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Sample records for carbonyl derivatives relevance

  1. Human TTR conformation altered by rhenium tris-carbonyl derivatives.

    PubMed

    Ciccone, Lidia; Policar, Clotilde; Stura, Enrico A; Shepard, William

    2016-09-01

    Transthyretin (TTR) is a 54 kDa homotetrameric serum protein that transports thyroxine (T4) and retinol. TTR is potentially amyloidogenic due to homotetramer dissociation into monomeric intermediates that self-assemble as amyloid deposits and insoluble fibrils. Most crystallographic structures, including those of amyloidogenic variants show the same tetramer without major variations in the monomer-monomer interface nor in the volume of the interdimeric cavity. Soaking TTR crystals in a solution containing rhenium tris-carbonyl derivatives yields a TTR conformer never observed before. Only one of the two monomers of the crystallographic dimer is significantly altered, and the inner part of the T4 binding cavity is expanded at one end and shrunk at the other. The result redefines the mechanism of allosteric communication between the two sites, suggesting that negative cooperativity is a function of dimer asymmetry, which can be induced through internal or external binding. An aspect that remains unexplained is why the conformational changes are ubiquitous throughout the crystal although the heavy metal content of the derivatized crystals is relatively low. The conformational changes observed, which include Leu(82), may represent a form of TTR better at scavenging β-Amyloid. At a resolution of 1.69Å, with excellent refinement statistics and well defined electron density for all parts of the structure, it is possible to envisage answering important questions that range from protein cooperative behavior to heavy atom induced protein conformational modifications that can result in crystallographic non-isomorphism. PMID:27402536

  2. Lipid Peroxide-Derived Short-Chain Carbonyls Mediate Hydrogen Peroxide-Induced and Salt-Induced Programmed Cell Death in Plants.

    PubMed

    Biswas, Md Sanaullah; Mano, Jun'ichi

    2015-07-01

    Lipid peroxide-derived toxic carbonyl compounds (oxylipin carbonyls), produced downstream of reactive oxygen species (ROS), were recently revealed to mediate abiotic stress-induced damage of plants. Here, we investigated how oxylipin carbonyls cause cell death. When tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells were exposed to hydrogen peroxide, several species of short-chain oxylipin carbonyls [i.e. 4-hydroxy-(E)-2-nonenal and acrolein] accumulated and the cells underwent programmed cell death (PCD), as judged based on DNA fragmentation, an increase in terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nuclei, and cytoplasm retraction. These oxylipin carbonyls caused PCD in BY-2 cells and roots of tobacco and Arabidopsis (Arabidopsis thaliana). To test the possibility that oxylipin carbonyls mediate an oxidative signal to cause PCD, we performed pharmacological and genetic experiments. Carnosine and hydralazine, having distinct chemistry for scavenging carbonyls, significantly suppressed the increase in oxylipin carbonyls and blocked PCD in BY-2 cells and Arabidopsis roots, but they did not affect the levels of ROS and lipid peroxides. A transgenic tobacco line that overproduces 2-alkenal reductase, an Arabidopsis enzyme to detoxify α,β-unsaturated carbonyls, suffered less PCD in root epidermis after hydrogen peroxide or salt treatment than did the wild type, whereas the ROS level increases due to the stress treatments were not different between the lines. From these results, we conclude that oxylipin carbonyls are involved in the PCD process in oxidatively stressed cells. Our comparison of the ability of distinct carbonyls to induce PCD in BY-2 cells revealed that acrolein and 4-hydroxy-(E)-2-nonenal are the most potent carbonyls. The physiological relevance and possible mechanisms of the carbonyl-induced PCD are discussed. PMID:26025050

  3. Lipid Peroxide-Derived Short-Chain Carbonyls Mediate Hydrogen Peroxide-Induced and Salt-Induced Programmed Cell Death in Plants1[OPEN

    PubMed Central

    Biswas, Md. Sanaullah; Mano, Jun’ichi

    2015-01-01

    Lipid peroxide-derived toxic carbonyl compounds (oxylipin carbonyls), produced downstream of reactive oxygen species (ROS), were recently revealed to mediate abiotic stress-induced damage of plants. Here, we investigated how oxylipin carbonyls cause cell death. When tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells were exposed to hydrogen peroxide, several species of short-chain oxylipin carbonyls [i.e. 4-hydroxy-(E)-2-nonenal and acrolein] accumulated and the cells underwent programmed cell death (PCD), as judged based on DNA fragmentation, an increase in terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nuclei, and cytoplasm retraction. These oxylipin carbonyls caused PCD in BY-2 cells and roots of tobacco and Arabidopsis (Arabidopsis thaliana). To test the possibility that oxylipin carbonyls mediate an oxidative signal to cause PCD, we performed pharmacological and genetic experiments. Carnosine and hydralazine, having distinct chemistry for scavenging carbonyls, significantly suppressed the increase in oxylipin carbonyls and blocked PCD in BY-2 cells and Arabidopsis roots, but they did not affect the levels of ROS and lipid peroxides. A transgenic tobacco line that overproduces 2-alkenal reductase, an Arabidopsis enzyme to detoxify α,β-unsaturated carbonyls, suffered less PCD in root epidermis after hydrogen peroxide or salt treatment than did the wild type, whereas the ROS level increases due to the stress treatments were not different between the lines. From these results, we conclude that oxylipin carbonyls are involved in the PCD process in oxidatively stressed cells. Our comparison of the ability of distinct carbonyls to induce PCD in BY-2 cells revealed that acrolein and 4-hydroxy-(E)-2-nonenal are the most potent carbonyls. The physiological relevance and possible mechanisms of the carbonyl-induced PCD are discussed. PMID:26025050

  4. Synthesis of 2-Cyclopentenone Derivatives via Palladium-Catalyzed Intramolecular Carbonyl α-Alkenylation.

    PubMed

    Chen, Panpan; Meng, Yinggao; Wang, Han; Han, Feipeng; Wang, Yulong; Song, Chuanjun; Chang, Junbiao

    2016-08-01

    2-Cyclopentenone derivatives have been efficiently synthesized from 5-bromo-5-hexen-2-ones via palladium-catalyzed intramolecular carbonyl α-alkenylation followed by double-bond migration under mild reaction conditions. PMID:27463262

  5. Exploring the biology of lipid peroxidation-derived protein carbonylation.

    PubMed

    Fritz, Kristofer S; Petersen, Dennis R

    2011-09-19

    The sustained overproduction of reactive oxygen and nitrogen species results in an imbalance of cellular prooxidant-antioxidant systems and is implicated in numerous disease states, including alcoholic liver disease, cancer, neurological disorders, inflammation, and cardiovascular disease. The accumulation of reactive aldehydes resulting from sustained oxidative stress and lipid peroxidation is an underlying factor in the development of these pathologies. Determining the biochemical factors that elicit cellular responses resulting from protein carbonylation remains a key element to developing therapeutic approaches and ameliorating disease pathologies. This review details our current understanding of the generation of reactive aldehydes via lipid peroxidation resulting in protein carbonylation, focusing on pathophysiologic factors associated with 4-hydroxynonenal-protein modification. Additionally, an overview of in vitro and in vivo model systems used to study the physiologic impact of protein carbonylation is presented. Finally, an update of the methods commonly used in characterizing protein modification by reactive aldehydes provides an overview of isolation techniques, mass spectrometry, and computational biology. It is apparent that research in this area employing state-of-the-art proteomics, mass spectrometry, and computational biology is rapidly evolving, yielding foundational knowledge concerning the molecular mechanisms of protein carbonylation and its relation to a spectrum of diseases associated with oxidative stress. PMID:21812433

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Synthesis, spectroscopic characterizations, crystal structures and DFT studies of nalidixic acid carbonyl hydrazones derivatives

    NASA Astrophysics Data System (ADS)

    Bergamini, F. R. G.; Ribeiro, M. A.; Lancellotti, M.; Machado, D.; Miranda, P. C. M. L.; Cuin, A.; Formiga, A. L. B.; Corbi, P. P.

    2016-09-01

    This article describes the synthesis and characterization of the 1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazide (hzd) and six carbonyl hydrazones derivatives of the nalidixic with 1H-pyrrol-2-ylmethylidene (hpyrr), 1H-imidazol-2-ylmethylidene (h2imi), pyridin-2-ylmethylidene (h2py), pyridin-3-ylmethylidene (h3py), pyridin-4-ylmethylidene(h4py) and (2-hydroxyphenyl)methylidene (hsali). The carbonyl hydrazones were characterized by elemental and ESI-QTOF-MS analyses, IR and detailed NMR spectroscopic measurements. The 2D NMR experiments allowed the unambiguous assignment of the hydrogen, carbon and nitrogen atoms, which have not been reported for nalidixic acid carbonyl hydrazone derivatives so far. Crystal structures of hzd and the new carbonyl hydrazones h2imi, hpyrr and h3py were determined by X-ray diffraction studies. Although the synthesis of hzd was reported decades ago, the hzd crystal structure have not been reported yet. Geometric optimizations of all the characterized structures were performed with the aid of DFT studies. Despite the fact that the hydrazones with 2-pyridine carboxylic acid (h2py) and salicyl aldehyde (hsali) were already reported by literature, a detailed spectroscopic study followed by DFT studies are also reported for such compounds in this manuscript. Antimicrobial studies of the compounds are also presented.

  8. Amino acid decarboxylations produced by lipid-derived reactive carbonyls in amino acid mixtures.

    PubMed

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

    2016-10-15

    The formation of 2-phenylethylamine and phenylacetaldehyde in mixtures of phenylalanine, a lipid oxidation product, and a second amino acid was studied to determine the role of the second amino acid in the degradation of phenylalanine produced by lipid-derived reactive carbonyls. The presence of the second amino acid usually increased the formation of the amine and reduced the formation of the Strecker aldehyde. The reasons for this behaviour seem to be related to the α-amino group and the other functional groups (mainly amino or similar groups) present in the side-chain of the amino acid. These groups are suggested to modify the lipid-derived reactive carbonyl but not the reaction mechanism because the Ea of formation of both 2-phenylethylamine and phenylacetaldehyde remained unchanged in all studied systems. All these results suggest that the amine/aldehyde ratio obtained by amino acid degradation can be modified by adding free amino acids during food formulation. PMID:27173560

  9. Carbonylative Suzuki Couplings of Aryl Bromides with Boronic Acid Derivatives under Base-Free Conditions

    PubMed Central

    2015-01-01

    The carbonylative Suzuki–Miyaura reaction between aryl bromides and arylboronic acid equivalents is herein reported, using base-free conditions and a limited excess of carbon monoxide generated ex situ from stable CO-precursors. Under these conditions, unsymmetrical biaryl ketones were obtained in modest to excellent yields. This method was adapted to the synthesis of the triglyceride and cholesterol regulator drug, fenofibrate, and its 13C-labeled derivative in good yields from the appropriate CO-precursor. PMID:24635142

  10. Diverse roles of hydrogen in rhenium carbonyl chemistry: hydrides, dihydrogen complexes, and a formyl derivative.

    PubMed

    Li, Nan; Xie, Yaoming; King, R Bruce; Schaefer, Henry F

    2010-11-01

    Rhenium carbonyl hydride chemistry dates back to the 1959 synthesis of HRe(CO)₅ by Hieber and Braun. The binuclear H₂Re₂(CO)₈ was subsequently synthesized as a stable compound with a central Re₂(μ-H)₂ unit analogous to the B₂(μ-H)₂ unit in diborane. The complete series of HRe(CO)(n) (n = 5, 4, 3) and H₂Re₂(CO)(n) (n = 9, 8, 7, 6) derivatives have now been investigated by density functional theory. In contrast to the corresponding manganese derivatives, all of the triplet rhenium structures are found to lie at relatively high energies compared with the corresponding singlet structures consistent with the higher ligand field splitting of rhenium relative to manganese. The lowest energy HRe(CO)₅ structure is the expected octahedral structure. Low-energy structures for HRe(CO)(n) (n = 4, 3) are singlet structures derived from the octahedral HRe(CO)₅ structure by removal of one or two carbonyl groups. For H₂Re₂(CO)₉ a structure HRe₂(CO)₉(μ-H), with one terminal and one bridging hydrogen atom, lies within 3 kcal/mol of the structure Re₂(CO)₉(η²-H₂), similar to that of Re₂(CO)₁₀. For H₂Re₂(CO)(n) (n = 8, 7, 6) the only low-energy structures are doubly bridged singlet Re₂(μ-H)₂(CO)(n) structures. Higher energy dihydrogen complex structures are also found. PMID:20942474

  11. MOLECULAR MECHANISM OF GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE (GAPDH) INACTIVATION BY α,β-UNSATURATED CARBONYL DERIVATIVES

    PubMed Central

    Martyniuk, Christopher J.; Fang, Bin; Koomen, John M.; Gavin, Terrence; Zhang, Lihai; Barber, David S.; LoPachin, Richard M.

    2011-01-01

    α,β-Unsaturated carbonyls are an important class of chemicals involved in environmental toxicity and disease processes. Whereas adduction of cysteine residues on proteins is a well-documented reaction of these chemicals, such a generic effect cannot explain the molecular mechanism of cytotoxicity. Instead, more detailed information is needed regarding the possible specificity and kinetics of cysteine targeting and the quantitative relationship between adduct burden and protein dysfunction. To address these datagaps, purified human glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was incubated with acrylamide (ACR), acrolein or methylvinyl ketone (MVK). Results show that these α,β-unsaturated carbonyl toxicants inhibited GAPDH activity in a concentration-and time-dependent manner. The rank order of enzyme inhibition (KI); i.e., ACR << MVK < acrolein, was related to the calculated electrophilic reactivity of each compound and to the corresponding kinetics of cysteine adduct formation. Tandem mass spectrometry revealed that adduct formation was selective at lower concentrations; i.e., ACR preferentially formed adducts with Cys152 (residues 146-162). At higher concentrations, ACR also formed adducts with Cys156 and Cys247 (residues 235-248). Adduct formation at Cys152 was correlated to enzyme inhibition, which is consistent with the regulatory role of this residue in enzyme function and its location within the GAPDH active site. Further analyses indicated that Cys152 was present in a pKa-lowering microenvironment (pKa = 6.03) and, at physiological pH, the corresponding sulfhydryl group exists in the highly reactive nucleophilic thiolate-state. These data suggest a general cytotoxic mechanism where electrophilic α,β-unsaturated carbonyls selectively form adducts with reactive nucleophilic cysteine residues specifically associated with the active sites of proteins. These specialized cysteine residues are toxicologically relevant molecular targets, since chemical

  12. A Palladium-Catalyzed Carbonylation Approach to Eight-Membered Lactam Derivatives with Antitumor Activity.

    PubMed

    Mancuso, Raffaella; Raut, Dnyaneshwar S; Marino, Nadia; De Luca, Giorgio; Giordano, Cinzia; Catalano, Stefania; Barone, Ines; Andò, Sebastiano; Gabriele, Bartolo

    2016-02-24

    The reactivity of 2-(2-alkynylphenoxy)anilines under PdI2 /KI-catalyzed oxidative carbonylation conditions has been studied. Although a different reaction pathway could have been operating, N-palladation followed by CO insertion was the favored pathway with all substrates tested, including those containing an internal or terminal triple bond. This led to the formation of a carbamoylpalladium species, the fate of which, as predicted by theoretical calculations, strongly depended on the nature of the substituent on the triple bond. In particular, 8-endo-dig cyclization preferentially occurred when the triple bond was terminal, leading to the formation of carbonylated ζ-lactam derivatives, the structures of which have been confirmed by XRD analysis. These novel medium-sized heterocyclic compounds showed antitumor activity against both estrogen receptor-positive (MCF-7) and triple negative (MDA-MB-231) breast cancer cell lines. In particular, ζ-lactam 3 j' may represent a novel and promising antitumor agent because biological tests clearly demonstrate that this compound significantly reduces cell viability and motility in both MCF-7 and MDA-MB-231 breast cancer cell lines, without affecting normal breast epithelial cell viability. PMID:26821986

  13. Optimization and comparison of HPLC and RRLC conditions for the analysis of carbonyl-DNPH derivatives.

    PubMed

    de M Ochs, Soraya; Fasciotti, Maíra; Barreto, Renata P; de Figueiredo, Natália G; Albuquerque, Flávio C; Massa, M Cecília G Pontes; Gabardo, Irene; Pereira Netto, Annibal D

    2010-04-15

    Analytical conditions for the analysis of 15 carbonyl-DNPH derivatives were optimized and compared by high performance liquid chromatography (HPLC) and rapid resolution liquid chromatography (RRLC). Binary, ternary and quaternary mixtures of acetonitrile, isopropanol, methanol, tetrahydrofuran and water were evaluated under RRLC conditions employing a Zorbax Eclipse Plus C18 (50 mm x 4.6 mm x 1.8 microm) column and a Zorbax Eclipse Plus C18 (50 mm x 2.1 mm x 1.8 microm) column. The optimized conditions obtained employing the two RRLC columns were compared with those obtained using a Supelcosil C18 (250 mm x 4.6 mm x 5 microm; Supelco) that is designed for HPLC separation of DNPH derivatives. Chromatograms run with a Zorbax Eclipse Plus C18 (50 mm x 2.1 mm x 1.8 microm) column and a mobile phase composed of isopropanol, methanol, tetrahydrofuran and water led to the best separation conditions considering reduced analysis time (approximately 6 min per run), solvent consumption rate (approximately 2 mL per run) and resolution of propanone, acrolein and propionaldehyde hydrazones. Quantification limits and linear ranges were adequate for direct application of EPA TO-11 conditions in all sets of RRLC and HPLC conditions. The analytical method was applied in the determination of carbonyl compounds (CCs) in Niterói City, RJ, Brazil in samples that were collected during periods of 2h. Formaldehyde (8.22-9.78 ppbv) predominated in all periods followed by acetaldehyde (1.77-3.99ppbv) and propanone (1.89-3.26 ppbv). Heavy CCs such as butyraldehyde and benzaldehyde were also detected in most samples. Total CCs varied along the studied day. The obtained results showed that RRLC can be applied to CCs determination without any change in the conditions of sample preparation of the Method EPA TO-11. PMID:20188957

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

    NASA Astrophysics Data System (ADS)

    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.

  15. On the Formation of Amide Polymers via Carbonyl-Amino Group Linkages in Energetically Processed Ices of Astrophysical Relevance

    NASA Astrophysics Data System (ADS)

    Förstel, Marko; Maksyutenko, Pavlo; Jones, Brant M.; Sun, Bing J.; Lee, Huan C.; Chang, Agnes H. H.; Kaiser, Ralf I.

    2016-04-01

    We report on the formation of organic amide polymers via carbonyl-amino group linkages in carbon monoxide and ammonia bearing energetically processed ices of astrophysical relevance. The first group comprises molecules with one carboxyl group and an increasing number of amine moieties starting with formamide (45 u), urea (60 u), and hydrazine carboxamide (75 u). The second group consists of species with two carboxyl (58 u) and up to three amine groups (73 u, 88 u, and 103 u). The formation and polymerization of these linkages from simple inorganic molecules via formamide und urea toward amide polymers is discussed in an astrophysical and astrobiological context. Our results show that long chain molecules, which are closely related to polypeptides, easily form by energetically processing simple, inorganic ices at very low temperatures and can be released into the gas phase by sublimation of the ices in star-forming regions. Our experimental results were obtained by employing reflectron time-of-flight mass spectroscopy, coupled with soft, single photon vacuum ultraviolet photoionization; they are complemented by theoretical calculations.

  16. Antagonism between lipid-derived reactive carbonyls and phenolic compounds in the Strecker degradation of amino acids.

    PubMed

    Delgado, Rosa M; Hidalgo, Francisco J; Zamora, Rosario

    2016-03-01

    The Strecker-type degradation of phenylalanine in the presence of 2-pentanal and phenolic compounds was studied to investigate possible interactions that either promote or inhibit the formation of Strecker aldehydes in food products. Phenylacetaldehyde formation was promoted by 2-pentenal and also by o- and p-diphenols, but not by m-diphenols. This is consequence of the ability of phenolic compounds to be converted into reactive carbonyls and produce the Strecker degradation of the amino acid. When 2-pentenal and phenolic compounds were simultaneously present, an antagonism among them was observed. This antagonism is suggested to be a consequence of the ability of phenolic compounds to either react with both 2-pentenal and phenylacetaldehyde, or compete with other carbonyl compounds for the amino acids, a function that is determined by their structure. All these results suggest that carbonyl-phenol reactions may be used to modulate flavor formation produced in food products by lipid-derived reactive carbonyls. PMID:26471665

  17. Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane

    PubMed Central

    Ayoup, Mohammed Salah; Cordes, David B; Slawin, Alexandra M Z

    2015-01-01

    Summary Palladium catalysed carbonylation reactions using the meta- and para-iodo derivatives of all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane (4) are illustrated as the start point for a variety of functional group interconversions. The resultant benzaldehyde and benzoic acids offer novel building blocks for further derivatisation and facilitate the incorporation of the facially polarised all-cis-1,2,4,5-tetrafluorocyclohexane motif into more advanced molecular scaffolds. PMID:26877788

  18. 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives.

    PubMed

    Meyer, Adam G; Ryan, John H

    2016-01-01

    We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carboxyl systems, in particular isatoic anhydrides and phthalic anhydrides. Intramolecular cycloadditions with esters can also occur under certain circumstances. The oxazolidine cycloadducts undergo a range of reactions triggered by the ring-opening of the oxazolidine ring system. PMID:27455230

  19. A rhenium tris-carbonyl derivative as a model molecule for incorporation into phospholipid assemblies for skin applications.

    PubMed

    Fernández, Estibalitz; Rodríguez, Gelen; Hostachy, Sarah; Clède, Sylvain; Cócera, Mercedes; Sandt, Christophe; Lambert, François; de la Maza, Alfonso; Policar, Clotilde; López, Olga

    2015-07-01

    A rhenium tris-carbonyl derivative (fac-[Re(CO)3Cl(2-(1-dodecyl-1H-1,2,3,triazol-4-yl)-pyridine)]) was incorporated into phospholipid assemblies, called bicosomes, and the penetration of this molecule into skin was monitored using Fourier-transform infrared microspectroscopy (FTIR). To evaluate the capacity of bicosomes to promote the penetration of this derivative, the skin penetration of the Re(CO)3 derivative dissolved in dimethyl sulfoxide (DMSO), a typical enhancer, was also studied. Dynamic light scattering results (DLS) showed an increase in the size of the bicosomes with the incorporation of the Re(CO)3 derivative, and the FTIR microspectroscopy showed that the Re(CO)3 derivative incorporated in bicosomes penetrated deeper into the skin than when dissolved in DMSO. When this molecule was applied on the skin using the bicosomes, 60% of the Re(CO)3 derivative was retained in the stratum corneum (SC) and 40% reached the epidermis (Epi). Otherwise, the application of this molecule via DMSO resulted in 95% of the Re(CO)3 derivative being in the SC and only 5% reaching the Epi. Using a Re(CO)3 derivative with a dodecyl-chain as a model molecule, it was possible to determine the distribution of molecules with similar physicochemical characteristics in the skin using bicosomes. This fact makes these nanostructures promising vehicles for the application of lipophilic molecules inside the skin. PMID:25969419

  20. Slurry-phase Fischer-Tropsch synthesis and kinetic studies over supported cobalt carbonyl derived catalysts

    SciTech Connect

    Withers, H.P. Jr.; Eliezer, K.F.; Mitchell, J.W. )

    1990-09-01

    This paper reports the preparation characterization, and performance of cobalt carbonyl cluster based catalysts for use in slurry-phase Fischer--Tropsch (FT) technology investigated. Using metal carbonyls as active metal precursors allows for the control of metal particle size on the support surface, thus offering the potential for better control of activity and selectivity of the FT reaction. Silica as the support provided the highest catalyst activities. A Co{sub 2}(CO){sub 8}/Zr(OPr){sub 4}/SiO{sub 2} catalyst (3.5% cobalt, 6.6% zirconium) was developed as the most active system in the FT slurry reactor and also gave the best liquid fuel selectivity. Selectivity patterns correlated to the Schulz--Flory prediction. These catalysts exhibited low water/gas shift activity. Diesel fuel product produced by this catalyst was high quality. A kinetic expression that took water inhibition into account was verified, yielding an activation energy of 97 kJ/mol for syngas conversion ranging from 34% to 71% at 240--280{degrees} C.

  1. Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of o-Carbonyl Carbazolequinone Derivatives

    PubMed Central

    Martínez-Cifuentes, Maximiliano; Clavijo-Allancan, Graciela; Zuñiga-Hormazabal, Pamela; Aranda, Braulio; Barriga, Andrés; Weiss-López, Boris; Araya-Maturana, Ramiro

    2016-01-01

    A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules. PMID:27399676

  2. Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of o-Carbonyl Carbazolequinone Derivatives.

    PubMed

    Martínez-Cifuentes, Maximiliano; Clavijo-Allancan, Graciela; Zuñiga-Hormazabal, Pamela; Aranda, Braulio; Barriga, Andrés; Weiss-López, Boris; Araya-Maturana, Ramiro

    2016-01-01

    A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules. PMID:27399676

  3. Manganese carbonyl derivatives based on Keggin- or Dawson-type polyoxoanions

    NASA Astrophysics Data System (ADS)

    Zhao, Juan; Zhao, Junwei; Ma, Pengtao; Wang, Jingping; Niu, Jingyang; Wang, Junsheng

    2012-07-01

    The reactions of [Mn(CO)5]Br with saturated Keggin- or Dawson-type polyoxometalate precursors in the CH3CN/H2O mixed solvent have led to the formation of a series of compounds based on polyoxoanions and manganese carbonyl groups [Mn(CO)3(CH3CN)3]n[α-XM12O40] [n = 3, X = PV, M = MoVI (1), WVI (2)], [Mn(CO)3(CH3CN)3]n[α-XM12O40]·1.5H2O [n = 4, X = SiIV, M = MoVI, (3)], [Mn(CO)3(CH3CN)3]nH[α-XM12O40] [n = 3, X = GeIV, M = MoVI (4)] and [Mn(CO)3(CH3CN)3]6[α-X2M18O62]·H2O [X = PV, M = MoVI (5), WVI (6); X = AsV, M = MoVI (7), WVI (8)], which have been characterized by elemental analyses, IR spectra, X-ray photoelectron spectroscopy (XPS), thermogravimatric (TG) analyses and single-crystal X-ray diffraction. 1, 2 and 4 are isomorphous and crystallize in the trigonal space group P-3. While 5-8 are also isostructural and belong to the monoclinic space group P2(1)/c, but 3 crystallizes in the triclinic space group P-1. Single-crystal X-ray diffraction analyses indicate that 1-8 commonly consist of [Mn(CO)3(CH3CN)3]+ cations and polyoxoanions, which are combined by electrostatic interaction.

  4. Reductive Umpolung of Carbonyl Derivatives with Visible-Light Photoredox Catalysis: Direct Access to Vicinal Diamines and Amino Alcohols via α-Amino Radicals and Ketyl Radicals.

    PubMed

    Fava, Eleonora; Millet, Anthony; Nakajima, Masaki; Loescher, Sebastian; Rueping, Magnus

    2016-06-01

    Visible-light-mediated photoredox-catalyzed aldimine-aniline and aldehyde-aniline couplings have been realized. The reductive single electron transfer (SET) umpolung of various carbonyl derivatives enabled the generation of intermediary ketyl and α-amino radical anions, which were utilized for the synthesis of unsymmetrically substituted 1,2-diamines and amino alcohols. PMID:27136443

  5. Development of ultrafast photochromic organometallics and photoinduced linkage isomerization of arene chromium carbonyl derivatives.

    PubMed

    To, Tung T; Heilweil, Edwin J; Duke, Charles B; Ruddick, Kristie R; Webster, Charles Edwin; Burkey, Theodore J

    2009-03-26

    We review recent studies of processes relevant to photoinduced linkage isomerization of organometallic systems with the goal of preparing organometallics with an efficient and ultrafast photochromic response. The organometallic system thus corresponds to two linkage isomers with different electronic environments that are responsible for different optical properties. Much of this work has focused on examining processes following irradiation of cyclopentadienyl manganese tricarbonyl derivatives (compounds 3-21) including solvent coordination, thermal relaxation, solvent displacement by tethered functional groups (chelation), dissociation of tethered functional groups, and linkage isomerization. A new platform is investigated for obtaining a photochromic response in new experiments with arene chromium dicarbonyl complexes. A photochromic response is observed for arene chromium dicarbonyl complexes with tethered pyridine and olefin functional groups based on light-driven linkage isomerization on the nanosecond time scale. Irradiation at 532 nm of 23 ([Cr{eta(6)-C(6)H(5)CH(2-Py-kappaN)CH(2)CH=CH(2)}(CO)(2)]) (Py = pyridine) results in the isomerization to 22 ([Cr{eta(6)-C(6)H(5)CH(2-Py)CH(2)-eta(2)-CH=CH(2)}(CO)(2)]), and 355 nm irradiation isomerizes 22 to 23. The ultrafast linkage isomerization has been investigated at room temperature in n-heptane solution on the picosecond to microsecond time scale with UV- or visible-pump and IR-probe transient absorption spectroscopy by comparing the dynamics with model compounds containing only a tethered pyridine. Irradiation of 24 ([Cr{eta(6)-C(6)H(5)(CH(2))(3)(2-Py)}(CO)(3)]) and 25 ([Cr{eta(6)-C(6)H(5)(CH(2))(2)(2-Py)}(CO)(3)]) at 289 nm induces CO loss to immediately yield a Cr-heptane solvent coordinated intermediate of the unsaturated Cr fragment, which then converts to the kappaN(1)-pyridine chelate within 200 and 100 ns, respectively. Irradiation of 26 ([Cr{eta(6)-C(6)H(5)CH(2)(2-Py)}(CO)(3)]) also induces CO loss to

  6. Product-Derived Bimetallic Palladium Complex Catalyzes Direct Carbonylation of Sulfonylazides.

    PubMed

    Zhao, Jin; Li, Zongyang; Song, Shaole; Wang, Ming-An; Fu, Bin; Zhang, Zhenhua

    2016-04-25

    A novel product-derived bimetallic palladium complex catalyzes a sulfonylazide-transfer reaction with the σ-donor/π-acceptor ligand CO, and is advantageous given its broad substrate scope, high efficiency, and mild reaction conditions (atmospheric pressure of CO at room temperature). This methodology provides a new approach to sulfonylureas, which are present in both pharmaceuticals and agrochemicals. The synthesis of Glibenclamide on a gram scale further revealed the practical utility of this procedure. Mechanistically, the generation of a bridged bimetallic palladium species derived from the product sulfonylurea is disclosed as the crucial step for this catalytic cycle. PMID:27005748

  7. Aldo-keto reductase family 1 B10 protein detoxifies dietary and lipid-derived alpha, beta-unsaturated carbonyls at physiological levels

    SciTech Connect

    Zhong, Linlin; Liu, Ziwen; Yan, Ruilan; Johnson, Stephen; Zhao, Yupei; Fang, Xiubin; Cao, Deliang

    2009-09-18

    Alpha, beta-unsaturated carbonyls are highly reactive mutagens and carcinogens to which humans are exposed on a daily basis. This study demonstrates that aldo-keto reductase family 1 member B10 (AKR1B10) is a critical protein in detoxifying dietary and lipid-derived unsaturated carbonyls. Purified AKR1B10 recombinant protein efficiently catalyzed the reduction to less toxic alcohol forms of crotonaldehyde at 0.90 {mu}M, 4-hydroxynonenal (HNE) at 0.10 {mu}M, trans-2-hexanal at 0.10 {mu}M, and trans-2,4-hexadienal at 0.05 {mu}M, the concentrations at or lower than physiological exposures. Ectopically expressed AKR1B10 in 293T cells eliminated immediately HNE at 1 (subtoxic) or 5 {mu}M (toxic) by converting to 1,4-dihydroxynonene, protecting the cells from HNE toxicity. AKR1B10 protein also showed strong enzymatic activity toward glutathione-conjugated carbonyls. Taken together, our study results suggest that AKR1B10 specifically expressed in the intestine is physiologically important in protecting the host cell against dietary and lipid-derived cytotoxic carbonyls.

  8. Fast photolysis of carbonyl nitrates from isoprene

    NASA Astrophysics Data System (ADS)

    Müller, Jean-Francois; Peeters, Jozef; Stavrakou, Trisevgeni

    2014-05-01

    We show that photolysis is, by far, the major atmospheric sink of isoprene-derived carbonyl nitrates. Empirical evidence from published laboratory studies on the absorption cross sections and photolysis rates of α-nitrooxy ketones suggests that the presence of the nitrate group (i) greatly enhances the absorption cross sections, and (ii) facilitates dissociation to a point that the photolysis quantum yield is close to unity, with O-NO2 dissociation as the likely major channel. On this basis, we provide new recommendations for estimating the cross sections and photolysis rates of carbonyl nitrates. The newly estimated photorates are validated using a chemical box model against measured temporal profiles of carbonyl nitrates in an isoprene oxidation experiment by Paulot et al. (2009). The comparisons for ethanal nitrate and for the sum of methacrolein- and methylvinylketone nitrates strongly supports our assumptions of large cross section enhancements and a near-unit quantum yield for these compounds. These findings have significant atmospheric implications, as carbonyl nitrates constitute an important component of the total organic nitrate pool over vegetated areas: the photorates of key carbonyl nitrates from isoprene are estimated to be typically between ~3 and 20 times higher than their sink due to reaction with OH in relevant atmospheric conditions. Moreover, since the reaction is expected to release NO2, photolysis is especially effective in depleting the total organic nitrate pool.

  9. Evaluation of ternary mobile phases for the analysis of carbonyl compound derivatives using high-performance liquid chromatography.

    PubMed

    Ho, Duy Xuan; Kim, Ki-Hyun

    2011-01-01

    In this study, the feasibility of ternary mobile phases was examined in a high-performance liquid chromatography (HPLC)-based analysis of carbonyl compounds (CCs). To test the performance of different ternary phases, the liquid phase standards containing a 15 aldehyde/ketone-DNPH(o) mix were analyzed through a series of five-point calibration experiments. For this comparison, three types of ternary mobile phases were prepared initially by mixing water (W) with two of the following three organic solvents: isopropanol (I), methanol (M), and tetrahydrofuran (T). The resulting three types of ternary phases (named as WIM, WTM, and WIT) were tested and evaluated in relation to the water content or in terms of methanol-to-water ratio (M/W). The results derived by the three ternary phases revealed that the optimal resolution was attained near maximum water content, while those of WIT consistently suffered from poor resolution problems. The relative performances of WIM and WTM phases, if assessed by three key operating parameters (sensitivity, retention time, and resolution), were found to be reliable for most selected CCs with the decreasing M/W ratio. PMID:21218260

  10. Engineering of Corynebacterium glutamicum to utilize methyl acetate, a potential feedstock derived by carbonylation of methanol with CO.

    PubMed

    Choo, Seungjung; Um, Youngsoon; Han, Sung Ok; Woo, Han Min

    2016-04-20

    The possibilities to utilize one-carbon substrates (C1) like CO, methane and methanol have been explored as a cheap alternative feedstock in the biotechnology. For the first time, methyl acetate (MeOAc), which can be formed from carbonylation of methanol with CO, was demonstrated to be an alternative carbon source for the cell growth of Corynebacterium glutamicum as a model microbial cell factory. To do so, a carboxyl esterase activity was necessary to hydrolyze MeOAc to methanol and acetate. Although the wild-type has an unknown esterase activity to MeOAc, the activity was not high enough to grow from 270mM MeOAc as sole carbon source, reaching OD600 of 5.28±0.2 in 32h. Based on the literatures studied for the esterase, we chose three esterases (MekB of Pseudomonas veronii MEK700, AcmB of Gordonia sp. Strain TY-5, and Est of Pyrobaculum calidifontis VA1) and cloned into the wild-type. As a result, the recombinant C. glutamicum expressing the highly active MekB esterase (28.6±0.77U/mg protein) showed complete degradation of MeOAc and utilization of acetate, resulting in OD600 of 16.5±0.02at 24h. In addition, the recombinant strain exhibited the rapid degradation of MeOAc to methanol and acetate in 2h under anaerobic condition. Therefore, MeOAc can be used as another C1-derived carbon source in the biotechnology. PMID:26970052

  11. Screening and evaluation of antioxidant activity of some amido-carbonyl oxime derivatives and their radical scavenging activities.

    PubMed

    Ozen, Tevfik; Taş, Murat

    2009-10-01

    The antioxidant activity of some amido-carbonyl oximes containing a C=O and -NH-R adjacent to the oxime group, [Phenyl-C(=O)-C(=N-OH)-N(-H)-Phenyl(-R)] where R= H, 4-chloro, 4-methyl, 4-methoxy, 3,4-dichloro, 3,4-dimethyl, 3-chloro-4-dimethyl, 3-chloro-4-methoxy, naphthyl and an amido-carbonyl dioxime were investigated in vitro by ferric thiocyanate, total reducing power by potassium ferricyanide reduction, 1,1-diphenyl-2- picryl-hydrazyl (DPPH(.)) free radical scavenging, ferrous ions chelating, superoxide anion radical scavenging and hydrogen peroxide scavenging activity assays. The results indicated that the amido-carbonyl oximes have powerful antioxidant capacity. PMID:19772487

  12. Nickel carbonyl

    Integrated Risk Information System (IRIS)

    Nickel carbonyl ; CASRN 13463 - 39 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  13. Carbonyl sulfide

    Integrated Risk Information System (IRIS)

    Carbonyl sulfide ; CASRN 463 - 58 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  14. Fast photolysis of carbonyl nitrates from isoprene

    NASA Astrophysics Data System (ADS)

    Müller, J.-F.; Peeters, J.; Stavrakou, T.

    2014-03-01

    Photolysis is shown to be a major sink for isoprene-derived carbonyl nitrates, which constitute an important component of the total organic nitrate pool over vegetated areas. Empirical evidence from published laboratory studies on the absorption cross sections and photolysis rates of α-nitrooxy ketones suggests that the presence of the nitrate group (i) greatly enhances the absorption cross sections and (ii) facilitates dissociation to a point that the photolysis quantum yield is close to unity, with O-NO2 dissociation as a likely major channel. On this basis, we provide new recommendations for estimating the cross sections and photolysis rates of carbonyl nitrates. The newly estimated photo rates are validated using a chemical box model against measured temporal profiles of carbonyl nitrates in an isoprene oxidation experiment by Paulot et al. (2009). The comparisons for ethanal nitrate and for the sum of methacrolein- and methyl vinyl ketone nitrates strongly supports our assumptions of large cross-section enhancements and a near-unit quantum yield for these compounds. These findings have significant atmospheric implications: the photorates of key carbonyl nitrates from isoprene are estimated to be typically between ~ 3 and 20 times higher than their sink due to reaction with OH in relevant atmospheric conditions. Moreover, since the reaction is expected to release NO2, photolysis is especially effective in depleting the total organic nitrate pool.

  15. Fast photolysis of carbonyl nitrates from isoprene

    NASA Astrophysics Data System (ADS)

    Müller, J.-F.; Peeters, J.; Stavrakou, T.

    2013-11-01

    Photolysis is shown to be a major sink for isoprene-derived carbonyl nitrates, which constitute an important component of the total organic nitrate pool over vegetated areas. Empirical evidence from published laboratory studies on the absorption cross sections and photolysis rates of α-nitrooxy ketones suggests that the presence of the nitrate group (i) greatly enhances the absorption cross sections, and (ii) facilitates dissociation to a point that the photolysis quantum yield is close to unity, with O-NO2 dissociation as the likely major channel. On this basis, we provide new recommendations for estimating the cross sections and photolysis rates of carbonyl nitrates. The newly estimated photorates are validated using a chemical box model against measured temporal profiles of carbonyl nitrates in an isoprene oxidation experiment by Paulot et al. (2009). The comparisons for ethanal nitrate and for the sum of methacrolein- and methylvinylketone nitrates strongly supports our assumptions of large cross section enhancements and a near-unit quantum yield for these compounds. These findings have significant atmospheric implications: the photorates of key carbonyl nitrates from isoprene are estimated to be typically between ~3 and 20 times higher than their sink due to reaction with OH in relevant atmospheric conditions. Moreover, since the reaction is expected to release NO2, photolysis is especially effective in depleting the total organic nitrate pool.

  16. Direct Access to α,α-Difluoroacylated Arenes by Palladium-Catalyzed Carbonylation of (Hetero)Aryl Boronic Acid Derivatives.

    PubMed

    Andersen, Thomas L; Frederiksen, Mette W; Domino, Katrine; Skrydstrup, Troels

    2016-08-22

    A palladium-catalyzed carbonylative coupling of (hetero)aryl boronates or boronic acid salts with carbon monoxide and α-bromo-α,α-difluoroamides and bromo-α,α-difluoroesters is described herein. The method is useful for the synthesis of a diverse selection of (hetero)aryl α,α-difluoro-β-ketoamides and α,α-difluoro-β-ketoesters, which are useful building blocks for the generation of functionalized difluoroacylated and difluoroalkyl arenes. The method could be further extended to a one-pot protocol for the formation of difluoroacetophenones. PMID:27346239

  17. Children's derivation of scalar implicatures: Alternatives and relevance.

    PubMed

    Skordos, Dimitrios; Papafragou, Anna

    2016-08-01

    Utterances such as "Megan ate some of the cupcakes" are often interpreted as "Megan ate some but not all of the cupcakes". Such an interpretation is thought to arise from a pragmatic inference called scalar implicature (SI). Preschoolers typically fail to spontaneously generate SIs without the assistance of training or context that make the stronger alternative salient. However, the exact role of alternatives in generating SIs remains contested. Specifically, it is not clear whether children have difficulty with spontaneously generating possible informationally stronger scalemates, or with considering how alternatives might be relevant. We present three studies with English-speaking 5-year-olds and adults designed to address these questions. We show that (a) the accessibility of the stronger alternative is important for children's SI generation (Experiment 1); (b) the explicit presence of the stronger alternative leads children to generate SIs only when the stronger scalar term can easily be seen as relevant (Experiment 2); and (c) in contexts that establish relevant alternatives, the explicit presence of the stronger alternative is not necessary (Experiment 3). We conclude that children's considerations of lexical alternatives during SI-computation include an important role for conversational relevance. We also show that this more nuanced approach to the role of lexical alternatives in pragmatic inference unifies previously unconnected findings about children's early pragmatic development and bears on major accounts proposed to date for children's problems with SIs. PMID:27107741

  18. Interplay of carbonyl-carbonyl, Csbnd H⋯O and Csbnd H⋯π interactions in hierarchical supramolecular assembly of tartaric anhydrides - Tartaric acid and its O-acyl derivatives: Part 11

    NASA Astrophysics Data System (ADS)

    Madura, Izabela D.; Zachara, Janusz; Hajmowicz, Halina; Synoradzki, Ludwik

    2012-06-01

    The detailed analysis of molecular and crystal structure of the O-acyltartaric anhydrides is presented. The role of both intra- and intermolecular weak interactions is discussed. The Hirshfeld surfaces analysis in form of dnorm representation and decomposed finger print plots was used to find out the types of weak but directional carbonyl-carbonyl, Csbnd H⋯O and Csbnd H⋯π interactions. The major interactions at the subsequent levels of the crystal architecture were identified. The interplay between carbonyl-carbonyl interactions and Csbnd H⋯O hydrogen bonds both at the molecular level as well as in basic supramolecular motives was analyzed. In all cases the primary supramolecular motif was found to be the ribbon showing the p21 rod group symmetry. The key role of the ribbon motif is reflected in the hexagonal packing of rods.

  19. Direct photolysis of carbonyl compounds dissolved in cloud and fog droplets

    NASA Astrophysics Data System (ADS)

    Epstein, S. A.; Tapavicza, E.; Furche, F.; Nizkorodov, S. A.

    2013-04-01

    Gas phase photolysis is an important tropospheric sink for many carbonyl compounds, however the significance of direct photolysis of carbonyl compounds dissolved in cloud and fog droplets is uncertain. We develop a theoretical approach to assess the importance of aqueous photolysis for a series of carbonyls that possess carboxyl and hydroxyl functional groups by comparison with rates of other atmospheric processes. We use computationally and experimentally derived Henry's law parameters, hydration equilibrium parameters, aqueous hydroxyl radical (OH) rate constants, and optical extinction coefficients to identify types of compounds that will not have competitive aqueous photolysis rates. We also present molecular dynamics simulations of atmospherically relevant carbonyl compounds designed to estimate gas and aqueous phase extinction coefficients. In addition, experiments designed to measure the photolysis rate of glyceraldehyde, an atmospherically relevant water soluble organic compound, reveal that aqueous quantum yields are highly molecule-specific and cannot be extrapolated from measurements of structurally similar compounds. We find that only three out of the 92 carbonyl compounds investigated, pyruvic acid, 3-oxobutanoic acid, and 3-oxopropanoic acid, may have aqueous photolysis rates that exceed the rate of oxidation by dissolved OH. For almost all carbonyl compounds lacking α, β conjugation, atmospheric removal by direct photolysis in cloud and fog droplets can be neglected.

  20. Biological evaluation of synthetic α,β-unsaturated carbonyl based cyclohexanone derivatives as neuroprotective novel inhibitors of acetylcholinesterase, butyrylcholinesterase and amyloid-β aggregation.

    PubMed

    Zha, Gao-Feng; Zhang, Cheng-Pan; Qin, Hua-Li; Jantan, Ibrahim; Sher, Muhammad; Amjad, Muhammad Wahab; Hussain, Muhammad Ajaz; Hussain, Zahid; Bukhari, Syed Nasir Abbas

    2016-05-15

    A series of new α,β-unsaturated carbonyl-based cyclohexanone derivatives was synthesized by simple condensation method and all compounds were characterized by using various spectroscopic techniques. New compounds were evaluated for their effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These compounds were also screened for in vitro cytotoxicity and for inhibitory activity for self-induced Aβ1-42 aggregation. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. The findings of in vitro experiment revealed that most of these compounds exhibited potent inhibitory activity against AChE and self-induced Aβ1-42 aggregation. The compound 3o exhibited best AChE (IC50=0.037μM) inhibitory potential. Furthermore, compound 3o disassembled the Aβ fibrils produced by self-induced Aβ aggregation by 76.6%. Compounds containing N-methyl-4-piperidone linker, showed high acetylcholinesterase and self-induced Aβ aggregation inhibitory activities as compared to reference drug donepezil. The pre-treatment of cells with synthetic compounds protected them against Aβ-induced cell death by up to 92%. Collectively, these findings suggest that some compounds from this series have potential to be promising multifunctional agents for AD treatment and our study suggest the cyclohexanone derivatives as promising new inhibitors for AChE and BuChE, potentially useful to treat neurodegenerative diseases. PMID:27083471

  1. Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative.

    PubMed

    Guarisco, Chiara; Palmisano, Giovanni; Calogero, Giuseppe; Ciriminna, Rosaria; Di Marco, Gaetano; Loddo, Vittorio; Pagliaro, Mario; Parrino, Francesco

    2014-10-01

    Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N'-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2-propanol. The reaction was carried out under cut-off (λ > 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was evaluated by cyclic voltammetry. The optimal organic sensitizing amount was found to be 5.6 % w/w in terms of yield in carbonyl derivatives. Moreover, no change in reactivity/selectivity was observed after 10-h irradiation thus confirming the catalyst stability. Yields into formaldehyde, acetaldehyde, and acetone were 67, 70, and 96 %, respectively. No significant amounts of organic byproducts were detected but for methanol oxidation, whereas a minor amount of the substrate degraded to CO2. PMID:24469771

  2. Preparation of 1-fluoro-4-methyl-9H-[carbonyl-(14) C]thioxanthen-9-one and amine derivatives.

    PubMed

    Javaheri, Mohsen; Shirvani, Gholamhossein; Amini, Mohsen; Saemian, Nader; Saadatjoo, Naghi

    2016-06-30

    9H-Thioxanthen-9-ones are an important class of compound and are a common heterocyclic scaffold in biologically active and medicinally significant compounds. In this paper the synthesis of 1-fluoro-4-methyl-9H-thioxanthen-9-one and some amine derivatives labeled with carboxyl-14 is described. PMID:27157134

  3. Hydroxyl-Assisted Carbonylation of Alkenyltin Derivatives: Development and Application to a Formal Synthesis of Tubelactomicin A.

    PubMed

    Sommer, Heiko; Fürstner, Alois

    2016-07-01

    Alkenyltin derivatives flanked by a hydroxyl group are subject to methoxycarbonylation when treated with catalytic amounts of Pd(OAc)2 and Ph3As in MeOH under a CO atmosphere; key to success is the use of 1,4-benzoquinone as a stoichiometric oxidant in combination with trifluoroacetic acid as a cocatalyst. The acid lowers the LUMO of the quinone and likely marshals the critical assembly of the substrates. Under the optimized conditions, competing proto-destannation is marginal; the method proved compatible with various (acid sensitive) functional groups and was applied to a short formal total synthesis of the antibiotic tubelactomicin A. PMID:27280547

  4. High-nuclearity ruthenium carbonyl cluster complexes derived from 2-amino-6-methylpyridine: synthesis of nonanuclear derivatives containing mu4- and mu5-oxo ligands.

    PubMed

    Cabeza, Javier A; del Río, Ignacio; García-Alvarez, Pablo; Miguel, Daniel

    2006-07-24

    Nonanuclear cluster complexes [Ru9(mu3-H)2(mu-H)(mu5-O)(mu4-ampy)(mu3-Hampy)(CO)21] (4) (H2ampy = 2-amino-6-methylpyridine), [Ru9(mu5-O)2(mu4-ampy)(mu3-Hampy)2(mu-CO)(CO)20] (5), [Ru9(mu5-O)2(mu4-ampy)(mu3-Hampy)2(mu-CO)2(CO)19] (6), and [Ru9(mu4-O)(mu5-O)(mu4-ampy)(mu3-Hampy)(mu-Hampy)(mu-CO)(CO)19] (7), together with the known hexanuclear [Ru6(mu3-H)2(mu5-ampy)(mu-CO)2(CO)14] (2) and the novel pentanuclear [Ru5(mu4-ampy)(2)(mu-CO)(CO)12] (3) complexes, are products of the thermolysis of [Ru3(mu-H)(mu3-Hampy)(CO)9] (1) in decane at 150 degrees C. Two different and very unusual quadruply bridging coordination modes have been observed for the ampy ligand. Compounds 4-7 also feature one (4) or two (5-7) bridging oxo ligands. With the exception of one of the oxo ligands of 7, which is in a distorted tetrahedral environment, the remaining oxo ligands of 4-7 are surrounded by five metal atoms. In carbonyl metal clusters, quadruply bridging oxo ligands are very unusual, whereas quintuply bridging oxo ligands are unprecedented. By using 18O-labeled water, we have unambiguously established that these oxo ligands arise from water. PMID:16842009

  5. 6-amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives as a new class of potent inhibitors of Interleukin-8-induced neutrophil chemotaxis.

    PubMed

    Cesarini, Sara; Spallarossa, Andrea; Ranise, Angelo; Bruno, Olga; Arduino, Nicoletta; Bertolotto, Maria; Dallegri, Franco; Tognolini, Massimiliano; Gobbetti, Thomas; Barocelli, Elisabetta

    2009-05-15

    A series of 6-amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives was synthesized. The compounds demonstrated to be novel, potent and selective inhibitors of Interleukin-8-induced human neutrophil chemotaxis. A SAR study was performed by varying the carbonyl function at position 5 and the chain linked to the amino group at position 6 of the scaffold. All the compounds of the series displayed inhibitory activity at nano- or picomolar concentrations against Interleukin-8-driven migration and no activity against fMLP- and C5a-induced chemotaxis. The binding tests of selected compounds on CXCR1 and CXCR2 receptors were negative. The most potent derivative showed in vivo efficacy in a mouse model of Zymosan-induced peritonitis. PMID:19394230

  6. Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

    SciTech Connect

    Cutler, A. R.

    2001-04-14

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.

  7. Prospects for three-electron donor boronyl (BO) ligands and dioxodiborene (B2O2) ligands as bridging groups in binuclear iron carbonyl derivatives.

    PubMed

    Chang, Yu; Li, Qian-Shu; Xie, Yaoming; King, R Bruce

    2012-08-20

    Recent experimental work (2010) on (Cy(3)P)(2)Pt(BO)Br indicates that the oxygen atom of the boronyl (BO) ligand is more basic than that in the ubiquitous CO ligand. This suggests that bridging BO ligands in unsaturated binuclear metal carbonyl derivatives should readily function as three-electron donor bridging ligands involving both the oxygen and the boron atoms. In this connection, density functional theory shows that three of the four lowest energy singlet Fe(2)(BO)(2)(CO)(7) structures have such a bridging η(2)-μ-BO group as well as a formal Fe-Fe single bond. In addition, all four of the lowest energy singlet Fe(2)(BO)(2)(CO)(6) structures have two bridging η(2)-μ-BO groups and formal Fe-Fe single bonds. Other Fe(2)(BO)(2)(CO)(n) (n = 7, 6) structures are found in which the two BO groups have coupled to form a bridging dioxodiborene (B(2)O(2)) ligand with B-B bonding distances of ~1.84 Å. All of these Fe(2)(μ-B(2)O(2))(CO)(n) structures have long Fe···Fe distances indicating a lack of direct iron-iron bonding. One of the singlet Fe(2)(BO)(2)(CO)(7) structures has such a bridging dioxodiborene ligand with cis stereochemistry functioning as a six-electron donor to the pair of iron atoms. In addition, the lowest energy triplet structures for both Fe(2)(BO)(2)(CO)(7) and Fe(2)(BO)(2)(CO)(6) have bridging dioxodiborene ligands with trans stereochemistry functioning as a four-electron donor to the pair of iron atoms. PMID:22862812

  8. Reactive intermediates relevant to the carbonylation of CH3Mn(CO)5. Activation parameters for key dynamic processes S. Massick, V. Mertens, J. Marhenke, P. C. Ford, Inorg. Chem. 2002, 41, 3553-3559

    SciTech Connect

    Ford, Peter C.; S.M. Massick; V. Mertens; J. Marhenke; S. Bernhard; J.R. Schoonover

    2002-12-31

    OAK-B135 Mechanisms of the homogeneous catalytic and photocatalytic activation of small molecules such as carbon monoxide, dihydrogen and various hydrocarbons. Time-resolved spectroscopic investigations of rhodium and iridium halo carbonyl complex intermediates proposed in methanol carbonylation catalysts.

  9. Concise review: the relevance of human stem cell-derived organoid models for epithelial translational medicine.

    PubMed

    Hynds, Robert E; Giangreco, Adam

    2013-03-01

    Epithelial organ remodeling is a major contributing factor to worldwide death and disease, costing healthcare systems billions of dollars every year. Despite this, most fundamental epithelial organ research fails to produce new therapies and mortality rates for epithelial organ diseases remain unacceptably high. In large part, this failure in translating basic epithelial research into clinical therapy is due to a lack of relevance in existing preclinical models. To correct this, new models are required that improve preclinical target identification, pharmacological lead validation, and compound optimization. In this review, we discuss the relevance of human stem cell-derived, three-dimensional organoid models for addressing each of these challenges. We highlight the advantages of stem cell-derived organoid models over existing culture systems, discuss recent advances in epithelial tissue-specific organoids, and present a paradigm for using organoid models in human translational medicine. PMID:23203919

  10. Organocatalyzed Intramolecular Carbonyl-Ene Reactions.

    PubMed

    Dahlmann, Heidi A; McKinney, Amanda J; Santos, Maria P; Davis, Lindsey O

    2016-01-01

    An organocatalyzed intramolecular carbonyl-ene reaction was developed to produce carbocyclic and heterocyclic 5- and 6-membered rings from a citronellal-derived trifluoroketone and a variety of aldehydes. A phosphoramide derivative was found to promote the cyclization of the trifluoroketone, whereas a less acidic phosphoric acid proved to be a superior catalyst for the aldehyde substrates. PMID:27258238

  11. Direct photolysis of carbonyl compounds dissolved in cloud and fog~droplets

    NASA Astrophysics Data System (ADS)

    Epstein, S. A.; Tapavicza, E.; Furche, F.; Nizkorodov, S. A.

    2013-09-01

    Gas-phase photolysis is an important tropospheric sink for many carbonyl compounds; however the significance of direct photolysis of these compounds dissolved in cloud and fog droplets is uncertain. We develop a theoretical approach to assess the importance of aqueous photolysis for a series of carbonyls that possess carboxyl and hydroxyl functional groups by comparison with rates of other atmospheric processes. We use computationally and experimentally derived effective Henry's law constants, hydration equilibrium parameters, aqueous hydroxyl radical (OH) rate constants, and optical extinction coefficients to identify types of compounds that will (or will not) have competitive aqueous photolysis rates. We also present molecular dynamics simulations designed to estimate gas- and aqueous-phase extinction coefficients of unstudied atmospherically relevant compounds found in d-limonene and isoprene secondary organic aerosol. In addition, experiments designed to measure the photolysis rate of glyceraldehyde, an atmospherically relevant water-soluble organic compound, reveal that aqueous quantum yields are highly molecule-specific and cannot be extrapolated from measurements of structurally similar compounds. We find that only two out of the 92 carbonyl compounds investigated, pyruvic acid and acetoacetic acid, may have aqueous photolysis rates that exceed the rate of oxidation by dissolved OH. For almost all carbonyl compounds lacking α,β-conjugation that were investigated, atmospheric removal by direct photolysis in cloud and fog droplets can be neglected under typical atmospheric conditions.

  12. Importance of being Nernst: Synaptic activity and functional relevance in stem cell-derived neurons

    PubMed Central

    Bradford, Aaron B; McNutt, Patrick M

    2015-01-01

    Functional synaptogenesis and network emergence are signature endpoints of neurogenesis. These behaviors provide higher-order confirmation that biochemical and cellular processes necessary for neurotransmitter release, post-synaptic detection and network propagation of neuronal activity have been properly expressed and coordinated among cells. The development of synaptic neurotransmission can therefore be considered a defining property of neurons. Although dissociated primary neuron cultures readily form functioning synapses and network behaviors in vitro, continuously cultured neurogenic cell lines have historically failed to meet these criteria. Therefore, in vitro-derived neuron models that develop synaptic transmission are critically needed for a wide array of studies, including molecular neuroscience, developmental neurogenesis, disease research and neurotoxicology. Over the last decade, neurons derived from various stem cell lines have shown varying ability to develop into functionally mature neurons. In this review, we will discuss the neurogenic potential of various stem cells populations, addressing strengths and weaknesses of each, with particular attention to the emergence of functional behaviors. We will propose methods to functionally characterize new stem cell-derived neuron (SCN) platforms to improve their reliability as physiological relevant models. Finally, we will review how synaptically active SCNs can be applied to accelerate research in a variety of areas. Ultimately, emphasizing the critical importance of synaptic activity and network responses as a marker of neuronal maturation is anticipated to result in in vitro findings that better translate to efficacious clinical treatments. PMID:26240679

  13. COATING URANIUM FROM CARBONYLS

    DOEpatents

    Gurinsky, D.H.; Storrs, S.S.

    1959-07-14

    Methods are described for making adherent corrosion resistant coatings on uranium metal. According to the invention, the uranium metal is heated in the presence of an organometallic compound such as the carbonyls of nickel, molybdenum, chromium, niobium, and tungsten at a temperature sufficient to decompose the metal carbonyl and dry plate the resultant free metal on the surface of the uranium metal body. The metal coated body is then further heated at a higher temperature to thermally diffuse the coating metal within the uranium bcdy.

  14. Daily calibration of seasonal forecasts to derive impact-relevant climate indices

    NASA Astrophysics Data System (ADS)

    Bhend, Jonas; Spirig, Christoph; Mahlstein, Irina; Liniger, Mark

    2015-04-01

    Climate information indices (CIIs) are impact-relevant quantities derived from basic meteorological variables such as rainfall or temperature. The computation of CIIs often involves absolute thresholds such as for the number of frost days per seasons or seasonal degree days. The dependence on absolute thresholds poses challenges in a forecasting context where such indices have to be derived from daily time series of forecasting systems with sometimes considerable systematic, time and location dependent biases. In order to reduce the effect of such biases on the skill of CII forecasts, the daily time series need to be calibrated before computing the CIIs. Here we analyze the performance and the effect of several bias correction and calibration methods on the skill of seasonal CII forecasts derived from the calibrated daily series. We use seasonal forecasts from the European Centre of Medium-Range Weather Forecasts' (ECMWF) System 4 for the period 1981-2012, with a focus on the winter season. The forecasts are verified against CIIs derived from the ERA-INTERIM reanalysis. We find that bias correction and calibration approaches have a positive effect on the skill of CII forecasts. For CIIs involving a moderate non-linearity (e.g. seasonal heating degree days), all correction and calibration methods result in similar skill. For CIIs with pronounced threshold dependency (e.g. seasonal frost days), skill is more sensitive to the choice of calibration method. However, the analyzed daily correction and calibration methods do not achieve to produce reliable forecasts of seasonally aggregated CIIs. Hence, an additional re-calibration of the CII forecasts is necessary to get well calibrated CII forecasts.

  15. Tolerance of human embryonic stem cell derived islet progenitor cells to vitrification-relevant solutions.

    PubMed

    Lahmy, Reyhaneh; Bolyukh, Vladimir F; Castilla, Sergio Mora; Laurent, Louise C; Katkov, Igor I; Itkin-Ansari, Pamela

    2015-06-01

    We have previously shown that human embryonic stem cell derived islet progenitors (hESC-IPs), encapsulated inside an immunoprotective device, mature in vivo and ameliorate diabetes in mice. The ability to cryopreserve hESC-IPs preloaded in these devices would enhance consistency and portability, but traditional 'slow freezing' methods did not work well for cells encapsulated in the device. Vitrification is an attractive alternative cryopreservation approach. To assess the tolerance of hESC-IPs to vitrification relevant conditions, we here are reporting cell survival following excursions in tonicity, exposure to fifteen 40% v/v combinations of 4 cryoprotectants, and varied methods for addition and elution. We find that 78% survival is achieved using a protocol in which cells are abruptly (in one step) exposed to a solution containing 10% v/v each dimethyl sulfoxide, propylene glycol, ethylene glycol, and glycerol on ice, and eluted step-wise with DPBS+0.5M sucrose at 37°C. Importantly, the hESC-IPs also maintain expression of the critical islet progenitor markers PDX-1, NKX6.1, NGN3 and NEURO-D1. Thus, hESC-IPs exhibit robust tolerance to exposure to vitrification solutions in relevant conditions. PMID:25817378

  16. Efficacious and Clinically Relevant Conditioned Medium of Human Adipose-derived Stem Cells for Therapeutic Angiogenesis

    PubMed Central

    Bhang, Suk Ho; Lee, Seahyoung; Shin, Jung-Youn; Lee, Tae-Jin; Jang, Hyeon-Ki; Kim, Byung-Soo

    2014-01-01

    Using stem cell–conditioned medium (CM) might be a viable alternative to stem cell transplantation, which is often hampered by low grafting efficiency and potential tumorigenesis, but the concentrations of angiogenic growth factors in CM are too low for therapeutic use and some components of the medium are not for human use. We used three-dimensional (3D) spheroid culture of human adipose-derived stem cells (ADSCs) with clinically relevant medium composed of amino acids, vitamins, glucose, and human serum to produce clinically relevant CM containing angiogenic and/or antiapoptotic factors such as vascular endothelial cell growth factor, fibroblast growth factor 2, hepatocyte growth factor, and chemokine (C-X-C motif) ligand 12. The concentrations of these factors were 23- to 27-fold higher than that in CM produced by conventional monolayer culture. Compared with injection of either monolayer culture CM or human ADSC, injection of spheroid culture CM to an ischemic region in mice significantly enhanced endothelial cell growth, CD34+/PTPRC− (endothelial progenitor) cell mobilization from bone marrow, and bone marrow cell homing to the ischemic region, resulting in improved blood vessel density, limb salvage, and blood perfusion in a mouse hindlimb ischemia model. The stem cell CM developed in this study will likely be an effective alternative to conventional stem cell transplantation therapy. PMID:24413377

  17. Hexaruthenium carbonyl cluster complexes with basal edge-bridged square pyramidal metallic skeleton: efficient synthesis of 2-imidopyridine derivatives and determination of their reactive sites in carbonyl substitution reactions.

    PubMed

    Cabeza, Javier A; del Río, Ignacio; García-Alvarez, Pablo; Miguel, Daniel; Riera, Víctor

    2004-08-23

    The reactions of [Ru(3)(CO)(12)] with half equivalent of 2-amino-6-methylpyridine (H(2)ampy) or 2-aminopyridine (H(2)apy) in refluxing xylene give the hexanuclear products [Ru(6)(mu(3)-H)(2)(mu(5)-eta(2)-L)(mu-CO)(2)(CO)(14)] (L = ampy, 1; apy, 2). These reactions represent the first high-yield syntheses of hexanuclear complexes with a basal edge-bridged square pyramidal metallic skeleton. Five metal atoms of these complexes are bridged by the N-donor ligand in such a way that the edge-bridging metal atom is attached to the pyridine nitrogen, while the basal atoms of the square pyramid are capped by an imido fragment that arises from the activation of both N-H bonds of the NH(2) group. The reactive sites of these complexes in CO substitution reactions have been determined by studying the reactivity of 1 with triphenylphosphine. Two kinetically controlled monosubstitutions take place on the edge-bridging metal atom in positions cis to the pyridine nitrogen, leading to a mixture of two isomers of formula [Ru(6)(mu(3)-H)(2)(mu(5)-eta(2)-ampy)(mu-CO)(2)(CO)(13)(PPh(3))] (3 and 4). On heating at 80 degrees C, these monosubstituted isomers are transformed, via a dissociative pathway, into the product of thermodynamic control (5), which has the PPh(3) ligand on the apical Ru atom. The di- and trisubstituted derivatives [Ru(6)(mu(3)-H)(2)(mu(5)-eta(2)-ampy)(mu-CO)(2)(CO)(12)(PPh(3))(2)] (6) and [Ru(6)(mu(3)-H)(2)(mu(5)-eta(2)-ampy)(mu-CO)(2)(CO)(11)(PPh(3))(3)] (7) are stepwise formed from 3-5 and PPh(3). Compound 6 has the PPh(3) ligands on the edge-bridging and apical Ru atoms, and compound 7 has an additional PPh(3) ligand on an unbridged basal Ru atom. The compound [Ru(6)(mu(3)-H)(2)(mu(5)-eta(2)-ampy)(mu-CO)(2)(CO)(12)(mu-dppm)] (8), in which a basal and the apical Ru atoms are spanned by the dppm ligand, has been isolated from the reaction of 1 with bis(diphenylphosphino)methane. PMID:15310227

  18. Miniaturized iPS-Cell-Derived Cardiac Muscles for Physiologically Relevant Drug Response Analyses

    PubMed Central

    Huebsch, Nathaniel; Loskill, Peter; Deveshwar, Nikhil; Spencer, C. Ian; Judge, Luke M.; Mandegar, Mohammad A.; B. Fox, Cade; Mohamed, Tamer M.A.; Ma, Zhen; Mathur, Anurag; Sheehan, Alice M.; Truong, Annie; Saxton, Mike; Yoo, Jennie; Srivastava, Deepak; Desai, Tejal A.; So, Po-Lin; Healy, Kevin E.; Conklin, Bruce R.

    2016-01-01

    Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly, and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch, and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro. PMID:27095412

  19. Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (Phb) from a Process Relevant Lignocellulosic Derived Sugar

    SciTech Connect

    Wang, Wei; Mohagheghi, Ali; Mittal, Ashutosh; Pilath, Heidi; Johnson, David K.

    2015-03-22

    PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. In recent years a great effort has been made in bacterial production of PHB, yet the production cost of the polymer is still much higher than conventional petrochemical plastics. The high cost of PHB is because the cost of the substrates can account for as much as half of the total product cost in large scale fermentation. Thus searching for cheaper and better substrates is very necessary for PHB production. In this study, we demonstrate production of PHB by Cupriavidus necator from a process relevant lignocellulosic derived sugar stream, i.e., saccharified hydrolysate slurry from pretreated corn stover. Good cell growth was observed on slurry saccharified with advanced enzymes and 40~60% of PHB was accumulated in the cells. The mechanism of inhibition in the toxic hydrolysate generated by pretreatment and saccharification of biomass, will be discussed.

  20. Miniaturized iPS-Cell-Derived Cardiac Muscles for Physiologically Relevant Drug Response Analyses.

    PubMed

    Huebsch, Nathaniel; Loskill, Peter; Deveshwar, Nikhil; Spencer, C Ian; Judge, Luke M; Mandegar, Mohammad A; B Fox, Cade; Mohamed, Tamer M A; Ma, Zhen; Mathur, Anurag; Sheehan, Alice M; Truong, Annie; Saxton, Mike; Yoo, Jennie; Srivastava, Deepak; Desai, Tejal A; So, Po-Lin; Healy, Kevin E; Conklin, Bruce R

    2016-01-01

    Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly, and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch, and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro. PMID:27095412

  1. Novel and Stress Relevant EST Derived SSR Markers Developed and Validated in Peanut

    PubMed Central

    Bosamia, Tejas C.; Mishra, Gyan P.; Thankappan, Radhakrishnan; Dobaria, Jentilal R.

    2015-01-01

    With the aim to increase the number of functional markers in resource poor crop like cultivated peanut (Arachis hypogaea), large numbers of available expressed sequence tags (ESTs) in the public databases, were employed for the development of novel EST derived simple sequence repeat (SSR) markers. From 16424 unigenes, 2784 (16.95%) SSRs containing unigenes having 3373 SSR motifs were identified. Of these, 2027 (72.81%) sequences were annotated and 4124 gene ontology terms were assigned. Among different SSR motif-classes, tri-nucleotide repeats (33.86%) were the most abundant followed by di-nucleotide repeats (27.51%) while AG/CT (20.7%) and AAG/CTT (13.25%) were the most abundant repeat-motifs. A total of 2456 EST-SSR novel primer pairs were designed, of which 366 unigenes having relevance to various stresses and other functions, were PCR validated using a set of 11 diverse peanut genotypes. Of these, 340 (92.62%) primer pairs yielded clear and scorable PCR products and 39 (10.66%) primer pairs exhibited polymorphisms. Overall, the number of alleles per marker ranged from 1-12 with an average of 3.77 and the PIC ranged from 0.028 to 0.375 with an average of 0.325. The identified EST-SSRs not only enriched the existing molecular markers kitty, but would also facilitate the targeted research in marker-trait association for various stresses, inter-specific studies and genetic diversity analysis in peanut. PMID:26046991

  2. 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.

    PubMed

    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. PMID:26189462

  3. High throughput assay for evaluation of reactive carbonyl scavenging capacity☆

    PubMed Central

    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. PMID:24688895

  4. Millimeter wave spectra of carbonyl cyanide

    NASA Astrophysics Data System (ADS)

    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

  5. Simultaneous determination of airborne carbonyls and aromatic hydrocarbons using mixed sorbent collection and thermal desorption-gas chromatography/mass spectrometric analysis.

    PubMed

    Chien, Yeh-Chung; Yin, Ko-Ghun

    2009-05-01

    Volatile organic chemicals (VOC) such as aromatics and carbonyls are ubiquitous, and have environmental and health significance. This work presents a novel analytical method for simultaneously monitoring airborne carbonyls compounds and aromatic hydrocarbons. Carbonyls were collected onto an adsorbent (Tenax TA, coated with pentafluorophenyl hydrazine (PFPH)) that reacted with carbonyl groups to form thermo-stable derivatives that are suitable for subsequent analysis by thermal-desorption and GC/MS. Aromatic hydrocarbons were collected onto Tenax TA that was packed in the same sampling tube, and analyzed using the same method as carbonyls. Six carbonyls (formaldehyde, acetaldehyde, benzaldehyde, acetone, methyl ethyl ketone and methyl isobutyl ketone) and five aromatics (benzene, toluene, ethylbenzene, xylenes and styrene) were evaluated following standard test protocols. Calibration ranges were 30-200 ng per tube for most test chemicals, and 200-1000 ng per tube for formaldehyde. The analytical precision was 7% or better, and the collection efficiency, tested using a static sampling bag, was between 94 and 98%. PFPH-coated Tenax TA (for collecting carbonyls) needs to be placed in the front section of the tube, and Tenax TA in the back section (for collecting aromatics). The method detection limits of the current method ranged between 0.2 and 25 ng per tube, which corresponded to sub- to 17.2 ppbv (for formaldehyde), based on a typical 6 l sample from a sampling rate of 25 ml/min. Samples were stable for at least ten days under ambient conditions. The proposed method was also tested in the field and proved satisfactory. The proposed method is simple, feasible and has an acceptable accuracy and precision. It can thus be adopted as a reference method for making relevant measurements. PMID:19436859

  6. Edge-bridging and face-capping coordination of alkenyl ligands in triruthenium carbonyl cluster complexes derived from hydrazines: synthetic, structural, theoretical, and kinetic studies.

    PubMed

    Cabeza, Javier A; del Río, Ignacio; Fernández-Colinas, José M; García-Granda, Santiago; Martínez-Méndez, Lorena; Pérez-Carreño, Enrique

    2004-12-01

    The reactions of the triruthenium cluster complex [Ru3(mu-H)(mu3-eta2-HNNMe2)(CO)9] (1; H2NNMe2=1,1-dimethylhydrazine) with alkynes (PhC triple bond CPh, HC triple bond CH, MeO2CC triple bond CCO2Me, PhC triple bond CH, MeO2CC triple bond CH, HOMe2CC triple bond CH, 2-pyC triple bond CH) give trinuclear complexes containing edge-bridging and/or face-capping alkenyl ligands. Whereas the edge-bridged products are closed triangular species (three Ru-Ru bonds), the face-capped products are open derivatives (two Ru-Ru bonds). For terminal alkynes, products containing gem (RCCH2) and/or trans (RHCCH) alkenyl ligands have been identified in both edge-bridging and face-capping positions, except for the complex [Ru3(mu3-eta2-HNNMe2)(mu3-eta3-HCCH-2-py)(mu-CO)(CO)7], which has the two alkenyl H atoms in a cis arrangement. Under comparable reaction conditions (1:1 molar ratio, THF at reflux, time required for the consumption of complex 1), some reactions give a single product, but most give mixtures of isomers (not all the possible ones), which were separated. To determine the effect of the hydrazido ligand, the reactions of [Ru3(mu-H)(mu3-eta2-MeNNHMe)(CO)9] (2; HMeNNHMe=1,2-dimethylhydrazine) with PhC triple bond CPh, PhC triple bond CH, and HC triple bond CH were also studied. For edge-bridged alkenyl complexes, the Ru--Ru edge that is spanned by the alkenyl ligand depends on the position of the methyl groups on the hydrazido ligand. For face-capped alkenyl complexes, the relative orientation of the hydrazido and alkenyl ligands also depends on the position of the methyl groups on the hydrazido ligand. A kinetic analysis of the reaction of 1 with PhC[triple chemical bond]CPh revealed that the reaction follows an associative mechanism, which implies that incorporation of the alkyne in the cluster is rate-limiting and precedes the release of a CO ligand. X-ray diffraction, IR and NMR spectroscopy, and calculations of minimum-energy structures by DFT methods were used to

  7. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  8. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  9. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  10. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  11. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  12. Ab initio calculations of scytonemin derivatives of relevance to extremophile characterization by Raman spectroscopy.

    PubMed

    Varnali, Tereza; Edwards, Howell G M

    2010-07-13

    The recognition that scytonemin, the radiation protectant pigment produced by extremophilic cyanobacterial colonies in stressed terrestrial environments, is a key biomarker for extinct or extant life preserved in geological scenarios is critically important for the detection of life signatures by remote analytical instrumentation on planetary surfaces and subsurfaces. The ExoMars mission to seek life signatures on Mars is just one experiment that will rely upon the detection of molecules such as scytonemin in the Martian regolith. Following a detailed structural analysis of the parent scytonemin, we report here for the first time a similar analysis of several of its methoxy derivatives that have recently been extracted from stressed cyanobacteria. Ab initio calculations have been carried out to determine the most stable molecular configurations, and the implications of the structural changes imposed by the methoxy group additions on the spectral characteristics of the parent molecule are discussed. The calculated electronic absorption bands of the derivative molecules reveal that their capability of removing UVA wavelengths is removed while preserving the ability to absorb the shorter wavelength UVB and UVC radiation, in contrast to scytonemin itself. This is indicative of a special role for these molecules in the protective strategy of the cyanobacterial extremophiles. PMID:20529954

  13. Adamantane derivatives of sulfonamides: sublimation, solubility, solvation and transfer processes in biologically relevant solvents.

    PubMed

    Perlovich, G L; Volkova, T V; Sharapova, A V; Kazachenko, V P; Strakhova, N N; Proshin, A N

    2016-04-01

    Eight adamantane derivatives of sulfonamides were synthesized and characterized. Temperature dependencies of saturation vapor pressure were obtained using the transpiration method and thermodynamic functions of the sublimation processes were calculated. Solubility values of the selected compounds in buffer (pH 7.4), 1-octanol and 1-hexane were determined at different temperatures using the isothermal saturation method. Thermophysical characteristics of fusion processes (melting points and fusion enthalpies) of the substances were studied using the DSC method. Transfer processes from buffer to 1-octanol, from buffer to 1-hexane and 1-hexane to 1-octanol were analyzed. The impact of the molecules' structural modification on sublimation, solubility and solvation/hydration processes in the solvents was studied. Correlation equations connecting the thermodynamic functions with physicochemical descriptors were obtained. PMID:26976747

  14. Plasma distribution of tetraphenylporphyrin derivatives relevant for Photodynamic Therapy: importance and limits of hydrophobicity.

    PubMed

    Chauvin, Benoît; Iorga, Bogdan I; Chaminade, Pierre; Paul, Jean-Louis; Maillard, Philippe; Prognon, Patrice; Kasselouri, Athena

    2013-02-01

    In the course of a Photodynamic Therapy (PDT) protocol, disaggregation of the sensitizer upon binding to plasma proteins and lipoproteins is one of the first steps following intravenous administration. This step governs its subsequent biodistribution and has even been evoked as possibly orientating mechanism of tumor destruction. It is currently admitted as being mainly dependent on sensitizer's hydrophobicity. In this context, as far as glycoconjugation of meso-tetraphenylporphyrin (TPP) macrocycle, a promising strategy to improve targeting of retinoblastoma cells confers to the sensitizer an amphiphilic character, we have studied the effect of this strategy on binding to plasma proteins and lipoproteins. With the exception of the majoritary protein binding (more than 80%) of more hydrophilic para-tetraglycoconjugated derivatives, high density lipoproteins (HDL) appear as main plasma carriers of the other amphiphilic glycoconjugated photosensitizers. This HDL-binding is a combined result of binding affinities (logKa ranging from 4.90 to 8.77 depending on the carrier and the TPP derivative considered) and relative plasma concentrations of the different carriers. Evaluation of binding affinities shows that if hydrophobicity can account for LDL- and HDL-affinities, it is not the case for albumin-affinity. Molecular docking simulations show that, if interactions are mainly of hydrophobic nature, polar interactions such as hydrogen bonds are also involved. This combination of interaction modalities should account for the absence of clear relationship between albumin-affinity and hydrophobicity. Taken together, our findings clarify the importance, but also the limits, of hydrophobicity's role in structure-plasma distribution relationship. PMID:23089311

  15. The pharmacology and therapeutic relevance of endocannabinoid derived cyclo-oxygenase (COX)-2 products.

    PubMed

    Woodward, D F; Carling, R W C; Cornell, C L; Fliri, H G; Martos, J L; Pettit, S N; Liang, Y; Wang, J W

    2008-10-01

    The discovery of anandamide and 2-arachidonyl glycerol (2-AG) as naturally occurring mammalian endocannabinoids has had important and wide-reaching therapeutic implications. This, to a large extent, ensues from the complexity of endocannabinoid biology. One facet of endocannabinoid biology now receiving increased attention is the cyclo-oxygenase-2 (COX-2) derived oxidation products. Anandamide and 2-AG are oxidized to a range of PG-ethanolamides and PG-glyceryl esters that closely approaches that of the prostaglandins (PGs) formed from arachidonic acid. The pharmacology of these electrochemically neutral PG-ethanolamides (prostamides) and PG-glyceryl esters appears to be unique. No meaningful interaction with natural or recombinant prostanoid receptors is apparent. Nevertheless, in certain cells and tissues, prostamides and PG-glyceryl esters exert potent effects. The recent discovery of selective antagonists for the putative prostamide receptor has been a major advance in further establishing prostamide pharmacology as an entity distinct from prostanoid receptors. Since discovery of the prototype prostamide antagonist (AGN 204396), rapid progress has been made. The latest prostamide antagonists (AGN 211334-6) are 100 times more potent than the prototype and are, therefore, sufficiently active to be used in living animal studies. These compounds will allow a full evaluation of the role of prostamides in health and disease. To date, the only therapeutic application for prostamides is in glaucoma. The prostamide analog, bimatoprost, being the most effective ocular hypotensive drug currently available. Interestingly, PGE(2)-glyceryl ester and its chemically stable analog PGE(2)-serinolamide also lower intraocular pressure in dogs. Nevertheless, the therapeutic future of PGE(2)-glyceryl ester is more likely to reside in inflammation. PMID:18700152

  16. Fluorescence labeling of carbonylated lipids and proteins in cells using coumarin-hydrazide

    PubMed Central

    Vemula, Venukumar; Ni, Zhixu; Fedorova, Maria

    2015-01-01

    Carbonylation is a generic term which refers to reactive carbonyl groups present in biomolecules due to oxidative reactions induced by reactive oxygen species. Carbonylated proteins, lipids and nucleic acids have been intensively studied and often associated with onset or progression of oxidative stress related disorders. In order to reveal underlying carbonylation pathways and biological relevance, it is crucial to study their intracellular formation and spatial distribution. Carbonylated species are usually identified and quantified in cell lysates and body fluids after derivatization using specific chemical probes. However, spatial cellular and tissue distribution have been less often investigated. Here, we report coumarin-hydrazide, a fluorescent chemical probe for time- and cost-efficient labeling of cellular carbonyls followed by fluorescence microscopy to evaluate their intracellular formation both in time and space. The specificity of coumarin-hydrazide was confirmed in time- and dose-dependent experiments using human primary fibroblasts stressed with paraquat and compared with conventional DNPH-based immunocytochemistry. Both techniques stained carbonylated species accumulated in cytoplasm with strong perinuclear clustering. Using a complimentary array of analytical methods specificity of coumarin-hydrazide probe towards both protein- and lipid-bound carbonyls has been shown. Additionally, co-distribution of carbonylated species and oxidized phospholipids was demonstrated. PMID:25974625

  17. Proposal for defining the relevance of drug accumulation derived from single dose study data for modified release dosage forms.

    PubMed

    Scheerans, Christian; Heinig, Roland; Mueck, Wolfgang

    2015-03-01

    Recently, the European Medicines Agency (EMA) published the new draft guideline on the pharmacokinetic and clinical evaluation of modified release (MR) formulations. The draft guideline contains the new requirement of performing multiple dose (MD) bioequivalence studies, in the case when the MR formulation is expected to show 'relevant' drug accumulation at steady state (SS). This new requirement reveals three fundamental issues, which are discussed in the current work: first, measurement for the extent of drug accumulation (MEDA) predicted from single dose (SD) study data; second, its relationship with the percentage residual area under the plasma concentration-time curve (AUC) outside the dosing interval (τ) after SD administration, %AUC(τ-∞)SD ; and third, the rationale for a threshold of %AUC(τ-∞)SD that predicts 'relevant' drug accumulation at SS. This work revealed that the accumulation ratio RA,AUC , derived from the ratio of the time-averaged plasma concentrations during τ at SS and after SD administration, respectively, is the 'preferred' MEDA for MR formulations. A causal relationship was derived between %AUC(τ-∞)SD and RA,AUC , which is valid for any drug (product) that shows (dose- and time-) linear pharmacokinetics regardless of the shape of the plasma concentration-time curve. Considering AUC thresholds from other guidelines together with the causal relationship between %AUC(τ-∞)SD and RA,AUC indicates that values of %AUC(τ-∞)SD ≤ 20%, resulting in RA,AUC ≤ 1.25, can be considered as leading to non-relevant drug accumulation. Hence, the authors suggest that 20% for %AUC(τ-∞)SD is a reasonable threshold and selection criterion between SD or MD study designs for bioequivalence studies of new MR formulations. PMID:25327367

  18. Determination of toxic carbonyl compounds in cigarette smoke.

    PubMed

    Fujioka, Kazutoshi; Shibamoto, Takayuki

    2006-02-01

    Toxic carbonyl compounds, including formaldehyde, malonaldehyde, and glyoxal, formed in mainstream cigarette smoke were quantified by derivatization-solid phase extraction-gas chromatography methods. Cigarette smoke from 14 commercial brands and one reference (2R1F) was drawn into a separatory funnel containing aqueous phosphate-buffered saline. Reactive carbonyl compounds trapped in the buffer solution were derivatized into stable nitrogen containing compounds (pyrazoles for beta-dicarbonyl and alpha,beta-unsaturated aldehyde; quinoxalines for alpha-dicarbonyls; and thiazolidines for alkanals). After derivatives were recovered using C(18) solid phase extraction cartridges, they were analyzed quantitatively by a gas chromatograph with a nitrogen phosphorus detector. The total carbonyl compounds recovered from regular size cigarettes ranged from 1.92 mg/cigarette(-1) to 3.14 mg/cigarette(-1). The total carbonyl compounds recovered from a reference cigarette and a king size cigarette were 3.23 mg/cigarette(-1) and 3.39 mg/cigarette(-1), respectively. The general decreasing order of the carbonyl compounds yielded was acetaldehyde (1110-2101 microg/cigarette(-1)) > diacetyl (301-433 microg/cigarette(-1)), acrolein (238-468 microg/cigarette(-1)) > formaldehyde (87.0-243 microg/cigarette(-1)), propanal (87.0-176 microg/cigarette(-1)) > malonaldehyde (18.9-36.0 microg/cigarette(-1)), methylglyoxal (13.4-59.6 microg/cigarette(-1)) > glyoxal (1.93-6.98 microg/cigarette(-1)). PMID:16463255

  19. Traditional reactive carbonyl scavengers do not prevent the carbonylation of brain proteins induced by acute glutathione depletion.

    PubMed

    Zheng, J; Bizzozero, O A

    2010-03-01

    This study investigated the effect of reactive carbonyl species (RCS)-trapping agents on the formation of protein carbonyls during depletion of brain glutathione (GSH). To this end, rat brain slices were incubated with the GSH-depletor diethyl maleate in the absence or presence of chemically different RCS scavengers (hydralazine, methoxylamine, aminoguanidine, pyridoxamine, carnosine, taurine and z-histidine hydrazide). Despite their strong reactivity towards the most common RCS, none of the scavengers tested, with the exception of hydralazine, prevented protein carbonylation. These findings suggest that the majority of protein-associated carbonyl groups in this oxidative stress paradigm do not derive from stable lipid peroxidation products like malondialdehyde (MDA), acrolein and 4-hydroxynonenal (4-HNE). This conclusion was confirmed by the observation that the amount of MDA-, acrolein- and 4-HNE-protein adducts does not increase upon GSH depletion. Additional studies revealed that the efficacy of hydralazine at preventing carbonylation was due to its ability to reduce oxidative stress, most likely by inhibiting mitochondrial production of superoxide and/or by scavenging lipid free radicals. PMID:20001647

  20. Carbonylation reactions of alkyl iodides through the interplay of carbon radicals and Pd catalysts.

    PubMed

    Sumino, Shuhei; Fusano, Akira; Fukuyama, Takahide; Ryu, Ilhyong

    2014-05-20

    Numerous methods for transition metal catalyzed carbonylation reactions have been established. Examples that start from aryl, vinyl, allyl, and benzyl halides to give the corresponding carboxylic acid derivatives have all been well documented. In contrast, the corresponding alkyl halides often encounter difficulty. This is inherent to the relatively slow oxidative addition step onto the metal center and subsequent β-hydride elimination which causes isomerization of the alkyl metal species. Radical carbonylation reactions can override such problems of reactivity; however, carbonylation coupled to iodine atom transfer (atom transfer carbonylation), though useful, often suffers from a slow iodine atom transfer step that affects the outcome of the reaction. We found that atom transfer carbonylation of primary, secondary, and tertiary alkyl iodides was efficiently accelerated by the addition of a palladium catalyst under light irradiation. Stereochemical studies support a mechanistic pathway based on the synergic interplay of radical and Pd-catalyzed reaction steps which ultimately lead to an acylpalladium species. The radical/Pd-combined reaction system has a wide range of applications, including the synthesis of carboxylic acid esters, lactones, amides, lactams, and unsymmetrical ketones such as alkyl alkynyl and alkyl aryl ketones. The design of unique multicomponent carbonylation reactions involving vicinal C-functionalization of alkenes, double and triple carbonylation reactions, in tandem with radical cyclization reactions, has also been achieved. Thus, the radical/Pd-combined strategy provides a solution to a longstanding problem of reactivity involving the carbonylation of alkyl halides. This novel methodology expands the breadth and utility of carbonylation chemistry over either the original radical carbonylation reactions or metal-catalyzed carbonylation reactions. PMID:24712759

  1. A step-by-step protocol for assaying protein carbonylation in biological samples.

    PubMed

    Colombo, Graziano; Clerici, Marco; Garavaglia, Maria Elisa; Giustarini, Daniela; Rossi, Ranieri; Milzani, Aldo; Dalle-Donne, Isabella

    2016-04-15

    Protein carbonylation represents the most frequent and usually irreversible oxidative modification affecting proteins. This modification is chemically stable and this feature is particularly important for storage and detection of carbonylated proteins. Many biochemical and analytical methods have been developed during the last thirty years to assay protein carbonylation. The most successful method consists on protein carbonyl (PCO) derivatization with 2,4-dinitrophenylhydrazine (DNPH) and consequent spectrophotometric assay. This assay allows a global quantification of PCO content due to the ability of DNPH to react with carbonyl giving rise to an adduct able to absorb at 366 nm. Similar approaches were also developed employing chromatographic separation, in particular HPLC, and parallel detection of absorbing adducts. Subsequently, immunological techniques, such as Western immunoblot or ELISA, have been developed leading to an increase of sensitivity in protein carbonylation detection. Currently, they are widely employed to evaluate change in total protein carbonylation and eventually to highlight the specific proteins undergoing selective oxidation. In the last decade, many mass spectrometry (MS) approaches have been developed for the identification of the carbonylated proteins and the relative amino acid residues modified to carbonyl derivatives. Although these MS methods are much more focused and detailed due to their ability to identify the amino acid residues undergoing carbonylation, they still require too expensive equipments and, therefore, are limited in distribution. In this protocol paper, we summarise and comment on the most diffuse protocols that a standard laboratory can employ to assess protein carbonylation; in particular, we describe step-by-step the different protocols, adding suggestions coming from our on-bench experience. PMID:26706659

  2. Proposal for defining the relevance of drug accumulation derived from single dose study data for modified release dosage forms

    PubMed Central

    Scheerans, Christian; Heinig, Roland; Mueck, Wolfgang

    2015-01-01

    Recently, the European Medicines Agency (EMA) published the new draft guideline on the pharmacokinetic and clinical evaluation of modified release (MR) formulations. The draft guideline contains the new requirement of performing multiple dose (MD) bioequivalence studies, in the case when the MR formulation is expected to show ‘relevant’ drug accumulation at steady state (SS). This new requirement reveals three fundamental issues, which are discussed in the current work: first, measurement for the extent of drug accumulation (MEDA) predicted from single dose (SD) study data; second, its relationship with the percentage residual area under the plasma concentration–time curve (AUC) outside the dosing interval (τ) after SD administration, %AUC(τ-∞)SD; and third, the rationale for a threshold of %AUC(τ-∞)SD that predicts ‘relevant’ drug accumulation at SS. This work revealed that the accumulation ratio RA,AUC, derived from the ratio of the time-averaged plasma concentrations during τ at SS and after SD administration, respectively, is the ‘preferred’ MEDA for MR formulations. A causal relationship was derived between %AUC(τ-∞)SD and RA,AUC, which is valid for any drug (product) that shows (dose- and time-) linear pharmacokinetics regardless of the shape of the plasma concentration–time curve. Considering AUC thresholds from other guidelines together with the causal relationship between %AUC(τ-∞)SD and RA,AUC indicates that values of %AUC(τ-∞)SD ≤ 20%, resulting in RA,AUC ≤ 1.25, can be considered as leading to non-relevant drug accumulation. Hence, the authors suggest that 20% for %AUC(τ-∞)SD is a reasonable threshold and selection criterion between SD or MD study designs for bioequivalence studies of new MR formulations. © 2014 The Authors Biopharmaceutics & Drug Disposition Published by John Wiley & Sons Ltd. PMID:25327367

  3. Protein carbonylation during natural leaf senescence in winter wheat, as probed by fluorescein-5-thiosemicarbazide.

    PubMed

    Havé, M; Leitao, L; Bagard, M; Castell, J-F; Repellin, A

    2015-09-01

    Leaf senescence is characterised by a massive degradation of proteins in order to recycle nitrogen to other parts of the plant, such as younger leaves or developing grain/seed. Protein degradation during leaf senescence is a highly regulated process and it is suggested that proteins to be degraded are marked by an oxidative modification (carbonylation) that makes them more susceptible to proteolysis. However, there is as yet no evidence of an increase in protein carbonylation level during natural leaf senescence. The aim of our study was thus to monitor protein carbonylation level during the process of natural senescence in the flag leaf of field-grown winter wheat plants. For this purpose, we adapted a fluorescence-based method using fluorescein-5-thiosemicarbazide (FTC) as a probe for detecting protein carbonyl derivatives. As used for the first time on plant material, this method allowed the detection of both quantitative and qualitative modifications in protein carbonyl levels during the last stages of wheat flag leaf development. The method described herein represents a convenient, sensitive and reproducible alternative to the commonly used 2,4-dinitrophenylhydrazine (DNPH)-based method. In addition, our analysis revealed changes in protein carbonylation level during leaf development that were associated with qualitative changes in protein abundance and carbonylation profiles. In the senescing flag leaf, protein carbonylation increased concomitantly with a stimulation of endoproteolytic activity and a decrease in protein content, which supports the suggested relationship between protein oxidation and proteolysis during natural leaf senescence. PMID:25683278

  4. AminoxyTMT: A novel multi-functional reagent for characterization of protein carbonylation.

    PubMed

    Afiuni-Zadeh, Somaieh; Rogers, John C; Snovida, Sergei I; Bomgarden, Ryan D; Griffin, Timothy J

    2016-01-01

    Protein carbonylation is a common oxidative stress (OS)-driven post-translational modification (PTM). Proteome-wide carbonylation events can best be characterized using a combination of analytical approaches. Immunoblotting of carbonylated proteins provides data on the extent of modifications within complex samples, as well as a broad comparison of carbonylation profiles between different biological states (e.g., disease versus control), while mass spectrometry (MS)-based analysis provides information on proteins susceptible to carbonylation, as well as the potential for quantitative characterization of specific sites of amino acid modification. Here, we present a novel use for aminoxyTMT, a derivative of the Tandem Mass Tag (TMT) isobaric labeling reagent, which utilizes an aminooxy functional group for covalent labeling of reactive carbonyls in proteins. When coupled with anti-TMT antibody, we demonstrate the use of aminoxyTMT for immunoblot profiling of protein carbonylation in complex mixtures, as well as enrichment of modified peptides from these mixtures. Proof-of-principle experiments also show the amenability of aminoxyTMT-labeled carbonylated peptides enriched from complex mixtures to identification using tandem MS (MS/MS) and database searching, as well as quantitative analysis using TMT-based reporter ion intensity measurements. PMID:27071607

  5. Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (PHB) from a Process Relevant Lignocellulosic Derived Sugar (Poster)

    SciTech Connect

    Wang, W.; Mittal, A.; Mohagheghi, A.; Johnson, D. K.

    2014-04-01

    PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. Cupriavidus necator is the microorganism that has been most extensively studied and used for PHB production on an industrial scale; However the substrates used for producing PHB are mainly fructose, glucose, sucrose, fatty acids, glycerol, etc., which are expensive. In this study, we demonstrate production of PHB from a process relevant lignocellulosic derived sugar stream, i.e., saccharified slurry from pretreated corn stover. The strain was first investigated in shake flasks for its ability to utilize glucose, xylose and acetate. In addition, the strain was also grown on pretreated lignocellulose hydrolyzate slurry and evaluated in terms of cell growth, sugar utilization, PHB accumulation, etc. The mechanism of inhibition in the toxic hydrolysate generated by the pretreatment and saccharification process of biomass, was also studied.

  6. Inhibition of Human Aldehyde Oxidase Activity by Diet-Derived Constituents: Structural Influence, Enzyme-Ligand Interactions, and Clinical Relevance

    PubMed Central

    Barr, John T.; Jones, Jeffrey P.; Oberlies, Nicholas H.

    2015-01-01

    The mechanistic understanding of interactions between diet-derived substances and conventional medications in humans is nascent. Most investigations have examined cytochrome P450–mediated interactions. Interactions mediated by other phase I enzymes are understudied. Aldehyde oxidase (AO) is a phase I hydroxylase that is gaining recognition in drug design and development programs. Taken together, a panel of structurally diverse phytoconstituents (n = 24) was screened for inhibitors of the AO-mediated oxidation of the probe substrate O6-benzylguanine. Based on the estimated IC50 (<100 μM), 17 constituents were advanced for Ki determination. Three constituents were described best by a competitive inhibition model, whereas 14 constituents were described best by a mixed-mode model. The latter model consists of two Ki terms, Kis and Kii, which ranged from 0.26–73 and 0.80–120 μM, respectively. Molecular modeling was used to glean mechanistic insight into AO inhibition. Docking studies indicated that the tested constituents bound within the AO active site and elucidated key enzyme-inhibitor interactions. Quantitative structure-activity relationship modeling identified three structural descriptors that correlated with inhibition potency (r2 = 0.85), providing a framework for developing in silico models to predict the AO inhibitory activity of a xenobiotic based solely on chemical structure. Finally, a simple static model was used to assess potential clinically relevant AO-mediated dietary substance–drug interactions. Epicatechin gallate and epigallocatechin gallate, prominent constituents in green tea, were predicted to have moderate to high risk. Further characterization of this uncharted type of interaction is warranted, including dynamic modeling and, potentially, clinical evaluation. PMID:25326286

  7. Inhibition of human aldehyde oxidase activity by diet-derived constituents: structural influence, enzyme-ligand interactions, and clinical relevance.

    PubMed

    Barr, John T; Jones, Jeffrey P; Oberlies, Nicholas H; Paine, Mary F

    2015-01-01

    The mechanistic understanding of interactions between diet-derived substances and conventional medications in humans is nascent. Most investigations have examined cytochrome P450-mediated interactions. Interactions mediated by other phase I enzymes are understudied. Aldehyde oxidase (AO) is a phase I hydroxylase that is gaining recognition in drug design and development programs. Taken together, a panel of structurally diverse phytoconstituents (n = 24) was screened for inhibitors of the AO-mediated oxidation of the probe substrate O(6)-benzylguanine. Based on the estimated IC50 (<100 μM), 17 constituents were advanced for Ki determination. Three constituents were described best by a competitive inhibition model, whereas 14 constituents were described best by a mixed-mode model. The latter model consists of two Ki terms, Kis and Kii, which ranged from 0.26-73 and 0.80-120 μM, respectively. Molecular modeling was used to glean mechanistic insight into AO inhibition. Docking studies indicated that the tested constituents bound within the AO active site and elucidated key enzyme-inhibitor interactions. Quantitative structure-activity relationship modeling identified three structural descriptors that correlated with inhibition potency (r(2) = 0.85), providing a framework for developing in silico models to predict the AO inhibitory activity of a xenobiotic based solely on chemical structure. Finally, a simple static model was used to assess potential clinically relevant AO-mediated dietary substance-drug interactions. Epicatechin gallate and epigallocatechin gallate, prominent constituents in green tea, were predicted to have moderate to high risk. Further characterization of this uncharted type of interaction is warranted, including dynamic modeling and, potentially, clinical evaluation. PMID:25326286

  8. Vibrational scaling factors for transition metal carbonyls

    NASA Astrophysics Data System (ADS)

    Assefa, M. K.; Devera, J. L.; Brathwaite, A. D.; Mosley, J. D.; Duncan, M. A.

    2015-11-01

    Vibrational frequencies for a selected set of transition metal carbonyl complexes are computed with various forms of density functional theory (B3LYP, BP86, M06, and M06-L), employing several different basis sets. The computed frequencies for the carbonyl stretches are compared to the experimental values obtained from gas phase infrared spectra of isolated neutrals and ions. Recommended carbonyl-stretch scaling factors which are developed vary significantly for different functionals, but there is little variation with basis set. Scaled frequencies compared to experimental spectra for cobalt and tantalum carbonyl cations reveal additional variations in multiplet patterns and relative band intensities for different functionals.

  9. Crystal structures of four indole derivatives with a phenyl substituent at the 2-position and a carbonyl group at the 3-position: the C(6) N—H⋯O chain remains the same, but the weak reinforcing inter­actions are different

    PubMed Central

    Kerr, Jamie R.; Trembleau, Laurent; Storey, John M. D.; Wardell, James L.; Harrison, William T. A.

    2016-01-01

    We describe the crystal structures of four indole derivatives with a phenyl ring at the 2-position and different carbonyl-linked substituents at the 3-position, namely 1-(2-phenyl-1H-indol-3-yl)ethanone, C16H13NO, (I), 2-cyclo­hexyl-1-(2-phenyl-1H-indol-3-yl)ethanone, C22H23NO, (II), 3,3-dimethyl-1-(2-phenyl-1H-indol-3-yl)butan-1-one, C20H21NO, (III), and 3-benzoyl-2-phenyl-1H-indole, C21H15NO, (IV). In each case, the carbonyl-group O atom lies close to the indole-ring plane and points towards the benzene ring. The dihedral angles between the indole ring system and 2-phenyl ring for these structures are clustered in a narrow range around 65°. The dominant inter­molecular inter­action in each case is an N—H⋯O hydrogen bond, which generates a C(6) chain, although each structure possesses a different crystal symmetry. The C(6) chains are consolidated by different (C—H⋯O, C—H⋯π and π–π stacking) weak inter­actions, with little consistency between the structures. PMID:27006809

  10. Fourier Transform Vibrational Circular Dichroism Of Carbonyl Stretching Modes In N-urethanyl-a-amino acids

    NASA Astrophysics Data System (ADS)

    Chernovitz, Anita C.; Freedman, Teresa B.; Nafie, Laurence A.

    1985-12-01

    The vibrational circular dichroism (VCD) spectra of the N-t-BOC and N-CBZ-derivatives of alanine, proline, phenylalanine and valine in 0.2M CHC13 solutions all exhibit a characteristic, strong bisignate couplet in the carbonyl stretching region. The VCD couplet is interpreted in terms of the coupled oscillation of the urethane and acid carbonyl groups in an intramolecularly hydrogen-bonded structure.

  11. Increased Adipose Protein Carbonylation in Human Obesity

    PubMed Central

    Frohnert, Brigitte I.; Sinaiko, Alan R.; Serrot, Federico J.; Foncea, Rocio E.; Moran, Antoinette; Ikramuddin, Sayeed; Choudry, Umar; Bernlohr, David A.

    2015-01-01

    Insulin resistance is associated with obesity but mechanisms controlling this relationship in humans are not fully understood. Studies in animal models suggest a linkage between adipose reactive oxygen species (ROS) and insulin resistance. ROS oxidize cellular lipids to produce a variety of lipid hydroperoxides that in turn generate reactive lipid aldehydes that covalently modify cellular proteins in a process termed carbonylation. Mammalian cells defend against reactive lipid aldehydes and protein carbonylation by glutathionylation using glutathione-S-transferase A4 (GSTA4) or carbonyl reduction/oxidation via reductases and/or dehydrogenases. Insulin resistance in mice is linked to ROS production and increased level of protein carbonylation, mitochondrial dysfunction, decreased insulin-stimulated glucose transport, and altered adipokine secretion. To assess protein carbonylation and insulin resistance in humans, eight healthy participants underwent subcutaneous fat biopsy from the periumbilical region for protein analysis and frequently sampled intravenous glucose tolerance testing to measure insulin sensitivity. Soluble proteins from adipose tissue were analyzed using two-dimensional gel electrophoresis and the major carbonylated proteins identified as the adipocyte and epithelial fatty acid–binding proteins. The level of protein carbonylation was directly correlated with adiposity and serum free fatty acids (FFAs). These results suggest that in human obesity oxidative stress is linked to protein carbonylation and such events may contribute to the development of insulin resistance. PMID:21593812

  12. Surface decorated platinum carbonyl clusters

    NASA Astrophysics Data System (ADS)

    Ciabatti, Iacopo; Femoni, Cristina; Iapalucci, Maria Carmela; Longoni, Giuliano; Zacchini, Stefano; Zarra, Salvatore

    2012-06-01

    Four molecular Pt-carbonyl clusters decorated by Cd-Br fragments, i.e., [Pt13(CO)12{Cd5(μ-Br)5Br2(dmf)3}2]2- (1), [Pt19(CO)17{Cd5(μ-Br)5Br3(Me2CO)2}{Cd5(μ-Br)5Br(Me2CO)4}]2- (2), [H2Pt26(CO)20(CdBr)12]8- (3) and [H4Pt26(CO)20(CdBr)12(PtBr)x]6- (4) (x = 0-2), have been obtained from the reactions between [Pt3n(CO)6n]2- (n = 2-6) and CdBr2.H2O in dmf at 120 °C. The structures of these molecular clusters with diameters of 1.5-2 nm have been determined by X-ray crystallography. Both 1 and 2 are composed of icosahedral or bis-icosahedral Pt-CO cores decorated on the surface by Cd-Br motifs, whereas 3 and 4 display a cubic close packed Pt26Cd12 metal frame decorated by CO and Br ligands. An oversimplified and unifying approach to interpret the electron count of these surface decorated platinum carbonyl clusters is suggested, and extended to other low-valent organometallic clusters and Au-thiolate nanoclusters.Four molecular Pt-carbonyl clusters decorated by Cd-Br fragments, i.e., [Pt13(CO)12{Cd5(μ-Br)5Br2(dmf)3}2]2- (1), [Pt19(CO)17{Cd5(μ-Br)5Br3(Me2CO)2}{Cd5(μ-Br)5Br(Me2CO)4}]2- (2), [H2Pt26(CO)20(CdBr)12]8- (3) and [H4Pt26(CO)20(CdBr)12(PtBr)x]6- (4) (x = 0-2), have been obtained from the reactions between [Pt3n(CO)6n]2- (n = 2-6) and CdBr2.H2O in dmf at 120 °C. The structures of these molecular clusters with diameters of 1.5-2 nm have been determined by X-ray crystallography. Both 1 and 2 are composed of icosahedral or bis-icosahedral Pt-CO cores decorated on the surface by Cd-Br motifs, whereas 3 and 4 display a cubic close packed Pt26Cd12 metal frame decorated by CO and Br ligands. An oversimplified and unifying approach to interpret the electron count of these surface decorated platinum carbonyl clusters is suggested, and extended to other low-valent organometallic clusters and Au-thiolate nanoclusters. CCDC 867747 and 867748. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c2nr30400g

  13. Carbonyl sulfide (OCS) as a proxy for GPP: Complications derived from studies on the impact of CO2, soil humidity and sterilization on the OCS exchange between soils and atmosphere

    NASA Astrophysics Data System (ADS)

    Bunk, Rüdiger; Behrendt, Thomas; Yi, Zhigang; Kesselmeier, Jürgen

    2016-04-01

    Carbonyl sulfide is discussed to be used as a proxy for gross primary productivity (GPP) of forest ecosystems. However, soils may interfere. Soils play an important role in budgeting global and local carbonyl sulfide (OCS) fluxes, yet the available data on the uptake and emission behavior of soils in conjunction with environmental factors is limited. The work of many authors has shown that the OCS exchange of soils depends on various factors, such as soil type, atmospheric OCS concentrations, temperature or soil water content (Kesselmeier et al., J. Geophys. Res., 104, No. D9, 11577-11584, 1999; Van Diest & Kesselmeier, Biogeosciences, 5, 475-483, 2008; Masyek et al., PNAS, 111, No 25, 9064-9069, doi: 10.1073/pnas.1319132111, 2014; Whelan and Rhew, J. Geophys. Res. Biogeosciences., 120, 54-62, doi: 10.1002/2014JG002661, 2015) and the light dependent and obviously abiotic OCS production as reported by Whelan and Rhew (2015). To get a better constraint on the impact of some environmental factors on the OCS exchange of soils we used a new laser based integrated cavity output spectroscopy instrument (LGR COS/CO Analyzer Model 907-0028, Los Gatos, Mountain View, California, USA) in conjunction with an automated soil chamber system (as described in Behrendt et al, Biogeosciences, 11, 5463-5492, doi: 10.5194/bg-11-5463-2014, 2014). The OCS exchange of various soils under the full range of possible soil humidity and various CO2 mixing ratios was examined. Additionally OCS exchange of chloroform sterilized subsamples was compared to their live counterparts to illuminate the influence of microorganisms. Results were quite heterogeneous between different soils. With few exceptions, all examined soils show dependence between OCS exchange and soil humidity, usually with strongest uptake at a certain humidity range and less uptake or even emission at higher and lower humidity. Differences in CO2 mixing ratio also clearly impacts on OCS exchange, but trends for different soils

  14. Development of a test method for carbonyl compounds from stationary source emissions

    SciTech Connect

    Zhihua Fan; Peterson, M.R.; Jayanty, R.K.M.

    1997-12-31

    Carbonyl compounds have received increasing attention because of their important role in ground-level ozone formation. The common method used for the measurement of aldehydes and ketones is 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by high performance liquid chromatography and ultra violet (HPLC-UV) analysis. One of the problems associated with this method is the low recovery for certain compounds such as acrolein. This paper presents a study in the development of a test method for the collection and measurement of carbonyl compounds from stationary source emissions. This method involves collection of carbonyl compounds in impingers, conversion of carbonyl compounds to a stable derivative with O-2,3,4,5,6-pentafluorobenzyl hydroxylamine hydrochloride (PFBHA), and separation and measurement by electron capture gas chromatography (GC-ECD). Eight compounds were selected for the evaluation of this method: formaldehyde, acetaldehyde, acrolein, acetone, butanal, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and hexanal.

  15. Iron(III)-catalysed carbonyl-olefin metathesis.

    PubMed

    Ludwig, Jacob R; Zimmerman, Paul M; Gianino, Joseph B; Schindler, Corinna S

    2016-05-19

    The olefin metathesis reaction of two unsaturated substrates is one of the most powerful carbon-carbon-bond-forming reactions in organic chemistry. Specifically, the catalytic olefin metathesis reaction has led to profound developments in the synthesis of molecules relevant to the petroleum, materials, agricultural and pharmaceutical industries. These reactions are characterized by their use of discrete metal alkylidene catalysts that operate via a well-established mechanism. While the corresponding carbonyl-olefin metathesis reaction can also be used to construct carbon-carbon bonds, currently available methods are scarce and severely hampered by either harsh reaction conditions or the required use of stoichiometric transition metals as reagents. To date, no general protocol for catalytic carbonyl-olefin metathesis has been reported. Here we demonstrate a catalytic carbonyl-olefin ring-closing metathesis reaction that uses iron, an Earth-abundant and environmentally benign transition metal, as a catalyst. This transformation accommodates a variety of substrates and is distinguished by its operational simplicity, mild reaction conditions, high functional-group tolerance, and amenability to gram-scale synthesis. We anticipate that these characteristics, coupled with the efficiency of this reaction, will allow for further advances in areas that have historically been enhanced by olefin metathesis. PMID:27120158

  16. Are Alphabetic Language-Derived Models of L2 Reading Relevant to L1 Logographic Background Readers?

    ERIC Educational Resources Information Center

    Ehrich, John Fitzgerald; Zhang, Lawrence Jun; Mu, Jon Congjun; Ehrich, Lisa Catherine

    2013-01-01

    In this paper, we argue that second language (L2) reading research, which has been informed by studies involving first language (L1) alphabetic English reading, may be less relevant to L2 readers with non-alphabetic reading backgrounds, such as Chinese readers with an L1 logographic (Chinese character) learning history. We provide both…

  17. CarSPred: a computational tool for predicting carbonylation sites of human proteins.

    PubMed

    Lv, Hongqiang; Han, Jiuqiang; Liu, Jun; Zheng, Jiguang; Liu, Ruiling; Zhong, Dexing

    2014-01-01

    Protein carbonylation is one of the most pervasive oxidative stress-induced post-translational modifications (PTMs), which plays a significant role in the etiology and progression of several human diseases. It has been regarded as a biomarker of oxidative stress due to its relatively early formation and stability compared with other oxidative PTMs. Only a subset of proteins is prone to carbonylation and most carbonyl groups are formed from lysine (K), arginine (R), threonine (T) and proline (P) residues. Recent advancements in analysis of the PTM by mass spectrometry provided new insights into the mechanisms of protein carbonylation, such as protein susceptibility and exact modification sites. However, the experimental approaches to identifying carbonylation sites are costly, time-consuming and capable of processing a limited number of proteins, and there is no bioinformatics method or tool devoted to predicting carbonylation sites of human proteins so far. In the paper, a computational method is proposed to identify carbonylation sites of human proteins. The method extracted four kinds of features and combined the minimum Redundancy Maximum Relevance (mRMR) feature selection criterion with weighted support vector machine (WSVM) to achieve total accuracies of 85.72%, 85.95%, 83.92% and 85.72% for K, R, T and P carbonylation site predictions respectively using 10-fold cross-validation. The final optimal feature sets were analysed, the position-specific composition and hydrophobicity environment of flanking residues of modification sites were discussed. In addition, a software tool named CarSPred has been developed to facilitate the application of the method. Datasets and the software involved in the paper are available at https://sourceforge.net/projects/hqlstudio/files/CarSPred-1.0/. PMID:25347395

  18. Fluorimetric screening assay for protein carbonyl evaluation in biological samples.

    PubMed

    Stocker, P; Ricquebourg, E; Vidal, N; Villard, C; Lafitte, D; Sellami, L; Pietri, S

    2015-08-01

    Many assays are available for the detection of protein carbonyls (PCs). Currently, the measurement of PC groups after their derivatization with 2,4-dinitrophenol hydrazine (DNPH) is widely used for measuring protein oxidation in biological samples. However, this method includes several washing steps. In this context, we have developed a rapid, sensitive, and accurate fluorimetric method adapted to 96-well microplates for the convenient assessment of protein carbonyl level in biological samples. The method reported here is based on the reaction of carbonyl content in proteins with 7-hydrazino-4-nitrobenzo-2,1,3-oxadiazole (NBDH) to form highly fluorescent derivatives via hydrazone formation. PCs were determined using the DNPH and NBDH assays in fully reduced bovine serum albumin (BSA) and plasma and liver homogenates obtained from healthy control rats up the addition of various amounts of HOCl-oxidized BSA (OxBSA). Using the NBDH assay, PC concentrations as low as 0.2 nmol/mg were detected with precision as low as 5%. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectroscopy was used to successfully identify the formation of the NBDH adducts after derivatization with standard oxidized peptides. Finally, the two methods were further used for PC determination in plasma and liver samples from diabetic and normal rats, showing that the NBDH assay can be reliably used in biological experiments. PMID:25933703

  19. Protein Carbonylation and Adipocyte Mitochondrial Function*

    PubMed Central

    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

  20. Palladium-catalyzed oxidative carbonylation reactions.

    PubMed

    Wu, Xiao-Feng; Neumann, Helfried; Beller, Matthias

    2013-02-01

    Palladium-catalyzed coupling reactions have become a powerful tool for advanced organic synthesis. This type of reaction is of significant value for the preparation of pharmaceuticals, agrochemicals, as well as advanced materials. Both, academic as well as industrial laboratories continuously investigate new applications of the different methodologies. Clearly, this area constitutes one of the major topics in homogeneous catalysis and organic synthesis. Among the different palladium-catalyzed coupling reactions, several carbonylations have been developed and widely used in organic syntheses and are even applied in the pharmaceutical industry on ton-scale. Furthermore, methodologies such as the carbonylative Suzuki and Sonogashira reactions allow for the preparation of interesting building blocks, which can be easily refined further on. Although carbonylative coupling reactions of aryl halides have been well established, palladium-catalyzed oxidative carbonylation reactions are also interesting. Compared with the reactions of aryl halides, oxidative carbonylation reactions offer an interesting pathway. The oxidative addition step could be potentially avoided in oxidative reactions, but only few reviews exist in this area. In this Minireview, we summarize the recent development in the oxidative carbonylation reactions. PMID:23307763

  1. The influence of the new enkephalin derivative, cyclo[N(ε),N(β)-carbonyl-d-Lys(2),Dap(5)] enkephalinamide (cUENK6), on reinstatement of ethanol-induced conditioned place preference in rats.

    PubMed

    Gibula-Bruzda, Ewa; Marszalek-Grabska, Marta; Gawel, Kinga; Witkowska, Ewa; Izdebski, Jan; Kotlinska, Jolanta H

    2015-06-01

    The aim of the present study was to determine whether a new cyclic analog of enkephalin, cyclo[N(ε),N(β)-carbonyl-d-Lys(2),Dap(5)] enkephalinamide (cUENK6), a preferential μ-(MORs), and, to a lower extent, a δ-opioid receptor (DORs) agonist in vitro, could reinstate ethanol-induced conditioned place preference (CPP). In our work, male Wistar rats were first conditioned either with ethanol (10% w/v, 0.5g/kg, intraperitoneally (i.p.)) or 0.9% NaCl in a biased CPP procedure. The intracerebroventricular (i.c.v.) administration of DORs antagonist (naltrindole, 2.5 and 5nmol) or MORs antagonist (β-funaltrexamine, 5 and 10nmol), but not the κ opioid receptor (KORs) antagonist (norbinaltorphimine, 5 and 10nmol) was then administered and inhibited the expression of ethanol-induced CPP. After the extinction session, i.c.v. administration of cUENK6 at the dose of 0.125, 0.25 and 0.5nmol occurred, and was found to reinstate the ethanol-induced CPP similar to that of the priming injection of ethanol. However, the reinstated effect of cUENK6 (0.25nmol) was strongly abolished by administration of naltrindole and, to lesser extent, by β-funaltrexamine. Furthermore, the preferential MORs agonist-morphine (13nmol, i.c.v.) and the DORs agonist-[Leu(5)]-enkephalin (2.7 and 5.4nmol, i.c.v.) also reinstated the ethanol-induced CPP. cUENK6 given alone at the dose of 0.25nmol before the testing phase had no effect in animals that received 0.9% NaCl during the conditioning phase and also did not influence their locomotor activity. These data suggest that the effects of cUENK6 did not have an impact on the results obtained in the reinstatement procedure of CPP. Overall, the data support the idea that both MORs and DORs are normally involved in the expression and reinstatement of ethanol conditioned seeking behavior - as indexed by CPP in rats. PMID:25817357

  2. Comparison of Two Old Phytochemicals versus Two Newly Researched Plant-Derived Compounds: Potential for Brain and Other Relevant Ailments.

    PubMed

    Wang, Chun-Mei; Liang, Willmann; Yew, D T

    2014-01-01

    Among hundreds of formulae of Chinese herbal prescriptions and recently extracted active components from the herbs, some of which had demonstrated their functions on nervous system. For the last decade or more, Gingko biloba and Polygala tenuifolia were widely studied for their beneficial effects against damage to the brain. Two compounds extracted from Apium graveolens and Rhizoma coptidis, butylphthalide and berberine, respectively, received much attention recently as potential neuroprotective agents. In this review, the two traditionally used herbs and the two relatively new compounds will be discussed with regard to their potential advantages in alleviating brain and other relevant ailments. PMID:24949079

  3. Comparison of Two Old Phytochemicals versus Two Newly Researched Plant-Derived Compounds: Potential for Brain and Other Relevant Ailments

    PubMed Central

    Wang, Chun-Mei; Yew, D. T.

    2014-01-01

    Among hundreds of formulae of Chinese herbal prescriptions and recently extracted active components from the herbs, some of which had demonstrated their functions on nervous system. For the last decade or more, Gingko biloba and Polygala tenuifolia were widely studied for their beneficial effects against damage to the brain. Two compounds extracted from Apium graveolens and Rhizoma coptidis, butylphthalide and berberine, respectively, received much attention recently as potential neuroprotective agents. In this review, the two traditionally used herbs and the two relatively new compounds will be discussed with regard to their potential advantages in alleviating brain and other relevant ailments. PMID:24949079

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

    PubMed

    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. PMID:25282656

  5. Stratospheric carbonyl sulfide (OCS) burden

    NASA Astrophysics Data System (ADS)

    Kloss, Corinna; Walker, Kaley A.; Deshler, Terry; von Hobe, Marc

    2015-04-01

    An estimation of the global stratospheric burden of carbonyl sulfide (OCS) calculated using satellite based measurements from the Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS) will be presented. OCS is the most abundant sulfur containing gas in the atmosphere in the absence of volcanic eruptions. With a long lifetime of 2-6 years it reaches the stratosphere where it is photolyzed and the sulfur oxidized and condensed to aerosols, contributing to the stratospheric aerosol layer. The aerosol layer is the one factor of the middle-atmosphere with a direct impact on the Earth's climate by scattering incoming solar radiation back to space. Therefore it is crucial to understand and estimate the different processes and abundances of the species contributing to the aerosol layer. However, the exact amount of OCS in the stratosphere has not been quantified yet. A study on the OCS mixing ratio distribution based on ACE-FTS data has already been made by Barkley et al. (2008), also giving an estimation for the total atmospheric OCS mass. ACE-FTS is an infrared solar occultation spectrometer providing high- resolution profile observations since 2004. In the scope of this work the focus lies on the stratospheric OCS burden, calculated by integrating the ACE profiles. A global overview on the stratospheric OCS amount in the past and present based on the ACE data as well as a look at regional and seasonal variability will be given. Furthermore, the results of this work will be useful for further studies on OCS fluxes and lifetimes, and in quantifying the contribution of OCS to the global stratospheric sulfur burden. Barkley et al., 2008, Geophys. Res. Lett., 35, L14810.

  6. Relevance of near-Earth magnetic field modeling in deriving SEP properties using ground-based data

    NASA Astrophysics Data System (ADS)

    Kanellakopoulos, Anastasios; Plainaki, Christina; Mavromichalaki, Helen; Laurenza, Monica; Gerontidou, Maria; Storini, Marisa; Andriopoulou, Maria

    2014-05-01

    Ground Level Enhancements (GLEs) are short-term increases observed in cosmic ray intensity records of ground-based particle detectors such as neutron monitors (NMs) or muon detectors; they are related to the arrival of solar relativistic particles in the terrestrial environment. Hence, GLE events are related to the most energetic class of solar energetic particle (SEP) events. In this work we investigate how the use of different magnetospheric field models can influence the derivation of the relativistic SEP properties when modeling GLE events. As a case study, we examine the event of 2012 May 17 (also known as GLE71), registered by ground-based NMs. We apply the Tsyganenko 89 and the Tsyganenko 96 models in order to calculate the trajectories of the arriving SEPs in the near-Earth environment. We show that the intersection of the SEP trajectories with the atmospheric layer at ~20 km from the Earth's surface (i.e., where the flux of the generated secondary particles is maximum), forms for each ground-based neutron monitor a specified viewing region that is dependent on the magnetospheric field configuration. Then, we apply the Neutron Monitor Based Anisotropic GLE Pure Power Law (NMBANGLE PPOLA) model (Plainaki et al. 2010, Solar Phys, 264, 239), in order to derive the spectral properties of the related SEP event and the spatial distributions of the SEP fluxes impacting the Earth's atmosphere. We examine the dependence of the results on the used magnetic field models and evaluate their range of validity. Finally we discuss information derived by modeling the SEP spectrum in the frame of particle acceleration scenarios.

  7. Alterations in the Secretome of Clinically Relevant Preparations of Adipose-Derived Mesenchymal Stem Cells Cocultured with Hyaluronan

    PubMed Central

    Succar, Peter; Breen, Edmond J.; Kuah, Donald; Herbert, Benjamin R.

    2015-01-01

    Osteoarthritis (OA) can be a debilitating degenerative disease and is the most common form of arthritic disease. There is a general consensus that current nonsurgical therapies are insufficient for younger OA sufferers who are not candidates for knee arthroplasties. Adipose-derived mesenchymal stem cells (MSCs) therapy for the treatment of OA can slow disease progression and lead to neocartilage formation. The mechanism of action is secretion driven. Current clinical preparations from adipose tissue for the treatment of OA include autologous stromal vascular fraction (SVF), SVF plus mature adipocytes, and culture-purified MSCs. Herein we have combined these human adipose-derived preparations with Hyaluronan (Hylan G-F 20: Synvisc) in vitro and measured alterations in cytokine profile. SVF plus mature adipocytes showed the greatest decreased in the proinflammatory cytokines IL-1β, IFN-γ, and VEGF. MCP-1 and MIP-1α decreased substantially in the SVF preparations but not the purified MSCs. The purified MSC preparation was the only one to show increase in MIF. Overall the SVF plus mature adipocytes preparation may be most suited of all the preparations for combination with HA for the treatment of OA, based on the alterations of heavily implicated cytokines in OA disease progression. This will require further validation using in vivo models. PMID:26257790

  8. Paracrine effects and heterogeneity of marrow-derived stem/progenitor cells: relevance for the treatment of respiratory diseases.

    PubMed

    Conese, Massimo; Carbone, Annalucia; Castellani, Stefano; Di Gioia, Sante

    2013-01-01

    Stem cell-based treatment may represent a hope for the treatment of acute lung injury and pulmonary fibrosis, and other chronic lung diseases, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease (COPD). It is well established in preclinical models that bone marrow-derived stem and progenitor cells exert beneficial effects on inflammation, immune responses and repairing of damage in virtually all lung-borne diseases. While it was initially thought that the positive outcome was due to a direct engraftment of these cells into the lung as endothelial and epithelial cells, paracrine factors are now considered the main mechanism through which stem and progenitor cells exert their therapeutic effect. This knowledge has led to the clinical use of marrow cells in pulmonary hypertension with endothelial progenitor cells (EPCs) and in COPD with mesenchymal stromal (stem) cells (MSCs). Bone marrow-derived stem cells, including hematopoietic stem/progenitor cells, MSCs, EPCs and fibrocytes, encompass a wide array of cell subsets with different capacities of engraftment and injured tissue-regenerating potential. The characterization/isolation of the stem cell subpopulations represents a major challenge to improve the efficacy of transplantation protocols used in regenerative medicine and applied to lung disorders. PMID:23652321

  9. Combined effect of clinically relevant doses of emitefur, a new 5-fluorouracil derivative, and radiation in murine tumours.

    PubMed Central

    Shibamoto, Y.; Murata, R.; Miyauchi, S.; Hirohashi, M.; Takagi, T.; Sasai, K.; Shibata, T.; Oya, N.; Takahashi, M.

    1996-01-01

    We investigated the combined effect of radiation and clinically relevant doses of emitefur (BOF-A2), a newly developed anti-cancer agent consisting of a masked form of 5-fluorouracil (5-FU) and a potent inhibitor of 5-FU degradation, in two types of murine tumours. In preliminary pharmacokinetic studies, the area under the curve for 5-FU in plasma, after administration of 12.5 mg kg-1 and 25 mg kg-1 emitefur in mice, appeared to be similar to that obtained on the first day and that on the seventh day, respectively, after starting administration of 400-600 mg day-1 in humans. These doses (12.5 and 25 mg kg-1) of emitefur were evaluated either alone or in combination with single (15 Gy), five-fraction (4 Gy each) or ten-fraction (2.8 Gy each) irradiation using a tumour growth delay assay for SCCVII tumours and in combination with four-fraction (5 Gy each) irradiation using an in vivo-in vitro assay for EMT6 tumours. The anti-tumour and radiation-enhancing effects of 12.5 mg kg-1 emitefur were not significant in any except the ten-fraction experiment. On the other hand, multiple doses of 25 mg kg-1 emitefur given either alone or in combination with radiation produced marked effects. The mean tumour growth delay time (the time to double in volume for treated tumours minus that for untreated tumours) was 8.1 days for five administrations of 25 mg kg-1 emitefur. 10.4 days for five fractions of 4 Gy and 22.1 days for five treatments with the combination of the two. Thus, the increase in growth delay afforded by this combination was at least additive. The effect of four fractions of 5 Gy with 25 mg kg-1 emitefur in EMT6 tumours was lower than that of four fractions of 7.5 Gy, but the effect of five fractions of 4 Gy with this dose of emitefur in SCCVII tumours was similar to the effect of five fractions of 6 Gy, and the effect of ten fractions of 2.8 Gy with 25 mg kg-1 emitefur was much higher than that of ten fractions of 4.2 Gy. In conclusion, emitefur given either alone

  10. Characteristic infrared intensities of carbonyl stretching vibrations.

    PubMed

    Richter, Wagner E; Silva, Arnaldo F; Vidal, Luciano N; Bruns, Roy E

    2016-07-14

    The experimental infrared fundamental intensities of gas phase carbonyl compounds obtained by the integration of spectral bands in the Pacific Northwest National Laboratory (PNNL) spectral database are in good agreement with the intensities reported by other laboratories having a root mean square error of 27 km mol(-1) or about 13% of the average intensity value. The Quantum Theory of Atoms in Molecules/Charge-Charge Transfer-Counterpolarization (QTAIM/CCTCP) model indicates that the large intensity variation from 61.7 to 415.4 km mol(-1) is largely due to static atomic charge contributions, whereas charge transfer and counterpolarization effects essentially cancel one another leaving only a small net effect. The Characteristic Substituent Shift Model estimates the atomic charge contributions to the carbonyl stretching intensities within 30 km mol(-1) or 10% of the average contribution. However, owing to the size of the 2 × C × CTCP interaction contribution, the total intensities cannot be estimated with this degree of accuracy. The dynamic intensity contributions of the carbon and oxygen atoms account for almost all of the total stretching intensities. These contributions vary over large ranges with the dynamic contributions of carbon being about twice the size of the oxygen ones for a large majority of carbonyls. Although the carbon monoxide molecule has an almost null dipole moment contrary to the very polar bond of the characteristic carbonyl group, its QTAIM/CCTCP model is very similar to those found for the carbonyl compounds. PMID:27306140

  11. Oxidative stress induced carbonylation in human plasma.

    PubMed

    Madian, Ashraf G; Diaz-Maldonado, Naomi; Gao, Qiang; Regnier, Fred E

    2011-10-19

    The focus of this study was on the assessment of technology that might be of clinical utility in identification, quantification, characterization of carbonylation in human plasma proteins. Carbonylation is widely associated with oxidative stress diseases. Breast cancer patient samples were chosen as a stress positive case based on the fact that oxidative stress has been reported to be elevated in this disease. Measurements of 8-isoprostane in plasma confirmed that breast cancer patients in this study were indeed experiencing significant oxidative stress. Carbonyl groups in proteins from freshly drawn blood were derivatized with biotin hydrazide after which the samples were dialyzed and the biotinylated proteins subsequently selected, digested and labeled with iTRAQ™ heavy isotope coding reagent(s). Four hundred sixty proteins were identified and quantified, 95 of which changed 1.5 fold or more in concentration. Beyond confirming the utility of the analytical method, association of protein carbonylation was examined as well. Nearly one fourth of the selected proteins were of cytoplasmic, nuclear, or membrane origin. Analysis of the data by unbiased knowledge assembly methods indicated the most likely disease associated with the proteins was breast neoplasm. Pathway analysis showed the proteins which changed in carbonylation were strongly associated with Brca1, the breast cancer type-1 susceptibility protein. Pathway analysis indicated the major molecular functions of these proteins are defense, immunity and nucleic acid binding. PMID:21856457

  12. Oxidative stress induced carbonylation in human plasma

    PubMed Central

    Madian, Ashraf G.; Diaz-Maldonado, Naomi; Gao, Qiang; Regnier, Fred E.

    2011-01-01

    The focus of this study was on the assessment of technology that might be of clinical utility in identification, quantification, characterization of carbonylation in human plasma proteins. Carbonylation is widely associated with oxidative stress diseases. Breast cancer patient samples were chosen as a stress positive case based on the fact that oxidative stress has been reported to be elevated in this disease. Measurements of 8-isoprostane in plasma confirmed that breast cancer patients in this study were indeed experiencing significant oxidative stress. Carbonyl groups in proteins from freshly drawn blood were derivatized with biotin hydrazide after which the samples were dialyzed and the biotinylated proteins subsequently selected, digested and labeled with iTRAQ™ heavy isotope coding reagent(s). Four hundred sixty proteins were identified and quantified, 95 of which changed 1.5 fold or more in concentration. Beyond confirming the utility of the analytical method, association of protein carbonylation was examined as well. Nearly one fourth of the selected proteins were of cytoplasmic, nuclear, or membrane origin. Analysis of the data by unbiased knowledge assembly methods indicated the most likely disease associated with the proteins was breast neoplasm. Pathway analysis showed the proteins which changed in carbonylation were strongly associated with Brca1, the breast cancer type-1 susceptibility protein. Pathway analysis indicated the major molecular functions of these proteins are defense, immunity and nucleic acid binding. PMID:21856457

  13. Process and catalyst for carbonylating olefins

    DOEpatents

    Zoeller, Joseph Robert

    1998-06-02

    Disclosed is an improved catalyst system and process for preparing aliphatic carbonyl compounds such as aliphatic carboxylic acids, alkyl esters of aliphatic carboxylic acids and anhydrides of aliphatic carboxylic acids by carbonylating olefins in the presence of a catalyst system comprising (1) a first component selected from at least one Group 6 metal, i.e., chromium, molybdenum, and/or tungsten and (2) a second component selected from at least one of certain halides and tertiary and quaternary compounds of a Group 15 element, i.e., nitrogen, phosphorus and/or arsenic, and (3) as a third component, a polar, aprotic solvent. The process employing the improved catalyst system is carried out under carbonylating conditions of pressure and temperature discussed herein. The process constitutes and improvement over known processes since it can be carried out at moderate carbonylation conditions without the necessity of using an expensive noble metal catalyst, volatile, toxic materials such as nickel tetracarbonyl, formic acid or a formate ester. Further, the addition of a polar, aprotic solvent to the catalyst system significantly increases, or accelerates, the rate at which the carbonylation takes place.

  14. Relevance of risk predictions derived from a chronic species sensitivity distribution with cadmium to aquatic populations and ecosystems

    USGS Publications Warehouse

    Mebane, C.A.

    2010-01-01

    Criteria to protect aquatic life are intended to protect diverse ecosystems, but in practice are usually developed from compilations of single-species toxicity tests using standard test organisms that were tested in laboratory environments. Species sensitivity distributions (SSDs) developed from these compilations are extrapolated to set aquatic ecosystem criteria. The protectiveness of the approach was critically reviewed with a chronic SSD for cadmium comprising 27 species within 21 genera. Within the data set, one genus had lower cadmium effects concentrations than the SSD fifth percentile-based criterion, so in theory this genus, the amphipod Hyalella, could be lost or at least allowed some level of harm by this criteria approach. However, population matrix modeling projected only slightly increased extinction risks for a temperate Hyalella population under scenarios similar to the SSD fifth percentile criterion. The criterion value was further compared to cadmium effects concentrations in ecosystem experiments and field studies. Generally, few adverse effects were inferred from ecosystem experiments at concentrations less than the SSD fifth percentile criterion. Exceptions were behavioral impairments in simplified food web studies. No adverse effects were apparent in field studies under conditions that seldom exceeded the criterion. At concentrations greater than the SSD fifth percentile, the magnitudes of adverse effects in the field studies were roughly proportional to the laboratory-based fraction of species with adverse effects in the SSD. Overall, the modeling and field validation comparisons of the chronic criterion values generally supported the relevance and protectiveness of the SSD fifth percentile approach with cadmium. ?? 2009 Society for Risk Analysis.

  15. Synthesis of Diiron(I) Dithiolato Carbonyl Complexes.

    PubMed

    Li, Yulong; Rauchfuss, Thomas B

    2016-06-22

    Virtually all organosulfur compounds react with Fe(0) carbonyls to give the title complexes. These reactions are reviewed in light of major advances over the past few decades, spurred by interest in Fe2(μ-SR)2(CO)x centers at the active sites of the [FeFe]-hydrogenase enzymes. The most useful synthetic route to Fe2(μ-SR)2(CO)6 involves the reaction of thiols with Fe2(CO)9 and Fe3(CO)12. Such reactions can proceed via mono-, di-, and triiron intermediates. The reactivity of Fe(0) carbonyls toward thiols is highly chemoselective, and the resulting dithiolato complexes are fairly rugged. Thus, many complexes tolerate further synthetic elaboration directed at the organic substituents. A second major route involves alkylation of Fe2(μ-S2)(CO)6, Fe2(μ-SH)2(CO)6, and Li2Fe2(μ-S)2(CO)6. This approach is especially useful for azadithiolates Fe2[(μ-SCH2)2NR](CO)6. Elaborate complexes arise via addition of the FeSH group to electrophilic alkenes, alkynes, and carbonyls. Although the first example of Fe2(μ-SR)2(CO)6 was prepared from ferrous reagents, ferrous compounds are infrequently used, although the Fe(II)(SR)2 + Fe(0) condensation reaction is promising. Almost invariably low-yielding, the reaction of Fe3(CO)12, S8, and a variety of unsaturated substrates results in C-H activation, affording otherwise inaccessible derivatives. Thiones and related C═S-containing reagents are highly reactive toward Fe(0), often giving complexes derived from substituted methanedithiolates and C-H activation. PMID:27258046

  16. Calibration of commercial microwave link derived- rainfall and its relevance to flash flood occurrence in the Dead Sea area

    NASA Astrophysics Data System (ADS)

    Eshel, Adam; Alpert, Pinhas; Raich, Roi; Laronne, Jonathan; Merz, Ralf; Geyer, Stefan; Corsmeier, Ulrich

    2016-04-01

    Flash floods are a common phenomenon in arid and semi-arid areas such as the Dead Sea. These floods are generated due to a combination of short lasting, yet intense rainfall and typical low infiltration rates. The rare flow events in ephemeral rivers have significant importance in the replenishment of groundwater via transmission losses and in sustaining the vivid ecology of drylands. In some cases, flash floods cause severe damage to infrastructure as well as to private property, constituting a threat to human life. The temporal variation of rainfall intensity is the main driver generating the majority of flash floods in the Judean Desert, hence its monitoring is crucial in this area as in other remote arid areas worldwide. Cellular communication towers are profusely located. Commercial Microwave Links (CML) attenuation data obtained by cellular companies can be used for environmental monitoring. Rain is one of the most effective meteorological phenomena to attenuate a CML signal which, unlike radar backscatter, relates to near-surface conditions and is, therefore, suitable for surface hydrology. A 16 km CML crosses the Wadi Ze'elim drainage basin (~250 square kilometers), at the outlet of which the discharge is calculated using the Manning formula. The hydrometric data include accurate longitudinal and cross sectional measurements, water level and importantly mean water surface velocity when present during a flash flood. The latter is first-ever obtained in desert flash floods by portable, radar-based surface velocimetry. Acquisition of water velocity data is essential to avoid assuming a constant roughness coefficient, thereby more accurately calculating water discharge. Calibrating the CML-rain intensity, derived from the International Telecommunication Union (ITU)'s power law, is necessary to correlate the surface hydrologic response to the link. Our calibration approach is as follows: all the Israel Meteorological Service C-band radar cells over the CML

  17. A theobromine derived silver N-heterocyclic carbene: synthesis, characterization, and antimicrobial efficacy studies on cystic fibrosis relevant pathogens†

    PubMed Central

    Panzner, Matthew J.; Hindi, Khadijah M.; Wright, Brian D.; Taylor, Jane B.; Han, Daniel S.

    2009-01-01

    The increasing incidence of multidrug-resistant (MDR) pulmonary infections in the cystic fibrosis (CF) population has prompted the investigation of innovative silver based therapeutics. The functionalization of the naturally occurring xanthine theobromine at the N1 nitrogen atom with an ethanol substituent followed by the methylation of the N9 nitrogen atom gives the N-heterocyclic carbene precursor 1-(2-hydroxyethyl)-3,7,9-trimethylxanthinium iodide. The reaction of this xanthinium salt with silver acetate produces the highly hydrophilic silver carbene complex SCC8. The in vitro antimicrobial efficacy of this newly synthesized complex was evaluated with excellent results on a variety of virulent and MDR pathogens isolated from CF patients. A comparative in vivo study between the known caffeine derived silver carbene SCC1 and SCC8 demonstrated the ability of both complexes to improve the survival rates of mice in a pneumonia model utilizing the clinically isolated infectious strain of Pseudomonas aeruginosa PA M57-15. PMID:20449175

  18. Intrapericardial Delivery of Cardiosphere-Derived Cells: An Immunological Study in a Clinically Relevant Large Animal Model

    PubMed Central

    Crisóstomo, Verónica; Báez, Claudia; Maestre, Juan; Álvarez, Verónica

    2016-01-01

    Introduction The intrapericardial delivery has been defined as an efficient method for pharmacological agent delivery. Here we hypothesize that intrapericardial administration of cardiosphere-derived cells (CDCs) may have an immunomodulatory effect providing an optimal microenvironment for promoting cardiac repair. To our knowledge, this is the first report studying the effects of CDCs for myocardial repair using the intrapericardial delivery route. Material and Methods CDCs lines were isolated, expanded and characterized by flow cytometry and PCR. Their differentiation ability was determined using specific culture media and differential staining. 300,000 CDCs/kg were injected into the pericardial space of a swine myocardial infarcted model. Magnetic resonance imaging, biochemical analysis of pericardial fluid and plasma, cytokine measurements and flow cytometry analysis were performed. Results Our results showed that, phenotype and differentiation behavior of porcine CDCs were equivalent to previously described CDCs. Moreover, the intrapericardial administration of CDCs fulfilled the safety aspects as non-adverse effects were reported. Finally, the phenotypes of resident lymphocytes and TH1 cytokines in the pericardial fluid were significantly altered after CDCs administration. Conclusions The pericardial fluid could be considered as a safe and optimal vehicle for CDCs administration. The observed changes in the studied immunological parameters could exert a modulation in the inflammatory environment of infarcted hearts, indirectly benefiting the endogenous cardiac repair. PMID:26866919

  19. Pigment-epithelium-derived factor (PEDF) occurs at a physiologically relevant concentration in human blood: purification and characterization.

    PubMed Central

    Petersen, Steen V; Valnickova, Zuzana; Enghild, Jan J

    2003-01-01

    Pigment epithelium-derived factor (PEDF) inhibits the formation of blood vessels in the eye by inducing apotosis in actively dividing endothelial cells. The activity of PEDF equals or supersedes that of other anti-angiogenic factors, including angiostatin, endostatin and thrombospondin-1. In addition, PEDF has the potential to promote the survival of neurons and affect their differentiation. Here we show that PEDF is present in plasma at a concentration of approx. 100 nM (5 microg/ml) or twice the level required to inhibit aberrant blood-vessel growth in the eye. Thus the systemic delivery of PEDF has the potential to affect angiogenesis or neurotrophic processes throughout the body, significantly expanding the putative physiological role of the protein. A complete map of all post-translational modifications revealed that authentic plasma PEDF carries an N-terminal pyroglutamate blocking group and an N-linked glycan at position Asn266. The pyroglutamate residue may regulate the activity of PEDF analogously to the manner in which it regulates thyrotropin-releasing hormone. PMID:12737624

  20. The relevance of gene transfer to the safety of food and feed derived from genetically modified (GM) plants.

    PubMed

    van den Eede, G; Aarts, H; Buhk, H-J; Corthier, G; Flint, H J; Hammes, W; Jacobsen, B; Midtvedt, T; van der Vossen, J; von Wright, A; Wackernagel, W; Wilcks, A

    2004-07-01

    In 2000, the thematic network ENTRANSFOOD was launched to assess four different topics that are all related to the testing or assessment of food containing or produced from genetically modified organisms (GMOs). Each of the topics was linked to a European Commission (EC)-funded large shared cost action (see http://www.entransfood.com). Since the exchange of genetic information through horizontal (lateral) gene transfer (HGT) might play a more important role, in quantity and quality, than hitherto imagined, a working group dealing with HGT in the context of food and feed safety was established. This working group was linked to the GMOBILITY project (GMOBILITY, 2003) and the results of the deliberations are laid down in this review paper. HGT is reviewed in relation to the potential risks of consuming food or feed derived from transgenic crops. First, the mechanisms for obtaining transgenic crops are described. Next, HGT mechanisms and its possible evolutionary role are described. The use of marker genes is presented in detail as a special case for genes that may pose a risk. Furthermore, the exposure to GMOs and in particular to genetically modified (GM) deoxyribonucleic acid (DNA) is discussed as part of the total risk assessment. The review finishes off with a number of conclusions related to GM food and feed safety. The aim of this paper is to provide a comprehensive overview to assist risk assessors as well as regulators and the general public in understanding the safety issues related to these mechanisms. PMID:15123384

  1. Correlation between structure, retention, property, and activity of biologically relevant 1,7-bis(aminoalkyl)diazachrysene derivatives.

    PubMed

    Šegan, Sandra; Trifković, Jelena; Verbić, Tatjana; Opsenica, Dejan; Zlatović, Mario; Burnett, James; Šolaja, Bogdan; Milojković-Opsenica, Dušanka

    2013-01-01

    The physicochemical properties, retention parameters (R(M)(0)), partition coefficients (logP(OW)), and pK(a) values for a series of thirteen 1,7-bis(aminoalkyl) diazachrysene (1,7-DAAC) derivatives were determined in order to reveal the characteristics responsible for their biological behavior. The investigated compounds inhibit three unrelated pathogens (the Botulinum neurotoxin serotype A light chain (BoNT/A LC), Plasmodium falciparum malaria, and Ebola filovirus) via three different mechanisms of action. To determine the most influential factors governing the retention and activities of the investigated diazachrysenes, R(M)(0), logP(OW), and biological activity values were correlated with 2D and 3D molecular descriptors, using a partial least squares regression. The resulting quantitative structure-retention (property) relationships indicate the importance of descriptors related to the hydrophobicity of the molecules (e.g., predicted partition coefficients and hydrophobic surface area). Quantitative structure-activity relationship models for describing biological activity against the BoNT/A LC and malarial strains also include overall compound polarity, electron density distribution, and proton donor/acceptor potential. Furthermore, models for Ebola filovirus inhibition are presented qualitatively to provide insights into parameters that may contribute to the compounds' antiviral activities. Overall, the models form the basis for selecting structural features that significantly affect the compound's absorption, distribution, metabolism, excretion, and toxicity profiles. PMID:22985530

  2. Carbonyl compounds indoors in a changing climate

    PubMed Central

    2012-01-01

    Background Formic acid, acetic acid and formaldehyde are important compounds in the indoor environment because of the potential for these acids to degrade calcareous materials (shells, eggs, tiles and geological specimens), paper and corrode or tarnish metals, especially copper and lead. Carbonyl sulfide tarnishes both silver and copper encouraging the formation of surface sulfides. Results Carbonyls are evolved more quickly at higher temperatures likely in the Cartoon Gallery at Knole, an important historic house near Sevenoaks in Kent, England where the study is focused. There is a potential for higher concentrations to accumulate. However, it may well be that in warmer climates they will be depleted more rapidly if ventilation increases. Conclusions Carbonyls are likely to have a greater impact in the future. PMID:22439648

  3. Carbonyl extraction of lunar and asteroidal metals

    NASA Astrophysics Data System (ADS)

    Lewis, John S.; Jones, Thomas D.; Farrand, William H.

    It is suggested that the Mond process for carbonyl extraction of metals from ore may be used as an efficient, low-energy scheme for producing high-purity Fe, Ni, Cr, Mn, and Co from lunar or asteroidal feedstocks. It is proposed that scenarios for obtaining oxygen from the lunar relogith can be enhanced by carbonyl processing of the metallic alloy byproducts of such operations. It is further suggested that the native metal content of asteroidal regoliths is even more suitable to carbonyl processing. High-purity, corrosion-resistant Fe and Ni can be extracted from asteroidal feedstocks along with a Co-rich residue containing 0.5 percent platinum-group metals. Recommendations for bringing the method to a practical level of development for space applications are presented.

  4. Copper-Catalyzed Carbonylative Coupling of Cycloalkanes and Amides.

    PubMed

    Li, Yahui; Dong, Kaiwu; Zhu, Fengxiang; Wang, Zechao; Wu, Xiao-Feng

    2016-06-13

    Carbonylation reactions are a most powerful method for the synthesis of carbonyl-containing compounds. However, most known carbonylation procedures still require noble-metal catalysts and the use of activated compounds and good nucleophiles as substrates. Herein, we developed a copper-catalyzed carbonylative transformation of cycloalkanes and amides. Imides were prepared in good yields by carbonylation of a C(sp(3) )-H bond of the cycloalkane with the amides acting as weak nucleophiles. Notably, this is the first report of copper-catalyzed carbonylative C-H activation. PMID:27167881

  5. Retina-derived POU domain factor 1 coordinates expression of genes relevant to renal and neuronal development.

    PubMed

    Fiorino, Antonio; Manenti, Giacomo; Gamba, Beatrice; Bucci, Gabriele; De Cecco, Loris; Sardella, Michele; Buscemi, Giacomo; Ciceri, Sara; Radice, Maria T; Radice, Paolo; Perotti, Daniela

    2016-09-01

    Retina-derived POU domain Factor 1 (RPF-1), a member of POU transcription factor family, is encoded by POU6F2 gene, addressed by interstitial deletions at chromosome 7p14 in Wilms tumor (WT). Its expression has been detected in developing kidney and nervous system, suggesting an early role for this gene in regulating development of these organs. To investigate into its functions and determine its role in transcriptional regulation, we generated an inducible stable transfectant from HEK293 cells. RPF-1 showed nuclear localization, elevated stability, and transactivation of promoters featuring POU consensus sites, and led to reduced cell proliferation and in vivo tumor growth. By addressing the whole transcriptome regulated by its induction, we could detect a gross alteration of gene expression that is consistent with promoter occupancy predicted by genome-wide Chip-chip analysis. Comparison of bound regulatory regions with differentially expressed genes allowed identification of 217 candidate targets. Enrichment of divergent octamers in predicted regulatory regions revealed promiscuous binding to bipartite POUS and POUH consensus half-sites with intervening spacers. Gel-shift competition assay confirmed the specificity of RPF-1 binding to consensus motifs, and demonstrated that the Ser-rich region upstream of the POU domain is indispensable to achieve DNA-binding. Promoter-reporter activity addressing a few target genes indicated a dependence by RPF-1 on transcriptional response. In agreement with its expression in developing kidney and nervous system, the induced transcriptome appears to indicate a function for this protein in early renal differentiation and neuronal cell fate, providing a resource for understanding its role in the processes thereby regulated. PMID:27425396

  6. Advances in Measurement of Carbonyls in Aerosols.

    NASA Astrophysics Data System (ADS)

    Charles, M.; Jakober, C.; Spaulding, R.; Green, P.; Destaillats, H.; Hughes, J. M.

    2002-12-01

    Chamber studies establish the formation of highly polar oxygenated species from the reaction of anthropogenic and biogenic hydrocarbons with hydroxyl radicals or ozone. A paucity of data exists however on the generation and fate of these organics in the ambient atmospheric environment. This is primarily due to the absence of suitable analytical methods. To address limitations of existing methods, we developed methods that rely on O-(2,3,4,5,6)-pentafluorobenzylhydroxylamine (PFBHA), and bis-(trimethylsilyl) trifluoroacetamide (BSTFA) in concert with GC/ion trap mass spectrometry (GC/ITMS) to identify and quantify carbonyl, dicarbonyl and hydroxy carbonyl photooxidation products in aerosols at part-per-trillion (pptv) levels. We also optimized and evaluated a mist chamber to sample carbonyls and multi-functional carbonyls with 10 minute sampling times. We applied the method to identify and quantify 2-hydroxy-2-methyl propanal (2-HMPR), a proposed photooxidation product of 2-methyl-3-buten-2-ol (MBO) in the Blodgett Forest, CA. The average 2-HMPR/MBO mixing ratio was 0.33ñ 0.25, which is reasonable since the expected yield of 2-HMPR from the hydroxyl radical oxidation of MBO is 0.19-0.35. Further method development in our laboratory is exploring the employment of HPLC/atmospheric pressure chemical ionization (APCI) mass spectra to identify model aliphatic and aromatic carbonyls (the major classes were aldehydes, ketones, dicarbonyls, and quinones) in aerosols. The data indicate the potential for pentafluorobenzyl derivatization in concert with GC/ITMS and HPLC/ITMS to measure a broad range of carbonyls.

  7. Reaction of (chloro carbonyl) phenyl ketene with 5-amino pyrazolones: Synthesis, characterization and theoretical studies of 7-hydroxy-6-phenyl-3-(phenyldiazenyl)pyrazolo[1,5-a]pyrimidine-2,5(1H,4H)-dione derivatives

    NASA Astrophysics Data System (ADS)

    Zahedifar, Mahboobeh; Razavi, Razieh; Sheibani, Hassan

    2016-12-01

    New 7-hydroxy-6-phenyl-3-(phenyldiazenyl)pyrazolo[1,5-a]pyrimidine-2,5(1H,4H)-dione derivatives were synthesized from the reaction of (chlorocarbonyl)phenyl ketene and 5-amino pyrazolones in high to excellent yields and short reaction times. Structures of the new compounds were fully characterized by their spectral data IR, 1H NMR, and 13C NMR and by the theoretical results. Density Functional Theory (DFT) was used to optimize the structures, compute the energies and vibrational frequencies IR and 1H NMR shielding tensors of the desired products. The theoretical results excellent are compared with the experimental data.

  8. Palladium/copper-catalyzed oxidative C-H alkenylation/N-dealkylative carbonylation of tertiary anilines.

    PubMed

    Shi, Renyi; Lu, Lijun; Zhang, Hua; Chen, Borui; Sha, Yuchen; Liu, Chao; Lei, Aiwen

    2013-09-27

    C-H/C-N activation: The first palladium/copper-catalyzed aerobic oxidative C-H alkenylation/N-dealkylative carbonylation of tertiary anilines has been developed. Various functional groups were tolerated and acrylic ester could also be suitable substrates. This transformation provided efficient and straightforward synthesis of biologically active 3-methyleneindolin-2-one derivatives from cheap and simple substrates. PMID:23946242

  9. Palladium-catalyzed carbonylative synthesis of benzoxazinones from N-(o-bromoaryl)amides using paraformaldehyde as the carbonyl source.

    PubMed

    Li, Wanfang; Wu, Xiao-Feng

    2014-11-01

    Carbonylation reactions have been widely used in organic synthesis. However, the manipulation of toxic and pressurized carbon monoxide limited their applications in organic laboratories. The search for alternative carbonyl sources as an important method for carbonylative organic synthesis is spreading. Herein, a series of substituted benzoxazinones were synthesized from N-(o-bromoaryl)amides by palladium-catalyzed carbonylation with paraformaldehyde as the carbonyl source, which is inexpensive, stable, and easy to use. Notably, this is the first example of using paraformaldehyde as the CO source in palladium-catalyzed carbonylative synthesis of heterocycles. PMID:25280209

  10. High Pressure Synthesis of Transition Metal Carbonyls.

    ERIC Educational Resources Information Center

    Hagen, A. P.; And Others

    1979-01-01

    Presents an experiment which uses readily available starting materials and inexpensive equipment for synthesis of transition metal carbonyls at 1000 atm and which is intended to give students experience in techniques used in research and industry. Safety precautions are emphasized. (Author/SA)

  11. Polyimides Containing Carbonyl and Ether Connecting Groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.; Havens, Stephen J.

    1987-01-01

    Semicrystallinity gives rise to tough, solvent-resistant polymers. New polyimides prepared from reaction of aromatic dianhydrides with new diamines containing carbonyl and ether connecting groups between aromatic rings. Damines prepared from reaction of 4-aminophenol with activated aromatic difluoro compounds in presence of potassium carbonate. These types of polymers have potential applications in molded products, films, adhesives, and composites.

  12. Waterpipe smoking: the role of humectants in the release of toxic carbonyls.

    PubMed

    Schubert, Jens; Heinke, Volkmar; Bewersdorff, Jana; Luch, Andreas; Schulz, Thomas G

    2012-08-01

    In recent years, the number of waterpipe smokers has increased substantially worldwide. Here, we present a study on the identification and quantification of seven carbonylic compounds including formaldehyde, acetaldehyde and acrolein in the mainstream smoke of the waterpipe. Smoking was conducted with a smoking machine, and carbonyls were scavenged from the smoke with two impingers containing an acidic solution of 2,4-dinitrophenylhydrazine. The derivatives were then analyzed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). For instance, during one waterpipe smoking session, up to 111 ± 12 μg formaldehyde could be detected. This value is about 5 times higher when compared to one 2R4F reference cigarette. We also found a distinct filter effect of the bowl water for all carbonyls investigated. Our data further demonstrate that increasing amounts of humectants in the unburned tobacco lowers the temperature in the waterpipe head during smoking, thereby resulting in decreasing levels of carbonyls in the smoke produced. Altogether, considerable amounts of toxic carbonyls are present in the waterpipe smoke, thus conferring a health risk to waterpipe smokers. PMID:22707202

  13. A Carbonyl Capture Approach for Profiling Oxidized Metabolites in Cell Extracts

    PubMed Central

    Mattingly, Stephanie J.; Xu, Tao; Nantz, Michael H.; Higashi, Richard M.; Fan, Teresa W.-M.

    2012-01-01

    Fourier-transform ion-cyclotron resonance mass spectrometry (FT-ICR-MS) detection of oxidized cellular metabolites is described using isotopologic, carbonyl-selective derivatizing agents that integrate aminooxy functionality for carbonyl capture, quaternary nitrogen for electrospray enhancement, and a hydrophobic domain for sample cleanup. These modular structural features enable rapid, sensitive analysis of complex mixtures of metabolite-derivatives by FT-ICR-MS via continuous nanoelectrospray infusion. Specifically, this approach can be used to globally assess levels of low abundance and labile aldehyde and ketone metabolites quantitatively and in high throughput manner. These metabolites are often key and unique indicators of various biochemical pathways and their perturbations. Analysis of lung adenocarcinoma A549 cells established a profile of carbonyl metabolites spanning multiple structural classes. We also demonstrate a procedure for metabolite quantification using pyruvate as a model analyte. PMID:23175637

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

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Okuzawa, K.; Aggarwal, S. G.; Irie, H.; Kanaya, Y.; Wang, Z.

    2013-01-01

    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 a clear sky condition. Using 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(trimethylsilyl)trifluoroacetamide (BSTFA), carbonyl derivatives were measured using a gas chromatography. The gaseous concentrations were obtained as follow: glycolaldehyde (range 0-1271 ng m-3, average 555 ng m-3), hydroxyacetone (0-707 ng m-3, 163 ng m-3), glyoxal (198-1396 ng m-3, 720 ng m-3), methylglyoxal (410-3170 ng m-3, 1376 ng m-3), n-nonanal (0-236 ng m-3, 71 ng m-3), and n-decanal (0-159 ng m-3, 31 ng m-3). These concentrations are among the highest ever reported in the urban and forest atmosphere. We found that gaseous carbonyls are more than 10 times more abundant than particulate carbonyls. 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.

  15. Transition-Metal-Catalyzed Carbonylation of Methyl Acetate.

    ERIC Educational Resources Information Center

    Polichnowski, S. W.

    1986-01-01

    Presents a study of the rhodium-catalyzed, ioding-promoted carbonylation of methyl acetate. This study provides an interesting contrast between the carbonylation of methyl acetate and the carbonylation of methanol when similar rhodium/iodine catalyst systems are used. (JN)

  16. Method for conversion of .beta.-hydroxy carbonyl compounds

    DOEpatents

    Lilga, Michael A.; White, James F.; Holladay, Johnathan E.; Zacher, Alan H.; Muzatko, Danielle S.; Orth, Rick J.

    2010-03-30

    A process is disclosed for conversion of salts of .beta.-hydroxy carbonyl compounds forming useful conversion products including, e.g., .alpha.,.beta.-unsaturated carbonyl compounds and/or salts of .alpha.,.beta.-unsaturated carbonyl compounds. Conversion products find use, e.g., as feedstock and/or end-use chemicals.

  17. Selective transformation of carbonyl ligands to organic molecules

    SciTech Connect

    Cutler, A.R.

    1992-05-12

    Studies on the carbonylation of ({eta}{sup 5}-indenyl)(L)(CO)Ru-R complexes (L = CO, PPh{sub 3}; R = CH{sub 2}OMe, CH{sub 3}) have been completed. Particularly noteworthy is that the methoxymethyl complexes readily transform to their acyl derivatives under mild conditions that leave their iron congeners inert towards CO. Surprisingly, even ({eta}{sup 5}-indenyl)(PPh{sub 3}){sub 2}Ru-CH{sub 3} carbonylates and gives ({eta}{sup 5}-indenyl)(PPh{sub 3})(CO)Ru-C(O)CH{sub 3}. Mechanistic studies on the non catalyzed'' hydrosilation of the manganese acyls (CO){sub 5}Mn-C(O)CH{sub 2}R (R = H, OCH{sub 3}, CH{sub 3}) with Et{sub 3}SiH and of cobalt acetyls (CO){sub 3}(PR{sub 3})CoC(O)CH{sub 3} with several monohydrosilanes have been completed. The cobalt acetyls cleanly give ethoxysilanes (not acetaldehyde), and the manganese acyls provide {alpha}-siloxyvinyl complexes Z-(CO){sub 5}Mn-C(OSiEt{sub 3})=CHR (R = H, CH{sub 3}, OCH{sub 3}). Carbonylation and protolytic cleavage of the latter generate pyruvoyl complexes (CO){sub 5}Mn-COCOR (R = CH{sub 3}, CH{sub 2}CH{sub 3}), formally the products of net double carbonylation'' sequences. Studies in progress are concerned with how manganese complexes as diverse as (CO){sub 5}Mn-Y (Y = C(O)R, R, BR - but not SiMe{sub 3} or Mn(CO){sub 5}) and ({eta}{sup 3}-C{sub 3}H{sub 5})Mn(CO){sub 2}L (but not CpMn(CO){sub 3} or CpMn(CO){sub 2}({eta}{sup 2}HSiR{sub 3})) function as efficient hydrosilation catalysts towards Cp(CO){sub 2}FeC(O)CH{sub 3}, for example. These reactions cleanly afford fully characterized {alpha}-siloxyethyl complexes Fp-CH(OSiR{sub 3})CH{sub 3} under conditions where typically Rh(1) hydrosilation catalysts are inactive. Several of these manganese complexes also catalytically hydrosilate organic esters, including lactones, to their ethers R-CH{sub 2}OR; these novel ester reductions occur quantitatively at room temperature and appear to be general in scope.

  18. Development of a photolabile carbonyl-protecting group toolbox.

    PubMed

    Yang, Haishen; Zhang, Xin; Zhou, Lei; Wang, Pengfei

    2011-04-01

    New salicyl alcohol derived photolabile carbonyl protecting groups have been developed, and the effect of substituents on the photochemical properties of photolabile protecting groups (PPGs) has been studied. The 3-(dimethylamino)phenyl groups at the α position prove to be important to the efficiency of the deprotection reactions, as shown in the photo reactions of the acetal 9. On the other hand, expansion of the salicyl alcohol's benzene skeleton to naphthalene does not improve the photochemical properties of PPGs. A neutral protecting protocol has been generalized to new PPGs with α,α-diaryl salicyl alcohol backbone. Thus, installation of PPGs onto aldehydes is readily achieved at 140 °C without using any other chemical reagents. These PPGs are stable under acidic conditions typical for hydrolyzing acetals and constitute orthogonal protecting groups with traditional 1,3-dioxane/1,3-dioxolane for carbonyl compounds. Highly efficient release of carbohydrate molecules is demonstrated, which can be potentially useful in site-specific release and immobilization of carbohydrates for preparation of high-density microarrays. With the enriched PPG toolbox, PPGs are divided into three subgroups based on their UV absorption profiles. PPGs from different subgroups can be sequentially removed by using different UV irradiation wavelengths. For PPGs absorbing UVA (λ >315 nm), photochemical deprotection can be carried out with sunlight in high yields. PMID:21370916

  19. Reactive Carbonyl Species In Vivo: Generation and Dual Biological Effects

    PubMed Central

    Semchyshyn, Halyna M.

    2014-01-01

    Reactive carbonyls are widespread species in living organisms and mainly known for their damaging effects. The most abundant reactive carbonyl species (RCS) are derived from oxidation of carbohydrates, lipids, and amino acids. Chemical modification of proteins, nucleic acids, and aminophospholipids by RCS results in cytotoxicity and mutagenicity. In addition to their direct toxicity, modification of biomolecules by RCS gives rise to a multitude of adducts and cross links that are increasingly implicated in aging and pathology of a wide range of human diseases. Understanding of the relationship between metabolism of RCS and the development of pathological disorders and diseases may help to develop effective approaches to prevent a number of disorders and diseases. On the other hand, constant persistence of RCS in cells suggests that they perform some useful role in living organisms. The most beneficial effects of RCS are their establishment as regulators of cell signal transduction and gene expression. Since RCS can modulate different biological processes, new tools are required to decipher the precise mechanisms underlying dual effects of RCS. PMID:24634611

  20. Environmental relevance of laboratory-derived kinetic models to predict trace metal bioaccumulation in gammarids: Field experimentation at a large spatial scale (France).

    PubMed

    Urien, N; Lebrun, J D; Fechner, L C; Uher, E; François, A; Quéau, H; Coquery, M; Chaumot, A; Geffard, O

    2016-05-15

    Kinetic models have become established tools for describing trace metal bioaccumulation in aquatic organisms and offer a promising approach for linking water contamination to trace metal bioaccumulation in biota. Nevertheless, models are based on laboratory-derived kinetic parameters, and the question of their relevance to predict trace metal bioaccumulation in the field is poorly addressed. In the present study, we propose to assess the capacity of kinetic models to predict trace metal bioaccumulation in gammarids in the field at a wide spatial scale. The field validation consisted of measuring dissolved Cd, Cu, Ni and Pb concentrations in the water column at 141 sites in France, running the models with laboratory-derived kinetic parameters, and comparing model predictions and measurements of trace metal concentrations in gammarids caged for 7 days to the same sites. We observed that gammarids poorly accumulated Cu showing the limited relevance of that species to monitor Cu contamination. Therefore, Cu was not considered for model predictions. In contrast, gammarids significantly accumulated Pb, Cd, and Ni over a wide range of exposure concentrations. These results highlight the relevance of using gammarids for active biomonitoring to detect spatial trends of bioavailable Pb, Cd, and Ni contamination in freshwaters. The best agreements between model predictions and field measurements were observed for Cd with 71% of good estimations (i.e. field measurements were predicted within a factor of two), which highlighted the potential for kinetic models to link Cd contamination to bioaccumulation in the field. The poorest agreements were observed for Ni and Pb (39% and 48% of good estimations, respectively). However, models developed for Ni, Pb, and to a lesser extent for Cd, globally underestimated bioaccumulation in caged gammarids. These results showed that the link between trace metal concentration in water and in biota remains complex, and underlined the limits of

  1. Oxidative carbonylation of amines to carbamates

    SciTech Connect

    Waller, F.J.

    1987-04-01

    Within the last several years, new technologies have appeared to replace phosgene for isocyanate manufacture. These include carbamate chemistries based upon dialkyl carbonate, reductive carbonylation of nitroaromatics, and oxidative carbonylation of amines. The carbamate ester can be handled safely and is reversibly cleaved to the isocyanate. The technology described here involves the preparation of both aliphatic and aromatic carbamates from an amine, alcohol, CO, oxidant, and a non-corrosive catalyst. The catalyst precursor is Pd(OAc){sub 2} and the oxidants are copper carboxylates or copper carboxylates and molecular oxygen. The latter represents a one-step carbamate synthesis with high catalyst activity, nearly quantitative conversions and alcohol selectivities greater than 90%. Operating temperatures and pressures are 80-110{degree}C and less than 500 psi, respectively. Experiments designed to probe the mechanism will be presented along with a discussion of novel (Cu(O{sub 2}CR){sub 2}){sub 2}R'NH{sub 2} complexes.

  2. Portable chemiluminescence detector for nickel carbonyl

    SciTech Connect

    Hikade, D.A.; Stedman, D.H.; Walega, J.G.

    1984-08-01

    This article describes a portable chemiluminescent detector for Ni(CO)/sub 4/ containing two innovative components, a self-contained carbon monoxide source which provides a greater degree of portability and a thermal differentiator to improve selectivity. The instrument is capable of measuring parts-per-billion levels of Ni(CO)/sub 4/, Fe(CO)/sub 5/, and NO. The instrument was used to measure carbonyl concentrations in the field and in cigarette smoke.

  3. Carbonyls and non-methane hydrocarbons at a rural mountain site in northeastern United States.

    PubMed

    Khwaja, Haider A; Narang, Amarjit

    2008-05-01

    Measurements of carbonyls and C(2)-C(6) non-methane hydrocarbons (NMHCs) were made in ambient air at a rural site at the summit of Whiteface Mountain (WFM) in New York State. Alkanes dominated in the samples, with ethane and propane making up about 55% of the total on a carbon-atom basis. Ethane, the longest-lived of the NMHCs, showed a mixing ratio in the range of 0.86-2.1 ppbv. Photochemical ageing analysis indicated an anthropogenic influence on the NMHC levels. The photochemical reactivity of the hydrocarbons, calculated in terms of propylene-equivalent concentration, was dominated by alkenes (propene and ethene), which accounted for 74% of the total NMHC sum. Air mass back-trajectories have been used to investigate the origin of the observed NMHCs and carbonyls. Higher concentrations were found when air masses arrived from the midwestern US corridor. Acetone was the most abundant species, comprising from 31% to 53% of the total detected carbonyls, followed by MEK (15-53%), HCHO (7-39%), and CH(3)CHO (7-19%). Average concentrations were determined to be 1.61 ppbv for CH(3)C(O)CH(3), 1.40 ppbv for MEK, 1.16 ppbv for HCHO, and 0.49 ppbv for CH(3)CHO. The variations in carbonyl concentrations were observed to follow patterns similar to variations in O(3) concentrations, typical of secondary products. Correlations and statistical analysis of the carbonyls and NMHCs were performed, and showed that most of the compounds derived from mixing and photochemical transformation of long-range transported pollutants from the major source areas. Ranking of the carbonyls with respect to removal of the OH radical showed HCHO to be the most important species, followed by CH(3)CHO, MEK, and CH(3)C(O)CH(3). PMID:18420251

  4. Carbonyl compounds generated from electronic cigarettes.

    PubMed

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-11-01

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon. PMID:25353061

  5. Carbonyl Compounds Generated from Electronic Cigarettes

    PubMed Central

    Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2014-01-01

    Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon. PMID:25353061

  6. Consumption of carbonyl sulphide (COS) by higher plant carbonic anhydrase (CA)

    NASA Astrophysics Data System (ADS)

    Protoschill-Krebs, G.; Wilhelm, C.; Kesselmeier, J.

    Carbonic anhydrase (CA), isolated from pea leaves, was found to consume carbonyl sulphide (COS), a climatic relevant trace gas in the atmosphere. The isolated enzyme, free of other carboxylases, showed a very high affinity towards this substrate. The experiments confirm that CA is the key enzyme for the consumption of COS in higher plants. Furthermore, the identification of this enzyme furthers our understanding of additional sinks for COS, which are needed to understand the balance of known global sources.

  7. Bisphenol A at concentrations relevant to human exposure enhances histamine and cysteinyl leukotriene release from bone marrow-derived mast cells.

    PubMed

    O'Brien, Edmund; Dolinoy, Dana C; Mancuso, Peter

    2014-01-01

    Bisphenol A (BPA), a monomer of polycarbonate plastics and epoxide resin, acts as an endocrine-active compound and has been shown to enhance the inflammatory response to allergen challenge. Previous reports in rodents have demonstrated that perinatal BPA exposure alters airway inflammation following sensitization and challenge to ovalbumin in juvenile and adult offspring. Additionally, a high concentration of BPA has been shown to enhance mediator release in mast cell lines. This study aimed to determine if short-term BPA exposure, at levels relevant to human exposure, enhances mast cell release of histamine and cysteinyl leukotrienes (CysLTs). Primary murine bone marrow-derived mast cells (BMMC) produced from the femurs of female C57BL/6 mice were stimulated with BPA or estradiol (E2) in vitro. It was observed that both BPA and E2 increased BMMC histamine release over a range of nanomolar concentrations (1-1000 nM). The estrogen receptor (ER) antagonist ICI 182,780 partially blocked the ability of E2, but not BPA, to elevate histamine release. BPA also increased CysLT release, which was not abrogated by ER inhibition. It was also observed that the ability of BPA to enhance histamine and CysLT release was inhibited by blocking the extracellular signal-regulated kinase (ERK) pathway with U0126 or by chelating extracellular calcium (Ca(2+)) using EGTA. In summary, these experiments are the first to demonstrate that acute BPA exposure enhances mast cell histamine and CysLT release in vitro--an effect that is not dependent on an ER-mediated mechanism. Instead, BPA-induced mast cell histamine and CysLT release may be mediated, in part, by the ERK pathway and extracellular Ca(2+) concentrations. These data suggest that exposure to BPA at levels relevant to human exposure may provoke an acute inflammatory response in atopic individuals via enhanced mast cell activation. PMID:23782309

  8. Zirconocene-Mediated Carbonylative Coupling of Grignard Reagents.

    PubMed

    Moss, Melissa; Han, Xinping; Ready, Joseph M

    2016-08-16

    Organozirconocenes are versatile synthetic intermediates that can undergo carbonylation to yield acyl anion equivalents. Zirconocene hydrochloride ([Cp2 ZrHCl]) is often the reagent of choice for accessing these intermediates but generates organozirconocenes only from alkenes and alkynes. This requirement eliminates a broad range of substrates. For example, organozirconocenes in which the zirconium center is bonded to an aromatic ring, a benzylic group, or an alkyl group that possesses a tertiary or quaternary carbon atom α to the carbon-zirconium bond can not be formed in this way. To provide more generalized access to acyl zirconium reagents, we explored the transmetalation of Grignard reagents with zirconocene dichloride under a CO atmosphere. This protocol generates acyl zirconium(IV) complexes that are inaccessible with the Schwartz reagent, including those derived from secondary and tertiary alkyl and aryl Grignard reagents. PMID:27410720

  9. Synthesis, characterization and bioactivities of N,O-carbonylated chitosan.

    PubMed

    Liu, Hongli; Liu, Xiaoli; Yue, Lin; Jiang, Qixing; Xia, Wenshui

    2016-10-01

    N,O-Carbonylated chitosan derivative (NTCS) was synthesized via oxidation and substitution reaction, respectively. The carboxyethylation of the polysaccharide was identified by Fourier transform infrared (FTIR), (1)H nuclear magnetic resonance (NMR), X-ray diffraction analysis (XRD), Zeta potential measurement and Thermogravimetric analysis (TGA). It is revealed that compared with chitosan (CS), NTCS exhibited an excellent solubility in distilled water, high in vitro bile acid binding capacity, as well as a low viscosity. The in vitro bile acid binding capacity reached 17.21mg/g, which was 4.5-fold higher than that of CS. The results suggest that NTCS may be useful as a potential functional food supplement in food industry or a key ingredient in the pharmaceutical industry. These findings provide important supports for developing new food additive, and expand the scope of application of CS in the food industry. PMID:27189702

  10. Infrapatellar Fat Pad-Derived Stem Cells Maintain Their Chondrogenic Capacity in Disease and Can be Used to Engineer Cartilaginous Grafts of Clinically Relevant Dimensions

    PubMed Central

    Liu, Yurong; Buckley, Conor Timothy; Almeida, Henrique V.; Mulhall, Kevin J.

    2014-01-01

    A therapy for regenerating large cartilaginous lesions within the articular surface of osteoarthritic joints remains elusive. While tissue engineering strategies such as matrix-assisted autologous chondrocyte implantation can be used in the repair of focal cartilage defects, extending such approaches to the treatment of osteoarthritis will require a number of scientific and technical challenges to be overcome. These include the identification of an abundant source of chondroprogenitor cells that maintain their chondrogenic capacity in disease, as well as the development of novel approaches to engineer scalable cartilaginous grafts that could be used to resurface large areas of damaged joints. In this study, it is first demonstrated that infrapatellar fat pad-derived stem cells (FPSCs) isolated from osteoarthritic (OA) donors possess a comparable chondrogenic capacity to FPSCs isolated from patients undergoing ligament reconstruction. In a further validation of their functionality, we also demonstrate that FPSCs from OA donors respond to the application of physiological levels of cyclic hydrostatic pressure by increasing aggrecan gene expression and the production of sulfated glycosaminoglycans. We next explored whether cartilaginous grafts could be engineered with diseased human FPSCs using a self-assembly or scaffold-free approach. After examining a range of culture conditions, it was found that continuous supplementation with both transforming growth factor-β3 (TGF-β3) and bone morphogenic protein-6 (BMP-6) promoted the development of tissues rich in proteoglycans and type II collagen. The final phase of the study sought to scale-up this approach to engineer cartilaginous grafts of clinically relevant dimensions (≥2 cm in diameter) by assembling FPSCs onto electrospun PLLA fiber membranes. Over 6 weeks in culture, it was possible to generate robust, flexible cartilage-like grafts of scale, opening up the possibility that tissues engineered using FPSCs

  11. Infrapatellar fat pad-derived stem cells maintain their chondrogenic capacity in disease and can be used to engineer cartilaginous grafts of clinically relevant dimensions.

    PubMed

    Liu, Yurong; Buckley, Conor Timothy; Almeida, Henrique V; Mulhall, Kevin J; Kelly, Daniel John

    2014-11-01

    A therapy for regenerating large cartilaginous lesions within the articular surface of osteoarthritic joints remains elusive. While tissue engineering strategies such as matrix-assisted autologous chondrocyte implantation can be used in the repair of focal cartilage defects, extending such approaches to the treatment of osteoarthritis will require a number of scientific and technical challenges to be overcome. These include the identification of an abundant source of chondroprogenitor cells that maintain their chondrogenic capacity in disease, as well as the development of novel approaches to engineer scalable cartilaginous grafts that could be used to resurface large areas of damaged joints. In this study, it is first demonstrated that infrapatellar fat pad-derived stem cells (FPSCs) isolated from osteoarthritic (OA) donors possess a comparable chondrogenic capacity to FPSCs isolated from patients undergoing ligament reconstruction. In a further validation of their functionality, we also demonstrate that FPSCs from OA donors respond to the application of physiological levels of cyclic hydrostatic pressure by increasing aggrecan gene expression and the production of sulfated glycosaminoglycans. We next explored whether cartilaginous grafts could be engineered with diseased human FPSCs using a self-assembly or scaffold-free approach. After examining a range of culture conditions, it was found that continuous supplementation with both transforming growth factor-β3 (TGF-β3) and bone morphogenic protein-6 (BMP-6) promoted the development of tissues rich in proteoglycans and type II collagen. The final phase of the study sought to scale-up this approach to engineer cartilaginous grafts of clinically relevant dimensions (≥2 cm in diameter) by assembling FPSCs onto electrospun PLLA fiber membranes. Over 6 weeks in culture, it was possible to generate robust, flexible cartilage-like grafts of scale, opening up the possibility that tissues engineered using FPSCs

  12. A Systematic Evaluation of Integration Free Reprogramming Methods for Deriving Clinically Relevant Patient Specific Induced Pluripotent Stem (iPS) Cells

    PubMed Central

    Goh, Pollyanna A.; Caxaria, Sara; Casper, Catharina; Rosales, Cecilia; Warner, Thomas T.; Coffey, Pete J.; Nathwani, Amit C.

    2013-01-01

    A systematic evaluation of three different methods for generating induced pluripotent stem (iPS) cells was performed using the same set of parental cells in our quest to develop a feeder independent and xeno-free method for somatic cell reprogramming that could be transferred into a GMP environment. When using the BJ fibroblast cell line, the highest reprogramming efficiency (1.89% of starting cells) was observed with the mRNA based method which was almost 20 fold higher than that observed with the retrovirus (0.2%) and episomal plasmid (0.10%) methods. Standard characterisation tests did not reveal any differences in an array of pluripotency markers between the iPS lines derived using the various methods. However, when the same methods were used to reprogram three different primary fibroblasts lines, two derived from patients with rapid onset parkinsonism dystonia and one from an elderly healthy volunteer, we consistently observed higher reprogramming efficiencies with the episomal plasmid method, which was 4 fold higher when compared to the retroviral method and over 50 fold higher than the mRNA method. Additionally, with the plasmid reprogramming protocol, recombinant vitronectin and synthemax® could be used together with commercially available, fully defined, xeno-free essential 8 medium without significantly impacting the reprogramming efficiency. To demonstrate the robustness of this protocol, we reprogrammed a further 2 primary patient cell lines, one with retinosa pigmentosa and the other with Parkinsons disease. We believe that we have optimised a simple and reproducible method which could be used as a starting point for developing GMP protocols, a prerequisite for generating clinically relevant patient specific iPS cells. PMID:24303062

  13. Carbonyl Emissions from Gasoline and Diesel Motor Vehicles

    SciTech Connect

    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.

  14. Translating Textiles to Tissue Engineering: Creation and Evaluation of Microporous, Biocompatible, Degradable Scaffolds Using Industry Relevant Manufacturing Approaches and Human Adipose Derived Stem Cells

    PubMed Central

    Haslauer, Carla M.; Avery, Matthew R.; Pourdeyhimi, Behnam; Loboa, Elizabeth G.

    2014-01-01

    Polymeric scaffolds have emerged as a means of generating three-dimensional tissues, such as for the treatment of bone injuries and non-unions. In this study, a fibrous scaffold was designed using the biocompatible, degradable polymer poly-lactic acid in combination with a water dispersible sacrificial polymer, EastONE. Fibers were generated via industry relevant, facile scale-up melt-spinning techniques with an islands-in-the-sea geometry. Following removal of EastONE, a highly porous fiber remained possessing 12 longitudinal channels and pores throughout all internal and external fiber walls. Weight loss and surface area characterization confirmed the generation of highly porous fibers as observed via focused ion beam/scanning electron microscopy. Porous fibers were then knit into a three-dimensional scaffold and seeded with human adipose-derived stem cells (hASC). Confocal microscopy images confirmed hASC attachment to the fiber walls and proliferation throughout the knit structure. Quantification of cell-mediated calcium accretion following culture in osteogenic differentiation medium confirmed hASC differentiation throughout the porous constructs. These results suggest incorporation of a sacrificial polymer within islands-in-the-sea fibers generates a highly porous scaffold capable of supporting stem cell viability and differentiation with the potential to generate large three-dimensional constructs for bone regeneration and/or other tissue engineering applications. PMID:25229198

  15. Translating textiles to tissue engineering: Creation and evaluation of microporous, biocompatible, degradable scaffolds using industry relevant manufacturing approaches and human adipose derived stem cells.

    PubMed

    Haslauer, Carla M; Avery, Matthew R; Pourdeyhimi, Behnam; Loboa, Elizabeth G

    2015-07-01

    Polymeric scaffolds have emerged as a means of generating three-dimensional tissues, such as for the treatment of bone injuries and nonunions. In this study, a fibrous scaffold was designed using the biocompatible, degradable polymer poly-lactic acid in combination with a water dispersible sacrificial polymer, EastONE. Fibers were generated via industry relevant, facile scale-up melt-spinning techniques with an islands-in-the-sea geometry. Following removal of EastONE, a highly porous fiber remained possessing 12 longitudinal channels and pores throughout all internal and external fiber walls. Weight loss and surface area characterization confirmed the generation of highly porous fibers as observed via focused ion beam/scanning electron microscopy. Porous fibers were then knit into a three-dimensional scaffold and seeded with human adipose-derived stem cells (hASC). Confocal microscopy images confirmed hASC attachment to the fiber walls and proliferation throughout the knit structure. Quantification of cell-mediated calcium accretion following culture in osteogenic differentiation medium confirmed hASC differentiation throughout the porous constructs. These results suggest incorporation of a sacrificial polymer within islands-in-the-sea fibers generates a highly porous scaffold capable of supporting stem cell viability and differentiation with the potential to generate large three-dimensional constructs for bone regeneration and/or other tissue engineering applications. PMID:25229198

  16. Hepatocellular carcinoma protein carbonylation in virus C and metabolic syndrome patients.

    PubMed

    Martin, Fernando Ariel; Mebarki, Mouniya; Paradis, Valérie; Friguet, Bertrand; Radman, Miroslav

    2014-10-01

    Metabolic syndrome (MS) is becoming the leading cause of chronic liver diseases worldwide. Hepatocellular carcinoma (HCC) development in MS is peculiar compared to other chronic liver diseases. Carbohydrate and lipid metabolic imbalance in MS increase reactive oxygen species damaging proteins. In the present work we study the difference in protein oxidative damage (carbonylation) in human HCC derived from virus C infection (VHC) and from MS (MS_HCC) as the only subjacent cause. We selected a patient cohort containing of 10 non-tumoral and 10 tumoral liver resections in each study group (virus C and MS HCC) based on clinical patient history and histological parameters. Protein samples were labeled to saturation using CF 647-hydrazide™ dye. This approach allows us to perform carbonyl detection alongside with a DIGE experiment. We detected a total of 1184 spots with 36 differentially expressed proteins and 47 spots differentially carbonylated between VHC and MS_HCC (fold change >1.5, p<0.05). VHC up-regulated proteins are involved in signaling pathways related to cancer development such as signaling by EGFR, Wnt, Cdc20 and cell cycle. Further, up-regulated proteins in MS HCC, are implicated in metabolism of carbohydrates and amino acids. Differential carbonylation analysis between VHC and MS_HCC showed protein damage in proteins such as glucose phosphate isomerase, isocitrate dehydrogenase, and 3-ketoacyl-CoA thiolase. Higher protein carbonylation in MS_HCC samples was observed in proteins involved in redox response and lipid metabolism. In conclusion, the observed difference in protein oxidative damage between MS and Virus C derived carcinoma could account for the different cancer development pathway. PMID:26461368

  17. Infrared spectroscopy of mass-selected metal carbonyl cations

    NASA Astrophysics Data System (ADS)

    Ricks, A. M.; Reed, Z. E.; Duncan, M. A.

    2011-04-01

    Metal carbonyl cations of the form M(CO)n+ are produced in a molecular beam by laser vaporization in a pulsed nozzle source. These ions, and their corresponding rare gas atom "tagged" analogs, M(CO)n(RG)m+, are studied with mass-selected infrared photodissociation spectroscopy in the carbonyl stretching region and with density functional theory computations. The number of infrared-active bands, their frequency positions, and their relative intensities provide distinctive patterns allowing determination of the geometries and electronic structures of these complexes. Cobalt penta carbonyl and manganese hexacarbonyl cations are compared to isoelectronic iron pentacarbonyl and chromium hexacarbonyl neutrals. Gold and copper provide examples of "non-classical" carbonyls. Seven-coordinate carbonyls are explored for the vanadium group metal cations (V +, Nb + and Ta +), while uranium cations provide an example of an eight-coordinate carbonyl.

  18. Chemoselective Intramolecular Carbonyl Ylide Formation through Electronically Differentiated Malonate Diesters.

    PubMed

    Nakhla, Mina C; Lee, Che-Wah; Wood, John L

    2015-12-01

    A method for chemoselective carbonyl ylide formation utilizing the Rh(II) catalyzed decomposition of electronically differentiated diazo malonates is disclosed. Treatment of ethyl, trifluoro ethyl diazo malonate with a Rh(II) catalyst selectively forms a carbonyl ylide from the relatively electron rich ethyl ester. This carbonyl ylide can be trapped by various alkynes giving highly functionalized oxabicyclic compounds in a chemo-, regio-, and diastereoselective fashion. PMID:26584509

  19. Acute inhalation toxicity of carbonyl sulfide

    SciTech Connect

    Benson, J.M.; Hahn, F.F.; Barr, E.B.

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  20. A computational method to predict carbonylation sites in yeast proteins.

    PubMed

    Lv, H Q; Liu, J; Han, J Q; Zheng, J G; Liu, R L

    2016-01-01

    Several post-translational modifications (PTM) have been discussed in literature. Among a variety of oxidative stress-induced PTM, protein carbonylation is considered a biomarker of oxidative stress. Only certain proteins can be carbonylated because only four amino acid residues, namely lysine (K), arginine (R), threonine (T) and proline (P), are susceptible to carbonylation. The yeast proteome is an excellent model to explore oxidative stress, especially protein carbonylation. Current experimental approaches in identifying carbonylation sites are expensive, time-consuming and limited in their abilities to process proteins. Furthermore, there is no bioinformational method to predict carbonylation sites in yeast proteins. Therefore, we propose a computational method to predict yeast carbonylation sites. This method has total accuracies of 86.32, 85.89, 84.80, and 86.80% in predicting the carbonylation sites of K, R, T, and P, respectively. These results were confirmed by 10-fold cross-validation. The ability to identify carbonylation sites in different kinds of features was analyzed and the position-specific composition of the modification site-flanking residues was discussed. Additionally, a software tool has been developed to help with the calculations in this method. Datasets and the software are available at https://sourceforge.net/projects/hqlstudio/ files/CarSpred.Y/. PMID:27420944

  1. Copper-catalyzed one-pot trifluoromethylation/aryl migration/carbonyl formation with homopropargylic alcohols.

    PubMed

    Gao, Pin; Shen, Yong-Wen; Fang, Ran; Hao, Xin-Hua; Qiu, Zi-Hang; Yang, Fan; Yan, Xiao-Biao; Wang, Qiang; Gong, Xiang-Jun; Liu, Xue-Yuan; Liang, Yong-Min

    2014-07-14

    A novel copper-catalyzed one-pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF3-containing 3-butenal or 3-buten-1-one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4-aryl migration proceeds through a radical pathway. PMID:24938432

  2. FT-IR quantification of the carbonyl functional group in aqueous-phase secondary organic aerosol from phenols

    NASA Astrophysics Data System (ADS)

    George, Kathryn M.; Ruthenburg, Travis C.; Smith, Jeremy; Yu, Lu; Zhang, Qi; Anastasio, Cort; Dillner, Ann M.

    2015-01-01

    Recent findings suggest that secondary organic aerosols (SOA) formed from aqueous-phase reactions of some organic species, including phenols, contribute significantly to particulate mass in the atmosphere. In this study, we employ a Fourier transform infrared (FT-IR) spectroscopic technique to identify and quantify the functional group makeup of phenolic SOA. Solutions containing an oxidant (hydroxyl radical or 3,4-dimethoxybenzaldehyde) and either one phenol (phenol, guaiacol, or syringol) or a mixture of phenols mimicking softwood or hardwood emissions were illuminated to make SOA, atomized, and collected on a filter. We produced laboratory standards of relevant organic compounds in order to develop calibrations for four functional groups: carbonyls (Cdbnd O), saturated C-H, unsaturated C-H and O-H. We analyzed the SOA samples with transmission FT-IR to identify and determine the amounts of the four functional groups. The carbonyl functional group accounts for 3-12% of the SOA sample mass in single phenolic SOA samples and 9-14% of the SOA sample mass in mixture samples. No carbonyl functional groups are present in the initial reactants. Varying amounts of each of the other functional groups are observed. Comparing carbonyls measured by FT-IR (which could include aldehydes, ketones, esters, and carboxylic acids) with eight small carboxylic acids measured by ion chromatography indicates that the acids only account for an average of 20% of the total carbonyl reported by FT-IR.

  3. Identification of carbonylated lipids from different phospholipid classes by shotgun and LC-MS lipidomics.

    PubMed

    Ni, Zhixu; Milic, Ivana; Fedorova, Maria

    2015-07-01

    Oxidized lipids play a significant role in the pathogenesis of numerous oxidative stress-related human disorders, such as atherosclerosis, obesity, inflammation, and autoimmune diseases. Lipid peroxidation, induced by reactive oxygen and nitrogen species, yields a high variety of modified lipids. Among them, carbonylated lipid peroxidation products (oxoLPP), formed by oxidation of the fatty acid moiety yielding aldehydes or ketones (carbonyl groups), are electrophilic compounds that are able to modify nucleophilic substrates like proteins, nucleic acid, and aminophospholipids. Some carbonylated phosphatidylcholines possess even pro-inflammatory activities. However, little is known about oxoLPP derived from other phospholipid (PL) classes. Here, we present a new analytical strategy based on the mass spectrometry (MS) of PL-oxoLPP derivatized with 7-(diethylamino)coumarin-3-carbohydrazide (CHH). Shotgun MS revealed many oxoLPP derived from in vitro oxidized glycerophosphatidylglycerols (PG, 31), glycerophosphatidylcholine (PC, 23), glycerophosphatidylethanolamine (PE, 34), glycerophosphatidylserines (PS, 7), glycerophosphatidic acids (PA, 17), and phosphatidylinositiolphosphates (PIP, 6) vesicles. This data were used to optimize LipidXplorer-assisted identification, and a python-based post-processing script was developed to increase both throughput and accuracy. When applied to full lipid extracts from rat primary cardiomyocytes treated with peroxynitrite donor SIN-1, ten PL-bound oxoLPP were unambiguously identified by LC-MS, including two PC-, two PE-, one PG-, two PS-, and three PA-derived species. Some of the well-known carbonylated PC were detected, while most PL-oxoLPP were shown for the first time. PMID:25701423

  4. Studies relevant to the catalytic activation of carbon monoxide

    SciTech Connect

    Ford, P.C.

    1992-06-04

    Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

  5. Carbonyl emissions in diesel and biodiesel exhaust

    NASA Astrophysics Data System (ADS)

    Machado Corrêa, Sérgio; Arbilla, Graciela

    With the use of biodiesel in clear growth, it is important to quantify any potential emission benefits or liabilities of this fuel. Several researches are available concerning the regulated emissions of biodiesel/diesel blends, but there is a lack of information about non-regulated emissions. In a previous paper [Corrêa, S.M., Arbilla, G., 2006. Emissões de formaldeído e acetaldeído de misturas biodiesel/diesel. Periódico Tchê Química, 3, 54-68], the emissions of aromatic hydrocarbons were reported. In this work, seven carbonyl emissions (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, butyraldehyde, and benzaldehyde) were evaluated by a heavy-duty diesel engine fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5), 10% (B10), and 20% (B20). The tests were conducted using a six cylinder heavy-duty engine, typical of the Brazilian fleet of urban buses, in a steady-state condition under 1000, 1500, and 2000 rpm. The exhaust gases were diluted nearly 20 times and the carbonyls were sampled with SiO 2-C18 cartridges, impregnated with acid solution of 2,4-dinitrophenylhydrazine. The chemical analyses were performed by high performance liquid chromatography using UV detection. Using average values for the three modes of operation (1000, 1500, and 2000 rpm) benzaldehyde showed a reduction on the emission (-3.4% for B2, -5.3% for B5, -5.7% for B10, and -6.9% for B20) and all other carbonyls showed a significative increase: 2.6, 7.3, 17.6, and 35.5% for formaldehyde; 1.4, 2.5, 5.4, and 15.8% for acetaldehyde; 2.1, 5.4, 11.1, and 22.0% for acrolein+acetone; 0.8, 2.7, 4.6, and 10.0% for propionaldehyde; 3.3, 7.8, 16.0, and 26.0% for butyraldehyde.

  6. The Hydrolysis of Carbonyl Sulfide at Low Temperature: A Review

    PubMed Central

    Zhao, Shunzheng; Yi, Honghong; Tang, Xiaolong; Jiang, Shanxue; Gao, Fengyu; Zhang, Bowen; Zuo, Yanran; Wang, Zhixiang

    2013-01-01

    Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transition metal oxides, rare earth metal oxides, mixed metal oxides, and nanometal oxides. The catalytic hydrolysis of COS is a first-order reaction with respect to carbonyl sulfide, while the reaction order of water changes as the reaction conditions change. The controlling steps are also different because the reaction conditions such as concentration of carbonyl sulfide, reaction temperature, water-air ratio, and reaction atmosphere are different. The hydrolysis of carbonyl sulfide is base-catalyzed reaction, and the force of the base site has an important effect on the hydrolysis of carbonyl sulfide. PMID:23956697

  7. Carbonyl Emissions From Oil and Gas Production Facilities

    NASA Astrophysics Data System (ADS)

    Lyman, S. N.; O'Neil, T.; Tran, T.

    2015-12-01

    A number of recent studies have targeted emissions of methane and other hydrocarbons from oil and gas exploration and production activity. These measurements are greatly increasing understanding of the atmospheric impacts of oil and gas development. Very few measurements exist, however, of emissions of formaldehyde and other carbonyls from oil and gas equipment. Carbonyls are toxic and serve as important ozone precursors, especially during winter ozone episodes in places like Utah's Uintah Basin. Current air quality models are only able to reproduce observed high wintertime ozone if they incorporate emissions inventories with very high carbonyl emissions. We measured carbonyl emissions from oil and gas equipment and facilities—including glycol dehydrators, liquid storage tanks, raw gas leaks, raw gas-burning engines, and produced water surface impoundments—in Rocky Mountain oil and gas fields. Carbonyl emissions from raw gas were below detection, but emissions of formaldehyde, acetaldehyde, and other carbonyls were detected from liquid storage tanks, glycol dehydrators, and other oil and gas equipment. In some cases, carbonyls may be formed from the degradation of methanol and other chemicals used in oil and gas production, but the collected data provide evidence for other non-combustion formation pathways. Raw gas-burning engines also emitted carbonyls. Emissions from all measured sources were a small fraction of total volatile organic compound emissions. We incorporated our measurements into an emissions inventory, used that inventory in an air quality model (WRF-SMOKE-CAMx), and were unable to reproduce observed high wintertime ozone. This could be because (1) emission sources we have not yet measured, including compressors, gas processing plants, and others, are large; (2) non-carbonyl emissions, especially those that quickly degrade into carbonyls during photochemical processing, are underestimated in the inventory; or (3) the air quality model is unable

  8. Detection of carbonyl fluoride in the stratosphere

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Park, J. H.; Russell, J. M., III; Zander, R.; Brown, L. R.; Farmer, C. B.; Norton, R. H.; Raper, O. F.

    1986-01-01

    Infrared solar absorption spectra of the stratosphere recorded at a resolution of 0.01/cm by the ATMOS (Atmospheric Trace Molecule Spectroscopy) instrument from onboard Spacelab 3 (04/30 to 05/6/85) have revealed the existence of many previously unobserved absorption features in the 1925 to 1960/cm and 1249 to 1255/cm regions and one at 774/cm. On the basis of comparisons with laboratory spectra, these features have been identified as belonging to the nu1, nu4, and nu6 bands of carbonyl fluoride, respectively. Volume mixing ratios of COF2 between 17 and 40 km have been deduced from analysis of the nu1 and nu6 bands.

  9. Absorption of carbonyl sulfide in aqueous methyldiethanolamine

    SciTech Connect

    Al-Ghawas, H.A.; Ruiz-Ibanez, G.; Sandall, O.C. )

    1988-01-01

    The absorption of carbonyl sulfide in aqueous methyldiethanolamine (MDEA) was studied over a range of temperatures and MDEA concentrations. MDEA is commonly used for selective absorption of hydrogen sulfide in the presence of carbon dioxide. However, sulfur in the form of COS may also be present and it is necessary that estimates of absorption rates of this compound be made. The objective of this study is to determine the physiochemical properties needed to predict COS absorption rates in aqueous MDEA. Free gas solubility and the diffusivity of COS in MDEA solutions were measured over the temperature range 15 to 40{sup 0}C for MDEA concentrations up to 30 weight per cent using the nitrous oxide analogy method. Solubilities were measured volumetrically in an equilibrium cell and diffusivities were measured using a laminar liquid jet absorber. The kinetics of the reaction between COS and MDEA were studied by measuring absorption rates in a single wetted-sphere absorber.

  10. Metal-free carbonylations by photoredox catalysis.

    PubMed

    Majek, Michal; Jacobi von Wangelin, Axel

    2015-02-01

    The synthesis of benzoates from aryl electrophiles and carbon monoxide is a prime example of a transition-metal-catalyzed carbonylation reaction which is widely applied in research and industrial processes. Such reactions proceed in the presence of Pd or Ni catalysts, suitable ligands, and stoichiometric bases. We have developed an alternative procedure that is free of any metal, ligand, and base. The method involves a redox reaction driven by visible light and catalyzed by eosin Y which affords alkyl benzoates from arene diazonium salts, carbon monoxide, and alcohols under mild conditions. Tertiary esters can also be prepared in high yields. DFT calculations and radical trapping experiments support a catalytic photoredox pathway without the requirement for sacrificial redox partners. PMID:25414135

  11. Atmospheric carbonyl sulfide exchange in bog microcosms

    SciTech Connect

    Fried, A.; Klinger, L.F.; Erickson, D.J. III )

    1993-01-22

    Measurements of Carbonyl sulfide (OCS) fluxes were carried out on bog microcosms using chamber sampling and tunable diode laser analysis. Intact bog microcosms (vascular plants, mosses, and peat) removed ambient levels of OCS in the light and dark with rates from [minus]2.4 to [minus]8.1 ng S min[sup [minus]1] m[sup [minus]2]. Peat and peat plus mosses emitted OCS in the light with rates of 17.4 and 10.9 ng S min[sup [minus]1] m[sup [minus]2], respectively. In the dark, the mosses apparently removed OCS at a rate equivalent to the peat emissions. A 3-D numerical tracer model using this data indicated that boreal bog ecosystems remove at most 1% of ambient OCS, not sufficient to account for an observed OCS depletion in boreal air masses. 13 refs., 1 fig., 1 tab.

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

    PubMed

    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, p<0.01) between the concentrations of the low molecular-weight carbonyl compounds (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. PMID:20692096

  13. Reductive carbonylation of aromatic nitro compounds

    SciTech Connect

    Wehman, P.; Kamer, P.C.J.; Leeuwen, P.W.N.M. van

    1995-12-31

    In the reductive carbonylation of aromatic nitro compounds carbamates and isocyanates are prepared through a direct reaction between the nitro group and CO under the influence of a catalyst. This route avoids the major disadvantages of the traditional process for the production of the industrially important isocyanates and carbamates. The authors have developed a stable, active, and rather selective homogeneous palladium catalyst for the reductive carbonylation of the nitro substrate. Best results were obtained with Pd-phenanthroline complexes in which the ligands bear moderately donating substituents. Noncoordinating anions in the catalyst complex are clearly preferable. The highest activity was reached with the Pd(4,7-Me{sub 2}-1,10-phen){sub 2}(OTf){sub 2} catalyst complex (t.o.f. = 311 mol/mol/h, selectivity toward the desired carbamate = 84%). With the Pd(1,10-phenanthroline){sub 2}(OTf){sub 2} catalyst complex, the authors studied the scope of the reaction in order to prepare a wide range of functionalized carbamates for the fine chemistry. During this study, it was found that a remarkable improvement of the catalytic activity and selectivity on addition of a benzoic acid (t.o.f. > 365 mol/mol/h, selectivity toward carbamate = 94%). In the presence of 4-chlorobenzoic acid even aromatic dinitro compounds could be converted easily, resulting in the best results reported ever for the conversion of 1,4-dinitrobenzene into the corresponding dicarbamate (t.o.f. = 73 mol/mol/h, selectivity toward the dicarbamate = 86%).

  14. [Assessment of the concentrations of carbonylated proteins and carbonyl reductase enzyme in mexican women with breast cancer: A pilot study].

    PubMed

    Gutiérrez-Salinas, José; García-Ortiz, Liliana; Mondragón-Terán, Paul; Hernández-Rodríguez, Sergio; Ramírez-García, Sotero; Núñez-Ramos, Norma Rebeca

    2016-01-01

    Oxidative stress could promote the development of cancer and implicate carbonylated proteins in the carcinogenic process. The goal of this study was to assess the concentrations of carbonylated proteins and carbonyl reductase enzyme in women with breast cancer and determine whether these markers were possible indicators of tissue damage caused by the disease. A total of 120 healthy women and 123 women with a diagnosis of breast cancer were included. The concentration of carbonylated proteins in plasma and the concentration of carbonyl reductase enzyme in leukocytes were determined using the ELISA assay. There was a 3.76-fold increase in the amount of carbonylated proteins in the plasma from the patient group compared with healthy control group (5±3.27 vs. 1.33±2.31 nmol carbonyls/mg protein; p<0.05). Additionally, a 60% increase in the carbonyl reductase enzyme was observed in the patient group compared with the healthy control group (3.27±0.124 vs. 2.04±0.11 ng/mg protein; p<0.05). A positive correlation (r=0.95; p<0.001) was found between both measurements. These results suggest the presence of tissue damage produced by cancer; therefore, these parameters could be used to indicate tissue damage in cancer patients. PMID:26927639

  15. Relevancy 101

    NASA Technical Reports Server (NTRS)

    Lynnes, Chris; Newman, Doug

    2016-01-01

    Where we present an overview on why relevancy is a problem, how important it is and how we can improve it. The topic of relevancy is becoming increasingly important in earth data discovery as our audience is tuned to the accuracy of standard search engines like Google.

  16. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    NASA Astrophysics Data System (ADS)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  17. UHPLC separation with MS analysis for eight carbonyl compounds in mainstream tobacco smoke.

    PubMed

    Miller, John H; Gardner, William P; Gonzalez, Ricardo R

    2010-01-01

    A method to quantify eight carbonyl compounds in mainstream cigarette smoke is presented using ultra-high pressure liquid chromatography (UHPLC). The combination of UHPLC and mass spectrometry (UHPLC-MS) dramatically reduces analysis times as compared to the current in-house high-performance liquid chromatography (HPLC)-UV method. In addition, improved detector selectivity and peak resolution are observed. Sample analysis times are reduced from 47 min with HPLC-UV to less than 5 min using this improved method. Atmospheric pressure chemical ionization, atmospheric pressure photo ionization, and electrospray ionization are directly compared to evaluate ionization potential and linear response range for the carbonyl 2,4-dinitrophenylhydrazine derivatives. Smoke extracts from three standard smoking protocols are analyzed by both UHPLC-MS and HPLC-UV for method comparison purposes. PMID:20056029

  18. Solid Carbonyl Sulphide (OCS) in W33A

    NASA Technical Reports Server (NTRS)

    Palumbo, M. E.; Tielens, A. G. G. M.; Tokunaga, A. T.

    1995-01-01

    We present ground-based observations of the 2041/cm (4.9 micrometer) absorption feature toward the deeply embedded protostar W33A. We attribute this interstellar feature to solid carbonyl sulphide (OCS) embedded in icy grain mantles along the line of sight. We have made an extensive laboratory study of the infrared characteristics of OCS in various ice mixtures. Studies of the 2041/cm band of solid OCS and solid mixtures containing OCS show that its shape and peak position are sensitive to the molecular environment of the OCS molecule. Mie scattering calculations show that the peak position and profile of the OCS band depend on the shape and size of the absorbing grain when the OCS concentration is larger than 0.05. For lower OCS concentrations, laboratory-measured bulk spectra agree very well with the absorption spectra of small grains. We have compared the observed feature with laboratory and theoretical spectra of astrophysically relevant mixtures. The best agreement is obtained for mixtures with traces of OCS in a methanol-rich matrix. This would suggest the presence of independent grain components and in particular of a minor fraction of methanol-rich icy grain mantles in which OCS is embedded. From the strength of the absorption feature we deduce a OCS/H 20 ratio, along the line of sight, of 4 x 10(exp -4).

  19. Solid Carbonyl Sulphide (OCS) in W33A

    NASA Technical Reports Server (NTRS)

    Palumbo, M. E.; Tielens, A. G. G. M.; Tokunaga, A. T.

    1995-01-01

    We present ground-based observations of the 2041 cm(exp -1) (4.9 mm) absorption feature toward the deeply embedded protostar W33A. We attribute this interstellar feature to solid carbonyl sulphide (OCS) embedded in icy grain mantles along the line of sight. We have made an extensive laboratory study of the infrared characteristics of OCS in various ice mixtures. Studies of the 2041 cm(exp -1) band of solid OCS and solid mixtures containing OCS show that its shape and peak position are sensitive to the molecular environment of the OCS molecule. Mie scattering calculations show that the peak position and profile of the OCS band depend on the shape and size of the absorbing grain when the OCS concentration is larger than 0.05. For lower OCS concentrations, laboratory-measured bulk spectra agree very well with the absorption spectra of small grains. We have compared the observed feature with laboratory and theoretical spectra of astrophysically relevant mixtures. The best agreement is obtained for mixtures with traces of OCS in a methanol-rich matrix. This would suggest the presence of independent grain components and in particular of a minor fraction of methanol-rich icy grain mantles in which OCS is embedded. From the strength of the absorption feature we deduce a OCS/H2O ratio, along the line of sight, of 4 x 10(exp -4).

  20. Aldol Condensation of Volatile Carbonyl Compounds in Acidic Aerosols

    NASA Astrophysics Data System (ADS)

    Noziere, B.; Esteve, W.

    2003-12-01

    Reactions of volatile organic compounds in acidic aerosols have been shown recently to be potentially important for organic aerosol formation and growth. Aldol condensation, the acid-catalyzed polymerization of carbonyl compounds, is a likely candidate to enhance the flux of organic matter from the gas phase to the condensed phase in the atmosphere. Until now these reactions have only been characterized for conditions relevant to synthesis (high acidities and liquid phase systems) and remote from atmospheric ones. In this work, the uptake of gas-phase acetone and 2,4\\-pentanedione by sulfuric acid solutions has been measured at room temperature using a Rotated Wetted Wall Reactor coupled to a Mass Spectrometer. The aldol condensation rate constants for 2,4\\-pentanedione measured so far for sulfuric acid solutions between 96 and 70 % wt. display a variation with acidity in agreement with what predicted in the organic chemical literature. The values of these constants, however, are much lower than expected for this compound, and comparable to the ones of acetone. Experiments are underway to complete this study to lower acidities and understand the discrepancies with the predicted reactivity.

  1. Blot-MS of Carbonylated Proteins: A Tool to Identify Oxidized Proteins.

    PubMed

    Ferreira, Rita; Domingues, Pedro; Amado, Francisco; Vitorino, Rui

    2016-01-01

    The efficiency of proteostasis regulation declines during aging and the failure of protein homeostasis is common in age-related diseases. Protein oxidation is a major contributor to the loss of proteome homeostasis, also called "proteostasis," precluding protein misfolding and aggregation. So, the identification of the molecular pathways impaired by protein oxidation will increase the understanding of proteostasis and the pathophysiological conditions related to the loss of proteostasis. Sample derivatization with dinitrophenyl hydrazine and western blot immunoassay detection of carbonylated proteins (commonly known as Oxyblot™) coupled to mass spectrometry (blot-MS) is an attractive methodological approach to identify proteins that are more prone to carbonylation, a typical oxidative modification of amino acid residues. The integration of blot-MS data of carbonylated proteins with bioinformatics tools allows the identification of the biological processes more affected by protein oxidation and that, eventually, result in the loss of proteostasis.In this chapter, we describe a blot-MS methodology to identify the proteins more prone to oxidation in biological samples, as cell and tissue extracts, and biofluids. Analysis of mitochondria isolated from cardiac tissue is provided as an example. Bioinformatic strategy to deal with data retrieved from blot-MS experiments are proposed for the identification of relevant biological processes modulated by oxidative stress stimuli. PMID:27613049

  2. Seasonal and diurnal characteristics of atmospheric carbonyls in Nanning, China

    NASA Astrophysics Data System (ADS)

    Guo, Songjun; Chen, Mei; Tan, Jihua

    2016-03-01

    For the first time, atmospheric carbonyls were measured to identify seasonal and diurnal variations in Nanning from October 2011 to July 2012. Formaldehyde (6.79 ± 3.39 μg/m3), acetaldehyde (15.81 ± 10.48 μg/m3) and acetone (5.43 ± 6.91 μg/m3) were the three most abundant carbonyls, accounting for ~ 85% of the total carbonyls. The average total concentrations of carbonyls and three abundant carbonyls showed significant high levels in summer compared to those in winter. Diurnal variations suggested that photochemical conditions, combustion of charcoal and straw, and solvent usage are important for the distributions of atmospheric carbonyls. The highest average C1/C2 ratio was observed in summer (0.75) compared to those (0.31-0.70) in other seasons, implying the positive effect of photochemical activities on raising C1/C2 ratio, and the significant low C2/C3 ratio (12.01-18.23) in winter and autumn than those (95.83-24.49) in both spring and summer suggested the important anthropogenic emissions such as charcoal and biomass combustion. O3 formation potentials in summer and spring were significantly higher by ~ 2 times than those in autumn and winter. Formaldehyde and acetaldehyde are the top two carbonyls which contribute 82-97% to total O3 formation potentials.

  3. Formation of Small Gas Phase Carbonyls from Heterogeneous Oxidation of Polyunsaturated Fatty Acids (PUFA)

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Zhao, R.; Lee, A.; Gao, S.; Abbatt, J.

    2011-12-01

    Fatty acids (FAs) are emitted into the atmosphere from gas and diesel powered vehicles, cooking, plants, and marine biota. Field measurements have suggested that FAs, including polyunsaturated fatty acids (PUFA), could make up an important contribution to the organic fraction of atmospheric aerosols. Due to the existence of carbon-carbon double bonds in their molecules, PUFA are believed to be highly reactive towards atmospheric oxidants such as OH and NO3 radicals and ozone, which will contribute to aerosol hygroscopicity and cloud condensation nuclei activity. Previous work from our group has shown that small carbonyls formed from the heterogeneous reaction of linoleic acid (LA) thin films with gas-phase O3. It is known that the formation of small carbonyls in the atmosphere is not only relevant to the atmospheric budget of volatile organic compounds but also to secondary organic aerosol formation. In the present study, using an online proton transfer reaction mass spectrometry (PTR-MS) and off-line gas chromatography-mass spectrometry (GC-MS) we again investigated carbonyl formation from the same reaction system, i.e. the heterogeneous ozonolysis of LA film. In addition to the previously reported carbonyls, malondialdehyde (MDA), a source of reactive oxygen species that is mutagenic, has been identified as a product for the first time. Small dicarbonyls, e.g. glyoxal, are expected to be formed from the further oxidation of MDA. In this presentation, the gas-phase chemistry of MDA with OH radicals using a newly built Teflon chamber in our group will also be presented.

  4. Do lab-derived distribution coefficient values of pesticides match distribution coefficient values determined from column and field-scale experiments? A critical analysis of relevant literature.

    PubMed

    Vereecken, H; Vanderborght, J; Kasteel, R; Spiteller, M; Schäffer, A; Close, M

    2011-01-01

    In this study, we analyzed sorption parameters for pesticides that were derived from batch and column or batch and field experiments. The batch experiments analyzed in this study were run with the same pesticide and soil as in the column and field experiments. We analyzed the relationship between the pore water velocity of the column and field experiments, solute residence times, and sorption parameters, such as the organic carbon normalized distribution coefficient ( ) and the mass exchange coefficient in kinetic models, as well as the predictability of sorption parameters from basic soil properties. The batch/column analysis included 38 studies with a total of 139 observations. The batch/field analysis included five studies, resulting in a dataset of 24 observations. For the batch/column data, power law relationships between pore water velocity, residence time, and sorption constants were derived. The unexplained variability in these equations was reduced, taking into account the saturation status and the packing status (disturbed-undisturbed) of the soil sample. A new regression equation was derived that allows estimating the values derived from column experiments using organic matter and bulk density with an value of 0.56. Regression analysis of the batch/column data showed that the relationship between batch- and column-derived values depends on the saturation status and packing of the soil column. Analysis of the batch/field data showed that as the batch-derived value becomes larger, field-derived values tend to be lower than the corresponding batch-derived values, and vice versa. The present dataset also showed that the variability in the ratio of batch- to column-derived value increases with increasing pore water velocity, with a maximum value approaching 3.5. PMID:21546674

  5. The effect of iodine on the peroxidation of carbonyl compounds.

    PubMed

    Zmitek, Katja; Zupan, Marko; Stavber, Stojan; Iskra, Jernej

    2007-08-17

    Peroxidation of ketones and aldehydes with iodine as a catalyst was studied. Ketones reacted with 30% aq hydrogen peroxide in the presence of 10 mol % of iodine to yield gem-dihydroperoxides in acetonitrile and hydroperoxyketals in methanol. The yield of hydroperoxidation of various cyclic ketones was 60-98%, including androstane-3,17-dione, while acyclic ketones were converted with a similar efficiency. Aromatic aldehydes were also converted to gem-dihydroperoxides with hydrogen peroxide and iodine as catalyst in acetonitrile and to hydroperoxyacetal in methanol, while the reactivity of aliphatic ones remained the same as in noncatalyzed reactions. tert-Butylhydroperoxide reacted in a similar manner, giving the corresponding perether derivatives. A study was also made of the relative kinetics of dihydroperoxidation from which the Hammet equation gave a reaction constant (rho) of -2.76, indicating the strong positive charge development in the transition state and the important role of rehybridization in the conversion of hydroperoxyhemiketal to gem-dihydroperoxide. In acetonitrile, the iodine catalyst is apparently able to discriminate between the elimination of a hydroxy, methoxy, and hydroperoxy group and addition of water, methanol, and H2O2 to a carbonyl group. PMID:17661522

  6. Characterization of Aura TES carbonyl sulfide retrievals over ocean

    NASA Astrophysics Data System (ADS)

    Kuai, L.; Worden, J.; Kulawik, S. S.; Montzka, S. A.; Liu, J.

    2014-01-01

    We present a description of the NASA Aura Tropospheric Emission Spectrometer (TES) carbonyl sulfide (OCS) retrieval algorithm for oceanic observations, along with evaluation of the biases and uncertainties using aircraft profiles from the HIPPO (HIAPER Pole-to-Pole Observations) campaign and data from the NOAA Mauna Loa site. In general, the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 and 500 hPa, (3) but have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. We estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements. TES OCS data also captures the seasonal and latitudinal variations observed by these in situ data.

  7. ansa-Chromocene complexes. 1. Synthesis and characterization of Cr(II) carbonyl and tert-butyl isocyanide complexes

    SciTech Connect

    Matare, G.J.; Foo, D.M.; Kane, K.M.; Zehnder, R.; Wagener, M.; Shapiro, P.J.; Concolino, T.; Rheingold, A.L.

    2000-04-17

    ansa-Calcocene compounds are effective reagents for the synthesis of ansa-chromocene complexes from CrCl{sub 2} in the presence of a trapping ligand such as carbon monoxide or an isonitrile. A variety of ansa-chromocene carbonyl and tert-butyl isocyanide complexes have been prepared in this manner in high yields. The X-ray crystal structure of one of these complexes, [trans-1,2-(3,4-(CH{sub 3}O){sub 2}C{sub 6}H{sub 3}){sub 2}C{sub 2}H{sub 2}{l_brace}{eta}{sup 5}-C{sub 5}H{sub 4}{r_brace}{sub 2}]CrCO, is described. Electrochemical studies on these complexes show that the isonitrile derivatives are more easily oxidized than the carbonyl derivatives. Preliminary examination of the reactivity of these complexes indicates that the nature of the substitution along the ethanediyl ansa-bridge influences the relative stabilities of the carbonyl complexes to oxidation in air, the ease with which the carbonyl ligands undergo substitution with tert-butyl isocyanide, and the relative sensitivities of the tert-butyl isocyanide adducts to photodecomposition. The ansa-bridge substitution also appears to influence the ability of the complexes to undergo structural changes, such as ring slippage, as revealed in their cyclic voltammograms.

  8. Targeting Reactive Carbonyl Species with Natural Sequestering Agents.

    PubMed

    Hwang, Sung Won; Lee, Yoon-Mi; Aldini, Giancarlo; Yeum, Kyung-Jin

    2016-01-01

    Reactive carbonyl species generated by the oxidation of polyunsaturated fatty acids and sugars are highly reactive due to their electrophilic nature, and are able to easily react with the nucleophilic sites of proteins as well as DNA causing cellular dysfunction. Levels of reactive carbonyl species and their reaction products have been reported to be elevated in various chronic diseases, including metabolic disorders and neurodegenerative diseases. In an effort to identify sequestering agents for reactive carbonyl species, various analytical techniques such as spectrophotometry, high performance liquid chromatography, western blot, and mass spectrometry have been utilized. In particular, recent advances using a novel high resolution mass spectrometry approach allows screening of complex mixtures such as natural products for their sequestering ability of reactive carbonyl species. To overcome the limited bioavailability and bioefficacy of natural products, new techniques using nanoparticles and nanocarriers may offer a new attractive strategy for increased in vivo utilization and targeted delivery of bioactives. PMID:26927058

  9. Infrared photodissociation spectroscopy of vanadium oxide-carbonyl cations.

    PubMed

    Brathwaite, A D; Ricks, A M; Duncan, M A

    2013-12-19

    Mass selected vanadium oxide-carbonyl cations of the form VO(m)(CO)(n)(+) (m = 0-3 and n = 3-6) are studied via infrared laser photodissociation spectroscopy in the 600-2300 cm(-1) region. Insight into the structure and bonding of these complexes is obtained from the number of infrared active bands, their relative intensities and their frequency positions. Density functional theory calculations are carried out in support of the experimental data. The effect of oxidation on the carbonyl stretching frequencies of VO(CO)(n)(+), VO2(CO)(n)(+), and VO3(CO)(n)(+) complexes is investigated. All of these oxide-carbonyl species have C-O stretch vibrations blue-shifted from those of the pure vanadium ion carbonyls. The V-O stretches of these complexes are also investigated, revealing the effects of CO coordination on these vibrations. The oxide-carbonyls all have a hexacoordinate core analogous to that of V(CO)6(+). The fully coordinated vanadium monoxide-carbonyl species is VO(CO)5(+), and those of the dioxide and trioxide are VO2(CO)4(+) and VO3(CO)3(+), respectively. PMID:23927497

  10. Carbonyl species characteristics during the evaporation of essential oils

    NASA Astrophysics Data System (ADS)

    Chiang, Hsiu-Mei; Chiu, Hua-Hsien; Lai, Yen-Ming; Chen, Ching-Yen; Chiang, Hung-Lung

    2010-06-01

    Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6-8.3 kcal mol -1, the reaction order was in the range of 0.6-0.7 and the frequency factor was 360-2838 min -1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034-0.170 ppm. The emission factors of carbonyl compounds were 2.10-3.70 mg g -1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.

  11. Genome Sequences of Industrially Relevant Saccharomyces cerevisiae Strain M3707, Isolated from a Sample of Distillers Yeast and Four Haploid Derivatives

    SciTech Connect

    Brown, Steven D.; Klingeman, Dawn M.; Johnson, Courtney M.; Clum, Alicia; Aerts, Andrea; Salamov, Asaf; Sharma, Aditi; Zane, Matthew; Barry, Kerrie; Grigoriev, Igor V.; Davison, Brian H.; Lynd, Lee R.; Gilna, Paul; Hau, Heidi; Hogsett, David A.; Froehlich, Allan C.

    2013-04-19

    Saccharomyces cerevisiae strain M3707 was isolated from a sample of commercial distillers yeast, and its genome sequence together with the genome sequences for the four derived haploid strains M3836, M3837, M3838, and M3839 has been determined. Yeasts have potential for consolidated bioprocessing (CBP) for biofuel production, and access to these genome sequences will facilitate their development.

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

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Okuzawa, K.; Aggarwal, S. G.; Irie, H.; Kanaya, Y.; Wang, Z.

    2013-05-01

    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(trimethylsilyl)trifluoroacetamide (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.

  13. Environmental variables controlling the uptake of carbonyl sulfide by lichens

    NASA Astrophysics Data System (ADS)

    Kuhn, U.; Kesselmeier, J.

    2000-11-01

    The uptake of atmospheric carbonyl sulfide (COS) by the lichen species Ramalina menziesii, representative for the open oak woodland in central California, was studied under laboratory conditions. By use of a dynamic cuvette system, the controlling parameters for the COS uptake were investigated under climate chamber conditions. The thallus water content, essential for the overall physiology of lichens, was found to be of basic importance for the trace gas exchange. A water content of 30% was the approximate minimum for COS uptake, with increasing activity up to a water content of 200%. Additionally, actual atmospheric mixing ratios have a significant influence on the exchange. The COS uptake was found to be a linear function of the ambient COS mixing ratio resulting in a compensation point as low as 37 ppt. A temperature optimum of 25°C was indicative of a physiological basis of the COS uptake. The inhibition of the COS consumption in the presence of a specific inhibitor for the enzyme carbonic anhydrase proved this enzyme to be of key relevance for the uptake. All these variables controlling the COS deposition were integrated into an uptake algorithm to model the exchange behavior of this lichen. The applicability of the model to field data is demonstrated. Uptake rates on a dry weight basis normalized to optimized conditions (25°C; 450 ppt COS) reached 0.17±0.09 pmol g-1 s-1 (i.e. 4.2±2.2 pmol m-2 s-1 thallus surface area, respectively). The contribution of lichens to the global COS sink strength is assigned to be about 0.3 Tg a-1, representing not a major but a significant sink.

  14. Toxicologically Relevant Aldehydes Produced during the Frying Process Are Trapped by Food Phenolics.

    PubMed

    Zamora, Rosario; Aguilar, Isabel; Granvogl, Michael; Hidalgo, Francisco J

    2016-07-13

    The lipid-derived carbonyl trapping ability of phenolic compounds under common food processing conditions was studied by determining the presence of carbonyl-phenol adducts in both onions fried in the laboratory and commercially crispy fried onions. Four carbonyl-phenol adducts produced between quercetin and acrolein, crotonaldehyde, or (E)-2-pentenal were prepared and characterized by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy and high performance liquid chromatography coupled to high resolution mass spectrometry (HPLC-HRMS). The synthesized compounds were 2-(3,4-dihydroxyphenyl)-3,5,8-trihydroxy-9,10-dihydro-4H,8H-pyrano[2,3-f]chromen-4-one (4), 2-(3,4-dihydroxyphenyl)-3,5,8-trihydroxy-10-methyl-9,10-dihydro-4H,8H-pyrano[2,3-f]chromen-4-one (5), 2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-8-methyl-4H,8H-pyrano[2,3-f]chromen-4-one (9), and 2-(3,4-dihydroxyphenyl)-8-ethyl-3,5-dihydroxy-4H,8H-pyrano[2,3-f]chromen-4-one (10). When onions were fried in fresh rapeseed oil spiked with acrolein, crotonaldehyde, and (E)-2-pentenal (2.7 μmol/g of oil), adduct 10 was the major compound produced, and trace amounts of adducts 4 and 5, but not of adduct 9, were also detected. In contrast, compound 4 was the major adduct present in commercially crispy fried onions. Compound 10 was also present to a lower extent, and trace amounts of compound 5, but not of compound 9, were also detected. These data suggested that lipid-derived carbonyl-phenol adducts are formed in food products under standard cooking conditions. They also pointed to a possible protective role of food polyphenols, which might contribute to the removal of toxicologically relevant aldehydes produced during deep-frying, assuming that the formed products are stable during food consumption in the human organism. PMID:27322490

  15. Photon-Induced Thermal Desorption of CO from Small Metal-Carbonyl Clusters

    NASA Astrophysics Data System (ADS)

    Lüttgens, G.; Pontius, N.; Bechthold, P. S.; Neeb, M.; Eberhardt, W.

    2002-02-01

    Thermal CO desorption from photoexcited free metal-carbonyl clusters has been resolved in real time using two-color pump-probe photoelectron spectroscopy. Sequential energy dissipation steps between the initial photoexcitation and the final desorption event, e.g., electron relaxation and thermalization, have been resolved for Au2(CO)- and Pt2(CO)-5. The desorption rates for the two clusters differ considerably due to the different numbers of vibrational degrees of freedom. The unimolecular CO-desorption thresholds of Au2(CO)- and Pt2(CO)-5 have been approximated by means of a statistical Rice-Ramsperger-Kassel calculation using the experimentally derived desorption rate constants.

  16. Transition Metal Carbonyls Combined with Hydrogen Donors as Initiators of the Radical Reduction of Trichloromethyl Compounds

    NASA Astrophysics Data System (ADS)

    Freidlina, R. Kh; Gasanov, Rashid G.; Kuz'mina, Nadezhda A.; Chukovskaya, E. Ts

    1985-07-01

    The review is devoted to new redox catalysts of the homolytic reduction of trichloromethyl compounds to dichloromethyl compounds — mononuclear and dinuclear metal carbonyls [Fe(CO)5, Ni(CO)4, M(CO)6 (M = Mo, Cr, W), Mn2(CO)10] in combination with hydrogen donors (secondary alcohols, silicon hydrides, mercaptans, tertiary amines, amides, and tetrahydrofuran). The results obtained hitherto concerning the development of a new radical-chain method for the reduction of a wide variety of trichloromethyl compounds to the dichloromethyl derivatives are surveyed. The bibliography includes 78 references.

  17. Carbonyl emissions from vehicular exhausts sources in Hong Kong.

    PubMed

    Ho, Steven Sai Hang; Ho, Kin Fai; Lee, Shun Cheng; Cheng, Yan; Yu, Jian Zhen; Lam, Ka Man; Feng, Natale Sin Yau; Huang, Yu

    2012-02-01

    Vehicular emission (VE) is one of the important anthropogenic sources for airborne carbonyls in urban area. Six types of VE-dominated samples were collected at representative locations in Hong Kong where polluted by a particular fueled type of vehicles, including (i) a gas refilling taxis station (liquefied petroleum gas [LPG] emission); (ii) a light-duty passenger car park (gasoline emission); (iii) a minibus station (diesel emission); (iv) a single-deck-bus depot (diesel emission); (v) a double-deck-bus depot (diesel emission); and (vi) a whole-food market entrance for light- and heavy-duty vehicles (diesel emission). A total of 15 carbonyls in the samples were quantified. Formaldehyde was the most abundant carbonyl among the VE-dominated samples, and its contribution to the total quantified amount on a molar basis ranged from 54.8% to 60.8%. Acetaldehyde and acetone were the next two abundant carbonyls. The carbonyls were quantified at three roadside locations in Hong Kong. The highest concentrations of formaldehyde and acetaldehyde, 22.7 +/- 8.4 and 6.0 +/- 2.8 microg/m3, respectively, were determined in the samples collected at a main transportation gate for goods between Hong Kong and Mainland China. The total quantified carbonyl concentration, 37.9 +/- 9.3 microg/m3, was the highest at an entrance of a cross-harbor tunnel in downtown area. The theoretical carbonyls compositions of the three roadside locations were estimated according to the VE-dominated sample profiles and the statistics on vehicle numbers and types during the sampling period. The measured compositions of formaldehyde were much higher than the theoretical compositions in summer, demonstrating that photochemical reactions significantly contributed to the formaldehyde production in the roadsides. PMID:22442938

  18. Carbonyl derivatives of chloride-dimethyl sulfoxide-ruthenium(III) complexes: Synthesis, crystal structure, and reactivity of [(DMSO){sub 2}H][trans-RuCl{sub 4}(DMSO)(CO)] and mer,cis-RuCl{sub 3}(DMSO){sub 2}(CO)

    SciTech Connect

    Alessio, E.; Bolle, M.; Milani, B.

    1995-09-13

    [(DMSO){sub 2}{sub 2}H][trans-RuCl{sub 4}(DMSO){sub 2}] (1) and mer,trans-RuCl{sub 3}(DMSO){sub 2}(DMSO) (2) (DMSO = S-bonded dimethyl sulfoxide; DMSO = O-bonded dimethyl sulfoxide; DMSO = O bonded dimethyl sulfoxide) react with carbon monoxide at room temperature and atmospheric pressure to give [(DMSO){sub 2}H][trans-RuCl{sub 4}(DMSO)(CO)] (3) and mer,cis-RuCl{sub 3}(DMSO){sub 2-} (CO) (4), respectively. Coordination of carbon monoxide induces the S to O linkage iosmerization of the DMSO ligand trans to it. Compounds 3 and 4 represent the first example of Ru-(III) chloride-DMSO-carbonyl complexes. In both 3 and 4 the DMSO ligand trans to CO is weakly bonded and easily replaced by a nitrogen donor ligand.

  19. Gas phase carbonyl compounds in ship emissions: Differences between diesel fuel and heavy fuel oil operation

    NASA Astrophysics Data System (ADS)

    Reda, Ahmed A.; Schnelle-Kreis, J.; Orasche, J.; Abbaszade, G.; Lintelmann, J.; Arteaga-Salas, J. M.; Stengel, B.; Rabe, R.; Harndorf, H.; Sippula, O.; Streibel, T.; Zimmermann, R.

    2014-09-01

    Gas phase emission samples of carbonyl compounds (CCs) were collected from a research ship diesel engine at Rostock University, Germany. The ship engine was operated using two different types of fuels, heavy fuel oil (HFO) and diesel fuel (DF). Sampling of CCs was performed from diluted exhaust using cartridges and impingers. Both sampling methods involved the derivatization of CCs with 2,4-Dinitrophenylhydrazine (DNPH). The CCs-hydrazone derivatives were analyzed by two analytical techniques: High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Gas Chromatography-Selective Ion Monitoring-Mass Spectrometry (GC-SIM-MS). Analysis of DNPH cartridges by GC-SIM-MS method has resulted in the identification of 19 CCs in both fuel operations. These CCs include ten aliphatic aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, octanal, nonanal), three unsaturated aldehydes (acrolein, methacrolein, crotonaldehyde), three aromatic aldehyde (benzaldehyde, p-tolualdehyde, m,o-molualdehyde), two ketones (acetone, butanone) and one heterocyclic aldehyde (furfural). In general, all CCs under investigation were detected with higher emission factors in HFO than DF. The total carbonyl emission factor was determined and found to be 6050 and 2300 μg MJ-1 for the operation with HFO and DF respectively. Formaldehyde and acetaldehyde were found to be the dominant carbonyls in the gas phase of ship engine emission. Formaldehyde emissions factor varied from 3500 μg MJ-1 in HFO operation to 1540 μg MJ-1 in DF operation, which is 4-30 times higher than those of other carbonyls. Emission profile contribution of CCs showed also a different pattern between HFO and DF operation. The contribution of formaldehyde was found to be 58% of the emission profile of HFO and about 67% of the emission profile of DF. Acetaldehyde showed opposite behavior with higher contribution of 16% in HFO compared to 11% for DF. Heavier carbonyls

  20. Palladium/Silver Synergistic Catalysis in Direct Aerobic Carbonylation of C(sp(2))-H Bonds Using DMF as a Carbon Source: Synthesis of Pyrido-Fused Quinazolinones and Phenanthridinones.

    PubMed

    Nageswar Rao, D; Rasheed, Sk; Das, Parthasarathi

    2016-07-01

    An unprecedented Pd/Ag synergistic catalysis in the direct carbonylation of C(sp(2))-H bonds utilizing DMF as the carbon source under oxygen is described and demonstrated in the synthesis of pyrido-fused quinazolinone and phenanthridinone scaffolds. Control experiments indicated that the "C" of the carbonyl group is derived from the methyl group of DMF and "O" originates from oxygen as in the case of Ge's recent work. This transformation offers an alternative avenue for "CO-free" carbonylations. PMID:27276385

  1. Clinical features of schizophrenia with enhanced carbonyl stress.

    PubMed

    Miyashita, Mitsuhiro; Arai, Makoto; Kobori, Akiko; Ichikawa, Tomoe; Toriumi, Kazuya; Niizato, Kazuhiro; Oshima, Kenichi; Okazaki, Yuji; Yoshikawa, Takeo; Amano, Naoji; Miyata, Toshio; Itokawa, Masanari

    2014-09-01

    Accumulating evidence suggests that advanced glycation end products, generated as a consequence of facilitated carbonyl stress, are implicated in the development of a variety of diseases. These diseases include neurodegenerative illnesses, such as Alzheimer disease. Pyridoxamine is one of the 3 forms of vitamin B6, and it acts by combating carbonyl stress and inhibiting the formation of AGEs. Depletion of pyridoxamine due to enhanced carbonyl stress eventually leads to a decrease in the other forms of vitamin B6, namely pyridoxal and pyridoxine. We previously reported that higher levels of plasma pentosidine, a well-known biomarker for advanced glycation end products, and decreased serum pyridoxal levels were found in a subpopulation of schizophrenic patients. However, there is as yet no clinical characterization of this subset of schizophrenia. In this study, we found that these patients shared many clinical features with treatment-resistant schizophrenia. These include a higher proportion of inpatients, low educational status, longer durations of hospitalization, and higher doses of antipsychotic medication, compared with patients without carbonyl stress. Interestingly, psychopathological symptoms showed a tendency towards negative association with serum vitamin B6 levels. Our results support the idea that treatment regimes reducing carbonyl stress, such as supplementation of pyridoxamine, could provide novel therapeutic benefits for this subgroup of patients. PMID:24062594

  2. [Protein carbonylation and its role in physiological processes in plants].

    PubMed

    Debska, Karolina; Bogatek, Renata; Gniazdowska, Agnieszka

    2012-01-01

    Plant cells produce reactive oxygen species (ROS) continuously as a byproducts of oxygen metabolism and reaction to various environmental stresses. ROS are considered as chemicals inducing damage of cellular components (DNA, lipids and proteins), but also might act as signaling agents. Protein oxidation is one of covalent modification of protein induced by ROS or other products of oxidative stress. Carbonylation of particular amino acid residues (arginine, lysine, treonine or proline) is one of the most commonly occurring oxidative modification of proteins. This modification might lead to alteration in protein activity, its proteolytic breakdown or, in the opposite, aggregate formation. Carbonylated proteins have been identified in many plant species at different stage of growth and development. The analysis of subcellular localization of carbonylated proteins arised the hypothesis on their signaling function. We summarize the current knowledge on the detection of carbonylation protein in plants taking to the account the conditions which may influence their production or removal. We present also their putative role in plant physiology and discuss interaction between ROS and RNS in regulation of protein carbonylation. PMID:23214127

  3. Enantioselective synthesis and olfactory evaluation of bicyclic alpha- and gamma-ionone derivatives: the 3D arrangement of key molecular features relevant to the violet odor of ionones.

    PubMed

    Luparia, Marco; Legnani, Laura; Porta, Alessio; Zanoni, Giuseppe; Toma, Lucio; Vidari, Giovanni

    2009-09-18

    Violet smelling ionones 1-3, occurring in the headspace of different flowers, are well-known perfumery raw materials. With the goal to recognize the still ill-defined spatial arrangement of structural features relevant to the binding of ionones to olfactory G-protein coupled receptors, through B3LYP/6-31G(d) modeling studies we identified bicyclic compounds 7-9 as conformationally constrained 13-alkyl-substituted analogues of monocyclic alpha- and gamma-ionones. They were thus synthesized to evaluate the olfactory properties. The enantioselective syntheses of 7-9 entailed two common key steps: (i) a Diels-Alder reaction to construct the octalinic core and (ii) a Julia-Lythgoe olefination to install the alpha,beta-enone side chain. The odor thresholds of synthetic 7 and 9 were significantly lower than the corresponding parent ionones, and 9 showed the lowest threshold value among violet-smelling odorants examined so far. Modeling studies suggested a nearly identical spatial orientation of key hydrophobic and polar moieties of compounds 1, 3, and 4-9. Presumably, interaction of these moieties with ionone olfactory receptors (ORs) triggers a similar receptor code that is ultimately interpreted by the human brain as a pleasant woody-violet smell. These results open the way to studies aimed at identifying and modeling complementary binding sites on alpha-helical domains of ionone receptor proteins. PMID:19743882

  4. Migration statistics relevant for malaria transmission in Senegal derived from mobile phone data and used in an agent-based migration model.

    PubMed

    Tompkins, Adrian M; McCreesh, Nicky

    2016-01-01

    One year of mobile phone location data from Senegal is analysed to determine the characteristics of journeys that result in an overnight stay, and are thus relevant for malaria transmission. Defining the home location of each person as the place of most frequent calls, it is found that approximately 60% of people who spend nights away from home have regular destinations that are repeatedly visited, although only 10% have 3 or more regular destinations. The number of journeys involving overnight stays peaks at a distance of 50 km, although roughly half of such journeys exceed 100 km. Most visits only involve a stay of one or two nights away from home, with just 4% exceeding one week. A new agent-based migration model is introduced, based on a gravity model adapted to represent overnight journeys. Each agent makes journeys involving overnight stays to either regular or random locations, with journey and destination probabilities taken from the mobile phone dataset. Preliminary simulations show that the agent-based model can approximately reproduce the patterns of migration involving overnight stays. PMID:27063741

  5. Catalytic production of metal carbonyls from metal oxides

    DOEpatents

    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.

  6. Catalytic production of metal carbonyls from metal oxides

    DOEpatents

    Sapienza, R.S.; Slegeir, W.A.; Foran, M.T.

    1984-01-06

    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 to 260/sup 0/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. 3 tables.

  7. Infrared Photodissociation Spectroscopy of Metal Oxide Carbonyl Cations.

    NASA Astrophysics Data System (ADS)

    Brathwaite, Antonio D.; Duncan, Michael A.

    2013-06-01

    Mass selected metal oxide-carbonyl cations of the form MO_{m}(CO)_{n}^{+} are studied via infrared laser photodissociation spectroscopy, in the 600-2300cm^{1} region. Insight into the structure and bonding of these complexes is obtained from the number of infrared active bands, their relative intensities and their frequency positions. Density functional theory calculations are carried out in support of the experimental data. Insight into the bonding of CO ligands to metal oxides is obtained and the effect of oxidation on the carbonyl stretching frequency is revealed.

  8. Measurements of C1-C4 alkyl nitrates and their relationships with carbonyl compounds and O3 in Chinese cities

    NASA Astrophysics Data System (ADS)

    Wang, Ming; Shao, Min; Chen, Wentai; Lu, Sihua; Wang, Chen; Huang, Daikuan; Yuan, Bin; Zeng, Limin; Zhao, Yue

    2013-12-01

    Ambient alkyl nitrates (RONO2) are important byproducts of O3 formation. Although concern about O3 pollution has increased recently, few studies have investigated RONO2 chemistry and distributions in China. In this study, ambient levels of C1-C4 RONO2 were measured in Chinese cities, and their relationships with parent hydrocarbons (RH), carbonyls, and total oxidant (Ox = O3 + NO2) were investigated. Our measurements showed that 2-butyl nitrate (2-BuONO2) was the most abundant RONO2 species, with mixing ratios of 48-88 pptv, followed by 2-propyl nitrate (2-PrONO2), ethyl nitrate (EtONO2), methyl nitrate (MeONO2), and 1-propyl nitrate (1-PrONO2). The measured RONO2 species exhibited maximum levels in the early afternoon (13:00-14:00) of summer, suggesting the importance of RONO2 photochemical production. Relative to 2-BuONO2/n-butane, the measured 1-PrONO2/propane agreed well with the modeled ratio based on laboratory kinetic data, suggesting that propane was the dominant precursor of ambient 1-PrONO2. However, the measured ratios for MeONO2/methane, EtONO2/ethane, and summertime 2-PrONO2/propane showed significant positive deviations from the predicted values, indicating the existence of additional sources other than OH oxidation of the parent hydrocarbons. Initial mixing ratios of C1-C3 carbonyls during 08:00-12:00 in summer at the PKU site exhibited significant correlations with RONO2 levels, suggesting the importance of secondary sources for ambient carbonyls. The measured ratios of formaldehyde/MeONO2 were close to the theoretical ratio, whereas the derived ratios for acetaldehyde/EtONO2, propanal/1-PrONO2, and acetone/2-PrONO2 were higher than the kinetic ratios, indicating that these carbonyls might be produced from sources other than the reaction of alkoxy radicals with O2. Carbonyls are important precursors of Ox, but their photochemical reactions do not result in RONO2 production. Therefore, Ox/RONO2 could indicate the relative importance of carbonyls to

  9. Circulating Endothelial-Derived Apoptotic Microparticles in the Patients with Ischemic Symptomatic Chronic Heart Failure: Relevance of Pro-Inflammatory Activation and Outcomes

    PubMed Central

    Berezin, Alexander E.; Kremzer, Alexander A.; Samura, Tatayna A.; Martovitskaya, Yulia V.

    2014-01-01

    Background: Endothelial-derived apoptotic microparticles (EMPs) play a pivotal role in endothelial dysfunction in hronic Heart Failure (CHF). Objectives: The present study aimed to evaluate the association between EMPs and pro-inflammatory biomarkers, clinical status, and outcomes in the patients with ischemic CHF. Patients and Methods: This study was conducted on 154 patients with ischemic symptomatic moderate-to-severe CHF on discharge from hospital. The observation period was up to 3 years. Circulating NT-pro-BNP, TNF-alpha, sFas, and sFas ligand were determined at baseline. Flow cytometry analysis was used for quantifying the number of EMPs. All-cause mortality, CHF-related death, and CHD-re-hospitalization rate were examined. The data were analyzed using descriptive statistics, Receive Operation Characteristic Curve (ROC), and logistic regression analysis. Besides, P < 0.05 was considered as statistically significant. Results: During a median follow-up of 2.18 years, 21 participants died and 106 subjects were hospitalized repetitively. The results showed a significant difference between the patients with a large number of EMPs (> 0.514 n/mL) and those with a low level of the biomarker (< 0.514 n/mL) regarding their survival. The number of circulating EPMs independently predicted all-cause mortality (OR = 1.58; 95% CI = 1.20 – 1.88; P = 0.001), CHF-related death (OR = 1.22; 95% CI: 1.12 – 1.36; P < 0.001), and CHF-related re-hospitalization (OR = 1.20; 95% CI: 1.11 – 1.32; P < 0.001). Conclusions: Among the patients with symptoms of CHF, increased number of circulating EMPs was associated with increased 3-year CHF-related death, all-cause mortality, and risk of recurrent hospitalization due to CHF. PMID:25177675

  10. Analysis of protein oxidation in serum of fetal and newborn piglets and the influence of iron dextran on induction of protein carbonyls.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods were employed to evaluate serum biomarkers associated with protein oxidative stress and damage, to determine potential sources of metabolic stress in baby pigs. Protein carbonyls in serum were converted to dinitrophenyl (DNP) derivatives with DNP-hydrazine, precipitated with TCA, extracted i...

  11. Metal telluride clusters composed of niobocene carbonyl, telluride, and cobalt carbonyl units: syntheses, structures, and reactivity

    PubMed

    Brunner; Lucas; Monzon; Mugnier; Nuber; Stubenhofer; Stuckl; Wachter; Wanninger; Zabel

    2000-02-01

    Abstract: The reaction of [Cp#2NbTe2H] (1#; Cp# = Cp* (C5Me5) or Cp(x) (C5Me4Et)) with two equivalents of [Co2(CO)8] gives a series of cobalt carbonyl telluride clusters that contain different types of niobocene carbonyl fragments. At 0 degrees C, [Cp#2NbTe2CO3(CO)7] (2#) and [Co4Te2(CO)10] (3) are formed which disappear at higher temperatures: in boiling toluene a mixture of [cat2][Co9Te6(CO)8] (5#) (cat= [Cp#2Nb(CO)2]+) and [cat2][Co11Te7(CO)10] (6#) is formed along with [cat][Co(CO)4] (4#). Complexes 6# transform into [cat][Co11Te7(CO)10] (7#) upon interaction with HPF6 or wet SiO2. The molecular structures of 2(Cp(x)), 4(Cp(x)), 5(Cp*), 6(Cp*) and 7(Cp*) have been determined by X-ray crystallography. The structure of the neutral 2(Cp(x)) consists of a [Co3(CO)6Te2] bipyramid which is connected to a [(C5Me4Et)2Nb(CO)] fragment through a mu4-Te bridge. The ionic structures of 4(Cp(x)), 5(Cp*), 6(Cp*) and 7(Cp*) each contain one (4, 7) or two (5, 6) [Cp#2Nb(CO)2]+ cations. Apart from 4, the anionic counterparts each contain an interstitial Co atom and are hexacapped cubic cluster anions [Co9Te6(CO)8]2- (5) or heptacapped pentagonal prismatic cluster anions [Co11Te7(CO)10]n- (n=2: [6]2- , n=1: [7]-), respectively. Electrochemical studies established a reversible electron transfer between the anionic clusters [Co11,Te7(CO)10]- and [Co11Te7(CO)10]2in 6# and 7# and provided evidence for the existence of species containing [Co11Te7(CO),0] and [Co11Te7(CO)0]3-. The electronic structures of the new clusters and their relative stabilities are examined by means of DFT calculations. PMID:10747416

  12. Gel-free proteomic methodologies to study reversible cysteine oxidation and irreversible protein carbonyl formation.

    PubMed

    Boronat, S; García-Santamarina, S; Hidalgo, E

    2015-05-01

    Oxidative modifications in proteins have been traditionally considered as hallmarks of damage by oxidative stress and aging. However, oxidants can generate a huge variety of reversible and irreversible modifications in amino acid side chains as well as in the protein backbones, and these post-translational modifications can contribute to the activation of signal transduction pathways, and also mediate the toxicity of oxidants. Among the reversible modifications, the most relevant ones are those arising from cysteine oxidation. Thus, formation of sulfenic acid or disulfide bonds is known to occur in many enzymes as part of their catalytic cycles, and it also participates in the activation of signaling cascades. Furthermore, these reversible modifications have been usually attributed with a protective role, since they may prevent the formation of irreversible damage by scavenging reactive oxygen species. Among irreversible modifications, protein carbonyl formation has been linked to damage and death, since it cannot be repaired and can lead to protein loss-of-function and to the formation of protein aggregates. This review is aimed at researchers interested on the biological consequences of oxidative stress, both at the level of signaling and toxicity. Here we are providing a concise overview on current mass-spectrometry-based methodologies to detect reversible cysteine oxidation and irreversible protein carbonyl formation in proteomes. We do not pretend to impose any of the different methodologies, but rather to provide an objective catwalk on published gel-free approaches to detect those two types of modifications, from a biologist's point of view. PMID:25782062

  13. Cytokinin inhibits the proteasome-mediated degradation of carbonylated proteins in Arabidopsis leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under normal conditions, plants contain numerous carbonylated proteins, which are thought to be indicative of oxidative stress damage. Conditions that promote formation of reactive oxygen species (ROS) enhance protein carbonylation, and protein degradation is required to reverse the damage. However,...

  14. Age-related variations of protein carbonyls in human saliva and plasma: is saliva protein carbonyls an alternative biomarker of aging?

    PubMed

    Wang, Zhihui; Wang, Yanyi; Liu, Hongchen; Che, Yuwei; Xu, Yingying; E, Lingling

    2015-06-01

    Free radical hypothesis which is one of the most acknowledged aging theories was developed into oxidative stress hypothesis. Protein carbonylation is by far one of the most widely used markers of protein oxidation. We studied the role of age and gender in protein carbonyl content of saliva and plasma among 273 Chinese healthy subjects (137 females and 136 males aged between 20 and 79) and discussed the correlation between protein carbonyl content of saliva and plasma. Protein carbonyl content of saliva and plasma were, respectively, 2.391 ± 0.639 and 0.838 ± 0.274 nmol/mg. Variations of saliva and plasma different age groups all reached significant differences in both male and female (all p < 0.05) while both saliva and plasma protein carbonyls were found to be significantly correlated with age (r = 0.6582 and r = 0.5176, all p < 0.001). Gender was discovered to be unrelated to saliva and plasma protein carbonyl levels (all p > 0.05). Saliva and plasma protein carbonyls were positively related (r = 0.4405, p < 0.001). Surprisingly, saliva and plasma protein carbonyls/ferric reducing ability of plasma (FRAP) ratios were proved to be significantly correlated with age (r = 0.7796 and r = 0.6938, all p < 0.001) while saliva protein carbonyls/FRAP ratio and plasma protein carbonyls/FRAP ratio were also correlated (r = 0.5573, p < 0.001). We concluded that saliva protein carbonyls seem to be an alternative biomarker of aging while the mechanisms of protein carbonylation and oxidative stress and the relationship between saliva protein carbonyls and diseases need to be further investigated. PMID:25943699

  15. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, Jerome W.; Klingler, Robert J.

    1993-01-01

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  16. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, J.W.; Klingler, R.J.

    1993-03-30

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  17. Metal-Diazo Radicals of α-Carbonyl Diazomethanes

    NASA Astrophysics Data System (ADS)

    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.

  18. Comparing Carbonyl Chemistry in Comprehensive Introductory Organic Chemistry Textbooks

    ERIC Educational Resources Information Center

    Nelson, Donna J.; Kumar, Ravi; Ramasamy, Saravanan

    2015-01-01

    Learning the chemistry of compounds containing carbonyl groups is difficult for undergraduate students partly because of a convolution of multiple possible reaction sites, competitive reactions taking place at those sites, different criteria needed to discern between the mechanisms of these reactions, and no straightforward selection method…

  19. Iron-Sulfur-Carbonyl and -Nitrosyl Complexes: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1985-01-01

    Background information, materials needed, procedures used, and typical results obtained, are provided for an experiment on iron-sulfur-carbonyl and -nitrosyl complexes. The experiment involved (1) use of inert atmospheric techniques and thin-layer and flexible-column chromatography and (2) interpretation of infrared, hydrogen and carbon-13 nuclear…

  20. CARBONYL SULFIDE INHALATION PRODUCES BRAIN LESIONS IN F344 RATS.

    EPA Science Inventory

    Carbonyl sulfide (COS) is an intermediate in the production of pesticides and herbicides, and is a metabolite of the neurotoxicant carbon disulfide. The potential neurotoxicity of inhaled COS was investigated in F344 rats. Male rats were exposed to 0, 75, 150, 300, or 600 ppm COS...

  1. CARBONYLATION OF MYOSIN HEAVY CHAINS IN RAT HEARTS DURING DIABETES

    PubMed Central

    Shao, Chun-Hong; Rozanski, George J.; Nagai, Ryoji; Stockdale, Frank E.; Patel, Kaushik P.; Wang, Mu; Singh, Jaipaul; Mayhan, William G.; Bidasee, Keshore R.

    2010-01-01

    Cardiac inotropy progressively declines during diabetes mellitus. To date, the molecular mechanisms underlying this defect remain incompletely characterized. This study tests the hypothesis that ventricular myosin heavy chains (MHC) undergo carbonylation by reactive carbonyl species (RCS) during diabetes and these modifications contribute to the inotropic decline. Male Sprague-Dawley rats were injected with streptozotocin (STZ). Fourteen days later animals were divided into two groups: one group was treated with the RCS blocker aminoguanidine for six weeks, while the other group received no treatment. After eight weeks of diabetes, cardiac ejection fraction, fractional shortening, left ventricular pressure development (+dP/dt) and myocyte shortening were decreased by 9%, 16%, 34% and 18%, respectively. Ca2+- and Mg2+-actomyosin ATPase activities and peak actomyosin syneresis were also reduced by 35%, 28%, and 72%. MHC-α to MHC-β ratio was 12:88. Mass spectrometry and Western blots revealed the presence of carbonyl adducts on MHC-α and MHC-β. Aminoguandine treatment did not alter MHC composition, but it blunted formation of carbonyl adducts and decreases in actomyosin Ca2+-sensitive ATPase activity, syneresis, myocyte shortening, cardiac ejection fraction, fractional shortening and +dP/dt induced by diabetes. From these new data it can be concluded that in addition to isozyme switching, modification of MHC by RCS also contributes to the inotropic decline seen during diabetes. PMID:20359464

  2. Nature of Amide Carbonyl−Carbonyl Interactions in Proteins

    PubMed Central

    2010-01-01

    Noncovalent interactions define and modulate biomolecular structure, function, and dynamics. In many protein secondary structures, an intimate interaction exists between adjacent carbonyl groups of the main-chain amide bonds. As this short contact contributes to the energetics of protein conformational stability as well as protein−ligand interactions, understanding its nature is crucial. The intimacy of the carbonyl groups could arise from a charge−charge or dipole−dipole interaction, or n→π * electronic delocalization. This last putative origin, which is reminiscent of the Bürgi−Dunitz trajectory, involves delocalization of the lone pairs (n) of the oxygen (Oi−1) of a peptide bond over the antibonding orbital (π*) of the carbonyl group (Ci=Oi) of the subsequent peptide bond. By installing isosteric chemical substituents in a peptidic model system and using NMR spectroscopy, X-ray diffraction analysis, and ab initio calculations to analyze the consequences, the intimate interaction between adjacent carbonyl groups is shown to arise primarily from n→π* electronic delocalization. This finding has implications for organic, biological, and medicinal chemistry. PMID:19469574

  3. Methyl substituted polyimides containing carbonyl and ether connecting groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Havens, Stephen J. (Inventor)

    1992-01-01

    Polyimides were prepared from the reaction of aromatic dianhydrides with novel aromatic diamines having carbonyl and ether groups connecting aromatic rings containing pendant methyl groups. The methyl substituent polyimides exhibit good solubility and form tough, strong films. Upon exposure to ultraviolet irradiation and/or heat, the methyl substituted polyimides crosslink to become insoluble.

  4. Metal-Diazo Radicals of α-Carbonyl Diazomethanes

    PubMed Central

    Li, Feifei; Xiao, Longqiang; Liu, Lijian

    2016-01-01

    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. PMID:26960916

  5. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    SciTech Connect

    Rathke, J.W.; Klingler, R.J.

    1992-12-31

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  6. Quantitative structure-retention relationships applied to liquid chromatography gradient elution method for the determination of carbonyl-2,4-dinitrophenylhydrazone compounds.

    PubMed

    Cirera-Domènech, Elisenda; Estrada-Tejedor, Roger; Broto-Puig, Francesc; Teixidó, Jordi; Gassiot-Matas, Miquel; Comellas, Lluís; Lliberia, Josep Lluís; Méndez, Alberto; Paz-Estivill, Susanna; Delgado-Ortiz, Maria Rosa

    2013-02-01

    A usual method for the determination of aldehydes and ketones in different matrices consists of a derivatization with 2,4-dinitrophenylhydrazine (DNPH) followed by HPLC-UV analysis. In the present work, a HPLC-UV gradient elution method has been applied to the analysis of 13 aldehydes and ketones-DNPH in automotive emission samples. In addition to these 13 compounds-DNPH, several carbonyl-DNPH compounds (linear, ramified and cyclic, saturated and unsaturated compounds) have been analyzed by HPLC-UV. Quantitative structure-retention relationships (QSRR) methods have been applied to predict the logarithm of capacity factor (logk') of carbonyl-DNPH compounds. According to its physicochemical meaning, combinations of 2 and 3 molecular descriptors have been proposed in order to achieve higher correlation with logk'. Using linear and non-linear QSRR methodologies, the resulting prediction models allowed the screening of the most probable carbonyl-DNPH derivative candidates that correspond to unknown compounds detected in automotive emission samples. This information has been useful for their identification by UPLC(®)-MS/MS. In addition, the chromatographic retention of different carbonyl-DNPH compound families was studied using two HPLC isocratic methods working with two orthogonal stationary phases (octadecylpolyethoxysilane and cyanopropyl). Differences between the retention indexes obtained for each column were used for classifying carbonyl-DNPH into compounds families. PMID:23298845

  7. A new atmospherically relevant oxidant of sulphur dioxide.

    PubMed

    Mauldin, R L; Berndt, T; Sipilä, M; Paasonen, P; Petäjä, T; Kim, S; Kurtén, T; Stratmann, F; Kerminen, V-M; Kulmala, M

    2012-08-01

    Atmospheric oxidation is a key phenomenon that connects atmospheric chemistry with globally challenging environmental issues, such as climate change, stratospheric ozone loss, acidification of soils and water, and health effects of air quality. Ozone, the hydroxyl radical and the nitrate radical are generally considered to be the dominant oxidants that initiate the removal of trace gases, including pollutants, from the atmosphere. Here we present atmospheric observations from a boreal forest region in Finland, supported by laboratory experiments and theoretical considerations, that allow us to identify another compound, probably a stabilized Criegee intermediate (a carbonyl oxide with two free-radical sites) or its derivative, which has a significant capacity to oxidize sulphur dioxide and potentially other trace gases. This compound probably enhances the reactivity of the atmosphere, particularly with regard to the production of sulphuric acid, and consequently atmospheric aerosol formation. Our findings suggest that this new atmospherically relevant oxidation route is important relative to oxidation by the hydroxyl radical, at least at moderate concentrations of that radical. We also find that the oxidation chemistry of this compound seems to be tightly linked to the presence of alkenes of biogenic origin. PMID:22874964

  8. 40 CFR 721.10409 - Poly(oxyalkylenediyl), .alpha. - [ [ [methyl - 3 - [ [ [ (polyfluoroalkyl)oxy]carbonyl ] amino...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Poly(oxyalkylenediyl), .alpha... Poly(oxyalkylenediyl), .alpha. - carbonyl ] amino] phenyl]amino]carbonyl] - .omega. - methoxy... identified generically as poly(oxyalkylenediyl), .alpha.- carbonyl]amino]phenyl]amino]...

  9. Experimental observation of supramolecular carbonyl-π/π-π/π-carbonyl assemblies of Cu II complex of iminodiacetate and dipyridylamine

    NASA Astrophysics Data System (ADS)

    Kumar Seth, Saikat; Dey, Biswajit; Kar, Tanusree; Mukhopadhyay, Subrata

    2010-06-01

    A mononuclear Cu II complex [Cu(IDA)(2,2'-dypam)(H 2O)]·H 2O ( 1) where H 2IDA and 2,2'-dypam are iminodiacetic acid and 2,2´-dipyridylamine, respectively, has been synthesized and characterized by X-ray single crystal structure analysis. The Cu(II) atom exhibits an unsymmetrical elongated octahedral coordination type 4 + 1 + 1. X-ray crystallography reveals that complex ( 1) has an unprecedented fac-O 2 + N(apical) IDA conformation, in the trans-site of Cu-N (IDA-like) bond, in contrast with structural co-relations for complexes with Cu/(IDA or IDA-like)/N-heterocyclic donor ratio 1/1/2 and closely related compounds fac-NO + O(apical) IDA-like conformation and one N-heterocyclic donor in the trans-site to the Cu-N (IDA-like) bond. These findings are attributed to the influence of π-π stacking, C-H⋯π interactions in the molecular recognition process. Moreover, the aromatic moieties of 2,2'-dypam are engaged in carbonyl⋯π interaction with the non-coordinated carbonyl groups of IDA ligand and giving rise to a remarkable supramolecular carbonyl-π/π-π/π-carbonyl interactions.

  10. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions

    PubMed Central

    Weber, Daniela; Davies, Michael J.; Grune, Tilman

    2015-01-01

    Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples. PMID:26141921

  11. Selective transformation of carbonyl ligands to organic molecules. Progress report, September 1, 1989--November 14, 1992

    SciTech Connect

    Cutler, A.R.

    1992-05-12

    Studies on the carbonylation of ({eta}{sup 5}-indenyl)(L)(CO)Ru-R complexes (L = CO, PPh{sub 3}; R = CH{sub 2}OMe, CH{sub 3}) have been completed. Particularly noteworthy is that the methoxymethyl complexes readily transform to their acyl derivatives under mild conditions that leave their iron congeners inert towards CO. Surprisingly, even ({eta}{sup 5}-indenyl)(PPh{sub 3}){sub 2}Ru-CH{sub 3} carbonylates and gives ({eta}{sup 5}-indenyl)(PPh{sub 3})(CO)Ru-C(O)CH{sub 3}. Mechanistic studies on the ``non catalyzed`` hydrosilation of the manganese acyls (CO){sub 5}Mn-C(O)CH{sub 2}R (R = H, OCH{sub 3}, CH{sub 3}) with Et{sub 3}SiH and of cobalt acetyls (CO){sub 3}(PR{sub 3})CoC(O)CH{sub 3} with several monohydrosilanes have been completed. The cobalt acetyls cleanly give ethoxysilanes (not acetaldehyde), and the manganese acyls provide {alpha}-siloxyvinyl complexes Z-(CO){sub 5}Mn-C(OSiEt{sub 3})=CHR (R = H, CH{sub 3}, OCH{sub 3}). Carbonylation and protolytic cleavage of the latter generate pyruvoyl complexes (CO){sub 5}Mn-COCOR (R = CH{sub 3}, CH{sub 2}CH{sub 3}), formally the products of net ``double carbonylation`` sequences. Studies in progress are concerned with how manganese complexes as diverse as (CO){sub 5}Mn-Y [Y = C(O)R, R, BR - but not SiMe{sub 3} or Mn(CO){sub 5}] and ({eta}{sup 3}-C{sub 3}H{sub 5})Mn(CO){sub 2}L [but not CpMn(CO){sub 3} or CpMn(CO){sub 2}({eta}{sup 2}HSiR{sub 3})] function as efficient hydrosilation catalysts towards Cp(CO){sub 2}FeC(O)CH{sub 3}, for example. These reactions cleanly afford fully characterized {alpha}-siloxyethyl complexes Fp-CH(OSiR{sub 3})CH{sub 3} under conditions where typically Rh(1) hydrosilation catalysts are inactive. Several of these manganese complexes also catalytically hydrosilate organic esters, including lactones, to their ethers R-CH{sub 2}OR; these novel ester reductions occur quantitatively at room temperature and appear to be general in scope.

  12. Studies relevant to the catalytic activation of carbon monoxide. Technical progress report, September 1991

    SciTech Connect

    Ford, P.C.

    1992-06-04

    Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.

  13. Total syntheses of zaragozic acids A and C by a carbonyl ylide cycloaddition strategy.

    PubMed

    Hirata, Yuuki; Nakamura, Seiichi; Watanabe, Nobuhide; Kataoka, Osamu; Kurosaki, Takahiro; Anada, Masahiro; Kitagaki, Shinji; Shiro, Motoo; Hashimoto, Shunichi

    2006-12-01

    A carbonyl ylide cycloaddition approach to the squalene synthase inhibitors zaragozic acids A and C is described. The carbonyl ylide precursor 8 was synthesized starting from di-tert-butyl D-tartrate (47) via an eleven-step sequence involving the regioselective reduction of the mono-MPM (MPM=4-methoxybenzyl) ether 48 with LiBH4 and the diastereoselective addition of sodium tert-butyl diazoacetate to alpha-keto ester 10. The reaction of alpha-diazo ester 8 with 3-butyn-2-one (40) in the presence of a catalytic amount of [Rh2(OAc)4] gave the desired cycloadduct 59 as a single diastereomer. The dihydroxylation of enone 59 followed by sequential transformations permitted the construction of the fully functionalized 2,8-dioxabicyclo[3.2.1]octane core 5. Alkene 79 derived from 5 serves as a common precursor to zaragozic acids A (1) and C (2), since the elongation of the C1 alkyl side chain can be attained by olefin cross-metathesis, especially under the influence of Blechert's catalyst (85). PMID:17106907

  14. Computational Mechanistic Study of Thionation of Carbonyl Compounds with Lawesson's Reagent.

    PubMed

    Legnani, L; Toma, L; Caramella, P; Chiacchio, M A; Giofrè, S; Delso, I; Tejero, T; Merino, P

    2016-09-01

    The thionation reaction of carbonyl compounds with Lawesson's reagent (LR) has been studied using density functional theory methods and topological analyses. After dissociation of LR, the reaction takes place through a two-step mechanism involving (i) a concerted cycloaddition between one monomer and the carbonyl compound to form a four-membered intermediate and (ii) a cycloreversion leading to the thiocarbonyl derivative and phenyl(thioxo)phosphine oxide. Topological analyses confirmed the concertedness and asynchronicity of the process. The second step is the rate-limiting one, and the whole process resembles the currently accepted mechanism for the lithium salt-free Wittig reaction. No zwitterionic intermediates are formed during the reaction, although stabilizing electrostatic interactions are present in initial stages. Phenyl(thioxo)phosphine oxide formed in the thionation reaction is capable of performing a second thionation, although with energy barriers higher than the first one. The driving force of the thionation reactions is the formation of trimers from the resulting monomers. In agreement with experimental observations, the amides are the most reactive when compared with esters, aldehydes, and ketones and the reaction is slightly influenced by the polarity of the solvent. Whereas for amides and esters substituents have little effect, aldehydes and ketones are influenced by both steric and electronic effects. PMID:27459366

  15. Selection of appropriate tumour data sets for Benchmark Dose Modelling (BMD) and derivation of a Margin of Exposure (MoE) for substances that are genotoxic and carcinogenic: considerations of biological relevance of tumour type, data quality and uncertainty assessment.

    PubMed

    Edler, Lutz; Hart, Andy; Greaves, Peter; Carthew, Philip; Coulet, Myriam; Boobis, Alan; Williams, Gary M; Smith, Benjamin

    2014-08-01

    This article addresses a number of concepts related to the selection and modelling of carcinogenicity data for the calculation of a Margin of Exposure. It follows up on the recommendations put forward by the International Life Sciences Institute - European branch in 2010 on the application of the Margin of Exposure (MoE) approach to substances in food that are genotoxic and carcinogenic. The aims are to provide practical guidance on the relevance of animal tumour data for human carcinogenic hazard assessment, appropriate selection of tumour data for Benchmark Dose Modelling, and approaches for dealing with the uncertainty associated with the selection of data for modelling and, consequently, the derived Point of Departure (PoD) used to calculate the MoE. Although the concepts outlined in this article are interrelated, the background expertise needed to address each topic varies. For instance, the expertise needed to make a judgement on biological relevance of a specific tumour type is clearly different to that needed to determine the statistical uncertainty around the data used for modelling a benchmark dose. As such, each topic is dealt with separately to allow those with specialised knowledge to target key areas of guidance and provide a more in-depth discussion on each subject for those new to the concept of the Margin of Exposure approach. PMID:24176677

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

    NASA Astrophysics Data System (ADS)

    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%.

  17. Nuclear chemistry. Synthesis and detection of a seaborgium carbonyl complex.

    PubMed

    Even, J; Yakushev, A; Düllmann, Ch E; Haba, H; Asai, M; Sato, T K; Brand, H; Di Nitto, A; Eichler, R; Fan, F L; Hartmann, W; Huang, M; Jäger, E; Kaji, D; Kanaya, J; Kaneya, Y; Khuyagbaatar, J; Kindler, B; Kratz, J V; Krier, J; Kudou, Y; Kurz, N; Lommel, B; Miyashita, S; Morimoto, K; Morita, K; Murakami, M; Nagame, Y; Nitsche, H; Ooe, K; Qin, Z; Schädel, M; Steiner, J; Sumita, T; Takeyama, M; Tanaka, K; Toyoshima, A; Tsukada, K; Türler, A; Usoltsev, I; Wakabayashi, Y; Wang, Y; Wiehl, N; Yamaki, S

    2014-09-19

    Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, and harsh experimental conditions limited the number of experimentally accessible compounds. We applied a gas-phase carbonylation technique previously tested on short-lived molybdenum (Mo) and tungsten (W) isotopes to the preparation of a carbonyl complex of seaborgium, the 106th element. The volatile seaborgium complex showed the same volatility and reactivity with a silicon dioxide surface as those of the hexacarbonyl complexes of the lighter homologs Mo and W. Comparison of the product's adsorption enthalpy with theoretical predictions and data for the lighter congeners supported a Sg(CO)6 formulation. PMID:25237098

  18. Role of Carbonyl Modifications on Aging-Associated Protein Aggregation

    NASA Astrophysics Data System (ADS)

    Tanase, Maya; Urbanska, Aleksandra M.; Zolla, Valerio; Clement, Cristina C.; Huang, Liling; Morozova, Kateryna; Follo, Carlo; Goldberg, Michael; Roda, Barbara; Reschiglian, Pierluigi; Santambrogio, Laura

    2016-01-01

    Protein aggregation is a common biological phenomenon, observed in different physiological and pathological conditions. Decreased protein solubility and a tendency to aggregate is also observed during physiological aging but the causes are currently unknown. Herein we performed a biophysical separation of aging-related high molecular weight aggregates, isolated from the bone marrow and splenic cells of aging mice and followed by biochemical and mass spectrometric analysis. The analysis indicated that compared to younger mice an increase in protein post-translational carbonylation was observed. The causative role of these modifications in inducing protein misfolding and aggregation was determined by inducing carbonyl stress in young mice, which recapitulated the increased protein aggregation observed in old mice. Altogether our analysis indicates that oxidative stress-related post-translational modifications accumulate in the aging proteome and are responsible for increased protein aggregation and altered cell proteostasis.

  19. Hydrogenation of coal liquid utilizing a metal carbonyl catalyst

    DOEpatents

    Feder, Harold M.; Rathke, Jerome W.

    1979-01-01

    Coal liquid having a dissolved transition metal, catalyst as a carbonyl complex such as Co.sub.2 (CO.sub.8) is hydrogenated with hydrogen gas or a hydrogen donor. A dissociating solvent contacts the coal liquid during hydrogenation to form an immiscible liquid mixture at a high carbon monoxide pressure. The dissociating solvent, e.g. ethylene glycol, is of moderate coordinating ability, while sufficiently polar to solvate the transition metal as a complex cation along with a transition metal, carbonyl anion in solution at a decreased carbon monoxide pressure. The carbon monoxide pressure is reduced and the liquids are separated to recover the hydrogenated coal liquid as product. The dissociating solvent with the catalyst in ionized form is recycled to the hydrogenation step at the elevated carbon monoxide pressure for reforming the catalyst complex within fresh coal liquid.

  20. Role of Carbonyl Modifications on Aging-Associated Protein Aggregation

    PubMed Central

    Tanase, Maya; Urbanska, Aleksandra M.; Zolla, Valerio; Clement, Cristina C.; Huang, Liling; Morozova, Kateryna; Follo, Carlo; Goldberg, Michael; Roda, Barbara; Reschiglian, Pierluigi; Santambrogio, Laura

    2016-01-01

    Protein aggregation is a common biological phenomenon, observed in different physiological and pathological conditions. Decreased protein solubility and a tendency to aggregate is also observed during physiological aging but the causes are currently unknown. Herein we performed a biophysical separation of aging-related high molecular weight aggregates, isolated from the bone marrow and splenic cells of aging mice and followed by biochemical and mass spectrometric analysis. The analysis indicated that compared to younger mice an increase in protein post-translational carbonylation was observed. The causative role of these modifications in inducing protein misfolding and aggregation was determined by inducing carbonyl stress in young mice, which recapitulated the increased protein aggregation observed in old mice. Altogether our analysis indicates that oxidative stress-related post-translational modifications accumulate in the aging proteome and are responsible for increased protein aggregation and altered cell proteostasis. PMID:26776680

  1. [Carbonyl stress and oxidatively modified proteins in chronic renal failure].

    PubMed

    Bargnoux, A-S; Morena, M; Badiou, S; Dupuy, A-M; Canaud, B; Cristol, J-P

    2009-01-01

    Oxidative stress is commonly observed in chronic renal failure patients resulting from an unbalance between overproduction of reactive oxygen species and impairement of defense mechanisms. Proteins appear as potential targets of uremia-induced oxidative stress and may undergo qualitative modifications. Proteins could be directly modified by reactive oxygen species which leads to amino acid oxydation and cross-linking. Proteins could be indirectly modified by reactive carbonyl compounds produced by glycoxidation and lipo-peroxidation. The resulting post-traductional modifications are known as carbonyl stress. In addition, thiols could be oxidized or could react with homocystein leading to homocysteinylation. Finally, tyrosin could be oxidized by myeloperoxidase leading to advanced oxidative protein products (AOPP). Oxidatively modified proteins are increased in chronic renal failure patients and may contribute to exacerbate the oxidative stress/inflammation syndrome. They have been involved in long term complications of uremia such as amyloidosis and accelerated atherosclerosis. PMID:19297289

  2. Structural Basis for Substrate Specificity in Human Monomeric Carbonyl Reductases

    PubMed Central

    El-Hawari, Yasser; Dunford, James E.; Kochan, Grazyna; Wsol, Vladimir; Martin, Hans-Joerg; Maser, Edmund; Oppermann, Udo

    2009-01-01

    Carbonyl reduction constitutes a phase I reaction for many xenobiotics and is carried out in mammals mainly by members of two protein families, namely aldo-keto reductases and short-chain dehydrogenases/reductases. In addition to their capacity to reduce xenobiotics, several of the enzymes act on endogenous compounds such as steroids or eicosanoids. One of the major carbonyl reducing enzymes found in humans is carbonyl reductase 1 (CBR1) with a very broad substrate spectrum. A paralog, carbonyl reductase 3 (CBR3) has about 70% sequence identity and has not been sufficiently characterized to date. Screening of a focused xenobiotic compound library revealed that CBR3 has narrower substrate specificity and acts on several orthoquinones, as well as isatin or the anticancer drug oracin. To further investigate structure-activity relationships between these enzymes we crystallized CBR3, performed substrate docking, site-directed mutagenesis and compared its kinetic features to CBR1. Despite high sequence similarities, the active sites differ in shape and surface properties. The data reveal that the differences in substrate specificity are largely due to a short segment of a substrate binding loop comprising critical residues Trp229/Pro230, Ala235/Asp236 as well as part of the active site formed by Met141/Gln142 in CBR1 and CBR3, respectively. The data suggest a minor role in xenobiotic metabolism for CBR3. Enhanced version This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1. PMID:19841672

  3. The modulation of carbonyl reductase 1 by polyphenols.

    PubMed

    Boušová, Iva; Skálová, Lenka; Souček, Pavel; Matoušková, Petra

    2015-01-01

    Carbonyl reductase 1 (CBR1), an enzyme belonging to the short-chain dehydrogenases/reductases family, has been detected in all human tissues. CBR1 catalyzes the reduction of many xenobiotics, including important drugs (e.g. anthracyclines, nabumetone, bupropion, dolasetron) and harmful carbonyls and quinones. Moreover, it participates in the metabolism of a number of endogenous compounds and it may play a role in certain pathologies. Plant polyphenols are not only present in many human food sources, but are also a component of many popular dietary supplements and herbal medicines. Many studies reviewed herein have demonstrated the potency of certain flavonoids, stilbenes and curcuminoids in the inhibition of the activity of CBR1. Interactions of these polyphenols with transcriptional factors, which regulate CBR1 expression, have also been reported in several studies. As CBR1 plays an important role in drug metabolism as well as in the protection of the organism against potentially harmful carbonyls, the modulation of its expression/activity may have significant pharmacological and/or toxicological consequences. Some polyphenols (e.g. luteolin, apigenin and curcumin) have been shown to be very potent CBR1 inhibitors. The inhibition of CBR1 seems useful regarding the increased efficacy of anthracycline therapy, but it may cause the worse detoxification of reactive carbonyls. Nevertheless, all known information about the interactions of polyphenols with CBR1 have only been based on the results of in vitro studies. With respect to the high importance of CBR1 and the frequent consumption of polyphenols, in vivo studies would be very helpful for the evaluation of risks/benefits of polyphenol interactions with CBR1. PMID:26415702

  4. A simple and high collection efficiency sampling method for monitoring of carbonyl compounds in a workplace environment.

    PubMed

    Bunkoed, Opas; Thavarungkul, Panote; Thammakhet, Chongdee; Kanatharana, Proespichaya

    2012-01-01

    A simple and high collection efficiency sampling method was developed for the monitoring of carbonyl compounds, i.e., formaldehyde, acetaldehyde, benzaldehyde, acetone and butanone. The determination is based on the reaction of these compounds in a sensitive absorbing solution of 2,4-DNPH. After the completion of the reaction the derivatives were analyzed by the HPLC system without any post sample preparation. The operation conditions of the proposed method were optimized to obtain the highest sampling efficiency within a short analysis time. The collection efficiency for all compounds was in the range of 95 ± 3 % to 99 ± 4 % and the relative standard deviations (n = 15) were less than 10 %. This method was validated and applied to monitor carbonyl compounds in air samples from an occupational environment, the adhesive industry. Formaldehyde was found to be the most abundant carbonyl compound (64 ± 8 to 250 ± 20 ppbv), followed by acetaldehyde (ND to 24 ± 6 ppbv), acetone (ND to 21 ± 5 ppbv) and benzaldehyde (ND to 27 ± 7 ppbv). The sampling of air directly into the absorbing solution was compared with the conventional method of using an adsorbent cartridge, and the results were in good agreement (P > 0.05). PMID:22242868

  5. Mechanism and biological relevance of blue-light (420-453 nm)-induced nonenzymatic nitric oxide generation from photolabile nitric oxide derivates in human skin in vitro and in vivo.

    PubMed

    Opländer, Christian; Deck, Annika; Volkmar, Christine M; Kirsch, Michael; Liebmann, Jörg; Born, Matthias; van Abeelen, Frank; van Faassen, Ernst E; Kröncke, Klaus-Dietrich; Windolf, Joachim; Suschek, Christoph V

    2013-12-01

    Human skin contains photolabile nitric oxide (NO) derivates such as nitrite and S-nitrosothiols, which upon UVA radiation decompose under high-output NO formation and exert NO-specific biological responses such as increased local blood flow or reduced blood pressure. To avoid the injurious effects of UVA radiation, we here investigated the mechanism and biological relevance of blue-light (420-453 nm)-induced nonenzymatic NO generation from photolabile nitric oxide derivates in human skin in vitro and in vivo. As quantified by chemiluminescence detection (CLD), at physiological pH blue light at 420 or 453 nm induced a significant NO formation from S-nitrosoalbumin and also from aqueous nitrite solutions by a to-date not entirely identified Cu(1+)-dependent mechanism. As detected by electron paramagnetic resonance spectrometry in vitro with human skin specimens, blue light irradiation significantly increased the intradermal levels of free NO. As detected by CLD in vivo in healthy volunteers, irradiation of human skin with blue light induced a significant emanation of NO from the irradiated skin area as well as a significant translocation of NO from the skin surface into the underlying tissue. In parallel, blue light irradiation caused a rapid and significant rise in local cutaneous blood flow as detected noninvasively by using micro-light-guide spectrophotometry. Irradiation of human skin with moderate doses of blue light caused a significant increase in enzyme-independent cutaneous NO formation as well as NO-dependent local biological responses, i.e., increased blood flow. The effects were attributed to blue-light-induced release of NO from cutaneous photolabile NO derivates. Thus, in contrast to UVA, blue-light-induced NO generation might be therapeutically used in the treatment of systemic and local hemodynamic disorders that are based on impaired physiological NO production or bioavailability. PMID:24121056

  6. Protein Carbonylation, Mitochondrial Dysfunction, and Insulin Resistance123

    PubMed Central

    Frohnert, Brigitte I.; Bernlohr, David A.

    2013-01-01

    Oxidative stress has been identified as a common mechanism for cellular damage and dysfunction in a wide variety of disease states. Current understanding of the metabolic changes associated with obesity and the development of insulin resistance has focused on the role of oxidative stress and its interaction with inflammatory processes at both the tissue and organismal level. Obesity-related oxidative stress is an important contributing factor in the development of insulin resistance in the adipocyte as well as the myocyte. Moreover, oxidative stress has been linked to mitochondrial dysfunction, and this is thought to play a role in the metabolic defects associated with oxidative stress. Of the various effects of oxidative stress, protein carbonylation has been identified as a potential mechanism underlying mitochondrial dysfunction. As such, this review focuses on the relationship between protein carbonylation and mitochondrial biology and addresses those features that point to either the causal or casual relationship of lipid peroxidation–induced protein carbonylation as a determining factor in mitochondrial dysfunction. PMID:23493532

  7. 40 CFR 721.10409 - Poly(oxyalkylenediyl), .alpha.-[[[methyl-3-[[[(polyfluoroalkyl)oxy]carbonyl] amino]phenyl]amino...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Poly(oxyalkylenediyl), .alpha...(oxyalkylenediyl), .alpha.- carbonyl] amino]phenyl]amino]carbonyl]- .omega.-methoxy-(generic). (a) Chemical... as poly(oxyalkylenediyl), .alpha.- carbonyl]amino]phenyl]amino] carbonyl]-.omega.-methoxy- (PMN...

  8. 40 CFR 721.10409 - Poly(oxyalkylenediyl), .alpha.-[[[methyl-3-[[[(polyfluoroalkyl) oxy]carbonyl]amino]phenyl]amino...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Poly(oxyalkylenediyl), .alpha...(oxyalkylenediyl), .alpha.- carbonyl]amino]phenyl]amino] carbonyl]-.omega.-methoxy- (generic). (a) Chemical... as poly(oxyalkylenediyl), .alpha.- carbonyl]amino]phenyl]amino] carbonyl]-.omega.-methoxy- (PMN...

  9. Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C, 15N-labeled peptides and proteins

    NASA Astrophysics Data System (ADS)

    Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

    2010-03-01

    In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly 13C, 15N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22 kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600 MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i - 2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed.

  10. Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C,15N-labeled peptides and proteins.

    PubMed

    Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

    2010-03-01

    In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly (13)C,(15)N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i-2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed. PMID:20060344

  11. [Chemical Characteristics and Sources of Atmospheric Carbonyls During the 2014 Beijing APEC].

    PubMed

    He, Xiao-lang; Tan, Ji-hua; Guo, Song-jun; Ma, Yong-liang; He, Ke-bin

    2016-03-15

    Pollution characteristic and variation trend of atmospheric carbonyls were investigated in November during the 2014 Beijing APEC. Formaldehyde, acetaldehyde and acetone were the dominant carbonyls, accounting for 82.66% of total carbonyls, and especially, formaldehyde accounted for 40.12% of total carbonyls. Atmospheric concentrations of total carbonyls decreased by around 64.10% after the clean air policy was carried out during the Beijing APEC, and the variation trend of carbonyls showed a similar pattern to those of other pollutants like PM₂.₅ during the APEC. Strong correlations (R² of 0.67-0.98) were observed among formaldehyde, acetaldehyde, acetone and total carbonyls during and after the APEC, indicating that they had similar sources; however, poor correlations (R² of -0.11-0.42 and 0.16-0.94, respectively) were observed before the APEC, implying different emission sources for ambient carbonyls. The calculated ratios of C1/C2, C2/C3 and OC/EC indicated that both vehicles and coal emissions were responsible for atmospheric carbonyls before the APEC, and emissions from coal burning were the major contributor to atmospheric carbonyls during and after the APEC, especially after the APEC. PMID:27337869

  12. The Personal Relevance of the Social Studies.

    ERIC Educational Resources Information Center

    VanSickle, Ronald L.

    1990-01-01

    Conceptualizes a personal-relevance framework derived from Ronald L. VanSickle's five areas of life integrated with four general motivating goals from Abraham Maslow's hierarchy of needs and Richard and Patricia Schmuck's social motivation theory. Illustrates ways to apply the personal relevance framework to make social studies more relevant to…

  13. Line intensities and collisional-broadening parameters for the nu4 and nu6 bands of carbonyl fluoride

    NASA Technical Reports Server (NTRS)

    May, Randy D.

    1992-01-01

    Line intensities, air- and self-broadening parameters have been measured for selected lines in the nu4 (1243/cm) and nu6 (774/cm) bands of carbonyl fluoride at 296 and 215 K using a tunable diode-laser spectrometer. Measured line intensities are in good agreement +/- 6 percent with recently reported values derived from rotational analyses of the nu4 and nu6 bands. The measured average air-broadening coefficient at 296 K also agrees well (+/- 5 percent) with N2-broadening coefficients determined from microwave studies, while the average self-broadening coefficient reported here is smaller than a previously reported value by 45 percent.

  14. Palladium-Catalyzed Regioselective Difluoroalkylation and Carbonylation of Alkynes.

    PubMed

    Wang, Qiang; He, Yu-Tao; Zhao, Jia-Hui; Qiu, Yi-Feng; Zheng, Lan; Hu, Jing-Yuan; Yang, Yu-Chen; Liu, Xue-Yuan; Liang, Yong-Min

    2016-06-01

    A novel, four-component synthetic strategy to synthesize a series of β-difluoroalkyl unsaturated esters/amides with high regioslectivity is described. This Pd-catalyzed difluoroalkylation and carbonylation reaction can be carried out with simple starting materials. Through this protocol, two new C-C bonds (including one C-CF2 bond) and one C-O(N) bond are constructed simultaneously in a single step. The synthetic utility of this reaction system has been certified by the applicability to a wide scope of alkynes and nucleophiles. Preliminary mechanistic studies suggest that the difluoroalkyl radical pathway is involved in this reaction. PMID:27191858

  15. Detoxification reactions: relevance to aging

    PubMed Central

    Zimniak, Piotr

    2008-01-01

    It is widely (although not universally) accepted that organismal aging is the result of two opposing forces: (i) processes that destabilize the organism and increase the probability of death, and (ii) longevity assurance mechanisms that prevent, repair, or contain damage. Processes of the first group are often chemical and physico-chemical in nature, and are either inevitable or only under marginal biological control. In contrast, protective mechanisms are genetically determined and are subject to natural selection. Life span is therefore largely dependent on the investment into protective mechanisms which evolve to optimize reproductive fitness. Recent data indicate that toxicants, both environmental and generated endogenously by metabolism, are major contributors to macromolecular damage and physiological dysregulation that contribute to aging; electrophilic carbonyl compounds derived from lipid peroxidation appear to be particularly important. As a consequence, detoxification mechanisms, including the removal of electrophiles by glutathione transferase-catalyzed conjugation, are major longevity assurance mechanisms. The expression of multiple detoxification enzymes, each with a significant but relatively modest effect on longevity, is coordinately regulated by signaling pathways such as insulin/insulin-like signaling, explaining the large effect of such pathways on life span. The major aging-related toxicants and their cognate detoxification systems are discussed in this review. PMID:18547875

  16. Two-dimensional gel electrophoretic detection of protein carbonyls derivatized with biotin-hydrazide.

    PubMed

    Wu, Jinzi; Luo, Xiaoting; Jing, Siqun; Yan, Liang-Jun

    2016-04-15

    Protein carbonyls are protein oxidation products that are often used to measure the magnitude of protein oxidative damage induced by reactive oxygen or reactive nitrogen species. Protein carbonyls have been found to be elevated during aging and in age-related diseases such as stroke, diabetes, and neurodegenerative diseases. In the present article, we provide detailed protocols for detection of mitochondrial protein carbonyls labeled with biotin-hydrazide followed by 2-dimensional isoelectric focusing (IEF)/SDS-PAGE and Western blotting probed with horse-radish peroxidase-conjugated streptavidin. The presented procedures can also be modified for detection of carbonylation of non-mitochondrial proteins. PMID:26590475

  17. Borane-Catalyzed Reductive α-Silylation of Conjugated Esters and Amides Leaving Carbonyl Groups Intact.

    PubMed

    Kim, Youngchan; Chang, Sukbok

    2016-01-01

    Described herein is the development of the B(C6F5)3-catalyzed hydrosilylation of α,β-unsaturated esters and amides to afford synthetically valuable α-silyl carbonyl products. The α-silylation occurs chemoselectively, thus leaving the labile carbonyl groups intact. The reaction features a broad scope of both acyclic and cyclic substrates, and the synthetic utility of the obtained α-silyl carbonyl products is also demonstrated. Mechanistic studies revealed two operative steps: fast 1,4-hydrosilylation of conjugated carbonyls and then slow silyl group migration of a silyl ether intermediate. PMID:26549843

  18. The carbonyl oxide-aldehyde complex: a new intermediate of the ozonolysis reaction

    NASA Astrophysics Data System (ADS)

    Cremer, Dieter; Kraka, Elfi; McKee, M. L.; Radharkrishnan, T. P.

    1991-12-01

    MP4(SDQ)/6-31G (d,p) calculations suggest that the ozonolysis of alkenes in solution phase does not proceed via carbonyl oxide, but via a dipole complex between aldehyde and carbonyl oxide, which is 9 kcal/mol more stable than the separated molecules. The dipole complex is probably formed in the solvent cage upon decomposition of primary ozonide to aldehyde and carbonyl oxide. Rotation of either aldehyde or carbonyl oxide in the solvent cage leads to an antiparallel alignment of molecular dipole moments and dipole-dipole attraction.

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

    DOEpatents

    Marling, John B.

    1981-01-01

    A method for producing a deuterium enriched material by photoinduced dissociation which uses as the working material a gas phase photolytically dissociable organic carbonyl compound containing at least one hydrogen atom bonded to an atom which is adjacent to a carbonyl group and consisting of molecules wherein said hydrogen atom is present as deuterium and molecules wherein said hydrogen atom is present as another isotope of hydrogen. The organic carbonyl compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of the deuterium containing species to yield a deuterium enriched stable molecular product. Undissociated carbonyl compound, depleted in deuterium, is preferably redeuterated for reuse.

  20. Indoor and outdoor carbonyl compounds in the hotel ballrooms in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Feng, Yanli; Wen, Sheng; Wang, Xinming; Sheng, Guoying; He, Qiusheng; Tang, Jianhui; Fu, Jiamo

    Twenty-one carbonyl compounds were measured simultaneously at four hotel ballrooms in urban Guangzhou during the autumn, 2002. In each ballroom, measurements were carried out in business hours in the evening (20:30-24:00) on 7 consecutive days without any disturbance of the ballroom's normal operation. Nineteen out of the 21 target carbonyl compounds were identified in indoor and outdoor air. In the outdoor environment, formaldehyde was the most abundant carbonyl, followed by acetaldehyde, and there existed a strong correlation between formaldehyde and acetaldehyde. In the indoor air, however, acetaldehyde was the most abundant carbonyl, its concentrations seemed to be affected significantly by smoking. The indoor concentrations of carbonyls were found higher than their outdoor counterparts with only a few exceptions. Further studies concerning the indoor/outdoor ratios and mutual correlation of the carbonyls indicated that apart from direct emission from indoor materials and infiltration of outdoor air, other anthropogenic sources, e.g. tobacco smoke, also significantly contributed to carbonyl compounds. The possible sources of some high molecular weight carbonyls, e.g. nonanaldehyde, were also discussed briefly. Preliminary estimate of the exposures and risks due to carbonyls in the ballrooms was made, which indicated that long-term exposure in such places might cause increased chance of developing cancers.

  1. Analysis of dynamic protein carbonylation in rice embryo during germination through AP-SWATH.

    PubMed

    Zhang, Hui; He, Dongli; Yu, Jianlan; Li, Ming; Damaris, Rebecca Njeri; Gupta, Ravi; Kim, Sun Tae; Yang, Pingfang

    2016-03-01

    Seed germination is an important aspect of the plant life cycle, during which, reactive oxygen species (ROS) accumulate. The accumulation of ROS results in an increase in protein oxidation of which carbonylation is the most canonical one. However, there is insufficient information concerning protein oxidation, especially carbonylation and its contribution to seed germination. In this study, biotin hydrazide labeled chromatography combined with sequential window acquisition of all theoretical fragment ion spectra (SWATH) method was used to analyze the dynamic pattern of protein carbonylation in rice embryos during germination. A total of 1872 unique proteins were quantified, among which 288 carbonylated peptides corresponding to 144 proteins were determined based on the filtering through mass shifts of modified amino acids. In addition, 66 carbonylated proteins were further analyzed based on their carbonylation intensity in four stages of germination. These identified carbonylated proteins were mainly involved in maintaining the levels of ROS, abscisic acid and seed reserves. Remarkably, a peroxiredoxin was found with 23 unique carbonylated peptides, and the expression of which was consistent with its increased activity. This study describes the dynamic pattern of carbonylated proteins during seed germination, and may help to further understand the biochemical mechanisms on this process. PMID:26801057

  2. Total Synthesis of (±)-Englerin A Using An Intermolecular [3+2] Cycloaddition Reaction of Platinum-Containing Carbonyl Ylide.

    PubMed

    Kusama, Hiroyuki; Tazawa, Aoi; Ishida, Kento; Iwasawa, Nobuharu

    2016-01-01

    Total synthesis of (±)-Englerin A has been achieved starting from γ,δ-ynone 5 in 14 steps. The key feature of this synthesis is the highly efficient and stereoselective preparation of 8-oxabicyclo[3.2.1]octane derivative 6, a core skeleton of Englerin A, based on an inverse electron-demand [3+2] cycloaddition reaction of the platinum-containing carbonyl ylide, which was developed in our laboratory. PMID:26377511

  3. Multicomponent Synthesis of Uracil Analogues Promoted by Pd-Catalyzed Carbonylation of α-Chloroketones in the Presence of Isocyanates and Amines.

    PubMed

    Perrone, Serena; Capua, Martina; Salomone, Antonio; Troisi, Luigino

    2015-08-21

    A short and efficient one-pot synthesis of uracil derivatives with a high structural variability is described. The process is a multicomponent reaction based on a palladium-catalyzed carbonylation of α-chloroketones in the presence of primary amines and isocyanates. In most cases, when the formation of unsymmetrical N,N'-disubstituted uracil derivatives can occur, the methodology demonstrates to be highly regioselective. A mechanistic hypothesis involving β-dicarbonyl palladium intermediates and urea derivatives, generated in situ, has been discussed. PMID:26172334

  4. Carbonyl reductase of dog liver: purification, properties, and kinetic mechanism.

    PubMed

    Hara, A; Nakayama, T; Deyashiki, Y; Kariya, K; Sawada, H

    1986-01-01

    A carbonyl reductase has been extracted into 0.5 M KCl from dog liver and purified to apparent homogeneity by a three-step procedure consisting of chromatography on CM-Sephadex, Matrex green A, and Sephadex G-100 in high-ionic-strength buffers. The enzyme is a dimer composed of two identical subunits of molecular weight 27,000. The pH optimum is 5.5 and the isoelectric point of the enzyme is 9.3. The enzyme reduces aromatic ketones and aldehydes; the aromatic ketones with adjacent medium alkyl chains are the best substrates. Quinones, ketosteroids, prostaglandins, and aliphatic carbonyl compounds are poor or inactive substrates for the enzyme. As a cofactor the enzyme utilizes NADPH, the pro-S hydrogen atom of which is transferred to the substrate. Two moles of NADPH bind to one mole of the enzyme molecule, causing a blue shift and enhancement of the cofactor fluorescence. The reductase reaction is reversible and the equilibrium constant determined at pH 7.0 is 12.8. Steady-state kinetic measurements in both directions suggest that the reaction proceeds through a di-iso ordered bi-bi mechanism. PMID:3511844

  5. Prosthetic iodination methods for radiolabeling of carbonyl moieties

    SciTech Connect

    Barakat, B.M.A.

    1987-01-01

    The demonstrable need for an indirect, prosthetic-group, radioiodination of carbonyl-containing biomolecules such as ketosteroids, carbohydrates, gangliosides, glycoproteins and aldehydo- and keto-drugs. This need has been addressed by developing a route to iodinated (radioiodination) aryl hydrazides which are subsequently condensed with carbonyl-containing moieties. This dissertation is directed at improving the utility of this reaction and at comparing the hydrolytic stability of the resulting hydrazones to that of similar tyramine imines, a type presently employed in indirect radioiodinations. The aryl carboxylic acid hydrazones were virtually inert to hydrolysis under simulated physiological conditions which caused imine bond rupture. Further improvements to this new prosthetic labeling method were sought in simplifying its two-step, acid-catalyzed cleavage of triazenooxadiazoles (the protected, pre-labeling form of the aryl carboxylic acid hydrazides) to the iodinated hydrazide. Synthetic procedures were explored which might yield non-conjugated aryl oxadiazoles--bearing methylenes inserted between the phenyl and the heterocyclic ring--in the expectation that these substances would be less stable and would hydrolyze in a single-acid-catalyzed step. Four synthetic pathways to amino (or nitro) aryl-methyl oxadiazoles could not be advanced beyond the open-chain precursors of the heterocyclics. Pyrolysis, thermolysis, and catalyzed cyclization reagents could not effect ring closure. A method was developed, however, to an oxadiazolone which can serve as a protective functionality for the iodinated aryl acid hydrazides.

  6. Transition-metal-catalyzed carbonylation reactions of olefins and alkynes: a personal account.

    PubMed

    Wu, Xiao-Feng; Fang, Xianjie; Wu, Lipeng; Jackstell, Ralf; Neumann, Helfried; Beller, Matthias

    2014-04-15

    Carbon monoxide was discovered and identified in the 18th century. Since the first applications in industry 80 years ago, academic and industrial laboratories have broadly explored CO's use in chemical reactions. Today organic chemists routinely employ CO in organic chemistry to synthesize all kinds of carbonyl compounds. Despite all these achievements and a century of carbonylation catalysis, many important research questions and challenges remain. Notably, apart from academic developments, industry applies carbonylation reactions with CO on bulk scale. In fact, today the largest applications of homogeneous catalysis (regarding scale) are carbonylation reactions, especially hydroformylations. In addition, the vast majority of acetic acid is produced via carbonylation of methanol (Monsanto or Cativa process). The carbonylation of olefins/alkynes with nucleophiles, such as alcohols and amines, represent another important type of such reactions. In this Account, we discuss our work on various carbonylations of unsaturated compounds and related reactions. Rhodium-catalyzed isomerization and hydroformylation reactions of internal olefins provide straightforward access to higher value aldehydes. Catalytic hydroaminomethylations offer an ideal way to synthesize substituted amines and even heterocycles directly. More recently, our group has also developed so-called alternative metal catalysts based on iridium, ruthenium, and iron. What about the future of carbonylation reactions? CO is already one of the most versatile C1 building blocks for organic synthesis and is widely used in industry. However, because of CO's high toxicity and gaseous nature, organic chemists are often reluctant to apply carbonylations more frequently. In addition, new regulations have recently made the transportation of carbon monoxide more difficult. Hence, researchers will need to develop and more frequently use practical and benign CO-generating reagents. Apart from formates, alcohols, and metal

  7. Application of a data-processing model to determine the optimal sampling conditions for liquid phase trapping of atmospheric carbonyl compounds.

    PubMed

    Perraud, V; François, S; Wortham, H; Jourdain, B; Houdier, S; Kardos, N

    2008-08-15

    The reactivity of two fluorescent derivatization reagents, 2-diphenyl-1,3-indandione-1-hydrazone (DIH) and 2-aminooxy-N-[3-(5-dimethylamino-naphtalene-1-sulfonamino)-propyl]-acetamide (dansylacetamidooxyamine, DNSAOA), was studied towards selected atmospheric carbonyl compounds. The results were compared to those obtained using the 2,4-dinitrophenylhydrazine (2,4-DNPH) UV-vis reagent, a standard well-established technique used to detect atmospheric carbonyl compounds. The experimental rate constant were integrated into a data-processing model developed in the laboratory to simulate the trapping efficiencies of a mist chamber device as a function of temperature, reagent and solvent type among others. The results showed that in an aqueous solution, DNSAOA exhibits a higher reactivity towards carbonyl compounds without the addition of an acidic catalyst than 2,4-DNPH. It was observed that DNSAOA can trap efficiently water-soluble gaseous compounds (for example formaldehyde). However, because of a high initial contamination of the reagent caused by the synthesis procedure used in this work, DNSAOA cannot be used in high concentrations. As a result, very low trapping efficiencies of less reactive water-insoluble gaseous compounds (acetone) using DNSAOA are observed. However, the use of an organic solvent such as acetonitrile improved the trapping efficiencies of the carbonyl compounds. In this case, using DIH as the derivatization reagent (DNSAOA is not soluble in acetonitrile), trapping efficiencies greater than 95% were obtained, similar to 2,4-DNPH. Moreover, fluorescence associated with DIH derivatives (detection limits 3.33 x 10(-8)M and 1.72x10(-8)M for formaldehyde and acetone, respectively) is further advantage of this method for the determination of carbonyl compounds in complex matrix compared to the classical UV-vis detection method (detection limits 3.20 x 10(-8)M and 2.9 x 10(-8)M for formaldehyde and acetone, respectively). PMID:18656665

  8. Denuder sampling techniques for the determination of gas-phase carbonyl compounds: a comparison and characterisation of in situ and ex situ derivatisation methods.

    PubMed

    Kahnt, Ariane; Iinuma, Yoshiteru; Böge, Olaf; Mutzel, Anke; Herrmann, Hartmut

    2011-05-15

    Two denuder sampling techniques have been compared for the analysis of gaseous carbonyl compounds. One type of denuder was coated with XAD-4 resin and the other type of denuder was coated with XAD-4 and 2,4-dinitrophenylhydrazine (DNPH) to derivatise gaseous carbonyl compounds to their hydrazone forms simultaneously. A detailed protocol for the denuder coating procedure is described. The collection efficiency under dry (RH <3%) and humid conditions (RH 50%) as well as filter positive artefacts were evaluated. The XAD-4/DNPH coated denuders showed significantly less break-through potential and hence collection than the XAD-4-only coated denuders. The performance of the XAD-4/DNPH denuder was better under humid conditions with no detected break-through for hydroxyacetone, methacrolein, methylglyoxal, campholenic aldehyde and nopinone. Calibration experiments were performed in a simulation chamber and carbonyl-hydrazone concentrations determined in the extracts of both the denuder types were related to the mixing ratios of gaseous carbonyl compounds in the chamber to overcome losses and errors associating with the denuder sampling, extraction and sample preparation. The application of on-tube conversion for the XAD-4/DNPH denuders resulted in higher R(2) values than the XAD-4 denuder, ranging up to 0.991 for nopinone. The XAD-4-only coated denuders showed acceptable calibration curves only for lower vapour pressure carbonyl compounds though larger relative standard deviations (RSD) were observed. Carbonyl compounds that were formed during the oxidation of nopinone were collected using the XAD-4/DNPH denuders. The results showed that the denuder sampling device was able to provide reproducible nopinone mixing ratios that remained in the chamber after about 1h of the oxidation. One isomer of oxo-nopinones was tentatively identified from off-line HPLC/(-)ESI-TOFMS analysis. Based on the TOFMS response of the nopinone-DNPH derivative, the oxo-nopinone molar yield of 0.7

  9. Earthdata Search: The Relevance of Relevance

    NASA Technical Reports Server (NTRS)

    Quinn, Patrick

    2016-01-01

    Through recent usability studies, the issue of relevance became increasingly clear in the Earthdata Search Client. After all, if a user can't find the data they are looking for, nothing else we do matters. This presentation walks through usability testing findings and recent relevance improvements made to the Earthdata Search Client.

  10. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite.

    PubMed

    Rasmussen, Dominik B; Christensen, Jakob M; Temel, Burcin; Studt, Felix; Moses, Poul Georg; Rossmeisl, Jan; Riisager, Anders; Jensen, Anker D

    2015-06-15

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated acetic acid (CH2DCOOD), when D2O is introduced in the feed during the carbonylation reaction. PMID:25967363

  11. 40 CFR 721.10705 - Aromatic amine with cyclo amino carbonyls (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic amine with cyclo amino... Specific Chemical Substances § 721.10705 Aromatic amine with cyclo amino carbonyls (generic). (a) Chemical... as aromatic amine with cyclo amino carbonyls (PMN P-12-572) is subject to reporting under...

  12. In Situ Derivatization and Quantification of Seven Carbonyls in Cigarette Mainstream Smoke.

    PubMed

    Ding, Yan S; Yan, Xizheng; Wong, Joshua; Chan, Michele; Watson, Clifford H

    2016-01-19

    Carbonyls, especially aldehydes, are a group of harmful volatile organic compounds that are found in tobacco smoke. Seven carbonyls are listed on the FDA's harmful and potential harmful constituents list for tobacco or tobacco smoke. Carbonyls have reactive functional groups and thus are challenging to quantitatively measure in cigarette smoke. The traditional method of measuring carbonyls in smoke involves solvent-filled impinger trapping and derivatization. This procedure is labor-intensive and generates significant volumes of hazardous waste. We have developed a new method to efficiently derivatize and trap carbonyls from mainstream smoke in situ on Cambridge filter pads. The derivatized carbonyls are extracted from the pads and subsequently quantified by ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry. The new method has been validated and applied to research and commercial cigarettes. Carbonyl yields from research cigarettes are comparable to those from other published literature data. With a convenient smoke collection apparatus, a 4 min sample analysis time, and a low- or submicrogram detection limit, this new method not only simplifies and speeds the detection of an important class of chemical constituents in mainstream smoke but also reduces reactive losses and provides a more accurate assessment of carbonyl levels in smoke. Excellent accuracy (average 98%) and precision (14% average relative standard deviation in research cigarettes) ensure this new method's sufficient fidelity to characterize conventional combusted tobacco products, with potential application toward new or emerging products. PMID:26700249

  13. Metal-atom fluorescence from the quenching of metastable rare gases by metal carbonyls

    SciTech Connect

    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.

  14. PROCESS OF COATING WITH NICKEL BY THE DECOMPOSITION OF NICKEL CARBONYL

    DOEpatents

    Hoover, T.B.

    1959-04-01

    An improved process is presented for the deposition of nickel coatings by the thermal decomposition of nickel carbonyl vapor. The improvement consists in incorporating a small amount of hydrogen sulfide gas in the nickel carbonyl plating gas. It is postulated that the hydrogen sulfide functions as a catalyst. i

  15. Protective mechanisms of Cucumis sativus in diabetes-related modelsof oxidative stress and carbonyl stress

    PubMed Central

    Heidari, Himan; Kamalinejad, Mohammad; Noubarani, Maryam; Rahmati, Mokhtar; Jafarian, Iman; Adiban, Hasan; Eskandari, Mohammad Reza

    2016-01-01

    Introduction: Oxidative stress and carbonyl stress have essential mediatory roles in the development of diabetes and its related complications through increasing free radicals production and impairing antioxidant defense systems. Different chemical and natural compounds have been suggested for decreasing such disorders associated with diabetes. The objectives of the present study were to investigate the protective effects of Cucumis sativus (C. sativus) fruit (cucumber) in oxidative and carbonyl stress models. These diabetes-related models with overproduction of reactive oxygen species (ROS) and reactive carbonyl species (RCS) simulate conditions observed in chronic hyperglycemia. Methods: Cytotoxicity induced by cumene hydroperoxide (oxidative stress model) or glyoxal (carbonyl stress model) were measured and the protective effects of C. sativus were evaluated using freshly isolated rat hepatocytes. Results: Aqueous extract of C. sativus fruit (40 μg/mL) prevented all cytotoxicity markers in both the oxidative and carbonyl stress models including cell lysis, ROS formation, membrane lipid peroxidation, depletion of glutathione, mitochondrial membrane potential decline, lysosomal labialization, and proteolysis. The extract also protected hepatocytes from protein carbonylation induced by glyoxal. Our results indicated that C. sativus is able to prevent oxidative stress and carbonyl stress in the isolated hepatocytes. Conclusion: It can be concluded that C. sativus has protective effects in diabetes complications and can be considered a safe and suitable candidate for decreasing the oxidative stress and carbonyl stress that is typically observed in diabetes mellitus. PMID:27340622

  16. Versatile, mild, and selective reduction of various carbonyl groups using an electron-deficient boron catalyst.

    PubMed

    Lucas, Katherine M; Kleman, Adam F; Sadergaski, Luke R; Jolly, Caitlyn L; Bollinger, Brady S; Mackesey, Brittany L; McGrath, Nicholas A

    2016-06-15

    A mild and selective new method was discovered to reduce acetanilides and other carbonyl compounds. Unlike sodium borohydride, which is selective in reducing aldehydes and ketones, this new protocol is uniquely selective in reducing acetanilides and nitriles over other carbonyl containing functional groups. Additionally, β-ketoamides were shown to be reduced at the ketone preferentially over the amide. PMID:27005847

  17. Characterization of modified proteins in plasma from a subtype of schizophrenia based on carbonyl stress: Protein carbonyl is a possible biomarker of psychiatric disorders.

    PubMed

    Koike, Shin; Kayama, Tasuku; Arai, Makoto; Horiuchi, Yasue; Kobori, Akiko; Miyashita, Mitsuhiro; Itokawa, Masanari; Ogasawara, Yuki

    2015-11-13

    Although it's well known that protein carbonyl (PCO) and advanced glycation end-products (AGEs) levels are elevated in plasma from patients with renal dysfunction, we recently identified patients who had no renal dysfunction but possessed high levels of plasma pentosidine (PEN), which is an AGEs, and low vitamin B6 levels in serum. In this study, we investigated the status of carbonyl stress to characterize the subtype of schizophrenia. When plasma samples were subjected to Western blot analysis for various AGEs, clear differences were only observed with the anti-PEN antibody in the plasma from schizophrenic patients. Moreover, we determined the formation of protein carbonyl (PCO), a typical indicator of carbonyl stress, occurred prior to the accumulation of PEN in the plasma of schizophrenic patients. PCO levels in the plasma from schizophrenic patients were significantly higher than that from healthy subjects. Western blots analysis clearly showed that albumin and IgG were markedly carbonylated in the plasma of some patients. Thus, PCOs may be a novel marker of carbonyl stress-type schizophrenia in addition to albumin containing PEN structure. PMID:26431870

  18. Protein carbonylation after traumatic brain injury: cell specificity, regional susceptibility, and gender differences.

    PubMed

    Lazarus, Rachel C; Buonora, John E; Jacobowitz, David M; Mueller, Gregory P

    2015-01-01

    Protein carbonylation is a well-documented and quantifiable consequence of oxidative stress in several neuropathologies, including multiple sclerosis, Alzheimer׳s disease, and Parkinson׳s disease. Although oxidative stress is a hallmark of traumatic brain injury (TBI), little work has explored the specific neural regions and cell types in which protein carbonylation occurs. Furthermore, the effect of gender on protein carbonylation after TBI has not been studied. The present investigation was designed to determine the regional and cell specificity of TBI-induced protein carbonylation and how this response to injury is affected by gender. Immunohistochemistry was used to visualize protein carbonylation in the brains of adult male and female Sprague-Dawley rats subjected to controlled cortical impact (CCI) as an injury model of TBI. Cell-specific markers were used to colocalize the presence of carbonylated proteins in specific cell types, including astrocytes, neurons, microglia, and oligodendrocytes. Results also indicated that the injury lesion site, ventral portion of the dorsal third ventricle, and ventricular lining above the median eminence showed dramatic increases in protein carbonylation after injury. Specifically, astrocytes and limited regions of ependymal cells adjacent to the dorsal third ventricle and the median eminence were most susceptible to postinjury protein carbonylation. However, these patterns of differential susceptibility to protein carbonylation were gender dependent, with males showing significantly greater protein carbonylation at sites distant from the lesion. Proteomic analyses were also conducted and determined that the proteins most affected by carbonylation in response to TBI include glial fibrillary acidic protein, dihydropyrimidase-related protein 2, fructose-bisphosphate aldolase C, and fructose-bisphosphate aldolase A. Many other proteins, however, were not carbonylated by CCI. These findings indicate that there is both regional

  19. Development and application of a sensitive method to determine concentrations of acrolein and other carbonyls in ambient air.

    PubMed

    Cahill, Thomas M; Charles, M Judith; Seaman, Vincent Y

    2010-05-01

    Acrolein, an unsaturated aldehyde, has been identified as one of the most important toxic air pollutants in recent assessments of ambient air quality. Current methods for determining acrolein concentrations, however, suffer from poor sensitivity, selectivity, and reproducibility. The collection and analysis of unsaturated carbonyls, and acrolein in particular, is complicated by unstable derivatives, coelution of similar compounds, and ozone interference. The primary objective of this research was to develop an analytical method to measure acrolein and other volatile carbonyls present in low part-per-trillion concentrations in ambient air samples obtained over short sampling periods. The method we devised uses a mist chamber in which carbonyls from air samples form water-soluble adducts with bisulfite in the chamber solution, effectively trapping the carbonyls in the solution. The mist chamber methodology proved effective, with collection efficiency for acrolein of at least 70% for each mist chamber at a flow rate of approximately 17 L/min. After the sample collection, the carbonyls are liberated from the bisulfite adducts through the addition of hydrogen peroxide, which converts the bisulfite to sulfate, reversing the bisulfite addition reaction. The free carbonyls are then derivatized by o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA*), which stabilizes the analytes and makes them easier to detect by electron-capture negative ionization mass spectrometry (ECNI-MS). The derivatives are then extracted and analyzed by gas chromatography-mass spectrometry (GC-MS). The mist chamber method was applied in a field test to determine the extent of acrolein in ambient air near the Peace Bridge plaza in Buffalo, New York, an area of heavy traffic near a major border crossing between the United States and Canada. In addition, XAD-2 adsorbent cartridges coated with 2-(hydroxymethyl)piperidine (2-HMP) according to Occupational Safety and Health Administration (OSHA) Method

  20. Impact of HVAC filter on indoor air quality in terms of ozone removal and carbonyls generation

    NASA Astrophysics Data System (ADS)

    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.

  1. Carbonyl compounds in the lower marine troposphere over the Caribbean Sea and Bahamas

    SciTech Connect

    Xianliang Zhou; Mopper, K. )

    1993-02-15

    Formaldehyde, acetaldehyde, acetone, and butanone were measured in 59 samples of marine air. Average clean air background concentrations were about 0.55, 0.50, 0.38, and 0.03 ppbv, respectively, in agreement with past measurements. The formaldehyde concentration is also in agreement with that predicted from photooxidation of methane and other locally derived organic matter. Formaldehyde and acetaldehyde showed strong diurnal variations throughout the 12-day sampling period. Photochemical oxidation of locally derived organic matter, such as nonmethane hydrocarbons and long-chained lipids, appears to be the major source for both formaldehyde and acetaldehyde in the lower marine boundary layer. Acetone, on the other hand, showed weaker diurnal fluctuations, consistent with its significantly longer lifetime in the trophosphere. Sinks for carbonyl compounds in the lower marine boundary layer are less clearly known. The results suggest that photolysis, reaction with free radicals, and deposition at the sea surface are minor, short-term sinks during the study. The main sink appears to be vertical mixing, probably followed by photolysis in the upper marine boundary layer and free troposphere. 34 refs., 6 figs., 2 tabs.

  2. The Development and Application of Two-Chamber Reactors and Carbon Monoxide Precursors for Safe Carbonylation Reactions.

    PubMed

    Friis, Stig D; Lindhardt, Anders T; Skrydstrup, Troels

    2016-04-19

    , an array of low-pressure carbonylations were developed applying only near stoichiometric amounts of carbon monoxide. Importantly, carbon isotope variants of the CO precursors, such as (13)COgen, Sila(13)COgen, or even (14)COgen, provide a simple means for performing isotope-labeling syntheses. Finally, the COware applicability has been extended to reactions with other gases, such as hydrogen, CO2, and ethylene including their deuterium and (13)C-isotopically labeled versions where relevant. The COware system has been repeatedly demonstrated to be a valuable reactor for carrying out a wide number of transition metal-catalyzed transformations, and we believe this technology will have a significant place in many organic research laboratories. PMID:26999377

  3. Photosynthetic Control of Atmospheric Carbonyl Sulfide during the Growing Season

    NASA Technical Reports Server (NTRS)

    Campbell, J. Elliott; Carmichael, Gregory R.; Chai, T.; Mena-Carrasco, M.; Tang, Y.; Blake, D. R.; Blake, N. J.; Vay, Stephanie A.; Collatz, G. James; Baker, I.; Berry, J. A.; Montzka, S. A.; Sweeney, C.; Schnoor, J. L.; Stanier, Charles O.

    2008-01-01

    Climate models incorporate photosynthesis-climate feedbacks, yet we lack robust tools for large-scale assessments of these processes. Recent work suggests that carbonyl sulfide (COS), a trace gas consumed by plants, could provide a valuable constraint on photosynthesis. Here we analyze airborne observations of COS and carbon dioxide concentrations during the growing season over North America with a three-dimensional atmospheric transport model. We successfully modeled the persistent vertical drawdown of atmospheric COS using the quantitative relation between COS and photosynthesis that has been measured in plant chamber experiments. Furthermore, this drawdown is driven by plant uptake rather than other continental and oceanic fluxes in the model. These results provide quantitative evidence that COS gradients in the continental growing season may have broad use as a measurement-based photosynthesis tracer.

  4. Magnetorheological Characterization of Organoclay Added Carbonyl-Iron Suspensions

    NASA Astrophysics Data System (ADS)

    Lim, S. T.; Cho, M. S.; Choi, H. J.; Jhon, M. S.

    Carbonyl-iron (CI) based magnetorheological (MR) fluid containing submicron-sized additive particles was prepared. The flow behavior at steady and oscillatory shear modes was investigated by comparing flow properties of CI-mineral oil suspensions without an additive via precise control of magnetic field strength. To enhance the dispersion stability and to examine submicron-sized filler effect for the CI suspensions, organically modified montmorillonite (organoclay) was added to the CI suspensions. In addition, with the precision control of magnetic field strength, we examined the novel features of submicron-sized particle filled CI suspensions, especially under weak magnetic field strengths, in steady shear modes; a temporal decrease of steady shear viscosity in sweeping magnetic field strengths was observed.

  5. Pt and Pt/(Cu) Carbonyl clusters synthesized by radiolysis

    NASA Astrophysics Data System (ADS)

    Le Gratiet, B.; Remita, H.; Picq, G.; Delcourt, M. O.

    1996-02-01

    In the mixed solvent: 50/50% v/v water/2-propanol, [Pt 3(CO) 6] n2- clusters with n = 3-10 have been obtained by irradiating solutions containing K 2PtCl 4 under 1 atm CO. n is deduced from the very typical UV-visible and IR absorption spectra. The reduction occurs by a combined effect of CO and of the radicals produced by radiolysis (radiocatalysis). The synthesis is selective: the nuclearity n can be chosen by adjusting the dose (high doses yield low n values). Increasing the Pt salt concentration leads to CO-stabilized subcolloid particles. Intermetallic cluster compounds are expected from solutions containing two metal salts: bimetallic Pt/Cu carbonyl clusters have been obtained. Two distinct compounds have been characterized by their UV-visible spectra. Attempts with Pt/Ru and Pt/Sn systems were unsuccessful.

  6. Gas-phase reactivity of ruthenium carbonyl cluster anions.

    PubMed

    Henderson, Matthew A; Kwok, Samantha; McIndoe, J Scott

    2009-04-01

    Partially-ligated anionic ruthenium carbonyl clusters react with alkenes, arenes, and alkanes in the gas phase; the products undergo extensive C-H activation and lose dihydrogen and carbon monoxide under collision-induced dissociation conditions. Triethylsilane and phenylsilane are also reactive towards the unsaturated clusters, and oxygen was shown to rapidly break down the cluster core by oxidative cleavage of the metal-metal bonds. These qualitative gas-phase reactivity studies were conducted using an easily-installed and inexpensive modification of a commercial electrospray ionization mass spectrometer. Interpretation of the large amounts of data generated in these studies is made relatively straightforward by employing energy-dependent electrospray ionization mass spectrometry (EDESI-MS). PMID:19185511

  7. Simultaneous determination of carbonyls and NO2 in exhausts of heavy-duty diesel trucks and transit buses by HPLC following 2,4-dinitrophenylhydrazine cartridge collection.

    PubMed

    Tang, Shida; Graham, Lisa; Shen, Ling; Zhou, Xianliang; Lanni, Thomas

    2004-11-15

    A method combining 2,4-dinitrophenylhydrazine (DNPH) cartridge sampling and high-performance liquid chromatography (HPLC) analysis has been used for the measurement of carbonyl and NO2 emissions from heavy-duty diesel trucks and transit buses. The reaction of NO2 with DNPH allows for the simultaneous and unambiguous determination of NO2 and carbonyl concentrations in exhaust samples. The potential coelution of the NO2-DNPH derivative with the formaldehyde-DNPH derivative under certain chromatographic conditions was investigated. Successful separation of these two species was achieved allowing for simultaneous determination of carbonyls and NO2 in the exhaust samples collected from heavy-duty diesel (HDD) trucks and diesel, diesel/electric hybrid, diesel equipped with the continuously regenerating technology (CRT) particle traps, and compressed natural gas (CNG) transit buses tested over various drive cycles. Elevated NO2 emissions from CRT-equipped buses were observed. The NO2/NOx volume ratios for HDD trucks and transit buses are discussed. A comparison of the DNPH derivatization with HPLC/UV-visible detection method with a chemiluminescence analyzer method for NO2 measurement is presented for a limited number of diesel/CRT and CNG buses. PMID:15573595

  8. Local Solvent Acidities in β-Cyclodextrin Complexes with PRODAN Derivatives

    PubMed Central

    Naughton, Hannah R.; Abelt, Christopher J.

    2013-01-01

    The local solvent acidities (SA scale) of six 6-carbonyl-2-aminonaphthalene derivatives as β-cyclodextrin complexes in water are determined through fluorescence quenching. The local polarities (ETN scale) are determined through the shift of the emission center-of-mass. The apparent SA values reflect the solvent structure surrounding the guest’s carbonyl group, whereas the apparent ETN values reveal the net polarity of the entire guest molecule. Comparison of these values affords greater insight into the structures of the host-guest complexes. Derivatives 1 and 5 show unusually large acidities indicative of highly exposed carbonyl groups. The remaining compounds give emission intensities pointing to shielded carbonyl groups. In this study PRODAN and its derivatives are functioning as dual channel sensors of their local environment. PMID:23473052

  9. Palladium-Catalyzed Carbonylative Cyclization of Arenes by C-H Bond Activation with DMF as the Carbonyl Source.

    PubMed

    Chen, Jianbin; Feng, Jian-Bo; Natte, Kishore; Wu, Xiao-Feng

    2015-11-01

    A novel palladium-catalyzed CO-gas- and autoclave-free protocol for the synthesis of 11H-pyrido[2,1-b]quinazolin-11-ones has been developed. Quinazolinones, which are omnipresent motif in many pharmaceuticals and agrochemicals, were prepared in good yields by C-H bond activation and annulation using DMF as the CO surrogate. A (13) CO-labelled DMF control experiment demonstrated that CO gas was released from the carbonyl of DMF with acid as the promotor. The kinetic isotope effect (KIE) value indicated that the C-H activation step may not be involved in the rate-determining step. This methodology is operationally simple and showed a broad substrate scope with good to excellent yields. PMID:26406903

  10. [Source emission characteristics of malodorous volatile organic carbonyls from a municipal sewage treatment plant].

    PubMed

    Zhou, Mi; Wang, Bo-Guang; Zhao, De-Jun; Zhang, Chun-Lin; Gu, Yin-Gang

    2011-12-01

    A 4-day field observation was conducted at Liede sewage treatment plant in Guangzhou, using PFPH/GC/MS method to analyse the composition and the concentration of volatile carbonyl compounds, and investigate the source emission characteristics of the pollutants. The results were as follows: 18 carbonyl species were detected, which including 15 malodorous volatile carbonyls with a concentration range from 0.39 microg x m(-3) to 19.92 microg x m(-3) at six processing units. Mean value of the total malodorous volatile carbonyls was (68.66 +/- 10.05) microg x m(-3). Normalization data process was used to research the source emission profile for malodorous volatile carbonyls, formaldehyde, acetaldehyde, propionaldehyde, 2-butanone, butyraldehyde and hexaldehyde were found to be molecular markers of the source emission with their percentage of total carbonyls up to 78.91%. Hexaldehyde was the most abundant carbonyl species with an average concentration of 11.71 microg x m(-3). Using a calculation model of area source emission, it estimated that the total annual emissions of the municipal sewage treatment plant was 2 302.33 kg(-1), and the contribution ratio of each processing unit was in an order of biochemical reaction basin, concentration basin, grade A aeration, ascending pump room, grit basin, dewatering house. The malodorous emission of sewage treatment plant is affected by many complex factors, so there's some uncertainty on the estimate. PMID:22468520

  11. Variation of ambient carbonyl levels in urban Beijing between 2005 and 2012

    NASA Astrophysics Data System (ADS)

    Chen, Wentai; Shao, Min; Wang, Ming; Lu, Sihua; Liu, Ying; Yuan, Bin; Yang, Yudong; Zeng, Limin; Chen, Zhongming; Chang, Chih-Chung; Zhang, Qian; Hu, Min

    2016-03-01

    Carbonyl compounds are important precursors of secondary air pollutants. With the rapid economic development and the implementation of stricter control measures in Beijing, the sources of carbonyls possibly changed. Based on measurement data obtained at an urban site in Beijing between 2005 and 2012, we investigated annual variations in carbonyl levels and sources during these years. In summer, formaldehyde and acetaldehyde levels decreased significantly at a rate of 9.1%/year and 7.2%/year, respectively, while acetone levels increased at a rate of 4.3%/year. In winter, formaldehyde levels increased and acetaldehyde levels decreased. We also investigated the factors driving the variation in carbonyls levels during summer by determination of emission ratios for carbonyls and their precursors, and calculation of photochemical formation of carbonyls. The relative declines for primary formaldehyde and acetaldehyde levels were larger than those for secondary formation. This is possibly due to the increasing usage of natural gas and liquefied petroleum gas which could result in the rise of carbonyl precursor emission ratios. The increase in acetone levels might be related to the rising solvent usage in Beijing during these years. The influences of these sources should be paid more attention in future research.

  12. Electroless plating preparation and electromagnetic properties of Co-coated carbonyl iron particles/polyimide composite

    NASA Astrophysics Data System (ADS)

    Zhou, Yingying; Zhou, Wancheng; Li, Rong; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2016-03-01

    To solve the serious electromagnetic interference problems at elevated temperature, one thin microwave-absorbing sheet employing Co-coated carbonyl iron particles and polyimide was prepared. The Co-coated carbonyl iron particles were successfully prepared using an electroless plating method. The microstructure, composition, phase and static magnetic properties of Co-coated carbonyl iron particles were characterized by combination of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The electromagnetic parameters of Co-coated carbonyl iron particles/polyimide composite were measured in the frequency range of 2-18 GHz, and the electromagnetic loss mechanism of the material-obtained was discussed. The microwave absorption properties of composites before and after heat treatment at 300 °C for 100 h were characterized in 2-18 GHz frequency range. It was established that composites based on Co-coated carbonyl iron demonstrate thermomagnetic stability, indicating that Co coating reduces the oxidation of carbonyl iron. Thus, Co-coated carbonyl iron particles/polyimide composites are useful in the design of microwave absorbers operating at temperatures up to 300 °C.

  13. Dissociative electron attachment reactions of transition metal carbonyls and their apparent influence on the thermalization of electrons by CO2

    NASA Astrophysics Data System (ADS)

    George, Patricia M.; Beauchamp, J. L.

    1982-03-01

    Dissociative electron attachment rates are measured for the transition metal carbonyls V(CO)6, Cr(CO)6, Fe(CO)5, Ni(CO)4, Mo(CO)6, and W(CO)6. Rates are measured as a function of the pressure of CO2 added to relax epithermal electrons. Derived thermal rate constants for the formation of M(CO)-n-1 from M(CO)n are 0.6, 3.0, 2.0, 2.0, 1.3, and 1.2×10-7 cm3 molecule-1 s-1, respectively. The differences in these rate constants may be attributed to the different stabilities of the molecular anion with regard to dissociation versus autodetachment. The measured rate of thermalization of electrons by CO2 varies with the metal carbonyl used and depends on the variation of the dissociative electron capture cross section with electron energy. Each system is thus tightly coupled in that the electron energy distribution is determined not only by collisional processes involving CO2 but varies as well with the energy dependent depletion of the distribution by reactant species.

  14. Characteristics of carbonyls: Concentrations and source strengths for indoor and outdoor residential microenvironments in China

    NASA Astrophysics Data System (ADS)

    Wang, B.; Lee, S. C.; Ho, K. F.

    Indoor and outdoor carbonyl concentrations were measured simultaneously in 12 urban dwellings in Beijing, Shanghai, Guangzhou, and Xi'an, China in summer (from July to September in 2004) and winter (from December 2004 to February 2005). Formaldehyde was the most abundant indoor carbonyls species, while formaldehyde, acetaldehyde and acetone were found to be the most abundant outdoor carbonyls species. The average formaldehyde concentrations in summer indoor air varied widely between cities, ranging from a low of 19.3 μg m -3 in Xi'an to a high of 92.8 μg m -3 in Beijing. The results showed that the dwellings with tobacco smoke, incense burning or poor ventilation had significantly higher indoor concentrations of certain carbonyls. It was noticed that although one half of the dwellings in this study installed with low emission building materials or furniture, the carbonyls levels were still significantly high. It was also noted that in winter both the indoor and outdoor acetone concentrations in two dwellings in Guangzhou were significantly high, which were mainly caused by the usage of acetone as industrial solvent in many paint manufacturing and other industries located around Guangzhou and relatively longer lifetime of acetone for removal by photolysis and OH reaction than other carbonyls species. The indoor carbonyls levels in Chinese dwellings were higher than that in dwellings in the other countries. The levels of indoor and ambient carbonyls showed great seasonal differences. Six carbonyls species were carried out the estimation of indoor source strengths. Formaldehyde had the largest indoor source strength, with an average of 5.25 mg h -1 in summer and 1.98 mg h -1 in winter, respectively. However, propionaldehyde, crotonaldehyde and benzaldehyde had the weakest indoor sources.

  15. Extraction of dielectric and magnetic properties of carbonyl iron powder composites at high frequencies

    NASA Astrophysics Data System (ADS)

    Zivkovic, I.; Murk, A.

    2012-06-01

    In this paper, we examine carbonyl iron composites in silicone rubber and epoxy matrices. Transmission measurements were performed at W (70 to 110 GHz) and Ka (26 to 40 GHz) bands and effective permittivity and permeability of composites with 10% volume fraction of carbonyl iron powder (CIP) were extracted at these frequencies. To extract permittivity and permeability of carbonyl iron powder in W and Ka bands, we use Looyenga formula. We extract permittivity and permeability of CIP from both silicone rubber and epoxy based composites and good agreement is achieved.

  16. A Convenient Palladium-Catalyzed Reductive Carbonylation of Aryl Iodides with Dual Role of Formic Acid.

    PubMed

    Qi, Xinxin; Li, Chong-Liang; Wu, Xiao-Feng

    2016-04-18

    Palladium-catalyzed reductive carbonylation of aryl halides represents a straightforward pathway for the synthesis of aromatic aldehydes. The known reductive carbonylation procedures either require CO gas or complexed compounds as CO sources. In this communication, we developed a palladium-catalyzed reductive carbonylation of aryl iodides with formic acid as the formyl source. As a convenient, practical, and environmental friendly methodology, no additional silane or H2 was required. A variety of aromatic aldehydes were isolated in moderate to excellent yields under mild reaction conditions. Notably, this is the first procedure on using formic acid as the formyl source. PMID:26934464

  17. One-pot aldol condensation and hydrodeoxygenation of biomass-derived carbonyl compounds for biodiesel synthesis.

    PubMed

    Faba, Laura; Díaz, Eva; Ordóñez, Salvador

    2014-10-01

    Integrating reaction steps is of key interest in the development of processes for transforming lignocellulosic materials into drop-in fuels. We propose a procedure for performing the aldol condensation (reaction between furfural and acetone is taken as model reaction) and the total hydrodeoxygenation of the resulting condensation adducts in one step, yielding n-alkanes. Different combinations of catalysts (bifunctional catalysts or mechanical mixtures), reaction conditions, and solvents (aqueous and organic) have been tested for performing these reactions in an isothermal batch reactor. The results suggest that the use of bifunctional catalysts and aqueous phase lead to an effective integration of both reactions. Therefore, selectivities to n-alkanes higher than 50% were obtained using this catalyst at typical hydrogenation conditions (T=493 K, P=4.5 MPa, 24 h reaction time). The use of organic solvent, carbonaceous supports, or mechanical mixtures of monofunctional catalysts leads to poorer results owing to side effects; mainly, hydrogenation of reactants and adsorption processes. PMID:25088473

  18. Enantioselective Palladium-Catalyzed Oxidative β,β-Fluoroarylation of α,β-Unsaturated Carbonyl Derivatives.

    PubMed

    Miró, Javier; Del Pozo, Carlos; Toste, F Dean; Fustero, Santos

    2016-07-25

    The site-selective palladium-catalyzed three-component coupling of deactivated alkenes, arylboronic acids, and N-fluorobenzenesulfonimide is disclosed herein. The developed methodology establishes a general, modular, and step-economical approach to the stereoselective β-fluorination of α,β-unsaturated systems. PMID:27272390

  19. Efficient synthesis of ureas by direct palladium-catalyzed oxidative carbonylation of amines.

    PubMed

    Gabriele, Bartolo; Salerno, Giuseppe; Mancuso, Raffaella; Costa, Mirco

    2004-07-01

    A general synthesis of symmetrically disubstituted ureas and trisubstituted ureas by direct Pd-catalyzed oxidative carbonylation of primary amines or of a mixture of a primary and a secondary amine, respectively, with unprecedented catalytic efficiencies for this kind of process, is reported. Reactions are carried out at 90-100 degrees C in DME as the solvent in the presence of PdI(2) in conjunction with an excess of KI as the catalytic system and under 20 atm of a 4:1 mixture of CO and air. In some cases, working in the presence of an excess of CO(2) (40 atm) in addition to CO and air (60 atm total) had a beneficial effect on substrate reactivity and product yield. Cyclic five-membered and six-membered ureas were easily formed from primary diamines. The methodology has been successfully applied to the synthesis of pharmacologically active ureas, such as those deriving from alpha-amino esters or urea NPY5RA-972, a potent antagonist of the neuropeptide Y5 receptor. PMID:15230597

  20. Effect of HPLC binary mobile phase composition on the analysis of carbonyls.

    PubMed

    Ho, Duy Xuan; Kim, Ki-Hyun

    2011-09-01

    The relative performance of the binary mobile phase in the high-performance liquid chromatography analysis of carbonyl compounds (CCs) was tested using the liquid-phase standards containing 15 aldehyde/ketone-DNPH mixture. The Hichrome column was employed for the analysis of CCs at a flow rate of 1.5 mL min( - 1). The binary mobile phases prepared using both acetonitrile/water (AW) and a possible alternative of methanol:water (MW) mixture were examined by their calibration results. The data derived from these two binary phases were then evaluated in terms of three key variables (i.e., resolution, relative sensitivity, and retention time). The relative water content (or the water to organic solvent ratio (W/A) or (W/M)) of the binary phase was found as the key variable for the performance. The results indicate that the optimal resolution of AW combination was attained consistently for most composition, while MW generally suffered from overpressure problem. The changes of water content in the AW mixture led to the changes of all three variables in the quantitative analysis of CCs. The obtained results confirm that the AW mixture should be the optimal elutant for the CC analysis, as other simple binary compositions like MW are limited in many respects. PMID:21107904

  1. An oxidoreductase from 'Alphonso' mango catalyzing biosynthesis of furaneol and reduction of reactive carbonyls.

    PubMed

    Kulkarni, Ram; Chidley, Hemangi; Deshpande, Ashish; Schmidt, Axel; Pujari, Keshav; Giri, Ashok; Gershenzon, Jonathan; Gupta, Vidya

    2013-01-01

    Two furanones, furaneol (4-hydroxy-2,5-dimethyl-3(2H)-furanone) and mesifuran (2,5-dimethyl-4-methoxy-3(2H)-furanone), are important constituents of flavor of the Alphonso cultivar of mango (Mangifera indica). To get insights into the biosynthesis of these furanones, we isolated an enone oxidoreductase gene from the Alphonso mango. It has high sequence similarity to an alkenal/one oxidoreductase from cucumber (79% identity) and enone oxidoreductases from tomato (73% identity) and strawberry (72% identity). The complete open reading frame was expressed in E. coli and the (his)6-tagged recombinant protein was purified by affinity chromatography. The purified protein assayed with NADH as a reducing agent converted D-fructose-1,6-diphosphate into furaneol, the immediate precursor of mesifuran. The enzyme was also able to convert two highly reactive carbonyls, 3-buten-2-one and 1-penten-3-one, produced by lipid peroxidation in plants, into their saturated derivatives. Expression profiling in various ripening stages of Alphonso fruits depicted an expression maxima at 10 days after harvest stage, shortly before the appearance of the maximum amount of furanones (completely ripe stage, 15 days after harvest). Although no furanones were detected at the 0 day after harvest stage, significant expression of this gene was detected in the fruits at this stage. Overall, the results suggest that this oxidoreductase plays important roles in Alphonso mango fruits. PMID:24133645

  2. Radical-mediated dehydrogenation of bile acids by means of hydrogen atom transfer to triplet carbonyls.

    PubMed

    Miro, P; Marin, M L; Miranda, M A

    2016-03-01

    The aim of the present paper is to explore the potential of radical-mediated dehydrogenation of bile salts (BSs), which is reminiscent of the enzymatic action of hydroxysteroid dehydrogenase enzymes (HSDH). The concept has been demonstrated using triplet carbonyls that can be efficiently generated upon selective UVA-excitation. Hydrogen atom transfer (HAT) from BSs to triplet benzophenone (BP) derivatives gave rise to radicals, ultimately leading to reduction of the BP chromophore with concomitant formation of the oxo-analogs of the corresponding BSs. The direct reactivity of triplet BP with BSs in the initial step was evaluated by determining the kinetic rate constants using laser flash photolysis (LFP). The BP triplet decay was monitored (λmax = 520 nm) upon addition of increasing BS concentrations, and the obtained rate constant values indicated a reactivity of the methine hydrogen atoms in the order of C-3 < C-12 < C-7. The steady-state kinetics of the overall process, monitored through the disappearance of the typical BP absorption band at 260 nm, was much faster under N2 than under O2, also supporting the role of the oxygen-quenchable triplet in the dehydrogenation process. Furthermore, irradiation of deaerated aqueous solutions of sodium cholate in the presence of KPMe provided the oxo-analogs, 3[O],7[O]-CA, 3[O]-CA and 7[O]-CA, arising from the HAT process. PMID:26833240

  3. Carbonyl compounds over urban Beijing: Concentrations on haze and non-haze days and effects on radical chemistry

    NASA Astrophysics Data System (ADS)

    Rao, Zhihan; Chen, Zhongming; Liang, Hao; Huang, Liubin; Huang, Dao

    2016-01-01

    Carbonyl compounds play an important role in the formation of secondary aerosols and the cycling of free radicals in the atmosphere. We measured carbonyl compounds over urban Beijing, a megacity in the North China Plain, in summer and winter to investigate the relation of carbonyl compounds with haze and the interaction between carbonyl compounds and atmospheric radical cycling. We also determined carbonyl compounds in summer rainwater. Data of carbonyl compounds were analyzed in four cases, i.e., summer haze days (SHD), summer non-haze days (SND), winter haze days (WHD), and winter non-haze days (WND). Interestingly, the level of carbonyl compounds during WHD approached that of summer days. The results of the principal component analysis showed that there was no obvious source difference between SHD and SND. On WHD, however, more carbonyl compounds originated from the "diesel engine exhaust emission" than those on WND. We evaluated the effect of carbonyl compounds on the free radical cycling and the NO consumption potential for OH formation in the photochemical reactions using a novel ratio method. It was found that the production rate of ROx (the sum of OH, HO2 and RO2 radicals) was highest on SND, while the yield of ROx radicals from the reactions of carbonyl compounds was highest on WHD. Further, carbonyl compounds consumed more NO to produce OH radicals on WHD compared to the other three cases.

  4. Free tropospheric observations of Carbonyl Sulfide from Aura Tropospheric Emission Spectrometer over ocean

    NASA Astrophysics Data System (ADS)

    Kuai, Le; Worden, John; Campbell, Ellitt; Kulawik, Susan; Montzka, Stephen; Liu, Jiabin

    2014-05-01

    Carbonyl sulfide (OCS) is the most abundant sulfur gas in the troposphere with a global averaging mixing ratio of about 500 part per trillion (ppt). The ocean is the primary source of OCS, emitting OCS directly or its precursors, carbon disulfide and dimethyl sulfide. The most important atmospheric sink of OCS is uptake by terrestrial plants via photosynthesis. Although the global budget of atmospheric OCS has been studied, the global integrated OCS fluxes have large uncertainties, e.g. the uncertainties of the ocean fluxes are as large as 100% or more and how the ocean sources are distributed is not well known. We developed a retrieval algorithm for free tropospheric carbonyl sulfide (OCS) observations above the ocean using radiance measurements from the Tropospheric Emission Spectrometer (TES). These first observations of the free tropospheric OCS provide global maps with information of OCS seasonal and spatial variability in the mid troposphere. These data will help to characterize ocean OCS fluxes. Evaluation of the biases and uncertainties in the TES OCS estimates against aircraft profiles from the HIPPO campaign and ground data from the NOAA Mauna Loa site suggests that the OCS retrievals (1) have less than 1.0 degree of freedom for signals (DOFs), (2) are sensitive in the mid-troposphere with a peak sensitivity typically between 300 to 500 hPa, (3) and have much smaller systematic errors from temperature, CO2 and H2O calibrations relative to random errors from measurement noise. Here we estimate the monthly means from TES measurements averaged over multiple years so that random errors are reduced and useful information about OCS seasonal and latitudinal variability can be derived. With this averaging, TES OCS data are found to be consistent (within the calculated uncertainties) with NOAA ground observations and HIPPO aircraft measurements and captures the seasonal and latitudinal variations observed by these in situ data within the estimated uncertainties

  5. Atmospheric Sulfur Cycle Effects of Carbonyl Sulfide (OCS)

    NASA Technical Reports Server (NTRS)

    McBee, Joshua

    1996-01-01

    Carbonyl Sulfide(OCS) is considered to be one of the major sources of sulfur appearing in the stratosphere due to its relative inertness, about I to 10 yearsl. However, the roles of OCS as well as other reduced sulfur compounds such as carbon disulfide (CS2), hydrogen sulfide (H2S), and dimethyl disulfide(CH3)2S2, are not completely understood in the atmosphenc sulfur cycle. Consequently vely little information is available about the effect of sulfur compounds in the stratosphere. The ability of OCS to penetrate into the stratosphere makes it an excellent tracer for study of the role of the sulfi r cycle in stratospheric chemistry. Previously techniques such as gas chromatography and whole air sampling have been used to measure OCS analytically. Each technique had its drawbacks however, with both being quite slow, and whole air sampling being somewhat unreliable. With molecular spectroscopy, however, it has been found in recent years that the tunable diode laser absorption spectrometer (TDL) provides a very rapid and accurate method of measuring OCS and other trace gases

  6. Thermal characterization of magnetically aligned carbonyl iron/agar composites.

    PubMed

    Diaz-Bleis, D; Vales-Pinzón, C; Freile-Pelegrín, Y; Alvarado-Gil, J J

    2014-01-01

    Composites of magnetic particles into polymeric matrices have received increasing research interest due to their capacity to respond to external magnetic or electromagnetic fields. In this study, agar from Gelidium robustum has been chosen as natural biocompatible polymer to build the matrix of the magnetic carbonyl iron particles (CIP) for their uses in biomedical fields. Heat transfer behavior of the CIP-agar composites containing different concentrations (5, 10, 15, 20, 25 and 30% w/w) of magnetically aligned and non-aligned CIP in the agar matrix was studied using photothermal radiometry (PTR) in the back-propagation emission configuration. The morphology of the CIP-agar composites with aligned and non-aligned CIP under magnetic field was also evaluated by scanning electron microscopy (SEM). The results revealed a dominant effect of CIP concentration over the alignment patterns induced by the magnetic field, which agrees with the behavior of the thermal diffusivity and thermal conductivity. Agar served as a perfect matrix to be used with CIP, and CIP-agar composites magnetically aligned at 20% CIP concentration can be considered as promising 'smart' material for hyperthermia treatments in the biomedical field. PMID:24274482

  7. Hydroxyl radical substitution in halogenated carbonyls: oxalic acid formation.

    PubMed

    Christiansen, Carrie J; Dalal, Shakeel S; Francisco, Joseph S; Mebel, Alexander M; Gaffney, Jeffrey S

    2010-03-01

    An ab initio study of OH radical substitution reactions in halogenated carbonyls is conducted. Hydroxyl radical substitution into oxalyl dichloride [ClC(O)C(O)Cl] and oxalyl dibromide [BrC(O)C(O)Br], resulting in the formation of oxalic acid, is presented. Analogous substitution reactions in formyl chloride [ClCH(O)], acetyl chloride [ClC(O)CH(3)], formyl bromide [BrCH(O)], and acetyl bromide [BrC(O)CH(3)] are considered. Energetics of competing hydrogen abstraction reactions for all applicable species are computed for comparison. Geometry optimizations and frequency computations are performed using the second-order Møller-Plesset perturbation theory (MP2) and the 6-31G(d) basis set for all minimum species and transition states. Single point energy computations are performed using fourth-order Møller-Plesset perturbation theory (MP4) and coupled cluster theory [CCSD(T)]. Potential energy surfaces, including activation energies and enthalpies, are determined from the computations. These potential energy surfaces show that OH substitution into ClC(O)C(O)Cl and BrC(O)C(O)Br, resulting in the formation of oxalic acid and other minor products, is energetically favorable. Energetics of analogous reactions with ClCH(O), BrCH(O), ClC(O)CH(3), and BrC(O)CH(3) are also computed. PMID:20131850

  8. Seasonal fluxes of carbonyl sulfide in a midlatitude forest

    NASA Astrophysics Data System (ADS)

    Commane, Róisín; Meredith, Laura K.; Baker, Ian T.; Berry, Joseph A.; Munger, J. William; Montzka, Stephen A.; Templer, Pamela H.; Juice, Stephanie M.; Zahniser, Mark S.; Wofsy, Steven C.

    2015-11-01

    Carbonyl sulfide (OCS), the most abundant sulfur gas in the atmosphere, has a summer minimum associated with uptake by vegetation and soils, closely correlated with CO2. We report the first direct measurements to our knowledge of the ecosystem flux of OCS throughout an annual cycle, at a mixed temperate forest. The forest took up OCS during most of the growing season with an overall uptake of 1.36 ± 0.01 mol OCS per ha (43.5 ± 0.5 g S per ha, 95% confidence intervals) for the year. Daytime fluxes accounted for 72% of total uptake. Both soils and incompletely closed stomata in the canopy contributed to nighttime fluxes. Unexpected net OCS emission occurred during the warmest weeks in summer. Many requirements necessary to use fluxes of OCS as a simple estimate of photosynthesis were not met because OCS fluxes did not have a constant relationship with photosynthesis throughout an entire day or over the entire year. However, OCS fluxes provide a direct measure of ecosystem-scale stomatal conductance and mesophyll function, without relying on measures of soil evaporation or leaf temperature, and reveal previously unseen heterogeneity of forest canopy processes. Observations of OCS flux provide powerful, independent means to test and refine land surface and carbon cycle models at the ecosystem scale.

  9. Seasonal fluxes of carbonyl sulfide in a midlatitude forest.

    PubMed

    Commane, Róisín; Meredith, Laura K; Baker, Ian T; Berry, Joseph A; Munger, J William; Montzka, Stephen A; Templer, Pamela H; Juice, Stephanie M; Zahniser, Mark S; Wofsy, Steven C

    2015-11-17

    Carbonyl sulfide (OCS), the most abundant sulfur gas in the atmosphere, has a summer minimum associated with uptake by vegetation and soils, closely correlated with CO2. We report the first direct measurements to our knowledge of the ecosystem flux of OCS throughout an annual cycle, at a mixed temperate forest. The forest took up OCS during most of the growing season with an overall uptake of 1.36 ± 0.01 mol OCS per ha (43.5 ± 0.5 g S per ha, 95% confidence intervals) for the year. Daytime fluxes accounted for 72% of total uptake. Both soils and incompletely closed stomata in the canopy contributed to nighttime fluxes. Unexpected net OCS emission occurred during the warmest weeks in summer. Many requirements necessary to use fluxes of OCS as a simple estimate of photosynthesis were not met because OCS fluxes did not have a constant relationship with photosynthesis throughout an entire day or over the entire year. However, OCS fluxes provide a direct measure of ecosystem-scale stomatal conductance and mesophyll function, without relying on measures of soil evaporation or leaf temperature, and reveal previously unseen heterogeneity of forest canopy processes. Observations of OCS flux provide powerful, independent means to test and refine land surface and carbon cycle models at the ecosystem scale. PMID:26578759

  10. Magnetorheological characteristics of carbon nanotube wrapped carbonyl iron particles

    NASA Astrophysics Data System (ADS)

    Fang, Fei Fei; Choi, Byung Il; Choi, Hyoung Jin

    2009-02-01

    Carbonyl iron (CI) based magnetorheological (MR) fluid exhibits serious dispersion defect in general due to large density mismatch between CI particles and continuous medium, which restricts further MR application. Thus, various strategies were explored either to reduce the density or to prevent CI particle aggregation. Among them, polymer coating technology becomes more prevalent due to favorable morphology obtained and effective decrease in density by introducing polymeric shell; nevertheless, coating polymer on the surface of CI particles is always influenced by the selected grafting agent, mole ratio of reactant or the temperature of reaction. In this work, considering self-assembling trend of carbon nanotube (CNT) which exhibits similar density with polymer but better magnetic property due to the iron catalyst, we constructed a dense nest composed of CNT on the surface of CI particles by using 4-aminobenzoic acid (PABA) as a grafting agent under sonication. Thickness and morphology of the CNT nest were found to be related with sonication duration via SEM/TEM images. MR performances (yield stress behavior, shear viscosity) of the CI/CNT particles based MR fluid were investigated via controlled shear rate and controlled shear stress methods. Finally, sedimentation observation was checked to be improved.

  11. Behaviour of protein carbonyl groups in juvenile myocardial infarction.

    PubMed

    Caimi, Gregorio; Canino, Baldassare; Incalcaterra, Egle; Ferrera, Eleonora; Montana, Maria; Lo Presti, Rosalia

    2013-01-01

    Acute myocardial infarction (AMI) is accompanied by oxidative stress, and protein oxidation is among the consequences of oxidative stress. We examined the plasma concentration of protein carbonyl groups (PC), a marker of protein oxidation, in a group of young subjects with AMI (45 men and 5 women; mean age 40.4 ± 4.8 yrs). We found a significant increase of PC (p < 0.001) in comparison with normal controls. No difference was observed between patients with AMI characterized by elevated ST segment and those without elevation of ST segment. There was no correlation between the ejection fraction and PC in the whole group nor in the subgroups of STEMI and non-STEMI patients. Subdividing the whole group of AMI patients according to the number of risk factors and the number of stenosed coronary vessels, the difference in PC level was not statistically significant among the subgroups. This study showed an increased protein oxidation in young subjects with recent AMI. Further investigation is needed to ascertain whether this can be a target of therapeutic intervention. PMID:22504219

  12. Tropical sources and sinks of carbonyl sulfide observed from space

    NASA Astrophysics Data System (ADS)

    Glatthor, N.; Höpfner, M.; Baker, I. T.; Berry, J.; Campbell, J. E.; Kawa, S. R.; Krysztofiak, G.; Leyser, A.; Sinnhuber, B.-M.; Stiller, G. P.; Stinecipher, J.; Clarmann, T.

    2015-11-01

    According to current budget estimations the seasonal variation of carbonyl sulfide (COS) is governed by oceanic release and vegetation uptake. Its assimilation by plants is assumed to be similar to the photosynthetic uptake of CO2 but, contrary to the latter process, to be irreversible. Therefore, COS has been suggested as cotracer of the carbon cycle. Observations of COS, however, are sparse, especially in tropical regions. We use the comprehensive data set of spaceborne measurements of the Michelson Interferometer for Passive Atmospheric Sounding to analyze its global distribution. Two major features are observed in the tropical upper troposphere around 250 hPa: enhanced amounts over the western Pacific and the Maritime Continent, peaking around 550 parts per trillion by volume (pptv) in boreal summer, and a seasonally varying depletion of COS extending from tropical South America to Africa. The large-scale COS depletion, which in austral summer amounts up to -40 pptv as compared to the rest of the respective latitude band, has not been observed before and reveals the seasonality of COS uptake through tropical vegetation. The observations can only be reproduced by global models, when a large vegetation uptake and a corresponding increase in oceanic emissions as proposed in several recent publications are assumed.

  13. Seasonal fluxes of carbonyl sulfide in a midlatitude forest

    PubMed Central

    Commane, Róisín; Meredith, Laura K.; Baker, Ian T.; Berry, Joseph A.; Munger, J. William; Montzka, Stephen A.; Templer, Pamela H.; Juice, Stephanie M.; Zahniser, Mark S.; Wofsy, Steven C.

    2015-01-01

    Carbonyl sulfide (OCS), the most abundant sulfur gas in the atmosphere, has a summer minimum associated with uptake by vegetation and soils, closely correlated with CO2. We report the first direct measurements to our knowledge of the ecosystem flux of OCS throughout an annual cycle, at a mixed temperate forest. The forest took up OCS during most of the growing season with an overall uptake of 1.36 ± 0.01 mol OCS per ha (43.5 ± 0.5 g S per ha, 95% confidence intervals) for the year. Daytime fluxes accounted for 72% of total uptake. Both soils and incompletely closed stomata in the canopy contributed to nighttime fluxes. Unexpected net OCS emission occurred during the warmest weeks in summer. Many requirements necessary to use fluxes of OCS as a simple estimate of photosynthesis were not met because OCS fluxes did not have a constant relationship with photosynthesis throughout an entire day or over the entire year. However, OCS fluxes provide a direct measure of ecosystem-scale stomatal conductance and mesophyll function, without relying on measures of soil evaporation or leaf temperature, and reveal previously unseen heterogeneity of forest canopy processes. Observations of OCS flux provide powerful, independent means to test and refine land surface and carbon cycle models at the ecosystem scale. PMID:26578759

  14. The oceanic cycle and global atmospheric budget of carbonyl sulfide

    SciTech Connect

    Weiss, P.S.

    1994-12-31

    A significant portion of stratospheric air chemistry is influenced by the existence of carbonyl sulfide (COS). This ubiquitous sulfur gas represents a major source of sulfur to the stratosphere where it is converted to sulfuric acid aerosol particles. Stratospheric aerosols are climatically important because they scatter incoming solar radiation back to space and are able to increase the catalytic destruction of ozone through gas phase reactions on particle surfaces. COS is primarily formed at the surface of the earth, in both marine and terrestrial environments, and is strongly linked to natural biological processes. However, many gaps in the understanding of the global COS cycle still exist, which has led to a global atmospheric budget that is out of balance by a factor of two or more, and a lack of understanding of how human activity has affected the cycling of this gas. The goal of this study was to focus on COS in the marine environment by investigating production/destruction mechanisms and recalculating the ocean-atmosphere flux.

  15. Teratogenicity and embryotoxicity of nickel carbonyl in Syrian hamsters

    SciTech Connect

    Sunderman, F.W. Jr.; Shen, S.K.; Reid, M.C.; Allpass, P.R.

    1980-01-01

    Nickel carbonyl was administered to groups of pregnant hamsters by inhalation on days 4, 5, 6, 7, or 8 of gestation. The dams were killed on day 15 of gestation, and the fetuses were examined for malformations. Exposure to Ni(CO)/sub 4/ on days 4 or 5 of gestation resulted in malformation in 5.5% and 5.8% of the progeny, respectively. Progeny included 9 fetuses with cystic lungs, 7 fetuses with exencephaly, 1 fetus with exencephaly plus fused rib and 1 fetus with anophthalmia plus cleft palate. Hemorrhages into serious cavities were found. In progeny of dams exposed to Ni(CO)/sub 4/ on days 6 or 7 of gestation, there was 1 fetus with fused ribs and there were 2 fetuses with hydronephrosis. In another experiment, pregnant hamsters were exposed to inhalation of Ni(CO)/sub 4/ on day 5 of gestation; these dams were permitted to deliver their litters and to nurse their pups. There was no significant difference in the average number of live pups in the Ni(CO)/sub 4/-exposed litters compared to control litters. Neonatal mortality was increased in Ni(CO)/sub 4/-exposed litters. This study demonstrates that Ni(CO)/sub 4/ is teratogenic and embryotoxic in Syrian hamsters.

  16. The effect of N-stearoylethanolamine on cholesterol content, fatty acid composition and protein carbonylation level in rats with alimentary obesity-induced insulin resistance.

    PubMed

    Onopchenko, O V; Kosiakova, G V; Meged, E F; Klimashevsky, V M; Hula, N M

    2014-01-01

    The effect of N-stearoylethanolamine (NSE) on liver free fatty acid composition, cholesterol content and carbonylated protein level in rats with obesity-induced insulin resistance (IR) was studied in the work. The experimental insulin resistance was induced by prolonged high fat diet (58% of energy derived from fat) for 6 months combined with one injection of low-dose (15 mg/kg) of streptozotocin. The lipid assay showed a rise in liver free cholesterol content anda significant reduction in cholesterol esters level. Analyzing liver fatty acid composition, a decrease in polyunsaturated of fatty acid (PUFA) level and an increase in monounsaturated fatty acid (MUFA) content was found. Fatty acid imbalance with high content of MUFA was associated with elevated level ofprotein carbonylation. The NSE administration (50 mg/kg of body weight) for 2 weeks decreased free cholesterol content, increased cholesterol esters level and reduced free oleic fatty acid content in the liver of rats with IR. The effect of NSE on lipid imbalance led to a decrease in protein carbonylation level that may result in improvement of transmembrane protein function under obesity-induced insulin resistance state. PMID:25816612

  17. Spectroscopic line parameters for the nu6 band of carbonyl fluoride

    NASA Technical Reports Server (NTRS)

    Goldman, Aaron; Blatherwick, Ronald D.; Bonomo, Francis S.; Rinsland, Curtis P.

    1990-01-01

    New measurements and analysis of high-resolution (0.0025/cm) laboratory spectra of the carbonyl fluoride nu6 band are described. The data are used to generate line parameters suitable for high-resolution atmospheric studies.

  18. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, Ronald

    1985-01-01

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  19. Gas-aerosol partitioning of semi volatile carbonyls in polluted atmosphere in Hachioji, Tokyo

    NASA Astrophysics Data System (ADS)

    Matsunaga, Sou N.; Kato, Shungo; Yoshino, Ayako; Greenberg, Jim P.; Kajii, Yoshizumi; Guenther, Alex B.

    2005-06-01

    Gaseous and particulate semi volatile carbonyls have been measured in urban air using an annular denuder sampling system. Three dicarbonyls, five aliphatic aldehydes and two hydroxy carbonyls were observed. Concentrations of other biogenic and anthropogenic volatile organic compounds (VOCs), SO2, CO, NO2 and particle concentration were also measured. Estimated gas-aerosol equilibrium constants for the carbonyls showed an inverse correlation with the concentrations of anthropogenic pollutants such as benzene, isopentane and SO2. This suggests that the increase in the fraction of non-polar anthropogenic particles in the atmosphere could change the average property of the ambient aerosols and drive the gas particle equilibrium of the carbonyls to the gas phase. This trend is uncommon in remote forest air. In this study, we examined the factors controlling the equilibrium in the polluted atmosphere and show that there is a difference in gas-aerosol partition between polluted and clean air.

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

    NASA Astrophysics Data System (ADS)

    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).

  1. Reaction or organomagnesium compounds of the adamantane series with carbonyl compounds

    SciTech Connect

    Yurchenko, A.G.; Fedorenko, T.V.

    1987-10-10

    In the transformations of organomagnesium compounds of the adamantane series involving aldehydes, ketones, esters, and acid chlorides the nature of the reaction products and their yields are determined by the steric hindrances at the reaction centers of the organomagnesium and carbonyl compounds and by the ease of homolysis of the C-H bonds of the carbonyl reagent. The retardation of the faster addition of the Grignard reagent at the carbonyl group as a result of steric hindrances permits homolytic removal of a hydrogen atom from the carbonyl compound by the adamantyl radical. The PMR spectra were measured on a Tesla BS-487C spectrometer at 80 MHz in carbon tetrachloride with the substances at concentrations of 5-20% and with TMS as internal standard. The IR spectra were obtained in carbon tetrachloride on a UR-10 spectrophotometer.

  2. Ruthenium carbonyl catalyst supported on ceric oxide for preparation of olefins from synthesis gas

    DOEpatents

    Pierantozzi, R.

    1985-04-02

    A catalyst comprising a ruthenium carbonyl compound deposited on a cerium oxide-containing support material provides for the selective synthesis of low molecular weight olefinic hydrocarbons from mixtures of hydrogen and carbon monoxide.

  3. A carbonyl iron/carbon fiber material for electromagnetic wave absorption.

    PubMed

    Youh, Meng-Jey; Wu, Hung-Chih; Lin, Wang-Hua; Chiu, Sheng-Cheng; Huang, Chien-Fa; Yu, Hsin-Chih; Hsu, Jen-Sung; Li, Yuan-Yao

    2011-03-01

    A carbonyl iron/carbon fiber material consisting of carbon fibers grown on micrometer-sized carbonyl iron sphere, was synthesized by chemical vapor deposition using a mixture of C2H2 and H2. The hollow-core carbon fibers (outer diameter: 140 nm and inner diameter: 40 nm) were composed of well-ordered graphene layers which were almost parallel to the long axis of the fibers. A composite (2 mm thick) consisting of the carbonyl iron/carbon fibers and epoxy resin demonstrated excellent electromagnetic (EM) wave absorption. Minimum reflection losses of -36 dB (99.95% of EM wave absorption) at 7.6 GHz and -32 dB (99.92% of EM wave absorption) at 34.1 GHz were achieved. The well-dispersed and network-like carbon fibers in the resin matrix affected the dielectric loss of the EM wave while the carbonyl iron affected the magnetic loss. PMID:21449387

  4. Synthesis of 2-Alkynoates by Palladium(II)-Catalyzed Oxidative Carbonylation of Terminal Alkynes and Alcohols.

    PubMed

    Cao, Qun; Hughes, N Louise; Muldoon, Mark J

    2016-08-16

    A homogeneous Pd(II) catalyst, utilizing a simple and inexpensive amine ligand (TMEDA), allows 2-alkynoates to be prepared in high yields by an oxidative carbonylation of terminal alkynes and alcohols. The catalyst system overcomes many of the limitations of previous palladium carbonylation catalysts. It has an increased substrate scope, avoids large excesses of alcohol substrate and uses a desirable solvent. The catalyst employs oxygen as the terminal oxidant and can be operated under safer gas mixtures. PMID:27305489

  5. Protein carbonylation and aggregation precede neuronal apoptosis induced by partial glutathione depletion

    PubMed Central

    Dasgupta, Anushka; Zheng, Jianzheng; Bizzozero, Oscar A.

    2012-01-01

    While the build-up of oxidized proteins within cells is believed to be toxic, there is currently no evidence linking protein carbonylation and cell death. In the present study, we show that incubation of nPC12 (neuron-like PC12) cells with 50 μM DEM (diethyl maleate) leads to a partial and transient depletion of glutathione (GSH). Concomitant with GSH disappearance there is increased accumulation of PCOs (protein carbonyls) and cell death (both by necrosis and apoptosis). Immunocytochemical studies also revealed a temporal/spatial relationship between carbonylation and cellular apoptosis. In addition, the extent of all three, PCO accumulation, protein aggregation and cell death, augments if oxidized proteins are not removed by proteasomal degradation. Furthermore, the effectiveness of the carbonyl scavengers hydralazine, histidine hydrazide and methoxylamine at preventing cell death identifies PCOs 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. While the study focused mostly on nPC12 cells, experiments in primary neuronal cultures yielded the same results. The findings are also not restricted to DEM-induced cell death, since a similar relationship between carbonylation and apoptosis was found in staurosporine- and buthionine sulfoximine-treated nPC12 cells. In sum, the above results show for the first time a causal relationship between carbonylation, protein aggregation and apoptosis of neurons undergoing oxidative damage. To the best of our knowledge, this is the first study to place direct (oxidative) protein carbonylation within the apoptotic pathway. PMID:22376187

  6. (2.2.2-Cryptand)potassium tetra­carbonyl­cobaltate(−I)

    PubMed Central

    Brennessel, William W.; Ellis, John E.

    2014-01-01

    The title salt, [K(C18H36N2O6)][Co(CO)4], is an example of a classical carbonyl­metalate. The asymmetric unit contains one cation and one tetrahedral anion, both in general positions. Based on comparison of the four carbonyl C—O bond lengths and C—Co—C angles, the anion is unperturbed by the cation, which is normal for an alkali metal fully encased by a cryptand cage. PMID:24860312

  7. Carbonyl Compounds in Electronic Cigarette Vapors: Effects of Nicotine Solvent and Battery Output Voltage

    PubMed Central

    Kosmider, Leon; Sobczak, Andrzej; Fik, Maciej; Knysak, Jakub; Zaciera, Marzena; Kurek, Jolanta

    2014-01-01

    Introduction: Glycerin (VG) and propylene glycol (PG) are the most common nicotine solvents used in e-cigarettes (ECs). It has been shown that at high temperatures both VG and PG undergo decomposition to low molecular carbonyl compounds, including the carcinogens formaldehyde and acetaldehyde. The aim of this study was to evaluate how various product characteristics, including nicotine solvent and battery output voltage, affect the levels of carbonyls in EC vapor. Methods: Twelve carbonyl compounds were measured in vapors from 10 commercially available nicotine solutions and from 3 control solutions composed of pure glycerin, pure propylene glycol, or a mixture of both solvents (50:50). EC battery output voltage was gradually modified from 3.2 to 4.8V. Carbonyl compounds were determined using the HPLC/DAD method. Results: Formaldehyde and acetaldehyde were found in 8 of 13 samples. The amounts of formaldehyde and acetaldehyde in vapors from lower voltage EC were on average 13- and 807-fold lower than in tobacco smoke, respectively. The highest levels of carbonyls were observed in vapors generated from PG-based solutions. Increasing voltage from 3.2 to 4.8V resulted in a 4 to more than 200 times increase in formaldehyde, acetaldehyde, and acetone levels. The levels of formaldehyde in vapors from high-voltage device were in the range of levels reported in tobacco smoke. Conclusions: Vapors from EC contain toxic and carcinogenic carbonyl compounds. Both solvent and battery output voltage significantly affect levels of carbonyl compounds in EC vapors. High-voltage EC may expose users to high levels of carbonyl compounds. PMID:24832759

  8. Effects of low doses of quercetin and genistein on oxidation and carbonylation in hemoglobin and myoglobin.

    PubMed

    Boadi, William Y; Johnson, Damitea

    2014-09-01

    Protein-bound carbonyls have been shown to increase with age as well as in numerous diseases including rheumatoid arthritis, adult respiratory syndrome pulmonary fibrosis, diabetes, Parkinson's disease, and Alzheimer's just to mention a few. The effects of the flavonoids quercetin and genistein were investigated according to their ability to inhibit the oxidation of hemoglobin and myoglobin via the Fenton's pathway. Antioxidative activity of the flavonoids were determined by oxidizing hemoglobin and myoglobin in separate experiments with 50 μM Fe(2+) and 0.01 mM hydrogen peroxide (H2O2) with and without quercetin and/or genistein. The samples were treated singly with either quercetin, genistein, or in combination at concentrations of 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 μM, respectively, dissolved in dimethyl sulfoxide (DMSO). Samples were then incubated in a water bath at 37°C for 8, 12, and 24 hr, respectively. Levels of carbonylation were assayed by the protein carbonyl assay and the carbonyl levels quantified and expressed per mg of protein. The results indicate that protein carbonyls for samples treated with quercetin or genistein decreased in a dose-dependent manner compared to the controls. That of quercetin compared to genistein was more efficient in reducing the levels of protein carbonylation in hemoglobin and myoglobin, respectively. The combination of both flavonoids did show a gradual decrease in carbonyl compounds for only hemoglobin for all the doses and times tested. The results indicate that both flavonoids at low doses inhibited carbonylation in both hemoglobin and myoglobin and the inhibition may be attributed to the prevention of protein oxidation. PMID:25026201

  9. 1,2,3-Triazoles from carbonyl azides and alkynes: filling the gap.

    PubMed

    Haldón, Estela; Álvarez, Eleuterio; Nicasio, M Carmen; Pérez, Pedro J

    2014-08-18

    Electron deficient azides are challenging substrates in CuAAC reactions. Particularly, when N-carbonyl azides are applied the formation of N-carbonyl triazoles has not yet been observed. We report herein the first example of this class of reaction, with a copper-based system that efficiently enables the synthesis of N-carbamoyl 1,2,3-triazoles by [3+2] cycloaddition of N-carbamoyl azides and alkynes. PMID:24980244

  10. The Epoxidation of Carbonyl Compounds with a Benzyne-Triggered Sulfur Ylide.

    PubMed

    Lou, Mei-Mei; Wang, Han; Song, Li; Liu, Hong-Yi; Li, Zhong-Qiu; Guo, Xiao-Shuang; Zhang, Fu-Geng; Wang, Bin

    2016-07-15

    An efficient method for the synthesis of epoxides from carbonyl compounds, sulfoxides, and benzyne is presented. The strategy involved an epoxidation by a sulfur ylide which is formed in situ from sulfoxide and benzyne through the S-O bond insertion and deprotonation. This one-pot reaction proceeds under mild and base-free conditions, providing a convenient way to introduce the substituted methylene groups onto the carbonyl carbon. PMID:27337065

  11. Carbonyl sulfide and carbon disulfide from the eruptions of Mount St. Helens

    SciTech Connect

    Rasmussen, R.A.; Khalil, M.A.K.; Dalluge, R.W.; Penkett, S.A.; Jones, B.

    1982-01-01

    Ash from the massive 18 May 1980 eruption of Mount St. Helens readily gave off large amounts of carbonyl sulfide and carbon disulfide gases at room temperature. These findings suggest that the sulfur that enhances the Junge sulfate layer in the stratosphere after volcanic eruptions could be carried directly to the upper atmosphere as carbonyl sulfide and carbon disulfide adsorbed on ash particles from major volcanic eruptions.

  12. Carbonyl sulfide and carbon disulfide from the eruptions of mount st. Helens.

    PubMed

    Rasmussen, R A; Khalil, M A; Dalluge, R W; Penkett, S A; Jones, B

    1982-02-01

    Ash from the massive 18 May 1980 eruption of Mount St. Helens readily gave off large amounts of carbonyl sulfide and carbon disulfide gases at room temperature. These findings suggest that the sulfur that enhances the Junge sulfate layer in the stratosphere after volcanic eruptions could be carried directly to the upper atmosphere as carbonyl sulfide and carbon disulfide adsorbed on ash particles from major volcanic eruptions. PMID:17842402

  13. Perceptions of document relevance

    PubMed Central

    Bruza, Peter; Chang, Vivien

    2014-01-01

    This article presents a study of how humans perceive and judge the relevance of documents. Humans are adept at making reasonably robust and quick decisions about what information is relevant to them, despite the ever increasing complexity and volume of their surrounding information environment. The literature on document relevance has identified various dimensions of relevance (e.g., topicality, novelty, etc.), however little is understood about how these dimensions may interact. We performed a crowdsourced study of how human subjects judge two relevance dimensions in relation to document snippets retrieved from an internet search engine. The order of the judgment was controlled. For those judgments exhibiting an order effect, a q–test was performed to determine whether the order effects can be explained by a quantum decision model based on incompatible decision perspectives. Some evidence of incompatibility was found which suggests incompatible decision perspectives is appropriate for explaining interacting dimensions of relevance in such instances. PMID:25071622

  14. Proteomic analysis of carbonylated proteins in the monkey substantia nigra after ischemia-reperfusion.

    PubMed

    Oikawa, Shinji; Kobayashi, Hatasu; Kitamura, Yuki; Zhu, Hong; Obata, Kumi; Minabe, Yoshio; Dazortsava, Maryia; Ohashi, Kyoko; Tada-Oikawa, Saeko; Takahashi, Hitoshi; Yata, Kenichiro; Murata, Mariko; Yamashima, Tetsumori

    2014-06-01

    In Parkinson's disease (PD), oxidative stresses cause cell death of dopaminergic neurons of the substantia nigra (SN), but its molecular mechanism still remains unclarified. Our previous study of proteomic analysis in the monkey CA1 hippocampus after ischemia-reperfusion revealed reactive oxygen species (ROS)-induced carbonyl modification of a molecular chaperone, heat shock 70-kDa protein 1 (Hsp70.1), especially in its key site, Arg469. Here, to clarify the mechanism of neurodegeneration in PD, the SN tissue of the same monkey experimental paradigm was studied for identifying and characterizing carbonylated proteins by the two-dimensional gel electrophoresis with immunochemical detection of protein carbonyls (2D Oxyblot). We found carbonyl modification not only of Hsp70.1 but also of mitochondrial aconitase, dihydropyrimidinase-related protein 2, T-complex protein 1 subunit alpha, dihydrolipoyl dehydrogenase, fructose-bisphosphate aldolase C, glutamate dehydrogenase 1, and aspartate aminotransferase. Intriguingly, in the SN also, the carbonylation site of Hsp70.1 was identified to be Arg469. Since Hsp70.1 is recently known to stabilize the lysosomal membrane, its oxidative injury conceivably plays an important role in the ROS-mediated neuronal cell death by inducing lysosomal destabilization. Implications of each carbonylated proteins for the dopaminergic neuronal death were discussed, in comparison with the CA1 neuronal death. PMID:24697733

  15. Detection of oxidative stress-induced carbonylation in live mammalian cells.

    PubMed

    Mukherjee, Kamalika; Chio, Tak Ian; Sackett, Dan L; Bane, Susan L

    2015-07-01

    Oxidative stress is often associated with etiology and/or progression of disease conditions, such as cancer, neurodegenerative diseases, and diabetes. At the cellular level, oxidative stress induces carbonylation of biomolecules such as lipids, proteins, and DNA. The presence of carbonyl-containing biomolecules as a hallmark of these diseases provides a suitable target for diagnostic detection. Here, a simple, robust method for detecting cellular aldehydes and ketones in live cells using a fluorophore is presented. A hydrazine-functionalized synthetic fluorophore serves as an efficient nucleophile that rapidly reacts with reactive carbonyls in the cellular milieu. The product thus formed exhibits a wavelength shift in the emission maximum accompanied by an increase in emission intensity. The photochemical characteristics of the fluorophore enable the identification of the fluorophore-conjugated cellular biomolecules in the presence of unreacted dye, eliminating the need for removal of excess fluorophore. Moreover, this fluorophore is found to be nontoxic and is thus appropriate for live cell analysis. Utility of the probe is demonstrated in two cell lines, PC3 and A549. Carbonylation resulting from serum starvation and hydrogen peroxide-induced stress is detected in both cell lines using fluorescence microscopy and a fluorescence plate reader. The fluorescent signal originates from carbonylated proteins and lipids but not from oxidized DNA, and the majority of the fluorescence signal (>60%) is attributed to fluorophore-conjugated lipid oxidation products. This method should be useful for detecting cellular carbonylation in a high-content assay or high-throughput assay format. PMID:25801292

  16. Oxidative Stress and Carbonyl Lesions in Ulcerative Colitis and Associated Colorectal Cancer

    PubMed Central

    Wang, Zhiqi; Li, Sai; Cao, Yu; Tian, Xuefei; Zeng, Rong; Liao, Duan-Fang; Cao, Deliang

    2016-01-01

    Oxidative stress has long been known as a pathogenic factor of ulcerative colitis (UC) and colitis-associated colorectal cancer (CAC), but the effects of secondary carbonyl lesions receive less emphasis. In inflammatory conditions, reactive oxygen species (ROS), such as superoxide anion free radical (O2∙−), hydrogen peroxide (H2O2), and hydroxyl radical (HO∙), are produced at high levels and accumulated to cause oxidative stress (OS). In oxidative status, accumulated ROS can cause protein dysfunction and DNA damage, leading to gene mutations and cell death. Accumulated ROS could also act as chemical messengers to activate signaling pathways, such as NF-κB and p38 MAPK, to affect cell proliferation, differentiation, and apoptosis. More importantly, electrophilic carbonyl compounds produced by lipid peroxidation may function as secondary pathogenic factors, causing further protein and membrane lesions. This may in turn exaggerate oxidative stress, forming a vicious cycle. Electrophilic carbonyls could also cause DNA mutations and breaks, driving malignant progression of UC. The secondary lesions caused by carbonyl compounds may be exceptionally important in the case of host carbonyl defensive system deficit, such as aldo-keto reductase 1B10 deficiency. This review article updates the current understanding of oxidative stress and carbonyl lesions in the development and progression of UC and CAC. PMID:26823956

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

    NASA Astrophysics Data System (ADS)

    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.

  18. A new agent for derivatizing carbonyl species used to investigate limonene ozonolysis

    NASA Astrophysics Data System (ADS)

    Wells, J. R.; Ham, Jason E.

    2014-12-01

    A new method for derivatizing carbonyl compounds is presented. The conversion of a series of dicarbonyls to oximes in aqueous solution and from gas-phase sampling was achieved using O-tert-butylhydroxylamine hydrochloride (TBOX). Some advantages of using this derivatization agent include: aqueous reactions, lower molecular weight oximes, and shortened oxime-formation reaction time. Additionally, the TBOX derivatization technique was used to investigate the carbonyl reaction products from limonene ozonolysis. With ozone (O3) as the limiting reagent, four carbonyl compounds were detected: 7-hydroxy-6-oxo-3-(prop-1-en-2-yl)heptanal; 3-Isopropenyl-6-oxoheptanal (IPOH), 3-acetyl-6-oxoheptanal (3A6O) and one carbonyl of unknown structure. Using cyclohexane as a hydroxyl (OHrad) radical scavenger, the relative yields (peak area) of the unknown carbonyl, IPOH, and 3A6O were reduced indicating the influence secondary OH radicals have on limonene ozonolysis products. The relative yield of the hydroxy-dicarbonyl based on the chromatogram was unchanged suggesting it is only made by the limonene + O3 reaction. The detection of 3A6O using TBOX highlights the advantages of a smaller molecular weight derivatization agent for the detection of multi-carbonyl compounds. The use of TBOX derivatization if combined with other derivatization agents may address a recurring need to simply and accurately detect multi-functional oxygenated species in air.

  19. Linking the leaf uptake of carbonyl sulfide (COS) to transpiration, photosynthesis and carbon isotope fractionation

    NASA Astrophysics Data System (ADS)

    Seibt, U.; Kesselmeier, J.; Berry, J. A.

    2009-12-01

    Carbonyl sulfide (COS) is an atmospheric trace gas that holds great promise for studies of terrestrial carbon and water exchange. In leaves, COS follows the same pathway as CO2 during photosynthesis. Both gases are taken up in enzyme reactions, making COS and CO2 uptake closely coupled at the leaf scale. Based on the biological background of leaf COS uptake, a hydrolysis reaction catalyzed by carbonic anhydrase, we derive and test a simple kinetic model of leaf COS uptake, and relate COS to CO2 and water fluxes at the leaf scale. The equation predicts realistic COS fluxes compared to observations from laboratory and field chambers. The model directly relates COS uptake at the leaf level to stomatal conductance. As a consequence, the ratio of deposition velocities (uptake rate divided by ambient mole fraction) for leaf COS and CO2 fluxes can provide an estimate of Ci/Ca, the ratio of intercellular to atmospheric CO2, an important plant gas exchange parameter that cannot be measured directly. The majority of published deposition velocity ratios for leaf studies on a variety of species fall in the range of 1.5 to 4, corresponding to Ci/Ca ratios of 0.5 to 0.8. In addition, we utilize the coupling of Ci/Ca and photosynthetic 13C discrimination to derive an estimate of 2.8 ± 0.3 for the global mean ratio of deposition velocities. This corresponds to a global vegetation sink of COS in the order of 900 ± 100 GgS/yr. COS can now be implemented in the same model framework as CO2 and water vapour. This will provide the foundation to obtain independent constraints on CO2 and water cycles from atmospheric COS measurements at ecosystem, regional and global scales.

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

    NASA Astrophysics Data System (ADS)

    Dasgupta, Anushka

    Many studies have suggested that oxidative stress plays an important role in the pathophysiology of both multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Yet, the mechanism by which oxidative stress leads to tissue damage in these disorders is unclear. Recent work from our laboratory has revealed that protein carbonylation, a major oxidative modification caused by severe and/or chronic oxidative stress conditions, is elevated in MS and EAE. Furthermore, protein carbonylation has been shown to alter protein structure leading to misfolding/aggregation. These findings prompted me to hypothesize that carbonylated proteins, formed as a consequence of oxidative stress and/or decreased proteasomal activity, promote protein aggregation to mediate neuronal apoptosis in vitro and in EAE. To test this novel hypothesis, I first characterized protein carbonylation, protein aggregation and apoptosis along the spinal cord during the course of myelin-oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE in C57BL/6 mice [Chapter 2]. The results show that carbonylated proteins accumulate throughout the course of the disease, albeit by different mechanisms: increased oxidative stress in acute EAE and decreased proteasomal activity in chronic EAE. I discovered not only that there is a temporal correlation between protein carbonylation and apoptosis but also that carbonyl levels are significantly higher in apoptotic cells. A high number of juxta-nuclear and cytoplasmic protein aggregates containing the majority of the oxidized proteins are also present during the course of EAE, which seems to be due to reduced autophagy. In chapter 3, I show that when gluthathione levels are reduced to those in EAE spinal cord, both neuron-like PC12 (nPC12) cells and primary neuronal cultures accumulate carbonylated proteins and undergo cell death (both by necrosis and apoptosis). Immunocytochemical and biochemical studies also revealed a temporal

  1. Mesoporous Silica-Supported Amidozirconium-Catalyzed Carbonyl Hydroboration

    DOE PAGESBeta

    Eedugurala, Naresh; Wang, Zhuoran; Chaudhary, Umesh; Nelson, Nicholas; Kandel, Kapil; Kobayashi, Takeshi; Slowing, Igor I.; Pruski, Marek; Sadow, Aaron D.

    2015-11-04

    The hydroboration of aldehydes and ketones using a silica-supported zirconium catalyst is reported. Reaction of Zr(NMe2)4 and mesoporous silica nanoparticles (MSN) provides the catalytic material Zr(NMe2)n@MSN. Exhaustive characterization of Zr(NMe2)n@MSN with solid-state (SS)NMR and infrared spectroscopy, as well as through reactivity studies, suggests its surface structure is primarily ≡SiOZr(NMe2)3. The presence of these nitrogen-containing zirconium sites is supported by 15N NMR spectroscopy, including natural abundance 15N NMR measurements using dynamic nuclear polarization (DNP) SSNMR. The Zr(NMe2)n@MSN material reacts with pinacolborane (HBpin) to provide Me2NBpin and the material ZrH/Bpin@MSN that is composed of interacting surface-bonded zirconium hydride and surface-bonded borane ≡SiOBpinmore » moieties in an approximately 1:1 ratio, as well as zirconium sites coordinated by dimethylamine. The ZrH/Bpin@MSN is characterized by 1H/2H and 11B SSNMR and infrared spectroscopy and through its reactivity with D2. The zirconium hydride material or the zirconium amide precursor Zr(NMe2)n@MSN catalyzes the selective hydroboration of aldehydes and ketones with HBpin in the presence of functional groups that are often reduced under hydroboration conditions or are sensitive to metal hydrides, including olefins, alkynes, nitro groups, halides, and ethers. Remarkably, this catalytic material may be recycled without loss of activity at least eight times, and air-exposed materials are catalytically active. These supported zirconium centers are robust catalytic sites for carbonyl reduction and that surface-supported, catalytically reactive zirconium hydride may be generated from zirconium-amide or zirconium alkoxide sites.« less

  2. Intramolecular hydrogen bond in biologically active o-carbonyl hydroquinones.

    PubMed

    Martínez-Cifuentes, Maximiliano; Weiss-López, Boris E; Santos, Leonardo S; Araya-Maturana, Ramiro

    2014-01-01

    Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculations at the DFT and ab initio levels. Natural bond orbital (NBO) and molecular electrostatic potential (MEP) calculations were used to study the electronic characteristics of these IHB. As expected, our results show that NBO calculations are better than MEP to describe the strength of the IHBs. NBO energies (∆Eij(2)) show that the main contributions to energy stabilization correspond to LP-->σ* interactions for IHBs, O1…O2-H2 and the delocalization LP-->π* for O2-C2=Cα(β). For the O1…O2-H2 interaction, the values of ∆Eij(2) can be attributed to the difference in the overlap ability between orbitals i and j (Fij), instead of the energy difference between them. The large energy for the LP O2-->π* C2=Cα(β) interaction in the compounds 9-Hydroxy-5-oxo-4,8, 8-trimethyl-l,9(8H)-anthracenecarbolactone (VIII) and 9,10-dihydroxy-4,4-dimethylanthracen-1(4H)-one (VII) (55.49 and 60.70 kcal/mol, respectively) when compared with the remaining molecules (all less than 50 kcal/mol), suggests that the IHBs in VIII and VII are strongly resonance assisted. PMID:24995921

  3. Soil fluxes of carbonyl sulfide (COS) across four distinct ecosystems

    NASA Astrophysics Data System (ADS)

    Sun, W.; Maseyk, K. S.; Lett, C.; Juarez, S.; Kooijmans, L.; Mammarella, I.; Vesala, T.; Chen, H.; Seibt, U.

    2015-12-01

    Soils are additional but poorly resolved sinks of carbonyl sulfide (COS) in terrestrial ecosystems. COS has been proposed as a tracer for quantifying gross photosynthesis based on the coupled stomatal uptake of COS and CO2. But applying this tracer requires the soil COS flux to be subtracted from the ecosystem flux to obtain the actual plant flux. To simulate soil COS fluxes, we have built a 1-D diffusion-reaction model accounting for vertical transport in the soil, microbial sinks and sources, and a litter layer. Uptake and production of COS in the soil column are linked with soil temperature and moisture through empirical functions adapted from enzyme kinetics and lab incubations. We have measured soil COS fluxes and the related soil variables in four distinct ecosystems: a wheat field (Southern Great Plains, OK, USA), an oak woodland (Santa Monica Mountains, CA, USA), a tropical rainforest (La Selva Biological Station, Costa Rica) and a boreal pine forest (Hyytiälä, Finland). Across all sites, a lower soil temperature and a humid climate are generally favorable to soil COS uptake. Strong COS emissions were observed in the wheat field at high soil temperatures after harvesting but were absent in other ecosystems, indicating that COS exchange may behave differently in agricultural soils. We simulated the soil fluxes in all ecosystems using the diffusion-reaction model, and optimized the source/sink strength parameters with field data. The optimized model provides insights that are not attainable from data analysis alone: For example, the wheat field soil must have continued uptake activity even when it showed net emissions, and leaf litter contributed dominantly to the COS sink after rain in the oak woodland. We expect the new model to be useful for simulating global soil COS fluxes as field data on soil fluxes from a broader range of ecosystems become available.

  4. New Ir Bis-Carbonyl Precursor for Water Oxidation Catalysis.

    PubMed

    Huang, Daria L; Beltrán-Suito, Rodrigo; Thomsen, Julianne M; Hashmi, Sara M; Materna, Kelly L; Sheehan, Stafford W; Mercado, Brandon Q; Brudvig, Gary W; Crabtree, Robert H

    2016-03-01

    This paper introduces Ir(I)(CO)2(pyalc) (pyalc = (2-pyridyl)-2-propanoate) as an atom-efficient precursor for Ir-based homogeneous oxidation catalysis. This compound was chosen to simplify analysis of the water oxidation catalyst species formed by the previously reported Cp*Ir(III)(pyalc)OH water oxidation precatalyst. Here, we present a comparative study on the chemical and catalytic properties of these two precursors. Previous studies show that oxidative activation of Cp*Ir-based precursors with NaIO4 results in formation of a blue Ir(IV) species. This activation is concomitant with the loss of the placeholder Cp* ligand which oxidatively degrades to form acetic acid, iodate, and other obligatory byproducts. The activation process requires substantial amounts of primary oxidant, and the degradation products complicate analysis of the resulting Ir(IV) species. The species formed from oxidation of the Ir(CO)2(pyalc) precursor, on the other hand, lacks these degradation products (the CO ligands are easily lost upon oxidation) which allows for more detailed examination of the resulting Ir(pyalc) active species both catalytically and spectroscopically, although complete structural analysis is still elusive. Once Ir(CO)2(pyalc) is activated, the system requires acetic acid or acetate to prevent the formation of nanoparticles. Investigation of the activated bis-carbonyl complex also suggests several Ir(pyalc) isomers may exist in solution. By (1)H NMR, activated Ir(CO)2(pyalc) has fewer isomers than activated Cp*Ir complexes, allowing for advanced characterization. Future research in this direction is expected to contribute to a better structural understanding of the active species. A diol crystallization agent was needed for the structure determination of 3. PMID:26901517

  5. Rigor, Relevance and Relationships

    ERIC Educational Resources Information Center

    McNulty, Raymond J.; Quaglia, Russell J.

    2007-01-01

    Rigor, relevance, and relationships are three elements that provide the hallmark for education today. These three elements are integrally connected; if one is missing in a teacher's teaching practices, he or she is not doing his or her best to prepare students for success in school and in life. To ensure the inclusion of both rigor and relevance,…

  6. Making Science Relevant

    ERIC Educational Resources Information Center

    Eick, Charles; Deutsch, Bill; Fuller, Jennifer; Scott, Fletcher

    2008-01-01

    Science teachers are always looking for ways to demonstrate the relevance of science to students. By connecting science learning to important societal issues, teachers can motivate students to both enjoy and engage in relevant science (Bennet, Lubben, and Hogarth 2007). To develop that connection, teachers can help students take an active role in…

  7. Culturally Relevant Pedagogy

    ERIC Educational Resources Information Center

    Irvine, Jacqueline Jordan

    2010-01-01

    Many teachers have only a cursory understanding of culturally relevant pedagogy, and their efforts to bridge the cultural gap often fall short. Culturally relevant pedagogy is a term that describes effective teaching in culturally diverse classrooms. It can be a daunting idea to understand and implement. Yet people tend to appreciate culturally…

  8. Secondary Organic Aerosol (SOA) production from the Aqueous Reactions of Phenols and Triplet Aromatic Carbonyls

    NASA Astrophysics Data System (ADS)

    Smith, J.; Sun, Y.; Lu, Y.; Zhang, Q.; Anastasio, C.

    2010-12-01

    The phenolic compounds guaiacol, syringol and phenol have recently been shown to produce secondary organic aerosol (SOA) at high yields in the aqueous phase upon exposure to simulated sunlight and hydroxyl radical. These phenols are significant products from wood combustion that can readily enter atmospheric waters, such as aqueous aerosol particles and cloud/fog droplets. Once in the aqueous phase, phenols can react with the triplet excited states of non-phenolic aromatic carbonyls (NPCs), particle-bound organics that are also emitted from wood combustion. In this study, we examined the aqueous-phase production of SOA from the reaction of phenolic compounds with triplet excited state organics. These aqueous phase reactions were tested by illuminating solutions containing a phenolic compound and NPC under simulated sunlight at various concentrations and pH values. The phenolic compound is consumed during these reactions, following a first-order decay that varies with phenol concentration, phenol identity, and pH. The non-volatile product mass formed in our illuminated solutions was determined gravimetrically and by analysis with High Resolution Time of Flight Aerosol Mass Spectrometry (HR-AMS). The SOA mass yield was determined as the mass of non-volatile product formed per mass of phenolic consumed during illumination. We also used HR-AMS to analyze for elemental composition, carbon oxidation state, and oligomers in the SOA produced. Our results to date indicate that phenols can be rapidly oxidized by triplet excited states under environmentally relevant conditions and that the accompanying SOA mass yields are very high.

  9. Kinetics of Reversible Reductive Carbonylation of Heme in Human Cystathionine β-synthase†

    PubMed Central

    Carballal, Sebastián; Cuevasanta, Ernesto; Marmisolle, Inés; Kabil, Omer; Gherasim, Carmen; Ballou, David P.; Banerjee, Ruma; Alvarez, Beatriz

    2013-01-01

    Cystathionine β-synthase (CBS) catalyzes the condensation of homocysteine with serine or cysteine to form cystathionine and water or hydrogen sulfide (H2S), respectively. In addition to pyridoxal phosphate, human CBS has a heme cofactor with cysteine and histidine as ligands. While Fe(III)-CBS is inert to exogenous ligands, Fe(II)-CBS can be reversibly inhibited by carbon monoxide (CO) and reoxidized by O2 to yield superoxide radical. In this study, we have examined the kinetics of Fe(II)CO-CBS formation and reoxidation. Reduction of Fe(III)-CBS by dithionite showed square root dependence on concentration, indicating that the reductant species was the sulfur dioxide radical anion (SO2•−) that exists in rapid equilibrium with S2O42−. Formation of Fe(II)CO-CBS from Fe(II)-CBS and 1 mM CO occurred at (3.1 ± 0.4) × 10−3 s−1 (pH 7.4, 25 °C). The reaction of Fe(III)-CBS with the reduced form of the flavoprotein methionine synthase reductase in the presence of CO and NADPH resulted in its reduction and carbonylation to form Fe(II)CO-CBS. Fe(II)-CBS was formed as intermediate with a rate constant of (9.3 ± 2.5) × 102 M−1 s−1. Reoxidation of Fe(II)CO-CBS by O2 was multiphasic. The major phase showed hyperbolic dependence on O2 concentration. Although H2S is a product of the CBS reaction and a potential heme ligand, we did not find evidence for exogenous H2S effect on activity or heme binding. Reversible reduction of CBS by a physiologically relevant oxidoreductase is consistent with a regulatory role for the heme and could constitute a mechanism for crosstalk between the CO, H2S and superoxide signaling pathways. PMID:23790103

  10. Proteomic identification of carbonylated proteins in F344 rat hippocampus after 1-bromopropane exposure

    SciTech Connect

    Huang, Zhenlie; Ichihara, Sahoko; Oikawa, Shinji; Chang, Jie; Zhang, Lingyi; Subramanian, Kaviarasan; Mohideen, Sahabudeen Sheik; Ichihara, Gaku

    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.

  11. Mesoporous Silica-Supported Amidozirconium-Catalyzed Carbonyl Hydroboration

    SciTech Connect

    Eedugurala, Naresh; Wang, Zhuoran; Chaudhary, Umesh; Nelson, Nicholas; Kandel, Kapil; Kobayashi, Takeshi; Slowing, Igor I.; Pruski, Marek; Sadow, Aaron D.

    2015-11-04

    The hydroboration of aldehydes and ketones using a silica-supported zirconium catalyst is reported. Reaction of Zr(NMe2)4 and mesoporous silica nanoparticles (MSN) provides the catalytic material Zr(NMe2)n@MSN. Exhaustive characterization of Zr(NMe2)n@MSN with solid-state (SS)NMR and infrared spectroscopy, as well as through reactivity studies, suggests its surface structure is primarily ≡SiOZr(NMe2)3. The presence of these nitrogen-containing zirconium sites is supported by 15N NMR spectroscopy, including natural abundance 15N NMR measurements using dynamic nuclear polarization (DNP) SSNMR. The Zr(NMe2)n@MSN material reacts with pinacolborane (HBpin) to provide Me2NBpin and the material ZrH/Bpin@MSN that is composed of interacting surface-bonded zirconium hydride and surface-bonded borane ≡SiOBpin moieties in an approximately 1:1 ratio, as well as zirconium sites coordinated by dimethylamine. The ZrH/Bpin@MSN is characterized by 1H/2H and 11B SSNMR and infrared spectroscopy and through its reactivity with D2. The zirconium hydride material or the zirconium amide precursor Zr(NMe2)n@MSN catalyzes the selective hydroboration of aldehydes and ketones with HBpin in the presence of functional groups that are often reduced under hydroboration conditions or are sensitive to metal hydrides, including olefins, alkynes, nitro groups, halides, and ethers. Remarkably, this catalytic material may be recycled without loss of activity at least eight times, and air-exposed materials are catalytically active. These supported zirconium centers are robust catalytic sites for carbonyl reduction and that surface-supported, catalytically reactive zirconium hydride may be generated from zirconium-amide or zirconium alkoxide sites.

  12. Positive trends in Southern Hemisphere observations of carbonyl sulfide

    NASA Astrophysics Data System (ADS)

    Kremser, Stefanie; Jones, Nicholas; Smale, Dan; Palm, Mathias; Lejeune, Bernard; Wang, Yuting; Deutscher, Nicholas

    2016-04-01

    Carbonyl sulfide (OCS; lifetime of about 5.7 years) is the longest lived reduced sulfur-containing gas in the atmosphere. The primary source of OCS is the ocean, which is both a direct source (through OCS emission) and an indirect source (due to oxidation of carbon disulfide, CS2, and dimethyl sulfide). Other natural sources of OCS include volcanic outgassing and direct fluxes from wetland regions. The removal of OCS from the atmosphere is dominated by soil and vegetation uptake, with minor contributions from reactions with the hydroxyl radical. Small anthropogenic sources of OCS are coal combustion, biomass burning, and aluminum production. A dominant indirect source results from CS2 emissions from the rayon industry. Transport of tropospheric OCS to the stratosphere during volcanically quiescent periods has been suggested to contribute sulfur to the stratospheric aerosol layer which affects atmospheric radiative balance. If, however, production of stratospheric aerosols from OCS oxidation is smaller than typical estimates, this OCS contribution would be overestimated. The magnitude of the OCS flux to the stratosphere is currently not well quantified as is the relative contribution of OCS to background aerosol loading. While earlier model simulations indicate OCS fluxes into the atmosphere exceeding removal, past total column observations of OCS show no significant trend. Analysis of tropospheric OCS columns at Arrival Heights (Antarctica) and Lauder (New Zealand) show strong positive trends from 2001-2008 followed by weaker trends to 2015, with unexpected temporal coherence. Since trends in ocean and land sources/sinks at these two sites, respectively, are unlikely to be similar, the coherence in trend structure likely results from changes in transport of OCS from the tropics to middle and high latitudes. Potential causes for OCS increases are (i) increases in tropical lower stratospheric OCS and/or (ii) strengthening of the large-scale circulation which

  13. Stéréochimie de la liaison hydrogène sur le groupe carbonyle

    NASA Astrophysics Data System (ADS)

    Laurence, Christian; Berthelot, Michel; Helbert, Maryvonne

    The asymmetric shape or splitting of the ν(XH) or ν(XD) bands of OH(OD), NH, SH and CH proton donors hydrogen bonded to the carbonyl group of ketones, aldehydes, esters, amides, ureas and carbamates have been explained by the existence of two stereoisomeric complexes: a linear complex (along the axis of the carbonyl bond) and an angular complex (in the direction of a lone pair). Bulky substituents on the carbonyl group or near the XH bond destabilize the angular arrangement. Inductive electron-withdrawing substituents on the carbonyl group favour the linear arrangement.

  14. Quantitative modeling of bioconcentration factors of carbonyl herbicides using multivariate image analysis.

    PubMed

    Freitas, Mirlaine R; Barigye, Stephen J; Daré, Joyce K; Freitas, Matheus P

    2016-06-01

    The bioconcentration factor (BCF) is an important parameter used to estimate the propensity of chemicals to accumulate in aquatic organisms from the ambient environment. While simple regressions for estimating the BCF of chemical compounds from water solubility or the n-octanol/water partition coefficient have been proposed in the literature, these models do not always yield good correlations and more descriptive variables are required for better modeling of BCF data for a given series of organic pollutants, such as some herbicides. Thus, the logBCF values for a set of carbonyl herbicides comprising amide, urea, carbamate and thiocarbamate groups were quantitatively modeled using multivariate image analysis (MIA) descriptors, derived from colored image representations for chemical structures. The logBCF model was calibrated and vigorously validated (r(2) = 0.79, q(2) = 0.70 and rtest(2) = 0.81), providing a comprehensive three-parameter linear equation after variable selection (logBCF = 5.682 - 0.00233 × X9774 - 0.00070 × X813 - 0.00273 × X5144); the variables represent pixel coordinates in the multivariate image. Finally, chemical interpretation of the obtained models in terms of the structural characteristics responsible for the enhanced or reduced logBCF values was performed, providing key leads in the prospective development of more eco-friendly synthetic herbicides. PMID:26971171

  15. Improving North American gross primary production (GPP) estimates using atmospheric measurements of carbonyl sulfide (COS)

    NASA Astrophysics Data System (ADS)

    Chen, Huilin; Montzka, Steve; Andrews, Arlyn; Sweeney, Colm; Jacobson, Andy; Miller, Ben; Masarie, Ken; Jung, Martin; Gerbig, Christoph; Campbell, Elliott; Abu-Naser, Mohammad; Berry, Joe; Baker, Ian; Tans, Pieter

    2013-04-01

    Understanding the responses of gross primary production (GPP) to climate change is essential for improving our prediction of climate change. To this end, it is important to accurately partition net ecosystem exchange of carbon into GPP and respiration. Recent studies suggest that carbonyl sulfide is a useful tracer to provide a constraint on GPP, based on the fact that both COS and CO2 are simultaneously taken up by plants and the quantitative correlation between GPP and COS plant uptake. We will present an assessment of North American GPP estimates from the Simple Biosphere (SiB) model, the Carnegie-Ames-Stanford Approach (CASA) model, and the MPI-BGC model through atmospheric transport simulations of COS in a receptor oriented framework. The newly upgraded Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) will be employed to compute the influence functions, i.e. footprints, to link the surface fluxes to the concentration changes at the receptor observations. The HYSPLIT is driven by the 3-hourly archived NAM 12km meteorological data from NOAA NCEP. The background concentrations are calculated using empirical curtains along the west coast of North America that have been created by interpolating in time and space the observations at the NOAA/ESRL marine boundary layer stations and from aircraft vertical profiles. The plant uptake of COS is derived from GPP estimates of biospheric models. The soil uptake and anthropogenic emissions are from Kettle et al. 2002. In addition, we have developed a new soil flux map of COS based on observations of molecular hydrogen (H2), which shares a common soil uptake term but lacks a vegetative sink. We will also improve the GPP estimates by assimilating atmospheric observations of COS in the receptor oriented framework, and then present the assessment of the improved GPP estimates against variations of climate variables such as temperature and precipitation.

  16. Using NDACC column measurements of carbonyl sulfide to estimate its sources and sinks

    NASA Astrophysics Data System (ADS)

    Wang, Yuting; Marshall, Julia; Palm, Mathias; Deutscher, Nicholas; Roedenbeck, Christian; Warneke, Thorsten; Notholt, Justus; Baker, Ian; Berry, Joe; Suntharalingam, Parvadha; Jones, Nicholas; Mahieu, Emmanuel; Lejeune, Bernard; Hannigan, James; Conway, Stephanie; Strong, Kimberly; Campbell, Elliott; Wolf, Adam; Kremser, Stefanie

    2016-04-01

    Carbonyl sulfide (OCS) is taken up by plants during photosynthesis through a similar pathway as carbon dioxide (CO2), but is not emitted by respiration, and thus holds great promise as an additional constraint on the carbon cycle. It might act as a sort of tracer of photosynthesis, a way to separate gross primary productivity (GPP) from the net ecosystem exchange (NEE) that is typically derived from flux modeling. However the estimates of OCS sources and sinks still have significant uncertainties, which make it difficult to use OCS as a photosynthetic tracer, and the existing long-term surface-based measurements are sparse. The NDACC-IRWG measures the absorption of OCS in the atmosphere, and provides a potential long-term database of OCS total/partial columns, which can be used to evaluate OCS fluxes. We have retrieved OCS columns from several NDACC sites around the globe, and compared them to model simulation with OCS land fluxes based on the simple biosphere model (SiB). The disagreement between the measurements and the forward simulations indicates that (1) the OCS land fluxes from SiB are too low in the northern boreal region; (2) the ocean fluxes need to be optimized. A statistical linear flux model describing OCS is developed in the TM3 inversion system, and is used to estimate the OCS fluxes. We performed flux inversions using only NOAA OCS surface measurements as an observational constraint and with both surface and NDACC OCS column measurements, and assessed the differences. The posterior uncertainties of the inverted OCS fluxes decreased with the inclusion of NDACC data comparing to those using surface data only, and could be further reduced if more NDACC sites were included.

  17. Novel DNPH-based method for determination of protein carbonylation in muscle and meat.

    PubMed

    Soglia, Francesca; Petracci, Massimiliano; Ertbjerg, Per

    2016-04-15

    Protein oxidation is considered an ongoing deteriorative process during storage of fresh and processed meat. Carbonyl compounds have traditionally been detected spectrophotometrically after derivatization with 2,4-dinitrophenylhydrazine (DNPH) to form protein-bound hydrazones with absorbance at 370 nm. Here we describe a novel DNPH-based method to quantify protein carbonylation in muscle and meat. The additional steps of the novel method aimed at increasing the protein solubility and inducing protein unfolding before labeling with DNPH. Compared to the traditional method, the new procedure reflected an increased protein carbonylation level measuring overall two to fourfold more carbonyls in muscles from different species as well as in soluble, salt-soluble and insoluble protein fractions. The study suggested that protein unfolding is a more important phenomenon than solubilization for increased DNPH labeling. The novel method resulted in three to fourfold larger carbonyl content determined in chicken, pork and beef (2.8, 3.6 and 3.1 nmol/mg of protein, respectively). PMID:26617002

  18. Detection of Oxidative Stress-Induced Carbonylation in Live Mammalian Cells

    PubMed Central

    Mukherjee, Kamalika; Chio, Tak Ian; Sackett, Dan L.; Bane, Susan L.

    2015-01-01

    Oxidative stress is often associated with etiology and/or progression of disease conditions, such as cancer, neurodegenerative diseases, and diabetes. At the cellular level, oxidative stress induces carbonylation of biomolecules such as lipids, proteins and DNA. The presence of carbonylcontaining biomolecules as a hallmark of these diseases provides a suitable target for diagnostic detection. Here, a simple, robust method for detecting cellular aldehydes and ketones in live cells using a fluorophore is presented. A hydrazine-functionalized synthetic fluorophore serves as an efficient nucleophile that rapidly reacts with reactive carbonyls in the cellular milieu. The product thus formed exhibits a wavelength shift in the emission maximum accompanied by an increase in emission intensity. The photochemical characteristics of the fluorophore enable the identification of the fluorophore-conjugated cellular biomolecules in the presence of unreacted dye, eliminating the need for removal of excess fluorophore. Moreover, this fluorophore is found to be non-toxic and is thus appropriate for live cell analysis. Utility of the probe is demonstrated in two cell lines, PC3 and A549. Carbonylation resulting from serum starvation and hydrogen peroxide induced stress is detected in both cell lines using fluorescence microscopy and a fluorescence plate reader. The fluorescent signal originates from carbonylated proteins and lipids but not from oxidized DNA, and the majority of the fluorescence signal (>60%) is attributed to fluorophore-conjugated lipid oxidation products. This method should be useful for detecting cellular carbonylation in a high content assay or high throughput assay format. PMID:25801292

  19. Seasonal, diurnal and nocturnal behaviors of lower carbonyl compounds in the urban environment of Beirut, Lebanon

    NASA Astrophysics Data System (ADS)

    Moussa, Samar G.; El-Fadel, Mutassem; Saliba, Najat A.

    Lower carbonyl concentrations were measured for the first time in two different sampling sites (American University of Beirut (AUB) and Abdel-Aziz (AA)) in Beirut, Lebanon. Formaldehyde (C1) and acetaldehyde (C2) were the most abundant carbonyls with respective maximum concentrations of 12.2 and 5.2 ppbv at AUB and 8.6 and 5.1 ppbv at AA. Diurnal variations of carbonyls exhibited similar behaviors, suggesting related formation and decomposition routes. Morning levels of carbonyls were either equal or higher than the ones in the afternoon at the coastal site (AUB) due to atmospheric dilution. However, morning levels were mostly lower than noon levels at a three-busy street intersection (AA) due to the enhancement of photochemical activities. Vehicle emissions constituted the dominant source of carbonyls measured as confirmed by the good correlation between C1, C2 and propanal (C3) and the C1/CO and C2/CO ratios in the mornings. Seasonal variation showed the predominance of summertime photolysis and photo-oxidation reactions of aldehydes. Based on the measured formaldehyde levels, ozone and nitrous acid concentrations, morning and afternoon OH radical fluxes are computed and consequently their contribution to photochemical smog processes are assessed.

  20. Formation of carbonyl groups on cellulose during ozone treatment of pulp: consequences for pulp bleaching.

    PubMed

    Pouyet, Frédéric; Chirat, Christine; Potthast, Antje; Lachenal, Dominique

    2014-08-30

    The formation of carbonyl groups during the ozone treatment (Z) of eucalyptus (Eucalyptus grandis and Eucalyptus urophylla hybrid) kraft pulps and their behaviors during subsequent alkaline stages were investigated by the CCOA method with carbazole-9-carboxylic acid [2-(2-aminooxethoxy)-ethoxy] amide (CCOA) as the carbonyl-selective fluorescence label. Several pulp samples with or without lignin and hexenuronic acids (hexA) were used to elucidate the effects of these components when present in unbleached kraft pulp. Both hexA and lignin increased the formation of carbonyl groups on cellulose and hemicellulose during ozonation. It was concluded that radicals are likely formed when ozone reacts with either lignin or hexA. These carbonyl groups were involved in cellulose depolymerization during subsequent alkaline extraction stages with sodium hydroxide (E) and alkaline hydrogen peroxide (P, in ZEP or ZP). Their numbers decreased after E but increased during P when H2O2 was not stabilized enough. Several ways to minimize the occurrence of carbonyl group formation are suggested. PMID:24815405

  1. Ambient levels of atmospheric carbonyls in Beijing during the 2008 Olympic Games.

    PubMed

    Xu, Zhu; Liu, Junfeng; Zhang, Yujie; Liang, Peng; Mu, Yujing

    2010-01-01

    The measurements of atmospheric carbonyls concentrations in Beijing were conducted from 12 July to 8 October, 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. Six carbonyls, including formaldehyde, acetaldehyde, acetone, butyraldehyde, valeraldehyde, and hexaldehyde, were identified in all air samples. The total average concentrations of these carbonyls before, during, and after traffic restriction were (48.1 +/- 15.2), (36.6 +/- 14.5) and (23.4 +/- 12.3) microg/m3, respectively. Compared with the period after traffic restriction, the distinct high concentrations of the carbonyls before and during traffic restriction were primarily ascribed to the remarkable contribution of photochemical reactions. With respect to our previous investigation in the summer of 2005, the reductions of formaldehyde, acetaldehyde and acetone during traffic restriction period were about 64%, 47% and 27%, respectively, indicating that the air cleaning actions adopted by the Chinese government for the two games were efficient. The lowest levels of atmospheric carbonyls and the extremely high composition proportion of acetone after the traffic restriction were mainly attributed to the long-term effect of the control measures for the two games. PMID:21174965

  2. Fructose-Induced Carbonyl/Oxidative Stress in S. cerevisiae: Involvement of TOR.

    PubMed

    Valishkevych, Bohdana V; Vasylkovska, Ruslana A; Lozinska, Liudmyla M; Semchyshyn, Halyna M

    2016-01-01

    The TOR (target of rapamycin) signaling pathway first described in the budding yeast Saccharomyces cerevisiae is highly conserved in eukaryotes effector of cell growth, longevity, and stress response. TOR activation by nitrogen sources, in particular amino acids, is well studied; however its interplay with carbohydrates and carbonyl stress is poorly investigated. Fructose is a more potent glycoxidation agent capable of producing greater amounts of reactive carbonyl (RCS) and oxygen species (ROS) than glucose. The increased RCS/ROS production, as a result of glycoxidation in vivo, is supposed to be involved in carbonyl/oxidative stress, metabolic disorders, and lifespan shortening of eukaryotes. In this work we aim to expand our understanding of how TOR is involved in carbonyl/oxidative stress caused by reducing monosaccharides. It was found that in fructose-grown compared with glucose-grown cells the level of carbonyl/oxidative stress markers was higher. The defects in the TOR pathway inhibited metabolic rate and suppressed generation of glycoxidation products in fructose-grown yeast. PMID:27019749

  3. Fructose-Induced Carbonyl/Oxidative Stress in S. cerevisiae: Involvement of TOR

    PubMed Central

    Valishkevych, Bohdana V.; Vasylkovska, Ruslana A.; Lozinska, Liudmyla M.; Semchyshyn, Halyna M.

    2016-01-01

    The TOR (target of rapamycin) signaling pathway first described in the budding yeast Saccharomyces cerevisiae is highly conserved in eukaryotes effector of cell growth, longevity, and stress response. TOR activation by nitrogen sources, in particular amino acids, is well studied; however its interplay with carbohydrates and carbonyl stress is poorly investigated. Fructose is a more potent glycoxidation agent capable of producing greater amounts of reactive carbonyl (RCS) and oxygen species (ROS) than glucose. The increased RCS/ROS production, as a result of glycoxidation in vivo, is supposed to be involved in carbonyl/oxidative stress, metabolic disorders, and lifespan shortening of eukaryotes. In this work we aim to expand our understanding of how TOR is involved in carbonyl/oxidative stress caused by reducing monosaccharides. It was found that in fructose-grown compared with glucose-grown cells the level of carbonyl/oxidative stress markers was higher. The defects in the TOR pathway inhibited metabolic rate and suppressed generation of glycoxidation products in fructose-grown yeast. PMID:27019749

  4. Probing the Carbonyl Functionality of a Petroleum Resin and Asphaltene through Oximation and Schiff Base Formation in Conjunction with N-15 NMR.

    PubMed

    Thorn, Kevin A; Cox, Larry G

    2015-01-01

    Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected. PMID:26556054

  5. Probing the carbonyl functionality of a petroleum resin and asphaltene through oximation and schiff base formation in conjunction with N-15 NMR

    USGS Publications Warehouse

    Thorn, Kevin A.; Cox, Larry G.

    2015-01-01

    Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected.

  6. Probing the Carbonyl Functionality of a Petroleum Resin and Asphaltene through Oximation and Schiff Base Formation in Conjunction with N-15 NMR

    PubMed Central

    Thorn, Kevin A.; Cox, Larry G.

    2015-01-01

    Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (NMR) spectra of asphaltenes and resins and therefore require spin labeling techniques for detection. In this study, the carbonyl functionalities of the resin and asphaltene fractions from a light aliphatic crude oil that is the source of groundwater contamination at the long term USGS study site near Bemidji, Minnesota, have been examined through reaction with 15N-labeled hydroxylamine and aniline in conjunction with analysis by solid and liquid state 15N NMR. Ketone groups were revealed through 15N NMR detection of their oxime and Schiff base derivatives, and esters through their hydroxamic acid derivatives. Anilinohydroquinone adducts provided evidence for quinones. Some possible configurations of the ketone groups in the resin and asphaltene fractions can be inferred from a consideration of the likely reactions that lead to heterocyclic condensation products with aniline and to the Beckmann reaction products from the initially formed oximes. These include aromatic ketones and ketones adjacent to quaternary carbon centers, β-hydroxyketones, β-diketones, and β-ketoesters. In a solid state cross polarization/magic angle spinning (CP/MAS) 15N NMR spectrum recorded on the underivatized asphaltene as a control, carbazole and pyrrole-like nitrogens were the major naturally abundant nitrogens detected. PMID:26556054

  7. Metal carbonyl-hydrosilane reactions and hydrosilation catalysis. Final report for period May 1, 1995 - August 14, 1999

    SciTech Connect

    Cutler, Alan R.

    2001-04-14

    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a doxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(CO){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(l) precatalysts. The reaction chemistry of the above and other Mn alkyl complexes with hydrosilanes was studied in order to probe catalysis mechanism(s). Thus, Mn(CO){sub 5} methyl, benzyl, acetyl, and benzoyl (4 p-substituents) complexes reacted with hydrosilines by four different mechanisms, which were established. A noteworthy development was that the methyl and benzoyl complexes gave moderate yields of a new ({eta}{sup 2}-Si-H) silane adduct (CO){sub 4}Mn(SiMe{sub 2}Ph)(H-SiMe{sub 2}Ph), which is stable in the presence of excess silane. This silane adduct promotes all three catalytic reactions; its extraordinary activity and potential selectivity are under study.

  8. Anionic group 6B metal carbonyls as homogeneous catalysts for carbon dioxide/hydrogen activation: the production of alkyl formates

    SciTech Connect

    Darensbourg, D.J.; Ovalles, C.

    1984-06-27

    The production of alkyl formates from the hydrocondensation of carbon dioxide in alcohols utilizing anionic group 6B carbonyl hydrides as catalysts is herein reported. HM(CO)/sub 5//sup -/ (M = Cr, W; derived from ..mu..-H(M/sub 2/(CO)/sub 10/)/sup -/) and their products of carbon dioxide insertion, HCO/sub 2/M(CO)/sub 5//sup -/, have been found to be effective catalysts for the hydrogenation of CO/sub 2/ in alcohols under rather mild conditions (loading pressures of CO/sub 2/ and H/sub 2/, 250 psi each, and 125/sup 0/C) to provide alkyl formates. The only metal carbonyl species detected in solution via spectroscopy, both at the end of a catalytic period and during catalysis, were M(CO)/sub 6/ and HCO/sub 2/M(CO)/sub 5//sup -/. The metal hexacarbonyls were independently shown to be catalytically inactive. A catalytic cycle is proposed which initially involves release of formic acid from the metal center, either by reductive elimination of the hydrido formato ligands or ligand-assisted heterolytic splitting of dihydrogen with loss of formic acid. In a rapid subsequent process HCOOH reacts with alcohols to yield HCOOR. The addition of carbon monoxide retards alkyl formate production, strongly implying CO/sub 2/ to be the primary source of the carboxylic carbon atom in HCOOR. This was verified by carrying out reactions in the presence of HCO/sub 2/W(/sup 13/CO)/sub 5//sup -/ which provided only H/sup 12/COOR after short reaction periods. However, in the absence of hydrogen and carbon dioxide ..mu..-H(M/sub 2/(CO)/sub 10/)/sup -/ species were observed to be effective catalyst precursors for converting CO and methanol into methyl formate. 36 references, 2 figures, 2 tables.

  9. A Carbonylation Approach Toward Activation of Csp2-H and Csp3-H Bonds: Cu-Catalyzed Regioselective Cross Coupling of Imidazo[1,2-a]pyridines with Methyl Hetarenes.

    PubMed

    Lei, Sai; Mai, Yingying; Yan, Caijuan; Mao, Jianwen; Cao, Hua

    2016-08-01

    An efficient copper-catalyzed selective cross coupling of imidazo[1,2-a]pyridines with methyl hetarenes has been reported. This transformation opened a new route to synthesize the C-3 carbonyl imidazo[1,2-a]pyridine derivative, which is a common structural motif in natural products and pharmaceuticals. (18)O-labeling experiments indicated that the oxygen source of products originated from O2. PMID:27388919

  10. Mechanistic differences between methanol and dimethyl ether carbonylation in side pockets and large channels of mordenite.

    PubMed

    Boronat, Mercedes; Martínez, Cristina; Corma, Avelino

    2011-02-21

    The activity and selectivity towards carbonylation presented by Brønsted acid sites located inside the 8MR pockets or in the main 12MR channels of mordenite is studied by means of quantum-chemical calculations, and the mechanistic differences between methanol and DME carbonylation are investigated. The selectivity towards carbonylation is higher inside the 8MR pockets, where the competitive formation of DME and hydrocarbons that finally leads to catalyst deactivation is sterically impeded. Moreover, inclusion of dispersion interactions in the calculations leads to agreement between the calculated activation barriers for the rate determining step and the experimentally observed higher reactivity of methoxy groups located inside the 8MR channels. PMID:21249237

  11. Effect of carbonyl iron particles composition on the physical characteristics of MR grease

    NASA Astrophysics Data System (ADS)

    Mohamad, Norzilawati; Mazlan, Saiful Amri; Ubaidillah

    2016-03-01

    Magnetorheological (MR) grease is an extension of the study of magnetorheological materials. The MR grease can help to reduce the particles sedimentation problem occurred in the MR fluids. Within this study, an effort has been taken to investigate the effect of different weight compositions of carbonyl iron particles on the physical and chemical characteristics of the MR grease under off-state condition (no magnetic field). The MR grease is prepared by mixing carbonyl iron particles having a size range of 1 to 10 µm with commercial NPC Highrex HD-3 grease. Characterizations of MR grease are investigated using Vibrating Sample Magnetometer (VSM), Environmental Scanning Electron Microscopy (ESEM), Differential Scanning Calorimeter (DSC) and rheometer. The dependency of carbonyl iron particles weight towards the magnetic properties of MR grease and other characterizations are investigated.

  12. Relevance, Derogation and Permission

    NASA Astrophysics Data System (ADS)

    Stolpe, Audun

    We show that a recently developed theory of positive permission based on the notion of derogation is hampered by a triviality result that indicates a problem with the underlying full-meet contraction operation. We suggest a solution that presupposes a particular normal form for codes of norms, adapted from the theory of relevance through propositional letter sharing. We then establish a correspondence between contractions on sets of norms in input/output logic (derogations), and AGM-style contractions on sets of formulae, and use it as a bridge to migrate results on propositional relevance from the latter to the former idiom. Changing the concept accordingly we show that positive permission now incorporates a relevance requirement that wards off triviality.

  13. Total Synthesis of Tetrahydrolipstatin and Stereoisomers via a Highly Regio- and Diastereoselective Carbonylation of Epoxyhomoallylic Alcohols

    PubMed Central

    2015-01-01

    A concise enantioselective synthesis of tetrahydrolipstatin (THL) and seven stereoisomers has been achieved. The synthesis of THL was accomplished in 10 steps and 31% overall yield from an achiral ynone. Key to the success of the approach is the use of a bimetallic [Lewis acid]+[Co(CO)4]− catalyst for a late-stage regioselective carbonylation of an enantiomerically pure cis-epoxide to a trans-β-lactone. The success of this route to THL and its stereoisomers also demonstrated the practicality of the carbonylation catalyst for complex molecule synthesis as well as its functional group compatibility. PMID:25004122

  14. Activation of Carbonyl-Containing Molecules with Solid Lewis Acids in Aqueous Media

    SciTech Connect

    Román-Leshkov, Yuriy; Davis, Mark E.

    2011-09-28

    Current interest in reacting carbonyl-containing molecules in aqueous media is primarily due to the growing emphasis on conversion of biomass to fuels and chemicals. Recently, solid Lewis acids have been shown to perform catalytic reactions with carbonyl-containing molecules such as sugars in aqueous media. Here, catalysis mediated by Lewis acids is briefly discussed, Lewis acid solids that perform catalysis in aqueous media are then described, and the review is concluded with a few comments on the outlook for the future.

  15. Synthesis of diversely substituted 2-(furan-3-yl)acetates from allenols through cascade carbonylations.

    PubMed

    He, Yan; Zhang, Xinying; Fan, Xuesen

    2015-11-21

    Novel synthesis of diversely substituted 2-(furan-3-yl)acetates via palladium-catalyzed one-pot multi-component reactions of allenols, aryl iodides, alcohols, and carbon monoxide has been developed. Notably, the formation of the title compounds features a cascade process combining carbonylation of aryl iodide, alcohoxyl carbonylation of the in situ formed allyl palladium complex, and intramolecular condensation of the α-hydroxyl enone intermediate. Moreover, the 2-(furan-3-yl)acetates obtained herein were found to be ready intermediates for the construction of the biologically significant naphtho[1,2-b]furan-5-ol scaffold. PMID:26399394

  16. Construction of copper halide-triiron selenide carbonyl complexes: synthetic, electrochemical, and theoretical studies.

    PubMed

    Shieh, Minghuey; Miu, Chia-Yeh; Lee, Chang-Ju; Chen, Wei-Cheng; Chu, Yen-Yi; Chen, Hui-Lung

    2008-12-01

    A new family of CuX-, Cu(2)X(2)-, and Cu(4)X(2)-incorporated mono- or di-SeFe(3)-based carbonyl clusters were constructed and structurally characterized. When the selenium-capped triiron carbonyl cluster [Et(4)N](2)[SeFe(3)(CO)(9)] was treated with 1-3 equiv of CuX in tetrahydrofuran (THF) at low or room temperatures, CuX-incorporated SeFe(3) complexes [Et(4)N](2)[SeFe(3)(CO)(9)CuX] (X = Cl, [Et(4)N](2)[1a]; Br, [Et(4)N](2)[1b]; I, [Et(4)N](2)[1c]), Cu(2)X(2)-incorporated SeFe(3) clusters [Et(4)N](2)[SeFe(3)(CO)(9)Cu(2)X(2)] (X = Cl, [Et(4)N](2)[2a]; Br, [Et(4)N](2)[2b]), and Cu(4)X(2)-linked di-SeFe(3) clusters [Et(4)N](2)[{SeFe(3)(CO)(9)}(2)Cu(4)X(2)] (X = Cl, [Et(4)N](2)[3a]; Br, [PPh(4)](2)[3b]) were obtained, respectively, in good yields. SeFe(3)CuX complexes 1a and 1b were found to undergo cluster expansion to form SeFe(3)Cu(2)X(2) complexes 2a and 2b, respectively, upon the addition of 1 equiv of CuX (X = Cl, Br). Furthermore, complexes 2a and 2b can expand further to form Cu(4)X(2)-linked di-SeFe(3) clusters 3a and 3b, upon treatment with 1 equiv of CuX (X = Cl, Br). [Et(4)N](4)[{SeFe(3)(CO)(9)(CuCl)(2)}(2)] ([Et(4)N](4)[4a]) was produced when the reaction of [Et(4)N](2)[SeFe(3)(CO)(9)] with 2 equiv of CuCl was conducted in THF at 40 degrees C. The Cu(2)Cl(2)-linked di-SeFe(3)CuCl cluster 4a is a dimerization product derived from complex 2a. Further, it is found that complex 4a can convert to the Cu(4)Cl(2)-linked di-SeFe(3) cluster 3a upon treatment with CuCl. The nature, formation, stepwise cluster expansion, and electrochemical properties of these CuX-, Cu(2)X(2)-, and Cu(4)X(2)-incorporated mono- or di-SeFe(3)-based clusters are elucidated in detail by molecular calculations at the B3LYP level of the density functional theory in terms of the effects of selenium, iron, copper halides, and the size of the metal skeleton. PMID:19228023

  17. Blending Rigor and Relevance

    ERIC Educational Resources Information Center

    Siri, Diane K.; Zinner, Jane; Lezin, Nicole

    2011-01-01

    A collaborative at several sites across the state of California will offer evidence of how successful linked learning, which connects academics to real-world work, can be. This article presents examples that illustrate the powerful connections and linkages that are generated by combining academic rigor with the relevance of applying learning to…

  18. Is Information Still Relevant?

    ERIC Educational Resources Information Center

    Ma, Lia

    2013-01-01

    Introduction: The term "information" in information science does not share the characteristics of those of a nomenclature: it does not bear a generally accepted definition and it does not serve as the bases and assumptions for research studies. As the data deluge has arrived, is the concept of information still relevant for information…

  19. The Relevance of Literature.

    ERIC Educational Resources Information Center

    Dunham, L. L.

    1971-01-01

    The "legacy" of the humanities is discussed in terms of relevance, involvement, and other philosophical considerations. Reasons for studying foreign literature in language classes are developed in the article. Comment is also made on attitudes and ideas culled from the writings of Clifton Fadiman, Jean Paul Sartre, and James Baldwin. (RL)

  20. Reading, Writing and Relevance.

    ERIC Educational Resources Information Center

    Hoffman, Mary

    This monograph presents classroom activities that were designed to encourage children to read and write in a self-reliant and responsible manner. The activities were chosen for their relevance to the children involved and because the vocabulary involved was interesting, familiar, and worth remembering and using again. The topics are arranged in…

  1. Breast- and salivary gland-derived adenoid cystic carcinomas: potential post-transcriptional divergencies. A pilot study based on miRNA expression profiling of four cases and review of the potential relevance of the findings.

    PubMed

    Kiss, Orsolya; Tőkés, Anna-Mária; Spisák, Sándor; Szilágyi, Anna; Lippai, Norbert; Székely, Borbála; Szász, A Marcell; Kulka, Janina

    2015-01-01

    Adenoid cystic carcinoma (ACC) is a malignant tumor of the salivary glands but identical tumors can also arise from the breast. Despite their similar histomorphological appearance the salivary gland- and the breast-derived forms differ in their clinical features: while ACC of the salivary glands (sACC) have an aggressive clinical course, the breast-derived form (bACC) shows a very favourable clinical outcome. To date no exact molecular alterations have yet been identified which would explain the diverse clinical features of the ACCs of different origin. In our pilot experiment we investigated the post-transcriptional features of ACC cases by performing microRNA-profiling on 2-2 bACC and sACC tissues and on 1-1 normal breast and salivary gland tissue. By comparing the microRNA-profiles of the investigated samples we identified microRNAs which were expressed differently in bACC and sACC cases according to their normal controls: 7 microRNAs were overexpressed in sACC cases and downexpressed in bACC tumors (let-7b, let-7c, miR-17, miR-20a, miR-24, miR-195, miR-768-3) while 9 microRNAs were downexpressed in sACC cases and overexpressed in bACC tissues (let-7e, miR-23b, miR-27b, miR-193b, miR-320a, miR-320c, miR-768-5p, miR-1280 and miR-1826) relative to their controls. We also identified 8 microRNAs which were only expressed in sACCs and one microRNA (miR-1234) which was only absent in sACC cases. By target predictor online databases potential targets of the these microRNAs were detected to identify genes that may play central role in the diverse clinical outcome of bACC and sACC cases. PMID:25240490

  2. Synthesis of 3,3'-carbonyl-bis(chromones) and their activity as mammalian alkaline phosphatase inhibitors.

    PubMed

    Miliutina, Mariia; Ejaz, Syeda Abida; Iaroshenko, Viktor O; Villinger, Alexander; Iqbal, Jamshed; Langer, Peter

    2016-01-14

    Hitherto unknown 3,3'-carbonyl-bis(chromones) 8, dimeric chromones bridged by a carbonyl group, were prepared by reaction of chromone-3-carboxylic acid chloride with 3-(dimethylamino)-1- (2-hydroxyphenyl)-2-propen-1-ones 9. The method is generally applicable for the synthesis of novel symmetrical or non-symmetrical products which were found to inhibit mammalian alkaline phosphatases. PMID:26490672

  3. Tandem semi-hydrogenation/isomerization of propargyl alcohols to saturated carbonyl analogues by dodecanethiolate-capped palladium nanoparticle catalysts†

    PubMed Central

    Gavia, Diego J.; Koeppen, Jordan; Sadeghmoghaddam, Elham; Shon, Young-Seok

    2016-01-01

    The efficient one-pot conversion of propargyl alcohols to their saturated carbonyl analogues is carried out for the first time using metal nanoparticle catalysts, dodecanethiolate-capped Pd nanoparticles. Kinetic studies reveal that the reaction progresses through a semi-hydrogenation intermediate (allyl alcohols) followed by isomerization to carbonyls.

  4. DEVELOPMENT AND APPLICATION OF A SENSITIVE METHOD TO DETERMINE CONCENTRATIONS OF ACROLEIN AND OTHER CARBONYLS IN AMBIENT AIR

    EPA Science Inventory

    The sampler developed by Charles and Cahill, with Dr. Vincent Seaman, consists of a custom-built glass mist chamber in which air enters at a high flow rate and carbonyls are trapped in a solution of sodium bisulfite as carbonyl-bisulfite adducts. This reaction is rapid (on ...

  5. Enhancement effects of ultrasound assisted in the synthesis of NiAl hydrotalcite for carbonyl sulfide removal.

    PubMed

    Zhao, Shunzheng; Yi, Honghong; Tang, Xiaolong; Gao, Fengyu; Yu, Qingjun; Zhou, Yuansong; Wang, Jiangen; Huang, Yonghai; Yang, Zhongyu

    2016-09-01

    Ultrasonic effect in the synthesis of catalysts of NiAl oxides prepared starting from the coprecipitation method of a hydrotalcite structure was evaluated in this work. Removal of carbonyl sulfide (COS) at low temperature over the hydrotalcite-derived oxides was studied. The samples were characterized by X-ray Diffraction (XRD), scanning electron microscope (SEM), N2 adsorption/desorption techniques, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and CO2 temperature-programmed desorption (TPD). It is found that hydrotalcite treated with ultrasonic has smaller average crystallite size and higher particle dispersion compared to hydrotalcite without ultrasonic treatment. As a result, mixed oxides derived from hydrotalcite treated with ultrasonic show more developed pore structure which is good for the physical adsorption of gaseous pollutant. The result of desulfuration test showed that removal efficiency of COS on the NiAl mixed oxides prepared by ultrasonic method (30min) is greater than that on the catalyst prepared without the ultrasonic irradiation assistance with the same aging time. One important reason for the high activity is that when the ultrasonic is used the number of weak basic sites (OH(-) groups) and moderate basic sites (M-O) was increased, whereas the number of strong basic sites (O(2-)) was decreased. Therefore, ultrasonic treatment promoted the COS hydrolysis and suppress the poisoning of the catalyst. PMID:27150779

  6. Synthesis of an Epoxide Carbonylation Catalyst: Exploration of Contemporary Chemistry for Advanced Undergraduates

    ERIC Educational Resources Information Center

    Getzler, Yutan D. Y. L.; Schmidt, Joseph A. R.; Coates, Geoffrey W.

    2005-01-01

    A class of highly active, well-defined compounds for the catalytic carbonylation of epoxides and aziridines to beta-lactones and beta-lactams are introduced. The synthesis of one of the catalysts involves a simple imine condensation to form the ligand followed by air-sensitive metalation and salt metathesis steps.

  7. Palladium-catalyzed carbonylative synthesis of quinazolinones from 2-aminobenzamide and aryl bromides.

    PubMed

    Wu, Xiao-Feng; He, Lin; Neumann, Helfried; Beller, Matthias

    2013-09-16

    C from CO! A straightforward procedure for the carbonylative synthesis of quinazolinones from readily available 2-aminobenzamide and aryl bromides has been developed. In the presence of a palladium catalyst, various quinazolinones were produced in moderate to excellent yields. Remarkably, no chromatography was needed for purification (see scheme). PMID:24175339

  8. HYDROGENATION OF UNSATURATED CARBONYLS IN SCCO2 AS REACTION MEDIUM OVER NI-SUPPORTED CATALYSTS

    EPA Science Inventory

    Selective hydrogenation of a, a unsaturated carbonyls where molecules containing C=C and C=O double bonds has both practical importance for fine chemicals industry and theoretical significance. Various studies are reported to enhance the selective hydrogenation of C=O over group...

  9. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    EPA Science Inventory

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  10. α-Regioselective Barbier Reaction of Carbonyl Compounds and Allyl Halides Mediated by Praseodymium.

    PubMed

    Wu, San; Li, Ying; Zhang, Songlin

    2016-09-01

    The first utility of praseodymium as a mediating metal in the Barbier reaction of carbonyl compounds with allyl halides was reported in this paper. In contrast to the traditional metal-mediated or catalyzed Barbier reactions, exclusive α-adducts were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions. PMID:27490708

  11. 40 CFR 721.1620 - Benzenesulfonamide, alkylphenyl substituted phenyl substituted carbonyl- (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phenyl substituted carbonyl- (PMN P-00-368) is subject to reporting under this section for the... in § 721.125(a), (b), (c), (d), (f), (g), (h), and (k) are applicable to manufacturers, importers... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF...

  12. 40 CFR 721.1620 - Benzenesulfonamide, alkylphenyl substituted phenyl substituted carbonyl- (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... phenyl substituted carbonyl- (PMN P-00-368) is subject to reporting under this section for the... in § 721.125(a), (b), (c), (d), (f), (g), (h), and (k) are applicable to manufacturers, importers... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF...

  13. 40 CFR 721.1620 - Benzenesulfonamide, alkylphenyl substituted phenyl substituted carbonyl- (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... phenyl substituted carbonyl- (PMN P-00-368) is subject to reporting under this section for the... in § 721.125(a), (b), (c), (d), (f), (g), (h), and (k) are applicable to manufacturers, importers... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF...

  14. 40 CFR 721.1620 - Benzenesulfonamide, alkylphenyl substituted phenyl substituted carbonyl- (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... phenyl substituted carbonyl- (PMN P-00-368) is subject to reporting under this section for the... in § 721.125(a), (b), (c), (d), (f), (g), (h), and (k) are applicable to manufacturers, importers... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF...

  15. Carbonyl clusters of transition metals on oxide supports as heterogeneous catalysts for hydrocarbon synthesis

    SciTech Connect

    Kuznetsov, B.N.; Koval`chuk, V.I.

    1995-05-01

    The methods of preparation of heterogeneous catalysts by immobilization of carbonyl clusters of transition metals on oxide supports, as well as the study of the state of supported compounds and their catalytic properties in CO hydrogenation and olefin hydroformulation are briefly reviewed.

  16. [Determination of major carbonyls in mainstream smoke by rapid column high performance liquid chromatography].

    PubMed

    Huang, Yun; Wang, Yigeng; Miao, Mingming; Zhao, Qihua; Yang, Guangyu

    2007-03-01

    Abstract: The determination of major carbonyl compounds in mainstream cigarette smoke by rapid column high performance liquid chromatography was investigated. The cigarette smoke was collected using a Cambridge filter treated with acidic solution of 2, 4-dinitrophenyl-hydrazine. Formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, 2-butanone and butyraldehyde were extracted from the Cambridge filter with 50 mL of 2% pyridine acetonitrile solution. The carbonyl compounds in samples were separated on a ZORBAX Stable Bound rapid column (50 mm x 4. 6 mm, 1. 8 microm) in approximately seven minutes and then determined by high performance liquid chromatography with a diode array detector. The average recoveries were in the range of 89. 1% to 99. 2% and the relative standard deviations (RSDs) were generally below 6. 0%. The eight carbonyl compounds in the mainstream smoke of five brands of cigarettes were determined using this method. This method is faster, simpler and consumes less solvent. It is suitable for rapid analysis of carbonyl compounds in mainstream cigarette smoke. PMID:17580693

  17. Formation of phenol under conditions of the reaction of oxidative carbonylation of benzene to benzoic acid

    SciTech Connect

    Kalinovsky, I.O.; Leshcheva, A.N.; Pogorelov, V.V.; Gelbshtein, A.I.

    1993-12-31

    This paper describes conditions for the oxidation of benzene to phenol. It is shown that a reaction mixture of water, carbon monoxide, and oxygen are essential to the oxidation. The oxidation is a side reaction found to occur during the oxidative carbonylation of benzene to benzoic acid in a medium of trifluoroacetic acid.

  18. Trends of ambient carbonyl compounds in the urban environment of Hong Kong

    NASA Astrophysics Data System (ADS)

    Sin, Della W. M.; Wong, Yiu-Chung; Louie, Peter K. K.

    The concentrations of C 1-C 8 carbonyl compounds were measured at two urban sites in Hong Kong from October 1997 to September 2000. The daily total carbonyl concentrations were found to range from 2.4 to 37 μg m -3. Formaldehyde was the most abundant species, which comprised from 36 to 43% of the total detected carbonyls, followed by acetaldehyde (18-21%) and acetone (8-20%). The highest 24-hour average concentrations measured were 10 and 7.7 μg m -3 for formaldehyde and acetaldehyde, respectively. Seasonal and temporal variations in the concentrations of formaldehyde and acetaldehyde were not obvious, but lowest concentrations often occurred from June to August. The mean formaldehyde/acetaldehyde molar ratios at the two sites in summer (2.8±1.1 and 2.5±1.2) were significantly higher ( p⩽0.01) than those in winter periods (1.9±0.6 and 2.0±0.6). The phenomena were explained by influences of both photochemical reactions and local meteorological conditions. Better correlations between formaldehyde and acetaldehyde, and between NO x and each of the two major carbonyls were obtained in winter periods indicating direct vehicular emissions were the principal sources. The ambient formaldehyde and acetaldehyde concentrations in the urban atmosphere of Hong Kong were within the normal ranges reported in the literature for other urban sites world-wide.

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

    EPA Science Inventory

    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...

  20. Specificity of sites within eight-membered ring zeolite channels for carbonylation of methyls to acetyls.

    PubMed

    Bhan, Aditya; Allian, Ayman D; Sunley, Glenn J; Law, David J; Iglesia, Enrique

    2007-04-25

    The acid-catalyzed formation of carbon-carbon bonds from C1 precursors via CO insertion into chemisorbed methyl groups occurs selectively within eight-membered ring (8-MR) zeolite channels. This elementary step controls catalytic carbonylation rates of dimethyl ether (DME) to methyl acetate. The number of O-H groups within 8-MR channels was measured by rigorous deconvolution of the infrared bands for O-H groups in cation-exchanged and acid forms of mordenite (M,H-MOR) and ferrierite (H-FER) after adsorption of basic probe molecules of varying size. DME carbonylation rates are proportional to the number of O-H groups within 8-MR channels. Na+ cations selectively replaced protons within 8-MR channels and led to a disproportionate decrease in carbonylation turnover rates (per total H+). These conclusions are consistent with the low or undetectable rates of carbonylation on zeolites without 8-MR channels (H-BEA, H-FAU, H-MFI). Such specificity of methyl reactivity upon confinement within small channels appears to be unprecedented in catalysis by microporous solids, which typically select reactions by size exclusion of bulkier transition states. PMID:17397162

  1. NEUROTOXICITY OF CARBONYL SULFIDE IN F344 RATS FOLLOWING INHALATION EXPOSURE FOR UP TO 12 WEEKS.

    EPA Science Inventory

    Carbonyl sulfide (COS) was nominated to the National Toxicology Program for testing in 1996 due to emissions levels and a lack of data. Through an inter-agency collaboration, functional and electrophysiological endpoints were included in the studies. This manuscript describes b...

  2. Modeling Vibrational Spectra of Ester Carbonyl Stretch in Water and DMSO Based on Molecular Dynamics Simulation.

    PubMed

    Fang, Bin; Wang, Tianjun; Chen, Xian; Jin, Tan; Zhang, Ruiting; Zhuang, Wei

    2015-09-24

    On the basis of molecular dynamics simulation, we model the ester carbonyl stretch FTIR signals of methyl acetate in D2O and DMSO. An ab initio map is constructed at the B3LYP/6-311++G** level to relate the carbonyl stretch frequency to the external electric field. Using this map, fluctuating Hamiltonian of the carbonyl stretch is constructed from the MD simulation trajectory. The IR spectra calculated based on this Hamiltonian are found to be in good agreement with the experiment. For methyl acetate in D2O, hydrogen bonding on alkoxy oxygen causes a blue shift of frequency, while that on carbonyl oxygen causes a red shift. Two peaks observed in FTIR signals originate from the balance of these two effects. Furthermore, in both D2O and DMSO solutions, correlations are found between the instantaneous electric field on C═O and the frequencies. Broader line width of the signal in D2O suggests a more inhomogeneous electric field distribution due to the complicated hydrogen-bonding environment. PMID:26335032

  3. Proteomic and Carbonylation Profile Analysis of Rat Skeletal Muscles following Acute Swimming Exercise

    PubMed Central

    Pietrovito, Laura; Fiaschi, Tania; Bini, Luca; Esposito, Fabio; Marini, Marina; Abruzzo, Provvidenza Maria; Gulisano, Massimo; Modesti, Alessandra

    2013-01-01

    Previous studies by us and other groups characterized protein expression variation following long-term moderate training, whereas the effects of single bursts of exercise are less known. Making use of a proteomic approach, we investigated the effects of acute swimming exercise (ASE) on protein expression and carbonylation patterns in two hind limb muscles: the Extensor Digitorum Longus (EDL) and the Soleus, mostly composed of fast-twitch and slow-twitch fibres, respectively. Carbonylation is one of the most common oxidative modifications of proteins and a marker of oxidative stress. In fact, several studies suggest that physical activity and the consequent increase in oxygen consumption can lead to increase in reactive oxygen and nitrogen species (RONS) production, hence the interest in examining the impact of RONS on skeletal muscle proteins following ASE. Results indicate that protein expression is unaffected by ASE in both muscle types. Unexpectedly, the protein carbonylation level was reduced following ASE. In particular, the analysis found 31 and 5 spots, in Soleus and EDL muscles respectively, whose carbonylation is reduced after ASE. Lipid peroxidation levels in Soleus were markedly reduced as well. Most of the decarbonylated proteins are involved either in the regulation of muscle contractions or in the regulation of energy metabolism. A number of hypotheses may be advanced to account for such results, which will be addressed in future studies. PMID:23967250

  4. Mechanisms of the Water-Gas Shift Reaction Catalyzed by Ruthenium Carbonyl Complexes.

    PubMed

    Liu, Naying; Guo, Ling; Cao, Zhaoru; Li, Wenli; Zheng, Xiaoli; Shi, Yayin; Guo, Juan; Xi, Yaru

    2016-04-21

    Density functional theory (DFT) is employed to study the water-gas shift (WGS) reaction in the gas phase for two complexes, Ru3(CO)12 and Ru(CO)5. Here we report four mechanisms of ruthenium carbonyl complexes catalyzed for WGS reaction. The energetic span model is applied to evaluate efficiency of the four catalytic pathways. Our results indicate that mechanism C and D show a good catalytic behavior, which is in agreement with results from the literature. The mechanism C and D not only include the important intermediate Ru3(CO)11H(-) but also exclude the energy-demanding OH(-) desorption and revise an unfavorable factor of the previous mechanism. Two complexes along mechanisms B have the highest turnover frequency (TOF) values. The trinuclear carbonyl complexes-Ru3(CO)12 is preferred over mononuclear carbonyl Ru(CO)5 by comparing TOF due to the fact that metal-metal cooperativity can enhance activity to the WGS reaction. In this work, the nature of interaction between transition states and intermediates is also analyzed by the detailed electronic densities of states, and we further clarify high catalytic activity of ruthenium carbonyl complexes as well. Our conclusions provide a guide to design catalysts for the WGS reaction. PMID:27064302

  5. The Potential of Carbonyl Sulfide as a Tracer for Gross Primary Productivity at Flux Tower Sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regional/continental scale studies of atmospheric carbonyl sulfide (OCS) seasonal dynamics and leaf level studies of plant OCS uptake have shown a close relationship to CO2 dynamics and uptake, suggesting potential for OCS as a tracer for gross primary productivity (GPP). Canopy CO2 and OCS differen...

  6. The Potential of Carbonyl Sulfide as a Proxy for Gross Primary Production at Flux Tower Sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regional and continental scale studies of the seasonal dynamics of atmospheric carbonyl sulfide (OCS) mole fractions and leaf-level studies of plant OCS exchange have shown a close relationship with those for CO2. CO2 has sinks and sources within terrestrial ecosystems, but the primary terrestrial e...

  7. Iron Dextran treatment does not induce serum protein carbonyls in the newborn pig

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidation of serum proteins can lead to carbonyl formation which alters their function and is often associated with stress-related diseases. Since it is recommended that all pigs reared in modern production facilities be given supplemental iron at birth to prevent anemia, and metals can catalyze th...

  8. Towards a General Understanding of Carbonyl-Stabilised Ammonium Ylide-Mediated Epoxidation Reactions.

    PubMed

    Novacek, Johanna; Roiser, Lukas; Zielke, Katharina; Robiette, Raphaël; Waser, Mario

    2016-08-01

    The key factors for carbonyl-stabilised ammonium ylide-mediated epoxidation reactions were systematically investigated by experimental and computational means and the hereby obtained energy profiles provide explanations for the observed experimental results. In addition, we were able to identify the first tertiary amine-based chiral auxiliary that allows for high enantioselectivities and high yields for such epoxidation reactions. PMID:27381752

  9. Anisotropic thermal motion in transition-metal carbonyls from experiments and ab initio theory.

    PubMed

    Deringer, Volker L; Wang, Ai; George, Janine; Dronskowski, Richard; Englert, Ulli

    2016-09-21

    The thermal motion of atoms in crystals is quantified by anisotropic displacement parameters (ADPs). Here we show that dispersion-corrected periodic density-functional theory can be used to compute accurate ADPs for transition metal carbonyls, which serve as model systems for crystalline organometallic and coordination compounds. PMID:27513896

  10. Heterogeneous Chemistry of Carbonyls and Alcohols With Sulfuric Acid: Implications for Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Levitt, N.; Zhang, R.

    2006-12-01

    Recent environmental chamber studies have suggested that acid-catalyzed particle-phase reactions of organic carbonyls lead to multifold increases in secondary organic aerosol (SOA) mass and acid-catalyzed reactions between alcohols and aldehydes in the condensed phase lead to the formation of hemiacetals and acetals, also enhancing secondary organic aerosol growth. The kinetics and mechanism of the heterogeneous chemistry of carbonyls and alcohols with sulfuric acid, however, remain largely uncertain. In this talk, we present measurements of heterogeneous uptake of several carbonyls and alcohols on liquid H2SO4 in a wide range of acid concentrations and temperatures. The results indicate that uptake of larger carbonyls is explained by aldol condensation. For small dicarbonyls, heterogeneous reactions are shown to decrease with acidity and involve negligible formation of sulfate esters. Hydration and polymerization likely explain the measured uptake of such small dicarbonyls on H2SO4 and the measurements do not support an acid- catalyzed uptake. Atmospheric implications from our findings will be discussed.

  11. [pi] Backbonding in Carbonyl Complexes and Carbon-Oxygen Stretching Frequencies: A Molecular Modeling Exercise

    ERIC Educational Resources Information Center

    Montgomery, Craig D.

    2007-01-01

    An exercise is described that has illustrated the effect of various factors on [pi] backbonding to carbonyl ligands, where the students can view the molecular orbitals corresponding to the M-CO [pi] interaction as well as the competing interaction between the metal and co-ligands. The visual and hands-on nature of the modeling exercise has helped…

  12. Analysis of selected carbonyl oxidation products in wine by liquid chromatography with diode array detection.

    PubMed

    Elias, Ryan J; Laurie, V Felipe; Ebeler, Susan E; Wong, Jon W; Waterhouse, Andrew L

    2008-09-19

    A high performance liquid chromatography (HPLC) method for the detection and quantitation of acetaldehyde, glyceraldehyde, pyruvic acid, 2-ketoglutaric acid, and formaldehyde in wine, based on the formation of the 2,4-dinitrophenylhydrazones, is presented. These carbonyl compounds often result from the chemical oxidation of major wine components, and are known to affect flavor and color stability. Their analysis in wine is complicated due to their instability and their tendency to react reversibly with bisulfite to form alpha-hydroxysulfonates. Published methods that break down the sulfonates for the quantitation of total carbonyls in wine involve alkaline hydrolysis of sulfite-bound carbonyls, but we show, for the first time, that this alkaline treatment step significantly increases the concentration of carbonyls during analysis. A solution based on oxygen exclusion is described. The technique offers good specificity, reproducibility (%RSD 0.45-10.6), and limits of detection (1.29-7.53microgL(-1)). The method was successfully used to monitor concentration changes of these compounds in both white and red wines. PMID:18761127

  13. Identification of Protein Carbonyls in serum of the fetal and neonatal pig.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidation of serum proteins leads to non-reversible carbonyl formation which alters their function and has long been associated with stress-related disease processes. The primary objective of this study was to identify oxidized serum protein biomarkers of metabolic stress in baby pigs. Protein carb...

  14. A structural role for arginine in proteins: multiple hydrogen bonds to backbone carbonyl oxygens.

    PubMed

    Borders, C L; Broadwater, J A; Bekeny, P A; Salmon, J E; Lee, A S; Eldridge, A M; Pett, V B

    1994-04-01

    We propose that arginine side chains often play a previously unappreciated general structural role in the maintenance of tertiary structure in proteins, wherein the positively charged guanidinium group forms multiple hydrogen bonds to backbone carbonyl oxygens. Using as a criterion for a "structural" arginine one that forms 4 or more hydrogen bonds to 3 or more backbone carbonyl oxygens, we have used molecular graphics to locate arginines of interest in 4 proteins: Arg 180 in Thermus thermophilus manganese superoxide dismutase, Arg 254 in human carbonic anhydrase II, Arg 31 in Streptomyces rubiginosus xylose isomerase, and Arg 313 in Rhodospirillum rubrum ribulose-1,5-bisphosphate carboxylase/oxygenase. Arg 180 helps to mold the active site channel of superoxide dismutase, whereas in each of the other enzymes the structural arginine is buried in the "mantle" (i.e., inside, but near the surface) of the protein interior well removed from the active site, where it makes 5 hydrogen bonds to 4 backbone carbonyl oxygens. Using a more relaxed criterion of 3 or more hydrogen bonds to 2 or more backbone carbonyl oxygens, arginines that play a potentially important structural role were found in yeast enolase, Bacillus stearothermophilus glyceraldehyde-3-phosphate dehydrogenase, bacteriophage T4 and human lysozymes, Enteromorpha prolifera plastocyanin, HIV-1 protease, Trypanosoma brucei brucei and yeast triosephosphate isomerases, and Escherichia coli trp aporepressor (but not trp repressor or the trp repressor/operator complex).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8003972

  15. NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH

    EPA Science Inventory

    An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

  16. NMR Studies of Structure-Reactivity Relationships in Carbonyl Reduction: A Collaborative Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Marincean, Simona; Smith, Sheila R.; Fritz, Michael; Lee, Byung Joo; Rizk, Zeinab

    2012-01-01

    An upper-division laboratory project has been developed as a collaborative investigation of a reaction routinely taught in organic chemistry courses: the reduction of carbonyl compounds by borohydride reagents. Determination of several trends regarding structure-activity relationship was possible because each student contributed his or her results…

  17. Low-temperature N-O bond cleavage of nitrogen monoxide in heterometallic carbonyl complexes. An experimental and theoretical study.

    PubMed

    García, M Esther; Melón, Sonia; Ruiz, Miguel A; López, Ramón; Sordo, Tomás; Marchiò, Luciano; Tiripicchio, Antonio

    2008-11-17

    The reaction of Na[RuCp(CO) 2] with [MnCp'(CO) 2(NO)]BF 4 gives the corresponding heterometallic derivative [MnRuCpCp'(mu-CO) 2(CO)(NO)] (Cp = eta (5)-C 5H 5; Cp' = eta (5)-C 5H 4Me). In contrast, the group 6 metal carbonyl anions [MCp(CO) 2L] (-) (M = Mo, W; L = CO, P(OMe) 3, PPh 3) react with the Mn and Re complexes [M'Cp'(CO) 2(NO)]BF 4 to give the heterometallic derivatives [MM'CpCp'(mu-N)(CO) 3L] having a nitride ligand linearly bridging the metal centers (W-N = 1.81(3) A, N-Re = 1.97(3) A, W-N-Re = 179(1) (o), in [WReCpCp'(mu-N)(CO) 3{P(OMe) 3}]). Density-functional theory calculations on the reactions of [WCp(CO) 3] (-) and [RuCp(CO) 2] (-) with [MnCp(CO) 2(NO)] (+) revealed a comparable qualitative behavior. Thus, two similar and thermodynamically allowed reaction pathways were found in each case, one implying the displacement of CO from the cation and formation of a metal-metal bond, the other implying the cleavage of the N-O bond of the nitrosyl ligand and release of a carbonyl from the anion as CO 2. The second pathway is more exoergonic and is initiated through an orbitally controlled attack of the anion on the N atom of the NO ligand in the cation. In contrast, the first pathway is initiated through a charge-controlled attack of the anion to the C atom of a CO ligand in the cation. The CO 2-elimination pathway requires at the intermediate stages a close approach of the NO and CO ligands, which is more difficult for the Ru compound because of its lower coordination number (compared to W). This effect, when combined with a stronger stabilization of the initial intermediate in the Ru reaction, makes the CO 2-elimination pathway slower in that case. PMID:18928276

  18. Oxi-DIGE: A novel proteomic approach for detecting and quantifying carbonylated proteins.

    PubMed

    Baraibar, Martin; Ladouce, Romain; Friguet, Bertrand

    2014-10-01

    Proteins are involved in key cellular functions and our health and wellness depends on their quality. Accumulation of oxidatively damaged proteins is a hallmark of deleterious processes such increased oxidative stress, chronic inflammation, ageing and age-related diseases. Thus, quantifying and identifying oxidized proteins is a biomarker of choice for monitoring biological ageing and/or the efficiency of anti-oxidant, ant-inflammatory and anti-ageing therapies. However, the absence of reliable tools for analyses has inhibited its establishment as the gold standard for measuring the efficacy of anti-ageing and age related diseases interventions. Herein, we present a novel proteomics technology, named Oxi-DIGE?, which provides a significant improvement in terms of specificity, reproducibility and statistical support for proteomic analysis of carbonylated proteins. In Oxi-DIGE, protein carbonyls are labelled with fluorescent hydrazide probes that bind specifically to carbonyl groups in proteins. Experimental groups (e.g. control and experimental samples) are labelled with different flurophore-binded hydrazides that fluoresce light at different wavelengths, producing different colour fluorescence. Thus samples from different experimental groups are co-resolved on a single 2D gel. Increased accuracy is provided due to: (i) reduced false positives by using an exogenous synthetic fluorescent tag; (ii) multiplexing, that is the possibility to run multiple samples on the same gel, (iii) the use of an internal standard on each gel which eliminates inter-gel variations and provides an increased statistical confidence. In addition, the resolution of the carbonyl groups is improved, forming distinct spots that can be identified by mass spectrometry. ?Patent Application (M. Baraibar, R. Ladouce., B. Friguet, A method for detecting and/or quantifying carbonylated proteins (WO/2012/175519) filed by UPMC and referring to the technology described in this abstract. PMID:26461312

  19. Effects of garage employment and tobacco smoking on breathing-zone concentrations of carbonyl compounds.

    PubMed

    Zhang, Lin; Chung, Fung-Lung; Boccia, Laura; Colosimo, Steven; Liu, Weili; Zhang, Junfeng

    2003-01-01

    Exposure to carbonyl compounds may cause adverse health effects. The present study examined whether working in a garage and smoking can significantly affect personal "daily" exposure to a number of important carbonyl compounds. The study was carried out on 37 subjects including 22 garage workers (9 smokers and 13 nonsmokers) and 15 nongarage workers or so-called controls (4 smokers and 11 nonsmokers). Daily exposure was estimated using 48-hour integrated measurement of breathing-zone concentrations. The measurement involved the use of a passive carbonyl sampler and high performance liquid chromatography/fluorescence analysis technique. Each subject was measured for up to three measurement sessions. A wide range of breathing-zone concentrations (unit: microgram per cubic meter) was observed for each of the following carbonyls: formaldehyde (14.1-80.1); acetaldehyde (8.41-80.3); acetone (0.65-1096); acrolein (<0.14-3.71); propionaldehyde (1.08-14.6); crotonaldehyde (<0.13-2.80); benzaldehyde (1.79-9.91); and hexaldehyde (0.122-22.4). Statistical significance of smoking effects and working in a garage effects were assessed using SAS mixed models. The results show that the garage workers had significantly higher levels of formaldehyde and acetaldehyde than the controls, and that the smokers had significantly higher levels of acetaldehyde, propionaldehyde, and hexaldehyde, than the nonsmokers (P<.10). Garage employment and smoking appeared to increase breathing-zone concentrations of crotonaldehyde. In general, within-subject variations were smaller than between-subject variations on 48-hour averaged breathing-zone concentrations of carbonyl compounds. PMID:12809545

  20. Evaluation of hazardous airborne carbonyls on a university campus in southern China.

    PubMed

    Ho, Steven Sai Hang; Ip, Ho Sai Simon; Ho, Kin Fai; Ng, Louisa Pan Ting; Dai, W T; Cao, Junji; Chan, Chi Sing; Ho, Legolas Baggio

    2014-08-01

    A comprehensive assessment of indoor carbonyl compounds for the academic staff workers, and students was conducted on a university campus in Xiamen, China. A total of 15 representative environment categories, including 12 indoor workplaces and three residential units, were selected. The potential indoor pollution sources were identified based on the variability in the molar compositions and correlation analyses for the target carbonyls. Furnishing materials, cooking emissions, and electronic equipment, such as photocopiers, can generate various carbonyls in the workplace. Comparison studies were conducted in the clerical offices, demonstrating that off-gases from wooden furniture and lacquer coatings, environmental tobacco smoke (ETS), and the use of cleaning reagents elevated the indoor carbonyl levels. The measured concentrations of formaldehyde and acetaldehyde in most locations surpassed the exposure limit levels. The lifetime cancer hazard risk (R) associated with formaldehyde was above the concern risk level (1 x 10(-6)) in all of the workplaces. The results indicate that formaldehyde exposure is a valid occupational health and safety concern. Wooden furniture and refurbishing materials can pose serious health threats to occupants. The information in this study could act as a basis for future indoor air quality monitoring in Mainland China. Implications: A university campus represents a microscale city environment consisting of all the working, living, and commercial needs of staff and students. The scope of this investigation covers 21 hazardous carbonyl species based on samples collected from 15 categories of workplaces and residential building in a university campus in southern China. Findings of the study provide a comprehensive assessment of indoor air quality with regards to workers' health and safety. No similar study has been carried out in China. PMID:25185393

  1. Soil emission and uptake of carbonyl sulfide at a temperate mountain grassland

    NASA Astrophysics Data System (ADS)

    Kitz, Florian; Hammerle, Albin; Laterza, Tamara; Spielmann, Felix M.; Wohlfahrt, Georg

    2016-04-01

    Flux partitioning, i.e. inferring gross primary productivity (GPP) and ecosystem respiration from the measured net ecosystem carbon dioxide (CO2) exchange, is one uncertainty in modelling the carbon cycle and in times where robust models are needed to assess future global changes a persistent problem. A promising new approach is to derive GPP by measuring carbonyl sulfide (COS), the most abundant sulfur-containing trace gas in the atmosphere, with a mean concentration of about 500 pptv in the troposphere. This is possible because COS and CO2 enter the leaf via a similar pathway and are processed by the same enzyme (carbonic anhydrase). A prerequisite to use COS as a proxy for canopy photosynthesis is a robust estimation of COS sources and sinks in an ecosystem. Past studies described soils either as a sink or source, depending on properties like soil temperature and soil water content. The main aim of this study was to quantify the soil COS exchange and its drivers of a temperate mountain grassland in order to aid the use of COS as tracer for canopy CO2 and water vapor exchange. We conducted a field campaign with a Quantum cascade laser at a temperate mountain grassland to estimate the soil COS fluxes under ambient conditions and while simulating a drought. We used self-built fused silica (i.e. light-transparent) soil chambers to avoid COS emissions from built-in materials and to assess the impact of radiation. Vegetation was removed within the chambers, therefor more radiation reached the soil surface compared to natural conditions. This might be the reason for highly positive fluxes during daytime more similar to agricultural study sites. To further investigate this large soil COS source we conducted within canopy concentration measurements near the soil surface and still recorded fluxes confirming the soil as a COS source during daytime. Results from the drought experiment suggested a strong impact of incoming radiation on soil COS fluxes followed by soil

  2. Morally relevant potential.

    PubMed

    Hershenov, David B; Hershenov, Rose J

    2015-03-01

    Fetuses and infants are said to warrant protecting because of their potential. But valuing potential supposedly leads to absurdities like protecting cells that could be technologically altered to develop into persons. This can be avoided by recognising that morally relevant potential is determined by what is presently healthy development (proper functioning) for an organism. The only interests of mindless organisms are in the flourishing that necessarily depends upon their healthy functioning. They can be harmed when those interests are frustrated. We criticise McMahan for claiming that harm is instead a function of the degree of psychological ties to the future. PMID:24570396

  3. Identification, quantification, and functional aspects of skeletal muscle protein-carbonylation in vivo during acute oxidative stress.

    PubMed

    Fedorova, Maria; Kuleva, Nadezhda; Hoffmann, Ralf

    2010-05-01

    Reactive oxidative species (ROS) play important roles in cellular signaling but can also modify and often functionally inactivate other biomolecules. Thus, cells have developed effective enzymatic and nonenzymatic strategies to scavenge ROS. However, under oxidative stress, ROS production is able to overwhelm the scavenging systems, increasing the levels of functionally impaired proteins. A major class of irreversible oxidative modifications is carbonylation, which refers to reactive carbonyl-groups. In this investigation, we have studied the production and clearance rates for skeletal muscle proteins in a rat model of acute oxidative stress over a time period of 24 h using a gel-based proteomics approach. Optimized ELISA and Western blots with 10-fold improved sensitivities showed that the carbonylation level was stable at 4 nmol per mg protein 3 h following ROS induction. The carbonylation level then increased 3-fold over 6 h and then remained stable. In total, the oxidative stress changed the steady state levels of 20 proteins and resulted in the carbonylation of 38 skeletal muscle proteins. Carbonylation of these proteins followed diverse kinetics with some proteins being highly carbonylated very quickly, whereas others peaked in the 9 h sample or continued to increase up to 24 h after oxidative stress was induced. PMID:20377239

  4. Effect of olive mill wastewater phenol compounds on reactive carbonyl species and Maillard reaction end-products in ultrahigh-temperature-treated milk.

    PubMed

    Troise, Antonio Dario; Fiore, Alberto; Colantuono, Antonio; Kokkinidou, Smaro; Peterson, Devin G; Fogliano, Vincenzo

    2014-10-15

    Thermal processing and Maillard reaction (MR) affect the nutritional and sensorial qualities of milk. In this paper an olive mill wastewater phenolic powder (OMW) was tested as a functional ingredient for inhibiting MR development in ultrahigh-temperature (UHT)-treated milk. OMW was added to milk at 0.1 and 0.05% w/v before UHT treatment, and the concentration of MR products was monitored to verify the effect of OMW phenols in controlling the MR. Results revealed that OMW is able to trap the reactive carbonyl species such as hydroxycarbonyls and dicarbonyls, which in turn led to the increase of Maillard-derived off-flavor development. The effect of OMW on the formation of Amadori products and N-ε-(carboxymethyl)-lysine (CML) showed that oxidative cleavage, C2-C6 cyclization, and the consequent reactive carbonyl species formation were also inhibited by OMW. Data indicated that OMW is a functional ingredient able to control the MR and to improve the nutritional and sensorial attributes of milk. PMID:25280240

  5. Aryl formate as bifunctional reagent: applications in palladium-catalyzed carbonylative coupling reactions using in situ generated CO.

    PubMed

    Li, Haoquan; Neumann, Helfried; Beller, Matthias; Wu, Xiao-Feng

    2014-03-17

    After decades of development, carbonylation reactions have become one of the most powerful tools in modern organic synthesis. However, the requirement of CO gas limits the applications of such reactions. Reported herein is a versatile and practical protocol for carbonylative reactions which rely on the cooperation of phenyl formate and nonaflate, and the generation of CO in situ. This protocol has a high functionalgroup tolerance and could be applied in carbonylations with C, N, and, O nucleophiles. The corresponding amides, alkynones, furanones, and aryl benzoates were synthesized in good yields. PMID:24677435

  6. Effect of methanol-containing additive on the emission of carbonyl compounds from a heavy-duty diesel engine.

    PubMed

    Chao, H R; Lin, T C; Chao, M R; Chang, F H; Huang, C I; Chen, C B

    2000-03-13

    This study was aimed at determining the effect of methanol-containing additive (MCA) on the emission of carbonyl compounds (CBCs) generated from the diesel engine. For this experiment, a heavy-duty diesel engine was connected with a full flow critical flow ventri (CFV) type dilution tunnel, a Schenck GS-350 DC dynamometer, and a DC-IV control system in series. The operating conditions of the heavy-duty diesel engine for both cold-start and hot-start Transient Cycle tests and for both low-load and high-load steady-state tests were ascertained. The exhaust of CBCs collected from a 2,4-dinitrophenylhydrazine (2,4-DNPH)-coated cartridge were first converted to corresponding hydrazone derivatives, which were then solvent-eluted and analyzed by a High Performance Liquid Chromatograph (HPLC) with an ultraviolet-visible (UV) detector. When either 10% or 15% MCA was used, the emission factors of the CBCs acrolein and isovaleraldehyde increased by at least 91%. Accordingly, future studies must be done to cut down the emission of CBCs when MCA and methanol alternative fuels are used. PMID:10686377

  7. Iridium-catalyzed anti-diastereo- and enantioselective carbonyl (trimethylsilyl)allylation from the alcohol or aldehyde oxidation level.

    PubMed

    Han, Soo Bong; Gao, Xin; Krische, Michael J

    2010-07-01

    Using the ortho-cyclometalated pi-allyl iridium precatalyst (R)-I derived from [Ir(cod)Cl](2), 4-cyano-3-nitrobenzoic acid, (R)-SEGPHOS, and allyl acetate, enantioselective transfer hydrogenation of alpha-(trimethylsilyl)allyl acetate in the presence of aldehydes 2a-i mediated by 2-propanol delivers products of (trimethylsilyl)allylation 4a-i in good isolated yields and with exceptional levels of anti-diastereoselectivity and enantioselectivity (90-99% ee). In the absence of 2-propanol, but under otherwise identical reaction conditions, carbonyl (trimethylsilyl)allylation is achieved directly from the alcohol oxidation level to furnish an equivalent set of adducts 4a-i with roughly equivalent isolated yields and stereoselectivities. To evaluate the synthetic utility of the reaction products 4a-i, adduct 4g was converted to the 1,4-ene-diol 5g via dioxirane-mediated oxidative desilylation with allylic transposition, the allylic alcohol 6g via protodesilylation with allylic transposition, and the gamma-lactam 7g via chlorosulfonyl isocyanate-mediated cycloaddition. PMID:20540509

  8. Carbonyl trapping and antiglycative activities of olive oil mill wastewater.

    PubMed

    Navarro, Marta; Fiore, Alberto; Fogliano, Vincenzo; Morales, Francisco J

    2015-02-01

    The use of natural compounds as antiglycative agents to reduce the load of advanced glycation end products from diet is very promising. Olive mill wastewater is a by-product of the olive oil extraction processes with a high content of hydroxytyrosol, hydroxytyrosol derivatives and molecules containing o-dihydroxyl functions such as verbascoside. Two powders were obtained after the ultrafiltration and nanofiltration of olive mill wastewater, and successive spray drying with maltodextrin and acacia fiber. The samples were characterized by phenolic composition and antioxidant capacity. Antiglycative capacity was evaluated by in vitro BSA-glucose and BSA-methylglyoxal assays, formation of Amadori products and direct trapping of reactive dicarbonyls (methylglyoxal and glyoxal). Both ultrafiltered and nanofiltered olive mill wastewater powders had an activity comparable to quercetin and hydroxytyrosol against the inhibition of protein glycation (IC50 = 0.3 mg mL(-1)). The antiglycative activity of the powder was further investigated after separation by reverse phase solid extraction. Fractions extracted with the methanol content higher than 40% and rich in hydroxytyrosol and verbascoside exerted the highest reactivity against dicarbonyls. Data confirmed that the direct trapping of dicarbonyl compounds is the main route explaining the antiglycative action rather than of the already known antioxidant capacity. Results support further investigations to evaluate the technological feasibility to use olive mill wastewater powders as antiglycative ingredients in foods or in pharmacological preparations in future. PMID:25519075

  9. Polysulfides protect SH-SY5Y cells from methylglyoxal-induced toxicity by suppressing protein carbonylation: A possible physiological scavenger for carbonyl stress in the brain.

    PubMed

    Koike, Shin; Kayama, Tasuku; Yamamoto, Shigeyoshi; Komine, Daisuke; Tanaka, Ryo; Nishimoto, Shoichi; Suzuki, Toshihiro; Kishida, Atsushi; Ogasawara, Yuki

    2016-07-01

    The formation of advanced glycation end products (AGEs) is associated with various neurological disorders, such as Alzheimer's disease, Parkinson's disease and schizophrenia. Methylglyoxal (MG), a highly reactive dicarbonyl compound, is known to be a major precursor for AGEs in modified proteins. Thus, a scavenger of MG might provide beneficial effects by suppressing the accumulation of AGEs and the occurrence of diseases induced by carbonyl stress. Meanwhile, polysulfides, one of the typical bound sulfur species, are oxidized forms of hydrogen sulfide (H2S) and may play a variety of roles in the brain. Herein, we assessed the scavenging ability of polysulfides against neuronal carbonyl stress induced by MG. First, we showed that polysulfides could protect differentiated (df)-SH-SY5Y cells from MG-induced cytotoxicity. When cells were pretreated with polysulfides, MG-induced cytotoxicity was attenuated with a rapid decrease in intracellular MG levels. Moreover, we found that polysulfides significantly suppressed the formation of MG-modified proteins in df-SH-SY5Y cells. Although polysulfide treatment increased endogenous GSH levels in the neuronal cells, its effects on MG-induced cytotoxicity were not affected by GSH concentration. Our results demonstrated that polysulfides had the direct potentials to protect neuronal cells against MG separate to the enzymatic detoxification system that required GSH. PMID:27163164

  10. Effect of side-chain carbonyl groups on the interface of vinyl polymers with water.

    PubMed

    Oda, Yukari; Horinouchi, Ayanobu; Kawaguchi, Daisuke; Matsuno, Hisao; Kanaoka, Shokyoku; Aoshima, Sadahito; Tanaka, Keiji

    2014-02-11

    The nature of the polymer-water interface in the poly(methyl 2-propenyl ether) (PMPE)-water model system is investigated by sum-frequency generation spectroscopy, which at the moment gives the best depth resolution among available techniques. PMPE, synthesized via living cationic polymerization, is structurally similar to poly(methyl methacrylate) (PMMA) except for lacking a carbonyl group. We here probe the polymer local conformation as well as the aggregation states of water at the interface. Comparing the results of our measurements to the PMMA-water system, the effect of a carbonyl group on the water structure at the interface is discussed. This knowledge should be crucial to the design and construction of highly functionalized polymer interfaces for bioapplications. PMID:24467626

  11. Proton-Coupled Electron Transfer in the Reduction of Carbonyls by Samarium Diiodide-Water Complexes.

    PubMed

    Chciuk, Tesia V; Anderson, William R; Flowers, Robert A

    2016-07-20

    Reduction of carbonyls by SmI2 is significantly impacted by the presence of water, but the fundamental step(s) of initial transfer of a formal hydrogen atom from the SmI2-water reagent system to produce an intermediate radical is not fully understood. In this work, we provide evidence consistent with the reduction of carbonyls by SmI2-water proceeding through proton-coupled electron transfer (PCET). Combined rate and computational studies show that a model aldehyde and ketone are likely reduced through an asynchronous PCET, whereas reduction of a representative lactone occurs through a concerted PCET. In the latter case, concerted PCET is likely a consequence of significantly endergonic initial electron transfer. PMID:27367158

  12. Polar [3 + 2] cycloaddition of ketones with electrophilically activated carbonyl ylides. Synthesis of spirocyclic dioxolane indolinones.

    PubMed

    Bentabed-Ababsa, Ghenia; Derdour, Aicha; Roisnel, Thierry; Sáez, Jose A; Domingo, Luis R; Mongin, Florence

    2008-09-01

    The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and ketones (ethyl pyruvate, ethyl phenylglyoxylate, isatin, N-methylisatin and 5-chloroisatin) to give substituted dioxolanes and spirocyclic dioxolane indolinones was investigated. The effect of microwave irradiation on the outcome of the reaction was studied. The thermal reaction between 2,2-dicyano-3-phenyloxirane and N-methylisatin was theoretically studied using DFT methods. This reaction is a domino process that comprises two steps. The first is the thermal ring opening of the epoxide to yield a carbonyl ylide intermediate, whereas the second step is a polar [3 + 2] cycloaddition to yield the final spiro cycloadducts. The cycloaddition presents a low stereoselectivity and a large regio- and chemoselectivity. Analysis of the electrophilicity values and the Fukui functions of the reagents involved in the cycloaddition step allowed the chemical outcome to be explained. PMID:18698474

  13. Hydrogen sulfide selectivity with carbonyl sulfide removal to less than PPM levels

    SciTech Connect

    Bacon, T.R.; Pearce, R.L.; Foster, W.R. Jr.

    1986-01-01

    Changes in market conditions and plant operating economics require examination of traditional processes and operating practices in gas treating applications for upgrading to more stringent standards of efficiency in order to remain competitive while returning a satisfactory operating profit margin to the company. Anticipated reduction in solvent usage, improvements in Claus sulfur recovery unit performance and lower energy costs induced Ashland's Catlettsburg refinery to convert its entire sulfur removal system from monoethanolamine to methyldiethanolamine. One of the seven product streams being treated required extremely low carbonyl sulfide specifications. When the initial converted operations evidenced a need to improve the carbonyl sulfide removal, GAS/SPEC Tech Service produced an innovative solution which allowed for efficient operation which still achieved these objectives.

  14. Chemoselective reduction of the carbonyl functionality through hydrosilylation: integrating click catalysis with hydrosilylation in one pot.

    PubMed

    Roy, Sudipta Raha; Sau, Samaresh Chandra; Mandal, Swadhin K

    2014-10-01

    Herein we report the chemoselective reduction of the carbonyl functionality via hydrosilylation using a copper(I) catalyst bearing the abnormal N-heterocyclic carbene 1 with low (0.25 mol %) catalyst loading at ambient temperature in excellent yield within a very short reaction time. The hydrosilylation reaction of α,β-unsaturated carbonyl compounds takes place selectively toward 1,2-addition (C═O) to yield the corresponding allyl alcohols in good yields. Moreover, when two reducible functional groups such as imine and ketone groups are present in the same molecule, this catalyst selectively reduces the ketone functionality. Further, 1 was used in a consecutive fashion by combining the Huisgen cycloaddition and hydrosilylation reactions in one pot, yielding a range of functionalized triazole substituted alcohols in excellent yields. PMID:25188382

  15. Molecular Active Sites in Heterogeneous Ir-La/C-Catalyzed Carbonylation of Methanol to Acetates.

    PubMed

    Kwak, Ja Hun; Dagle, Robert; Tustin, Gerald C; Zoeller, Joseph R; Allard, Lawrence F; Wang, Yong

    2014-02-01

    We report that when Ir and La halides are deposited on carbon, exposure to CO spontaneously generates a discrete molecular heterobimetallic structure, containing an Ir-La covalent bond that acts as a highly active, selective, and stable heterogeneous catalyst for the carbonylation of methanol to produce acetic acid. This catalyst exhibits a very high productivity of ∼1.5 mol acetyl/mol Ir·s with >99% selectivity to acetyl (acetic acid and methyl acetate) without detectable loss in activity or selectivity for more than 1 month of continuous operation. The enhanced activity can be mechanistically rationalized by the presence of La within the ligand sphere of the discrete molecular Ir-La heterobimetallic structure, which acts as a Lewis acid to accelerate the normally rate-limiting CO insertion in Ir-catalyzed carbonylation. Similar approaches may provide opportunities for attaining molecular (single site) behavior similar to homogeneous catalysis on heterogeneous surfaces for other industrial applications. PMID:26276610

  16. Polyimides with carbonyl and ether connecting groups between the aromatic rings

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M. (Inventor); Havens, Stephen J. (Inventor)

    1992-01-01

    New polyimides have been prepared from the reaction of aromatic dianhydrides with novel aromatic diamines containing carbonyl and ether connecting groups between the aromatic rings. Several of these polyimides are shown to be semi-crystalline as evidenced by wide angle x ray diffraction and differential scanning calorimetry. Most of the polyimides form tough solvent resistant films with high tensile properties. Several of these materials can be thermally processed to form solvent and base resistant moldings.

  17. Density functional theory study of electroreductive hydrocoupling of alpha,beta-unsaturated carbonyl compounds.

    PubMed

    Kise, Naoki

    2006-11-24

    [reaction: see text] The electroreductive hydrocoupling of methyl cinnamate, methyl crotonate, cumarin, and benzalacetone was studied by DFT (B3LYP/6-311++ G**) calculations. The computational outcomes for the transition states in the hydrocoupling of anion radicals generated by a one-electron transfer to the alpha,beta-unsaturated carbonyl compounds well agree with the diastereoselectivities in the experimental results previously reported. PMID:17109548

  18. Identification of the reactive cysteine residue (Cys227) in human carbonyl reductase.

    PubMed

    Tinguely, J N; Wermuth, B

    1999-02-01

    Carbonyl reductase is highly susceptible to inactivation by organomercurials suggesting the presence of a reactive cysteine residue in, or close to, the active site. This residue is also close to a site which binds glutathione. Structurally, carbonyl reductase belongs to the short-chain dehydrogenase/reductase family and contains five cysteine residues, none of which is conserved within the family. In order to identify the reactive residue and investigate its possible role in glutathione binding, alanine was substituted for each cysteine residue of human carbonyl reductase by site-directed mutagenesis. The mutant enzymes were expressed in Escherichia coli and purified to homogeneity. Four of the five mutants (C26A, C122A C150A and C226A) exhibited wild-type-like enzyme activity, although K(m) values of C226A for three structurally different substrates were increased threefold to 10-fold. The fifth mutant, C227A, showed a 10-15-fold decrease in kcat and a threefold to 40-fold increase in K(m), resulting in a 30-500-fold drop in kcat/K(m). NaCl (300 mM) increased the activity of C227A 16-fold, whereas the activity of the wild-type enzyme was only doubled. Substitution of serine rather than alanine for Cys227 similarly affected the kinetic constants with the exception that NaCl did not activate the enzyme. Both C227A and C227S mutants were insensitive to inactivation by 4-hydroxymercuribenzoate. Unlike the parent carbonyl compounds, the glutathione adducts of menadione and prostaglandin A1 were better substrates for the C227A and C227S mutants than the wild-type enzyme. Conversely, the binding of free glutathione to both mutants was reduced. Our findings indicate that Cys227 is the reactive residue and suggest that it is involved in the binding of both substrate and glutathione. PMID:10091578

  19. Interdisciplinary neurotoxicity inhalation studies: Carbon disulfide and carbonyl sulfide research in F344 rats

    SciTech Connect

    Sills, Robert C. . E-mail: sills@niehs.nih.gov; Harry, G. Jean; Valentine, William M.; Morgan, Daniel L.

    2005-09-01

    Inhalation studies were conducted on the hazardous air pollutants, carbon disulfide, which targets the central nervous system (spinal cord) and peripheral nervous system (distal portions of long myelinated axons), and carbonyl sulfide, which targets the central nervous system (brain). The objectives were to investigate the neurotoxicity of these compounds by a comprehensive evaluation of function, structure, and mechanisms of disease. Through interdisciplinary research, the major finding in the carbon disulfide inhalation studies was that carbon disulfide produced intra- and intermolecular protein cross-linking in vivo. The observation of dose-dependent covalent cross-linking in neurofilament proteins prior to the onset of lesions is consistent with this process contributing to the development of the neurofilamentous axonal swellings characteristic of carbon disulfide neurotoxicity. Of significance is that valine-lysine thiourea cross-linking on rat globin and lysine-lysine thiourea cross-linking on erythrocyte spectrin reflect cross-linking events occurring within the axon and could potentially serve as biomarkers of carbon disulfide exposure and effect. In the carbonyl sulfide studies, using magnetic resonance microscopy (MRM), we determined that carbonyl sulfide targets the auditory pathway in the brain. MRM allowed the examination of 200 brain slices and made it possible to identify the most vulnerable sites of neurotoxicity, which would have been missed in our traditional neuropathology evaluations. Electrophysiological studies were focused on the auditory system and demonstrated decreases in auditory brain stem evoked responses. Similarly, mechanistic studies focused on evaluating cytochrome oxidase activity in the posterior colliculus and parietal cortex. A decrease in cytochrome oxidase activity was considered to be a contributing factor to the pathogenesis of carbonyl sulfide neurotoxicity.

  20. Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry.

    PubMed

    Muftakhov; Vasil'ev; Mazunov

    1999-06-01

    Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd. PMID:10407285

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

    PubMed

    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. PMID:25470461

  2. On the satisfaction of backbone-carbonyl lone pairs of electrons in protein structures.

    PubMed

    Bartlett, Gail J; Woolfson, Derek N

    2016-04-01

    Protein structures are stabilized by a variety of noncovalent interactions (NCIs), including the hydrophobic effect, hydrogen bonds, electrostatic forces and van der Waals' interactions. Our knowledge of the contributions of NCIs, and the interplay between them remains incomplete. This has implications for computational modeling of NCIs, and our ability to understand and predict protein structure, stability, and function. One consideration is the satisfaction of the full potential for NCIs made by backbone atoms. Most commonly, backbone-carbonyl oxygen atoms located within α-helices and β-sheets are depicted as making a single hydrogen bond. However, there are two lone pairs of electrons to be satisfied for each of these atoms. To explore this, we used operational geometric definitions to generate an inventory of NCIs for backbone-carbonyl oxygen atoms from a set of high-resolution protein structures and associated molecular-dynamics simulations in water. We included more-recently appreciated, but weaker NCIs in our analysis, such as n→π* interactions, Cα-H bonds and methyl-H bonds. The data demonstrate balanced, dynamic systems for all proteins, with most backbone-carbonyl oxygen atoms being satisfied by two NCIs most of the time. Combinations of NCIs made may correlate with secondary structure type, though in subtly different ways from traditional models of α- and β-structure. In addition, we find examples of under- and over-satisfied carbonyl-oxygen atoms, and we identify both sequence-dependent and sequence-independent secondary-structural motifs in which these reside. Our analysis provides a more-detailed understanding of these contributors to protein structure and stability, which will be of use in protein modeling, engineering and design. PMID:26833776

  3. Catalytic Addition of Simple Alkenes to Carbonyl Compounds Using Group 10 Metals

    PubMed Central

    Schleicher, Kristin D.

    2011-01-01

    Recent advances using nickel complexes in the activation of unactivated monosubstituted olefins for catalytic intermolecular carbon–carbon bond-forming reactions with carbonyl compounds, such as simple aldehydes, isocyanates, and conjugated aldehydes and ketones, are discussed. In these reactions, the olefins function as vinyl- and allylmetal equivalents, providing a new strategy for organic synthesis. Current limitations and the outlook for this new strategy are also discussed. PMID:21904421

  4. Water gas shift reaction: homogeneous catalysis by ruthenium and other metal carbonyls

    SciTech Connect

    Ford, P.C.

    1981-02-01

    A number of chemical systems are active for homogeneous, solution phase catalysis of the water gas shift reaction (WGSR). Catalysis of the shift reaction appears to be a quite general property of carbonyl complexes in alkaline solutions. The key mechanistic steps for which some kinetics information is available are the activation of coordinated CO by reaction with hydroxide and the reductive elimination of dihydrogen from a resulting metal hydride. Which of these is rate limiting in a cycle is a function of the specific metal system and the specific reaction conditions. A basic solution is not a necessary condition for WGSR catalysis. Although WGSR catalysis is not as general a phenomenon in acidic media, several such systems have been characterized with activities which compare very favorably to those seen in basic solutions. While logical mechanisms have been proposed for several of the better characterized catalysts, it is clear that a more complete mechanistic understanding of the key steps in potential cycles is greatly needed. Recognition of such needs has led to fundamental studies into the acid/base natures of metal carbonyl hydride clusters, of CO activation on cluster and mononuclear metal carbonyls by bases, and of dihydrogen elimination from and declusterification and clusterification reactions of metal carbonyl hydrides. While none of these processes is in itself catalytic, the sum of several represents possible cycles. With regard to the future of homogeneous WGSR catalysts, it is obvious that under the conditions which these have been tested, the known systems are not commercially viable. Certainly, for a reaction such as the WGSR for which effective heterogeneous catalysts are known, it will take substantial advantages for a new system to be an attractive alternative to established technology.

  5. One-Pot Synthesis of β,β-Disubstituted α,β-Unsaturated Carbonyl Compounds.

    PubMed

    Sugiura, Masaharu; Ashikari, Yasuhiko; Nakajima, Makoto

    2015-09-01

    TiCl4-promoted aldol reaction of ketones as aldol acceptors followed by elimination of the titanoxy group from the Ti-aldolates affords β,β-disubstituted α,β-unsaturated carbonyl compounds in a one-pot procedure. The use of additives, such as DMF, N,N,N',N'-tetramethylethylenediamine, and pyridine, in the elimination step was found to be important. PMID:26284292

  6. Synthesis and absorbing mechanism of two-layer microwave absorbers containing polycrystalline iron fibers and carbonyl iron

    NASA Astrophysics Data System (ADS)

    Ding, Qingwei; Zhang, Mingang; Zhang, Cunrui; Qian, Tianwei

    2013-04-01

    Polycrystalline iron fibers were fabricated by α-FeOOH fiber precursors. Two-layer microwave absorber had been prepared by as-prepared polycrystalline iron fibers and carbonyl iron. The structure, morphology and properties of the composites were characterized with X-ray diffraction, scanning electron microscope and Network Analyzer. The complex permittivity and reflection loss (dB) of the composites were measured employing vector network analyzer model PNA 3629D vector in the frequency range between 30 and 6000 MHz. The thickness effect of the carbonyl iron layer on the microwave loss properties of the composites was investigated. A possible microwave-absorbing mechanism of polycrystalline iron fibers/carbonyl iron composite was proposed. The polycrystalline iron fibers/carbonyl iron composite can find applications in suppression of electromagnetic interference, and reduction of radar signature.

  7. Facile Access to Sterically Hindered Aryl Ketones via Carbonylative Cross-Coupling: Application to the Total Synthesis of Luteolin

    PubMed Central

    O’Keefe, B. Michael; Simmons, Nicholas

    2011-01-01

    A general and mild protocol for achieving the carbonylative cross-coupling of sterically-hindered, ortho-disubstituted aryl ketones is reported. The commercially available PEPPSI-IPr catalyst is shown to efficiently promote the carbonylative cross-coupling of hindered ortho-disubstituted aryl iodides to give diaryl ketones; traditional phosphine catalysts are less effective. Carbonylative Suzuki-Miyaura cross-couplings provide a diverse array of biaryl ketones in good to excellent yields. The same catalyst is also shown to catalyze a carbonylative Negishi cross-coupling reaction, utilizing a variety of alkynyl zinc reagents to give the corresponding alkynyl aryl ketones. Application of this new methodology to the synthesis of the natural product luteolin is reported. PMID:21712966

  8. Some features of the change in the carbonyl group content of coal in the process of metamorphism

    SciTech Connect

    Kucherenko, V.A.; Kuznetsova, L.V.; Sapunov, V.A.; Osipov, A.M.

    1983-01-01

    Different forms of carbonyl groups were studied in Donbass coals and it was shown that there is a relationship between the variation in quinoidal and ketonic oxygen and the degree of metamorphism. (17 refs.)

  9. Mitochondrial ascorbate-glutathione cycle and proteomic analysis of carbonylated proteins during tomato (Solanum lycopersicum) fruit ripening.

    PubMed

    López-Vidal, O; Camejo, D; Rivera-Cabrera, F; Konigsberg, M; Villa-Hernández, J M; Mendoza-Espinoza, J A; Pérez-Flores, L J; Sevilla, F; Jiménez, A; Díaz de León-Sánchez, F

    2016-03-01

    In non-photosynthetic tissues, mitochondria are the main source of energy and of reactive oxygen species. Accumulation of high levels of these species in the cell causes damage to macromolecules including several proteins and induces changes in different metabolic processes. Fruit ripening has been characterized as an oxidative phenomenon; therefore, control of reactive oxygen species levels by mitochondrial antioxidants plays a crucial role on this process. In this work, ascorbate-glutathione cycle components, hydrogen peroxide levels and the proteomic profile of carbonylated proteins were analyzed in mitochondria isolated from tomato (Solanum lycopersicum) fruit at two ripening stages. A significant increase on most ascorbate-glutathione cycle components and on carbonylated proteins was observed in mitochondria from breaker to light red stage. Enzymes and proteins involved in diverse cellular and mitochondrial metabolic pathways were identified among the carbonylated proteins. These results suggest that protein carbonylation is a post-translational modification involved in tomato fruit ripening regulation. PMID:26471654

  10. Consideration of reactivity to acute fish toxicity of α,β-unsaturated carbonyl ketones and aldehydes.

    PubMed

    Furuhama, A; Aoki, Y; Shiraishi, H

    2012-01-01

    To understand the key factor for fish toxicity of 11 α,β-unsaturated carbonyl aldehydes and ketones, we used quantum chemical calculations to investigate their Michael reactions with methanethiol or glutathione. We used two reaction schemes, with and without an explicit water molecule (Scheme-1wat and Scheme-0wat, respectively), to account for the effects of a catalytic water molecule on the reaction pathway. We determined the energies of the reactants, transition states (TS), and products, as well as the activation energies of the reactions. The acute fish toxicities of nine of the carbonyl compounds were evaluated to correlate with their hydrophobicities; no correlation was observed for acrolein and crotonaldehyde. The most toxic compound, acrolein, had the lowest activation energy. The activation energy of the reaction could be estimated with Scheme-1wat but not with Scheme-0wat. The complexity of the reaction pathways of the compounds was reflected in the difficulty of the TS structure searches when Scheme-1wat was used with the polarizable continuum model. The theoretical estimations of activation energies of α,β-unsaturated carbonyl compounds with catalytic molecules or groups including hydrogen-bond networks may complement traditional tools for predicting the acute aquatic toxicities of compounds that cannot be easily obtained experimentally. PMID:22150015

  11. Uncertainties of polynuclear aromatic hydrocarbon and carbonyl measurements in heavy-duty diesel emission.

    PubMed

    Mabilia, Rosanna; Cecinato, Angelo; Guerriero, Ettore; Possanzini, Massimiliano

    2006-02-01

    In this note we describe the speciated particle-phase PM2.5 polynuclear aromatic hydrocarbon (PAH) and gas-phase carbonyl emissions as collected from a heavy-duty diesel bus outfitted with an oxidation catalyst for exhaust after-treatment. The vehicle was run on a chassis dynamometer during a transient cycle test reproducing a typical city bus route (Azienda Tramviaria Municipalizzata cycle). The diluted tailpipe emissions were sampled for PAH using a 2.5 microm cut size cyclone glass fiber filter assembly, while carbonyls were absorbed onto dinitrophenyl hydrazine-coated silica cartridges. The former compounds were analysed by CGC-MS, the latter by HPLC-UV. Combining the two sets of speciation data resulting from 15 identical dynamometer tests provided a profile of both unregulated organic emissions. PAH emission rates decreased with the number of benzene fused rings. Fluoranthene and pyrene amounted to 90% of total PAHs quantified; six-ring PAHs accounted only for 0.5%. Similarly, formaldehyde and acetaldehyde accounted for approximately 80% of the total carbonyl emissions. Uncertainties of the method in the determination of individual emission factors were calculated. Statistical data processing revealed that all the measurements were quite unaffected by systematic errors and repeatability percentages did not exceed 50% for the majority of components of both groups. PMID:16524107

  12. Synthesis, structural and vibrational properties of 1-(adamantane-1-carbonyl)-3-halophenyl thioureas

    NASA Astrophysics Data System (ADS)

    Saeed, Aamer; Erben, Mauricio F.; Bolte, Michael

    2013-02-01

    1-(Adamantane-1-carbonyl)-3-(2,4-dichlorophenyl)thiourea (1) and 1-(adamantane-1-carbonyl)-3-(2-bromo-4,6-difluorophenyl)thiourea (2) were synthesized by the reaction of adamantane-1-carbonyl chloride with ammonium thiocyanate to afford the adamantane-1-carbonylisothiocyanate in situ followed by treatment with suitable halogenated anilines. The structures of the products were established by elemental analyses, Fourier transform infrared spectroscopy (FTIR), 1H, 13C nuclear magnetic resonance (NMR), mass spectroscopy and single crystal X-ray diffraction study. Bond lengths and angles show the usual values. All of three condensed cyclohexane rings of the adamantane residues adopt the usual chair conformation. The molecular conformation of 1 and 2 is stabilized by an intramolecular (Nsbnd H⋯Odbnd C) hydrogen bond which forms a pseudo-six-membered ring. Structural features have been complemented with the joint analysis of the FTIR and FT-Raman spectra along with quantum chemical calculations at the B3LYP/6-311++G** level.

  13. Synthesis, structural and vibrational properties of 1-(adamantane-1-carbonyl)-3-halophenyl thioureas.

    PubMed

    Saeed, Aamer; Erben, Mauricio F; Bolte, Michael

    2013-02-01

    1-(Adamantane-1-carbonyl)-3-(2,4-dichlorophenyl)thiourea (1) and 1-(adamantane-1-carbonyl)-3-(2-bromo-4,6-difluorophenyl)thiourea (2) were synthesized by the reaction of adamantane-1-carbonyl chloride with ammonium thiocyanate to afford the adamantane-1-carbonylisothiocyanate in situ followed by treatment with suitable halogenated anilines. The structures of the products were established by elemental analyses, Fourier transform infrared spectroscopy (FTIR), (1)H, (13)C nuclear magnetic resonance (NMR), mass spectroscopy and single crystal X-ray diffraction study. Bond lengths and angles show the usual values. All of three condensed cyclohexane rings of the adamantane residues adopt the usual chair conformation. The molecular conformation of 1 and 2 is stabilized by an intramolecular (NH⋯OC) hydrogen bond which forms a pseudo-six-membered ring. Structural features have been complemented with the joint analysis of the FTIR and FT-Raman spectra along with quantum chemical calculations at the B3LYP/6-311++G level. PMID:23246730

  14. Theoretical investigation of N-nitrosodimethylamine formation from dimethylamine nitrosation catalyzed by carbonyl compounds.

    PubMed

    Lv, Chun-Lin; Liu, Yong Dong; Zhong, Ru-Gang

    2009-01-29

    The carbonyl-compound-catalyzed nitrosation of amines to form carcinogenic nitrosamines under nonacidic condition is different from the classic nitrosation via acidification of nitrite anion. The mechanistic pathways of N-nitrosodimethylamine (NDMA) formation by the reactions of dimethylamine (DMA) with the nitrite anion catalyzed by carbonyl compounds have been investigated using the DFT/B3LYP method at the 6-311+G(d,p) level. The computational results show that the energy barriers of the nucleophilic addition reaction, which were calculated as 27-40 kcal/mol, increase significantly with methylation but vary slightly with chloromethylation on the carbonyl group. Comparison of energy barriers of this nucleophilic addition reaction and the electrophilic substitution reaction indicates that the former is the rate-determining step, from which the order of the catalytic activity is obtained as formaldehyde > chloral > acetaldehyde > acetone. Furthermore, analysis of electronic and steric effects on catalytic activity reveals that electron-withdrawing substituents decrease the energy barrier but electron-donating substituents and steric hindrance will block this catalytic reaction. Based on this discovery, fluoral is proposed as a good catalyst for the nitrosation of DMA by nitrite anion, which has a calculated energy barrier of about 26 kcal/mol. The results obtained in this work will help elucidate the mechanisms of formation of nitrosamines. PMID:19119806

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Brown carbon formation by aqueous-phase carbonyl compound reactions with amines and ammonium sulfate.

    PubMed

    Powelson, Michelle H; Espelien, Brenna M; Hawkins, Lelia N; Galloway, Melissa M; De Haan, David O

    2014-01-21

    Reactions between small water-soluble carbonyl compounds, ammonium sulfate (AS), and/or amines were evaluated for their ability to form light-absorbing species in aqueous aerosol. Aerosol chemistry was simulated with bulk phase reactions at pH 4, 275 K, initial concentrations of 0.05 to 0.25 M, and UV-vis and fluorescence spectroscopy monitoring. Glycolaldehyde-glycine mixtures produced the most intense absorbance. In carbonyl compound reactions with AS, methylamine, or AS/glycine mixtures, product absorbance followed the order methylglyoxal > glyoxal > glycolaldehyde > hydroxyacetone. Absorbance extended into the visible, with a wavelength dependence fit by absorption Ångstrom coefficients (Å(abs)) of 2 to 11, overlapping the Å(abs) range of atmospheric, water-soluble brown carbon. Many reaction products absorbing between 300 and 400 nm were strongly fluorescent. On a per mole basis, amines are much more effective than AS at producing brown carbon. In addition, methylglyoxal and glyoxal produced more light-absorbing products in reactions with a 5:1 AS-glycine mixture than with AS or glycine alone, illustrating the importance of both organic and inorganic nitrogen in brown carbon formation. Through comparison to biomass burning aerosol, we place an upper limit on the contribution of these aqueous carbonyl-AS-amine reactions of ≤ 10% of global light absorption by brown carbon. PMID:24351110

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

    PubMed

    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

    2016-01-01

    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. PMID:27265207

  18. Effect of carbonyl inhibitors and their H₂O₂ detoxification on lactic acid fermentation.

    PubMed

    Li, Jing; Zhu, Caiqing; Tu, Maobing; Han, Pingping; Wu, Yonnie

    2015-04-01

    Biomass degradation compounds significantly inhibit biochemical conversion of biomass prehydrolysates to biofuels and chemicals, such as lactic acid. To characterize the structure-activity relationship of carbonyl inhibition on lactic acid fermentation, we examined effects of eight carbonyl compounds (furfural, 5-hydroxymethyl furfural, vanillin, syringaldehyde, 4-hydroxybenzaldehyde, phthalaldehyde, benzoic acid, and pyrogallol aldehyde) and creosol on lactic acid production by Lactobacillus delbrueckii. Pyrogallol aldehyde reduced the cell growth rate by 35 % at 1.0 mM and inhibited lactic acid production completely at 2.0 mM. By correlating the molecular descriptors to the inhibition constants in lactic acid fermentation, we found a good relationship between the hydrophobicity (Log P) of aldehydes and their inhibition constants in fermentation. The inhibitory effect of carbonyl inhibitors appeared to correlate with their thiol reactivity as well. In addition, we found that H2O2 detoxified pyrogallol aldehyde and phthalaldehyde inhibitory activity. H2O2 detoxification was applied to real biomass prehydrolysates in lactic acid fermentation. PMID:25666370

  19. Nitrite promotes protein carbonylation and Strecker aldehyde formation in experimental fermented sausages: are both events connected?

    PubMed

    Villaverde, A; Ventanas, J; Estévez, M

    2014-12-01

    The role played by curing agents (nitrite, ascorbate) on protein oxidation and Strecker aldehyde formation is studied. To fulfill this objective, increasing concentrations of nitrite (0, 75 and 150ppm) and ascorbate (0, 250 and 500ppm) were added to sausages subjected to a 54day drying process. The concurrence of intense proteolysis, protein carbonylation and formation of Strecker aldehydes during processing of sausages suggests that α-aminoadipic semialdehyde (AAS) and γ-glutamic semialdehyde (GGS) may be implicated in the formation of Strecker aldehydes. The fact that nitrite (150ppm, ingoing amount) significantly promoted the formation of protein carbonyls at early stages of processing and the subsequent formation of Strecker aldehydes provides strength to this hypothesis. Ascorbate (125 and 250ppm) controlled the overall extent of protein carbonylation in sausages without declining the formation of Strecker aldehydes. These results may contribute to understanding the chemistry fundamentals of the positive influence of nitrite on the flavor and overall acceptability of cured muscle foods. PMID:25089792

  20. Carbonyl Compounds in the Gas Phase of Cigarette Mainstream Smoke and Their Pharmacological Properties.

    PubMed

    Horinouchi, Takahiro; Higashi, Tsunehito; Mazaki, Yuichi; Miwa, Soichi

    2016-01-01

    Cigarette mainstream smoke is composed of gas and tar phases and contains >4000 chemical constituents, including nicotine and tar. The substances in the gas phase but not in the tar phase can pass through the airway epithelial barrier, enter the systemic circulation via the pulmonary circulation, and increase systemic oxidative damage, leading to the development of cigarette smoking-related diseases such as atherosclerosis. Recently, we identified some stable carbonyl compounds, including acrolein (ACR) and methyl vinyl ketone (MVK), as major cytotoxic factors in nicotine- and tar-free cigarette smoke extract (CSE) of the gas phase. CSE, ACR, and MVK induce protein kinase C (PKC)-dependent activation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and subsequent generation of reactive oxygen species (ROS) via NOX, causing plasma membrane damage and cell apoptosis. CSE, ACR, and MVK also trigger carbonylation of PKC, which is an irreversible oxidative modification. Cell damage and PKC carbonylation in response to treatment with CSE, ACR, or MVK are abolished by thiol-containing antioxidants such as N-acetyl-L-cysteine and reduced glutathione. Thus pharmacological modulation of PKC and NOX activities and the trapping of ROS are potential strategies for the prevention of diseases related to cigarette smoking. PMID:27251492

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27265207

  2. Synthesis of beta-lactones by the regioselective, cobalt and Lewis acid catalyzed carbonylation of simple and functionalized epoxides.

    PubMed

    Lee, J T; Thomas, P J; Alper, H

    2001-08-10

    The PPNCo(CO)(4) and BF(3) x Et(2)O catalyzed carbonylation of simple and functionalized epoxides in DME gives the corresponding beta-lactones regioselectively in good to high yields. The carbonylation occurred selectively at the unsubstituted C-O bond of the epoxide ring, and this reaction tolerates various functional groups such as alkenyl, halide, hydroxy, and alkyl ether. PMID:11485465

  3. Asymmetric Conjugate Alkynylation of Cyclic α,β-Unsaturated Carbonyl Compounds with a Chiral Diene Rhodium Catalyst.

    PubMed

    Dou, Xiaowei; Huang, Yinhua; Hayashi, Tamio

    2016-01-18

    Asymmetric conjugate alkynylation of cyclic α,β-unsaturated carbonyl compounds (ketones, esters, and amides) was realized by use of diphenyl[(triisopropylsilyl)ethynyl]methanol as an alkynylating reagent in the presence of a rhodium catalyst coordinated with a new chiral diene ligand (Fc-bod; bod=bicyclo[2.2.2]octa-2,5-diene, Fc=ferrocenyl) to give high yields of the corresponding β-alkynyl-substituted carbonyl compounds with 95-98% ee. PMID:26636764

  4. Spectroscopic Investigation of the Species Involved in the Rhodium-Catalyzed Oxidative Carbonylation of Toluene to Toluic Acid

    SciTech Connect

    Zakzeski, Joseph; Burton, Sarah D.; Behn, Andrew; Head-Gordon, Martin P.; Bell, Alexis T.

    2009-11-14

    A spectroscopic investigation of complexes used to catalyze the oxidative carbonylation of toluene to para-toluic acid was conducted. Rhodium complexes were analyzed by 103Rh and 13C NMR, UV-visible spectroscopy, and infrared spectroscopy. In the presence of vanadium and oxygen, the resting state of the Rh catalyst was found to exist as a Rh(III) complex with carbonyl and trifluoroacetate ligands, consistent with the structure Rh(CO)2(TFA)3. The complex exhibited a carbonyl peak with an unusual degree of shielding, which resulted in the appearance of the carbonyl peak at an unprecedented upfield position in the 13C NMR spectrum. This shielding was caused by interaction of the carbonyl group with the trifluoroacetate ligand. In the absence of oxygen, the Rh(III) complex reduced to Rh(I), and the reduced form exhibited properties resembling the catalyst precursor. Structures and spectroscopic properties calculated using Density Functional Theory were in good agreement with experimental results. The vanadium co-catalyst was similarly characterized by 51V NMR and UV-visible spectroscopy. The oxidized species corresponded to [(VO2)(TFA)]2, whereas the reduced species corresponded (VO)(TFA)2. The spectroscopic results obtained in this study confirm the identity of the species that have been proposed to be involved in the Rh-catalyzed oxidative carbonylation of toluene to toluic acid.

  5. Structure-toxicity relationships for the effects to Tetrahymena pyriformis of aliphatic, carbonyl-containing, alpha,beta-unsaturated chemicals.

    PubMed

    Schultz, T Wayne; Netzeva, Tatiana I; Roberts, David W; Cronin, Mark T D

    2005-02-01

    Toxicity data for 82 aliphatic chemicals with an alpha,beta-unsaturated substructure were compiled. Toxicity was assessed in the 2-day Tetrahymena pyriformis population growth impairment assay. Toxic potency [log(IGC50(-1))] for most of these chemicals was in excess of baseline narcosis as quantified by the 1-octanol/water partition coefficient (log K(ow)). The toxicity of the alpha,beta-unsaturated aldehydes was modeled well by log K(ow) in conjunction with the sum of partial charges on the vinylene carbon atoms (Q(C4) + Q(C3)) and the energy of the lowest unoccupied molecular orbital (E(lumo)). These electronic descriptors were also successful at modeling the toxicity of alpha,beta-unsaturated ketones. The toxicity of a range of acrylates was constant within about 0.2 of a log unit. Conversely, the toxicity of methacrylates and esters containing the vinylene group varied considerably and was explained by their hydrophobicity. The comparison of the quantitative structure-activity relationship (QSAR) for the methacrylates and esters with that for non-polar narcosis showed little significant difference and hence suggested that substitution on the carbon-carbon double bond in the methacrylates and vinylene unsaturated esters does not enhance toxicity over that of baseline. Substitution on the carbon-carbon double bond in the alpha,beta-unsaturated aldehydes resulted in toxicity that was similar to that for saturated derivatives. Although an excellent hydrophobicity-dependent QSAR was developed for the esters containing ethynylene group, these compounds are considered to act as Michael-type acceptors. Attempts to combine different groups of Michael-type acceptors into a single QSAR, based on mechanistically derived descriptors, were unsuccessful. Thus, the modeling of the toxicity of the alpha,beta-unsaturated carbonyl domain is currently limited to models for narrow subdomains. PMID:15720140

  6. Letter: α,ω,N,N-Dimethylaminoalkylamines as possible derivatization agents for the analysis of small carbonyl compounds by low energy mass spectrometry.

    PubMed

    Zhilyaev, Dmitry I; Borisov, Roman S; Polovkov, Nikolai Yu; Zaikin, Vladimir G

    2016-01-01

    Reaction with α,ω-N,N-dimethylaminoalkylamines (2-dimethylaminoethylamine, 3- dimethylaminopropylamine, 4-dimethylaminobutylamine) to form Schiff bases followed by quaternization of the N,N-dimethylamino group by alkyl (deuteroalkyl) halides to generate fixed-charge fragments is suggested for the characterization of carbonyl compounds by matrix-assisted laser desorption ionization (MALDI) mass spectrometry. As model objects, some aliphatic aldehydes and alicyclic and steroid ketones were involved in the modification. Using gas chromatography mass spectrometry, the first modification stage proved to be quantitative. Not only the MALDI conditions but also the nanostructurized target provided spectra that revealed peaks for the cationic parts of derivatives. It was shown that the use of deuterated alkyl halides allows one to prepare deuterium-labeled standards for possible quantitative analysis. PMID:27553738

  7. The detection of the urinary metabolites of 3-[(adamantan-1-yl)carbonyl]-1-pentylindole (AB-001), a novel cannabimimetic, by gas chromatography-mass spectrometry.

    PubMed

    Grigoryev, Andrej; Kavanagh, Pierce; Melnik, Aleksandra

    2012-06-01

    3-[(Adamantan-1-yl)carbonyl]-1-pentylindole (AB-001), a synthetic cannabimimetic, was identified in head shop products in Ireland in 2010. German authorities also reported it to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) via the Early Warning System (EWS) in 2011. As indole-derived cannabimimetics, such as JWH-018, JWH-073, and JWH-250, undergo extensive metabolism, it was expected that AB-001 would behave similarly. To include it in our toxicological screening protocols, we have identified its urinary metabolites in humans following oral administration. The major metabolites were found to be adamantane mono-hydroxylated and adamantane mono-hydroxylated/N-dealkylated products. No parent compound was found in urine, and metabolites were detectable for up to 160 h following administration. PMID:22102533

  8. Unexpected high yields of carbonyl and peroxide products of aqueous isoprene ozonolysis and implications

    NASA Astrophysics Data System (ADS)

    Wang, H. L.; Huang, D.; Zhang, X.; Zhao, Y.; Chen, Z. M.

    2012-03-01

    The aqueous phase reaction of volatile organic compounds (VOCs) has not been considered in most analyses of atmospheric chemical processes. However, some experimental evidence has shown that, compared to the corresponding gas phase reaction, the aqueous chemical processes of VOCs in the bulk solutions and surfaces of ambient wet particles (cloud, fog, and wet aerosols) may potentially contribute to the products and formation of secondary organic aerosol (SOA). In the present study, we performed a laboratory experiment of the aqueous ozonolysis of isoprene at different pHs (3-7) and temperatures (4-25 °C). We detected three important kinds of products, including carbonyl compounds, peroxide compounds, and organic acids. Our results showed that the molar yields of these products were nearly independent of the investigated pHs and temperatures. These products included (1) carbonyls: 56.7 ± 6.7% formaldehyde, 42.8 ± 2.5% methacrolein (MAC), and 57.7 ± 3.4% methyl vinyl ketone (MVK); (2) peroxides: 53.4 ± 4.1% hydrogen peroxide (H2O2) and 15.1 ± 3.1% hydroxylmethyl hydroperoxide (HMHP); and (3) organic acids: undetectable (< 1% estimated by the detection limit). Based on the amounts of products formed and the isoprene consumed, the total carbon yield was estimated to be 95 ± 4%. This implied that most of the products in the reaction system were detected. Of note, the combined yields of both MAC + MVK and H2O2 + HMHP in the aqueous isoprene ozonolysis were much higher than those observed in the corresponding gas phase reaction. We suggested that these unexpected high yields of carbonyls and peroxides were related to the greater capability of condensed water, compared to water vapor, to stabilize energy-rich Criegee radicals. This aqueous ozonolysis of isoprene (and possibly other biogenic VOCs) could potentially occur on the surfaces of ambient wet particles and plants. Moreover, the high-yield carbonyl and peroxide products might provide a considerable source of

  9. A new derivative for oxosteroid analysis by mass spectrometry

    PubMed Central

    Rigdova, K.; Wang, Y.; Ward, M.; Griffiths, W.J.

    2014-01-01

    Here we report a new method for oxosteroid identification utilizing “tandem mass tag hydrazine” (TMTH) carbonyl-reactive derivatisation reagent. TMTH is a reagent with a chargeable tertiary amino group attached through a linker to a carbonyl-reactive hydrazine group. Thirty oxosteroids were analysed after derivatisation with TMTH by electrospray ionization mass spectrometry (ESI-MS) and were found to give high ion-currents compared to underivatised molecules. ESI-tandem mass spectrometry (MS/MS) analysis of the derivatives yielded characteristic fragmentation patterns with specific mass reporter ions derived from the TMT group. A shotgun ESI-MS method incorporating TMTH derivatisation was applied to a urine sample. PMID:24525129

  10. Ferrous Carbonyl Dithiolates as Precursors to FeFe, FeCo, and FeMn Carbonyl Dithiolates

    PubMed Central

    2015-01-01

    Reported are complexes of the formula Fe(dithiolate)(CO)2(diphos) and their use to prepare homo- and heterobimetallic dithiolato derivatives. The starting iron dithiolates were prepared by a one-pot reaction of FeCl2 and CO with chelating diphosphines and dithiolates, where dithiolate = S2(CH2)22– (edt2–), S2(CH2)32– (pdt2–), S2(CH2)2(C(CH3)2)2– (Me2pdt2–) and diphos = cis-C2H2(PPh2)2 (dppv), C2H4(PPh2)2 (dppe), C6H4(PPh2)2 (dppbz), C2H4[P(C6H11)2]2 (dcpe). The incorporation of 57Fe into such building block complexes commenced with the conversion of 57Fe into 57Fe2I4(iPrOH)4, which then was treated with K2pdt, CO, and dppe to give 57Fe(pdt)(CO)2(dppe). NMR and IR analyses show that these complexes exist as mixtures of all-cis and trans-CO isomers, edt2– favoring the former and pdt2– the latter. Treatment of Fe(dithiolate)(CO)2(diphos) with the Fe(0) reagent (benzylideneacetone)Fe(CO)3 gave Fe2(dithiolate)(CO)4(diphos), thereby defining a route from simple ferrous salts to models for hydrogenase active sites. Extending the building block route to heterobimetallic complexes, treatment of Fe(pdt)(CO)2(dppe) with [(acenaphthene)Mn(CO)3]+ gave [(CO)3Mn(pdt)Fe(CO)2(dppe)]+ ([3d(CO)]+). Reduction of [3d(CO)]+ with BH4– gave the Cs-symmetric μ-hydride (CO)3Mn(pdt)(H)Fe(CO)(dppe) (H3d). Complex H3d is reversibly protonated by strong acids, the proposed site of protonation being sulfur. Treatment of Fe(dithiolate)(CO)2(diphos) with CpCoI2(CO) followed by reduction by Cp2Co affords CpCo(dithiolate)Fe(CO)(diphos) (4), which can also be prepared from Fe(dithiolate)(CO)2(diphos) and CpCo(CO)2. Like the electronically related (CO)3Fe(pdt)Fe(CO)(diphos), these complexes undergo protonation to afford the μ-hydrido complexes [CpCo(dithiolate)HFe(CO)(diphos)]+. Low-temperature NMR studies indicate that Co is the kinetic site of protonation. PMID:24803716

  11. Studies Relevent to Catalytic Activation Co & other small Molecules

    SciTech Connect

    Ford, Peter C

    2005-02-22

    Detailed annual and triannual reports describing the progress accomplished during the tenure of this grant were filed with the Program Manager for Catalysis at the Office of Basic Energy Sciences. To avoid unnecessary duplication, the present report will provide a brief overview of the research areas that were sponsored by this grant and list the resulting publications and theses based on this DOE supported research. The scientific personnel participating in (and trained by) this grant's research are also listed. Research carried out under this DOE grant was largely concerned with the mechanisms of the homogeneous catalytic and photocatalytic activation of small molecules such as carbon monoxide, dihydrogen and various hydrocarbons. Much of the more recent effort has focused on the dynamics and mechanisms of reactions relevant to substrate carbonylations by homogeneous organometallic catalysts. A wide range of modern investigative techniques were employed, including quantitative fast reaction methodologies such as time-resolved optical (TRO) and time-resolved infrared (TRIR) spectroscopy and stopped flow kinetics. Although somewhat diverse, this research falls within the scope of the long-term objective of applying quantitative techniques to elucidate the dynamics and understand the principles of mechanisms relevant to the selective and efficient catalytic conversions of fundamental feedstocks to higher value materials.

  12. Scope and Mechanistic Analysis for Chemoselective Hydrogenolysis of Carbonyl Compounds Catalyzed by a Cationic Ruthenium Hydride Complex with a Tunable Phenol Ligand.

    PubMed

    Kalutharage, Nishantha; Yi, Chae S

    2015-09-01

    A cationic ruthenium hydride complex, [(C6H6)(PCy3)(CO)RuH](+)BF4(-) (1), with a phenol ligand was found to exhibit high catalytic activity for the hydrogenolysis of carbonyl compounds to yield the corresponding aliphatic products. The catalytic method showed exceptionally high chemoselectivity toward the carbonyl reduction over alkene hydrogenation. Kinetic and spectroscopic studies revealed a strong electronic influence of the phenol ligand on the catalyst activity. The Hammett plot of the hydrogenolysis of 4-methoxyacetophenone displayed two opposite linear slopes for the catalytic system 1/p-X-C6H4OH (ρ = -3.3 for X = OMe, t-Bu, Et, and Me; ρ = +1.5 for X = F, Cl, and CF3). A normal deuterium isotope effect was observed for the hydrogenolysis reaction catalyzed by 1/p-X-C6H4OH with an electron-releasing group (kH/kD = 1.7-2.5; X = OMe, Et), whereas an inverse isotope effect was measured for 1/p-X-C6H4OH with an electron-withdrawing group (kH/kD = 0.6-0.7; X = Cl, CF3). The empirical rate law was determined from the hydrogenolysis of 4-methoxyacetophenone: rate = kobsd[Ru][ketone][H2](-1) for the reaction catalyzed by 1/p-OMe-C6H4OH, and rate = kobsd[Ru][ketone][H2](0) for the reaction catalyzed by 1/p-CF3-C6H4OH. Catalytically relevant dinuclear ruthenium hydride and hydroxo complexes were synthesized, and their structures were established by X-ray crystallography. Two distinct mechanistic pathways are presented for the hydrogenolysis reaction on the basis of these kinetic and spectroscopic data. PMID:26235841

  13. Carbonyl compounds in dining areas, kitchens and exhaust streams in restaurants with varying cooking methods in Kaohsiung, Taiwan.

    PubMed

    Cheng, Jen-Hsuan; Lee, Yi-Shiun; Chen, Kang-Shin

    2016-03-01

    Eighteen carbonyl species in C1-C10 were measured in the dining areas, kitchens and exhaust streams of six different restaurant types in Kaohsiung, southern Taiwan. Measured results in the dining areas show that Japanese barbecue (45.06ppb) had the highest total carbonyl concentrations (sum of 18 compounds), followed by Chinese hotpot (38.21ppb), Chinese stir-frying (8.99ppb), Western fast-food (8.22ppb), Chinese-Western mixed style (7.38ppb), and Chinese buffet (3.08ppb), due to their different arrangements for dining and cooking spaces and different cooking methods. On average, low carbon-containing species (C1-C4), e.g., formaldehyde, acetaldehyde, acetone and butyraldehyde were dominant and contributed 55.01%-94.52% of total carbonyls in the dining areas of all restaurants. Meanwhile, Chinese-Western mixed restaurants (45.48ppb) had high total carbonyl concentrations in kitchens mainly because of its small kitchen and poor ventilation. However, high carbon-containing species (C5-C10) such as hexaldehyde, heptaldehyde and nonanaldehyde (16.62%-77.00% of total carbonyls) contributed comparatively with low carbon-containing compounds (23.01%-83.39% of total carbonyls) in kitchens. Furthermore, Chinese stir-frying (132.10ppb), Japanese barbecue (125.62ppb), Western fast-food (122.67ppb), and Chinese buffet (119.96ppb) were the four restaurant types with the highest total carbonyl concentrations in exhaust streams, indicating that stir-frying and grilling are inclined to produce polluted gases. Health risk assessments indicate that Chinese hotpot and Japanese barbecue exceeded the limits of cancer risk (10(-6)) and hazard index (=1), mainly due to high concentrations of formaldehyde. The other four restaurants were below both limits. PMID:26969068

  14. Sol–gel method as a way of carbonyl iron powder surface modification for interaction improvement

    SciTech Connect

    Małecki, P.; Kolman, K.; Pigłowski, J.; Kaleta, J.; Krzak, J.

    2015-03-15

    This article presents a method for modification of carbonyl iron particles’ surface (CIP), (d{sub 50}=4–9 µm) by silica coatings obtained using the sol–gel method. Reaction parameters were determined to obtain dry magnetic powder with homogeneous silica coatings without further processing and without any by-product in the solid or liquid phase. This approach is new among the commonly used methods of silica coating of iron particles. No attempt has been made to cover a carbonyl iron surface by silica in a waste-free method, up to date. In the current work two different silica core/shell structures were made by the sol–gel process, based on different silica precursors: tetraethoxy-silane (TEOS) and tetramethoxy-silane (TMOS). The dependence between the synthesis procedure and thickness of silica shell covering carbonyl iron particles has been described. Surface morphology of the modified magnetic particles and the coating thickness were characterized with the use of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Determination of the physicochemical structure of the obtained materials was performed by the energy-dispersive X-ray spectroscope (EDS), and the infrared technique (IR). The surface composition was analyzed using X-ray photoelectron spectroscopy (XPS). Additionally, distribution of particle size was measured using light microscopy. The new, efficient process of covering micro-size CIP with a nanometric silica layer was shown. Results of a performed analysis confirm the effectiveness of the presented method. - Highlights: • Proper covering CIP by sol–gel silica layer avoids agglomeration. • A new solid waste-free method of CIP coating is proposed. • Examination of the properties of modified CIP in depends on washing process. • Coatings on CIP particles doesn’t change the magnetic properties of particles.

  15. Redox Proteomic Profiling of Specifically Carbonylated Proteins in the Serum of Triple Transgenic Alzheimer's Disease Mice.

    PubMed

    Shen, Liming; Chen, Youjiao; Yang, Aochu; Chen, Cheng; Liao, Liping; Li, Shuiming; Ying, Ming; Tian, Jing; Liu, Qiong; Ni, Jiazuan

    2016-01-01

    Oxidative stress is a key event in the onset and progression of neurodegenerative diseases, including Alzheimer's disease (AD). To investigate the role of oxidative stress in AD and to search for potential biomarkers in peripheral blood, serums were collected in this study from the 3-, 6-, and 12-month-old triple transgenic AD mice (3×Tg-AD mice) and the age- and sex-matched non-transgenic (non-Tg) littermates. The serum oxidized proteins were quantified by slot-blot analysis and enzyme-linked immunosorbent assay (ELISA) to investigate the total levels of serum protein carbonyl groups. Western blotting, in conjunction with two-dimensional gel electrophoresis (2D-Oxyblot), was employed to identify and quantify the specifically-carbonylated proteins in the serum of 3×Tg-AD mice. The results showed that the levels of serum protein carbonyls were increased in the three month old 3×Tg-AD mice compared with the non-Tg control mice, whereas no significant differences were observed in the six and 12 months old AD mice, suggesting that oxidative stress is an early event in AD progression. With the application of 2D-Oxyblot analysis, (immunoglobin) Ig gamma-2B chain C region (IGH-3), Ig lambda-2 chain C region (IGLC2), Ig kappa chain C region (IGKC), and Ig kappa chain V-V region HP R16.7 were identified as significantly oxidized proteins compared with the control. Among them IGH-3 and IGKC were validated via immunoprecipitation and Western blot analysis. Identification of oxidized proteins in the serums of 3×Tg-AD mice can not only reveal potential roles of those proteins in the pathogenesis of AD but also provide potential biomarkers of AD at the early stage. PMID:27077851

  16. Formation and emissions of carbonyls during and following gas-phase ozonation of indoor materials

    NASA Astrophysics Data System (ADS)

    Poppendieck, D. G.; Hubbard, H. F.; Weschler, C. J.; Corsi, R. L.

    Ozone concentrations that are several orders of magnitude greater than typical urban ambient concentrations are necessary for gas-phase ozonation of buildings, either for deodorization or for disinfection of biological agents. However, there is currently no published literature on the interaction of building materials and ozone under such extreme conditions. It would be useful to understand, for example in the case of building re-occupation planning, what types and amounts of reaction products may form and persist in a building after ozonation. In this study, 24 materials were exposed to ozone at concentrations of 1000 ppm in the inlet stream of experimental chambers. Fifteen target carbonyls were selected and measured as building ozonation by-products (BOBPs). During the 36 h that include the 16 h ozonation and 20 h persistence phase, the total BOBP mass released from flooring and wall coverings ranged from 1 to 20 mg m -2, with most of the carbonyls being of lower molecular weight (C 1-C 4). In contrast, total BOBP mass released from wood-based products ranged from 20 to 100 mg m -2, with a greater fraction of the BOBPs being heavier carbonyls (C 5-C 9). The total BOBP mass released during an ozonation event is a function of both the total surface area of the material and the BOBP emission rate per unit area of material. Ceiling tile, carpet, office partition, and gypsum wallboard with flat latex paint often have large surface areas in commercial buildings and these same materials exhibited relatively high BOBP releases. The greatest overall BOBP mass releases were observed for three materials that building occupants might have significant contact with: paper, office partition, and medium density fiberboard, e.g., often used in office furniture. These materials also exhibited extended BOBP persistence following ozonation; some BOBPs (e.g., nonanal) persist for months or more at emission rates large enough to result in indoor concentrations that exceed their odor

  17. Synthesis and Evaluation of in Vitro Bioactivity for Vesicular Acetylcholine Transporter Inhibitors Containing Two Carbonyl Groups

    PubMed Central

    Tu, Zhude; Wang, Wei; Cui, Jinquan; Zhang, Xiang; Lu, Xiaoxia; Xu, Jinbin; Parsons, Stanley M.

    2012-01-01

    To identify selective high-affinity ligands for the vesicular acetylcholine transporter (VAChT), we have incorporated a carbonyl group into the structures of trozamicol and prezamicol scaffolds, and also converted the secondary amines of the piperidines of trozamicols and prezamicols into amides. Of 18 new racemic compounds, 4 compounds displayed high affinity for VAChT (Ki = 10 - 20 nM) and greater than 300-fold selectivity for VAChT over σ1 and σ2 receptors, namely (4-(4-fluorobenzoyl)-4'-hydroxy-[1,3'-bipiperidin]-1'-yl)(3-methylthiophen-2-yl)methanone oxalate (9g) (Ki-VAChT = 11.4 nM, VAChT/σ1 = 1063, VAChT/σ2 = 370), (1'-benzoyl-4'-hydroxy-[1,3'-bipiperidin]-4-yl)(4-methoxyphenyl)methanone oxalate (10c) (Ki-VAChT = 15.4 nM, VAChT/σ1 = 374, VAChT/ σ2 = 315), (4'-hydroxy-1'-(thiophene-2-carbonyl)-[1,3'-bipiperidin]-4-yl)(4-methoxyphenyl)methanone oxalate (10e) (Ki-VAChT = 19.0 nM, VAChT/σ1 = 1787, VAChT/ σ2 = 335), and (4'-hydroxy-1'-(3-methylthiophene-2-carbonyl)-[1,3'-bipiperidin]-4-yl)(4-methoxyphenyl)methanone oxalate (10g) (Ki-VAChT = 10.2 nM, VAChT/σ1 = 1500, VAChT/ σ2 = 2030). These 4 compounds can be radiosynthesized with C-11 or F-18 to validate their possibilities of serving as PET probes for quantifying the levels of VAChT in vivo. PMID:22739089

  18. On the satisfaction of backbone‐carbonyl lone pairs of electrons in protein structures

    PubMed Central

    2016-01-01

    Abstract Protein structures are stabilized by a variety of noncovalent interactions (NCIs), including the hydrophobic effect, hydrogen bonds, electrostatic forces and van der Waals’ interactions. Our knowledge of the contributions of NCIs, and the interplay between them remains incomplete. This has implications for computational modeling of NCIs, and our ability to understand and predict protein structure, stability, and function. One consideration is the satisfaction of the full potential for NCIs made by backbone atoms. Most commonly, backbone‐carbonyl oxygen atoms located within α‐helices and β‐sheets are depicted as making a single hydrogen bond. However, there are two lone pairs of electrons to be satisfied for each of these atoms. To explore this, we used operational geometric definitions to generate an inventory of NCIs for backbone‐carbonyl oxygen atoms from a set of high‐resolution protein structures and associated molecular‐dynamics simulations in water. We included more‐recently appreciated, but weaker NCIs in our analysis, such as n→π* interactions, Cα‐H bonds and methyl‐H bonds. The data demonstrate balanced, dynamic systems for all proteins, with most backbone‐carbonyl oxygen atoms being satisfied by two NCIs most of the time. Combinations of NCIs made may correlate with secondary structure type, though in subtly different ways from traditional models of α‐ and β‐structure. In addition, we find examples of under‐ and over‐satisfied carbonyl‐oxygen atoms, and we identify both sequence‐dependent and sequence‐independent secondary‐structural motifs in which these reside. Our analysis provides a more‐detailed understanding of these contributors to protein structure and stability, which will be of use in protein modeling, engineering and design. PMID:26833776

  19. Deep-blue phosphorescence from perfluoro carbonyl-substituted iridium complexes.

    PubMed

    Lee, Sunghun; Kim, Seul-Ong; Shin, Hyun; Yun, Hui-Jun; Yang, Kiyull; Kwon, Soon-Ki; Kim, Jang-Joo; Kim, Yun-Hi

    2013-09-25

    The new deep-blue iridium(III) complexes, (TF)2Ir(pic), (TF)2Ir(fptz), (HF)2Ir(pic), and (HF)2Ir(fptz), consisting of 2',4″-difluororphenyl-3-methylpyridine with trifluoromethyl carbonyl or heptafluoropropyl carbonyl at the 3' position as the main ligand and a picolinate or a trifluoromethylated-triazole as the ancillary ligand, were synthesized and characterized for applications in organic light-emitting diodes (OLEDs). Density function theory (DFT) calculations showed that these iridium complexes had a wide band gap, owing to the introduction of the strong electron withdrawing perfluoro carbonyl group. Time-dependent DFT (TD-DFT) calculations suggested that their lowest triplet excited state was dominated by a HOMO → LUMO transition and that the contribution of the metal-to-ligand charge transfer (MLCT) was higher than 34% for all four complexes, indicating that strong spin-orbit coupling exists in the complexes. The 10 wt % (TF)2Ir(pic) doped 9-(3-(9H-carbazole-9-yl)phenyl)-3-(dibromophenylphosphoryl)-9H-carbazole (mCPPO1) film exhibited the highest photoluminescence quantum yield of 74 ± 3% among the films based on the four complexes. Phosphorescent OLEDs based on (TF)2Ir(pic) and (TF)2Ir(fptz) exhibited maximum external quantum efficiencies of 17.1% and 8.4% and Commission Internationale de l'Eclairage (CIE) coordinates of (0.141, 0.158) and (0.147, 0.116), respectively. These CIE coordinates represent some of the deepest blue emissions ever achieved from phosphorescent OLEDs with considerably high EQEs. PMID:23998654

  20. Carbonylation Induces Heterogeneity in Cardiac Ryanodine Receptor Function in Diabetes Mellitus

    PubMed Central

    Shao, Chun Hong; Tian, Chengju; Ouyang, Shouqiang; Moore, Caronda J.; Alomar, Fadhel; Nemet, Ina; D'Souza, Alicia; Nagai, Ryoji; Kutty, Shelby; Rozanski, George J.; Ramanadham, Sasanka; Singh, Jaipaul

    2012-01-01

    Heart failure and arrhythmias occur at 3 to 5 times higher rates among individuals with diabetes mellitus, compared with age-matched, healthy individuals. Studies attribute these defects in part to alterations in the function of cardiac type 2 ryanodine receptors (RyR2s), the principal Ca2+-release channels on the internal sarcoplasmic reticulum (SR). To date, mechanisms underlying RyR2 dysregulation in diabetes remain poorly defined. A rat model of type 1 diabetes, in combination with echocardiography, in vivo and ex vivo hemodynamic studies, confocal microscopy, Western blotting, mass spectrometry, site-directed mutagenesis, and [3H]ryanodine binding, lipid bilayer, and transfection assays, was used to determine whether post-translational modification by reactive carbonyl species (RCS) represented a contributing cause. After 8 weeks of diabetes, spontaneous Ca2+ release in ventricular myocytes increased ∼5-fold. Evoked Ca2+ release from the SR was nonuniform (dyssynchronous). Total RyR2 protein levels remained unchanged, but the ability to bind the Ca2+-dependent ligand [3H]ryanodine was significantly reduced. Western blotting and mass spectrometry revealed RCS adducts on select basic residues. Mutation of residues to delineate the physiochemical impact of carbonylation yielded channels with enhanced or reduced cytoplasmic Ca2+ responsiveness. The prototype RCS methylglyoxal increased and then decreased the RyR2 open probability. Methylglyoxal also increased spontaneous Ca2+ release and induced Ca2+ waves in healthy myocytes. Treatment of diabetic rats with RCS scavengers normalized spontaneous and evoked Ca2+ release from the SR, reduced carbonylation of RyR2s, and increased binding of [3H]ryanodine to RyR2s. From these data, we conclude that post-translational modification by RCS contributes to the heterogeneity in RyR2 activity that is seen in experimental diabetes. PMID:22648972

  1. CO-releasing Metal Carbonyl Compounds as Antimicrobial Agents in the Post-antibiotic Era*

    PubMed Central

    Wareham, Lauren K.; Poole, Robert K.; Tinajero-Trejo, Mariana

    2015-01-01

    The possibility of a “post-antibiotic era” in the 21st century, in which common infections may kill, has prompted research into radically new antimicrobials. CO-releasing molecules (CORMs), mostly metal carbonyl compounds, originally developed for therapeutic CO delivery in animals, are potent antimicrobial agents. Certain CORMs inhibit growth and respiration, reduce viability, and release CO to intracellular hemes, as predicted, but their actions are more complex, as revealed by transcriptomic datasets and modeling. Progress is hindered by difficulties in detecting CO release intracellularly, limited understanding of the biological chemistry of CO reactions with non-heme targets, and the cytotoxicity of some CORMs to mammalian cells. PMID:26055702

  2. Multiband microwave absorption films based on defective multiwalled carbon nanotubes added carbonyl iron/acrylic resin

    NASA Astrophysics Data System (ADS)

    Li, Yong; Chen, Changxin; Pan, Xiaoyan; Ni, Yuwei; Zhang, Song; Huang, Jie; Chen, Da; Zhang, Yafei

    2009-05-01

    Defective multiwalled carbon nanotubes (MWCNTs) were introduced to the carbonyl iron (CI) based composites to improve its microwave absorption by a simple ultrasonic mixing process. The electromagnetic parameters were measured in the 2-18 GHz range. Microwave absorption of CI based composites with 2 mm in thickness was evidently enhanced by adding as little as 1.0 wt% defective MWCNTs with two well separated absorption peaks exceeding -20 dB, as compared with that of pure CI based and defective MWCNTs composites. The enhancement mechanism is thought due to the interaction and better electromagnetic match between defective MWCNTs and ferromagnetic CI particles.

  3. Inhibition of protein carbonyl formation and lipid peroxidation by glutathione in rat liver microsomes.

    PubMed

    Palamanda, J R; Kehrer, J P

    1992-02-14

    The peroxidation of rat liver microsomal lipids is stimulated in the presence of iron by the addition of NADPH or ascorbate and is inhibited by the addition of glutathione (GSH). The fate of GSH and the oxidative modification of proteins under these conditions have not been well studied. Rat liver microsomes were incubated at 37 degrees C under 95% O2:5% CO2 in the presence of 10 microM ferric chloride, 400 microM ADP, and either 450 microM ascorbic acid or 400 microM NADPH. Lipid peroxidation was assessed in the presence 0, 0.2, 0.5, 1, or 5 mM GSH by measuring thiobarbituric acid reactive substance (TBARS) and oxidative modification of proteins by measuring protein thiol and carbonyl groups. GSH inhibited TBARS and protein carbonyl group formation in both ascorbate and NADPH systems in a dose-dependent manner. Heat denaturing of microsomes or treatment with trypsin resulted in the loss of this protection. The formation of protein carbonyl groups could be duplicated by incubating microsomes with 4-hydroxynonenal. Ascorbate-dependent peroxidation caused a loss of protein thiol groups which was diminished by GSH only in fresh microsomes. Both boiling and trypsin treatment significantly decreased the basal protein thiol content of microsomes and enhanced ascorbate-stimulated lipid peroxidation. Protection against protein carbonyl group formation by GSH correlated with the inhibition of lipid peroxidation and appeared not to be due to the formation of the GSH conjugate of 4-hydroxynonenal as only trace amounts of this conjugate were detected. Ninety percent of the GSH lost after 60 min of peroxidation was recoverable as borohydride reducible material in the supernatant fraction. The remaining 10% could be accounted for as GSH-bound protein mixed disulfides. However, only 75% of the GSH lost during peroxidation appeared as glutathione disulfide, suggesting that some was converted to other soluble borohydride reducible forms. These data support a role for protein thiol

  4. Pd/C Catalyzed Carbonylation of Azides in the Presence of Amines.

    PubMed

    Zhao, Jin; Li, Zongyang; Yan, Shuaihu; Xu, Shiyang; Wang, Ming-An; Fu, Bin; Zhang, Zhenhua

    2016-04-15

    A facile and efficient Pd/C-catalyzed carbonylation of both aliphatic and aromatic azides in the presence of amines is reported. Serving as the widely existed fragments in an array of biological pharmaceuticals, functionalized unsymmetrical ureas were straightforwardly synthesized by using readily available and cheap azides with amines under CO atmosphere, with the extrusion of N2 as the only byproduct. It was found that not only aryl azides but also benzyl and alkyl azides were suited for this methodology. Another feature of this procedure was the employment of a highly efficient palladium charcoal catalytic system. PMID:27015001

  5. Self-assembly of graphene oxide coated soft magnetic carbonyl iron particles and their magnetorheology

    SciTech Connect

    Zhang, W. L.; Choi, H. J.

    2014-05-07

    The surface of carbonyl iron (CI) microspheres was modified with graphene oxide (GO) as a coating material using 4-aminobenzoic acid as the grafting agent. The morphology, elemental composition, and magnetic properties of the GO-coated CI (GO/CI) particles were examined by scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry, respectively, confirming their composite formation. The magnetorheological (MR) performance of the GO/CI particle-based suspension was examined using a rotational rheometer connected to a magnetic field supply. The GO/CI particles suspension exhibited typical MR properties with increasing shear stress and viscosity depending on the applied magnetic field strength.

  6. Performance of diffusion Monte Carlo for the first dissociation energies of transition metal carbonyls

    NASA Astrophysics Data System (ADS)

    Diedrich, Christian; Lüchow, Arne; Grimme, Stefan

    2005-01-01

    Fixed node diffusion Monte Carlo (FNDMC) calculations are carried out for the first ligand dissociation energies of the prototype transition metal carbonyls Cr(CO)6, Fe(CO)5, Ni(CO)4, and Fe(CO)4N2. Since Hartree-Fock theory performs particularly badly for these type of compounds they are difficult to treat with conventional ab initio methods. We find that a Kohn-Sham determinant from a standard density functional provides a balanced description of the fermionic nodal hyper surfaces of all compounds involved in the dissociation reaction. With one exception, the experimental dissociation enthalpies are reproduced by FNDMC within the statistical accuracy of the method.

  7. Carbonyl sulfide detection with a thermoelectrically cooled midinfrared quantum cascade laser

    NASA Astrophysics Data System (ADS)

    Roller, Chad; Kosterev, Anatoliy A.; Tittel, Frank K.; Uehara, Kiyoji; Gmachl, Claire; Sivco, Deborah L.

    2003-11-01

    A compact absorption spectrometer with a midinfrared tunable quantum cascade laser operating at 4.86 μm (2054 cm-1) is used to measure lower concentrations of carbonyl sulfide (COS) in air. A detection sensitivity of ~30 parts in 109 of COS and the selectivity of two stable isotopes, 12C16O32S and 12C16O34S, are demonstrated. Specifically, the feasibility of detecting COS in expired human breath as a potential noninvasive medical diagnostic tool is investigated.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Rapid synthesis of radioactive transition-metal carbonyl complexes at ambient conditions.

    PubMed

    Even, Julia; Yakushev, Alexander; Düllmann, Christoph E; Dvorak, Jan; Eichler, Robert; Gothe, Oliver; Hild, Daniel; Jäger, Egon; Khuyagbaatar, Jadambaa; Kratz, Jens V; Krier, Jörg; Niewisch, Lorenz; Nitsche, Heino; Pysmenetska, Inna; Schädel, Matthias; Schausten, Brigitta; Türler, Andreas; Wiehl, Norbert; Wittwer, David

    2012-06-18

    Carbonyl complexes of radioactive transition metals can be easily synthesized with high yields by stopping nuclear fission or fusion products in a gas volume containing CO. Here, we focus on Mo, W, and Os complexes. The reaction takes place at pressures of around 1 bar at room temperature, i.e., at conditions that are easy to accommodate. The formed complexes are highly volatile. They can thus be transported within a gas stream without major losses to setups for their further investigation or direct use. The rapid synthesis holds promise for radiochemical purposes and will be useful for studying, e.g., chemical properties of superheavy elements. PMID:22663355

  10. An air-tolerant approach to the carbonylative Suzuki-Miyaura coupling: applications in isotope labeling.

    PubMed

    Ahlburg, Andreas; Lindhardt, Anders T; Taaning, Rolf H; Modvig, Amalie E; Skrydstrup, Troels

    2013-10-18

    Carbonylative Suzuki-Miyaura coupling conditions have been developed that proceed without the exclusion of oxygen and in the presence of nondegassed and nondried solvents. By adapting the method to a two-chamber setup, the direct handling of carbon monoxide, produced from stable CO precursors, is avoided. The protocol afforded the desired benzophenones with excellent functional group tolerance and in good yields. Substituting the CO precursor, in the CO-producing chamber, with its carbon-13 labeled version generated the corresponding carbon-13 labeled benzophenones. Finally, the developed system was applied in the synthesis and isotope labeling of two pharmaceuticals, nordazepam and Tricor. PMID:24004340

  11. N,N-Dicarboxymethyl hydrazine: an old but neglected reagent for chemoselective derivatization of carbonyl compounds.

    PubMed

    Zhen, Maomin; Peng, Yanqing

    2016-04-01

    N,N-Dicarboxymethyl hydrazine (DCMH) was found to be a chemoselective derivatization reagent of carbonyl compounds and its potential applications in organic synthesis was investigated for the first time. DCMH could be employed as a chemoselective protective reagent of aldehydes and gave the parent aldehydes in satisfactory yields. In proof-of-concept systems, DCMH could play the role of a scavenger to remove aldehydes in the presence of ketones. It was also used as a tagging reagent in the selective isolation of aldehyde from the complex mixture. PMID:26964753

  12. Ischemia-reperfusion rat model of acute pancreatitis: protein carbonyl as a putative early biomarker of pancreatic injury.

    PubMed

    Schanaider, Alberto; de Carvalho, Thales Penna; de Oliveira Coelho, Simone; Renteria, Juan Miguel; Eleuthério, Elis Cristina Araújo; Castelo-Branco, Morgana Teixeira Lima; Madi, Kalil; Baetas-da-Cruz, Wagner; de Souza, Heitor Siffert Pereira

    2015-08-01

    Acute pancreatitis (AP) is an inflammatory disorder that can affect adjacent and/or remote organs. Some evidence indicates that the production of reactive oxygen species is able to induce AP. Protein carbonyl (PC) derivatives, which can also be generated through oxidative cleavage mechanisms, have been implicated in several diseases, but there is little or no information on this biomarker in AP. We investigated the association between some inflammatory mediators and PC, with the severity of ischemia-reperfusion AP. Wistar rats (n = 56) were randomly assigned in the following groups : control; sham, 15- or 180-min clamping of splenic artery, with 24 or 72 h of follow-up. The relationships between serum level of PC and thiobarbituric acid reactive species (TBARS) to myeloperoxidase (MPO) activity in tissue homogenates and to cytokines in culture supernatants of pancreatic samples were analyzed. MPO activity was related to the histology scores and increased in all clamping groups. Tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin-6 were higher in the 180-min groups. Significant correlations were found between MPO activity and the concentrations of TNF-α and IL-1β. PC levels increased in the 15-min to 24-h group. TBARS levels were not altered substantially. MPO activity and TNF-α and IL-1β concentrations in pancreatic tissue are correlated with AP severity. Serum levels of PC appear to begin to rise early in the course of the ischemia-reperfusion AP and are no longer detected at later stages in the absence of severe pancreatitis. These data suggest that PC can be an efficient tool for the diagnosis of early stages of AP. PMID:24934325

  13. Carbonyl emission and toxicity profile of diesel blends with an animal-fat biodiesel and a tire pyrolysis liquid fuel.

    PubMed

    Ballesteros, R; Guillén-Flores, J; Martínez, J D

    2014-02-01

    In this paper, two diesel fuels, an animal-fat biodiesel and two diesel blends with the animal-fat biodiesel (50vol.%) and with a tire pyrolysis liquid (TPL) fuel (5vol.%) have been tested in a 4-cylinder, 4-stroke, turbocharged, intercooled, 2.0L Nissan diesel automotive engine (model M1D) with common-rail injection system and diesel oxidation catalyst (DOC). Carbonyl emissions have been analyzed both before and after DOC and specific reactivity of carbonyl profile has been calculated. Carbonyl sampling was carried out by means of a heated line, trapping the gas in 2,4-DNPH cartridges. The eluted content was then analyzed in an HPLC system, with UV-VIS detection. Results showed, on the one hand, an increase in carbonyl emissions with the biodiesel fraction in the fuel. On the other hand, the addition of TPL to diesel also increased carbonyl emissions. These trends were occasionally different if the emissions were studied after the DOC, as it seems to be selectivity during the oxidation process. The specific reactivity was also studied, finding a decrease with the oxygen content within the fuel molecule, although the equivalent ozone emissions slightly increased with the oxygen content. Finally, the emissions toxicity was also studied, comparing them to different parameters defined by different organizations. Depending on the point of study, emissions were above or below the established limits, although acrolein exceeded them as it has the least permissive values. PMID:24184046

  14. Cytoprotective Effects of Hydrophilic and Lipophilic Extracts of Pistacia vera against Oxidative Versus Carbonyl Stress in Rat Hepatocytes.

    PubMed

    Shahraki, Jafar; Zareh, Mona; Kamalinejad, Mohammad; Pourahmad, Jalal

    2014-01-01

    This study was conducted to evaluate the cytoprotection of various extracts and bioactive compounds found in Pistacia vera againts cytotoxicity, ROS formation, lipid peroxidation, protein carbonylation, mitochondrial and lysosomal membrane damages in cell toxicity models of diabetes related carbonyl (glyoxal) and oxidative stress (hydroperoxide). Methanol, water and ethyl acetate were used to prepare crude pistachios extracts, which were then used to screen for in-vitro cytoprotection of freshly isolated rat hepatocytes against these toxins. The order of protection by Pistacia vera extracts against both hydroperoxide induced oxidative stress (ROS formation) and glyoxal induced protein carbonylation was: pistachio methanolic extract >pistachio water extract, gallic acid, catechin> α-tochoferol and pistachio ethyl acetate extract. Finally due to higher protection achieved by methanolic extract even compared to sole pretreatment of gallic acid, catechin or α-tochoferol, we suggest that cytoprotection depends on the variety of polar and non-polar compounds found in methanolic extract, it is likely that multiple cytoprotective mechanisms are acting against oxidative and carbonyl induced cytotoxicity. To our knowledge, we are the first to report the cytoprotective activity of Pistacia vera extracts against oxidative and carbonyl stress seen in type 2 diabetes hepatocytes model. PMID:25587316

  15. Cytoprotective Effects of Hydrophilic and Lipophilic Extracts of Pistacia vera against Oxidative Versus Carbonyl Stress in Rat Hepatocytes

    PubMed Central

    Shahraki, Jafar; Zareh, Mona; Kamalinejad, Mohammad; Pourahmad, Jalal

    2014-01-01

    This study was conducted to evaluate the cytoprotection of various extracts and bioactive compounds found in Pistacia vera againts cytotoxicity, ROS formation, lipid peroxidation, protein carbonylation, mitochondrial and lysosomal membrane damages in cell toxicity models of diabetes related carbonyl (glyoxal) and oxidative stress (hydroperoxide). Methanol, water and ethyl acetate were used to prepare crude pistachios extracts, which were then used to screen for in-vitro cytoprotection of freshly isolated rat hepatocytes against these toxins. The order of protection by Pistacia vera extracts against both hydroperoxide induced oxidative stress (ROS formation) and glyoxal induced protein carbonylation was: pistachio methanolic extract >pistachio water extract, gallic acid, catechin> α-tochoferol and pistachio ethyl acetate extract. Finally due to higher protection achieved by methanolic extract even compared to sole pretreatment of gallic acid, catechin or α-tochoferol, we suggest that cytoprotection depends on the variety of polar and non-polar compounds found in methanolic extract, it is likely that multiple cytoprotective mechanisms are acting against oxidative and carbonyl induced cytotoxicity. To our knowledge, we are the first to report the cytoprotective activity of Pistacia vera extracts against oxidative and carbonyl stress seen in type 2 diabetes hepatocytes model. PMID:25587316

  16. An ab initio study of the influence of substituents and intramolecular hydrogen bonding on the carbonyl bond length, and the harmonic and anharmonic stretching force constants. I. Monosubstituted carbonyl compounds

    NASA Astrophysics Data System (ADS)

    Bock, Charles W.; Trachtman, Mendel; George, Philip

    1981-11-01

    The CO bond length and the quadratic, cubic and quartic stretching force constants, calculated ab initio using the unscaled 4-31G basis set with full geometry optimization, are reported for three series of monosubstituted carbonyl compounds in which the atom directly bonded to the carbonyl carbon is another carbon, a nitrogen, or an oxygen atom, respectively. The data are analyzed in terms of the In ƒ versus In re relationship, and also the generalized power functions and exponential functions proposed by Herschbach and Laurie. Not only does the atom directly bonded to the carbonyl carbon affect the magnitude of re and the force constants, but the rest of the substituent group is found to be capable of exerting an even greater influence. Within each series of compounds the overall progression from the shortest to the longest CO bonds is tentatively attributed to a diminishing electron density in the bonding region.

  17. Comparative Proteomic Analysis of Carbonylated Proteins from the Striatum and Cortex of Pesticide-Treated Mice.

    PubMed

    Coughlan, Christina; Walker, Douglas I; Lohr, Kelly M; Richardson, Jason R; Saba, Laura M; Caudle, W Michael; Fritz, Kristofer S; Roede, James R

    2015-01-01

    Epidemiological studies indicate exposures to the herbicide paraquat (PQ) and fungicide maneb (MB) are associated with increased risk of Parkinson's disease (PD). Oxidative stress appears to be a premier mechanism that underlies damage to the nigrostriatal dopamine system in PD and pesticide exposure. Enhanced oxidative stress leads to lipid peroxidation and production of reactive aldehydes; therefore, we conducted proteomic analyses to identify carbonylated proteins in the striatum and cortex of pesticide-treated mice in order to elucidate possible mechanisms of toxicity. Male C57BL/6J mice were treated biweekly for 6 weeks with saline, PQ (10 mg/kg), MB (30 mg/kg), or the combination of PQ and MB (PQMB). Treatments resulted in significant behavioral alterations in all treated mice and depleted striatal dopamine in PQMB mice. Distinct differences in 4-hydroxynonenal-modified proteins were observed in the striatum and cortex. Proteomic analyses identified carbonylated proteins and peptides from the cortex and striatum, and pathway analyses revealed significant enrichment in a variety of KEGG pathways. Further analysis showed enrichment in proteins of the actin cytoskeleton in treated samples, but not in saline controls. These data indicate that treatment-related effects on cytoskeletal proteins could alter proper synaptic function, thereby resulting in impaired neuronal function and even neurodegeneration. PMID:26345149

  18. Heterogeneous catalysts for the direct, Halide-free carbonylation of methanol

    SciTech Connect

    Ellis, B.; Smith, W.J.; Howard, M.J.

    1996-12-31

    Copper containing mordenite catalysts (Cu-MOR) have been shown to be active and selective for the carbonylation of methanol under moderate conditions in the vapour phase and in the absence of any halide promoter. This paper describes the preparation, performance and in particular the characterization of this class of catalyst, comparing its performance with H-mordenite, which is also shown to be active in the carbonylation reaction. Initially both Cu-MOR and H-MOR catalyst methanol to gasoline (MTG) chemistry, but after about 6 hours on stream under typical conditions, (T = 623 K, p = 10 bar, CO: methanol ratio ca 10:1) acetic acid becomes the main product over Cu-MOR. Selectivity to acetyls (acetic acid + methyl acetate) remains at > 70% for ca 12 hours but gradually declines, giving way to the formation of dimethyl ether. H-MOR shows similar trends, but the period when MTG chemistry is observed is longer and that where acetyls are formed is shorter. Initially Cu(II) ions are distributed throughout the mordenite pore structure, but by the time activity to acetyls is observed the pore structure has largely become blocked by polymethyl benzenes, and much of the copper has become aggregated into large metal particles (d > 120 {Angstrom}). However FTIR studies using carbon monoxide as a probe molecule show that some non-zerovalent copper ions are still accessible. Structure - function relationships for these interesting materials are discussed briefly.

  19. Behavior of VOCs and carbonyl compounds emission from different types of wallpapers in Korea.

    PubMed

    Lim, Jungyun; Kim, Suejin; Kim, Arong; Lee, Wooseok; Han, Jinseok; Cha, Jun-Seok

    2014-04-01

    Emissions of volatile organic compounds (VOCs) and carbonyls from three types of commercially available wallpapers (i.e., PVC-coated, paper-backed, natural material-coated) in Korea were evaluated using a 20 L small chamber. A total of 332 products were tested for emission factors, frequencies of occurrence and composition ratios. Toluene and formaldehyde concentrations were below Korean standard values for all products; however, the total VOC (TVOC) concentrations exceeded current standards (4.0 mg/m²·h) for 30 products. The TVOC emission factor for PVC-coated wallpapers, for which polymer materials are used in the manufacturing process, was seven and 16 times higher than those of paper-backed and natural material-coated wallpapers, respectively. The detection frequencies for toluene and formaldehyde were the highest (82.5%) and fourth highest (79.5%), respectively among the 50 target chemical species. The composition ratios for BTEX ranged from 0.3% to 5.1% and unidentified VOCs, which were not qualitatively analyzed using standard gas methods, ranged from 90.2% to 94.8%. Among six carbonyl compounds (acrolein was not detected in any type of wallpaper), acetone had the highest concentrations in PVC-coated (44.6%) and paper-backed (66.6%) wallpapers. Formaldehyde emissions were highest (64.6%) for natural material-coated wallpapers, a result of the formaldehyde-based resin used in the manufacturing process for these products. PMID:24747540

  20. Carbonylation as a separation technique for removal of non-radioactive species for tank waste

    SciTech Connect

    Visnapuu, A.; Hollenberg, G.W.; Creed, R.F. Jr.

    1994-05-01

    Much of the waste generated from five decades of weapons production in the US Department of Energy complex contains highly radioactive constituents. With the high cost of permanent disposal space, it is necessary to separate as many of the nonradioactive species from the radioactive as possible. This paper discusses the transfer of carbonyl processing technology from mineral beneficiation and powder metallurgy operations to the separation of Fe and Ni from radioactively contaminated waste streams. Samples of simulated composite Hanford Tank Waste residue were first processed with a calcine/dissolution technique which resulted in a residue powder consisting of 31.9 pct Fe and 3.3 pct Ni. Because of the specification for waste glass compositions, these two constituents become important in determining the number of waste glass logs produced. Pyrometallurgical reduction of the residue powders, followed by subsequent carbonylation, extracted up to 92.0 pct of the Fe and 95.7 pct of the Ni. The resultant product contained as little as 4.9 pct Fe and 0.3 pct Ni. At this level, Fe would no longer be a limiting constituent in the waste glass.