle deposition rates were measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled, using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates 10 times greater than those measured for magnetite although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) : ammonia (0.51) dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat-transfer mechanism from nucleate boiling to 2-phase forced-convection through a thin film. (author)

  7. Le bal du loup

    CERN Multimedia

    Happy Children's Home

    2013-01-01

    The Bord'eau amateur theatre group will graciously perform a play of their creation Le bal du loup Saturday 19 October 2013 at 20:00 Sunday 20 October at 17:00 in the Théâtre des Grottes Rue Louis Favre 43, 1201 Genève Children from age 12 upwards. Summary: The new-elected mayoress of a small village would like to clean up the town by prohibiting alcohol and getting rid of its prostitutes. Then along comes « Massimo Lupo » the pimp... The performances will be given to support the Happy Children's Home charity, which runs a foster-home in Pokhara for Nepali children:  http://www.happychildrenshome.org/ Admission : minimum charge of 10 CHF per person requested, to cover the cost of technical assistance and theatre rental. Any profit will be used solely for the foster-home. At the end of each performance members of the HCH charity will be happy to answer any questions you may have. The theatre has 86 seats, thank you for reserv...

  8. Conditions allowing the formation of biogenic amines in cheese

    NARCIS (Netherlands)

    Joosten, H.M.L.J.

    1988-01-01

    A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.

    The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine

  9. Amine-selective bioconjugation using arene diazonium salts.

    Science.gov (United States)

    Diethelm, Stefan; Schafroth, Michael A; Carreira, Erick M

    2014-08-01

    A novel bioconjugation strategy is presented that relies on the coupling of diazonium terephthalates with amines in proteins. The diazonium captures the amine while the vicinal ester locks it through cyclization, ensuring no reversibility. The reaction is highly efficient and proceeds under mild conditions and short reaction times. Densely functionalized, complex natural products were directly coupled to proteins using low concentrations of coupling partners.

  10. Effects of dietary amines on the gut and its vasculature.

    Science.gov (United States)

    Broadley, Kenneth J; Akhtar Anwar, M; Herbert, Amy A; Fehler, Martina; Jones, Elen M; Davies, Wyn E; Kidd, Emma J; Ford, William R

    2009-06-01

    Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and beta-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

  11. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    KAUST Repository

    Qi, Genggeng; Fu, Liling; Duan, Xiaonan; Choi, Brian Hyun; Abraham, Michael; Giannelis, Emmanuel P.

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing

  12. Astramol polypropyleneimine dendrimers as Norrish Type II amine synergists

    NARCIS (Netherlands)

    Jansen, J.F.G.A.; Dias, A.A.; Hartwig, H.; Janssen, R.A.J.

    2000-01-01

    UV-curable coatings for various applications . In most of these applications they serve a dual role ie as initiator and as oxygen scavenger. Dimethylethanolamine is one of the more frequently employed aliphatic amines. However, this amine is a highly volatile . AstramolTM polypropyleneimine

  13. The Azomethine Ylide Route to Amine C–H Functionalization: Redox-Versions of Classic Reactions and a Pathway to New Transformations

    Science.gov (United States)

    2016-01-01

    Conspectus Redox-neutral methods for the functionalization of amine α-C–H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C–H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet–Spengler, and Kabachnik–Fields reactions, Friedel–Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C–H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic

  14. The azomethine ylide route to amine C-H functionalization: redox-versions of classic reactions and a pathway to new transformations.

    Science.gov (United States)

    Seidel, Daniel

    2015-02-17

    Conspectus Redox-neutral methods for the functionalization of amine α-C-H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C-H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet-Spengler, and Kabachnik-Fields reactions, Friedel-Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C-H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic processes, have been

  15. Cellulose sulphuric acid as a biodegradable catalyst for conversion ...

    Indian Academy of Sciences (India)

    This article describes simple and efficient method for the diazotization and azidation of different aromatic amines over cellulose sulphuric acid, sodium nitrite and sodium azide under mild conditions at room temperature. Various aryl amines possessing electron-withdrawing groups or electron-donating groups have been ...

  16. Factors affecting the photovoltaic behavior of inverted polymer solar cells using various indium tin oxide electrodes modified by amines with simple chemical structures

    Energy Technology Data Exchange (ETDEWEB)

    Kusumi, Takuji [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Kuwabara, Takayuki, E-mail: tkuwabar@se.kanazawa-u.ac.jp [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Research Center for Sustainable Energy and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Yamaguchi, Takahiro [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Taima, Tetsuya [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Research Center for Sustainable Energy and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Takahashi, Kohshin, E-mail: ktakaha@se.kanazawa-u.ac.jp [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan); Research Center for Sustainable Energy and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan)

    2015-09-30

    In a glass–indium tin oxide (ITO)/amine/regioregular poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C{sub 61} butyric acid methyl ester (PCBM)/poly(3,4-ethylenedioxylenethiophene):poly(4-styrene sulfonic acid) (PEDOT:PSS)/Au cell, which uses small molecule amine-modified ITO as the electron collection electrode, a light-soaking effect under irradiation of simulated sunlight was restrained considerably compared with in an ITO/P3HT:PCBM/PEDOT:PSS/Au cell containing bare ITO. That is, the time taken to arrive at a saturated V{sub oc} from the initial V{sub oc} became short when the ionization potential (I{sub P}) of ITO reduced by the amine modification, and consequently both of its saturated V{sub oc} and power conversion efficiency (PCE) improved. The I{sub P} decreased with an increase in the number (N) of amino groups in a single amine molecule, because the basic amino groups can efficiently neutralize any acidic hydroxyl groups on ITO through a multipoint interaction. The superior performance of the cell containing the amine-modified electrode with large N was perhaps because the energy mismatch formed by a contact between ITO and acceptor PCBM reduced, and consequently the rate of electron collection at ITO increased. - Highlights: • Surface-modification of ITO electrode with low molecular weight amines • Ionization potential of ITO was decreased by forming an electrical double layer. • Light-soaking effect has been observed by irradiating white light. • The light-soaking effect mainly improved the open-circuit photovoltage. • Open-circuit photovoltage was limited by ionization potential of amine-modified ITO.

  17. Factors affecting the photovoltaic behavior of inverted polymer solar cells using various indium tin oxide electrodes modified by amines with simple chemical structures

    International Nuclear Information System (INIS)

    Kusumi, Takuji; Kuwabara, Takayuki; Yamaguchi, Takahiro; Taima, Tetsuya; Takahashi, Kohshin

    2015-01-01

    In a glass–indium tin oxide (ITO)/amine/regioregular poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C_6_1 butyric acid methyl ester (PCBM)/poly(3,4-ethylenedioxylenethiophene):poly(4-styrene sulfonic acid) (PEDOT:PSS)/Au cell, which uses small molecule amine-modified ITO as the electron collection electrode, a light-soaking effect under irradiation of simulated sunlight was restrained considerably compared with in an ITO/P3HT:PCBM/PEDOT:PSS/Au cell containing bare ITO. That is, the time taken to arrive at a saturated V_o_c from the initial V_o_c became short when the ionization potential (I_P) of ITO reduced by the amine modification, and consequently both of its saturated V_o_c and power conversion efficiency (PCE) improved. The I_P decreased with an increase in the number (N) of amino groups in a single amine molecule, because the basic amino groups can efficiently neutralize any acidic hydroxyl groups on ITO through a multipoint interaction. The superior performance of the cell containing the amine-modified electrode with large N was perhaps because the energy mismatch formed by a contact between ITO and acceptor PCBM reduced, and consequently the rate of electron collection at ITO increased. - Highlights: • Surface-modification of ITO electrode with low molecular weight amines • Ionization potential of ITO was decreased by forming an electrical double layer. • Light-soaking effect has been observed by irradiating white light. • The light-soaking effect mainly improved the open-circuit photovoltage. • Open-circuit photovoltage was limited by ionization potential of amine-modified ITO.

  18. Biogenic amines degradation by microorganisms isolated from cheese

    Directory of Open Access Journals (Sweden)

    Irena Butor

    2017-01-01

    Full Text Available The aim of this study was the isolation and characterization of microorganisms able to degrade biogenic amines and their identification. Individual microorganisms were obtained by isolation from commercially available foodstuffs and food produced in the technological laboratories of Faculty of Technology, Tomas Bata University in Zlín and subsequently identified by MALDI-TOF MS. The results of MALDI-TOF MS identification were verified by 16S rRNA sequenation. In this work was studied the ability of 5 bacterial strains positive to biogenic amines degradation isolated from dairy products to decrease biogenic amines content in vitro and quantified reduction in the concentration of biogenic amines tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine and tyramine. The level of degradation (decrease of biogenic amines was determined on the base of the ability to grow in media with biogenic amines as the sole source carbon and nitrogen. The isolated strains with the ability of degradation of one or more biogenic amines were cultured in medium supplemented with relevant biogenic amines, the media derivatized with dansyl chloride and these amines separated by HPLC at a wavelength of 254 nm. From five tested strains identified as Bacillus subtilis, Bacillus pumilus, Enterobacter cloacae, Rhizobium radiobacter and Acinetobacter pitii, isolated from gouda type cheese, the greatest ability of degradation was observed in Bacillus subtilis, which was capable to degrade almost all amount of histamine, cadaverine and putrescine. Other four strains showed a lower rate of degradation than Bacillus subtilis, but the ability to degrade biogenic amines with these microorganisms was still significant.

  19. A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

    NARCIS (Netherlands)

    Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

    2005-01-01

    A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

  20. Dual C-H functionalization of N-aryl amines: synthesis of polycyclic amines via an oxidative Povarov approach.

    Science.gov (United States)

    Min, Chang; Sanchawala, Abbas; Seidel, Daniel

    2014-05-16

    Iminium ions generated in situ via copper(I) bromide catalyzed oxidation of N-aryl amines readily undergo [4 + 2] cycloadditions with a range of dienophiles. This method involves the functionalization of both a C(sp(3))-H and a C(sp(2))-H bond and enables the rapid construction of polycyclic amines under relatively mild conditions.

  1. Effets de la microdose sur la production du niébé, du mil et du ...

    African Journals Online (AJOL)

    Effets de la microdose sur la production du niébé, du mil et du sorgho en fonction la toposéquence. Fatimata Saba, Sibiri Jean Baptiste Taonda, Idriss Serme, Alimata A. Bandaogo, Augustin P. Sourwema, Adama Kabre ...

  2. Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

    NARCIS (Netherlands)

    Wasewar, Kailas L.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

    2002-01-01

    Lactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation-based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid-amine (solvent) system used. The equilibrium

  3. Dynamique des populations du foreur des tiges du cacaoyer ...

    African Journals Online (AJOL)

    SARAH

    30 nov. 2014 ... déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de cacao en. Côte d'ivoire. Méthodologie et résultats : L'étude a été réalisée de 2009 à 2013 dans les plantations villageoises de la région du Haut-Sassandra en Côte d'Ivoire. Les variations des taux d'attaques ...

  4. Dynamique des populations du foreur des tiges du cacaoyer ...

    African Journals Online (AJOL)

    Objectif : Le foreur de tiges du cacaoyer, Eulophonotus myrmeleon Felder cause aujourd'hui d'énormes dégâts dans les cacaoyères ivoiriennes. La présente étude vise à déterminer les périodes de fortes attaques de ce déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de ...

  5. Deacidification of oils and fats of biological origine by aqueous solutions of tertiary amines*

    Directory of Open Access Journals (Sweden)

    Peter Siegfried

    2001-01-01

    Full Text Available Deacidification of triacylglycerols by extraction is investigated using aqueous solutions of amines as extractants. Tertiary amines with boiling points ranging between 100° and 170°C, such as 2-methylamino-diethanol, 2-dimethylamino-ethanol, 4-methylmorpholine, 1-dimethylamino-2-propanol etc. were found to be suitable substances. Especially the deacidification by aqueous solutions of 2-dimethylamino-ethanol (DMAE was amply investigated as it is used as an active agent in remedies. Amazingly gelatinous soap stocks are not formed, when the concentration of DMAE exceeds 20% if the free fatty acid content of the oil is below 15%. Two liquid phases are formed in systems composed of triacylglyceroles and aqueous solutions containing 20 to 80% DMAE. Palm oil containing 4.3 wt.% free fatty acids was mixed with an equal amount of an aqueous solution of 30 wt.% DMAE at 60°C. In equilibrium an extract containing 86 wt.% free fatty acids (solvents deducted and a raffinate of 0.09 wt.% free fatty acids are obtained. Loss of neutral oil being 0.7 wt.%.

  6. Gestion durable du paysage

    Directory of Open Access Journals (Sweden)

    Jean-David Gerber

    2009-03-01

    Full Text Available Le paysage est de plus en plus perçu comme une ressource. À ce titre, il est nécessaire de trouver des instruments juridiques, politiques ou économiques susceptibles de gérer cette « ressource-paysage » sur le long terme. Le gouvernement suisse a introduit récemment l’instrument des parcs naturels régionaux, organisés selon le modèle français, dans sa législation de protection de la nature et du paysage. Une mise en regard des nouveaux parcs avec des structures de gestion beaucoup plus anciennes, les bourgeoisies et les corporations, permet de mettre en évidence les forces et les faiblesses de chacun de ces instruments dans leur contribution à résoudre les rivalités d’usage entre acteurs utilisant ou influençant la ressource paysage. Cette comparaison permet de formuler des recommandations pratiques concernant la gestion de cette ressource.The landscape is increasingly perceived as a resource. For this reason, it is necessary to find legal, political and economic instruments that will succeed in managing this “resource landscape” in the long term. The Swiss government recently introduced the instrument of regional nature parks into the legislation governing nature and landscape preservation; the proposed parks are organized on the basis of the French model. The examination of the new parks from the perspective of much older management structures, i.e. the civic municipalities (bourgeoisies and corporations, makes it possible to demonstrate the strengths and weaknesses of each of these instruments in their contribution to the resolution of use rivalries between actors who use or influence the resource landscape. This comparison also enables the formulation of practical recommendations regarding the management of this resource.

  7. Le Developmental Entrepreneurship Program du Massachusetts ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Faire en sorte que les étudiants venant des pays en développement pour étudier au MIT retournent ensuite dans leurs pays respectifs afin d'y concrétiser leurs idées est un souci majeur du MIT, des bailleurs de fonds et du milieu du développement. Ce projet palliera à ce souci en soutenant la formation des fellows du ...

  8. Les dispositifs du Net art

    OpenAIRE

    Fourmentraux, Jean-Paul

    2010-01-01

    La pratique du Net art radicalise la question du potentiel communicationnel d’un média —Internet— qui constitue tout à la fois le support technique, l’outil créatif et le dispositif social de l’œuvre. Les technologies de l’information et de la communication (TIC) placent en effet l’œuvre d’art au cœur d’une négociation socialement distribuée entre l’artiste et le public. L’article est focalisé sur cette construction collective du Net art et sur ses mises en scènes. Il montre le travail artist...

  9. Direct ToF-SIMS analysis of organic halides and amines on TLC plates

    Energy Technology Data Exchange (ETDEWEB)

    Parent, Alexander A. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Anderson, Thomas M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Michaelis, David J. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Jiang, Guilin [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Savage, Paul B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Linford, Matthew R. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States)]. E-mail: mrlinford@chem.byu.edu

    2006-07-30

    It has been reported that: 'direct analysis of thin layer chromatography (TLC) plates with secondary ion mass spectrometry (SIMS) yields no satisfactory results' (J. Chromatogr. A 1084 (2005) 113-118). While this statement appears to be true in general, we have identified two important classes of compounds, organic halides and amines, that appear to yield to such direct analyses. For example, five organic halides with diverse structures were eluted on normal phase TLC plates. In all cases the halide signals in the negative ion time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra were notably stronger than the background signals. Similarly, a series of five organic amines with diverse structures were directly analyzed by positive ion ToF-SIMS. In all but one of the spectra characteristic, and sometimes even quasi-molecular ions, were observed. Most likely, the good halide ion yields are largely a function of the electronegativity of the halogens. We also propose that direct analysis of amines on normal phase silica gel is facilitated by the acidity, i.e., proton donation, of surface silanol groups.

  10. Direct ToF-SIMS analysis of organic halides and amines on TLC plates

    International Nuclear Information System (INIS)

    Parent, Alexander A.; Anderson, Thomas M.; Michaelis, David J.; Jiang, Guilin; Savage, Paul B.; Linford, Matthew R.

    2006-01-01

    It has been reported that: 'direct analysis of thin layer chromatography (TLC) plates with secondary ion mass spectrometry (SIMS) yields no satisfactory results' (J. Chromatogr. A 1084 (2005) 113-118). While this statement appears to be true in general, we have identified two important classes of compounds, organic halides and amines, that appear to yield to such direct analyses. For example, five organic halides with diverse structures were eluted on normal phase TLC plates. In all cases the halide signals in the negative ion time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra were notably stronger than the background signals. Similarly, a series of five organic amines with diverse structures were directly analyzed by positive ion ToF-SIMS. In all but one of the spectra characteristic, and sometimes even quasi-molecular ions, were observed. Most likely, the good halide ion yields are largely a function of the electronegativity of the halogens. We also propose that direct analysis of amines on normal phase silica gel is facilitated by the acidity, i.e., proton donation, of surface silanol groups

  11. Determination of Nonvolatile Amines in Foods by Improved Dansyl Derivatization Reaction.

    Science.gov (United States)

    Handa, Ayami; Kawanabe, Hitomi; Ibe, Akihiro

    2017-01-01

    An analytical method for the determination of nonvolatile amines (putrescine, cadaverine, histamine, tyramine, and spermidine) in foods was developed, using an improved dansyl derivatization technique. The five amines were extracted from food with 1% trichloroacetic acid. Three milliliter of extract was applied to a polymer-based strong cation exchange resin mini-column, which was washed with 5 mL of water, and eluted with 5 mL of 1 mol/L potassium carbonate solution. The eluate was dansylated, then 5 mL of toluene was added with shaking. The toluene layer was evaporated. The residue was taken up in 1 mL of acetonitrile and shaken with 1 mL of 5% proline in 1 mol/L potassium carbonate solution. The upper acetonitrile layer was collected, filtered, and subjected to HPLC. The limits of quantitation for putrescine and cadaverine in the samples were both 0.2 μg/g; those of spermidine, tyramine, and histamine were 0.8, 2.0, and 5.0 μg/g, respectively. The average recoveries of the five amines from nine foods exceeded 80%.

  12. Bioconversion of Airborne Methylamine by Immobilized Recombinant Amine Oxidase from the Thermotolerant Yeast Hansenula polymorpha

    Directory of Open Access Journals (Sweden)

    Sasi Sigawi

    2014-01-01

    Full Text Available Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health. The primary amine oxidase (primary amine : oxygen oxidoreductase (deaminating or amine oxidase, AMO; EC 1.4.3.21, a copper-containing enzyme from the thermotolerant yeast Hansenula polymorpha which was overexpressed in baker’s yeast Saccharomyces cerevisiae, was tested for its ability to oxidize airborne methylamine. A continuous fluidized bed bioreactor (CFBR was designed to enable bioconversion of airborne methylamine by AMO immobilized in calcium alginate (CA beads. The results demonstrated that the bioreactor with immobilized AMO eliminates nearly 97% of the airborne methylamine. However, the enzymatic activity of AMO causes formation of formaldehyde. A two-step bioconversion process was therefore proposed. In the first step, airborne methylamine was fed into a CFBR which contained immobilized AMO. In the second step, the gas flow was passed through another CFBR, with alcohol oxidase from the yeast H. polymorpha immobilized in CA, in order to decompose the formaldehyde formed in the first step. The proposed system provided almost total elimination of the airborne methylamine and the formaldehyde.

  13. Artifacts Generated During Azoalkane Peroxy Radical Oxidative Stress Testing of Pharmaceuticals Containing Primary and Secondary Amines.

    Science.gov (United States)

    Nefliu, Marcela; Zelesky, Todd; Jansen, Patrick; Sluggett, Gregory W; Foti, Christopher; Baertschi, Steven W; Harmon, Paul A

    2015-12-01

    We report artifactual degradation of pharmaceutical compounds containing primary and secondary amines during peroxy radical-mediated oxidative stress carried out using azoalkane initiators. Two degradation products were detected when model drug compounds dissolved in methanol/water were heated to 40°C with radical initiators such as 2,2'-azobis(2-methylpropionitrile) (AIBN). The primary artifact was identified as an α-aminonitrile generated from the reaction of the amine group of the model drug with formaldehyde and hydrogen cyanide, generated as byproducts of the stress reaction. A minor artifact was generated from the reaction between the amine group and isocyanic acid, also a byproduct of the stress reaction. We report the effects of pH, initiator/drug molar ratio, and type of azoalkane initiator on the formation of these artifacts. Mass spectrometry and nuclear magnetic resonance were used for structure elucidation, whereas mechanistic studies, including stable isotope labeling experiments, cyanide analysis, and experiments exploring the effects of butylated hydroxyanisole addition, were employed to support the degradation pathways. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. One step gold (bio)functionalisation based on CS{sub 2}-amine reaction

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ines [Centro de Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa (Portugal); Cascalheira, Antonio C. [Lumisense, Lda, Campus Faculdade de Ciencias da Universidade de Lisboa, Ed. ICAT, Campo Grande, 1749-016 Lisboa (Portugal); Viana, Ana S., E-mail: anaviana@fc.ul.p [Centro de Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa (Portugal)

    2010-12-01

    Dithiocarbamates have been regarded as alternative anchor groups to thiols on gold surfaces, and claimed to be formed in situ through the reaction between secondary amines and carbon disulphide. In this paper, we further exploit this methodology for a convenient one step biomolecule immobilisation onto gold surfaces. First, the reactivity between CS{sub 2} and electroactive compounds containing amines, primary (dopamine), secondary (epinephrine), and an amino acid (tryptophan) has been investigated by electrochemical methods. Cyclic voltammetric characterisation of the modified electrodes confirmed the immobilisation of all the target compounds, allowing the estimation of their surface concentration. The best result was obtained with epinephrine, a secondary amine, for which a typical quasi-reversible behaviour of surface confined electroactive species could be clearly depicted. Electrochemical reductive desorption studies enabled to infer on the extent of the reaction and on the relative stability of the generated monolayers. Bio-functionalisation studies have been accomplished through the reaction of CS{sub 2} with glucose oxidase in aqueous medium, and the catalytic activity of the immobilised enzyme was evaluated towards glucose, by electrochemical methods in the presence of a redox mediator. Scanning tunnelling microscopy (STM) and Atomic force microscopy (AFM) were used respectively, to characterize the gold electrodes and Glucose Oxidase coverage and distribution on the modified surfaces.

  15. L'administration du travail et la production du droit du travail (1906-1960). : Note de synthèse du rapport de recherche

    OpenAIRE

    Le Crom , Jean-Pierre

    2007-01-01

    Synthèse d'un rapport de recherche dont l'objectif est d'appréhender le rôle de l'administration centrale du travail dans la production du droit du travail. Deux dimensions sont explorées : le profil des rédacteurs et l'organisation des structures.

  16. Poly(Amido Amine)s Containing Agmatine and Butanol Side Chains as Efficient Gene Carriers.

    Science.gov (United States)

    Won, Young-Wook; Ankoné, Marc; Engbersen, Johan F J; Feijen, Jan; Kim, Sung Wan

    2016-04-01

    A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of ABOL in the side chains have shown to improve the overall transfection efficiency of poly(amido amine)s, it is hypothesized that poly(CBA-ABOL/AGM) synthesized at the optimal ratio of both components would result in high transfection efficiency and minimal toxicity. In this study, a series of the poly(CBA-ABOL/AGM) copolymers is synthesized as gene carriers. The polymers are characterized and luciferase transfection efficiencies of the polymers in various cell lines are investigated to select the ideal ratio between AGM and ABOL. The poly(CBA-ABOL/AGM) containing 80% AGM and 20% ABOL has shown the best transfection efficiency with the lowest cytotoxicity, indicating that this polymer is very promising as a potent and nontoxic gene carrier. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Scientific Opinion related to a notification from DuPont Nutrition Biosciences Aps on behenic acid from mustard seeds to be used in the manufacturing of certain emulsifiers pursuant to Article 21(2) of Regulation (EU) No 1169/2011 – for permanent exemption from labelling

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2016-01-01

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion related to a notification from DuPont Nutrition Biosciences Aps on behenic acid from mustard seeds to be used in the manufacturing of certain...... and peptides may not be carried over into behenic acid after the two distillation steps reported in the manufacturing process in amounts beyond 1 mg/kg. The Panel notes that the maximum amount of mustard protein that could be consumed from emulsifiers manufactured from behenic acid (E 470a, E 471 and E 477......) on a single occasion by an adult under the proposed conditions of use would be around 0.00119 mg, which is about 1,000 times lower than the protein doses reported to trigger allergic reactions in mustard-allergic individuals (around 1 mg). On the basis of the data presented, the Panel concludes that oral...

  18. Solvent-free functionalization of carbon nanotube buckypaper with amines

    International Nuclear Information System (INIS)

    Basiuk, Elena V.; Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Abarca-Morales, Edgar; Pérez-Rey, Luis A.; Re, Marilena; Prete, Paola; Lovergine, Nico

    2015-01-01

    Graphical abstract: - Abstract: We demonstrate the possibility of fast and efficient solvent-free functionalization of buckypaper (BP) mats prefabricated from oxidized multiwalled carbon nanotubes (MWCNTs-ox), by using three representative amines of different structure: one monofunctional aliphatic amine, octadecylamine (ODA), one monofunctional aromatic amine, 1-aminopyrene (AP), and one aromatic diamine, 1,5-diaminonaphthalene (DAN). The functionalization procedure, which relies on the formation of amide bonds with carboxylic groups of MWCNTs-ox, is performed at 150–180 °C under reduced pressure and takes about 4 h including auxiliary degassing. The amine-treated BP samples (BP-ODA, BP-AP and BP-DAN, respectively) were characterized by means of a variety of analytical techniques such as Fourier-transform infrared and Raman spectroscopy, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, scanning helium ion microscopy, and atomic force microscopy. The highest amine content was found for BP-ODA, and the lowest one was observed for BP-DAN, with a possible contribution of non-covalently bonded amine molecules in all three cases. Despite of some differences in spectral and morphological characteristics for amine-functionalized BP samples, they have in common a dramatically increased stability in water as compared to pristine BP and, on the other hand, a relatively invariable electrical conductivity.

  19. Réflexion sur l’origine du processus de segmentation du marche du travail

    Directory of Open Access Journals (Sweden)

    Attia Nicole

    2006-01-01

    Full Text Available (francuski Ce travail propose une réflexion sur l'origine du processus de segmentation du marché du travail par rapport à l'entreprise. Se situe-t-elle au sein même de l'entreprise ou en amont, c'est à dire entre les entreprises? Cela revient à se demander si on peut avoir une approche microéconomique ou macroéconomique de la segmentation et, à s'interroger sur le rôle réel tenu par les firmes dans le processus. Déterminant pour la théorie, ce rôle est à repenser selon la réponse apportée à notre question.

  20. BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

    Directory of Open Access Journals (Sweden)

    Radka Flasarová

    2012-02-01

    Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

  1. Analysis of primary aromatic amines (PAA) in black nylon kitchenware 2014

    DEFF Research Database (Denmark)

    Trier, Xenia; Granby, Kit

    is 0,01 mg of substance per kg of food or food simulant. The detection limit applies to the sum of primary aromatic amines released’ Since July 1st 2011, an additional EU regulation has come into place, which states that each consignment of polyamide (nylon) kitchen utensils from China and Hong Kong......% acetic acid as food simulant at an exposure temperature of 100°C and time from ½-4 hours, depending on the foreseeable use of the utensil. The samples were collected by the Norwegian Food Safety Authority at importers and retail shops. Of the 20 PAAs analysed. four PAAs were detected, being aniline (ANL...

  2. Primary amine/CSA ion pair: A powerful catalytic system for the asymmetric enamine catalysis

    KAUST Repository

    Liu, Chen; Zhu, Qiang; Huang, Kuo-Wei; Lu, Yixin

    2011-01-01

    A novel ion pair catalyst containing a chiral counteranion can be readily derived by simply mixing cinchona alkaloid-derived diamine with chiral camphorsulfonic acid (CSA). A mixture of 9-amino(9-deoxy)epi-quinine 8 and (-)-CSA was found to be the best catalyst with matching chirality, enabling the direct amination of α-branched aldehydes to proceed in quantitative yields and with nearly perfect enantioselectivities. A 0.5 mol % catalyst loading was sufficient to catalyze the reaction, and a gram scale enantioselective synthesis of biologically important α-methyl phenylglycine has been successfully demonstrated. © 2011 American Chemical Society.

  3. Accessing 2-substituted piperidine iminosugars by organometallic addition/intramolecular reductive amination: aldehyde vs. nitrone route.

    Science.gov (United States)

    Mirabella, S; Fibbi, G; Matassini, C; Faggi, C; Goti, A; Cardona, F

    2017-11-07

    A dual synthetic strategy to afford 2-substituted trihydroxypiperidines is disclosed. The procedure involved Grignard addition either to a carbohydrate-derived aldehyde or to a nitrone derived thereof, and took advantage of an efficient ring-closure reductive amination strategy in the final cyclization step. An opposite diastereofacial preference was demonstrated in the nucleophilic attack to the two electrophiles, which would finally produce the same piperidine diastereoisomer as the major product. However, use of a suitable Lewis acid in the Grignard addition to the nitrone allowed reversing the selectivity, giving access to 2-substituted piperidines with the opposite configuration at C-2.

  4. Primary amine/CSA ion pair: A powerful catalytic system for the asymmetric enamine catalysis

    KAUST Repository

    Liu, Chen

    2011-05-20

    A novel ion pair catalyst containing a chiral counteranion can be readily derived by simply mixing cinchona alkaloid-derived diamine with chiral camphorsulfonic acid (CSA). A mixture of 9-amino(9-deoxy)epi-quinine 8 and (-)-CSA was found to be the best catalyst with matching chirality, enabling the direct amination of α-branched aldehydes to proceed in quantitative yields and with nearly perfect enantioselectivities. A 0.5 mol % catalyst loading was sufficient to catalyze the reaction, and a gram scale enantioselective synthesis of biologically important α-methyl phenylglycine has been successfully demonstrated. © 2011 American Chemical Society.

  5. Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS).

    Science.gov (United States)

    Nielsen, Claus J; Herrmann, Hartmut; Weller, Christian

    2012-10-07

    This critical review addresses the atmospheric gas phase and aqueous phase amine chemistry that is relevant to potential emissions from amine-based carbon capture and storage (CCS). The focus is on amine, nitrosamine and nitramine degradation, and nitrosamine and nitramine formation processes. A comparison between the relative importance of the various atmospheric sinks for amines, nitrosamines and nitramines is presented.

  6. Bioinspired organocatalytic aerobic C-H oxidation of amines with an ortho-quinone catalyst.

    Science.gov (United States)

    Qin, Yan; Zhang, Long; Lv, Jian; Luo, Sanzhong; Cheng, Jin-Pei

    2015-03-20

    A simple bioinspired ortho-quinone catalyst for the aerobic oxidative dehydrogenation of amines to imines is reported. Without any metal cocatalysts, the identified optimal ortho-quinone catalyst enables the oxidations of α-branched primary amines and cyclic secondary amines. Mechanistic studies have disclosed the origins of different performances of ortho-quinone vs para-quinone in biomimetic amine oxidations.

  7. Un Nouveau Monde du Savoir

    International Development Research Centre (IDRC) Digital Library (Canada)

    Si les effets de la mondialisation sur l'économie, la politique ou encore les ..... Il souligne l'importance cruciale d'un plan stratégique d'internationalisation, ...... Lors du recrutement de nouveaux professeurs ( lorsque cette situation est ...

  8. rive gauche du fleuve Rimac

    International Development Research Centre (IDRC) Digital Library (Canada)

    tégée du fleuve et les terrains vagues d'une zone industrielle. .... Ces deux diagnostics sont d'importants outils qui contri- bueront à une meilleure planification ... conditions et instruments nécessaires pour améliorer la situation financière des ...

  9. Voorwoord Forward | du Plessis | Lexikos

    African Journals Online (AJOL)

    J.CM.D. du Plessis. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions ...

  10. Charte du Conseil des Gouverneurs

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    7. favoriser des communications ouvertes et franches entre le personnel, la direction ..... de dresser le procès-verbal des réunions du Conseil et de ses comités et de veiller à ce ... et des résultats qu'il obtient, et non de sa gestion quotidienne.

  11. Bases biologiques du comportement social

    CERN Document Server

    Laborit, H

    1994-01-01

    Pour bien comprendre le comportement humain dans un environnement social,il est necessaire de comprendre comment fonctionne le systÂ?me nerveux central. L'une des principales fonctions du cerveau est de crÂ?er des relations entre leshumains.. .................

  12. Peroxidase-mediated binding of aromatic amine carcinogens to tissue DNA

    International Nuclear Information System (INIS)

    Wise, R.W.; Lakshmi, V.M.; Zenser, T.V.; Davis, B.B.

    1986-01-01

    Benzidine is a aromatic amine bladder carcinogen in man and dog which requires endogenous metabolic activation. Dog bladder microsomes activate benzidine to bind glutathione and DNA by a peroxidatic but not a mixed-function oxidase mediated pathway. Prostaglandin H synthase was responsible for peroxidatic metabolism. This study was designed to assess benzidine metabolism in a whole cell system. Rabbit renal medullary slices (100 mg/ml) were incubated for 60 min. in Krebs-Ringer bicarbonate buffer containing 100 μM 3 H-benzidine and 250 μM arachidonic acid. Arachidonic acid increased 3-(glutathione-S-yL)-benzidine, a product of peroxidatically activated benzidine, (6-fold) and 3 H-benzidine binding to endogenous DNA (4-fold). Indomethacin (100 μM) completely inhibited arachidonic acid-mediated increases in conjugate formation and DNA binding. HPLC analysis of the media demonstrated benzidine (95% of total 3 H), 3-(glutathion-S-yL)-benzidine (1%) and two unidentified peaks (4%). These results are consistent with the hydroperoxidase activity of prostaglandin H synthase mediating metabolic activation of benzidine to bind tissue nucleophiles in a whole cell system. Inhibition of peroxidatic activation of aromatic amines to bind DNA may prevent initiation of bladder cancer

  13. Strong cation exchange-type chiral stationary phase for enantioseparation of chiral amines in subcritical fluid chromatography.

    Science.gov (United States)

    Wolrab, Denise; Kohout, Michal; Boras, Mario; Lindner, Wolfgang

    2013-05-10

    A new strong cation exchange type chiral stationary phase (SCX CSP) based on a syringic acid amide derivative of trans-(R, R)-2-aminocyclohexanesulfonic acid was applied to subcritical fluid chromatography (SFC) for separation of various chiral basic drugs and their analogues. Mobile phase systems consisting of aliphatic alcohols as polar modifiers and a broad range of amines with different substitution patterns and lipophilicity were employed to evaluate the impact on the SFC retention and selectivity characteristics. The observed results point to the existence of carbonic and carbamic acid salts formed as a consequence of reactions occurring between carbon dioxide, the alcoholic modifiers and the amine species present in the sub/supercritical fluid medium, respectively. Evidence is provided that these species are essential for affecting ion exchange between the strongly acidic chiral selector units and the basic analytes, following the well-established stoichiometric displacement mechanisms. Specific trends were observed when different types of amines were used as basic additives. While ammonia gave rise to the formation of the most strongly eluting carbonic and carbamic salt species, simple tertiary amines consistently provided superior levels of enantioselectivity. Furthermore, trends in the chiral SFC separation characteristics were investigated by the systematic variation of the modifier content and temperature. Different effects of additives are interpreted in terms of changes in the relative concentration of the transient ionic species contributing to analyte elution, with ammonia-derived carbamic salts being depleted at elevated temperatures by decomposition. Additionally, in an effort to optimize SFC enantiomer separation conditions for selected analytes, the impact of the type of the organic modifier, temperature, flow rate and active back pressure were also investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

    Directory of Open Access Journals (Sweden)

    Sergey Tin

    2015-05-01

    Full Text Available In the hydrogenation of sluggish unactivated enamine substrates, Rh complexes of electron-deficient phosphines are demonstrated to be far more reactive catalysts than those derived from triphenylphosphine. These operate at low catalyst loadings (down to 0.01 mol % and are able to reduce tetrasubstituted enamines. The use of the sustainable and environmentally benign solvent (R-limonene for the reaction is also reported with the amine isolated by acid extraction.

  15. Influence of amine-grafted multi-walled carbon nanotubes on physical and rheological properties of PMMA-based nanocomposites

    International Nuclear Information System (INIS)

    Kim, Ki-Seok; Park, Soo-Jin

    2011-01-01

    In this work, poly(methyl methacrylate) (PMMA) was grafted onto amine treated multi-walled carbon nanotubes (NH-MWNTs) and the physical and rheological properties of the NH-MWNTs-g-PMMA nanocomposites were investigated. The graft reaction of NH-MWNTs and the PMMA matrix was confirmed from the change of the N 1S peaks, including those of amine oxygen and amide oxygen, by X-ray photoelectron spectroscopy (XPS). The thermal and mechanical properties of the NH-MWNT-g-PMMA nanocomposites were enhanced by the graft reaction between NH-MWNTs and PMMA matrix. In addition, the viscosity of the nanocomposites was increased with the addition of NH-MWNTs. Storage (G') and loss modulus (G'') were significantly increased by increase in the NH-MWNT content compared to acid-treated MWNTs/PMMA nanocomposites. This increase was attributed to the strong interaction by the grafting reaction between NH-MWNTs and the PMMA matrix. - Graphical abstract: This describes the increase of mechanical properties in NH-MWNTs-g-PMMA hybrid composites with different NH-MWNT contents. Highlights: → Aminized carbon nanotubes are used as reinforcement for poly(methylmethacrylate). → Poly(methylmethacrylate) is grafted on aminized carbon nanotubes by thermal reaction. → Grafting of carbon nanotubes and polymer provide enhanced physical properties. → It was due to the strong interaction between carbon nanotubes and polymer matrix.

  16. Functional evolution of the trace amine associated receptors in mammals and the loss of TAAR1 in dogs

    Directory of Open Access Journals (Sweden)

    Westmoreland Susan V

    2010-02-01

    Full Text Available Abstract Background The trace amine associated receptor family is a diverse array of GPCRs that arose before the first vertebrates walked on land. Trace amine associated receptor 1 (TAAR1 is a wide spectrum aminergic receptor that acts as a modulator in brain monoaminergic systems. Other trace amine associated receptors appear to relate to environmental perception and show a birth-and-death pattern in mammals similar to olfactory receptors. Results Across mammals, avians, and amphibians, the TAAR1 gene is intact and appears to be under strong purifying selection based on rates of amino acid fixation compared to neutral mutations. We have found that in dogs it has become a pseudogene. Our analyses using a comparative genetics approach revealed that the pseudogenization event predated the emergence of the Canini tribe rather than being coincident with canine domestication. By assessing the effects of the TAAR1 agonist β-phenylethylamine on [3H]dopamine uptake in canine striatal synaptosomes and comparing the degree and pattern of uptake inhibition to that seen in other mammals, including TAAR1 knockout mice, wild type mice and rhesus monkey, we found that the TAAR1 pseudogenization event resulted in an uncompensated loss of function. Conclusion The gene family has seen expansions among certain mammals, notably rodents, and reductions in others, including primates. By placing the trace amine associated receptors in an evolutionary context we can better understand their function and their potential associations with behavior and neurological disease.

  17. Validation of an HPLC-UV method for the identification and quantification of bioactive amines in chicken meat

    Directory of Open Access Journals (Sweden)

    D.C.S. Assis

    2016-06-01

    Full Text Available ABSTRACT A high-performance liquid chromatography with ultraviolet detection (HPLC-UV method was validated for the study of bioactive amines in chicken meat. A gradient elution system with an ultraviolet detector was used after extraction with trichloroacetic acid and pre-column derivatization with dansyl chloride. Putrescine, cadaverine, histamine, tyramine, spermidine, and spermine standards were used for the evaluation of the following performance parameters: selectivity, linearity, precision, recovery, limits of detection, limits of quantification and ruggedness. The results indicated excellent selectivity, separation of all amines, a coefficient of determination greater than 0.99 and recovery from 92.25 to 102.25% at the concentration of 47.2mg.kg-1, with a limit of detection at 0.3mg.kg-1 and a limit of quantification at 0.9mg.kg-1 for all amines, with the exception of histamine, which exhibited the limit of quantification, of 1mg.kg-1. In conclusion, the performance parameters demonstrated adequacy of the method for the detection and quantification of bioactive amines in chicken meat.

  18. Variation of MCPA, metribuzine, methyltriazine-amine and glyphosate degradation, sorption, mineralization and leaching in different soil horizons

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Carsten S. [Geological Survey of Denmark and Greenland, Department of Geochemistry, DK-1350 Copenhagen K (Denmark); University of Copenhagen, Department of Natural Sciences, DK-1958 Frederiksberg C (Denmark)], E-mail: csj@geus.dk; Keur, Peter van der [Geological Survey of Denmark and Greenland, Department of Hydrology, DK-1350 Copenhagen K (Denmark); Iversen, Bo V. [University of Aarhus, Danish Institute of Agricultural Sciences, Department of Agroecology, Research Centre Foulum, DK-8830 Tjele (Denmark); Rosenberg, Per [Geological Survey of Denmark and Greenland, Department of Geochemistry, DK-1350 Copenhagen K (Denmark); Barlebo, Heidi C. [Geological Survey of Denmark and Greenland, Department of Hydrology, DK-1350 Copenhagen K (Denmark); Torp, Soren [University of Aarhus, Danish Institute of Agricultural Sciences, Department of Agroecology, Research Centre Foulum, DK-8830 Tjele (Denmark); Vosgerau, Henrik [Geological Survey of Denmark and Greenland, Department of Quaternary Geology, DK-1350 Copenhagen K (Denmark); Juhler, Rene K.; Ernstsen, Vibeke; Rasmussen, Jim; Brinch, Ulla Catrine [Geological Survey of Denmark and Greenland, Department of Geochemistry, DK-1350 Copenhagen K (Denmark); Jacobsen, Ole Horbye [University of Aarhus, Danish Institute of Agricultural Sciences, Department of Agroecology, Research Centre Foulum, DK-8830 Tjele (Denmark)

    2008-12-15

    Pesticide mineralization and sorption were determined in 75 soil samples from 15 individually drilled holes through the vadose zone along a 28 km long transect of the Danish outwash plain. Mineralization of the phenoxyacetic acid herbicide MCPA was high both in topsoils and in most subsoils, while metribuzine and methyltriazine-amine was always low. Organic matter and soil pH was shown to be responsible for sorption of MCPA and metribuzine in the topsoils. The sorption of methyltriazine-amine in topsoil was positively correlated with clay and negatively correlated with the pH of the soil. Sorption of glyphosate was tested also high in the subsoils. One-dimensional MACRO modeling of the concentration of MCPA, metribuzine and methyltriazine-amine at 2 m depth calculated that the average concentration of MCPA and methyltriazine-amine in the groundwater was below the administrative limit of 0.1 {mu}g/l in all tested profiles while metribuzine always exceeded the 0.1 {mu}g/l threshold value. - Variation in pesticide sorption and degradation ability in 15 soil profiles are highly dependent on the pesticide but can often be described by pedo-transfer functions and used to differentiate pesticide leaching ability.

  19. Variation of MCPA, metribuzine, methyltriazine-amine and glyphosate degradation, sorption, mineralization and leaching in different soil horizons

    International Nuclear Information System (INIS)

    Jacobsen, Carsten S.; Keur, Peter van der; Iversen, Bo V.; Rosenberg, Per; Barlebo, Heidi C.; Torp, Soren; Vosgerau, Henrik; Juhler, Rene K.; Ernstsen, Vibeke; Rasmussen, Jim; Brinch, Ulla Catrine; Jacobsen, Ole Horbye

    2008-01-01

    Pesticide mineralization and sorption were determined in 75 soil samples from 15 individually drilled holes through the vadose zone along a 28 km long transect of the Danish outwash plain. Mineralization of the phenoxyacetic acid herbicide MCPA was high both in topsoils and in most subsoils, while metribuzine and methyltriazine-amine was always low. Organic matter and soil pH was shown to be responsible for sorption of MCPA and metribuzine in the topsoils. The sorption of methyltriazine-amine in topsoil was positively correlated with clay and negatively correlated with the pH of the soil. Sorption of glyphosate was tested also high in the subsoils. One-dimensional MACRO modeling of the concentration of MCPA, metribuzine and methyltriazine-amine at 2 m depth calculated that the average concentration of MCPA and methyltriazine-amine in the groundwater was below the administrative limit of 0.1 μg/l in all tested profiles while metribuzine always exceeded the 0.1 μg/l threshold value. - Variation in pesticide sorption and degradation ability in 15 soil profiles are highly dependent on the pesticide but can often be described by pedo-transfer functions and used to differentiate pesticide leaching ability

  20. Comparative analyses of laccase-catalyzed amination reactions for production of novel β-lactam antibiotics.

    Science.gov (United States)

    Mikolasch, Annett; Manda, Katrin; Schlüter, Rabea; Lalk, Michael; Witt, Sabine; Seefeldt, Simone; Hammer, Elke; Schauer, Frieder; Jülich, Wolf-Dieter; Lindequist, Ulrike

    2012-01-01

    Seven novel β-lactam antibiotics with activities against Gram-positive bacterial strains, among them methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, were synthesized by amination of 2,5-dihydroxyphenylacetic acid in usable yields (30-60%). These products protected mice against an infection with S. aureus lethal to the control animals. The results show the usefulness of laccase for the synthesis of potential new antibiotics, in addition to the interdependence of the laccase substrates, the amino coupling partners, and the product formation, yield, and activity. The syntheses of β-lactam antibiotics with 2,5-dihydroxyaromatic acid substructures (para-substituted) are then compared with those of 3,4-dihydroxyaromatic acid substructures (ortho-substituted). Para-substituted laccase substrates were better reaction partners in these syntheses than ortho-substituted compounds. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

  1. Preparation and adsorption property of aminated cross linking ...

    Indian Academy of Sciences (India)

    Administrator

    city and blood compatible and biocompatible. The preliminary study on the ... der reduced pressure before being used. Polyvinyl .... above, the difference of the amount of amine groups ... varying of connecting arm in length. Bilirubin mole-.

  2. Two simple amine hydrochlorides from the soft coral Lobophytum strictum

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Naik; Das, B.; Kamat, S.Y.

    Two simple amine hydrochlorides, viz., 1-amino-1, 1-dimethyl-3-oxo-butane hydrochloride (1) (Diacetonamine) and 2, 2, 6, 6-tetramethylpiperidone hydrochloride (2) have been isolated from the fraction of the methanolic extract of the soft coral...

  3. Next Generation Life Support (NGLS): Rapid Cycle Amine Swing Bed

    Data.gov (United States)

    National Aeronautics and Space Administration — The Rapid Cycle Amine (RCA) swingbed has been identified as a technology with high potential to meet the stringent requirements for the next generation spacesuit's...

  4. Structure and activity of Aspergillus nidulans copper amine oxidase

    DEFF Research Database (Denmark)

    McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

    2011-01-01

    Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

  5. Silver-catalyzed synthesis of amides from amines and aldehydes

    Science.gov (United States)

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  6. Synthesis of phenobarbital {sup 14}C - 5 (1964); Synthese du phenobarbital {sup 14}C - 5 (1964)

    Energy Technology Data Exchange (ETDEWEB)

    Benakis, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Phenobarbital (Luminal), well known as a hypnotic agent, plays also an important role in the medical treatment of epilepsy. With the object of studying the metabolism of this medicament in the living system, the synthesis of phenobarbital marked in position 2 of the pyrimidinic ring has been effected. It has been necessary, in order to carry out to research into the metabolism of this product, to have a phenobarbital marked in position 5 of the pyrimidinic ring. This synthesis, making it possible to introduce C-14 into position 5 of the pyrimidinic ring, consists of seven stages starting from C-14 carboxyl benzoic acid having a specific activity of 25 mc/mM. The melting point of the final product is 172 - 173 deg. C and its specific activity is 11.15 mc/mM. The overall radioactive yield of the pure product, with respect to the original benzoic acid (10 mM) is of the order of 3 per cent. The purity of the product has been controlled by paper chromatography; it is of the order of 99 per cent. (author) [French] Le phenobarbital (Luminal) bien connu comme agent hypnotique, joue egalement un role important dans la medication anti-epileptique. Pour l'etude du metabolisme de ce medicament dans l'organisme vivant, nous avons synthetise le phenobarbital marque en position 2 du cycle pyrimidinique. Afin de poursuivre la recherche du metabolisme de ce produit, il a ete necessaire de disposer du phenobarbital marque en position 5 du cycle. pyrimidinique. Cette synthese, permettant l'introduction du {sup 14}C en position 5 du cycle pyrimidinique, comporte sept etapes, au depart de l'acide benzoique carboxyle {sup 14}C, d'une activite specifique de 25 mc/mM. Point de fusion du produit final: 172 - 173 deg. C Activite specifique: 11,15 mC/mM. Rendement total radioactif du produit pur, par rapport a l'acide benzoique de depart sur 10 mM, de l'ordre de 3 pour cent. La purete du produit a ete controlee par chromatographie sur papier; elle est de l'ordre de 99 pour cent. (auteur)

  7. Solvent extraction of cerium (III) with high molecular weight amines

    International Nuclear Information System (INIS)

    Chatterjee, A.; Basu, S.

    1992-01-01

    The use of high molecular weight amines in the extraction of cerium (III) as EDTA complex from neutral aqueous medium is reported. The extraction condition was optimised from the study of effects of several variables like concentration of amine and EDTA pH nature of diluents etc. The method has been applied for the determination of cerium in few mineral samples. (author). 7 refs., 5 tabs

  8. Effects of dietary amines on the gut and its vasculature

    OpenAIRE

    Broadley, Kenneth John; Anwar, Mohammad Akhtar; Herbert, Amy Angharad; Fehler, Martina; Jones, Elen M.; Davies, W. E.; Kidd, Emma Jane; Ford, William Richard

    2009-01-01

    Trace amines, including tyramine and β-phenylethylamine (β-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called ‘friendly’ bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and β-PEA on the contractile activity of gu...

  9. Facile and Green Synthesis of Saturated Cyclic Amines

    Directory of Open Access Journals (Sweden)

    Arruje Hameed

    2017-10-01

    Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

  10. Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

    Science.gov (United States)

    Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

    2018-02-14

    The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

  11. Catalyst Deactivation Reactions : The Role of Tertiary Amines Revisited

    NARCIS (Netherlands)

    Novarino, Elena; Rios, Itzel Guerrero; van der Veer, Siebe; Meetsma, Auke; Hessen, Bart; Bouwkamp, Marco W.

    2011-01-01

    Decamethylzirconocene cation [Cp*2ZrMe](+) (2) decomposes in bromobenzene-d(5) solution to generate sigma-aryl species [Cp*Zr-2(2-C6H4Br-kappa Br,C)][B(C6F5)(4)] (3). This a-bond metathesis reaction is catalyzed by tertiary amines via a two-step mechanism, in which the amine acts as a proton relay.

  12. Comparison of Raman, NIR, and ATR FTIR spectroscopy as analytical tools for in-line monitoring of CO2 concentration in an amine gas treating process

    NARCIS (Netherlands)

    Kachko, A.; Ham, L.V. van der; Bardow, A.; Vlugt, T.J.H.; Goetheer, E.L.V.

    2016-01-01

    Chemical absorption of CO2 using aqueous amine-based solvents is one of the common approaches to control acidic gases emissions to the atmosphere. Improvement in the efficiency of industrial processes requires precise monitoring tools that fit with the specific application. Process monitoring using

  13. A facile synthesis of substituted 2-alkylquinolines through [3+3] annulation between 3-ethoxycyclobutanones and aromatic amines at room temperature.

    Science.gov (United States)

    Shan, Gang; Sun, Xiuyun; Xia, Qian; Rao, Yu

    2011-11-04

    An efficient single-step approach toward the synthesis of 2-alkylquinolines is described. Through a Lewis acid mediated [3+3] annulation reaction between 3-ethoxycyclobutanones and aromatic amines, a variety of multisubstituted 2-alkylquinoline derivatives were prepared regioselectively at room temperature. © 2011 American Chemical Society

  14. IBX-mediated oxidation of unactivated cyclic amines: application in highly diastereoselective oxidative Ugi-type and aza-Friedel-Crafts reactions.

    Science.gov (United States)

    de Graaff, C; Bensch, L; van Lint, Matthijs J; Ruijter, E; Orru, R V A

    2015-10-28

    The first o-iodoxybenzoic acid (IBX) mediated oxidation of unactivated amines to imines is described. A range of meso-pyrrolidines were shown to be suitable substrates. The chemical space was further explored with one-pot oxidative Ugi-type and aza-Friedel-Crafts reactions, which proved to be highly diastereoselective.

  15. 4-oxobutenoic acid towards nitrogen-containing nucleophiles

    Indian Academy of Sciences (India)

    Abstract. A series of novel amino acid derivatives has been synthesized by the reaction of 4-[4-methoxy-. 3-methylphenyl]-4-oxobutenoic acid with primary and secondary amines. The treatment of amino acids with hydrazine afforded pyridazine. Phenylhydrazone was obtained from the reaction of the acid with phenyl.

  16. Review article Herbal extracts and organic acids as natural feed ...

    African Journals Online (AJOL)

    2013-07-16

    Jul 16, 2013 ... time and improved activity of proteolytic enzymes. ... Modern laboratory techniques enable the isolation and characterization of ..... microbial metabolites such as ammonia and biogenic amines. ..... acid determine their efficacy.

  17. Production of biogenic amines in "Salamini italiani alla cacciatora PDO".

    Science.gov (United States)

    Coı X0308 Sson, Jean Daniel; Cerutti, Caterina; Travaglia, Fabiano; Arlorio, Marco

    2004-06-01

    Various fermented and seasoned foods such as cheese, sauerkraut, wine, beer and meat products may contain biogenic amines. The aim of this paper was to describe the presence of some biogenic amines (histamine, tyramine, tryptamine, 2-phenylethylamine) in "Salamini italiani alla cacciatora PDO", a typical fermented-ripened dry sausage widely consumed in Italy. Total level of biogenic amines in commercial samples ranged from 71 to 586 mg kg(-1). The amine recovered in higher concentrations was tyramine (372 mg kg(-1)) followed by histamine (165 mg kg(-1)). The second aim of this work was the quality control of the production in order to determine the parameters influencing the presence of biogenic amines in ripened salami. Sausages sampled for analysis during production, manipulation and ripening showed the presence of tyramine (64.4 mg kg(-1)) only after 15 days of fermentation. All investigated biogenic amines were detected in "Salamini" after 21 days of fermentation. We suggest the control of biogenic as important tool to establish the better condition of preservation of "Salamini italiani alla cacciatore PDO" during their shelf-life.

  18. STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; ZHANG Jingyi; FENG Xinde(S. T. Voong)

    1983-01-01

    Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET>DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET>DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp=K [DMT]1/2 [MEMA]3/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.

  19. Biogenic amine formation and bacterial contribution in Natto products.

    Science.gov (United States)

    Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

    2012-12-01

    Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Paul Celan in Translation: "Du sei wie du"

    Directory of Open Access Journals (Sweden)

    John Felstiner

    1983-09-01

    Full Text Available Translating the lyric poetry of Paul Celan, especially his later poems, carries not only the endemic challenge and difficulty of any verse translation, but the added incentive of doing justice to a writer whose whole recourse after the Holocaust—whose sanctuary, if he was to have any at all—he sought in language itself, specifically in the Muttersprache , the mother tongue that was as well the tongue of those who murdered his mother and father. This essay exposes a process of translating "Du sei wie du" (1970, which perhaps more than any other poem by Celan, at once solicits and defies translation, moving as it does from modern to medieval German, and closing with Hebrew words from Isaiah— a messianic imperative that shows Celan verging as ever on his Jewish identity.

  1. Le parcours migratoire de jeunes ruraux du bled du kif

    Directory of Open Access Journals (Sweden)

    Khalid Mouna

    2015-06-01

    Full Text Available Cet article analyse le parcours migratoire des jeunes ruraux originaires des zones de production du cannabis, jeunes qui cherchent à briser les chaînes de soumission et d’humiliation vécues au quotidien. Pour les jeunes concernés par notre étude, la migration constitue un moyen de s’intégrer dans des réseaux transnationaux et ainsi d’entamer une carrière de beznass (commerçant du cannabis. Ce parcours « initiatique » permet à ces jeunes de revenir au bled avec de nouvelles idées, des moyens accrus, et de jouer un rôle actif dans l’économie locale – qui reste pour eux focalisée sur la production de cannabis, cette dernière restant néanmoins officiellement interdite.

  2. Bassins versants du Loup, de la Cagne et du Malvan

    OpenAIRE

    Lepère, Cédric; Lautier, Laurence; Pellegrino, Emmanuel

    2013-01-01

    Identifiant de l'opération archéologique : 8453 Date de l'opération : 2007 (PC) ; 2007 (PI) Inventeur(s) : Lepère Cédric (AUT) ; Lautier Laurence (AUT) ; Pellegrino Emmanuel (AUT) Une campagne de prospection inventaire a été effectuée pendant trois mois, dans les bassins-versants de la Cagne, du Loup et du Malvan qui regroupent les communes de Cagnes-sur-Mer, Villeneuve-Loubet, La Colle-sur-Loup, Saint-Paul-de-Vence, Vence, Saint-Jeannet, Bezaudun, Tourrettes-sur-Loup, Roquefort-les-Pins, Le ...

  3. Heterocyclic amines in meat and meat products

    Directory of Open Access Journals (Sweden)

    Aliye BULGAN

    2013-06-01

    Full Text Available Heterocyclic amines (HA are the mutagenic/carcinogenic compounds which generate as a result of cooking of red meat, poultry meat and fish fillets at high temperatures. Up to 20 different HAs were detected and classified in the researches that conducted on these types of meats cooked at high temperatures. HAs are the products of Maillard reactions and the Strecker degredation of main precursors such as creatine/creatinine, aminoacid and the polysaccharides. Many physical and chemical factors effect the formation of HAs. Thus, it was reported by many researchers that utilizing coating and marination processes in addition to using natural and synthetic antioxidants and seasonings-plant extracts were effective on inhibiting/decreasing the formation of HAs. Additionally, boiling/steaming and microwave cooking methodologies were recommended instead of barbecuing, grilling or frying to inhibit/decrease the formation of HAs. The HAs formed in meat and meat products and the factors which have effects on the formation of HAs are presented in this review.

  4. Development of I-123-labeled amines for brain studies: localization of I-123 iodophenylalkyl amines in rat brain

    International Nuclear Information System (INIS)

    Winchell, H.S.; Baldwin, R.M.; Lin, T.H.

    1980-01-01

    Localization in rat brain of forty iodophenylalkyl amines labeled with I-123 was evaluated in an attempt to develop I-123-labeled amines useful for brain studies. For the amines studied, the highest activity in brain and the brain-to-blood activity ratios ranked p > m > o as related to iodine position on the benzene ring: for alkyl groups the rank order was α-methylethyl > ethyl > methyl > none; for N additions it was single lipophilic group > H > two lipophilic groups. It is suggested that introduction of a halogen into the ring structure of many amines results in greater concentration of the agent in brain than is seen with the nonhalogenated parent compound. The agent N-isopropyl-p-iodoamphetamine was chosen for further study because, in the rat, it showed high brain activity (1.57%/g) and brain-blood ratio (12.6) at 5 min

  5. Laser Scribed Graphene Biosensor for Detection of Biogenic Amines in Food Samples Using Locally Sourced Materials

    Directory of Open Access Journals (Sweden)

    Diana C. Vanegas

    2018-04-01

    Full Text Available In foods, high levels of biogenic amines (BA are the result of microbial metabolism that could be affected by temperatures and storage conditions. Thus, the level of BA is commonly used as an indicator of food safety and quality. This manuscript outlines the development of laser scribed graphene electrodes, with locally sourced materials, for reagent-free food safety biosensing. To fabricate the biosensors, the graphene surface was functionalized with copper microparticles and diamine oxidase, purchased from a local supermarket; and then compared to biosensors fabricated with analytical grade materials. The amperometric biosensor exhibits good electrochemical performance, with an average histamine sensitivity of 23.3 µA/mM, a lower detection limit of 11.6 µM, and a response time of 7.3 s, showing similar performance to biosensors constructed from analytical grade materials. We demonstrated the application of the biosensor by testing total BA concentration in fish paste samples subjected to fermentation with lactic acid bacteria. Biogenic amines concentrations prior to lactic acid fermentation were below the detection limit of the biosensor, while concentration after fermentation was 19.24 ± 8.21 mg histamine/kg, confirming that the sensor was selective in a complex food matrix. The low-cost, rapid, and accurate device is a promising tool for biogenic amine estimation in food samples, particularly in situations where standard laboratory techniques are unavailable, or are cost prohibitive. This biosensor can be used for screening food samples, potentially limiting food waste, while reducing chances of foodborne outbreaks.

  6. Marche du foncier urbain et promotion du logement au Benin ...

    African Journals Online (AJOL)

    Le marché du foncier urbain au Bénin est un secteur qui met en jeu l'intervention de plusieurs acteurs publics et privés mais également de l'informel. La notion de « foncier urbain » utilisée dans cet article englobe les acceptions et les utilisations faites en architecture, en urbanisme, en aménagement et en gestion urbaine.

  7. Gestion du parc agroforestier du terroir de Vipalogo (Burkina Faso ...

    African Journals Online (AJOL)

    Au Burkina Faso, l'arbre rural fait partie des systèmes de production. Le choix des espèces, leur densité, les modes de gestion ainsi que les besoins à satisfaire, obéissent à des critères propres aux producteurs. C'est pour comprendre ces logiques paysannes de la gestion du parc agroforestier que la présente étude a été ...

  8. Malformations du tube neural en chirurgie pediatrique du chu de ...

    African Journals Online (AJOL)

    encéphalocèle et 6 cas de sipina bifida. La cure chirurgicale a été le principal mode de prise en charge des patients. Seuls 91,38% des cas ont été opérés. Pour toutes les malformations du tube neural, nous avons enregistré 7 décès dont 2 décès ...

  9. Co2 chemosorption by functionalized amino acid derivatives

    DEFF Research Database (Denmark)

    2015-01-01

    The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized amino acid.......The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized amino acid....

  10. Transition Metal Free C-N Bond Forming Dearomatizations and Aryl C-H Aminations by in Situ Release of a Hydroxylamine-Based Aminating Agent.

    Science.gov (United States)

    Farndon, Joshua J; Ma, Xiaofeng; Bower, John F

    2017-10-11

    We outline a simple protocol that accesses directly unprotected secondary amines by intramolecular C-N bond forming dearomatization or aryl C-H amination. The method is dependent on the generation of a potent electrophilic aminating agent released by in situ deprotection of O-Ts activated N-Boc hydroxylamines.

  11. Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

    KAUST Repository

    Yue, Huifeng

    2017-03-15

    An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

  12. Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

    KAUST Repository

    Yue, Huifeng; Guo, Lin; Liao, Hsuan-Hung; Cai, Yunfei; Zhu, Chen; Rueping, Magnus

    2017-01-01

    An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

  13. Probing the Compound I-like reactivity of a bare high-valent oxo iron porphyrin complex: the oxidation of tertiary amines.

    Science.gov (United States)

    Chiavarino, Barbara; Cipollini, Romano; Crestoni, Maria Elisa; Fornarini, Simonetta; Lanucara, Francesco; Lapi, Andrea

    2008-03-12

    The mechanisms of oxidative N-dealkylation of amines by heme enzymes including peroxidases and cytochromes P450 and by functional models for the active Compound I species have long been studied. A debated issue has concerned in particular the character of the primary step initiating the oxidation sequence, either a hydrogen atom transfer (HAT) or an electron transfer (ET) event, facing problems such as the possible contribution of multiple oxidants and complex environmental effects. In the present study, an oxo iron(IV) porphyrin radical cation intermediate 1, [(TPFPP)*+ Fe(IV)=O]+ (TPFPP = meso-tetrakis (pentafluorophenyl)porphinato dianion), functional model of Compound I, has been produced as a bare species. The gas-phase reaction with amines (A) studied by ESI-FT-ICR mass spectrometry has revealed for the first time the elementary steps and the ionic intermediates involved in the oxidative activation. Ionic products are formed involving ET (A*+, the amine radical cation), formal hydride transfer (HT) from the amine ([A(-H)]+, an iminium ion), and oxygen atom transfer (OAT) to the amine (A(O), likely a carbinolamine product), whereas an ionic product involving a net initial HAT event is never observed. The reaction appears to be initiated by an ET event for the majority of the tested amines which included tertiary aliphatic and aromatic amines as well as a cyclic and a secondary amine. For a series of N,N-dimethylanilines the reaction efficiency for the ET activated pathways was found to correlate with the ionization energy of the amine. A stepwise pathway accounts for the C-H bond activation resulting in the formal HT product, namely a primary ET process forming A*+, which is deprotonated at the alpha-C-H bond forming an N-methyl-N-arylaminomethyl radical, A(-H)*, readily oxidized to the iminium ion, [A(-H)]+. The kinetic isotope effect (KIE) for proton transfer (PT) increases as the acidity of the amine radical cation increases and the PT reaction to the base

  14. Development of versatile isotopic labeling reagents for profiling the amine submetabolome by liquid chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Zhou, Ruokun; Huan, Tao; Li, Liang

    2015-01-01

    Highlights: • Two new reagents were developed for chemical isotope labeling mass spectrometry (MS). • They could be used to label amine-containing metabolites in a metabolomic sample. • The labeled metabolites could be detected with much improved sensitivity in MS. • One of the reagents could also help generate useful MS/MS spectra for structural analysis. • These reagents should be useful for quantitative metabolomics. - Abstract: Metabolomic profiling involves relative quantification of metabolites in comparative samples and identification of the significant metabolites that differentiate different groups (e.g., diseased vs. controls). Chemical isotope labeling (CIL) liquid chromatography–mass spectrometry (LC–MS) is an enabling technique that can provide improved metabolome coverage and metabolite quantification. However, chemical identification of labeled metabolites can still be a challenge. In this work, a new set of isotopic labeling reagents offering versatile properties to enhance both detection and identification are described. They were prepared by a glycine molecule (or its isotopic counterpart) and an aromatic acid with varying structures through a simple three-step synthesis route. In addition to relatively low costs of synthesizing the reagents, this reaction route allows adjusting reagent property in accordance with the desired application objective. To date, two isotopic reagents, 4-dimethylaminobenzoylamido acetic acid N-hydroxylsuccinimide ester (DBAA-NHS) and 4-methoxybenzoylamido acetic acid N-hydroxylsuccinimide ester (MBAA-NHS), for labeling the amine-containing metabolites (i.e., amine submetabolome) have been synthesized. The labeling conditions and the related LC–MS method have been optimized. We demonstrate that DBAA labeling can increase the metabolite detectability because of the presence of an electrospray ionization (ESI)-active dimethylaminobenzoyl group. On the other hand, MBAA labeled metabolites can be fragmented

  15. Development of versatile isotopic labeling reagents for profiling the amine submetabolome by liquid chromatography–mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ruokun; Huan, Tao; Li, Liang, E-mail: Liang.Li@ualberta.ca

    2015-06-30

    Highlights: • Two new reagents were developed for chemical isotope labeling mass spectrometry (MS). • They could be used to label amine-containing metabolites in a metabolomic sample. • The labeled metabolites could be detected with much improved sensitivity in MS. • One of the reagents could also help generate useful MS/MS spectra for structural analysis. • These reagents should be useful for quantitative metabolomics. - Abstract: Metabolomic profiling involves relative quantification of metabolites in comparative samples and identification of the significant metabolites that differentiate different groups (e.g., diseased vs. controls). Chemical isotope labeling (CIL) liquid chromatography–mass spectrometry (LC–MS) is an enabling technique that can provide improved metabolome coverage and metabolite quantification. However, chemical identification of labeled metabolites can still be a challenge. In this work, a new set of isotopic labeling reagents offering versatile properties to enhance both detection and identification are described. They were prepared by a glycine molecule (or its isotopic counterpart) and an aromatic acid with varying structures through a simple three-step synthesis route. In addition to relatively low costs of synthesizing the reagents, this reaction route allows adjusting reagent property in accordance with the desired application objective. To date, two isotopic reagents, 4-dimethylaminobenzoylamido acetic acid N-hydroxylsuccinimide ester (DBAA-NHS) and 4-methoxybenzoylamido acetic acid N-hydroxylsuccinimide ester (MBAA-NHS), for labeling the amine-containing metabolites (i.e., amine submetabolome) have been synthesized. The labeling conditions and the related LC–MS method have been optimized. We demonstrate that DBAA labeling can increase the metabolite detectability because of the presence of an electrospray ionization (ESI)-active dimethylaminobenzoyl group. On the other hand, MBAA labeled metabolites can be fragmented

  16. L’Harmonie du monde

    Directory of Open Access Journals (Sweden)

    Martine Clouzot

    2003-11-01

    Full Text Available La Bourgogne est particulièrement bien présente et représentée dans l’exposition sur la musique et ses représentations au Moyen Âge organisée par Isabelle Marchesin (université de Poitiers, Christine Laloue (conservatrice du Patrimoine au Musée et Martine Clouzot (université de Bourgogne, au Musée de la Musique à Paris du 26 mars au 27 juin 2004. En Côte-d’Or, à Dijon, la Bibliothèque municipale a donné son accord officiel pour le prêt de la Bible d’Etienne Harding, les Moralia in Job et u...

  17. Les vicissitudes du fret ferroviaire

    OpenAIRE

    DABLANC, L

    2010-01-01

    Dans beaucoup de pays européens, et plus encore en Amérique du Nord et en Asie, le transport de marchandises par le train a augmenté depuis dix ans. Cette activité réduit la part des marchandises acheminées par la route et contribue ainsi au développement durable : un camion émet 8 à 30 fois plus de dioxyde de carbone que le train, pour une distance et une quantité transportée équivalentes. Pourtant, la France a raté ce renouveau. Filiale du groupe public SNCF, la Société Fret SNCF, qui assur...

  18. Identifying and quantifying proteolytic events and the natural N terminome by terminal amine isotopic labeling of substrates.

    Science.gov (United States)

    Kleifeld, Oded; Doucet, Alain; Prudova, Anna; auf dem Keller, Ulrich; Gioia, Magda; Kizhakkedathu, Jayachandran N; Overall, Christopher M

    2011-09-22

    Analysis of the sequence and nature of protein N termini has many applications. Defining the termini of proteins for proteome annotation in the Human Proteome Project is of increasing importance. Terminomics analysis of protease cleavage sites in degradomics for substrate discovery is a key new application. Here we describe the step-by-step procedures for performing terminal amine isotopic labeling of substrates (TAILS), a 2- to 3-d (depending on method of labeling) high-throughput method to identify and distinguish protease-generated neo-N termini from mature protein N termini with all natural modifications with high confidence. TAILS uses negative selection to enrich for all N-terminal peptides and uses primary amine labeling-based quantification as the discriminating factor. Labeling is versatile and suited to many applications, including biochemical and cell culture analyses in vitro; in vivo analyses using tissue samples from animal and human sources can also be readily performed. At the protein level, N-terminal and lysine amines are blocked by dimethylation (formaldehyde/sodium cyanoborohydride) and isotopically labeled by incorporating heavy and light dimethylation reagents or stable isotope labeling with amino acids in cell culture labels. Alternatively, easy multiplex sample analysis can be achieved using amine blocking and labeling with isobaric tags for relative and absolute quantification, also known as iTRAQ. After tryptic digestion, N-terminal peptide separation is achieved using a high-molecular-weight dendritic polyglycerol aldehyde polymer that binds internal tryptic and C-terminal peptides that now have N-terminal alpha amines. The unbound naturally blocked (acetylation, cyclization, methylation and so on) or labeled mature N-terminal and neo-N-terminal peptides are recovered by ultrafiltration and analyzed by tandem mass spectrometry (MS/MS). Hierarchical substrate winnowing discriminates substrates from the background proteolysis products and

  19. Determination of the hydrothermal degradation products of D-(U-14C) glucose and D-(U-14C) fructose by TLC

    International Nuclear Information System (INIS)

    Bonn, G.; Bobleter, O.

    1983-01-01

    Hydrothermal degradation was examined using D-(U- 14 C) glucose and D-(U- 14 C) fructose. By thin layer chromatography with methylene chloride, tetrahydrofuran (THF), acetic acid - 60:20:20 as a mobile phase; it was possible to separate and identify the carbohydrates and their reaction products, glyceraldehyde, dihydroxyacetone, methylglyoxal, glycolaldehyde, 5-hydroxymethylfurfural and furfural. Up to 99% of the initial activity was determined by scintillation counting of the TL-chromatograms. A reaction scheme for the hydrothermal degradation of glucose and fructose was obtained from these results. (author)

  20. L'energie du moustique

    CERN Document Server

    Augereau, J F

    2002-01-01

    ENSEMBLE DE QUATRE ARTICLES - LARGE HADRON COLLIDER: Le dernier accelerateur de particules du CERN, le LEP, produisait des faisceaux d'electrons de 100 GeV chacun. Le LHC, qui accelere des faisceaux de protons, leur communiquera une energie de 7 TeV chacun. Une energie a la fois colossale et derisoire. Un TeV represente a peu pres l'energie cinetique d'un moustique (1/2 page).

  1. Revision des Symphurus du Siboga

    NARCIS (Netherlands)

    Chabanaud, Paul

    1955-01-01

    Ce m’est un devoir particulièrement agréable que de saisir l’occasion de ce petit mémoire pour remercier M. L. F. DE BEAUFORT, M. H. ENGEL, Directeur du Zoologisch Museum, ainsi que M. J. J. HOEDEMAN de l’accueil qu’à diverses reprises, j’ai reçu de leur part, au Zoölogisch Museum, et aussi des

  2. Synthesis of Poly (Amido-Amine) and Its Application for Removal of Metal Ions

    International Nuclear Information System (INIS)

    Siyam, T.; Abdel-Hamid, M.M.; El-Naggar, I.M.

    1999-01-01

    Poly (amido-amine) such as poly(acrylamide-acrylic acid-dimethylaminoethylmethacrylate) P(AM-AA-DMAEM) was prepared by gamma irradiation induced template polymerization of acrylic acid on in the presence of poly(acrylamide-dimethylaminoethylmethacrylate) as a template polymer. The polymerization was studied by a free radical mechanism in aqueous solution and the hydrogel was obtained. The swelling degree of the formed hydrogel increases by increasing the polymer/monomer molar ratio and decreases with increasing the monomer concentration. The swelling degree was also found to depend on the radiation dose. The results showed that the capacity of the obtained hydrogel was found to be maximum at polymer/monomer molar ratio of 1.3. The capacity of the polymeric materials increases with increasing the monomer concentration and decreases with increasing the radiation doses. The metal cations interact with polymeric chains to form a cross-linked structure after cation build-up. Tlus interaction occurs through complex formation between amide and amine groups with cations whereas the carboxylic group interacts by cation-exchange mechanism

  3. Predictors of dietary heterocyclic amine intake in three prospective cohorts.

    Science.gov (United States)

    Byrne, C; Sinha, R; Platz, E A; Giovannucci, E; Colditz, G A; Hunter, D J; Speizer, F E; Willett, W C

    1998-06-01

    Cooking meat creates heterocyclic amines (HCAs) through pyrolysis of amino acids and creatinine. Although recognized as mutagenic, the etiological role of HCA in human cancer is unclear, due to the lack of information on the effect of typical food cooking methods on HCA concentrations and on variation in HCA exposure in populations. We estimated overall daily dietary HCA intake and variation in intake between individuals, using recent data on HCA concentrations in various meats prepared by cooking methods, temperatures, and times common in United States in the 1990s. Random samples of 250 participants from each of three large prospective cohorts were mailed a questionnaire to assess frequency of consumption, cooking method, and typical outside appearance of pan-fried, broiled, and grilled or barbecued chicken, fish, hamburger, and steak; fried, microwaved, and broiled bacon; fried sausage; roast beef; and homemade gravy. The 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and 2-amino-3,4,8-trimethylimidazo[4,5,f]quinoxaline (DiMeIQx) concentrations, measured in composite samples by solid-phase extraction and high-performance liquid chromatography, were assigned to each food, cooking method, and doneness level. The dietary reports showed approximately 30-fold relative variation in 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline intake, 20-fold for 2-amino- -methyl-6-phenylimidazo[4,5-b]pyridine, and over 110-fold for 2-amino-3,4,8-trimethylimidazo[4,5,f]quinoxaline, when the 10th and 90th percentiles of HCA intake were compared (90th/10th percentile value). These reported variations in HCA exposure among participants in these three large cohorts indicates that estimation of HCA intake and determination of association with disease risk are feasible, if additional information on meat cooking methods is obtained.

  4. Actes des 5èmes Journées Scientifiques du GDR3544 Sciences du Bois. Journées Annuelles du GDR 3544 Sciences du Bois

    OpenAIRE

    CHAPLAIN, Myriam; CARE, Sabine; GRIL, Joseph

    2016-01-01

    Le Groupement de Recherche en Sciences du bois (GDR3544 Sciences du Bois) a été créé en 2012 par le CNRS et renouvelé en 2016 pour 5 ans. La mission de ce groupement est : (1) de structurer la recherche sur le bois en France pour lui donner une visibilité nationale, (2) de contribuer au développement de la formation en sciences du bois et (3) de servir de relai aux réseaux internationaux de sciences du bois. Les 5èmes journées annuelles du GDR Bois ont été organisées à Bordeaux, au domaine du...

  5. Original Paper Performances comparées du HDL-cholestérol et du ...

    African Journals Online (AJOL)

    CT/HDL-C) et du HDL-Cholestérol est le meilleur prédicteur du SMet chez les adultes béninois. .... (Canada) et du. Ministère de la Santé du Bénin. Le consentement éclairé écrit a été obtenu de chaque participant avant leur recrutement dans.

  6. Determination of rate constants of N-alkylation of primary amines by 1H NMR spectroscopy.

    Science.gov (United States)

    Li, Chenghong

    2013-09-05

    Macromolecules containing N-diazeniumdiolates of secondary amines are proposed scaffolds for controlled nitrogen oxide (NO) release medical applications. Preparation of these compounds often involves converting primary amine groups to secondary amine groups through N-alkylation. However, N-alkylation results in not only secondary amines but tertiary amines as well. Only N-diazeniumdiolates of secondary amines are suitable for controlled NO release; therefore, the yield of secondary amines is crucial to the total NO load of the carrier. In this paper, (1)H NMR spectroscopy was used to estimate the rate constants for formation of secondary amine (k1) and tertiary amine (k2) for alkylation reagents such as propylene oxide (PO), methyl acrylate (MA), and acrylonitrile (ACN). At room temperature, the ratio of k2/k1 for the three reactions was found to be around 0.50, 0.026, and 0.0072.

  7. Biogenic amines in Italian Pecorino cheese

    Directory of Open Access Journals (Sweden)

    Maria eSchirone

    2012-05-01

    Full Text Available The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (approximately 53.727t of production. Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or thermized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA. Several factors can contribute to the qualitative and quantitative profiles of BA’s in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, aw, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge and the presence of cofactor. Generally, the total content of BA’s can range from about 100-2400 mg/kg, with a prevalence of toxicologically important BA’s, tyramine and histamine. The presence of BA in Pecorino cheeses is becoming increasingly important to consumers and cheese-maker alike, due to the potential threats of toxicity to humans and consequent trade implications.

  8. Effects of plant polyphenols and α-tocopherol on lipid oxidation, microbiological characteristics, and biogenic amines formation in dry-cured bacons.

    Science.gov (United States)

    Wang, Yongli; Li, Feng; Zhuang, Hong; Li, Lianghao; Chen, Xiao; Zhang, Jianhao

    2015-03-01

    Effects of plant polyphenols (tea polyphenol [TP], grape seed extract [GSE], and gingerol) and α-tocopherol on physicochemical parameters, microbiological counts, and biogenic amines were determined in dry-cured bacons at the end of ripening. Results showed that plant polyphenols and α-tocopherol significantly decreased pH, thiobarbituric acid reactive substances content, and total volatile basic nitrogen (TVBN) compared with the control (P amine contents in dry-cured bacons were affected by plant polyphenols or α-tocopherol, with TP being the most effective (P amines, and spoilage microorganisms, whereas PC2 grouped the TVBN, tyramine, 2-phenylethylamine, yeast, and molds. These findings suggest that plant polyphenols, especially TP, could be used to process dry-cured bacons to improve the quality and safety of finished products. © 2015 Institute of Food Technologists®

  9. 35 Typologie des eaux de surface du bassin du Sebou par multi ...

    African Journals Online (AJOL)

    PR BOKO

    2Service de protection de la qualité de l'eau, Agence du Bassin Hydraulique du ... pour montrer l'évolution de la qualité biologique des eaux de surface du ..... Biological Indicators of Freshwater Pollution and Environmental Management,.

  10. Régionalisation du recrutement du personnel de santé au Burkina ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Régionalisation du recrutement du personnel de santé au Burkina Faso ... le ministère a adopté une politique de recrutement régionalisé de certaines catégories du ... de comprendre le contexte dans lequel une telle stratégie a été formulée, ...

  11. La disparition du temps en gravitation quantique

    OpenAIRE

    Saint-Ours, Alexis de

    2012-01-01

    Le but de ce travail est d’examiner l’incidence philosophique de la gravitation quantique sur le concept de temps. Je cherche à montrer qu’elle conduit à une disparition du temps comme dimension et ouvre la voie à une compréhension du temps comme variation et même à l’idée de variation pure. En l’absence de temps mécanique, il est cependant possible de définir un temps d’origine thermodynamique. Je montre en quoi cette dissociation du temps mécanique et du temps thermodynamique, fait écho à l...

  12. Acid-base strengths in pyridine

    NARCIS (Netherlands)

    Bos, M.; Dahmen, E.A.M.F.

    1971-01-01

    Although pyridine is a solvent with a low dielectric constant, spectrophotometric determinations show simple dissociation without ion pairs as intermediates for some sulfonphthaleins and polynitrophenols in pyridine. The salts of a number of amines and hydrochloric acid, perchloric acid and picric

  13. Au fil du temps (1976 ou la loi du seuil

    Directory of Open Access Journals (Sweden)

    Isabelle Singer

    2010-04-01

    Full Text Available Ayant choisi de vivre dans un camion, les héros d’Au fil du temps (film de Wim Wenders de 1976 font du seuil une expérience particulière. Celle de la rupture avec toute idée de foyer et celle du refus d’appartenance à la terre natale, cette terre allemande traversée par une frontière le long de laquelle ils vont voyager, et qui les renvoie à chaque instant aux traumatismes de l’Histoire. Sur le pare-brise du camion, l’extérieur (campagnes indifférenciées, villes à l’abandon… et l’intérieur se superposent. Au fil du temps questionne le paysage : il s’agit d’en décoller un à un les mythes qui le recouvrent. L’image alors n’est plus surface mais volume à traverser, à lacérer et découvrir ce qui est tissé dans le paysage. La démarche de Wenders est alors proche de celle d’un de ses contemporains : Anselm Kiefer. Le paysage allemand provoque le rejet parce qu’il y a là toujours plus que le visible : des strates et des strates de culpabilité que le mythe - et c’est sa fonction - a recouvert. Et qu’il s’agira ici, de soulever. Le choix du nomadisme, c’est celui d’un état de l’humanité antérieur à l’idée de patrie. Et c’est aussi celui de la solitude, comme prix à payer à ce refus d’appartenance et à cette mise à jour des mythes. L’appartenance à la terre allemande et à son Histoire est profondément problématique parce que les pères sont fondamentalement coupables. On se reconnaîtra alors des pères de substitution : des pères de cinéma (Nicholas Ray ou Fritz Lang. Et l’on substituera l’Histoire du cinéma à l’Histoire. Bruno est réparateur ambulant de projecteurs et Au fil du temps dressera, au gré de ses pérégrinations, un état des lieux du cinéma allemand des années soixante-dix : déliquescent, colonisé par les images hollywoodiennes. Il faut que cela change : état du cinéma ; état des protagonistes solitaires en quête d’une identit

  14. Formation of Biogenic Amines in Chicken Meat Stored under Modified Atmosphere

    Directory of Open Access Journals (Sweden)

    Leo Gallas

    2010-01-01

    Full Text Available The aim of the study was to investigate the effects of two modified atmospheres with a different combination of gases on selected groups of microorganisms and on concentrations of biogenic amines (BAs in samples of poultry breast muscle. The samples were packaged under modified atmosphere A (75% O2 a 25% CO2 or B (75% N2 and 25% CO2 and stored at temperatures from +2 to +4 °C for 14 days. During the storage period, O2 concentrations in modified atmosphere A (MA A decreased from the initial 74.8 ± 0.3% to 55.9 ± 6.6% at the end of the storage period. In all samples, counts of psychrotrophic bacteria counts, Brochothrix thermosphacta, lactic acid bacteria and coliform microorganism were determined. The tests were made on the packaging day, and then after three, nine and fourteen days of storage. At the end of the storage period, higher numbers of psychrotrophic bacteria (6.5 ± 0.7 log10 cfu g-1, Brochothrix thermosphacta (4.8 ± 0.3 log10 cfu g-1 and lactic acid bacteria (1.7 ± 0.4 log10 cfu g-1 were found on samples packaged under MA A. Samples packaged under modified atmosphere B on the other hand contained higher numbers of coliform bacteria (4.1 ± 0.6 log10 cfu g-1 at the end of the storage period. In addition to microbiological indicators, concentrations of biogenic amines (putrescine, cadaverine, histamine, tyramine, spermine, spermidine and β-phenylethylamine were also determined. In fresh samples and after three days of storage, only spermine and spermidine were found. After 9 and 14 days, also other BAs were detected. The biogenic amine totals at the end of the storage period was 60.0 ± 13.2 mg kg-1 in samples packaged under MA A and 129.0 ± 41.3 mg kg-1 in samples packaged under MA B. The most abundantly represented biogenic amines in samples packaged under MA A were putrescine and spermine (49.7 and 24.8%, respectively, at the end of the storage period, and putrescine and cadaverine in samples packaged under MA B (47.0 and 32

  15. Improved stability and antidiabetic potential of insulin containing folic acid functionalized polymer stabilized multilayered liposomes following oral administration

    DEFF Research Database (Denmark)

    Agrawal, Ashish Kumar; Harde, Harshad; Thanki, Kaushik

    2014-01-01

    The present study reports the folic acid (FA) functionalized insulin loaded stable liposomes with improved bioavailability following oral administration. Liposomes were stabilized by alternating coating of negatively charged poly(acrylic acid) (PAA) and positively charged poly(allyl amine...

  16. Design, Synthesis and Biological Activity of Novel Reversible Peptidyl FVIIa Inhibitors Rh-Catalyzed Enantioselective Synthesis of Diaryl Amines

    DEFF Research Database (Denmark)

    Storgaard, Morten

    functional group tolerance. Unfortunately, these -aryl tetramic acids were too unreactive and ring opening toward the synthesis of the building block did not succeed. However, -aryl tetramic acids are still interesting compounds due to their potential biological activity. The building block 3.15 (P1......-catalyzed enantioselective synthesis of diaryl amines, which is an important class of compounds (Chapter 4). For example it is found in the third generation anti-histaminic agent levocetirizine. Development of efficient synthetic routes is therefore of considerably interest. The rhodium-catalyzed enantioselective synthesis...

  17. Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents

    Directory of Open Access Journals (Sweden)

    Tiina Laaksonen

    2015-11-01

    Full Text Available Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+-dehydroabietylamine (2. The resolution of enantiomers of model compounds [Mosher’s acid (3 and its n-Bu4N salt (4] (guests by (+-dehydroabietyl-N,N-dimethylmethanamine (5 and its ten different ammonium salts (hosts was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide (6. The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various α-substituted carboxylic acids and their n-Bu4N salts in enantiomeric excess (ee determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient.

  18. Regulation of carbon partitioning into carotenes by MPTA, a substituted tertiary amine

    Energy Technology Data Exchange (ETDEWEB)

    Madhavan, S.; Rosenfield, C.L.; Benedict, C.R.

    1986-04-01

    In mature citrus fruits, synthesis and turnover of carotenes appears to be low. Treatment of lemon pieces with the substituted tertiary amine, 2-(4-methylphenoxyl)triethylamine, MPTA, induces the synthesis of carotenes. Exposure of tissue slices (lemon flavedo) to MPTA for 72 hrs results in the production of 29.6 ..mu..g gfrwt/sup -1/ lycopene whereas control slices showed only trace amounts of lycopene. An identical incorporation of /sup 14/C-glucose into sugars, amino acids and organic acids, in both treated and control tissue slices indicates the non-disturbance of fruit respiration by MPTA treatment. Incorporation of /sup 14/C-glucose into carotenes is negligible in mature citrus fruits, but in MPTA treated tissue slices there is a pronounced incorporation of /sup 14/C-glucose into carotenes. MPTA treatment induces the synthesis of carotene enzymes, thus effecting an increased partitioning of glucose into the MVA pathway for carotene synthesis.

  19. Regulation of carbon partitioning into carotenes by MPTA, a substituted tertiary amine

    International Nuclear Information System (INIS)

    Madhavan, S.; Rosenfield, C.L.; Benedict, C.R.

    1986-01-01

    In mature citrus fruits, synthesis and turnover of carotenes appears to be low. Treatment of lemon pieces with the substituted tertiary amine, 2-(4-methylphenoxyl)triethylamine, MPTA, induces the synthesis of carotenes. Exposure of tissue slices (lemon flavedo) to MPTA for 72 hrs results in the production of 29.6 μg gfrwt -1 lycopene whereas control slices showed only trace amounts of lycopene. An identical incorporation of 14 C-glucose into sugars, amino acids and organic acids, in both treated and control tissue slices indicates the non-disturbance of fruit respiration by MPTA treatment. Incorporation of 14 C-glucose into carotenes is negligible in mature citrus fruits, but in MPTA treated tissue slices there is a pronounced incorporation of 14 C-glucose into carotenes. MPTA treatment induces the synthesis of carotene enzymes, thus effecting an increased partitioning of glucose into the MVA pathway for carotene synthesis

  20. The chemistry of amine radical cations produced by visible light photoredox catalysis

    Directory of Open Access Journals (Sweden)

    Jie Hu

    2013-10-01

    Full Text Available Amine radical cations are highly useful reactive intermediates in amine synthesis. They have displayed several modes of reactivity leading to some highly sought-after synthetic intermediates including iminium ions, α-amino radicals, and distonic ions. One appealing method to access amine radical cations is through one-electron oxidation of the corresponding amines under visible light photoredox conditions. This approach and subsequent chemistries are emerging as a powerful tool in amine synthesis. This article reviews synthetic applications of amine radical cations produced by visible light photocatalysis.