WorldWideScience

Sample records for couples aromatic amines

  1. 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

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

    Science.gov (United States)

    Smith, Robert E.; Dolbeare, Frank A.

    1979-01-01

    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, 5-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.

  3. 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.

  4. Determination of primary aromatic amines in water food simulant using solid-phase analytical derivatization followed by gas chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Brede, Cato; Skjevrak, Ingun; Herikstad, Hallgeir

    2003-01-03

    Solid phase analytical derivatization with trifluoroacetic anhydride has been introduced as sample preparation for the determination of primary aromatic amines in water by gas chromatography coupled with mass spectrometry. Water was used as a food simulant for testing migration from laminated flexible food packaging materials. The method was evaluated for 8 primary aromatic amines in 200 ml water samples, which resulted in detection limits in the 0.1-0.4 microg/l range, relative standard deviations in the 4-17% range and acceptable linearity (R2 = 0.997-1.000). Detectable levels of 2,4-diaminotoluene, 2,6-diaminotoluene and 4,4'-methylenedianiline were found in water food simulant from some of the investigated food packaging materials.

  5. Effect of Ionic Liquid on the Determination of Aromatic Amines as Contaminants in Hair Dyes by Liquid Chromatography Coupled to Electrochemical Detection

    Directory of Open Access Journals (Sweden)

    Maria Valnice Boldrin Zanoni

    2012-07-01

    Full Text Available The room temperature ionic liquid (IL 1-butyl-3-methylimidazolium bis-(trifluorometanesulfonylimide BMIm[NTf2] was used as a novel medium for improvement of separation and quantization of 16 aromatic amines typically present as contaminants in consumer products and detected by HPLC coupled to an electrochemical detector. The aromatic amines, namely 4,4'-diaminodiphenylmethane, 4-chloroaniline, 2-methoxy-5-methyl-aniline, 3,3'-dimethylbenzidine, 2,4-diaminotoluidine, 2-chloro-4-nitroaniline, 4,4'-oxydianiline, aniline, 3,3'-dichlorobenzidine, benzidine, 4-aminobiphenyl, o-dianisidine, o-anisidine, o-toluidine, 4,4'-methylene-bis-2-chloroaniline and 2-naphthyl-amine are oxidized in methanol/BMIm[NTf2] at a potential around +0.68V to +0.93V vs. Ag/AgCl at a glassy carbon electrode, which is the base for their determination by HPLC/ED. Using the optimized conditions of methanol/BMIm[NTf2] 70:30 (v/v as mobile phase, flow-rate of 0.8 mL·min−1, column CLC-ODS, Eap = +1.0 V and T = 40 °C analytical curves were constructed for each of the tested amines. Good linearity was obtained in the concentration range of 1.09 mg·L−1 to 217 mg·L−1, with excellent correlation coefficients. The limits of detection reached 0.021 mg·L−1 to 0.246 mg·L−1 and good relative standard deviations (RSD, n = 3 were obtained from the measurements. Satisfactory recovery for each aromatic amine was achieved, ranging from 95 to 103%. The developed method was successfully applied to determine six aromatic amines present as contaminants in commercial hair dye samples.

  6. Graphite Oxide and Aromatic Amines : Size Matters

    NARCIS (Netherlands)

    Spyrou, Konstantinos; Calvaresi, Matteo; Diamanti, Evmorfi A. K.; Tsoufis, Theodoros; Gournis, Dimitrios; Rudolf, Petra; Zerbetto, Francesco

    2015-01-01

    Experimental and theoretical studies are performed in order to illuminate, for first time, the intercalation mechanism of polycyclic aromatic molecules into graphite oxide. Two representative molecules of this family, aniline and naphthalene amine are investigated. After intercalation, aniline

  7. Graphite Oxide and Aromatic Amines : Size Matters

    NARCIS (Netherlands)

    Spyrou, Konstantinos; Calvaresi, Matteo; Diamanti, Evmorfi A. K.; Tsoufis, Theodoros; Gournis, Dimitrios; Rudolf, Petra; Zerbetto, Francesco

    2015-01-01

    Experimental and theoretical studies are performed in order to illuminate, for first time, the intercalation mechanism of polycyclic aromatic molecules into graphite oxide. Two representative molecules of this family, aniline and naphthalene amine are investigated. After intercalation, aniline molec

  8. Aromatic amines sources, environmental impact and remediation

    OpenAIRE

    Pereira,Luciana; Mondal, P. K.; Alves,M. M.

    2015-01-01

    Aromatic amines are widely used industrial chemicals as their major sources in the environment include several chemical industry sectors such as oil refining, synthetic polymers, dyes, adhesives, rubbers, perfume, pharmaceuticals, pesticides and explosives. They result also from diesel exhaust, combustion of wood chips and rubber and tobacco smoke. Some types of aromatic amines are generated during cooking, special grilled meat and fish, as well. The intensive use and production of these comp...

  9. Aromatic amines sources, environmental impact and remediation

    OpenAIRE

    Pereira, Luciana; Mondal, P. K.; Alves, M. M.

    2015-01-01

    Aromatic amines are widely used industrial chemicals as their major sources in the environment include several chemical industry sectors such as oil refining, synthetic polymers, dyes, adhesives, rubbers, perfume, pharmaceuticals, pesticides and explosives. They result also from diesel exhaust, combustion of wood chips and rubber and tobacco smoke. Some types of aromatic amines are generated during cooking, special grilled meat and fish, as well. The intensive use and production of these comp...

  10. Fate and biodegradability of sulfonated aromatic amines

    NARCIS (Netherlands)

    Tan, N.C.G.; Leeuwen, van A.; Voorthuizen, van E.M.; Slenders, P.; Prenafeta, F.X.; Temmink, H.; Lettinga, G.; Field, J.A.

    2005-01-01

    Ten sulfonated aromatic amines were tested for their aerobic and anaerobic biodegradability and toxicity potential in a variety of environmental inocula. Of all the compounds tested, only two aminobenzenesulfonic acid (ABS) isomers, 2- and 4-ABS, were degraded. The observed degradation occurred only

  11. Fate and biodegradability of sulfonated aromatic amines

    NARCIS (Netherlands)

    Tan, N.C.G.; Leeuwen, van A.; Voorthuizen, van E.M.; Slenders, P.; Prenafeta, F.X.; Temmink, H.; Lettinga, G.; Field, J.A.

    2005-01-01

    Ten sulfonated aromatic amines were tested for their aerobic and anaerobic biodegradability and toxicity potential in a variety of environmental inocula. Of all the compounds tested, only two aminobenzenesulfonic acid (ABS) isomers, 2- and 4-ABS, were degraded. The observed degradation occurred only

  12. Determination of urinary aromatic amines in smokers and nonsmokers using a MIPs-SPE coupled with LC-MS/MS method.

    Science.gov (United States)

    Yu, Jingjing; Wang, Sheng; Zhao, Ge; Wang, Bing; Ding, Li; Zhang, Xiaobing; Xie, Jianping; Xie, Fuwei

    2014-05-01

    Urinary aromatic amines (AAs) could be used as biomarkers for human exposure to AAs in cigarette smoke. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of urinary AAs (i.e. 1-naphthylamine (1-NA), 2-naphthylamine (2-NA), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP)) in smokers and nonsmokers. A molecularly imprinted polymers (MIPs) solid phase extraction (SPE) cartridge was applied to purify urine samples and no derivatization reaction was involved. Each analytes used respective stable isotope internal standards, which could well compensate matrix effect. Lower limit of detections (LODs) for four AAs were obtained and in the range of 1.5-5ngL(-1). Recovery ranged from 87.7±4.5% to 111.3±6.4% and precision were less than 9.9%. The method was applied to analyze urine samples of 40 smokers and 10 nonsmokers. The 24h urinary excretion amounts of total AAs were higher for smokers compared with nonsmokers. What's more, 1-NA, 3-ABP and 4-ABP excretion amounts showed significant differences (p<0.05) between smokers and nonsmokers.

  13. STRUCTURAL EFFECT ON VINYL POLYMERIZATION INITIATED WITH AROMATIC TERTIARY AMINE

    Institute of Scientific and Technical Information of China (English)

    CAO Weixiao; FENG Xinde

    1983-01-01

    The polymerization mechanism of various vinyl monomers in the presence of aromatic tertiary amines has been studied. It was found that the mechanisms of different monomers are varied with the structures of monomers. Those monomers, such as methacrylic esters containing α-CH3 group on the double bond could be polymerized with aromatic tertiary amine in the absence of light,while the monomers without α-CH3 group, such as methyl acrylate, acrylonitrile etc. would polymerize only under light.The structural effects, both of the monomer and the amine, on the rate of photopolymerization were studied. The activities of monomers and amines may be arranged in the following orderMonomer: AN>MA>VA>St Amine: DMT>DMA>DMB>DNAIt is revealed that both the electro-negative group on the double bond of monomer which acts as an acceptor and the electro-positive group on the nitrogen atom of amine which acts as a donor would effectively increase the rate of photopolymerization.

  14. Advance in the synthesis of aromatic amine via direct amination

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Arylamines are very common and important organic molecules. Acting as important intermediates in medical and chemical industry, they are widely used in the synthesis of pharmaceuticals, dyes, pesticides, rubber additives, isocyanates and heterocyclic compounds. The traditional methods for the synthesis of arylamines include several steps. The production of aniline, for example, includes the following steps: the production of nitro-benzene by the nitration of benzene, and the reduction of the resulting nitro-benzene by catalytic hydrogenation or other reduction ways[1-6]; or the substitution of phenol or chlorbenzene by amino groups, etc.[7-10]. There are several disadvantages for these methods: low atom utilization, strict operation condition, large amount of by-products and serious environmental pollution, which could not afford for the needs of a sustainable civilization. So there has been growing interest in the direct amination to produce arylamines recently. With the direct methods, the multi- step reaction may change into one step, the atom utilization can be evidently improved, and the by-products H2 or/and H2O are harmless to the environment.

  15. Metabolic activation of aromatic amines and azo dyes.

    Science.gov (United States)

    Bartsch, H

    1981-01-01

    Aromatic amines, amides and nitro compounds are a class of chemicals that produce tumors in a wide variety of tissues in experimental animals, including liver, urinary bladder, forestomach, small intestine, Zymbal's gland, subcutaneous tissue or skin. In man, exposure to some aromatic amines is associated with tumours of the urinary bladder and carcinoma of the renal pelvis. Their biological activity as carcinogens or genotoxic agents is, in all the cases that have been studied in detail, dependent on metabolic activation in vivo, occurring by multiple pathways. Differences in these metabolic pathways may largely account for the differences in tissues and species susceptibilities to cancer induction. Carcinogenicity of aromatic amines or amides is dependent on their oxidation to N-hydroxy derivatives, whilst the carcinogenicity of aromatic nitro compounds is linked to their reduction to hydroxylamines. Further conversion of the N-hydroxylamine or N-hydroxyamide to reactive intermediates can occur in several ways, which include (i) esterification of the N-hydroxy group, (ii) non-enzymic protonation of the nitrogen of the hydroxylamine and (iii) oxidation to a free radical of arylhydroxamic acids. Following generation of such reactive electrophilic intermediates in tissues or cells, macromolecular binding has been observed to nucleic acids and proteins. In many cases, arylamidated and arylaminated products are formed with nucleic acid bases; in the case of the well-studied 2-acetylaminofluorene, nucleophilic atoms of guanine are the predominant site of reaction. Relatively little is known of the structure and biological consequences of DNA adducts formed from other aromatic amines, amides or nitro compounds; more research in these directions is warranted.

  16. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  17. Determination of aromatic amines from textiles using dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Yang, Lu; Yiwei, Wang; Caiying, Lou; Yan, Zhu

    2013-03-01

    A dispersive liquid-liquid microextraction procedure coupled with GC-MS is described for preconcentration and determination of banned aromatic amines from textile samples. Experimental conditions affecting the microextraction procedure were optimized. A mixture of 30 μL chlorobenzene (extraction solvent) and 800 μL ACN (disperser solvent), 5 min extraction time, and 5 mL aqueous sample volume were chosen for the best extraction efficiency by the proposed procedure. Satisfactory linearity (with correlation coefficients >0.9962) and repeatability (<9.78%) were obtained for all 20 aromatic amines; detection limits attained were much lower than the standardized liquid-liquid method. The proposed method has advantages of being quicker and easier to operate, and lower consumption of organic solvent.

  18. Electrochemical degradation of aromatic amines on BDD electrodes.

    Science.gov (United States)

    Pacheco, M J; Santos, V; Ciríaco, L; Lopes, A

    2011-02-28

    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)<η(CA2)<η(CA3)<η(CA4)=0.99. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. BIODEGRADATION OF AROMATIC AMINE COMPOUNDS USING MOVING BED BIOFILM REACTORS

    Directory of Open Access Journals (Sweden)

    M. Delnavaz ، B. Ayati ، H. Ganjidoust

    2008-10-01

    Full Text Available Three moving bed biofilm reactors were used to treat synthesized wastewater of aromatic amine compounds including aniline, para-diaminobenzene and para-aminophenol that are found in many industrial wastewaters. The reactors with cylindrical shape had an internal diameter and an effective depth of 10 and 60 cm, respectively. The reactors were filled with light expanded clay aggregate as carriers and operated in an aerobic batch and continuous conditions. Evaluation of the reactors' efficiency was done at different retention time of 8, 24, 48 and 72 h with an influent COD from 100 to 3500 mg/L (filling ratio of 50%. The maximum obtained removal efficiencies were 90% (influent COD=2000 mg/L, 87% (influent COD=1000 mg/L and 75% (influent COD=750 mg/L for aniline, para-diaminobenzene and para-aminophenol, respectively. In the study of decrease in filling ratio from 50 to 30 percent, 6% decrease for both para-diaminobenzene and para-aminophenol and 7% increase for aniline degradation were obtained. The removal efficiency was decreased to about 10% after 15 days of continuous loading for each of the above three substrates. In the shock loading test, initially the COD removal rate was decreased in all reactors, but after about 10 days, it has been approached to the previous values. Finally, biodegradability of aromatic amines has been proved by nuclear magnetic resonance system.

  20. Lactoperoxidase-catalyzed activation of carcinogenic aromatic and heterocyclic amines.

    Science.gov (United States)

    Gorlewska-Roberts, Katarzyna M; Teitel, Candee H; Lay, Jackson O; Roberts, Dean W; Kadlubar, Fred F

    2004-12-01

    Lactoperoxidase, an enzyme secreted from the human mammary gland, plays a host defensive role through antimicrobial activity. It has been implicated in mutagenic and carcinogenic activation in the human mammary gland. The potential role of heterocyclic and aromatic amines in the etiology of breast cancer led us to examination of the lactoperoxidase-catalyzed activation of the most commonly studied arylamine carcinogens: 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), benzidine, 4-aminobiphenyl (ABP), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). In vitro activation was performed with lactoperoxidase (partially purified from bovine milk or human milk) in the presence of hydrogen peroxide and calf thymus DNA. Products formed during enzymatic activation were monitored by HPLC with ultraviolet and radiometric detection. Two of these products were characterized as hydrazo and azo derivatives by means of mass spectrometry. The DNA binding level of 3H- and 14C-radiolabeled amines after peroxidase-catalyzed activation was dependent on the hydrogen peroxide concentration, and the highest levels of carcinogen binding to DNA were observed at 100 microM H2O2. Carcinogen activation and the level of binding to DNA were in the order of benzidine > ABP > IQ > MeIQx > PhIP. One of the ABP adducts was identified, and the level at which it is formed was estimated to be six adducts/10(5) nucleotides. The susceptibility of aromatic and heterocyclic amines for lactoperoxidase-catalyzed activation and the binding levels of activated products to DNA suggest a potential role of lactoperoxidase-catalyzed activation of carcinogens in the etiology of breast cancer.

  1. [Present aspects and problems regarding occupational bladder cancer due to exposure to aromatic amines].

    Science.gov (United States)

    Yamamura, J

    1989-12-01

    About a century has passed since the first case of bladder cancer due to occupational exposure to carcinogenic aromatic amines was reported. In the major developed countries of the world, it is forbidden to manufacture and/or to use such aromatic amines. In Japan in the 1950's, many workers were exposed to carcinogenic aromatic amines, but in 1972, the Labor Safety and Health Act came into force and manufacturing and/or using of four kinds of aromatic amines were forbidden. Recently it has been reported that the risk of bladder cancer in workers exposed to aromatic amines before the ban of these chemicals is approximately from several times to a hundred times compared with the general population, and some reports say that dose-response relationship was observed. The important issues now are the carcinogenicity of other kinds of aromatic amines besides benzidine and 2-naphthylamine, carcinogenicity of metabolites of several substances like synthetic dyes, and carcinogenic aromatic amines as impurities in substances imported from developing countries. The type of exposure to these carcinogens changes low level and long period exposures. In addition to the chemical or dye industries, an increased risk of bladder cancer was observed among workers handling leather and rubber and those engaged in printing, textile industries, hairdressing, truck driving and so on. In the future, it will be necessary to cooperate with the departments of epidemiology, toxicology and clinical medicine for the purpose of estimating the risk of these occupations and the health care administration of the exposed workers.

  2. Synthesis, Characterization, and Pharmacological Evaluation of Selected Aromatic Amines

    Directory of Open Access Journals (Sweden)

    Hammad Ismail

    2015-01-01

    Full Text Available Aromatic amines 1-amino-4-phenoxybenzene (A-1A, 2-(4-aminophenoxy naphthalene (A-2A, and 1-(4-aminophenoxy naphthalene (A-3A were synthesized by the reduction of corresponding nitroaromatics with hydrazine monohydrate and Pd/C 5% (w/w. The newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR, UV-visible spectrophotometer, and mass spectrometry and their biological activities were investigated along with structurally similar 4-(4-aminophenyloxy biphenyl (A-A. Results of brine shrimp cytotoxicity assay showed that almost all of the compounds had LD50 values <1 μg/mL. The compounds also showed significant antitumor activity with IC50 values ranging from 67.45 to 12.2 µgmL−1. The cytotoxicity and antitumor studies correlate the results which suggests the anticancerous nature of compounds. During the interaction study of these compounds with DNA, all of the compounds showed hyperchromic effect indicating strong interaction through binding with the grooves of DNA. Moreover, A-3A also showed decrease in λmax confirming higher propensity for DNA groove binding. In DPPH free radical scavenging assay, all the compounds showed potential antioxidant capability. The compounds were highly active in protecting DNA against hydroxyl free radicals. DNA interaction and antioxidant results back up each other indicating that these compounds have potential to be used as cancer chemopreventive agents. Additionally, one compound (A-1A showed significant antibacterial and antifungal activity as well.

  3. Roles of free radicals in type 1 phototherapeutic agents: aromatic amines, sulfenamides, and sulfenates.

    Science.gov (United States)

    Lin, Tien-Sung; Rajagopalan, Raghavan; Shen, Yuefei; Park, Sungho; Poreddy, Amruta R; Asmelash, Bethel; Karwa, Amolkumar S; Taylor, John-Stephen A

    2013-07-03

    Detailed analyses of the electron spin resonance (ESR) spectra, cell viability, and DNA degradation studies are presented for the photolyzed Type I phototherapeutic agents: aromatic amines, sulfenamides, and sulfenates. The ESR studies provided evidence that copious free radicals can be generated from these N-H, N-S, and S-O containing compounds upon photoirradiation with UV/visible light. The analyses of spectral data allowed us to identify the free radical species. The cell viability studies showed that these agents after exposure to light exert cytotoxicity to kill cancer cells (U937 leukemia cell lines HTC11, KB, and HT29 cell lines) in a dosage- and time-dependent manner. We examined a possible pathway of cell death via DNA degradation by a plasmid cleavage assay for several compounds. The effects of photosensitization with benzophenone in the presence of oxygen were examined. The studies indicate that planar tricyclic amines and sulfenamides tend to form π-electron delocalized aminyl radicals, whereas nonplanar ones tend to yield nitroxide radicals resulting from the recombination of aminyl radicals with oxygen. The ESR studies coupled with the results of cell viability measurements and DNA degradation reveal that planar N-centered radicals can provide higher potency in cell death and allow us to provide some insights on the reaction mechanisms. We also found the formation of azatropylium cations possessing high aromaticity derived from azepines can facilitate secondary electron transfer to form toxic O2(•-) radicals, which can further exert oxidative stress and cause cell death.

  4. Photocatalytic oxidation of aromatic amines using MnO2@g-C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — An efficient and direct oxidation of aromatic amines to aromatic azo-compounds has been achieved using a MnO2@g-C3N4 catalyst under visible light as a source of...

  5. [Migration of monomers and primary aromatic amines from nylon products].

    Science.gov (United States)

    Mutsuga, Motoh; Yamaguchi, Miku; Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    Migration of 2 kinds of monomer and 21 kinds of primary aromatic amines (PAAs) from 21 kinds of nylon products such as turners, ladles and wrap film were determined. Samples were classified as regards materials by mean of pyrolysis-GC/MS. One sample was classified as nylon 6, 15 samples as nylon 66 and three samples as nylon 6/66 copolymers, while two samples were laminate of nylon 6 with polyethylene or polypropylene. All of the nylon 66 samples contained a small amount of ε-caprolactam (CPL), which is the nylon 6 monomer. Migration levels of monomers and PAAs at 60°C for 30 min into 20% ethanol were measured by LC/MS/MS. CPL was detected at the level of 0.015-38 µg/mL from all samples, excluding one wrap film sample, and 1,6-hexamethylenediamine was detected at the level of 0.002-0.013 µg/mL from all nylon 66 samples and one nylon 6/66 sample. In addition, 0.006-4.3 µg/mL of 4,4'-diaminodiphenylmethane from three samples, 0.032-0.23 µg/mL of aniline from four samples, 0.001 µg/mL of 4-chloroaniline from two samples, and 0.002 µg/mL of 2-toluidine and 0.066 mg/mL of 1-naphthylamine from one sample each were detected. The migration levels at 95 or 121°C were about 3 and 10 times the 60°C levels, respectively.

  6. CZE study on adsorption processes of aliphatic and aromatic amines on PMMA chip.

    Science.gov (United States)

    Masár, Marián; Kruk, Pavol; Luc, Milan; Bodor, Róbert; Danč, Ladislav; Troška, Peter

    2013-02-01

    Adsorption processes on a PMMA chip linked with CZE separations of a group of 13 aliphatic and aromatic mono- and di-amines were studied. Due to the lack of chromophores within aliphatic amines, contact conductivity detection implemented directly onto the chip was used for monitoring of cationic CZE separations. To prevent an adsorption of studied amines to the chip channels, the surface of PMMA chip was modified by dynamic coating. Different surface modifiers, such as aliphatic oligoamines (diethylenetriamine and triethylenetetramine), were added to the BGE solutions filling the chip channels. The effect of various concentrations of surface modifiers on peak profiles and separation parameters of amines was monitored. Of these, mainly, aliphatic di-amines and aromatic mono-amines adversely affected the CZE resolution of a whole group of analytes by their strong adsorption to the chip channels. A propionate BGE with pH 3.2 containing 100 μM triethylenetetramine and 25 mM 18-crown-6-ether was found suitable for CZE resolution of 12 from a total of 13 amines studied. Simple dynamic modification of the surface of PMMA chip enabled fast (analysis time lasted 9 min), sensitive (sub-μM LODs reached) and reproducible (1-3% RSD of the peak areas) CZE analysis of the aliphatic and aromatic amines.

  7. Changes in gene expression induced by aromatic amine drugs: testing the danger hypothesis.

    Science.gov (United States)

    Ng, Winnie; Uetrecht, Jack

    2013-01-01

    Virtually all drugs that contain a primary aromatic amine are associated with a high incidence of idiosyncratic drug reactions (IDRs), suggesting that this functional group has biological effects that may be used as biomarkers to predict IDR risk. Most IDRs exhibit evidence of immune involvement and the ability of aromatic amines to form reactive metabolites and redox cycle may be responsible for initiation of an immune response through induction of cell stress, as postulated by the Danger Hypothesis. If true, danger signals could be biomarkers of IDR risk. A previous attempt to test the Danger Hypothesis found that sulfamethoxazole (SMX), the only aromatic amine tested, was also the only drug not associated with an increase of cell stress genes in mice. To ensure that these observations were not species-specific, and to determine biomarkers of IDR risk common to aromatic amines, rats were treated with SMX and two other aromatic amine drugs, dapsone (DDS) and aminoglutethimide (AMG), and hepatic gene expression was determined using microarrays. As in mice, SMX induced minimal gene changes in the rat, and none indicated cell stress, whereas DDS and AMG induced several changes including up-regulation of enzymes such as aldo-keto reductase, glutathione-S-transferase, and aldehyde dehydrogenase, which may represent danger signals. Early insulin-induced hepatic gene (Eiih) was up-regulated by all three drugs. Some mRNA changes were observed in the Keap-1-Nrf2-ARE pathway; however, the pattern was significantly different for each drug. Overall, the most salient finding was that the changes in the liver were minimal, even though aromatic amines cause a high incidence of IDRs. The liver generates a large number of reactive species; however, the ability of aromatic amines to be bioactivated by cells of the immune system may be why they cause a high incidence of IDRs.

  8. Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

    Science.gov (United States)

    Pratt, J. R.

    1981-01-01

    Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

  9. Analysis of primary aromatic amines (PAA) in black nylon kitchenware 2014

    DEFF Research Database (Denmark)

    Trier, Xenia; Granby, Kit

    shall be accompanied by appropriate documentation, including analytical results showing that it meets the requirements concerning the release of primary aromatic amines. 25 samples of black nylon kitchenware each of three articles were tested for migration of primary aromatic amines (PAA), using 3......% 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...

  10. Regiospecific oxidation of an alkyl group of aromatic amine to carbonyl group by DDQ in aq.medium

    Institute of Scientific and Technical Information of China (English)

    Madhav S. Mane; Ravi S. Balaskar; Sandip N. Gavade; Pramod N. Pabrekar; Murlidhar S. Shingare; Dhananjay V. Mane

    2011-01-01

    The regiospecific oxidation of alkyl group of both sterically hindered and unhindered aromatic amine to corresponding carbonyl compound was done in aq. medium by using DDQ. The optimized reaction protocol was found to be most simple, high yielding and novel method for oxidation of alkyl group of aromatic amine in to its carbonyl compound.

  11. Light absorption and photoluminescence due to interfacial charge-transfer transitions in aromatic amine-functionalized silicon nanoparticles

    Science.gov (United States)

    Fujisawa, Jun-ichi; Hanaya, Minoru

    2017-09-01

    Aromatic amine-functionalization of silicon nanoparticles induces a new absorption band in the near UV-to-blue region and efficient blue photoluminescence even at room temperature. However, the origin of the absorption band and photoluminescence has not yet been understood well. Here, we study theoretically the electronic structure and light absorption and photoluminescence properties of carbazole-functionalized silicon nanoparticles. We reveal that the absorption band and photoluminescence are attributed to interfacial charge-transfer (ICT) transitions between the covalently-boned carbazole and silicon nanoparticles. The ICT transitions are induced by strong electronic couplings between CA and a silicon nanoparticle via the Sisbnd N bond.

  12. Primary aromatic amines (PAAs) in black nylon and other food-contact materials, 2004-2009

    DEFF Research Database (Denmark)

    Trier, Xenia Thorsager; Okholm, B.; Foverskov, Annie

    2010-01-01

    Primary aromatic amines (PAAs) were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in migrates from 234 samples of food-contact materials, including black nylon (polyamide) kitchen utensils (n = 136), coloured plastics (28), and clear/printed multilayer film/laminates (41...

  13. Ruthenium/Imidazolylphosphine catalysis: hydrogenation of aliphatic and aromatic nitriles to form amines.

    Science.gov (United States)

    Werkmeister, Svenja; Junge, Kathrin; Wendt, Bianca; Spannenberg, Anke; Jiao, Haijun; Bornschein, Christoph; Beller, Matthias

    2014-04-07

    A convenient and efficient catalyst system for the hydrogenation of aliphatic nitriles towards the corresponding primary amines in high to excellent yields is presented. In addition, aromatic nitriles are reduced smoothly, too. The use of low catalyst loadings and molecular hydrogen make this protocol an attractive methodology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Silica Chloride Nano Particle Catalyzed Ring Opening of Epoxides by Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    Karimian Ramin; Piri Farideh; Karimi Babak; Moghimi Abolghasem

    2011-01-01

    Silica chloride nano particle (nano SiO2-Cl), has been found to be heterogeneous catalyst for facile, simple and mild ring opening of epoxides with aromatic amines to afford β-amino alcohols in dry CH2Cl2 at room temperature.

  15. Cancer risk assessment of azo dyes and aromatic amines from garment and footwear

    NARCIS (Netherlands)

    Zeilmaker MJ; Kroese ED; Haperen P van; Veen MP van; Bremmer HJ; Kranen HJ van; Wouters MFA; Janus J; LBM

    1999-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals wearing garment and footwear coloured with azo dyes. Basically, the risk assessment consists of both a comparison of the (estimated) level of aromatic amines which, during the wearing of garment and footwear, enters

  16. Guidance document on fat reduction factor, functional barrier concept, phthalates and primary aromatic amines

    DEFF Research Database (Denmark)

    Hoekstra, Eddo J.; Petersen, Jens Højslev; Bustos, Juana

    and the functional barrier, and the restrictions for certain phthalates and primary aromatic amines. The Regulation applies from 1 May 2011. The network of the European Union Reference Laboratory and the National Reference Laboratories for food contact materials created a Task Force in order to give guidance...

  17. Guidance document on fat reduction factor, functional barrier concept, phthalates and primary aromatic amines

    DEFF Research Database (Denmark)

    Hoekstra, Eddo J.; Petersen, Jens Højslev; Bustos, Juana

    and the functional barrier, and the restrictions for certain phthalates and primary aromatic amines. The Regulation applies from 1 May 2011. The network of the European Union Reference Laboratory and the National Reference Laboratories for food contact materials created a Task Force in order to give guidance...

  18. Preparation of Stereodefined Homoallylic Amines from the Reductive Cross-Coupling of Allylic Alcohols with Imines

    Science.gov (United States)

    Chen, Ming Z.; McLaughlin, Martin; Takahashi, Masayuki; Tarselli, Michael A.; Yang, Dexi; Umemura, Shuhei; Micalizio, Glenn C.

    2010-01-01

    Regio-, diastereo-, and enantioselective coupling reactions between imines and allylic alcohols have been developed. These coupling reactions deliver complex homoallylic amine products through a convergent C–C bond forming process that does not proceed through intermediate allylic organometallic reagents. In general, convergent coupling, by exposure of an allylic alkoxide to a preformed Ti–imine complex, occurs with allylic transposition in a predictable and stereocontrolled manner. While simple diastereoselection in these reactions is high, delivering anti-products with ≥ 20:1 selectivity, the organometallic transformation described is compatible with a diverse range of functionality and substrates (including: aliphatic and aromatic imines, allylic silanes, trisubstituted alkenes, vinyl- and aryl halides, trifluoromethyl groups, thioethers, and aromatic heterocycles). Alkene geometry of the products is a complex function of the allylic alcohol structure, and is consistent with a mechanistic proposal based on syn-carbometalation followed by syn-elimination by way of a boat-like transition state geometry. Single asymmetric coupling reactions provide a means to translate the stereochemical information of the allylic alcohol to the homoallylic amine with very high levels of fidelity, or to control diastereoselection in the coupling reactions of achiral allylic alcohols with chiral imines. Double asymmetric coupling reactions are also described that afford a unique means to control stereoselection in these complex convergent coupling processes. Finally, empirical models are proposed that are consistent with the observed stereochemical course of these coupling reactions en route to chiral homoallylic amines possessing di- or trisubstituted alkenes, and anti- or syn- relative stereochemistry at the allylic and homoallylic positions. Overall, the bond construction enabled by this Ti-mediated reductive cross-coupling is unmatched by available methods in organic

  19. Aromatic Esters of Bicyclic Amines as Antimicrobials against Streptococcus pneumoniae.

    Science.gov (United States)

    de Gracia Retamosa, María; Díez-Martínez, Roberto; Maestro, Beatriz; García-Fernández, Esther; de Waal, Bas; Meijer, E W; García, Pedro; Sanz, Jesús M

    2015-11-09

    A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues.

  20. Removal of aromatic amines from water by montmorillonite-(cerium or zirconium) phosphate crosslinked compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Pradas, E.; Villafranca-Sanchez, M.; Urena-Amate, M.D. (Univ. of Almeria (Spain). Dept. of Inorganic Chemistry); Del Rey-Bueno, F.; Garcia-Rodriguez, A. (Univ. of Granada (Spain). Dept. of Inorganic Chemistry)

    To evaluate the potential use of two montmorillonite-(Ce or Zr) phosphate crosslinked compounds in removing organic pollutants such as aniline, p-toluidine, and p-acetylaniline from water, adsorption experiments were performed under conditions of varied temperature (288 and 308 K). Adsorption on the montmorillonite-Ce-phosphate compound was best described by a hyperbolic (H-type) isotherm, whereas for the montmorillonite-Zr-phosphate compound, S-type isotherms were obtained for p-toluidine and aniline and L-type for p-acetylaniline. Amines adsorption increases with increasing temperature on the cerium crosslinked material, while for the zirconium-crosslinked compound, adsorption decreases as temperature increases from 288 to 308 K, possibly due to a mainly physical process. Fourier-transform infrared (FTIR) spectroscopy indicated that at the pH generated by the adsorbents, the protonated species of these amines plays an important role in the adsorption process. X-ray diffraction analysis showed that the aromatic amines are intercalated into the adsorbents. For any given amine, the cerium-montmorillonite adsorbent shows a higher capacity of adsorption compared with zirconium-montmorillonite adsorbent, so it might be reasonably used in removing aromatic amines from water.

  1. Selective determination of phenols and aromatic amines based on horseradish peroxidase-nanoporous gold co-catalytic strategy.

    Science.gov (United States)

    Wu, Chao; Liu, Zhuang; Sun, Huihui; Wang, Xia; Xu, Ping

    2016-05-15

    Aromatic compounds, such as phenols and aromatic amines, are environmental contaminants suspected of posing human health risks. For phenols and aromatic amines reliable detection, promoting selectivity and sensitivity for phenols and aromatic amines is crucial in biosensor design. Here, a biosensor combined the advantages of both enzymatic and nonenzymatic electrochemical sensors is constructed. Nanoporous gold (NPG) is selected as an enzyme carrier for horseradish peroxidase (HRP) biosensor fabrication due to its three-dimension structure with unique properties. It is firstly discovered that NPG can achieve selective oxidation for phenols and aromatic amines. Thus, the electrochemical reaction on the resulting HRP/NPG/GCE bioelectrode is attributed to the co-catalysis of HRP and NPG. For the detection of catechol (Cat), 4-aminophenol (p-AP), o-phenylenediamine (o-PD), and p-phenylenediamine (p-PD), linear responses are observed in large concentration ranges with high sensitivities and low detection limits. Further, the HRP/NPG/GCE bioelectrode presents strong reproducibility, specificity, selectivity and anti-interference capability in detecting the mixture of phenols and aromatic amines along with a long shelf-life, and the real sea water sample analysis was achieved. These unique properties make the HRP/NPG/GCE bioelectrode an excellent choice for phenols and aromatic amines reliable detection.

  2. Study of catalytic effect of ammonium molybdate on the bisphthalonitrile resins curing reaction with aromatic amine

    Institute of Scientific and Technical Information of China (English)

    Wen Ting Li; Fang Zuo; Kun Jia; Xiao Bo Liu

    2009-01-01

    A kind of catalyst, ammonium molybdate was developed in this paper to promote the curing reaction of bisphthalonitrile resins with aromatic amine as curing agent, and the catalytic effect was studied by differential scanning calorimetry (DSC), rheometric measurements and thermogravimetric analysis (TGA). The results indicated that the catalyst could improve the curing rate and increase the curing degree, which could be regulated by the content of the catalyst used in the reaction.

  3. Resolution of water in crude oil emulsion by some novel aromatic amine polyesters

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2015-09-01

    Full Text Available In this work, three aromatic amines (p-toluidine, p-nitroaniline and p-chloroaniline were chosen as bases for the repatriation of some nonionic polyesters. These amines were ethoxylated with different total number of ethylene oxide units 6, 12, 18. The prepared ethoxylated amine diols were polyesterified with maleic anhydride and polypropylene oxide polyethylene oxide block copolymers in polyesterification reaction. The demulsification efficiency of these demulsifiers was investigated using the bottle test. The effects of the molecular weight, concentration, asphaltene content, water content, Hydrophile Lipophile Balance (HLB and temperature on the demulsification efficiency were investigated. The surface active properties were correlated with their demulsification efficiency. It was found that, NAE18D gave the best result in the demulsification process. The demulsification efficiency was discussed on the light of surface active properties, interfacial tension and the factors affecting the demulsification. The surface-active properties of the prepared demulsifiers were measured at 60 °C.

  4. Modification of the electronic structure in single-walled carbon nanotubes with aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Dettlaff-Weglikowska, U.; Roth, S. [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Kim, G. [Department of Physics, Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of); Bulusheva, L.G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Ac. Lavrentyev ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 K. Marx ave., Novosibirsk 630092 (Russian Federation)

    2011-11-15

    We investigated the interactions of two aromatic amines, N,N,N'N'-tetramethyl-p-phenylenediamine (TMPD) and tetramethylpyrazine (TMP) with single-walled carbon nanotube (SWNT) networks. Adsorption and intercalation of amine molecules in bundled SWNTs is expected to modify the electronic structure of nanotubes in a similar way as has already been observed for alkali metals. Our ab initio density functional calculations demonstrate that TMPD donates electron to the nanotube and produces donor-like states below the conduction band whereas the effect of the TMP treatment is very weak. The electron transfer to the nanotubes has been supported experimentally by the XPS valence band spectra which show strongly modified spectral features. Especially an increase of the electronic density at the Fermi level upon adsorption of TMPD and TMP is clearly demonstrated. Rather intensive features between {pi}* and {sigma}* transitions in the NEXAFS spectrum of the pristine SWNTs attributed to the oxidized carbon functional groups are chemically modified upon adsorption of amines on the networks. This fact suggests that the aromatic amines evidently react with the defects, remove or replace oxygen species responsible for the p-type doping of SWNTs, and therefore are acting as a de-doping agent for the naturally p-type doped semiconducting SWNTs. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. QSAR Study for Carcinogenic Potency of Aromatic Amines Based on GEP and MLPs

    Directory of Open Access Journals (Sweden)

    Fucheng Song

    2016-11-01

    Full Text Available A new analysis strategy was used to classify the carcinogenicity of aromatic amines. The physical-chemical parameters are closely related to the carcinogenicity of compounds. Quantitative structure activity relationship (QSAR is a method of predicting the carcinogenicity of aromatic amine, which can reveal the relationship between carcinogenicity and physical-chemical parameters. This study accessed gene expression programming by APS software, the multilayer perceptrons by Weka software to predict the carcinogenicity of aromatic amines, respectively. All these methods relied on molecular descriptors calculated by CODESSA software and eight molecular descriptors were selected to build function equations. As a remarkable result, the accuracy of gene expression programming in training and test sets are 0.92 and 0.82, the accuracy of multilayer perceptrons in training and test sets are 0.84 and 0.74 respectively. The precision of the gene expression programming is obviously superior to multilayer perceptrons both in training set and test set. The QSAR application in the identification of carcinogenic compounds is a high efficiency method.

  6. QSAR Study for Carcinogenic Potency of Aromatic Amines Based on GEP and MLPs

    Science.gov (United States)

    Song, Fucheng; Zhang, Anling; Liang, Hui; Cui, Lianhua; Li, Wenlian; Si, Hongzong; Duan, Yunbo; Zhai, Honglin

    2016-01-01

    A new analysis strategy was used to classify the carcinogenicity of aromatic amines. The physical-chemical parameters are closely related to the carcinogenicity of compounds. Quantitative structure activity relationship (QSAR) is a method of predicting the carcinogenicity of aromatic amine, which can reveal the relationship between carcinogenicity and physical-chemical parameters. This study accessed gene expression programming by APS software, the multilayer perceptrons by Weka software to predict the carcinogenicity of aromatic amines, respectively. All these methods relied on molecular descriptors calculated by CODESSA software and eight molecular descriptors were selected to build function equations. As a remarkable result, the accuracy of gene expression programming in training and test sets are 0.92 and 0.82, the accuracy of multilayer perceptrons in training and test sets are 0.84 and 0.74 respectively. The precision of the gene expression programming is obviously superior to multilayer perceptrons both in training set and test set. The QSAR application in the identification of carcinogenic compounds is a high efficiency method. PMID:27854309

  7. Occurrence of aromatic amines and N-nitrosamines in the different steps of a drinking water treatment plant.

    Science.gov (United States)

    Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

    2012-09-15

    The occurrence of 24 amines within a full scale drinking water treatment plant that used chlorinated agents as disinfectants was evaluated for the first time in this research. Prior to any treatment (raw water), aniline, 3-chloroaniline, 3,4-dichloroaniline and N-nitrosodimethylamine were detected at low levels (up to 18 ng/L) but their concentration increased ∼10 times after chloramination while 9 new amines were produced (4 aromatic amines and 5 N-nitrosamines). Within subsequent treatments, there were no significant changes in the amine levels, although the concentrations of 2-nitroaniline, N-nitrosodimethylamine and N-nitrosodiethylamine increased slightly within the distribution system. Eleven of the 24 amines studied were undetected either in the raw and in the treatment plant samples analysed. There is an important difference in the behaviour of the aromatic amines and N-nitrosamines with respect to water temperature and rainfall events. Amine concentrations were higher in winter due to low water temperatures, this effect being more noticeable for N-nitrosamines. Aromatic amines were detected at their highest concentrations (especially 3,4-dichloroaniline and 2-nitroaniline) in treated water after rainfall events. These results may be explained by the increase in the levels of amine precursors (pesticides and their degradation products) in raw water since the rainfall facilitated the transport of these compounds from soil which was previously contaminated as a result of intensive agricultural practices.

  8. Determination of Aromatic Amines in Cigarette Mainstream Smoke - The CORESTA 2007 Joint Experiment

    Directory of Open Access Journals (Sweden)

    Intorp M

    2014-12-01

    Full Text Available CORESTA joint experiment work in 2006 had compared data on a wide range of smoke constituents obtained from Kentucky reference cigarettes (1R5F and 2R4F, according to the existing methods used by participants. This work had identified that the methods used to determine aromatic amine yields in mainstream smoke would particularly benefit from further study to investigate the main weaknesses and influencing factors in their yield variability before progressing to full method standardisation. This report describes the output from a 2007 joint experiment to address these issues. Participating laboratories carried out experiments to investigate several factors that had been identified in the methodology as potential sources of variability. These were the amine derivative type, the derivatisation time and the point at which the addition of the internal standard for calibration occurred. A statistical assessment was made of their possible influence on aromatic amine smoke yields and yield reproducibility across different laboratories. Results showed that aromatic amines again had poor between-laboratory yield reproducibility. The stage at which the internal standard was added to the smoke sample had the most significant effect on yields. The least variable data were obtained when it was added directly after extraction from the filter pad rather than later in the process. It also appeared beneficial to use at least two calibration standards (i.e., an aminonaphthalene and an aminobiphenyl to minimise yield differences although this recommendation was not supported by statistically significant data. Large differences in yields were not found when comparing the two studied derivatising agents especially when compared against the greater overall between-laboratory variability. Any differences between laboratories in total particulate matter and puff count at the smoke collection stage did not appear to significantly contribute to betweenlaboratory

  9. Efficient and Selective Reduction of Aromatic Nitro Compounds to Aromatic Amines by NbCl{sub 5}/Indium System

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byung Woo; Kim, Duckil; Kim, Hyung Min; Kang, Sung Ho [Korea Univ., Seoul (Korea, Republic of)

    2012-09-15

    Aromatic amines find applicability in diverse fields including dyes, pharmaceuticals, agrochemicals, and photographic materials. To date, there are a variety of methods, which can be used to convert aromatic nitro compounds to their corresponding amines. Some of them include Cp{sub 2}TiCl{sub 2}/In, Al/NH{sub 4}Cl, (NH{sub 4}){sub 2}SO{sub 4}/NaBH{sub 4}, NiCl{sub 2}6H{sub 2}O/In, HI, Sm/I{sub 2}, In/NH{sub 4}Cl, B{sub 4}H{sub 10}/Pd/C, Co{sub 2}(CO){sub 8}/H{sub 2}O and In/HCl. However, most methods still lack the desired chemo-selectivity when other reducible functional groups are present in the nitroarene and often require long reaction times, or harsh reaction conditions. Consequently, efficient and selective methods for the reduction of aromatic nitro compounds continue to be developed. It has been reported that NbCl{sub 5}/Zn system is used as a reagent for reducing sulfoxides, epoxides, and amine N-oxides.12 Because of the close resemblance of indium to zinc in several respects, including first ionization potential, we considered that NbCl{sub 5}/In system can be an efficient reducing agent for the conversion of aromatic nitro compounds to the corresponding amines. Recently, indium metal has attracted much attention for its unique properties such as low toxicity and high stability in water and air compared with other metals. In continuation of our interest in exploring the utility of metal-metal salt system in organic synthesis, we would like to report an efficient and chemo-selective method for the reduction of various aromatic nitro compounds to the corresponding amines by treatment with NbCl{sub 5}/In system (eq. 1). The new reduction system was generated by the addition of indium powder to a stirred solution of niobium(V) chloride in THF under sonication. The generation of low-valent niobium species was examined at room temperature with an excess of indium metal. The observations suggest that this procedure can be applied for the chemo

  10. Anomalous length dependence of conductance of aromatic nanoribbons with amine anchoring groups

    KAUST Repository

    Bilić, Ante

    2012-09-06

    Two sets of aromatic nanoribbons, based around a common hexagonal scaffolding, with single and dual terminal amine groups have been considered as potential molecular wires in a junction formed by gold leads. Charge transport through the two-terminal device has been modeled using density functional theory (with and without self-interaction correction) and the nonequilibrium Green\\'s function method. The effects of wire length, multiple terminal contacts, and pathways across the junction have been investigated. For nanoribbons with the oligopyrene motif and conventional single amine terminal groups, an increase in the wire length causes an exponential drop in the conductance. In contrast, for the nanoribbons with the oligoperylene motif and dual amine anchoring groups the predicted conductance rises with the wire length over the whole range of investigated lengths. Only when the effects of self-interaction correction are taken into account, the conductance of the oligoperylene ribbons exhibits saturation for longer members of the series. The oligoperylene nanoribbons, with dual amine groups at both terminals, show the potential to fully harness the highly conjugated system of π molecular orbitals across the junction. © 2012 American Physical Society.

  11. Adsorption and Oxidation of Aromatic Amines on Metal(II Hexacyanocobaltate(III Complexes: Implication for Oligomerization of Exotic Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Rachana Sharma

    2017-03-01

    Full Text Available Based on the hypothesis on the presence of double metal cyanides in the primordial oceans, a series of nano-sized metal(II hexacyanocobaltate(III (MHCCo with the general formula: M3[Co(CN6]2•xH2O (where M = Zn, Fe, Ni and Mn has been synthesized. Surface interaction of aromatic amines, namely aniline, 4-chloroaniline, 4-methylaniline and 4-methoxyaniline with MHCCo particles has been carried out at the concentration range of 100–400 μM at pH~7.0. The percentage binding of aromatic amines on MHCCo surface was found to be in the range of 84%–44%. The trend in adsorption was in accordance to the relative basicity of the studied amines. At the experimental pH, amines reacted rapidly with the surface of the iron(II hexacyanocobaltate, producing colored products that were analyzed by Gas Chromatography Mass Spectroscopy (GC-MS. GC-MS analysis of the colored products demonstrated the formation of dimers of the studied aromatic amines. Surface interaction of aromatic amines with MHCCo was studied by Fourier Transform Infrared (FT-IR spectroscopy and Field Emission Scanning Electron Microscopy (FE-SEM. The change in amine characteristic frequencies, as observed by FT-IR, suggests that interaction took place through the NH2 group on amines with metal ions of hexacyanocobaltate complexes. FE-SEM studies revealed the adherence of 4-methoxyaniline on zinc hexacyanocobaltate particles surface. We proposed that MHCCo might have been formed under the conditions on primitive Earth and may be regarded as an important candidate for concentrating organic molecules through the adsorption process.

  12. Development and validation of a hydrophilic interaction liquid chromatographic method for determination of aromatic amines in environmental water.

    Science.gov (United States)

    Li, Ruiping; Zhang, Yi; Lee, Charles C; Lu, Rongrong; Huang, Yingping

    2010-03-12

    A simple, precise, and accurate hydrophilic interaction liquid chromatographic (HILIC) method has been developed for the determination of five aromatic amines in environmental water samples. Chromatography was carried out on a bare silica column, using a mixture of acetonitrile and a buffer of NaH(2)PO(4)-H(3)PO(4) (pH 1.5, containing 10mM NaH(2)PO(4)) (85:15, v/v) as a mobile phase at a flow rate of 1 mL min(-1). Aromatic amines were detected by UV absorbance at 254 nm. The linear range of amines was good (r(2)>0.998) and limit of detection (LOD) within 0.02-0.2 mg L(-1) (S/N=3). The retention mechanism for the analytes under the optimum conditions was determined to be a combination of adsorption, partition and ionic interactions. The proposed method was applied to the environmental water samples. Aromatic amines were isolated from aqueous samples using solid-phase extraction (SPE) with Oasis HLB cartridges. Recoveries of greater than 75% with precision (RSD) less than 12% were obtained at amine concentrations of 5-50 microg L(-1) from 100mL river water and influents from a wastewater treatment plant (WWTP). The present HILIC technique proved to be a viable method for the analysis of aromatic amines in the environmental water samples.

  13. Antimutagenicity of coriander (Coriandrum sativum) juice on the mutagenesis produced by plant metabolites of aromatic amines.

    Science.gov (United States)

    Cortés-Eslava, Josefina; Gómez-Arroyo, Sandra; Villalobos-Pietrini, Rafael; Espinosa-Aguirre, Jesús Javier

    2004-11-02

    Aromatic amines are metabolically activated into mutagenic compounds by both animal and plant systems. The 4-nitro-o-phenylenediamine (NOP) is a well-known direct-acting mutagen whose mutagenic potential can be enhanced by plant metabolism; m-phenylenediamine (m-PDA) is converted to mutagenic products detected by the Salmonella typhimurium TA98 strain, and 2-aminofluorene (2-AF) is the plant-activated promutagen most extensively studied. Plant cells activate both 2-AF and m-PDA into potent mutagens producing DNA frameshift mutations. Coriander (Coriandrum sativum) is a common plant included in the Mexican diet, usually consumed uncooked. The antimutagenic activity of coriander juice against the mutagenic activity of 4-nitro-o-phenylenediamine, m-phenylenediamine and 2-aminofluorene was investigated using the Ames reversion mutagenicity assay (his- to his+) with the S. typhimurium TA98 strain as indicator organism. The plant cell/microbe coincubation assay was used as the activating system for aromatic transformation and plant extract interaction. Aqueous crude coriander juice significantly decreased the mutagenicity of metabolized aromatic amines (AA) in the following order: 2-AF (92.43%) > m-PDA (87.14%) > NOP (83.21%). The chlorophyll content in vegetable juice was monitored and its concentration showed a positive correlation with the detected antimutagenic effect. Protein content and peroxidase activity were also determined. The concentration of coriander juice (50-1000 microl/coincubation flask) was neither toxic nor mutagenic. The similar shape of the antimutagenic response curves obtained with coriander juice and chlorophyllin (used as a subrogate molecule of chlorophyll) indicated that comparable mechanisms of mutagenic inhibition could be involved. The negative correlation between chlorophyll content and mutagenic response of the promutagenic and direct-acting used amines allows us to deduce that a chemical interaction takes place between the two molecules

  14. Curing Reaction Kinetics of Epoxy Resin Using Dicyandiamide Modified by Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    CHEN Lianxi; TIAN Hua; LIU Quanwen; Wang Jun

    2007-01-01

    The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry (DSC). The results showed that the modified dicyandiamide had better curing characteristic than ummodified dicyandiamide for epoxy resin E-44, and the curing reaction could be carried out at moderate temperature. Apparent activation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mechanism also was discussed.

  15. Extraction and Spectrophotometric Determination of Molybdenum with o-Hydroxythiophenols and Aromatic Amines

    OpenAIRE

    A. Z. Zalov; N. A. Verdizade; A. B. Hadjieva

    2015-01-01

    The interaction of molybdenum (VI) with o-hydroxythiophenol derivatives (HTPDs) and aromatic amines (AAs) was studied. The following three HTPDs, which contain different halogen atoms at position 5, were used: 2-hydroxy-5-chlorothiophenol(HCTP), 2-hydroxy-5-bromothiophenol (HBTP), 2-hydroxy-5-iodothiophenol (HITP)]. The examined AAs were aniline (An), N-methylaniline (mAn) and N,N-dimethylaniline (dAn). The obtained ternary complexes have a composition of 1:2:2 {Mo(V):HBTP:AA}.Optimal conditi...

  16. Solvent-free functionalization of fullerene C{sub 60} and pristine multi-walled carbon nanotubes with aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Calera, Itzel J. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico); Meza-Laguna, Victor [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Gromovoy, Taras Yu. [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of the Ukraine, Gen. Naumova 17, 03164 Kiev (Ukraine); Chávez-Uribe, Ma. Isabel [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Vladimir A., E-mail: basiuk@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Elena V., E-mail: elbg1111@gmail.com [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico)

    2015-02-15

    Highlights: • Pristine multi-walled carbon nanotubes were functionalized with aromatic amines. • The amines add onto nanotube defects, likewise they add onto fullerene C{sub 60}. • The addition takes place at elevated temperature and without organic solvents. • Functionalized nanotubes were characterized by a number of instrumental techniques. - Abstract: We employed a direct one-step solvent-free covalent functionalization of solid fullerene C{sub 60} and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180–250 °C, during relatively short time of about 2 h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, {sup 13}C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C{sub 60} molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C{sub 60}, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.

  17. Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

    Directory of Open Access Journals (Sweden)

    Riccardo Porta

    2016-12-01

    Full Text Available The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully performed for the first time under continuous-flow conditions. Aromatic as well as aliphatic nitro derivatives were converted to the corresponding primary amines in high yields and very short reaction times with no need for purification. The methodology was also extended to the synthesis of two synthetically relevant intermediates (precursors of baclofen and boscalid.

  18. Aromatic amine degradation in a UASB/CSTR sequential system treating Congo Red dye.

    Science.gov (United States)

    Işik, Mustafa; Sponza, Delia Teresa

    2003-01-01

    In this study an anaerobic (upflow anaerobic sludge blanket reactor)/aerobic (completely stirred tank reactor) sequential system was used to treat a synthetic wastewater with minerals and co-substrate together with 100-4000 mg L(-1) of Congo Red dye (Direct red 28) (CR), which is a banned azo dye in Turkey. The effect of hydraulic retention time (HRT) on the decolorization and the COD removal efficiency was investigated at constant 100 mg L(-1) Congo Red concentration. 77% of COD and 95% of color was removed at a HRT of 0.486 days and a maximum organic loading rate of 6.656 kg COD m(-3) day(-1) in the anaerobic/aerobic stage. In the continuous operations, 88% of COD, 99% of color and 91% of total aromatic amine (TAA) were removed at a HRT of 3.60 days and at a CR concentration of 4000 mg L(-1). This corresponds to an organic loading rate of 1.81 kg COD m(-3) day(-1), and a CR dye loading rate of 46.37 g dye m(-3) h(-1), respectively, in the whole system. The TAA produced under anaerobic conditions was ultimately removed in the aerobic stage, resulting in very low aromatic amine recoveries (5-18%) in the last one. Therefore the aerobic effluents exhibited higher IC50 and specific methanogenic activities (SMA) compared to anaerobic and dye containing samples, indicating the reduced toxicity.

  19. Solvent-free functionalization of fullerene C60 and pristine multi-walled carbon nanotubes with aromatic amines

    Science.gov (United States)

    Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Gromovoy, Taras Yu.; Chávez-Uribe, Ma. Isabel; Basiuk, Vladimir A.; Basiuk, Elena V.

    2015-02-01

    We employed a direct one-step solvent-free covalent functionalization of solid fullerene C60 and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180-250 °C, during relatively short time of about 2 h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, 13C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C60 molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C60, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.

  20. The repertoire of trace amine G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Gloriam, David E.; Bjarnadóttir, Thóra K; Yan, Yi-Lin

    2005-01-01

    Trace amines, such as tyramine, beta-phenylethylamine, tryptamine, and octopamine, are present in trace levels in nervous systems and bind a specific family of G-protein-coupled receptors (GPCR), but the function or origin of this system is not well understood. We searched the genomes of several...... ancestor of vertebrate TA-receptors arose before the split of the ray-finned and lobe-finned fishes. The evolutionary history of the TA-receptors is more complex than for most other GPCR families and here we suggest a mechanism by which they may have arisen....

  1. Formation of a carcinogenic aromatic amine from an azo dye by human skin bacteria in vitro.

    Science.gov (United States)

    Platzek, T; Lang, C; Grohmann, G; Gi, U S; Baltes, W

    1999-09-01

    Azo dyes represent the major class of dyestuffs. They are metabolised to the corresponding amines by liver enzymes and the intestinal microflora following incorporation by both experimental animals and humans. For safety evaluation of the dermal exposure of consumers to azo dyes from wearing coloured textiles, a possible cleavage of azo dyes by the skin microflora should be considered since, in contrast to many dyes, aromatic amines are easily absorbed by the skin. A method for measuring the ability of human skin flora to reduce azo dyes was established. In a standard experiment, 3x10(11) cells of a culture of Staphylococcus aureus were incubated in synthetic sweat (pH 6.8, final volume 20 mL) at 28 degrees C for 24 h with Direct Blue 14 (C.I. 23850, DB 14). The reaction products were extracted and analysed using HPLC. The reduction product o-tolidine (3,3'-dimethylbenzidine, OT) could indeed be detected showing that the strain used was able to metabolise DB 14 to the corresponding aromatic amine. In addition to OT, two further metabolites of DB 14 were detected. Using mass spectrometry they were identified as 3,3'-dimethyl-4-amino-4'-hydroxybiphenyl and 3, 3'-dimethyl-4-aminobiphenyl. The ability to cleave azo dyes seems to be widely distributed among human skin bacteria, as, under these in vitro conditions, bacteria isolated from healthy human skin and human skin bacteria from strain collections also exhibited azo reductase activity. Further studies are in progress in order to include additional azo dyes and coloured textiles. At the moment, the meaning of the results with regard to consumer health cannot be finally assessed.

  2. Preparation of Sulphur-containing Aromatic Amines by Reduction of the Corresponding Aromatic Nitro Compounds with Hydrazine Hydrate over Iron Oxide Hydroxide Catalyst

    Institute of Scientific and Technical Information of China (English)

    Qi Xun SHI; Rong Wen LU; Zhu Xia ZHANG; De Feng ZHAO

    2006-01-01

    Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.

  3. Identification of non-regulated aromatic amines of toxicological concern which can be cleaved from azo dyes used in clothing textiles.

    Science.gov (United States)

    Brüschweiler, Beat J; Küng, Simon; Bürgi, Daniel; Muralt, Lorenz; Nyfeler, Erich

    2014-07-01

    Azo dyes in textiles may release aromatic amines after enzymatic cleavage by skin bacteria or after dermal absorption and metabolism in the human body. From the 896 azo dyes with known chemical structure in the available textile dyes database, 426 azo dyes (48%) can generate one or more of the 22 regulated aromatic amines in the European Union in Annex XVII of REACH. Another 470 azo dyes (52%) can be cleaved into exclusively non-regulated aromatic amines. In this study, a search for publicly available toxicity data on non-regulated aromatic amines was performed. For a considerable percentage of non-regulated aromatic amines, the toxicity database was found to be insufficient or non-existent. 62 non-regulated aromatic amines with available toxicity data were prioritized by expert judgment with objective criteria according to their potential for carcinogenicity, genotoxicity, and/or skin sensitization. To investigate the occurrence of azo dye cleavage products, 153 random samples of clothing textiles were taken from Swiss retail outlets and analyzed for 22 high priority non-regulated aromatic amines of toxicological concern. Eight of these 22 non-regulated aromatic amines of concern could be detected in 17% of the textile samples. In 9% of the samples, one or more of the aromatic amines of concern could be detected in concentrations >30 mg/kg, in 8% of the samples between 5 and 30 mg/kg. The highest measured concentration was 622 mg/kg textile. There is an obvious need to assess consumer health risks for these non-regulated aromatic amines and to fill this gap in the regulation of clothing textiles.

  4. Cancer mortality and occupational exposure to aromatic amines and inhalable aerosols in rubber tire manufacturing in Poland.

    NARCIS (Netherlands)

    de Vocht, F.; Sobala, W.; Wilczynska, U.; Kromhout, H.; Szeszenia-Dabrowska, N.; Peplonska, B.

    2009-01-01

    AIM: Most data on carcinogenic risk in the rubber industry are based on data from Western countries. This study assessed cancer risks in a retrospective cohort in a Polish tire manufacturing plant, relying on quantified exposure to inhalable aerosols and aromatic amines instead of job titles or exte

  5. Determination of polar aromatic amines using newly synthesized sol-gel titanium (IV) butoxide cyanopropyltriethoxysilane as solid phase extraction sorbent.

    Science.gov (United States)

    Miskam, Mazidatulakmam; Abu Bakar, Nor Kartini; Mohamad, Sharifah

    2014-03-01

    A solid phase extraction (SPE) method has been developed using a newly synthesized titanium (IV) butoxide-cyanopropyltriethoxysilane (Ti-CNPrTEOS) sorbent for polar selective extraction of aromatic amines in river water sample. The effect of different parameters on the extraction recovery was studied using the SPE method. The applicability of the sorbents for the extraction of polar aromatic amines by the SPE was extensively studied and evaluated as a function of pH, conditioning solvent, sample loading volume, elution solvent and elution solvent volume. The optimum experimental conditions were sample at pH 7, dichloromethane as conditioning solvent, 10 mL sample loading volume and 5 mL of acetonitrile as the eluting solvent. Under the optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) for solid phase extraction using Ti-CNPrTEOS SPE sorbent (0.01-0.2; 0.03-0.61 µg L(-1)) were lower compared with those achieved using Si-CN SPE sorbent (0.25-1.50; 1.96-3.59 µg L(-1)) and C18 SPE sorbent (0.37-0.98; 1.87-2.87 µg L(-1)) with higher selectivity towards the extraction of polar aromatic amines. The optimized procedure was successfully applied for the solid phase extraction method of selected aromatic amines in river water, waste water and tap water samples prior to the gas chromatography-flame ionization detector separation.

  6. Content of heterocyclic amines and polycyclic aromatic hydrocarbons in pork, beef and chicken barbecued at home by Danish consumers

    DEFF Research Database (Denmark)

    Aaslyng, Margit D.; Duedahl-Olesen, Lene; Jensen, Kirsten;

    2013-01-01

    It is a well-known fact that, when meat is barbecued, several harmful components, including heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH), may be formed. The aim of this study was to determine the HCA and PAH content in meat (pork, chicken and beef) when barbecued at home...

  7. Oxidative Carbonylation of Aromatic Amines with CO Catalyzed by 1,3-Dialkylimidazole-2-selenone in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Fengshou Tian

    2015-01-01

    Full Text Available 1,3-Dialkylimidazole-2-selenone as a novel substituted selenium heterocyclic catalyst was used to catalyze oxidative carbonylation of aromatic amines with carbon monoxide in the presence of air to symmetrical ureas in up to 97% yield in ionic liquids.

  8. Selective Release of Aromatic Heterocycles from Ruthenium Tris(2-pyridylmethyl)amine with Visible Light.

    Science.gov (United States)

    Li, Ao; White, Jessica K; Arora, Karan; Herroon, Mackenzie K; Martin, Philip D; Schlegel, H Bernhard; Podgorski, Izabela; Turro, Claudia; Kodanko, Jeremy J

    2016-01-04

    Three complexes of the general formula [Ru(TPA)L2](PF6)2 [TPA = tris(2-pyridylmethyl)amine], where L = pyridine (1), nicotinamide (2), and imidazole (3), were prepared and characterized spectroscopically. X-ray crystallographic data were obtained for 1 and 3. Complexes 1-3 show strong absorption in the visible region and selective release of heterocycles upon irradiation with visible light. Time-dependent density functional theory calculations are consistent with the presence of singlet metal-to-ligand charge-transfer bands in the visible region in 1-3. Caged heterocycles 1-3 are highly stable in solution in the dark, including in cell growth media. Cell viability data show no signs of toxicity of 1-3 against PC-3 cells at concentrations up to 100 μM under light and dark conditions, consistent with Ru(TPA) acting as a nontoxic and effective photocaging group for aromatic heterocycles.

  9. The biochemical mechanisms of the plant activation of promutagenic aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, E.D.; Verdier, M.M.; Plewa, M.J. (Univ. of Illinois, Urbana (USA))

    1990-01-01

    Using specific monooxygenase and oxidase inhibitors in a plant cell/microbe coincubation assay, the biochemical mechanisms of the plant activation of two aromatic amines were compared. The biological endpoints included mutation induction, inhibition of mutagenicity, viability of the plant cells (activating system), and viability of the microbial cells. The activation of m-phenylenediamine by TX1 cells was mediated by enzyme systems that were inhibited by diethyldithiocarbamate, potassium cyanide, methimazole, (+)-catechin or acetaminophen. The inhibition by metyrapone was attended by toxicity in the plant cells. These data implicate a TX1 cell peroxidase and a FAD-dependent monoxygenase in the plant activation of m-phenylenediamine. The TX1 cell activation of 2-aminofluorene was inhibited by diethyldithiocarbamate, 7,8-benzoflavone, acetaminophen or (+)-catechin.

  10. Study of interaction and adsorption of aromatic amines by manganese oxides and their role in chemical evolution

    Science.gov (United States)

    Bhushan, Brij; Nayak, Arunima; Kamaluddin

    2017-04-01

    The role of manganese oxides in concentrating organic moieties and offering catalytic activity for prebiotic reactions is investigated by studying their interaction with different aromatic amines such as aniline, p-chloroaniline, p-toluidine and p-anisidine. For all amines, metal oxides showed highest adsorption at neutral pH. The order of their adsorption capacity and affinity as revealed by the Langmuir constants was found to be manganosite (MnO) > bixbyite (Mn2O3) > hausmannite (Mn3O4) > and pyrolusite (MnO2). At alkaline pH, these manganese oxides offered their surfaces for oxidation of amines to form coloured oligomers. Analysis of the oxidation products by gas chromatography-mass spectrometry showed the formation of a dimer from p-anisidine and p-chloroaniline, while a trimer and tetramer is formed from p-toluidine and aniline, respectively. A reaction mechanism is proposed for the formation of the oligomers. While field-emission scanning electron microscopic studies confirm the binding phenomenon, the Fourier transform infrared spectroscopy analysis suggests that the mechanism of binding of amines on the manganese oxides was primarily electrostatic. The adsorption behaviour of the studied aromatic amines followed the order: p-anisidine > p-toluidine > aniline > p-chloroaniline, which is related to the basicities and structure of the amines. Our studies confirmed the significance of the role of manganese oxides in prebiotic chemistry.

  11. The enhanced bladder cancer susceptibility of NAT2 slow acetylators towards aromatic amines: a review considering ethnic differences.

    Science.gov (United States)

    Golka, Klaus; Prior, Verena; Blaszkewicz, Meinolf; Bolt, Hermann M

    2002-03-10

    Human bladder cancer may be caused by exposure to aromatic amines. The polymorphic enzyme N-acetyltransferase 2 (NAT2) is involved in the metabolism of these compounds. Two classical studies on chemical workers in Europe, exposed in the past to aromatic amines like benzidine, unambiguously showed that the slow acetylator status is a genetic risk factor for arylamine-induced bladder cancer. In the former benzidine industry in Huddington, Great Britain, 22 of 23 exposed cases with bladder cancer, but only 57% of 95 local controls without bladder cancer were of the slow acetylator phenotype. In Leverkusen, Germany, 82% of 92 benzidine-exposed chemical workers with bladder cancer were of the slow acetylator phenotype, whereas only 48% of 331 chemical workers who had worked at that plant were of the slow acetylator phenotype. This is in line with several smaller studies, which also show an over-representation of the slow acetylator status in formerly arylamine-exposed subjects with bladder cancer. Some of these studies included also subjects that were exposed to aromatic amines by having applied dyes, paints and varnishes. These European findings are in contrast to a large study on Chinese workers occupationally exposed to aromatic amines. In this study, only five of 38 bladder cancer cases occupationally exposed to arylamines were of the slow acetylator genotype. This is much lower than the ratio of slow acetylators to the general population in China. This points to different mechanisms of susceptibility for bladder cancer upon exposure to aromatic amines between European (Caucasian) and Chinese populations.

  12. amines

    Directory of Open Access Journals (Sweden)

    Styszko Katarzyna

    2017-01-01

    Full Text Available The study investigated the application of char activated with CO2 and impregnated with amines solutions for removal of selected xenobiotics from aqueous solutions. The chars produced from the pyrolysis of waste tires. The solutions of monoethanolamine (MEA, diethanolamine (DEA and polyethylenimine (PEI were used for impregnation of char. The sorption capacity of char impregnated with amines depended on amines chemical properties. The adsorptive removal of mixture of pharmaceuticals residues by modified materials was assessed. BET surface area of materials varied from 36 m2 g−1 to 128 m2 g−1. The highest removal efficiencies up to 99 % were observed for char impregnated with PEI.

  13. Amine synthesis via iron-catalysed reductive coupling of nitroarenes with alkyl halides

    Science.gov (United States)

    Cheung, Chi Wai; Hu, Xile

    2016-08-01

    (Hetero)Aryl amines, an important class of organic molecules in medicinal chemistry, are most commonly synthesized from anilines, which are in turn synthesized by hydrogenation of nitroarenes. Amine synthesis directly from nitroarenes is attractive due to improved step economy and functional group compatibility. Despite these potential advantages, there is yet no general method for the synthesis of (hetero)aryl amines by carbon-nitrogen cross-coupling of nitroarenes. Here we report the reductive coupling of nitroarenes with alkyl halides to yield (hetero)aryl amines. A simple iron catalyst enables the coupling with numerous primary, secondary and tertiary alkyl halides. Broad scope and high functional group tolerance are demonstrated. Mechanistic study suggests that nitrosoarenes and alkyl radicals are involved as intermediates. This new C-N coupling method provides general and step-economical access to aryl amines.

  14. Isolation and identification of a novel aromatic amine mutagen produced by the Maillard reaction.

    Science.gov (United States)

    Nishigaki, Rena; Watanabe, Tetsushi; Kajimoto, Tetsuya; Tada, Atsuko; Takamura-Enya, Takeji; Enomoto, Shigeki; Nukaya, Haruo; Terao, Yoshiyasu; Muroyama, Atsushi; Ozeki, Minoru; Node, Manabu; Hasei, Tomohiro; Totsuka, Yukari; Wakabayashi, Keiji

    2009-09-01

    To clarify the formation of mutagens in the Maillard reaction of glucose and amino acids, 20 amino acids were separately incubated with glucose in the presence or absence of hydroxyl radicals produced by the Fenton reaction. After 1 week at 37 degrees C and pH 7.4, the reaction mixtures of glucose and tryptophan with and without the Fenton reagent showed mutagenicity toward Salmonella typhimurium YG1024 in the presence of a mammalian metabolic system (S9 mix). To identify mutagens in the reaction mixture, blue rayon-adsorbed material from a mixture of glucose, tryptophan, and the Fenton reagent was separated by column chromatography using various solid and mobile phases, and one mutagen, which accounted for 18% of the total mutagenicity of the reaction mixture, was isolated. The chemical structure of the mutagen was determined to be 5-amino-6-hydroxy-8H-benzo[6,7]azepino[5,4,3-de]quinolin-7-one (ABAQ) on the basis of ESI mass, high-resolution APCI mass, (1)H NMR, (13)C NMR, and IR spectral analyses and chemical synthesis of the mutagen. The novel aromatic amine showed high mutagenicity toward S. typhimurium TA98 and YG1024 with S9 mix, inducing 857 revertants of TA98 and 6007 revertants of YG1024/microg, respectively. The mutagenicity of ABAQ was comparable to that of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, which is a mutagenic and carcinogenic hetrocyclic amine in cooked meat and fish formed through the Maillard reaction at high temperature.

  15. Theoretical studies of chemical reactivity of metabolically activated forms of aromatic amines toward DNA.

    Science.gov (United States)

    Shamovsky, Igor; Ripa, Lena; Blomberg, Niklas; Eriksson, Leif A; Hansen, Peter; Mee, Christine; Tyrchan, Christian; O'Donovan, Mike; Sjö, Peter

    2012-10-15

    The metabolism of aromatic and heteroaromatic amines (ArNH₂) results in nitrenium ions (ArNH⁺) that modify nucleobases of DNA, primarily deoxyguanosine (dG), by forming dG-C8 adducts. The activated amine nitrogen in ArNH⁺ reacts with the C8 of dG, which gives rise to mutations in DNA. For the most mutagenic ArNH₂, including the majority of known genotoxic carcinogens, the stability of ArNH⁺ is of intermediate magnitude. To understand the origin of this observation as well as the specificity of reactions of ArNH⁺ with guanines in DNA, we investigated the chemical reactivity of the metabolically activated forms of ArNH₂, that is, ArNHOH and ArNHOAc, toward 9-methylguanine by DFT calculations. The chemical reactivity of these forms is determined by the rate constants of two consecutive reactions leading to cationic guanine intermediates. The formation of ArNH⁺ accelerates with resonance stabilization of ArNH⁺, whereas the formed ArNH⁺ reacts with guanine derivatives with the constant diffusion-limited rate until the reaction slows down when ArNH⁺ is about 20 kcal/mol more stable than PhNH⁺. At this point, ArNHOH and ArNHOAc show maximum reactivity. The lowest activation energy of the reaction of ArNH⁺ with 9-methylguanine corresponds to the charge-transfer π-stacked transition state (π-TS) that leads to the direct formation of the C8 intermediate. The predicted activation barriers of this reaction match the observed absolute rate constants for a number of ArNH⁺. We demonstrate that the mutagenic potency of ArNH₂ correlates with the rate of formation and the chemical reactivity of the metabolically activated forms toward the C8 atom of dG. On the basis of geometric consideration of the π-TS complex made of genotoxic compounds with long aromatic systems, we propose that precovalent intercalation in DNA is not an essential step in the genotoxicity pathway of ArNH₂. The mechanism-based reasoning suggests rational design strategies to

  16. Evaluation of Uncertainty for Detecting the Content of Banned Aromatic Amines in Textile Products by GC-MS

    Institute of Scientific and Technical Information of China (English)

    FU Ke-jie; LI Zheng-rong; YANG Li-sheng; MIN Jie; YE Hong-miao

    2006-01-01

    The article evaluated the uncertainty of the content of banned aromatic amines in textile products in terms of GB/T17592. 1 - 1998 Textiles-test Method of Banned Azo Colourants-gas Chromatography/Mass Spectrometric Method, analyzed and quantified the uncertainty components which affected the measurement results.Through calculation, the uncertainty of the sample mainly came from C0 standard uncertainty, weighing, uncertainty of volume, effect on the recovery rate of sample during the course of extraction and purification and ucertainty from the random effect during the course of measurement. It was obtained that the expanded uncertainties of the content of 2 -naphthylamine, benzidine and 2, 4 - diaminotoluene with higher frequency in 24 kinds of forbidden aromatic amines were respectively 2.128, 2.302 and 4.778 mg/kg.

  17. Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines

    Directory of Open Access Journals (Sweden)

    Simona Bettini

    2015-11-01

    Full Text Available Cu,H2-bis-porphyrin (Cu,H2-Por2, in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti conformational switching in the bis-porphyrin derivative. The Langmuir–Schaefer technique has been used to transfer the floating bis-porphyrin film (when using pure water as a subphase to a surface plasmon resonance (SPR substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.

  18. CURING KINETICS AND THERMAL STABILITY OF EPOXY BLENDS CONTAINING PHOSPHOROUS-OXIRANE WITH AROMATIC AMIDE-AMINE AS CURING AGENTS

    Institute of Scientific and Technical Information of China (English)

    Geeta Durga; A.K.Narula

    2012-01-01

    This article describes the synthesis of a series of aromatic amide-amines and their potential use as epoxy hardeners.These amines were synthesized by the reaction of L-phenylalanine (PA) with diamines of different structures i.e.1,4-phenylene diamine (PD),1,5-diamino naphthalene (N),4,4′-(9-fluorenyllidene)-dianiline (F),4,4′-diaminodiphenyl sulphide (DS) and 3,4′-oxydianiline (O) in a stoichiometric ratio (1∶1).Structural characterization of synthesized amide-amines was done with the help of elemental analysis and spectroscopic techniques viz.FT-IR,1H-NMR and 13C-NMR.An epoxy blend was prepared by mixing tris(glycidyloxy) phosphine oxide (TGPO) with conventional epoxy i.e.diglycidyl ether of bisphenol-A (DGEBA) in an equivalent ratio of 2∶3 to incorporate phosphorous into the main chain.The curing kinetics of the epoxy blend with synthesized aromatic amide-amines was investigated by non-isothermal DSC technique using multiple heating rate method (5,10,15 and 20 K/min.).The activation energies were determined by fitting the experimental data into Kissinger and Ozawa kinetic models.The activation energies obtained through Ozawa method were slightly higher than those of Kissinger method but were comparable.However,both the energies were found to be dependent on the structure of amines.The thermal stability and weight loss behavior of isothermally cured thermosets were also investigated using thermogravimetric analysis (TGA) in nitrogen atmosphere.All the samples showed improved thermal stability in terms of char yield than using only amines as hardeners.

  19. Biotransformation of Trichoderma spp. and their tolerance to aromatic amines, a major class of pollutants.

    Science.gov (United States)

    Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Dairou, Julien

    2013-08-01

    Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.

  20. Survey of Primary Aromatic Amines and Colorants in Polyurethane, Nylon and Textile Toys.

    Science.gov (United States)

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Akiyama, Hiroshi; Kawamura, Yoko

    2016-01-01

    The residual and migration levels of 28 primary aromatic amines (PAAs) in polyurethane and nylon toys were determined using LC-MS/MS, and the migration and residual amounts of PAAs and 15 colorants in textile toys were determined using LC-MS/MS and LC-TOF-MS according to the European Standard EN71. Among 34 polyurethane toy samples, 2,6-diaminotoluene and 2,4-diaminotoluene were detected in the same 12 samples at residual levels ranging from 2.1 to 19.7 and from 7.6 to 39.6 μg/g, respectively. Furthermore, 4,4'-diaminodiphenylmethane (4,4'-MDA) and aniline were detected in 9 samples (from 0.2 to 8.7 μg/g), and one sample (0.4 μg/g), respectively. PAAs were not detected in the 8 samples of nylon toys. As for the migration test into water, only 4,4'-MDA migrated from 3 polyurethane toys at levels ranging from 0.4 to 2.5 μg/g. PAAs did not migrate from the 43 textile toys, but colorants such as Solvent Yellow 1 and Basic Red 9 were detected at the residual level of 0.02 μg/g. The residual levels of PAAs and colorants detected in this study were significantly lower than the limit values established by the European Union regulation.

  1. Bladder tumors and aromatic amines - historical milestones from Ludwig Rehn to Wilhelm Hueper.

    Science.gov (United States)

    Dietrich, Holger Georg; Golka, Klaus

    2012-01-01

    We know today that environmental factors must be regarded as a significant cause of the urinary bladder carcinoma. In Germany, the urinary bladder carcinoma is the second most common urological tumor among men and the most common among women and more than 100 occupational bladder cases are recognized and compensated per year. Scientific studies of this problem reach back to the 18th century. However it was only in 1895 that the surgeon Ludwig Rehn firstly described 3 cases of occupational bladder tumors in at most 45 fuchsine workers in Frankfurt / M. This extremely significant discovery was followed by a description of a large number of cases of urinary bladder tumors among workers in the paint industry. Nevertheless, it was impossible to induce bladder cancer in animals by aromatic amines for many years. In the 1930s, the pathologist Wilhelm C. Hueper was the first to induce bladder cancer in animal experiments, applying beta-naphthylamine to dogs. Based on these experiments and corroborated by epidemiologic studies, beta-naphthylamine was banned in Germany and many countries from the 1950s on. This review will highlight work and life of these two pioneering medical researchers.

  2. [Heterocyclic aromatic amines, food-derived mutagens: metabolism and relevance to cancer susceptibility].

    Science.gov (United States)

    Woziwodzka, Anna; Tarasewicz, Marta; Piosik, Jacek

    2010-01-01

    It is estimated that diet contributes to as much as one-third of cancer incidents. Heterocyclic aromatic amines (HCAs) are well-known mutagens/carcinogens found in thermal-processed meat and fish. HCAs require metabolic activation to exert their carcinogenic potential. First step in HCAs activation--the generation of N-hydroxy-HCA derivatives--is catalyzed by cytochrome P450, mainly isoenzyme CYP1A2. Further activation is carried out by N-acetyltransferases and sulfotransferases, which catalyze esterification of N-hydroxy-HCAs. The products of these reactions are highly genotoxic, capable of direct interaction with DNA by adduct formation. HCA-DNA adducts may cause errors in DNA replication and the generation of mutations, which, when not repaired, may contribute to cancer development. On the other hand, among enzymes involved in HCAs detoxication, UDP-glucuronosyltransferases and glutathione S-transferases can be mentioned. Balance between activation and detoxication processes of HCAs, together with genetically determined differences in HCA metabolism are crucial for the assessment of HCA-dependent cancer risk among individuals.

  3. Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane.

    Science.gov (United States)

    Haddenham, Dustin; Pasumansky, Lubov; DeSoto, Jamie; Eagon, Scott; Singaram, Bakthan

    2009-03-06

    Diisopropylaminoborane [BH(2)N(iPr)(2)] in the presence of a catalytic amount of lithium borohydride (LiBH(4)) reduces a large variety of aliphatic and aromatic nitriles in excellent yields. BH(2)N(iPr)(2) can be prepared by two methods: first by reacting diisopropylamineborane [(iPr)(2)N:BH(3)] with 1.1 equiv of n-butyllithium (n-BuLi) followed by methyl iodide (MeI), or reacting iPrN:BH(3) with 1 equiv of n-BuLi followed by trimethylsilyl chloride (TMSCl). BH(2)N(iPr)(2) prepared with MeI was found to reduce benzonitriles to the corresponding benzylamines at ambient temperatures, whereas diisopropylaminoborane prepared with TMSCl does not reduce nitriles unless a catalytic amount of a lithium ion source, such as LiBH(4) or lithium tetraphenylborate (LiBPh(4)), is added to the reaction. The reductions of benzonitriles with one or more electron-withdrawing groups on the aromatic ring generally occur much faster with higher yields. For example, 2,4-dichlorobenzonitrile was successfully reduced to 2,4-dichlorobenzylamine in 99% yield after 5 h at 25 degrees C. On the other hand, benzonitriles containing electron-donating groups on the aromatic ring require refluxing in tetrahydrofuran (THF) for complete reduction. For instance, 4-methoxybenzonitrile was successfully reduced to 4-methoxybenzylamine in 80% yield. Aliphatic nitriles can also be reduced by the BH(2)N(iPr)(2)/cat. LiBH(4) reducing system. Benzyl cyanide was reduced to phenethylamine in 83% yield. BH(2)N(iPr)(2) can also reduce nitriles in the presence of unconjugated alkenes and alkynes such as the reduction of 2-hexynenitrile to hex-5-yn-1-amine in 80% yield. Unfortunately, selective reduction of a nitrile in the presence of an aldehyde is not possible as aldehydes are reduced along with the nitrile. However, selective reduction of the nitrile group at 25 degrees C in the presence of an ester is possible as long as the nitrile group is activated by an electron-withdrawing substituent. It should be

  4. The effect of water resistance in the primary coating by silane coupling agents and amine synergists

    Science.gov (United States)

    Kim, Min-Jeong; Min, Kyoungbeom; Kim, Sanghwan; Yoon, Jung-Woo; Kwak, Seungjo; Lee, Ji-hye; Oh, Sungkoog

    2008-11-01

    In order to clarify the relationship between the water resistance and compositional additives in the primary coating for optical fibers, we prepared various primary coatings that contained silane coupling agents in combination with amine synergists. We observed the appearance of the interface between glass and primary coating after soaking in water at 65° for 30 days. Water resistance was found to be heavily influenced by the content and type of silane coupling agents and amine synergists and their trends are reported.

  5. Indirect methane aromatization via oxidative coupling, products separation and aromatization steps

    Energy Technology Data Exchange (ETDEWEB)

    Skutil, Krzysztof; Taniewski, Marian [Silesian Technical University, Chair of Chemical Organic Technology and Petrochemistry, ul. Krzywoustego 4, 44-101 Gliwice (Poland)

    2007-09-15

    Integrated process of indirect methane aromatization, composed of the methane oxidative coupling (OCM), products separation for elimination of some components and aromatization of the remaining compounds to benzene, toluene and naphthalene, has been studied as an alternative to direct non-oxidative methane aromatization (MDA). Two modes of the integrated process were investigated in the continuous flow laboratory unit: IP 1 - composed of OCM, separation of CO{sub 2} and H{sub 2}O and aromatization and IP 2 - composed of OCM, separation of CO{sub 2}, H{sub 2}O and C{sub 2} hydrocarbons and aromatization. The OCM and aromatization steps were carried out in the presence of 1% Li/MgO at 1023 K and 4.3% Mo/HZSM-5 at 998 K, respectively. The aromatization of individuals - CH{sub 4}, C{sub 2}H{sub 4} and C{sub 2}H{sub 6} was also investigated. Under applied aromatization conditions about a half of ethylene was converted to aromatics whereas the other part to undesirable CH{sub 4} and deposit. It was confirmed that the removal from the OCM products such constituents, which exert detrimental effect on the course of aromatization (CO{sub 2} and H{sub 2}O), led to the marked increase in the aromatics yield in IP 1, as compared with MDA. The approximate additivity of the amounts of benzene formed from methane and from C{sub 2} hydrocarbons contained in the OCM products was observed. Thus, it was confirmed that both C{sub 2} hydrocarbons and CH{sub 4} contained in the OCM effluent gases participated in the formation of aromatics. A full conversion of more reactive C{sub 2} hydrocarbons and a partial conversion of less reactive CH{sub 4} were observed in the aromatization step. Hydrogen and benzene were the main products of the integrated IP 1 process. The hydrogen/benzene ratio was lower than in MDA due to participation of less hydrogen-producing C{sub 2}s in the formation of benzene. The overall CH{sub 4} conversion was, under applied conditions, somewhat higher than in MDA

  6. An acetyltransferase conferring tolerance to toxic aromatic amine chemicals: molecular and functional studies.

    Science.gov (United States)

    Martins, Marta; Rodrigues-Lima, Fernando; Dairou, Julien; Lamouri, Aazdine; Malagnac, Fabienne; Silar, Philippe; Dupret, Jean-Marie

    2009-07-10

    Aromatic amines (AA) are a major class of environmental pollutants that have been shown to have genotoxic and cytotoxic potentials toward most living organisms. Fungi are able to tolerate a diverse range of chemical compounds including certain AA and have long been used as models to understand general biological processes. Deciphering the mechanisms underlying this tolerance may improve our understanding of the adaptation of organisms to stressful environments and pave the way for novel pharmaceutical and/or biotechnological applications. We have identified and characterized two arylamine N-acetyltransferase (NAT) enzymes (PaNAT1 and PaNAT2) from the model fungus Podospora anserina that acetylate a wide range of AA. Targeted gene disruption experiments revealed that PaNAT2 was required for the growth and survival of the fungus in the presence of toxic AA. Functional studies using the knock-out strains and chemically acetylated AA indicated that tolerance of P. anserina to toxic AA was due to the N-acetylation of these chemicals by PaNAT2. Moreover, we provide proof-of-concept remediation experiments where P. anserina, through its PaNAT2 enzyme, is able to detoxify the highly toxic pesticide residue 3,4-dichloroaniline in experimentally contaminated soil samples. Overall, our data show that a single xenobiotic-metabolizing enzyme can mediate tolerance to a major class of pollutants in a eukaryotic species. These findings expand the understanding of the role of xenobiotic-metabolizing enzyme and in particular of NATs in the adaptation of organisms to their chemical environment and provide a basis for new systems for the bioremediation of contaminated soils.

  7. N-acetyltransferase 2, exposure to aromatic and heterocyclic amines, and receptor-defined breast cancer.

    Science.gov (United States)

    Rabstein, Sylvia; Brüning, Thomas; Harth, Volker; Fischer, Hans-Peter; Haas, Susanne; Weiss, Tobias; Spickenheuer, Anne; Pierl, Christiane; Justenhoven, Christina; Illig, Thomas; Vollmert, Caren; Baisch, Christian; Ko, Yon-Dschun; Hamann, Ute; Brauch, Hiltrud; Pesch, Beate

    2010-03-01

    The role of N-acetyltransferase 2 (NAT2) polymorphism in breast cancer is still unclear. We explored the associations between potential sources of exposure to aromatic and heterocyclic amines (AHA), acetylation status and receptor-defined breast cancer in 1020 incident cases and 1047 population controls of the German GENICA study. Acetylation status was assessed as slow or fast. Therefore, NAT2 haplotypes were estimated using genotype information from six NAT2 polymorphisms. Most probable haplotypes served as alleles for the deduction of NAT2 acetylation status. The risks of developing estrogen receptor alpha (ER) and progesterone receptor (PR)-positive or negative tumors were estimated for tobacco smoking, consumption of red meat, grilled food, coffee, and tea, as well as expert-rated occupational exposure to AHA with logistic regression conditional on age and adjusted for potential confounders. Joint effects of these factors and NAT2 acetylation status were investigated. Frequent consumption of grilled food and coffee showed higher risks in slow acetylators for receptor-negative tumors [grilled food: ER-: odds ratio (OR) 2.57, 95% confidence interval (CI) 1.07-6.14 for regular vs. rare; coffee: ER-: OR 2.55, 95% CI 1.22-5.33 for >or=4 vs. 0 cups/day]. We observed slightly higher risks for never smokers that are fast acetylators for receptor-positive tumors compared with slow acetylators (ER-: OR 1.32, 95% CI 1.00-1.73). Our results support differing risk patterns for receptor-defined breast cancer. However, the modifying role of NAT2 for receptor-defined breast cancer is difficult to interpret in the light of complex mixtures of exposure to AHA.

  8. Extraction and Spectrophotometric Determination of Molybdenum with o-Hydroxythiophenols and Aromatic Amines

    Directory of Open Access Journals (Sweden)

    A. Z. Zalov

    2015-06-01

    Full Text Available The interaction of molybdenum (VI with o-hydroxythiophenol derivatives (HTPDs and aromatic amines (AAs was studied. The following three HTPDs, which contain different halogen atoms at position 5, were used: 2-hydroxy-5-chlorothiophenol(HCTP, 2-hydroxy-5-bromothiophenol (HBTP, 2-hydroxy-5-iodothiophenol (HITP]. The examined AAs were aniline (An, N-methylaniline (mAn and N,N-dimethylaniline (dAn. The obtained ternary complexes have a composition of 1:2:2 {Mo(V:HBTP:AA}.Optimal conditions for their liquid-liquid extraction (LLE were found: organic solvent (chloroform, pH (4-6, concentration of the reagents ((1.3-1.510–3moldm–3 (HTPD and (1.2-1.510–3moldm–3 (AA and extraction time(colour develops almost immediately after the reagents addition. The absorbance of the extracts is stable for at least 48 hours. The optimum shaking time is 10 min.. Under the optimal conditions, the complexes have absorption maxima (max at 515-538 nm and molar absorptivities (max between 3.1104dm3mol–1 cm–1. The degrees of extraction were 98.4%. The results suggested that linear relationships exist between the spectral characteristics (max or max and some fundamental properties of the halogen substituent in the HTPD (atomic mass and electronegativity. The effect of foreign ions on the LLE-spectrophotometric determination of molybdenum was examined and two sensitive, selective and precise procedures for molybdenum determination were proposed. The relative standard deviations for Mo content of (3-510–4 % were 4% (HCTP-An procedure and 3% (HBTP-An procedure.

  9. Determination of aromatic amines in aqueous extracts of polyurethane foam using hydrophilic interaction liquid chromatography and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Riddar Johnson, Jakob, E-mail: jakob.riddarjohnson@anchem.su.se [Work Environment Chemistry, Stockholm University, P.O. Box 460, 281 24 Haessleholm (Sweden); Karlsson, Daniel; Dalene, Marianne; Skarping, Gunnar [Work Environment Chemistry, Stockholm University, P.O. Box 460, 281 24 Haessleholm (Sweden)

    2010-09-23

    A method is presented for the determination of aromatic amines in aqueous extracts of polyurethane (PUR) foam. The method is based on the extraction of PUR foam using aqueous acetic acid (0.1%, w/v) followed by determination of extracted aromatic amines using hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry (MS/MS) with positive electrospray ionisation. The injections of volumes up to 5 {mu}L of aqueous solutions were made possible by on-column focusing with partially filled loop injections. The fragmentation patterns for 2,4- and 2,6-toluene diamine (TDA) and 4,4'-methylene dianiline (MDA) were clarified by performing a hydrogen-deuterium exchange study. TDA and MDA were determined using trideuterated 2,4- and 2,6-TDA and dideuterated 4,4'-MDA as internal standards. Linear calibration graphs were obtained over the range 0.025-0.5 {mu}g mL{sup -1} with correlation coefficients >0.996 and the instrumental detection limit for each compound was <50 fmol. The stability of the amines was influenced by the matrix, so their concentrations decreased over time. Agreement was observed between the results of analyses of PUR foam extracts by HILIC-MS/MS and results obtained by ethyl chloroformate derivatisation and reversed phase (RP) liquid chromatography-mass spectrometry (LC-MS/MS). TDA was observed to be unstable in extracts of foam but not in pure solutions.

  10. An in silico method for predicting Ames activities of primary aromatic amines by calculating the stabilities of nitrenium ions.

    Science.gov (United States)

    Bentzien, Jörg; Hickey, Eugene R; Kemper, Raymond A; Brewer, Mark L; Dyekjaer, Jane D; East, Stephen P; Whittaker, Mark

    2010-02-22

    In this paper, we describe an in silico first principal approach to predict the mutagenic potential of primary aromatic amines. This approach is based on the so-called "nitrenium hypothesis", which was developed by Ford et al. in the early 1990s. This hypothesis asserts that the mutagenic effect for this class of molecules is mediated through the transient formation of a nitrenium ion and that the stability of this cation is correlated with the mutagenic potential. Here we use quantum mechanical calculations at different levels of theory (semiempirical AM1, ab initio HF/3-21G, HF/6-311G(d,p), and DFT/B3LYP/6-311G(d,p)) to compute the stability of nitrenium ions. When applied to a test set of 257 primary aromatic amines, we show that this method can correctly differentiate between Ames active and inactive compounds, and furthermore that it is able to rationalize and predict SAR trends within structurally related chemical series. For this test set, the AM1 nitrenium stability calculations are found to provide a good balance between speed and accuracy, resulting in an overall accuracy of 85%, and sensitivity and specificity of 91% and 72%, respectively. The nitrenium-based predictions are also compared to the commercial software packages DEREK, MULTICASE, and the MOE-Toxicophore descriptor. One advantage of the approach presented here is that the calculation of relative stabilities results in a continuous spectrum of activities and not a simple yes/no answer. This allows us to observe and rationalize subtle trends due to the different electrostatic properties of the organic molecules. Our results strongly indicate that nitrenium ion stability calculations should be used as a complementary approach to assist the medicinal chemist in prioritizing and selecting nonmutagenic primary aromatic amines during preclinical drug discovery programs.

  11. Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

    Science.gov (United States)

    Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

    2013-04-12

    Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples.

  12. 23种致癌芳香胺的显色法测定%Chromogenic method determination of 23 kinds of carcinogenic aromatic amines

    Institute of Scientific and Technical Information of China (English)

    叶曦雯; 李引; 牛增元; 张清智; 高永刚

    2012-01-01

    In order to reduce the dependence on large-scale chromatographs, improve the detection speed and cut the cost of testing, a chromogenic determination method for 23 kinds of carcinogenic aromatic amines through reacting with guaiacol was developed. According to the structural features of aromatic amines and mechanism of diazo-coupling reaction, all terms of diazo-coupling reaction process were studied and optimized effectively. The optimal conditions were obtained as follows; at room temperature, 23 kinds of carcinogenic aromatic amines reacted with sodium nitrite and diazo salt was formed at a pH value of 2.56, and then added ammonium sulfamate, removing the excessive sodium nitrite, guaiacol was added to produce coupling /developing reaction with the diazo salt; the best developing pH ranged from 10 to 11, and developing reaction could be completed quickly, and the resulting azo compound remained stable within 180 min. Linearity was excellent in the concentration range of 1 - 50 mg/L. This method could be effectively applied to textiles in qualitative screening test of 23 kinds of carcinogenic aromatic amines.%为了减少禁用芳香胺检测过程对大型色谱仪的依赖,提高检测速度,降低检测成本,建立了23种致癌芳香胺的邻甲氧基苯酚显色测定方法.根据芳香胺的结构特征,引入重氮化-偶合反应机制,有效考察优化了23种芳香胺重氮化反应和偶合反应过程中的各项条件,得到最佳的反应条件:在室温下,23种芳香胺和亚硝酸钠在pH值为2.56时反应生成重氮盐,加入氨基磺酸铵除去多余的亚硝酸钠后,加入邻甲氧基苯酚与重氮盐偶联显色,显色的最佳pH值范围为10~11,显色反应可以迅速完成,生成的偶氮化合物可稳定180 min以上.方法的线性范围为1~ 50 mg/L.该方法操作简单易行,可有效地应用于纺织品中23种致癌芳香胺的同时定性筛选检测.

  13. CYP-450 isoenzymes catalyze the generation of hazardous aromatic amines after reaction with the azo dye Sudan III

    OpenAIRE

    Zanoni, Thalita Boldrin; Lizier, Thiago M. [UNESP; Assis,Marilda das Dores; Zanoni, Maria Valnice Boldrin; de Oliveira, Danielle Palma

    2013-01-01

    This work describes the mutagenic response of Sudan III, an adulterant food dye, using Salmonella typhimurium assay and the generation of hazardous aromatic amines after different oxidation methods of this azo dye. For that, we used metabolic activation by S9, catalytic oxidation by ironporphyrin and electrochemistry oxidation in order to simulate endogenous oxidation conditions. The oxidation reactions promoted discoloration from 65% to 95% of Sudan III at 1×10-4molL-1 and generation of 7.6×...

  14. Microwave-Accelerated Iodination of Some Aromatic Amines, Using Urea-Hydrogen Peroxide Addition Compound (UHP as the Oxidant

    Directory of Open Access Journals (Sweden)

    Lech Skulski

    2002-12-01

    Full Text Available A fast and simple method for the oxidative iodination of some aromatic amines, under microwave irradiation, is reported, using diiodine and the the strongly Hbonded urea-hydrogen peroxide addition compound (H2NCONH2···H2O2, UHP as the oxidant. The reactions were carried out in boiling CHCl3 under a reflux condenser to afford, within 10 minutes, the purified monoiodinated products in 40-80% yields.

  15. Influence of aromatic amine hardeners in the cure kinetics of an epoxy resin used in advanced composites

    Directory of Open Access Journals (Sweden)

    Michelle Leali Costa

    2005-03-01

    Full Text Available Composite structures for aerospace applications are mainly made by the well-known prepreg technology. In order to achieve adequate prepreg processing schedules, and consequently maximum fiber strength utilization, one has to know in deep the cure kinetics of matrix, which held the fibers together. This work describes a procedure to study the cure kinetic and has as example how aromatic amine hardeners influence the cure kinetics of an epoxy resin used in advanced composites. The investigation was carried out by using the DSC technique and it was found that depending on the system used the cure kinetics of the formulation obeys order n or autocatalytic order.

  16. Technical guidelines on testing the migration of primary aromatic amines from polyamide kitchenware and of formaldehyde from melamine kitchenware

    DEFF Research Database (Denmark)

    Simoneau, C.; Hoekstra, E.; Bradley, E.

    conditions used as well as on the performance of the method of analysis. These guidelines contain practical information on sampling, migration testing and methodologies for the analytical determination of primary aromatic amines and of formaldehyde. These guidelines were developed specifically in the context......Comparability of results is an important feature of the measurements carried out for official controls purposes. In the area of food contact materials and articles comparability of results is dependent on the availability of samples representative of a consignment, the type of exposure and the test...

  17. Heterocyclic Aromatic Amines in Domestically Prepared Chicken and Fish from Singapore Chinese Households

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, C P; Knize, M G; Felton, J S; Zhao, B; Seow, A

    2005-05-16

    Chicken and fish samples prepared by 42 Singapore Chinese in their homes were obtained. Researchers were present to collect data on raw meat weight, cooking time, maximum cooking surface temperature, and cooked meat weight. Each participant prepared one pan-fried fish sample and two pan-fried chicken samples, one marinated, one not marinated. The cooked samples were analyzed for five heterocyclic aromatic amine (HAA) mutagens, including MeIQx (2-amino 3,8-dimethylimidazo[4,5-f]quinoxaline); 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline); 7,8-DiMeIQx (2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline); PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), and IFP (2-amino-(1,6-dimethylfuro[3,2-e]imidazo [4,5-b])pyridine). A paired Student's t-test showed that marinated chicken had lower concentrations of PhIP (p<0.05), but higher concentrations of MeIQx (p<0.05) and 4,8-DiMeIQx (p<0.001) than non-marinated chicken, and also that weight loss due to cooking was less in marinated chicken than in non-marinated chicken (p<0.001). Interestingly, the maximum cooking surface temperature was higher for fish than for either marinated or non-marinated chicken (P<0.001), yet fish was lower in 4,8-DiMeIQx per gram than marinated or non-marinated chicken (p<0.001), lower in PhIP than non-marinated chicken (P<0.05), and lost less weight due to cooking than either marinated or non-marinated chicken (P<0.001). Fish was also lower in MeIQx and 7,8-DiMeIQx than marinated chicken (P<0.05). This study provides new information on HAA content in the Singapore Chinese diet.

  18. Acrolein, an α,β-unsaturated aldehyde, irreversibly inhibits the acetylation of aromatic amine xenobiotics by human arylamine N-acetyltransferase 1.

    Science.gov (United States)

    Bui, Linh C; Manaa, Amine; Xu, Ximing; Duval, Romain; Busi, Florent; Dupret, Jean-Marie; Rodrigues-Lima, Fernando; Dairou, Julien

    2013-07-01

    Acrolein is an electrophilic α,β-unsaturated aldehyde of industrial, pharmaceutic, and toxicologic importance to which we are exposed in environmental, occupational, and therapeutic situations. Acrolein is known to exert different biologic effects through reactions with cellular macromolecules such as DNA, certain proteins, or glutathione. In many situations (such as in tobacco smoke or other fumes), exposure to acrolein occurs concomitantly with other compounds such as aromatic amine chemicals. Interestingly, it has been shown that acrolein could impact the cellular metabolism of aromatic xenobiotics through an indirect mechanism based on the transcriptional induction of phase II xenobiotic-metabolizing enzymes. Here we report a novel mechanism by which acrolein acts on the metabolism of aromatic foreign chemicals. We provide molecular, kinetic, and cellular evidence that acrolein can react directly and irreversibly with arylamine N-acetyltransferases, a major family of xenobiotic-metabolizing enzymes involved in the metabolization of aromatic amine chemicals. Formation of an acrolein adduct with a catalytic cysteine residue in the active site is responsible for the impairment of aromatic amine acetylation by the enzyme. This biochemical process may represent an additional mechanism by which acrolein impacts the metabolism and fate of aromatic amine drugs and pollutants.

  19. Reaction of 2,4-Dinitrochlorobenzene with Aromatic Amines in Toluene: Effect of Nucleophile Structure

    Directory of Open Access Journals (Sweden)

    C. E.S. Alvaro

    2000-03-01

    Full Text Available The kinetics of the reaction of 2,4-dinitrochlorobenzene (DNClB with aniline and substituted anilines such as p-anisidine, p-toluidine and N-methylaniline have been studied in toluene. Except for N-methylaniline the reactions have shown a third order in amine rate dependence which is consistent with aggregates of the amine acting as the nucleophile. On the other hand, the reaction of DNClB with N-methylaniline under the same conditions shows a linear dependence of the second order rate coefficient, kA, vs [amine], which is consistent with the previous mechanism.

  20. Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

    KAUST Repository

    He, Lipeng

    2012-07-23

    Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

  1. Suitability of the in vitro Caco-2 assay to predict the oral absorption of aromatic amine hair dyes.

    Science.gov (United States)

    Obringer, Cindy; Manwaring, John; Goebel, Carsten; Hewitt, Nicola J; Rothe, Helga

    2016-04-01

    Oral absorption is a key element for safety assessments of cosmetic ingredients, including hair dye molecules. Reliable in vitro methods are needed since the European Union has banned the use of animals for the testing of cosmetic ingredients. Caco-2 cells were used to measure the intestinal permeability characteristics (Papp) of 14 aromatic amine hair dye molecules with varying chemical structures, and the data were compared with historical in vivo oral absorption rat data. The majority of the hair dyes exhibited Papp values that indicated good in vivo absorption. The moderate to high oral absorption findings, i.e. ≥60%, were confirmed in in vivo rat studies. Moreover, the compound with a very low Papp value (APB: 3-((9,10-dihydro-9,10-dioxo-4-(methylamino)-1-anthracenyl)amino)-N,N-dimethyl-N-propyl-1-propanaminium) was poorly absorbed in vivo as well (5% of the dose). This data set suggests that the Caco-2 cell model is a reliable in vitro tool for the determination of the intestinal absorption of aromatic amines with diverse chemical structures. When used in combination with other in vitro assays for metabolism and skin penetration, the Caco-2 model can contribute to the prediction and mechanistic interpretation of the absorption, metabolism and elimination properties of cosmetic ingredients without the use of animals.

  2. Determination of Aromatic Amines Released from Azo Dyes in Paper Packaging by Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Yang, Fei; Bian, Zhaoyang; Li, Zhonghao; Fan, Ziyan; Wang, Ying; Liu, ShanShan; Deng, Huimin; Tang, Gangling

    2016-09-01

    An LC-tandem MS (LC-MS/MS) method for the determination of 21 kinds of carcinogenic aromatic amines released from azo dyes in food wrappers was used in this research. Sodium dithionite was added to a citric acid buffer medium to reduce and decompose possible azo dyes. The extract was analyzed after liquid-liquid extraction (LLE) and dispersive SPE (d-SPE). The conditions for chromatographic separation, mass spectrum, LLE, and d-SPE were optimized. Under optimal conditions, the LOD was in the range of 0.13-0.35 mg/kg and LOQ in the range of 0.38-1.05 mg/kg, with the addition of standard recoveries of most aromatic amines being ≥80% and RSDs ≤10%. The recoveries for 2,4-diaminotoluene and 2,4-diaminoanisole were significantly lower, being ≤40%. The method was successfully used to analyze 30 practical samples, and the results showed that it is user-friendly, with high sensitivity, rapid control, and low matrix interference.

  3. Formation of mutagenic heterocyclic aromatic amines in fried pork from Duroc and Landrace pigs upon feed supplementation with creatine monohydrate.

    Science.gov (United States)

    Pfau, Wolfgang; Rosenvold, Katja; Young, Jette F

    2006-12-01

    Heterocyclic aromatic amines (HAA) have been shown to induce tumours at various organ sites in experimental animal studies and high levels of dietary intake of HAA have been associated with increased cancer risk in humans. These HAA are formed in meat upon heating from precursors such as amino acids, reducing sugars and creatine or creatinine. Groups of ten Duroc and ten Landrace pigs received feed supplemented with creatine monohydrate (CMH) for five days prior to slaughter at dose levels of 12.5, 25 and 50 g per animal per day. Ten control animals of each breed received the non-supplemented feed. Meat from Duroc pigs had been shown to respond to CMH supplementation with regard to waterholding capacity, juiciness, post slaughter pH and colour parameters, meat from Landrace pigs was unaffected. Indeed, while creatine phosphate levels in meat from Duroc pigs increased in a dose-dependent manner with CMH supplementation, no effect was observed in meat from Landrace pigs. Meat slices from longissimus dorsi were fried and considerable mutagenic activity was detected in meat extracts in Salmonella typhimurium YG1019 in the presence of rat-liver homogenate. However, no effect of breed or CMH supplementation was observed in fried pork on the formation of HAA determined as mutagenic activity. It may be concluded that feed supplementation with CMH at levels up to 50 g per day for five days prior to slaughter does not increase the level of heterocyclic aromatic amines detected as mutagenic activity formed upon frying of pork.

  4. Preparation of symmetric and asymmetric aromatic azo compounds from aromatic amines or nitro compounds using supported gold catalysts.

    Science.gov (United States)

    Grirrane, Abdessamad; Corma, Avelino; Garcia, Hermenegildo

    2010-03-01

    This protocol describes the aerobic oxidation of aromatic anilines to aromatic azo compounds using gold (Au) nanoparticles supported on TiO(2) as a catalyst. Yields above 98% are achieved under a few bars of oxygen pressure. It should be noted that the use of stoichiometric amounts of environmentally unfriendly reagents, e.g., transition metals and nitrites, commonly used in current syntheses of azo compounds, is avoided using this approach. The protocol is illustrated with the synthesis of parent azobenzene from aniline, and this reaction takes 22 h. Au on TiO(2) can also be used as a hydrogenation catalyst, making it possible to prepare azo compounds directly from nitroaromatics through a two-step (hydrogenation followed by aerobic oxidation), one-pot, one-catalyst reaction. In addition, the catalytic process is efficient for the synthesis of symmetric and a range of asymmetric aromatic azo compounds from the mixtures of two anilines substituted with electron-donor and electron-acceptor substituents.

  5. Visual Recognition of Aliphatic and Aromatic Amines Using a Fluorescent Gel: Application of a Sonication-Triggered Organogel.

    Science.gov (United States)

    Pang, Xuelei; Yu, Xudong; Lan, Haichuang; Ge, Xiaoting; Li, Yajuan; Zhen, Xiaoli; Yi, Tao

    2015-06-24

    A naphthalimide-based fluorescent gelator (N1) containing an alkenyl group has been designed and characterized. This material is able to gelate alcohols via a precipitate-to-gel transformation when triggered with ultrasound for less than 2 min (S-gel). The gelation process in n-propanol was studied by means of absorption, fluorescence, and IR spectra, scanning electron microscopy (SEM) images, and X-ray diffraction patterns. The fluorescence intensity of N1 decreased during the gelation process in a linear relationship with the sonication time. The S-gel of N1 could be used to sense aliphatic and aromatic amines by measuring the change in the signal output. For example, the addition of propylamine to the S-gel of N1 resulted in a dramatic enhancement of the fluorescence intensity, accompanied by a gel-to-sol transition. On the contrary, when the S-gel of N1 was treated with aromatic amines such as aniline, fluorescence was quenched and there was no gel collapse. The sensing mechanisms were studied by (1)H NMR, small-angle X-ray scattering, SEM and spectroscopic experiments. It is proposed that isomerization of the alkenyl group of N1 from the trans to cis form occurs when the S-gel is treated with propylamine, resulting in a gel-sol transition. However, the aromatic aniline molecules prefer to insert into the gel networks of N1 via hydrogen-bonding and charge-transfer interactions, maintaining the gel state. As potential applications, testing strips of N1 were prepared to detect aniline.

  6. Copper and amine free Sonogashira cross-coupling reaction catalyzed by efficient diphosphane-palladium catalyst

    Institute of Scientific and Technical Information of China (English)

    Ting He; Lei Lei Wu; Xing Li Fu; Hai Yan Fu; Hua Chen; Rui Xiang Li

    2011-01-01

    The commercially available diphosphane ligand MeO-BIPHEP was first investigated in the palladium-catalyzed Sonogashira reaction in the absence of copper and amine. The coupling of various aryl bromides and aryl chlorides with phenylacetylene gave moderate to excellent yields.

  7. Dimethylzinc-Initiated Radical Coupling of β-Bromostyrenes with Ethers and Amines

    DEFF Research Database (Denmark)

    Sølvhøj, Amanda Birgitte; Ahlburg, Andreas; Madsen, Robert

    2015-01-01

    A new coupling reaction has been developed in which β-bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α-position. The transformation is mediated by Me2Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition-elimination mechanism. The ether...

  8. Specific determination of 20 primary aromatic amines in aqueous food simulants by liquid chromatography-electrospray ionization-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Mortensen, Sarah Kelly; Trier, Xenia Thorsager; Foverskov, Annie

    2005-01-01

    A multi-analyte method without any pre-treatment steps using reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was developed and applied for the determination of 20 primary aromatic amines (PAA) associated with polyurethane (PUR) products or azo...

  9. Photocatalytic organic transformation by layered double hydroxides: highly efficient and selective oxidation of primary aromatic amines to their imines under ambient aerobic conditions.

    Science.gov (United States)

    Yang, Xiu-Jie; Chen, Bin; Li, Xu-Bing; Zheng, Li-Qiang; Wu, Li-Zhu; Tung, Chen-Ho

    2014-06-25

    We report the first application of layered double hydroxide as a photocatalyst in the transformation of primary aromatic amines to their corresponding imines with high efficiency and selectivity by using oxygen in an air atmosphere as a terminal oxidant under light irradiation.

  10. Heterocyclic aromatic amine content in chicken burgers and chicken nuggets sold in fast food restaurants and effects of green tea extract and microwave thawing on their formation

    Science.gov (United States)

    The aims of the current study were to investigate the presence of carcinogenic and mutagenic heterocyclic aromatic amines (HAAs) in chicken burgers (CBs) and chicken nuggets (CNs) purchased from fast food restaurants and the effects of green tea extract addition (GTE) to the covering material as wel...

  11. Effects of polyunsaturated fatty acids on prostaglandin synthesis and cyclooxygenase-mediated DNA adduct formation by heterocyclic aromatic amines in human adenocarcinoma colon cells

    NARCIS (Netherlands)

    Moonen, H.J.J.; Dommels, Y.E.M.; Zwam, M.; Herwijnen, van M.H.M.; Kleinjans, J.C.S.; Alink, G.M.; Kok, de T.M.C.M.

    2004-01-01

    Dietary heterocyclic aromatic amines (HCA) and polyunsaturated fatty acids (PUFA) are both believed to play a role in colon carcinogenesis, and are both substrate for the enzyme cyclooxygenase (COX). In HCA-7 cells, highly expressing isoform COX-2, we investigated the effects of PUFA on prostaglandi

  12. 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.

  13. The effects of cooking on wire and stone barbecue at different cooking levels on the formation of heterocyclic aromatic amines and polycyclic aromatic hydrocarbons in beef steak.

    Science.gov (United States)

    Oz, Fatih; Yuzer, M Onur

    2016-07-15

    The effects of type of barbecue (wire and stone) and cooking levels (rare, medium, well-done and very well-done) on the formation of heterocyclic aromatic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) in beef steak were investigated. Varying levels of IQx (up to 0.29 ng/g), IQ (up to 0.93 ng/g), MeIQx (up to 0.08 ng/g), MeIQ (up to 0.75 ng/g), 7,8-DiMeIQx (up to 0.08 ng/g), 4,8-DiMeIQx (up to 4.95 ng/g), PhIP (up to 6.24 ng/g) and AαC (up to 0.20 ng/g) were determined, while MeAαC was not detected. The total HCA amounts in wire barbecued samples were higher than stone barbecued samples. Total HCA contents of the samples ranged between nd and 13.52 ng/g. In terms of PAHs, varying levels of BaA (up to 0.34 ng/g), Chry (up to 0.28 ng/g), BbF (up to 0.39 ng/g), BkF (up to 0.90 ng/g), BaP (up to 0.29 ng/g) and Bghip (up to 0.43 ng/g) were determined, while DahA and IncdP were not detected. The total PAH amounts in stone barbecued samples were higher than those of wire barbecued samples. Total PAH amounts of the samples ranged between nd and 2.63 ng/g.

  14. Copper-Catalyzed Three- Five- or Seven-Component Coupling Reactions: The Selective Synthesis of Cyanomethylamines, N,N-Bis(CyanomethylAmines and N,N'-Bis(CyanomethylMethylenediamines Based on a Strecker-Type Synthesis

    Directory of Open Access Journals (Sweden)

    Takeo Konakahara

    2013-10-01

    Full Text Available We have demonstrated that a cooperative catalytic system comprised of CuCl and Cu(OTf2 could be used to effectively catalyse the three-, five- and seven-component coupling reactions of aliphatic or aromatic amines, formaldehyde, and trimethylsilyl cyanide (TMSCN, and selectively produce in good yields the corresponding cyanomethylamines, N,N-bis(cyanomethylamines and N,N'-bis(cyanomethylmethylenediamines.

  15. A highly versatile catalyst system for the cross-coupling of aryl chlorides and amines.

    Science.gov (United States)

    Lundgren, Rylan J; Sappong-Kumankumah, Antonia; Stradiotto, Mark

    2010-02-08

    The syntheses of 2-(di-tert-butylphosphino)-N,N-dimethylaniline (L1, 71%) and 2-(di-1-adamantylphosphino)-N,N-dimethylaniline (L2, 74 %), and their application in Buchwald-Hartwig amination, are reported. In combination with [Pd(allyl)Cl](2) or [Pd(cinnamyl)Cl](2), these structurally simple and air-stable P,N ligands enable the cross-coupling of aryl and heteroaryl chlorides, including those bearing as substituents enolizable ketones, ethers, esters, carboxylic acids, phenols, alcohols, olefins, amides, and halogens, to a diverse range of amine and related substrates that includes primary alkyl- and arylamines, cyclic and acyclic secondary amines, N-H imines, hydrazones, lithium amide, and ammonia. In many cases, the reactions can be performed at low catalyst loadings (0.5-0.02 mol % Pd) with excellent functional group tolerance and chemoselectivity. Examples of cross-coupling reactions involving 1,4-bromochlorobenzene and iodobenzene are also reported. Under similar conditions, inferior catalytic performance was achieved when using Pd(OAc)(2), PdCl(2), [PdCl(2)(cod)] (cod = 1,5-cyclooctadiene), [PdCl(2)(MeCN)(2)], or [Pd(2)(dba)(3)] (dba = dibenzylideneacetone) in combination with L1 or L2, or by use of [Pd(allyl)Cl](2) or [Pd(cinnamyl)Cl](2) with variants of L1 and L2 bearing less basic or less sterically demanding substituents on phosphorus or lacking an ortho-dimethylamino fragment. Given current limitations associated with established ligand classes with regard to maintaining high activity across the diverse possible range of C-N coupling applications, L1 and L2 represent unusually versatile ligand systems for the cross-coupling of aryl chlorides and amines.

  16. Ultrasonic and spectral studies on charge transfer complexes of anisole and certain aromatic amines

    Science.gov (United States)

    Rajesh, R.; Raj Muhamed, R.; Justin Adaikala Baskar, A.; Kannappan, V.

    2016-10-01

    Stability constants of two complexes of anisole with aniline and N-methylaniline (NMA) are determined from the measured ultrasonic velocity in n-hexane medium at four different temperatures. Acoustic and excess thermo acoustic parameters [excess ultrasonic velocity (uE), excess molar volume (VE), excess internal pressure (πiE)] are reported for these systems at four different temperatures. The trend in acoustic and excess parameters with concentration in the two systems establishes the formation of hydrogen bonded complexes between anisole and the two amines. Thermodynamic properties are computed for the two complexes from the variation in K with temperature. The formation of these complexes is also established by UV spectral method and their spectral characteristics and stability constants are determined. K values of these complexes obtained by ultrasonic and UV spectroscopic techniques agree well. Aniline forms more stable complex than N-methylaniline with anisole in n-hexane medium.

  17. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Manwaring, John, E-mail: manwaring.jd@pg.com [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Rothe, Helga [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany); Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A. [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Hewitt, Nicola J. [SWS, Erzhausen (Germany); Goebel, Carsten [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany)

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

  18. Pioneering Metal-Free Oxidative Coupling Strategy of Aromatic Compounds Using Hypervalent Iodine Reagents.

    Science.gov (United States)

    Kita, Yasuyuki; Dohi, Toshifumi

    2015-10-01

    We started our hypervalent iodine research about 30 years ago in the mid-1980s. We soon successfully developed the single-electron-transfer oxidation ability of a hypervalent iodine reagent, specifically, phenyliodine(III) bis(trifluoroacetate) (PIFA), toward aromatic rings of phenyl ethers for forming aromatic cation radicals. This was one of the exciting and unexpected events in our research studies so far, and the discovery was reported in 1991. It also led to the next challenge, developing the metal-free oxidative couplings for C-H functionalizations and direct couplings between the C-H bonds of valuable aromatic compounds in organic synthesis. In order to realize the effective oxidative coupling, pioneering new aromatic ring activations was essential and several useful methodologies have been found for oxidizable arenes. The achievements regarding this objective obtained in our continuous research are herein summarized with classification of the aromatic ring activation strategies.

  19. Microextraction by packed sorbent and salting-out-assisted liquid-liquid extraction for the determination of aromatic amines formed from azo dyes in textiles.

    Science.gov (United States)

    Sánchez, Miguel del Nogal; Santos, Patricia Martín; Sappó, Cristina Pérez; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

    2014-02-01

    EU legislation prohibits the use of certain azo dyes which, on reduction, form any of 22 aromatic amines listed in Regulation (EC) 1907/2006 at concentrations above the threshold limit of 30 mg Kg(-1). Two different extraction techniques for the determination of aromatic amines formed from azo dyes in textiles in combination with gas chromatography-mass spectrometry (GC-MS) are described. The first one is based on microextraction by packed sorbent (MEPS) and the other approach involves salting-out-assisted liquid-liquid extraction (SALLE). The influence of several parameters on the efficiency of the extraction using MEPS (sorbent material, sample volume, elution solvent, elution volume and washing steps, among others) and SALLE (extraction volume and amount of salt) were investigated. In addition, chromatographic separation was optimized and quadrupole mass spectrometry was evaluated using the synchronous SIM/scan data acquisition mode. The repeatability (n=8, S/N=3) of the methods, calculated as the relative standard deviation (RSD) was below 15 and 11% for all compounds when MEPS and SALLE were used, respectively. Standard additions procedure was used to quantify the aromatic amines in the textil samples. The detection limits in the samples for both methods were lower than the maximum value allowed by legislation. The results obtained in the analysis of textiles revealed the presence of o-anisidine, p-chloroaniline, 4-chloro-o-toluidine, 2-naphthylamine and 3,3'-dimethoxybenzidine in some of them. © 2013 Elsevier B.V. All rights reserved.

  20. The formation and control of heterocyclic aromatic amines in processed meat products%加工肉制品中杂环胺的形成与控制

    Institute of Scientific and Technical Information of China (English)

    万可慧; 邵斌; 姚瑶; 石金明

    2012-01-01

    Heterocyclic aromatic amines are formed easily in fried, smoked and roasted meat products. Most of heterocyclic aromatic amines are mutagenic and carcinogenic, especially for IQ (2-amino-3- methyl-imidazo[4,5-f]quinoline), which is commonly recognized as highly carcinogenic agent to humans by International Agency for the Research of Cancer(IARC). This paper reviewed the current knowledge on the formation of heterocyclic aromatic amines in processed meat products and put forward the specific control measures, which could enhance the public attention and provide scientific basis of a healthy diet.%煎炸熏烤肉制品容易导致杂环胺的产生。杂环胺大多具有致癌致突变性,特别是2-氨基-3-甲基咪唑并[4,5-f]喹啉(IQ),已被国际癌症研究中心列为"对人类高可疑致癌物(2A级)",对人体的健康存在极大的危害。主要对杂环胺形成的影响因素进行了分析,并提出了具体的抑制措施,以增加公众对杂环胺的认识,为健康饮食提供科学依据。

  1. The thermochromic behavior of aromatic amine-SO2 charge transfer complexes

    Science.gov (United States)

    Monezi, Natália M.; Borin, Antonio C.; Santos, Paulo S.; Ando, Rômulo A.

    2017-02-01

    The distinct thermochromism observed in solutions containing N,N-dimethylaniline (DMA) and N,N-diethylaniline (DEA) and SO2 was investigated by resonance Raman spectroscopy in a wide range of temperatures. The results indicate in addition to the charge transfer (CT) complexes DMA-SO2 and DEA-SO2, the presence of collision complexes involving the CT complexes and excess DMA and DEA molecules. The latter in fact is the chromophore responsible for the long wavelength absorption originating the color. The Raman signature of the collision complex was attributed to the distinct enhancement of a band at 1140 cm- 1 assigned to νs(SO2), in contrast to the same mode in the 1:1 complex at 1115 cm- 1. The intensity of such band, assigned to the collision complex is favored at high temperatures and depends on the steric hindrance associated to amines, as well as the SO2 molar fraction. Quantum chemical calculations based on time-dependent density functional theory (TDDFT) support the proposed interpretation.

  2. Impact of different pan-frying conditions on the formation of heterocyclic aromatic amines and sensory quality in fried bacon.

    Science.gov (United States)

    Gibis, Monika; Kruwinnus, Miriam; Weiss, Jochen

    2015-02-01

    Heterocyclic aromatic amines (HAAs) are formed in the crust of cooked meat products. Most HAAs are carcinogenic in long-term animal studies. Besides precursors in raw materials, important factors are temperature and heating time. Bacon slices were investigated for concentrations of HAAs after pan-frying under different monitored heating conditions. Two HAAs, MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (1.5-5.6ng/g) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) (0.1-2.6ng/g), were found in pan-fried bacon slices. The bacon clearly contained higher concentrations of HAAs both with longer frying times and at temperatures of 200-220°C rather than 150-170°C, respectively. A similar continuous increase of the concentrations was observed for norharman (5.0-19.9ng/g) and harman (0.3-1.7ng/g). The sensory evaluation, using a hedonic test design for colour and flavour, of the pan-fried bacon slices resulted in a preferred frying time of 5min at 150-170°C. However, some testers clearly preferred crispy and darker bacon slices containing higher HAA concentrations.

  3. Photodegradation of Polyphenols and Aromatic Amines in Olive Mill Effluents with Ni Doped C/TiO2

    Directory of Open Access Journals (Sweden)

    Delia Teresa Sponza

    2015-01-01

    Full Text Available Magnetic nickel coated carbon based titanium dioxide [C/TiO2/Ni] nanocomposites were used for photodegradation of polyphenols and total aromatic amines (TAAs metabolites from olive mill wastewaters (OMW at different operational conditions such as different mass ratios of C, TiO2, and Ni (1%/2%/5%; 5%/1%/2%; and 2%/5%/1%, being at increasing photodegradation times (15, 30, 45, 60, 75, 120, and 180 min, photocatalyst concentrations (100, 250, 500, and 1000 mg L−1, pH values (3.5, 4.0, 7.0, and 10.0 and temperatures (15°C, 25°C, 50°C, and 80°C, and being under 300 W ultraviolet (UV and 30 W sunlight irradiation. Under the optimized conditions, at pH=7.0, at 500 mg L−1 C/TiO2/Ni nanocomposite, under 300 W UV light, after 60 min, at 25°C, the maximum CODdissolved, total phenol, and TAAs removals were 99%, 90%, and 96%, respectively. Photodegradation removals in the OMW under sunlight and being lower than those under UV light.

  4. Analysis of Primary Aromatic Amines Derived from Azo Colorants in Textile Products and Determination of Their Source Colorant.

    Science.gov (United States)

    Sugaya, Naeko; Sato, Yoshiki; Takahashi, Mitsuko; Sakurai, Katsumi; Kawakami, Tsuyoshi

    2017-01-01

     Twenty-four primary aromatic amines (PAAs) derived from azo colorants, which are controlled by the Act on Control of Household Products Containing Harmful Substances by the Japan Ministry of Health, Labour and Welfare, aniline and 1,4-phenylendiamine were analyzed in 86 samples of 40 textile products by GC-MS. Even though these PAAs detected in the samples did not exceed the regulation value (30 μg/g), 14 kinds of PAAs were detected that exceeded the limit of quantification. 4,4'-Methylenedianiline, in amounts that exceeded the limit of quantification, was detected in 20 textile samples containing synthesis fiber (16 samples made from polyurethane, two samples made from polyester, and two samples made from acryl); however, it was not detected in natural fiber textile samples. Of these samples, 4,4'-methylenedianiline was detected in 16 out of 19 samples (84%) made from polyurethane fiber. This suggests that 4,4'-methylenedianiline is formed from polyurethane. The origin of 3,3'-dichlorobenzidine was investigated in three samples releasing more than 3 μg/g (3.9-15 μg/g) of 3,3'-dichlorobenzidine using atmospheric pressure solids analysis probe-mass spectrometry and Pigment Orange 13 was identified as the orange colorant in the textile printing parts. This result suggests that 3,3'-dichlorobenzidine detected in these three samples was generated by the reduction of Pigment Orange 13.

  5. Influence of beer marinades on the reduction of carcinogenic heterocyclic aromatic amines in charcoal-grilled pork meat.

    Science.gov (United States)

    Viegas, Olga; Moreira, Patrícia S; Ferreira, Isabel M P L V O

    2015-01-01

    The effect of beer marinades on the formation of heterocyclic aromatic amines (HAs) was examined in charcoal-grilled pork. Pilsner, non-alcoholic pilsner and black beers (coded respectively as PB, P0B and BB) were assayed and unmarinated samples cooked under similar conditions provided reference HAs levels. Two thermic (PhIP and 4,8-DiMeIQx) and three pyrolytic HAs (Trp-P-1, AαC, MeAαC) were quantified in unmarinated meat samples. Marinating meat in beer resulted in a significant decrease of PhIP, Trp-P-1 and AαC (p beers reduced total HA formation in charcoal-grilled pork, black beer being the most efficient with a level of 90% inhibition. A strong positive correlation was observed between the inhibitory effect of beer on total HA formation and their antioxidant activity. Beer marinades mitigate the impact of consumption of well-done grilled pork meat reducing the formation of cooking carcinogens.

  6. Heterocyclic aromatic amines in deep fried lamb meat: The influence of spices marination and sensory quality.

    Science.gov (United States)

    S, Jinap; Iqbal, Shahzad Zafar; Talib, Nur Hafiza; Hasnol, N D S

    2016-03-01

    The present study was focused to investigate the effect of selected spices (turmeric, torch ginger, lemongrass and curry leaves) on the formation of heterocyclic amines (HCAs, IQx, MeIQ, MeIQx, DiMeIQx, IQ, harman, norharman, and AαC) in deep fried lamb meat. Meat samples were marinated with optimized levels of turmeric (4 %), 10 % each of torch ginger, lemon grass, curry leaves at medium (70 °C) and well done (80 °C) doneness temperatures. The concentration of HCAs in deep fried meat samples were analysed using LC-MS/MS technique. The results revealed that torch ginger (10 %) has reduced 74.8 % of Me1Qx (1.39 to 0.35 ng/g) at medium doneness, followed by the 64.7 % reduction, using curry leaves and turmeric at medium degree of doneness. Torch ginger has reduced 86.6 % of AαC (2.59 to 0.40 ng/g) at well done doneness. The most prevalence level of HCAs was found in deep fried meat i.e. DiMeIQ (3.69 ng/g) at well done doneness. The sensory evaluation, using a 7 point hedonic test design for colour and texture in deep fried meat samples were resulted in a preferred color of golden brown and slightly tough texture. The use of local spices in marinating of deep fried lamb meat samples will certainly inhibit/reduce the level of these toxic and harmful HCAs.

  7. Heterocyclization Approach for Electrooxidative Coupling of Functional Primary Alkylamines with Aromatics.

    Science.gov (United States)

    Morofuji, Tatsuya; Shimizu, Akihiro; Yoshida, Jun-ichi

    2015-08-12

    A new approach for electrooxidative coupling of aromatic compounds and primary alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary alkylamines. Treatment of primary alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.

  8. A New Methodology for Assessing Macromolecular Click Reactions and Its Application to Amine--Tertiary Isocyanate Coupling for Polymer Ligation.

    Science.gov (United States)

    Gody, Guillaume; Roberts, Derrick A; Maschmeyer, Thomas; Perrier, Sébastien

    2016-03-30

    Click reactions have provided access to an array of remarkably complex polymer architectures. However, the term "click" is often applied inaccurately to polymer ligation reactions that fail to respect the criteria that typify a true "click" reaction. With the purpose of providing a universal way to benchmark polymer-polymer coupling efficiency at equimolarity and thus evaluate the fulfilment of click criteria, we report a simple one-pot methodology involving the homodicoupling of α-end-functionalized polymers using a small-molecule bifunctional linker. A combination of SEC analysis and chromatogram deconvolution enables straightforward quantification of the coupling efficiency. We subsequently employ this methodology to evaluate an overlooked candidate for the click reaction family: the addition of primary amines to α-tertiary isocyanates (α-(t)NCO). Using our bifunctional linker coupling strategy, we show that the amine-(t)NCO reaction fulfills the criteria for a polymer-polymer click reaction, achieving rapid, chemoselective, and quantitative coupling at room temperature without generating any byproducts. We demonstrate that amine-(t)NCO coupling is faster and more efficient than the more common amine-tertiary active ester coupling under equivalent conditions. Additionally, we show that the α-(t)NCO end group is unprecedentedly stable in aqueous media. Thus, we propose that the amine-(t)NCO ligation is a powerful new click reaction for efficient macromolecular coupling.

  9. Gene-diet interactions in exposure to heterocyclic aromatic amines and bulky DNA adduct levels in blood leukocytes.

    Science.gov (United States)

    Ho, Vikki; Peacock, Sarah; Massey, Thomas E; Godschalk, Roger W L; van Schooten, Frederik J; Chen, Jian; King, Will D

    2015-08-01

    Heterocyclic aromatic amines (HAAs), carcinogens produced in meat when cooked at high temperatures, are an emerging biologic explanation for the meat-colorectal cancer relationship. HAAs form DNA adducts; left unrepaired, adducts can induce mutations, which may initiate/promote carcinogenesis. The purpose of this research was to investigate the relationship between dietary HAAs, genetic susceptibility and bulky DNA adduct levels. Least squares regression was used to examine the relationship between dietary HAA exposure and bulky DNA adduct levels in blood measured using (32)P-postlabeling among 99 healthy volunteers. Gene-diet interactions between dietary HAAs and genetic factors relevant to the biotransformation of HAAs and DNA repair were also examined. No main effects of dietary HAAs on bulky DNA adduct levels was found. However, those with the putative NAT1 rapid acetylator phenotype had lower adduct levels than those with the slow acetylator phenotype (P = 0.02). Furthermore, having five or more 'at-risk' genotypes was associated with higher bulky DNA adduct levels (P = 0.03). Gene-diet interactions were observed between NAT1 polymorphisms and dietary HAAs (P adduct levels compared to lower intakes. This study provides evidence of a biologic relationship between dietary HAAs, genetic susceptibility and bulky DNA adduct formation. However, the lack of a strong main effect of HAAs suggests that dietary HAAs are not a large contributor to bulky DNA adducts in this population; future studies should consider relevant gene-diet interactions to clarify the role of HAAs in carcinogenesis.

  10. Determination of Aromatic Amines Using Solid-Phase Microextraction Based on an Ionic Liquid-Mediated Sol-Gel Technique.

    Science.gov (United States)

    Abbasi, Vajihe; Sarafraz-Yazdi, Ali; Amiri, Amirhassan; Vatani, Hossein

    2016-04-01

    A headspace solid-phase microextraction (HS-SPME) method was developed for isolation of monocyclic aromatic amines from water samples followed by gas chromatography-flame ionization detector (GC-FID). In this work, the effect of the presence of ionic liquid (namely, 1-hexyl-3-methyl-imidazolium hexafluorophosphate [C6MIM][PF6]) was investigated in the sol-gel coating solutions on the morphology and extraction behavior of the resulting hybrid organic-inorganic sol-gel sorbents utilized in SPME. Hydroxy-terminated poly(dimethylsiloxane) (PDMS) was used as the sol-gel active organic component for sol-gel hybrid coatings. Two different coated fibers that were prepared are PDMS and PDMS-IL ([C6MIM][PF6]) fibers. Under the optimal conditions, the method detection limits (S/N = 3) with PDMS-IL were in the range of 0.001-0.1 ng/mL and the limits of quantification (S/N = 10) between 0.005 and 0.5 ng/mL. The relative standard deviations for one fiber (n = 5) were obtained from 3.1 up to 8.5% and between fibers or batch to batch (n = 3) in the range of 5.3-10.1%. The developed method was successfully applied to real water and juice fruits samples while the relative recovery percentages obtained for the spiked water samples at 0.1 ng/mL were from 83.3 to 95.0%.

  11. Trace Analysis of Mutagenic Heterocyclic Aromatic Amines in Cigarette Smoke Condensate and its Base Fractions via Silylation-GC-MS

    Directory of Open Access Journals (Sweden)

    Liu S

    2014-12-01

    Full Text Available Among the more than 5000 chemicals reported in cigarette smoke condensate (CSC, heterocyclic aromatic amines (HAAs are considered to be a contributor to observed biological activity. HAAs are non-volatile and are reported at ppb levels in CSC. A new method for HAA analysis at the trace level is reported here. N, O-Bis(trimethylsilyl trifluoroacetamide (BSTFA containing 1% trimethylchlorosilane was employed to derivatize amino groups by heating the reagent containing a sample of CSC at 80 °C for 30 min followed by analysis employing gas chromatography-mass spectroscopy (GC-MS in the selected-ion-monitoring (SIM mode. This derivatization method afforded symmetrical peak shapes on a ZB-50 stationary phase and achieved instrumental limits of quantification (LOQ at 10:1 S/N from -1 ng/mL for AαC to120 ng/mL for Glu-P-1. The chemical identity of each derivative was confirmed by comparison of retention time and mass spectra of standards. The latter were characterized by the following ions: M·+ or [M-1]+, [M-15]+, and m/z 73 (i.e., trimethylsilyl. CSC and its base sub-fractions were studied using the GC-MS method. Ten HAAs were screened and five were quantified in cigarette smoke condensate, while 2-5 HAAs were quantified in each of three base sub-fractions. Values obtained with the new procedure agree well with values reported in the literature and with results obtained from a commercial laboratory via a different analytical method. The potential contribution of each HAA to the overall mutagenic activity observed for CSC and its base fractions is discussed. When considered together, HAAs account for only a small portion (-7.8% of the observed mutagenicity of the CSC.

  12. Rapid determination of six carcinogenic primary aromatic amines in mainstream cigarette smoke by two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Bie, Zhenying; Lu, Wei; Zhu, You; Chen, Yusong; Ren, Hubo; Ji, Lishun

    2017-01-27

    A fully automated, rapid, and reliable method for simultaneous determination of six carcinogenic primary aromatic amines (AAs), including o-toluidine (o-TOL), 2, 6-dimethylaniline (2, 6-DMA), o-anisidine (o-ASD), 1-naphthylamine (1-ANP), 2-naphthylamine (2-ANP), and 4-aminobiphenyl (4-ABP), in mainstream cigarette smoke was established. The proposed method was based on two-dimensional online solid phase extraction combined with liquid chromatography tandem mass spectrometry (SPE/LC-MS/MS). The particulate phase of the mainstream cigarette smoke was collected on a Cambridge filter pad and pretreated via ultrasonic extraction with 2% formic acid (FA), while the gas phase was trapped by 2% FA without pretreatment for determination. The two-dimensional online SPE comprised of two cartridges with different absorption characteristics was applied for sample pretreatment. Analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) under multiple reaction monitoring mode. Each sample required about 0.5h for solid phase extraction and analysis. The limit of detections (LODs) for six AAs ranged from 0.04 to 0.58ng/cig and recoveries were within 84.5%-122.9%. The relative standard deviations of intra- and inter-day tests for 3R4F reference cigarette were less than 6% and 7%, respectively, while no more than 7% and 8% separately for a type of Virginia cigarette. The proposed method enabled minimum sample pretreatment, full automation, and high throughput with high selectivity, sensitivity, and accuracy. As a part of the validation procedure, fifteen brands of cigarettes were tested by the designed method. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Some technological aspects of methane aromatization (direct and via oxidative coupling)

    Energy Technology Data Exchange (ETDEWEB)

    Skutil, Krzysztof; Taniewski, Marian [Silesian Technical University, Chair of Chemical Organic Technology and Petrochemistry, ul. Krzywoustego 4, 44-101 Gliwice (Poland)

    2006-06-15

    The investigations on transformation of methane to benzene and naphthalene have been carried out in aim to verify and supplement earlier reported data and on this basis to estimate real industrial perspectives of the CH{sub 4} aromatization concept, the main challenges and barriers. Methane aromatization (direct and via oxidative coupling) has been studied over Mo/HZSM-5 catalyst used both for direct methane dehydroaromatization and for aromatization of methane oxidative coupling (OCM) products. The effects of Mo content in the catalyst, temperature, space velocity, the presence of CO{sub 2}, CO, H{sub 2}O, C{sub 2}H{sub 4}, C{sub 2}H{sub 6} and their mixtures in the feed have been studied. The effectiveness of the catalyst regeneration in the air was also examined. All results were confronted with the literature data and analyzed from technological point of view. It was confirmed that direct CH{sub 4} aromatization process was characterized by a low CH{sub 4} single-pass conversion, low single-pass yields of the main products (benzene, hydrogen and naphthalene) and a low catalyst stability (rapid catalyst deactivation). Various possible technological schemes were analyzed. It was concluded that real industrial chances of direct methane aromatization or aromatization via OCM would depend largely on the advancement in the cost-effective separation techniques. The methane aromatization concept was also confronted with other methane conversion processes. (author)

  14. Microwave-assisted chemoselective copper-catalyzed amination of o-chloro and o-bromobenzoic acids using aromatic amines under solvent free conditions

    Institute of Scientific and Technical Information of China (English)

    Yaghoub Sarrafi; Manijeh Mohadeszadeh; Kamal Alimohammadi

    2009-01-01

    Copper-catalyzed synthesis of N-aryl anthranilic acid derivatives using effective amination of 2-chloro and 2-bromobenzoic acid under microwave irradiation is reported. Some of the advantages of this method axe high chemoselectivity, short reaction times, ease of work up procedure and elimination of the need for acid protection.

  15. Binding of aromatic amines to the rat hepatic Ah receptor in vitro and in vivo and the 8S and 4S estrogen receptor of rat uterus and rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Cikryt, P.; Kaiser, T.; Gottlicher, M. (Univ. of Wuerzburg (West Germany))

    1990-08-01

    Studies on structurally related aromatic amines with different carcinogenic properties have shown that 2-acetylaminofluorene (2-AAF) and 2-acetylaminophenanthrene (AAP) inhibit the binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the Ah receptor in vitro. The apparent inhibitor constants (K{sub i}) are 2.3 {mu}M for 2-AAF and 2.7 {mu}M for AAP. In contrast, 4-acetylaminofluorene, an isomer of 2-AAF, and trans-4-acetylaminostilbene do not bind to the rat hepatic cytosolic Ah receptor. Pretreating female Wistar rats with 2-AAF or AAP leads to the induction of the P-450 isoenzymes that are under the control of the Ah receptor. Ornithine decarboxylase activity is induced by all aromatic amines tested irrespective of their Ah receptor affinity. The aromatic amines used as model compounds do not inhibit the binding of 17-{beta}-estradiol to the 8S and 4S estrogen receptor of rat uterus or rat liver in a competition assay analyzed using sucrose density gradient centrifugation. On the other hand, the aromatic amines bind to varying extents to another estrogen-binding protein of rat liver whose function and identity is still unknown. The study demonstrates that structurally related aromatic amines in their unmetabolized form interact differentially with a cellular target protein, the Ah receptor, in vitro as well as in vivo. However, a relationship between these effects and the postulated promoting properties of 2-AAF remains to be established.

  16. A base-mediated self-propagative Lossen rearrangement of hydroxamic acids for the efficient and facile synthesis of aromatic and aliphatic primary amines.

    Science.gov (United States)

    Ohtsuka, Naoya; Okuno, Moriaki; Hoshino, Yujiro; Honda, Kiyoshi

    2016-10-14

    A variety of aromatic and aliphatic hydroxamic acids were converted to the corresponding primary amines via base-mediated rearrangement. This rearrangement could proceed with less than 1 equiv. of K2CO3 in polar solvents under thermal conditions with no external reagents. This rearrangement has several features including no external activating agents needed for promoting the rearrangement, less than one equivalent of a base is sufficient for the reaction, and a clean reaction in which only carbon dioxide is produced as a by-product. A self-propagating mechanism via an isocyanate intermediate is proposed and elementary reaction steps, namely, chain propagation reactions are supported by experiments.

  17. Ability of probiotic Lactobacillus casei DN 114001 to bind or/and metabolise heterocyclic aromatic amines in vitro.

    Science.gov (United States)

    Nowak, Adriana; Libudzisz, Zdzislawa

    2009-10-01

    Heterocyclic aromatic amines (HCA) are compounds with high mutagenic potential, formed when meat is cooked at high temperatures of 150-300 degrees C. These compounds contribute to development of colon and gastric cancer. Western diet provides a lot of HCA and influences the available substrates for the intestinal microbiota which can activate HCA to direct acting mutagens. On the other hand, lactic acid bacteria existing in the colon and ingested with food including probiotics, may exert an anti-carcinogenic action, but the mechanism is still poorly understood. In the present study we determined the ability of probiotic Lactobacillus casei DN 114001 (Actimel strain) to metabolise or adsorb three HCA: IQ, MelQx and PhIP in vitro. Lactobacilli were cultivated in MRS and in a modified MRS broth with reduced concentrations of nitrogen and carbon (MRS NC), with addition of 25 mug/ml of IQ, MelQx or PhIP. Their concentration after cultivation with L. casei DN 114001 was measured with high-performance liquid chromatography and the genotoxicity was evaluated by the alkaline comet assay. It was measured, that after 24 h cultivation in MRS (cell density was 10(9) cfu/ml), rapid decrease of IQ and PhIP (98-99%) was observed, and the peaks on chromatograms were almost completely reduced. In case of MeIQx the decrease was about 27%. In a modified MRS broth (cell density was 10(8) cfu/ml), the ability to decrease HCA concentration during prolonged cultivation (to 168 h) depended on the growth phase of bacteria, and it was about 51.5% for IQ and at about 11.2% for MeIQx. Non-growing cells (in phosphate buffer), could reduce the content of IQ and PhIP from 72 h to the end of incubation. L. casei DN 114001 reduced genotoxicity of HCA (IQ from 46 to 48%; MeIQx from 35 to 65% and PhIP from 32 to 81%), and the degree depended on the incubation time, cell growth and the medium used. It may suggest that bacteria can metabolise or adsorb HCA.

  18. Determination of 2,5-toluylenediamine (2,5-TDA) and aromatic amines in urine after personal application of hair dyes: kinetics and doses.

    Science.gov (United States)

    Schettgen, Thomas; Heinrich, K; Kraus, T; Gube, Monika

    2011-02-01

    The personal use of hair dye products is currently under discussion due to the potentially increased risk of bladder cancer among long-time users described in epidemiological literature. In order to investigate the dermal absorption of aromatic diamines as well as aromatic amines possibly present as contaminants in hair dye formulations, we conducted a biomonitoring study under real-life conditions and calculated kinetics and doses for the urinary excretion. Urine samples of two female subjects were collected for a time period of 48 h after personal application of a hair dye cream and analysed for aromatic diamines as well as o-toluidine and 4-aminobiphenyl using highly specific GC/MS-methods. 2,5-Toluylenediamine (2,5-TDA) as active ingredient of hair dyes is rapidly absorbed dermally. After a distribution phase of 12 h, 2,5-TDA is excreted with a half-time of 8 h. Excretion was 90% complete within 24 h after application. The doses of 2,5-TDA excreted within 48 h were 700 μg for application of a brown-reddish hair dye cream and 1.5 mg for the application of a brown-black hair dye cream. Urinary 4-aminobiphenyl as well as contaminations with other aromatic diamines were not detectable in our study. Due to the artifactual formation of o-toluidine in the presence of high concentrations of urinary 2,5-TDA, our results could not prove an increased internal exposure of humans to carcinogenic amines after personal application of hair dyes.

  19. Insights into dehydrogenative coupling of alcohols and amines catalyzed by a (PNN)-Ru(II) hydride complex: unusual metal-ligand cooperation.

    Science.gov (United States)

    Zeng, Guixiang; Li, Shuhua

    2011-11-07

    Density functional theory calculations were performed to elucidate the mechanism of dehydrogenative coupling of primary alcohols and amines mediated by a PNN-Ru(II) hydride complex (PNN = (2-(di-tert-butylphosphinomethyl)-6-(diethylaminomethyl)pyridine)). A plausible reaction pathway was proposed which contains three stages: (1) The alcohol dehydrogenation reaction to generate the aldehyde and H(2); (2) The aldehyde-amine condensation reaction to form the hemiaminal intermediate; (3) The dehydrogenation process of the hemiaminal intermediate to yield the final amide product with the liberation of H(2). The first and third stages occur via a similar pathway: (a) Proton transfer from the substrate to the PNN ligand; (b) Intramolecular rearrangement of the deprotonated substrate to form an anagostic complex; (c) Hydride transfer from the deprotonated substrate to the Ru center to yield the trans-dihydride intermediate and the aldehyde (or amide); (d) Benzylic proton migration from the PNN ligand to the metal center forming a dihydrogen complex and subsequent H(2) liberation to regenerate the catalyst. In all these steps, the metal-ligand cooperation plays an essential role. In proton transfer steps (a) and (d), the metal-ligand cooperation is achieved through the aromatization/dearomatization processes of the PNN ligand. While in steps (b) and (c), their collaboration are demonstrated by the formation of an anagostic interaction between Ru and the C-H bond and two ionic hydrogen bonds supported by the PNN ligand.

  20. Synthesis of carbodiimides by I2/CHP-mediated cross-coupling reaction of isocyanides with amines under metal-free conditions.

    Science.gov (United States)

    Zhu, Tong-Hao; Wang, Shun-Yi; Tao, Yang-Qing; Ji, Shun-Jun

    2015-04-17

    An I2/CHP-mediated cross-coupling reaction of isocyanides with readily accessible amines via C-N formation is described for carbodiimide synthesis in moderate to excellent yields. This represents a metal-free strategy for a coupling reaction of isocyanides with amines, and it provides an efficient approach for symmetric and unsymmetric functionalized carbodiimide derivative synthesis under mild conditions.

  1. Degradation kinetics of peptide-coupled alginates prepared via the periodate oxidation reductive amination route.

    Science.gov (United States)

    Dalheim, Marianne Ø; Ulset, Ann-Sissel T; Jenssen, Ina Beate; Christensen, Bjørn E

    2017-02-10

    Biomaterials based on peptide-coupled alginates must provide both optimal biological environments and tuneable stability/degradation profiles. The present work investigates the degradation pattern and kinetics of peptide-coupled alginates prepared via the periodate oxidation reductive amination route. Alginates degrade slowly (non-enzymatically) under physiological conditions by acid-catalysed hydrolysis and alkali-catalysed β-elimination, both operating simultaneously but dominated by the latter. While periodate oxidation alone largely increases the rate of β-elimination, substitution restores the susceptibility towards β-elimination to that of the parent alginate. For acid hydrolysis the rate of depolymerization is proportional to the degree of substitution, being approximately one order of magnitude larger than the parent alginate, but still lower than for the corresponding materials with fully reduced dialdehydes. Results also suggest a composition-dependent preference for substitution at C2 or C3. These results demonstrate how the various chemistries introduced by the coupling provide useful means to tune the biodegradability profiles.

  2. Species difference among experimental rodents in the activity and induction of cytochrome P-450 isozymes for mutagenic activation of carcinogenic aromatic amines.

    Science.gov (United States)

    Degawa, M; Agatsuma, T; Hashimoto, Y

    1990-12-01

    The expressions of hepatic microsomal cytochrome P-450 isozymes in male rats, mice, hamsters and guinea pigs were studied comparatively with or without an ip injection of a cytochrome P-450 inducer. The activity and quantity of microsomal cytochrome P-450 isozymes were determined respectively by a bacterial mutation assay with Salmonella typhimurium TA98 and immunochemical assays using monoclonal antibodies against rat cytochrome P-450 isozymes. 3-Methoxy-4-aminoazobenzene (3-MeO-AAB), 2-amino-3-methyl-9H-pyrido[2,3-b]indole acetate (MeA alpha C) and 3-methylcholanthrene were used as cytochrome P-450 inducers, and 7 carcinogenic aromatic amines including 3-MeO-AAB and MeA alpha C were used as substrates for the mutation assay. By means of these assays, we examined the species differences among rodents in the activity and induction rate of hepatic cytochrome P-450 isozymes responsible for the mutagenic activation of carcinogenic aromatic amines.

  3. Formation of imines by selective gold-catalysed aerobic oxidative coupling of alcohols and amines under ambient conditions

    DEFF Research Database (Denmark)

    Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie

    2010-01-01

    The formation of imines by aerobic oxidative coupling of mixtures of alcohols and amines was studied using gold nanoparticles supported on titanium dioxide, TiO2, as a heterogeneous catalyst. The reactions were performed at ambient conditions (room temperature and atmospheric pressure) and occurred...

  4. Enantioselective Pinacol Coupling of Aromatic Aldehydes Induced by Chiral Titanium Complexes

    Institute of Scientific and Technical Information of China (English)

    Qing Fang CHENG; Xing You XU; Ming Yan WANG; Jun CHEN; Wei Xing MA; Xu Jie YANG

    2006-01-01

    Asymmetric pinacol coupling of aromatic aldehydes with TiCl4-Zn in the presence of enantiopure squaric acid amidoalcohols afforded 1, 2-diols in excellent yields with high dldiastereoselectivities and enantioselectivities in the range of 46-89% ee. Some factors influencing dl-diastereoselectivity and enantioselectivity were discussed.

  5. Determination of gibberellins in soybean using tertiary amine labeling and capillary electrophoresis coupled with electrochemiluminescence detection.

    Science.gov (United States)

    Zhu, Guimei; Long, Shihua; Sun, Hao; Luo, Wen; Li, Xia; Hao, Zaibin

    2013-12-15

    A novel sensitive method based on tertiary amine labeling for the analysis of gibberellins (GAs) by capillary electrophoresis (CE) coupled with electrochemiluminescence (ECL) detection was proposed. GA3 was tagged with 2-(2-aminoethyl)-1-methylpyrrolidine (AEMP) using N, N'-dicyclohexylcarbodiimide (DCC) and 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (HOOBt) as coupling agents in acetonitrile to produce GA3-AEMP-derivative. The GA3-AEMP-derivative was injected into CE by electrokinetic injection and detected by Ru(bpy)3(2+)-based ECL. The parameters affecting derivatization, detection and separation such as concentration of reactants, detection potential, pH and concentration of separation buffer, were investigated in detail. Under optimum conditions, the linear concentration range for GA3 was from 2.0×10(-7) to 1.28×10(-4)M with a correlation coefficient of 0.9997. The detection limit was 8×10(-8)M (S/N=3). The relative standard deviations of migration time, peak intensity and peak area for nine continuous injections of 2.0×10(-5)M GA3-AEMP-derivative were 1.0%, 2.1% and 4.2%, respectively. The developed approach was successfully applied to the determination of total GAs in the stem, leaf and seed of soybean (Glycine max [L.] Merr.) with recoveries in the range from 89.6% to 99.3%.

  6. Ruthenium-complex catalyzed N-(cyclo)alkylation of aromatic amines with diols. Selective synthesis of N-(n-hydroixyalkyl)anilines of type PhNH(CH2)nOH and of some bioactive arylpiperazines,

    NARCIS (Netherlands)

    Koten, G. van; Abbenhuis, R.A.T.M.; Boersma, J.

    1998-01-01

    A new class of well-defined neutral mono-, and dicationic ruthenium(II) complexes containing a neutral terdentate donor system [C5H3N(CH2E)(2)-2,6] (E = PPh2 (PNP) or NMe2 (NN'N)) has been found effective as catalyst precursor in N-(cyclo)alkylation reactions of aromatic amines with diols

  7. Repair of DNA lesions induced by ultraviolet irradiation and aromatic amines in normal and repair-deficient human lymphoblastoid cell lines

    DEFF Research Database (Denmark)

    Stevnsner, Tinna; Frandsen, Henrik; Autrup, Herman

    1995-01-01

    A host cell reactivation (HCR) assay was employed to study the capacity of a normal and three repair-deficient human lymphoblastoid cell lines to repair DNA damage induced by UV irradiation and the aromatic amines 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and N-acetyl-2-aminofluorene....... In the XP-D cell line, which had practically no DNA repair capacity, AAF adducts had a more potent inhibitory effect on gene expression than UV and PhIP adducts. When corrected for this inhibitory effect, the wild-type, XP-C and CS-B cell lines repaired low levels of AAF and UV adducts with similar...

  8. First Synthesis and Isolation of the E- and Z-Isomers of Some New Schiff Bases. Reactions of 6-Azido-5-Formyl-2-Pyridone with Aromatic Amines

    Directory of Open Access Journals (Sweden)

    Kamal U. Sadek

    2008-01-01

    Full Text Available Some novel Schiff bases have been prepared by reacting 6-azido-5-formyl-2-pyridone 1 with a series of aromatic amines 2a-f. 5-Arylaminomethylene-6-(E-aryliminopyridones3a-e were obtained by reaction of 1 with 2a-e at room temperature,whereas with 2f, the 6-azido-5-naphthalen-2-yl-iminomethylpyridone derivative 4 wasformed. On the other hand, heating 1 with 2a-d at 140-150°C yielded two sets of isomericproducts, (E-3a-d and (Z-5a-d. Refluxing compounds (Z-3a,c with hydroxyl-amine inmethanol gave the corresponding hydroxyliminopyridones 8a,c. Heating of (E-3a-d withexcess POCl3 at reflux did not give the expected tricyclic compound 9, but rather theisomeric products (Z-5a-d were obtained. The structures of all these products have beencharacterized using IR and 1H- and 13C-NMR spectroscopy.

  9. An efficient way to coupling amine with derivatives of steric N-Boc-pyrrolidine-2-carboxylic acid

    Institute of Scientific and Technical Information of China (English)

    Feng Zhi Liu; Hao Fang; Wen Fang Xu

    2007-01-01

    An efficient way to coupling amine with the derivatives of steric N-Boc-pyrrolidine-2-carboxylic acid was reported in this paper.We have found that the synthesis of derivatives is problematic with the commonly used DCC/HOBT method. As a substitute, the mixed anhydride method was adopted. A series of 6-(3-nitroguanidino)hexanamidopyrrolidine derivatives were prepared with this method.

  10. Towards a zero-waste oxidative coupling of nonactivated aromatics by supported gold nanoparticles.

    Science.gov (United States)

    Serna, Pedro; Corma, Avelino

    2014-08-01

    We show that gold nanoparticles are able to perform the direct oxidative coupling of nonactivated aromatics with O2 as the only co-reagent. In this reaction, the aromatic acts both as reactant and solvent. Biphenyl, for example, can be obtained from benzene with high selectivity and a turnover number (TON) of 230 per pass. Similarly, several substituted biaryls can be prepared. Pd performs only one TON and even when a second catalytic functionality is introduced, together with strong acidic conditions, TON is always lower than 100. Other catalysts require iodine for performing the reaction, leading to 2 kg of waste for 1 kg of biphenyl formed, whereas no waste is created by the oxidative coupling with gold nanoparticles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Phase I and phase II reductive metabolism simulation of nitro aromatic xenobiotics with electrochemistry coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Ke; Li, Weiming

    2014-11-01

    Electrochemistry combined with (liquid chromatography) high resolution mass spectrometry was used to simulate the general reductive metabolism of three biologically important nitro aromatic molecules: 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide, and nilutamide. TFM is a pesticide used in the Laurential Great Lakes while niclosamide and nilutamide are used in cancer therapy. At first, a flow-through electrochemical cell was directly connected to a high resolution mass spectrometer to evaluate the ability of electrochemistry to produce the main reduction metabolites of nitro aromatic, nitroso, hydroxylamine, and amine functional groups. Electrochemical experiments were then carried out at a constant potential of -2.5 V before analysis of the reduction products by LC-HRMS, which confirmed the presence of the nitroso, hydroxylamine, and amine species as well as dimers. Dimer identification illustrates the reactivity of the nitroso species with amine and hydroxylamine species. To investigate xenobiotic metabolism, the reactivity of nitroso species to biomolecules was also examined. Binding of the nitroso metabolite to glutathione was demonstrated by the observation of adducts by LC-ESI(+)-HRMS and the characteristics of their MSMS fragmentation. In conclusion, electrochemistry produces the main reductive metabolites of nitro aromatics and supports the observation of nitroso reactivity through dimer or glutathione adduct formation.

  12. Palladium-catalyzed regioselective intramolecular coupling of o-carborane with aromatics via direct cage B-H activation.

    Science.gov (United States)

    Quan, Yangjian; Xie, Zuowei

    2015-03-18

    Palladium-catalyzed intramolecular coupling of o-carborane with aromatics via direct cage B-H bond activation has been achieved, leading to the synthesis of a series of o-carborane-functionalized aromatics in high yields with excellent regioselectivity. In addition, the site selectivity can also be tuned by the substituents on cage carbon atom.

  13. Reliable liquid chromatography-mass spectrometry method for investigation of primary aromatic amines migration from food packaging and during industrial curing of multilayer plastic laminates.

    Science.gov (United States)

    Lambertini, Francesca; Di Lallo, Valentina; Catellani, Dante; Mattarozzi, Monica; Careri, Maria; Suman, Michele

    2014-09-01

    Primary aromatic amines (PAAs) can migrate from packaging into food from different sources such as polyurethanic adhesives used for the manufacture of multilayer films, which may contain residual aromatic isocyanates, or recycled paperboard, because of the presence of azo dyes in the printed paper massively used in the recycling process. In the present work, a reliable analytical method, exploiting a conventional high-performance liquid chromatography-(selected ion monitoring)-mass spectrometry system, for PAAs compliance assessment in food contact materials was developed as an effective alternative to the current standard spectrophotometric one, moving in this way from the screening to the accurate and selective quantitation perspective for the analysis of PAAs both in aqueous and acidic food simulants. The main validation parameters were verified achieving very satisfactory results in terms of linearity range, limit of detection (ranging from 0.1 to 1.0 µg kg(-1)) and quantitation (ranging from 0.1 to 3.6 µg kg(-1)), repeatability and accuracy. Suitability of the method was demonstrated for a wide range of commercial samples, chosen among different producers of the most common used food packaging plastic and paperboard categories and then analyzed to assess the risk related to PAAs migration. Finally, the method was also successfully exploited to monitor the evolution of potential PAAs migration during the industrial curing process of multilayer plastic laminates, prior to their release for delivery to the food industry end user.

  14. One-pot synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines using supported gold and base as catalysts

    DEFF Research Database (Denmark)

    Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie

    2012-01-01

    Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol.......Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol....

  15. Site-specific indolation of proline-based peptides via copper(II)-catalyzed oxidative coupling of tertiary amine N-oxides.

    Science.gov (United States)

    Wu, Xiaowei; Zhang, Dengyou; Zhou, Shengbin; Gao, Feng; Liu, Hong

    2015-08-14

    The first site-specific and purely chemical method for modifying proline-based peptides was developed via a convenient, copper-catalyzed oxidative coupling of tertiary amine N-oxides with indoles. This novel approach features high regioselectivity and diastereoselectivity, mild conditions, and compatibility with various functional groups. In addition, a simplified process was realized in one pot and two steps via in situ oxidative coupling of tertiary amine and indoles.

  16. Effect of smoking regime on aromatic amines yields in mainstream cigarette smoke%抽吸模式对卷烟主流烟气主要芳香胺释放量的影响

    Institute of Scientific and Technical Information of China (English)

    张亮; 陈嘉彬; 孙海峰; 王奕; 刘贤杰; 谢涛; 王芳

    2013-01-01

    为研究抽吸模式对卷烟主流烟气中主要芳香胺释放量的影响,在ISO、Massachusetts和Health Canada这3种抽吸模式下分别抽吸了15种市售卷烟,采用液相色谱-串联质谱(LC-MS/MS)法测定了主流烟气中4种主要芳香胺的释放量。结果表明:①混合型卷烟芳香胺释放量明显高于烤烟型卷烟;②与ISO方案相比,采用Massachusetts或Health Canada抽吸模式,卷烟烟气芳香胺的释放量均显著提高;③抽吸模式的改变对高滤嘴通风率卷烟芳香胺释放量的影响更为显著;④卷烟主流烟气中的焦油含量与芳香胺释放量呈现不明显的相关性。%In order to study the effect of smoking regime on aromatic amines yields in mainstream cigarette smoke, 15 kinds of commercially available cigarette samples were smoked under three smoking regimes: ISO, Massachusetts and Health Canada methods, respectively. Then LC-MS/MS method was applied to test the released amount of four kinds of primary aromatic amines in the mainstream smoke. The results showed that: ① Blended cigarettes released significantly higher amount of aromatic amines than flue-cured counterparts;②Compared with ISO method, the aromatic amines emission content had dramatically increased when Massachusetts method or Health Canada method was adopted;③Transformation of smoking regimes showed a greater impact of high filter ventilation rate cigarettes on the content of released aromatic amines;④The tar and the emission content of aromatic amines in the mainstream smoke presented some inconspicuous correlation.

  17. Identification of cancer chemopreventive isothiocyanates as direct inhibitors of the arylamine N-acetyltransferase-dependent acetylation and bioactivation of aromatic amine carcinogens

    Science.gov (United States)

    Duval, Romain; Xu, Ximing; Bui, Linh-Chi; Mathieu, Cécile; Petit, Emile; Cariou, Kevin; Dodd, Robert H.; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

    2016-01-01

    Aromatic amines (AAs) are chemicals of industrial, pharmacological and environmental relevance. Certain AAs, such as 4-aminobiphenyl (4-ABP), are human carcinogens that require enzymatic metabolic activation to reactive chemicals to form genotoxic DNA adducts. Arylamine N-acetyltransferases (NAT) are xenobiotic metabolizing enzymes (XME) that play a major role in this carcinogenic bioactivation process. Isothiocyanates (ITCs), including benzyl-ITC (BITC) and phenethyl-ITC (PEITC), are phytochemicals known to have chemopreventive activity against several aromatic carcinogens. In particular, ITCs have been shown to modify the bioactivation and subsequent mutagenicity of carcinogenic AA chemicals such as 4-ABP. However, the molecular and biochemical mechanisms by which these phytochemicals may modulate AA carcinogens bioactivation and AA-DNA damage remains poorly understood. This manuscript provides evidence indicating that ITCs can decrease the metabolic activation of carcinogenic AAs via the irreversible inhibition of NAT enzymes and subsequent alteration of the acetylation of AAs. We demonstrate that BITC and PEITC react with NAT1 and inhibit readily its acetyltransferase activity (ki = 200 M−1.s−1 and 66 M−1.s−1 for BITC and PEITC, respectively). Chemical labeling, docking approaches and substrate protection assays indicated that inhibition of the acetylation of AAs by NAT1 was due to the chemical modification of the enzyme active site cysteine. Moreover, analyses of AAs acetylation and DNA adducts in cells showed that BITC was able to modulate the endogenous acetylation and bioactivation of 4-ABP. In conclusion, we show that direct inhibition of NAT enzymes may be an important mechanism by which ITCs exert their chemopreventive activity towards AA chemicals. PMID:26840026

  18. Homoallylic amines by reductive inter- and intramolecular coupling of allenes and nitriles

    Directory of Open Access Journals (Sweden)

    Marija D. Manojlovic

    2011-06-01

    Full Text Available The one-pot hydrozirconation of allenes and nitriles followed by an in situ transmetalation of the allylzirconocene with dimethylzinc or zinc chloride provides functionalized homoallylic amines. An intramolecular version of this process leads to 3-aminotetrahydrofurans and 3-aminotetrahydropyrans.

  19. Capture and separation of CO2 from flue gas by coupling free and immobilized amines

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel system has been proposed for the capture and separation of CO2 from flue gas. In this method, a resin isemployed to regenerate the amine capturing CO2 from flue gas atroom temperatures. The feasibility for the resin to regenerateamines such as MEA, MAE, TEA, and ammonia has been demonstrated. It was also discovered that the resin could be regenerated by hotwater.

  20. Hard-hard coupling assisted anomalous magnetoresistance effect in amine-ended single-molecule magnetic junction

    Science.gov (United States)

    Tang, Y.-H.; Lin, C.-J.; Chiang, K.-R.

    2017-06-01

    We proposed a single-molecule magnetic junction (SMMJ), composed of a dissociated amine-ended benzene sandwiched between two Co tip-like nanowires. To better simulate the break junction technique for real SMMJs, the first-principles calculation associated with the hard-hard coupling between a amine-linker and Co tip-atom is carried out for SMMJs with mechanical strain and under an external bias. We predict an anomalous magnetoresistance (MR) effect, including strain-induced sign reversal and bias-induced enhancement of the MR value, which is in sharp contrast to the normal MR effect in conventional magnetic tunnel junctions. The underlying mechanism is the interplay between four spin-polarized currents in parallel and anti-parallel magnetic configurations, originated from the pronounced spin-up transmission feature in the parallel case and spiky transmission peaks in other three spin-polarized channels. These intriguing findings may open a new arena in which magnetotransport and hard-hard coupling are closely coupled in SMMJs and can be dually controlled either via mechanical strain or by an external bias.

  1. Transition metal-free intramolecular regioselective couplings of aliphatic and aromatic C-H bonds.

    Science.gov (United States)

    Tian, Hua; Yang, Haijun; Zhu, Changjin; Fu, Hua

    2016-01-29

    Cross-dehydrogenative couplings of two different C-H bonds have emerged as an attractive goal in organic synthesis. However, achieving regioselective C-H activation is a great challenge because C-H bonds are ubiquitous in organic compounds. Actually, the regioselective couplings promoted by enzymes are a common occurrence in nature. Herein, we have developed simple, efficient and general transition metal-free intramolecular couplings of alphatic and aromatic C-H bonds. The protocol uses readily available aryl triazene as the radical initiator, cheap K2S2O8 as the oxidant, and the couplings were performed well with excellent tolerance of functional groups. Interestingly, α-carbon configuration of some amino acid residues in the substrates was kept after the reactions, and the couplings for substrates with substituted phenylalanine residues exhibited complete β-carbon diastereoselectivity for induction of the chiral α-carbon. Therefore, the present study should provide a novel strategy for regioselective cross-dehydrogenative couplings of two different C-H bonds.

  2. Development of Enantiospecific Coupling of Secondary and Tertiary Boronic Esters with Aromatic Compounds.

    Science.gov (United States)

    Odachowski, Marcin; Bonet, Amadeu; Essafi, Stephanie; Conti-Ramsden, Philip; Harvey, Jeremy N; Leonori, Daniele; Aggarwal, Varinder K

    2016-08-03

    The stereospecific cross-coupling of secondary boronic esters with sp(2) electrophiles (Suzuki-Miyaura reaction) is a long-standing problem in synthesis, but progress has been achieved in specific cases using palladium catalysis. However, related couplings with tertiary boronic esters are not currently achievable. To address this general problem, we have focused on an alternative method exploiting the reactivity of a boronate complex formed between an aryl lithium and a boronic ester. We reasoned that subsequent addition of an oxidant or an electrophile would remove an electron from the aromatic ring or react in a Friedel-Crafts-type manner, respectively, generating a cationic species, which would trigger 1,2-migration of the boron substituent, creating the new C-C bond. Elimination (preceded by further oxidation in the former case) would result in rearomatization giving the coupled product stereospecifically. Initial work was examined with 2-furyllithium. Although the oxidants tested were unsuccessful, electrophiles, particularly NBS, enabled the coupling reaction to occur in good yield with a broad range of secondary and tertiary boronic esters, bearing different steric demands and functional groups (esters, azides, nitriles, alcohols, and ethers). The reaction also worked well with other electron-rich heteroaromatics and 6-membered ring aromatics provided they had donor groups in the meta position. Conditions were also found under which the B(pin)- moiety could be retained in the product, ortho to the boron substituent. This protocol, which created a new C(sp(2))-C(sp(3)) and an adjacent C-B bond, was again applicable to a range of secondary and tertiary boronic esters. In all cases, the coupling reaction occurred with complete stereospecificity. Computational studies verified the competing processes involved and were in close agreement with the experimental observations.

  3. Development of Enantiospecific Coupling of Secondary and Tertiary Boronic Esters with Aromatic Compounds

    Science.gov (United States)

    2016-01-01

    The stereospecific cross-coupling of secondary boronic esters with sp2 electrophiles (Suzuki–Miyaura reaction) is a long-standing problem in synthesis, but progress has been achieved in specific cases using palladium catalysis. However, related couplings with tertiary boronic esters are not currently achievable. To address this general problem, we have focused on an alternative method exploiting the reactivity of a boronate complex formed between an aryl lithium and a boronic ester. We reasoned that subsequent addition of an oxidant or an electrophile would remove an electron from the aromatic ring or react in a Friedel–Crafts-type manner, respectively, generating a cationic species, which would trigger 1,2-migration of the boron substituent, creating the new C–C bond. Elimination (preceded by further oxidation in the former case) would result in rearomatization giving the coupled product stereospecifically. Initial work was examined with 2-furyllithium. Although the oxidants tested were unsuccessful, electrophiles, particularly NBS, enabled the coupling reaction to occur in good yield with a broad range of secondary and tertiary boronic esters, bearing different steric demands and functional groups (esters, azides, nitriles, alcohols, and ethers). The reaction also worked well with other electron-rich heteroaromatics and 6-membered ring aromatics provided they had donor groups in the meta position. Conditions were also found under which the B(pin)- moiety could be retained in the product, ortho to the boron substituent. This protocol, which created a new C(sp2)–C(sp3) and an adjacent C–B bond, was again applicable to a range of secondary and tertiary boronic esters. In all cases, the coupling reaction occurred with complete stereospecificity. Computational studies verified the competing processes involved and were in close agreement with the experimental observations. PMID:27384259

  4. Physico – Chemical Study of Transition Metal Complexes with Schiff’s Base derived from Naphthaldehyde and Substituted Aromatic Amines

    Directory of Open Access Journals (Sweden)

    Prem Mohan Mishra

    2016-10-01

    Full Text Available In continuation of the previous work here we are going to report stability constant values of transition metals like Cu(II , Ni(II, Co(II and Zn (II with Schiff;s base ligand. Schiff’s base ligands were synthesized by the condensation reaction of Naphthaldehyde with 7- Hydroxy naphthalene – 2 – amine .Nitrate salts of divalent cobalt, nickel, copper and zinc were estimated by usual methods. Ligand was analysed for elements by standard method. pH metric titrations were carried out with the help of digital pH meter and stability constant of complexes of these metals with the ligands synthesized were computed by Irving- Rossotti technique modified by Calvin-Bjerrum. The stability constant values of metals for the given ligand were found to be in the order Cu(II > Ni(II, Co(II > Zn (II. This result is in agreement with the natural order proposed by Irving-William.

  5. Aromatic amines from polyurethane adhesives in food packaging: the challenge of identification and pattern recognition using Quadrupole-Time of Flight-Mass SpectrometryE.

    Science.gov (United States)

    Pezo, Davinson; Fedeli, Mauro; Bosetti, Osvaldo; Nerín, Cristina

    2012-12-05

    Toxic primary aromatic amines (PAAs) are reaction products from residual isocyanates in polyurethane adhesives. The maximum migration level of the total sum of PAAs is 10 ng g(-1) of food. This paper reports on a method for quantification of 18 PAAs by UHPLC-MS/MS that was optimised and applied to a series of industrial laminates prepared from polyurethane adhesives. Non-intentionally added substances (NIAS), impurities and other migrants were identified by Q-TOF/MS(E). A comparison of the quantitative values obtained by the colorimetric method using NEDA and by UHPLC-MS/MS confirmed that the first method can overestimate the quantification of PAAs. This could be attributed to the impurities and other NIAS present in the plastic laminate. Values of R(2) in the analytical characteristics of UHPLC-MS/MS were obtained, the best value being 0.9964 and the most unfavourable 0.7626. The detection limit (LOD) and the quantification limit (LOQ) were 2 pg g(-1) and 7 pg g(-1), respectively. The stability of the PAAs over time in the acidic simulant in contact with the plastic laminate is also reported.

  6. DNA-damaging activity in vivo and bacterial mutagenicity of sixteen aromatic amines and azo-derivatives, as related quantitatively to their carcinogenicity.

    Science.gov (United States)

    Parodi, S; Taningher, M; Russo, P; Pala, M; Tamaro, M; Monti-Bragadin, C

    1981-01-01

    Sixteen aromatic amines and azo-derivatives were studied. They were: benzidine; 2-acetylaminofluorene; 3'-methyl-p-dimethylaminobenzene; o-aminoazo-toluene; p-dimethylaminoazobenzene; 2,4-diamino-toluene; 4,4'-oxydianiline; 2,4-diaminoanisole; 4,4'-methylenedianiline; 2-naphthylamine; Auramine O; Rhodamine B; Ponceau MX; 1-naphthylamine; p-aminoazobenzene and aniline. The compounds were examined for their capability to induce alkaline DNA fragmentation in rat liver after treatment in vivo, for their mutagenicity in the Salmonella strains TA 98 and TA 100, for their acute toxicity and for their carcinogenicity in mice and rats. For each parameter a quantitative potency index was established, and the correlation existing amongst the different parameters investigated. Only mutagenicity in the strain TA 98 was slightly correlated with carcinogenic potency (r = 0.408). DNA fragmentation and toxicity were not correlated with carcinogenicity. A significant correlation was found between DNA fragmentation and toxicity (r = 0.539). No correlation was found between DNA fragmentation and mutagenicity. The lack of correlation between DNA fragmentation and carcinogenicity is in contrast with previous results obtained with a family of hydrazine derivatives (12) and a group of nitrosocompounds (22). For these two groups of chemicals correlation between DNA fragmentation and carcinogenicity existed, but not between carcinogenicity and mutagenicity in the Ames' test. It is suggested that short term tests can perform very differently for different classes of chemicals.

  7. Preparation and characterization of magnetic Wells-Dawson heteropoly acid nanoparticles for magnetic solid-phase extraction of aromatic amines in water samples.

    Science.gov (United States)

    Amiri, Amirhassan; Saadati-Moshtaghin, Hamid Reza; Zonoz, Farokhzad Mohammadi; Targhoo, Azadeh

    2017-02-03

    In this work, aminopropyl modified silica-coated magnetite nanoparticles with Wells-Dawson heteropoly acid (P2W17Fe@APSCMNPs) was first synthesized and underwent highly efficient magnetic solid-phase extraction (MSPE) of aromatic amines from aqueous samples. The resulted nanomaterials were characterized with different physicochemical techniques such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). Aniline, N,N-dimethylaniline, o-toluidine and 3-chloroaniline were selected as target compounds. The sample quantification was carried out using gas chromatography-flame ionization detector (GC-FID). Under optimal working conditions, the developed method showed good linearity (R>0.9912) in the range of 0.01-100ngmL(-1). The method displays detection limits (at an S/N ration of 3) in the range from 0.003 to 0.01ngmL(-1), and the limits of quantification (at an S/N ratio of 10) are between 0.01 and 0.04ngmL(-1). The enrichment factors (EFs) were in the range of 75-113. Relative standard deviations (RSDs) are 4.8-8.3%. The applicability of the developed method was examined by analyzing different water samples (river water, tap water, well water and wastewater) and the relative recovery values for the spiked water samples were found to be in the range of 90.7-99.8%.

  8. Formation of Heterocyclic Aromatic Amines and Migration Level of Bisphenol-A in Sous-Vide-Cooked Trout Fillets at Different Cooking Temperatures and Cooking Levels.

    Science.gov (United States)

    Oz, Fatih; Seyyar, Esra

    2016-04-20

    The effects of different cooking temperatures (65, 75, and 85 °C) and cooking levels (medium and well) on some quality properties, the formation of heterocyclic aromatic amines (HCAs), and the migration level of bisphenol-A (BPA) in trout fillets cooked by sous-vide were investigated. As a result, as expected, cooking caused a reduction in water content of the samples, whereas pH, TBARS, L*, and b* values increased. Cooking loss values ranged between 14.78 and 20.51%. Whereas IQ, MeIQ, 7,8-DiMeIQx, 4,8-DiMeIQx, PhIP, AαC and MeAαC could not be detected in the analyzed samples, varying levels of IQx (up to 0.16 ng/g) and MeIQx (up to 5.66 ng/g) were detected. It was determined that total HCA amounts ranged between 1.28 and 5.75 ng/g, and all or a big part of the total HCAs belonged to MeIQx. In addition, the migration level of BPA in sous-vide-cooked samples ranged between 4.93 and 27.11 ng/g.

  9. [Determination of carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Wen, Yuyun; Ou, Yan; He, Mingchao; Gong, Zhenbin

    2013-04-01

    A rapid determination method was developed for the quantification and confirmation of 22 carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem electrospray ionization mass spectrometry (UHPLC-MS/MS). The methods of EN 14362-1:2012 (for textiles) and ISO 17234-1:2010 (for leather) were adopted for sample pretreatment, finally diluted with methanol. The target compounds were separated by an Eclipse XDB-C18 RRHD column and eluted with methanol and water in gradient, and then determined by positive electrospray ionization mass spectrometry under multiple reaction monitoring (MRM) mode. The external standard method was used for the quantitative analysis. The separation conditions, fragment voltages, collision energies, etc. were optimized. The limits of quantification (LOQ) were below 0.2 mg/kg for different compounds, matrix spike recoveries ranged from 70% to 120% at the spiked levels of 500, 1 000 and 1 500 microg/L, and the relative standard deviations (RSDs) were less than 15%. The proposed method is rapid, sensitive, accurate and selective.

  10. Silicon Amine Reagents for the Photocatalytic Synthesis of Piperazines from Aldehydes and Ketones.

    Science.gov (United States)

    Hsieh, Sheng-Ying; Bode, Jeffrey W

    2016-05-06

    Silicon amine protocol (SLAP) reagents for photocatalytic cross-coupling with aldehydes and ketones to form N-unprotected piperazines have been developed. This blue light promoted process tolerates a wide range of heteroaromatic, aromatic, and aliphatic aldehydes and structurally and stereochemically complex SLAP reagents. It provides a tin-free alternative to SnAP (tin amine protocol) reagents for the synthesis of substituted piperazines.

  11. New Stable Cu(I) Catalyst Supported on Weakly Acidic Polyacrylate Resin for Green C-N Coupling: Synthesis of N-(Pyridin-4-yl)benzene Amines and N,N-Bis(pyridine-4-yl)benzene Amines.

    Science.gov (United States)

    Kore, Nitin; Pazdera, Pavel

    2016-12-22

    A method for preparation of a new stable Cu(I) catalyst supported on weakly acidic polyacrylate resin without additional stabilizing ligands is described. A simple and efficient methodology for Ullmann Cu(I) catalyzed C-N cross coupling reactions using this original catalyst is reported. Coupling reactions of 4-chloropyridinium chloride with anilines containing electron donating (EDG) or electron withdrawing (EWG) groups, naphthalen-2-amine and piperazine, respectively, are successfully demonstrated.

  12. New Stable Cu(I Catalyst Supported on Weakly Acidic Polyacrylate Resin for Green C-N Coupling: Synthesis of N-(Pyridin-4-ylbenzene Amines and N,N-Bis(pyridine-4-ylbenzene Amines

    Directory of Open Access Journals (Sweden)

    Nitin Kore

    2016-12-01

    Full Text Available A method for preparation of a new stable Cu(I catalyst supported on weakly acidic polyacrylate resin without additional stabilizing ligands is described. A simple and efficient methodology for Ullmann Cu(I catalyzed C-N cross coupling reactions using this original catalyst is reported. Coupling reactions of 4-chloropyridinium chloride with anilines containing electron donating (EDG or electron withdrawing (EWG groups, naphthalen-2-amine and piperazine, respectively, are successfully demonstrated.

  13. Metal-Mediated Couplings of Primary Alcohols with Amines and Carbohydrates

    DEFF Research Database (Denmark)

    Maggi, Agnese; Madsen, Robert

    -O-glycosylations of unprotected phenyl 1-thioglycopyranosides Chemical glycosylation is of outstanding importance to access biologically relevant carbohydrate structures, but classical methods suffer from the disadvantage of extensive protecting group manipulations. Thus, approaches to reduce......The work presented in this thesis was performed at the Department of Chemistry of the Technical University of Denmark during a three year Ph.D. program. The thesis involves two distinct Projects related to organometallic and carbohydrate chemistry. Project 1: Dehydrogenative synthesis of imines...... from alcohols and amines catalyzed by a ruthenium N-heterocyclic carbene complex. The successful method development and application of a convenient and direct (one step) synthesis of imines from alcohols and amines is described. The developed method provides quick andextended access to structurally...

  14. Flight and walking in locusts-cholinergic co-activation, temporal coupling and its modulation by biogenic amines.

    Science.gov (United States)

    Rillich, Jan; Stevenson, Paul A; Pflueger, Hans-Joachim

    2013-01-01

    Walking and flying in locusts are exemplary rhythmical behaviors generated by central pattern generators (CPG) that are tuned in intact animals by phasic sensory inputs. Although these two behaviors are mutually exclusive and controlled by independent CPGs, leg movements during flight can be coupled to the flight rhythm. To investigate potential central coupling between the underlying CPGs, we used the muscarinic agonist pilocarpine and the amines octopamine and tyramine to initiate fictive flight and walking in deafferented locust preparations. Our data illustrate that fictive walking is readily evoked by comparatively lower concentrations of pilocarpine, whereas higher concentrations are required to elicit fictive flight. Interestingly, fictive flight did not suppress fictive walking so that the two patterns were produced simultaneously. Frequently, leg motor units were temporally coupled to the flight rhythm, so that each spike in a step cycle volley occurred synchronously with wing motor units firing at flight rhythm frequency. Similarly, tyramine also induced fictive walking and flight, but mostly without any coupling between the two rhythms. Octopamine in contrast readily evoked fictive flight but generally failed to elicit fictive walking. Despite this, numerous leg motor units were recruited, whereby each was temporarily coupled to the flight rhythm. Our results support the notion that the CPGs for walking and flight are largely independent, but that coupling can be entrained by aminergic modulation. We speculate that octopamine biases the whole motor machinery of a locust to flight whereas tyramine primarily promotes walking.

  15. Flight and walking in locusts-cholinergic co-activation, temporal coupling and its modulation by biogenic amines.

    Directory of Open Access Journals (Sweden)

    Jan Rillich

    Full Text Available Walking and flying in locusts are exemplary rhythmical behaviors generated by central pattern generators (CPG that are tuned in intact animals by phasic sensory inputs. Although these two behaviors are mutually exclusive and controlled by independent CPGs, leg movements during flight can be coupled to the flight rhythm. To investigate potential central coupling between the underlying CPGs, we used the muscarinic agonist pilocarpine and the amines octopamine and tyramine to initiate fictive flight and walking in deafferented locust preparations. Our data illustrate that fictive walking is readily evoked by comparatively lower concentrations of pilocarpine, whereas higher concentrations are required to elicit fictive flight. Interestingly, fictive flight did not suppress fictive walking so that the two patterns were produced simultaneously. Frequently, leg motor units were temporally coupled to the flight rhythm, so that each spike in a step cycle volley occurred synchronously with wing motor units firing at flight rhythm frequency. Similarly, tyramine also induced fictive walking and flight, but mostly without any coupling between the two rhythms. Octopamine in contrast readily evoked fictive flight but generally failed to elicit fictive walking. Despite this, numerous leg motor units were recruited, whereby each was temporarily coupled to the flight rhythm. Our results support the notion that the CPGs for walking and flight are largely independent, but that coupling can be entrained by aminergic modulation. We speculate that octopamine biases the whole motor machinery of a locust to flight whereas tyramine primarily promotes walking.

  16. Determination of primary aromatic amines in cold water extract of coloured paper napkin samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yavuz, Oguzhan; Valzacchi, Sandro; Hoekstra, Eddo; Simoneau, Catherine

    2016-06-01

    The aim of this study was the optimisation of a multi-analyte method for the analysis of primary aromatic amines (PAAs) from napkins in order to support official controls and food safety. We developed a UHPLC-MS/MS method for the simultaneous determination of 36 toxicologically relevant PAAs for paper and board. Good regression coefficients of the calibration curves in a range of 0.992-0.999 and reproducibilities in a range of 2.3-15% were obtained. Limits of detections (LODs) were in the range of 0.03-1.4 µg l(-1) and recoveries were in a range of 21-110% for all the amines. A total of 93 coloured paper napkin samples from different European countries were bought and extracted with water to determine the PAAs. The results showed that 42 of 93 samples contained at least one PAA. More than half of the detected PAAs are considered as toxic, carcinogenic or probably carcinogenic to humans by the International Agency for Research on Cancer (IARC), or are classified as such in the European Union legislation on chemicals. Summed concentrations of PAAs in seven samples were higher than 10 µg l(-1), the limit of summed PAA in the European Union plastic food contact material regulation. Also, eight PAAs, classified as Category 1A and 1B carcinogen in the European Union legislation of chemicals, were detected at concentrations higher than 2 µg l(-1), exceeding the limit proposed by the Federal Institute for Risk Assessment in Germany. Aniline (n = 14) was most frequently present in higher concentrations followed by o-toluidine, o-anisidine, 2,4-dimethylaniline and 4-aminoazobenzene. Red, orange, yellow and multicoloured paper napkins contained the highest concentrations of total PAAs (> 10 µg l(-1)). Although the European Union has not harmonised the legislation of paper and board materials and, thus, there is no specific migration limit for PAAs from paper napkins, the present study showed that coloured paper napkins can contain toxic and carcinogenic PAAs at

  17. Characterisation of Leather Candidate Certified Reference Materials for their Mass Fractions of Aromatic Amines%用于分析皮革样本中芳香胺含量的检定标准物质的表征(续)

    Institute of Scientific and Technical Information of China (English)

    Jan-Willem Wegener; Haiko Schulz; 龚英

    2011-01-01

    Three batches of leather samples were colored with nine azo dyes that can yield eight proven or suspected carcinogenic aromatic amines under reduction conditions.The samples were milled to grains and bottled in jars.A group of five laboratories has established the mass fraction of the amines in a ring test using different analytical methods.The methods included a reduction step in order to cleave the azo dyes into the aromatic amines.Quantification was by standard addition: sub - samples of the leathers were spiked with known amounts of azo dyes of known purity.It was possible to establish the mass fractions of six of the eight aromatic amines in three of the leather samples.%用9种已经确认或被怀疑的在还原条件下将生成8种致癌芳香胺的染料,对3批皮革样品染色.将皮革样品切碎为颗粒后,装入到广口瓶中.由5个实验室组成的试验组,在环试验中采用不同方法分析这些芳香胺在皮革中所占的质量分数.这些分析方法均包括还原步骤,即,使偶氮染料裂解为芳香胺.采用向皮革子样本加入已知量的且已知纯度的偶氮染料这种标准加入法,进行定量分析.在这3批皮革样品中,可以对这8类芳香胺中的6种进行质量含量的分析.

  18. Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Wang, Xianli; Kang, Haiyan; Wu, Junfeng

    2016-05-01

    Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water.

  19. Optimised extraction of heterocyclic aromatic amines from blood using hollow fibre membrane liquid-phase microextraction and triple quadrupole mass spectrometry.

    Science.gov (United States)

    Cooper, Kevin M; Jankhaikhot, Natcha; Cuskelly, Geraldine

    2014-09-05

    Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of proteinaceous foods, particularly meat. To assist in the ongoing search for biomarkers of HCA exposure in blood, a method is described for the extraction from human plasma of the most abundant HCAs: 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (and its isomer 7,8-DiMeIQx), using hollow fibre membrane liquid-phase microextraction. This technique employs 2.5cm lengths of porous polypropylene fibres impregnated with organic solvent to facilitate simultaneous extraction from an alkaline aqueous sample into a low volume acidic acceptor phase. This low cost protocol is extensively optimised for fibre length, extraction time, sample pH and volume. Detection is by UPLC-MS/MS using positive mode electrospray ionisation with a 3.4min runtime, with optimum peak shape, sensitivity and baseline separation being achieved at pH 9.5. To our knowledge this is the first description of HCA chromatography under alkaline conditions. Application of fixed ion ratio tolerances for confirmation of analyte identity is discussed. Assay precision is between 4.5 and 8.8% while lower limits of detection between 2 and 5pg/mL are below the concentrations postulated for acid-labile HCA-protein adducts in blood.

  20. Dispersive micro-solid phase extraction of aromatic amines based on an efficient sorbent made from poly(1,8-diaminonaphtalen) and magnetic multiwalled carbon nanotubes composite.

    Science.gov (United States)

    Jalilian, Niloofar; Ebrahimzadeh, Homeira; Asgharinezhad, Ali Akbar

    2017-05-26

    In this work, the extraction of aromatic amines with an efficient magnetic multiwalled carbon nanotubes/Fe3O4@Poly(1,8-diaminonaphtalen) (MWCNTs/Fe3O4@PDAN) composite followed by HPLC-DAD was presented. Imprimis, the comparison among different magnetic nanosorbents including Fe3O4, MWCNTs/Fe3O4, Fe3O4@PDAN and MWCNTs/Fe3O4@PDAN was conducted. The obtained results, exhibited that the MWCNTs/Fe3O4@PDAN composite has the highest extraction efficiency for target analytes (3-nitroaniline, 4-chloroaniline, 4-bromoaniline and 3,4-dichloroaniline). This sorbent was characterized by Fourier transform infrared spectroscopy, X-ray dispersive spectroscopy, thermogravimetry analysis, scanning electron microscopy, transition electron microscopy, vibrating sample magnetometry and X-ray diffraction. Design of experiment approach was applied to find out the optimal experimental conditions. The optimal extraction conditions were: pH of the sample, 10; sorbent amount, 10mg; sorption time, 15min; salt concentration, 10% w/w; type and volume of the eluent, 0.01molL(-1) HCl in acetonitrile, 145μL; elution time; 2min. Under the optimal extraction conditions detection limits and linear dynamic ranges were achieved in the range of 0.1-0.25μgL(-1) and 0.25-500μgL(-1), respectively. The percent of extraction recovery and relative standard deviations (n=5) were in the range of 31.2-82.8% and 3.4-5.6%, respectively. Finally, the applicability of the method was successfully confirmed by the extraction and determination of target analytes in various water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Combined genotoxic effects of a polycyclic aromatic hydrocarbon (B(aP and an heterocyclic amine (PhIP in relation to colorectal carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Emilien L Jamin

    Full Text Available Colorectal neoplasia is the third most common cancer worldwide. Environmental factors such as diet are known to be involved in the etiology of this cancer. Several epidemiological studies have suggested that specific neo-formed mutagenic compounds related to meat consumption are an underlying factor involved in the association between diet and colorectal cancer. Heterocyclic amines (HCAs and polycyclic aromatic hydrocarbons (PAHs are known mutagens and possible human carcinogens formed at the same time in meat during cooking processes. We studied the genotoxicity of the model PAH benzo(apyrene (B(aP and HCA 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, alone or in mixture, using the mouse intestinal cell line Apc(Min/+, mimicking the early step of colorectal carcinogenesis, and control Apc(+/+ cells. The genotoxicity of B(aP and PhIP was investigated using both cell lines, through the quantification of B(aP and PhIP derived DNA adducts, as well as the use of a genotoxic assay based on histone H2AX phosphorylation quantification. Our results demonstrate that heterozygous Apc mutated cells are more effective to metabolize B(aP. We also established in different experiments that PhIP and B(aP were more genotoxic on Apc (Min/+ cells compared to Apc (+/+ . Moreover when tested in mixture, we observed a combined genotoxicity of B(aP and PhIP on the two cell lines, with an increase of PhIP derived DNA adducts in the presence of B(aP. Because of their genotoxic effects observed on heterozygous Apc mutated cells and their possible combined genotoxic effects, both B(aP and PhIP, taken together, could be implicated in the observed association between meat consumption and colorectal cancer.

  2. Rapid and simultaneous analysis of ten aromatic amines in mainstream cigarette smoke by liquid chromatography/electrospray ionization tandem mass spectrometry under ISO and "Health Canada intensive" machine smoking regimens.

    Science.gov (United States)

    Xie, Fuwei; Yu, Jingjing; Wang, Sheng; Zhao, Ge; Xia, Qiaoling; Zhang, Xiaobing; Zhang, Shusheng

    2013-10-15

    Ten primary aromatic amines (AAs) in mainstream cigarette smoke under both ISO and "Health Canada intensive" machine smoking regimens were determined in this work, which were suspected to be carcinogenic compounds. The measured AAs included aniline, ortho-toluidine, meta-toluidine, para-toluidine, 1-naphthylamine, 2-naphthylamine, 3-aminobiphenyl, 4-aminobiphenyl, meta-phenylenediamine and meta-anisidine. For rapidly and sensitively analyzing these AAs, a liquid chromatography-electrospray ionization tandem mass spectrometric (LC-MS/MS) method coupled with solid phase extraction (SPE) was developed. The particulate phase of mainstream cigarette smoke was collected on a Cambridge filter pads, while the gas phase was trapped by 25 mL 5% HCl solution. Then, the pad was extracted in an ultrasonic bath with the impinger HCl solution. After being neutralized with NaOH, the extract was purified with a HLB solid phase extraction column, and then was analyzed with LC-MS/MS using isotope-labeled internal standard. The overall sample pretreatment and analysis time was less than 1.5h. The limits of detection for all targets ranged from 0.05 ng cig(-1) to 0.96 ng cig(-1) with the recoveries in the range of 75.0-131.8%. And the intra-day and inter-day precisions were less than 10% and 16%, respectively. Under HCI machine smoking regimen, the AAs yields in mainstream cigarette smoke were much higher and the average increases were greater than 100% compared with those under ISO smoking condition.

  3. Nickel-catalyzed cross-coupling reactions of benzylic zinc reagents with aromatic bromides, chlorides and tosylates.

    Science.gov (United States)

    Schade, Matthias A; Metzger, Albrecht; Hug, Stephan; Knochel, Paul

    2008-07-14

    Benzylic zinc reagents prepared by direct insertion of zinc to benzylic chlorides in the presence of LiCl undergo smooth cross-coupling reactions with aromatic chlorides, bromides and tosylates using Ni(acac)(2) and PPh(3) as a catalyst system.

  4. N,N-Dimethylbenzimidazolium iodide as a green catalyst for cross-coupling of aromatic aldehydeswith unactivated imines

    Directory of Open Access Journals (Sweden)

    Viwat Hahnvajana wong

    2016-03-01

    Full Text Available Cross-coupling of aromatic aldehydes with unactivated iminescatalyzed by N,N-dimethylbenzimidazolium iodide in ethanolic sodium hydroxide solution gave α-amino ketonesin satisfactory yields. Benzoin condensation and further oxidation of the resulted aroins also occurred as side reactions.

  5. Cu(OAc)2 catalyzed Sonogashira cross-coupling reaction in amines

    Institute of Scientific and Technical Information of China (English)

    Sheng Mei Guo; Chen Liang Deng; Jin Heng Li

    2007-01-01

    A simple Cu(OAc)2 catalyzed Sonogashira coupling protocol is presented. It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired products in moderate to excellent yields, using Cu(OAc)2 as the catalyst and Et3N as the solvent.

  6. A two-dimensional conjugated aromatic polymer via C-C coupling reaction

    Science.gov (United States)

    Liu, Wei; Luo, Xin; Bao, Yang; Liu, Yan Peng; Ning, Guo-Hong; Abdelwahab, Ibrahim; Li, Linjun; Nai, Chang Tai; Hu, Zhi Gang; Zhao, Dan; Liu, Bin; Quek, Su Ying; Loh, Kian Ping

    2017-06-01

    The fabrication of crystalline 2D conjugated polymers with well-defined repeating units and in-built porosity presents a significant challenge to synthetic chemists. Yet they present an appealing target because of their desirable physical and electronic properties. Here we report the preparation of a 2D conjugated aromatic polymer synthesized via C-C coupling reactions between tetrabromopolyaromatic monomers. Pre-arranged monomers in the bulk crystal undergo C-C coupling driven by endogenous solid-state polymerization to produce a crystalline polymer, which can be mechanically exfoliated into micrometre-sized lamellar sheets with a thickness of 1 nm. Isothermal gas-sorption measurements of the bulk material reveal a dominant pore size of ~0.6 nm, which indicates uniform open channels from the eclipsed stacking of the sheets. When employed as an organic anode in an ambient-temperature sodium cell, the material allows a fast charge/discharge of sodium ions, with impressive reversible capacity, rate capability and stability metrics.

  7. 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.

  8. Di(1-benzo[][1,2,3]triazol-1-yl)methane: An efficient ligand for copper and amine-free palladium-catalysed Sonogashira coupling reaction

    Indian Academy of Sciences (India)

    Jaspal Singh; Akhilesh Kumar Verma

    2011-11-01

    An efficient Pd-catalysed Sonogashira coupling reaction was achieved in the absence of copper and amine with inorganic base using phosphene-free, air stable di(1-benzo[][1,2,3]triazol-1-yl)methane as ligand. The cross coupling of electron-rich, electron-defficient and hindered aryl halides with terminal alkynes afforded the internal alkynes in good to excellent yields.

  9. Ultrafast proton coupled electron transfer (PCET dynamics in 9-anthranol-aliphatic amine system

    Directory of Open Access Journals (Sweden)

    Nibbering Erik T. J.

    2013-03-01

    Full Text Available Femtosecond infrared absorption studies strongly suggest that photoexcited 9-anthranol takes part in an ultrafast electron transfer (ET reaction in electron-donating triethylamine solvent, but that ultrafast proton coupled electron transfer (PCET occurs in diethylamine solvent.

  10. Sensitive Detection of Aromatic Hydrophobic Compounds in Water and Perfluorooctane Sulfonate in Human Serum by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS) with Amine Functionalized Graphene-Coated Cobalt Nanoparticles.

    Science.gov (United States)

    Nakai, Keisuke; Kawasaki, Hideya; Yamamoto, Atsushi; Arakawa, Ryuichi; Grass, Robert N; Stark, Wendelin J

    2014-01-01

    In this article, we describe the application of surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) with the use of amine functionalized graphene-coated cobalt nanoparticles (CoC-NH2 nanoparticles) to analyse aromatic hydrophobic compounds that are known environmental contaminants, including polycyclic aromatic hydrocarbons (PAHs) and pentachlorophenol (PCP). Our results demonstrated that SALDI-MS can detect PCP, anthracene, and pyrene in water. In particular, the CoC-NH2 nanoparticles proved to be an efficient means of capturing PCP in water because of the high adsorption capacity of the nanoparticles for PCP, which resulted in a detectability of 100 ppt. Furthermore, the CoC-NH2 nanoparticles also functioned as an adsorbent for solid-phase extraction of perfluorooctane sulfonate (PFOS) from human serum, displaying good performance with a detectability of 10 ppb by SALDI-MS.

  11. Direct determination of rate constants for coupling between aromatic radical anions and alkyl and benzyl radicals by laser-flash photolysis

    DEFF Research Database (Denmark)

    Lund, T.; Christensen, P.; Wilbrandt, Robert Walter

    2003-01-01

    Coupling rates between the radicals methyl, n-, sec-, tert-butyl and benzyl (R-.) and the aromatic radical anions of 1,4-dicyanonaphthalene, 9,10-dicyanoanthracene and fluorenone (A(-.)) have been obtained using a new laser-flash photolysis method. The radicals R-. and the radical anions A(-.) were...... generated by a photoinduced electron transfer reaction between the aromatic compound A and the alkyl or benzyl triphenylborate anion RB(Ph)(3)(-). For the first time the rate constants of the coupling reaction between methyl and benzyl radicals with aromatic radical anions have been obtained. For all...... of the radicals and the structure and standard potentials of the aromatic radical anions....

  12. Magnetic solid phase extraction using gold immobilized magnetic mesoporous silica nanoparticles coupled with dispersive liquid-liquid microextraction for determination of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Mehdinia, Ali; Khojasteh, Esmail; Baradaran Kayyal, Tohid; Jabbari, Ali

    2014-10-17

    An efficient magnetic sorbent was introduced for solid phase extraction by incorporation of the gold nanoparticles into the hexagonal lattice of magnetic MCM-41. For the effective incorporation of the gold nanoparticles, magnetic MCM-41 was functionalized with 3-aminopropyltriethoxysilane (APTES), which then interacted with Au atoms through the amine groups. Furthermore, to achieve high pre-concentration factors (PFs), the method was coupled with dispersive liquid-liquid microextraction (DLLME) procedure. Polycyclic aromatic hydrocarbons (PAHs) were used as the model compounds to evaluate the extraction performance of the proposed method. The π-system of PAH compounds and immobilized Au atoms on the surface of the sorbent can cause the electron donor-acceptor interactions. The parameters affecting extraction recovery such as types of the disperser and extraction solvents, pH of the sample solution, and the extraction time were optimized. Under the optimized conditions, the high PFs were obtained in the range 5519-6271 for the target analytes. The kinetic adsorption illustrated that 5 min was sufficient to achieve adsorption equilibrium for PAHs. The evaluations also showed a linearity range 0.01-50 μg L(-1) with the detection limit in the range 0.002-0.004 μg L(-1) for the PAHs. The applicability of the method for the analysis of PAHs in real samples was justified by the extraction of PAHs from seawater samples. The results indicated good recovery efficiencies ranging from 91.4 to 104.2%.

  13. Nonadiabatic dynamics of photoinduced proton-coupled electron transfer in a solvated phenol-amine complex.

    Science.gov (United States)

    Goyal, Puja; Schwerdtfeger, Christine A; Soudackov, Alexander V; Hammes-Schiffer, Sharon

    2015-02-12

    Photoinduced concerted electron-proton transfer (EPT), denoted photo-EPT, is important for a wide range of energy conversion processes. Transient absorption and Raman spectroscopy experiments on the hydrogen-bonded p-nitrophenylphenol-t-butylamine complex, solvated in 1,2-dichloroethane, suggested that this complex may undergo photo-EPT. The experiments probed two excited electronic states that were interpreted as an intramolecular charge transfer (ICT) state and an EPT state. Herein mixed quantum mechanical/molecular mechanical nonadiabatic surface hopping dynamics is used to investigate the relaxation pathways following photoexcitation. The potential energy surface is generated on the fly with a semiempirical floating occupation molecular orbital complete active space configuration interaction method for the solute molecule and a molecular mechanical force field for the explicit solvent molecules. The free energy curves along the proton transfer coordinate illustrate that proton transfer is thermodynamically and kinetically favorable on the lower-energy excited state but not on the higher-energy excited state, supporting the characterization of these states as EPT and ICT, respectively. The nonadiabatic dynamics simulations indicate that the population decays from the ICT state to the EPT state in ∼100 fs and from the EPT state to the ground state on the slower time scale of ∼1 ps, qualitatively consistent with the experimental measurements. For ∼54% of the trajectories, the proton transfers from the phenol to the amine in ∼400 fs on the EPT state and then transfers back to the phenol rapidly upon decay to the ground state. Thus, these calculations augment the original interpretation of the experimental data by providing evidence of proton transfer on the EPT state prior to decay to the ground state. The fundamental insights obtained from these simulations are also relevant to other photo-EPT processes.

  14. Stereodivergent Coupling of Aldehydes and Alkynes via Synergistic Catalysis Using Rh and Jacobsen's Amine.

    Science.gov (United States)

    Cruz, Faben A; Dong, Vy M

    2017-01-25

    We report an enantioselective coupling between α-branched aldehydes and alkynes to generate vicinal quaternary and tertiary carbon stereocenters. The choice of Rh and organocatalyst combination allows for access to all possible stereoisomers with high enantio-, diastereo-, and regioselectivity. Our study highlights the power of catalysis to activate two common functional groups and provide access to divergent stereoisomers and constitutional structures.

  15. Reaction of 5-amino-8-hydroxy-1,4 naphthoquinone with aliphatic and aromatic amines. Theoretical study of its tantomeric equilibria and reactivity; Reaccion de la 5-amino-8-hidroxi-1,4-naftoquinona con aminas alifaticas y aromaticas. Estudio teorico de su equilibrio tantomerico y reactividad

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, F.C. [Departamento de Quimica Organica, Instituto de Quimica UFRGS Porto Alegre (Brazil); Sanchez Alonso, F.; Stefani, V. [Instituto de Quimica Organica General, CSIC, Madrid (Spain)

    1995-12-31

    The reaction of 5-amino-8-hydroxy-1,4-naphthoquinone (1) with aliphatic and aromatic amines have been studied, in absence or present of copper (II) salts, in order to prepare diamino hydroxy-1,4-naphthoquinones. Also a quantum mechanics calculation on 1 have been done for studying its tautomeric equilibria and rationalizing its behaviour in the reaction with amines. (Author) 32 refs.

  16. 含芳胺及二肽的铜(Ⅱ)配合物的结构及其应用%Structures and Application of Copper(Ⅱ) Complexes Containing Aromatic Amines and Dipeptides

    Institute of Scientific and Technical Information of China (English)

    傅夏兵; 林子华; 乐学义

    2013-01-01

    Broad interests are attracted by ternary copper (Ⅱ) complexes with aromatic amines and dipeptides, since the complexes with considerable DNA-cleavage, SOD and antitumor activity can be used as chemical nucleases, SOD mimics and cancer chemotherapy drugs. This paper makes a summarization about the recent research progress from domestic and overseas in copper(Ⅱ) complexes containing aromatic amine and dipeptide, which focuses chiefly on the structures and applications of this kind of complexes.%含芳胺及二肽的铜(Ⅱ)配合物具有良好的DNA切割活性、SOD活性和抗肿瘤活性,可作化学核酸酶、SOD模拟物及肿瘤化疗药物等应用,因而引起了国内外学者的广泛关注.本文就国内外对含芳胺及二肽的铜(Ⅱ)配合物研究的进展,尤其是该类配合物的结构及其应用作一综述.

  17. A metalloenzyme-like catalytic system for the chemoselective oxidative cross-coupling of primary amines to imines under ambient conditions.

    Science.gov (United States)

    Largeron, Martine; Fleury, Maurice-Bernard

    2015-02-23

    The direct oxidative cross-coupling of primary amines is a challenging transformation as homocoupling is usually preferred. We report herein the chemoselective preparation of cross-coupled imines through the synergistic combination of low loadings of Cu(II) metal-catalyst and o-iminoquinone organocatalyst under ambient conditions. This homogeneous cooperative catalytic system has been inspired by the reaction of copper amine oxidases, a family of metalloenzymes with quinone organic cofactors that mediate the selective oxidation of primary amines to aldehydes. After optimization, the desired cross-coupled imines are obtained in high yields with broad substrate scope through a transamination process that leads to the homocoupled imine intermediate, followed by dynamic transimination. The ability to carry out the reactions at room temperature and with ambient air, rather than molecular oxygen as the oxidant, and equimolar amounts of each coupling partner is particularly attractive from an environmentally viewpoint. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Conjugated Microporous Poly(Benzochalcogenadiazole)s for Photocatalytic Oxidative Coupling of Amines under Visible Light.

    Science.gov (United States)

    Wang, Zi Jun; Garth, Kim; Ghasimi, Saman; Landfester, Katharina; Zhang, Kai A I

    2015-10-26

    Metal-free visible-light photocatalysts offer a clean, sustainable solution to many pressing environmental issues. Herein, we present a molecular design strategy to fine-tune the valence and conduction band levels of a series of conjugated microporous polymer networks based on poly(benzochalcogenadiazole) for heterogeneous photocatalysis. Enhanced photocatalytic efficiency was observed by altering the chalcogene moieties in the electron-accepting benzochalcogenadiazole unit of the polymer backbone structure. Photooxidative coupling of benzylamines was chosen as a model reaction. This design strategy leading to enhanced efficiency could potentially improve a wide range of photoredox reactions.

  19. The coupling of ω-transaminase and Oppenauer oxidation reactions via intra-membrane multicomponent diffusion – A process model for the synthesis of chiral amines

    DEFF Research Database (Denmark)

    Esparza-Isunza, T.; González-Brambila, M.; Gani, Rafiqul

    2015-01-01

    In this study we consider the theoretical coupling of an otherwise thermodynamically limited ω-transaminase reaction to an Oppenauer oxidation, in order to shift the equilibria of both reactions, with the aim of achieving a significant (and important) increase in the yield of the desired chiral a...... a significant increase in the yield of the chiral amine product may be obtained. Finally, the role of the different parameters involved in the process model has been analyzed....

  20. CuI-nanoparticles-catalyzed one-pot synthesis of benzo[b]furans via three-component coupling of aldehydes, amines and alkyne

    Directory of Open Access Journals (Sweden)

    Javad Safaei-Ghomi

    2016-09-01

    Full Text Available A novel application of copper iodide nanoparticles as an efficient catalyst has been developed for the synthesis of 2,3-disubstituted benzo[b]furan derivatives via three-component coupling of aldehydes, secondary amines and alkyne. The method presented is green, effective, inexpensive and satisfactory to give the products in high yields and short reaction times by the use of novel nanoscale materials.

  1. [Characterization of aromatic hydrocarbons in heavy gas oil using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry].

    Science.gov (United States)

    Guo, Kun; Zhou, Jian; Liu, Zelong

    2012-02-01

    An analytical method for separating and identifying the aromatic hydrocarbons in heavy gas oil using comprehensive two-dimensional gas chromatography (GC x GC) coupled to time-of-flight mass spectrometry (TOF MS) was established. The two-dimensional distribution by ring number of the aromatic hydrocarbons was obtained. Besides phenanthrene and methyl-phenanthrene, many other polycyclic aromatic hydrocarbons (PAHs) such as pyrene and benzo [a] anthracene were identified by using the retention times, standard mass spectra or literature reports. The method was successfully applied to the hydrotreating process of heavy gas oil and the hydrotreated products of phenanthrene, pyrene were identified. This method provided technical support for the characterization of aromatic hydrocarbons in heavy gas oil and the investigation of hydrogenation mechanism of polycyclic aromatic hydrocarbons. Compared with the conventional method, gas chromatography coupled to mass spectrometry (GC-MS), the GC x GC-TOF MS method illustrated the obvious advantages for heavy gas oil analysis.

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

    OpenAIRE

    Yue ePei; Aman eAsif-Malik; Canales, Juan J.

    2016-01-01

    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 neurophysiolog...

  3. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; Kranen HJ van; Veen MP van; Janus J; LBM

    2000-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals using tattoo bands, folders of paper, toys, bed clothes, watch straps and ink which are coloured with azo dyes. In these products benzidine and the benzidine related amines o-anisidine, 2,4-toluenediamine, 4,4'-diamin

  4. Cancer risk assessment of azo dyes and aromatic amines from tattoo bands, folders of paper, toys, bed clothes, watch straps and ink

    NARCIS (Netherlands)

    Zeilmaker MJ; Kranen HJ van; Veen MP van; Janus J; LBM

    2000-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals using tattoo bands, folders of paper, toys, bed clothes, watch straps and ink which are coloured with azo dyes. In these products benzidine and the benzidine related amines o-anisidine, 2,4-toluenediamine,

  5. 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.

  6. 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 (isocyanoimino)triphenylphosphorane, dibenzylamine, an aromatic carboxylic acid and cyclobutanone

    OpenAIRE

    Shajari Nahid; Kazemizadeh Reza Ali; Ramazani Ali

    2012-01-01

    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.

  7. Hepatocarcinogenic heterocyclic aromatic amines that induce cytochrome P-448 isozymes, mainly cytochrome P-448H (P-450IA2), responsible for mutagenic activation of the carcinogens in rat liver.

    Science.gov (United States)

    Degawa, M; Tanimura, S; Agatsuma, T; Hashimoto, Y

    1989-06-01

    Male F344 rats were treated with hepatocarcinogenic heterocyclic aromatic amines such as amino acid- and protein-pyrolysate components (Trp P-1, Trp P-2, Glu P-1, Glu P-2, A alpha C, MeA alpha C, IQ and MeIQx) and changes in microsomal cytochrome P-450 isozymes in the livers were examined by means of immuno-Western blotting using anti-rat cytochrome P-450 monoclonal antibodies. The results suggested that all chemicals tested induce cytochrome P-448 isozymes, particularly cytochrome P-448H (P-450IA2), which efficiently mediate mutagenic activation of the carcinogens. This was substantiated by the enzymatic analyses with the substrates showing different characters to rat cytochrome P-450 isozyme-mediated mutagenesis.

  8. Research Progresses in Sample Preparation Techniques for Determination of Aromatic Amines%芳香胺测定中试样制备技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨敏; 耿平兰; 彭黔荣; 寻思颖; 冯永渝

    2011-01-01

    介绍了目前应用在环境芳香胺测定中的固相微萃取(SPME)、柱内固相微萃取(INSPME)、搅动棒吸附萃取(SBSE)、液相微萃取(LPME)、离子液体分散液液微萃取(IL - DLLME)等试样的提取、富集、浓缩技术.%Several extraction, enrichment, and concentration techniques for sample preparation, which are recently applied in determination of aromatic amines in environment, are introduced, such as: solid-phase micro-extraction ( SPME) , in-tube solid-phase micro-extraction (INSPME), stirring-bar sorption extraction ( SBSE), liquid-phase micro-extraction (LPME) and ionic liquid dispersion liquid-liquid micro-extraction (IL-DLLME).

  9. Analysis of heterocyclic amines in hair by on-line in-tube solid-phase microextraction coupled with liquid chromatography−tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, Hiroyuki, E-mail: hkataoka@shujitsu.ac.jp; Inoue, Tsutomu; Saito, Keita; Kato, Hisato; Masuda, Kazufumi

    2013-07-05

    Graphical abstract: Mutagenic and carcinogenic heterocyclic amines are accumulated in the hair of smoker. -- Highlights: •On-line in-tube solid-phase microextraction of heterocyclic amines was optimized. •Fourteen heterocyclic amines were simultaneously determined by LC–MS/MS. •Pico gram levels of heterocyclic amines could be easily analyzed within 15 min. •Heterocyclic amines could be quantitatively analyzed from several milligrams of hair. •The method is useful for the assessment of long-term exposure to heterocyclic amines. -- Abstract: Mutagenic and carcinogenic heterocyclic amines (HCAs) are formed during heating of various proteinaceous foods, but human exposure to HCAs has not yet been elucidated in detail. To assess long-term exposure to HCAs, we developed a simple and sensitive method for measuring HCAs in hair by automated on-line in-tube solid-phase microextraction (SPME) coupled with liquid chromatography–tandem mass spectrometry (LC–MS/MS). Using a Zorbax Eclipse XDB-C8 column, 16 HCAs were analyzed within 15 min. The optimum in-tube SPME conditions were 20 draw/eject cycles of 40 μL sample at a flow rate of 200 μL min{sup −1} using a Supel-Q PLOT capillary column as an extraction device. The extracted HCAs were easily desorbed from the column by passage of the mobile phase, with no carryover observed. This in-tube SPME LC–MS/MS method showed good linearity for HCAs in the range of 10–2000 pg mL{sup −1}, with correlation coefficients above 0.9989 (n = 18), using stable isotope-labeled HCA internal standards. The detection limits (S/N = 3) of 14 HCAs except for MeAαC and Glu-P-1 were 0.10–0.79 pg mL{sup −1}. This method was successfully utilized to analyze 14 HCAs in hair samples without any interference peaks, with quantitative limits (S/N = 10) of about 0.17–1.32 pg mg{sup −1} hair. Using this method, we evaluated the exposure to HCAs in cigarette smoke and the suitability of using hair HCAs as exposure biomarkers.

  10. Environmentally benign synthesis of amides and ureas via catalytic dehydrogenation coupling of volatile alcohols and amines in a Pd-Ag membrane reactor

    KAUST Repository

    Chen, Tao

    2016-05-31

    In this study, we report the direct synthesis of amides and ureas via the catalytic dehydrogenation of volatile alcohols and amines using the Milstein catalyst in a Pd-Ag/ceramic membrane reactor. A series of amides and ureas, which could not be synthesized in an open system by catalytic dehydrogenation coupling, were obtained in moderate to high yields via catalytic dehydrogenation of volatile alcohols and amines. This process could be monitored by the hydrogen produced. Compared to the traditional method of condensation, this catalytic system avoids the stoichiometric pre-activation or in situ activation of reagents, and is a much cleaner process with high atom economy. This methodology, only possible by employing the Pd-Ag/ceramic membrane reactor, not only provides a new environmentally benign synthetic approach of amides and ureas, but is also a potential method for hydrogen storage.

  11. Research progress in detection methods and control measures for heterocyclic aromatic amines in processed meat products%加工肉制品中杂环胺的检测方法及抑制措施的研究进展

    Institute of Scientific and Technical Information of China (English)

    秦川; 郑宗平; 曾茂茂; 何志勇; 陈洁

    2013-01-01

    Heterocyclic aromatic amines are mutagenic and carcinogenic compounds that are formed naturally during cooking of proteinaceous foods such as meat. There are about 30 kinds of heterocyclic aromatic amines have been found at present.Five kinds of heterocyclic aromatic amines have been listed as potential carcinogens in the eleventh US National Toxicology Program Report on carcinogens,while three kinds of heterocyclic aromatic amines have also been affirmed as potential carcinogens by the International Agency for Research on Cancer (lARC).Meat pretreatment and detection methods for heterocyclic aromatic amines were introduced,while control measures were summarized.%杂环胺是肉类等高蛋白食品在烹调过程中产生一类具有致癌、致突变作用的化合物.目前已经从高温肉制品中发现近三十种的杂环胺 . 美国国家毒理学计划在第十一届癌症报告中将五种杂环胺列入潜在的人类致癌物质,且国际癌症研究中心也将三种杂环胺列入潜在的人类致癌物质.鉴于杂环胺可能对人类的健康带来极大危害,本文结合过去多年的文献研究,介绍了杂环胺的提取及检测方法,并对肉制品中杂环胺的抑制措施进行了概述,以期为将来研究提供科学参考.

  12. Pilot-scale study on nitrogen and aromatic compounds removal in printing and dyeing wastewater by reinforced hydrolysis-denitrification coupling process and its microbial community analysis.

    Science.gov (United States)

    Li, Chao; Ren, Hongqiang; Yin, Erqin; Tang, Siyuan; Li, Yi; Cao, Jiashun

    2015-06-01

    Aiming to efficiently dispose printing and dyeing wastewater with "high organic nitrogen and aromatic compounds, but low carbon source quality", the reinforced anaerobic hydrolysis-denitrification coupling process, based on improved UASB reactors and segregated collection-disposition strategy, was designed and applied at the pilot scale. Results showed that the coupling process displayed efficient removal for these two kinds of pollutants (nitrogen and aromatics), since the concentration of NH3-N (shortened as ρ (NH3-N)) aromatics reduced greatly by UASBs according to GC-MS. Microbial community analysis by PCR-DGGE showed that Bacteroidetes and Alphaproteobacteria were the dominant communities in the bioreactors and some kinds of VFAs-producing, denitrifying and aromatic ring opening microorganisms were discovered. Further, the nirK and bcrA genes quantification also indicated the coupling process owned outstanding denitrification and aromatic compound-degrading potential, which demonstrates that the coupling process owns admirable applicability for this kind of wastewater treatment.

  13. 离子液体掺杂聚苯胺固相微萃取涂层的电沉积制备及其在芳香胺检测中的应用%Electrochemical Preparation of Polyaniline-Ionic Liquid Based Solid Phase Microextraction Coating and Its Application in Determination of Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    王妹丽; 王娟; 赵发琼; 曾百肇

    2011-01-01

    新型萃取材料及相关涂层制备技术是固相微萃取技术发展的重点.本研究在1-羟丙基-3-甲基咪唑-四氟硼酸盐([C3(OH)mim][BF4])和HNO3混合溶液中,通过电化学方法在铂(Pt)丝表面固定新型聚苯胺-离子液体(PANI-IL)涂层.电镜分析表明,离子液体存在时,PANI膜孔结构变均匀、比表面积增大.以芳香胺为模拟物,考察萃取头的顶空固相微萃取(HS SPME)性能.在优化条件下,5种芳香胺的检出限为0.04~0.12μg/L(SIN=3);线性范围为0.15~1000 μg/L.同一萃取头萃取5次的相对标准偏差(RSD)小于4.6%;不同萃取头的RSD则在2.4%~9.5%(n=3)之间.与自制聚苯胺(PANI/Pt)及商品化的聚丙烯酸酯(PA)萃取头相比,PANI-IL/Pt萃取头具有更高的萃取率.此外,PANI-IL涂层对苯类化合物亦有较高的萃取能力.萃取头使用120余次后,萃取性能无明显变化,表明萃取头的稳定性好、使用寿命长.%A novel solid phase microextraction coating of polyaniline-ionic liquid (PANI-IL) was prepared by electrodeposition on a Pt wire in aqueous solutions containing ionic liquid [C3 (OH) mim][BF4] and nitric acid. The resulted coating was more uniform and porous than PANI coating. Taking five aromatic amines as models, the performance of the PANI-IL/Pt fiber was explored. Under the optimized conditions, when they were determined by GC after headspace SPME with the PANI-IL/Pt, the detection limits were 0. 04 - 0. 12 μg/L (S/N = 3) and the linear ranges were 0. 15 -1000 μg/L. These aromatic amines were determined for five times using a PANI-IL/Pt fiber coupled with GC and the RSD of chromatographic peak areas were smaller than 4.6% ; the fiber to fiber RSD was 2. 4-9. 5% for different aromatic amines. In comparison with PANI/Pt and commercial PA, the PANI-IL/Pt fiber showed higher extraction efficiency and repeatability. It also exhibited high extraction capability to benzene compounds. The PANI-IL/Pt fiber was used for more than 120

  14. Scientific Opinion on Flavouring Group Evaluation 94, Revision 2 (FGE.94Rev2: Consideration of aliphatic amines and amides evaluated in an addendum to the group of aliphatic and aromatic amines and amides evaluated by the JECFA (68th meeting

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-04-01

    Full Text Available The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA, and to decide whether further evaluation is necessary, as laid down in Commission Regulation (EC No 1565/2000. The present consideration concerns a group of 12 aliphatic amines and amides evaluated by the JECFA at the 68th meeting in 2007. This revision is required owing to additional toxicity data on 3-(3,4-dimethoxyphenyl-N-[2-(3,4-dimethoxyphenyl-ethyl]-acrylamide [FL-no: 16.090]. The substances were evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern and available data on metabolism and toxicity. The Panel agrees with JECFA conclusion “No safety concern at estimated levels of intake as flavouring substances” based on the MSDI approach for all substances considered in this FGE. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have been considered and for all 12 substances, the information is adequate.

  15. Vortex-assisted liquid-liquid microextraction coupled with derivatization for the fluorometric determination of aliphatic amines.

    Science.gov (United States)

    Chang, Wei-Yao; Wang, Chin-Yi; Jan, Jeng-Lyan; Lo, Yu-Shiu; Wu, Chien-Hou

    2012-07-27

    A new one-step derivatization and microextraction technique was developed for the fluorometric determination of C(1)-C(8) linear aliphatic primary amines in complex sample solutions containing high levels of amino acids. In this method, amines were derivatized with o-phthalaldehyde (OPA) and 2-mercaptoethanol (2-ME) in aqueous solution and extracted simultaneously by vortex-assisted liquid-liquid microextraction (VALLME). Parameters affecting the extraction efficiency were investigated in detail. The optimum conditions were as follows: 50 μL of isooctane as the extractant phase; 2.0 mL aqueous donor samples with 12 mM OPA, 24 mM 2-ME, and 0.1 M borate buffer at pH 10; 1 min vortex extraction time; centrifugation for 4 min at 6000 rpm. After centrifugation, the enriched analytes in the floated extractant phase were determined by HPLC-FL in less than 14 min. Under the optimum conditions, the limits of detection were of the order of 0.09-0.31 nM. The calibration curves showed good linearity over the investigated concentration range between 0.4 and 40 nM. The proposed method has been applied to the determination of aliphatic amines in acidophilus milk, beer, and Cu(II)/amino acid solution.

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

    Science.gov (United States)

    Pei, Yue; Asif-Malik, Aman; Canales, Juan J

    2016-01-01

    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 behavioral 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 signaling 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

  17. 非等温DSC研究低共熔点芳胺/环氧E44固化动力学%Curing Kinetics of an Eutectic Aromatic Amine/Epoxy Resin E44 by Nonisothermal DSC Method

    Institute of Scientific and Technical Information of China (English)

    谢建军; 王爱民; 曼亚珂; 潘勤敏

    2012-01-01

    The curing reaction kinetics of an eutectic aromatic amine/epoxy resin E44 system is investigated by nonisothermal DSC method. The kinetic parameters of this system are calculated by Kissinger, Ozawa and Crane e-quations; the apparent activation energy E= 49.2 kJ/mol(by Kissinger and Ozawa methods) , the reaction order n = 0. 95(by Crane equation) , the frequent factor A-2. 60×l05 s-1(by Kissinger method). The kinetic model of the curing process based on n order reaction equation is established, which is used for modeling the curing reaction characteristics. The curing conditions are defined as follow; 50t/2 h, 140t/2 h, post-curing 200℃/2 h. The curing behavior of the system is hardly affected by the change in the amount of the filler boron carbide ( B4 C ) added into the eutectic aromatic amine/epoxy resin E44 system.%采用非等温DSC法对低共熔点芳胺固化剂/环氧E44体系进行了固化动力学研究,通过Kissinger、Ozawa和Crane方法获得了该体系固化动力学参数:表观活化能E=49.2 kJ/mol,固化反应级数n=0.95,频率因子A=2.60×105s-1.固化动力学方程可表示为:((dα)/(dt))=2.60×105(1-α)0.95exp(-(49200/RT)).初步确定了该体系固化工艺条件为50℃/2 h、140℃/2 h、200℃后处理2h.填料B4C加入量对该体系固化过程的DSC曲线几乎无影响.

  18. APPLICATION OF HOLLOW FIBER MEMBRANE/LIQUID-PHASE MICROEXTRACTION FOR THE DETERMINATION OF AROMATIC AMINES GENERATED FROM AZO DYES%纤维膜三相液相微萃取在测定偶氮染料降解产生芳香胺中的应用

    Institute of Scientific and Technical Information of China (English)

    李海燕; 代喜斌

    2011-01-01

    采用纤维膜保护的三相液相微萃取(HF-LLLME)技术,对偶氮染料在人工汗液和光辐照协同作用下降解产生致癌芳香胺的分析方法进行了研究.选用苯胺、邻甲苯胺、对氯苯胺和对硝基苯胺的汗液混合溶液进行模拟样品预处理,以正辛醇为有机萃取相,在供体相pH值为9,NaC l浓度为200.gL-1,接收相为pH=1的盐酸水溶液,萃取时间为60 m in的萃取条件下,4种芳香胺的富集倍数在410—1250倍之间.将接收相直接进行毛细管电泳(CE)测定,样品相中4种芳香胺质量浓度在10—100μg.L-1范围内,其质量浓度与%A simple and rapid three phase(liquid-liquid-liquid) micro extraction method(LLLME) using hollow fibre membrane(HF) was employed before capillary electrophoresis(CE) analysis.For the pretreatment of aromatic amines which are generated from azo dyes in perspiration matrix by photo-catalysis,aniline,o-toluidine,4-chloroaniline,4-nitroaniline as model compounds were extracted from simulative solution of perspiration.Under the optimized conditions,using octanol as organic phase,pH 9 and 200 g·L-1 ion concentration in the donor phase,pH 1 for the receiving phase and 60 min extraction time,enrichment factors ranging from 410 to 1250 were obtained for the four aromatic amines.The receiving phase was analyzed by CE directly.The absorption of aromatic amines had good linear relation with the concentration of aromatic amines in the range of 10—100 μg·L-1 at the given CE condition.The real sample,aromatic amines generated from brilliant X-3B and disperse red S-R in perspiration by photo catalysis,were also successfully detected.The recoveries of aromatic amines generated from brilliant X-3B and disperse red S-R were 90.8%—93.0% and 97.8%—115.0% separately.This HF-LLLME method demostrates good separation and enrichment of aromatic amines in perspiration matrix,HF-LLLME in conjunction with CE can quantitatively determine of aromatic

  19. 煎炸对肉制品中杂环胺及多环芳香烃化合物含量的影响及其控制措施%Effect Factors of Formation of Polycyclic Aromatic Hydrocarbon and Heterocyclic Amines in Fried Meat and Control Measures

    Institute of Scientific and Technical Information of China (English)

    孟晓霞; 彭增起; 冯云

    2009-01-01

    Fried meat is one common food.However,in the frying process,strong carcinogen will be produced such as polycyclic aromatic hydrocarbons,heterocyclic amines and harm to human health. This article studied the formation conditions of polycyclic aromatic hydrocarbon and heterocyclic amines in fried meat.and list the conffol measures.%煎炸是最常用的烹调方法之一.肉类食品在煎炸过程中能产生杂环胺,多环芳香烃等强致癌物,对人体健康存在极大的危害.本文就影响煎炸肉制品中杂环胺及多环芳香烃化合物形成的因素进行了分析,并提出具体的控制措施.

  20. Computer-aided discovery of aromatic L-α-amino acids as agonists of the orphan G protein-coupled receptor GPR139

    DEFF Research Database (Denmark)

    Ísberg, Vignir; Andersen, Kirsten Bayer; Bisig, Christoph

    2014-01-01

    GPR139 is an orphan G protein-coupled receptor expressed mainly in the central nervous system. We developed a pharmacophore model based on known GPR139 surrogate agonists which led us to propose aromatic-containing dipeptides as potential ligands. Upon testing, the dipeptides demonstrated agonism...

  1. Synthesis of 2-azaanthracenes via a sequential Sonogashira coupling/alkynyl imine-allenyl imine isomerization/aza-Diels-Alder/elimination-aromatization reaction.

    Science.gov (United States)

    Cao, Jian; Yang, Xiongfa; Hua, Xilin; Deng, Yuan; Lai, Guoqiao

    2011-02-04

    An interesting sequential Sonogashira coupling/alkynyl imine-allenyl imine isomerization/aza-Diels-Alder/elimination-aromatization reaction, providing a facile synthesis of substituted 2-azaanthracenes from 1,6-diynes and imidoyl chlorides, is reported. The easy procedure accessing the products efficiently from readily available starting materials may imply a potential synthetic application.

  2. Evaluation and application of microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for the determination of polar heterocyclic aromatic amines in hamburger patties.

    Science.gov (United States)

    Aeenehvand, Saeed; Toudehrousta, Zahra; Kamankesh, Marzieh; Mashayekh, Morteza; Tavakoli, Hamid Reza; Mohammadi, Abdorreza

    2016-01-01

    This study developed an analytical method based on microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for the determination of three polar heterocyclic aromatic amines from hamburger patties. Effective parameters controlling the performance of the microextraction process, such as the type and volume of extraction and disperser solvents, microwave time, nature of alkaline aqueous solution, pH and salt amount, were optimized. The calibration graphs were linear in the range of 1-200 ng g(-1), with a coefficient of determination (R(2)) better than 0.9993. The relative standard deviations (RSD) for seven analyses were between 3.2% and 6.5%. The recoveries of those compounds in hamburger patties were from 90% to 105%. Detection limits were between 0.06 and 0.21 ng g(-1). A comparison of the proposed method with the existing literature demonstrates that it is a simple, rapid, highly selective and sensitive, and it gives good enrichment factors and detection limits for determining HAAs in real hamburger patties samples.

  3. 新型芳基取代5,6-去甲斑蝥酰亚胺衍生物的质谱研究%Mass Spectra of Novel 5,6-Dehydronorcantharidin Derivatives Substituted by Aromatic Amine

    Institute of Scientific and Technical Information of China (English)

    邓莉平; 齐陈泽; 吕建国; 陶伟峰; 王玮

    2009-01-01

    The mass spectra of a series of novel 5,6-dehydronorcantharidin derivatives substituted by aromatic amine have been examined.The paper is to report the preliminary results of an investigation of the mass spectrometric behavior of heterocyclic compounds formed by 1,3-dipolar cycloaddition reaction of nitrile oxides and N-substituted cantharidinimides which is formed by Diels-Alder reaction to show that such compounds upon electron impact may fragment by way of a cyclo-elimination reaction corresponding,formally,to the reverse process of their formation.%旨在研究一系列5,6-去甲斑蝥酰亚胺衍生物的质谱裂解特征.研究结果显示异口恶唑并N-取代去甲去氢斑蝥酰亚胺衍生物,即各种1,3-偶极子氧化腈"现场"与N-取代斑蝥酰亚胺进行[3+2]环加成的系列产物在电子轰击下,质谱裂解的各种碎片呈现了此系列杂环分子结构环消除的规律性-逆1,3-偶极环加成反应的历程.

  4. Chemical characterization of aromatic compounds in extra heavy gas oil by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

    Science.gov (United States)

    Avila, Bárbara M F; Pereira, Ricardo; Gomes, Alexandre O; Azevedo, Débora A

    2011-05-27

    Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was used for the characterization of aromatic compounds present in extra heavy gas oil (EHGO) from Brazil. Individual identification of EHGO compounds was successfully achieved in addition to group-type separation on the chromatographic plane. Many aromatic hydrocarbons, especially polycyclic aromatic hydrocarbons and sulfur compounds, were detected and identified, such as chrysenes, phenanthrenes, perylenes, benzonaphthothiophenes and alkylbenzonaphthothiophenes. In addition, triaromatic steroids, methyl-triaromatic steroids, tetrahydrochrysenes and tetraromatic pentacyclic compounds were present in the EHGO aromatic fractions. Considering the roof-tile effect observed for many of these compound classes and the high number of individual compounds identified, GC×GC-TOFMS is an excellent technique to characterize the molecular composition of the aromatic fraction from EHGO samples. Moreover, data processing allowed the quantification of aromatic compounds, in class and individually, using external standards. EHGO data were obtained in μgg(-1), e.g., benzo[a]pyrene were in the range 351 to 1164μgg(-1). Thus, GC×GC-TOFMS was successfully applied in EHGO quantitative analysis.

  5. Cathodic Aromatic C,C Cross-Coupling Reaction via Single Electron Transfer Pathway.

    Science.gov (United States)

    Qu, Yang; Tateno, Hiroyuki; Matsumura, Yoshimasa; Kashiwagi, Tsuneo; Atobe, Mahito

    2017-03-07

    We have successfully developed a novel cathodic cross-coupling reaction of aryl halides with arenes. Utilization of the cathodic single electron transfer (SET) mechanism for activation of aryl halides enables the cross-coupling reaction to proceed without the need for any transition metal catalysts or single electron donors in a mild condition. The SET from a cathode to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle also consists entirely of anion radical intermediates.

  6. Cathodic Aromatic C,C Cross-Coupling Reaction via Single Electron Transfer Pathway

    Directory of Open Access Journals (Sweden)

    Yang Qu

    2017-03-01

    Full Text Available We have successfully developed a novel cathodic cross-coupling reaction of aryl halides with arenes. Utilization of the cathodic single electron transfer (SET mechanism for activation of aryl halides enables the cross-coupling reaction to proceed without the need for any transition metal catalysts or single electron donors in a mild condition. The SET from a cathode to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle also consists entirely of anion radical intermediates.

  7. A study of diazonium couplings with aromatic nucleophiles both in solution and on a polymer surface

    Science.gov (United States)

    Chng, Shuyun; Parker, Emily M.; Griffiths, Jon-Paul; Moloney, Mark G.; Wu, Linda Y. L.

    2017-04-01

    Diazonium coupling is a technique finding wider application to materials and biological science, for hybridization and linking processes, and for the construction of responsive surface functionality. For this reason, detailed examination of solution and surface processes was warranted, and results of such a study are reported here. The modification of polystyrene surfaces was examined as a model, and the process compared to a solution mimic using N,N-dimethylaniline. It was confirmed that solution and solid surface reactions proceed in a similar manner in terms of the chemical functionality generated, but with lower chemical efficiency and reaction times slower for the latter, in a reaction which was pH dependent. The solution process was shown to give only the trans-azo para- coupled products. Whilst there are clear similarities between the solution and surface chemistry, the efficiency of coupling at a surface is not necessarily replicated in the chemical yield of the mimicking solution processes, but nonetheless provides an alternative to other Click-type surface modifications. It should not be assumed that such couplings occur with quantitative efficiency at the surface.

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

    Science.gov (United States)

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

    2011-11-15

    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.

  9. High performance of a cobalt–nitrogen complex for the reduction and reductive coupling of nitro compounds into amines and their derivatives

    Science.gov (United States)

    Zhou, Peng; Jiang, Liang; Wang, Fan; Deng, Kejian; Lv, Kangle; Zhang, Zehui

    2017-01-01

    Replacement of precious noble metal catalysts with low-cost, non-noble heterogeneous catalysts for chemoselective reduction and reductive coupling of nitro compounds holds tremendous promise for the clean synthesis of nitrogen-containing chemicals. We report a robust cobalt–nitrogen/carbon (Co–Nx/C-800-AT) catalyst for the reduction and reductive coupling of nitro compounds into amines and their derivates. The Co–Nx/C-800-AT catalyst was prepared by the pyrolysis of cobalt phthalocyanine–silica colloid composites and the subsequent removal of silica template and cobalt nanoparticles. The Co–Nx/C-800-AT catalyst showed extremely high activity, chemoselectivity, and stability toward the reduction of nitro compounds with H2, affording full conversion and >97% selectivity in water after 1.5 hours at 110°C and under a H2 pressure of 3.5 bar for all cases. The hydrogenation of nitrobenzene over the Co–Nx/C-800-AT catalyst can even be smoothly performed under very mild conditions (40°C and a H2 pressure of 1 bar) with an aniline yield of 98.7%. Moreover, the Co–Nx/C-800-AT catalyst has high activity toward the transfer hydrogenation of nitrobenzene into aniline and the reductive coupling of nitrobenzene into other derivates with high yields. These processes were carried out in an environmentally friendly manner without base and ligands. PMID:28232954

  10. Metabolic activation of N-hydroxy arylamines, N-hydroxy heterocyclic amines and ring-hydroxymethyl polycyclic aromatic hydrocarbons by human sulfotransferases

    Energy Technology Data Exchange (ETDEWEB)

    Chou, H.C.

    1993-01-01

    Arylamines and polycyclic aromatic hydrocarbons (PAHs) are two major classes of chemical carcinogens. N-Hydroxylation of arylamines is regarded to be a necessary process for their mutagenicity and carcinogenicity, while alkyl-hydroxylation is the major metabolic pathway for alkyl-substituted PAHs. Evidence has been presented that sulfation of several N-hydroxy arylamines and hydroxymethyl PAHs is an important pathway leading to the formation of ultimate carcinogens in experiment animals. Sulfation of these chemicals forms putative sulfuric acid ester intermediates that can rearrange to electrophilic nitrenium or carbenium ions capable of forming covalent adducts with important cellular macromolecules. In order to study the metabolic activation by sulfotransferase(s) in various human tissue preparations an in vitro enzymatic assay was established. A metabolic phenotyping method was also developed for thermostable phenolsulfotransferase (TS-PST) in platelet homogenates (correlated with TS-PST activity in other tissues) based on a simple colorimetric assay using 2-naphthol as substrate. By using a PAPS-regenerating system to supply the activated sulfate and calf thymus DNA to trap the reactive metabolites, we found that N-hydroxy derivatives of the carcinogens, 4-aminobiphenyl (4-ABP), 4,4[prime]-methylene-bis(2-chloroaniline) (MOCA), 2-acetylaminofluorene (2-AAF), 2-aminofluorene (2-AF), 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), and 2-amino-6-methyldipyrido [1,2-1:3[prime],2[prime]-d]imidazole (Glu-P-1) were metabolically activated by human TS-PST. On the other hand, three methyl-hydroxylated derivatives (7-OH, 12-OH, and 7,12-diOH) of 7, 12-dimethylbenz[a]anthracene (DMBA) were metabolically activated by human steroid sulfotransferase. Human sulfotransferase(s)-mediated activation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was not observed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Koupaie, E., E-mail: ehssan.hosseini.k@gmail.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Alavi Moghaddam, M.R., E-mail: alavim@yahoo.com [Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT), Hafez Ave., Tehran 15875-4413 (Iran, Islamic Republic of); Hashemi, S.H., E-mail: h_hashemi@sbu.ac.ir [Environmental Science Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2011-11-15

    Highlights: {yields} Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. {yields} More than 65% of the dye total metabolites was completely mineralized. {yields} Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. {yields} Inhibition of biofilm growth was increased with increasing the initial dye concentration. {yields} 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.

  12. 杂环芳胺结构与致癌性和致突性的密度泛函研究%Density Functional Study of Relationship Between Structure and Carcinogenicity/Mutagenicity of Heterocyclic Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    胡辰尧; 王涛; 居学海; 曾秀琳

    2012-01-01

    根据杂环芳胺(HCAs)在生物体内的代谢特征,用DFT-B3LYP方法分别进行了19种杂环芳胺类致癌/致突化合物在气相和水溶剂下的量子化学计算,获得了其结构与致癌性和致突性的相关关系.结果表明:9种HCAs的致癌性与分子的前线轨道能量之差△Egap,neutral、最高占有轨道能量EHOMO及与氨基相连的稠环数n有较好的线性关系,相关系数r为0.969,F检验因子为25.47(大于其F**0.1临界值).对19种致突性HCAs在水溶剂化条件下的计算表明:分子偶极矩μ和Ar-NH+离子前线轨道能级差△Egap,ion及其平方与致突性密切相关,r为0.912,F为17.3(大于其F**0.01临界值).%Based on the metabolic mechanisms of the heterocyclic aromatic amines( HCAs) in the organism, the. DFT-B3LYP quantum chemistry calculations are performed on 19 HCAs with careinogenicity and mutagenicity in the gaseous state or the water solvent, and the relationships between the structures and the carcinogenicity/mutagenicity are established. Results show that the carcinogenicity for 9 HCAs is related with their frontier orbital gap △Egap neutra], the energy of highest occupied-molecular orbital EHOMO and the number of fused rings linked to the amine group re. The related coefficient r is 0.969,and the F factor is 25.47(larger than the corresponding critical value F0.01 ). The mutagenicity of 19 HACs in the water solvent is related to their molecular dipole moment μ,the frontier orbital gap of the Ar-NH+AEgep,ion and its square and the fused ring number. The r is 0. 912 and F is 17. 3(larger than F0.01 ) .

  13. Characterisation of Leather Candidate Certified Reference Materials for their Mass Fractions of Aromatic Amines%用于分析皮革样本中芳香胺质量含量的检定标准物质的表征

    Institute of Scientific and Technical Information of China (English)

    Jan-Willem Wegener; Haiko Schulz; 龚英

    2011-01-01

    Three batches of leather samples were colored with nine aso dyes that can yield eight proven or suspected carcinogenic aromatic amines under reduction conditions. The samples were milled to grains and bottled in jars. A group of five laboratories has established the mass fraction of the amines in a ring test using different analytical methods. The methods included a reduction step in order to cleave the azo dyes into the aromatic amines. Quantification was by standard addition: sub - samples of the leathers were spiked with known amounts of azo dyes of known purity. It was possible to establish the mass fractions of six of the eight aromatic amines in three of the leather samples.%用9种已经确认或被怀疑的在还原条件下将生成8种致癌芳香胺的染料,对3批皮革样品染色.将皮革样品切碎为颗粒后,装入到广口瓶中.由5个实验室组成的试验组,在环试验中采用不同方法分析这些芳香胺在皮革中所占的质量分数.这些分析方法均包括还原步骤,即,使偶氮染料裂解为芳香胺.采用向皮革子样本加入已知量的且已知纯度的偶氮染料这种标准加入法,进行定量分析.在这3批皮革样品中,可以对这8类芳香胺中的6种进行质量含量的分析.

  14. Heavy metals in aromatic spices by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Bua, Daniel Giuseppe; Annuario, Giovanni; Albergamo, Ambrogina; Cicero, Nicola; Dugo, Giacomo

    2016-09-01

    Objective of this study was to determine the content of Cd, Hg, As and Pb in common spices traded in the Italian market, using inductively coupled plasma-mass spectrometry (ICP-MS). The results were compared with the maximum limits established by the national Legislative Decree (LD) no. 107 implementing the Council Directive 88/388/EEC and by international organisations, such as Food and Agriculture Organization (FAO) and World Health Organization (WHO). Food safety for spices was assessed considering the tolerable weekly intake (TWI) and the provisional tolerable weekly intake (PTWI), respectively, for Cd and Hg and the 95% lower confidence limit of the benchmark dose of 1% extra risk (BMDL01) for As and Pb. Investigated elements in all samples were within the maximum limits as set by the national and international normative institutions. Nevertheless, the heavy metal content of some spices exceeded the PTWI, TWI and BMDL01, which needs attention when considering consumer's health.

  15. Coupling paper-based microfluidics and lab on a chip technologies for confirmatory analysis of trinitro aromatic explosives.

    Science.gov (United States)

    Pesenti, Alessandra; Taudte, Regina Verena; McCord, Bruce; Doble, Philip; Roux, Claude; Blanes, Lucas

    2014-05-20

    A new microfluidic paper-based analytical device (μPAD) in conjunction with confirmation by a lab on chip analysis was developed for detection of three trinitro aromatic explosives. Potassium hydroxide was deposited on the μPADs (0.5 μL, 1.5 M), creating a color change reaction when explosives are present, with detection limits of approximately 7.5 ± 1.0 ng for TNB, 12.5 ± 2.0 ng for TNT and 15.0 ± 2.0 ng for tetryl. For confirmatory analysis, positive μPADs were sampled using a 5 mm hole-punch, followed by extraction of explosives from the punched chad in 30 s using 20 μL borate/SDS buffer. The extractions had efficiencies of 96.5 ± 1.7%. The extracted explosives were then analyzed with the Agilent 2100 Bioanalyzer lab on a chip device with minimum detectable amounts of 3.8 ± 0.1 ng for TNB, 7.0 ± 0.9 ng for TNT, and 4.7 ± 0.2 ng for tetryl. A simulated in-field scenario demonstrated the feasibility of coupling the μPAD technique with the lab on a chip device to detect and identify 1 μg of explosives distributed on a surface of 100 cm(2).

  16. Headspace in-tube microextraction coupled with micellar electrokinetic chromatography of neutral aromatic compounds.

    Science.gov (United States)

    Cho, Sung Min; Park, Bum Su; Jung, Woo Sung; Lee, Sang Won; Jung, Yunhwan; Chung, Doo Soo

    2016-02-01

    Headspace (HS) extraction can be carried out easily and aptly via single drop microextraction coupled with capillary electrophoresis (CE). However, one drawback is the difficulty of keeping the single drop stably at the capillary tip. To solve this problem, we have recently demonstrated HS in-tube microextraction (ITME) of acidic compounds such as chlrophenols in an acidic sample using a basic run buffer plug in the separation capillary for CE as an acceptor phase. In this report, an organic acceptor plug in a capillary was used to extract neutral organic volatile pollutants such as BTEX (benzene, toluene, ethylbenzene, and m-xylene). After extraction, the analytes enriched in the organic acceptor plug were analyzed with micellar electrokinetic chromatography (MEKC). The enrichment factors for BTEX in a standard solution were up to 350 under an optimal condition of 25°C for 20 min. As an application, BTEX spiked into bottled water were analyzed with HS-ITME-MEKC, and the enrichment factors for BTEX were up to 320. The limits of detections were 1-4 ppb, which are at least 200 times lower than the US Environmental Protection Agency guidelines for drinking water, except benzene. The entire procedure of HS-ITME-MEKC was carried out automatically using a commercial CE instrument.

  17. 基于表面增强拉曼光谱的水中芳香胺类污染物现场快速检测技术%RAPID ON-SITE DETECTION OF AROMATIC AMINES IN WATER BY SURFACE-ENHANCED RAMAN SPECTROMETRY

    Institute of Scientific and Technical Information of China (English)

    渠陆陆; 李大伟; 翟文磊; 龙亿涛

    2011-01-01

    利用表面增强拉曼光谱(SERS)对水中芳香胺类污染物进行检测分析.通过化学法合成具有SERS活性的银胶,紫外可见光谱、动态光散射及扫描电子显微镜表征显示制备的银胶分散性良好、粒径均匀;选用背景散射弱、价格便宜的薄层色谱板为承载基底,利用所制备的银胶并结合便携式拉曼光谱仪对芳香胺类污染水样进行现场快速检测,结果显示,适当的胶体浓度和团聚剂浓度可提高检测效果,优化条件下的部分芳香胺检测限可达5.0×10^-6mol.L^-1.研究表明,SERS技术可用于水中芳香胺的现场快速检测,有望成为一种新的水污染应急分析%Aromatic amines water were qualitatively detected using surface-enhanced Raman spectroscopy(SERS).SERS-active silver colloids were fabricated via wet chemical synthesis and characterized by UV-Vis spectro-photometry,dynamic light scattering and scanning electron microscopy(SEM),which revealed good dispersibility and uniformity of silver colloids.Thin-layer chromatography(TLC) plates were coated with silver colloids as SERS substrates.A portable Raman spectrometer was employed for rapid on-site detection of aromatic amines in water.In addition,the results showed that appropriate concentration of silver colloids and NaCl improved SERS detection,and the detection limit of some aromatic amines was as low as 5×10^-6 mol·L^-1 under the optimum condition.This indicates SERS can be used for the rapid on-site detection of aromatic amines in water.

  18. 含叔胺结构高光响应性香豆素衍生物的设计合成%Design and Synthesis of Highly Photo-Crosslinkable Coumarin Derivatives Containing Aromatic Tertiary Amine

    Institute of Scientific and Technical Information of China (English)

    江金强; 代鹏; 宗奕吾; 刘晓亚; 张胜文; 陈明清

    2009-01-01

    以环氧氯丙烷为桥接,将具有较强给电子能力的芳叔胺(ATA)结构引入香豆素衍生物C分子中,通过芳叔胺结构的光化学促进作用加速香豆素基元的光二聚反应.用紫外(UV)和荧光(FL)光谱等手段对该香豆素衍生物进行表征.结果表明,芳叔胺结构的引入可有效增强香豆素基元在260-400 nm之间的吸收.紫外点光源光二聚反应实验表明,芳叔胺结构的引入使香豆素基元的光响应性能得以大幅增强,在相同光照条件下,其在匀速反应区间内对光照时间的依赖性的斜率高达6.47,光二聚反应程度达到80%时所需光照时间仅为29 s.%Using epichlorohydrin as bridged unit, the aromatic tertiary amine (ATA) was introduced to prepare the highly photo-crosslinkable coumarin compound C and to accelerate the photo-dimerization of coumarin unit. Ultraviolet (UV) and fluorescence (FL) spectra were used to evaluate the coumarin C. It was found that the introduced ATA could enhance the absorption between 260-400 nm. The spot UV irradiation experiments showed that, after being bridged with ATA, the coumarin C would gain a highly photo-dimerization with a high slope of 6.47 in the uniform photo-reaction, and a short time of 29 s to gain 80% photo-dimerization.

  19. Biomarkers of food-borne carcinogen heterocyclic aromatic amines%食品致癌物杂环胺的生物标记物的研究进展

    Institute of Scientific and Technical Information of China (English)

    彭利娟

    2016-01-01

    高温烹调加工肉类食品过程中所产生的杂环胺( HAAs)是一类具有致突变,致癌作用的物质。相关流行病研究显示,长期摄入高温烹调的、富含HAAs的肉类食物,提升了前列腺癌、乳腺癌、肠癌的患病风险。但现有研究成果尚不能对HAAs的摄入与相关癌症风险的关系进行有效评估。寻找长效、稳定的生物标记物并建立高选择性、高灵敏度的检测方法是该项研究的关键所在。本综述着重讨论了可能应用于分子流行病学研究中HAAs的生物标记物,包括HAAs、HAA的代谢物、DNA加合物和蛋白质加合物。同时也对用于HAAs生物监控的分析方法进行了讨论。%Heterocyclic aromatic amines ( HAAs ) are carcinogens and mutagens that are formed during the high-temperature cooking of meats .A number of studies have reported a positive association between well-done meat consumption and cancer risks of the human prostate , mammary and colon .However , the association of HAAs formed in cooked meat and cancer risks has been difficult to establish .There is a critical need to establish stable , long-term biomarkers of HAAs , and develop corresponding methods with high selectivity and sensitivity .In this re-view, we highlight the biomarkers of HAAs that may be implemented in molecular epidemiology studies , including HAAs, their metabolites , DNA adducts and protein adducts .The advanced analytical approaches that have been successfully developed to biomonitor biological effects of these chemicals are also discussed .

  20. Palladium Nanoparticles Tethered in Amine-Functionalized Hypercrosslinked Organic Tubes as an Efficient Catalyst for Suzuki Coupling in Water

    Directory of Open Access Journals (Sweden)

    Arindam Modak

    2016-10-01

    Full Text Available It is highly desirable to design functionalized supports in heterogeneous catalysis regarding the stabilization of active sites. Pd immobilization in porous polymers and henceforth its application is a rapidly growing field. In virtue of its’ scalable synthesis and high stability in reaction conditions, amorphous polymers are considered an excellent scaffold for metal mediated catalysis, but the majority of them are found as either agglomerated particles or composed of rough spheres. Owing to several important applications of hollow organic tubes in diverse research areas, we aimed to utilize them as support for the immobilization of Pd nanoparticles. Pd immobilization in nanoporous polymer tubes shows high activity in Suzuki cross coupling reactions between aryl halides and sodium phenyl trihydroxyborate in water, which deserves environmental merit.

  1. Determination of oxygen and nitrogen derivatives of polycyclic aromatic hydrocarbons in fractions of asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

    2015-12-01

    Liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization was used for the determination of polycyclic aromatic hydrocarbon derivatives, the oxygenated polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons, formed in asphalt fractions. Two different methods have been developed for the determination of five oxygenated and seven nitrated polycyclic aromatic hydrocarbons that are characterized by having two or more condensed aromatic rings and present mutagenic and carcinogenic properties. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all compounds. The detection limits of the methods ranged from 0.1 to 57.3 μg/L for nitrated and from 0.1 to 6.6 μg/L for oxygenated derivatives. The limits of quantification were in the range of 4.6-191 μg/L for nitrated and 0.3-8.9 μg/L for oxygenated derivatives. The methods were validated against a diesel particulate extract standard reference material (National Institute of Standards and Technology SRM 1975), and the obtained concentrations (two nitrated derivatives) agreed with the certified values. The methods were applied in the analysis of asphalt samples after their fractionation into asphaltenes and maltenes, according to American Society for Testing and Material D4124, where the maltenic fraction was further separated into its basic, acidic, and neutral parts following the method of Green. Only two nitrated derivatives were found in the asphalt sample, quinoline and 2-nitrofluorene, with concentrations of 9.26 and 2146 mg/kg, respectively, whereas no oxygenated derivatives were detected.

  2. High performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry for sensitive determination of bioactive amines in donkey milk.

    Science.gov (United States)

    La Torre, Giovanna Loredana; Saitta, Marcello; Giorgia Potortì, Angela; Di Bella, Giuseppa; Dugo, Giacomo

    2010-08-06

    In the present study we report on the optimization and validation of a sensitive high performance liquid chromatography atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) method for the determination of 8 bioactive amines (histamine, tyramine, tryptamine, 2-phenylethylamine, cadaverine, putrescine, spermidine and spermine) in donkey milk samples. The method involves donkey milk pre-treatment to remove proteins and pre-column dansylation of the amines. HPLC in reversed phase mode has been used for bioactive amines separation and the operating condition of the APCI-MS system proved to be powerful and very efficient for peak assignment. The separation was accomplished in a short time with an excellent resolution for all the amine peaks. Quantification was carried out by monitoring the characteristic [M+H](+) ion of each amine derivative. The method sensitivity, linearity and repeatability were assayed with satisfactory results. The detection limits of the analysed amines ranged from 0.5 microg L(-1) to 15 microg L(-1); the highest LOD was for spermine. Also remarkably good recovery values were obtained; at the lowest spiking level (1 microg L(-1)) the percent mean recoveries ranged from 77.7 to 109.7. Furthermore, as the investigations relate to a complex matrix as donkey milk, suitable studies on matrix effect were performed. Finally, the developed and validated method was applied to analyse 13 donkey milk samples. Among the identified bioactive amines, putrescine, spermine and spermidine proved to be the main amines in donkey milk. Their concentration levels in the present study were lower than the values determined in mature human, cow and sow milk.

  3. One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

    Science.gov (United States)

    Peshkov, Roman Yu; Chunyan, Wang; Tretyakov, Evgeny V; Shteingarts, Vitalij D

    2016-01-01

    Summary A convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups, fluorine atoms, and a 1-cyanonaphthalene residue. The variety of ω-substituted alkyl bromides, including an extra bromine atom, a double bond, cyano and ester groups, as well as a 1,3-dioxane fragment are suitable as alkylation reagents. PMID:27559409

  4. One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

    Directory of Open Access Journals (Sweden)

    Roman Yu. Peshkov

    2016-07-01

    Full Text Available A convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups, fluorine atoms, and a 1-cyanonaphthalene residue. The variety of ω-substituted alkyl bromides, including an extra bromine atom, a double bond, cyano and ester groups, as well as a 1,3-dioxane fragment are suitable as alkylation reagents.

  5. Determination of Trace Amount of Polycyclic Aromatic Hydrocarbons in Urban Sewage by Solid-phase Extraction Coupled with High Performance Liquid Chromatograph

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From the aspects of solid-phase extraction column,elution solvent,elution volume,elution speed and so forth,the test conditions of SPE-HPLC method were optimized,and trace amount of PAHs in urban sewage was determined.[Result] The optimized solid-phase extraction conditions were SUPELCLEAN LC-18 so...

  6. Determination of polycyclic aromatic hydrocarbons in fractions in asphalt mixtures using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Nascimento, Paulo Cicero; Gobo, Luciana Assis; Bohrer, Denise; Carvalho, Leandro Machado; Cravo, Margareth Coutinho; Leite, Leni Figueiredo Mathias

    2015-07-01

    An analytical method using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization for the determination of polycyclic aromatic hydrocarbons in asphalt fractions has been developed. The 14 compounds determined, characterized by having two or more condensed aromatic rings, are expected to be present in asphalt and are considered carcinogenic and mutagenic. The parameters of the atmospheric pressure chemical ionization interface were optimized to obtain the highest possible sensitivity for all of the compounds. The limits of detection ranged from 0.5 to 346.5 μg/L and the limits of quantification ranged from 1.7 to 1550 μg/L. The method was validated against a diesel particulate extract standard reference material (NIST SRM 1975), and the obtained concentrations agreed with the certified values. The method was applied to asphalt samples after its fractionation according to ASTM D4124 and the method of Green. The concentrations of the seven polycyclic aromatic hydrocarbons quantified in the sample ranged from 0.86 mg/kg for benzo[ghi]perylene to 98.32 mg/kg for fluorene.

  7. Determination of 10 heterocyclic aromatic amines in beef jerky by high performance liquid chromatography%高效液相色谱法测定牛肉干制品中10种杂环胺

    Institute of Scientific and Technical Information of China (English)

    万可慧; 彭增起; 邵斌; 姚瑶; 石金明

    2012-01-01

    An analytical method was developed for the simultaneous determination of 10 heterocyclic aromatic amines (HAAs) in beef jerky by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The HAAs were eluted from an Extrelut NT 20 SPE column with 60 mL dichlormethane (containing 5% toluene), and then the extract was purified with a prop-ylsulfonic acid silica (PRS) column and a C18 SPE column, and finally, the HAAs were stored in a methanol-ammonia solution. The separation was achieved by using a TSK-gel ODS-80? Column and a gradient elution with the mobile phases of acetonitrile and 0. 05 mol/L acetic acid-ammonium acetate buffer (pH 3. 5). The identification and quantitative analysis of the HAAs fraction were carried out using an HPLC system with ultraviolet-fluorescence detectors. The results showed that the correlation coefficients of the 10 HAAs were all above 0. 999 and the limits of detection were in the range from 0. 02 to 2.46 ng/g. The recoveries of the 10 HAAs spiked in beef samples were 61. 69% - 101. 81% with the relative standard deviations ( RSDs) between 0.28% and 7. 81%. L-Methyl-9H-pyrido[4,3-b]indole (Harman) and 9H-pyrido[4,3-b]indole (Norharman) were detected in all beef jerky, and the total HAAs content of beef jerky were between 16. 65 and 60. 38 ng/g. This method is with wide linear range and high sensitivity , and is enough for the analysis of the HAAs in actual meat samples.%建立了固相萃取-高效液相色谱同时分析牛肉干制品中10种杂环胺含量的方法.样品经二氯甲烷(含5%甲苯)萃取,丙基磺酸( PRS)柱和C18固相萃取小柱净化后,以甲醇-氨水定容,经TSK-gel ODS-80TM色谱柱分析,采用乙腈和0.05 mol/L醋酸-醋酸铵缓冲液(pH 3.5)作为流动相进行梯度洗脱,紫外-荧光检测器的串联方式检测杂环胺含量.结果表明,10种杂环胺在线性范围内线性关系良好,相关系数r >0.999,检出限为0.02 ~ 2.46 ng/g.杂环胺的加标回收率为61

  8. EVIDENCE FOR THE PRESENCE OF MUTAGENIC ARYL AMINES IN HUMAN BREAST MILK AND DNA ADDUCTS IN EXFOLIATED BREAST-DUCT EPITHELIAL CELLS

    Science.gov (United States)

    Aromatic (AA) and heterocyclic amines (HAA) are ubiquitous environmental mutagens present in combustions emissions, fried meats, tobacco smoke, etc., and are suspect human mammary carcinogens. To determine the presence of aryl amines in breast tissue and fluid, we examined exfol...

  9. Amine-free approach toward N-toluenesulfonyl amidine construction: a phosphite-mediated Beckmann-like coupling of oximes and p-toluenesulfonyl azide.

    Science.gov (United States)

    Fleury, Lauren M; Wilson, Erin E; Vogt, Monika; Fan, Tiffany J; Oliver, Allen G; Ashfeld, Brandon L

    2013-10-25

    Atom hopping: A chlorophosphite-mediated Beckmann ligation of oximes and p-toluenesulfonyl azide gives access to N-sulfonyl phosphoramidines in good to excellent yields. The reaction proceeds under exceptionally mild conditions and constitutes a bioorthogonal approach toward amidines by avoiding the use of amines and transition-metal catalysts. dmp-ol=3,3-dimethylpropanediol.

  10. Simultaneous determination of ten biogenic amines in a thymopolypeptides injection using ultra-performance liquid chromatography coupled with electrospray ionization tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Yong; Yang, Huaxin; Liao, Haiming; Fan, Huihong; Liang, Chenggang; Deng, Lijuan; Jin, Shaohong

    2013-06-15

    A selective and sensitive ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-MS) method was developed for the simultaneous determination of ten biogenic amines (tryptamine, 2-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, adrenaline, dopamine and spermine) in a thymopolypeptides injection from the Chinese market for the first time. Biogenic amines (BAs) were pre-column derivatised by dansyl chloride after direct sample dilution. Dansylated amines were separated on an ACQUITY UPLC BEH Shield RP18 column (2.1mm×150mm I.D., 1.7μm) using a gradient elution. Quantification was done by monitoring fragment ions of each derivative under the MS mode of multiple reaction monitoring (MRM). A satisfactory result of method validation was obtained. The linearity ranged from 0.32 to 1182.9μg/L and the correlation coefficients (r) for all amines were above 0.99. The LOD ranged from 0.08μg/L for 2-phenylethylamine and tyramine to 8.00μg/L for adrenaline; the LOQ ranged from 0.32μg/L for 2-phenylethylamine to 12.12μg/L for dopamine. The recovery ranged from 75.8 to 110.3% after spiking standard solutions of BAs to a sample at three levels. The intra and inter-day precision RSD were 0.78-8.85% and 1.39-9.93% respectively. Eighty-four injections were analyzed by this method. Nine biogenic amines were found in them except adrenaline. Moreover, the relationship between the result of test for depressor substances and the content of BAs was statistically analyzed.

  11. Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent-free conditions

    Institute of Scientific and Technical Information of China (English)

    Heshmatollah; Alinezhad; Mahmood; Tajbakhsh; Neda; Hamidi

    2010-01-01

    A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH_4/silica chloride at room temperature,afforded excellent yield of the corresponding amines.

  12. Determination of polycyclic aromatic hydrocarbons in soy isoflavone nutraceutical products by gas chromatography coupled to triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Ruiz-Delgado, Ana; Martínez-Domínguez, Gerardo; Romero-González, Roberto; López-Ruiz, Rosalía; Frenich, Antonia Garrido

    2016-02-01

    Thirteen polycyclic aromatic hydrocarbons have been determined in soy-based nutraceutical products. First, an optimization of extraction procedure was performed, and a solid-liquid extraction assisted by sonication and a dilute and shoot procedure were compared, selecting the dilute and shoot approach for the extraction of target compounds, utilizing a mixture of acetone/n-hexane (1:1 v/v) as extractant solvent. After this, a clean-up step was needed bearing in mind the complexity of these matrices. Dispersive solid-phase extraction, using a mixture of C18 and Zr-Sep+ (25 mg/mL each) was used. The separation was achieved by gas chromatography and detection with triple quadrupole tandem mass spectrometry. For quantification purposes, matrix-matched calibration was used. The validation was applied at three concentration levels (20, 100 and 250 μg/kg), obtaining recoveries between 70 and 120% and precision values equal to or lower than 23%. Limits of detection and quantification were below 8 and 20 μg/kg, respectively. The method was applied in 11 samples, detecting five polycyclic aromatic hydrocarbons at concentrations ranging from 4.1 to 18.5 μg/kg.

  13. Determination of minor and trace elements in aromatic spices by micro-wave assisted digestion and inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Khan, Naeem; Choi, Ji Yeon; Nho, Eun Yeong; Jamila, Nargis; Habte, Girum; Hong, Joon Ho; Hwang, In Min; Kim, Kyong Su

    2014-09-01

    This study aimed at analyzing the concentrations of 23 minor and trace elements in aromatic spices by inductively coupled plasma-mass spectrometry (ICP-MS), after wet digestion by microwave system. The analytical method was validated by linearity, detection limits, precision, accuracy and recovery experiments, obtaining satisfactory values in all cases. Results indicated the presence of variable amounts of both minor and trace elements in the selected aromatic spices. Manganese was high in cinnamon (879.8 μg/g) followed by cardamom (758.1 μg/g) and clove (649.9 μg/g), strontium and zinc were high in ajwain (489.9 μg/g and 84.95 μg/g, respectively), while copper was high in mango powder (77.68 μg/g). On the whole some of the minor and essential trace elements were found to have good nutritional contribution in accordance to RDA. The levels of toxic trace elements, including As, Cd, and Pb were very low and did not found to pose any threat to consumers.

  14. Novel proton-type ionic liquid doped polyaniline for the headspace solid-phase microextraction of amines

    Energy Technology Data Exchange (ETDEWEB)

    Ai, Youhong [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules (Ministry of Education), College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Zhao, Faqiong [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zeng, Baizhao, E-mail: bzzeng@whu.edu.cn [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2015-06-23

    Graphical abstract: The novel proton-type ionic liquid (1-sulfobutyl-3-methylimidazolium hydrosulfate) doped polyaniline coating showed granular porous nanostructure and it had high self-EF values and extraction efficiency for amines. - Highlights: • A proton-type ionic liquid-doped polyaniline was fabricated by electrodeposition. • It showed porous granular nanostructure and had large specific surface. • It had high extraction capacity to aromatic amines. • A reasonable self-enrichment factor of SPME fiber has been proposed. - Abstract: A novel proton-type ionic liquid doped polyaniline (HIL-doped PANI) coating was presented, which was prepared on a stainless steel wire by electrodeposition in an aqueous solution containing aniline and 1-sulfobutyl-3-methylimidazolium hydrosulfate. The HIL-doped PANI coating showed granular nanostructure and had large specific surface. When it was applied to the headspace solid-phase microextraction of several amines (i.e., aniline, N-methylaniline, 3-methylaniline, 2-chloroaniline and 3-chloroaniline), it showed high extraction efficiency. The enrichment factors were 191.8–343.9 for different amines, much higher than those of common PANI and commercial polydimethylsiloxane/divinylbenzene coatings. Coupled with gas chromatographic analysis, the linear ranges were 0.097–100 μg/L with correlation coefficients above 0.9942, and the detection limits were 0.012–0.048 μg/L (S/N = 3) for different amines. The relative standard deviations (RSD) were smaller than 8.1% for five successive measurements with single fiber and the fiber-to-fiber RSDs were 8.6–13.8% (n = 5) for these amines. The proposed method was successfully applied to the extraction and determination of amines in organic waste water samples, and the recoveries were 78.3–112.8% for different analytes.

  15. Analysis of Naturally Occurring Phenolic Compounds in Aromatic Plants by RP-HPLC Coupled to Diode Array Detector (DAD and GC-MS after Silylation

    Directory of Open Access Journals (Sweden)

    Charalampos Proestos

    2013-03-01

    Full Text Available The following aromatic plants of Greek origin, Origanum dictamnus (dictamus, Eucalyptus globulus (eucalyptus, Origanum vulgare L. (oregano, Mellisa officinalis L. (balm mint and Sideritis cretica (mountain tea, were examined for the content of phenolic substances. Reversed phase HPLC coupled to diode array detector (DAD was used for the analysis of the plant extracts. The gas chromatography-mass spectrometry method (GC-MS was also used for identification of phenolic compounds after silylation. The most abundant phenolic acids were: gallic acid (1.5–2.6 mg/100 g dry sample, ferulic acid (0.34–6.9 mg/100 g dry sample and caffeic acid (1.0–13.8 mg/100 g dry sample. (+-Catechin and (−-epicatechin were the main flavonoids identified in oregano and mountain tea. Quercetin was detected only in eucalyptus and mountain tea.

  16. Palladium complexes of abnormal N-heterocyclic carbenes as precatalysts for the much preferred Cu-free and amine-free Sonogashira coupling in air in a mixed-aqueous medium.

    Science.gov (United States)

    John, Alex; Shaikh, Mobin M; Ghosh, Prasenjit

    2009-12-21

    A series of new PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) themed precatalysts of abnormal N-heterocyclic carbenes for the highly desirable Cu-free and amine-free Sonogashira coupling in air in a mixed-aqueous medium is reported. Specifically, the PEPPSI themed (NHC)PdI2(pyridine) type precatalysts, 1b-4b, efficiently carried out the highly convenient Cu-free and amine-free Sonogashira coupling of aryl bromides and iodides with terminal acetylenes in air in a mixed aqueous medium. Complexes, 1b-4b, were synthesized by the direct reaction of the corresponding imidazo[1,2-a]pyridinium iodide salts, 1a-4a, with PdCl2 in pyridine in the presence of K2CO3 as a base while the imidazo[1,2-a]pyridinium iodide salts, 1a-4a, were in turn synthesized by the alkylation reactions of the respective imidazo[1,2-a]pyridine derivatives with alkyl iodides. The density functional theory (DFT) studies revealed that these imidazol-3-ylidene[1,2-a]pyridine derived abnormal carbenes are strongly sigma-donating and consequently significantly weaken the catalytically important labile trans pyridine ligand in 1b-4b.

  17. Determination of biogenic amines in canned fish samples using head-space solid phase microextraction based on nanostructured polypyrrole fiber coupled to modified ionization region ion mobility spectrometry.

    Science.gov (United States)

    Parchami, Razieh; Kamalabadi, Mahdie; Alizadeh, Naader

    2017-01-20

    The head-space solid phase microextraction (HS-SPME) was applied to extraction and determination of histamine (HIS), putrescine (PUT), cadaverine (CAD), tyramine (TYR) in canned fish samples by ion mobility spectrometry (IMS) without any derivatization process. HIS and CAD have the same mobilities in nitrogen as buffer gas and their corresponding peaks are severely overlapped in ion mobility spectrum. Peak separation was acquired in the presence of 18-crown-6 vapor as complexation reagent into carrier gas and modified ionization region of IMS (MIR-IMS) at optimum flow rate. The interaction between 18-crown-6 and the mentioned amines forms nanocluster product ions with different cross section areas and ion mobilities. The effects of main extraction parameters on the efficiency of HS-SPME-MIR-IMS were investigated and optimized. Relative standard deviations (RSD%) of the biogenic amines determination at 50μgL(-1) concentration level were obtained in range 5.7%-6.3%. Limits of detection for analytes were in the range of 0.6-1ngg(-1). HS-SPME-MIR-IMS results indicate that the proposed method can be successfully used in biogenic amines analysis in water and food samples. Method validation was conducted by comparing our results with those obtained through GC-MS method.

  18. Reduction of Sulphur-containing Aromatic Nitro Compounds with Hydrazine Hydrate over Iron(Ⅲ) Oxide-MgO Catalyst

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron(Ⅲ) oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.

  19. 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

  20. N-heterocyclic carbene copper(I) catalysed N-methylation of amines using CO2

    KAUST Repository

    Santoro, Orlando

    2015-09-30

    The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(I) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.

  1. Nickel-Catalyzed Synthesis of Primary Aryl and Heteroaryl Amines via C–O Bond Cleavage

    KAUST Repository

    Yue, Huifeng

    2017-03-13

    A nickel-catalyzed protocol for the conversion of aryl and heteroaryl alcohol derivatives to primary and secondary aromatic amines via C(sp2)-O bond cleavage is described. The new amination protocol can be applied to a range of substrates bearing diverse functional groups and uses readily available benzophenone imines as an effective nitrogen source.

  2. Tri-n-butylphosphane catalyzed ring opening of aziridines with secondary amines

    Institute of Scientific and Technical Information of China (English)

    Wan Xuan Zhang; Li Su; Wei Gang Hu; Jie Zhou

    2012-01-01

    Ring opening of aziridine with dialkyl amine took place readily in the presence of catalytic amounts of tri-n-butylphosphane (10 mol%) in the mixture of CH3CN/H2O (10:1),giving corresponding vicinal diamines in mediate to high yields (58-95%) with good regioselecfivifie,while aromatic secondary amine could not react under the same condifions.Tti-n-butylphosphane exhibited different catalytic selectivity to amines from Lewis acid catalysts.

  3. A facile protocol for N-Cbz protection of amines in PEG-600

    Institute of Scientific and Technical Information of China (English)

    Chun Lin Zhang; Dong Feng Zhang; Hong Yi Zhao; Zi Yun Lin; Hai Hong Huang

    2012-01-01

    An efficient and eco-friendly protocol for the chemoselective N-benzyloxycarbonylation of amines was described.The reaction of amines with benzyl chloroformate (Cbz-Cl) in the presence of PEG-600 at room temperature afforded the corresponding N-Cbz derivatives in excellent yields.The method is applicable to the N-Cbz protection of aliphatic (acyclic and cyclic) and aromatic amines.

  4. Monobromination of Activated Aromatic Compounds withPolyvinylbenzyltriphenylphosphonium Supported Tribromide

    Institute of Scientific and Technical Information of China (English)

    WU Ming-Hu; YANG Gui-Chun; CHEN Zu-Xing

    2001-01-01

    Chloromethylated crosslinked co-polyvinylbenzene-divinylber-zene (2% DVB) was treated with triphenylphospbhie and then with sodium bromate and hydrobromic acid to afford red col-ored insoluble polyvinylbenzyltriphenylphosphon supportedtribromide.This reagent could be used as a mild and efficient monobrominating reagent for activated aromatic compounds such as phenols,aromatic,aromatic amines and acety-lanilines with good yields and high para-selectivity.

  5. 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.

  6. Hf(NMe2)4-Catalyzed aza-Michael addition of aromatic amines and acrylates%Hf(NMe2)4催化下芳香胺与丙烯酸叔丁酯的氮杂迈克加成反应

    Institute of Scientific and Technical Information of China (English)

    王凯; 李玉峰; 潘毅; 陈强; 庄韦; 冯美丽; 朱红军

    2013-01-01

    研究了以Hf(NMe2)4为催化剂的芳香胺与丙烯酸叔丁酯的氮杂迈克加成反应,讨论了催化反应过程中催化剂用量,反应温度,以及芳胺取代基对反应收事的影响.利用该方法合成了6种取代的氮杂加成产物,并对反应条件进行优化,使收率在18 ~63%之间.研究发现,芳香胺上取代基的给电子能力越强,反应收率越高,产物结构经1H NMR,13C NMR表征,证明为目标产物.%Hf(NMe2)4 were used as catalysts to study the aza-michael addition between arylamines with different electronic effect groups and tert-butyl acrylate. It is found that the aromatic amines can only react with one molecule of acrylate to generate secondary amines. Being catalyzed by Hf( NME2)4, in toluene,under 100 ℃,tert-butyl acrylate were reacted with six kinds of arylamines with different electronic effect substituent groups. We find that,the stronger the electron capacity of the substituent,the higher the yield of the reaction(from 18% to 63% ). The products were characterized by 1H NMR and 13C NMR,there were proved to be the target compounds.

  7. Synthesis and characterization of bisoxazolines- and pybox-copper(II) complexes and their application in the coupling of α-carbonyls with functionalized amines

    KAUST Repository

    Jia, Weiguo

    2014-01-01

    Binuclear complexes [{(DMOX)CuCl}2(μ-Cl)2] (1), mononuclear complexes [(DMOX)CuBr2] (2) (DMOX = 4,5-dihydro-2-(4,5- dihydro-4,4-dimethyloxazol-2-yl)-4,4-dimethyloxazole) and the pybox Cu(ii) complex [(Dm-Pybox)CuBr2] (3) (Dm-Pybox = 2,6-bis[4′,4′- dimethyloxazolin-2′-yl]pyridine) were obtained by reactions of CuX 2 (X = Cl, Br) with DMOX and Dm-Pybox ligands, respectively. The molecular structures of 1, 2 and 3 have been determined by single-crystal X-ray diffraction analyses. The complexes 2 and 3 are efficient in catalyzing α-amination of ketones and esters through α-bromo carbonyl intermediate. The procedures are environmentally benign methods using molecular oxygen as an oxidant with water as the only byproduct. This journal is © the Partner Organisations 2014.

  8. Coupling of homogeneous liquid-liquid extraction and dispersive liquid-liquid microextraction for the extraction and preconcentration of polycyclic aromatic hydrocarbons from aqueous samples followed by GC with flame ionization detection.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Khiavi, Elahe Behboudi; Khorram, Parisa; Mogaddam, Mohammad Reza Afshar

    2017-01-01

    In the present study, a simple and rapid method for the extraction and preconcentration of some polycyclic aromatic hydrocarbons in water samples has been developed. In this method, two sample preparation methods were combined to obtain high extraction recoveries and enrichment factors for sensitive analysis of the selected analytes. In the first stage of the method, a homogeneous solution containing an aqueous solution and cyclohexyl amine is broken by the addition of a salt. After centrifugation, the upper collected phase containing the extracted analytes is subjected to the following dispersive liquid-liquid microextraction method. Rapid injection of the mixture of cyclohexyl amine resulted from the first stage and 1,1,2-trichloroethane (as an extraction solvent) into an acetic acid solution is led to form a cloudy solution. After centrifuging, the fine droplets of the extraction solvent are settled down in the bottom of the test tube, and an aliquot of it is analyzed by gas chromatography. Under the optimum extraction conditions, enrichment factors and limits of detection for the studied analytes were obtained in the ranges of 616-752 and 0.08-0.20 μg/L, respectively. The simplicity, high extraction efficiency, short sample preparation time, low cost, and safety demonstrated the efficiency of this method relative to other approaches.

  9. Determination of polycyclic aromatic hydrocarbons in coffee and tea samples by magnetic solid-phase extraction coupled with HPLC-FLD.

    Science.gov (United States)

    Shi, Yating; Wu, Hao; Wang, Chaoqiong; Guo, Xiaozhen; Du, Juanli; Du, Liming

    2016-05-15

    This study reports the synthesis of a benign nano-adsorbent based on an ionic liquid of immobilized Fe3O4@3-(Trimethoxysilyl)propyl methacrylate@ionic liquid magnetic nanoparticles (Fe3O4@MPS@IL NPs). This material was applied to the magnetic solid phase extraction of seven heavy molecular weight polycyclic aromatic hydrocarbons (PAHs) from coffee and tea samples for high performance liquid chromatography coupled with fluorescence detection. The effects of various parameters of the analytical method were investigated, including pH, sorbent amount, desorption solvent, desorption volume, and extraction and desorption time. Under the optimized conditions, good linearities were obtained, with correlation coefficients (R(2)) between 0.9987 and 0.9998. The detection limits of the proposed method were in the range of 0.1-10ngL(-1). The spiked recoveries of the seven PAHs in coffee and tea samples ranged from 87.5% to 104.5%, with RSDs of less than 3.7%. In addition, a satisfactory reproducibility was achieved, with intra- and inter-day precisions with RSDs of less than 3.1% and 3.8%, respectively.

  10. Elucidation of the aroma compositions of Zhenjiang aromatic vinegar using comprehensive two dimensional gas chromatography coupled to time-of-flight mass spectrometry and gas chromatography-olfactometry.

    Science.gov (United States)

    Zhou, Zhilei; Liu, Shuangping; Kong, Xiangwei; Ji, Zhongwei; Han, Xiao; Wu, Jianfeng; Mao, Jian

    2017-03-03

    In this work, a method to characterize the aroma compounds of Zhenjiang aromatic vinegar (ZAV) was developed using comprehensive two dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometry (TOFMS) and gas chromatography olfactometry (GC-O). The column combination was optimized and good separation was achieved. Structured chromatograms of furans and pyrazines were obtained and discussed. A total of 360 compounds were tentatively identified based on mass spectrum match factors, structured chromatogram and linear retention indices comparison. The most abundant class in number was ketones. A large number of esters, furans and derivatives, aldehydes and alcohols were also detected. The odor-active components were identified by comparison of the reported odor of the identified compounds with the odor of corresponding GC-O region. The odorants of methanethiol, 2-methyl-propanal, 2-methyl-butanal/3-methyl-butanal, octanal, 1-octen-3-one, dimethyl trisulfide, trimethyl-pyrazine, acetic acid, 3-(methylthio)-propanal, furfural, benzeneacetaldehyde, 3-methyl-butanoic acid/2-methyl-butanoic acid and phenethyl acetate were suspected to be the most potent. About half of them were identified as significant aroma constituents in ZAV for the first time. Their contribution to specific sensory attribute of ZAJ was also studied. The results indicated that the presented method is suitable for characterization of ZAV aroma constituents. This study also enriches our knowledge on the components and aroma of ZAV.

  11. Determination of 16 polycyclic aromatic hydrocarbons in seawater using molecularly imprinted solid-phase extraction coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Song, Xingliang; Li, Jinhua; Xu, Shoufang; Ying, Rongjian; Ma, Jiping; Liao, Chunyang; Liu, Dongyan; Yu, Junbao; Chen, Lingxin

    2012-09-15

    A method of solid-phase extraction (SPE) using molecularly imprinted polymers (MIPs) as adsorbent coupled with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of 16 types of polycyclic aromatic hydrocarbons (PAHs) in seawater samples. The MIPs were prepared through non-covalent polymerization by using the 16 PAHs mixture as a template based on sol-gel surface imprinting. Compared with the non-imprinted polymers (NIPs), the MIPs exhibited excellent affinity towards 16 PAHs with binding capacity of 111.0-195.0 μg g(-1), and imprinting factor of 1.50-3.12. The significant binding specificity towards PAHs even in the presence of environmental parameters such as dissolved organic matter and various metal ions, suggested that this new imprinting material was capable of removing 93.2% PAHs in natural seawater. High sensitivity was attained, with the low limits of detection for 16 PAHs in natural seawater ranging from 5.2-12.6 ng L(-1). The application of MIPs with high affinity and excellent stereo-selectivity toward PAHs in SPE might offer a more attractive alternative to conventional sorbents for extraction and abatement of PAH-contaminated seawater.

  12. 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

  13. A quick method for analysis of heterocyclic amines in meat by QuEChERS coupled with LC-DAD-MS-MS.

    Science.gov (United States)

    Hsiao, Han-Yin; Chen, Bing Huei; Kao, Tsai Hua

    2017-10-03

    The traditional way to analyze heterocyclic amines (HAs) is time-consuming and uses large amounts of solvents. The objective of this study is to develop a quick and simultaneous analysis method for multiple types of HAs contained in meat products. Results showed that 20 HAs and 1 internal standard (4,7,8-TriMeIQx) can be separated within 30 min using an Inspire C18 column and a gradient solvent system containing a 10-mM ammonium acetate (pH 2.9) and acetonitrile. This process resulted in a high degree of separation. Using acetonitrile with 1% acetic acid as extraction solvent, followed PSA, MgSO4, and C18EC as purified reagent, is highly suitable for extracting HAs using QuEChERS. Tandem mass spectrometry with selected reaction monitoring mode were used for analysis, which indicated reasonable recovery (58.9-117.4%) for all 20 types of HAs along with limits of detection and quantification in the range of 0.003-0.05 ng/g and 0.01-0.05 ng/g, respectively.

  14. Analytical approach to determining human biogenic amines and their metabolites using eVol microextraction in packed syringe coupled to liquid chromatography mass spectrometry method with hydrophilic interaction chromatography column.

    Science.gov (United States)

    Konieczna, Lucyna; Roszkowska, Anna; Synakiewicz, Anna; Stachowicz-Stencel, Teresa; Adamkiewicz-Drożyńska, Elżbieta; Bączek, Tomasz

    2016-04-01

    Analysis of biogenic amines (BAs) in different human samples provides insight into the mechanisms of various biological processes, including pathological conditions, and thus may be very important in diagnosing and monitoring several neurological disorders and cancerous tumors. In this work, we developed a simple and fast procedure using a digitally controlled microextraction in packed syringe (MEPS) coupled to liquid chromatography mass spectrometry (LC-MS) method for simultaneous determination of biogenic amines, their precursors and metabolites in human plasma and urine samples. The separation of 12 low molecular weight and hydrophilic molecules with a wide range of polarities was achieved with hydrophilic interaction chromatography (HILIC) column without derivatization step in 12 min. MEPS was implemented using the APS sorbent in semi-automated analytical syringe (eVol(®)) and small volume of urine and plasma samples, 5 0µL and 100 μL, respectively. We evaluated important parameters influencing MEPS efficiency, including stationary phase selection, sample pH and volume, number of extraction cycles, and washing and elution volumes. In optimized MEPS conditions, the analytes were eluted by 3 × 50 μL of methanol with 0.1% formic acid. The chromatographic separation of analytes was performed on XBridge Amide™ BEH analytical column (3.0mm × 100 mm, 3.5 µm) using gradient elution with mobile phase consisting of phase A: 10mM ammonium formate buffer in water pH 3.0 and phase B: 10mM ammonium formate buffer in acetonitrile pH 3.0. The LC-HILIC-MS method was validated and, in optimum conditions, presented good linearity in concentration range within 10-2000 ng/mL for all the analytes with a determination coefficient (r(2)) higher than 0.999 for plasma and urine samples. Method recovery ranged within 87.6-104.3% for plasma samples and 84.2-98.6% for urine samples. The developed method utilizing polar APS sorbent along with polar HILIC column was applied for

  15. Efficient Synthesis of Novel Pyridine-Based Derivatives via Suzuki Cross-Coupling Reaction of Commercially Available 5-Bromo-2-methylpyridin-3-amine: Quantum Mechanical Investigations and Biological Activities.

    Science.gov (United States)

    Ahmad, Gulraiz; Rasool, Nasir; Ikram, Hafiz Mansoor; Gul Khan, Samreen; Mahmood, Tariq; Ayub, Khurshid; Zubair, Muhammad; Al-Zahrani, Eman; Ali Rana, Usman; Akhtar, Muhammad Nadeem; Alitheen, Noorjahan Banu

    2017-01-27

    The present study describes palladium-catalyzed one pot Suzuki cross-coupling reaction to synthesize a series of novel pyridine derivatives 2a-2i, 4a-4i. In brief, Suzuki cross-coupling reaction of 5-bromo-2-methylpyridin-3-amine (1) directly or via N-[5-bromo-2-methylpyridine-3-yl]acetamide (3) with several arylboronic acids produced these novel pyridine derivatives in moderate to good yield. Density functional theory (DFT) studies were carried out for the pyridine derivatives 2a-2i and 4a-4i by using B3LYP/6-31G(d,p) basis with the help of GAUSSIAN 09 suite programme. The frontier molecular orbitals analysis, reactivity indices, molecular electrostatic potential and dipole measurements with the help of DFT methods, described the possible reaction pathways and potential candidates as chiral dopants for liquid crystals. The anti-thrombolytic, biofilm inhibition and haemolytic activities of pyridine derivatives were also investigated. In particular, the compound 4b exhibited the highest percentage lysis value (41.32%) against clot formation in human blood among all newly synthesized compounds. In addition, the compound 4f was found to be the most potent against Escherichia coli with an inhibition value of 91.95%. The rest of the pyridine derivatives displayed moderate biological activities.

  16. Efficient Synthesis of Novel Pyridine-Based Derivatives via Suzuki Cross-Coupling Reaction of Commercially Available 5-Bromo-2-methylpyridin-3-amine: Quantum Mechanical Investigations and Biological Activities

    Directory of Open Access Journals (Sweden)

    Gulraiz Ahmad

    2017-01-01

    Full Text Available The present study describes palladium-catalyzed one pot Suzuki cross-coupling reaction to synthesize a series of novel pyridine derivatives 2a–2i, 4a–4i. In brief, Suzuki cross-coupling reaction of 5-bromo-2-methylpyridin-3-amine (1 directly or via N-[5-bromo-2-methylpyridine-3-yl]acetamide (3 with several arylboronic acids produced these novel pyridine derivatives in moderate to good yield. Density functional theory (DFT studies were carried out for the pyridine derivatives 2a–2i and 4a–4i by using B3LYP/6-31G(d,p basis with the help of GAUSSIAN 09 suite programme. The frontier molecular orbitals analysis, reactivity indices, molecular electrostatic potential and dipole measurements with the help of DFT methods, described the possible reaction pathways and potential candidates as chiral dopants for liquid crystals. The anti-thrombolytic, biofilm inhibition and haemolytic activities of pyridine derivatives were also investigated. In particular, the compound 4b exhibited the highest percentage lysis value (41.32% against clot formation in human blood among all newly synthesized compounds. In addition, the compound 4f was found to be the most potent against Escherichia coli with an inhibition value of 91.95%. The rest of the pyridine derivatives displayed moderate biological activities.

  17. Biogenic amines at a low level of evolution: Production, functions and regulation in the unicellular Tetrahymena.

    Science.gov (United States)

    Csaba, György

    2015-06-01

    The unicellular eukaryote Tetrahymena synthesize, store and secrete biogenic amines (histamine, serotonin, epinephrine, dopamine, melatonin) and also can take up amines from the milieu. It also has (G-protein-coupled) receptors (binding sites) for these amines as well, as second messengers. The factors infuencing the mentioned processes are shown. For certain amines the genes and the coded enzymes are demonstrated. The amines influence phagocytosis, cell division, ciliary regeneration, glucose metabolism and chemotaxis. There are interhormone actions between the amines, and between the amines and other hormones produced by Tetrahymena. The critical review discusses the role of amines in the early stages of evolution and compares this to their functions in mammals. It tries to give answer how and why biogenic amines were selected to hormones, and why new functions formed for them in higher ranked animals, preserving also the ancient ones.

  18. Tyramine and β-phenylethylamine, from fermented food products, as agonists for the human trace amine-associated receptor 1 (hTAAR1) in the stomach.

    Science.gov (United States)

    Ohta, Hiroto; Takebe, Youhei; Murakami, Yuka; Takahama, Yusei; Morimura, Shigeru

    2017-01-13

    The aromatic amines tyramine and β-phenylethylamine are abundant in fermented foods. Recently, a family of human trace amine-associated receptors (hTAARs) was discovered that responds to these compounds. This study examined the expression of hTAAR genes in five human organs. Among them, the stomach expressed hTAAR1 and hTAAR9. Interestingly, more hTAAR1 was expressed in the pylorus than in the other stomach regions. The CRE-SEAP reporter assay revealed that only hTAAR1 functioned as a Gs-coupled receptor in response to tyramine and β-phenylethylamine stimulation. The β-phenylethylamine-mediated hTAAR1 activity could be potentiated using 3-isobutyl-1-methylxanthine. These data suggest that tyramine and β-phenylethylamine in fermented foods act at hTAAR1 as agonists in the pylorus of stomach.

  19. Method of neutralizing the corrosive surface of amine-cured epoxy resins

    Science.gov (United States)

    Lee, S. Y. (Inventor)

    1982-01-01

    The corrosive alkaline surface layer of an epoxy resin product formed by the curing of the epoxy with an aliphatic amine is eliminated by first applying a non-solvent to remove most or all of the free unreacted amine and then applying a layer of a chemical reagent to neutralize the unused amine or amine functional groups by forming a substituted urea. The surface then may be rinsed with acetone and then with alcohol. The non-solvent may be an alcohol. The neutralizing chemical reagent is a mono-isocyanate or a mono-isothiocyanate. Preferred is an aromatic mono-isocyanate such as phenyl isocyanate, nitrophenyl isocyanate and naplthyl isocyanate.

  20. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  1. 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...... in the aromatic thioester amidation reaction. Under similar conditions, cysteine-free ligation was achieved by coupling a fully side-chain protected 15 amino acid phosphopeptide thioester to the free N-terminal of a side-chain protected 9 amino acid peptide producing the corresponding 24 amino acid phosphopeptide....

  2. Efficient iodination of aromatic compounds using potassium ferrate supported on montmorillonite

    Institute of Scientific and Technical Information of China (English)

    Hoda Keipour; Mohammad A. Khalilzadeh; Bita Mohtat; Abolfazl Hosseini; Daryoush Zareyee

    2011-01-01

    Potassium ferrate impregnated on montmorillonite is a mild, cheap, and non-toxic reagent for the iodination of phenols, including naphthol, aromatic amines, and heterocyclic substrates in fair to excellent yields by a simple isolation procedure.

  3. 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.

  4. Synthesis of 3-Bromotetronamides via Amination of 3,4-Dibromofuran-2(5H)-one

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Silvio; Oliveira, Caio C., E-mail: silviodc@ufba.b [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Instituto Nacional de Ciencia e Tecnologia (INCT) em Energia, Salvador, BA (Brazil); Sabino, Jose R. [Universidade Federal de Goias (IF/UFG), Goiania (Brazil). Inst. de Fisica

    2011-07-01

    This work describes the direct synthesis of 3-bromotetronamides in good yields through the reaction of 3,4-dibromofuran-2(5H)-one, obtained from furfural, with primary and secondary amines. Aromatic amines were more tolerated than aliphatic and heteroaromatic ones. The X-ray structures of five derivatives are described. (author)

  5. Phospholipophilicity of CxHyN(+) amines : chromatographic descriptors and molecular simulations for understanding partitioning into membranes

    NARCIS (Netherlands)

    Droge, S T J; Hermens, J L M; Rabone, J; Gutsell, S; Hodges, G

    2016-01-01

    Using immobilized artificial membrane high-performance liquid chromatography (IAM-HPLC) the sorption affinity of 70 charged amine structures to phospholipids was determined. The amines contained only 1 charged moiety and no other polar groups, the rest of the molecule being aliphatic and/or aromatic

  6. Palladium-catalyzed aryl amination-heck cyclization cascade: A one-flask approach to 3-substituted Indoles

    DEFF Research Database (Denmark)

    Jensen, Thomas; Pedersen, Henrik; Bang-Andersen, B.;

    2008-01-01

    Two for the price of one: A Pd/dppf-based catalyst provides access to the title compounds from 1,2-dihalogenated aromatic compounds and allylic amines in a single reaction flask. The initial aryl amination step occurs with excellent selectivity for the aryl iodide to ensure the formation of a sin...

  7. Thieme Chemistry Journal Awardees - Where are They Now? Catalytic Transport with an Amine Carrier in a Fluorous Triphasic Reaction.

    Science.gov (United States)

    Montanari, Vittorio; Yu, Marvin S; Curran, Dennis P

    2009-03-01

    Several aromatic aldehydes are transported by a fluorous amine from one organic phase through a fluorous phase to another organic phase. The derived imines react with phenylhydrazine to immobilize the transported product as a hydrazone and release the amine for reuse. In this way, catalytic transport is accomplished for the first time.

  8. Biogenic amines in beer

    OpenAIRE

    Čiháková, Dagmar

    2016-01-01

    This thesis deals with the technological process of brewing beer, describes the raw materials needed for its production, and points out the useful and harmful substances contained in beer as biogenic amines (BA). Furthermore, there are described the issues of biogenic amines in food and primarily in beer, which is a histamine, putrescine, cadaverine, tyramine and tryptamine. In the practical section BA was determined in lager bottom-fermented beers from local microbreweries and large industri...

  9. HSiCl3-Mediated Reduction of Nitro-Derivatives to Amines: Is Tertiary Amine-Stabilized SiCl2 the Actual Reducing Species?

    Science.gov (United States)

    Orlandi, Manuel; Benaglia, Maurizio; Tosi, Filippo; Annunziata, Rita; Cozzi, Franco

    2016-04-01

    The mechanism of a recently reported, highly chemoselective metal-free protocol of wide general applicability for the reduction of aromatic and aliphatic nitro-derivatives to amines has been investigated. The reaction is supposed to occur through the generation of a Si(II) reducing species; quantum mechanical calculations, and spectroscopic and experimental data strongly suggest the tertiary amine-stabilized dichlorosilylene to be the most probable reducing agent.

  10. Conversion of alcohols to enantiopure amines through dual enzyme hydrogen-borrowing cascades

    Science.gov (United States)

    Mutti, Francesco G.; Knaus, Tanja; Scrutton, Nigel S.; Breuer, Michael; Turner, Nicholas J.

    2016-01-01

    α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds on industrial scale. Here we present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on the combination of an alcohol dehydrogenase (ADHs from Aromatoleum sp., Lactobacillus sp. and Bacillus sp.) enzyme operating in tandem with an amine dehydrogenase (AmDHs engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols (up to 96% conversion and 99% enantiomeric excess). Furthermore, primary alcohols are aminated with high conversion (up to 99%). This redox self-sufficient network possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. PMID:26404833

  11. Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades.

    Science.gov (United States)

    Mutti, Francesco G; Knaus, Tanja; Scrutton, Nigel S; Breuer, Michael; Turner, Nicholas J

    2015-09-25

    α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product.

  12. Determination of polycyclic aromatic hydrocarbons in olive oil by a completely automated headspace technique coupled to gas chromatography-mass spectrometry.

    Science.gov (United States)

    Arrebola, Francisco J; Frenich, A Garrido; González Rodríguez, Manuel J; Bolaños, Patricia Plaza; Martínez Vidal, José L

    2006-06-01

    A new and completely automated method for the determination of ten relevant polycyclic aromatic hydrocarbons (PAHs) in olive oil is proposed using an extraction by the headspace (HS) technique. Quantification and confirmation steps are carried out by gas chromatography-mass spectrometry (GC-MS) combining simultaneously selected-ion monitoring (SIM) and tandem mass spectrometry (MS/MS). This combination offers on one hand an increased sensitivity and on the other hand, selective and reliable qualitative information. Sample pretreatment or clean-up are not necessary because the olive oil sample is put directly into an HS vial, automatically processed by HS and introduced into the GC-MS instrument for analysis. Because of its high selectivity and sensitivity, a triple-quadrupole (QqQ) detector coupled with the gas chromatograph allows us to limit handling. Each sample is completely processed in approximately 63 min (45 min for HS isolation and 18 min for GC-MS determination), a reduced time compared with previously published methods. The chemical and instrumental variables were preliminarily optimized using uncontaminated olive oil samples spiked with 25 microg kg(-1) of each target compound. The final method was validated to ensure the quality of the results. The precision was satisfactory, with relative standard deviation (RSD) values in the range 3-9%. Recovery rates ranged from 96 to 99%. Limits of detection (LOD) were calculated as 0.02-0.06 microg kg(-1) and the limits of quantification (LOQ) were obtained as 0.07-0.26 microg kg(-1). It must be mentioned that the LOD and LOQ are much lower than the maximum levels established by the European Union (EU) in oils and fats intended for direct human consumption or for use as an ingredient in foods, which are set at 2 microg kg(-1). All the figures of merit are completely in accordance with the latest EU legislation. This fact makes it possible to consider the proposed method as a useful tool for the control of PAHs in

  13. Direct-immersion solid-phase microextraction coupled to fast gas chromatography mass spectrometry as a purification step for polycyclic aromatic hydrocarbons determination in olive oil.

    Science.gov (United States)

    Purcaro, Giorgia; Picardo, Massimo; Barp, Laura; Moret, Sabrina; Conte, Lanfranco S

    2013-09-13

    The aim of the present work was to optimize a preparation step for polycyclic aromatic hydrocarbons in a fatty extract. Solid-phase microextraction is an easy preparation technique, which allows to minimize solvent consumption and reduce sample manipulation. A Carbopack Z/polydimethylsiloxane fiber, particularly suitable for extraction of planar compounds, was employed to extract polycyclic aromatic hydrocarbons from a hexane solution obtained after a previous extraction with acetonitrile from oil, followed by a liquid-liquid partition between acetonitrile and hexane. The proposed method was a rapid and sensitive solution to reduce the interference of triglycerides saving the column life and avoiding frequent cleaning of the mass spectrometer ion source. Despite the non-quantitative extraction of polycyclic aromatic hydrocarbons from oil using acetonitrile, the signal-to-noise ratio was significantly improved obtaining a limit of detection largely below the performance criteria required by the European Union legislation.

  14. Simultaneous determination of 33 primary aromatic amines in polystyrene and polyethylene masterbatches for foods by ultra-performance liquid chromatography-tandem mass spectrometry%超高效液相色谱-串联质谱法同时测定食品级聚苯乙烯和聚乙烯色母粒中33种初级芳香胺

    Institute of Scientific and Technical Information of China (English)

    满正印; 王全林; 李和生; 张爱芝; 沈坚

    2015-01-01

    建立了超高效液相色谱-三重四极杆质谱( UPLC-MS/MS)同时测定食品级聚苯乙烯( PS)和聚乙烯( PE)色母粒中33种初级芳香胺( PAAs)的检测方法。PS色母粒用二氯甲烷溶解,超声提取后加入甲醇沉淀,并将提取液过石墨化碳固相萃取柱净化;PE色母粒用二氯甲烷超声溶胀提取;将 PS 色母粒过柱液和 PE 色母粒提取液浓缩,浓缩液用甲醇-水(1:9,v/v)定容至2 mL,0.22μm膜过滤后上机检测。采用 BEH Phenyl色谱柱(100 mm ×2.1 mm,1.7μm),以0.07%(v/v)甲酸甲醇溶液-水(1:9,v/v)为流动相,梯度洗脱分离,UPLC-MS/MS 多反应监测( MRM)模式检测,同位素内标法定量。优化了色谱分离条件、质谱碎裂电压、碰撞能量等,并考察了提取时间、提取溶剂、浓缩方式等对回收率的影响。33种 PAAs的方法检出限为6~10μg/kg,定量限为20~30μg/kg,2种不同基质样品在20、100、200μg/kg等3个添加水平的平均回收率为61.3%~119.8%,相对标准偏差( RSD)为1.4%~14.8%。本方法操作简便、快速、准确、灵敏度高,能满足相关测定要求。%A comprehensive analytical method based on ultra-performance liquid chromatogra-phy coupled with triple quadrupole mass spectrometry( UPLC-MS/MS)has been developed for the simultaneous determination of 33 primary aromatic amines( PAAs)in polystyrene( PS)and polyethylene( PE)masterbatches for foods. The PS masterbatches were dissolved with dichlo-romethane,and methanol was added to precipitate after extraction by ultrasound extraction. Then the extract was purified by passing through a carbon graphite solid phase extraction col-umn. The PE masterbatches were swelled and extracted with dichloromethane by ultrasound. The purified PS solution and PE extract were concentrated,and diluted to 2 mL with methanol-water(1:9,v/v),and filtered through the membranes of 0. 22

  15. Aromatic graphene

    Science.gov (United States)

    Das, D. K.; Sahoo, S.

    2016-04-01

    In recent years graphene attracts the scientific and engineering communities due to its outstanding electronic, thermal, mechanical and optical properties and many potential applications. Recently, Popov et al. [1] have studied the properties of graphene and proved that it is aromatic but without fragrance. In this paper, we present a theory to prepare graphene with fragrance. This can be used as scented pencils, perfumes, room and car fresheners, cosmetics and many other useful household substances.

  16. Aromatic graphene

    Energy Technology Data Exchange (ETDEWEB)

    Das, D. K., E-mail: gour.netai@gmail.com [Department of Metallurgical and Material Science Engineering, National Institute of Technology Durgapur-713209, West Bengal (India); Sahoo, S., E-mail: sukadevsahoo@yahoo.com [Department of Physics, National Institute of Technology Durgapur-713209, West Bengal (India)

    2016-04-13

    In recent years graphene attracts the scientific and engineering communities due to its outstanding electronic, thermal, mechanical and optical properties and many potential applications. Recently, Popov et al. [1] have studied the properties of graphene and proved that it is aromatic but without fragrance. In this paper, we present a theory to prepare graphene with fragrance. This can be used as scented pencils, perfumes, room and car fresheners, cosmetics and many other useful household substances.

  17. Dehalogenation of aromatics by nucleophilic aromatic substitution.

    Science.gov (United States)

    Sadowsky, Daniel; McNeill, Kristopher; Cramer, Christopher J

    2014-09-16

    Nucleophilic aromatic substitution has been implicated as a mechanism for both the biotic and abiotic hydrodehalogenation of aromatics. Two mechanisms for the aqueous dehalogenation of aromatics involving nucleophilic aromatic substitution with hydride as a nucleophile are investigated using a validated density functional and continuum solvation protocol. For chlorinated and brominated aromatics, nucleophilic addition ortho to carbon-halogen bonds via an anionic intermediate is predicted to be the preferred mechanism in the majority of cases, while concerted substitution is predicted to be preferred for most fluorinated aromatics. Nucleophilic aromatic substitution reactions with the hydroxide and hydrosulfide anions as nucleophiles are also investigated and compared.

  18. A protocol for amide bond formation with electron deficient amines and sterically hindered substrates

    DEFF Research Database (Denmark)

    Due-Hansen, Maria E; Pandey, Sunil K; Christiansen, Elisabeth;

    2016-01-01

    A protocol for amide coupling by in situ formation of acyl fluorides and reaction with amines at elevated temperature has been developed and found to be efficient for coupling of sterically hindered substrates and electron deficient amines where standard methods failed....

  19. Selective Hydrogenation of Nitriles to Primary Amines by using a Cobalt Phosphine Catalyst.

    Science.gov (United States)

    Adam, Rosa; Bheeter, Charles Beromeo; Cabrero-Antonino, Jose R; Junge, Kathrin; Jackstell, Ralf; Beller, Matthias

    2017-03-09

    A general procedure for the catalytic hydrogenation of nitriles to primary amines by using a non-noble metal-based system is presented. Co(acac)3 in combination with tris[2-(dicyclohexylphosphino)ethyl]phosphine efficiently catalyzes the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to give the corresponding amines. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Density Functional Investigation of Graphene Doped with Amine-Based Organic Molecules

    OpenAIRE

    Yeun Hee Hwang; Hyang Sook Chun; Kang Min Ok; Kyung-Koo Lee; Kyungwon Kwak

    2015-01-01

    To improve the electronic properties of graphene, many doping techniques have been studied. Herein, we investigate the electronic and molecular structure of doped graphene using density functional theory, and we report the effects of amine-based benzene dopants adsorbed on graphene. Density functional theory (DFT) calculations were performed to determine the role of amine-based aromatic compounds in graphene doping. These organic molecules bind to graphene through long-range interactions such...

  1. Samarium-promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    ZHENG,Xing-Liang(郑兴良); ZHANG,Yong-Min(张永敏)

    2002-01-01

    The differently substituted aromatic nitro compoumds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN,-NHTos and - alkyl, remained intact. The notable advantagesofthis reaction areits mild conditions, simple operaton,short reaction time, high yields and easy recycling of ionic liquid.

  2. High capacity immobilized amine sorbents

    Science.gov (United States)

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Filburn, Thomas

    2007-10-30

    A method is provided for making low-cost CO.sub.2 sorbents that can be used in large-scale gas-solid processes. The improved method entails treating an amine to increase the number of secondary amine groups and impregnating the amine in a porous solid support. The method increases the CO.sub.2 capture capacity and decreases the cost of utilizing an amine-enriched solid sorbent in CO.sub.2 capture systems.

  3. Whole cell biotransformation for reductive amination reactions

    OpenAIRE

    Klatte, Stephanie; Lorenz, Elisabeth; Wendisch, Volker F.

    2013-01-01

    Whole cell biotransformation systems with enzyme cascading increasingly find application in biocatalysis to complement or replace established chemical synthetic routes for production of, e.g., fine chemicals. Recently, we established an Escherichia coli whole cell biotransformation system for reductive amination by coupling a transaminase and an amino acid dehydrogenase with glucose catabolism for cofactor recycling. Transformation of 2-keto-3-methylvalerate to l-isoleucine by E. coli cells w...

  4. CHITOSE AMINE & BODY ACUPOINTS' COSMETOLOGY

    Institute of Scientific and Technical Information of China (English)

    TEO Gek Chun

    2002-01-01

    @@ Chitose Amine is a natural substance which the body cells will readily absorb and it helps strengthen the immune system and reduces the cholesterol. Currently. Chitose Amine has been used widely in cosmetics and detoxification foods. The mian therapeutic properties of Chitose Amine in cosmetics are as follow:

  5. Metal-ligand cooperation by aromatization-dearomatization: a new paradigm in bond activation and "green" catalysis.

    Science.gov (United States)

    Gunanathan, Chidambaram; Milstein, David

    2011-08-16

    In view of global concerns regarding the environment and sustainable energy resources, there is a strong need for the discovery of new, green catalytic reactions. For this purpose, fresh approaches to catalytic design are desirable. In recent years, complexes based on "cooperating" ligands have exhibited remarkable catalytic activity. These ligands cooperate with the metal center by undergoing reversible structural changes in the processes of substrate activation and product formation. We have discovered a new mode of metal-ligand cooperation, involving aromatization-dearomatization of ligands. Pincer-type ligands based on pyridine or acridine exhibit such cooperation, leading to unusual bond activation processes and to novel, environmentally benign catalysis. Bond activation takes place with no formal change in the metal oxidation state, and so far the activation of H-H, C-H (sp(2) and sp(3)), O-H, and N-H bonds has been demonstrated. Using this approach, we have demonstrated a unique water splitting process, which involves consecutive thermal liberation of H(2) and light-induced liberation of O(2), using no sacrificial reagents, promoted by a pyridine-based pincer ruthenium complex. An acridine pincer complex displays unique "long-range" metal-ligand cooperation in the activation of H(2) and in reaction with ammonia. In this Account, we begin by providing an overview of the metal-ligand cooperation based on aromatization-dearomatization processes. We then describe a range of novel catalytic reactions that we developed guided by these new modes of metal-ligand cooperation. These reactions include the following: (1) acceptorless dehydrogenation of secondary alcohols to ketones, (2) acceptorless dehydrogenative coupling of alcohols to esters, (3) acylation of secondary alcohols by esters with dihydrogen liberation, (4) direct coupling of alcohols and amines to form amides and polyamides with liberation of dihydrogen, (5) coupling of esters and amines to form amides

  6. Synthesis and evaluation of aromaticity and tautomerization of pyrazolopyridazin(on)es

    Indian Academy of Sciences (India)

    NURETT˙IN MENGES; ˙ISHAK BILDIRICI

    2017-06-01

    Aromaticity of pyrazolopyridazin(on)es was investigated using NICS(0), NICS(1), NICSzz(1), FIPC-NICS and HOMA aromaticity indexes and it was observed that aromaticity of pyridazin(on)es was amenable to aromaticity of pyrazole and vice versa. Some tautomeric forms of pyridazinone were analyzedand the localized orbital locator maps, electron density maps, Fuzzy, Laplacian, and Mayer bond order methods showed dominant form. Different substituents, amine, chlorine, phenyl, methyl, hydrogen, substituted-phenyl, etc. on both the rings were chosen to search out the substituent effect. Aromaticity of pyrazolopyridazin(on)es was searched out in detail for the first time.

  7. Aerosol and cloud chemistry of amines from CCS - reactivity experiments and numerical modeling

    Science.gov (United States)

    Weller, Christian; Tilgner, Andreas; Herrmann, Hartmut

    2013-04-01

    Capturing CO2 from the exhaust of power plants using amine scrubbing is a common technology. Therefore, amines can be released during the carbon capture process. To investigate the tropospheric chemical fate of amines from CO2 capturing processes and their oxidation products, the impact of aqueous aerosol particles and cloud droplets on the amine chemistry has been considered. Aqueous phase reactivity experiments of NO3 radicals and ozone with relevant amines and their corresponding nitrosamines were performed. Furthermore, nitrosamine formation and nitrosamine photolysis was investigated during laboratory experiments. These experiments implicated that aqueous phase photolysis can be an effective sink for nitrosamines and that ozone is unreactive towards amines and nitrosamines. Multiphase phase oxidation schemes of amines, nitrosamines and amides were developed, coupled to the existing multiphase chemistry mechanism CAPRAM and built into the Lagrangian parcel model SPACCIM using published and newly measured data. As a result, both deliquescent particles and cloud droplets are important compartments for the multiphase processing of amines and their products. Amines can be readily oxidised by OH radicals in the gas and cloud phase during daytime summer conditions. However, amine oxidation is restricted during winter conditions with low photochemical activity leading to long lifetimes of amines. The importance of the gas and aqueous phase depends strongly on the partitioning of the different amines. Furthermore, the simulations revealed that the aqueous formation of nitrosamines in aerosol particles and could droplets is not a relevant process under tropospheric conditions.

  8. Strong Room-Temperature Photoluminescence from the Novel Adduct of C60 with Aliphatic Amines

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Strong room-temperature photoluminescence from the adducts of C60 reacting with five different aliphatic amines, namely propylethylamine (PPA), n-butyl amine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and diethylamine (DEA), was firstly found from their toluene solution at relatively shorter wavelength around 519 nm.The fluorescence intensity has a good correlation with the length of n-alkyl group chain, the steric position and concentration of different amines and setting of solution as well as the UV-radiation. Their fluorescence quenching by concentration and by aromatic electron-donor N,N-dimethylaniline (DMA) were first investigated and determined.

  9. 液相色谱-串联质谱法测定食品接触材料中28种初级芳香胺的迁移量%Determination of Migration of 28 Primary Aromatic Amines from Food Contact Materials by Liquid Chromatography-Tandem Mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    李全忠; 周明辉; 刘莹峰; 翟翠萍; 郑建国; 王云玉

    2013-01-01

    建立了液相色谱-串联质谱法(LC-MS/MS)同时测定食品接触材料中28种初级芳香胺(PAAs)迁移量的方法.采用C3色谱柱,以甲醇-水为流动相,梯度洗脱分离,在电喷雾正离子模式下以多反应监测(MRM)方式检测,外标法定量.28种PAAs检出限(LOD,S/N=3)和定量限(LOQ,S/N=10)分别为0.02~0.3 μg/kg和0.1~ 1.0μg/kg;在1.0 ~ 1000 μg/L浓度范围内线性良好,相关系数大于0.9915;加标浓度在1.0~100 μg/kg的回收率为77.8% ~ 105.3%;相对标准偏差(RSD)为4.5% ~11.8%.本方法操作简便、快速、准确、灵敏度高,能满足相关测定要求.%A method was developed for simultaneous determination of the migration of 28 kinds of primary aromatic amines(PAAs) from food contact materials by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The analytes were separated on a C3 column,eluted by gradient with methanol and water, identified by electrospray ionization mass spectrometry in positive mode using multiple reaction monitoring ( MRM) , quantified by external standard method . The limits of detection (LOD, S/N=3) and quantification (LOQ, S/N-10) of 28 PAAs were 0.02-0.3 μg/kg and 0. 1-1.0 μg/kg, respectively. The correlation coefficients of linear calibration curve were over 0. 9915 in the ranges varied from 1. 0 μg/L to 1000 μg/L. The recoveries of PAAs were 77. 8% -105. 3% in the spiked range of 1.0-100 μg/kg, and the relative standard deviation (RSD) was 4.5%-11. 8% . The experiment results indicated that the method was simple, rapid, sensitive, accurate, and could meet the correlative requirements for determination.

  10. Selective spectrophotometric determination of some primary amines using 2,4-dinitrofluorobenzene reagent

    Directory of Open Access Journals (Sweden)

    Theia’a N. Al-Sabha

    2015-07-01

    Full Text Available A spectrophotometric method is developed for the quantitative determination of some primary aliphatic and aromatic amines, i.e., allyl amine, 1,5-diaminopentane, 1,6-diaminohexane, cyclohexylamine, m-aminophenol, benzidine and p-phenylenediamine. The method is based on the interaction between these amines and 2,4-dinitrofluorobenzene (DNFB reagent. The spectra of the products show maximum absorption that ranged from 355–357 nm and 366–377 nm with molar absorptivities that ranged from 1.086 × 104–6.398 × 104 and 7.566 × 103–1.581 × 104 l/mol cm for aliphatic and aromatic primary amines, respectively. Beer’s law is obeyed in the concentration range of 0.25–8.0, 1.0–10, 0.25–2.50, 1.0–8.0, 2.0–20, 1.0–12.0 and 1.0–10.0 μg/ml for the above mentioned amines, respectively, and the mean percent recoveries ranged between 97.8% and 103.3% with precision (RSD better than 5.5% for all the amines under study. In addition, the stability constant has been determined and the mechanism is proposed for the DNFB-amine products.

  11. Hydrothermal Reactivity of Amines

    Science.gov (United States)

    Robinson, K.; Shock, E.; Hartnett, H. E.; Williams, L. B.; Gould, I.

    2013-12-01

    The reactivity of aqueous amines depends on temperature, pH, and redox state [1], all of which are highly variable in hydrothermal systems. Temperature and pH affect the ratio of protonated to unprotonated amines (R-NH2 + H+ = R-NH3+), which act as nucleophiles and electrophiles, respectively. We hypothesize that this dual nature can explain the pH dependence of reaction rates, and predict that rates will approach a maximum at pH = pKa where the ratio of protonated and unprotonated amines approaches one and the two compounds are poised to react with one another. Higher temperatures in hydrothermal systems allow for more rapid reaction rates, readily reversible reactions, and unique carbon-nitrogen chemistry in which water acts as a reagent in addition to being the solvent. In this study, aqueous benzylamine was used as a model compound to explore the reaction mechanisms, kinetics, and equilibria of amines under hydrothermal conditions. Experiments were carried out in anoxic silica glass tubes at 250°C (Psat) using phosphate-buffered solutions to observe changes in reaction rates and product distributions as a function of pH. The rate of decomposition of benzylamine was much faster at pH 4 than at pH 9, consistent with the prediction that benzylamine acts as both nucleophile and an electrophile, and our estimate that the pKa of benzylamine is ~5 at 250°C and Psat. Accordingly, dibenzylamine is the primary product of the reaction of two benzylamine molecules, and this reaction is readily reversible under hydrothermal conditions. Extremely acidic or basic pH can be used to suppress dibenzylamine production, which also suppresses the formation of all other major products, including toluene, benzyl alcohol, dibenzylimine, and tribenzylamine. This suggests that dibenzylamine is the lone primary product that then itself reacts as a precursor to produce the above compounds. Analog experiments performed with ring-substituted benzylamine derivatives and chiral

  12. 40 CFR 721.750 - Aromatic amine compound.

    Science.gov (United States)

    2010-07-01

    ... significant new uses are: (i) Protection in the workplace. Requirements as specified in § 721.63 (a)(1), (a)(3), (b) (concentration set at 0.1 percent) and (c). (ii) Hazard communication program. Requirements as... provided with information on the location and availability of a written hazard communication program...

  13. Polycyclic amines as chloroquine resistance modulating agents in Plasmodium falciparum.

    Science.gov (United States)

    Joubert, Jacques; Kapp, Erika; Taylor, Dale; Smith, Peter J; Malan, Sarel F

    2016-02-15

    Pentacycloundecylamines (PCUs) and adamantane amines, such as NGP1-01 (1) and amantadine, have shown significant channel blocking activities. They are postulated to act as chemosensitizers and circumvent the resistance of the plasmodia parasite against chloroquine (CQ) by inhibiting the p-glycoprotein efflux pump and enabling the accumulation of CQ inside the parasite digestive vacuole. Twelve polycyclic amines containing either a PCU or adamantane amine moiety conjugated to different aromatic functionalities through various tethered linkers were selected based on their channel blocking abilities and evaluated as potential chemosensitizers. Compounds 2, 4, 5 and 10 showed significant voltage-gated calcium channel (VGCC) blocking ability (IC50=0.27-35 μM) and were able to alter the CQ IC50 in differing degrees (45-81%) in the multidrug resistant Plasmodium falciparum Dd2 isolate. Among them, the PCU-dansyl amine compound (4) displayed the best potential to act as a chemosensitizer against the Dd2 strain at a 1 μM concentration (RMI=0.19) while displaying moderate antiplasmodial activity (Dd2 IC50=6.25 μM) and low in vitro cytotoxicity against a mammalian cell line (CHO, IC50=119 μM). Compounds 2 and 10 also showed some promising chemosensitizing abilities (RMI=0.36 and 0.35 respectively). A direct correlation was found between the VGCC blocking ability of these polycyclic amines and their capacity to act as CQ resistance modulating agents.

  14. Steady-state inhibition model for the biodegradation of sulfonated amines in a packed bed reactor.

    Science.gov (United States)

    Juárez-Ramírez, Cleotilde; Galíndez-Mayer, Juvencio; Ruiz-Ordaz, Nora; Ramos-Monroy, Oswaldo; Santoyo-Tepole, Fortunata; Poggi-Varaldo, Héctor

    2015-05-25

    Aromatic amines are important industrial products having in their molecular structure one or more aromatic rings. These are used as precursors for the synthesis of dyes, adhesives, pesticides, rubber, fertilizers and surfactants. The aromatic amines are common constituents of industrial effluents, generated mostly by the degradation of azo dyes. Several of them are a threat to human health because they can by toxic, allergenic, mutagenic or carcinogenic. The most common are benzenesulfonic amines, such as 4-ABS (4-aminobenzene sulfonic acid) and naphthalene sulfonic amines, such as 4-ANS (4-amino naphthalene sulfonic acid). Sometimes, the mixtures of toxic compounds are more toxic or inhibitory than the individual compounds, even for microorganisms capable of degrading them. Therefore, the aim of this study was to evaluate the degradation of the mixture 4-ANS plus 4-ABS by a bacterial community immobilized in fragments of volcanic stone, using a packed bed continuous reactor. In this reactor, the amines loading rates were varied from 5.5 up to 69 mg L(-1) h(-1). The removal of the amines was determined by high-performance liquid chromatography and chemical oxygen demand. With this information, we have studied the substrate inhibition of the removal rate of the aromatic amines during the degradation of the mixture of sulfonated aromatic amines by the immobilized microorganisms. Experimental results were fitted to parabolic, hyperbolic and linear inhibition models. The model that best characterizes the inhibition of the specific degradation rate in the biofilm reactor was a parabolic model with values of RXM=58.15±7.95 mg (10(9) cells h)(-1), Ks=0.73±0.31 mg L(-1), Sm=89.14±5.43 mg L(-1) and the exponent m=5. From the microbial community obtained, six cultivable bacterial strains were isolated and identified by sequencing their 16S rDNA genes. The strains belong to the genera Variovorax, Pseudomonas, Bacillus, Arthrobacter, Nocardioides and Microbacterium. This

  15. Quantitative analysis of surface amine groups on plasma-polymerized ethylenediamine films using UV-visible spectroscopy compared to chemical derivatization with FT-IR spectroscopy, XPS and TOF-SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinmo [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Jung, Donggeun [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Park, Yongsup [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Kim, Yongki [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Moon, Dae Won [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Lee, Tae Geol [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of)]. E-mail: tglee@kriss.re.kr

    2007-02-28

    A quantitative analysis of the surface density of amine groups on a plasma-polymerized ethylenediamine thin film deposited on a platinum surface using inductively coupled plasma chemical vapor deposition method is described. UV-visible spectroscopy together with a chemical derivatization technique using Fourier transform infrared (FT-IR) spectroscopy was used to obtain the quantitative information. Chemical tags of pentafluorobenzaldehyde were hybridized with the surface amine groups and were easily detected due to the characteristic absorption bands of C-F stretching, aromatic ring and C=N stretching vibrations in the reflection-absorption FT-IR spectra. The surface amine density was reproducibly controlled as a function of deposition plasma power and quantified using UV-visible spectroscopy. A good linear correlation was observed between the FT-IR intensities of the characteristic absorption bands and the surface amine densities, suggesting the possibility of using this chemical derivatization technique to quantify the surface densities of specific functional groups on an organic surface. Chemical derivatization was also used with X-ray photoelectron spectroscopy on the same samples, and the results were compared with those obtained from FT-IR and time-of-flight secondary ion mass spectrometry. Although each analysis technique has different probing depths from the surface, the three different data sets obtained from the chemical tags correlated well with each other since each analysis technique measured the chemical tags on the sample surface.

  16. Interaction of protonated merocyanine dyes with amines in organic solvents

    Science.gov (United States)

    Ribeiro, Eduardo Alberton; Sidooski, Thiago; Nandi, Leandro Guarezi; Machado, Vanderlei Gageiro

    2011-10-01

    2,6-Diphenyl-4-(2,4,6-triphenylpyridinium-1-yl)phenolate ( 1a) and 4-[(1-methyl-4(1 H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one ( 2a) were protonated in organic solvents (dichloromethane, acetonitrile, and DMSO) to form 1b and 2b, respectively. The appearance of the solvatochromic bands of 1a and 2a was studied UV-vis spectrophotometrically by deprotonation of 1b and 2b in solution in the presence of the following amines: aniline (AN), N-methylaniline (NMAN), N, N-dimethylaniline (NDAN), n-butylamine (BA), diethylamine (DEA), and triethylamine (TEA). Titrations of 1b and 2b with the amines were carried out and the binding constants were determined from the titration curves in each solvent, using a mathematical model adapted from the literature which considers the simultaneous participation of two dye: amine stoichiometries, 1:1 and 1:2. The data obtained showed the following base order for the two compounds in DMSO: BA > DEA > TEA, while aromatic amines did not cause any effect. In dichloromethane, the following base order for 1b was verified: TEA > DEA > BA ≫NDAN, while for 2b the order was: TEA > DEA > BA, suggesting that 1b is more acidic than 2b. The data in acetonitrile indicated for 1b and 2b the following order for the amines: DEA > TEA > BA. The diversity of the experimental data were explained based on a model that considers the level of interaction of the protonated dyes with the amines to be dependent on three aspects: (a) the basicity of the amine, which varies according to their molecular structure and the solvent in which it is dissolved, (b) the molecular structure of the dye, and (c) the solvent used to study the system.

  17. Solid-phase Microextraction with Benzoxy-calix[6]arene Fiber Coupled to Gas Chromatography for the Analysis of Polycyclic Aromatic Hydrocarbons in Water

    Institute of Scientific and Technical Information of China (English)

    YE Chang-wen; ZHANG Xue-na; HUANG Jiang-yan; LI Xiu-juan; PAN Si-yi

    2011-01-01

    Headspace solid-phase microextraction(HS-SPME) with sol-gel calix[6]arene-containing fiber followed by gas chromatography with a flame ionization detector was used to examine the composition and distribution of seven polycyclic aromatic hydrocarbons(PAHs) in water. The novel SPME fiber exhibited higher extraction efficien cy to PAHs compared with poly(dimethylsiloxane) and other calixarene-containing fibers. Extraction/retention me chanism based on the interactions between calixarenes and PAHs was discussed. Owing to the good selectivity and high extraction capability of this calixarene fiber, low detection limits were obtained in a range of 0.34—6.50 ng/L and the relative standard deviation values were ≤ 12.3% for all of the analytes. The linear ranges of the proposed method were five orders of magnitude for the tested compounds, with linear correlation coefficients(r) greater than 0.998. The method was applied to the determination of polycyclic aromatic hydrocarbons in nine water sources in Wuhan City, China. Standard addition method was selected for the quantification and the recovery values were in a satisfactory range. Total PAHs concentrations in the nine surface water samples were found to vary between unde tectable and 8.840 μg/L with two-and three-ring PAHs predominating.

  18. The Efficacy of Oxidative Coupling for Promoting In-Situ Immobilization of Hydroxylated Aromatics in Contaminated Soil and Sediments Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Weber Jr., W. J.

    2000-10-01

    The study clearly shows that the structure and composition of the organic matter of soils and sediments are essential considerations for the selection of materials for engineered applications of oxidative coupling processes. A rate model was developed to facilitate quantitative evaluation and mechanistic interpretation of these fairly complex coupling processes.

  19. Fibrous nano-silica (KCC-1)-supported palladium catalyst: Suzuki coupling reactions under sustainable conditions

    KAUST Repository

    Fihri, Aziz

    2011-11-15

    Noble amines recycled: Fibrous high-surface-area nano-silica functionalized with aminopropyl groups and loaded with well-dispersed Pd nanoparticles is evaluated for the Suzuki coupling of aromatic halides. It is active for the reaction of a range of aryl bromides and iodides as well as chlorides with aryl boronic acids in good to excellent yields. The catalyst can be recovered and reused for a number of cycles with negligible loss in activity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Thermodynamics of organic 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 [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Fuente, Isaias Garcia de la [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

    2006-02-01

    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{sup E}), molar excess enthalpies (H{sup E}), molar excess heat capacities at constant pressure (C{sub P}{sup E}) and the concentration-concentration structure factor (S{sub CC}(0)). It is remarkable that DISQUAC correctly predicts the W-shaped curve of the C{sub P}{sup 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{sup E}(pyridine)>H{sup E}(methylpyridine)

  1. Magnetic microsphere-confined graphene for the extraction of polycyclic aromatic hydrocarbons from environmental water samples coupled with high performance liquid chromatography-fluorescence analysis.

    Science.gov (United States)

    Wang, Weina; Ma, Ruiyang; Wu, Qiuhua; Wang, Chun; Wang, Zhi

    2013-06-07

    In this paper, a magnetic microsphere-confined graphene adsorbent (Fe3O4@SiO2-G) was fabricated and used for the extraction of five polycyclic aromatic hydrocarbons (fluorene, anthracene, phenanthrene, fluoranthene and pyrene) from environmental water samples prior to high performance liquid chromatography with fluorescence detection. The Fe3O4@SiO2-G was characterized by various instrumental methods. Various experimental parameters that could affect the extraction efficiencies, such as the amount of Fe3O4@SiO2-G, the pH and ionic strength of sample solution, the extraction time and the desorption conditions, were investigated. Due to the high surface area and excellent adsorption capacity of the Fe3O4@SiO2-G, satisfactory extraction can be achieved with only 15mg of the adsorbent per 250mL solution and 5min extraction. Under the optimum conditions, a linear response was observed in the concentration range of 5-1500ngL(-1) for fluorene, 2.5-1500ngL(-1) for anthracene and 15-1500ngL(-1) for phenanthrene, fluoranthene and pyrene, with the correlation coefficients (r) ranging from 0.9897 to 0.9961. The limits of detection (S/N=3) of the method were between 0.5 and 5.0ngL(-1). The relative standard deviations (RSDs) were less than 5.6%. The recoveries of the method were in the range between 83.2% and 108.2%. The results indicated that this graphene-based magnetic nanocomposite had a great adsorptive ability toward the five polycyclic aromatic hydrocarbons from environmental water samples.

  2. Rodent repellent studies. IV. Preparation and properties of trinitrobenzene-aryl amine complexes

    Science.gov (United States)

    DeWitt, J.B.; Bellack, E.; Welch, J.F.

    1953-01-01

    Data are presented on methods of preparation, chemical arid physical characteristics, toxicity, and repellency to rodents of complexes of symmetrical trinitrohenzene with various aromatic amines: When applied in suitable carriers or incorporated in plastic .films, members of this series ofmaterials were shown to offer significant increases in time required by wild rodents to damage common packaging materials.

  3. Protecting-group-free amination of halogenated nitrobenzaldehyde with palladium catalyst

    Institute of Scientific and Technical Information of China (English)

    Jing Cao; Jun Xiang Feng; Yong Xiang Wu; Ya Ya Tuo

    2010-01-01

    One-step method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide (HMPT) media without the protection of aldehyde groups.

  4. Tris{4-[(1,3-diphenyl-1H-pyrazol-4-ylmethylene]-41-aminobiphenyl}amine

    Directory of Open Access Journals (Sweden)

    Sandhya P. Veettil

    2010-04-01

    Full Text Available Tris{4-[(1,3-diphenyl-1H-pyrazol-4-ylmethylene]-41-aminobiphenyl}amine was synthesized from N-(4-bromophenyl-N-[(1,3-diphenyl-1H-pyrazol-4-ylmethylene]amine and tris(4-bromophenylamine based on Ullmann coupling reaction. The synthesized compound was characterized by NMR, IR, MS and elemental analysis.

  5. Exploiting Solvate Ionic Liquids for Amine Gas Analysis on a Quartz Crystal Microbalance.

    Science.gov (United States)

    Li, Hsin-Yi; Chu, Yen-Ho

    2017-05-16

    We demonstrated in this work the usefulness of solvate ionic liquids SIL 3 and SIL 4 for chemoselective detection of amine gases on a quartz crystal microbalance. This detection of gaseous amines was achieved by nucleophilic aromatic addition reactions with super electrophilic SIL 3 or SIL 4 thin-coated on quartz chips. Starting with inexpensive reagents, functional SIL 3 and SIL 4 could be readily synthesized in two short steps with high isolated yield (81 and 77%, respectively). The QCM platform developed in this work is readily applicable and highly sensitive to low molecular weight amine gases: for propylamine gas at 10 Hz decrease in resonance frequency, the sensitivity of detection using SIL 4 was 5.4 ppb. This simple and convenient assembly of neutral ligands (e.g., 1a and 1b) with Li(+) ion to afford room temperature ionic liquids should be of great importance for a myriad of applications. To the best of our knowledge, no example to date of reports based on nucleophilic aromatic addition reactions demonstrating sensitive amine gas detection in solvate ionic liquids on a QCM has been reported. Furthermore, because of the high color intensity of the Meisenheimer complexes formed, our preliminary result showed that SIL 4 loaded on copier paper can be used not only as a portable amine gas sensor but also as a potential invisible ink that is only revealed by amine vapor.

  6. A General, Simple Catalyst for Enantiospecific Cross Couplings of Benzylic Ammonium Triflates and Boronic Acids: No Phosphine Ligand Required

    Science.gov (United States)

    Basch, Corey H.; Song, Ye-Geun; Watson, Mary P.

    2014-01-01

    Highly improved conditions for the enantiospecific cross coupling of benzylic ammonium triflates with boronic acids are reported. This method relies on the use of Ni(cod)2 without ancillary phosphine or N-heterocyclic carbene ligands as catalyst. These conditions enable the coupling of new classes of boronic acids and benzylic ammonium triflates. In particular, both heteroaromatic and vinyl boronic acids are well tolerated as coupling partners. In addition, these conditions enable the use of ammonium triflates with a variety of substituents at the benzylic stereocenter. Further, naphthyl-substitution is not required on the benzylic ammonium triflate; ammonium triflates with simple aromatic substituents also undergo this coupling. Good to high yields and levels of stereochemical fidelity are observed. This new catalyst system greatly expands the utility of enantiospecific cross couplings of these amine-derived substrates for the preparation of highly enantioenriched products. PMID:25364060

  7. Determination of carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem mass spectrometry%超高效液相色谱-串联质谱法快速测定纺织品和皮革中偶氮染料释放的致癌芳香胺

    Institute of Scientific and Technical Information of China (English)

    温裕云; 欧延; 何明超; 弓振斌

    2013-01-01

    建立了超高效液相色谱-串联质谱法(UHPLC-MS/MS)快速测定纺织品和皮革中偶氮染料释放的致癌芳香胺物质的方法.样品前处理采用BS EN 14362-1:2012(纺织品)和ISO 17234-1:2010(皮革)方法,然后采用甲醇定容,再用Eclipse XDB-C18 RRHD色谱柱进行梯度洗脱分离,流动相为甲醇和水;采用电喷雾正离子模式,并用多反应监测模式(MRM)测定,外标法定量.方法优化了色谱分离条件、质谱碎裂电压、碰撞能量等,并考察了不同样品基质对回收率的影响.方法的定量限小于0.2 mg/kg;不同基质不同浓度的加标回收率在70% ~ 120%之间(添加水平为500、1 000、1 500 μg/L,n=7);相对标准偏差小于15%.该方法的灵敏度远小于欧盟与我国国家标准要求的30 mg/kg,完全满足其定性定量的检测要求,并且检测速度快,选择性好.%A rapid determination method was developed for the quantification and confirmation of 22 carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem electrospray ionization mass spectrometry (UHPLC-MS/MS). The methods of EN 14362-1:2012 (for textiles) and ISO 17234-1 :2010 (for leather) were adopted for sample pretreatment, finally diluted with methanol. The target compounds were separated by an Eclipse XDB-C18 RRHD column and eluted with methanol and water in gradient, and then determined by positive electrospray ionization mass spectrometry under multiple reaction monitoring (MRM) mode. The external standard method was used for the quantitative analysis. The separation conditions, fragment voltages, collision energies, etc. were optimized. The limits of quantification (LOQ) were below 0. 2 mg/kg for different compounds , matrix spike recoveries ranged from 70% to 120% at the spiked levels of 500, 1 000 and 1 500 μg/L, and the relative standard deviations (RSDs) were less than 15%. The proposed method is rapid

  8. 超高效液相色谱-电喷雾串联质谱法同时测定鱼类加工品中12种杂环胺类化合物%Simultaneous determination of 12 heterocyclic aromatic amines in fish processing products by UPLC/ESI-MS/MS

    Institute of Scientific and Technical Information of China (English)

    徐琦; 杨洪生; 吴光红; 张美琴

    2012-01-01

    建立了超高效液相色谱-电喷雾串联质谱法同时测定鱼类加工品中12种杂环胺类化合物(HAAs)的分析方法.经过条件优化,肉样选用乙酸乙酯、氨水和三乙胺提取,提取液经MCX固相萃取小柱净化,按V(甲醇):V(氨水)=9∶1洗脱,采用Thermo Hypersil Gold C18色谱柱,以甲醇和5 mmol·L-1乙酸铵溶液为流动相进行梯度洗脱分离,电喷雾离子源(ESI),正离子模式,采用选择反应监测(SRM)扫描模式,内标法进行定量分析.结果表明,12种HAAs在1.0~100.0μg·L-1范围内线性关系良好,相关系数R >0.99,在12 min内实现分离,3个加标水平的平均回收率为42.98% ~125.00% (n =6),相对标准偏差(RSD)为1.49% ~9.88%,检测限(LOD)为0.3~ 1.0 μg·kg-1.该方法简便快捷,准确度高,易推广应用,可作为快速测定鱼类加工品中多种HAAs的有效方法.%We established a method for simultaneous determination of 12 heterocyclie aromatic amines ( HAAs) in fish processing products using ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS). After optimizing the conditions, taking ethyl acetate, ammonia and triethylamine as extraction solutions, we purified the extract with MCX SPE column, and eluted by V( methanol) : V( ammonia) =9:1. Based on a Thermo Hypersil Gold C18 column, we performed a gradient elution separation by methanol and a gradient elution with the mobile phase of 5 mmol·L-1 ammonium acetate. Electrospray i-onization source was applied and operated in positive ion mode, using selected reaction monitoring ( SRM) scan mode and internal standard method for quantitative analysis. The results reveal that 12 HAAs show a good linear relationship within 1.0~100. 0 μg·L-1 (R >0. 99). The separation was finished within 12 min. The average recovery (n = 6) of the 12 HAAs spiked in tested samples at 3 levels ranged from 42. 98% to 125. 00% with the relative standard deviation ( RSD

  9. 液相色谱-离子阱-飞行时间串联质谱同时检测肉制品中14种杂环胺%Determination of 14 Heterocyclic Aromatic Amines in Meat Products by Liquid Chromatography - Ion Trap - Time of Flight Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王敏; 郭德华; 丁卓平; 姚劲挺

    2011-01-01

    建立了液相色谱-离子阱-飞行时间串联质谱(LCMS - IT - TOF)同时测定肉制品中14种杂环胺( HAAs)残留量的分析方法.样品以乙腈提取,经Phenomenex strata-X-C小柱净化,甲醇-氨水(9:1)洗脱,氮吹至干,经1 mL乙腈-水(1:9)定容离心后上机测定,基质曲线内标法定量.结果表明,14种杂环胺在5 ~ 250 μg/L质量浓度范围内线性良好,相关系数均不低于0.994 0,检出限(S/N=3)为0.59 ~ 3.27 μg/kg.14种杂环胺在加标水平为10、50、250 μg/kg时的回收率分别为69% ~ 107%、67% ~ 106%、76% ~ 113%,相对标准偏差(RSD,n=6)分别为1.5%~15.6%、1.3%~11.8%、 1.8%~9.7%.结果显示该方法线性范围宽,精密度和准确度较高,分析时间短,净化效果好,可满足肉制品中多种杂环胺残留同时检测的要求.%A rapid analytical method was developed for the determination of 14 heterocyclic aromatic amines ( HAAs) in meat products by liquid chromatography - ion trap - time of flight tandem mass spectrometry ( LCMS - IT - TOF). The samples were extracted with acetonitrile. The extract was cleaned up with Phenomenex strata-X-C, eluted with methanol - ammonia (9 : 1 ) , then evaporated with a stream of nitrogen to near dryness and redissoved with acetonitrile - water ( 1:9). The separation of HAAs was performed on a Phenomenex Kinetex 2. 6|x C,8 100A (2. 1 mm I. D. X 100 mm, 2. 6 |xm) , using 30 mmol/L ammonium formate - acetonitrile as mobile phase by gradient elution. The analytes were detected under positive-ion electrospray ionization mode. Results showed that the linear ranges of 14 HAAs were 5 -250 |Xg/L with limits of detection (S/N = 3 ) of 0. 59 - 3. 27 |xg/ kg. The mean recoveries of all the compounds at three spiked levels of 10, 50, 250 |xg/kg were in the range of 69% -107%, 67% -106% and 76% -113%, respectively, with the corresponding RSDs(n = 6) of 1.5% -15.6%, 1.3% -11.8% and 1. 8% -9.7%, respectively. The established

  10. Continuous-Flow Electrophilic Amination of Arenes and Schmidt Reaction of Carboxylic Acids Utilizing the Superacidic Trimethylsilyl Azide/Triflic Acid Reagent System.

    Science.gov (United States)

    Chen, Yuesu; Gutmann, Bernhard; Kappe, C Oliver

    2016-10-07

    A continuous flow protocol for the direct stoichiometric electrophilic amination of aromatic hydrocarbons and the Schmidt reaction of aromatic carboxylic acids using the superacidic trimethylsilyl azide/triflic acid system is described. Optimization of reagent stoichiometry, solvent, reaction time, and temperature led to an intensified protocol at elevated temperatures that allows the direct amination of arenes to be completed within 3 min at 90 °C. In order to improve the selectivity and scope of this direct amination protocol, aromatic carboxylic acids were additionally chosen as substrates. Selected carboxylic acids could be converted to their corresponding amine counterparts in good to excellent yields (11 examples, 55-83%) via a Schmidt reaction employing similar flow reaction conditions (acid intermediate, the corrosive nature of triflic acid, and the exothermic quenching were addressed by designing a suitable continuous flow reaction setup for both types of transformations.

  11. Rett syndrome - Stimulation of endogenous biogenic amines

    Science.gov (United States)

    Pelligra, R.; Norton, R. D.; Wilkinson, R.; Leon, H. A.; Matson, W. R.

    1992-01-01

    Transient hypercapnic hyperoxemia was induced in two Rett syndrome children by the administration of a gaseous mixture of 80 percent O2 and 20 percent CO2. Time course studies of neurotransmitters and their metabolites showed an immediate and marked increase in central biogenic amine turnover following inhalation of the gas mixture. The increased turnover of biogenic amines was associated with improved clinical changes. This suggests a coupled relationship and provides further support for an etiological role of neurotransmitter dysfunction in Rett syndrome. In a complementary study, elevation of pulmonary CO2 by application of a simple rebreathing device resulted in improvement of abnormal blood gases and elimination of the Cheyne-Stokes-like respiratory pattern of the Rett syndrome. Near normalization of the EEG occurred when a normal respiratory pattern was imposed by means of a respirator. Taken together, these results lead to the preliminary conclusion that cerebral hypoxemia secondary to abnormal respiratory function may contribute to diminished production of biogenic amines in Rett syndrome.

  12. Rh(III)-Catalyzed C-H Bond Addition/Amine-Mediated Cyclization of Bis-Michael Acceptors.

    Science.gov (United States)

    Potter, Tyler J; Ellman, Jonathan A

    2016-08-01

    A Rh(III)-catalyzed C-H bond addition/primary amine-promoted cyclization of bis-Michael acceptors is reported. The C-H bond addition step occurs with high chemoselectivity, and the subsequent intramolecular Michael addition, mediated by a primary amine catalyst, sets three contiguous stereocenters with high diastereoselectivity. A broad range of directing groups and both aromatic and alkenyl C-H bonds were shown to be effective in this transformation, affording functionalized piperidines, tetrahydropyrans, and cyclohexanes.

  13. Vanadium-catalyzed oxidative Strecker reaction: α-C-H cyanation of para-methoxyphenyl (PMP)-protected primary amines.

    Science.gov (United States)

    Zhu, Chen; Xia, Ji-Bao; Chen, Chuo

    2014-01-01

    We describe an oxidative Strecker reaction that allows for direct cyanation of para-methoxyphenyl (PMP)-protected primary amines. A vanadium(V) complex was used as the catalyst and TBHP as the oxidant. The cyanation occurs at the α-C position bearing either an alkyl or an aromatic group. This method provides a direct access to α-aminonitrile from amines with one-carbon extension.

  14. Macrocyclic polyamine-functionalized silica as a solid-phase extraction material coupled with ionic liquid dispersive liquid-liquid extraction for the enrichment of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Liu, Longhui; He, Lijun; Jiang, Xiuming; Zhao, Wenjie; Xiang, Guoqiang; Anderson, Jared L

    2014-04-01

    In this study, silica modified with a 30-membered macrocyclic polyamine was synthesized and first used as an adsorbent material in SPE. The SPE was further combined with ionic liquid (IL) dispersive liquid-liquid microextraction (DLLME). Five polycyclic aromatic hydrocarbons were employed as model analytes to evaluate the extraction procedure and were determined by HPLC combined with UV/Vis detection. Acetone was used as the elution solvent in SPE as well as the dispersive solvent in DLLME. The enrichment of analytes was achieved using the 1,3-dibutylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL/acetone/water system. Experimental conditions for the overall macrocycle-SPE-IL-DLLME method, such as the amount of adsorbent, sample solution volume, sample solution pH, type of elution solvent as well as addition of salt, were studied and optimized. The developed method could be successfully applied to the analysis of four real water samples. The macrocyclic polyamine offered higher extraction efficiency for analytes compared with commercially available C18 cartridge, and the developed method provided higher enrichment factors (2768-5409) for model analytes compared with the single DLLME. Good linearity with the correlation coefficients ranging from 0.9983 to 0.9999 and LODs as low as 0.002 μg/L were obtained in the proposed method.

  15. Evaluation of the contamination of spirits by polycyclic aromatic hydrocarbons using ultrasound-assisted emulsification microextraction coupled to gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel

    2016-01-01

    The concentration of twelve polycyclic aromatic hydrocarbons (PAHs), included in the list of priority pollutants, in different spirits has been obtained by means of a rapid and sensitive method based on gas chromatography and mass spectrometry (GC-MS). The environmentally friendly ultrasound-assisted emulsification microextraction (USAEME) technique allowed the easy and effective preconcentration of the PAHs from the sample matrices. Several parameters affecting the extraction efficiency, such as the nature and volume of the extractant solvent, and the addition of salt, as well as the sonication parameters were investigated and optimized. The absence of matrix effects under the optimized conditions allowed the sample quantification against aqueous standards. Detection limits ranged between 1.8 and 6.3 ng L(-1), depending on the compound. Different spirit samples were successfully analyzed using the proposed method, and contents of up to 0.9 μg L(-1) were found. Relative recoveries at fortified levels of 0.2 and 1 μg L(-1) were in the range 84-118%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Aliphatic amine responsive organogel system based on a simple naphthalimide derivative.

    Science.gov (United States)

    Cao, Xinhua; Zhang, Tingting; Gao, Aiping; Li, Keli; Cheng, Qiuli; Song, Lijuan; Zhang, Min

    2014-09-07

    A new gelator 1 based on a simple naphthalimide derivative was synthesized and fully characterized. It was found that the organogel 1 was formed only in a mixed solvent of methanol and H2O (1/1, v/v). The organogel was thoroughly characterized by using various microscopic techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and UV-vis, fluorescence and Fourier transform infrared (FTIR) spectroscopy. Hydrogen bonds were the main driving force for the organogel formation. Interestingly, the organogel 1 exhibited the ability to distinguish aliphatic amines from aromatic amines. The gel state and fluorescence emission intensity were both changed after two minutes after the addition of aliphatic amines. This organogel system could be applied in the detection of aliphatic amine pollutants.

  17. Synthesis and properties of novel soluble poly(aryl amine ketone)s as high-performance polymers

    Institute of Scientific and Technical Information of China (English)

    CHANG GuanJun; TANG ShiZhen; LUO Xuan; WANG Qiang; XU Zhe; ZHANG Lin; LIN RunXiong

    2008-01-01

    A series of poly(aryl amine ketone)s have been obtained by the condensation polymerization of differ-ent aromatic dibromides with different primary aromatic diamines via palladium-catalyzed aryl amina-tion reaction. The structures of polymers are characterized by means of FT-IR, 1H NMR spectroscopy, and elemental analysis. The results show an agreement with the proposed structures. DSC and TG measurements show that polymers possess high glass transition temperature (Tg>170"C) and good thermal stability with high decomposition temperatures (To>450℃). These novel polymers also exhibit good mechanical behaviors and good solubility.

  18. Simultaneous determination of 24 polycyclic aromatic hydrocarbons in edible oil by tandem solid-phase extraction and gas chromatography coupled/tandem mass spectrometry.

    Science.gov (United States)

    Xu, Ting; Tang, Hua; Chen, Dazhou; Dong, Haifeng; Li, Lei

    2015-01-01

    An efficient and fast tandem SPE method followed by GC/MS/MS has been developed for the determination and the quantification of 24 polycyclic aromatic hydrocarbons (PAHs) in edible oil. This method includes the monitoring of 15 + 1 PAHs designated as a priority by the European Union in their 2005/108/EC recommendation and 16 PAHs listed by the U. S. Environmental Protection Agency. The sample preparation procedures were based on SPE in which PAH-dedicated cartridges with molecularly imprinted polymers and graphitized carbon black were used in series. The novel tandem SPE combination of selective extraction and purification of light and heavy PAHs provided highly purified analytes. Identification and quantification of 24 target PAHs were performed using GC/MS/MS with the isotope dilution approaches using D-labeled and (13)C-labeled PAHs. The advantages of GC/MS/MS as compared to other detection methods include high sensitivity, selectivity, and interpretation ability. The method showed satisfactory linearity (R(2) > 0.998) over the range assayed (0.5-200 μg/kg); the LODs ranged from 0.03 to 0.6 μg/kg, and LOQs from 0.1 to 2.0 μg/kg. The recoveries using this method at three spiked concentration levels (2, 10, and 50 μg/kg) ranged from 56.8 to 117.7%. The RSD was lower than 12.7% in all cases. The proposed analytical method has been successfully applied for the analysis of the 24 PAHs in edible oil.

  19. Concerning the Potential Reversibility of Carbometalation in Alkoxide-directed Ti(Oi-Pr)4-mediated Reductive Cross-Coupling of Homoallylic Alcohols with Aromatic Imines

    Science.gov (United States)

    Takahashi, Masayuki; Micalizio, Glenn C.

    2011-01-01

    In an attempt to understand the nature of selectivity in Ti-mediated reductive cross-coupling between homoallylic alcohols and imines, we investigated whether thermodynamic equilibration of the presumed organometallic intermediate plays a role in selectivity. No evidence could be found for olefin exchange in preformed azatitanacyclopentanes – an observation that is consistent with a model based on kinetically controlled selective carbometalation. PMID:20379585

  20. Relationship between Structures and Carcinogenicities of Heterocyclic Amines

    Institute of Scientific and Technical Information of China (English)

    JU Xue-hai; DAI Qian-huan; CHEN Sha; WANG Wen-jun

    2004-01-01

    Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on the metabolism of HCAs and the Di-region theory. The degree of easiness for the formation of Di-region electrophilic centers determines the carcinogenic activity. There is a good linear relationship between the observed carcinogenicities and the PM3 calculated parameters, with r=0.973 and F=29.8>(F*0.*01).

  1. Dispersive liquid-liquid microextraction coupled with dispersive micro-solid-phase extraction for the fast determination of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Shi, Zhi-Guo; Lee, Hian Kee

    2010-02-15

    A new two-step microextraction technique, combining dispersive liquid-liquid microextraction (DLLME) and dispersive microsolid-phase extraction (D-micro-SPE), was developed for the fast gas chromatographic-mass spectrometric determination of polycyclic aromatic hydrocarbons (PAHs) in environmental samples. A feature of the new procedure lies in that any organic solvent immiscible with water can be used as extractant in DLLME. A special apparatus, such as conical-bottom test tubes, and tedious procedures of centrifugation, refrigeration of the solvent, and then thawing it, associated with classical DLLME or similar techniques are not necessary in the new procedure, which potentially lends itself to possible automation. In the present D-micro-SPE approach, hydrophobic magnetic nanoparticles were used to retrieve the extractant of 1-octanol in the DLLME step. It is noteworthy that the target of D-micro-SPE was the 1-octanol rather than the PAHs. Because of the rapid mass transfer associated with the DLLME and the D-micro-SPE steps, fast extraction could be achieved. Parameters affecting the extraction efficiency were investigated in detail. The optimal conditions were as follows: vortex at 3200 rpm in the DLLME step for 2 min and in D-micro-SPE for 1 min and then desorption by sonication for 4 min with acetonitrile as the solvent. The results demonstrated that enrichment factors ranging from 110- to 186-fold were obtained for the analytes. The limits of detection and the limits of quantification were in the range of 11.7-61.4 pg/mL and 0.04-0.21 ng/mL, respectively. The linearities were 0.5-50, 1-50, or 2-50 ng/mL for different PAHs. Finally, the two-step extraction method was successfully used for the fast determination of PAHs in river water samples. This two-step method, combining two different and efficient miniaturized techniques, provides a fast means of sample pretreatment for environmental water samples.

  2. Geometry dependence of electron donating or accepting abilities of amine groups in 4,4‧-disulfanediylbis(methylene)dithiazol-2-amine: Pyramidal versus planar

    Science.gov (United States)

    Karabıyık, Hasan; Kırılmış, Cumhur; Karabıyık, Hande

    2017-08-01

    The molecular and crystal structure of the title compound in which two thiazole-2-amine rings are linked to each other by disulfide bridge (sbnd Csbnd Ssbnd Ssbnd Csbnd) were studied by single-crystal X-ray diffraction, FT-IR, NMR spectroscopy, quantum chemical calculations and topological analyses on the electron density. A novel synthesis route for the compounds having symmetrical disulfide bridge is reported. The most important result regarding the compound is about electron donating or accepting properties of the terminal amine groups. Planar amine group acts as an electron-donating group, while pyramidal amine behaves as electron-accepting group. This inference was confirmed by scrutiny of crystallographic geometry and quantum chemical studies. To ascertain underlying reasons for this fact, intermolecular interactions (Nsbnd H⋯N type H-bonds and Csbnd H···π interactions) were studied. These interactions involving aromatic thiazole rings are verified by topological electron density and Hirshfeld surface analyses. Intermolecular interactions do not have an effect on the differentiation in electron donating or accepting ability of amine groups, because both amine groups are involved in Nsbnd H⋯N type H-bonds. In methodological sense, it has been understood that Ehrenfest forces acting on electron density are useful theoretical probe to analyze intra-molecular charge transfer processes.

  3. Metabolic Effects of Dietary Proteins, Amino Acids and The Other Amine Consisting Compounds on Cardiovascular System.

    Directory of Open Access Journals (Sweden)

    Elif Uğur

    2017-01-01

    Full Text Available During the prevention and treatment of cardiovascular diseases, first cause of deaths in the world, diet has a vital role. While nutrition programs for the cardiovascular health generally focus on lipids and carbohydrates, effects of proteins are not well concerned. Thus this review is written in order to examine effect of proteins, amino acids, and the other amine consisting compounds on cardiovascular system. Because of that animal or plant derived proteins have different protein composition in different foods such as dairy products, egg, meat, chicken, fish, pulse and grains, their effects on blood pressure and regulation of lipid profile are unlike. In parallel amino acids made up proteins have different effect on cardiovascular system. From this point, sulfur containing amino acids, branched chain amino acids, aromatic amino acids, arginine, ornithine, citrulline, glycine, and glutamine may affect cardiovascular system in different metabolic pathways. In this context, one carbon metabolism, synthesis of hormone, stimulation of signaling pathways and effects of intermediate and final products that formed as a result of amino acids metabolism is determined. Despite the protein and amino acids, some other amine consisting compounds in diet include trimethylamine N-oxide, heterocyclic aromatic amines, polycyclic aromatic hydrocarbons and products of Maillard reaction. These amine consisting compounds generally increase the risk for cardiovascular diseases by stimulating oxidative stress, inflammation, and formation of atherosclerotic plaque.

  4. Synthesis of Boron-Containing Primary Amines

    Directory of Open Access Journals (Sweden)

    Sheng-Hsuan Chung

    2013-10-01

    Full Text Available In this study, boron-containing primary amines were synthesized for use as building blocks in the study of peptoids. In the first step, Gabriel synthesis conditions were modified to enable the construction of seven different aminomethylphenyl boronate esters in good to excellent yields. These compounds were further utilized to build peptoid analogs via an Ugi four-component reaction (Ugi-4CR under microwave irradiation. The prepared Ugi-4CR boronate esters were then successfully converted to the corresponding boronic acids. Finally, the peptoid structures were successfully modified by cross-coupling to aryl/heteroaryl chlorides via a palladium-mediated Suzuki coupling reaction to yield the corresponding derivatives in moderate to good yields.

  5. Sorptive extraction using polydimethylsiloxane/metal-organic framework coated stir bars coupled with high performance liquid chromatography-fluorescence detection for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Hu, Cong; He, Man; Chen, Beibei; Zhong, Cheng; Hu, Bin

    2014-08-22

    In this work, metal-organic frameworks (MOFs, Al-MIL-53-NH₂) were synthesized via the hydrothermal method, and novel polydimethylsiloxane/metal-organic framework (PDMS/MOFs, PDMS/Al-MIL-53-NH₂)-coated stir bars were prepared by the sol-gel technique. The preparation reproducibility of the PDMS/MOFs-coated stir bar was good, with relative standard deviations (RSDs) ranging from 4.8% to 14.9% (n=7) within one batch and from 6.2% to 16.9% (n=6) among different batches. Based on this fact, a new method of PDMS/MOFs-coated stir bar sorptive extraction (SBSE) and ultrasonic-assisted liquid desorption (UALD) coupled with high performance liquid chromatography-fluorescence detection (HPLC-FLD) was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. To obtain the best extraction performance for PAHs, several parameters affecting SBSE, such as extraction time, stirring rate, and extraction temperature, were investigated. Under optimal experimental conditions, wide linear ranges and good RSDs (n=7) were obtained. With enrichment factors (EFs) of 16.1- to 88.9-fold (theoretical EF, 142-fold), the limits of detection (LODs, S/N=3) of the developed method for the target PAHs were found to be in the range of 0.05-2.94 ng/L. The developed method was successfully applied to the analysis of PAHs in Yangtze River and East Lake water samples.

  6. Samarium—promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    郑兴良; 张永敏; 等

    2002-01-01

    The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liq-uid medium to afford aromatic amines,Under these conditions the other substituents,such as -X,-CHO,-COOH,-CN,-NHTos and -alkyl,remained intact,the notable advan-tages of this reaction are its mild conditions ,simple operation,short reaction time,high yields and easy recycling of ionic liquid.

  7. Simultaneous determination of nine heterocyclic aromatic amines in mutton products by solid phase extraction-high performance liquid chromatography%固相萃取-高效液相色谱法同时测定羊肉制品中9种杂环胺

    Institute of Scientific and Technical Information of China (English)

    郭海涛; 潘晗; 王振宇; 陈丽; 张德权

    2012-01-01

    建立了同时测定羊肉制品中9种杂环胺的固相萃取-高效液相色谱(SPE-HPLC)分析方法.样品经2 mol/LNaOH超声提取、80 mL二氯甲烷液-液萃取,利用阳离子交换柱(MCX柱)净化和富集后进行HPLC分析.采用反相C18色谱柱,以乙腈和0.01 mol/L磷酸溶液(用三乙胺调整pH3.6)为流动相对杂环胺进行梯度洗脱,使用二极管阵列检测器(DAD)分别在228 nm(2-氨基-9H-吡啶并[2,3-b]吲哚(AaC)、2-氨基-3-甲基-9H-吡啶并[2,3-b]吲哚( MeAaC))、253 nm(2-氨基-3-甲基咪唑并[4,5-f]喹啉(IQ)、1-甲基-9H-吡啶并[3,4-b]吲哚(Harman)、2-9H-吡啶并[3,4-b]吲哚(Norharman))、263 nm(2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉(MeIQx)、2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉(4,8-DiMeIQx)、3-氨基-1-甲基-5H-吡啶并[4,3-b]吲哚(Trp-p-2))、321 nm(2-氨基-1-甲基-6-苯基咪唑并[4,5-b]吡啶(PhIP))处进行检测.实验结果表明,9种杂环胺分离效果良好,回收率为50.27%~94.77%(n=6),相对标准偏差为0.08% ~4.42%;通过全波长扫描,确定检出限(以信噪比(S/N)=3计)为1.6~41.0 μg/L.该方法操作简单,结果准确,重现性好,可用于同时检测羊肉制品中9种杂环胺的含量.%A method was established for the simultaneous determination of nine heterocyclic aromatic amines (HAAs) in mutton products by solid phase extraction-high performance liquid chromatography (SPE-HPLC). As a result, the sample was prepared by ultrasound in 2 mol/L NaOH, and dichloromethane was selected as the extraction solvent. The extract was purified and concentrated with an MCX SPE column. The chromatographic separation was achieved on a reverse-phase C18 column by gradient elution using 0. 01 mol/L phosphoric acid (adjusted to pH 3. 6 by triethylamine) and acetonitrile, detected with a diode array detector (DAD) at 228 nm for 2-amino-9H-pyrido[2,3-6]indole (AaC) and 2-amino-3-methyl-9H-pyrido[2,3-6]indole (MeAaC); 253 nm for 2-amino-3-methylimidazo[4

  8. 固相萃取-高效液相色谱法同时测定传统禽肉制品中的9种杂环胺类化合物%Simultaneous determination of 9 heterocyclic aromatic amines in poultry products by solid-phase extraction-high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    邵斌; 彭增起; 杨洪生; 吴光红; 姚瑶; 万可慧

    2011-01-01

    A method was developed for the simultaneous determination of 9 heterocyclic aromatic amines (HAAs) including 2-amino-3-methylimidazo[4,5-f] quinoline (IQ), 2-amino-3,4-dimethylimidazo[ 4,5-f] quinoline ( MeIQ), 2-amino-3 , 8-dimethylimidazo [ 4, 5-f] quinoxaline (MelQx), 2-amino-3, 4, 8-trimethyl-imidazo [4,5-f] quinoxaline (4, 8-DiMeIQx) , 2-amino-l-methyl-6-phenylimidazo[4,5-b)]pyridine (PhIP), 3-amino-l-methyl-5ff-pyrido [4, 3-6 ] indole (Trp-p-2), 3-amino-l,4-dimethyl-5H-pyrido[4,3-6] indole (Trp-p-1), 9H-pyrido[ 3 ,4-6] indole (Norharman), 1-methyl-9H-pyrido[3,4-b] indole (Harman)) in poultry products using solid-phase extraction-high performance liquid chromatography (SPE-HPLC). The performance of 3 different organic extraction solutions, 2 solid phase extraction (SPE) procedures, three different reversed-phase columns and five different mobile phases were tested for optimizing separation conditions of the 9 HAAs from poultry products. In the end, ethyl acetate was selected as the extraction solution, and the extract was purified with propylsulfonic acid silica ( PRS) and C,, SPE columns. The analysis was performed on a TSK-gel ODS-80TM column using a gradientelution with the mobile phases of 0. 05 mol/L aqueous acetic acid-ammonium acetate buffer (pH 3.4) and acetonitrile. The results showed that the average recoveries (n =6) of the 9 HAAs spiked in meat samples at 3 levels ranged from 60. 47% to 90. 55% with the relative standard deviations ( RSDs) between 0.49% and 9. 74%, and the limits of detection ( LODs, S/N = 3) were in the range of 0. 1 -3.6 μg/kg. The method is simple, rapid, accurate and sensitive enough for the analysis of HAAs in poultry products.%建立了固相萃取-高效液相色谱同时测定传统禽肉制品中9种杂环胺类化合物(HAAs)(包括2-氨基-3-甲基咪唑并[4,5-f]喹啉、2-氨基-3,4-二甲基咪唑并[4,5-f]喹啉、2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉、2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉、2

  9. Determination of 14 heterocyclic aromatic amines in wine by liquid chromatography-ion trap-time of flight tandem mass spectrometry%液相色谱-离子阱-飞行时间串联质谱同时检测葡萄酒中14种杂环胺

    Institute of Scientific and Technical Information of China (English)

    王敏; 郭德华; 丁卓平; 姚劲挺; 李锋格; 苏敏

    2012-01-01

    建立了液相色谱-离子阱-飞行时间串联质谱法(LC-IT-TOF MS)同时测定葡萄酒中14种杂环胺(HAAs)残留量的分析方法.样品于乙酸乙酯碱性条件下提取,内标法定量,Phenomenex Kinetex C18 100A色谱柱(100 mm×2.1 mm,2.6μm)分离,以乙腈和30 mmol/L甲酸铵为流动相进行梯度洗脱.实验结果表明,2-氨基-3,7,8-三甲基咪唑[4,5-f]喹喔啉在1~500 μg/L、2-氨基-3,8-二甲基咪唑[4,5-f]喹喔啉在10 ~ 500 μg/L、其他12种杂环胺在5 ~ 500μg/L质量浓度范围内线性良好,相关系数均不小于0.994 5,检出限(以信噪比为3计)0.33~1.77μg/L.14种杂环胺在加标水平为10、50、100 μg/L时的回收率分别为71.6%~96.4%、72.9% ~ 101.9%、74.5% ~103.3%,相对标准偏差(RSD,n=6)分别为2.9%~7.9%、1.7%~5.3%、1.8%~4.8%.结果显示该方法线性范围宽,精密度和准确度较高,分析时间短,净化效果好,可满足葡萄酒中多种杂环胺残留同时检测的要求.%A rapid qualitative and quantitative analytical method was developed for the simultaneous determination of 14 heterocyclic aromatic amines {HAAs) in wine by liquid chromatogra-phy-ion trap-time of flight tandem mass spectrometry (LC-1T-TOF MS). HAAs were extracted from the samples by ethyl acetate under alkaline condition. The quantitation was carried out using internal standard method. The separation of HAAs was carried out based on Phenomenex Kinetex C18 100A column (100 mm x2. 1 mm, 2. 6μm), with a gradient elution of acetonitrile and 30 mmol/L ammonium formate at a flow rate of 0. 4 mL/min. The analytes were detected under positive-ion electrospray ionization mode. The results showed that the linear ranges of the 14 HAAs were 1 - 500μg/L with limits of detection (signal/noise = 3) of 0. 33 - 1. 77μg/L. The average recoveries of all the compounds spiked in wine samples at three levels of 10, 50, 100 (j.g/L were in the ranges of 71. 6% -96.4%, 72.9% -101.9%, 74

  10. Atmospheric pressure solid analysis probe coupled to quadrupole-time of flight mass spectrometry as a tool for screening and semi-quantitative approach of polycyclic aromatic hydrocarbons, nitro-polycyclic aromatic hydrocarbons and oxo-polycyclic aromatic hydrocarbons in complex matrices.

    Science.gov (United States)

    Carrizo, Daniel; Domeño, Celia; Nerín, Isabel; Alfaro, Pilar; Nerín, Cristina

    2015-01-01

    A new screening and semi-quantitative approach has been developed for direct analysis of polycyclic aromatic hydrocarbons (PAHs) and their nitro and oxo derivatives in environmental and biological matrices using atmospheric pressure solid analysis probe (ASAP) quadrupole-time of flight mass spectrometry (Q-TOF-MS). The instrumental parameters were optimized for the analysis of all these compounds, without previous sample treatment, in soil, motor oil, atmospheric particles (ashes) and biological samples such as urine and saliva of smokers and non-smokers. Ion source parameters in the MS were found to be the key parameters, with little variation within PAHs families. The optimized corona current was 4 µA, sample cone voltage 80 V for PAHs, nitro-PAHs and oxo-PAHs, while the desolvation temperatures varied from 300°C to 500°C. The analytical method performance was checked using a certified reference material. Two deuterated compounds were used as internal standards for semi-quantitative purposes together with the pure individual standard for each compound and the corresponding calibration plot. The compounds nitro PAH 9-nitroanthracene and oxo-PAH 1,4-naphthalenedione, were found in saliva and urine in a range below 1 µg/g while the range of PAHs in these samples was below 2 µg/g. Environmental samples provided higher concentration of all pollutants than urine and saliva.

  11. Comparative study for determination of some polycyclic aromatic hydrocarbons 'PAHs' by a new spectrophotometric method and multivariate calibration coupled with dispersive liquid-liquid extraction.

    Science.gov (United States)

    Abdel-Aziz, Omar; El Kosasy, A M; El-Sayed Okeil, S M

    2014-12-10

    A modified dispersive liquid-liquid extraction (DLLE) procedure coupled with spectrophotometric techniques was adopted for simultaneous determination of naphthalene, anthracene, benzo(a)pyrene, alpha-naphthol and beta-naphthol in water samples. Two different methods were used, partial least-squares (PLS) method and a new derivative ratio method, namely extended derivative ratio (EDR). A PLS-2 model was established for simultaneous determination of the studied pollutants in methanol, by using twenty mixtures as calibration set and five mixtures as validation set. Also, in methanol a novel (EDR) method was developed for determination of the studied pollutants, where each component in the mixture of the five PAHs was determined by using a mixture of the other four components as divisor. Chemometric and EDR methods could be also adopted for determination of the studied PAH in water samples after transferring them from aqueous medium to the organic one by utilizing dispersive liquid-liquid extraction technique, where different parameters were investigated using a full factorial design. Both methods were compared and the proposed method was validated according to ICH guidelines and successfully applied to determine these PAHs simultaneously in spiked water samples, where satisfactory results were obtained. All the results obtained agreed with those of published methods, where no significant difference was observed.

  12. Amine-Amine Exchange in Aminium-Methanesulfonate Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Matthew L.; Varner, Mychel E.; Perraud, Veronique M.; Ezell, Michael J.; Wilson, Jacqueline M.; Zelenyuk, Alla; Gerber, Robert B.; Finlayson-Pitts, Barbara J.

    2014-12-18

    Aerosol particles are ubiquitous in the atmosphere and have been shown to impact the Earth’s climate, reduce visibility, and adversely affect human health. Modeling the evolution of aerosol systems requires an understanding of the species and mechanisms involved in particle growth, including the complex interactions between particle- and gas-phase species. Here we report studies of displacement of amines (methylamine, dimethylamine or trimethylamine) in methanesulfonate salt particles by exposure to a different gas-phase amine, using a single particle mass spectrometer, SPLAT II. The variation of the displacement with the nature of the amine suggests that behavior is dependent on water in or on the particles. Small clusters of methanesulfonic acid with amines are used as a model in quantum chemical calculations to identify key structural elements that are expected to influence water uptake, and hence the efficiency of displacement by gas-phase molecules in the aminium salts. Such molecular-level understanding of the processes affecting the ability of gas-phase amines to displace particle-phase aminium species is important for modeling the growth of particles and their impacts in the atmosphere.

  13. 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.

  14. 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.

  15. MICROWAVE-ASSISTED CHEMISTRY: SYNTHESIS OF AMINES AND HETEROCYCLES VIA CARBON-NITROGEN BOND FORMATION IN AQUEOUS MEDIA

    Science.gov (United States)

    Improved C-N bond formation under MW influence is demonstrated by a) solventless three-component coupling reaction to generate propargyl amines that uses only Cu (I); b) aqueous N-alkylation of amines by alkyl halides that proceeds expeditiously in the presence of NaOH to deliver...

  16. Amine Swingbed Payload Technology Demonstration

    Science.gov (United States)

    Sweterlitsch, Jeffrey

    2014-01-01

    The Amine Swingbed is an amine-based, vacuum-regenerated adsorption technology for removing carbon dioxide and humidity from a habitable spacecraft environment, and is the baseline technology for the Orion Program’s Multi-Purpose Crew Vehicle (MPCV). It uses a pair of interleaved-layer beds filled with SA9T, the amine sorbent, and a linear multiball valve rotates 270° back and forth to control the flow of air and vacuum to adsorbing and desorbing beds. One bed adsorbs CO2 and H2O from cabin air while the other bed is exposed to vacuum for regeneration by venting the CO2 and H2O. The two beds are thermally linked, so no additional heating or cooling is required. The technology can be applied to habitable environments where recycling CO2 and H2O is not required such as short duration missions.

  17. Polyvinylpolypyrrolidone-bromine complex: Mild and efficient polymeric reagent for bromination of activated aromatic compounds

    Institute of Scientific and Technical Information of China (English)

    Masoud Mokhtary; Moslem M. Lakouraj

    2011-01-01

    Mild and efficient method for bromination of electron-rich aromatic compounds is described using polyvinylpolypyrrolidonebromine complex (PVPP-Br2). The reaction proceeded smoothly with phenols and N,N-alkylated amines to afford the corresponding monobrominated product in good yields at ambient temperature.

  18. Complex amine-based reagents

    Science.gov (United States)

    Suslov, S. Yu.; Kirilina, A. V.; Sergeev, I. A.; Zezyulya, T. V.; Sokolova, E. A.; Eremina, E. V.; Timofeev, N. V.

    2017-03-01

    Amines for a long time have been applied to maintaining water chemistry conditions (WCC) at power plants. However, making use of complex reagents that are the mixture of neutralizing and the filmforming amines, which may also contain other organic components, causes many disputes. This is mainly due to lack of reliable information about these components. The protective properties of any amine with regard to metal surfaces depend on several factors, which are considered in this article. The results of applying complex reagents to the protection of heating surfaces in industrial conditions and estimated behavior forecasts for various reagents under maintaining WCC on heat-recovery boilers with different thermal circuits are presented. The case of a two-drum heat-recovery boiler with in-line drums was used as an example, for which we present the calculated pH values for various brands of reagents under the same conditions. Work with different reagent brands and its analysis enabled us to derive a composition best suitable for the conditions of their practical applications in heat-recovery boilers at different pressures. Testing the new amine reagent performed at a CCPP power unit shows that this reagent is an adequate base for further development of reagents based on amine compounds. An example of testing a complex reagent is shown created with the participation of the authors within the framework the program of import substitution and its possible use is demonstrated for maintaining WCC of power-generating units of combined-cycle power plants (CCPP) and TPP. The compliance of the employed reagents with the standards of water chemistry conditions and protection of heating surfaces were assessed. The application of amine-containing reagents at power-generating units of TPP makes it possible to solve complex problems aimed at ensuring the sparing cleaning of heating surfaces from deposits and the implementation of conservation and management of water chemistry condition

  19. Pressurized liquid extraction using water/isopropanol coupled with solid-phase extraction cleanup for semivolatile organic compounds, polycyclic aromatic hydrocarbons (PAH), and alkylated PAH homolog groups in sediment

    Science.gov (United States)

    Burkhardt, M.R.; Zaugg, S.D.; Burbank, T.L.; Olson, M.C.; Iverson, J.L.

    2005-01-01

    Polycyclic aromatic hydrocarbons (PAH) are recognized as environmentally relevant for their potential adverse effects on human and ecosystem health. This paper describes a method to determine the distribution of PAH and alkylated homolog groups in sediment samples. Pressurized liquid extraction (PLE), coupled with solid-phase extraction (SPE) cleanup, was developed to decrease sample preparation time, to reduce solvent consumption, and to minimize background interferences for full-scan GC-MS analysis. Recoveries from spiked Ottawa sand, environmental stream sediment, and commercially available topsoil, fortified at 1.5-15 ??g per compound, averaged 94.6 ?? 7.8%, 90.7 ?? 5.8% and 92.8 ?? 12.8%, respectively. Initial method detection limits for single-component compounds ranged from 20 to 302 ??g/kg, based on 25 g samples. Results from 28 environmental sediment samples, excluding homologs, show 35 of 41 compounds (85.4%) were detected in at least one sample with concentrations ranging from 20 to 100,000 ??g/kg. The most frequently detected compound, 2,6-dimethylnaphthalene, was detected in 23 of the 28 (82%) environmental samples with a concentration ranging from 15 to 907 ??g/kg. The results from the 28 environmental sediment samples for the homolog series showed that 27 of 28 (96%) samples had at least one homolog series present at concentrations ranging from 20 to 89,000 ??g/kg. The most frequently detected homolog series, C2-alkylated naphthalene, was detected in 26 of the 28 (93%) environmental samples with a concentration ranging from 25 to 3900 ??g/kg. Results for a standard reference material using dichloromethane Soxhlet-based extraction also are compared. ?? 2005 Elsevier B.V. All rights reserved.

  20. Iridium-catalyzed asymmetric ring-opening reactions of oxabicyclic alkenes with secondary amine nucleophiles

    Directory of Open Access Journals (Sweden)

    Dingqiao Yang

    2009-10-01

    Full Text Available Iridium-catalyzed asymmetric ring-opening reactions of oxabicyclic alkenes with various aliphatic and aromatic secondary amines are reported for the first time. The reaction gave the corresponding trans-1,2-dihydronaphthalenol derivatives in good yields with moderate enantioselectivities in the presence of 2.5 mol % [Ir(CODCl]2 and 5 mol % bisphosphine ligand (S-p-Tol-BINAP. The trans-configuration of 3f was confirmed by X-ray crystallography.

  1. Selective ruthenium-catalyzed transfer hydrogenations of nitriles to amines with 2-butanol.

    Science.gov (United States)

    Werkmeister, Svenja; Bornschein, Christoph; Junge, Kathrin; Beller, Matthias

    2013-04-02

    Transfer your hydrogen: Fast and general transfer hydrogenation of nitriles to form primary amines is possible with a homogeneous Ru/1,4-bis(diphenylphosphino)butane (DPPB) catalyst (see scheme). The use of 2-butanol as the hydrogen-transfer reagent is essential for the selective reduction of aromatic, heteroaromatic, and aliphatic nitriles with this system. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Debaryomyces hansenii, Proteus vulgaris, Psychrobacter sp and Microbacterium foliorum are able to produce biogenic amines

    OpenAIRE

    Hélinck, Sandra; Perello, Marie-Claire; Deetae, Pawinee; de Revel, Gilles; Spinnler, Henry-Eric

    2013-01-01

    The occurrence of biogenic amines (BAs) produced by the microbiota of fermented foods is a source of health concern. The three bacteria Microbacterium foliorum, Proteus vulgaris and Psychrobacter sp. and the yeast Debaryomyces hansenii, isolated from surface-ripened cheeses, are known to contribute to their aromatic properties. The potential of each of these strains to produce BAs was investigated, both in pure cultures of each bacterium in a laboratory medium supplemented with amino acids an...

  3. Aromater i drikkevand

    DEFF Research Database (Denmark)

    Nyeland, B. A.; Hansen, A. B.

    DMU har den 10. Juni 1997 afholdt en præstationsprøvning: Aromater i drikkevand. Der deltog 21 laboratorier i præstationsprøvningen. Prøvningen omfattede 6 vandige prøver og 6 ampuller indeholdende 6 aromater. Laboratorierne spikede de tilsendte vandprøver med indholdet fra ampullerne...

  4. Pt-Sn/γ-Al2O3-catalyzed highly efficient direct synthesis of secondary and tertiary amines and imines.

    Science.gov (United States)

    He, Wei; Wang, Liandi; Sun, Chenglin; Wu, Kaikai; He, Songbo; Chen, Jiping; Wu, Ping; Yu, Zhengkun

    2011-11-18

    Versatile syntheses of secondary and tertiary amines by highly efficient direct N-alkylation of primary and secondary amines with alcohols or by deaminative self-coupling of primary amines have been successfully realized by means of a heterogeneous bimetallic Pt-Sn/γ-Al(2)O(3) catalyst (0.5 wt % Pt, Pt/Sn molar ratio=1:3) through a borrowing-hydrogen strategy. In the presence of oxygen, imines were also efficiently prepared from the tandem reactions of amines with alcohols or between two primary amines. The proposed mechanism reveals that an alcohol or amine substrate is initially dehydrogenated to an aldehyde/ketone or NH-imine with concomitant formation of a [PtSn] hydride. Condensation of the aldehyde/ketone species or deamination of the NH-imine intermediate with another molecule of amine forms an N-substituted imine which is then reduced to a new amine product by the in-situ generated [PtSn] hydride under a nitrogen atmosphere or remains unchanged as the final product under an oxygen atmosphere. The Pt-Sn/γ-Al(2)O(3) catalyst can be easily recycled without Pt metal leaching and has exhibited very high catalytic activity toward a wide range of amine and alcohol substrates, which suggests potential for application in the direct production of secondary and tertiary amines and N-substituted imines. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Whole cell biotransformation for reductive amination reactions

    Science.gov (United States)

    Klatte, Stephanie; Lorenz, Elisabeth; Wendisch, Volker F

    2014-01-01

    Whole cell biotransformation systems with enzyme cascading increasingly find application in biocatalysis to complement or replace established chemical synthetic routes for production of, e.g., fine chemicals. Recently, we established an Escherichia coli whole cell biotransformation system for reductive amination by coupling a transaminase and an amino acid dehydrogenase with glucose catabolism for cofactor recycling. Transformation of 2-keto-3-methylvalerate to l-isoleucine by E. coli cells was improved by genetic engineering of glucose metabolism for improved cofactor regeneration. Here, we compare this system with different strategies for cofactor regeneration such as cascading with alcohol dehydrogenases, with alternative production hosts such as Pseudomonas species or Corynebacterium glutamicum, and with improving whole cell biotransformation systems by metabolic engineering of NADPH regeneration. PMID:24406456

  6. Polymeric amines and biomedical uses thereof

    NARCIS (Netherlands)

    Broekhuis, Antonius; Zhang, Youchum; Picchioni, Francesco; Roks, Antonius

    2010-01-01

    The invention relates to the field of polymers and biomedical applications thereof. In particular, it relates to the use of polymeric amines derived from alternating polyketones.Provided is the use of a polymeric amine for modulating or supporting cellular behavior, said polymeric amine being an alt

  7. Biogenic amines in fermented foods

    NARCIS (Netherlands)

    Spano, G.; Russo, P.; Lonvaud-Funel, A.; Lucas, P.; Alexandre, H.; Grandvalet, C.; Coton, E.; Coton, M.; Barnavon, L.; Bach, B.; Rattray, F.; Bunte, A.; Magni, C.; Ladero, V.; Alvarez, M.; Fernández, M.; Lopez, P.; Palencia, P.F. de; Corbi, A.; Trip, H.; Lolkema, J.S.

    2010-01-01

    Food-fermenting lactic acid bacteria (LAB) are generally considered to be non-toxic and non-pathogenic. Some species of LAB, however, can produce biogenic amines (BAs). BAs are organic, basic, nitrogenous compounds, mainly formed through decarboxylation of amino acids. BAs are present in a wide rang

  8. Aminering van hydroxyderivaten van halogeenazahetarenen

    NARCIS (Netherlands)

    Roelfsema, W.A.

    1972-01-01

    In this thesis an introductory investigation is described on the reactivity of hydroxy derivatives of halogenopyridines and a bromohydroxyquinoline towards strong bases.It is a sequel to earlier work on the effect of substituents present in the nucleus of halogenopyridines on the course of amination

  9. Advances in heterocyclic ketene aminals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Recent developments in the study of the reactions of heterocyclic ketene aminals are reviewed with the emphases on regioselective alkylation, acylation and glycosylation reactions, and on the aza-ene reactions with α,β-unsaturated compounds, azo and carbonyl compounds. Reactions with 1,3-dipoles and other reagents to synthesize fused heterocycles are also discussed.

  10. Heterogeneous uptake of amines by citric acid and humic acid.

    Science.gov (United States)

    Liu, Yongchun; Ma, Qingxin; He, Hong

    2012-10-16

    Heterogeneous uptake of methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) onto citric acid and humic acid was investigated using a Knudsen cell reactor coupled to a quadrupole mass spectrometer at 298 K. Acid-base reactions between amines and carboxylic acids were confirmed. The observed uptake coefficients of MA, DMA, and TMA on citric acid at 298 K were measured to be 7.31 ± 1.13 × 10(-3), 6.65 ± 0.49 × 10(-3), and 5.82 ± 0.68 × 10(-3), respectively, and showed independence of sample mass. The observed uptake coefficients of MA, DMA, and TMA on humic acid at 298 K increased linearly with sample mass, and the true uptake coefficients of MA, DMA, and TMA were measured to be 1.26 ± 0.07 × 10(-5), 7.33 ± 0.40 × 10(-6), and 4.75 ± 0.15 × 10(-6), respectively. Citric acid, having stronger acidity, showed a higher reactivity than humic acid for a given amine; while the steric effect of amines was found to govern the reactivity between amines and citric acid or humic acid.

  11. Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-02-01

    The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines.

  12. Thermochemical factors affecting the dehalogenation of aromatics.

    Science.gov (United States)

    Sadowsky, Daniel; McNeill, Kristopher; Cramer, Christopher J

    2013-12-17

    Halogenated aromatics are one of the largest chemical classes of environmental contaminants, and dehalogenation remains one of the most important processes by which these compounds are degraded and detoxified. The thermodynamic constraints of aromatic dehalogenation reactions are thus important for understanding the feasibility of such reactions and the redox conditions necessary for promoting them. Accordingly, the thermochemical properties of the (poly)fluoro-, (poly)chloro-, and (poly)bromobenzenes, including standard enthalpies of formation, bond dissociation enthalpies, free energies of reaction, and the redox potentials of Ar-X/Ar-H couples, were investigated using a validated density functional protocol combined with continuum solvation calculations when appropriate. The results highlight the fact that fluorinated aromatics stand distinct from their chloro- and bromo- counterparts in terms of both their relative thermodynamic stability toward dehalogenation and how different substitution patterns give rise to relevant properties, such as bond strengths and reduction potentials.

  13. 含芳环脂肪胺在室温固化耐高温环氧胶中的应用研究%On application of aliphatic amines containing aromatic ring in RT curable and heat-resistant epoxy adhesive

    Institute of Scientific and Technical Information of China (English)

    栾猛; 张培影; 欧涛; 刘龙江

    2016-01-01

    研究了2种间二甲苯二胺(MXDA)缩聚物(缩胺105和G-328)在室温固化耐高温环氧胶中的应用,测试了其贮存性、固化速度、耐高温性、刚性和韧性等性能。结果表明,缩胺105反应速度较慢,G-328反应速度较快,2种缩胺均可在室温下24 h完全固化。其中缩胺105刚性较强、韧性较差,因此耐高温性能优异,适合用于提升体系的耐高温性能;G-328韧性较好、刚性较弱,在保证一定耐高温强度情况下,可提升体系的柔韧性。%The application of two MXDA condensates(Condensed-amine 105 and G-328) in the RT curable and heat-resistant epoxy adhesive was investigated. The storage stability and curing rate of the curing agents, the heat resistance, rigidity and toughness of the cured were measured. The results show that the curing rate of Condensed-amine 105 is slower, the curing rate of G-328 is fast, and both the curing agents can be cured completely at RT for 24 h. For the products cured with Condensed-amine 105, the rigidity is better and the toughness is poor, the heat resistance is excellent, this curing agent is suitable for increasing the heat resistance of the system; for the G-328 system, the toughness is better and the rigidity is poor, so this curing agent is suitable for increasing the system flexibility in the condition of ensuring the definite high-temperature strength.

  14. The Oxidative Coupling of 2,6-Xylenol Catalyzed by Polymeric Complexes of Copper, 1. Kinetic Study of the Catalysis by Copper(II)-Complexes of Partially Aminated Polystyrene

    NARCIS (Netherlands)

    Schouten, Arend Jan; Prak, Nanno; Challa, Ger

    1977-01-01

    The oxidative coupling reaction of 2,6-xylenol catalyzed by copper(II) complexes of chemically modified polystyrene was investigated. Under the applied reaction conditions the main reaction product was 2,6,2',6'-tetramethyl-1,1'-dioxo-4,4'-bicyclohexa-2,5-dienylidene. It was found that the polymeric

  15. SHORT COMMUNICATION POLYCYCLIC AROMATIC ...

    African Journals Online (AJOL)

    a

    *Corresponding author. E-mail: omotayosharafdeen@yahoo.com ... The levels of isolated polycyclic aromatic hydrocarbons (PAH) in ash residues of .... PAH standards, PAH recoveries and percentage recoveries are given in Table 2. In all the ...

  16. Trimerization of aromatic nitriles

    Science.gov (United States)

    Hsu, L. C. (Inventor)

    1977-01-01

    Triazine compounds and cross-linked polymer compositions were made by heating aromatic nitriles to a temperature in the range of about 100 C to about 700 C, in the presence of a catalyst or mixture of catalysts. Aromatic nitrile-modified (terminated and/or appended) imide, benzimidazole, imidazopyrrolone, quinoxaline, and other condensation type prepolymers or their precopolymers were made which were trimerized with or without a filler by the aforementioned catalytic trimerization process.

  17. 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.

  18. Internal conversion mediated by specific nuclear motions: The nitrogen inversion in amines

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Liv B.; Sølling, Theis I., E-mail: theis@kiku.dk

    2014-10-17

    Graphical abstract: - Highlights: • Primary and secondary amines show different photophysical behavior to tertiary. • Deuteration in amines significantly increases decay time of parent ions. • The planarization motion is important for the rate of internal conversion. • The internal conversion in amines is a non-ergodic process. - Abstract: To investigate the influence of amine structure on the internal conversion from S{sub 2} to S{sub 1}, three aliphatic amines containing the same number of degrees of freedom, but with different degree of N-substitution, were investigated with femtosecond time-resolved mass spectrometry. As N-substituents lower the excitation energies, and the excitation in all cases is by a 200 nm photon, the S{sub 1} density-of-states in the Franck–Condon region will be high for the more N-alkylated amine. This, according to standard models, should lead to faster internal conversion. The experimental results are in contrast to this, indicating non-ergodic behavior and a coupling of the states by very few molecular vibrations. This was further investigated by substituting differing numbers of hydrogen atoms with deuterium in two amines, one primary and one tertiary, thus freezing the degrees of freedom while altering the N-substituent mass. In both case, deuteration resulted in a significantly longer lifetime of the initially excited state, confirming the importance of the N-inversion motion in the description of the dynamics of internal conversion.

  19. Visible Light Induced Green Transformation of Primary Amines to Imines Using a Silicate Supported Anatase Photocatalyst

    Directory of Open Access Journals (Sweden)

    Sifani Zavahir

    2015-01-01

    Full Text Available Catalytic oxidation of amine to imine is of intense present interest since imines are important intermediates for the synthesis of fine chemicals, pharmaceuticals, and agricultural chemicals. However, considerable efforts have been made to develop efficient methods for the oxidation of secondary amines to imines, while little attention has until recently been given to the oxidation of primary amines, presumably owing to the high reactivity of generated imines of primary amines that are easily dehydrogenated to nitriles. Herein, we report the oxidative coupling of a series of primary benzylic amines into corresponding imines with dioxygen as the benign oxidant over composite catalysts of TiO2 (anatase-silicate under visible light irradiation of λ > 460 nm. Visible light response of this system is believed to be as a result of high population of defects and contacts between silicate and anatase crystals in the composite and the strong interaction between benzylic amine and the catalyst. It is found that tuning the intensity and wavelength of the light irradiation and the reaction temperature can remarkably enhance the reaction activity. Water can also act as a green medium for the reaction with an excellent selectivity. This report contributes to the use of readily synthesized, environmentally benign, TiO2 based composite photocatalyst and solar energy to realize the transformation of primary amines to imine compounds.

  20. Metal Monolithic Amine-grafted Zeolite for CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Steven

    2011-03-31

    The solid amine sorbent for CO{sub 2} capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO{sub 2} capture capacity or low stability. The solid amine sorbent developed in this project exhibited more than 3.2 mmol/g and degraded less than 10% even after 500 cycles of heating and cooling in absence of steam. The presence of steam further enhanced CO{sub 2} capture capacity. The cost of the sorbent is estimated to be less than $7.00/lb. This sorbent was developed using the results of in situ infrared spectroscopic study. Infrared results showed that CO{sub 2} adsorbs on TEPA (tetraethylenepentamine)/PEG (polyethylene glycol) as carbamates and bicarbonates. The CO{sub 2} adsorption capacity and oxidation resistance of the amine sorbent can be enhanced by the interactions between NH{sub 2} of TEPA molecules with the OH group of PEG molecules. PEG was also found to be effectively disperse and immobilize the aromatic amines for SO{sub 2} adsorption. The infrared study also showed that SiO{sub 2} is a significantly better support than zeolites due to its proper hydrophobicity. The results of this study led to the development of a high performance solid amine sorbent under simulated gas flow condition in a fixed bed, a fluidized bed, and a metal monolith unit. This study showed heat transfer could become a major technical issue in scaling up a fixed bed adsorber. The use of the fluidized bed and metal monoliths can alleviate the heat transfer issue. The metal monolith could be suitable for small scale applications due to the high cost of manufacturing; the fluidized bed mode would be most suitable for large scale applications. Preliminary economic analysis suggested that the Akron solid amine process would cost 45% less than that of MEA process.

  1. Effect of chemical functionalization on the electrochemical properties of conducting polymers. Modification of polyaniline by diazonium ion coupling and subsequent reductive degradation

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Diego F.; Rivarola, Claudia R.; Miras, Maria C. [Departamento de Quimica, Universidad Nacional de Rio Cuarto, Ruta Nacional 8, Km 601, X5804ZAB, Rio Cuarto, Cordoba (Argentina); Barbero, Cesar A., E-mail: cbarbero@exa.unrc.edu.a [Departamento de Quimica, Universidad Nacional de Rio Cuarto, Ruta Nacional 8, Km 601, X5804ZAB, Rio Cuarto, Cordoba (Argentina)

    2011-04-01

    The electrochemical properties of polyaniline (PANI) can be altered by coupling the polymer with aryldiazonium ions. The ions are synthesized by diazotization of aromatic primary amines (1-aminoanthraquinone, sulphadiazine and 4-cyanoaniline) bearing functional groups which are then linked to the polyaniline backbone. All materials produced are electroactive, suggesting that the reaction involves coupling of the diazonium ion with the aromatic rings and not nucleophilic substitution by the aminic nitrogen of PANI on the aryl cations. The electrochemical properties of the modified polymers are different to those of PANI, likely due to electronic and steric effects of the attached groups. Reductive degradation of the azo linkages, using dithionite ion, removes the attached moieties leaving primary amino groups attached to the polyaniline backbone. In that way, the effect of the attached groups on the electrochemical properties of PANI is eliminated. FTIR spectroscopy measurement of the different polymers supports the proposed mechanism. Using the method a polymer containing redox (anthraquinone) groups, which could be used for charge storage, is obtained. Additionally a material containing sulphadiazine moieties, which can be released in vivo by bacterial activity, is also produced. The molecule is a well-known sulfa drug with bacteriostatic activity. The reaction sequence seems to be of general application to modify polyanilines, by attaching functional groups, and then to produce a PANI backbone bearing primary amino groups. Evidence is presented on the kinetic control of attached group removal.

  2. Study on Aromatization of C6 Aliphatic Hydrocarbons on ZRP Zeolite Catalyst

    Institute of Scientific and Technical Information of China (English)

    Wang Yongjun; Xie Chaogang

    2004-01-01

    The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.

  3. Cellulose sulphuric acid as a biodegradable catalyst for conversion of aryl amines into azides at room temperature under mild conditions

    Indian Academy of Sciences (India)

    Firouzeh Nesmati; Ali Elhampour

    2012-07-01

    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 converted into the corresponding aryl azides with 71-99% yields. The use of mild reaction conditions, avoids the use of harmful acids and toxic solvents and short reaction times are advantages of this methodology. The selected catalyst is found to be highly efficient and recyclable.

  4. Structural Influence on Excited State Dynamics in Simple Amines

    DEFF Research Database (Denmark)

    Klein, Liv Bærenholdt

    is femtosecond time-resolved photoelectron velocity map imaging (VMI), which is a newtechnique in the Copenhagen lab. The design, building and implementation of the VMI spectrometer has been a very substantial part of the thesis work. This techniques oers enhanced information content in the form of ecient...... and sensitive collection of photoelectron spectra. In particular, the angleresolved data available from the VMI approach provides highly detailed mechanistic insight about the relaxation pathways. One striking novel nding is that for tertiary amines, the critical factor driving the non-adiabatic dynamics...... structure. The VMI technique has been found to be very useful in investigating the nature of the coupling between the states and provides hints to the fate of the 3s state which has previously been a mystery. This is in prominent contrast to the primary and secondary amines as well as previously...

  5. Silver-catalyzed arylation of (hetero)arenes by oxidative decarboxylation of aromatic carboxylic acids.

    Science.gov (United States)

    Kan, Jian; Huang, Shijun; Lin, Jin; Zhang, Min; Su, Weiping

    2015-02-09

    A long-standing challenge in Minisci reactions is achieving the arylation of heteroarenes by oxidative decarboxylation of aromatic carboxylic acids. To address this challenge, the silver-catalyzed intermolecular Minisci reaction of aromatic carboxylic acids was developed. With an inexpensive silver salt as a catalyst, this new reaction enables a variety of aromatic carboxylic acids to undergo decarboxylative coupling with electron-deficient arenes or heteroarenes regardless of the position of the substituents on the aromatic carboxylic acid, thus eliminating the need for ortho-substituted aromatic carboxylic acids, which were a limitation of previously reported methods.

  6. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  7. 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....

  8. Anaerobic catabolism of aromatic compounds: a genetic and genomic view.

    Science.gov (United States)

    Carmona, Manuel; Zamarro, María Teresa; Blázquez, Blas; Durante-Rodríguez, Gonzalo; Juárez, Javier F; Valderrama, J Andrés; Barragán, María J L; García, José Luis; Díaz, Eduardo

    2009-03-01

    Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach.

  9. H14[NaP5W29MoO110]: a Novel and Useful Catalyst for Aminolysis of Epoxides with Amines under Solvent-Free Conditions

    Institute of Scientific and Technical Information of China (English)

    HERAVI,Majid M; BEHBAHANI,Farahnaz K; OSKOOIE,Hossien A; BAMOHARRAM,Fatemeh F

    2008-01-01

    A simple and efficient method has been developed for the synthesis of β-amino alcohols by ring opening of ep-oxides in the presence of a catalytic amount of H14[NaP5W29MoO110] at room temperature under solvent-free condi-tions. The reaction works well for both aromatic and aliphatic amines.

  10. Flotation of kaolinite with dodecyl tertiary amines

    Institute of Scientific and Technical Information of China (English)

    CAO Xue-feng; LIU Chang-miao; HU Yue-hua

    2009-01-01

    The flotation of kaolinite using a series of tertiary amines (N,N-dimethyl-dodecyl amine (DRN), N,N-diethyl-dodecyl amine (DEN), N,N-dipropyl-dodecyl amine (DPN) and N,N-dibenzyl-bodecyi amine (DBN)) was investigated. The results show that the maximum recoveries of kaolinite for DEN, DPN and DRN are 93%, 88% and 84%, respectively, but that of DBN is very low. On the basis of zeta potential and FT-IR spectra, the ionization of surface hydroxyl and isomorphic exchange of surface ions account for the charging mechanisms of kaolinite surface. The adsorption mechanism of tertiary amines on kaolinite surface is mainly electrostatic. The isoelectric point (IEP) of kaolinite increases from 3.4 to some more positive points after the interaction of kaolinite with the four tertiary amines. The FT-IR spectra of kaolinite change with the presence of some new sharp shapes belonging to the tertiary amines. The inductive electronic effects and space-steric effects of -CH_3, -C_2H_5, -C_3H_7 and -C_7H_7 bonding to N atom result in different collecting power of the four tertiary amines.

  11. The Use of 7,7′,8,8′-Tetracyanoquinodimethane for the Spectrophotometric Determination of Some Primary Amines Application to Real Water Samples

    Directory of Open Access Journals (Sweden)

    Theia'a N. Al-Sabha

    2013-01-01

    Full Text Available A sensitive, simple, and accurate spectrophotometric method was developed for the quantitative determination of some primary aliphatic and aromatic amines, that is, ethylamine, 1,2-diaminopropane, aniline, p-aminophenol, and benzidine. The method is based on the interaction of these amines in aqueous medium with 7,7′,8,8′-tetracyanoquinodimethane (TCNQ reagent in the presence of a buffer solution and surfactant (in the case of aromatic amines to form charge-transfer complexes measurable at maximum wavelengths ranging between 323 and 511 nm. Beer’s law is obeyed over the concentration ranges of 0.025 and 3.0 μg/mL and the molar absorptivity is ranged between 8.977 × 103 and 5.8034 × 104  L·mol−1·cm−1 for these amines. The method was applied for the determination of benzidine in the river, sea, and tap waters. The TCNQ complexes with the previously mentioned amines were formed in the ratio of 1 : 1 amine : TCNQ, and their stability constants ranged between 8.78 × 104 and 1.844 × 105 L·mol−1.

  12. Palladium-catalyzed amination of allyl alcohols.

    Science.gov (United States)

    Ghosh, Raju; Sarkar, Amitabha

    2011-10-21

    An efficient catalytic amination of aryl-substituted allylic alcohols has been developed. The complex [(η(3)-allyl)PdCl](2) modified by a bis phosphine ligand, L, has been used as catalyst in the reaction that afforded a wide range of allyl amines in good to excellent yield under mild conditions.

  13. 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 transamin

  14. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

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

    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*, allergen intoler*, and

  15. 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

  16. 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

  17. 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

  18. Speaking Personally--with Amin Qazi

    Science.gov (United States)

    Ragan, Lawrence

    2016-01-01

    This article provides an interview with Amin Quazi, the founding chief executive officer of Unizin, a university-owned consortium focused on the emerging digital teaching and learning ecosystem. Amin has a bachelor's degree in chemical engineering from The University of Iowa and a master's degree in business administration from the Carlson School…

  19. Dispersion Interactions and the Stability of Amine Dimers

    Science.gov (United States)

    Guttmann, Robin

    2017-01-01

    Abstract Weak, intermolecular interactions in amine dimers were studied by using the combination of a dispersionless density functional and a function that describes the dispersion contribution to the interaction energy. The validity of this method was shown by comparison of structural and energetic properties with data obtained with a conventional density functional and the coupled cluster method. The stability of amine dimers was shown to depend on the size, the shape, and the relative orientation of the alkyl substituents, and it was shown that the stabilization energy for large substituents is dominated by dispersion interactions. In contrast to traditional chemical explanations that attribute stability and condensed matter properties solely to hydrogen bonding and, thus, to the properties of the atoms forming the hydrogen bridge, we show that without dispersion interactions not even the stability and structure of the ammonia dimer can be correctly described. The stability of amine dimers depends crucially on the interaction between the non‐polar alkyl groups, which is dominated by dispersion interactions. This interaction is also responsible for the energetic part of the free energy interaction used to describe hydrophobic interactions in liquid alkanes. The entropic part has its origin in the high degeneracy of the interaction energy for complexes of alkane molecules, which exist in a great variety of conformers, having their origin in internal rotations of the alkane chains. PMID:28794953

  20. Trace amine-associated receptors are olfactory receptors in vertebrates.

    Science.gov (United States)

    Liberles, Stephen D

    2009-07-01

    The mammalian nose is a powerful chemosensor, capable of detecting and distinguishing a myriad of chemicals. Sensory neurons in the olfactory epithelium contain two types of chemosensory G protein-coupled receptors (GPCRs): odorant receptors (ORs), which are encoded by the largest gene family in mammals, and trace amine-associated receptors (TAARs), a smaller family of receptors distantly related to biogenic amine receptors. Do TAARs play a specialized role in olfaction distinct from that of ORs? Genes encoding TAARs are found in diverse vertebrates, from fish to mice to humans. Like OR genes, each Taar gene defines a unique population of canonical sensory neurons dispersed in a single zone of the olfactory epithelium. Ligands for mouse TAARs include a number of volatile amines, several of which are natural constituents of mouse urine, a rich source of rodent social cues. One chemical, 2-phenylethylamine, is reported to be enriched in the urine of stressed animals, and two others, trimethylamine and isoamylamine, are enriched in male versus female urine. Furthermore, isoamylamine has been proposed to be a pheromone that induces puberty acceleration in young female mice. These data raise the possibility that some TAARs are pheromone receptors in the nose, a hypothesis consistent with recent data suggesting that the olfactory epithelium contains dedicated pheromone receptors, separate from pheromone receptors in the vomeronasal organ. Future experiments will clarify the roles of TAARs in olfaction.

  1. Dynamics of CO 2 Adsorption on Amine Adsorbents. 2. Insights Into Adsorbent Design

    KAUST Repository

    Bollini, Praveen

    2012-11-21

    Packed bed breakthrough experiments are reported for commercial zeolite 13X and 3-aminopropyl-functionalized SBA-15 silica materials with three different amine loadings. Mass and heat transfer dynamics for all four materials are modeled successfully. Amine adsorbents with open pores are found to exhibit faster mass diffusion rates compared to zeolite 13X. When amine loading is increased by coupling aminopropyl groups, premature breakthrough combined with a long tail is observed. Contrary to conventional physisorbants, finite heat losses to the column wall do not explain the long breakthrough tail. A rate model that accounts for heterogeneity in diffusion was found to accurately capture the breakthrough shape of the high loading material. Batch uptake measurements support the hypothesis that slow diffusion through the polymer phase is what hampers adsorption kinetics in the high amine loading adsorbent. The results emphasize the importance of designing materials that are not overloaded with amine sites, as excessive amine loadings can lead to depressed adsorption kinetics and premature column breakthrough. © 2012 American Chemical Society.

  2. Density Functional Investigation of Graphene Doped with Amine-Based Organic Molecules

    Directory of Open Access Journals (Sweden)

    Yeun Hee Hwang

    2015-01-01

    Full Text Available To improve the electronic properties of graphene, many doping techniques have been studied. Herein, we investigate the electronic and molecular structure of doped graphene using density functional theory, and we report the effects of amine-based benzene dopants adsorbed on graphene. Density functional theory (DFT calculations were performed to determine the role of amine-based aromatic compounds in graphene doping. These organic molecules bind to graphene through long-range interactions such as π-π interactions and C-H⋯π hydrogen bonding. We compared the electronic structures of pristine graphene and doped graphene to understand the electronic structure of doped graphene at the molecular level. Also, work functions of doped graphene were obtained from electrostatic potential calculations. A decrease in the work function was observed when the amine-based organic compounds were adsorbed onto graphene. Because these systems are based on physisorption, there was no obvious band structure change at point K at the Fermi level after doping. However, the amine-based organic dopants did change the absolute Fermi energy levels. In this study, we showed that the Fermi levels of the doped graphene were affected by the HOMO energy level of the dopants and by the intermolecular charge transfer between the adsorbed molecules and graphene.

  3. 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

  4. Recent development in synthesis and application of amine compounds%胺类化合物合成与应用研究进展

    Institute of Scientific and Technical Information of China (English)

    牛亚男; 钟宏; 王帅; 马鑫

    2014-01-01

    The synthesis methods of amine compounds according to the various hydrocarbon groups,espe-cially the aliphatic amines and aromatic amines are reviewed. The applications in the fields of flotation, metallurgy and wastewater treatment are also introduced. Based on the review,the future research of amine compounds is presented.%主要依照烃基的不同,分类介绍胺类化合物的合成研究现状,详述了脂肪胺、芳香胺的合成。阐述了胺类化合物在矿物浮选、湿法冶金及废水处理等工业应用的进展,并由此提出胺类化合物未来研究的发展趋势。

  5. Copper-catalyzed direct amination of quinoline N-oxides via C-H bond activation under mild conditions.

    Science.gov (United States)

    Zhu, Chongwei; Yi, Meiling; Wei, Donghui; Chen, Xuan; Wu, Yangjie; Cui, Xiuling

    2014-04-04

    A highly efficient and concise one-pot strategy for the direct amination of quinoline N-oxides via copper-catalyzed dehydrogenative C-N coupling has been developed. The desired products were obtained in good to excellent yields for 22 examples starting from the parent aliphatic amines. This methodology provides a practical pathway to 2-aminoquinolines and features a simple system, high efficiency, environmental friendliness, low reaction temperature, and ligand, additives, base, and external oxidant free conditions.

  6. Uncertainties in assessing the environmental impact of amine emissions from a CO2 capture plant

    OpenAIRE

    Karl, M.; Castell, N.; Simpson, D.; Solberg, S.; J. Starrfelt; T. Svendby; S.-E. Walker; Wright, R.F.

    2014-01-01

    In this study, a new model framework that couples the atmospheric chemistry transport model system WRF-EMEP and the multimedia fugacity level III model was used to assess the environmental impact of amine emissions to air from post-combustion carbon dioxide capture. The modelling framework was applied to a typical carbon capture plant artificially placed at Mongstad, west coast of Norway. WRF-EMEP enables a detailed treatment of amine chemistry in addition t...

  7. Efficient and selective N-alkylation of amines with alcohols catalysed by manganese pincer complexes

    Science.gov (United States)

    Elangovan, Saravanakumar; Neumann, Jacob; Sortais, Jean-Baptiste; Junge, Kathrin; Darcel, Christophe; Beller, Matthias

    2016-10-01

    Borrowing hydrogen (or hydrogen autotransfer) reactions represent straightforward and sustainable C-N bond-forming processes. In general, precious metal-based catalysts are employed for this effective transformation. In recent years, the use of earth abundant and cheap non-noble metal catalysts for this process attracted considerable attention in the scientific community. Here we show that the selective N-alkylation of amines with alcohols can be catalysed by defined PNP manganese pincer complexes. A variety of substituted anilines are monoalkylated with different (hetero)aromatic and aliphatic alcohols even in the presence of other sensitive reducible functional groups. As a special highlight, we report the chemoselective monomethylation of primary amines using methanol under mild conditions.

  8. STUDIES ON RADICAL POLYMERIZATION OF METHYL METHACRYLATE INITIATED WITH ORGANIC PEROXIDE-AMINE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; SHUI Li; FENG Xinde

    1984-01-01

    Radical polymerization of methyl methacrylate (MMA) initiated with various diacyl peroxideamine systems was studied. Benzoyl peroxide (BPO) and lauroyl peroxide (LPO) were used as diacyl peroxide component, N,N-dimethyl aniline (DMA) and its para substituted derivatives, i.e., N,N-dimethyl-p-toluidine (DMT), p-hydroxymethyl-N,N-dimethyl aniline (HDMA), p-nitro-N,N-dimethyl aniline (NDMA) and p-dimethylamino benzaldehyde (DMAB) were used as amine components. It was found that the peroxide-DMT systems give higher rates of bulk polymerization Rp of MMA than the organic hydroperoxide-DMT systems with the following descending order BPO-DMT>LPO-DMT>CHP (cumene hydroperoxide)-DMT>TBH (tert-butyl hydroperoxide)-DMT.The aromatic tertiary amines possess obvious structural effect on the Rp values in the diacyl peroxideamine system. The overall activation energy of MMA polymerization was determined and the kinetics of polymerization of MMA initiated with BPO-DMT system was investigated.

  9. Side Chain Cyclized Aromatic Amino Acids

    DEFF Research Database (Denmark)

    Van der Poorten, Olivier; Knuhtsen, Astrid; Sejer Pedersen, Daniel

    2016-01-01

    Constraining the conformation of flexible peptides is a proven strategy to increase potency, selectivity, and metabolic stability. The focus has mostly been on constraining the backbone dihedral angles; however, the correct orientation of the amino acid side chains (χ-space) that constitute...... the peptide pharmacophore is equally important. Control of χ-space utilizes conformationally constrained amino acids that favor, disfavor, or exclude the gauche (-), the gauche (+), or the trans conformation. In this review we focus on cyclic aromatic amino acids in which the side chain is connected...... to the peptide backbone to provide control of χ(1)- and χ(2)-space. The manifold applications for cyclized analogues of the aromatic amino acids Phe, Tyr, Trp, and His within peptide medicinal chemistry are showcased herein with examples of enzyme inhibitors and ligands for G protein-coupled receptors....

  10. Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

    Energy Technology Data Exchange (ETDEWEB)

    Watzke, Anja; Wilson, Rebecca; O' Malley, Steven; Bergman, Robert; Ellman, Jonathan

    2007-04-16

    The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.

  11. Quantifying amine permeation sources with acid neutralization: calibrations and amines measured in coastal and continental atmospheres

    Directory of Open Access Journals (Sweden)

    N. A. Freshour

    2014-04-01

    Full Text Available An acid titration method for quantifying amine permeation rates was used to calibrate an Ambient pressure Proton transfer Mass Spectrometer (AmPMS that monitors ambient amine compounds. The method involves capturing amines entrained in a N2 flow by bubbling it through an acidified solution (~ 10−5 M HCl, and the amines are quantified via changes in solution pH with time. Home-made permeation tubes had permeation rates (typically tens of pmol s−1 that depended on the type of amine and tubing and on temperature. Calibrations of AmPMS yielded sensitivities for ammonia, methyl amine, dimethyl amine, and trimethyl amine that are close to the sensitivity assuming a gas-kinetic, ion-molecule rate coefficient. The permeation tubes were also designed to deliver a reproducible amount of amine to a flow reactor where nucleation with sulfuric acid was studied. The high proton affinity compound dimethyl sulfoxide (DMSO, linked to oceanic environments, was also studied and AmPMS is highly sensitive to it. AmPMS was deployed recently in two field campaigns and mixing ratios are reported for ammonia, alkyl amines, and DMSO and correlations between these species and with particle formation events are discussed.

  12. Biotransformation of nitro-polycyclic aromatic compounds by vegetable and fruit cell extracts

    Institute of Scientific and Technical Information of China (English)

    Bo XIE; Jun YANG; Qing YANG

    2012-01-01

    Extracts from various vegetables and fruits were investigated for their abilities to reduce nitro-polycyclic aromatic hydrocarbons (NPAHs).The extracts from grape and onion exhibited an interesting selectivity,yielding corresponding hydroxylamines or amines as major products under mild conditions of 30 ℃ and pH 7.0.Grape extracts reduced the 4-nitro-1,8-naphthalic anhydride with the highest conversion rate (>99%) and the highest ratio of hydroxylamine to amine (95:5).In contrast,the onion extracts reduced 4-nitro-1,8-naphthalic anhydride with a conversion rate of 94% and a ratio of hydroxylamine to amine of 8:92.The thiol-reducing agent,β-mercaptoethanol,and metal cations,Ca2+ and Mg2+,greatly increased the reductive efficiency.This work provides an alternative strategy for biotransformation of nitro-polycyclic compounds.

  13. "Nanorust"-catalyzed benign oxidation of amines for selective synthesis of nitriles.

    Science.gov (United States)

    Jagadeesh, Rajenahally V; Junge, Henrik; Beller, Matthias

    2015-01-01

    Organic nitriles constitute key precursors and central intermediates in organic synthesis. In addition, nitriles represent a versatile motif found in numerous medicinally and biologically important compounds. Generally, these nitriles are synthesized by traditional cyanation procedures using toxic cyanides. Herein, we report the selective and environmentally benign oxidative conversion of primary amines for the synthesis of structurally diverse aromatic, aliphatic and heterocyclic nitriles using a reusable "nanorust" (nanoscale Fe2 O3 )-based catalysts applying molecular oxygen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Interaction energies of CO2·amine complexes: effects of amine substituents.

    Science.gov (United States)

    Jorgensen, Kameron R; Cundari, Thomas R; Wilson, Angela K

    2012-10-25

    To focus on the identification of potential alternative amine carbon capture compounds, CO(2) with methyl, silyl, and trifluoromethyl monosubstituted and disubstituted amine compounds were studied. Interaction energies of these CO(2)·amine complexes were determined via two methods: (a) an ab initio composite method, the correlation consistent composite approach (ccCA), to determine interaction energies and (b) density functional theories, B3LYP/aug-cc-pVTZ and B97D/aug-cc-pVTZ. Substituent effects on the interaction energies were examined by interchanging electron donating and electron withdrawing substituents on the amine compounds. The calculations suggested two different binding modes, hydrogen bonding and acid-base interactions, which arise from the modification of the amine substituents, echoing previous work by our group on modeling protein·CO(2) interactions. Recommendations have been noted for the development of improved amine scrubber complexes.

  15. Aromaticity Competition in Differentially Fused Borepin-Containing Polycyclic Aromatics.

    Science.gov (United States)

    Messersmith, Reid E; Siegler, Maxime A; Tovar, John D

    2016-07-01

    This report describes the synthesis and characterization of a series of borepin-based polycyclic aromatics bearing two different arene fusions. The borepin synthesis features streamlined Ti-mediated alkyne reduction, leading to Z-olefins, followed by direct lithiation and borepin formation. These molecules allow for an assessment of aromatic competition between the fused rings and the central borepin core. Crystallographic, magnetic, and computational studies yielded insights about the aromaticity of novel, differentially fused [b,f]borepins and allowed for comparison to literature compounds. Multiple borepin motifs were also incorporated into polycyclic aromatics with five or six rings in the main backbone, and their properties were also evaluated.

  16. Multiple amine oxidases in cucumber seedlings.

    Science.gov (United States)

    Percival, F W; Purves, W K

    1974-10-01

    Cell-free extracts of cucumber (Cucumis sativus L. cv. National Pickling) seedlings were found to have amine oxidase activity when assayed with tryptamine as a substrate. Studies of the effect of lowered pH on the extract indicated that this activity was heterogeneous, and three amine oxidases could be separated by ion exchange chromatography. The partially purified enzymes were tested for their activities with several substrates and for their sensitivities to various amine oxidase inhibitors. One of the enzymes may be a monoamine oxidase, although it is inhibited by some diamine oxidase inhibitors. The other two enzymes have properties more characteristic of the diamine oxidases. The possible relationship of the amine oxidases to indoleacetic acid biosynthesis in cucumber seedlings is discussed.

  17. Amines as occupational hazards for visual disturbance

    Science.gov (United States)

    JANG, Jae-Kil

    2015-01-01

    Various amines, such as triethylamine and N,N-dimethylethylamine, have been reported to cause glaucopsia in workers employed in epoxy, foundry, and polyurethane foam industries. This symptom has been related to corneal edema and vesicular collection of fluid within the corneal subepithelial cells. Exposure to amine vapors for 30 min to several hours leads to blurring of vision, a blue-grey appearance of objects, and halos around lights, that are probably reversible. Concentration-effect relationships have been established. The visual disturbance is considered a nuisance, as it could cause onsite accidents, impair work efficiency, and create difficulties in driving back home. Occupational exposure limits have been established for some amines, but there is shortage of criteria. Volatility factors, such as vapor pressure, should be considered in industrial settings to prevent human ocular risks, while trying to reduce levels of hazardous amines in the atmosphere. PMID:26538000

  18. 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

  19. Structure, Function, and Evolution of Biogenic Amine-binding Proteins in Soft Ticks

    Energy Technology Data Exchange (ETDEWEB)

    Mans, Ben J.; Ribeiro, Jose M.C.; Andersen, John F. (NIH)

    2008-08-19

    Two highly abundant lipocalins, monomine and monotonin, have been isolated from the salivary gland of the soft tick Argas monolakensis and shown to bind histamine and 5-hydroxytryptamine (5-HT), respectively. The crystal structures of monomine and a paralog of monotonin were determined in the presence of ligands to compare the determinants of ligand binding. Both the structures and binding measurements indicate that the proteins have a single binding site rather than the two sites previously described for the female-specific histamine-binding protein (FS-HBP), the histamine-binding lipocalin of the tick Rhipicephalus appendiculatus. The binding sites of monomine and monotonin are similar to the lower, low affinity site of FS-HBP. The interaction of the protein with the aliphatic amine group of the ligand is very similar for the all of the proteins, whereas specificity is determined by interactions with the aromatic portion of the ligand. Interestingly, protein interaction with the imidazole ring of histamine differs significantly between the low affinity binding site of FS-HBP and monomine, suggesting that histamine binding has evolved independently in the two lineages. From the conserved features of these proteins, a tick lipocalin biogenic amine-binding motif could be derived that was used to predict biogenic amine-binding function in other tick lipocalins. Heterologous expression of genes from salivary gland libraries led to the discovery of biogenic amine-binding proteins in soft (Ornithodoros) and hard (Ixodes) tick genera. The data generated were used to reconstruct the most probable evolutionary pathway for the evolution of biogenic amine-binding in tick lipocalins.

  20. Amide Synthesis from Alcohols and Amines Catalyzed by Ruthenium N-Heterocyclic Carbene Complexes

    DEFF Research Database (Denmark)

    Dam, Johan Hygum; Osztrovszky, Gyorgyi; Nordstrøm, Lars Ulrik Rubæk

    2010-01-01

    The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems...... chloride and base. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields. The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do...... not show any significant differences in reactivity, which indicates that the same catalytically active species is operating. The reaction is believed to proceed by initial dehydrogenation of the primary alcohol to the aldehyde that stays coordinated to ruthenium and is not released into the reaction...

  1. Nanoindentation study of interphases in epoxy/amine thermosetting systems modified with thermoplastics.

    Science.gov (United States)

    Ramos, Jose Angel; Blanco, Miren; Zalakain, Iñaki; Mondragon, Iñaki

    2009-08-15

    The characterization of a mixture of epoxy/amine with different stoichiometric ratios was carried out by means of nanoindentation. The epoxy system was composed by diglycidyl ether of bisphenol-A and 4,4'-methylene bis-(3-chloro 2,6-diethylaniline). Diffusion through interface formed by epoxy/amine system in stoichiometric ratio and several thermoplastic polymers was also analyzed by means of stiffness analysis, as studied by atomic force microscopy (AFM) and coupled nanoindentation tests. Used thermoplastics were an amorphous, atactic polystyrene, and two semicrystalline, syndiotactic polystyrene and poly(phenylene sulfide). Larger range diffusion was obtained in epoxy/amine systems modified with atactic polystyrene while the study of the influence of stoichiometric ratio suggests that the excess of epoxy generated stiffer material. In addition, larger indentation loads resulted in higher apparent stiffness because of the more number of polymer chains that had to re-accommodate owing to the increase in contact area.

  2. Contorted polycyclic aromatics.

    Science.gov (United States)

    Ball, Melissa; Zhong, Yu; Wu, Ying; Schenck, Christine; Ng, Fay; Steigerwald, Michael; Xiao, Shengxiong; Nuckolls, Colin

    2015-02-17

    CONSPECTUS: This Account describes a body of research in the design, synthesis, and assembly of molecular materials made from strained polycyclic aromatic molecules. The strain in the molecular subunits severely distorts the aromatic molecules away from planarity. We coined the term "contorted aromatics" to describe this class of molecules. Using these molecules, we demonstrate that the curved pi-surfaces are useful as subunits to make self-assembled electronic materials. We have created and continue to study two broad classes of these "contorted aromatics": discs and ribbons. The figure that accompanies this conspectus displays the three-dimensional surfaces of a selection of these "contorted aromatics". The disc-shaped contorted molecules have well-defined conformations that create concave pi-surfaces. When these disc-shaped molecules are substituted with hydrocarbon side chains, they self-assemble into columnar superstructures. Depending on the hydrocarbon substitution, they form either liquid crystalline films or macroscopic cables. In both cases, the columnar structures are photoconductive and form p-type, hole- transporting materials in field effect transistor devices. This columnar motif is robust, allowing us to form monolayers of these columns attached to the surface of dielectrics such as silicon oxide. We use ultrathin point contacts made from individual single-walled carbon nanotubes that are separated by a few nanometers to probe the electronic properties of short stacks of a few contorted discs. We find that these materials have high mobility and can sense electron-deficient aromatic molecules. The concave surfaces of these disc-shaped contorted molecules form ideal receptors for the molecular recognition and assembly with spherical molecules such as fullerenes. These interfaces resemble ball-and-socket joints, where the fullerene nests itself in the concave surface of the contorted disc. The tightness of the binding between the two partners can be

  3. 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.

  4. Fluorinated aromatic diamine

    Science.gov (United States)

    Jones, Robert J. (Inventor); O'Rell, Michael K. (Inventor); Hom, Jim M. (Inventor)

    1980-01-01

    This invention relates to a novel aromatic diamine and more particularly to the use of said diamine for the preparation of thermally stable high-molecular weight polymers including, for example, polyamides, polyamideimides, polyimides, and the like. This diamine is obtained by reacting a stoichometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloronitrobenzene to obtain an intermediate, 2,2-bis[4-(4-nitrophenoxy)phenyl] hexafluoropropane, which is reduced to the corresponding 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane.

  5. Petrochemistry - Aromatics; Petrochimie - Aromatiques

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-09-01

    The assignment of Unipetrol chemical activities to the Czech group Agrofert by the Polish PKN Orlen is suspended and would be renegotiated. Oman Oil Company (OOC) is joining in the Korean LG International and in its subsidiary company Oman Refinery Company (ORC) for the construction of its new aromatics complex on its site of Sohar (Oman). This plan represents an investment of one milliard of dollars; it will produce 800000 t/year of para-xylene and 210000 t/year of benzene. The unit would be operational at the third trimester 2008. (O.M.)

  6. Selective concentration of aromatic bases from water with a resin adsorbent

    Science.gov (United States)

    Stuber, H.A.; Leenheer, J.A.

    1983-01-01

    Aromatic bases are concentrated from water on columns of a resin adsorbent and recovered by aqueous-acid elution. The degree of concentration attainable depends on the ratio of the capacity factor (k) of the neutral form of the amine to that of the ionized form. Capacity factors of ionic forms of amines on XAD-8 resin (a methylacrylic ester polymer) are greater than zero, ranging from 20 to 250 times lower than those of their neutral forms; they increase with increasing hydrophobicity of the amine. Thus, desorption by acid is an edition (k during desorption >0) rather than a displacement (k during desorption = 0) process. The degree of concentration attainable on XAD-8 resin varies with the hydrophobicity of the amine, being limited for hydrophilic solutes (for example, pyridine) by small neutral-form k's, reaching a maximum for amines of intermediate hydrophobicity (for example, quinoline), and decreasing for more hydrophobc solutes (for example, acridine) because of their large ionic-form k's.

  7. Rapid Microwave-Assisted Copper-Catalyzed Nitration of Aromatic Halides with Nitrite Salts

    Energy Technology Data Exchange (ETDEWEB)

    Paik, Seung Uk; Jung, Myoung Geun [Keimyung University, Daegu (Korea, Republic of)

    2012-02-15

    A rapid and efficient copper-catalyzed nitration of aryl halides has been established under microwave irradiation. The catalytic systems were found to be the most effective with 4-substituted aryl iodides leading to nearly complete conversions. Nitration of aromatic compounds is one of the important industrial processes as underlying intermediates in the manufacture of a wide range of chemicals such as dyes, pharmaceuticals, agrochemicals and explosives. General methods for the nitration of aromatic compounds utilize strongly acidic conditions employing nitric acid or a mixture of nitric and sulfuric acids, sometimes leading to problems with poor regioselectivity, overnitration, oxidized byproducts and excess acid waste in many cases of functionalized aromatic compounds. Several other nitrating agents or methods avoiding harsh reaction conditions have been explored using metal nitrates, nitrite salts, and ionic liquid-mediated or microwave-assisted nitrations. Recently, copper or palladium compounds have been successfully used as efficient catalysts for the arylation of amines with aryl halides under mild conditions.

  8. Recent advances in the ruthenium-catalyzed hydroarylation of alkynes with aromatics: synthesis of trisubstituted alkenes.

    Science.gov (United States)

    Manikandan, Rajendran; Jeganmohan, Masilamani

    2015-11-14

    The hydroarylation of alkynes with substituted aromatics in the presence of a metal catalyst via chelation-assisted C-H bond activation is a powerful method to synthesize trisubstituted alkenes. Chelation-assisted C-H bond activation can be done by two ways: (a) an oxidative addition pathway and (b) a deprotonation pathway. Generally, a mixture of cis and trans stereoisomeric as well as regioisomeric trisubstituted alkenes was observed in an oxidative addition pathway. In the deprotonation pathway, the hydroarylation reaction can be done in a highly regio- and stereoselective manner, and enables preparation of the expected trisubstituted alkenes in a highly selective manner. Generally, ruthenium, rhodium and cobalt complexes are used as catalysts in the reaction. In this review, a ruthenium-catalyzed hydroarylation of alkynes with substituted aromatics is covered completely. The hydroarylation reaction of alkynes with amide, azole, carbamate, phosphine oxide, amine, acetyl, sulfoxide and sulphur directed aromatics is discussed.

  9. Synthesis, Characterization, and Biological Activity of 5-Phenyl-1,3,4-thiadiazole-2-amine Incorporated Azo Dye Derivatives

    Directory of Open Access Journals (Sweden)

    Chinnagiri T. Keerthi Kumar

    2013-01-01

    Full Text Available 5-Phenyl-1,3,4-thiadiazole-2-amine has been synthesized by single step reaction. A series of heterocyclic azodyes were synthesized by diazotisation of 5-phenyl-1,3,4-thiadiazole-2-amine by nitrosyl sulphuric acid followed by coupling with different coupling compounds such as 8-hydroxyquinoline, 2,6-diaminopyridine, 2-naphthol, N,N-dimethyl aniline, resorcinol, and 4,6-dihydroxypyrimidine. The dyes were characterized by UV-Vis, IR, 1H-NMR, 13C NMR, and elemental analysis. The synthesized compounds were also screened for biological activity.

  10. "Carbo-aromaticity" and novel carbo-aromatic compounds.

    Science.gov (United States)

    Cocq, Kévin; Lepetit, Christine; Maraval, Valérie; Chauvin, Remi

    2015-09-21

    While the concept of aromaticity is being more and more precisely delineated, the category of "aromatic compounds" is being more and more expanded. This is illustrated by an introductory highlight of the various types of "aromaticity" previously invoked, and by a focus on the recently proposed "aromatic character" of the "two-membered rings" of the acetylene and butatriene molecules. This serves as a general foundation for the definition of "carbo-aromaticity", the relevance of which is surveyed through recent results in the synthetic, physical, and theoretical chemistry of carbo-mers and in particular macrocyclic-polycyclic representatives constituting a natural family of "novel aromatic compounds". With respect to their parent molecules, carbo-mers are constitutionally defined as "carbon-enriched", and can also be functionally regarded as "π-electron-enriched". This is exemplified by recent experimental and theoretical results on functional, aromatic, rigid, σ,π-macrocyclic carbo-benzene archetypes of various substitution patterns, with emphasis on the quadrupolar pattern. For the purpose of comparison, several types of non-aromatic references of carbo-benzenes are then considered, i.e. freely rotating σ,π-acyclic carbo-n-butadienes and flexible σ-cyclic, π-acyclic carbo-cyclohexadienes, and to "pro-aromatic" congeners, i.e. rigid σ,π-macrocyclic carbo-quinoids. It is shown that functional carbo-mers are entering the field of "molecular materials" for properties such as linear or nonlinear optical properties (e.g. dichromism and two-photon absorption) and single molecule conductivity. Since total or partial carbo-mers of aromatic carbon-allotropes of infinite size such as graphene (graphynes and graphdiynes) and graphite ("graphitynes") have long been addressed at the theoretical or conceptual level, recent predictive advances on the electrical, optical and mechanical properties of such carbo-materials are surveyed. Very preliminary experimental results

  11. Multilayered Thin Films from Poly(amido amine)s and DNA

    NARCIS (Netherlands)

    Hujaya, S.D.; Engbersen, J.F.J.; Paulusse, J.M.J.

    2015-01-01

    Dip-coated multilayered thin films of poly(amido amine)s (PAAs) and DNA have been developed to provide surfaces with cell-transfecting capabilities. Three types of PAAs, differing in side chain functional groups, were synthesized and characterized for their properties in forming multilayered structu

  12. Accurate determination of aldehydes in amine catalysts or amines by 2,4-dinitrophenylhydrazine derivatization.

    Science.gov (United States)

    Barman, Bhajendra N

    2014-01-31

    Carbonyl compounds, specifically aldehydes, present in amine catalysts or amines are determined by reversed-phase liquid chromatography using ultraviolet detection of their corresponding 2,4-dinitrophenylhydrazones. The primary focus has been to establish optimum conditions for determining aldehydes accurately because these add exposure concerns when the amine catalysts are used to manufacture polyurethane products. Concentrations of aldehydes determined by this method are found to vary with the pH of the aqueous amine solution and the derivatization time, the latter being problematic when the derivatization reaction proceeds slowly and not to completion in neutral and basic media. Accurate determination of aldehydes in amines through derivatization can be carried out at an effective solution pH of about 2 and with derivatization time of 20min. Hydrochloric acid has been used for neutralization of an amine. For complete derivatization, it is essential to protonate all nitrogen atoms in the amine. An approach for the determination of an adequate amount of acid needed for complete derivatization has been described. Several 0.2M buffer solutions varying in pH from 4 to 8 have also been used to make amine solutions for carrying out derivatization of aldehydes. These solutions have effective pHs of 10 or higher and provide much lower aldehyde concentrations compared to their true values. Mechanisms for the formation of 2,4-dinitrophenylhydrazones in both acidic and basic media are discussed.

  13. Reductive Amination of Aldehydes and Ketones with Primary Amines by Using Lithium Amidoborane as Reducing Reagent

    Institute of Scientific and Technical Information of China (English)

    徐维亮; 郑学丽; 吴国涛; 陈萍

    2012-01-01

    A variety of secondary amines were obtained in high isolated yields in the reductive amination of aldehydes and ketones by using lithium amidoborane as reducing agent. Compared to ammonia borane, lithium amidoborane has higher reducibility, and thus, exhibits faster reaction rate.

  14. Properties of epoxy-amine networks containing nanostructured ether-crosslinked domains

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Ying-Gev, E-mail: yhsu@mail.ntust.edu.tw [Department of Material Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Lin, Kuan-Hung; Lin, Tse-Yu; Fang, Yi-Lung [Department of Material Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Chen, Su-Chen; Sung, Yi-Ching [Department of Raw Materials and Yarns, Taiwan Textile Research Institute, New Taipei, Taiwan (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The epoxy-amine networks with nanostructured ether-crosslinked domains (NECDs) was obtained. Black-Right-Pointing-Pointer The morphology of the networks dispersed with 10-30-nm-sized NECDs was investigated by AFM. Black-Right-Pointing-Pointer The molecular-level cavity in the matrix was inferred by a molecular-size simulation. Black-Right-Pointing-Pointer The fracture toughness of the networks were reinforced up to 1.35 times that of neat epoxy. Black-Right-Pointing-Pointer The networks were more thermostable than the neat epoxy because of higher cross-linking. - Abstract: Epoxy-amine networks with a nanodomain toughener-soft nanostructured ether-crosslinked domains (NECDs), which could increase the fracture and tensile toughness of the networks, were simply obtained when a mixture of diglycidyl ether bisphenol A (DGEBA) epoxy resin and 4,4 Prime -methylene dianiline (MDA) hardener was heat-cured in the presence of varying amounts of the imidazole derivatives (called imidazoles)-1-methylimidazole (1-MI) or 2-methylimidazole (2-MI). Under these conditions, the epoxide groups in DGEBA underwent not only polyaddition with the aromatic amine of the MDA to form a hard epoxy-amine networked matrix but also anionic ring-opening polymerization by itself to build soft NECDs connected to the epoxy-amine matrix. The curing chemistry of the DGEBA/MDA mixture, both with and without the imidazoles, was studied using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The morphology of the networks dispersed with 5-30-nm-sized NECDs was investigated by atomic force microscopy (AFM). When the optimum amount ({approx}0.15-0.30 wt%) of imidazoles was added, the NECDs were effective in significantly increasing the tensile and fracture toughness and the thermal stability of the epoxy-amine networks without markedly sacrificing the glass transition temperature (T{sub g}). The novel toughening mechanism and

  15. Application of the cubic-plus-association (CPA) equation of state to complex mixtures with aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht;

    2006-01-01

    The cubic-plus-association (CPA) equation of state is applied to phase equilibria of mixtures containing alcohols, glycols, water, and aromatic or olefinic hydrocarbons. Previously, CPA has been successfully used for mixtures containing various associating compounds (alcohols, glycols, amines......, organic acids, and water) and aliphatic hydrocarbons. We show in this work that the model can be satisfactorily extended to complex vapor-liquid-liquid equilibria with aromatic or olefinic hydrocarbons. The solvation between aromatics/olefinics and polar compounds is accounted for. This is particularly...... of the model (the Soave-Redlich-Kwong (SRK) equation of state) can be obtained from mixtures with aliphatic hydrocarbons. For mixtures of glycols with aromatic hydrocarbons, two parameters have been fitted to experimental data, one in the physical (SRK) part and one in the association part of the model...

  16. 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

  17. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  18. Neurotransmitter Amines in Hemorrhagic Shock.

    Science.gov (United States)

    1984-03-02

    the vascular effect we have observed, nifedipine is preventing an influx of Ca++ into the cytosol. Lehninger 7) has called attention to the fact that...Neurochitur 63:259-265, 1982. 17. Lehninger AL: Role of phosphate and other proton donating cations in respiration-coupled transport of Ca++ by

  19. CCN activity of aliphatic amine secondary aerosol

    Directory of Open Access Journals (Sweden)

    X. Tang

    2014-01-01

    Full Text Available Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical. The particle composition can contain both secondary organic aerosol (SOA and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN activity. SOA formed from trimethylamine (TMA and butylamine (BA reactions with hydroxyl radical (OH is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ ≤ 0.25. Secondary aerosol formed from the tertiary aliphatic amine (TMA with N2O5 (source of nitrate radical, NO3, contains less volatile compounds than the primary aliphatic amine (BA aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have κ ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR ideal mixing rules. Higher CCN activity (κ > 0.3 was also observed for humid BA+N2O5 aerosols compared with dry aerosol (κ ~ 0.2, as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N · HNO3. Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 °C temperature difference, evaporates BA+N2O5 aerosol formed at RH ≥ 30%; κ ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems κ ranges from 0.2 < κ < 0.7. This work indicates that

  20. Theoretical and Experimental Studies of the Inclusion Phenomena ofβ-Cyclodextrin with Organic Amines

    Institute of Scientific and Technical Information of China (English)

    SONG Le-Xin; WANG Hai-Ming; TENG Chuan-Feng; BAI Lei; XU Peng; GUO Xue-Qing

    2008-01-01

    The inclusion complexations of β-cyclodextrin (β-CD) with ethylenediamine 1 and its three analogs,diethylenetriamine 2,triethylamine 3 and ethylene diaminetetraacetic acid 4 were examined by means of both experimental measurements and theoretical calculations.From the polarimetric method,it was found that β-CD could form 1/1 host-guest inclusion complexes with these guests,and the formation constants (k)of the inclusion complexes have also been determined in aqueous solution at 298.2 K.Semiempirical PM3 calculations were carried out to assess the intermolecular binding ability of β-CD to a series of short chain aliphatic amines such as guests 1--7,cyclic aliphatic amines 8--11,and aromatic amines 12--13.The interaction processes between β-CD and the guests were reported,and the complexation differences of β-CD with these guests also discussed.The energy contribution from deformation energy or hydrate energy to interaction energy in the inclusion systems was found to be quite small.The stability of β-CD inclusion complexes depended on the size fit between the host and guest.For β-CD complexes of guests 1--4,the order of the K values from the polarimetric measurements is in good accordance with that of the absolute values of the complexation energies from PM3 calculations.

  1. Optimization of ultrasonic extraction and clean-up protocol for the determination of polycyclic aromatic hydrocarbons in marine sediments by high-performance liquid chromatography coupled with fluorescence detection

    Science.gov (United States)

    Peng, Xuewei; Yan, Guofang; Li, Xianguo; Guo, Xinyun; Zhou, Xiao; Wang, Yan

    2012-09-01

    The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.

  2. Optimization of Ultrasonic Extraction and Clean-up Protocol for the Determination of Polycyclic Aromatic Hydrocarbons in Marine Sediments by High-performance Liquid Chromatography Coupled with Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    PENG Xuewei; YAN Guofang; LI Xianguo; GUO Xinyun; ZHOU Xiao; WANG Yan

    2012-01-01

    The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons(PAHs)in marine sediments.Samples were ultrasonically extracted,and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography(HPLC)with a fluorescence detector.Ultrasonication with methanol-dichloromethane(2:1,v/v)mixture gave higher extraction efficiency than that with dichloromethane.Among the three elution solvents used in clean-up step,dichloromethane-hexane(2:3,v/v)mixture was the most satisfactory.Under the optimized conditions,the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank,and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix,were obtained for the 15 PAHs studied,while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%.The detection limits were between 0.75ngL-1 and 10.99ngL-1for different PAHs.A sample from the Jiaozhou Bay area was examined to test the established methods.

  3. Fast automated dual-syringe based dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

    Science.gov (United States)

    Guo, Liang; Tan, Shufang; Li, Xiao; Lee, Hian Kee

    2016-03-18

    An automated procedure, combining low density solvent based solvent demulsification dispersive liquid-liquid microextraction (DLLME) with gas chromatography-mass spectrometry analysis, was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Capitalizing on a two-rail commercial autosampler, fast solvent transfer using a large volume syringe dedicated to the DLLME process, and convenient extract collection using a small volume microsyringe for better GC performance were enabled. Extraction parameters including the type and volume of extraction solvent, the type and volume of dispersive solvent and demulsification solvent, extraction and demulsification time, and the speed of solvent injection were investigated and optimized. Under the optimized conditions, the linearity ranged from 0.1 to 50 μg/L, 0.2 to 50 μg/L, and 0.5 to 50 μg/L, depending on the analytes. Limits of detection were determined to be between 0.023 and 0.058 μg/L. The method was applied to determine PAHs in environmental water samples.

  4. 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.

  5. Biogenic amines in raw and processed seafood

    Directory of Open Access Journals (Sweden)

    Pierina eVisciano

    2012-06-01

    Full Text Available The presence of biogenic amines in raw and processed seafood, associated with either time/temperature conditions or food technologies is discussed in the present paper from a safety and prevention point of view. In particular, storage temperature, handling practices, presence of microbial populations with decarboxylase activity and availability of free amino acids are considered the most important factors affecting the production of biogenic amines in raw seafood. On the other hand, some food technological treatments such as salting, ripening, fermentation or marination can increase the levels of biogenic amines in processed seafood. The consumption of high amount of biogenic amines, above all histamine, can result in food borne poisoning which is a worldwide problem. The European Regulation established as maximum limits for histamine, in fishery products from fish species associated with high histidine amounts, values ranging from 100 to 200 mg/kg, while for products which have undergone enzyme maturation treatment in brine, the aforementioned limits rise to 200 and 400 mg/kg. Preventive measures and emerging methods aiming at controlling the production of biogenic amines are also reported for potential application in seafood industries.

  6. Asymmetric Aminalization via Cation-Binding Catalysis

    DEFF Research Database (Denmark)

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk

    2017-01-01

    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope...... of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc......-protected alkyl- and aryl-substituted α-amido sulfones. In-situ generated imines smoothly reacted with the nitrogen nucleophiles to corresponding aminals with good to excellent enantioselectivitiy under mild reaction conditions. In addition, transformation of aminal products gave biologically relevant...

  7. Amine permeation sources characterized with acid neutralization and sensitivities of an amine mass spectrometer

    Science.gov (United States)

    Freshour, N. A.; Carlson, K. K.; Melka, Y. A.; Hinz, S.; Panta, B.; Hanson, D. R.

    2014-10-01

    An acid titration method for quantifying amine permeation rates was used to calibrate an Ambient pressure Proton transfer Mass Spectrometer (AmPMS) that monitors ambient amine compounds. The method involves capturing amines entrained in a N2 flow by bubbling it through an acidified solution (~10-5 M HCl), and the amines are quantified via changes in solution pH with time. Home-made permeation tubes had permeation rates (typically tens of pmol s-1) that depended on the type of amine and tubing and on temperature. Calibrations of AmPMS yielded sensitivities for ammonia, methylamine, dimethylamine, and trimethylamine that are close to the sensitivity assuming a gas-kinetic, ion-molecule rate coefficient. The permeation tubes were also designed to deliver a reproducible amount of amine to a flow reactor where nucleation with sulfuric acid was studied. The high proton affinity compound dimethyl sulfoxide (DMSO), linked to oceanic environments, was also studied and AmPMS is highly sensitive to it. AmPMS was deployed recently in two field campaigns and, using these sensitivities, mixing ratios for ammonia and the alkyl amines are derived from the signals. Correlations between these species and with particle formation events are discussed.

  8. Thermodynamics of mixtures containing amines. IX. Application of the concentration-concentration structure factor to the study of binary mixtures containing pyridines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.es [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos; Garcia de la Fuente, Isaias; Mozo, Ismael [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

    2009-10-10

    Binary mixtures formed by a pyridine base and an alkane, or an aromatic hydrocarbon, or a 1-alkanol have been studied in the framework of the concentration-concentration structure factor, S{sub CC}(0), formalism. Deviations between experimental data and those provided by the DISQUAC model are discussed. Systems containing alkanes are characterized by homocoordination. In pyridine + alkane mixtures, S{sub CC}(0) decreases with the chain length of the longer alkanes, due to size effects. For a given alkane, S{sub CC}(0) also decreases with the number of CH{sub 3}- groups in the pyridine base. This has been interpreted assuming that the number of amine-amine interactions available to be broken upon mixing also decreases similarly, probably as steric hindrances exerted by the methyl groups of the aromatic amine increase with the number of these groups. Homocoordination is higher in mixtures with 3,5-dimethylpyridine than in those with 2,6-dimethylpyridine. That is, steric effects exerted by methyl groups in positions 3 and 5 are stronger than when they are in positions 2 and 6. Similarly, from the application of the DISQUAC (dispersive-quasichemical) model, it is possible to conclude that homocoordination is higher in systems with 3- or 4-methylpyridine than in those involving 2-methylpyridine. Systems including aromatic hydrocarbons are nearly ideal, which seems to indicate that there is no specific interaction in such solutions. Mixtures with 1-alkanols show heterocoordination. This reveals the existence of interactions between unlike molecules, characteristic of alkanol + amine mixtures. Methanol systems show the lowest S{sub CC}(0) values due, partially, to size effects. This explains the observed decrease of homocoordination in such solutions in the order: pyridine > 2-methylpyridine > 2,6-dimethylpyridine. Moreover, as the energies of the OH-N hydrogen bonds are practically independent of the pyridine base considered when mixed with methanol, it suggests that

  9. Miniscale Liquid-Liquid Extraction Coupled with Full Evaporation Dynamic Headspace Extraction for the Gas Chromatography/Mass Spectrometric Analysis of Polycyclic Aromatic Hydrocarbons with 4000-to-14 000-fold Enrichment.

    Science.gov (United States)

    Liew, Christina Shu Min; Li, Xiao; Lee, Hian Kee

    2016-09-20

    A new sample preparation approach of combining a miniscale version of liquid-liquid extraction (LLE), termed miniscale-LLE (msLLE), with automated full evaporation dynamic headspace extraction (FEDHS) was developed. Its applicability was demonstrated in the extraction of several polycyclic aromatic hydrocarbons (PAHs) (acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene) from aqueous samples. In the first step, msLLE was conducted with 1.75 mL of n-hexane, and all of the extract was vaporized through a Tenax TA sorbent tube via a nitrogen gas flow, in the FEDHS step. Due to the stronger π-π interaction between the Tenax TA polymer and PAHs, only the latter, and not n-hexane, was adsorbed by the sorbent. This selectivity by the Tenax TA polymer allowed an effective concentration of PAHs while eliminating n-hexane by the FEDHS process. After that, thermal desorption was applied to the PAHs to channel them into a gas chromatography/mass spectrometric (GC/MS) system for analysis. Experimental parameters affecting msLLE (solvent volume and mixing duration) and FEDHS (temperature and duration) were optimized. The obtained results achieved low limits of detection (1.85-3.63 ng/L) with good linearity (r(2) > 0.9989) and high enrichment factors ranging from 4200 to 14 100. The optimized settings were applied to the analysis of canal water sampled from an industrial area and tap water, and this methodology was compared to stir-bar sorptive extraction (SBSE). This innovative combined extraction-concentration approach proved to be fast, effective, and efficient in determining low concentrations of PAHs in aqueous samples.

  10. Interaction between hypocrellin and aliphatic amines

    Institute of Scientific and Technical Information of China (English)

    张曼华; 陈申; 夏万林; 蒋丽金; 陈德文

    1996-01-01

    The interaction of hypocrellin, including hypocrellin A (HA) and hypocrellin B (HB), with aliphatic amines in deaerated solutions has been studied by ESR and nanosecond transient absorption spectra. In polar solvents, the acid-base interaction between hypocrellin and amines was observed without irradiation. The signals of semiquinone radical anions of hypocrellm and the spin-trapping adduct of α-phenyl-N-tertbutyl-ratrone (PNB) with the aminoalkyl radicals have been detected in photoinduced ESR studies. The transient absorption of excited triplet state of HA and semiquinone radical anion of HA have been observed in laser flash photolysis studies.

  11. Advances towards aromatic oligoamide foldamers

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Plesner, Malene; Dissing, Mette Marie

    2014-01-01

    -ray crystallographic analysis of two of these dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a comparatively more closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation with a more open, extended structure...... of the surrounding aromatic backbone. Investigation of the X-ray structures of two arylopeptoid dimers disclosed that the tert-butyl side chain invokes a cis amide conformation with a closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation...

  12. Molecular Evolution and Functional Divergence of Trace Amine-Associated Receptors.

    Directory of Open Access Journals (Sweden)

    Seong-Il Eyun

    Full Text Available Trace amine-associated receptors (TAARs are a member of the G-protein-coupled receptor superfamily and are known to be expressed in olfactory sensory neurons. A limited number of molecular evolutionary studies have been done for TAARs so far. To elucidate how lineage-specific evolution contributed to their functional divergence, we examined 30 metazoan genomes. In total, 493 TAAR gene candidates (including 84 pseudogenes were identified from 26 vertebrate genomes. TAARs were not identified from non-vertebrate genomes. An ancestral-type TAAR-like gene appeared to have emerged in lamprey. We found four therian-specific TAAR subfamilies (one eutherian-specific and three metatherian-specific in addition to previously known nine subfamilies. Many species-specific TAAR gene duplications and losses contributed to a large variation of TAAR gene numbers among mammals, ranging from 0 in dolphin to 26 in flying fox. TAARs are classified into two groups based on binding preferences for primary or tertiary amines as well as their sequence similarities. Primary amine-detecting TAARs (TAAR1-4 have emerged earlier, generally have single-copy orthologs (very few duplication or loss, and have evolved under strong functional constraints. In contrast, tertiary amine-detecting TAARs (TAAR5-9 have emerged more recently and the majority of them experienced higher rates of gene duplications. Protein members that belong to the tertiary amine-detecting TAAR group also showed the patterns of positive selection especially in the area surrounding the ligand-binding pocket, which could have affected ligand-binding activities and specificities. Expansions of the tertiary amine-detecting TAAR gene family may have played important roles in terrestrial adaptations of therian mammals. Molecular evolution of the TAAR gene family appears to be governed by a complex, species-specific, interplay between environmental and evolutionary factors.

  13. Acid-base bifunctional catalysis of silica-alumina-supported organic amines for carbon-carbon bond-forming reactions.

    Science.gov (United States)

    Motokura, Ken; Tomita, Mitsuru; Tada, Mizuki; Iwasawa, Yasuhiro

    2008-01-01

    Acid-base bifunctional heterogeneous catalysts were prepared by the reaction of an acidic silica-alumina (SA) surface with silane-coupling reagents possessing amino functional groups. The obtained SA-supported amines (SA-NR2) were characterized by solid-state 13C and 29Si NMR spectroscopy, FT-IR spectroscopy, and elemental analysis. The solid-state NMR spectra revealed that the amines were immobilized by acid-base interactions at the SA surface. The interactions between the surface acidic sites and the immobilized basic amines were weaker than the interactions between the SA and free amines. The catalytic performances of the SA-NR2 catalysts for various carbon-carbon bond-forming reactions, such as cyano-ethoxycarbonylation, the Michael reaction, and the nitro-aldol reaction, were investigated and compared with those of homogeneous and other heterogeneous catalysts. The SA-NR2 catalysts showed much higher catalytic activities for the carbon-carbon bond-forming reactions than heterogeneous amine catalysts using other supports, such as SiO2 and Al2O3. On the other hand, homogeneous amines hardly promoted these reactions under similar reaction conditions, and the catalytic behavior of SA-NR2 was also different from that of MgO, which was employed as a typical heterogeneous base. An acid-base dual-activation mechanism for the carbon-carbon bond-forming reactions is proposed.

  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. Toward the Control of the Creation of Mixed Monolayers on Glassy Carbon Surfaces by Amine Oxidation.

    Science.gov (United States)

    Groppi, Jessica; Bartlett, Philip N; Kilburn, Jeremy D

    2016-01-18

    A versatile and simple methodology for the creation of mixed monolayers on glassy carbon (GC) surfaces was developed, using an osmium-bipyridyl complex and anthraquinone as model redox probes. The work consisted in the electrochemical grafting on GC of a mixture of mono-protected diamine linkers in varying ratios which, after attachment to the surface, allowed orthogonal deprotection. After optimisation of the deprotection conditions, it was possible to remove one of the protecting groups selectively, couple a suitable osmium complex and cap the residual free amines. The removal of the second protecting group allowed the coupling of anthraquinone. The characterisation of the resulting surfaces by cyclic voltammetry showed the variation of the surface coverage of the two redox centres in relation to the initial ratio of the linking amine in solution.

  16. Effects of marinating on heterocyclic amine carcinogen formation in grilled chicken.

    Science.gov (United States)

    Salmon, C P; Knize, M G; Felton, J S

    1997-05-01

    This study compared heterocyclic aromatic amines in marinated and unmarinated chicken breast meat flame-broiled on a propane grill. Chicken was marinated prior to grilling and the levels of several heterocyclic amines formed during cooking were determined by solid-phase extraction and HPLC. Compared with unmarinated controls, a 92-99% decrease in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was observed in whole chicken breast marinated with a mixture of brown sugar, olive oil, cider vinegar, garlic, mustard, lemon juice and salt, then grilled for 10, 20, 30 or 40 min. Conversely, 2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) increased over 10-fold with marinating, but only at the 30 and 40 min cooking times. Marinating reduced the total detectable heterocyclic amines from 56 to 1.7 ng/g, from 158 to 10 ng/g and from 330 to 44 ng/g for grilling times of 20, 30 and 40 min, respectively. The mutagenic activity of the sample extracts was also measured, using the Ames/Salmonella assay. Mutagenic activity was lower in marinated samples cooked for 10, 20 and 30 min, but higher in the marinated samples cooked for 40 min, compared with unmarinated controls. Although a change in free amino acids, which are heterocyclic amine precursors, might explain the decrease in PhIP and increase in MeIQx, no such change was detected. Marinating chicken in one ingredient at a time showed that sugar was involved in the increased MeIQx, but the reason for the decrease in PhIP was unclear. PhIP decreased in grilled chicken after marinating with several individual ingredients. This work shows that marinating is one method that can significantly reduce PhIP concentration in grilled chicken.

  17. Tertiary amines nucleophilicity in quaternization reaction with benzyl chloride

    Directory of Open Access Journals (Sweden)

    Ksenia S. Yutilova

    2016-03-01

    Full Text Available Quaternization reaction of tertiary amines with benzyl chloride was investigated. Reaction orders with respect to the reactants were determined. Kinetic scheme of quaternization reaction was found to be corresponding to reversible process. An influence of amines basicity and steric factor of alkyl substituent bound to the nitrogen atom on tertiary amines reactivity as nucleophiles was studied. It was shown that the rate constants of direct reaction step may serve as a measure of nucleophilicity of amines.

  18. Research Progress in the Construction of Aromatic C—N Bond from Activation of Aromatic C—H Bond%直接活化芳香C—H键构建芳香C—N键的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐娟; 魏真; 李加荣

    2012-01-01

    Amines are important compounds that are found throughout the pharmaceutical, bioactive natural products and agrochemical industries. The transformation from aromatic C—H bond to aromatic C—N bond is an important organic conversion. It is an effective method for the construction of aromatic amine. This transformation has the characteristic of atom economy, sustainable development and environment friendly. This review is focused on the research progress in the direct amination of C—H bonds in the past decade.%芳香C—N键广泛存在于药物、活性天然产物和农药中,其构建方法是目前合成热点之一.芳香C—H键到芳香C—N键的转化是重要的有机转化类型,这种转化是构成芳胺的一种高效方法.这种直接转化具有原子经济性,可持续发展性以及环境友好的特点.主要以芳香C—H键的氮宾插入和氧化胺化为主线,综述了近十年来该领域的研究进展.

  19. Trace amine-associated receptor 1-Family archetype or iconoclast?

    Science.gov (United States)

    Grandy, David K

    2007-12-01

    Interest has recently been rekindled in receptors that are activated by low molecular weight, noncatecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the "trace amines" (TA) beta-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of 2 publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers Borowsky et al. as TA1 and Bunzow et al. as TA receptor 1 (TAR1). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines, recombinant rodent and human TAR dose-dependently couple to the stimulation of adenosine 3',5'-monophosphate (cAMP) production. Structure-activity profiling based on this functional response has revealed that in addition to the TA, other biologically active compounds containing a 2-carbon aliphatic side chain linking an amino group to at least 1 benzene ring are potent and efficacious TA receptor agonists with amphetamine (AMPH), methamphetamine, 3-iodothyronamine, thyronamine, and dopamine (DA) among the most notable. Almost 100 years after the search for TAR began, numerous TA1/TAR1-related sequences, now called TA-associated receptors (TAAR), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TAR, a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCR. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast.

  20. Effects of aniline--an aromatic amine to some freshwater organisms.

    Science.gov (United States)

    Bhunia, Falguni; Saha, Nimai Chandra; Kaviraj, Anilava

    2003-10-01

    We determined the acute and chronic toxicity of aniline to tilapia (Oreochromis mossambicus), cladoceran crusatcea (Moina micrura) and oligochaete worm (Branchiura sowerbyi) using static bioassay tests. The 96h LC50 values of aniline for O. mossambicus, M. micrura and B. sowerbyi were 69.4, 0.6 and 586 mg l(-1) respectively. Tilapia responded to even low concentrations of aniline: the fish lost appetite at aniline concentrations as low as 0.02 mg l(-1). A 90 d outdoor bioassay with tilapia showed that 0.02 mg l(-1) aniline reduced fish yield, specific growth rate and food conversion efficiency. Reproductive functions of fish were affected by aniline at a concentration of 0.5 mg l(-1) and above. Dissolved oxygen, primary productivity and plankton population of the test medium also were significantly reduced at 2.65 and 6.94 mg l(-1) aniline.

  1. Selective oxidation of primary substituted aromatic amines to azoxy products using lacunary catalyses

    Institute of Scientific and Technical Information of China (English)

    A.Nezhadali; M.Akbarpour

    2010-01-01

    Some of the substituted anilines were selectively converted in to the corresponding azoxy and azobenzenes by oxidation with 30%aqueous hydrogen peroxide.The reactions were catalyzed by various heteropolyoxometalates,at boiling point of the used solvents.An improvement in the product yield and selectivity towards azoxybenzens was also observed.Azobenzenes was obtained as by-product.In the all similar cases,the highest yield of azoxy compounds was observed using K_5PW_(11) ZnO_(39) as catalyst in N,N-dimet...

  2. Cancer risk assessment of azo dyes and aromatic amines from garment and footwear

    NARCIS (Netherlands)

    Zeilmaker MJ; Kroese ED; van Haperen P; van Veen MP; Bremmer HJ; van Kranen HJ; Wouters MFA; Janus J; LBM

    1999-01-01

    Dit rapport beschrijft een schatting voor het risico op kanker dat verbonden is aan het dragen van kleding en schoeisel waarin kankerverwekkende azo kleurstoffen aangetroffen zijn. In de risicoschatting wordt de (geschatte) hoeveelheid aromatische aminen die tijdens het dragen van kleding en schoei

  3. Ionic liquid based dispersive liquid-liquid microextraction of aromatic amines in water samples

    Institute of Scientific and Technical Information of China (English)

    Yun Chang Fan; Zheng Liang Hu; Mei Lan Chen; Chao Shen Tu; Yan Zhu

    2008-01-01

    In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.

  4. CAPILLARY ELECTROPHORESIS METHODS FOR THE SEPARATION OF CARCINOGENIC HETEROCYCLIC AROMATIC AMINES. (R824100)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. DETERMINATION OF IONIZATION CONSTANTS OF HETEROCYCLIC AROMATIC AMINES USING CAPILLARY ZONE ELECTROPHORESIS. (R824100)

    Science.gov (United States)

    Capillary zone electrophoresis (CZE) is a very convenient technique for the determination of ionization constants. The technique is rapid, precise, uses small quantities of solute, and the exact concentration of the compound is not needed. This work represents the first report on...

  6. Synthesis and Biological Evaluation of Norcantharidin Derivatives Possessing an Aromatic Amine Moiety as Antifungal Agents

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-12-01

    Full Text Available Based on the structure of naturally produced cantharidin, different arylamine groups were linked to the norcantharidin scaffold to provide thirty six compounds. Their structures were confirmed by melting point, 1H-NMR, 13C-NMR and HRMS-ESI studies. These synthetic compounds were tested as fungistatic agents against eight phytopathogenic fungi using the mycelium growth rate method. Of these thirty six derivatives, seven displayed stronger antifungal activity than did norcantharidin, seven showed higher activity than did cantharidin and three exhibited more significant activity than that of thiabendazole. In particular, 3-(3′-chloro-phenylcarbamoyl norcantharidate II-8 showed the most significant fungicidal activity against Sclerotinia fructigena and S. sclerotiorum, with IC50 values of 0.88 and 0.97 μg/mL, respectively. The preliminary structure-activity relationship data of these compounds revealed that: (1 the benzene ring is critical for the improvement of the spectrum of antifungal activity (3-phenylcarbamoyl norcantharidate II-1 vs norcantharidin and cantharidin; (2 among the three sites, including the C-2′, C-3′ and C-4′ positions of the phenyl ring, the presence of a halogen atom at the C-3′position of the benzene ring caused the most significant increase in antifungal activity; (3 compounds with strongly electron-drawing or electron-donating groups substitutions were found to have a poor antifungal activity; and (4 compared with fluorine, bromine and iodine, chlorine substituted at the C-3′ position of the benzene ring most greatly promoted fungistatic activity. Thus, compound II-8 has emerged as new lead structure for the development of new fungicides.

  7. Aromatic Amines Exert Contrasting Effects on the Anticoagulant Effect of Acetaldehyde upon APTT

    Directory of Open Access Journals (Sweden)

    La'Teese Hall

    2014-01-01

    Full Text Available The pharmacological effects of amphetamine, procaine, procainamide, DOPA, isoproterenol, and atenolol upon activated partial thromboplastin time in the absence and presence of acetaldehyde have been investigated. In the absence of acetaldehyde, amphetamine and isoproterenol exhibit a procoagulant effect upon activated partial thromboplastin time, whereas atenolol and procaine display anticoagulant effects upon activated partial thromboplastin time. DOPA and procainamide do not alter activated partial thromboplastin time. Premixtures of procaine with acetaldehyde produce an additive anticoagulant effect on activated partial thromboplastin time, suggesting independent action of these compounds upon clotting factors. Premixtures of amphetamine with acetaldehyde, as well as atenolol with acetaldehyde, generate a detoxication of the anticoagulant effect of acetaldehyde upon activated partial thromboplastin time. A similar statistically significant decrease in activated partial thromboplastin time is seen when procainamide is premixed with acetaldehyde for 20 minutes at room temperature. Premixtures of DOPA and isoproterenol with acetaldehyde do not affect an alteration in activated partial thromboplastin time relative to acetaldehyde alone. Hence, a selective interaction of atenolol, procaine, and amphetamine with acetaldehyde to produce detoxication of the acetaldehyde is suggested, undoubtedly due to the presence of amino, hydroxyl, or amide groups in these drugs.

  8. Risk factors for bladder cancer in a cohort exposed to aromatic amines

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, P.A.; Ringen, K.; Hemstreet, G.P.; Altekruse, E.B.; Gullen, W.H.; Tillett, S.; Allsbrook, W.C. Jr.; Crosby, J.H.; Witherington, R.; Stringer, W.

    1986-11-01

    Occupational and nonoccupational risk factors for bladder cancer were analyzed in a cohort of 1385 workers with known exposure to a potent bladder carcinogen, beta-naphthylamine. Bladder cancer was approximately seven times (95% confidence interval (CI) = 3.9, 12.4) more likely in exposed rather than nonexposed individuals, yet, otherwise, the groups were generally similar in other exogenous or hereditary risk factors. A total of 13 cases of bladder cancer were identified. After the first year of a screening program involving 380 members of the cohort, 9 of the 13 cases of bladder cancer and 36 persons with atypical bladder cytology, histology, or pathology were compared with 335 noncases for distributions of different variables. Occupational variables were significant in a multivariate model that controlled for age, cigarette smoking history, and source of drinking water. The estimated odds ratio for the association for bladder cancer and the duration of employment, when controlling of these other variables, is 4.3 (95% CI = 1.8, 10.3). In addition to the occupational factors, age was significant in the multivariate analysis. Other potential risk factors, such as consumption of coffee or artificial sweeteners, use of phenacetin, or decreased use of vitamin A were not found to be significantly different in cases and noncases.

  9. Uncertainties in assessing the environmental impact of amine emissions from a CO2 capture plant

    OpenAIRE

    Karl, M.; Castell, N.; Simpson, D.; Solberg, S.; J. Starrfelt; T. Svendby; Walker, S.-E.; Wright, R.F.

    2014-01-01

    In this study, a new model framework that couples the atmospheric chemistry transport model system Weather Research and Forecasting–European Monitoring and Evaluation Programme (WRF-EMEP) and the multimedia fugacity level III model was used to assess the environmental impact of in-air amine emissions from post-combustion carbon dioxide capture. The modelling framework was applied to a typical carbon capture plant artificially placed at Mongstad, on the west coast of ...

  10. Developmental expression analysis and immunolocalization of a biogenic amine receptor in Schistosoma mansoni

    OpenAIRE

    El-Shehabi, Fouad; Vermeire, Jon J.; Yoshino, Timothy P.; Ribeiro, Paula

    2009-01-01

    A Schistosoma mansoni G-protein coupled receptor (SmGPCR) was previously cloned and shown to be activated by the biogenic amine, histamine. Here we report a first investigation of the receptor’s subunit organization, tissue distribution and expression levels in different stages of the parasite. A polyclonal antibody was produced in rabbits against the recombinant third intracellular loop (il3) of SmGPCR. Western blot studies of the native receptor and recombinant protein expressed in HEK293 c...

  11. 纳米氧化铜催化碘代芳烃的氨基化反应%Ligand-free copper(Ⅱ)-catalyzed amination of aryl iodides

    Institute of Scientific and Technical Information of China (English)

    吕良忠; 徐欢; 丁元华; 刘伟; 袁宇

    2012-01-01

    针对硝基化合物还原制备芳香胺中反应条件苛刻、适用范围较小、副产物较多、产品质量欠佳等缺陷,研究出一种以纳米氧化铜为催化剂、氨水为氨源且无配体参与的一步合成芳香伯胺的方法.该方法具有原料价廉、反应条件温和、对环境友好等优点,为芳香胺的合成增添了新的途径.%Reduction of nitro substituted aromatic compounds is the main method for preparation of aromatic amines in industry at present. However, the conventional synthetic methods often have relatively harsh reaction conditions, small scope of application, unavoidable by-products, poor selectivity, poor product quality and other shortcomings. This paper develops one step method of ligand-free nano copper oxide catalyzed amination reaction of aryl iodides with ammonia. Aqueous NH3 solution is a convenient and inexpensive source of ammonia. The synthesis method with mild conditions and environmental friendliness, has added a new method for synthesizing primary aromatic amines.

  12. Oxidant-free conversion of primary amines to nitriles.

    Science.gov (United States)

    Tseng, Kuei-Nin T; Rizzi, Andrew M; Szymczak, Nathaniel K

    2013-11-06

    An amide-derived NNN-Ru(II) hydride complex catalyzes oxidant-free, acceptorless, and chemoselective dehydrogenation of primary and secondary amines to the corresponding nitriles and imines with liberation of dihydrogen. The catalyst system tolerates oxidizable functionality and is selective for the dehydrogenation of primary amines (-CH2NH2) in the presence of amines without α-CH hydrogens.

  13. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Science.gov (United States)

    2010-07-01

    ..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6140 Dialkyldithiophosphoric acid, aliphatic amine salt. (a) Chemical... as a dialkyldithiophosphoric acid, aliphatic amine salt (P-90-1839) is subject to reporting under...

  14. 基于表面等离子共振GGBP胺耦合绑定的葡萄糖浓度测量影响因素%Influencing Factors in Glucose Concentration Detection by Surface Plasmon Resonance with GGBP Amine Coupling

    Institute of Scientific and Technical Information of China (English)

    伍鹏; 栗大超; 杨佳; 朱芮; 徐可欣

    2012-01-01

    The glucose concentration of human interstitial fluid is closely related to that of human blood. The minimally invasive blood glucose monitoring can be realized by measuring the glucose concentration of interstitial fluid. Considering the complexity of the interstitial fluid, the D-galactose/D-glucose binding protein (GGBP) which can specifically absorb glucose molecules can be used to modify the surface plasmon resonance (SPR) sensor with amine coupling method to realize glucose selective measurement. The measuring process is complicated, so the factors which influence the measurement accuracy need to be evaluated to obtain the optimized measurement condition. A SPR glucose concentration detection system based on a miniature integrated SPR sensor was set up, the factors affecting the measurement results were studied systemically by experiments, including protein purification, protein activity, baseline, flow velocity, mass transfer effect, temperature and bubble, and some solutions were proposed accordingly. The study optimizes the measurement process and provides important instruction for the standardization and development of miniaturization instrument.%人体组织液中的葡萄糖浓度与血糖浓度密切相关,微创血糖检测通过测量组织液中的葡萄糖浓度来预测血糖浓度,而组织液中成分复杂,利用对葡萄糖有特异性吸附作用的D-半乳糖/D-葡萄糖结合蛋白(GGBP)胺耦合绑定修饰表面等离子共振(SPR)传感器可以实现葡萄糖选择性测量.但是由于测量过程复杂,需要对影响测量精度的因素进行评价,确定最佳测量条件,以微型SPR传感器为核心搭建了一套葡萄糖浓度测量系统,系统地分析研究了GGBP胺耦合绑定SPR葡萄糖浓度测量过程中的各种影响因素,在不同实验条件下进行了测量实验,获得了蛋白质纯化、蛋白质活性、基线、流速、传质效应、温度和气泡等对测量结果的影响机制,提出了相应的解

  15. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  16. OCTAVIUS: evaluation of flexibility and operability of amine based post combustion CO2 capture at the Brindisi Pilot Plant

    NARCIS (Netherlands)

    Mangiaracina, A.; Zangrilli, L.; Robinson, L.; Kvamsdal, H.M.; Os, P.J. van

    2014-01-01

    Solvent storage is an option for amine based post combustion capture that can be used to de-couple the capture of CO2 and the energy demand of the process. In this process, electricity output of a power station is temporarily increased by diverting steam from the CO2 capture plant back to the steam

  17. OCTAVIUS: evaluation of flexibility and operability of amine based post combustion CO2 capture at the Brindisi Pilot Plant

    NARCIS (Netherlands)

    Mangiaracina, A.; Zangrilli, L.; Robinson, L.; Kvamsdal, H.M.; Os, P.J. van

    2014-01-01

    Solvent storage is an option for amine based post combustion capture that can be used to de-couple the capture of CO2 and the energy demand of the process. In this process, electricity output of a power station is temporarily increased by diverting steam from the CO2 capture plant back to the steam

  18. New adducts of Lapachol with primary amines

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Mirelly D.F.; Litivack-Junior, Jose T.; Antunes, Roberto V.; Silva, Tania M.S.; Camara, Celso A., E-mail: ccelso@dq.ufrpe.b [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Quimica

    2011-07-01

    New adducts of lapachol with neat primary aliphatic amines were obtained in a solvent-free reaction in good to reasonable yields (52 to 88%), at room temperature. The new compounds containing a phenazine moiety were obtained from suitable functionalized aminoalkyl compounds, including ethanolamine, 3-propanolamine, 2-methoxy-ethylamine, 3-methoxy-propylamine, n-butylamine and 2-phenetylamine. (author)

  19. PEMIKIRAN QASIM AMIN TENTANG EMANSIPASI WANITA

    Directory of Open Access Journals (Sweden)

    Eliana Siregar

    2017-02-01

    Full Text Available The aim of this research is to explore the idea belong to Qosim Amin "Tahrir al-Mar'ah" as the main theme  of Qasim Amin reformation is an idea that is based on the spirit of liberation and empowerment of women. This idea emerged as a reflection and manifestation of concern intellectualism against the reality of Egyptian woman, who had reached the threshold of tolerance limits area . By using library research method, this research used book, journal, and others as the data resouces. As the cosequency, content analysis was used to analyse the data. Qasim Amin stresses that Islam should be granted rights of women in proportion tha is the right in education and acquire  same right in tasting educational right between men and women, because Islaic value is full of fairness and required the responsibility to Allah. The resut of this research shows that Qosim Amin concern on vision and educational issues in his Idea. There was an awareness of Egytianson the important position of women on education, chance of women to wear veily the government’s attention on the revision of religions justice. These changes have in fired the Egypt women todays.

  20. Catalytic Amination of Alcohols, Aldehydes, and Ketones

    Science.gov (United States)

    Klyuev, M. V.; Khidekel', M. L.

    1980-01-01

    Data on the catalytic amination of alcohols and carbonyl compounds are examined, the catalysts for these processes are described, and the problems of their effectiveness, selectivity, and stability are discussed. The possible mechanisms of the reactions indicated are presented. The bibliography includes 266 references.

  1. Affective disorder: studies with amine precursors.

    Science.gov (United States)

    Dunner, D L; Fieve, R R

    1975-02-01

    The authors assessed the clinical antidepressant effects of L-tryptophan given alone and in combination with L-dopa in 12 patients with a diagnosis of primary affective disorder; Preliminary results did not demonstrate an antidepressant response when L-dopa was combined with L-tryptophan. Also, the results did not support the catecholamine or biogenic amine hypotheses of affective disorder.

  2. Enantioselective amine α-functionalization via palladium-catalysed C-H arylation of thioamides

    Science.gov (United States)

    Jain, Pankaj; Verma, Pritha; Xia, Guoqin; Yu, Jin-Quan

    2017-02-01

    Saturated aza-heterocycles are highly privileged building blocks that are commonly encountered in bioactive compounds and approved therapeutic agents. These N-heterocycles are also incorporated as chiral auxiliaries and ligands in asymmetric synthesis. As such, the development of methods to functionalize the α-methylene C-H bonds of these systems enantioselectively is of great importance, especially in drug discovery. Currently, enantioselective lithiation with (-)-sparteine followed by Pd(0) catalysed cross-coupling to prepare α-arylated amines is largely limited to pyrrolidines. Here we report a Pd(II)-catalysed enantioselective α-C-H coupling of a wide range of amines, which include ethyl amines, azetidines, pyrrolidines, piperidines, azepanes, indolines and tetrahydroisoquinolines. Chiral phosphoric acids are demonstrated as effective anionic ligands for the enantioselective coupling of methylene C-H bonds with aryl boronic acids. This catalytic reaction not only affords high enantioselectivities, but also provides exclusive regioselectivity in the presence of two methylene groups in different steric environments.

  3. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  4. Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

    OpenAIRE

    Katja Hofmann; Ingolf Kahle; Frank Simon; Stefan Spange

    2010-01-01

    Novel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by N...

  5. Zirconacyclopentadiene-annulated polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kiel, Gavin R.; Ziegler, Micah S.; Tilley, T. Don [Department of Chemistry, University of California, Berkeley, CA (United States)

    2017-04-18

    Syntheses of large polycyclic aromatic hydrocarbons (PAHs) and graphene nanostructures demand methods that are capable of selectively and efficiently fusing large numbers of aromatic rings, yet such methods remain scarce. Herein, we report a new approach that is based on the quantitative intramolecular reductive cyclization of an oligo(diyne) with a low-valent zirconocene reagent, which gives a PAH with one or more annulated zirconacyclopentadienes (ZrPAHs). The efficiency of this process is demonstrated by a high-yielding fivefold intramolecular coupling to form a helical ZrPAH with 16 fused rings (from a precursor with no fused rings). Several other PAH topologies are also reported. Protodemetalation of the ZrPAHs allowed full characterization (including by X-ray crystallography) of PAHs containing one or more appended dienes with the ortho-quinodimethane (o-QDM) structure, which are usually too reactive for isolation and are potentially valuable for the fusion of additional rings by Diels-Alder reactions. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. 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.

  7. CCN activity of aliphatic amine secondary aerosol

    Science.gov (United States)

    Tang, X.; Price, D.; Praske, E.; Vu, D.; Purvis-Roberts, K.; Silva, P. J.; Cocker, D. R., III; Asa-Awuku, A.

    2014-01-01

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ ≤ 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3), contains less volatile compounds than the primary aliphatic amine (BA) aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have κ ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. Higher CCN activity (κ > 0.3) was also observed for humid BA+N2O5 aerosols compared with dry aerosol (κ ~ 0.2), as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N · HNO3). Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 °C temperature difference, evaporates BA+N2O5 aerosol formed at RH ≥ 30%; κ ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss) settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems κ ranges from 0.2 systems.

  8. Amide Synthesis from Alcohols and Amines by the Extrusion of Dihydrogen

    DEFF Research Database (Denmark)

    Nordstrøm, Lars Ulrik Rubæk; Vogt, Henning; Madsen, R.

    2008-01-01

    An environmentally friendly method for synthesis of amides is presented where a simple ruthenium catalyst mediates the direct coupling between an alcohol and an amine with the liberation of two molecules of dihydrogen. The active catalyst is generated in situ from an easily available ruthenium...... complex, an N-heterocyclic carbene and a phosphine. The reaction allows primary alcohols to be coupled with primary alkyamines to afford the corresponding secondary amides in good yields. The amide formation presumably proceeds through a catalytic cycle where the intermediate aldehyde and hemiaminal...... are both coordinated to the metal catalyst....

  9. Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

    Science.gov (United States)

    Córdova-Sintjago, Tania; Villa, Nancy; Fang, Lijuan; Booth, Raymond G.

    2014-02-01

    The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists - in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

  10. Photochemically induced oscillations of aromatic pentazadienes

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, T.; Hahn, C.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Aromatic pentazadienes are used to enhance the laser induced ablation of standard polymers with low absorption in the UV. Therefore the photochemistry of substituted 1,5-diaryl-3-alkyl-1,4-pentazadiene monomers was studied with a pulsed excimer laser as irradiation source. The net photochemical reaction proceeds in an overall one-step pathway A{yields}B. Quantum yields for the laser decomposition were determined to be up to 10%. An oscillating behaviour of the absorption was found during the dark period following the irradiation. The temperature dependence of this dark reaction has been studied. An attempt to model this behaviour in terms of a non-linear coupling between heat released, heat transfer, and reaction kinetics will be described. (author) 4 figs., 4 refs.

  11. Development of a general non-noble metal catalyst for the benign amination of alcohols with amines and ammonia.

    Science.gov (United States)

    Cui, Xinjiang; Dai, Xingchao; Deng, Youquan; Shi, Feng

    2013-03-11

    The N-alkylation of amines or ammonia with alcohols is a valuable route for the synthesis of N-alkyl amines. However, as a potentially clean and economic choice for N-alkyl amine synthesis, non-noble metal catalysts with high activity and good selectivity are rarely reported. Normally, they are severely limited due to low activity and poor generality. Herein, a simple NiCuFeOx catalyst was designed and prepared for the N-alkylation of ammonia or amines with alcohol or primary amines. N-alkyl amines with various structures were successfully synthesized in moderate to excellent yields in the absence of organic ligands and bases. Typically, primary amines could be efficiently transformed into secondary amines and N-heterocyclic compounds, and secondary amines could be N-alkylated to synthesize tertiary amines. Note that primary and secondary amines could be produced through a one-pot reaction of ammonia and alcohols. In addition to excellent catalytic performance, the catalyst itself possesses outstanding superiority, that is, it is air and moisture stable. Moreover, the magnetic property of this catalyst makes it easily separable from the reaction mixture and it could be recovered and reused for several runs without obvious deactivation.

  12. Aerobic dehydrogenative α-diarylation of benzyl ketones with aromatics through carbon-carbon bond cleavage.

    Science.gov (United States)

    More, Nagnath Yadav; Jeganmohan, Masilamani

    2014-02-01

    Substituted benzyl ketones reacted with aromatics in the presence of K2S2O8 in CF3COOH at room temperature, yielding α-diaryl benzyl ketones through a carbon-carbon bond cleavage. In the reaction, two new carbon-carbon bonds were formed and one carbon-carbon bond was cleaved. It is very interesting that two different nucleophiles such as benzyl ketones and aromatics were coupled together without metal, which is unusual in organic synthesis.

  13. Aromatic-Aromatic Interactions in Biological System: Structure Activity Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, Appavu; Deepa, Mohan [Molecular Biophysics Unit, Indian Institute of Sciences-Bangalore, Karnataka (India); Govindaraju, Munisamy [Bio-Spatial Technology Research Unit, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India)

    2016-02-26

    While, intramolecular hydrogen bonds have attracted the greatest attention in studies of peptide conformations, the recognition that several other weakly polar interactions may be important determinants of folded structure has been growing. Burley and Petsko provided a comprehensive overview of the importance of weakly polar interactions, in shaping protein structures. The interactions between aromatic rings, which are spatially approximate, have attracted special attention. A survey of the proximal aromatic residue pairs in proteins, allowed Burley and Petsko to suggest that, “phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approximately 90° are most common”.

  14. Sonophotocatalytic Degradation of Amines in Water

    Science.gov (United States)

    Verman, Mayank; Pankaj

    Hazardous effects of various amines, produced in the environment from the partial degradation of azo dyes and amino acids, adversely affect the quality of human life through water, soil and air pollution and therefore needed to be degraded. A number of such studies are already available in the literature, with or without the use of ultrasound, which have been summarized briefly. The sonochemical degradation of amines and in the combination with a photocatalyst, TiO2 has also been discussed. Similar such degradation studies for ethylamine (EA), aniline (A), diphenylamine (DPA) and naphthylamine (NA) in the presence of ultrasound, TiO2 and rare earths (REs); La, Pr, Nd, Sm and Gd, in aqueous solutions at 20 kHz and 250 W power have been carried out and reported, to examine the combinatorial efficacy of ultrasound in the presence of a photocatalyst and rare earth ions with reactive f-electrons.

  15. 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.)

  16. Organic chemistry. Strain-release amination.

    Science.gov (United States)

    Gianatassio, Ryan; Lopchuk, Justin M; Wang, Jie; Pan, Chung-Mao; Malins, Lara R; Prieto, Liher; Brandt, Thomas A; Collins, Michael R; Gallego, Gary M; Sach, Neal W; Spangler, Jillian E; Zhu, Huichin; Zhu, Jinjiang; Baran, Phil S

    2016-01-15

    To optimize drug candidates, modern medicinal chemists are increasingly turning to an unconventional structural motif: small, strained ring systems. However, the difficulty of introducing substituents such as bicyclo[1.1.1]pentanes, azetidines, or cyclobutanes often outweighs the challenge of synthesizing the parent scaffold itself. Thus, there is an urgent need for general methods to rapidly and directly append such groups onto core scaffolds. Here we report a general strategy to harness the embedded potential energy of effectively spring-loaded C-C and C-N bonds with the most oft-encountered nucleophiles in pharmaceutical chemistry, amines. Strain-release amination can diversify a range of substrates with a multitude of desirable bioisosteres at both the early and late stages of a synthesis. The technique has also been applied to peptide labeling and bioconjugation.

  17. Catalytic dehydrogenation of amine borane complexes

    Science.gov (United States)

    Mohajeri, Nahid (Inventor); Tabatabaie-Raissi, Ali (Inventor); Bokerman, Gary (Inventor)

    2009-01-01

    A method of generating hydrogen includes the steps of providing an amine borane (AB) complex, at least one hydrogen generation catalyst, and a solvent, and mixing these components Hydrogen is generated. The hydrogen produced is high purity hydrogen suitable for PEM fuel cells. A hydrolytic in-situ hydrogen generator includes a first compartment that contains an amine borane (AB) complex, a second container including at least one hydrogen generation catalyst, wherein the first or second compartment includes water or other hydroxyl group containing solvent. A connecting network permits mixing contents in the first compartment with contents in the second compartment, wherein high purity hydrogen is generated upon mixing. At least one flow controller is provided for controlling a flow rate of the catalyst or AB complex.

  18. Characterization of aromatic glycosides in the extracts of Trollius species by ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Wu, Li-Zhen; Zhang, Xiao-Po; Xu, Xu-Dong; Zheng, Qing-Xia; Yang, Jun-Shan; Ding, Wan-Long

    2013-03-05

    Ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF MS/MS) was used to investigate the MS fragmentation behaviors of flavone C-glycosides present in the extracts of five Trollius species. In this study, the primary MS fragmentation pathways and key diagnostic fragment ions of flavone C-glycosides were systematically investigated and summarized to distinguish different types of derivatives and to trace other analogs in Trollius species. This method was useful, rapid, efficient and sensitive and allowed the simultaneous identification of different types of flavone C-glycosides present in other medicinal plants. The features of the MS fragmentation of these compounds indicated that the product ions were primarily the result of cleavage in the saccharide moiety, followed by hydrogen rearrangement and dehydration. In this study, thirty-six components including thirty-two flavone C-glycosides, two flavone O-glycosides and two phenylethanoid glycosides, were identified in the extracts of five Trollius species. Eleven of the flavone C-glycosides were identified by comparison with reference standards, and twenty-one flavone C-glycosides were tentatively identified based on their retention times, exact mass information and fragment ions. Two potentially new flavone C-glycosides (2″-O-vanilloylorientin and 2″-O-feruloylvitexin) were successfully characterized based on the summarized fragmentation pathways, and six known flavone C-glycosides (2″-O-glucosylvitexin, 2″-O-acetylorientin, 2″-O-acetylvitexin, 3″-O-acetylorientin, 3″-O-acetylvitexin and 6″-O-acetylvitexin) were identified in these plant species for the first time. In conclusion, the fragmentation pathways proposed in this paper were helpful for the identification of different types of flavone C-glycosides when no reference standards were available.

  19. From lignin to cycloparaffins and aromatics: directional synthesis of jet and diesel fuel range biofuels using biomass.

    Science.gov (United States)

    Bi, Peiyan; Wang, Jicong; Zhang, Yajing; Jiang, Peiwen; Wu, Xiaoping; Liu, Junxu; Xue, He; Wang, Tiejun; Li, Quanxin

    2015-05-01

    The continual growth in commercial aviation fuels and more strict environmental legislations have led to immense interest in developing green aviation fuels from biomass. This paper demonstrated a controllable transformation of lignin into jet and diesel fuel range hydrocarbons, involving directional production of C8-C15 aromatics by the catalytic depolymerization of lignin into C6-C8 low carbon aromatic monomers coupled with the alkylation of aromatics, and the directional production of C8-C15 cycloparaffins by the hydrogenation of aromatics. The key step, the production of the desired C8-C15 aromatics with the selectivity up to 94.3%, was achieved by the low temperature alkylation reactions of the lignin-derived monomers using ionic liquid. The synthetic biofuels basically met the main technical requirements of conventional jet fuels. The transformation potentially provides a useful way for the development of cycloparaffinic and aromatic components in jet fuels using renewable lignocellulose biomass.

  20. Amine reactivity with charged sulfuric acid clusters

    Science.gov (United States)

    Bzdek, B. R.; Ridge, D. P.; Johnston, M. V.

    2011-08-01

    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)(H2SO4)x]- and [(NH4)x(HSO4)x+1(H2SO4)3]-. Dimethylamine substitution for ammonia in [(NH4) x(HSO4) x+1(H2SO4)3]- 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. Therefore, in locations where amine levels are within a few orders of magnitude of ammonia levels, amine chemistry may compete favorably with ammonia chemistry.