Propheromones that release pheromonal carbonyl compounds in light.

Science.gov (United States)

Liu, X; Macaulay, E D; Pickett, J A

1984-05-01

Pheromonal carbonyl compounds; (Z)-11-hexadecanal, (E)-citral, and 2-heptanone were treated with six alcohols to give acetals or ketals, some of which acted as propheromones by releasing the pheromonal carbonyl compounds in ultraviolet or simulated sunlight. Highest yields of pheromone were obtained from adducts prepared witho-nitrobenzyl alcohol ando-nitrophenylethane-1,2-diol. Adducts from (Z)-11-hexadecenal and these two alcohols were employed in lures to catch diamondback moths,Plutella xylostella (L.).

Spatiotemporal distribution of carbonyl compounds in China

International Nuclear Information System (INIS)

Ho, K.F.; Ho, Steven Sai Hang; Huang, R.-J.; Dai, W.T.; Cao, J.J.; Tian, Linwei; Deng, W.J.

2015-01-01

A sampling campaign was carried out at nine Chinese cities in 2010/2011. Fifteen monocarbonyls (C#= 1–9) were quantified. Temperature is the rate-determining factor of the summertime carbonyl levels. The carbonyl emissions in winter are mainly driven by the primary anthropogenic sources like automobile. A molar ratio of propionaldehyde to nonaldehyde is a barometer of the impact of atmospheric vegetation emission which suggesting that strong vegetation emissions exist in summer and high propionaldehyde abundance is caused by fossil fuel combustion in winter. Potential health risk assessment of formaldehyde and acetaldehyde was conducted and the highest cumulative risks were observed at Chengdu in summer and Wuhan in winter. Because of the strong photochemical reaction and large amount of anthropogenic emissions, high concentrations of carbonyl compounds were observed in Chengdu. The use of ethanol-blended gasoline in Wuhan is the key reason of acetaldehyde emission and action should be taken to avoid potential health risks. - Highlights: • A national wide survey of ambient carbonyl compounds were conducted in China. • Using ethanol-blended gasoline can lead to higher cancer risks. • High concentrations of HMW carbonyls (C6, C7, C8 and C9) were observed in all cities. • HMW carbonyls (C6–C9) species show a very consistent seasonal variation. • C 3 /C 9 acts as an indicator for the impact of vegetation emission in the atmosphere. - Capsule abstract: Strong vegetation emission occurs in summer atmosphere and high acetaldehyde emission due to ethanol-blended gasoline consumption in 9 Chinese cities is discouraged

Emissions of carbonyl compounds from various cookstoves in China

International Nuclear Information System (INIS)

Zhang, J.; Smith, K.R.; Univ. of California, Berkeley, CA

1999-01-01

This paper presents a new database of carbonyl emission factors for commonly used cookstoves in China. The emission factors, reported both on a fuel-mass basis (mg/kg) and on a defined cooking-task basis (mg/task), were determined using a carbon balance approach for 22 types of fuel/stove combinations. These include various stoves using different species of crop residues and wood, kerosene, and several types of coals and gases. The results show that all the tested cookstoves produced formaldehyde and acetaldehyde and that the vast majority of the biomass stoves produced additional carbonyl compounds such as acetone, acrolein, propionaldehyde, crotonaldehyde, 2-butanone, isobutyraldehyde, butyraldehyde, isovaleraldehyde, valeraldehyde, hexaldehyde, benzaldehyde, o-tolualdehyde, m,p-tolualdehyde, and 2,4-dimethylbenzaldehyde. Carbonyls other than formaldehyde and acetaldehyde, however, were rarely generated by burning coal, coal gas, and natural gas. Kerosene and LPG stoves generated more carbonyl compounds than coal, coal gas, and natural gas stoves, but less than biomass stoves. Indoor levels of carbonyl compounds for typical village houses during cooking hours, estimated using a mass balance model and the measured emission factors, can be high enough to cause acute health effects documented for formaldehyde exposure, depending upon house parameters and individuals' susceptibility

Comparison of carbonyl compounds emissions from diesel engine fueled with biodiesel and diesel

Science.gov (United States)

He, Chao; Ge, Yunshan; Tan, Jianwei; You, Kewei; Han, Xunkun; Wang, Junfang; You, Qiuwen; Shah, Asad Naeem

The characteristics of carbonyl compounds emissions were investigated on a direct injection, turbocharged diesel engine fueled with pure biodiesel derived from soybean oil. The gas-phase carbonyls were collected by 2,4-dinitrophenylhydrazine (DNPH)-coated silica cartridges from diluted exhaust and analyzed by HPLC with UV detector. A commercial standard mixture including 14 carbonyl compounds was used for quantitative analysis. The experimental results indicate that biodiesel-fueled engine almost has triple carbonyls emissions of diesel-fueled engine. The weighted carbonyls emission of 8-mode test cycle of biodiesel is 90.8 mg (kW h) -1 and that of diesel is 30.7 mg (kW h) -1. The formaldehyde is the most abundant compound of carbonyls for both biodiesel and diesel, taking part for 46.2% and 62.7% respectively. The next most significant compounds are acetaldehyde, acrolein and acetone for both fuels. The engine fueled with biodiesel emits a comparatively high content of propionaldehyde and methacrolein. Biodiesel, as an alternative fuel, has lower specific reactivity (SR) caused by carbonyls compared with diesel. When fueled with biodiesel, carbonyl compounds make more contribution to total hydrocarbon emission.

Deuterium enrichment by selective photo-induced dissociation of an organic carbonyl compound

International Nuclear Information System (INIS)

Marling, J.B.

1981-01-01

A deuterium-enriched material is produced by selective photoinduced dissociation of a gas phase organic carbonyl compound containing at least one hydrogen atom bonded to an atom adjacent to a carbonyl group. Alkyl carbonyl compounds such as acetone, acetaldehyde, trifluoroacetic acid, cyclobutanone, cyclopentanone, methyl acetate, 3,3-dimethyl-2-butanone, 2,4-pentanedione, and 4-methyl-2-pentanone are preferred. The carbonyl compound is subjected to intense infrared radiation from one laser, or two lasers operating at different frequencies, to selectively dissociate the deuterated molecules into stable products. The undissociated compound may be redeuterated by direct aqueous liquid phase H/D exchange, or by indirect liquid phase exchange using an alkanol in an intermediate step

Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

Science.gov (United States)

Ho, K. F.; Lee, S. C.; Chiu, Gloria M. Y.

Volatile organic compounds (VOCs), PAHs and carbonyl compounds are the major toxic components in Hong Kong. Emissions from motor vehicles have been one of the primary pollution sources in the metropolitan areas throughout Hong Kong for a long time. A 1-yr monitoring program for VOCs, PAHs and carbonyl compounds had been performed at a roadside urban station at Hong Kong Polytechnic University in order to determine the variations and correlations of each selected species (VOCs, PAHs and carbonyl compounds). This study is aimed to analyze toxic volatile organic compounds (benzene, toluene, ethylbenzene and xylene), two carbonyl compounds (formaldehyde, acetaldehyde), and selective polycyclic aromatic hydrocarbons. The monitoring program started from 16 April 1999 to 30 March 2000. Ambient VOC concentrations, many of which originate from the same sources as particulate PAHs and carbonyls compounds, show significant quantities of benzene, toluene and xylenes. Correlations and multivariate analysis of selected gaseous and particulate phase organic pollutants were performed. Source identification by principle component analysis and hierarchical cluster analysis allowed the identification of four sources (factors) for the roadside monitoring station. Factor 1 represents the effect of diesel vehicle exhaust. Factor 2 shows the contribution of aromatic compounds. Factor 3 explains photochemical products—formaldehyde and acetaldehyde. Factor 4 explains the effect of gasoline vehicle exhaust.

Fast and efficient method for reduction of carbonyl compounds with NaBH4 /wet SiO2 under solvent free condition

International Nuclear Information System (INIS)

Zeynizadeh, Behzad; Bahyar, Tarifeh

2005-01-01

Reduction of structurally different carbonyl compounds such as aldehydes, ketones, α,β-unsaturated enals and enones, α-diketones and acyloins were accomplished efficiently by sodium borohydride in the presence of wet SiO 2 (30% m/m) under solvent free condition. The reactions were performed at room temperature or 75-80 deg C with high to excellent yields of the corresponding products. The chemoselective reduction of aldehydes over ketones was achieved successfully with this reducing system. (author)

Determination of Carbonyl Compounds in Exhaled Cigarette Smoke

Directory of Open Access Journals (Sweden)

Moldoveanu S

2014-12-01

Full Text Available This paper presents the findings on a quantitative evaluation of carbonyl levels in exhaled cigarette smoke from human subjects. The cigarettes evaluated include products with 5.0 mg ‘tar’, 10.6 mg ‘tar’ and 16.2 mg ‘tar’, where ‘tar’ is defined as the weight of total wet particulate matter (TPM minus the weight of nicotine and water, and the cigarettes are smoked following U.S. Federal Trade Commission (FTC recommendations. The measured levels of carbonyls in the exhaled smoke were compared with calculated yields of carbonyls in the inhaled smoke and a retention efficiency was obtained. The number of human subjects included a total of ten smokers for the 10.6 mg ‘tar’, five for the 16.2 mg ‘tar’, and five for the 5.0 mg ‘tar’ product, each subject smoking three cigarettes. The analyzed carbonyl compounds included several aldehydes (formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde and n-butyraldehyde, and two ketones (acetone and 2-butanone. The smoke collection from the human subjects was vacuum assisted. Exhaled smoke was collected on Cambridge pads pretreated with a solution of dinitrophenylhydrazine (DNPH followed by high performance liquid chromatography (HPLC analysis of the dinitrophenylhydrazones of the carbonyl compounds. The cigarette butts from the smokers were collected and analyzed for nicotine. The nicotine levels for the cigarette butts from the smokers were used to calculate the level of carbonyls in the inhaled smoke, based on calibration curves. These were generated separately by analyzing the carbonyls in smoke and the nicotine in the cigarette butts obtained by machine smoking under different puffing regimes. The comparison of the level of carbonyl compounds in exhaled smoke with that from the inhaled smoke showed high retention of all the carbonyls. The retention of aldehydes was above 95% for all three different ‘tar’ levels cigarettes. The ketones were retained with a

Development of an automatic sampling device for the continuous measurement of atmospheric carbonyls compounds

International Nuclear Information System (INIS)

Perraud, V.

2007-12-01

Two sampling strategies were studied to develop an automatic instrument for the continuous measurement of atmospheric carbonyl compounds. Because of its specificity towards carbonyls compounds, sampling by using a transfer of gaseous phase in a liquid phase associated with a simultaneous chemical derivatization of the trapped compounds was first studied. However, this method do not allow a quantitative sampling of all studied carbonyl compounds, nor a continuous measurement in the field. To overcome the difficulties, a second strategy was investigated: the cryogenic adsorption onto solid adsorbent followed by thermodesorption and a direct analysis by GC/MS. Collection efficiency using different solid adsorbents was found greater than 95% for carbonyl compounds consisting of 1 to 7 carbons. This work is a successful first step towards the realization of the automatic sampling device for a continuous measurement of atmospheric carbonyls compounds. (author)

Organocatalyzed α-Sulfenylation of carbonyl compounds using N-formly/Acyl Sulfenmides

International Nuclear Information System (INIS)

Noh, Hyeon Wan; Lee, Chan; Jang, Hye Young

2017-01-01

α-Sulfenylation of aldehydes and ketones using N-formyl and N-acyl sulfenamides, prepared by Cu-catalyzed aerobic coupling of amides and thiols, was achieved in the presence of cyclic secondary amine⋅HCl catalysts. To obtain various sulfur-functionalized carbonyl compounds, sulfenamides containing aromatic and aliphatic organosulfur were investigated. As carbonyl compounds, cyclic and acyclic ketones, 1,3-dicarbonyl compounds, and aldehydes were investigated, affording the desired α-sulfenylation products in good yields

Organocatalyzed α-Sulfenylation of carbonyl compounds using N-formly/Acyl Sulfenmides

Energy Technology Data Exchange (ETDEWEB)

Noh, Hyeon Wan; Lee, Chan; Jang, Hye Young [Dept. of Energy Systems Research, Ajou University, Suwon (Korea, Republic of)

2017-03-15

α-Sulfenylation of aldehydes and ketones using N-formyl and N-acyl sulfenamides, prepared by Cu-catalyzed aerobic coupling of amides and thiols, was achieved in the presence of cyclic secondary amine⋅HCl catalysts. To obtain various sulfur-functionalized carbonyl compounds, sulfenamides containing aromatic and aliphatic organosulfur were investigated. As carbonyl compounds, cyclic and acyclic ketones, 1,3-dicarbonyl compounds, and aldehydes were investigated, affording the desired α-sulfenylation products in good yields.

Simultaneous detection of low and high molecular weight carbonylated compounds derived from lipid peroxidation by electrospray ionization-tandem mass spectrometry.

Science.gov (United States)

Milic, Ivana; Hoffmann, Ralf; Fedorova, Maria

2013-01-02

Reactive oxygen species (ROS) and other oxidative agents such as free radicals can oxidize polyunsaturated fatty acids (PUFA) as well as PUFA in lipids. The oxidation products can undergo consecutive reactions including oxidative cleavages to yield a chemically diverse group of products, such as lipid peroxidation products (LPP). Among them are aldehydes and ketones ("reactive carbonyls") that are strong electrophiles and thus can readily react with nucleophilic side chains of proteins, which can alter the protein structure, function, cellular distribution, and antigenicity. Here, we report a novel technique to specifically derivatize both low molecular and high molecular weight carbonylated LPP with 7-(diethylamino)coumarin-3-carbohydrazide (CHH) and analyze all compounds by electrospray ionization-mass spectrometry (ESI-MS) in positive ion mode. CHH-derivatized compounds were identified by specific neutral losses or fragment ions. The fragment ion spectra displayed additional signals that allowed unambiguous identification of the lipid, fatty acids, cleavage sites, and oxidative modifications. Oxidation of docosahexaenoic (DHA, 22:6), arachidonic (AA, 20:4), linoleic (LA, 18:2), and oleic acids (OA, 18:1) yielded 69 aliphatic carbonyls, whose structures were all deduced from the tandem mass spectra. When four phosphatidylcholine (PC) vesicles containing the aforementioned unsaturated fatty acids were oxidized, we were able to deduce the structures of 122 carbonylated compounds from the tandem mass spectra of a single shotgun analysis acquired within 15 min. The high sensitivity (LOD ∼ 1 nmol/L for 4-hydroxy-2-nonenal, HNE) and a linear range of more than 3 orders of magnitude (10 nmol/L to 10 μmol/L for HNE) will allow further studies on complex biological samples including plasma.

Convenient Reduction of Carbonyl Compounds to their ...

African Journals Online (AJOL)

NICO

Alcohols and their derivatives occupy an important position in organic synthesis. ... review also reveals that the reduction of carbonyl compounds ..... 1 H.B. Ji and Y.B. She, Green Oxidation and Reduction, China Petrochemi- cal Press, Beijing ...

Reactions of α-phosphorylated carbonyl compounds with amino alcohols

International Nuclear Information System (INIS)

Moskva, V.V.; Sitdikova, T.Sh.; Zykova, T.V.; Alparova, M.V.; Shagvaleev, F.Sh.

1986-01-01

2-Aminoethanol reacts with carbonyl compounds with the formation, depending on the structure of the latter, either of a mixture of azomethines and oxazolidines, or of only azomethines. In the development of investigations on the reactivity of α-phosphorylated carbonyl compounds the authors studied the reactions of a number of amino alcohols with phosphorylated acetaldehyde and acetone. In both cases they observed the formation of compounds of enamine structure, oxazolidines and azomethines were not observed. By means of NMR spectroscopy they established clearly the formation of the E-isomeric products. The 1 H, 31 P, and 13 C NMR spectra were recorded on a WP-80 spectrometer. Chemical shifts of protons and 13 C nuclei are given relative to TMS, and phosphorus nuclei relative to orthophosphoric acid

Olefination of carbonyl compounds: modern and classical methods

Energy Technology Data Exchange (ETDEWEB)

Korotchenko, V N; Nenajdenko, Valentine G; Balenkova, Elizabeth S [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation); Shastin, Aleksey V [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

2004-10-31

The published data on the methods for alkene synthesis by olefination of carbonyl compounds are generalised and systematised. The main attention is given to the use of transition metals and organoelement compounds. The review covers the data on both classical and newly developed methods that are little known to chemists at large.

Olefination of carbonyl compounds: modern and classical methods

Science.gov (United States)

Korotchenko, V. N.; Nenajdenko, Valentine G.; Balenkova, Elizabeth S.; Shastin, Aleksey V.

2004-10-01

The published data on the methods for alkene synthesis by olefination of carbonyl compounds are generalised and systematised. The main attention is given to the use of transition metals and organoelement compounds. The review covers the data on both classical and newly developed methods that are little known to chemists at large.

Spatiotemporal distribution of carbonyl compounds in China.

Science.gov (United States)

Ho, K F; Ho, Steven Sai Hang; Huang, R-J; Dai, W T; Cao, J J; Tian, Linwei; Deng, W J

2015-02-01

A sampling campaign was carried out at nine Chinese cities in 2010/2011. Fifteen monocarbonyls (C# = 1-9) were quantified. Temperature is the rate-determining factor of the summertime carbonyl levels. The carbonyl emissions in winter are mainly driven by the primary anthropogenic sources like automobile. A molar ratio of propionaldehyde to nonaldehyde is a barometer of the impact of atmospheric vegetation emission which suggesting that strong vegetation emissions exist in summer and high propionaldehyde abundance is caused by fossil fuel combustion in winter. Potential health risk assessment of formaldehyde and acetaldehyde was conducted and the highest cumulative risks were observed at Chengdu in summer and Wuhan in winter. Because of the strong photochemical reaction and large amount of anthropogenic emissions, high concentrations of carbonyl compounds were observed in Chengdu. The use of ethanol-blended gasoline in Wuhan is the key reason of acetaldehyde emission and action should be taken to avoid potential health risks. Copyright © 2014 Elsevier Ltd. All rights reserved.

A three-membered ring approach to carbonyl olefination.

Science.gov (United States)

Niyomchon, Supaporn; Oppedisano, Alberto; Aillard, Paul; Maulide, Nuno

2017-10-23

The carbon-carbon double bond, with its diverse and multifaceted reactivity, occupies a prominent position in organic synthesis. Although a variety of simple alkenes are readily available, the mild and chemoselective introduction of a unit of unsaturation into a functionalized organic molecule remains an ongoing area of research, and the olefination of carbonyl compounds is a cornerstone of such approaches. Here we show the direct olefination of hydrazones via the intermediacy of three-membered ring species generated by addition of sulfoxonium ylides, departing from the general dogma of alkenes synthesis from carbonyls. Moreover, the mild reaction conditions and operational simplicity of the transformation render the methodology appealing from a practical point of view.

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Modelling of the partial oxidation of {alpha}, {beta}-unsaturated aldehydes on Mo-V-oxides based catalysts

Energy Technology Data Exchange (ETDEWEB)

Boehnke, H.; Petzoldt, J.C.; Stein, B.; Weimer, C.; Gaube, J.W. [Technische Univ. Darmstadt (Germany). Inst. fuer Chemische Technologie

1998-12-31

A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)

Carbonyl compounds and PAH emissions from CNG heavy-duty engine

International Nuclear Information System (INIS)

Gambino, M.; Cericola, R.; Corbo, P.; Iannaccone, S.

1993-01-01

Previous works carried out in Istituto Motori laboratories have shown that natural gas is a suitable fuel for general means of transportation. This is because of its favorable effects on engine performance and pollutant emissions. The natural gas fueled engine provided the same performance as the diesel engine, met R49 emission standards, and showed very low smoke levels. On the other hand, it is well known that internal combustion engines emit some components that are harmful for human health, such as carbonyl compounds and polycyclic aromatic hydrocarbons (PAH). This paper shows the results of carbonyl compounds and PAH emissions analysis for a heavy-duty Otto cycle engine fueled with natural gas. The engine was tested using the R49 cycle that is used to measure the regulated emissions. The test analysis has been compared with an analysis of a diesel engine, tested under the same conditions. Total PAH emissions from the CNG engine were about three orders of magnitude lower than from the diesel engine. Formaldehyde emission from the CNG engine was about ten times as much as from the diesel engine, while emissions of other carbonyl compounds were comparable

Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety

Directory of Open Access Journals (Sweden)

Silva Jr. Luiz F.

2006-01-01

Full Text Available The rearrangement of beta,gamma-unsaturated esters, such as 2-(3,4-dihydronaphthalen-1-yl-propionic acid ethyl ester, with thallium trinitrate (TTN in acetic acid leads to 3-indan-1-yl-2-methyl-3-oxo-propionic acid ethyl ester in good yield, through a ring contraction reaction. The new indans thus obtained feature a beta-keto ester moiety, which would be useful for further functionalization.

Efficient Conversion of Oximes to the Corresponding Carbonyl Compounds with Tetrabutylammonium Chromate under Aprotic Conditions

International Nuclear Information System (INIS)

Pourali, Ali Reza; Goli, Arezou

2006-01-01

The solubility in several solvents, mildness, simple work-up and absence of side reactions provide advantages of using TBAC in deoximation reactions. This is an efficient and selective method for homogeneous deoximation of structurally different compounds under the moderately acidic and aprotic conditions in high yields. Regeneration of ketones and aldehydes from their oximes has assumed added importance since the discovery of the Barton reaction in which oximes are produced at non-activated hydrocarbon sites. Also, their synthesis from non-carbonyl compounds, such as by nitrosation of an active methylene group, nitrosation of an α-halo carbonyl compound and condensation of a nitro-alkene with an aldehyde provides a valid alternative pathway to carbonyl compounds. Therefore, there has been a continued interest in the effective regeneration of carbonyl compounds from the corresponding oximes especially under mild conditions. Oxidative and reductive methods have been found to show advantages over the classical hydrolytic methods. Although many oxidizing agents have been used, only a limited number of methods are efficient because of the low solubility of these metallic reagents in most organic solvents

Carbonyl compounds in gas and particle phases of mainstream cigarette smoke

International Nuclear Information System (INIS)

Pang, Xiaobing; Lewis, Alastair C.

2011-01-01

Carbonyl compounds (carbonyls) are important constituents of cigarette smoke and some are toxic and may be carcinogenic or mutagenic to humans. In this study carbonyl emissions in the gas and particle phases of mainstream cigarette smoke were assessed by GC-MS with pentafluorophenyl hydrazine (PFPH) derivatization. Seven brands of cigarettes and one brand of cigar common in the UK market and having differing nicotine, tar and carbon monoxide yields were investigated. Sixteen carbonyl components were identified in gaseous emissions and twenty in the particle phase. In the gaseous emissions, acetaldehyde presented as the predominant species, followed by formaldehyde, 2-propenal, and pentanal. In the particulate emissions, 1-hydroxy-2-propanone was the most abundant followed by formaldehyde, benzaldehyde, and 2,5-dimethylbenzaldehyde. Significant differences were found in carbonyl emissions among the brands of cigarettes. The gaseous carbonyl emissions varied in the range of 216-405 μg cigarette -1 (μg cig -1 ) and the particulate carbonyl emissions varied in the range of 23-127 μg cig -1 . Positive correlations were found between the total emission of carbonyls, tar yield and carbon monoxide yield. Similar gas/particle (G/P) partitioning ratios of carbonyls were found among all cigarettes, which implies that G/P partitions of carbonyls in smoke mainly depend on the physical properties of the carbonyls. The gaseous carbonyl emissions were enhanced by 40% to 130% when some of the water, accounting for 8-12% of cigarettes in mass, was removed from the tobacco. Non-filtered cigarettes showed significantly higher carbonyl emissions compared to their filtered equivalents. Carbonyl particulate accounted for 11-19% by mass of total particulate matter from tobacco smoke. The cigar generated 806 μg cig -1 gaseous and 141 μg cig -1 particulate carbonyls, which is 2-4 times greater than the cigarettes. - Highlights: → Carbonyl emission factors in both gas (16 species) and

Carbonyl compounds in gas and particle phases of mainstream cigarette smoke

Energy Technology Data Exchange (ETDEWEB)

Pang, Xiaobing, E-mail: pangxbyuanj@gmail.com [Department of Chemistry, University of York, Heslington, York, YO10 5DD (United Kingdom); Lewis, Alastair C., E-mail: ally.lewis@york.ac.uk [National Centre for Atmospheric Science, University of York, Heslington, York, YO10 5DD (United Kingdom)

2011-11-01

Carbonyl compounds (carbonyls) are important constituents of cigarette smoke and some are toxic and may be carcinogenic or mutagenic to humans. In this study carbonyl emissions in the gas and particle phases of mainstream cigarette smoke were assessed by GC-MS with pentafluorophenyl hydrazine (PFPH) derivatization. Seven brands of cigarettes and one brand of cigar common in the UK market and having differing nicotine, tar and carbon monoxide yields were investigated. Sixteen carbonyl components were identified in gaseous emissions and twenty in the particle phase. In the gaseous emissions, acetaldehyde presented as the predominant species, followed by formaldehyde, 2-propenal, and pentanal. In the particulate emissions, 1-hydroxy-2-propanone was the most abundant followed by formaldehyde, benzaldehyde, and 2,5-dimethylbenzaldehyde. Significant differences were found in carbonyl emissions among the brands of cigarettes. The gaseous carbonyl emissions varied in the range of 216-405 {mu}g cigarette{sup -1} ({mu}g cig{sup -1}) and the particulate carbonyl emissions varied in the range of 23-127 {mu}g cig{sup -1}. Positive correlations were found between the total emission of carbonyls, tar yield and carbon monoxide yield. Similar gas/particle (G/P) partitioning ratios of carbonyls were found among all cigarettes, which implies that G/P partitions of carbonyls in smoke mainly depend on the physical properties of the carbonyls. The gaseous carbonyl emissions were enhanced by 40% to 130% when some of the water, accounting for 8-12% of cigarettes in mass, was removed from the tobacco. Non-filtered cigarettes showed significantly higher carbonyl emissions compared to their filtered equivalents. Carbonyl particulate accounted for 11-19% by mass of total particulate matter from tobacco smoke. The cigar generated 806 {mu}g cig{sup -1} gaseous and 141 {mu}g cig{sup -1} particulate carbonyls, which is 2-4 times greater than the cigarettes. - Highlights: {yields} Carbonyl

cyclo-addition reaction of triplet carbonyl compounds to substituted ...

Indian Academy of Sciences (India)

Unknown

cited state energy of the olefin must be higher than that of the ketone so that ... the first singlet and triplet1,3 (n, π*) excited state of the carbonyl compounds.3,4 ... of the oxetane via carbon–carbon and carbon–oxygen attacks. They found the ...

Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones

Czech Academy of Sciences Publication Activity Database

Václavík, Jiří; Chernykh, Yana; Jurásek, Bronislav; Beier, Petr

2015-01-01

Roč. 169, Jan (2015), s. 24-31 ISSN 0022-1139 R&D Projects: GA ČR GAP207/11/0421 Grant - others:GA MŠk(CZ) ED3.2.00/08.0144; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : fluorine * tetrafluoroethylation * sulfones * nucleophilic addition * carbonyl compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.213, year: 2015

Copper-catalyzed oxidative desulfurization-oxygenation of thiocarbonyl compounds using molecular oxygen: an efficient method for the preparation of oxygen isotopically labeled carbonyl compounds.

Science.gov (United States)

Shibahara, Fumitoshi; Suenami, Aiko; Yoshida, Atsunori; Murai, Toshiaki

2007-06-21

A novel copper-catalyzed oxidative desulfurization reaction of thiocarbonyl compounds, using molecular oxygen as an oxidant and leading to formation of carbonyl compounds, has been developed, and the utility of the process is demonstrated by its application to the preparation of a carbonyl-18O labeled sialic acid derivative.

Characterisation and optimisation of a method for the detection and quantification of atmospherically relevant carbonyl compounds in aqueous medium

Science.gov (United States)

Rodigast, M.; Mutzel, A.; Iinuma, Y.; Haferkorn, S.; Herrmann, H.

2015-01-01

Carbonyl compounds are ubiquitous in the atmosphere and either emitted primarily from anthropogenic and biogenic sources or they are produced secondarily from the oxidation of volatile organic compounds (VOC). Despite a number of studies about the quantification of carbonyl compounds a comprehensive description of optimised methods is scarce for the quantification of atmospherically relevant carbonyl compounds. Thus a method was systematically characterised and improved to quantify carbonyl compounds. Quantification with the present method can be carried out for each carbonyl compound sampled in the aqueous phase regardless of their source. The method optimisation was conducted for seven atmospherically relevant carbonyl compounds including acrolein, benzaldehyde, glyoxal, methyl glyoxal, methacrolein, methyl vinyl ketone and 2,3-butanedione. O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was used as derivatisation reagent and the formed oximes were detected by gas chromatography/mass spectrometry (GC/MS). The main advantage of the improved method presented in this study is the low detection limit in the range of 0.01 and 0.17 μmol L-1 depending on carbonyl compounds. Furthermore best results were found for extraction with dichloromethane for 30 min followed by derivatisation with PFBHA for 24 h with 0.43 mg mL-1 PFBHA at a pH value of 3. The optimised method was evaluated in the present study by the OH radical initiated oxidation of 3-methylbutanone in the aqueous phase. Methyl glyoxal and 2,3-butanedione were found to be oxidation products in the samples with a yield of 2% for methyl glyoxal and 14% for 2,3-butanedione.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in Caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.J.M.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, van P.J.; Cnubben, N.H.P.

2007-01-01

Curcumin, an alpha,beta-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional H-1 NMR

Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

Energy Technology Data Exchange (ETDEWEB)

Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

2014-09-15

We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

International Nuclear Information System (INIS)

Takeda, Kazuhiko; Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi; Nakatani, Nobutake; Sakugawa, Hiroshi

2014-01-01

We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area

A method for hydrogenating and carbonylizing unsaturated compounds in the presence of catalysts based on phosphine and metal complexes

Energy Technology Data Exchange (ETDEWEB)

Briggs, J C; Dyer, G

1982-12-22

The hydrogenation of unsaturated organic compounds or the attachment to them of CO is accomplished with contact with a synthesis gas in the presence of a stereospecific catalyst (Kt), a compound of a metal of the platinum group (preferably Rhodium, but also Platinum, Palladium, Ruthenium or Iridium) and an asymmetrical bis-phosphine of the formula A-(CH2)n-B, where A and B are phosphine groups. R2P and R'2P or RRhP, where R is an aryl radical, R' is aralkyl, alcarylic or alkyl radical, n = 1 to 10, or an asymmetrical monophosphine of the formula R2-R'P. The complex compound also includes Hydrogen, CO and (or) halogen (preferably Chlorine) as ligands. The physical properties of the obtained complex compounds of the carbonylchlorbisphosphines or Rh are presented: trans-(RhC1-(CO)(Ph2P(CH2)6PPh2))2; trans-(RhC1(CO)(C2H5PhP-(CH2)6PPh2))2; trans-(RhC1(CO)(cycloC6H11PhP(CH2)6-PPh2))2; trans-(RhC1(CO)(C2H5PhP(CH2)4PPh2)2; trans-(RhC1(CO)(C2H5PhP(Ch2))2 and PhC1(CO)4(p-C6H4CH2)2P(Ch2)6PPh2). The isolated complexes are light yellow crystalline substances.

Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

KAUST Repository

Guan, Xiao-Yu

2014-02-07

A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

KAUST Repository

Guan, Xiao-Yu; Al-Misba'a, Zahra; Huang, Kuo-Wei

2014-01-01

A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

Volatile organic compounds in the unsaturated zone from radioactive wastes

Science.gov (United States)

Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

2012-01-01

Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyltrimethylsilane and triphenylphosphine

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Fei Wang

2014-02-01

Full Text Available Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods.Results: The combination of (chlorodifluoromethyltrimethylsilane (TMSCF2Cl and triphenylphosphine (PPh3 can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyltrimethylsilane (TMSCF2Br and (trifluoromethyltrimethylsilane (TMSCF3 in this reaction.Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.

Characterization of Carbonyl Compounds in the Ambient Air of an Industrial City in Korea

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Sung-Ok Baek

2011-01-01

Full Text Available The purpose of this study was to characterize spatial and temporal variations of carbonyl compounds in Gumi city, where a number of large electronic-industrial complexes are located. Carbonyl samples were collected at five sites in the Gumi area: three industrial, one commercial, and one residential area. Sampling was carried out throughout a year from December 2003 to November 2004. At one industrial site, samples were taken every six days, while those of the other sites were for seven consecutive days in every season. Each sample was collected for 150 minutes and at intervals of three times a day (morning, afternoon, and evening. A total of 476 samples were analyzed to determine 15 carbonyl compounds by the USEPA TO-11A (DNPH-cartridge/HPLC method. In general, acetaldehyde appeared to be the most abundant compound, followed by formaldehyde, and acetone+acrolein. Mean concentrations of acetaldehyde were two to three times higher in the industrial sites than in the other sites, with its maximum of 77.7 ppb. In contrast, ambient levels of formaldehyde did not show any significant difference between the industrial and non-industrial groups. Its concentrations peaked in summer probably due to the enhanced volatilization and photochemical reactivity. These results indicate significant emission sources of acetaldehyde in the Gumi industrial complexes. Mean concentrations of organic solvents (such as acetone+acrolein and methyl ethyl ketone were also significantly high in industrial areas. In conclusion, major sources of carbonyl compounds, including acetaldehyde, are strongly associated with industrial activities in the Gumi city area.

Determination of Carbonyl Compounds in Cigarette Mainstream Smoke. The CORESTA 2010 Collaborative Study and Recommended Method

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Intorp M

2014-12-01

Full Text Available A recommended method has been developed and published by CORESTA, applicable to the quantification of selected carbonyl compounds (acetaldehyde, formaldehyde, acetone, acrolein, methyl ethyl ketone, crotonaldehyde, propionaldehyde and butyraldehyde in cigarette mainstream smoke. The method involved smoke collection in impinger traps, derivatisation of carbonyls with 2,4-dinitrophenylhydrazine (DNPH, separation of carbonyl hydrazones by reversed phase high performance liquid chromatography and detection by ultra violet or diode array.

Growth of Synthrophomonas wolfei on unsaturated short chain fatty acids

Energy Technology Data Exchange (ETDEWEB)

Amos, D.A.; McInerney, M.J. (Univ. of Oklahoma, Norman, OK (United States))

1990-01-01

The anaerobic fatty acid-degrading syntrophic bacterium, Syntrophomonas wolfei, was grown in pure culture with either trans-2-pentenoate, trans-2-hexenoate, trans-3-hexenoate, or trans, trans-2, 4-hexadienoate as the substrate. Trans-2-pentenoate was fermented to acetate, propionate, butyrate, and valerate. Acetate, butyrate and hexanoate were produced from the six-carbon mono- and di-unsaturated acids. Propionate was also product from the trans, trans-2, 4-hexadienoate which suggested that compound was degraded by another pathway in addition to [beta]-oxidation. The transient production of trans-2-hexenoate from trans-3-hexenoate suggested that the position of the double bound shifted from carbon-3 to carbon-2 prior to [beta]-oxidation. The specific growth rate decreased with increasing carbon length and degree of unsaturation. Molar growth yields ranged from 8.4 to 17.5 mg (dry wt.) per mmol and suggested that energy was conserved not only from substrate-level phosphorylation, but also from the reduction of unsaturated substrate.

Acrolein with an alpha, beta-unsaturated Carbonyl Group Inhibits LPS-induced Homodimerization of Toll-like Receptor 4

Science.gov (United States)

Acrolein is a highly electrophilic a,ß-unsaturated aldehyde present in a number of environmental sources, especially cigarette smoke. It reacts strongly with the thiol groups of cysteine residues by Michael addition and has been reported to inhibit nuclear factor-kB (NF-kB) activation by lipopolysac...

Determination of carbonyl compounds in air by HPLC

International Nuclear Information System (INIS)

Garcia, S.; Perez, R.M.; Campos, A.; Gonzalez, D.

1995-09-01

A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetone+acrolein. Three different types of samples (rural, urban, petrol emission) were successfully analyzed

Characterisation and optimisation of a sample preparation method for the detection and quantification of atmospherically relevant carbonyl compounds in aqueous medium

Science.gov (United States)

Rodigast, M.; Mutzel, A.; Iinuma, Y.; Haferkorn, S.; Herrmann, H.

2015-06-01

Carbonyl compounds are ubiquitous in the atmosphere and either emitted primarily from anthropogenic and biogenic sources or they are produced secondarily from the oxidation of volatile organic compounds. Despite a number of studies about the quantification of carbonyl compounds a comprehensive description of optimised methods is scarce for the quantification of atmospherically relevant carbonyl compounds. The method optimisation was conducted for seven atmospherically relevant carbonyl compounds including acrolein, benzaldehyde, glyoxal, methyl glyoxal, methacrolein, methyl vinyl ketone and 2,3-butanedione. O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was used as derivatisation reagent and the formed oximes were detected by gas chromatography/mass spectrometry (GC/MS). With the present method quantification can be carried out for each carbonyl compound originating from fog, cloud and rain or sampled from the gas- and particle phase in water. Detection limits between 0.01 and 0.17 μmol L-1 were found, depending on carbonyl compounds. Furthermore, best results were found for the derivatisation with a PFBHA concentration of 0.43 mg mL-1 for 24 h followed by a subsequent extraction with dichloromethane for 30 min at pH = 1. The optimised method was evaluated in the present study by the OH radical initiated oxidation of 3-methylbutanone in the aqueous phase. Methyl glyoxal and 2,3-butanedione were found to be oxidation products in the samples with a yield of 2% for methyl glyoxal and 14% for 2,3-butanedione after a reaction time of 5 h.

Organosulfate Formation through the Heterogeneous Reaction of Sulfur Dioxide with Unsaturated Compounds

Science.gov (United States)

George, C.; Passananti, M.; Kong, L.; Shang, J.; Perrier, S.; Jianmin, C.; Donaldson, D. J.

2016-12-01

The atmospheric formation of organosulfur derivatives through reaction with SO2 is generally mediated by oxidants such as O3, OH; recently we have proposed a direct reaction between SO2 and unsaturated compounds as another possible pathway for organosulfate formation in the troposphere. For the first time it was shown recently that a heterogeneous reaction between SO2 and oleic acid (OA; an unsaturated fatty acid) takes place and leads efficiently to the formation of organosulfur products. Here, we demonstrate that this reaction proceeds on various unsaturated compounds, and may therefore have a general environmental impact. We used different experimental strategies i.e., a coated flow tube (CFT), an aerosol flow tube (AFT) and a DRIFT (diffuse reflectance infrared Fourier transform) cell. The reaction products were analyzed by means of liquid chromatography coupled to a high resolution mass spectrometer (LC-HR-MS). We report indeed that SO2 reacts with large variety of C=C unsaturations and that even in the presence of ozone, SO2 reacts with OA leading to organosulfur products. A strong enhancement in product formation is observed under actinic illumination, increases the atmospheric significance of this chemical pathway. This is probably due to the chromophoric nature of the SO2 adduct with C=C bonds, and means that the contribution of this direct addition of SO2 could be in excess of 5%. The detection in atmospheric aerosols of organosulfur compounds with the same chemical formulae as the products identified here seems to confirm the importance of this reaction in the atmosphere.

Determination of carbonyl compounds in air by HPLC

International Nuclear Information System (INIS)

Garcia, S.; Perez, R.M.; Campos, A.; Gonzalez, D.

1995-01-01

A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak Cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetoacetonitrile. Three different types of samples (rural, urban, petrol emission) were successfully analyzed. (Author) 12 refs

Ruthenium(II) carbonyl compounds with the 4'-chloro-2,2':6',2''-terpyridine ligand.

Science.gov (United States)

Tatikonda, Rajendhraprasad; Haukka, Matti

2017-04-01

Two ruthenium carbonyl complexes with the 4'-chloro-2,2':6',2''-terpyridine ligand (tpy-Cl, C 15 H 10 ClN 3 ), i.e. [RuCl(tpy-Cl)(CO) 2 ][RuCl 3 (CO) 3 ] (I) [systematic name: cis -di-carbonyl-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 3 N )ruthenium(II) fac -tricarbonyltri-chlorido-ruthenate(II)], and [RuCl 2 (tpy-Cl)(CO) 2 ] (II) [ cis -dicarbonyl- trans -di-chlorido(4'-chloro-2,2':6',2''-terpyridine-κ 2 N 1 , N 1' )ruthenium(II)], were synthesized and characterized by single-crystal X-ray diffraction. The Ru II atoms in both centrosymmetric structures (I) and (II) display similar, slightly distorted octa-hedral coordination spheres. The coordination sphere in the complex cation in compound (I) is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octa-hedral [Ru(CO) 3 Cl 3 ] - counter-anion. In the neutral compound (II), the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the Ru II atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I) and (II), weak C-H⋯Cl inter-actions are observed.

Arylation of beta, gamma-unsaturated lactones by a Heck-Matsuda reaction: an unexpected route to aryldiazene butenolides and pyridazinones

Energy Technology Data Exchange (ETDEWEB)

Taylor, Jason G.; Correia, Carlos Roque D., E-mail: roque@iqm.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

2010-07-01

The palladium catalysed coupling of aryldiazonium salts with {beta}-{gamma}-unsaturated lactones under basic conditions has been investigated. Both (3H)-furanone and {alpha}-angelicalactone were evaluated as substrates in the Heck Matsuda reaction but both failed to afford the desired arylated butenolides. Under basic conditions, {beta}-{gamma}-unsaturated lactones generate highly nucleophilic enolates that preferentially undergo azo coupling reactions with arenediazonium salts to afford aryldiazene butenolides. The electronic and steric effect of the substituents on the aryldiazonium salt in the azo coupling reaction is described. Aryldiazene-lactone derivatives were obtained in good yields from a highly facile and straightforward procedure. An aminoisomaleimide was formed from (3H)-furanone and cyclized to the corresponding pyridazinones in modest yield. (author)

Stereo-controlled synthesis of polyheterocycles via the diene-transmissive hetero-Diels-Alder reaction of β,γ-unsaturated α-keto esters.

Science.gov (United States)

Otani, Takashi; Tamai, Yumiko; Seki, Kazunori; Kikuchi, Tomohiro; Miyazawa, Taiichiro; Saito, Takao

2015-06-07

We describe the stereoselective synthesis of polyring-fused heterocyclic compounds based on diene-transmissive hetero-Diels-Alder reactions utilizing β,γ-unsaturated α-keto esters. This protocol involves the initial endo- or exo-selective Diels-Alder (DA) reactions with electron-rich dienophiles, methylenation of the ester carbonyl groups with the Tebbe reagent, and a stereoselective second DA reaction with electron-deficient dienophiles. The use of enantioselective DA reactions in the initial reaction enables access to chiral polyring-fused heterocyclic compounds with multiple chiral centres.

Rapid Determination of Six Low Molecular Carbonyl Compounds in Tobacco Smoke by the APCI-MS/MS Coupled to Data Mining

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Wuduo Zhao

2017-01-01

Full Text Available A simple method was established for the rapid determination of low molecular carbonyl compounds by the combination of atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS and data mining. The ionization was carried out in positive mode, and six low molecular carbonyl compounds of acrolein, acetone, propionaldehyde, crotonaldehyde, butanone, and butyraldehyde were analyzed by both full scan mode and daughter scan mode. To overcome the quantitative difficulties from isomer of acetone/propionaldehyde and butanone/butyraldehyde, the quantitation procedure was performed with the characteristic ion of [CH3O]+ under CID energy of 5 and 15 eV. Subsequently, the established method was successfully applied to analysis of six low molecular carbonyl compounds in tobacco smoke with analytical period less than four minutes. The contents of acrolein, acetone, propionaldehyde, crotonaldehyde, butanone, and butyraldehyde for a cigarette were about 63±5.8, 325±82, 55±9.7, 11±1.4, 67±5.9, and 12±1.8 μg/cig, respectively. The experimental results indicated that the established method had the potential application in rapid determination of low molecular carbonyl compounds.

Interactions of [alpha,beta]-unsaturated carbonyl compounds with the glutathione-related biotransformation system

NARCIS (Netherlands)

Iersel, van M.L.P.S.

1998-01-01

Introduction
Modulation of glutathione-related biotransformation steps may play a role in important phenomena as anticarcinogenicity and multidrug resistance. Glutathione-related biotransformation comprises three main aspects i.e. glutathione, the

Nicotine, aerosol particles, carbonyls and volatile organic compounds in tobacco- and menthol-flavored e-cigarettes.

Science.gov (United States)

Lee, Mi-Sun; LeBouf, Ryan F; Son, Youn-Suk; Koutrakis, Petros; Christiani, David C

2017-04-27

We aimed to assess the content of electronic cigarette (EC) emissions for five groups of potentially toxic compounds that are known to be present in tobacco smoke: nicotine, particles, carbonyls, volatile organic compounds (VOCs), and trace elements by flavor and puffing time. We used ECs containing a common nicotine strength (1.8%) and the most popular flavors, tobacco and menthol. An automatic multiple smoking machine was used to generate EC aerosols under controlled conditions. Using a dilution chamber, we targeted nicotine concentrations similar to that of exposure in a general indoor environment. The selected toxic compounds were extracted from EC aerosols into a solid or liquid phase and analyzed with chromatographic and spectroscopic methods. We found that EC aerosols contained toxic compounds including nicotine, fine and nanoparticles, carbonyls, and some toxic VOCs such as benzene and toluene. Higher mass and number concentrations of aerosol particles were generated from tobacco-flavored ECs than from menthol-flavored ECs. We found that diluted machine-generated EC aerosols contain some pollutants. These findings are limited by the small number of ECs tested and the conditions of testing. More comprehensive research on EC exposure extending to more brands and flavor compounds is warranted.

Biodiesel emissions profile in modern diesel vehicles. Part 2: Effect of biodiesel origin on carbonyl, PAH, nitro-PAH and oxy-PAH emissions.

Science.gov (United States)

Karavalakis, Georgios; Boutsika, Vasiliki; Stournas, Stamoulis; Bakeas, Evangelos

2011-01-15

In the present study, the effects of different biodiesel blends on the unregulated emissions of a Euro 4 compliant passenger car were examined. Two fresh and two oxidized biodiesel fuels of different source materials were blended with an ultra low sulphur automotive diesel fuel at proportions of 10, 20, and 30% v/v. Emission measurements were conducted on a chassis dynamometer with a constant volume sampling (CVS) technique, over the New European Driving Cycle (NEDC) and the Artemis driving cycles. The experimental results revealed that the addition of biodiesel led to important increases in most carbonyl compounds. Sharp increases were observed with the use of the oxidized biodiesel blends, especially those prepared from used frying oil methyl esters. Similar to carbonyl emissions, most PAH compounds increased with the addition of the oxidized biodiesel blends. It can be assumed that the presence of polymerization products and cyclic acids, along with the degree of unsaturation were the main factors that influenced carbonyl and PAH emissions profile. Copyright © 2010 Elsevier B.V. All rights reserved.

SiO2@FeSO4 nano composite: A recoverable nano-catalyst for eco-friendly synthesis oximes of carbonyl compounds

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Mostafa Karimkoshteh

2016-01-01

Full Text Available Various aldoximes and ketoximes synthesis of corresponding aldehydes and ketones in the presence of SiO2@FeSO4 nano composite as recoverable nano catalyst and NH2OH·HCl. The SiO2@FeSO4 nano composite system was carried out between 10 to 15 min in oil bath (70-80 °C under solvent-free condition in excellent yields in addition this protocol can be used for industrial scales. This method offers some advantages in term of clean reaction conditions, easy work-up procedure, short reaction time, applied to convert α-diketones to α-diketoximes (as longer than other carbonyl compounds, α,β-unsaturated aldehydes and ketones to corresponding oximes and suppression of any side product. So we think that NH2OH•HCl/SiO2@FeSO4 nano composite system could be considered a new and useful addition to the present methodologies in this area. Structure of products and nano composite elucidation was carried out by 1H NMR, 13C NMR, FT-IR, scanning electron microscopy (SEM.

Effects of low concentration biodiesel blends application on modern passenger cars. Part 2: Impact on carbonyl compound emissions

International Nuclear Information System (INIS)

Fontaras, Georgios; Karavalakis, Georgios; Kousoulidou, Marina; Ntziachristos, Leonidas; Bakeas, Evangelos; Stournas, Stamoulis; Samaras, Zissis

2010-01-01

Today in most European member states diesel contains up to 5% vol biodiesel. Since blending is expected to increase to 10% vol, the question arises, how this higher mixing ratio will affect tailpipe emissions particularly those linked to adverse health effects. This paper focuses on the impact of biodiesel on carbonyl compound emissions, attempting also to identify possible relationship between biodiesel feedstock and emissions. The blends were produced from five different feedstocks, commonly used in Europe. Measurements were conducted on a Euro 3 common-rail passenger car over various driving cycles. Results indicate that generally the use of biodiesel at low concentrations has a minor effect on carbonyl compound emissions. However, certain biodiesels resulted in significant increases while others led to decreases. Biodiesels associated with increases were those derived from rapeseed oil (approx. 200%) and palm oil (approx. 180%), with the highest average increases observed at formaldehyde and acroleine/acetone. - Biodiesel application, may increase the levels of certain pollutants such as carbonyl compounds which are associated with both environmental and health risks.

Characteristics of carbonyl compounds in public vehicles of Beijing city: Concentrations, sources, and personal exposures

Science.gov (United States)

Pang, Xiaobing; Mu, Yujing

The characteristics of carbonyl compounds (carbonyls) including concentrations, major sources, and personal exposure were investigated for 29 vehicles including taxi, bus and subway in Beijing. It was found that the taxis (Xiali, TA) and buses (Huanghe, BA) fueled by gasoline with longer service years had the higher indoor carbonyl levels (178±42.7 and 188±31.6 μg m -3) while subways energized by electricity without exhaust and the jingwa buses (BB) driven in the suburb had the lower levels with total concentrations of 98.5±26.3 and 92.1±20.3 μg m -3, respectively. Outdoor carbonyls of taxi cars and buses were nearly at the same level with their total concentrations varying from 80 to 110 μg m -3. The level of outdoor subways carbonyls was equal with the ambient air levels. Exhaust leakage, indoor material emissions, photochemical formation, and infiltration of outdoor air were considered to be the major sources to in-vehicle carbonyls. Personal exposures and cancer risk to formaldehyde and acetaldehyde were calculated for professional bus and taxi drivers, respectively. Taxi drivers had the highest cancer risk with personal exposure to formaldehyde and acetaldehyde of 212 and 243 μg day -1, respectively. The public concern should pay considerable attention to professional drivers' health.

Investigation of carbonyl compound sources at a rural site in the Yangtze River Delta region of China.

Science.gov (United States)

Wang, Ming; Chen, Wentai; Shao, Min; Lu, Sihua; Zeng, Limin; Hu, Min

2015-02-01

Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons, and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25th to 27th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th-8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene (T/B) during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was 5.8 ppb/ppb, significantly higher than the values of 0.2-1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and 0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better. Copyright © 2014. Published by Elsevier B.V.

Organocatalyzed Asymmetric α-Oxidation, α-Aminoxylation and α-Amination of Carbonyl Compounds

Directory of Open Access Journals (Sweden)

Worawan Bhanthumnavin

2010-02-01

Full Text Available Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects and synthetic applications of α-oxidation, hydroxylation, aminoxylation, amination, hydrazination, hydroxyamination and related α-heteroatom functionalization of aldehydes, ketones and related active methylene compounds published during 2005–2009.

Organocatalyzed Asymmetric α-Oxidation, α-Aminoxylation and α-Amination of Carbonyl Compounds

OpenAIRE

Worawan Bhanthumnavin; Tirayut Vilaivan

2010-01-01

Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects ...

TRPA1-dependent reversible opening of tight junction by natural compounds with an α,β-unsaturated moiety and capsaicin.

Science.gov (United States)

Kanda, Yusuke; Yamasaki, Youhei; Sasaki-Yamaguchi, Yoshie; Ida-Koga, Noriko; Kamisuki, Shinji; Sugawara, Fumio; Nagumo, Yoko; Usui, Takeo

2018-02-02

The delivery of hydrophilic macromolecules runs into difficulties such as penetration of the cell membrane lipid bilayer. Our prior experiment demonstrated that capsaicin induces the reversible opening of tight junctions (TJs) and enhances the delivery of hydrophilic macromolecules through a paracellular route. Herein, we screened paracellular permeability enhancers other than capsaicin. As TJ opening by capsaicin is associated with Ca 2+ influx, we first screened the compounds that induce Ca 2+ influx in layered MDCK II cells, and then we determined the compounds' abilities to open TJs. Our results identified several natural compounds with α,β-unsaturated moiety. A structure-activity relationship (SAR) analysis and the results of pretreatment with reducing reagent DTT suggested the importance of α,β-unsaturated moiety. We also examined the underlying mechanisms, and our findings suggest that the actin reorganization seen in capsaicin treatment is important for the reversibility of TJ opening. Furthermore, our analyses revealed that TRPA1 is involved in the Ca 2+ influx and TJ permeability increase not only by an α,β-unsaturated compound but also by capsaicin. Our results indicate that the α,β-unsaturated moiety can be a potent pharmacophore for TJ opening.

FEMA expert panel review of p-mentha-1,8-dien-7-al genotoxicity testing results

NARCIS (Netherlands)

Cohen, Samuel M.; Fukushima, Shoji; Gooderham, Nigel J.; Guengerich, F.P.; Hecht, Stephen S.; Rietjens, Ivonne M.C.M.; Smith, Robert L.; Bastaki, Maria; Harman, Christie L.; McGowen, Margaret M.; Taylor, Sean V.

2016-01-01

p-Mentha-1,8-dien-7-al is a naturally occurring cyclic alpha,beta-unsaturated aldehyde that is used as a flavoring substance throughout the world. Due to the chemical structure and the potential DNA reactivity of the alpha,beta-unsaturated carbonyl moiety, a battery of genotoxicity assays was

Magnetically Recoverable Supported Ruthenium Catalyst for Hydrogenation of Alkynes and Transfer Hydrogenation of Carbonyl Compounds

Science.gov (United States)

A ruthenium (Ru) catalyst supported on magnetic nanoparticles (NiFe2O4) has been successfully synthesized and used for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The cata...

Ligand intermediates in metal-catalyzed reactions; Annual technical report, August 1, 1992--August 1, 1993

Energy Technology Data Exchange (ETDEWEB)

Gladysz, J.A.

1993-08-10

Achievements are reported for the following 4 areas: {pi}/{sigma} equillibria in aldehyde and ketone complexes; thermodynamic ligand binding affinities ({alpha},{beta} unsaturated organic carbonyl compounds); (a new form of coordinated carbon) an unsupported C{sub 3} chain that spans two different transition metals; and (a new form of coordinated carbon) an C{sub 3} chain that is anchored by a metal on each end and spanned by a third.

Synthesis of silyl iron hydride via Si-H activation and its dual catalytic application in the hydrosilylation of carbonyl compounds and dehydration of benzamides.

Science.gov (United States)

Ren, Shishuai; Xie, Shangqing; Zheng, Tingting; Wang, Yangyang; Xu, Shilu; Xue, Benjing; Li, Xiaoyan; Sun, Hongjian; Fuhr, Olaf; Fenske, Dieter

2018-03-28

The hydrido silyl iron complex (o-Ph 2 PC 6 H 4 SiMe 2 )Fe(PMe 3 ) 3 H (2) was obtained via the activation of the Si-H bond of the bidentate silyl ligand o-Ph 2 P(C 6 H 4 )SiMe 2 H (1) by Fe(PMe 3 ) 4 . 2 showed good to excellent catalytic activity in both the reduction of aldehydes/ketones and the dehydration of benzamide. In addition, with complex 2 as a catalyst, α,β-unsaturated carbonyls could be selectively reduced to the corresponding α,β-unsaturated alcohols. The mechanisms of the formation of 2 and the catalytic dehydration process are proposed and partly experimentally verified.

Copper-catalyzed 1,2-addition of α-carbonyl iodides to alkynes.

Science.gov (United States)

Xu, Tao; Hu, Xile

2015-01-19

β,γ-Unsaturated ketones are an important class of organic molecules. Herein, copper catalysis has been developed for the synthesis of β-γ-unsaturated ketones through 1,2-addition of α-carbonyl iodides to alkynes. The reactions exhibit wide substrate scope and high functional group tolerance. The reaction products are versatile synthetic intermediates to complex small molecules. The method was applied for the formal synthesis of (±)-trichostatin A, a histone deacetylase inhibitor. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbonyl Activation by Borane Lewis Acid Complexation: Transition States of H2 Splitting at the Activated Carbonyl Carbon Atom in a Lewis Basic Solvent and the Proton-Transfer Dynamics of the Boroalkoxide Intermediate.

Science.gov (United States)

Heshmat, Mojgan; Privalov, Timofei

2017-07-06

By using transition-state (TS) calculations, we examined how Lewis acid (LA) complexation activates carbonyl compounds in the context of hydrogenation of carbonyl compounds by H 2 in Lewis basic (ethereal) solvents containing borane LAs of the type (C 6 F 5 ) 3 B. According to our calculations, LA complexation does not activate a ketone sufficiently enough for the direct addition of H 2 to the O=C unsaturated bond; but, calculations indicate a possibly facile heterolytic cleavage of H 2 at the activated and thus sufficiently Lewis acidic carbonyl carbon atom with the assistance of the Lewis basic solvent (i.e., 1,4-dioxane or THF). For the solvent-assisted H 2 splitting at the carbonyl carbon atom of (C 6 F 5 ) 3 B adducts with different ketones, a number of TSs are computed and the obtained results are related to insights from experiment. By using the Born-Oppenheimer molecular dynamics with the DFT for electronic structure calculations, the evolution of the (C 6 F 5 ) 3 B-alkoxide ionic intermediate and the proton transfer to the alkoxide oxygen atom were investigated. The results indicate a plausible hydrogenation mechanism with a LA, that is, (C 6 F 5 ) 3 B, as a catalyst, namely, 1) the step of H 2 cleavage that involves a Lewis basic solvent molecule plus the carbonyl carbon atom of thermodynamically stable and experimentally identifiable (C 6 F 5 ) 3 B-ketone adducts in which (C 6 F 5 ) 3 B is the "Lewis acid promoter", 2) the transfer of the solvent-bound proton to the oxygen atom of the (C 6 F 5 ) 3 B-alkoxide intermediate giving the (C 6 F 5 ) 3 B-alcohol adduct, and 3) the S N 2-style displacement of the alcohol by a ketone or a Lewis basic solvent molecule. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Compostos carbonílicos atmosféricos: fontes, reatividade, níveis de concentração e efeitos toxicológicos Atmospheric carbonyl compounds: sources, reactivity, concentration levels and toxicologic effects

Directory of Open Access Journals (Sweden)

Marta Valéria Almeida Santana de Andrade

2002-12-01

Full Text Available In the last three decades carbonyl compounds, aldehydes and ketones, have received a great deal of attention due to their strong influence on photochemical smog formation and their recognized adverse human health effects. Carbonyl compounds are directly emitted into the atmosphere by combustion sources and also produced from photochemical oxidation of hydrocarbons and other organic compounds. In this paper it is presented a general overview about the carbonyl compounds sources, reactivity, concentration levels and toxicological effects.

Chemical Resistance of Ornamental Compound Stone Produced with Marble Waste and Unsaturated Polyester

Science.gov (United States)

Ribeiro, Carlos E. Gomes; Rodriguez, Rubén J. Sánchez; Vieira, Carlos M. Fontes

Ornamental compound stone are produced by industry for decades, however, few published studies describe these materials. Brazil has many deposits of stone wastes and a big potential to produce these materials. This work aims to evaluate the chemical resistance of ornamental compound stones produced with marble waste and unsaturated polyester. An adaptation of Annex H of ABNT NBR 13818:97 standard, with reagents commonly used in household products, was used. The results were compared with those obtained for natural stone used in composite production.

Photocatalytic degradation of mixed gaseous carbonyl compounds at low level on adsorptive TiO2/SiO2 photocatalyst using a fluidized bed reactor.

Science.gov (United States)

Zhang, Maolin; An, Taicheng; Fu, Jiamo; Sheng, Guoying; Wang, Xinming; Hu, Xiaohong; Ding, Xuejun

2006-06-01

An adsorptive silica-supported titania photocatalyst TiO(2)/SiO(2) was prepared by using nanosized titania (anatase) immobilized on silica gel by the sol-gel technique with the titanium tetra isopropoxide as the main raw material and acetic acid as the acid catalyst. Meanwhile the structure and properties of the TiO(2)/SiO(2) photocatalyst were studied by means of many modern analysis techniques such as TEM, XRD, and BET. Gas-solid heterogeneous photocatalytic decomposition of four carbonyl compounds mixture at low concentration levels over ultraviolet irradiated TiO(2)/SiO(2) photocatalyst were carried out with high degradation efficiencies in a coaxial triple-cylinder-type fluidized bed photocatalytic reactor, which provided efficient continuous contact of ultraviolet photons, silica-supported titania photocatalyst, and gaseous reactants. Experimental results showed that the photocatalyst had a high adsorption performance and a good photocatalytic activity for four carbonyl compounds mixture. Some factors influencing the photocatalytic decomposition of the mixed carbonyl compounds, i.e. the gas flowrate, relative humidity, concentration of oxygen, and illumination time, were discussed in detail. It is found that the photocatalytic reaction rate of four carbonyl compounds decreased in this order: propionaldehyde, acetone, acetaldehyde and formaldehyde.

Modifications of proteins by polyunsaturated fatty acid peroxidation products

DEFF Research Database (Denmark)

Refsgaard, Hanne; Tsai, Lin; Stadtman, Earl

2000-01-01

The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(lll)/O-2] depends on the degree of unsaturation of the fatty acid. The fatty acid......-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate fatty acids were oxidized in the presence...... in the formation of protein carbonyls, These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (alpha,beta-unsaturated aldehydes) with lysine residues...

Carbonyl Emissions from Gasoline and Diesel Motor Vehicles

Energy Technology Data Exchange (ETDEWEB)

Destaillats, Hugo; Jakober, Chris A.; Robert, Michael A.; Riddle, Sarah G.; Destaillats, Hugo; Charles, M. Judith; Green, Peter G.; Kleeman, Michael J.

2007-12-01

Carbonyls from gasoline powered light-duty vehicles (LDVs) and heavy-duty diesel powered vehicles (HDDVs) operated on chassis dynamometers were measured using an annular denuder-quartz filter-polyurethane foam sampler with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography-mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery, 4-fluorobenzaldehyde forcarbonyls and 6-fluoro-4-chromanone for>_C8 compounds. Gas- and particle-phase emissions for 39 aliphatic and 20 aromatic carbonyls ranged from 0.1 ? 2000 ?g/L fuel for LDVs and 1.8 - 27000 mu g/L fuel for HDDVs. Gas-phase species accounted for 81-95percent of the total carbonyls from LDVs and 86-88percent from HDDVs. Particulate carbonyls emitted from a HDDV under realistic driving conditions were similar to concentrations measured in a diesel particulate matter (PM) standard reference material. Carbonyls accounted for 19percent of particulate organic carbon (POC) emissions from low-emission LDVs and 37percent of POC emissions from three-way catalyst equipped LDVs. This identifies carbonyls as one of the largest classes of compounds in LDV PM emissions. The carbonyl fraction of HDDV POC was lower, 3.3-3.9percent depending upon operational conditions. Partitioning analysis indicates the carbonyls had not achieved equilibrium between the gas- and particle-phase under the dilution factors of 126-584 used in the current study.

Protein conjugated with aldehydes derived from lipid peroxidation as an independent parameter of the carbonyl stress in the kidney damage

Directory of Open Access Journals (Sweden)

Medina-Navarro Rafael

2011-11-01

Full Text Available Abstract Background One of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins. However, carbonyl groups can be introduced into proteins by non-oxidative mechanisms. Reactive carbonyl compounds have been observed to have increased in patients with renal failure. In the present work we have described a procedure designed as aldehyde capture to calculate the protein carbonyl stress derived solely from lipid peroxidation. Methods Acrolein-albumin adduct was prepared as standard at alkaline pH. Rat liver microsomal membranes and serum samples from patients with diabetic nephropathy were subjected to the aldehyde capture procedure and aldol-protein formation. Before alkalinization and incubation, samples were precipitated and redisolved in 6M guanidine. The absorbances of the samples were read with a spectrophotometer at 266 nm against a blank of guanidine. Results Evidence showed abundance of unsaturated aldehydes derived from lipid peroxidation in rat liver microsomal membranes and in the serum of diabetic patients with advanced chronic kidney disease. Carbonyl protein and aldol-proteins resulted higher in the diabetic nephropathy patients (p Conclusion The aldehyde-protein adduct represents a non oxidative component of carbonyl stress, independent of the direct amino acid oxidation and could constitute a practical and novelty strategy to measure the carbonyl stress derived solely from lipid peroxidation and particularly in diabetic nephropathy patients. In addition, we are in a position to propose an alternative explanation of why alkalinization of urine attenuates rhabdomyolysis-induced renal dysfunction.

Catalytic asymmetric epoxidation of alpha,beta-unsaturated amides: efficient synthesis of beta-aryl alpha-hydroxy amides using a one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process.

Science.gov (United States)

Nemoto, Tetsuhiro; Kakei, Hiroyuki; Gnanadesikan, Vijay; Tosaki, Shin-Ya; Ohshima, Takashi; Shibasaki, Masakatsu

2002-12-11

The catalytic asymmetric epoxidation of alpha,beta-unsaturated amides using Sm-BINOL-Ph3As=O complex was succeeded. Using 5-10 mol % of the asymmetric catalyst, a variety of amides were epoxidized efficiently, yielding the corresponding alpha,beta-epoxy amides in up to 99% yield and in more than 99% ee. Moreover, the novel one-pot tandem process, one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process, was developed. This method was successfully utilized for the efficient synthesis of beta-aryl alpha-hydroxy amides, including beta-aryllactyl-leucine methyl esters. Interestingly, it was found that beneficial modifications on the Pd catalyst were achieved by the constituents of the first epoxidation, producing a more suitable catalyst for the Pd-catalyzed epoxide opening reaction in terms of chemoselectivity.

Determination of carbonyl compounds (acetaldehyde and formaldehyde in polyethylene terephthalate containers designated for water conservation

Directory of Open Access Journals (Sweden)

Redžepović Azra S.

2012-01-01

Full Text Available Polyethylene terephthalate (PET has in the last several years become the main packaging material for many food products, particularly carbonated beverages and bottled water, as well as for products of chemical industry (packaging of various hygiene maintenance agents, pesticides, solvents, etc.. The strength and permeability properties of PET are very good for packaging of beverages, its resistance to chemicals is high and it has a high degree of transparency. Acetaldehyde and formaldehyde are formed during the thermoforming of PET containers. After cooling, acetaldehyde and formaldehyde remain trapped in the walls of a PET bottle and may migrate into the water after filling and storage. Since there are no migration tests in Serbia prescribed for the determination of acetaldehyde and formaldehyde, the purpose of the paper is to test the quantitative contents of carbonyl compounds (acetaldehyde and formaldehyde in PET containers of different volumes, made by various manufacturers of bottled mineral carbonated and noncarbonated water, and exposed to different temperatures. In this study, the migration of acetaldehyde and formaldehyde from PET bottles into mineral carbonated and noncarbonated water was determined by high performance liquid chromatography. Taking into consideration that formaldehyde and acetaldehyde have no UV active or fluorescent group, the chromatography shall be preceded by derivatization in a closed system (due to a low boiling point of acetaldehyde and formaldehyde, which shall transform carbonyl compounds into UV active compounds.

Characteristics and personal exposures of carbonyl compounds in the subway stations and in-subway trains of Shanghai, China.

Science.gov (United States)

Feng, Yanli; Mu, Cuicui; Zhai, Jinqing; Li, Jian; Zou, Ting

2010-11-15

Carbonyl compounds including their concentrations, potential sources, diurnal variations and personal exposure were investigated in six subway stations and in-subway trains in Shanghai in June 2008. The carbonyls were collected onto solid sorbent (Tenax TA) coated with pentafluorophenyl hydrazine (PFPH), followed by solvent extraction and gas chromatography (GC)/mass spectrometry (MS) analysis of the PFPH derivatives. The total carbonyl concentrations of in-subway train were about 1.4-2.5 times lower than in-subway stations. A significant correlation (R>0.5, psubway stations. The diurnal variations in both the subway station and in-subway train showed that the concentrations of most carbonyls were much higher in the morning rush hour than in other sampling periods. Additionally, pronounced diurnal variations of acetaldehyde concentration before and after the evening peak hour in the subway train suggested that passengers contributed to high acetaldehyde levels. The personal exposure showed that the underground subway stations were important microenvironment for exposure to formaldehyde and acetaldehyde. Copyright © 2010 Elsevier B.V. All rights reserved.

General and Efficient a-Oxygenation of Carbonyl Compounds by TEMPO Induced by Single-Electron-Transfer Oxidation of Their Enolates

Czech Academy of Sciences Publication Activity Database

Dinca, E.; Hartmann, P.; Smrček, Jakub; Dix, I.; Jones, P. G.; Jahn, Ullrich

-, č. 24 (2012), s. 4461-4482 ISSN 1434-193X Institutional support: RVO:61388963 Keywords : carbonyl compounds * oxidation * radicals * electron transfer * enolates Subject RIV: CC - Organic Chemistry Impact factor: 3.344, year: 2012

Exciton Coupling in Circular Dichroic Spectroscopy as a Tool for Establishing the Absolute Configuration of alpha,beta-Unsaturated Esters of Allylic Alcohols

DEFF Research Database (Denmark)

Lauridsen, A.; Cornett, Claus; Christensen, S. B.

1991-01-01

alpha-beta-Unsaturated esters of allylic alcohols have been shown to exhibit exciton coupling by circular dichroic spectroscopy. This coupling permits the establishment of the absolute configuration. The method was used to prove the absolute configuration at C-2 of archangelolide. Detailed NMR sp...

Reaction of phosphorus ylides with carbonyl compounds in supercritical carbon dioxide

International Nuclear Information System (INIS)

Jeong, Kyung Il; Kim, Hak Do; Shim, Jae Jin; Ra, Choon Sup

2004-01-01

The condensation reaction of (benzylene)triphenylphosphoranes with carbonyl compounds in supercritical carbon dioxide was examined. Reactions of (benzylene)phosphoranes (ca. 1 mmol) with several benzaldehydes in a supercritical carbon dioxide (80 .deg. C, 2,000 psi) containing THF entrainer (5%) in a 24 mL reactor proceed smoothly to yield olefination products in fairly good to excellent yields but slower, compared to reactions in a conventional THF solvent. Generally, phosphoranes that are not substituted with a nitro group show more (Z)-selective reactions with aromatic aldehydes under scCO 2 condition than in THF. The reaction of (benzylene)triphenylphosphosphoranes with 4-t-butylcyclohexanone gave the corresponding olefin compounds with a low conversion under both the supercritical carbon dioxide and the organic THF solvent. Our preliminary study showed the Wittig reaction carries out smoothly in supercritical carbon dioxide medium and also a possible tunability of this reaction pathway by adding a entrainer. The results would be useful for devising a novel process for the environmentally friendly Wittig reaction

High throughput assay for evaluation of reactive carbonyl scavenging capacity.

Science.gov (United States)

Vidal, N; Cavaille, J P; Graziani, F; Robin, M; Ouari, O; Pietri, S; Stocker, P

2014-01-01

Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

High throughput assay for evaluation of reactive carbonyl scavenging capacity

Directory of Open Access Journals (Sweden)

N. Vidal

2014-01-01

Full Text Available Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-β-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,β-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.

alpha,beta-unsaturated 2-acyl imidazoles as a practical class of dienophiles for the DNA-Based catalytic asymmetric diels-alder reaction in water

NARCIS (Netherlands)

Boersma, A.J.; Feringa, B.L.; Roelfes, G.

2007-01-01

alpha,beta-Unsaturated 2-acyl imidazoles are a novel and practical class of dienophiles for the DNA-based catalytic asymmetric Diels-Alder reaction in water. The Diels-Alder products are obtained with very high diastereoselectivities and enantioselectivities in the range of 83-98%. The catalytic

Flame retardant synergism between molybdenum and halogen-containing compounds in unsaturated polyesters. [Smoke suppression

Energy Technology Data Exchange (ETDEWEB)

Skinner, G.A.; Parker, L.E.; Marshall, P.J.

1978-01-01

Oxygen index results for a series of unsaturated polyesters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between molybdenum and halogen. With the halogenated compounds used, the magnitude of the effect was greater in the presence of bromine but was dependent on the type of compound. When dibromoneopentyl glycol was used as the bromine source, the synergistic effect exhibited by molybdenum oxide was comparable to that shown by antimony oxide. Since molybdenum oxide also acts as a smoke suppressant, it could offer a useful alternative to antimony oxide particularly in the light of probable changes in standards and regulatory control regarding smoke emission. 4 figures, 2 tables.

Reaction of phosphorus ylides with carbonyl compounds in supercritical carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kyung Il; Kim, Hak Do; Shim, Jae Jin; Ra, Choon Sup [Yeungnam Univ., Gyongsan (Korea, Republic of)

2004-02-15

The condensation reaction of (benzylene)triphenylphosphoranes with carbonyl compounds in supercritical carbon dioxide was examined. Reactions of (benzylene)phosphoranes (ca. 1 mmol) with several benzaldehydes in a supercritical carbon dioxide (80 .deg. C, 2,000 psi) containing THF entrainer (5%) in a 24 mL reactor proceed smoothly to yield olefination products in fairly good to excellent yields but slower, compared to reactions in a conventional THF solvent. Generally, phosphoranes that are not substituted with a nitro group show more (Z)-selective reactions with aromatic aldehydes under scCO{sub 2} condition than in THF. The reaction of (benzylene)triphenylphosphosphoranes with 4-t-butylcyclohexanone gave the corresponding olefin compounds with a low conversion under both the supercritical carbon dioxide and the organic THF solvent. Our preliminary study showed the Wittig reaction carries out smoothly in supercritical carbon dioxide medium and also a possible tunability of this reaction pathway by adding a entrainer. The results would be useful for devising a novel process for the environmentally friendly Wittig reaction.

Elevated Levels of Carbonyl Compounds in the Atmosphere of Eastern Himalaya in India

Science.gov (United States)

Sarkar, C.; Chatterjee, A.; Majumdar, D.; Raha, S.; Ghosh, S. K.; Srivastava, A.

2015-12-01

A first ever study on atmospheric carbonyl compounds (CC) were made over eastern Himalaya in India. Samples were collected over a high altitude hill station, Darjeeling (27.01°N, 88.15°E, 2200 masl) during 2011-2012. It is well known that CC have toxic and carcinogenic properties as well as they have important effects on regional climate. Therefore their presence in the environment is of great concern especially for the Himalayan region because of the ecological and geographical importance of the area. The average annual concentration of total CCs was 293.3 ± 463.9 μgm-3 with maximum during post monsoon (1104.8 ± 568.0 μgm-3) and minimum during winter season (72.2 ± 42.9 μgm-3). Darjeeling experiences huge emissions of carbonaceous pollutants from massive influx of tourists during premonsoon and postmonsoon seasons. Though the emission strength could be comparable, the loss of carbonyls from the atmosphere could be due to photochemical degradation under high solar insolation during premonsoon. Acetone was most abundant species with an annual average concentration of 200.8±352.9 μgm-3 with 70 % contribution to the total CCs measured. Interestingly, acetone over Darjeeling was found to be much higher than most of the metropolitan cities in the world. The average formaldehyde to acetaldehyde ratio (1.64 ± 1.43) over Darjeeling is a good representation of a typical urban atmosphere at this high altitude over this part of Himalaya. High carbonyl concentration over eastern Himalaya compared to other megacities across the globe could be attributed to uncontrolled activities related to development in tourism, high population density and moreover it's unique orography and land use pattern with narrow roads, unplanned township etc. The unscientific treatment of human and animal and other domestic waste is another major concern which significantly contribute to carbonyl and other carbonaceous pollutants over this part of Himalaya.

Synthesis of morpholine derivatives and Bunte's salt as compounds of potential radioprotective activity

Energy Technology Data Exchange (ETDEWEB)

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

1980-01-01

The purpose of the present study was to obtain several compounds possessing radioprotective activity. The syntheses yielded seven undescribed compounds i.e.: benzyl ester of the N-morpholinecarbathionothioglicol acid, ester bis S-(morpholine-4-thiocarbonyl)-2-thioethyl, morpholine salt of the N-morpholinecarbothionothiolic acid, sodium and potassium salt of S-morpholine-4-carbonyl, methylthiosulfate, sodium and potassium salt of beta-hydroxyethyl thiosulfate. Moreover, with the aid of other methods following compounds were synthetized: beta-S-(morpholine-4-thiocarbonyl) ethyl thiopropioniane, amide of the S-(morpholine-4-thiocarbonyl)-thioglicol acid, acid S-(morpholine-4-thiocarbonyl)-thioglicol acid, sodium salt of the S-(morpholine-4-thiocarbonyl)-thioglicol acid. The structure of these compounds was confirmed using elementary and spectral analysis.

Amberlyst-15: An Efficient and reusable heterogeneous catalyst for the synthesis of β-amino carbonyl compounds

Directory of Open Access Journals (Sweden)

Pathakota Venkata Ramana

2015-12-01

Full Text Available A simple and efficient method has been developed for the synthesis of β-amino carbonyl compounds from aromatic ketones, aldehydes and amines by Mannich reaction in the presence of amberlyst-15 as a reusable heterogeneous catalyst at room temperature under solvent-free conditions. The noteworthy advantages of the present method are short reaction times, good product yields, simple procedures and use of non-toxic catalyst.

Ruthenium supported on magnetic nanoparticles: An efficient and recoverable catalyst for hydrogenation of alkynes and transfer hydrogenation of carbonyl compounds

Science.gov (United States)

Ruthenium supported on surface modified magnetic nanoparticles (NiFe2O4) has been successfully synthesized and applied for hydrogenation of alkynes at room temperature as well as transfer hydrogenation of a number of carbonyl compounds under microwave irradiation conditions. The ...

Carbonyl compound emissions from a heavy-duty diesel engine fueled with diesel fuel and ethanol-diesel blend.

Science.gov (United States)

Song, Chonglin; Zhao, Zhuang; Lv, Gang; Song, Jinou; Liu, Lidong; Zhao, Ruifen

2010-05-01

This paper presents an investigation of the carbonyl emissions from a direct injection heavy-duty diesel engine fueled with pure diesel fuel (DF) and blended fuel containing 15% by volume of ethanol (E/DF). The tests have been conducted under steady-state operating conditions at 1200, 1800, 2600 rpm and idle speed. The experimental results show that acetaldehyde is the most predominant carbonyl, followed by formaldehyde, acrolein, acetone, propionaldehyde and crotonaldehyde, produced from both fuels. The emission factors of total carbonyls vary in the range 13.8-295.9 mg(kWh)(-1) for DF and 17.8-380.2mg(kWh)(-1) for E/DF, respectively. The introduction of ethanol into diesel fuel results in a decrease in acrolein emissions, while the other carbonyls show general increases: at low engine speed (1200 rpm), 0-55% for formaldehyde, 4-44% for acetaldehyde, 38-224% for acetone, and 5-52% for crotonaldehyde; at medium engine speed (1800 rpm), 106-413% for formaldehyde, 4-143% for acetaldehyde, 74-113% for acetone, 114-1216% for propionaldehyde, and 15-163% for crotonaldehyde; at high engine speed (2600 rpm), 36-431% for formaldehyde, 18-61% for acetaldehyde, 22-241% for acetone, and 6-61% for propionaldehyde. A gradual reduction in the brake specific emissions of each carbonyl compound from both fuels is observed with increase in engine load. Among three levels of engine speed employed, both DF and E/DF emit most CBC emissions at high engine speed. On the whole, the presence of ethanol in diesel fuel leads to an increase in aldehyde emissions. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Ruthenium(II carbonyl compounds with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand

Directory of Open Access Journals (Sweden)

Rajendhraprasad Tatikonda

2017-04-01

Full Text Available Two ruthenium carbonyl complexes with the 4′-chloro-2,2′:6′,2′′-terpyridine ligand (tpy-Cl, C15H10ClN3, i.e. [RuCl(tpy-Cl(CO2][RuCl3(CO3] (I [systematic name: cis-dicarbonylchlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ3Nruthenium(II fac-tricarbonyltrichloridoruthenate(II], and [RuCl2(tpy-Cl(CO2] (II [cis-dicarbonyl-trans-dichlorido(4′-chloro-2,2′:6′,2′′-terpyridine-κ2N1,N1′ruthenium(II], were synthesized and characterized by single-crystal X-ray diffraction. The RuII atoms in both centrosymmetric structures (I and (II display similar, slightly distorted octahedral coordination spheres. The coordination sphere in the complex cation in compound (I is defined by three N atoms of the tridentate tpy-Cl ligand, two carbonyl carbon atoms and one chlorido ligand; the charge is balanced by an octahedral [Ru(CO3Cl3]− counter-anion. In the neutral compound (II, the tpy-Cl ligand coordinates to the metal only through two of its N atoms. The coordination sphere of the RuII atom is completed by two carbonyl and two chlorido ligands. In the crystal structures of both (I and (II, weak C—H...Cl interactions are observed.

Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

2016-05-15

Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

Science.gov (United States)

Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

2016-05-01

Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

CO- and HCl-free synthesis of acid chlorides from unsaturated hydrocarbons via shuttle catalysis

Science.gov (United States)

Fang, Xianjie; Cacherat, Bastien; Morandi, Bill

2017-11-01

The synthesis of carboxylic acid derivatives from unsaturated hydrocarbons is an important process for the preparation of polymers, pharmaceuticals, cosmetics and agrochemicals. Despite its industrial relevance, the traditional Reppe-type carbonylation reaction using pressurized CO is of limited applicability to laboratory-scale synthesis because of: (1) the safety hazards associated with the use of CO, (2) the need for special equipment to handle pressurized gas, (3) the low reactivity of several relevant nucleophiles and (4) the necessity to employ different, often tailor-made, catalytic systems for each nucleophile. Herein we demonstrate that a shuttle-catalysis approach enables a CO- and HCl-free transfer process between an inexpensive reagent, butyryl chloride, and a wide range of unsaturated substrates to access the corresponding acid chlorides in good yields. This new transformation provides access to a broad range of carbonyl-containing products through the in situ transformation of the reactive acid chloride intermediate. In a broader context, this work demonstrates that isodesmic shuttle-catalysis reactions can unlock elusive catalytic reactions.

The use of biodiesel blends on a non-road generator and its impacts on ozone formation potentials based on carbonyl emissions

International Nuclear Information System (INIS)

Chai, Ming; Lu, Mingming; Liang, Fuyan; Tzillah, Aisha; Dendramis, Nancy; Watson, Libya

2013-01-01

In this study, emissions of carbonyl compounds from the use B50 and B100 were measured with a non-road diesel generator. A total of 25 carbonyl compounds were identified in the exhaust, including 10 with laboratory-synthesized standards. Formaldehyde, acetaldehyde, and acrolein were found as the most abundant carbonyl compounds emitted for both diesel and biodiesel. The sulphur content of diesel fuels and the source of biodiesel fuels were not found to have a significant impact on the emission of carbonyl compounds. The overall maximum incremental reactivity (MIR) was the highest at 0 kW and slightly increased from 25 to 75 kW. The MIR of B100 was the highest, followed by diesel and B50, which is consistent with the emission rates of total carbonyl compounds. This suggests that the use of biodiesel blends may be more beneficial to the environment than using pure biodiesel. -- Highlights: •Carbonyl compound emission from biodiesel blends combustion on a non-road generator. •25 compounds were identified, including 10 by laboratory-synthesized standards. •Sources of biodiesel have insignificant impacts on carbonyl compounds emission. •Sulphur contents have insignificant impacts on carbonyl compounds emission. •MIR of emitted carbonyls decreases in the following order: B100, diesel, B50. -- The study found that B50 resulted in lower total carbonyl emission rates and ozone formation potential resultant from these compounds, whereas both increased with B100

Ruthenium(ii)-catalyzed olefination via carbonyl reductive cross-coupling.

Science.gov (United States)

Wei, Wei; Dai, Xi-Jie; Wang, Haining; Li, Chenchen; Yang, Xiaobo; Li, Chao-Jun

2017-12-01

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KO t Bu and bidentate phosphine dmpe is vital to this transformation.

Base-catalyzed efficient tandem [3 + 3] and [3 + 2 + 1] annulation-aerobic oxidative benzannulations.

Science.gov (United States)

Diallo, Aboubacar; Zhao, Yu-Long; Wang, He; Li, Sha-Sha; Ren, Chuan-Qing; Liu, Qun

2012-11-16

An efficient synthesis of substituted benzenes via a base-catalyzed [3 + 3] aerobic oxidative aromatization of α,β-unsaturated carbonyl compounds with dimethyl glutaconate was reported. All the reactions were carried out under mild, metal-free conditions to afford the products in high to excellent yields with molecular oxygen as the sole oxidant and water as the sole byproduct. Furthermore, a more convenient tandem [3 + 2 + 1] aerobic oxidative aromatization reaction was developed through the in situ generation of the α,β-unsaturated carbonyl compounds from aldehydes and ketones.

Frustrated Lewis pairs-assisted reduction of carbonyl compounds

DEFF Research Database (Denmark)

Marek, Ales; Pedersen, Martin Holst Friborg

2015-01-01

An alternative and robust method for the reduction of carbonyl groups by frustrated Lewis pairs (FLPs) is reported in this paper. With its very mild reaction conditions, good to excellent yields, absolute regioselectivity and the non-metallic character of the reagent, it provides an excellent too...

Synthesis of Cyclohexane-Fused Isocoumarins via Cationic Palladium(II)-Catalyzed Cascade Cyclization Reaction of Alkyne-Tethered Carbonyl Compounds Initiated by Intramolecular Oxypalladation of Ester-Substituted Aryl Alkynes.

Science.gov (United States)

Zhang, Jianbo; Han, Xiuling; Lu, Xiyan

2016-04-15

A cationic Pd(II)-catalyzed cascade cyclization reaction of alkyne-tethered carbonyl compounds was developed. This reaction is initiated by intramolecular oxypalladation of alkynes with an ester group followed by 1,2-addition of the formed C-Pd(II) bond to the carbonyl group, providing a highly efficient method for the synthesis of cyclohexane-fused isocoumarins.

Accumulation of carbonyls accelerates the formation of pentosidine, an advanced glycation end product: carbonyl stress in uremia.

Science.gov (United States)

Miyata, T; Ueda, Y; Yamada, Y; Izuhara, Y; Wada, T; Jadoul, M; Saito, A; Kurokawa, K; van Ypersele de Strihou, C

1998-12-01

Advanced glycation end product (AGE) formation is related to hyperglycemia in diabetes but not in uremia, because plasma AGE levels do not differ between diabetic and nondiabetic hemodialysis patients. The mechanism of this phenomenon remains elusive. Previously, it was suggested that elevation of AGE levels in uremia might result from the accumulation of unknown AGE precursors. The present study evaluates the in vitro generation of pentosidine, a well identified AGE structure. Plasma samples from healthy subjects and nondiabetic hemodialysis patients were incubated under air for several weeks. Pentosidine levels were determined at intervals by HPLC assay. Pentosidine rose to a much larger extent in uremic than in control plasma. Pentosidine yield, i.e., the change in pentosidine level between 0 and 4 wk divided by 28 d, averaged 0.172 nmol/ml per d in uremic versus 0.072 nmol/ml per d in control plasma (P aminoguanidine and OPB-9195, which inhibit the Maillard reaction, lowered pentosidine yield in both uremic and control plasma. When ultrafiltrated plasma was exposed to 2,4-dinitrophenylhydrazine, the yield of hydrazones, formed by interaction with carbonyl groups, was markedly higher in uremic than in control plasma. These observations strongly suggest that the pentosidine precursors accumulated in uremic plasma are carbonyl compounds. These precursors are unrelated to glucose or ascorbic acid, whose concentration is either normal or lowered in uremic plasma. They are also unrelated to 3-deoxyglucosone, a glucose-derived dicarbonyl compound whose level is raised in uremic plasma: Its addition to normal plasma fails to increase pentosidine yield. This study reports an elevated level of reactive carbonyl compounds ("carbonyl stress") in uremic plasma. Most have a lower than 5000 Da molecular weight and are thus partly removed by hemodialysis. Their effect on pentosidine generation can be inhibited by aminoguanidine or OPB-9195. Carbonyl stress might contribute to

Antibacterial and DNA cleavage activity of carbonyl functionalized N-heterocyclic carbene-silver(I) and selenium compounds

Science.gov (United States)

Haque, Rosenani A.; Iqbal, Muhammad Adnan; Mohamad, Faisal; Razali, Mohd R.

2018-03-01

The article describes syntheses and characterizations of carbonyl functionalized benzimidazolium salts, I-IV. While salts I-III are unstable at room temperature, salt IV remained stable and was further utilised to form N-heterocyclic carbene (NHC) compounds of silver(I), V and VI, and selenium compound, VII respectively. Compounds IV-VII were tested for their antibacterial potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Salt IV shows a very low inhibition potential (minimum inhibitory concentration, MIC 500 μg/mL) compared to the respective silver(I)-NHC, V and VI (MIC 31.25 μg/mL against both, E. coli and S. aureus) and selenium compound, VII (MIC 125 μg/mL against E. coli and 62.50 μg/mL against S. aureus). In DNA cleavage abilities, all the test compounds cleave DNA in which the VII cleaves the DNA at the faster rate. Meanwhile, the silver(I)-NHC complexes V and VI act at the same mode and pattern of DNA cleavage while VII is similar to IV.

Strategic Design of an Effective beta-Lactamase Inhibitor

Energy Technology Data Exchange (ETDEWEB)

Pattanaik, P.; Bethel, C; Hujer, A; Hujer, K; Distler, A; Taracila, M; Anderson, V; Fritsche, T; Jones, R; et. al.

2009-01-01

In an effort to devise strategies for overcoming bacterial beta-lactamases, we studied LN-1-255, a 6-alkylidene-2'-substituted penicillin sulfone inhibitor. By possessing a catecholic functionality that resembles a natural bacterial siderophore, LN-1-255 is unique among beta-lactamase inhibitors. LN-1-255 combined with piperacillin was more potent against Escherichia coli DH10B strains bearing bla(SHV) extended-spectrum and inhibitor-resistant beta-lactamases than an equivalent amount of tazobactam and piperacillin. In addition, LN-1-255 significantly enhanced the activity of ceftazidime and cefpirome against extended-spectrum cephalosporin and Sme-1 containing carbapenem-resistant clinical strains. LN-1-255 inhibited SHV-1 and SHV-2 beta-lactamases with nm affinity (K(I) = 110 +/- 10 and 100 +/- 10 nm, respectively). When LN-1-255 inactivated SHV beta-lactamases, a single intermediate was detected by mass spectrometry. The crystal structure of LN-1-255 in complex with SHV-1 was determined at 1.55A resolution. Interestingly, this novel inhibitor forms a bicyclic aromatic intermediate with its carbonyl oxygen pointing out of the oxyanion hole and forming hydrogen bonds with Lys-234 and Ser-130 in the active site. Electron density for the 'tail' of LN-1-255 is less ordered and modeled in two conformations. Both conformations have the LN-1-255 carboxyl group interacting with Arg-244, yet the remaining tails of the two conformations diverge. The observed presence of the bicyclic aromatic intermediate with its carbonyl oxygen positioned outside of the oxyanion hole provides a rationale for the stability of this inhibitory intermediate. The 2'-substituted penicillin sulfone, LN-1-255, is proving to be an important lead compound for novel beta-lactamase inhibitor design.

New degradation compounds from lignocellulosic biomass pretreatment: routes for formation of potent oligophenolic enzyme inhibitors

DEFF Research Database (Denmark)

Rasmussen, H.; Tanner, David Ackland; Sørensen, H. R.

2017-01-01

-condensation reactions involving aldol condensations, 1,4 additions to α,β unsaturated carbonyl compounds, 3-keto acid decarboxylations and oxidations. Furthermore, pentose reactions with phenolic lignin components are suggested. The identification of the central role of xylose in the reaction routes for oligophenolic...... inhibitor formation led to the solution to protect the reactive anomeric center in xylose. It is shown that protection of the anomeric center in in situ generated xylose with ethylene glycol monobutyl ether, during pretreatment of wheat straw, reduces the level of oligophenols by 73%. The results pave...

Glutathione transferase mimics : Micellar catalysis of an enzymic reaction

NARCIS (Netherlands)

Lindkvist, Björn; Weinander, Rolf; Engman, Lars; Koetse, Marc; Engberts, Jan B.F.N.; Morgenstern, Ralf

1997-01-01

Substances that mimic the enzyme action of glutathione transferases (which serve in detoxification) are described. These micellar catalysts enhance the reaction rate between thiols and activated halogenated nitroarenes as well as alpha,beta-unsaturated carbonyls. The nucleophilic aromatic

Reciprocal carbonyl-carbonyl interactions in small molecules and proteins.

Science.gov (United States)

Rahim, Abdur; Saha, Pinaki; Jha, Kunal Kumar; Sukumar, Nagamani; Sarma, Bani Kanta

2017-07-19

Carbonyl-carbonyl n→π* interactions where a lone pair (n) of the oxygen atom of a carbonyl group is delocalized over the π* orbital of a nearby carbonyl group have attracted a lot of attention in recent years due to their ability to affect the 3D structure of small molecules, polyesters, peptides, and proteins. In this paper, we report the discovery of a "reciprocal" carbonyl-carbonyl interaction with substantial back and forth n→π* and π→π* electron delocalization between neighboring carbonyl groups. We have carried out experimental studies, analyses of crystallographic databases and theoretical calculations to show the presence of this interaction in both small molecules and proteins. In proteins, these interactions are primarily found in polyproline II (PPII) helices. As PPII are the most abundant secondary structures in unfolded proteins, we propose that these local interactions may have implications in protein folding.Carbonyl-carbonyl π* non covalent interactions affect the structure and stability of small molecules and proteins. Here, the authors carry out experimental studies, analyses of crystallographic databases and theoretical calculations to describe an additional type of carbonyl-carbonyl interaction.

Study of electrocatalytic properties of iridium carbonyl cluster and rhodium carbonyl cluster compounds for the oxygen reduction and hydrogen oxidation reactions in 0.5 MH{sub 2}SO{sub 4} in presence and absence of methanol and carbon monoxide, respectively

Energy Technology Data Exchange (ETDEWEB)

Uribe-Godinez, J.; Borja-Arco, E.; Castellanos, R.H. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Escobedo (Mexico); Jimenez-Sandoval, O. [Centro de Investigacion y de Estudios Avanzados del Inst. Politecnico Nacional, Querataro (Mexico)

2006-07-01

The suitability of carbonyl cluster compounds as a substitute to platinum (Pt) in fuel cell catalysts was investigated. Iridium (Ir{sub 4}(CO){sub 12} and rhodium (Rh{sub 6}(CO){sub 116}) cluster compounds were investigated as potential new electrocatalysts for oxygen reduction reaction (ORR) in the presence and absence of methanol at different concentrations, as well as for the hydrogen oxidation reaction (HOR) with pure hydrogen and a hydrogen/carbon monoxide mixture. The materials were studied using room temperature rotating disk electrode (RDE) measurements and cyclic and linear sweep voltammetry techniques (LSV). Tafel slope and exchange current density were calculated using the LSV polarization curves. Cyclic voltamperometry results suggested that the electrocatalysts were tolerant to methanol. However, electrochemical behaviour of the materials altered in the presence of CO, and peaks corresponding to CO oxidation were observed in both cases. The rhodium carbonyl showed a higher current density for the ORR than the iridium carbonyl. The current potential curves in the presence of methanol were similar to those obtained without methanol. Results confirmed the tolerance properties of the materials to perform the ORR. Decreased current density values were observed during HOR, and were attributed to changes in the hydrogen solubility and diffusion coefficient due to the presence of CO. The Tafel slopes indicated that the mechanics of the HOR were Heyrovsky-Volmer. Results showed that the materials are capable of performing both ORR and HOR in an acid medium. It was noted that the iridium carbonyl cluster followed a 4-electron transfer mechanism towards the formation of water. It was concluded that the compounds are suitable for use as both cathodes and anodes in proton exchange membrane fuel cells (PEMFCs) and as cathodes in direct methanol fuel cells (DMFCs). 3 refs., 2 tabs., 3 figs.

Beta-galactosidase catalyzed selective galactosylation of aromatic compounds.

Science.gov (United States)

Bridiau, Nicolas; Taboubi, Selma; Marzouki, Nejib; Legoy, Marie Dominique; Maugard, Thierry

2006-01-01

A new approach to galacto-oligosaccharides and galacto-conjugates synthesis performed by the beta-galactosidase from Kluyveromyces lactis is reported. The enzymatic galactosylation of eight kinds of adsorbed aromatic primary alcohols, in particular the two drugs guaifenesin and chlorphenesin, gave the corresponding beta-D-galacto-pyranosides in yields ranging between approximately 10% and 96%. For the first time, we have showed that the adsorption of acceptor substrates onto solid supports such as silica gel influences the yield and the selectivity of galacto-conjugates synthesis. In particular, we observed that adsorption of acceptor favored the synthesis of digalactosylated compounds.

Reactive carbonyl compounds impair wound healing by vimentin collapse and loss of the primary cilium.

Science.gov (United States)

Rodríguez-Ribera, Lara; Slattery, Craig; Mc Morrow, Tara; Marcos, Ricard; Pastor, Susana

2017-10-01

In renal pathologies tubulo-interstitial fibrosis results from an aberrant wound-healing ability where the normal epithelial tissue is substituted for scar tissue caused by accumulation of extracellular matrix proteins (ECM). During the wound-healing process, epithelial cells may undergo epithelial-mesenchymal transition (EMT) acquiring a mesenchymal-like phenotype that allows cells to migrate and re-epithelialize the wound site. It has been reported that chronic inflammation and uremic milieu are involved in wound-healing and enhanced kidney damage in chronic kidney disease (CKD) patients. In this study we evaluated reactive carbonyl compounds (RCC) effects on renal wound healing. The compounds resulting from carbonyl stress evaluated in this study were glyoxal (GO), methylglyoxal (MGO), malondialdehyde (MDA) and 4-hydroxy-hexenal (HHE). Wound repair ability was evaluated by the wound healing assay using HK-2 cells. EMT was evaluated by morphological, protein and transcriptional changes using microscopy, western blot, zymography and RT-qPCR. Changes in the vimentin network and primary cilia were assessed by immunofluorescence. Our data demonstrated that MDA and GO delay wound closure mediated by vimentin disruption, which caused collagen I mRNA decrease, and deciliation. In contrast, HHE treatment (and MGO to a minor degree) induced morphological changes and increased mesenchymal marker expression and gelatinase activity in HK-2 cells. In this study, we have demonstrated for the first time that exposure to RCC differentially affects wound healing in proximal tubular epithelia. A better comprehension of effects of uremic toxins on wound healing and fibrosis and migration is necessary to seek mechanisms to slow down renal fibrosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrocatalytic hydrogenation and hydrodeoxygenation of oxygenated and unsaturated organic compounds

Energy Technology Data Exchange (ETDEWEB)

Jackson, James E.; Lam, Chun Ho; Saffron, Christopher M.; Miller, Dennis J.

2018-04-24

A process and related electrode composition are disclosed for the electrocatalytic hydrogenation and/or hydrodeoxygenation of organic substrates such as biomass-derived bio-oil components by the production of hydrogen atoms on a catalyst surface followed by the reaction of the hydrogen atoms with the organic reactants. Biomass fast pyrolysis-derived bio-oil is a liquid mixture containing hundreds of organic compounds with chemical functionalities that are corrosive to container materials and are prone to polymerization. A high surface area skeletal metal catalyst material such as Raney Nickel can be used as the cathode. Electrocatalytic hydrogenation and/or hydrodeoxygenation convert the organic substrates under mild conditions to reduce coke formation and catalyst deactivation. The process converts oxygen-containing functionalities and unsaturated bonds into chemically reduced forms with an increased hydrogen content. The process is operated at mild conditions, which enables it to be a good means for stabilizing bio-oil to a form that can be stored and transported using metal containers and pipes.

Determination of carbonyl compounds in air by HPLC; Determinacion de compuestos carbonilicos en aire por HPLC

Energy Technology Data Exchange (ETDEWEB)

Garcia, S; Perez, R M; Campos, A; Gonzalez, D

1995-07-01

A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak Cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetoacetonitrile. Three different types of samples (rural, urban, petrol emission) were successfully analyzed. (Author) 12 refs.

Temporal variation of carbonyl compound concentrations at a semi-rural site in Denmark

DEFF Research Database (Denmark)

Christensen, C.S.; Skov, H.; Nielsen, T.

2000-01-01

The atmospheric concentrations of formaldehyde, acetaldehyde and acetone were measured by the DNPH-technique at the semi-rural site Lille Valby, Denmark (55 degrees N) between May-July 1995, The average concentrations were observed to be 1.2 ppbv for formaldehyde, 0.8 ppbv for acetaldehyde and 1.......9 ppbv for acetone, For the set of carbonyl compounds, concentrations were found to be highly correlated, though only during daytime, The weak correlations observed during nighttime are believed to be caused by the dry deposition of especially formaldehyde, During periods with low photochemical activity...... of hydrocarbons during long-range transport. Especially, the concentration levels of acetone showed a pronounced seasonal-variation with the highest levels observed during summertime and lowest in winter and spring. The seasonal variation in the concentration levels of formaldehyde and acetaldehyde were small...

Carbonyl Compounds Produced by Vaporizing Cannabis Oil Thinning Agents.

Science.gov (United States)

Troutt, William D; DiDonato, Matthew D

2017-11-01

Cannabis use has increased in the United States, particularly the use of vaporized cannabis oil, which is often mixed with thinning agents for use in vaporizing devices. E-cigarette research shows that heated thinning agents produce potentially harmful carbonyls; however, similar studies have not been conducted (1) with agents that are commonly used in the cannabis industry and (2) at temperatures that are appropriate for cannabis oil vaporization. The goal of this study was to determine whether thinning agents used in the cannabis industry produce potentially harmful carbonyls when heated to a temperature that is appropriate for cannabis oil vaporization. Four thinning agents (propylene glycol [PG], vegetable glycerin [VG], polyethylene glycol 400 [PEG 400], and medium chain triglycerides [MCT]) were heated to 230°C and the resulting vapors were tested for acetaldehyde, acrolein, and formaldehyde. Each agent was tested three times. Testing was conducted in a smoking laboratory. Carbonyl levels were measured in micrograms per puff block. Analyses showed that PEG 400 produced significantly higher levels of acetaldehyde and formaldehyde than PG, MCT, and VG. Formaldehyde production was also significantly greater in PG compared with MCT and VG. Acrolein production did not differ significantly across the agents. PG and PEG 400 produced high levels of acetaldehyde and formaldehyde when heated to 230°C. Formaldehyde production from PEG 400 isolate was particularly high, with one inhalation accounting for 1.12% of the daily exposure limit, nearly the same exposure as smoking one cigarette. Because PG and PEG 400 are often mixed with cannabis oil, individuals who vaporize cannabis oil products may risk exposure to harmful formaldehyde levels. Although more research is needed, consumers and policy makers should consider these potential health effects before use and when drafting cannabis-related legislation.

16th Carbonyl Metabolism Meeting: from enzymology to genomics

Directory of Open Access Journals (Sweden)

Maser Edmund

2012-12-01

Full Text Available Abstract The 16th International Meeting on the Enzymology and Molecular Biology of Carbonyl Metabolism, Castle of Ploen (Schleswig-Holstein, Germany, July 10–15, 2012, covered all aspects of NAD(P-dependent oxido-reductases that are involved in the general metabolism of xenobiotic and physiological carbonyl compounds. Starting 30 years ago with enzyme purification, structure elucidation and enzyme kinetics, the Carbonyl Society members have meanwhile established internationally recognized enzyme nomenclature systems and now consider aspects of enzyme genomics and enzyme evolution along with their roles in diseases. The 16th international meeting included lectures from international speakers from all over the world.

Discovery of nonsteroidal 17beta-hydroxysteroid dehydrogenase 1 inhibitors by pharmacophore-based screening of virtual compound libraries.

Science.gov (United States)

Schuster, Daniela; Nashev, Lyubomir G; Kirchmair, Johannes; Laggner, Christian; Wolber, Gerhard; Langer, Thierry; Odermatt, Alex

2008-07-24

17Beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) plays a pivotal role in the local synthesis of the most potent estrogen estradiol. Its expression is a prognostic marker for the outcome of patients with breast cancer and inhibition of 17beta-HSD1 is currently under consideration for breast cancer prevention and treatment. We aimed to identify nonsteroidal 17beta-HSD1 inhibitor scaffolds by virtual screening with pharmacophore models built from crystal structures containing steroidal compounds. The most promising model was validated by comparing predicted and experimentally determined inhibitory activities of several flavonoids. Subsequently, a virtual library of nonsteroidal compounds was screened against the 3D pharmacophore. Analysis of 14 selected compounds yielded four that inhibited the activity of human 17beta-HSD1 (IC 50 below 50 microM). Specificity assessment of identified 17beta-HSD1 inhibitors emphasized the importance of including related short-chain dehydrogenase/reductase (SDR) members to analyze off-target effects. Compound 29 displayed at least 10-fold selectivity over the related SDR enzymes tested.

Role of protein-bound carbonyl groups in the formation of advanced glycation endproducts.

Science.gov (United States)

Liggins, J; Furth, A J

1997-08-22

Several mechanisms have been postulated for the formation of advanced glycation endproducts (AGEs) from glycated proteins; they all feature protein-bound carbonyl intermediates. Using 2,4-dinitrophenylhydrazine (DNPH), we have detected these intermediates on bovine serum albumin, lysozyme and beta-lactoglobulin after in vitro glycation by glucose or fructose. Carbonyls were formed in parallel with AGE-fluorophores, via oxidative Maillard reactions. Neither Amadori nor Heyns products contributed to the DNPH reaction. Fluorophore and carbonyl yields were much enhanced in lipid-associated proteins, but both groups could also be detected in lipid-free proteins. When pre-glycated proteins were incubated in the absence of free sugar, carbonyl groups were rapidly lost in a first-order reaction, while fluorescence continued to develop beyond the 21 days of incubation. Another unexpected finding was that not all carbonyl groups were blocked by aminoguanidine, although there was complete inhibition of reactions leading to AGE-fluorescence. It is suggested that carbonyls acting as fluorophore precursors react readily with aminoguanidine, while others are resistant to this hydrazine, possibly because they are involved in ring closure. Factors influencing the relative rates of acyclisation and hydrazone formation are discussed, together with possible implications for antiglycation therapy.

Actinic radiation-curable formulations from the reaction product of organic isocyanate, poly(alkylene oxide) polyol and an unsaturated addition-polymerizable monomeric compound having a single isocyanate-reactive hydrogen group

International Nuclear Information System (INIS)

Howard, D.D.

1979-01-01

Energy-curable compositions which can be cured in the presence of air by exposure to actinic radiation contain at least one unsaturated urethane oligomer. The oligomer comprises the reaction product of at least one poly(alkylene oxide) polyol, at least one polyisocyanate, and at least one unsaturated active hydrogen-containing compound

Lewis base catalyzed 1,3-dithiane addition to carbonyl and imino compounds using 2-trimethylsilyl-1,3-dithiane.

Science.gov (United States)

Michida, Makoto; Mukaiyama, Teruaki

2008-09-01

Lewis base-catalyzed 1,3-dithiane addition to electrophiles such as carbonyl compounds and N-substituted aldimines with 2-trimethylsilyl-1,3-dithiane (TMS-dithiane) is described. By the activation of the carbon-silicon bond in the presence of a Lewis base catalyst such as tetrabutylammonium phenoxide (PhONnBu(4)), a 1,3-dithiane addition reaction proceeded smoothly to afford the corresponding adducts in good to high yields under mild conditions. This synthesis is also applied to the reactions of ketones having alpha-protons, and of N-substituted aldimines.

Heterogeneous hydrogenation of unsaturated compounds with catalyst P-2-Ni with turnover numbers up to 90,000

Energy Technology Data Exchange (ETDEWEB)

Strohmeier, W; Pfoehler, M; Steigerwald, H [Wuerzburg Univ. (Germany, F.R.). Inst. fuer Physikalische Chemie

1977-12-01

Unsaturated compounds are very rapidly hydrogenated with nickel-boride catalyst P-2-Ni without solvent under mild conditions (70-85/sup 0/C and 10 bar). Turnover numbers UZ up to 90,000 and space-time-yields of 7.440 mmol product per l and 1 mgA Nickel in one hour with a mean catalyst activity a = 124 were observed. This hydrogenation catalyst has a power, which is in the same magnitude of very active noble metal catalysts.

PAH, BTEX, carbonyl compound, black-carbon, NO2 and ultrafine particle dynamometer bench emissions for Euro 4 and Euro 5 diesel and gasoline passenger cars

Science.gov (United States)

Louis, Cédric; Liu, Yao; Tassel, Patrick; Perret, Pascal; Chaumond, Agnès; André, Michel

2016-09-01

Although implementing Diesel particulate filters (DPF) and other novel aftertreatment technologies makes it possible to achieve significant reductions in particle mass emissions, it may induce the release of ultrafine particles and emissions of many other unregulated compounds. This paper focuses on (i) ultrafine particles, black carbon, BTEX, PAH, carbonyl compounds, and NO2 emissions from Euro 4 and Euro 5 Diesel and gasoline passenger cars, (ii) the influence of driving conditions (e.g., cold start, urban, rural and motorway conditions), and (iii) the impact of additive and catalysed DPF devices on vehicle emissions. Chassis dynamometer tests were conducted on four Euro 5 vehicles and two Euro 4 vehicles: gasoline vehicles with and without direct injection system and Diesel vehicles equipped with additive and catalysed particulate filters. The results showed that compared to hot-start cycles, cold-start urban cycles increased all pollutant emissions by a factor of two. The sole exception was NO2, which was reduced by a factor of 1.3-6. Particulate and black carbon emissions from the gasoline engines were significantly higher than those from the Diesel engines equipped with DPF. Moreover, the catalysed DPF emitted about 3-10 times more carbonyl compounds and particles than additive DPF, respectively, during urban driving cycles, while the additive DPF vehicles emitted 2 and 5 times more BTEX and carbonyl compounds during motorway driving cycles. Regarding particle number distribution, the motorway driving cycle induced the emission of particles smaller in diameter (mode at 15 nm) than the urban cold-start cycle (mode at 80-100 nm). The results showed a clear positive correlation between particle, black carbon, and BTEX emissions, and a negative correlation between particles and NO2.

X-ray investigations of sulfur-containing fungicides. II. Intramolecular forces governing the conformation of four novel alpha-phenylazo- and alpha-phenylhydrazono-beta-ketosulfones.

Science.gov (United States)

Wolf , W M

2001-02-01

The crystal and molecular structures of four novel beta-ketosulfones, phenyl benzoyl(phenylhydrazono)methyl sulfone (I), phenyl benzoyl(4-nitrophenylhydrazono)methyl sulfone (II), (benzoyl)(phenyl)(phenylazo)methyl phenyl sulfone (III) and (benzoyl)(phenyl)(3-chlorophenylazo)methyl 4-tolyl sulfone (IV), have been investigated using X-ray analysis and density functional theory supplemented by ab initio Hartree-Fock calculations. The conformations of (I) and (II) are stabilized by strong intramolecular resonance-assisted hydrogen bonds formed between the sulfonyl and the alpha-hydrazono moieties. The following increase of a positive charge on the S atoms is compensated via pi-conjugation and stereoelectronic back-donation from the nearby beta-carbonyl group. Compounds (III) and (IV) adopt a strongly distorted propeller shape with pivotal tetrahedral C1 atoms. Distortion mostly follows from the approximate coplanarity of the alpha-azophenyl and alpha-phenyl moieties opposite each other. The main stereoelectronic interactions involve the donation of electron density from the alpha-azo N2 towards the sulfonyl S and the beta-carbonyl C2 atoms.

Unsaturated free fatty acids increase benzodiazepine receptor agonist binding depending on the subunit composition of the GABAA receptor complex.

Science.gov (United States)

Witt, M R; Westh-Hansen, S E; Rasmussen, P B; Hastrup, S; Nielsen, M

1996-11-01

It has been shown previously that unsaturated free fatty acids (FFAs) strongly enhance the binding of agonist benzodiazepine receptor ligands and GABAA receptor ligands in the CNS in vitro. To investigate the selectivity of this effect, recombinant human GABAA/benzodiazepine receptor complexes formed by different subunit compositions (alpha x beta y gamma 2, x = 1, 2, 3, and 5; y = 1, 2, and 3) were expressed using the baculovirus-transfected Sf9 insect cell system. At 10(-4) M, unsaturated FFAs, particularly arachidonic (20:4) and docosahexaenoic (22:6) acids, strongly stimulated (> 200% of control values) the binding of [3H]flunitrazepam ([3H]FNM) to the alpha 3 beta 2 gamma 2 receptor combination in whole cell preparations. No effect or small increases in levels of unsaturated FFAs on [3H]FNM binding to alpha 1 beta x gamma 2 and alpha 2 beta x gamma 2 receptor combinations were observed, and weak effects (130% of control values) were detected using the alpha 5 beta 2 gamma 2 receptor combination. The saturated FFAs, stearic and palmitic acids, were without effect on [3H]FNM binding to any combination of receptor complexes. The hydroxylated unsaturated FFAs, ricinoleic and ricinelaidic acids, were shown to decrease the binding of [3H]FNM only if an alpha 1 beta 2 gamma 2 receptor combination was used. Given the heterogeneity of the GABAA/ benzodiazepine receptor subunit distribution in the CNS, the effects of FFAs on the benzodiazepine receptor can be assumed to vary at both cellular and regional levels.

Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction

DEFF Research Database (Denmark)

Taarning, Esben; Madsen, Robert

2008-01-01

A one-pot procedure is described for using alpha,beta-unsaturated aldehydes as olefin equivalents in the Diels-Alder reaction. The method combines the normal electron demand cycloaddition with aldehyde dienophiles and the rhodium-catalyzed decarbonylation of aldehydes to afford cyclohexenes...

Transition metal-free oxidation of benzylic alcohols to carbonyl compounds by hydrogen peroxide in the presence of acidic silica gel

Directory of Open Access Journals (Sweden)

Hossein Ghafuri

2015-01-01

Full Text Available Oxidation of alcohols to carbonyl compounds has become an important issue in the process industry as well as many other applications. In this method, various benzylic alcohols were successfully converted to corresponding aldehydes and ketones under transition metal-free condition using hydrogen peroxide in the presence of some amount of catalytic acidic silica gel. Silica gel is inexpensive and available. One of the most important features of this method is its short reaction time.

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method.

Science.gov (United States)

Black, Stuart; Ferrell, Jack R

2017-02-07

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls cause an increase in viscosity (often referred to as 'aging') during storage of bio-oils. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Additionally, carbonyls are also responsible for coke formation in bio-oil upgrading processes. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here, we present a modification of the traditional carbonyl oximation procedures that results in less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. While traditional carbonyl oximation methods occur at room temperature, the Faix method presented here occurs at an elevated temperature of 80 °C.

Protein carbonylation associated to high-fat, high-sucrose diet and its metabolic effects.

Science.gov (United States)

Méndez, Lucía; Pazos, Manuel; Molinar-Toribio, Eunice; Sánchez-Martos, Vanesa; Gallardo, José M; Rosa Nogués, M; Torres, Josep L; Medina, Isabel

2014-12-01

The present research draws a map of the characteristic carbonylation of proteins in rats fed high-caloric diets with the aim of providing a new insight of the pathogenesis of metabolic diseases derived from the high consumption of fat and refined carbohydrates. Protein carbonylation was analyzed in plasma, liver and skeletal muscle of Sprague-Dawley rats fed a high-fat, high-sucrose (HFHS) diet by a proteomics approach based on carbonyl-specific fluorescence-labeling, gel electrophoresis and mass spectrometry. Oxidized proteins along with specific sites of oxidative damage were identified and discussed to illustrate the consequences of protein oxidation. The results indicated that long-term HFHS consumption increased protein oxidation in plasma and liver; meanwhile, protein carbonyls from skeletal muscle did not change. The increment of carbonylation by HFHS diet was singularly selective on specific target proteins: albumin from plasma and liver, and hepatic proteins such as mitochondrial carbamoyl-phosphate synthase (ammonia), mitochondrial aldehyde dehydrogenase, argininosuccinate synthetase, regucalcin, mitochondrial adenosine triphosphate synthase subunit beta, actin cytoplasmic 1 and mitochondrial glutamate dehydrogenase 1. The possible consequences that these specific protein carbonylations have on the excessive weight gain, insulin resistance and nonalcoholic fatty liver disease resulting from HFHS diet consumption are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

DNA damage by carbonyl stress in human skin cells

International Nuclear Information System (INIS)

Roberts, Michael J.; Wondrak, Georg T.; Laurean, Daniel Cervantes; Jacobson, Myron K.; Jacobson, Elaine L.

2003-01-01

Reactive carbonyl species (RCS) are potent mediators of cellular carbonyl stress originating from endogenous chemical processes such as lipid peroxidation and glycation. Skin deterioration as observed in photoaging and diabetes has been linked to accumulative protein damage from glycation, but the effects of carbonyl stress on skin cell genomic integrity are ill defined. In this study, the genotoxic effects of acute carbonyl stress on HaCaT keratinocytes and CF3 fibroblasts were assessed. Administration of the α-dicarbonyl compounds glyoxal and methylglyoxal as physiologically relevant RCS inhibited skin cell proliferation, led to intra-cellular protein glycation as evidenced by the accumulation of N ε -(carboxymethyl)-L-lysine (CML) in histones, and caused extensive DNA strand cleavage as assessed by the comet assay. These effects were prevented by treatment with the carbonyl scavenger D-penicillamine. Both glyoxal and methylglyoxal damaged DNA in intact cells. Glyoxal caused DNA strand breaks while methylglyoxal produced extensive DNA-protein cross-linking as evidenced by pronounced nuclear condensation and total suppression of comet formation. Glycation by glyoxal and methylglyoxal resulted in histone cross-linking in vitro and induced oxygen-dependent cleavage of plasmid DNA, which was partly suppressed by the hydroxyl scavenger mannitol. We suggest that a chemical mechanism of cellular DNA damage by carbonyl stress occurs in which histone glycoxidation is followed by reactive oxygen induced DNA stand breaks. The genotoxic potential of RCS in cultured skin cells and its suppression by a carbonyl scavenger as described in this study have implications for skin damage and carcinogenesis and its prevention by agents selective for carbonyl stress

DNA damage by carbonyl stress in human skin cells

Energy Technology Data Exchange (ETDEWEB)

Roberts, Michael J.; Wondrak, Georg T.; Laurean, Daniel Cervantes; Jacobson, Myron K.; Jacobson, Elaine L

2003-01-28

Reactive carbonyl species (RCS) are potent mediators of cellular carbonyl stress originating from endogenous chemical processes such as lipid peroxidation and glycation. Skin deterioration as observed in photoaging and diabetes has been linked to accumulative protein damage from glycation, but the effects of carbonyl stress on skin cell genomic integrity are ill defined. In this study, the genotoxic effects of acute carbonyl stress on HaCaT keratinocytes and CF3 fibroblasts were assessed. Administration of the {alpha}-dicarbonyl compounds glyoxal and methylglyoxal as physiologically relevant RCS inhibited skin cell proliferation, led to intra-cellular protein glycation as evidenced by the accumulation of N{sup {epsilon}}-(carboxymethyl)-L-lysine (CML) in histones, and caused extensive DNA strand cleavage as assessed by the comet assay. These effects were prevented by treatment with the carbonyl scavenger D-penicillamine. Both glyoxal and methylglyoxal damaged DNA in intact cells. Glyoxal caused DNA strand breaks while methylglyoxal produced extensive DNA-protein cross-linking as evidenced by pronounced nuclear condensation and total suppression of comet formation. Glycation by glyoxal and methylglyoxal resulted in histone cross-linking in vitro and induced oxygen-dependent cleavage of plasmid DNA, which was partly suppressed by the hydroxyl scavenger mannitol. We suggest that a chemical mechanism of cellular DNA damage by carbonyl stress occurs in which histone glycoxidation is followed by reactive oxygen induced DNA stand breaks. The genotoxic potential of RCS in cultured skin cells and its suppression by a carbonyl scavenger as described in this study have implications for skin damage and carcinogenesis and its prevention by agents selective for carbonyl stress.

Inhibition of steroid 5 alpha-reductase by specific aliphatic unsaturated fatty acids.

Science.gov (United States)

Liang, T; Liao, S

1992-01-01

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells. PMID:1637346

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

Science.gov (United States)

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

2015-09-16

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

Some studies on tar pillets at Veraval coast (Gujarat)

Digital Repository Service at National Institute of Oceanography (India)

Kadam, A.N.

Infrared spectroscopic (IR) analysis indicated that the tar pillets contain saturated hydrocarbons particularly higher homologues of n-paraffins, unsaturated and carbonyl type of polar compounds. Gas chromatographic (GLC) fingerprint pattern...

REACTIONS OF 5-[1-(2-PHENYL)METHYLIDENE

African Journals Online (AJOL)

4-DIONES WITH SOME ORGANOMETALLIC REAGENTS. ... KEY WORDS: Imidazolidine-2,4-diones, a,b-Unsaturated carbonyl compounds, 1,2-Addition, conjugate addition, Grignard reagents, Lithium dibutylcuprate. Bull. Chem. Soc. Ethiop.

Polydiphenylacetylene with Schiff Base End Groups: Synthesis and Characterization

Science.gov (United States)

Kalinova, Radostina; Jossifov, Christo

The carbonyl-olefin exchange reaction is a new reaction between carbonyl group and olefin double bond, which has a formal similarity with the olefin metathesis - one carbon atom in the latter is replaced with an oxygen atom. Till now the new reaction is performed successfully only when the two functional groups (carbonyl group and olefin double bond) are in one molecule and are conjugated. The α, β-unsaturated carbonyl compounds (substituted propenones) are the compounds with such a structure. They polymerize giving substituted polyacetylenes. The chain propagation step of this polymerization is in fact the carbonyl-olefin exchange reaction. The question arises: is it possible the carbonyl-olefin exchange reaction to take place when the two functional groups are not in one molecule and are not conjugated, and could this reaction become an alternative of the existing carbonyl olefination reactions?

Optical chemical sensors for atmospheric pollutants based on nano porous materials: application to the formaldehyde and the other carbonyl compounds

International Nuclear Information System (INIS)

Paolacci, H.

2006-12-01

Formaldehyde, a well-identified indoor pollutant, was recently classified as carcinogenic. New regulations for the air quality are expected and therefore there is a need for low-cost sensors, sensitive and selective with a fast response time for the detection of formaldehyde at ppb level. In the present work, we had developed a chemical sensor based on nano-porous matrices doped with Fluoral-P and optical methods of detection. The nano-porous matrices, elaborated via the Sol-Gel process, display nano-pores whose cavity is tailored for the trapping of the targeted pollutant. They provide a first selectivity with the discrimination of the pollutants by their size. A second selectivity is obtained with a molecular probe, Fluoral-P, which reacts specifically with formaldehyde leading to the 3,5- di-acetyl-1,4-dihydro-lutidine (DDL). The kinetics of formation of DDL was studied as function of many parameters such as the concentration of Fluoral-P in the matrix, the pollutant content in gas mixture, the flow rate, the relative humidity of the gas mixtures and interference with other carbonylated compounds. The present chemical sensor can detect, via absorbance measurements, 2 ppb of formaldehyde within 30 min over a O to 60% relative humidity range. Moreover, to detect the total carbonylated compounds, we also explored the potentiality of a chemical sensor using, as a probe molecule, the 2'4-dinitro-phenyl-hydrazine which forms with these compounds the corresponding hydrazones derivatives. A patent was deposited for these two sensors. We have also developed a semi-miniaturized prototype for demonstration, using a flow cell, a miniaturized spectrophotometer, a light source and a lap-top. (author)

Conjugate additions of a simple monosilylcopper reagent with use of the CuI.DMS complex: stereoselectivities and a dramatic impact by DMS.

Science.gov (United States)

Dambacher, Jesse; Bergdahl, Mikael

2005-01-21

Conjugate additions utilizing the simple monosilylcuprate reagent Li[PhMe2SiCuI] to alpha,beta-unsaturated carbonyl compounds are described. The presence of dimethyl sulfide (DMS), either as a component originating from the (CuI)4(DMS)3 complex or as a solvent added, has an amazing influence on both chemical yield and the level of diastereomeric ratio (dr) of the products. Gilman-type silylcyanocuprates {Li(Ph2MeSi)2Cu/LiCN} have previously been used to guarantee good results in conjugate addition reactions. External additives such as HMPA, tributylphosphine, or dialkylzinc are not necessary in conjunction with the simple Li[PhMe2SiCuI] reagent. It is demonstrated that the monosilylcuprate reagent with DMS as the solvent is very useful with sterically hindered (beta,beta-disubstituted) enones, and provides very high yields of the beta-silylated 1,4-addition products. Since there is no oligomerization problem associated with the simple monosilylcuprate reagent, this reagent should be considered as a very useful 1,4-silyl donor to enals, enones, and enoates in conjugate addition reactions.

Time and dose effects of cigarette smoke and acrolein on protein carbonyl formation in HaCaT keratinocytes.

Science.gov (United States)

Avezov, K; Reznick, A Z; Aizenbud, D

2015-01-01

Cigarette smoke (CS) is an important environmental source of human exposure to a highly toxic and chemically active α,β-unsaturated aldehyde: acrolein. It is capable of causing protein carbonylation and dysfunction, especially in oral tissues of smokers, constantly exposed to CS toxic constituents. The foremost damage is considered to be cumulative, but even a short exposure can be potentially harmful. The objectives of the current study were to examine the short time and dose effects of direct CS and acrolein exposure on intracellular protein carbonylation in epithelial cells. HaCaT-keratinocytes were exposed to different doses of acrolein and whole phase CS using a unique smoking simulator apparatus that mimics the exposure in smokers. The rate of intracellular protein carbonyl modification was examined 10-60 min after the exposure by Western blot. In addition, the effect of pre-incubation with a thiol scavenger N-acetylcysteine (NAC) was also assessed. We found that intracellular protein carbonyls increased as fast as 10 min after CS exposure and their concentration doubled after 20 min, with a slight elevation afterwards. Also, carbonyl levels increased gradually as CS and acrolein doses were elevated. Addition of 1 mM NAC neutralized part of the damage. We conclude that CS and acrolein intracellular protein carbonylation is dose- and time- dependent. Even a short time exposure to CS and its aldehydic constituents can be potentially harmful.

Degradation of carbonyl hydroperoxides in the atmosphere and in combustion

KAUST Repository

Xing, Lili; Bao, Junwei Lucas; Wang, Zhandong; Zhang, Feng; Truhlar, Donald G.

2017-01-01

Oxygenates with carbonyl and hydroperoxy functional groups are important intermediates that are generated during the autooxidation of organic compounds in the atmosphere and during the autoignition of transport fuels. In the troposphere

Synthetic and mechanistic aspects of titanium-mediated carbonyl olefinations

Energy Technology Data Exchange (ETDEWEB)

Petasis, N.A.; Staszewski, J.P.; Hu, Yong-Han; Lu, Shao-Po [Univ. of Southern California, Los Angeles, CA (United States)

1995-12-31

A new method for the olefination of carbonyl compounds with dimethyl titanocene, and other related bishydrocarbyl titanocene derivatives has been recently developed in the author`s laboratories. This process is experimentally convenient and works with various types of carbonyl compounds, including aldehydes, ketones, esters, lactones, carbonates, anhydrides, amides, imides, lactams, thioesters, selenoesters, and acylsilanes. More recent studies have focused on the scope and utility of this reaction, including mechanistic studies and synthetic applications. In addition to varying the reaction conditions, the authors have examined several mixed titanocene derivatives and have found ways for carrying out this type of olefination at room temperature, such as the use of tris(trimethylsilyl) titanacyclobutene. The authors have also employed this reaction in the modification of carbohydrates and cyclobutenediones. This olefination was also followed-up with subsequent transformations to produce carbocycles and heterocycles, including tetrahydrofurans and tetrahydropyrans.

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

Science.gov (United States)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

Copper oxide as efficient catalyst for oxidative dehydrogenation of alcohols with air

DEFF Research Database (Denmark)

Poreddy, Raju; Engelbrekt, Christian; Riisager, Anders

2015-01-01

The oxidative dehydrogenation of alcohols to carbonyl compounds was studied using CuO nanoparticle catalysts prepared by solution synthesis in buffered media. CuO nanoparticles synthesized in N-cyclohexyl- 3-aminopropanesulfonic acid buffer showed high catalytic activity for the oxidation...... of benzylic, alicyclic and unsaturated alcohols to their corresponding carbonyl compounds with excellent selectivities. The observed trend in activity for conversion of substituted alcohols suggested a β-H elimination step to be involved, thus enabling a possible reaction mechanism for oxidative...... dehydrogenation of benzyl alcohols to be proposed. The use of CuO as an inexpensive and efficient heterogeneous catalyst under aerobic conditions provides a new noble metal-free and green reaction protocol for carbonyl compound synthesis....

Measurements of carbonyls in a 13-story building.

Science.gov (United States)

Báez, Armando P; Padilla, Hugo G; García, Rocío M; Belmont, Raúl D; Torres, Maria del Carmen B

2004-01-01

Formaldehyde and acetaldehyde are emitted by many mobile and stationary sources and secondary aldehydes are intermediates in the photo-oxidation of organic compounds in the atmosphere. These aldehydes are emitted indoors by many materials such as furniture, carpets, heating and cooling systems, an by smoking. Carbonyls, mainly formaldehyde and acetaldehyde, have been studied because of their adverse health effects. In addition, formaldehyde is a suspected carcinogen. Therefore, the concentrations of formaldehyde and acetaldehyde were determined to assess the inhalation exposure doses to carbonyls for people who work in a 13-story building and in order to evaluate the cancer hazard. Carbonyl compounds in indoor and outdoor air were measured at a 13-story building located in Mexico City. The mezzanine, fifth and tenth floors, and the third level-parking garage were selected for sampling. Samples were collected in two sampling periods, the first from April 20 to 29, 1998 and the second from December 1 to 20, 1998. Carbonyls were sampled by means of DNHP-coated cartridges at a flow rate of 1 l min(-1) from 9:00 to 19:00 hours, during 2-hour time intervals and analyzed by HPLC with hours, during 2-hour time intervals and analyzed by HPLC with UV/VIS detection. Mean carbonyl concentrations were highest in the 3rd level-parking garage, with the formaldehyde concentration being the highest ranging from 108 to 418 microg m(-3). In working areas, the highest carbonyl arithmetic mean concentrations (AM) were observed on the 5th floor. Acetone and formaldehyde concentrations were highest in April ranging from 161 to 348 microg m(-3) (AM = 226) and from 157 to 270 microg m(-3) (AM = 221), respectively. Propionaldehyde and butyraldehyde were present in smaller concentrations ranging from 2 to 25 and 1 to 28 microg m(-3), respectively, considering all the samples. Mean indoor/outdoor ratios of carbonyls ranged from 1.8 to 9.6. A reduction of inhalation exposure doses of 41% and

Ammonia synthesis in the presence of rhodium-ruthenium-iridium carbonyl clusters

International Nuclear Information System (INIS)

Fedoseev, I.V.; Solov'ev, N.V.

2007-01-01

Researches in the field of platinum metal coordination compounds, where nitrogen enters as a ligand in coordination sphere of metal, are discussed. Results of experiments on the ammonia synthesis during the CO+N 2 mixture passing through alkali solution containing mixture of carbonyl clusters of rhodium, ruthenium and iridium at atmospheric pressure are given. Technique of the experiment and steps of assumed reactions of nitrogen fixation by Rh, Ir and Ru carbonyl clusters are demonstrated [ru

Catalytic reactions of synthesis gas. Part 2. Methanol carbonylation and homologation

Energy Technology Data Exchange (ETDEWEB)

Niemelae, M.

1993-01-01

The aim of the review is to evaluate the applicability of methanol hydrocarbonylation as a second test reaction to study the nondissociative activation of CO by heterogeneous rhodium and cobalt catalysts. The main emphasis in methanol (hydro)carbonylation chemistry has been on homogeneous reactions. These systems have been seen advantageous in selectivity, activity and ease of modification. The heterogenization attempts have been carried out to obtain easier separation of the catalyst and the product. The activity of cobalt, rhodium and other metals supported on different materials have been studied in heterogeneous methanol (hydro)carbonylation. The observed activities have been considerably influenced by the support. The most effective catalyst support has been activated carbon. Good carbonylation activities and selectivities have also been observed in conjunction with zeolite supports. The literature study indicates that the typical experimental conditions of methanol (hydro)carbonylation do not exceed the constructional and operational limits of the available reactor system, i.e. 500 C and 50 bar. The reaction is suitable for testing Co and Rh precursors, since both cobalt and rhodium compounds have shown carbonylation activity.

Degradation of carbonyl hydroperoxides in the atmosphere and in combustion

KAUST Repository

Xing, Lili

2017-10-12

Oxygenates with carbonyl and hydroperoxy functional groups are important intermediates that are generated during the autooxidation of organic compounds in the atmosphere and during the autoignition of transport fuels. In the troposphere, the degradation of carbonyl hydroperoxides leads to low-vapor-pressure polyfunctional species that be taken into in cloud and fog droplets or to the formation of secondary organic aerosols (SOAs). In combustion, the fate of carbonyl hydroperoxides is important for the performance of advanced combustion engines, especially for autoignition. A key fate of the carbonyl hydroperoxides is reac-tion with OH radicals, for which kinetics data are experimentally unavailable. Here, we study 4-hydroperoxy-2-pentanone (CH3C(=O)CH2CH(OOH)CH3) as a model compound to clarify the kinetics of OH reactions with carbonyl hydroperoxides, in par-ticular H-atom abstraction and OH addition reactions. With a combination of electronic structure calculations, we determine previ-ously missing thermochemical data, and with multipath variational transition state theory (MP-VTST), a multidimensional tunnel-ing (MT) approximation, multiple-structure anharmonicity, and torsional potential anharmonicity we obtained much more accurate rate constants than the ones that can computed by conventional single-structure harmonic transition state theory (TST) and than the empirically estimated rate constants that are currently used in atmospheric and combustion modeling. The roles of various factors in determining the rates are elucidated. The pressure-dependent rate constants for the addition reaction are computed using system-specific quantum RRK theory. The calculated temperature range is 298-2400 K, and the pressure range is 0.01–100 atm. The accu-rate thermodynamic and kinetics data determined in this work are indispensable in the global modeling of SOAs in atmospheric science and in the detailed understanding and prediction of ignition properties of hydrocarbons

Simultaneous counter-flow of chlorinated volatile organic compounds across the saturated-unsaturated interface region of an aquifer.

Science.gov (United States)

Ronen, Daniel; Lev-Wiener, Hagit; Graber, Ellen R; Dahan, Ofer; Weisbrod, Noam

2010-04-01

Concentrations of chlorinated volatile organic compounds (Cl-VOCs) at the saturated-unsaturated interface region (SUIR; depth of approximately 18m) of a sandy phreatic aquifer were measured in two monitoring wells located 25m apart. The concentrations of the Cl-VOCs obtained above and below the water table along a 413-day period are interpreted to depict variable, simultaneous and independent movement of trichlorothene, tetrachloroethene, 1,1-dichloroethene, cis-1,2-dichloroethene, 1,1,1-trichloroethane, chloroform and 1,1-dichloroethane vapors in opposite directions across the SUIR. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Single-Step Access to Long-Chain α,ω-Dicarboxylic Acids by Isomerizing Hydroxycarbonylation of Unsaturated Fatty Acids

KAUST Repository

Goldbach, Verena

2016-11-09

Dicarboxylic acids are compounds of high value, but to date long-chain alpha,omega-dicarboxylic acids have been difficult to access in a direct way. Unsaturated fatty acids are ideal starting materials with their molecular structure of long methylene sequences and a carboxylate functionality, in addition to a double bond that offers itself for functionalization. Within this paper, we established a direct access to alpha,omega-dicarboxylic acids by combining isomerization and selective terminal carbonylation of the internal double bond with water as a nucleophile on unsaturated fatty acids. We identified the key elements of this reaction: a homogeneous reaction mixture ensuring sufficient contact between all reactants and a catalyst system allowing for activation of the Pd precursor under aqueous conditions. Experiments under pressure reactor conditions with [(dtbpx)Pd(OTf)(2)] as catalyst precursor revealed the importance of nucleophile and reactant concentrations and the addition of the diprotonated diphosphine ligand (dtbpxH(2))(OTf)(2) to achieve turnover numbers >120. A variety of unsaturated fatty acids, including a triglyceride, were converted to valuable long-chain dicarboxylic acids with high turnover numbers and selectivities for the linear product of >90%. We unraveled the activation pathway of the Pd-II precursor, which proceeds via a reductive elimination step forming a Pd species and oxidative addition of the diprotonated diphosphine ligand, resulting in the formation of the catalytically active Pd hydride species. Theoretical calculations identified the hydrolysis as the rate-determining step. A low nucleophile concentration in the reaction mixture in combination with this high energetic barrier limits the potential of this reaction. In conclusion, water can be utilized as a nucleophile in isomerizing functionalization reactions and gives access to long-chain dicarboxylic acids from a variety of unsaturated substrates. The activity of the catalytic

Biodegradation of vapor-phase toluene in unsaturated porous media: Column experiments

International Nuclear Information System (INIS)

Khan, Ali M.; Wick, Lukas Y.; Harms, Hauke; Thullner, Martin

2016-01-01

Biodegradation of organic chemicals in the vapor phase of soils and vertical flow filters has gained attention as promising approach to clean up volatile organic compounds (VOC). The drivers of VOC biodegradation in unsaturated systems however still remain poorly understood. Here, we analyzed the processes controlling aerobic VOC biodegradation in a laboratory setup mimicking the unsaturated zone above a shallow aquifer. The setup allowed for diffusive vapor-phase transport and biodegradation of three VOC: non-deuterated and deuterated toluene as two compounds of highly differing biodegradability but (nearly) identical physical and chemical properties, and MTBE as (at the applied experimental conditions) non-biodegradable tracer and internal control. Our results showed for toluene an effective microbial degradation within centimeter VOC transport distances despite high gas-phase diffusivity. Degradation rates were controlled by the reactivity of the compounds while oxic conditions were found everywhere in the system. This confirms hypotheses that vadose zone biodegradation rates can be extremely high and are able to prevent the outgassing of VOC to the atmosphere within a centimeter range if compound properties and site conditions allow for sufficiently high degradation rates. - Highlights: • The column setup allows resolving vapor-phase VOC concentration gradients at cm scale resolution. • Vapor-phase and liquid-phase concentrations are measured simultaneously. • Isotopically labelled VOC was used as reference species of low biodegradability. • Biodegradation rates in the unsaturated zone can be very high and act at a cm scale. • Unsaturated material can be an effective bio-barrier avoiding biodegradable VOC emissions. - Microbial degradation activity can be sufficient to remove VOC from unsaturated porous media after a few centimeter of vapor-phase diffusive transport and mayeffectively avoid atmospheric emissions.

Michael additions of thiocompounds to {alpha}, {beta}-unsaturated carbonyl compounds in aqueous media: stereoselectivity with unambiguous characterization by NMR

Energy Technology Data Exchange (ETDEWEB)

Almeida, Queli Aparecida Rodrigues de; Pereira, Maria Luiza de Oliveira; Coelho, Ricardo Bezerra; Kaiser, Carlos Roland; Jones Junior, Joel; Silva, Flavia Martins da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Organica]. E-mail: soa@iq.ufrj.br; Carvalho, Erika Martins de [Instituto de Tecnologia em Farmacos (Far-Manguinhos), Rio de Janeiro, RJ (Brazil)

2008-07-01

The reactions of crotonaldehyde (8) with thiophenol (2) and benzalacetone (10) with ethane-1,2- dithiol (11) yield Michael addition products. The reactions of thiophenol (2) with (R)-carvone (13) and (S)-perillaldehyde (15) lead to (2S,3R,5S)-5-isopropenyl-2-methyl-3-(phenylthio)cyclohexanone (14) and (1R,2R,4S)-4-isopropenyl-2-(phenylthio)cyclohexanecarbaldehyde (16), respectively. An unambiguous elucidation of the stereochemistry of 14 and 16 by NMR is also presented. (author)

Synthesis and Antifungal Activity of Musa Phytoalexins and Structural Analogs

Directory of Open Access Journals (Sweden)

Adriana Gallego

2000-07-01

Full Text Available Several perinaphthenone/phenylphenalenone compounds were synthesized to establish a relationship between structure and antifungal activity against Mycosphaerella fijiensis. Substitutions on the unsaturated carbonyl system or addition of a phenyl group reduced antibiotic activity.

Human carbonyl reductase 1 participating in intestinal first-pass drug metabolism is inhibited by fatty acids and acyl-CoAs.

Science.gov (United States)

Hara, Akira; Endo, Satoshi; Matsunaga, Toshiyuki; El-Kabbani, Ossama; Miura, Takeshi; Nishinaka, Toru; Terada, Tomoyuki

2017-08-15

Human carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, reduces a variety of carbonyl compounds including endogenous isatin, prostaglandin E 2 and 4-oxo-2-nonenal. It is also a major non-cytochrome P450 enzyme in the phase I metabolism of carbonyl-containing drugs, and is highly expressed in the intestine. In this study, we found that long-chain fatty acids and their CoA ester derivatives inhibit CBR1. Among saturated fatty acids, myristic, palmitic and stearic acids were inhibitory, and stearic acid was the most potent (IC 50 9µM). Unsaturated fatty acids (oleic, elaidic, γ-linolenic and docosahexaenoic acids) and acyl-CoAs (palmitoyl-, stearoyl- and oleoyl-CoAs) were more potent inhibitors (IC 50 1.0-2.5µM), and showed high inhibitory selectivity to CBR1 over its isozyme CBR3 and other SDR superfamily enzymes (DCXR and DHRS4) with CBR activity. The inhibition by these fatty acids and acyl-CoAs was competitive with respect to the substrate, showing the K i values of 0.49-1.2µM. Site-directed mutagenesis of the substrate-binding residues of CBR1 suggested that the interactions between the fatty acyl chain and the enzyme's Met141 and Trp229 are important for the inhibitory selectivity. We also examined CBR1 inhibition by oleic acid in cellular levels: The fatty acid effectively inhibited CBR1-mediated 4-oxo-2-nonenal metabolism in colon cancer DLD1 cells and increased sensitivity to doxorubicin in the drug-resistant gastric cancer MKN45 cells that highly express CBR1. The results suggest a possible new food-drug interaction through inhibition of CBR1-mediated intestinal first-pass drug metabolism by dietary fatty acids. Copyright © 2017 Elsevier Inc. All rights reserved.

Protein carbonylation in plants

DEFF Research Database (Denmark)

Møller, Ian Max; Havelund, Jesper; Rogowska-Wrzesinska, Adelina

2017-01-01

This chapter provides an overview of the current knowledge on protein carbonylation in plants and its role in plant physiology. It starts with a brief outline of the turnover and production sites of reactive oxygen species (ROS) in plants and the causes of protein carbonylation. This is followed...... by a description of the methods used to study protein carbonylation in plants, which is also very brief as the methods are similar to those used in studies on animals. The chapter also focuses on protein carbonylation in plants in general and in mitochondria and in seeds in particular, as case stories where...... specific carbonylated proteins have been identified. Protein carbonylation appears to accumulate at all stages of seed development and germination investigated to date. In some cases, such as seed aging, it is probably simply an accumulation of oxidative damage. However, in other cases protein...

(E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.

Science.gov (United States)

Shi, Renyi; Zhang, Hua; Lu, Lijun; Gan, Pei; Sha, Yuchen; Zhang, Heng; Liu, Qiang; Beller, Matthias; Lei, Aiwen

2015-02-21

A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO.

Validation of protein carbonyl measurement

DEFF Research Database (Denmark)

Augustyniak, Edyta; Adam, Aisha; Wojdyla, Katarzyna

2015-01-01

Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial...... protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5min of UV irradiation irrespective of method used. After irradiation for 15min, less oxidation was detected by half of the laboratories than after 5min...... irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated...

A Mild and Convenient Method for the Reduction of Carbonyl Compounds with NaBH4 in the Presence of Catalytic Amounts of MoCl5

International Nuclear Information System (INIS)

Zeynizadeh, Behzad; Yahyaei, Saiedeh

2003-01-01

NaBH 4 with catalytic amounts of MoCl 5 can readily reduce a variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and conjugated enones to their corresponding alcohols in good to excellent yields. Reduction reactions were performed under aprotic condition in CH 3 CN at room temperature or reflux. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing system

Stereoselective Carbonyl Olefination with Fluorosulfoximines: Facile Access to Z or E Terminal Monofluoroalkenes.

Science.gov (United States)

Liu, Qinghe; Shen, Xiao; Ni, Chuanfa; Hu, Jinbo

2017-01-09

Terminal monofluoroalkenes are important structural motifs in the design of bioactive compounds, such as homeostasis regulators and mechanism-based enzyme inhibitors. However, it is difficult to control the stereoselectivity of known carbonyl olefination reactions, and olefin metathesis is limited to disubstituted terminal monofluoroalkenes. Although sulfoximines have been used extensively in organic synthesis, reports on their use in carbonyl olefination reactions have not appeared to date. Herein, we report highly stereoselective carbonyl monofluoroolefination with a fluorosulfoximine reagent. The potential of this method is demonstrated by the synthesis of MDL 72161 and by the late-stage monofluoromethylenation of complex molecules, such as haloperidol and steroid derivatives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transition metal catalyzed carbonylation reactions carbonylative activation of C-X bonds

CERN Document Server

Beller, Matthias

2014-01-01

This book provides students and researchers in organic synthesis with a detailed discussion of carbonylation from the basics through to applications. It discusses the past, present and future of carbonylation reactions.

Heat capacity anomalies associated with structural transformations in. beta. -W and perovskite compounds

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, R [Brookhaven National Lab., Upton, NY; Ho, J C

1977-01-01

The similarity of the heat capacity anomalies, often observed with structural transformations driven by soft phonons, in both ..beta..-W and perovskite compounds is discussed referring to our recent work on V/sub 3/Si and RbCaF/sub 3/.

New method to determine the total carbonyl functional group content in extractable particulate organic matter by tandem mass spectrometry.

Science.gov (United States)

Dron, J; Zheng, W; Marchand, N; Wortham, H

2008-08-01

A functional group analysis method was developed to determine the quantitative content of carbonyl functional groups in atmospheric particulate organic matter (POM) using constant neutral loss scanning-tandem mass spectrometry (CNLS-MS/MS). The neutral loss method consists in monitoring the loss of a neutral fragment produced by the fragmentation of a precursor ion in a collision cell. The only ions detected are the daughter ions resulting from the loss of the neutral fragment under study. Then, scanning the loss of a neutral fragment characteristic of a functional group enables the selective detection of the compounds bearing the chemical function under study within a complex mixture. The selective detection of carbonyl functional groups was achieved after derivatization with pentafluorophenylhydrazine (PFPH) by monitoring the neutral loss of C(6)F(5)N (181 amu), which was characteristic of a large panel of derivatized carbonyl compounds. The method was tested on 25 reference mixtures of different composition, all containing 24 carbonyl compounds at randomly determined concentrations. The repeatability and calibration tests were satisfying as they resulted in a relative standard deviation below 5% and a linear range between 0.01 and 0.65 mM with a calculated detection limit of 0.0035 mM. Also, the relative deviation induced by changing the composition of the mixture while keeping the total concentration of carbonyl functional groups constant was less than 20%. These reliability experiments demonstrate the high robustness of the developed procedure for accurate carbonyl functional group measurement, which was applied to atmospheric POM samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

Reaction between phenyl derivatives of lanthanides and carbonyl compounds

International Nuclear Information System (INIS)

Sigalov, A.B.; Petrov, Eh.S.; Rybakova, L.F.; Beletskaya, I.P.

1983-01-01

Reactions of PhLnI (Ln=Yb, Eu, Sm, Ce) with α, β-unsaturated ketons (trans-chalcone and benzalacetone) are considered as well as with 9-fluorene and benzophenone. The regioselectivity of the reaction of PhLnI addition to enones is compared with similar reactions of PhMgX and PhLi. The reaction between PhLnI and trans-chalcone proceeds regiospecifically as 1, 2-addition in contrast with reactions of PhMgI and PhLi. A new reaction of lanthanide carbinolate deoxygenation under the effect of reducers was found. The reaction product yields are presented

Interaction of tertiary phosphines with lignin-type, alpha,beta-unsaturated aldehydes in water.

Science.gov (United States)

Moiseev, Dmitry V; Patrick, Brian O; James, Brian R; Hu, Thomas Q

2007-10-29

To learn more about the bleaching action of pulps by (hydroxymethyl)phosphines, lignin chromophores, such as the alpha,beta-unsaturated aromatic aldehydes, sinapaldehyde, coniferylaldehyde, and coumaraldehyde, were reacted with the tertiary phosphines R2R'P [R = R' = Me, Et, (CH2)3OH, iPr, cyclo-C6H11, (CH2)2CN; R = Me or Et, R' = Ph; R = Ph, R' = Me, m-NaSO3-C6H4] in water at room temperature under argon. In all cases, initial nucleophilic attack of the phosphine occurs at the activated C=C bond to form a zwitterionic monophosphonium species. With the phosphines PR3 [R = Me, Et, (CH2)3OH] and with R2R'P (R = Me or Et, R' = Ph), the zwitterion undergoes self-condensation to give a bisphosphonium zwitterion that can react with aqueous HCl to form the corresponding dichloride salts (as a mixture of R,R- and S,S-enantiomers); X-ray structures are presented for the bisphosphonium chlorides synthesized from the Et3P and Me3P reactions with sinapaldehyde. With the more bulky phosphines, iPr3P, MePPh2, (cyclo-C6H11)3P, and Na[Ph2P(m-SO3-C6H4)], only an equilibrium of the monophosphonium zwitterion with the reactant aldehyde is observed. The weakly nucleophilic [NC(CH2)2]3P does not react with sinapaldehyde. An analysis of some exceptional 1H NMR data within the prochiral phosphorus centers of the bisphosphonium chlorides is also presented.

Seasonal evaluation of disinfection by-products throughout two full-scale drinking water treatment plants.

Science.gov (United States)

Zhong, Xin; Cui, Chongwei; Yu, Shuili

2017-07-01

Carbonyl compounds can occur alpha-hydrogens or beta-diketones substitution reactions with disinfectants contributed to halogenated by-products formation. The objective of this research was to study the occurrence and fate of carbonyl compounds as ozonation by-products at two full-scale drinking water treatment plants (DWTPs) using different disinfectants for one year. The quality of the raw water used in both plants was varied according to the season. The higher carbonyl compounds concentrations were found in raw water in spring. Up to 15 (as the sum of both DWTPs) of the 24 carbonyl compounds selected for this work were found after disinfection. The dominant carbonyl compounds were formaldehyde, glyoxal, methyl-glyoxal, fumaric, benzoic, protocatechuic and 3-hydroxybenzoic acid at both DWTPs. In the following steps in each treatment plant, the concentration patterns of these carbonyl compounds differed depending on the type of disinfectant applied. Benzaldehyde was the only aromatic aldehyde detected after oxidation with ozone in spring. As compared with DWTP 1, five new carbonyl compounds were formed (crotonaldehyde, benzaldehyde, formic, oxalic and malonic acid) disinfection by ozone, and the levels of the carbonyl compounds increased. In addition, pre-ozonation (PO) and main ozonation (OZ) increased the levels of carbonyl compounds, however coagulation/flocculation (CF), sand filtration (SF) and granular activated carbon filtration (GAC) decreased the levels of carbonyl compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS.

Science.gov (United States)

Brandão, Pedro Francisco; Ramos, Rui Miguel; Almeida, Paulo Joaquim; Rodrigues, José António

2017-02-08

A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

The interaction of metal carbonyl compounds with organic polymers and monomers

OpenAIRE

Lyons, Michael P.

1993-01-01

The photochemistry of W(CO)6, Mo(CO)6, and Cr(CO)6 in the presence of monomeric and polymeric triphenylphosphine ligands was investigated in toluene solution, using laser flash photolysis with 355nm excitation. The mechanism and kinetics of interaction of the primary photoproducts M(CO)5(toluene) (M = W, Mo, or Cr) with the various monomeric ligands were investigated. Interaction of the metal carbonyl photofragments with various homopolymers is also discussed. The polymerisation methods used ...

Hydrogenation of the alpha,beta-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and Prenal over Pt Single Crystals: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

Energy Technology Data Exchange (ETDEWEB)

Kliewer, C.J.; Somorjai, G.A.

2008-11-26

Sum-frequency generation vibrational spectroscopy (SFG-VS) and kinetic measurements using gas chromatography have been used to study the surface reaction intermediates during the hydrogenation of three {alpha},{beta}-unsaturated aldehydes, acrolein, crotonaldehyde, and prenal, over Pt(111) at Torr pressures (1 Torr aldehyde, 100 Torr hydrogen) in the temperature range of 295K to 415K. SFG-VS data showed that acrolein has mixed adsorption species of {eta}{sub 2}-di-{sigma}(CC)-trans, {eta}{sub 2}-di-{sigma}(CC)-cis as well as highly coordinated {eta}{sub 3} or {eta}{sub 4} species. Crotonaldehyde adsorbed to Pt(111) as {eta}{sub 2} surface intermediates. SFG-VS during prenal hydrogenation also suggested the presence of the {eta}{sub 2} adsorption species, and became more highly coordinated as the temperature was raised to 415K, in agreement with its enhanced C=O hydrogenation. The effect of catalyst surface structure was clarified by carrying out the hydrogenation of crotonaldehyde over both Pt(111) and Pt(100) single crystals while acquiring the SFG-VS spectra in situ. Both the kinetics and SFG-VS showed little structure sensitivity. Pt(100) generated more decarbonylation 'cracking' product while Pt(111) had a higher selectivity for the formation of the desired unsaturated alcohol, crotylalcohol.

Unsaturated compounds induce up-regulation of CD86 on dendritic cells in the in vitro sensitization assay LCSA.

Science.gov (United States)

Frohwein, Thomas Armin; Sonnenburg, Anna; Zuberbier, Torsten; Stahlmann, Ralf; Schreiner, Maximilian

2016-04-01

Unsaturated compounds are known to cause false-positive reactions in the local lymph node assay (LLNA) but not in the guinea pig maximization test. We have tested a panel of substances (succinic acid, undecylenic acid, 1-octyn-3-ol, fumaric acid, maleic acid, linoleic acid, oleic acid, alpha-linolenic acid, squalene, and arachidonic acid) in the loose-fit coculture-based sensitization assay (LCSA) to evaluate whether unspecific activation of dendritic cells is a confounder for sensitization testing in vitro. Eight out of 10 tested substances caused significant up-regulation of CD86 on dendritic cells cocultured with keratinocytes and would have been classified as sensitizers; only succinic acid was tested negative, and squalene had to be excluded from data analysis due to poor solubility in cell culture medium. Based on human data, only undecylenic acid can be considered a true sensitizer. The true sensitizing potential of 1-octyn-3-ol is uncertain. Fumaric acid and its isomer maleic acid are not known as sensitizers, but their esters are contact allergens. A group of 18- to 20-carbon chain unsaturated fatty acids (linoleic acid, oleic acid, alpha-linolenic acid, and arachidonic acid) elicited the strongest reaction in vitro. This is possibly due to the formation of pro-inflammatory lipid mediators in the cell culture causing nonspecific activation of dendritic cells. In conclusion, both the LLNA and the LCSA seem to provide false-positive results for unsaturated fatty acids. The inclusion of T cells in dendritic cell-based in vitro sensitization assays may help to eliminate false-positive results due to nonspecific dendritic cell activation. This would lead to more accurate prediction of sensitizers, which is paramount for consumer health protection and occupational safety.

Catalytic Intermolecular Cross-Couplings of Azides and LUMO-Activated Unsaturated Acyl Azoliums

KAUST Repository

Li, Wenjun

2017-02-15

An example for the catalytic synthesis of densely functionalized 1,2,3-triazoles through a LUMO activation mode has been developed. The protocol is enabled by intermolecular cross coupling reactions of azides with in situ-generated alpha,beta-unsaturated acyl azoliums. High yields and broad scope as well as the investigation of reaction mechanism are reported.

Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China

Directory of Open Access Journals (Sweden)

Yan-Yang Lu

2016-06-01

Full Text Available An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs and carbonyl compounds (CCs in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, and isovaleraldehyde were relatively abundant in the cabins. Time was found to affect the emissions of the contaminants in the coaches. Except for benzaldehyde, valeraldehyde and benzene, the highest in-vehicle concentrations of VOCs and CCs were observed on the 15th day after coming off the assembly line, and the concentrations exhibited an approximately inverted U-shaped pattern as a function of time. Interestingly, this study also showed that the interior temperature of the coaches significantly affected the VOCs emissions from the interior materials, whereas the levels of CCs were mainly influenced by the relative humidity within the coaches. In China, guidelines and regulations for the in-vehicle air quality assessment of the coaches have not yet been issued. The results of this study provide further understanding of the in-vehicle air quality of air-conditioned coaches and can be used in the development of both specific and general rules regarding medium- and large-size coaches.

Novel α, β-Unsaturated Sophoridinic Derivatives: Design, Synthesis, Molecular Docking and Anti-Cancer Activities

Directory of Open Access Journals (Sweden)

Yiming Xu

2017-11-01

Full Text Available Using sophoridine 1 and chalcone 3 as the lead compounds, a series of novel α, β-unsaturated sophoridinic derivatives were designed, synthesized, and evaluated for their in vitro cytotoxicity. Structure-activity relationship (SAR analysis indicated that introduction of α, β-unsaturated ketone moiety and heterocyclic group might significantly enhance anticancer activity. Among the compounds, 2f and 2m exhibited potential effects against HepG-2 and CNE-2 human cancer cell lines. Furthermore, molecular docking studies were performed to understand possible docking sites of the molecules on the target proteins and the mode of binding. This work provides a theoretical basis for structural optimizations and exploring anticancer pathways of this kind of compound.

Cytoprotective Effects of Pumpkin (Cucurbita Moschata) Fruit Extract against Oxidative Stress and Carbonyl Stress.

Science.gov (United States)

Shayesteh, Reyhaneh; Kamalinejad, Mohammad; Adiban, Hasan; Kardan, Azin; Keyhanfar, Fariborz; Eskandari, Mohammad Reza

2017-10-01

Background Diabetes mellitus is a chronic endocrine disorder that is associated with significant mortality and morbidity due to microvascular and macrovascular complications. Diabetes complications accompanied with oxidative stress and carbonyl stress in different organs of human body because of the increased generation of free radicals and impaired antioxidant defense systems. In the meantime, reactive oxygen species (ROS) and reactive carbonyl species (RCS) have key mediatory roles in the development and progression of diabetes complications. Therapeutic strategies have recently focused on preventing such diabetes-related abnormalities using different natural and chemical compounds. Pumpkin ( Cucurbita moschata ) is one of the most important vegetables in the world with a broad-range of pharmacological activities such as antihyperglycemic effect. Methods In the present study, the cytoprotective effects of aqueous extract of C. moschata fruit on hepatocyte cytotoxicity induced by cumene hydroperoxide (oxidative stress model) or glyoxal (carbonylation model) were investigated using freshly isolated rat hepatocytes. Results The extract of C. moschata (50 μg/ml) excellently prevented oxidative and carbonyl stress markers, including hepatocyte lysis, ROS production, lipid peroxidation, glutathione depletion, mitochondrial membrane potential collapse, lysosomal damage, and cellular proteolysis. In addition, protein carbonylation was prevented by C. moschata in glyoxal-induced carbonyl stress. Conclusion It can be concluded that C. moschata has cytoprotective effects in oxidative stress and carbonyl stress models and this valuable vegetable can be considered as a suitable herbal product for the prevention of toxic subsequent of oxidative stress and carbonyl stress seen in chronic hyperglycemia. © Georg Thieme Verlag KG Stuttgart · New York.

Enantioselective conjugate radical addition to alpha'-hydroxy enones.

Science.gov (United States)

Lee, Sunggi; Lim, Chae Jo; Kim, Sunggak; Subramaniam, Rajesh; Zimmerman, Jake; Sibi, Mukund P

2006-09-14

Enantioselective conjugate radical addition to alpha'-hydroxy alpha,beta-unsaturated ketones, compounds containing bidentate donors, has been investigated. It has been found that radical additions to alpha'-hydroxy alpha,beta-unsaturated ketones in the presence of Mg(NTf2)2 and bisoxazoline ligand 5a proceeded cleanly, yielding the addition products in high chemical yields and good enantiomeric excesses.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, P.J. van; Cnubben, N.H.P.

2007-01-01

Curcumin, an α,β-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional 1H NMR analysis, and

Modelling flow through unsaturated zones: Sensitivity to unsaturated ...

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

soil properties are studied by varying the unsaturated parameters α and n over a wide range. ... Keywords. Unsaturated zone; capillary fringe; finite element method. ... and radioactive wastes. Several .... The length (L) of the soil sample is 1 m.

A Mild and Convenient Method for the Reduction of Carbonyl Compounds with NaBH{sub 4} in the Presence of Catalytic Amounts of MoCl{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Zeynizadeh, Behzad; Yahyaei, Saiedeh [Urmia University, Urmia (Iran, Islamic Republic of)

2003-11-15

NaBH{sub 4} with catalytic amounts of MoCl{sub 5} can readily reduce a variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and conjugated enones to their corresponding alcohols in good to excellent yields. Reduction reactions were performed under aprotic condition in CH{sub 3}CN at room temperature or reflux. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing system.

Influence of the Dielectric Medium on the Carbonyl Infrared Absorption Peak of Acetylferrocene

Directory of Open Access Journals (Sweden)

F. López-Linares

2005-02-01

Full Text Available The solvent effect on the position of the carbonyl vibrational stretching ofacetylferrocene in aprotic media was studied in this work. The solvent-induced shifts in thisorganometallic compound were interpreted in terms of the alternative reaction field model(SCRF-MO proposed by Kolling. In contrast to the established trends for carbonyl groupsin organic systems, the results suggest that the continuum models for the reaction field arenot adequate and that the influence of dipolarity-polarizability described by aninhomogeneous coupling function θ (ε L(n 2 that assumes optical dielectric saturation isresponsible for the carbonyl band shift and, there is empirical evidence that the effect offield-induced intermolecular interaction on band shift, interpreted in terms of the van derWaals forces from the solvent, have a important contribution to this phenomena.

Oxidative Modification of Blood Serum Proteins in Multiple Sclerosis after Interferon Beta and Melatonin Treatment

Directory of Open Access Journals (Sweden)

Monika Adamczyk-Sowa

2017-01-01

Full Text Available Multiple sclerosis (MS is a disease involving oxidative stress (OS. This study was aimed at examination of the effect of melatonin supplementation on OS parameters, especially oxidative protein modifications of blood serum proteins, in MS patients. The study included 11 control subjects, 14 de novo diagnosed MS patients with the relapsing-remitting form of MS (RRMS, 36 patients with RRMS receiving interferon beta-1b (250 μg every other day, and 25 RRMS patients receiving interferon beta-1b plus melatonin (5 mg daily. The levels of N′-formylkynurenine, kynurenine, dityrosine, carbonyl groups, advanced glycation products (AGEs, advanced oxidation protein products (AOPP, and malondialdehyde were elevated in nontreated RRSM patients. N′-Formylkynurenine, kynurenine, AGEs, and carbonyl contents were decreased only in the group treated with interferon beta plus melatonin, while dityrosine and AOPP contents were decreased both in the group of patients treated with interferon beta and in the group treated with interferon beta-1b plus melatonin. These results demonstrate that melatonin ameliorates OS in MS patients supporting the view that combined administration of interferon beta-1b and melatonin can be more effective in reducing OS in MS patients than interferon beta-1b alone.

Lewis acid tuned facial stereodivergent HDA reactions using beta-substituted N-vinyloxazolidinones.

Science.gov (United States)

Gohier, Frédéric; Bouhadjera, Keltoum; Faye, Djibril; Gaulon, Catherine; Maisonneuve, Vincent; Dujardin, Gilles; Dhal, Robert

2007-01-18

The [4 + 2] acido-catalyzed heterocycloaddition between new beta-substituted N-vinyl-1,3-oxazolidin-2-ones (with R' = Me, Ar, CH2 Ar) and beta,gamma-unsaturated alpha-ketoesters (R = Ar) afforded heteroadducts with high levels of endo and facial selectivities. A complete reversal of facial differentiation was achieved by varying the Lewis acid, leading to the stereoselective formation of either endo-alpha or endo-beta adducts. [reaction: see text].

Synthesis of carba sugars from aldonolactones. Part IV. Stereospecific synthesis of carbaheptopyranoses by radical-induced carbocyclisation of 2,3-unsaturated octonolactones

DEFF Research Database (Denmark)

Wagner, Sussi Holstein; Lundt, Inge

2001-01-01

Three new carbaheptopyranoses, 6-deoxy-5a-carba-beta -L-gulo- (8), 5a-carba-D-glycero-beta -D-ido- (22) and 5a-carba-L-glycero-alpha -L-galacto-heptopyranose (25), have been prepared from 8-bromo-8-deoxy-2,3-unsaturated octono-1,4-lactones with L-galacto-, D-gluco- and D-manno-configuration, resp...

α,β-Unsaturated monoterpene acid glucose esters: structural diversity, bioactivities and functional roles.

Science.gov (United States)

Goodger, Jason Q D; Woodrow, Ian E

2011-12-01

The glycosylation of lipophilic small molecules produces many important plant secondary metabolites. The majority of these are O-glycosides with relatively fewer occurring as glucose esters of aromatic or aliphatic acids. In particular, monoterpene acid glucose esters have much lower structural diversity and distribution compared to monoterpene glycosides. Nevertheless, there have been over 20 monoterpene acid glucose esters described from trees in the genus Eucalyptus (Myrtaceae) in recent years, all based on oleuropeic acid, menthiafolic acid or both. Here we review all of the glucose esters containing these monoterpenoids identified in plants to date. Many of the compounds contain phenolic aglycones and all contain at least one α,β-unsaturated carbonyl, affording a number of important potential therapeutic reactivities such as anti-tumor promotion, carcinogenesis suppression, and anti-oxidant and anti-inflammatory activities. Additional properties such as cytotoxicity, bitterness, and repellency are suggestive of a role in plant defence, but we also discuss their localization to the exterior of foliar secretory cavity lumina, and suggest they may also protect secretory cells from toxic terpenes housed within these structures. Finally we discuss how the use of a recently developed protocol to isolate secretory cavities in a functional state could be used in conjunction with systems biology approaches to help characterize their biosynthesis and roles in plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Metal-Free Catalytic Enantioselective C–B Bond Formation: (Pinacolato)boron Conjugate Additions to α,β-Unsaturated Ketones, Esters, Weinreb Amides and Aldehydes Promoted by Chiral N-Heterocyclic Carbenes

Science.gov (United States)

Wu, Hao; Radomkit, Suttipol; O’Brien, Jeannette M.; Hoveyda, Amir H.

2012-01-01

The first broadly applicable metal-free enantioselective method for boron conjugate addition (BCA) to α,β-unsaturated carbonyls is presented. The C–B bond forming reactions are promoted in the presence of 2.5–7.5 mol % of a readily accessible C1-symmetric chiral imidazolinium salt, which is converted, in situ, to the catalytically active diastereo- and enantiomerically pure N-heterocyclic carbene (NHC) by the common organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu). In addition to the commercially available bis(pinacolato)diboron [B2(pin)2], and in contrast to reactions with the less sterically demanding achiral NHCs, the presence of MeOH is required for high efficiency. Acyclic and cyclic α,β-unsaturated ketones, as well as acyclic esters, Weinreb amides and aldehydes can serve as suitable substrates; the desired β-boryl carbonyls are isolated in up to 94% yield and >98:2 enantiomer ratio (er). Transformations are often carried out at ambient temperature. In certain cases, such as when the relatively less reactive unsaturated amides are used, elevated temperatures are required (50–66 °C); nonetheless, reactions remain highly enantioselective. The utility of the NHC-catalyzed method is demonstrated through comparison with the alternative Cu-catalyzed protocols; in cases involving a polyfunctional substrate, unique profiles in chemoselectivity are exhibited by the metal-free approach (e.g., conjugate addition vs reaction with an alkyne, allene or aldehyde). PMID:22559866

Protein carbonylation, protein aggregation and neuronal cell death in a murine model of multiple sclerosis

Science.gov (United States)

Dasgupta, Anushka

/spatial relationship between carbonylation, protein aggregation and cellular apoptosis. Furthermore, the effectiveness of the carbonyl scavenger hydralazine, histidine hydrazide and methoxylamine at preventing cell death identifies protein carbonyls as the toxic species. Experiments using well-characterized apoptosis inhibitors place protein carbonylation downstream of the mitochondrial transition pore opening and upstream of caspase activation. These in vitro studies demonstrate for the first time a causal relationship between carbonylation, protein aggregation and apoptosis of neurons undergoing oxidative damage. This relationship was further strengthened with the experiments carried out in chapter 4, which show that inhibition of protein aggregation with congo red (CR) or 2-hydroxypropyl beta-cyclodextrin (HPCD) significantly reduced neuronal cell death without affecting the levels of oxidized proteins. Interestingly, large, juxta-nuclear aggregates are not formed upon GSH depletion, suggesting that the small protein aggregates are the cytotoxic species. Together, our data suggest that protein carbonylation causes protein aggregation to mediate neuronal apoptosis in vitro and that a similar mechanism might be contributing to neuronal/glial apoptosis in EAE. These studies provide the basis for testing protein carbonylation scavengers and protein aggregation inhibitors for the treatment of inflammatory demyelinating disorders.

Antiprotozoal Activity of α,β-Unsaturated δ-Lactones: Promising ...

African Journals Online (AJOL)

The parasite resistance and side effects of drugs used to treat protozoal diseases have led to the search for new therapies, both natural and synthetic. Studies have shown that various α,β-unsaturated δ-lactones displayed high antiprotozoal activity and thus are promising compounds for new drug discovery and ...

Mechanisms for formation of organic acids in gas-phase reactions of ozone and hydroxyl radical with dialkenes and unsaturated carbonyls

Science.gov (United States)

Chien, Chao-Jung

2001-07-01

Carboxylic acids are ubiquitous throughout the troposphere and may contribute significant fractions of the free acidity in some remote areas. One of the important sources of these carboxylic acids is thought to be photochemical transformation of biogenic hydrocarbons such as isoprene. For the work reported here, atmospheric samples from University of North Carolina dual outdoor environmental chamber under simulated urban atmospheric conditions were analyzed for carboxylic acids. Both OH radicals and O3 initiated photooxidation reaction experiments were performed for isoprene, along with its structural analogs, 1,3-butadiene and 2,3-dimethyl-1,3-butadiene, and their primary photooxidation products, methacrolein, acrolein, and methyl vinyl ketone. Among the detected carboxylic acids were formic, acetic, and several multifunctional carboxylic acids, including methacrylic, acrylic, glyoxylic, and glycolic acids. Quantification of most carboxylic acid products was also established. Formation yields of carboxylic acids from the reactions of O3 with studied compounds were determined, and time-concentration series of the reactants and carboxylic acid products were measured to facilitate mechanism formulation. While the reaction mechanisms of Criegee biradicals arising from decomposition of primary ozonides are proposed to account for the observed carboxylic acid products in the ozonolysis of unsaturated hydrocarbons, reactions of peroxy acyl radicals with HO2 and/or other peroxy radicals are thought to be responsible for the formation of carboxylic acids during the OH-initiated reactions in the presence of NOx. In this study, smog chamber simulations have also been performed for selected compounds using Morpho, a photochemical kinetic simulation software package. Explicit photochemical mechanisms with O 3 and OH radicals that lead to formation of carboxylic acids were elaborated and implemented, and the simulation results were compared with those from other chemical

Quantification of Carbonyl Compounds Generated from Ozone-Based Food Colorants Decomposition Using On-Fiber Derivatization-SPME-GC-MS

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Wenda Zhu

2014-12-01

Full Text Available Fruit leathers (FLs production produces some not-to-specification material, which contains valuable ingredients like fruit pulp, sugars and acidulates. Recovery of FL for product recycling requires decolorization. In earlier research, we proved the efficiency of an ozone-based decolorization process; however, it produces carbonyls as major byproducts, which could be of concern. A headspace solid-phase microextraction with on-fiber derivatization followed by gas chromatography-mass spectrometry was developed for 10 carbonyls analysis in ozonated FL solution/suspension. Effects of dopant concentration, derivatization temperature and time were studied. The adapted method was used to analyze ozonated FL solution/suspension samples. Dopant concentration and derivatization temperature were optimized to 17 mg/mL and 60 °C, respectively. Competitive extraction was studied, and 5 s extraction time was used to avoid non-linear derivatization of 2-furfural. The detection limits (LODs for target carbonyls ranged from 0.016 and 0.030 µg/L. A much lower LOD (0.016 ppb for 2-furfural was achieved compared with 6 and 35 ppb in previous studies. Analysis results confirmed the robustness of the adapted method for quantification of carbonyls in recycled process water treated with ozone-based decolorization. Ethanal, hexanal, 2-furfural, and benzaldehyde were identified as byproducts of known toxicity but all found below levels for concern.

Electrochemical synthesis of transition element complexes with carboxyl- and carbonyl-containing ligands

International Nuclear Information System (INIS)

Frolov, V.Yu.; Bolotin, S.N.; Panyushkin, V.T.

2005-01-01

Complexes of d- and f-elements (E = Cu, Ni, Zn, Nd, Tb, Pr, Gd, Er) with carboxyl- and carbonyl-containing ligands were synthesized by the electrochemical method. The products were characterized by elemental analysis, thermal gravimetric analysis and IR spectra. The influence exerted by a number of factors on the process course was studied. The dependence of the electro synthesis parameters on the composition of the forming compounds was established. A new method for anodic synthesis of these compounds was developed [ru

Observations and Explicit Modeling of Summertime Carbonyl Formation in Beijing: Identification of Key Precursor Species and Their Impact on Atmospheric Oxidation Chemistry

Science.gov (United States)

Yang, Xue; Xue, Likun; Wang, Tao; Wang, Xinfeng; Gao, Jian; Lee, Shuncheng; Blake, Donald R.; Chai, Fahe; Wang, Wenxing

2018-01-01

Carbonyls are an important group of volatile organic compounds (VOCs) that play critical roles in tropospheric chemistry. To better understand the formation mechanisms of carbonyl compounds, extensive measurements of carbonyls and related parameters were conducted in Beijing in summer 2008. Formaldehyde (11.17 ± 5.32 ppbv), acetone (6.98 ± 3.01 ppbv), and acetaldehyde (5.27 ± 2.24 ppbv) were the most abundant carbonyl species. Two dicarbonyls, glyoxal (0.68 ± 0.26 ppbv) and methylglyoxal (MGLY; 1.10 ± 0.44 ppbv), were also present in relatively high concentrations. An observation-based chemical box model was used to simulate the in situ production of formaldehyde, acetaldehyde, glyoxal, and MGLY and quantify their contributions to ozone formation and ROx budget. All four carbonyls showed similar formation mechanisms but exhibited different precursor distributions. Alkenes (mainly isoprene and ethene) were the dominant precursors of formaldehyde, while both alkenes (e.g., propene, i-butene, and cis-2-pentene) and alkanes (mainly i-pentane) were major precursors of acetaldehyde. For dicarbonyls, both isoprene and aromatic VOCs were the dominant parent hydrocarbons of glyoxal and MGLY. Photolysis of oxygenated VOCs was the dominant source of ROx radicals (approximately >80% for HO2 and approximately >70% for RO2) in Beijing. Ozone production occurred under a mixed-control regime with carbonyls being the key VOC species. Overall, this study provides some new insights into the formation mechanisms of carbonyls, especially their parent hydrocarbon species, and underlines the important role of carbonyls in radical chemistry and ozone pollution in Beijing. Reducing the emissions of alkenes and aromatics would be an effective way to mitigate photochemical pollution in Beijing.

Frequency of Gγ-globin promoter -158 (C>T) XmnI polymorphism in patients with homozygous/compound heterozygous beta thalassaemia.

Science.gov (United States)

Ali, Nadir; Ayyub, Muhammad; Khan, Saleem Ahmed; Ahmed, Suhaib; Abbas, Kazim; Malik, Hamid Saeed; Tashfeen, Sunila

2015-03-01

Response to hydroxyurea therapy in homozygous or compound heterozygous beta thalassaemia (BT) has been reported as more favourable in the presence of XmnI polymorphism. The prevalence of XmnI polymorphism may vary with BT phenotypes and genotypes, and differs geographically in distribution. Prevalence of XmnI polymorphism is not known in northern Pakistan. To determine the frequency of Gγ-globin promoter -158 (C>T) XmnI polymorphism (XmnI polymorphism) in patients with homozygous or compound heterozygous beta thalassaemia. Polymerase chain reaction (PCR) for common beta thalassaemia mutations and Gγ-globin promoter -158 (C>T) XmnI polymorphism was performed on 107 blood samples of transfusion dependent beta thalassaemia (BT) patients in Pakistan. One hundred samples of unrelated BT traits and 94 samples of healthy subjects as controls were also analysed for BT mutations and XmnI polymorphism. Out of 301 DNA samples, XmnI polymorphism was detected in 71(24%); in normal controls, XmnI polymorphism was detected in 34/94 (36%) subjects; while in homozygous/compound heterozygous BT, it was detected in 14/107(13%) patients (Fisher's exact test, p=.0002). In heterozygous BT group, XmnI polymorphism was detected in 23/100 subjects (Fisher's exact test, p=.03 with normal controls, and p=.049 with homozygous/compound heterozygous BT). The most common BT genotype was Frame Shift (Fr) 8-9/Fr 8-9, and none of the patients with this genotype had XmnI polymorphism. The second most common genotype was IVSI-5/IVSI-5; 4/26 (15%). Cases with this genotype had XmnI polymorphism. XmnI polymorphism in homozygous/compound heterozygous BT group is 13%. The most common genotype associated with XmnI polymorphism was IVSI-5/IVSI-5. Copyright © 2015 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

NMR spectroscopy of organic compounds of selenium and tellurium. Communication 8. Constants of spin-spin interaction of /sup 125/Te-/sup 1/o/sup 3/C in nmr spectra of unsaturated organtellurides

Energy Technology Data Exchange (ETDEWEB)

Kalabin, G.A.; Kushnarev, D.F.; Valeev, R.B. (Irkutskij Gosudarstvennyj Univ. (USSR))

1981-06-01

On the basis of /sup 13/C NMR spectra of a series of unsaturated and aromatic tellurium compounds the constants of spin-spin interaction (SSIC) (sup(1.2)J(Te, C)) are measured. A reliable linear relation between /sup 1/J(Te, C) and s-character of a carbon orbitale forming bond with tellurium is found. Correlation of straight SSIC of carbon with selenium and tellurium in isological compounds is established.

Computational Elucidation of a Role That Brønsted Acidification of the Lewis Acid-Bound Water Might Play in the Hydrogenation of Carbonyl Compounds with H2 in Lewis Basic Solvents.

Science.gov (United States)

Heshmat, Mojgan; Privalov, Timofei

2017-08-25

Brønsted acidification of water by Lewis acid (LA) complexation is one of the fundamental principles in chemistry. Using transition-state calculations (TS), herein we investigate the role that Brønsted acidification of the LA-bound water might play in the mechanism of the hydrogenation of carbonyl compounds in Lewis basic solvents under non-anhydrous conditions. The potential energy scans and TS calculations were carried out with a series of eight borane LAs as well as the commonly known strong LA AlCl 3 in 1,4-dioxane or THF as Lewis basic solvents. Our molecular model consists of the dative LA-water adduct with hydrogen bonds to acetone and a solvent molecule plus one additional solvent molecule that participates is the TS structure describing the cleavage of H 2 at acetone's carbonyl carbon atom. In all the molecular models applied here, acetone (O=CMe 2 ) is the archetypical carbonyl substrate. We demonstrate that Brønsted acidification of the LA-bound water can indeed lower the barrier height of the solvent-involving H 2 -cleavage at the acetone's carbonyl carbon atom. This is significant because at present it is believed that the mechanism of the herein considered reaction is described by the same mechanism regardless of whether the reaction conditions are strictly anhydrous or non-anhydrous. Our results offer an alternative to this belief that warrants consideration and further study. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microbial carbonylation and hydroxylation of 20(R)-panaxadiol by Aspergillus niger.

Science.gov (United States)

Yan, Bin; Chen, Zhihua; Zhai, Xuguang; Yin, Guibo; Ai, Yafei; Chen, Guangtong

2018-04-01

20(R)-panaxadiol (PD) was metabolised by the fungus Aspergillus niger AS 3.3926 to its C-3 carbonylated metabolite and five other hydroxylated metabolites (1-6). Their structures were elucidated as 3-oxo-20(R)-panaxadiol (1), 3-oxo-7β-hydroxyl- 20(R)-panaxadiol (2), 3-oxo-7β,23α-dihydroxyl-20(R)-panaxadiol (3), 3,12-dioxo- 7β,23β-dihydroxyl-20(R)-panaxadiol (4), 3-oxo-1α,7β-dihydroxyl-20(R)-panaxadiol (5) and 3-oxo-7β,15β-dihydroxyl-20(R)-panaxadiol (6) by spectroscopic analysis. Among them, compounds 2-6 were new compounds. Pharmacological studies revealed that compound 6 exhibited significant anti-hepatic fibrosis activity.

Highly Functionalised Cyclopentanes by Radical Cyclisation of Unsaturated Bromolactones III. Preparation of Carbaaldohexofuranoses. - Determination of the Relative Configuration at C-4/C-5 of 2,3-Unsaturated heptono-1,4-lactones by Means of 1-H NMR Spectroscopy

DEFF Research Database (Denmark)

Lundt, Inge; Horneman, Anne Marie

1999-01-01

Two new carbaaldohexofuranoses, carba--D-glucofuranose and carba--L-mannofuranose have been prepared using 5,6-O-isopropylidene-D-glycero-L-galacto-heptono-1,4-lactone (6) as the starting material. The key step was a highly stereoselective intramolecular 5-exo-trig radical cyclisation of C-2......-substituted 2,3-unsaturated 7-bromo-7-deoxy-heptono-1,4-lactones promoted by tributyltin hydride. Assignment of the configuration of the unsaturated lactones was based upon NMR data of related compounds. The starting material, compound 6, was obtained by chain elongation of D-gulose, and a facile method...

Design and Synthesis of 11C-Labelled Compound Libraries for the Molecular Imaging of EGFr, VEGFr-2, AT1 and AT2 Receptors: Transition-Metal Mediated Carbonylations Using [11C]Carbon Monoxide

International Nuclear Information System (INIS)

Aaberg, Ola

2009-01-01

This work deals with radiochemistry and new approaches to develop novel PET tracers labelled with the radionuclide 11 C. Two methods for the synthesis of 11 C-labelled acrylamides have been explored. First, [1- 11 C]-acrylic acid was obtained from a palladium(0)-mediated 11 C-carboxylation of acetylene with [ 11 C]carbon monoxide; this could be converted to the corresponding acyl chloride and then combined with benzylamine to form N-benzyl[carbonyl- 11 C]acrylamide. In the second method, the palladium(0)-mediated carbonylation of vinyl halides with [ 11 C]carbon monoxide was explored. This latter method, yielded labelled acrylamides in a single step with retention of configuration at the C=C double bond, and required less amine compared to the acetylene method. The vinyl halide method was used to synthesize a library of 11 C-labelled EGFr-inhibitors in 7-61% decay corrected radiochemical yield via a combinatorial approach. The compounds were designed to target either the active or the inactive form of EGFr, following computational docking studies. The rhodium(I)-mediated carbonylative cross-coupling of an azide and an amine was shown to be a very general reaction and was used to synthesize a library of dual VEGFr-2/PDGFrβ inhibitors that were 11 C-labelled at the urea position in 38-78% dc rcy. The angiotensin II AT 1 receptor antagonist eprosartan was 11 C-labelled at one of the carboxyl groups in one step using a palladium(0)-mediated carboxylation. Autoradiography shows specific binding in rat kidney, lung and adrenal cortex, and organ distribution shows a high accumulation in the intestines, kidneys and liver. Specific binding in frozen sections of human adrenal incidentalomas warrants further investigations of this tracer. Three angiotensin II AT 2 ligands were 11 C-labelled at the amide group in a palladium(0)-mediated aminocarbonylation in 16-36% dc rcy. One of the compounds was evaluated using in vitro using autoradiography, and in vivo using organ

Structure-activity relationships of N-beta-phenylpropionyl-L-tyrosine and its derivatives on the inhibition of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac).

Science.gov (United States)

Ariyoshi, Y.; Takeuchi, H.

1982-01-01

1 Inhibitory effects of N-beta-phenylpropionyl-L-tyrosine, N-beta-phenylpropionyl-L-tryptophan and their derivatives on an identifiable giant neurone, TAN (tonically autoactive neurone) of an African giant snail (Achatina fulica Férussac) were examined in an attempt to elucidate which structural features are necessary to produce the effect. 2 Of the compounds examined, N-beta-cyclohexylpropionyl-L-tyrosine showed the strongest effect. Its critical concentration (c.c.) was 3 X 10(-8)-10(-7)M, about ten times lower than that of N-beta-phenylpropionyl-L-tyrosine (c.c., 3 X 10(-7)-10(-6)M). N-beta-cyclohexylpropionyl-L-tryptophan (c.c., 10(-6)M) had an effect almost similar to that of N-beta-phenylpropionyl-L-tryptophan (c.c., 10(-6)M). 3 N-beta-Phenylpropionyl-N-methyl-L-tyrosine had no effect at a high concentration. 4 Effects of N-beta-phenylpropionyl-L-tyrosine amide (c.c., 3 X 10(-7)-10(-6)M) and N-beta-phenylpropionyl-L-tryptophan amide (c.c., 10(-6)M) were very similar to those of N-beta-phenylpropionyl-L-tyrosine and N-beta-phenylpropionyl-L-tryptophan respectively. 5 N-beta-Phenylpropionyl-p-amino-L-phenylalanine (c.c., 3 X 10(-5)-10(-4)M) and N-beta-phenylpropionyl-p-chloro-L-phenylalanine (c.c., 10(-4)M) had only a weak effect. 6 It is proposed that the structural features producing the effect are as follows: the active compound has a phenyl or a cyclohexyl group (hydrophobic binding group), after a suitable distance a peptide bond (proton donor and proton acceptor), adjacently a carbonyl group (proton acceptor), and a phenolic hydroxyl or an indolyl imino group (proton donor) in the molecule. PMID:7150871

THE METAL CARBONYLS.

Science.gov (United States)

Blanchard, A A

1941-10-03

When the metal carbonyls were first discovered, their properties were startling because they seemed to violate nearly all the previously recognized generalizations of chemistry. Even to-day the existence of the carbonyls is not particularly emphasized in elementary courses of chemistry because it is rather hard to reconcile them with the first presentations of the generalizations of chemistry. Nevertheless, as the student progresses deeper into the knowledge of chemistry it becomes desirable to include the knowledge of the carbonyls both because they become more comprehensible when viewed in the light of Werner's system of coordination and because they themselves contribute to the comprehension of the Werner theory. As long ago as 1931, Reiff in his discussion of cobalt nitrosyl carbonyl recognized the correlation between the effective atomic number and the volatility of carbonyls. A more recent study of charged Werner coordination complexes, that is, of complex ions, has shown a similar role of the effective atomic number. We are standing on fairly firm ground when we point out the correlation between E.A.N. and the volatility of the carbonyl complexes and the existence of complex ions. Be it noted that we have made no postulates as to the arrangement of the electrons in quantum levels. In the inert gases the outer principal quantum group is supposed always to contain eight electrons. In the carbonyls and other Werner complexes there is no compelling reason to suppose that the electrons in the coordinating layer, be this layer of eight, ten, twelve or sixteen electrons, are not all at the same energy level. Although we have confined our discussion almost exclusively to the property of volatility, the carbonyls are very interesting from the standpoint of several other properties, for example, magnetic susceptibility and dielectric constant. Enthusiasts in the interpretation of such properties try to draw conclusions as to the condition of the electrons, sometimes

Seasonal behavior of carbonyls and source characterization of formaldehyde (HCHO) in ambient air

Science.gov (United States)

Lui, K. H.; Ho, Steven Sai Hang; Louie, Peter K. K.; Chan, C. S.; Lee, S. C.; Hu, Di; Chan, P. W.; Lee, Jeffrey Chi Wai; Ho, K. F.

2017-03-01

Gas-phase formaldehyde (HCHO) is an intermediate and a sensitive indicator for volatile organic compounds (VOCs) oxidation, which drives tropospheric ozone production. Effective photochemical pollution control strategies demand a thorough understanding of photochemical oxidation precursors, making differentiation between sources of primary and secondary generated HCHO inevitable. Spatial and seasonal variations of airborne carbonyls based on two years of measurements (2012-2013), coupled with a correlation-based HCHO source apportionment analysis, were determined for three sampling locations in Hong Kong (denoted HT, TC, and YL). Formaldehyde and acetaldehyde were the two most abundant compounds of the total quantified carbonyls. Pearson's correlation analysis (r > 0.7) implies that formaldehyde and acetaldehyde possibly share similar sources. The total carbonyl concentration trends (HT rural). A regression analysis further quantifies the relative primary HCHO source contributions at HT (∼13%), TC (∼21%), and YL (∼40%), showing more direct vehicular emissions in urban than rural areas. Relative secondary source contributions at YL (∼36%) and TC (∼31%) resemble each other, implying similar urban source contributions. Relative background source contributions at TC could be due to a closed structure microenvironment that favors the trapping of HCHO. Comparable seasonal differences are observed at all stations. The results of this study will aid in the development of a new regional ozone (O3) control policy, as ambient HCHO can enhance O3 production and also be produced from atmospheric VOCs oxidation (secondary HCHO).

Protein Carbonylation and Adipocyte Mitochondrial Function*

Science.gov (United States)

Curtis, Jessica M.; Hahn, Wendy S.; Stone, Matthew D.; Inda, Jacob J.; Droullard, David J.; Kuzmicic, Jovan P.; Donoghue, Margaret A.; Long, Eric K.; Armien, Anibal G.; Lavandero, Sergio; Arriaga, Edgar; Griffin, Timothy J.; Bernlohr, David A.

2012-01-01

Carbonylation is the covalent, non-reversible modification of the side chains of cysteine, histidine, and lysine residues by lipid peroxidation end products such as 4-hydroxy- and 4-oxononenal. In adipose tissue the effects of such modifications are associated with increased oxidative stress and metabolic dysregulation centered on mitochondrial energy metabolism. To address the role of protein carbonylation in the pathogenesis of mitochondrial dysfunction, quantitative proteomics was employed to identify specific targets of carbonylation in GSTA4-silenced or overexpressing 3T3-L1 adipocytes. GSTA4-silenced adipocytes displayed elevated carbonylation of several key mitochondrial proteins including the phosphate carrier protein, NADH dehydrogenase 1α subcomplexes 2 and 3, translocase of inner mitochondrial membrane 50, and valyl-tRNA synthetase. Elevated protein carbonylation is accompanied by diminished complex I activity, impaired respiration, increased superoxide production, and a reduction in membrane potential without changes in mitochondrial number, area, or density. Silencing of the phosphate carrier or NADH dehydrogenase 1α subcomplexes 2 or 3 in 3T3-L1 cells results in decreased basal and maximal respiration. These results suggest that protein carbonylation plays a major instigating role in cytokine-dependent mitochondrial dysfunction and may be linked to the development of insulin resistance in the adipocyte. PMID:22822087

Protein carbonylation and adipocyte mitochondrial function.

Science.gov (United States)

Curtis, Jessica M; Hahn, Wendy S; Stone, Matthew D; Inda, Jacob J; Droullard, David J; Kuzmicic, Jovan P; Donoghue, Margaret A; Long, Eric K; Armien, Anibal G; Lavandero, Sergio; Arriaga, Edgar; Griffin, Timothy J; Bernlohr, David A

2012-09-21

Carbonylation is the covalent, non-reversible modification of the side chains of cysteine, histidine, and lysine residues by lipid peroxidation end products such as 4-hydroxy- and 4-oxononenal. In adipose tissue the effects of such modifications are associated with increased oxidative stress and metabolic dysregulation centered on mitochondrial energy metabolism. To address the role of protein carbonylation in the pathogenesis of mitochondrial dysfunction, quantitative proteomics was employed to identify specific targets of carbonylation in GSTA4-silenced or overexpressing 3T3-L1 adipocytes. GSTA4-silenced adipocytes displayed elevated carbonylation of several key mitochondrial proteins including the phosphate carrier protein, NADH dehydrogenase 1α subcomplexes 2 and 3, translocase of inner mitochondrial membrane 50, and valyl-tRNA synthetase. Elevated protein carbonylation is accompanied by diminished complex I activity, impaired respiration, increased superoxide production, and a reduction in membrane potential without changes in mitochondrial number, area, or density. Silencing of the phosphate carrier or NADH dehydrogenase 1α subcomplexes 2 or 3 in 3T3-L1 cells results in decreased basal and maximal respiration. These results suggest that protein carbonylation plays a major instigating role in cytokine-dependent mitochondrial dysfunction and may be linked to the development of insulin resistance in the adipocyte.

Super agonist actions of clothianidin and related compounds on the SAD beta 2 nicotinic acetylcholine receptor expressed in Xenopus laevis oocytes.

Science.gov (United States)

Ihara, Makoto; Matsuda, Kazuhiko; Shimomura, Masaru; Sattelle, David B; Komai, Koichiro

2004-03-01

To compare the actions of clothianidin, a neonicotinoid acting on insect nicotinic acetylcholine receptors, and related compounds with that of imidacloprid, the compounds were tested on the Drosophila SAD-chicken beta2 nicotinic acetylcholine receptor expressed in Xenopus laevis oocytes using two-electrode voltage-clamp electrophysiology. The maximum response of the SAD beta 2 nicotinic receptor to clothianidin was larger than that observed for acetylcholine. Ring breakage of the imidazolidine ring of imidacloprid resulting in the generation of a guanidine group was critical for this super agonist action.

Radical carbonylations using a continuous microflow system

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Takahide Fukuyama

2009-07-01

Full Text Available Radical-based carbonylation reactions of alkyl halides were conducted in a microflow reactor under pressurized carbon monoxide gas. Good to excellent yields of carbonylated products were obtained via radical formylation, carbonylative cyclization and three-component coupling reactions, using tributyltin hydride or TTMSS as a radical mediator.

Kinetics and Mechanism of the Gas-Phase Reaction of Selected Carbonyls with Cl Atoms between 250 and 340 K

Science.gov (United States)

Hasson, A. S.; Algrim, L.; Abdelhamid, A.; Tyndall, G. S.; Orlando, J. J.

2013-12-01

Carbonyls are important products from the gas phase degradation of most volatile organic compounds. Their atmospheric reactions therefore have a significant impact on atmospheric composition, particularly in aged air masses. While the reactions of short-chain linear carbonyls are well understood, the chemistry of larger (> C6) and branched carbonyl is more uncertain. To provide insight into these reactions, the reactions of three carbonyls (methyl isopropyl ketone, MIK; di-isopropyl ketone, DIK; and diethyl ketone, DEK) with chlorine atoms were investigated between 250 and 340 K and 1 atm in the presence and absence of NOx and an HO2 source (methanol). Experiments were performed in a photochemical reactor using a combination of long-path Fourier transform infra-red spectroscopy, proton transfer reaction mass spectrometry and gas chromatography with flame ionization detection. The kinetics were studied using the relative rate technique with butanone and isopropanol as the reference compounds. The Arrhenius expression for the three rate coefficients was determined to be k(DEK+Cl) = 3.87 x 10-11e(2 × 7 kJ/mol)/RT cm3 molecules-1 s-1 , k(MIPK+Cl) = 7.20 x 10-11e(0.2× 8 kJ/mol)/RT cm3 molecules-1 s-1 , and k(DIPK+Cl) = 3.33 x 10-10e(-3× 8 kJ/mol)/RT cm3 molecules-1 s-1 . Measured reaction products accounted for 38-72 % of the reacted carbon and were consistent with strong deactivation of the carbon atom adjacent to the carbonyl group with respect to H-atom abstraction by Cl atoms. The product distributions also provide insight into radical recycling from the organic peroxy + HO2 reaction, and the relative rates of isomerization, fragmentation and reaction with O2 for carbonyl-containing alkoxy radicals. Implications of these results will be discussed.

Bonding in inorganic compounds: a study by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Avanzino, S.C.

1978-10-01

Core electron binding energies were measured for a variety of inorganic and organometallic compounds using gas-phase X-ray photoelectron spectroscopy (XPS). The atomic charge distributions in these molecules are deduced from the binding energies, often leading to a better understanding of the bonding in these compounds. The XPS spectra of fifteen volatile tin compounds were recorded. The data suggest that the metal d orbitals are not significantly involved in the bonding. The oxygen ls XPS spectra of gaseous CH 3 Mn(CO) 5 , [π-C 5 H 5 Fe(CO) 2 ] 2 , and Co 4 (CO) 12 can be readily resolved into separate peaks due to bridging and terminal carbonyl groups. The C ls spectrum of Fe(CO) 5 consists of a single symmetric peak. The carbonyl ligand core binding energies of transition-metal carbonyl complexes are sensitive to differences in the metal-to-CO ligand bonding. Both C ls and O ls carbonyl binding energies correlate well with average C-O stretching force constants or average C-O stretching frequencies. The metal and carbonyl binding energies in a series of pentacarbonylmanganese complexes LMn(CO) 5 are a good measure of the relative electronegativities of the ligands L. High-quality X-ray photoelectron spectra have been obtained for compounds dissolved in glycerin solutions, and aqueous solutions were converted into glycerin solutions which gave good XRSspectra of the solutes. The technique appears promising as a future analytical application of X-ray photoelectron spectroscopy. The shifts in the binding energies of oxygen, chlorine, and carbon atoms in some isoelectronic isostructural compounds can be explained in terms of simple trends in atomic charges

Leachate movement through unsaturated sand at a low-level radioactive-waste disposal site in northwestern Illinois

International Nuclear Information System (INIS)

Mills, P.C.; Devries, M.P.

1988-01-01

Movement of radionuclides and volatile organic compounds in soil water (leachate) were examined in an unsaturated sand deposit immediately underlying trenches at a low-level radioactive-waste disposal site near Sheffield, Illinois. Physical and hydraulic properties of the 2.0- to 8.0-meter thick sand deposit were defined from core samples. Soil-water samples were collected from 16 gravity lysimeters and 1 vacuum lysimeter from September 1986 through October 1987. Preliminary results include the following: Tritium, halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons, nonhalogenated aromatic hydrocarbons, and methyl esters were detected in the soil water. Gross alpha and gross beta concentrations were detected at background levels. Tritium flux through the gravity lysimeters ranged from 0.18 to 1.74 microcuries per year and totaled 5.14 microcuries per year. In most locations, soil-water movement occurred as slow, steady, unsaturated flow; more rapid saturated flow occurred along isolated, narrow (less than 1 square millimeter), vertical flow paths. The homogeneous texture and hydraulic properties of the sand deposit imply that the location of flow paths primarily is dependent on the locations of water entry into, and flow paths within, the void-rich trenches. The timing of water movement through the saturated pathways in the sand deposit was influenced, in part, by individual precipitation events and seasonal climatic trends. Changes in tritium concentration were attributable to changes in soil-water flux and to apparent deterioration of waste containers within the trenches

A Device-Independent Evaluation of Carbonyl Emissions from Heated Electronic Cigarette Solvents.

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Ping Wang

Full Text Available To investigate how the two main electronic (e- cigarette solvents-propylene glycol (PG and glycerol (GL-modulate the formation of toxic volatile carbonyl compounds under precisely controlled temperatures in the absence of nicotine and flavor additives.PG, GL, PG:GL = 1:1 (wt/wt mixture, and two commercial e-cigarette liquids were vaporized in a stainless steel, tubular reactor in flowing air ranging up to 318°C to simulate e-cigarette vaping. Aerosols were collected and analyzed to quantify the amount of volatile carbonyls produced with each of the five e-liquids.Significant amounts of formaldehyde and acetaldehyde were detected at reactor temperatures ≥215°C for both PG and GL. Acrolein was observed only in e-liquids containing GL when reactor temperatures exceeded 270°C. At 318°C, 2.03±0.80 μg of formaldehyde, 2.35±0.87 μg of acetaldehyde, and a trace amount of acetone were generated per milligram of PG; at the same temperature, 21.1±3.80 μg of formaldehyde, 2.40±0.99 μg of acetaldehyde, and 0.80±0.50 μg of acrolein were detected per milligram of GL.We developed a device-independent test method to investigate carbonyl emissions from different e-cigarette liquids under precisely controlled temperatures. PG and GL were identified to be the main sources of toxic carbonyl compounds from e-cigarette use. GL produced much more formaldehyde than PG. Besides formaldehyde and acetaldehyde, measurable amounts of acrolein were also detected at ≥270°C but only when GL was present in the e-liquid. At 215°C, the estimated daily exposure to formaldehyde from e-cigarettes, exceeded United States Environmental Protection Agency (USEPA and California Office of Environmental Health Hazard Assessment (OEHHA acceptable limits, which emphasized the need to further examine the potential cancer and non-cancer health risks associated with e-cigarette use.

Evaluation of the concentrations and distribution of carbonyl compounds in selected areas of a Brazilian bus terminal.

Science.gov (United States)

de Mendonça Ochs, Soraya; de Almeida Furtado, Leonardo; Pereira Netto, Annibal Duarte

2015-06-01

This study describes the determination of 30 carbonyl compounds (CCs) in three areas (bus boarding platform, passenger circulation area, and a pastry shop) of the Presidente João Goulart Bus Terminal, located at Niterói City, RJ, Brazil, and in an open area 700 m distant from the terminal. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, during May to July 2012. The hydrazones formed were analyzed using rapid resolution liquid chromatography with UV detection. The studied locations showed distinct profiles of distribution of CC. The circulation area, which is influenced by different pollution sources, presented an intermediate profile between that of the pastry shop and boarding platform. Formaldehyde and acetaldehyde were the most abundant CC, but acetaldehyde predominated in the pastry shop once it is a by-product of baking yeast fermentation. Samples taken in the pastry shop and circulation area showed significant concentrations of hexanaldehyde and nonanaldehyde emitted during cooking. The pastry shop showed the largest level of total CC among the studied areas followed by the circulation area, the boarding platform, and the open area.

Catalytic hydrogenation of carbonyl group for deuterated compound production

International Nuclear Information System (INIS)

Gluhoi, C. Andreea; Marginean, P.; Lazar, Diana; Almasan, V.

1999-01-01

The total deuterated isopropyl alcohol can be produced starting from acetone. The developed technology comprises two steps: Deuteration of acetone by H/D isotopic exchange between acetone and heavy water in homogeneous catalysis. Reduction of the deuterated acetone with deuterium in presence of a metal/support catalyst. H/D isotopic exchange reaction of the H atoms from CH 3 groups is easy to occur because carbonyl group weakens C-H bond (ceto-enolyc tautomery). The big difference between boiling points of acetone and water permits an easy separation of acetone by distillation method. The reduction of acetone with deuterium was performed in a dynamic reactor by passing a deuterium flow saturated with acetone vapour through a supported nickel catalyst bed. The reaction products were analysed on-line using a flame ionisation detector. The supported nickel catalysts were checked for this reaction. By using nickel over different supports the selectivity for isopropyl alcohol was about 100%. The propane was detected only as traces. The catalytic activity depends strongly on the support nature: the Ni/SiO 2 is less active, while the Ni/TiO 2 presents the larger value for the intrinsic activity. (authors)

[1,3-Bis(diphenyl-phosphino)pentane-κP,P']tetra-carbonyl-chromium(0).

Science.gov (United States)

Shawkataly, Omar Bin; Thangadurai, Daniel T; Pankhi, Mohd Aslam A; Shahinoor Dulal Islam, S M; Fun, Hoong-Kun

2009-02-04

In the title compound, [Cr(C(29)H(30)P(2))(CO)(4)], the Cr atom is octa-hedrally coordinated by four carbonyl ligands and one bidentate phosphine ligand, which is bounded as a chelate in a cis position. The average Cr-P and Cr-C bond lengths are 2.377 and 1.865 Å, respectively.

Ruthenium(ii)-catalyzed olefination via carbonyl reductive cross-coupling† †Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c7sc04207h

Science.gov (United States)

Wei, Wei; Dai, Xi-Jie; Wang, Haining; Li, Chenchen; Yang, Xiaobo

2017-01-01

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KOtBu and bidentate phosphine dmpe is vital to this transformation. PMID:29568466

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

Energy Technology Data Exchange (ETDEWEB)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk [Kyung Hee Univ., Seoul (Korea, Republic of)

2012-11-15

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O{sub 2} might be the main reason for the activity of the selenium catalyst for this reaction.

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

International Nuclear Information System (INIS)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk

2012-01-01

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O 2 might be the main reason for the activity of the selenium catalyst for this reaction

Comparison of the skin sensitizing potential of unsaturated compounds as assessed by the murine local lymph node assay (LLNA) and the guinea pig maximization test (GPMT).

Science.gov (United States)

Kreiling, R; Hollnagel, H M; Hareng, L; Eigler, D; Lee, M S; Griem, P; Dreessen, B; Kleber, M; Albrecht, A; Garcia, C; Wendel, A

2008-06-01

The skin sensitization potential of eight unsaturated and one saturated lipid (bio)chemicals was tested in both the LLNA and the GPMT to address the hypothesis that chemicals with unsaturated carbon-carbon double bonds may result in a higher number of unspecific (false positive) results in the LLNA compared to the GPMT. Seven substances (oleic acid, linoleic acid, linolenic acid, undecylenic acid, maleic acid, squalene and octinol) gave clear positive results in the LLNA (stimulation index (SI)> or = 3) and thus would require labelling as skin sensitizer. Fumaric acid and succinic acid gave clearly negative results. In the GPMT, besides some sporadic skin reactions, reproducible skin reactions indicating an allergic response were found in a few animals for four test substances. Based on the GPMT results, only undecylenic acid would have to be classified and labelled as a skin sensitizer according to the European Dangerous Substance Directive (67/548/EEC) (results for linoleic acid were inconclusive), while the other seven test substances would not require labelling. Possible mechanisms for unspecific skin cell stimulation and lymph node responses are discussed. In conclusion, the suitability of the LLNA for unsaturated compounds bearing structural similarity to the tested substances should be carefully considered and the GPMT should remain available as an accepted test method for skin sensitization hazard identification.

[Study on two preparation methods for beta-CD inclusion compound of four traditional Chinese medicine volatile oils].

Science.gov (United States)

Li, Hailiang; Cui, Xiaoli; Tong, Yan; Gong, Muxin

2012-04-01

To compare inclusion effects and process conditions of two preparation methods-colloid mill and saturated solution-for beta-CD inclusion compound of four traditional Chinese medicine volatile oils and study the relationship between each process condition and volatile oil physical properties and the regularity of selective inclusion of volatile oil components. Volatile oils from Nardostachyos Radix et Rhizoma, Amomi Fructus, Zingiberis Rhizoma and Angelicaesinensis Radix were prepared using two methods in the orthogonal test. These inclusion compounds by optimized processes were assessed and compared by such methods as TLC, IR and scanning electron microscope. Inclusion oils were extracted by steam distillation, and the components found before and after inclusion were analyzed by GC-MS. Analysis showed that new inclusion compounds, but inclusion compounds prepared by the two processes had differences to some extent. The colloid mill method showed a better inclusion effect than the saturated solution method, indicating that their process conditions had relations with volatile oil physical properties. There were differences in the inclusion selectivity of components between each other. The colloid mill method for inclusion preparation is more suitable for industrial requirements. To prepare volatile oil inclusion compounds with heavy gravity and high refractive index, the colloid mill method needs longer time and more water, while the saturated solution method requires higher temperature and more beta-cyclodextrin. The inclusion complex prepared with the colloid mill method contains extended molecular weight chemical composition, but the kinds of components are reduced.

Oxygenated gasoline release in the unsaturated zone - Part 1: Source zone behavior.

Science.gov (United States)

Freitas, Juliana G; Barker, James F

2011-11-01

Oxygenates present in gasoline, such as ethanol and MTBE, are a concern in subsurface contamination related to accidental spills. While gasoline hydrocarbon compounds have low solubility, MTBE and ethanol are more soluble, ethanol being completely miscible with water. Consequently, their fate in the subsurface is likely to differ from that of gasoline. To evaluate the fate of gasoline containing oxygenates following a release in the unsaturated zone shielded from rainfall/recharge, a controlled field test was performed at Canadian Forces Base Borden, in Ontario. 200L of a mixture composed of gasoline with 10% ethanol and 4.5% MTBE was released in the unsaturated zone, into a trench 20cm deep, about 32cm above the water table. Based on soil cores, most of the ethanol was retained in the source, above the capillary fringe, and remained there for more than 100 days. Ethanol partitioned from the gasoline to the unsaturated pore-water and was retained, despite the thin unsaturated zone at the site (~35cm from the top of the capillary fringe to ground surface). Due to its lower solubility, most of the MTBE remained within the NAPL as it infiltrated deeper into the unsaturated zone and accumulated with the gasoline on top of the depressed capillary fringe. Only minor changes in the distribution of ethanol were noted following oscillations in the water table. Two methods to estimate the capacity of the unsaturated zone to retain ethanol are explored. It is clear that conceptual models for sites impacted by ethanol-fuels must consider the unsaturated zone. Copyright © 2011 Elsevier B.V. All rights reserved.

Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements

Energy Technology Data Exchange (ETDEWEB)

Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science)

1981-06-01

Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds.

Production of metal particles and clusters

Science.gov (United States)

Mcmanus, S. P.

1982-01-01

The feasibility of producing novel metals or metal clusters in a low gravity environment was studied. The production of coordinately unsaturated metal carbonyls by thermolysis or photolysis of stable metal carbonyls has the potential to generate novel catalysts by this technique. Laser irradiation of available metal carbonyls was investigated. It is found that laser induced decomposition of metal carbonyls is feasible for producing a variety of coordinately unsaturated species. Formation of clustered species does occur but is hampered by weak metal-metal bonds.

Homogeneously catalysed hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols

NARCIS (Netherlands)

Stouthamer, B.; Vlugter, J.C.

1965-01-01

The use of copper and cadmium oxides or soaps as catalysts for the hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols has been investigated. It is shown that copper soaps homogeneously activate hydrogen. When copper and cadmium oxides are used as catalysts, they react with the

Glucosinolates and isothiocyanates from broccoliseed extractsuppressproteinglycationand carbonylation

Directory of Open Access Journals (Sweden)

Marina Hirano,

2018-01-01

Full Text Available Background: Glucosinolates from brassica plants are hydrolyzed by internal or salivary myrosinase to produce isothiocyanates. Glucoraphanin, a major glucosinolate in broccoli, is hydrolyzed to sulforaphane (SFN, which exhibits antitumor and detoxification activities. Regarding the influence of broccoli and its constituents on the skin, a few studies have reported anti-inflammatory and antioxidant effects. Recently, advanced glycation end products (AGEs and carbonyl proteins have been reported to accelerate skin aging. Objective: We evaluated the effects of broccoli seed extract (BSE and glucosinolates on protein glycation and carbonylation in vitro. Methods: To evaluate the effects of BSE and its constituents, protein glycation and carbonylation were induced by mixing fructose with bovine serum albumin (BSA and then measuring production of AGEs, fructosamine, and carbonyl proteins (CP. Production of CP after mixing fatty acids with BSA was also assessed. Furthermore, the effect of BSE and its constituents on CP production by human fibroblasts (TIG103 was examined. Results: BSE suppressed the production of AGEs, fructosamine, and CP after mixing fructose and BSA. BSE also suppressed production of CP when oxidized linoleic acid was mixed with BSA. Isothiocyanates, including SFN and iberin, suppressed fructose-based CP production, but SFN had no effect on CP production stimulated by oxidized linoleic acid. In contrast, glucosinolates from BSE did not suppress fructose-based CP production, but suppressed CP production due to oxidized linoleic acid. Among the glucosinolates in BSE, glucoberteroin showed the strongest suppression of CP production. CP production in fibroblasts was also suppressed by glucosinolates, including glucoiberin and glucoberteroin. Conclusions: BSE demonstrated anti-glycation and anti-carbonylation effects on protein reactions with fructose and oxidized fatty acids. Isothiocyanates suppressed protein carbonylation induced by

Rapid model building of beta-sheets in electron-density maps.

Science.gov (United States)

Terwilliger, Thomas C

2010-03-01

A method for rapidly building beta-sheets into electron-density maps is presented. beta-Strands are identified as tubes of high density adjacent to and nearly parallel to other tubes of density. The alignment and direction of each strand are identified from the pattern of high density corresponding to carbonyl and C(beta) atoms along the strand averaged over all repeats present in the strand. The beta-strands obtained are then assembled into a single atomic model of the beta-sheet regions. The method was tested on a set of 42 experimental electron-density maps at resolutions ranging from 1.5 to 3.8 A. The beta-sheet regions were nearly completely built in all but two cases, the exceptions being one structure at 2.5 A resolution in which a third of the residues in beta-sheets were built and a structure at 3.8 A in which under 10% were built. The overall average r.m.s.d. of main-chain atoms in the residues built using this method compared with refined models of the structures was 1.5 A.

Investigation of six-membered carbocyclic compounds as a molecular switch block of room temperature phosphorescence in nondeoxygenated {beta}-cyclodextrin solution

Energy Technology Data Exchange (ETDEWEB)

Zhang Hairong; Wei Yansheng; Jin Weijun; Liu Changsong

2003-05-07

An aerated aqueous solution, intense room temperature phosphorescence (RTP) of nitrogen heterocyclic compounds (NHCs) and polyaromatic hydrocarbons (PAHs) can be observed when micro amounts of six-membered carbocyclic compounds (6-MCCs) are introduced in {beta}-cyclodextrin ({beta}-CD) solution. In order to find the predominating factors of the enhanced phosphorescence observed with this novel approach, 22 typical phosphors of NHCs and PAHs were carefully screened and served as model compounds. The role of the inner heavy atom, the substituent group and the host-guest molecules space-matching on the RTP of different phosphors were investigated. The results demonstrated that the enhancement effects of cyclohexane, bromocyclohexane and cyclohexanol for the RTP of NHCs and PAHs have precedence over traditional halide alkanes such as 1,2-dibromoethane (DBE), exhibiting an obvious sequence as following: cyclohexane > bromocyclohexane > cyclohexanol. This new approach compared with other RTP methods is simple, convenient and fast.

Modulation of 17{beta}-estradiol-induced responses in fish by cytochrome P4501A1 inducing compounds

Energy Technology Data Exchange (ETDEWEB)

Anderson, M.J.; Hinton, D.E. [Univ. of California, Davis, CA (United States)

1995-12-31

Some compounds which induce cytochrome P4501A1 (CYP1A1) are antiestrogenic in mammalian bioassay, and this effect is linked to aryl hydrocarbon (Ah) receptor. Liver of fish synthesizes estrogen-inducible egg yolk precursor protein vitellogenin (Vg) which is critical for oocyte maturation and ovarian development. To determine if Ah receptor-linked endocrine modulation could occur in fish liver, primary cultures of juvenile rainbow trout (Oncorhynchus mykiss) liver cells were co-administered 17{beta}-estradiol and CYP1A1 inducing compounds. Vitellogenin and albumin, estimated by ELISA measurement of concentration in the media 48 hrs after treatment, formed the basis for the test. Cellular CYP1A1 protein content and catalytic activity was estimated by ELISA and ethoxyresorufin-O-deethylase (EROD) activity assays respectively. Equivalent viability (mitochondrial dehydrogenase activity) and secretary functional capacity (albumin synthesis) were estimated and correlated with other results. In descending order, 2,3,4,7,8 pentachlorodibenzofuran (10{sup {minus}12} to 10{sup {minus}8} M) > 2,3,7,8 tetrachlorodibenzo-p-dioxin {approx_equal} 2,3,7,8 tetrachlorodibenzofuran (10{sup {minus}11} to 10{sup {minus}8} M) > {beta}-naphthoflavone (10{sup {minus}7} to 10{sup {minus}6} M) inhibited Vg synthesis in 17{beta}-estradiol treated liver cells. Potency of inhibition directly related to strength as an inducer of CYP1A1 protein. At 10-8 M, PCB congeners 77, 126, and 156 did not inhibit Vg synthesis and induced no or only moderate CYP1A1 protein. At 10-8 M, PCB congener 114, a weak CYP1A1 inducer, potentiated Vg synthesis relative to cells treated with 17{beta}-estradiol alone. This study increases their understanding of the consequences of hepatic CYP1A1 induction, forewarns of reproductive impairment of sexually maturing fishes exposed to CYP1A1 inducing compounds and argues for further, more detailed in vivo investigation.

Structural analyses of polymorphic transitions of sn-1, 3-distearoyl-2-oleoylglycerol (SOS) and sn-1, 3-dioleoyl-2-stearoylglycerol (OSO): assessment on steric hindrance of unsaturated and saturated acyl chain interactions.

Science.gov (United States)

Yano, J; Sato, K; Kaneko, F; Small, D M; Kodali, D R

1999-01-01

Polymorphic transformations in two saturated-unsaturated mixed acid triacylglycerols, SOS (sn -1,3-distearoyl-2-oleoylglycerol) and OSO (sn -1,3-dioleoyl-2-stearoylglycerol), have been studied by FT-IR spectroscopy using deuterated specimens in which stearoyl chains are fully deuterated. A reversible phase transition between sub alpha and alpha and a series of irreversible transitions (alpha-->gamma-->beta'-->beta (beta2, beta1) for SOS and alpha-->beta'-->beta for OSO) were studied with an emphasis on the conformational ordering process of stearoyl and oleoyl chains. The alpha-->sub alpha reversible transition was due to the orientational change of stearoyl chains in the lateral directions from the hexagonal subcell to a perpendicularly packed one. As the first stage of the series of irreversible transitions from alpha to beta, the conformational ordering of saturated chains took place in the alpha-->gamma transition of SOS and in the alpha-->beta' transition of OSO; one stearoyl chain in SOS and OSO takes the all-trans conformation and the second stearoyl chain in SOS takes the bent conformation like those observed in the most stable beta-type. As the final stage, the ordering of unsaturated chains occurred in the beta'-->beta transition both for SOS and OSO. A conversion in the layered structure from bilayer to trilayer was also accompanied by the conformational ordering in the alpha-->gamma transition of SOS and in the beta'-->beta transition of OSO.

Nicotine and Carbonyl Emissions From Popular Electronic Cigarette Products: Correlation to Liquid Composition and Design Characteristics.

Science.gov (United States)

El-Hellani, Ahmad; Salman, Rola; El-Hage, Rachel; Talih, Soha; Malek, Nathalie; Baalbaki, Rima; Karaoghlanian, Nareg; Nakkash, Rima; Shihadeh, Alan; Saliba, Najat A

2018-01-05

Available in hundreds of device designs and thousands of flavors, electronic cigarette (ECIG) may have differing toxicant emission characteristics. This study assesses nicotine and carbonyl yields in the most popular brands in the U.S. market. These products included disposable, prefilled cartridge, and tank-based ECIGs. Twenty-seven ECIG products of 10 brands were procured and their power outputs were measured. The e-liquids were characterized for pH, nicotine concentration, propylene glycol/vegetable glycerin (PG/VG) ratio, and water content. Aerosols were generated using a puffing machine and nicotine and carbonyls were, respectively, quantified using gas chromatograph and high-performance liquid chromatography. A multiregression model was used to interpret the data. Nicotine yields varied from 0.27 to 2.91 mg/15 puffs, a range corresponding to the nicotine yield of less than 1 to more than 3 combustible cigarettes. Nicotine yield was highly correlated with ECIG type and brand, liquid nicotine concentration, and PG/VG ratio, and to a lower significance with electrical power, but not with pH and water content. Carbonyls, including the carcinogen formaldehyde, were detected in all ECIG aerosols, with total carbonyl concentrations ranging from 3.72 to 48.85 µg/15 puffs. Unlike nicotine, carbonyl concentrations were mainly correlated with power. In 15 puffs, some ECIG devices emit nicotine quantities that exceed those of tobacco cigarettes. Nicotine emissions vary widely across products but carbonyl emissions showed little variations. In spite of that ECIG users are exposed to toxicologically significant levels of carbonyl compounds, especially formaldehyde. Regression analysis showed the importance of design and e-liquid characteristics as determinants of nicotine and carbonyl emissions. Periodic surveying of characteristics of ECIG products available in the marketplace is valuable for understanding population-wide changes in ECIG use patterns over time. © The

Validation of protein carbonyl measurement: A multi-centre study

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Edyta Augustyniak

2015-04-01

Full Text Available Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15 min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5 min of UV irradiation irrespective of method used. After irradiation for 15 min, less oxidation was detected by half of the laboratories than after 5 min irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical for carbonyl analysis and heavily oxidised proteins may not be effectively analysed by any existing technique.

Alternative synthetic route for the heterometallic CO-releasing [Sb@Rh12(CO27]3− icosahedral carbonyl cluster and synthesis of its new unsaturated [Sb@Rh12(CO24]4− and dimeric [{Sb@Rh12Sb(CO25}2Rh(CO2PPh3]7− derivatives

Directory of Open Access Journals (Sweden)

Cristina Femoni

2016-10-01

Full Text Available The hetero-metallic [Sb@Rh12(CO27]3− cluster has been known as for over three decades thanks to Vidal and co-workers, and represents the first example of an E-centered (E=heteroatom icosahedral rhodium carbonyl cluster. However, its synthesis required high temperature (140–160 °C and elevated CO pressure (400 atm. Applying the redox condensation method for cluster preparation, we herein report a new synthetic, high-yield route for preparing [Sb@Rh12(CO27]3− under much milder conditions of temperature and pressure. Notably, when the same synthesis was carried out under N2 instead of CO atmosphere, the new isostructural but unsaturated derivative [Sb@Rh12(CO24]4− was obtained, for which we report the full X-ray structural characterization. This species represents one of the few examples of an icosahedral cluster disobeying the electron-counting Wade-Mingos rules, possessing less than the expected 170 cluster valence electrons (CVEs. Judging from IR monitoring, the two species can be obtained one from the other by switching between N2 and CO atmosphere, making [Sb@Rh12(CO27]3− a spontaneous CO-releasing molecule. Finally, the study of the chemical reactivity of [Sb@Rh12(CO27]3− with PPh3 allowed us to obtain the new [{Sb@Rh12Sb(CO25}2Rh(CO2PPh3]7− dimeric compound, for which we herein report the full X-ray structural and 31P NMR analyses.

Performance audits and laboratory comparisons for SCOS97-NARSTO measurements of speciated volatile organic compounds

Science.gov (United States)

Fujita, Eric M.; Harshfield, Gregory; Sheetz, Laurence

Performance audits and laboratory comparisons were conducted as part of the quality assurance program for the 1997 Southern California Ozone Study (SCOS97-NARSTO) to document potential measurement biases among laboratories measuring speciated nonmethane hydrocarbons (NMHC), carbonyl compounds, halogenated compounds, and biogenic hydrocarbons. The results show that measurements of volatile organic compounds (VOC) made during SCOS97-NARSTO are generally consistent with specified data quality objectives. The hydrocarbon comparison involved nine laboratories and consisted of two sets of collocated ambient samples. The coefficients of variation among laboratories for the sum of the 55 PAM target compounds and total NMHC ranged from ±5 to 15 percent for ambient samples from Los Angeles and Azusa. Abundant hydrocarbons are consistently identified by all laboratories, but discrepancies occur for olefins greater than C 4 and for hydrocarbons greater than C 8. Laboratory comparisons for halogenated compounds and biogenic hydrocarbons consisted of both concurrent ambient sampling by different laboratories and round-robin analysis of ambient samples. The coefficients of variation among participating laboratories were about 10-20 percent. Performance audits were conducted for measurement of carbonyl compounds involving sampling from a standard mixture of carbonyl compounds. The values reported by most of the laboratories were within 10-20 percent of those of the reference laboratory. Results of field measurement comparisons showed larger variations among the laboratories ranging from 20 to 40 percent for C 1-C 3 carbonyl compounds. The greater variations observed in the field measurement comparison may reflect potential sampling artifacts, which the performance audits did not address.

Composition tunable cobalt–nickel and cobalt–iron alloy nanoparticles below 10 nm synthesized using acetonated cobalt carbonyl

International Nuclear Information System (INIS)

Schooneveld, Matti M. van; Campos-Cuerva, Carlos; Pet, Jeroen; Meeldijk, Johannes D.; Rijssel, Jos van; Meijerink, Andries; Erné, Ben H.; Groot, Frank M. F. de

2012-01-01

A general organometallic route has been developed to synthesize Co x Ni 1−x and Co x Fe 1−x alloy nanoparticles with a fully tunable composition and a size of 4–10 nm with high yield. In contrast to previously reported synthesis methods using dicobalt octacarbonyl (Co 2 (CO) 8 ), here the cobalt–cobalt bond in the carbonyl complex is first broken with anhydrous acetone. The acetonated compound, in the presence of iron carbonyl or nickel acetylacetonate, is necessary to obtain small composition tunable alloys. This new route and insights will provide guidelines for the wet-chemical synthesis of yet unmade bimetallic alloy nanoparticles.

Optimized biotin-hydrazide enrichment and mass spectrometry analysis of peptide carbonyls

DEFF Research Database (Denmark)

Havelund, Jesper F.; Wojdyla, K; Jensen, O. N.

Irreversible cell damage through protein carbonylation is the result of reaction with reactive oxygen species (ROS) and has been coupled to many diseases. The precise molecular consequences of protein carbonylation, however, are still not clear. The localization of the carbonylated amino acid is ...... modifications are isobaric to carbonylation and it is often challenging to detect the weaker signal from carbonylated peptides necessitating enrichment step. We here present an optimized method for the enrichment of carbonylated peptides....

Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity

OpenAIRE

Lucarini, Simone; Fagioli, Laura; Campana, Raffaella; Cole, Hannah; Duranti, Andrea; Baffone, Wally; Vllasaliu, Driton; Casettari, Luca

2016-01-01

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, mono-esterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeab...

Vapor phase carbonylation of dimethyl ether and methyl acetate with supported transition metal catalysts

International Nuclear Information System (INIS)

Shikada, T.; Fujimoto, K.; Tominaga, H.O.

1986-01-01

The synthesis of acetic acid (AcOH) from methanol (MeOH) and carbon monoxide has been performed industrially in the liquid phase using a rhodium complex catalyst and an iodide promoter. The selectivity to AcOH is more than 99% under mild conditions (175 0 C, 28 atm). The homogeneous rhodium catalyst has been also effective for the synthesis of acetic anhydride (Ac 2 O) by carbonylation of dimethyl ether (DME) or methyl acetate (AcOMe). However, rhodium is one of the most expensive metals and its proved reserves are quite limited. It is highly desired, therefore, to develop a new catalyst as a substitute for rhodium. The authors have already reported that nickel supported on active carbon exhibits an excellent activity for the vapor phase carbonylation of MeOh in the presence of iodide promoter and under moderately pressurized conditions. In addition, corrosive attack on reactors by iodide compounds is expected to be negligible in the vapor phase system. In the present work, vapor phase carbonylation of DME and AcOMe on nickel-active carbon (Ni/A.C.) and molybdenum-active carbon (Mo/A.C.) catalysts was studied

Processing of Unsaturated Organic Acid Aerosols by Ozone

Science.gov (United States)

Aloisio, S.; Donaldson, D. J.; Eliason, T. L.; Cziczo, D.; Vaida, V.

2002-05-01

We present results of in-situ studies of the oxidative "processing" of organic aerosols composed of unsaturated organic compounds. Aerosol samples of 2-octenoic acid and undecylenic acid were exposed to approx. 10 mbar ozone in a room temperature, atmospheric pressure flow tube reactor. In-situ spectroscopic probing of the reaction mixture, as well as GC-MS analysis of the flow tube effluent, shows evidence of efficient oxidation of double bonds in the organic species, with production of gas-phase and aerosol phase ozonolysis products.

Kinetic study of the degradation of C5 and C6 unsaturated aldehydes and alcohols by ozone

Science.gov (United States)

Kalalian, Carmen; Roth, Estelle; Chakir, Abdelkhaleq

2017-04-01

Emissions of biogenic volatile organic compounds (VOCs) are higher than those from anthropogenic sources. They are therefore likely to have a great influence on atmospheric chemistry both locally and regionally, through their impact on the HOx balance (HOx = HO + HO2), ozone production and ability to form secondary organic aerosols (SOA). Among the volatile organic compounds of biogenic origin are the family of C5 and C6 unsaturated aldehydes and alcohols. Few information exist regarding the fate of these compounds in the atmosphere especially there reaction with ozone. In this work, we studied the kinetics of the reaction of three unsaturated aldehydes (trans-2-pentenal, trans-2-hexenal and 2-methyl-2-pentenal) and three unsaturated alcohols (1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol) with ozone O3 in a rigid atmospheric simulation chamber coupled to an FTIR spectrometer at four different temperatures (273, 298, 333 and 353 K) and at atmospheric pressure. The rate constants of the ozonolysis reaction of the unsaturated aldehydes and the unsaturated alcohols studied were determined and the following Arrhenius expression was obtained (cm3 molecule -1 s -1): k (Trans -2-pentenal)= (3.83 ± 3.71) x 10-16 exp (- (1706 ± 295) / T) k (Trans-2-hexenal)= (1.43 ± 0.67) x 10-16 exp (- (1369 ± 141) / T) k(2-Methyl-2-pentenal)= (3.62± 0.22) x 10-18 exp (- (121 ± 20) / T) k(1-penten-3-ol) = (1.42 ± 1.24) x 10-16 exp (- (642 ± 250) / T) k(Cis-2-penten-1-ol)= (3.14 ± 0.45) x 10-15 exp (- (1045 ± 40) / T) k(Trans-3-hexen-1-ol)= (6.38 ± 1.75) x 10-16 exp (- (686 ± 89) / T) The obtained data will be discussed in terms of structure-reactivity relationship and compared with the reported reactivity with OH radicals. The atmospheric implications derived from this study are discussed as well.

Carbonyl complexes of rhodium with N-donor ligands: factors determining the formation of terminal versus bridging carbonyls

NARCIS (Netherlands)

Dzik, W.I.; Creusen, C.; de Gelder, R.; Peters, T.P.J.; Smits, J.M.M.; de Bruin, B.

2010-01-01

Cationic rhodium carbonyl complexes supported by a series of different N-3- and N-4-donor ligands were prepared, and their ability to form carbonyl-bridged species was evaluated. Complex [Rh(K3-bpa)(cod)r (1(+)) (bpa = bis(2-picolyBamine, cod = cis,cis-1,5-cyclooctadiene) reacts with I bar of CO to

The Emergence of Manganese-Based Carbonyl Hydrosilylation Catalysts.

Science.gov (United States)

Trovitch, Ryan J

2017-11-21

In recent years, interest in homogeneous manganese catalyst development has intensified because of the earth-abundant and nontoxic nature of this metal. Although compounds of Mn have largely been utilized for epoxidation reactions, recent efforts have revealed that Mn catalysts can mediate a broad range of reductive transformations. Low-valent Mn compounds have proven to be particularly effective for the hydrosilylation of carbonyl- and carboxylate-containing substrates, and this Account aims to highlight my research group's contributions to this field. In our initial 2014 communication, we reported that the bis(imino)pyridine-supported compound ( Ph2PPr PDI)Mn mediates ketone hydrosilylation with exceptional activity under solvent-free conditions. Silanes including Ph 2 SiH 2 , (EtO) 3 SiH, (EtO) 2 MeSiH, and (EtO)Me 2 SiH were found to partially reduce cyclohexanone in the presence of ( Ph2PPr PDI)Mn, while turnover frequencies of up to 1280 min -1 were observed using PhSiH 3 . This led us to evaluate the hydrosilylation of 11 additional ketones and allowed for the atom-efficient preparation of tertiary and quaternary silanes. At that time, it was also discovered that ( Ph2PPr PDI)Mn catalyzes the dihydrosilylation of esters (by way of acyl C-O bond hydrosilylation) to yield a mixture of silyl ethers with modest activity. Earlier this year, the scope of these transformations was extended to aldehydes and formates, and the observed hydrosilylation activities are among the highest obtained for any transition-metal catalyst. The effectiveness of three related catalysts has also been evaluated: ( Ph2PPr PDI)MnH, ( PyEt PDEA)Mn, and [( Ph2PEt PDI)Mn] 2 . To our surprise, ( Ph2PPr PDI)MnH was found to exhibit higher carboxylate dihydrosilylation activity than ( Ph2PPr PDI)Mn, while ( PyEt PDEA)Mn demonstrated remarkable carbonyl hydrosilylation activity considering that it lacks a redox-active supporting ligand. The evaluation of [( Ph2PEt PDI)Mn] 2 revealed

Effect of gamma radiation on the content {beta}-carotene and volatile compounds of cantaloupe melon

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs{sub 137} source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in {beta}-carotene. Both total content of carotenoids and specific {beta}-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and {alpha} -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 k

Inserção de catalisador híbrido na síntese de beta-tiocetonas

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Mariana Pompilio Darbem

2012-06-01

Full Text Available The Michael reaction (or Michael addition involves the addition of a nucleophile, called Michael donor, to an electrophile (α,β-unsaturated, called Michael acceptor. Literature reports several types of nucleophiles applied in this reaction. Among them we can mention compounds containing a sulfur atom. When these nucleophiles are applied to this reaction, it is called as thia-Michael reaction. In this study thiophenol, p- chlorothiophenol and p-methoxythiophenol were tested as Michael donors, and several ketones and aldehydes as Michael acceptors, in order to obtain the formation of sigma bonds carbon-sulfur. Compounds that have in their structure the C-S bond are extremely important, because they can present, for example, antibiotic action, antimicrobial analgesic, and anti-HIV. This research proposes, besides the obtainment of  many beta-thioketonic compounds, the insertion of a new catalyst in thia-Michael reactions, the bis-L-zinc prolinate. This catalyst provided the obtainment of high yield compounds. The reactions were executed using ultrasound, which caused a significant decrease in the reaction time and an increase in the results obtained when compared with data obtained previously in literature. An important fact in this study is that the catalyst used is not soluble in the reaction media and it can be reused without abrupt loss of yield.

Iodine-catalyzed addition of 2-mercaptoethanol to chalcone derivatives: Synthesis of the novel β-mercapto carbonyl compounds

Directory of Open Access Journals (Sweden)

Gürkan Yerli

2012-01-01

Full Text Available In this study, a series of novel β-mercapto carbonyl derivatives (3-(2-hydroxyethylthio-1,3-diarylpropan-1-one (5a-i were prepared by addition of 2-mercaptoethanol (4 to chalcones (3a-i in the presence of catalytic amount of iodine (10 mol % in CH 2Cl 2.

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

International Nuclear Information System (INIS)

Yi Mingguang; Wang Caiyun

1986-01-01

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

Frustrated Lewis pairs-assisted reduction of carbonyl compounds

Czech Academy of Sciences Publication Activity Database

Marek, Aleš; Pedersen, M. H. F.

2015-01-01

Roč. 71, č. 6 (2015), s. 917-921 ISSN 0040-4020 Institutional support: RVO:61388963 Keywords : frustrated Lewis pairs * hydrogen activation * benzyl alcohol * tritium labeling * labeled compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.645, year: 2015

Unsaturated Fatty Acids Supplementation Reduces Blood Lead Level in Rats

Science.gov (United States)

Skoczyńska, Anna; Wojakowska, Anna; Nowacki, Dorian; Bobak, Łukasz; Turczyn, Barbara; Smyk, Beata; Szuba, Andrzej; Trziszka, Tadeusz

2015-01-01

Some dietary factors could inhibit lead toxicity. The aim of this study was to evaluate the effect of dietary compounds rich in unsaturated fatty acids (FA) on blood lead level, lipid metabolism, and vascular reactivity in rats. Serum metallothionein and organs' lead level were evaluated with the aim of assessing the possible mechanism of unsaturated FA impact on blood lead level. For three months, male Wistar rats that were receiving drinking water with (100 ppm Pb) or without lead acetate were supplemented per os daily with virgin olive oil or linseed oil (0.2 mL/kg b.w.) or egg derived lecithin fraction: “super lecithin” (50 g/kg b.w.). Mesenteric artery was stimulated ex vivo by norepinephrine (NE) administered at six different doses. Lecithin supplementation slightly reduced pressor responses of artery to NE. Lead administered to rats attenuated the beneficial effect of unsaturated FA on lipid metabolism and vascular reactivity to adrenergic stimulation. On the other hand, the super lecithin and linseed oil that were characterized by low omega-6 to omega-3 ratio (about 1) reduced the blood lead concentration. This effect was observed in lead poisoned rats (p < 0.0001) and also in rats nonpoisoned with lead (p < 0.05). PMID:26075218

Characterization of hydrocarbons, halocarbons and carbonyls in the atmosphere of Hong Kong.

Science.gov (United States)

Guo, H; Lee, S C; Louie, P K K; Ho, K F

2004-12-01

Ambient air quality measurements of 156 species including 39 alkanes, 32 alkenes, 2 alkynes, 24 aromatic hydrocarbons, 43 halocarbons and 16 carbonyls, were carried out for 120 air samples collected at two sampling stations (CW and TW) in 2001 throughout Hong Kong. Spatial variations of volatile organic compounds (VOCs) in the atmosphere were investigated. Levels of most alkanes and alkenes at TW site were higher than that at the CW site, while the BTEX concentrations at the two sites were close. The BTEX ratios at CW and TW were 1.6:10.1:1.0:1.6 and 2.1:10.8:1.0:2.0, respectively. For major halogenated hydrocarbons, the mean concentrations of chloromethane, CFCs 12 and 22 did not show spatial variations at the two sites. However, site-specific differences were observed for trichloroethene and tetrachloroethene. Furthermore, there were no significant differences for carbonyls such as formaldehyde, acetaldehyde and acetone between the two sites. The levels of selected hydrocarbons in winter were 1-5 times that in summer. There were no common seasonal trends for carbonyls in Hong Kong. The ambient level of formaldehyde, the most abundant carbonyl, was higher in summer. However, levels of acetaldehyde, acetone and benzaldehyde in winter were 1.6-3.8 times that in summer. The levels of CFCs 11 and 12, and chloromethane in summer were higher than that in winter. Strong correlation of most hydrocarbons with propene and n-butane suggested that the primary contributors of hydrocarbons were vehicular emissions in Hong Kong. In addition, gasoline evaporation, use of solvents, leakage of liquefied petroleum gas (LPG), natural gas leakage and other industrial emissions, and even biogenic emissions affected the ambient levels of hydrocarbons. The sources of halocarbons were mainly materials used in industrial processes and as solvents. Correlation analysis suggested that photochemical reactions made significant contributions to the ambient levels of carbonyls in summer whereas

A carnosine intervention study in overweight human volunteers: bioavailability and reactive carbonyl species sequestering effect

Science.gov (United States)

Regazzoni, Luca; de Courten, Barbora; Garzon, Davide; Altomare, Alessandra; Marinello, Cristina; Jakubova, Michaela; Vallova, Silvia; Krumpolec, Patrik; Carini, Marina; Ukropec, Jozef; Ukropcova, Barbara; Aldini, Giancarlo

2016-06-01

Carnosine is a natural dipeptide able to react with reactive carbonyl species, which have been recently associated with the onset and progression of several human diseases. Herein, we report an intervention study in overweight individuals. Carnosine (2 g/day) was orally administered for twelve weeks in order to evaluate its bioavailability and metabolic fate. Two carnosine adducts were detected in the urine samples of all subjects. Such adducts are generated from a reaction with acrolein, which is one of the most toxic and reactive compounds among reactive carbonyl species. However, neither carnosine nor adducts have been detected in plasma. Urinary excretion of adducts and carnosine showed a positive correlation although a high variability of individual response to carnosine supplementation was observed. Interestingly, treated subjects showed a significant decrease in the percentage of excreted adducts in reduced form, accompanied by a significant increase of the urinary excretion of both carnosine and carnosine-acrolein adducts. Altogether, data suggest that acrolein is entrapped in vivo by carnosine although the response to its supplementation is possibly influenced by individual diversities in terms of carnosine dietary intake, metabolism and basal production of reactive carbonyl species.

FTIR study of hydrogen bonding interaction between fluorinated alcohol and unsaturated esters

Science.gov (United States)

Sheng, Xia; Jiang, Xiaotong; Zhao, Hailiang; Wan, Dongjin; Liu, Yongde; Ngwenya, Cleopatra Ashley; Du, Lin

2018-06-01

The 1:1 complexes of two unsaturated esters with 2,2,2-trifluoroethanol (TFE) were investigated experimentally and computationally. The experimental observations of the spectral shifts of the OH-stretching vibrational transitions were obtained at 113 cm-1 for TFE-methyl acrylate (MA) and 92 cm-1 for TFE-vinyl acetate (VA). There are three docking sites in the two unsaturated esters for the incoming TFE. The predicted red shifts of the OH-stretching vibrational transitions were found to be larger for the Osbnd H⋯Odbnd C hydrogen bonded conformer than those for the Osbnd H⋯π and Osbnd H⋯O ones. The binding energies further prove that the Osbnd H⋯Odbnd C hydrogen bonded conformers are the most stable ones. On the basis of the DFT calculations as well as previous works, the carbonyl group is the best docking site for TFE. Furthermore, the thermodynamic equilibrium constants of TFE-MA and TFE-VA were obtained at 0.28 and 0.15 by combining the experimental spectra data and the DFT calculations. Consequently, the Gibbs free energies of formation were determined to be 3.2 and 4.8 kJ mol-1 for TFE-MA and TFE-VA, respectively. The quantum theory of atoms in molecules (AIM) and generalized Kohn-Sham energy decomposition analysis (GKS-EDA) were carried out for further characterization of the hydrogen bonding interactions. GKS-EDA shows an "electrostatic" dominated hydrogen bonding character for the Osbnd H⋯Odbnd C hydrogen bonds.

Cobalt-mediated [3 + 2]-annulation reaction of alkenes with alpha,beta-unsaturated ketones and imines.

Science.gov (United States)

Schomaker, Jennifer M; Toste, F Dean; Bergman, Robert G

2009-08-20

The utility of cobalt dinitrosyl complexes for the [3 + 2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)(3)/LHMDS formed two new C-C bonds at the carbons alpha to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bicyclic olefins.

Determination of Chemical Compounds Generated from Second-generation E-cigarettes Using a Sorbent Cartridge Followed by a Two-step Elution Method.

Science.gov (United States)

Uchiyama, Shigehisa; Senoo, Yui; Hayashida, Hideki; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

2016-01-01

We developed an analytical method for analyzing electronic cigarette (E-cigarette) smoke, and measured the carbonyl compounds and volatile organic compounds generated by 10 brands of second-generation E-cigarettes. A glass filter (Cambridge filter pad) for particulate matter and a solid sorbent tube packed with Carboxen-572 for gaseous compounds were used to collect E-cigarette smoke. These were then analyzed using a two-step elution method with carbon disulfide and methanol, followed by high-performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC/MS). Formaldehyde (FA), acetaldehyde (AA), acetone (AC), acrolein (ACR), propanal (PA), acetol (AT), glyoxal (GO), and methyl glyoxal (MGO) were detected by HPLC in some E-cigarettes. Propylene glycol (PG), glycerol (GLY), and some esters were detected by GC/MS. GO and MGO exist mainly as particulate matter. AA, AC, ACR, PA, and AT exist mainly as gaseous compounds. FA exists as both particulate matter and gaseous compounds. These carbonyl compounds have carbon numbers C1 - C3. The main components of E-liquid are PG (C3) and GLY (C3). Therefore, the oxidation of liquids, such as PG and GLY in E-cigarettes upon incidental contact with the heating element in E-cigarette, is suggested as being a possible cause for carbonyl generation. When the puff number exceeds a critical point, carbonyl generation rapidly increases and then remains constant. The results of this study are now being used to determine the following E-cigarette smoking protocol: puff volume, 55 mL; puff duration, 2 s; and puff number, 30. E-cigarette analysis revealed very large variation in carbonyl concentration among not only different brands, but also different samples of the same product. Typical distributions of carbonyl concentration were not observed in any of the E-cigarettes tested, and the mean values greatly differed from median values.

A brief review on synthesis & applications of β-enamino carbonyl compounds

Directory of Open Access Journals (Sweden)

yellajyosula L N Murthy

2012-01-01

Full Text Available Owing to the wide range applications of β-enamino esters (enamines of β–dicarbonyl compounds in pharmaceuticals and as building blocks for the synthesis of a variety of heterocyclic compounds, β-amino esters, β-amino acids, γ-amino alcohols, peptides and alkaloids a number of methods have been developed so far for the synthesis of these compounds. Due to the importance of these compounds as intermediates in organic synthesis, a concised review is presented.

Pattern of occurrence and occupancy of carbonylation sites in proteins

DEFF Research Database (Denmark)

Rao, R Shyama Prasad; Møller, Ian Max

2011-01-01

sites. Comparison of metal-catalyzed oxidation of two closely related proteins indicates that this type of carbonylation might not be very specific in proteins. Interestingly, carbonylated sites show a very strong tendency to cluster together in the protein primary sequence hinting at some sort......Proteins are targets for modification by reactive oxygen species, and carbonylation is an important irreversible modification that increases during oxidative stress. While information on protein carbonylation is accumulating, its pattern is not yet understood. We have made a meta...

Influence of gamma radiation reaction on the hydroesterification of butenes catalyzed by metal carbonyls

International Nuclear Information System (INIS)

Velde, J. van der.

1976-01-01

In the hydro carboxylation reaction, which first has been studied by Reppe, olefine and acetylene compounds are processed with carbon monoxide and water at high pressures and high temperatures in the presence of metal carbonyls. This reaction can be enhanced considerably by application of ionizing radiation. Lower pressures and in particular lower temperatures can be used if gamma irradiation is performed during carboxylation. For the experiments a mixture of buten-1 and buten-2 as well as pure buten-1 and pure buten-2 has been used to study the behaviour of these olefines with respect to the isomerization of the reaction products and to the olefines not transformed in the reaction process. Replacing water, methanol has been used as a reaction component, thus obtaining directly the respective carbonyl acid esters, which can be analysed quantitatively and qualitatively with respect to their isomeric composition by gaschromatography. (orig./HK) [de

Mass Spectrometric Approaches to the Identification of Potential Ingredients in Cigarette Smoke Causing Cytotoxicity.

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Horiyama, Shizuyo; Kunitomo, Masaru; Yoshikawa, Noriko; Nakamura, Kazuki

2016-01-01

Cigarette smoke contains many harmful chemicals that contribute to the pathogenesis of smoking-related diseases such as chronic obstructive pulmonary disease, cancer, and cardiovascular disease. Many studies have been done to identify cytotoxic chemicals in cigarette smoke and elucidate the onset of the above-mentioned diseases caused by smoking. However, definitive mechanisms for cigarette smoke toxicity remain unknown. As candidates for cytotoxic chemicals, we have recently found methyl vinyl ketone (MVK) and acetic anhydride in nicotine/tar-free cigarette smoke extract (CSE) using L-tyrosine (Tyr), an amino acid with highly reactive hydroxyl group. The presence of MVK and acetic anhydride in CSE was confirmed by gas chromatography-mass spectrometry (GC/MS). We also found new reaction products formed in B16-BL6 mouse melanoma (B16-BL6) cells treated with CSE using LC/MS. These were identified as glutathione (GSH) conjugates of α,β-unsaturated carbonyl compounds, MVK, crotonaldehyde (CA), and acrolein (ACR), by the mass value and product ion spectra of these new products. ACR and MVK are type-2 alkenes, which are well known as electron acceptors and form Michael-type adducts to nucleophilic side chain of amino acids on peptides. These α,β-unsaturated carbonyl compounds may have a key role in CSE-induced cell death.

Determination of gaseous and particulate carbonyls (glycolaldehyde, hydroxyacetone, glyoxal, methylglyoxal, nonanal and decanal in the atmosphere at Mt. Tai

Directory of Open Access Journals (Sweden)

K. Kawamura

2013-05-01

Full Text Available Gaseous and particulate semi-volatile carbonyl compounds were determined every three hours in the atmosphere of Mount Tai (elevation, 1534 m in the North China Plain during 2–5, 23–24 and 25 June 2006 under clear sky conditions. Using a two-step filter cartridge in a series, particulate carbonyls were first collected on a quartz filter and then gaseous carbonyls were collected on a quartz filter impregnated with O-benzylhydroxylamine (BHA. After the two-step derivatization with BHA and N,O-Bis(trimethylsilyltrifluoroacetamide (BSTFA, carbonyl derivatives were measured using a gas chromatography. The gaseous concentrations were obtained as follow: glycolaldehyde (range 0–826 ng m−3, average 303 ng m−3, hydroxyacetone (0–579 ng m−3, 126 ng m−3, glyoxal (46–1200 ng m−3, 487 ng m−3, methylglyoxal (88–2690 ng m−3, 967 ng m−3, n-nonanal (0–500 ng m−3, 89 ng m−3, and n-decanal (0–230 ng m−3, 39 ng m−3. These concentrations are among the highest ever reported in the urban and forest atmosphere. We found that gaseous α-dicarbonyls (glyoxal and methylglyoxal are more than 20 times more abundant than particulate carbonyls and that glycolaldehyde is one order of magnitude more abundant than in aerosol phase. In contrast, hydroxyacetone and normal aldehydes (nonanal and decanal are equally present in both phases. Time-resolved variations of carbonyls did not show any a clear diurnal pattern, except for hydroxyacetone. We found that glyoxal, methylglyoxal and glycolaldehyde positively correlated with levoglucosan (a tracer of biomass burning, suggesting that a contribution from field burning of agricultural wastes (wheat crops is significant for the bifunctional carbonyls in the atmosphere of Mt. Tai. Upward transport of the pollutants to the mountaintop from the low lands in the North China Plain is a major process to control the distributions of carbonyls in the upper atmosphere over Mt. Tai.

Protein carbonylation sites in bovine raw milk and processed milk products.

Science.gov (United States)

Milkovska-Stamenova, Sanja; Mnatsakanyan, Ruzanna; Hoffmann, Ralf

2017-08-15

During thermal treatment of milk, proteins are oxidized, which may reduce the nutritional value of milk, abolish protein functions supporting human health, especially important for newborns, and yield potentially harmful products. The side chains of several amino acids can be oxidized to reactive carbonyls, which are often used to monitor oxidative stress in organisms. Here we mapped protein carbonylation sites in raw milk and different brands of pasteurized, ultra high temperature (UHT) treated milk, and infant formulas (IFs) after digesting the precipitated proteins with trypsin. Reactive carbonyls were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine to enrich the modified peptides by avidin-biotin affinity chromatography and analyze them by nanoRP-UPLC-ESI-MS. Overall, 53 unique carbonylated peptides (37 carbonylation sites, 15 proteins) were identified. Most carbonyls were derived from dicarbonyls (mainly glyoxal). The number of carbonylation sites increased with the harsher processing from raw milk (4) to pasteurized (16) and UHT milk (16) and to IF (24). Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of fiber material on ozone removal and carbonyl production from carpets

Science.gov (United States)

Abbass, Omed A.; Sailor, David J.; Gall, Elliott T.

2017-01-01

Indoor air quality is affected by indoor materials such as carpets that may act as sources and/or sinks of gas-phase air pollutants. Heterogeneous reactions of ozone with carpets may result in potentially harmful products. In this study, indoor residential carpets of varying fiber types were tested to evaluate their ability to remove ozone, and to assess their role in the production of carbonyls when exposed to elevated levels of ozone. Tests were conducted with six types of new unused carpets. Two sets of experiments were conducted, the first measured ozone removal and ozone deposition velocities, and the second measured primary carbonyl production and secondary production as a result of exposure to ozone. The tests were conducted using glass chambers with volume of 52 L each. Air exchange rates for all tests were 3 h-1. The ozone removal tests show that, for the conditions tested, the polyester carpet sample had the lowest ozone removal (40%), while wool carpet had the greatest ozone removal (65%). Most carpet samples showed higher secondary than primary carbonyl emissions, with carpets containing polypropylene fibers being a notable exception. Carpets with polyester fibers had both the highest primary and secondary emissions of formaldehyde among all samples tested. While it is difficult to make blanket conclusions about the relative air quality merits of various carpet fiber options, it is clear that ozone removal percentages and emissions of volatile organic compounds can vary drastically as a function of fiber type.

Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

Science.gov (United States)

Lee, M T; Ahmed, T; Friedman, M E

1989-01-01

Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

EFSA ; Scientific Opinion on Flavouring Group Evaluation 98 (FGE.98): Consideration of three ring-unsaturated delta-lactones)

DEFF Research Database (Denmark)

Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present consideration concerns a group of three unsaturated delta-lactones [FL-no: 10.031, 10.037 and 10.044] previously evaluated by the JECFA at their 49th meeting in 1997. The JECFA considered that further information...... on the metabolism of these three substances was required and that they should be evaluated together with other substances containing alpha,beta-unsaturation and that, therefore, their evaluation should be deferred. However, the EFSA Panel has considered that these three JECFA evaluated aliphatic lactones can...... be hydrolysed and metabolised to innocuous products in line with the aliphatic lactones evaluated by EFSA in FGE.10Rev2. The substances were evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern...

Selected carbonyl compounds in the air of Silesia region

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Czaplicka, Marianna; Chrobok, Michał

2018-01-01

This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a three sites in Silesian region (Poland) in January and June 2015. Aldehydes in polluted atmospheres comes from both primary and secondary sources, which limits the control strategies for these reactive compounds. Average aldehyde concentration in summer period lies in range from 3.13 μg/m3 to 10.43 μg/m3, in winter period in range from 29.0 μg/m3 to 32.2 μg/m3. Acetaldehyde was dominant compound in winter period, in summer formaldehyde concentration was highest of all determined aldehydes.

Selected carbonyl compounds in the air of Silesia region

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Czaplicka Marianna

2018-01-01

Full Text Available This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein at a three sites in Silesian region (Poland in January and June 2015. Aldehydes in polluted atmospheres comes from both primary and secondary sources, which limits the control strategies for these reactive compounds. Average aldehyde concentration in summer period lies in range from 3.13 μg/m3 to 10.43 μg/m3, in winter period in range from 29.0 μg/m3 to 32.2 μg/m3. Acetaldehyde was dominant compound in winter period, in summer formaldehyde concentration was highest of all determined aldehydes.

TEN DAY EXPOSURES TO CARBONYL SULFIDE PRODUCE BRAINSTEM LESIONS AND CHANGES IN BRAINSTEM AUDITORY EVOKED RESPONSES IN FISCHER 344N RATS.

Science.gov (United States)

Carbonyl sulfide (COS) is a chemical intermediate in the production of pesticides and herbicides, a metabolite of carbon disulfide, a byproduct of the combustion of organic material, and a naturally occurring compound. COS was included in a Toxic Substances Control Act request fo...

Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

DEFF Research Database (Denmark)

Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

1976-01-01

Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

New methods of arene iodination and functional transformation of multiple bonds in organic compounds

International Nuclear Information System (INIS)

Filimonov, V.D.; Chajkovskij, V.K.; Krasnokutskaya, E.A.

2000-01-01

The review summarizes the latest results of organic chemistry and technology of organic synthesis department of Tomsk polytechnical university concerning iodination of arenes and chemical transformations of unsaturated compounds. Preparative possibilities of the new reactions and reagents for iodination, oxidation of alkenes and alkynes to 1,2- and bis-1,2-dicarbonyl compounds, iodonitration of alkynes, and reaction of oxidative dimerization of the terminal alkynes to unsaturated δ-sultones are discussed [ru

Ozone Effects on Protein Carbonyl Content in the Frontal ...

Science.gov (United States)

Oxidative stress (OS) plays an important role in susceptibility and disease in old age. Understanding age-related susceptibility is a critical part of community-based human health risk assessment of chemical exposures. There is growing concern over a common air pollutant, ozone (03), and adverse health effects including dysfunction of the pulmonary, cardiac, and nervous systems. The objective of this study was to test whether OS plays a role in the adverse effects caused by 03 exposure, and if so, if effects were age-dependent. We selected protein carbonyl as an indicator of OS because carbonyl content of cells is a useful indicator of oxidative protein damage and has been linked to chemical-induced adverse effects. Male Brown Norway rats (4, 12, and 24 months) were exposed to 03 (0,0.25 or 1 ppm) via inhalation for 6 h/day, 2 days per week for 13 weeks. Frontal cortex (FC) and cerebellum (CB) were dissected, quick frozen on dry ice, and stored at -80°C. Protein carbonyls were assayed using commercial kits. Hydrogen peroxide, a positive control, increased protein carbonyls in cortical tissue in vitro in a concentration-dependent manner. Significant effects of age on protein carbonyls in FC and a significant effect of age and 03 dose on protein carbonyls in CB were observed. In control rats, there was an age-dependent increase in protein carbonyls indicating increased OS in 12 and 24 month old rats compared to 4 month old rats. Although 03 increase

Metal-Diazo Radicals of α-Carbonyl Diazomethanes

Science.gov (United States)

Li, Feifei; Xiao, Longqiang; Liu, Lijian

2016-03-01

Metal-diazo radicals of α-carbonyl diazomethanes are new members of the radical family and are precursors to metal-carbene radicals. Herein, using electron paramagnetic resonance spectroscopy with spin-trapping, we detect diazo radicals of α-carbonyl diazomethanes, induced by [RhICl(cod)]2, [CoII(por)] and PdCl2, at room temperature. The unique quintet signal of the Rh-diazo radical was observed in measurements of α-carbonyl diazomethane adducts of [RhICl(cod)]2 in the presence of 5,5-dimethyl-pyrroline-1-N-oxide (DMPO). DFT calculations indicated that 97.2% of spin density is localized on the diazo moiety. Co- and Pd-diazo radicals are EPR silent but were captured by DMPO to form spin adducts of DMPO-N• (triplet-of-sextets signal). The spin-trapping also provides a powerful tool for detection of metal-carbene radicals, as evidenced by the DMPO-trapped carbene radicals (DMPO-C•, sextet signal) and 2-methyl-2-nitrosopropane-carbene adducts (MNP-C•, doublet-of-triplets signal). The transformation of α-carbonyl diazomethanes to metal-carbene radicals was confirmed to be a two-step process via metal-diazo radicals.

Defects in tor regulatory complexes retard aging and carbonyl/oxidative stress development in yeast Sассharomyces cerevisiae

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B. V. Homza

2014-02-01

Full Text Available TOR signaling pathway first described in yeast S. сerevisiae is the highly conserved regulator of eukaryotic cell growth, aging and stress resistance. The effect of nitrogen sources, in particular amino acids, on the activity of TOR signaling pathway is well studied, however its relation to carbohydrates is poor understood. The aim of the present study is expanding of our understanding of potential role of TOR regulatory complexes in development of carbonyl/oxidative stress that can result from yeast cultivation on glucose and fructose. It has been shown that the level of α-dicarbonyl compounds and protein carbonyl groups increased with time of yeast cultivation and was higher in cells grown on fructose that demonstrated their accelerated aging and carbonyl/oxidative stress development as compared with cells grown on glucose. The strains defective in TOR proteins cultivated in the presence of glucose as well as fructose demonstrated lower markers of the stress and aging than parental strain. Thus these data confirmed the previous conclusion on fructose more potent ability to cause carbonyl/oxidative stress and accelerated aging in S. cerevisiae as compared with glucose. However, defects in TOR regulatory complexes retard aging and development of the stress in yeast independent on the type of carbohydrate in the cultivation medium.

[1,3-Bis(diphenyl­phosphino)pentane-κ2 P,P′]tetra­carbonyl­chromium(0)

Science.gov (United States)

Shawkataly, Omar bin; Thangadurai, Daniel T.; Pankhi, Mohd. Aslam A.; Shahinoor Dulal Islam, S. M.; Fun, Hoong-Kun

2009-01-01

In the title compound, [Cr(C29H30P2)(CO)4], the Cr atom is octa­hedrally coordinated by four carbonyl ligands and one bidentate phosphine ligand, which is bounded as a chelate in a cis position. The average Cr—P and Cr—C bond lengths are 2.377 and 1.865 Å, respectively. PMID:21582044

Ruthenium and osmium carbonyl nitrosyl complexes: Matrix infrared spectra and density functional calculations for M(CO){sub 2}(NO){sub 2} and M(CO)(NO) (M = Ru, Os)

Energy Technology Data Exchange (ETDEWEB)

Song, Zhenjun [Department of Chemistry, Tongji University, Shanghai 200092 (China); Wang, Xuefeng, E-mail: xfwang@tongji.edu.cn [Department of Chemistry, Tongji University, Shanghai 200092 (China); Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Laser-ablated ruthenium or osmium atom reactions with CO and NO mixtures in solid argon. Black-Right-Pointing-Pointer Metal carbonyl nitrosyls including M(CO)(NO) and 18-electron configuration M(CO){sub 2}(NO){sub 2} molecules (M = Ru, Os). Black-Right-Pointing-Pointer The observed absorption bands of reaction products are identified by isotopic substitution and DFT calculations. Black-Right-Pointing-Pointer The bonding and reaction mechanism are discussed in detail. -- Abstract: Laser-ablated ruthenium or osmium atom reactions with CO and NO mixtures in solid argon produce unsaturated metal carbonyl nitrosyls including M(CO)(NO) and 18-electron configuration M(CO){sub 2}(NO){sub 2} molecules (M = Ru, Os). The observed absorption bands of reaction products are identified by isotopic substitution, isotopic ratios and isotopic distributions ({sup 13}CO, {sup 15}NO, and mixtures). DFT (B3LYP and BP86) vibrational fundamental calculations reproduce observed frequencies and isotopic shifts very well. The bonding and reaction mechanism are discussed.

NMR spectroscopy of organic compounds of selenium and tellurium. Communication 9. Chemical shifts of /sup 13/C in isological series of unsaturated ethers, sulfides, selenides and tellurides

Energy Technology Data Exchange (ETDEWEB)

Kalabin, G.A.; Bzhezovskii, V.M.; Kushnarev, D.F.; Proidakov, A.G. (Irkutskii Gosudarstvennyj Univ. (USSR))

1981-06-01

The effects of heteroatoms Eh(Eh=O, S, Se, Te) on /sup 13/C chemical shifts in eleven isological series of R/sup 1/-Eh-R/sup 2/ unsaturated compounds are compared. A linear relation between /sup 13/C nuclei screening and tEh electronegativity is observed. An assumption is suggested that both likeness of the effects of 6A and 7A group elements on /sup 13/C chemical shifts of R/sup 1/ and R/sup 2/ substituents and their difference for elements of the 4A group are caused by unbonded interactions of the substituents with unshared electron pairs of heteroatoms.

Preparation and microwave shielding property of silver-coated carbonyl iron powder

International Nuclear Information System (INIS)

Cao, Xiao Guo; Ren, Hao; Zhang, Hai Yan

2015-01-01

Highlights: • The silver-coated carbonyl iron powder is prepared by the electroless plating process. • The silver-coated carbonyl iron powder is a new kind of conductive filler. • The reflection and absorption dominate the shielding mechanism of the prepared powder. • Increasing the thickness of electroconductive adhesive will increase the SE. - Abstract: Electroless silver coating of carbonyl iron powder is demonstrated in the present investigation. The carbonyl iron powders are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD) before and after the coating process. The relatively uniform and continuous silver coating is obtained under the given coating conditions. In this paper, the electromagnetic interference (EMI) shielding mechanism of the silver-coated carbonyl iron powder is suggested. The reflection of silver coating and absorption of carbonyl iron powder dominate the shielding mechanism of the silver-coated carbonyl iron powder. The silver-coated carbonyl iron powders are used as conductive filler in electroconductive adhesive for electromagnetic interference shielding applications. The effect of the thickness of electroconductive adhesive on the shielding effectiveness (SE) is investigated. The results indicate that the SE increases obviously with the increase of the thickness of electroconductive adhesive. The SE of the electroconductive adhesive with 0.35 mm thickness is above 38 dB across the tested frequency range

Dansyl labeling and bidimensional mass spectrometry to investigate protein carbonylation.

Science.gov (United States)

Palmese, Angelo; De Rosa, Chiara; Marino, Gennaro; Amoresano, Angela

2011-01-15

Carbonylation is a non-enzymatic irreversible post-translational modification. The adduction of carbonyl groups to proteins is due to the presence of excess of ROS in cells. Carbonylation of specific amino acid side chains is one of the most abundant consequences of oxidative stress; therefore, the determination of carbonyl groups content in proteins is regarded as a reliable way to estimate the cellular damage caused by oxidative stress. This paper reports a novel RIGhT (Reporter Ion Generating Tag) (A. Amoresano, G. Monti, C. Cirulli, G. Marino. Rapid Commun. Mass Spectrom. 2006, 20, 1400) approach for selective labeling of carbonyl groups in proteins using dansylhydrazide, coupled with selective analysis by bidimensional mass spectrometry. We first applied this approach to ribonuclease A and lysozyme as model proteins. According to the so-called 'gel-free procedures', the analysis is carried out at the level of peptides following tryptic digest of the whole protein mixture. Modified RNaseA was analyzed in combined MS(2) and MS(3) scan mode, to specifically select the dansylated species taking advantage of the dansyl-specific fragmentation pathways. This combination allowed us to obtain a significant increase in signal/noise ratio and a significant increase in sensitivity of analysis, due to the reduction of duty cycle of the mass spectrometer. The unique signal obtained was correlated to peptide 1-10 of RNaseA carbonylated and labeled by dansylhydrazide. This strategy represents the first method leading to the direct identification of the carbonylation sites in proteins, thus indicating the feasibility of this strategy to investigate protein carbonylation in a proteomic approach. Copyright © 2010 John Wiley & Sons, Ltd.

Carbonyl Stress and Microinflammation-Related Molecules as Potential Biomarkers in Schizophrenia

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Tohru Ohnuma

2018-03-01

Full Text Available This literature review primarily aims to summarize our research, comprising both cross-sectional and longitudinal studies, and discuss the possibility of using microinflammation-related biomarkers as peripheral biomarkers in the diagnosis and monitoring of patients with schizophrenia. To date, several studies have been conducted on peripheral biomarkers to recognize the potential markers for the diagnosis of schizophrenia and to determine the state and effects of therapy in patients with schizophrenia. Research has established a correlation between carbonyl stress, an environmental factor, and the pathophysiology of neuropsychiatric diseases, including schizophrenia. In addition, studies on biomarkers related to these stresses have achieved results that are either replicable or exhibit consistent increases or decreases in patients with schizophrenia. For instance, pentosidine, an advanced glycation end product (AGE, is considerably elevated in patients with schizophrenia; however, low levels of vitamin B6 [a detoxifier of reactive carbonyl compounds (RCOs] have also been reported in some patients with schizophrenia. Another study on peripheral markers of carbonyl stress in patients with schizophrenia revealed a correlation of higher levels of glyceraldehyde-derived AGEs with higher neurotoxicity and lower levels of soluble receptors capable of diminishing the effects of AGEs. Furthermore, studies on evoked microinflammation-related biomarkers (e.g., soluble tumor necrosis factor receptor 1 have reported relatively consistent results, suggesting the involvement of microinflammation in the pathophysiology of schizophrenia. We believe that our cross-sectional and longitudinal studies as well as various previous inflammation marker studies that could be interpreted from several perspectives, such as mild localized encephalitis and microvascular disturbance, highlighted the importance of early intervention as prevention and distinguished the possible

Formation of chemical compounds from irradiated mixtures of aromatic hydrocarbons and nitrogen oxides

NARCIS (Netherlands)

Besemer, A.C.

1982-01-01

The paper describes the analysis of products of the photochemical degradation of toluene and toluene-14C in smog chamber experiments. Compounds identified included methylglyoxal, possibly the recently postulated butenedial and other carbonyl compounds. The main product of photochemical degradation

Synthesis and preclinical evaluation of [11C-carbonyl]PF-04457845 for neuroimaging of fatty acid amide hydrolase

International Nuclear Information System (INIS)

Hicks, Justin W.; Parkes, Jun; Sadovski, Oleg; Tong, Junchao; Houle, Sylvain; Vasdev, Neil; Wilson, Alan A.

2013-01-01

Introduction: Fatty acid amide hydrolase (FAAH) has a significant role in regulating endocannabinoid signaling in the central nervous system. As such, FAAH inhibitors are being actively sought for pain, addiction, and other indications. This has led to the recent pursuit of positron emission tomography (PET) radiotracers targeting FAAH. We report herein the preparation and preclinical evaluation of [ 11 C-carbonyl]PF-04457845, an isotopologue of the potent irreversible FAAH inhibitor. Methods: PF-04457845 was radiolabeled at the carbonyl position via automated [ 11 C]CO 2 -fixation. Ex vivo brain biodistribution of [ 11 C-carbonyl]PF-04457845 was carried out in conscious rats. Specificity was determined by pre-administration of PF-04457845 or URB597 prior to [ 11 C-carbonyl]PF-04457845. In a separate experiment, rats injected with the title radiotracer had whole brains excised, homogenized and extracted to examine irreversible binding to brain parenchyma. Results: The title compound was prepared in 5 ± 1% (n = 4) isolated radiochemical yield based on starting [ 11 C]CO 2 (decay uncorrected) within 25 min from end-of-bombardment in > 98% radiochemical purity and a specific activity of 73.5 ± 8.2 GBq/μmol at end-of-synthesis. Uptake of [ 11 C-carbonyl]PF-04457845 into the rat brain was high (range of 1.2–4.4 SUV), heterogeneous, and in accordance with reported FAAH distribution. Saturable binding was demonstrated by a dose-dependent reduction in brain radioactivity uptake following pre-treatment with PF-04457845. Pre-treatment with the prototypical FAAH inhibitor, URB597, reduced the brain radiotracer uptake in all regions by 71–81%, demonstrating specificity for FAAH. The binding of [ 11 C-carbonyl]PF-04457845 to FAAH at 40 min post injection was irreversible as 98% of the radioactivity in the brain could not be extracted. Conclusions: [ 11 C-carbonyl]PF-04457845 was rapidly synthesized via an automated radiosynthesis. Ex vivo biodistribution studies in

Enantioselective radical addition/trapping reactions with alpha,beta-disubstituted unsaturated imides. Synthesis of anti-propionate aldols.

Science.gov (United States)

Sibi, Mukund P; Petrovic, Goran; Zimmerman, Jake

2005-03-02

This manuscript describes a highly diastereo- and enantioselective intermolecular radical addition/hydrogen atom transfer to alpha,beta-disubstituted enoates. Additionally, we show that anti-propionate aldol-like products can be easily prepared from alpha-methyl-beta-acyloxyenoates in good yields and high diastereo- and enantioselectivities.

Electromagnetic properties of carbonyl iron and their microwave ...

Indian Academy of Sciences (India)

Administrator

The aim of this paper is to develop a novel thin micro- wave absorber with good absorbing performance in wide bandwidth and lightweight. So we investigated the micro- wave absorbing characterization of silicone rubber using carbonyl iron as filler. Carbonyl iron can be widely used in the field of electromagnetic shielding ...

Compound list: transforming growth factor beta 1 [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available transforming growth factor beta 1 TGFB1 00182 ftp://ftp.biosciencedbc.jp/archive/op...en-tggates/LATEST/Human/in_vitro/transforming_growth_factor_beta_1.Human.in_vitro.Liver.zip ...

Aerobic Oxidation of Alcohols to Carbonyl Compounds Catalyzed by ...

Indian Academy of Sciences (India)

Hydrotalcite-like compounds; cobalt porphyrin; alcohol oxidation; ... cient catalytic method for the low temperature oxy- ... nitrate,8 acetaldehyde,9 ammonium salts10 and NO2,11 ..... N, Sakurai H and Tsukuda T 2009 Effect of electronic.

The influence of variety on the content of bioactive compounds in beetroot (Beta vulgaris L.

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Ján Kovarovič

2017-01-01

Full Text Available Vegetable are widespread throughout the world and is a major part of the human diet. From the perspective of agricultural crops that belong to the group of Beta vulgaris (beetroot, mangold, sugar beets, fodder beet are first-rate vegetables. Especially popular is used in the food industry for the production of sugar, various vegetable juices, coloring agents, and many other products. Beetroot (Beta vulgaris L. is considered one of the ten most important vegetable in the world, thanks to the content of rare natural pigments (betalains, polyphenols, flavonoids, antioxidants, vitamins, minerals and fiber. In this work we evaluated content of bioactive substances, especially the content of total polyphenols, anthocyanins and antioxidant activity in several varieties (Cylindra, Kahira, Chioggia, Crosby Egyptian of beetroot (Beta vulgaris L.. Samples of plant material were collected at full maturity stages from areas of Zeleneč (Czech Republic. Zeleneč is area without negative influences and emission sources. Samples of fresh beetroot (Beta vulgaris L. were homogenized and were prepared as an extract: 50 g cut beetroot (Beta vulgaris L. extracted by 100 mL 80% ethanol for sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR. The absorbance was measured at 765 nm of wavelength against blank. The content of total anthocyanins was measured at 520 nm wavelength of the blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl at 515.6 nm in the spectrophotometer. In the present experiment it was detected, that total polyphenols content in samples ranges from 218.00 mg.kg-1 to 887.75 mg.kg-1, total anthocyanins content in samples ranges from 14.48 ±0.40 mg.kg-1 to 84.50 ±4.71 mg.kg-1 and values of antioxidant activity were in interval from 8.37 ±0.29% to 21.83 ±0.35%. 

Rh(I) -Catalyzed Intramolecular Carbonylative C-H/C-I Coupling of 2-Iodobiphenyls Using Furfural as a Carbonyl Source.

Science.gov (United States)

Furusawa, Takuma; Morimoto, Tsumoru; Nishiyama, Yasuhiro; Tanimoto, Hiroki; Kakiuchi, Kiyomi

2016-08-19

Synthesis of fluoren-9-ones by a Rh-catalyzed intramolecular C-H/C-I carbonylative coupling of 2-iodobiphenyls using furfural as a carbonyl source is presented. The findings indicate that the rate-determining step is not a C-H bond cleavage but, rather, the oxidative addition of the C-I bond to a Rh(I) center. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The unsaturated bistable stochastic resonance system.

Science.gov (United States)

Zhao, Wenli; Wang, Juan; Wang, Linze

2013-09-01

We investigated the characteristics of the output saturation of the classical continuous bistable system (saturation bistable system) and its impact on stochastic resonance (SR). We further proposed a piecewise bistable SR system (unsaturated bistable system) and developed the expression of signal-to-noise ratio (SNR) using the adiabatic approximation theory. Compared with the saturation bistable system, the SNR is significantly improved in our unsaturated bistable SR system. The numerical simulation showed that the unsaturated bistable system performed better in extracting weak signals from strong background noise than the saturation bistable system.

1,4-Addition of tetraethyl fluoromethylenebisphosphonate to alpha, beta-unsaturated compounds

Czech Academy of Sciences Publication Activity Database

Opekar, Stanislav; Beier, Petr

2011-01-01

Roč. 132, č. 5 (2011), s. 363-366 ISSN 0022-1139 R&D Projects: GA ČR GP203/08/P310 Institutional research plan: CEZ:AV0Z40550506 Keywords : 1,4-addition * phosphonates * fluorine Subject RIV: CC - Organic Chemistry Impact factor: 2.033, year: 2011

Phenolic carbonyls undergo rapid aqueous photodegradation to form low-volatility, light-absorbing products

Science.gov (United States)

Smith, Jeremy D.; Kinney, Haley; Anastasio, Cort

2016-02-01

We investigated the aqueous photochemistry of six phenolic carbonyls - vanillin, acetovanillone, guaiacyl acetone, syringaldehyde, acetosyringone, and coniferyl aldehyde - that are emitted from wood combustion. The phenolic carbonyls absorb significant amounts of solar radiation and decay rapidly via direct photodegradation, with lifetimes (τ) of 13-140 min under Davis, CA winter solstice sunlight at midday (solar zenith angle = 62°). The one exception is guaiacyl acetone, where the carbonyl group is not directly connected to the aromatic ring: This species absorbs very little sunlight and undergoes direct photodegradation very slowly (τ > 103 min). We also found that the triplet excited states (3C*) of the phenolic carbonyls rapidly oxidize syringol (a methoxyphenol without a carbonyl group), on timescales of 1-5 h for solutions containing 5 μM phenolic carbonyl. The direct photodegradation of the phenolic carbonyls, and the oxidation of syringol by 3C*, both efficiently produce low volatility products, with SOA mass yields ranging from 80 to 140%. Contrary to most aliphatic carbonyls, under typical fog conditions we find that the primary sink for the aromatic phenolic carbonyls is direct photodegradation in the aqueous phase. In areas of significant wood combustion, phenolic carbonyls appear to be small but significant sources of aqueous SOA: over the course of a few hours, nearly all of the phenolic carbonyls will be converted to SOA via direct photodegradation, enhancing the POA mass from wood combustion by approximately 3-5%.

Distribution of nonionic organic compounds (highly volatile chlorinated hydrocarbons) in the unsaturated zone

Energy Technology Data Exchange (ETDEWEB)

Grathwohl, P.

1988-01-01

Nonpolar pollutants, e.g. highly volatile chlorinated hydrocarbons (HVCH) are more or less equally distributed among all three soil phases (solids, water, air) in the unsaturated zone. The sorption of HVCH on soil solids depends on the amount and type of organic matter in the soil. For wet material an additional sorption on mineral surfaces can be neglected, since all possible sites for sorption are occupied by water. Provided the partition-coefficients or sorption-constants are known the contamination of the whole system can be evaluated from the pollutant concentration in the soil air; in addition it is possible to estimate a groundwater risk.

Analysis of carbonyl compounds via headspace solid-phase microextraction with on-fiber derivatization and gas chromatographic-ion trap tandem mass spectrometric determination of their O-(2,3,4,5,6-pentafluorobenzyl)oxime derivatives

Energy Technology Data Exchange (ETDEWEB)

Schmarr, Hans-Georg [Dienstleistungszentrum Laendlicher Raum (DLR) Rheinpfalz, Breitenweg 71, D-67435 Neustadt an der Weinstrasse (Germany)], E-mail: hans-georg.schmarr@dlr.rlp.de; Potouridis, Theodoros; Ganss, Sebastian; Sang, Wei; Koepp, Benedikt; Bokuz, Ursula; Fischer, Ulrich [Dienstleistungszentrum Laendlicher Raum (DLR) Rheinpfalz, Breitenweg 71, D-67435 Neustadt an der Weinstrasse (Germany)

2008-06-09

An improved method for the analysis of carbonyls is described utilizing a headspace solid-phase microextraction (HS-SPME) step and on-fiber derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) hydrochloride. Thermal desorption of the oxime derivatives formed on the fiber is followed by gas chromatographic separation coupled to an ion trap tandem mass spectrometer (GC-ITMS). Selecting specific fragment ions within the electron ionization (EI{sup +}) mass spectra of these oxime derivatives as precursor ions for MS-MS fragmentation provides a suitable method for the target analysis of individual carbonyl classes, such as alkanals, (E)-2-alkenals, (E,E)-2,4-alkadienals, and others. Retention indices on polar as well as on apolar stationary phases along with EI{sup +} mass spectra patterns are presented for a large set of oxime derivatives, giving valuable information needed for unambiguous assignment of substances in complex sample matrices. The fast sample preparation and derivatization step via HS-SPME can be automated and is applicable to a variety of biological samples and foodstuffs, allowing rapid and sensitive screening analyses of important aldehydic biomarkers and aroma active compounds.

Optimized formation of detergent micelles of beta-carotene and retinal production using recombinant human beta,beta-carotene 15,15'-monooxygenase.

Science.gov (United States)

Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun

2008-01-01

The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.

Protein carbonylation and metal-catalyzed protein oxidation in a cellular perspective

DEFF Research Database (Denmark)

Møller, Ian Max; Rogowska-Wrzesinska, Adelina; Rao, R S P

2011-01-01

Proteins can become oxidatively modified in many different ways, either by direct oxidation of amino acid side chains and protein backbone or indirectly by conjugation with oxidation products of polyunsaturated fatty acids and carbohydrates. While reversible oxidative modifications are thought...... to be relevant in physiological processes, irreversible oxidative modifications are known to contribute to cellular damage and disease. The most well-studied irreversible protein oxidation is carbonylation. In this work we first examine how protein carbonylation occurs via metal-catalyzed oxidation (MCO) in vivo...... and in vitro with an emphasis on cellular metal ion homeostasis and metal binding. We then review proteomic methods currently used for identifying carbonylated proteins and their sites of modification. Finally, we discuss the identified carbonylated proteins and the pattern of carbonylation sites in relation...

Screening of Chlorinated Paraffins and Unsaturated Analogues in Commercial Mixtures: Confirmation of Their Occurrences in the Atmosphere.

Science.gov (United States)

Li, Tong; Gao, Shixiong; Ben, Yujie; Zhang, Hong; Kang, Qiyue; Wan, Yi

2018-02-20

Characterizing the detailed compositions of chlorinated paraffins (CPs) commercial mixtures is crucial to understand their environmental sources, fates, and potential risks. In this study, dichloromethane (DCM)-enhanced UPLC-ESI-QTOFMS analysis combined with characteristic isotope chlorine peaks is applied to screen all CPs and their structural analogues in the three most commonly produced CP commercial mixtures (CP-42, CP-52, and CP-70). Mass fractions of total short-chain CPs (SCCPs), medium-chain CPs (MCCPs) and long-chain CPs (LCCPs) ranged from 0.64 to 31.9%, 0.64 to 21.8%, and 0.04 to 43.9%, respectively, in the three commercial mixtures. 113 unsaturated SCCPs, MCCPs, and LCCPs were identified in the commercial mixtures. The detailed mass percentages of saturated and unsaturated CPs with carbon numbers of 10-30, chlorine numbers of 5-28, and unsaturated degrees of 0-7 were characterized in all commercial mixtures. Occurrences of the predominant saturated and unsaturated CPs were further confirmed in air samples collected in Guangdong Province, one of the major CP production areas in China, over one year. The profiles of the detected compounds indicated that LCCPs in air samples might come mainly from the production and usage of CP-52, and unsaturated C 24-29 -LCCPs were specifically originated from CP-70 used in the area.

NMR study of the preparation of 6 {alpha}, 7 {beta}-dihydroxyvouacapan-17 beta-oic acid mannich base derivatives

Energy Technology Data Exchange (ETDEWEB)

Santos, Flavio Jose Leite dos; Pilo-Veloso, Dorila [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Inst. de Ciencias Exatas. Dept. Quimica]. E-mail: dorila@zeus.qui.ufmg.br; Ferreira-Alves, Dalton L. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Inst. de Ciencias Biologicas. Dept. de Farmacologia

2007-07-01

This work presents four new Mannich base compounds obtained by the Mannich reaction of a {delta}-keto-lactone derivative of 6{alpha}, 7{beta}-dihydroxyvouacapan- 17{beta}-oic acid, a furano diterpene isolated from the hexane extract of Pterodon polygalaeflorus Benth fruits, which shows anti-inflammatory and analgesic activities. The use of 1D and 2D NMR (COSY, DEPT-135, HMBC, HMQC) spectroscopy made it possible to characterize the new compounds. (author)

Recent Developments in Carbonylation Chemistry Using [13 C]CO, [11 C]CO and [14 C]CO.

Science.gov (United States)

Nielsen, Dennis U; Neumann, Karoline T; Lindhardt, Anders T; Skrydstrup, Troels

2018-06-01

Carbon monoxide represents the most important C1-building block for the chemical industry, both for the production of bulk and fine chemicals, but also for synthetic fuels. Yet, its toxicity and subsequently its cautious handling has limited its applications in medicinal chemistry research and in particular for the synthesis of pharmaceutically relevant molecules. Recent years have nevertheless witnessed a considerable headway on the development of carbon monoxide surrogates and reactor systems, which provide an ideal setting for performing carbonylation chemistry with stoichiometric and sub-stoichiometric carbon monoxide. Such set-ups are particularly ideal for the introduction of isotope labels such as carbon-11, carbon-13 and carbon-14 into bioactive compounds. This review summarizes this growing field and examines the large number of carbonylation reactions that can be exploited for the introduction of a carbon isotope. This article is protected by copyright. All rights reserved.

Kinetics of carbonyl reductase from human brain.

OpenAIRE

Bohren, K M; von Wartburg, J P; Wermuth, B

1987-01-01

Initial-rate analysis of the carbonyl reductase-catalysed reduction of menadione by NADPH gave families of straight lines in double-reciprocal plots consistent with a sequential mechanism being obeyed. The fluorescence of NADPH was increased up to 7-fold with a concomitant shift of the emission maximum towards lower wavelength in the presence of carbonyl reductase, and both NADPH and NADP+ caused quenching of the enzyme fluorescence, indicating formation of a binary enzyme-coenzyme complex. D...

Millimeter wave spectra of carbonyl cyanide ⋆

Science.gov (United States)

Bteich, S.B.; Tercero, B.; Cernicharo, J.; Motiyenko, R.A.; Margulès, L.; Guillemin, J.-C.

2016-01-01

Context More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods The rotational spectrum of carbonyl cyanide was measured in the frequency range 152 - 308 GHz and analyzed using Watson’s A- and S-reduction Hamiltonians. Results The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. PMID:27738349

Unsaturated fatty acids lactose esters: cytotoxicity, permeability enhancement and antimicrobial activity.

Science.gov (United States)

Lucarini, Simone; Fagioli, Laura; Campana, Raffaella; Cole, Hannah; Duranti, Andrea; Baffone, Wally; Vllasaliu, Driton; Casettari, Luca

2016-10-01

Sugar based surfactants conjugated with fatty acid chains are an emerging broad group of highly biocompatible and biodegradable compounds with established and potential future applications in the pharmaceutical, cosmetic and food industries. In this work, we investigated absorption enhancing and antimicrobial properties of disaccharide lactose, monoesterified with unsaturated fatty acids through an enzymatic synthetic approach. After chemical and cytotoxicity characterizations, their permeability enhancing activity was demonstrated using intestinal Caco-2 monolayers through transepithelial electrical resistance (TEER) and permeability studies. The synthesized compounds, namely lactose palmitoleate (URB1076) and lactose nervonate (URB1077), were shown to exhibit antimicrobial activity versus eight pathogenic species belonging to Gram-positive, Gram-negative microorganisms and fungi. Copyright © 2016 Elsevier B.V. All rights reserved.

Unsaturated Mn complex decorated hybrid thioarsenates: Syntheses, crystal structures and physical properties

Energy Technology Data Exchange (ETDEWEB)

Yue, Cheng-Yang [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Lei, Xiao-Wu, E-mail: xwlei_jnu@163.com [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Tian, Ya-Wei; Xu, Jing; Bai, Yi-Qun; Wang, Fei; Zhou, Peng-Fei; Liu, Xiao-Fan [Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong 273155 (China); Yi, Fei-Yan, E-mail: yifeiyan@nbu.edu.cn [Faculty of Materials Science & Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211 (China)

2016-03-15

The incorporation of unsaturated [Mn(1,2-dap)]{sup 2+}, [Mn(1,2-dap){sub 2}]{sup 2+}, [Mn(2,2-bipy)]{sup 2+} (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As{sup III}S{sub 3}]{sup 3−} and [As{sup V}S{sub 4}]{sup 3−} led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} (1), [Mn(1,2-dap){sub 2}]{[Mn(1,2-dap)]_2As_2S_8} (2) and (NH{sub 4})[Mn(2,2-bipy){sub 2}]AsS{sub 4} (3). In compound 1, the unsaturated [Mn(1,2-dap)]{sup 2+} complexes, [MnS{sub 4}]{sup 6−} tetrahedra and [As{sup III}S{sub 3}]{sup 3−} trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)]{sup 2+} and [Mn(1,2-dap){sub 2}]{sup 2+} complexes as well as [As{sup V}S{sub 4}]{sup 3−} tetrahedral units. For compound 3, two [As{sup V}S{sub 4}]{sup 3−} anions bridge two [Mn(2,2-bipy)]{sup 2+} complex cations into a butterfly like {[Mn(2,2-bipy)]_2As_2S_8}{sup 2−} anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3. The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. - Highlights: Three new hybrid manganese thioarsenates have been prepared and structurally characterized. These hybrid phases feature interesting magnetic and visible light responding photocatalytic properties.

Molecular analysis of the beta-thalassemia phenotype associated with inheritance of hemoglobin E (alpha 2 beta2(26)Glu leads to Lys).

OpenAIRE

Benz, E J; Berman, B W; Tonkonow, B L; Coupal, E; Coates, T; Boxer, L A; Altman, A; Adams, J G

1981-01-01

Inheritance of the gene for betaE-globin is associated with hypochromia and microcytosis, reminiscent of typical heterozygous beta-thalassemia. Patients with hemoglobin (Hb)E-beta-thalassemia exhibit clinical phenotypes of severe beta-thalassemia, a circumstance not encountered in other compound heterozygous states for structural beta-chain mutations and beta-thalassemia. We have analyzed the kinetics of globin synthesis and the levels of globin messenger (m) RNA accumulation in patients with...

Formation of chemical compounds from irradiated mixtures of aromatic hydrocarbons and nitrogen oxides

International Nuclear Information System (INIS)

Besemer, A.C.

1982-01-01

The analysis of products of the photochemical degradation of toluene and toluene- 14 C in smog chamber experiments is described. Compounds identified included methylglyoxal, possibly the recently postulated butenedial and other carbonyl compounds. The main product of photochemical degradation of methylglyoxal appeared to be acetaldehyde. (author)

Synthesis, characterization and biological evaluation of novel α, β unsaturated amides.

Science.gov (United States)

Esmailzadeh, K; Housaindokht, M R; Moradi, A; Esmaeili, A A; Sharifi, Z

2016-05-15

Three derivatives of α,β unsaturated amides have been successfully synthesized via Ugi-four component (U-4CR) reaction. The interactions of the amides with calf thymus deoxyribonucleic acid (ct-DNA) have been investigated in the Tris-HCl buffer (pH=7.4) using viscometric, spectroscopic, thermal denaturation studies, and also molecular docking. By UV-Vis absorption spectroscopy studies, adding CT-DNA to the compound solution caused the hypochromism indicates that there are interactions between the compounds and DNA base pairs. In competitive fluorescence with methylene blue as an intercalator probe, adding compounds to DNA-MB solution caused an increase in emission spectra of the complex. This could be because of compound replacing, with similar binding mode of MB, between the DNA base pairs due to release of bonded MB molecules from DNA-MB complex. Thermal denaturation studies and viscometric experiments also indicated that all three investigated compounds bind to CT-DNA by non-classical intercalation mode. Additionally, molecular docking technique predicted partial intercalation binding mode for the compounds. Also, the highest binding energy was obtained for compound 5a. These results are in agreement with results obtained by empirical methods. Copyright © 2016 Elsevier B.V. All rights reserved.

Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

Energy Technology Data Exchange (ETDEWEB)

Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

2009-12-25

Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

Chiral separation of synthetic vicinal diol compounds by capillary zone electrophoresis with borate buffer and beta-cyclodextrin as buffer additive.

Science.gov (United States)

Zhao, Yan; Yang, Xingbin; Jiang, Ru; Sun, Xiaoli; Liu, Wenmin; Zhang, Shengyong

2006-05-01

The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.

Active control of methanol carbonylation selectivity over Au/carbon anode by electrochemical potential.

Science.gov (United States)

Funakawa, Akiyasu; Yamanaka, Ichiro; Otsuka, Kiyoshi

2005-05-12

Electrochemical oxidative carbonylation of methanol was studied over Au supported carbon anode in CO. The major carbonylation products were dimethyl oxalate (DMO) and dimethyl carbonate (DMC). The minor oxidation products were dimethoxy methane (DMM) and methyl formate (MF) from methanol and CO(2). Influences of various reaction conditions were studied on carbonylation activities and selectivities. The selectivities to DMO and DMC can be controlled by the electrochemical potential. Electrocatalysis of Au/carbon anode was studied by cyclic voltammetry (CV), stoichiometric reactions among Au(3+), methanol, and CO, and UV-vis spectra. The Au/carbon anode was characterized by XRD, SEM, and BE images before and after the carbonylation. These experimental facts strongly suggest that transition of oxidation states of Au affects changing of the carbonylation selectivities to DMO and DMC. Au(0) is the active species for the selective DMO formation by direct electrochemical carbonylation at low potentials (selective DMC formation by indirect electrochemical carbonylation through Au(3+)/Au(+) redox at high potentials (>+1.3 V).

Intermetallic nickel silicide nanocatalyst-A non-noble metal-based general hydrogenation catalyst.

Science.gov (United States)

Ryabchuk, Pavel; Agostini, Giovanni; Pohl, Marga-Martina; Lund, Henrik; Agapova, Anastasiya; Junge, Henrik; Junge, Kathrin; Beller, Matthias

2018-06-01

Hydrogenation reactions are essential processes in the chemical industry, giving access to a variety of valuable compounds including fine chemicals, agrochemicals, and pharmachemicals. On an industrial scale, hydrogenations are typically performed with precious metal catalysts or with base metal catalysts, such as Raney nickel, which requires special handling due to its pyrophoric nature. We report a stable and highly active intermetallic nickel silicide catalyst that can be used for hydrogenations of a wide range of unsaturated compounds. The catalyst is prepared via a straightforward procedure using SiO 2 as the silicon atom source. The process involves thermal reduction of Si-O bonds in the presence of Ni nanoparticles at temperatures below 1000°C. The presence of silicon as a secondary component in the nickel metal lattice plays the key role in its properties and is of crucial importance for improved catalytic activity. This novel catalyst allows for efficient reduction of nitroarenes, carbonyls, nitriles, N-containing heterocycles, and unsaturated carbon-carbon bonds. Moreover, the reported catalyst can be used for oxidation reactions in the presence of molecular oxygen and is capable of promoting acceptorless dehydrogenation of unsaturated N-containing heterocycles, opening avenues for H 2 storage in organic compounds. The generality of the nickel silicide catalyst is demonstrated in the hydrogenation of over a hundred of structurally diverse unsaturated compounds. The wide application scope and high catalytic activity of this novel catalyst make it a nice alternative to known general hydrogenation catalysts, such as Raney nickel and noble metal-based catalysts.

Synthesis and Characterization of Tc(I) Carbonyl Nitrosyl Species Relevant to the Hanford Tank Waste: FY 2016 Status Report

Energy Technology Data Exchange (ETDEWEB)

Hall, Gabriel B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chatterjee, Sayandev [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Levitskaia, Tatiana G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Martin, Thibaut J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wall, Nathalie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walter, Eric D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-11-24

Among long-lived radioactive constituents in the Hanford tank waste, Tc presents a unique challenge in that it exists predominantly in the liquid phase, generally in the anionic form of pertechnetate, TcO₄^-, which is highly volatile at low-activity waste (LAW) vitrification melter temperatures and mobile in the Hanford site’s subsurface environment. The complex behavior of Tc under storage, treatment, and immobilization conditions significantly affects its management options, which to-date remain uncertain. In strongly alkaline environments, Tc exists as pertechnetate, TcO₄^- (oxidation state +7), and in the reduced forms (oxidation state < +7) collectively known as non-pertechnetate species. Pertechnetate is a well-characterized, anionic Tc species that can be removed from LAW by anion exchange or solvent extraction methods. There is no definitive information on the origin of the non-pertechnetate Tc species, nor is there a comprehensive description of their composition and behavior. It has been recently proposed that the non-pertechnetate species can comprise Tc(I) metal center and carbonyl or mixed carbonyl nitrosyl ligands stabilizing low-valent Tc. Recent work by our group has significantly expanded this previous work, generating a series of Tc(I) carbonyl compounds and demonstrating that they can be generated from reduction of TcO₄^- in the simulated Hanford tank waste in presence of CO at elevated temperature (Levitskaia et al. 2014). These results are consistent with the previous proposal that [Tc(CO)₃]⁺ species can be present in the Hanford tank waste and suggest that the low Tc(I) oxidation state is stabilized by the π-accepting ability of the CO ligands. The continuation work has been initiated to develop model Tc carbonyl nitrosyl compounds and investigate their potential presence in the Hanford tank wastes. This report summarizes our to-date results.

Evaluating sensitivity of unsaturated soil properties

International Nuclear Information System (INIS)

Abdel-Rahman, R.O.; El-Kamash, A.M.; Nagy, M.E.; Khalill, M.Y.

2005-01-01

The assessment of near surface disposal performance relay on numerical models of groundwater flow and contaminant transport. These models use the unsaturated soil properties as input parameters, which are subject to uncertainty due to measurements errors and the spatial variability in the subsurface environment. To ascertain how much the output of the model will depend on the unsaturated soil properties the parametric sensitivity analysis is used. In this paper, a parametric sensitivity analysis of the Van Genuchten moisture retention characteristic (VGMRC) model will be presented and conducted to evaluate the relative importance of the unsaturated soil properties under different pressure head values that represent various dry and wet conditions. (author)

Chemoselective reduction of 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione by various hydride reagents.

Science.gov (United States)

Kim, Eunjeong; Ma, Eunsook

2007-04-01

The chemoselectivity of rigid cyclic alpha,beta-unsaturated carbonyl group on the reducing agents was influenced by the ring size and steric factor. Cholesterol (cholest-5-en-3beta-ol) and dehydroepiandrosterone (DHEA) were oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone to form 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione. They were reduced with NaBH(4), lithium tri-sec-butylborohydride (l-Selectride), LiAlH(4), 9-borabicyclo[3.3.1]nonane (9-BBN), lithium triethylborohydride (Super-hydride), and BH(3) x (CH(3))(2)S in various conditions, respectively. Reduction of 1,4,6-cholestatrien-3-one and 1,4,6-androstatriene-3,17-dione by NaBH(4) (4 equiv.) produced 4,6-cholestadien-3beta-ol and 4,6-androstadiene-3beta,17beta-diol, respectively. Reduction by l-Selectride (12 equiv.) afforded 4,6-cholestadien-3alpha-ol and 4,6-androstadiene-3alpha,17beta-diol, chemoselectively. Reaction with Super-hydride (12 equiv.) produced 4,6-cholestadien-3-one and 3-oxo-4,6-androstadien-17beta-ol. Reduction of 1,4,6-cholestatrien-3-one by 9-BBN (14 equiv.) produced 1,4,6-cholestatrien-3alpha-ol, but 1,4,6-androstatriene-3,17-dione was not reacted with 9-BBN in the reaction conditions. Reaction of LiAlH(4) (6 equiv.) formed 4,6-cholestadien-3beta-ol and 3-oxo-1,4,6-androstatrien-17beta-ol. Reduction of 1,4,6-cholestatrien-3-one by BH(3) x (CH(3))(2)S (11 equiv.) gave cholestane as major compound and unlike reactivity of cholesterol, 1,4,6-androstatriene-3,17-dione by 8 equiv. of BH(3) x (CH(3))(2)S formed 3-oxo-1,4,6-androstatrien-17beta-ol. LiAlH(4) and BH(3) x (CH(3))(2)S showed relatively low chemoselectivity.

Generation of shock/discontinuity compound structures through magnetic reconnection in the geomagnetic tail

Energy Technology Data Exchange (ETDEWEB)

Weng, C. J. [Department of Physics, National Cheng Kung University, Tainan 701, Taiwan (China); Institute of Space Science, National Central University, Jungli 320, Taiwan (China); Lin, C. C. [Chemical Systems Research Division, Chung-Shan Institute of Science and Technology, Longtan 325, Taiwan (China); Lee, L. C. [Institute of Earth Science, Academia Sinica, Nankang 115, Taiwan (China); Institute of Space Science, National Central University, Jungli 320, Taiwan (China); Chao, J. K. [Institute of Space Science, National Central University, Jungli 320, Taiwan (China)

2012-12-15

We use 1-D hybrid code to simulate the generation and evolution of MHD discontinuities associated with magnetic reconnection in a current sheet. It is found that the leakage of slow shock (SS) downstream particles to upstream region tends to increase the ion parallel temperature and temperature anisotropy with {beta}{sub i||}/{beta}{sub i Up-Tack } Much-Greater-Than 1, where {beta}{sub i||}({beta}{sub i Up-Tack }) is the ion parallel (perpendicular) beta. As a result, the propagation speed of rotational discontinuity (RD) is highly reduced and RD becomes attached to SS, leading to formation of various compound structures in the reconnection outflow region. Four types of compound structure are found in our simulations: (a) RD-SS compound structure: the RD is attached to the leading part of SS, (b) SS-RD (DD) compound structure: RD is attached to the rear part of SS, (c) SS-RD-SS compound structure: RD is trapped inside SS, and (d) switch-off slow shock (SSS) with a rotational wave train. The type of compound structure generated depends on initial ion beta {beta}{sub i0} and magnetic shear angle {phi}. RD tends to move in front of SS to form an RD-SS compound structure for cases with low {beta}{sub i0}. RD stays behind SS and form an SS-RD (DD) compound structure for large {beta}{sub i0}. The SS-RD-SS compound structure is formed for intermediate values of {beta}{sub i0}. When the shear angle is 180 Degree-Sign , SSS with a wave train is formed.

A Moessbauer effect study of the bonding in several organoiron carbonyl clusters

International Nuclear Information System (INIS)

Long, G.J.; O'Brien, J.F.

1988-01-01

After a brief review of the applications of the Moessbauer effect to cyclopentadienyl containing compounds, the chemistry and spectral properties of the various iron carbonyl complexes are described. The electronic properties of a series of trinuclear and tetranuclear organoiron clusters have been investigated through Fenske-Hall self-consistent field molecular orbital calculations, and the results are compared with the Moessbauer effect isomer shifts. A linear correlation is found between the Slater effective nuclear charge, as calculated from the Fenske-Hall partial orbital occupancy factors, and the isomer shift. In these compounds the 4s orbital populations are rather constant. However, the cis and trans isomers of [CpFe(CO) 2 ] 2 have a significantly lower 4s orbital populations. In this case, the reduced 4s population must be accounted for by adding it to the effective nuclear charge to obtain a good correlation with the isomer shift. (orig.)

Catalytic production of metal carbonyls from metal oxides

Science.gov (United States)

Sapienza, Richard S.; Slegeir, William A.; Foran, Michael T.

1984-01-01

This invention relates to the formation of metal carbonyls from metal oxides and specially the formation of molybdenum carbonyl and iron carbonyl from their respective oxides. Copper is used here in admixed form or used in chemically combined form as copper molybdate. The copper/metal oxide combination or combined copper is utilized with a solvent, such as toluene and subjected to carbon monoxide pressure of 25 atmospheres or greater at about 150.degree.-260.degree. C. The reducing metal copper is employed in catalytic concentrations or combined concentrations as CuMoO.sub.4 and both hydrogen and water present serve as promoters. It has been found that the yields by this process have been salutary and that additionally the catalytic metal may be reused in the process to good effect.

An efficient synthesis of β-amino ketone compounds through one-pot three-component Mannich-type reactions using bismuth nitrate as catalyst

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S. Sheik Mansoor

2015-07-01

Full Text Available Three components one-pot Mannich reaction of aromatic ketone, aromatic aldehyde and aromatic amines has been efficiently catalyzed by recyclable bismuth nitrate (Bi(NO33, BN at ambient temperature to give various β-amino carbonyl compounds in high yields. This method has advantages of mild condition, no environmental pollution, and simple work-up procedures. Most importantly, β-amino carbonyl compounds with ortho-substituted aromatic amines are obtained in acceptable to moderate yields by this methodology.

Analysis of Selected Carbonyl Compounds in Tobacco Samples by Using Pentafluorobenzylhydroxylamine Derivatization and Gas Chromatography-Mass Spectrometry

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Bao Mingliang

2014-09-01

Full Text Available Nous avons mis au point une méthode, à la fois fiable, précise et simple, d’analyse courante des composés carbonylés, en ce compris le formaldéhyde, l’acétaldéhyde, l’acétone, le propionaldéhyde, la méthyléthylcétone (MEC, le butyraldéhyde et le crotonaldéhyde, présents à l’état de traces dans les produits de tabac ouvré. Un échantillon d’un gramme de tabac, additionné d’un mélange de carbonyles marqués d’un isotope en guise de normes internes, a été extrait par l’eau. Une part de l’extrait aqueux a subi un processus de dérivatisation à l’aide de chlorhydrate d’o-(2,3,4,5,6-pentafluorobenzyle-hydroxylamine (PFBHA. Les dérivés carbonylés obtenus à l’aide du PFBHA ont ensuite été extraits par l’hexane et analysés par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC-MS. La précision et l’exactitude de la méthode ont été évaluées au regard d’une cigarette de référence Kentucky « additionnée » 3R4F et de produits de référence sans fumée CORESTA CRP1, CRP2, CRP3 et CRP4. Eu égard aux composés carbonylés analysés, d’excellents taux de précision (5-10% et de récupération (95-107% ont été observés avec divers produits du tabac « additionnés », à l’exception de l’acroléine, qui s’est avérée instable dans tous les produits du tabac testés. L’intervalle linéaire de la méthode mise au point s’est étendu de 0,07 à 36 μg/g avec des limites de quantification variant de 0,10 à 0,15 μg/g. Grâce à la présente méthode, le formaldéhyde (0,31-6,24 μg/g et l’acétaldéhyde (0,84- 17,7 μg/g ont été décelés dans tous les produits de référence testés. L’acétone (0,55-2,12 μg/g a été trouvée dans les produits 3R4F, CRP1, CRP2 et CRP3. Des niveaux décelables de propionaldéhyde n’ont été observés que dans les produits CRP1 et CRP3. Les niveaux de MEC, butyraldéhyde et crotonaldéhyde décelés dans tous

Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

Data.gov (United States)

U.S. Environmental Protection Agency — We show in the present study that the unsaturated aldehydes, 2-E-pentenal, 2-E-hexenal and 3-Z-hexenal, are biogenic volatile organic compound (BVOC) precursors for...

PTR-MS analysis of reference and plant-emitted volatile organic compounds

Science.gov (United States)

Maleknia, Simin D.; Bell, Tina L.; Adams, Mark A.

2007-05-01

Proton transfer reaction-mass spectrometry (PTR-MS) was applied to the analysis of a series of volatile organic compounds (VOCs) that emit from various plants. These include a group of alcohols (methanol, ethanol and butanol), carbonyl-containing compounds (acetic acid, acetone and benzaldehyde), isoprene, acetonitrile, tetrahydrofuran (THF), pyrazine, toluene and xylene and a series of terpenes (p-cymene, camphene, 2-carene, limonene, [beta]-myrcene, [alpha]-pinene, [beta]-pinene, [gamma]-tepinene and terpinolene) and oxygen-containing terpenes (1,8-cineole and linalool). These mass spectral data were compared to an electron ionization (EI) database identifying that not all PTR-MS fragments were common to EI. PTR-MS studies of these reference compounds were utilized to identify VOCs emitted from Eucalyptus grandis leaf at a temperature range of 30-100 °C. In addition to protonated molecules (M + H)+, abundant proton-bound dimers or trimers were detected for alcohols, acetone, acetonitrile and THF. Abundant fragment ions attributed to the loss of water from these proton-bound clusters were also observed. The stability of butyl (C4H9+ m/z 57) and acetyl (CH3CO+ m/z 43) fragment ions directed the proton-transfer reactions of butanol and acetic acid. Abundant (M + H)+ ions were detected for pyrazine, THF, toluene and xylene, as well as for all terpenes except those containing oxygen. For linalool and 1,8-cineole, the loss of water generated an abundant fragment ion at m/z 137. PTR-MS fragmentation patterns for terpenes were proposed for m/z 81 (C6H9+), 93 (C7H9+), 95 (C7H11+), 107 (C8H11+), 109 (C8H13+), 119 (C9H11+), 121 (C9H13+) and 137 (loss of water for oxygen-containing terpenes; C10H17+). The relative abundances of (M + H)+ and fragments for all terpenes (except linalool) were dependent on the drift tube voltage and the optimum voltage for detection of molecular ions was different for various terpenes.

Additive scheme for calculation of solvation enthalpies of heterocyclic aromatic compounds. Sublimation/vaporization enthalpy at 298.15 K

International Nuclear Information System (INIS)

Solomonov, Boris N.; Nagrimanov, Ruslan N.; Mukhametzyanov, Timur A.

2016-01-01

Highlights: • Additivity scheme for solvation enthalpies estimation of heteroaromatic compounds was proposed. • Method for determination of vaporization/sublimation enthalpies directly at 298.15 K was developed. • Solution enthalpies of 25 heteroaromatic compounds were measured. • Vaporization/sublimation enthalpies of 44 heteroaromatic compounds were determined. • Obtained values are in good agreement with the results of conventional methods. - Abstract: Hereby we propose a method for determination of vaporization and sublimation enthalpies of heterocyclic and carbonyl-containing aromatic compounds at 298.15 K. According to this method vaporization and sublimation enthalpies at 298.15 K are determined based on enthalpies of solvation and solution. Solvation enthalpies of heteroatomatic and carbonyl-containing compounds are calculated using an additive scheme from the solvation enthalpy of closest aromatic hydrocarbon and contributions related to the exchange of CH-groups of hydrocarbon with corresponding substituent atoms or groups. Measured solution enthalpies together with calculated solvation enthalpies allowed to calculate corresponding vaporization and sublimation enthalpies at 298.15 K for a large number of heterocyclic and carbonyl-containing compounds. We have also found that in a number of cases instead of solution enthalpy in benzene at 298.15 K fusion enthalpy at the melting temperature can be used. Comparison between literature data and calculated vaporization and sublimation enthalpies demonstrates satisfactory performance of the proposed method.

Additive scheme for calculation of solvation enthalpies of heterocyclic aromatic compounds. Sublimation/vaporization enthalpy at 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Solomonov, Boris N., E-mail: boris.solomonov@kpfu.ru; Nagrimanov, Ruslan N.; Mukhametzyanov, Timur A.

2016-06-10

Highlights: • Additivity scheme for solvation enthalpies estimation of heteroaromatic compounds was proposed. • Method for determination of vaporization/sublimation enthalpies directly at 298.15 K was developed. • Solution enthalpies of 25 heteroaromatic compounds were measured. • Vaporization/sublimation enthalpies of 44 heteroaromatic compounds were determined. • Obtained values are in good agreement with the results of conventional methods. - Abstract: Hereby we propose a method for determination of vaporization and sublimation enthalpies of heterocyclic and carbonyl-containing aromatic compounds at 298.15 K. According to this method vaporization and sublimation enthalpies at 298.15 K are determined based on enthalpies of solvation and solution. Solvation enthalpies of heteroatomatic and carbonyl-containing compounds are calculated using an additive scheme from the solvation enthalpy of closest aromatic hydrocarbon and contributions related to the exchange of CH-groups of hydrocarbon with corresponding substituent atoms or groups. Measured solution enthalpies together with calculated solvation enthalpies allowed to calculate corresponding vaporization and sublimation enthalpies at 298.15 K for a large number of heterocyclic and carbonyl-containing compounds. We have also found that in a number of cases instead of solution enthalpy in benzene at 298.15 K fusion enthalpy at the melting temperature can be used. Comparison between literature data and calculated vaporization and sublimation enthalpies demonstrates satisfactory performance of the proposed method.

Furan- and Thiophene-2-Carbonyl Amino Acid Derivatives Activate Hypoxia-Inducible Factor via Inhibition of Factor Inhibiting Hypoxia-Inducible Factor-1

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Shin-ichi Kawaguchi

2018-04-01

Full Text Available Induction of a series of anti-hypoxic proteins protects cells during exposure to hypoxic conditions. Hypoxia-inducible factor-α (HIF-α is a major transcription factor that orchestrates this protective effect. To activate HIF exogenously, without exposing cells to hypoxic conditions, many small-molecule inhibitors targeting prolyl hydroxylase domain-containing protein have been developed. In addition, suppression of factor inhibiting HIF-1 (FIH-1 has also been shown to have the potential to activate HIF-α. However, few small-molecule inhibitors of FIH-1 have been developed. In this study, we synthesized a series of furan- and thiophene-2-carbonyl amino acid derivatives having the potential to inhibit FIH-1. The inhibitory activities of these compounds were evaluated in SK-N-BE(2c cells by measuring HIF response element (HRE promoter activity. Several furan- and thiophene-2-carbonyl amino acid derivatives inhibited FIH-1 based on correlations among the docking score of the FIH-1 active site, the chemical structure of the compounds, and biological HIF-α/HRE transcriptional activity.

Highvalent and organometallic technetium and rhenium compounds

International Nuclear Information System (INIS)

Oehlke, Elisabeth

2010-01-01

Diagnostic methods in nuclear medicine allow a detailed description of morphological organ structures and their function. The beta emitting isotope Tc-99 has optimal physical properties (140 keV gamma rays, half-life 6 h) and is therefore used for radiopharmaceuticals. The thesis is concerned with the search for new technetium complexes and their reproducible production. The (TcO3) core is of main interest. The second part of the thesis deals with organometallic technetium and rhenium complexes with carbonyl ligands and N-heterocyclic carbenes that show stability in aerobic aqueous solutions.

Bifunctional dendrons for multiple carbohydrate presentation via carbonyl chemistry

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Davide Bini

2014-07-01

Full Text Available The synthesis of new dendrons of the generations 0, 1 and 2 with a double bond at the focal point and a carbonyl group at the termini has been carried out. The carbonyl group has been exploited for the multivalent conjugation to a sample saccharide by reductive amination and alkoxyamine conjugation.

An Exploration on the Suitability of Airborne Carbonyl Compounds Analysis in relation to Differences in Instrumentation (GC-MS versus HPLC-UV and Standard Phases (Gas versus Liquid

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Ki-Hyun Kim

2014-01-01

Full Text Available The relative performance figure of merits was investigated for the two most common analytical methods employed for carbonyl compounds (CC, for example, between high performance liquid chromatography (HPLC-UV detector (with 2,4-dinitrophenylhydrazine (DNPH derivatization and thermal desorption (TD-gas chromatography (GC-mass spectrometry (MS (without derivatization. To this end, the suitability of each method is assessed by computing the relative recovery (RR between the gas- and liquid-phase standards containing a suite of CC such as formaldehyde (FA, acetaldehyde (AA, propionaldehyde (PA, butyraldehyde (BA, isovaleraldehyde (IA, and valeraldehyde (VA along with benzene (B as a recovery reference for the GC method. The results confirm that a TD-GC-MS is advantageous to attain the maximum recovery for the heavier CCs (i.e., with molecular weights (MW above BA−MW ≥ 74. On the other hand, the HPLC-UV is favorable for the lighter CCs (like FA and AA with the least bias. Such compound-specific responses for each platform are validated by relative ordering of CCs as a function of response factor (RF, method detection limit (MDL, and recovery pattern. It is thus desirable to understand the advantages and limitations of each method to attain the CC data with the least experimental bias.

Sterol synthesis. A novel reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide; a new chemical synthesis of 5alpha-cholest-8(14)-en-3beta, 15alpha-diol.

Science.gov (United States)

Parish, E J; Schroepfer, G J

1977-04-01

Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with either lithium triethylboro-hydride or lithium aluminum hydride (4 molar excess) gave 5-alpha-cholest-8(14)-en-3beta,15alpha-diol in high yield. Reduction of the epoxy ester with lithium triethylborodeuteride or lithium aluminum deuteride (4 molar excess) gave [7alpha-2-H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol. Reduction of 2beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with a large excess (24 molar excess) of lithium aluminum hydride gave, in addition to the expected 5alpha-cholest-8(14)-en-3beta,15alpha-diol, a significant yield (33%) of 5alpha-cholest-8(14)-en-3beta-o1. Reduction of the epoxy ester with a large excess (24 molar excess) of lithium aluminum deuteride gave [7alpha-2H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol and 5alpha-cholest-8(14)-en-3beta-o1 which contained two atoms of stably bound deuterium.

Nanostructured palladium tailored via carbonyl chemical route towards oxygen reduction reaction

International Nuclear Information System (INIS)

Luo, Y.; Mora-Hernández, J.M.; Estudillo-Wong, L.A.; Arce-Estrada, E.M.; Alonso-Vante, N.

2015-01-01

Graphical Abstract: Mass-depending morphologies of nanostructured Palladium obtained via the carbonyl chemical route. Display Omitted -- Highlights: •Mass-depending morphology was observed in nanostructured palladium supported on carbon prepared by the carbonyl chemical route. •The Morphological effect of carbon supported Pd was investigated towards ORR. -- Abstract: Carbon supported palladium nanostructures were synthesized via the carbonyl chemical route. Compared with nanostructured platinum, prepared via carbonyl chemical route, Pd nanomaterials showed mass-loading morphology, whereas particle size and morphology of Pt nanostructures was constant. The oxygen reduction reaction (ORR) on nanostructured Pd, with different morphology in both acid and alkaline medium was investigated. A relationship, based on X-ray diffraction structural analysis pattern, transmission electron microscope, with the Pd morphological effect on ORR activity was identified

Penicitroamide, an Antimicrobial Metabolite with High Carbonylization from the Endophytic Fungus Penicillium sp. (NO. 24).

Science.gov (United States)

Feng, Zi-Wei; Lv, Meng-Meng; Li, Xue-Shuang; Zhang, Liang; Liu, Cheng-Xiong; Guo, Zhi-Yong; Deng, Zhang-Shuang; Zou, Kun; Proksch, Peter

2016-10-28

Penicitroamide ( 1 ), a new metabolite with a new framework, was isolated from the ethyl acetate extract of the PDB (Potato Dextrose Broth) medium of Penicillium sp. (NO. 24). The endophytic fungus Penicillium sp. (NO. 24) was obtained from the healthy leaves of Tapiscia sinensis Oliv. The structure of penicitroamide ( 1 ) features a bicyclo[3.2.1]octane core unit with a high degree of carbonylization (four carbonyl groups and one enol group). The chemical structure of penicitroamide ( 1 ) was elucidated by analysis of 1D-, 2D-NMR and MS data. In bioassays, penicitroamide ( 1 ) displayed antibacterial potency against two plant pathogens, Erwinia carotovora subsp. Carotovora (Jones) Bersey, et al. and Sclerotium rolfsii Sacc. with MIC 50 at 45 and 50 μg/mL. Compound 1 also showed 60% lethality against brine shrimp at 10 μg/mL. Penicitroamide ( 1 ) exhibited no significant activity against A549, Caski, HepG2 and MCF-7 cells with IC 50 > 50 μg/mL. Finally, the possible biosynthetic pathway of penicitroamide ( 1 ) was discussed.

Carbonyl[4-(2,6-dimethylphenylaminopent-3-en-2-onato-κ2N,O](triphenylphosphine-κPrhodium(I acetone hemisolvate

Directory of Open Access Journals (Sweden)

Andreas Roodt

2009-12-01

Full Text Available In the title compound, [Rh(C13H16NO(C18H15P(CO]·0.5C3H6O, the Rh atom exhibits a square-planar coordination geometry, being coordinated by the N and O atoms of the bidentate β-diketonato ligand, a P atom from the triphenylphosphine unit and a C atom from the carbonyl group. The asymmetric unit also contains a disordered half-molecule, lying about an inversion center, of the acetone solvate. Intermolecular C—H...O hydrogen bonds are observed between a C—H group of the triphenylphosphine unit and a carbonyl O atom and between the methyl group of the enaminoketonato backbone and the solvent O atom. In addition, an intramolecular interaction is observed between a C—H group of the triphenylphosphine unit and the O atom of the enaminoketonato ligand.

One-pot synthesis of 2H-pyrans by indium(III) chloride-catalyzed reactions. efficient synthesis of pyranocoumarins, pyranophenalenones, and pyranoquinolinones

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Rok; Kim, Do Hoon; Shim, Jae Jin; Kim, Seog K.; Park, Jung Hag; Cha, Jin Soon; Lee, Chong Soon [Yeungnam Univ., Kyongsan (Korea, Republic of)

2002-08-01

An efficient synthesis of 2H-pyrans is achieved by indium (III) chloride-catalyzed reactions of 1,3-dicarbonyl compounds with a variety of {alpha}.{beta}-unsaturated aldehydes in moderates yields. This method has been applied to the synthesis of pyranocoumarins, pyranophenaleneones, and pyranoquinolinone alkaloids.

Reactions of 5-[1-(2-phenylmethylidene]-3-phenylimidazolidine-2,4-diones with some organometallic reagents

Directory of Open Access Journals (Sweden)

Teresa A. R. Akeng'a

2005-06-01

Full Text Available The reaction of Grignard reagents with 5-[1-(2-chlorophenylmethylidene]-3-phenylimidazolidine-2,4-dione, 4, and 5-[1-(2-bromophenylmethylidene]-3-phenylimidazolidine-2,4-dione, 5, gave exclusively 1,2-addition products, 6-8, in 70-80% yields. Lithium dibutylcuprate reacted with 4 to yield exclusively 1,2-addition product 9 (92%. No conjugate or 1,4-addition products were obtained. These results indicate that 5-[1-(2-phenylmethylidene]-3-phenylimidazolidine-2,4-diones do not react like normal unsaturated carbonyl compounds.

6-Oxocyclohex-1-ene-1-carbonyl-coenzyme A hydrolases from obligately anaerobic bacteria: characterization and identification of its gene as a functional marker for aromatic compounds degrading anaerobes.

Science.gov (United States)

Kuntze, Kevin; Shinoda, Yoshifumi; Moutakki, Housna; McInerney, Michael J; Vogt, Carsten; Richnow, Hans-Hermann; Boll, Matthias

2008-06-01

In anaerobic bacteria, most aromatic growth substrates are channelled into the benzoyl-coenzyme A (CoA) degradation pathway where the aromatic ring is dearomatized and cleaved into an aliphatic thiol ester. The initial step of this pathway is catalysed by dearomatizing benzoyl-CoA reductases yielding the two electron-reduction product, cyclohexa-1,5-diene-1-carbonyl-CoA, to which water is subsequently added by a hydratase. The next two steps have so far only been studied in facultative anaerobes and comprise the oxidation of the 6-hydroxyl-group to 6-oxocyclohex-1-ene-1-carbonyl-CoA (6-OCH-CoA), the addition of water and hydrolytic ring cleavage yielding 3-hydroxypimelyl-CoA. In this work, two benzoate-induced genes from the obligately anaerobic bacteria, Geobacter metallireducens (bamA(Geo)) and Syntrophus aciditrophicus (bamA(Syn)), were heterologously expressed in Escherichia coli, purified and characterized as 6-OCH-CoA hydrolases. Both enzymes consisted of a single 43 kDa subunit. Some properties of the enzymes are presented and compared with homologues from facultative anaerobes. An alignment of the nucleotide sequences of bamA(Geo) and bamA(Syn) with the corresponding genes from facultative anaerobes identified highly conserved DNA regions, which enabled the discrimination of genes coding for 6-OCH-CoA hydrolases from those coding for related enzymes. A degenerate oligonucleotide primer pair was deduced from conserved regions and applied in polymerase chain reaction reactions. Using these primers, the expected DNA fragment of the 6-OCH-CoA hydrolase genes was specifically amplified from the DNA of nearly all known facultative and obligate anaerobes that use aromatic growth substrates. The only exception was the aromatic compound-degrading Rhodopseudomonas palustris, which uniquely uses a modified benzoyl-CoA degradation pathway. Using the oligonucleotide primers, the expected DNA fragment was also amplified in a toluene-degrading and a m

Synthesis and research of derived oxazol-5-ones based on α,β – unsaturated ketones

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Сергей Александрович Петров

2015-11-01

Full Text Available The article deals with the production of new fluorescent dyes derived oxazol-5-ones based on α, β-unsaturated ketones, as well as confirmation of the structure of the compounds obtained using NMR and IR spectroscopy. The dyes of this series are relevant because one of the important practical problems in organic chemistry and chemical technology is currently seeking new fluorescent dyes for dyeing polyester materials and polymers

Steam stripping of the unsaturated zone of contaminated sub-soils: the effect of diffusion/dispersion in the start-up phase

NARCIS (Netherlands)

Brouwers, Jos; Gilding, B.H.

2006-01-01

The unsteady process of steam stripping of the unsaturated zone of soils contaminated with volatile organic compounds (VOCs) is addressed. A model is presented. It accounts for the effects of water and contaminants remaining in vapour phase, as well as diffusion and dispersion of contaminants in

Selective transformation of carbonyl ligands to organic molecules: Progress report, 1 September 1986--31 August 1989

Energy Technology Data Exchange (ETDEWEB)

Cutler, A.R.

1989-04-18

Studies on anionic phosphido alkyl and acetyl complexes Cp(CO)(PPh/sub 2/)Fe /minus/ R/sup /minus// (1) and In(CO)(PPh/sub 2/)Fe /minus/ R/sup /minus// (2) (R = CH/sub 3/ (a), COCH/sub 3/ (b); In = /eta//sup 5/-indenyl) and their neutral phosphine derivatives Cp(CO)(PPh/sub 2/H)Fe /minus/ R (3) and In(CO)(PPh/sub 2/H)Fe /minus/ R (4) are complete. Attempts to carbonylate 1a and 2a to 1b and 2b failed; also, 3a and 4a resist carbonylation. Reacting 1b with MeI affords a neutral PPh/sub 2/Me acetyl compound 5, whereas MeOSO/sub 2/CF/sub 3/ gives the Fischer carbene complex Cp(PPh/sub 2/)(CO) Fe = C(OMe)CH/sub 3/ (6). Carbene 6 isomerizes to 5 at room temperature. Reaction conditions have been optimized for tenerating vinylidene compounds In/sub 2/(CO)/sub 3/Fe/sub 2/ ..mu..-(C = CHR) from InFe(CO)/sub 2//sup /minus// and In(CO)/sub 2/Fe /minus/ CH/sub 2/R (R = H, Me, OMe). The bimetallic carbonylation procedure for converting Fp/sup /minus//(Li/sup +/, Na/sup +/, PPN/sup +/) and In(CO)/sub 2/Fe /minus/ CH/sub 3/ to InCp(CO)/sub 3/Fe/sub 2/(COCH/sub 3//sup /minus//) and then regioselectively to FpCOCH/sub 3/ (1 atm CO) has been optimized. Studies are finished on the diastereofacial selectivity observed during reduction of the alkoxycarbenes Cp(P(OR)/sub 3/)(CO)Fe = C(OCH/sub 3/)CH/sub 3//sup +/ (R = Me, Ph) with borohydride reagents R/sub 3/BH/sup /minus// (Li/sup +/, Na/sup +/, K/sup +/) and with (PPh/sub 3/CuH)/sub 6/. A survey of the Rh(I)-catalyzed hydrosilation of a variety of iron acyl complexes has been concluded.

Active-site-directed inactivation of Aspergillus oryzae beta-galactosidase with beta-D-galactopyranosylmethyl-p-nitrophenyltriazene.

Science.gov (United States)

Mega, T; Nishijima, T; Ikenaka, T

1990-04-01

beta-D-Galactopyranosylmethyl-p-nitrophenyltriazene (beta-GalMNT), a specific inhibitor of beta-galactosidase, was isolated as crystals by HPLC and its chemical and physicochemical characteristics were examined. Aspergillus oryzae beta-galactosidase was inactivated by the compound. We studied the inhibition mechanism in detail. The inhibitor was hydrolyzed by the enzyme to p-nitroaniline and an active intermediate (beta-galactopyranosylmethyl carbonium or beta-galactopyranosylmethyldiazonium), which inactivated the enzyme. The efficiency of inactivation of the enzyme (the ratio of moles of inactivated enzyme to moles of beta-GalMNT hydrolyzed by the enzyme) was 3%; the efficiency of Escherichia coli beta-galactosidase was 49%. In spite of the low efficiency, the rate of inactivation of A. oryzae enzyme was not very different from that of the E. coli enzyme, because the former hydrolyzed beta-GalMNT faster than the latter did. A. oryzae beta-galactosidase was also inactivated by p-chlorophenyl, p-tolyl, and m-nitrophenyl derivatives of beta-galactopyranosylmethyltriazene. However, E. coli beta-galactosidase was not inactivated by these triazene derivatives. The results showed that the inactivation of A. oryzae and E. coli beta-galactosidases by beta-GalMNT was an enzyme-activated and active-site-directed irreversible inactivation. The possibility of inactivation by intermediates produced nonenzymatically was ruled out for E. coli, but not for the A. oryzae enzyme.

Unsaturated fatty acids in the diet of inpatients

OpenAIRE

KONHEFROVÁ, Veronika

2015-01-01

The thesis with the name "Unsaturated fatty acids in the diet of inpatients" is divided into a theoretical and a research parts. The theoretical part is focused on sorting out lipids and the recommended daily dosing. Next there are described the chemical structure of fatty acids and basic differences between saturated (SFA) and unsaturated (trans and cis) fatty acids. The biggest part of the theory is formed by the unsaturated fatty acids, their characteristics, food source and their effect o...

Volatile organic compound analysis in wood combustion and meat cooking emissions

International Nuclear Information System (INIS)

Zielinska, B.; McDonald, J.

1999-01-01

Residential wood combustion and meat cooking emissions were each analyzed for volatile organic compounds (VOC). Emissions were diluted 60--100 times, cooled to ambient temperature, and allowed 80 seconds for condensation prior to collection with the aid of a DRI-constructed dilution stack sampler. Fireplace and wood-stove emissions testing was conducted at the DRI facilities. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Meat emissions testing was conducted at the CE-CERT stationary emissions lab, University of California, Riverside. Meat type, fat content, and cooking appliance were changed in different tests. VOCs were collected using stainless-steel 6 L canisters and Tenax cartridges, whereas for carbonyl compound collection 2,4-dinitrophenylhydrazine (DNPH)-impregnated C 18 SepPack cartridges were used. Analysis of VOC collected with canisters and Tenax cartridges was conducted by Gas Chromatography/Mass Spectrometry (GC/MS) and by GC/FID/ECD (flame ionization detection/electron capture detection). DNPH-impregnated cartridges were analyzed for fourteen C 1 --C 7 carbonyl compounds, using the HPLC method. The results of these measurements are discussed

Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

Science.gov (United States)

Lee, M T; Ahmed, T; Haddad, R; Friedman, M E

1989-01-01

Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

Volatile organic compound measurements in the California/Mexico border region during SCOS97

International Nuclear Information System (INIS)

Zielinska, B.; Sagebiel, J.; Harshfield, G.; Pasek, R.

2001-01-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone Study in the summer of 1997 (SCOS97). Integrated 3-h samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during intensive operational periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6-l canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C18 SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C 2 -C 12 ), CO, CO 2 , CH 4 , methyl t-butyl ether (MTBE), and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for 14 C 1 -C 7 carbonyl compounds. The concentrations of all species were higher at Mexicali than in Rosarito. A good correlation between total non-methane hydrocarbons (TNMHC), CO, and other pollutants associated with motor vehicle emissions observed for Mexicali indicates that the main source of TNMHC at this site is vehicular traffic

Predicting personal exposure to airborne carbonyls using residential measurements and time/activity data

Science.gov (United States)

Liu, Weili; Zhang, Junfeng (Jim); Korn, Leo R.; Zhang, Lin; Weisel, Clifford P.; Turpin, Barbara; Morandi, Maria; Stock, Tom; Colome, Steve

As a part of the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study, 48 h integrated residential indoor, outdoor, and personal exposure concentrations of 10 carbonyls were simultaneously measured in 234 homes selected from three US cities using the Passive Aldehydes and Ketones Samplers (PAKS). In this paper, we examine the feasibility of using residential indoor concentrations to predict personal exposures to carbonyls. Based on paired t-tests, the means of indoor concentrations were not different from those of personal exposure concentrations for eight out of the 10 measured carbonyls, indicating indoor carbonyls concentrations, in general, well predicted the central tendency of personal exposure concentrations. In a linear regression model, indoor concentrations explained 47%, 55%, and 65% of personal exposure variance for formaldehyde, acetaldehyde, and hexaldehyde, respectively. The predictability of indoor concentrations on cross-individual variability in personal exposure for the other carbonyls was poorer, explainingexposure concentrations. It was found that activities related to driving a vehicle and performing yard work had significant impacts on personal exposures to a few carbonyls.

Carbonyl carbon transverse relaxation dispersion measurements and ms-{mu}s timescale motion in a protein hydrogen bond network

Energy Technology Data Exchange (ETDEWEB)

Ishima, Rieko [National Institute of Dental and Craniofacial Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Molecular Structural Biology Unit (United States); Baber, James; Louis, John M.; Torchia, Dennis A. [National Institute of Dental and Craniofacial Research, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Molecular Structural Biology Unit (United States)

2004-06-15

A constant-time, Carr-Purcell-Meiboom-Gill (CPMG) transverse relaxation, R{sub 2}, dispersion experiment for carbonyl carbons was designed and executed to detect {mu}s-ms time-scale dynamics of protein backbone carbonyl sites. Because of the large (ca. 55 Hz) C{sub {alpha}}-C' J-coupling, the carbonyl signal intensity is strongly modulated as the spacing between CPMG pulses is varied, in uniformly {sup 13}C enriched proteins, unless care is taken to minimize the perturbation of the C{sub {alpha}} magnetization by the CPMG pulses. CPMG pulse trains consisting of either a band-selective pulse, such as RE-BURP, or rectangular (with an excitation null in the C{sub {alpha}} region of the spectrum) pulses were employed in order to minimize C' signal modulation by C{sub {alpha}}-C' J-coupling. The performance of these types of CPMG refocusing pulses was assessed by computer simulation, and by comparing dispersion profiles measured for (1) uniformly [{sup 13}C,{sup 15}N, {sup 2}H] ({sup 2}H at non-labile hydrogen sites) labeled, and (2) uniformly {sup 15}N/selectively-{sup 13}C' labeled samples of HIV-1 protease bound to a potent inhibitor, DMP323. In addition, because the uniformly {sup 13}C/{sup 15}N/{sup 2}H labeled sample was well suited to measure {sup 15}N and {sup 1}H R{sub 2} dispersion as well as {sup 13}C' dispersion, conformational exchange in the inter subunit {beta}-sheet hydrogen-bond network of the inhibitor-bound protease was elucidated using relaxation dispersion data of all three types of nuclei.

Personal exposure and health risk assessment of carbonyls in family cars and public transports-a comparative study in Nanjing, China.

Science.gov (United States)

Xu, Huaizhou; Zhang, Qin; Song, Ninghui; Guo, Min; Zhang, Shenghu; Ji, Guixiang; Shi, Lili

2017-11-01

To evaluate passenger health risks associated with inhalation exposure to carbonyl compounds mainly emitted from decoration materials of vehicles, we tested the carbonyl concentrations in interior air of 20 family cars, 6 metro lines, and 5 buses in the city of Nanjing. To assess non-carcinogenic health risks, we compared the data to the health guidelines of China, US Environmental Protection Agency (EPA), and Office of Environmental Health Hazard Assessment (OEHHA), respectively. To assess carcinogenic risks, we followed a standard approach proposed by the OEHHA to calculate lifetime cancer risks (LCR) of formaldehyde and acetaldehyde for various age groups. The results showed that there are formaldehyde, acetaldehyde, and acrolein concentrations in 40, 35, and 50% of family car samples exceeded the reference concentrations (RfCs) provided by Chinese guidelines (GB/T 27630-2011 and GB/T 18883-2002). Whereas, in the tested public transports, concentrations of the three carbonyls were all below the Chinese RfCs. Fifty and 90% of family cars had formaldehyde and acrolein concentrations exceeding the guidelines of OEHHA. Only one public transport sample (one bus) possesses formaldehyde and acetaldehyde concentrations above the chronic inhalation reference exposure limits (RELs). Furthermore, the assessments of carcinogenic risk of formaldehyde and acetaldehyde showed that lifetime cancer risks were higher than the limits of EPA for some family cars and public transports. In the study, buses and metros appear to be relatively clean environments, with total carbonyl concentrations that do not exceed 126 μg/m 3 . In family cars, carbonyl levels showed significant variations from 6.1 to 811 μg/m 3 that was greatly influenced by direct emissions from materials inside the vehicles. Public transports seemed to be the first choice for resident trips as compared to family cars. Graphical abstract ᅟ.

Fluoride-Mediated Dephosphonylation of α-Diazo-β-carbonyl Phosphonates.

Science.gov (United States)

Phatake, Ravindra S; Mullapudi, Venkannababu; Wakchaure, Vivek C; Ramana, Chepuri V

2017-01-20

The possibility of fluoride-mediated selective dephosphonylation of α-diazo-β-carbonyl phosphonates such as the Ohira-Bestmann reagent has been proposed and executed. The resulting α-diazocarbonyl intermediates undergo a (3 + 2)-cycloaddition at room temperature with conjugated olefins and benzynes. Interestingly, under the current conditions, the resulting cycloaddition products underwent either N-acylation (with excess α-diazo-β-carbonyl phosphonates) or Michael addition (with conjugated olefins).

Inhalation exposure and health risk levels to BTEX and carbonyl compounds of traffic policeman working in the inner city of Bangkok, Thailand

Science.gov (United States)

Kanjanasiranont, Navaporn; Prueksasit, Tassanee; Morknoy, Daisy

2017-03-01

Benzene, toluene, ethylbenzene and xylenes (BTEX) and carbonyl compounds (CCs) are recognized traffic-related air pollutants in urban environments and are the focus of this study. In Bangkok, the BTEX and CC concentrations in both ambient air and personal exposure samples were studied during two periods (April-May and August-September 2014) at four different sampling sites around the Pathumwan District (three intersections and one T-junction). Traffic policemen, representing the high-exposure group for these toxic air pollutants, were observed, and the health risk to these workers was evaluated. Toluene was the predominant aromatic compound in the ambient and personal exposure samples. The maximum average ambient concentration of BTEX was 2968.96 μg/m3. Formaldehyde and acetaldehyde were the most abundant CCs at all of the sampling sites, with the greatest mean concentrations of these substances being 21.50 μg/m3 and 64.82 μg/m3, respectively. In the personal exposure samples, the highest levels of BTEX, formaldehyde and acetaldehyde concentrations were 2231.85 μg/m3, 10.61 μg/m3, and 16.03 μg/m3, respectively. In terms of risk assessment, benzene posed the greatest cancer risk (at the 95% CI), followed by toluene, acetaldehyde and formaldehyde (1.15E-02, 5.14E-03, 2.84E-04, and 2.52E-04, respectively). Three risk factors were investigated to reduce the total cancer risk levels: reducing the chemical concentration, exposure time and exposure duration. The use of a mask (chemical concentration) was the best way to reduce the risk to traffic police. However, the risk value of benzene (average 1.57E-05) was still higher than an acceptable value when using a mask.

Millimeter wave spectra of carbonyl cyanide

Science.gov (United States)

Bteich, S. B.; Tercero, B.; Cernicharo, J.; Motiyenko, R. A.; Margulès, L.; Guillemin, J.-C.

2016-07-01

Context. More than 30 cyanide derivatives of simple organic molecules have been detected in the interstellar medium, but only one dicarbonitrile has been found and that very recently. There is still a lack of high-resolution spectroscopic data particularly for dinitriles derivatives. The carbonyl cyanide molecule is a new and interesting candidate for astrophysical detection. It could be formed by the reaction of CO and CN radicals, or by substitution of the hydrogen atom by a cyano group in cyanoformaldehyde, HC(=O)CN, that has already been detected in the interstellar medium. Aims: The available data on the rotational spectrum of carbonyl cyanide is limited in terms of quantum number values and frequency range, and does not allow accurate extrapolation of the spectrum into the millimeter-wave range. To provide a firm basis for astrophysical detection of carbonyl cyanide we studied its millimeter-wave spectrum. Methods: The rotational spectrum of carbonyl cyanide was measured in the frequency range 152-308 GHz and analyzed using Watson's A- and S-reduction Hamiltonians. Results: The ground and first excited state of v5 vibrational mode were assigned and analyzed. More than 1100 distinct frequency lines of the ground state were fitted to produce an accurate set of rotational and centrifugal distortion constants up to the eighth order. The frequency predictions based on these constants should be accurate enough for astrophysical searches in the frequency range up to 500 GHz and for transition involving energy levels with J ≤ 100 and Ka ≤ 42. Based on the results we searched for interstellar carbonyl cyanide in available observational data without success. Thus, we derived upper limits to its column density in different sources. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of

Synthesis of porphyryl boronates with (un)saturated side-chains

OpenAIRE

SENGE, MATHIAS; SERGEEVA, NATALIA

2008-01-01

PUBLISHED Porphyrins with (un)saturated side?chains containing boron residues were developed as synthons for porphyrin functionalization. Porphyrins with mono and bis-substituted unsaturated boronyl residues were prepared in good yields (52?66 %) using a cross?metathesis approach in the presence of Grubbs I-generation catalysts. In all cases complete E?stereoselectivity (100 %) was observed. Furthermore, formal cross?metathesis products with ?,??unsaturated chains smoothly underwent additi...

Organometallic and Bioorganometallic Chemistry - Ferrocene and Metal Carbonyls

Directory of Open Access Journals (Sweden)

Čakić Semenčić, M.

2011-02-01

Full Text Available Organometallic chemistry deals with compounds containing metal-carbon bonds. Basic organometallics derived from the s- and p-block metals (containing solely σ-bonds were understood earlier, while organometallic chemistry of the d- and f-block has developed much more recently. These compounds are characterized by three types of M-C bonds (σ, π and δand their structures are impossible to deduce by chemical means alone; fundamental advances had to await the development of X-ray diffraction, as well as IR- and NMR-spectroscopy. On the other hand, elucidation of the structure of e. g. vitamin B12 and ferrocene (discovered in 1951 contributed to progress in these instrumental analytical methods, influencing further phenomenal success of transition-metal organometallic chemistry in the second half of the twentieth century. The most thoroughly explored fields of application of organometallics were in the area of catalysis, asymmetric synthesis, olefin metathesis, as well as organic synthesis and access to new materials and polymers.The most usual ligands bound to d- and f-metals are carbon monoxide, phosphines, alkyls, carbenes and arenes, and in this review the bonding patterns in the metal carbonyls and ferrocene are elaborated. The common characteristics of these two classes are two-component bonds. The CO-M bonds include (i donation from ligand HOMO to vacant M d-orbitals (σ-bond, and (ii back-donation from the filled M d-orbitals in the ligand LUMO (π-bond. Similar (but much more complicated ferrocene contains delocalized bonds consisting of electron donation from Cp to Fe (σ-bonds- and π-bonding and δ-back-bonding from metal to Cp. In such a way ferrocene, i. e. (η5-Cp2Fe contains 18 bonding electrons giving to this compound "superaromatic" properties in the sense of stability and electrophilic substitution. In contrast to benzenoid aromatic compounds reactions in two Cp-rings can occur giving homo- and heteroannularly mono-, two-… per

Nuclear magnetic resonance and LC/MS characterization of native and new mass-labeled fluorinated telomer alcohols, acids and unsaturated acids

Energy Technology Data Exchange (ETDEWEB)

Arsenault, G.; Chittim, B.; McAlees, A.; Yeo, B. [Wellington Laboratories Inc., Guelph, ON (Canada); Ellis, D.; Mabury, S.; Stock, N. [Toronto Univ., ON (Canada); Halldorson, T.; Tomy, G. [Dept. of Fisheries and Oceans, Winnipeg, MB (Canada); McCrindle, R. [Guelph Univ., ON (Canada)

2004-09-15

A variety of fluorinated compounds are used in a multitude of consumer products because of their ability to repel water and oil, resistance to heat, and chemical inertness. Recently, scientists and regulators have begun raising concerns about the potential health and environmental impact of perfluorinated compounds. Exposure to perfluoroalkyl acids, such as Perfluorooctanoic acid (PFOA), has been identified as a potential human health concern. A study has shown that telomer alcohols such as 2-perfluorooctylethanol can be metabolized by living organisms or biodegrade under environmental conditions to sequentially give the saturated fluorinated telomer acid (2- perfluorooctylethanoic acid), then the unsaturated telomer acid (2H-Perfluorooct-2-enoic acid), and eventually PFOA. Additional experimental work is necessary to determine the extent, if any, to which telomer product degradation may be a source of PFOA. The analysis for fluorinated compounds in environmental samples is performed, primarily, using LC/MS techniques. These analyses have been hindered by the lack of any commercially available mass-labeled fluorinated compounds for use as surrogates and thus may be restricting the amount of research conducted in this area. We have now synthesized the mass-labeled perfluoroalkyl telomer alcohols and the corresponding acids and unsaturated acids. We report in this study their 1H-, 2H-, 19F- and 13C-NMR characterizations along with GC/MS and LC/MS data and evaluation of their use as surrogate standards.

Non-phenolic antioxidant compounds from Buddleja asiatica.

Science.gov (United States)

el-Sayed, Mortada M; Abdel-Hameed, El-Sayed S; Ahmed, Wafaa S; el-Wakil, Eman A

2008-01-01

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1-diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 microg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-beta-D-glucopyranosyl-2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3 beta,23,28-triol (2), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3,23,28-triol (3), and 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl-acid-olean-11,13(18)-diene-3 beta,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.

Line profile analyses of rhodium metal obtained by decomposition of rhodium carbonyl

International Nuclear Information System (INIS)

Chandra, D.; Mandalia, H.; Garner, M.L.; Blakely, M.K.; Lau, K.H.

1995-01-01

Metal carbonyls are important for chemical vapor deposition (CVD) of metals and alloys and formation of high surface area metallic particles which have potential applications as catalysts. Rhodium carbonyl [Rh 6 (CO) 16 ] produces high surface area metallic particles whose structure has been reported as monoclinic (I2/a) with lattice dimensions, a=17.00(±0.03)Angstrom, b=9.78(±0.02)Angstrom, c=17.53(±0.03)Angstrom and Β=121 degrees 45' ± 30' at room temperature. Generally, metal carbonyl crystals dissociate under vacuum as carbonyl gas and decompose to metallic crystals and carbon monoxide at higher temperatures. However, the behavior of rhodium carbonyl crystals is different; they decompose directly to metallic rhodium without the formation of rhodium carbonyl gas in vacuum. Several residual fine grains of rhodium metal are found after the decomposition in vacuum at relatively low temperatures. The metallic samples of rhodium were obtained from vapor pressure experiments using torsion Knudsen-effusion apparatus. X-ray diffraction analyses performed on these gains showed severely broadened Bragg reflections indicative of small particle size and/or lattice microgram. In this study, a comparison of lattice strains and domain sizes obtained by integral breadth and Fourier methods has been made. In addition a comparison of the lattice strains and domain sizes has been made between the Cauchy, Gaussian, Cauchy-Gaussian and Aqua integral breadth methods

A biotin enrichment strategy identifies novel carbonylated amino acids in proteins from human plasma

DEFF Research Database (Denmark)

Havelund, Jesper F; Wojdyla, Katarzyna; Davies, Michael J

2017-01-01

Protein carbonylation is an irreversible protein oxidation correlated with oxidative stress, various diseases and ageing. Here we describe a peptide-centric approach for identification and characterisation of up to 14 different types of carbonylated amino acids in proteins. The modified residues...... in vitro metal ion-catalysed oxidation. Furthermore, we assigned 133 carbonylated sites in 36 proteins in native human plasma protein samples. The optimised workflow enabled detection of 10 hitherto undetected types of carbonylated amino acids in proteins: aldehyde and ketone modifications of leucine...

Formation of neutral and charged gold carbonyls on highly facetted gold nanostructures

Science.gov (United States)

Chau, Thoi-Dai; Visart de Bocarmé, Thierry; Kruse, Norbert; Wang, Richard L. C.; Kreuzer, Hans Jürgen

2003-12-01

We show that gold mono- and di-carbonyls are formed on gold field emitter tips during interaction with carbon monoxide gas at room temperature and in the presence of high electrostatic fields. The experiments are done in a time-of-flight atom probe to obtain mass spectra. The yield of monocarbonyl cations is about twice that of di-carbonyl ions. Density functional theory calculations are reported that explain the field stabilization of adsorbed carbonyls and the desorption yield of their cations.

Protective efficacy of various carbonyl compounds and their metabolites, and nutrients against acute toxicity of some cyanogens in rats: biochemical and physiological studies

Directory of Open Access Journals (Sweden)

Bhattacharya Rahul

2017-09-01

Full Text Available Cyanogens are widely used in industries and their toxicity is mainly due to cyanogenesis. The antidotes for cyanide are usually instituted for the management of cyanogen poisoning. The present study reports the protective efficacy of 14 carbonyl compounds and their metabolites, and nutrients (1.0 g/kg; oral; +5 min against acute oral toxicity of acetonitrile (ATCN, acrylonitrile (ACN, malononitrile (MCN, propionitrile (PCN, sodium nitroprusside (SNP, succinonitrile (SCN, and potassium ferricyanide (PFCN in rats. Maximum protection index was observed for alpha-ketoglutarate (A-KG against MCN and PCN (5.60, followed by dihydroxyacetone (DHA against MCN (2.79. Further, MCN (0.75 LD50 caused significant increase in cyanide concentration in brain, liver and kidney and inhibition of cytochrome c oxidase activity in brain and liver, which favorably responded to A-KG and DHA treatment. Up-regulation of inducible nitric oxide synthase by MCN, PCN and SNP, and uncoupling protein by PCN and SNP observed in the brain was abolished by A-KG administration. However, no DNA damage was detected in the brain. MCN and SNP significantly decreased the mean arterial pressure, heart rate, respiratory rate and neuromuscular transmission, which were resolved by A-KG. The study suggests a beneficial effect of A-KG in the treatment of acute cyanogen poisoning.

New lupane triterpenoids from Solidago canadensis that inhibit the lyase activity of DNA polymerase beta.

Science.gov (United States)

Chaturvedula, V S Prakash; Zhou, Bing-Nan; Gao, Zhijie; Thomas, Shannon J; Hecht, Sidney M; Kingston, David G I

2004-12-01

Bioassay-directed fractionation of a methyl ethyl ketone extract of Solidago canadensis L. (Asteraceae), using an assay to detect the lyase activity of DNA polymerase beta, resulted in the isolation of the four new lupane triterpenoids 1-4 and the seven known compounds lupeol, lupeyl acetate, ursolic acid, cycloartenol, cycloartenyl palmitate, alpha-amyrin acetate, and stigmasterol. The structures of the new compounds were established as 3beta-(3R-acetoxyhexadecanoyloxy)-lup-20(29)-ene (1), 3beta-(3-ketohexadecanoyloxy)-lup-20(29)-ene (2), 3beta-(3R-acetoxyhexadecanoyloxy)-29-nor-lupan-20-one (3), and 3beta-(3-hetohexadecanoyloxy)-29-nor-lupan-20-one (4), respectively, on the basis of extensive 1D and 2D NMR spectroscopic interpretation and chemical modification studies. All 11 compounds were inhibitory to the lyase activity of DNA polymerase beta.

Analysis of Rainfall Infiltration Law in Unsaturated Soil Slope

OpenAIRE

Zhang, Gui-rong; Qian, Ya-jun; Wang, Zhang-chun; Zhao, Bo

2014-01-01

In the study of unsaturated soil slope stability under rainfall infiltration, it is worth continuing to explore how much rainfall infiltrates into the slope in a rain process, and the amount of rainfall infiltrating into slope is the important factor influencing the stability. Therefore, rainfall infiltration capacity is an important issue of unsaturated seepage analysis for slope. On the basis of previous studies, rainfall infiltration law of unsaturated soil slope is analyzed. Considering t...

Emissions of Toxic Carbonyls in an Electronic Cigarette

Directory of Open Access Journals (Sweden)

Guthery William

2016-01-01

Full Text Available Electronic cigarettes (e-cigs provide a smoke-free alternative for inhalation of nicotine without the vast array of toxic and carcinogenic combustion products produced by tobacco smoke. Elevated levels of toxic carbonyls may be generated during vaporisation; however, it is unclear whether that is indicative of a fault with the device or is due to the applied conditions of the test. A device, designed and built at this facility, was tested to determine the levels of selected toxic carbonyls. The reservoir was filled with approximately 960 mg of an e-liquid formulation containing 1.8% (w/v nicotine. Devices were puffed 200 times in blocks of 40 using a standardised regime consisting of a 55 mL puff volume; 3 s puff duration; 30 s puff interval; square wave puff profile. Confirmatory testing for nicotine and total aerosol delivery resulted in mean (n = 8 values of 10 mg (RSD 12.3% and 716 mg (RSD 11.2%, respectively. Emissions of toxic carbonyls were highly variable yet were between < 0.1% and 22.9% of expected levels from a Kentucky Reference Cigarette (K3R4F puffed 200 times under Health Canada Intense smoking conditions. It has been shown that a device built to a high specification with relatively consistent nicotine and aerosol delivery emits inconsistent levels of carbonyls. The exposure is greatly reduced when compared with lit tobacco products. However, it was observed that as the reservoirs neared depletion then emission levels were significantly higher

Computational study of the hydrolysis of carbonyl sulphide: Thermodynamics and kinetic constants estimation using ab initio calculations

International Nuclear Information System (INIS)

Vidal-Vidal, Á.; Pérez-Rodríguez, M.; Piñeiro, M.M.

2017-01-01

Highlights: • OCS hydrolysis equilibrium constants were calculated using QM composite methods. • CBS-QB3 was found to be the most adequate method for OCS thermodynamic calculations. • Calculated hydrolysis yields decrease when temperature increases. • The isotopic effect is less significant than temperature or initial concentration dependences. - Abstract: Carbonyl sulphide is the predominant sulphur compound in the atmosphere, contributing to the formation of aerosol particles affecting global climate. Human activity has significantly increased its total amount since the beginning of the Industrial Revolution due to its presence in petroleum and coal, reason why it is necessary to understand and control its emissions. On the other hand, carbonyl sulphide is an undesired substance for catalysis in important industrial processes. Hydrolysis is the most promising among the different strategies to reduce its presence, giving as products carbon dioxide and hydrogen sulphide. In the present work, the mechanism of reaction of carbonyl sulphide hydrolysis process in gas phase was studied from 400 K to 1500 K, equilibrium constants were obtained and reaction yields were estimated, by means of composite quantum-computational methods. Good agreement with literature experimental results confirms the suitability of the chosen methods, specially CBS-QB3, in supporting the reaction mechanism, giving accurate equilibrium constant values, and obtaining realistic yields. The effect of isotopic substitution in OCS was also studied, from 300 K to 1500 K, being much less significant than temperature dependence.

Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations

Directory of Open Access Journals (Sweden)

Konstantinos E. Farsalinos

2018-01-01

Full Text Available Carbonyl emissions from tobacco cigarettes represent a substantial health risk contributing to smoking-related morbidity and mortality. As expected, this is an important research topic for tobacco harm reduction products, in an attempt to compare the relative risk of these products compared to tobacco cigarettes. In this study, a systematic review of the literature available on PubMed was performed analyzing the studies evaluating carbonyl emissions from e-cigarettes. A total of 32 studies were identified and presented. We identified a large diversity of methodologies, with substantial discrepancies in puffing patterns, aerosol collection and analytical methods as well as reported units of measurements. Such discrepancies make comparisons difficult, and in some cases the accuracy of the findings cannot be determined. Importantly, control for the generation of dry puffs was not performed in the vast majority of studies, particularly in studies using variable power devices, which could result in testing conditions and reported carbonyl levels that have no clinical relevance or context. Some studies have been replicated, verifying the presence of dry puff conditions. Whenever realistic use conditions were ensured, carbonyl emissions from e-cigarettes were substantially lower than tobacco cigarette smoke, while newer generation (bottom-coil, cotton wick atomizers appeared to emit minimal levels of carbonyls with questionable clinical significance in terms of health risk. However, extremely high levels of carbonyl emissions were reported in some studies, and all these studies need to be replicated because of potentially important health implications.

Classical endocannabinoid-like compounds and their regulation by nutrients

DEFF Research Database (Denmark)

Kleberg, Karen; Hassing, Helle A.; Hansen, Harald S.

2014-01-01

Endocannabinoid-like compounds are structurally related to the true endocannabinoids but do not contain highly unsaturated fatty acids, and they do not bind the cannabinoid receptors. The classical endocannabinoid-like compounds include N-acylethanolamines and 2-monoacylglycerols......, which are particularly interesting in a nutritional and metabolic context. Exogenously supplied oleoylethanolamide, palmitoylethanolamide, and linoleoylethanolamide have anorexic effects, and the endogenous formation of these N-acylethanolamines in the small intestine may serve an important role...

Synthesis of polyhydroxylated compounds from Derythrose: enzymatic inhibition studies

OpenAIRE

Noro, Jennifer Martins

2015-01-01

Dissertação de mestrado em Química Medicinal This thesis is divided into two parts. At first, two starting synthon compounds were obtained: the benzylidene acetal D-erythrose aldehyde and the unsaturated lactone derived from this aldehyde. Both compounds were obtained following methods reported in the literature. The first part of the work focuses on aldehyde reactions with different primary aliphatic amines, yielding the respective imines. These were reduced to afford the ...

Design and fabrication of microfluidic mixer from carbonyl iron–PDMS composite membrane

KAUST Repository

Li, Jiaxing; Zhang, Mengying; Wang, Limu; Li, Weihua; Sheng, Ping; Wen, Weijia

2010-01-01

This paper introduces a carbonyl iron-PDMS (CI-PDMS) composite magnetic elastomer in which carbonyl iron (CI) particles are uniformly distributed in a PDMS matrix. The CI particles and the PDMS were mixed at different weight ratios and tested

Sorption of agrochemical model compounds by sorbent materials containing beta-cyclodextrin.

Science.gov (United States)

Wilson, Lee D; Mohamed, Mohamed H; Guo, Rui; Pratt, Dawn Y; Kwon, Jae Hyuck; Mahmud, Sarker T

2010-04-01

Polymeric sorbent materials that incorporate beta-cyclodextrin (CD) have been prepared and their sorption behavior toward two model agrochemical contaminant compounds, p-nitrophenol (PNP) and methyl chloride examined. The sorption of PNP was studied in aqueous solution using ultraviolet-visible (UV-Vis) spectroscopy, whereas the sorption of methyl chloride from the gas phase was studied using a Langmuir adsorption method. The sorption results for PNP in solution were compared between granular activated carbon (GAC), modified GAC, CD copolymers, and CD-based mesoporous silica hybrid materials. Nitrogen porosimetry at 77 K was used to estimate the surface area and pore structure properties of the sorbent materials. The sorbents displayed variable surface areas as follows: copolymers (36.2-157 m(2)/g), CD-silica materials (307-906 m(2)/g), surface modified GAC (657 m(2)/g), and granular activated carbon (approximately 10(3) m(2)/g). The sorption capacities for PNP and methyl chloride with the different sorbents are listed in descending order as follows: GAC > copolymers > surface modified GAC > CD-silica hybrid materials. In general, the differences in the sorption properties of the sorbents were related to the following: (i) surface area of the sorbent, (ii) CD content and accessibility, (iii) and the chemical nature of the sorbent material.

Pumping Test Determination of Unsaturated Aquifer Properties

Science.gov (United States)

Mishra, P. K.; Neuman, S. P.

2008-12-01

Tartakovsky and Neuman [2007] presented a new analytical solution for flow to a partially penetrating well pumping at a constant rate from a compressible unconfined aquifer considering the unsaturated zone. In their solution three-dimensional, axially symmetric unsaturated flow is described by a linearized version of Richards' equation in which both hydraulic conductivity and water content vary exponentially with incremental capillary pressure head relative to its air entry value, the latter defining the interface between the saturated and unsaturated zones. Both exponential functions are characterized by a common exponent k having the dimension of inverse length, or equivalently a dimensionless exponent kd=kb where b is initial saturated thickness. The authors used their solution to analyze drawdown data from a pumping test conducted by Moench et al. [2001] in a Glacial Outwash Deposit at Cape Cod, Massachusetts. Their analysis yielded estimates of horizontal and vertical saturated hydraulic conductivities, specific storage, specific yield and k . Recognizing that hydraulic conductivity and water content seldom vary identically with incremental capillary pressure head, as assumed by Tartakovsky and Neuman [2007], we note that k is at best an effective rather than a directly measurable soil parameter. We therefore ask to what extent does interpretation of a pumping test based on the Tartakovsky-Neuman solution allow estimating aquifer unsaturated parameters as described by more common constitutive water retention and relative hydraulic conductivity models such as those of Brooks and Corey [1964] or van Genuchten [1980] and Mualem [1976a]? We address this question by showing how may be used to estimate the capillary air entry pressure head k and the parameters of such constitutive models directly, without a need for inverse unsaturated numerical simulations of the kind described by Moench [2003]. To assess the validity of such direct estimates we use maximum

Deuterium labelling studies with unsaturated acids and nitriles

International Nuclear Information System (INIS)

Desai, U.V.; Mane, R.B.

1986-01-01

α-Deuteriated α,β-unsaturated acids have been prepared by Knoevenagel condensation of aldehydes with deuteriated malonic acid. The decarboxylation of α,β-unsaturated cyano acid with pyridine/D 2 O yields α- and γ-labelled nitriles. The deuterium incorporation is studied by pmr spectroscopy. (author). 8 refs

Vertical hydrochemical profiles in the unsaturated zone of louga ...

African Journals Online (AJOL)

Solutions chemistry of the rainwater and the unsaturated zone interstitial water of Louga (Northern Senegal) local aquifer provide valuable ... together with chemical analysis of the interstitial water carried out through the entire unsaturated ...

Electrokinetic extraction of chromate from unsaturated soils

International Nuclear Information System (INIS)

Mattson, E.D.; Lindgren, E.R.

1993-01-01

Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode

Electrokinetic extraction of chromate from unsaturated soils

Energy Technology Data Exchange (ETDEWEB)

Mattson, E.D. [SAT-UNSAT, Inc., Albuquerque, NM (United States); Lindgren, E.R. [Sandia National Labs., Albuquerque, NM (United States)

1993-11-01

Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode.

Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley

Energy Technology Data Exchange (ETDEWEB)

Sebastiao, K.I. E-mail: kisebas@net.ipen.br; Almeida-Muradian, L.B. E-mail: ligiabi@usp.br; Romanelli, Maria Fernanda; Koseki, Paula Massae; Villavicencio, A.L.C.H. E-mail: villavic@net.ipen.br

2002-03-01

Ionizing radiation is a method for preservation of foods that use the high energy of gamma rays or accelerated electrons, thereby ionizing molecules. The most important precursor of vitamin A is {beta}-carotene, a carotenoid with pro-vitamin A activity. The highly unsaturated chain confers the instability of {beta}-carotene, and some reactions, as isomerisation, can reduce the characteristics of pro-vitamin A. The present study investigated whether increasing doses of 0, 10 and 20 kGy lower the total {beta}-carotene level and if an enhancement of cis-isomers occurred on samples of dehydrated parsley. No differences were observed of either fractions analyzed at doses applied in this study, nor did it contribute to the decrease of vitamin A.

Discovery of novel acetanilide derivatives as potent and selective beta3-adrenergic receptor agonists.

Science.gov (United States)

Maruyama, Tatsuya; Onda, Kenichi; Hayakawa, Masahiko; Matsui, Tetsuo; Takasu, Toshiyuki; Ohta, Mitsuaki

2009-06-01

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of acetanilide-based analogues were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Among these compounds, 2-pyridylacetanilide (2f), pyrimidin-2-ylacetanilide (2u), and pyrazin-2-ylacetanilide (2v) derivatives exhibited potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In particular, compound 2u was found to be the most potent and selective beta3-AR agonist with an EC(50) value of 0.11 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 2f, 2u, and 2v showed significant hypoglycemic activity in a rodent diabetic model.

Movement of radionuclides through unsaturated soils

International Nuclear Information System (INIS)

de Sousa, F.N.C.

1985-01-01

The advantages of the disposal of low-level radioactive wastes in the unsaturated zone above the fluctuations of the water table have been recognized for some time. However, most the numerical models used to simulate the environmental impact of a shallow land burial site assume that the soils surrounding the waste forms are saturated; this assumption may lead, in many cases, to unrealistic large leach and water flow rates. The main purpose of this study was the development of a procedure which could give a reliable prediction on the movement of radionuclides from shallow land burial sites located in the unsaturated zone. In order to accomplish this objective three different soils having different sand, silt, and clay fractions were selected and characterized. These soils were then used to fill a number of flow columns that were used in tests designed to provide input data for the flow and transport models. A one-dimensional finite element model was developed in order to simulate the water flow and radionuclide transport through unsaturated soils. The results obtained showed that the model accurately described the transport of radionuclides through saturated-unsaturated soils. Simulations were done, for all three soils, involving different degrees of soil saturation, and the results showed that assuming the soils are always saturated may lead to nuclide transport times which are orders of magnitude larger than the real ones, depending on the clay percentage present in the soil

A straightforward and efficient method for the synthesis of diversely substituted {beta}-aminoketones and {gamma}-aminoalcohols from 3-(N,N-dimethylamino)propiophenones as starting materials

Energy Technology Data Exchange (ETDEWEB)

Abonia, Rodrigo; Arteaga, Danny; Castillo, Juan; Insuasty, Braulio; Quiroga, Jairo; Ortiz, Alejandro, E-mail: rodrigo.abonia@correounivalle.edu.co [Universidad del Valle, Cali (Colombia). Department of Chemistry. Research Group of Heterocyclic Compounds

2013-09-15

Libraries of novel {beta}-aminoketones and {gamma}-aminoalcohols showing a wide structural diversity were easily obtained from a simple approach, using 3-(N,N-dimethylamino)propiophenone derivatives as key starting material. The procedure involved initially an N-alkylation of secondary benzylamines with propiophenone salts yielding the desired {beta}-aminoketones. Chemical or catalytic reduction of their carbonyl groups provided the final {gamma}-aminoalcohols in good yields. This protocol proved to be convenient as an alternative route for the synthesis of the local anesthetic Falicain Registered-Sign and for the topic antifungal drug Naftifine Registered-Sign . (author)

An Efficient Procedure Based on a MW-Assisted Horner–Wadsworth-Emmons Reaction for the Synthesis of (Z-3,3-Trisubstituted-a,b-unsaturated Esters

Directory of Open Access Journals (Sweden)

Ornella Azzolina

2010-08-01

Full Text Available A microwave-assisted HWE olefination process of readily accessible aryl-alkyl ketones has been developed to provide a rapid access to (Z-3,3-trisubstituted-α,β-unsaturated methyl esters, key building blocks for the synthesis of biologically active compounds.

Organic Compounds Complexify Transport in the Amargosa Desert—The Case for Phytotritiation

Science.gov (United States)

Stonestrom, D. A.; Luo, W.; Andraski, B. J.; Baker, R. J.; Maples, S.; Mayers, C. J.; Young, M. B.

2014-12-01

Civilian low-level radioactive waste containing organic compounds was disposed in 2- to 15-m deep unlined trenches in a 110-m deep unsaturated zone at the present-day USGS Amargosa Desert Research Site. Tritium represents the plurality of disposed activity. A plume of gas-phase contaminants surrounds the disposal area, with 60 distinct volatile organic compounds (VOCs) identified to date. The distribution of tritiated water in the unsaturated zone surrounding the disposal area is highly enigmatic, with orders of magnitude separating observed levels from those predicted by multiphase models of mass and energy transport. Peaks of tritium and VOCs are coincidently located in sediments tens of meters below the root zone, suggesting abiotic stratigraphic control on lateral transport at depth. Surprisingly, the highest observed levels of tritium occur at a depth of about 1.5 m, the base of the creosote-bush plant-community root zone, where levels of waste-derived VOCs are low (approaching atmospheric levels). Bulk water-vapor samples from shallow and deep unsaturated-zone profile hot spots were trapped as water ice in cold fingers immersed in dry ice-isopropyl alcohol filled Dewar flasks, then melted and sequentially extracted by purge-and-trap VOC degassing followed by elution through activated carbon solid-phase extraction (SPE) cartridges. Analysis of tritium activities and mass spectrometer results indicate that over 98% of tritium activity at depth is present as water, whereas about 15% of basal root zone tritium activity is present as organic compounds trapped with the water. Of these, the less-volatile compound group removed by SPE accounted for about 85% of the organic tritium activity, with mass spectrometry identifying 2-ethyl-1-hexanol as the principal compound removed. This plant-produced fatty alcohol is ubiquitous in the root zone of creosote-bush communities and represents a family of hydroxyl-containing plant produced compounds that give the plants their

Features of the behavior of 4-amino-5-carboxamido-1,2,3-triazole in multicomponent heterocyclizations with carbonyl compounds

Directory of Open Access Journals (Sweden)

Eugene S. Gladkov

2012-11-01

Full Text Available Multicomponent reactions involving polyfunctional 4-amino-5-carboxamido-1,2,3-triazole and cyclic carbonyl-containing CH-acids were studied under conventional thermal heating, microwave and ultrasonic irradiation. The features of the reactions studied were discussed and the optimized procedures for the synthesis of final triazolopyrimidines were elaborated. In contrast to the similar MCRs of numerous other aminoazoles, a change of direction of the heterocyclizations in the case of 4-amino-5-carboxamido-1,2,3-triazole was not observed when microwave or thermal heating was substituted by ultrasonication at ambient temperature.

Seismic response of earth dams considering dynamic properties of unsaturated zone

Directory of Open Access Journals (Sweden)

Ariyan M.

2016-01-01

Full Text Available It is conventionally assumed in the analysis and design of earth dams that the soil located above the phreatic line, i.e. the uppermost seepage flow line, is completely dry. However, there is often an unsaturated flow of water through an unsaturated zone above this borderline and variation in moisture content in this zone results in variation of matric suction throughout this region. Variation of matric suction, in turn, results in variation of effective stresses in this zone. In this research, the seismic response of earth dams in terms of the displacement and acceleration at the crown of the dam as well as the stress distribution in the dam body is investigated. Taking into account the effect of unsaturated zone, a comparison is made to investigate the effect of conventional simplification in ignoring the dynamic characteristics of the unsaturated zone above the phreatic line and the more complicated analysis which includes the unsaturated zone. A function for the soil-water retention curve (SWRC was assigned to the soil in the unsaturated zone to determine the variation of matric suction in this zone and analyses were made using finite difference software (FLAC. Results are then compared to the conventional method for homogeneous dams. In these analyzes the soil shear modulus was assumed to vary with the mean effective stress both for saturated and unsaturated zones. Among various results, it was notable that the history of crest x-displacement, and acceleration show higher values in models accounting for the unsaturated region. It was attributed to the considerably lower values of damping ratio in the crest region in the unsaturated models.

Infiltration in Unsaturated Soils

DEFF Research Database (Denmark)

Ghotbi, Abdoul R.; Omidvar, M.; Barari, Amin

2011-01-01

An approximate analytical solution has been established for the well known Richards’ equation for unsaturated flow of transports in soils. Despite the importance of Richards’ equation in geotechnical and geoenvironmental applications, most solutions to the problem are generally based on numerical...

Aminocyclopentanols as sugar mimics. Synthesis from unsaturated bicyclic lactones by Overman rearrangement

DEFF Research Database (Denmark)

Bøjstrup, Marie; Fanefjord, Mette; Lundt, Inge

2007-01-01

Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta-D-N-acetylglucosaminid...

Characterization of unsaturated hydraulic conductivity at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Rockhold, M.L.; Fayler, M.J.; Gee, G.W.

1988-07-01

This report details some recent field measurements and compares predicted and measured values of hydraulic conductivities for three locations at the Hanford Site. Measurements from small (6-cm-dia) /open quotes/point/close quotes/ and large (2-m by 2-m) /open quotes/plot/close quotes/ areas utilized inflitration and drainage techniques to obtain in situ data for field-saturated and unsaturated hydraulic conductivity. The Guelph permeameter was used for point sampling, and the unsteady drainage-flux method was used on plots for field-saturated and unsaturated hydraulic conductivity measurements. Steady-state techniques were used to measure unsaturated hydraulic conductivities in small columns in the laboratory for one of the three soils tested to provide a comparison with data obtained from the field. Measured unsaturated hydraulic conductivities and those predicted from particle-size distribution and bulk density data agree within one-half to one and one-half orders of magnitude, depending on soil type. To use a particle-size distribution to estimate water retention characteristics and, subsequently, to predict unsaturated hydraulic conductivities, measurements of water-retention characteristics are necessary to determine a parameter value used in one of the models. No single method for measuring or calculating unsaturated hydraulic conductivities was found appropriate for all Hanford Site soils. Ideally, several methods should be used to take advantage of the strengths of each method, considering the data needs and resources available. 45 refs., 24 figs., 19 tabs.

Characterization of unsaturated hydraulic conductivity at the Hanford Site

International Nuclear Information System (INIS)

Rockhold, M.L.; Fayler, M.J.; Gee, G.W.

1988-07-01

This report details some recent field measurements and compares predicted and measured values of hydraulic conductivities for three locations at the Hanford Site. Measurements from small (6-cm-dia) /open quotes/point/close quotes/ and large (2-m by 2-m) /open quotes/plot/close quotes/ areas utilized inflitration and drainage techniques to obtain in situ data for field-saturated and unsaturated hydraulic conductivity. The Guelph permeameter was used for point sampling, and the unsteady drainage-flux method was used on plots for field-saturated and unsaturated hydraulic conductivity measurements. Steady-state techniques were used to measure unsaturated hydraulic conductivities in small columns in the laboratory for one of the three soils tested to provide a comparison with data obtained from the field. Measured unsaturated hydraulic conductivities and those predicted from particle-size distribution and bulk density data agree within one-half to one and one-half orders of magnitude, depending on soil type. To use a particle-size distribution to estimate water retention characteristics and, subsequently, to predict unsaturated hydraulic conductivities, measurements of water-retention characteristics are necessary to determine a parameter value used in one of the models. No single method for measuring or calculating unsaturated hydraulic conductivities was found appropriate for all Hanford Site soils. Ideally, several methods should be used to take advantage of the strengths of each method, considering the data needs and resources available. 45 refs., 24 figs., 19 tabs

Low pressure carbonylation of benzyl chloride = Die carbonylierung von benzylchlorid bei niedrigen drücken

NARCIS (Netherlands)

Luggenhorst, H.J.; Westerterp, K.R.

1986-01-01

For carbonylations, metal carbonyls, particularly cobalt and iron carbonyls, are often used as catalysts. These reactions take place under rather drastic reaction conditions, e.g. 200–300 °C and 60–100 MPa. In some patents it is stated that similar reactions using the same catalysts can also be

Analysis of rainfall infiltration law in unsaturated soil slope.

Science.gov (United States)

Zhang, Gui-rong; Qian, Ya-jun; Wang, Zhang-chun; Zhao, Bo

2014-01-01

In the study of unsaturated soil slope stability under rainfall infiltration, it is worth continuing to explore how much rainfall infiltrates into the slope in a rain process, and the amount of rainfall infiltrating into slope is the important factor influencing the stability. Therefore, rainfall infiltration capacity is an important issue of unsaturated seepage analysis for slope. On the basis of previous studies, rainfall infiltration law of unsaturated soil slope is analyzed. Considering the characteristics of slope and rainfall, the key factors affecting rainfall infiltration of slope, including hydraulic properties, water storage capacity (θs - θr), soil types, rainfall intensities, and antecedent and subsequent infiltration rates on unsaturated soil slope, are discussed by using theory analysis and numerical simulation technology. Based on critical factors changing, this paper presents three calculation models of rainfall infiltrability for unsaturated slope, including (1) infiltration model considering rainfall intensity; (2) effective rainfall model considering antecedent rainfall; (3) infiltration model considering comprehensive factors. Based on the technology of system response, the relationship of rainfall and infiltration is described, and the prototype of regression model of rainfall infiltration is given, in order to determine the amount of rain penetration during a rain process.

Beyond alkyl transfer: Synthesis of main group metal (Mg, Ca, Zn) silyl and tris(oxazolinyl)borato complexes and their stoichiometric and catalytic reactions with borane Lewis acids and carbonyls

Energy Technology Data Exchange (ETDEWEB)

Lampland, Nicole Lynn [Iowa State Univ., Ames, IA (United States)

2015-05-09

Recently, the fundamental knowledge of main group metal chemistry has grown. This progress is crucial for the further development of main group metal compounds in silicon chemistry and catalysis and for advancing their applications as green alternatives to many rare earth and transition metal compounds. This thesis focuses on reactivity beyond the welldocumented alkyl-transfer applications for main group metals, and it highlights examples of reactions with Lewis acids and the reduction of carbonyls.

Abstracts of the symposium on unsaturated flow and transport modeling

International Nuclear Information System (INIS)

1982-03-01

Abstract titles are: Recent developments in modeling variably saturated flow and transport; Unsaturated flow modeling as applied to field problems; Coupled heat and moisture transport in unsaturated soils; Influence of climatic parameters on movement of radionuclides in a multilayered saturated-unsaturated media; Modeling water and solute transport in soil containing roots; Simulation of consolidation in partially saturated soil materials; modeling of water and solute transport in unsaturated heterogeneous fields; Fluid dynamics and mass transfer in variably-saturated porous media; Solute transport through soils; One-dimensional analytical transport modeling; Convective transport of ideal tracers in unsaturated soils; Chemical transport in macropore-mesopore media under partially saturated conditions; Influence of the tension-saturated zone on contaminant migration in shallow water regimes; Influence of the spatial distribution of velocities in porous media on the form of solute transport; Stochastic vs deterministic models for solute movement in the field; and Stochastic analysis of flow and solute transport

Antiprotozoal compounds from Asparagus africanus

DEFF Research Database (Denmark)

Oketch-Rabah, H A; Dossaji, S F; Christensen, S B

1997-01-01

Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol.......Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl...

Protein carbonyl content: a novel biomarker for aging in HIV/AIDS patients

Directory of Open Access Journals (Sweden)

Vaishali Kolgiri

2017-01-01

Conclusions: Carbonyl content may has a role as a biomarker for detecting oxidative DNA damage induced ART toxicity and/or accelerated aging in HIV/AIDS patients. Larger studies are warranted to elucidate the role of carbonyl content as a biomarker for premature aging in HIV/AIDS patients.

Investigation on the Sediment of Lake Van, Turkey I - Oil Content

OpenAIRE

Güven, K.C.; Öztürk, B.; Ünlü, S.; Görgün, M.

2015-01-01

Abstract In this work hydrocarbon compounds of sediments were investigated in Lake Van. The samples were taken at 7 stations between 10-320 m depths.The highest oil level was found 4.69 µg/g at the station 2. The compounds identified by GC/MS were in aliphatic groups: 17 saturated, 4 cyclic, 5 unsaturated, 5 alcohol, 1 keton, 3 aldehyde and 4 fatty acids and in aromatic groups: 1 ring 1,2 rings 2 and 1 pregnane (5 beta). The compounds identified as: saturated compounds C5 - C43 are homo...

Inactivation of cellular enzymes by carbonyls and protein-bound glycation/glycoxidation products

DEFF Research Database (Denmark)

Morgan, Philip E; Dean, Roger T; Davies, Michael Jonathan

2002-01-01

products. In this study, we have examined the effect of glucose and carbonyl compounds (methylglyoxal, glyoxal, glycolaldehyde, and hydroxyacetone), and glycation products arising from reaction of these materials with model proteins, on the activity of three key cellular enzymes: glyceraldehyde-3-phosphate...... dehydrogenase (GAPDH), glutathione reductase, and lactate dehydrogenase, both in isolation and in cell lysates. In contrast to glucose (1M, both fresh and aged for 8 weeks), which had no effect, marked inhibition of all three enzymes was observed with methylglyoxal and glyoxal. GAPDH was also inhibited...... by glycolaldehyde and hydroxyacetone. Incubation of these enzymes with proteins that had been preglycated with methylglyoxal, but not glucose, also resulted in significant time- and concentration-dependent inhibition with both isolated enzymes and cell lysates. This inhibition was not metal ion, oxygen, superoxide...

[3H]-beta-endorphin binding in rat brain

International Nuclear Information System (INIS)

Houghten, R.A.; Johnson, N.; Pasternak, G.W.

1984-01-01

The binding of [ 3 H]-beta-endorphin to rat brain homogenates is complex. Although Scatchard analysis of saturation studies yields a straight line, detailed competition studies are multiphasic, suggesting that even at low concentrations of the compound, the 3 H-ligand is binding to more than one class of site. A portion of [ 3 H]-beta-endorphin binding is sensitive to low concentrations of morphine or D-Ala2-Leu5-enkephalin (less than 5 nM). The inhibition observed with each compound alone (5 nM) is the same as that seen with both together (each at 5 nM). Thus, the binding remaining in the presence of both morphine and the enkephalin does not correspond to either mu or delta sites. The portion of [ 3 H]-beta-endorphin binding that is inhibited under these conditions appears to be equally sensitive to both morphine and the enkephalin and may correspond to mu1 sites. Treating membrane homogenates with naloxonazine, a mu1 selective antagonist, lowers [ 3 H]-beta-endorphin binding to the same degree as morphine and D-Ala2-Leu5-enkephalin alone or together. This possible binding of [ 3 H]-beta-endorphin to mu1 sites is consistent with the role of mu1 sites in beta-endorphin analgesia and catalepsy in vivo

Coal and biomass-based chemicals via carbonylation, hydroformylation and homologation reactions

Energy Technology Data Exchange (ETDEWEB)

Sunavala, P.D.; Raghunath, B.

The paper emphasizes the importance of carbonylation, hydroformylation and homologation reactions in the manufacture of organic chemicals (such as acetic acid, acetic anhydride, cellulose acetate, vinyl acetate monomer, aliphatic amines, isocyanates, methanol, ethanol, n-butanol, ethylene glycol, acrylic acid, etc.) from coal and biomass feedstocks. Topics covered are: synthesis of acetic acid; manufacture of acetic anhydride; synthesis of vinyl acetate monomer by carbonylation; synthesis of aliphatic amines by hydroformylation; synthesis of organic diisocyanates; ethanol synthesis by homologation of methanol; synthesis of ethylene glycol via hydroformylation of formaldehyde; synthesis of n- butanol and n-butyraldehyde by propylene formylation; synthesis of acrylic acid; homologation reaction of carboxylic acid esters with ruthenium catalysts; and synthesis of phenyl isocyanate from nitrobenzene by reductive carbonylation. 26 refs.

Impact of HVAC filter on indoor air quality in terms of ozone removal and carbonyls generation

Science.gov (United States)

Lin, Chi-Chi; Chen, Hsuan-Yu

2014-06-01

This study aims at detecting ozone removal rates and corresponding carbonyls generated by ozone reaction with HVAC filters from various building, i.e., shopping mall, school, and office building. Studies were conducted in a small-scale environmental chamber. By examining dust properties including organic carbon proportion and specific surface area of dusts adsorbed on filters along with ozone removal rates and carbonyls generation rate, the relationship among dust properties, ozone removal rates, and carbonyls generation was identified. The results indicate a well-defined positive correlation between ozone removal efficiency and carbonyls generation on filters, as well as a positive correlation among the mass of organic carbon on filters, ozone removal efficiency and carbonyls generations.

Chemoselective Synthesis of Dithioacetals from Bio-aldehydes with Zeolites under Ambient and Solvent-free Conditions

DEFF Research Database (Denmark)

Li, Hu; Yang, Tingting; Riisager, Anders

2017-01-01

of commercial and modified zeolites are excellent catalysts for thioacetalization of different thiols with carbonyl compounds, including biomass-derived aldehydes, at room temperature under solvent-free conditions. A near quantitative yield of dithioacetal was obtained over H-beta(19) at room temperature......Dithioacetals are an important class of versatile compounds extensively applied in pharmaceuticals, separations, electrochemistry, and organic synthesis, but few heterogeneous catalytic systems are reported to be generally applicable for their synthesis from a wide range of substrates. A series...

Principles of Physical Modelling of Unsaturated Soils

OpenAIRE

CAICEDO, Bernardo; THOREL, Luc

2014-01-01

Centrifuge modelling has been widely used to simulate the performance of a variety of geotechnical works, most of them focusing on saturated clays or dry sands. On the other hand, the performance of some geotechnical works depends on the behaviour of shallow layers in the soil deposit where it is frequently unsaturated. Centrifuge modelling could be a powerful tool to study the performance of shallow geotechnical works. However all the experimental complexities related to unsaturated soils, w...

Quantifying Preferential Flow and Seasonal Storage in an Unsaturated Fracture-Facial Domain

Science.gov (United States)

Nimmo, J. R.; Malek-Mohammadi, S.

2012-12-01

Preferential flow through deep unsaturated zones of fractured rock is hydrologically important to a variety of contaminant transport and water-resource issues. The unsaturated zone of the English Chalk Aquifer provides an important opportunity for a case study of unsaturated preferential flow in isolation from other flow modes. The chalk matrix has low hydraulic conductivity and stays saturated, owing to its fine uniform pores and the wet climate of the region. Therefore the substantial fluxes observed in the unsaturated chalk must be within fractures and interact minimally with matrix material. Price et al. [2000] showed that irregularities on fracture surfaces provide a significant storage capacity in the chalk unsaturated zone, likely accounting for volumes of water required to explain unexpected dry-season water-table stability during substantial continuing streamflow observed by Lewis et al. [1993] In this presentation we discuss and quantify the dynamics of replenishment and drainage of this unsaturated zone fracture-face storage domain using a modification of the source-responsive model of Nimmo [2010]. This model explains the processes in terms of two interacting flow regimes: a film or rivulet preferential flow regime on rough fracture faces, active on an individual-storm timescale, and a regime of adsorptive and surface-tension influences, resembling traditional diffuse formulations of unsaturated flow, effective mainly on a seasonal timescale. The modified model identifies hydraulic parameters for an unsaturated fracture-facial domain lining the fractures. Besides helping to quantify the unsaturated zone storage described by Price et al., these results highlight the importance of research on the topic of unsaturated-flow relations within a near-fracture-surface domain. This model can also facilitate understanding of mechanisms for reinitiation of preferential flow after temporary cessation, which is important in multi-year preferential flow through deep

Supported Single-Site Ti(IV) on a Metal–Organic Framework for the Hydroboration of Carbonyl Compounds

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhiyuan [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Liu, Dong [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Camacho-Bunquin, Jeffrey [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Zhang, Guanghui [Department; Yang, Dali [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; López-Encarnación, Juan M. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Department; Xu, Yunjie [Department; Ferrandon, Magali S. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Niklas, Jens [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Poluektov, Oleg G. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Jellinek, Julius [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Lei, Aiwen [College; amp, Molecular Sciences, Institute of Advanced Studies, Wuhan University, Wuhan 430072, PR China; Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Bunel, Emilio E. [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Delferro, Massimiliano [Chemical; amp, Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States

2017-10-10

ABSTRACT: A stable and structurally well-defined titanium alkoxide catalyst supported on a metal-organic-framework (MOF) of UiO-67 topology (ANL1-Ti(OiPr)2) was synthesized and fully characterized by a variety of analytical and spectroscopic techniques, including BET, TGA, PXRD, XAS, DRIFT, SEM, and DFT computations. The Ti-functionalized MOF was demonstrated active for the catalytic hydroboration of a wide range of aldehydes and ketones with HBpin as the boron source. Compared to traditional homogeneous and supported hydroboration catalysts, ANL1-Ti(OiPr)2 is completely recyclable and reusable, making it a promising hydroboration catalyst alternative for green and sustainable chemical synthesis. DFT calculations suggest that the catalytic hydroboration proceeds via a (1) hydride transfer between the active Ti-hydride species and a carbonyl moiety (rate determining step), and (2) alkoxide transfer (intramolecular σ-bond metathesis) to generate the boronate ester product.

Carbonylation of 1-hexene in the presence of palladium-anion-exchange resin catalysts

Energy Technology Data Exchange (ETDEWEB)

Lapidus, A.L.; Pirozhkov, S.D.; Buiya, M.A.; Lunin, A.F.; Karapetyan, L.P.; Saldadze, K.M.

1986-06-20

Activated charcoal, silica gel, and zeolites containing palladium are active in the carbonylation of lower olefins by carbon monoxide. In the present work, they studied the carbonylation of 1-hexene in the presence of a series of palladium catalysts containing An-221, An-251, and AN-511 anion-exchange catalysts produced in the USSR as the supports. A catalyst obtained by the deposition of palladium(II) on weakly basic anion-exchange resins displays high efficiency in the carbonylation of 1-hexene with the formation of a nixture of enanthoic and 2-methylcaproic acids.

Oxidation of volatile organic compound vapours by potassium permanganate in a horizontal permeable reactive barrier under unsaturated conditions: experiments and modeling

NARCIS (Netherlands)

Ghareh Mahmoodlu, Mojtaba|info:eu-repo/dai/nl/357287746

2014-01-01

In this research we evaluated the potential of using solid potassium permanganate to create a horizontal permeable reactive barrier (HPRB) for oxidizing VOC vapours in the unsaturated zone. We have performed batch experiments, short column, and long column experiments, and have fully analyzed the

Chemical constituents from bark of Cenostigma macrophyllum: cholesterol occurrence; Constituintes quimicos das cascas do caule de Cenostigma macrophyllum: ocorrencia de colesterol

Energy Technology Data Exchange (ETDEWEB)

Silva, Hilris Rocha e; Silva, Carmem Cicera Maria da; Caland Neto, Laurentino Batista; Lopes, Jose Arimateia Dantas; Cito, Antonia Maria das Gracas Lopes; Chaves, Mariana H. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Dept. de Quimica]. E-mail: mariana@ufpi.br

2007-07-01

Phytochemical investigation of the bark of Cenostigma macrophyllum (Leguminosae-Caesapinioideae) resulted in the isolation and identification of valoneic acid dilactone, ellagic acid, lupeol, alkyl ferulate, four free sterols (cholesterol, campesterol, stigmasterol and sitosterol), a mixture of sitosteryl ester derivatives of fatty acids, sitosterol-3-O-beta-D-glucopyranoside, stigmasterol-3-O-beta-D-glucopyranoside and saturated and unsaturated fatty acids. The structures of the isolated compounds were identified by {sup 1}H and {sup 13}C NMR spectral analysis and comparison with literature data. The mixtures of 3-beta-hydroxysterols and fatty acids were analysed by GC/MS. (author)

Constituintes químicos das cascas do caule de Cenostigma macrophyllum: ocorrência de colesterol Chemical constituents from bark of Cenostigma macrophyllum: cholesterol occurrence

Directory of Open Access Journals (Sweden)

Hilris Rocha e Silva

2007-01-01

Full Text Available Phytochemical investigation of the bark of Cenostigma macrophyllum (Leguminosae-Caesapinioideae resulted in the isolation and identification of valoneic acid dilactone, ellagic acid, lupeol, alkyl ferulate, four free sterols (cholesterol, campesterol, stigmasterol and sitosterol, a mixture of sitosteryl ester derivatives of fatty acids, sitosterol-3-O-beta-D-glucopyranoside, stigmasterol-3-O-beta-D-glucopyranoside and saturated and unsaturated fatty acids. The structures of the isolated compounds were identified by ¹H and 13C NMR spectral analysis and comparison with literature data. The mixtures of 3-beta-hydroxysterols and fatty acids were analysed by GC/MS.

Chemical constituents from bark of Cenostigma macrophyllum: cholesterol occurrence

International Nuclear Information System (INIS)

Silva, Hilris Rocha e; Silva, Carmem Cicera Maria da; Caland Neto, Laurentino Batista; Lopes, Jose Arimateia Dantas; Cito, Antonia Maria das Gracas Lopes; Chaves, Mariana H.

2007-01-01

Phytochemical investigation of the bark of Cenostigma macrophyllum (Leguminosae-Caesapinioideae) resulted in the isolation and identification of valoneic acid dilactone, ellagic acid, lupeol, alkyl ferulate, four free sterols (cholesterol, campesterol, stigmasterol and sitosterol), a mixture of sitosteryl ester derivatives of fatty acids, sitosterol-3-O-beta-D-glucopyranoside, stigmasterol-3-O-beta-D-glucopyranoside and saturated and unsaturated fatty acids. The structures of the isolated compounds were identified by 1 H and 13 C NMR spectral analysis and comparison with literature data. The mixtures of 3-beta-hydroxysterols and fatty acids were analysed by GC/MS. (author)

Selectivity of beta-adrenergic stimulating and blocking agents.

Science.gov (United States)

Löfdahl, C G; Svedmyr, N

1984-01-01

Studies have been performed to answer two questions: whether there are subgroups of beta 2-receptors separating effects in bronchial and skeletal muscle and whether beta 1-receptors in asthmatic airways mediate bronchoconstriction. Asthmatic patients have been studied in randomised cross-over trials. Effects on FEV1, heart rate and skeletal muscle tremor have been monitored. In some experimental studies, two new compounds, D2343 and QH-25, have shown a selectivity for beta 2-receptors in bronchial muscle compared to skeletal muscle. Studies in asthmatics did not confirm this. Thus, the beta 2-receptors in the two organs appear to be identical. The clinical effect of beta 1-receptors in the the airways was studied by giving selective beta 1-receptor blocking agents. It was shown that pafenolol , a beta-blocker more beta 1-selective than metoprolol, had less effect on FEV1 than metoprolol given in equipotent beta 1-blocking doses. Beta 1-receptor stimulation with a new selective beta 1-stimulating agent, prenalterol, did not give bronchodilation in doses which gave a significant increase of heart rate. Thus, beta 1-receptors do not contribute to bronchodilation in asthmatic patients.

Virus movement in soil during saturated and unsaturated flow.

Science.gov (United States)

Lance, J C; Gerba, C P

1984-02-01

Virus movement in soil during saturated and unsaturated flow was compared by adding poliovirus to sewage water and applying the water at different rates to a 250-cm-long soil column equipped with ceramic samplers at different depths. Movement of viruses during unsaturated flow of sewage through soil columns was much less than during saturated flow. Viruses did not move below the 40-cm level when sewage water was applied at less than the maximum infiltration rate; virus penetration in columns flooded with sewage was at least 160 cm. Therefore, virus movement in soils irrigated with sewage should be less than in flooded groundwater recharge basins or in saturated soil columns. Management of land treatment systems to provide unsaturated flow through the soil should minimize the depth of virus penetration. Differences in virus movement during saturated and unsaturated flow must be considered in the development of any model used to simulate virus movement in soils.

Volatile flavor compounds in yogurt: a review.

Science.gov (United States)

Cheng, Hefa

2010-11-01

Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

Electrocatalytic studies of osmium-ruthenium carbonyl cluster compounds for their application as methanol-tolerant cathodes for oxygen reduction reaction and carbon monoxide-tolerant anodes for hydrogen oxidation reaction

Energy Technology Data Exchange (ETDEWEB)

Borja-Arco, E.; Uribe-Godinez, J.; Castellanos, R.H. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Escobedo (Mexico); Altamirano-Gutierrez, A.; Jimenez-Sandoval, O. [Centro de Investigacion y de Estudios Avanzados del Inst. Politecnico Nacional, Querataro (Mexico)

2006-07-01

This paper provided details of an electrokinetic study of novel electrocatalytic materials capable of performing both the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR). Osmium-ruthenium carbonyl cluster compounds (Os{sub x}Ru{sub 3}(CO){sub n}) were synthesized by chemical condensation in non-polar organic solvents at different boiling points and refluxing temperatures. Three different non-polar organic solvents were used: (1) n-nonane; o-xylene; and 1,2-dichlorobenzene. The electrocatalysts were characterized by Fourier Transform Infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). A rotating disk electrode technique was used to analyze the materials. Results of the analysis showed that the materials performed ORR in both the presence and absence of carbon monoxide (CO), and that electrocatalysts were not poisoned by the presence of CO. Cyclic voltamperometry for the disk electrodes showed that the electrochemical behaviour of the compounds in the acid electrolyte was similar in the presence or absence of methanol. The Tafel slope, exchange current density and the transfer coefficient were also investigated. The electrokinetic parameters for the ORR indicated that the materials with the highest electrocatalytic activity were synthesized in 1,2-dichlorobenzene. Electrocatalytic activity during HOR were prepared in n-nonane. It was concluded that the new materials are good candidates for use as both a cathode and an anode in proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). 7 refs., 2 tabs., 7 figs.

Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: a highly enantioselective pathway for accessing chiral flavanones.

Science.gov (United States)

He, Qijie; So, Chau Ming; Bian, Zhaoxiang; Hayashi, Tamio; Wang, Jun

2015-03-01

Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addition of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod*, the 1,4-addition of a variety of arylboronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbonyl[4-(2,3-dimethylphenylaminopent-3-en-2-onato-κ2N,O](triphenylphosphine-κPrhodium(I

Directory of Open Access Journals (Sweden)

Gertruida J. S. Venter

2009-11-01

Full Text Available In the title compound, [Rh(C13H16NO(C18H15P(CO], the coordination geometry of the RhI atom is square-planar, formed by the coordinating N and O atoms of the bidentate enaminoketonate ligand, one C atom from the carbonyl group and a P atom from triphenylphosphine. The complex displays a 0.591 (3:0.409 (3 ratio disorder of the phenyl unit of the monoanionic N,O-bidentate ligand. Intramolecular hydrogen bonding is observed between a C—H group of the triphenylphosphine unit and the O atom of the enaminoketonate ligand.

COMPARATIVE STUDY OF EFFICACY OF FERROUS SULPHATE AND CARBONYL IRON IN ANEMIA OF ANTENATAL WOMEN

Directory of Open Access Journals (Sweden)

Radhika

2015-03-01

Full Text Available Iron deficiency anemia is the most common and important public health problem all over the world in the risk group of antenatal women. Research is going on to improve the iron status of the pregnant women with different forms of iron available. In this regard, Carbonyl Iron is showing promising results in improving the red cell mass with better compliance. 120 antenatal women were recruited in this study. The study comprised of 6weeks for each patient. They were given Carbonyl Iron 100 mg/day and FeS04 100gm/day . Before and after treatment all the baseline and specific investigations were one. Results were tabulated, comparison and significance were tested by unpaired student ’s’ test and their 'p' value was calculated. Results were shown graphically also. Carbonyl Iron showed improvement in hemoglobin, PCV and better than ferrous Sulphate (P <0.001. Incidence of side effects were less with Carbonyl Iron than Ferrous Sulphate, better compliance was seen with Carbonyl Iron. In conclusion, the present study s howed that Carbonyl Iron had better efficacy and safety in the management of Iron deficiency anemia in antenatal women than ferrous Sulphate

Murrayafoline A attenuates the Wnt/{beta}-catenin pathway by promoting the degradation of intracellular {beta}-catenin proteins

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyuk; Gwak, Jungsug; Cho, Munju; Ryu, Min-Jung [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Lee, Jee-Hyun; Kim, Sang Kyum; Kim, Young Ho [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gye Won [Department of Pharmaceutical Engineering, Konyang University, Nonsan 320-711 (Korea, Republic of); Yun, Mi-Young [Department of Beauty Health Care, Daejeon University, Daejeon 305-764 (Korea, Republic of); Cuong, Nguyen Manh [Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Gyu-Yong, E-mail: gysong@cnu.ac.kr [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

2010-01-01

Molecular lesions in Wnt/{beta}-catenin signaling and subsequent up-regulation of {beta}-catenin response transcription (CRT) occur frequently during the development of colon cancer. To identify small molecules that suppress CRT, we screened natural compounds in a cell-based assay for detection of TOPFalsh reporter activity. Murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa, antagonized CRT that was stimulated by Wnt3a-conditioned medium (Wnt3a-CM) or LiCl, an inhibitor of glycogen synthase kinase-3{beta} (GSK-3{beta}), and promoted the degradation of intracellular {beta}-catenin without altering its N-terminal phosphorylation at the Ser33/37 residues, marking it for proteasomal degradation, or the expression of Siah-1, an E3 ubiquitin ligase. Murrayafoline A repressed the expression of cyclin D1 and c-myc, which is known {beta}-catenin/T cell factor (TCF)-dependent genes and thus inhibited the proliferation of various colon cancer cells. These findings indicate that murrayafoline A may be a potential chemotherapeutic agent for use in the treatment of colon cancer.

Conjugate addition of diethyl 1-fluoro-1-phenylsulfonylmethanephosphonate to alpha,beta-unsaturated compounds

Czech Academy of Sciences Publication Activity Database

Opekar, Stanislav; Pohl, Radek; Eigner, V.; Beier, Petr

2013-01-01

Roč. 78, č. 9 (2013), s. 4573-4579 ISSN 0022-3263 R&D Projects: GA ČR GP203/08/P310 Institutional support: RVO:61388963 Keywords : fluorine * phosphonate * conjugate addition Subject RIV: CC - Organic Chemistry Impact factor: 4.638, year: 2013

Infundibular neurons of the human hypothalamus simultaneously reactive with antisera against endorphins, ACTH, MSH and beta-LPH.

Science.gov (United States)

Bugnon, C; Bloch, B; Lenys, D; Fellmann, D

1979-06-27

In man, discrete neurons of the infundibular (arcuate) nucleus contain compounds that can be stained with anti-endorphin (alpha and beta), anti-ACTH, anti-MSH (alpha and beta) and anti-beta-LPH immune sera (I.S.). In the fetus, certain neurons stain with anti-beta-endorphin or anti((17--39)ACTH starting from the 11th week of fetal life. At the ultrastructural level, these neurons contain elementary granules that are immunoreactive with anti-beta-endorphin. In the adult, neurons immunoreactive with anti-beta-endorphin are found in the infundibular nucleus. Their axonal fibers terminate around blood vessels in the neurovascular zone and in the pituitary stalk, or establish contacts with non-immunoreactive perikarya of the infundibular nucleus. These neurons can be stained with anti(17--39)ACTH and anti-beta-endorphin I.S. The most reactive are also stained moderately with anti-alpha-MSH, anti-beta-MSH, anti-beta-LPH, anti-alpha-endorphin, or anti(1--24)ACTH I.S. These results indicate that, in man, compound(s) identical with or immunologically related to endorphins, beta-LPH, ACTH and MSH are secreted by certain hypothalamic neurons. These agents probably originate from a common precursor molecula similar to the so-called pro-opiocortin.

Impaired cardiac SIRT1 activity by carbonyl stress contributes to aging-related ischemic intolerance.

Directory of Open Access Journals (Sweden)

Chunhu Gu

Full Text Available Reactive aldehydes can initiate protein oxidative damage which may contribute to heart senescence. Sirtuin 1 (SIRT1 is considered to be a potential interventional target for I/R injury management in the elderly. We hypothesized that aldehyde mediated carbonyl stress increases susceptibility of aged hearts to ischemia/reperfusion (I/R injury, and elucidate the underlying mechanisms with a focus on SIRT1. Male C57BL/6 young (4-6 mo and aged (22-24 mo mice were subjected to myocardial I/R. Cardiac aldehyde dehydrogenase (ALDH2, SIRT1 activity and protein carbonyls were assessed. Our data revealed that aged heart exhibited increased endogenous aldehyde/carbonyl stress due to impaired ALDH2 activity concomitant with blunted SIRT1 activity (P<0.05. Exogenous toxic aldehydes (4-HNE exposure in isolated cardiomyocyte verified that aldehyde-induced carbonyl modification on SIRT1 impaired SIRT1 activity leading to worse hypoxia/reoxygenation (H/R injury, which could all be rescued by Alda-1 (ALDH2 activator (all P<0.05. However, SIRT1 inhibitor blocked the protective effect of Alda-1 on H/R cardiomyocyte. Interestingly, myocardial I/R leads to higher carbonylation but lower activity of SIRT1 in aged hearts than that seen in young hearts (P<0.05. The application of Alda-1 significantly reduced the carbonylation on SIRT1 and markedly improved the tolerance to in vivo I/R injury in aged hearts, but failed to protect Sirt1(+/- knockout mice against myocardial I/R injury. This was verified by Alda-1 treatment improved postischemic contractile function recovery in ex vivo perfused aged but not in Sirt1(+/- hearts. Thus, aldehyde/carbonyl stress is accelerated in aging heart. These results provide a new insight that impaired cardiac SIRT1 activity by carbonyl stress plays a critical role in the increased susceptibility of aged heart to I/R injury. ALDH2 activation can restore this aging-related myocardial ischemic intolerance.

Molecular Engineering with Organic Carbonyl Electrode Materials for Advanced Stationary and Redox Flow Rechargeable Batteries.

Science.gov (United States)

Zhao, Qing; Zhu, Zhiqiang; Chen, Jun

2017-12-01

Organic carbonyl electrode materials that have the advantages of high capacity, low cost and being environmentally friendly, are regarded as powerful candidates for next-generation stationary and redox flow rechargeable batteries (RFBs). However, low carbonyl utilization, poor electronic conductivity and undesired dissolution in electrolyte are urgent issues to be solved. Here, we summarize a molecular engineering approach for tuning the capacity, working potential, concentration of active species, kinetics, and stability of stationary and redox flow batteries, which well resolves the problems of organic carbonyl electrode materials. As an example, in stationary batteries, 9,10-anthraquinone (AQ) with two carbonyls delivers a capacity of 257 mAh g -1 (2.27 V vs Li + /Li), while increasing the number of carbonyls to four with the formation of 5,7,12,14-pentacenetetrone results in a higher capacity of 317 mAh g -1 (2.60 V vs Li + /Li). In RFBs, AQ, which is less soluble in aqueous electrolyte, reaches 1 M by grafting -SO 3 H with the formation of 9,10-anthraquinone-2,7-disulphonic acid, resulting in a power density exceeding 0.6 W cm -2 with long cycling life. Therefore, through regulating substituent groups, conjugated structures, Coulomb interactions, and the molecular weight, the electrochemical performance of carbonyl electrode materials can be rationally optimized. This review offers fundamental principles and insight into designing advanced carbonyl materials for the electrodes of next-generation rechargeable batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimisation and validation of a HS-SPME-GC-IT/MS method for analysis of carbonyl volatile compounds as biomarkers in human urine: Application in a pilot study to discriminate individuals with smoking habits.

Science.gov (United States)

Calejo, Isabel; Moreira, Nathalie; Araújo, Ana Margarida; Carvalho, Márcia; Bastos, Maria de Lourdes; de Pinho, Paula Guedes

2016-02-01

A new and simple analytical approach consisting of an automated headspace solid-phase microextraction (HS-SPME) sampler coupled to gas chromatography-ion trap/mass spectrometry detection (GC-IT/MS) with a prior derivatization step with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was developed to detect volatile carbonyl metabolites with low molecular weights in human urine. A central composite design (CCD) was used to optimise the PFBHA concentration and extraction conditions that affect the efficiency of the SPME procedure. With a sample volume of 1 mL, optimal conditions were achieved by adding 300 mg/L of PFBHA and allowing the sample to equilibrate for 6 min at 62°C and then extracting the samples for 51 min at the same temperature, using a divinylbenzene/polydimethylsiloxane (DVB/PDMS) fibre. The method allowed the simultaneous identification and quantification of 44 carbonyl compounds consisting of aldehydes, dialdehydes, heterocyclic aldehydes and ketones. The method was validated with regards to the linearity, inter- and intra-day precision and accuracy. The detection limits ranged from 0.009 to 0.942 ng/mL, except for 4-hydroxy-2-nonenal (15 ng/mL), and the quantification limits varied from 0.029 to 1.66 ng/mL, except for butanal (2.78 ng/mL), 2-butanone (2.67 ng/mL), 4-heptanone (3.14 ng/mL) and 4-hydroxy-2-nonenal (50.0 ng/mL). The method accuracy was satisfactory, with recoveries ranging from 90 to 107%. The proof of applicability of the methodology was performed in a pilot target analysis of urine samples obtained from 18 healthy smokers and 18 healthy non-smokers (control group). Chemometric supervised analysis was performed using the volatile patterns acquired for these samples and clearly showed the potential of the volatile carbonyl profiles to discriminate urine from smoker and non-smoker subjects. 5-Methyl-2-furfural (p<0.0001), 2-methylpropanal, nonanal and 2-methylbutanal (p<0.05) were identified as potentially useful

[Prevalence survey and molecular characterization of alpha and beta thalassemia in Liuzhou city of Guangxi].

Science.gov (United States)

Cai, Ren; Li, Liyan; Liang, Xin; Liu, Zhongying; Su, Liu; Li, Wenjun; Zhu, Qiangui; Mo, Qiuhua; Pan, Lizhen; Ouyang, Hong; Huang, Lihua; Xu, Xiangmin

2002-08-01

To investigate the gene frequencies and mutation patterns of alpha thalassemia (alpha-thal) and beta thalassemia (beta-thal) in Liuzhou city of Guangxi Zhuang Autonomous Region. Cluster sampling was used. A total of 1 028 of umbilical blood samples were collected for a prevalence study of alpha-thal and a total of 1 312 healthy young people when receiving pre-marriage consultation were recruited for a beta-thal prevalence survey. Individuals live in city or town area of Liuzhou. A complete blood count as well as hemoglobin electrophoresis analysis were done in all of samples for phenotyping of alpha and beta-thals. Those with Hb Bart's for alpha-thal indicator and those with both microcytosis (MCV /=4.0%) for beta-thal were further studied by DNA analysis. PCR-based methodologies were used to characterize the mutation contributions of alpha and beta-thals. All the subjects were tested for the state of carrying beta-thala alleles for evaluating the situation of the compound heterozygotes of alpha-thal with beta-thal. Of 1 028 random samples of umbilical blood screened, 112 of subjects were defined to be the gene carriers of alpha-thal. The alpha-thal carrier rate was as high as 11.19% including 3 compound heterozygotes. Five well-known types of alpha-thal alleles were detected with gene contributions of 37.4% (--(SEA) deletion), 31.3% (-alpha(3.7) deletion), 17.4% (-alpha(4.2) deletion), 12.1% (alpha(CS)alpha mutation), and 0.9% (alpha(QS)alpha mutation), successively. Of the 1 312 adult specimens studied, 89 with beta-thal including 14 of the compound higher Hb F subjects were detected. All of the 89 phenotypic beta-thal carriers had the mutations in the beta-globin gene, making the overall prevalence 6.78%. The commonly seen three mutations, beta CD41 - 42 (-CTTT) frameshift, beta CD17 (T-A) nonsense mutation and beta-28 (A-G) promoter variation were accounted for 90% of the beta-thal alleles in Liuzhou. Of these beta-thal subjects, 16 (accounting for 18%) were

Cocoa Phenolic Extract Protects Pancreatic Beta Cells against Oxidative Stress

Directory of Open Access Journals (Sweden)

Laura Bravo

2013-07-01

Full Text Available Diabetes mellitus is associated with reductions in glutathione, supporting the critical role of oxidative stress in its pathogenesis. Antioxidant food components such as flavonoids have a protective role against oxidative stress-induced degenerative and age-related diseases. Flavonoids constitute an important part of the human diet; they can be found in most plant foods, including green tea, grapes or cocoa and possess multiple biological activities. This study investigates the chemo-protective effect of a cocoa phenolic extract (CPE containing mainly flavonoids against oxidative stress induced by tert-butylhydroperoxide (t-BOOH on Ins-1E pancreatic beta cells. Cell viability and oxidative status were evaluated. Ins-1E cells treatment with 5–20 μg/mL CPE for 20 h evoked no cell damage and did not alter ROS production. Addition of 50 μM t-BOOH for 2 h increased ROS and carbonyl groups content and decreased reduced glutathione level. Pre-treatment of cells with CPE significantly prevented the t-BOOH-induced ROS and carbonyl groups and returned antioxidant defences to adequate levels. Thus, Ins-1E cells treated with CPE showed a remarkable recovery of cell viability damaged by t-BOOH, indicating that integrity of surviving machineries in the CPE-treated cells was notably protected against the oxidative insult.

Novel {beta}-Carboline Alkaloid from Peganum Harmala As Antibacterial Agent

Energy Technology Data Exchange (ETDEWEB)

Abdel Aziz, H G; Abdel Kader, S M; El-Sayed, M M; EL-Malt, E A; Shaker, E S [Chem. Dept., Fac. Agric., Minia Univ., Minia (Egypt)

2011-07-01

A novel {beta}-carboline alkaloid isolated from the aerial parts of Peganum harmala L. (Gen: Phyeophylaceae) have been characterized as l-thioformyl-8-{beta}-D-glucopyranoside-bis-2,3-dihydro-isopyridinopyrrol. It is one of {beta}-carboline alkaloids derivatives. The chemical structure was elucidated on the basis of elementary analysis and spectroscopic studies (UV, IR, {sup 1}H-NMR and MS). The isolated compound showed significant antibacterial activity against Streptococcus pyogenus.

Design, synthesis and bioactivity evaluation of tribactam beta lactamase inhibitors.

Science.gov (United States)

Copar, Anton; Prevec, Tadeja; Anzic, Borut; Mesar, Tomaz; Selic, Lovro; Vilar, Mateja; Solmajer, Tom

2002-03-25

Known carbapenem compounds with inhibitory effect towards beta-lactamase enzymes are formed from bicyclical beta lactam structural scaffolds. On the basis of results from theoretical computational methods and molecular modelling we have designed and developed a synthetic route towards novel, biologically active tricyclic derivatives of carbapenems.

Synthesis of rearranged unsaturated drimane derivatives

Directory of Open Access Journals (Sweden)

Miranda Domingos S. de

2001-01-01

Full Text Available A full account to the preparation and application of three appropriately substituted vinylcyclohexenes (2,2-dimethyl-3-vinylcyclohex-3-en-1-ol, 2,2-dimethyl-3-vinylcyclohex-3-en-1-one and 3,3-dimethyl-2-vinylcyclohexene in thermal Diels-Alder reactions with alpha,beta-unsaturated esters (methyl tiglate and methyl angelate is given. This approach delivered the racemic synthesis of ten octalin derivatives bearing a rearranged drimane skeleton (4 diastereomers of 1-methoxycarbonyl-6-hydroxy-1,2,5,5-tetramethyl-1,2,3,5,6,7, 8,8a-octahydronaphthalene; 1-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalene; 2-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene; 3 diastereomers of 1-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene and 2-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene . Central synthetic features included preparation of enoltriflates by Stang's protocol and the successful palladium-catalyzed cross-coupling reaction (Stille reaction of the triflate with the tri-n-butylvinylstannane. The octalins relative stereochemistry was unequivocally ascertained by spectroscopic methods and/or X-ray crystallography and these data now stand as useful tools to support the correct assignment of related natural products usually isolated in minute amounts.

Protein Carbonylation in Patients with Myelodysplastic Syndromes

Czech Academy of Sciences Publication Activity Database

Hlaváčková, A.; Štikarová, J.; Kotlín, R.; Chrastinová, L.; Šácha, Pavel; Májek, P.; Čermák, J.; Suttnar, J.; Dyr, J. E.

2015-01-01

Roč. 126, č. 23 (2015), s. 5232 ISSN 0006-4971. [Annual Meeting and Exposition of the American Society of Hematology /55./. 07.12.2013-10.12.2013, New Orleans] Institutional support: RVO:61388963 Keywords : protein carbonylation * myelodysplastic syndromes Subject RIV: CE - Biochemistry

MECHANICAL AND THERMAL PROPERTIES OF COMPOSITES FROM UNSATURATED POLYESTER FILLED WITH OIL PALM ASH

Directory of Open Access Journals (Sweden)

M.S. Ibrahim

2012-06-01

Full Text Available Oil palm ash (OPA is available in abundance, is renewable, can be obtained at no cost and shows good performance at high thermal conditions. Combinations of the unsaturated polyester with natural fillers have been reported to improve the mechanical and thermal properties of composites. Utilisation of oil palm ash as a filler in the manufacture of polymer composites can significantly reduce the requirement for other binders or matrixes of composite materials. This research uses oil palm ash as a filler to form composites through the investigation of the effect of different contents of filler on the properties of OPA-filled unsaturated polyester (UP/OPA composites. The effect of different volume fractions, i.e., 0, 10, 20 and 30 vol.% of oil palm ash introduced into 100, 90, 80 and 70 vol.% of an unsaturated polyester matrix on the composite mechanical properties, i.e., tensile and flexural, has been studied, together with thermal gravimetric analysis (TGA and differential scanning calorimetric (DSC. Specimens were prepared using compression moulding techniques based on the ASTM D790 and D5083 standards for flexural and tensile tests, respectively. The tensile and flexural mechanical properties of UP/OPA composites were improved in modulus by increasing the filler content. Thermal stability of the composites increased as the OPA filler content was increased, which was a logical consequence because of the high thermal stability of the silica compound of the OPA filler compared with that of the UP matrix. The results from the surface electron microscope (SEM analysis were the extension of mechanical and thermal tests.

The challenge of analyzing beta-blocker drugs in sludge and wastewater.

Science.gov (United States)

Scheurer, Marco; Ramil, Maria; Metcalfe, Chris D; Groh, Stefanie; Ternes, Thomas A

2010-01-01

In this study, different approaches were used to assess and overcome the severe effects of interference from the sample matrix from different types of sludges and wastewater on the analysis of nine beta-blockers and the beta sympathomimetic clenbuterol. The partitioning of the target compounds into sludge was investigated in wastewater treatment plants (WWTPs) in both Canada and Germany to evaluate whether this is an important mechanism for removal from sewage. Due to ion suppression in the electro spray interface, absolute recoveries were for certain compounds even lower than 20%. By using surrogate standards, acceptable relative recoveries of >75% were achieved for WWTP influents and effluents and for sludges. These matrix effects underline the need to use appropriate surrogate standards to aid in analyte quantitation. Using the developed methods, beta-blockers were detected at concentrations up to 2 microg/L in WWTP effluents, with metoprolol, sotalol, and atenolol present as the dominant compounds. Removal rates within WWTPs were highly inconsistent and ranged from 1-69%. Propranolol showed the greatest degree of partitioning into sludge with solid/water partition coefficients of one order of magnitude higher than those for all other compounds. However, even for propranolol, sorption did not contribute significantly to the overall elimination in WWTPs. It is likely that the removal of beta-blockers during waste water treatment can be attributed primarily to microbial biodegradation.

Waste migration in shallow burial sites under unsaturated flow conditions

International Nuclear Information System (INIS)

Eicholz, G.G.; Whang, J.

1987-01-01

Unsaturated conditions prevail in many shallow-land burial sites, both in arid and humid regions. Unless a burial site is allowed to flood and possibly overflow, a realistic assessment of any migration scenario must take into account the conditions of unsaturated flow. These are more difficult to observe and to model, but introduce significant changes into projected rates of waste leaching and waste migration. Column tests have been performed using soils from the Southeastern coastal plain to observe the effects of varying degrees of ''unsaturation'' on the movement of radioactive tracers. The moisture content in the columns was controlled by maintaining various levels of hydrostatic suction on soil columns whose hydrodynamic characteristics had been determined carefully. Tracer tests, employing Cs-137, I-131 and Ba-133 were used to determine migration profiles and to follow their movement down the column for different suction values. A calculational model has been developed for unsaturated flow and seems to match the observations fairly well. It is evident that a full description of migration processes must take into account the reduced migration rates under unsaturated conditions and the hysteresis effects associated with wetting-drying cycles

Analyzing Unsaturated Flow Patterns in Fractured Rock Using an Integrated Modeling Approach

International Nuclear Information System (INIS)

Y.S. Wu; G. Lu; K. Zhang; L. Pan; G.S. Bodvarsson

2006-01-01

Characterizing percolation patterns in unsaturated fractured rock has posed a greater challenge to modeling investigations than comparable saturated zone studies, because of the heterogeneous nature of unsaturated media and the great number of variables impacting unsaturated flow. This paper presents an integrated modeling methodology for quantitatively characterizing percolation patterns in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository site for storing high-level radioactive waste. The modeling approach integrates a wide variety of moisture, pneumatic, thermal, and isotopic geochemical field data into a comprehensive three-dimensional numerical model for modeling analyses. It takes into account the coupled processes of fluid and heat flow and chemical isotopic transport in Yucca Mountain's highly heterogeneous, unsaturated fractured tuffs. Modeling results are examined against different types of field-measured data and then used to evaluate different hydrogeological conceptualizations and their results of flow patterns in the unsaturated zone. In particular, this model provides a much clearer understanding of percolation patterns and flow behavior through the unsaturated zone, both crucial issues in assessing repository performance. The integrated approach for quantifying Yucca Mountain's flow system is demonstrated to provide a practical modeling tool for characterizing flow and transport processes in complex subsurface systems

(/sup 3/H)-beta-endorphin binding in rat brain

Energy Technology Data Exchange (ETDEWEB)

Houghten, R.A.; Johnson, N.; Pasternak, G.W.

1984-10-01

The binding of (/sup 3/H)-beta-endorphin to rat brain homogenates is complex. Although Scatchard analysis of saturation studies yields a straight line, detailed competition studies are multiphasic, suggesting that even at low concentrations of the compound, the /sup 3/H-ligand is binding to more than one class of site. A portion of (/sup 3/H)-beta-endorphin binding is sensitive to low concentrations of morphine or D-Ala2-Leu5-enkephalin (less than 5 nM). The inhibition observed with each compound alone (5 nM) is the same as that seen with both together (each at 5 nM). Thus, the binding remaining in the presence of both morphine and the enkephalin does not correspond to either mu or delta sites. The portion of (/sup 3/H)-beta-endorphin binding that is inhibited under these conditions appears to be equally sensitive to both morphine and the enkephalin and may correspond to mu1 sites. Treating membrane homogenates with naloxonazine, a mu1 selective antagonist, lowers (/sup 3/H)-beta-endorphin binding to the same degree as morphine and D-Ala2-Leu5-enkephalin alone or together. This possible binding of (/sup 3/H)-beta-endorphin to mu1 sites is consistent with the role of mu1 sites in beta-endorphin analgesia and catalepsy in vivo.

Adverse CNS-effects of beta-adrenoceptor blockers.

Science.gov (United States)

Gleiter, C H; Deckert, J

1996-11-01

In 1962 propranolol, the first beta adrenoceptor antagonist (beta blocker), was brought on to the market. There is now a host of different beta blockers available, and these compounds are among the most commonly prescribed groups of drugs. The efficacy of beta blockers has been proven predominantly for the treatment of cardiovascular diseases. Beta blockers are also used for certain types of CNS disorders, such as anxiety disorders, essential tremor and migraine. While low toxicity means that they have a favorable risk-benefit ratio, given the high intensity of use, it is essential to have a comprehensive knowledge of adverse events. Adverse events of beta blockers that can be related to the CNS are quite often neglected, even in textbooks of clinical pharmacology or review articles, and thus often misdiagnosed. The following article, therefore, after summarizing the use of beta blockers for CNS indications, critically reviews the literature on centrally mediated adverse events. General pharmacological features of beta blockers and their molecular basis of action will briefly be addressed to the extent that they are or may become relevant for central nervous pharmacotherapy and side-effects.

Proteomic identification of carbonylated proteins in F344 rat hippocampus after 1-bromopropane exposure

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhenlie [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan); Department of Toxicology, Guangdong Prevention and Treatment Center for Occupational Diseases, Guangzhou 510‐300 (China); Ichihara, Sahoko [Graduate School of Regional Innovation Studies, Mie University, Tsu 514‐8507 (Japan); Oikawa, Shinji [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Mie 514‐8507 (Japan); Chang, Jie; Zhang, Lingyi; Subramanian, Kaviarasan; Mohideen, Sahabudeen Sheik [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan); Ichihara, Gaku, E-mail: gak@med.nagoya-u.ac.jp [Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya 466‐8550 (Japan)

2012-08-15

1-Bromopropane (1-BP) is neurotoxic in both experimental animals and humans. Previous proteomic analysis of rat hippocampus implicated alteration of protein expression in oxidative stress, suggesting that oxidative stress plays a role in 1-BP-induced neurotoxicity. To understand this role at the protein level, we exposed male F344 rats to 1-BP at 0, 400, or 1000 ppm for 8 h/day for 1 week or 4 weeks by inhalation and quantitated changes in hippocampal protein carbonyl using a protein carbonyl assay, two-dimensional gel electrophoresis (2-DE), immunoblotting, and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-TOF/MS). Hippocampal reactive oxygen species and protein carbonyl were significantly increased, demonstrating 1-BP-associated induction of oxidative stress and protein damage. MALDI-TOF-TOF/MS identified 10 individual proteins with increased carbonyl modification (p < 0.05; fold-change ≥ 1.5). The identified proteins were involved in diverse biological processes including glycolysis, ATP production, tyrosine catabolism, GTP binding, guanine degradation, and neuronal metabolism of dopamine. Hippocampal triosephosphate isomerase (TPI) activity was significantly reduced and negatively correlated with TPI carbonylation (p < 0.001; r = 0.83). Advanced glycation end-product (AGE) levels were significantly elevated both in the hippocampus and plasma, and hippocampal AGEs correlated negatively with TPI activity (p < 0.001; r = 0.71). In conclusion, 1-BP-induced neurotoxicity in the rat hippocampus seems to involve oxidative damage of cellular proteins, decreased TPI activity, and elevated AGEs. -- Highlights: ► 1-BP increases hippocampal ROS levels and hippocampal and plasma protein carbonyls. ► 1-BP increases TPI carbonylation and decreases TPI activity in the hippocampus. ► 1-BP increases hippocampal and plasma AGE levels.

A framework for the behaviour of unsaturated expansive clays

International Nuclear Information System (INIS)

Gens, A.; Alonso, E.E.

1992-01-01

The paper presents a framework for describing the mechanical behaviour of unsaturated expansive clays. It is an extension of an existing formulation developed for unsaturated soils of low activity. The extended framework is based on the distinction within the material of a microstructural level where the basic swelling of the active minerals takes place, and a macrostructural level responsible for major structural rearrangements. Bu adopting simple assumptions concerning the coupling between the two levels, it is possible to reproduce major features of the behaviour of unsaturated expansive clays. Some selected qualitative comparisons between model predictions and experimental results reported in the literature are presented. Despite the simplified hypotheses made, a very encouraging agreement is obtained

A numerical solution to three-dimensional multiphase transport of volatile organic compounds in unsaturated soils -- with an application to the remedial method of in-situ volatilization

International Nuclear Information System (INIS)

Filley, T.; Tomasko, D.

1992-04-01

Part I of this paper presents the development and application of a numerical model for determining the fate and transport of volatile organic compounds (VOCS) in the unsaturated zone resulting from forced volatilization and gaseous advection-dispersion of organic vapor in a multipartitioned three-dimensional environment. The model allows for single-component transport in the gas and water phases. The hydrocarbon is assumed to be in specific retention and, therefore, immobile. Partitioning of the hydrocarbon between the oil, water, gas, and soil is developed as rate-limited functions that are incorporated into sink/source terms in the transport equations. The code for the model was developed specifically to investigate in-situ volatilization (ISV) remedial strategies, predict the extent of cleanup from information obtained at a limited number of measurement locations, and to help design ISV remedial systems. Application of the model is demonstrated for a hypothetical one-dimensional ISV system. Part II of this paper will present the analysis of an existing ISV system using the full three-dimensional capability of the model

Measurement and health risk assessment of PM2.5, flame retardants, carbonyls and black carbon in indoor and outdoor air in kindergartens in Hong Kong.

Science.gov (United States)

Deng, Wen-Jing; Zheng, Hai-Long; Tsui, Anita K Y; Chen, Xun-Wen

2016-11-01

Indoor air pollution is closely related to children's health. Polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) transmitted through indoor PM 2.5 and dust, along with carbonyl compounds and black carbon (BC) aerosol were analysed in five Hong Kong kindergartens. The results showed that 60% of the median PM 2.5 levels (1.3×10 1 to 2.9×10 1 μg/m 3 for indoor; 9.5 to 8.8×10 1 μg/m 3 for outdoor) in the five kindergartens were higher than the guidelines set by the World Health Organization (2.5×10 1 μg/m 3 ). Indoor PM 2.5 mass concentrations were correlated with outdoor PM 2.5 in four of the kindergartens. The PBDEs (0.10-0.64ng/m 3 in PM 2.5 ; 0.30-2.0×10 2 ng/g in dust) and DP (0.05-0.10ng/m 3 in PM 2.5 ; 1.3-8.7ng/g in dust) were detected in 100% of the PM 2.5 and dust samples. Fire retardant levels in the air were not correlated with the levels of dust in this study. The median BC concentrations varied by >7-fold from 8.8×10 2 ng/m -3 to 6.7×10 3 ng/m -3 and cooking events might have caused BC concentrations to rise both indoors and outdoors. The total concentrations of 16 carbonyls ranged from 4.7×10 1 μg/m 3 to 9.3×10 1 μg/m 3 indoors and from 1.9×10 1 μg/m 3 to 4.3×10 1 μg/m 3 outdoors, whilst formaldehyde was the most abundant air carbonyl. Indoor carbonyl concentrations were correlated with outdoor carbonyls in three kindergartens. The health risk assessment showed that hazard indexes (HIs) HIs of non-cancer risks from PBDEs and DPs were all lower than 0.08, whilst non-cancer HIs of carbonyl compounds ranged from 0.77 to 1.85 indoors and from 0.50 to 0.97 outdoors. The human intake of PBDEs and DP through inhalation of PM 2.5 accounted for 78% to 92% of the total intake. The cancer hazard quotients (HQs) of formaldehyde ranged from 4.5E-05 to 2.1E-04 indoors and from 1.9E-05 to 6.2E-05 outdoors. In general, the indoor air pollution in the five Hong Kong kindergartens might present adverse effects to children, although different

Effect of Unsaturated Flow on Delayed Response of Unconfined Aquifiers to Pumping

Science.gov (United States)

Tartakovsky, G.; Neuman, S. P.

2005-12-01

A new analytical solution is presented for the delayed response process characterizing flow to a partially penetrating well in an unconfined aquifer. The new solution generalizes that of Neuman [1972, 1974] by accounting for unsaturated flow above the water table. Axially symmetric three-dimensional flow in the unsaturated zone is described by a linearized version of Richards' equation in which hydraulic conductivity and water content vary exponentially with incremental capillary pressure head relative to its air entry value (defining the interface between the saturated and unsaturated zones). Unsaturated soil properties are characterized by an exponent κ having the dimension of inverse length and a dimensionless exponent κD = κb where b is initial saturated thickness. Our treatment of the unsaturated zone is similar to that of Kroszynski and Dagan [1975] who however have ignored internal (artesian) aquifer storage. It has been suggested by Boulton [1954, 1963, 1970] and Neuman [1972, 1974], and is confirmed by our solution, that internal storage is required to reproduce the early increase in drawdown characterizing delayed response to pumping in typical aquifers. According to our new solution such aquifers are characterized by relatively large κ_ D values, typically 10 or larger; in the limit as κD tends to infinity (the soil unsaturated water retention capacity becomes insignificant and/or aquifer thickness become large), unsaturated flow becomes unimportant and our solution reduces to that of Neuman. In typical cases corresponding to κD larger than or equal to 10, unsaturated flow is found to have little impact on early and late dimensionless time behaviors of drawdown measured wholly or in part at some distance below the water table; unsaturated flow causes drawdown to increase slightly at intermediate dimensionless time values that represent transition from an early artesian dominated to a late water-table dominated flow regime. The increase in drawdown

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

Science.gov (United States)

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

1980-01-01

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

Stochastic analysis of radionuclide migration in saturated-unsaturated soils

International Nuclear Information System (INIS)

Kawanishi, Moto

1988-01-01

In Japan, LLRW (low level radioactive wastes) generated from nuclear power plants shall be started to store concentrically in the Shimokita site from 1990, and those could be transformed into land disposal if the positive safety is confirmed. Therefore, it is hoped that the safety assessment method shall be successed for the land disposal of LLRW. In this study, a stochastic model to analyze the radionuclide migration in saturated-unsaturated soils was constructed. The principal results are summarized as follows. 1) We presented a generalized idea for the modeling of the radionuclide migration in saturated-unsaturated soils as an advective-dispersion phenomena followed by the decay of radionuclides and those adsorption/desorption in soils. 2) Based on the radionuclide migration model mentioned above, we developed a stochastic analysis model on radionuclide migration in saturated-unsaturated soils. 3) From the comparison between the simulated results and the exact solution on a few simple one-dimensional advective-dispersion problems of radionuclides, the good validity of this model was confirmed. 4) From the comparison between the simulated results by this model and the experimental results of radionuclide migration in a one-dimensional unsaturated soil column with rainfall, the good applicability was shown. 5) As the stochastic model such as this has several advantages that it is easily able to represent the image of physical phenomena and has basically no numerical dissipation, this model should be more applicable to the analysis of the complicated radionuclide migration in saturated-unsaturated soils. (author)

Effect of water on self-assembled tubules in {beta}-sitosterol + {gamma}-oryzanol-based organogels

Energy Technology Data Exchange (ETDEWEB)

Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen, E-mail: ruud-den.adel@unilever.co [Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, NL-3133 AT Vlaardingen (Netherlands)

2010-10-01

Mixtures of {beta}-sitosterol and {gamma}-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. {beta}-Sitosterol and {gamma}-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of {beta}-sitosterol + {gamma}-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of {beta}-sitosterol + {gamma}-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2{+-}0.1 nm, wall thickness 0.8{+-}0.2 nm).

Protein carbonyl content: a novel biomarker for aging in HIV/AIDS patients.

Science.gov (United States)

Kolgiri, Vaishali; Patil, Vinayak Wamanrao

The major complications of "treated" Human Immunodeficiency Virus (HIV) infection are cardiovascular disease, malignancy, renal disease, liver disease, bone disease, and perhaps neurological complications, which are phenomena of the normal aging process occurring at an earlier age in the HIV-infected population. The present study is aimed to explore protein carbonyl content as a biomarker for detecting oxidative DNA damage induced ART toxicity and/or accelerated aging in HIV/AIDS patients. To investigate the potential of carbonyl content as a biomarker for detecting oxidative Deoxyribonucleic acid (DNA) damage induced Antiretroviral Theraphy (ART) toxicity and/or accelerated aging in HIV/AIDS patients. In this case-control study a total 600 subjects were included. All subjects were randomly selected and grouped as HIV-negative (control group) (n=300), HIV-infected ART naive (n=100), HIV-infected on first line ART (n=100), and HIV-infected on second line ART (n=100). Seronegative control subjects were age- and sex-matched with the ART naive patients and the two other groups. Carbonyl protein was determined by the method described in Levine et al. DNA damage marker 8-OH-dG was determined using 8-hydroxy-2-deoxy Guanosine StressXpress ELA Kit by StressMarq Biosciences. Protein carbonyl content levels and oxidative DNA damage were significantly higher (paging in HIV/AIDS patients. Larger studies are warranted to elucidate the role of carbonyl content as a biomarker for premature aging in HIV/AIDS patients. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Metal-atom fluorescence from the quenching of metastable rare gases by metal carbonyls

International Nuclear Information System (INIS)

Hollingsworth, W.E.

1982-11-01

A flowing afterglow apparatus was used to study the metal fluorescence resulting from the quenching of metastable rare-gas states by metal carbonyls. The data from the quenching or argon, neon, and helium by iron and nickel carbonyl agreed well with a restricted degree of freedom model indicating a concerted bond-breaking dissociation

HS-SPME analysis of volatile organic compounds of coniferous needle litter

Science.gov (United States)

Isidorov, V. A.; Vinogorova, V. T.; Rafałowski, K.

The composition of volatile emission of Scots pine ( Pinus sylvestris) and spruce ( Picea exelsa) litter was studied by gas chromatography-mass spectrometry (GC-MS) and samples were collected by solid-phase microextraction (SPME) method. The list of identified compounds includes over 60 organic substances of different classes. It was established that volatile emission contain not only components of essential oils of pine and spruce needles but also a large number of organic compounds which are probably secondary metabolites of litter-decomposing fungi. They include lower carbonyl compounds and alcohols as well as products of terpene dehydration and oxidation. These data show that the processes of litter decomposition are an important source of reactive organic compounds under canopy of coniferous forests.

Unsaturated Fatty Acid Esters Metathesis Catalyzed by Silica Supported WMe5

KAUST Repository

Riache, Nassima; Callens, Emmanuel; Talbi, Karima; Basset, Jean-Marie

2015-01-01

Metathesis of unsaturated fatty acid esters (FAEs) by silica supported multifunctional W-based catalyst is disclosed. This transformation represents a novel route towards unsaturated di-esters. Especially, the self-metathesis of ethyl undecylenate

Potential for ground-water contamination from movement of wastewater through the unsaturated zone, upper Mojave River Basin, California

Science.gov (United States)

Umari, A.M.; Martin, P.M.; Schroeder, R.A.; Duell, L.F.; Fay, R.G.

1993-01-01

thick unsaturated zone and mixes with the ground water. The observed low nitrate concentrations also could be explained by a dilution by vertical mixing in the saturated zone and retention of the wastewater in the unsaturated zone. Results of a single-cell mixing model that allows nitrate from wastewater to be mixedinstantaneously with the underlying ground water suggest that measurable increases in nitrate concentration should be expected within 5 to 10 years after wastewater reaches the water table if the mixing depth is less than 100 feet. Although high fecal-coliform densities were measured in wastewater from septic tanks and seepage pits, removal of these enteric bacteria in the unsaturated zone is very effective, as was indicated by their absence in soil only a few feet from the seepage pits. In testing for organic priority pollutants in wastewater, 17 of 85 compounds were detected. Most compounds detected were present in low concentrations, except at one residence where the concentration of three compounds exceeded 100 micrograms per liter. These high concentrations may be a consequence of disposal practices unique to this residence. Extractable organic priority pollutants were not found in any soil cores taken adjacent to seepage pits and, therefore, are not of concern.

Reactions of ruthenium and osmium cluster carbonyls with heteroatom-substituted and functionalized alkynes

International Nuclear Information System (INIS)

Koridze, A.A.

2000-01-01

The results of studies of the reactions of ruthenium and osmium cluster carbonyls with metal (M = Re, Mn, Fe) alkynes, silylalkynes, propargyl alcohols and their derivatives, diynes, enynes, and ferrocenylacetylene are summarized. Intramolecular rearrangements in the cluster complexes including migrations of carbonyl, hydride, and hydrocarbon ligands and the metal core reorganization are considered [ru

Carbonyl(N-nitroso-N-oxido-1-naphtylamine-κ2O,O′(triphenylphosphine-κPrhodium(I acetone solvate

Directory of Open Access Journals (Sweden)

T. J. Muller

2009-12-01

Full Text Available The title compound, [Rh(C10H7N2O2(C18H15P(CO]·(CH32CO, is the second structural report of a metal complex formed with the O,O′-C10H7N2O2 (neocupferrate ligand. In the crystal structure, the metal centre is surrounded by one carbonyl ligand, one triphenylphosphine ligand and the bidentate neocupferrate ligand, forming a distorted square-planar RhCO2P coordination set which is best illustrated by the small O—Rh—O bite angle of 77.74 (10°. There are no classical hydrogen-bond interactions observed for this complex.

Unsaturated zone investigation at the radioactive waste storage facility site

Energy Technology Data Exchange (ETDEWEB)

Skuratovic, Zana; Mazeika, Jonas; Petrosius, Rimantas; Jakimaviciute-Maseliene, Vaidote [Nature Research Centre, Akademijos St. 2, LT-08412, Vilnius (Lithuania); Klizas, Petras; Mokrik, Robert [Vilnius University, M.K. Ciurlionio St. 21/27, LT-03101 Vilnius (Lithuania)

2014-07-01

Unsaturated zone is an important part of water circulation cycle and an integral part of many hydrological and hydrogeological factors and processes. The soils of unsaturated zone are regarded as the first natural barrier to a large extent able to limit the spread of contaminants. Nuclear waste disposal site (Maisiagala radioactive waste storage facility site) was analysed in terms of the moisture movement through the unsaturated zone. Extensive data sets of the hydraulic properties, water content and isotope composition have been collected and summarized. The main experimental and observational tasks included the collection of soil samples; determination of the physical properties and the hydraulic conductivity values of soil samples, moisture extraction from the soil sample for isotopic studies; observation of the groundwater dynamics at the Maisiagala piezometer; groundwater sampling for isotopic analysis ({sup 3}H, {sup 18}O/{sup 16}O, {sup 2}H/{sup 1}H ); and monthly precipitation isotopic analysis. Distribution features of globally widespread radionuclide tritium ({sup 3}H) and the water molecule tracer isotopes in precipitation, unsaturated zone soil moisture profiles and groundwater were determined. It was used the well-known unsaturated flow and transport model of HYDRUS-1D (Simunek et al., 2008). In this study, van Genuchten equations for the retention and conductivity estimations have been used. The retention characteristics and van Genuchten model parameters were estimated internally by HYDRUS based on the empirical equations involved in the program. Basic inputs of the tritium transport simulation are the tritium input function and meteorological variables (precipitation and potential evapotranspiration). In order to validate the representativeness of the hydraulic parameters, the model has been used to estimate the tritium distribution in the unsaturated zone, which properly represents the dynamics of the unsaturated zone. The uniformity of the daily

Isotope Investigations of Groundwater Movement in a Coarse Gravel Unsaturated Zone

Energy Technology Data Exchange (ETDEWEB)

Mali, N. [Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Kozar-Logar, J. [Jozef Stefan Institute, Ljubljana (Slovenia); Leis, A. [Institute of Water Resources Management, Hydrogeology and Geophysics, Joanneum Research Forschungsgesellschaft mbH, Graz (Austria)

2013-07-15

The unsaturated zone above an aquifer serves as a water reservoir which discharges water and possible pollution to the saturated zone. This paper presents the application of oxygen-18 and tritium isotope methods in the study of groundwater transport processes in the unsaturated zone of Selniska Dobrava coarse gravel aquifer. The Selniska Dobrava gravel aquifer is an important water resource for Maribor and its surroundings, therefore the determination of transport processes in the unsaturated zone is important regarding its protection. Groundwater flow characteristics were estimated using isotopes and based on experimental work in a lysimeter. Tritium investigation results were compared with the results of long term oxygen-18 isotope investigation. In this paper the analytical approach, results and interpretation of {delta}{sup 18}O and tritium measurements in the unsaturated zone are presented. (author)

Fate in digestion in vitro of several food components, including some toxic compounds coming from omega-3 and omega-6 lipids

NARCIS (Netherlands)

Goicoechea, E.; Brandon, E.F.A.; Blokland, M.H.; Guillén, M.D.

2011-01-01

In this study it was proved the formation of oxygenated alpha,beta-unsaturated aldehydes (OaßUAs) of 6, 7, 9 and 10 carbon atoms during the thermal treatment (190 °C with aeration) of a commercial vegetable oil rich in omega-3 and omega-6 acyl groups, which also contained small amounts of added

Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

Energy Technology Data Exchange (ETDEWEB)

Zhou Chang [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Fang Qingqing, E-mail: physfangqq@126.com [School of Physics and Material Science, Anhui University, Hefei 230036 (China) and Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China)

2012-05-15

The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0-20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<-5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<-5 dB and RL<-8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was -29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: Black-Right-Pointing-Pointer We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. Black-Right-Pointing-Pointer ZnO dielectric property increased absorption effect and absorption bandwidth. Black-Right-Pointing-Pointer Absorbing frequence of composites is expanding to low frequency direction. Black-Right-Pointing-Pointer The craft of high energy ball milling is easy to realize commerce production.

Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

International Nuclear Information System (INIS)

Zhou Chang; Fang Qingqing; Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong

2012-01-01

The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0–20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<−5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<−5 dB and RL<−8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was −29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: ► We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. ► ZnO dielectric property increased absorption effect and absorption bandwidth. ► Absorbing frequence of composites is expanding to low frequency direction. ► The craft of high energy ball milling is easy to realize commerce production.

Toxicology and metabolism of nickel compounds. Progress report, December 1, 1978-November 30, 1979. [Hamsters and rats

Energy Technology Data Exchange (ETDEWEB)

Sunderman, F.W. Jr.

1979-08-15

The toxicology and metabolism of nickel compounds were investigated in rats and hamsters. The new knowledge includes; demonstration that nickel carbonyl is teratogenic for hamsters; elucidation of physiological factors which influence ..cap alpha..Ni/sub 3/S/sub 2/-induced erythrocytosis in rats; development of a sensitive assay for heme oxygenase activity in renal microsomes for use in studies of renal effects of nickel compounds; demonstration that administration of Ni(CO)/sub 4/ to rats inhibits incorporation of /sup 3/H-thymidine into DNA during hepatic regeneration; demonstration that clones of Syrian hamster fetal cells which have been transformed by in vitro exposure to ..cap alpha..Ni/sub 3/S/sub 2/ consistently cause sarcomas following sc injection into nude mice; demonstration that nickel carbonyl-cyclopentadiene dimer induces rhabdomyosarcomas following im injection in rats; observation of differences in carcinogenic activities of several insoluble nickel compounds; discovery that intraocular injection of ..cap alpha..Ni/sub 3/S/sub 2/ induces amelanotic melanomas in rats; and refinement of analytical methods for nickel in biological materials.

Biotransformation of isoimperatorin and imperatorin by Glomerella cingulata and beta-secretase inhibitory activity.

Science.gov (United States)

Marumoto, Shinsuke; Miyazawa, Mitsuo

2010-01-01

Biotransformation studies conducted on the furanocoumarins isoimperatorin (1) and imperatorin (3) have revealed that 1 was metabolized by Glomerella cingulata to give the corresponding reduced acid, 6,7-furano-5-prenyloxy hydrocoumaric acid (2), and 3 was transformed by G. cingulata to give the dealkylated metabolite, xanthotoxol (4) in high yields (83% and 81%), respectively. The structures of the new compound 2 have been established on the basis of spectral data. The metabolites 2 and 4 were tested for the beta-secretase (BACE1) inhibitory activity in vitro, and metabolite 2 slightly inhibited the beta-secretase activity with an IC(50) value of 185.6+/-6.8 microM. The metabolite 4 was less potent activity than compounds 1-3. In addition, methyl ester (2Me), methyl ether (2a) and methyl ester and ether (2aMe) of 2 were synthesized, and investigated for the ability to inhibit beta-secretase. Compound 2aMe exhibited the best beta-secretase inhibitory activity at the IC(50) value 16.2+/-1.2 microM and found to be the 2aMe showed competitive mode of inhibition against beta-secretase with K(i) value 11.3+/-2.8 microM. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Transport of citrate-coated silver nanoparticles in unsaturated sand

Science.gov (United States)

Kumahor, Samuel; Hron, Pavel; Metreveli, George; Schaumann, Gabriele; Vogel, Hans-Jörg

2015-04-01

Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Unlike for saturated transport, studies on unsaturated transport as typical for soil are currently scarce. We investigated the mobility of citrate-coated Ag NPs in unsaturated sand (grain diameter: 0.1-0.3 mm). For three flux rates and a given pore-water ionic strength (1 mM KNO3), the citrate-coated Ag NPs were less mobile at pH = 5 compared to pH = 9. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggests unfavorable deposition conditions at both, the air-water interface and solid-water interface. Breakthrough curves measured under quasi-steady state unsaturated flow showed retardation of the citrate-coated Ag NPs compared to inert solute (KBr). After flushing with nanoparticle-free 1 mM KNO3 solution (pH-adjusted), retention was much lower in deeper depths compared to the surface where the particles entered the flow field. The results show a non-linear dependence of nanoparticle (NP) mobility on flux rate and water content. Especially the observed retardation similar to equilibrium sorption is in contrast to observations under saturated flow conditions. A convection-dispersion and reaction model that combines a reversible equilibrium process and a non-equilibrium interaction process reproduced the measured breakthrough curves reasonably well. From comparison between saturated and unsaturated experiments we conclude that the air-water interface is responsible for the reversible equilibrium process while the water-solid interface accounts for irreversible soption.

Atom-type-based AI topological descriptors: application in structure-boiling point correlations of oxo organic compounds.

Science.gov (United States)

Ren, Biye

2003-01-01

Structure-boiling point relationships are studied for a series of oxo organic compounds by means of multiple linear regression (MLR) analysis. Excellent MLR models based on the recently introduced Xu index and the atom-type-based AI indices are obtained for the two subsets containing respectively 77 ethers and 107 carbonyl compounds and a combined set of 184 oxo compounds. The best models are tested using the leave-one-out cross-validation and an external test set, respectively. The MLR model produces a correlation coefficient of r = 0.9977 and a standard error of s = 3.99 degrees C for the training set of 184 compounds, and r(cv) = 0.9974 and s(cv) = 4.16 degrees C for the cross-validation set, and r(pred) = 0.9949 and s(pred) = 4.38 degrees C for the prediction set of 21 compounds. For the two subsets containing respectively 77 ethers and 107 carbonyl compounds, the quality of the models is further improved. The standard errors are reduced to 3.30 and 3.02 degrees C, respectively. Furthermore, the results obtained from this study indicate that the boiling points of the studied oxo compound dominantly depend on molecular size and also depend on individual atom types, especially oxygen heteroatoms in molecules due to strong polar interactions between molecules. These excellent structure-boiling point models not only provide profound insights into the role of structural features in a molecule but also illustrate the usefulness of these indices in QSPR/QSAR modeling of complex compounds.

Profile of blood glucose and ultrastucture of beta cells pancreatic islet in alloxan compound induced rats

Directory of Open Access Journals (Sweden)

I Nyoman Suarsana

2010-06-01

Full Text Available Diabetes is marked by elevated levels of blood glucose, and progressive changes of the structure of pancreatic islet histopathology. The objective of this research was to analyse the glucose level and histophatological feature in pancreatic islet in alloxan compound induced rats. A total of ten male Spraque Dawley rats of 2 months old were used in this study. The rats were divided into two groups: (1 negative control group (K-, and (2 positif induced alloxan group (diabetic group =DM. The rats were induced by a single dose intraperitonial injection of alloxan compound 120 mg/kg of body weight. The treatment was conducted for 28 days. Blood glucose levels of rats were analysed at 0, 4, 7, 14, 21, and 28 days following treatment. At the end of the experiment, rats were sacrificed by cervical dislocation. Pancreas was collected for analysis of histopathological study by Immunohistochemical technique, and ultrastructural study using transmission electron microscope (TEM. The result showed that Langerhans islet of diabetic rat (rat of DM group showed a marked reduction of size, number of Langerhans islet of diabetic rat decrease, and characterized by hyperglycemic condition. By using TEM, beta cells of DM group showed the rupture of mitochondrial membrane, the lost of cisternal structure of inner membrane of mitocondria, reduction of insulin secretory granules, linkage between cells acinar with free Langerhans islet, and the caryopicnotic of nucleus.

Extraterrestrial Organic Compounds in Meteorites

Science.gov (United States)

Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

2003-01-01

Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

Instrument for Airborne Measurement of Carbonyl Sulfide, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Southwest Sciences proposes to develop small, low power instrumentation for the real-time direct measurement of carbonyl sulfide (OCS) in the atmosphere, especially...

Thermodynamics and structure of inclusion compounds of tauro- and glyco-conjugated bile salts and beta-cyclodextrin

DEFF Research Database (Denmark)

Holm, Rene; Shi, Wei; Andersen Hartvig, Rune

2009-01-01

The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry, and the str......The interaction between natural beta-cyclodextrin and bile salts common in rat, dog and man, taurocholate, tauro-beta-muricholate, taurodeoxycholate, taurochenodeoxycholate, glycocholate, glycodeoxycholate and glycochenodeoxycholate, was studied using isothermal titration calorimetry......, and the structural differences in the interaction were investigated by H-1-ROESY NMR and molecular modeling. The beta-cyclodextrin was selected based upon its frequent use in preformulation and drug formulation as oral excipients for the solubilization of drug substances with low aqueous solubility. All...

Instrument for Airborne Measurement of Carbonyl Sulfide, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In this Phase II SBIR program, Southwest Sciences will continue the development of small, low power instrumentation for real-time direct measurement of carbonyl...

Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids

OpenAIRE

Sedlačík, M.; Pavlínek, V.; Lehocký, M.; Mráček, A.; Grulich, O.; Švrčinová, P. (Petra); Filip, P. (Petr); Vesel, A.

2011-01-01

The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was in...

Enhanced antioxidation and microwave absorbing properties of SiO2-coated flaky carbonyl iron particles

Science.gov (United States)

Zhou, Yingying; Xie, Hui; Zhou, Wancheng; Ren, Zhaowen

2018-01-01

SiO2 was successfully coated on the surface of flaky carbonyl iron particles using a chemical bath deposition method in the presence of 3-aminopropyl triethoxysilane (APTES). The morphologies, composition, valence states of elements, as well as antioxidation and electromagnetic properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and microwave network analyzer. TG curve shows the obvious weight gain of carbonyl iron was deferred to 360 °C after SiO2-coated, which can be ascribed to the exits of SiO2 overlayer. Compared with the raw carbonyl iron, SiO2-coated sample shows good wave absorption performance due to its impedance matching. The electromagnetic properties of raw and SiO2-coated carbonyl iron particles were characterized in X band before and after heat treatment at 250 °C for 10 h. It was established that SiO2-coated carbonyl iron demonstrate good thermal stability, indicating SiO2-coating is useful in the usage of microwave absorbers operating at temperature up to 250 °C.

Anchoring selenido-carbonyl ruthenium clusters to functionalized silica xerogels