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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. 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...

  8. 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

  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. Radical prostatectomy - discharge

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

  5. 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

  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 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...

  13. 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...

  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. 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)

  7. 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...

  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. 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.

  12. 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 ...

  13. 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)

  14. 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)

  15. 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)

  16. 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

  17. 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.

  18. 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...

  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. 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

  5. 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

  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. 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.

  10. 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.

  11. 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

  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. 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

  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. 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.

  5. 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

  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. 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...

  16. 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.

  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. 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

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

    Jerga, Agoston; Rock, Charles O

    2009-06-01

    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

  20. 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

  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. 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

  4. 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...

  5. 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...

  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. 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.

  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. 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

  14. 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.

  15. 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

  16. 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...

  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. 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...

  7. 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.

  8. 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

  9. 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

  10. 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

  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. 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...

  1. 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.

  2. 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

  3. 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...

  4. 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...

  5. 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....

  6. 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...

  7. 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

  8. 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

  9. 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

  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

    2010-04-01

    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.

  18. 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.

  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. 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

  4. 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

  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. 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.

  9. 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

  10. 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

  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. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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...

  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. 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...

  5. 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.

  6. 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

  7. 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

  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. 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.

  10. 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

  11. 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

  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. 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...

  14. 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

  15. 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 ...

  16. 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.

  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. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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)

  3. 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...

  4. 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)

  5. 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)

  6. 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...

  7. 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....

  8. 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.

  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. 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...

  11. 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.

  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. 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.

  14. 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

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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

  2. 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

  3. 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...

  4. 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

  5. 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...

  6. 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.

  7. 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

  8. 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...

  9. 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...

  10. 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.