WorldWideScience

Sample records for aldehyde-lyases

  1. A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes: DISCOVERY OF P450-TYPE HYDROPEROXIDE LYASE ACTIVITY IN A CATALASE.

    Science.gov (United States)

    Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E; Calcutt, Wade M; Brash, Alan R; Samel, Nigulas

    2015-08-07

    In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using (18)O-labeled substrate and incubations in H2(18)O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Alfalfa contains substantial 9-hydroperoxide lyase activity and a 3Z:2E-enal isomerase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    1999-01-01

    Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short-chain aldehydes and omega-oxo acids. Plant hydroperoxide lyases use 13- or 9-hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been

  3. The hydroxynitrile lyase from almond: crystal structure and mechanistical studies

    International Nuclear Information System (INIS)

    Dreveny, Ingrid

    2001-09-01

    Cyanogenesis is a defense process of several thousand plant species. Hydroxynitrile lyase (HNL), a key enzyme of this process, cleaves a cyanohydrin precursor into hydrocyanic acid and the corresponding aldehyde or ketone. The reverse reaction constitutes an important tool in industrial biocatalysis. Different classes of hydroxynitrile lyases have convergently evolved from FAD-dependent oxidoreductases, α/β hydrolases and alcohol dehydrogenases. The FAD-dependent hydroxynitrile lyases (FAD-HNLs) carry a flavin cofactor whose redox properties appear to be unimportant for catalysis. The high resolution crystal structure of the hydroxynitrile lyase from almond (Prunus amygdalus), PaHNL1, has been determined and constitutes the first 3D structure of an FAD-HNL. The overall fold and the architecture of the active site region showed that PaHNL1 belongs to the glucose-methanol-choline-oxidoreductase family, with closest structural similarity to glucose oxidase. There is strong evidence from the sequence and the reaction product that FAD-dependent hydroxynitrile lyases have evolved from an aryl alcohol oxidizing precursor. Structures of PaHNL1 in complex with its natural substrate mandelonitrile and the competitive inhibitor benzyl alcohol provided insight into the residues involved in catalysis and a mechanism without participation of the cofactor could be suggested. Although the catalytic residues differ between the α/β-hydrolase-type HNLs and PaHNL1, common general features relevant for hydroxynitrile lyase activity could be proposed. (author)

  4. Epigenetic regulation of pro-inflammatory cytokine secretion by sphingosine 1-phosphate (S1P) in acute lung injury: Role of S1P lyase.

    Science.gov (United States)

    Ebenezer, David L; Fu, Panfeng; Suryadevara, Vidyani; Zhao, Yutong; Natarajan, Viswanathan

    2017-01-01

    Cellular level of sphingosine-1-phosphate (S1P), the simplest bioactive sphingolipid, is tightly regulated by its synthesis catalyzed by sphingosine kinases (SphKs) 1 & 2 and degradation mediated by S1P phosphatases, lipid phosphate phosphatases, and S1P lyase. The pleotropic actions of S1P are attributed to its unique inside-out (extracellular) signaling via G-protein-coupled S1P1-5 receptors, and intracellular receptor independent signaling. Additionally, S1P generated in the nucleus by nuclear SphK2 modulates HDAC1/2 activity, regulates histone acetylation, and transcription of pro-inflammatory genes. Here, we present data on the role of S1P lyase mediated S1P signaling in regulating LPS-induced inflammation in lung endothelium. Blocking S1P lyase expression or activity attenuated LPS-induced histone acetylation and secretion of pro-inflammatory cytokines. Degradation of S1P by S1P lyase generates Δ2-hexadecenal and ethanolamine phosphate and the long-chain fatty aldehyde produced in the cytoplasmic compartment of the endothelial cell seems to modulate histone acetylation pattern, which is different from the nuclear SphK2/S1P signaling and inhibition of HDAC1/2. These in vitro studies suggest that S1P derived long-chain fatty aldehyde may be an epigenetic regulator of pro-inflammatory genes in sepsis-induced lung inflammation. Trapping fatty aldehydes and other short chain aldehydes such as 4-hydroxynonenal derived from S1P degradation and lipid peroxidation, respectively by cell permeable agents such as phloretin or other aldehyde trapping agents may be useful in treating sepsis-induced lung inflammation via modulation of histone acetylation. . Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. C12 derivatives of the hydroperoxide lyase pathway are produced by product recycling through lipoxygenase-2 in Nicotiana attenuata leaves

    NARCIS (Netherlands)

    Kallenbach, M.; Gilardoni, P.A.; Allmann, S.; Baldwin, I.T.; Bonaventure, G.

    2011-01-01

    In response to diverse stresses, the hydroperoxide lyase (HPL) pathway produces C(6) aldehydes and 12-oxo-(9Z )-dodecenoic acid ((9Z )-traumatin). Since the original characterization of (10E )-traumatin and traumatic acid, little has been added to our knowledge of the metabolism and fluxes

  6. A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes

    Science.gov (United States)

    Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E.; Calcutt, Wade M.; Brash, Alan R.; Samel, Nigulas

    2015-01-01

    In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using 18O-labeled substrate and incubations in H218O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. PMID:26100625

  7. Sphingosine 1-phosphate lyase enzyme assay using a BODIPY-labeled substrate

    International Nuclear Information System (INIS)

    Bandhuvula, Padmavathi; Li Zaiguo; Bittman, Robert; Saba, Julie D.

    2009-01-01

    Sphingosine 1-phosphate lyase (SPL) is responsible for the irreversible catabolism of sphingosine 1-phosphate, which signals through five membrane receptors to mediate cell stress responses, angiogenesis, and lymphocyte trafficking. The standard assay for SPL activity utilizes a radioactive dihydrosphingosine 1-phosphate substrate and is expensive and cumbersome. In this study, we describe an SPL assay that employs an ω-labeled BODIPY-sphingosine 1-phosphate substrate, allowing fluorescent product detection by HPLC and incorporating advantages of the BODIPY fluorophore. The major aldehyde product is confirmed by reaction with 2,4-dinitrophenylhydrazine. The SPL-catalyzed reaction is linear over a 30 min time period and yields a K m of 35 μM for BODIPY-sphingosine 1-phosphate.

  8. Enantioselective Synthesis of Various Cyanohydrins Using Covalently Immobilized Preparations of Hydroxynitrile Lyase from Prunus dulcis.

    Science.gov (United States)

    Alagöz, Dilek; Tükel, S Seyhan; Yildirim, Deniz

    2015-11-01

    The carrier-based and carrier-free (cross-linked enzyme aggregate) covalent immobilizations of Prunus dulcis hydroxynitrile lyase were investigated. The immobilized preparations were tested for enantioselective carbon-carbon bond formation activity in the biphasic medium. Of the tested preparations, only cross-linked enzyme aggregate of P. dulcis hydroxynitrile lyase (PdHNL-CLEA) achieved the synthesis of (R)-mandelonitrile with 93% yield and 99% enantiopurity. PdHNL-CLEA was also used in the synthesis of various (R)-cyanohydrins from corresponding aldehydes/ketones and hydrocyanic acid. When 4-methoxybenzaldehyde, 4-methyl benzaldehyde, and 4-hydroxybenzaldehyde were used as substrates, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were obtained as 95-95, 85-79, and 2-25%, respectively, after 96 h at pH 4.0 and 5 °C. For acetophenone, 4-fluoroacetophenone, 4-chloroacetophenone, 4-bromoacetophenone, and 4-iodoacetophenone, the yield-enantiomeric excess of corresponding (R)-cyanohydrins were 1-99, 20-84, 11-95, 5-99, and 3-24%, respectively at the same conditions. The results demonstrate PdHNL-CLEA can be effectively used in the synthesis of (R)-mandelonitrile.

  9. Distinct roles of jasmonates and aldehydes in plant-defense responses.

    Directory of Open Access Journals (Sweden)

    E Wassim Chehab

    Full Text Available BACKGROUND: Many inducible plant-defense responses are activated by jasmonates (JAs, C(6-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS and hydroperoxide lyase (HPL branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C(6-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C(6-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae, an insect herbivore (leafminers: Liriomyza trifolii, and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola. We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani, a natural enemy of aphids. PRINCIPAL FINDINGS: This study conclusively establishes that jasmonates and C(6-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C(6-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C(6-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic

  10. Impact of different alginate lyases on combined cellulase–lyase saccharification of brown seaweed

    DEFF Research Database (Denmark)

    Manns, Dirk Martin; Nyffenegger, Christian; Saake, B.

    2016-01-01

    -guluronic acid. When applied together with a fungal cellulase preparation (Cellic®CTec2) at pH 6 and 40 °C on a glucan rich brown seaweed Laminaria digitata the viscosity decreased in the initial minutes while measurable alginate degradation occurred primarily within the first 1–2 hours of reaction. Whereas FALy......, indicating that the degradation of mannuronic acid blocks inhibited cellulase catalyzed glucose release from L. digitata. Nevertheless, combined alginate lyase and cellulase treatment for 24 hours released all potential glucose regardless of the applied lyase. The enzymatic treatment moreover induced...

  11. Enhancing RGI lyase thermostability by targeted single point mutations

    DEFF Research Database (Denmark)

    Silva, Inês R.; Larsen, Dorte Møller; Jers, Carsten

    2013-01-01

    Rhamnogalacturonan I lyase (RGI lyase) (EC 4.2.2.-) catalyzes the cleavage of rhamnogalacturonan I in pectins by β-elimination. In this study the thermal stability of a RGI lyase (PL 11) originating from Bacillus licheniformis DSM 13/ATCC14580 was increased by a targeted protein engineering...

  12. Molecular characterization of a Penicillium chrysogenum exo-rhamnogalacturonan lyase that is structurally distinct from other polysaccharide lyase family proteins.

    Science.gov (United States)

    Iwai, Marin; Kawakami, Takuya; Ikemoto, Takeshi; Fujiwara, Daisuke; Takenaka, Shigeo; Nakazawa, Masami; Ueda, Mitsuhiro; Sakamoto, Tatsuji

    2015-10-01

    We previously described an endo-acting rhamnogalacturonan (RG) lyase, termed PcRGL4A, of Penicillium chrysogenum 31B. Here, we describe a second RG lyase, called PcRGLX. We determined the cDNA sequence of the Pcrglx gene, which encodes PcRGLX. Based on analyses using a BLAST search and a conserved domain search, PcRGLX was found to be structurally distinct from known RG lyases and might belong to a new polysaccharide lyase family together with uncharacterized fungal proteins of Nectria haematococca, Aspergillus oryzae, and Fusarium oxysporum. The Pcrglx cDNA gene product (rPcRGLX) expressed in Escherichia coli demonstrated specific activity against RG but not against homogalacturonan. Divalent cations were not essential for the enzymatic activity of rPcRGLX. rPcRGLX mainly released unsaturated galacturonosyl rhamnose (ΔGR) from RG backbones used as the substrate from the initial stage of the reaction, indicating that the enzyme can be classified as an exo-acting RG lyase (EC 4.2.2.24). This is the first report of an RG lyase with this mode of action in Eukaryota. rPcRGLX acted synergistically with PcRGL4A to degrade soybean RG and released ΔGR. This ΔGR was partially decorated with galactose (Gal) residues, indicating that rPcRGLX preferred oligomeric RGs to polymeric RGs, that the enzyme did not require Gal decoration of RG backbones for degradation, and that the enzyme bypassed the Gal side chains of RG backbones. These characteristics of rPcRGLX might be useful in the determination of complex structures of pectins.

  13. In Silico Characterization of Pectate Lyase Protein Sequences from Different Source Organisms

    Directory of Open Access Journals (Sweden)

    Amit Kumar Dubey

    2010-01-01

    Full Text Available A total of 121 protein sequences of pectate lyases were subjected to homology search, multiple sequence alignment, phylogenetic tree construction, and motif analysis. The phylogenetic tree constructed revealed different clusters based on different source organisms representing bacterial, fungal, plant, and nematode pectate lyases. The multiple accessions of bacterial, fungal, nematode, and plant pectate lyase protein sequences were placed closely revealing a sequence level similarity. The multiple sequence alignment of these pectate lyase protein sequences from different source organisms showed conserved regions at different stretches with maximum homology from amino acid residues 439–467, 715–816, and 829–910 which could be used for designing degenerate primers or probes specific for pectate lyases. The motif analysis revealed a conserved Pec_Lyase_C domain uniformly observed in all pectate lyases irrespective of variable sources suggesting its possible role in structural and enzymatic functions.

  14. Crystallization and preliminary X-ray analysis of an exotype alginate lyase Atu3025 from Agrobacterium tumefaciens strain C58, a member of polysaccharide lyase family 15

    International Nuclear Information System (INIS)

    Ochiai, Akihito; Yamasaki, Masayuki; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2006-01-01

    The crystallization and preliminary X-ray characterization of a family PL-15 exotype alginate lyase are presented. Almost all alginate lyases depolymerize alginate in an endolytical fashion via a β-elimination reaction. The alginate lyase Atu3025 from Agrobacterium tumefaciens strain C58, consisting of 776 amino-acid residues, is a novel exotype alginate lyase classified into polysaccharide lyase family 15. The enzyme was crystallized at 293 K by sitting-drop vapour diffusion with polyethylene glycol 4000 as a precipitant. Preliminary X-ray analysis showed that the Atu3025 crystal belonged to space group P2 1 and diffracted to 2.8 Å resolution, with unit-cell parameters a = 107.7, b = 108.3, c = 149.5 Å, β = 91.5°

  15. Cloning and expression of isocitrate lyase from human round worm Strongyloides stercoralis

    Directory of Open Access Journals (Sweden)

    Siddiqui A.A.

    2000-09-01

    Full Text Available A full length cDNA (1463 bp encoding isocitrate lyase (EC 4.1.3.1 of Strongyloides stercoralis is described. The nucleotide sequence of this insert identified a cDNA coding for the isocitrate lyase. The conceptually translated amino acid sequence of the open reading frame for S. stercoralis isocitrate lyase encodes a 450 amino acid residue protein with an apparent molecular weight of 50 kDa and a predicted pl of 6.39. The sequence is 69 % A/T, reflecting a characteristic A/T codon bias of S. stercoralis. The amino acid sequence of S. stercoralis isocitrate lyase is compared with bifunctional glyoxylate cycle protein of Caenorhabditis elegans and isocitrate lyases from Chlamydomonas reinhardtii and Myxococcus xanthus. The full length cDNA of S. stercoralis was expressed in pRSET vector and bacteriophage T7 promoter based expression system. S. stercoralis lyase recombinant protein, purified via immobilized metal affinity chromatography, showed a molecular mass of 50 kDa on polyacrylamide gels. The role of isocitrate lyase in the glyoxylate cycle and energy metabolism of S. stercoralis is also discussed.

  16. Studies on pectin lyase

    NARCIS (Netherlands)

    Houdenhoven, van F.E.A.

    1975-01-01

    The pectin lyase activity in the commercial enzyme preparation Ultrazym originates from more then one type of enzyme; two of them, accounting for 95 % of the total activity, have been completely purified. As purity criteria specific activity, polyacrylamide disc gel electrophoresis and SDS

  17. Development of a biocatalytic process for the production of c6-aldehydes from vegetable oils by soybean lipoxygenase and recombinant hydroperoxide lyase

    NARCIS (Netherlands)

    Noordermeer, M.A.; Goot, van der W.; Kooij, van A.J.; Veldsink, J.W.; Veldink, G.A.; Vliegenthart, J.F.G.

    2002-01-01

    Volatile C6- and C9-aldehydes and alcohols are widely used as food flavors to reconstitute the "fresh green" odor of fruits and vegetables lost during processing. To meet the high demand for natural flavors, an efficient, cheap, and versatile biocatalytic process was developed to produce

  18. Circadian Rhythmicity in the Activities of Phenylalanine Ammonia-Lyase from Lemna perpusilla and Spirodela polyrhiza 1

    Science.gov (United States)

    Gordon, William R.; Koukkari, Willard L.

    1978-01-01

    The oscillations in phenylalanine ammonia-lyase activity from Spirodela polyrhiza and phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities from Lemna perpusilla displayed a circadian rhythm under continuous light. Rhythmicity in enzymic activity could not be detected in continuous darkness since under this condition phenylalanine ammonia-lyase activity remains at a fairly constantly low level. Results from our studies of the oscillatory pattern of the respective activities of phenylalanine and tyrosine ammonia-lyase support their “inseparability.” PMID:16660569

  19. First general methods toward aldehyde enolphosphates.

    Science.gov (United States)

    Barthes, Nicolas; Grison, Claude

    2012-02-01

    We herein report two innovative methods toward aldehyde enolphosphates and the first saccharidic aldehyde enolphosphates. Aldehyde enolphosphate function is worthwhile to be considered as a good phosphoenolpyruvate analogue. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Utilization of Aspergillus oryzae to produce pectin lyase from various agro-industrial residues

    Directory of Open Access Journals (Sweden)

    Safia Koser

    2014-07-01

    Full Text Available The present study was aimed to investigate the culture influence on pectin lyase production potential of fungal strain Aspergillus oryzae. The enzyme profile of A. oryzae showed highest activity of pectin lyase after 3rd day of incubation on lemon peel waste under solid state fermentation conditions. To induce the pectin lyase synthesis capability of A. oryzae at optimal level various culture variables including physical and nutritional parameters were optimized by adopting classical optimization technique. Therefore, through fermentation process optimization the production of pectin lyase was substantially induced up to the level of 875 U/mL, when fermentation medium of lemon peel waste inoculated with 5 mL spore suspension of A. oryzae. The optimal fermentation conditions for maximum pectin lyase yield were as: optimum pH 5, 70% moisture level and incubated at 40 °C in addition with 1% sterile glucose solution as readily available carbon source and 0.2% yeast extract as an inexpensive nitrogen supplement (1%. The results obtained in current investigation so far demonstrated that culture conditions have great influence on the pectin lyase production potential of A. oryzae.

  1. Characterization of AlgMsp, an alginate lyase from Microbulbifer sp. 6532A.

    Directory of Open Access Journals (Sweden)

    Steven M Swift

    Full Text Available Alginate is a polysaccharide produced by certain seaweeds and bacteria that consists of mannuronic acid and guluronic acid residues. Seaweed alginate is used in food and industrial chemical processes, while the biosynthesis of bacterial alginate is associated with pathogenic Pseudomonas aeruginosa. Alginate lyases cleave this polysaccharide into short oligo-uronates and thus have the potential to be utilized for both industrial and medicinal applications. An alginate lyase gene, algMsp, from Microbulbifer sp. 6532A, was synthesized as an E.coli codon-optimized clone. The resulting 37 kDa recombinant protein, AlgMsp, was expressed, purified and characterized. The alginate lyase displayed highest activity at pH 8 and 0.2 M NaCl. Activity of the alginate lyase was greatest at 50°C; however the enzyme was not stable over time when incubated at 50°C. The alginate lyase was still highly active at 25°C and displayed little or no loss of activity after 24 hours at 25°C. The activity of AlgMsp was not dependent on the presence of divalent cations. Comparing activity of the lyase against polymannuronic acid and polyguluronic acid substrates showed a higher turnover rate for polymannuronic acid. However, AlgMSP exhibited greater catalytic efficiency with the polyguluronic acid substrate. Prolonged AlgMsp-mediated degradation of alginate produced dimer, trimer, tetramer, and pentamer oligo-uronates.

  2. Alcohol, Aldehydes, Adducts and Airways

    Directory of Open Access Journals (Sweden)

    Muna Sapkota

    2015-11-01

    Full Text Available Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA adduct and hybrid malondialdehyde-acetaldehyde (MAA protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

  3. Structure and Mechanism of PhnP, a Phosphodiesterase of the Carbon-Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    He, Shu-Mei; Wathier, Matthew; Podzelinska, Kateryna

    2011-01-01

    PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo-β-lactamase s......PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo...

  4. Prenatal diagnosis in adenylosuccinate lyase deficiency

    NARCIS (Netherlands)

    Marie, S.; Flipsen, J. W.; Duran, M.; Poll-The, B. T.; Beemer, F. A.; Bosschaart, A. N.; Vincent, M. F.; van den Berghe, G.

    2000-01-01

    Adenylosuccinate lyase deficiency, an autosomal recessive inborn error of purine synthesis, provokes accumulation in body fluids of succinylaminoimidazolecarboxamide riboside and succinyladenosine, the dephosphorylated derivatives of the two substrates of the enzyme. Most patients display severe

  5. Production and Purification of a Novel Xanthan Lyase from a Xanthan-Degrading Microbacterium sp. Strain XT11

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2014-01-01

    Full Text Available A xanthan lyase was produced and purified from the culture supernatant of an excellent xanthan-modifying strain Microbacterium sp. XT11. Xanthan lyase was induced by xanthan but was inhibited by its structural monomer glucose. Its production by strain XT11 is much higher than that by all other reported strains. The purified xanthan lyase has a molecular mass of 110 kDa and a specific activity of 28.2 U/mg that was much higher than that of both Paenibacillus and Bacillus lyases. It was specific on the pyruvated mannosyl residue in the intact xanthan molecule, but about 50% lyase activity remained when xanthan was partially depyruvated. Xanthan lyase was optimally active at pH 6.0–6.5 and 40°C and alkali-tolerant at a high pH value of 11.0. The metal ions including K+, Ca2+, Na+, Mg2+, Mn2+, and Li+ strongly stimulated xanthan lyase activity but ions Zn2+ and Cu2+ were its inhibitor. Xanthan lyase should be a novel enzyme different from the other xanthan lyases ever reported.

  6. Utilization of Aspergillus oryzae to produce pectin lyase from various agro-industrial residues

    OpenAIRE

    Koser, Safia; Anwar, Zahid; Iqbal, Zafar; Anjum, Awais; Aqil, Tahir; Mehmood, Sajid; Irshad, Muhammad

    2014-01-01

    The present study was aimed to investigate the culture influence on pectin lyase production potential of fungal strain Aspergillus oryzae. The enzyme profile of A. oryzae showed highest activity of pectin lyase after 3rd day of incubation on lemon peel waste under solid state fermentation conditions. To induce the pectin lyase synthesis capability of A. oryzae at optimal level various culture variables including physical and nutritional parameters were optimized by adopting classical optimiza...

  7. A novel gene encoding xanthan lyase of Paenibacillus alginolyticus strain XL-1

    NARCIS (Netherlands)

    Ruijssenaars, H.J.; Hartmans, S.; Verdoes, J.C.

    2000-01-01

    Xanthan-modifying enzymes are powerful tools in studying structure-function relationships of this polysaccharide. One of these modifying enzymes is xanthan lyase, which removes the terminal side chain residue of xanthan. In this paper, the cloning and sequencing of the first xanthan lyase-encoding

  8. Crystallization and preliminary X-ray analysis of βC–S lyases from two oral streptococci

    International Nuclear Information System (INIS)

    Kezuka, Yuichiro; Yoshida, Yasuo; Nonaka, Takamasa

    2009-01-01

    The βC-S lyases from two oral bacteria, Streptococcus anginosus and S. gordonii, were cloned, overproduced, purified and crystallized. The obtained crystals were characterized by X-ray diffraction. Hydrogen sulfide, which causes oral malodour, is generally produced from l-cysteine by the action of βC–S lyase from oral bacteria. The βC–S lyases from two oral bacteria, Streptococcus anginosus and S. gordonii, have been cloned, overproduced, purified and crystallized. X-ray diffraction data were collected from the two types of crystals using synchrotron radiation. The crystal of S. anginosus βC–S lyase belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 67.0, b = 111.1, c = 216.4 Å, and the crystal of S. gordonii βC–S lyase belonged to the same space group, with unit-cell parameters a = 58.0, b = 73.9. c = 187.6 Å. The structures of the βC–S lyases were solved by molecular-replacement techniques

  9. Cytochrome c and c1 heme lyases are essential in Plasmodium berghei.

    Science.gov (United States)

    Posayapisit, Navaporn; Songsungthong, Warangkhana; Koonyosying, Pongpisid; Falade, Mofolusho O; Uthaipibull, Chairat; Yuthavong, Yongyuth; Shaw, Philip J; Kamchonwongpaisan, Sumalee

    Malaria parasites possess a de novo heme synthetic pathway. Interestingly, this pathway is dispensable during the blood stages of development in mammalian hosts. The assembly of the two most important hemeproteins, cytochromes c and c1, is mediated by cytochrome heme lyase enzymes. Plasmodium spp. possess two cytochrome heme lyases encoded by separate genes. Given the redundancy of heme synthesis, we sought to determine if heme lyase function also exhibits redundancy. To answer this question, we performed gene knockout experiments. We found that the PBANKA_143950 and PBANKA_0602600 Plasmodium berghei genes encoding cytochrome c (Pbcchl) and cytochrome c1 (Pbcc 1 hl) heme lyases, respectively, can only be disrupted when a complementary gene is present. In contrast, four genes in the de novo heme synthesis pathway can be disrupted without complementation. This work provides evidence that Pbcchl and Pbcc 1 hl are both essential and thus may be antimalarial targets. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Myoglobin-Catalyzed Olefination of Aldehydes.

    Science.gov (United States)

    Tyagi, Vikas; Fasan, Rudi

    2016-02-12

    The olefination of aldehydes constitutes a most valuable and widely adopted strategy for constructing carbon-carbon double bonds in organic chemistry. While various synthetic methods have been made available for this purpose, no biocatalysts are known to mediate this transformation. Reported herein is that engineered myoglobin variants can catalyze the olefination of aldehydes in the presence of α-diazoesters with high catalytic efficiency (up to 4,900 turnovers) and excellent E diastereoselectivity (92-99.9 % de). This transformation could be applied to the olefination of a variety of substituted benzaldehydes and heteroaromatic aldehydes, also in combination with different alkyl α-diazoacetate reagents. This work provides a first example of biocatalytic aldehyde olefination and extends the spectrum of synthetically valuable chemical transformations accessible using metalloprotein-based catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities and lignin synthesis in wheat grown under low pressure sodium lamps

    Science.gov (United States)

    Guerra, D.; Anderson, A. J.; Salisbury, F. B.

    1985-01-01

    Wheat (Triticum aestivum L. cv Fremont) grown in hydroponic culture under 24-hour continuous irradiation at 560 to 580 micromoles per square meter per second from either metalhalide (MH), high pressure sodium (HPS), or low pressure sodium (LPS) lamps reached maturity in 70 days. Grain yields were similar under all three lamps, although LPS-grown plants lodged at maturity. Phenylalanine ammonia-lyase (PAL) and a tyrosine ammonia lyase (TAL) with lesser activity were detected in all extracts of leaf, inflorescence, and stem. Ammonia-lyase activities increased with age of the plant, and plants grown under the LPS lamp displayed PAL and TAL activities lower than wheat cultured under MH and HPS radiation. Greenhouse solar-grown wheat had the highest PAL and TAL activities. Lignin content of LPS-grown wheat was also significantly reduced from that of plants grown under MH or HPS lamps or in the greenhouse, showing a correlation with the reduced PAL and TAL activities. Ratios of far red-absorbing phytochrome to total phytochrome were similar for all three lamps, but the data do not yet warrant a conclusion about specific wavelengths missing from the LPS lamps that might have induced PAL and TAL activities in plants under the other lamps.

  12. Identification of aldehyde oxidase 1 and aldehyde oxidase homologue 1 as dioxin-inducible genes

    International Nuclear Information System (INIS)

    Rivera, Steven P.; Choi, Hyun Ho; Chapman, Brett; Whitekus, Michael J.; Terao, Mineko; Garattini, Enrico; Hankinson, Oliver

    2005-01-01

    Aldehyde oxidases are a family of highly related molybdo-flavoenzymes acting upon a variety of compounds of industrial and medical importance. We have identified aldehyde oxidase 1 (AOX1) as a 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) inducible gene in the mouse hepatoma cell line Hepa-1. AOX1 mRNA levels were not increased by dioxin in mutant derivatives of the Hepa-1 cell line lacking either functional aryl hydrocarbon receptor (AHR) or aryl hydrocarbon receptor nuclear translocator (ARNT) proteins, thus demonstrating that transcriptional induction of AOX1 in response to dioxin occurs through the AHR pathway. Dioxin induction of AOX1 mRNA was also observed in mouse liver. In addition, levels of AOX1 protein as well as those of aldehyde oxidase homologue 1 (AOH1), a recently identified homolog of AOX1, were elevated in mouse liver in response to dioxin. Employing an aldehyde oxidase specific substrate, AOX1/AOH1 activity was shown to be induced by dioxin in mouse liver. This activity was inhibited by a known inhibitor of aldehyde oxidases, and eliminated by including tungstate in the mouse diet, which is known to lead to inactivation of molybdoflavoenzymes, thus confirming that the enzymatic activity was attributable to AOX1/AOH1. Our observations thus identify two additional xenobiotic metabolizing enzymes induced by dioxin

  13. A QM/MM study of the reaction mechanism of (R)-hydroxynitrile lyases from Arabidopsis thaliana (AtHNL).

    Science.gov (United States)

    Zhu, Wenyou; Liu, Yongjun; Zhang, Rui

    2015-01-01

    Hydroxynitrile lyases (HNLs) catalyze the conversion of chiral cyanohydrins to hydrocyanic acid (HCN) and aldehyde or ketone. Hydroxynitrile lyase from Arabidopsis thaliana (AtHNL) is the first R-selective HNL enzyme containing an α/β-hydrolases fold. In this article, the catalytic mechanism of AtHNL was theoretically studied by using QM/MM approach based on the recently obtained crystal structure in 2012. Two computational models were constructed, and two possible reaction pathways were considered. In Path A, the calculation results indicate that the proton transfer from the hydroxyl group of cyanohydrin occurs firstly, and then the cleavage of C1-C2 bond and the rotation of the generated cyanide ion (CN(-)) follow, afterwards, CN(-) abstracts a proton from His236 via Ser81. The C1-C2 bond cleavage and the protonation of CN(-) correspond to comparable free energy barriers (12.1 vs. 12.2 kcal mol(-1)), suggesting that both of the two processes contribute a lot to rate-limiting. In Path B, the deprotonation of the hydroxyl group of cyanohydrin and the cleavage of C1-C2 bond take place in a concerted manner, which corresponds to the highest free energy barrier of 13.2 kcal mol(-1). The free energy barriers of Path A and B are very similar and basically agree well with the experimental value of HbHNL, a similar enzyme of AtHNL. Therefore, both of the two pathways are possible. In the reaction, the catalytic triad (His236, Ser81, and Asp208) acts as the general acid/base, and the generated CN(-) is stabilized by the hydroxyl group of Ser81 and the main-chain NH-groups of Ala13 and Phe82. © 2014 Wiley Periodicals, Inc.

  14. Deodorants: An experimental provocation study with cinnamic aldehyde

    DEFF Research Database (Denmark)

    Bruze, M.; Johansen, J. D.; Andersen, K. E.

    2003-01-01

    BACKGROUND: Axillary dermatitis is common and overrepresented in individuals with contact allergy to fragrances. Many individuals suspect their deodorants to be the incriminating products. OBJECTIVE: Our aim was to investigate the significance of cinnamic aldehyde in deodorants for the development...... of axillary dermatitis when used by individuals with and without contact allergy to cinnamic aldehyde. METHODS: Patch tests with deodorants and ethanol solutions with cinnamic aldehyde, and repeated open application tests with roll-on deodorants without and with cinnamic aldehyde at different concentrations......, were performed in 37 patients with dermatitis, 20 without and 17 with contact allergy to cinnamic aldehyde. RESULTS: A repeated open application test with positive findings was noted only in patients hypersensitive to cinnamic aldehyde (P deodorants containing...

  15. Chondroitin Sulfate (CS) Lyases: Structure, Function and Application in Therapeutics.

    Science.gov (United States)

    Rani, Aruna; Patel, Seema; Goyal, Arun

    2018-01-01

    Glycosaminoglycans (GAGs) such as chondroitin sulfate (CS) are the chief natural polysaccharides which reside in biological tissues mainly in extracellular matrix. These CS along with adhesion molecules and growth factors are involved in central nervous system (CNS) development, cell progression and pathogenesis. The chondroitin lyases are the enzyme that degrade and alter the CS chains and hence modify various signalling pathways involving CS chains. These CS lyases are substrate specific, can precisely manipulate the CS polysaccharides and have various biotechnological, medical and therapeutic applications. These enzymes can be used to produce the unsaturated oligosaccharides, which have immune-modulatory, anti-inflammatory and neuroprotective properties. This review focuses on the major breakthrough of the chondroitin sulfate degrading enzymes, their structures and functioning mechanism. This also provides comprehensive information regarding production, purification, characterization of CS lyases and their major applications, both established as well as emerging ones such as neural development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Five Fatty Aldehyde Dehydrogenase Enzymes from Marinobacter and Acinetobacter spp. and Structural Insights into the Aldehyde Binding Pocket

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, Jonathan H.; Mulliner, Kalene M.; Shi, Ke; Plunkett, Mary H.; Nixon, Peter; Serratore, Nicholas A.; Douglas, Christopher J.; Aihara, Hideki; Barney, Brett M.; Parales, Rebecca E.

    2017-04-07

    ABSTRACT

    Enzymes involved in lipid biosynthesis and metabolism play an important role in energy conversion and storage and in the function of structural components such as cell membranes. The fatty aldehyde dehydrogenase (FAldDH) plays a central function in the metabolism of lipid intermediates, oxidizing fatty aldehydes to the corresponding fatty acid and competing with pathways that would further reduce the fatty aldehydes to fatty alcohols or require the fatty aldehydes to produce alkanes. In this report, the genes for four putative FAldDH enzymes fromMarinobacter aquaeoleiVT8 and an additional enzyme fromAcinetobacter baylyiwere heterologously expressed inEscherichia coliand shown to display FAldDH activity. Five enzymes (Maqu_0438, Maqu_3316, Maqu_3410, Maqu_3572, and the enzyme reported under RefSeq accession no.WP_004927398) were found to act on aldehydes ranging from acetaldehyde to hexadecanal and also acted on the unsaturated long-chain palmitoleyl and oleyl aldehydes. A comparison of the specificities of these enzymes with various aldehydes is presented. Crystallization trials yielded diffraction-quality crystals of one particular FAldDH (Maqu_3316) fromM. aquaeoleiVT8. Crystals were independently treated with both the NAD+cofactor and the aldehyde substrate decanal, revealing specific details of the likely substrate binding pocket for this class of enzymes. A likely model for how catalysis by the enzyme is accomplished is also provided.

    IMPORTANCEThis study provides a comparison of multiple enzymes with the ability

  17. [Construction and high-density fermentation of alkaline pectate lyase high-yield yeast].

    Science.gov (United States)

    Wang, Xiaowen; Xiang, La; Xu, Ting; Lu, Zhenghui; Zhang, Guimin

    2017-12-25

    Pectate lyase is widely applied in ramie degumming and fabric bioscouring in the textile industry. Compared to conventional processes that involve high alkaline and high temperature treatment, enzyme based treatments have significant advantages in fibers protectiveness, improved efficiency of refining, reduced energy consumption and pollution. Hence, it would be highly desirable to construct high-yield alkaline pectate lyase engineered strains and reduce the pectate lyase production cost. In the previous study, pectate lyase gene pel from Bacillus subtilis168 was expressed in Pichia pastoris GS115 after codon usage optimization based on the vector pHBM905A. To improve the expression level, the vector pHBM905BDM with optimized promoter and signal peptide was used to express the optimized gene pels in GS115. The transformant had increased activity from 68 U/mL to 100 U/mL with the improvement in the transcription level by 27% measured by qPCR. The transformants were further screened on pectin plates, where higher halo forming strains were picked for shake-flask fermentation and strain GS115-pHBM905BDM-pels4 showed the highest activity of 536 U/mL. Then plasmid pPIC9K-pels was constructed and electroporated into the GS115-pHBM905BDM-pels4 cells. Subsequently, high-copy transformant was screened by using the medium containing antibiotics G418, strain GS115-pHBM905BDMpPIC9K- pels1 was identified with increased activity of 770 U/mL and the copy number of pels was 7 confirmed by qPCR. Finally, the activity of pectate lyase produced by GS115-pHBM905BDM-pPIC9K-pels1reached to 2 271 U/mL in a 5-L fermentor. The activity of pectate lyase in our study reached the highest level of expression in P. pastoris, showing good application potential in the textile industry.

  18. Characterization of a Novel Alginate Lyase from Marine Bacterium Vibrio furnissii H1

    Directory of Open Access Journals (Sweden)

    Xiaoyan Zhu

    2018-01-01

    Full Text Available Alginate lyases show great potential for industrial and medicinal applications, especially as an attractive biocatalyst for the production of oligosaccharides with special bioactivities. A novel alginate lyase, AlyH1, from the marine bacterium Vibrio furnissii H1, which has been newly isolated from rotten seaweed, was purified and characterized. The purified enzyme showed the specific activity of 2.40 U/mg. Its molecular mass was 35.8 kDa. The optimal temperature and pH were 40 °C and pH 7.5, respectively. AlyH1 maintained stability at neutral pH (7.0–8.0 and temperatures below 30 °C. Metal ions Na+, Mg2+, and K+ increased the activity of the enzyme. With sodium alginate as the substrate, the Km and Vmax values of AlyH1 were 2.28 mg/mL and 2.81 U/mg, respectively. AlyH1 exhibited activities towards both polyguluronate and polymannuronate, and preferentially degraded polyguluronate. Products prepared from sodium alginate by AlyH1 were displayed to be di-, tri-, and tetra-alginate oligosaccharides. A partial amino acid sequence (190 aa of AlyH1 analysis suggested that AlyH1 was an alginate lyase of polysaccharide lyase family 7. The sequence showed less than 77% identity to the reported alginate lyases. These data demonstrated that AlyH1 could be as a novel and potential candidate in application of alginate oligosaccharides production with low polymerization degrees.

  19. Quantitation of heparosan with heparin lyase III and spectrophotometry.

    Science.gov (United States)

    Huang, Haichan; Zhao, Yingying; Lv, Shencong; Zhong, Weihong; Zhang, Fuming; Linhardt, Robert J

    2014-02-15

    Heparosan is Escherichia coli K5 capsule polysaccharide, which is the key precursor for preparing bioengineered heparin. A rapid and effective quantitative method for detecting heparosan is important in the large-scale production of heparosan. Heparin lyase III (Hep III) effectively catalyzes the heparosan depolymerization, forming unsaturated disaccharides that are measurable using a spectrophotometer at 232 nm. We report a new method for the quantitative detection of heparosan with heparin lyase III and spectrophotometry that is safer and more specific than the traditional carbazole assay. In an optimized detection system, heparosan at a minimum concentration of 0.60 g/L in fermentation broth can be detected. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Xylella fastidiosa esterase rather than hydroxynitrile lyase.

    Science.gov (United States)

    Torrelo, Guzman; Ribeiro de Souza, Fayene Zeferino; Carrilho, Emanuel; Hanefeld, Ulf

    2015-03-02

    In 2009, we reported that the product of the gene SCJ21.16 (XFa0032) from Xylella fastidiosa, a xylem-restricted plant pathogen that causes a range of diseases in several important crops, encodes a protein (XfHNL) with putative hydroxynitrile lyase activity. Sequence analysis and activity tests indicated that XfHNL exhibits an α/β-hydrolase fold and could be classified as a member of the family of FAD-independent HNLs. Here we provide a more detailed sequence analysis and new experimental data. Using pure heterologously expressed XfHNL we show that this enzyme cannot catalyse the cleavage/synthesis of mandelonitrile and that this protein is in fact a non-enantioselective esterase. Homology modelling and ligand docking simulations were used to study the active site and support these results. This finding could help elucidate the common ancestor of esterases and hydroxynitrile lyases with an α/β -hydrolase fold. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Crosslinked enzyme aggregates of hydroxynitrile lyase partially purified from Prunus dulcis seeds and its application for the synthesis of enantiopure cyanohydrins.

    Science.gov (United States)

    Yildirim, Deniz; Tükel, S Seyhan; Alagöz, Dilek

    2014-01-01

    Hydroxynitrile lyases are powerful catalysts in the synthesis of enantiopure cyanohydrins which are key synthons in the preparations of a variety of important chemicals. The response surface methodology including three-factor and three-level Box-Behnken design was applied to optimize immobilization of hydroxynitrile lyase purified partially from Prunus dulcis seeds as crosslinked enzyme aggregates (PdHNL-CLEAs). The quadratic model was developed for predicting the response and its adequacy was validated with the analysis of variance test. The optimized immobilization parameters were initial glutaraldehyde concentration, ammonium sulfate saturation concentration, and crosslinking time, and the response was relative activity of PdHNL-CLEA. The optimal conditions were determined as initial glutaraldehyde concentration of 25% w/v, ammonium sulfate saturation concentration of 43% w/v, and crosslinking time of 18 h. The preparations of PdHNL-CLEA were examined for the synthesis of (R)-mandelonitrile, (R)-2-chloromandelonitrile, (R)-3,4-dihydroxymandelonitrile, (R)-2-hydroxy-4-phenyl butyronitrile, (R)-4-bromomandelonitrile, (R)-4-fluoromandelonitrile, and (R)-4-nitromandelonitrile from their corresponding aldehydes and hydrocyanic acid. After 96-h reaction time, the yield-enantiomeric excess values (%) were 100-99, 100-21, 100-99, 83-91, 100-99, 100-72, and 100-14%, respectively, for (R)-mandelonitrile, (R)-2-chloromandelonitrile, (R)-3,4-dihydroxymandelonitrile, (R)-2-hydroxy-4-phenyl butyronitrile, (R)-4-bromomandelonitrile, (R)-4-fluoromandelonitrile, and (R)-4-nitromandelonitrile. The results show that PdHNL-CLEA offers a promising potential for the preparation of enantiopure (R)-mandelonitrile, (R)-3,4-dihydroxymandelonitrile, (R)-2-hydroxy-4-phenyl butyronitrile, and (R)-4-bromomandelonitrile with a high yield and enantiopurity. © 2014 American Institute of Chemical Engineers.

  2. Catalytically important amino-acid residues of abalone alginate lyase HdAly assessed by site-directed mutagenesis

    OpenAIRE

    Yamamoto, Sayo; Sahara, Takehiko; Sato, Daisuke; Kawasaki, Kosei; Ohgiya, Satoru; Inoue, Akira; Ojima, Takao

    2008-01-01

    Alginate lyase is an enzyme that degrades alginate chains via β-elimination and has been used for the production of alginate oligosaccharides and protoplasts from brown algae. Previously, we deduced the amino-acid sequence of an abalone alginate lyase, HdAly, from its cDNA sequence and, through multiple amino-acid sequence alignment, found that several basic amino-acid residues were highly conserved among the polysaccharide-lyase family 14 (PL-14) enzymes including HdAly. In the present study...

  3. Process for producing furan from furfural aldehyde

    Science.gov (United States)

    Diebold, J.P.; Evans, R.J.

    1987-04-06

    A process of producing furan and derivatives thereof as disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  4. Process for producing furan from furfural aldehyde

    Science.gov (United States)

    Diebold, James P.; Evans, Robert J.

    1988-01-01

    A process of producing furan and derivatives thereof is disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

  5. Design of thermostable rhamnogalacturonan lyase mutants from Bacillus licheniformis by combination of targeted single point mutations

    DEFF Research Database (Denmark)

    da Silva, Ines Isabel Cardoso Rodrigues; Jers, Carsten; Otten, Harm

    2014-01-01

    Rhamnogalacturonan I lyases (RGI lyases) (EC 4.2.2.-) catalyze cleavage of α-1,4 bonds between rhamnose and galacturonic acid in the backbone of pectins by β-elimination. In the present study, targeted improvement of the thermostability of a PL family 11 RGI lyase from Bacillus licheniformis (DSM......, were obtained due to additive stabilizing effects of single amino acid mutations (E434L, G55V, and G326E) compared to the wild type. The crystal structure of the B. licheniformis wild-type RGI lyase was also determined; the structural analysis corroborated that especially mutation of charged amino...

  6. A radiometric technique for the measurement of adenylosuccinate lyase

    International Nuclear Information System (INIS)

    Park, K.W.; Tyagi, A.K.; Cooney, D.A.

    1980-01-01

    When radioactive adenylosuccinic acid (AMP-S) is metabolized to AMP and fumaric acid by the enzyme adenylosuccinate lyase (EC 4.3.2.2), a proton is released to the solvent as 3 H 2 O. This removal is believed to be stereospecifically identical to that catalyzed by the enzyme, L-aspartase, and therefore entails the loss of a proton from C-3 of the dicarboxylic acid moiety of the nucleotide. Advantage has been taken of this fact in the design of a facile assay for this enzyme. The assay permits the simultaneous estimation of the lyase activity in a large battery of samples; it is not interfered with by opalescent or proteinaceous suspensions; it is accurate and outstandingly sensitive. (Auth.)

  7. Cellular fatty acids and aldehydes of oral Eubacterium.

    Science.gov (United States)

    Itoh, U; Sato, M; Tsuchiya, H; Namikawa, I

    1995-02-01

    The cellular fatty acids and aldehydes of oral Eubacterium species were determined by gas chromatography-mass spectrometry. E. brachy and E. lentum contained mainly branched-chain fatty acids, whereas the others contained straight-chain acids. E. brachy, E. lentum, E. yurii ssp. yurii, E. yurii spp. margaretiae, E. limosum, E. plauti and E. aerofaciens also contained aldehydes with even carbon numbers. In addition to species-specific components, the compositional ratios of fatty acids and aldehydes characterized each individual species. The 10 species tested were divided into 5 groups by the principal component analysis. Cellular fatty acids and aldehydes would be chemical markers for interspecies differentiation of oral Eubacterium.

  8. Activities of methionine-γ-lyase in the acidophilic archaeon “Ferroplasma acidarmanus” strain fer1

    Directory of Open Access Journals (Sweden)

    Khan MA

    2013-04-01

    Full Text Available M A Khan,1 Madeline M López-Muñoz,2 Charles W Kaspar,3 Kai F Hung1 1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA; 2Department of Biology, Universidad de Puerto Rico, Mayaguez, Puerto Rico; 3Bacteriology Department, University of Wisconsin, Madison, WI, USA Abstract: Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1's ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine-γ-lyase (EC 4.4.1.11, an enzyme known to carry out α, γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5'-phosphate (PLP binding domain and a partially conserved catalytic domain in both putative sequences. Detection of PLP-dependent and L-methionine-dependent production of α-keto compounds and thiol groups in fer1 confirmed the presence of methionine-γ-lyase activity. Further, fer1 lysate was capable of processing related substrates, including D-methionine, L-cysteine, L-cystathionine, and L/D-homocysteine. When the two putative fer1 methionine-γ-lyase gene-coded proteins were expressed in Escherichia coli cells, one sequence demonstrated an ability to carry out α, γ-elimination activity, while the other exhibited γ-replacement activity. These fer1 methionine-γ-lyases also exhibited optimum pH, substrate specificity, and catalytic preferences that are different from methionine-γ-lyases from other organisms. These differences are discussed in the context of molecular phylogeny constructed using a maximum

  9. Hematopoietic Sphingosine 1-Phosphate Lyase Deficiency Decreases Atherosclerotic Lesion Development in LDL-Receptor Deficient Mice

    NARCIS (Netherlands)

    Bot, Martine; Van Veldhoven, Paul P.; de Jager, Saskia C. A.; Johnson, Jason; Nijstad, Niels; Van Santbrink, Peter J.; Westra, Marijke M.; Van Der Hoeven, Gerd; Gijbels, Marion J.; Mueller-Tidow, Carsten; Varga, Georg; Tietge, Uwe J. F.; Kuiper, Johan; Van Berkel, Theo J. C.; Nofer, Jerzy-Roch; Bot, Ilze; Biessen, Erik A. L.

    2013-01-01

    Aims: Altered sphingosine 1-phosphate (S1P) homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1(-/-)) deficiency on leukocyte subsets

  10. Hematopoietic sphingosine 1-phosphate lyase deficiency decreases atherosclerotic lesion development in LDL-receptor deficient mice

    NARCIS (Netherlands)

    Bot, Martine; van Veldhoven, Paul P.; de Jager, Saskia C. A.; Johnson, Jason; Nijstad, Niels; van Santbrink, Peter J.; Westra, Marijke M.; van der Hoeven, Gerd; Gijbels, Marion J.; Müller-Tidow, Carsten; Varga, Georg; Tietge, Uwe J. F.; Kuiper, Johan; van Berkel, Theo J. C.; Nofer, Jerzy-Roch; Bot, Ilze; Biessen, Erik A. L.

    2013-01-01

    Altered sphingosine 1-phosphate (S1P) homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1(-/-)) deficiency on leukocyte subsets relevant to

  11. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for the...

  12. Hematopoietic Sphingosine 1-Phosphate Lyase Deficiency Decreases Atherosclerotic Lesion Development in LDL-Receptor Deficient Mice

    NARCIS (Netherlands)

    Bot, M.; Veldhoven, van P.P.; Jager, de S.C.; Johnson, J.; Nijstad, N.; van, Santbrink P.J.; Westra, M.M.; Hoeven, van der G.; Gijbels, M.J.; Muller-Tidow, C.; Varga, G.; Tietge, U.J.; Kuiper, J.; Berkel, van T.J.; Nofer, J.R.; Bot, I.; Biessen, E.A.

    2013-01-01

    Abstract Aims Altered sphingosine 1-phosphate (S1P) homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1−/−) deficiency on leukocyte

  13. Molecular cloning, purification, and characterization of a novel polyMG-specific alginate lyase responsible for alginate MG block degradation in Stenotrophomas maltophilia KJ-2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su In; Kim, Hee Sook [Kyungsung Univ., Busan (Korea, Republic of). Dept. of Food Science and Biotechnology; Choi, Sung Hee; Lee, Eun Yeol [Kyung Hee Univ., Gyeonggi-do (Korea, Republic of). Dept. of Chemical Engineering

    2012-09-15

    A gene for a polyMG-specific alginate lyase possessing a novel structure was identified and cloned from Stenotrophomas maltophilia KJ-2 by using PCR with homologous nucleotide sequences-based primers. The recombinant alginate lyase consisting of 475 amino acids was purified on Ni-Sepharose column and exhibited the highest activity at pH 8 and 40 C. Interestingly, the recombinant alginate lyase was expected to have a similar catalytic active site of chondroitin B lyase but did not show chondroitin lyase activity. In the test of substrate specificity, the recombinant alginate lyase preferentially degraded the glycosidic bond of polyMG-block than polyM-block and polyG-block. The chemical structures of the degraded alginate oligosaccharides were elucidated to have mannuronate (M) at the reducing end on the basis of NMR analysis, supporting that KJ-2 polyMG-specific alginate lyase preferably degraded the glycosidic bond in M-G linkage than that in G-M linkage. The KJ-2 polyMG-specific alginate lyase can be used in combination with other alginate lyases for a synergistic saccharification of alginate. (orig.)

  14. Threshold responses in cinnamic-aldehyde-sensitive subjects

    DEFF Research Database (Denmark)

    Johansen, J D; Andersen, K E; Rastogi, Suresh Chandra

    1996-01-01

    Cinnamic aldehyde is an important fragrance material and contact allergen. The present study was performed to provide quantitative data on the eliciting capacity of cinnamic aldehyde, to be considered in assessment of clinical relevance and health hazard. The skin response to serial dilution patch...

  15. Sequence analysis and overexpression of a pectin lyase gene (pel1) from Aspergillus oryzae KBN616.

    Science.gov (United States)

    Kitamoto, N; Yoshino-Yasuda, S; Ohmiya, K; Tsukagoshi, N

    2001-01-01

    A gene (pel1) encoding pectin lyase (Pel1) was isolated from a shoyu koji mold, Aspergillus oryzae KBN616, and characterized. The structural gene comprised 1,196 bp with a single intron. The ORF encoded 381 amino acids with a signal peptide of 20 amino acids. The deduced amino acid sequence showed high similarity to those of Aspergillus niger pectin lyases and Glomerella cingulata PnlA. The pel1 gene was successfully overexpressed under the promoter of the A. oryzae TEF1 gene. The molecular mass of the recombinant pectin lyase substantially coincided with that calculated based on nucleotide sequence.

  16. Structure-based functional annotation of putative conserved proteins having lyase activity from Haemophilus influenzae.

    Science.gov (United States)

    Shahbaaz, Mohd; Ahmad, Faizan; Imtaiyaz Hassan, Md

    2015-06-01

    Haemophilus influenzae is a small pleomorphic Gram-negative bacteria which causes several chronic diseases, including bacteremia, meningitis, cellulitis, epiglottitis, septic arthritis, pneumonia, and empyema. Here we extensively analyzed the sequenced genome of H. influenzae strain Rd KW20 using protein family databases, protein structure prediction, pathways and genome context methods to assign a precise function to proteins whose functions are unknown. These proteins are termed as hypothetical proteins (HPs), for which no experimental information is available. Function prediction of these proteins would surely be supportive to precisely understand the biochemical pathways and mechanism of pathogenesis of Haemophilus influenzae. During the extensive analysis of H. influenzae genome, we found the presence of eight HPs showing lyase activity. Subsequently, we modeled and analyzed three-dimensional structure of all these HPs to determine their functions more precisely. We found these HPs possess cystathionine-β-synthase, cyclase, carboxymuconolactone decarboxylase, pseudouridine synthase A and C, D-tagatose-1,6-bisphosphate aldolase and aminodeoxychorismate lyase-like features, indicating their corresponding functions in the H. influenzae. Lyases are actively involved in the regulation of biosynthesis of various hormones, metabolic pathways, signal transduction, and DNA repair. Lyases are also considered as a key player for various biological processes. These enzymes are critically essential for the survival and pathogenesis of H. influenzae and, therefore, these enzymes may be considered as a potential target for structure-based rational drug design. Our structure-function relationship analysis will be useful to search and design potential lead molecules based on the structure of these lyases, for drug design and discovery.

  17. Cloning and study of the pectate lyase gene of Erwinia carotovora

    International Nuclear Information System (INIS)

    Bukanov, N.O.; Fonshtein, M.Yu.; Evtushenkov, A.N.; Syarinskii, M.A.; Strel'chenko, P.P.; Yankovski, N.K.; Alikhanyan, S.I.; Fomichev, Yu.K.; Debabov, V.G.

    1986-01-01

    The cloning of the gene of a secretable protein of Erwinia carotovora, pectate lyase, in Escherichia coli was described. Primary cloning was conducted using the phage vector λ 47.1. In the gene library of E. carotovora obtained, eight phages carrying the gene sought were identified according to the appearance of enzymatic activity of the gene product, pectate lyase, in situ. The BamHI fragment of DNA, common to all these phages, was recloned on the plasmid pUC19. It was shown that the cloned pectate lyase gene is represented on the E. carotovora chromosome in one copy. Methods of production of representative gene libraries on phage vectors from no less than 1 μg of cloned DNA even for the genomes of eukaryotes have now been developed. Vectors have been created, for example, λ 47.1, permitting the selection only of hybrid molecules. A number of methods have been developed for the search for a required gene in the library, depending on whether the cloned gene can be expressed or not, and if it can, what properties it will impart to the hybrid clone containing it

  18. Colorimetric Recognition of Aldehydes and Ketones.

    Science.gov (United States)

    Li, Zheng; Fang, Ming; LaGasse, Maria K; Askim, Jon R; Suslick, Kenneth S

    2017-08-07

    A colorimetric sensor array has been designed for the identification of and discrimination among aldehydes and ketones in vapor phase. Due to rapid chemical reactions between the solid-state sensor elements and gaseous analytes, distinct color difference patterns were produced and digitally imaged for chemometric analysis. The sensor array was developed from classical spot tests using aniline and phenylhydrazine dyes that enable molecular recognition of a wide variety of aliphatic or aromatic aldehydes and ketones, as demonstrated by hierarchical cluster, principal component, and support vector machine analyses. The aldehyde/ketone-specific sensors were further employed for differentiation among and identification of ten liquor samples (whiskies, brandy, vodka) and ethanol controls, showing its potential applications in the beverage industry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction

    DEFF Research Database (Denmark)

    Taarning, Esben; Madsen, Robert

    2008-01-01

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

  20. Ammonia lyases and aminomutases as biocatalysts for the synthesis of α-amino and β-amino acids.

    Science.gov (United States)

    Turner, Nicholas J

    2011-04-01

    Ammonia lyases catalyse the reversible addition of ammonia to cinnamic acid (1: R=H) and p-hydroxycinnamic (1: R=OH) to generate L-phenylalanine (2: R=H) and L-tyrosine (2: R=OH) respectively (Figure 1a). Both phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) are widely distributed in plants, fungi and prokaryotes. Recently there has been interest in the use of these enzymes for the synthesis of a broader range of L-arylalanines. Aminomutases catalyse a related reaction, namely the interconversion of α-amino acids to β-amino acids (Figure 1b). In the case of L-phenylalanine, this reaction is catalysed by phenylalanine aminomutase (PAM) and proceeds stereospecifically via the intermediate cinnamic acid to generate β-Phe 3. Ammonia lyases and aminomutases are related in sequence and structure and share the same active site cofactor 4-methylideneimidazole-5-one (MIO). There is currently interest in the possibility of using these biocatalysts to prepare a wide range of enantiomerically pure l-configured α-amino and β-amino acids. Recent reviews have focused on the mechanism of these MIO containing enzymes. The aim of this review is to review recent progress in the application of ammonia lyase and aminomutase enzymes to prepare enantiomerically pure α-amino and β-amino acids. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Kinetic and thermodynamic properties of alginate lyase and cellulase co-produced by Exiguobacterium species Alg-S5.

    Science.gov (United States)

    Mohapatra, Bidyut R

    2017-05-01

    In an effort to screen out the alginolytic and cellulolytic bacteria from the putrefying invasive seaweed Sargassum species accumulated off Barbados' coast, a potent bacterial strain was isolated. This bacterium, which simultaneously produced alginate lyase and cellulase, was identified as Exiguobacterium sp. Alg-S5 via the phylogenetic approach targeting the 16S rRNA gene. The co-produced alginate lyase and cellulase exhibited maximal enzymatic activity at pH 7.5 and at 40°C and 45°C, respectively. The K m and V max values recorded as 0.91mg/mL and 21.8U/mg-protein, respectively, for alginate lyase, and 10.9mg/mL and 74.6U/mg-protein, respectively, for cellulase. First order kinetic analysis of the thermal denaturation of the co-produced alginate lyase and cellulase in the temperature range from 40°C to 55°C revealed that both the enzymes were thermodynamically efficient by displaying higher activation energy and enthalpy of denaturation. These enzymatic properties indicate the potential industrial importance of this bacterium in algal biomass conversion. This appears to be the first report on assessing the efficacy of a bacterium for the co-production of alginate lyase and cellulase. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Efficient and Highly Aldehyde Selective Wacker Oxidation

    KAUST Repository

    Teo, Peili; Wickens, Zachary K.; Dong, Guangbin; Grubbs, Robert H.

    2012-01-01

    A method for efficient and aldehyde-selective Wacker oxidation of aryl-substituted olefins using PdCl 2(MeCN) 2, 1,4-benzoquinone, and t-BuOH in air is described. Up to a 96% yield of aldehyde can be obtained, and up to 99% selectivity can be achieved with styrene-related substrates. © 2012 American Chemical Society.

  3. Efficient and Highly Aldehyde Selective Wacker Oxidation

    KAUST Repository

    Teo, Peili

    2012-07-06

    A method for efficient and aldehyde-selective Wacker oxidation of aryl-substituted olefins using PdCl 2(MeCN) 2, 1,4-benzoquinone, and t-BuOH in air is described. Up to a 96% yield of aldehyde can be obtained, and up to 99% selectivity can be achieved with styrene-related substrates. © 2012 American Chemical Society.

  4. Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus.

    Science.gov (United States)

    Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

    2017-01-01

    Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic

  5. Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus*

    Science.gov (United States)

    Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

    2017-01-01

    Background Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further

  6. Crystal structure and characterization of a novel L-serine ammonia-lyase from Rhizomucor miehei

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhen [College of Food Science and Nutritional Engineering, Beijing Advanced Innovation Center of Food Nutrition and Human Health, China Agricultural University, Beijing 100083 (China); Yan, Qiaojuan [College of Engineering, China Agricultural University, Beijing 100083 (China); Ma, Qingjun [Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Jiang, Zhengqiang, E-mail: zhqjiang@cau.edu.cn [College of Food Science and Nutritional Engineering, Beijing Advanced Innovation Center of Food Nutrition and Human Health, China Agricultural University, Beijing 100083 (China)

    2015-10-23

    L-serine ammonia-lyase, as a member of the β-family of pyridoxal-5′-phosphate (PLP) dependent enzymes, catalyzes the conversion of L-serine (L-threonine) to pyruvate (α-ketobutyrate) and ammonia. The crystal structure of L-serine ammonia-lyase from Rhizomucor miehei (RmSDH) was solved at 1.76 Å resolution by X-ray diffraction method. The overall structure of RmSDH had the characteristic β-family PLP dependent enzyme fold. It consisted of two distinct domains, both of which show the typical open twisted α/β structure. A PLP cofactor was located in the crevice between the two domains, which was attached to Lys52 by a Schiff-base linkage. Unique residue substitutions (Gly78, Pro79, Ser146, Ser147 and Thr312) were discovered at the catalytic site of RmSDH by comparison of structures of RmSDH and other reported eukaryotic L-serine ammonia-lyases. Optimal pH and temperature of the purified RmSDH were 7.5 and 40 °C, respectively. It was stable in the pH range of 7.0–9.0 and at temperatures below 40 °C. This is the first crystal structure of a fungal L-serine ammonia-lyase. It will be useful to study the catalytic mechanism of β-elimination enzymes and will provide a basis for further enzyme engineering. - Highlights: • The crystal structure of a fungal L-serine ammonia-lyase (RmSDH) was solved. • Five unique residue substitutions are found at the catalytic site of RmSDH. • RmSDH was expressed in Pichia. pastoris and biochemically characterized. • RmSDH has potential application in splitting D/L-serine.

  7. Cystathionine .gamma.-lyase: Clinical, metabolic, genetic, and structural studies

    Czech Academy of Sciences Publication Activity Database

    Kraus, J. P.; Hašek, Jindřich; Kožich, V.; Collard, R.; Venezia, S.; Janošíková, B.; Wang, J.; Stabler, S. P.; Allen, R. H.; Jakobs, C.; Finn, C. T.; Chien, Y. H.; Hwu, W. L.; Hegele, R. A.; Mudd, S. H.

    2009-01-01

    Roč. 97, č. 4 (2009), s. 250-259 ISSN 1096-7192 R&D Projects: GA ČR GA305/07/1073 Institutional research plan: CEZ:AV0Z40500505 Keywords : cystathionine gamma-lyase * cystathioninuria * hypercystathioninemia Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.897, year: 2009

  8. Phenylalanine ammonia-lyase (PAL) gene activity in response to ...

    African Journals Online (AJOL)

    Phenylalanine ammonia-lyase (PAL) catalyzes the biosynthesis of rosmarinic acid (RA), tyrosine and phenylalanine are the precursors of RA, while proline drives metabolite precursors toward Shikimate and phenylpropanoid pathway ending with the production of RA. The aim of this study was to investigate the PAL gene ...

  9. Processes for the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity. More particularly, the present invention pertains to polypeptides having tyrosine ammonia lyase activity and high...... substrate specificity towards tyrosine, which makes them particularly suitable in the production of p-coumaric acid and other hydroxycinnamic acids. The present invention thus provides processes for the production of p-coumaric acid and other hydroxycinnamic acids employing these polypeptides as well...

  10. Hematopoietic sphingosine 1-phosphate lyase deficiency decreases atherosclerotic lesion development in LDL-receptor deficient mice.

    Directory of Open Access Journals (Sweden)

    Martine Bot

    Full Text Available AIMS: Altered sphingosine 1-phosphate (S1P homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1(-/- deficiency on leukocyte subsets relevant to atherosclerosis. METHODS AND RESULTS: LDL receptor deficient mice that were transplanted with Sgpl1(-/- bone marrow showed disrupted S1P gradients translating into lymphopenia and abrogated lymphocyte mitogenic and cytokine response as compared to controls. Remarkably however, Sgpl1(-/- chimeras displayed mild monocytosis, due to impeded stromal retention and myelopoiesis, and plasma cytokine and macrophage expression patterns, that were largely compatible with classical macrophage activation. Collectively these two phenotypic features of Sgpl1 deficiency culminated in diminished atherogenic response. CONCLUSIONS: Here we not only firmly establish the critical role of hematopoietic S1P lyase in controlling S1P levels and T cell trafficking in blood and lymphoid tissue, but also identify leukocyte Sgpl1 as critical factor in monocyte macrophage differentiation and function. Its, partly counterbalancing, pro- and anti-inflammatory activity spectrum imply that intervention in S1P lyase function in inflammatory disorders such as atherosclerosis should be considered with caution.

  11. Characterization of C-S lyase from Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 and its potential role in food flavour applications.

    Science.gov (United States)

    Allegrini, Alessandra; Astegno, Alessandra; La Verde, Valentina; Dominici, Paola

    2017-04-01

    Volatile thiols have substantial impact on the aroma of many beverages and foods. Thus, the control of their formation, which has been linked to C-S lyase enzymatic activities, is of great significance in industrial applications involving food flavours. Herein, we have carried out a spectroscopic and functional characterization of a putative pyridoxal 5'-phosphate (PLP)-dependent C-S lyase from the lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 (LDB C-S lyase). Recombinant LDB C-S lyase exists as a tetramer in solution and shows spectral properties of enzymes containing PLP as cofactor. The enzyme has a broad substrate specificity toward sulphur-containing amino acids with aminoethyl-L-cysteine and L-cystine being the most effective substrates over L-cysteine and L-cystathionine. Notably, the protein also reveals cysteine-S-conjugate β-lyase activity in vitro, and is able to cleave a cysteinylated substrate precursor into the corresponding flavour-contributing thiol, with a catalytic efficiency higher than L-cystathionine. Contrary to similar enzymes of other lactic acid bacteria however, LDB C-S lyase is not capable of α,γ-elimination activity towards L-methionine to produce methanethiol, which is a significant compound in flavour development. Based on our results, future developments can be expected regarding the flavour-forming potential of Lactobacillus C-S lyase and its use in enhancing food flavours. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  12. Novel Pectate Lyase Genes of Heterodera glycines Play Key Roles in the Early Stage of Parasitism.

    Directory of Open Access Journals (Sweden)

    Huan Peng

    Full Text Available Pectate lyases are known to play a key role in pectin degradation by catalyzing the random cleavage of internal polymer linkages (endo-pectinases. In this paper, four novel cDNAs, designated Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7, that encode pectate lyases were cloned and characterized from the soybean cyst nematode, Heterodera glycines. The predicted protein sequences of HG-PEL-3, HG-PEL-4 and HG-PEL-6 differed significantly in both their amino acid sequences and their genomic structures from other pectate lyases of H. glycines (HG-PEL-1, HG-PEL-2 and HG-PEL-7. A phylogenetic study revealed that the pectate lyase proteins of H. glycines are clustered into distinct clades and have distinct numbers and positioning of introns, which suggests that the pectate lyase genes of H. glycines may have evolved from at least two ancestral genes. A Southern blot analysis revealed that multiple Hg-pel-6-like genes were present in the H. glycines genome. In situ hybridization showed that four novel pectate lyases (Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7 were actively transcribed in the subventral esophageal gland cells. A semi-quantitative RT-PCR assay supported the finding that the expression of these genes was strong in the egg, pre-parasitic second-stage juvenile (J2 and early parasitic J2 stages and that it declined in further developmental stages of the nematode. This expression pattern suggests that these proteins play a role in the migratory phase of the nematode life cycle. Knocking down Hg-pel-6 using in vitro RNA interference resulted in a 46.9% reduction of the number of nematodes that invaded the plants and a 61.5% suppression of the development of H. glycines females within roots compared to the GFP-dsRNA control. Plant host-derived RNAi induced the silencing of the Hg-pel-6gene, which significantly reduced the nematode infection levels at 7 Days post inoculation (dpi. Similarly, this procedure reduced the number of female adults at 40 dpi

  13. ARA-aldehyde and ABA-trans-diol in apple fruits

    International Nuclear Information System (INIS)

    Rock, C.D.; Zeevaart, J.A.D.

    1989-01-01

    We have isolated ABA-aldehyde and ABA-t-diol from postharvest apple fruits, cv. Granny Smith and confirmed their structure by GC-MS. These putative ABA biosynthetic precursors incorporate 18 O to a similar degree as ABA during 48 hours under 18 O 2 atmospheres. The presence of significant amounts of ABA-aldehyde can explain the unique 18 O labeling pattern of ABA in this tissue, where a majority of ABA molecules containing 18 O is labeled in the 1'-hydroxyl group and not in the side chain carboxyl group, the primary site of incorporation for stressed leaves. Exchange of the carbonyl oxygen of ABA-aldehyde with water would decrease 18 O enrichment in the side chain. Results of 18 O 2 experiments and feeding studies using hexadeutero-ABA-aldehyde will be presented and the biosynthetic relationship of these compounds discussed

  14. Application of heterocyclic aldehydes as components in Ugi–Smiles couplings

    Directory of Open Access Journals (Sweden)

    Katelynn M. Mason

    2016-09-01

    Full Text Available Efficient one-pot Ugi–Smiles couplings are reported for the use of furyl-substituted aldehyde components. In the presence of these heterocyclic aldehydes, reactions tolerated variations in amine components and led to either isolated N-arylamide Ugi–Smiles adducts or N-arylepoxyisoindolines, products of tandem Ugi–Smiles Diels–Alder cyclizations, in moderate yields. A thienyl-substituted aldehyde was also a competent component for Ugi–Smiles adduct formation.

  15. Reduction of Aldehydes and Ketones by Sodium Dithionite

    NARCIS (Netherlands)

    Vries, Johannes G. de; Kellogg, Richard M.

    1980-01-01

    Conditions have been developed for the effective reduction of aldehydes and ketones by sodium dithionite, Na2S2O4. Complete reduction of simple aldehydes and ketones can be achieved with excess Na2S2O4 in H2O/dioxane mixtures at reflux temperature. Some aliphatic ketones, for example, pentanone and

  16. Priming ammonia lyases and aminomutases for industrial and therapeutic applications

    NARCIS (Netherlands)

    Heberling, Matthew M.; Wu, Bian; Bartsch, Sebastian; Janssen, Dick B.

    Ammonia lyases (AL) and aminomutases (AM) are emerging in green synthetic routes to chiral amines and an AL is being explored as an enzyme therapeutic for treating phenylketonuria and cancer. Although the restricted substrate range of the wild-type enzymes limits their widespread application, the

  17. One-step purification and characterization of alginate lyase from a clinical Pseudomonas aeruginosa with destructive activity on bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Parinaz Ghadam

    2017-05-01

    Full Text Available Objective(s: Pseudomonas aeruginosais a Gram-negative and aerobic rod bacterium that displays mucoid and non-mucoid phenotype. Mucoid strains secrete alginate, which is the main agent of biofilms in chronic P. aeruginosa infections, show high resistance to antibiotics; consequently, the biological disruption of mucoid P. aeruginosa biofilms is an attractive area of study for researchers. Alginate lyase gene (algl is a member of alginate producing operon which by glycosidase activity produces primer for other enzymes in this cluster. Also this activity can destroy the extracellular alginate; therefore this enzyme participates in alginate production and destruction pathway. Alginate lyase causes detachment of a biofilm by reducing its adhesion to the surfaces, and increases phagocytosis and antibiotic susceptibility. In this study, alginate lyase was purified in just one step and its properties were investigated. Materials and Methods: The purification was done by affinity chromatography, analysed by SDS-PAGE, and its effect on P. aeruginosa biofilms was surveyed by micro titer plate assay and SEM. The substrate specificity of the enzyme was determined by PCR. Results: Alginate lyase from isolate 48 was purified in one step. It is more thermally resistant than alginate lyase from Pseudomonas aeruginosa PAO1 and poly M, poly G and poly MG alginate were the substrate of this enzyme. Moreover, it has an eradication effect on biofilms from P. aeruginosa 48 and PAO1. Conclusion: In this study an alginate lyase with many characteristics suitable in medicine such as thermal stability, effective on poly M alginate, and bacterial biofilm destructive was introduced and purified.

  18. Correlation between the cystathionine-r-lyase (CES) and the ...

    African Journals Online (AJOL)

    Background: The infection of Helicobacter pylori (H. pylori) is one of the most important causes of gastric ulcer disease. The role of hydrogen sulfide (H2S) production in H. pylori-induced gastric ulcer disease. Aim: The expression of cystathionine-γ-lyase (CSE) was determined, and correlated with the severity of gastric ulcer ...

  19. The oxidation of the aldehyde groups in dialdehyde starch

    NARCIS (Netherlands)

    Haaksman, I.K.; Besemer, A.C.; Jetten, J.M.; Timmermans, J.W.; Slaghek, T.M.

    2006-01-01

    This paper describes the difference in relative reactivity of the aldehyde groups present in dialdehyde starch towards different oxidising agents. The oxidation of dialdehyde starch with peracetic acid and sodium bromide leads to only partial oxidation to give mono-aldehyde-carboxy starch, while

  20. Monitoring of fatty aldehyde dehydrogenase by formation of pyrenedecanoic acid from pyrenedecanal

    NARCIS (Netherlands)

    Keller, Markus A.; Watschinger, Katrin; Golderer, Georg; Maglione, Manuel; Sarg, Bettina; Lindner, Herbert H.; Werner-Felmayer, Gabriele; Terrinoni, Alessandro; Wanders, Ronald J. A.; Werner, Ernst R.

    2010-01-01

    Fatty aldehyde dehydrogenase (EC 1.2.1.48) converts long-chain fatty aldehydes to the corresponding acids. Deficiency in this enzyme causes the Sjogren Larsson Syndrome, a rare inherited disorder characterized by ichthyosis, spasticity, and mental retardation. Using a fluorescent aldehyde,

  1. Ubiquitin-aldehyde: a general inhibitor of ubiquitin-recycling processes

    International Nuclear Information System (INIS)

    Hershko, A.; Rose, I.A.

    1987-01-01

    The generation and characterization of ubiquitin (Ub)-aldehyde, a potent inhibitor of Ub-C-terminal hydrolase, has previously been reported. The authors examine the action of this compound on the Ub-mediated proteolytic pathway using the system derived from rabbit reticulocytes. Addition of Ub-aldehyde was found to strongly inhibit breakdown of added 125 I-labeled lysozyme, but inhibition was overcome by increasing concentrations of Ub. The following evidence shows the effect of Ub-aldehyde on protein breakdown to be indirectly caused by its interference with the recycling of Ub, leading to exhaustion of the supply of free Ub: (i) Ub-aldehyde markedly increased the accumulation of Ub-protein conjugates coincident with a much decreased rate of conjugate breakdown; (ii) release of Ub from isolated Ub-protein conjugates in the absence of ATP (and therefore not coupled to protein degradation) is markedly inhibited by Ub-aldehyde. On the other hand, the ATP-dependent degradation of the protein moiety of Ub conjugates, which is an integral part of the proteolytic process, is not inhibited by this agent; (iii) direct measurement of levels of free Ub showed a rapid disappearance caused by the inhibitor. The Ub is found to be distributed in derivatives of a wide range of molecular weight classes. It thus seems that Ub-aldehyde, previously demonstrated to inhibit the hydrolysis of Ub conjugates of small molecules, also inhibits the activity of a series of enzymes that regenerate free Ub from adducts with proteins and intermediates in protein breakdown

  2. In vitro assessment of human airway toxicity from major aldehydes in automotive emissions

    Energy Technology Data Exchange (ETDEWEB)

    Grafstroem, R.C. [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

    1997-09-01

    Automotive exhausts can significantly contribute to the levels of reactive aldehydes, including formaldehyde, acetaldehyde and acrolein, in urban air. The use of alcohols as an alternative fuel for gasoline or diesel may further increase these emissions. Since it is unclear if aldehyde inhalation may induce pathological states, including cancer, in human airways, the toxic properties of the above-mentioned aldehydes were studied in cultured target cell types. Each aldehyde modified vital cellular functions in a dose-dependent manner, and invariably inhibited growth and induced abnormal terminal differentiation. Decreases of cellular thiols and increases of intracellular Ca{sup 2+} were observed, and moreover, variable types and amounts of short-lived or persistent genetic damage were induced. The concentrations required for specified levels of a particular type of injury varied up to 10000-fold among the aldehydes. Overall, distinctive patterns of cytopathological activity were observed, which differed both qualitatively and quantitatively among the aldehydes. Finally, aldehydes inhibited DNA repair processes and increased cytotoxicity and mutagenesis in synergy with other known toxicants, indicating that aldehydes may also enhance damage by other constituents in automotive exhausts. In summary, the aldehydes, notably {sup m}u{sup M}-mM formaldehyde, caused pathological effects and induced mechanisms that relate to acute toxicity and cancer development in airway epithelial cells. Since `no-effect` levels may not exist for carcinogenic agents, the overall results support a need for elimination of aldehydes in automotive exhausts. 41 refs

  3. Direct, enantioselective α-alkylation of aldehydes using simple olefins.

    Science.gov (United States)

    Capacci, Andrew G; Malinowski, Justin T; McAlpine, Neil J; Kuhne, Jerome; MacMillan, David W C

    2017-11-01

    Although the α-alkylation of ketones has already been established, the analogous reaction using aldehyde substrates has proven surprisingly elusive. Despite the structural similarities between the two classes of compounds, the sensitivity and unique reactivity of the aldehyde functionality has typically required activated substrates or specialized additives. Here, we show that the synergistic merger of three catalytic processes-photoredox, enamine and hydrogen-atom transfer (HAT) catalysis-enables an enantioselective α-aldehyde alkylation reaction that employs simple olefins as coupling partners. Chiral imidazolidinones or prolinols, in combination with a thiophenol, iridium photoredox catalyst and visible light, have been successfully used in a triple catalytic process that is temporally sequenced to deliver a new hydrogen and electron-borrowing mechanism. This multicatalytic process enables both intra- and intermolecular aldehyde α-methylene coupling with olefins to construct both cyclic and acyclic products, respectively. With respect to atom and step-economy ideals, this stereoselective process allows the production of high-value molecules from feedstock chemicals in one step while consuming only photons.

  4. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of distillates... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant from which distillates were...

  5. Characterization of the N-linked glycosylation site of recombinant pectate lyase

    NARCIS (Netherlands)

    Colangelo, J.; Licon, V.; Benen, J.A.E.; Visser, J.; Bergmann, C.; Orlando, R.

    1999-01-01

    Recombinant pectate lyase from Aspergillus niger was overexpressed in Aspergillus nidulans. The two recombinant proteins produced differed in molecular mass by 1200 Da, which suggested that the larger molecular weight protein was glycosylated. The deduced amino acid sequence was searched for

  6. Biochemical, Kinetic, and Spectroscopic Characterization of Ruegeria pomeroyi DddW--A Mononuclear Iron-Dependent DMSP Lyase.

    Directory of Open Access Journals (Sweden)

    Adam E Brummett

    Full Text Available The osmolyte dimethylsulfoniopropionate (DMSP is a key nutrient in marine environments and its catabolism by bacteria through enzymes known as DMSP lyases generates dimethylsulfide (DMS, a gas of importance in climate regulation, the sulfur cycle, and signaling to higher organisms. Despite the environmental significance of DMSP lyases, little is known about how they function at the mechanistic level. In this study we biochemically characterize DddW, a DMSP lyase from the model roseobacter Ruegeria pomeroyi DSS-3. DddW is a 16.9 kDa enzyme that contains a C-terminal cupin domain and liberates acrylate, a proton, and DMS from the DMSP substrate. Our studies show that as-purified DddW is a metalloenzyme, like the DddQ and DddP DMSP lyases, but contains an iron cofactor. The metal cofactor is essential for DddW DMSP lyase activity since addition of the metal chelator EDTA abolishes its enzymatic activity, as do substitution mutations of key metal-binding residues in the cupin motif (His81, His83, Glu87, and His121. Measurements of metal binding affinity and catalytic activity indicate that Fe(II is most likely the preferred catalytic metal ion with a nanomolar binding affinity. Stoichiometry studies suggest DddW requires one Fe(II per monomer. Electronic absorption and electron paramagnetic resonance (EPR studies show an interaction between NO and Fe(II-DddW, with NO binding to the EPR silent Fe(II site giving rise to an EPR active species (g = 4.29, 3.95, 2.00. The change in the rhombicity of the EPR signal is observed in the presence of DMSP, indicating that substrate binds to the iron site without displacing bound NO. This work provides insight into the mechanism of DMSP cleavage catalyzed by DddW.

  7. Different specificities of two aldehyde dehydrogenases from Saccharomyces cerevisiae var. boulardii.

    Science.gov (United States)

    Datta, Suprama; Annapure, Uday S; Timson, David J

    2017-04-30

    Aldehyde dehydrogenases play crucial roles in the detoxification of exogenous and endogenous aldehydes by catalysing their oxidation to carboxylic acid counterparts. The present study reports characterization of two such isoenzymes from the yeast Saccharomyces cerevisiae var. boulardii (NCYC 3264), one mitochondrial (Ald4p) and one cytosolic (Ald6p). Both Ald4p and Ald6p were oligomeric in solution and demonstrated positive kinetic cooperativity towards aldehyde substrates. Wild-type Ald6p showed activity only with aliphatic aldehydes. Ald4p, on the contrary, showed activity with benzaldehyde along with a limited range of aliphatic aldehydes. Inspection of modelled structure of Ald6p revealed that a bulky amino acid residue (Met 177 , compared with the equivalent residue Leu 196 in Ald4p) might cause steric hindrance of cyclic substrates. Therefore, we hypothesized that specificities of the two isoenzymes towards aldehyde substrates were partly driven by steric hindrance in the active site. A variant of wild-type Ald6p with the Met 177 residue replaced by a valine was also characterized to address to the hypothesis. It showed an increased specificity range and a gain of activity towards cyclohexanecarboxaldehyde. It also demonstrated an increased thermal stability when compared with both the wild-types. These data suggest that steric bulk in the active site of yeast aldehyde dehydrogenases is partially responsible for controlling specificity. © 2017 The Author(s).

  8. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  9. Structural and Kinetic Properties of the Aldehyde Dehydrogenase NahF, a Broad Substrate Specificity Enzyme for Aldehyde Oxidation.

    Science.gov (United States)

    Coitinho, Juliana B; Pereira, Mozart S; Costa, Débora M A; Guimarães, Samuel L; Araújo, Simara S; Hengge, Alvan C; Brandão, Tiago A S; Nagem, Ronaldo A P

    2016-09-27

    The salicylaldehyde dehydrogenase (NahF) catalyzes the oxidation of salicylaldehyde to salicylate using NAD(+) as a cofactor, the last reaction of the upper degradation pathway of naphthalene in Pseudomonas putida G7. The naphthalene is an abundant and toxic compound in oil and has been used as a model for bioremediation studies. The steady-state kinetic parameters for oxidation of aliphatic or aromatic aldehydes catalyzed by 6xHis-NahF are presented. The 6xHis-NahF catalyzes the oxidation of aromatic aldehydes with large kcat/Km values close to 10(6) M(-1) s(-1). The active site of NahF is highly hydrophobic, and the enzyme shows higher specificity for less polar substrates than for polar substrates, e.g., acetaldehyde. The enzyme shows α/β folding with three well-defined domains: the oligomerization domain, which is responsible for the interlacement between the two monomers; the Rossmann-like fold domain, essential for nucleotide binding; and the catalytic domain. A salicylaldehyde molecule was observed in a deep pocket in the crystal structure of NahF where the catalytic C284 and E250 are present. Moreover, the residues G150, R157, W96, F99, F274, F279, and Y446 were thought to be important for catalysis and specificity for aromatic aldehydes. Understanding the molecular features responsible for NahF activity allows for comparisons with other aldehyde dehydrogenases and, together with structural information, provides the information needed for future mutational studies aimed to enhance its stability and specificity and further its use in biotechnological processes.

  10. Microbial β-etherases and glutathione lyases for lignin valorisation in biorefineries: current state and future perspectives.

    Science.gov (United States)

    Husarcíková, Jana; Voß, Hauke; Domínguez de María, Pablo; Schallmey, Anett

    2018-05-04

    Lignin is the major aromatic biopolymer in nature, and it is considered a valuable feedstock for the future supply of aromatics. Hence, its valorisation in biorefineries is of high importance, and various chemical and enzymatic approaches for lignin depolymerisation have been reported. Among the enzymes known to act on lignin, β-etherases offer the possibility for a selective cleavage of the β-O-4 aryl ether bonds present in lignin. These enzymes, together with glutathione lyases, catalyse a reductive, glutathione-dependent ether bond cleavage displaying high stereospecificity. β-Etherases and glutathione lyases both belong to the superfamily of glutathione transferases, and several structures have been solved recently. Additionally, different approaches for their application in lignin valorisation have been reported in the last years. This review gives an overview on the current knowledge on β-etherases and glutathione lyases, their biochemical and structural features, and critically discusses their potential for application in biorefineries.

  11. Detoxification of aldehydes by histidine-containing dipeptides: from chemistry to clinical implications

    Science.gov (United States)

    Xie, Zhengzhi; Baba, Shahid P.; Sweeney, Brooke R.; Barski, Oleg A.

    2015-01-01

    Aldehydes are generated by oxidized lipids and carbohydrates at increased levels under conditions of metabolic imbalance and oxidative stress during atherosclerosis, myocardial and cerebral ischemia, diabetes, neurodegenerative diseases and trauma. In most tissues, aldehydes are detoxified by oxidoreductases that catalyze the oxidation or the reduction of aldehydes or enzymatic and nonenzymatic conjugation with low molecular weight thiols and amines, such as glutathione and histidine dipeptides. Histidine dipeptides are present in micromolar to millimolar range in the tissues of vertebrates, where they are involved in a variety of physiological functions such as pH buffering, metal chelation, oxidant and aldehyde scavenging. Histidine dipeptides such as carnosine form Michael adducts with lipid-derived unsaturated aldehydes, and react with carbohydrate-derived oxo- and hydroxy- aldehydes forming products of unknown structure. Although these peptides react with electrophilic molecules at lower rate than glutathione, they can protect glutathione from modification by oxidant and they may be important for aldehyde quenching in glutathione-depleted cells or extracellular space where glutathione is scarce. Consistent with in vitro findings, treatment with carnosine has been shown to diminish ischemic injury, improve glucose control, ameliorate the development of complications in animal models of diabetes and obesity, promote wound healing and decrease atherosclerosis. The protective effects of carnosine have been linked to its anti-oxidant properties, it ability to promote glycolysis, detoxify reactive aldehydes and enhance histamine levels. Thus, treatment with carnosine and related histidine dipeptides may be a promising strategy for the prevention and treatment of diseases associated with high carbonyl load. PMID:23313711

  12. Highly Active and Specific Tyrosine Ammonia-Lyases from Diverse Origins Enable Enhanced Production of Aromatic Compounds in Bacteria and Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Jendresen, Christian Bille; Stahlhut, Steen Gustav; Li, Mingji

    2015-01-01

    Phenylalanine and tyrosine ammonia-lyases form cinnamic acid and p-coumaric acid, which are precursors of a wide range of aromatic compounds of biotechnological interest. Lack of highly active and specific tyrosine ammonia-lyases has previously been a limitation in metabolic engineering approaches...

  13. Pectinolytic bacteria and their secreted pectate lyases: agents for the maceration and solubilization of phytomass for fuels production

    Energy Technology Data Exchange (ETDEWEB)

    Preston, J.F. III; Rice, J.D.; Chow, M.C. (Florida Univ., Gainesville, FL (United States). Dept. of Microbiology and Cell Science)

    1993-01-01

    The objectives of this research have been to identify the pectinolytic enzymes secreted by bacteria and apply these towards the enhanced maceration and solubilization of plant material, focusing on the pectate lyases secreted by the phytopathogenic strains of Erwinia chrysanthemi, the ruminant resident Lachnospira multiparus, and the wood digestor isolate, Clostridium populeti. An HPLC approach has been developed that permits the kinetic analysis of each enzyme with respect to the formation of individual products during the pectate depolymerization process. This approach has demonstrated that each of these organisms secretes a nonrandom trimer-generating pectate lyase with a combination of endolytic and exolytic depolymerizing mechanisms. Two different strains of E. chrysanthemi secrete a battery of pectate lyases that include random endolytic as well as nonrandom dimer - and nonrandom trimer-generating endolytic/exolytic mechanisms. (author)

  14. Catalytic Mechanisms and Biocatalytic Applications of Aspartate and Methylaspartate Ammonia Lyases

    NARCIS (Netherlands)

    de Villiers, Marianne; Veetil, Vinod Puthan; Raj, Hans; de Villiers, Jandre; Poelarends, Gerrit J.

    2012-01-01

    Ammonia lyases catalyze the formation of alpha-beta-unsaturated bonds by the elimination of ammonia from their substrates. This conceptually straightforward reaction has been the emphasis of many studies, with the main focus on the catalytic mechanism of these enzymes and/or the use of these enzymes

  15. Thermal, Catalytic Conversion of Alkanes to Linear Aldehydes and Linear Amines.

    Science.gov (United States)

    Tang, Xinxin; Jia, Xiangqing; Huang, Zheng

    2018-03-21

    Alkanes, the main constituents of petroleum, are attractive feedstocks for producing value-added chemicals. Linear aldehydes and amines are two of the most important building blocks in the chemical industry. To date, there have been no effective methods for directly converting n-alkanes to linear aldehydes and linear amines. Here, we report a molecular dual-catalyst system for production of linear aldehydes via regioselective carbonylation of n-alkanes. The system is comprised of a pincer iridium catalyst for transfer-dehydrogenation of the alkane using t-butylethylene or ethylene as a hydrogen acceptor working sequentially with a rhodium catalyst for olefin isomerization-hydroformylation with syngas. The system exhibits high regioselectivity for linear aldehydes and gives high catalytic turnover numbers when using ethylene as the acceptor. In addition, the direct conversion of light alkanes, n-pentane and n-hexane, to siloxy-terminated alkyl aldehydes through a sequence of Ir/Fe-catalyzed alkane silylation and Ir/Rh-catalyzed alkane carbonylation, is described. Finally, the Ir/Rh dual-catalyst strategy has been successfully applied to regioselective alkane aminomethylation to form linear alkyl amines.

  16. Flavoring Compounds Dominate Toxic Aldehyde Production during E-Cigarette Vaping.

    Science.gov (United States)

    Khlystov, Andrey; Samburova, Vera

    2016-12-06

    The growing popularity of electronic cigarettes (e-cigarettes) raises concerns about the possibility of adverse health effects to primary users and people exposed to e-cigarette vapors. E-Cigarettes offer a very wide variety of flavors, which is one of the main factors that attract new, especially young, users. How flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of e-cigarette vapors is practically unknown. Although e-cigarettes are marketed as safer alternatives to traditional cigarettes, several studies have demonstrated formation of toxic aldehydes in e-cigarette vapors during vaping. So far, aldehyde formation has been attributed to thermal decomposition of the main components of e-cigarette e-liquids (propylene glycol and glycerol), while the role of flavoring compounds has been ignored. In this study, we have measured several toxic aldehydes produced by three popular brands of e-cigarettes with flavored and unflavored e-liquids. We show that, within the tested e-cigarette brands, thermal decomposition of flavoring compounds dominates formation of aldehydes during vaping, producing levels that exceed occupational safety standards. Production of aldehydes was found to be exponentially dependent on concentration of flavoring compounds. These findings stress the need for a further, thorough investigation of the effect of flavoring compounds on the toxicity of e-cigarettes.

  17. Cyclodextrin Aldehydes are Oxidase Mimics

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Bjerre, Jeannette; Bols, Mikael

    2009-01-01

    Cyclodextrins containing 6-aldehyde groups were found to catalyse oxidation of aminophenols in the presence of hydrogen peroxide. The catalysis followed Michaelis-Menten kinetics and is related to the catalysis previously observed with cyclodextrin ketones. A range of different cyclodextrin aldeh...

  18. S1P lyase in thymic perivascular spaces promotes egress of mature thymocytes via up-regulation of S1P receptor 1.

    Science.gov (United States)

    Maeda, Yasuhiro; Yagi, Hideki; Takemoto, Kana; Utsumi, Hiroyuki; Fukunari, Atsushi; Sugahara, Kunio; Masuko, Takashi; Chiba, Kenji

    2014-05-01

    Sphingosine 1-phosphate (S1P) and S1P receptor 1 (S1P1) play an important role in the egress of mature CD4 or CD8 single-positive (SP) thymocytes from the thymus. Fingolimod hydrochloride (FTY720), an S1P1 functional antagonist, induced significant accumulation of CD62L(high)CD69(low) mature SP thymocytes in the thymic medulla. Immunohistochemical staining using anti-S1P1 antibody revealed that S1P1 is predominantly expressed on thymocytes in the thymic medulla and is strongly down-regulated even at 3h after FTY720 administration. 2-Acetyl-4-tetrahydroxybutylimidazole (THI), an S1P lyase inhibitor, also induced accumulation of mature SP thymocytes in the thymic medulla with an enlargement of the perivascular spaces (PVS). At 6h after THI administration, S1P1-expressing thymocytes reduced partially as if to form clusters and hardly existed in the proximity of CD31-expressing blood vessels in the thymic medulla, suggesting S1P lyase expression in the cells constructing thymic medullary PVS. To determine the cells expressing S1P lyase in the thymus, we newly established a mAb (YK19-2) specific for mouse S1P lyase. Immunohistochemical staining with YK19-2 revealed that S1P lyase is predominantly expressed in non-lymphoid thymic stromal cells in the thymic medulla. In the thymic medullary PVS, S1P lyase was expressed in ER-TR7-positive cells (reticular fibroblasts and pericytes) and CD31-positive vascular endothelial cells. Our findings suggest that S1P lyase expressed in the thymic medullary PVS keeps the tissue S1P concentration low around the vessels and promotes thymic egress via up-regulation of S1P1.

  19. Sugar-cane juice induces pectin lyase and polygalacturonase in Penicillium griseoroseum

    Directory of Open Access Journals (Sweden)

    Minussi Rosana Cristina

    1998-01-01

    Full Text Available The use of other inducers as substitutes for pectin was studied aiming to reduce the production costs of pectic enzymes. The effects of sugar-cane juice on the production of pectin lyase (PL and polygalacturonase (PG by Penicillium griseoroseum were investigated. The fungus was cultured in a mineral medium (pH 6.3 in a rotary shaker (150 rpm for 48 h at 25oC. Culture media were supplemented with yeast extract and sucrose or sugar-cane juice. Sugar-cane juice added singly to the medium promoted higher PL activity and mycelial dry weight when compared to pectin and the use of sugar-cane juice and yeast extract yielded levels of PG activity that were similar to those obtained with sucrose-yeast extract or pectin. The results indicated that, even at low concentrations, sugar-cane juice was capable of inducing pectin lyase and polygalacturonase with no cellulase activity in P. griseoroseum.

  20. Crystallization and preliminary X-ray analysis of argininosuccinate lyase from Streptococcus mutans

    International Nuclear Information System (INIS)

    Cao, Yan-Li; Li, Gui-Lan; Wang, Kai-Tuo; Zhang, Hong-Yin; Li, Lan-Fen

    2011-01-01

    Crystals of argininosuccinate lyase from S. mutans were obtained and X-ray data were collected to 2.5 Å resolution in space group R3. Argininosuccinate lyase (ASL) is an important enzyme in arginine synthesis and the urea cycle, which are highly conserved from bacteria to eukaryotes. The gene encoding Streptococcus mutans ASL (smASL) was amplified and cloned into expression vector pET28a. The recombinant smASL protein was expressed in a soluble form in Escherichia coli strain BL21 (DE3) and purified to homogeneity by two-step column chromatography. Crystals suitable for X-ray analysis were obtained and X-ray diffraction data were collected to a resolution of 2.5 Å. The crystals belonged to space group R3, with unit-cell parameters a = b = 254.5, c = 78.3 Å

  1. Cloning and Sequence Analysis of Vibrio halioticoli Genes Encoding Three Types of Polyguluronate Lyase.

    Science.gov (United States)

    Sugimura; Sawabe; Ezura

    2000-01-01

    The alginate lyase-coding genes of Vibrio halioticoli IAM 14596(T), which was isolated from the gut of the abalone Haliotis discus hannai, were cloned using plasmid vector pUC 18, and expressed in Escherichia coli. Three alginate lyase-positive clones, pVHB, pVHC, and pVHE, were obtained, and all clones expressed the enzyme activity specific for polyguluronate. Three genes, alyVG1, alyVG2, and alyVG3, encoding polyguluronate lyase were sequenced: alyVG1 from pVHB was composed of a 1056-bp open reading frame (ORF) encoding 352 amino acid residues; alyVG2 gene from pVHC was composed of a 993-bp ORF encoding 331 amino acid residues; and alyVG3 gene from pVHE was composed of a 705-bp ORF encoding 235 amino acid residues. Comparison of nucleotide and deduced amino acid sequences among AlyVG1, AlyVG2, and AlyVG3 revealed low homologies. The identity value between AlyVG1 and AlyVG2 was 18.7%, and that between AlyVG2 and AlyVG3 was 17.0%. A higher identity value (26.0%) was observed between AlyVG1 and AlyVG3. Sequence comparison among known polyguluronate lyases including AlyVG1, AlyVG2, and AlyVG3 also did not reveal an identical region in these sequences. However, AlyVG1 showed the highest identity value (36.2%) and the highest similarity (73.3%) to AlyA from Klebsiella pneumoniae. A consensus region comprising nine amino acid (YFKAGXYXQ) in the carboxy-terminal region previously reported by Mallisard and colleagues was observed only in AlyVG1 and AlyVG2.

  2. Silver-Catalyzed Aldehyde Olefination Using Siloxy Alkynes.

    Science.gov (United States)

    Sun, Jianwei; Keller, Valerie A; Meyer, S Todd; Kozmin, Sergey A

    2010-03-20

    We describe the development of a silver-catalyzed carbonyl olefination employing electron rich siloxy alkynes. This process constitutes an efficient synthesis of trisubstituted unsaturated esters, and represents an alternative to the widely utilized Horner-Wadsworth-Emmons reaction. Excellent diastereoselectivities are observed for a range of aldehydes using either 1-siloxy-1-propyne or 1-siloxy-1-hexyne. This mild catalytic process also enables chemoselective olefination of aldehydes in the presence of either ester or ketone functionality. Furthermore, since no by-products are generated, this catalytic process is perfectly suited for development of sequential reactions that can be carried out in a single flask.

  3. Detoxification of aldehydes by histidine-containing dipeptides: from chemistry to clinical implications

    OpenAIRE

    Xie, Zhengzhi; Baba, Shahid P.; Sweeney, Brooke R.; Barski, Oleg A.

    2013-01-01

    Aldehydes are generated by oxidized lipids and carbohydrates at increased levels under conditions of metabolic imbalance and oxidative stress during atherosclerosis, myocardial and cerebral ischemia, diabetes, neurodegenerative diseases and trauma. In most tissues, aldehydes are detoxified by oxidoreductases that catalyze the oxidation or the reduction of aldehydes or enzymatic and nonenzymatic conjugation with low molecular weight thiols and amines, such as glutathione and histidine dipeptid...

  4. A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice

    KAUST Repository

    La, Honggui; Ding, Bo; Mishra, Gyan Prakash; Zhou, Bo; Yang, Hongmei; Bellizzi, Maria Del Rosario; Chen, Songbiao; Meyers, Blake C.; Peng, Zhaohua; Zhu, Jian-Kang; Wang, Guoliang

    2011-01-01

    DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counter-act transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.

  5. A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice

    KAUST Repository

    La, Honggui

    2011-09-06

    DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counter-act transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.

  6. Engineering methylaspartate ammonia lyase for the asymmetric synthesis of unnatural amino acids

    NARCIS (Netherlands)

    Raj, Hans; Szymanski, Wiktor; de Villiers, Jandre; Rozeboom, Henriëtte J.; Puthan Veetil, Vinod; Reis, Carlos R.; Villiers, Marianne de; Dekker, Frank J.; Wildeman, Stefaan de; Quax, Wim J.; Thunnissen, Andy-Mark W.H.; Feringa, Ben L.; Janssen, Dick B.; Poelarends, Gerrit J.

    The redesign of enzymes to produce catalysts for a predefined transformation remains a major challenge in protein engineering. Here, we describe the structure-based engineering of methylaspartate ammonia lyase (which in nature catalyses the conversion of 3-methylaspartate to ammonia and

  7. Purification and Characterization of a Unique Pectin Lyase from Aspergillus giganteus Able to Release Unsaturated Monogalacturonate during Pectin Degradation

    Directory of Open Access Journals (Sweden)

    Danielle Biscaro Pedrolli

    2014-01-01

    Full Text Available A pectin lyase, named PLIII, was purified to homogeneity from the culture filtrate of Aspergillus giganteus grown in submerged culture containing orange peel waste as carbon source. PLIII was able to digest apple pectin and citrus pectins with different degrees of methyl esterification. Interestingly, the PLIII activity was stimulated in the presence of some divalent cations including Pb2+ and was not significantly affected by Hg2+. Like other pectin lyases, PLIII is stimulated by but is not dependent on Ca2+. The main soluble product released during the degradation of pectic substances promoted by the PLIII is compatible with an unsaturated monogalacturonate. PLIII is a unique enzyme able to release unsaturated monogalacturonate as the only soluble product during the degradation of pectic substances; therefore, PLIII was classified as an exo-pectin lyase. To our knowledge, this is the first characterization of an exo-pectin lyase. The PLIII described in this work is potentially useful for ethanol production from pectin-rich biomass, besides other common applications for alkaline pectinases like preparation of textile fibers, coffee and tea fermentation, vegetable oil extraction, and the treatment of pulp in papermaking.

  8. [Pollution Characteristics of Aldehydes and Ketones Compounds in the Exhaust of Beijing Typical Restaurants].

    Science.gov (United States)

    Cheng, Jing-chen; Cui, Tong; He, Wan-qing; Nie, Lei; Wang, Jun-ling; Pan, Tao

    2015-08-01

    Aldehydes and ketones compounds, as one of the components in the exhaust of restaurants, are a class of volatile organic compounds (VOCs) with strong chemical reactivity. However, there is no systematic study on aldehydes and ketones compounds in the exhaust of restaurants. To further clarify the food source emission levels of aldehydes and ketones compounds and controlling measures, to access city group catering VOCs emissions control decision-making basis, this study selected 8 Beijing restaurants with different types. The aldehydes and ketones compounds were sampled using DNPH-silica tube, and then ultra performance liquid chromatography was used for quantitative measurement. The aldehydes and ketones concentrations of reference volume condition from 8 restaurants in descending order were Roasted Duck restaurant, Chinese Style Barbecue, Home Dishes, Western Fast-food, School Canteen, Chinese Style Fast-food, Sichuan Cuisine, Huaiyang Cuisine. The results showed that the range of aldehydes and ketones compounds (C1-C9) concentrations of reference volume condition in the exhaust of restaurants was 115.47-1035.99 microg x m(-3). The composition of aldehydes and ketones compounds in the exhaust of sampled restaurants was obviously different. The percentages of C1-C3 were above 40% in the exhaust from Chinese style restaurants. Fast food might emit more C4-C9 aldehydes and ketones compounds. From the current situation of existing aldehydes and ketones compounds control, the removal efficiency of high voltage electrostatic purifiers widely used in Beijing is limited.

  9. Genetic and molecular analyses of Escherichia coli N-acetylneuraminate lyase gene.

    OpenAIRE

    Kawakami, B; Kudo, T; Narahashi, Y; Horikoshi, K

    1986-01-01

    Two plasmids containing the N-acetylneuraminate lyase (NALase) gene (nanA) of Escherichia coli, pNL1 and pNL4, were constructed. Immunoprecipitation analysis indicated that the 35,000-dalton protein encoded in pNL4 was NALase. The synthesis of NALase in E. coli carrying these plasmids was constitutive.

  10. Mechanism of Cytochrome P450 17A1-Catalyzed Hydroxylase and Lyase Reactions

    DEFF Research Database (Denmark)

    Bonomo, Silvia; Jorgensen, Flemming Steen; Olsen, Lars

    2017-01-01

    Cytochrome P450 17A1 (CYP17A1) catalyzes C17 hydroxylation of pregnenolone and progesterone and the subsequent C17–C20 bond cleavage (lyase reaction) to form androgen precursors. Compound I (Cpd I) and peroxo anion (POA) are the heme-reactive species underlying the two reactions. We have characte...... the concept that the selectivity of the steroidogenic CYPs is ruled by direct interactions with the enzyme, in contrast to the selectivity of drug-metabolizing CYPs, where the reactivity of the substrates dominates....... characterized the reaction path for both the hydroxylase and lyase reactions using density functional theory (DFT) calculations and the enzyme–substrate interactions by molecular dynamics (MD) simulations. Activation barriers for positions subject to hydroxylase reaction have values close to each other and span...

  11. Activation of the jasmonic acid pathway by depletion of the hydroperoxide lyase OsHPL3 reveals crosstalk between the HPL and AOS branches of the oxylipin pathway in rice.

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Liu

    Full Text Available The allene oxide synthase (AOS and hydroperoxide lyase (HPL branches of the oxylipin pathway, which underlie the production of jasmonates and aldehydes, respectively, function in plant responses to a range of stresses. Regulatory crosstalk has been proposed to exist between these two signaling branches; however, there is no direct evidence of this. Here, we identified and characterized a jasmonic acid (JA overproduction mutant, cea62, by screening a rice T-DNA insertion mutant library for lineages that constitutively express the AOS gene. Map-based cloning was used to identify the underlying gene as hydroperoxide lyase OsHPL3. HPL3 expression and the enzyme activity of its product, (E-2-hexenal, were depleted in the cea62 mutant, which resulted in the dramatic overproduction of JA, the activation of JA signaling, and the emergence of the lesion mimic phenotype. A time-course analysis of lesion formation and of the induction of defense responsive genes in the cea62 mutant revealed that the activation of JA biosynthesis and signaling in cea62 was regulated in a developmental manner, as was OsHPL3 activity in the wild-type plant. Microarray analysis showed that the JA-governed defense response was greatly activated in cea62 and this plant exhibited enhanced resistance to the T1 strain of the bacterial blight pathogen Xanthomonasoryzaepvoryzae (Xoo. The wounding response was attenuated in cea62 plants during the early stages of development, but partially recovered when JA levels were elevated during the later stages. In contrast, the wounding response was not altered during the different developmental stages of wild-type plants. These findings suggest that these two branches of the oxylipin pathway exhibit crosstalk with regards to biosynthesis and signaling and cooperate with each other to function in diverse stress responses.

  12. Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine.

    Science.gov (United States)

    Pinto, John T; Krasnikov, Boris F; Alcutt, Steven; Jones, Melanie E; Dorai, Thambi; Villar, Maria T; Artigues, Antonio; Li, Jianyong; Cooper, Arthur J L

    2014-11-07

    Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Grapevine fatty acid hydroperoxide lyase generates actin-disrupting volatiles and promotes defence-related cell death

    Science.gov (United States)

    Wang, Hao; Claudel, Patricia; Riemann, Michael; Hause, Bettina; Hugueney, Philippe; Nick, Peter

    2018-01-01

    Abstract Fatty acid hydroperoxides can generate short-chained volatile aldehydes that may participate in plant defence. A grapevine hydroperoxide lyase (VvHPL1) clustering to the CYP74B class was functionally characterized with respect to a role in defence. In grapevine leaves, transcripts of this gene accumulated rapidly to high abundance in response to wounding. Cellular functions of VvHPL1 were investigated upon heterologous expression in tobacco BY-2 cells. A C-terminal green fluorescent protein (GFP) fusion of VvHPL1 was located in plastids. The overexpression lines were found to respond to salinity stress or the bacterial elicitor harpin by increasing cell death. This signal-dependent mortality response was mitigated either by addition of exogenous jasmonic acid or by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases. By feeding different substrates to recombinantly expressed enzyme, VvHPL1 could also be functionally classified as true 13-HPL. The cognate products generated by this 13-HPL were cis-3-hexenal and trans-2-hexenal. Using a GFP-tagged actin marker line, one of these isomeric products, cis-3-hexenal, was found specifically to elicit a rapid disintegration of actin filaments. This response was not only observed in the heterologous system (tobacco BY-2), but also in a grapevine cell strain expressing this marker, as well as in leaf discs from an actin marker grape used as a homologous system. These results are discussed in the context of a role for VvHPL1 in a lipoxygenase-dependent signalling pathway triggering cell death-related defence that bifurcates from jasmonate-dependent basal immunity. PMID:29659985

  14. Aldehyde-sequestering drugs: tools for studying protein damage by lipid peroxidation products.

    Science.gov (United States)

    Burcham, Philip C; Kaminskas, Lisa M; Fontaine, Frank R; Petersen, Dennis R; Pyke, Simon M

    2002-12-27

    Elevated levels of reactive alpha,beta-unsaturated aldehydes (e.g. malondialdehyde, 4-hydroxynonenal and acrolein) in the affected tissues of various degenerative conditions suggest these substances are active propagators of the disease process. One experimental approach to attenuating damage by these intermediates employs 'aldehyde-sequestering drugs' as sacrificial nucleophiles, thereby sparing cell macromolecules and perhaps slowing disease progression. Drugs with demonstrated trapping activity toward lipid-derived aldehydes include various amine compounds such as aminoguanidine, carnosine and pyridoxamine. We have focused on identifying scavengers of acrolein, perhaps the most toxic aldehyde formed during lipid peroxidation cascades. Various phthalazine compounds (hydralazine and dihydralazine) were found to trap acrolein readily, forming hydrazone derivatives in a rapid Schiff-type reaction. These compounds strongly protect against acrolein-mediated toxicity in isolated hepatocytes.

  15. Aldehyde Dehydrogenases in Arabidopsis thaliana: Biochemical Requirements, Metabolic Pathways, and Functional Analysis.

    Science.gov (United States)

    Stiti, Naim; Missihoun, Tagnon D; Kotchoni, Simeon O; Kirch, Hans-Hubert; Bartels, Dorothea

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) are a family of enzymes which catalyze the oxidation of reactive aldehydes to their corresponding carboxylic acids. Here we summarize molecular genetic and biochemical analyses of selected ArabidopsisALDH genes. Aldehyde molecules are very reactive and are involved in many metabolic processes but when they accumulate in excess they become toxic. Thus activity of aldehyde dehydrogenases is important in regulating the homeostasis of aldehydes. Overexpression of some ALDH genes demonstrated an improved abiotic stress tolerance. Despite the fact that several reports are available describing a role for specific ALDHs, their precise physiological roles are often still unclear. Therefore a number of genetic and biochemical tools have been generated to address the function with an emphasis on stress-related ALDHs. ALDHs exert their functions in different cellular compartments and often in a developmental and tissue specific manner. To investigate substrate specificity, catalytic efficiencies have been determined using a range of substrates varying in carbon chain length and degree of carbon oxidation. Mutational approaches identified amino acid residues critical for coenzyme usage and enzyme activities.

  16. Threshold responses in cinnamic-aldehyde-sensitive subjects: results and methodological aspects

    DEFF Research Database (Denmark)

    Johansen, J D; Andersen, Klaus Ejner; Rastogi, S C

    1996-01-01

    Cinnamic aldehyde is an important fragrance material and contact allergen. The present study was performed to provide quantitative data on the eliciting capacity of cinnamic aldehyde, to be considered in assessment of clinical relevance and health hazard. The skin response to serial dilution patch...

  17. Do flavouring compounds contribute to aldehyde emissions in e-cigarettes?

    Science.gov (United States)

    Farsalinos, Konstantinos E; Voudris, Vassilis

    2018-05-01

    A recent study identified up to 10,000-fold higher aldehyde emissions from flavoured compared to unflavoured e-cigarette liquids. We set to replicate this study and also test similar flavourings with a new-generation e-cigarette device. Three liquids with the highest levels of aldehyde emissions in the previous study were tested (in standard and sweetened versions) using the same e-cigarette device and puffing patterns. Additionally, similar flavourings from a different manufacturer were tested using a new-generation e-cigarette device. Unflavoured samples were also tested. Low levels of formaldehyde (8.3-62 μg/g), acetaldehyde (12.1-26.0 μg/g) and acrolein (5.4-19.4 μg/g) were detected, lower by up to 589-fold compared to the previous report. Unflavoured liquid emitted 16.1 μg/g formaldehyde, 5.6 μg/g acetaldehyde and 2.4 μg/g acrolein, significantly lower compared to 2 liquids for formaldehyde and 1 for acrolein. Emissions from the new-generation device were even lower. Aldehyde emissions from all flavoured liquids were 79-99.8% lower than smoking and lower than commonly measured indoor levels and occupational and indoor safety limits. The e-cigarettes tested herein emit very low levels of aldehydes. Some flavourings may contribute to aldehyde emissions, but the absolute levels were minimal. Validated methods should be used when analysing e-cigarette emissions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Contribution of ozone to airborne aldehyde formation in Paris homes.

    Science.gov (United States)

    Rancière, Fanny; Dassonville, Claire; Roda, Célina; Laurent, Anne-Marie; Le Moullec, Yvon; Momas, Isabelle

    2011-09-15

    Indoor aldehydes may result from ozone-initiated chemistry, mainly documented by experimental studies. As part of an environmental investigation included in the PARIS birth cohort, the aim of this study was to examine ozone contribution to airborne aldehyde formation in Paris homes. Formaldehyde, acetaldehyde and hexaldehyde levels, as well as styrene, nitrogen dioxide and nicotine concentrations, comfort parameters and carbon dioxide levels, were measured twice during the first year of life of the babies. Ambient ozone concentrations were collected from the closest background station of the regional air monitoring network. Traffic-related nitrogen oxide concentrations in front of the dwellings were estimated by an air pollution dispersion model. Home characteristics and families' way of life were described by questionnaires. Stepwise multiple linear regression models were used to link aldehyde levels with ambient ozone concentrations and a few aldehyde precursors involved in oxidation reactions, adjusting for other indoor aldehyde sources, comfort parameters and traffic-related nitrogen oxides. A 4 and 11% increase in formaldehyde and hexaldehyde levels was pointed out when 8-hour ozone concentrations increased by 20 μg/m(3). The influence of potential precursors such as indoor styrene level and frequent use of air fresheners, containing unsaturated volatile organic compounds as terpenes, was also found. Thus, our results suggest that ambient ozone can significantly impact indoor air quality, especially with regard to formaldehyde and hexaldehyde levels. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. AlgM4: A New Salt-Activated Alginate Lyase of the PL7 Family with Endolytic Activity

    Directory of Open Access Journals (Sweden)

    Guiyuan Huang

    2018-04-01

    Full Text Available Alginate lyases are a group of enzymes that catalyze the depolymerization of alginates into oligosaccharides or monosaccharides. These enzymes have been widely used for a variety of purposes, such as producing bioactive oligosaccharides, controlling the rheological properties of polysaccharides, and performing structural analyses of polysaccharides. The algM4 gene of the marine bacterium Vibrio weizhoudaoensis M0101 encodes an alginate lyase that belongs to the polysaccharide lyase family 7 (PL7. In this study, the kinetic constants Vmax (maximum reaction rate and Km (Michaelis constant of AlgM4 activity were determined as 2.75 nmol/s and 2.72 mg/mL, respectively. The optimum temperature for AlgM4 activity was 30 °C, and at 70 °C, AlgM4 activity dropped to 11% of the maximum observed activity. The optimum pH for AlgM4 activity was 8.5, and AlgM4 was completely inactive at pH 11. The addition of 1 mol/L NaCl resulted in a more than sevenfold increase in the relative activity of AlgM4. The secondary structure of AlgM4 was altered in the presence of NaCl, which caused the α-helical content to decrease from 12.4 to 10.8% and the β-sheet content to decrease by 1.7%. In addition, NaCl enhanced the thermal stability of AlgM4 and increased the midpoint of thermal denaturation (Tm by 4.9 °C. AlgM4 exhibited an ability to degrade sodium alginate, poly-mannuronic acid (polyM, and poly-guluronic acid (polyG, resulting in the production of oligosaccharides with a degree of polymerization (DP of 2–9. AlgM4 possessed broader substrate, indicating that it is a bifunctional alginate lyase. Thus, AlgM4 is a novel salt-activated and bifunctional alginate lyase of the PL7 family with endolytic activity.

  20. Studying fatty aldehyde metabolism in living cells with pyrene-labeled compounds

    NARCIS (Netherlands)

    Keller, Markus A.; Watschinger, Katrin; Lange, Karsten; Golderer, Georg; Werner-Felmayer, Gabriele; Hermetter, Albin; Wanders, Ronald J. A.; Werner, Ernst R.

    2012-01-01

    The lack of fatty aldehyde dehydrogenase function in Sjogren Larsson Syndrome (SLS) patient cells not only impairs the conversion of fatty aldehydes into their corresponding fatty acid but also has an effect on connected pathways. Alteration of the lipid profile in these cells is thought to be

  1. Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.

    Directory of Open Access Journals (Sweden)

    Young-Moo Choo

    Full Text Available Antennae-specific odorant-degrading enzymes (ODEs are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs. Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW, Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.

  2. Characterization of two bacterial hydroxynitrile lyases with high similarity to cupin superfamily proteins

    NARCIS (Netherlands)

    Hussain, Z.; Wiedner, R.; Steiner, K.; Hajek, T.; Avi, M.; Hecher, B.; Sessitsch, A.; Schwab, H.

    2012-01-01

    Hydroxynitrile lyases (HNLs) catalyze the cleavage of cyanohydrins. In the reverse reaction, they catalyze the formation of carbon-carbon bonds by enantioselective condensation of hydrocyanic acid with carbonyls. In this study, we describe two proteins from endophytic bacteria that display activity

  3. Toxicity of polyunsaturated aldehydes of diatoms to Indo-Pacific bioindicator organism Echinometra mathaei.

    Science.gov (United States)

    Sartori, Davide; Gaion, Andrea

    2016-01-01

    Although it is well known suitability of early developmental stages of sea urchin as recommended model for pollutant toxicity testing, little is known about the sensitivity of Indo-Pacific species Echinometra mathaei to polyunsaturated aldehydes. In this study, the effect of three short chain aldehydes, 2,4-decadienal (DD), 2,4-octadienal (OD) and 2,4-heptadienal (HD), normally found in many diatoms, such as Skeletonema costatum, Skeletonema marinoi and Thalassiosira rotula, was evaluated on larval development of E. mathaei embryos. Aldehydes affected larval development in a dose-dependent manner, in particular HD>OD>DD; the results of this study highlighted the higher sensitivity of this species toward aldehydes compared with data registered for other sea urchin species. In comparison with studies reported in the literature, contrasting results were observed during our tests; therefore, an increasing toxic effect was registered with decreasing the chain length of aldehydes. This work could provide new insights in the development of new toxicological assays toward most sensitive species.

  4. Effect of whey protein on the In Vivo Release of Aldehydes.

    NARCIS (Netherlands)

    Weel, K.G.C.; Boelrijk, A.E.M.; Burger, J.J.; Claassen, N.E.; Gruppen, H.; Voragen, A.G.J.

    2003-01-01

    Retention of aldehydes by whey proteins in solutions buffered at a range of pH values was studied under static and dynamic headspace conditions and in vivo in exhaled air. Static headspace measurements showed a clear increase in retention in the presence of whey proteins for aldehydes with longer

  5. Effect of selected aldehydes on the growth and fermentation of ethanologenic Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Zaldivar, J.; Ingram, L.O. [Univ. of Florida, Gainesville (United States). Dept. of Microbiology and Cell Science; Martinez, A. [Univ. of Florida, Gainesville (United States). Dept. of Microbiology and Cell Science]|[Univ. Nacional Autonoma de Mexico (Mexico). Inst. de Biotecnologia

    1999-10-05

    Bioethanol production from lignocellulosic raw-materials requires the hydrolysis of carbohydrate polymers into a fermentable syrup. During the hydrolysis of hemicellulose with dilute acid, a variety of toxic compounds are produced such as soluble aromatic aldehydes from lignin and furfural from pentose destruction. In this study, the authors have investigated the toxicity of representative aldehydes (furfural, 5-hydroxymethlyfurfural, 4-hydroxybenzaldehyde, syringaldehyde, and vanillin) as inhibitors of growth and ethanol production by ethanologenic derivatives of Escherichia coli B (strains K011 and LY01). Aromatic aldyhydes were at least twice as toxic as furfural of 5-hydroxymethylfurfural on a weight basis. The toxicities of all aldehydes (and ethanol) except furfural were additive when tested in binary combinations. In all cases, combinations with furfural were unexpectedly toxic. Although the potency of these aldehydes was directly related to hydrophobicity indicating a hydrophobic site of action, none caused sufficient membrane damage to allow the leakage of intracellular magnesium even when present at sixfold the concentrations required for growth inhibition. Of the aldehydes tested, only furfural strongly inhibited ethanol production in vitro. A comparison with published results for other microorganisms indicates that LY01 is equivalent or more resistant than other biocatalysts to the aldehydes examined in this study.

  6. Role of Lipid Peroxidation-Derived α, β-Unsaturated Aldehydes in Vascular Dysfunction

    Directory of Open Access Journals (Sweden)

    Seung Eun Lee

    2013-01-01

    Full Text Available Vascular diseases are the most prominent cause of death, and inflammation and vascular dysfunction are key initiators of the pathophysiology of vascular disease. Lipid peroxidation products, such as acrolein and other α, β-unsaturated aldehydes, have been implicated as mediators of inflammation and vascular dysfunction. α, β-Unsaturated aldehydes are toxic because of their high reactivity with nucleophiles and their ability to form protein and DNA adducts without prior metabolic activation. This strong reactivity leads to electrophilic stress that disrupts normal cellular function. Furthermore, α, β-unsaturated aldehydes are reported to cause endothelial dysfunction by induction of oxidative stress, redox-sensitive mechanisms, and inflammatory changes such as induction of cyclooxygenase-2 and cytokines. This review provides an overview of the effects of lipid peroxidation products, α, β-unsaturated aldehydes, on inflammation and vascular dysfunction.

  7. Biocatalytic Enantioselective Synthesis of N-Substituted Aspartic Acids by Aspartate Ammonia Lyase

    NARCIS (Netherlands)

    Weiner, Barbara; Poelarends, Gerrit J.; Janssen, Dick B.; Feringa, Ben L.

    2008-01-01

    The gene encoding aspartate ammonia lyase (aspB) from Bacillus sp. YM55-1 has been cloned and overexpressed, and the recombinant enzyme containing a C-terminal His6 tag has been purified to homogeneity and subjected to kinetic characterization. Kinetic studies have shown that the His6 tag does not

  8. Maternal Aldehyde Elimination during Pregnancy Preserves the Fetal Genome

    Science.gov (United States)

    Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P.; Patel, Ketan J.

    2014-01-01

    Summary Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2−/−Fanca−/− embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. PMID:25155611

  9. Maternal aldehyde elimination during pregnancy preserves the fetal genome.

    Science.gov (United States)

    Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P; Patel, Ketan J

    2014-09-18

    Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2(-/-)Fanca(-/-) embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  10. The replicative DNA polymerase of herpes simplex virus 1 exhibits apurinic/apyrimidinic and 5′-deoxyribose phosphate lyase activities

    Science.gov (United States)

    Bogani, Federica; Boehmer, Paul E.

    2008-01-01

    Base excision repair (BER) is essential for maintaining genome stability both to counter the accumulation of unusual bases and to protect from base loss in the DNA. Herpes simplex virus 1 (HSV-1) is a large dsDNA virus that encodes its own DNA replication machinery, including enzymes involved in nucleotide metabolism. We report on a replicative family B and a herpesvirus-encoded DNA Pol that possesses DNA lyase activity. We have discovered that the catalytic subunit of the HSV-1 DNA polymerase (Pol) (UL30) exhibits apurinic/apyrimidinic (AP) and 5′-deoxyribose phosphate (dRP) lyase activities. These activities are integral to BER and lead to DNA cleavage on the 3′ side of abasic sites and 5′-dRP residues that remain after cleavage by 5′-AP endonuclease. The UL30-catalyzed reaction occurs independently of divalent cation and proceeds via a Schiff base intermediate, indicating that it occurs via a lyase mechanism. Partial proteolysis of the Schiff base shows that the DNA lyase activity resides in the Pol domain of UL30. These observations together with the presence of a virus-encoded uracil DNA glycosylase indicates that HSV-1 has the capacity to perform critical steps in BER. These findings have implications on the role of BER in viral genome maintenance during lytic replication and reactivation from latency. PMID:18695225

  11. Ni-Catalyzed Dehydrogenative Cross-Coupling: Direct Transformation of Aldehydes to Esters and Amides

    Science.gov (United States)

    Whittaker, Aaron M.; Dong, Vy M.

    2015-01-01

    By exploring a new mode of Ni-catalyzed cross-coupling, we have developed a protocol to transform both aromatic and aliphatic aldehydes into either esters or amides directly. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. We present mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C–H bond. PMID:25424967

  12. Chronic oral exposure to the aldehyde pollutant acrolein induces dilated cardiomyopathy

    Science.gov (United States)

    Ismahil, Mohamed Ameen; Hamid, Tariq; Haberzettl, Petra; Gu, Yan; Chandrasekar, Bysani; Srivastava, Sanjay; Bhatnagar, Aruni

    2011-01-01

    Environmental triggers of dilated cardiomyopathy are poorly understood. Acute exposure to acrolein, a ubiquitous aldehyde pollutant, impairs cardiac function and cardioprotective responses in mice. Here, we tested the hypothesis that chronic oral exposure to acrolein induces inflammation and cardiomyopathy. C57BL/6 mice were gavage-fed acrolein (1 mg/kg) or water (vehicle) daily for 48 days. The dose was chosen based on estimates of human daily unsaturated aldehyde consumption. Compared with vehicle-fed mice, acrolein-fed mice exhibited significant (P acrolein adduct formation indicative of physical translocation of ingested acrolein to the heart. Acrolein also induced myocyte hypertrophy (∼2.2-fold increased myocyte area, P acrolein-exposed hearts, along with upregulated gene expression of proinflammatory cytokines tumor necrosis factor-α and interleukin-1β. Long-term oral exposure to acrolein, at an amount within the range of human unsaturated aldehyde intake, induces a phenotype of dilated cardiomyopathy in the mouse. Human exposure to acrolein may have analogous effects and raise consideration of an environmental, aldehyde-mediated basis for heart failure. PMID:21908791

  13. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency.

    Science.gov (United States)

    Stuy, M; Chen, G-F; Masonek, J M; Scharschmidt, B F

    2015-09-01

    A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS) and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB). The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet.

  14. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency☆

    Science.gov (United States)

    Stuy, M.; Chen, G.-F.; Masonek, J.M.; Scharschmidt, B.F.

    2015-01-01

    A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS) and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB). The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet. PMID:26937403

  15. Indoor aldehydes: measurement of contamination levels and identification of their determinants in Paris dwellings

    International Nuclear Information System (INIS)

    Clarisse, B.; Laurent, A.M.; Seta, N.; Le Moullec, Y.; El Hasnaoui, A.; Momas, I.

    2003-01-01

    The recent increased prevalence of childhood asthma and atopy has brought into question the impact of outdoor pollutants and indoor air quality. The contributory role of aldehydes to this problem and the fact that they are mainly derived from the domestic environment make them of particular interest. This study therefore measures six different aldehyde levels in Paris dwellings from potentially different sources and identifies their indoor determinants. The study was carried out in the three principal rooms of 61 flats with no previous history of complaint for olfactory nuisance or specific symptoms, two-thirds of the flats having been recently refurbished. Aldehydes were sampled in these rooms using passive samplers, and a questionnaire on potential aldehyde sources was filled out at the same time. A multiple linear regression model was used to investigate indoor aldehyde determinants. Our study revealed that propionaldehyde and benzaldehyde were of minor importance compared to formaldehyde, acetaldehyde, pentanal, and hexanal. We found that levels of these last four compounds depended on the age of wall or floor coverings (renovations less than 1 year old), smoking, and ambient parameters (carbon dioxide levels, temperature). These results could help in the assessment of indoor aldehyde emissions

  16. Effects of cooking method, cooking oil, and food type on aldehyde emissions in cooking oil fumes.

    Science.gov (United States)

    Peng, Chiung-Yu; Lan, Cheng-Hang; Lin, Pei-Chen; Kuo, Yi-Chun

    2017-02-15

    Cooking oil fumes (COFs) contain a mixture of chemicals. Of all chemicals, aldehydes draw a great attention since several of them are considered carcinogenic and formation of long-chain aldehydes is related to fatty acids in cooking oils. The objectives of this research were to compare aldehyde compositions and concentrations in COFs produced by different cooking oils, cooking methods, and food types and to suggest better cooking practices. This study compared aldehydes in COFs produced using four cooking oils (palm oil, rapeseed oil, sunflower oil, and soybean oil), three cooking methods (stir frying, pan frying, and deep frying), and two foods (potato and pork loin) in a typical kitchen. Results showed the highest total aldehyde emissions in cooking methods were produced by deep frying, followed by pan frying then by stir frying. Sunflower oil had the highest emissions of total aldehydes, regardless of cooking method and food type whereas rapeseed oil and palm oil had relatively lower emissions. This study suggests that using gentle cooking methods (e.g., stir frying) and using oils low in unsaturated fatty acids (e.g., palm oil or rapeseed oil) can reduce the production of aldehydes in COFs, especially long-chain aldehydes such as hexanal and t,t-2,4-DDE. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. INTERACTION OF ALDEHYDES DERIVED FROM LIPID PEROXIDATION AND MEMBRANE PROTEINS.

    Directory of Open Access Journals (Sweden)

    Stefania ePizzimenti

    2013-09-01

    Full Text Available A great variety of compounds are formed during lipid peroxidation of polyunsaturated fatty acids of membrane phospholipids. Among them, bioactive aldehydes, such as 4-hydroxyalkenals, malondialdehyde (MDA and acrolein, have received particular attention since they have been considered as toxic messengers that can propagate and amplify oxidative injury. In the 4-hydroxyalkenal class, 4-hydroxy-2-nonenal (HNE is the most intensively studied aldehyde, in relation not only to its toxic function, but also to its physiological role. Indeed, HNE can be found at low concentrations in human tissues and plasma and participates in the control of biological processes, such as signal transduction, cell proliferation and differentiation. Moreover, at low doses, HNE exerts an anti-cancer effect, by inhibiting cell proliferation, angiogenesis, cell adhesion and by inducing differentiation and/or apoptosis in various tumor cell lines. It is very likely that a substantial fraction of the effects observed in cellular responses, induced by HNE and related aldehydes, be mediated by their interaction with proteins, resulting in the formation of covalent adducts or in the modulation of their expression and/or activity. In this review we focus on membrane proteins affected by lipid peroxidation-derived aldehydes, under physiological and pathological conditions.

  18. Methyltrioxorhenium as catalyst of a novel aldehyde olefination

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, W.A. (Technische Univ. Muenchen, Garching (Germany). Anorganisch-Chemisches Inst.); Wang Mei (Academia Sinica, Dalian Inst. of Chemical Physics (China))

    1991-12-01

    From aldehydes or cyclic ketones, diazoalkanes, and teritiary phosphanes, olefins may be prepared with MTO as catalyst. In particular, diazoacetates and -malonates (R{sup 2}, R{sup 3} = H, CO{sub 2}Et, or 2 x CO{sub 2}Me) can be transformed into olefins with aliphatic and aromatic aldehydes (R{sup 1} = iPr, trans-PhCH=CH, Ph, 4-NO{sub 2}C{sub 6}H{sub 4}, etc.). Readily accessible starting materials, easy handling, mild reaction conditions, and good yields characterize the new synthesis method. (R' = Ph, 3-C{sub 6}H{sub 4}SO{sub 3}Na, nBu.) (orig.).

  19. Targeting sphingosine-1-phosphate lyase as an anabolic therapy for bone loss.

    Science.gov (United States)

    Weske, Sarah; Vaidya, Mithila; Reese, Alina; von Wnuck Lipinski, Karin; Keul, Petra; Bayer, Julia K; Fischer, Jens W; Flögel, Ulrich; Nelsen, Jens; Epple, Matthias; Scatena, Marta; Schwedhelm, Edzard; Dörr, Marcus; Völzke, Henry; Moritz, Eileen; Hannemann, Anke; Rauch, Bernhard H; Gräler, Markus H; Heusch, Gerd; Levkau, Bodo

    2018-05-01

    Sphingosine-1-phosphate (S1P) signaling influences bone metabolism, but its therapeutic potential in bone disorders has remained unexplored. We show that raising S1P levels in adult mice through conditionally deleting or pharmacologically inhibiting S1P lyase, the sole enzyme responsible for irreversibly degrading S1P, markedly increased bone formation, mass and strength and substantially decreased white adipose tissue. S1P signaling through S1P 2 potently stimulated osteoblastogenesis at the expense of adipogenesis by inversely regulating osterix and PPAR-γ, and it simultaneously inhibited osteoclastogenesis by inducing osteoprotegerin through newly discovered p38-GSK3β-β-catenin and WNT5A-LRP5 pathways. Accordingly, S1P 2 -deficient mice were osteopenic and obese. In ovariectomy-induced osteopenia, S1P lyase inhibition was as effective as intermittent parathyroid hormone (iPTH) treatment in increasing bone mass and was superior to iPTH in enhancing bone strength. Furthermore, lyase inhibition in mice successfully corrected severe genetic osteoporosis caused by osteoprotegerin deficiency. Human data from 4,091 participants of the SHIP-Trend population-based study revealed a positive association between serum levels of S1P and bone formation markers, but not resorption markers. Furthermore, serum S1P levels were positively associated with serum calcium , negatively with PTH , and curvilinearly with body mass index. Bone stiffness, as determined through quantitative ultrasound, was inversely related to levels of both S1P and the bone formation marker PINP, suggesting that S1P stimulates osteoanabolic activity to counteract decreasing bone quality. S1P-based drugs should be considered as a promising therapeutic avenue for the treatment of osteoporotic diseases.

  20. Research advances in the catalysts for the selective oxidation of ethane to aldehydes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; ZHAO Zhen; XU Chunming

    2005-01-01

    Selective oxidation of ethane to aldehydes is one of the most difficult processes in the catalysis researches of low alkanes. The development of selective oxidation of ethane to aldehydes (formaldehyde, acetaldehyde and acrolein) is discussed. The latest progress of the catalysts, including bulk or supported metal oxide catalysts, highly dispersed and isolated active sites catalysts, and the photo-catalytic ethane oxidation catalysts, partial oxidation of ethane in the gas phase, and the proposed reaction pathways from ethane to aldehydes are involved.

  1. Oxidative Esterification of Aldehydes with Urea Hydrogen Peroxide Catalyzed by Aluminum Chloride Hexahydrate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sin-Ae; Kim, Yoon Mi; Lee, Jong Chan [Chung-Ang University, Seoul (Korea, Republic of)

    2016-08-15

    We have developed a new, environmentally benign and highly efficient oxidative preparation of methyl esters by the reaction of various aldehydes with UHP in methanol catalyzed by readily accessible aluminum(III) chloride hexahydrate. This new greener and cost effective direct esterification method can serve as a useful alternative to existing protocols. Esters are some of the most important functional groups in organic chemistry and have been found in the sub-structure of a variety of natural products, industrial chemicals, and pharmaceuticals. Numerous methods have been reported for the preparation of various esters. In particular, this method gives low yields for both aldehydes containing electron donating substituents in aromatic rings and heterocyclic aldehydes. Therefore, development of a more general, efficient, and greener protocol for the esterification of aldehydes with readily available catalyst is still desirable.

  2. On the nature of the olefination reaction involving ditungsten hexaalkoxides and aldehydes or ketones

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, M.H.; Huffman, J.C.; Lucas, E.A.; Sousa, A.; Streib, W.E. [Indiana Univ., Bloomington, IN (United States)

    1992-03-25

    Reductive coupling of aldehydes and ketones to olefins under the action of ditungsten hexaalkoxides was investigated. In these reactions, reductive cleavage of the aldehyde or ketone carbonyl is followed by formation of the olefinic C-C bond and breaking of the carbonyl C-O bond of the second aldehyde or ketone. Observations concerning the initial C-O bond cleavage and subsequent C-C bond formation are presented. 10 refs., 4 figs.

  3. High-Level Expression of a Thermally Stable Alginate Lyase Using Pichia pastoris, Characterization and Application in Producing Brown Alginate Oligosaccharide

    Directory of Open Access Journals (Sweden)

    Haifeng Li

    2018-05-01

    Full Text Available An alginate lyase encoding gene sagl from Flavobacterium sp. H63 was codon optimized and recombinantly expressed at high level in P.pastoris through high cell-density fermentation. The highest yield of recombinant enzyme of sagl (rSAGL in yeast culture supernatant reached 226.4 μg/mL (915.5 U/mL. This was the highest yield record of recombinant expression of alginate lyase so far. The rSAGL was confirmed as a partially glycosylated protein through EndoH digestion. The optimal reaction temperature and pH of this enzyme were 45 °C and 7.5; 80 mM K+ ions could improve the catalytic activity of the enzyme by 244% at most. rSAGL was a thermal stable enzyme with T5015 of 57–58 °C and T5030 of 53–54 °C. Its thermal stability was better than any known alginate lyase. In 100 mM phosphate buffer of pH 6.0, rSAGL could retain 98.8% of the initial activity after incubation at 50 °C for 2 h. Furthermore, it could retain 61.6% of the initial activity after 48 h. The specific activity of the purified rSAGL produced by P. pastoris attained 4044 U/mg protein, which was the second highest record of alginate lyase so far. When the crude enzyme of the rSAGL was directly used in transformation of sodium alginate with 40 g/L, 97.2% of the substrate was transformed to di, tri, tetra brown alginate oligosaccharide after 32 h of incubation at 50 °C, and the final concentration of reducing sugar in mixture reached 9.51 g/L. This is the first report of high-level expression of thermally stable alginate lyase using P. pastoris system.

  4. Understanding Which Residues of the Active Site and Loop Structure of a Tyrosine Aminomutase Define Its Mutase and Lyase Activities.

    Science.gov (United States)

    Attanayake, Gayanthi; Walter, Tyler; Walker, Kevin D

    2018-05-30

    Site-directed mutations and substrate analogues were used to gain insights into the branch-point reaction of the 3,5-dihydro-5-methylidene-4 H-imidazol-4-one (MIO)-tyrosine aminomutase from Oryza sativa ( OsTAM). Exchanging the active residues of OsTAM (Y125C/N446K) for those in a phenylalanine aminomutase TcPAM altered its substrate specificity from tyrosine to phenylalanine. The aminomutase mechanism of OsTAM surprisingly changed almost exclusively to that of an ammonia lyase making cinnamic acid (>95%) over β-phenylalanine [Walter, T., et al. (2016) Biochemistry 55, 3497-3503]. We hypothesized that the missing electronics or sterics on the aryl ring of the phenylalanine substrate, compared with the sizable electron-donating hydroxyl of the natural tyrosine substrate, influenced the unexpected lyase reactivity of the OsTAM mutant. The double mutant was incubated with 16 α-phenylalanine substituent analogues of varying electronic strengths and sterics. The mutant converted each analogue principally to its acrylate with ∼50% conversion of the p-Br substrate, making only a small amount of the β-amino acid. The inner loop structure over the entrance to the active site was also mutated to assess how the lyase and mutase activities are affected. An OsTAM loop mutant, matching the loop residues of TcPAM, still chiefly made >95% of the acrylate from each substrate. A combined active site:loop mutant was most reactive but remained a lyase, making 10-fold more acrylates than other mutants did. While mutations within the active site changed the substrate specificity of OsTAM, continued exploration is needed to fully understand the interplay among the inner loop, the substrate, and the active site in defining the mutase and lyase activities.

  5. Oxidative desulfurization of diesel with TBHP/isobutyl aldehyde/air oxidation system

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei; Wang, Chengyong; Lin, Peng; Lu, Xiaoping [Institute of Sonochemical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu (China)

    2011-01-15

    Oxidative desulfurization of hydrogenation diesel (40 mL) was studied using air as oxidant, tert-butyl hydroperoxide (TBHP) as radical initiator at ambient pressure and moderate temperature in the presence of isobutyl aldehyde. TBHP could accelerate the production of carbonyl radical and its peroxidation. When the molar fraction of TBHP was 5 mmol, the conversion of DBT could reach 96.1% in the present of 20 mmol isobutyl aldehyde and air, which was more than that of 85.5% without initiator. The air was an effective oxidant and acetonitrile was an optimal solvent in this process. The sulfur content of the hydrogenation diesel could be reduced from 403 to 13 ppm (96.8% removed) under the synergistic effect of air, TBHP and isobutyl aldehyde. (author)

  6. Refeeding syndrome in a young woman with argininosuccinate lyase deficiency

    Directory of Open Access Journals (Sweden)

    M. Stuy

    2015-09-01

    Full Text Available A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB. The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet.

  7. The use of tomato aminoaldehyde dehydrogenase 1 for the detection of aldehydes in fruit distillates.

    Science.gov (United States)

    Frömmel, Jan; Tarkowski, Petr; Kopečný, David; Šebela, Marek

    2016-09-25

    Plant NAD(+)-dependent aminoaldehyde dehydrogenases (AMADHs, EC 1.2.1.19) belong to the family 10 of aldehyde dehydrogenases. They participate in the metabolism of polyamines or osmoprotectants. The enzymes are characterized by their broad substrate specificity covering ω-aminoaldehydes, aliphatic and aromatic aldehydes as well as nitrogen-containing heterocyclic aldehydes. The isoenzyme 1 from tomato (Solanum lycopersicum; SlAMADH1) oxidizes aliphatic aldehydes very efficiently and converts also furfural, its derivatives or benzaldehyde, which are present at low concentrations in alcoholic distillates such as fruit brandy. In this work, SlAMADH1 was examined as a bioanalytical tool for their detection. These aldehydes arise from fermentation processes or thermal degradation of sugars and their presence is related to health complications after consumption including nausea, emesis, sweating, decrease in blood pressure, hangover headache, among others. Sixteen samples of slivovitz (plum brandy) from local producers in Moravia, Czech Republic, were analyzed for their aldehyde content using a spectrophotometric activity assay with SlAMADH1. In all cases, there were oxidative responses observed when monitoring NADH production in the enzymatic reaction. Aldehydes in the distillate samples were also subjected to a standard determination using reversed-phase HPLC with spectrophotometric and tandem mass spectrometric detection after a derivatization with 2,4-dinitrophenylhydrazine. Results obtained by both methods were found to correlate well for a majority of the analyzed samples. The possible applicability of SlAMADH1 for the evaluation of aldehyde content in food and beverages has now been demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Influences of cinnamic aldehydes on H⁺ extrusion activity and ultrastructure of Candida.

    Science.gov (United States)

    Shreaz, Sheikh; Bhatia, Rimple; Khan, Neelofar; Muralidhar, Sumathi; Manzoor, Nikhat; Khan, Luqman Ahmad

    2013-02-01

    The antifungal effects of cinnamaldehyde, 4-hydroxy-3-methoxycinnamaldehyde (coniferyl aldehyde) and 3,5-dimethoxy-4-hydroxycinnamaldehyde (sinapaldehyde) were investigated against 65 strains of Candida (six standard, 39 fluconazole-sensitive and 20 fluconazole-resistant). MICs of cinnamaldehyde, coniferyl aldehyde and sinapaldehyde ranged from 100 to 500 µg ml(-1), 100 to 300 µg ml(-1) and 100 to 200 µg ml(-1), respectively. All tested isolates showed a marked sensitivity towards these aldehydes in spot and time-kill assays. Sinapaldehyde was found to be the most effective, followed by coniferyl aldehyde and cinnamaldehyde. At their respective MIC(90) values, the three compounds caused mean inhibition levels of glucose-stimulated H(+)-efflux of 36, 34 and 41 % (cinnamaldehyde), 41, 42 and 47 % (coniferyl aldehyde) and 43, 45 and 51 % (sinapaldehyde) for standard-sensitive, clinical-sensitive and clinical-resistant isolates, respectively. Inhibition levels of H(+)-efflux caused by plasma membrane ATPase inhibitors N,N'-dicyclohexylcarbodiimide (100 µM) and diethylstilbestrol (10 µM) were 34, 45 and 44 %, and 57, 39 and 35 %, for standard-sensitive, clinical-sensitive and clinical-resistant isolates, respectively. Intracellular pH (pHi) was found to decrease by 0.34, 0.42 and 0.50 units following incubation with three tested aldehydes from the control pHi of 6.70. Scanning electron microscopy and transmission electron microscopy analysis was performed on a representative strain, C. albicans 10261, showing alterations in morphology, cell wall, plasma membrane damage and lysis. Haemolytic activity of the three compounds varied from 10 to 15 % at their highest MIC compared to an activity level of 20 % shown by fluconazole at 30 µg ml(-1). In conclusion, this study shows significant activity of cinnamic aldehydes against Candida, including azole-resistant strains, suggesting that these molecules can be developed as antifungals.

  9. Assessment and predictor determination of indoor aldehyde levels in Paris newborn babies' homes.

    Science.gov (United States)

    Dassonville, C; Demattei, C; Laurent, A-M; Le Moullec, Y; Seta, N; Momas, I

    2009-08-01

    Exposure to indoor chemical air pollutants expected to be potentially involved in allergic respiratory diseases in infants is poorly documented. A specific environmental investigation included in a birth cohort study was carried out to first assess indoor airborne aldehyde levels, using passive devices and their variability within 1 year (1, 6, 9 and 12 months) in the bedroom of 196 Paris infants, and second, to identify predictors for aldehyde concentrations using interviewer administered questionnaires about housing factors. Comfort parameters and carbon dioxide levels were measured simultaneously. Aldehydes were detected in almost all dwellings and geometric mean levels (geometric standard deviation) at the first visit were respectively for formaldehyde, acetaldehyde, hexanal, and pentanal 19.4 (1.7) microg/m(3), 8.9 (1.8) microg/m(3), 25.3 (3.1) microg/m(3), 3.7 (2.3) microg/m(3), consistent with earlier published results. Generalized Estimating Equation multivariate analyses showed that, apart from comfort parameters, aeration and season, the main indoor aldehyde sources were either continuous (building materials and coverings especially when they were new) or discontinuous (smoking, use of air fresheners and cleaning products, DIY etc...). Finally, the data collected by questionnaires should be sufficient to enable us to classify each infant in our cohort study according to his/her degree of exposure to the main aldehydes. This analysis contributed to document indoor aldehyde levels in Parisian homes and to identify factors determining these levels. In the major part of newborn babies' homes, indoor formaldehyde levels were above the guideline value of 10 microg/m(3) proposed by the French Agency for Environmental and Occupational Health Safety for long-term exposure. Given this result, it is essential to study the health impact of exposure to aldehydes especially formaldehyde on the incidence of respiratory and allergic symptoms, particularly during the

  10. Occupational exposure of aldehydes resulting from the storage of wood pellets.

    Science.gov (United States)

    Rahman, Mohammad Arifur; Rossner, Alan; Hopke, Philip K

    2017-06-01

    An exposure assessment was conducted to investigate the potential for harmful concentrations of airborne short chain aldehydes emitted from recently stored wood pellets. Wood pellets can emit a number of airborne aldehydes include acetaldehyde, formaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and hexanal. Exposure limits have been set for these compounds since they can result in significant irritation of the upper respiratory system at elevated concentrations. Formaldehyde is a recognized human carcinogen and acetaldehyde is an animal carcinogen. Thus, air sampling was performed in a wood pellet warehouse at a pellet mill, two residential homes with bulk wood pellet storage bins, and in controlled laboratory experiments to evaluate the risk to occupants. Using NIOSH method 2539, sampling was conducted in five locations in the warehouse from April-June 2016 when it contained varying quantities of bagged pellets as well as two homes with ten ton bulk storage bins. The aldehyde concentrations were found to increase with the amount of stored pellets. Airborne concentrations of formaldehyde were as high as 0.45 ppm in the warehouse exceeding the NIOSH REL-C, and ACGIH TLV-C occupational exposure limits (OELs). The concentrations of aldehydes measured in the residential bins were also elevated indicating emissions may raise indoor air quality concerns for occupants. While individual exposures are of concern the combined irritant effect of all the aldehydes is a further raise the concerns for building occupants. To minimize exposure and the risk of adverse health effects to a building's occupants in storage areas with large quantities of pellets, adequate ventilation must be designed into storage areas.

  11. Aldehydic acids in frying oils: formation, toxicological significance and analysis

    Directory of Open Access Journals (Sweden)

    Kamal-Eldin, Afaf

    1996-10-01

    Full Text Available Aldehydic acids are generated in oxidized lipids as a result of decomposition of hydroperoxides by (β-scission reactions. Aldehydes are known to interact with proteins and DNA and to impair enzymatic functions. Aldehydic esters from oxidized lipids were reabsorbed to a significant extent in rats. This paper reviews the mechanism of formation of esterified aldehydic acids in frying oils and their physiological/toxicological effects. The paper also gives an overview of relevant basic analytical techniques that needs to be improved to establish reliable quantitative method (s.

    Ácidos aldehídicos son producidos en lípidos oxidados como resultado de la descomposición de hidroperóxidos por reacciones de (β-escición. Es conocido que los aldehídos interaccionan con las proteínas y el ADN y debilitan las funciones enzimáticas. Los esteres aldehídicos de lípidos oxidados fueron reabsorbidos en una cantidad significativa en ratas. Este artículo revisa los mecanismos de formación de ácidos aldehídicos esterificados en aceites de fritura y sus efectos fisiológicos/toxicológicos. El artículo también ofrece una visión de conjunto de las técnicas analíticas básicas que necesitan ser mejoradas para establecer métodos cuantitativos fiables.

  12. Heat-stable, FE-dependent alcohol dehydrogenase for aldehyde detoxification

    Science.gov (United States)

    Elkins, James G.; Clarkson, Sonya

    2018-04-24

    The present invention relates to microorganisms and polypeptides for detoxifying aldehydes associated with industrial fermentations. In particular, a heat-stable, NADPH- and iron-dependent alcohol dehydrogenase was cloned from Thermoanaerobacter pseudethanolicus 39E and displayed activity against a number of aldehydes including inhibitory compounds that are produced during the dilute-acid pretreatment process of lignocellulosic biomass before fermentation to biofuels. Methods to use the microorganisms and polypeptides of the invention for improved conversion of bio mass to biofuel are provided as well as use of the enzyme in metabolic engineering strategies for producing longer-chain alcohols from sugars using thermophilic, fermentative microorganisms.

  13. Effects of the biodiesel blend fuel on aldehyde emissions from diesel engine exhaust

    Science.gov (United States)

    Peng, Chiung-Yu; Yang, Hsi-Hsien; Lan, Cheng-Hang; Chien, Shu-Mei

    Interest in use of biodiesel fuels derived from vegetable oils or animal fats as alternative fuels for petroleum-based diesels has increased due to biodiesels having similar properties of those of diesels, and characteristics of renewability, biodegradability and potential beneficial effects on exhaust emissions. Generally, exhaust emissions of regulated pollutants are widely studied and the results favor biodiesels on CO, HC and particulate emissions; however, limited and inconsistent data are showed for unregulated pollutants, such as carbonyl compounds, which are also important indicators for evaluating available vehicle fuels. For better understanding biodiesel, this study examines the effects of the biodiesel blend fuel on aldehyde chemical emissions from diesel engine exhausts in comparison with those from the diesel fuel. Test engines (Mitsubishi 4M40-2AT1) with four cylinders, a total displacement of 2.84 L, maximum horsepower of 80.9 kW at 3700 rpm, and maximum torque of 217.6 N m at 2000 rpm, were mounted and operated on a Schenck DyNAS 335 dynamometer. Exhaust emission tests were performed several times for each fuel under the US transient cycle protocol from mileages of 0-80,000 km with an interval of 20,000 km, and two additional measurements were carried out at 40,000 and 80,000 km after maintenance, respectively. Aldehyde samples were collected from diluted exhaust by using a constant volume sampling system. Samples were extracted and analyzed by the HPLC/UV system. Dominant aldehydes of both fuels' exhausts are formaldehyde and acetaldehyde. These compounds together account for over 75% of total aldehyde emissions. Total aldehyde emissions for B20 (20% waste cooking oil biodiesel and 80% diesel) and diesel fuels are in the ranges of 15.4-26.9 mg bhp-h -1 and 21.3-28.6 mg bhp-h -1, respectively. The effects of increasing mileages and maintenance practice on aldehyde emissions are insignificant for both fuels. B20 generates slightly less emission than

  14. Regulation of expression of pectate lyase genes pelA, pelD, and pelE in Erwinia chrysanthemi.

    Science.gov (United States)

    Reverchon, S; Robert-Baudouy, J

    1987-06-01

    The regulation of pelA, pelD, and pelE genes encoding three of the five major pectate lyase isoenzymes (PLa, PLd, and PLe) in Erwinia chrysanthemi B374 was analyzed by using genetic fusions to lacZ. These three genes are clustered on a 5-kilobase DNA fragment in the order pelD-pelE-pelA and constitute three independent transcriptional units. We localized the pelDEA cluster near the pro-1 marker on the genetic map of B374 by chromosomal mobilization with RP4::mini-Mu plasmid pULB110. Three classes of regulatory mutations responsible for constitutive pectate lyase synthesis have been described (kdgR, gpiR, and cri). We studied the effects of each mutation on pelE, pelD, and pelA expression independently. The mutations kdgR and gpiR mainly affect the expression of pelE and pelD, although PLa synthesis is slightly increased. The cri mutation results in a low level of constitutive expression of the three pel genes, but it is a pleiotropic mutation since other genes not involved in pectinolysis are also affected. In addition, we demonstrated that exuR, a negative regulatory gene governing the catabolism of hexuronates, does not modify the expression of pel genes. The frequency of gpiR or cri mutations (about 10(-8)) and the resulting constitutivity of pectate lyase synthesis suggest that these genes act as negative regulatory genes in addition to kdgR, which is already known to encode a repressor. Moreover, we found that expression of pel-lac fusions carried on pBR322 derivatives was higher in E. chrysanthemi than in Escherichia coli; this fact suggests the existence of positive regulation of pectate lyase synthesis in E. chrysanthemi.

  15. Organic acids and aldehydes in rainwater in a northwest region of Spain

    Energy Technology Data Exchange (ETDEWEB)

    Pena, R.M.; Garcia, S.; Herrero, C. [Universidad de Santiago de Compostela, Lugo (Spain). Departamento de Quimica Analitica, Nutricion y Bromatologia

    2002-11-01

    During a 1 year period, measurements of carboxylic acids and aldehydes were carried out in rainwater samples collected at nine different sites in NW Spain surrounding a thermal power plant in order to determine concentration levels and sources. In addition, certain major ions (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}) were also determined. Aldehyde and carboxylic acid concentration patterns and their effects on rainwater composition concerning temporal, seasonal and spatial variations were evaluated. Among carboxylic acids, formic and acetic were predominant (VWA 7.0 and 8.3 {mu}M), while formaldehyde and acroleine were the dominant aldehydes (VWA 0.42 and 1.25 {mu}M). Carboxylic acids were estimated to account for 27.5% of the total free acidity (TFA), whereas sulphuric and nitric acid accounted for 46.2% and 26.2%, respectively. Oxalic acid was demonstrated to be an important contributing compound to the acidification in rainwater representing 7.1% of the TFA. The concentration of aldehydes and carboxylic acids, which originated mainly from biogenic emissions in the area studied, was strongly dependent on the season of the year (growing and non-growing). The ratios of formic to acetic acids are considerably different in the two seasons suggesting that there exist distinct sources in both growing and non-growing seasons. Principal component analysis was applied in order to elucidate the sources of aldehydes and organic acids in rainwater. The prevalence of natural vegetative origins for both of these compounds versus anthropogenic emissions was demonstrated and the importance of the oxidation of aldehydes as a relevant source of organic acids was also established. (author)

  16. Reactions of the radical cations of aliphatic aldehydes in freon matrices

    International Nuclear Information System (INIS)

    Belevskij, V.N.; Belopushkin, S.I.; Feldman, V.I.

    1985-01-01

    ESR spectra of γ-irradiated solutions of acetic and propionic aldehydes in freon-11 and freon-113 affected by aldehyde concentration, temperature, and the action of light were studied. It is shown that the radical cations are converted into neutral radicals, and the cations CHsub(3)CHsub(2)CHOsup(+). are converted to RCO and CHsub(3)CHCHO due to ion-molecular reactions of proton transfer of hydrogen atom transfer. (author)

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

    Science.gov (United States)

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

    2004-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  19. Direct chemoselective synthesis of glyconanoparticles from unprotected reducing glycans and glycopeptide aldehydes

    DEFF Research Database (Denmark)

    Thygesen, Mikkel Boas; Sørensen, Kasper Kildegaard; Cló, Emiliano

    2009-01-01

    Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell.......Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell....

  20. Structural insights into RipC, a putative citrate lyase β subunit from a Yersinia pestis virulence operon

    International Nuclear Information System (INIS)

    Torres, Rodrigo; Chim, Nicholas; Sankaran, Banumathi; Pujol, Céline; Bliska, James B.; Goulding, Celia W.

    2011-01-01

    Comparison of the 2.45 Å resolution crystal structure of homotrimeric RipC, a putative citrate lyase β subunit from Y. pestis, with structural homologs reveals conserved RipC residues that are implicated in CoA binding. Yersinia pestis remains a threat, with outbreaks of plague occurring in rural areas and its emergence as a weapon of bioterrorism; thus, an improved understanding of its various pathogenicity pathways is warranted. The rip (required for intracellular proliferation) virulence operon is required for Y. pestis survival in interferon-γ-treated macrophages and has been implicated in lowering macrophage-produced nitric oxide levels. RipC, one of three gene products from the rip operon, is annotated as a citrate lyase β subunit. Furthermore, the Y. pestis genome lacks genes that encode citrate lyase α and γ subunits, suggesting a unique functional role of RipC in the Y. pestisrip-mediated survival pathway. Here, the 2.45 Å resolution crystal structure of RipC revealed a homotrimer in which each monomer consists of a (β/α) 8 TIM-barrel fold. Furthermore, the trimeric state was confirmed in solution by size-exclusion chromatography. Through sequence and structure comparisons with homologous proteins, it is proposed that RipC is a putative CoA- or CoA-derivative binding protein

  1. Structural insights into the bacterial carbon - phosphorus lyase machinery

    DEFF Research Database (Denmark)

    Seweryn, Paulina; Van, Lan Bich; Kjeldgaard, Morten

    2015-01-01

    Phosphorus is required for all life and microorganisms can extract it from their environment through several metabolic pathways. When phosphate is in limited supply, some bacteria are able to use phosphonate compounds, which require specialized enzymatic machinery to break the stable carbon......–phosphorus (C–P) bond. Despite its importance, the details of how this machinery catabolizes phosphonates remain unknown. Here we determine the crystal structure of the 240-kilodalton Escherichia coli C–P lyase core complex (PhnG–PhnH–PhnI–PhnJ; PhnGHIJ), and show that it is a two-fold symmetric hetero...

  2. Microenvironmental characteristics important for personal exposures to aldehydes in Sacramento, CA, and Milwaukee, WI

    Science.gov (United States)

    Raymer, J. H.; Akland, G.; Johnson, T. R.; Long, T.; Michael, L.; Cauble, L.; McCombs, M.

    Oxygenated additives in gasoline are designed to decrease the ozone-forming hydrocarbons and total air toxics, yet they can increase the emissions of aldehydes and thus increase human exposure to these toxic compounds. This paper describes a study conducted to characterize targeted aldehydes in microenvironments in Sacramento, CA, and Milwaukee, WI, and to improve our understanding of the impact of the urban environment on human exposure to air toxics. Data were obtained from microenvironmental concentration measurements, integrated, 24-h personal measurements, indoor and outdoor pollutant monitors at the participants' residences, from ambient pollutant monitors at fixed-site locations in each city, and from real-time diaries and questionnaires completed by the technicians and participants. As part of this study, a model to predict personal exposures based on individual time/activity data was developed for comparison to measured concentrations. Predicted concentrations were generally within 25% of the measured concentrations. The microenvironments that people encounter daily provide for widely varying exposures to aldehydes. The activities that occur in those microenvironments can modulate the aldehyde concentrations dramatically, especially for environments such as "indoor at home." By considering personal activity, location (microenvironment), duration in the microenvironment, and a knowledge of the general concentrations of aldehydes in the various microenvironments, a simple model can do a reasonably good job of predicting the time-averaged personal exposures to aldehydes, even in the absence of monitoring data. Although concentrations of aldehydes measured indoors at the participants' homes tracked well with personal exposure, there were instances where personal exposures and indoor concentrations differed significantly. Key to the ability to predict exposure based on time/activity data is the quality and completeness of the microenvironmental

  3. Quantitative analysis of aldehydes in canned vegetables using static headspace-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Serrano, María; Gallego, Mercedes; Silva, Manuel

    2017-11-17

    Volatile aldehydes appear in canned vegetables as constituents and some of them can also be present as disinfection by-products (DBPs) because of the contact between vegetables and treated water. This paper describes two static headspace-gas chromatography-mass spectrometry (SHS-GC-MS) methods to determine 15 aldehydes in both the solid and the liquid phases of canned vegetables. The treatment for both phases of samples was carried out simultaneously into an SHS unit, including the leaching of the aldehydes (from the vegetable), their derivatization and volatilization of the oximes formed. Detection limits were obtained within the range of 15-400μg/kg and 3-40μg/L for aldehydes in the solid and the liquid phases of the food, respectively. The relative standard deviation was lower than 7% -for the whole array of the target analytes-, the trueness evaluated by recovery experiments provided %recoveries between 89 and 99% and short- and long-term stability studies indicated there was no significant variation in relative peak areas of all aldehydes in both phases of canned vegetables after their storing at 4°C for two weeks. The study of the origin of the 15 aldehydes detected between both phases of canned vegetables showed that: i) the presence of 13 aldehydes -at average concentrations of 2.2-39μg/kg and 0.25-71μg/L for the solid and the liquid phases, respectively- is because they are natural constituents of vegetables; and ii) the presence of glyoxal and methylglyoxal -which are mainly found in the liquid phase (average values, 1.4-4.1μg/L)- is ascribed to the use of treated water, thereby being DBPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Sphingosine-1-Phosphate Lyase Deficient Cells as a Tool to Study Protein Lipid Interactions.

    Directory of Open Access Journals (Sweden)

    Mathias J Gerl

    Full Text Available Cell membranes contain hundreds to thousands of individual lipid species that are of structural importance but also specifically interact with proteins. Due to their highly controlled synthesis and role in signaling events sphingolipids are an intensely studied class of lipids. In order to investigate their metabolism and to study proteins interacting with sphingolipids, metabolic labeling based on photoactivatable sphingoid bases is the most straightforward approach. In order to monitor protein-lipid-crosslink products, sphingosine derivatives containing a reporter moiety, such as a radiolabel or a clickable group, are used. In normal cells, degradation of sphingoid bases via action of the checkpoint enzyme sphingosine-1-phosphate lyase occurs at position C2-C3 of the sphingoid base and channels the resulting hexadecenal into the glycerolipid biosynthesis pathway. In case the functionalized sphingosine looses the reporter moiety during its degradation, specificity towards sphingolipid labeling is maintained. In case degradation of a sphingosine derivative does not remove either the photoactivatable or reporter group from the resulting hexadecenal, specificity towards sphingolipid labeling can be achieved by blocking sphingosine-1-phosphate lyase activity and thus preventing sphingosine derivatives to be channeled into the sphingolipid-to-glycerolipid metabolic pathway. Here we report an approach using clustered, regularly interspaced, short palindromic repeats (CRISPR-associated nuclease Cas9 to create a sphingosine-1-phosphate lyase (SGPL1 HeLa knockout cell line to disrupt the sphingolipid-to-glycerolipid metabolic pathway. We found that the lipid and protein compositions as well as sphingolipid metabolism of SGPL1 knock-out HeLa cells only show little adaptations, which validates these cells as model systems to study transient protein-sphingolipid interactions.

  5. Effects of sh-reagents on rat hepatic aldehyde dehydrogenase activity

    Energy Technology Data Exchange (ETDEWEB)

    Konoplitskaya, K.L.; Kuz' mina, G.I.; Grigor' yeva, M.V.; Poznyakova, T.N.

    The liver serves as the primary organ for the oxidation of ingested ethanol via a pathway involving alcohol- and aldehyde dehydrogenase. In view of the problem of alcoholism, three enzymes are of particular interest in understanding the biochemical mechanism that may be involved in alcohol addiction and in the formulation of therapeutic approaches. While alcohol dehydrogenase has been studied in considerable detail, current attention is centered on aldehyde dehydrogenase. A comparative analysis of the effects of a series of SH-active reagents - tetraethylthiuram disulfide (TETD), 5,5-dithiobisnitrobenzoic acid (DTNB), p-chloromercurybenzoate (PCMB), and N-ethylmaleimide (NEM) - were tested for their effects on the activity of aldehyde dehydrogenase of the hepatic mitochondrial (isozymes I and II) and microsomal (isozyme II) fractions of outbred albino rats. DTNB was found to be inhibited by 100 and 50% mitochondrial isozymes I and II, respectively, and by 20%, the microsomal enzyme under the conditions employed. DTNB and NEM inhibited by 30 and 50% isozymes I and II of the mitochondria, but had no effect on the microsomal isozyme. 24 references, 3 figures.

  6. Formation and accumulation of acetaldehyde and Strecker aldehydes during red wine oxidation

    Science.gov (United States)

    Bueno, Mónica; Marrufo-Curtido, Almudena; Carrascón, Vanesa; Fernández-Zurbano, Purificación; Escudero, Ana; Ferreira, Vicente

    2018-02-01

    The main aim of the present work is to study the accumulation of acetaldehyde and Strecker aldehydes (isobutyraldehyde, 2-methylbutanal, isovaleraldehyde, methional, phenylacetaldehyde) during the oxidation of red wines, and to relate the patterns of accumulation to the wine chemical composition. For that, eight different wines, extensively chemically characterized, were subjected at 25°C to three different controlled O2 exposure conditions: low (10 mg L-1) and medium or high (the stoichiometrically required amount to oxidize all wine total SO2 plus 18 or 32 mg L-1, respectively). Levels of volatile aldehydes and carbonyls were then determined and processed by different statistical techniques. Results showed that young wines (wines) hardly accumulate any acetaldehyde regardless of the O2 consumed. In contrast, aged wines (>3 years-old bottled wines) accumulated acetaldehyde while their content in SO2 was not null, and the aged wine containing lowest polyphenols accumulated it throughout the whole process. Models suggest that the ability of a wine to accumulate acetaldehyde is positively related to its content in combined SO2, in epigallocatechin and to the mean degree of polymerization, and negatively to its content in Aldehyde Reactive Polyphenols (ARPs) which, attending to our models, are anthocyanins and small tannins. The accumulation of Strecker aldehydes is directly proportional to the wine content in the amino acid precursor, being the proportionality factor much higher for aged wines, except for phenylacetaldehyde, for which the opposite pattern was observed. Models suggest that non-aromatic Strecker aldehydes share with acetaldehyde a strong affinity towards ARPs and that the specific pattern of phenylacetaldehyde is likely due to a much reduced reactivity towards ARPs, to the possibility that diacetyl induces Strecker degradation of phenyl alanine and to the potential higher reactivity of this amino acid to some quinones derived from catechin. All this

  7. Formation and Accumulation of Acetaldehyde and Strecker Aldehydes during Red Wine Oxidation

    Directory of Open Access Journals (Sweden)

    Mónica Bueno

    2018-02-01

    Full Text Available The main aim of the present work is to study the accumulation of acetaldehyde and Strecker aldehydes (isobutyraldehyde, 2-methylbutanal, isovaleraldehyde, methional, phenylacetaldehyde during the oxidation of red wines, and to relate the patterns of accumulation to the wine chemical composition. For that, eight different wines, extensively chemically characterized, were subjected at 25°C to three different controlled O2 exposure conditions: low (10 mg L−1 and medium or high (the stoichiometrically required amount to oxidize all wine total SO2 plus 18 or 32 mg L−1, respectively. Levels of volatile aldehydes and carbonyls were then determined and processed by different statistical techniques. Results showed that young wines (<2 years-old bottled wines hardly accumulate any acetaldehyde regardless of the O2 consumed. In contrast, aged wines (>3 years-old bottled wines accumulated acetaldehyde while their content in SO2 was not null, and the aged wine containing lowest polyphenols accumulated it throughout the whole process. Models suggest that the ability of a wine to accumulate acetaldehyde is positively related to its content in combined SO2, in epigallocatechin and to the mean degree of polymerization, and negatively to its content in Aldehyde Reactive Polyphenols (ARPs which, attending to our models, are anthocyanins and small tannins. The accumulation of Strecker aldehydes is directly proportional to the wine content in the amino acid precursor, being the proportionality factor much higher for aged wines, except for phenylacetaldehyde, for which the opposite pattern was observed. Models suggest that non-aromatic Strecker aldehydes share with acetaldehyde a strong affinity toward ARPs and that the specific pattern of phenylacetaldehyde is likely due to a much reduced reactivity toward ARPs, to the possibility that diacetyl induces Strecker degradation of phenyl alanine and to the potential higher reactivity of this amino acid to some

  8. An Efficient Synthesis of 2-Substituted Benzimidazoles via Photocatalytic Condensation of o-Phenylenediamines and Aldehydes.

    Science.gov (United States)

    Kovvuri, Jeshma; Nagaraju, Burri; Kamal, Ahmed; Srivastava, Ajay K

    2016-10-10

    A photocatalytic method has been developed for the efficient synthesis of functionalized benzimidazoles. This protocol involves photocatalytic condensation of o-phenylenediamines with various aldehydes using the Rose Bengal as photocatalyst. The method was found to be general and was successfully employed for accessing pharmaceutically important benzimidazoles by the condensation of aromatic, heteroaromatic and aliphatic aldehydes with o-phenylenediamines, in good-to-excellent yields. Notably, the method was found to be effective for the condensation of less reactive heterocyclic aldehydes with o-phenylenediamines.

  9. One Year Experience of Pheburane® (Sodium Phenylbutyrate) Treatment in a Patient with Argininosuccinate Lyase Deficiency

    OpenAIRE

    Uçar, Sema Kalkan; Ozbaran, Burcu; Altinok, Yasemin Atik; Kose, Melis; Canda, Ebru; Kagnici, Mehtap; Coker, Mahmut

    2015-01-01

    Argininosuccinate lyase deficiency (ASLD) is a urea cycle disorder (UCD) treated with dietary adjustment and nitrogen scavenging agents. “Pheburane®” is a new tasteless and odour-free formulation of sodium phenylbutyrate, indicated in the treatment of UCD.

  10. Identification and characterization of aldehyde oxidases (AOXs) in the cotton bollworm

    Science.gov (United States)

    Xu, Wei; Liao, Yalin

    2017-12-01

    Aldehyde oxidases (AOXs) are a family of metabolic enzymes that oxidize aldehydes into carboxylic acids; therefore, they play critical roles in detoxification and degradation of chemicals. By using transcriptomic and genomic approaches, we successfully identified six putative AOX genes (HarmAOX1-6) from cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). In silico expression profile, reverse transcription (RT)-PCR, and quantitative PCR (qPCR) analyses showed that HarmAOX1 is highly expressed in adult antennae, tarsi, and larval mouthparts, so they may play an important role in degrading plant-derived compounds. HarmAOX2 is highly and specifically expressed in adult antennae, suggesting a candidate pheromone-degrading enzyme (PDE) to inactivate the sex pheromone components (Z)-11-hexadecenal and (Z)-9-hexadecenal. RNA sequencing data further demonstrated that a number of host plants they feed on could significantly upregulate the expression levels of HarmAOX1 in larvae. This study improves our understanding of insect aldehyde oxidases and insect-plant interactions.

  11. Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine.

    Science.gov (United States)

    Harigae, Ryo; Moriyama, Katsuhiko; Togo, Hideo

    2014-03-07

    The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.

  12. Mechanism of catalytic action of oxide systems in reactions of aldehyde oxidation to carboxylic acids

    International Nuclear Information System (INIS)

    Andrushkevich, T.V.

    1997-01-01

    Mechanism of selective action of oxide catalysts (on the base of V 2 O 4 , MoO 3 ) of aldehyde oxidation to acids is considered, reaction acrolein oxidation to acrylic acid is taken as an example. Multistage mechanism of the process is established; it involves consequent transformation of coordination-bonded aldehyde into carbonyl-bonded aldehyde and symmetric carboxylate. Principles of active surface construction are formulated, they take into account the activity of stabilization center of concrete intermediate compound and bond energy of oxygen with surface. (author)

  13. Study on physico-chemical properties of dialdehyde yam starch with different aldehyde group contents

    International Nuclear Information System (INIS)

    Zhang, Liming; Liu, Peng; Wang, Yugao; Gao, Wenyuan

    2011-01-01

    Dialdehyde yam starches (DASs) are prepared and characterized. Compared with native starch, viscosity average molecular weight of DASs decreases, and the extent of degradation depends on content of the aldehyde groups. Fourier transform infrared (FT-IR) spectra confirm that the characteristic peak for C=O group at 1732 cm -1 is enhanced with the increasing of content of the aldehyde groups. Scanning electron microscopy (SEM) micrographs show that the surface of starch granules becomes wrinkled. X-ray diffraction (XRD) patterns clearly indicate that their crystallinity decreases with the increasing content of the aldehyde groups before they become amorphous at higher oxidation states. The experimental results of thermogravimetric analysis (TGA) show that DASs have poor stability as compared to native starch. With the increase in content of the aldehyde groups, the thermal stability of DAS declines gradually. According to the results of differential scanning calorimetry (DSC), gelatinization temperature (T o and T p ) of DASs are increased, whereas the gelatinization enthalpy decreased.

  14. Partial Reduction of Esters to Aldehydes Using a Novel Modified Red-Al Reducing Agent

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Won Kyu; Kang, Daehoon; An, Duk Keun [Kangwon National Univ., Chunchon (Korea, Republic of)

    2014-07-15

    We have developed a convenient alternative method for the synthesis of aldehydes from both aromatic and aliphatic esters in very good to excellent yields in the absence of any additives using a modified Red-Al that was easily prepared by reacting commercially available Red-Al with cis-2,6-dimethyl morpholine. The advantages of the present methodology are as follows: simple preparation procedure of the reducing agent, improved product yields, convenient reaction temperature, and short reaction times. Therefore, the new reagent has great potential to be a useful alternative partial reducing agent for the synthesis of aldehydes from esters in organic synthesis. Aldehydes are valuable building blocks and reactive intermediates in organic synthesis. The general and classical syntheses of aldehydes from esters involve reduction-oxidation and partial reduction using efficient partial reducing agents. Obviously, one-step partial reduction methods are more useful than two-step reduction-oxidation methods owing to their simplicity, and generality in organic synthesis.

  15. Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

    Directory of Open Access Journals (Sweden)

    Lavín Paris

    2016-09-01

    Full Text Available Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta, in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17ºC and maximum temperature (20°C of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C, agarose (50°C and alginate (30°C during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

  16. Size-Selective Oxidation of Aldehydes with Zeolite Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Højholt, Karen Thrane; Laursen, Anders Bo; Kegnæs, Søren

    2011-01-01

    Here, we report a synthesis and catalytic study of hybrid materials comprised of 1–3 nm sinter-stable Au nanoparticles in MFI-type zeolites. An optional post-treatment in aqua regia effectively remove Au from the external surfaces. The size-selective aerobic aldehyde oxidation verifies that the a......Here, we report a synthesis and catalytic study of hybrid materials comprised of 1–3 nm sinter-stable Au nanoparticles in MFI-type zeolites. An optional post-treatment in aqua regia effectively remove Au from the external surfaces. The size-selective aerobic aldehyde oxidation verifies...... that the active Au is accessible only through the zeolite micropores....

  17. Semi-catalytic reduction of secondary amides to imines and aldehydes.

    Science.gov (United States)

    Lee, Sun-Hwa; Nikonov, Georgii I

    2014-06-21

    Secondary amides can be reduced by silane HSiMe2Ph into imines and aldehydes by a two-stage process involving prior conversion of amides into iminoyl chlorides followed by catalytic reduction mediated by the ruthenium complex [Cp(i-Pr3P)Ru(NCCH3)2]PF6 (1). Alkyl and aryl amides bearing halogen, ketone, and ester groups were converted with moderate to good yields under mild reaction conditions to the corresponding imines and aldehydes. This procedure does not work for substrates bearing the nitro-group and fails for heteroaromatic amides. In the case of cyano substituted amides, the cyano group is reduced to imine.

  18. Nitrite promotes protein carbonylation and Strecker aldehyde formation in experimental fermented sausages: are both events connected?

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    P. O. Wennberg

    2010-08-01

    Full Text Available Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene, the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA via methacrolein (a C4-unsaturated aldehyde under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232 is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(OOONO2 formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3–8, the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

  20. Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

    Science.gov (United States)

    Chan, A. W. H.; Chan, M. N.; Surratt, J. D.; Chhabra, P. S.; Loza, C. L.; Crounse, J. D.; Yee, L. D.; Flagan, R. C.; Wennberg, P. O.; Seinfeld, J. H.

    2010-08-01

    Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene), the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA) via methacrolein (a C4-unsaturated aldehyde) under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN) as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232) is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(O)OONO2) formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3-8), the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

  1. Urban and rural ambient air aldehyde levels in Schenectady, New York and on Whiteface Mountain, New York

    Energy Technology Data Exchange (ETDEWEB)

    Schulam, P; Newbold, R; Hull, L A

    1985-01-01

    The air in the city of Schenectady, NY was sampled daily and analyzed for the presence of low molecular weight aldehydes during the months of June-August 1983. The diurnal variation of the aldehyde concentrations was also determined over a two day period during August. The dominant aldehyde was formaldehyde and its concentration varied from about 1-31 ppb. There was also observed a significant daily variation that appeared to correlate with traffic conditions. The technique was also used to monitor the aldehyde levels on the summit of Whiteface Mountain in Wilmington, NY at the SUNYA Atmospheric Sciences Research Center. The monitoring was done on a daily basis during the week of 14-20 August and, during that week, every 3 h for a 3-day period. The two dominant aldehydes were formaldehyde and acetaldehyde and they varied in concentration from about 0.8-2.6 and 0.2-0.8 ppb, respectively.

  2. Aldehyde-Selective Wacker-Type Oxidation of Unbiased Alkenes Enabled by a Nitrite Co-Catalyst

    KAUST Repository

    Wickens, Zachary K.; Morandi, Bill; Grubbs, Robert H.

    2013-01-01

    Breaking the rules: Reversal of the high Markovnikov selectivity of Wacker-type oxidations was accomplished using a nitrite co-catalyst. Unbiased aliphatic alkenes can be oxidized with high yield and aldehyde selectivity, and several functional groups are tolerated. 18O-labeling experiments indicate that the aldehydic O atom is derived from the nitrite salt.

  3. Aldehyde-Selective Wacker-Type Oxidation of Unbiased Alkenes Enabled by a Nitrite Co-Catalyst

    KAUST Repository

    Wickens, Zachary K.

    2013-09-13

    Breaking the rules: Reversal of the high Markovnikov selectivity of Wacker-type oxidations was accomplished using a nitrite co-catalyst. Unbiased aliphatic alkenes can be oxidized with high yield and aldehyde selectivity, and several functional groups are tolerated. 18O-labeling experiments indicate that the aldehydic O atom is derived from the nitrite salt.

  4. The Arabidopsis aldehyde oxidase 3 (AA03) gene product catalyzes the final step in abscisic acid biosynthesis in leaves

    NARCIS (Netherlands)

    Seo, M.; Peeters, A.J.M.; Koiwai, H.; Oritani, T.; Marion-Poll, A.; Zeevaart, J.A.D.; Koornneef, M.; Kamiya, Y.; Koshiba, T.

    2000-01-01

    Abscisic acid (ABA) is a plant hormone involved in seed development and germination and in responses to various environmental stresses. The last step of ABA biosynthesis involves oxidation of abscisic aldehyde, and aldehyde oxidase (EC 1.2.3.1) is thought to catalyze this reaction. An aldehyde

  5. Mode of action of pectin lyase A of Aspergillus niger on differently C6-substituted oligogalacturonides

    NARCIS (Netherlands)

    Alebeek, van G.J.W.M.; Christensen, T.M.I.E.; Schols, H.A.; Mikkelsen, J.D.; Voragen, A.G.J.

    2002-01-01

    A thorough investigation of the mode of action of Aspergillus niger (4M-147) pectin lyase A (PLA) on differently C6-substituted oligogalacturonides is described. PLA appeared to be very specific for fully methyl-esterified oligogalacturonides: removal of the methyl-ester or changing the type of

  6. Kinetic Resolution and Stereoselective Synthesis of 3-Substituted Aspartic Acids by Using Engineered Methylaspartate Ammonia Lyases

    NARCIS (Netherlands)

    Raj, Hans; Szymanski, Wiktor; Villiers, Jandré de; Puthan Veetil, Vinod; Quax, Wim J.; Shimamoto, Keiko; Janssen, Dick B.; Feringa, Ben L.; Poelarends, Gerrit J.

    2013-01-01

    Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described.

  7. Nephelauxetic and hypersensitive nature of neodymium(III) complexes with α-pyridyl-thiosemicarbazide and its furfural-2-aldehyde and thiophene-2-aldehyde derivatives

    International Nuclear Information System (INIS)

    Jain, C.L.; Mundley, P.N.; Khandelwal, B.E.

    1986-01-01

    A new series of octahedral Nd(III) complexes with recently synthesised α-pyridylthiosemicarbazide (C 6 H 8 N 4 S or 'PT'), N-(α-pyridyl)furfural-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 SO or 'PFT') and N-(α-pyridyl)thiophene-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 S 2 or 'PTT'), have been isolated and characterised on the basis of their elemental analysis, magnetic and reflectance and ir spectral data revealing 'PT' as bidentate (pyridinic-N and thioketo-S) and 'PFT' and 'PTT' as tetradentate with pyridinic-N, thioketo-S, imine-N and furfuryl-O/thiophenyl-S as donor sites. Isolation and characterisation of Nd(III) complexes with 'PT', 'PFT' and 'PTT' and their nephelauxetic and hypersensitive nature are studied in order to evaluate the stereochemistry of the ligands around Nd(III) ion. (author). 12 refs., 2 tables

  8. Genotoxic consequences of endogenous aldehydes on mouse haematopoietic stem cell function.

    Science.gov (United States)

    Garaycoechea, Juan I; Crossan, Gerry P; Langevin, Frederic; Daly, Maria; Arends, Mark J; Patel, Ketan J

    2012-09-27

    Haematopoietic stem cells (HSCs) regenerate blood cells throughout the lifespan of an organism. With age, the functional quality of HSCs declines, partly owing to the accumulation of damaged DNA. However, the factors that damage DNA and the protective mechanisms that operate in these cells are poorly understood. We have recently shown that the Fanconi anaemia DNA-repair pathway counteracts the genotoxic effects of reactive aldehydes. Mice with combined inactivation of aldehyde catabolism (through Aldh2 knockout) and the Fanconi anaemia DNA-repair pathway (Fancd2 knockout) display developmental defects, a predisposition to leukaemia, and are susceptible to the toxic effects of ethanol-an exogenous source of acetaldehyde. Here we report that aged Aldh2(-/-) Fancd2(-/-) mutant mice that do not develop leukaemia spontaneously develop aplastic anaemia, with the concomitant accumulation of damaged DNA within the haematopoietic stem and progenitor cell (HSPC) pool. Unexpectedly, we find that only HSPCs, and not more mature blood precursors, require Aldh2 for protection against acetaldehyde toxicity. Additionally, the aldehyde-oxidizing activity of HSPCs, as measured by Aldefluor stain, is due to Aldh2 and correlates with this protection. Finally, there is more than a 600-fold reduction in the HSC pool of mice deficient in both Fanconi anaemia pathway-mediated DNA repair and acetaldehyde detoxification. Therefore, the emergence of bone marrow failure in Fanconi anaemia is probably due to aldehyde-mediated genotoxicity restricted to the HSPC pool. These findings identify a new link between endogenous reactive metabolites and DNA damage in HSCs, and define the protective mechanisms that counteract this threat.

  9. Role and structural characterization of plant aldehyde dehydrogenases from family 2 and family 7

    Czech Academy of Sciences Publication Activity Database

    Končitíková, R.; Vigouroux, A.; Kopečná, M.; Andree, T.; Bartoš, Jan; Šebela, M.; Moréra, S.; Kopečný, D.

    2015-01-01

    Roč. 468, Part: 1 (2015), s. 109-123 ISSN 0264-6021 R&D Projects: GA ČR GA15-22322S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : aldehyde dehydrogenase 2 (ALDH2) * aldehyde dehydrogenase 7 (ALDH7) * benzaldehyde Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.562, year: 2015

  10. Applicability of the theory of thermodynamic similarity to predict the enthalpies of vaporization of aliphatic aldehydes

    Science.gov (United States)

    Esina, Z. N.; Korchuganova, M. R.

    2015-06-01

    The theory of thermodynamic similarity is used to predict the enthalpies of vaporization of aliphatic aldehydes. The predicted data allow us to calculate the phase diagrams of liquid-vapor equilibrium in a binary water-aliphatic aldehyde system.

  11. Origin of low-molecular mass aldehydes as disinfection by-products in beverages.

    Science.gov (United States)

    Serrano, María; Gallego, Mercedes; Silva, Manuel

    2017-09-01

    A novel, simple and automatic method based on static headspace-gas chromatography-mass spectrometry has been developed to determine 10 low-molecular mass aldehydes that can be found in beverages, coming from the treated water used in their production. These aldehydes are the most frequently found in treated water as water disinfection by-products, so they can be used as indicators of the addition of treated water to beverages. The study covered a large number of fruit juices and soft drinks. The presence of the whole array of analytes is related to the contact with treated water during beverage production, mainly by the addition of treated water as ingredient. In particular, propionaldehyde, valeraldehyde and benzaldehyde can be used as indicators of the addition of treated water in these kinds of beverages. Among the ten aldehydes, only formaldehyde and acetaldehyde are naturally present in all kinds of fruit, and their concentrations are related to stage of the ripening of the fruit.

  12. A catalytic reactor for the organocatalyzed enantioselective continuous flow alkylation of aldehydes.

    Science.gov (United States)

    Porta, Riccardo; Benaglia, Maurizio; Puglisi, Alessandra; Mandoli, Alessandro; Gualandi, Andrea; Cozzi, Pier Giorgio

    2014-12-01

    The use of immobilized metal-free catalysts offers the unique possibility to develop sustainable processes in flow mode. The challenging intermolecular organocatalyzed enantioselective alkylation of aldehydes was performed for the first time under continuous flow conditions. By using a packed-bed reactor filled with readily available supported enantiopure imidazolidinone, different aldehydes were treated with three distinct cationic electrophiles. In the organocatalyzed α-alkylation of aldehydes with 1,3-benzodithiolylium tetrafluoroborate, excellent enantioselectivities, in some cases even better than those obtained in the flask process (up to 95% ee at 25 °C), and high productivity (more than 3800 h(-1) ) were obtained, which thus shows that a catalytic reactor may continuously produce enantiomerically enriched compounds. Treatment of the alkylated products with Raney-nickel furnished enantiomerically enriched α-methyl derivatives, key intermediates for active pharmaceutical ingredients and natural products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Olfactory sensitivity for sperm-attractant aromatic aldehydes: a comparative study in human subjects and spider monkeys.

    Science.gov (United States)

    Kjeldmand, Luna; Salazar, Laura Teresa Hernandez; Laska, Matthias

    2011-01-01

    Using a three-alternative forced-choice ascending staircase procedure, we determined olfactory detection thresholds in 20 human subjects for seven aromatic aldehydes and compared them to those of four spider monkeys tested in parallel using an operant conditioning paradigm. With all seven odorants, both species detected concentrations lyral, and 3-phenylpropanal. No significant correlation between presence/absence of an oxygen-containing moiety attached to the benzene ring or presence/absence of an additional alkyl group next to the functional aldehyde group, and olfactory sensitivity was found in any of the species. However, the presence of a tertiary butyl group in para position (relative to the functional aldehyde group) combined with a lack of an additional alkyl group next to the functional aldehyde group may be responsible for the finding that both species were most sensitive to bourgeonal.

  14. Diversity of function in the isocitrate lyase enzyme superfamily: the Dianthus caryophyllus petal death protein cleaves alpha-keto and alpha-hydroxycarboxylic acids.

    Science.gov (United States)

    Lu, Zhibing; Feng, Xiaohua; Song, Ling; Han, Ying; Kim, Alexander; Herzberg, Osnat; Woodson, William R; Martin, Brian M; Mariano, Patrick S; Dunaway-Mariano, Debra

    2005-12-20

    The work described in this paper was carried out to define the chemical function a new member of the isocitrate lyase enzyme family derived from the flowering plant Dianthus caryophyllus. This protein (Swiss-Prot entry Q05957) is synthesized in the senescent flower petals and is named the "petal death protein" or "PDP". On the basis of an analysis of the structural contexts of sequence markers common to the C-C bond lyases of the isocitrate lyase/phosphoenolpyruvate mutase superfamily, a substrate screen that employed a (2R)-malate core structure was designed. Accordingly, stereochemically defined C(2)- and C(3)-substituted malates were synthesized and tested as substrates for PDP-catalyzed cleavage of the C(2)-C(3) bond. The screen identified (2R)-ethyl, (3S)-methylmalate, and oxaloacetate [likely to bind as the hydrate, C(2)(OH)(2) gem-diol] as the most active substrates (for each, k(cat)/K(m) = 2 x 10(4) M(-)(1) s(-)(1)). In contrast to the stringent substrate specificities previously observed for the Escherichia coli isocitrate and 2-methylisocitrate lyases, the PDP tolerated hydrogen, methyl, and to a much lesser extent acetate substituents at the C(3) position (S configuration only) and hydoxyl, methyl, ethyl, propyl, and to a much lesser extent isobutyl substituents at C(2) (R configuration only). It is hypothesized that PDP functions in oxalate production in Ca(2+) sequestering and/or in carbon scavenging from alpha-hydroxycarboxylate catabolites during the biochemical transition accompanying petal senescence.

  15. PecS and PecT coregulate the synthesis of HrpN and pectate lyases, two virulence determinants in Erwinia chrysanthemi 3937.

    Science.gov (United States)

    Nasser, William; Reverchon, Sylvie; Vedel, Regine; Boccara, Martine

    2005-11-01

    Erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. Pectinolytic enzymes and, in particular, pectate lyases play a key role in soft rot symptoms; however, the efficient colonization of plants by E. chrysanthemi requires additional factors. These factors include HrpN (harpin), a heat-stable, glycine-rich hydrophilic protein, which is secreted by the type III secretion system. We investigated the expression of hrpN in E. chrysanthemi 3937 in various environmental conditions and different regulatory backgrounds. Using lacZ fusions, hrpN expression was markedly influenced by the carbon source, osmolarity, growth phase, and growth substrate. hrpN was repressed when pectinolysis started and negatively regulated by the repressors of pectate lyase synthesis, PecS and PecT. Primer extension data and in vitro DNA-protein interaction experiments support a model whereby PecS represses hrpN expression by binding to the hrpN regulatory region and inhibiting transcript elongation. The results suggest coordinated regulation of HrpN and pectate lyases by PecS and PecT. A putative model of the synthesis of these two virulence factors in E. chrysanthemi during pathogenesis is presented.

  16. Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils

    OpenAIRE

    Duerr, Mark A.; Aurora, Rajeev; Ford, David A.

    2015-01-01

    α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-l...

  17. Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

    Science.gov (United States)

    Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

    2016-04-15

    This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Lactic acid bacteria involved in cocoa beans fermentation from Ivory Coast: Species diversity and citrate lyase production.

    Science.gov (United States)

    Ouattara, Hadja D; Ouattara, Honoré G; Droux, Michel; Reverchon, Sylvie; Nasser, William; Niamke, Sébastien L

    2017-09-01

    Microbial fermentation is an indispensable process for high quality chocolate from cocoa bean raw material. lactic acid bacteria (LAB) are among the major microorganisms responsible for cocoa fermentation but their exact role remains to be elucidated. In this study, we analyzed the diversity of LAB in six cocoa producing regions of Ivory Coast. Ribosomal 16S gene sequence analysis showed that Lactobacillus plantarum and Leuconostoc mesenteroides are the dominant LAB species in these six regions. In addition, other species were identified as the minor microbial population, namely Lactobacillus curieae, Enterococcus faecium, Fructobacillus pseudoficulneus, Lactobacillus casei, Weissella paramesenteroides and Weissella cibaria. However, in each region, the LAB microbial population was composed of a restricted number of species (maximum 5 species), which varied between the different regions. LAB implication in the breakdown of citric acid was investigated as a fundamental property for a successful cocoa fermentation process. High citrate lyase producer strains were characterized by rapid citric acid consumption, as revealed by a 4-fold decrease in citric acid concentration in the growth medium within 12h, concomitant with an increase in acetic acid and lactic acid concentration. The production of citrate lyase was strongly dependent on environmental conditions, with optimum production at acidic pH (pHfermentation. This study reveals that one of the major roles of LAB in the cocoa fermentation process involves the breakdown of citric acid during the early stage of cocoa fermentation through the activity of citrate lyase. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Catalytic Oxidation of Lignins into the Aromatic Aldehydes: General Process Trends and Development Prospects

    Science.gov (United States)

    Tarabanko, Valery E.; Tarabanko, Nikolay

    2017-01-01

    This review discusses principal patterns that govern the processes of lignins’ catalytic oxidation into vanillin (3-methoxy-4-hydroxybenzaldehyde) and syringaldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde). It examines the influence of lignin and oxidant nature, temperature, mass transfer, and of other factors on the yield of the aldehydes and the process selectivity. The review reveals that properly organized processes of catalytic oxidation of various lignins are only insignificantly (10–15%) inferior to oxidation by nitrobenzene in terms of yield and selectivity in vanillin and syringaldehyde. Very high consumption of oxygen (and consequentially, of alkali) in the process—over 10 mol per mol of obtained vanillin—is highlighted as an unresolved and unexplored problem: scientific literature reveals almost no studies devoted to the possibilities of decreasing the consumption of oxygen and alkali. Different hypotheses about the mechanism of lignin oxidation into the aromatic aldehydes are discussed, and the mechanism comprising the steps of single-electron oxidation of phenolate anions, and ending with retroaldol reaction of a substituted coniferyl aldehyde was pointed out as the most convincing one. The possibility and development prospects of single-stage oxidative processing of wood into the aromatic aldehydes and cellulose are analyzed. PMID:29140301

  20. Silver-catalyzed synthesis of amides from amines and aldehydes

    Science.gov (United States)

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  1. Possible regulatory role of phenylalanine ammonia-lyase in the production of anthocyanins in asparagus (Asparagus officinalis L)

    NARCIS (Netherlands)

    Flores, F.B.; Oosterhaven, J.; Martinez-Madrid, M.C.; Romojaro, F.

    2005-01-01

    The regulatory role of phenylalanine ammonia-lyase (PAL) in the light-induced accumulation of anthocyanins in the epidermis of asparagus spears has been analysed. A correlation between the stimulation of PAL activity and the rise in total anthocyanin content has been observed. Light radiation

  2. Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer

    International Nuclear Information System (INIS)

    Kaspera, Rüdiger; Sahele, Tariku; Lakatos, Kyle; Totah, Rheem A.

    2012-01-01

    Highlights: ► Cytochrome P450BM-3 reduced aldehydes to alcohols efficiently (k cat ∼ 25 min −1 ). ► Reduction is a direct hydride transfer from R-NADP 2 H to the carbonyl moiety. ► P450 domain variants enhance reduction through potential allosteric/redox interactions. ► Novel reaction will have implications for metabolism of xenobiotics. -- Abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k cat of ∼25 min −1 was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP 2 H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP 2 H but not D 2 O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.

  3. Flavour release of aldehydes and diacetyl in oil/water systems

    DEFF Research Database (Denmark)

    Haahr, Anne-Mette; Bredie, W. L. P.; Stahnke, Louise Heller

    2000-01-01

    from the pure oil. The release over time for diacetyl and (E,E)-2,4-hexadienal showed a linear relationship in all systems. The other compounds followed an exponential relationship between the time and the fraction released in the aqueous systems. It was demonstrated that the release of the volatile...... compounds was dependent on the chain length, the degree of unsaturation as well as the characteristics of the model system. (C) 2000 Elsevier Science Ltd. All rights reserved.......The concentration- and time-dependent release of three C-6-aldehydes, six C-9-aldehydes and diacetyl was studied in model systems. The systems were water, rapeseed oil and oil-in-water emulsions. Dynamic headspace sampling was used to collect the volatile compounds. In the concentration...

  4. An Improved Protocol for the Aldehyde Olefination Reaction Using (bmim ( as Reaction Medium

    Directory of Open Access Journals (Sweden)

    Vivek Srivastava

    2013-01-01

    Full Text Available [Ru(CODCl2]/CuCl2·2H2O/LiCl catalytic system works efficiently in ionic liquid media for aldehyde olefination reaction. It offers good yield and selectivity with the added advantage of 5 times recyclability for [Ru(CODCl2] /CuCl2·2H2O/LiCl catalytic system. We also successfully reduced the reaction time from 12 hours to 9 hours for the aldehyde olefination reaction.

  5. Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein ...

    African Journals Online (AJOL)

    Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein Expression Defines the Proliferative Nature of Cervical Cancer Stem Cells. ... of cervical cancer stem cells and also to validate them in initial and advanced stages of cervical cancer. Keywords: Cervical cancer, ALDH1, BALB/c-nu/nu, HeLa cells, RKIP, Sox2 ...

  6. Cooperative functioning between phenylalanine ammonia lyase and isochorishmate synthase activities contributes to salicylic acid biosynthesis in soybean

    Science.gov (United States)

    Salicylic acid (SA), an essential regulator of plant defense, is derived from chorismate via either the phenylalanine ammonia lyase (PAL), or the isochorishmate synthase (ICS) catalyzed steps. The ICS pathway is thought to be the primary contributor of defense-related SA, at least in Arabidopsis. We...

  7. Analysis of aldehydes in human exhaled breath condensates by in-tube SPME-HPLC.

    Science.gov (United States)

    Wang, ShuLing; Hu, Sheng; Xu, Hui

    2015-11-05

    In this paper, polypyrrole/graphene (PPy/G) composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless steel (SS) tube. Based on the coating tube, a novel online in-tube solid-phase microextraction -high performance liquid chromatography (IT-SPME-HPLC) was developed and applied for the extraction of aldehydes in the human exhaled breath condensates (EBC). The hybrid PPy/G nanocomposite exhibits remarkable chemical and mechanical stability, high selectivity, and satisfactory extraction performance toward aldehyde compounds. Moreover, the proposed online IT-SPME-HPLC method possesses numerous superiorities, such as time and cost saving, process simplicity, high precision and sensitivity. Some parameters related to extraction efficiency were optimized systematically. Under the optimal conditions, the recoveries of the aldehyde compounds at three spiked concentration levels varied in the range of 85%-117%. Good linearity was obtained with excellent correlation coefficients (R(2)) being larger than 0.994. The relative standard deviations (n = 5) of the method ranged from 1.8% to 11.3% and the limits of detection were between 2.3 and 3.3 nmol L(-1). The successful application of the proposed method in human EBC indicated that it is a promising approach for the determination of trace aldehyde metabolites in complex EBC samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Insight into Coenzyme A cofactor binding and the mechanism of acyl-transfer in an acylating aldehyde dehydrogenase from Clostridium phytofermentans.

    Science.gov (United States)

    Tuck, Laura R; Altenbach, Kirsten; Ang, Thiau Fu; Crawshaw, Adam D; Campopiano, Dominic J; Clarke, David J; Marles-Wright, Jon

    2016-02-22

    The breakdown of fucose and rhamnose released from plant cell walls by the cellulolytic soil bacterium Clostridium phytofermentans produces toxic aldehyde intermediates. To enable growth on these carbon sources, the pathway for the breakdown of fucose and rhamnose is encapsulated within a bacterial microcompartment (BMC). These proteinaceous organelles sequester the toxic aldehyde intermediates and allow the efficient action of acylating aldehyde dehydrogenase enzymes to produce an acyl-CoA that is ultimately used in substrate-level phosphorylation to produce ATP. Here we analyse the kinetics of the aldehyde dehydrogenase enzyme from the fucose/rhamnose utilisation BMC with different short-chain fatty aldehydes and show that it has activity against substrates with up to six carbon atoms, with optimal activity against propionaldehyde. We have also determined the X-ray crystal structure of this enzyme in complex with CoA and show that the adenine nucleotide of this cofactor is bound in a distinct pocket to the same group in NAD(+). This work is the first report of the structure of CoA bound to an aldehyde dehydrogenase enzyme and our crystallographic model provides important insight into the differences within the active site that distinguish the acylating from non-acylating aldehyde dehydrogenase enzymes.

  9. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

  10. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    International Nuclear Information System (INIS)

    Taylor, Rebecca L.; Caldwell, Gary S.; Bentley, Matthew G.

    2005-01-01

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD 50 values of 7 and 20 μM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 μM of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD 50 of decadienal by approximately a third for both species. 1 μM of copper chloride in solutions of decadienal reduced the 24 h LD 50 of decadienal to A. salina nauplii by approximately 11% and 1 μM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 μM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed

  11. Aldehydes react with scribed silicon to form alkyl monolayers Characterization by ToF-SIMS suggests an even-odd effect

    International Nuclear Information System (INIS)

    Lua, Y.-Y.; Fillmore, W. Jonathan J.; Linford, Matthew R.

    2004-01-01

    Alkyl monolayers are formed when silicon is chemomechanically scribed in the presence of aldehydes (from butanal to nonanal). X-ray photoelectron spectroscopy (XPS), wetting, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) suggest increasingly thick and hydrophobic monolayers with increasing aldehyde chain length. Superimposed on the general trend of stronger ToF-SIMS signals for hydrocarbon fragments from longer aldehyde precursors is an even-odd effect. This effect is most pronounced for smaller (one- and two-carbon) hydrocarbon fragments and for monolayers prepared with shorter aldehyde precursors. This is the first time than an even-odd effect has been demonstrated for monolayers on scribed silicon

  12. Aldehydes react with scribed silicon to form alkyl monolayers Characterization by ToF-SIMS suggests an even-odd effect

    Energy Technology Data Exchange (ETDEWEB)

    Lua, Y.-Y.; Fillmore, W. Jonathan J.; Linford, Matthew R

    2004-06-15

    Alkyl monolayers are formed when silicon is chemomechanically scribed in the presence of aldehydes (from butanal to nonanal). X-ray photoelectron spectroscopy (XPS), wetting, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) suggest increasingly thick and hydrophobic monolayers with increasing aldehyde chain length. Superimposed on the general trend of stronger ToF-SIMS signals for hydrocarbon fragments from longer aldehyde precursors is an even-odd effect. This effect is most pronounced for smaller (one- and two-carbon) hydrocarbon fragments and for monolayers prepared with shorter aldehyde precursors. This is the first time than an even-odd effect has been demonstrated for monolayers on scribed silicon.

  13. A new method for the chemoselective reduction of aldehydes and ...

    Indian Academy of Sciences (India)

    Department of Chemistry, Akdeniz University, 07058, Antalya, Turkey e-mail: ... Kinetics of reduction of aldehydes and ketones to corresponding alcohols were also examined and .... hol and unreducted ketone remain in organic phase. The.

  14. The Intramolecular Diels–Alder Reaction of Tryptamine-Derived Zincke Aldehydes Is a Stepwise Process

    OpenAIRE

    Pham, Hung V.; Martin, David B. C.; Vanderwal, Christopher D.; Houk, K. N.

    2012-01-01

    Computational studies show that the base-mediated intramolecular Diels–Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic import...

  15. Increased protein expression of LHCG receptor and 17a-hydroxylase/17,20-lyase in human polycystic ovaries

    NARCIS (Netherlands)

    Comim, F.V.; Teerds, K.J.; Hardy, K.; Franks, S.

    2013-01-01

    STUDY QUESTION Does the expression of LHCG receptor (LHCGR) protein and key enzymes in the androgen biosynthetic pathway differ in normal human versus polycystic ovarian tissue? SUMMARY ANSWER LHCGR and 17a-hydroxylase/17-20-lyase (CYP17A1) protein levels are increased in polycystic ovaries (PCOs).

  16. Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kaspera, Ruediger; Sahele, Tariku; Lakatos, Kyle [Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195-7610 (United States); Totah, Rheem A., E-mail: rtotah@u.washington.edu [Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195-7610 (United States)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Cytochrome P450BM-3 reduced aldehydes to alcohols efficiently (k{sub cat} {approx} 25 min{sup -1}). Black-Right-Pointing-Pointer Reduction is a direct hydride transfer from R-NADP{sup 2}H to the carbonyl moiety. Black-Right-Pointing-Pointer P450 domain variants enhance reduction through potential allosteric/redox interactions. Black-Right-Pointing-Pointer Novel reaction will have implications for metabolism of xenobiotics. -- Abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k{sub cat} of {approx}25 min{sup -1} was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP{sup 2}H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP{sup 2}H but not D{sub 2}O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.

  17. Catalytic Oxidation of Lignins into the Aromatic Aldehydes: General Process Trends and Development Prospects

    Directory of Open Access Journals (Sweden)

    Valery E. Tarabanko

    2017-11-01

    Full Text Available This review discusses principal patterns that govern the processes of lignins’ catalytic oxidation into vanillin (3-methoxy-4-hydroxybenzaldehyde and syringaldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde. It examines the influence of lignin and oxidant nature, temperature, mass transfer, and of other factors on the yield of the aldehydes and the process selectivity. The review reveals that properly organized processes of catalytic oxidation of various lignins are only insignificantly (10–15% inferior to oxidation by nitrobenzene in terms of yield and selectivity in vanillin and syringaldehyde. Very high consumption of oxygen (and consequentially, of alkali in the process—over 10 mol per mol of obtained vanillin—is highlighted as an unresolved and unexplored problem: scientific literature reveals almost no studies devoted to the possibilities of decreasing the consumption of oxygen and alkali. Different hypotheses about the mechanism of lignin oxidation into the aromatic aldehydes are discussed, and the mechanism comprising the steps of single-electron oxidation of phenolate anions, and ending with retroaldol reaction of a substituted coniferyl aldehyde was pointed out as the most convincing one. The possibility and development prospects of single-stage oxidative processing of wood into the aromatic aldehydes and cellulose are analyzed.

  18. Renal cysteine conjugate C-S lyase mediated toxicity of halogenated alkenes in primary cultures of human and rat proximal tubular cells.

    Science.gov (United States)

    McGoldrick, Trevor A; Lock, Edward A; Rodilla, Vicente; Hawksworth, Gabrielle M

    2003-07-01

    Proximal tubular cells from human (HPT) and rat (RPT) kidneys were isolated, grown to confluence and incubated with S-(1,2-dichlorovinyl)- l-cysteine (DCVC), S-(1,2,2-trichlorovinyl)- l-cysteine (TCVC), S-(1,1,2,2-tetrafluoroethyl)- l-cysteine (TFEC) and S-(2-chloro-1,1-difluorethyl)- l-cysteine (CDFEC), the cysteine conjugates of nephrotoxicants. The cultures were exposed to the conjugates for 12, 24 and 48 h and the toxicity determined using the MTT assay. All four conjugates caused dose-dependent toxicity to RPT cells over the range 50-1,000 microM, the order of toxicity being DCVC>TCVC>TFEC=CDFEC. The inclusion of aminooxyacetic acid (AOAA; 250 microM), an inhibitor of pyridoxal phosphate-dependent enzymes such as C-S lyase, afforded protection, indicating that C-S lyase has a role in the bioactivation of these conjugates. In HPT cultures only DCVC caused significant time- and dose-dependent toxicity. Exposure to DCVC (500 microM) for 48 h decreased cell viability to 7% of control cell values, whereas co-incubation of DCVC (500 microM) with AOAA (250 microM) resulted in cell viability of 71%. Human cultures were also exposed to S-(1,2-dichlorovinyl)-glutathione (DCVG). DCVG was toxic to HPT cells, but the onset of toxicity was delayed compared with the corresponding cysteine conjugate. AOAA afforded almost complete protection from DCVG toxicity. Acivicin (250 microM), an inhibitor of gamma-glutamyl transferase (gamma-GT), partially protected against DCVG (500 microM)-induced toxicity at 48 h (5% viability and 53% viability in the absence and presence of acivicin, respectively). These results suggest that DCVG requires processing by gamma-GT prior to bioactivation by C-S lyase in HPT cells. The activity of C-S lyase, using TFEC as a substrate, and glutamine transaminase K (GTK) was measured in rat and human cells with time in culture. C-S lyase activity in RPT and HPT cells decreased to approximately 30% of fresh cell values by the time the cells reached

  19. Abundance and genetic diversity of microbial polygalacturonase and pectate lyase in the sheep rumen ecosystem.

    Directory of Open Access Journals (Sweden)

    Peng Yuan

    Full Text Available Efficient degradation of pectin in the rumen is necessary for plant-based feed utilization. The objective of this study was to characterize the diversity, abundance, and functions of pectinases from microorganisms in the sheep rumen.A total of 103 unique fragments of polygalacturonase (PF00295 and pectate lyase (PF00544 and PF09492 genes were retrieved from microbial DNA in the rumen of a Small Tail Han sheep, and 66% of the sequences of these fragments had low identities (<65% with known sequences. Phylogenetic tree building separated the PF00295, PF00544, and PF09492 sequences into five, three, and three clades, respectively. Cellulolytic and noncellulolytic Butyrivibrio, Prevotella, and Fibrobacter species were the major sources of the pectinases. The two most abundant pectate lyase genes were cloned, and their protein products, expressed in Escherichia coli, were characterized. Both enzymes probably act extracellularly as their nucleotide sequences contained signal sequences, and they had optimal activities at the ruminal physiological temperature and complementary pH-dependent activity profiles.This study reveals the specificity, diversity, and abundance of pectinases in the rumen ecosystem and provides two additional ruminal pectinases for potential industrial use under physiological conditions.

  20. The Reduction of Nitriles to Aldehydes: Applications of Raney Nickel ...

    African Journals Online (AJOL)

    NJD

    The selective reduction of a nitrile to an aldehyde, especially when the substrate ..... prelude to reductive amination chemistry was thwarted by a rapid aldol ... and allowed the direct incorporation of the α-methylbenzylamine chiral auxiliary.

  1. OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES

    Energy Technology Data Exchange (ETDEWEB)

    Byrn, Marianne; Calvin, Melvin

    1965-12-01

    Using infra-red spectroscopy, the equilibrium exchange times have been determined for a series of ketones, aromatic aldehydes, and {beta}-ketoesters reacting with oxygen 18 enriched water. These exchange times have been evaluated in terms of steric and electronic considerations, and applied to a discussion of the exchange times of chlorophylls a and b and chlorophyll derivatives.

  2. Abscisic (ABA)-aldehyde is a precursor to, and 1',4'-trans-ABA-diol a catabolite of, ABA in apple

    International Nuclear Information System (INIS)

    Rock, C.D.; Zeevaart, J.A.D.

    1990-01-01

    Previous 18 O labeling studies of abscisic acid (ABA) have shown that apple (Malus domestica Borkh. cv Granny Smith) fruits synthesize a majority of [ 18 O]ABA with the label incorporated in the 1'-hydroxyl position and unlabeled in the carboxyl group (JAD Zeevaart, TG Heath, DA Gage [1989] Plant Physiol 91: 1594-1601). It was proposed that exchange of 18 O in the side chain with the medium occurred at an aldehyde intermediate stage of ABA biosynthesis. We have isolated ABA-aldehyde and 1'-4'-trans-ABA-diol (ABA-trans-diol) from 18 O-labeled apple fruit tissue and measured the extent and position of 18 O incorporation by tandem mass spectrometry. 18 O-Labeling patterns of ABA-aldehyde, ABA-trans-diol, and ABA indicate that ABA-aldehyde is a precursor to, and ABA-trans-diol a catabolite of, ABA. Exchange of 18 O in the carbonyl of ABA-aldehyde can be the cause of loss of 18 O from the side chain of [ 18 O]ABA. Results of feeding experiments with deuterated substrates provide further support for the precursor-product relationship of ABA-aldehyde → ABA → ABA-trans-diol. The ABA-aldehyde and ABA-trans-diol contents of fruits and leaves were low, approximately 1 and 0.02 nanograms per gram fresh weight for ABA-aldehyde and ABA-trans-diol, respectively, while ABA levels in fruits ranged from 10 to 200 nanograms per gram fresh weight. ABA biosynthesis was about 10-fold lower in fruits than in leaves. In fruits, the majority of ABA was conjugated to β-D-glucopyranosyl abscisate, whereas in leaves ABA was mainly hydroxylated to phaseic acid. Parallel pathways for ABA and trans-ABA biosynthesis and conjugation in fruits and leaves are proposed

  3. Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kjell-Tore

    1996-08-01

    Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

  4. Kinetic mechanism of an aldehyde reductase of Saccharomyces cerevisiae that relieves toxicity of furfural and 5-hydroxymethylfurfural

    Science.gov (United States)

    An effective means of relieving the toxicity of furan aldehydes, furfural (FFA) and 5-hydroxymethylfurfural (HMF), on fermenting organisms is essential for achieving efficient fermentation of lignocellulosic biomass to ethanol and other products. Ari1p, an aldehyde reductase from Saccharomyces cerev...

  5. Peptide aldehyde inhibitors of bacterial peptide deformylases.

    Science.gov (United States)

    Durand, D J; Gordon Green, B; O'Connell, J F; Grant, S K

    1999-07-15

    Bacterial peptide deformylases (PDF, EC 3.5.1.27) are metalloenzymes that cleave the N-formyl groups from N-blocked methionine polypeptides. Peptide aldehydes containing a methional or norleucinal inhibited recombinant peptide deformylase from gram-negative Escherichia coli and gram-positive Bacillus subtilis. The most potent inhibitor was calpeptin, N-CBZ-Leu-norleucinal, which was a competitive inhibitor of the zinc-containing metalloenzymes, E. coli and B. subtilis PDF with Ki values of 26.0 and 55.6 microM, respectively. Cobalt-substituted E. coli and B. subtilis deformylases were also inhibited by these aldehydes with Ki values for calpeptin of 9.5 and 12.4 microM, respectively. Distinct spectral changes were observed upon binding of calpeptin to the Co(II)-deformylases, consistent with the noncovalent binding of the inhibitor rather than the formation of a covalent complex. In contrast, the chelator 1,10-phenanthroline caused the time-dependent inhibition of B. subtilis Co(II)-PDF activity with the loss of the active site metal. The fact that calpeptin was nearly equipotent against deformylases from both gram-negative and gram-positive bacterial sources lends further support to the idea that a single deformylase inhibitor might have broad-spectrum antibacterial activity. Copyright 1999 Academic Press.

  6. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    Science.gov (United States)

    Gong, J. C.; Zhu, T.; Hu, M.; Zhang, L. W.; Cheng, H.; Zhang, L.; Tong, J.; Zhang, J.

    2010-08-01

    Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

  7. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Tomofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135 (Japan); Ichinose, Hirofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Wariishi, Hiroyuki, E-mail: hirowari@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Innovation Center for Medical Redox Navigation, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

    2010-04-09

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  8. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Nakamura, Tomofumi; Ichinose, Hirofumi; Wariishi, Hiroyuki

    2010-01-01

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD + -binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  9. Homogeneous catalytic hydrogenation of bio-oil and related model aldehydes with RuCl{sub 2}(PPh{sub 3}){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Li, W.; Lu, Q.; Zhu, X. [Anhui Province Key Laboratory of Biomass Clean Energy, University of Science and Technology of China, Hefei (China)

    2010-12-15

    A homogeneous RuCl{sub 2}(PPh{sub 3}){sub 3} catalyst was prepared for the hydrogenation of bio-oil to improve its stability and fuel quality. Experiments were first performed on three model aldehydes of acetaldehyde, furfural and vanillin selected to represent the linear aldehydes, oxygen heterocyclic aldehydes and aromatic aldehydes in bio-oil. The results demonstrated the high hydrogenation capability of this homogeneous catalyst under mild conditions (55-90 C, 1.3-3.3 MPa). The highest conversion of the three model aldehydes was over 90 %. Furfural and acetaldehyde were singly converted to furfuryl alcohol and ethanol after hydrogenation, while vanillin was mainly converted to vanillin alcohol, together with a small amount of 2-methoxy-4-methylphenol and 2-methoxyphenol. Further experiments were conducted on a bio-oil fraction extracted by ethyl acetate and on the whole bio-oil at 70 C and 3.3 MPa. Most of the aldehydes were transformed to the corresponding alcohols, and some ketones and compounds with C-C double bond were converted to more stable compounds. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Exposure to mutagenic aldehydes and particulate matter during panfrying of beefsteak with margarine, rapeseed oil, olive oil or soybean oil.

    Science.gov (United States)

    Sjaastad, Ann Kristin; Svendsen, Kristin

    2008-11-01

    The aim of the study was to see if a cook could be exposed to mutagenic aldehydes in fumes from frying of beefsteak using margarine, rapeseed oil, soybean oil or virgin olive oil as frying fat. In addition, levels of particle exposure were measured to make the results comparable to other studies. The levels of higher aldehydes and total particles were measured in the breathing zone of the cook during the panfrying of beefsteak with the four different frying fats. In addition, the number of particles in the size intervals 0.3-0.5, 0.5-0.7 and 0.7-1.0 microm in the kitchen was registered. Measured levels of mutagenic aldehydes were between non-detectable and 25.33 microg m(-3) air. The exposure level of total aerosol was between 1.0 and 11.6 mg m(-3). Higher aldehydes were detected in all samples from this study, and mutagenic aldehydes were detected in most of the samples. Frying with margarine gave statistically significantly higher levels of mutagenic aldehydes and particles in all three size fractions than frying with the three different kinds of oil.

  11. Plant volatile aldehydes as natural insecticides against stored-product beetles.

    Science.gov (United States)

    Hubert, Jan; Münzbergová, Zuzana; Santino, Angelo

    2008-01-01

    Infestation by stored-product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six-carbon and nine-carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored-product beetles in feeding, fumigation and combined bioassays. The compounds (2E,6Z)-nonadienal, (2E)-nonenal and (2E)-hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)-hexenal in fumigation tests, with the LC(50) ranging from 4 to 26 mg L(-1), while (2E, 6Z)-nonadienal was the most effective in feeding tests, giving LD(50)s ranging from 0.44 to 2.76 mg g(-1) when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)-hexenal was the most effective compound, with a calculated LC(99) ranging from 33 to 166 mg L(-1). The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored-product beetles.

  12. The anaerobic chytridiomycete fungus Piromyces sp. E2 produces ethanol via pyruvate:formate lyase and an alcohol dehydrogenase E.

    NARCIS (Netherlands)

    Boxma, B.; Voncken, F.L.M.; Jannink, S.A.; Alen, T.A. van; Akhmanova, A.S.; Weelden, S.W. van; Hellemond, J.J. van; Ricard, G.N.S.; Huynen, M.A.; Tielens, A.G.; Hackstein, J.H.P.

    2004-01-01

    Anaerobic chytridiomycete fungi possess hydrogenosomes, which generate hydrogen and ATP, but also acetate and formate as end-products of a prokaryotic-type mixed-acid fermentation. Notably, the anaerobic chytrids Piromyces and Neocallimastix use pyruvate:formate lyase (PFL) for the catabolism of

  13. Copper(II)/amine synergistically catalyzed enantioselective alkylation of cyclic N-acyl hemiaminals with aldehydes.

    Science.gov (United States)

    Sun, Shutao; Mao, Ying; Lou, Hongxiang; Liu, Lei

    2015-07-07

    The first catalytic asymmetric alkylation of N-acyl quinoliniums with aldehydes has been described. A copper/amine synergistic catalytic system has been developed, allowing the addition of functionalized aldehydes to a wide range of electronically varied N-acyl quinoliniums in good yields with excellent enantiocontrol. The synergistic catalytic system was also effective for N-acyl dihydroisoquinoliniums and β-caboliniums, demonstrating the general applicability of the protocol in the enantioselective alkylation of diverse cyclic N-acyl hemiaminals.

  14. Changes in nonpolar aldehydes in bean cotyledons during ageing

    Czech Academy of Sciences Publication Activity Database

    Wilhelmová, Naděžda; Domingues, P.; Srbová, M.; Fuksová, H.; Wilhelm, J.

    2006-01-01

    Roč. 50, č. 4 (2006), s. 559-564 ISSN 0006-3134 R&D Projects: GA ČR GA522/03/0312 Institutional research plan: CEZ:AV0Z50380511 Keywords : Ageing * aldehydes * lipid peroxidation * lipofuscin-like pigments (LFP) Subject RIV: CE - Biochemistry Impact factor: 1.198, year: 2006

  15. Effects of light and copper ions on volatile aldehydes of milk and milk fractions

    Energy Technology Data Exchange (ETDEWEB)

    Jeno, W.; Bassette, R.; Crang, R.E.

    1988-09-01

    Raw, laboratory-pasteurized and plant-pasteurized homogenized milks were exposed to copper ions (5 ppm), to sunlight or fluorescent light and the effects determined on the composition of volatile aldehydes. The greatest change due to copper treatment was an increase in n-hexanal; acetaldehyde showed the least response in each of the sources of milk. The responses were similar from all three sources of milk with laboratory-pasteurized milk samples showing the greatest responses for each aldehyde analyzed. Similar milk samples exposed to sunlight also showed an increase in volatile aldehydes from all milk sources but with the greatest response being acetaldehyde and n-pentanal components. The milk fraction most susceptible to changes in the presence of light was neutralized whey, whereas resuspended cream was most susceptible to copper exposure. Overall, dialyzed whey appeared to be influenced more than other milk fractions by both light and copper ions.

  16. Role and structural characterization of plant aldehyde dehydrogenases from family 2 and family 7.

    Science.gov (United States)

    Končitíková, Radka; Vigouroux, Armelle; Kopečná, Martina; Andree, Tomáš; Bartoš, Jan; Šebela, Marek; Moréra, Solange; Kopečný, David

    2015-05-15

    Aldehyde dehydrogenases (ALDHs) are responsible for oxidation of biogenic aldehyde intermediates as well as for cell detoxification of aldehydes generated during lipid peroxidation. So far, 13 ALDH families have been described in plants. In the present study, we provide a detailed biochemical characterization of plant ALDH2 and ALDH7 families by analysing maize and pea ALDH7 (ZmALDH7 and PsALDH7) and four maize cytosolic ALDH(cALDH)2 isoforms RF2C, RF2D, RF2E and RF2F [the first maize ALDH2 was discovered as a fertility restorer (RF2A)]. We report the crystal structures of ZmALDH7, RF2C and RF2F at high resolution. The ZmALDH7 structure shows that the three conserved residues Glu(120), Arg(300) and Thr(302) in the ALDH7 family are located in the substrate-binding site and are specific to this family. Our kinetic analysis demonstrates that α-aminoadipic semialdehyde, a lysine catabolism intermediate, is the preferred substrate for plant ALDH7. In contrast, aromatic aldehydes including benzaldehyde, anisaldehyde, cinnamaldehyde, coniferaldehyde and sinapaldehyde are the best substrates for cALDH2. In line with these results, the crystal structures of RF2C and RF2F reveal that their substrate-binding sites are similar and are formed by an aromatic cluster mainly composed of phenylalanine residues and several nonpolar residues. Gene expression studies indicate that the RF2C gene, which is strongly expressed in all organs, appears essential, suggesting that the crucial role of the enzyme would certainly be linked to the cell wall formation using aldehydes from phenylpropanoid pathway as substrates. Finally, plant ALDH7 may significantly contribute to osmoprotection because it oxidizes several aminoaldehydes leading to products known as osmolytes.

  17. Identification, expression, and characterization of a novel bacterial RGI Lyase enzyme for the production of bio-functional fibers

    DEFF Research Database (Denmark)

    da Silva, Ines Isabel Cardoso Rodrigues; Larsen, Dorte Møller; Meyer, Anne S.

    2011-01-01

    A gene encoding a putative rhamnogalacturonan I (RGI) Lyase (EC 4.2.2.-) from Bacillus licheniformis (DSM13) was selected after a homology search and phylogenetic analysis and optimized with respect to codon usage. The designed gene was transformed into Pichia pastoris and the enzyme was produced...

  18. The ORF slr0091 of Synechocystis sp. PCC6803 encodes a high-light induced aldehyde dehydrogenase converting apocarotenals and alkanals

    KAUST Repository

    Trautmann, Danika

    2013-07-05

    Oxidative cleavage of carotenoids and peroxidation of lipids lead to apocarotenals and aliphatic aldehydes called alkanals, which react with vitally important compounds, promoting cytotoxicity. Although many enzymes have been reported to deactivate alkanals by converting them into fatty acids, little is known about the mechanisms used to detoxify apocarotenals or the enzymes acting on them. Cyanobacteria and other photosynthetic organisms must cope with both classes of aldehydes. Here we report that the Synechocystis enzyme SynAlh1, encoded by the ORF slr0091, is an aldehyde dehydrogenase that mediates oxidation of both apocarotenals and alkanals into the corresponding acids. Using a crude lysate of SynAlh1-expressing Escherichia coli cells, we show that SynAlh1 converts a wide range of apocarotenals and alkanals, with a preference for apocarotenals with defined chain lengths. As suggested by in vitro incubations and using engineered retinal-forming E. coli cells, we found that retinal is not a substrate for SynAlh1, making involvement in Synechocystis retinoid metabolism unlikely. The transcript level of SynAlh1 is induced by high light and cold treatment, indicating a role in the stress response, and the corresponding gene is a constituent of a stress-related operon. The assumptions regarding the function of SynAlh are further supported by the surprisingly high homology to human and plant aldehyde dehydrogenase that have been assigned to aldehyde detoxification. SynAlh1 is the first aldehyde dehydrogenase that has been shown to form both apocarotenoic and fatty acids. This dual function suggests that its eukaryotic homologs may also be involved in apocarotenal metabolism, a function that has not been considered so far. Aldehyde dehydrogenases play an important role in detoxification of reactive aldehydes. Here, we report on a cyanbacterial enzyme capable in converting two classes of lipid-derived aldehydes, apocaotenals and alkanals. The corresponding gene is a

  19. Structural Insights Into The Bacterial Carbon-Phosphorus Lyase Machinery

    DEFF Research Database (Denmark)

    Brodersen, Ditlev Egeskov

    the proteins encoded in the phn operon act in concert to catabolise phosphonate remain unknown. We have determined the crystal structure of a 240 kDa Escherichia coli carbon-phosphorus lyase core complex at 1.7 Å and show that it comprises a highly intertwined network of subunits with several unexpected......Phosphonate compounds act as a nutrient source for some microorganisms when phosphate is limiting but require a specialised enzymatic machinery due to the presence of the highly stable carbon-phosphorus bond. Despite the fundamental importance to microbial metabolism, the details of how...... structural features. The complex contains at least two different active sites and suggest a revision of current models of carbon-phosphorus bond cleavage. Using electron microscopy, we map the binding site of an additional protein subunit, which may use ATP for driving conformational changes during...

  20. Contribution to the study of carbohydrate radiolysis: study of the formation of malonic aldehyde during gamma irradiation of glucose

    International Nuclear Information System (INIS)

    Enrico, Gerard.

    1974-01-01

    It was shown that malonic aldehyde can be formed directly by radiation of dry glucose or through the radicals of water when the latter is present. The direct effect leads to a malonic aldehyde production proportional to the dose and independent of dose rate, temperature over a wide range, presence of oxygen and crystalline state of the glucose, but strongly dependent on the water content and anomeric form of the glucose. Isotopic labelling showed that both ends of the glucose molecule participate in the malonic aldehyde formation. Extrapolation to linear polymers (maltose, maltotriose) reveals the independence of the radiolysis yield with regard to the α 1-4 bond and suggests that it tends towards that of glucose in amylose. The indirect effect is linked with the action of the OH radicals of water and appears when glucose is irradiated in a sufficiently hydrated state or in solution. In the latter case the malonic aldehyde concentration is largely independent of the glucose concentration and is not proportional to the dose. Oxygen has little effect but a strong activation is observed at high pH. The use of 14 C showed that the aldehyde end of glucose is responsible for most of the malonic aldehyde. Polymerisation of the glucose by α 1-4 binding reduces the radiolytic yield. The indirect effect would thus be negligible in amylose [fr

  1. Five phosphonate operon gene products as components of a multi-subunit complex of the carbon-phosphorus lyase pathway

    DEFF Research Database (Denmark)

    Jochimsen, Bjarne; Lolle, Signe; McSorley, Fern R.

    2011-01-01

    Organophosphonate utilization by Escherichia coli requires the 14 cistrons of the phnCDEFGHIJKLMNOP operon, of which the carbon-phosphorus lyase has been postulated to consist of the seven polypeptides specified by phnG to phnM. A 5,660-bp DNA fragment encompassing phnGHIJKLM is cloned, followed...

  2. Volatile aldehydes are promising broad-spectrum postharvest insecticides.

    Science.gov (United States)

    Hammond, D G; Rangel, S; Kubo, I

    2000-09-01

    A variety of naturally occurring aldehydes common in plants have been evaluated for their insecticidal activity and for phytotoxicity to postharvest fruits, vegetables, and grains. Twenty-nine compounds were initially screened for their activity against aphids on fava bean leaf disks. Application under reduced pressure (partial vacuum) for the first quarter of fumigation increased insecticidal activity severalfold. The 11 best aldehydes were assayed against aphids placed under the third leaf of whole heads of iceberg lettuce using the same two-tier reduced-pressure regime, which caused no additional detriment to the commodity over fumigation at atmospheric pressure. Phytotoxicity to naked and wrapped iceburg lettuce, green and red table grapes, lemon, grapefruit, orange, broccoli, avocado, cabbage, pinto bean, and rice at doses that killed 100% of aphids was recorded for three promising fumigants: propanal, (E)-2-pentenal, and 2-methyl-(E)-2-butenal. These three compounds have excellent potential as affordable postharvest insect control agents, killing 100% of the aphids with little or no detectable harm to a majority of the commodities tested. Preliminary assays indicate that similar doses are also effective against mealybugs, thrips, and whitefly.

  3. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae.

    Science.gov (United States)

    Moon, Jaewoong; Liu, Z Lewis

    2015-04-01

    The aldehyde reductase gene ARI1 is a recently characterized member of an intermediate subfamily within the short-chain dehydrogenase/reductase (SDR) superfamily that clarified mechanisms of in situ detoxification of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde by Saccharomyces cerevisiae. Uncharacterized open reading frames (ORFs) are common among tolerant candidate genes identified for lignocellulose-to-advanced biofuels conversion. This study presents partially purified proteins of two ORFs, YDR541C and YGL039W, and direct enzyme assay evidence against aldehyde-inhibitory compounds commonly encountered during lignocellulosic biomass fermentation processes. Each of the partially purified proteins encoded by these ORFs showed a molecular mass of approximately 38 kDa, similar to Ari1p, a protein encoded by aldehyde reductase gene. Both proteins demonstrated strong aldehyde reduction activities toward 14 aldehyde substrates, with high levels of reduction activity for Ydr541cp toward both aromatic and aliphatic aldehydes. While Ydr541cp was observed to have a significantly higher specific enzyme activity at 20 U/mg using co-factor NADPH, Ygl039wp displayed a NADH preference at 25 U/mg in reduction of butylaldehyde. Amino acid sequence analysis identified a characteristic catalytic triad, Ser, Tyr and Lys; a conserved catalytic motif of Tyr-X-X-X-Lys; and a cofactor-binding sequence motif, Gly-X-X-Gly-X-X-Ala, near the N-terminus that are shared by Ydr541cp, Ygl039wp, Yol151wp/GRE2 and Ari1p. Findings of aldehyde reductase genes contribute to the yeast gene annotation and aids development of the next-generation biocatalyst for advanced biofuels production. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Exploration of swapping enzymatic function between two proteins: A simulation study of chorismate mutase and isochorismate pyruvate lyase

    Science.gov (United States)

    Choutko, Alexandra; Eichenberger, Andreas P; Gunsteren, Wilfred F; Dolenc, Jožica

    2013-01-01

    The enzyme chorismate mutase EcCM from Escherichia coli catalyzes one of the few pericyclic reactions in biology, the transformation of chorismate to prephenate. The isochorismate pyruvate lyase PchB from Pseudomonas aeroginosa catalyzes another pericyclic reaction, the isochorismate to salicylate transformation. Interestingly, PchB possesses weak chorismate mutase activity as well thus being able to catalyze two distinct pericyclic reactions in a single active site. EcCM and PchB possess very similar folds, despite their low sequence identity. Using molecular dynamics simulations of four combinations of the two enzymes (EcCM and PchB) with the two substrates (chorismate and isochorismate) we show that the electrostatic field due to EcCM at atoms of chorismate favors the chorismate to prephenate transition and that, analogously, the electrostatic field due to PchB at atoms of isochorismate favors the isochorismate to salicylate transition. The largest differences between EcCM and PchB in electrostatic field strengths at atoms of the substrates are found to be due to residue side chains at distances between 0.6 and 0.8 nm from particular substrate atoms. Both enzymes tend to bring their non-native substrate in the same conformation as their native substrate. EcCM and to a lower extent PchB fail in influencing the forces on and conformations of the substrate such as to favor the other chemical reaction (isochorismate pyruvate lyase activity for EcCM and chorismate mutase activity for PchB). These observations might explain the difficulty of engineering isochorismate pyruvate lyase activity in EcCM by solely mutating active site residues. PMID:23595942

  5. Exploration of swapping enzymatic function between two proteins: a simulation study of chorismate mutase and isochorismate pyruvate lyase.

    Science.gov (United States)

    Choutko, Alexandra; Eichenberger, Andreas P; van Gunsteren, Wilfred F; Dolenc, Jožica

    2013-06-01

    The enzyme chorismate mutase EcCM from Escherichia coli catalyzes one of the few pericyclic reactions in biology, the transformation of chorismate to prephenate. The isochorismate pyruvate lyase PchB from Pseudomonas aeroginosa catalyzes another pericyclic reaction, the isochorismate to salicylate transformation. Interestingly, PchB possesses weak chorismate mutase activity as well thus being able to catalyze two distinct pericyclic reactions in a single active site. EcCM and PchB possess very similar folds, despite their low sequence identity. Using molecular dynamics simulations of four combinations of the two enzymes (EcCM and PchB) with the two substrates (chorismate and isochorismate) we show that the electrostatic field due to EcCM at atoms of chorismate favors the chorismate to prephenate transition and that, analogously, the electrostatic field due to PchB at atoms of isochorismate favors the isochorismate to salicylate transition. The largest differences between EcCM and PchB in electrostatic field strengths at atoms of the substrates are found to be due to residue side chains at distances between 0.6 and 0.8 nm from particular substrate atoms. Both enzymes tend to bring their non-native substrate in the same conformation as their native substrate. EcCM and to a lower extent PchB fail in influencing the forces on and conformations of the substrate such as to favor the other chemical reaction (isochorismate pyruvate lyase activity for EcCM and chorismate mutase activity for PchB). These observations might explain the difficulty of engineering isochorismate pyruvate lyase activity in EcCM by solely mutating active site residues. © 2013 The Protein Society.

  6. Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum

    OpenAIRE

    Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

    2016-01-01

    Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from thes...

  7. Enhanced detection of aldehydes in Extra-Virgin Olive Oil by means of band selective NMR spectroscopy

    Science.gov (United States)

    Dugo, Giacomo; Rotondo, Archimede; Mallamace, Domenico; Cicero, Nicola; Salvo, Andrea; Rotondo, Enrico; Corsaro, Carmelo

    2015-02-01

    High resolution Nuclear Magnetic Resonance (NMR) spectroscopy is a very powerful tool for comprehensive food analyses and especially for Extra-Virgin Olive Oils (EVOOs). We use the NMR technique to study the spectral region of aldehydes (8-10 ppm) for EVOOs coming from the south part of Italy. We perform novel experiments by using mono and bidimensional band selective spin-echo pulse sequences and identify four structural classes of aldehydes in EVOOs. For the first time such species are identified in EVOOs without any chemical treatment; only dilution with CDCl3 is employed. This would allow the discrimination of different EVOOs for the aldehydes content increasing the potentiality of the NMR technique in the screening of metabolites for geographical characterization of EVOOs.

  8. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    Directory of Open Access Journals (Sweden)

    Sales F.G.

    2004-01-01

    Full Text Available In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM applied to the liquid phase.

  9. Copepod reproduction is unaffected by diatom aldehydes or lipid composition

    DEFF Research Database (Denmark)

    Dutz, Jörg; Koski, Marja; Jonasdottir, Sigrun

    2008-01-01

    We investigated whether reduced reproductive success of copepods fed with diatoms was related to nutritional imbalances with regard to essential lipids or to the production of inhibitory aldehydes. In 10-d laboratory experiments, feeding, egg production, egg hatching success, and fecal pellet...

  10. Utilization of Glyphosate as Phosphate Source: Biochemistry and Genetics of Bacterial Carbon-Phosphorus Lyase

    Science.gov (United States)

    Zechel, David L.; Jochimsen, Bjarne

    2014-01-01

    SUMMARY After several decades of use of glyphosate, the active ingredient in weed killers such as Roundup, in fields, forests, and gardens, the biochemical pathway of transformation of glyphosate phosphorus to a useful phosphorus source for microorganisms has been disclosed. Glyphosate is a member of a large group of chemicals, phosphonic acids or phosphonates, which are characterized by a carbon-phosphorus bond. This is in contrast to the general phosphorus compounds utilized and metabolized by microorganisms. Here phosphorus is found as phosphoric acid or phosphate ion, phosphoric acid esters, or phosphoric acid anhydrides. The latter compounds contain phosphorus that is bound only to oxygen. Hydrolytic, oxidative, and radical-based mechanisms for carbon-phosphorus bond cleavage have been described. This review deals with the radical-based mechanism employed by the carbon-phosphorus lyase of the carbon-phosphorus lyase pathway, which involves reactions for activation of phosphonate, carbon-phosphorus bond cleavage, and further chemical transformation before a useful phosphate ion is generated in a series of seven or eight enzyme-catalyzed reactions. The phn genes, encoding the enzymes for this pathway, are widespread among bacterial species. The processes are described with emphasis on glyphosate as a substrate. Additionally, the catabolism of glyphosate is intimately connected with that of aminomethylphosphonate, which is also treated in this review. Results of physiological and genetic analyses are combined with those of bioinformatics analyses. PMID:24600043

  11. Expression and properties of the highly alkalophilic phenylalanine ammonia-lyase of thermophilic Rubrobacter xylanophilus.

    Directory of Open Access Journals (Sweden)

    Klaudia Kovács

    Full Text Available The sequence of a phenylalanine ammonia-lyase (PAL; EC: 4.3.1.24 of the thermophilic and radiotolerant bacterium Rubrobacter xylanophilus (RxPAL was identified by screening the genomes of bacteria for members of the phenylalanine ammonia-lyase family. A synthetic gene encoding the RxPAL protein was cloned and overexpressed in Escherichia coli TOP 10 in a soluble form with an N-terminal His6-tag and the recombinant RxPAL protein was purified by Ni-NTA affinity chromatography. The activity assay of RxPAL with l-phenylalanine at various pH values exhibited a local maximum at pH 8.5 and a global maximum at pH 11.5. Circular dichroism (CD studies showed that RxPAL is associated with an extensive α-helical character (far UV CD and two distinctive near-UV CD peaks. These structural characteristics were well preserved up to pH 11.0. The extremely high pH optimum of RxPAL can be rationalized by a three-dimensional homology model indicating possible disulfide bridges, extensive salt-bridge formation and an excess of negative electrostatic potential on the surface. Due to these properties, RxPAL may be a candidate as biocatalyst in synthetic biotransformations leading to unnatural l- or d-amino acids or as therapeutic enzyme in treatment of phenylketonuria or leukemia.

  12. Evaluation of the hydroxynitrile lyase activity in cell cultures of capulin (Prunus serotina).

    Science.gov (United States)

    Hernández, Liliana; Luna, Héctor; Navarro-Ocaña, Arturo; Olivera-Flores, Ma Teresa de Jesús; Ayala, Ivon

    2008-07-01

    Enzymatic preparations obtained from young plants and cell cultures of capulin were screened for hydroxynitrile lyase activity. The three week old plants, grown under sterile conditions, were used to establish a solid cell culture. Crude preparations obtained from this plant material were evaluated for the transformation of benzaldehyde to the corresponding cyanohydrin (mandelonitrile). The results show that the crude material from roots, stalks, and leaves of young plants and calli of roots, stalks, internodes and petioles biocatalyzed the addition of hydrogen cyanide (HCN) to benzaldehyde with a modest to excellent enantioselectivity.

  13. Aldehyde dehydrogenase 2 in aplastic anemia, Fanconi anemia and hematopoietic stem cells.

    Science.gov (United States)

    Van Wassenhove, Lauren D; Mochly-Rosen, Daria; Weinberg, Kenneth I

    2016-09-01

    Maintenance of the hematopoietic stem cell (HSC) compartment depends on the ability to metabolize exogenously and endogenously generated toxins, and to repair cellular damage caused by such toxins. Reactive aldehydes have been demonstrated to cause specific genotoxic injury, namely DNA interstrand cross-links. Aldehyde dehydrogenase 2 (ALDH2) is a member of a 19 isoenzyme ALDH family with different substrate specificities, subcellular localization, and patterns of expression. ALDH2 is localized in mitochondria and is essential for the metabolism of acetaldehyde, thereby placing it directly downstream of ethanol metabolism. Deficiency in ALDH2 expression and function are caused by a single nucleotide substitution and resulting amino acid change, called ALDH2*2. This genetic polymorphism affects 35-45% of East Asians (about ~560 million people), and causes the well-known Asian flushing syndrome, which results in disulfiram-like reactions after ethanol consumption. Recently, the ALDH2*2 genotype has been found to be associated with marrow failure, with both an increased risk of sporadic aplastic anemia and more rapid progression of Fanconi anemia. This review discusses the unexpected interrelationship between aldehydes, ALDH2 and hematopoietic stem cell biology, and in particular its relationship to Fanconi anemia. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  14. The ketogenic diet is well tolerated and can be effective in patients with argininosuccinate lyase deficiency and refractory epilepsy

    NARCIS (Netherlands)

    Peuscher, Rosanne; Dijsselhof, Monique E.; Abeling, Nico G.; van Rijn, Margreet; van Spronsen, Francjan J.; Bosch, Annet M.

    2012-01-01

    Argininosuccinate lyase (ASL) deficiency (MIM 608310, McKusick 207900) is a rare disorder of the urea cycle, which leads to a deficiency of arginine and hyperammonemia. Epilepsy is a frequent complication of this disorder. A ketogenic diet (KD) can be a very effective therapy for refractory

  15. Atmospheric measurements of hydroperoxides and aldehydes during field campaigns : new results due to improvement of measurements techniques

    Science.gov (United States)

    François, S.; Sowka, I.; Poulain, L.; Monod, A.; Wortham, H.

    2003-04-01

    Hydroperoxides and aldehydes are considered as atmospheric reservoirs of OH, HO_2 and RO_2 radicals and can reflect the oxidizing levels of the atmosphere. They are considered as important gas phase photo-oxidants present in the atmosphere. However, the atmospheric role of these compounds can vary from one species to another, therefore it is essential to investigate their measurement and speciation in the atmosphere. Atmospheric measurements were realized during two different field campaigns in the Marseilles area (France). Hydroperoxides were trapped in aqueous phase, with a glass coil and analyzed by HPLC/fluorescence detector with post column derivatization. Aldehydes were trapped in a liquid phase containing 2-4 DNPH, with a mist chamber and analyzed by HPLC/UV. The analytical techniques provided individual separation and quantification of seven hydroperoxides (hydrogen peroxide, hydroxymethyl hydroperoxide, bis(hydroxymethyl) peroxide, 1-hydroxyethyl hydroperoxide, methyl hydroperoxide, ethyl hydroperoxide and peroxyacetic acid) and eleven volatile aldehydes (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, crotonaldehyde, butyraldehyde, benzaldehyde, glyoxal, valeraldehyde and methylglyoxal). The first field campaign was part of the ESCOMPTE project (June 4th to July 16th 2001). During this campaign five different sampling sites, at low altitudes (<= 285 m), were investigated (maritime, urban, sub-industrial, biogenic and rural sites) and atmospheric measurements were realized during photochemical air pollution events. The second field campaign was part of the BOND project (July 2nd to July 14th 2002). Atmospheric measurements of hydroperoxides were carried out on one biogenic site, at altitude 690 m. The measurement system was improved allowing online sampling and analysis. During these field campaigns collection efficiencies were better than 96% for hydroperoxides, and from 78% to 96% for aldehydes. Detection limits were between 7,3× 10-3

  16. Silica-Supported Catalyst for Enantioselective Arylation of Aldehydes under Batch and Continuous-Flow Conditions.

    Science.gov (United States)

    Watanabe, Satoshi; Nakaya, Naoyuki; Akai, Junichiro; Kanaori, Kenji; Harada, Toshiro

    2018-05-04

    A silica-supported 3-aryl H 8 -BINOL-derived titanium catalyst exhibited high performance in the enantioselective arylation of aromatic aldehydes using Grignard and organolithium reagents not only under batch conditions but also under continuous-flow conditions. Even with a simple pipet reactor packed with the heterogeneous catalyst, the enantioselective production of chiral diarylmethanols could be achieved through a continuous introduction of aldehydes and mixed titanium reagents generated from the organometallic precursors. The pipet reactor could be used repeatedly in different reactions without appreciable deterioration of the activity.

  17. A HIGHLY STEREOSELECTIVE, NOVEL COUPLING REACTION BETWEEN ALKYNES WITH ALDEHYDES. (R828129)

    Science.gov (United States)

    In the presence of indium triflate or gallium chloride, a novel coupling between internal alkynes and aldehydes occurred to give unsaturated ketones and [4+1] annulation products. Graphical Abstrac...

  18. Effect of phenolic aldehydes and flavonoids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii

    OpenAIRE

    Figueiredo, Ana Rita; Campos, Francisco; Freitas, Víctor de; Hogg, Tim; Couto, José António

    2008-01-01

    The aim of this work was to investigate the effect of wine phenolic aldehydes, flavonoids and tannins on growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Cultures were grown in ethanol-containing MRS/TJ medium supplemented with different concentrations of phenolic aldehydes or flavonoids and monitored spectrophotometrically. The effect of tannins was evaluated by monitoring the progressive inactivation of cells in ethanol-containing phosphate buffer supplemented...

  19. Crystal Structure of α-1,4-Glucan Lyase, a Unique Glycoside Hydrolase Family Member with a Novel Catalytic Mechanism

    NARCIS (Netherlands)

    Rozeboom, Henriëtte J.; Yu, Shukun; Madrid, Susan; Kalk, Kor H.; Zhang, Ran; Dijkstra, Bauke W.

    2013-01-01

    α-1,4-Glucan lyase (EC 4.2.2.13) from the red seaweed Gracilariopsis lemaneiformis cleaves α-1,4-glucosidic linkages in glycogen, starch, and malto-oligosaccharides, yielding the keto-monosaccharide 1,5-anhydro-D-fructose. The enzyme belongs to glycoside hydrolase family 31 (GH31) but degrades

  20. Aerobic oxidation of aldehydes under ambient conditions using supported gold nanoparticle catalysts

    DEFF Research Database (Denmark)

    Marsden, Charlotte Clare; Taarning, Esben; Hansen, David

    2008-01-01

    A new, green protocol for producing simple esters by selectively oxidizing an aldehyde dissolved in a primary alcohol has been established, utilising air as the oxidant and supported gold nanoparticles as catalyst. The oxidative esterifications proceed with excellent selectivities at ambient cond...... conditions; the reactions can be performed in an open flask and at room temperature. Benzaldehyde is even oxidised at a reasonable rate below -70 degrees C. Acrolein is oxidised to methyl acrylate in high yield using the same protocol.......A new, green protocol for producing simple esters by selectively oxidizing an aldehyde dissolved in a primary alcohol has been established, utilising air as the oxidant and supported gold nanoparticles as catalyst. The oxidative esterifications proceed with excellent selectivities at ambient...

  1. Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond.

    Science.gov (United States)

    Lin, Yangming; Wu, Kuang-Hsu Tim; Yu, Linhui; Heumann, Saskia; Su, Dang Sheng

    2017-09-11

    Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp 2 carbon planes are shown to play a key role in these reactions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by 14C putrescine method

    International Nuclear Information System (INIS)

    Fogel, W.A.; Bieganski, T.; Wozniak, J.; Maslinski, C.

    1978-01-01

    The Δ 1 pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi 14 C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation Δ 1 pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced Δ 1 pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on Δ 1 pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme. (author)

  3. Preparation of riboflavin specifically labeled in the 5'-hydroxymethyl terminus using a vitamin B2-aldehyde-forming enzyme from Schizophyllum commune

    International Nuclear Information System (INIS)

    Kekelidze, T.N.; Edmondson, D.E.; McCormick, D.B.

    1995-01-01

    A method is described for synthesis of riboflavin selectively labeled in the hydrogens at the 5'-hydroxymethyl position. In this method, a vitamin B 2 -aldehyde-forming enzyme from Schizophyllum commune is used to specifically and completely oxidize the 5'-hydroxymethyl of riboflavin to the 5'-aldehyde. This reaction is monitored spectrophotometrically by the reduction of 2,6-dichlorophenolindophenol at 600 nm. Appearance of aldehyde product was directly quantitated by reverse-phase high-performance liquid chromatography. Product is extracted from the incubation mixture by phenol after saturation with (NH 4 ) 2 SO 4 and then further purified by benzyl alcohol extraction. The 5'-aldehyde is reduced with appropriately labeled sodium borohydride to yield the vitamin specifically labeled in the 5'-hydroxymethyl group. (author)

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  5. Direct Vinylation of Alcohols or Aldehydes Employing Alkynes as Vinyl Donors: A Ruthenium Catalyzed C-C Bond Forming Transfer Hydrogenation

    Science.gov (United States)

    Patman, Ryan L.; Chaulagain, Mani Raj; Williams, Vanessa M.; Krische, Michael J.

    2011-01-01

    Under the conditions of ruthenium catalyzed transfer hydrogenation, 2-butyne couples to benzylic and aliphatic alcohols 1a–1i to furnish allylic alcohols 2a–2i, constituting a direct C-H vinylation of alcohols employing alkynes as vinyl donors. Under related transfer hydrogenation conditions employing formic acid as terminal reductant, 2-butyne couples to aldehydes 4a, 4b, and 4e to furnish identical products of carbonyl vinylation 2a, 2b, and 2e. Thus, carbonyl vinylation is achieved from the alcohol or the aldehyde oxidation level in the absence of any stoichiometric metallic reagents. Nonsymmetric alkynes 6a–6c couple efficiently to aldehyde 4b to provide allylic alcohols 2m–2o as single regioisomers. Acetylenic aldehyde 7a engages in efficient intramolecular coupling to deliver cyclic allylic alcohol 8a. PMID:19173651

  6. Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

    OpenAIRE

    Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

    2013-01-01

    The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

  7. Critical role of aldehydes in cigarette smoke-induced acute airway inflammation

    NARCIS (Netherlands)

    van der Toorn, Marco; Slebos, Dirk-Jan; de Bruin, Harold G.; Gras, Renee; Rezayat, Delaram; Jorge, Lucie; Sandra, Koen; van Oosterhout, Antoon J. M.

    2013-01-01

    Background: Cigarette smoking (CS) is the most important risk factor for COPD, which is associated with neutrophilic airway inflammation. We hypothesize, that highly reactive aldehydes are critical for CS-induced neutrophilic airway inflammation. Methods: BALB/c mice were exposed to CS, water

  8. An Efficient Amide-Aldehyde-Alkene Condensation: Synthesis for the N-Allyl Amides.

    Science.gov (United States)

    Quan, Zheng-Jun; Wang, Xi-Cun

    2016-02-01

    The allylamine skeleton represents a significant class of biologically active nitrogen compounds that are found in various natural products and drugs with well-recognized pharmacological properties. In this personal account, we will briefly discuss the synthesis of allylamine skeletons. We will focus on showing a general protocol for Lewis acid-catalyzed N-allylation of electron-poor N-heterocyclic amides and sulfonamide via an amide-aldehyde-alkene condensation reaction. The substrate scope with respect to N-heterocyclic amides, aldehydes, and alkenes will be discussed. This method is also capable of preparing the Naftifine motif from N-methyl-1-naphthamide or methyl (naphthalene-1-ylmethyl)carbamate, with paraformaldehyde and styrene in a one-pot manner. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. ¹³C metabolic flux analysis identifies an unusual route for pyruvate dissimilation in mycobacteria which requires isocitrate lyase and carbon dioxide fixation.

    Directory of Open Access Journals (Sweden)

    Dany J V Beste

    2011-07-01

    Full Text Available Mycobacterium tuberculosis requires the enzyme isocitrate lyase (ICL for growth and virulence in vivo. The demonstration that M. tuberculosis also requires ICL for survival during nutrient starvation and has a role during steady state growth in a glycerol limited chemostat indicates a function for this enzyme which extends beyond fat metabolism. As isocitrate lyase is a potential drug target elucidating the role of this enzyme is of importance; however, the role of isocitrate lyase has never been investigated at the level of in vivo fluxes. Here we show that deletion of one of the two icl genes impairs the replication of Mycobacterium bovis BCG at slow growth rate in a carbon limited chemostat. In order to further understand the role of isocitrate lyase in the central metabolism of mycobacteria the effect of growth rate on the in vivo fluxes was studied for the first time using ¹³C-metabolic flux analysis (MFA. Tracer experiments were performed with steady state chemostat cultures of BCG or M. tuberculosis supplied with ¹³C labeled glycerol or sodium bicarbonate. Through measurements of the ¹³C isotopomer labeling patterns in protein-derived amino acids and enzymatic activity assays we have identified the activity of a novel pathway for pyruvate dissimilation. We named this the GAS pathway because it utilizes the Glyoxylate shunt and Anapleurotic reactions for oxidation of pyruvate, and Succinyl CoA synthetase for the generation of succinyl CoA combined with a very low flux through the succinate--oxaloacetate segment of the tricarboxylic acid cycle. We confirm that M. tuberculosis can fix carbon from CO₂ into biomass. As the human host is abundant in CO₂ this finding requires further investigation in vivo as CO₂ fixation may provide a point of vulnerability that could be targeted with novel drugs. This study also provides a platform for further studies into the metabolism of M. tuberculosis using ¹³C-MFA.

  10. Molecular cloning and characterization of l-methionine γ-lyase from Streptomyces avermitilis.

    Science.gov (United States)

    Kudou, Daizou; Yasuda, Eri; Hirai, Yoshiyuki; Tamura, Takashi; Inagaki, Kenji

    2015-10-01

    A pyridoxal 5'-phosphate-dependent methionine γ-lyase (MGL) was cloned from Streptomyces avermitilis catalyzed the degradation of methionine to α-ketobutyrate, methanethiol, and ammonia. The sav7062 gene (1,242 bp) was corresponded to 413 amino acid residues with a molecular mass of 42,994 Da. The deduced amino acid sequence showed a high degree of similarity to those of other MGL enzymes. The sav7062 gene was overexpressed in Escherichia coli. The enzyme was purified to homogeneity and exhibited the MGL catalytic activities. We cloned the enzyme that has the MGL activity in Streptomyces for the first time. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. A second pectin lyase gene (pel2) from Aspergillus oryzae KBN616: its sequence analysis and overexpression, and characterization of the gene products.

    Science.gov (United States)

    Kitamoto, N; Yoshino-Yasuda, S; Ohmiya, K; Tsukagoshi, N

    2001-01-01

    A second pectin lyase gene, designated pel2, was isolated from a shoyu koji mold Aspergillus oryzae KBN616 and characterized. The structural gene comprised 1306 bp with three introns. The ORF encoded 375 amino acids with a signal peptide of 19 amino acids. The deduced amino acid sequence showed high similarity to those of A. oryzae Pel1, Aspergillus niger pectin lyases and Glomerella cingulata Pn1A. The pel2 gene was overexpressed under the control of the promoter of the A. oryzae TEF1 gene for purification and enzymatic characterization of its gene product. The gene product exhibited two molecular masses of 48 and 44 kDa due to different degrees of glycosylation. Both proteins had the same pH optimum of 6.0 and temperature optimum of 50 degrees C.

  12. Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

    Science.gov (United States)

    Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

    2017-08-30

    Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

  13. Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde

    OpenAIRE

    Plagens, Heike

    2001-01-01

    In dieser Arbeit wurden die bimolekularen Geschwindigkeitskonstanten für die Reaktionen von Hexanal, Heptanal, Oktanal und Nonanal mit OH and Cl Radikalen bei (298 ± 2) K und (1000 ± 20) mbar experimentell bestimmt. Ebenso wurde die Chlorgeschwindigkeitskonstante für Butanal gemessen. Die Werte sind (in Einheiten von cm3 Molekül-1 s-1) in Tabelle 1 zusammengefaßt. Tabelle 1: Aldehyde kOH kCl Butanal - (2,21 ± 0,16) · 10-10 Hexan...

  14. HPLC analysis of aldehydes in automobile exhaust gas: Comparison of exhaust odor and irritation in different types of gasoline and diesel engines

    International Nuclear Information System (INIS)

    Roy, Murari Mohon

    2008-01-01

    This study investigated high performance liquid chromatography (HPLC) to identify and measure aldehydes from automobile exhaust gas. Four aldehydes: formaldehyde (HCHO), acetaldehyde (CH 3 CHO), acrolein (H 2 C=CHCHO) and propionaldehyde (CH 3 CH 2 CHO) and one ketone, acetone (CH 3 ) 2 CO are separated. The other higher aldehydes in exhaust gas are very small and cannot be separated. A new method of gas sampling, hereafter called bag sampling in HPLC is introduced instead of the trapping gas sampling method. The superiority of the bag sampling method is its transient gas checking capability. In the second part of this study, HPLC results are applied to compare exhaust odor and irritation of exhaust gases in different types of gasoline and diesel engines. Exhaust odor, irritation and aldehydes are found worst in direct injection (DI) diesel engines and best in some good multi-point injection (MPI) gasoline and direct injection gasoline (DIG) engines. Indirect injection (IDI) diesel engines showed odor, irritation and aldehydes in between the levels of MPI gasoline, DIG and DI diesel engines

  15. YqhD. A broad-substrate range aldehyde reductase with various applications in production of biorenewable fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Jarboe, Laura R. [Iowa State Univ., Ames, IA (United States). Dept. of Chemical and Biological Engineering

    2011-01-15

    The Escherichia coli NADPH-dependent aldehyde reductase YqhD has contributed to a variety of metabolic engineering projects for production of biorenewable fuels and chemicals. As a scavenger of toxic aldehydes produced by lipid peroxidation, YqhD has reductase activity for a broad range of short-chain aldehydes, including butyraldehyde, glyceraldehyde, malondialdehyde, isobutyraldehyde, methylglyoxal, propanealdehyde, acrolein, furfural, glyoxal, 3-hydroxypropionaldehyde, glycolaldehyde, acetaldehyde, and acetol. This reductase activity has proven useful for the production of biorenewable fuels and chemicals, such as isobutanol and 1,3- and 1,2-propanediol; additional capability exists for production of 1-butanol, 1-propanol, and allyl alcohol. A drawback of this reductase activity is the diversion of valuable NADPH away from biosynthesis. This YqhD-mediated NADPH depletion provides sufficient burden to contribute to growth inhibition by furfural and 5-hydroxymethyl furfural, inhibitory contaminants of biomass hydrolysate. The structure of YqhD has been characterized, with identification of a Zn atom in the active site. Directed engineering efforts have improved utilization of 3-hydroxypropionaldehyde and NADPH. Most recently, two independent projects have demonstrated regulation of yqhD by YqhC, where YqhC appears to function as an aldehyde sensor. (orig.)

  16. A soft tissue adhesive based on aldehyde-sodium alginate and amino-carboxymethyl chitosan preparation through the Schiff reaction

    Science.gov (United States)

    Wu, Yu; Yuan, Liu; Sheng, Nai-an; Gu, Zi-qi; Feng, Wen-hao; Yin, Hai-yue; Morsi, Yosry; Mo, Xiu-mei

    2017-09-01

    Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate (ASA). Carboxymethyl chitosan was modified with ethylenediamine (ED) in the presence of water-soluble N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) to introduce additional amino groups to get amino-carboxymethyl chitosan (A-CS). Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff's base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff's base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.

  17. Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by /sup 14/C putrescine method

    Energy Technology Data Exchange (ETDEWEB)

    Fogel, W A [Polish Academy of Sciences, Cracow (Poland). Inst. of Pharmacology; Bieganski, T; Wozniak, J; Maslinski, C

    1978-01-01

    The ..delta../sup 1/ pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi /sup 14/C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation ..delta../sup 1/ pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced ..delta../sup 1/ pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on ..delta../sup 1/ pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme.

  18. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  19. The effect of cadmium on phenylalanine ammonia lyase activity and lipid peroxidation in pepper (Capsicum annuum L. seedlings

    Directory of Open Access Journals (Sweden)

    Esra Koç

    2015-04-01

    Full Text Available In this study, the effect on differrent concentrations (20, 40, 80µM ve 100 µM CdCl2 of cadmium (CdCl2 on the activity of phenylalanine ammonia-lyase (PAL and lipid peroxidation amount in leaf and stem of Kahramanmaraş- Hot (Capsicum annum L. pepper seedlings were researched. Activity of phenylalanine ammonia-lyase (PAL, the first enzyme in the phenylpropanoid biosynthetic pathway, was increased at 2 and 4 days in KM-Hot plants exposed to CdCl2 stress. The highest PAL activity was detected in 20 μM CdCl2 application, on the four day after the application in the leaves of KM-Hot pepper. Moreover, it was observed that treatment of pepper with Cd led to an increased the rate of lipid peroxidation (which is indicated by increasing MDA content in the leaf and stem tissues. The highest MDA content was detected in 80 μM CdCl2 application, on the four day after the application in the leaf tissues. These results suggest that the activation of PAL may be associated with increased production of MDA

  20. Titanocene(III)-Catalyzed Three-Component Reaction of Secondary Amides, Aldehydes, and Electrophilic Alkenes.

    Science.gov (United States)

    Zheng, Xiao; He, Jiang; Li, Heng-Hui; Wang, Ao; Dai, Xi-Jie; Wang, Ai-E; Huang, Pei-Qiang

    2015-11-09

    An umpolung Mannich-type reaction of secondary amides, aliphatic aldehydes, and electrophilic alkenes has been disclosed. This reaction features the one-pot formation of C-N and C-C bonds by a titanocene-catalyzed radical coupling of the condensation products, from secondary amides and aldehydes, with electrophilic alkenes. N-substituted γ-amido-acid derivatives and γ-amido ketones can be efficiently prepared by the current method. Extension to the reaction between ketoamides and electrophilic alkenes allows rapid assembly of piperidine skeletons with α-amino quaternary carbon centers. Its synthetic utility has been demonstrated by a facile construction of the tricyclic core of marine alkaloids such as cylindricine C and polycitorol A. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. [Simultaneous analysis of aromatic aldehydes and coumarins with high pressure liquid chromatography. Application to wines and brandies stored in oak barrels].

    Science.gov (United States)

    Salagoity-Auguste, M H; Tricard, C; Sudraud, P

    1987-04-17

    Aromatic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and coumarins (esculetin, umbelliferone, scopoletin and methylumbelliferone) are natural wood compounds. Storage of wines and brandies in oak barrels increases notably aldehydes and coumarins (particularly scopoletin) concentrations. These compounds were separated by high-performance liquid chromatography, on hydrocarbon bonded reversed-phase packings, with a water-acetonitrile elution gradient. They were first extracted from wines and brandies by diethyl ether and then injected on chromatographic column. A double detection was used to determine simultaneously aromatic aldehydes and coumarins by UV absorption and fluorescence respectively.

  2. Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

    Science.gov (United States)

    Zarante, Paola Helena Barros; Sodré, José Ricardo

    2018-02-01

    This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

  3. Mini-review: recent developments in hydroxynitrile lyases for industrial biotechnology.

    Science.gov (United States)

    Lanfranchi, Elisa; Steiner, Kerstin; Glieder, Anton; Hajnal, Ivan; Sheldon, Roger A; van Pelt, Sander; Winkler, Margit

    2013-12-01

    Hydroxynitrile lyases (HNLs) catalyze the cleavage as well as the formation of cyanohydrins. The latter reaction is valuable for the stereoselective C-C bond formation by condensation of HCN with carbonyl compounds. The resulting cyanohydrins serve as versatile building blocks for a broad range of chemical and enzymatic follow-up reactions. A significant number of (R)- and (S)-selective HNLs are known today and the number is still increasing. HNLs not only exhibit varying substrate scope but also differ in sequence and structure. Tailor-made enzymes for large-scale manufacturing of cyanohydrins with improved yield and enantiomeric excess are very interesting targets, which is reflected in a solid number of patents. This review will complement and extend our recent review with a strong focus on applications of HNLs for the synthesis of highly functionalized, chiral compounds with newest literature, recent and current patent literature.

  4. [Sudden death of a patient with 3-hydroxy-3-methylglutaryl coenzyme A lyase deficiency].

    Science.gov (United States)

    Vilaseca Busca, M A; Ribes Rubio, A; Briones Godino, P; Cusi Sánchez, V; Baraíbar Castelló, R; Gairi Taull, J M

    1990-02-01

    A new case of neonatal 3-hydroxy-3-methylglutaric aciduria is described. 3-hydroxy-3-methylglutaryl CoA lyase activities in leukocytes demonstrated the patient's homozygosity and the heterozygous character of the parents and two other members of the family. Dietetic management with low fat high carbohydrate diet together with protein restriction and carnitine resulted in a good control of the metabolic acidosis, the hypoglycemia, and the physical and neurological development. Nevertheless, sudden death occurred at the age thirteen months without any previous apparent trouble and the necropsia showed neither signs of infection nor hepatic or cardiac derangement.

  5. S-Nitrosomycothiol Reductase and Mycothiol Are Required for Survival Under Aldehyde Stress and Biofilm Formation in Mycobacterium smegmatis

    Science.gov (United States)

    Vargas, Derek; Hageman, Samantha; Gulati, Megha; Nobile, Clarissa J.; Rawat, Mamta

    2017-01-01

    We show that Mycobacterium smegmatis mutants disrupted in mscR, coding for a dual function S-nitrosomycothiol reductase and formaldehyde dehydrogenase, and mshC, coding for a mycothiol ligase and lacking mycothiol (MSH), are more susceptible to S-nitrosoglutathione (GSNO) and aldehydes than wild type. MSH is a cofactor for MscR, and both mshC and mscR are induced by GSNO and aldehydes. We also show that a mutant disrupted in egtA, coding for a γ-glutamyl cysteine synthetase and lacking in ergothioneine, is sensitive to nitrosative stress but not to aldehydes. In addition, we find that MSH and S-nitrosomycothiol reductase are required for normal biofilm formation in M. smegmatis, suggesting potential new therapeutic pathways to target to inhibit or disrupt biofilm formation. PMID:27321674

  6. Effect of phenolic aldehydes and flavonoids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii.

    Science.gov (United States)

    Figueiredo, Ana Rita; Campos, Francisco; de Freitas, Víctor; Hogg, Tim; Couto, José António

    2008-02-01

    The aim of this work was to investigate the effect of wine phenolic aldehydes, flavonoids and tannins on growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Cultures were grown in ethanol-containing MRS/TJ medium supplemented with different concentrations of phenolic aldehydes or flavonoids and monitored spectrophotometrically. The effect of tannins was evaluated by monitoring the progressive inactivation of cells in ethanol-containing phosphate buffer supplemented with grape seed extracts with different molecular weight tannins. Of the phenolic aldehydes tested, sinapaldehyde, coniferaldehyde, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde and 3,4,5-trihydroxybenzaldehyde significantly inhibited the growth of O. oeni VF, while vanillin and syringaldehyde had no effect at the concentrations tested. Lact. hilgardii 5 was only inhibited by sinapaldehyde and coniferaldehyde. Among the flavonoids, quercetin and kaempferol exerted an inhibitory effect especially on O. oeni VF. Myricetin and the flavan-3-ols studied (catechin and epicatechin) did not affect considerably the growth of both strains. Condensed tannins (particularly tetramers and pentamers) were found to strongly affect cell viability, especially in the case of O. oeni VF. In general, this strain was found to be more sensitive than Lact. hilgardii 5 to the phenolic compounds studied. This work contributes to the knowledge of the effect of different phenolic compounds on the activity of wine lactic acid bacteria, which, especially in the case of aldehydes and of different molecular weight fractions of tannins, is very scarce.

  7. Headspace solid-phase microextraction coupled to gas chromatography for the analysis of aldehydes in edible oils.

    Science.gov (United States)

    Ma, Chunhua; Ji, Jiaojiao; Tan, Connieal; Chen, Dongmei; Luo, Feng; Wang, Yiru; Chen, Xi

    2014-03-01

    Oxidation has important effects on the quality of edible oils. In particular, the generation of aldehydes produced by the oxidation of oils is one of the deteriorative factors to their quality. The aim of this study was to develop a method to determine the aldehydes as lipid oxidation markers in edible oils. Seven aldehydes generated from lipid oxidation were studied using headspace solid-phase microextraction coupled to gas chromatography with a flame ionization detector. The extraction efficiency of five commercial fibers was investigated and the influence of extraction temperature, extraction time, desorption temperature, and desorption time were optimized. The best result was obtained with 85 μm carboxen/polydimethylsiloxane, extraction at 50 °C for 15 min and desorption in the gas chromatography injector at 250 °C for 2 min. Under the optimized conditions, the content of hexanal was the highest of the seven aldehydes in all edible oils. The limits of detection for hexanal in the three oils were found to range from 4.6 to 10.2 ng L(-1). The reproducibility of the method was evaluated and the relative standard deviations were less than 8.9%. This developed approach was successfully applied to analyze hexanal in peanut oil, soy oil, and olive oil samples, and these results were compared with those obtained using the thiobarbituric acid-reactive substances (TBARs) method. © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Kinetic resolution and stereoselective synthesis of 3-substituted aspartic acids by using engineered methylaspartate ammonia lyases.

    Science.gov (United States)

    Raj, Hans; Szymanski, Wiktor; de Villiers, Jandré; Puthan Veetil, Vinod; Quax, Wim J; Shimamoto, Keiko; Janssen, Dick B; Feringa, Ben L; Poelarends, Gerrit J

    2013-08-19

    Enzymatic amino acid synthesis: Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described. These biocatalytic methodologies for the selective preparation of aspartic acid derivatives appear to be attractive alternatives for existing chemical methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Scientific Opinion on the safety and efficacy of straight-chain primary aliphatic alcohols/aldehydes/acids, acetals and esters with esters containing saturated alcohols and acetals containing saturated aldehydes (chemical group 1) when used as flavourings for all animal species

    OpenAIRE

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)

    2013-01-01

    Chemical group 1 (CG 1) consists of straight-chain primary aliphatic alcohols/aldehydes/acids, acetals and esters with esters containing saturated alcohols and acetals containing saturated aldehydes of which 86 are currently authorised for use as flavours in food. The FEEDAP Panel was unable to perform an assessment of ethyl oleate because of its insufficient purity. The following compounds are considered to be safe for all animal species at the use level proposed for feed flavourings: formic...

  10. Direct Aldehyde C-H Arylation and Alkylation via the Combination of Nickel, Hydrogen Atom Transfer, and Photoredox Catalysis.

    Science.gov (United States)

    Zhang, Xiaheng; MacMillan, David W C

    2017-08-23

    A mechanism that enables direct aldehyde C-H functionalization has been achieved via the synergistic merger of photoredox, nickel, and hydrogen atom transfer catalysis. This mild, operationally simple protocol transforms a wide variety of commercially available aldehydes, along with aryl or alkyl bromides, into the corresponding ketones in excellent yield. This C-H abstraction coupling technology has been successfully applied to the expedient synthesis of the medicinal agent haloperidol.

  11. A unified approach for the synthesis of symmetrical and unsymmetrical dibenzyl ethers from aryl aldehydes through reductive etherification

    Directory of Open Access Journals (Sweden)

    J. Sembian Ruso

    2016-05-01

    Full Text Available In this paper, we describe a simple and convenient conversion of aryl aldehydes to symmetrical dibenzyl ethers through reductive etherification. Similarly, unsymmetrical dibenzyl ether was obtained from aryl aldehyde and TES-protected benzyl alcohol. Triethyl silane with catalytic amount of InCl3 was found to be an efficient condition for the reductive etherification. Moreover, it exhibits remarkable functional group compatibility with yield ranging from good to excellent.

  12. Supported Rh-phosphine complex catalysts for continuous gas-phase decarbonylation of aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Mentzel, Uffe Vie

    2014-01-01

    Heterogeneous silica supported rhodium-phosphine complex catalysts are employed for the first time in the catalytic decarbonylation of aldehydes in continuous gas-phase. The reaction protocol is exemplified for the decarbonylation of p-tolualdehyde to toluene and further extended to other aromatic...

  13. Substituent effect of phenolic aldehyde inhibition on alcoholic fermentation by Saccharomyces cerevisiae

    Science.gov (United States)

    Rui Xie; Maobing Tu; Thomas Elder

    2016-01-01

    Phenolic compounds significantly inhibit microbial fermentation of biomass hydrolysates. To understand thequantitative structure-inhibition relationship of phenolic aldehydes on alcoholic fermentation, the effect of 11 differentsubstituted benzaldehydes on the final ethanol yield was examined. The results showed that the degree of phenolic...

  14. Requirement of argininosuccinate lyase for systemic nitric oxide production.

    Science.gov (United States)

    Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A; Premkumar, Muralidhar H; Campeau, Philippe M; Chen, Yuqing; Garg, Harsha K; Li, Li; Mian, Asad; Bertin, Terry K; Black, Jennifer O; Zeng, Heng; Tang, Yaoping; Reddy, Anilkumar K; Summar, Marshall; O'Brien, William E; Harrison, David G; Mitch, William E; Marini, Juan C; Aschner, Judy L; Bryan, Nathan S; Lee, Brendan

    2011-11-13

    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases.

  15. Molecularly Imprinted Sol-Gel-Based QCM Sensor Arrays for the Detection and Recognition of Volatile Aldehydes

    Directory of Open Access Journals (Sweden)

    Chuanjun Liu

    2017-02-01

    Full Text Available The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM sensor arrays based on molecularly imprinted sol-gel (MISG materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL; nonanal (NAL and bezaldehyde (BAL. The MISGs were prepared by a sol-gel procedure using two matrix precursors: tetraethyl orthosilicate (TEOS and tetrabutoxytitanium (TBOT. Aminopropyltriethoxysilane (APT; diethylaminopropyltrimethoxysilane (EAP and trimethoxy-phenylsilane (TMP were added as functional monomers to adjust the imprinting effect of the matrix. Hexanoic acid (HA; nonanoic acid (NA and benzoic acid (BA were used as psuedotemplates in view of their analogous structure to the target molecules as well as the strong hydrogen-bonding interaction with the matrix. Totally 13 types of MISGs with different components were prepared and coated on QCM electrodes by spin coating. Their sensing characters towards the three aldehyde vapors with different concentrations were investigated qualitatively. The results demonstrated that the response of individual sensors to each target strongly depended on the matrix precursors; functional monomers and template molecules. An optimization of the 13 MISG materials was carried out based on statistical analysis such as principle component analysis (PCA; multivariate analysis of covariance (MANCOVA and hierarchical cluster analysis (HCA. The optimized sensor array consisting of five channels showed a high discrimination ability on the aldehyde vapors; which was confirmed by quantitative comparison with a randomly selected array. It was suggested that both the molecularly imprinting (MIP effect and the matrix

  16. Cloning, expression and characterization of phenylalanine ammonia-lyase from Rhodotorula glutinis.

    Science.gov (United States)

    Zhu, Longbao; Cui, Wenjing; Fang, Yueqin; Liu, Yi; Gao, Xinxing; Zhou, Zhemin

    2013-05-01

    The industrial-scale production of phenylalanine ammonia-lyase (PAL) mainly uses strains of Rhodotorula. However, the PAL gene from Rhodotorula has not been cloned. Here, the full-length gene of PAL from Rhodotorula glutinis was isolated. It was 2,121 bp, encoding a polypeptide with 706 amino acids and a calculated MW of 75.5 kDa. Though R. glutinis is an anamorph of Rhodosporium toruloides, the amino acid sequences of PALs them are not the same (about 74 % identity). PAL was expressed in E. coli and characterized. Its specific activity was 4.2 U mg(-1) and the k cat/K m was 1.9 × 10(4) mM(-1) s(-1), exhibiting the highest catalytic ability among the reported PALs. The genetic and biochemical information reported here should facilitate future application in industry.

  17. Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins.

    Directory of Open Access Journals (Sweden)

    Stefano Varrella

    Full Text Available Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure.

  18. Substrate specificity and subcellular localization of the aldehyde-alcohol redox-coupling reaction in carp cones.

    Science.gov (United States)

    Sato, Shinya; Fukagawa, Takashi; Tachibanaki, Shuji; Yamano, Yumiko; Wada, Akimori; Kawamura, Satoru

    2013-12-20

    Our previous study suggested the presence of a novel cone-specific redox reaction that generates 11-cis-retinal from 11-cis-retinol in the carp retina. This reaction is unique in that 1) both 11-cis-retinol and all-trans-retinal were required to produce 11-cis-retinal; 2) together with 11-cis-retinal, all-trans-retinol was produced at a 1:1 ratio; and 3) the addition of enzyme cofactors such as NADP(H) was not necessary. This reaction is probably part of the reactions in a cone-specific retinoid cycle required for cone visual pigment regeneration with the use of 11-cis-retinol supplied from Müller cells. In this study, using purified carp cone membrane preparations, we first confirmed that the reaction is a redox-coupling reaction between retinals and retinols. We further examined the substrate specificity, reaction mechanism, and subcellular localization of this reaction. Oxidation was specific for 11-cis-retinol and 9-cis-retinol. In contrast, reduction showed low specificity: many aldehydes, including all-trans-, 9-cis-, 11-cis-, and 13-cis-retinals and even benzaldehyde, supported the reaction. On the basis of kinetic studies of this reaction (aldehyde-alcohol redox-coupling reaction), we found that formation of a ternary complex of a retinol, an aldehyde, and a postulated enzyme seemed to be necessary, which suggested the presence of both the retinol- and aldehyde-binding sites in this enzyme. A subcellular fractionation study showed that the activity is present almost exclusively in the cone inner segment. These results suggest the presence of an effective production mechanism of 11-cis-retinal in the cone inner segment to regenerate visual pigment.

  19. Purification and characterization of selenocysteine beta-lyase from Citrobacter freundii

    International Nuclear Information System (INIS)

    Chocat, P.; Esaki, N.; Tanizawa, K.; Nakamura, K.; Tanaka, H.; Soda, K.

    1985-01-01

    The purification and characterization of bacterial selenocysteine beta-lyase, an enzyme which specifically catalyzes the cleavage of L-selenocysteine to L-alanine and Se0, are presented. The enzyme, purified to near homogeneity from Citrobacter freundii, is monomeric with a molecular weight of ca. 64,000 and contains 1 mol of pyridoxal 5'-phosphate as a cofactor per mol of enzyme. L-Selenocysteine is the sole substrate. L-Cysteine is a competitive inhibitor of the enzyme. The enzyme also catalyzes the alpha, beta elimination of beta-chloro-L-alanine to form NH 3 , pyruvate, and Cl- and is irreversibly inactivated during the reaction. The physicochemical properties, e.g., amino acid composition and subunit structure, of the bacterial enzyme are fairly different from those of the pig liver enzyme. However, the catalytic properties of both enzymes, e.g., substrate specificity and inactivation by the substrate or a mechanism-based inactivator, beta-chloro-L-alanine, are very similar

  20. Cardiac-specific overexpression of aldehyde dehydrogenase 2 exacerbates cardiac remodeling in response to pressure overload

    Directory of Open Access Journals (Sweden)

    Sujith Dassanayaka

    2018-07-01

    Full Text Available Pathological cardiac remodeling during heart failure is associated with higher levels of lipid peroxidation products and lower abundance of several aldehyde detoxification enzymes, including aldehyde dehydrogenase 2 (ALDH2. An emerging idea that could explain these findings concerns the role of electrophilic species in redox signaling, which may be important for adaptive responses to stress or injury. The purpose of this study was to determine whether genetically increasing ALDH2 activity affects pressure overload-induced cardiac dysfunction. Mice subjected to transverse aortic constriction (TAC for 12 weeks developed myocardial hypertrophy and cardiac dysfunction, which were associated with diminished ALDH2 expression and activity. Cardiac-specific expression of the human ALDH2 gene in mice augmented myocardial ALDH2 activity but did not improve cardiac function in response to pressure overload. After 12 weeks of TAC, ALDH2 transgenic mice had larger hearts than their wild-type littermates and lower capillary density. These findings show that overexpression of ALDH2 augments the hypertrophic response to pressure overload and imply that downregulation of ALDH2 may be an adaptive response to certain forms of cardiac pathology. Keywords: Heart failure, Hypertrophy, Oxidative stress, Aldehydes, Cardiac remodeling, Hormesis

  1. Application of two analytic techniques of sampling for the determination of aldehydes in air and in rain water in three areas of Costa Rica

    International Nuclear Information System (INIS)

    Vega Montero, D. I

    2001-01-01

    The aldehydes are of supreme interest in the quality of the air of Costa Rica; reason why it is very important to determine them qualitative and quantitatively. This study has as objectives the identification and quantification of aldehydes in samples of air and of rain water in three areas of Costa Rica, to compare two methods of taking of samples of air and to correlate the concentration of the aldehydes in the different points of taking of samples. The sampling one carries out in three located stations, in the Hill of the Piroclasticos (3 km. To the Northeast of the active crater of the Volcano Irazu), Escazu (it plants potabilizadora of water) and in Turrucares (facilities of the Rural Watch). The used sampling devices, denuders and cartridges, they were recovered with a breakup of 2,4-dinitrofenilhidrazina o'clock like absorbent reagent, which I form the corresponding hidrazonas in presence of the aldehydes. The identification and quantification of the aldehydes, one carries out by means of chromatography it liquidates of high resolution. The comparison among the concentrations of the aldehydes in air gathered by the two used sampling methods indicates that a significant difference exists among them, at a level of trust of 95% [es

  2. Formation of high-molecular-weight compounds via the heterogeneous reactions of gaseous C8-C10 n-aldehydes in the presence of atmospheric aerosol components

    Science.gov (United States)

    Han, Yuemei; Kawamura, Kimitaka; Chen, Qingcai; Mochida, Michihiro

    2016-02-01

    A laboratory study on the heterogeneous reactions of straight-chain aldehydes was performed by exposing n-octanal, nonanal, and decanal vapors to ambient aerosol particles. The aerosol and blank filters were extracted using methanol. The extracts were nebulized and the resulting compositions were examined using a high-resolution time-of-flight aerosol mass spectrometer. The mass spectral analysis showed that the exposures of the aldehydes to aerosol samples increased the peak intensities in the high mass range. The peaks in the mass spectra of the aerosol samples after exposure to different aldehydes were characterized by a homologous series of peak shifts due to the addition of multiple CH2 units. This result is explained by the formation of high-molecular-weight (HMW) compounds that contain single or multiple aldehyde moieties. The HMW fragment peaks for the blank filters exposed to n-aldehydes were relatively weak, indicating an important contribution from the ambient aerosol components to the formation of the HMW compounds. Among the factors affecting the overall interaction of aldehydes with atmospheric aerosol components, gas phase diffusion possibly limited the reactions under the studied conditions; therefore, their occurrence to a similar degree in the atmosphere is not ruled out, at least for the reactions involving n-nonanal and decanal. The major formation pathways for the observed HMW products may be the self-reactions of n-aldehydes mediated by atmospheric aerosol components and the reactions of n-aldehydes with organic aerosol components. The observed formation of HMW compounds encourages further investigations into their effects on the aerosol properties as well as the organic aerosol mass in the atmosphere.

  3. A Highly Efficient Solvent-Free Acetalization of Aldehydes to 1,1 ...

    African Journals Online (AJOL)

    1,1-Diacetates are prepared in excellent yields from aldehydes and acetic anhydride under solvent-free conditions at room temperature in short reaction times using catalytic amount of sulfonic acid functionalized silica (SiO2-Pr-SO3H) which could be easily handled and removed from the mixture of reaction. Keywords: 1 ...

  4. Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the β-Subunit of Phycocyanin in Arthrospira platensis FACHB314

    Directory of Open Access Journals (Sweden)

    Fei Wu

    2016-03-01

    Full Text Available A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin β-Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB producing genes (hoxI and pcyA, while the other contained the gene of the β-Subunit of phycobiliprotein (cpcB and the lyase gene (cpcU, cpcS, or cpcU/S were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent β-PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the β-Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314.

  5. Copper(I)/TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes with Ambient Air

    Science.gov (United States)

    Hoover, Jessica M.; Steves, Janelle E.; Stahl, Shannon S.

    2012-01-01

    This protocol describes a practical laboratory-scale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective CuI/TEMPO catalyst system. The catalyst is prepared in situ from commercially available reagents, and the reactions are performed in a common organic solvent (acetonitrile) with ambient air as the oxidant. Three different reaction conditions and three procedures for the isolation and purification of the aldehyde product are presented. The oxidations of eight different alcohols, described here, include representative examples of each reaction condition and purification method. Reaction times vary from 20 min to 24 h, depending on the alcohol, while the purification methods each take about 2 h. The total time necessary for the complete protocol ranges from 3 – 26 h. PMID:22635108

  6. Radical cations in radiation chemistry of aldehydes. ESR study and quantum chemical analysis

    International Nuclear Information System (INIS)

    Belevskii, V.N.; Tyurin, D.A.; Chuvilkin, N.D.

    1998-01-01

    Quantum-chemical (MNDO-UHF) calculations of electronic, spin and energy characteristics of radical cations (RC) of ethanal, propanal, butanal, and pentanal and their distonic isomers were performed. The calculations both with 'frozen' (vertical ionization) and completely optimize geometry (adiabatic approximation) were made. It was been shown that the most positive charge and spin population are localized at O atoms and adjacent C atom as well as at aldehyde protons. The C-H bonds corresponding to those protons as well as neighboring C-O and C-C bonds are considerable weaker (longer) in radical cations as compared to their neutral precursors. That is why such reaction centers are apt to deprotonation with the formation of acyl radical as well as to α- and β-splitting (scission) which are well-known from aldehydes mass-spectra. Our calculations shown that distonic RC (products of intramolecular H-atom transfer) are more stable as compare to their classical isomers: e.g. the difference in energy ΔE = -0.95 eV, -1.2 eV, and -1.5 eV for tree distonic isomers of butanal RC as compare to classical isomer, ΔE -1.2 eV for distonic RC of ethanal. The results of calculations are effectively correlated with ESR data obtained in freonic solutions, X- and gamma-irradiated at 77 K and in liquid aldehydes, X-irradiated by using 2,4,6-tri-tert-burylnitrosobenzene (BNB) and t-BuNO (NtB) as a spin traps. (author)

  7. Chemoselective Preparation of 1,1-Diacetates from Aldehydes, Mediated by a Keggin Heteropolyacid Under Solvent Free Conditions at Room Temperature

    Directory of Open Access Journals (Sweden)

    G. Romanelli

    2007-01-01

    Full Text Available A simple, general and efficient method has been developed for the conversion of aldehydes to 1,1-diacetates using acetic anhydride, a catalytic amount of non commercial Keggin heteropolyacid (H6 PalMo11O40 (1% mol in solvent free conditions at room temperature. Aromatic and aliphatic, simple and conjugated aldehydes were protected with excellent yields.

  8. Sexual Dimorphism in the Selenocysteine Lyase Knockout Mouse.

    Science.gov (United States)

    Ogawa-Wong, Ashley N; Hashimoto, Ann C; Ha, Herena; Pitts, Matthew W; Seale, Lucia A; Berry, Marla J

    2018-01-31

    Selenium (Se) is an essential micronutrient known for its antioxidant properties and health benefits, attributed to its presence in selenoproteins as the amino acid, selenocysteine. Selenocysteine lyase (Scly) catalyzes hydrolysis of selenocysteine to selenide and alanine, facilitating re-utilization of Se for de novo selenoprotein synthesis. Previously, it was reported that male Scly -/- mice develop increased body weight and body fat composition, and altered lipid and carbohydrate metabolism, compared to wild type mice. Strikingly, females appeared to present with a less severe phenotype, suggesting the relationship between Scly and energy metabolism may be regulated in a sex-specific manner. Here, we report that while body weight and body fat gain occur in both male and female Scly -/- mice, strikingly, males are susceptible to developing glucose intolerance, whereas female Scly -/- mice are protected. Because Se is critical for male reproduction, we hypothesized that castration would attenuate the metabolic dysfunction observed in male Scly -/- mice by eliminating sequestration of Se in testes. We report that fasting serum insulin levels were significantly reduced in castrated males compared to controls, but islet area was unchanged between groups. Finally, both male and female Scly -/- mice exhibit reduced hypothalamic expression of selenoproteins S, M, and glutathione peroxidase 1.

  9. Sexual Dimorphism in the Selenocysteine Lyase Knockout Mouse

    Directory of Open Access Journals (Sweden)

    Ashley N. Ogawa-Wong

    2018-01-01

    Full Text Available Selenium (Se is an essential micronutrient known for its antioxidant properties and health benefits, attributed to its presence in selenoproteins as the amino acid, selenocysteine. Selenocysteine lyase (Scly catalyzes hydrolysis of selenocysteine to selenide and alanine, facilitating re-utilization of Se for de novo selenoprotein synthesis. Previously, it was reported that male Scly−/− mice develop increased body weight and body fat composition, and altered lipid and carbohydrate metabolism, compared to wild type mice. Strikingly, females appeared to present with a less severe phenotype, suggesting the relationship between Scly and energy metabolism may be regulated in a sex-specific manner. Here, we report that while body weight and body fat gain occur in both male and female Scly−/− mice, strikingly, males are susceptible to developing glucose intolerance, whereas female Scly−/− mice are protected. Because Se is critical for male reproduction, we hypothesized that castration would attenuate the metabolic dysfunction observed in male Scly−/− mice by eliminating sequestration of Se in testes. We report that fasting serum insulin levels were significantly reduced in castrated males compared to controls, but islet area was unchanged between groups. Finally, both male and female Scly−/− mice exhibit reduced hypothalamic expression of selenoproteins S, M, and glutathione peroxidase 1.

  10. Visible-light-promoted and one-pot synthesis of phenanthridines and quinolines from aldehydes and O-acyl hydroxylamine.

    Science.gov (United States)

    An, Xiao-De; Yu, Shouyun

    2015-06-05

    A one-pot synthesis of phenanthridines and quinolines from commercially available or easily prepared aldehydes has been reported. O-(4-Cyanobenzoyl)hydroxylamine was utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes catalyzed by Brønsted acid. O-Acyl oximes were then subjected to visible light photoredox catalyzed cyclization via iminyl radicals to furnish aza-arenes. A variety of phenanthridines and quinolines have been prepared assisted by Brønsted acid and photocatalyst under visible light at room temperature with satisfactory yields.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  12. QSTR with extended topochemical atom (ETA) indices. 14. QSAR modeling of toxicity of aromatic aldehydes to Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Kunal, E-mail: kunalroy_in@yahoo.com [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India); Das, Rudra Narayan [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India)

    2010-11-15

    Aldehydes are a toxic class of chemicals causing severe health hazards. In this background, quantitative structure-toxicity relationship (QSTR) models have been developed in the present study using Extended Topochemical Atom (ETA) indices for a large group of 77 aromatic aldehydes for their acute toxicity against the protozoan ciliate Tetrahymena pyriformis. The ETA models have been compared with those developed using various non-ETA topological indices. Attempt was also made to include the n-octanol/water partition coefficient (log K{sub o/w}) as an additional descriptor considering the importance of hydrophobicity in toxicity prediction. Thirty different models were developed using different chemometric tools. All the models have been validated using internal validation and external validation techniques. The statistical quality of the ETA models was found to be comparable to that of the non-ETA models. The ETA models have shown the important effects of steric bulk, lipophilicity, presence of electronegative atom containing substituents and functionality of the aldehydic oxygen to the toxicity of the aldehydes. The best ETA model (without using log K{sub o/w}) shows encouraging statistical quality (Q{sub int}{sup 2}=0.709,Q{sub ext}{sup 2}=0.744). It is interesting to note that some of the topological models reported here are better in statistical quality than previously reported models using quantum chemical descriptors.

  13. Aldehyde levels in e-cigarette aerosol: Findings from a replication study and from use of a new-generation device.

    Science.gov (United States)

    Farsalinos, Konstantinos E; Kistler, Kurt A; Pennington, Alexander; Spyrou, Alketa; Kouretas, Dimitris; Gillman, Gene

    2018-01-01

    A recent study identified high aldehyde emissions from e-cigarettes (ECs), that when converted to reasonable daily human EC liquid consumption, 5 g/day, gave formaldehyde exposure equivalent to 604-3257 tobacco cigarettes. We replicated this study and also tested a new-generation atomizer under verified realistic (no dry puff) conditions. CE4v2 atomizers were tested at 3.8 V and 4.8 V, and a Nautilus Mini atomizer was tested at 9.0 W and 13.5 W. All measurements were performed in a laboratory ISO-accredited for EC aerosol collection and aldehyde measurements. CE4v2 generated dry puffs at both voltage settings. Formaldehyde levels were >10-fold lower, acetaldehyde 6-9-fold lower and acrolein 16-26-fold lower than reported in the previous study. Nautilus Mini did not generate dry puffs, and minimal aldehydes were emitted despite >100% higher aerosol production per puff compared to CE4v2 (formaldehyde: 16.7 and 16.5 μg/g; acetaldehyde: 9.6 and 10.3 μg/g; acrolein: 8.6 and 11.7 μg/g at 9.0 W and 13.5 W, respectively). EC liquid consumption of 5 g/day reduces aldehyde exposure by 94.4-99.8% compared to smoking 20 tobacco cigarettes. Checking for dry puffs is essential for EC emission testing. Under realistic conditions, new-generation ECs emit minimal aldehydes/g liquid at both low and high power. Validated methods should be used when analyzing EC aerosol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal.

    Science.gov (United States)

    Reyes, Efraim; Vicario, Jose L; Badía, Dolores; Carrillo, Luisa

    2006-12-21

    [Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.

  15. Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes

    Czech Academy of Sciences Publication Activity Database

    Verevkin, S. P.; Krasnykh, E. L.; Vasiltsova, T. V.; Koutek, Bohumír; Doubský, Jan; Heintz, A.

    2003-01-01

    Roč. 206, - (2003), s. 331-339 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z4055905 Keywords : aldehydes * vapor pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.165, year: 2003

  16. Dual Enantioselective Control using D-phenylglycine-L-proline-derived Catalysts for the Enantioselective Addition of Diethylzinc to Aldehyde

    International Nuclear Information System (INIS)

    Kang, Seock Yong; Park, Yong Sun

    2016-01-01

    Dipeptide-derived catalysts are of great interest in various asymmetric transformations because of their short and simple preparation and easy modification of their modular structure by using different α-amino acids. We recently reported the first example of dipeptide-catalyzed enantioselective addition of dialkylzinc to aldehydes. We have developed a novel D-Phg-L-Pro dipeptide-derived catalyst for the addition of diethylzinc to aromatic aldehydes. We also disclosed an effective chiral switching by simply modifying nonchiral part of D-Phg-L-Pro dipeptide.

  17. Structural Snapshots of an Engineered Cystathionine-γ-lyase Reveal the Critical Role of Electrostatic Interactions in the Active Site

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wupeng; Stone, Everett; Zhang, Yan Jessie

    2017-02-01

    Enzyme therapeutics that can degrade l-methionine (l-Met) are of great interest as numerous malignancies are exquisitely sensitive to l-Met depletion. To exhaust the pool of methionine in human serum, we previously engineered an l-Met-degrading enzyme based on the human cystathionine-γ-lyase scaffold (hCGL-NLV) to circumvent immunogenicity and stability issues observed in the preclinical application of bacterially derived methionine-γ-lyases. To gain further insights into the structure–activity relationships governing the chemistry of the hCGL-NLV lead molecule, we undertook a biophysical characterization campaign that captured crystal structures (2.2 Å) of hCGL-NLV with distinct reaction intermediates, including internal aldimine, substrate-bound, gem-diamine, and external aldimine forms. Curiously, an alternate form of hCGL-NLV that crystallized under higher-salt conditions revealed a locally unfolded active site, correlating with inhibition of activity as a function of ionic strength. Subsequent mutational and kinetic experiments pinpointed that a salt bridge between the phosphate of the essential cofactor pyridoxal 5'-phosphate (PLP) and residue R62 plays an important role in catalyzing β- and γ-eliminations. Our study suggests that solvent ions such as NaCl disrupt electrostatic interactions between R62 and PLP, decreasing catalytic efficiency.

  18. Defensome against toxic diatom aldehydes in the sea urchin Paracentrotus lividus.

    Directory of Open Access Journals (Sweden)

    Vincenzo Marrone

    Full Text Available Many diatom species produce polyunsaturated aldehydes, such as decadienal, which compromise embryonic and larval development in benthic organisms. Here newly fertilized Paracentrotus lividus sea urchins were exposed to low concentration of decadienal and the expression levels of sixteen genes, implicated in a broad range of functional responses, were followed by Real Time qPCR in order to identify potential decadienal targets. We show that at low decadienal concentrations the sea urchin Paracentrotus lividus places in motion different classes of genes to defend itself against this toxic aldehyde, activating hsp60 and two proteases, hat and BP10, at the blastula stage and hsp56 and several other genes (14-3-3ε, p38 MAPK, MTase, and GS at the prism stage. At this latter stage all genes involved in skeletogenesis (Nec, uni, SM50 and SM30 were also down-expressed, following developmental abnormalities that mainly affected skeleton morphogenesis. Moreover, sea urchin embryos treated with increasing concentrations of decadienal revealed a dose-dependent response of activated target genes. Finally, we suggest that this orchestrated defense system against decadienal represents part of the chemical defensome of P. lividus affording protection from environmental toxicants.

  19. Quantification of Dissolved and Particulate Polyunsaturated Aldehydes in the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Raffaella Casotti

    2011-03-01

    Full Text Available Polyunsaturated aldehydes (PUA are supposed to play critical roles in chemically-mediated plankton interactions. Laboratory studies suggest that they act as mediators of chemical defense and chemical communication. PUA are oxylipins containing an α,β,γ,δ-unsaturated aldehyde structure element and are mainly found in diatoms. We present here a detailed surface mapping of PUA during a spring bloom of the diatom Skeletonema marinoi in the Adriatic Sea. We monitored dissolved PUA, as well as particulate PUA, which are produced by phytoplankton after cell disintegration. Our survey revealed a patchy distribution of PUA and shows that at most stations S. marinoi is the major contributor to the overall PUA. Our data also suggest that lysis of a diatom bloom can contribute significantly to the dissolved PUA concentrations and that other producers, which are smaller in cell size compared to diatoms, have to be taken into account as well if the total PUA content of marine samples is considered. The analyses of samples collected in deeper water suggests that diatom contribution to PUA decreases with depth, while smaller-sized unidentified organisms take place as dominant contributors to the PUA concentrations.

  20. ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch

    Directory of Open Access Journals (Sweden)

    Steven Zhao

    2016-10-01

    Full Text Available Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY, cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency.

  1. ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch.

    Science.gov (United States)

    Zhao, Steven; Torres, AnnMarie; Henry, Ryan A; Trefely, Sophie; Wallace, Martina; Lee, Joyce V; Carrer, Alessandro; Sengupta, Arjun; Campbell, Sydney L; Kuo, Yin-Ming; Frey, Alexander J; Meurs, Noah; Viola, John M; Blair, Ian A; Weljie, Aalim M; Metallo, Christian M; Snyder, Nathaniel W; Andrews, Andrew J; Wellen, Kathryn E

    2016-10-18

    Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA) plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY), cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL) and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst

    Directory of Open Access Journals (Sweden)

    Viviane P. de Souza

    2016-11-01

    Full Text Available Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

  3. A General and Convenient Method for the Rhodium-Catalyzed Decarbonylation of Aldehydes

    DEFF Research Database (Denmark)

    Kreis, Michael; Palmelund, Anders; Bunch, Lennart

    2006-01-01

    A practical protocol for the decarbonylation of a wide range of aldehydes has been developed by using commercially available RhCl3x3H2O and dppp in a diglyme solution. This method gives rise to decarbonylated products in good to high yield and is particularly useful because of its experimental si...

  4. Mild and Efficient One Pot Synthesis of Imidazolinesand Benzimidazoles from Aldehydes

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2007-01-01

    Full Text Available A series of some imidazolines and benzimidazoles were synthesizedfrom various aldehydes and 1,2-diamines in the presence of ceric(IVammonium nitrate (CAN. The title compounds were prepared via one stepsynthesis method. The simplicity of the reaction conditions with shorterreaction time and with out use of column chromatography to get the pureproducts in high yields makes this method more attractive for organic chemists.

  5. Identification and characterisation of Aedes aegypti aldehyde dehydrogenases involved in pyrethroid metabolism.

    Directory of Open Access Journals (Sweden)

    Nongkran Lumjuan

    Full Text Available Pyrethroid insecticides, especially permethrin and deltamethrin, have been used extensively worldwide for mosquito control. However, insecticide resistance can spread through a population very rapidly under strong selection pressure from insecticide use. The upregulation of aldehyde dehydrogenase (ALDH has been reported upon pyrethroid treatment. In Aedes aegypti, the increase in ALDH activity against the hydrolytic product of pyrethroid has been observed in DDT/permethrin-resistant strains. The objective of this study was to identify the role of individual ALDHs involved in pyrethroid metabolism.Three ALDHs were identified; two of these, ALDH9948 and ALDH14080, were upregulated in terms of both mRNA and protein levels in a DDT/pyrethroid-resistant strain of Ae. aegypti. Recombinant ALDH9948 and ALDH14080 exhibited oxidase activities to catalyse the oxidation of a permethrin intermediate, phenoxybenzyl aldehyde (PBald, to phenoxybenzoic acid (PBacid.ALDHs have been identified in association with permethrin resistance in Ae. aegypti. Characterisation of recombinant ALDHs confirmed the role of this protein in pyrethroid metabolism. Understanding the biochemical and molecular mechanisms of pyrethroid resistance provides information for improving vector control strategies.

  6. Palladium-Catalyzed Anti-Markovnikov Oxidation of Allylic Amides to Protected beta-Amino Aldehydes

    NARCIS (Netherlands)

    Dong, Jiajia; Harvey, Emma C.; Fananas-Mastral, Martin; Browne, Wesley R.; Feringa, Bernard

    2014-01-01

    A general method for the preparation of N-protected beta-amino aldehydes from allylic amines or linear allylic alcohols is described. Here the Pd(II)-catalyzed oxidation of N-protected allylic amines with benzoquinone is achieved in tBuOH under ambient conditions with excellent selectivity toward

  7. Secondary amine-initiated three-component synthesis of 3,4-dihydropyrimidinones and thiones involving alkynes, aldehydes and thiourea/urea

    Directory of Open Access Journals (Sweden)

    Jie-Ping Wan

    2014-01-01

    Full Text Available The three-component reactions of aldehydes, electron deficient alkynes and ureas/thioureas have been smoothly performed to yield a class of unprecedented 3,4-dihydropyrimidinones and thiones (DHPMs. The reactions are initiated by the key transformation of an enamine-type activation involving the addition of a secondary amine to an alkyne, which enables the subsequent incorporation of aldehydes and ureas/thioureas. This protocol tolerates a broad range of aryl- or alkylaldehydes, N-substituted and unsubstituted ureas/thioureas and alkynes to yield the corresponding DHPMs with specific regioselectivity.

  8. A Comparative study on VOCs and aldehyde-ketone emissions from a spark Ignition vehicle fuelled on compressed natural gas and gasoline

    International Nuclear Information System (INIS)

    Shah, A.N.

    2012-01-01

    In this work, an experimental study was conducted on a spark ignition (SI) vehicle fuelled on compressed natural gas (CNG), and gasoline to compare the unregulated emissions such as volatile organic compounds (VOCs) and aldehyde-ketones or carbonyls. In the meantime, ozone forming potential (OFP) of pollutants was also calculated on the basis of their specific reactivity (SR). The vehicle was run on a chassis dynamometer following the Chinese National Standards test scheduled for light duty vehicle (LDV) emissions. According to the results, total aldehyde-ketones were increased by 39.4% due to the substantial increase in formaldehyde and acrolein + acetone emissions, while VOCs and BTEX (benzene, toluene, ethyl benzene, and xylene) reduced by 85.2 and 86% respectively, in case of CNG fuelled vehicle as compared to gasoline vehicle. Although total aldehyde-ketones were higher with CNG relative to gasoline, their SR was lower due decrease in acetaldehyde, propionaldehyde, crotonaldehyde, and methacrolein species having higher maximum incremental reactivity (MIR) values. The SR of VOCs and aldehyde-ketones emitted from CNG fuelled vehicle was decreased by above 10% and 32% respectively, owing to better physicochemical properties and more complete burning of CNG as compared to gasoline. (author)

  9. Determination of unsymmetrical dimethylhydrazine in water and soil by derivatization with aromatic aldehydes using GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Atamaniouk, V [Ukrainian Academy of Science (Ukraine); Ananieva, L [Ukrainian Ministry of Defence (Ukraine); Ladanowski, C [Environment Canada, Ottawa, ON (Canada). Emergencies Engineering Div.; Cathum, S; Whittaker, H

    1996-09-01

    An analytical technique for the detection of hydrazine in environmental samples was described. Unsymmetrical dimethyl hydrazine (UDMH) is used in rocket fuel as a high-energy propellant. It is highly toxic and has been banned in Canada and the United States since 1989. However, in 1995 traces of UDMH were found in apples and the dangerous carcinogenic NDMA (a major byproduct of UDMH oxidation) was detected in drinking water in Ontario. The analysis of UDMH by derivation of seven aldehydes was investigated. A gas chromatography and a mass spectroscopy method of determining the presence of UDMH in water by reacting it with various aldehydes in dichromethane, was developed. 43 refs., 8 tabs., 15 figs.

  10. Phenylalanine ammonia-lyase through evolution: A bioinformatic approach

    Directory of Open Access Journals (Sweden)

    Shiva Hemmati

    2015-03-01

    Full Text Available Phenylalanine ammonia-lyase (PAL is the first entry enzyme of the phenylpropanoid pathway that converts phenylalanine to cinnamic acid which is the precursor of various secondary metabolites. PAL is recently formulated for phenylketonuric patients in pegylated forms; therefore, screening a PAL with the highest affinity to the substrate is of a great importance. PAL exists in all higher plants and some fungi and few bacteria. Ancestors of land plants have been adopted by evolving metabolic pathways. A multi-gene family encodes PAL by gene duplication events in most plants. In this study, the taxonomic distribution and phylogeny of pal gene found in land plants, fungi and bacteria have been analyzed. It seems that the ancestor of plants acquired a pal gene via horizontal gene transfer in symbioses with bacteria and fungi. Gymnosperms have kept a diverse set of pal genes that arose from gene duplication events. In angiosperms, after the divergence of dicotyledons from monocots, pal genes were duplicated many times. The close paralogues of pal genes in some species indicate expansion of gene families after the divergence in plant pal gene evolution. Interestingly, some of the plant pals clustered by species in a way that pals within one species are more closely related to each other than to homologs in the other species which indicates this duplication event occurred more recently.

  11. Characterisation of recombinant human fatty aldehyde dehydrogenase: implications for Sjögren-Larsson syndrome

    NARCIS (Netherlands)

    Lloyd, Matthew D.; Boardman, Kieren D. E.; Smith, Andrew; van den Brink, Daan M.; Wanders, Ronald J. A.; Threadgill, Michael D.

    2007-01-01

    Fatty aldehyde dehydrogenase (FALDH) is an NAD+-dependent oxidoreductase involved in the metabolism of fatty alcohols. Enzyme activity has been implicated in the pathology of diabetes and cancer. Mutations in the human gene inactivate the enzyme and cause accumulation of fatty alcohols in

  12. Self-Standing Nanocellulose Janus-Type Films with Aldehyde and Carboxyl Functionalities.

    Science.gov (United States)

    Nypelö, Tiina; Amer, Hassan; Konnerth, Johannes; Potthast, Antje; Rosenau, Thomas

    2018-03-12

    Nanocellulose-based self-standing films are becoming a substrate for flexible electronics, diagnostics, and sensors. Strength and surface chemistry are vital variables for these film-based endeavors, the former is one of the assets of nanocellulose. To contribute to the latter, nanocellulose films are tuned with a side-specific functionalization, having an aldehyde and a carboxyl side. The functionalities were obtained combining premodification of the film components by periodate oxidation with ozone post-treatment. Periodate oxidation of cellulose nanocrystals results in film components that interact through intra- and intermolecular hemiacetals and lead to films with an elastic modulus of 11 GPa. The ozone treatment of one film side induces conversion of the aldehyde into carboxyl functionalities. The ozone treatment on individual crystals was largely destructive. Remarkably, such degradation is not observed for the self-standing film, and the film strength at break is preserved. Preserving a physically intact film despite ozone treatment is a credit to using the dry film structure held together by interparticle covalent linkages. Additionally, gas-phase post-treatment avoids disintegration that could result from immersion into solvents. The crystalline cellulose "Janus" film is suggested as an interfacial component in biomaterial engineering, separation technology, or in layered composite materials for tunable affinity between the layers.

  13. Antisickling activity evaluation of 4 aromatic aldehydes using proton magnetic relaxation

    International Nuclear Information System (INIS)

    Falcon Dieguez, J.E.; Grisel del Toro Garcia; Yamirka Alonso Geli; Lores Guevara, M.A.

    2006-12-01

    The formation of a Shiff base aduct hemoglobin-aromatic aldehyde, has been reported as inhibitor of the hemoglobin S polymerization. Using the Proton Magnetic Resonance methodology, the polymerization kinetics can be studied and the delay time can be determined. Our studies in vitro show the inhibitor effect of the isovanillin, o-vanillin, m-hydroxybenzaldehyde and the p-hydroxybenzaldehyde, using molar ratio (hemoglobin S/compound) 1:1, 1:4 and 1:8. The td increment (expressed in percents) obtained for each one of the molar ratio was the following: isovanillin: 34±6% (1:1), 68±16% (1:4), ovanillin: 26±10% (1:1), 63±20% (1:4), m-hydroxybelzaldehyde: 16±4% (1:1), 44±12% (1:4) and the phydroxybenzaldehyde: 10±3% (1:1), 32±8% (1:4). In the case of 1:8, the characteristic kinetics curve was not obtained. At the used concentrations, hemolytic activity was not found on the red blood cell. These results confirm the antisickling activity of these aromatic aldehydes, for a technique different to that reported in literature that also allows the quantification of concentration effect. The same ones will facilitate the study of the therapeutic usefulness of these compounds in the sickle cell anemia treatment. (author)

  14. Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes

    Directory of Open Access Journals (Sweden)

    Kundu Kshama

    2014-01-01

    Full Text Available (±-Camphor-10-sulfonic acid (CSA catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthylphenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25°C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol% was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

  15. Microwave Assisted Solvent Free Synthesis of Azomethines from Aryl Aldehydes on Melamin Formaldehyde as Solid Support

    Directory of Open Access Journals (Sweden)

    Ramin Rezaei

    2011-01-01

    Full Text Available Various aryl aldehydes underwent prompt one pot conversion into the corresponding azomethines in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation.

  16. Melamine Trisulfonic Acid as a New, Efficient and Reusable Catalyst for the Chemoselective Oxathioacetalyzation of Aldehydes

    International Nuclear Information System (INIS)

    Shirini, F.; Albadi, J.

    2010-01-01

    We developed an efficient and high yielding method for the chemoselective oxathioacetalyzation of aldehydes. Relatively short reaction times, high efficiency, heterogeneous reaction conditions, availability and recyclability of the reagent and easy work-up are among the other advantages of this method, which make this procedure a useful and attractive addition to the available methods. We are exploring further applications of MTSA for the other types of functional group transformations in our laboratory. 1,3-Oxathiolanes are synthetically important protecting groups for aldehydes due to their considerable stability under a variety of reaction conditions, ease of formation and removal, equality to acyl carbanions in C-C bond forming reactions, and use in enantioselective synthesis of tertiary α-hydroxy acids and glycols

  17. Mechanistic investigation of the gold-catalyzed aerobic oxidation of aldehydes: added insight from Hammett studies and isotopic labelling experiments

    DEFF Research Database (Denmark)

    Fristrup, Peter; Johansen, Louise Bahn; Christensen, Claus Hviid

    2008-01-01

    The gold-catalyzed aerobic oxidation of aldehydes proceeds through development of a partial negative charge and has a significant kinetic isotope effect (k(H)/k(D) = 2.8-2.9), which illustrates that activation of the C-H bond takes place in the rate-determining step.......The gold-catalyzed aerobic oxidation of aldehydes proceeds through development of a partial negative charge and has a significant kinetic isotope effect (k(H)/k(D) = 2.8-2.9), which illustrates that activation of the C-H bond takes place in the rate-determining step....

  18. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    International Nuclear Information System (INIS)

    Phillips, T.K.; Clarke, S.M.; Bhinde, T.; Castro, M.A.; Millan, C.; Medina, S.

    2011-01-01

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C 7 , C 9 and C 11 ) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C 11 homologue is determined to have a plane group of either p2, pgb or pgg, and for the C 7 homologue the p2 plane group is preferred.

  19. Physiologically based in silico modelling to examine DNA adduct formation by different food-borne a,ß-unsaturated aldehydes at realistic low dietary exposure levels

    NARCIS (Netherlands)

    Kiwamoto, R.

    2015-01-01

    Abstract (R.Kiwamoto ISBN 978-94-6257-284-3)

    Various α,β-unsaturated aldehydes are present in fruits, vegetables, spices, or processed products containing these items as natural constituents or as added food flavouring agents. Because of the α,β-unsaturated aldehyde moiety the β carbon in

  20. Synthesis of d‐ and l‐Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process†

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L.; Weise, Nicholas J.; Ahmed, Syed T.

    2015-01-01

    Abstract The synthesis of substituted d‐phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one‐pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high‐throughput solid‐phase screening method has also been developed to identify PALs with higher rates of formation of non‐natural d‐phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d‐configured product. Furthermore, the system was extended to the preparation of those l‐phenylalanines which are obtained with a low ee value using PAL amination. PMID:27478261

  1. Synthesis of d- and l-Phenylalanine Derivatives by Phenylalanine Ammonia Lyases: A Multienzymatic Cascade Process**

    Science.gov (United States)

    Parmeggiani, Fabio; Lovelock, Sarah L; Weise, Nicholas J; Ahmed, Syed T; Turner, Nicholas J

    2015-01-01

    The synthesis of substituted d-phenylalanines in high yield and excellent optical purity, starting from inexpensive cinnamic acids, has been achieved with a novel one-pot approach by coupling phenylalanine ammonia lyase (PAL) amination with a chemoenzymatic deracemization (based on stereoselective oxidation and nonselective reduction). A simple high-throughput solid-phase screening method has also been developed to identify PALs with higher rates of formation of non-natural d-phenylalanines. The best variants were exploited in the chemoenzymatic cascade, thus increasing the yield and ee value of the d-configured product. Furthermore, the system was extended to the preparation of those l-phenylalanines which are obtained with a low ee value using PAL amination. PMID:25728350

  2. Comparison of expression, purification and characterization of a new pectate lyase from Phytophthora capsici using two different methods

    Directory of Open Access Journals (Sweden)

    Zhang Xiuguo

    2011-04-01

    Full Text Available Abstract Background Pectate lyases (PELs play an important role in the infection process of plant pathogens and also have a commercial significance in industrial applications. Most of the PELs were expressed as soluble recombinant proteins, while a few recombinant proteins were insoluble. The production of a large-scale soluble recombinant PEL would allow not only a more detailed structural and functional characterization of this enzyme but also may have important applications in the food industry. Results We cloned a new pectate lyase gene (Pcpel2 from Phytophthora capsici. Pcpel2 was constructed by pET system and pMAL system, and both constructs were used to express the PCPEL2 in Escherichia coli BL21 (DE3 pLysS. The expressed products were purified using affinity chromatography and gel filtration chromatography. The purity, specific activity and pathogenicity of the purified PCPEL2 expressed by the pMAL system were higher than the purified PCPEL2 expressed by the pET system. In addition, some other characteristics of the purified PCPEL2 differed from the two systems, such as crystallographic features. Purified PCPEL2 expressed by the pMAL system was crystallized by the hanging-drop vapour-diffusion method at 289 K, and initial crystals were grown. Conclusion The two different methods and comparison presented here would be highly valuable in obtaining an ideal enzyme for the downstream experiments, and supply an useful alternative to purify some insoluble recombinant proteins.

  3. Reductive amination of aldehyde 2,4-dinitorophenylhydrazones using 2-picoline borane and high-performance liquid chromatographic analysis.

    Science.gov (United States)

    Uchiyama, Shigehisa; Inaba, Yohei; Matsumoto, Mariko; Suzuki, Gen

    2009-01-01

    A new method for the determination of carbonyls in air using 2,4-dinitrophenylhydrazine (DNPH) has been developed. The traditional method for the measurement of carbonyl compounds, using DNPH to form the corresponding 2,4-dinitrophenylhydrazone (DNPhydrazone) derivatives, is subject to analytical errors because DNPhydrazones form both E- and Z-geometrical isomers as a result of the C=N double bond. To overcome this issue, a method for transforming the C=N double bond into a C-N single bond, using reductive amination of DNPhydrazone derivatives, has been developed. Reductive amination of aldehyde DNPhydrazones was carried out by adding 2-picoline borane acetonitrile solution in eluate through the DNPH-cartridge. The amination reactions of C(1)-C(10) aldehyde DNPhydrazones were completely converted into the reduced forms within 40 min in the presence of 1 mmol/L 2-picoline borane and 20 mmol/L of phosphoric acid. These reduced forms were very stable and did not change when stored for 2 weeks at room temperature. The absorption maximum wavelengths of the reduced forms from C(1)-C(10) aldehyde DNPhydrazones were 351-352 nm and shifted 6-7 nm toward shorter wavelengths when compared to the corresponding DNPhydrazones, and the molar absorption coefficients were 1.5 x 10(4) (C(1)) to 2.2 x 10(4) L/mol/cm (C(10)). Complete separation between C(1)-C(10) aldehyde DNPhydrazones and the corresponding reduced forms can be achieved by operating the HPLC in gradient mode using an Ascentis RP-Amide column (150 mm x 4.6 mm i.d.). The RSDs of DNPhydrazone (Z + E) peak areas ranged from 0.40-0.66 and those of the corresponding reduced forms ranged from 0.26-0.41. It was shown that the reductive amination method gave improved HPLC analytical precision because of the absence of isomers.

  4. The replicative DNA polymerase of herpes simplex virus 1 exhibits apurinic/apyrimidinic and 5′-deoxyribose phosphate lyase activities

    OpenAIRE

    Bogani, Federica; Boehmer, Paul E.

    2008-01-01

    Base excision repair (BER) is essential for maintaining genome stability both to counter the accumulation of unusual bases and to protect from base loss in the DNA. Herpes simplex virus 1 (HSV-1) is a large dsDNA virus that encodes its own DNA replication machinery, including enzymes involved in nucleotide metabolism. We report on a replicative family B and a herpesvirus-encoded DNA Pol that possesses DNA lyase activity. We have discovered that the catalytic subunit of the HSV-1 DNA polymeras...

  5. Study of a specific lignin model: γ-oxidation and how it influences the hydrolysis efficiency of alcohol-aldehyde dehydrogenation copolymers.

    Science.gov (United States)

    Bouxin, Florent; Baumberger, Stéphanie; Renault, Jean-Hugues; Dole, Patrice

    2011-05-01

    Six coniferyl alcohol-coniferaldehyde dehydrogenation copolymers (DHcoPs) were synthesized in order to determine the influence of an increased number of aldehyde functions on hydrolysis. After heterogeneous hydrolysis using acidic Montmorillonite K10 clay, the DHcoPs were thioacidolyzed and analyzed by gel permeation chromatography (GPC). Comparison of the thioacidolyzed products, with and without the hydrolysis step, showed that there was a greater proportion of condensation reaction in the absence of aldehyde. When the coniferaldehyde content in the initial synthetic mixture was more than 30% (w/w), only a low fraction of condensed products was generated during the K10 clay hydrolysis step. This suggests that condensation pathways are mainly due to the alcohol present in the γ-position in the DHcoPs. Investigation of the reactivity and the potential condensation of aldehyde and alcohol monomers under hydrolysis conditions showed the important conversion of coniferyl alcohol and conversely the stability of coniferaldehyde. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Cystathionine γ-lyase deficiency mediates neurodegeneration in Huntington’s disease

    Science.gov (United States)

    Paul, Bindu D.; Sbodio, Juan I.; Xu, Risheng; Vandiver, M. Scott; Cha, Jiyoung Y.; Snowman, Adele M.; Snyder, Solomon H.

    2015-01-01

    Huntington’s disease is an autosomal dominant disease associated with a mutation in the gene encoding huntingtin (Htt) leading to expanded polyglutamine repeats of mutant Htt (mHtt) that elicit oxidative stress, neurotoxicity, and motor and behavioural changes1. Huntington’s disease is characterized by highly selective and profound damage to the corpus striatum, which regulates motor function. Striatal selectivity of Huntington’s disease may reflect the striatally selective small G protein Rhes binding to mHtt and enhancing its neurotoxicity2. Specific molecular mechanisms by which mHtt elicits neurodegeneration have been hard to determine. Here we show a major depletion of cystathionine γ-lyase (CSE), the biosynthetic enzyme for cysteine, in Huntington’s disease tissues, which may mediate Huntington’s disease pathophysiology. The defect occurs at the transcriptional level and seems to reflect influences of mHtt on specificity protein 1, a transcriptional activator for CSE. Consistent with the notion of loss of CSE as a pathogenic mechanism, supplementation with cysteine reverses abnormalities in cultures of Huntington’s disease tissues and in intact mouse models of Huntington’s disease, suggesting therapeutic potential. PMID:24670645

  7. ENVIRONMENTAL TECHNOLOGY PROTOCOL VERIFICATION REPORT, EMISSIONS OF VOCS AND ALDEHYDES FROM COMMERCIAL FURNITURE (WITH APPENDICES)

    Science.gov (United States)

    As part of a U.S. Environmental Protection Agency Environmental Technology Verification program, the Research Triangle Institute (RTI) developed a test protocol for measuring volatile organic compounds and aldehydes in a large chamber. RTI convened stakeholders for the commercial...

  8. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei [South China Univ. of Technology, Guangzhou (China)

    2014-06-15

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS{sub 4})) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS{sub 4}). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS{sub 4})/H{sub 2}O{sub 2} was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS{sub 4})/H{sub 2}O{sub 2} system.

  9. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    International Nuclear Information System (INIS)

    Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei

    2014-01-01

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H 2 O 2 ) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS 4 )) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS 4 ). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS 4 )/H 2 O 2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS 4 )/H 2 O 2 system

  10. Reductive detoxification of acrolein as a potential role for aldehyde reductase (AKR1A) in mammals.

    Science.gov (United States)

    Kurahashi, Toshihiro; Kwon, Myoungsu; Homma, Takujiro; Saito, Yuka; Lee, Jaeyong; Takahashi, Motoko; Yamada, Ken-Ichi; Miyata, Satoshi; Fujii, Junichi

    2014-09-12

    Aldehyde reductase (AKR1A), a member of the aldo-keto reductase superfamily, suppresses diabetic complications via a reduction in metabolic intermediates; it also plays a role in ascorbic acid biosynthesis in mice. Because primates cannot synthesize ascorbic acid, a principle role of AKR1A appears to be the reductive detoxification of aldehydes. In this study, we isolated and immortalized mouse embryonic fibroblasts (MEFs) from wild-type (WT) and human Akr1a-transgenic (Tg) mice and used them to investigate the potential roles of AKR1A under culture conditions. Tg MEFs showed higher methylglyoxal- and acrolein-reducing activities than WT MEFs and also were more resistant to cytotoxicity. Enzymatic analyses of purified rat AKR1A showed that the efficiency of the acrolein reduction was about 20% that of glyceraldehyde. Ascorbic acid levels were quite low in the MEFs, and while the administration of ascorbic acid to the cells increased the intracellular levels of ascorbic acid, it had no affect on the resistance to acrolein. Endoplasmic reticulum stress and protein carbonylation induced by acrolein treatment were less evident in Tg MEFs than in WT MEFs. These data collectively indicate that one of the principle roles of AKR1A in primates is the reductive detoxification of aldehydes, notably acrolein, and protection from its detrimental effects. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

    Science.gov (United States)

    Goedde, H W; Agarwal, D P; Harada, S; Rothhammer, F; Whittaker, J O; Lisker, R

    1986-01-01

    While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed. PMID:3953578

  12. Radon and aldehyde concentrations in the indoor environment. Final report

    International Nuclear Information System (INIS)

    Moschandreas, D.J.; Rector, H.E.

    1981-04-01

    Findings regarding indoor air contaminants in the energy-efficient residence (EER) in Mt. Airy, Maryland are reported. The objectives of the study were to collect and analyze relevant air quality samples (specifically radon and aldehydes), characterize the indoor air quality with respect to radon and aldehydes, and develop relationships between air infiltration rates and contaminant levels. One-fifth of the measured formaldehyde concentrations were in the range that may cause health concerns. Although indoor temperature and relative humidity affect indoor HCHO concentration, the elevated formaldehyde concentrations were measured under very low air infiltration rates. The data show that ventilation of the indoor air space is somewhat effective in reducing high HCHO concentrations. The operation of the heat exchanger led to an increase of the air infiltration rate which in turn resulted in substantial reduction of formaldehyde concentrations. A considerable number of the collected samples of indoor air displayed radon concentrations at levels higher than 1.0 to 4.0 nCim -3 (assuming an equilibrium factor of 0.5, these radon levels would correspond to working levels above the health guidelines suggested by the US EPA for homes in Florida built on land reclaimed from phosphate mining). As in the case of indoor formaldehyde concentrations, elevated indoor concentrations are substantially reduced when the infiltration rate is increased. The data base shows that the use of the air to air heat exchanger leads to reduction of indoor radon concentration by increasing the residential ventilation rate

  13. Adenylosuccinate lyase (ADSL) and infantile autism: Absence of previously reported point mutation

    Energy Technology Data Exchange (ETDEWEB)

    Fon, E.A.; Sarrazin, J.; Rouleau, G.A. [Montreal General Hospital (Canada)] [and others

    1995-12-18

    Autism is a heterogeneous neuropsychiatric syndrome of unknown etiology. There is evidence that a deficiency in the enzyme adenylosuccinate lyase (ADSL), essential for de novo purine biosynthesis, could be involved in the pathogenesis of certain cases. A point mutation in the ADSL gene, resulting in a predicted serine-to-proline substitution and conferring structural instability to the mutant enzyme, has been reported previously in 3 affected siblings. In order to determine the prevalence of the mutation, we PCR-amplified the exon spanning the site of this mutation from the genomic DNA of patients fulfilling DSM-III-R criteria for autistic disorder. None of the 119 patients tested were found to have this mutation. Furthermore, on preliminary screening using single-strand conformation polymorphism (SSCP), no novel mutations were detected in the coding sequence of four ADSL exons, spanning approximately 50% of the cDNA. In light of these findings, it appears that mutations in the ADSL gene represent a distinctly uncommon cause of autism. 12 refs., 2 figs.

  14. Production of endo-pectate lyase by two stage cultivation of Erwinia carotovora

    Energy Technology Data Exchange (ETDEWEB)

    Fukuoka, Satoshi; Kobayashi, Yoshiaki

    1987-02-26

    The productivity of endo-pectate lyase from Erwinia carotovora GIR 1044 was found to be greatly improved by two stage cultivation: in the first stage the bacterium was grown with an inducing carbon source, e.g., pectin, and in the second stage it was cultivated with glycerol, xylose, or fructose with the addition of monosodium L-glutamate as nitrogen source. In the two stage cultivation using pectin or glycerol as the carbon source the enzyme activity reached 400 units/ml, almost 3 times as much as that of one stage cultivation in a 10 liter fermentor. Using two stage cultivation in the 200 liter fermentor improved enzyme productivity over that in the 10 liter fermentor, with 500 units/ml of activity. Compared with the cultivation in Erlenmeyer flasks, fermentor cultivation improved enzyme productivity. The optimum cultivating conditions were agitation of 480 rpm with aeration of 0.5 vvm at 28 /sup 0/C. (4 figs, 4 tabs, 14 refs)

  15. Sphingosine-1-phosphate (S1P) displays sustained S1P1 receptor agonism and signaling through S1P lyase-dependent receptor recycling.

    Science.gov (United States)

    Gatfield, John; Monnier, Lucile; Studer, Rolf; Bolli, Martin H; Steiner, Beat; Nayler, Oliver

    2014-07-01

    The sphingosine-1-phosphate (S1P) type 1 receptor (S1P1R) is a novel therapeutic target in lymphocyte-mediated autoimmune diseases. S1P1 receptor desensitization caused by synthetic S1P1 receptor agonists prevents T-lymphocyte egress from secondary lymphoid organs into the circulation. The selective S1P1 receptor agonist ponesimod, which is in development for the treatment of autoimmune diseases, efficiently reduces peripheral lymphocyte counts and displays efficacy in animal models of autoimmune disease. Using ponesimod and the natural ligand S1P, we investigated the molecular mechanisms leading to different signaling, desensitization and trafficking behavior of S1P1 receptors. In recombinant S1P1 receptor-expressing cells, ponesimod and S1P triggered Gαi protein-mediated signaling and β-arrestin recruitment with comparable potency and efficiency, but only ponesimod efficiently induced intracellular receptor accumulation. In human umbilical vein endothelial cells (HUVEC), ponesimod and S1P triggered translocation of the endogenous S1P1 receptor to the Golgi compartment. However, only ponesimod treatment caused efficient surface receptor depletion, receptor accumulation in the Golgi and degradation. Impedance measurements in HUVEC showed that ponesimod induced only short-lived Gαi protein-mediated signaling followed by resistance to further stimulation, whereas S1P induced sustained Gαi protein-mediated signaling without desensitization. Inhibition of S1P lyase activity in HUVEC rendered S1P an efficient S1P1 receptor internalizing compound and abrogated S1P-mediated sustained signaling. This suggests that S1P lyase - by facilitating S1P1 receptor recycling - is essential for S1P-mediated sustained signaling, and that synthetic agonists are functional antagonists because they are not S1P lyase substrates. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. MICROWAVE-ASSISTED CU (I) CATALYZED SOLVENT-FREE THREE COMPONENT COUPLING OF ALDEHYDE, ALKYNE AND AMINE

    Science.gov (United States)

    Direct Grignard type addition of terminal alkynes to in situ generated imines, from aldehydes and amines, occurs under microwave irradiation using CuBr alone in a one-pot operation. This solventless approach provides ready access to propargylamines and is applicable both...

  17. Congenital Adrenal Hyperplasia due to 17-alpha-hydoxylase/17,20-lyase Deficiency Presenting with Hypertension and Pseudohermaphroditism: First Case Report from Oman

    Directory of Open Access Journals (Sweden)

    Waad-Allah S. Mula-Abed

    2014-01-01

    Full Text Available This is the first report of congenital adrenal hyperplasia (CAH due to combined 17α-hydroxylase/17,20 lyase deficiency in an Omani patient who was initially treated for many years as a case of hypertension. CAH is an uncommon disorder that results from a defect in steroid hormones biosynthesis in the adrenal cortex. The clinical presentation depends on the site of enzymatic mutations and the types of accumulated steroid precursors. A 22-year-old woman who was diagnosed to have hypertension since the age of 10 years who was treated with anti-hypertensive therapy was referred to the National Diabetes and Endocrine Centre, Royal Hospital, Oman. The patient also had primary amenorrhea and features of sexual infantilism. Full laboratory and radio-imaging investigations were done. Adrenal steroids, pituitary function and karyotyping study were performed and the diagnosis was confirmed by molecular mutation study. Laboratory investigations revealed adrenal steroids and pituitary hormones profile in addition to 46XY karyotype that are consistent with the diagnosis of CAH due to 17α-hydroxylase deficiency. Extensive laboratory workup revealed low levels of serum cortisol (and its precursors 17α-hydroxyprogesterone and 11-deoxycortisol, adrenal androgens (dehydroepiandrosterone sulfate and androstenedione, and estrogen (estradiol; and high levels of mineralocorticoids precursors (11-deoxycorticosterone and corticosterone with high levels of ACTH, FSH and LH. Mutation analysis revealed CYP17A1-homozygous mutation (c.287G>A p.Arg96Gln resulting in the complete absence of 17α-hydroxylase/17,20-lyase activity. The patient was treated with dexamethasone and ethinyl estradiol with cessation of anti-hypertensive therapy. A review of the literature was conducted to identify previous studies related to this subtype of CAH. This is the first biochemically and genetically proven case of CAH due to 17α-hydroxylase/17,20-lyase deficiency in Oman and in the Arab

  18. Radiation-Induced Polymerization of Aldehydes and Ketones; Polymerisation radiochimique des aldehydes et des cetones; Radiatsionnaya polimerizatsiya al'degidov i ketonov; Polimerizacion radioinducida de aldehidos y cetonas

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, K.; Yamaoka, H.; Fujiwara, K.; Sakamoto, M.; Mori, S.; Natori, T.; Yoshida, H.; Okamura, S. [Japanese Association for Radiation Research on Polymers, Neyagawa Osaka (Japan); Kyoto University, Kyoto (Japan)

    1963-11-15

    Several kinds of aldehydes and ketones are polymerized by irradiation. Formaldehyde can be polymerized into high molecular weight polyoxymethylene by radiation-induced polymerization in the liquid phase at low temperatures. The polymerization mechanism is considered to be a cationic chain reaction both in the case of bulk and of solution in methylenechloride and toluene, but to be anionic in ethylether. Acetaldehyde and propionaldehyde are recognized as being hardly polymerized in the pure liquid phase, but easily polymerized in the presence of {gamma}-alumina. In the solid state polymerization, crystalline polymers are obtained as the stable- for- heat-treatment form under suitableconditions. Glyoxal can be polymerized into a three-dimensional network polymer. With formaldehyde it can be copolymerized into some cross-linked polyoxymethylene. Acetones such as chloroor bromoacetone and methylethylketone or diacetyl can be polymerized in the solid state into polymers which are unstable. Ketene can be polymerized into a polyester-type polymer with liquid phase polymerization; polyketone is obtained additionally when polymerization is carried out in the solid state. The copolymer with formaldehyde is slightly more stable. Dimethylketene can be easily polymerized both in the liquid and solid states into polyacetal. All these polymerizations are special examples of radiation-induced reactions and the reaction kinetics are interesting. Some details of this are discussed here. (author) [French] Plusieurs sortes d'aldehydes et de cetones se polymerisent sous l'effet des rayons gamma. L'aldehyde formique peut se transformer en polyoxymethylene de poids moleculaire eleve par polymerisation radiochimique en phase liquide a basses temperatures. On pense que la polymerisation est une reaction cationique en chaine lorsqu'il s'agit de masses ou de solutions dans du chlorure de methylene et du toluene, mais une reaction anionique en chaule dans une solution d'ether ethylique. L'aldehyde

  19. The Skin Bacterium Propionibacterium acnes Employs Two Variants of Hyaluronate Lyase with Distinct Properties

    DEFF Research Database (Denmark)

    Nazipi, Seven; Stødkilde-Jørgensen, Kristian; Scavenius, Carsten

    2017-01-01

    Hyaluronic acid (HA) and other glycosaminoglycans are extracellular matrix components in the human epidermis and dermis. One of the most prevalent skin microorganisms, Propionibacterium acnes, possesses HA-degrading activity, possibly conferred by the enzyme hyaluronate lyase (HYL). In this study......, we identified the HYL of P. acnes and investigated the genotypic and phenotypic characteristics. Investigations include the generation of a P. acneshyl knockout mutant and HYL activity assays to determine the substrate range and formed products. We found that P. acnes employs two distinct variants...... of the observed differences between P. acnes phylotype IA and IB/II strains. Whereas type IA strains are primarily found on the skin surface and associated with acne vulgaris, type IB/II strains are more often associated with soft and deep tissue infections, which would require elaborate tissue invasion...

  20. Molecular cloning and characterization of an Erwinia carotovora subsp. carotovora pectin lyase gene that responds to DNA-damaging agents.

    OpenAIRE

    McEvoy, J L; Murata, H; Chatterjee, A K

    1990-01-01

    recA-mediated production of pectin lyase (PNL) and the bacteriocin carotovoricin occurs in Erwinia carotovora subsp. carotovora 71 when this organism is subjected to agents that damage or inhibit the synthesis of DNA. The structural gene pnlA was isolated from a strain 71 cosmid gene library following mobilization of the cosmids into a moderate PNL producer, strain 193. The cosmid complemented pnl::Tn5 but not ctv::Tn5 mutations. A constitutive level of PNL activity was detected in RecA+ and ...

  1. A quick responding quartz crystal microbalance sensor array based on molecular imprinted polyacrylic acids coating for selective identification of aldehydes in body odor.

    Science.gov (United States)

    Jha, Sunil K; Hayashi, Kenshi

    2015-03-01

    In present work, a novel quartz crystal microbalance (QCM) sensor array has been developed for prompt identification of primary aldehydes in human body odor. Molecularly imprinted polymers (MIP) are prepared using the polyacrylic acid (PAA) polymer matrix and three organic acids (propenoic acid, hexanoic acid and octanoic acid) as template molecules, and utilized as QCM surface coating layer. The performance of MIP films is characterized by 4-element QCM sensor array (three coated with MIP layers and one with pure PAA for reference) dynamic and static responses to target aldehydes: hexanal, heptanal, and nonanal in single, binary, and tertiary mixtures at distinct concentrations. The target aldehydes were selected subsequent to characterization of body odor samples with solid phase-micro extraction gas chromatography mass spectrometer (SPME-GC-MS). The hexanoic acid and octanoic acid imprinted PAA exhibit fast response, and better sensitivity, selectivity and reproducibility than the propenoic acid, and non-imprinted PAA in array. The response time and recovery time for hexanoic acid imprinted PAA are obtained as 5 s and 12 s respectively to typical concentrations of binary and tertiary mixtures of aldehydes using the static response. Dynamic sensor array response matrix has been processed with principal component analysis (PCA) for visual, and support vector machine (SVM) classifier for quantitative identification of target odors. Aldehyde odors were identified successfully in principal component (PC) space. SVM classifier results maximum recognition rate 79% for three classes of binary odors and 83% including single, binary, and tertiary odor classes in 3-fold cross validation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Electron impact ionization of cycloalkanes, aldehydes, and ketones

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dhanoj; Antony, Bobby, E-mail: bka.ism@gmail.com [Department of Applied Physics, Indian School of Mines, Dhanbad, JH 826 004 (India)

    2014-08-07

    The theoretical calculations of electron impact total ionization cross section for cycloalkane, aldehyde, and ketone group molecules are undertaken from ionization threshold to 2 keV. The present calculations are based on the spherical complex optical potential formalism and complex scattering potential ionization contribution method. The results of most of the targets studied compare fairly well with the recent measurements, wherever available and the cross sections for many targets are predicted for the first time. The correlation between the peak of ionization cross sections with number of target electrons and target parameters is also reported. It was found that the cross sections at their maximum depend linearly with the number of target electrons and with other target parameters, confirming the consistency of the values reported here.

  3. Green Tea Polyphenols Decrease Strecker Aldehydes and Bind to Proteins in Lactose-Hydrolyzed UHT Milk.

    Science.gov (United States)

    Jansson, Therese; Rauh, Valentin; Danielsen, Bente P; Poojary, Mahesha M; Waehrens, Sandra S; Bredie, Wender L P; Sørensen, John; Petersen, Mikael A; Ray, Colin A; Lund, Marianne N

    2017-12-06

    The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.

  4. Histochemical detection of the in vivo produced cellular aldehydes by means of direct Schiff's reaction in CCl/sub 4/ intoxicated rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Taper, H.S.; Somer, M.P.; Lans, M.; Gerlache, J. de; Roberfroid, M.

    1988-04-01

    A histochemical technique for detection of the in vivo induced cellular aldehydes based on the direct Schiff's reaction is reported in this paper. CCl/sub 4/-intoxicated rat liver was used as an experimental model. Fresh and non-pretreated rat liver cryostat sections fixed in 10% formol calcium solution and washed in distilled water were exposed to Schiff's reagent. The sections were then immersed in two baths of sodium bisulphite solution, then in water, dehydrated in ethanol, cleared in xylene and mounted in a synthetic anhydrous mounting medium. As Schiff positive areas presented well circumscribed foci which increased with time following intoxication, semiquantitative planimetric measurements were feasible. The direct Schiff's reaction detects cellular aldehydes in a sensitive, rapid histologically and topographically estimable way. The appearance of these aldehydes precedes distinctly morphological alterations detectable by other histochemical of histological techniques. No positive results were obtained in control, non-intocicated rat livers. Inhibitons of this direct Schiff's was obtained in positive control rat liver sections preincubated in solutions of aldehyde blockers. Histochemical detection of aldehydes may give useful information on different aspects of tissue and organ intoxication such as their topography, appearance, evolution, extension, consequences and effects of treatment. The direct Schiff's reaction can be considered as a valuable tool in fundamental and applied reasearch dealing with various toxicological, environmental, pathological, cancer-related and therapeutic problems.

  5. Regio- and Stereoselective Conjugate Addition of Aldehydes to β-Tosyl Enones under the Catalysis of a Binaphthyl-Modified Chiral Amine.

    Science.gov (United States)

    Kano, Taichi; Sugimoto, Hisashi; Maruyama, Hiroki; Maruoka, Keiji

    2015-07-13

    A simple axially chiral amine catalyst promoted the regio-, diastereo-, and enantioselective conjugate addition of aldehydes to β-tosyl enones, which serve as ynone surrogates. The adducts were readily converted by treatment with L-selectride into less accessible enones with a γ stereogenic center. Such compounds cannot be prepared through the amine-catalyzed conjugate addition of aldehydes to ynones. The obtained enones underwent further conjugate addition of diorganozinc compounds in the presence of a copper catalyst. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Efficient Method for Aromatic-Aldehyde Oxidation by Cleavage of Their Hydrazones Catalysed by Trimethylsilanolate

    Czech Academy of Sciences Publication Activity Database

    Bürglová, K.; Okorochenkov, S.; Buděšínský, Miloš; Hlaváč, J.

    2017-01-01

    Roč. 2017, č. 2 (2017), s. 389-396 ISSN 1434-193X R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : aldehydes * oxidation * hydrazones * solid-phase synthesis * reaction mechanisms Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.834, year: 2016

  7. Cloning and characterization of a 9-lipoxygenase gene induced by pathogen attack from Nicotiana benthamiana for biotechnological application

    Directory of Open Access Journals (Sweden)

    Schwab Wilfried

    2011-03-01

    Full Text Available Abstract Background Plant lipoxygenases (LOXs have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. In our previous study, we found that enzyme activity of endogenous 9-LOX in Nicotiana benthamiana was highly induced by agroinfiltration using a tobacco mosaic virus (TMV based vector system. Results A LOX gene which is expressed after treatment of the viral vectors was isolated from Nicotiana benthamiana. As the encoded LOX has a high amino acid identity to other 9-LOX proteins, the gene was named as Nb-9-LOX. It was heterologously expressed in yeast cells and its enzymatic activity was characterized. The yeast cells expressed large quantities of stable 9-LOX (0.9 U ml-1 cell cultures which can oxygenate linoleic acid resulting in high yields (18 μmol ml-1 cell cultures of hydroperoxy fatty acid. The product specificity of Nb-9-LOX was examined by incubation of linoleic acid and Nb-9-LOX in combination with a 13-hydroperoxide lyase from watermelon (Cl-13-HPL or a 9/13-hydroperoxide lyase from melon (Cm-9/13-HPL and by LC-MS analysis. The result showed that Nb-9-LOX possesses both 9- and 13-LOX specificity, with high predominance for the 9-LOX function. The combination of recombinant Nb-9-LOX and recombinant Cm-9/13-HPL produced large amounts of C9-aldehydes (3.3 μmol mg-1 crude protein. The yield of C9-aldehydes from linoleic acid was 64%. Conclusion The yeast expressed Nb-9-LOX can be used to produce C9-aldehydes on a large scale in combination with a HPL gene with 9-HPL function, or to effectively produce 9-hydroxy-10(E,12(Z-octadecadienoic acid in a biocatalytic process in combination with cysteine as a mild reducing agent.

  8. Heterologous Expression of Aldehyde Dehydrogenase in Lactococcus lactis for Acetaldehyde Detoxification at Low pH.

    Science.gov (United States)

    Lyu, Yunbin; LaPointe, Gisèle; Zhong, Lei; Lu, Jing; Zhang, Chong; Lu, Zhaoxin

    2018-02-01

    Aldehyde dehydrogenase (E.C. 1.2.1.x) can catalyze detoxification of acetaldehydes. A novel acetaldehyde dehydrogenase (istALDH) from the non-Saccharomyces yeast Issatchenkia terricola strain XJ-2 has been previously characterized. In this work, Lactococcus lactis with the NIsin Controlled Expression (NICE) System was applied to express the aldehyde dehydrogenase gene (istALDH) in order to catalyze oxidation of acetaldehyde at low pH. A recombinant L. lactis NZ3900 was obtained and applied for the detoxification of acetaldehyde as whole-cell biocatalysts. The activity of IstALDH in L. lactis NZ3900 (pNZ8148-istALDH) reached 36.4 U mL -1 when the recombinant cells were induced with 50 ng mL -1 nisin at 20 °C for 2 h. The IstALDH activity of recombinant L. lactis cells showed higher stability at 37 °C and pH 4.0 compared with the crude enzyme. L. lactis NZ3900 (pNZ8148-istALDH) could convert acetaldehyde at pH 2.0 while the crude enzyme could not. Moreover, the resting cells of L. lactis NZ3900 (pNZ8148-istALDH) showed a 2.5-fold higher activity and better stability in catalyzing oxidation of acetaldehyde at pH 2.0 compared with that of Escherichia coli expressing the IstALDH. Taken together, the L. lactis cells expressing recombinant IstALDH are potential whole-cell biocatalysts that can be applied in the detoxification of aldehydes.

  9. Ru/Me-BIPAM-Catalyzed Asymmetric Addition of Arylboronic Acids to Aliphatic Aldehydes and α-Ketoesters

    Directory of Open Access Journals (Sweden)

    Momoko Watanabe

    2011-06-01

    Full Text Available A ruthenium-catalyzed asymmetric arylation of aliphatic aldehydes and α-ketoesters with arylboronic acids has been developed, giving chiral alkyl(arylmethanols and α-hydroxy esters in good yields. The use of a chiral bidentate phosphoramidite ligand (Me-BIPAM achieved excellent enantioselectivities.

  10. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

    Directory of Open Access Journals (Sweden)

    Giovanna Romano

    Full Text Available Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms.

  11. Aldehyde-functionalized chitosan-montmorillonite films as dynamically-assembled, switchable-chemical release bioplastics.

    Science.gov (United States)

    Chabbi, Jamal; Jennah, Oumayma; Katir, Nadia; Lahcini, Mohamed; Bousmina, Mosto; El Kadib, Abdelkrim

    2018-03-01

    Temporal release of synergistic and/or complementary chemicals (e.g.: drugs) is recognized as extremely challenging because of their frequently intertwined kinetic delivery and presently, straightforward concepts enabling to circumvent this bottleneck are missing in the open literature. In this framework, we report herein on aldehyde-functionalized, transparent and flexible chitosan-montmorillonite hybrid films that act as a new generation of eco-friendly, controlled-chemical release bioplastics. These dynamically-assembled nanomaterials are designed by a ternary assembly from biowaste derived chitin biopolymer, aromatic aldehydes and layered clay nanoparticles. On the basis of their geometrical and conformational properties, the oxygenated groups on the grafted aromatics interact preferentially with either the base Schiff belonging to the carbohydrate (via intramolecular CNHO-Ar known as "imine clip") or with the hydroxyl groups belonging to the clay surface (via intermolecular Si-OHO-Ar). The exfoliated clay nanoparticles within the carbohydrate polymer enables either accelerating or slowing down of the imine (CN) hydrolysis depending on the interaction of the conjugated aromatics. This provides the driving force for fine tuning host-guest interactions at the molecular level and constitutes an entry toward subtle discrimination of different chemicals (e.g. complementary fertilizers, synergistic drugs) during their sequential release. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  13. Evaluation of peroxidative stress of cancer cells in vitro by real-time quantification of volatile aldehydes in culture headspace.

    Science.gov (United States)

    Shestivska, Violetta; Rutter, Abigail V; Sulé-Suso, Josep; Smith, David; Španěl, Patrik

    2017-08-30

    Peroxidation of lipids in cellular membranes results in the release of volatile organic compounds (VOCs), including saturated aldehydes. The real-time quantification of trace VOCs produced by cancer cells during peroxidative stress presents a new challenge to non-invasive clinical diagnostics, which as described here, we have met with some success. A combination of selected ion flow tube mass spectrometry (SIFT-MS), a technique that allows rapid, reliable quantification of VOCs in humid air and liquid headspace, and electrochemistry to generate reactive oxygen species (ROS) in vitro has been used. Thus, VOCs present in the headspace of CALU-1 cancer cell line cultures exposed to ROS have been monitored and quantified in real time using SIFT-MS. The CALU-1 lung cancer cells were cultured in 3D collagen to mimic in vivo tissue. Real-time SIFT-MS analyses focused on the volatile aldehydes: propanal, butanal, pentanal, hexanal, heptanal and malondialdehyde (propanedial), that are expected to be products of cellular membrane peroxidation. All six aldehydes were identified in the culture headspace, each reaching peak concentrations during the time of exposure to ROS and eventually reducing as the reactants were depleted in the culture. Pentanal and hexanal were the most abundant, reaching concentrations of a few hundred parts-per-billion by volume, ppbv, in the culture headspace. The results of these experiments demonstrate that peroxidation of cancer cells in vitro can be monitored and evaluated by direct real-time analysis of the volatile aldehydes produced. The combination of adopted methodology potentially has value for the study of other types of VOCs that may be produced by cellular damage. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

    Science.gov (United States)

    Wolfram, Stefanie; Nejstgaard, Jens C; Pohnert, Georg

    2014-01-01

    Polyunsaturated aldehydes (PUAs) are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

  15. Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

    Directory of Open Access Journals (Sweden)

    Stefanie Wolfram

    Full Text Available Polyunsaturated aldehydes (PUAs are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

  16. NMR analysis of aldehydes in Sicilian extra-virgin olive oils by DPFGSE techniques

    Directory of Open Access Journals (Sweden)

    Enrico Rotondo

    2011-03-01

    Full Text Available The DPFGSE NMR sequences open new perspectives in the volatile compounds analysis of food matrices. Many fresh extra-virgin Sicilian olive oils, analyzed by this technique, show two main resonances in the aldehydic spectral region (9–10 ppm, at 9.18 and 9.58 ppm. The former was never reported so far, the latter was sometime highlighted as a minor aldehydic component signal of spectra showing stronger resonances at 9.45 and 9.70 ppm. Thermal treatment at 220°C of extra virgin olive oil samples lead to the complete transformation of the resonances at 9.18 and 9.58 ppm into those at 9.45 and 9.70 ppm in 50 minutes. Analogous transformation takes place place in CDCl3 at rt in several weeks. These results suggest the transformation of relatively unstable compounds into thermodynamically more stable products whose resonances are commonly reported in the literature. Even though these chemical changes involve minimal amount of product, they are of crucial importance to define: i organoleptic extra virgin olive oil properties; ii fraudulent chemical or thermal treatment detection; iii extra virgin oil ageing.

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

    Directory of Open Access Journals (Sweden)

    Medina-Navarro Rafael

    2011-11-01

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

  18. "Juice Monsters": Sub-Ohm Vaping and Toxic Volatile Aldehyde Emissions.

    Science.gov (United States)

    Talih, Soha; Salman, Rola; Karaoghlanian, Nareg; El-Hellani, Ahmad; Saliba, Najat; Eissenberg, Thomas; Shihadeh, Alan

    2017-10-16

    An emerging category of electronic cigarettes (ECIGs) is sub-Ohm devices (SODs) that operate at ten or more times the power of conventional ECIGs. Because carcinogenic volatile aldehyde (VA) emissions increase sharply with power, SODs may expose users to greater VAs. In this study, we compared VA emissions from several SODs and found that across device, VAs and power were uncorrelated unless power was normalized by coil surface area. VA emissions and liquid consumed were correlated highly. Analyzed in light of EU regulations limiting ECIG liquid nicotine concentration, these findings suggest potential regulatory levers and pitfalls for protecting public health.

  19. Oxidation of N-alkyl and N-aryl azaheterocycles by free and immobilized rabbit liver aldehyde oxidase

    NARCIS (Netherlands)

    Angelino, S.A.G.F.

    1984-01-01

    Aldehyde oxidase isolated from rabbit liver is studied in this thesis with regard to its application in organic synthesis. The enzyme has a broad substrate specificity towards azaheterocycles and therefore offers great potential for profitable use.

    The oxidation of

  20. Aldehyde-functionalized porous nanocellulose for effective removal of heavy metal ions from aqueous solutions

    Science.gov (United States)

    C. Yao; F. Wang; Z. Cai; X. Wang

    2016-01-01

    Nanoscale sorption is a promising strategy for catalyst and purification system design. In this paper, cellulose nanofibrils (CNFs) were densely attached with aldehyde functional groups on the surface via a mild periodate oxidation process, and then applied as mesoporous sorbents to remove Cu(II) and Pb(II) from aqueous solutions. In the studied concentration range (0....

  1. Cystathionine γ-Lyase-Produced Hydrogen Sulfide Controls Endothelial NO Bioavailability and Blood Pressure.

    Science.gov (United States)

    Szijártó, István András; Markó, Lajos; Filipovic, Milos R; Miljkovic, Jan Lj; Tabeling, Christoph; Tsvetkov, Dmitry; Wang, Ning; Rabelo, Luiza A; Witzenrath, Martin; Diedrich, André; Tank, Jens; Akahoshi, Noriyuki; Kamata, Shotaro; Ishii, Isao; Gollasch, Maik

    2018-06-01

    Hydrogen sulfide (H 2 S) and NO are important gasotransmitters, but how endogenous H 2 S affects the circulatory system has remained incompletely understood. Here, we show that CTH or CSE (cystathionine γ-lyase)-produced H 2 S scavenges vascular NO and controls its endogenous levels in peripheral arteries, which contribute to blood pressure regulation. Furthermore, eNOS (endothelial NO synthase) and phospho-eNOS protein levels were unaffected, but levels of nitroxyl were low in CTH-deficient arteries, demonstrating reduced direct chemical interaction between H 2 S and NO. Pretreatment of arterial rings from CTH-deficient mice with exogenous H 2 S donor rescued the endothelial vasorelaxant response and decreased tissue NO levels. Our discovery that CTH-produced H 2 S inhibits endogenous endothelial NO bioavailability and vascular tone is novel and fundamentally important for understanding how regulation of vascular tone is tailored for endogenous H 2 S to contribute to systemic blood pressure function. © 2018 American Heart Association, Inc.

  2. The molecular cloning of dihydroartemisinic aldehyde reductase and its implication in artemisinin biosynthesis in Artemisia annua

    NARCIS (Netherlands)

    Ryden, A.M.; Ruyter-Spira, C.P.; Quax, W.J.; Hiroyuki, O.; Toshiya, M.; Kayser, O.; Bouwmeester, H.J.

    2010-01-01

    A key point in the biosynthesis of the antimalarial drug artemisinin is the formation of dihydroartemisinic aldehyde which represents the key difference between chemotype specific pathways. This key intermediate is the substrate for several competing enzymes, some of which increase the metabolic

  3. Reduction of Aldehydes and Ketones to Corresponding Alcohols Using Diammonium Hydrogen Phosphite and Commercial Zinc Dust

    Directory of Open Access Journals (Sweden)

    K. Anil Kumar

    2011-01-01

    Full Text Available A mild and an efficient system has been developed for the reduction of aromatic aldehydes and ketones to their corresponding alcohols in good yield using inexpensive commercial zinc dust as catalyst and diammonium hydrogen phosphite as a hydrogen donor.

  4. Curcumin loaded gum arabic aldehyde-gelatin nanogels for breast cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sarika, P.R., E-mail: sarikapaithal@gmail.com; Nirmala, Rachel James, E-mail: nirmala@iist.ac.in

    2016-08-01

    Curcumin, a widely studied hydrophobic polyphenol with anticancer potential is loaded in gum arabic aldehyde-gelatin (GA Ald-Gel) nanogels to improve its bioavailability and therapeutic efficacy towards cancer cells. Physicochemical properties of the curcumin loaded GA Ald-Gel nanogels are investigated by different techniques including dynamic light scattering (DLS), NMR spectroscopy and scanning electron microscopy (SEM). These nanogels exhibit hydrodynamic diameter of 452 ± 8 nm with a zeta potential of − 27 mV. The nanogels possess an encapsulation efficiency of 65 ± 3%. Potential of the nanogels for controlled release of curcumin is illustrated by in vitro drug release studies. Hemocompatibility and cytocompatibility of the drug loaded nanogels are evaluated. In vitro cytotoxicity of the bare and curcumin loaded nanogels are analyzed by MTT assay towards MCF-7 cells. The results manifest that curcumin loaded nanogels induce toxicity in MCF-7 cells. Confocal laser scanning microscopy (CLSM) studies indicate in vitro cellular uptake of the nanogels in MCF-7 cells. All these results prove the suitability of the curcumin loaded GA Ald-Gel nanogels for cancer therapy. - Highlights: • Curcumin loaded gum arabic aldehyde-gelatin nanogels were prepared. • Nanogels maintained negative zeta potential after curcumin loading. • Curcumin release is higher at acidic pH compared to neutral pH. • Curcumin loaded GA Ald-Gel nanogels shows toxicity towards MCF-7 cells. • Green fluorescence in MCF-7 cells confirmed the intracellular uptake.

  5. Curcumin loaded gum arabic aldehyde-gelatin nanogels for breast cancer therapy

    International Nuclear Information System (INIS)

    Sarika, P.R.; Nirmala, Rachel James

    2016-01-01

    Curcumin, a widely studied hydrophobic polyphenol with anticancer potential is loaded in gum arabic aldehyde-gelatin (GA Ald-Gel) nanogels to improve its bioavailability and therapeutic efficacy towards cancer cells. Physicochemical properties of the curcumin loaded GA Ald-Gel nanogels are investigated by different techniques including dynamic light scattering (DLS), NMR spectroscopy and scanning electron microscopy (SEM). These nanogels exhibit hydrodynamic diameter of 452 ± 8 nm with a zeta potential of − 27 mV. The nanogels possess an encapsulation efficiency of 65 ± 3%. Potential of the nanogels for controlled release of curcumin is illustrated by in vitro drug release studies. Hemocompatibility and cytocompatibility of the drug loaded nanogels are evaluated. In vitro cytotoxicity of the bare and curcumin loaded nanogels are analyzed by MTT assay towards MCF-7 cells. The results manifest that curcumin loaded nanogels induce toxicity in MCF-7 cells. Confocal laser scanning microscopy (CLSM) studies indicate in vitro cellular uptake of the nanogels in MCF-7 cells. All these results prove the suitability of the curcumin loaded GA Ald-Gel nanogels for cancer therapy. - Highlights: • Curcumin loaded gum arabic aldehyde-gelatin nanogels were prepared. • Nanogels maintained negative zeta potential after curcumin loading. • Curcumin release is higher at acidic pH compared to neutral pH. • Curcumin loaded GA Ald-Gel nanogels shows toxicity towards MCF-7 cells. • Green fluorescence in MCF-7 cells confirmed the intracellular uptake.

  6. Cyclic α-Alkoxyphosphonium Salts from (2-(Diphenylphosphino)phenyl)methanol and Aldehydes and Their Application in Synthesis of Vinyl Ethers and Ketones via Wittig Olefination.

    Science.gov (United States)

    Huang, Wenhua; Rong, Hong-Ying; Xu, Jie

    2015-07-02

    Cyclic α-alkoxyphosphonium salts have been synthesized from (2-(diphenylphosphino)phenyl)methanol and aldehydes in 36-89% yields. These phosphonium salts are bench-stable solids and undergo Wittig olefination with aldehydes under basic conditions (K2CO3 or t-BuOK) to form benzylic vinyl ethers, which are readily hydrolyzed to 1,2-disubstituted ethanones under acidic conditions. The formation mechanism of these phosphonium salts via hemiacetal is also proposed.

  7. The pectin lyase-encoding gene (pnl) family from Glomerella cingulata: characterization of pnlA and its expression in yeast.

    Science.gov (United States)

    Templeton, M D; Sharrock, K R; Bowen, J K; Crowhurst, R N; Rikkerink, E H

    1994-05-03

    Oligodeoxyribonucleotide primers were designed from conserved amino acid (aa) sequences between pectin lyase D (PNLD) from Aspergillus niger and pectate lyases A and E (PELA/E) from Erwinia chrysanthemi. The polymerase chain reaction (PCR) was used with these primers to amplify genomic DNA from the plant pathogenic fungus Glomerella cingulata. Three different 220-bp fragments with homology to PNL-encoding genes from A. niger, and a 320-bp fragment with homology to PEL-encoding genes from Nicotiana tabacum and E. carotovora were cloned. One of the 220-bp PCR products (designated pnlA) was used as a probe to isolate a PNL-encoding gene from a lambda genomic DNA library prepared from G. cingulata. Nucleotide (nt) sequence data revealed that this gene has seven exons and codes for a putative 380-aa protein. The nt sequence of a cDNA clone, prepared using PCR, confirmed the presence of the six introns. The positions of the introns were different from the sites of the five introns present in the three PNL-encoding genes previously sequenced from A. niger. PNLA was synthesised in yeast by cloning the cDNA into the expression vector, pEMBLYex-4, and enzymatically active protein was secreted into the culture medium. Significantly higher expression was achieved when the context of the start codon, CACCATG, was mutated to CAAAATG, a consensus sequence commonly found in highly expressed yeast genes. The produced protein had an isoelectric point (pI) of 9.4, the same as that for the G. cingulata pnlA product.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. YKL071W from Saccharomyces cerevisiae encodes a novel aldehyde reductase for detoxification of glycolaldehyde and furfural derived from lignocellulose.

    Science.gov (United States)

    Wang, Hanyu; Ouyang, Yidan; Zhou, Chang; Xiao, Difan; Guo, Yaping; Wu, Lan; Li, Xi; Gu, Yunfu; Xiang, Quanju; Zhao, Ke; Yu, Xiumei; Zou, Likou; Ma, Menggen

    2017-12-01

    Aldehydes generated as by-products during the pretreatment of lignocellulose are the key inhibitors to Saccharomyces cerevisiae, which is considered as the most promising microorganism for industrial production of biofuel, xylitol as well as other special chemicals from lignocellulose. S. cerevisiae has the inherent ability to in situ detoxify aldehydes to corresponding alcohols by multiple aldehyde reductases. Herein, we report that an uncharacterized open reading frame YKL071W from S. cerevisiae encodes a novel "classical" short-chain dehydrogenase/reductase (SDR) protein with NADH-dependent enzymatic activities for reduction of furfural (FF), glycolaldehyde (GA), formaldehyde (FA), and benzaldehyde (BZA). This enzyme showed much better specific activities for reduction of GA and FF than FA and BZA, and displayed much higher Km and Kcat/Km but lower Vmax and Kcat for reduction of GA than FF. For this enzyme, the optimum pH was 5.5 and 6.0 for reduction of GA and FF, and the optimum temperature was 30 °C for reduction of GA and FF. Both pH and temperature affected stability of this enzyme in a similar trend for reduction of GA and FF. Cu 2+ , Zn 2+ , Ni 2+ , and Fe 3+ had severe inhibition effects on enzyme activities of Ykl071wp for reduction of GA and FF. Transcription of YKL071W in S. cerevisiae was significantly upregulated under GA and FF stress conditions, and its transcription is most probably regulated by transcription factor genes of YAP1, CAD1, PDR3, and STB5. This research provides guidelines to identify more uncharacterized genes with reductase activities for detoxification of aldehydes derived from lignocellulose in S. cerevisiae.

  9. Genomic Characterization of Phenylalanine Ammonia Lyase Gene in Buckwheat.

    Directory of Open Access Journals (Sweden)

    Karthikeyan Thiyagarajan

    Full Text Available Phenylalanine Ammonia Lyase (PAL gene which plays a key role in bio-synthesis of medicinally important compounds, Rutin/quercetin was sequence characterized for its efficient genomics application. These compounds possessing anti-diabetic and anti-cancer properties and are predominantly produced by Fagopyrum spp. In the present study, PAL gene was sequenced from three Fagopyrum spp. (F. tataricum, F. esculentum and F. dibotrys and showed the presence of three SNPs and four insertion/deletions at intra and inter specific level. Among them, the potential SNP (position 949th bp G>C with Parsimony Informative Site was selected and successfully utilised to individuate the zygosity/allelic variation of 16 F. tataricum varieties. Insertion mutations were identified in coding region, which resulted the change of a stretch of 39 amino acids on the putative protein. Our Study revealed that autogamous species (F. tataricum has lower frequency of observed SNPs as compared to allogamous species (F. dibotrys and F. esculentum. The identified SNPs in F. tataricum didn't result to amino acid change, while in other two species it caused both conservative and non-conservative variations. Consistent pattern of SNPs across the species revealed their phylogenetic importance. We found two groups of F. tataricum and one of them was closely related with F. dibotrys. Sequence characterization information of PAL gene reported in present investigation can be utilized in genetic improvement of buckwheat in reference to its medicinal value.

  10. Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1.

    Directory of Open Access Journals (Sweden)

    Silvia Schumann

    Full Text Available Mouse aldehyde oxidase (mAOX1 forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Escherichia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.

  11. The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 gene encodes an aldehyde dehydrogenase involved in ferulic acid and sinapic acid biosynthesis.

    Science.gov (United States)

    Nair, Ramesh B; Bastress, Kristen L; Ruegger, Max O; Denault, Jeff W; Chapple, Clint

    2004-02-01

    Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP(+)-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. Consistent with this finding, extracts of ref1 leaves exhibit low sinapaldehyde dehydrogenase activity. These data indicate that REF1 encodes a sinapaldehyde dehydrogenase required for sinapic acid and sinapate ester biosynthesis. When expressed in Escherichia coli, REF1 was found to exhibit both sinapaldehyde and coniferaldehyde dehydrogenase activity, and further phenotypic analysis of ref1 mutant plants showed that they contain less cell wall-esterified ferulic acid. These findings suggest that both ferulic acid and sinapic acid are derived, at least in part, through oxidation of coniferaldehyde and sinapaldehyde. This route is directly opposite to the traditional representation of phenylpropanoid metabolism in which hydroxycinnamic acids are instead precursors of their corresponding aldehydes.

  12. Association of air pollution sources and aldehydes with biomarkers of blood coagulation, pulmonary inflammation, and systemic oxidative stress.

    Science.gov (United States)

    Altemose, Brent; Robson, Mark G; Kipen, Howard M; Ohman Strickland, Pamela; Meng, Qingyu; Gong, Jicheng; Huang, Wei; Wang, Guangfa; Rich, David Q; Zhu, Tong; Zhang, Junfeng

    2017-05-01

    Using data collected before, during, and after the 2008 Summer Olympic Games in Beijing, this study examines associations between biomarkers of blood coagulation (vWF, sCD62P and sCD40L), pulmonary inflammation (EBC pH, EBC nitrite, and eNO), and systemic oxidative stress (urinary 8-OHdG) with sources of air pollution identified utilizing principal component analysis and with concentrations of three aldehydes of health concern. Associations between the biomarkers and the air pollution source types and aldehydes were examined using a linear mixed effects model, regressing through seven lag days and controlling for ambient temperature, relative humidity, gender, and day of week for the biomarker measurements. The biomarkers for pulmonary inflammation, particularly EBC pH and eNO, were most consistently associated with vehicle and industrial combustion, oil combustion, and vegetative burning. The biomarkers for blood coagulation, particularly vWF and sCD62p, were most consistently associated with oil combustion. Systemic oxidative stress biomarker (8-OHdG) was most consistently associated with vehicle and industrial combustion. The associations of the biomarkers were generally not significant or consistent with secondary formation of pollutants and with the aldehydes. The findings support policies to control anthropogenic pollution sources rather than natural soil or road dust from a cardio-respiratory health standpoint.

  13. YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

    Science.gov (United States)

    Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

    2015-05-01

    Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed. Copyright © 2015 John Wiley & Sons, Ltd.

  14. An acidic pectin lyase from Aspergillus niger with favourable efficiency in fruit juice clarification.

    Science.gov (United States)

    Xu, S X; Qin, X; Liu, B; Zhang, D Q; Zhang, W; Wu, K; Zhang, Y H

    2015-02-01

    The pectin lyase gene pnl-zj5a from Aspergillus niger ZJ5 was identified and expressed in Pichia pastoris. PNL-ZJ5A was purified by ultrafiltration, anion exchange and gel chromatography. The Km and Vmax values determined using citrus pectin were 0.66 mg ml(-1) and 32.6 μmol min(-1) mg(-1) , respectively. PNL-ZJ5A exhibited optimal activity at 43°C and retained activity over 25-50°C. PNL-ZJ5A was optimally active at pH 5 and effective in apple juice clarification. Compared with controls, PNL-ZJ5A increased the fruit juice yield significantly. Furthermore, PNL-ZJ5A reduced the viscosity of apple juice by 38.8% and increased its transmittance by 86.3%. PNL-ZJ5A combined with a commercial pectin esterase resulted in higher juice volume. © 2014 The Society for Applied Microbiology.

  15. Phenylalanine ammonia lyase catalyzed synthesis of amino acids by an MIO-cofactor independent pathway.

    Science.gov (United States)

    Lovelock, Sarah L; Lloyd, Richard C; Turner, Nicholas J

    2014-04-25

    Phenylalanine ammonia lyases (PALs) belong to a family of 4-methylideneimidazole-5-one (MIO) cofactor dependent enzymes which are responsible for the conversion of L-phenylalanine into trans-cinnamic acid in eukaryotic and prokaryotic organisms. Under conditions of high ammonia concentration, this deamination reaction is reversible and hence there is considerable interest in the development of PALs as biocatalysts for the enantioselective synthesis of non-natural amino acids. Herein the discovery of a previously unobserved competing MIO-independent reaction pathway, which proceeds in a non-stereoselective manner and results in the generation of both L- and D-phenylalanine derivatives, is described. The mechanism of the MIO-independent pathway is explored through isotopic-labeling studies and mutagenesis of key active-site residues. The results obtained are consistent with amino acid deamination occurring by a stepwise E1 cB elimination mechanism. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Purification, molecular cloning, and expression of 2-hydroxyphytanoyl- CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon-carbon bond cleavage during à-oxidation of 3- methyl-branched fatty acids

    CERN Document Server

    Foulon, V; Croes, K; Waelkens, E

    1999-01-01

    Purification, molecular cloning, and expression of 2-hydroxyphytanoyl- CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon-carbon bond cleavage during à-oxidation of 3- methyl-branched fatty acids

  17. Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids

    DEFF Research Database (Denmark)

    Kryshtal, G. V.; Zhdankina, G. M.; Astakhova, Irina Kira

    2004-01-01

    Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3......- methylimidazolium hexafluorophosphate [bmim][PF 6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields...

  18. Solvent Isotope-induced Equilibrium Perturbation for Isocitrate Lyase

    Science.gov (United States)

    Quartararo, Christine E.; Hadi, Timin; Cahill, Sean M.; Blanchard, John S.

    2014-01-01

    Isocitrate lyase (ICL) catalyzes the reversible retro-aldol cleavage of isocitrate to generate glyoxylate and succinate. ICL is the first enzyme of the glyoxylate shunt, which allows for the anaplerosis of citric acid cycle intermediates under nutrient limiting conditions. In Mycobacterium tuberculosis, the source of ICL for these studies, ICL is vital for the persistence phase of the bacteria’s life cycle. Solvent kinetic isotope effects (KIEs) in the direction of isocitrate cleavage of D2OV = 2.0 ± 0.1 and D2O[V/Kisocitrate] = 2.2 ± 0.3 arise from the initial deprotonation of the C2 hydroxyl group of isocitrate or the protonation of the aci-acid of succinate product of the isocitrate aldol cleavage by a solvent-derived proton. This KIE suggested that an equilibrium mixture of all protiated isocitrate, glyoxylate and succinate prepared in D2O, would undergo transient changes in equilibrium concentrations as a result of the solvent KIE and solvent-derived deuterium incorporation into both succinate and isocitrate. No change in the isotopic composition of glyoxylate was expected or observed. We have directly monitored the changing concentrations of all isotopic species of all reactants and products using a combination of NMR spectroscopy and mass spectrometry. Continuous monitoring of glyoxylate by 1H NMR spectroscopy shows a clear equilibrium perturbation in D2O. The final equilibrium isotopic composition of reactants in D2O revealed di-deuterated succinate, protiated glyoxylate, and mono-deuterated isocitrate, with the transient appearance and disappearance of mono-deuterated succinate. A model for the equilibrium perturbation of substrate species, and their time-dependent isotopic composition is presented. PMID:24261638

  19. aldB, an RpoS-dependent gene in Escherichia coli encoding an aldehyde dehydrogenase that is repressed by Fis and activated by Crp.

    OpenAIRE

    Xu, J; Johnson, R C

    1995-01-01

    Escherichia coli aldB was identified as a gene that is negatively regulated by Fis but positively regulated by RpoS. The complete DNA sequence determined in this study indicates that aldB encodes a 56.3-kDa protein which shares a high degree of homology with an acetaldehyde dehydrogenase encoded by acoD of Alcaligenes eutrophus and an aldehyde dehydrogenase encoded by aldA of Vibrio cholerae and significant homology with a group of other aldehyde dehydrogenases from prokaryotes and eukaryotes...

  20. Expressional studies of the aldehyde oxidase (AOX1) gene during myogenic differentiation in C2C12 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kamli, Majid Rasool; Kim, Jihoe; Pokharel, Smritee; Jan, Arif Tasleem [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Lee, Eun Ju [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Choi, Inho, E-mail: inhochoi@ynu.ac.kr [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

    2014-08-08

    Highlights: • AOX1 contributes to the formation of myotube. • Silencing of AOX1 reduces myotube formation. • AOX1 regulates MyoG gene expression. • AOX1 contributes to myogenesis via H{sub 2}O{sub 2}. - Abstract: Aldehyde oxidases (AOXs), which catalyze the hydroxylation of heterocycles and oxidation of a wide variety of aldehydic compounds, have been present throughout evolution from bacteria to humans. While humans have only a single functional aldehyde oxidase (AOX1) gene, rodents are endowed with four AOXs; AOX1 and three aldehyde oxidase homologs (AOH1, AOH2 and AOH3). In continuation of our previous study conducted to identify genes differentially expressed during myogenesis using a microarray approach, we investigated AOX1 with respect to its role in myogenesis to conceptualize how it is regulated in C2C12 cells. The results obtained were validated by silencing of the AOX1 gene. Analysis of their fusion index revealed that formation of myotubes showed a marked reduction of up to 40% in AOX1{sub kd} cells. Expression of myogenin (MYOG), one of the marker genes used to study myogenesis, was also found to be reduced in AOX1{sub kd} cells. AOX1 is an enzyme of pharmacological and toxicological importance that metabolizes numerous xenobiotics to their respective carboxylic acids. Hydrogen peroxide (H{sub 2}O{sub 2}) produced as a by-product in this reaction is considered to be involved as a part of the signaling mechanism during differentiation. An observed reduction in the level of H{sub 2}O{sub 2} among AOX1{sub kd} cells confirmed production of H{sub 2}O{sub 2} in the reaction catalyzed by AOX1. Taken together, these findings suggest that AOX1 acts as a contributor to the process of myogenesis by influencing the level of H{sub 2}O{sub 2}.

  1. Exposure to polycyclic aromatic hydrocarbons (PAHs), mutagenic aldehydes and particulate matter during pan frying of beefsteak.

    Science.gov (United States)

    Sjaastad, Ann Kristin; Jørgensen, Rikke Bramming; Svendsen, Kristin

    2010-04-01

    Cooking with gas or electric stoves produces fumes, especially during frying, that contain a range of harmful and potentially mutagenic compounds as well as high levels of fine and ultrafine particles. The aim of this study was to see if polycyclic aromatic hydrocarbons (PAHs) and higher mutagenic aldehydes which were collected in the breathing zone of the cook, could be detected in fumes from the frying of beefsteak. The frying was performed in a model kitchen in conditions similar to those in a Western European restaurant kitchen. The levels of PAHs (16 EPA standard) and higher aldehydes (trans,trans-2,4-decadienal, 2,4-decadienal, trans-trans-2,4-nonadienal, trans-2-decenal, cis-2-decenal, trans-2-undecenal, 2-undecenal) were measured during frying on an electric or gas stove with margarine or soya bean oil as the frying fat. The number concentration of particles electric stove causes increased occupational exposure to some of the components in cooking fumes which may cause adverse health effects.

  2. Kinetics of the reactions of bromine atoms with a series of aliphatic aldehydes at 298 K

    Energy Technology Data Exchange (ETDEWEB)

    Szilagyi, I.; Imrik, K.; Dobe, S.; Berces, T. [Magyar Tudomanyos Akademia, Budapest (Hungary). Koezponti Kemiai Kutato Intezete

    1998-01-01

    The kinetics of the reactions of Br({sup 2}P{sub 3/2}) with selected aldehydes, i.e. ethanal (1), propanal (2), 2-methyl-propanal (3), 2.2-dimethyl-propanal (4) and trichloroacetaldehyde (5) were studied at 298{+-}2 K. Rate constants for overall reactions were measured using the fast flow technique with resonance fluorescence detection of Br. Complementary determinations were carried out by the laser flash photolysis method. The following rate constants were obtained in the kinetic measurements ({+-}2{sigma}): k{sub 1}=(2.1{+-}0.2) x 10{sup 12}, k{sub 2}=(4.3{+-}0.4) x 10{sup 12}, k{sub 3}=(6.3{+-}1.4) x 10{sup 12}, k{sub 4}=(8.5{+-}0.8) x 10{sup 12}, k{sub 5}{<=}1 x 10{sup 9}, all in cm{sup 3}mol{sup -1}s{sup -1} units. The probable mechanism for the reactions of bromine atoms with aliphatic aldehydes has been discussed. (orig.)

  3. Corneal aldehyde dehydrogenase and glutathione S-transferase activity after excimer laser keratectomy in guinea pigs.

    Science.gov (United States)

    Bilgihan, K; Bilgihan, A; Hasanreisoğlu, B; Turkozkan, N

    1998-03-01

    The free radical balance of the eye may be changed by excimer laser keratectomy. Previous studies have demonstrated that excimer laser keratectomy increases the corneal temperature, decreases the superoxide dismutase activity of the aqueous, and induces lipid peroxidation in the superficial corneal stroma. Aldehyde dehydrogenase (ALDH) and glutathione S-transferase (GST) are known to play an important role in corneal metabolism, particularly in detoxification of aldehydes, which are generated from free radical reactions. In three groups of guinea pigs mechanical corneal de-epithelialisation was performed in group I, superficial corneal photoablation in group II, and deep corneal photoablation in group III, and the corneal ALDH and GST activities measured after 48 hours. The mean ALDH and GST activities of group I and II showed no differences compared with the controls (p > 0.05). The corneal ALDH activities were found to be significantly decreased (p < 0.05) and GST activities increased (p < 0.05) in group III. These results suggest that excimer laser treatment of high myopia may change the ALDH and GST activities, metabolism, and free radical balance of the cornea.

  4. Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

    Directory of Open Access Journals (Sweden)

    Xacobe C. Cambeiro

    2011-10-01

    Full Text Available The application of polystyrene-immobilized proline-based catalysts in packed-bed reactors for the continuous-flow, direct, enantioselective α-aminoxylation of aldehydes is described. The system allows the easy preparation of a series of β-aminoxy alcohols (after a reductive workup with excellent optical purity and with an effective catalyst loading of ca. 2.5% (four-fold reduction compared to the batch process working at residence times of ca. 5 min.

  5. Phenolic Acids, Phenolic Aldehydes and Furanic Derivatives in Oak Chips: American vs. French Oaks

    OpenAIRE

    Cabrita, M.J.; Barrocas Dias, C.; Costa Freitas, A.M.

    2011-01-01

    Phenolic acids (gallic, vanillic, syringic and ellagic acids), phenolic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and furanic derivatives (furfural, 5-methylfurfural and 5-hydroxymethylfurfural) were quantified in commercial American and French oak chips. Chips with different sizes and toast degrees were used. Compounds were extracted directly from the wood samples in order to determine possible differences among woods as well as toast degree. Likewise, the compo...

  6. Gene deletion of cytosolic ATP: citrate lyase leads to altered organic acid production in Aspergillus niger

    DEFF Research Database (Denmark)

    Meijer, Susan Lisette; Nielsen, Michael Lynge; Olsson, Lisbeth

    2009-01-01

    With the availability of the genome sequence of the filamentous fungus Aspergillus niger, the use of targeted genetic modifications has become feasible. This, together with the fact that A. niger is well established industrially, makes this fungus an attractive micro-organism for creating a cell...... factory platform for production of chemicals. Using molecular biology techniques, this study focused on metabolic engineering of A. niger to manipulate its organic acid production in the direction of succinic acid. The gene target for complete gene deletion was cytosolic ATP: citrate lyase (acl), which...... the acl gene. Additionally, the total amount of organic acids produced in the deletion strain was significantly increased. Genome-scale stoichiometric metabolic model predictions can be used for identifying gene targets. Deletion of the acl led to increased succinic acid production by A. niger....

  7. A Pectate Lyase-Coding Gene Abundantly Expressed during Early Stages of Infection Is Required for Full Virulence in Alternaria brassicicola.

    Directory of Open Access Journals (Sweden)

    Yangrae Cho

    Full Text Available Alternaria brassicicola causes black spot disease of Brassica species. The functional importance of pectin digestion enzymes and unidentified phytotoxins in fungal pathogenesis has been suspected but not verified in A. brassicicola. The fungal transcription factor AbPf2 is essential for pathogenicity and induces 106 genes during early pathogenesis, including the pectate lyase-coding gene, PL1332. The aim of this study was to test the importance and roles of PL1332 in pathogenesis. We generated deletion strains of the PL1332 gene, produced heterologous PL1332 proteins, and evaluated their association with virulence. Deletion strains of the PL1332 gene were approximately 30% less virulent than wild-type A. brassicicola, without showing differences in colony expansion on solid media and mycelial growth in nutrient-rich liquid media or minimal media with pectins as a major carbon source. Heterologous PL1332 expressed as fusion proteins digested polygalacturons in vitro. When the fusion proteins were injected into the apoplast between leaf veins of host plants the tissues turned dark brown and soft, resembling necrotic leaf tissue. The PL1332 gene was the first example identified as a general toxin-coding gene and virulence factor among the 106 genes regulated by the transcription factor, AbPf2. It was also the first gene to have its functions investigated among the 19 pectate lyase genes and several hundred putative cell-wall degrading enzymes in A. brassicicola. These results further support the importance of the AbPf2 gene as a key pathogenesis regulator and possible target for agrochemical development.

  8. Synthesis of specifically labelled L-phenylalanines using phenylalanine ammonia lyase activity

    International Nuclear Information System (INIS)

    Haedener, A.; Tamm, Ch.

    1987-01-01

    Specifically labelled L-phenylalanines have been prepared using a variety of classical synthetic methods in combination with phenylalanine ammonia lyase (PAL) enzyme activity of the yeast Rhodosporidium toruloides ATCC 10788 or Rhodotorula glutinis IFO 0559, respectively. Thus, L-[2- 2 H]phenyl-[2- 2 H]alanine was formed from (E) -[2,2'- 2 H 2 ]cinnamic acid and ammonia in 46% yield, whereas L-phenyl-[2- 13 C, 15 N]alanine was obtained from (E)-[2- 13 C]cinnamic acid in 45% overall yield. Generally, labelled cinnamic acids were recovered in pure form from the reaction mixture, with a loss of 6-8%. Likewise, unchanged 15 NH 3 was reisolated as 15 NH 4 Cl after steam distillation with overall losses of less than 4%. Labelled cinnamic acids were prepared by Knoevenagel condensations between appropriately labelled benzaldehydes and malonic acids. [2- 2 H]Benzaldehyde was obtained from 2-bromotoluene by decomposition of the corresponding Grignard reagent with 2 H 2 O and subsequent oxidation. Since simple molecules, most of them commercially available in labelled form or otherwise easily accessible, may serve as starting material, and due to its defined stereochemistry, the reaction catalysed by PAL opens a short and attractive route to specifically labelled L-phenylalanines. (author)

  9. Paraffin as oxygen vector modulates tyrosine phenol lyase production by Citrobacter freundii MTCC 2424.

    Science.gov (United States)

    Azmi, Wamik; Kumar, Ajay; Dev, Varun

    2013-06-01

    The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of tyrosine phenol lyase (TPL) by Citrobacter freundii MTCC 2424 was evaluated at 4% (v/v) concentration. The liquid paraffin as oxygenvectors was found to exhibit a stimulatory effect on TPL synthesis. The liquid paraffin at 6% (v/v) resulted in 34% increase in the TPL synthesis accompanied by a 13% increase in the production of cell mass at a 10 L scale. This improvement in TPL and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% throughout the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhanced synthesis of TPL and cell mass.

  10. High-performance liquid chromatography-fluorescence assay of pyruvic acid to determine cysteine conjugate beta-lyase activity : application to S-1,2-dichlorovinyl-L-cysteine and S-2-benzothiazolyl-L-cysteine

    NARCIS (Netherlands)

    Stijntjes, G.J.; te Koppele, J.M.; Vermeulen, N P

    1992-01-01

    An HPLC-fluorescence assay has been developed for the determination of the activity of rat renal cytosolic cysteine conjugate beta-lyase. The method is based on isocratic HPLC separation and fluorescence detection of pyruvic acid, derivatized with o-phenylenediamine (OPD), and is shown to be rapid,

  11. Aldehyded Dextran and ε-Poly(L-lysine Hydrogel as Nonviral Gene Carrier

    Directory of Open Access Journals (Sweden)

    Yumiko Togo

    2013-01-01

    Full Text Available Background. The expression term of the gene transfected in cells needs to belong enough inorder to make a gene therapy clinically effective. The controlled release of the transfected gene can be utilized. The new biodegradable hydrogel material created by 20 w/w% aldehyded dextran and 10 w/w% ε-poly(L-lysine (ald-dex/PLL was developed. We examined whether it could be as a nonviral carrier of the gene transfer. Methods. A plasmid (Lac-Z was mixed with ald-dex/PLL. An in vitro study was performed to assess the expression of Lac-Z with X-gal stain after gene transfer into the cultured 293 cells and bone marrow cells. As a control group, PLL was used as a cationic polymer. Results. We confirmed that the transfection efficiency of the ald-dex/PLL had a higher transfection efficiency than PLL in 293 cells (plasmid of 2 μg: ald-dex/PLL 1.1%, PLL 0.23%, plasmid of 16 μg: ald-dex/PLL 1.23%, PLL 0.48%. In bone marrow cells, we confirmed the expression of Lac-Z by changing the quantity of aldehyded dextran. In the groups using ald-dextran of the quantity of 1/4 and 1/12 of PLL, their transfection efficiency was 0.43% and 0.41%, respectively. Conclusions. This study suggested a potential of using ald-dex/PLL as a non-carrier for gene transfer.

  12. Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils

    Science.gov (United States)

    Duerr, Mark A.; Aurora, Rajeev; Ford, David A.

    2015-01-01

    α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-labeled [d4]HDA-GSH was synthesized, which further confirmed the structure, and was used to quantify natural α-ClFALD conjugates of GSH (FALD-GSH) using reverse-phase LC with detection by ESI/MS/MS using selected reaction monitoring. HDA-GSH is elevated in RAW 264.7 cells treated with physiologically relevant concentrations of exogenous 2-ClHDA. Furthermore, PMA-treated primary human neutrophils have elevated levels of HDA-GSH and the conjugate of 2-chlorooctadecanal (2-ClODA) and GSH (ODA-GSH), as well as elevated levels of 2-ClHDA and 2-ClODA. Production of both conjugates in PMA-stimulated neutrophils was reduced by 3-aminotriazole pretreatment, which also blocks endogenous α-ClFALD production. Additionally, plasma FALD-GSH levels were elevated in the K/BxN mouse arthritis model. Taken together, these studies demonstrate novel peptidoaldehydes derived from GSH and α-ClFALD in activated human neutrophils and in vivo in K/BxN mice. PMID:25814023

  13. Liquid chromatography-dopant-assisted atmospheric pressure photoionization-mass spectrometry: Application to the analysis of aldehydes in atmospheric aerosol particles.

    Science.gov (United States)

    Ruiz-Jiménez, José; Hautala, Sanna; Parshintsev, Jevgeni; Laitinen, Totti; Hartonen, Kari; Petäjä, Tuukka; Kulmala, Markku; Riekkola, Marja-Liisa

    2013-01-01

    A complete methodology based on LC-anisole-toluene dopant-assisted atmospheric pressure photoionization-IT-MS was developed for the determination of aldehydes in atmospheric aerosol particles. For the derivatization, ultrasound was used to accelerate the reaction between the target analytes and 2,4-dinitrophenylhydrazine. The developed methodology was validated for three different samples, gas phase, ultrafine (Dp = 30 ± 4 nm; where Dp stands for particle diameter) and all-sized particles, collected on Teflon filters. The method quantitation limits ranged from 5 to 227 pg. The accuracy and the potential matrix effects were evaluated using standard addition methodology. Recoveries ranged between 91.7 and 109.9%, and the repeatability and the reproducibility of the method developed between 0.5 and 8.0% and between 2.9 and 11.1%, respectively. The results obtained by the developed methodology compared to those provided by the previously validated method revealed no statistical differences. The method developed was applied to the determination of aldehydes in 16 atmospheric aerosol samples (30 nm and all-sized samples) collected at the Station for Measuring Forest Ecosystem-Atmosphere Relations II during spring 2011. The mean concentrations of aldehydes, and oxidation products of terpenes were between 0.05 and 82.70 ng/m(3). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Molecular Cloning and Sequence Analysis of a Phenylalanine Ammonia-Lyase Gene from Dendrobium

    Science.gov (United States)

    Cai, Yongping; Lin, Yi

    2013-01-01

    In this study, a phenylalanine ammonia-lyase (PAL) gene was cloned from Dendrobium candidum using homology cloning and RACE. The full-length sequence and catalytic active sites that appear in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum are also found: PAL cDNA of D. candidum (designated Dc-PAL1, GenBank No. JQ765748) has 2,458 bps and contains a complete open reading frame (ORF) of 2,142 bps, which encodes 713 amino acid residues. The amino acid sequence of DcPAL1 has more than 80% sequence identity with the PAL genes of other plants, as indicated by multiple alignments. The dominant sites and catalytic active sites, which are similar to that showing in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum, are also found in DcPAL1. Phylogenetic tree analysis revealed that DcPAL is more closely related to PALs from orchidaceae plants than to those of other plants. The differential expression patterns of PAL in protocorm-like body, leaf, stem, and root, suggest that the PAL gene performs multiple physiological functions in Dendrobium candidum. PMID:23638048

  15. Characterization of a new (R)-hydroxynitrile lyase from the Japanese apricot Prunus mume and cDNA cloning and secretory expression of one of the isozymes in Pichia pastoris.

    Science.gov (United States)

    Fukuta, Yasuhisa; Nanda, Samik; Kato, Yasuo; Yurimoto, Hiroya; Sakai, Yasuyoshi; Komeda, Hidenobu; Asano, Yasuhisa

    2011-01-01

    PmHNL, a hydroxynitrile lyase from Japanese apricot ume (Prunus mume) seed was purified to homogeneity by ammonium sulfate fractionation and chromatographic steps. The purified enzyme was a monomer with molecular mass of 58 kDa. It was a flavoprotein similar to other hydroxynitrile lyases of the Rosaceae family. It was active over a broad temperature, and pH range. The N-terminal amino acid sequence (20 amino acids) was identical with that of the enzyme from almond (Prunus dulcis). Based on the N-terminal sequence of the purified enzyme and the conserved amino acid sequences of the enzymes from Pr. dulcis, inverse PCR method was used for cloning of a putative PmHNL (PmHNL2) gene from a Pr. mume seedling. Then the cDNA for the enzyme was cloned. The deduced amino acid sequence was found to be highly similar (95%) to that of an enzyme from Pr. serotina, isozyme 2. The recombinant Pichia pastoris transformed with the PmHNL2 gene secreted an active enzyme in glycosylated form.

  16. Determination of Aldehyde Dehydrogenase (ALDH Isozymes in Human Cancer Samples - Comparison of Kinetic and Immunochemical Assays

    Directory of Open Access Journals (Sweden)

    Dorota Borecka

    2002-12-01

    Full Text Available A fluorimetric assay of aldehyde dehydrogenase isozymes, based on naphthaldehyde oxidation, is compared with Western Blotting analysis on several clinical samples obtained from surgery. The comparison reveals qualitatively good correlation of ALDH1A1 isozyme detection with two methods and somewhat worse on ALDH3A1 assay.

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

    Science.gov (United States)

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

    1980-10-21

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

  18. HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR DETERMINATION OF AROMATIC ALDEHYDES IN WINE DISTILLATES

    Directory of Open Access Journals (Sweden)

    Elena Nezalzova

    2011-06-01

    Full Text Available Quality control of alcoholic beverages, coming into the market, is a defining element in preventing the production and supplying of defective products. One of the main criteria for quality control of wine distillates is to estimate their age, and more precisely the period of maturation as the dominant factor in determining the quality of cognacs and, consequently, their market price. On the opinion of majority scientists, one of the main factors, which determines the age of wine distillates, is the content of aromatic aldehydes, mostly vanillin, and their ratio.

  19. Synthesis of non-natural carbohydrates from glycerol and aldehydes in a one-pot four-enzyme cascade reaction

    NARCIS (Netherlands)

    Babich, L.; Hartog, L.; Falcicchio, P.; Oost, van der J.

    2011-01-01

    A simple procedure has been developed for the synthesis of enantio- and diastereomerically pure carbohydrate analogues from glycerol and a variety of aldehydes in one pot using a four-enzyme cascade reaction. As a proof of concept of the usefulness of this enzymatic catalytic cascade the naturally

  20. Ionic liquids as recyclable and separable reaction media in Rh-catalyzed decarbonylation of aromatic and aliphatic aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    Ionic liquids (ILs) have been applied as recyclable reaction media in the decarbonylation of aldehydes in the presence of a rhodium-phosphine complex catalyst. The performance of several new catalytic systems based on imidazolium-based ILs and [Rh(dppp)2]Cl (dppp: 1,3-diphenylphosphinopropane) were...

  1. Suppressed phenylalanine ammonia-lyase activity after heat shock in transgenic Nicotiana plumbaginifolia containing an Arabidopsis HSP18.2-parsley PAL2 chimera gene.

    Science.gov (United States)

    Moriwaki, M; Yamakawa, T; Washino, T; Kodama, T; Igarashi, Y

    1999-01-01

    The activity of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) after heat shock (HS) in leaves and buds of transgenic Nicotiana plumbaginifolia containing an Arabidopsis HSP18.2 promoter-parsley phenylalanine ammonia-lyase 2 (HSP18.2-PAL2) chimera gene was examined. Immediately after HS treatment at 44 degrees C for 5 h, the PAL activity in both transgenic and normal (untransformed) plants was 35-38% lower than that before HS. At normal temperature (25-26 degrees C), the PAL activity recovered within 5 h of ending the HS treatment in normal plants, but not until 12-24 h in transgenic plants containing the HSP18.2-PAL2 gene. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of parsley PAL2 mRNA in transgenic plants, which remained for 8-12 h following 5-h HS at 44 degrees C; the mRNA was not observed before HS. The content of chlorogenic acid (CGA; 3-caffeoylquinic acid) decreased drastically 8-12 h after HS in transgenic plants, but only slightly in normal plants. Thus, the decrease in PAL activity accompanied by expression of the parsley PAL2 gene after HS treatment corresponded to the decrease in CGA synthesis. These results might be attributed to post-transcriptional degradation of endogenous PAL mRNA triggered by transcription of the transgene.

  2. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

    International Nuclear Information System (INIS)

    Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

    2014-01-01

    Highlights: • Mo 2 C surface can deoxygenate propanal and 1-propanol to produce propene through a similar intermediate (propoxide or η 2 (C,O)-propanal). • Mo 2 C surface can deoxygenate furfural and furfuryl alcohol to make 2-methylfuran through a 2-methylfuran-like intermediate. • The presence of furan ring modifies the selectivity between deoxygenation and hydrogenation/dehydrogenation pathways. - Abstract: The selective deoxygenation of aldehydes and alcohols without cleaving the C-C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo 2 C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η 2 (C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo 2 C, as well as the effect of the furan ring on the selective deoxygenation of the C=O and C-OH bonds

  3. Glu504Lys Single Nucleotide Polymorphism of Aldehyde Dehydrogenase 2 Gene and the Risk of Human Diseases

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2015-01-01

    Full Text Available Aldehyde dehydrogenase (ALDH 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotide polymorphism (SNP of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer’s disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations.

  4. Structure of products of the condensation of α,β-unsaturated aldehydes with dimedone

    International Nuclear Information System (INIS)

    Yurchenko, O.I.; Pushkareva, K.S.; Zheldubovskaya, G.A.; Komarov, N.V.; Berkova, G.A.

    1987-01-01

    α,β-Acetylenic aldehydes and cinnamaldehyde in reaction with dimedone give the corresponding unsaturated bis(dimedonyl)methanes. In the case of acrolein and crotonaldehyde intramolecular cyclization occurs with the participation of hydroxyl of the dimedone fragment and the double bond with the formation of pyran systems. The PMR spectra were determined on Tesla BS-487C (80 MHz) and Tesla BS-467C (60 MHz) spectrometers in chloroform-d, pyridine-d 5 , and trifluoroacetic acid solutions. Internal standards HMDS and methylene chloride

  5. Synthesis of Aldehyde-Linked Nucleotides and DNA and Their Bioconjugations with Lysine and Peptides through Reductive Amination

    Czech Academy of Sciences Publication Activity Database

    Raindlová, Veronika; Pohl, Radek; Hocek, Michal

    2012-01-01

    Roč. 18, č. 13 (2012), s. 4080-4087 ISSN 0947-6539 R&D Projects: GA ČR GA203/09/0317 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotides * aldehydes * DNA * reductive amination * bioconjugations Subject RIV: CC - Organic Chemistry Impact factor: 5.831, year: 2012

  6. One Year Experience of Pheburane(®) (Sodium Phenylbutyrate) Treatment in a Patient with Argininosuccinate Lyase Deficiency.

    Science.gov (United States)

    Uçar, Sema Kalkan; Ozbaran, Burcu; Altinok, Yasemin Atik; Kose, Melis; Canda, Ebru; Kagnici, Mehtap; Coker, Mahmut

    2015-01-01

    Argininosuccinate lyase deficiency (ASLD) is a urea cycle disorder (UCD) treated with dietary adjustment and nitrogen scavenging agents. "Pheburane(®)" is a new tasteless and odour-free formulation of sodium phenylbutyrate, indicated in the treatment of UCD.A male patient diagnosed with ASLD was put on treatment with the new formulation of sodium phenylbutyrate (granules) for a period of one year, at 500 mg/kg orally in 3 intakes/day. Plasma glutamine, arginine, citrulline, argininosuccinate, serum sodium, potassium, liver function tests and urine orotate all remained unchanged over this period. There was no difference in mean ammonia levels before and after treatment, and no hyperammonemia episode occurred during treatment with Pheburane(®). An improvement in a measurement of quality of life (QOL) was noted after treatment with Pheburane(®). Good metabolic control and improved QOL were achieved throughout the treatment period.

  7. Rhodium(III)-catalyzed three-component reaction of imines, alkynes, and aldehydes through C-H activation.

    Science.gov (United States)

    Huang, Ji-Rong; Song, Qiang; Zhu, Yu-Qin; Qin, Liu; Qian, Zhi-Yong; Dong, Lin

    2014-12-15

    An efficient rhodium(III)-catalyzed tandem three-component reaction of imines, alkynes and aldehydes through CH activation has been developed. High stereo- and regioselectivity, as well as good yields were obtained in most cases. The simple and atom-economical approach offers a broad scope of substrates, providing polycyclic skeletons with potential biological properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Interaction of α,β-unsaturated aldehydes with dienes in the presence of boron trifluoride etherate

    International Nuclear Information System (INIS)

    Gramenitskaya, V.N.; Golovkina, L.S.; Orach, V.S.

    1975-01-01

    The products of the acrolein reaction with divinyl, isoprene and chloroprene catalized by BF 3 xEt 2 O are corresponding 3-cyclohexenaldehydes trimerized under the catalyst influence. Mixtures of substituted 3-cyclohexealdehydes and Δ 3 -dihydropirines were produced as results of the reaction of croton aldehyde with 1,1,3-trimethilbutadiene at high temperature as well as at 20 deg C in presence of catalyst

  9. Synergistic Effect of Endogenous and Exogenous Aldehydes on Doxorubicin Toxicity in Yeast

    Directory of Open Access Journals (Sweden)

    Jana S. Miles

    2018-01-01

    Full Text Available Anthracyclines are frequently used to treat many cancers including triple negative breast cancer, which is commonly observed in African-American women (AA, and tend to be more aggressive, carry worse prognoses, and are harder to manage because they lack molecular targets. Although effective, anthracyclines use can be limited by serious side effects and eventually the development of drug resistance. In S. cerevisiae, mutants of HOM6 display hypersensitivity to doxorubicin. HOM6 is required for synthesis of threonine and interruption of the pathway leads to accumulation of the threonine intermediate L-aspartate-semialdehyde. This intermediate may synergize with doxorubicin to kill the cell. In fact, deleting HOM3 in the first step, preventing the pathway to reach the HOM6 step, rescues the sensitivity of the hom6 strain to doxorubicin. Using several S. cerevisiae strains (wild type, hom6, hom3, hom3hom6, ydj1, siz1, and msh2, we determined their sensitivity to aldehydes and to their combination with doxorubicin, cisplatin, and etoposide. Combination of formaldehyde and doxorubicin was most effective at reducing cell survival by 31-fold–39-fold (in wild type cells relative to doxorubicin and formaldehyde alone. This effect was dose dependent on doxorubicin. Cotreatment with formaldehyde and doxorubicin also showed increased toxicity in anthracycline-resistant strains siz1 and msh2. The hom6 mutant also showed sensitivity to menadione with a 2.5-fold reduction in cell survival. The potential use of a combination of aldehydes and cytotoxic drugs could potentially lead to applications intended to enhance anthracycline-based therapy.

  10. Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils.

    Science.gov (United States)

    Duerr, Mark A; Aurora, Rajeev; Ford, David A

    2015-05-01

    α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-labeled [d4]HDA-GSH was synthesized, which further confirmed the structure, and was used to quantify natural α-ClFALD conjugates of GSH (FALD-GSH) using reverse-phase LC with detection by ESI/MS/MS using selected reaction monitoring. HDA-GSH is elevated in RAW 264.7 cells treated with physiologically relevant concentrations of exogenous 2-ClHDA. Furthermore, PMA-treated primary human neutrophils have elevated levels of HDA-GSH and the conjugate of 2-chlorooctadecanal (2-ClODA) and GSH (ODA-GSH), as well as elevated levels of 2-ClHDA and 2-ClODA. Production of both conjugates in PMA-stimulated neutrophils was reduced by 3-aminotriazole pretreatment, which also blocks endogenous α-ClFALD production. Additionally, plasma FALD-GSH levels were elevated in the K/BxN mouse arthritis model. Taken together, these studies demonstrate novel peptidoaldehydes derived from GSH and α-ClFALD in activated human neutrophils and in vivo in K/BxN mice. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  11. Insights into the structural characteristics and substrate binding analysis of chondroitin AC lyase (PsPL8A) from Pedobacter saltans.

    Science.gov (United States)

    Rani, Aruna; Dhillon, Arun; Sharma, Kedar; Goyal, Arun

    2018-04-01

    The structure of chondroitin AC lyase (PsPL8A) of family 8 polysaccharide lyase was characterized. Modeled PsPL8A structure showed, it contains N-terminal (α/α) 6 incomplete toroidal fold and a layered β sandwich structure at C-terminal. Ramchandran plot displayed 98.5% residues in favoured and 1.2% in generously allowed region. Secondary structure of PsPL8A by CD revealed 27.31% α helices 22.7% β sheets and 49.9% random coils. Protein melting study showed, PsPL8A completely unfolds at 60°C. SAXS analysis showed, PsPL8A is fully folded in solution form. The ab initio derived dummy model of PsPL8A superposed well with its modeled structure excluding some α-helices and loop region. Structural superposition and docking analysis showed, N153, W105, H203, Y208, Y212, R266 and E349 were involved in catalysis. Mutants N153A, H203A, Y212F, R266A and E349A created by SDM revealed no residual activity. Isothermal titration calorimetry analysis of Y212F and H203A with C4S polysaccharide, showed moderate binding by Y212F (Ka=9.56±3.81×10 5 ) and no binding with H203A, showing active contribution of Y212 in substrate binding. Residues Y212 and H203 or R266 might act as general base and general acid respectively. Residues N153 and E349 are likely contributing in charge neutralization and stabilizing enolate anion intermediate during β-elimination. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Revisiting the Reaction Between Diaminomaleonitrile and Aromatic Aldehydes: a Green Chemistry Approach

    Directory of Open Access Journals (Sweden)

    Francisco León

    2006-11-01

    Full Text Available The reaction between diaminomaleonitrile (DAMN and aldehydes and the resulting monoimines are well known. Since the standard reaction conditions involve the use of toxic solvents (typically methanol, we have sought to apply green chemistry principles to this reaction by either using water as the solvent without any catalysts or employing “solvent-free” conditions. The monoimines derived from DAMN are of interest as precursors for obtaining different heterocyclic systems and linear polymers. The methodologies used have significant advantages with regards to cost and environmental considerations.

  13. Single-dose, subcutaneous recombinant phenylalanine ammonia lyase conjugated with polyethylene glycol in adult patients with phenylketonuria: an open-label, multicentre, phase 1 dose-escalation trial.

    Science.gov (United States)

    Longo, Nicola; Harding, Cary O; Burton, Barbara K; Grange, Dorothy K; Vockley, Jerry; Wasserstein, Melissa; Rice, Gregory M; Dorenbaum, Alejandro; Neuenburg, Jutta K; Musson, Donald G; Gu, Zhonghua; Sile, Saba

    2014-07-05

    Phenylketonuria is an inherited disease caused by impaired activity of phenylalanine hydroxylase, the enzyme that converts phenylalanine to tyrosine, leading to accumulation of phenylalanine and subsequent neurocognitive dysfunction. Phenylalanine ammonia lyase is a prokaryotic enzyme that converts phenylalanine to ammonia and trans-cinnamic acid. We aimed to assess the safety, tolerability, pharmacokinetic characteristics, and efficacy of recombinant Anabaena variabilis phenylalanine ammonia lyase (produced in Escherichia coli) conjugated with polyethylene glycol (rAvPAL-PEG) in reducing phenylalanine concentrations in adult patients with phenylketonuria. In this open-label, phase 1, multicentre trial, single subcutaneous injections of rAvPAL-PEG were given in escalating doses (0·001, 0·003, 0·010, 0·030, and 0·100 mg/kg) to adults with phenylketonuria. Participants aged 18 years or older with blood phenylalanine concentrations of 600 μmol/L or higher were recruited from among patients attending metabolic disease clinics in the USA. The primary endpoints were safety and tolerability of rAvPAL-PEG. Secondary endpoints were the pharmacokinetic characteristics of the drug and its effect on concentrations of phenylalanine. Participants and investigators were not masked to assigned dose group. This study is registered with ClinicalTrials.gov, number NCT00925054. 25 participants were recruited from seven centres between May 6, 2008, and April 15, 2009, with five participants assigned to each escalating dose group. All participants were included in the safety population. The most frequently reported adverse events were injection-site reactions and dizziness, which were self-limited and without sequelae. Two participants had serious adverse reactions to intramuscular medroxyprogesterone acetate, a drug that contains polyethylene glycol as an excipient. Three of five participants given the highest dose of rAvPAL-PEG (0·100 mg/kg) developed a generalised skin rash

  14. Synthesis of specifically labelled L-phenylalanines using phenylalanine ammonia lyase activity

    Energy Technology Data Exchange (ETDEWEB)

    Haedener, A.; Tamm, Ch.

    1987-11-01

    Specifically labelled L-phenylalanines have been prepared using a variety of classical synthetic methods in combination with phenylalanine ammonia lyase (PAL) enzyme activity of the yeast Rhodosporidium toruloides ATCC 10788 or Rhodotorula glutinis IFO 0559, respectively. Thus, L-(2-/sup 2/H)phenyl-(2-/sup 2/H)alanine was formed from (E) -(2,2'-/sup 2/H/sub 2/)cinnamic acid and ammonia in 46% yield, whereas L-phenyl-(2-/sup 13/C, /sup 15/N)alanine was obtained from (E)-(2-/sup 13/C)cinnamic acid in 45% overall yield. Generally, labelled cinnamic acids were recovered in pure form from the reaction mixture, with a loss of 6-8%. Likewise, unchanged /sup 15/NH/sub 3/ was reisolated as /sup 15/NH/sub 4/Cl after steam distillation with overall losses of less than 4%. Labelled cinnamic acids were prepared by Knoevenagel condensations between appropriately labelled benzaldehydes and malonic acids. (2-/sup 2/H)Benzaldehyde was obtained from 2-bromotoluene by decomposition of the corresponding Grignard reagent with /sup 2/H/sub 2/O and subsequent oxidation. Since simple molecules, most of them commercially available in labelled form or otherwise easily accessible, may serve as starting material, and due to its defined stereochemistry, the reaction catalysed by PAL opens a short and attractive route to specifically labelled L-phenylalanines.

  15. Probing Reversible Chemistry in Coenzyme B12-Dependent Ethanolamine Ammonia Lyase with Kinetic Isotope Effects

    Science.gov (United States)

    Jones, Alex R; Rentergent, Julius; Scrutton, Nigel S; Hay, Sam

    2015-01-01

    Coenzyme B12-dependent enzymes such as ethanolamine ammonia lyase have remarkable catalytic power and some unique properties that enable detailed analysis of the reaction chemistry and associated dynamics. By selectively deuterating the substrate (ethanolamine) and/or the β-carbon of the 5′-deoxyadenosyl moiety of the intrinsic coenzyme B12, it was possible to experimentally probe both the forward and reverse hydrogen atom transfers between the 5′-deoxyadenosyl radical and substrate during single-turnover stopped-flow measurements. These data are interpreted within the context of a kinetic model where the 5′-deoxyadenosyl radical intermediate may be quasi-stable and rearrangement of the substrate radical is essentially irreversible. Global fitting of these data allows estimation of the intrinsic rate constants associated with CoC homolysis and initial H-abstraction steps. In contrast to previous stopped-flow studies, the apparent kinetic isotope effects are found to be relatively small. PMID:25950663

  16. Stabilization of Phenylalanine Ammonia Lyase from Rhodotorula glutinis by Encapsulation in Polyethyleneimine-Mediated Biomimetic Silica.

    Science.gov (United States)

    Cui, Jiandong; Liang, Longhao; Han, Cong; Lin Liu, Rong

    2015-06-01

    Phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis was encapsulated within polyethyleneimine-mediated biomimetic silica. The main factors in the preparation of biomimetic silica were optimized by response surface methodology (RSM). Compared to free PAL (about 2 U), the encapsulated PAL retained more than 43 % of their initial activity after 1 h of incubation time at 60 °C, whereas free PAL lost most of activity in the same conditions. It was clearly indicated that the thermal stability of PAL was improved by encapsulation. Moreover, the encapsulated PAL exhibited the excellent stability of the enzyme against denaturants and storage stability, and pH stability was improved by encapsulation. Operational stability of 7 reaction cycles showed that the encapsulated PAL was stable. Nevertheless, the K m value of encapsulated PAL in biomimetic silica was higher than that of the free PAL due to lower total surface area and increased mass transfer resistance.

  17. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae

    Science.gov (United States)

    Aldehyde reductase gene ARI1 is a recently characterized member of intermediate subfamily under SDR (short-chain dehydrogenase/reductase) superfamily that revealed mechanisms of in situ detoxification of furfural and HMF for tolerance of Saccharomyces cerevisiae. Uncharacterized open reading frames ...

  18. A note on the Noyori model for chiral amplification in the aminoalcohol-catalyzed reaction of aldehydes with dialkylzinc

    Directory of Open Access Journals (Sweden)

    IVAN GUTMAN

    1999-11-01

    Full Text Available The Noyori model of chiral amplification in the alkylation of aldehydes by means of dialkylzinc, catalyzed by chiral aminoalcohols, is further elaborated. A direct, but approximate, relation is obtained between the enantiomeric excess of the catalyst added and the enantiomeric excess of the product.

  19. NADP-Dependent Aldehyde Dehydrogenase from Archaeon Pyrobaculum sp.1860: Structural and Functional Features

    Directory of Open Access Journals (Sweden)

    Ekaterina Yu. Bezsudnova

    2016-01-01

    Full Text Available We present the functional and structural characterization of the first archaeal thermostable NADP-dependent aldehyde dehydrogenase AlDHPyr1147. In vitro, AlDHPyr1147 catalyzes the irreversible oxidation of short aliphatic aldehydes at 60–85°С, and the affinity of AlDHPyr1147 to the NADP+ at 60°С is comparable to that for mesophilic analogues at 25°С. We determined the structures of the apo form of AlDHPyr1147 (3.04 Å resolution, three binary complexes with the coenzyme (1.90, 2.06, and 2.19 Å, and the ternary complex with the coenzyme and isobutyraldehyde as a substrate (2.66 Å. The nicotinamide moiety of the coenzyme is disordered in two binary complexes, while it is ordered in the ternary complex, as well as in the binary complex obtained after additional soaking with the substrate. AlDHPyr1147 structures demonstrate the strengthening of the dimeric contact (as compared with the analogues and the concerted conformational flexibility of catalytic Cys287 and Glu253, as well as Leu254 and the nicotinamide moiety of the coenzyme. A comparison of the active sites of AlDHPyr1147 and dehydrogenases characterized earlier suggests that proton relay systems, which were previously proposed for dehydrogenases of this family, are blocked in AlDHPyr1147, and the proton release in the latter can occur through the substrate channel.

  20. Product ion distributions for the reactions of NO+ with some physiologically significant aldehydes obtained using a SRI-TOF-MS instrument

    Czech Academy of Sciences Publication Activity Database

    Mochalski, P.; Unterkofler, K.; Španěl, Patrik; Smith, D.; Amann, A.

    2014-01-01

    Roč. 363, APR 2014 (2014), s. 23-31 ISSN 1387-3806 Institutional support: RVO:61388955 Keywords : aldehydes * SRI-TOF-MS * NO+ reactions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.972, year: 2014

  1. Enantioselective ProPhenol-catalyzed addition of 1,3-diynes to aldehydes to generate synthetically versatile building blocks and diyne natural products.

    Science.gov (United States)

    Trost, Barry M; Chan, Vincent S; Yamamoto, Daisuke

    2010-04-14

    A highly enantioselective method for the catalytic addition of terminal 1,3-diynes to aldehydes was developed using our dinuclear zinc ProPhenol (1) system. Furthermore, triphenylphosphine oxide was found to interact synergistically with the catalyst to substantially enhance the chiral recognition. The generality of this catalytic transformation was demonstrated with aryl, alpha,beta-unsaturated and saturated aldehydes, of which the latter were previously limited in alkynyl zinc additions. The chiral diynol products are also versatile building blocks that can be readily elaborated; this was illustrated through highly selective trans-hydrosilylations, which enabled the synthesis of a beta-hydroxyketone and enyne. Additionally, the development of this method allowed for the rapid total syntheses of several biologically important diynol-containing natural products.

  2. S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling

    Science.gov (United States)

    Kumar, Ashok; Zamora-Pineda, Jesus; Degagné, Emilie

    2017-01-01

    Sphingosine-1-phosphate (S1P) is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL). SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC). Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes. PMID:29333002

  3. PECTATE LYASE-LIKE 9 from Brassica campestris is associated with intine formation.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Liang, Ying; Jiang, Jianxia; Ye, Nenghui; Miao, Ying; Cao, Jiashu

    2014-12-01

    Brassica campestris pectate lyase-like 9 (BcPLL9) was previously identified as a differentially expressed gene both in buds during late pollen developmental stage and in pistils during fertilization in Chinese cabbage. To characterize the gene's function, antisense-RNA lines of BcPLL9 (bcpll9) were constructed in Chinese cabbage. Self- and cross-fertilization experiments harvested half seed yields when bcpll9 lines were used as pollen donors. In vivo and in vitro pollen germination assays showed that nearly half of the pollen tubes in bcpll9 were irregular with shorter length and uneven surface. Aniline blue staining identified abnormal accumulation of a specific bright blue unknown material in the bcpll9 pollen portion. Scanning electron microscopy observation verified the abnormal outthrust material to be near the pollen germinal furrows. Transmission electron microscopy observation revealed the internal endintine layer was overdeveloped and predominantly occupied the intine. This abnormally formed intine likely induced the wavy structure and growth arrest of the pollen tube in half of the bcpll9 pollen grains, which resulted in less seed yields. Collectively, this study presented a novel PLL gene that has an important function in B. campestris intine formation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2017-01-01

    Full Text Available Sphingosine-1-phosphate (S1P is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL. SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC. Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes.

  5. Functional screening of aldehyde decarbonylases for long-chain alkane production by Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kang, Min-Kyoung; Zhou, Yongjin J.; Buijs, Nicolaas A.

    2017-01-01

    Background: Low catalytic activities of pathway enzymes are often a limitation when using microbial based chemical production. Recent studies indicated that the enzyme activity of aldehyde decarbonylase (AD) is a critical bottleneck for alkane biosynthesis in Saccharomyces cerevisiae. We therefore...... detected in other AD expressed yeast strains. Dynamic expression of SeADO and CwADO under GAL promoters increased alkane production to 0.20 mg/L/OD600 and no fatty alcohols, with even number chain lengths from C8 to C14, were detected in the cells. Conclusions: We demonstrated in vivo enzyme activities...

  6. Human liver aldehyde dehydrogenase: coenzyme binding

    International Nuclear Information System (INIS)

    Kosley, L.L.; Pietruszko, R.

    1987-01-01

    The binding of [U- 14 C] NAD to mitochondrial (E2) and cytoplasmin(E1) aldehyde dehydrogenase was measured by gel filtration and sedimentation techniques. The binding data for NAD and (E1) yielded linear Scatchard plots giving a dissociation constant of 25 (+/- 8) uM and the stoichiometry of 2 mol of NAD bound per mol of E1. The binding data for NAD and (E2) gave nonlinear Scatchard plots. The binding of NADH to E2 was measured via fluorescence enhancement; this could not be done with E1 because there was no signal. The dissociation constant for E2 by this technique was 0.7 (+/- 0.4) uM and stoichiometry of 1.0 was obtained. The binding of [U- 14 C] NADH to (E1) and (E2) was also measured by the sedimentation technique. The binding data for (E1) and NADH gave linear Scatchard plots giving a dissociation constant of 13 (+/- 6) uM and the stoichiometry of 2.0. The binding data for NADH to (E2) gave nonlinear Scatchard plots. With (E1), the dissociation constants for both NAD and NADH are similar to those determined kinetically, but the stoichiometry is only half of that found by stopped flow technique. With (E2) the dissociation constant by fluorometric procedure was 2 orders of magnitude less than that from catalytic reaction

  7. Molecular cloning and sequence analysis of a phenylalanine ammonia-lyase gene from dendrobium.

    Directory of Open Access Journals (Sweden)

    Qing Jin

    Full Text Available In this study, a phenylalanine ammonia-lyase (PAL gene was cloned from Dendrobium candidum using homology cloning and RACE. The full-length sequence and catalytic active sites that appear in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum are also found: PAL cDNA of D. candidum (designated Dc-PAL1, GenBank No. JQ765748 has 2,458 bps and contains a complete open reading frame (ORF of 2,142 bps, which encodes 713 amino acid residues. The amino acid sequence of DcPAL1 has more than 80% sequence identity with the PAL genes of other plants, as indicated by multiple alignments. The dominant sites and catalytic active sites, which are similar to that showing in PAL proteins of Arabidopsis thaliana and Nicotiana tabacum, are also found in DcPAL1. Phylogenetic tree analysis revealed that DcPAL is more closely related to PALs from orchidaceae plants than to those of other plants. The differential expression patterns of PAL in protocorm-like body, leaf, stem, and root, suggest that the PAL gene performs multiple physiological functions in Dendrobium candidum.

  8. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo{sub 2}C) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ke [Catalysis Center for Energy Innovation, Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 (United States); Yu, Weiting [Chemical Engineering, Columbia University, New York, NY 10027 (United States); Chen, Jingguang G., E-mail: jgchen@columbia.edu [Chemical Engineering, Columbia University, New York, NY 10027 (United States)

    2014-12-30

    Highlights: • Mo{sub 2}C surface can deoxygenate propanal and 1-propanol to produce propene through a similar intermediate (propoxide or η{sup 2}(C,O)-propanal). • Mo{sub 2}C surface can deoxygenate furfural and furfuryl alcohol to make 2-methylfuran through a 2-methylfuran-like intermediate. • The presence of furan ring modifies the selectivity between deoxygenation and hydrogenation/dehydrogenation pathways. - Abstract: The selective deoxygenation of aldehydes and alcohols without cleaving the C-C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo{sub 2}C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η{sup 2}(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo{sub 2}C, as well as the effect of the furan ring on the selective deoxygenation of the C=O and C-OH bonds.

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

    Science.gov (United States)

    Nuzzi, Andrea; Massi, Alessandro; Dondoni, Alessandro

    2008-10-16

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

  10. A Simple Primary Amine Catalyst for Enantioselective α-Hydroxylations and α-Fluorinations of Branched Aldehydes

    OpenAIRE

    Witten, Michael R.; Jacobsen, Eric N.

    2015-01-01

    A new primary amine catalyst for the asymmetric α-hydroxylation and α-fluorination of α-branched aldehydes is described. The products of the title transformations are generated in excellent yields and with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in the results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mec...

  11. Catalytic-site mapping of pyruvate formate lyase. Hypophosphite reaction on the acetyl-enzyme intermediate affords carbon-phosphorus bond synthesis (1-hydroxyethylphosphonate).

    Science.gov (United States)

    Plaga, W; Frank, R; Knappe, J

    1988-12-15

    Pyruvate formate-lyase of Escherichia coli cells, a homodimeric protein of 2 x 85 kDa, is distinguished by the property of containing a stable organic free radical (g = 2.0037) in its resting state. The enzyme (E-SH) achieves pyruvate conversion to acetyl-CoA via two distinct half-reactions (E-SH + pyruvate in equilibrium E-S-acetyl + formate; E-S-acetyl + CoA in equilibrium E-SH + acetyl-CoA), the first of which has been proposed to involve reversible homolytic carbon-carbon bond cleavage [J. Knappe et al. (1984) Proc. Natl Acad. Sci. USA 81, 1332-1335]. Present studies identified Cys-419 as the covalent-catalytic cysteinyl residue via CNBr fragmentation of E-S-[14C]acetyl and radio-sequencing of the isolated peptide CB-Ac (amino acid residues 406-423). Reaction of the formate analogue hypophosphite with E-S-acetyl was investigated and found to produce 1-hydroxyethylphosphonate with a thioester linkage to the adjacent Cys-418. The structure was determined from the chymotryptic peptide CH-P (amino acid residues 415-425), using 31P-NMR spectroscopy (delta = 44 ppm) and by chemical characterisation through degradation into 1-hydroxyethylphosphonate with phosphodiesterase or bromine. This novel P-C-bond synthesis involves the enzyme-based free radical and is proposed to resemble the physiological C-C-bond synthesis (pyruvate production) from formate and E-S-acetyl. These findings are interpreted as proof of a radical mechanism for the action of pyruvate formate-lyase. The central Cys-418/Cys-419 pair of the active site shows a distinctive thiolate property even in the inactive (nonradical) form of the enzyme, as determined using an iodoacetate probe.

  12. Mechanistic deductions from kinetic isotope effects and pH studies of pyridoxal phosphate dependent carbon-carbon lyases: Erwinia herbicola and Citrobacter freundii tyrosine phenol-lyase

    International Nuclear Information System (INIS)

    Kiick, D.M.; Phillips, R.S.

    1988-01-01

    The pH dependence of the kinetic parameters and primary deuterium isotope effects have been determined for tyrosine phenol-lyase from both Erwinia herbicola and Citrobacter freundii. The primary deuterium isotope effects indicate that proton abstraction from the 2-position of the substrate is partially rate-limiting for both enzymes. The C. freundii enzyme primary deuterium isotope effects [DV = 3.5 and D(V/Ktyr) = 2.5] are pH independent, indicating that tyrosine is not sticky (i.e., does not dissociate slower than it reacts to give products). Since Vmax for both tyrosine and the alternate substrate S-methyl-L-cysteine is also pH independent, substrate binds only to the correctly protonated form of the enzyme. For the E. herbicola enzyme, both Vmax and V/K for tyrosine or S-methyl-L-cysteine are pH dependent, as well as both DV and D(V/Ktyr). Thus, while both the protonated and unprotonated enzyme can bind substrate, and may be interconverted directly, only the unprotonated Michaelis complex is catalytically competent. At pH 9.5, DV = 2.5 and D(V/Ktyr) = 1.5. However, at pH 6.4 the isotope effect on both parameters is equal to 4.1. From these data, the forward commitment factor (cf = 5.2) and catalytic ratio (cvf = 1.1) for tyrosine and S-methyl-L-cysteine (cf = 2.2, cvf = 24) are calculated. Also, the Michaelis complex partition ratio (cf/cvf) for substrate and products is calculated to be 4.7 for tyrosine and 0.1 for S-methyl-L-cysteine

  13. Cu-catalyzed C(sp³)-H bond activation reaction for direct preparation of cycloallyl esters from cycloalkanes and aromatic aldehydes.

    Science.gov (United States)

    Zhao, Jincan; Fang, Hong; Han, Jianlin; Pan, Yi

    2014-05-02

    Cu-catalyzed dehydrogenation-olefination and esterification of C(sp(3))-H bonds of cycloalkanes with TBHP as an oxidant has been developed. The reaction involves four C-H bond activations and gives cycloallyl ester products directly from cycloalkanes and aromatic aldehydes.

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

    Science.gov (United States)

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

    2007-10-29

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

  15. Transcriptional regulation of Saccharomyces cerevisiaeCYS3 encoding cystathionine γ-lyase

    Science.gov (United States)

    Hiraishi, Hiroyuki; Miyake, Tsuyoshi

    2008-01-01

    In studying the regulation of GSH11, the structural gene of the high-affinity glutathione transporter (GSH-P1) in Saccharomyces cerevisiae, a cis-acting cysteine responsive element, CCGCCACAC (CCG motif), was detected. Like GSH-P1, the cystathionine γ-lyase encoded by CYS3 is induced by sulfur starvation and repressed by addition of cysteine to the growth medium. We detected a CCG motif (−311 to −303) and a CGC motif (CGCCACAC; −193 to −186), which is one base shorter than the CCG motif, in the 5′-upstream region of CYS3. One copy of the centromere determining element 1, CDE1 (TCACGTGA; −217 to −210), being responsible for regulation of the sulfate assimilation pathway genes, was also detected. We tested the roles of these three elements in the regulation of CYS3. Using a lacZ-reporter assay system, we found that the CCG/CGC motif is required for activation of CYS3, as well as for its repression by cysteine. In contrast, the CDE1 motif was responsible for only activation of CYS3. We also found that two transcription factors, Met4 and VDE, are responsible for activation of CYS3 through the CCG/CGC and CDE1 motifs. These observations suggest a dual regulation of CYS3 by factors that interact with the CDE1 motif and the CCG/CGC motifs. PMID:18317767

  16. Modification of Cys-418 of pyruvate formate-lyase by methacrylic acid, based on its radical mechanism.

    Science.gov (United States)

    Plaga, W; Vielhaber, G; Wallach, J; Knappe, J

    2000-01-21

    The recently determined crystal structure of pyruvate formate-lyase (PFL) suggested a new view of the mechanism of this glycyl radical enzyme, namely that intermediary thiyl radicals of Cys-418 and Cys-419 participate in different ways [Becker, A. et al. (1999) Nat. Struct. Biol. 6, 969-975]. We report here a suicide reaction of PFL that occurs with the substrate-analog methacrylate with retention of the protein radical (K(I)=0.42 mM, k(i)=0.14 min(-1)). Using [1-(14)C]methacrylate (synthesized via acetone cyanhydrin), the reaction end-product was identified by peptide mapping and cocrystallization experiments as S-(2-carboxy-(2S)-propyl) substituted Cys-418. The stereoselectivity of the observed Michael addition reaction is compatible with a radical mechanism that involves Cys-418 thiyl as nucleophile and Cys-419 as H-atom donor, thus supporting the functional assignments of these catalytic amino acid residues derived from the protein structure.

  17. Generation of 2-Furfurylthiol by Carbon-Sulfur Lyase from the Baijiu Yeast Saccharomyces cerevisiae G20.

    Science.gov (United States)

    Zha, Musu; Sun, Baoguo; Yin, Sheng; Mehmood, Arshad; Cheng, Lei; Wang, Chengtao

    2018-03-07

    2-Furfurylthiol is the representative aroma compound of Chinese sesame-flavored baijiu. Previous studies demonstrated that baijiu yeasts could generate 2-furfurylthiol using furfural and l-cysteine as precursors and that the Saccharomyces cerevisiae genes STR3 and CYS3 are closely related to 2-furfurylthiol biosynthesis. To confirm the mechanism of the STR3- and CYS3-gene products on 2-furfurylthiol biosynthesis, their encoded proteins were purified, and we confirmed their activities as carbon-sulfur lyases. Str3p and Cys3p were able to cleave the cysteine-furfural conjugate to release 2-furfurylthiol. Moreover, the characterization of the enzymatic properties of the purified proteins shows good thermal stabilities and wide pH tolerances, which enable their strong potential for various applications. These data provide direct evidence that yeast Str3p and Cys3p release 2-furfurylthiol in vitro, which can be applied to improve baijiu flavor.

  18. Enantioselective Addition of Allyltin Reagents to Amino Aldehydes Catalyzed with Bis(oxazolinylphenylrhodium(III Aqua Complexes

    Directory of Open Access Journals (Sweden)

    Hisao Nishiyama

    2011-06-01

    Full Text Available Bis(oxazolinylphenylrhodium(III aqua complexes, (PheboxRhX2(H2O [X = Cl, Br], were found to be efficient Lewis acid catalysts for the enantioselective addition of allyl- and methallyltributyltin reagents to amino aldehydes. The reactions proceed smoothly in the presence of 5–10 mol % of (PheboxRhX2(H2O complex at ambient temperature to give the corresponding amino alcohols with modest to good enantioselectivity (up to 94% ee.

  19. N-Heterocyclic Carbene-Catalyzed Olefination of Aldehydes with Vinyliodonium Salts To Generate α,β-Unsaturated Ketones.

    Science.gov (United States)

    Rajkiewicz, Adam A; Kalek, Marcin

    2018-04-06

    An organocatalyzed metal-free, direct olefination of aldehydes with vinyliodonium salts has been achieved by an N-heterocyclic carbene-promoted C-H bond activation. The reaction proceeds under very mild conditions, delivering a range of (hetero)aryl-vinyl ketones in good yields. The retention of the double bond configuration is uniformly observed, and the application of 2-methoxyphenyl auxiliary group in iodonium salts secures a complete selectivity of the vinyl transfer.

  20. Mechanism of the Dual Activities of Human CYP17A1 and Binding to Anti-Prostate Cancer Drug Abiraterone Revealed by a Novel V366M Mutation Causing 17,20 Lyase Deficiency

    Directory of Open Access Journals (Sweden)

    Mónica Fernández-Cancio

    2018-04-01

    Full Text Available The CYP17A1 gene regulates sex steroid biosynthesis in humans through 17α-hydroxylase/17,20 lyase activities and is a target of anti-prostate cancer drug abiraterone. In a 46, XY patient with female external genitalia, together with a loss of function mutation S441P, we identified a novel missense mutation V366M at the catalytic center of CYP17A1 which preferentially impaired 17,20 lyase activity. Kinetic experiments with bacterially expressed proteins revealed that V366M mutant enzyme can bind and metabolize pregnenolone to 17OH-pregnenolone, but 17OH-pregnenolone binding and conversion to dehydroepiandrosterone (DHEA was impaired, explaining the patient’s steroid profile. Abiraterone could not bind and inhibit the 17α-hydroxylase activity of the CYP17A1-V366M mutant. Molecular dynamics (MD simulations showed that V366M creates a “one-way valve” and suggests a mechanism for dual activities of human CYP17A1 where, after the conversion of pregnenolone to 17OH-pregnenolone, the product exits the active site and re-enters for conversion to dehydroepiandrosterone. The V366M mutant also explained the effectiveness of the anti-prostate cancer drug abiraterone as a potent inhibitor of CYP17A1 by binding tightly at the active site in the WT enzyme. The V366M is the first human mutation to be described at the active site of CYP17A1 that causes isolated 17,20 lyase deficiency. Knowledge about the specificity of CYP17A1 activities is of importance for the development of treatments for polycystic ovary syndrome and inhibitors for prostate cancer therapy.

  1. Crystal structure and mechanism of the Staphylococcus cohnii virginiamycin B lyase (Vgb).

    Science.gov (United States)

    Lipka, Magdalena; Filipek, Renata; Bochtler, Matthias

    2008-04-08

    The semisynthetic streptogramin antibiotic quinupristin/dalfopristin (trade name Synercid, Aventis Pharma) is a mixture of the A-type streptogramin dalfopristin and the B-type streptogramin quinupristin, a capped hexapeptide macrolactone. Quinupristin/dalfopristin was developed to combat multidrug resistant pathogens, but suffers from its own problems with drug resistance. Virginiamycin B lyase (Vgb) inactivates the quinupristin component of Synercid by lactone ring opening. Remarkably, the enzyme promotes this reaction by intramolecular beta-elimination without the involvement of a water molecule. Recently, structures of S. aureus Vgb in the presence and absence of substrate were reported and used together with detailed mutagenesis data to suggest a catalytic mechanism. Here, we report an independent determination of the S. cohnii Vgb crystal structure and a biochemical characterization of the enzyme. As expected, the S. cohnii and S. aureus Vgb structures and active sites are very similar. Moreover, both enzymes catalyze quinupristin lactone ring opening with similar rate constants, albeit perhaps with different dependencies on divalent metal ions. Replacement of the conserved active site residues His228, Glu268, or His270 with alanine reduces or abolishes S. cohnii Vgb activity. Residue Lys285 in S. cohnii Vgb is spatially equivalent to the S. aureus Vgb active site residue Glu284. A glutamate but not an alanine residue can substitute for the lysine without significant loss of activity.

  2. Control of phenylalanine ammonia-lyase gene promoters from pea by UV radiation

    International Nuclear Information System (INIS)

    Pluskota, W.E.; Michalczyk, D.J.; Gorecki, R.J.

    2005-01-01

    The gene fusion system was used to study UV light-control of PS PAL1 and PS PAL2 genes encoding phenylalanine ammonia-lyase of pea. The induction of pea PAL promoters was analysed in transgenic tobacco plants. Binary plasmids (derivatives of pBI101.2 vector) containing 5' regulatory fragments of PS PAL1 and PS PAL2 linked to reporter genes (GUS, LUC) were constructed. The analyses were performed with the use of single constructs (containing one variant of PS PAL promoter and one reporter gene) and dual constructs (containing both PS PAL1 and PS PAL2 promoters connected with different reporter genes). The use of dual constructs enabled the evaluation of both PS PAL promoters activity in the same plant. The analyses of in vitro grown plants have shown that both PAL promoters are strongly induced in leaves subjected to UV radiation. In some cases, the UV-stimulated expression exceeded the exposed areas. This phenomenon was observed more often in the leaves of plants containing the PS PAL1::GUS than PS PAL2::GUS construct. Removal of boxes 2, 4, 5 from PS PAL1 promoter and deletion of its 5' end region (-339 to -1394) decreases the level of gene expression but does not eliminate its responsiveness to UV

  3. 1H NMR studies of substrate hydrogen exchange reactions catalyzed by L-methionine gamma-lyase

    International Nuclear Information System (INIS)

    Esaki, N.; Nakayama, T.; Sawada, S.; Tanaka, H.; Soda, K.

    1985-01-01

    Hydrogen exchange reactions of various L-amino acids catalyzed by L-methionine gamma-lyase (EC 4.4.1.11) have been studied. The enzyme catalyzes the rapid exchange of the alpha- and beta-hydrogens of L-methionine and S-methyl-L-cysteine with deuterium from the solvent. The rate of alpha-hydrogen exchange was about 40 times faster than that of the enzymatic elimination reaction of the sulfur-containing amino acids. The enzyme also catalyzes the exchange reaction of alpha- and beta-hydrogens of the straight-chain L-amino acids which are not susceptible to elimination. The exchange rates of the alpha-hydrogen and the total beta-hydrogens of L-alanine and L-alpha-aminobutyrate with deuterium followed first-order kinetics. For L-norvaline, L-norleucine, S-methyl-L-cysteine, and L-methionine, the rate of alpha-hydrogen exchange followed first-order kinetics, but the rate of total beta-hydrogen exchange decreased due to a primary isotope effect at the alpha-position. L-Phenylalanine and L-tryptophan slowly underwent alpha-hydrogen exchange. The pro-R hydrogen of glycine was deuterated stereospecifically

  4. The use of aldehyde indicators to determine glutaraldehyde and alkaline glutaraldehyde contamination in chemical protective gloves.

    Science.gov (United States)

    Vo, Evanly; Zhuang, Zhenzhen

    2009-07-01

    The aim of this study was to assess the use of aldehyde indicator pads for detection of glutaraldehyde and alkaline glutaraldehyde permeation through chemical protective gloves under simulated in-use conditions. The quantitative analysis of glutaraldehyde permeation through a glove material was determined for Metricide, Wavicide, and 50% glutaraldehyde following a solvent-desorption process and gas chromatographic analysis. All glutaraldehyde solutions exhibited >99% adsorption (including both the glutaraldehyde oligomers of the reaction product and the excess glutaraldehyde) on the pads over the spiking range 0.05-5.0 microL. Breakthrough times for protective gloves were determined using the Thermo-Hand test method, and found to range from 76 to 150, from 170 to 230, and from 232 to 300 min for Metricide, Wavicide, and 50% glutaraldehyde, respectively. Glutaraldehyde recovery was calculated and ranged from 61 to 80% for all glutaraldehyde solutions. The mass of glutaraldehyde in these solutions at the time of breakthrough detection ranged from 17 to 18, from 18 to 19, and from 19 to 20 microg/cm(2) for Wavicide, 50% glutaraldehyde solution, and Metricide, respectively. Aldehyde indicator pads and the Thermo-Hand test method together should find utility in detecting, collecting, and quantitatively analyzing glutaraldehyde permeation samples through chemical protective gloves under simulated in-use conditions.

  5. Species Specificity of Aldehyde and Fatty Acid Profiles of Four Family Group Representatives within the Insect Infraorder Pentatomomorpha (Hemiptera: Heteroptera)

    Czech Academy of Sciences Publication Activity Database

    Tomčala, Aleš; Jirošová, Anna; Žáček, Petr; Kaušková, Markéta; Hovorka, Oldřich; Koutek, Bohumír

    2017-01-01

    Roč. 14, č. 5 (2017), č. článku e1600420. ISSN 1612-1872 Institutional support: RVO:61388963 Keywords : defensive compounds * fat body * Pentatomomorpha * triacylglycerol * unsaturated aldehydes Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.440, year: 2016

  6. Species Specificity of Aldehyde and Fatty Acid Profiles of Four Family Group Representatives within the Insect Infraorder Pentatomomorpha (Hemiptera: Heteroptera)

    Czech Academy of Sciences Publication Activity Database

    Tomčala, Aleš; Jirošová, A.; Žáček, P.; Kaušková, M.; Hovorka, O.; Koutek, B.

    2017-01-01

    Roč. 14, č. 5 (2017), č. článku e1600420. ISSN 1612-1872 Institutional support: RVO:60077344 Keywords : defensive compounds * fat body * Pentatomomorpha * triacylglycerol * unsaturated aldehydes Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 1.440, year: 2016

  7. Development of a novel selective ESI-MS derivatization reagent - ssynthesis and optimization for the analysis of aldehydes in biological mixtures

    NARCIS (Netherlands)

    Eggink, M.; Wijtmans, M.; de Esch, I.J.P.; Lingeman, H.; Niessen, W.M.A.; Irth, H.

    2008-01-01

    In LC-MS, derivatization is primarily used to improve ionization characteristics, especially for analytes that are not (efficiently) ionized by ESI or APCI such as aldehydes, sugars, and steroids. Derivatization strategies are then directed at the incorporation of a group with a permanent charge. A

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

    Data.gov (United States)

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

  9. Potential Inhibitors for Isocitrate Lyase of Mycobacterium tuberculosis and Non-M. tuberculosis: A Summary

    Directory of Open Access Journals (Sweden)

    Yie-Vern Lee

    2015-01-01

    Full Text Available Isocitrate lyase (ICL is the first enzyme involved in glyoxylate cycle. Many plants and microorganisms are relying on glyoxylate cycle enzymes to survive upon downregulation of tricarboxylic acid cycle (TCA cycle, especially Mycobacterium tuberculosis (MTB. In fact, ICL is a potential drug target for MTB in dormancy. With the urge for new antitubercular drug to overcome tuberculosis treat such as multidrug resistant strain and HIV-coinfection, the pace of drug discovery has to be increased. There are many approaches to discovering potential inhibitor for MTB ICL and we hereby review the updated list of them. The potential inhibitors can be either a natural compound or synthetic compound. Moreover, these compounds are not necessary to be discovered only from MTB ICL, as it can also be discovered by a non-MTB ICL. Our review is categorized into four sections, namely, (a MTB ICL with natural compounds; (b MTB ICL with synthetic compounds; (c non-MTB ICL with natural compounds; and (d non-MTB ICL with synthetic compounds. Each of the approaches is capable of overcoming different challenges of inhibitor discovery. We hope that this paper will benefit the discovery of better inhibitor for ICL.

  10. Rationalization of an unusual solvent-induced inversion of enantiomeric excess in organocatalytic selenylation of aldehydes.

    Science.gov (United States)

    Burés, Jordi; Dingwall, Paul; Armstrong, Alan; Blackmond, Donna G

    2014-08-11

    An unusual solvent-induced inversion of the sense of enantioselectivity observed in the α-selenylation of aldehydes catalyzed by a diphenylprolinol silyl ether catalyst is correlated to the presence of intermediates formed subsequent to the highly selective C-Se bond-forming step in the catalytic cycle. This work provides support for a mechanistic concept for enamine catalysis and includes a general role for "downstream intermediates" in selectivity outcomes in organocatalysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Chemoselective Synthesis of Dithioacetals from Bio-aldehydes with Zeolites under Ambient and Solvent-free Conditions

    DEFF Research Database (Denmark)

    Li, Hu; Yang, Tingting; Riisager, Anders

    2017-01-01

    of commercial and modified zeolites are excellent catalysts for thioacetalization of different thiols with carbonyl compounds, including biomass-derived aldehydes, at room temperature under solvent-free conditions. A near quantitative yield of dithioacetal was obtained over H-beta(19) at room temperature......Dithioacetals are an important class of versatile compounds extensively applied in pharmaceuticals, separations, electrochemistry, and organic synthesis, but few heterogeneous catalytic systems are reported to be generally applicable for their synthesis from a wide range of substrates. A series...

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

    Science.gov (United States)

    Kalalian, Carmen; Roth, Estelle; Chakir, Abdelkhaleq

    2017-04-01

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

  13. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

    Directory of Open Access Journals (Sweden)

    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  14. Characterization of Aldehyde Crosslinked Kenaf Regenerated Cellulose Film

    Directory of Open Access Journals (Sweden)

    Hatika Kaco

    2015-08-01

    Full Text Available Regenerated cellulose film with better mechanical properties was successfully produced by introducing aldehyde crosslinker during the regeneration process. The cellulose source material was derived from kenaf core powder and dissolved in LiOH/urea solvent at −13 °C to form a cellulose solution. The cellulose solution was cast and coagulated in a crosslinker bath at different percentages of glutaraldehyde (GA and glyoxal (GX to form a regenerated cellulose film. According to Fourier transform infrared spectroscopy (FTIR spectra, the hydroxyl group of the cellulose was reduced, reducing the percentage of swelling as the percentage of crosslinker was increased. X-ray diffraction (XRD patterns showed that the crystallinity index of the crosslinked film was decreased. The pore size of the films decreased as the percentage of crosslinker was increased, resulting in decreased film transparency. The pore volume and percentage of swelling in water of the films also increased with decreases in the pore size as the percentage of crosslinker was increased. The tensile strengths of the GA- and GX-crosslinked films increased by 20 and 15% with the addition of 20% of each crosslinker, respectively.

  15. Genetic analysis of the pelA-pelE cluster encoding the acidic and basic pectate lyases in Erwinia chrysanthemi EC16.

    Science.gov (United States)

    Barras, F; Chatterjee, A K

    1987-10-01

    In Erwinia chrysanthemi (EC16) the clustered pelA and pelE genes encode an acidic (pI 4.2) and a basic (pI 10.0) pectate lyase (Pel), respectively. The pelA gene has been isolated on a 1.2 kb restriction fragment and the direction of transcription determined. DNA hybridization analysis showed that the pelE sequence shares DNA homology with pelA but not with pelB or pelC, two genes encoding other Pel species in EC16. Since Pel A and Pel E enzymes showed little similarity in terms of catalytic properties, it is proposed that pelA and pelE are duplicates which have highly diverged.

  16. Acetic acid-promoted condensation of o-phenylenediamine with aldehydes into 2-aryl-1-(arylmethyl-1H-benzimidazoles under microwave irradiation

    Directory of Open Access Journals (Sweden)

    DAVOOD AZARIF

    2010-09-01

    Full Text Available An efficient and simple procedure was developed for the green synthesis of various 2-aryl-1-(arylmethyl-1H-benzimidazoles in high yields by acetic acid-promoted condensation of o-phenylenediamine with aldehydes in air under microwave irradiation and transition metal catalyst-free conditions.

  17. Anti-Biofilm Activity of a Long-Chain Fatty Aldehyde from Antarctic Pseudoalteromonas haloplanktis TAC125 against Staphylococcus epidermidis Biofilm.

    Science.gov (United States)

    Casillo, Angela; Papa, Rosanna; Ricciardelli, Annarita; Sannino, Filomena; Ziaco, Marcello; Tilotta, Marco; Selan, Laura; Marino, Gennaro; Corsaro, Maria M; Tutino, Maria L; Artini, Marco; Parrilli, Ermenegilda

    2017-01-01

    Staphylococcus epidermidis is a harmless human skin colonizer responsible for ~20% of orthopedic device-related infections due to its capability to form biofilm. Nowadays there is an interest in the development of anti-biofilm molecules. Marine bacteria represent a still underexploited source of biodiversity able to synthesize a broad range of bioactive compounds, including anti-biofilm molecules. Previous results have demonstrated that the culture supernatant of Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125 impairs the formation of S. epidermidis biofilm. Further, evidence supports the hydrophobic nature of the active molecule, which has been suggested to act as a signal molecule. In this paper we describe an efficient activity-guided purification protocol which allowed us to purify this anti-biofilm molecule and structurally characterize it by NMR and mass spectrometry analyses. Our results demonstrate that the anti-biofilm molecule is pentadecanal, a long-chain fatty aldehyde, whose anti- S. epidermidis biofilm activity has been assessed using both static and dynamic biofilm assays. The specificity of its action on S. epidermidis biofilm has been demonstrated by testing chemical analogs of pentadecanal differing either in the length of the aliphatic chain or in their functional group properties. Further, indications of the mode of action of pentadecanal have been collected by studying the bioluminescence of a Vibrio harveyi reporter strain for the detection of autoinducer AI-2 like activities. The data collected suggest that pentadecanal acts as an AI-2 signal. Moreover, the aldehyde metabolic role and synthesis in the Antarctic source strain has been investigated. To the best of our knowledge, this is the first report on the identification of an anti-biofilm molecule form from cold-adapted bacteria and on the action of a long-chain fatty aldehyde acting as an anti-biofilm molecule against S. epidermidis .

  18. Effect of uridine protecting groups on the diastereoselectivity of uridine-derived aldehyde 5’-alkynylation

    Directory of Open Access Journals (Sweden)

    Raja Ben Othman

    2017-08-01

    Full Text Available The 5’-alkynylation of uridine-derived aldehydes is described. The addition of alkynyl Grignard reagents on the carbonyl group is significantly influenced by the 2’,3’-di-O-protecting groups (R1: O-alkyl groups led to modest diastereoselectivities (65:35 in favor of the 5’R-isomer, whereas O-silyl groups promoted higher diastereoselectivities (up to 99:1 in favor of the 5’S-isomer. A study related to this protecting group effect on the diastereoselectivity is reported.

  19. Formylbenzene diazonium hexafluorophosphate reagent for tyrosine-selective modification of proteins and the introduction of a bioorthogonal aldehyde

    OpenAIRE

    Gavrilyuk, Julia; Ban, Hitoshi; Nagano, Masanobu; Hakamata, Wataru; Barbas, Carlos F.

    2012-01-01

    4-Formylbenzene diazonium hexafluorophosphate (FBDP) is a novel bench-stable crystalline diazonium salt that reacts selectively with tyrosine to install a bioorthogonal aldehyde functionality. Model studies with N-acyl-tyrosine methylamide allowed us to identify conditions optimal for tyrosine ligation reactions with small peptides and proteins. FBDP-based conjugation was used for the facile introduction of small molecule tags, poly(ethylene) glycol chains (PEGylation), and functional small m...

  20. NEW COPPER(II CHELATES WITH SHIFF BASES — CONDENSATION PRODUCTS OF SALICYLIC ALDEHYDE AND AMINONAPHTHALEN DERIVATIVES

    Directory of Open Access Journals (Sweden)

    L. S. Skorokhod

    2015-03-01

    salicylic aldehyde with 1-aminonaphthalen (HL1, 1,8-diaminonaphthalen (H3L2, 1-amino-8-naphthalensulfonic acid (H2L3: [Cu(HL12(H2O2] (I, [Cu(H2L22] (II, [Cu(HL32](III — were synthesized. I—III were investigated by elementary analysis, X-ray powder diffraction, thermogravimetry, magnetic susceptibility and electric conductivity measurements, IR and diffuse reflectance spectroscopy. The way of coordination and the geometry of synthesized complexes were determinated.

  1. Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols.

    Science.gov (United States)

    Nacsa, Eric D; MacMillan, David W C

    2018-03-07

    Nature routinely engages alcohols as leaving groups, as DNA biosynthesis relies on the removal of water from ribonucleoside diphosphates by a radical-mediated "spin-center shift" (SCS) mechanism. Alcohols, however, remain underused as alkylating agents in synthetic chemistry due to their low reactivity in two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide evidence for SCS as a key elementary step, identify the origins of competing reactions, and enable improvements in chemoselectivity by rational photocatalyst design.

  2. Preliminary structural investigations of the Eut-L shell protein of the ethanolamine ammonia-lyase metabolosome of Escherichia coli

    International Nuclear Information System (INIS)

    Nikolakakis, Kiel; Ohtaki, Akashi; Newton, Keith; Chworos, Arkadiusz; Sagermann, Martin

    2009-01-01

    Preliminary X-ray analysis of crystals of the bacterial microcompartment shell protein Eut-L from Escherichia coli is reported. The ethanolamine ammonia-lyase microcompartment is composed of five different shell proteins that have been proposed to assemble into symmetrically shaped polyhedral particles of varying sizes. Here, preliminary X-ray analysis of crystals of the bacterial microcompartment shell protein Eut-L from Escherichia coli is reported. Cloning, overexpression and purification resulted in highly pure protein that crystallized readily under many different conditions. In all cases the protein forms thin hexagonal plate-shaped crystals belonging to space group P3 that are of unusually high stability against different solvent conditions. The crystals diffracted to a resolution of 2.0 Å using synchrotron radiation but proved to be radiation-sensitive. Preparations of heavy-atom-derivatized crystals for use in determining the three-dimensional structure are under way

  3. In situ generation of the Ohira-Bestmann reagent from stable sulfonyl azide: scalable synthesis of alkynes from aldehydes.

    Science.gov (United States)

    Jepsen, Tue Heesgaard; Kristensen, Jesper Langgaard

    2014-10-03

    We report an improved method for in situ generation of the Ohira-Bestmann reagent. Using the recently reported bench-stable imidazole-1-sulfonyl azide as diazotransfer reagent, this new method represents a scalable and convenient approach for the transformation of aldehydes into terminal alkynes. The method features an easier workup compared to the existing in situ protocol due to increased aqueous solubility of waste products.

  4. The expression of aldehyde dehydrogenase 1 (ALDH1) in ovarian carcinomas and its clinicopathological associations: a retrospective study

    OpenAIRE

    Huang, Ruixia; Li, Xiaoran; Holm, Ruth; Trope, Claes G; Nesland, Jahn M; Suo, Zhenhe

    2015-01-01

    Background Aldehyde dehydrogenase 1 (ALDH1) is widely used as a specific cancer stem cell marker in a variety of cancers, and may become a promising target for cancer therapy. However, the role of its expression in tumor cells and the microenvironment in different cancers is still controversial. Methods To clarify the clinicopathological effect of ALDH1 expression in ovarian carcinoma, a series of 248...

  5. Ozone-surface reactions in five homes: surface reaction probabilities, aldehyde yields, and trends.

    Science.gov (United States)

    Wang, H; Morrison, G

    2010-06-01

    Field experiments were conducted in five homes during three seasons (summer 2005, summer 2006 and winter 2007) to quantify ozone-initiated secondary aldehyde yields, surface reaction probabilities, and trends any temporal over a 1.5-year interval. Surfaces examined include living room carpets, bedroom carpets, kitchen floors, kitchen counters, and living room walls. Reaction probabilities for all surfaces for all seasons ranged from 9.4 x 10(-8) to 1.0 x 10(-4). There were no significant temporal trends in reaction probabilities for any surfaces from summer 2005 to summer 2006, nor over the entire 1.5-year period, indicating that it may take significantly longer than this period for surfaces to exhibit any 'ozone aging' or lowering of ozone-surface reactivity. However, all surfaces in three houses exhibited a significant decrease in reaction probabilities from summer 2006 to winter 2007. The total yield of aldehydes for the summer of 2005 were nearly identical to that for summer of 2006, but were significantly higher than for winter 2007. We also observed that older carpets were consistently less reactive than in newer carpets, but that countertops remained consistently reactive, probably because of occupant activities such as cooking and cleaning. Ozone reactions taking place at indoor surfaces significantly influence personal exposure to ozone and volatile reaction products. These field studies show that indoor surfaces only slowly lose their ability to react with ozone over several year time frames, and that this is probably because of a combination of large reservoirs of reactive coatings and periodic additions of reactive coatings in the form of cooking, cleaning, and skin-oil residues. When considering exposure to ozone and its reaction products and in the absence of dramatic changes in occupancy, activities or furnishings, indoor surface reactivity is expected to change very slowly.

  6. PECTATE LYASE-LIKE10 is associated with pollen wall development in Brassica campestris.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Lv, Meiling; Miao, Ying; Cao, Jiashu

    2014-11-01

    PECTATE LYASE-LIKE10 (PLL10) was previously identified as one of the differentially expressed genes both in microspores during the late pollen developmental stages and in pistils during the fertilization process in Chinese cabbage (Brassica campestris ssp. chinensis). Here, antisense-RNA was used to study the functions of BcPLL10 in Chinese cabbage. Abnormal pollen was identified in the transgenic lines (bcpll10-4, -5, and -6). In fertilization experiments, fewer seeds were harvested when the antisense-RNA lines were used as pollen donor. In vivo and in vitro pollen germination assays less germinated pollen tubes were observed in bcpll10 lines. Scanning electron microscopy observation verified that the tryphine materials were over accumulated around the pollen surface and sticked them together in bcpll10. Moreover, transmission electron microscopy observation revealed that the internal endintine was overdeveloped and predominantly occupied the intine, and disturbed the normal proportional distribution of the two layers in the non-germinal furrow region; and no obvious demarcation existed between them in the germinal furrow region in the bcpll10 pollen. Collectively, this study presented a novel PLL gene that played an important role during the pollen wall development in B. campestris, which may also possess potential importance for male sterility usage in agriculture. © 2014 Institute of Botany, Chinese Academy of Sciences.

  7. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    Directory of Open Access Journals (Sweden)

    Christina eNeumann

    2014-10-01

    Full Text Available Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6, thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  8. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    KAUST Repository

    Neumann, Christina

    2014-10-17

    Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6), thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  9. Synthesis of New Chiral Benzimidazolylidene–Rh Complexes and Their Application in Asymmetric Addition Reactions of Organoboronic Acids to Aldehydes

    Directory of Open Access Journals (Sweden)

    Weiping He

    2016-09-01

    Full Text Available A series of novel chiral N-heterocyclic carbene rhodium complexes (NHC–Rh based on benzimidazole have been prepared, and all of the NHC–Rh complexes were fully characterized by NMR and mass spectrometry. These complexes could be used as catalysts for the asymmetric 1,2-addition of organoboronic acids to aldehydes, affording chiral diarylmethanols with high yields and moderate enantioselectivities.

  10. Characterization of aldehyde dehydrogenase isozymes in ovarian cancer tissues and sphere cultures

    International Nuclear Information System (INIS)

    Saw, Yu-Ting; Thompson, David; Vasiliou, Vasilis; Berkowitz, Ross S; Ng, Shu-Wing; Yang, Junzheng; Ng, Shu-Kay; Liu, Shubai; Singh, Surendra; Singh, Margit; Welch, William R; Tsuda, Hiroshi; Fong, Wing-Ping

    2012-01-01

    Aldehyde dehydrogenases belong to a superfamily of detoxifying enzymes that protect cells from carcinogenic aldehydes. Of the superfamily, ALDH1A1 has gained most attention because current studies have shown that its expression is associated with human cancer stem cells. However, ALDH1A1 is only one of the 19 human ALDH subfamilies currently known. The purpose of the present study was to determine if the expression and activities of other major ALDH isozymes are associated with human ovarian cancer and ovarian cancer sphere cultures. Immunohistochemistry was used to delineate ALDH isozyme localization in clinical ovarian tissues. Western Blot analyses were performed on lysates prepared from cancer cell lines and ovarian cancer spheres to confirm the immunohistochemistry findings. Quantitative reverse transcription-polymerase chain reactions were used to measure the mRNA expression levels. The Aldefluor® assay was used to measure ALDH activity in cancer cells from the four tumor subtypes. Immunohistochemical staining showed significant overexpression of ALDH1A3, ALDH3A2, and ALDH7A1 isozymes in ovarian tumors relative to normal ovarian tissues. The expression and activity of ALDH1A1 is tumor type-dependent, as seen from immunohistochemisty, Western blot analysis, and the Aldefluor® assay. The expression was elevated in the mucinous and endometrioid ovarian epithelial tumors than in serous and clear cell tumors. In some serous and most clear cell tumors, ALDH1A1 expression was found in the stromal fibroblasts. RNA expression of all studied ALDH isozymes also showed higher expression in endometrioid and mucinous tumors than in the serous and clear cell subtypes. The expression of ALDH enzymes showed tumor type-dependent induction in ovarian cancer cells growing as sphere suspensions in serum-free medium. The results of our study indicate that ALDH enzyme expression and activity may be associated with specific cell types in ovarian tumor tissues and vary according to

  11. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

    Science.gov (United States)

    Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

    2015-01-01

    Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  12. Identification of crucial amino acids in mouse aldehyde oxidase 3 that determine substrate specificity.

    Directory of Open Access Journals (Sweden)

    Martin Mahro

    Full Text Available In order to elucidate factors that determine substrate specificity and activity of mammalian molybdo-flavoproteins we performed site directed mutagenesis of mouse aldehyde oxidase 3 (mAOX3. The sequence alignment of different aldehyde oxidase (AOX isoforms identified variations in the active site of mAOX3 in comparison to other AOX proteins and xanthine oxidoreductases (XOR. Based on the structural alignment of mAOX3 and bovine XOR, differences in amino acid residues involved in substrate binding in XORs in comparison to AOXs were identified. We exchanged several residues in the active site to the ones found in other AOX homologues in mouse or to residues present in bovine XOR in order to examine their influence on substrate selectivity and catalytic activity. Additionally we analyzed the influence of the [2Fe-2S] domains of mAOX3 on its kinetic properties and cofactor saturation. We applied UV-VIS and EPR monitored redox-titrations to determine the redox potentials of wild type mAOX3 and mAOX3 variants containing the iron-sulfur centers of mAOX1. In addition, a combination of molecular docking and molecular dynamic simulations (MD was used to investigate factors that modulate the substrate specificity and activity of wild type and AOX variants. The successful conversion of an AOX enzyme to an XOR enzyme was achieved exchanging eight residues in the active site of mAOX3. It was observed that the absence of the K889H exchange substantially decreased the activity of the enzyme towards all substrates analyzed, revealing that this residue has an important role in catalysis.

  13. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

    Directory of Open Access Journals (Sweden)

    Feng-Xia Tian

    Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  14. Perturbation of formate pathway for hydrogen production by expressions of formate hydrogen lyase and its transcriptional activator in wild Enterobacter aerogenes and its mutants

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yuan; Zhao, Hongxin; Zhang, Chong; Lai, Qiheng; Xing, Xin-Hui [Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2009-06-15

    To examine perturbation effects of formate pathway on hydrogen productivity in Enterobacter aerogenes (Ea), formate dehydrogenase FDH-H gene (fdhF) and formate hydrogen lyase activator protein FHLA gene (fhlA) originated from Escherichia coli, were overexpressed in the wild strain Ea, its hycA-deleted mutant (A) by knockout the formate hydrogen lyase repressor and hybO-deleted mutant (O) by knockout of the uptake hydrogenase, respectively. Overexpression of fdhF and fhlA promoted cell growth and volumetric hydrogen production rates of all the strains, and the hydrogen production per gram cell dry weight (CDW) for Ea, A and O was increased by 38.5%, 21.8% and 5.25%, respectively. The fdhF and fhlA overexpression improved the hydrogen yield per mol glucose of strains Ea and A, but declined that of strain O. The increase of hydrogen yield of the strain Ea with fdhF and fhlA expression was mainly attributed to the increase of formate pathway, while for the mutant A, the improved hydrogen yield with fdhF and fhlA expression was mainly due to the increase of NADH pathway. Analysis of the metabolites and ratio of ethanol-to-acetate showed that the cellular redox state balance and energy level were also changed for these strains by fdhF and fhlA expression. These findings demonstrated that the hydrogen production was not only dependent on the hydrogenase genes, but was also affected by the regulation of the whole metabolism. Therefore, fdhF and fhlA expression in different strains of E. aerogenes could exhibit different perturbation effects on the metabolism and the hydrogen productivity. (author)

  15. Formylbenzene diazonium hexafluorophosphate reagent for tyrosine-selective modification of proteins and the introduction of a bioorthogonal aldehyde.

    Science.gov (United States)

    Gavrilyuk, Julia; Ban, Hitoshi; Nagano, Masanobu; Hakamata, Wataru; Barbas, Carlos F

    2012-12-19

    4-Formylbenzene diazonium hexafluorophosphate (FBDP) is a novel bench-stable crystalline diazonium salt that reacts selectively with tyrosine to install a bioorthogonal aldehyde functionality. Model studies with N-acyl-tyrosine methylamide allowed us to identify conditions optimal for tyrosine ligation reactions with small peptides and proteins. FBDP-based conjugation was used for the facile introduction of small molecule tags, poly(ethylene glycol) chains (PEGylation), and functional small molecules onto model proteins and to label the surface of living cells.

  16. Aldehyde Dehydrogenase-2 (ALDH2) Ameliorates Chronic Alcohol Ingestion-Induced Myocardial Insulin Resistance and Endoplasmic Reticulum Stress

    OpenAIRE

    Li, Shi-Yan; Gilbert, Sara A.B.; Li, Qun; Ren, Jun

    2009-01-01

    Chronic alcohol intake leads to insulin resistance and alcoholic cardiomyopathy, which appears to be a result of the complex interaction between genes and environment. This study was designed to examine the impact of aldehyde dehydrogenase-2 (ALDH2) transgenic overexpression on alcohol-induced insulin resistance and myocardial injury. ALDH2 transgenic mice were produced using chicken β-actin promoter. Wild-type FVB and ALDH2 mice were fed a 4% alcohol or control diet for 12 wks. Cell shorteni...

  17. Asymmetric Baylis-Hillman Reaction between Chiral Activated Alkenes and Aromatic Aldehydes in Me3N/H2O/Solvent Medium

    Institute of Scientific and Technical Information of China (English)

    Ke HE; Zheng Hong ZHOU; Hong Ying TANG; Guo Feng ZHAO; Chu Chi TANG

    2005-01-01

    Chiral activated alkene, L-menthyl acrylate and (+)-N-α-phenylethyl acrylamide,induced asymmetric Baylis-Hillman reaction of aromatic aldehydes was realized at 25℃ for 7 days in Me3N/H2O/solvent homogeneous medium. The corresponding Baylis-Hillman adducts were obtained in good chemical yield with moderate to excellent diastereoselectivity (up to 99% de).

  18. Evaluation of alcohol dehydrogenase and aldehyde dehydrogenase enzymes as bi-enzymatic anodes in a membraneless ethanol microfluidic fuel cell

    Science.gov (United States)

    Galindo-de-la-Rosa, J.; Arjona, N.; Arriaga, L. G.; Ledesma-García, J.; Guerra-Balcázar, M.

    2015-12-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldH) enzymes were immobilized by covalent binding and used as the anode in a bi-enzymatic membraneless ethanol hybrid microfluidic fuel cell. The purpose of using both enzymes was to optimize the ethanol electro-oxidation reaction (EOR) by using ADH toward its direct oxidation and AldH for the oxidation of aldehydes as by-products of the EOR. For this reason, three enzymatic bioanode configurations were evaluated according with the location of enzymes: combined, vertical and horizontally separated. In the combined configuration, a current density of 16.3 mA cm-2, a voltage of 1.14 V and a power density of 7.02 mW cm-2 were obtained. When enzymes were separately placed in a horizontal and vertical position the ocp drops to 0.94 V and to 0.68 V, respectively. The current density also falls to values of 13.63 and 5.05 mA cm-2. The decrease of cell performance of bioanodes with separated enzymes compared with the combined bioanode was of 31.7% and 86.87% for the horizontal and the vertical array.

  19. AAV Gene Therapy for Alcoholism: Inhibition of Mitochondrial Aldehyde Dehydrogenase Enzyme Expression in Hepatoma Cells.

    Science.gov (United States)

    Sanchez, Anamaria C; Li, Chengwen; Andrews, Barbara; Asenjo, Juan A; Samulski, R Jude

    2017-09-01

    Most ethanol is broken down in the liver in two steps by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH2) enzymes, which metabolize down ethanol into acetaldehyde and then acetate. Some individuals from the Asian population who carry a mutation in the aldehyde dehydrogenase gene (ALDH2*2) cannot metabolize acetaldehyde as efficiently, producing strong effects, including facial flushing, dizziness, hypotension, and palpitations. This results in an aversion to alcohol intake and protection against alcoholism. The large prevalence of this mutation in the human population strongly suggests that modulation of ALDH2 expression by genetic technologies could result in a similar phenotype. scAAV2 vectors encoding ALDH2 small hairpin RNA (shRNA) were utilized to validate this hypothesis by silencing ALDH2 gene expression in human cell lines. Human cell lines HEK-293 and HepG2 were transduced with scAAV2/shRNA, showing a reduction in ALDH2 RNA and protein expression with the two viral concentration assayed (1 × 10 4 and 1 × 10 5 vg/cell) at two different time points. In both cell lines, ALDH2 RNA levels were reduced by 90% and protein expression was inhibited by 90% and 52%, respectively, 5 days post infection. Transduced HepG2 VL17A cells (ADH+) exposed to ethanol resulted in a 50% increase in acetaldehyde levels. These results suggest that gene therapy could be a useful tool for the treatment of alcoholism by knocking down ALDH2 expression using shRNA technology delivered by AAV vectors.

  20. Enantioselective allylations of selected alpha, beta, gamma, delta-unsaturated aldehydes by axially chiral N,N'-dioxides. Synthesis of the left-hand part of papulacandin D

    Czech Academy of Sciences Publication Activity Database

    Vlašaná, K.; Betík, R.; Valterová, Irena; Nečas, D.; Kotora, M.

    2016-01-01

    Roč. 3, č. 3 (2016), s. 301-305 ISSN 2213-3372 Institutional support: RVO:61388963 Keywords : allylation * aldehyde * Lewis base * asymmetric synthesis * organocatalysis * homoallylic alcohol s Subject RIV: CC - Organic Chemistry