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Sample records for acyl radicals

  1. Acyl Radicals from Aromatic Carboxylic Acids by Means of Visible-Light Photoredox Catalysis

    Bergonzini, Giulia; Cassani, Carlo; Wallentin, Carl-Johan

    2015-01-01

    Simple and abundant carboxylic acids have been used as acyl radical precursor by means of visible-light photoredox catalysis. By the transient generation of a reactive anhydride intermediate, this redox-neutral approach offers a mild and rapid entry to high-value heterocyclic compounds without the need of UV irradiation, high temperature, high CO pressure, tin reagents, or peroxides.

  2. Closing the peroxy acetyl (PA radical budget: observations of acyl peroxy nitrates (PAN, PPN, and MPAN during BEARPEX 2007

    B. W. LaFranchi

    2009-04-01

    Full Text Available Acyl peroxy nitrates (APNs, also known as PANs are formed from the oxidation of aldehydes and other oxygenated VOC (oVOC in the presence of NO2. Formation of APNs suppresses NOx (NOx≡NO+NO2 in urban areas and enhances NOx downwind in urban plumes, increasing the rate of ozone production throughout an urban plume. APNs also redistribute NOx on global scales, enhancing NOx and thus ozone production. There are both anthropogenic and biogenic oVOC precursors to APNs, but a detailed evaluation of their chemistry against observations has proven elusive. Here we describe measurements of PAN, PPN, and MPAN along with the majority of chemicals that participate in their production and loss, including OH, HO2, numerous oVOC, and NO2. Observations were made during the Biosphere Effects on AeRosols and Photochemistry Experiment (BEARPEX 2007 in the outflow of the Sacramento urban plume. These observations are used to evaluate a detailed chemical model of APN ratios and concentrations. We find the ratios of APNs are nearly independent of the loss mechanisms and thus an especially good test of our understanding of their sources. We show that oxidation of methylvinyl ketone, methacrolein, methyl glyoxal, biacetyl and acetaldehyde are all significant sources of the PAN+peroxy acetyl (PA radical reservoir, with methylvinyl ketone (MVK often being the primary non-acetaldehyde source. At high temperatures, oxidation of non-acetaldehyde PA radical sources contributes over 60% to the total PA production rate. An analysis of absolute APN concentrations reveals a missing APN sink that can be resolved by increasing the PA+∑RO2 rate constant by a factor of 3.

  3. Study on stability and oxygen radicals scavenging capacity of acylated blueberries anthocyanins%酰基化蓝莓花色苷的稳定性和对氧自由基清除能力

    李颖畅; 李冰心; 吕春茂; 孟宪军

    2012-01-01

    The instability of natural anthocyanins was a big obstacle for its usage in food as colorants.In order to improve the stability of anthocyanins, molecular modification was used.The molecular modification of blueberry anthocyanins by acylation, the light, thermal stability and scavenging oxygen radicals of acylated anthocyanins were studied.The UV absorption spectrum and infrared spectrum showed that the blueberry anthocyanins had been acylated.Light and heat stability of acylated anthocyanins were significantly increased being compared with no acylated anthocyanins, but the capability of acylated anthocyanins on scavenging the hydroxyl radical, superoxide anion radical were weaker than those no acylated anthocyanins.lC~0 of scavenging hydroxyl radical and superoxide anion was 0.74,3.14mg/mL, respectively.%由于天然花色苷稳定性差,严重阻碍了其在食品工业中的广泛应用。为了改善花色苷的稳定性,采用分子修饰的方法,通过酰基化反应修饰蓝莓花色苷,并研究酰化后蓝莓花色苷的光、热稳定性和对氧自由基的清除能力。通过紫外吸收光谱和红外光谱表明蓝莓花色苷已经酰基化。相对未酰化的蓝莓花色苷,酰基化蓝莓花色苷的光、热稳定性显著提高,但清除羟基自由基、超氧阴离子自由基的能力略有下降,清除羟自由基、超氧阴离子自由基的IC,。分别为0.74、3.14mg/mL。

  4. Radicals

    Jahn, Ullrich; Cornils, B.

    Weinheim: Wiley-VCH, 2013 - (Cornils, B.; Herrmann, W.; Wong, C.; Zanthoff, H.), s. 1897-1898 ISBN 978-3-527-33307-3 Institutional support: RVO:61388963 Keywords : radicals * enzymatic catalysis * coenzyme B12 * ribonucleotide reductase * mutases Subject RIV: CC - Organic Chemistry

  5. Oxidative acylation using thioacids

    Liu, R.; Orgel, L. E.

    1997-01-01

    Several important prebiotic reactions, including the coupling of amino acids into polypeptides by the formation of amide linkages, involve acylation. Theae reactions present a challenge to the understanding of prebiotic synthesis. Condensation reactions relying on dehydrating agents are either inefficient in aqueous solution or require strongly acidic conditions and high temperatures. Activated amino acids such as thioester derivatives have therefore been suggested as likely substrates for prebiotic peptide synthesis. Here we propose a closely related route to amide bond formation involving oxidative acylation by thioacids. We find that phenylalanine, leucine and phenylphosphate are acylated efficiently in aqueous solution by thioacetic acid and an oxidizing agent. From a prebiotic point of view, oxidative acylation has the advantage of proceeding efficiently in solution and under mild conditions. We anticipate that oxidative acylation should prove to be a general method for activating carboxylic acids, including amino acids.

  6. Acyl-acyl carrier protein: Lysomonogalactosyldiacylglycerol acyl transferase in Anabaena variabilis

    Monogalactosyldiacylglycerol was produced when membranes isolated from the cyanobacterium, Anabaena variabilis, and washed free of soluble endogenous constituents, were incubated with (14C)acyl-acyl carrier protein. This enzymatic synthesis of monogalactosyldiacylglycerol localized in the membranes was not dependent on any added cofactors, such as ATP, coenzyme A, and dithiothreitol. Palmitoyl-, stearoyl-, and oleoyl-acyl carrier proteins were approximately equally active as substrates with Km of 0.37, 0.36, and 0.23 μM, respectively. The (14C)acyl group was exclusively transferred to the sn-1 hydroxyl of the glycerol backbone of monogalactosyldiacylglycerol as demonstrated by hydrolysis of all incorporated acyl groups by the lipase from Rhizopus arrhizus delamar. Using a double labelled (14C)acyl-(14C)acyl carrier protein, this enzyme catalyzed the direct transfer of the acyl group from acyl-acyl carrier protein to an endogenous lysomonogalactosyldiacylglycerol to form monogalactosyldiacylglycerol. The transfer reaction mechanism was also confirmed by the increased activity with the addition of the lysomonogalactosyldiacylglycerol suspension. A specific galactolipid acyl hydrolase activity was released into the soluble protein fraction when the membranes of Anabaena variabilis were treated with 2% Triton X-100. The positional specificity of this acyl hydrolase was demonstrated to be similar to that of Rhizopus lipase, i.e. only the acyl group at the sn-1 position was hydrolyzed. The acyl hydrolase which was also localized in the membrane fraction of Anabaena variabilis was presumably responsible for producing endogenous lysomonogalactosyldiacylglycerol used by the acyltransferase

  7. Enzymatic acylation of starch.

    Alissandratos, Apostolos; Halling, Peter J

    2012-07-01

    Starch a cheap, abundant and renewable natural material has been chemically modified for many years. The popular modification acylation has been used to adjust rheological properties as well as deliver polymers with internal plasticizers and other potential uses. However the harsh reaction conditions required to produce these esters may limit their use, especially in sensitive applications (foods, pharmaceuticals, etc.). The use of enzymes to catalyse acylation may provide a suitable alternative due to high selectivities and mild reaction conditions. Traditional hydrolase-catalysed synthesis in non-aqueous apolar media is hard due to lack of polysaccharide solubility. However, acylated starch derivatives have recently been successfully produced in other non-conventional systems: (a) surfactant-solubilised subtilisin and suspended amylose in organic media; (b) starch nanoparticles dispersed in organic medium with immobilised lipase; (c) aqueous starch gels with lipase and dispersed fatty acids. We attempt a systematic review that draws parallels between the seemingly unrelated approaches described. PMID:22138593

  8. Preparation and Characterization of Acylated Chitosan

    LI Ming-chun; LIU Chao; XIN Mei-hua; ZHAO Huang; WANG Min; FENG Zhen; SUN Xiao-li

    2005-01-01

    Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends on the volume ratio of pyridine to chloroform in the reaction medium, the chain length of the acylation agent used, and the molecular weight of chitosan raw materials. The XRD measurements were carried out for pure chitosan, fully acylated chitosan and N, N-diacyl chitosan to verify the crystallinity change caused by the acylation.

  9. RNA SHAPE chemistry with aromatic acylating reagents.

    Nodin, Laura; Noël, Olivier; Chaminade, Françoise; Maskri, Ouerdia; Barbier, Vincent; David, Olivier; Fossé, Philippe; Xie, Juan

    2015-02-01

    As chemical methods for RNA secondary structure determination, SHAPE chemistry (selective 2'-hydroxyl acylation analyzed by primer extension) has been developed to specifically target flexible nucleotides (often unpaired nucleotides) independently to their purine or pyrimidine nature. In order to improve the specificity of acylating reagents towards unpaired nucleotides, we have explored the reactivity of symmetric anhydrides, acyl fluorides, active esters like succinimidyl ester and cyanomethyl esters for 2'-O-acylation reaction. Among the tested compounds, only the acyl fluoride 4 showed a low reactivity (compared to NMIA). However, this study is the first to show that nucleophilic catalysts like DMAP greatly improved the selective 2'-hydroxyl acylation by symmetric anhydrides, acyl fluorides and succinimidyl ester, with the 2-fluorobenzoic anhydride 5 being the most reactive. PMID:25557357

  10. Acyl-CoA metabolism and partitioning

    Grevengoed, Trisha J; Klett, Eric L; Coleman, Rosalind A

    2014-01-01

    expression patterns and subcellular locations. Their acyl-CoA products regulate metabolic enzymes and signaling pathways, become oxidized to provide cellular energy, and are incorporated into acylated proteins and complex lipids such as triacylglycerol, phospholipids, and cholesterol esters. Their differing...... metabolic fates are determined by a network of proteins that channel the acyl-CoAs toward or away from specific metabolic pathways and serve as the basis for partitioning. This review evaluates the evidence for acyl-CoA partitioning by reviewing experimental data on proteins that are believed to contribute...

  11. Acylated flavone glycosides from Veronica

    Albach, Dirk C.; Grayer, Renée J.; Jensen, Søren Rosendal;

    2003-01-01

    A survey of the flavonoid glycosides of selected taxa in the genus Veronica yielded two new acylated 5,6,7,3',4'-pentahydroxyflavone (6-hydroxyluteolin) glycosides and two rare allose-containing acylated 5,7,8,4'-tetrahydroxyflavone (isoscutellarein) glycosides. The new compounds were isolated from...... Veronica (melittoside and globularifolin) were also isolated from V. intercedens....

  12. Acylated anthocyanins from sprouts of Raphanus sativus cv. Sango: isolation, structure elucidation and antioxidant activity.

    Matera, Riccardo; Gabbanini, Simone; Berretti, Serena; Amorati, Riccardo; De Nicola, Gina Rosalinda; Iori, Renato; Valgimigli, Luca

    2015-01-01

    Little is known on structure-activity relationships of antioxidant anthocyanins. Raphanus sativus cv Sango sprouts are among the richest sources (270 mg/100 g fresh weight). We isolated from sprouts' juice 9 acylated anthocyanins, including 4 new compounds. All comprise a cyanidin core bearing 3-4 glucose units, multiply acylated with malonic and phenolic acids (ferulic and sinapic). All compounds were equally effective in inhibiting the autoxidation of linoleic acid in aqueous micelles, with rate constant for trapping peroxyl radicals kinh=(3.8 ± 0.7) × 10(4)M(-1)s(-1) at 37 °C. In acetonitrile solution kinh varied with acylation: (0.9-2.1) × 10(5)M(-1)s(-1) at 30 °C. Each molecule trapped a number n of peroxyl radicals ranging from 4 to 7. Anthocyanins bearing sinapic acid were more effective than those bearing the ferulic moiety. Under identical settings, deacylated cyanin, ferulic and sinapic acids had kinh of 0.4 × 10(5), 0.3 × 10(5) and 1.6 × 10(5)M(-1)s(-1) respectively, with n ranging 2-3. Results show the major role of acylation on antioxidant performance. PMID:25053073

  13. Stability-increasing effects of anthocyanin glycosyl acylation.

    Zhao, Chang-Ling; Yu, Yu-Qi; Chen, Zhong-Jian; Wen, Guo-Song; Wei, Fu-Gang; Zheng, Quan; Wang, Chong-De; Xiao, Xing-Lei

    2017-01-01

    This review comprehensively summarizes the existing knowledge regarding the chemical implications of anthocyanin glycosyl acylation, the effects of acylation on the stability of acylated anthocyanins and the corresponding mechanisms. Anthocyanin glycosyl acylation commonly refers to the phenomenon in which the hydroxyl groups of anthocyanin glycosyls are esterified by aliphatic or aromatic acids, which is synthetically represented by the acylation sites as well as the types and numbers of acyl groups. Generally, glycosyl acylation increases the in vitro and in vivo chemical stability of acylated anthocyanins, and the mechanisms primarily involve physicochemical, stereochemical, photochemical, biochemical or environmental aspects under specific conditions. Additionally, the acylation sites as well as the types and numbers of acyl groups influence the stability of acylated anthocyanins to different degrees. This review could provide insight into the optimization of the stability of anthocyanins as well as the application of suitable anthocyanins in food, pharmaceutical and cosmetic industries. PMID:27507456

  14. Novel Synthesis and Characterization of Thiosemicarbazone Compounds Containing 4-Acyl-2-pyrazolin-5-ones

    Arjun K. Rana; Parekh, Nayan R.; Dabhi, Harish R.; Nadkarni, Sunil S.

    2009-01-01

    A novel synthesis of 4-acylthiosemicarbazone-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one by condensation of 4-acyl-3-methyl-1-(4`-methylphenyl)-2-pyrazolin-5-one with thiosemicarbazide is carried out. The compounds were characterized on the basis of elemental analysis, IR, 1H NMR, Mass, DSC and 13C NMR spectral data. The structures were investigated for their antibacterial and antifungal activity. They are very essential to study on cerebral infarction (Free radical scavenger). A single cr...

  15. Acyl-coenzyme A organizes laterally in membranes and is recognized specifically by acyl-coenzyme A binding protein

    Cohen Simonsen, A; Bernchou Jensen, U; Færgeman, Nils J.; Knudsen, J; Mouritsen, O G

    Long chain acyl-coenzyme A (acyl-CoA) is a biochemically important amphiphilic molecule that is known to partition strongly into membranes by insertion of the acyl chain. At present, microscopically resolved evidence is lacking on how acyl-CoA influences and organizes laterally in membranes. By a...

  16. Fatty acyl-CoA reductase

    Reiser, Steven E.; Somerville, Chris R.

    1998-12-01

    The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.

  17. Radical Evil

    Carlos Manrique

    2007-12-01

    Full Text Available There is an aporia in Kant’s analysis of evil: he defines radical evilas an invisible disposition of the will, but he also demands an inferential connection between visible evil actions and this invisible disposition. This inference,however, undermines the radical invisibility of radical evil according to Kant’s own definition of the latter. Noting how this invisibility of moral worth is a distinctive feature of Kant’s approach to the moral problem, the paper then asks why, in the Groundwork, he nonetheless forecloses a question about evil that seems to be consistent with this approach. It is argued that to account for this aporia and this foreclosure, one has to interrogate the way in which the category of religion orients Kant’s incipient philosophy of history in Die Religion.

  18. Role of acylCoA binding protein in acylCoA transport, metabolism and cell signaling

    Knudsen, J; Jensen, M V; Hansen, J K; Færgeman, Nils J.; Neergaard, T B; Gaigg, B

    Long chain acylCoA esters (LCAs) act both as substrates and intermediates in intermediary metabolism and as regulators in various intracellular functions. AcylCoA binding protein (ACBP) binds LCAs with high affinity and is believed to play an important role in intracellular acylCoA transport and ......) [4]. Additional factors affecting the concentration of free LCA include feed back inhibition of the acylCoA synthetase [5], binding to acylCoA receptors (LCA-regulated molecules and enzymes), binding to membranes and the activity of acylCoA hydrolases [6]....

  19. Radical Geography

    H. Hataminezhad

    2012-07-01

    Full Text Available Interdisciplinary sciences emerging and specialization were result of historical conditions. Lack of common and grand theories have caused social sciences such as Geography disintegrated to many courses. The Geography science has been divided two main courses, Physical and Human through the time. Every one used another similar science in theoretical principles and methodologies for their domain development and strengthening of their bases. The Human Geography was influenced by Anthropology during nineteenth century and was affected by nineteenth century and dawn twentieth century by Sociology and from mid twentieth century until present time by Biological sciences, Psychology, Political economics and social theories. Radical Geography was one of the Human Geography branches that was influenced by Political economics and left ideology. Radical Geography emphasizes on investigation about quality of life in different spaces and attempts to change socio-economic and spatial relationships, therefore critical Geography is one of its similar approaches.

  20. Minimizing acylation of peptides in PLGA microspheres

    Zhang, Ying; Schwendeman, Steven P.

    2012-01-01

    The main objective of this study was to characterize and find mechanisms to prevent acylation of therapeutic peptides encapsulated in glucose-star poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres. The effect of addition of divalent cation salts CaCl2, MnCl2 as well as carboxymethyl chitosan (CMCS) on inhibition of acylation of octreotide (Oct), salmon calcitonin (sCT), and human parathyroid hormone (hPTH) was evaluated. Peptide content and integrity inside the degrading microspheres was ...

  1. Acyl silicates and acyl aluminates as activated intermediates in peptide formation on clays

    White, D. H.; Kennedy, R. M.; Macklin, J.

    1984-01-01

    Glycine reacts with heating on dried clays and other minerals to give peptides in much better yield than in the absence of mineral. This reaction was proposed to occur by way of an activated intermediate such as an acyl silicate or acyl aluminate analogous to acyl phosphates involved in several biochemical reactions including peptide bond synthesis. The proposed mechanism has been confirmed by trapping the intermediate, as well as by direct spectroscopic observation of a related intermediate. The reaction of amino acids on periodically dried mineral surfaces represents a widespead, geologically realistic setting for prebiotic peptide formation via in situ activation.

  2. Roaming Radicals

    Bowman, Joel M.; Shepler, Benjamin C.

    2011-05-01

    Roaming is a recently verified unusual pathway to molecular products from unimolecular dissociation of an energized molecule. Here we present the evidence for this pathway for H2CO and CH3CHO. Theoretical analysis shows that this path visits the plateau region of the potential energy surface near dissociation to radical products. It is not clear whether roaming is a distinct isolated pathway, in addition to the conventional one via the well-known molecular saddle-point transition state. Evidence is presented to suggest that the two pathways may originate from a single, but highly complicated, dividing surface. Other examples of unusual reaction dynamics are also reviewed.

  3. High acyl gellan as an emulsion stabilizer.

    Vilela, Joice Aline Pires; Cunha, Rosiane Lopes da

    2016-03-30

    High acyl gellan (0.01-0.2% w/w) was used as stabilizer in oil in water emulsions containing 30% (w/w) of sunflower oil and prepared under different process conditions. Stable emulsions to phase separation could be obtained using high acyl gellan (HA) content above 0.05% (w/w), while low acyl gellan (LA) prepared at the same conditions could not stabilize emulsions. Emulsions properties depended on the process used to mix the oil and gellan dispersion since high pressure homogenization favored stabilization while very high energy density applied by ultrasound led to systems destabilization. Emulsions prepared using high pressure homogenization showed zeta potential values ranging from -50 up to -59mV, suggesting that electrostatic repulsion could be contributing to the systems stability. Rheological properties of continuous phase were also responsible for emulsions stabilization, since HA gellan dispersions showed high viscosity and gel-like behavior. The high viscosity of the continuous phase could be associated to the presence of high acyl gellan microgels/aggregates. Disentanglement of these aggregates performed by ultrasound strongly decreased the viscosity and consequently affected the emulsions behavior, reducing the stability to phase separation. PMID:26794954

  4. Head-group acylation of monogalactosyldiacylglycerol is a common stress response, and the acyl-galactose acyl composition varies with the plant species and applied stress.

    Vu, Hieu Sy; Roth, Mary R; Tamura, Pamela; Samarakoon, Thilani; Shiva, Sunitha; Honey, Samuel; Lowe, Kaleb; Schmelz, Eric A; Williams, Todd D; Welti, Ruth

    2014-04-01

    Formation of galactose-acylated monogalactosyldiacylglycerols has been shown to be induced by leaf homogenization, mechanical wounding, avirulent bacterial infection and thawing after snap-freezing. Here, lipidomic analysis using mass spectrometry showed that galactose-acylated monogalactosyldiacylglycerols, formed in wheat (Triticum aestivum) and tomato (Solanum lycopersicum) leaves upon wounding, have acyl-galactose profiles that differ from those of wounded Arabidopsis thaliana, indicating that different plant species accumulate different acyl-galactose components in response to the same stress. Additionally, the composition of the acyl-galactose component of Arabidopsis acMGDG (galactose-acylated monogalactosyldiacylglycerol) depends on the stress treatment. After sub-lethal freezing treatment, acMGDG contained mainly non-oxidized fatty acids esterified to galactose, whereas mostly oxidized fatty acids accumulated on galactose after wounding or bacterial infection. Compositional data are consistent with acMGDG being formed in vivo by transacylation with fatty acids from digalactosyldiacylglycerols. Oxophytodienoic acid, an oxidized fatty acid, was more concentrated on the galactosyl ring of acylated monogalactosyldiacylglycerols than in galactolipids in general. Also, oxidized fatty acid-containing acylated monogalactosyldiacylglycerols increased cumulatively when wounded Arabidopsis leaves were wounded again. These findings suggest that, in Arabidopsis, the pool of galactose-acylated monogalactosyldiacylglycerols may serve to sequester oxidized fatty acids during stress responses. PMID:24286212

  5. Enzymatic Acylation of Anthocyanin Isolated from Black Rice with Methyl Aromatic Acid Ester as Donor: Stability of the Acylated Derivatives.

    Yan, Zheng; Li, Chunyang; Zhang, Lixia; Liu, Qin; Ou, Shiyi; Zeng, Xiaoxiong

    2016-02-10

    The enzymatic acylation of anthocyanin from black rice with aromatic acid methyl esters as acyl donors and Candida antarctica lipase B was carried out under reduced pressure. The highest conversion of 91% was obtained with benzoic acid methyl ester as acyl donor; cyanidin 3-(6″-benzoyl)-glucoside, cyanidin 3-(6″-salicyloyl)-glucoside, and cyanidin 3-(6″-cinnamoyl)-glucoside were successfully synthesized. This is the first report on the enzymatic acylation of anthocyanin from black rice with methyl aromatic esters as acyl donors and lipase as biocatalyst. Furthermore, the acylation with aromatic carboxylic acids enhanced both the thermostability and light resistivity of anthocyanin. In particular, cyanidin 3-(6″-cinnamoyl)-glucoside was the most stable among the three acylated anthocyanins synthesized. PMID:26766135

  6. Purification and characterization of fatty acyl-acyl carrier protein synthetase from Vibrio harveyi.

    Fice, D; Shen, Z; Byers, D M

    1993-01-01

    A Vibrio harveyi enzyme which catalyzes the ATP-dependent ligation of fatty acids to acyl carrier protein (ACP) has been purified 6,000-fold to apparent homogeneity by anion-exchange, gel filtration, and ACP-Sepharose affinity chromatography. Purified acyl-ACP synthetase migrated as a single 62-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as an 80-kDa protein by gel filtration under reducing conditions. Activity of the purified enzyme was lost within hours in the absence of glycerol and low concentrations of Triton X-100. Acyl-ACP synthetase exhibited Kms for myristic acid, ACP, and ATP of 7 microM, 18 microM, and 0.3 mM, respectively. The enzyme was specific for adenine-containing nucleotides, and AMP was the product of the reaction. No covalent acyl-enzyme intermediate was observed. Enzyme activity was stimulated up to 50% by iodoacetamide but inhibited > 80% by N-ethylmaleimide: inhibition by the latter was prevented by ATP and ACP but not myristic acid. Dithiothreitol and sulfhydryl-directed reagents also influenced enzyme size, activity, and elution pattern on anion-exchange resins. The function of acyl-ACP synthetase has not been established, but it may be related to the capacity of V. harveyi to elongate exogenous fatty acids by an ACP-dependent mechanism. Images PMID:8384617

  7. Acylation of Toluene with Isobutyryl Chloride

    Čejka, Jiří; Klisáková, Jana; Žilková, Naděžda; Červený, L.

    Cape Town, 2004 - ( Steen van, E.), s. 2717-2723 ISBN 0-958-46636-X. [International Zeolite Conference /14./. Cape Town (ZA), 25.04.2004-30.04.2004] R&D Projects: GA ČR GA203/03/0804 Institutional research plan: CEZ:AV0Z4040901 Keywords : acylation of toluene * isobutyryl chloride * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry

  8. Applying Acylated Fucose Analogues to Metabolic Glycoengineering

    Julia Rosenlöcher; Verena Böhrsch; Michael Sacharjat; Véronique Blanchard; Christoph Giese; Volker Sandig; Christian P R Hackenberger; Stephan Hinderlich

    2015-01-01

    Manipulations of cell surface glycosylation or glycan decoration of selected proteins hold immense potential for exploring structure-activity relations or increasing glycoprotein quality. Metabolic glycoengineering describes the strategy where exogenously supplied sugar analogues intercept biosynthetic pathways and are incorporated into glycoconjugates. Low membrane permeability, which so far limited the large-scale adaption of this technology, can be addressed by the introduction of acylated...

  9. Lipid radicals: Properties and detection by spin trapping

    Unsaturated lipids are rapidly oxidized to toxic products such as lipid hydroperoxides, especially when transition metals such as iron or copper are present. In a Fenton-type reaction Fe2+ converts lipid hydroperoxides to the very short-lived lipid alkoxyl radicals. The reaction was started upon the addition of Fe2+ to an aqueous linoleic acid hydroperoxide (LOOH) emulsion and the spin trap in the absence of oxygen. Even when high concentrations of spin traps were added to the incubation mixture, only secondary radical adducts were detected, probably due to the rapid rearrangement of the primary alkoxyl radicals. With the commercially available nitroso spin trap MNP we observed a slightly immobilized ESR spectrum with only one hydrogen splitting, indicating the trapping of a methinyl fragment of a lipid radical. With DMPO or 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO) adducts were detected with carbon-centered lipid radical, with acyl radical, and with the hydroxyl radical. We also synthesized lipophilic derivatives of the spin trap DEPMPO in order to detect lipid radical species generated in the lipid phase. With all spin traps studied a lipid-derived carbon-centered radical was obtained in the anaerobic incubation system Fe2+/LOOH indicating the trapping of a lipid radical, possibly generated as a secondary reaction product of the primary lipid alkoxyl radical formed. Under aerobic conditions an SOD-insensitive oxygen-centered radical adduct was formed with DEPMPO and its lipophilic derivatives. The observed ESR parameters were similar to those of alkoxyl radical adducts, which were independently synthesized in model experiments using Fe3+-catalyzed nucleophilic addition of methanol or t-butanol to the respective spin trap. (author)

  10. Purification and characterization of fatty acyl-acyl carrier protein synthetase from Vibrio harveyi.

    Fice, D; Z. Shen; Byers, D M

    1993-01-01

    A Vibrio harveyi enzyme which catalyzes the ATP-dependent ligation of fatty acids to acyl carrier protein (ACP) has been purified 6,000-fold to apparent homogeneity by anion-exchange, gel filtration, and ACP-Sepharose affinity chromatography. Purified acyl-ACP synthetase migrated as a single 62-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as an 80-kDa protein by gel filtration under reducing conditions. Activity of the purified enzyme was lost within hours in the ...

  11. N-acylation of ethanolamine using lipase: a chemoselective catalyst

    Mazaahir Kidwai; Roona Poddar; Poonam Mothsra

    2009-01-01

    The N-acylation of ethanolamine (2) with various fatty acids 1a–d and esters of fatty acids 1e–h using Candida antarctica B lipase (Novozym® 435) are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy between the enzyme catalysis and microwave irradiation.

  12. N-acylation of ethanolamine using lipase: a chemoselective catalyst

    Mazaahir Kidwai

    2009-03-01

    Full Text Available The N-acylation of ethanolamine (2 with various fatty acids 1a–d and esters of fatty acids 1e–h using Candida antarctica B lipase (Novozym® 435 are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy between the enzyme catalysis and microwave irradiation.

  13. Plasma levels of acylated ghrelin in patients with functional dyspepsia

    Yeon Soo Kim; Joon Seong Lee; Tae Hee Lee; Joo Young Cho; Jin Oh Kim; Wan Jung Kim; Hyun Gun Kim; Seong Ran Jeon; Hoe Su Jeong

    2012-01-01

    AIM:To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS:Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study.The functional dyspepsia patients were each diagnosed based on the Rome Ⅲ criteria.Eligible patients completed a questionnaire concerning the severity of 10 symptoms.Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit; electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal.RESULTS:There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia.However,in patients with functional dyspepsia,there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain (r =-0.427,P =0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety (r =0.428,P =0.047).Additionally,there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria (%) (r =-0.522,P =0.013).Interestingly,two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal.CONCLUSION:Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia.

  14. Acyl-acyl carrier protein as a source of fatty acids for bacterial bioluminescence

    Pulse-chase experiments with [3H]tetradecanoic acid and ATP showed that the bioluminescence-related 32-kDa acyltransferase from Vibrio harveyi can specifically catalyze the deacylation of a 3H-labeled 18-kDa protein observed in extracts of this bacterium. The 18-kDa protein has been partially purified and its physical and chemical properties strongly indicate that it is fatty acyl-acyl carrier protein (acyl-ACP). Both this V. harveyi [3H]acylprotein and [3H]palmitoyl-ACP from Escherichia coli were substrates in vitro for either the V. harveyi 32-kDa acyltransferase or the analogous enzyme (34K) from Photobacterium phosphoreum. TLC analysis indicated that the hexane-soluble product of the reaction is fatty acid. No significant cleavage of either E. coli or V. harveyi tetradecanoyl-ACP was observed in extracts of these bacteria unless the 32-kDa or 34K acyltransferase was present. Since these enzymes are believed to be responsible for the supply of fatty acids for reduction to form the aldehyde substrate of luciferase, the above results suggest that long-chain acyl-ACP is the source of fatty acids for bioluminescence

  15. Veronica: Acylated flavone glycosides as chemosystematic markers

    Albach, Dirk C.; Grayer, Renée J.; Kite, Geoffrey C.;

    2005-01-01

    HPLC/DAD and LCeMS of an extract of Veronica spicata subgenus Pseudolysimachium, Plantaginaceae) revealed the presence of six 6-hydroxyluteolin glycosides acylated with phenolic acids, three of which are new compounds and which we called spicosides. A flavonoid survey of seven more species...... instead. Spicosides appeared to be common in subgenus Pseudolysimachium (detected in five out of eight species), but we did not find them in subgenus Pentasepalae. Previously, acetylated 8-hydroxyflavone glycosides have been isolated from or detected in eight species of V. subgenus Pentasepalae (in 13...

  16. Acyl Structure Regulates Galactosylceramide's Interfacial Interactions†

    Ali, Shaukat; Smaby, Janice M.; Brown, Rhoderick E.

    1993-01-01

    Galactosylceramides (GalCer) with homogeneous acyl chains containing zero, one, or two cis double bonds have been synthesized and characterized at an argon-aqueous buffer interface using a Langmuir film balance. Both surface pressure and surface potential were measured as a function of molecular area at 24 °C. N-Lignoceroylgalactosylsphingosine (N-24:0-GalSph), N-stearoylgalactosylsphingosine (N-18:0-GalSph), and N-palmitoylgalactosylsphingosine (N-16:0-GalSph) form condensed films that are s...

  17. Antioxidant Potential of Anthrarobin (1, 2, 10 trihydroxy anthracene) and its Acyl Derivatives

    The current study explores the antioxidant potential of anthrarobin and its synthesized derivatives determined by various methods including DPPH radical scavenging ability, reducing power and superoxide scavenging activity. Anthrarobin was acetylated with acetic anhydride in the presence of pyridine to afford anthracen-1, 10-dihydroxy-2-acetate (1), anthracen-1-hydroxy-2, 10-diacetate (2) and anthracen-1, 2, 10-triacetate (3). Anthrarobin exhibited good antioxidant potential with 68 and 78% at 50 meuM and 100 meuM concentrations, respectively. Reducing power of anthrarobin increases with increase in concentration in a dose-dependent manner as could be seen from 37 and 54% activity at the concentration of 50 and 100 meuM, respectively. 3-Tetra-butyl-4-hydroxyanisole (BHA) used as standard showed 84 and 93% activities at 50 and 100 meuM, respectively. BHA and anthrarobin were compared to determine that how much superoxide radicals were scavenged in alkaline DMSO by different concentrations. It was found that 50 meuM of anthrarobin was needed to scavenge 50% radicals while 12.5 meuM of BHA scavenged 50% radicals in DMSO. It is concluded that anthrarobin has highest antioxidant potential as compared to its derivatives. It is postulated that position and numbers of hydroxyl group in anthrarobin are responsible for antioxidant potential and the activity decreases with the substitution of acyl groups at various positions in synthesized derivatives. (author)

  18. Putative neuroprotective actions of N-acyl-ethanolamines

    Hansen, Harald S.; Moesgaard, B.; Petersen, G.;

    2002-01-01

    N-Acyl-ethanolamines (NAEs) and their precursors, N-acyl-ethanolamine phospholipids (NAPEs), are present in the mammalian brain at levels of a few hundred picomoles/gram tissue and a few nanomoles/gram tissue, respectively. NAE-containing arachidonic acid is called anandamide, and it has attracted...

  19. Understanding Acyl Chain and Glycerolipid Metabolism in Plants

    Ohlrogge, John B.

    2013-11-05

    Progress is reported in these areas: acyl-editing in initial eukaryotic lipid assembly in soybean seeds; identification and characterization of two Arabidopsis thaliana lysophosphatidyl acyltransferases with preference for lysophosphatidylethanolamine; and characterization and subcellular distribution of lysolipid acyl transferase activity of pea leaves.

  20. Oxidative activation of dihydropyridine amides to reactive acyl donors

    Funder, Erik Daa; Trads, Julie Brender; Gothelf, Kurt Vesterager

    2015-01-01

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium...

  1. Erbium trifluoromethanesulfonate-catalyzed Friedel–Crafts acylation using aromatic carboxylic acids as acylating agents under monomode-microwave irradiation

    Tran, Phuong Hoang; Hansen, Poul Erik; Nguyen, Hai Truong;

    2015-01-01

    Erbium trifluoromethanesulfonate is found to be a good catalyst for the Friedel–Crafts acylation of arenes containing electron-donating substituents using aromatic carboxylic acids as the acylating agents under microwave irradiation. An effective, rapid and waste-free method allows the preparation...... of a wide range of aryl ketones in good yields and in short reaction times with minimum amounts of waste...

  2. Acyl-CoA-binding protein (ACBP) can mediate intermembrane acyl-CoA transport and donate acyl-CoA for beta-oxidation and glycerolipid synthesis

    Rasmussen, J T; Færgeman, Nils J.; Kristiansen, K;

    1994-01-01

    , were much lower than expected. ACBP was able to extract hexadecanoyl-CoA from phosphatidylcholine membranes immobilized on a nitrocellulose membrane. The acyl-CoA/ACBP complex formed was able to transport acyl-CoA to mitochondria or microsomes in suspension, or to microsomes immobilized on a...... nitrocellulose membrane, and to donate them to beta-oxidation or glycerolipid synthesis in mitochondria or microsomes, respectively....

  3. Friedel-Craft Acylation of ar-Himachalene: Synthesis of Acyl-ar-Himachalene and a New Acyl-Hydroperoxide

    Abdallah Karim

    2011-07-01

    Full Text Available Friedel-Craft acylation at 100 °C of 2,5,9,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocycloheptene [ar-himachalene (1], a sesquiterpenic hydrocarbon obtained by catalytic dehydrogenation of α-, β- and γ-himachalenes, produces a mixture of two compounds: (3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocyclohepten-2-yl-ethanone (2, in 69% yield, with a conserved reactant backbone, and 3, with a different skeleton, in 21% yield. The crystal structure of 3 reveals it to be 1-(8-ethyl-8-hydroperoxy-3,5,5-trimethyl-5,6,7,8-tetrahydronaphthalen-2-yl-ethanone. In this compound O-H…O bonds form dimers. These hydrogen-bonds, in conjunction with weaker C-H…O interactions, form a more extended supramolecular arrangement in the crystal.

  4. Palladium-Catalyzed Environmentally Benign Acylation.

    Suchand, Basuli; Satyanarayana, Gedu

    2016-08-01

    Recent trends in research have gained an orientation toward developing efficient strategies using innocuous reagents. The earlier reported transition-metal-catalyzed carbonylations involved either toxic carbon monoxide (CO) gas as carbonylating agent or functional-group-assisted ortho sp(2) C-H activation (i.e., ortho acylation) or carbonylation by activation of the carbonyl group (i.e., via the formation of enamines). Contradicting these methods, here we describe an environmentally benign process, [Pd]-catalyzed direct carbonylation starting from simple and commercially available iodo arenes and aldehydes, for the synthesis of a wide variety of ketones. Moreover, this method comprises direct coupling of iodoarenes with aldehydes without activation of the carbonyl and also without directing group assistance. Significantly, the strategy was successfully applied to the synthesis n-butylphthalide and pitofenone. PMID:27377566

  5. Radical prostatectomy - discharge

    ... prostatectomy - discharge; Laparoscopic radical prostatectomy - discharge; LRP - discharge; Robotic-assisted laparoscopic prostatectomy - discharge ; RALP - discharge; Pelvic lymphadenectomy - ...

  6. Free radical inactivation of trypsin

    Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl3COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 200C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl3COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl3COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

  7. Thermodynamics of ligand binding to acyl-coenzyme A binding protein studied by titration calorimetry

    Færgeman, Nils J.; Sigurskjold, B W; Kragelund, B B;

    1996-01-01

    Ligand binding to recombinant bovine acyl-CoA binding protein (ACBP) was examined using isothermal microcalorimetry. Microcalorimetric measurements confirm that the binding affinity of acyl-CoA esters for ACBP is strongly dependent on the length of the acyl chain with a clear preference for acyl-...

  8. Radical theory of rings

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  9. A New Acylated Flavonoid from Anaphalis aureo-punctata

    2003-01-01

    A new acylated tlavonoid glycoside, 3-O-kaempferol-3-O-acetyl-6-O-(P-coumaroyl)-β-D-glucopyranoside 1 was isolated from the whole plant of Anaphalis aureo-punctata. The structure was established by spectral methods.

  10. Regioselective self-acylating cyclodextrins in organic solvent

    Eunae Cho; Deokgyu Yun; Daham Jeong; Jieun Im; Hyunki Kim; Dindulkar, Someshwar D.; Youngjin Choi; Seunho Jung

    2016-01-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrat...

  11. Arabidopsis acyl-acyl carrier protein synthetase AAE15 with medium chain fatty acid specificity is functional in cyanobacteria

    Kaczmarzyk, Danuta; Hudson, Elton P.; Fulda, Martin

    2016-01-01

    Cyanobacteria are potential hosts for the biosynthesis of oleochemical compounds. The metabolic precursors for such compounds are fatty acids and their derivatives, which require chemical activation to become substrates in further conversion steps. We characterized the acyl activating enzyme AAE15 of Arabidopsis encoded by At4g14070, which is a homologue of a cyanobacterial acyl-ACP synthetase (AAS). We expressed AAE15 in insect cells and demonstrated its AAS activity with medium chain fatty ...

  12. Laparoscopic radical cystectomy

    Fergany, Amr

    2012-01-01

    Objective Laparoscopic radical cystectomy (LRC) has emerged as a minimally invasive alternative to open radical cystectomy (ORC). This review focuses on patient selection criteria, technical aspects and postoperative outcomes of LRC. Methods Material for the review was obtained by a PubMed search over the last 10 years, using the keywords ‘laparoscopic radical cystectomy’ and ‘laparoscopic bladder cancer’ in human subjects. Results Twenty-two publications selected for relevance and content we...

  13. Laparoscopic Radical Trachelectomy

    Rendón, Gabriel J.; Ramirez, Pedro T.; Frumovitz, Michael; Schmeler, Kathleen M.; Pareja, Rene

    2012-01-01

    Introduction: The standard treatment for patients with early-stage cervical cancer has been radical hysterectomy. However, for women interested in future fertility, radical trachelectomy is now considered a safe and feasible option. The use of minimally invasive surgical techniques to perform this procedure has recently been reported. Case Description: We report the first case of a laparoscopic radical trachelectomy performed in a developing country. The patient is a nulligravid, 30-y-old fem...

  14. Regioselective Acylation of Diols and Triols: The Cyanide Effect.

    Peng, Peng; Linseis, Michael; Winter, Rainer F; Schmidt, Richard R

    2016-05-11

    Central topics of carbohydrate chemistry embrace structural modifications of carbohydrates and oligosaccharide synthesis. Both require regioselectively protected building blocks that are mainly available via indirect multistep procedures. Hence, direct protection methods targeting a specific hydroxy group are demanded. Dual hydrogen bonding will eventually differentiate between differently positioned hydroxy groups. As cyanide is capable of various kinds of hydrogen bonding and as it is a quite strong sterically nondemanding base, regioselective O-acylations should be possible at low temperatures even at sterically congested positions, thus permitting formation and also isolation of the kinetic product. Indeed, 1,2-cis-diols, having an equatorial and an axial hydroxy group, benzoyl cyanide or acetyl cyanide as an acylating agent, and DMAP as a catalyst yield at -78 °C the thermodynamically unfavorable axial O-acylation product; acyl migration is not observed under these conditions. This phenomenon was substantiated with 3,4-O-unproteced galacto- and fucopyranosides and 2,3-O-unprotected mannopyranosides. Even for 3,4,6-O-unprotected galactopyranosides as triols, axial 4-O-acylation is appreciably faster than O-acylation of the primary 6-hydroxy group. The importance of hydrogen bonding for this unusual regioselectivity could be confirmed by NMR studies and DFT calculations, which indicate favorable hydrogen bonding of cyanide to the most acidic axial hydroxy group supported by hydrogen bonding of the equatorial hydroxy group to the axial oxygen. Thus, the "cyanide effect" is due to dual hydrogen bonding of the axial hydroxy group which enhances the nucleophilicity of the respective oxygen atom, permitting an even faster reaction for diols than for mono-ols. In contrast, fluoride as a counterion favors dual hydrogen bonding to both hydroxy groups leading to equatorial O-acylation. PMID:27104625

  15. Radical Addition to Iminium Ions and Cationic Heterocycles

    Johannes Tauber

    2014-10-01

    Full Text Available Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta reaction, and the Knabe rearrangement will be discussed along with transition metal and photoredox catalysis or electrochemical methods to generate the odd-electron species.

  16. Synthesis of N-acyl-2-amino-2-deoxy-[1-14C]-glucoses as precursors for the biosynthesis of novel N-acyl-neuraminic acids

    N-Propanoyl-, N-butanoyl-, N-pentanoyl-, N-hexanoyl-, N-heptanoyl-, and N-crotonoyl-[1-14]C -D-glucosamine were synthesized from [1-14C]-D-glucosamine and their respective carbonic acid anhydrides as precursors for the biosynthesis of the corresponding N-acyl neuraminic acids. The N-acyl-glucosamines are phosphorylated to their respective phosphate by N-acetyl-glucosamine kinase in a rat liver homogenate. These precursors may become valuable tools to investigate the biological role of the N-acyl side chain of N-acyl-glucosamines and N-acyl neuraminic acids which are components of glycoconjugates. (Author)

  17. Physiology of free radicals

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals imply that every atom, molecule, ion, group of atoms, or molecules with one or several non-paired electrons in outer orbital. Among these are: nitrogenoxide (NO•, superoxide-anion-radical (O2•-, hydroxyl radical (OH•, peroxyl radical (ROO•, alcoxyl radical (RO• and hydroperoxyl radical (HO2•. However, reactive oxygen species also include components without non-paired electrons in outer orbital (so-called reactive non-radical agents, such as: singlet oxygen (1O2, peroxynitrite (ONOO-, hydrogen-peroxide (H2O2, hypochloric acid (eg. HOCl and ozone (O3. High concentrations of free radicals lead to the development of oxidative stress which is a precondition for numerous pathological effects. However, low and moderate concentrations of these matter, which occur quite normally during cell metabolic activity, play multiple significant roles in many reactions. Some of these are: regulation of signal pathways within the cell and between cells, the role of chemoattractors and leukocyte activators, the role in phagocytosis, participation in maintaining, changes in the position and shape of the cell, assisting the cell during adaption and recovery from damage (e.g.caused by physical effort, the role in normal cell growth, programmed cell death (apoptosis and cell ageing, in the synthesis of essential biological compounds and energy production, as well as the contribution to the regulation of the vascular tone, actually, tissue vascularization.

  18. Regioselective self-acylating cyclodextrins in organic solvent

    Cho, Eunae; Yun, Deokgyu; Jeong, Daham; Im, Jieun; Kim, Hyunki; Dindulkar, Someshwar D.; Choi, Youngjin; Jung, Seunho

    2016-03-01

    Amphiphilic cyclodextrins have been synthesized with self-acylating reaction using vinyl esters in dimethylformamide. In the present study no base, catalyst, or enzyme was used, and the structural analyses using thin layer chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry show that the cyclodextrin is substituted preferentially by one acyl moiety at the C2 position of the glucose unit, suggesting that cyclodextrin functions as a regioselective catalytic carbohydrate in organic solvent. In the self-acylation, the most acidic OH group at the 2-position and the inclusion complexing ability of cyclodextrin were considered to be significant. The substrate preference was also observed in favor of the long-chain acyl group, which could be attributed to the inclusion ability of cyclodextrin cavity. Furthermore, using the model amphiphilic building block, 2-O-mono-lauryl β-cyclodextrin, the self-organized supramolecular architecture with nano-vesicular morphology in water was investigated by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. The cavity-type nano-assembled vesicle and the novel synthetic methods for the preparation of mono-acylated cyclodextrin should be of great interest with regard to drug/gene delivery systems, functional surfactants, and carbohydrate derivatization methods.

  19. Trapping of the Enoyl-Acyl Carrier Protein Reductase-Acyl Carrier Protein Interaction.

    Tallorin, Lorillee; Finzel, Kara; Nguyen, Quynh G; Beld, Joris; La Clair, James J; Burkart, Michael D

    2016-03-30

    An ideal target for metabolic engineering, fatty acid biosynthesis remains poorly understood on a molecular level. These carrier protein-dependent pathways require fundamental protein-protein interactions to guide reactivity and processivity, and their control has become one of the major hurdles in successfully adapting these biological machines. Our laboratory has developed methods to prepare acyl carrier proteins (ACPs) loaded with substrate mimetics and cross-linkers to visualize and trap interactions with partner enzymes, and we continue to expand the tools for studying these pathways. We now describe application of the slow-onset, tight-binding inhibitor triclosan to explore the interactions between the type II fatty acid ACP from Escherichia coli, AcpP, and its corresponding enoyl-ACP reductase, FabI. We show that the AcpP-triclosan complex demonstrates nM binding, inhibits in vitro activity, and can be used to isolate FabI in complex proteomes. PMID:26938266

  20. Cholinesterase catalyzed hydrolysis of O-acyl derivatives of serotonin

    Hydrolysis of O acyl serotonin derivatives containing the residues of monocarbon dicarbon and amino acids under the effect of horse serum butyryl cholinesterase and bull erythrocytic acetylcholinesterase has been studied. It has been established, that acetylcholinesterase hydrolizes O acetylserotonin only; butyrylcholinesterase hydrolizes all the compounds investigated, except for 5,5'-terephthaloildioxytriptamine. The kinetic parameters of hydrolysis were determined. O acyl serotonin derivatives turned out good substrates of butylrylcholinesterase; serotonin and 5.5'-terephtaloildioxytriptamine are effective competitine inhibitors of the enzyme. Estimating of resistance of O acyl serotonin derivatines to blood cholinesterase effect under physiological conditions shows that the compounds investigated with the exception of 5,5'-terephthaloildioxytriptamine must be quickly hydrolyzed under butyrylcholinesterase action. 5,5'-terephthaloildioxytriptamine is suggested as a radioprotective preparation with the prolonged effect, which agrees with the biological test results

  1. Ghrelin O-Acyl Transferase: Bridging Ghrelin and Energy Homeostasis

    Andrew Shlimun

    2011-01-01

    Full Text Available Ghrelin O-acyl transferase (GOAT is a recently identified enzyme responsible for the unique n-acyl modification of ghrelin, a multifunctional metabolic hormone. GOAT structure and activity appears to be conserved from fish to man. Since the acyl modification is critical for most of the biological actions of ghrelin, especially metabolic functions, GOAT emerged as a very important molecule of interest. The research on GOAT is on the rise, and several important results reiterating its significance have been reported. Notable among these discoveries are the identification of GOAT tissue expression patterns, effects on insulin secretion, blood glucose levels, feeding, body weight, and metabolism. Several attempts have been made to design and test synthetic compounds that can modulate endogenous GOAT, which could turn beneficial in favorably regulating whole body energy homeostasis. This paper will focus to provide an update on recent advances in GOAT research and its broader implications in the regulation of energy balance.

  2. Caveolar fatty acids and acylation of caveolin-1.

    Qian Cai

    Full Text Available PURPOSE: Caveolae are cholesterol and sphingolipids rich subcellular domains on plasma membrane. Caveolae contain a variety of signaling proteins which provide platforms for signaling transduction. In addition to enriched with cholesterol and sphingolipids, caveolae also contain a variety of fatty acids. It has been well-established that acylation of protein plays a pivotal role in subcellular location including targeting to caveolae. However, the fatty acid compositions of caveolae and the type of acylation of caveolar proteins remain largely unknown. In this study, we investigated the fatty acids in caveolae and caveolin-1 bound fatty acids. METHODS: Caveolae were isolated from Chinese hamster ovary (CHO cells. The caveolar fatty acids were extracted with Folch reagent, methyl esterificated with BF3, and analyzed by gas chromatograph-mass spectrometer (GC/MS. The caveolin-1 bound fatty acids were immunoprecipitated by anti-caveolin-1 IgG and analyzed with GC/MS. RESULTS: In contrast to the whole CHO cell lysate which contained a variety of fatty acids, caveolae mainly contained three types of fatty acids, 0.48 µg palmitic acid, 0.61 µg stearic acid and 0.83 µg oleic acid/caveolae preparation/5 × 10(7 cells. Unexpectedly, GC/MS analysis indicated that caveolin-1 was not acylated by myristic acid; instead, it was acylated by palmitic acid and stearic acid. CONCLUSION: Caveolae contained a special set of fatty acids, highly enriched with saturated fatty acids, and caveolin-1 was acylated by palmitic acid and stearic acid. The unique fatty acid compositions of caveolae and acylation of caveolin-1 may be important for caveolae formation and for maintaining the function of caveolae.

  3. Fluorescently labelled bovine acyl-CoA-binding protein acting as an acyl-CoA sensor: interaction with CoA and acyl-CoA esters and its use in measuring free acyl-CoA esters and non-esterified fatty acids

    Wadum, M.C.; Villadsen, J.K.; Feddersen, S.;

    2002-01-01

    Long-chain acyl-CoA esters are key metabolites in lipid synthesis and b-oxidation but, at the same time, are important regulators of intermediate metabolism, insulin secretion, vesicular trafficking and gene expression. Key tools in studying the regulatory functions of acyl-CoA esters are reliable...... methods for the determination of free acyl-CoA concentrations. No such method is presently available. In the present study, we describe the synthesis of two acyl-CoA sensors for measuring free acyl-CoA concentrations using acyl-CoA-binding protein as a scaffold. Met24 and Ala53 of bovine acyl......-CoA-binding protein were replaced by cysteine residues, which were covalently modified with 6-bromoacetyl-2-dimethylaminonaphthalene to make the two fluorescent acyl-CoA indicators (FACIs) FACI-24 and FACI-53. FACI-24 and FACI-53 showed fluorescence emission maximum at 510 and 525nm respectively, in the absence of...

  4. Radical chemistry of artemisinin

    Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2010-12-29

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  5. Investigation of the kinetics of acyl group exchange Part 3

    Acyl group exchange of substituted phenyl acetates with acetic-1-14C acid catalyzed by pyridine in different solvents was followed kinetically. Structure reactivity relationship and reaction pathway for acyl exchange with acetic acid and acetic anhydride as well as for acetate catalyzed hydrolysis of substituted phenyl acetates are comparatively discussed. The radioactivity was measured by a Tricarb Scintillation Spectrophotometer [Packard Instrument Co]. The IR spectra were recorded on a UR-10 spectrophotometer. Conductrometric and dielectrometric measurements were carried out by using Radelkis equipments. Exchange rates have been calculated from the McKay equation. (F.Gy.)

  6. Funktionelle Analysen zum Acyl-CoA-Bindeprotein (ACBP)

    Klausz, Katja

    2009-01-01

    Das Fettsäurebindeprotein mit der höchsten Spezifität für langkettige, Acyl-CoA ist das Acyl-CoA-Bindeprotein (ACBP). Der Vergleich transgener, ACBP-überexprimierender Ratten mit Wildtypen nach einmonatiger Fütterung einer Niedrig- (LFD) bzw. Hochfettdiät (HFD) zeigt bei den transgenen Tieren höhere Konzentrationen an freien Fettsäuren und Triglyzeriden, sowie veränderte Glukose- und Insulinwerte. Zudem führt die ACBP-Überexpression unter LFD in der Leber zur verringerten SREBP-1c- und L-FABP...

  7. Studies on acylation of lysolecithin in chicken intestine

    The enzymatic acylation of lysolecithin to lecithin is shown to occur in the brush border-free particulate fraction of the small intestines of neonatal chicken. It requires ATP, coenzyme A and Mg2+ or Mn2+ for maximal activity. The system is specific for oleic acid. The fatty acid composition at the α-position of lysolecithin does not seem to influence the rate of acylation. The fatty acid incorporated into lysolecithin is shown to occupy exclusively, the β-position. [32P]lecithin and [1-14C]oleic acid has been used as tracers in the studies. (author)

  8. Lipopolysaccharides with acylation defects potentiate TLR4 signaling and shape T cell responses

    A Martirosyan; Ohne, Y. (Yoichiro); Degos, C. (Clara); Gorvel, L. (Laurent); Moriyon, I; Oh, S.; Gorvel, J P

    2013-01-01

    Lipopolysaccharides or endotoxins are components of Gram-negative enterobacteria that cause septic shock in mammals. However, a LPS carrying hexa-acyl lipid A moieties is highly endotoxic compared to a tetra-acyl LPS and the latter has been considered as an antagonist of hexa-acyl LPS-mediated TLR4 signaling. We investigated the relationship between the structure and the function of bacterial LPS in the context of human and mouse dendritic cell activation. Strikingly, LPS with acylation defec...

  9. Influence of acylation on the adsorption of GLP-2 to hydrophobic surfaces

    Pinholt, Charlotte; Kapp, Sebastian J; Bukrinsky, Jens T; Hostrup, Susanne; Frokjaer, Sven; Norde, Willem; Jorgensen, Lene

    2013-01-01

    Acylation of proteins with a fatty acid chain has proven useful for prolonging the plasma half-lives of proteins. In formulation of acylated protein drugs, knowledge about the effect of acylation with fatty acids on the adsorption behaviour of proteins at interfaces will be valuable. The aim of t...

  10. Radical cystectomy in eldery

    Bančević Vladimir; Aleksić Predrag; Milović Novak; Spasić Aleksandar; Kovačević Božidar; Toševski Perica; Čampara Zoran; Milošević Radovan; Cerović Snežana

    2015-01-01

    Background/Aim. Radical cystectomy is the method of choice for the treatment of muscle invasive bladder cancer. This major surgery is associated with many complications, especially in older patients. The aim of this study was to analyze preoperative comorbidity, and intraoperative and postoperative complicatons in patients older than 75 years. Methods. This clinical, retrospective study included 46 patients over 75 years, who underwent radical cystectomy. I...

  11. A new acylated isoflavone glucoside from Pterocarpus santalinus.

    Krishnaveni, K S; Srinivasa Rao, J V

    2000-09-01

    Phytochemical investigation on the constituents of heartwood of Pterocarpus santalinus resulted in the isolation of a new acylated isoflavone glucoside. The structure of the new compound was elucidated on the basis of spectral studies as 4',5-dihydroxy-7-O-methyl isoflavone 3'-O-D-(3''-E-cinnamoyl)glucoside. PMID:10993243

  12. Enzymatic process for acylation of resveratrol at position 3

    Torres, Pamela; Plou Gasca, Francisco José; Ballesteros Olmo, Antonio

    2008-01-01

    [EN] Enzymatic procedure for the regioselective acylation at position 3 of resveratrol utilising a vinyl ester and specific fungal and bacterial lipases, immobilised, as biocatalyst. The lipases utilised in said procedure come from bacteria or fungi selected from among Alcaligenes, Pseudomonas or Thermomyces.

  13. Medium-chain acyl-CoA dehydrogenase deficiency

    Waddell, Leigh; Wiley, Veronica; Carpenter, Kevin; Bennetts, Bruce; Angel, Lyn; Andresen, Brage S; Wilcken, Bridget

    2006-01-01

    The fatty acid oxidation disorder most commonly identified by tandem mass spectrometry newborn screening is the potentially fatal medium-chain acyl-CoA dehydrogenase deficiency (MCAD). In clinically presenting cases, 80% are homozygous for the common mutation, c.985A > G and 18% heterozygous. We ...

  14. Investigation of the kinetics of acyl group exchange Pt. 6

    Kinetics and mechanism of acyl exchange between 4-nitrophenyl thiolacetate and acetic-1-14C acid or acetic-1-14C anhydride in pyridine and toluene were studied. Comparison of the rate constants and activation parameters to those obtained with 4-nitrophenyl acetate showed a common mechanism for exchange with acetic acid but different pathways for the reaction with acetic anhydride. (author)

  15. Investigation of the kinetics of acyl group exchange Pt. 8

    8-acetoxyquinolines undergo isotopic acyl group exchange with acetic-1-14C acid by the effect of ring nitrogen atom acting as an intramolecular general base catalytic function. Rate constants and activation parameters suggest a reaction mechanism intracomplex in nature. (author)

  16. Investigation of the kinetics of acyl group exchange Pt. 7

    4-nitrophenyl thiol-1-14C acetate exchanges acetyl group with acetyl chloride in nitromethane by the catalytic effect of pyridine. Under the same conditions the ester analogue is unreactive. Kinetic results suggest a common mechanism involving the sulfur atom as reaction site in acyl exchange reactions of thiolester with acetic anhydride and acetyl chloride. (author)

  17. Acyl migration kinetics of vegetable oil 1,2-diacylglycerols

    The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25 to 80 degrees Celsius were examined using proton NMR spectroscopy. The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature...

  18. Fatty Acyl-CoA Reductase 1 Deficiency

    Charles N Swisher

    2015-01-01

    Full Text Available Investigators from Erlangen, Germany; Calgary, CA; and Kafranbel, Syria, identified mutations in the gene, fatty acyl-CoA reductase 1 (FAR1 deficiency, adding to three other genes involved in plasmalogen biosynthesis, in two families affected by severe intellectual disability, early-onset epilepsy, microcephaly, congenital cataracts, growth retardation, and spasticity.

  19. Free Radical Reactions in Food.

    Taub, Irwin A.

    1984-01-01

    Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

  20. Specificity of Acyl-Homoserine Lactone Synthases Examined by Mass Spectrometry

    Gould, Ty A.; Herman, Jake; Krank, Jessica; Robert C. Murphy; Mair E A Churchill

    2006-01-01

    Many gram-negative bacteria produce a specific set of N-acyl-l-homoserine-lactone (AHL) signaling molecules for the purpose of quorum sensing, which is a means of regulating coordinated gene expression in a cell-density-dependent manner. AHLs are produced from acylated acyl-carrier protein (acyl-ACP) and S-adenosyl-l-methionine by the AHL synthase enzyme. The appearance of specific AHLs is due in large part to the intrinsic specificity of the enzyme for subsets of acyl-ACP substrates. Structu...

  1. Fatty acyl-CoA reductases of birds

    Hellenbrand Janine

    2011-12-01

    Full Text Available Abstract Background Birds clean and lubricate their feathers with waxes that are produced in the uropygial gland, a holocrine gland located on their back above the tail. The type and the composition of the secreted wax esters are dependent on the bird species, for instance the wax ester secretion of goose contains branched-chain fatty acids and unbranched fatty alcohols, whereas that of barn owl contains fatty acids and alcohols both of which are branched. Alcohol-forming fatty acyl-CoA reductases (FAR catalyze the reduction of activated acyl groups to fatty alcohols that can be esterified with acyl-CoA thioesters forming wax esters. Results cDNA sequences encoding fatty acyl-CoA reductases were cloned from the uropygial glands of barn owl (Tyto alba, domestic chicken (Gallus gallus domesticus and domestic goose (Anser anser domesticus. Heterologous expression in Saccharomyces cerevisiae showed that they encode membrane associated enzymes which catalyze a NADPH dependent reduction of acyl-CoA thioesters to fatty alcohols. By feeding studies of transgenic yeast cultures and in vitro enzyme assays with membrane fractions of transgenic yeast cells two groups of isozymes with different properties were identified, termed FAR1 and FAR2. The FAR1 group mainly synthesized 1-hexadecanol and accepted substrates in the range between 14 and 18 carbon atoms, whereas the FAR2 group preferred stearoyl-CoA and accepted substrates between 16 and 20 carbon atoms. Expression studies with tissues of domestic chicken indicated that FAR transcripts were not restricted to the uropygial gland. Conclusion The data of our study suggest that the identified and characterized avian FAR isozymes, FAR1 and FAR2, can be involved in wax ester biosynthesis and in other pathways like ether lipid synthesis.

  2. Gangs, Terrorism, and Radicalization

    Scott Decker

    2011-01-01

    Full Text Available What can street gangs tell us about radicalization and extremist groups? At first glance, these two groups seem to push the boundaries of comparison. In this article, we examine the important similarities and differences across criminal, deviant, and extremist groups. Drawing from research on street gangs, this article explores issues such as levels of explanation,organizational structure, group process, and the increasingly important role of technology and the Internet in the context of radicalization. There are points of convergence across these groups, but it is important to understand the differences between these groups. This review finds little evidence to support the contention that American street gangs are becoming increasingly radicalized. This conclusion is based largely on organizational differences between gangs and terror groups.

  3. Sexuality Following Radical Prostatectomy

    Fode, Mikkel; Serefoglu, Ege C; Albersen, Maarten;

    2016-01-01

    INTRODUCTION: Radical prostatectomies can result in urinary incontinence and sexual dysfunction. Traditionally, these issues have been studied separately, and the sexual problem that has received the most focus has been erectile dysfunction. AIM: To summarize the literature on sexually related side...... effects and their consequences after radical prostatectomy and focus on the occurrence and management of problems beyond erectile dysfunction. METHODS: The literature on sexuality after radical prostatectomy was reviewed through a Medline search. Original research using quantitative and qualitative...... methodologies was considered. Priority was given to studies exploring aspects of sexuality other than erectile function. MAIN OUTCOME MEASURES: The prevalence, predictive factors, and management of post-prostatectomy sexual problems beyond erectile dysfunction. RESULTS: Most patients will develop urinary...

  4. HPLC/1H NMR spectroscopic studies of the reactive alpha-1-O-acyl isomer formed during acyl migration of S-naproxen beta-1-O-acyl glucuronide.

    Corcoran, O; Mortensen, R W; Hansen, S H; Troke, J; Nicholson, J K

    2001-10-01

    A widely held view in drug metabolism and pharmacokinetic studies is that the initial 1-isomer to 2-isomer step in the intramolecular acyl migration of drug ester glucuronides is irreversible, and that alpha-1-O-acyl isomers do not occur under physiological conditions. We investigated this hypothesis using high-performance liquid chromatography directly coupled to proton nuclear magnetic resonance spectroscopy (HPLC/1H NMR) and mass spectrometry (LC/MS) to probe the migration reactions of S-naproxen beta-1-O-acyl glucuronide, in phosphate buffer at pH 7.4, 37 degrees C. We report the first direct observation of the alpha-1-O-acyl isomer of a drug ester glucuronide (S-naproxen) formed in a biosystem via the facile acyl migration of the corresponding pure beta-1-O-acyl glucuronide. The unequivocal identification of the reactive product was achieved using stopped-flow one-dimensional HPLC/1H NMR and two-dimensional 1H-1H total correlation spectroscopy (1H-1H TOCSY). Parallel LC/ion-trap mass spectrometry yielded the confirmatory glucuronide masses. Moreover, "dynamic" stopped-flow HPLC/1H NMR experiments revealed transacylation of the isolated alpha-1-O-acyl isomer to a mixture of alpha/beta-2-O-acyl isomers; the reverse reaction from the isolated alpha/beta-2-O-acyl isomers to the alpha-1-O-acyl isomer was also clearly demonstrated. This application of "dynamic" stopped-flow HPLC/1H NMR allows key kinetic data to be obtained on a reactive metabolite that would otherwise be difficult to follow by conventional HPLC and NMR methods where sample preparation and off-line separations are necessary. These data challenge the widely held view that the alpha-1-O-acyl isomers of drug ester glucuronides do not occur under physiological conditions. Furthermore, the similar formation of alpha-1-O-acyl isomers from zomepirac and diflunisal beta-1-O-acyl glucuronides has recently been confirmed (Corcoran et al., unpublished results). Such reactions are also likely to be widespread

  5. Antioxidant and pro-oxidant properties of acylated pelargonidin derivatives extracted from red radish (Raphanus sativus var. niger, Brassicaceae).

    Wang, Lin-Song; Sun, Xiang-Dong; Cao, Ying; Wang, Li; Li, Fang-Jun; Wang, Yi-Fan

    2010-10-01

    The antioxidant and pro-oxidant potential of an extract from red radish, in which the major compounds were acylated pelargonidin derivatives, were assessed with a variety of assays in vitro. The extract appeared to form a complex with Fe(3+) or Cu(2+). It displayed a concentration-dependant reducing power (1.16OD(700 nm) at a concentration of 4mM) and scavenging effect against 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radicals (with IC(50)=1.74 +/- 0.03 mM). It could promote the cleavage of plasmid DNA with Cu(II)/H(2)O(2) or Cu(II) alone. This DNA damage could be inhibited by horseradish peroxidase, catalase, and EDTA, respectively. The extract also showed growth inhibition of Bel-7402 cells at lower concentration. The results suggested that the formation of reactive oxygen species might be involved in the mechanism of DNA damage. The acylated pelargonidin derivatives extracted from red radish could act as antioxidant and pro-oxidant and their antioxidant and pro-oxidant properties were relative to the reaction conditions. It might provide novel antioxidant and anticarcinogenic agents. PMID:20600520

  6. Homegrown religious radicalization

    Khawaja, Iram

    and their families. Existing literature and ways of thinking about the social psychological process of radicalization will be reviewed, such as social identity theory and transformative learning theory, and a theoretical framework based on a focus on belonging, recognition and the sense of community......It has been reported that a growing number of youngsters from Western Europe are engaging in conflicts motivated by religious and political conflicts in the Middle East. This paper aims at exploring the reasons behind this seemingly religious radicalization from the point of view of the youngsters...

  7. Violent Radicalization in Europe

    Dalgaard-Nielsen, Anja

    2010-01-01

    When, why, and how do people living in a democracy become radicalized to the point of being willing to use or directly support the use of terrorist violence against fellow citizens? This question has been at the center of academic and public debate over the past years as terrorist attacks...

  8. Radical School Reform.

    Gross, Beatrice, Ed.; Gross, Ronald, Ed.

    This book provides a comprehensive examination of the nature of the school crisis and the ways in which radical thinkers and educators are dealing with it. Excerpts from the writings of Jonathan Kozol, John Holt, Kenneth Clark, and others are concerned with the realities of education in ghettos and suburbs. Paul Goodman, Marshall McLuhan, Sylvia…

  9. Radically enhanced molecular recognition

    Trabolsi, Ali

    2009-12-17

    The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

  10. On Radical Feminism

    翟良锴

    2015-01-01

    <正>All men are created equal.For centuries,human have been struggling for their rights.Women,as a special social force,are fighting vigorously for their equal rights with men.According to an introduction to feminism,there are three main types of feminism:socialist,reformist and radical(Feminism 101).In order

  11. Radical Financial Innovation

    Robert J. Shiller

    2004-01-01

    Radical financial innovation is the development of new institutions and methods that permit risk management to be extended far beyond its former realm, covering important new classes of risks. This paper compares past such innovation with potential future innovation, looking at the process that produced past success and the possibilities for future financial innovation.

  12. OH radicals in the troposphere

    OH radicals are radicals which determine the photochemistry of the troposphere. The reactivity of OH radicals to organic substances is one of the fundamental criteria for the evaluation of abiotic decomposition. Details are given about the photochemical formation and reaction of OH radicals, the decomposition reactions of organic compounds in the gaseous phase, the determination of the specific rates of OH radical decomposition reactions, measuring methods for the determination of OH radical concentrations in the troposphere, selected results, OH concentration distributions obtained from model calculations, and the influence of trace gases on OH concentrations. A summary, conclusions, and research proposals are attached. (orig./BBR)

  13. Diastereoselective Radical Hydroacylation of Alkylidenemalonates with Aliphatic Aldehydes Initiated by Photolysis of Hypervalent Iodine(III) Reagents.

    Selvakumar, Sermadurai; Sakamoto, Ryu; Maruoka, Keiji

    2016-05-01

    Diastereoselective radical hydroacylation of chiral alkylidenemalonates with aliphatic aldehydes is realized by the combination of a hypervalent iodine(III) reagent and UV-light irradiation. The reaction is initiated by the photolysis of hypervalent iodine(III) reagents under mild, metal-free conditions, and is the first example of diastereoselective addition of acyl radicals to olefins to afford chiral ketones in a highly stereoselective fashion. The obtained optically active ketones are useful chiral synthons, as exemplified by the short formal synthesis of (-)-methyleneolactocin. PMID:27097595

  14. Vectorial acylation in Saccharomyces cerevisiae. Fat1p and fatty acyl-CoA synthetase are interacting components of a fatty acid import complex

    Zou, Zhiying; Tong, Fumin; Færgeman, Nils J.;

    2003-01-01

    In Saccharomyces cerevisiae Fat1p and fatty acyl-CoA synthetase (FACS) are hypothesized to couple import and activation of exogenous fatty acids by a process called vectorial acylation. Molecular genetic and biochemical studies were used to define further the functional and physical interactions ...

  15. Lipase-catalyzed biodiesel synthesis with different acyl acceptors

    Ognjanović Nevena D.

    2008-01-01

    Full Text Available Biodiesel is an alternative fuel for diesel engine that is environmentally acceptable. Conventionally, biodiesel is produced by transesterification of triglycerides and short alcohols in the presence of an acid or an alkaline catalyst. There are several problems associated with this kind of production that can be resolved by using lipase as the biocatalyst. The aim of the present work was to investigate novel acyl acceptors for biodiesel production. 2-Propanol and n-butanol have a less negative effect on lipase stability, and they also improve low temperature properties of the fuel. However, excess alcohol leads to inactivation of the enzyme, and glycerol, a major byproduct, can block the immobilized enzyme, resulting in low enzymatic activity. This problem was solved by using methyl acetate as acyl acceptor. Triacetylglycerol is produced instead of glycerol, and it has no negative effect on the activity of the lipase.

  16. Site-Selective Acylations with Tailor-Made Catalysts.

    Huber, Florian; Kirsch, Stefan F

    2016-04-18

    The acylation of alcohols catalyzed by N,N-dimethylamino pyridine (DMAP) is, despite its widespread use, sometimes confronted with substrate-specific problems: For example, target compounds with multiple hydroxy groups may show insufficient selectivity for one hydroxyl, and the resulting product mixtures are hardly separable. Here we describe a concept that aims at tailor-made catalysts for the site-specific acylation. To this end, we introduce a catalyst library where each entry is constructed by connecting a variable and readily tuned peptide scaffold with a catalytically active unit based on DMAP. For selected examples, we demonstrate how library screening leads to the identification of optimized catalysts, and the substrates of interest can be converted with a markedly enhanced site-selectivity compared with only DMAP. Furthermore, substrate-optimized catalysts of this type can be used to selectively convert "their" substrate in the presence of structurally similar compounds, an important requisite for reactions with mixtures of substances. PMID:26970553

  17. Free radical transfer in polymers

    For the present study of free-radical transfer in polymers pulse radiolysis and product studies have been carried out in aqueous solutions using thus far only the water-soluble polymers polyacrylic acid, polymethacrylic acid and polyvinyl alcohol. When OH radicals, generated in the radiolysis of N2O-saturated aqueous solutions, react with polymers the lifetime of the polymer radical thus created very much depends on the number of radicals per polymer chain. When there are a large number of radicals per chain their bimolecular decay may be faster than the corresponding (diffusion controlled) decay of monomeric radicals, but when the macromolecule contains only few or even just one radical their lifetime is considerably prolonged. Highly charged polymers such as polyacrylic acid at high pH attain a rod-like conformation which again favors a long lifetime of the radicals. Under such conditions, radical transfer reactions can occur. For example, in polyacrylic acid OH radicals generate two kinds of radicals side by side. The radical in β-position to the carboxylate group converts into the thermodynamically more stable α-radicals by an H-transfer reaction as can be followed by spectrophotometry. Besides radical transfer reactions β-fragmentation reactions occur causing chain scission. Such reactions can be followed in a pulse radiolysis experiment by conductometry, because counter ions are released upon chain scission. Such a process is especially effective in the case of polymethacrylic acid, where it results in a chain depolymerization. An intramolecular H-abstraction is also observed in the γ-radiolysis of polyacrylic acid with the corresponding peroxyl radicals. This causes a chain reaction to occur. The resulting hydroperoxides are unstable and decarboxylate given rise to acetylacetone-like products. In polyvinyl alcohol the peroxyl radicals in α-position to the alcohol function undergo HO2-elimination. This prevents a scission of the polymer chain in the

  18. Synthesis and characterization of new amino acyl-4-thiazolidones

    Ana Cristina Lima Leite

    2007-04-01

    Full Text Available A series of heterocyclic compounds with a 4-thiazolidone nucleus and amino acyl moiety were synthesized by protection reaction of thiosemicarbazide using the symmetrical anhydride (Boc2O and cyclization with chloroacetic acid under mild conditions. Trifluoroacetic acid was used to obtain 4-thiazolidone and the alpha-amino acid condensation reactions were carried out using strategies for peptide synthesis. The characterization of this new class of compounds was performed using IR and ¹H-NMR spectroscopy.

  19. Investigation of the kinetics of acyl group exchange Pt. 5

    Kinetics and catalysis mechanism of acyl exchange between 4-nitro-phenyl acetate and acetic-1-C-14 acid catalyzed by pyridine bases (pyridine, 3-methyl, 4-methyl, 4-terc.butyl, 3,4-dimethyl, 3,5-dimethyl pyridine) were studied in several aprotic solvents. Logarithms of rate constants were correlated with pKsub(a)'s of bases in water and in acetonitrile. Bronsted coefficients indicate a general base catalytic action by the above bases. (author)

  20. Investigation of the kinetics of acyl group exchange Part 4

    Kinetics and mechanism of acyl exchange between substituted phenyl acetates and acetic-1-14C anhydride in pyridine solvent were investigated. The excellent Hammett correlation with sigma-sup(*) and Σsigma-sup(*) values for the exchange reaction of 2-nitro- and 2,6-dinitrophenyl acetates, respectively, as well as the similar values for ΔSsup(*) demonstrate the absence of any detectable ortho effect. (author)

  1. The ɛ-Amino Group of Protein Lysine Residues Is Highly Susceptible to Nonenzymatic Acylation by Several Physiological Acyl-CoA Thioesters.

    Simic, Zeljko; Weiwad, Matthias; Schierhorn, Angelika; Steegborn, Clemens; Schutkowski, Mike

    2015-11-01

    Mitochondrial enzymes implicated in the pathophysiology of diabetes, cancer, and metabolic syndrome are highly regulated by acetylation. However, mitochondrial acetyltransferases have not been identified. Here, we show that acetylation and also other acylations are spontaneous processes that depend on pH value, acyl-CoA concentration and the chemical nature of the acyl residue. In the case of a peptide derived from carbamoyl phosphate synthetase 1, the rates of succinylation and glutarylation were up to 150 times than for acetylation. These results were confirmed by using the protein substrate cyclophilin A (CypA). Deacylation experiments revealed that SIRT3 exhibits deacetylase activity but is not able to remove any of the succinyl groups from CypA, whereas SIRT5 is an effective protein desuccinylase. Thus, the acylation landscape on lysine residues might largely depend on the enzymatic activity of specific sirtuins, and the availability and reactivity of acyl-CoA compounds. PMID:26382620

  2. Synthesis and biological activities of turkesterone 11?-acyl derivatives

    Laurence Dinan

    2003-02-01

    Full Text Available Turkesterone is a phytoecdysteroid possessing an 11alpha-hydroxyl group. It is an analogue of the insect steroid hormone 20-hydroxyecdysone. Previous ecdysteroid QSAR and molecular modelling studies predicted that the cavity of the ligand-binding domain of the ecdysteroid receptor would possess space in the vicinity of C-11/C-12 of the ecdysteroid. We report the regioselective synthesis of a series of turkesterone 11alpha-acyl derivatives in order to explore this possibility. The structures of the analogues have been unambiguously determined by spectroscopic means (NMR and low-resolution mass spectrometry. Purity was verified by HPLC. Biological activities have been determined in Drosophila melanogaster BII cell-based bioassay for ecdysteroid agonists and in an in vitro radioligand-displacement assay using bacterially expressed D. melanogaster EcR/USP receptor proteins. The 11alpha-acyl derivatives do retain a significant amount of biological activity relative to the parent ecdysteroid. Further, although activity initially drops with the extension of the acyl chain length (C2 to C4, it then increases (C6 to C10, before decreasing again (C14 and C20. The implications of these findings for the interaction of ecdysteroids with the ecdysteroid receptor and potential applications in the generation of affinity-labelled and fluorescently-tagged ecdysteroids are discussed.

  3. Turnover and metabolism of phosphatidylglycerol acyl moieties in E. coli

    Fatty acids synthesized in mutants (plsB) blocked in de novo phospholipid biosynthesis were preferentially transferred to phosphatidylglycerol (PtdGro). The ratio of phospholipid species labeled with 32P and [3H]acetate in the absence of glycerol-3-P acyltransferase activity indicated that [3H]acetate incorporation into PtdGro was due to fatty acid turnover. The magnitude of the turnover process was difficult to estimate due to a significant contraction of the acetyl-CoA pool following the inhibition of phospholipid synthesis. A possible connection between PtdGro turnover and protein acylation was investigated in an E. coli strain containing a lipoprotein expression vector. Cells were prelabeled with [3H]acetate and lipoprotein expression was induced concomitant with the addition of exogenous [14C]-palmitate. [14C] Palmitate was assimilated into the l-position of phosphatidylethanolamine and transferred to the amino terminus of the lipoprotein. In contrast, the ester-linked lipoprotein fatty acids and PtdGro were not enriched in carbon-14 implying a metabolic relationship between these two pools. The data suggest that turnover of PtdGro acyl moieties is related to protein acylation, but a direct link between the two processes remains to be established

  4. Metabolism of acyl-lipids in Chlamydomonas reinhardtii.

    Li-Beisson, Yonghua; Beisson, Fred; Riekhof, Wayne

    2015-05-01

    Microalgae are emerging platforms for production of a suite of compounds targeting several markets, including food, nutraceuticals, green chemicals, and biofuels. Many of these products, such as biodiesel or polyunsaturated fatty acids (PUFAs), derive from lipid metabolism. A general picture of lipid metabolism in microalgae has been deduced from well characterized pathways of fungi and land plants, but recent advances in molecular and genetic analyses of microalgae have uncovered unique features, pointing out the necessity to study lipid metabolism in microalgae themselves. In the past 10 years, in addition to its traditional role as a model for photosynthetic and flagellar motility processes, Chlamydomonas reinhardtii has emerged as a model organism to study lipid metabolism in green microalgae. Here, after summarizing data on total fatty acid composition, distribution of acyl-lipid classes, and major acyl-lipid molecular species found in C. reinhardtii, we review the current knowledge on the known or putative steps for fatty acid synthesis, glycerolipid desaturation and assembly, membrane lipid turnover, and oil remobilization. A list of characterized or putative enzymes for the major steps of acyl-lipid metabolism in C. reinhardtii is included, and subcellular localizations and phenotypes of associated mutants are discussed. Biogenesis and composition of Chlamydomonas lipid droplets and the potential importance of lipolytic processes in increasing cellular oil content are also highlighted. PMID:25660108

  5. New players in the fatty acyl ethanolamide metabolism.

    Rahman, Iffat Ara Sonia; Tsuboi, Kazuhito; Uyama, Toru; Ueda, Natsuo

    2014-08-01

    Fatty acyl ethanolamides represent a class of endogenous bioactive lipid molecules and are generally referred to as N-acylethanolamines (NAEs). NAEs include palmitoylethanolamide (anti-inflammatory and analgesic substance), oleoylethanolamide (anorexic substance), and anandamide (endocannabinoid). The endogenous levels of NAEs are mainly regulated by enzymes responsible for their biosynthesis and degradation. In mammalian tissues, the major biosynthetic pathway starts from glycerophospholipids and is composed of two enzyme reactions. The first step is N-acylation of ethanolamine phospholipids catalyzed by Ca(2+)-dependent N-acyltransferase and the second step is the release of NAEs from N-acylated ethanolamine phospholipids by N-acylphosphatidylethanolamine (NAPE)-hydrolyzing phospholipase D (NAPE-PLD). As for the degradation of NAEs, fatty acid amide hydrolase plays the central role. However, recent studies strongly suggest the involvement of other enzymes in the NAE metabolism. These enzymes include members of the HRAS-like suppressor family (also called phospholipase A/acyltransferase family), which were originally discovered as tumor suppressors but can function as Ca(2+)-independent NAPE-forming N-acyltransferases; multiple enzymes involved in the NAPE-PLD-independent multi-step pathways to generate NAE from NAPE, which came to light by the analysis of NAPE-PLD-deficient mice; and a lysosomal NAE-hydrolyzing acid amidase as a second NAE hydrolase. These newly recognized enzymes may become the targets for the development of new therapeutic drugs. Here, we focus on recent enzymological findings in this area. PMID:24747663

  6. Cardiolipin molecular species with shorter acyl chains accumulate in Saccharomyces cerevisiae mutants lacking the acyl coenzyme A-binding protein Acb1p: new insights into acyl chain remodeling of cardiolipin.

    Rijken, Pieter J; Houtkooper, Riekelt H; Akbari, Hana; Brouwers, Jos F; Koorengevel, Martijn C; de Kruijff, Ben; Frentzen, Margrit; Vaz, Frédéric M; de Kroon, Anton I P M

    2009-10-01

    The function of the mitochondrial phospholipid cardiolipin (CL) is thought to depend on its acyl chain composition. The present study aims at a better understanding of the way the CL species profile is established in Saccharomyces cerevisiae by using depletion of the acyl-CoA-binding protein Acb1p as a tool to modulate the cellular acyl chain content. Despite the presence of an intact CL remodeling system, acyl chains shorter than 16 carbon atoms (C16) were found to accumulate in CL in cells lacking Acb1p. Further experiments revealed that Taz1p, a key CL remodeling enzyme, was not responsible for the shortening of CL in the absence of Acb1p. This left de novo CL synthesis as the only possible source of acyl chains shorter than C16 in CL. Experiments in which the substrate specificity of the yeast cardiolipin synthase Crd1p and the acyl chain composition of individual short CL species were investigated, indicated that both CL precursors (i.e. phosphatidylglycerol and CDP-diacylglycerol) contribute to comparable extents to the shorter acyl chains in CL in acb1 mutants. Based on the findings, we conclude that the fatty acid composition of mature CL in yeast is governed by the substrate specificity of the CL-specific lipase Cld1p and the fatty acid composition of the Taz1p substrates. PMID:19656950

  7. Exogenous myristic acid can be partially degraded prior to activation to form acyl-acyl carrier protein intermediates and lipid A in Vibrio harveyi.

    Shen, Z; Byers, D M

    1994-01-01

    To study the involvement of acyl carrier protein (ACP) in the metabolism of exogenous fatty acids in Vibrio harveyi, cultures were incubated in minimal medium with [9,10-3H]myristic acid, and labeled proteins were analyzed by gel electrophoresis. Labeled acyl-ACP was positively identified by immunoprecipitation with anti-V. harveyi ACP serum and comigration with acyl-ACP standards and [3H]beta-alanine-labeled bands on both sodium dodecyl sulfate- and urea-polyacrylamide gels. Surprisingly, most of the acyl-ACP label corresponded to fatty acid chain lengths of less than 14 carbons: C14, C12, C10, and C8 represented 33, 40, 14, and 8% of total [3H]14:0-derived acyl-ACPs, respectively, in a dark mutant (M17) of V. harveyi which lacks myristoyl-ACP esterase activity; however, labeled 14:0-ACP was absent in the wild-type strain. 14:0- and 12:0-ACP were also the predominant species labeled in complex medium. In contrast, short-chain acyl-ACPs ( or = C8) labeled with [3H]beta-alanine fivefold, while total incorporation of [3H]14:0 was not affected, although a shift to shorter chain lengths was noted. Additional bands which comigrated with acyl-ACP on sodium dodecyl sulfate gels were identified as lipopolysaccharide by acid hydrolysis and thin-layer chromatography. The levels of incorporation of [3H] 14:0 into acyl-ACP and lipopolysaccharide were 2 and 15%, respectively, of that into phospholipid by 10 min. Our results indicate that in contrast to the situation in Escherichia coli, exogenous fatty acids can be activated to acyl-ACP intermediates after partial degradation in V. harveyi and can effectively label products (i.e., lipid A) that require ACP as an acyl donor. Images PMID:8282714

  8. N-Acyl amino acids and N-acyl neurotransmitter conjugates: neuromodulators and probes for new drug targets

    Connor, Mark; Vaughan, Chris W; Vandenberg, Robert J.

    2010-01-01

    The myriad functions of lipids as signalling molecules is one of the most interesting fields in contemporary pharmacology, with a host of compounds recognized as mediators of communication within and between cells. The N-acyl conjugates of amino acids and neurotransmitters (NAANs) have recently come to prominence because of their potential roles in the nervous system, vasculature and the immune system. NAAN are compounds such as glycine, GABA or dopamine conjugated with long chain fatty acids...

  9. Toward Radicalizing Community Service Learning

    Sheffield, Eric C.

    2015-01-01

    This article advocates a radicalized theoretical construction of community service learning. To accomplish this radicalization, I initially take up a discussion of traditional understandings of CSL rooted in pragmatic/progressive thought. I then suggest that this traditional structural foundation can be radicalized by incorporating Deborah…

  10. Suppression of acyl migration in enzymatic production of structured lipids through temperature programming

    Yang, Tiankui; Fruekilde, Maj-Britt; Xu, Xuebing

    2005-01-01

    considerably inhibited in the temperature-programmed acidolysis of PPP with CLA or CA, with only slight reduction of acyl incorporation, the reaction leading to the required products. Acyl migration was reduced by 29% (35 h) and 45% (48 h), respectively, in the acidolysis of PPP with CLA under solvent and......Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate the...... feasibility of suppressing acyl migration by a programmed change of reaction temperature without loss of reaction yield. The model reactions were the acidolysis of tripalmitin with conjugated linoleic acid (CLA) or with caprylic acid (CA) targeted for human milk fat substitutes. Acyl migration was...

  11. Characterization of new glycolipid biosurfactants, tri-acylated mannosylerythritol lipids, produced by Pseudozyma yeasts.

    Fukuoka, Tokuma; Morita, Tomotake; Konishi, Masaaki; Imura, Tomohiro; Kitamoto, Dai

    2007-07-01

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by Pseudozyma yeasts. They show not only the excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from soybean oil by P. antarctica and P. rugulosa, some new extracellular glycolipids (more hydrophobic than the previously reported di-acylated MELs) were found in the culture medium. The most hydrophobic one was identified as 1-O-alka(e)noyl-4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol, namely tri-acylated MEL. Others were tri-acylated MELs bearing only one acetyl group. The tri-acylated MEL could be prepared by the lipase-catalyzed esterification of a di-acylated MEL with oleic acid implying that the new glycolipids are synthesized from di-acylated MELs in the culture medium containing the residual fatty acids. PMID:17417694

  12. Oligorotaxane Radicals under Orders

    WANG, YUPING; Frasconi, Marco; Liu, Wei-Guang; Sun, Junling; Wu, Yilei; Nassar, Majed S.; Botros, Youssry Y.; Goddard, William A.; Wasielewski, Michael R.; Stoddart, J. Fraser

    2016-01-01

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY2+) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT4+) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations sugge...

  13. Oligorotaxane Radicals under Orders

    WANG, YUPING; Frasconi, Marco; Liu, Wei-Guang; Sun, Junling; Wu, Yilei; Nassar, Majed S.; Botros, Youssry Y.; Goddard, William A.; Wasielewski, Michael R.; Stoddart, J. Fraser

    2016-01-01

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY^(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT^(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations...

  14. Production of structured lipids: acyl migration during enzymatic interesterification and downstream processing

    Xu, Xuebing

    1997-01-01

    -2 position or sn-1,3 positions of glycerol backbone. These kinds of lipids are reported to be promising for both enteral and parenteral nutrition. However, acyl migration occurs in the reaction stage and downstream purification process. This side-reaction causes by-products which are harmful to the...... required products. In this paper, the reasons of acyl migration and factors affecting the acyl migration were reviewed and discussed. The possible solutions were also evaluated....

  15. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride

    Li, Conghu [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China); College of Life Sciences, Anqing Normal University, Anqing 246011 (China); Tian, Zhenhua; Liu, Wentao [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China); Li, Guoying, E-mail: liguoyings@163.com [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China)

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen. - Highlights: • Acylated collagen retained the unique triple helix conformation. • Acylated collagen had stronger thermostability than native collagen. • Amide I was the most sensitive band to the temperature for acylated collagen. • Amide II was the most sensitive band to the temperature for native collagen. • Auto-peak at 1680 cm{sup −1} for acylated collagen disappeared at higher temperature.

  16. Slow Onset Inhibition of Bacterial β-Ketoacyl-acyl Carrier Protein Synthases by Thiolactomycin*

    Machutta, Carl A.; Bommineni, Gopal R.; Luckner, Sylvia R.; Kapilashrami, Kanishk; Ruzsicska, Bela; Simmerling, Carlos; Kisker, Caroline; Tonge, Peter J.

    2009-01-01

    Thiolactomycin (TLM), a natural product thiolactone antibiotic produced by species of Nocardia and Streptomyces, is an inhibitor of the β-ketoacyl-acyl carrier protein synthase (KAS) enzymes in the bacterial fatty acid synthase pathway. Using enzyme kinetics and direct binding studies, TLM has been shown to bind preferentially to the acyl-enzyme intermediates of the KASI and KASII enzymes from Mycobacterium tuberculosis and Escherichia coli. These studies, which utilized acyl-enzyme mimics in...

  17. Rapid Acyl-Homoserine Lactone Quorum Signal Biodegradation in Diverse Soils

    Ya-juan WANG; Leadbetter, Jared Renton

    2005-01-01

    Signal degradation impacts all communications. Although acyl-homoserine lactone (acyl-HSL) quorum-sensing signals are known to be degraded by defined laboratory cultures, little is known about their stability in nature. Here, we show that acyl-HSLs are biodegraded in soils sampled from diverse U.S. sites and by termite hindgut contents. When amended to samples at physiologically relevant concentrations, 14C-labeled acyl-HSLs were mineralized to 14CO2 rapidly and, at most sites examined, witho...

  18. Acyl-Acyl carrier protein regulates transcription of fatty acid biosynthetic genes via the FabT repressor in Streptococcus pneumoniae.

    Jerga, Agoston; Rock, Charles O

    2009-06-01

    Long-chain acyl-acyl carrier proteins (acyl-ACP) are established biochemical regulators of bacterial type II fatty acid synthases due to their ability to feedback-inhibit the early steps in the biosynthetic pathway. In Streptococcus pneumoniae, the expression of the fatty acid synthase (fab) genes is controlled by a helix-turn-helix transcriptional repressor called FabT. A screen of pathway intermediates identified acyl-ACP as a ligand that increased the affinity of FabT for DNA. FabT bound to a wide range of acyl-ACP chain lengths in the absence of DNA, but only the long-chain acyl-ACPs increase the affinity of FabT for DNA. FabT affinity for DNA increased with increasing acyl-ACP chain length with cis-vaccenoyl-ACP being the most effective ligand. Thus, FabT is a new ACP-interacting partner that acts as a transcriptional rheostat to fine tune the expression of the fab genes based on the demand for fatty acids. PMID:19376778

  19. Acyl-Acyl Carrier Protein Regulates Transcription of Fatty Acid Biosynthetic Genes via the FabT Repressor in Streptococcus pneumoniae*

    Jerga, Agoston; Rock, Charles O.

    2009-01-01

    Long-chain acyl-acyl carrier proteins (acyl-ACP) are established biochemical regulators of bacterial type II fatty acid synthases due to their ability to feedback-inhibit the early steps in the biosynthetic pathway. In Streptococcus pneumoniae, the expression of the fatty acid synthase (fab) genes is controlled by a helix-turn-helix transcriptional repressor called FabT. A screen of pathway intermediates identified acyl-ACP as a ligand that increased the affinity of FabT for DNA. FabT bound to a wide range of acyl-ACP chain lengths in the absence of DNA, but only the long-chain acyl-ACPs increase the affinity of FabT for DNA. FabT affinity for DNA increased with increasing acyl-ACP chain length with cis-vaccenoyl-ACP being the most effective ligand. Thus, FabT is a new ACP-interacting partner that acts as a transcriptional rheostat to fine tune the expression of the fab genes based on the demand for fatty acids. PMID:19376778

  20. Cardiolipin Molecular Species with Shorter Acyl Chains Accumulate in Saccharomyces cerevisiae Mutants Lacking the Acyl Coenzyme A-binding Protein Acb1p

    Rijken, Pieter J.; Houtkooper, Riekelt H.; Akbari, Hana; Brouwers, Jos F.; Koorengevel, Martijn C.; de Kruijff, Ben; Frentzen, Margrit; Vaz, Frédéric M.; de Kroon, Anton I. P. M.

    2009-01-01

    The function of the mitochondrial phospholipid cardiolipin (CL) is thought to depend on its acyl chain composition. The present study aims at a better understanding of the way the CL species profile is established in Saccharomyces cerevisiae by using depletion of the acyl-CoA-binding protein Acb1p as a tool to modulate the cellular acyl chain content. Despite the presence of an intact CL remodeling system, acyl chains shorter than 16 carbon atoms (C16) were found to accumulate in CL in cells lacking Acb1p. Further experiments revealed that Taz1p, a key CL remodeling enzyme, was not responsible for the shortening of CL in the absence of Acb1p. This left de novo CL synthesis as the only possible source of acyl chains shorter than C16 in CL. Experiments in which the substrate specificity of the yeast cardiolipin synthase Crd1p and the acyl chain composition of individual short CL species were investigated, indicated that both CL precursors (i.e. phosphatidylglycerol and CDP-diacylglycerol) contribute to comparable extents to the shorter acyl chains in CL in acb1 mutants. Based on the findings, we conclude that the fatty acid composition of mature CL in yeast is governed by the substrate specificity of the CL-specific lipase Cld1p and the fatty acid composition of the Taz1p substrates. PMID:19656950

  1. Plant Cytosolic Acyl-CoA-Binding Proteins.

    Ye, Zi-Wei; Chye, Mee-Len

    2016-01-01

    A gene family encoding six members of acyl-CoA-binding proteins (ACBP) exists in Arabidopsis and they are designated as AtACBP1-AtACBP6. They have been observed to play pivotal roles in plant lipid metabolism, consistent to the abilities of recombinant AtACBP in binding different medium- and long-chain acyl-CoA esters in vitro. While AtACBP1 and AtACBP2 are membrane-associated proteins with ankyrin repeats and AtACBP3 contains a signaling peptide for targeting to the apoplast, AtACBP4, AtACBP5 and AtACBP6 represent the cytosolic forms in the AtACBP family. They were verified to be subcellularly localized in the cytosol using diverse experimental methods, including cell fractionation followed by western blot analysis, immunoelectron microscopy and confocal laser-scanning microscopy using autofluorescence-tagged fusions. AtACBP4 (73.2 kDa) and AtACBP5 (70.1 kDa) are the largest, while AtACBP6 (10.4 kDa) is the smallest. Their binding affinities to oleoyl-CoA esters suggested that they can potentially transfer oleoyl-CoA esters from the plastids to the endoplasmic reticulum, facilitating the subsequent biosynthesis of non-plastidial membrane lipids in Arabidopsis. Recent studies on ACBP, extended from a dicot (Arabidopsis) to a monocot, revealed that six ACBP are also encoded in rice (Oryza sativa). Interestingly, three small rice ACBP (OsACBP1, OsACBP2 and OsACBP3) are present in the cytosol in comparison to one (AtACBP6) in Arabidopsis. In this review, the combinatory and distinct roles of the cytosolic AtACBP are discussed, including their functions in pollen and seed development, light-dependent regulation and substrate affinities to acyl-CoA esters. PMID:26662549

  2. Efficient free fatty acid production in Escherichia coli using plant acyl-ACP thioesterases.

    Zhang, Xiujun; Li, Mai; Agrawal, Arpita; San, Ka-Yiu

    2011-11-01

    Microbial biosynthesis of fatty acid-like chemicals from renewable carbon sources has attracted significant attention in recent years. Free fatty acids can be used as precursors for the production of fuels or chemicals. Free fatty acids can be produced by introducing an acyl-acyl carrier protein thioesterase gene into Escherichia coli. The presence of the acyl-ACP thioesterase will break the fatty acid elongation cycle and release free fatty acid. Depending on their sequence similarity and substrate specificity, class FatA thioesterase is active on unsaturated acyl-ACPs and class FatB prefers saturated acyl group. Different acyl-ACP thioesterases have different degrees of chain length specificity. Although some of these enzymes have been characterized from a number of sources, information on their ability to produce free fatty acid in microbial cells has not been extensively examined until recently. In this study, we examined the effect of the overexpression of acyl-ACP thioesterase genes from Diploknema butyracea, Gossypium hirsutum, Ricinus communis and Jatropha curcas on free fatty acid production. In particular, we are interested in studying the effect of different acyl-ACP thioesterase on the quantities and compositions of free fatty acid produced by an E. coli strain ML103 carrying these constructs. It is shown that the accumulation of free fatty acid depends on the acyl-ACP thioesterase used. The strain carrying the acyl-ACP thioesterase gene from D. butyracea produced approximately 0.2g/L of free fatty acid while the strains carrying the acyl-ACP thioesterase genes from R. communis and J. curcas produced the most free fatty acid at a high level of more than 2.0 g/L at 48 h. These two strains accumulated three major straight chain free fatty acids, C14, C16:1 and C16 at levels about 40%, 35% and 20%, respectively. PMID:22001432

  3. Microbial transglutaminase displays broad acyl-acceptor substrate specificity

    T. Gundersen, Maria; Keillor, Jeffrey W.; Pelletier, Joelle N.

    2013-01-01

    The great importance of amide bonds in industrial synthesis has encouraged the search for efficient catalysts of amide bond formation. Microbial transglutaminase (MTG) is heavily utilized in crosslinking proteins in the food and textile industries, where the side chain of a glutamine reacts with....... Importantly, very small amines carrying either the electron-rich azide or the alkyne groups required for click chemistry were highly reactive as acyl-acceptor substrates, providing a robust route to minimally modified, “clickable” peptides. These results demonstrate that MTG is tolerant to a variety of...

  4. Acylated flavonol glycosides from the flower of Inula britannica.

    Park, E J; Kim, Y; Kim, J

    2000-01-01

    Three new acylated flavonol glycosides, patuletin 7-O-(6' '-isobutyryl)glucoside (1), patuletin 7-O-[6' '-(2-methylbutyryl)]glucoside (2), and patuletin 7-O-(6' '-isovaleryl)glucoside (3), were isolated from the n-BuOH extract of Inula britannica flowers by bioassay-guided fractionation, together with other known flavonoids. The structures were elucidated by 1D and 2D NMR, FABMS, and other spectral analyses. The eight flavonoids, including new compounds (1-3), patulitrin (7), nepitrin (8), axillarin (10), patuletin (11), and luteolin (12), showed profound antioxidant activity in DPPH assay and cytochrome-c reduction assay using HL-60 cell culture system. PMID:10650074

  5. Evolution of the acyl-CoA binding protein (ACBP)

    Burton, Mark; Rose, Timothy M; Faergeman, Nils J;

    2005-01-01

    -CoA pool size, donation of acyl-CoA esters for beta-oxidation, vesicular trafficking, complex lipid synthesis and gene regulation. In the present study, we delineate the evolutionary history of ACBP to get a complete picture of its evolution and distribution among species. ACBP homologues were identified...... duplication and/or retrotransposition events. The ACBP protein is highly conserved across phylums, and the majority of ACBP genes are subjected to strong purifying selection. Experimental evidence indicates that the function of ACBP has been conserved from yeast to humans and that the multiple lineage...

  6. A radical publishing collective: the Journal of Radical Librarianship

    Simon Barron

    2015-01-01

    The Journal of Radical Librarianship is a new open-access journal publishing scholarly work in the field of radical librarianship. The focus on critical approaches to librarianship and anti-marketisation of information is reflected not only in our subject matter but in our publishing model, our licensing model, and our organisational practices. We hope to foster open and engaging discussions about radical approaches to librarianship and information studies.

  7. Oligorotaxane Radicals under Orders.

    Wang, Yuping; Frasconi, Marco; Liu, Wei-Guang; Sun, Junling; Wu, Yilei; Nassar, Majed S; Botros, Youssry Y; Goddard, William A; Wasielewski, Michael R; Stoddart, J Fraser

    2016-02-24

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components-namely oligoviologens-in which different numbers of 4,4'-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY(•+) radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne-azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. PMID:27163033

  8. Bursectomy at radical gastrectomy

    Cuneyt; Kayaalp

    2015-01-01

    Radical gastrectomy with extended lymph node dissec tion and prophylactic resection of the omentum, peri toneum over the posterior lesser sac, pancreas and/o spleen was advocated at the beginning of the 1960 s in Japan. In time, prophylactic routine resections of the pancreas and/or spleen were abandoned because of the high incidence of postoperative complications. However omentectomy and bursectomy continued to be standard parts of traditional radical gastrectomy. The bursaomentalis was thought to be a natural barrier against invasion of cancer cells into the posterior part of the stomach. The theoretical rationale for bursectomy was to reduce the risk of peritoneal recurrences by eliminating the peritoneum over the lesser sac, which might include free cancer cells or micrometastases. Over time, the indication for bursectomy was gradually reduced to only patients with posterior gastric wall tumors penetrating the serosa. Despite its theoretical advantages, its benefit for recurrence or survival has not been proven yet. The possible reasons for this inconsistency are discussed in this review. In conclusion, the value of bursectomy in the treatment of gastric cancer is still under debate and large-scale randomized studies are necessary. Until clear evidence of patient benefit is obtained, its routine use cannot be recommended.

  9. Synthesis of photoactivatable azido-acyl caged oxazine fluorophores for live-cell imaging.

    Anzalone, Andrew V; Chen, Zhixing; Cornish, Virginia W

    2016-07-19

    We report the design and synthesis of a photoactivatable azido-acyl oxazine fluorophore. Photoactivation is achieved cleanly and rapidly with UV light, producing a single fluorescent oxazine photoproduct. We demonstrate the utility of azido-acyl caged oxazines for protein specific labeling in living mammalian cells using the TMP-tag technology. PMID:27377037

  10. 1,5-Anhydro-D-fructose: regioselective acylation with fatty acids

    Lundt, Inge; Andersen, Søren Møller; Marcussen, Jan; Yu, Shukun

    Regioselective acylation of 1,5-anhydro-D-fructose was performed with dodecanoic acid to give 1,5-anhydro-6-O-dodecanoyl-D-fructose, chemically in 50% yield and enzymatically in quantitative yield. Quantitative conversions were also obtained using hexadecanoic and octadecanoic acids as acyl donors...

  11. Influence of Lipid A Acylation Pattern on Membrane Permeability and Innate Immune Stimulation

    Robert K. Ernst

    2013-08-01

    Full Text Available Lipid A, the hydrophobic anchor of lipopolysaccharide (LPS, is an essential component in the outer membrane of Gram-negative bacteria. It can stimulate the innate immune system via Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD2, leading to the release of inflammatory cytokines. In this study, six Escherichia coli strains which can produce lipid A with different acylation patterns were constructed; the influence of lipid A acylation pattern on the membrane permeability and innate immune stimulation has been systematically investigated. The lipid A species were isolated and identified by matrix assisted laser ionization desorption-time of flight/tandem mass spectrometry. N-Phenyl naphthylamine uptake assay and antibiotic susceptibility test showed that membrane permeability of these strains were different. The lower the number of acyl chains in lipid A, the stronger the membrane permeability. LPS purified from these strains were used to stimulate human or mouse macrophage cells, and different levels of cytokines were induced. Compared with wild type hexa-acylated LPS, penta-acylated, tetra-acylated and tri-acylated LPS induced lower levels of cytokines. These results suggest that the lipid A acylation pattern influences both the bacterial membrane permeability and innate immune stimulation. The results would be useful for redesigning the bacterial membrane structure and for developing lipid A vaccine adjuvant.

  12. Acyl-CoA binding proteins; structural and functional conservation over 2000 MYA

    Faergeman, Nils J; Wadum, Majken; Feddersen, Søren;

    2007-01-01

    -CoA binding protein, ACBP, has been proposed to play a pivotal role in the intracellular trafficking and utilization of long-chain fatty acyl-CoA esters. Depletion of acyl-CoA binding protein in yeast results in aberrant organelle morphology incl. fragmented vacuoles, multi-layered plasma membranes and...

  13. A Stereoelectronic Basis for the Kinetic Resolution of N-Heterocycles with Chiral Acylating Reagents

    Hsieh, Sheng-Ying; Wanner, Benedikt; Wheeler, Philip; Beauchemin, André M.; Rovis, Tomislav; Bode, Jeffrey W.

    2014-01-01

    The kinetic resolution of N-heterocycles with chiral acylating agents reveals a previously unrecognized stereoelectronic effect in amine acylation. Combined with a new achiral hydroxamate, this effect makes possible the resolution of various N-heterocycles using easily prepared reagents. A transition state model to rationalize the stereochemical outcome of this kinetic resolution is also proposed.

  14. Reaction of Glyconitriles with Organometallic Reagents: Access to Acyl β-C-Glycosides.

    Guisot, Nicolas E S; Ella Obame, Idriss; Ireddy, Prathap; Nourry, Arnaud; Saluzzo, Christine; Dujardin, Gilles; Dubreuil, Didier; Pipelier, Muriel; Guillarme, Stéphane

    2016-03-18

    A new strategy for the synthesis of acyl β-C-glycosides is described. The reactivity of glyconitriles toward organometallic reagents such as organomagnesium or organolithium derivatives was studied, affording acyl β-C-glycosides in moderate to good yields. In this study, glycal formation was efficiently prevented by deprotonating the hydroxyl group in position 2 of the glyconitriles during the process. PMID:26926714

  15. Suppression of acyl migration in enzymatic production of structured lipids through temperature programming

    Yang, Tiankui; Fruekilde, Maj-Britt; Xu, Xuebing

    2005-01-01

    Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate the feasi......Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate...... the feasibility of suppressing acyl migration by a programmed change of reaction temperature without loss of reaction yield. The model reactions were the acidolysis of tripalmitin with conjugated linoleic acid (CLA) or with caprylic acid (CA) targeted for human milk fat substitutes. Acyl migration...... was considerably inhibited in the temperature-programmed acidolysis of PPP with CLA or CA, with only slight reduction of acyl incorporation, the reaction leading to the required products. Acyl migration was reduced by 29% (35 h) and 45% (48 h), respectively, in the acidolysis of PPP with CLA under solvent...

  16. Acylation of aromatic alcohols and phenols over InCl3/montmorillonite K-10 catalysts

    Vasant R Choudhary; Kailash Y Patil; Suman K Jana

    2004-03-01

    Montmorillonite K-10 clay supported InCl3 is a highly active catalyst for the acylation of aromatic alcohols and phenols with different acyl chlorides. This catalyst can be reused in reactions a number of times without very significant loss of catalytic activity.

  17. Accumulation of N-acyl-ethanolamine phospholipids in rat brains during post-decapitative ischemia

    Moesgaard, B.; Hansen, Harald S.; Jaroszewski, J.W.

    1999-01-01

    Phosphorus-31 nuclear magnetic resonance (P NMR) spectroscopy has been used to study accumulation of N-acyl-ethanolamine phospholipids in rat brains during post-decapitative ischemia. Lipids were extracted from rat brain homogenates and the extracts were thoroughly washed with aq. potassium...... NMR spectra at 0.18 and 0.22 ppm (relative to the chemical shift of 1,2-diacyl-sn-glycero-3-phosphocholine (PCD(DIACYL)) at -0.84 ppm). These signals were identified as originating from 1,2-diacyl- sn-glycero-3-phospho-(N-acyl)-ethanolamine (NAPED(DIACYL)) and 1-(1'- alkenyl)-2-acyl-sn-glycero-3......-phospho(N-acyl)-ethanolamine (NAPE(PLAS)), respectively, by spiking with authentic materials. Additionally, the identification was verified by thin-layer chromatography, which also showed the accumulation of N-acyl-ethanolamine phospholipids. The use of K-EDTA instead of the commonly used Cs-EDTA in the...

  18. Acylation of salmon calcitonin modulates in vitro intestinal peptide flux through membrane permeability enhancement

    Trier, Sofie; Linderoth, Lars; Bjerregaard, Simon;

    2015-01-01

    Acylation of peptide drugs with fatty acid chains has proven beneficial for prolonging systemic circulation, as well as increasing enzymatic stability and interactions with lipid cell membranes. Thus, acylation offers several potential benefits for oral delivery of therapeutic peptides, and we...... its influence on intestinal cell translocation and membrane interaction. We find that acylation drastically increases in vitro intestinal peptide flux and confers a transient permeability enhancing effect on the cell layer. The analogues permeabilize model lipid membranes, indicating that the effect...... is due to a solubilization of the cell membrane, similar to transcellular oral permeation enhancers. The effect is dependent on pH, with larger effect at lower pH, and is impacted by acylation chain length and position. Compared to the unacylated peptide backbone, N-terminal acylation with a short...

  19. Suzuki-Miyaura Cross-Coupling in Acylation Reactions, Scope and Recent Developments

    Annamaria Deagostino

    2013-01-01

    Full Text Available Since the first report and due to its handiness and wide scope, the Suzuki-Miyaura (SM cross coupling reaction has become a routine methodology in many laboratories worldwide. With respect to other common transition metal catalyzed cross couplings, the SM reaction has been so far less exploited as a tool to introduce an acyl function into a specific substrate. In this review, the various approaches found in the literature will be considered, starting from the direct SM acylative coupling to the recent developments of cross coupling between boronates and acyl chlorides or anhydrides. Special attention will be dedicated to the use of masked acyl boronates, alkoxy styryl and alkoxy dienyl boronates as coupling partners. A final section will be then focused on the acyl SM reaction as key synthetic step in the framework of natural products synthesis.

  20. Relationships between acylated ghrelin with growth hormone, insulin resistance, lipid profile, and cardio respiratory function in lean and obese men

    Hasan Matin Homaee

    2011-01-01

    Conclusions: Obese and lean inactive young men had different levels of acylated ghrelin, GH, insulin, insulin resistance index, cardiorespiratory function and body fat percent. Body fat percent, insulin, and GH levels appear to be best determinant factors of acylated ghrelin levels. Also, in both obese and lean young men, higher levels of cardiovascular function were associated with higher levels of acylated ghrelin.

  1. Substantial species differences in relation to formation and degradation of N-acyl-ethanolamine phospholipids in heart tissue

    Moesgaard, B.; Petersen, G.; Hansen, Harald S.;

    2002-01-01

    The formation of N-acyl-ethanolamines (NAEs), including the cannabinoid receptor ligand anandamide, and their precursors N-acyl-ethanolamine phospholipids (NAPEs) are catalyzed by NAPE-hydrolyzing phospholipase D (NAPE-PLD) and N-acyl-transferase, respectively. NAPE and NAE are suggested to have...

  2. Radical cystectomy in eldery

    Bančević Vladimir

    2015-01-01

    Full Text Available Background/Aim. Radical cystectomy is the method of choice for the treatment of muscle invasive bladder cancer. This major surgery is associated with many complications, especially in older patients. The aim of this study was to analyze preoperative comorbidity, and intraoperative and postoperative complicatons in patients older than 75 years. Methods. This clinical, retrospective study included 46 patients over 75 years, who underwent radical cystectomy. Indications for surgery, and complications during and after the surgery were followed up. Results. Preoperatively, anemia caused by hematuria was registered in 76% of the patients. In 52% of the patients urine derivation was performed by ileal conduit, in 35% by ureterocutaneostomy and in 13% orthotopic ileal neobladder was created. The average duration of surgery was 190 (120-300 min. A total of 76% of the patients were treated by blood supstitution intraoperatively, average 630 (310-1230 mL. Concerning pathological stage of transitional cell carcinoma of urinary bladder, 26% of the patients had T2, 4% T3a, 52% T3b, and 14% T4a stage. In one case, planocellular carcinoma was diagnosed by patohistological examination, and in 2 cases prostate carcinoma was incidentally found. The average duration of hospitalization was 16 (8-35 days. Conclusion. The main reason for cystectomy in patients over 70 and 80 years was gross hematuria caused by bladder cancer, with consecutive anemia which could not be solved using endoscopic treatment or blood supstitution. As expected, a prolonged stay in hospital after cystectomy, and a higher rate of complications were recorded in this population.

  3. Toxicity of Carboxylic Acid-Containing Drugs: The Role of Acyl Migration and CoA Conjugation Investigated.

    Lassila, Toni; Hokkanen, Juho; Aatsinki, Sanna-Mari; Mattila, Sampo; Turpeinen, Miia; Tolonen, Ari

    2015-12-21

    Many carboxylic acid-containing drugs are associated with idiosyncratic drug toxicity (IDT), which may be caused by reactive acyl glucuronide metabolites. The rate of acyl migration has been earlier suggested as a predictor of acyl glucuronide reactivity. Additionally, acyl Coenzyme A (CoA) conjugates are known to be reactive. Here, 13 drugs with a carboxylic acid moiety were incubated with human liver microsomes to produce acyl glucuronide conjugates for the determination of acyl glucuronide half-lives by acyl migration and with HepaRG cells to monitor the formation of acyl CoA conjugates, their further conjugate metabolites, and trans-acylation products with glutathione. Additionally, in vitro cytotoxicity and mitochondrial toxicity experiments were performed with HepaRG cells to compare the predictability of toxicity. Clearly, longer acyl glucuronide half-lives were observed for safe drugs compared to drugs that can cause IDT. Correlation between half-lives and toxicity classification increased when "relative half-lives," taking into account the formation of isomeric AG-forms due to acyl migration and eliminating the effect of hydrolysis, were used instead of plain disappearance of the initial 1-O-β-AG-form. Correlation was improved further when a daily dose of the drug was taken into account. CoA and related conjugates were detected primarily for the drugs that have the capability to cause IDT, although some exceptions to this were observed. Cytotoxicity and mitochondrial toxicity did not correlate to drug safety. On the basis of the results, the short relative half-life of the acyl glucuronide (high acyl migration rate), high daily dose and detection of acyl CoA conjugates, or further metabolites derived from acyl CoA together seem to indicate that carboxylic acid-containing drugs have a higher probability to cause drug-induced liver injury (DILI). PMID:26558897

  4. Studies of radiation-produced radicals and radical ions

    The radiolytic oxidation of anti-5-methylbicyclo[2.1.0]pentane gives the 1-methylcyclopentene radical cation as the sole rearrangement product H migration whereas oxidation of its syn isomer results in the highly selective formation of the 3-methylcyclopentene radical cation by methyl group migration. Since exactly the same stereoselectivity of olefin formation was observed in corresponding PET (photosensitized electron transfer) studies in the liquid phase, it is concluded that the rearrangement in this case also occurs through the intermediacy of radical cations. Clearly, the radical cation rearrangement must occur very rapidly (10-8--10-9s) under liquid-phase conditions at room temperature to compete with back electron transfer, and therefore the hydrogen (or methyl) migration is a fast process under these conditions. An intramolecular cycloaddition reaction was demonstrated in the radical cation rearrangement of 4-vinylcyclohexene to bicyclo[3.2.1]oct-2-ene. ESR studies show that the radiolytic oxidation of quadricyclane in Freon matrices under conditions of high substrate dilution leads to the bicyclo[3.2.0]hepta-2,6-diene radical cation as well as the previously reported norbornadiene radical cation, the former species predominating at sufficiently low concentrations

  5. Preparation and Characterization of O-Acylated Fucosylated Chondroitin Sulfate from Sea Cucumber

    Na Gao

    2012-08-01

    Full Text Available Fucosylated chondroitin sulfate (FuCS, a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS was chosen to prepare its derivates by selective substitution at OH groups. Its O-acylation was carried out in a homogeneous way using carboxylic acid anhydrides. The structures of O-acylated derivatives were characterized by NMR. The results indicated that the 4-O-sulfated fucose residues may be easier to be acylated than the other ones in the sulfated fucose branches. But the O-acylation was always accompanied by the β-elimination, and the degree of elimination was higher as that of acylation was higher. The results of clotting assay indicated that the effect of partial O-acylation of the dFuCS on their anticoagulant potency was not significant and the O-acylation of 2-OH groups of 4-O-sulfated fucose units did not affect the anticoagulant activity.

  6. Acyl-Homoserine Lactone Quorum Sensing in the Roseobacter Clade

    Jindong Zan

    2014-01-01

    Full Text Available Members of the Roseobacter clade are ecologically important and numerically abundant in coastal environments and can associate with marine invertebrates and nutrient-rich marine snow or organic particles, on which quorum sensing (QS may play an important role. In this review, we summarize current research progress on roseobacterial acyl-homoserine lactone-based QS, particularly focusing on three relatively well-studied representatives, Phaeobacter inhibens DSM17395, the marine sponge symbiont Ruegeria sp. KLH11 and the dinoflagellate symbiont Dinoroseobacter shibae. Bioinformatic survey of luxI homologues revealed that over 80% of available roseobacterial genomes encode at least one luxI homologue, reflecting the significance of QS controlled regulatory pathways in adapting to the relevant marine environments. We also discuss several areas that warrant further investigation, including studies on the ecological role of these diverse QS pathways in natural environments.

  7. Small Antimicrobial Agents Based on Acylated Reduced Amide Scaffold.

    Teng, Peng; Huo, Da; Nimmagadda, Alekhya; Wu, Jianfeng; She, Fengyu; Su, Ma; Lin, Xiaoyang; Yan, Jiyu; Cao, Annie; Xi, Chuanwu; Hu, Yong; Cai, Jianfeng

    2016-09-01

    Prevalence of drug-resistant bacteria has emerged to be one of the greatest threats in the 21st century. Herein, we report the development of a series of small molecular antibacterial agents that are based on the acylated reduced amide scaffold. These molecules display good potency against a panel of multidrug-resistant Gram-positive and Gram-negative bacterial strains. Meanwhile, they also effectively inhibit the biofilm formation. Mechanistic studies suggest that these compounds kill bacteria by compromising bacterial membranes, a mechanism analogous to that of host-defense peptides (HDPs). The mechanism is further supported by the fact that the lead compounds do not induce resistance in MRSA bacteria even after 14 passages. Lastly, we also demonstrate that these molecules have therapeutic potential by preventing inflammation caused by MRSA induced pneumonia in a rat model. This class of compounds could lead to an appealing class of antibiotic agents combating drug-resistant bacterial strains. PMID:27526720

  8. Mellemkaedet acyl-CoA dehydrogenase (MCAD)-mangel

    Gregersen, N; Winter, V; Andresen, B S;

    1992-01-01

    today considered more common than previously anticipated, since the incidence of patients with MCAD enzyme deficiency in Denmark is estimated to 1/27,000 newborns, or two new cases annually. The relationship between the enzyme defect (gene defect) and the clinical expression of the disease is a main......Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially fatal metabolic disease, which is characterized by non-ketotic hypoglycemia and lethargy. The disease manifests itself by periodic attacks in connection with infections and periods of fasting, or suddenly as unexpected child......-card constitute today a certain and specific diagnosis for the disease in 75% of all cases. In the remaining 25% the mutation analysis is supplemented with urine metabolite studies by gas chromatography/mass spectrometry, and with measurements of enzyme activities in cultured skin fibroblasts. The disease is...

  9. Synthesis of acyl derivatives of salicin, salirepin, and arbutin.

    Stepanova, Elena V; Belyanin, Maxim L; Filimonov, Victor D

    2014-03-31

    The total synthesis of two natural phenolglycosides of the family Salicaceae, namely: populoside and 2-(β-d-glucopyranosyloxy)-5-hydroxy benzyl (3-methoxy-4-hydroxy) cinnamoate and nine not found yet in plants acyl derivatives of phenoglycosides: 2-(β-d-glucopyranosyloxy)-benzylcinnamoate, 2-(β-d-glucopyranosyloxy)-benzyl (4-hydroxy) benzoate, 2-(β-d-glucopyranosyloxy)-benzyl (3-methoxy-4-hydroxy) benzoate, 2-(β-d-glucopyranosyloxy)-5-hydroxy benzyl (3,4-dihydroxy) cinnamoate, 2-(β-d-glucopyranosyloxy)-5-hydroxy benzylcinnamoate, 2-(β-d-glucopyranosyloxy)-5-hydroxy benzyl (4-hydroxy) benzoate, 2-(β-d-glucopyranosyloxy)-5-hydroxy benzyl (3-methoxy-4-hydroxy) benzoate, 2-(β-d-glucopyranosyloxy)-5-benzoyloxy benzylbenzoate and 4-(β-d-glucopyranosyloxy)-phenylbenzoate, starting from readily available phenols and glucose was developed for the first time. PMID:24632218

  10. An acylated phloroglucinol with antimicrobial properties from Helichrysum caespititium.

    Mathekga, A D; Meyer, J J; Horn, M M; Drewes, S E

    2000-01-01

    A new acylated form of a phloroglucinol with significant antimicrobial properties was isolated by bioactivity guided fractionation from Helichrysum caespititium (Asteraceae). The structure elucidation, and conformation of the new phloroglucinol, 2-methyl-4-[2',4',6'-trihydroxy-3'-(2-methylpropanoyl) phenyl]but-2-enyl acetate, was established by high field NMR spectroscopic and MS data. The compound inhibited growth of Bacillus cereus, B. pumilus, B. subtilis and Micrococcus kristinae at the very low concentration of 0.5 microg/ml and Staphylococcus aureus at 5.0 microg/ml. Six fungi tested were similarly inhibited at low MICs, Aspergillus flavus and A. niger (1.0 microg/ml), Cladosporium chladosporioides (5 microg/ml), C. cucumerinum and C. sphaerospermum (0.5 microg/ml) and Phylophthora capsici at 1.0 microg/ml. PMID:10656414

  11. Acyl-Carbon Bond Cleaving Cytochrome P450 Enzymes: CYP17A1, CYP19A1 and CYP51A1.

    Akhtar, Muhammad; Wright, J Neville

    2015-01-01

    Cytochrome P450 (P450 or CYP) enzymes in their resting state contain the heme-iron in a high-spin FeIII state. Binding of a substrate to a P450 enzyme allows transfer of the first electron, producing a Fe(II) species that reacts with oxygen to generate a low-spin iron superoxide intermediate (FeIII-O-O•) ready to accept the second electron to produce an iron peroxy anion intermediate (a, FeIII-O-O-). In classical monooxygenation reactions, the peroxy anion upon protonation fragments to form the reactive Compound I intermediate (Por•+FeIV=O), or its ferryl radical resonance form (FeIV-O•). However, when the substrate projects a carbonyl functionality, of the type b, at the active site as is the case for reactions catalyzed by CYP17A1, CYP19A1 and CYP51A1, the peroxy anion (FeIII-O-O-) is trapped, yielding a tetrahedral intermediate (c) that fragments to an acyl-carbon cleavage product (d plus an acid). Analogous acyl-carbon cleavage reactions are also catalyzed by certain hepatic P450s and CYP125A1 from Mycobacterium tuberculosis. A further improvisation on the theme is provided by aldehyde deformylases that convert long-chain aliphatic aldehydes to hydrocarbons. CYP17A1 is involved in the biosynthesis of corticoids as well as androgens. The flux toward these two classes of hormones seems to be regulated by cytochrome b 5, at the level of the acyl-carbon cleavage reaction. It is this regulation of CYP17A1 that provides a safety mechanism, ensuring that during corticoid biosynthesis, which requires 17α-hydroxylation by CYP17A1, androgen formation is avoided (Fig. 4.1). PMID:26002733

  12. Interfacial Behavior of Fatty-Acylated Sericin Prepared by Lipase-Catalyzed Solid-Phase Synthesis

    Ogino, Masato; Tanaka, Rie; 服部, 誠; Yoshida, Tadashi; 横手, よし子; 高橋, 幸資

    2006-01-01

    Fatty-acylated sericin {1:0.7 molar ratio of sericin (Mr 18,700) to oleic acid} was prepared by lipase-catalyzed solid-phase synthesis in n-hexane containing oleic acid to endow sericin with interfacial properties. Acylation with oleic acid was confirmed by 1H-NMR. The fatty-acylated sericin exhibited superior emulsifying activity index and emulsion stability in the presence of 0?0.5 M NaCl, in a temperature range of 30?80 °C and pH range of 2?7, as compared with the control sericin. The fatt...

  13. Radical production in biological systems

    This paper describes our effort to develop a metric for radiation exposure that is more fundamental than adsorbed dose and upon which a metric for exposure to chemicals could be based. This metric is based on the production of radicals by the two agents. Radicals produced by radiation in biological systems commonly assumed to be the same as those produced in water despite the presence of a variety of complex molecules. This may explain why the extensive efforts to describe the relationship between energy deposition (track structure) and molecular damage to DNA, based on the spectrum of radicals produced, have not been successful in explaining simple biological effects such as cell killing. Current models assume that DNA and its basic elements are immersed in water-like media and only model the production and diffusion of water-based radicals and their interaction with DNA structures; these models lack the cross sections associated with each macro-component of DNA and only treat water-based radicals. It has been found that such models are not realistic because DNA is not immersed in pure water. A computer code capable of simulating electron tracks, low-energy electrons, energy deposition in small molecules, and radical production and diffusion in water like media has been developed. This code is still in at a primitive stage and development is continuing. It is being used to study radical production by radiation, and radical diffusion and interactions in simple molecular systems following their production. We are extending the code to radical production by chemicals to complement our PBPK modeling efforts. It therefore has been developed primarily for use with radionuclides that are in biological materials, and not for radiation fields

  14. Guest Editorial: Processes of Radicalization and De-Radicalization

    Donatella Della Porta

    2012-05-01

    Full Text Available The study of radicalization and de-radicalization, understood as processes leading towards the increased or decreased use of political violence, is central to the question of how political violence emerges, how it can be prevented, and how it can be contained. The focus section of this issue of the International Journal of Conflict and Violence addresses radicalization and de-radicalization, seeking to develop a more comprehensive understanding of the processes, dynamics, and mechanisms involved and taking an interdisciplinary approach to overcome the fragmentation into separate disciplines and focus areas. Contributions by Pénélope Larzillière, Felix Heiduk, Bill Kissane, Hank Johnston, Christian Davenport and Cyanne Loyle, Veronique Dudouet, and Lasse Lindekilde address repressive settings, legitimacy, institutional aspects, organizational outcomes, and dynamics in Europe, Asia, Africa, and North and South America.

  15. Redox Properties of Free Radicals.

    Neta, P.

    1981-01-01

    Describes pulse radiolysis as a useful means in studing one-electron redox potentials. This method allows the production of radicals and the determination of their concentration and rates of reaction. (CS)

  16. Radical polymerization of monoethyl itaconate

    Katsikas Lynne; Nišević Nataša; Ignjatović Milka; Adamović Vladimir; Đakov Tatjana A.; Popović Ivanka G.

    2003-01-01

    The radical polymerization of monoethyl itaconate (MEI) was investigated in bulk and in solution at 60°C using a,a'-azobisisobutyronitrile as initiator. It was established that the obtained polymer poly(monoethyl itaconate) was insoluble in its monomer, implying that the bulk polymerization of MEI was a precipitation polymerization. The polymerization kinetics of MEI were discussed and compared to the polymerization kinetics of structurally similar alkyl itaconates. The homogeneous radical po...

  17. Ecoporn, Irrationalities and Radical Environmentalism

    Măntescu, Liviu

    2016-01-01

    This study explores the ‘irrationalities’ of deep ecology activism in the context of radical environmentalism by using the empirical example of ecoporn. Fuck For Forest is an environmental Non-Governmental Organisation which undertakes fund-raising for re-forestation and forest protection by means of pornography. Following twelve months of ethnographic fieldwork, this study presents first research results on a radical environmental project which does not promote democratic and established pro...

  18. Long-chain acyl-homoserine lactones from Methylobacterium mesophilicum: synthesis and absolute configuration.

    Pomini, Armando M; Cruz, Pedro L R; Gai, Cláudia; Araújo, Welington L; Marsaioli, Anita J

    2009-12-01

    The acyl-homoserine lactones (acyl-HSLs) produced by Methylobacterium mesophilicum isolated from orange trees infected with the citrus variegated chlorosis (CVC) disease have been studied, revealing the occurrence of six long-chain acyl-HSLs, i.e., the saturated homologues (S)-N-dodecanoyl (1) and (S)-N-tetradecanoyl-HSL (5), the uncommon odd-chain N-tridecanoyl-HSL (3), the new natural product (S)-N-(2E)-dodecenoyl-HSL (2), and the rare unsaturated homologues (S)-N-(7Z)-tetradecenoyl (4) and (S)-N-(2E,7Z)-tetradecadienyl-HSL (6). The absolute configurations of all HSLs were determined as 3S. Compounds 2 and 6 were synthesized for the first time. Antimicrobial assays with synthetic acyl-HSLs against Gram-positive bacterial endophytes co-isolated with M. mesophilicum from CVC-infected trees revealed low or no antibacterial activity. PMID:19919062

  19. Ring-opening metathesis polymerization-based recyclable magnetic acylation reagents.

    Kainz, Quirin M; Linhardt, Roland; Maity, Pradip K; Hanson, Paul R; Reiser, Oliver

    2013-04-01

    An operationally simple method for the acylation of amines utilizing carbon-coated metal nanoparticles as recyclable supports is reported. Highly magnetic carbon-coated cobalt (Co/C) and iron (Fe/C) nanobeads were functionalized with a norbornene tag (Nb-tag) through a "click" reaction followed by surface activation employing Grubbs-II catalyst and subsequent grafting of acylated N-hydroxysuccinimide ROMPgels (ROMP=ring-opening metathesis polymerization). The high loading (up to 2.6 mmolg(-1) ) hybrid material was applied in the acylation of various primary and secondary amines. The products were isolated in high yields (86-99%) and excellent purities (all >95 % by NMR spectroscopy) after rapid magnetic decantation and simple evaporation of the solvents. The spent resins were successfully re-acylated by acid chlorides, anhydrides, and carboxylic acids and reused for up to five consecutive cycles without considerable loss of activity. PMID:23427021

  20. Eradication of Helicobacter pylori increases childhood growth and serum acylated ghrelin levels

    Yang, Yao-Jong; Sheu, Bor-Shyang; Yang, Hsiao-Bai; Lu, Cheng-Chan; Chuang, Ching-Chun

    2012-01-01

    AIM: To determine whether Helicobacter pylori (H. pylori)-infected children have reduced body weight (BW) and height (BH) growth, and if H. pylori eradication may restore growth while improving serum acylated ghrelin.

  1. Selective Acylation Enhances Membrane Charge Sensitivity of the Antimicrobial Peptide Mastoparan-X

    Etzerodt, Thomas Povl; Henriksen, Jonas Rosager; Rasmussen, Palle;

    2011-01-01

    The partitioning of the wasp venom peptide mastoparan-X (MPX) into neutral and negatively charged lipid membranes has been compared with two new synthetic analogs of MPX where the Nα-terminal of MPX was acylated with propanoic acid (PA) and octanoic acid (OA). The acylation caused a considerable...... change in the membrane partitioning properties of MPX and it was found that the shorter acylation with PA gave improved affinity and selectivity toward negatively charged membranes, whereas OA decreased the selectivity. Based on these findings, we hypothesize that minor differences in the embedding and...... positioning of the peptide in the membrane caused by either PA or OA acylation play a critical role in the fine-tuning of the effective charge of the peptide and thereby the fine-tuning of the peptide's selectivity between neutral and negatively charged lipid membranes. This finding is unique compared to...

  2. Specificity of acyl-homoserine lactone synthases examined by mass spectrometry.

    Gould, Ty A; Herman, Jake; Krank, Jessica; Murphy, Robert C; Churchill, Mair E A

    2006-01-01

    Many gram-negative bacteria produce a specific set of N-acyl-L-homoserine-lactone (AHL) signaling molecules for the purpose of quorum sensing, which is a means of regulating coordinated gene expression in a cell-density-dependent manner. AHLs are produced from acylated acyl-carrier protein (acyl-ACP) and S-adenosyl-L-methionine by the AHL synthase enzyme. The appearance of specific AHLs is due in large part to the intrinsic specificity of the enzyme for subsets of acyl-ACP substrates. Structural studies of the Pantoea stewartii enzyme EsaI and AHL-sensitive bioassays revealed that threonine 140 in the acyl chain binding pocket directs the enzyme toward production of 3-oxo-homoserine lactones. Mass spectrometry was used to examine the range of AHL molecular species produced by AHL synthases under a variety of conditions. An AHL selective normal-phase chromatographic purification with addition of a deuterated AHL internal standard was followed by reverse-phase liquid chromatography-tandem mass spectrometry in order to obtain estimates of the relative amounts of different AHLs from biological samples. The AHLs produced by wild-type and engineered EsaI and LasI AHL synthases show that intrinsic specificity and different cellular conditions influence the production of AHLs. The threonine at position 140 in EsaI is important for the preference for 3-oxo-acyl-ACPs, but the role of the equivalent threonine in LasI is less clear. In addition, LasI expressed in Escherichia coli produces a high proportion of unusual AHLs with acyl chains consisting of an odd number of carbons. Furthermore, these studies offer additional methods that will be useful for surveying and quantitating AHLs from different sources. PMID:16385066

  3. LuxR homolog-independent gene regulation by acyl-homoserine lactones in Pseudomonas aeruginosa.

    Chugani, Sudha; Greenberg, Everett Peter

    2010-06-01

    Pseudomonas aeruginosa quorum control of gene expression involves three LuxR-type signal receptors LasR, RhlR, and QscR that respond to the LasI- and RhlI-generated acyl-homoserine lactone (acyl-HSL) signals 3OC12-HSL and C4-HSL. We found that a LasR-RhlR-QscR triple mutant responds to acyl-HSLs by regulating at least 37 genes. LuxR homolog-independent activation of the representative genes antA and catB also occurs in the wild type. Expression of antA was influenced the most by C10-HSL and to a lesser extent by other acyl-HSLs, including the P. aeruginosa 3OC12-HSL and C4-HSL signals. The ant and cat operons encode enzymes for the degradation of anthranilate to tricarboxylic acid cycle intermediates. Our results indicate that LuxR homolog-independent acyl-HSL control of the ant and cat operons occurs via regulation of antR, which codes for the transcriptional activator of the ant operon. Although P. aeruginosa has multiple pathways for anthranilate synthesis, one pathway-the kynurenine pathway for tryptophan degradation-is required for acyl-HSL activation of the ant operon. The kynurenine pathway is also the critical source of anthranilate for energy metabolism via the antABC gene products, as well as the source of anthranilate for synthesis of the P. aeruginosa quinolone signal. Our discovery of LuxR homolog-independent responses to acyl-HSLs provides insight into acyl-HSL signaling. PMID:20498077

  4. Pharmacokinetics of naproxen, its metabolite O-desmethylnaproxen, and their acyl glucuronides in humans.

    Vree, T B; van den Biggelaar-Martea, M; Verwey-van Wissen, C P; Vree, J B; Guelen, P J

    1993-08-01

    The aim of this investigation was to assess the pharmacokinetics of naproxen in 10 human subjects after an oral dose of 500 mg using a direct HPLC analysis of the acyl glucuronide conjugates of naproxen and its metabolite O-desmethylnaproxen. The mean t1/2 of naproxen in 9 subjects was 24.7 +/- 6.4 h (range 16 to 36 h). The t1/2 of 7.4 as found in subject number 10 must, therefore, be regarded as an extraordinary case (p < 0.0153). Naproxen acyl glucuronide accounts for 50.8 +/- 7.32 per cent of the dose, its isomerized conjugate isoglucuronide for 6.5 +/- 2.0 per cent, O-desmethylnaproxen acyl glucuronide for 14.3 +/- 3.4 per cent, and its isoglucuronide for 5.5 +/- 1.3 per cent (n = 10; 100 h collection period). Naproxen and O-desmethylnaproxen are excreted in negligible amounts (< 1 per cent). Even though urine pH of the subjects was kept acid (range pH 5.0-5.5) in order to stabilize the acyl glucuronides, isomerization takes place in blood when the acyl glucuronide is released from the liver for excretion by the kidney. Binding to plasma proteins was measured as 98 per cent and 100 per cent, respectively for the unconjugated compounds naproxen and O-desmethylnaproxen. Binding of the acyl glucuronides was less, being 92 per cent; for naproxen acyl glucuronide, 66 per cent for naproxen isoglucuronide, 72 per cent for O-desmethylnaproxen acyl glucuronide and 42 per cent for O-desmethylnaproxen isoglucuronide. PMID:8218967

  5. Inhibition of DNA–Topoisomerase I by Acylated Triterpene Saponins from Pittosporum angustifolium Lodd.

    Baecker, C; Drwal, M.N.; Preissner, R; Lindequist, U.

    2016-01-01

    Abstract Previous phytochemical investigation of the leaves and seeds of Pittosporum angustifolium Lodd. led to the isolation and structural elucidation of polyphenols and triterpene saponins. Evaluation for cytotoxicity of isolated saponins revealed that the predominant structural feature for a cytotoxic activity are acyl substituents at the oleanane aglycon backbone. The present work reports the results of a screening of 10 selected acylated saponins for their potential to inhibit the human...

  6. Preparation and Characterization of O-Acylated Fucosylated Chondroitin Sulfate from Sea Cucumber

    Na Gao; Mingyi Wu; Shao Liu; Wu Lian; Zi Li; Jinhua Zhao

    2012-01-01

    Fucosylated chondroitin sulfate (FuCS), a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS) was chosen to prepare its derivates by selective substitution at OH groups. Its O-acylation was carried out in a homogeneous way using carboxylic acid anhydrides. The structures of O-acylated derivatives were characterize...

  7. Very long chain acyl-coenzyme A dehydrogenase deficiency with adult onset

    Smelt, A H; Poorthuis, B J; Onkenhout, W; Scholte, H R; Andresen, B S; van Duinen, S G; Gregersen, N; Wintzen, A R

    1998-01-01

    Very long chain acyl-coenzyme A (acyl-CoA) dehydrogenase (VLCAD) deficiency is a severe disorder of mitochondrial beta-oxidation in infants. We report adult onset of attacks of painful rhabdomyolysis. Gas chromatography identified strongly elevated levels of tetradecenoic acid, 14:1(n-9), tetrade...... be due to residual enzyme activity as a consequence of the two missense mutations. Treatment with L-carnitine and medium chain triglycerides in the diet did not reduce the attacks of rhabdomyolysis....

  8. Acyl Meldrum's acid derivatives: application in organic synthesis

    This review is focused on an important class of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleophiles. The possible mechanisms of these transformations are analyzed. The bibliography includes 134 references

  9. The Acute Effects of Swimming on Appetite, Food Intake, and Plasma Acylated Ghrelin

    Stensel, David J.; Wasse, Lucy K.; King, James A

    2011-01-01

    Swimming may stimulate appetite and food intake but empirical data are lacking. This study examined appetite, food intake, and plasma acylated ghrelin responses to swimming. Fourteen healthy males completed a swimming trial and a control trial in a random order. Sixty min after breakfast participants swam for 60 min and then rested for six hours. Participants rested throughout the control trial. During trials appetite was measured at 30 min intervals and acylated ghrelin was assessed periodic...

  10. Deciphering the acylation pattern of Yersinia enterocolitica lipid A.

    Mar Reinés

    Full Text Available Pathogenic bacteria may modify their surface to evade the host innate immune response. Yersinia enterocolitica modulates its lipopolysaccharide (LPS lipid A structure, and the key regulatory signal is temperature. At 21°C, lipid A is hexa-acylated and may be modified with aminoarabinose or palmitate. At 37°C, Y. enterocolitica expresses a tetra-acylated lipid A consistent with the 3'-O-deacylation of the molecule. In this work, by combining genetic and mass spectrometric analysis, we establish that Y. enterocolitica encodes a lipid A deacylase, LpxR, responsible for the lipid A structure observed at 37°C. Western blot analyses indicate that LpxR exhibits latency at 21°C, deacylation of lipid A is not observed despite the expression of LpxR in the membrane. Aminoarabinose-modified lipid A is involved in the latency. 3-D modelling, docking and site-directed mutagenesis experiments showed that LpxR D31 reduces the active site cavity volume so that aminoarabinose containing Kdo(2-lipid A cannot be accommodated and, therefore, not deacylated. Our data revealed that the expression of lpxR is negatively controlled by RovA and PhoPQ which are necessary for the lipid A modification with aminoarabinose. Next, we investigated the role of lipid A structural plasticity conferred by LpxR on the expression/function of Y. enterocolitica virulence factors. We present evidence that motility and invasion of eukaryotic cells were reduced in the lpxR mutant grown at 21°C. Mechanistically, our data revealed that the expressions of flhDC and rovA, regulators controlling the flagellar regulon and invasin respectively, were down-regulated in the mutant. In contrast, the levels of the virulence plasmid (pYV-encoded virulence factors Yops and YadA were not affected in the lpxR mutant. Finally, we establish that the low inflammatory response associated to Y. enterocolitica infections is the sum of the anti-inflammatory action exerted by pYV-encoded YopP and the

  11. Effects of ghrelin and des-acyl ghrelin on neurogenesis of the rat fetal spinal cord

    Expressions of the growth hormone secretagogue receptor (GHS-R) mRNA and its protein were confirmed in rat fetal spinal cord tissues by RT-PCR and immunohistochemistry. In vitro, over 3 nM ghrelin and des-acyl ghrelin induced significant proliferation of primary cultured cells from the fetal spinal cord. The proliferating cells were then double-stained using antibodies against the neuronal precursor marker, nestin, and the cell proliferation marker, 5-bromo-2'-deoxyuridine (BrdU), and the nestin-positive cells were also found to be co-stained with antibody against GHS-R. Furthermore, binding studies using [125I]des-acyl ghrelin indicated the presence of a specific binding site for des-acyl ghrelin, and confirmed that the binding was displaced with unlabeled des-acyl ghrelin or ghrelin. These results indicate that ghrelin and des-acyl ghrelin induce proliferation of neuronal precursor cells that is both dependent and independent of GHS-R, suggesting that both ghrelin and des-acyl ghrelin are involved in neurogenesis of the fetal spinal cord

  12. Lipopolysaccharides with acylation defects potentiate TLR4 signaling and shape T cell responses.

    Martirosyan, Anna; Ohne, Yoichiro; Degos, Clara; Gorvel, Laurent; Moriyón, Ignacio; Oh, Sangkon; Gorvel, Jean-Pierre

    2013-01-01

    Lipopolysaccharides or endotoxins are components of Gram-negative enterobacteria that cause septic shock in mammals. However, a LPS carrying hexa-acyl lipid A moieties is highly endotoxic compared to a tetra-acyl LPS and the latter has been considered as an antagonist of hexa-acyl LPS-mediated TLR4 signaling. We investigated the relationship between the structure and the function of bacterial LPS in the context of human and mouse dendritic cell activation. Strikingly, LPS with acylation defects were capable of triggering a strong and early TLR4-dependent DC activation, which in turn led to the activation of the proteasome machinery dampening the pro-inflammatory cytokine secretion. Upon activation with tetra-acyl LPS both mouse and human dendritic cells triggered CD4(+) T and CD8(+) T cell responses and, importantly, human myeloid dendritic cells favored the induction of regulatory T cells. Altogether, our data suggest that LPS acylation controlled by pathogenic bacteria might be an important strategy to subvert adaptive immunity. PMID:23390517

  13. The games radicals play : special issue on free radicals and radical ions

    Walton, John C; Ffrancon Williams

    2015-01-01

    Chemistry and Physics have aptly been described as “most excellent children of Intellect and Art” [1]. Both these “children” engage with many playthings, and molecules rank as one of their first favorites, especially radicals, which are amongst the most lively and exciting. Checking out radicals dancing to the music of entropy round their potential energy ballrooms is surely both entertaining and enlightening. Radicals’ old favorite convolutions are noteworthy, but the new styles, modes and a...

  14. Crystalline bipyridinium radical complexes and uses thereof

    Fahrenbach, Albert C.; Barnes, Jonathan C.; Li, Hao; Stoddart, J. Fraser; Basuray, Ashish Neil; Sampath, Srinivasan

    2015-09-01

    Described herein are methods of generating 4,4'-bipyridinium radical cations (BIPY.sup..cndot.+), and methods for utilizing the radical-radical interactions between two or more BIPY.sup..cndot.+ radical cations that ensue for the creation of novel materials for applications in nanotechnology. Synthetic methodologies, crystallographic engineering techniques, methods of physical characterization, and end uses are described.

  15. Crystalline bipyridinium radical complexes and uses thereof

    Fahrenbach, Albert C.; Barnes, Jonathan C.; Li, Hao; Stoddart, J. Fraser; Basuray, Ashish Neil; Sampath, Srinivasan

    2015-09-01

    Described herein are methods of generating 4,4'-bipyridinium radical cations (BIPY.sup..cndot.+), and methods for utilizing the radical-radical interactions between two or more BIPY.sup..cndot.+ radical cations that ensue for the creation of novel materials for applications in nanotechnology. Synthetic methodologies, crystallographic engineering techniques, methods of physical characterization, and end uses are described.

  16. Endogenous N-acyl taurines regulate skin wound healing.

    Sasso, Oscar; Pontis, Silvia; Armirotti, Andrea; Cardinali, Giorgia; Kovacs, Daniela; Migliore, Marco; Summa, Maria; Moreno-Sanz, Guillermo; Picardo, Mauro; Piomelli, Daniele

    2016-07-26

    The intracellular serine amidase, fatty acid amide hydrolase (FAAH), degrades a heterogeneous family of lipid-derived bioactive molecules that include amides of long-chain fatty acids with taurine [N-acyl-taurines (NATs)]. The physiological functions of the NATs are unknown. Here we show that genetic or pharmacological disruption of FAAH activity accelerates skin wound healing in mice and stimulates motogenesis of human keratinocytes and differentiation of human fibroblasts in primary cultures. Using untargeted and targeted lipidomics strategies, we identify two long-chain saturated NATs-N-tetracosanoyl-taurine [NAT(24:0)] and N-eicosanoyl-taurine [NAT(20:0)]-as primary substrates for FAAH in mouse skin, and show that the levels of these substances sharply decrease at the margins of a freshly inflicted wound to increase again as healing begins. Additionally, we demonstrate that local administration of synthetic NATs accelerates wound closure in mice and stimulates repair-associated responses in primary cultures of human keratinocytes and fibroblasts, through a mechanism that involves tyrosine phosphorylation of the epidermal growth factor receptor and an increase in intracellular calcium levels, under the permissive control of transient receptor potential vanilloid-1 receptors. The results point to FAAH-regulated NAT signaling as an unprecedented lipid-based mechanism of wound-healing control in mammalian skin, which might be targeted for chronic wound therapy. PMID:27412859

  17. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    M. D. Andrés-Hernández

    2010-11-01

    Full Text Available Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE and total peroxy radicals (RO2* = HO2+ΣRO2, R = organic chain by two similar instruments based on the peroxy radical chemical amplification (PeRCA technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously.

    Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  18. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    M. D. Andrés-Hernández

    2010-04-01

    Full Text Available Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE and total peroxy radicals (RO2*=HO2+ΣRO2, R= organic chain by two similar instruments based on the peroxy radical chemical amplification (PerCA technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously.

    Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  19. Standard Electrode Potentials Involving Radicals in Aqueous Solution: Inorganic Radicals

    Armstrong, David A.; Huie, Robert E.; Koppenol, Willem H.; Lymar, Sergei V.; Merenyi, Gabor; Neta, Pedatsur; Ruscic, Branko; Stanbury, David M.; Steenken, Steen; Wardman, Peter

    2015-12-01

    Recommendations are made for standard potentials involving select inorganic radicals in aqueous solution at 25 °C. These recommendations are based on a critical and thorough literature review and also by performing derivations from various literature reports. The recommended data are summarized in tables of standard potentials, Gibbs energies of formation, radical pKa’s, and hemicolligation equilibrium constants. In all cases, current best estimates of the uncertainties are provided. An extensive set of Data Sheets is appended that provide original literature references, summarize the experimental results, and describe the decisions and procedures leading to each of the recommendations

  20. Radical-Enhanced Chinese Character Embedding

    Sun, Yaming; Lin, Lei; Tang, Duyu; Yang, Nan; Ji, Zhenzhou; Wang, Xiaolong

    2014-01-01

    We present a method to leverage radical for learning Chinese character embedding. Radical is a semantic and phonetic component of Chinese character. It plays an important role as characters with the same radical usually have similar semantic meaning and grammatical usage. However, existing Chinese processing algorithms typically regard word or character as the basic unit but ignore the crucial radical information. In this paper, we fill this gap by leveraging radical for learning continuous r...

  1. Effect of heterologous expression of acyl-CoA-binding protein on acyl-CoA level and composition in yeast

    Mandrup, S; Jepsen, R; Skøtt, H; Rosendal, J; Højrup, P; Kristiansen, K; Knudsen, J

    1993-01-01

    We have expressed a bovine synthetic acyl-CoA-binding protein (ACBP) gene in yeast (Saccharomyces cerevisiae) under the control of the GAL1 promoter. The heterologously expressed bovine ACBP constituted up to 6.4% of total cellular protein and the processing was identical with that of native bovi...

  2. Investigation of the kinetics of acyl group exchange Pt. 8. Intramolecular general base catalysis of isotopic acyl exchange between 8-acetoquinolines and acetic-1-/sup 14/C acid

    Dutka, F.; Marton, A.F. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1982-11-03

    8-acetoxyquinolines undergo isotopic acyl group exchange with acetic-1-/sup 14/C acid by the effect of ring nitrogen atom acting as an intramolecular general base catalytic function. Rate constants and activation parameters suggest a reaction mechanism intracomplex in nature.

  3. Removal of the acyl donor residue allows the use of simple alkyl esters as acyl donors for the dynamic kinetic resolution of secondary alcohols

    Verzijl, Gerard K.M.; Vries, Johannes G. de; Broxterman, Quirinus B.

    2005-01-01

    The dynamic kinetic resolution of secondary alcohols using a lipase and a ruthenium catalyst required some improvements to make it suitable for its use in an industrial process. The use of p-chlorophenyl acetate as acyl donor is not desirable in view of the toxicity of the side product. We herein re

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

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

    2016-01-01

    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. PMID:26899032

  5. Evolution of acyl-ACP-thioesterases and β-ketoacyl-ACP-synthases revealed by protein-protein interactions

    Beld, Joris; Jillian L Blatti; Behnke, Craig; Mendez, Michael; Burkart, Michael D.

    2013-01-01

    The fatty acid synthase (FAS) is a conserved primary metabolic enzyme complex capable of tolerating cross-species engineering of domains for the development of modified and overproduced fatty acids. In eukaryotes, acyl-acyl carrier protein thioesterases (TEs) off-load mature cargo from the acyl carrier protein (ACP), and plants have developed TEs for short/medium-chain fatty acids. We showed that engineering plant TEs into the green microalga Chlamydomonas reinhardtii does not result in the p...

  6. Acyl-ACP thioesterases from Camelina sativa: Cloning, enzymatic characterization and implication in seed oil fatty acid composition.

    Rodríguez-Rodríguez, Manuel Fernando; Salas, Joaquín J.; Garcés Mancheño, Rafael; Martínez-Force, Enrique

    2014-01-01

    Acyl-acyl carrier protein (ACP) thioesterases are intraplastidial enzymes that terminate de novo fatty acid biosynthesis in the plastids of higher plants by hydrolyzing the thioester bond between ACP and the fatty acid synthesized. Free fatty acids are then esterified with coenzyme A prior to being incorporated into the glycerolipids synthesized through the eukaryotic pathway. Acyl-ACP thioesterases belong to the TE14 family of thioester-active enzymes and can be classified as FatAs and FatBs...

  7. Rapid acyl-homoserine lactone quorum signal biodegradation in diverse soils.

    Wang, Ya-Juan; Leadbetter, Jared Renton

    2005-03-01

    Signal degradation impacts all communications. Although acyl-homoserine lactone (acyl-HSL) quorum-sensing signals are known to be degraded by defined laboratory cultures, little is known about their stability in nature. Here, we show that acyl-HSLs are biodegraded in soils sampled from diverse U.S. sites and by termite hindgut contents. When amended to samples at physiologically relevant concentrations, 14C-labeled acyl-HSLs were mineralized to 14CO2 rapidly and, at most sites examined, without lag. A lag-free turf soil activity was characterized in further detail. Heating or irradiation of the soil prior to the addition of radiolabel abolished mineralization, whereas protein synthesis inhibitors did not. Mineralization exhibited an apparent Km of 1.5 microM acyl-HSL, ca. 1,000-fold lower than that reported for a purified acyl-HSL lactonase. Under optimal conditions, acyl-HSL degradation proceeded at a rate of 13.4 nmol x h(-1) x g of fresh weight soil(-1). Bioassays established that the final extent of signal inactivation was greater than for its full conversion to CO2 but that the two processes were well coupled kinetically. A most probable number of 4.6 x 10(5) cells . g of turf soil(-1) degraded physiologically relevant amounts of hexanoyl-[1-14C]HSL to 14CO2. It would take chemical lactonolysis months to match the level of signal decay achieved in days by the observed biological activity. Rapid decay might serve either to quiet signal cross talk that might otherwise occur between spatially separated microbial aggregates or as a full system reset. Depending on the context, biological signal decay might either promote or complicate cellular communications and the accuracy of population density-based controls on gene expression in species-rich ecosystems. PMID:15746331

  8. Protective actions of des-acylated ghrelin on brain injury and blood-brain barrier disruption after stroke in mice.

    Ku, Jacqueline M; Taher, Mohammadali; Chin, Kai Yee; Barsby, Tom; Austin, Victoria; Wong, Connie H Y; Andrews, Zane B; Spencer, Sarah J; Miller, Alyson A

    2016-09-01

    The major ghrelin forms, acylated ghrelin and des-acylated ghrelin, are novel gastrointestinal hormones. Moreover, emerging evidence indicates that these peptides may have other functions including neuro- and vaso-protection. Here, we investigated whether post-stroke treatment with acylated ghrelin or des-acylated ghrelin could improve functional and histological endpoints of stroke outcome in mice after transient middle cerebral artery occlusion (tMCAo). We found that des-acylated ghrelin (1 mg/kg) improved neurological and functional performance, reduced infarct and swelling, and decreased apoptosis. In addition, it reduced blood-brain barrier (BBB) disruption in vivo and attenuated the hyper-permeability of mouse cerebral microvascular endothelial cells after oxygen glucose deprivation and reoxygenation (OGD + RO). By contrast, acylated ghrelin (1 mg/kg or 5 mg/kg) had no significant effect on these endpoints of stroke outcome. Next we found that des-acylated ghrelin's vasoprotective actions were associated with increased expression of tight junction proteins (occludin and claudin-5), and decreased cell death. Moreover, it attenuated superoxide production, Nox activity and expression of 3-nitrotyrosine. Collectively, these results demonstrate that post-stroke treatment with des-acylated ghrelin, but not acylated ghrelin, protects against ischaemia/reperfusion-induced brain injury and swelling, and BBB disruption, by reducing oxidative and/or nitrosative damage. PMID:27303049

  9. Laparoscopic radical and partial cystectomy

    Challacombe Ben

    2005-01-01

    Full Text Available Radical cystectomy remains the standard treatment for muscle invasive organ confined bladder carcinoma. Laparoscopic radical cystoprostatectomy (LRC is an advanced laparoscopic procedure that places significant demands on the patient and the surgeon alike. It is a prolonged procedure which includes several technical steps and requires highly developed laparoscopic skills including intra-corporeal suturing. Here we review the development of the technique, the indications, complications and outcomes. We also examine the potential benefits of robotic-assisted LRC and explore the indications and technique of laparoscopic partial cystectomy.

  10. Radical democratic politics and feminism

    Martínez Labrin, Soledad

    2006-05-01

    Full Text Available In the article I present a reflection around the radical democratic project proposed by Chantal Mouffe and Ernesto Laclau. Specifically, I examine the application of the project in the context of the “new social movements” and especially, of feminist movement. I state the need of drawing attention to universalism and essentialism as the main obstacles to generate a collective proposal without margins. Nevertheless, doubts remind about the possibility of building up a feminism tailored by the radical democratic project, in a stage in which the political action of such a movement is characterized by categories that are closed and crystallized

  11. Quantification of a radical beam source for methyl radicals

    A radical beam source for methyl radicals (CH3) was characterized applying ionization-threshold mass spectrometry. The beam source is based on thermal dissociation of methane (CH4) or azomethane (N2(CH3)2) in a heated tungsten capillary. A flux of (3±1)x1013 cm-2 s-1 CH3 radicals is produced using methane as precursor gas and a capillary temperature of 1650 K. Alternatively, a flux of (3±1)x1014 cm-2 s-1 CH3 is produced using azomethane as precursor gas and a capillary temperature of 1150 K. The dominant production of methyl from the precursor methane occurs due to reaction 2 CH4+M→2 CH3+H2+M at the hot tungsten surface. The dominant production of methyl from azomethane occurs due to the reaction N2(CH3)2→2 CH3+N2. Besides methyl radicals, only stable molecules contribute to the emitted flux; within the detection limit, no atomic hydrogen is observed. From the comparison of ionization-threshold mass spectrometry and standard mass spectrometry, it is concluded that the cracking pattern of methane varies with the methane gas temperature. This is explained by the vibrational assisted dissociation of methane

  12. Arabidopsis PIZZA has the capacity to acylate brassinosteroids.

    Katja Schneider

    Full Text Available Brassinosteroids (BRs affect a wide range of developmental processes in plants and compromised production or signalling of BRs causes severe growth defects. To identify new regulators of plant organ growth, we searched the Arabidopsis FOX (Full-length cDNA Over-eXpressor gene collection for mutants with altered organ size and isolated two overexpression lines that display typical BR deficient dwarf phenotypes. The phenotype of these lines, caused by an overexpression of a putative acyltransferase gene PIZZA (PIZ, was partly rescued by supplying exogenous brassinolide (BL and castasterone (CS, indicating that endogenous BR levels are rate-limiting for the growth of PIZ overexpression lines. Our transcript analysis further showed that PIZ overexpression leads to an elevated expression of genes involved in BR biosynthesis and a reduced expression of BR inactivating hydroxylases, a transcriptional response typical to low BR levels. Taking the advantage of relatively high endogenous BR accumulation in a mild bri1-301 background, we found that overexpression of PIZ results in moderately reduced levels of BL and CS and a strong reduction of typhasterol (TY and 6-deoxocastasterone (6-deoxoCS, suggesting a role of PIZ in BR metabolism. We tested a set of potential substrates in vitro for heterologously expressed PIZ and confirmed its acyltransferase activity with BL, CS and TY. The PIZ gene is expressed in various tissues but as reported for other genes involved in BR metabolism, the loss-of-function mutants did not display obvious growth phenotypes under standard growth conditions. Together, our data suggest that PIZ can modify BRs by acylation and that these properties might help modulating endogenous BR levels in Arabidopsis.

  13. Potential of acylated peptides to target the influenza A virus

    Daniel Lauster

    2015-04-01

    Full Text Available For antiviral drug design, especially in the field of influenza virus research, potent multivalent inhibitors raise high expectations for combating epidemics and pandemics. Among a large variety of covalent and non-covalent scaffold systems for a multivalent display of inhibitors, we created a simple supramolecular platform to enhance the antiviral effect of our recently developed antiviral Peptide B (PeBGF, preventing binding of influenza virus to the host cell. By conjugating the peptide with stearic acid to create a higher-order structure with a multivalent display, we could significantly enhance the inhibitory effect against the serotypes of both human pathogenic influenza virus A/Aichi/2/1968 H3N2, and avian pathogenic A/FPV/Rostock/34 H7N1 in the hemagglutination inhibition assay. Further, the inhibitory potential of stearylated PeBGF (C18-PeBGF was investigated by infection inhibition assays, in which we achieved low micromolar inhibition constants against both viral strains. In addition, we compared C18-PeBGF to other published amphiphilic peptide inhibitors, such as the stearylated sugar receptor mimicking peptide (Matsubara et al. 2010, and the “Entry Blocker” (EB (Jones et al. 2006, with respect to their antiviral activity against infection by Influenza A Virus (IAV H3N2. However, while this strategy seems at a first glance promising, the native situation is quite different from our experimental model settings. First, we found a strong potential of those peptides to form large amyloid-like supramolecular assemblies. Second, in vivo, the large excess of cell surface membranes provides an unspecific target for the stearylated peptides. We show that acylated peptides insert into the lipid phase of such membranes. Eventually, our study reveals serious limitations of this type of self-assembling IAV inhibitors.

  14. Generation of fatty acids by an acyl esterase in the bioluminescent system of Photobacterium phosphoreum

    The fatty acid reductase complex from Photobacterium phosphoreum has been discovered to have a long chain ester hydrolase activity associated with the 34K protein component of the complex. This protein has been resolved from the other components (50K and 58K) of the fatty acid reductase complex with a purity of > 95% and found to catalyze the transfer of acyl groups from acyl-CoA primarily to thiol acceptors with a low level of transfer to glycerol and water. Addition of the 50K protein of the complex caused a dramatic change in specificity increasing the transfer to oxygen acceptors. The acyl-CoA hydrolase activity increased almost 10-fold, and hence free fatty acids can be generated by the 34K protein when it is present in the fatty acid reductase complex. Hydrolysis of acyl-S-mercaptoethanol and acyl-1-glycerol and the ATP-dependent reduction of the released fatty acids to aldehyde for the luminescent reaction were also demonstrated for the reconstituted fatty acid reductase complex, raising the possibility that the immediate source of fatty acids for this reaction in vivo could be the membrane lipids and/or the fatty acid synthetase system

  15. A novel lysophosphatidylcholine acyl transferase activity is expressed by peroxiredoxin 6.

    Fisher, Aron B; Dodia, Chandra; Sorokina, Elena M; Li, Haitao; Zhou, Suiping; Raabe, Tobias; Feinstein, Sheldon I

    2016-04-01

    The phospholipase A2(PLA2) activity of peroxiredoxin (Prdx)6 has important physiological roles in the synthesis of lung surfactant and in the repair of peroxidized cell membranes. These functions require the activity of a lysophospholipid acyl transferase as a critical component of the phospholipid remodeling pathway. We now describe a lysophosphatidylcholine acyl transferase (LPCAT) activity for Prdx6 that showed a strong preference for lysophosphatidylcholine (LPC) as the head group and for palmitoyl CoA in the acylation reaction. The calculated kinetic constants for acylation wereKm18 μM andVmax30 nmol/min/mg protein; theVmaxwas increased 25-fold by phosphorylation of the protein whileKmwas unchanged. Study of recombinant protein in vitro and in mouse pulmonary microvascular endothelial cells infected with a lentiviral vector construct indicated that amino acid D31 is crucial for LPCAT activity. A linear incorporation of labeled fatty acyl CoA into dipalmitoyl phosphatidylcholine (PC) indicated that LPC generated by Prdx6 PLA2activity remained bound to the enzyme for the reacylation reaction. Prdx6 is the first LPCAT enzyme with demonstrated cytoplasmic localization. Thus, Prdx6 is a complete enzyme comprising both PLA2and LPCAT activities for the remodeling pathway of PC synthesis or for repair of membrane lipid peroxidation. PMID:26830860

  16. THE EFFECTS OF EXERCISE ON FOOD INTAKE AND HUNGER: RELATIONSHIP WITH ACYLATED GHRELIN AND LEPTIN

    Serife Vatansever-Ozen

    2011-06-01

    Full Text Available This study investigated the effects of a long bout of aerobic exercise on hunger and energy intake and circulating levels of leptin and acylated ghrelin. Ten healthy male subjects undertook two, 4 h trials in a randomized crossover design. In the exercise trial subjects ran for 105 min at 50% of maximal oxygen uptake and the last 15 min at 70% of maximal oxygen uptake followed by a 120 min rest period. In the control trial, subjects rested for 4 h. Subjects consumed a buffet test meal at 180 min during each trial. Hunger ratings, acylated ghrelin, leptin, glucose and insulin concentrations were measured at 0, 1, 2, 3 and 4 h. No differences were found at baseline values for hunger, acylated ghrelin, leptin, insulin and glucose for both trials (p > 0.05. The estimated energy expenditure of the exercise trial was 1550 ± 136 kcal. Exercise did not change subsequent absolute energy intake, but produced a significant decrease (p < 0.05 in relative energy intake. A two-way ANOVA revealed a significant (p < 0. 05 interaction effect for hunger and acylated ghrelin. In conclusion, this exercise regimen had a positive effect on reducing appetite which is related to reduced acylated ghrelin responses over time. This finding lends support for a role of exercise in weight management

  17. Detecting Social Polarization and Radicalization

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah; Wiil, Uffe Kock;

    2011-01-01

    This paper proposes a novel system to detect social polarization and to estimate the chances of violent radicalization associated with it. The required processes for such a system are indicated; it is also analyzed how existing technologies can be integrated into the proposed system to fulfill the...

  18. Exploring the Theories of Radicalization

    Maskaliūnaitė Asta

    2015-12-01

    Full Text Available After the London bombings in July 2005, the concern of terrorism scholars and policy makers has turned to “home-grown” terrorism and potential for political violence from within the states. “Radicalization” became a new buzz word. This article follows a number of reviews of the literature on radicalization and offers another angle for looking at this research. First, it discusses the term “radicalization” and suggests the use of the following definition of radicalization as a process by which a person adopts belief systems which justify the use of violence to effect social change and comes to actively support as well as employ violent means for political purposes. Next, it proposes to see the theories of radicalization focusing on the individual and the two dimensions of his/her motivation: whether that motivation is internal or external and whether it is due to personal choice or either internal (due to some psychological traits or external compulsion. Though not all theories fall neatly within these categories, they make it possible to make comparisons of contributions from a variety of different areas thus reflecting on the interdisciplinary nature of the study of terrorism in general and radicalization as a part of it.

  19. Kinetics of nitroxyl radical reactions

    Absolute rate-constants for the reaction of the nitroxyl free radicals TAN and TMPN with radiation-chemically-formed radicals and ions have been determined. k(TAN + X) (in M-1 sec-1) = 4.0 x 109 (for X =OH), 2.9 x 1010(esub(aq)-), 8.0 x 109 (H), 7.2 x 108 (CH2OH), 4.0 x 108 (CH3CHOH), 4.3 x 108 ((CH3)2COH), 2.8 x 108 (CH2(CH3)2COH), 5.9 x 107 (glucose radical), 4.0 x 108 (c-C5H9), and k(TMPN + X) = 3.4 x 109 (OH), 7.8 x 109 (esub(aq)-), 4.9 x 109 (H), 4.4 x 108 (CH2OH), 4.9 x 108 (CH3CHOH), 3.6 x 108 ((CH3)2COH), 1.5 x 108 (CH2(CH3)2COH), 4.9 x 107 (glucose radical), 4.3 x 108 (c-C5H9). Direct measurements by means of a pulse-radiolysis conductivity technique were based on the formation and destruction of charged species in these reactions within certain pH ranges. It is indicated that the radiosensitizing nitroxyles undergo both redox and addition reactions. (author)

  20. Reaction between protein radicals and other biomolecules

    Østdal, Henrik; Davies, Michael Jonathan; Andersen, Henrik J

    2002-01-01

    The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2....... Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid...

  1. Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity.

    Stojanović, Marija; Carević, Milica; Mihailović, Mladen; Veličković, Dušan; Dimitrijević, Aleksandra; Milosavić, Nenad; Bezbradica, Dejan

    2015-01-01

    Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L(-1) of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L(-1) of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes. PMID:25224149

  2. Proghrelin peptides: Desacyl ghrelin is a powerful inhibitor of acylated ghrelin, likely to impair physiological effects of acyl ghrelin but not of obestatin A study of pancreatic polypeptide secretion from mouse islets

    Kumar, Rajesh; Salehi, Albert; Rehfeld, Jens F;

    2010-01-01

    Proghrelin, produced by the ghrelin (A-like) cells of the gastric mucosa, gives rise to cleavage products, including desacyl ghrelin, acyl ghrelin and obestatin. The products are thought to be secreted concomitantly. In an earlier study we found acyl ghrelin and obestatin, but not desacyl ghrelin......, to suppress the release of hormones from isolated islets of mouse and rat pancreas....

  3. From Radical Translation to Radical Interpretation and Back

    António Zilhão

    2003-12-01

    Full Text Available Both Quine and Davidson put forth programs of empirical semantics satisfying the conditions that characterize the so-called “standpoint of interpretation.” Quine’s less ambitious program of radical translation rests upon two buttresses: causality and empathy. Davidson’s more ambitious program of radical interpretation replaces causality with truth and empathy with rationality. Although the replacement of causality with intersubjective truth seems to me to be a fully justified move, I nevertheless contend that it is more realistic to develop the work of interpretation drawing upon Quine’s less ambitious requirement of empathy than upon Davidson’s view of human agency as rational agency. In order to substantiate this contention, I present an argument to the effect that Davidson’s characterization of human agency as rational is not compatible with his other requirement that truth should pro-vide the essential link connecting speech with environment and action.

  4. S-Acylation of the cellulose synthase complex is essential for its plasma membrane localization.

    Kumar, Manoj; Wightman, Raymond; Atanassov, Ivan; Gupta, Anjali; Hurst, Charlotte H; Hemsley, Piers A; Turner, Simon

    2016-07-01

    Plant cellulose microfibrils are synthesized by a process that propels the cellulose synthase complex (CSC) through the plane of the plasma membrane. How interactions between membranes and the CSC are regulated is currently unknown. Here, we demonstrate that all catalytic subunits of the CSC, known as cellulose synthase A (CESA) proteins, are S-acylated. Analysis of Arabidopsis CESA7 reveals four cysteines in variable region 2 (VR2) and two cysteines at the carboxy terminus (CT) as S-acylation sites. Mutating both the VR2 and CT cysteines permits CSC assembly and trafficking to the Golgi but prevents localization to the plasma membrane. Estimates suggest that a single CSC contains more than 100 S-acyl groups, which greatly increase the hydrophobic nature of the CSC and likely influence its immediate membrane environment. PMID:27387950

  5. Long-chain acyl-CoA esters in metabolism and signaling

    Neess, Ditte; Sørensen, Signe Bek; Engelsby, Hanne; Gallego, Sandra F; Færgeman, Nils J.

    2015-01-01

    Long-chain fatty acyl-CoA esters are key intermediates in numerous lipid metabolic pathways, and recognized as important cellular signaling molecules. The intracellular flux and regulatory properties of acyl-CoA esters have been proposed to be coordinated by acyl-CoA-binding domain containing...... proteins (ACBDs). The ACBDs, which comprise a highly conserved multigene family of intracellular lipid-binding proteins, are found in all eukaryotes and ubiquitously expressed in all metazoan tissues, with distinct expression patterns for individual ACBDs. The ACBDs are involved in numerous intracellular...... processes including fatty acid-, glycerolipid- and glycerophospholipid biosynthesis, β-oxidation, cellular differentiation and proliferation as well as in the regulation of numerous enzyme activities. Little is known about the specific roles of the ACBDs in the regulation of these processes, however, recent...

  6. The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis.

    Van Vranken, Jonathan G; Jeong, Mi-Young; Wei, Peng; Chen, Yu-Chan; Gygi, Steven P; Winge, Dennis R; Rutter, Jared

    2016-01-01

    Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4'-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis. PMID:27540631

  7. Synthesis of 1-isopropyl-3-acyl-5-methyl-benzimidazolone Derivatives and Their Antimicrobial Activity

    Shaopeng Wei

    2013-03-01

    Full Text Available A series of N-acylated analogues of 1-isopropyl-3-acyl-5-methyl-benzimidazolone were synthesized. Bioassay results indicated that analogues 5-07 and 5-19 exhibited the most potency against Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Analogues 5-02, 5-07, 5-12, 5-15, 5-19, 5-20 and 5-25 could effectively inhibit the spore germination of Botrytis cinerea. The relationship between structure and their antimicrobial activity (SAR has also been discussed according to aliphatic acids and aromatic acids derivatives, respectively. This implied that the N-acylated derivatives of 5-methyl-benzimidazolone might be potential antimicrobial agents.

  8. Enzyme:substrate hydrogen bond shortening during the acylation phase of serine protease catalysis.

    Fodor, Krisztián; Harmat, Veronika; Neutze, Richard; Szilágyi, László; Gráf, László; Katona, Gergely

    2006-02-21

    Atomic resolution (acyl-enzyme intermediate (N-acetyl-Asn-Pro-Ile acyl-enzyme intermediate of porcine pancreatic elastase at 0.95 A resolution) presumably synchronously with the nucleophilic attack on the carbonyl carbon atom of the scissile peptide bond. This is interpreted as an active mechanism that utilizes the energy released from the stronger hydrogen bonds to overcome the energetic barrier of the nucleophilic attack by the hydroxyl group of the catalytic serine. In the CFT:SGTI complex this hydrogen bond shortening may be hindered by the 27I-32I disulfide bridge and Asn-15I of SGTI. The position of the catalytic histidine changes slightly as it adapts to the different nucleophilic attacker during the transition from the Michaelis complex to the acyl-enzyme state, and simultaneously its interaction with Asp-102 and Ser-214 becomes stronger. The oxyanion hole hydrogen bonds provide additional stabilization for acyl-ester bond in the acyl-enzyme than for scissile peptide bond of the Michaelis complex. Significant deviation from planarity is not observed in the reactive bonds of either the Michaelis complex or the acyl-enzyme. In the Michaelis complex the electron distribution of the carbonyl bond is distorted toward the oxygen atom compared to other peptide bonds in the structure, which indicates the polarization effect of the oxyanion hole. PMID:16475800

  9. Natural variability in acyl moieties of sugar esters produced by certain tobacco and other Solanaceae species.

    Kroumova, Antoaneta B M; Zaitlin, Dave; Wagner, George J

    2016-10-01

    A unique feature of glandular trichomes of plants in the botanical family Solanaceae is that they produce sugar esters (SE), chemicals that have been shown to possess insecticidal, antifungal, and antibacterial properties. Sugar esters of tobacco (Nicotiana tabacum) provide pest resistance, and are important flavor precursors in oriental tobacco cultivars. Acyl moieties of SEs in Nicotiana spp., petunia, and tomato are shown to vary with respect to carbon length and isomer structure (2-12 carbon chain length; anteiso-, iso-, and straight-chain). Sugar esters and their acyl groups could serve as a model to explore the basis of phenotypic diversity and adaptation to natural and agricultural environments. However, information on the diversity of acyl composition among species, cultivars, and accessions is lacking. Herein, described is the analysis of SE acyl groups found in 21 accessions of Nicotiana obtusifolia (desert tobacco), six of Nicotiana occidentalis subsp. hesperis, three of Nicotiana alata, two of N. occidentalis, four modern tobacco cultivars, five petunia hybrids, and one accession each of a primitive potato (Solanum berthaultii) and tomato (Solanum pennellii). A total of 20 different acyl groups was observed that were represented differently among cultivars, species, and accessions. In Nicotiana species, acetate and iso- and anteiso-branched acids prevailed. Straight-chain groups (2-8 carbons) were prominent in petunias, while octanoic acid was prominent in N. alata and N. × sanderae. Two unexpected acyl groups, 8-methyl nonanoate and decanoate were found in N. occidentalis subsp. hesperis. Longer chain groups were found in the petunia, tomato, and potato species studied. PMID:27262877

  10. Kinetics of acyl transfer reactions in organic media catalysed by Candida antarctica lipase B.

    Martinelle, M; Hult, K

    1995-09-01

    The acyl transfer reactions catalysed by Candida antartica lipase B in organic media followed a bi-bi ping-pong mechanism, with competitive substrate inhibition by the alcohols used as acyl acceptors. The effect of organic solvents on Vm and Km was investigated. The Vm values in acetonitrile was 40-50% of those in heptane. High Km values in acetonitrile compared to those in heptane could partly be explained by an increased solvation of the substrates in acetonitrile. Substrate solvation caused a 10-fold change in substrate specificity, defined as (Vm/Km)ethyl octanoate/(Vm/Km)octanoic acid, going from heptane to acetonitrile. Deacylation was the rate determining step for the acyl transfer in heptane with vinyl- and ethyl octanoate as acyl donors and (R)-2-octanol as acyl acceptor. With 1-octanol, a rate determining deacylation step in heptane was indicated using the same acyl donors. Using 1-octanol as acceptor in heptane, S-ethyl thiooctanoate had a 25- to 30-fold lower Vm/Km value and vinyl octanoate a 4-fold higher Vm/Km value than that for ethyl octanoate. The difference showed to be a Km effect for vinyl octanoate and mainly a Km effect for S-ethyl thiooctanoate. The Vm values of the esterification of octanoic acid with different alcohols was 10-30-times lower than those for the corresponding transesterification of ethyl octanoate. The low activity could be explained by a low pH around the enzyme caused by the acid or a withdrawing of active enzyme by nonproductive binding by the acid. PMID:7669809

  11. The ppm operon is essential for acylation and glycosylation of lipoproteins in Corynebacterium glutamicum.

    Niloofar Mohiman

    Full Text Available BACKGROUND: Due to their contribution to bacterial virulence, lipoproteins and members of the lipoprotein biogenesis pathway represent potent drug targets. Following translocation across the inner membrane, lipoprotein precursors are acylated by lipoprotein diacylglycerol transferase (Lgt, cleaved off their signal peptides by lipoprotein signal peptidase (Lsp and, in Gram-negative bacteria, further triacylated by lipoprotein N-acyl transferase (Lnt. The existence of an active apolipoprotein N-acyltransferase (Ms-Ppm2 involved in the N-acylation of LppX was recently reported in M. smegmatis. Ms-Ppm2 is part of the ppm operon in which Ppm1, a polyprenol-monophosphomannose synthase, has been shown to be essential in lipoglycans synthesis but whose function in lipoprotein biosynthesis is completely unknown. RESULTS: In order to clarify the role of the ppm operon in lipoprotein biosynthesis, we investigated the post-translational modifications of two model lipoproteins (AmyE and LppX in C. glutamicum Δppm1 and Δppm2 mutants. Our results show that both proteins are anchored into the membrane and that their N-termini are N-acylated by Cg-Ppm2. The acylated N-terminal peptide of LppX was also found to be modified by hexose moieties. This O-glycosylation is localized in the N-terminal peptide of LppX and disappeared in the Δppm1 mutant. While compromised in the absence of Cg-Ppm2, LppX O-glycosylation could be restored when Cg-Ppm1, Cg-Ppm2 or the homologous Mt-Ppm1 of M. tuberculosis was overexpressed. CONCLUSION: Together, these results show for the first time that Cg-Ppm1 (Ppm synthase and Cg-Ppm2 (Lnt operate in a common biosynthetic pathway in which lipoprotein N-acylation and glycosylation are tightly coupled.

  12. Electron attachment to fluorocarbon radicals

    Shuman, Nicholas

    2014-10-01

    Most plasma environments contain populations of short-lived species such as radicals, the chemistry of which can have significant effects on the overall chemistry of the system. However, few experimental measurements of the kinetics of electron attachment to radicals exist due to the inherent difficulties of working with transient species. Calculations from first principles have been attempted, but are arduous and, because electron attachment is so sensitive to the specifics of the potential surface, their accuracy has not been established. Electron attachment to small fluorocarbon radicals is particularly important, as the data are needed for predictive modeling of plasma etching of semiconductor materials, a key process in the industrial fabrication of microelectronics. We have recently developed a novel flowing afterglow technique to measure several types of otherwise difficult to study plasma processes, including thermal electron attachment to radicals. Variable Electron and Neutral Density Attachment Mass Spectrometry (VENDAMS) exploits dissociative electron attachment in a weakly ionized plasma as a radical source. Here, we apply VENDAMS to a series of halofluorocarbon precursors in order to measure the kinetics of thermal electron attachment to fluorocarbon radicals. Results are presented for CF2, CF3, C2F5,C2F3,1-C3F7, 2-C3F7, and C3F5 from 300 K to 900 K. Both the magnitude and the temperature dependences of rate coefficients as well as product branching between associative and dissociative attachment are highly system specific; however, thermal attachment to all species is inefficient, never exceeding 5% of the collision rate. The data are analyzed using a recently developed kinetic modeling approach, which uses extended Vogt-Wannier theory as a starting point, accounts for dynamic effects such as coupling between the electron and nuclear motions through empirically validated functional forms, and finally uses statistical theory to determine the fate of

  13. Thermoregulation of N-Acyl Homoserine Lactone-Based Quorum Sensing in the Soft Rot Bacterium Pectobacterium atrosepticum▿

    Latour, Xavier; Diallo, Stéphanie; Chevalier, Sylvie; Morin, Danièle; Smadja, Bruno; Burini, Jean-François; Haras, Dominique; Orange, Nicole

    2007-01-01

    The psychrotolerant bacterium Pectobacterium atrosepticum produces four N-acyl homoserine lactones under a wide range of temperatures. Their thermoregulation differs from that of the exoenzyme production, described as being under quorum-sensing control. A mechanism involved in this thermoregulation consists of controlling N-acyl homoserine lactones synthase production at a transcriptional level.

  14. Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

    Demant, Erland J.F.; Nystrøm, Birthe T.

    2001-01-01

    acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

  15. Thermoregulation of N-Acyl Homoserine Lactone-Based Quorum Sensing in the Soft Rot Bacterium Pectobacterium atrosepticum▿

    Latour, Xavier; Diallo, Stéphanie; Chevalier, Sylvie; Morin, Danièle; Smadja, Bruno; Burini, Jean-François; Haras, Dominique; Orange, Nicole

    2007-01-01

    The psychrotolerant bacterium Pectobacterium atrosepticum produces four N-acyl homoserine lactones under a wide range of temperatures. Their thermoregulation differs from that of the exoenzyme production, described as being under quorum-sensing control. A mechanism involved in this thermoregulation consists of controlling N-acyl homoserine lactones synthase production at a transcriptional level. PMID:17468275

  16. Long-chain acyl-CoA-dependent regulation of gene expression in bacteria, yeast and mammals

    Black, P N; Færgeman, Nils J.; DiRusso, C C

    2000-01-01

    Fatty acyl-CoA thioesters are essential intermediates in lipid metabolism. For many years there have been numerous conflicting reports concerning the possibility that these compounds also serve regulatory functions. In this review, we examine the evidence that long-chain acyl-CoA is a regulatory ...

  17. Acylation, Diastereoselective Alkylation, and Cleavage of an Oxazolidinone Chiral Auxiliary: A Multistep Asymmetric Synthesis Experiment for Advanced Undergraduates

    Smith, Thomas E.; Richardson, David P.; Truran, George A.; Belecki, Katherine; Onishi, Megumi

    2008-01-01

    An introduction to the concepts and experimental techniques of diastereoselective synthesis using a chiral auxiliary is described. The 4-benzyl-2-oxazolidinone chiral auxiliary developed by Evans is acylated with propionic anhydride under mild conditions using DMAP as an acyl transfer catalyst. Deprotonation with NaN(TMS)[subscript 2] at -78…

  18. A simple, effective, green method for regioselective 3-acylation of unprotected indoles

    Tran, Phuong Huong; Tran, Hai N.; Hansen, Poul Erik; Do, Mai Hoang Ngoc; Le, Thach N

    2015-01-01

    A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)3 in catalytic amounts is found to be...... the best catalyst together with the commercially available ionic liquid [BMI]BF4 (1-butyl-3-methylimidazolium tetrafluoro-borate) as solvent. The reaction is completed in a very short time using monomode microwave irradiation. The catalyst can be reused up to four times without significant loss of...

  19. Coenzyme A-acylating aldehyde dehydrogenase from Clostridium beijerinckii NRRL B592.

    Yan, R T; Chen, J S

    1990-01-01

    Acetaldehyde and butyraldehyde are substrates for alcohol dehydrogenase in the production of ethanol and 1-butanol by solvent-producing clostridia. A coenzyme A (CoA)-acylating aldehyde dehydrogenase (ALDH), which also converts acyl-CoA to aldehyde and CoA, has been purified under anaerobic conditions from Clostridium beijerinckii NRRL B592. The ALDH showed a native molecular weight (Mr) of 100,000 and a subunit Mr of 55,000, suggesting that ALDH is dimeric. Purified ALDH contained no alcohol...

  20. Mutations in the medium chain acyl-CoA dehydrogenase (MCAD) gene

    Tanaka, K; Yokota, I; Coates, P M; Strauss, A W; Kelly, D P; Zhang, Z; Gregersen, N; Andresen, B S; Matsubara, Y; Curtis, D

    1992-01-01

    Medium chain acyl-CoA dehydrogenase (MCAD) catalyzes the first reaction of the beta-oxidation cycle for 4-10-carbon fatty acids. MCAD deficiency is one of the most frequent inborn metabolic disorders in populations of northwestern European origin. In the compilation of data from a worldwide study......, which causes impairment of tetramer assembly and instability of the protein. Three of 7 rarer mutations have been identified in a few unrelated patients, while the remaining 4 have each been found in only a single pedigree. In addition to tabulating the mutations, the acyl-CoA dehydrogenase gene family...

  1. Synthesis and evaluation of 3-acyl-tetronic acid-containing metal complexing agents

    Potential metal chelators containing one or several acyl-tetronic acid moieties were prepared from cyclic or acyclic amines and polyamines, and from bis(phenols) by reaction with 1-4 equiv of 3 bromoacetyl-tetronic acid in the presence of potassium carbonate. The affinity constants of the chelating agents for toxic metallic cations Cd2+, Cs+, and Pb2+ and for dimethylarsinic acid were measured, at pH 7.5 and 9.3. Compound 4, an acyclic triamine containing four acyl-tetronic moieties, was found to complex efficiently all the tested species. (authors)

  2. Purification of specific structured lipids by distillation: Effects on acyl migration

    Xu, Xuebing; Skands, A.; Adler-Nissen, Jens

    2001-01-01

    contained a large amount of free fatty acids and a small amount of partial acylglycerols besides triacylglycerols. Therefore, the effect of steam, free fatty acids, diacylglycerols, and monoacylglycerols on acyl migration was studied in a palm oil midfraction model. The results showed that all these factors......The cause and effects of acyl migration during the purification of specific structured lipids by distillation were studied in a conventional batch deodorizer with stripping steam. The mixture of specific structured lipids produced by lipase-catalyzed acidolysis between rapeseed oil and capric acid...

  3. Acyl-CoA-binding protein/diazepam-binding inhibitor gene and pseudogenes

    Mandrup, S; Hummel, R; Ravn, S;

    1992-01-01

    Acyl-CoA-binding protein (ACBP) is a 10 kDa protein isolated from bovine liver by virtue of its ability to bind and induce the synthesis of medium-chain acyl-CoA esters. Surprisingly, it turned out to be identical to a protein named diazepam-binding Inhibitor (DBI) claimed to be an endogenous...... remarkable correspondence between the structural modules of ACBP/DBI as determined by 1H nuclear magnetic resonance spectroscopy and the exon-intron architecture of the ACBP/DBI gene. Detailed analyses of transcription of the ACBP/DBI gene in brain and liver were performed to map transcription initiation...

  4. Synthesis and Biological Activity Evaluation of Schiff Bases of 5-Acyl-1,2,4-Triazine

    A simple and general method has been developed for the synthesis of various Schiff bases (oximes, hydrazones, semicarbazones and thiosemicarbazones) derived from 5-acyl-1,2,4-triazines. Some of the new synthesized Schiff bases were tested for biological activity but only oximes 2a-c shown poor antiviral activity. The oxime derivatives of 5-acyl-3-methylsulfanyl-1,2,4-triazine were tested with pea-seedling diamine oxidase as the enzyme is known to be inhibited by oxime compounds. However, only weak non-competitive inhibitory effects were observed (Ki of 10 /sup -2/ M). (author)

  5. Age dependent accumulation of N-acyl-ethanolamine phospholipids in ischemic rat brain

    Moesgaard, B.; Petersen, G.; Hansen, Harald S.;

    2000-01-01

    N-acyl-ethanolamine phospholipids (NAPE) can be formed as a stress response during neuronal injury, and they are precursors for N-acyl- ethanolamines (NAE), some of which are endocannabinoids. The levels of NAPE accumulated during post-decapitative ischemia (6 h at 37°C) were studied in rat brains...... of various age (1, 6, 12, 19, 30, and ~70 days) by the use of P NMR spectroscopy of lipid extracts. This ability to accumulate NAPE was compared with the activity of N-acyltransferase and of NAPE-hydrolyzing phospholipase D (NAPE-PLD) in brain microsomes. These two enzymes are involved in the formation...

  6. Synthesis of N-Acylated Amino Acid Surfactant from L-Proline and Palmitoyl Chloride

    A biodegradable, less toxic and environmentally friendly N-acylated amino acid surfactant was prepared from the amino acid L-proline and palmitoyl chloride through acylation reaction using the Schotten-Baumann reaction condition. The reaction result was a white flake form and the percentage of the crude yield was 72 % with melting point in range of 52 - 58 degree Celsius. Functional group of amide which was detected using Fourier Transform Infrared method showed the presence of N-palmitoyl proline. The purity analysis using High Performance Liquid Chromatography and Thin Layer Chromatography showed the result was a mixture compound. (author)

  7. Radical carbonylations using a continuous microflow system

    Takahide Fukuyama

    2009-07-01

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

  8. EPR spin trapping of protein radicals

    Davies, Michael Jonathan; Hawkins, Clare L

    2004-01-01

    Electron paramagnetic resonance (EPR) spin trapping was originally developed to aid the detection of low-molecular-mass radicals formed in chemical systems. It has subsequently found widespread use in biology and medicine for the direct detection of radical species formed during oxidative stress...... selected examples of radical formation on proteins....

  9. Free radicals and Dupuytren's contracture.

    Murrell, G. A.; Francis, M. J.; Bromley, L.

    1987-01-01

    The concentration of substrate expressed as hypoxanthine capable of reacting with xanthine oxidase to release superoxide free radicals (O2-) was measured in control and Dupuytren's contracture palmar fascia. In Dupuytren's contracture palmar fascia the concentration of hypoxanthine was six times that of control and was greatest in "nodular" areas. Xanthine oxidase activity was also detected in Dupuytren's contracture palmar fascia. These results suggest a greater potential for hypoxanthine-xa...

  10. S-acylation dependent post-translational cross-talk regulates large conductance calcium- and voltage- activated potassium (BK channels

    MichaelJShipston

    2014-08-01

    Full Text Available Mechanisms that control surface expression and/or activity of large conductance calcium-activated potassium (BK channels are important determinants of their (pathophysiological function. Indeed, BK channel dysfunction is associated with major human disorders ranging from epilepsy to hypertension and obesity. S-acylation (S-palmitoylation represents a major reversible, post-translational modification controlling the properties and function of many proteins including ion channels. Recent evidence reveals that both pore-forming and regulatory subunits of BK channels are S-acylated and control channel trafficking and regulation by AGC-family protein kinases. The pore-forming α-subunit is S-acylated at two distinct sites within the N- and C-terminus, each site being regulated by different palmitoyl acyl transferases (zDHHCs and acyl thioesterases. (APTs. S-acylation of the N-terminus controls channel trafficking and surface expression whereas S-acylation of the C-terminal domain determines regulation of channel activity by AGC-family protein kinases. S-acylation of the regulatory β4-subunit controls ER exit and surface expression of BK channels but does not affect ion channel kinetics at the plasma membrane. Furthermore, a significant number of previously identified BK-channel interacting proteins have been shown, or are predicted to be, S-acylated. Thus, the BK channel multi-molecular signalling complex may be dynamically regulated by this fundamental post-translational modification and thus S-acylation likely represents an important determinant of BK channel physiology in health and disease.

  11. 40 CFR 721.10193 - 1-Butanaminium, N-(3-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts.

    2010-07-01

    ...-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. 721.10193 Section 721.10193 Protection of...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. (a) Chemical substance and...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts (PMN P-06-263, Chemical B; CAS...

  12. Chemical repair of trypsin-histidinyl radical

    Oxyl radicals, such as hydroxyl, alkoxyl and peroxyl, react with biomolecules to produce bioradicals. Unless chemically repaired by suitable antioxidants, these bioradicals form stable products. This leads to loss of biological function of parent biomolecules with deleterious biological results, such as mutagenesis and cancer. Consequently, the understanding of the mechanisms of oxyl radical damage to biomolecules and chemical repair of such damage is crucial for the development of strategies for anticarcinogenesis and radioprotection. In this study the chemical repair of the histidinyl radical generated upon the trichloromethylperoxyl radical reaction with trypsin vas investigated by gamma radiolysis. The trypsin histidinyl radical is a resonance-stabilized heterocyclic free radical which was found to be unreactive with oxygen. The efficacy of the chemical repair of the trypsin-histidinyl radical by endogenous antioxidants which are electron donors (e.g. 5-hydroxytryptophan, uric acid) is compared to that of antioxidants which are H-atom donors (e. g. glutathione). 9 refs., 2 figs., 1 tab

  13. Iron-Catalyzed Acylation of Polyfunctionalized Aryl- and Benzylzinc Halides with Acid Chlorides.

    Benischke, Andreas D; Leroux, Marcel; Knoll, Irina; Knochel, Paul

    2016-08-01

    FeCl2 (5 mol %) catalyzes a smooth and convenient acylation of functionalized arylzinc halides at 50 °C (2-4 h) and benzylic zinc chlorides at 25 °C (0.5-4 h) with a variety of acid chlorides leading to polyfunctionalized diaryl and aryl heteroaryl ketones. PMID:27457108

  14. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    The high-resolution NMR structure of the acyl-carrier protein from the pathogen B. burgdorferi determined to a r.m.s. deviation of 0.4 Å over the protein backbone is reported. The NMR structure was determined using multidimensional NMR spectroscopy and consists of four α-helices and two 310-helices. Structural comparison reveals that this protein is highly similar to the acyl-carrier protein from A. aeolicus. Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% of side-chain resonances using multidimensional NMR spectroscopy. The NMR structure was determined to a backbone r.m.s.d. of 0.4 Å and contained four α-helices and two 310-helices. A structure-homology search revealed that this protein is highly similar to the acyl-carrier protein from Aquifex aeolicus

  15. How Chain Length and Charge Affect Surfactant Denaturation of Acyl Coenzyme A Binding Protein (ACBP)

    Andersen, Kell Kleiner; Otzen, Daniel

    2009-01-01

    Using intrinsic tryptophan fluorescence, equilibria and kinetics of unfolding of acyl coenzyme A binding protein (ACBP) have been investigated in sodium alkyl sulfate surfactants of different chain length (8-16 carbon atoms) and with different proportions of the nonionic surfactant dodecyl maltos...

  16. A Rational Approach to Identify Inhibitors of Mycobacterium tuberculosis Enoyl Acyl Carrier Protein Reductase

    Chhabria, M. T.; Parmar, K. B.; Brahmkshatriya, Pathik

    2013-01-01

    Roč. 19, č. 21 (2013), s. 3878-3883. ISSN 1381-6128 Institutional support: RVO:61388963 Keywords : mycobacterium tuberculosis * enoyl acyl carrier protein reductase * pharmacophore modeling * molecular docking * binding interactions Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.288, year: 2013

  17. In vitro and in vivo aspects of N-acyl-phosphatidylethanolamine-containing liposomes

    Vermehren, C.; Clausen-Beck, B.; Frøkjær, S.; Hansen, Harald S.

    2003-01-01

    Incorporation of the phospholipid, N-acyl-phosphatidylethanolamine (NAPE), has shown to increase the liposomal stability towards plasma components in vitro. Besides increasing the circulation-time, NAPE has been shown to contain fusiogenic properties. Hence, fusion between NAPE-liposomes and targ...

  18. New Rare Sinapoyl Acylated Flavonoid Glycosides Obtained from the Seeds of Lepidium apetalum Willd

    Lifeng Han; Pingping Shi; Yongzhe Dong; Tingting Wang; Xiaoxia Li; Jia Hao; Yi Zhang; Tao Wang

    2015-01-01

    Seven new rare sinapoyl acylated flavonoid glycosides, apetalumosides A1 (1), B8 (2), B9 (3), B10 (4), B11 (5), B12 (6), and C1 (7) were isolated from the seeds of Lepidium apetalum Willd. Their structures were elucidated by chemical and spectroscopic methods.

  19. Alkylation of phenols and acylation 2-methoxynaphthalene over SSZ-33, SSZ-35 and SSZ-42 zeolites

    Vitvarová, Dana; Lupínková, Lenka; Kubů, Martin

    2015-01-01

    Roč. 210, JUL 2015 (2015), s. 133-141. ISSN 1387-1811 R&D Projects: GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : phenol alkylation * 2-methoxynaphthalene acylation * SSZ-33 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.453, year: 2014

  20. REGIOSPECIFIC ANALYSIS OF DIRICINOLEOYL-ACYL-GLYCEROL IN CASTOR OIL USING ELECTROSPRAY IONIZATION-MASS SPECTROMETRY

    HPLC fractions of castor oil were used to identify the regiospecific location of non-hydroxyl fatty acids on glycerol backbone in diricinoleoyl-acyl-glycerols using electrospray ionization MS3 of lithium adducts. The regiospecific ions in MS3 spectra were from the loss of 'a,B'-unsaturated fatty aci...

  1. TFFH as an excellent reagent for acylation of alcohols, thiols and dithiocarbamates

    Pittelkow, M.; Kamounah, F. S.; Boas, Ulrik;

    2004-01-01

    A convenient and easy procedure to synthesize esters and thioesters from the corresponding carboxylic acid using TFFH as the coupling reagent is described. The preparation of N-acyl-dithiocarbamates from carboxylic acids and 1,3-thiazolidine-2-thione with TFFH as the coupling reagent is also...

  2. Influence of fatty acid desaturation on spontaneous acyl migration in 2-monoacylglycerols

    The effect of desaturation from the C9 to the C15 carbon of 2-monoacylglycerol (2-MAG) fatty acids on spontaneous acyl migration is described. Density functional calculations for 2-monooleoylglycerol (C18:cis-delta9), 2-monolinoleoylglycerol (C18:cis-delta9,12), and 2-monolinolenoylglycerol (C18:cis...

  3. In vivo metabolism of fumonisin B1 to N-acylated ceramide-like compounds

    Fumonisins are toxic and carcinogenic mycotoxins found in corn-based foods. Fumonisin B1 (FB1) metabolism to ceramide-like cytotoxic N-acylated FB1 (NAFB1) compounds has been shown in vitro, but in vivo metabolism has not been reported. Therefore, male Sprague-Dawley rats (2/group) were given 5 da...

  4. Genome-level and biochemical diversity of the acyl-activating enzyme superfamily in plants

    In higher plants, the superfamily of carboxyl-CoA ligases and related proteins, collectively called acyl activating enzymes (AAEs), has evolved to provide enzymes for many pathways of primary and secondary metabolism and for the conjugation of hormones to amino acids. Across the superfamily there is...

  5. Proton NMR: a convenient method for determining 2-monoacylglycerol acyl migration

    The acyl migration kinetics of neat (not exposed to solvent) 2-monoacylglycerol (2-MAG) to form 1-monoacylglycerol (1-MAG) was determined using proton NMR spectroscopy to monitor the B-proton integration ratios of the two species over time. 2-MAG was synthesized by the Novozym 435-catalyzed alcohol...

  6. Ghrelin, Des-Acyl Ghrelin, and Obestatin: Regulatory Roles on the Gastrointestinal Motility

    Mineko Fujimiya

    2010-01-01

    Full Text Available Ghrelin, des-acyl ghrelin, and obestatin are derived from a common prohormone, preproghrelin by posttranslational processing, originating from endocrine cells in the stomach. To examine the regulatory roles of these peptides, we applied the manometric measurement of gastrointestinal motility in freely moving conscious rat or mouse model. Ghrelin exerts stimulatory effects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum but not on the motility of duodenum in the fasted state of animals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state but not in the fasted state of animals. NPY Y2 and Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptor in the brain may mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain may mediate the action of obestatin. Vagal afferent pathways might be involved in the action of ghrelin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.

  7. Selective Monoacylation of Ferrocene with Bulky Acylating Agents over Mesoporous Sieve AlKIT-5

    Vitvarová, Dana; Voláková, Martina; Vlk, Josef; Vinu, A.; Štěpnička, P.; Čejka, Jiří

    2010-01-01

    Roč. 16, č. 26 (2010), s. 7773-7780. ISSN 0947-6539 R&D Projects: GA ČR GA104/07/0383; GA ČR GD203/08/H032 Institutional research plan: CEZ:AV0Z40400503 Keywords : acylation * aluminum * ferrocene Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.476, year: 2010

  8. Acyl-CoA synthetase 1 deficiency alters cardiolipin species and impairs mitochondrial function

    Grevengoed, Trisha J; Martin, Sarah A; Katunga, Lalage; Cooper, Daniel E; Anderson, Ethan J; Murphy, Robert C; Coleman, Rosalind A

    2015-01-01

    Long-chain acyl-CoA synthetase 1 (ACSL1) contributes more than 90% of total cardiac ACSL activity, but its role in phospholipid synthesis has not been determined. Mice with an inducible knockout of ACSL1 (Acsl1(T-/-)) have impaired cardiac fatty acid oxidation and rely on glucose for ATP producti...

  9. Acyl migration kinetics of 2-monoacylglycerols from soybean oil via 1 hour Nuclear Magnetic Resonance (NMR)

    The acyl migration kinetics of neat 2-monoacylglycerol (2-MAG) to form 1-monoacylglycerol (1-MAG) was determined using proton NMR spectroscopy to monitor the beta-proton integration ratios of the two species over time. 2-MAG was synthesized by the Novozym 435-catalyzed alcoholysis of soybean oil an...

  10. Liver fatty acid binding protein (LFABP) transfers fatty acids and fatty acyl coas to membranes

    De Gerónimo, Eduardo; Hagan, Robert M; Wilton, David C.; Córsico, Betina

    2010-01-01

    The objective of this work was to analyze LFABP´s capacity to transfer acyl CoAs to artificial membranes and compare it to LCFA transfer employing natural ligands, in order to better understand the specific physiological role of LFABP in the cell.

  11. gfp-based N-acyl homoserine-lactone sensor systems for detection of bacterial communication

    Andersen, Jens Bo; Heydorn, Arne; Hentzer, Morten; Eberl, Leo; Geisenberger, Otto; Christensen, Bjarke Bak; Molin, Søren; Givskov, Michael Christian

    2001-01-01

    In order to perform single-cell analysis and online studies of N-acyl homoserine lactone (AHL)-mediated communication among bacteria, components of the Vibrio fischeri quorum sensor encoded by luxR-P-luxI have been fused to modified versions of gfpmut3* genes encoding unstable green fluorescent...

  12. Different effects of ghrelin, des-acyl ghrelin and obestatin on gastroduodenal motility in conscious rats

    Mineko Fujimiya; Aldhiro Asakawa; Koji Ataka; Ikuo Kato; Akio Inui

    2008-01-01

    Three peptides, ghrelin, des-acyl ghrelin and obestatin are derived from a common prohormone, preproghre-lin by posttranslational processing, originating from endocrine cells in the stomach. To examine the effects of these peptides, we applied the manometric mea-surement of gastrointestinal motility in freely moving conscious rat models. Ghrelin exerts stimulatory ef-fects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum, but not on the motility of duodenum in the fasted state of ani-mals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state, but not in the fasted state of animals. NPY Y2 or Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptors in the brain mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain mediate the action of obestatin. Vagal affer-ent pathways might be involved in the action of ghre-lin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.

  13. Medium chain acyl-CoA dehydrogenase deficiency and fatal valproate toxicity

    Njolstad, PR; Skjeldal, OH; Agsteribbe, E; Huckriede, A; Wannag, E; Sovik, O; Waaler, PE

    1997-01-01

    A boy with delayed psychomotor development, attention deficit disorder, and therapy-resistant epilepsy was treated with valproate. The patient died of liver failure after 4 months of valproate treatment. Postmortem investigation of cultured fibroblasts suggested medium chain acyl-CoA dehydrogenase d

  14. Isolation and Purification of a Novel Long-chain Acyl Catechin from Lipophilic Tea Polyphenols

    陈平; 杜琪珍

    2003-01-01

    Llpophilic tea polyphenols (LTP) was prepared by esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long-chaln acyl catechin was isolated and purified from LTP by high-speed countercurrent chromatography (HSCCC).Its molecular structure was elucidated as epigallocatechin-3-O-gallate-4'-O-hexadecanate by elemental analysis, IR, MS and 1H NMR spectra.

  15. An orphan esterase ABHD10 modulates probenecid acyl glucuronidation in human liver.

    Ito, Yusuke; Fukami, Tatsuki; Yokoi, Tsuyoshi; Nakajima, Miki

    2014-12-01

    Probenecid, a widely used uricosuric agent, is mainly metabolized to probenecid acyl glucuronide (PRAG), which is considered a causal substance of severe allergic or anaphylactoid reactions. PRAG can be hydrolyzed (deglucuronidated) to probenecid. The purpose of this study was to identify enzymes responsible for probenecid acyl glucuronidation and PRAG deglucuronidation in human livers and to examine the effect of deglucuronidation in PRAG formation. In human liver homogenates (HLHs), the intrinsic clearance (CLint) of PRAG deglucuronidation was much greater (497-fold) than that of probenecid acyl glucuronidation. Evaluation of PRAG formation by recombinant UDP-glucuronosyltransferase (UGT) isoforms and an inhibition study using HLHs as an enzyme source demonstrated that multiple UGT isoforms, including UGT1A1, UGT1A9, and UGT2B7, catalyzed probenecid acyl glucuronidation. We found that recombinant α/β hydrolase domain containing 10 (ABHD10) substantially catalyzed PRAG deglucuronidation activity, whereas carboxylesterases did not. Similar inhibitory patterns by chemicals between HLHs and recombinant ABHD10 supported the major contribution of ABHD10 to PRAG deglucuronidation in human liver. Interestingly, it was demonstrated that the CLint value of probenecid acyl glucuronidation in HLHs was increased by 1.7-fold in the presence of phenylmethylsulfonyl fluoride, which potently inhibited ABHD10 activity. In conclusion, we found that PRAG deglucuronidation catalyzed by ABHD10 suppressively regulates PRAG formation via multiple UGT enzymes in human liver. The balance of activities by these enzymes is important for the formation of PRAG, which may be associated with the adverse reactions observed after probenecid administration. PMID:25217485

  16. Sticky swinging arm dynamics: studies of an acyl carrier protein domain from the mycolactone polyketide synthase.

    Vance, Steven; Tkachenko, Olga; Thomas, Ben; Bassuni, Mona; Hong, Hui; Nietlispach, Daniel; Broadhurst, William

    2016-04-15

    Type I modular polyketide synthases (PKSs) produce polyketide natural products by passing a growing acyl substrate chain between a series of enzyme domains housed within a gigantic multifunctional polypeptide assembly. Throughout each round of chain extension and modification reactions, the substrate stays covalently linked to an acyl carrier protein (ACP) domain. In the present study we report on the solution structure and dynamics of an ACP domain excised from MLSA2, module 9 of the PKS system that constructs the macrolactone ring of the toxin mycolactone, cause of the tropical disease Buruli ulcer. After modification ofapoACP with 4'-phosphopantetheine (Ppant) to create theholoform,(15)N nuclear spin relaxation and paramagnetic relaxation enhancement (PRE) experiments suggest that the prosthetic group swings freely. The minimal chemical shift perturbations displayed by Ppant-attached C3and C4acyl chains imply that these substrate-mimics remain exposed to solvent at the end of a flexible Ppant arm. By contrast, hexanoyl and octanoyl chains yield much larger chemical shift perturbations, indicating that they interact with the surface of the domain. The solution structure of octanoyl-ACP shows the Ppant arm bending to allow the acyl chain to nestle into a nonpolar pocket, whereas the prosthetic group itself remains largely solvent exposed. Although the highly reduced octanoyl group is not a natural substrate for the ACP from MLSA2, similar presentation modes would permit partner enzyme domains to recognize an acyl group while it is bound to the surface of its carrier protein, allowing simultaneous interactions with both the substrate and the ACP. PMID:26920023

  17. Iron and iron derived radicals

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fast! Think small! In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab

  18. Aromatic-radical oxidation chemistry

    Glassman, I.; Brezinsky, K. [Princeton Univ., NJ (United States)

    1993-12-01

    The research effort has focussed on discovering an explanation for the anomalously high CO{sub 2} concentrations observed early in the reaction sequence of the oxidation of cyclopentadiene. To explain this observation, a number of plausible mechanisms have been developed which now await experimental verification. One experimental technique for verifying mechanisms is to probe the reacting system by perturbing the radical concentrations. Two forms of chemical perturbation of the oxidation of cyclopentadiene were begun during this past year--the addition of NO{sub 2} and CO to the reacting mixture.

  19. Laser spectroscopy of hydrocarbon radicals

    Chen, P. [Harvard Univ., Cambridge, MA (United States)

    1993-12-01

    The author reports the application of supersonic jet flash pyrolysis to the specific preparation of a range of organic radicals, biradicals, and carbenes in a skimmed molecular beam. Each species was produced cleanly and specifically, with little or no secondary reactions by the thermal dissociation of appropriately designed and synthesized organic precursors. Photoelectron spectra of the three isomeric C{sub 3}H{sub 2} carbenes, ortho-benzyne, and the {alpha},3-dehydrotoluene biradical, were used to establish adiabatic ionization potentials for use in thermochemical determinations.

  20. Efficient mono-acylation of fructose by lipase-catalyzed esterification in ionic liquid co-solvents.

    Li, Lu; Ji, Fangling; Wang, Jingyun; Jiang, Bo; Li, Yachen; Bao, Yongming

    2015-10-30

    Fructose monoesters are eco-friendly nonionic surfactants in various applications. Selective preparation of mono-acylated fructose is challenging due to the multiple hydroxyl sites available for acylation both chemically and enzymatically. Ionic liquids (ILs) have profound impacts not only on the reaction media but also on the catalytic properties of enzymes in the acylation process. In this study, utilizing an IL co-solvent system, selective synthesis of mono-acylated fructose with lauric acid catalyzed by immobilized Candida antarctica lipase B (CALB) was investigated. The imidazolium-based ILs selected as co-solvents with 2-methyl-2-butanol (2M2B) markedly improved the ratios of monolauroyl fructose in the presence of 60% [BMIM][TfO] (v/v) and 20% [BMIM][BF4] (v/v), in which the mono-acylated fructose was 85% and 78% respectively. Based on a Ping-Pong Bi-Bi model, a kinetic equation was fitted, by which the kinetic parameters revealed that the affinity between fructose and acyl-enzyme intermediate was enhanced. The inhibition effect of fructose on free enzyme was weakened in the presence of IL co-solvents. The conformation of CALB binding substrates also changed in the co-solvent system as demonstrated by Fourier transform infrared spectra. These results demonstrated that the variation of CALB kinetic characteristics was a crucial factor for the selectivity of mono-acylation in ILs/2M2B co-solvents. PMID:26343327

  1. Detection of a secondary muoniated radical

    McCollum, Brett M.; Brodovitch, Jean-Claude [TRIUMF and Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6 (Canada); Clyburne, Jason A.C. [Department of Chemistry, Saint Mary' s University, Halifax, NS, B3H 3C3 (Canada); Percival, Paul W., E-mail: percival@sfu.c [TRIUMF and Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6 (Canada); West, Robert [Organosilicon Research Center, University of Wisconsin, Madison, WI 53706 (United States)

    2009-04-15

    Muoniated free radicals are formed by addition of muonium to unsaturated molecules. Successful detection by transverse-field muon spin rotation (muSR) usually requires pure or highly concentrated samples and a muonium reaction rate in excess of 10{sup 9} M{sup -1}s{sup -1} to ensure that the muon spin polarization is coherently transferred to the radical. For this reason muoniated radicals reported to date are all the primary radical products of Mu reaction. Thus, it was expected that Mu addition to a silylene would result in detection of a silyl radical. However, the muon hyperfine constant determined by experiment is much smaller than the value predicted by density functional calculations. Instead, it is consistent with a disilanyl radical, the secondary radical formed by reaction of the initially formed silyl radical with a second silylene molecule. From an analysis of the signal amplitude it was deduced that the second-order rate constant for reaction of the muoniated silyl radical with the parent silylene is 5.7x10{sup 8} M{sup -1}s{sup -1}. This work represents the first example of direct detection of a secondary radical product by transverse-field muSR.

  2. Selection of processing tomato genotypes with high acyl sugar content that are resistant to the tomato pinworm.

    Dias, D M; Resende, J T V; Faria, M V; Camargo, L K P; Chagas, R R; Lima, I P

    2013-01-01

    Acyl sugars are allelochemicals present at high concentrations in leaves of accessions of the wild tomato Solanum pennellii; they confer resistance to a large number of arthropod pests, including the tomato pinworm, Tuta absoluta (Lepidoptera, Gelechiidae). Accession 'LA716', with high contents of acyl sugars in the leaves, was used as a source of resistance to start a genetic breeding program of processing cultivated tomato, S. lycopersicum. We selected plants of the F₂ generation of an interspecific cross (S. lycopersicum cv. 'Redenção' x S. pennellii 'LA716') for extremes of concentrations (high and low) of acyl sugars in the leaves and evaluated the resistance of selected genotypes to the tomato pinworm, compared with plants of the parental and F₁ generations. The concentrations of acyl sugars present in the genotypes selected for high contents were close to those of S. pennellii 'LA 716', while the genotypes with low concentrations of acyl sugars were close to cultivar 'Redenção'. The F₁ hybrid ('Redenção' x 'LA716') had intermediate concentrations of acyl sugars, but was closer to Redenção, indicating that the inheritance of this type of character is due to a recessive major gene, along with minor genes with additive effects. There was a direct association between high contents of acyl sugars and non-preference for oviposition and suppression of larval development, indicating that the allelochemical acts through mechanisms of non-preference for oviposition and through antibiosis. Genotypes with high contents of acyl sugars were more effective in reducing the damage caused by the tomato pinworm. Genotypes RVTA-2010pl#94 and RVTA-2010pl#31, selected for high contents of acyl sugars, showed a good level of resistance to T. absoluta, similar to the wild genotype LA716. These genotypes are promising for use in a breeding program for developing commercial processing tomatoes. PMID:23420362

  3. S-naproxen-ss-1-O-acyl glucuronide degradation kinetic studies by stopped-flow high-performance liquid chromatography-H-1 NMR and high-performance liquid chromatography-UV

    Mortensen, R. W.; Corcoran, O.; Cornett, Claus;

    2001-01-01

    Acyl-migrated isomers of drug beta -1-O-acyl glucuronides have been implicated in drug toxicity because they can bind to proteins. The acyl migration and hydrolysis of S-naproxen-beta -1-O-acyl glucuronide (S-nap-g) was followed by dynamic stopped-flow HPLC-H-1 NMR and HPLC methods. Nine first or...

  4. The pharmacokinetics of naproxen, its metabolite O-desmethylnaproxen, and their acyl glucuronides in humans. Effect of cimetidine.

    Vree, T.B.; van den Biggelaar-Martea, M; Verwey-Van Wissen, C P; Vree, M L; Guelen, P J

    1993-01-01

    1. The pharmacokinetics of 500 mg naproxen given orally were described in 10 subjects using a direct h.p.l.c. analysis of the acyl glucuronide conjugates of naproxen and its metabolite O-desmethylnaproxen. 2. The mean elimination half-life of naproxen was 24.7 +/- 6.4 h (range 7 to 36 h). 3. Naproxen acyl glucuronide accounted for 50.8 +/- 7.3% of the dose recovered in the urine, its isomerised conjugate isoglucuronide for 6.5 +/- 2.0%, O-desmethylnaproxen acyl glucuronide for 14.3 +/- 3.4%, ...

  5. A Radically Configurable Six-State Compound

    Barnes, Jonathan C.; Fahrenbach, Albert C.; Cao, Dennis; Dyar, Scott M.; Frasconi, Marco; Giesener, Marc A.; Benítez, Diego; Tkatchouk, Ekaterina; Chernyashevskyy, Oleksandr; Shin, Weon Ho; Li, Hao; Sampath, Srinivasan; Stern, Charlotte L.; Sarjeant, Amy A.; Hartlieb, Karel J.

    2013-01-01

    Most organic radicals possess short lifetimes and quickly undergo dimerization or oxidation. Here, we report on the synthesis by radical templation of a class of air- and water-stable organic radicals, trapped within a homo[2]catenane composed of two rigid and fixed cyclobis (paraquat-p-phenylene) rings. The highly energetic octacationic homo[2]catenane, which is capable of accepting up to eight electrons, can be configured reversibly, both chemically and electrochemically, bet...

  6. Quantitative determination of atmospheric hydroperoxyl radical

    Springston, Stephen R. (Upton, NY); Lloyd, Judith (Westbury, NY); Zheng, Jun (Stony Brook, NY)

    2007-10-23

    A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

  7. Photodynamically generated bovine serum albumin radicals

    Silvester, J A; Timmins, G S; Davies, Michael Jonathan

    1998-01-01

    Porphyrin-sensitized photoxidation of bovine serum albumin (BSA) results in oxidation of the protein at (at least) two different, specific sites: the Cys-34 residue giving rise to a thiyl radical (RS.); and one or both of the tryptophan residues (Trp-134 and Trp-214) resulting in the formation of...... by a range of proteases. The generation of protein-derived radicals also results in an enhancement of photobleaching of the porphyrin, suggesting that protein radical generation is linked to porphyrin photooxidation....

  8. Involvement of free radicals in breast cancer

    Ríos-Arrabal, Sandra; Artacho-Cordón, Francisco; León, Josefa; Román-Marinetto, Elisa; del Mar Salinas-Asensio, María; Calvente, Irene; Núñez, Maria Isabel

    2013-01-01

    Researchers have recently shown an increased interest in free radicals and their role in the tumor microenvironment. Free radicals are molecules with high instability and reactivity due to the presence of an odd number of electrons in the outermost orbit of their atoms. Free radicals include reactive oxygen and nitrogen species, which are key players in the initiation and progression of tumor cells and enhance their metastatic potential. In fact, they are now considered a hallmark of cancer. ...

  9. Optimal pain management for radical prostatectomy surgery

    Joshi, Grish P; Jaschinski, Thomas; Bonnet, Francis; Kehlet, Henrik

    2015-01-01

    evidence to develop an optimal pain management protocol in patients undergoing radical prostatectomy. Most studies assessed unimodal analgesic approaches rather than a multimodal technique. There is a need for more procedure-specific studies comparing pain and analgesic requirements for open and minimally...... invasive surgical procedures. Finally, while we wait for appropriate procedure specific evidence from publication of adequate studies assessing optimal pain management after radical prostatectomy, we propose a basic analgesic guideline.......BACKGROUND: Increase in the diagnosis of prostate cancer has increased the incidence of radical prostatectomy. However, the literature assessing pain therapy for this procedure has not been systematically evaluated. Thus, optimal pain therapy for patients undergoing radical prostatectomy remains...

  10. Near-Ring Radicals and Class Pairs

    L.Godloza; N.J.Groenewald; W.A.Olivier

    2005-01-01

    For near-ring ideal mappings p1 and p2, we investigate radical theoretical properties of and the relationship among the class pairs (p1: p2), (Sp2: Sp1) and (Rp2:Rp1). Conditions on p1 and p2 are given for a general class pair to form a radical class of various types. These types include the Plotkin and KA-radical varieties. A number of examples are shown to motivate the suitability of the theory of Hoehnke-radicals over KA-radicals when radical pairs of near-rings are studied. In particular, it is shown that (pc: P3) forms a KA-radical class, where Pc denotes the class of completely prime nearrings and P3 the class of 3-prime near-rings. This gives another near-ring generalization of the 2-primal ring concept. The theory of radical pairs are also used to show that in general the class of 3-semiprime near-rings is not the semisimple class of the 3-prime radical.

  11. Dynamics of Radical-Mediated Enzyme Catalyses

    Warncke, Kurt

    1997-11-01

    An emergent class of enzymes harnesses the extreme reactivity of electron-deficient free radical species to perform some of the most difficult reactions in biology. The regio- and stereo-selectivity achieved by these enzymes defies long-held ideas that radical reactions are non-specific. The common primary step in these catalyses is metal- or metallocenter-assisted generation of an electron-deficient organic "initiator radical". The initiator radical abstracts a hydrogen atom from the substrate, opening a new reaction channel for rearrangement to the product. Our aim is to elucidate the detailed molecular mechanisms of the radical pair separation and radical rearrangement steps. Radical pair separation and substrate radical rearrangement are tracked by using time-resolved (10-7 to 10-3 s) techniques of pulsed-electron paramagnetic resonance spectroscopy (FT-EPR, ESEEM). Synchronous time-evolution of the reactions is attained by triggering with a visible laser pulse. Transient non-Boltzmann population of the states of the spin-coupled systems, and resultant electron spin polarization, facilitates study at or near room temperature under conditions where the enzymes are operative. The systems examined include ethanolamine deaminase, a vitamin B12 coenzyme-dependent enzyme, ribonucleotide reductase and photosynthetic reaction centers. The electronic and nuclear structural and kinetic information obtained from the pulsed-EPR studies is used to address how the initiator radicals are stabilized against deleterious recombination with the metal, and to distinguish the participation of concerted versus sequential rearrangement pathways.

  12. Serum Levels of Acyl-Carnitines along the Continuum from Normal to Alzheimer's Dementia

    Sapere, Nadia; La Marca, Giancarlo; Angiolillo, Antonella; Vitale, Michela; Corbi, Graziamaria; Scapagnini, Giovanni; Intrieri, Mariano; Russo, Claudio

    2016-01-01

    This study aimed to determine the serum levels of free L-carnitine, acetyl-L-carnitine and 34 acyl-L-carnitine in healthy subjects and in patients with or at risk of Alzheimer’s disease. Twenty-nine patients with probable Alzheimer’s disease, 18 with mild cognitive impairment of the amnestic type, 24 with subjective memory complaint and 46 healthy subjects were enrolled in the study, and the levels of carnitine and acyl-carnitines were measured by tandem mass spectrometry. The concentrations of acetyl-L-carnitine progressively decreased passing from healthy subjects group (mean±SD, 5.6±1.3 μmol/L) to subjective memory complaint (4.3±0.9 μmol/L), mild cognitive impairment (4.0±0.53 μmol/L), up to Alzheimer’s disease (3.5±0.6 μmol/L) group (p<0.001). The differences were significant for the comparisons: healthy subjects vs. subjective memory complaint, mild cognitive impairment or Alzheimer’s disease group; and subjective memory complaint vs. Alzheimer’s disease group. Other acyl-carnitines, such as malonyl-, 3-hydroxyisovaleryl-, hexenoyl-, decanoyl-, dodecanoyl-, dodecenoyl-, myristoyl-, tetradecenoyl-, hexadecenoyl-, stearoyl-, oleyl- and linoleyl-L-carnitine, showed a similar decreasing trend, passing from healthy subjects to patients at risk of or with Alzheimer’s disease. These results suggest that serum acetyl-L-carnitine and other acyl-L-carnitine levels decrease along the continuum from healthy subjects to subjective memory complaint and mild cognitive impairment subjects, up to patients with Alzheimer’s disease, and that the metabolism of some acyl-carnitines is finely connected among them. These findings also suggest that the serum levels of acetyl-L-carnitine and other acyl-L-carnitines could help to identify the patients before the phenotype conversion to Alzheimer’s disease and the patients who would benefit from the treatment with acetyl-L-carnitine. However, further validation on a larger number of samples in a longitudinal

  13. Serum Levels of Acyl-Carnitines along the Continuum from Normal to Alzheimer's Dementia.

    Adriana Cristofano

    Full Text Available This study aimed to determine the serum levels of free L-carnitine, acetyl-L-carnitine and 34 acyl-L-carnitine in healthy subjects and in patients with or at risk of Alzheimer's disease. Twenty-nine patients with probable Alzheimer's disease, 18 with mild cognitive impairment of the amnestic type, 24 with subjective memory complaint and 46 healthy subjects were enrolled in the study, and the levels of carnitine and acyl-carnitines were measured by tandem mass spectrometry. The concentrations of acetyl-L-carnitine progressively decreased passing from healthy subjects group (mean±SD, 5.6±1.3 μmol/L to subjective memory complaint (4.3±0.9 μmol/L, mild cognitive impairment (4.0±0.53 μmol/L, up to Alzheimer's disease (3.5±0.6 μmol/L group (p<0.001. The differences were significant for the comparisons: healthy subjects vs. subjective memory complaint, mild cognitive impairment or Alzheimer's disease group; and subjective memory complaint vs. Alzheimer's disease group. Other acyl-carnitines, such as malonyl-, 3-hydroxyisovaleryl-, hexenoyl-, decanoyl-, dodecanoyl-, dodecenoyl-, myristoyl-, tetradecenoyl-, hexadecenoyl-, stearoyl-, oleyl- and linoleyl-L-carnitine, showed a similar decreasing trend, passing from healthy subjects to patients at risk of or with Alzheimer's disease. These results suggest that serum acetyl-L-carnitine and other acyl-L-carnitine levels decrease along the continuum from healthy subjects to subjective memory complaint and mild cognitive impairment subjects, up to patients with Alzheimer's disease, and that the metabolism of some acyl-carnitines is finely connected among them. These findings also suggest that the serum levels of acetyl-L-carnitine and other acyl-L-carnitines could help to identify the patients before the phenotype conversion to Alzheimer's disease and the patients who would benefit from the treatment with acetyl-L-carnitine. However, further validation on a larger number of samples in a longitudinal

  14. The Games Radicals Play: Special Issue on Free Radicals and Radical Ions

    John C. Walton

    2015-02-01

    Full Text Available Chemistry and Physics have aptly been described as “most excellent children of Intellect and Art” [1]. Both these “children” engage with many playthings, and molecules rank as one of their first favorites, especially radicals, which are amongst the most lively and exciting. Checking out radicals dancing to the music of entropy round their potential energy ballrooms is surely both entertaining and enlightening. Radicals’ old favorite convolutions are noteworthy, but the new styles, modes and arrangements appearing on the scene are even more interesting. Some of these are ephemeral and enjoy only a brief appearance, others are retro-types reappearing in new guises, still others are genuinely new and “go viral” in the scientific world. This Special Issue of Molecules contains the observations and reflections of a select group of chemists and physicists fascinated by this spectacle. It contains an eclectic mix reflecting on new modes and advances as well as on permutations and combinations that revive mature themes. [...

  15. Characterization of Two Members among the Five ADP-Forming Acyl Coenzyme A (Acyl-CoA) Synthetases Reveals the Presence of a 2-(Imidazol-4-yl)Acetyl-CoA Synthetase in Thermococcus kodakarensis

    Awano, Tomotsugu; Wilming, Anja; Tomita, Hiroya; Yokooji, Yuusuke; Fukui, Toshiaki; Imanaka, Tadayuki; Atomi, Haruyuki

    2014-01-01

    The genome of Thermococcus kodakarensis, along with those of most Thermococcus and Pyrococcus species, harbors five paralogous genes encoding putative α subunits of nucleoside diphosphate (NDP)-forming acyl coenzyme A (acyl-CoA) synthetases. The substrate specificities of the protein products for three of these paralogs have been clarified through studies on the individual enzymes from Pyrococcus furiosus and T. kodakarensis. Here we have examined the biochemical properties of the remaining t...

  16. Photoionisation of the tropyl radical

    Kathrin H. Fischer

    2013-04-01

    Full Text Available We present a study on the photoionisation of the cycloheptatrienyl (tropyl radical, C7H7, using tunable vacuum ultraviolet synchrotron radiation. Tropyl is generated by flash pyrolysis from bitropyl. Ions and electrons are detected in coincidence, permitting us to record mass-selected photoelectron spectra. The threshold photoelectron spectrum of tropyl, corresponding to the X+ 1A1’ ← X 2E2” transition, reveals an ionisation energy of 6.23 ± 0.02 eV, in good agreement with Rydberg extrapolations, but slightly lower than the value derived from earlier photoelectron spectra. Several vibrations can be resolved and are reassigned to the C–C stretch mode ν16+ and to a combination of ν16+ with the ring breathing mode ν2+. Above 10.55 eV dissociative photoionisation of tropyl is observed, leading to the formation of C5H5+ and C2H2.

  17. Radical surgery in septic abortion.

    Chatterjee, P; Ghosh, M; Ghosh, S

    1979-08-01

    At R.G. Kar Medical College Hospital, Calcutta, 10 cases of septic abortion from 1975-1977 were studied. Hysterectomies were preformed on 4 cases due to emergency situations including traumatised uterine fundus and perforated cervix, and on 6 cases after conservative treatment. Upon performing laparotomy in 9 cases, a uterine rent was detected; in 1 case there was a perforation in the posterior wall of the cervix, and in 5 cases mechanical obstructions due to internal adhesions to the uterine rent were found. 4 patients died primarily because of the patients seeking help too late. It is suggested that under high risk circumstances, laparotomy is advantageous to conservative medical management since bowel injuries and mechanical obstructions can only be detected by laparotomy. Radical surgery, however, should be undertaken before the patients general condition deteriorates to the point that the patient cannot tolerate surgical intervention. PMID:12336028

  18. Students' Ideas and Radical Constructivism

    Sánchez Gómez, Pedro J.

    2016-08-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

  19. Students' Ideas and Radical Constructivism

    Sánchez Gómez, Pedro J.

    2016-04-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

  20. Iron and iron derived radicals

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  1. Inhibitory effects of chitosan on superoxide anion radicals and lipid free radicals

    2002-01-01

    With the electron spin resonance (ESR) technique, the inhibitory effects of chitosan on superoxide anion radicals and linoleic acid lipid radicals were found. The inhibitory ratio E for these two kinds of radicals is in proportion to the concentration of chitosan. It was also observed that E for linoleic acid lipid radicals increased with the increase of the degree of deacetylation and decreased with the increase of the molecular weight of chitosan.

  2. Transgenic rice seed expressing flavonoid biosynthetic genes accumulate glycosylated and/or acylated flavonoids in protein bodies

    Ogo, Yuko; Mori, Tetsuya; Nakabayashi, Ryo; Saito, Kazuki; Takaiwa, Fumio

    2015-01-01

    Highlight Glycosylated and/or acylated flavonoids in transgenic rice seeds were characterized by metabolome analysis, suggesting that ectopic expression of flavonoid biosynthetic enzymes can be used as a tool to expand their structural diversity.

  3. Reactivity of TEMPO anion as a nucleophile and its applications for selective transformations of haloalkanes or acyl halides to aldehydes

    Inokuchi, Tsutomu; Kawafuchi, Hiroyuki

    2004-01-01

    Sodium 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO−Na+), generated by reduction of TEMPO· with sodium naphthalenide in THF, reacted with alkyl halides or acyl halides to produce O-alkylated or acylated TEMPOs, which were in turn oxidized with mCPBA or reduced with DIBAL-H to afford the corresponding aldehydes, thus accomplishing a new protocol for the halides-carbonyls conversion.

  4. Acyl-chain remodeling of dioctanoyl-phosphatidylcholine in Saccharomyces cerevisiae mutant defective in de novo and salvage phosphatidylcholine synthesis

    Kishino, Hideyuki; Eguchi, Hiroki; Takagi, Keiko; Horiuchi, Hiroyuki; Fukuda, Ryouichi; Ohta, Akinori, E-mail: aaohta@isc.chubu.ac.jp

    2014-03-07

    Highlights: • Dioctanoyl-PC (diC8PC) supported growth of a yeast mutant defective in PC synthesis. • diC8PC was converted to PC species containing longer acyl residues in the mutant. • Both acyl residues of diC8PC were replaced by longer fatty acids in vitro. • This system will contribute to the elucidation of the acyl chain remodeling of PC. - Abstract: A yeast strain, in which endogenous phosphatidylcholine (PC) synthesis is controllable, was constructed by the replacement of the promoter of PCT1, encoding CTP:phosphocholine cytidylyltransferase, with GAL1 promoter in a double deletion mutant of PEM1 and PEM2, encoding phosphatidylethanolamine methyltransferase and phospholipid methyltransferase, respectively. This mutant did not grow in the glucose-containing medium, but the addition of dioctanoyl-phosphatidylcholine (diC8PC) supported its growth. Analyses of the metabolism of {sup 13}C-labeled diC8PC ((methyl-{sup 13}C){sub 3}-diC8PC) in this strain using electrospray ionization tandem mass spectrometry revealed that it was converted to PC species containing acyl residues of 16 or 18 carbons at both sn-1 and sn-2 positions. In addition, both acyl residues of (methyl-{sup 13}C){sub 3}-diC8PC were replaced with 16:1 acyl chains in the in vitro reaction using the yeast cell extract in the presence of palmitoleoyl-CoA. These results indicate that PC containing short acyl residues was remodeled to those with acyl chains of physiological length in yeast.

  5. The pharmacokinetics of naproxen, its metabolite O-desmethylnaproxen, and their acyl glucuronides in humans. Effect of cimetidine.

    Vree, T B; Van Den Biggelaar-Martea, M; Verwey-Van Wissen, C P; Vree, M L; Guelen, P J

    1993-05-01

    1. The pharmacokinetics of 500 mg naproxen given orally were described in 10 subjects using a direct h.p.l.c. analysis of the acyl glucuronide conjugates of naproxen and its metabolite O-desmethylnaproxen. 2. The mean elimination half-life of naproxen was 24.7 +/- 6.4 h (range 7 to 36 h). 3. Naproxen acyl glucuronide accounted for 50.8 +/- 7.3% of the dose recovered in the urine, its isomerised conjugate isoglucuronide for 6.5 +/- 2.0%, O-desmethylnaproxen acyl glucuronide for 14.3 +/- 3.4%, and its isoglucuronide for 5.5 +/- 1.3%. Naproxen and O-desmethylnaproxen were excreted in negligible amounts (< 1%). 4. Even though the urine pH of the subjects was kept acid in order to stabilize the acyl glucuronides, isomerisation took place in blood. 5. The extents of plasma binding of the unconjugated compounds were 98% (naproxen) and 100% (O-desmethylnaproxen), while naproxen acyl glucuronide binding was 92%; that of its isomer isoglucuronide 66%. O-desmethylnaproxen acyl glucuronide was 72% bound and its isoglucuronide was 42% bound. 6. Cimetidine (400 mg twice daily) decreased the t1/2 of naproxen by 39-60% (mean 47.3 +/- 11.5%; P = 0.0014) from 24.7 +/- 6.4 h to 13.2 +/- 1.0 h. It increased (10%) the urinary recovery of naproxen acyl glucuronide (P = 0.0492). The urinary recoveries of naproxen isoglucuronide and O-desmethylnaproxen acyl glucuronide remained unchanged. PMID:8512758

  6. Serum acylated ghrelin concentrations in response to short-term overfeeding in normal weight, overweight, and obese men.

    Danny Wadden

    Full Text Available BACKGROUND: Ghrelin, an orexigenic gut hormone secreted primarily from the stomach, is involved in energy homeostasis. However, little data is available regarding its response to energy surplus and the development of human obesity. OBJECTIVE: The present study investigated the response of circulating acylated ghrelin to a 7-day positive energy challenge. DESIGN: A total of 68 healthy young men were overfed 70% more calories than required, for 1-week. Subjects were classified based on percent body fat (measured by dual-energy X-ray absorptiometry as normal weight, overweight, and obese. Serum acylated ghrelin concentration was measured before and after the positive energy challenge. Additionally, the relationship between acylated ghrelin and obesity-related phenotypes including weight, body mass index, percent body fat, cholesterol, HDL-c, LDL-c, glucose, insulin and homeostasis model assessment of insulin resistance and β-cell function at baseline and change due to overfeeding, were assessed. RESULTS: Contrary to our expectations, serum acylated ghrelin was significantly increased in response to overfeeding and the increase was independent of obesity status. There was no significant difference in fasting acylated ghrelin between normal weight, overweight, and obese men at baseline. Acylated ghrelin was negatively correlated with weight and BMI for normal weight and with BMI in overweight men. Also ghrelin was correlated with change in weight and BMI in overweight (negative relationship and obese (positive relationship groups. CONCLUSION: Our results showed that circulating acylated ghrelin was increased after a 7-day positive energy challenge regardless of adiposity status. However, acylated ghrelin was correlated with change in weight and BMI in opposing directions, in overweight and obese subjects respectively, thus dependent on obesity status.

  7. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    NICOLAY K; Smaal, E B; de Kruijff, B.

    1986-01-01

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal systems, indicative of acyl chain disordering.

  8. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal system, indicative of acyl chain disordering. (Auth.)

  9. Synthesis and characterization of Trichloroisocyanouric acid functionalized mesoporous silica nanocomposite (SBA/TCCA) for the Acylation of Indole

    G ROBIN WILSON; AMIT DUBEY

    2016-08-01

    Trichloroisocyanouric acid (TCCA)-functionalized mesoporous silica nanocomposites (SBA/TCCA) were synthesized and characterized for the acylation of indole. The uniform incorporation of TCCA inside the SBA-15 matrix was confirmed by standard characterization techniques (PXRD, Adsorption studies, FT-IR, etc.). The catalytic activity studies of SBA/TCCA nanocomposites for acylation of indole showed high selectivity (60–90%) of the 3-acetyl indole compared to homogeneous TCCA (50%). The advantage of solid support for higher selectivity is also explained.

  10. The innate reactivity of a membrane associated peptide towards lipids : acyl transfer to melittin without enzyme catalysis.

    Dods, R.H.; Mosely, J.A.; Sanderson, J M

    2012-01-01

    The innate reactivity of the peptide melittin (H-GIGAVLKVLTTGLPALISWIKRKRQQ-NH2) towards membrane lipids has been explored using LC-MS methods. The high sensitivity afforded by LC-MS analysis enabled acyl transfer to the peptide to be detected, within 4 h, from membranes composed of phosphocholines (PCs). Acyl transfer from PCs was also observed from mixtures of PC with phosphoserine (PS) or phosphoglycerol (PG). In the latter case, transfer from PG was also detected. The half-lives for melit...

  11. Acyl-chain remodeling of dioctanoyl-phosphatidylcholine in Saccharomyces cerevisiae mutant defective in de novo and salvage phosphatidylcholine synthesis

    Highlights: • Dioctanoyl-PC (diC8PC) supported growth of a yeast mutant defective in PC synthesis. • diC8PC was converted to PC species containing longer acyl residues in the mutant. • Both acyl residues of diC8PC were replaced by longer fatty acids in vitro. • This system will contribute to the elucidation of the acyl chain remodeling of PC. - Abstract: A yeast strain, in which endogenous phosphatidylcholine (PC) synthesis is controllable, was constructed by the replacement of the promoter of PCT1, encoding CTP:phosphocholine cytidylyltransferase, with GAL1 promoter in a double deletion mutant of PEM1 and PEM2, encoding phosphatidylethanolamine methyltransferase and phospholipid methyltransferase, respectively. This mutant did not grow in the glucose-containing medium, but the addition of dioctanoyl-phosphatidylcholine (diC8PC) supported its growth. Analyses of the metabolism of 13C-labeled diC8PC ((methyl-13C)3-diC8PC) in this strain using electrospray ionization tandem mass spectrometry revealed that it was converted to PC species containing acyl residues of 16 or 18 carbons at both sn-1 and sn-2 positions. In addition, both acyl residues of (methyl-13C)3-diC8PC were replaced with 16:1 acyl chains in the in vitro reaction using the yeast cell extract in the presence of palmitoleoyl-CoA. These results indicate that PC containing short acyl residues was remodeled to those with acyl chains of physiological length in yeast

  12. New acylated flavone and cyanogenic glycosides from Linum grandiflorum

    Mohammed, Magdy M. D.; Christensen, Lars Porskjær; Ibrahim, Nabaweya A.;

    2009-01-01

    The first investigation of Linum grandiflorum resulted in the isolation of one new acylated flavone O-diglycoside known as luteolin 7-O-a-D-(6000-E-feruloyl)glucopyranosyl (1!2)--D-glucopyranoside, and one new cyanogenic glycoside known as 2-[(30-isopropoxy-O--D-glucopyranosyl)oxy]-2-methylbutane......The first investigation of Linum grandiflorum resulted in the isolation of one new acylated flavone O-diglycoside known as luteolin 7-O-a-D-(6000-E-feruloyl)glucopyranosyl (1!2)--D-glucopyranoside, and one new cyanogenic glycoside known as 2-[(30-isopropoxy-O--D-glucopyranosyl)oxy]-2......-methylbutanenitrile, together with four known flavonoid glycosides, three known cyanogenic glycosides and one alkyl glycoside. The new compounds were structurally elucidated via the extensive 1D, 2D NMR and DIFNOE together with ESI-TOFCID-MS/MS and HR-MALDI/MS....

  13. Structure of armadillo ACBP: a new member of the acyl-CoA-binding protein family

    The X-ray structure of the tetragonal form of apo acyl-CoA-binding protein (ACBP) from the Harderian gland of the South American armadillo Chaetophractus villosus has been solved. The X-ray structure of the tetragonal form of apo acyl-CoA-binding protein (ACBP) from the Harderian gland of the South American armadillo Chaetophractus villosus has been solved. ACBP is a carrier for activated long-chain fatty acids and has been associated with many aspects of lipid metabolism. Its secondary structure is highly similar to that of the corresponding form of bovine ACBP and exhibits the unique flattened α-helical bundle (up–down–down–up) motif reported for animal, yeast and insect ACBPs. Conformational differences are located in loops and turns, although these structural differences do not suffice to account for features that could be related to the unusual biochemistry and lipid metabolism of the Harderian gland

  14. Structure of armadillo ACBP: a new member of the acyl-CoA-binding protein family

    Costabel, Marcelo D., E-mail: costabel@criba.edu.ar [Grupo de Biofísica, Departamento de Física, Universidad Nacional del Sur, Bahía Blanca (Argentina); Ermácora, Mario R. [Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal (Argentina); Santomé, José A. [Instituto de Química y Fisicoquímica Biológicas (IQUIFYB), Facultad de Farmacia y Bioquímica (UBA-CONICET), Buenos Aires (Argentina); Alzari, Pedro M. [Unité de Biochimie Structurale, Institut Pasteur, Paris (France); Guérin, Diego M. A. [Unidad de Biofisica (CSIC-UPV/EHU), PO Box 644, E-48080 Bilbao (Spain); Grupo de Biofísica, Departamento de Física, Universidad Nacional del Sur, Bahía Blanca (Argentina)

    2006-10-01

    The X-ray structure of the tetragonal form of apo acyl-CoA-binding protein (ACBP) from the Harderian gland of the South American armadillo Chaetophractus villosus has been solved. The X-ray structure of the tetragonal form of apo acyl-CoA-binding protein (ACBP) from the Harderian gland of the South American armadillo Chaetophractus villosus has been solved. ACBP is a carrier for activated long-chain fatty acids and has been associated with many aspects of lipid metabolism. Its secondary structure is highly similar to that of the corresponding form of bovine ACBP and exhibits the unique flattened α-helical bundle (up–down–down–up) motif reported for animal, yeast and insect ACBPs. Conformational differences are located in loops and turns, although these structural differences do not suffice to account for features that could be related to the unusual biochemistry and lipid metabolism of the Harderian gland.

  15. Experimental and theoretical rearrangement of N-acyl-2,2-dimethylaziridines in acidic medium

    Madiha Kamoun Mhiri; Firas Aboumessaad; Mohamed Lotfi Efrit; Youssef Arfaoui; Néji Besbes

    2016-02-01

    The acid isomerization of N-acyl-2,2-dimethylaziridines 1 in concentrated sulfuric acid at room temperature leads to oxazolines 2 but the neutral hydrolysis of 1 in pure water at room temperature leads to amidoalcohols 3. However, the use of aqueous solutions of H2SO4 at different concentrations at room temperature leads to a mixture of oxazolines 2, amidoalcohols 3 and allylamides 4 with yields depending on the acidity of the medium and the nature of the acyl group. A mechanism has been suggested to explain the formation of these three products. DFT calculations employing the Gaussian 09 program with DFT/B3LYP methods and 6-311++G(2d,2p) basis set were carried out which gave the most stable geometry as well as their atomic charge distributions of compounds 1-4.

  16. Acyl migration evaluation in monoacylglycerols from Echium plantagineum seed oil and Marinol.

    Rincón Cervera, Miguel Ángel; Venegas Venegas, Elena; Ramos Bueno, Rebeca; Rodríguez García, Ignacio; Guil-Guerrero, José Luis

    2013-05-01

    Production of 2-monoacylglycerols (2-MAGs) by selective hydrolysis of the triacylglycerols (TAGs) of Echium plantagineum seed oil and Marinol and further purification was carried out. Three purification methods, including silica gel column chromatography, liquid-liquid extraction and low-temperature crystallization were assayed. Partial acyl migration during the purification step is always observed. Acyl migration rates were similar both for the column chromatography and for the liquid-liquid extraction methods, and resulted in 1-MAG/2-MAG ratios higher than 1.0. Fatty acid (FA) profiles of 2-MAGs after enzyme hydrolysis showed that the major FAs were stearidonic acid (56.9% of total FA in 2-position) and docosahexaenoic acid (63.6% of total FA in 2-position) for E. plantagineum seed oil and Marinol, respectively. PMID:23287502

  17. Regulation of lipolytic activity by long-chain acyl-coenzyme A in islets and adipocytes

    Hu, Liping; Deeney, Jude T; Nolan, Christopher J; Peyot, Marie-Line; Ao, Ada; Richard, Ann Marie; Luc, Esthere; Færgeman, Nils J.; Knudsen, Jens; Guo, Wen; Sorhede-Winzell, Maria; Prentki, Marc; Corkey, Barbara E

    2005-01-01

    -cells. The mechanisms by which lipolysis is regulated in different tissues is, therefore, of considerable interest. Here, the effects of long-chain acyl-CoA esters (LC-CoA) on lipase activity in islets and adipocytes were compared. Palmitoyl-CoA (Pal-CoA, 1-10 microM) stimulated lipase activity in islets...... adipocytes. The inhibitory effect of LC-CoA on adipocyte HSL was dependent on phosphorylation and enhanced by acyl-CoA-binding protein (ACBP). In contrast, the stimulatory effect on islet lipase activity was blocked by ACBP, presumably due to binding and sequestration of LC-CoA. These data suggest the...

  18. Novel endogenous N-acyl amides activate TRPV1-4 receptors, BV-2 microglia, and are regulated in brain in an acute model of inflammation

    Siham eRaboune

    2014-08-01

    Full Text Available A family of endogenous lipids, structurally analogous to the endogenous cannabinoid, N-arachidonoyl ethanolamine (Anandamide, and called N-acyl amides have emerged as a family of biologically active compounds at TRP receptors. N-acyl amides are constructed from an acyl group and an amine via an amide bond. This same structure can be modified by changing either the fatty acid or the amide to form potentially hundreds of lipids. More than 70 N-acyl amides have been identified in nature. We have ongoing studies aimed at isolating and characterizing additional members of the family of N-acyl amides in both central and peripheral tissues in mammalian systems. Here, using a unique in-house library of over 70 N-acyl amides we tested the following three hypotheses: 1 Additional N-acyl amides will have activity at TRPV1-4, 2 Acute peripheral injury will drive changes in CNS levels of N-acyl amides, and 3 N-acyl amides will regulate calcium in CNS-derived microglia. Through these studies, we have identified 20 novel N-acyl amides that collectively activate (stimulating or inhibiting TRPV1-4. Using lipid extraction and HPLC coupled to tandem mass spectrometry we showed that levels of at least 10 of these N-acyl amides that activate TRPVs are regulated in brain after intraplantar carrageenan injection. We then screened the BV2 microglial cell line for activity with this N-acyl amide library and found overlap with TRPV receptor activity as well as additional activators of calcium mobilization from these lipids. Together these data provide new insight into the family of N-acyl amides and their roles as signaling molecules at ion channels, in microglia, and in the brain in the context of inflammation.

  19. Cholesterol esterification by mouse liver homogenate. Contribution to the study of ACYL-CoA: Cholesterol ACYL transferase in mammalian liver

    A cholesterol- esterifying enzyme from mouse liver has been partially characterized. The enzyme which showed optimum activity at pH 7,1 and required ATP and CoA, was identified as an acyl CoA: cholesterol acyl transferase (E.C.2.3.1.26). As a fuction of time the percentage of esterified cholesterol increased linearly during the first hour of incubation and continued to increase but not linearly with 4 hours, after which time no further net esterefication was observed. The relative concentration of esterified cholesterol remained constant between the fourth and twelveth hours of incubation but afterwards decreased when the incubation continued until 24 hours. The cholesterol- esterifying activity was 24,0+- 2,9 nmoles cholesterol esterified per gram tissue wet weight per minute. The mean percentages of free cholesterol esterified in and 24 hours respectively were 14,8+- 1,6 e 21,9+- 4,5. The subfractionation of labelled cholesteryl esters after one hour incubation of liver homogenate with 4-C14-Cholesterol showed the order of preference for the formation of the different ester classes to be monounsatured > diunsatured ≥ saturated >> polyunsaturated. The properties of the enzyme frommouse liver do not markedly differ from those of the previously recorded ACAT activity of rat liver. (Author)

  20. Ruthenium(III Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids

    Mingzhong Cai

    2009-09-01

    Full Text Available Ruthenium(III chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]. The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent.

  1. NMR structure of an acyl-carrier protein from Borrelia burgdorferi

    Barnwal, Ravi P.; Van Voorhis, Wesley C.; Varani, G

    2011-01-01

    Nearly complete resonance assignment and the high-resolution NMR structure of the acyl-carrier protein from Borrelia burgdorferi, a target of the Seattle Structural Genomics Center for Infectious Disease (SSGCID) structure-determination pipeline, are reported. This protein was chosen as a potential target for drug-discovery efforts because of its involvement in fatty-acid biosynthesis, an essential metabolic pathway, in bacteria. It was possible to assign >98% of backbone resonances and >92% ...

  2. Pantoea sp. Isolated from Tropical Fresh Water Exhibiting N-Acyl Homoserine Lactone Production

    Wen-Si Tan; Nina Yusrina Muhamad Yunos; Pui-Wan Tan; Nur Izzati Mohamad; Tan-Guan-Sheng Adrian; Wai-Fong Yin; Kok-Gan Chan

    2014-01-01

    N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. ...

  3. Modulating plant hormones by enzyme action: The GH3 family of acyl acid amido synthetases

    Westfall, Corey S.; Herrmann, Jonathan; Chen, Qingfeng; Wang, Shiping; Jez, Joseph M.

    2010-01-01

    Plants respond to developmental cues and environmental stresses by controlling both the level and activity of various hormones. One mechanism of modulating hormone action involves amino acid conjugation. In plants, the GH3 family of enzymes conjugates various amino acids to jasmonates, auxins and benzoates. The effect of conjugation can lead to activation, inactivation or degradation of these molecules. Although the acyl acid and amino acid specificities of a few GH3 enzymes have been examine...

  4. A Scalable Method for Regioselective 3-Acylation of 2-Substituted lndoles under Basic Conditions

    Johansson, Henrik; Urruticoechea, Andoni; Larsen, Inna; Pedersen, Daniel Sejer

    2015-01-01

    Privileged structures such as 2-arylindoles are recurrent molecular scaffolds in bioactive molecules. We here present an operationally simple, high yielding and scalable method for regioselective 3-acylation of 2-substituted indoles under basic conditions using functionalized acid chlorides. The ...... method shows good tolerance to both electron-withdrawing and donating substituents on the indole scaffold and gives ready access to a variety of functionalized 3-acylindole building blocks suited for further derivatization....

  5. Identification and Characterization of Inhibitors of Bacterial Enoyl-Acyl Carrier Protein Reductase

    Ling, Losee L.; Xian, Jun; Ali, Syed; Geng, Bolin; Fan, Jun; Mills, Debra M.; Arvanites, Anthony C.; Orgueira, Hernan; Ashwell, Mark A.; Carmel, Gilles; Xiang, Yibin; Moir, Donald T.

    2004-01-01

    Bacterial enoyl-acyl carrier protein reductase (ENR) catalyzes an essential step in fatty acid biosynthesis. ENR is an attractive target for narrow-spectrum antibacterial drug discovery because of its essential role in metabolism and its sequence conservation across many bacterial species. In addition, the bacterial ENR sequence and structural organization are distinctly different from those of mammalian fatty acid biosynthesis enzymes. High-throughput screening to identify inhibitors of Esch...

  6. Rimonabant is a dual inhibitor of acyl CoA:cholesterol acyltransferases 1 and 2

    Netherland, Courtney; Thewke, Douglas P.

    2010-01-01

    Acyl-coenzymeA:cholesterol acyltransferase (ACAT) catalyzes the intracellular synthesis of cholesteryl esters (CE). Both ACAT isoforms, ACAT1 and ACAT2, play key roles in the pathophysiology of atherosclerosis and ACAT inhibition retards atherosclerosis in animal models. Rimonabant, a type 1 cannabinoid receptor (CB1) antagonist, produces anti-atherosclerotic effects in humans and animals by mechanisms which are not completely understood. Rimonabant is structurally similar to two other cannab...

  7. Ultraviolet stimulated melanogenesis by human melanocytes is augmented by di-acyl glycerol but not TPA

    Epidermal melanocytes (MC) synthesize melanin in response to ultraviolet radiation (UVR). The mechanisms mediating the UV-induced activation of melanogenesis are unknown but since UVR induces turnover of membrane phospholipids generating prostaglandins (PGs) and other products, it is possible that one of these might provide the activating signal. We have examined the effects of prostaglandins (PGs) E1, E2, D2, F2 alpha, and di-acyl glycerol upon the UV-induced responses of cultured human MC and the Cloudman S91 melanoma cell line. The PGs had little effect on unirradiated cells and did not alter the response to UVR in either human MC or S91 melanoma cells. However, a synthetic analogue of di-acyl glycerol, 1-oleyl 2-acetyl glycerol (OAG), caused a significant (P less than 0.0001), dose-related augmentation of melanin content both in human MC (seven-fold) and S91 cells (three-fold). UVR caused a significant augmentation of the OAG-induced melanogenesis of both human MC and S91 cells. Since OAG is known to activate protein kinase C, it was possible that the observed modulation of the UVR signal could be via that pathway. Di-octanoyl glycerol, another di-acyl glycerol, which activates kinase C, caused a small (70%) increase in melanogenesis in MC which was not altered by UVR. However, 12-0 tetradecanoyl phorbol 13-acetate (TPA), a potent activator of protein kinase C, had no significant effect on either basal or UV-induced melanin synthesis in either cell type. These data suggest that the UV-induced signal activating melanogenesis could be mediated by di-acyl glycerol. Furthermore, they imply that the signal is transduced via an alternative, pathway that might be independent of protein kinase C

  8. Reaction of /alpha/,/beta/-unsaturated acyl isothiocyanates with salts of dithiocarbamic acids

    Krus, K.; Masias, A.; Beletskaya, I.P.

    1989-01-10

    The reaction of unsaturated isothiocyanates with the sodium and calcium salts of N-alkyl- and N,N-dialkyldithiocarbamic acids was studied. Depending on the structure of the dithiocarbamate, the reaction products are thiazines or acyl dithiocarbamates. For the salts of methyldithiocarbamic acid the effect of the concentration and the nature of the metal on the relative yields of 6-phenyl-3-methylpropiorhodanine and 6-phenylpropiorhodanine was studied. A method is proposed for the synthesis of 3-substituted propiorhodanines.

  9. Changes in short-chain acyl-coA dehydrogenase during rat cardiac development and stress

    Huang, Jinxian; Xu, Lipeng; Huang, Qiuju; Luo, Jiani; Liu, Peiqing; Chen, Shaorui; Yuan, Xi; Lu, Yao; Wang, Ping; Zhou, Sigui

    2015-01-01

    This study was designed to investigate the expression of short-chain acyl-CoA dehydrogenase (SCAD), a key enzyme of fatty acid β-oxidation, during rat heart development and the difference of SCAD between pathological and physiological cardiac hypertrophy. The expression of SCAD was lowest in the foetal and neonatal heart, which had time-dependent increase during normal heart development. In contrast, a significant decrease in SCAD expression was observed in different ages of spontaneously hyp...

  10. Acyl homoserine lactone-based quorum sensing in a methanogenic archaeon

    Zhang, Guishan; Zhang, Fan; Ding, Gang; Li, Jie; Guo, Xiaopeng; Zhu, Jinxing; Zhou, Liguang; Cai, Shichun; Liu, Xiaoli; Luo, Yuanming; Zhang, Guifeng; Shi, Wenyuan; Dong, Xiuzhu

    2012-01-01

    Acyl homoserine lactone (AHL)-based quorum sensing commonly refers to cell density-dependent regulatory mechanisms found in bacteria. However, beyond bacteria, this cell-to-cell communication mechanism is poorly understood. Here we show that a methanogenic archaeon, Methanosaeta harundinacea 6Ac, encodes an active quorum sensing system that is used to regulate cell assembly and carbon metabolic flux. The methanogen 6Ac showed a cell density-dependent physiology transition, which was related t...

  11. Ruthenium(III) Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids

    Mingzhong Cai; Pingping Wang; Wenyan Hao; Zhiwen Xi

    2009-01-01

    Ruthenium(III) chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]). The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent.

  12. Engineering acyl carrier protein to enhance production of shortened fatty acids

    Liu, Xueliang; Hicks, Wade M.; Silver, Pamela A.; Way, Jeffrey C

    2016-01-01

    Background The acyl carrier protein (ACP) is an essential and ubiquitous component of microbial synthesis of fatty acids, the natural precursor to biofuels. Natural fatty acids usually contain long chains of 16 or more carbon atoms. Shorter carbon chains, with increased fuel volatility, are desired for internal combustion engines. Engineering the length specificity of key proteins in fatty acid metabolism, such as ACP, may enable microbial synthesis of these shorter chain fatty acids. Results...

  13. Prolonged QTc Interval in Association With Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

    Wiles, Jason R.; Leslie, Nancy; Knilans, Timothy K.; Akinbi, Henry

    2014-01-01

    Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is the most common disorder of mitochondrial fatty acid oxidation. We report a term male infant who presented at 3 days of age with hypoglycemia, compensated metabolic acidosis, hypocalcemia, and prolonged QTc interval. Pregnancy was complicated by maternal premature atrial contractions and premature ventricular contractions. Prolongation of the QTc interval resolved after correction of metabolic derangements. The newborn screen was...

  14. Radical Behaviorism and Buddhism: Complementarities and Conflicts

    Diller, James W.; Lattal, Kennon A.

    2008-01-01

    Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their…

  15. Radical-Local Teaching and Learning

    Hedegaard, Mariane; Chaiklin, Seth

    radical-local teaching and learning approach. The first half of the book introduces the idea of radical-local teaching and learning and develops the theoretical background for this perspective, drawing on the cultural-historical research tradition, particularly from Vygotsky, El'konin, Davydov...

  16. What Is Radical in School Geography Today?

    Morgan, John

    2011-01-01

    This article addresses the question of what "radical school geography" might look like in the present historical moment. It traces the history of a distinctive "radical" tradition in school geography, most prominently associated with the work of John Huckle, who argued for the importance of understanding the content and pedagogy of school…

  17. Free Radical Mechanisms in Autoxidation Processes.

    Simic, Michael G.

    1981-01-01

    Discusses the use of steady-state radiation chemistry and pulse radiolysis for the generation of initial free radicals and formation of peroxy radicals in the autoxidation process. Provides information regarding the autoxidation process. Defines autoxidation reactions and antioxidant action. (CS)

  18. Purification of specific structured lipids by distillation: Effects on acyl migration

    Xu, Xuebing; Skands, A.; Adler-Nissen, Jens

    2001-01-01

    The cause and effects of acyl migration during the purification of specific structured lipids by distillation were studied in a conventional batch deodorizer with stripping steam. The mixture of specific structured lipids produced by lipase-catalyzed acidolysis between rapeseed oil and capric aci...... possible with more effective pumps. To reduce the distillation time, thin-film principle in a packed column should be used, or other more efficient distillation techniques such as molecular distillation or short-path distillation should be exploited.......The cause and effects of acyl migration during the purification of specific structured lipids by distillation were studied in a conventional batch deodorizer with stripping steam. The mixture of specific structured lipids produced by lipase-catalyzed acidolysis between rapeseed oil and capric acid...... contained a large amount of free fatty acids and a small amount of partial acylglycerols besides triacylglycerols. Therefore, the effect of steam, free fatty acids, diacylglycerols, and monoacylglycerols on acyl migration was studied in a palm oil midfraction model. The results showed that all these factors...

  19. Endophytic Actinomycetes: A Novel Source of Potential Acyl Homoserine Lactone Degrading Enzymes

    Surang Chankhamhaengdecha

    2013-01-01

    Full Text Available Several Gram-negative pathogenic bacteria employ N-acyl-L-homoserine lactone (HSL quorum sensing (QS system to control their virulence traits. Degradation of acyl-HSL signal molecules by quorum quenching enzyme (QQE results in a loss of pathogenicity in QS-dependent organisms. The QQE activity of actinomycetes in rhizospheric soil and inside plant tissue was explored in order to obtain novel strains with high HSL-degrading activity. Among 344 rhizospheric and 132 endophytic isolates, 127 (36.9% and 68 (51.5% of them, respectively, possessed the QQE activity. The highest HSL-degrading activity was at 151.30±3.1 nmole/h/mL from an endophytic actinomycetes isolate, LPC029. The isolate was identified as Streptomyces based on 16S  rRNA gene sequence similarity. The QQE from LPC029 revealed HSL-acylase activity that was able to cleave an amide bond of acyl-side chain in HSL substrate as determined by HPLC. LPC029 HSL-acylase showed broad substrate specificity from C6- to C12-HSL in which C10HSL is the most favorable substrate for this enzyme. In an in vitro pathogenicity assay, the partially purified HSL-acylase efficiently suppressed soft rot of potato caused by Pectobacterium carotovorum ssp. carotovorum as demonstrated. To our knowledge, this is the first report of HSL-acylase activity derived from an endophytic Streptomyces.

  20. Role of acyl carrier protein isoforms in plant lipid metabolism: Progress report

    Ohlrogge, J.B.

    1989-01-01

    Previous research from my lab has revealed that several higher plant species have multiple isoforms of acyl carrier protein (ACP) and therefore this trait appears highly conserved among higher plants. This level of conservation suggests that the existence of ACP isoforms is not merely the results of neutral gene duplications. We have developed techniques to examine a wider range of species. Acyl carrier proteins can be labelled very specifically and to high specific activity using H-palmitate and the E. coli enzyme acyl-ACP synthetase. Isoforms were then resolved by western blotting and native PAGE of H-palmitate labelled ACP's. Multiple isoforms of ACP were observed the leaf tissue of the monocots Avena sativa and Hordeum vulgare and dicots including Arabidopsis thallina, Cuphea wrightii, and Brassica napus. Lower vascular plants including the cycad, Dioon edule, Ginkgo biloba, the gymnosperm Pinus, the fern Anernia phyllitidis and Psilotum nudum, the most primitive known extant vascular plant, were also found to have multiple ACP isoforms as were the nonvascular liverwort, Marchantia and moss, Polytrichum. Therefore, the development of ACP isoforms occurred early in evolution. However, the uniellular alge Chlamydomonas and Dunaliella and the photosynthetic cyanobacteria Synechocystis and Agmnellum have only a single elecrophotetic form of ACP. Thus, multiple forms of ACP do not occur in all photosynthetic organisms but may be associated with multicellular plants.

  1. Poly specific trans-acyltransferase machinery revealed via engineered acyl-CoA synthetases.

    Koryakina, Irina; McArthur, John; Randall, Shan; Draelos, Matthew M; Musiol, Ewa M; Muddiman, David C; Weber, Tilmann; Williams, Gavin J

    2013-01-18

    Polyketide synthases construct polyketides with diverse structures and biological activities via the condensation of extender units and acyl thioesters. Although a growing body of evidence suggests that polyketide synthases might be tolerant to non-natural extender units, in vitro and in vivo studies aimed at probing and utilizing polyketide synthase specificity are severely limited to only a small number of extender units, owing to the lack of synthetic routes to a broad variety of acyl-CoA extender units. Here, we report the construction of promiscuous malonyl-CoA synthetase variants that can be used to synthesize a broad range of malonyl-CoA extender units substituted at the C2-position, several of which contain handles for chemoselective ligation and are not found in natural biosynthetic systems. We highlighted utility of these enzymes by probing the acyl-CoA specificity of several trans-acyltransferases, leading to the unprecedented discovery of poly specificity toward non-natural extender units, several of which are not found in naturally occurring biosynthetic pathways. These results reveal that polyketide biosynthetic machinery might be more tolerant to non-natural substrates than previously established, and that mutant synthetases are valuable tools for probing the specificity of biosynthetic machinery. Our data suggest new synthetic biology strategies for harnessing this promiscuity and enabling the regioselective modification of polyketides. PMID:23083014

  2. Inhibition of DNA-Topoisomerase I by Acylated Triterpene Saponins from Pittosporum angustifolium Lodd.

    Bäcker, Christian; Drwal, Malgorzata N; Preissner, Robert; Lindequist, Ulrike

    2016-04-01

    Previous phytochemical investigation of the leaves and seeds of Pittosporum angustifolium Lodd. led to the isolation and structural elucidation of polyphenols and triterpene saponins. Evaluation for cytotoxicity of isolated saponins revealed that the predominant structural feature for a cytotoxic activity are acyl substituents at the oleanane aglycon backbone. The present work reports the results of a screening of 10 selected acylated saponins for their potential to inhibit the human DNA-topoisomerase I, giving rise to IC50 values in a range of 2.8-46.5 µM. To clarify the mode of observed cytotoxic action and, moreover, to distinguish from a pure surfactant effect which is commonly accompanied with saponins, these results indicate an involvement of the topoisomerase I and its role as a possible target structure for a cytotoxic activity. In addition, computational predictions of the fitting of saponins to the topoisomerase I-DNA complex, indicate a similar binding mode to that of clinically used topoisomerase I inhibitors. Ten acylated triterpene saponins from Pittosporum angustifolium were investigated for their potential to inhibit the human DNA-topoisomerase I and computational predictions of the fitting of saponins to the topoisomerase I-DNA complex were carried out. PMID:26803837

  3. Cloning of a palmitoyl-acyl carrier protein thioesterase from oil palm.

    Othman, A; Lazarus, C; Fraser, T; Stobart, K

    2000-12-01

    A palmitoyl-acyl carrier protein (ACP) thioesterase cDNA clone was isolated from an oil palm cDNA library. The cDNA was expressed in Escherichia coli as a glutathione S-transferase fusion protein and a crude bacterial extract was assayed for acyl-CoA-hydrolysing activity. The recombinant enzyme was able to hydrolyse medium- and long-chain acyl-CoAs. Northern-blot analysis showed a high level of gene expression in leaf, flower and 15-, 17- and 18-week mesocarp tissues. Low-level gene expression was detected in germinated seedlings and 8- and 12-week mesocarp tissues, but no transcript was detected in any kernel tissues. Southern-blot analysis indicated the presence of a single gene and we have also isolated a genomic clone using the cDNA as a probe. Two genomic fragments were subcloned and a 7 kb contiguous stretch of the oil palm genome was sequenced. Comparison of this sequence with the cDNA sequence identified a putative 93 amino acid transit peptide, most of which is missing from the cDNA. The coding region of the gene consisted of seven exons and six introns. PMID:11171146

  4. Acyl Chain Disorder and Azelaoyl Orientation in Lipid Membranes Containing Oxidized Lipids.

    Mendes Ferreira, Tiago; Sood, Rohit; Bärenwald, Ruth; Carlström, Göran; Topgaard, Daniel; Saalwächter, Kay; Kinnunen, Paavo K J; Ollila, O H Samuli

    2016-06-28

    Oxidized phospholipids occur naturally in conditions of oxidative stress and have been suggested to play an important role in a number of pathological conditions due to their effects on a lipid membrane acyl chain orientation, ordering, and permeability. Here we investigate the effect of the oxidized phospholipid 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC) on a model membrane of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) using a combination of (13)C-(1)H dipolar-recoupling nuclear magnetic resonance (NMR) experiments and united-atom molecular dynamics (MD) simulations. The obtained experimental order parameter SCH profiles show that the presence of 30 mol % PazePC in the bilayer significantly increases the gauche content of the POPC acyl chains, therefore decreasing the thickness of the bilayer, although with no stable bilayer pore formation. The MD simulations reproduce the disordering effect and indicate that the orientation of the azelaoyl chain is highly dependent on its protonation state with acyl chain reversal for fully deprotonated states and a parallel orientation along the interfacial plane for fully protonated states, deprotonated and protonated azelaoyl chains having negative and positive SCH profiles, respectively. Only fully or nearly fully protonated azelaoyl chain are observed in the (13)C-(1)H dipolar-recoupling NMR experiments. The experiments show positive SCH values for the azelaoyl segments confirming for the first time that oxidized chains with polar termini adopt a parallel orientation to the bilayer plane as predicted in MD simulations. PMID:27260273

  5. Physicochemical aspects of isomerisation of free radicals

    Denisov, Evgenii T; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2004-11-30

    Kinetic data on intramolecular abstraction of hydrogen atoms in alkyl, alkoxyl and peroxyl radicals are generalised and analysed. It is shown that the activation energies of these reactions are affected by ring strain. The kinetic parameters of mono- and bimolecular elimination reactions are compared. The difference between the activation energies of these reactions is interpreted using the model of intersecting parabolas. The same model is used to discuss the results of analysis of cyclisation of alkyl radicals; the ring strain energy is shown to play an important role in the activation of these reactions. It is noted that the difference between the electron affinities of the C, N and O atoms is clearly manifested in the cyclisation of aminyl and {omega}-formylalkyl radicals. The kinetic parameters of cyclisation and bimolecular radical addition reactions are compared. The experimental data on the transfer of the vinyl and aryl groups in alkyl radicals are analysed.

  6. Hydroxyl-radical-induced oxidation of cyclic dipeptides: Reactions of free peptide radicals and their peroxyl radicals

    In the course of this study investigations were carried out into the reactions of hydroxyl radicals and hydrogen atoms with cyclic dipeptides as well as the subsequent reactions of peptide radicals and their peroxyl radicals in aqueous solution. The radiolysis products formed in the absence and presence of oxygen or transient metal complexes were characterized and determined on a quantitative basis. The linking of information from product analyses to the kinetic data for transient species obtained by time-resolving UV/VIS and conductivity measurements (pulse radiolysis) as well as computer-assisted simulations of individual events during the reaction permitted an evaluation of the mechanisms underlying the various processes and an identification of interim products with short life-times, which did or did not belong to the group of radicals. Through the characterization of key reactions of radicals and peroxyl radicals of this substance class a major advance has been made towards a better understanding of the role of radicals in the peptide compound and the mechanisms involved in indirect radiation effects on long-chain peptides and proteins. (orig.)

  7. Concentrations of long-chain acyl-acyl carrier proteins during fatty acid synthesis by chloroplasts isolated from pea (Pisum sativum), safflower (Carthamus tinctoris), and amaranthus (Amaranthus lividus) leaves

    Fatty acid synthesis from [1-14C]acetate by chloroplasts isolated from peas and amaranthus was linear for at least 15 min, whereas incorporation of the tracer into long-chain acyl-acyl carrier protein (ACP) did not increase after 2-3 min. When reactions were transferred to the dark after 3-5 min, long-chain acyl-ACPs lost about 90% of their radioactivity and total fatty acids retained all of theirs. Half-lives of the long-chain acyl-ACPs were estimated to be 10-15 s. Concentrations of palmitoyl-, stearoyl-, and oleoyl-ACP as indicated by equilibrium labeling during steady-state fatty acid synthesis, ranged from 0.6-1.1, 0.2-0.7, and 0.4-1.6 microM, respectively, for peas and from 1.6-1.9, 1.3-2.6, and 0.6-1.4 microM, respectively, for amaranthus. These values are based on a chloroplast volume of 47 microliters/mg chlorophyll and varied according to the mode of the incubation. A slow increase in activity of the fatty acid synthetase in safflower chloroplasts resulted in long-chain acyl-ACPs continuing to incorporate labeled acetate for 10 min. Upon re-illumination following a dark break, however, both fatty acid synthetase activity and acyl-ACP concentrations increased very rapidly. Palmitoyl-ACP was present at concentrations up to 2.5 microM in safflower chloroplasts, whereas those of stearoyl- and oleoyl-ACPs were in the lower ranges measured for peas. Acyl-ACPs were routinely separated from extracts of chloroplasts that had been synthesising long-chain fatty acids from labeled acetate by a minor modification of the method of Mancha et al. The results compared favorably with those obtained using alternative analytical methods such as adsorption to filter paper and partition chromatography on silicic acid columns

  8. ORGASMIC FUNCTION AFTER RADICAL PROSTATECTOMY

    D. Yu. Pushkar

    2014-07-01

    Full Text Available Objective: to study orgasmic function (OF in patients undergoing radical prostatectomy (RPE.Subjects and methods. Seventy-nine patients who had undergone RPE for locally advanced prostate cancer without hormone and radiation therapies were examined. The patients’ mean age was 59.3 years. The mean EF-IIEF domain score was 24.4. OF was estimated by IIEF question 10 and the authors’ questionnaire. The Spearman rank correction coefficient and Mann-Whitney U-Wilcoxon tests were used.Results. After RPE, there was a reduction in the mean IIEF question 10 score from 3.9 (confidence interval 3.7–4.1 to 3.3 (3–3.5 (p = 0.000. The following changes were found in orgasm intensity: no changes in 43 %, mild worsening in 42 %, severe worsening in 8 %, and enhancement in 4 %; orgasm could not be achieved in 4 % of the patients. Pain usually of low intensity was reported by 8.8 %. The poor factors for preserving OF were its low baseline level, elderly age, or severe post-RPE erectile dysfunction.Conclusion. There were significant OF changes after RPE, which should be kept in mind while treating this category of patients.

  9. Possible role for growth hormone in suppressing acylated ghrelin and hunger ratings during and after intermittent exercise of different intensities in obese individuals.

    Majid Gholipour; Mohamad Reza Kordi; Mohamad Taghikhani; Ali Asghar Ravasi; Abas Ali Gaeini; Arezoo Tabrizi

    2014-01-01

    Body weight is influenced by both food intake and energy expenditure. Acylated ghrelin enhances appetite, and its circulating level is suppressed by growth hormone. Data on the acylated ghrelin responses to exercise of different intensities in obese individuals are currently not available. This study examined the effects of an intermittent exercise protocol on acylated ghrelin levels and hunger ratings in obese people. Nine inactive male ran on the treadmill at 0900 with progressive intensiti...

  10. Generation of radicals by bimolecular reactions

    Denisov, Evgenii T; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2002-05-31

    The published data on bimolecular processes of radical generation in chain degradation, polymerisation, oxidation and halogenation reactions of organic compounds are systematised and analysed within the framework of the parabolic model of homolytic bimolecular reactions. The specific features of these highly endothermic reactions are discussed with a special emphasis on their striking similarity to radical abstraction processes with identical reaction centres in the transition state. The feasibility of theoretical evaluation of the activation energies and the rate constants of bimolecular reactions in radical generation is demonstrated. The bibliography includes 86 references.

  11. Efficient production of di- and tri-acylated mannosylerythritol lipids as glycolipid biosurfactants by Pseudozyma parantarctica JCM 11752(T).

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipids (MELs) are one of the most promising biosurfactants known, because of their multifunctionality and biocompatibility. In order to attain an efficient production of MELs, Pseudozyma parantarctica JCM 11752(T), which is a newly identified strain of the genus, was examined for the productivity of MELs at different culture conditions. The yeast strain showed significant cell growth and production of di-acylated MELs even at 36 degrees C. In contrast, on conventional high-level MEL producers including P. rugulosa, the MEL yield considerably decreased with an increase of the cultivation temperature at over 30 degrees C. On P. parantarctica, soybean oil and sodium nitrate were the best carbon and nitrogen sources, respectively. Under the optimal conditions on a shake-flask culture at 34 degrees C, the amount of di-acylated MELs reached over 100 g/L by intermittent feeding of only soybean oil. Interestingly, the yeast strain produced tri-acylated MELs as well as di-acylated ones when grown on the medium containing higher soybean oil concentrations than 8% (vol/vol). The production of tri-acylated MELs was significantly accelerated at between 34 and 36 degrees C. With 20 % (vol/vol) of soybean oil at 34 degrees C, the yield of tri-acylated MELs reached 22.7 g/L. The extracellular lipase activity considerably depended on the culture temperature, and became the maximum at 34 degrees C; this would bring the accelerated production of tri-acylated MELs. Accordingly, the present strain of P. parantarctica provided high efficiency in MEL production at elevated temperatures compared to conventional MEL producers, and would thus be highly advantageous for the commercial production of the promising biosurfactants. PMID:18781056

  12. Majority of cellular fatty acid acylated proteins are localized to the cytoplasmic surface of the plasma membrane

    The BC2Hl muscle cell line was previously reported to contain a broad array of fatty acid acylated proteins. Palmitate was shown to be attached to membrane proteins posttranslationally through thiol ester linkages, whereas myristate was attached cotranslationally, or within seconds thereafter, to soluble and membrane-bound proteins through amide linkages. The temporal and subcellular differences between palmitate and myristate acylation suggested that these two classes of acyl proteins might follow different intracellular pathways to distinct subcellular membrane systems or organelles. In this study, the authors examined the subcellular localization of the major fatty acylated proteins in BC4Hl cells. Palmitate-containing proteins were localized to the plasma membrane, but only a subset of myristate-containing proteins was localized to this membrane fraction. The majority of acyl proteins were nonglycosylated and resistant to digestion with extracellular proteases, suggesting that they were not exposed to the external surface of the plasma membrane. Many proteins were, however, digested during incubation of isolated membranes with proteases, which indicates that these proteins were, however, digested during incubation of isolated membranes with proteases, which indicates that these proteins face the cytoplasm. Two-dimensional gel electrophoresis of proteins labeled with [3H]palmitate and [3H]myristate revealed that individual proteins were modified by only one of the two fatty acids and did not undergo both N-linked myristylation and ester-linked palmitylation. Together, these results suggest that the majority of cellular acyl proteins are routed to the cytoplasmic surface of the plasma membrane, and they raise the possibility that fatty acid acylation may play a role in intracellular sorting of nontransmembranous, nonglycosylated membrane proteins

  13. Characterization of soluble acyl-ACP desaturases from Camelina sativa, Macadamia tetraphylla and Dolichandra unguis-cati.

    Rodríguez, Manuel Fernando Rodríguez; Sánchez-García, Alicia; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2015-04-15

    Acyl-acyl carrier protein (ACP) desaturases (EC 1.14.19.2) are soluble enzymes that catalyse the insertion of a double bond into saturated fatty acid bound in saturated acyl chains bound to ACP in higher plants, producing cis-monounsaturated fatty acids. Three types of soluble acyl-ACP desaturases have been described: Δ(9)-acyl-ACP, Δ(6)-acyl-ACP and Δ(4)-acyl-ACP desaturases, which differ in the substrate specificity and the position in which the double bond is introduced. In the present work, Camelina sativa (CsSAD), Macadamia tetraphylla (MtSAD) and Dolichandra unguis-cati (DuSAD) desaturases were cloned, sequenced and characterized. Single copies of CsSAD, MtSAD and DuSAD with three, one and two different alleles, respectively, were found. The corresponding mature proteins were heterologously expressed in Escherichia coli for biochemical characterization in protein extracts. The recombinant CsSAD enzyme showed 300-fold higher specificity towards 18:0-ACP than 16:0-ACP. Similar profile exhibited MtSAD although the differences in the specificity were lower, around 170-fold higher for 18:0-ACP than 16:0-ACP. Furthermore, DuSAD presented a profile showing preference towards 16:0-ACP against 18:0-ACP, around twice more, being so a Δ(9) palmitoyl-ACP desaturase. Also, we reported the expression profile of CsSAD, which showed the highest levels of expression in expanding tissues that typically are very active in lipid biosynthesis such as developing seed endosperm. Moreover, the possibility to express a new desaturase in C. sativa (oilseed crop that store high levels of oil and is easy to transform) to create a new line rich in short monounsaturated fatty acid is discussed. PMID:25765361

  14. A Simple, Rapid and Mild One Pot Synthesis of Benzene Ring Acylated and Demethylated Analogues of Harmine under Solvent-free Conditions

    Siddiqui, Bina S.; Syed Imran Hassan; Farhat Farhat; Syed Nawazish Ali; Sabira Begum

    2008-01-01

    A simple, rapid, solvent-free, room temperature one pot synthesis of benzene ring acylated and demethylated analogues of harmine using acyl halides/acid anhydrides and AlCl3 has been developed. Eight different acyl halides/acid anhydrides were used in the synthesis. The resulting mixture of products was separated by column chromatography to afford 10- and 12-monoacyl analogues, along with 10,12-diacyl-11-hydroxy products. In five cases the corresponding 10-acyl-11-hydroxy analogues were also ...

  15. A Simple, Rapid and Mild One Pot Synthesis of Benzene Ring Acylated and Demethylated Analogues of Harmine under Solvent-free Conditions

    Bina S. Siddiqui

    2008-08-01

    Full Text Available A simple, rapid, solvent-free, room temperature one pot synthesis of benzene ring acylated and demethylated analogues of harmine using acyl halides/acid anhydrides and AlCl3 has been developed. Eight different acyl halides/acid anhydrides were used in the synthesis. The resulting mixture of products was separated by column chromatography to afford 10- and 12-monoacyl analogues, along with 10,12-diacyl-11-hydroxy products. In five cases the corresponding 10-acyl-11-hydroxy analogues were also obtained. Yields from the eight syntheses (29 products in total were in the 6-34% range and all compounds were fully characterized.

  16. Preparation of Polybutylene Oxides Bearing Terminal Ester Groups by Treatment of H[(CH_2)_4O]_nSiR_3 with Acyl Halides

    Iura, Takafumi; Matsubara, Kouki; Nagashima,Hideo

    2000-01-01

    Treatment of H[(CH_2)_4O]_nSiR_3, which were prepared by the silane induced polymerization of THF with acyl halides catalyzed by (μ_3:η^2:η^3:η^5-acenaphthylene)Ru_3(CO)_7, provides a novel synthetic method for polybutylene oxides bearing terminal ester groups. Various acyl halides such as acetyl chloride, benzoyl bromide, adipoyl chloride, acryloyl chloride, and 2-bromoisobutyryl bromide could be used as the acyl halide component; the reactivity of acyl halides increased in the order RCOBr>R...

  17. Proteomic Analysis of a Poplar Cell Suspension Culture Suggests a Major Role of Protein S-Acylation in Diverse Cellular Processes.

    Srivastava, Vaibhav; Weber, Joseph R; Malm, Erik; Fouke, Bruce W; Bulone, Vincent

    2016-01-01

    S-acylation is a reversible post-translational modification of proteins known to be involved in membrane targeting, subcellular trafficking, and the determination of a great variety of functional properties of proteins. The aim of this work was to identify S-acylated proteins in poplar. The use of an acyl-biotin exchange method and mass spectrometry allowed the identification of around 450 S-acylated proteins, which were subdivided into three major groups of proteins involved in transport, signal transduction, and response to stress, respectively. The largest group of S-acylated proteins was the protein kinase superfamily. Soluble N-ethylmaleimide-sensitive factor-activating protein receptors, band 7 family proteins and tetraspanins, all primarily related to intracellular trafficking, were also identified. In addition, cell wall related proteins, including cellulose synthases and other glucan synthases, were found to be S-acylated. Twenty four of the identified S-acylated proteins were also enriched in detergent-resistant membrane microdomains, suggesting S-acylation plays a key role in the localization of proteins to specialized plasma membrane subdomains. This dataset promises to enhance our current understanding of the various functions of S-acylated proteins in plants. PMID:27148305

  18. Some reactions of oxidizing radicals with enzymes in aqueous solution

    A range of oxidizing radicals including some inorganic radical anions and the superoxide radical, can be generated by radiolysis of aqueous solutions. These radicals are more selective in their reactions with amino acids than the hydroxyl radical. Factors controlling the apparent reactivity of radical anions with proteins, such as free radical equilibria and ion-binding, are described. The superoxide radical inactivates papain by reaction with the cysteine residue. This reaction has been studied in solutions subjected to radiations of varying linear energy transfer. (Auth.)

  19. Radical pancreaticoduodenectomy for benign disease.

    Kavanagh, D O

    2008-01-01

    Whipple\\'s procedure is the treatment of choice for pancreatic and periampullary malignancies. Preoperative histological confirmation of malignancy is frequently unavailable and some patients will subsequently be found to have benign disease. Here, we review our experience with Whipple\\'s procedure for patients ultimately proven to have benign disease. The medical records of all patients who underwent Whipple\\'s procedure during a 15-year period (1987-2002) were reviewed; 112 patients underwent the procedure for suspected malignancy. In eight cases, the final histology was benign (7.1%). One additional patient was known to have benign disease at resection. The mean age was 50 years (range: 30-75). The major presenting features included jaundice (five), pain (two), gastric outlet obstruction (one), and recurrent gastrointestinal haemorrhage (one). Investigations included ultrasound (eight), computerised tomography (eight), endoscopic retrograde cholangiopancreatography (seven; of these, four patients had a stent inserted and three patients had sampling for cytology), and endoscopic ultrasound (two). The pathological diagnosis included benign biliary stricture (two), chronic pancreatitis (two), choledochal cyst (one), inflammatory pseudotumour (one), cystic duodenal wall dysplasia (one), duodenal angiodysplasia (one), and granular cell neoplasm (one). There was no operative mortality. Morbidity included intra-abdominal collection (one), anastomotic leak (one), liver abscess (one), and myocardial infarction (one). All patients remain alive and well at mean follow-up of 41 months. Despite recent advances in diagnostic imaging, 8% of the patients undergoing Whipple\\'s procedure had benign disease. A range of unusual pathological entities can mimic malignancy. Accurate preoperative histological diagnosis may have allowed a less radical operation to be performed. Endoscopic ultrasound-guided fine needle aspirate (EUS-FNA) may reduce the need for Whipple\\'s operation

  20. Radical Pancreaticoduodenectomy for Benign Disease

    D. O. Kavanagh

    2008-01-01

    Full Text Available Whipple's procedure is the treatment of choice for pancreatic and periampullary malignancies. Preoperative histological confirmation of malignancy is frequently unavailable and some patients will subsequently be found to have benign disease. Here, we review our experience with Whipple's procedure for patients ultimately proven to have benign disease. The medical records of all patients who underwent Whipple's procedure during a 15-year period (1987–2002 were reviewed; 112 patients underwent the procedure for suspected malignancy. In eight cases, the final histology was benign (7.1%. One additional patient was known to have benign disease at resection. The mean age was 50 years (range: 30–75. The major presenting features included jaundice (five, pain (two, gastric outlet obstruction (one, and recurrent gastrointestinal haemorrhage (one. Investigations included ultrasound (eight, computerised tomography (eight, endoscopic retrograde cholangiopancreatography (seven; of these, four patients had a stent inserted and three patients had sampling for cytology, and endoscopic ultrasound (two. The pathological diagnosis included benign biliary stricture (two, chronic pancreatitis (two, choledochal cyst (one, inflammatory pseudotumour (one, cystic duodenal wall dysplasia (one, duodenal angiodysplasia (one, and granular cell neoplasm (one. There was no operative mortality. Morbidity included intra-abdominal collection (one, anastomotic leak (one, liver abscess (one, and myocardial infarction (one. All patients remain alive and well at mean follow-up of 41 months. Despite recent advances in diagnostic imaging, 8% of the patients undergoing Whipple'’s procedure had benign disease. A range of unusual pathological entities can mimic malignancy. Accurate preoperative histological diagnosis may have allowed a less radical operation to be performed. Endoscopic ultrasound–guided fine needle aspirate (EUS-FNA may reduce the need for Whipple's operation in

  1. Biosynthesis of lipid a precursors: cloning, expression and partial purification of E. coli UDP-GlcNAc acyl transferase; identification of UDP-3-O-acyl-GlcNAc as its enzymatic product

    The initial steps in the biosynthesis of E. coli lipid A disaccharides have been shown to proceed by two acylations of UDP-GlcNAc to form UDP-2,3-diacyl-GlcN (UDP-DAG). In vitro synthesis of UDP-DAG appears to involve a previously undescribed, monoacylated form of UDP-GlcNAc. The authors now show (1) definitive evidence that this metabolite has the structure UDP-3-O-acyl-GlcNAc, and (2) that a gene encoding or controlling this acylating enzyme is located on a 2.4 Kb fragment mapping between dnaE and cds on the E. coli chromosome. Insertion of this fragment into an expression vector directs overproduction of an enzyme catalyzing monoacylation of UDP-GlcNAc by acyl-acyl carrier protein. The activity was partially purified from an overproducing strain by chromatography of the soluble fraction of a cell extract on DEAE cellulose in the presence of 1% octyl glucoside. Peak fractions were 2200x purified relative to wild type with an 80% yield. The product generated by this enzyme was isolated from a preparative scale incubation and structurally identified by 1H-NMR

  2. Lipase-catalyzed acyl exchange of soybean phosphatidylcholine in n-hexane: a critical evaluation of both acyl incorporation and product recovery

    Vikbjerg, Anders Falk; Mu, Huiling; Xu, Xuebing

    2005-01-01

    relationships on the incorporation of caprylic acid and the corresponding recovery of PC. Incorporation of fatty acids increased with increasing enzyme dosage, reaction temperature, solvent amount, reaction time and substrate ratio. Enzyme dosage had the most significant effect on the incorporation followed by...... the issue and optimization of the system is essential for the practical applications in reality. The effects of enzyme dosage, reaction temperature, solvent amount, reaction time, and substrate ratio were optimized in terms of the acyl incorporation, which led to the products, and lyso...... reaction time, reaction temperature, solvent amount and substrate ratio. However the parameters had also a negative influence on the PC recovery. Solvent amount had the most negative effect on recovery followed by enzyme dosage, temperature, and reaction time. Individually substrate ratio had no...

  3. ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 Are Responsible for Making Omega-7 Fatty Acids in the Arabidopsis Aleurone.

    Bryant, Fiona M; Munoz-Azcarate, Olaya; Kelly, Amélie A; Beaudoin, Frédéric; Kurup, Smita; Eastmond, Peter J

    2016-09-01

    Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3 We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ(9) desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3 Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ(9) desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids. PMID:27462083

  4. User involvement competence for radical innovation

    Lettl, Christopher

    One important market related capability for firms which seek to develop radical innovations is the competence to involve the 'right' users at the 'right' time in the 'right' form. While former studies have identified a rather passive role of users in the radical innovation process, this paper...... focuses on the involvement of such users that are in the position to play an active role as inventors and (co)-developers. A multiple case study analysis was conducted in the field of medical technology. Five radical innovation projects within four firms were selected including medical robots and computer......-assisted navigation systems. The case study analysis reveals that firms who closely interact with specific users benefit significantly for their radical innovation work. These users have a high motivation toward new solutions, are open to new technologies, possess diverse competencies, and are embedded into a very...

  5. Radicalization and the Use of Social Media

    Robin Thompson

    2011-01-01

    Full Text Available The use of social media tools by individuals and organizations to radicalize individuals for political and social change has become increasingly popular as the Internet penetrates more of the world and mobile computing devices are more accessible. To establish a construct for radicalization,the power and reach of social media will be described so there is common understanding of what social media is and how it is utilized by various individuals and groups. The second section will answer the question of why social media applications are the perfect platform for the radical voice. Finally, the use of social media and its influence in radicalizing populations in Northern Africa and the Middle East during 2011 will be analyzed and recommendations proposed.

  6. Neo-liberal Governing of 'Radicals'

    Lindekilde, Lasse

    2012-01-01

    The Danish government’s counter-radicalization Action Plan of 2009 had intended and unintended effects. Primarily targeting Danish Muslims, it employs neoliberal governmentality approaches of governance through individual support and response, information and knowledge, empowerment, surveillance ...

  7. Free radical scavenging activity of papaya juice

    Papaya juice is an efficient scavenger of highly reactive hydroxyl radicals (OH radical) formed during 60Co irradiation of water. The OH anion radicals were detected by the electron spin resonance (ESR) technique of spin trapping using DMPO (5,5-dimethyl-1-pyrroline-N-oxide) or by a colorimetric assay in which salicylate is converted into polyhydroxybenzoic acids. Papaya juice is also able to quench the ESR signal of a stable free radical (TEMPOL) and the ESR signal of the DMPO-OH adduct. The active substance(s) in papaya juice are heat-stable, dialyzable, and soluble in water but not in lipid solvents. The active agents do not appear to be ascorbate, tocopherol, or carotenoids. (author)

  8. RADICALLY CONTESTED ASSERTIONS IN ECOSYSTEM MANAGEMENT

    Ecosystem management is a magnet for controversy, in part because some of its formulations rest on questionable assertions that are radically contested. These assertions are important to understanding much of the conflict surrounding ecosystem management and, therrefore, deserve...

  9. Customers as Partners in Radical Service Innovation

    Scupola, Ada; Nicolajsen, Hanne Westh

    2009-01-01

    ongoing collaboration where creativity and trial and error are crucial. These needs require new ways of communicating and interacting between customer and consultants. Originality/value- This article is original because it generates new insights into conditions and challenges in radical innovations in......  Purpose- The main purpose of this paper is to investigate customer involvement and related challenges in radical service innovations in engineering consulting services Design/methodology/approach - The paper uses a case study approach and so called rich descriptions to investigate customer...... involvement, roles and related challenges and conditions in radical service innovations.Findings- One main finding is that customers can engage in radical service innovations in engineering consultancy services and may play a decisive role. In doing this they most likely take on all the three user involvement...

  10. A radical approach to asperparaline C

    Amatov, Tynchtyk; Jahn, Ullrich

    Praha: Czech Chemical Society, 2015. s. 41. [Liblice 2015. Advances in Organic, Bioorganic and Pharmaceutical Chemistry /50./. 06.11.2015-08.11.2015, Olomouc] Institutional support: RVO:61388963 Keywords : asperparalines * bridged diketopiperazines * radical reactions Subject RIV: CC - Organic Chemistry

  11. Innovation Type, Radicalness, and the Adoption Process.

    Damanpour, Fariborz

    1988-01-01

    Reviews studies on the impact of organizational factors on the adoption of innovations along three dimensions (innovation type, innovation radicalness, and stages of adoption), finding considerable agreement. Proposes a research agenda for future studies. (SR)

  12. Rigid Ideals and Radicals of Ore Extensions

    Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi

    2005-01-01

    For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.

  13. Fast beam studies of free radical photodissociation

    Neumark, D.M. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  14. Free radical reactions with subtilisin Carlsberg

    Pulse radiolysis has been used to study the mechanisms of radiation-induced inactivation of enzymes. However, interpretation of the results is often complicated by the fact that the G values for enzyme inactivation are usually much smaller than the G values for the radicals formed from water radiolysis. Where inactivation by oxidative free radical attack is concerned, the problem can often be greatly simplified by the use of the free radical probe technique. These free radicals, which include the halide-type radicals Cl2-, Br2-,I2- and (CNS)2-, react much more selectively than OH radicals with amino acids. They can be used to demonstrate that selective oxidation of certain amino acid residues can lead to enzyme inactivation. The technique assists, therefore, in determining whether such sensitive amino acids are present in the active centre and are crucial to the activity of the protein. A number of enzymes have been studied by this method and the amino acid residues found to be necessary for enzymic activitya are in agreement with those identified by conventional biochemical techniques. In these enzymes, free radical attack by the halide radicals leads to inactivation by damage to a single type of amino acid residue which is involved either in catalysis or binding of the substrate. Subtilisin Carlsberg is a serine protease consisting of a poly-peptide chain lacking both cysteine and cystine residues. This paper indicates the use of the selective probe technique in demonstrating that damage to one or more histidine residues leads to inactivation of the enzyme. (author)

  15. Radicalization and the Use of Social Media

    Robin Thompson

    2011-01-01

    The use of social media tools by individuals and organizations to radicalize individuals for political and social change has become increasingly popular as the Internet penetrates more of the world and mobile computing devices are more accessible. To establish a construct for radicalization,the power and reach of social media will be described so there is common understanding of what social media is and how it is utilized by various individuals and groups. The second section will answer the q...

  16. Modelling of tropospheric ozone and radical chemistry

    Burkert, Jörn

    2003-01-01

    This work describes in detail the photochemistry of ozone and radicals in both remote clean air and heavily polluted regions. The results of two field studies are presented: the Indian Ocean Experiment (INDOEX) and the Peroxy Radical Initiative for Measurements in the Environment (PRIME).The :b:INDOEX:/b: campaign studied the chemistry of remote areas of the Indian Ocean and the influence of the outflow from the Indian subcontinent on these regions. Measurements of trace gases (NMHC, O3, RO2*...

  17. Free Radicals, Antioxidants in Disease and Health

    Pham-Huy, Lien Ai; He, Hua; Pham-Huy, Chuong

    2008-01-01

    Free radicals and oxidants play a dual role as both toxic and beneficial compounds, since they can be either harmful or helpful to the body. They are produced either from normal cell metabolisms in situ or from external sources (pollution, cigarette smoke, radiation, medication). When an overload of free radicals cannot gradually be destroyed, their accumulation in the body generates a phenomenon called oxidative stress. This process plays a major part in the development of chronic and degene...

  18. The stabilization energies of polyenyl radicals

    Luo, Yu-Ran; Holmes, John L.

    1994-10-01

    The resonance stabilization energies, Es, of polyenyl radicals can be estimated by the equation Es( N)=-13.2+[3.95-15.8(2) -2/ n] kcal mol -1, where N is the number of C, C-π bonds in the polyenyl radicals. This correlation has been extended for predicting the weakest HC, CC and COH bond dissociation energies in vitamin A and similar compounds.

  19. OUR 6-YEAR EXPERIENCE IN RADICAL CYSTECTOMY

    Cevdet Kaya; Orhan Koca; Muzaffer Oğuz Keleş; Gülhan Yılmaz; Metin Öztürk; Hüseyin Kanberoğlu; M. İhsan Karaman

    2009-01-01

    Objective: Bladder cancer is the second most common cancer of the urinary tract. Radical cystectomy and urinary diversion is the gold standard treatment model of invasive bladder cancer.Patient and Methods: We evaluated 71 patients who underwent radical cystectomy, retrospectively according to their demographic properties, pre-operative and post-operative pathologies and method of urinary diversion and the complications between January 2003 and 2008.Results: Mean follow-up was 28.8 months aft...

  20. Project Radicalization: Why do "they" hate "us"?

    Eggert, Lasse; Foged, Mathias; Jensen, Martin

    2014-01-01

    The phenomenon of global terrorism is still not fully understood by the international community whether within the contingents of public decision-makers, security agencies and researchers. Radicalization as explanation and analytical tool for understanding terrorism has relatively recently gained new prominence. In this project the question of which discourses can be found in the scientific material within the research field of terrorism and radicalization is addressed. A sample of scientifi...

  1. Fatty acyl chain-dependent but charge-independent association of the SH4 domain of Lck with lipid membranes

    Anoop Rawat; Avaronnan Harishchandran; Ramakrishnan Nagaraj

    2013-03-01

    The SH4 domain of Src family of nonreceptor protein tyrosine kinases represents the extreme N-terminal 1–16 amino acid region which mediates membrane association of these proteins and facilitates their functions. The SH4 domains among Src members lack well-defined sequence consensus and vary in the net charge. However, they readily anchor to the cytoplasmic face of the plasma membrane upon fatty acid acylation. Here, we report the membrane association of differentially acylated SH4 domain of Lck kinase, which has net negative charge at physiological pH. Our results suggest that despite the net negative charge, the SH4 domain of Lck associates with membranes upon fatty acid acylation. While myristoylation at the N-terminus is sufficient for providing membrane anchorage, multiple acylation determines orientation of the peptide chain with respect to the lipid bilayer. Hence, fatty acylation serves more than just a lipid anchor. It has an important role in regulating the spatial orientation of the peptide domain with respect to the lipid bilayer, which could be important for the interaction of the other domains of these kinases with their partners.

  2. The monounsaturated acyl- and alkyl- moieties of wax esters and their distribution in commercial orange roughy (Hoplostethus atlanticus) oil.

    Body, D R; Johnson, C B; Shaw, G J

    1985-10-01

    Wax esters were isolated from commercial orange roughy (Hoplostethus atlanticus) oil by column chromatography and fractionated by argentation thin layer chromatography. Following transesterification, the resultant fatty acid methyl esters and fatty alcohols were analyzed by gas chromatography. Both acyl- and alkyl-moieties were mainly of the monoene structure within the 16:1-22:1 range. After derivatization, the positions of the double bonds of even numbered fatty acid and fatty alcohol isomers were located by chromatography-mass spectrometry and compared. Results of these positional analyses indicate that the primary desaturation reactions takes place in the delta 9 position of pre-existing (C14 to C24) acyl chains. It is proposed that acyl components from 18:1 are subjected to chain elongation to form a mixture of 24:1 isomers as the final product. Apart from the 24:1 acyl moiety of the wax esters, in which the double bond was almost exclusively in the delta 15 position, de novo biosynthetic reactions on acids and alcohols appear to yield related acyl- and alkyl-moieties of resynthesized wax esters. PMID:4058265

  3. Control of radical chemistry in the AdoMet-radical enzymes

    Duschene, Kaitlin S.; Veneziano, Susan E.; Silver, Sunshine C.; Broderick, Joan B.

    2009-01-01

    The radical AdoMet superfamily comprises a diverse set of >2800 enzymes that utilize iron-sulfur clusters and S-adenosylmethionine (SAM or AdoMet) to initiate a diverse set of radical-mediated reactions. The intricate control these enzymes exercise over the radical transformations they catalyze is an amazing feat of elegance and sophistication in biochemistry. This review focuses on the accumulating evidence for how these enzymes control this remarkable chemistry, including controlling the re...

  4. Reactions of alkoxy radicals in aqueous solutions

    The kinetic and mechanistic properties of alkoxy radicals in organic solvents are briefly reviewed. Owing to the scarcity of such data in aqueous solutions and since reactions at the membrane/water interface may be also biologically important, we have studied the reactivity of these radicals in water and the results of our investigations are reported. Alkoxy radicals were generated by photolytic or radiolytic cleavage of peroxide precursors (tert-butyl hydroperoxide and di-tert-butyl peroxide as well as hydroperoxides of polyunsaturated fatty acids). A quantitative correlation between the structure of various substances, in particular, phenolic antioxidants, and their activity in inhibiting the alkoxy radical-induced bleaching of the water-soluble carotenoid crocin will be discussed. Rate constants for intermolecular reactions of t-BuO. radicals were determined by pulse radiolysis. The diffusion-controlled reaction with the catechol antioxidant nordihydroguaiaretic acid demonstrates an effective competition with the very rapid intra molecular β-fragmentation in water. The results aupport the view that a considerable amount of alkoxy radicals interact with substrates before they can rearrange intramolecularly

  5. Reactions of alkoxy radicals in aqueous solutions

    Bors, W.; Tait, D.; Michel, C.; Saran, M.; Erben-Russ, M. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.). Abt. fuer Strahlenbiologie)

    1984-01-01

    The kinetic and mechanistic properties of alkoxy radicals in organic solvents are briefly reviewed. Owing to the scarcity of such data in aqueous solutions and since reactions at the membrane/water interface may be also biologically important, we have studied the reactivity of these radicals in water and the results of our investigations are reported. Alkoxy radicals were generated by photolytic or radiolytic cleavage of peroxide precursors (tert-butyl hydroperoxide and di-tert-butyl peroxide as well as hydroperoxides of polyunsaturated fatty acids). A quantitative correlation between the structure of various substances, in particular, phenolic antioxidants, and their activity in inhibiting the alkoxy radical-induced bleaching of the water-soluble carotenoid crocin will be discussed. Rate constants for intermolecular reactions of t-BuO. radicals were determined by pulse radiolysis. The diffusion-controlled reaction with the catechol antioxidant nordihydroguaiaretic acid demonstrates an effective competition with the very rapid intra molecular ..beta..-fragmentation in water. The results aupport the view that a considerable amount of alkoxy radicals interact with substrates before they can rearrange intramolecularly.

  6. Inactivation of Bacillus atrophaeus by OH radicals

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He–H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  7. Radioprotective thermally generated free-radical dextrins

    Piotr TOMASIK; Oskar MICHALSKI; Ewa BIDZINSKA; Antonina CEBULSKA-WASILEWSKA; Krystyna DYREK; Maciej FIEDOROWICZ; Pawel OLKO

    2008-01-01

    Effect of doses of the X-ray radiation from 0 to 400 Gy upon granular cornstarch and dextrins (British gums, BG) thermally generated from it at 230-300℃ was recognized with quantitative EPR and IR ab-sorption spectroscopy, molecular mass distribution in the depolymerization products, Scanning Elec-tron Microscopy, and X-ray diffractometry. Fractal analysis of the profiles of molecular mass distribu-tion showed that the depolymerization involved debranching of amylopectin. Roasting of cornstarch produced BG which differed in concentration and EPR parameters of stable free radicals from BG generated by X-ray radiation. Two types of stable free radicals, with Gaussian and Lorentzian shapes of EPR signals, were recognized. The shapes of the signals and temperature dependence on free radical intensity indicated exchanging interactions of the antiferromagnetic type, causing partial quenching of the spins at -196℃ (77K). Upon X-ray irradiation, new radicals were generated, the number and stability of which strongly depended on the types of radicals present before irradiation. These radicals slowly ceased because of a repolymerization of BG on storage.

  8. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-01-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions. PMID:27405843

  9. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-07-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions.

  10. Control of radical chemistry in the AdoMet-radical enzymes

    Duschene, Kaitlin S.; Veneziano, Susan E.; Silver, Sunshine C.; Broderick, Joan B.

    2009-01-01

    Summary The radical AdoMet superfamily comprises a diverse set of >2800 enzymes that utilize iron-sulfur clusters and S-adenosylmethionine (SAM or AdoMet) to initiate a diverse set of radical-mediated reactions. The intricate control these enzymes exercise over the radical transformations they catalyze is an amazing feat of elegance and sophistication in biochemistry. This review focuses on the accumulating evidence for how these enzymes control this remarkable chemistry, including controlling the reactivity between the iron-sulfur cluster and AdoMet, and controlling the subsequent radical transformations. PMID:19269883

  11. Control of radical chemistry in the AdoMet radical enzymes.

    Duschene, Kaitlin S; Veneziano, Susan E; Silver, Sunshine C; Broderick, Joan B

    2009-02-01

    The radical AdoMet superfamily comprises a diverse set of >2800 enzymes that utilize iron-sulfur clusters and S-adenosylmethionine (SAM or AdoMet) to initiate a diverse set of radical-mediated reactions. The intricate control these enzymes exercise over the radical transformations they catalyze is an amazing feat of elegance and sophistication in biochemistry. This review focuses on the accumulating evidence for how these enzymes control this remarkable chemistry, including controlling the reactivity between the iron-sulfur cluster and AdoMet, and controlling the subsequent radical transformations. PMID:19269883

  12. Characterization of the structure and immunostimulatory activity of a vaccine adjuvant, de-O-acylated lipooligosaccharide.

    Ji Eun Han

    Full Text Available Lipopolysaccharide (LPS is a major component of the outer membrane of Gram-negative bacteria. LPS elicits strong immunopathological responses during bacterial infection, and the lipid A moiety of LPS is responsible for this immunostimulatory activity. Lipid A exerts its biological activity by sending signals via TLR4 present on immune cells, and TLR4 agonists have been a target for vaccine adjuvant. Previously, we demonstrated an adjuvant activity of deacylated lipooligosaccharide (dLOS to viral and bacterial antigens. In this study, we characterized the chemical structure of dLOS and evaluated its immunostimulatory activity on mouse and human immune cells in comparison with monophosphoryl lipid A (MPL. dLOS consists of the R3-type core, a glucosamine disaccharide with two phosphate groups, and two N-linked acyl groups [corrected], and two N-linked acyl groups. dLOS was similar to MPL in induction of cytokine production in mouse peritoneal macrophages, but was a more potent activator in human monocytes and dendritic cells (DCs. Results of an analysis of allogeneic T cell responses revealed that dLOS induces Th1, Th2, and Th17-type immune responses in a dose-dependent manner. The immunostimulatory activities of dLOS were completely abrogated in TLR4(-/- mice, which confirms its TLR4-dependency. These results suggest that in the presence of the core oligosaccharide, O-linked acyl groups of LPS are dispensable for activating the TLR4 signaling pathway. dLOS did not cause any pathological effects or death at 0.25, 0.5, or 1 mg per kg body weight in mice in the acute toxicity tests. This result suggests that dLOS has a low toxicity. dLOS should be considered for further development as a safe and effective adjuvant for human vaccines.

  13. Acyl chain length and charge effect on Tamoxifen-lipid model membrane interactions

    Bilge, Duygu; Kazanci, Nadide; Severcan, Feride

    2013-05-01

    Tamoxifen (TAM), which is an antiestrogenic agent, is widely used during chemotherapy of breast, pancreas, brain and liver cancers. In this study, TAM and model membrane interactions in the form of multilamellar vesicles (MLVs) were studied for lipids containing different acyl chain length and different charge status as a function of different TAM (1, 6, 9 and 15 mol%) concentrations. Zwitterionic lipids namely dipalmitoyl phosphatidylcholine (DPPC), and dimyristoylphosphatidylcholine (DMPC) lipids were used to see the acyl chain length effect and anionic dipalmitoyl phosphtidylglycerol (DPPG) lipid was used to see the charge effect. For this purpose Fourier transform-infrared (FTIR) spectroscopic and differential scanning calorimetric (DSC) techniques have been conducted. For zwitterionic lipid, concentration dependent different action of TAM was observed both in the gel and liquid crystalline phases by significantly increasing the lipid order and decreasing the dynamics for 1 mol% TAM, while decreasing the lipid order and increasing the dynamics of the lipids for higher concentrations (6, 9 and 15 mol%). However, different than neutral lipids, the dynamics and disorder of DPPG liposome increased for all TAM concentrations. The interactions between TAM and head group of multilamellar liposomes was monitored by analyzing the Cdbnd O stretching and PO2- antisymmetric double bond stretching bands. Increasing Tamoxifen concentrations led to a dehydration around these functional groups in the polar part of the lipids. DSC studies showed that for all types of lipids, TAM eliminates the pre-transition, shifts the main phase transition to lower temperatures and broadened the phase transition curve. The results indicate that not the acyl chain length but the charge status of the polar head group induces different effects on lipid membranes order and dynamics.

  14. Acyl-Homoserine Lactone Recognition and Response Hindering the Quorum-Sensing Regulator EsaR

    Daniel J Schu; Scruggs, Jessica M.; Jared S Geissinger; Katherine G Michel; Stevens, Ann M.

    2014-01-01

    During quorum sensing in the plant pathogen Pantoea stewartii subsp. stewartii, EsaI, an acyl-homoserine lactone (AHL) synthase, and the transcription factor EsaR coordinately control capsular polysaccharide production. The capsule is expressed only at high cell density when AHL levels are high, leading to inactivation of EsaR. In lieu of detailed structural information, the precise mechanism whereby EsaR recognizes AHL and is hindered by it, in a response opposite to that of most other LuxR ...

  15. Global and Phylogenetic Distribution of Quorum Sensing Signals, Acyl Homoserine Lactones, in the Family of Vibrionaceae

    Rasmussen, Bastian Barker; Nielsen, Kristian Fog; Machado, Henrique;

    2014-01-01

    Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae in the...... homology, however not with geographical location. In conclusion, a wide range of AHL signals are produced by a number of clades in the Vibrionaceae family and these results will allow future investigations of inter- and intra-species interactions within this cosmopolitan family of marine bacteria....

  16. A severe genotype with favourable outcome in very long chain acyl-CoA dehydrogenase deficiency

    Touma, E H; Rashed, M S; Vianey-Saban, C; Sakr, A; Divry, P; Gregersen, N; Andresen, B S

    2001-01-01

    A patient with very long chain acyl-CoA dehydrogenase (VLCAD) deficiency is reported. He had a severe neonatal presentation and cardiomyopathy. He was found to be homozygous for a severe mutation with no residual enzyme activity. Tandem mass spectrometry on dried blood spots revealed increased lo...... chain acylcarnitines. VLCAD enzyme activity was severely decreased to 2% of control levels. Dietary management consisted of skimmed milk supplemented with medium chain triglycerides and L-carnitine. Outcome was good and there was no acute recurrence....

  17. Effect of room temperature ionic liquid structure on the enzymatic acylation of flavonoids

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Enzymatic acylation reactions of flavonoids (rutin, esculin) with long chain fatty acids (palmitic, oleic acids) were carried out in 14 different ionic liquid media containing a range of cation and anion structures. Classification of RTILs according to flavonoid solubility (using COSMO-RS) was the......-bonding ability) resulted in decreased yields, likely due to increased interactions with the protein structure of the lipase. Biosynthesis of rutin proceeded much slower than of esculin. All-in-all, judicious selection of RTILs was central to achieving high yields (>98% after 6 days for TOMA·TF2N) since a balance...

  18. Purification to homogeneity and characterization of acyl coenzyme A:6-aminopenicillanic acid acyltransferase of Penicillium chrysogenum.

    E. Alvarez; Cantoral, J M; Barredo, J L; Díez, B; Martín, J F

    1987-01-01

    The acyl coenzyme A (CoA):6-aminopenicillanic acid (6-APA) acyltransferase of Penicillium chrysogenum AS-P-78 was purified to homogeneity, as concluded by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing. The enzyme is a monomer with a molecular weight of 30,000 +/- 1,000 and a pI of about 5.5. The optimal pH and temperature were 8.0 and 25 degrees C, respectively. This enzyme converts 6-APA into penicillin by using phenylacetyl CoA or phenoxyacetyl CoA as ac...

  19. Retinal dystrophy in long chain 3-hydroxy-acyl-CoA dehydrogenase deficiency

    Schrijver-Wieling, I.; Rens, G.H.B.M. van; Wittebol-Post, D.; Smeitink, J.A.M.; De Jager, J P; Klerk, J.B.C. de; van Lith, G. H M

    1997-01-01

    BACKGROUND—Long chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) is one of the enzymes involved in the breakdown of fatty acids. A deficiency of this enzyme is associated with life threatening episodes of hypoketotic hypoglycaemia during prolonged fasting. Neuropathy and retinopigmentary changes were mentioned in only a few cases.
METHODS—The case histories of two girls, aged 8 and 15 years, with LCHAD deficiency are reported.
RESULTS—Both children with LCHAD deficiency exhibited extensive macu...

  20. Synthesis of new 3-and 4-substituted analogues of acyl homoserine lactone quorum sensing autoinducers

    Olsen, Jacob Alsbæk; Severinsen, Rune Eg; Rasmussen, Thomas Bovbjerg; Hentzer, Morten; Givskov, Michael Christian; Nielsen, John

    2002-01-01

    The quorum sensing mechanism in Gram-negative bacteria uses small intercellular signal molecules, N-acyl-homoserine lactones (AHLs), to control transcription of specific genes in relation to population density. In this communication, we describe the parallel synthesis of new AHL analogues, in whi...... substituents have been introduced into the 3- and 4-positions of the lactone ring. These analogues have been screened for their ability to activate and inhibit a Vibrio fischeri LuxI/LuxR-derived quorum sensing reporter system....

  1. Green photochemistry: the solar-chemical 'Photo-Friedel-Crafts acylation' of quinones

    Schiel, C.; Oelgemoeller, M.; Ortner, J.; Mattay, J.

    2001-07-01

    The photoreactions between 1,4-quinones (1 and 4) and aldehydes (2 and 5), yielding acylated hydroquinones as sole products, were investigated under artificial and solar irradiation conditions. Three different solar reactors were used for the photochemical syntheses with sunlight (PROPHIS, CPC and a flat bed reactor), and the CPC system was found to be the most robust one in terms of weather dependence. The solar reactions can be easily performed on a half-kilogram scale using cheap and commercially available starting materials. (author)

  2. Profiling Protein Kinases and Other ATP Binding Proteins in Arabidopsis Using Acyl-ATP Probes*

    Villamor, J. G.; Kaschani, F.; Colby, T; Oeljeklaus, J.; Zhao, D; Kaiser, M.; Patricelli, M. P.; R. A. L. van der Hoorn

    2013-01-01

    Many protein activities are driven by ATP binding and hydrolysis. Here, we explore the ATP binding proteome of the model plant Arabidopsis thaliana using acyl-ATP (AcATP)1 probes. These probes target ATP binding sites and covalently label lysine residues in the ATP binding pocket. Gel-based profiling using biotinylated AcATP showed that labeling is dependent on pH and divalent ions and can be competed by nucleotides. The vast majority of these AcATP-labeled proteins are known ATP binding prot...

  3. Molecular diagnosis and characterization of medium-chain acyl-CoA dehydrogenase deficiency

    Andresen, B S; Bross, P; Jensen, T G;

    1995-01-01

    Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common defect in mitochondrial beta-oxidation in humans. It is an autosomal recessive disorder which usually presents in infancy. The disease manifests itself in periods of metabolic stress to the beta-oxidation system and may be...... fatal. Four years ago we identified a prevalent disease-causing mutation (G985) which causes an amino acid change (K304E) in the mature MCAD protein. Using a Polymerase Chain Reaction (PCR) based assay for this mutation we have demonstrated: 1. that the G985 mutation is present in 90% of the disease...

  4. Effect of Cheonggukjang supplementation upon hepatic acyl-CoA synthase, carnitine palmitoyltransferase I, acyl-CoA oxidase and uncoupling protein 2 mRNA levels in C57BL/6J mice fed with high fat diet

    Soh, Ju-Ryoun; Shin, Dong-Hwa; Kwon, Dae Young; Cha, Youn-Soo

    2007-01-01

    This study investigated the effect of Cheonggukjang on mRNA levels of hepatic acyl-CoA synthase (ACS), carnitine palmitoyltransferase I (CPT-I), acyl-CoA oxidase (ACO) and uncoupling protein 2 (UCP2), and on serum lipid profiles in C57BL/6J mice. Thirty male C57BL/6J mice were divided into three groups; normal diet (ND), high fat diet (HD) and high fat diet with 40% Cheonggukjang (HDC). Energy intake was significantly higher in the HDC group than in the ND and HD groups. The HDC group normali...

  5. Pilot batch production of specific-structured lipids by lipase-catalyzed interesterification: preliminary study on incorporation and acyl migration

    Xu, Xuebing; Balchen, Steen; Høy, Carl-Erik; Adler-Nissen, Jens

    1998-01-01

    .2% for LML-type in the solvent-free systems, the incorporation rates in the first 5 hours increased from 3.34%/hr to 10.30%/hr, and from 7.29%/hr to 11.12%/hr, respectively. However, the acyl migration rates also increased from 0.22%/hr to 1.12%/hr and from 0.56%/hr to 1.37%/hr, respectively. Different...... the Michaelis-Menten equation, while the acyl migration is proportional to time within the range of 20% (mole) acyl migration (MLM-type: Mf=0.2225T, R²=0.9868; LML-type: Mf =0.5618T, R²=0.9961). As water content (wt%, on the enzyme basis) increased from 3.0% to 11.6% for MLM-type and from 3.0% to 7...

  6. Structural elucidation and biological activity of acyl-homoserine lactones from the phytopathogen Pantoea ananatis Serrano 1928.

    Pomini, Armando M; Araújo, Welington L; Marsaioli, Anita J

    2006-08-01

    In Gram-negative bacteria, the acyl-homoserine lactones (acyl-HSLs) are the main signaling substances employed in cell-to-cell communication systems. This paper describes the chemical characterization of acyl-HSLs produced by the worldwide-spread phytopathogen Pantoea ananatis (Serrano 1928) by using gas chromatography-electron impact mass spectrometry. The absolute configuration of the major identified substance, (S)-(--)-N-hexanoyl-HSL, was determined with gas chromatography-flame ionization detection with a chiral capillary column. Biological activities of extracts, fractions, and synthetic products were evaluated with the specific reporter Agrobacterium tumefaciensNTL4(pZLR4) in beta-galactosidase expression assays. PMID:16900431

  7. Affinity of 3-acyl substituted 4-quinolones at the benzodiazepine site of GABAA receptors

    Lager, Erik; Nilsson, Jakob; Nielsen, Elsebet Østergaard;

    2008-01-01

    The finding that alkyl 1,4-dihydro-4-oxoquinoline-3-carboxylate and N-alkyl-1,4-dihydro-4-oxoquinoline-3-carboxamide derivatives may be high-affinity ligands at the benzodiazepine binding site of the GABA(A) receptor, prompted a study of 3-acyl-1,4-dihydro-4-oxoquinoline (3-acyl-4-quinolones). In......- and a gamma-subunit in the GABA(A) receptor, selected compounds were tested on the alpha(1)beta(2)gamma(2s), alpha(2)beta(2)gamma(2s) and alpha(3)beta(2)gamma(2s) GABA(A) receptor subtypes. The 3-acyl-4-quinolones display various degrees of selectivity for alpha(1)- versus alpha(2)- and alpha(3...

  8. Use of acyl phosphonates for the synthesis of inulin esters and their use as emulsion stabilizing agents.

    Rogge, Tina M; Stevens, Christian V; Colpaert, Anton; Levecke, Bart; Booten, Karl

    2007-02-01

    Inulin, the polydisperse polyfructose, extracted from chicory, was modified via esterification with acyl phosphonates. The grafting of an acyl chain onto the inulin backbone under different conditions led to a highly efficient synthesis of a series of inulin esters, with interesting tensioactive properties. The derivatives were evaluated in oil-in-water (O/W) emulsions with isoparaffinic oil, Isopar M. Therefore, a 2% (w/v) aqueous solution of inulin-based surfactant was used in 50/50 O/W emulsions, in nonelectrolyte, and in electrolyte media, using 1 M MgSO4. Longer acyl chains, e.g., dodecanoyl (C12), hexadecanoyl (C16), and octadecanoyl (C18), with degrees of substitution lower than 0.5, gave rise to the highest emulsion stabilities against coalescence. PMID:17291072

  9. ESR study on carboxymethyl chitosan radicals in an aqueous solution

    Saiki, Seiichi, E-mail: saiki.seiichi@jaea.go.j [Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Nagasawa, Naotsugu; Hiroki, Akihiro; Morishita, Norio; Tamada, Masao [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Muroya, Yusa; Kudo, Hisaaki [Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Katsumura, Yosuke [Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan)

    2010-03-15

    Carboxymethyl chitosan (CMCTS) at a highly concentrated aqueous solution forms hydrogel by ionizing irradiation. To study on radiation-induced reaction mechanism of CMCTS in an aqueous solution, CMCTS radicals formed by reactions with OH radical were observed by ESR method. As a result of ESR spectral analysis, CMCTS radicals were identified as radicals on carboxymethyl groups.

  10. Plasma concentrations of acyl-ghrelin are associated with average daily gain and feeding behavior in grow-finish pigs.

    Lents, C A; Brown-Brandl, T M; Rohrer, G A; Oliver, W T; Freking, B A

    2016-04-01

    The objectives of this study were to determine the effect of sex, sire line, and litter size on concentrations of acyl-ghrelin and total ghrelin in plasma of grow-finish pigs and to understand the relationship of plasma concentrations of ghrelin with feeding behavior, average daily gain (ADG), and back fat in grow-finish swine. Yorkshire-Landrace crossbred dams were inseminated with semen from Yorkshire, Landrace, or Duroc sires. Within 24 h of birth, pigs were cross-fostered into litter sizes of normal (N; >12 pigs/litter) or small (S; ≤ 9 pigs/litter). At 8 wk of age, pigs (n = 240) were blocked by sire breed, sex, and litter size and assigned to pens (n = 6) containing commercial feeders modified with a system to monitor feeding behavior. Total time eating, number of daily meals, and duration of meals were recorded for each individual pig. Body weight was recorded every 4 wk. Back fat and loin eye area were recorded at the conclusion of the 12-wk feeding study. A blood sample was collected at week 7 of the study to quantify concentrations of acyl- and total ghrelin in plasma. Pigs from small litters weighed more (P sires had lesser (P sires, but plasma concentrations of total ghrelin were not affected by sire breed. Concentrations of acyl-ghrelin were positively correlated with the number of meals and negatively correlated with meal length and ADG (P < 0.05). A larger number of short-duration meals may indicate that pigs with greater concentrations of acyl-ghrelin consumed less total feed, which likely explains why they were leaner and grew more slowly. Acyl-ghrelin is involved in regulating feeding behavior in pigs, and measuring acyl-ghrelin is important when trying to understand the role of this hormone in swine physiology. PMID:26808977

  11. Preparation of 5-acyl- and 5-aryl-substituted 1-(benzyloxy)pyrazoles via directed ortho-lithiation/transmetalation and palladium catalyzed cross- coupling

    Kristensen, Jesper Langgaard; Begtrup, M.; Vedsø, P.

    1998-01-01

    Palladium(0) catalyzed cross-coupling of 1-(benzyloxy)pyrazol-5-ylzinc halides 3a,b, prepared by transmetalation of 1-(benzyloxy)-5-lithiopyrazole (2), with acyl chlorides produced 5 acyl-1-(benzyloxy)pyrazoles 4a-d in high yields. Similar coupling of the pyrazol-5-ylzinc halide with amino...

  12. DISTINCT TRANSCRIPTIONAL REGULATION OF LONG-CHAIN ACYL-COA SYNTHETASE ISOFORMS AND CYTOSOLIC THIOESTERASE 1 IN THE RODENT HEART BY FATTY ACIDS AND INSULIN

    The molecular mechanism(s) responsible for channeling long-chain fatty acids (LCFAs) into oxidative versus nonoxidative pathways is (are) poorly understood in the heart. Intracellular LCFAs are converted to long-chain fatty acyl-CoAs (LCFA-CoAs) by a family of long-chain acyl-CoA synthetases (ACSLs)...

  13. Acyl-CoA-binding protein (ACBP) localizes to the endoplasmic reticulum and Golgi in a ligand-dependent manner in mammalian cells

    Hansen, Jesper S; Færgeman, Nils J; Kragelund, Birthe B;

    2008-01-01

    In the present study, we microinjected fluorescently labelled liver bovine ACBP (acyl-CoA-binding protein) [FACI-50 (fluorescent acyl-CoA indicator-50)] into HeLa and BMGE (bovine mammary gland epithelial) cell lines to characterize the localization and dynamics of ACBP in living cells. Results...... vesicular trafficking....

  14. Enhancement of E. coli acyl-CoA synthetase FadD activity on medium chain fatty acids

    Ford, Tyler J.; Way, Jeffrey C

    2015-01-01

    FadD catalyses the first step in E. coli beta-oxidation, the activation of free fatty acids into acyl-CoA thioesters. This activation makes fatty acids competent for catabolism and reduction into derivatives like alcohols and alkanes. Alcohols and alkanes derived from medium chain fatty acids (MCFAs, 6–12 carbons) are potential biofuels; however, FadD has low activity on MCFAs. Herein, we generate mutations in fadD that enhance its acyl-CoA synthetase activity on MCFAs. Homology modeling reve...

  15. Functional Analysis of Long-chain Acyl-CoA Synthetase 1 in 3T3-L1 Adipocytes*

    Lobo, Sandra; Wiczer, Brian M.; Bernlohr, David A

    2009-01-01

    ACSL1 (acyl-CoA synthetase 1), the major acyl-CoA synthetase of adipocytes, has been proposed to function in adipocytes as mediating free fatty acid influx, esterification, and storage as triglyceride. To test this hypothesis, ACSL1 was stably silenced (knockdown (kd)) in 3T3-L1 cells, differentiated into adipocytes, and evaluated for changes in lipid metabolism. Surprisingly, ACSL1-silenced adipocytes exhibited no significant changes in basal or insulin-stimulated long-chain fatty acid uptak...

  16. ADP-abhängige Acyl-CoA Synthetasen in Archaea, Bacteria und Eukarya: Charakterisierung, Funktion und Phylogenie

    Schmidt, Marcel Clemens

    2013-01-01

    ADP-bildende Acetyl-CoA Synthetasen (ACD) gehören wie die Succinyl-CoA Synthetasen (SCS) zur Proteinfamilie der NDP-bildenden Acyl-CoA Synthetasen. Beide Enzyme sind ubiquitär in allen drei Domänen des Lebens vorhanden und katalysieren die NDP- und Pi-abhängige Umsetzung von Acyl-CoA Estern (Acetyl-CoA bzw. Succinyl-CoA) zu den kor-respondierenden Säuren unter der Bildung von NTP über Substratstufenphosphorylierung. Die ACD-Reaktion wurde erstmals in dem Acetat bildenden Protisten Entamo...

  17. Silica gel-Supported Palladium Catalyst for the Acyl Sonogashira Reaction

    Hossain, Shahin; Park, Jihoon; Park, Minkyu; Jin, Myungjong [Inha Univ., Incheon (Korea, Republic of)

    2013-06-15

    We have demonstrated an efficient and eco-friendly procedure for the synthesis of ynones using silica supported thiol-palladium complex as a recyclable catalyst under copper free mild reaction conditions. The material was synthesized by post grafting of 3-mercaptopropyltrimethoxysilane on amorphous silica and subsequently Pd(II) attached onto thiol groups. This synthetic method has notable advantages because it involves easily available, less costly and produces an easily recyclable catalyst in high yields of the products. The mild reaction conditions encouraged us to further extension for the development of novel multicomponent reactions. Thus we have explained the three component synthesis of pyrazoles in one-pot fashion with good yields. Specifically, this simple procedure for the ynone synthesis and this approach to synthesize N-containing heterocycles may be valuable tool in future. The acyl Sonogashira reaction between acyl chlorides and terminal alkynes is one of the most useful method for the preparation of ynones which are important intermediates to prepare versatile pharmaceutically and biologically active heterocyclic compounds such as pyrroles, pyrazoles, furans, furanones, isoxazoles, pyrimidines, quinolines, indolizidinones.

  18. Mechanism of the reaction catalyzed by acyl-CoA: lysolecithin acyltransferase from rabbit lung

    This paper deals with the first attempt to elucidate the chemical mechanism of acyl-CoA:lysolecithin acyltransferase from rabbit lung, a key enzyme in the metabolism of lung surfactant. For this purpose, the pH dependence of kinetic constants as well as the chemical modification of the protein have been studied on a partially-purified preparation. From these experiments, the pKs on which the activity of the enzyme relies have been calculated, giving values of pK1 approximately 5.5 and pK2 approximately 10. Analysis of the effect of organic solvents on these pKs and the calculation of the enthalpies of ionization, together with the chemical modification experiments, lead to the conclusion that pK1 is due to an histidine residue, whereas pK2 arises from the amino group of the adenine ring of palmitoyl-CoA. Moreover, chemical modification demonstrated an essential cysteine. A tentative chemical mechnism, in accordance with these results, is proposed and it is hypothesized, in view of other results obtained in our laboratory and from the literature, that the chemical mechanism of acyl transfer to sn-2 position may be common to other enzymes of glycerolipid metabolism. (author)

  19. Carboxylic acid terminated, solution exfoliated graphite by organic acylation and its application in drug delivery

    KOUSHIK BHOWMIK; AMRITA CHAKRAVARTY; U MANJU; GOUTAM DE; ARNAB MUKHERJEE

    2016-09-01

    Graphite nanosheets are considered as a promising material for a range of applications from flexible electronics to functional nanodevices such as biosensors, intelligent coatings and drug delivery. Chemical functionalizationof graphite nanosheets with organic/inorganic materials offers an alternative approach to control the electronic properties of graphene, which is a zero band gap semiconductor in pristine form. In this paper, we report the aromatic electrophilic substitution of solution exfoliated graphite nanosheets (SEGn). The highly conjugated π-electronic system of graphite nanosheets enable it to have an amphiphilic characteristic in aromatic substitution reactions. The substitution was achieved through Friedel–Crafts (FC) acylation reaction under mild conditions using succinic anhydride as acylating agent and anhydrous aluminum chloride as Lewisacid. Such reaction renders towards the carboxylic acid terminated graphite nanosheets (SEGn–FC) that usually requires harsh reaction conditions. The product thus obtained was characterized using various spectroscopicand microscopic techniques. Highly stable water-dispersed sodium salt of carboxylic acid terminated graphite nanosheets (SEGn–FC-Na) was also prepared. A comparative sheet-resistance measurements of SEGn, SEGn–FC and SEGn–FC-Na were also done. Finally, the anticancer drug doxorubicin (DOX) was loaded on water dispersible SEGn–FC-Na with a loading capacity of 0.266 mg mg−1 of SEGn–FC-Na and the release of DOX from this water-soluble DOX-loaded SEGn–FC-Na at two different temperatures was found to be strongly pHdependent.

  20. Silica gel-Supported Palladium Catalyst for the Acyl Sonogashira Reaction

    We have demonstrated an efficient and eco-friendly procedure for the synthesis of ynones using silica supported thiol-palladium complex as a recyclable catalyst under copper free mild reaction conditions. The material was synthesized by post grafting of 3-mercaptopropyltrimethoxysilane on amorphous silica and subsequently Pd(II) attached onto thiol groups. This synthetic method has notable advantages because it involves easily available, less costly and produces an easily recyclable catalyst in high yields of the products. The mild reaction conditions encouraged us to further extension for the development of novel multicomponent reactions. Thus we have explained the three component synthesis of pyrazoles in one-pot fashion with good yields. Specifically, this simple procedure for the ynone synthesis and this approach to synthesize N-containing heterocycles may be valuable tool in future. The acyl Sonogashira reaction between acyl chlorides and terminal alkynes is one of the most useful method for the preparation of ynones which are important intermediates to prepare versatile pharmaceutically and biologically active heterocyclic compounds such as pyrroles, pyrazoles, furans, furanones, isoxazoles, pyrimidines, quinolines, indolizidinones

  1. Enzymatic modification of palmarosa essential oil: chemical analysis and olfactory evaluation of acylated products.

    Ramilijaona, Jade; Raynaud, Elsa; Bouhlel, Charfeddine; Sarrazin, Elise; Fernandez, Xavier; Antoniotti, Sylvain

    2013-12-01

    We have developed an enzymatic protocol to modify the composition of palmarosa essential oil by acylation of its alcohol components by three different acyl donors at various rates. The resulting modified products were characterized by qualitative and quantitative analyses by gas chromatography, and their olfactory properties were evaluated by professional perfumers. We showed that our protocol resulted in two types of modifications of the olfactory properties. The first and most obvious effect observed was the decrease of the alcohol content, with the concomitant increase of the corresponding esters, along with their fruity notes (pear, most notably). The second and less obvious effect was the expression of notes from minor components ((E)-β-ocimene, linalool, β-caryophyllene, and farnesene), originally masked by the sweet-floral-rose odor of geraniol, present in 70% in the palmarosa essential oil used, and emergence of citrus, green, spicy and clove characters in the modified products. This methodology might be considered in the future as a sustainable route to new natural ingredients for the perfumer. PMID:24327448

  2. gfp-based N-acyl homoserine-lactone sensor systems for detection of bacterial communication

    Andersen, Jens Bo; Heydorn, Arne; Hentzer, Morten; Eberl, Leo; Geisenberger, Otto; Christensen, Bjarke Bak; Molin, Søren; Givskov, Michael Christian

    2001-01-01

    In order to perform single-cell analysis and online studies of N-acyl homoserine lactone (AHL)-mediated communication among bacteria, components of the Vibrio fischeri quorum sensor encoded by luxR-P-luxI have been fused to modified versions of gfpmut3* genes encoding unstable green fluorescent p...... detection at the single-cell level and allowed for real-time measurements of fluctuations in AHL concentrations. This green fluorescent AHL sensor provides a state-of-the art tool for studies of communication between the individuals present in mixed bacterial communities.......In order to perform single-cell analysis and online studies of N-acyl homoserine lactone (AHL)-mediated communication among bacteria, components of the Vibrio fischeri quorum sensor encoded by luxR-P-luxI have been fused to modified versions of gfpmut3* genes encoding unstable green fluorescent...... proteins. Bacterial strains harboring this green fluorescent sensor detected a broad spectrum of AHL molecules and were capable of sensing the presence of 5 nM N-3-oxohexanoyl-L-homoserine lactone in the surroundings. In combination with epifluorescent microscopy, the sensitivity of the sensor enabled AHL...

  3. Deciphering the roles of acyl-CoA-binding proteins in plant cells.

    Lung, Shiu-Cheung; Chye, Mee-Len

    2016-09-01

    Lipid trafficking is vital for metabolite exchange and signal communications between organelles and endomembranes. Acyl-CoA-binding proteins (ACBPs) are involved in the intracellular transport, protection, and pool formation of acyl-CoA esters, which are important intermediates and regulators in lipid metabolism and cellular signaling. In this review, we highlight recent advances in our understanding of plant ACBP families from a cellular and developmental perspective. Plant ACBPs have been extensively studied in Arabidopsis thaliana (a dicot) and to a lesser extent in Oryza sativa (a monocot). Thus far, they have been detected in the plasma membrane, vesicles, endoplasmic reticulum, Golgi apparatus, apoplast, cytosol, nuclear periphery, and peroxisomes. In combination with biochemical and molecular genetic tools, the widespread subcellular distribution of respective ACBP members has been explicitly linked to their functions in lipid metabolism during development and in response to stresses. At the cellular level, strong expression of specific ACBP homologs in specialized cells, such as embryos, stem epidermis, guard cells, male gametophytes, and phloem sap, is of relevance to their corresponding distinct roles in organ development and stress responses. Other interesting patterns in their subcellular localization and spatial expression that prompt new directions in future investigations are discussed. PMID:26340904

  4. Modeling Radicalization Phenomena in Heterogeneous Populations.

    Galam, Serge; Javarone, Marco Alberto

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  5. Modeling Radicalization Phenomena in Heterogeneous Populations.

    Serge Galam

    Full Text Available The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration.

  6. Modeling Radicalization Phenomena in Heterogeneous Populations

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  7. Analysis of radicals induced in irradiated foods

    By electron spin resonance (ESR) spectroscopy, we revealed free radicals in γ-ray irradiated foods; black pepper, green coffee bean and ginseng. We also analyzed the decay behavior of radiation induced free radicals during storage of irradiated foods. The ESR spectrum of experimental irradiated foods consists of a sextet signal centered at g=2.0 and a singlet signal at the same g-value position and a singlet signal at g=4.0. The singlet signal at g=2.0 is originated from organic free radicals and its peak intensity showed the dependence of γ-ray irradiation dose levels. The signal intensity was decreased during storage. Only after 3 hours of radiation treatment the peak intensity was decreased fast and after that the intensity was decreased slowly. The relaxation times, T1 and T2, of radiation induced free radicals showed the variations before and after irradiation. During long time storage period it was shown that T1 was increased and T2 was decreased. By analysis of decay process using the simulation methods based on the theory of reaction speed, it is considered that at least two kinds of radicals were induced in irradiated foods during long time storage. (author)

  8. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-11-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry.

  9. Free Radical Scavenging Activity of Leaves of Alocasia indica (Linn)

    Mulla, W. A.; Salunkhe, V. R.; Kuchekar, S. B.; Qureshi, M. N.

    2009-01-01

    The free radical scavenging potential of the plant Alocasia indica(Linn.) was studied by using different antioxidant models of screening like scavenging of 1,1-diphenyl-2-picryl hydrazyl radical, nitric oxide radical, superoxide anion radical, hydroxyl radical, iron chelating activity, total antioxidant capacity, non-enzymatic glycosylation of haemoglobin, rapid screening for antioxidant compounds by thin layer chromatography. The hydroalcoholic extract at 1000 μg/ml showed maximum scavenging...

  10. Formation of semiquinone radical anion and free radical scavenging reactions of plumbagin. A pulse radiolysis study

    Kinetics and mechanism of scavenging of reducing free radicals by plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) are studied using pulse radiolysis technique. It scavenged superoxide radical, hydroxyethyl radical and hydrated electron with bimolecular rate constants of 8.9 × 107, 2.3 × 109 and 1.6 × 1010 M-1 s-1, respectively in aqueous-alcohol medium. Plumbagin also scavenged linoleic acid peroxyl radical and tyrosyl radical with bimolecular rate constants of 1.0 × 108 and 7.0 × 106 M-1 s-1, respectively. Further, redox properties of plumbagin and its transients are studied using standard redox couples and cyclic voltammetry. (author)

  11. Isolation of Hypervalent Group-16 Radicals and Their Application in Organic-Radical Batteries.

    Imada, Yasuyuki; Nakano, Hideyuki; Furukawa, Ko; Kishi, Ryohei; Nakano, Masayoshi; Maruyama, Hitoshi; Nakamoto, Masaaki; Sekiguchi, Akira; Ogawa, Masahiro; Ohta, Toshiaki; Yamamoto, Yohsuke

    2016-01-20

    Using a newly prepared tridentate ligand, we isolated hypervalent sulfur and selenium radicals for the first time and characterized their structures. X-ray crystallography, electron spin resonance spectroscopy, and density functional theory calculations revealed a three-coordinate hypervalent structure. Utilizing the reversible redox reactions between hypervalent radicals and the corresponding anions bearing Li(+), we developed organic radical batteries with these compounds as cathode-active materials. Furthermore, an all-radical battery, with these compounds as the cathode and a silyl radical as the anode, was developed that exhibited a practical discharge potential of ∼ 1.8 V and stable cycle performance, demonstrating the potential of these materials for use in metal-free batteries that can replace conventional Li-ion batteries where Li is used in the metal form. PMID:26721786

  12. Radical kinetics and characterization of the free radicals in gamma irradiated red pepper

    Kinetic behaviors and characterization of the natural and γ-induced radicals in irradiated red pepper have been investigated by electron spin resonance (ESR) spectroscopy to explore the possibility of using this technique in detecting irradiated red pepper and to evaluate the eventual dosimetric features of this widely used food. Unirradiated samples exhibited a single resonance line centered at g=2.0050±0.0005. Photo-exposure of the samples was found to increase the signal intensity. An increase in temperature created a drastic decrease in the concentration of natural radicals responsible for the single resonance line. Irradiation was observed to induce increases in the intensity of single resonance line (signal I) and a radiation specific doublet and/or triplet (signal II) also centered at g=2.0050 but detectable only at high spectrometer gains. The intensities of both signals increased with increasing radiation dose. The signals I and II were found to decay with different rates depending on the temperature. The results of a fitting procedure applied to the experimental signal decay curves and those obtained from room temperature spectra simulation calculations were used together to determine radical species and their spectral characteristics giving rise to the observed experimental spectra. Four radical species, three carbohydrate and one semiquinone radical assigned as radicals A, B, C and D, respectively, were found to best explain the experimental results. All the radicals show large g and hyperfine splitting anisotropies varying between g=2.0028-2.0062 and 1.07-2.58 mT, respectively. The half lives of the radicals were found to depend strongly on temperature. The activation energy calculated using temperature dependent half-life data were the highest for radical A (33.68 kcal/mol) and smallest for radical C (11.83 kcal/mol)

  13. Free-radical chemistry of thiourea in aqueous solution, induced by OH radical, H atom, α-hydroxyalkyl radicals, photoexcited maleimide, and the solvated electron

    Hydroxyl radicals react with thiourea (and its tetramethyl derivative) yielding dimeric radical cations which are characterized by strong absorptions at 400 nm (450 nm). An analysis of the kinetics of the buildup of these absorptions gives evidence for the intermediacy of OH-adducts and the monomeric radical cations. The dimeric radical cations are also generated in the reactions of triplet-excited maleimide with those thioureas. Moreover, in acidic solutions even reducing radicals such as the H atom and α-hydroxy alkyl radicals give rise to these intermediates in full yields, albeit displaying different kinetics. Potential mechanistic implications are discussed. The dimeric thiourea radical cations are strong oxidants and readily oxidize the anions of phenol and 2'-deoxyguanosine. The solvated electron gives rise to an intermediate which is rapidly protonated by water (pKa > 11). Quantum mechanical calculations support the assignment of the 400 nm (450 nm) absorption to the respective dimeric thiourea radical cation. (author)

  14. Exploring how lead users develop radical innovation

    Lettl, Christopher; Gemuenden, Hans Georg; Hienerth, C.

    2008-01-01

    In this study, we explore how lead users develop radical innovations outside of manufacturing firms. We analyze the transition from a very early stage of activities to the ultimate commercialization of these innovations. The focus in this context is on the initiatives undertaken by lead users in...... lead users as surgeons launch entrepreneurial activities and bridge periods in which established medical equipment manufacturers would not risk investing in radical innovations. By doing so, lead users create the conditions usually provided in manufacturer-initiated lead user projects, including the...... supply of diversified knowledge, the development and coordination of a network for further development of the innovation, and initial tests of technical or market feasibility. Our findings have implications for manufacturing firms that wish to design radical innovation projects with (individual) lead...

  15. Radiation chemistry of aromatic dimer radical cations

    π-π Interactions of aromatic molecules are paid attention much in many fields, especially biology, chemistry, and applied physics, represented as protein, DNA, electron donor-accepter complexes, charge transfers, and self assembly molecules. Aromatic molecules including benzene rings are the simplest case to study the π-π interactions. To interpret the charge resonance (CR) structure in the dimer radical cations, spectroscopic and ESR methods have been carried out. The spectroscopic study on the dimer radical ion of molecules with two chromophores would be profitable to identify the electronic and configurational properties. In this article, dynamics of the dimer radical cation of benzenes, polystyrenes, and resist polymers is described on the basis of direct observation of CR band by the nanosecond pulse radiolysis and low temperature γ-radiolysis methods. (author)

  16. Radical abdominoplasty, including body shaping: representative cases.

    Mühlbauer, W

    1989-01-01

    Even in the age of liposuction there exist certain situations for which abdominoplasty in its radical form is indicated--for example, redundant skin after radical weight loss, the stigmata of postpregnancy syndrome, and localized accumulation of adipose tissue--the lipodystrophies and resistant generalized obesity. Redundant skin after radical weight loss is resected simultaneously around the abdomen, the lumbar regions, the perineum, and the thighs. The typical stigmata of postpregnancy syndrome may be excised through an extended abdominoplasty combined with simultaneous excision and pexy of the inner aspects of the thighs leaving a "bikini" scar behind. A mastopexy may be added. Genetically predisposed localized lipodystrophies in the abdominal lumbar, and upper thigh region may be resected through a circular abdominoplasty with or without simultaneous resection of the perineum and inner thighs. Abdominal aprons often contain umbilical or ventral hernias that may need to be repaired simultaneously. Representative cases are presented and dangers and complications are discussed. PMID:2741749

  17. Preparation and study of dialkyl nitroxide radicals

    These radicals are obtained by oxidation of N-hydroxy-imides with lead tetracetate or p-nitro-perbenzoic acid. These imides are prepared by heating dicarboxylic acids anhydrides with benzyloxy-amine followed by catalytic hydrogenation of N-benzyloxy-imides so obtained. Two series of radicals have mainly been studied, the first concerning five-membered cyclic imides, the second six-membered cyclic imides, these molecules having methyls substituents or no on the carbon ring. N. M. R. spectra of some O-benzyl-imides have been analysed. These different results have made it possible to study the conformation and stereochemistry of these imides. (author)

  18. Free Radicals in Adolescent Varicocele Testis

    Carmelo Romeo; Giuseppe Santoro

    2014-01-01

    We examine the relationship between the structure and function of the testis and the oxidative and nitrosative stress, determined by an excessive production of free radicals and/or decreased availability of antioxidant defenses, which occur in the testis of adolescents affected by varicocele. Moreover, the effects of surgical treatment on oxidative stress were provided. We conducted a PubMed and Medline search between 1980 and 2014 using “adolescent,” “varicocele,” “free radicals,” “oxidative...

  19. Free-radical kinetics of coal liquefaction

    Wang, M.; Smith, J.M.; McCoy, B.J.

    1994-07-16

    A rate expression with first- and second-order terms in the concentration of extractable compounds in solid coal particles is derived from a fundamental free-radical mechanism. The expression was suggested empirically by prior experiments for coal liquefaction in the presence of a hydrogen-donor solvent. Radical reactions are considered to occur in both coal and in solvent. The long-chain approximation justifies the neglect of initiation, hydrogen abstraction, and termination rates as quantitatively insignificant relative to propagation reaction rates.

  20. Resonance ionization detection of combustion radicals

    Cool, T.A. [Cornell Univ., Ithaca, NY (United States)

    1993-12-01

    Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

  1. Resonant cavity spectroscopy of radical species

    Ritchie, Grant

    2015-04-01

    Photo-oxidation in the troposphere is highly complex, being initiated by short lived radical species, in the daytime dominated by the hydroxyl radical, OH, with contributions from Cl atoms, and at night by either NO3 radicals or ozone. Chemical oxidation cycles, which couple OH, HO2 and peroxy (RO2) radical species, remove primary emitted trace species which are harmful to humans or to the wider environment. However, many of the secondary products produced by atmospheric photo-oxidation are also directly harmful, for example O3, NO2, acidic and multifunctional species, many of which are of low volatility and are able to partition effectively to the condensed phase, creating secondary organic aerosol (SOA), which contributes a significant fraction of tropospheric aerosol, with associated impacts on climate and human health. The accuracy of atmospheric models to predict these impacts necessarily requires accurate knowledge of the chemical oxidative cycling. Two of the simplest intermediates are the hydroperoxy radical, HO2, and the smallest and dominant organic peroxy radical, CH3O2, formed directly by the reactions of OH with CO/O2 and CH4/O2, respectively, and indirectly following the oxidation of larger VOCs. OH, HO2 and RO2 (collectively known as ROx) are rapidly cycled, being at the centre of tropospheric oxidation, and hence are some of the best targets for models to compare with field data. The reaction of HO2 and RO2 with NO constitutes the only tropospheric in-situ source of O3. Despite their importance, neither HO2 nor CH3O2 is measured directly in the atmosphere. HO2 is only measured indirectly following its conversion to OH and CH3O2 is not measured at all. Typically only the sum of RO2 radicals is measured, making no distinction between different organic peroxy radicals. This contribution will detail recent studies using (i) optical feedback cavity enhanced absorption spectroscopy with both quantum and inter-band cascade lasers in the mid-IR, and (ii

  2. Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

    Béla Fiser

    Full Text Available Non-reactive, comparative (2 × 1.2 μs molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule and hydroxyl radical (OH(•, guest molecule. From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(• complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels.

  3. Radical scavenging ability of some compounds isolated from Piper cubeba towards free radicals.

    Aboul-Enein, Hassan Y; Kładna, Aleksandra; Kruk, Irena

    2011-01-01

    The purpose of this study was to identify the antioxidant activity of 16 compounds isolated from Piper cubeba (CNCs) through the extent of their capacities to scavenge free radicals, hydroxyl radical (HO(•)), superoxide anion radical O•(2)(-) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)), in different systems. Electron paramagnetic resonance (EPR) and 5,5-dimethyl-1-pyrroline-N-oxide, DMPO, as the spin trap, and chemiluminescence techniques were applied. Using the Fenton-like reaction [Fe(II) + H(2)O(2)], CNCs were found to inhibit DMPO-OH radical formation ranging from 5 to 57% at 1.25 mmol L(-1) concentration. The examined CNCs also showed a high DPPH antiradical activity (ranging from 15 to 99% at 5 mmol L(-1) concentration). Furthermore, the results indicated that seven of the 16 tested compounds may catalyse the conversion of superoxide radicals generated in the potassium superoxide/18-crown-6 ether system, thus showing superoxide dismutase-like activity. The data obtained suggest that radical scavenging properties of CNCs might have potential application in many plant medicines. PMID:21681910

  4. Inactivation efficiencies of radical reactions with biologically active DNA

    Dilute aqueous solutions of biologically active ΦX174 DNA may serve as a simplified model system of the cell. Damage to the DNA after irradiation with γ-rays, may be ascribed to reactions with radical OH, radical H and esub(aq)- or secondary radicals, arising from reactions of water radicals with added scavengers. Conversion of primary (water) radicals into secondary (scavenger) radicals leads to a considerable protection of the DNA, which however, would have been larger if these secondary radicals did not contribute to DNA inactivation. The inactivation yield due to isopropanol or formate (secondary) radicals depends on dose rate as well as DNA concentration. Furthermore the inactivation efficiencies of the reactions of both the primary and the secondary radicals with single-stranded DNA could be established. (author)

  5. Computer aided drug designing of imidazole free acyl piperazine derivative as a histamine H/sub 3/ receptor antagonist

    Computer aided drug designing of 1- alkyl-4-acyl piperazine derivative was performed by Argus Lab software. The minimum potential energy is calculated by geometry convergence function by Argus lab software. The most feasible position for the drug to interact with the receptor was found to be 51.19358580 kcal/mol. (author)

  6. Clear relationship between ETF/ETFDH genotype and phenotype in patients with multiple acyl-CoA dehydrogenation deficiency

    Olsen, Rikke K J; Andresen, Brage S; Christensen, Ernst;

    2003-01-01

    Mutations in electron transfer flavoprotein (ETF) and its dehydrogenase (ETFDH) are the molecular basis of multiple acyl-CoA dehydrogenation deficiency (MADD), an autosomal recessively inherited and clinically heterogeneous disease that has been divided into three clinical forms: a neonatal...

  7. DNA-based prenatal diagnosis for severe and variant forms of multiple acyl-CoA dehydrogenation deficiency

    Olsen, Rikke K J; Andresen, Brage S; Christensen, Ernst;

    2005-01-01

    OBJECTIVES: Multiple acyl-CoA dehydrogenation deficiency (MADD) is a clinically heterogeneous disorder of mitochondrial fatty acid, amino acid, and choline oxidation due to mutations in the genes encoding electron transfer flavoprotein (ETF) or ETF ubiquinone oxidoreductase (ETFQO). So far...

  8. ETFDH mutations as a major cause of riboflavin-responsive multiple acyl-CoA dehydrogenation deficiency

    Olsen, Rikke K J; Olpin, Simon E; Andresen, Brage S;

    2007-01-01

    Multiple acyl-CoA dehydrogenation deficiency (MADD) is a disorder of fatty acid, amino acid and choline metabolism that can result from defects in two flavoproteins, electron transfer flavoprotein (ETF) or ETF: ubiquinone oxidoreductase (ETF:QO). Some patients respond to pharmacological doses of...

  9. Transient multiple acyl-CoA dehydrogenation deficiency in a newborn female caused by maternal riboflavin deficiency

    Chiong, M A; Sim, K G; Carpenter, K;

    2007-01-01

    A newborn female presented on the first day of life with clinical and biochemical findings consistent with multiple acyl-CoA dehydrogenase deficiency (MADD). Riboflavin supplementation corrected the biochemical abnormalities 24 h after commencing the vitamin. In vitro acylcarnitine profiling in i...

  10. Acyl-CoA synthetase activity links wild-type but not mutant a-Synuclein to brain arachidonate metabolism

    Golovko, Mikhail; Rosenberger, Thad; Færgeman, Nils J.;

    2006-01-01

    an established steady-state kinetic model. Liver was used as a negative control, and no changes were observed between groups. In Snca-/- brains, there was a marked reduction in 20:4n-6-CoA mass and in microsomal acyl-CoA synthetase (Acsl) activity toward 20:4n-6. Microsomal Acsl activity was...

  11. Crystallization of the C-terminal domain of the mouse brain cytosolic long-chain acyl-CoA thioesterase

    The C-terminal domain of the mouse long-chain acyl-CoA thioesterase has been expressed in bacteria and crystallized by vapour diffusion. The crystals diffract to 2.4 Å resolution. The mammalian long-chain acyl-CoA thioesterase, the enzyme that catalyses the hydrolysis of acyl-CoAs to free fatty acids, contains two fused 4HBT (4-hydroxybenzoyl-CoA thioesterase) motifs. The C-terminal domain of the mouse long-chain acyl-CoA thioesterase (Acot7) has been expressed in bacteria and crystallized. The crystals were obtained by vapour diffusion using PEG 2000 MME as precipitant at pH 7.0 and 290 K. The crystals have the symmetry of space group R32 (unit-cell parameters a = b = 136.83, c = 99.82 Å, γ = 120°). Two molecules are expected in the asymmetric unit. The crystals diffract to 2.4 Å resolution using the laboratory X-ray source and are suitable for crystal structure determination

  12. Evaluation of Effect of Microwave Irradiation on Syntheses and Reactions of Some New 3-Acyl-methylchromones

    Mikulas Furdik

    1998-03-01

    Full Text Available The 3-Acyl-2-R-methylchromones (R = H, ArO, C6H4(CO2N were prepared in good yields by different methods from 2-hydroxyaroylacetone derivatives. Some subsequent reactions of these compounds with hydroxylamine and 3-formylchromones are described. The effect of microwave irradation on some condensation reactions was studied.

  13. Studies of antimicrobial activity of N-alkyl and N-acyl 2-(4-thiazolyl)-1H-benzimidazoles.

    Pawar, N S; Dalal, D S; Shimpi, S R; Mahulikar, P P

    2004-02-01

    Various N-alkyl and N-acyl derivatives of 2-(4-thiazolyl)-1H-benzimidazole, an anthelmintic and systemic fungicide, were synthesized by polymer-supported reactions and screened for their antifungal and antibacterial potency to establish structure-activity relationships. PMID:14757482

  14. Identification of four new mutations in the short-chain acyl-CoA dehydrogenase (SCAD) gene in two patients

    Gregersen, N; Winter, V S; Corydon, M J; Corydon, T J; Rinaldo, P; Ribes, A; Martinez, G; Bennett, M J; Vianey-Saban, C; Bhala, A; Hale, D E; Lehnert, W; Kmoch, S; Roig, M; Riudor, E; Eiberg, H; Andresen, B S; Bross, P; Bolund, L A; Kølvraa, S

    1998-01-01

    We have shown previously that a variant allele of the short-chain acyl-CoA dehydrogenase ( SCAD ) gene, 625G-->A, is present in homozygous form in 7% of control individuals and in 60% of 135 patients with elevated urinary excretion of ethylmalonic acid (EMA). We have now characterized three disea...

  15. Ethylmalonic aciduria is associated with an amino acid variant of short chain acyl-coenzyme A dehydrogenase

    Corydon, M J; Gregersen, N; Lehnert, W; Ribes, A; Rinaldo, P; Kmoch, S; Christensen, E; Kristensen, T J; Andresen, B S; Bross, P; Winter, V; Martinez, G; Neve, S; Jensen, T G; Bolund, L; Kølvraa, S

    1996-01-01

    Ethylmalonic aciduria is a common biochemical finding in patients with inborn errors of short chain fatty acid beta-oxidation. The urinary excretion of ethylmalonic acid (EMA) may stem from decreased oxidation by short chain acyl-CoA dehydrogenase (SCAD) of butyryl-CoA, which is alternatively met...

  16. Kinetics of enzyme acylation and deacylation in the penicillin acylase-catalyzed synthesis of beta-lactam antibiotics

    Alkema, WBL; de Vries, E; Floris, R; Janssen, DB

    2003-01-01

    Penicillin acylase catalyses the hydrolysis and synthesis of semisynthetic beta-lactam antibiotics via formation of a covalent acyl-enzyme intermediate. The kinetic and mechanistic aspects of these reactions were studied. Stopped-flow experiments with the penicillin and ampicillin analogues 2-nitro-

  17. High activity of iron containing metal-organic-framework in acylation of p-xylene with benzoyl chloride

    Kurfiřtová, Lenka; Seo, Y.; K.; Hwang, Y. K.; Chang, J.; S.; Čejka, Jiří

    2012-01-01

    Roč. 179, č. 1 (2012), s. 85-90. ISSN 0920-5861 R&D Projects: GA ČR GA104/07/0383 Institutional research plan: CEZ:AV0Z40400503 Keywords : acylation * p-xylene * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.980, year: 2012

  18. Long-chain Acyl-CoA is not primarily increased in myotubes established from type 2 diabetic subjects

    Just, Malene; Faergeman, Nils J; Knudsen, Jens; Beck-Nielsen, Henning; Gaster, Michael

    2006-01-01

    Accumulation of intramuscular long-chain acyl-CoA esters (LCACoA) has previously in animal and human models been suggested to play an important role in lipid induced insulin resistance. The aim of this study was to examine whether myotubes established from type 2 diabetic (T2D) subjects and lean ...

  19. The binding versatility of plant acyl-CoA-binding proteins and their significance in lipid metabolism.

    Lung, Shiu-Cheung; Chye, Mee-Len

    2016-09-01

    Acyl-CoA esters are the activated form of fatty acids and play important roles in lipid metabolism and the regulation of cell functions. They are bound and transported by nonenzymic proteins such as the acyl-CoA-binding proteins (ACBPs). Although plant ACBPs were so named by virtue of amino acid homology to existing yeast and mammalian counterparts, recent studies revealed that ligand specificities of plant ACBPs are not restricted to acyl-CoA esters. Arabidopsis and rice ACBPs also interact with phospholipids, and their affinities to different acyl-CoA species and phospholipid classes vary amongst isoforms. Their ligands also include heavy metals. Interactors of plant ACBPs are further diversified due to the evolution of protein-protein interacting domains. This review summarizes our current understanding of plant ACBPs with a focus on their binding versatility. Their broad ligand range is of paramount significance in serving a multitude of functions during development and stress responses as discussed herein. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:26747650

  20. The Effect of Zeolite Pore Size and Channel Dimensionality on the Selective Acylation of Napthalene with Acetic Anhydride

    Čejka, Jiří; Prokešová, Pavla; Červený, L.; Mikulcová, K.

    Amsterdam : Elsevier, 2002 - (Aielo, R.; Giordano, G.; Testa, F.), s. 627-634 - (Studies in Surface Science and Catalysis.. 142 A). [International FEZA Conference /2./. Taormina (IT), 01.09.2002-05.09.2002] Institutional research plan: CEZ:AV0Z4040901 Keywords : acylation of naphthalene * 2-acetylnaphthalene * zeolite Beta Subject RIV: CF - Physical ; Theoretical Chemistry

  1. Study on the reactions of azo compounds with acyl halides mediated by Sm/TiCl4 *

    Li, Xue; Zhang, Yong-min

    2006-01-01

    Amides can be obtained in good to excellent yield by Sm/TiCl4 mediated reductive cleavage of N=N bond in azo compounds and successive acylation in one pot. It offers an alternative method for the synthesis of amides from very simple starting materials directly.

  2. 2',3'-cyclic nucleotide-3'-phosphodiesterase in the central nervous system is fatty-acylated by thioester linkage.

    Agrawal, H C; Sprinkle, T J; Agrawal, D

    1990-07-15

    2',3'-Cyclic nucleotide-3'-phosphodiesterase (CNP1 and CNP2 with Mr of 46,000 and 48,000, respectively) is the major enzyme of central nervous system myelin. It is associated with oligodendroglial plasma membrane and uncompacted myelin (myelin-like fraction), which are in contact with glial cytoplasm. Proteins of the myelin-like fraction were labeled with [3H]palmitic acid in brain slices from 17-day-old rats and immunoprecipitated with anti-CNP antiserum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography of immunoprecipitated material revealed intense acylation of CNP1 and CNP2, and radioactivity was released by hydroxylamine. Palmitic acid was covalently bound to CNP because radioactivity was not removed by extraction of immunoprecipitated CNP with organic solvent or by boiling in sodium dodecyl sulfate and dithiothreitol. However, treatment of immunoprecipitated CNP with (a) hydroxylamine-released palmitohydroxamate and palmitic acid, (b) sodium borohydride-released hexadecanol, and (c) methanolic-KOH-released methyl palmitate. Synthesis, acylation, or transport of CNP was not affected by monensin or colchicine. However, acylation of CNP was inhibited 24-32% by cycloheximide. These results provide conclusive evidence that CNP1 and CNP2 are fatty acid acylated with palmitate through a thioester linkage and is posttranslationally modified sometime after synthesis. PMID:2164018

  3. N-acyl-homoserine lactone uptake and systemic transport in barley rest upon active parts of the plant

    Sieper, T.; Forczek, Sándor; Matucha, Miroslav; Kraemer, P.; Hartmann, A.; Schroeder, P.

    2014-01-01

    Roč. 201, č. 2 (2014), s. 545-555. ISSN 1469-8137 Institutional support: RVO:61389030 Keywords : barley (Hordeum vulgare) * monoclonal antibodies * N-acyl-homoserine lactones (HSLs) Subject RIV: EF - Botanics Impact factor: 6.373, year: 2013

  4. Characterization of a small acyl-CoA-binding protein (ACBP) from Helianthus annuus L. and its binding affinities.

    Aznar-Moreno, Jose A; Venegas-Calerón, Mónica; Du, Zhi-Yan; Garcés, Rafael; Tanner, Julian A; Chye, Mee-Len; Martínez-Force, Enrique; Salas, Joaquín J

    2016-05-01

    Acyl-CoA-binding proteins (ACBPs) bind to acyl-CoA esters and promote their interaction with other proteins, lipids and cell structures. Small class I ACBPs have been identified in different plants, such as Arabidopsis thaliana (AtACBP6), Brassica napus (BnACBP) and Oryza sativa (OsACBP1, OsACBP2, OsACBP3), and they are capable of binding to different acyl-CoA esters and phospholipids. Here we characterize HaACBP6, a class I ACBP expressed in sunflower (Helianthus annuus) tissues, studying the specificity of its corresponding recombinant HaACBP6 protein towards various acyl-CoA esters and phospholipids in vitro, particularly using isothermal titration calorimetry and protein phospholipid binding assays. This protein binds with high affinity to de novo synthetized derivatives palmitoly-CoA, stearoyl-CoA and oleoyl-CoA (Kd 0.29, 0.14 and 0.15 μM respectively). On the contrary, it showed lower affinity towards linoleoyl-CoA (Kd 5.6 μM). Moreover, rHaACBP6 binds to different phosphatidylcholine species (dipalmitoyl-PC, dioleoyl-PC and dilinoleoyl-PC), yet it displays no affinity towards other phospholipids like lyso-PC, phosphatidic acid and lysophosphatidic acid derivatives. In the light of these results, the possible involvement of this protein in sunflower oil synthesis is considered. PMID:26938582

  5. Indium triflate in 1-isobutyl-3-methylimidazolium dihydrogenphosphate: an efficient and green catalytic system for Friedel-Crafts acylation

    Tran, Phuong Hoang; Hoang, Huy Manh; Chau, Duy-Khiem Nguyen;

    2015-01-01

    Indium triflate in the ionic liquid, 1-isobutyl-3-methylimidazolium dihydrogen phosphate ([i-BMIM]H2PO4), was found to show enhanced catalytic activity in the Friedel–Crafts acylation of various aromatic compounds with acid anhydrides. The catalytic system was easily recovered and reused without ...

  6. Securiosides A and B, novel acylated triterpene bisdesmosides with selective cytotoxic activity against M-CSF-stimulated macrophages.

    Kuroda, M; Mimaki, Y; Sashida, Y; Kitahara, M; Yamazaki, M; Yui, S

    2001-02-12

    We report the discovery of securiosides A (1) and B (2), novel acylated triterpene bisdesmosides, isolated from the roots of Securidaca inappendiculata. Securiosides A and B showed potent selective cytotoxic activity against M-CSF-stimulated macrophages and were suggested to have potential as new agents for the treatment of inflammatory diseases such as RA and atherosclerosis. PMID:11212113

  7. Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

    Halavaty, Andrei S. [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Kim, Youngchang [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Minasov, George; Shuvalova, Ludmilla; Dubrovska, Ievgeniia; Winsor, James [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Zhou, Min [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Onopriyenko, Olena; Skarina, Tatiana [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Papazisi, Leka; Kwon, Keehwan; Peterson, Scott N. [Center for Structural Genomics of Infectious Diseases, (United States); J. Craig Venter Institute, Rockville, MD 20850 (United States); Joachimiak, Andrzej [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Savchenko, Alexei [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Anderson, Wayne F., E-mail: wf-anderson@northwestern.edu [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States)

    2012-10-01

    The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS{sub SA}), Vibrio cholerae (AcpS{sub VC}) and Bacillus anthracis (AcpS{sub BA}) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS{sub BA} is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpS{sub BA} may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP.

  8. Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

    The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpSSA), Vibrio cholerae (AcpSVC) and Bacillus anthracis (AcpSBA) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpSBA is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpSBA may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP

  9. Radical recombinations in acetylene-air flames

    Zeegers, P.J.Th.; Alkemade, C.T.J.

    1965-01-01

    In this paper an analysis is given of the behaviour of excess radical concentrations, H, OH and O as a function of height above the reaction zone in premixed acetylene-air flames at 2–200° to 2400°K and 1 atmosphere pressure. The intensity was measured of the Li resonance line which is related to th

  10. Free-radical inactivation of muscle aldolase

    Rabbit muscle aldolase has been shown to be deactivated by addition of irradiated crystals of various sugars and amino acids. Inactivation observed immediately upon dissolution is ascribed to reaction with free radicals, whereas post-dissolution inactivation is ascribed to acid-catalyzed reaction with nonradical radiolysis products. (U.S.)

  11. Lipophilic fluorescent products of free radicals

    Ivica, Josko; Wilhelm, Jiří

    2014-01-01

    Roč. 158, č. 3 (2014), s. 365-372. ISSN 1213-8118 R&D Projects: GA ČR(CZ) GAP303/11/0298 Institutional support: RVO:67985823 Keywords : lipofuscin-like pigments * lipid peroxidation * free radicals * fluorescence Subject RIV: CE - Biochemistry Impact factor: 1.200, year: 2014

  12. Discourses of postmodern epistemology: Radical impetus lost?

    Mueller, Martin

    2006-01-01

    Exhibiting a highly divisive agenda postmodernism has created profound chasms across scientific communities. In development studies its radical impetus has translated into the postdevelopment perspective which violently repudiates the modernist development project. This paper crystallises two distinct discourses of working upon the epistemological raw material of postmodernism: an exclusivist discourse, which reinforces the chasm by isolating postmodernism, and an inclusivist discourse, which...

  13. Identity and Islamic Radicalization in Western Europe

    S.M. Murshed (Syed); S. Pavan (Sara)

    2009-01-01

    textabstractThis paper argues that both socio-economic disadvantage and political factors, such as the West’s foreign policy with regard to the Muslim world, along with historical grievances, play a part in the development of Islamic radicalized collective action in Western Europe. We emphasise the

  14. Designed metalloprotein stabilizes a semiquinone radical.

    Ulas, Gözde; Lemmin, Thomas; Wu, Yibing; Gassner, George T; DeGrado, William F

    2016-04-01

    Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(II) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal-ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol(-1)). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry. PMID:27001731

  15. Radical Chemistry in the Gas Phase

    Alcaraz, Ch.; Fischer, I.; Schröder, Detlef

    New York: John Wiley and Sons, 2012 - (Chatgilialoglu, C.; Studer, A.), s. 477-502 ISBN 978-0-470-97125-3 Grant ostatní: European Research Council(XE) AdG HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : radicals * reactive intermediates * gas phase * photoionization * unimolecular reactions * bimolecular reactions Subject RIV: CF - Physical ; Theoretical Chemistry

  16. Radical Islamism and Migrant Integration in Denmark

    Goli, Marco; Rezaei, Shahamak

    2011-01-01

    for – or consequence of - their societal integration. Conventional wisdom suggests: “The more you associate yourself with the cherished and established goals and means, the more you will disassociate yourself from Radical Islamism”, and vice versa. We believe that, quite surprisingly, an empirical test of this idea...

  17. Designed metalloprotein stabilizes a semiquinone radical

    Ulas, Gözde; Lemmin, Thomas; Wu, Yibing; Gassner, George T.; Degrado, William F.

    2016-04-01

    Enzymes use binding energy to stabilize their substrates in high-energy states that are otherwise inaccessible at ambient temperature. Here we show that a de novo designed Zn(II) metalloprotein stabilizes a chemically reactive organic radical that is otherwise unstable in aqueous media. The protein binds tightly to and stabilizes the radical semiquinone form of 3,5-di-tert-butylcatechol. Solution NMR spectroscopy in conjunction with molecular dynamics simulations show that the substrate binds in the active site pocket where it is stabilized by metal-ligand interactions as well as by burial of its hydrophobic groups. Spectrochemical redox titrations show that the protein stabilized the semiquinone by reducing the electrochemical midpoint potential for its formation via the one-electron oxidation of the catechol by approximately 400 mV (9 kcal mol-1). Therefore, the inherent chemical properties of the radical were changed drastically by harnessing its binding energy to the metalloprotein. This model sets the basis for designed enzymes with radical cofactors to tackle challenging chemistry.

  18. Neglected Side Effects After Radical Prostatectomy

    Frey, Anders Ullmann; Sønksen, Jens; Fode, Mikkel

    2014-01-01

    INTRODUCTION: A series of previously neglected sexually related side effects to radical prostatectomy (RP) has been identified over the recent years. These include orgasm-associated incontinence (OAI), urinary incontinence in relation to sexual stimulation (UISS), altered perception of orgasm, or...

  19. Ultraviolet photodissociation dynamics of the phenyl radical

    Ultraviolet (UV) photodissociation dynamics of jet-cooled phenyl radicals (C6H5 and C6D5) are studied in the photolysis wavelength region of 215-268 nm using high-n Rydberg atom time-of-flight and resonance enhanced multiphoton ionization techniques. The phenyl radicals are produced from 193-nm photolysis of chlorobenzene and bromobenzene precursors. The H-atom photofragment yield spectra have a broad peak centered around 235 nm and are in good agreement with the UV absorption spectra of phenyl. The H + C6H4 product translational energy distributions, P(ET)'s, peak near ∼7 kcal/mol, and the fraction of average translational energy in the total excess energy, T>, is in the range of 0.20-0.35 from 215 to 268 nm. The H-atom product angular distribution is isotropic. The dissociation rates are in the range of 107-108 s-1 with internal energy from 30 to 46 kcal/mol above the threshold of the lowest energy channel H +o-C6H4 (ortho-benzyne), comparable with the rates from the Rice-Ramsperger-Kassel-Marcus theory. The results from the fully deuterated phenyl radical are identical. The dissociation mechanism is consistent with production of H +o-C6H4, as the main channel from unimolecular decomposition of the ground electronic state phenyl radical following internal conversion of the electronically excited state.

  20. DNP with Trityl Radicals in Deuterated Polyethylene

    Wang, Li; Meyer, W.; Berlin, A.; Herick, J.; Hess, C.; Reicherz, G.

    2016-02-01

    Chemically doping with trityl radicals was performed in fully deuterated polyethylene. The behavior of paramagnetic centers has been investigated by ESR X-band spectrometer. The highest deuteron polarization was 8% at 2.5 T and 1 K with a spin concentration of 3 × 1019 spins/g.

  1. Hydroxyl Radical Dosimetry for High Flux Hydroxyl Radical Protein Footprinting Applications Using a Simple Optical Detection Method.

    Xie, Boer; Sharp, Joshua S

    2015-11-01

    Hydroxyl radical protein footprinting (HRPF) by fast photochemical oxidation of proteins (FPOP) is a powerful benchtop tool used to probe protein structure, interactions, and conformational changes in solution. However, the reproducibility of all HRPF techniques is limited by the ability to deliver a defined concentration of hydroxyl radicals to the protein. This ability is impacted by both the amount of radical generated and the presence of radical scavengers in solution. In order to compare HRPF data from sample to sample, a hydroxyl radical dosimeter is needed that can measure the effective concentration of radical that is delivered to the protein, after accounting for both differences in hydroxyl radical generation and nonanalyte radical consumption. Here, we test three radical dosimeters (Alexa Fluor 488, terepthalic acid, and adenine) for their ability to quantitatively measure the effective radical dose under the high radical concentration conditions of FPOP. Adenine has a quantitative relationship between UV spectrophotometric response, effective hydroxyl radical dose delivered, and peptide and protein oxidation levels over the range of radical concentrations typically encountered in FPOP. The simplicity of an adenine-based dosimeter allows for convenient and flexible incorporation into FPOP applications, and the ability to accurately measure the delivered radical dose will enable reproducible and reliable FPOP across a variety of platforms and applications. PMID:26455423

  2. Intracellular signal transduction of PBAN action in the silkworm, Bombyx mori: involvement of acyl CoA reductase.

    Ozawa, R; Matsumoto, S

    1996-03-01

    In the silkworm, Bombyx mori, production of the sex pheromone bombykol is regulated by a neurohormone termed PBAN. We have detected the activity of acyl CoA reductase in the pheromone gland of B. mori by using palmitoyl CoA as a substrate. The acyl CoA reductase requires NADPH, but not NADH, as a proton dono. When the pheromone gland was incubated with the PBAN fragment peptide TKYFSPRLamide, palmitoyl CoA was incorporated and converted into the corresponding C16 alcohols. Radio HPLC analysis revealed that these C16 alcohols were hexadecan-1-ol (81.2%), (Z)-11-hexadecen-1-ol (12.3%), and (E, Z)-10, 12-hexadecadien-1-ol (= bombykol, 6.5%). The production of C16 alcohols in the pheromone gland was inhibited by the known bombykol biosynthesis inhibitors EDTA, LaCl3, W-7, trifluoperazine, p-nitrophenyl phosphate, NaF and compactin. By contrast, when the pheromone gland homogenate was incubated in the presence of palmitoyl CoA and NADPH, production of C16 alcohols was affected by compactin, W-7 and trifluoperazine, but not by EDTA, LaCl3, p-nitrophenyl phosphate and NaF. These results indicate that compactin, W-7 and trifluoperazine directly suppress the step catalyzed by acyl CoA reductase, whereas EDTA, LaCl3, pNPP, and NaF inhibit bombykol production by affecting other biochemical steps in the signal transduction of PBAN action. The present results also imply that PBAN regulates the step catalyzed by acyl CoA reductase and that palmitoyl CoA could be used as a substrate of the acyl CoA reductase that regulates bombykol biosynthesis. PMID:8900596

  3. Pantoea sp. isolated from tropical fresh water exhibiting N-acyl homoserine lactone production.

    Tan, Wen-Si; Muhamad Yunos, Nina Yusrina; Tan, Pui-Wan; Mohamad, Nur Izzati; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity to Pantoea stewartii S9-116, which is a plant pathogen. The isolated Pantoea sp. was confirmed to produce N-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL) through analysis of high resolution mass tandem mass spectrometry. PMID:25197715

  4. Pantoea sp. Isolated from Tropical Fresh Water Exhibiting N-Acyl Homoserine Lactone Production

    Wen-Si Tan

    2014-01-01

    Full Text Available N-Acyl homoserine lactone (AHL serves as signaling molecule for quorum sensing (QS in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity to Pantoea stewartii S9-116, which is a plant pathogen. The isolated Pantoea sp. was confirmed to produce N-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL through analysis of high resolution mass tandem mass spectrometry.

  5. The acyl-CoA binding protein is required for normal epidermal barrier function in mice

    Bloksgaard, Maria; Bek, Signe; Marcher, Ann-Britt;

    2012-01-01

    The acyl-CoA binding protein (ACBP) is a 10 kDa intracellular protein expressed in all eukaryotic species. Mice with targeted disruption of Acbp (ACBP(-/-) mice) are viable and fertile but present a visible skin and fur phenotype characterized by greasy fur and development of alopecia and scaling...... with age. Morphology and development of skin and appendages are normal in ACBP(-/-) mice; however, the stratum corneum display altered biophysical properties with reduced proton activity and decreased water content. Mass spectrometry analyses of lipids from epidermis and stratum corneum of ACBP...... VLC-FFAs via complex phospholipids in the lamellar bodies. Importantly, we show that ACBP(-/-) mice display a ∼50% increased transepidermal water loss compared with ACBP(+/+) mice. Furthermore, skin and fur sebum monoalkyl diacylglycerol (MADAG) levels are significantly increased, suggesting that ACBP...

  6. Acylated glucosylflavones as α-glucosidase inhibitors from Tinospora crispa leaf.

    Chang, Chi-Chih; Ho, Sheau Ling; Lee, Shoei-Sheng

    2015-07-01

    The ethanolic extract of Tinospora crispa leaf had shown inhibitory activity toward α-glucosidase. Bioassay guided fractionation and separation of this extract led to the isolation of 17 flavonoids. Among them, four acylated glycosylflavonoids (6, 8, 9, 15) are new compounds. Their structures were elucidated on the basis of spectroscopic analysis. Among the isolated compounds, isovitexin 2″-(E)-p-coumarate (8) showed the best activity against α-glucosidase with an IC50 value of 4.3±1.4μM. However, isoorientin 2″-(E)-p-coumarate (7), the 3'-hydroxylated 8, is much less active (IC50 35.7μM). Such significant difference was rationalized by CAD study on α-glucosidase. PMID:25999202

  7. Molecular characterization of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

    Gregersen, N; Andresen, B S; Bross, P; Winter, V; Rüdiger, N; Engst, S; Christensen, E; Kelly, D; Strauss, A W; Kølvraa, S

    1991-01-01

    A series of experiments has established the molecular defect in the medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) gene in a family with MCAD deficiency. Demonstration of intra-mitochondrial mature MCAD indistinguishable in size (42.5-kDa) from control MCAD, and of mRNA with the correct...... revealed A985 in genomic DNA from 26 control individuals. The A to G mutation was introduced into an E. coli expression vector producing mutant MCAD, which was demonstrated to be inactive, probably because of the inability to form active tetrameric MCAD. All the experiments are consistent with the...... contention that the G985 mutation, resulting in a lysine to glutamate shift at position 329 in the MCAD polypeptide chain, is the genetic cause of MCAD deficiency in this family. We found the same mutation in homozygous form in 11 out of 12 other patients with verified MCAD deficiency....

  8. Acylated delphinidin glycosides from violet and violet-blue flowers of Clematis cultivars and their coloration.

    Sakaguchi, Keisuke; Kitajima, Junichi; Iwashina, Tsukasa

    2013-11-01

    Three new acylated delphinidin glycosides, delphinidin 3-O-beta-[(2"-trans-caffeoylglucopyranosyl)-(1 --> 2)-(6"-succinylgalactopyranoside)]-7-O-beta-glucopyranoside (1), delphinidin 3-O-beta-[(2"-trans-caffeoylglucopyranosyl)-(1 --> 2)-(6"-trans-caffeoyl-tartaroyl-malonylgalactopyranoside)]-7-O-beta-glucopyranoside (2), and delphinidin 3-O-beta-[(2"-trans-caffeoylglucopyranosyl)-(1 --> 2)-(6"-trans-caffeoyl-tartaroyl-malonylgalactopyranoside)]-3'-O-beta-glucuronopyranoside (3), were isolated from the violet and violet-blue sepals of Clematis cultivars 'Jackmanii Superba' and 'Fujimusume'. The chemical structures of the isolated anthocyanins were determined by LC-MS, characterization of hydrolyzates, and UV, 1H and 13C NMR spectroscopy. The visible absorption spectra of these anthocyanins were compared with those of fresh sepals and crude extracts in pH 5.1 buffer solution. In addition, the co-pigment effect with some kaempferol glycosides and caffeoylglucose was examined. PMID:24427942

  9. Biofilm activity and sludge characteristics affected by exogenous N-acyl homoserine lactones in biofilm reactors.

    Hu, Huizhi; He, Junguo; Liu, Jian; Yu, Huarong; Zhang, Jie

    2016-07-01

    This study verified the effect of N-acyl homoserine lactone (AHL) concentrations on mature biofilm systems. Three concentrations of an AHL mixture were used in the batch test. Introducing of 5nM AHLs significantly increased biofilm activity and increased sludge characteristics, which resulted in better pollutant removal performance, whereas exogenous 50nM and 500nM AHLs limited pollutant removal, especially COD and nitrogen removal. To further identify how exogenous signal molecular affects biofilm system nitrogen removal, analyzing of nitrifying bacteria through real-time polymerase chain reaction (RT-PCR) revealed that these additional signal molecules affect nitrifying to total bacteria ratio. In addition, the running state of the system was stable during 15days of operation without an AHL dose, which suggests that the changes in the system due to AHL are irreversible. PMID:27030953

  10. Supramolecular arrangement in mono and bi-camphor acyl hydrazones: A structural study

    Galvão, Adelino M.; Carvalho, M. Fernanda N. N.; Ferreira, Ana S. D.

    2016-03-01

    New acyl hydrazones were synthesized by condensation with camphorquinone aiming at extending the range of applications of the biologically active camphor compounds and structural studies by XRD, 1H-NMR and IR were used in conjunction with advanced computational methodologies to understand the new structural chemistry enabled by the conjugation of the camphor ketone group to the hydrazone Ndbnd C double bond. In particular, were analysed supramolecular arrangements either by hydrogen bonding to water molecules or electrostatic interactions with non protic solvents. The relative stability of all conformers (E/Z) prompted by the hydrazone bond was addressed by state of the art methods such as CR-CCSD(T) and their inter-conversion in both S0 and S1 by CR-EOM-CCSD(T).

  11. N-Acyl Dehydrotyrosines, Tyrosinase Inhibitors from the Marine Bacterium Thalassotalea sp. PP2-459.

    Deering, Robert W; Chen, Jianwei; Sun, Jiadong; Ma, Hang; Dubert, Javier; Barja, Juan L; Seeram, Navindra P; Wang, Hong; Rowley, David C

    2016-02-26

    Thalassotalic acids A-C and thalassotalamides A and B are new N-acyl dehydrotyrosine derivatives produced by Thalassotalea sp. PP2-459, a Gram-negative bacterium isolated from a marine bivalve aquaculture facility. The structures were elucidated via a combination of spectroscopic analyses emphasizing two-dimensional NMR and high-resolution mass spectrometric data. Thalassotalic acid A (1) displays in vitro inhibition of the enzyme tyrosinase with an IC50 value (130 μM) that compares favorably to the commercially used control compounds kojic acid (46 μM) and arbutin (100 μM). These are the first natural products reported from a bacterium belonging to the genus Thalassotalea. PMID:26824128

  12. Production of acylated homoserine lactones by psychrotrophic members of the Enterobacteriaceae isolated from foods

    Gram, Lone; Christensen, A.B.; Flodgaard, Lars; Molin, Søren; Givskov, Michael Christian

    1999-01-01

    Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules. These signals play important roles in several pathogenic and symbiotic bacteria. The following study was undertaken to investigate whether AHLs are...... produced by bacteria found in food at temperatures and NaCl conditions commercially used for food preservation and storage. A minimum of 116 of 154 psychrotrophic Enterobacteriaceae strains isolated from cold-smoked salmon or vacuum-packed chilled meat produced AHLs. Analysis by thin-layer chromatography...... indicated that N-3-oxohexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat. AHL-positive strains cultured at 5 degrees C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 10(6) CFU/ml. AHLs were...

  13. Understanding the control of acyl flux through the lipid metabolic network of plant oil biosynthesis.

    Bates, Philip D

    2016-09-01

    Plant oil biosynthesis involves a complex metabolic network with multiple subcellular compartments, parallel pathways, cycles, and pathways that have a dual function to produce essential membrane lipids and triacylglycerol. Modern molecular biology techniques provide tools to alter plant oil compositions through bioengineering, however with few exceptions the final composition of triacylglycerol cannot be predicted. One reason for limited success in oilseed bioengineering is the inadequate understanding of how to control the flux of fatty acids through various fatty acid modification, and triacylglycerol assembly pathways of the lipid metabolic network. This review focuses on the mechanisms of acyl flux through the lipid metabolic network, and highlights where uncertainty resides in our understanding of seed oil biosynthesis. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27003249

  14. Evaluation of Enoyl-Acyl Carrier Protein Reductase Inhibitors as Pseudomonas aeruginosa Quorum-Quenching Reagents

    Søren Molin

    2010-02-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen which is responsible for a wide range of infections. Production of virulence factors and biofilm formation by P. aeruginosa are partly regulated by cell-to-cell communication quorum-sensing systems. Identification of quorum-quenching reagents which block the quorum-sensing process can facilitate development of novel treatment strategies for P. aeruginosa infections. We have used molecular dynamics simulation and experimental studies to elucidate the efficiencies of two potential quorum-quenching reagents, triclosan and green tea epigallocatechin gallate (EGCG, which both function as inhibitors of the enoyl-acyl carrier protein (ACP reductase (ENR from the bacterial type II fatty acid synthesis pathway. Our studies suggest that EGCG has a higher binding affinity towards ENR of P. aeruginosa and is an efficient quorum-quenching reagent. EGCG treatment was further shown to be able to attenuate the production of virulence factors and biofilm formation of P. aeruginosa.

  15. A Zeolite Imidazolate Framework ZIF-8 Catalyst for Friedel-Crafts Acylation

    LienT.L.NGUYEN; Ky K.A.LE; Nam T.S.PHAN

    2012-01-01

    A zeolite imidazolate framework,ZIF-8,was synthesized and characterized by dynamic laser light scattering,X-ray powder diffraction,scanning electron microscopy,transmission electron microscopy,thermogravimetric analysis,Fourier transform infrared,atomic absorption spectrophotometry,and nitrogen adsorption measurements.The ZIF-8 was highly crystalline and porous with a surface area of over 1600 m2/g.Friedel-Crafts acylation of anisole and benzoyl chloride proceeded well in the presence of ZIF-8 (2-6 mol%) without the need for an inert atmosphere.The reaction afforded a selectivity of 93%-95% to the p-isomer.The solid catalyst can be separated from the reaction mixture by simple centrifugation and reused without significant degradation in catalytic activity.There was no leaching of active acid species into the reaction solution.

  16. Prolonged QTc interval in association with medium-chain acyl-coenzyme A dehydrogenase deficiency.

    Wiles, Jason R; Leslie, Nancy; Knilans, Timothy K; Akinbi, Henry

    2014-06-01

    Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is the most common disorder of mitochondrial fatty acid oxidation. We report a term male infant who presented at 3 days of age with hypoglycemia, compensated metabolic acidosis, hypocalcemia, and prolonged QTc interval. Pregnancy was complicated by maternal premature atrial contractions and premature ventricular contractions. Prolongation of the QTc interval resolved after correction of metabolic derangements. The newborn screen was suggestive for MCAD deficiency, a diagnosis that was confirmed on genetic analysis that showed homozygosity for the disease-associated missense A985G mutation in the ACADM gene. This is the first report of acquired prolonged QTc in a neonate with MCAD deficiency, and it suggests that MCAD deficiency should be considered in the differential diagnoses of acute neonatal illnesses associated with electrocardiographic abnormality. We review the clinical presentation and diagnosis of MCAD deficiency in neonates. PMID:24799540

  17. Intracellular long-chain acyl CoAs activate TRPV1 channels.

    Yi Yu

    Full Text Available TRPV1 channels are an important class of membrane proteins that play an integral role in the regulation of intracellular cations such as calcium in many different tissue types. The anionic phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2 is a known positive modulator of TRPV1 channels and the negatively charged phosphate groups interact with several basic amino acid residues in the proximal C-terminal TRP domain of the TRPV1 channel. We and other groups have shown that physiological sub-micromolar levels of long-chain acyl CoAs (LC-CoAs, another ubiquitous anionic lipid, can also act as positive modulators of ion channels and exchangers. Therefore, we investigated whether TRPV1 channel activity is similarly regulated by LC-CoAs. Our results show that LC-CoAs are potent activators of the TRPV1 channel and interact with the same PIP2-binding residues in TRPV1. In contrast to PIP2, LC-CoA modulation of TRPV1 is independent of Ca2+i, acting in an acyl side-chain saturation and chain-length dependent manner. Elevation of LC-CoAs in intact Jurkat T-cells leads to significant increases in agonist-induced Ca2+i levels. Our novel findings indicate that LC-CoAs represent a new fundamental mechanism for regulation of TRPV1 channel activity that may play a role in diverse cell types under physiological and pathophysiological conditions that alter fatty acid transport and metabolism such as obesity and diabetes.

  18. Zomepirac Acyl Glucuronide Is Responsible for Zomepirac-Induced Acute Kidney Injury in Mice.

    Iwamura, Atsushi; Watanabe, Katsuhito; Akai, Sho; Nishinosono, Tsubasa; Tsuneyama, Koichi; Oda, Shingo; Kume, Toshiyuki; Yokoi, Tsuyoshi

    2016-07-01

    Glucuronidation, an important phase II metabolic route, is generally considered to be a detoxification pathway. However, acyl glucuronides (AGs) have been implicated in the toxicity of carboxylic acid drugs due to their electrophilic reactivity. Zomepirac (ZP) was withdrawn from the market because of adverse effects such as renal toxicity. Although ZP is mainly metabolized to acyl glucuronide (ZP-AG) by UDP-glucuronosyltransferase, the role of ZP-AG in renal toxicity is unknown. In this study, we established a ZP-induced kidney injury mouse model by pretreatment with tri-o-tolyl phosphate (TOTP), a nonselective esterase inhibitor, and l-buthionine-(S,R)-sulfoximine (BSO), a glutathione synthesis inhibitor. The role of ZP-AG in renal toxicity was investigated using this model. The model showed significant increases in blood urea nitrogen (BUN) and creatinine (CRE), but not alanine aminotransferase. The ZP-AG concentrations were elevated by cotreatment with TOTP in the plasma and liver and especially in the kidney. The ZP-AG concentrations in the kidney correlated with values for BUN and CRE. Upon histopathological examination, vacuoles and infiltration of mononuclear cells were observed in the model mouse. In addition to immune-related responses, oxidative stress markers, such as the glutathione/disulfide glutathione ratio and malondialdehyde levels, were different in the mouse model. The suppression of ZP-induced kidney injury by tempol, an antioxidant agent, suggested the involvement of oxidative stress in ZP-induced kidney injury. This is the first study to demonstrate that AG accumulation in the kidney by TOTP and BSO treatment could explain renal toxicity and to show the in vivo toxicological potential of AGs. PMID:27112166

  19. NMR Solution Structure and Biophysical Characterization of Vibrio harveyi Acyl Carrier Protein A75H

    Chan, David I.; Chu, Byron C. H.; Lau, Cheryl K. Y.; Hunter, Howard N.; Byers, David M.; Vogel, Hans J.

    2010-01-01

    Bacterial acyl carrier protein (ACP) is a highly anionic, 9 kDa protein that functions as a cofactor protein in fatty acid biosynthesis. Escherichia coli ACP is folded at neutral pH and in the absence of divalent cations, while Vibrio harveyi ACP, which is very similar at 86% sequence identity, is unfolded under the same conditions. V. harveyi ACP adopts a folded conformation upon the addition of divalent cations such as Ca2+ and Mg2+ and a mutant, A75H, was previously identified that restores the folded conformation at pH 7 in the absence of divalent cations. In this study we sought to understand the unique folding behavior of V. harveyi ACP using NMR spectroscopy and biophysical methods. The NMR solution structure of V. harveyi ACP A75H displays the canonical ACP structure with four helices surrounding a hydrophobic core, with a narrow pocket closed off from the solvent to house the acyl chain. His-75, which is charged at neutral pH, participates in a stacking interaction with Tyr-71 in the far C-terminal end of helix IV. pH titrations and the electrostatic profile of ACP suggest that V. harveyi ACP is destabilized by anionic charge repulsion around helix II that can be partially neutralized by His-75 and is further reduced by divalent cation binding. This is supported by differential scanning calorimetry data which indicate that calcium binding further increases the melting temperature of V. harveyi ACP A75H by ∼20 °C. Divalent cation binding does not alter ACP dynamics on the ps-ns timescale as determined by 15N NMR relaxation experiments, however, it clearly stabilizes the protein fold as observed by hydrogen-deuterium exchange studies. Finally, we demonstrate that the E. coli ACP H75A mutant is similarly unfolded as wild-type V. harveyi ACP, further stressing the importance of this particular residue for proper protein folding. PMID:20659901

  20. Structure of an acyl-enzyme intermediate during catalysis: (Guanidinobenzoyl)trypsin

    The crystal and molecular structure of trypsin at a transiently stable intermediate step during catalysis has been determined by X-ray diffraction methods. Bovine trypsin cleaved the substrate p-nitrophenyl p-guanidinobenzoate during crystallization under conditions in which the acyl-enzyme intermediate, (guanidinobenzoyl)trypsin, was stable. Diffraction data were measured with a FAST (Enraf Nonius) diffractometer. The structure was refined to a crystallographic residual of R = 0.16 for data in the resolution range 7.0-2.0 angstrom. The refined model of (guanidinobenzoyl)trypsin provides insight into the structural basis for its slow rate of deacylation, which in solution at 25 degree C and pH 7.4 exhibits a t1/2 of 12h. This allows formation of energetically favorable H bonds and an ion pair between the carboxylate of Asp-189 and the guanidino group of the substrate. This movement is dictated by the rigidity of the aromatic ring in guanidinobenzoate -- model-building indicates that this should not occur when arginine, with its more flexible aliphatic backbone, forms the ester bond with Ser-195. As a consequence, highly ordered water molecules in the active site are no longer close enough to the scissile ester bond to serve as potential nucleophiles for hydrolysis. Coupled with an apparent 35% decrease in the overall temperature factor of the acyl-enzyme relative to the native structure, the tight packing and rigidity of all atoms in the active site, including solvent, prevent disordered water molecules from easily approaching the carbonyl carbon atom via diffusion

  1. Mycobacterium tuberculosis acyl carrier protein synthase adopts two different pH-dependent structural conformations

    Gokulan, Kuppan; Aggarwal, Anup; Shipman, Lance [Texas A& M University, College Station, TX 77843-3474 (United States); Besra, Gurdyal S. [University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sacchettini, James C., E-mail: sacchett@tamu.edu [Texas A& M University, College Station, TX 77843-3474 (United States)

    2011-07-01

    Bacterial acyl carrier protein synthase plays an essential role in the synthesis of fatty acids, nonribosomal peptides and polyketides. In Mycobacterium tuberculosis, AcpS or group I phosphopentatheine transferase exhibits two different structural conformations depending upon the pH. The crystal structures of acyl carrier protein synthase (AcpS) from Mycobacterium tuberculosis (Mtb) and Corynebacterium ammoniagenes determined at pH 5.3 and pH 6.5, respectively, are reported. Comparison of the Mtb apo-AcpS structure with the recently reported structure of the Mtb AcpS–ADP complex revealed that AcpS adopts two different conformations: the orthorhombic and trigonal space-group structures show structural differences in the α2 helix and in the conformation of the α3–α4 connecting loop, which is in a closed conformation. The apo-AcpS structure shows electron density for the entire model and was obtained at lower pH values (4.4–6.0). In contrast, at a higher pH value (6.5) AcpS undergoes significant conformational changes, resulting in disordered regions that show no electron density in the AcpS model. The solved structures also reveal that C. ammoniagenes AcpS undergoes structural rearrangement in two regions, similar to the recently reported Mtb AcpS–ADP complex structure. In vitro reconstitution experiments show that AcpS has a higher post-translational modification activity between pH 4.4 and 6.0 than at pH values above 6.5, where the activity drops owing to the change in conformation. The results show that apo-AcpS and AcpS–ADP adopt different conformations depending upon the pH conditions of the crystallization solution.

  2. Free Radicals in Superfluid Liquid Helium Nanodroplets: A Pyrolysis Source for the Production of Propargyl Radical

    Küpper, J; Miller, R E; K\\"upper, Jochen; Merritt, Jeremy M.; Miller, Roger E.

    2002-01-01

    An effusive pyrolysis source is described for generating a continuous beam of radicals under conditions appropriate for the helium droplet pick-up method. Rotationally resolved spectra are reported for the $\

  3. THE RADICAL ONLINE: INDIVIDUAL RADICALIZATION PROCESSES AND THE ROLE OF THE INTERNET

    Daniel Koehler

    2014-12-01

    Full Text Available This paper examines in detail the role of the Internet in individual radicalization processes of eight German former right-wing extremists. Applying Grounded Theory methodology the qualitative interviews were analyzed in several coding and re-coding phases. The findings are integrated into the existing literature afterwards. Besides well known factors, such as more effective communication, anonymity and better networking opportunities, this study found evidence that the Internet is a major driving factor to establish and foster the development of radical contrast societies (cf. Koehler, 2015 transmitting radical and violent ideologies and translating them into political activism. As a venue for information exchange, ideological development and training, the individual radicalization process was characteristically shaped or even made possible through the Internet. This paper also shows the high value of qualitative research regarding the topic in contrast to usually employed quantitative analysis of webpage content.

  4. Classical radical hysterectomy and nerve-sparing radical hysterectomy in the treatment of cervical cancer

    Marcin Makowski; Marek Nowak; Marian Szpakowski; Jacek Władziński; Anna Serwach-Nowińska; Łukasz Janas; Jacek R. Wilczyński

    2014-01-01

    Aim of the study: To compare Piver III radical hysterectomy (RH) with nerve-sparing radical hysterectomy (NSRH) for cervical cancer patients in terms of postoperative physiology of pelvic autonomic nerves and perioperative complications. Material and methods : Seventy-three consecutive patients with invasive cervical cancer underwent RH (53 cases) or NSRH (20 cases) from 2001 to 2012 at the Department of Gynecology and Gynecologic Oncology of Polish Mother’s Memorial Hospital – Research...

  5. Spectroscopy of free radicals and radical containing entrance-channel complexes in superfluid helium nanodroplets

    Küpper, J.; Merritt, J.

    2007-01-01

    The spectroscopy of free radicals and radical containing entrance-channel complexes embedded in superfluid helium nano-droplets is reviewed. The collection of dopants inside individual droplets in the beam represents a micro-canonical ensemble, and as such each droplet may be considered an isolated cryo-reactor. The unique properties of the droplets, namely their low temperature (0.4 K) and fast cooling rates ( ~ 1016 K s-1)provides novel opportunities for the formation and high-resolution st...

  6. Environmentally Persistent Free Radicals (EPFRs) - 2. Are Free Hydroxyl Radicals Generated in Aqueous Solutions?

    Khachatryan, Lavrent; Dellinger, Barry

    2011-01-01

    A chemical spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), in conjunction with electron paramagnetic resonance (EPR) spectroscopy was employed to measure the production of hydroxyl radical (.OH) in aqueous suspensions of 5% Cu(II)O/silica (3.9% Cu) particles containing environmentally persistent free radicals (EPFRs) of 2-monochlorophenol (2-MCP). The results indicate: 1) a significant differences in accumulated DMPO-OH adducts between EPFR containing particles and non-EPFR control sample...

  7. A novel approach for over-expression, characterization, and isotopic enrichment of a homogeneous species of acyl carrier protein from Plasmodium falciparum

    Sharma, Shailendra Kumar; Modak, Rahul; Sharma, Shilpi; Sharma, Alok Kumar; Sarma, Siddhartha P; Surolia, Avadhesha; Surolia, Namita

    2005-01-01

    Acyl carrier protein (ACP) plays a central role in fatty acid biosynthesis by transferring the acyl groups from one enzyme to another for the completion of the fatty acid synthesis cycle. Holo-ACP is the obligatory substrate for the synthesis of acyl-ACPs which act as the carrier and donor for various metabolic reactions. Despite its interactions with numerous proteins in the cell, its mode of interaction is poorly understood. Here, we report the over-expression of PfACP in minimal medium sol...

  8. Role of oxygen free radicals in patients with acute pancreatitis

    Park, Byung Kyu; Chung, Jae Bock; Lee, Jin Heon; Suh, Jeong Hun; Park, Seung Woo; Song, Si Young; Kim, Hyeyoung; Kim, Kyung Hwan; Kang, Jin Kyung

    2003-01-01

    AIM: The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis.

  9. Free radicals, antioxidants and functional foods: Impact on human health

    Lobo, V.; Patil, A.; A Phatak; N Chandra

    2010-01-01

    In recent years, there has been a great deal of attention toward the field of free radical chemistry. Free radicals reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress...

  10. The Serbian Radical movement 1881-1903: A historical aspect

    Protić Milan St.

    2005-01-01

    Focusing on the initial stage (until 1903) of the Serbian Radical movement the paper attempts to delineate and explicate the main phases of its political maturation. In its initial stage Serbian Radicalism passed through several significant phases. The earliest phase (1869-80) may be named the period of rudimentary Radicalism. The movement was unorganized and oscillated between the ideas of socialism, anarchism and peasant democracy. The year 1881 saw the founding of the Radical Party as the ...

  11. Synthesis of glycopolymer architectures by reversible-deactivation radical polymerization

    Ali Ghadban; Luca Albertin

    2013-01-01

    This review summarizes the state of the art in the synthesis of well-defined glycopolymers by Reversible-Deactivation Radical Polymerization (RDRP) from its inception in 1998 until August 2012. Glycopolymers architectures have been successfully synthesized with four major RDRP techniques: Nitroxide-mediated radical polymerization (NMP), cyanoxyl-mediated radical polymerization (CMRP), atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polym...

  12. Inguinal hernia developed after radical retropubic surgery for prostate cancer

    Chung, Choon Sik; Jeong, Gyu Young; Kim, Seung Han; Lee, Dong Keun

    2013-01-01

    Purpose In this retrospective study, we aimed to compare the clinical characteristics of inguinal hernia developed after radical retropubic surgery for prostate cancer to the hernia without previous radical prostatectomy. Methods Twenty-three patients (group A) who had radical retropubic surgery for prostate cancer underwent laparoscopic or open tension-free inguinal hernia repair from March 2007 to February 2011. Nine hundred and forty patients (group B) without previous radical retropubic s...

  13. Hybrid radical energy storage device and method of making

    Gennett, Thomas; Ginley, David S.; Braunecker, Wade; Ban, Chunmei; Owczarczyk, Zbyslaw

    2016-04-26

    Hybrid radical energy storage devices, such as batteries or electrochemical devices, and methods of use and making are disclosed. Also described herein are electrodes and electrolytes useful in energy storage devices, for example, radical polymer cathode materials and electrolytes for use in organic radical batteries.

  14. Radical radiotherapy for carcinoma of the vulva

    Slevin, N.J.; Pointon, R.C.S.

    1989-02-01

    A study was made of 58 patients with carcinoma of the vulva treated by radical radiotherapy between 1965 and 1982. The choice of treatment technique was influenced by site and extent of disease as well as the general condition of the patient. The crude 5-year survival was 26% (15/58). Local control was achieved in 40% of cases and was associated with tumour size of 4 cm or less. Radionecrosis occurred in nine cases but none of these required surgical intervention. Surgery remains the treatment of choice for carcinoma of the vulva. This report emphasizes that radical radiotherapy has a curative potential in those cases considered unsuitable for surgery and that the necrosis type and rate are within the limits of acceptable morbidity.

  15. Radical radiotherapy for carcinoma of the vulva

    A study was made of 58 patients with carcinoma of the vulva treated by radical radiotherapy between 1965 and 1982. The choice of treatment technique was influenced by site and extent of disease as well as the general condition of the patient. The crude 5-year survival was 26% (15/58). Local control was achieved in 40% of cases and was associated with tumour size of 4 cm or less. Radionecrosis occurred in nine cases but none of these required surgical intervention. Surgery remains the treatment of choice for carcinoma of the vulva. This report emphasizes that radical radiotherapy has a curative potential in those cases considered unsuitable for surgery and that the necrosis type and rate are within the limits of acceptable morbidity. (author)

  16. Editorial: RADICALISM AND POLITICS OF RELIGION

    Editorial Al-Jami'ah: Journal of Islamic Studies

    2008-02-01

    Full Text Available Radical Islamism has become the “sexiest” issue in the international scholarship of religion since the September 11 tragedy in 2001. It has been associated with a number of terrorist attacks not only in the West but also in Muslim countries. Every single of radical Islamism has caught the interest of not only scholars and policy makers but also general public. Interestingly, the general assumption that religion is the source of peace has been seriously challenged, not by non-religious communities, but by the violent practices of particular religious groups, however small they are. Indeed, there are certain groups striving for Islam but by using acts which could give awful image on Islam itself and against humanity.

  17. EPR study of free radicals in bread

    Yordanov, Nicola D.; Mladenova, Ralitsa

    2004-05-01

    The features of the recorded EPR spectra of paramagnetic species formed in bread and rusk are reported. The appearance of free radicals in them is only connected with their thermal treatment since the starting materials (flour and grains) exhibit very weak EPR signal. The obtained EPR spectra are complex and indicate that: (i) the relative number of paramagnetic species depends on the temperature and treating time of the raw product; (ii) the g-values are strongly temperature dependent with a tendency to coincide at t≥220 °C. Because of the relatively low (150-220 °C) temperature of thermal treatment, the studied free radicals can be assumed to appear in the course of the browning (Maillard) reaction and not to the carbonization of the material.

  18. Anion photoelectron spectroscopy of radicals and clusters

    Travis, Taylor R.

    1999-12-16

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

  19. Enhancement of free fatty acid production in Saccharomyces cerevisiae by control of fatty acyl-CoA metabolism.

    Chen, Liwei; Zhang, Jianhua; Lee, Jaslyn; Chen, Wei Ning

    2014-08-01

    Production of biofuels derived from microbial fatty acids has attracted great attention in recent years owing to their potential to replace petroleum-derived fuels. To be cost competitive with current petroleum fuel, flux toward the direct precursor fatty acids needs to be enhanced to approach high yields. Herein, fatty acyl-CoA metabolism in Saccharomyces cerevisiae was engineered to accumulate more free fatty acids (FFA). For this purpose, firstly, haploid S. cerevisiae double deletion strain △faa1△faa4 was constructed, in which the genes FAA1 and FAA4 encoding two acyl-CoA synthetases were deleted. Then the truncated version of acyl-CoA thioesterase ACOT5 (Acot5s) encoding Mus musculus peroxisomal acyl-CoA thioesterase 5 was expressed in the cytoplasm of the strain △faa1△faa4. The resulting strain △faa1△faa4 [Acot5s] accumulated more extracellular FFA with higher unsaturated fatty acid (UFA) ratio as compared to the wild-type strain and double deletion strain △faa1△faa4. The extracellular total fatty acids (TFA) in the strain △faa1△faa4 [Acot5s] increased to 6.43-fold as compared to the wild-type strain during the stationary phase. UFA accounted for 42 % of TFA in the strain △faa1△faa4 [Acot5s], while no UFA was detected in the wild-type strain. In addition, the expression of Acot5s in △faa1△faa4 restored the growth, which indicates that FFA may not be the reason for growth inhibition in the strain △faa1△faa4. RT-PCR results demonstrated that the de-repression of fatty acid synthesis genes led to the increase of extracellular fatty acids. The study presented here showed that through control of the acyl-CoA metabolism by deleting acyl-CoA synthetase and expressing thioesterase, more FFA could be produced in S. cerevisiae, demonstrating great potential for exploitation in the platform of microbial fatty acid-derived biofuels. PMID:24769906

  20. Radical Scavenging Effects of Different Veronica species

    Ummuhan Şebnem Harput; Yasin Genç; Newaj Khan; İclal Saracoglu

    2011-01-01

    It is well known that the excessive production of reactive oxygen species is hazardous for living organisms and damages major cellular constituents such as DNA, lipid and protein. To find new products reducing free radical damage is very important researches in recent pharmaceutical investigations. Considering this information, fourteen Veronica species are decided to research in the view point of their antioxidant capacity and the chemical content. Water extracts of the plants were tested fo...