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Sample records for acyl groups separated

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

    Science.gov (United States)

    Head group acylation of monogalactosyldiacylglycerol is a plant lipid modification occurring during bacterial infection. Little is known about the range of stresses that induce this lipid modification, the molecular species induced, and the function of the modification. Lipidomic analysis using trip...

  2. Kinetic and structural basis for acyl-group selectivity and NAD+-dependence in Sirtuin-catalyzed deacylation

    Science.gov (United States)

    Thelen, Julie N.; Ito, Akihiro; Yoshida, Minoru; Denu, John M.

    2015-01-01

    Acylation of lysine is an important protein modification regulating diverse biological processes. It was recently demonstrated that members of the human Sirtuin family are capable of catalyzing long-chain deacylation, in addition to the well-known NAD+-dependent deacetylation activity.1 Here we provide a detailed kinetic and structural analysis that describes the interdependence of NAD+ and acyl-group length for a diverse series of human Sirtuins, SIRT1, SIRT2, SIRT3 and SIRT6. Steady-state and rapid-quench kinetic analyses indicated that differences in NAD+ saturation and susceptibility to nicotinamide inhibition reflect unique kinetic behavior displayed by each Sirtuin and depend on acyl-substrate chain length. Though the rate of nucleophilic attack of the 2′-hydroxyl on the C1′-O-alkylimidate intermediate varies with acyl substrate chain length, this step remains rate-determining for SIRT2 and SIRT3; however for SIRT6, this step is no longer rate-limiting for long-chain substrates. Co-crystallization of SIRT2 with myristoylated peptide and NAD+ yielded a co-complex structure with reaction product 2′-O-myristoyl-ADP-ribose, revealing a latent hydrophobic cavity to accommodate the long chain acyl group, and suggesting a general mechanism for long chain deacylation. Comparing two separately solved co-complex structures containing either a myristoylated peptide or 2′-O-myristoyl-ADP-ribose indicate there are conformational changes at the myristoyl-ribose linkage with minimal structural differences in the enzyme active site. During the deacylation reaction, the fatty acyl group is held in a relatively fixed position. We describe a kinetic and structural model to explain how various Sirtuins display unique acyl-substrate preferences and how different reaction kinetics influence NAD+ dependence. The biological implications are discussed. PMID:25897714

  3. Enhanced separation and analysis procedure reveals production of tri-acylated mannosylerythritol lipids by Pseudozyma aphidis.

    Science.gov (United States)

    Goossens, Eliane; Wijnants, Marc; Packet, Dirk; Lemière, Filip

    2016-11-01

    Mannosylerythritol lipids (MELs) are one of the most promising biosurfactants because of their high fermentation yields (>100 g l -1 ) and during the last two decades they have gained a lot of attention due to their interesting self-assembling properties and biological activities. In this study, MELs were produced by fed-batch bioreactor fermentation of rapeseed oil with Pseudozyma aphidis MUCL 27852. This high-level MEL-producing yeast secretes four conventional MEL structures, -A, -B, -C and -D, which differ in their degree of acetylation. During our research, unknown compounds synthesized by P. aphidis were detected by thin-layer chromatography. The unknown compounds were separated by flash chromatography and identified as tri-acylated MELs by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The third fatty acid chain on the tri-acylated MELs was positioned on the primary alcohol of the erythritol moiety and comprised long-chain acids, mainly oleic and linoleic acid, which are not found in conventional di-acylated MELs. Furthermore, the LC-MS analysis time of conventional MELs was reduced to almost one-third by switching from HPLC-MS/MS to ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Provided optimization of the fermentation yield, P. aphidis could be an interesting novel producer of tri-acylated MELs and, thereby expand the supply and applicability of biosurfactants.

  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.

    Science.gov (United States)

    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. © 2013 Scandinavian Plant Physiology Society.

  5. CYCLICAL SUBNORMAL SEPARATION IN A-GROUPS

    African Journals Online (AJOL)

    :-at are split extensions of certain abelian p-groups by a metabelian pi-group, to satisfy the cyclic a1 subnormal separation condition. There is also a result which shows that A-groups with elementary abelian Sylow subgroups are. :icl~cally separated. KEYWORD: A-groups, Cyclical~Subnormal Separation, CS,-groups.

  6. Enzymatic Resolution and Separation of Secondary Alcohols Based on Fatty Esters as Acylating Agents

    Science.gov (United States)

    Monteiro, Carlos M.; Afonso, Carlos A. M.; Lourenco, Nuno M. T.

    2010-01-01

    The enzymatic resolution of "rac"-1-phenylethanol using ethyl myristate as acylating agent and solvent and "Candida antarctica" lipase B (CAL-B) as biocatalyst was demonstrated with catalyst and medium reuse. Both enantiomers of 1-phenylethanol were isolated by sequential enzymatic reactions and product distillations. From the first enzymatic…

  7. Summary of the separations breakout group

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, R. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    The Separations Breakout Group reviewed the wide spectrum of separations technologies available for application to ADTT systems. Separations processes play a key role in areas associated with preparation of feed materials for introduction into ADTT, removal of fission products and other transmutation byproducts that build into the fuel during operation, and in the preparation of wastes ({open_quotes}polishing{close_quotes}) for discharge from ADTT systems so as to meet appropriate waste disposal criteria. General separations technologies addressed by the group included aqueous, fluoride salt, and chloride salt approaches.

  8. A chemoenzymatic route to mannosamine derivatives bearing different N-acyl groups

    Czech Academy of Sciences Publication Activity Database

    Kristová, Veronika; Martínková, Ludmila; Hušáková, Lucie; Kuzma, Marek; Rauvolfová, Jana; Kavan, D.; Pompach, P.; Bezouška, K.; Křen, Vladimír

    2005-01-01

    Roč. 115, - (2005), s. 157-166 ISSN 0168-1656 R&D Projects: GA ČR GA524/00/1275; GA MŠk OC D25.001 Keywords : rhodoccus equi * n-acylated 2-amino-2-deoxy-d-glukosamines n-acylated 2-amino 2-deoxy-d-mannosamines Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  9. A chemoenzymatic route to mannosamine derivatives bearing different N-acyl groups

    Czech Academy of Sciences Publication Activity Database

    Kristová, Veronika; Martínková, Ludmila; Hušáková, Lucie; Kuzma, Marek; Rauvolfová, Jana; Kavan, D.; Pompach, Petr; Bezouška, Karel; Křen, Vladimír

    2005-01-01

    Roč. 115, - (2005), s. 157-166 ISSN 0168-1656 R&D Projects: GA ČR GA524/00/1275; GA MŠk OC D25.001 Institutional research plan: CEZ:AV0Z50200510 Keywords : rhodococcus equi * N-Acylated 2-amino-2-deoxy-D-glucosamines Subject RIV: EE - Microbiology, Virology Impact factor: 2.687, year: 2005

  10. Stability-increasing effects of anthocyanin glycosyl acylation.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. On separable extensions of group rings and quaternion rings

    Directory of Open Access Journals (Sweden)

    George Szeto

    1978-01-01

    Full Text Available The purposes of the present paper are (1 to give a necessary and sufficient condition for the uniqueness of the separable idempotent for a separable group ring extension RG(R may be a non-commutative ring, and (2 to give a full description of the set of separable idempotents for a quaternion ring extension RQ over a ring R, where Q are the usual quaternions i,j,k and multiplication and addition are defined as quaternion algebras over a field. We shall show that RG has a unique separable idempotent if and only if G is abelian, that there are more than one separable idempotents for a separable quaternion ring RQ, and that RQ is separable if and only if 2 is invertible in R.

  12. Acyl-Lipid Metabolism

    Science.gov (United States)

    Li-Beisson, Yonghua; Shorrosh, Basil; Beisson, Fred; Andersson, Mats X.; Arondel, Vincent; Bates, Philip D.; Baud, Sébastien; Bird, David; DeBono, Allan; Durrett, Timothy P.; Franke, Rochus B.; Graham, Ian A.; Katayama, Kenta; Kelly, Amélie A.; Larson, Tony; Markham, Jonathan E.; Miquel, Martine; Molina, Isabel; Nishida, Ikuo; Rowland, Owen; Samuels, Lacey; Schmid, Katherine M.; Wada, Hajime; Welti, Ruth; Xu, Changcheng; Zallot, Rémi; Ohlrogge, John

    2013-01-01

    Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables. PMID:23505340

  13. Acylation of Antioxidant of Bamboo Leaves with Fatty Acids by Lipase and the Acylated Derivatives' Efficiency in the Inhibition of Acrylamide Formation in Fried Potato Crisps.

    Directory of Open Access Journals (Sweden)

    Xiang Ma

    Full Text Available This study selectively acylated the primary hydroxyl groups on flavonoids in antioxidant of bamboo leaves (AOB using lauric acid with Candida antarctica lipase B in tert-amyl-alcohol. The separation and isolation of acylated derivatives were performed using silica gel column chromatography with a mixture of dichloromethane/diethyl ether/methanol as eluents. Both thin layer chromatography and high-performance liquid chromatography analyses confirmed the high efficiency of the isolation process with the purified orientin-6″-laurate, isoorientin-6″-laurate, vitexin-6″-laurate, and isovitexin-6″-laurate that were obtained. The addition of AOB and acylated AOB reduced acrylamide formation in fried potato crisps. Results showed that 0.05% AOB and 0.05% and 0.1% acylated AOB groups significantly (p < 0.05 reduced the content of acrylamide in potato crisps by 30.7%, 44.5%, and 46.9%, respectively.

  14. An approach to computing direction relations between separated object groups

    Science.gov (United States)

    Yan, H.; Wang, Z.; Li, J.

    2013-09-01

    Direction relations between object groups play an important role in qualitative spatial reasoning, spatial computation and spatial recognition. However, none of existing models can be used to compute direction relations between object groups. To fill this gap, an approach to computing direction relations between separated object groups is proposed in this paper, which is theoretically based on gestalt principles and the idea of multi-directions. The approach firstly triangulates the two object groups, and then it constructs the Voronoi diagram between the two groups using the triangular network. After this, the normal of each Voronoi edge is calculated, and the quantitative expression of the direction relations is constructed. Finally, the quantitative direction relations are transformed into qualitative ones. The psychological experiments show that the proposed approach can obtain direction relations both between two single objects and between two object groups, and the results are correct from the point of view of spatial cognition.

  15. Grouped actinide separation in advanced nuclear fuel cycles

    International Nuclear Information System (INIS)

    Glatz, J.P.; Malmbeck, R.; Ougier, M.; Soucek, P.; Murakamin, T.; Tsukada, T.; Koyama, T.

    2013-01-01

    Aiming at cleaner waste streams (containing only the short-lived fission products) a partitioning and transmutation (P-T) scheme can significantly reduce the quantities of long-lived radionuclides consigned to waste. Many issues and options are being discussed and studied at present in view of selecting the optimal route. The choice is between individual treatment of the relevant elements and a grouped treatment of all actinides together. In the European Collaborative Project ACSEPT (Actinide recycling by Separation and Transmutation), grouped separation options derived from an aqueous extraction or from a dry pyroprocessing route were extensively investigated. Successful demonstration tests for both systems have been carried out in the frame of this project. The aqueous process called GANEX (Grouped Actinide Extraction) is composed of 2 cycles, a first one to recover the major part of U followed by a co-extraction of Np, Pu, Am, and Cm altogether. The pyro-reprocessing primarily applicable to metallic fuels such as the U-Pu-Zr alloy originally developed by the Argonne National Laboratory (US) in the mid 1980s, has also been applied to the METAPHIX fuels containing up to 5% of minor actinides and 5% of lanthanides (e.g. U 60 Pu 20 -Zr 10 Am 2 Nd 3.5 Y 0.5 Ce 0.5 Gd 0.5 ). A grouped actinide separation has been successfully carried out by electrorefining on solid Al cathodes. At present the recovery of the actinides from the alloy formed with Al upon electrodeposition is under investigation, because an efficient P-T cycle requires multiple re-fabrication and re-irradiation. (authors)

  16. Beneficial effects of bacteria-plant communication based on quorum sensing molecules of the N-acyl homoserine lactone group.

    Science.gov (United States)

    Schikora, Adam; Schenk, Sebastian T; Hartmann, Anton

    2016-04-01

    Bacterial quorum sensing (QS) mechanisms play a crucial role in the proper performance and ecological fitness of bacterial populations. Many key physiological processes are regulated in a QS-dependent manner by auto-inducers, like the N-acyl homoserine lactones (AHLs) in numerous Gram-negative bacteria. In addition, also the interaction between bacteria and eukaryotic hosts can be regulated by AHLs. Those mechanisms gained much attention, because of the positive effects of different AHL molecules on plants. This positive impact ranges from growth promotion to induced resistance and is quite contrasting to the rather negative effects observed in the interactions between bacterial AHL molecules and animals. Only very recently, we began to understand the molecular mechanisms underpinning plant responses to AHL molecules. In this review, we gathered the latest information in this research field. The first part gives an overview of the bacterial aspects of quorum sensing. Later we focus on the impact of AHLs on plant growth and AHL-priming, as one of the most understood phenomena in respect to the inter-kingdom interactions based on AHL-quorum sensing molecules. Finally, we discuss the potential benefits of the understanding of bacteria-plant interaction for the future agricultural applications.

  17. Synthesis, Structure, and Anticancer Activity of Arene-Ruthenium(II) Complexes with Acylpyrazolones Bearing Aliphatic Groups in the Acyl Moiety.

    Science.gov (United States)

    Palmucci, Jessica; Marchetti, Fabio; Pettinari, Riccardo; Pettinari, Claudio; Scopelliti, Rosario; Riedel, Tina; Therrien, Bruno; Galindo, Agustin; Dyson, Paul J

    2016-11-21

    A series of neutral ruthenium(II) arene complexes [(arene)Ru(Q R )Cl] (arene = p-cymene (cym) or hexamethylbenzene (hmb)) containing 4-acyl-5-pyrazolonate Q R ligands with different electronic and steric substituents (R = 4-cyclohexyl, 4-stearoyl, or 4-adamantyl) and related ionic complexes [(arene)Ru(Q R )(PTA)][PF 6 ] (PTA = 1,3,5-triaza-7-phosphaadamantane) were synthesized and characterized by spectroscopy (IR, UV-vis, ESI-MS, and 1 H and 13 C NMR), elemental analysis, X-ray crystallography, and density functional theory studies. The cytotoxicity of the proligands and metal complexes was evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), as well as against nontumorous human embryonic kidney (HEK293) cells. In general the cationic PTA-containing complexes are more cytotoxic than their neutral precursors with a chloride ligand in place of the PTA. Moreover, the complexes do not show cross-resistance and are essentially equally cytotoxic to both the A2780 and A2780cisR cell lines, although they only show limited selectivity toward the cancer cell lines.

  18. Acyl-coenzyme A binding protein (ACBP)

    DEFF Research Database (Denmark)

    Kragelund, B B; Knudsen, J; Poulsen, F M

    1999-01-01

    Acyl-coenzyme A binding proteins are known from a large group of eukaryote species and to bind a long chain length acyl-CoA ester with very high affinity. Detailed biochemical mapping of ligand binding properties has been obtained as well as in-depth structural studies on the bovine apo-protein a...

  19. Acyl and silyl group effects in reactivity-based one-pot glycosylation: synthesis of embryonic stem cell surface carbohydrates Lc4 and IV(2)Fuc-Lc4.

    Science.gov (United States)

    Hsu, Yun; Lu, Xin-An; Zulueta, Medel Manuel L; Tsai, Chih-Ming; Lin, Kuo-I; Hung, Shang-Cheng; Wong, Chi-Huey

    2012-03-14

    Relative reactivity evaluations showed the graded arming of toluenyl thioglucosides by variously positioned silyl groups but not by their acyl counterparts. These findings were applied in reactivity-based one-pot assembly of linker-attached Lc(4) and IV(2)Fuc-Lc(4), which are components of human embryonic stem cell surface. The sugar-galectin-1 binding was also examined.

  20. Acyl hydrolases from trans-AT polyketide synthases target acetyl units on acyl carrier proteins.

    Science.gov (United States)

    Jenner, Matthew; Afonso, Jose P; Kohlhaas, Christoph; Karbaum, Petra; Frank, Sarah; Piel, Jörn; Oldham, Neil J

    2016-04-18

    Acyl hydrolase (AH) domains are a common feature of trans-AT PKSs. They have been hypothesised to perform a proofreading function by removing acyl chains from stalled sites. This study determines the substrate tolerance of the AH PedC for a range of acyl-ACPs. Clear preference towards short, linear acyl-ACPs is shown, with acetyl-ACP the best substrate. These results imply a more targeted housekeeping role for PedC: namely the removal of unwanted acetyl groups from ACP domains caused by erroneous transfer of acetyl-CoA, or possibly by decarboxylation of malonyl-ACP.

  1. Synthesis of coenzyme A thioesters using methyl acyl phosphates in an aqueous medium.

    Science.gov (United States)

    Pal, Mohan; Bearne, Stephen L

    2014-12-28

    Regioselective S-acylation of coenzyme A (CoA) is achieved under aqueous conditions using various aliphatic and aromatic carboxylic acids activated as their methyl acyl phosphate monoesters. Unlike many hydrophobic activating groups, the anionic methyl acyl phosphate mixed anhydride is more compatible with aqueous solvents, making it useful for conducting acylation reactions in an aqueous medium.

  2. Interaction of bovine serum albumin with N-acyl amino acid based anionic surfactants: Effect of head-group hydrophobicity.

    Science.gov (United States)

    Ghosh, Subhajit; Dey, Joykrishna

    2015-11-15

    The function of a protein depends upon its structure and surfactant molecules are known to alter protein structure. For this reason protein-surfactant interaction is important in biological, pharmaceutical, and cosmetic industries. In the present work, interactions of a series of anionic surfactants having the same hydrocarbon chain length, but different amino acid head group, such as l-alanine, l-valine, l-leucine, and l-phenylalanine with the transport protein, bovine serum albumin (BSA), were studied at low surfactant concentrations using fluorescence and circular dichroism (CD) spectroscopy, and isothermal titration calorimetry (ITC). The results of fluorescence measurements suggest that the surfactant molecules bind simultaneously to the drug binding site I and II of the protein subdomain IIA and IIIA, respectively. The fluorescence as well as CD spectra suggest that the conformation of BSA goes to a more structured state upon surfactant binding at low concentrations. The binding constants of the surfactants were determined by the use of fluorescence as well as ITC measurements and were compared with that of the corresponding glycine-derived surfactant. The binding constant values clearly indicate a significant head-group effect on the BSA-surfactant interaction and the interaction is mainly hydrophobic in nature. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. From Set Membership to Group Membership: A Separation of Concerns

    OpenAIRE

    Schiper, Andre; Toueg, Sam

    2003-01-01

    We revisit the well-known group membership problem and show how it can be considered a special case of a simple problem, the set membership problem. In the set membership problem, processes maintain a set whose elements are drawn from an arbitrary universe: They can request the addition or removal of elements to/from that set, and they agree on the current value of the set. Group membership corresponds to the special case where the elements of the set happen to be processes. We exploit this n...

  4. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    to the harsh and selective gastrointestinal system, and development has lacked far behind injection therapy. Peptide acylation is a powerful tool to alter the pharmacokinetics, biophysical properties and chemical stability of injectable peptide drugs, primarily used to prolong blood circulation....... This work aims to characterize acylated analogues of two therapeutic peptides by systematically increasing acyl chain length in order to elucidate its influence on membrane interaction and intestinal cell translocation in vitro. The studied peptides are the 33 amino acid Glucagon-like peptide-2 (GLP-2...... peptides can increase in vitro intestinal permeability, modestly for GLP-2 and drastically for sCT, and might benefit oral delivery. GLP-2 results provide a well-founded predictive power for future peptide analogues, whereas sCT results hold great promise for future analogues, albeit with a larger...

  5. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase

    Science.gov (United States)

    Thomas, Jacob

    2009-01-01

    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  6. Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity

    Directory of Open Access Journals (Sweden)

    Yandeau-Nelson Marna D

    2011-08-01

    Full Text Available Abstract Background Acyl-acyl carrier protein thioesterases (acyl-ACP TEs catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. Results To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their in vivo activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2 seven TEs were molecularly cloned from oil palm (Elaeis guineensis, coconut (Cocos nucifera and Cuphea viscosissima, organisms that produce medium-chain and short-chain fatty acids in their seeds. The in vivo substrate specificities of the acyl-ACP TEs were determined in E. coli. Based on their specificities, these enzymes were clustered into three classes: 1 Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2 Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3 Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family. Conclusion These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids.

  7. Density matrix renormalization group with efficient dynamical electron correlation through range separation

    DEFF Research Database (Denmark)

    Hedegård, Erik D.; Knecht, Stefan; Kielberg, Jesper Skau

    2015-01-01

    We present a new hybrid multiconfigurational method based on the concept of range-separation that combines the density matrix renormalization group approach with density functional theory. This new method is designed for the simultaneous description of dynamical and static electroncorrelation...... effects in multiconfigurational electronic structure problems....

  8. Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals.

    Science.gov (United States)

    Knap, Hasse C; Jørgensen, Solvejg

    2017-02-23

    We have used quantum mechanical chemical calculations (CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ) to investigate the hydrogen shift (H-shift) reactions in acyl peroxy and hydroperoxy acyl peroxy radicals. We have focused on the H-shift reactions from a hydroperoxy group (OOH) (1,X-OOH H-shift with X = 6, 7, 8, or 9) in the hydroperoxy acyl peroxy radicals, this H-shift is a reversible reaction and it scrambles between two peroxides, hydroperoxy acyl peroxy and peroxy peroxoic acid radicals. The forward reaction rate constants of the 1,X-OOH H-shift reactions are estimated to be above 10 3 s -1 with transition state theory corrected with Eckart quantum tunnelling correction. The ratio between the forward and reverse reaction rate constant of the 1,X-OOH H-shift reactions is around ∼10 5 . Therefore, the equilibrium is pushed toward the production of peroxy peroxoic acid radicals. These very fast 1,X-OOH H-shift reactions are much faster than the reactions with NO and HO 2 under most atmospheric conditions and must be included in the atmospheric models when hydroperoxy acyl peroxy radicals are oxidized. Finally, we have observed that H-shift reactions in a pentane acyl peroxy radical (C5-AOO) is fast (>1 s -1 ); this can have a significant influence on the possible formation of large acyl peroxy nitrate molecules.

  9. Dissecting stimulus-response binding effects: Grouping by color separately impacts integration and retrieval processes.

    Science.gov (United States)

    Laub, Ruth; Frings, Christian; Moeller, Birte

    2018-04-23

    In selection tasks, target and distractor features can be encoded together with the response into the same short-lived memory trace, or event file (see Hommel, 2004), leading to bindings between stimulus and response features. The repetition of a stored target or distractor feature can lead to the retrieval of the entire episode, including the response-so-called "binding effects." Binding effects due to distractor repetition are stronger for grouped than for nongrouped target and distractor stimulus configurations. Modulation of either of two mechanisms that lead to the observed binding effects might be responsible here: Grouping may influence either stimulus-response integration or stimulus-response retrieval. In the present study we investigated the influences of grouping on both mechanisms independently. In two experiments, target and distractor letters were grouped (or nongrouped) via color (dis)similarity separately during integration and retrieval. Grouping by color similarity affected integration and retrieval mechanisms independently and in different ways. Color dissimilarity enhanced distractor-based retrieval, whereas color similarity enhanced distractor integration. We concluded that stimulus grouping is relevant for binding effects, but that the mechanisms that contribute to binding effects should be carefully separated.

  10. Challenges in teaching international students: group separation, language barriers and culture differences

    OpenAIRE

    Medved, Dennis; Franco, Antonio; Gao, Xiang; Yang, Fangfang

    2013-01-01

    Every year, there are more than 2500 new international students coming to Lund University and starting their higher education path. A higher number of foreign students increased the international competitiveness of Lund University, but at the same time the international students had to face many problems for instance, culture shock and language barriers. In this report we focused on issues in teaching international students, specifically group separation, language barriers and cultural differ...

  11. Facial Asymmetry-Based Age Group Estimation: Role in Recognizing Age-Separated Face Images.

    Science.gov (United States)

    Sajid, Muhammad; Taj, Imtiaz Ahmad; Bajwa, Usama Ijaz; Ratyal, Naeem Iqbal

    2018-04-23

    Face recognition aims to establish the identity of a person based on facial characteristics. On the other hand, age group estimation is the automatic calculation of an individual's age range based on facial features. Recognizing age-separated face images is still a challenging research problem due to complex aging processes involving different types of facial tissues, skin, fat, muscles, and bones. Certain holistic and local facial features are used to recognize age-separated face images. However, most of the existing methods recognize face images without incorporating the knowledge learned from age group estimation. In this paper, we propose an age-assisted face recognition approach to handle aging variations. Inspired by the observation that facial asymmetry is an age-dependent intrinsic facial feature, we first use asymmetric facial dimensions to estimate the age group of a given face image. Deeply learned asymmetric facial features are then extracted for face recognition using a deep convolutional neural network (dCNN). Finally, we integrate the knowledge learned from the age group estimation into the face recognition algorithm using the same dCNN. This integration results in a significant improvement in the overall performance compared to using the face recognition algorithm alone. The experimental results on two large facial aging datasets, the MORPH and FERET sets, show that the proposed age group estimation based on the face recognition approach yields superior performance compared to some existing state-of-the-art methods. © 2018 American Academy of Forensic Sciences.

  12. Acylated cyanidin 3-sambubioside-5-glucosides in Matthiola incana.

    Science.gov (United States)

    Saito, N; Tatsuzawa, F; Nishiyama, A; Yokoi, M; Shigihara, A; Honda, T

    1995-03-01

    Four acylated cyanidin 3-sambubioside-5-glucosides were isolated from purple-violet flowers of Matthiola incana and their structures were determined by chemical and spectroscopic methods. Three acylated anthocyanins were cyanidin 3-O-(6-O-acyl-2-O-(2-O-sinapyl-beta-D-xylopyranosyl)-beta-D- glucopyranosides)-5-O-(6-O-malonyl-beta-D-glucopyranosides), in which the acyl group is p-coumaryl, caffeyl or ferulyl, respectively. The remaining pigment is free from malonic acid and was identified as cyanidin 3-O-(6-O-trans-ferulyl-2-O-(2- O-trans-sinapyl-beta-D-xylopyranosyl)-beta-D-glucopyranoside)-5-O- (beta-D-glucopyranoside). Analysis of the anthocyanin constituents in 16 purple-violet cultivars revealed that they contained the above triacylated anthocyanins in variable amounts as main pigments. An aromatic pair of pigments containing sinapic and ferulic acids are considered to produce an important intramolecular effect, making bluish colours in these flowers.

  13. Lithium isotope separation on an ion exchange resin having azacrown ether as an anchor group

    International Nuclear Information System (INIS)

    Kim, D.W.; Jeong, Y.K.; Lee, J.K.; Hong, Ch.P.; Kim, Ch.S.; Jeon, Y.Sh.

    1997-01-01

    As study on the separation of lithium isotopes was carried out with an ion exchange resin having 1,7,13-trioxa-4,10,16-triazacyclooctadecane (N 3 O 3 ) as an anchor group. The lighter isotope, 6 Li concentrated in the resin phase, while the heavier isotope, 7 Li is enriched in the fluid phase. Upon column chromatography [0.6 cm (I. D.) x 20 cm (height) using 1.0M ammonium chloride solution as an eluent, single separation factor, α, 1.068 ( 6 Li/ 7 Li) r esin/( 6 Li/ 7 Li) s olution was obtained by the GLUECKAUF method from the elution curve and isotope ratios. (author)

  14. Plant Acyl-CoA:Lysophosphatidylcholine Acyltransferases (LPCATs) Have Different Specificities in Their Forward and Reverse Reactions*

    Science.gov (United States)

    Lager, Ida; Yilmaz, Jenny Lindberg; Zhou, Xue-Rong; Jasieniecka, Katarzyna; Kazachkov, Michael; Wang, Peng; Zou, Jitao; Weselake, Randall; Smith, Mark A.; Bayon, Shen; Dyer, John M.; Shockey, Jay M.; Heinz, Ernst; Green, Allan; Banas, Antoni; Stymne, Sten

    2013-01-01

    Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) enzymes have central roles in acyl editing of phosphatidylcholine (PC). Plant LPCAT genes were expressed in yeast and characterized biochemically in microsomal preparations of the cells. Specificities for different acyl-CoAs were similar for seven LPCATs from five different species, including species accumulating hydroxylated acyl groups in their seed oil, with a preference for C18-unsaturated acyl-CoA and low activity with palmitoyl-CoA and ricinoleoyl (12-hydroxyoctadec-9-enoyl)-CoA. We showed that Arabidopsis LPCAT1 and LPCAT2 enzymes catalyzed the acylation and de-acylation of both sn positions of PC, with a preference for the sn-2 position. When acyl specificities of the Arabidopsis LPCATs were measured in the reverse reaction, sn-2-bound oleoyl, linoleoyl, and linolenoyl groups from PC were transferred to acyl-CoA to a similar extent. However, a ricinoleoyl group at the sn-2-position of PC was removed 4–6-fold faster than an oleoyl group in the reverse reaction, despite poor utilization in the forward reaction. The data presented, taken together with earlier published reports on in vivo lipid metabolism, support the hypothesis that plant LPCAT enzymes play an important role in regulating the acyl-CoA composition in plant cells by transferring polyunsaturated and hydroxy fatty acids produced on PC directly to the acyl-CoA pool for further metabolism or catabolism. PMID:24189065

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

    Science.gov (United States)

    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.

  16. The distressed brain: a group blind source separation analysis on tinnitus.

    Directory of Open Access Journals (Sweden)

    Dirk De Ridder

    Full Text Available Tinnitus, the perception of a sound without an external sound source, can lead to variable amounts of distress.In a group of tinnitus patients with variable amounts of tinnitus related distress, as measured by the Tinnitus Questionnaire (TQ, an electroencephalography (EEG is performed, evaluating the patients' resting state electrical brain activity. This resting state electrical activity is compared with a control group and between patients with low (N = 30 and high distress (N = 25. The groups are homogeneous for tinnitus type, tinnitus duration or tinnitus laterality. A group blind source separation (BSS analysis is performed using a large normative sample (N = 84, generating seven normative components to which high and low tinnitus patients are compared. A correlation analysis of the obtained normative components' relative power and distress is performed. Furthermore, the functional connectivity as reflected by lagged phase synchronization is analyzed between the brain areas defined by the components. Finally, a group BSS analysis on the Tinnitus group as a whole is performed.Tinnitus can be characterized by at least four BSS components, two of which are posterior cingulate based, one based on the subgenual anterior cingulate and one based on the parahippocampus. Only the subgenual component correlates with distress. When performed on a normative sample, group BSS reveals that distress is characterized by two anterior cingulate based components. Spectral analysis of these components demonstrates that distress in tinnitus is related to alpha and beta changes in a network consisting of the subgenual anterior cingulate cortex extending to the pregenual and dorsal anterior cingulate cortex as well as the ventromedial prefrontal cortex/orbitofrontal cortex, insula, and parahippocampus. This network overlaps partially with brain areas implicated in distress in patients suffering from pain, functional somatic syndromes and posttraumatic stress

  17. Separate groups of dopamine neurons innervate caudate head and tail encoding flexible and stable value memories

    Directory of Open Access Journals (Sweden)

    Hyoung F Kim

    2014-10-01

    Full Text Available Dopamine neurons are thought to be critical for reward value-based learning by modifying synaptic transmissions in the striatum. Yet, different regions of the striatum seem to guide different kinds of learning. Do dopamine neurons contribute to the regional differences of the striatum in learning? As a first step to answer this question, we examined whether the head and tail of the caudate nucleus of the monkey (Macaca mulatta receive inputs from the same or different dopamine neurons. We chose these caudate regions because we previously showed that caudate head neurons learn values of visual objects quickly and flexibly, whereas caudate tail neurons learn object values slowly but retain them stably. Here we confirmed the functional difference by recording single neuronal activity while the monkey performed the flexible and stable value tasks, and then injected retrograde tracers in the functional domains of caudate head and tail. The projecting dopaminergic neurons were identified using tyrosine hydroxylase immunohistochemistry. We found that two groups of dopamine neurons in the substantia nigra pars compacta project largely separately to the caudate head and tail. These groups of dopamine neurons were mostly separated topographically: head-projecting neurons were located in the rostral-ventral-medial region, while tail-projecting neurons were located in the caudal-dorsal-lateral regions of the substantia nigra. Furthermore, they showed different morphological features: tail-projecting neurons were larger and less circular than head-projecting neurons. Our data raise the possibility that different groups of dopamine neurons selectively guide learning of flexible (short-term and stable (long-term memories of object values.

  18. Electrochemical properties of polyolefine nonwoven fabric modified with carboxylic acid group for battery separator

    International Nuclear Information System (INIS)

    Choi, Seong-Ho; Park, Keung-Shik; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Pill-Kwang

    2000-01-01

    Carboxylic acid group was introduced by radiation-induced grafting of acrylic acid (AAc) onto polyolefine nonwoven fabric (PNF), wherein the PNF comprises at least about 60% of a polyethylene having a melting temperature at ∼132degC and no more than about 40% of a second polypropylene having a lower melting temperature at ∼162degC, for a battery separator. The AAc-grafted PNF was characterized by XPS, SEM, DSC, TGA and porosimeter. The wetting speed, electrolyte retention, electrical resistance, and tensile strength were evaluated after grafting of AAc. It was found that the wetting speed, electrolyte retention, thickness, and ion-exchange capacity increased, whereas the electrical resistance decreased with increasing grafting yield. The tensile strength decreased with increasing grafting yield, whereas the elongation decreased with increasing grafting yield. (author)

  19. Electrochemical properties of polyolefin nonwoven fabric modified with carboxylic acid group for battery separator

    International Nuclear Information System (INIS)

    Choi, Seong-Ho; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Kwang-Pill

    2001-01-01

    Carboxylic acid group was introduced by radiation-induced grafting of acrylic acid (AAc) onto polyolefine nonwoven fabric (PNF), wherein the PNF comprises at least about 60% of a polyethylene having a melting temperature at ∼132 deg. C and no more than about 40% of a second polypropylene having a lower melting temperature at ∼162 deg. C, for a battery separator. The AAc-grafted PNF was characterized by XPS, SEM, DSC, TGA and porosimeter. The wetting speed, electrolyte retention, electrical resistance, and tensile strength were evaluated after grafting of AAc. It was found that the wetting speed, electrolyte retention, thickness, and ion-exchange capacity increased, whereas the electrical resistance decreased with increasing grafting yield. The tensile strength decreased with increasing grafting yield, whereas the elongation decreased with increasing grafting yield. (author)

  20. Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Tina Kuo Fung [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25°C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB-, with all complexes containing only one NPB- per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH)4- (aq.), i.e. the complexation constants increase with increasing number of -OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB-) at higher concentrations. The -OH group on the NPB- which is left uncomplexed after one solute molecule had bound to the other two -OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA+ can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB-. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

  1. Cis–Trans Configuration of Coumaric Acid Acylation Affects the Spectral and Colorimetric Properties of Anthocyanins

    Directory of Open Access Journals (Sweden)

    Gregory T. Sigurdson

    2018-03-01

    Full Text Available The color expression of anthocyanins can be affected by a variety of environmental factors and structural characteristics. Anthocyanin acylation (type and number of acids is known to be key, but the influence of acyl isomers (with unique stereochemistries remains to be explored. The objective of this study was to investigate the effects of cis–trans configuration of the acylating group on the spectral and colorimetric properties of anthocyanins. Petunidin-3-rutinoside-5-glucoside (Pt-3-rut-5-glu and Delphinidin-3-rutinoside-5-glucoside (Dp-3-rut-5-glu and their cis and trans coumaroylated derivatives were isolated from black goji and eggplant, diluted in pH 1–9 buffers, and analyzed spectrophotometrically (380–700 nm and colorimetrically (CIELAB during 72 h of storage (25 °C, dark. The stereochemistry of the acylating group strongly impacted the spectra, color, and stability of the Dp and Pt anthocyanins. Cis acylated pigments exhibited the greatest λmax in all pH, as much as 66 nm greater than their trans counterparts, showing bluer hues. Cis acylation seemed to reduce hydration across pH, increasing color intensity, while trans acylation generally improved color retention over time. Dp-3-cis-p-cou-rut-5-glu exhibited blue hues even in pH 5 (C*ab = 10, hab = 256° where anthocyanins are typically colorless. Cis or trans double bond configurations of the acylating group affected anthocyanin spectral and stability properties.

  2. Can we separate verbs from their argument structure? A group study in aphasia.

    Science.gov (United States)

    Caley, Sarah; Whitworth, Anne; Claessen, Mary

    2017-01-01

    Given the integral role that verbs play in sentence production, understanding verb deficits is critical to clinical practice. Difficulties in sentence production are often directly related to an inability to retrieve argument structure information which, according to most theoretical accounts, is specified at a lexical level as part of the semantic representation of the verb. The presence of an argument complexity effect when retrieving verbs in isolation, i.e. increased difficulty with increasing number of arguments required by the verb, is considered evidence of the integral link between verbs and the ensuing structure. Recent reports, however, of relatively intact verb retrieval and impaired argument structure suggest that difficulties with verbs and argument structure may not always co-occur. One explanation for this is that lexical-syntactic information may be stored separately to lexical-semantic information at the lemma level and then differentially impaired. To determine whether the presence of difficulties creating argument structure in a group of people with aphasia with verb-retrieval deficits consistently aligned with the underlying nature of their impairment, where semantic involvement resulted in argument structure difficulties and post-semantic impairment resulted in intact argument structure. This would provide evidence either to support or to challenge the view that argument structure is lexically specified. The presence of an argument complexity effect within the participants' single verb naming was also investigated to examine the relationship between verb argument information and any subsequent difficulties creating argument structure for sentence production. Verb retrieval and argument structure production were investigated in 12 people with aphasia with verb-retrieval deficits on single-word and sentence-production measures. Eight of the 12 participants presented with a semantic verb deficit (five semantic and three mixed semantic and

  3. Synthesis of an O-acyl isopeptide by using native chemical ligation in an aqueous solvent system.

    Science.gov (United States)

    Kawashima, Hiroyuki; Kuruma, Tomomi; Yamashita, Masayuki; Sohma, Youhei; Akaji, Kenichi

    2014-05-01

    O-Acyl isopeptides, in which the N-acyl linkage on the hydroxyamino acid residue (e.g. Ser and Thr) is replaced by an O-acyl linkage, generally suppress unfavorable aggregation properties derived from the corresponding parent peptides. Here, we report the synthesis of an O-acyl isopeptide of 34-mer pyroGlu-ADan (2), a component of amyloid deposits in hereditary familial Danish dementia, by using native chemical ligation. Native chemical ligation of pyroGlu(1) -ADan(1-21)-SCH2 CH2 SO3 (-) Na(+) (3) and Cys(22) -O-acyl isopeptide (4), in which the amino group of the Ser(29) residue at the isopeptide moiety was protected by an allyloxycarbonyl group, proceeded well in an aqueous solvent to yield a ligated O-acyl isopeptide (5). Subsequent disulfide bond formation and deprotection of the allyloxycarbonyl group followed by HPLC purification gave 2 with a reasonable overall yield. 2 was converted to the parent peptide 1 via an O-to-N acyl migration reaction. The sequential method, namely (i) native chemical ligation of the O-acyl isopeptide, (ii) HPLC purification as the O-acyl isopeptide form, and (iii) O-to-N acyl migration into the desired polypeptide, would be helpful to solve problems with HPLC purification of hydrophobic polypeptides in the process of chemical protein synthesis. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  4. RNA SHAPE chemistry with aromatic acylating reagents.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Short-term separation from groups by male Japanese macaques: costs and benefits in feeding behavior and social interaction.

    Science.gov (United States)

    Otani, Yosuke; Sawada, Akiko; Hanya, Goro

    2014-04-01

    To expand our understanding of fission-fusion behavior and determine its variability among primates, studies of both individual-based and group-based fission-fusion are necessary. We conducted a parallel tracking study of male and female Japanese macaques (Macaca fuscata yakui) during the non-mating season to clarify the general features of separate ranging by males of this species, an example of fission-fusion behavior, and to reveal its associated costs and benefits. Males frequently engaged in short-term separate ranging, leaving the company of females and ranging on their own for periods averaging 68 min in duration. However, the males did not venture outside the group's home range. When ranging separately from the group, males spent more time feeding, particularly on fruit, stayed longer in each feeding tree, and fed at a lower rate than when ranging with the group. These behavioral changes suggest that males can avoid within-group feeding competition by ranging alone. However, this behavior was also associated with higher traveling costs, and these separated males were more vulnerable to intergroup competition and had fewer opportunities for social interaction. The frequency of separate ranging was lower when highly clumped food plant species were the main food source. Lower-ranked males, who received more aggression when ranging with the group, exhibited a higher frequency of separate ranging. This behavioral flexibility with respect to group cohesion may allow males to reduce the costs of group living without completely losing the benefits. Specifically, by ranging alone, males may acquire sufficient feeding time without being disturbed by other group members. Conversely, when ranging with the group, males can access grooming partners and advantages in intergroup competition. © 2013 Wiley Periodicals, Inc.

  6. Preservation of polyunsaturated fatty acyl glycerides via intramolecular antioxidant coupling

    Science.gov (United States)

    Ferulic acid and its esters are known to be effective antioxidants. Feruloyl di-gamma-linolenoylglycerol was assessed for its ability to serve as an antioxidant for preventing the oxidation of its gamma-linolenoyl polyunsaturated fatty acyl groups in model membrane phospholipid vesicles. The molec...

  7. Antileishmanial Activity of Aldonamides and N-Acyl-Diamine Derivatives

    Directory of Open Access Journals (Sweden)

    Elaine S. Coimbra

    2008-01-01

    Full Text Available A number of lipophilic N-acyl-diamines and aldonamides have been synthesized and tested for their in vitro antiproliferative activity against Leishmania amazonensis and L. chagasi. Ribonamides, having one amino group, displayed good to moderate inhibition of parasite growth. The best result was obtained for compounds 10 and 15 with IC50 against L. chagasi below 5 μM.

  8. Fatty acyl-CoA reductases of birds

    Directory of Open Access Journals (Sweden)

    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.

  9. Acyl-CoA metabolism and partitioning

    DEFF Research Database (Denmark)

    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......Long-chain fatty acyl-coenzyme As (CoAs) are critical regulatory molecules and metabolic intermediates. The initial step in their synthesis is the activation of fatty acids by one of 13 long-chain acyl-CoA synthetase isoforms. These isoforms are regulated independently and have different tissue...... 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...

  10. Sharing Classes between Separate Schools: A Mechanism for Improving Inter-Group Relations in Northern Ireland?

    Science.gov (United States)

    Hughes, Joanne; Lolliot, Simon; Hewstone, Miles; Schmid, Katharina; Carlisle, Karen

    2012-01-01

    One manifestation of division and the history of conflict in Northern Ireland is the parallel education system that exists for Protestants and Catholics. Although recent decades have seen some advances in the promotion of integrated education, around 95% of children continue to attend schools separated on ethno-religious lines. In 2007 a programme…

  11. Polyacrylonitrile based composite materials with extracting agents containing chemically bonded CMPO groups for separation of actinoids

    Czech Academy of Sciences Publication Activity Database

    Kameník, Jan; Šebesta, F.; John, J.; Böhmer, V.; Rudzevich, V.; Grüner, Bohumír

    2015-01-01

    Roč. 304, č. 1 (2015), s. 313-319 ISSN 0236-5731 Institutional support: RVO:61388980 ; RVO:61389005 Keywords : actinoids * CMPO * Calix[4]arene * cobalt bis(dicarbollide) * polyacrylonitrile * composite material Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.983, year: 2015

  12. Double Friedel-Crafts acylation reactions on the same ring of a metallocene: synthesis of a 2,5-diacetylphospharuthenocene.

    Science.gov (United States)

    Carmichael, Duncan; Le Floch, Pascal; Le Goff, Xavier F; Piechaczyk, Olivier; Seeboth, Nicolas

    2010-12-27

    The synthetic outcome of the Friedel-Crafts acylation of 1',2',3,3',4,4',5'-heptamethylphospharuthenocene reflects the nature of the acylating agent, with alkanoyl anhydride/trifluoromethanesulfonic acid (TfOH) reagents giving monosubstitution at the phospholyl ring, whereas alkanoyl chloride/AlCl(3) gives 2,5-disubstitution. DFT calculations indicate that this unusual double acylation can be facilitated by the intervention of the phosphorus atom at an early stage in the reaction trajectory, with the acyl group being delivered from the phosphorus atom into the ring 2- or 2,5-positions.

  13. Regulation of very-long acyl chain ceramide synthesis by acyl-CoA-binding protein

    DEFF Research Database (Denmark)

    Ferreira, Natalia Santos; Engelsby, Hanne; Neess, Ditte

    2017-01-01

    Ceramide and more complex sphingolipids constitute a diverse group of lipids that serve important roles as structural entities of biological membranes and as regulators of cellular growth, differentiation, and development. Thus, ceramides are vital players in numerous diseases including metabolic......-long-chain acyl-CoA esters, which is required for its ability to stimulate CerS activity. We also show that high-speed liver cytosol from wild-type mice activates CerS3 activity, whereas cytosol from ACBP knock-out mice does not. Consistently, CerS2 and CerS3 activities are significantly reduced in the testes...

  14. Renormalization-group study of superfluidity and phase separation of helium mixtures immersed in a disordered porous medium

    International Nuclear Information System (INIS)

    Lopatnikova, A.; Berker, A.N.

    1997-01-01

    Superfluidity and phase separation in 3 He- 4 He mixtures immersed in aerogel are studied by renormalization-group theory. The quenched disorder imposed by aerogel, both at the atomic level and at the geometric level, is included. The calculation is conducted via the coupled renormalization-group mappings, near and away from aerogel, of the quenched probability distributions of random interactions. Random-bond effects on the onset of superfluidity and random-field effects on superfluid-superfluid phase separation are seen. The quenched randomness causes the λ line of second-order phase transitions of superfluidity onset to reach zero temperature, in agreement with general predictions and experiments. The effects of the atomic and geometric randomness of aerogel are investigated separately and jointly. copyright 1997 The American Physical Society

  15. Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals

    DEFF Research Database (Denmark)

    Knap, Hasse Christian; Jørgensen, Solvejg

    2017-01-01

    -shift with X = 6, 7, 8, or 9) in the hydroperoxy acyl peroxy radicals, this H-shift is a reversible reaction and it scrambles between two peroxides, hydroperoxy acyl peroxy and peroxy peroxoic acid radicals. The forward reaction rate constants of the 1,X-OOH H-shift reactions are estimated to be above 103 s–1...... with transition state theory corrected with Eckart quantum tunnelling correction. The ratio between the forward and reverse reaction rate constant of the 1,X-OOH H-shift reactions is around ∼105. Therefore, the equilibrium is pushed toward the production of peroxy peroxoic acid radicals. These very fast 1,X-OOH H......We have used quantum mechanical chemical calculations (CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ) to investigate the hydrogen shift (H-shift) reactions in acyl peroxy and hydroperoxy acyl peroxy radicals. We have focused on the H-shift reactions from a hydroperoxy group (OOH) (1,X-OOH H...

  16. Exploring Cooperative Effects in Oxidative NHC Catalysis: Regioselective Acylation of Carbohydrates.

    Science.gov (United States)

    Cramer, David L; Bera, Srikrishna; Studer, Armido

    2016-05-23

    The utility of oxidative NHC catalysis for both the regioselective and chemoselective functionalization of carbohydrates is explored. Chiral NHCs allow for the highly regioselective oxidative esterification of various carbohydrates using aldehydes as acylation precursors. The transformation was also shown to be amenable to both cis/trans diol isomers, free amino groups, and selective for specific sugar epimers in competition experiments. Efficiency and regioselectivity of the acylation can be improved upon using two different NHC catalysts that act cooperatively. The potential of the method is documented by the regioselective acylation of an amino-linked neodisaccharide. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Grafting of chitosan with fatty acyl derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Chiandotti, Roberto S.; Rodrigues, Paula C.; Akcelrud, Leni, E-mail: leni@leniak.ne [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept de Quimica

    2010-07-01

    The internal plasticization of chitosan with covalently linked long aliphatic branches, typically 12C, was accomplished through the condensation of the amino groups of chitosan with acidic derivatives of lauric acid, as lauroyl anhydride or lauroyl chloride, that are more reactive than the fatty acid itself. The chemical pathway led to selective N-acylation. The degree of substitution was quantitatively determined by FTIR and {sup 1}H NMR and varied between 3 and 35%. The FTIR quantitative analysis was based in a calibration method with good accuracy. The modified chitosan products were soluble in neutral water and/or DMF according to the degree of substitution. The modified chitosan films were more flexible than the pristine, non-modified ones. (author)

  18. Report of the Energy Research Advisory Board study group on advanced isotope separation

    International Nuclear Information System (INIS)

    1980-11-01

    The Panel reviewed Advanced Isotope Separation (AIS) technology and Advanced Gas Centrifuge (AGC) programs in the context of potential needs and costs for uranium enrichment. The benefit of a successful AIS or AGC program would be a substantial reduction in enrichment costs below those of current centrifuge plants or below the power cost alone for gaseous diffusion plants. This report attempts to provide firm guidance for the next 2 to 3 years, at which time a further evaluation should guide decisions in regard to enrichment supply and development choices. On the basis of our perception of the long-term economic benefits of a successful AIS development, we support the continued pursuit of this option. In the interim, major requirements for enrichment must be satisfied. We assume that DOE will develop a firm funding plan for gaseous diffusion operations and power contracting to assure that the necessary supply of power will be available to meet the separative work commitments of the US enrichment enterprise. We recommend that the AIS program office further identify the key technical uncertainties of the various programs, thereby establishing the basis for near-term R and D leading to a decision whether and when to proceed with full-scale development. We believe that a stronger atomic vapor laser isotope separation (AVLIS) program would result from a consolidation of the Lawrence Livermore National Laboratory (LLNL) and Jersey Nuclear Avco Isotopes (JNAI) teams, leading to a more competitive AVLIS process. Hence, we recommend that DOE attempt to negotiate with JNAI to form a single, integrated, government-funded AVLIS program with appropriate elements of LLNL, JNAI and UCC-ND. We further recommend that JNAI be designated as lead laboratory in this program. We recommend that the DOE: continue with the first 2.2 million SWU increment of the gas centrifuge program, and continue the Advanced Gas Centrifuge development program, with high priority

  19. Neutron activation analysis of ultrabasis rock by Ge(Li) γ-ray spectrometry and group separation

    International Nuclear Information System (INIS)

    Chen Baoguan; Yuan Ling; Fang Chanmeng

    1986-01-01

    The analytical procedure for determination of 21 elements in two ultrabasis rock samples with Ge(Li) gamma-ray spectrometry and group separation was described. 8 elements including Cr, Fe, Co, Sc, Mn, Na, Cl and Br have been directly determined by INAA. 13 elements including La, Ce, Nd, Sm, Gd, Eu, Tb, Ho, Tm, Yb, Lu, Zn and Cs have been determined by radiochemical separation. The samples of international standard AGV-1 (Andesite) have also been analyzed. The agreement of the results with the values proposed by F.J.Flanagan is satisfactory

  20. The effective comparison between emotion-focused cognitive behavioral group therapy and cognitive behavioral group therapy in children with separation anxiety disorder.

    Science.gov (United States)

    Afshari, Afrooz; Neshat-Doost, Hamid Taher; Maracy, Mohammad Reza; Ahmady, Mozhgan Kar; Amiri, Shole

    2014-03-01

    Emotion-focused cognitive behavioral therapy (ECBT) is a new form of CBT with emotion regulation components. This form of treatment is suggested to be employed to improve dysregulation of anxiety and other kind of emotions in anxious children. This study observed and compared the effectiveness of CBT and ECBT on anxiety symptoms; sadness and anger management; and cognitive emotion regulation strategies in children with separation anxiety disorder (SAD). This study is a randomized clinical trial. Subjects were 30 children from 9 to 13-years-old (15 girls and 15 boys) with diagnosis of SAD, being randomly assigned to CBT, ECBT, and control groups (five girls and five boys in each group). Subject children in CBT group participated in 10-h weekly sessions within Coping Cat manual; whereas, subject children in ECBT group contributed in 12-h weekly sessions within ECBT. The control group received no treatment. The Screen for Child Anxiety Related Emotional Disorders (SCARED; child and parent forms), Children's Emotion Management Scale (CEMS; anger and sadness forms), and Cognitive Emotion Regulation Questionnaire (CERQ) tests administered to all subjects in pretest, posttest, and the follow-up measurement (3 months later). Analysis of covariance (ANCOVA) repeated measure and Kruskal-Wallis were applied to analyze data by Statistical Package for Social Sciences (SPSS) software package (v. 20). CBT and ECBT; demonstrated no significant difference in reducing separation anxiety and total anxiety symptoms from parent and children's reports. ECBT effectively increased anger coping and decreased negative cognitive strategies and dysregulation of anger in children, both in posttest and follow-up. Also, ECBT reduced sadness dysregulation and increased sadness coping, though these significant advantages were lost in 3 months later follow-up. CBT reduced negative cognitive strategies in follow-up and increased sadness coping in posttest. None of treatments affected on anger and

  1. Larval growth and drift pattern and the separation of herring spawning groups in the North Sea

    DEFF Research Database (Denmark)

    Munk, Peter; Christensen, Villy

    1990-01-01

    Yorkshire is evident from distributions of newly hatched herring larvae. The dramatic changes in relative importance of spawning grounds are traced in the data on both late larvae (6 months old) and juveniles (18 months old). The onset of extended spawning off Buchan and off Yorkshire was followed...... by increase in distinct groups of late larvae of large mean length, and by enlargement of a group of medium-sized juveniles. It is hypothesized that the identified groups are interconnected. Thus, larvae spawned off Buchan and off Yorkshire are found to have growth rates superior to those attained by larvae...

  2. Transoceanic dispersal and subsequent diversification on separate continents shaped diversity of the Xanthoparmelia pulla group (Ascomycota.

    Directory of Open Access Journals (Sweden)

    Guillermo Amo de Paz

    Full Text Available In traditional morphology-based concepts many species of lichenized fungi have world-wide distributions. Molecular data have revolutionized the species delimitation in lichens and have demonstrated that we underestimated the diversity of these organisms. The aim of this study is to explore the phylogeography and the evolutionary patterns of the Xanthoparmelia pulla group, a widespread group of one of largest genera of macrolichens. We used a dated phylogeny based on nuITS and nuLSU rDNA sequences and performed an ancestral range reconstruction to understand the processes and explain their current distribution, dating the divergence of the major lineages in the group. An inferred age of radiation of parmelioid lichens and the age of a Parmelia fossil were used as the calibration points for the phylogeny. The results show that many species of the X. pulla group as currently delimited are polyphyletic and five major lineages correlate with their geographical distribution and the biosynthetic pathways of secondary metabolites. South Africa is the area where the X. pulla group radiated during the Miocene times, and currently is the region with the highest genetic, morphological and chemical diversity. From this center of radiation the different lineages migrated by long-distance dispersal to others areas, where secondary radiations developed. The ancestral range reconstruction also detected that a secondary lineage migrated from Australia to South America via long-distance dispersal and subsequent continental radiation.

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

    Directory of Open Access Journals (Sweden)

    Bina S. Siddiqui

    2008-08-01

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

  4. Polyacrylonitrile based composite materials with extracting agents containing chemically bonded CMPO groups for separation of actinoids

    International Nuclear Information System (INIS)

    Jan Kamenik; Ferdinand Sebesta; Jan John

    2015-01-01

    Composite materials made from polyacrylonitrile binding polymer and solid extracting agents with functional groups of diphenyl-carbamoylmethylphosphine oxide bonded to a platform of calix[4]arenes and cobalt bis(dicarbollide) cluster anion were tested for application in column chromatography. They exhibited high affinity for americium, plutonium, uranium, and europium ions in nitric acid solutions. However, europium distribution isotherm in 3 M HNO 3 indicated low capacity and unsatisfactory employment of the functional groups. Similar material with octyl(phenyl)-N,N'-diisobutylcarbamoylmethylphosphine oxide extracting agent had both high affinity and uptake capacity. (author)

  5. Group separation of rare earth elements by liquid-liquid extraction for the neutron activation analysis of silicate rocks

    International Nuclear Information System (INIS)

    Wyttenbach, A.; Bajo, S.; Tobler, L.

    1983-01-01

    Rare earth elements are isolated as a group from neutron activated rock samples by a new radiochemical procedure based on extraction with thenoyltrifluoracetone/phenanthroline in CHCl 3 . The procedure consists of three extraction steps, obviates the use of inactive carriers and gives practically quantitative chemical yields, thereby avoiding fractionation of the individual rare earths. Details of the dissolution, chemical separations. and counting procedure are given together with an analysis of BCR-1. (author)

  6. Effect of Bulky and Hydroxyl Groups on Gas Separation Performance of Polyimide Membranes.

    Science.gov (United States)

    Lee, Bo Mi; Kim, Deuk Ju; Nam, Sang Yong

    2015-03-01

    A series of polyimides were synthesized by a polycondensation reaction using various aromatic dianhydrides and diamines containing bulky cardo and hydroxyl groups. The imidization and chemical structure of the polyimides were confirmed by NMR and FT-IR. The thermal and gas properties of the polyimides were measured by time-lag, XRD, TGA, and DSC studies. The polyimides showed excellent solubility in common organic solvents and high thermal stability. The CO2 selectivity of HPI membrane was higher than traditional polyimides. In particular, the incorporation of hydroxyl groups improved the CO2 permeability of the polyimide due to increased carbon dioxide solubility. The HPI was thermally converted to polybenzoxazole (PBO) at 450 °C.

  7. Separation of flavonoids on different phenyl-bonded stationary phases-the influence of polar groups in stationary phase structure.

    Science.gov (United States)

    Janas, Petr; Bocian, Szymon; Jandera, Pavel; Kowalkowski, Tomasz; Buszewski, Bogusław

    2016-01-15

    Four phenyl-bonded stationary phases, differing in polar embedded group between spacer and phenyl ring, were used for the separation of flavonoids in reversed-phase conditions. In addition, the work was focused on the comparison of these stationary phases in terms of retention and nature of interactions between flavonoid solutes and both, mobile and stationary phases. The differences and similarities between the columns and between individual flavonoids were evaluated by a statistical analysis. The retention over the wider range of mobile phase composition was described using well known model suggested for partition chromatographic systems. Due to differences in polarity of flavonoids, gradient elution had to be applied to achieve appropriate conditions for the successful separation. A chromatographic optimization software was employed for establish the appropriate profiles of gradient separations using UV detection at 275 nm. The most appropriate conditions for the separation of flavonoids were apparent on the phenyl and phenoxy columns. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The effective comparison between emotion-focused cognitive behavioral group therapy and cognitive behavioral group therapy in children with separation anxiety disorder

    Directory of Open Access Journals (Sweden)

    Afrooz Afshari

    2014-01-01

    Full Text Available Background: Emotion-focused cognitive behavioral therapy (ECBT is a new form of CBT with emotion regulation components. This form of treatment is suggested to be employed to improve dysregulation of anxiety and other kind of emotions in anxious children. This study observed and compared the effectiveness of CBT and ECBT on anxiety symptoms; sadness and anger management; and cognitive emotion regulation strategies in children with separation anxiety disorder (SAD. Materials and Methods: This study is a randomized clinical trial. Subjects were 30 children from 9 to 13-years-old (15 girls and 15 boys with diagnosis of SAD, being randomly assigned to CBT, ECBT, and control groups (five girls and five boys in each group. Subject children in CBT group participated in 10-h weekly sessions within Coping Cat manual; whereas, subject children in ECBT group contributed in 12-h weekly sessions within ECBT. The control group received no treatment. The Screen for Child Anxiety Related Emotional Disorders (SCARED; child and parent forms, Children′s Emotion Management Scale (CEMS; anger and sadness forms, and Cognitive Emotion Regulation Questionnaire (CERQ tests administered to all subjects in pretest, posttest, and the follow-up measurement (3 months later. Analysis of covariance (ANCOVA repeated measure and Kruskal-Wallis were applied to analyze data by Statistical Package for Social Sciences (SPSS software package (v. 20. Results: CBT and ECBT; demonstrated no significant difference in reducing separation anxiety and total anxiety symptoms from parent and children′s reports. ECBT effectively increased anger coping and decreased negative cognitive strategies and dysregulation of anger in children, both in posttest and follow-up. Also, ECBT reduced sadness dysregulation and increased sadness coping, though these significant advantages were lost in 3 months later follow-up. CBT reduced negative cognitive strategies in follow-up and increased sadness coping

  9. Preliminary study for the separation of rare earth group elements in medium and heavy fractions by solvent extraction

    International Nuclear Information System (INIS)

    Soares, P.S.M.

    1994-01-01

    The objective of the study is the definition of a solvent extraction system suitable to achieve the separation of Rare Earth group elements, contained in hydrochloric acid media, into two fractions, medium and heavy rare earth groups. The experimental programme is proposed and developed in two parts, batch and continuous tests, with phosphonic acid, in an aliphatic diluent. In these tests, extraction and stripping behaviour of Y, Dy, Sm and Gd are examined, as they are the most concentrated elements in the solution feed. Y is the most extracted element and Dy is extracted along with Y due to the low separation factor Y/Dy = 3.64, identified for the system studied. Sm and Gd practically are not extracted into the organic phase and under the same conditions are easily scrubbed from it. Results obtained in batch were confirmed in continuous tests performed in laboratory scale mixer settlers assembly. It is proposed and successfully tested a solvent extraction circuit suitable to achieve the separation of the rare earth mixture studied in two concentrates one rich in Sm, Gd and the other rich in Dy, Y respectively. The point of fractioning of this mixture for the experimental conditions studied is located between the elements Gd and Dy. (author). 135 refs., 36 figs., 14 tabs

  10. THE ESSENTIAL E. COLI APOLIPOPROTEIN N-ACYLTRANSFERASE (LNT) EXISTS AS AN EXTRACYTOPLASMIC THIOESTER ACYL-ENZYME INTERMEDIATE‡

    OpenAIRE

    Buddelmeijer, Nienke; Young, Ry

    2010-01-01

    Escherichia coli apolipoprotein N-acyltransferase (Lnt) transfers an acyl group from sn-1-glycerolphospholipid to the free α-amino group of the N-terminal cysteine of apolipoproteins, resulting in mature triacylated lipoprotein. Here we report that the Lnt reaction proceeds through an acyl enzyme intermediate in which a palmitoyl group forms a thioester bond with the thiol of active site residue C387 that was cleaved by neutral hydroxylamine. Lnt(C387S) also formed a fatty acyl intermediate t...

  11. The essential Escherichia coli apolipoprotein N-acyltransferase (Lnt) exists as an extracytoplasmic thioester acyl-enzyme intermediate.

    Science.gov (United States)

    Buddelmeijer, Nienke; Young, Ry

    2010-01-19

    Escherichia coli apolipoprotein N-acyltransferase (Lnt) transfers an acyl group from sn-1-glycerophospholipid to the free alpha-amino group of the N-terminal cysteine of apolipoproteins, resulting in mature triacylated lipoprotein. Here we report that the Lnt reaction proceeds through an acyl-enzyme intermediate in which a palmitoyl group forms a thioester bond with the thiol of the active site residue C387 that was cleaved by neutral hydroxylamine. Lnt(C387S) also formed a fatty acyl intermediate that was resistant to neutral hydroxylamine treatment, consistent with formation of an oxygen-ester linkage. Lnt(C387A) did not form an acyl-enzyme intermediate and, like Lnt(C387S), did not have any detectable Lnt activity, indicating that acylation cannot occur at other positions in the catalytic domain. The existence of this thioacyl-enzyme intermediate allowed us to determine whether essential residues in the catalytic domain of Lnt affect the first step of the reaction, the formation of the acyl-enzyme intermediate, or the second step in which the acyl chain is transferred to the apolipoprotein substrate. In the catalytic triad, E267 is required for the formation of the acyl-enzyme intermediate, indicating its role in enhancing the nucleophilicity of C387. E343 is also involved in the first step but is not in close proximity to the active site. W237, Y388, and E389 play a role in the second step of the reaction since acyl-Lnt is formed but N-acylation does not occur. The data presented allow discrimination between the functions of essential Lnt residues in catalytic activity and substrate recognition.

  12. THE ESSENTIAL E. COLI APOLIPOPROTEIN N-ACYLTRANSFERASE (LNT) EXISTS AS AN EXTRACYTOPLASMIC THIOESTER ACYL-ENZYME INTERMEDIATE‡

    Science.gov (United States)

    Buddelmeijer, Nienke; Young, Ry

    2011-01-01

    Escherichia coli apolipoprotein N-acyltransferase (Lnt) transfers an acyl group from sn-1-glycerolphospholipid to the free α-amino group of the N-terminal cysteine of apolipoproteins, resulting in mature triacylated lipoprotein. Here we report that the Lnt reaction proceeds through an acyl enzyme intermediate in which a palmitoyl group forms a thioester bond with the thiol of active site residue C387 that was cleaved by neutral hydroxylamine. Lnt(C387S) also formed a fatty acyl intermediate that was resistant to neutral hydroxylamine treatment, consistent with formation of an oxygen-ester linkage. Lnt(C387A) did not form an acyl enzyme intermediate and, like Lnt(C387S), did not have any detectable Lnt activity, indicating that acylation can not occur at other positions in the catalytic domain. The existence of this thioacyl-enzyme intermediate allowed us to determine whether essential residues in the catalytic domain of Lnt affect the first step of the reaction, the formation of the acyl enzyme intermediate, or the second step in which the acyl chain is transferred to apolipoprotein substrate. In the catalytic triad, E267 is required for the formation of the acyl-enzyme intermediate, indicating its role in enhancing the nucleophilicity of C387. E343 is also involved in the first step but is not in close proximity to the active site. W237, Y388 and E389 play a role in the second step of the reaction since acyl-Lnt is formed but N-acylation does not occur. The data presented allow discrimination between the functions of essential Lnt residues in catalytic activity and substrate recognition. PMID:20000742

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

    DEFF Research Database (Denmark)

    Cohen Simonsen, A; Bernchou Jensen, U; Færgeman, Nils J.

    2003-01-01

    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...

  14. Fatty acyl-CoA reductase

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Plasma levels of acylated and total ghrelin in pediatric patients with chronic kidney disease.

    Science.gov (United States)

    Naufel, Maria Fernanda Soares; Bordon, Milena; de Aquino, Talita Marques; Ribeiro, Eliane Beraldi; de Abreu Carvalhaes, João Tomás

    2010-12-01

    This cross-sectional study set out to compare total and acyl ghrelin levels in children with mild chronic kidney disease (CKD) undergoing conservative treatment (n = 19) with children with end-stage renal disease (ESRD) undergoing hemodialysis (n = 24), and with healthy controls (n = 20). The relationship between ghrelin levels and parameters of renal function, nutritional status, and selective hormones were investigated. ESRD patients had higher total ghrelin levels than those with mild CKD or control individuals. However, acyl ghrelin did not differ between groups, indicating that the excess circulating ghrelin was desacylated. Since desacyl ghrelin has been shown to inhibit appetite, increased levels might contribute to protein-energy wasting in pediatric renal patients. When all 43 renal patients were combined, multiple regression analysis found age and glomerular filtration rate (GFR) to be significant negative predictors of total ghrelin. Acyl ghrelin was influenced negatively by age and positively by energy intake. Acyl to total ghrelin ratio related positively to GFR and energy intake. The results indicate that total but not acyl ghrelin is influenced by low GFR in children with CKD and suggests that ghrelin activation may be impaired in these patients. Since energy intake is a positive predictor of acyl ghrelin, the physiological control of ghrelin secretion appears to be altered in pediatric renal patients.

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

    Directory of Open Access Journals (Sweden)

    Siham eRaboune

    2014-08-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Binding of acyl CoA by fatty acid binding protein and the effect on fatty acid activation

    International Nuclear Information System (INIS)

    Burrier, R.E.; Manson, C.R.; Brecher, P.

    1987-01-01

    The ability of purified rat liver and heart fatty acid binding proteins (FABPs) to bind oleoyl CoA and modulate acyl CoA synthesis by microsomal membranes was investigated. Using binding assays employing either Lipidex 1000 or multilamellar liposomes to sequester unbound ligand, rat liver but not rat heart FABP was shown to bind radiolabeled acyl CoA. Binding studies suggest that liver FABP has a single binding site for acyl CoA which is separate from the two binding sites for fatty acids. Experiments were then performed to determine how binding may influence acyl CoA metabolism by liver microsomes or heart sarcoplasmic reticulum. Using liposomes as fatty acid donors, liver FABP stimulated acyl CoA production whereas heart FABP did not stimulate production over control values. 14 C-Fatty acid-FABP complexes were prepared, incubated with membranes and acyl CoA synthetase activity was determined. Up to 70% of the fatty acid could be converted to acyl CoA in the presence of liver FABP but in the presence of heart FABP, only 45% of the fatty acid was converted. The amount of product formed was not changed by additional membrane, enzyme cofactor, or incubation time. Liver but not heart FABP bound the acyl CoA formed and removed it from the membranes. These studies suggest that liver FABP can increase the amount of acyl CoA by binding this ligand thereby removing it from the membrane and possibly aiding transport within the cell

  19. Binding of acyl CoA by fatty acid binding protein and the effect on fatty acid activation

    Energy Technology Data Exchange (ETDEWEB)

    Burrier, R.E.; Manson, C.R.; Brecher, P.

    1987-05-01

    The ability of purified rat liver and heart fatty acid binding proteins (FABPs) to bind oleoyl CoA and modulate acyl CoA synthesis by microsomal membranes was investigated. Using binding assays employing either Lipidex 1000 or multilamellar liposomes to sequester unbound ligand, rat liver but not rat heart FABP was shown to bind radiolabeled acyl CoA. Binding studies suggest that liver FABP has a single binding site for acyl CoA which is separate from the two binding sites for fatty acids. Experiments were then performed to determine how binding may influence acyl CoA metabolism by liver microsomes or heart sarcoplasmic reticulum. Using liposomes as fatty acid donors, liver FABP stimulated acyl CoA production whereas heart FABP did not stimulate production over control values. /sup 14/C-Fatty acid-FABP complexes were prepared, incubated with membranes and acyl CoA synthetase activity was determined. Up to 70% of the fatty acid could be converted to acyl CoA in the presence of liver FABP but in the presence of heart FABP, only 45% of the fatty acid was converted. The amount of product formed was not changed by additional membrane, enzyme cofactor, or incubation time. Liver but not heart FABP bound the acyl CoA formed and removed it from the membranes. These studies suggest that liver FABP can increase the amount of acyl CoA by binding this ligand thereby removing it from the membrane and possibly aiding transport within the cell.

  20. Synthesis and biological evaluation of S-acyl-3-thiopropyl prodrugs of N-phosphonoacetyl-L-aspartate (PALA).

    Science.gov (United States)

    Gagnard, Valérie; Leydet, Alain; Le Mellay, Véronique; Aubenque, Marielle; Morère, Alain; Montero, Jean-Louis

    2003-10-01

    The synthesis of new prodrugs of PALA characterised by the presence of S-acyl-3-thiopropyl, as enzyme-labile groups on the phosphonate moiety of PALA, is reported. The cytotoxic activities of PALA prodrugs were determined against human cell line (SW1573 lung carcinoma cells). A number of prodrugs bearing S-pivaloyl as acyl groups displayed cytotoxic activity in the same order of magnitude of PALA.

  1. Can Stereoclusters Separated by Two Methylene Groups Be Related by DFT Studies? The Case of the Cytotoxic Meroditerpenes Halioxepines.

    Science.gov (United States)

    Tarazona, Guillermo; Benedit, Gonzalo; Fernández, Rogelio; Pérez, Marta; Rodríguez, Jaime; Jiménez, Carlos; Cuevas, Carmen

    2018-02-23

    QM/NMR-DFT (quantum mechanics combined with nuclear magnetic resonance parameters calculated by density functional theory approximations) studies allowed us to link two stereoclusters separated by two methylene groups present in the new meroditerpenes halioxepine B (2) and halioxepine C (3) and the known halioxepine (1), isolated from two Indonesian sponges of the genus Haliclona (Reniera). DP4 and DP4+ probabilities were used to discriminate the two diastereotopic arrangements of the two stereoclusters, whose unconnected relative configurations were determined by ROESY and J-based configurational analysis. To confirm the DFT studies, the full relative configuration of 1 was deduced using a mixture of benzene-d 6 and pyridine-d 5 as the NMR solvent. ROESY measurements connected the two stereoclusters and demonstrated that DFT calculations accurately predict the configuration when two methylenes separate the two stereoclusters. The different arrangements of the distant stereoclusters C-1/C-2/C-7 and C-10/C-15 for compounds 2 and 3 were deduced by DFT calculations and explained the opposite optical rotations observed for the two compounds. Halioxepines B (2) and C (3) display moderate cytotoxicity against different human cancer cell lines.

  2. Chlorogenic acids and the acyl-quinic acids: discovery, biosynthesis, bioavailability and bioactivity.

    Science.gov (United States)

    Clifford, Michael N; Jaganath, Indu B; Ludwig, Iziar A; Crozier, Alan

    2017-12-13

    Covering: 2000 up to late 2017This review is focussed upon the acyl-quinic acids, the most studied group within the ca. 400 chlorogenic acids so far reported. The acyl-quinic acids, the first of which was characterised in 1846, are a diverse group of plant-derived compounds produced principally through esterification of an hydroxycinnamic acid and 1l-(-)-quinic acid. Topics addressed in this review include the confusing nomenclature, quantification and characterisation by NMR and MS, biosynthesis and role in planta, and the occurrence of acyl-quinic acids in coffee, their transformation during roasting and delivery to the beverage. Coffee is the major human dietary source world-wide of acyl-quinic acids and consideration is given to their absorption and metabolism in the upper gastrointestinal tract, and the colon where the microbiota play a key role in the formation of catabolites. Evidence on the potential of the in vivo metabolites and catabolites of acyl-quinic acids to promote the consumer's health is evaluated.

  3. Toward Green Acylation of (Heteroarenes: Palladium-Catalyzed Carbonylation of Olefins to Ketones

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2017-11-01

    Full Text Available Green Friedel–Crafts acylation reactions belong to the most desired transformations in organic chemistry. The resulting ketones constitute important intermediates, building blocks, and functional molecules in organic synthesis as well as for the chemical industry. Over the past 60 years, advances in this topic have focused on how to make this reaction more economically and environmentally friendly by using green acylating conditions, such as stoichiometric acylations and catalytic homogeneous and heterogeneous acylations. However, currently well-established methodologies for their synthesis either produce significant amounts of waste or proceed under harsh conditions, limiting applications. Here, we present a new protocol for the straightforward and selective introduction of acyl groups into (hetero­arenes without directing groups by using available olefins with inexpensive CO. In the presence of commercial palladium catalysts, inter- and intramolecular carbonylative C–H functionalizations take place with good regio- and chemoselectivity. Compared to classical Friedel–Crafts chemistry, this novel methodology proceeds under mild reaction conditions. The general applicability of this methodology is demonstrated by the direct carbonylation of industrial feedstocks (ethylene and diisobutene as well as of natural products (eugenol and safrole. Furthermore, synthetic applications to drug molecules are showcased.

  4. In silico prediction of acyl glucuronide reactivity

    Science.gov (United States)

    Potter, Tim; Lewis, Richard; Luker, Tim; Bonnert, Roger; Bernstein, Michael A.; Birkinshaw, Timothy N.; Thom, Stephen; Wenlock, Mark; Paine, Stuart

    2011-11-01

    Drugs and drug candidates containing a carboxylic acid moiety, including many widely used non-steroidal anti-inflammatory drugs (NSAIDs) are often metabolized to form acyl glucuronides (AGs). NSAIDs such as Ibuprofen are amongst the most widely used drugs on the market, whereas similar carboxylic acid drugs such as Suprofen have been withdrawn due to adverse events. Although the link between these AG metabolites and toxicity is not proven, there is circumstantial literature evidence to suggest that more reactive acyl glucuronides may, in some cases, present a greater risk of exhibiting toxic effects. We wished therefore to rank the reactivity of potential new carboxylate-containing drug candidates, and performed kinetic studies on synthetic acyl glucuronides to benchmark our key compounds. Driven by the desire to quickly rank the reactivity of compounds without the need for lengthy synthesis of the acyl glucuronide, a correlation was established between the degradation half-life of the acyl glucuronide and the half life for the hydrolysis of the more readily available methyl ester derivative. This finding enabled a considerable broadening of chemical property space to be investigated. The need for kinetic measurements was subsequently eliminated altogether by correlating the methyl ester hydrolysis half-life with the predicted 13C NMR chemical shift of the carbonyl carbon together with readily available steric descriptors in a PLS model. This completely in silico prediction of acyl glucuronide reactivity is applicable within the earliest stages of drug design with low cost and acceptable accuracy to guide intelligent molecular design. This reactivity data will be useful alongside the more complex additional pharmacokinetic exposure and distribution data that is generated later in the drug discovery process for assessing the overall toxicological risk of acidic drugs.

  5. Acyl Chain Preference in Foam Cell Formation from Mouse Peritoneal Macrophages.

    Science.gov (United States)

    Fujiwara, Yuko; Hama, Kotaro; Tsukahara, Makoto; Izumi-Tsuzuki, Ryosuke; Nagai, Toru; Ohe-Yamada, Mihoko; Inoue, Keizo; Yokoyama, Kazuaki

    2018-01-01

    Macrophage foam cells play critical roles in the initiation and development of atherosclerosis by synthesizing and accumulating cholesteryl ester (CE) in lipid droplets. However, in analyzing lipid metabolism in foam cell formation, studies have focused on the sterol group, and little research has been done on the acyl chains. Therefore, we adapted a model system using liposomes containing particular acyl chains and examined the effect of various acyl chains on foam cell formation. Of the phosphatidylserine (PS) liposomes tested containing PS, phosphatidylcholine, and cholesterol, we found that unsaturated (C18:1), but not saturated (C16:0 and C18:0), PS liposomes induced lipid droplet formation, indicating that foam cell formation depends on the nature of the acyl chain of the PS liposomes. Experiments on the uptake and accumulation of cholesterol from liposomes by adding [ 14 C]cholesterol suggested that foam cell formation could be induced only when cholesterol was converted to CE in the case of C18:1 PS liposomes. Both microscopic observations and metabolic analysis suggest that cholesterol incorporated into either C16:0 or C18:0 PS liposomes may stay intact after being taken in by endosomes. The [ 14 C]C18:1 fatty acyl chain in the C18:1 PS liposome was used to synthesize CE and triacylglycerol (TG). Interestingly, the [ 14 C]C16:0 in the C18:1 PS liposome was metabolized to sphingomyelin rather than being incorporated into either CE or TG, which could be because of enzymatic acyl chain selectivity. In conclusion, our results indicate that the acyl chain preference of macrophages could have some impact on their progression to foam cells.

  6. Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate. [1,2-propanediol

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Tina Kuo Fung.

    1992-05-01

    The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25{degree}C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB{sup {minus}}, with all complexes containing only one NPB{sup {minus}} per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH){sub 4}{sup {minus}} (aq.), i.e. the complexation constants increase with increasing number of {minus}OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB{sup {minus}}) at higher concentrations. The {minus}OH group on the NPB{sup {minus}} which is left uncomplexed after one solute molecule had bound to the other two {minus}OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA{sup +} can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB{sup {minus}}. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

  7. 11-nor-9-carboxy-Δ9-tetrahydrocannabinol glucuronide exhibits acyl-migration isomers.

    Science.gov (United States)

    Hanisch, Stephanie; Paulke, Alexander; Toennes, Stefan W

    2017-11-30

    11-nor-Δ 9 -Tetrahydrocannabinol-9-carboxylic acid glucuronide (THCCOOH-glucuronide) is an 1-β-O-acyl glucuronide which degrades not only to 11-nor-9-carboxy-Δ 9 -THC (THCCOOH) but, additionally, to an isomer with a currently unknown structure. The present study was carried out to examine whether acyl glucuronide isomers are formed by acyl migration and if they are involved in formation of this isomer. THCCOOH-glucuronide was incubated in phosphate buffer (pH 7.4, 37°C, 7days) and a variety of glucuronide cleavage procedures were performed. Samples of the incubation mixture and of different biological specimens from cannabis users were analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). A total of six chromatographically separated isomeric acyl glucuronides were detected during incubation of THCCOOH-glucuronide reference substance. In biological specimens of cannabis users, two additional isomers were found. However, the main glucuronide present in human specimens was different from that of a commercially available reference substance. Both, the commercial and the authentic glucuronide were cleaved by β-glucuronidases, the other formed isomers by alkaline hydrolysis only. Mass spectrometric investigations (i.e. product ion, precursor ion and neutral loss scans) confirmed identity. The THCCOOH isomer was detected in all authentic samples, but not in those after buffer incubation. By analyzing THCCOOH-glucuronide in authentic samples, it has to be taken into account that the authentic glucuronide is different from that of the commercial reference standard. THCCOOH-glucuronide undergoes acyl migration and some isomers occur to minor extents in biological specimens. Acyl migration does not lead to the formation of the THCCOOH isomer. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    DEFF Research Database (Denmark)

    Knudsen, J; Jensen, M V; Hansen, J K

    1999-01-01

    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...

  9. Acylated flavonol glycosides from Larix needles

    NARCIS (Netherlands)

    Niemann, Gerard J.

    2006-01-01

    Kaempferol-3-p-coumarylglucoside (KCG) was isolated from ether fractions of acetone-extracted freeze-dried needles of all larch species investigated. In each case, KCG was found as one of the main flavonoids, whereas often a variety of closely related, acylated flavonoids was present in either

  10. Veronica: Acylated flavone glycosides as chemosystematic markers

    DEFF Research Database (Denmark)

    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...

  11. Lanthanum Tricyanide-Catalyzed Acyl Silane-Ketone Benzoin Additions and Kinetic Resolution of Resultant α-Silyloxyketones

    Science.gov (United States)

    Tarr, James C.

    2010-01-01

    We report the full account of our efforts on the lanthanum tricyanide-catalyzed acyl silane-ketone benzoin reaction. The reaction exhibits a wide scope in both acyl silane (aryl, alkyl) and ketone (aryl-alkyl, alkyl-alkyl, aryl-aryl, alkenyl-alkyl, alkynyl-alkyl) coupling partners. The diastereoselectivity of the reaction has been examined in both cyclic and acyclic systems. Cyclohexanones give products arising from equatorial attack by the acyl silane. The diastereoselectivity of acyl silane addition to acyclic α-hydroxy ketones can be controlled by varying the protecting group to obtain either Felkin-Ahn or chelation control. The resultant α-silyloxyketone products can be resolved with selectivity factors from 10 to 15 by subjecting racemic ketone benzoin products to CBS reduction. PMID:20392127

  12. Identification of the first fumonisin mycotoxins with three acyl groups by ESI-ITMS and ESI-TOFMS following RP-HPLC separation: palmitoyl, linoleoyl and oleoyl EFB₁ fumonisin isomers from a solid culture of Fusarium verticillioides.

    Science.gov (United States)

    Bartók, T; Tölgyesi, L; Mesterházy, Á; Bartók, M; Szécsi, Á

    2010-12-01

    The aim of this study was to apply RP-HPLC/ESI-ITMS and RP-HPLC/ESI-TOFMS to investigate and characterise six new higher molecular weight fumonisins (three pairs of isomers) extracted from a Fusarium verticillioides-infected solid rice culture. The ITMS and ITMS² spectra clearly indicated the m/z values (960, 984 and 986) of the protonated molecules and the FB₁ toxin-like structures of these compounds, respectively. Moreover, the data evaluation software of the TOFMS equipment unambiguously demonstrated the exact masses of the protonated molecules and the suggested empirical formulae (C₅₀H₈₉NO₁₆, C₅₂H₈₉NO₁₆ and C₅₂H₉₁NO₁₆) of the new fumonisins, with mass accuracy in the range between 0.1 and -1.1 ppm. Subtraction of the empirical formula of FB₁ toxin (C₃₄H₅₉NO₁₅) from these formulae and correction for the mass of water split-off from the fumonisin molecule during ester formation resulted in the empirical formulae of the fumonisin backbone esterifying agents (fatty acids): C₁₆H₃₂O₂ (palmitic acid, PA), C₁₈H₃₂O₂ (linoleic acid, LA) and C₁₈H₃₄O₂ (oleic acid, OA). We denoted the new compounds as esterified FB₁ (EFB₁) toxins, with the suggested names EFB₁ PA, iso-EFB₁ PA, EFB₁ LA, iso-EFB₁ LA, EFB₁ OA and iso-EFB₁ OA. The total amount of these new compounds comprised 0.1% of the FB₁ concentration, which may be rated as significant when it is considered that these new components are significantly more apolar than earlier-described fumonisins, and their uptake into and toxicity elicited in the various tissues of living organisms may therefore also be significantly different from those of other fumonisins.

  13. Heterocyclic inhibitors of AChE acylation and peripheral sites.

    Science.gov (United States)

    Bolognesi, Maria Laura; Andrisano, Vincenza; Bartolini, Manuela; Cavalli, Andrea; Minarini, Anna; Recanatini, Maurizio; Rosini, Michela; Tumiatti, Vincenzo; Melchiorre, Carlo

    2005-01-01

    Notwithstanding the criticism to the so called " cholinergic hypothesis", the therapeutic strategies for the treatment of Alzheimer's disease (AD) have been mainly centered on the restoration of cholinergic functionality and, until the last year, the only drugs licensed for the management of AD were the acetycholinesterase (AChE) inhibitors. Target enzyme AChE consists of a narrow gorge with two separate ligand binding sites: an acylation site at the bottom of the gorge containing the catalytic triad and a peripheral site located at the gorge rim, which encompasses binding sites for allosteric ligands. The aim of this short review is to update the knowledge on heterocyclic AChE inhibitors able to interact with the two sites of enzymes, structurally related to the well known inhibitors physostigmine, rivastigmine and propidium. The therapeutic potential of the dual site inhibithors in inhibiting amyloid-beta aggregatrion and deposition is also briefly summarised.

  14. Analysis of acyl CoA ester intermediates of the mevalonate pathway in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Seker, Tamay; Møller, Kasper; Nielsen, Jens

    2005-01-01

    The mevalonate pathway plays an important role in providing the cell with a number of essential precursors for the synthesis of biomass constituents. With respect to their chemical structure, the metabolites of this pathway can be divided into two groups: acyl esters [acetoacetyl CoA, acetyl CoA,...

  15. Detection and characterization of bacteria from the potato rhizosphere degrading N-acyl-homoserine lactone

    NARCIS (Netherlands)

    Jafra, S.; Przysowa, R.; Czajkowski, A.; Michta, A.; Garbeva, P.; Wolf, van der J.M.

    2006-01-01

    Quorum sensing plays a role in the regulation of soft rot diseases caused by the plant pathogenic bacterium Pectobacterium carotovorum subsp. carotovorum. The signal molecules involved in quorum sensing in P. carotovorum subsp. carotovorum belong to the group of N-acyl homoserine lactones (AHLs). In

  16. Acylation Reactions over Zeolites and Mesoporous Catalysts

    Czech Academy of Sciences Publication Activity Database

    Voláková, Martina; Vitvarová, Dana; Čejka, Jiří

    2009-01-01

    Roč. 2, č. 6 (2009), s. 486-499 ISSN 1864-5631 R&D Projects: GA ČR GA104/07/0383; GA ČR GD203/08/H032; GA MPO FT-TA5/005 Institutional research plan: CEZ:AV0Z40400503 Keywords : acylation * ketones * mesoporous materials * shape-selectivity * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.767, year: 2009

  17. Regioselective enzymatic acylation ofN-acetylhexosamines

    Czech Academy of Sciences Publication Activity Database

    Simerská, Pavla; Pišvejcová, Andrea; Kuzma, Marek; Sedmera, Petr; Křen, Vladimír; Nicotra, S.; Riva, S.

    2004-01-01

    Roč. 29, - (2004), s. 219-225 ISSN 1381-1177 R&D Projects: GA ČR GA203/01/1018; GA MŠk OC D25.002 Grant - others:GA NATO(XX) LST.CLG.980125 Institutional research plan: CEZ:AV0Z5020903 Keywords : n-acetylhexosamines * regioselectivity * enzymatic acylation Subject RIV: EE - Microbiology, Virology Impact factor: 1.547, year: 2004

  18. Intra-group separation of rare earths using new organic phosphorus ligands; Intragruppentrennung Seltener Erden mittels neuer phosphororganischer Liganden

    Energy Technology Data Exchange (ETDEWEB)

    Hadic, Sanela

    2017-10-01

    Rare earth elements (REE) have unique magnetic, photophysical, and chemical properties and they are therefore used in numerous high-technology applications. However, to this day, the isolation of pure rare earths from primary and secondary raw materials is very challenging. In this work, the hydrometallurgical separation of neighboring rare earths (e.g., praseodymium/ neodymium) was optimized with novel selective extraction agents. The separation of rare earths (yttrium and all lanthanides except promethium) was investigated with fourteen new organophosphorus compounds. Oxygen-bearing phosphinic acids yielded good separation results for heavy rare earths (dysprosium to lutetium). For light rare earths (lanthanum to neodymium), particularly high separation factors were realized with synergistic systems containing an aromatic dithiophosphinic acid and a co-extractant, such as tris (2-ethylhexyl) phosphate (TEHP). Optimization studies of the latter extraction system revealed an extremely high separation factor (SF) of 4.21 between praseodymium and neodymium. Another focus of this work was to understand the extraction mechanism. With the aid of nuclear magnetic resonance spectroscopy ({sup 1}H-NMR) and time-resolved laser fluorescence spectroscopy (TRLFS), the complex stoichiometry of promising extraction systems was examined. Studies revealed a dependency between the selectivity for rare earths and the coordination number of the formed complexes. In addition, temperature-dependent extraction experiments were performed and thermodynamic data (ΔG, ΔH, and ΔS) determined. These data provided additional information about the origin of selectivity for neighboring rare earths. With regard to the industrial capability of the investigated extraction systems, the chemical durability of ligands was studied under process-relevant conditions. Qualitative and quantitative analytical methods (e.g., GC-MS) were used in long-term experiments to determine the ligand degradation

  19. Regulation of very-long acyl chain ceramide synthesis by acyl-CoA-binding protein

    DEFF Research Database (Denmark)

    Ferreira, Natalia Santos; Engelsby, Hanne; Neess, Ditte

    2017-01-01

    and cardiovascular diseases, as well as neurological disorders. Here we show that acyl-coenzyme A-binding protein (ACBP) potently facilitates very-long acyl chain ceramide synthesis. ACBP increases the activity of ceramide synthase 2 (CerS2) by more than 2-fold and CerS3 activity by 7-fold. ACBP binds very...... of ACBP(-/-) mice, concomitant with a significant reduction in long- and very-long-chain ceramide levels. Importantly, we show that ACBP interacts with CerS2 and CerS3. Our data uncover a novel mode of regulation of very-long acyl chain ceramide synthesis by ACBP, which we anticipate is of crucial...

  20. Mechanism for adaptive modification during cold acclimation of phospholipid acyl chain composition in Tetrahymena. II. Activities of 2-acyl-sn-glycerol-3-phosphorylcholine and 2-acyl-sn-glycerol-3- phosphorylethanolamine acyltransferases involving the reacylation.

    Science.gov (United States)

    Yoshioka, S; Kameyama, Y; Nozawa, Y

    1984-03-27

    The deacylation-reacylation process is very important for the alteration of phospholipid fatty acyl composition on lowering of growth temperature in Tetrahymena pyriformis (Kameyama, Y., Yoshioka, S. and Nozawa, Y., (1984) Biochim. Biophys. Acta 793, 28-33). Microsomes isolated from Tetrahymena cells have reacylation activities not only for 1-acyl-sn-glycerol-3-phosphorylcholine (1-acyl-GPC) and 1-acyl-sn-glycerol-3-phosphorylethanolamine (1-acyl-GPE) but also for 2-acyl-GPC and 2-acyl-GPE. Unsaturated fatty acyl-CoAs were in general much better substrates than saturated fatty acyl-CoAs for acylations of 1-acyl-GPC and 1-acyl-GPE. The acylation rates for 1-acyl-GPE were almost the same in palmitoleoyl-CoA, oleoyl-CoA, linoleoyl-CoA and gamma-linoleoyl-CoA. However, the acylation activity for 1-acyl-GPC was more than 2-fold higher with palmitoleoyl-CoA than with any other unsaturated fatty acyl-CoAs. In contrast, both 2-acyl-GPC and 2-acyl-GPE acyltransferases did not show a distinct preference for various acyl-CoAs, although palmitoyl-CoA was incorporated into both 2-acylphospholipids at higher rates than into 1-acylphospholipids. These specificities for various acyl-CoAs of 1-acyl- and 2-acyl-GPC and 1-acyl- and 2-acyl-GPE acyltransferases were not changed in the microsomes isolated from cells grown isothermally at 39 degrees C and 15 degrees C and cells shifted from 39 degrees C to 15 degrees C. However, the acylating ratio of linoleoyl-CoA to palmitoyl-CoA, which were chosen as typical unsaturated and saturated fatty acyl-CoAs, in the microsomes from cells grown at 15 degrees C was 1.5-3.0-times higher than in the microsomes from 39 degrees C-grown cells in four acyltransferase activities. These results suggest that the changes of acyl-CoA specificities in reacylation enzyme activities during temperature down-shift would make little contribution to the increase in unsaturated fatty acids in phospholipids, although reacylating enzymes from isothermally grown

  1. Combination of electromembrane extraction and liquid-phase microextraction in a single step: Simultaneous group separation of acidic and basic drugs

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid

    2015-01-01

    Electromembrane extraction (EME) and liquid-phase microextraction (LPME) were combined in a single step for the first time to realize simultaneous and clear group separation of basic and acidic drugs. Using 2-nitrophenyl octyl ether as the supported liquid membrane (SLM) for EME and dihexyl ether...... as the SLM for LPME, basic and acidic drugs were extracted and separated simultaneously from a low pH sample by EME and LPME, respectively. After 15 min of extraction, basic drugs (citalopram and sertraline) were exhaustively extracted, whereas the recoveries for acidic drugs (ketoprofen and ibuprofen) were...... in the range of 76%-86%. Longer extraction time provided higher recoveries for the acidic drugs, but this somewhat deteriorated the group separation. Matrices effects from the coexisting acidic drugs/basic drugs were tested, and we observed that simultaneous EME/LPME was not affected by coexisting drugs...

  2. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-07-01

    Multi-element analysis of dry biological material by neutron activation analysis has to include radiochemical separation. The evaporation process is described in terms of the half-volume. The pretreatment of the samples and the development of the destruction-evaporation apparatus are described. The successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 are described. Results obtained for standard reference materials are summarized. (G.T.H.)

  3. Self-organizing maps for the classification of gallic acylate polyphenols as HSV-1 inhibitors.

    Science.gov (United States)

    Qiu, Xianxiu; Zhong, Meigong; Xiang, Yangfei; Qu, Chang; Pei, Ying; Zhang, Yingjun; Yang, Chongren; Gasteiger, Johann; Xu, Jun; Liu, Zhong; Wang, Yifei

    2014-06-01

    Herpes simplex virus type 1 (HSV-1), a member of the Herpesviridae family, is a ubiquitous, contagious, hostadapted pathogen that causes a wide variety of disease states, such as herpes labialis ("cold sores") and encephalitis. Recently, due to the appearance of acyclovir-resistant HSV-1 mutants, a rapidly growing area of research has been the identification of novel small molecules (whether found in traditional medicine or not) with antiviral activity. One group of these novel pre-drugs is gallic acylate polyphenols. Here, detailed insight into the influence of the chemical structure on anti- HSV-1 activity of gallic acylate polyphenols has been provided based on an exploration of structure-function relationships through self-organizing maps and counterpropagation neural networks. A number of descriptors were investigated to construct optimized models. The resulting model exhibits a correct prediction rate of 90.67%, with active molecule classification accuracy higher than 95.00%, demonstrating that the electrostatic effect and distance between atoms are related to HSV-1 inhibition for these gallic acylate polyphenols. The results provide insights into the influence of the chemical structure on anti-HSV-1 activity of gallic acylate polyphenols.

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

    DEFF Research Database (Denmark)

    Knudsen, J; Jensen, M V; Hansen, J K

    1999-01-01

    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 pool formation and therefore also for the function of LCAs as metabolites and regulators of cellular functions [1]. The major factors controlling the free concentration of cytosol long chain acylCoA ester (LCA) include ACBP [2], sterol carrier protein 2 (SCP2) [3] and fatty acid binding protein (FABP...

  5. Reprogramming Acyl Carrier Protein Interactions of an Acyl-CoA Promiscuous trans-Acyltransferase

    DEFF Research Database (Denmark)

    Ye, Zhixia; Musiol-Kroll, Ewa Maria; Weber, Tilmann

    2014-01-01

    Protein interactions between acyl carrier proteins (ACPs) and trans-acting acyltransferase domains (trans-ATs) are critical for regioselective extender unit installation by many polyketide synthases, yet little is known regarding the specificity of these interactions, particularly for trans...... and for engineering modular polyketide synthases to produce analogs....

  6. Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed.

    Science.gov (United States)

    Cahoon, E B; Coughlan, S J; Shanklin, J

    1997-04-01

    A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1delta9)* and cis-vaccenic (18:1delta11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed delta9 desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known delta9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized delta9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a delta9-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

  7. Aberrant protein acylation is a common observation in inborn errors of acyl-CoA metabolism

    NARCIS (Netherlands)

    Pougovkina, Olga; te Brinke, Heleen; Wanders, Ronald J. A.; Houten, Sander M.; de Boer, Vincent C. J.

    2014-01-01

    Inherited disorders of acyl-CoA metabolism, such as defects in amino acid metabolism and fatty acid oxidation can present with severe clinical symptoms either neonatally or later in life, but the pathophysiological mechanisms are often incompletely understood. We now report the discovery of a novel

  8. Ion channel regulation by protein S-acylation

    Science.gov (United States)

    2014-01-01

    Protein S-acylation, the reversible covalent fatty-acid modification of cysteine residues, has emerged as a dynamic posttranslational modification (PTM) that controls the diversity, life cycle, and physiological function of numerous ligand- and voltage-gated ion channels. S-acylation is enzymatically mediated by a diverse family of acyltransferases (zDHHCs) and is reversed by acylthioesterases. However, for most ion channels, the dynamics and subcellular localization at which S-acylation and deacylation cycles occur are not known. S-acylation can control the two fundamental determinants of ion channel function: (1) the number of channels resident in a membrane and (2) the activity of the channel at the membrane. It controls the former by regulating channel trafficking and the latter by controlling channel kinetics and modulation by other PTMs. Ion channel function may be modulated by S-acylation of both pore-forming and regulatory subunits as well as through control of adapter, signaling, and scaffolding proteins in ion channel complexes. Importantly, cross-talk of S-acylation with other PTMs of both cysteine residues by themselves and neighboring sites of phosphorylation is an emerging concept in the control of ion channel physiology. In this review, I discuss the fundamentals of protein S-acylation and the tools available to investigate ion channel S-acylation. The mechanisms and role of S-acylation in controlling diverse stages of the ion channel life cycle and its effect on ion channel function are highlighted. Finally, I discuss future goals and challenges for the field to understand both the mechanistic basis for S-acylation control of ion channels and the functional consequence and implications for understanding the physiological function of ion channel S-acylation in health and disease. PMID:24821965

  9. An Efficient, Mild and Solvent-Free Synthesis of Benzene Ring Acylated Harmalines

    Directory of Open Access Journals (Sweden)

    Sabira Begum

    2009-12-01

    Full Text Available A facile synthesis of a series of benzene ring acylated analogues of harmaline has been achieved by Friedel-Crafts acylation under solvent-free conditions at room temperature using acyl halides/acid anhydrides and AlCl3. The reaction afforded 10- and 12-acyl analogues of harmaline in good yield, along with minor quantities of N-acyl-tryptamines and 8-acyl analogues of N-acyltryptamines.

  10. Group vs. single mindfulness meditation: exploring avoidance, impulsivity, and weight management in two separate mindfulness meditation settings.

    Science.gov (United States)

    Mantzios, Michail; Giannou, Kyriaki

    2014-07-01

    Recent research has identified that mindfulness meditation in group settings supports people who are trying to lose weight. The present research investigated mindfulness meditation in group and individual settings, and explored the potential impact on weight loss and other factors (i.e. mindfulness, impulsivity, and avoidance) that may assist or hinder weight loss. Specifically, the hypotheses tested were that the group setting assisted dieters more than the individual setting by reducing weight, cognitive-behavioral avoidance, and impulsivity and by increasing mindfulness. Participants (n = 170) who were trying to lose weight were randomly assigned to practice meditation for 6 weeks within a group or independently. Measurements in mindfulness, cognitive-behavioral avoidance, impulsivity, and weight occurred twice (pre- and post-intervention). Results indicated that participants in the group setting lost weight and lowered their levels of cognitive-behavioral avoidance, while impulsivity and mindfulness remained stable. On the other hand, participants in the individual condition lost less weight, while there was an increase in cognitive-behavioral avoidance and mindfulness scores, but a decrease in impulsivity. Seeing that benefits and limitations observed in group settings are not replicated when people meditate alone, this study concluded that mindfulness meditation in individual settings needs to be used with caution, although there are some potential benefits that could aid future weight loss research. © 2014 The International Association of Applied Psychology.

  11. Acylation of arginine in goserelin-loaded PLGA microspheres

    NARCIS (Netherlands)

    Shirangi, Mehrnoosh; Hennink, Wim E.; Somsen, Govert W.; Van Nostrum, Cornelus F.

    2016-01-01

    Acylation of peptides is a well-known but unwanted phenomenon in polyester matrices such as poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres used as controlled release formulations. Acylation normally occurs on lysine residues and the N-terminus of the peptide. The purpose of the present work

  12. Oxidative activation of dihydropyridine amides to reactive acyl donors

    DEFF Research Database (Denmark)

    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...

  13. Understanding Acyl Chain and Glycerolipid Metabolism in Plants

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Stomach regulates energy balance via acylated ghrelin and desacyl ghrelin

    OpenAIRE

    Asakawa, A; Inui, A; Fujimiya, M; Sakamaki, R; Shinfuku, N; Ueta, Y; Meguid, M M; Kasuga, M

    2005-01-01

    Background/Aims: The gastric peptide ghrelin, an endogenous ligand for growth-hormone secretagogue receptor, has two major molecular forms: acylated ghrelin and desacyl ghrelin. Acylated ghrelin induces a positive energy balance, while desacyl ghrelin has been reported to be devoid of any endocrine activities. The authors examined the effects of desacyl ghrelin on energy balance.

  15. Gene synthesis, expression in Escherichia coli, purification and characterization of the recombinant bovine acyl-CoA-binding protein

    DEFF Research Database (Denmark)

    Mandrup, S; Højrup, P; Kristiansen, K

    1991-01-01

    -initiation codon were chosen to allow efficient expression in Escherichia coli as well as in yeast. The synthetic gene was inserted into the expression vector pKK223-3 and expressed in E. coli. In maximally induced cultures, recombinant ACBP constitutes 12-15% of total cellular protein. A fraction highly enriched......-terminal acetyl group. The acyl-CoA-binding characteristics of recombinant ACBP did not differ from those of native ACBP, and the two proteins showed the same ability to induce medium-chain acyl-CoA synthesis by goat mammary-gland fatty acid synthetase. It was concluded that the N-terminal acetyl group......A synthetic gene encoding the 86 amino acid residues of mature acyl-CoA-binding protein (ACBP), and the initiating methionine was constructed. The synthetic gene was assembled from eight partially overlapping oligonucleotides. Codon usage and nucleotides surrounding the ATG translation...

  16. ACCEPTABILITY EVALUATION FOR USING ICRP TISSUE WEIGHTING FACTORS TO CALCULATE EFFECTIVE DOSE VALUE FOR SEPARATE GENDER-AGE GROUPS OF RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    L. V. Repin

    2013-01-01

    Full Text Available An article describes radiation risk factors for several gender-age population groups according to Russian statistical and medical-demographic data, evaluates the lethality rate for separate nosologic forms of malignant neoplasms based on Russian cancer registries according to the method of the International Agency for Cancer Research. Relative damage factors are calculated for the gender-age groups under consideration. The tissue weighting factors recommended by ICRP to calculate effective doses are compared with relative damage factors calculated by ICRP for the nominal population and with similar factors calculated in this work for separate population cohorts in theRussian Federation. The significance of differences and the feasibility of using tissue weighting factors adapted for the Russian population in assessing population risks in cohorts of different gender-age compositions have been assessed.

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

    DEFF Research Database (Denmark)

    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...

  18. Synthesis and Characterization of AlCl3 Impregnated Molybdenum Oxide as Heterogeneous Nano-Catalyst for the Friedel-Crafts Acylation Reaction in Ambient Condition.

    Science.gov (United States)

    Jadhav, Arvind H; Chinnappan, Amutha; Hiremath, Vishwanath; Seo, Jeong Gil

    2015-10-01

    Aluminum trichloride (AlCl3) impregnated molybdenum oxide heterogeneous nano-catalyst was prepared by using simple impregnation method. The prepared heterogeneous catalyst was characterized by powder X-ray diffraction, FT-IR spectroscopy, solid-state NMR spectroscopy, SEM imaging, and EDX mapping. The catalytic activity of this protocol was evaluated as heterogeneous catalyst for the Friedel-Crafts acylation reaction at room temperature. The impregnated MoO4(AlCl2)2 catalyst showed tremendous catalytic activity in Friedel-Crafts acylation reaction under solvent-free and mild reaction condition. As a result, 84.0% yield of acyl product with 100% consumption of reactants in 18 h reaction time at room temperature was achieved. The effects of different solvents system with MoO4(AlCl2)2 catalyst in acylation reaction was also investigated. By using optimized reaction condition various acylated derivatives were prepared. In addition, the catalyst was separated by simple filtration process after the reaction and reused several times. Therefore, heterogeneous MoO4(AlCl2)2 catalyst was found environmentally benign catalyst, very convenient, high yielding, and clean method for the Friedel-Crafts acylation reaction under solvent-free and ambient reaction condition.

  19. Preparation of a technology development roadmap for the Accelerator Transmutation of Waste (ATW) System : report of the ATW separations technologies and waste forms technical working group.

    Energy Technology Data Exchange (ETDEWEB)

    Collins, E.; Duguid, J.; Henry, R.; Karell, E.; Laidler, J.; McDeavitt, S.; Thompson, M.; Toth, M.; Williamson, M.; Willit, J.

    1999-08-12

    In response to a Congressional mandate to prepare a roadmap for the development of Accelerator Transmutation of Waste (ATW) technology, a Technical Working Group comprised of members from various DOE laboratories was convened in March 1999 for the purpose of preparing that part of the technology development roadmap dealing with the separation of certain radionuclides for transmutation and the disposal of residual radioactive wastes from these partitioning operations. The Technical Working Group for ATW Separations Technologies and Waste Forms completed its work in June 1999, having carefully considered the technology options available. A baseline process flowsheet and backup process were identified for initial emphasis in a future research, development and demonstration program. The baseline process combines aqueous and pyrochemical processes to permit the efficient separation of the uranium, technetium, iodine and transuranic elements from the light water reactor (LWR) fuel in the head-end step. The backup process is an all- pyrochemical system. In conjunction with the aqueous process, the baseline flowsheet includes a pyrochemical process to prepare the transuranic material for fabrication of the ATW fuel assemblies. For the internal ATW fuel cycle the baseline process specifies another pyrochemical process to extract the transuranic elements, Tc and 1 from the ATW fuel. Fission products not separated for transmutation and trace amounts of actinide elements would be directed to two high-level waste forms, one a zirconium-based alloy and the other a glass/sodalite composite. Baseline cost and schedule estimates are provided for a RD&D program that would provide a full-scale demonstration of the complete separations and waste production flowsheet within 20 years.

  20. Polymorphism of CRISPR shows separated natural groupings of Shigella subtypes and evidence of horizontal transfer of CRISPR.

    Science.gov (United States)

    Yang, Chaojie; Li, Peng; Su, Wenli; Li, Hao; Liu, Hongbo; Yang, Guang; Xie, Jing; Yi, Shengjie; Wang, Jian; Cui, Xianyan; Wu, Zhihao; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Qiu, Shaofu; Song, Hongbin

    2015-01-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPR) act as an adaptive RNA-mediated immune mechanism in bacteria. They can also be used for identification and evolutionary studies based on polymorphisms within the CRISPR locus. We amplified and analyzed 6 CRISPR loci from 237 Shigella strains belonging to the 4 species groups, as well as 13 Escherichia coli strains. The CRISPR-associated (cas) gene sequence arrays of these strains were screened and compared. The CRISPR sequences from Shigella were conserved among subtypes, suggesting that CRISPR may represent a new identification tool for the detection and discrimination of Shigella species. Secondary structure analysis showed a different stem-loop structure at the terminal repeat, suggesting a distinct recognition mechanism in the formation of crRNA. In addition, the presence of "self-target" spacers and polymorphisms within CRISPR in Shigella indicated a selective pressure for inhibition of this system, which has the potential to damage "self DNA." Homology analysis of spacers showed that CRISPR might be involved in the regulation of virulence transmission. Phylogenetic analysis based on CRISPR sequences from Shigella and E. coli indicated that although phenotypic properties maintain convergent evolution, the 4 Shigella species do not represent natural groupings. Surprisingly, comparative analysis of Shigella repeats with other species provided new evidence for CRISPR horizontal transfer. Our results suggested that CRISPR analysis is applicable for the detection of Shigella species and for investigation of evolutionary relationships.

  1. Polymorphism of CRISPR shows separated natural groupings of Shigella subtypes and evidence of horizontal transfer of CRISPR

    Science.gov (United States)

    Yang, Chaojie; Li, Peng; Su, Wenli; Li, Hao; Liu, Hongbo; Yang, Guang; Xie, Jing; Yi, Shengjie; Wang, Jian; Cui, Xianyan; Wu, Zhihao; Wang, Ligui; Hao, Rongzhang; Jia, Leili; Qiu, Shaofu; Song, Hongbin

    2015-01-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPR) act as an adaptive RNA-mediated immune mechanism in bacteria. They can also be used for identification and evolutionary studies based on polymorphisms within the CRISPR locus. We amplified and analyzed 6 CRISPR loci from 237 Shigella strains belonging to the 4 species groups, as well as 13 Escherichia coli strains. The CRISPR-associated (cas) gene sequence arrays of these strains were screened and compared. The CRISPR sequences from Shigella were conserved among subtypes, suggesting that CRISPR may represent a new identification tool for the detection and discrimination of Shigella species. Secondary structure analysis showed a different stem-loop structure at the terminal repeat, suggesting a distinct recognition mechanism in the formation of crRNA. In addition, the presence of “self-target” spacers and polymorphisms within CRISPR in Shigella indicated a selective pressure for inhibition of this system, which has the potential to damage “self DNA.” Homology analysis of spacers showed that CRISPR might be involved in the regulation of virulence transmission. Phylogenetic analysis based on CRISPR sequences from Shigella and E. coli indicated that although phenotypic properties maintain convergent evolution, the 4 Shigella species do not represent natural groupings. Surprisingly, comparative analysis of Shigella repeats with other species provided new evidence for CRISPR horizontal transfer. Our results suggested that CRISPR analysis is applicable for the detection of Shigella species and for investigation of evolutionary relationships. PMID:26327282

  2. Although it is rapidly metabolized in cultured rat hepatocytes, lauric acid is used for protein acylation.

    Science.gov (United States)

    Rioux, Vincent; Daval, Stéphanie; Guillou, Hervé; Jan, Sophie; Legrand, Philippe

    2003-01-01

    This study was designed to examine the metabolic fate of exogenous lauric acid in cultured rat hepatocytes, in terms of both lipid metabolism and acylation of proteins. Radiolabeled [14C]-lauric acid at 0.1 mM in the culture medium was rapidly taken up by the cells (94.8 +/- 2.2% of the initial radioactivity was cleared from the medium after a 4 h incubation) but its incorporation into cellular lipids was low (24.6 +/- 4.2% of initial radioactivity after 4 h), due to the high beta-oxidation of lauric acid in hepatocytes (38.7 +/- 4.4% after the same time). Among cellular lipids, lauric acid was preferentially incorporated into triglycerides (10.6 +/- 4.6% of initial radioactivity after 4 h). Lauric acid was also rapidly converted to palmitic acid by two successive elongations. Protein acylation was detected after metabolic labeling of the cells with [11,12-3H]-lauric acid. Two-dimensional electrophoresis separation of the cellular proteins and autoradiography evidenced the incorporation of radioactivity into 35 well-resolved proteins. Radiolabeling of several proteins resulted from covalent linkage to the precursor [11,12-3H]-lauric acid or to its elongation product, myristic acid. The covalent linkages between these proteins and lauric acid were broken by base hydrolysis, indicating that the linkage was of the thioester or ester-type. Endogenous myristic acid produced by lauric acid elongation was used for both protein N-myristoylation and protein S-acylation. Therefore, these results show for the first time that, although it is rapidly metabolized in hepatocytes, exogenous lauric acid is a substrate for the acylation of liver proteins.

  3. Acylated pelargonidin 3-sambubioside-5-glucosides in Matthiola incana.

    Science.gov (United States)

    Saito, N; Tatsuzawa, F; Hongo, A; Win, K W; Yokoi, M; Shigihara, A; Honda, T

    1996-04-01

    Ten acylated pelargonidin 3-sambubioside-5-glucosides were isolated from the red-purple flowers of Matthiola incana, and also pelargonidin 3-glucoside was isolated from the brownish-red flowers of this plant. FAB mass measurements of 10 acylated anthocyanins gave their molecular ions [M]+ at 903-1195 m/z, which were based on acylated pelargonidin 3-sambubioside-5-glucosides with malonic acid, sinapic acid, p-coumaric acid, caffeic acid and/or ferulic acid. This was confirmed by the analysis of NMR spectra and the experiments of acid and alkaline hydrolysis. By spectral and chemical methods, seven of the 10 pigments were determined to be pelargonidin 3-O-[2-O-(2-O-(acyl-I)-beta-D-xylopyranosyl)- 6-O-(acyl-II)-beta-D-glucopyranoside]-5-O-[6-O-(malonyl)-beta-D- glucopyranoside], in which acyl moieties varied between sinapic, ferulic, caffeic and p-coumaric acids. The occurrence of these pigments was examined in 10 red-purple, 10 salmon-pink, three apricot and three copper colour cultivars of M. incana by HPLC. The acylated pelargonidin 3-sambubioside-5-glucosides were present as the dominant pigments in the red-purple, salmon-pink and apricot colour cultivars. On the other hand, pelargonidin 3-glucoside was present as a dominant anthocyanin in the copper colour cultivars and also pelargonidin 3-sambubioside-5-glucoside was confirmed by HPLC as a minor pigment in the copper colour flowers.

  4. Protonic equilibria in the reductive half-reaction of the medium-chain acyl-CoA dehydrogenase

    OpenAIRE

    Rudik, Irina; Ghisla, Sandro; Thorpe, Colin

    1998-01-01

    Oxidation of thioester substrates in the medium-chain acyl-CoA dehydrogenase involves α-proton abstraction by the catalytic base, Glu376, with transfer of a β-hydride equivalent to the flavin prosthetic group. Polarization of bound acyl-CoA derivatives by the recombinant human liver enzyme has been studied with 4-thia-trans-2-enoyl-CoA analogues. Polarization is maximal at low pH, with an apparent pK of 9.2 for complexes with the C8 analogue, and progressively lower pK values as the length of...

  5. Thermodynamics of Ligand Binding to Acyl-Coenzyme A Binding Protein Studied by Titration Calorimetry

    DEFF Research Database (Denmark)

    Færgeman, Nils Joakim; Sigurskjold, Bent Walther; Kragelund, Birthe 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-...

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

    DEFF Research Database (Denmark)

    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-...

  7. Novel Bradykinin Analogues Modified in the N-Terminal Part of the Molecule with a Variety of Acyl Substituents

    Czech Academy of Sciences Publication Activity Database

    Sleszynska, M.; Wierzba, T. H.; Malinowski, K.; Tůmová, Tereza; Lammek, B.; Slaninová, Jiřina; Prahl, A.

    2012-01-01

    Roč. 18, č. 2 (2012), s. 117-124 ISSN 1573-3149 Institutional research plan: CEZ:AV0Z40550506 Keywords : bradykinin analogues * B-2 receptor antagonists * bulky acyl groups * in vivo rat blood pressure test * in vitro rat uterus test Subject RIV: CE - Biochemistry Impact factor: 1.280, year: 2012

  8. Synthesis of arsinolipids. II. A non-isosteric analogue of fully acylated cardiolipin.

    Science.gov (United States)

    Ioannou, Panayiotis V

    2002-08-01

    2-Hydroxypropane-1,3-bis(arsonic acid) after six successive reactions gives the arsinolipid 2-acyloxy-As, As'-bis[2,3-di(acyloxy)propyl]propane-1,3-diylbis(arsinic acid) in 20-40% overall yields. This arsinolipid is a non-isosteric analogue of the fully acylated cardiolipin. The R- and S-glycidol, used to create the backbone of the lipid, give the optically active RR and SS, respectively, arsinolipids, while the rac-glycidol produces a mixture of diastereomers (a racemic pair, RR and SS, and two meso forms with an RS configuration). Some properties of these arsinolipids are described, from which the most interesting are the facile hydrolysis of the middle acyl group and their tendency to absorb environmental water.

  9. Genes of ACYL CARRIER PROTEIN Family Show Different Expression Profiles and Overexpression of ACYL CARRIER PROTEIN 5 Modulates Fatty Acid Composition and Enhances Salt Stress Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Jiexue Huang

    2017-06-01

    Full Text Available Acyl carrier proteins (ACPs are a group of small acidic proteins functioning as important cofactors in the de novo synthesis of fatty acids. In Arabidopsis, ACPs are encoded by a small gene family comprising five plastid members, AtACP1 to AtACP5, and three mitochondrial members. The biological functions and the transcriptional responses to abiotic stresses of most AtACPs have yet to be elucidated. The present study extends previous findings and provides new knowledge on the function of ACPs by examining the responses of AtACP-encoding genes to several abiotic stresses and, in particular, the role of AtACP5 in the adaptation to salt stress. Phylogenetic analysis showed that AtACP1, AtACP2, AtACP3, and AtACP5 can be classified into one group and separated from a group comprising AtACP4 and ACP homologs from related species. Quantitative RT-PCR analysis revealed that the expression of AtACP1, AtACP2, and AtACP3 was induced by drought. Both iron deficiency and nitrogen starvation resulted in down-regulation of AtACP4. The most pronounced response was observed for AtACP5, the expression of which was dramatically decreased by salt stress. Knock-out of AtACP5 showed increased sensitivity to NaCl stress, whereas transgenic lines overexpressing AtACP5 displayed increased salt tolerance relative to the wild-type. Overexpression of AtACP5 further led to an altered composition of fatty acids, mainly a decrease of oleic acid (C18:1 and an increase of palmitic acid (C16:0, and to a lower Na+/K+ ratio when compared to the salt stressed wild-type. The comprehensive transcriptional information on the small plastid AtACP gene family in response to various abiotic stresses and the further investigation of the AtACP5 indicate that AtACP5 might be critical for salt tolerance through alterations of the composition of fatty acids and, subsequently, the Na+/K+ ratio.

  10. Genes of ACYL CARRIER PROTEIN Family Show Different Expression Profiles and Overexpression of ACYL CARRIER PROTEIN 5 Modulates Fatty Acid Composition and Enhances Salt Stress Tolerance in Arabidopsis.

    Science.gov (United States)

    Huang, Jiexue; Xue, Caiwen; Wang, Han; Wang, Lisai; Schmidt, Wolfgang; Shen, Renfang; Lan, Ping

    2017-01-01

    Acyl carrier proteins (ACPs) are a group of small acidic proteins functioning as important cofactors in the de novo synthesis of fatty acids. In Arabidopsis , ACPs are encoded by a small gene family comprising five plastid members, AtACP1 to AtACP5 , and three mitochondrial members. The biological functions and the transcriptional responses to abiotic stresses of most AtACPs have yet to be elucidated. The present study extends previous findings and provides new knowledge on the function of ACPs by examining the responses of AtACP-encoding genes to several abiotic stresses and, in particular, the role of AtACP5 in the adaptation to salt stress. Phylogenetic analysis showed that AtACP1, AtACP2, AtACP3, and AtACP5 can be classified into one group and separated from a group comprising AtACP4 and ACP homologs from related species. Quantitative RT-PCR analysis revealed that the expression of AtACP1, AtACP2 , and AtACP3 was induced by drought. Both iron deficiency and nitrogen starvation resulted in down-regulation of AtACP4 . The most pronounced response was observed for AtACP5 , the expression of which was dramatically decreased by salt stress. Knock-out of AtACP5 showed increased sensitivity to NaCl stress, whereas transgenic lines overexpressing AtACP5 displayed increased salt tolerance relative to the wild-type. Overexpression of AtACP5 further led to an altered composition of fatty acids, mainly a decrease of oleic acid (C18:1) and an increase of palmitic acid (C16:0), and to a lower Na + /K + ratio when compared to the salt stressed wild-type. The comprehensive transcriptional information on the small plastid AtACP gene family in response to various abiotic stresses and the further investigation of the AtACP5 indicate that AtACP5 might be critical for salt tolerance through alterations of the composition of fatty acids and, subsequently, the Na + /K + ratio.

  11. Separable algebras

    CERN Document Server

    Ford, Timothy J

    2017-01-01

    This book presents a comprehensive introduction to the theory of separable algebras over commutative rings. After a thorough introduction to the general theory, the fundamental roles played by separable algebras are explored. For example, Azumaya algebras, the henselization of local rings, and Galois theory are rigorously introduced and treated. Interwoven throughout these applications is the important notion of étale algebras. Essential connections are drawn between the theory of separable algebras and Morita theory, the theory of faithfully flat descent, cohomology, derivations, differentials, reflexive lattices, maximal orders, and class groups. The text is accessible to graduate students who have finished a first course in algebra, and it includes necessary foundational material, useful exercises, and many nontrivial examples.

  12. Lanthanum Tricyanide-Catalyzed Acyl Silane-Ketone Benzoin Additions

    Science.gov (United States)

    Tarr, James C.; Johnson, Jeffrey S.

    2009-01-01

    Lanthanum tricyanide efficiently catalyzes a benzoin-type coupling between acyl silanes and ketones. Yields range from moderate to excellent over a broad substrate scope encompassing aryl, alkyl, electron-rich, and sterically hindered ketones. PMID:19655731

  13. Dynamical Mean-Field Theory Plus Numerical Renormalization-Group Study of Spin-Orbital Separation in a Three-Band Hund Metal.

    Science.gov (United States)

    Stadler, K M; Yin, Z P; von Delft, J; Kotliar, G; Weichselbaum, A

    2015-09-25

    We show that the numerical renormalization group is a viable multi-band impurity solver for dynamical mean-field theory (DMFT), offering unprecedented real-frequency spectral resolution at arbitrarily low energies and temperatures. We use it to obtain a numerically exact DMFT solution to the Hund metal problem for a three-band model on a Bethe lattice at 1/3 filling. The ground state is a Fermi liquid. The one-particle spectral function undergoes a coherence-incoherence crossover with increasing temperature, with spectral weight being transferred from low to high energies. Further, it exhibits a strong particle-hole asymmetry. In the incoherent regime, the self-energy displays approximate power-law behavior for positive frequencies only. The spin and orbital spectral functions show "spin-orbital separation": spin screening occurs at much lower energies than orbital screening. The renormalization group flows clearly reveal the relevant physics at all energy scales.

  14. Femtosecond probing of photodissociation dynamics in acyl cyanides

    Science.gov (United States)

    Lee, I.-Ren; Chung, Yu-Chieh; Chen, Wei-Kan; Hong, Xiu-Ping; Cheng, Po-Yuan

    2001-12-01

    The photodissociation of two acyl cyanide compounds, R-C(O)-CN, where R=methyl and tert-butyl groups, has been investigated using femtosecond time-resolved laser-induced fluorescence (LIF) spectroscopy. Both compounds were excited by two-photon excitation at a total energy of ˜6.4 eV and the formation of the free CN(X) radical products was probed in real time by monitoring the CN X→B LIF signal. The results revealed that the temporal evolution of the CN(X) formation can be well characterized by delayed biexponential rise functions with time constants in the picosecond time scale, indicating that the dissociation occurs via a complex-mode mechanism. We proposed a dissociation mechanism involving two discernable stages to account for the observed temporal behaviors as well as previous photofragment translational spectroscopic results reported by other groups. Our analyses suggested that the selectivity between the C-CN and C-R bond cleavage is determined by the competition between the adiabatic and nonadiabatic dynamics of the S2 state. The results also indicated that the adiabatic dissociation process occurring on the S2 surface is not statistical. We speculate that this nonstatistical dissociation behavior is due to an initial nonuniform phase space distribution and a slow intramolecular vibrational energy redistribution process that prevents the system from sampling the entire phase space before the reaction completes.

  15. Safety Assessment of Acyl Glucuronides - A Simplified Paradigm.

    Science.gov (United States)

    Smith, Dennis A; Hammond, Timothy; Baillie, Thomas A

    2018-03-20

    While simple O- (ether-linked) and N-glucuronide drug conjugates generally are unreactive and considered benign from a safety perspective, the acyl glucuronides that derive from metabolism of carboxylic acid-containing xenobiotics can exhibit a degree of chemical reactivity that is dependent upon their molecular structure. As a result, concerns have arisen over the safety of acyl glucuronides as a class, several members of which have been implicated in the toxicity of their respective parent drugs. However, direct evidence in support of these claims remains sparse, and due to frequently encountered species differences in the systemic exposure to acyl glucuronides (both of parent drug and oxidized derivatives thereof), coupled with their instability in aqueous media and potential to undergo chemical rearrangement (acyl migration), qualification of these conjugates by traditional safety assessment methods can be very challenging. In this Commentary, we discuss alternative (non-acyl glucuronide) mechanisms by which carboxylic acids may cause serious adverse reactions, and propose a novel, practical approach to compare systemic exposure to acyl glucuronide metabolites in humans to that in animal species used in preclinical safety assessment based on relative estimates of the total body burden of these circulating conjugates. The American Society for Pharmacology and Experimental Therapeutics.

  16. Plasma fatty acyl-carnitines during 8 Weeks of overfeeding: relation to diet energy expenditure and body composition: the PROOF study.

    Science.gov (United States)

    Bray, George A; Redman, Leanne M; de Jonge, Lilian; Rood, Jennifer; Sutton, Elizabeth F; Smith, Steven R

    2018-01-24

    Overfeeding is a strategy for evaluating the effects of excess energy intake. In this secondary analysis we tested the possibility that different levels of dietary protein might differentially modify the response of fatty acyl-carnitines to overfeeding. Twenty-three healthy adult men and women were overfed by 40% for 8 weeks while in-patients with diets containing 5% (LPD), 15% (NPD) or 25% (HPD) protein. Plasma fatty acyl-carnitines were measured by gas chromatography/mass spectrometry (GC/MS) at baseline and after 8 weeks of overfeeding. Measurements included: body composition by DXA, energy expenditure by ventilated hood and doubly-labeled water, fat cell size from subcutaneous fat biopsies, and fat distribution by CT scan. Analysis was done on 5 groups of fatty acyl-carnitines identified by principal components analysis and 6 individual short-chain fatty acyl carnitines. Higher protein intake was associated with significantly lower 8 week levels of medium chain fatty acids and C2, C4-OH and C 6:1, but higher values of C3 and C5:1 acyl-carnitines derived from essential amino acids. In contrast energy and fat intake were only weakly related to changes in fatty acyl-carnitines. A decease or smaller rise in 8 week medium chain acyl-carnitines was associated with an increase in sleeping energy expenditure (P = 0.0004), and fat free mass (P < 0.0001) and a decrease in free fatty acid concentrations (FFA) (P = 0.0067). In contrast changes in short-chain fatty acyl-carnitines were related to changes in resting energy expenditure (P = 0.0026), and fat free mass (P = 0.0007), and C4-OH was positively related to FFA (P = 0006). Protein intake was the major factor influencing changes in fatty acyl carnitines during overfeeding with higher values of most acyl-fatty acids on the low protein diet. The association of dietary protein and fat intake may explain the changes in energy expenditure and metabolic variables resulting in the observed

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

    DEFF Research Database (Denmark)

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

    1994-01-01

    The dissociation constants for octanoyl-CoA, dodecanoyl-CoA and hexadecanoyl-CoA binding to acyl-CoA-binding protein (ACBP) were determined by using titration microcalorimetry. The KD values obtained, (0.24 +/- 0.02) x 10(-6) M, (0.65 +/- 0.2) x 10(-8) M and (0.45 +/- 0.2) x 10(-13) M respectively......, 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...

  18. Trans-unsaturated lipid dynamics: modulation of dielaidoylphosphatidylcholine acyl chain motion by ethanol.

    Science.gov (United States)

    Dalton, L A; Miller, K W

    1993-01-01

    Acyl chain dynamics of the trans-unsaturated lipid, dielaidoylphosphatidylcholine (DEPC), were studied by conventional and saturation transfer electron paramagnetic resonance spectroscopy of aqueous dispersions of DEPC spin labeled with lecithins having doxyl groups at positions 5, 10, and 14 on the sn-2 chain. The gel to liquid crystalline transition is concerted with simultaneous increases in rotational motion about the long axis of the acyl chain (libration) and in gauche-trans conformational interconversions (wobble). Relative to saturated lecithins at similar reduced temperatures the double bond (a) slowed libration by an order of magnitude in both phases, while wobble motions were several times slower, and (b)-produced a pronounced stiffness of the acyl chain near the double bond. Ethanol (0-1.6 M), in addition to its well-known colligative effect on the phase transition, was found to decrease the bilayer order in a concentration-dependent manner. This effect was smaller in the gel than in the liquid crystalline phase, most pronounced next to the double bond, and weakest deep in the bilayer. Ethanol affected slow motions little in the gel phase but wobble and libration correlation times were markedly decreased in the liquid crystalline phase. PMID:8274650

  19. Maleimide scavenging enhances determination of protein S-palmitoylation state in acyl-exchange methods

    Science.gov (United States)

    Hurst, Charlotte H.; Turnbull, Dionne; Plain, Fiona; Fuller, William; Hemsley, Piers A.

    2017-01-01

    S-palmitoylation (S-acylation) is an emerging dynamic post-translational modification of cysteine residues within proteins. Current assays for protein S-palmitoylation involve either in vivo labelling or chemical cleavage of S-palmitoyl groups to reveal a free cysteine sulfhydryl that can be subsequently labelled with an affinity handle (acyl-exchange). Assays for protein S-palmitoylation using acyl-exchange chemistry therefore require blocking of non-S-palmitoylated cysteines, typically using N-ethylmaleimide, to prevent non-specific detection. This in turn necessitates multiple precipitation based clean-up steps to remove reagents between stages, often leading to variable sample loss, reduced signal or protein aggregation. These combine to reduce the sensitivity, reliability and accuracy of these assays and also requires a substantial amount of time to perform. By substituting these precipitation steps with chemical scavenging of N-ethylmaleimide by 2,3-dimethyl-1,3-butadiene in an aqueous Diels-Alder 4+2 cyclo-addition reaction it is possible to greatly improve sensitivity and accuracy while reducing hands-on and overall time required for assays. PMID:28193150

  20. New anthrarobin acyl derivatives as butyrylcholinesterase inhibitors: synthesis, in vitro and in silico studies

    Directory of Open Access Journals (Sweden)

    Mehreen Lateef

    2017-07-01

    Full Text Available To treat Alzheimer's disease (AD, the available candidates are effective only against mild AD or have side effects. So, a study was planned to synthesis new candidates that may have good potential to treat AD. A series of new anthrarobin acyl derivatives (2–8 were synthesized by the reaction of anthrarobin (1 and acetic anhydride/acyl chlorides. The product were characterized by 1H NMR and EI-MS, and evaluated for butyrylcholinesterase (BuChE inhibition activity. Compounds 5 and 4 showed notable BuChE inhibitory potential with IC50 5.3 ± 1.23 and 17.2 ± 0.47 μM, respectively when compared with the standard eserine (IC50 7.8 ± 0.27 μM, compound 5 showed potent BuChE inhibition potential than the standard eserine. The active compounds 5 and 4 have acyl groups at 2-OH and 10-OH positions which may be responsible for inhibitory potential as this orientation is absent in other products. In silico studies of 5 and 4 products revealed the high inhibitory potential due to stable binding of ligand with the BuChE active sites with docking energy score −18.8779 kcal/mol and −23.1159 kcal/mol, respectively. Subsequently, compound 5 that have potent BuChE inhibitory activity could be the potential candidate for drug development for Alzheimer’s disease.

  1. Yeast acyl-CoA-binding protein: acyl-CoA-binding affinity and effect on intracellular acyl-CoA pool size

    DEFF Research Database (Denmark)

    Knudsen, J; Faergeman, N J; Skøtt, H

    1994-01-01

    Acyl-CoA-binding protein (ACBP) is a 10 kDa protein characterized in vertebrates. We have isolated two ACBP homologues from the yeast Saccharomyces carlsbergensis, named yeast ACBP types 1 and 2. Both proteins contain 86 amino acid residues and are identical except for four conservative substitut...... resulted in a significant expansion of the intracellular acyl-CoA pool. Finally, Southern-blotting analysis of the two genes encoding ACBP types 1 and 2 in S. carlsbergensis strongly indicated that this species is a hybrid between S. cerevisiae and Saccharomyces monacensis....

  2. Separation of actinides from lanthanides

    Science.gov (United States)

    Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

    1989-01-01

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  3. Carbapenems and SHV-1 β-Lactamase Form Different Acyl-Enzyme Populations in Crystals and Solution

    Science.gov (United States)

    Kalp, Matthew; Carey, Paul R.

    2009-01-01

    The reactions between single crystals of the SHV-1 β-lactamase enzyme and the carbapenems, meropenem, imipenem and ertapenem, have been studied by Raman microscopy. Aided by quantum mechanical calculations, major populations of two acyl-enzyme species, a labile Δ2-pyrroline and a more tightly bound Δ1-pyrroline, have been identified for all three compounds. These isomers differ only in the position of the double bond about the carbapenem nucleus. This discovery is consonant with X-ray crystallographic findings that also identified two populations for meropenem bound in SHV-1: one with the acyl C=O group in the oxyanion hole and the second with the acyl group rotated 180 degrees compared to its expected position [Nukaga, M., Bethel, C. R., Thomson, J. M., Hujer, A. M., Distler, A. M., Anderson, V. E., Knox, J. R., and Bonomo, R. A. (2008) Journal of the American Chemical Society]. When crystals of the Δ1 and Δ2 containing acyl-enzymes were exposed to solutions with no carbapenem, rapid deacylation of the Δ2 species was observed by kinetic Raman experiments. However, no change in the Δ1 population was observed over 1 hour, the effective lifetime of the crystal. These observations lead to the hypothesis that the stable Δ1 species is due to the form seen by X-ray with the acyl carbonyl outside the oxyanion hole, while the Δ2 species corresponds to the form with the carbonyl inside the oxyanion hole. Soak-in and soak-out Raman experiments also demonstrated that tautomeric exchange between the Δ1 and Δ2 forms does not occur on the crystalline enzyme. When meropenem or ertapenem were reacted with SHV-1 in solution, the Raman difference spectra demonstrated that only a major population corresponding to the Δ1 acyl-enzyme could be detected. The 1003 cm-1 mode of the phenyl ring positioned on the C3 side chain of ertapenem acts as an effective internal Raman intensity standard and the ratio of its intensity to that of the 1600 cm-1 feature of Δ1 provides an

  4. Yeast acyl-CoA-binding protein: acyl-CoA-binding affinity and effect on intracellular acyl-CoA pool size

    DEFF Research Database (Denmark)

    Knudsen, J; Faergeman, N J; Skøtt, H

    1994-01-01

    Acyl-CoA-binding protein (ACBP) is a 10 kDa protein characterized in vertebrates. We have isolated two ACBP homologues from the yeast Saccharomyces carlsbergensis, named yeast ACBP types 1 and 2. Both proteins contain 86 amino acid residues and are identical except for four conservative substitut...

  5. Photoprotection and the photophysics of acylated anthocyanins.

    Science.gov (United States)

    da Silva, Palmira Ferreira; Paulo, Luísa; Barbafina, Adrianna; Eisei, Fausto; Quina, Frank H; Maçanita, António L

    2012-03-19

    The proposed role of anthocyanins in protecting plants against excess solar radiation is consistent with the occurrence of ultrafast (5-25 ps) excited-state proton transfer as the major de-excitation pathway of these molecules. However, because natural anthocyanins absorb mainly in the visible region of the spectra, with only a narrow absorption band in the UV-B region, this highly efficient deactivation mechanism would essentially only protect the plant from visible light. On the other hand, ground-state charge-transfer complexes of anthocyanins with naturally occurring electron-donor co-pigments, such as hydroxylated flavones, flavonoids, and hydroxycinnamic or benzoic acids, do exhibit high UV-B absorptivities that complement that of the anthocyanins. In this work, we report a comparative study of the photophysics of the naturally occurring anthocyanin cyanin, intermolecular cyanin-coumaric acid complexes, and an acylated anthocyanin, that is, cyanin with a pendant coumaric ester co-pigment. Both inter- and intramolecular anthocyanin-co-pigment complexes are shown to have ultrafast energy dissipation pathways comparable to those of model flavylium cation-co-pigment complexes. However, from the standpoint of photoprotection, the results indicate that the covalent attachment of co-pigment molecules to the anthocyanin represents a much more efficient strategy by providing the plant with significant UV-B absorption capacity and at the same time coupling this absorption to efficient energy dissipation pathways (ultrafast internal conversion of the complexed form and fast energy transfer from the excited co-pigment to the anthocyanin followed by adiabatic proton transfer) that avoid net photochemical damage. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Crystallization of the C-terminal domain of the mouse brain cytosolic long-chain acyl-CoA thioesterase

    Energy Technology Data Exchange (ETDEWEB)

    Serek, Robert; Forwood, Jade K. [School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia); Hume, David A. [School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia); Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072 (Australia); Cooperative Research Centre for Chronic Inflammatory Diseases, University of Queensland, Brisbane, Queensland 4072 (Australia); Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane, Queensland 4072 (Australia); Martin, Jennifer L.; Kobe, Bostjan, E-mail: b.kobe@uq.edu.au [School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia); Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072 (Australia); Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane, Queensland 4072 (Australia)

    2006-02-01

    The C-terminal domain of the mouse long-chain acyl-CoA thioesterase has been expressed in bacteria and crystallized by vapour diffusion. The crystals diffract to 2.4 Å resolution. The mammalian long-chain acyl-CoA thioesterase, the enzyme that catalyses the hydrolysis of acyl-CoAs to free fatty acids, contains two fused 4HBT (4-hydroxybenzoyl-CoA thioesterase) motifs. The C-terminal domain of the mouse long-chain acyl-CoA thioesterase (Acot7) has been expressed in bacteria and crystallized. The crystals were obtained by vapour diffusion using PEG 2000 MME as precipitant at pH 7.0 and 290 K. The crystals have the symmetry of space group R32 (unit-cell parameters a = b = 136.83, c = 99.82 Å, γ = 120°). Two molecules are expected in the asymmetric unit. The crystals diffract to 2.4 Å resolution using the laboratory X-ray source and are suitable for crystal structure determination.

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

    Science.gov (United States)

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

    2016-01-01

    Plant-specialized (or secondary) metabolites represent an important source of high-value chemicals. In order to generate a new production platform for these metabolites, an attempt was made to produce flavonoids in rice seeds. Metabolome analysis of these transgenic rice seeds using liquid chromatography-photodiode array-quadrupole time-of-flight mass spectrometry was performed. A total of 4392 peaks were detected in both transgenic and non-transgenic rice, 20–40% of which were only detected in transgenic rice. Among these, 82 flavonoids, including 37 flavonols, 11 isoflavones, and 34 flavones, were chemically assigned. Most of the flavonols and isoflavones were O-glycosylated, while many flavones were O-glycosylated and/or C-glycosylated. Several flavonoids were acylated with malonyl, feruloyl, acetyl, and coumaroyl groups. These glycosylated/acylated flavonoids are thought to have been biosynthesized by endogenous rice enzymes using newly synthesized flavonoids whose biosynthesis was catalysed by exogenous enzymes. The subcellular localization of the flavonoids differed depending on the class of aglycone and the glycosylation/acylation pattern. Therefore, flavonoids with the intended aglycones were efficiently produced in rice seeds via the exogenous enzymes introduced, while the flavonoids were variously glycosylated/acylated by endogenous enzymes. The results suggest that rice seeds are useful not only as a production platform for plant-specialized metabolites such as flavonoids but also as a tool for expanding the diversity of flavonoid structures, providing novel, physiologically active substances. PMID:26438413

  8. Acylated flavonol glycosides from the forage legume, Onobrychis viciifolia (sainfoin).

    Science.gov (United States)

    Veitch, Nigel C; Regos, Ionela; Kite, Geoffrey C; Treutter, Dieter

    2011-04-01

    Ten acylated flavonol glycosides were isolated from aqueous acetone extracts of the aerial parts of the forage legume, Onobrychis viciifolia, and their structures determined using spectroscopic methods. Among these were eight previously unreported examples which comprised either feruloylated or sinapoylated derivatives of 3-O-di- and 3-O-triglycosides of kaempferol (3,5,7,4'-tetrahydroxyflavone) or quercetin (3,5,7,3',4'-pentahydroxyflavone). The diglycosides were acylated at the primary Glc residue of O-α-Rhap(1→6)-β-Glcp (rutinose), whereas the triglycosides were acylated at the terminal Rha residues of the branched trisaccharides, O-α-Rhap(1→2)[α-Rhap(1→6)]-β-Galp or O-α-Rhap(1→2)[α-Rhap(1→6)]-β-Glcp. Identification of the primary 3-O-linked hexose residues as either Gal or Glc was carried out by negative ion electrospray and serial MS, and cryoprobe NMR spectroscopy. Analysis of UV and MS spectra of the acylated flavonol glycosides provided additional diagnostic features relevant to direct characterisation of these compounds in hyphenated analyses. Quantitative analysis of the acylated flavonol glycosides present in different aerial parts of sainfoin revealed that the highest concentrations were in mature leaflets. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties

    Science.gov (United States)

    Kang, Jongeun; Lee, Hyunseung; Kim, Young-Nam; Yeom, Areum; Jeong, Heejeong; Lim, Yong Taik; Hong, Kwan Soo

    2013-09-01

    Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe2O4 MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T2 relaxivities ( r 2) at 4.7 T and room temperature in the range of 60 to 300 mM-1s-1, depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe2O4 MNPs could be used as initial base cores of MRI T2 CAs, with almost unique T2 relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis.

  10. Impaired postprandial fullness in Type 2 diabetic subjects is rescued by acute exercise independently of total and acylated ghrelin

    DEFF Research Database (Denmark)

    Knudsen, Sine H; Karstoft, Kristian; Solomon, Thomas

    2013-01-01

    be eaten, nausea, and fullness) and circulating levels of glucose, insulin, and total and acylated ghrelin were measured at baseline and in response to a 75 g oral glucose load, provided immediately after an aerobic exercise bout (1 h at 50% Wmax) or no exercise (rest trial), on two separate occasions......Ghrelin levels are suppressed in obese subjects and subjects with Type 2 diabetes mellitus (T2DM). Exercise-stimulated decreases in plasma ghrelin are a proposed mediator of exercise-induced satiety in healthy subjects. However, exercise-induced satiety and the impact of impaired ghrelin levels....... Baseline levels of total (284.4 ± 15.9 and 397.6 ± 35.2 pmol/l) and acylated ghrelin (7.9 ± 1.0 and 13.7 ± 1.2 pmol/l) were lower in subjects with T2DM compared with healthy subjects (P

  11. Functionalizing porous aromatic frameworks with polar organic groups for high-capacity and selective CO2 separation: a molecular simulation study.

    Science.gov (United States)

    Babarao, Ravichandar; Dai, Sheng; Jiang, De-en

    2011-04-05

    Porous aromatic frameworks (PAFs) were recently synthesized with the highest surface area to date; one such PAF (PAF-1) has diamond-like structure with biphenyl building blocks and exhibits exceptional thermal and hydrothermal stabilities. Herein, we computationally design new PAFs by introducing polar organic groups to the biphenyl unit and then investigate their separating power toward CO(2) by using grand-canonical Monte Carlo (GCMC) simulations. Among these functional PAFs, we found that tetrahydrofuran-like ether-functionalized PAF-1 shows higher adsorption capacity for CO(2) at 1 bar and 298 K (10 mol per kilogram of adsorbent) and also much higher selectivities for CO(2)/CH(4), CO(2)/N(2), and CO(2)/H(2) mixtures when compared with the amine functionality. The electrostatic interactions are found to play a dominant role in the high CO(2) selectivities of functional PAFs, as switching off atomic charges would decrease the selectivity by an order of magnitude. This work suggests that functionalizing porous frameworks with tetrahydrofuran-like ether groups is a promising way to increase CO(2) adsorption capacity and selectivity, especially at ambient pressures.

  12. Association between platelet glycoprotein Ia C807T gene polymorphism and ischemic stroke: a meta-analysis in a separate ethnic group.

    Science.gov (United States)

    Huang, Xiao-Yun; Fu, Wen-Jin; Mei, Zhi-Zhong; Yu, Ying-Li; Huang, Yi-Hong; Lin, Han; Chen, Jian-Jun; Wang, Ming-Xia; Guan, Shao-Bing; Fang, Hao-Wei

    2017-11-30

    Many studies have been examined the association of platelet glycoprotein (GP) Ia C807T polymorphism with ischemic stroke (IS) susceptibility. However, the results of these studies are inconsistent. To further assess the effects of GP Ia C807T polymorphism on the risk of IS, a meta-analysis was performed in a separate ethnic group. Relevant studies were identified using PubMed and Chinese databases through January 2017. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. Finally, 13 studies contained 2438 IS cases and 2308 controls included. In the total analyses, a significantly elevated risk of IS was associated with all variants of GP Ia C807T in the Chinese population (T vs C: OR = 1.24, 95% CI = 1.09-1.40; TT vs CC: OR = 1.59, 95% CI = 1.17-2.15; TT and CT combined vs CC: OR = 1.32, 95% CI = 1.09-1.59; TT vs CC and CT: OR = 1.35, 95% CI = 1.04-1.76). In the subgroup analyses stratified by ethnicity and geographic areas, it revealed the significant results in Chinese Han and in South China. This meta-analysis provides the evidence that GP Ia C807T polymorphism may contribute to the IS development in the Chinese population, especially in South China, and further studies in other ethic groups are required for definite conclusions.

  13. Detecting and characterizing N-acyl-homoserine lactone signal molecules by thin-layer chromatography

    Science.gov (United States)

    Shaw, Paul D.; Ping, Gao; Daly, Sean L.; Cha, Chung; Cronan, John E.; Rinehart, Kenneth L.; Farrand, Stephen K.

    1997-01-01

    Many Gram-negative bacteria regulate gene expression in response to their population size by sensing the level of acyl-homoserine lactone signal molecules which they produce and liberate to the environment. We have developed an assay for these signals that couples separation by thin-layer chromatography with detection using Agrobacterium tumefaciens harboring lacZ fused to a gene that is regulated by autoinduction. With the exception of N-butanoyl-l-homoserine lactone, the reporter detected acyl-homoserine lactones with 3-oxo-, 3-hydroxy-, and 3-unsubstituted side chains of all lengths tested. The intensity of the response was proportional to the amount of the signal molecule chromatographed. Each of the 3-oxo- and the 3-unsubstituted derivatives migrated with a unique mobility. Using the assay, we showed that some bacteria produce as many as five detectable signal molecules. Structures could be assigned tentatively on the basis of mobility and spot shape. The dominant species produced by Pseudomonas syringae pv. tabaci chromatographed with the properties of N-(3-oxohexanoyl)-l-homoserine lactone, a structure that was confirmed by mass spectrometry. An isolate of Pseudomonas fluorescens produced five detectable species, three of which had novel chromatographic properties. These were identified as the 3-hydroxy- forms of N-hexanoyl-, N-octanoyl-, and N-decanoyl-l-homoserine lactone. The assay can be used to screen cultures of bacteria for acyl-homoserine lactones, for quantifying the amounts of these molecules produced, and as an analytical and preparative aid in determining the structures of these signal molecules. PMID:9177164

  14. Isotope separation

    International Nuclear Information System (INIS)

    Rosevear, A.; Sims, H.E.

    1985-01-01

    sup(195m)Au for medical usage is separated from sup(195m)Hg in a solution containing ions of sup(195m)Hg by contacting the solution with an adsorbing agent to adsorb 195 Hgsup(H) thereon, followed by selective elution of sup(195m)Au generated by radioactive decay of the sup(195m)Hg. The adsorbing agent comprises a composite material in the form of an inert porous inorganic substrate (e.g. Kieselguhr),the pores of which are occupied by a hydrogel of a polysaccharide (e.g. agarose) carrying terminal thiol groups for binding Hgsup(H) ions. (author)

  15. Isotope separation

    International Nuclear Information System (INIS)

    Coleman, J.H.; Marks, T.J.

    1981-01-01

    A process for separating uranium isotopes is described which includes: preparing a volatile compound U-T, in which U is a mixture of uranium isotopes and T is a chemical moiety containing at least one organic or deuterated borohydride group, and which exhibits for at least one isotopic species thereof a fundamental, overtone or combination vibrational absorption excitation energy level at a frequency between 900 and 1100 cm -1 ; and irradiating the compound in the vapour phase with energy emitted by a radiation source at a frequency between 900 and 1100 cm -1 (e.g. a CO 2 laser). (author)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    Makhaeva, G.F.; Suvorov, N.N.; Ginodman, L.N.; Antonov, V.K.; AN SSSR, Moscow. Inst. Bioorganicheskoj Khimii)

    1977-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Qian Cai

    Full Text Available 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.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.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.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.

  19. Identification of unusual phospholipid fatty acyl compositions of Acanthamoeba castellanii.

    Science.gov (United States)

    Palusinska-Szysz, Marta; Kania, Magdalena; Turska-Szewczuk, Anna; Danikiewicz, Witold; Russa, Ryszard; Fuchs, Beate

    2014-01-01

    Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL). The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0), octadecenoyl (18∶1 Δ9) and hexadecanoyl (16∶0). However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE), phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24) and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of these

  20. Identification of unusual phospholipid fatty acyl compositions of Acanthamoeba castellanii.

    Directory of Open Access Journals (Sweden)

    Marta Palusinska-Szysz

    Full Text Available Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL. The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0, octadecenoyl (18∶1 Δ9 and hexadecanoyl (16∶0. However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE, phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24 and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of

  1. Acyl-lupeol esters from Parahancornia amapa (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Carvalho Mário G. de

    2001-01-01

    Full Text Available From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly ¹H and 13C (HBBD and DEPT NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by MS-GC analysis.

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

    Science.gov (United States)

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

    2015-07-07

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

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

    NARCIS (Netherlands)

    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 this

  4. Physicochemical Parameters Affecting the Electrospray Ionization Efficiency of Amino Acids after Acylation.

    Science.gov (United States)

    Hermans, Jos; Ongay, Sara; Markov, Vadym; Bischoff, Rainer

    2017-09-05

    Electrospray ionization (ESI) is widely used in liquid chromatography coupled to mass spectrometry (LC-MS) for the analysis of biomolecules. However, the ESI process is still not completely understood, and it is often a matter of trial and error to enhance ESI efficiency and, hence, the response of a given set of compounds. In this work we performed a systematic study of the ESI response of 14 amino acids that were acylated with organic acid anhydrides of increasing chain length and with poly(ethylene glycol) (PEG) changing certain physicochemical properties in a predictable manner. By comparing the ESI response of 70 derivatives, we found that there was a strong correlation between the calculated molecular volume and the ESI response, while correlation with hydrophobicity (log P values), pK a , and the inverse calculated surface tension was significantly lower although still present, especially for individual derivatized amino acids with increasing acyl chain lengths. Acylation with PEG containing five ethylene glycol units led to the largest gain in ESI response. This response was maximal independent of the calculated physicochemical properties or the type of amino acid. Since no actual physicochemical data is available for most derivatized compounds, the responses were also used as input for a quantitative structure-property relationship (QSPR) model to find the best physicochemical descriptors relating to the ESI response from molecular structures using the amino acids and their derivatives as a reference set. A topological descriptor related to molecular size (SPAN) was isolated next to a descriptor related to the atomic composition and structural groups (BIC0). The validity of the model was checked with a test set of 43 additional compounds that were unrelated to amino acids. While prediction was generally good (R 2 > 0.9), compounds containing halogen atoms or nitro groups gave a lower predicted ESI response.

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

    DEFF Research Database (Denmark)

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

    1994-01-01

    The dissociation constants for octanoyl-CoA, dodecanoyl-CoA and hexadecanoyl-CoA binding to acyl-CoA-binding protein (ACBP) were determined by using titration microcalorimetry. The KD values obtained, (0.24 +/- 0.02) x 10(-6) M, (0.65 +/- 0.2) x 10(-8) M and (0.45 +/- 0.2) x 10(-13) M respectivel...

  6. Experimental and theoretical rearrangement of N-acyl-2, 2 ...

    Indian Academy of Sciences (India)

    The acid isomerization of N-acyl-2,2-dimethylaziridines 1 in concentrated sulfuric acid at room temperature leads to oxazolines 2 but the neutral hydrolysis of 1 in pure water at room temperature leads to amidoalcohols 3. However, the use of aqueous solutions of H2SO4 at different concentrations at room temperature leads ...

  7. Dietary fatty acids alter mitochondrial phospholipid fatty acyl ...

    African Journals Online (AJOL)

    Dr. J. T. Ekanem

    type and relative amount of fatty acids that make up the membrane. Naturally, the phospholipid fatty acyl profiles of biological membranes vary dramatically across species2,3. For instance, the phospholpid fatty acid profiles of cellular membranes in yeasts are different from those in flies and those of mouse are different from ...

  8. Acyl-meldrum's acid in regiospecific synthesis of isotopjcally ...

    African Journals Online (AJOL)

    Acyl-meldrum's acid in regiospecific synthesis of isotopjcally labelled compounds for polyketide biosynthetic studies. Isaiah o. Ndiege, James Staunton. Abstract. Bull. Chem. Soc. Ethiop. 1995, 9(1), 43-49. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  9. Imaging N-acyl homoserine lactone quorum sensing in vivo

    DEFF Research Database (Denmark)

    Hultqvist, Louise Dahl; Alhede, Maria; Jakobsen, Tim Holm

    2018-01-01

    In order to study N-acyl homoserine lactone (AHL)-based quorum sensing in vivo, we present a protocol using an Escherichia coli strain equipped with a luxR-based monitor system, which in the presence of exogenous AHL molecules expresses a green fluorescent protein (GFP). Lungs from mice challenged...

  10. Imaging N-acyl homoserine lactone quorum sensing in vivo

    DEFF Research Database (Denmark)

    Christensen, Louise Dahl; van Gennip, Maria; Jakobsen, Tim Holm

    2011-01-01

    In order to study N-acyl homoserine lactone (AHL)-based quorum sensing in vivo, we present a protocol using an Escherichia coli strain equipped with a luxR-based monitor system, which in the presence of exogenous AHL molecules expresses a green fluorescent protein (GFP). Lungs from mice challenged...

  11. Crystal Structure of Malonyl CoA-Acyl Carrier Protein Transacylase from Xanthomanous oryzae pv. oryzae and Its Proposed Binding with ACP

    Science.gov (United States)

    Natarajan, Sampath; Kim, Jin-Kwang; Jung, Tae-Kyun; Doan, Thanh Thi Ngoc; Ngo, Ho-Phuong-Thuy; Hong, Myoung-Ki; Kim, Seunghwan; Tan, Viet Pham; Ahn, Seok Joon; Lee, Sang Hee; Han, Yesun; Ahn, Yeh-Jin; Kang, Lin-Woo

    2012-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) is a plant bacterial pathogen that causes bacterial blight (BB) disease, resulting in serious production losses of rice. The crystal structure of malonyl CoA-acyl carrier protein transacylase (XoMCAT), encoded by the gene fabD (Xoo0880) from Xoo, was determined at 2.3 Å resolution in complex with N-cyclohexyl-2-aminoethansulfonic acid. Malonyl CoA-acyl carrier protein transacylase transfers malonyl group from malonyl CoA to acyl carrier protein (ACP). The transacylation step is essential in fatty acid synthesis. Based on the rationale, XoMCAT has been considered as a target for antibacterial agents against BB. Protein-protein interaction between XoMCAT and ACP was also extensively investigated using computational docking, and the proposed model revealed that ACP bound to the cleft between two XoMCAT subdomains. PMID:22134719

  12. Sequential one-pot synthesis of imidazoles and 2H-imidazolones from β-ketoamines, acylating agents and ammonium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Jalani, Hitesh B.; Venkateswararao, Edda; Manickam, Manoj; Jung, Sang Hun [College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon (Korea, Republic of)

    2016-12-15

    An efficient, practical, straight forward, and transition metal-free three-component synthesis of diversely substituted imidazoles and 2H-imidazolones from β-ketoamines, acylating agents, and ammonium acetate has been described herein. This approach involves [3+1+1] cyclization through consecutive formation of three C–N bonds as a sequence of initial amidation of β-ketoamines with acylating agent, β-iminoketoamide formation with ammonia, and acid catalyzed concomitant cyclodehydration to afford the imidazoles and 2H-imidazolones. This methodology has advantages such as single flask operation, readily available starting materials, mild conditions, broad functional groups tolerance, and simple work-up procedure.

  13. Synthesis and Evaluation of new Polyfunctional Molecules for Group Actinide Extraction; Synthese et evaluation de Nouvelles Molecules Polyfonctionnelles pour la Separation Groupee des Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Marie, C.

    2009-10-15

    The aim of this project is to design new extracting molecules for spent nuclear fuel reprocessing. In order to minimize the long-term residual radiotoxicity of the waste, the GANEX process is an option based on homogeneous recycling of actinides. All actinides (U, Np, Pu, Am, Cm), present in a highly acidic aqueous solution, would be extracted together and separated from fission products (especially from lanthanides) using liquid-liquid extraction. In this context, twenty new bi-topic ligands constituted of a nitrogen poly-aromatic unit functionalized by amide groups were synthesized. Liquid-liquid extraction tests with these ligands dissolved alone in the organic phase show that N, N, N', N'-tetra-alkyl-6, 6''(2, 2':6', 2''-terpyridine)-diamides are able to selectively extract actinides at different oxidation states (Np(V et VI), U(VI), Pu(IV), Am(III), Cm(III)) from an aqueous solution 3M HNO{sub 3}. Nevertheless, actinides(III) are poorly extracted. According to crystallographic structures of complexes with Nd(III) and U(VI) determined by X-rays diffraction, these ligands are penta-dentate. In solution (methanol), complexes stoichiometries (1:1) of Nd(III), U(VI) and Pu(IV) were determined by electro-spray ionization mass spectrometry. Stability constants, evaluated by UV-visible spectrophotometry in MeOH/H{sub 2}O solutions, confirm the selectivity of ligands toward actinides(III) with respect to lanthanides(III). Associate to nuclear magnetic resonance experiments and DFT calculations (Density Functional Theory), a better knowledge of their coordination mode was achieved. (author)

  14. The impact of sugar and fatty acid on the bioactivity of N-fatty acyl-L ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 6. The impact of sugar and fatty acid on the bioactivity of N-fatty acyl-L-tyrosine aglycone. SRIKANTH VUDHGIRI R B N PRASAD Y POORNACHANDRA C GANESH KUMAR E ANJANEYULU K SIRISHA RAM CHANDRA REDDY JALA. Regular Aricle ...

  15. Unusual acylation of chloramphenicol in Lysobacter enzymogenes, a biocontrol agent with intrinsic resistance to multiple antibiotics.

    Science.gov (United States)

    Zhang, Wei; Huffman, Justin; Li, Shengying; Shen, Yuemao; Du, Liangcheng

    2017-07-04

    The environmental gliding bacteria Lysobacter are emerging as a new group of biocontrol agents due to their prolific production of lytic enzymes and potent antibiotic natural products. These bacteria are intrinsically resistant to many antibiotics, but the mechanisms behind the antibiotic resistance have not been investigated. Previously, we have used chloramphenicol acetyltransferase gene (cat) as a selection marker in genetic manipulation of natural product biosynthetic genes in Lysobacter, because chloramphenicol is one of the two common antibiotics that Lysobacter are susceptible to. Here, we found L. enzymogenes, the most studied species of this genus, could still grow in the presence of a low concentration of chloramphenicol. Three chloramphenicol derivatives (1-3) with an unusual acylation pattern were identified in a cat-containing mutant of L. enzymogenes and in the wild type. The compounds included chloramphenicol 3'-isobutyrate (1), a new compound chloramphenicol 1'-isobutyrate (2), and a rare chloramphenicol 3'-isovalerate (3). Furthermore, a mutation of a global regulator gene (clp) or a Gcn5-related N-acetyltransferase (GNAT) gene in L. enzymogenes led to nearly no growth in media containing chloramphenicol, whereas a complementation of clp restored the chloramphenicol acylation as well as antibiotic HSAF production in the clp mutant. The results indicated that L. enzymogenes contains a pool of unusual acyl donors for enzymatic modification of chloramphenicol that confers the resistance, which may involve the Clp-GNAT regulatory system. Because Lysobacter are ubiquitous inhabitants of soil and water, the finding may have important implications in understanding microbial competitions and bioactive natural product regulation.

  16. Disruption of the Acyl-CoA binding protein gene delays hepatic adaptation to metabolic changes at weaning

    DEFF Research Database (Denmark)

    Neess, Ditte; Marcher, Ann-Britt; Bloksgaard, Maria

    The acyl-CoA binding protein/diazepam binding inhibitor (ACBP/DBI) is an evolutionary conserved intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity. ACBP is thought to act as an acyl-CoA transporter, and in vitro analyses have indicated that ACBP can transport acyl...

  17. Disruption of the acyl-coa binding protein gene delays hepatic adaptation to metabolic changes at weaning

    DEFF Research Database (Denmark)

    Neess, Ditte; Bloksgaard, Maria; Sørensen, Signe Bek

    2011-01-01

    The acyl-CoA binding protein/diazepam binding inhibitor (ACBP/DBI) is an intracellular protein that binds C14-C22 acyl-CoA esters and is thought to act as an acyl-CoA transporter. In vitro analyses have indicated that ACBP can transport acyl-CoA esters between different enzymatic systems; however...

  18. The electronic absorption spectra of some acyl azides. Molecular orbital treatment

    Science.gov (United States)

    Abu-Eittah, Rafie H.; Mohamed, Adel A.; Farag, A. M.; Al Omar, Ahmed M.

    2008-06-01

    The electronic absorption spectra of benzoyl azide and its derivatives: p-methyl, p-methoxy, p-chloro and p-nitrobenzoyl azide were investigated in different solvents. The observed spectra differ basically from the electronic spectra of aryl azides or alkyl azides. Four intense π-π * transitions were observed in the accessible UV region of the spectrum of each of the studied compounds. The contribution of charge transfer configurations to the observed transitions is rather weak. Shift of band maximum with solvent polarity is minute. On the other hand, band intensity is highly dependent on the solvent used. The observed transitions are delocalized rather than localized ones as in the case with aryl and alkyl azides. The attachment of the C dbnd O group to the azide group in acyl azides has a significant effect on the electronic structure of the molecule. The arrangements as well as energies of the molecular orbitals are different in acyl azides from those in aryl azides. The first electronic transition in phenyl azide is at 276 nm, whereas that of bezoyle azide is at 251 nm. Ab initio molecular orbital calculations using both RHF/6-311G* and B3LYP/6-31+G * levels were carried out on the ground states of the studied compounds. The wave functions of the excited states were calculated using the CIS and the AM1-CI procedures.

  19. Investigation of some characteristics of polyhydroxy milkweed triglycerides and their acylated derivatives in relation to lubricity.

    Science.gov (United States)

    Harry-O'kuru, Rogers E; Biresaw, Girma; Cermak, Steven C; Gordon, Sherald H; Vermillion, Karl

    2011-05-11

    Most industrial lubricants are derived from nonrenewable petroleum-based sources. As useful as these lubricants are, their unintended consequences are the pollution of the Earth's environment as a result of the slow degradation of the spent materials. Native seed oils, on the other hand, are renewable and are also biodegradable in the environment, but these oils often suffer a drawback in having lower thermal stability and a shorter shelf life because of the intrinsic -C═C- unsaturation in their structures. This drawback can be overcome, yet the inherent biodegradative property retained, by appropriate derivatization of the oil. Pursuant to this, this study investigated derivatized polyhydroxy milkweed oil to assess its suitability as lubricant. The milkweed plant is a member of the Asclepiadaceae, a family with many genera including the common milkweeds, Asclepias syriaca L., Asclepias speciosa L., Asclepias tuberosa L., etc. The seeds of these species contain mainly C-18 triglycerides that are highly unsaturated, 92%. The olefinic character of this oil has been chemically modified by generating polyhydroxy triglycerides (HMWO) that show high viscosity and excellent moisturizing characteristics. In this work, HMWO have been chemically modified by esterifying their hydroxyl groups with acyl groups of various chain lengths (C2-C5). The results of investigation into the effect of the acyl derivatives' chemical structure on kinematic and dynamic viscosity, oxidation stability, cold-flow (pour point, cloud point) properties, coefficient of friction, wear, and elastohydrodynamic film thickness are discussed.

  20. Development and modification of glass membranes for aggressive gas separations

    Energy Technology Data Exchange (ETDEWEB)

    Lindbraaten, Arne

    2004-07-01

    Chlorine as a chemical is widespread in industry and found in a great variety of processes ranging from water purification to plastic production. In this thesis, a magnesium production factory was chosen as an example because it involved both chlorine - air separation and hydrogen -hydrogen chloride separation. Previously, various types of membrane materials have been tested out for their applicability in the chosen process. The materials previously tested either lacked sufficient membrane performance or sufficient membrane stability. As an attempt to improve both the membrane performance and stability, glass membranes are used in this thesis. Glass membranes are prepared from a borosilicate glass, via a phase separation followed by an acid leaching route. By choosing the appropriate phase separation temperature and acid to glass ratio, the membrane can be produced with an average pore diameter of 2 nm (or 4 nm). However, the 2 nm average pore size is still too large to separate gases with separation selectivities beyond the selectivities predicted from Knudsen diffusion theory. If the pores are narrowed, the selectivity may be raised while the flux hopefully is maintained. The narrowing of the pores was done by a silane coupling to the surface OH-groups on the glass. The silane coupling agent is of the dimethyl-acyl-chlorosilane type, where the length of the acyl chain varies from 1 carbon up to 18 carbons. Glass fibres are also tested in this work, which are produced without phase separation and their average pore size is smaller than the surface-modified glasses. To be able to compare the performance of the various membranes, performance measurements are performed and these measurements are evaluated by the separation power (product of the selectivity and the permeability of the fastest permeating compound). Because of the harsh chlorine or hydrogen chloride environment, to which the membranes are exposed in this work, the membrane stability is at least as

  1. ALKYL SUBSTITUENT EFFECTS ON THE NEUTRAL HYDROLYSIS OF 1-ACYL-(3-SUBSTITUTED)-1,2,4-TRIAZOLES IN HIGHLY AQUEOUS REACTION MEDIA - THE IMPORTANCE OF SOLVATION

    NARCIS (Netherlands)

    BLOKZIJL, W; BLANDAMER, MJ; ENGBERTS, JBFN

    1991-01-01

    The importance of solvation in determining substituent effects of alkyl groups has been assessed in a quantitative study of the medium effects of ethanol and 1-propanol on the neutral hydrolysis of 18 1-acyl-(3-substituted)-1,2,4-triazoles in highly aqueous solutions. The dependence of the

  2. Quantitation of acyl migration during lipase-catalyzed acidolysis, and of the regioisomers of structured triacylglycerols formed

    DEFF Research Database (Denmark)

    Mu, Huiling; Kurvinen, J.P.; Kallio, H.

    2001-01-01

    degradation, and ranged from 39.0 to 48.7% and 0.6 to 9.3%, respectively. Quantitation of triacylglycerol molecular species was performed by ammonia negative ion chemical ionization (NICI) mass spectrometry (MS). The proportion of ACN (acyl carbon number) 34 species that contained one C-18 fatty acid and two...... C-8:0, in samples analyzed, varied from 12.5 to 23.2%. The selected regioisomers MLM and MML within the ACN 34 species group were quantified by NICI tandem MS (MS/MS) and were in the range of 97.1 to 98.4% and 1.6 to 2.9%, respectively. There was no correlation between the level of acyl migration...

  3. Isotope separation

    International Nuclear Information System (INIS)

    Ravoire, Jean

    1978-11-01

    Separation of isotopes is treated in a general way, with special reference to the production of enriched uranium. Uses of separated isotopes are presented quickly. Then basic definitions and theoretical concepts are explained: isotopic effects, non statistical and statistical processes, reversible and irreversible processes, separation factor, enrichment, cascades, isotopic separative work, thermodynamics. Afterwards the main processes and productions are reviewed. Finally the economical and industrial aspects of uranium enrichment are resumed [fr

  4. Lipase-catalyzed biodiesel synthesis with different acyl acceptors

    Directory of Open Access Journals (Sweden)

    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.

  5. Crystallization of the acyl-CoA thioesterase TesB from Yersinia pestis

    International Nuclear Information System (INIS)

    Swarbrick, Crystall M. D.; Patterson, Edward I.; Forwood, Jade K.

    2013-01-01

    The expression, purification, crystallization and diffraction of the acyl-CoA thioesterase TesB from Y. pestis are reported. X-ray crystallographic diffraction data to 2.0 Å resolution were collected at the Australian Synchrotron. Yersinia pestis is a highly virulent human pathogen and is the causative agent of bubonic plague. Spread through the bite of infected fleas, plague epidemics have marked important events in history, including the Justinian plague (6th century), the Black Death (14th century) which decimated nearly one quarter of the European population, and more recently the Orientalis plague (1894). To date, deaths are still being reported and, without treatment, the disease kills most people within 4 days. One of the thioesterases from Y. pestis, TesB, is a broad-range acyl-CoA thioesterase and is highly conserved within prokaryotes and throughout evolution, sharing sequence similarity with the HIV Nef binding protein ACOT8. Here the expression, purification, crystallization and diffraction of TesB are reported. TesB has been recombinantly expressed and crystallized using the vapour-diffusion hanging-drop technique at pH 7.0 and 290 K. After optimization, crystals diffracted to 2.0 Å resolution at the Australian Synchrotron and belong to the space group P12 1 1 (a = 73.55, b = 170.82, c = 101.98 Å), with eight molecules likely to be present in the asymmetric unit

  6. Silica gel-Supported Palladium Catalyst for the Acyl Sonogashira Reaction

    International Nuclear Information System (INIS)

    Hossain, Shahin; Park, Jihoon; Park, Minkyu; Jin, Myungjong

    2013-01-01

    We have demonstrated an efficient and eco-friendly procedure for the synthesis of ynones using silica supported thiol-palladium complex as a recyclable catalyst under copper free mild reaction conditions. The material was synthesized by post grafting of 3-mercaptopropyltrimethoxysilane on amorphous silica and subsequently Pd(II) attached onto thiol groups. This synthetic method has notable advantages because it involves easily available, less costly and produces an easily recyclable catalyst in high yields of the products. The mild reaction conditions encouraged us to further extension for the development of novel multicomponent reactions. Thus we have explained the three component synthesis of pyrazoles in one-pot fashion with good yields. Specifically, this simple procedure for the ynone synthesis and this approach to synthesize N-containing heterocycles may be valuable tool in future. The acyl Sonogashira reaction between acyl chlorides and terminal alkynes is one of the most useful method for the preparation of ynones which are important intermediates to prepare versatile pharmaceutically and biologically active heterocyclic compounds such as pyrroles, pyrazoles, furans, furanones, isoxazoles, pyrimidines, quinolines, indolizidinones

  7. Glycosyltransferases from Oat (Avena) Implicated in the Acylation of Avenacins*

    Science.gov (United States)

    Owatworakit, Amorn; Townsend, Belinda; Louveau, Thomas; Jenner, Helen; Rejzek, Martin; Hughes, Richard K.; Saalbach, Gerhard; Qi, Xiaoquan; Bakht, Saleha; Roy, Abhijeet Deb; Mugford, Sam T.; Goss, Rebecca J. M.; Field, Robert A.; Osbourn, Anne

    2013-01-01

    Plants produce a huge array of specialized metabolites that have important functions in defense against biotic and abiotic stresses. Many of these compounds are glycosylated by family 1 glycosyltransferases (GTs). Oats (Avena spp.) make root-derived antimicrobial triterpenes (avenacins) that provide protection against soil-borne diseases. The ability to synthesize avenacins has evolved since the divergence of oats from other cereals and grasses. The major avenacin, A-1, is acylated with N-methylanthranilic acid. Previously, we have cloned and characterized three genes for avenacin synthesis (for the triterpene synthase SAD1, a triterpene-modifying cytochrome P450 SAD2, and the serine carboxypeptidase-like acyl transferase SAD7), which form part of a biosynthetic gene cluster. Here, we identify a fourth member of this gene cluster encoding a GT belonging to clade L of family 1 (UGT74H5), and show that this enzyme is an N-methylanthranilic acid O-glucosyltransferase implicated in the synthesis of avenacin A-1. Two other closely related family 1 GTs (UGT74H6 and UGT74H7) are also expressed in oat roots. One of these (UGT74H6) is able to glucosylate both N-methylanthranilic acid and benzoic acid, whereas the function of the other (UGT74H7) remains unknown. Our investigations indicate that UGT74H5 is likely to be key for the generation of the activated acyl donor used by SAD7 in the synthesis of the major avenacin, A-1, whereas UGT74H6 may contribute to the synthesis of other forms of avenacin that are acylated with benzoic acid. PMID:23258535

  8. Glycosyltransferases from oat (Avena) implicated in the acylation of avenacins.

    Science.gov (United States)

    Owatworakit, Amorn; Townsend, Belinda; Louveau, Thomas; Jenner, Helen; Rejzek, Martin; Hughes, Richard K; Saalbach, Gerhard; Qi, Xiaoquan; Bakht, Saleha; Roy, Abhijeet Deb; Mugford, Sam T; Goss, Rebecca J M; Field, Robert A; Osbourn, Anne

    2013-02-08

    Plants produce a huge array of specialized metabolites that have important functions in defense against biotic and abiotic stresses. Many of these compounds are glycosylated by family 1 glycosyltransferases (GTs). Oats (Avena spp.) make root-derived antimicrobial triterpenes (avenacins) that provide protection against soil-borne diseases. The ability to synthesize avenacins has evolved since the divergence of oats from other cereals and grasses. The major avenacin, A-1, is acylated with N-methylanthranilic acid. Previously, we have cloned and characterized three genes for avenacin synthesis (for the triterpene synthase SAD1, a triterpene-modifying cytochrome P450 SAD2, and the serine carboxypeptidase-like acyl transferase SAD7), which form part of a biosynthetic gene cluster. Here, we identify a fourth member of this gene cluster encoding a GT belonging to clade L of family 1 (UGT74H5), and show that this enzyme is an N-methylanthranilic acid O-glucosyltransferase implicated in the synthesis of avenacin A-1. Two other closely related family 1 GTs (UGT74H6 and UGT74H7) are also expressed in oat roots. One of these (UGT74H6) is able to glucosylate both N-methylanthranilic acid and benzoic acid, whereas the function of the other (UGT74H7) remains unknown. Our investigations indicate that UGT74H5 is likely to be key for the generation of the activated acyl donor used by SAD7 in the synthesis of the major avenacin, A-1, whereas UGT74H6 may contribute to the synthesis of other forms of avenacin that are acylated with benzoic acid.

  9. Bioorthogonal Chemical Reporters for Monitoring Unsaturated Fatty-Acylated Proteins

    OpenAIRE

    Thinon, Emmanuelle; Percher, Avital; Hang, Howard C.

    2016-01-01

    Dietary unsaturated fatty acids, such as oleic acid, have been shown to be covalently incorporated into a small subset of proteins but the generality and diversity of this protein modification has not been studied. We synthesized unsaturated fatty acid chemical reporters and determined their protein targets in mammalian cells. The unsaturated fatty acid chemical reporters can induce the formation of lipid droplets and be incorporated site-specifically onto known fatty-acylated proteins and la...

  10. Acylated flavonoid and phenylethanoid glycosides from Marrubium velutinum.

    Science.gov (United States)

    Karioti, Anastasia; Skaltsa, Helen; Heilmann, Jörg; Sticher, Otto

    2003-09-01

    From the aerial parts of Marrubium velutinum, one acylated flavonoid glycoside, chrysoeriol 7-O-(3",6"-di-O-E-p-coumaroyl)-beta-D-glucopyranoside, and two tetrasaccharidic phenylethanoid glycosides, velutinosides I-II, have been isolated together with ten known flavonoids and seven known phenylethanoid glycosides. The structures of the isolated compounds were established by means of NMR, MS, and UV spectral analyses.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. A Comparative Analysis of Acyl-Homoserine Lactone Synthase Assays.

    Science.gov (United States)

    Shin, Daniel; Frane, Nicole D; Brecht, Ryan M; Keeler, Jesse; Nagarajan, Rajesh

    2015-12-01

    Quorum sensing is cell-to-cell communication that allows bacteria to coordinate attacks on their hosts by inducing virulent gene expression, biofilm production, and other cellular functions, including antibiotic resistance. AHL synthase enzymes synthesize N-acyl-l-homoserine lactones, commonly referred to as autoinducers, to facilitate quorum sensing in Gram-negative bacteria. Studying the synthases, however, has proven to be a difficult road. Two assays, including a radiolabeled assay and a colorimetric (DCPIP) assay are well-documented in literature to study AHL synthases. In this paper, we describe additional methods that include an HPLC-based, C-S bond cleavage and coupled assays to investigate this class of enzymes. In addition, we compare and contrast each assay for both acyl-CoA- and acyl-ACP-utilizing synthases. The expanded toolkit described in this study should facilitate mechanistic studies on quorum sensing signal synthases and expedite discovery of antivirulent compounds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

    Cooper, C.L.; Rock, C.O.

    1987-01-01

    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 32 P and [ 3 H]acetate in the absence of glycerol-3-P acyltransferase activity indicated that [ 3 H]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 [ 3 H]acetate and lipoprotein expression was induced concomitant with the addition of exogenous [ 14 C]-palmitate. [ 14 C] 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

  14. A separator

    Energy Technology Data Exchange (ETDEWEB)

    Prokopyuk, S.G.; Dyachenko, A.Ye.; Mukhametov, M.N.; Prokopov, O.I.

    1982-01-01

    A separator is proposed which contains separating slanted plates and baffle plates installed at a distance to them at an acute angle to them. To increase the effectiveness of separating a gas and liquid stream and the throughput through reducing the secondary carry away of the liquid drops and to reduce the hydraulic resistance, as well, openings are made in the plates. The horizontal projections of each opening from the lower and upper surfaces of the plate do not overlap each other.

  15. Atypical cleavage of protonated N-fatty acyl amino acids derived from aspartic acid evidenced by sequential MS3 experiments.

    Science.gov (United States)

    Boukerche, Toufik Taalibi; Alves, Sandra; Le Faouder, Pauline; Warnet, Anna; Bertrand-Michel, Justine; Bouchekara, Mohamed; Belbachir, Mohammed; Tabet, Jean-Claude

    2016-12-01

    Lipidomics calls for information on detected lipids and conjugates whose structural elucidation by mass spectrometry requires to rationalization of their gas phase dissociations toward collision-induced dissociation (CID) processes. This study focused on activated dissociations of two lipoamino acid (LAA) systems composed of N-palmitoyl acyl coupled with aspartic and glutamic acid mono ethyl esters (as LAA (*D) and LAA (*E) ). Although in MS/MS, their CID spectra show similar trends, e.g., release of water and ethanol, the [(LAA (*D/*E) +H)-C 2 H 5 OH] + product ions dissociate via distinct pathways in sequential MS 3 experiments. The formation of all the product ions is rationalized by charge-promoted cleavages often involving stepwise processes with ion isomerization into ion-dipole prior to dissociation. The latter explains the maleic anhydride or ketene neutral losses from N-palmitoyl acyl aspartate and glutamate anhydride fragment ions, respectively. Consequently, protonated palmitoyl acid amide is generated from LAA (*D), whereas LAA (*E) leads to the [*E+H-H 2 O] + anhydride. The former releases ammonia to provide acylium, which gives the C n H (2n-1) and C n H (2n-3) carbenium series. This should offer structural information, e.g., to locate either unsaturation(s) or alkyl group branching present on the various fatty acyl moieties of lipo-aspartic acid in further studies based on MS n experiments.

  16. Structural and dynamic characterization of a freestanding acyl carrier protein involved in the biosynthesis of cyclic lipopeptide antibiotics.

    Science.gov (United States)

    Paul, Subrata; Ishida, Hiroaki; Nguyen, Leonard T; Liu, Zhihong; Vogel, Hans J

    2017-05-01

    Friulimicin is a cyclic lipodecapeptide antibiotic that is produced by Actinoplanes friuliensis. Similar to the related lipopeptide drug daptomycin, the peptide skeleton of friulimicin is synthesized by a large multienzyme nonribosomal peptide synthetase (NRPS) system. The LipD protein plays a major role in the acylation reaction of friulimicin. The attachment of the fatty acid group promotes its antibiotic activity. Phylogenetic analysis reveals that LipD is most closely related to other freestanding acyl carrier proteins (ACPs), for which the genes are located near to NRPS gene clusters. Here, we report that the solution NMR structure of apo-LipD is very similar to other four-helix bundle forming ACPs from fatty acid synthase (FAS), polyketide synthase, and NRPS systems. By recording NMR dynamics data, we found that the backbone motions in holo-LipD are more restricted than in apo-LipD due to the attachment of phosphopantetheine moiety. This enhanced stability of holo-LipD was also observed in differential scanning calorimetry experiments. Furthermore, we demonstrate that, unlike several other ACPs, the folding of LipD does not depend on the presence of divalent cations, although the presence of Mg 2+ or Ca 2+ can increase the protein stability. We propose that small structural rearrangements in the tertiary structure of holo-LipD which lead to the enhanced stability are important for the cognate enzyme recognition for the acylation reaction. Our results also highlight the different surface charges of LipD and FAS-ACP from A. friuliensis that would allow the acyl-CoA ligase to interact preferentially with the LipD instead of binding to the FAS-ACP. © 2017 The Protein Society.

  17. Comparison of the effects of growth hormone on acylated ghrelin and following acute intermittent exercise in two levels of obesity

    Directory of Open Access Journals (Sweden)

    Majid Gholipour

    2013-08-01

    Full Text Available Background: The prevalence of obesity has risen enormously over the past few decad-es. Both food intake (Appetite and energy expenditure can influence body weight. Acylated ghrelin enhances appetite, and its plasma level is suppressed by growth horm-one. The present study, examines the effects of an intermittent exercise with progress-ive intensities on acylated ghrelin, appetite, and growth hormone in inactive male students with two levels of obesity.Methods: Eleven inactive males were allocated into two groups on the basis of their body mass index (BMI. Six subjects in group one, BMI= 31.18±0.92 kg/m2, and five subjects in group two, BMI= 36.94±2.25 kg/m2, ran on the treadmill with progressive intensities of 50, 60, 70 and 80% of VO2max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise (as the resting values, after each workload (during the exercise, and at 30, 60, and 120 min (during recovery.Results: Plasma acylated ghrelin concentrations and hunger ratings in two groups were decreased and remained significantly lower than resting values (P=0.008 and P=0.002 respectively at the end of the trial and there was no significant differences between groups. Growth hormone levels in two groups were increased and remained significant-ly higher than resting values (groups one P=0.012, group two P=0.005 at the end of the trial and there was no significant differences between groups. In addition, there were no significant differences between area under the curves (AUC values over total periods for acylated ghrelin, hunger ratings, and growth hormone in two groups.Conclusion: These findings indicate that individuals with two levels of obesity have the same response to the different intensities of treadmill running and two hours thereafter during recovery period, which can be considered for designing a more effective weighting loss training program.

  18. Light Microscopy Research Group (LMRG): International Test Results for Objective Lens Quality, Resolution, Spectral Accuracy and Spectral Separation for Confocal Laser Scanning Microscopes (CLSM)

    Science.gov (United States)

    Thibault, Marc; Bayles, Carol J.; Eason, Brady; Girard, Anne-Marie; Jinadasa, Tushare; Opansky, Cynthia; Schulz, Katherine; Brown, Claire M.; Cole, Richard W.

    2013-01-01

    As part of an ongoing effort to increase image reproducibility and fidelity in addition to improving cross-instrument consistency we have developed four separate instrument quality tests to augment the ones previously reported. 1) Objective lens quality 2) Resolution 3) Spectral accuracy of the wavelength information from spectral detectors 4) Spectral Separation tested the accuracy and quality of un-mixing algorithms. To ascertain the usefulness of these tests as well as to determine the current ““state”” of microscopes in use, test specimens and detailed protocols were made available worldwide free-of-charge. 55 laboratories located in 18 countries provided data. Objective lens quality: good with most issues arising from user errors or stage/focus drift, approximately 10% of lenses had aberrations. Resolution: within an average of approximately 25% of theoretical values. Spectral accuracy: excellent, even for low resolution systems. Spectral un-mixing: good, poor data collection was the main cause of low quality data.

  19. Isotope separation

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1979-01-01

    A method of isotope separation is described which involves the use of a laser photon beam to selectively induce energy level transitions of an isotope molecule containing the isotope to be separated. The use of the technique for 235 U enrichment is demonstrated. (UK)

  20. Identification of endogenous acyl amino acids based on a targeted lipidomics approach1[S

    OpenAIRE

    Tan, Bo; O'Dell, David K.; Yu, Y. William; Monn, M. Francesca; Hughes, H. Velocity; Burstein, Sumner; Walker, J. Michael

    2010-01-01

    Using a partially purified bovine brain extract, our lab identified three novel endogenous acyl amino acids in mammalian tissues. The presence of numerous amino acids in the body and their ability to form amides with several saturated and unsaturated fatty acids indicated the potential existence of a large number of heretofore unidentified acyl amino acids. Reports of several additional acyl amino acids that activate G-protein coupled receptors (e.g., N-arachidonoyl glycine, N-arachidonoyl se...

  1. A rapid and specific derivatization procedure to identify acyl-glucuronides by mass spectrometry.

    Science.gov (United States)

    Vaz, Alfin D N; Wang, Wei Wei; Bessire, Andrew J; Sharma, Raman; Hagen, Anne E

    2010-07-30

    A simple procedure is described to identify acyl-glucuronides by coupled liquid chromatography/mass spectrometry after derivatization to a hydroxamic acid with hydroxylamine. The reaction specificity obviates the need for isolation of the acyl-glucuronide from an extract. Glucuronides derived from carbamic acids, and alkyl- and aromatic amines, are inert to the derivatization reaction conditions, making the hydroxamic acid derivative a fingerprint for acyl-glucuronides. Copyright 2010 John Wiley & Sons, Ltd.

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

    DEFF Research Database (Denmark)

    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 hy...... on Caco-2 cells, indicating that acylation of sCT may represent a promising tool to increase intestinal permeability without adding oral permeation enhancers....

  3. THE SEPARATION GAME

    OpenAIRE

    TRISTAN CAZENAVE

    2006-01-01

    The separation game is different from the connection game, but has some similarities. In the game of Go, it is often useful because it helps to enclose groups and areas. An evaluation function, moves generation functions and a search algorithm for the separation game are described in this paper.

  4. Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

    Directory of Open Access Journals (Sweden)

    Tor E. Kristensen

    2015-04-01

    Full Text Available Amino acids, whether natural, semisynthetic or synthetic, are among the most important and useful chiral building blocks available for organic chemical synthesis. In principle, they can function as inexpensive, chiral and densely functionalized starting materials. On the other hand, the use of amino acid starting materials routinely necessitates protective group chemistry, and in reality, large-scale preparations of even the simplest side-chain derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4-dihydroxyphenylalanine (DOPA, many O-acyl side-chain derivatives are directly accessible via a particularly expedient and scalable method not commonly applied until recently. Direct acylation of unprotected hydroxyamino acids with acyl halides or carboxylic anhydrides under appropriately acidic reaction conditions renders possible chemoselective O-acylation, furnishing the corresponding side-chain esters directly, on multigram-scale, in a single step, and without chromatographic purification. Assuming a certain degree of stability under acidic reaction conditions, the method is also applicable for a number of related compounds, such as various amino alcohols and the thiol-functional amino acid cysteine. While the basic methodology underlying this approach has been known for decades, it has evolved through recent developments connected to amino acid-derived chiral organocatalysts to become a more widely recognized procedure for large-scale preparation of many useful side-chain derivatives of hydroxyamino acids and related compounds. Such derivatives are useful in peptide chemistry and drug development, as amino acid amphiphiles for asymmetric catalysis, and as amino acid acrylic precursors for preparation of

  5. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  6. Separated Shoulder

    Science.gov (United States)

    ... ligaments that hold your collarbone (clavicle) to your shoulder blade. In a mild separated shoulder, the ligaments might ... the ligaments that hold your collarbone to your shoulder blade. Risk factors Participating in contact sports, such as ...

  7. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1979-01-01

    Isotopic species in an isotopic mixture including a first species having a first isotope and a second species having a second isotope are separated by selectively exciting the first species in preference to the second species and then reacting the selectively excited first species with an additional preselected radiation, an electron or another chemical species so as to form a product having a mass different from the original species and separating the product from the balance of the mixture in a centrifugal separating device such as centrifuge or aerodynamic nozzle. In the centrifuge the isotopic mixture is passed into a rotor where it is irradiated through a window. Heavier and lighter components can be withdrawn. The irradiated mixture experiences a large centrifugal force and is separated in a deflection area into lighter and heavier components. (UK)

  8. Isotopic separation

    International Nuclear Information System (INIS)

    Castle, P.M.

    1979-01-01

    This invention relates to molecular and atomic isotope separation and is particularly applicable to the separation of 235 U from other uranium isotopes including 238 U. In the method described a desired isotope is separated mechanically from an atomic or molecular beam formed from an isotope mixture utilising the isotropic recoil momenta resulting from selective excitation of the desired isotope species by radiation, followed by ionization or dissociation by radiation or electron attachment. By forming a matrix of UF 6 molecules in HBr molecules so as to collapse the V 3 vibrational mode of the UF 6 molecule the 235 UF 6 molecules are selectively excited to promote reduction of UF 6 molecules containing 235 U and facilitate separation. (UK)

  9. 3-O-Acyl-epicatechins Increase Glucose Uptake Activity and GLUT4 Translocation through Activation of PI3K Signaling in Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    Manabu Ueda-Wakagi

    2015-07-01

    Full Text Available Tea catechins promote glucose uptake in skeletal muscle cells. In this study, we investigated whether the addition of an acyl group to the C-3 position of catechins to generate 3-O-acyl-catechins promoted glucose uptake in L6 myotubes. 3-O-Myristoyl-(−-epicatechin (EC-C14 and 3-O-palmitoyl-(−-epicatechin (EC-C16 promoted glucose uptake and translocation of glucose transporter (GLUT 4 in the cells. The effect of 3-O-acyl-(−-epicatechins was stronger than that of (−-epicatechin (EC, whereas neither 3-O-myristoyl-(+-catechin (C-C14 nor 3-O-palmitoyl-(+catechin (C-C16 promoted glucose uptake or GLUT4 translocation as well as (+-catechin (C. We further investigated an affinity of catechins and 3-O-acyl-catechins to the lipid bilayer membrane by using surface plasma resonance analysis. Maximum binding amounts of EC-C16 and C-C16 to the lipid bilayer clearly increased compared with that of (−-EC and (+-C, respectively. We also examined the mechanism of GLUT4 translocation and found EC-C14 and EC-C16 induced the phosphorylation of PI3K, but did not affect phosphorylation of Akt or IR. In conclusion, the addition of an acyl group to the C-3 position of (−-EC increases its affinity for the lipid bilayer membrane and promotes GLUT4 translocation through PI3K-dependent pathways in L6 myotubes.

  10. Separations chemistry

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Results of studies on the photochemistry of aqueous Pu solutions and the stability of iodine in liquid and gaseous CO 2 are reported. Progress is reported in studies on: the preparation of macroporous bodies filled with oxides and sulfides to be used as adsorbents; the beneficiation of photographic wastes; the anion exchange adsorption of transition elements from thiosulfate solutions; advanced filtration applications of energy significance; high-resolution separations; and, the examination of the separation agents, octylphenylphosphoric acid (OPPA) and trihexyl phosphate (THP)

  11. Product separator

    International Nuclear Information System (INIS)

    Welsh, R.A.; Deurbrouck, A.W.

    1976-01-01

    A description is given of a secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted, nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present

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

    DEFF Research Database (Denmark)

    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...

  13. Phosphorylation and Acetylation of Acyl-CoA Synthetase- I

    DEFF Research Database (Denmark)

    Frahm, Jennifer L; Li, Lei O; Grevengoed, Trisha J

    2011-01-01

    Long chain acyl-CoA synthetase 1 (ACSL1) contributes 50 to 90% of total ACSL activity in liver, adipose tissue, and heart and appears to direct the use of long chain fatty acids for energy. Although the functional importance of ACSL1 is becoming clear, little is understood about its post...... and acetylated amino acids by mass spectrometry. We then compared these results to the post-translational modifications observed in vivo in liver and brown adipose tissue after mice were fasted or exposed to a cold environment. We identified universal N-terminal acetylation, 15 acetylated lysines, and 25...

  14. Medium-chain acyl-CoA dehydrogenase deficiency

    DEFF Research Database (Denmark)

    Waddell, Leigh; Wiley, Veronica; Carpenter, Kevin

    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......, plasma octanoylcarnitine when asymptomatic, and urinary acylglycines. Compound heterozygotes of c.985A > G and other mutations had intermediate levels, and those without c.985A > G, or heterozygous for that and c.199T > C had the lowest levels of these analytes. There was overlap in all values. The c.985...

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    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...

  17. A Grapevine Anthocyanin Acyltransferase, Transcriptionally Regulated by VvMYBA, Can Produce Most Acylated Anthocyanins Present in Grape Skins.

    Science.gov (United States)

    Rinaldo, Amy R; Cavallini, Erika; Jia, Yong; Moss, Sarah M A; McDavid, Debra A J; Hooper, Lauren C; Robinson, Simon P; Tornielli, Giovanni B; Zenoni, Sara; Ford, Christopher M; Boss, Paul K; Walker, Amanda R

    2015-11-01

    Anthocyanins are flavonoid compounds responsible for red/purple colors in the leaves, fruit, and flowers of many plant species. They are produced through a multistep pathway that is controlled by MYB transcription factors. VvMYBA1 and VvMYBA2 activate anthocyanin biosynthesis in grapevine (Vitis vinifera) and are nonfunctional in white grapevine cultivars. In this study, transgenic grapevines with altered VvMYBA gene expression were developed, and transcript analysis was carried out on berries using a microarray technique. The results showed that VvMYBA is a positive regulator of the later stages of anthocyanin synthesis, modification, and transport in cv Shiraz. One up-regulated gene, ANTHOCYANIN 3-O-GLUCOSIDE-6″-O-ACYLTRANSFERASE (Vv3AT), encodes a BAHD acyltransferase protein (named after the first letter of the first four characterized proteins: BEAT [for acetyl CoA:benzylalcohol acetyltransferase], AHCT [for anthocyanin O-hydroxycinnamoyltransferase], HCBT [for anthranilate N-hydroxycinnamoyl/benzoyltransferase], and DAT [for deacetylvindoline 4-O-acetyltransferase]), belonging to a clade separate from most anthocyanin acyltransferases. Functional studies (in planta and in vitro) show that Vv3AT has a broad anthocyanin substrate specificity and can also utilize both aliphatic and aromatic acyl donors, a novel activity for this enzyme family found in nature. In cv Pinot Noir, a red-berried grapevine mutant lacking acylated anthocyanins, Vv3AT contains a nonsense mutation encoding a truncated protein that lacks two motifs required for BAHD protein activity. Promoter activation assays confirm that Vv3AT transcription is activated by VvMYBA1, which adds to the current understanding of the regulation of the BAHD gene family. The flexibility of Vv3AT to use both classes of acyl donors will be useful in the engineering of anthocyanins in planta or in vitro. © 2015 American Society of Plant Biologists. All Rights Reserved.

  18. A Grapevine Anthocyanin Acyltransferase, Transcriptionally Regulated by VvMYBA, Can Produce Most Acylated Anthocyanins Present in Grape Skins1

    Science.gov (United States)

    Rinaldo, Amy R.; Cavallini, Erika; Jia, Yong; Moss, Sarah M.A.; McDavid, Debra A.J.; Hooper, Lauren C.; Robinson, Simon P.; Tornielli, Giovanni B.; Zenoni, Sara; Ford, Christopher M.; Boss, Paul K.; Walker, Amanda R.

    2015-01-01

    Anthocyanins are flavonoid compounds responsible for red/purple colors in the leaves, fruit, and flowers of many plant species. They are produced through a multistep pathway that is controlled by MYB transcription factors. VvMYBA1 and VvMYBA2 activate anthocyanin biosynthesis in grapevine (Vitis vinifera) and are nonfunctional in white grapevine cultivars. In this study, transgenic grapevines with altered VvMYBA gene expression were developed, and transcript analysis was carried out on berries using a microarray technique. The results showed that VvMYBA is a positive regulator of the later stages of anthocyanin synthesis, modification, and transport in cv Shiraz. One up-regulated gene, ANTHOCYANIN 3-O-GLUCOSIDE-6″-O-ACYLTRANSFERASE (Vv3AT), encodes a BAHD acyltransferase protein (named after the first letter of the first four characterized proteins: BEAT [for acetyl CoA:benzylalcohol acetyltransferase], AHCT [for anthocyanin O-hydroxycinnamoyltransferase], HCBT [for anthranilate N-hydroxycinnamoyl/benzoyltransferase], and DAT [for deacetylvindoline 4-O-acetyltransferase]), belonging to a clade separate from most anthocyanin acyltransferases. Functional studies (in planta and in vitro) show that Vv3AT has a broad anthocyanin substrate specificity and can also utilize both aliphatic and aromatic acyl donors, a novel activity for this enzyme family found in nature. In cv Pinot Noir, a red-berried grapevine mutant lacking acylated anthocyanins, Vv3AT contains a nonsense mutation encoding a truncated protein that lacks two motifs required for BAHD protein activity. Promoter activation assays confirm that Vv3AT transcription is activated by VvMYBA1, which adds to the current understanding of the regulation of the BAHD gene family. The flexibility of Vv3AT to use both classes of acyl donors will be useful in the engineering of anthocyanins in planta or in vitro. PMID:26395841

  19. Intracellular long-chain acyl CoAs activate TRPV1 channels.

    Directory of Open Access Journals (Sweden)

    Yi Yu

    Full Text Available TRPV1 channels are an important class of membrane proteins that play an integral role in the regulation of intracellular cations such as calcium in many different tissue types. The anionic phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2 is a known positive modulator of TRPV1 channels and the negatively charged phosphate groups interact with several basic amino acid residues in the proximal C-terminal TRP domain of the TRPV1 channel. We and other groups have shown that physiological sub-micromolar levels of long-chain acyl CoAs (LC-CoAs, another ubiquitous anionic lipid, can also act as positive modulators of ion channels and exchangers. Therefore, we investigated whether TRPV1 channel activity is similarly regulated by LC-CoAs. Our results show that LC-CoAs are potent activators of the TRPV1 channel and interact with the same PIP2-binding residues in TRPV1. In contrast to PIP2, LC-CoA modulation of TRPV1 is independent of Ca2+i, acting in an acyl side-chain saturation and chain-length dependent manner. Elevation of LC-CoAs in intact Jurkat T-cells leads to significant increases in agonist-induced Ca2+i levels. Our novel findings indicate that LC-CoAs represent a new fundamental mechanism for regulation of TRPV1 channel activity that may play a role in diverse cell types under physiological and pathophysiological conditions that alter fatty acid transport and metabolism such as obesity and diabetes.

  20. Thermodynamics of micellization of nonionic saccharide-based N-acyl-N-alkylaldosylamine and N-acyl-N-alkylamino-1-deoxyalditol surfactants

    NARCIS (Netherlands)

    Pestman, J.M.; Kevelam, J.; Blandamer, M.J.; Doren, H.A. van; Kellogg, R.M.; Engberts, J.B.F.N.

    1999-01-01

    Eight homologous series of nonionic carbohydrate-derived surfactants in which the alkyl chains are linked through N-acylated amine bonds were synthesized, and their critical micelle concentrations (cmc's) and standard enthalpies of micellization were determined using titration microcalorimetry.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    -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...

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Besides serving as essential substrates for beta-oxidation and synthesis of triacylglycerols and more complex lipids like sphingolipids and sterol esters, long-chain fatty acyl-CoA esters are increasingly being recognized as important regulators of enzyme activities and gene transcription. Acyl-C...

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

    DEFF Research Database (Denmark)

    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...

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    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...

  6. Acylation of aromatic alcohols and phenols over InCl 3 ...

    Indian Academy of Sciences (India)

    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.

  7. Acylated Ghrelin Level Response to Daily Step in the Post-Menopause Active and Sedentary Elderly Women

    Directory of Open Access Journals (Sweden)

    Farzad Nazem

    2014-07-01

    Full Text Available Objectives: Plasmatic total ghrelin levels (ie, acylate & unacylated isoformes are changeable during malnutrition, starvation regime, exercise bouts, obesity and hyperglycemia conditions. Studies have reported increases, decreases or no change in total ghrelin concentrations as a resultsresults of exercise. WalkingSince walking is used as a movement current pattern with a different lifestyle conditions, especially in several social jobs activities of daily livings of the middle-aged and elderly, the aim of the present study is to evaluate whether therelationship betweenthe number of step per day steps per day andwith acylated ghrelin of menopausal women is related to different life styles.as well, the effects of physical activity volume on this peptide hormone. Methods & Materials: Daily step volumes voluntarily were measured in the health postmenopausal women (n=40 by the electronic pedometer. Subjects (aged 55.9±4.6 divided by as active group (AG=20 and sedentary group (SG=20. Results: Daily step average in the AG (8022±2659 step/day significantly was higher than SG (3450±913 step/day (P<0.001. Acylated ghrelin and Insulin concentrations were markedly not different in AG (195.4±131 pg/ml, 9.2±3.03 μU/ml respectively and SG (165.4±73 pg/ml, 11.5±4.7 μU/ml respectively as well, step per day were not associated with these hormones. There was a significant difference in body composition variables (BMI, %BF, WHR among 2 groups and significant inverse correlations were found between activity and body composition variables in women. Conclusion: According to the results, it is recommended that trainers, organizations and institutions that deal with the elderly, use the cycling and walking exercises, especially walking and jogging to reduce the risk of further problem in these people.

  8. Isotope separation

    International Nuclear Information System (INIS)

    Bartlett, R.J.; Morrey, J.R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated

  9. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.

    1981-01-01

    Method and apparatus for separating isotopes in an isotopic mixture of atoms or molecules by increasing the mass differential among isotopic species. The mixture containing a particular isotope is selectively irradiated so as to selectively excite the isotope. This preferentially excited species is then reacted rapidly with an additional preselected radiation, an electron or another chemical species so as to form a product containing the specific isotope, but having a mass different than the original species initially containing the particular isotope. The product and the remaining balance of the mixture is then caused to flow through a device which separates the product from the mixture based upon the increased mass differential

  10. Acyl coenzyme A carboxylase of Propionibacterium shermanii: detection and properties.

    Science.gov (United States)

    Stirling, L A; Ahmad, P M; Ahmad, F

    1981-01-01

    An acyl coenzyme A (CoA) carboxylase, which catalyzes the adenosine triphosphate-dependent fixation of CO2 into acetyl-, propionyl-, and butyryl-CoA, was detected in fractionated cell extracts of Propionibacterium shermanii. Catalytic activity was inhibited by avidin but was unaffected by avidin pretreated with excess biotin. The carboxylase levels detected were relatively small and were related to cellular growth. Maximal carboxylase activity was detected in cells grown for about 96 h. Thereafter, the activity declined rapidly. Optimal CO2 fixation occurred at pH 7.5. Other parameters of the assay system were optimized, and the apparent Km values for substrates were determined. The end product of the reaction (with acetyl-CoA as the substrate) was identified as malonyl-CoA. The stoichiometry of the reaction was such that, for every mole of acetyl-CoA and adenosine triphosphate consumed, 1 mol each of malonyl-CoA, adenosine diphosphate, and orthophosphate was formed. These data provide the first evidence for the presence of another biotin-containing enzyme, an acyl-CoA carboxylase, in these bacteria in addition to the well-characterized methylmalonyl-CoA carboxyltransferase. PMID:6796564

  11. Chemiluminescent detection systems of horseradish peroxidase employing nucleophilic acylation catalysts.

    Science.gov (United States)

    Marzocchi, Ettore; Grilli, Stefano; Della Ciana, Leopoldo; Prodi, Luca; Mirasoli, Mara; Roda, Aldo

    2008-06-15

    The light output of the peroxidase-catalyzed luminol chemiluminescent oxidation reaction can be greatly increased by incorporating different enhancers. Such an increase is attributed to the preferential oxidation of the enhancer by peroxidase intermediates and the rapid formation of enhancer radicals that, in turn, quickly oxidize luminol to its radical anion. These enhancers, which include substituted phenols, substituted boronic acids, indophenols, and N-alkyl phenothiazines, behave as electron transfer mediators. A further, very significant increase in light output was also observed by the addition of nucleophilic acylation catalyst to the enhancer/luminol/oxidant substrate. The effect of the new component is general and applicable to many of the known enhancers but is much more remarkable in association with phenothiazine enhancers (up to 10-fold light output). The addition of a nucleophilic acylation catalyst to these substrates lowered the limit of detection for horseradish peroxidase from 50 to 8 amol. Similar improvements were observed in "sandwich" enzyme-linked immunosorbent assays and Western blot assays.

  12. N-acyl phosphatidylethanolamines affect the lateral distribution of cholesterol in membranes

    DEFF Research Database (Denmark)

    Térová, B.; Slotte, J.P.; Petersen, G.

    2005-01-01

    -acyl-POPE) or N-acyl-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (N-acyl-DPPE), and how the molecules interacted with cholesterol. The gel ¿ liquid crystalline transition temperature of sonicated N-acyl phosphatidylethanolamine vesicles in water correlated positively with the number of palmitic acyl chains...... in the molecules. Based on diphenylhexatriene steady state anisotropy measurements, the presence of 33 mol% cholesterol in the membranes removed the phase transition from N-oleoyl-POPE bilayers, but failed to completely remove it from N-palmitoyl-DPPE and N-palmitoyl-POPE bilayers, suggesting rather weak...... interaction of cholesterol with the N-saturated NAPEs. The rate of cholesterol desorption from mixed monolayers containing N-palmitoyl-DPPE and cholesterol (1:1 molar ratio) was much higher compared to cholesterol/DPPE binary monolayers, suggesting a weak cholesterol interaction with N-palmitoyl-DPPE also...

  13. 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

    DEFF Research Database (Denmark)

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

    2002-01-01

    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...... of ligand (excitation 387nm). Titration of FACI-24 and FACI-53 with hexadecanoyl-CoA and dodecanoyl-CoA increased the fluorescence yield 5.5-and 4.7-fold at 460 and 495nm respectively. FACI-24 exhibited a high, and similar increase in, fluorescence yield at 460nm upon binding of C14-C20 saturated...

  14. Syphilis-causing strains belong to separate SS14-like or Nichols-like groups as defined by multilocus analysis of 19 Treponema pallidum strains.

    Science.gov (United States)

    Nechvátal, Lukáš; Pětrošová, Helena; Grillová, Linda; Pospíšilová, Petra; Mikalová, Lenka; Strnadel, Radim; Kuklová, Ivana; Kojanová, Martina; Kreidlová, Miluše; Vaňousová, Daniela; Procházka, Přemysl; Zákoucká, Hana; Krchňáková, Alena; Smajs, David

    2014-07-01

    Treponema pallidum strains are closely related at the genome level but cause distinct diseases. Subspecies pallidum (TPA) is the causative agent of syphilis, subspecies pertenue (TPE) causes yaws while subspecies endemicum (TEN) causes bejel (endemic syphilis). Compared to the majority of treponemal genomic regions, several chromosomal loci were found to be more diverse. To assess genetic variability in diverse genomic positions, we have selected (based on published genomic data) and sequenced five variable loci, TP0304, TP0346, TP0488, TP0515 and TP0558, in 19 reference Treponema pallidum strains including all T. pallidum subspecies (TPA, TPE and TEN). Results of this multilocus analysis divided syphilitic isolates into two groups: SS14-like and Nichols-like. The SS14-like group is comprised of SS14, Grady, Mexico A and Philadelphia 1 strains. The Nichols-like group consisted of strains Nichols, Bal 73-1, DAL-1, MN-3, Philadelphia 2, Haiti B and Madras. The TP0558 locus was selected for further studies because it clearly distinguished between the SS14- and Nichols-like groups and because the phylogenetic tree derived from the TP0558 locus showed the same clustering pattern as the tree constructed from whole genome sequences. In addition, TP0558 was shown as the only tested locus that evolved under negative selection within TPA strains. Sequencing of a short fragment (573bp) of the TP0558 locus in a set of 25 clinical isolates from 22 patients collected in the Czech Republic during 2012-2013 revealed that clinical isolates follow the SS14- and Nichols-like distribution. Copyright © 2014 Elsevier GmbH. All rights reserved.

  15. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Science.gov (United States)

    2010-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting under...

  16. 40 CFR 721.7270 - 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs., chloride.

    Science.gov (United States)

    2010-07-01

    ...-trimethyl-N-soya acyl derivs., chloride. 721.7270 Section 721.7270 Protection of Environment ENVIRONMENTAL...-soya acyl derivs., chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs...

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Role of long-chain fatty acyl-CoA esters in the regulation of metabolism and in cell signalling

    DEFF Research Database (Denmark)

    Færgeman, Nils J.; Knudsen, J

    1997-01-01

    The intracellular concentration of free unbound acyl-CoA esters is tightly controlled by feedback inhibition of the acyl-CoA synthetase and is buffered by specific acyl-CoA binding proteins. Excessive increases in the concentration are expected to be prevented by conversion into acylcarnitines or...

  19. Liquid-liquid extraction and separation of VIII group elements, especially ruthenium, by synergic combinations or aromatic polyimines and micellar cationic exchangers

    International Nuclear Information System (INIS)

    Vitart, X.

    1991-01-01

    This thesis aims to characterize and to quantify the chemical equilibria involved in d-elements liquid-liquid extraction systems, especially elements belonging to the VIII group (Fe, Ni, Co, Ru, Rh, Pd, Pt). These systems are composed of synergic combination of aromatic polyimines and micellar cationic exchangers. Substitutions are first performed in aqueous acidic media by aromatic polyimines; then extractions are operated using micellic canionic exchangers. Chemical equilibria, selectivity effects, especially those due to ion-pair formations, kinetics, extractant behaviour are analysed and quantified [fr

  20. Inhibition of carnitine-acyl transferase I by oxfenicine studied in vivo with [11C]-labeled fatty acids

    International Nuclear Information System (INIS)

    Angsten, Gertrud; Valind, Sven; Takalo, Reijo; Neu, Henrik; Meurling, Staffan; Langstroem, Bengt

    2005-01-01

    Methods: Anesthetized pigs were studied with [ 11 C]-labeled fatty acids (FAs) with carbon chain length ranging from 8 to 16 carbon atoms, during control conditions and during inhibition of carnitine-palmitoyl transferase I (CPT I) with oxfenicine. The myocardial uptake of [ 11 C]-FAs from blood was measured together with the relative distribution of [ 11 C]-acyl-CoA between rapid mitochondrial oxidation and incorporation into slow turnover lipid pools in the heart. Results: During baseline conditions, the fractional oxidative utilization of palmitate was almost as high as that of carnitine-independent short-chain FAs, unless the carnitine shuttle was inhibited by high levels of lactate. Inhibition of CPT I almost completely blocked the oxidative pathway for palmitic acid and reduced the fractional oxidative utilization, while the rate of oxidative metabolism of acyl-CoA was unaffected. Conclusions: [ 11 C]-Labeled FAs allow rapid oxidation to be well separated from esterification into slow turnover lipid pools in the heart of anaesthetized pigs. The fractional oxidative utilization of [ 11 C]-palmitate serves well to characterize, in vivo, the carnitine-dependent transfer of long-chain FAs

  1. UWIS isotope separator

    International Nuclear Information System (INIS)

    Wojtasiewicz, A.

    1997-01-01

    Since 1995 the University of Warsaw Isotope Separator group has participated in the ISOL/IGISOL project at the Heavy Ion Cyclotron. This project consists in installation of an isotope separator (on line with cyclotron heavy ion beam) with a hot plasma ion source (ISOL system) and/or with an ion guide source (IGISOL system). In the report the short description of the present status of the project is presented

  2. Isotope separation

    International Nuclear Information System (INIS)

    Coleman, G.H.; Bett, R.; Cuninghame, J.G.; Sims, H.

    1982-01-01

    In the separation of short-lived isotopes for medical usage, a solution containing sup(195m)Hg is contacted with vicinal dithiol cellulose which adsorbs and retains the sup(195m)Hg. sup(195m)Au is eluted from the vicinal dithiol cellulose by using a suitable elutant. The sup(195m)Au arises from the radioactive decay of the sup(195m)Hg. The preferred elutant is a solution containing CN - ion. (author)

  3. Gas separating

    Science.gov (United States)

    Gollan, Arye Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  4. Central and peripheral des-acyl ghrelin regulates body temperature in rats.

    Science.gov (United States)

    Inoue, Yoshiyuki; Nakahara, Keiko; Maruyama, Keisuke; Suzuki, Yoshiharu; Hayashi, Yujiro; Kangawa, Kenji; Murakami, Noboru

    2013-01-04

    In the present study using rats, we demonstrated that central and peripheral administration of des-acyl ghrelin induced a decrease in the surface temperature of the back, and an increase in the surface temperature of the tail, although the effect of peripheral administration was less marked than that of central administration. Furthermore, these effects of centrally administered des-acyl ghrelin could not be prevented by pretreatment with [D-Lys3]-GHRP-6 GH secretagogue receptor 1a (GHS-R1a) antagonists. Moreover, these actions of des-acyl ghrelin on body temperature were inhibited by the parasympathetic nerve blocker methylscopolamine but not by the sympathetic nerve blocker timolol. Using immunohistochemistry, we confirmed that des-acyl ghrelin induced an increase of cFos expression in the median preoptic nucleus (MnPO). Additionally, we found that des-acyl ghrelin dilated the aorta and tail artery in vitro. These results indicate that centrally administered des-acyl ghrelin regulates body temperature via the parasympathetic nervous system by activating neurons in the MnPO through interactions with a specific receptor distinct from the GHS-R1a, and that peripherally administered des-acyl ghrelin acts on the central nervous system by passing through the blood-brain barrier, whereas it exerts a direct action on the peripheral vascular system. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Enzymatic Assays to Investigate Acyl-Homoserine Lactone Autoinducer Synthases.

    Science.gov (United States)

    Shin, Daniel; Nagarajan, Rajesh

    2018-01-01

    Bacteria use chemical molecules called autoinducers as votes to poll their numerical strength in a colony. This polling mechanism, commonly referred to as quorum sensing, enables bacteria to build a social network and provide a collective response for fighting off common threats. In Gram-negative bacteria, AHL synthases synthesize acyl-homoserine lactone (AHL) autoinducers to turn on the expression of several virulent genes including biofilm formation, protease secretion, and toxin production. Therefore, inhibiting AHL signal synthase would limit quorum sensing and virulence. In this chapter, we describe four enzymatic methods that could be adopted to investigate a broad array of AHL synthases. The enzymatic assays described here should accelerate our mechanistic understanding of quorum-sensing signal synthesis that could pave the way for discovery of potent antivirulence compounds.

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

    Directory of Open Access Journals (Sweden)

    Jindong Zan

    2014-01-01

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

  7. Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dae Sung; Joseph, Kristeen E.; Koehle, Maura; Krumm, Christoph; Ren, Limin; Damen, Jonathan N.; Shete, Meera H.; Lee, Han Seung; Zuo, Xiaobing; Lee, Byeongdu; Fan, Wei; Vlachos, Dionisios G.; Lobo, Raul F.; Tsapatsis, Michael; Dauenhauer, Paul J.

    2016-11-23

    An important advance in fluid surface control was the amphiphilic surfactant comprised of coupled molecular structures (i.e. hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e. hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel-Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water.

  8. Clarification of the Mechanism of Acylation Reaction and Origin of Substrate Specificity of the Serine-Carboxyl Peptidase Sedolisin through QM/MM Free Energy Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qin [ORNL; Yao, Jianzhuang [ORNL; Wiodawer, Alexander [SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD; Guo, Hong [ORNL

    2011-01-01

    Quantum mechanical/molecular mechanical (QM/MM) free energy simulations are applied for understanding the mechanism of the acylation reaction catalyzed by sedolisin, a representative serine-carboxyl peptidase, leading to the acyl-enzyme (AE) and first product from the enzyme-catalyzed reaction. One of the interesting questions to be addressed in this work is the origin of the substrate specificity of sedolisin that shows a relatively high activity on the substrates with Glu at P1 site. It is shown that the bond making and breaking events of the acylation reaction involving a peptide substrate (LLE*FL) seem to be accompanied by local conformational changes, proton transfers as well as the formation of alternative hydrogen bonds. The results of the simulations indicate that the conformational change of Glu at P1 site and its formation of a low barrier hydrogen bond with Asp-170 (along with the transient proton transfer) during the acylation reaction might play a role in the relatively high specificity for the substrate with Glu at P1 site. The role of some key residues in the catalysis is confirmed through free energy simulations. Glu-80 is found to act as a general base to accept a proton from Ser-287 during the nucleophilic attack and then as a general acid to protonate the leaving group (N H of P1 -Phe) during the cleavage of the scissile peptide bond. Another acidic residue, Asp-170, acts as a general acid catalyst to protonate the carbonyl of P1-Glu during the formation of the tetrahedral intermediate and as a general base for the formation of the acyl-enzyme. The energetic results from the free energy simulations support the importance of proton transfer from Asp-170 to the carbonyl of P1-Glu in the stabilization of the tetrahedral intermediate and the formation of a low-barrier hydrogen bond between the carboxyl group of P1-Glu and Asp-170 in the lowering of the free energy barrier for the cleavage of the peptide bond. Detailed analyses of the proton transfers

  9. An in vitro fatty acylation assay reveals a mechanism for Wnt recognition by the acyltransferase Porcupine.

    Science.gov (United States)

    Asciolla, James J; Miele, Matthew M; Hendrickson, Ronald C; Resh, Marilyn D

    2017-08-18

    Wnt proteins are a family of secreted signaling proteins that play key roles in regulating cell proliferation in both embryonic and adult tissues. Production of active Wnt depends on attachment of palmitoleate, a monounsaturated fatty acid, to a conserved serine by the acyltransferase Porcupine (PORCN). Studies of PORCN activity relied on cell-based fatty acylation and signaling assays as no direct enzyme assay had yet been developed. Here, we present the first in vitro assay that accurately recapitulates PORCN-mediated fatty acylation of a Wnt substrate. The critical feature is the use of a double disulfide-bonded Wnt peptide that mimics the two-dimensional structure surrounding the Wnt acylation site. PORCN-mediated Wnt acylation was abolished when the Wnt peptide was treated with DTT, and did not occur with a linear (non-disulfide-bonded) peptide, or when the double disulfide-bonded Wnt peptide contained Ala substituted for the Ser acylation site. We exploited this in vitro Wnt acylation assay to provide direct evidence that the small molecule LGK974, which is in clinical trials for managing Wnt-driven tumors, is a bona fide PORCN inhibitor whose IC 50 for inhibition of Wnt fatty acylation in vitro closely matches that for inhibition of Wnt signaling. Side-by-side comparison of PORCN and Hedgehog acyltransferase (HHAT), two enzymes that attach 16-carbon fatty acids to secreted proteins, revealed that neither enzyme will accept the other's fatty acyl-CoA or peptide substrates. These findings illustrate the unique enzyme-substrate selectivity exhibited by members of the membrane-bound O -acyl transferase family. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Particle separation

    International Nuclear Information System (INIS)

    Baker, C.A.

    1990-01-01

    Solid particles are separated from a liquid which also contains ferric hydroxide by subjecting the liquid to ultrasonic agitation from a transducer in order to break up the flocs so that they will pass with the liquid through a filter belt. The belt thus retains the solid particles without interference from the flocs. As shown the woven nylon belt collects rare radioactive solid particles from liquid and carries them under sensors. The belt is washed clean, with further ultrasonic agitation in a trough on its return run. (author)

  11. Gas separating

    Science.gov (United States)

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  12. Structure of human Fe-S assembly subcomplex reveals unexpected cysteine desulfurase architecture and acyl-ACP-ISD11 interactions.

    Science.gov (United States)

    Cory, Seth A; Van Vranken, Jonathan G; Brignole, Edward J; Patra, Shachin; Winge, Dennis R; Drennan, Catherine L; Rutter, Jared; Barondeau, David P

    2017-07-03

    In eukaryotes, sulfur is mobilized for incorporation into multiple biosynthetic pathways by a cysteine desulfurase complex that consists of a catalytic subunit (NFS1), LYR protein (ISD11), and acyl carrier protein (ACP). This NFS1-ISD11-ACP (SDA) complex forms the core of the iron-sulfur (Fe-S) assembly complex and associates with assembly proteins ISCU2, frataxin (FXN), and ferredoxin to synthesize Fe-S clusters. Here we present crystallographic and electron microscopic structures of the SDA complex coupled to enzyme kinetic and cell-based studies to provide structure-function properties of a mitochondrial cysteine desulfurase. Unlike prokaryotic cysteine desulfurases, the SDA structure adopts an unexpected architecture in which a pair of ISD11 subunits form the dimeric core of the SDA complex, which clarifies the critical role of ISD11 in eukaryotic assemblies. The different quaternary structure results in an incompletely formed substrate channel and solvent-exposed pyridoxal 5'-phosphate cofactor and provides a rationale for the allosteric activator function of FXN in eukaryotic systems. The structure also reveals the 4'-phosphopantetheine-conjugated acyl-group of ACP occupies the hydrophobic core of ISD11, explaining the basis of ACP stabilization. The unexpected architecture for the SDA complex provides a framework for understanding interactions with acceptor proteins for sulfur-containing biosynthetic pathways, elucidating mechanistic details of eukaryotic Fe-S cluster biosynthesis, and clarifying how defects in Fe-S cluster assembly lead to diseases such as Friedreich's ataxia. Moreover, our results support a lock-and-key model in which LYR proteins associate with acyl-ACP as a mechanism for fatty acid biosynthesis to coordinate the expression, Fe-S cofactor maturation, and activity of the respiratory complexes.

  13. Folylpolyglutamate synthetase: direct evidence for an acyl phosphate intermediate in the enzyme-catalyzed reaction

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, R.; McGuire, J.J.; Shane, B.; Coward, J.K.

    1986-05-01

    The nature of the intermediate in the reaction catalyzed by folylpoly-..gamma..-glutamate synthetase (FPGS) has been investigated. Incubation of ..cap alpha..,..gamma..-(/sup 18/O)methotrexate with ATP, glutamate, and FPGS resulted in the formation of (/sup 18/O)phosphate, thus providing strong evidence for the formation of a ..gamma..-glutamyl phosphate during catalysis. The inorganic phosphate formed in the enzyme-catalyzed reaction was separated from other products and substrates by chromatography on DEAE-cellulose, then converted to the trimethyl ester, and analyzed by mass spectroscopy. Stoichiometric formation of (/sup 18/O)phosphate was observed in the case of the E. coli enzyme, isolated from a transformant containing the cloned FPGS-dihydrofolate synthetase (folC) gene. In addition, /sup 31/P-NMR analysis of the phosphate isolated from the reaction using E. coli FPGS showed the expected /sup 18/O-isotopic perturbations due to both singly bonded and doubly bonded P-/sup 18/O species. Similar experiments were carried out with FPGS isolated from hog liver. In this case, the small amounts of pure enzyme available precluded use of the NMR technique. However, mass spectral analysis of the derivatized phosphate product revealed the presence of (/sup 18/O)-trimethyl phosphate, thus indicating that the reaction catalyzed by the mammalian enzyme also proceeds via an acyl phosphate intermediate.

  14. 1-alkenyl-2-acyl glycerol is an intermediate in myocardial plasmenylcholine biosynthesis

    International Nuclear Information System (INIS)

    Ford, D.; Gross, R.

    1987-01-01

    The present study was undertaken to identify the metabolic pathway(s) responsible for myocardial plasmenylcholine biosynthesis. Rabbit myocardium contained .46 +/- .09 nmol/g wet wight of 1-alkenyl-2-acyl glycerol (AAG) which predominantly consisted of 16:0 molecular species at the sn-1 position. Incubation of rabbit myocardial microsomes (RMM) with [ 14 C]CDP-choline ( 14 C-CDPC) resulted in the rapid incorporation of radiolabeled choline into the choline glycerophospholipid pool. RP-HPLC separation of molecular species demonstrated that nearly equal amounts of radiolabel were incorporated into plasmenylcholine and phosphatidylcholine subclasses despite the fact that RMM contained 21 times the mass of diacyl glycerol as compared to AAG. RMM incorporation of 14 C-CDPC into choline glycerophospholipids was substantially greater than incorporation of [ 14 C] phosphorylcholine or [ 14 C] choline. RMM incorporation of 14 C-CDPC into plasmalogen molecular species was stimulated two fold by 500 μM CMP. Taken together, these results demonstrate that rabbit myocardium contains substantial quantities of AAG and that endogenous AAG is an efficient precursor of myocardial plasmenylcholine

  15. SFGD: a comprehensive platform for mining functional information from soybean transcriptome data and its use in identifying acyl-lipid metabolism pathways.

    Science.gov (United States)

    Yu, Juan; Zhang, Zhenhai; Wei, Jiangang; Ling, Yi; Xu, Wenying; Su, Zhen

    2014-04-08

    Soybean (Glycine max L.) is one of the world's most important leguminous crops producing high-quality protein and oil. Increasing the relative oil concentration in soybean seeds is many researchers' goal, but a complete analysis platform of functional annotation for the genes involved in the soybean acyl-lipid pathway is still lacking. Following the success of soybean whole-genome sequencing, functional annotation has become a major challenge for the scientific community. Whole-genome transcriptome analysis is a powerful way to predict genes with biological functions. It is essential to build a comprehensive analysis platform for integrating soybean whole-genome sequencing data, the available transcriptome data and protein information. This platform could also be used to identify acyl-lipid metabolism pathways. In this study, we describe our construction of the Soybean Functional Genomics Database (SFGD) using Generic Genome Browser (Gbrowse) as the core platform. We integrated microarray expression profiling with 255 samples from 14 groups' experiments and mRNA-seq data with 30 samples from four groups' experiments, including spatial and temporal transcriptome data for different soybean development stages and environmental stresses. The SFGD includes a gene co-expression regulatory network containing 23,267 genes and 1873 miRNA-target pairs, and a group of acyl-lipid pathways containing 221 enzymes and more than 1550 genes. The SFGD also provides some key analysis tools, i.e. BLAST search, expression pattern search and cis-element significance analysis, as well as gene ontology information search and single nucleotide polymorphism display. The SFGD is a comprehensive database integrating genome and transcriptome data, and also for soybean acyl-lipid metabolism pathways. It provides useful toolboxes for biologists to improve the accuracy and robustness of soybean functional genomics analysis, further improving understanding of gene regulatory networks for effective

  16. Engineered Production of Short-Chain Acyl-Coenzyme A Esters in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Krink-Koutsoubelis, Nicolas; Loechner, Anne C.; Lechner, Anna

    2018-01-01

    Short-chain acyl-coenzyme A esters serve as intermediate compounds in fatty acid biosynthesis, and the production of polyketides, biopolymers and other value-added chemicals. S. cerevisiae is a model organism that has been utilized for the biosynthesis of such biologically and economically valuable...... compounds. However, its limited repertoire of short-chain acyl-CoAs effectively prevents its application as a production host for a plethora of natural products. Therefore, we introduced biosynthetic metabolic pathways to five different acyl-CoA esters into S. cerevisiae. Our engineered strains provide...

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

    OpenAIRE

    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...

  18. Selective biocatalytic acylation studies on 5′-O-(4,4′-Dimethoxytrityl)-2′,3′-Secouridine

    DEFF Research Database (Denmark)

    Singh, Sunil K.; Reddy, L. Chandrashekhar; Srivastava, Smriti

    2012-01-01

    Lipozyme® TL IM (Theremomyces lanuginosus lipase immobilized on silica) in toluene catalyzes the acylation of the 2( )'-OH over the 3( )'-OH group in 5( )'-O-(4,4( )'-dimethoxytrityl)-2( )',3( )'-secouridine (5( )'-O-DMT-2( )',3( )'-secouridine) in a highly selective fashion in moderate to almost...... quantitative yields. The turn over during benzoyl transfer reactions mediated by vinyl benzoate or benzoic anhydride was faster than in acyl transfer reactions with vinyl acetate or C(1) to C(5) acid anhydrides; except in the case of butanoic anhydride. The 2( )'-O-benzoyl-5( )'-O-DMT-2( )',3( )'-secouridine...

  19. Purification, crystallization and preliminary X-ray diffraction analysis of enoyl-acyl carrier protein reductase (FabK) from Streptococcus mutans strain UA159

    International Nuclear Information System (INIS)

    Kim, Tae-O; Im, Dong-Won; Jung, Ha Yun; Kwon, Seong Jung; Heo, Yong-Seok

    2012-01-01

    Enoyl-acyl carrier protein reductase (FabK) from S. mutans strain UA159 was cloned, overexpressed, purified and crystallized. X-ray diffraction data were collected to a resolution of 2.40 Å. A triclosan-resistant flavoprotein termed FabK is the sole enoyl-acyl carrier protein reductase in Streptococcus pneumoniae and Streptococcus mutans. In this study, FabK from S. mutans strain UA159 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.40 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P6 2 , with unit-cell parameters a = b = 105.79, c = 44.15 Å. The asymmetric unit contained one molecule, with a corresponding V M of 2.05 Å 3 Da −1 and a solvent content of 39.9%

  20. Isotope separation

    International Nuclear Information System (INIS)

    Bett, R.; Sims, H.E.; Cuninghame, J.G.

    1983-01-01

    sup(195m)Au is separated from sup(195m)Hg in a solution containing ions of sup(195m)Hg, wherein sup(195m)Au is generated by radioactive decay of the sup(195m)Hg, by contacting the solution with an adsorbing agent to adsorb the sup(195m)Hg as Hg ++ ions followed by elution of sup(195m)Au arising from said radioactive decay. The adsorbing agent is 3-thio-2-hydroxypropyl-ether-Sepharose (R.T.M.); sup(195m)Au may be prepared in this way in a medical isotope generator and is suitable for use in gamma-scan studies of heart action. (author)

  1. Selective catalytic hydrogenation of the N-acyl and uridyl double bonds in the tunicamycin family of protein N-glycosylation inhibitors.

    Science.gov (United States)

    Price, Neil Pj; Jackson, Michael A; Vermillion, Karl E; Blackburn, Judith A; Li, Jiakun; Yu, Biao

    2017-12-01

    Tunicamycin is a Streptomyces-derived inhibitor of eukaryotic protein N-glycosylation and bacterial cell wall biosynthesis, and is a potent and general toxin by these biological mechanisms. The antibacterial activity is dependent in part upon a π-π stacking interaction between the tunicamycin uridyl group and a specific Phe residue within MraY, a tunicamycin-binding protein in bacteria. We have previously shown that reducing the tunicamycin uridyl group to 5,6-dihydrouridyl (DHU) significantly lowers its eukaryotic toxicity, potentially by disrupting the π-stacking with the active site Phe. The present report compares the catalytic hydrogenation of tunicamycin and uridine with various precious metal catalysts, and describe optimum conditions for the selective production of N-acyl reduced tunicamycin or for tunicamycins reduced in both the N-acyl and uridyl double bonds. At room temperature, Pd-based catalysts are selective for the N-acyl reduction, whereas Rh-based catalysts favor the double reduction to provide access to fully reduced tunicamycin. The reduced DHU is highly base-sensitive, leading to amide ring opening under mild alkaline conditions.

  2. Group separation of transplutonium and rare earth elements by liquid chromatography with free stationary phase using 2,4,6-tris[ditolylphosphoryl] - 1,3,5 - triazine as extractant

    International Nuclear Information System (INIS)

    Chmutova, M.K.; Ivanova, L.A.; Bodrin, G.B.; Polikarpov, Yu.M.; Myasoedov, B.F.

    1994-01-01

    Methods of group separation of trace amounts of transplutonium elements (TPE) and weight amounts of rare earth elements (REE) in the systems on the basis of bifunctional neutral organophosphoric compounds by the method of liquid chromatography with a free stationary phase have been developed. When solution of 2,4,6 - tris[ditolylphosphoryl] - 1,3,5 - triazine in chloroform was used as stationary phase, REE were the first to be washed out by 0.5 mol/l NH 4 SCN-1 mol/l HCl solution, then TPE - by 0.025 mol/l of oxyethylidenediphosphonic acid in water. the fractions contained about 100% of one of the groups without impurity of the other. 7 refs.; 6 figs

  3. Diketones and ketoesters synthesis by acylation of substituted trimethylsilyl lithio-malonates

    International Nuclear Information System (INIS)

    Mayani, Mbutyabo

    1983-01-01

    The acylation of trimethylsilyl substituted lithio malonates with dicarbonyl-dichlorides and diacid monoester chlorides gives, after a simple hydrolysis by water, various diketones and ketoesters. The yields are generally good. The method is easy. (author) [fr

  4. Copper-mediated amidation of alkenylzirconocenes with acyl azides: formation of enamides.

    Science.gov (United States)

    Liu, Hailan; Zhou, Yiqing; Yan, Xiaoyu; Chen, Chao; Liu, Qingbin; Xi, Chanjuan

    2013-10-18

    Copper-mediated amidation of alkenylzirconocenes generated in situ from alkynes and zirconocenes with acyl azides is accomplished under mild conditions. The reaction can be used to prepare various enamides.

  5. Metabolic regulation of histone acetyltransferases by endogenous Acyl-CoA cofactors | Center for Cancer Research

    Science.gov (United States)

    Unraveling the metabolic regulation of lysine acetyltransferases (KATs). Montgomery et al. detail the application of a competitive chemoproteomic strategy to quantitatively characterize the interactions of acyl-CoA metabolites with cellular KAT enzymes.

  6. Covalent organic polymer functionalization of activated carbon surfaces through acyl chloride for environmental clean-up

    DEFF Research Database (Denmark)

    Mines, Paul D.; Thirion, Damien; Uthuppu, Basil

    2017-01-01

    Nanoporous networks of covalent organic polymers (COPs) are successfully grafted on the surfaces of activated carbons, through a series of surface modification techniques, including acyl chloride formation by thionyl chloride. Hybrid composites of activated carbon functionalized with COPs exhibit...

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

    DEFF Research Database (Denmark)

    Smelt, A H; Poorthuis, B J; Onkenhout, W

    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......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...... be due to residual enzyme activity as a consequence of the two missense mutations. Treatment with L-carnitine and medium chain triglycerides in the diet did not reduce the attacks of rhabdomyolysis....

  8. Separation, Separatism and Diversity.

    Science.gov (United States)

    Hasegawa, Maya

    1991-01-01

    In the United States, once legal integration was achieved and the White male culture was challenged for real power, minority groups began to question the wisdom of cultural and social integration and celebrate diversity. An acceptable line between healthy separation and unhealthy separatism must be found. (MSE)

  9. Fathering After Marital Separation

    Science.gov (United States)

    Keshet, Harry Finkelstein; Rosenthal, Kristine M.

    1978-01-01

    Deals with experiences of a group of separated or divorced fathers who chose to remain fully involved in the upbringing of their children. As they underwent transition from married parenthood to single fatherhood, these men learned that meeting demands of child care contributed to personal stability and growth. (Author)

  10. Metabolism of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine in the human neutrophil

    International Nuclear Information System (INIS)

    Triggiani, M.; D'Souza, D.M.; Chilton, F.H.

    1991-01-01

    The biosynthesis of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (1-acyl-2-acetyl-GPC) together with that of 1-alkyl-2-acetyl-GPC (platelet-activating factor) has been demonstrated in a variety of inflammatory cells and tissues. It has been hypothesized that the relative proportion of these phospholipids produced upon cell activation may be influenced by their rates of catabolism. We studied the catabolism of 1-acyl-2-acetyl-GPC in resting and activated human neutrophils and compared it to that of 1-alkyl-2-acetyl-GPC. Neutrophils rapidly catabolize both 1-alkyl-2-acetyl-GPC and 1-acyl-2-acetyl-GPC; however, the rate of catabolism of 1-acyl-2-acetyl-GPC is approximately 2-fold higher than that of 1-alkyl-2-acetyl-GPC. In addition, most of 1-acyl-2-acetyl-GPC is catabolized through a pathway different from that of 1-alkyl-2-acetyl-GPC. The main step in the catabolism of 1-acyl-2-acetyl-GPC is the removal of the long chain at the sn-1 position; the long chain residue is subsequently incorporated either into triglycerides or into phosphatidylcholine. The 1-lyso-2-acetyl-GPC formed in this reaction is then further degraded to glycerophosphocholine, choline, or phosphocholine. 1-Acyl-2-acetyl-GPC is also catabolized, to a lesser extent, through deacetylation at the sn-2 position and reacylation with a long chain fatty acid. Stimulation of neutrophils by A23187 results in a higher rate of catabolism of 1-acyl-2-acetyl-GPC by increasing both the removal of the long chain at the sn-1 position and the deacetylation-reacylation at the sn-2 position. In a broken cell preparation, the cytosolic fraction of the neutrophil was shown to contain an enzyme activity which cleaved the sn-1 position of 1-acyl-2-acetyl-GPC and 1-acyl-2-lyso-GPC but not of 1,2-diacyl-GPC

  11. Acyl carrier proteins from sunflower (Helianthus annuus L.) seeds and their influence on FatA and FatB acyl-ACP thioesterase activities.

    Science.gov (United States)

    Aznar-Moreno, Jose A; Venegas-Calerón, Mónica; Martínez-Force, Enrique; Garcés, Rafael; Salas, Joaquín J

    2016-08-01

    The kinetics of acyl-ACP thioesterases from sunflower importantly changed when endogenous ACPs were used. Sunflower FatB was much more specific towards saturated acyl-ACPs when assayed with them. Acyl carrier proteins (ACPs) are small (~9 kDa), soluble, acidic proteins involved in fatty acid synthesis in plants and bacteria. ACPs bind to fatty acids through a thioester bond, generating the acyl-ACP lipoproteins that are substrates for fatty acid synthase (FAS) complexes, and that are required for fatty acid chain elongation, acting as important intermediates in de novo fatty acid synthesis in plants. Plants, usually express several ACP isoforms with distinct functionalities. We report here the cloning of three ACPs from developing sunflower seeds: HaACP1, HaACP2, and HaACP3. These proteins were plastidial ACPs expressed strongly in seeds, and as such they are probably involved in the synthesis of sunflower oil. The recombinant sunflower ACPs were expressed in bacteria but they were lethal to the prokaryote host. Thus, they were finally produced using the GST gene fusion system, which allowed the apo-enzyme to be produced and later activated to the holo form. Radiolabelled acyl-ACPs from the newly cloned holo-ACP forms were also synthesized and used to characterize the activity of recombinant sunflower FatA and FatB thioesterases, important enzymes in plant fatty acids synthesis. The activity of these enzymes changed significantly when the endogenous ACPs were used. Thus, FatA importantly increased its activity levels, whereas FatB displayed a different specificity profile, with much high activity levels towards saturated acyl-CoA derivatives. All these data pointed to an important influence of the ACP moieties on the activity of enzymes involved in lipid synthesis.

  12. A liver-specific defect of Acyl-CoA degradation produces hyperammonemia, hypoglycemia and a distinct hepatic Acyl-CoA pattern.

    Directory of Open Access Journals (Sweden)

    Nicolas Gauthier

    Full Text Available Most conditions detected by expanded newborn screening result from deficiency of one of the enzymes that degrade acyl-coenzyme A (CoA esters in mitochondria. The role of acyl-CoAs in the pathophysiology of these disorders is poorly understood, in part because CoA esters are intracellular and samples are not generally available from human patients. We created a mouse model of one such condition, deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase (HL, in liver (HLLKO mice. HL catalyses a reaction of ketone body synthesis and of leucine degradation. Chronic HL deficiency and acute crises each produced distinct abnormal liver acyl-CoA patterns, which would not be predictable from levels of urine organic acids and plasma acylcarnitines. In HLLKO hepatocytes, ketogenesis was undetectable. Carboxylation of [2-(14C] pyruvate diminished following incubation of HLLKO hepatocytes with the leucine metabolite 2-ketoisocaproate (KIC. HLLKO mice also had suppression of the normal hyperglycemic response to a systemic pyruvate load, a measure of gluconeogenesis. Hyperammonemia and hypoglycemia, cardinal features of many inborn errors of acyl-CoA metabolism, occurred spontaneously in some HLLKO mice and were inducible by administering KIC. KIC loading also increased levels of several leucine-related acyl-CoAs and reduced acetyl-CoA levels. Ultrastructurally, hepatocyte mitochondria of KIC-treated HLLKO mice show marked swelling. KIC-induced hyperammonemia improved following administration of carglumate (N-carbamyl-L-glutamic acid, which substitutes for the product of an acetyl-CoA-dependent reaction essential for urea cycle function, demonstrating an acyl-CoA-related mechanism for this complication.

  13. Fatty acid acylation of proteins: specific roles for palmitic, myristic and caprylic acids

    Directory of Open Access Journals (Sweden)

    Rioux Vincent

    2016-05-01

    Full Text Available Fatty acid acylation of proteins corresponds to the co- or post-translational covalent linkage of an acyl-CoA, derived from a fatty acid, to an amino-acid residue of the substrate protein. The cellular fatty acids which are involved in protein acylation are mainly saturated fatty acids. Palmitoylation (S-acylation corresponds to the reversible attachment of palmitic acid (C16:0 via a thioester bond to the side chain of a cysteine residue. N-terminal myristoylation refers to the covalent attachment of myristic acid (C14:0 by an amide bond to the N-terminal glycine of many eukaryotic and viral proteins. Octanoylation (O-acylation typically concerns the formation of an ester bond between octanoic acid (caprylic acid, C8:0 and the side chain of a serine residue of the stomach peptide ghrelin. An increasing number of proteins (enzymes, hormones, receptors, oncogenes, tumor suppressors, proteins involved in signal transduction, eukaryotic and viral structural proteins have been shown to undergo fatty acid acylation. The addition of the acyl moiety is required for the protein function and usually mediates protein subcellular localization, protein-protein interaction or protein-membrane interaction. Therefore, through the covalent modification of proteins, these saturated fatty acids exhibit emerging specific and important roles in modulating protein functions. This review provides an overview of the recent findings on the various classes of protein acylation leading to the biological ability of saturated fatty acids to regulate many pathways. Finally, the nutritional links between these elucidated biochemical mechanisms and the physiological roles of dietary saturated fatty acids are discussed.

  14. Mild and Highly Efficient Copper(I Inspired Acylation of Alcohols and Polyols

    Directory of Open Access Journals (Sweden)

    Enoch A. Mensah

    2017-01-01

    Full Text Available A new and highly efficient method mediated by tetrakis(acetonitrilecopper(I triflate for activating both simple and highly hindered anhydrides in the acylation of alcohols and polyols is described. This new acylation method is mild and mostly proceeds at room temperature with low catalyst loading. The method is versatile and has been extended to a wide variety of different alcohol substrates to afford the corresponding ester products in good to excellent yields.

  15. Thioesterase activity and acyl-CoA/fatty acid cross-talk of hepatocyte nuclear factor-4{alpha}.

    Science.gov (United States)

    Hertz, Rachel; Kalderon, Bella; Byk, Tamara; Berman, Ina; Za'tara, Ghadeer; Mayer, Raphael; Bar-Tana, Jacob

    2005-07-01

    Hepatocyte nuclear factor-4alpha (HNF-4alpha) activity is modulated by natural and xenobiotic fatty acid and fatty acyl-CoA ligands as a function of their chain length, unsaturation, and substitutions. The acyl-CoA site of HNF-4alpha is reported here to consist of the E-F domain, to bind long-chain acyl-CoAs but not the respective free acids, and to catalyze the hydrolysis of bound fatty acyl-CoAs. The free acid pocket, previously reported in the x-ray structure of HNF-4alpha E-domain, entraps fatty acids but excludes acyl-CoAs. The acyl-CoA and free acid sites are distinctive and noncongruent. Free fatty acid products of HNF-4alpha thioesterase may exchange with free acids entrapped in the fatty acid pocket of HNF-4alpha. Cross-talk between the acyl-CoA and free fatty acid binding sites is abrogated by high affinity, nonhydrolyzable acyl-CoA ligands of HNF-4alpha that inhibit its thioesterase activity. Hence, HNF-4alpha transcriptional activity is controlled by its two interrelated acyl ligands and two binding sites interphased in tandem by the thioesterase activity. The acyl-CoA/free-acid and receptor/enzyme duality of HNF-4alpha extends the paradigm of nuclear receptors.

  16. O-acyl isopeptide method: development of an O-acyl isodipeptide unit for Boc SPPS and its application to the synthesis of Aβ1-42 isopeptide.

    Science.gov (United States)

    Yoshiya, Taku; Uemura, Tsuyoshi; Maruno, Takahiro; Kubo, Shigeru; Kiso, Yoshiaki; Sohma, Youhei; Kobayashi, Yuji; Yoshizawa-Kumagaye, Kumiko; Nishiuchi, Yuji

    2014-09-01

    The O-acyl isopeptide method was developed for the efficient preparation of difficult sequence-containing peptide. Furthermore, development of the O-acyl isodipeptide unit for Fmoc chemistry simplified its synthetic procedure by solid-phase peptide synthesis. Here, we report a novel isodipeptide unit for Boc chemistry, and the unit was successfully applied to the synthesis of amyloid β peptide. Combination of Boc chemistry and the isodipeptide unit would be an effective method for the synthesis of many difficult peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  17. Characterization of the mycobacterial acyl-CoA carboxylase holo complexes reveals their functional expansion into amino acid catabolism.

    Directory of Open Access Journals (Sweden)

    Matthias T Ehebauer

    2015-02-01

    Full Text Available Biotin-mediated carboxylation of short-chain fatty acid coenzyme A esters is a key step in lipid biosynthesis that is carried out by multienzyme complexes to extend fatty acids by one methylene group. Pathogenic mycobacteria have an unusually high redundancy of carboxyltransferase genes and biotin carboxylase genes, creating multiple combinations of protein/protein complexes of unknown overall composition and functional readout. By combining pull-down assays with mass spectrometry, we identified nine binary protein/protein interactions and four validated holo acyl-coenzyme A carboxylase complexes. We investigated one of these--the AccD1-AccA1 complex from Mycobacterium tuberculosis with hitherto unknown physiological function. Using genetics, metabolomics and biochemistry we found that this complex is involved in branched amino-acid catabolism with methylcrotonyl coenzyme A as the substrate. We then determined its overall architecture by electron microscopy and found it to be a four-layered dodecameric arrangement that matches the overall dimensions of a distantly related methylcrotonyl coenzyme A holo complex. Our data argue in favor of distinct structural requirements for biotin-mediated γ-carboxylation of α-β unsaturated acid esters and will advance the categorization of acyl-coenzyme A carboxylase complexes. Knowledge about the underlying structural/functional relationships will be crucial to make the target category amenable for future biomedical applications.

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

    International Nuclear Information System (INIS)

    Sato, Miho; Nakahara, Keiko; Goto, Shintaro; Kaiya, Hiroyuki; Miyazato, Mikiya; Date, Yukari; Nakazato, Masamitsu; Kangawa, Kenji; Murakami, Noboru

    2006-01-01

    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 [ 125 I]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

  19. Rheological behavior of acylated pepsin-solubilized collagen solutions: Effects of concentration

    Science.gov (United States)

    Li, Conghu; Duan, Lian; Tian, Zhenhua; Liu, Wentao; Li, Guoying; Huang, Xiaoping

    2015-11-01

    Effects of concentration on the rheological behavior of acylated pepsin-solubilized collagen solutions were investigated by steady shear tests, dynamic frequency sweep, creep tests and thixotropic loop measurements in this paper. The results showed that both acylated collagen and native collagen solutions exhibited the typical pseudoplastic behavior and displayed shear thinned behavior with the increase of shear rate. With the increase of acylated collagen concentrations from 5 to 10 mg/mL, shear viscosity, elasticity modulus ( G'), viscous modulus ( G″), complex viscosity ( η*), and the ability to resist deformation increased due to the physical entanglement, whilst loss tangent (tan δ) decreased. Additionally, with the increase of acylated collagen concentrations, the area of thixotropic loop increased from 6.94 to 44.40 watts/m3, indicating that the thixotropy of acylated collagen increased. Compared with native collagen solution, acylated collagen solution had stronger shear viscosity, η*, thixotropy, and ability to resist deformation. Furthermore, Power law model, Carreau model, Cross model, Leonov model and Burger model, were suitable for the fitting of the experimental data.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    Reinés, Mar; Llobet, Enrique; Dahlström, Käthe M; Pérez-Gutiérrez, Camino; Llompart, Catalina M; Torrecabota, Nuria; Salminen, Tiina A; Bengoechea, José A

    2012-01-01

    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 reduced activation of

  2. Separation techniques: Chromatography

    Science.gov (United States)

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  3. An Ultrahigh Resolution Structure of TEM-1 beta-Lactamase Suggests a Role for Glu166 as the General Base in Acylation

    Energy Technology Data Exchange (ETDEWEB)

    Minasov, George; Wang, Xiaojun; Shoichet, Brian K. (NWU)

    2010-03-08

    Although TEM-1 {beta}-lactamase is among the best studied enzymes, its acylation mechanism remains controversial. To investigate this problem, the structure of TEM-1 in complex with an acylation transition-state analogue was determined at ultrahigh resolution (0.85 {angstrom}) by X-ray crystallography. The quality of the data was such as to allow for refinement to an R-factor of 9.1% and an R{sub free} of 11.2%. In the resulting structure, the electron density features were clear enough to differentiate between single and double bonds in carboxylate groups, to identify multiple conformations that are occupied by residues and loops, and to assign 70% of the protons in the protein. Unexpectedly, even at pH 8.0 where the protein was crystallized, the active site residue Glu166 is clearly protonated. This supports the hypothesis that Glu166 is the general base in the acylation half of the reaction cycle. This structure suggests that Glu166 acts through the catalytic water to activate Ser70 for nucleophilic attack on the {beta}-lactam ring of the substrate. The hydrolytic mechanism of class A {beta}-lactamases, such as TEM-1, appears to be symmetrical, as are the serine proteases. Apart from its mechanistic implications, this atomic resolution structure affords an unusually detailed view of the structure, dynamics, and hydrogen-bonding networks of TEM-1, which may be useful for the design of inhibitors against this key antibiotic resistance target.

  4. Designing structural-motifs for the preparation of acylated proinsulin and their regiospecific conversion into insulin modified at Lys29 (K29).

    Science.gov (United States)

    Ahmad, Munir; Gardner, QurratulAnn Afza; Rashid, Naeem; Akhtar, Muhammad

    2017-08-01

    Eight proinsulin encoding genes were prepared and their translation products, when treated with a cocktail of trypsin and carboxypeptidase B, analyzed for the following features. One, their ability to undergo facile removal of the N-terminal linker, generating the phenylalanine residue destined to be the N-terminal of the B-chain of insulin, at a rate similar to that involved in the removal of the C-peptide. Two, processing of diarginyl insulin, produced in the latter process, by carboxypeptidase B then needed to be rapid to remove the two arginine residues, Three, both these operations were to be efficient whether the N-terminal methionine was acylated or not. Four, the proinsulin constructs needed to contain a minimum number of sites for acylation. The aforementioned features were monitored by mass spectrometry and the proinsulin derivative containing MRR at the N-terminal and K 64 mutated to Q 64 , designated as MRR-(Q 64 ) human proinsulin [MRR-(Q 64 ) hpi] optimally fulfilled these requirements. The derivative was smoothly acylated with reagents of two chain lengths (acetyl and dodecanoyl) to give acetyl/dodecanoyl MRR-(Q 64 ) hpi. Acetyl MRR-(Q 64 ) hpi, using the cocktail of the two enzymes, was smoothly converted into, acetyl insulin. However, when dodecanoyl MRR-(Q 64 ) hpi was processed with the above cocktail, carboxypeptidase B (whether from animal pancreas or recombinant) showed an unexpected specificity of acting on the K 29 -T 30 bond of the insulin derivatives when K 29 contained a large hydrophobic acyl group, generating dodecanoyl des-30 insulin. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Endogenous ecdysteroid levels and rates of ecdysone acylation by intact ovaries in vitro in relation to ovarian development in adult female crickets, Acheta domesticus.

    Science.gov (United States)

    Whiting, P; Sparks, S; Dinan, L

    1997-01-01

    Ecdysteroid titres have been determined in adult female house crickets (Acheta domesticus) in relation to reproductive maturation. Ecdysteroid levels in newly emerged adult females are low except in the gut and carcass, which probably reflects the remnants of the preecdysial ecdysteroid peak. Ecdysteroid levels in all compartments increase markedly once ovarian weight surpasses 10 mg. Apolar ecdysteroid conjugates (ecdysone 22-fatty acyl esters) predominate in ovarian tissue throughout ovarian maturation, but low levels of free ecdysteroid and polar conjugated ecdysteroids are also present. During this period, two peaks of ecdysteroids (mainly free and apolar conjugated ecdysteroids) are observed in the haemolymph, gut, and carcass compartments. The peaks in the haemolymph occur when the ovarian mass reaches 30 and 100 mg. The gut and carcass may be acting as sinks or sites of metabolism for the hormone released from the ovaries. The rate of ecdysone acylation by ovaries was found to be developmentally regulated, increasing from low levels in the immature ovaries of newly emerged females as the ovaries increase in size. A semiquantitative assay has been developed to identify compounds which inhibit the conversion of [3H]ecdysone into 22-fatty acyl [3H]ecdysone by ovaries in vitro. A number of ecdysteroids possessing a free hydroxyl group as C-22 as well as the side-chain stereochemistry of ecdysone effectively inhibit this conversion, probably by acting as competitive substrates. In the cases of 20-hydroxyecdysone and ponasterone A, it was clearly demonstrated that these compounds are converted to a mixture of C-22 fatty acyl esters. Several other compounds which have been suggested to affect ecdysteroid metabolism/mode of action in other systems were also tested for their effects on the acyltransferase activity of ovaries in vitro.

  6. Fractionation and Characterization of Tannin Acyl Hydrolase from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    YUNITA ARIAN SANI ANWAR

    2009-09-01

    Full Text Available We previously produced tannin acyl hydrolase (tannase from Aspergillus niger isolated from cacao pod. In the present study the enzyme was subjected to fractionation by ammonium sulphate followed by dialysis process. The saturation level of ammonium sulphate used was 30–80% where the best enzyme activity was obtained at the saturation level of 60%. Compared to that of crude enzyme, specific activity of tannase after dialysis was four folds. Characterization results showed that optimum activity was at 35–50 °C and pH 6. Tannase was activated by K+ and Na+ at concentration of 0.01 and 0.05 M respectively. Mg2+ was found activate tannase only at 0.01 M. Addition of metal ions like Zn2+, Cu2+, Ca2+, Mn2+ and Fe2+ inhibited the enzyme activity. Kinetics analysis of various substrates tested showed that the Km value of tannic acid and gallotannin was 0.401 and 6.611 mM respectively. Vmax value of tannic acid was 10.804 U/ml and of gallotannin was 12.406 U/ml. Based on Michaelis-Menten constant (Km, the tannase obtained in the present study was more active in hydrolysing depside bonds rather than ester bonds.

  7. New acylated flavonoid glycosides from flowers of Aerva javanica.

    Science.gov (United States)

    Mussadiq, Sara; Riaz, Naheed; Saleem, Muhammad; Ashraf, Muhammad; Ismail, Tayaba; Jabbar, Abdul

    2013-07-01

    Chromatographic purification of ethyl acetate soluble fraction of the methanolic extract of the flowers of Aerva javanica yielded three new acylated flavone glycosides: kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-galactoside (1), kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(3″-E-p-coumaroyl)galactoside (2), and kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(4″-E-p-coumaroyl)galactoside (3), along with p-coumaric acid (4), caffeic acid (5), gallic acid (6), eicosanyl-trans-p-coumarate (7), hexadecyl ferulate (8), and hexacosyl ferulate (9). The compounds 1-9 were characterized using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) and in comparison with the reported data in the literature. Compound 1 showed weak inhibitory activity against enzymes, such as acetylcholinesterase, butyrylcholinesterase, and lipoxygenase with IC50 values 205.1, 304.1, and 212.3 μM, respectively, whereas compounds 2 and 3 were only weakly active against the enzyme acetylcholinesterase.

  8. Defluoridation potential of jute fibers grafted with fatty acyl chain

    Science.gov (United States)

    Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam

    2015-11-01

    Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electro dialysis or reverse osmosis. These processes are often effective over narrow pH ranges, release ions considered hazardous to human health or produce large volumes of toxic sludge that are difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids, an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C-F bonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride.

  9. Acylated and unacylated ghrelin impair skeletal muscle atrophy in mice.

    Science.gov (United States)

    Porporato, Paolo E; Filigheddu, Nicoletta; Reano, Simone; Ferrara, Michele; Angelino, Elia; Gnocchi, Viola F; Prodam, Flavia; Ronchi, Giulia; Fagoonee, Sharmila; Fornaro, Michele; Chianale, Federica; Baldanzi, Gianluca; Surico, Nicola; Sinigaglia, Fabiola; Perroteau, Isabelle; Smith, Roy G; Sun, Yuxiang; Geuna, Stefano; Graziani, Andrea

    2013-02-01

    Cachexia is a wasting syndrome associated with cancer, AIDS, multiple sclerosis, and several other disease states. It is characterized by weight loss, fatigue, loss of appetite, and skeletal muscle atrophy and is associated with poor patient prognosis, making it an important treatment target. Ghrelin is a peptide hormone that stimulates growth hormone (GH) release and positive energy balance through binding to the receptor GHSR-1a. Only acylated ghrelin (AG), but not the unacylated form (UnAG), can bind GHSR-1a; however, UnAG and AG share several GHSR-1a-independent biological activities. Here we investigated whether UnAG and AG could protect against skeletal muscle atrophy in a GHSR-1a-independent manner. We found that both AG and UnAG inhibited dexamethasone-induced skeletal muscle atrophy and atrogene expression through PI3Kβ-, mTORC2-, and p38-mediated pathways in myotubes. Upregulation of circulating UnAG in mice impaired skeletal muscle atrophy induced by either fasting or denervation without stimulating muscle hypertrophy and GHSR-1a-mediated activation of the GH/IGF-1 axis. In Ghsr-deficient mice, both AG and UnAG induced phosphorylation of Akt in skeletal muscle and impaired fasting-induced atrophy. These results demonstrate that AG and UnAG act on a common, unidentified receptor to block skeletal muscle atrophy in a GH-independent manner.

  10. Acylation and metabolism of (n-6) fatty acids in hepatocytes

    International Nuclear Information System (INIS)

    Voss, A.C.; Sprecher, H.

    1986-01-01

    Isolated hepatocytes (5 x 10 6 in 2ml) from chow fed rats were incubated from 20 to 60 min. with increasing concentrations of [1- 14 C] labeled 18:2 (n-6), 18:3 (n-6) or 20:3 (n-6) to define optimum conditions for measuring acylation and metabolism to other (n-6) acids with subsequent incorporation into lipids. The triglycerides (TG) and phospholipids (PL) contained 157 and 80 nmols of 18:2 (n-6) and 6.0 and 6.1 nmols of other (n-6) acids, respectively, when cells were incubated with 0.3mM [1- 14 C] 18:2 (n-6) for 40 min. When cells were incubated with 0.3mM [1- 14 C] 18:2 (n-6) plus 0.15 to 0.45mM 18:3 (n-6) or 20:3 (n-6), the metabolism of 18:2 (n-6) to other (n-6) acids was inhibited but not totally abolished. These results may suggest that (n-6) acid made from linoleate do not totally equilibrate with exogenous 18:3 (n-6) or 20:3

  11. Acylated flavonol tri- and tetraglycosides in the flavonoid metabolome of Cladrastis kentukea (Leguminosae).

    Science.gov (United States)

    Kite, Geoffrey C; Rowe, Emily R; Lewis, Gwilym P; Veitch, Nigel C

    2011-04-01

    The foliar metabolome of Cladrastis kentukea (Leguminosae) contains a complex mixture of flavonoids including acylated derivatives of the 3-O-rhamnosyl(1→2)[rhamnosyl(1→6)]-galactosides of kaempferol and quercetin and their 7-O-rhamnosides, together with an array of non-acylated kaempferol and quercetin di-, tri- and tetraglycosides. Thirteen of the acylated flavonoids, 12 of which had not been reported previously, were characterised by spectroscopic and chemical methods. Eight of these were the four isomers of kaempferol 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E/Z-p-coumaroyl-β-d-galactopyranoside) and their 7-O-α-l-rhamnopyranosides, and three were isomers of quercetin 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E/Z-p-coumaroyl-β-d-galactopyranoside) - the remaining 4Z isomer was identified by LC-UV-MS analysis of a crude extract. The final two acylated flavonoids characterised by NMR were the 3E and 4E isomers of kaempferol 3-O-α-l-rhamnopyranosyl(1→2)[α-l-rhamnopyranosyl(1→6)]-(3/4-O-E-feruloyl-β-d-galactopyranoside)-7-O-α-l-rhamnopyranoside while the 3Z and 4Z isomers were again detected by LC-UV-MS. Using the observed fragmentation behaviour of the isolated compounds following a variety of MS experiments, a further 18 acylated flavonoids were given tentative structures by LC-MS analysis of a crude extract. Acylated flavonoids were absent from the flowers of C. kentukea, which contained an array of non-acylated kaempferol and quercetin glycosides. Immature fruits contained kaempferol 3-O-α-rhamnopyranosyl(1→2)[α-rhamnopyranosyl(1→6)]-β-galactopyranoside and its 7-O-α-rhamnopyranoside as the major flavonoids with acylated flavonoids, different from those in the leaves, only present as minor constituents. The presence of acylated flavonoids distinguishes the foliar flavonoid metabolome of C. kentukea from that of a closely related legume, Styphnolobium japonicum, which contains a similar

  12. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)

    2011-03-15

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)

  13. Two new separation schemes for the group isolation of rare earth elements (REE from biological and other matrices and their determination by ICP-MS, NAA and chromatographic methods

    Directory of Open Access Journals (Sweden)

    Dybczyński Rajmund S.

    2017-09-01

    Full Text Available Two new group separation schemes, based on ion exchange chromatography, for the selective and quantitative isolation of rare earth elements (REE from accompanying elements, were devised. After checking their performance with the aid of radioactive tracers, the schemes were further used together with ICP-MS, NAA and ion exchange chromatography for the determination of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in two certified reference materials (CRMs. The results were compared with another series of analyses, where the REEs were determined directly, i.e. without pre-separation, by instrumental neutron activation analysis (INAA and inductively coupled plasma mass spectrometry (ICP-MS. It was demonstrated that while direct INAA and ICP-MS in most instances provide reliable results for the majority of REEs, for some elements, notably Sc, Yb and Tm in the cases of ICP-MS and INAA, respectively, systematic errors occur or may potentially occur.

  14. Silyl-protective groups influencing the reactivity and selectivity in glycosylations

    DEFF Research Database (Denmark)

    Bols, Mikael; Pedersen, Christian Marcus

    2017-01-01

    Silyl groups such as TBDPS, TBDMS, TIPS or TMS are well-known and widely used alcohol protective groups in organic chemistry. Cyclic silylene protective groups are also becoming increasingly popular. In carbohydrate chemistry silyl protective groups have frequently been used primarily...... as an orthogonal protective group to the more commonly used acyl and benzyl protective groups. However, silyl protective groups have significantly different electronic and steric requirements than acyl and alkyl protective groups, which particularly becomes important when two or more neighboring alcohols are silyl...

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

    DEFF Research Database (Denmark)

    Mandrup, S; Jepsen, R; Skøtt, H

    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...

  16. Dihydrofolate synthetase and folylpolyglutamate synthetase: direct evidence for intervention of acyl phosphate intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, R.V.; Shane, B.; McGuire, J.J.; Coward, J.K.

    1988-12-13

    The transfer of /sup 17/O and/or /sup 18/O from (COOH-/sup 17/O or -/sup 18/O) enriched substrates to inorganic phosphate (P/sub i/) has been demonstrated for two enzyme-catalyzed reactions involved in folate biosynthesis and glutamylation. COOH-/sup 18/O-labeled folate, methotrexate, and dihydropteroate, in addition to (/sup 17/O)-glutamate, were synthesized and used as substrates for folylpolyglutamate synthetase (FPGS) isolated from Escherichia coli, hog liver, and rat liver and for dihydrofolate synthetase (DHFS) isolated from E. coli. P/sub i/ was purified from the reaction mixtures and converted to trimethyl phosphate (TMP), which was then analyzed for /sup 17/O and /sup 18/O enrichment by nuclear magnetic resonance (NMR) spectroscopy and/or mass spectroscopy. In the reactions catalyzed by the E. coli enzymes, both NMR and quantitative mass spectral analyses established that transfer of the oxygen isotope from the substrate /sup 18/O-enriched carboxyl group to P/sub i/ occurred, thereby providing strong evidence for an acyl phosphate intermediate in both the FPGS- and DHFS-catalyzed reactions. Similar oxygen-transfer experiments were carried out by use of two mammalian enzymes. The small amounts of P/sub i/ obtained from reactions catalyzed by these less abundant FPGS proteins precluded the use of NMR techniques. However, mass spectral analysis of the TMP derived from the mammalian FPGS-catalyzed reactions showed clearly that /sup 18/O transfer had occurred.

  17. Enzymatic Transesterification of Kraft Lignin with Long Acyl Chains in Ionic Liquids.

    Science.gov (United States)

    Hulin, Lise; Husson, Eric; Bonnet, Jean-Pierre; Stevanovic, Tatjana; Sarazin, Catherine

    2015-09-09

    Valorization of lignin is essential for the economic viability of the biorefinery concept. For example, the enhancement of lignin hydrophobicity by chemical esterification is known to improve its miscibility in apolar polyolefin matrices, thereby helping the production of bio-based composites. To this end and due to its many reactive hydroxyl groups, lignin is a challenging macromolecular substrate for biocatalyzed esterification in non-conventional media. The present work describes for the first time the lipase-catalyzed transesterification of Kraft lignin in ionic liquids (ILs). Three lipases, three 1-butyl-3-methylimidazolium based ILs and ethyl oleate as long chain acyl donor were selected. Best results were obtained with a hydrophilic/hydrophobic binary IL system (1-butyl-3-methylimidazolium trifluoromethanesulfonate/1-butyl-3-methylimidazolium hexafluoro- phosphate, 1/1 v/v) and the immobilized lipase B from Candida antarctica (CALB) that afforded a promising transesterification yield (ca. 30%). Similar performances were achieved by using 1-butyl-3-methylimidazolium hexafluorophosphate as a coating agent for CALB rather than as a co-solvent in 1-butyl-3-methylimidazolium trifluoromethane-sulfonate thus limiting the use of hydrophobic IL. Structural characterization of lignin oleate was performed by spectroscopic studies (FTIR and ¹H-NMR). The synthesized lignin oleate exhibited interesting thermal and textural properties, different from those of the original Kraft lignin.

  18. Enzymatic Transesterification of Kraft Lignin with Long Acyl Chains in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Lise Hulin

    2015-09-01

    Full Text Available Valorization of lignin is essential for the economic viability of the biorefinery concept. For example, the enhancement of lignin hydrophobicity by chemical esterification is known to improve its miscibility in apolar polyolefin matrices, thereby helping the production of bio-based composites. To this end and due to its many reactive hydroxyl groups, lignin is a challenging macromolecular substrate for biocatalyzed esterification in non-conventional media. The present work describes for the first time the lipase-catalyzed transesterification of Kraft lignin in ionic liquids (ILs. Three lipases, three 1-butyl-3-methylimidazolium based ILs and ethyl oleate as long chain acyl donor were selected. Best results were obtained with a hydrophilic/hydrophobic binary IL system (1-butyl-3-methylimidazolium trifluoromethanesulfonate/1-butyl-3-methylimidazolium hexafluoro- phosphate, 1/1 v/v and the immobilized lipase B from Candida antarctica (CALB that afforded a promising transesterification yield (ca. 30%. Similar performances were achieved by using 1-butyl-3-methylimidazolium hexafluorophosphate as a coating agent for CALB rather than as a co-solvent in 1-butyl-3-methylimidazolium trifluoromethane-sulfonate thus limiting the use of hydrophobic IL. Structural characterization of lignin oleate was performed by spectroscopic studies (FTIR and 1H-NMR. The synthesized lignin oleate exhibited interesting thermal and textural properties, different from those of the original Kraft lignin.

  19. Acute effect of exercise intensity and duration on acylated ghrelin and hunger in men.

    Science.gov (United States)

    Broom, David R; Miyashita, Masashi; Wasse, Lucy K; Pulsford, Richard; King, James A; Thackray, Alice E; Stensel, David J

    2017-03-01

    Acute exercise transiently suppresses the orexigenic gut hormone acylated ghrelin, but the extent to which exercise intensity and duration determine this response is not fully understood. The effects of manipulating exercise intensity and duration on acylated ghrelin concentrations and hunger were examined in two experiments. In experiment one, nine healthy males completed three, 4-h conditions (control, moderate-intensity running (MOD) and vigorous-intensity running (VIG)), with an energy expenditure of ~2.5 MJ induced in both MOD (55-min running at 52% peak oxygen uptake (V.O 2peak )) and VIG (36-min running at 75% V.O 2peak ). In experiment two, nine healthy males completed three, 9-h conditions (control, 45-min running (EX45) and 90-min running (EX90)). Exercise was performed at 70% V.O 2peak In both experiments, participants consumed standardised meals, and acylated ghrelin concentrations and hunger were quantified at predetermined intervals. In experiment one, delta acylated ghrelin concentrations were lower than control in MOD (ES = 0.44, P = 0.01) and VIG (ES = 0.98, P Hunger ratings were similar across the conditions (P = 0.35). In experiment two, delta acylated ghrelin concentrations were lower than control in EX45 (ES = 0.77, P Hunger ratings were lower than control in EX45 (ES = 0.20, P = 0.01) and EX90 (ES = 0.27, P = 0.001); EX45 and EX90 were similar (ES = 0.07, P = 0.34). Hunger and delta acylated ghrelin concentrations remained suppressed at 1.5 h in EX90 but not EX45. In conclusion, exercise intensity, and to a lesser extent duration, are determinants of the acylated ghrelin response to acute exercise. © 2017 Society for Endocrinology.

  20. Sunflower (Helianthus annuus) fatty acid synthase complex: enoyl-[acyl carrier protein]-reductase genes.

    Science.gov (United States)

    González-Thuillier, Irene; Venegas-Calerón, Mónica; Garcés, Rafael; von Wettstein-Knowles, Penny; Martínez-Force, Enrique

    2015-01-01

    Enoyl-[acyl carrier protein]-reductases from sunflower. A major factor contributing to the amount of fatty acids in plant oils are the first steps of their synthesis. The intraplastidic fatty acid biosynthetic pathway in plants is catalysed by type II fatty acid synthase (FAS). The last step in each elongation cycle is carried out by the enoyl-[ACP]-reductase, which reduces the dehydrated product of β-hydroxyacyl-[ACP] dehydrase using NADPH or NADH. To determine the mechanisms involved in the biosynthesis of fatty acids in sunflower (Helianthus annuus) seeds, two enoyl-[ACP]-reductase genes have been identified and cloned from developing seeds with 75 % identity: HaENR1 (GenBank HM021137) and HaENR2 (HM021138). The two genes belong to the ENRA and ENRB families in dicotyledons, respectively. The genetic duplication most likely originated after the separation of di- and monocotyledons. RT-qPCR revealed distinct tissue-specific expression patterns. Highest expression of HaENR1 was in roots, stems and developing cotyledons whereas that of H a ENR2 was in leaves and early stages of seed development. Genomic DNA gel blot analyses suggest that both are single-copy genes. In vivo activity of the ENR enzymes was tested by complementation experiments with the JP1111 fabI(ts) E. coli strain. Both enzymes were functional demonstrating that they interacted with the bacterial FAS components. That different fatty acid profiles resulted infers that the two Helianthus proteins have different structures, substrate specificities and/or reaction rates. The latter possibility was confirmed by in vitro analysis with affinity-purified heterologous-expressed enzymes that reduced the crotonyl-CoA substrate using NADH with different V max.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Acylation of cellular proteins with endogenously synthesized fatty acids

    International Nuclear Information System (INIS)

    Towler, D.; Glaser, L.

    1986-01-01

    A number of cellular proteins contain covalently bound fatty acids. Previous studies have identified myristic acid and palmitic acid covalently linked to protein, the former usually attached to proteins by an amide linkage and the latter by ester or thio ester linkages. While in a few instances specific proteins have been isolated from cells and their fatty acid composition has been determined, the most frequent approach to the identification of protein-linked fatty acids is to biosynthetically label proteins with fatty acids added to intact cells. This procedure introduces possible bias in that only a selected fraction of proteins may be labeled, and it is not known whether the radioactive fatty acid linked to the protein is identical with that which is attached to the protein when the fatty acid is derived from endogenous sources. We have examined the distribution of protein-bound fatty acid following labeling with [ 3 H]acetate, a general precursor of all fatty acids, using BC 3 H1 cells (a mouse muscle cell line) and A431 cells (a human epidermoid carcinoma). Myristate, palmitate, and stearate account for essentially all of the fatty acids linked to protein following labeling with [ 3 H]acetate, but at least 30% of the protein-bound palmitate in these cells was present in amide linkage. In BC3H1 cells, exogenous palmitate becomes covalently bound to protein such that less than 10% of the fatty acid is present in amide linkage. These data are compatible with multiple protein acylating activities specific for acceptor protein fatty acid chain length and linkage

  3. Laser isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re, and Tc. 9 claims, 1 drawing figure

  4. 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

    DEFF Research Database (Denmark)

    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...

  5. Long Chain N-acyl Homoserine Lactone Production by Enterobacter sp. Isolated from Human Tongue Surfaces

    Science.gov (United States)

    Yin, Wai-Fong; Purmal, Kathiravan; Chin, Shenyang; Chan, Xin-Yue; Chan, Kok-Gan

    2012-01-01

    We report the isolation of N-acyl homoserine lactone-producing Enterobacter sp. isolate T1-1 from the posterior dorsal surfaces of the tongue of a healthy individual. Spent supernatants extract from Enterobacter sp. isolate T1-1 activated the biosensor Agrobacterium tumefaciens NTL4(pZLR4), suggesting production of long chain AHLs by these isolates. High resolution mass spectrometry analysis of these extracts confirmed that Enterobacter sp. isolate T1-1 produced a long chain N-acyl homoserine lactone, namely N-dodecanoyl-homoserine lactone (C12-HSL). To the best of our knowledge, this is the first isolation of Enterobacter sp., strain T1-1 from the posterior dorsal surface of the human tongue and N-acyl homoserine lactones production by this bacterium. PMID:23202161

  6. Kinetic study on the inhibition of xanthine oxidase by acylated derivatives of flavonoids synthesised enzymatically.

    Science.gov (United States)

    de Araújo, Maria Elisa Melo Branco; Franco, Yollanda Edwirges Moreira; Alberto, Thiago Grando; Messias, Marcia Cristina Fernandes; Leme, Camila Wielewski; Sawaya, Alexandra Christine Helena Frankland; Carvalho, Patricia de Oliveira

    2017-12-01

    Studies have reported that flavonoids inhibit xanthine oxidase (XO) activity; however, poor solubility and stability in lipophilic media limit their bioavailability and applications. This study evaluated the kinetic parameters of XO inhibition and partition coefficients of flavonoid esters biosynthesised from hesperidin, naringin, and rutin via enzymatic acylation with hexanoic, octanoic, decanoic, lauric, and oleic acids catalysed by Candida antarctica lipase B (CALB). Quantitative determination by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) showed higher conversion yields (%) for naringin and rutin esters using acyl donors with 8C and 10C. Rutin decanoate had higher partition coefficients (0.95), and naringin octanoate and naringin decanoate showed greater inhibitory effects on XO (IC 50 of 110.35 and 117.51 μM, respectively). Kinetic analysis showed significant differences (p flavonoids before and after acylation regarding K m values, whereas the values for V max were the same, implying the competitive nature of XO inhibition.

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

    Directory of Open Access Journals (Sweden)

    Shaopeng Wei

    2013-03-01

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

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

    DEFF Research Database (Denmark)

    Neess, Ditte; Sørensen, Signe Bek; Engelsby, Hanne

    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...... studies have gained further insights into their in vivo functions and provided further evidence for ACBD-specific functions in cellular signaling and lipid metabolic pathways. This review summarizes the structural and functional properties of the various ACBDs, with special emphasis on the function...... 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...

  9. Phase behavior and nanoscale structure of phospholipid membranes incorporated with acylated C-14-peptides

    DEFF Research Database (Denmark)

    Pedersen, T.B.; Kaasgaard, Thomas; Jensen, M.O.

    2005-01-01

    The thermotropic phase behavior and lateral structure of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers containing an acylated peptide has been characterized by differential scanning calorimetry (DSC) on vesicles and atomic force microscopy (AFM) on mica-supported bilayers. The acylated...... peptide, which is a synthetic decapeptide N-terminally linked to a C-14 acyl chain (C-14-peptide), is incorporated into DPPC bilayers in amounts ranging from 0-20 mol %. The calorimetric scans of the two-component system demonstrate a distinct influence of the C-14-peptide on the lipid bilayer...... gel phase DPPC bilayers, inserts preferentially into preexisting defect regions and has a noticeable influence on the organization of the surrounding lipids. The presence of the C-14-peptide gives rise to a laterally heterogeneous bilayer structure with coexisting lipid domains characterized by a 10...

  10. Exploring the Leishmania Hydrophilic Acylated Surface Protein B (HASPB) Export Pathway by Live Cell Imaging Methods.

    Science.gov (United States)

    MacLean, Lorna; Price, Helen; O'Toole, Peter

    2016-01-01

    Leishmania major is a human-infective protozoan parasite transmitted by the bite of the female phlebotomine sand fly. The L. major hydrophilic acylated surface protein B (HASPB) is only expressed in infective parasite stages suggesting a role in parasite virulence. HASPB is a "nonclassically" secreted protein that lacks a conventional signal peptide, reaching the cell surface by an alternative route to the classical ER-Golgi pathway. Instead HASPB trafficking to and exposure on the parasite plasma membrane requires dual N-terminal acylation. Here, we use live cell imaging methods to further explore this pathway allowing visualization of key events in real time at the individual cell level. These methods include live cell imaging using fluorescent reporters to determine the subcellular localization of wild type and acylation site mutation HASPB18-GFP fusion proteins, fluorescence recovery after photobleaching (FRAP) to analyze the dynamics of HASPB in live cells, and live antibody staining to detect surface exposure of HASPB by confocal microscopy.

  11. In vivo test of the vertical phase separation hypothesis: the display of major histocompatibility complex (MHC) class I molecules on membranes of B cells from mice fed high-fat diets

    Science.gov (United States)

    Shaikh, Saame Raza; Boyle, Sarah; Hua, Jing; Li, Zhiping; Edidin, Michael

    2009-01-01

    The membrane vertical phase separation hypothesis predicts that a decrease in plasma membrane acyl chain order will increase major histocompatibility complex (MHC) class I surface expression. The hypothesis is based on modification of plasma membrane acyl chain order in cell culture and has not been tested in vivo. In the present study, we isolated splenic B cells from C57/BL6 mice fed either a normal diet or high-fat diets enriched in SFA or MUFA and assayed for changes in plasma membrane acyl chain order and MHC class I surface expression. Plasma membranes of B cells from MUFA-fed mice had significantly decreased acyl chain order and increased headgroup order. The decrease in acyl chain order correlated with a significant increase in the acyl chain unsaturation of B cells from the MUFA-fed mice. MHC class I surface levels on B cells were not affected by the MUFA-rich diet. This study suggests that the membrane vertical phase separation hypothesis may have limited application in a physiologically relevant setting. PMID:19283887

  12. Non-native acylated homoserine lactones reveal that LuxIR quorum sensing promotes symbiont stability.

    Science.gov (United States)

    Studer, Sarah V; Schwartzman, Julia A; Ho, Jessica S; Geske, Grant D; Blackwell, Helen E; Ruby, Edward G

    2014-08-01

    Quorum sensing, a group behaviour coordinated by a diffusible pheromone signal and a cognate receptor, is typical of bacteria that form symbioses with plants and animals. LuxIR-type N-acyl L-homoserine (AHL) quorum sensing is common in Gram-negative Proteobacteria, and many members of this group have additional quorum-sensing networks. The bioluminescent symbiont Vibrio fischeri encodes two AHL signal synthases: AinS and LuxI. AinS-dependent quorum sensing converges with LuxI-dependent quorum sensing at the LuxR regulatory element. Both AinS- and LuxI-mediated signalling are required for efficient and persistent colonization of the squid host, Euprymna scolopes. The basis of the mutualism is symbiont bioluminescence, which is regulated by both LuxI- and AinS-dependent quorum sensing, and is essential for maintaining a colonization of the host. Here, we used chemical and genetic approaches to probe the dynamics of LuxI- and AinS-mediated regulation of bioluminescence during symbiosis. We demonstrate that both native AHLs and non-native AHL analogues can be used to non-invasively and specifically modulate induction of symbiotic bioluminescence via LuxI-dependent quorum sensing. Our data suggest that the first day of colonization, during which symbiont bioluminescence is induced by LuxIR, is a critical period that determines the stability of the V. fischeri population once symbiosis is established. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Martinelle, M; Hult, K

    1995-09-06

    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.

  15. N-Acyl Amino Acids (Elmiric Acids): Endogenous Signaling Molecules with Therapeutic Potential.

    Science.gov (United States)

    Burstein, Sumner H

    2018-03-01

    The subject of N- acyl amino acid conjugates has been rapidly growing in recent years, especially with regard to their analgesic and anti-inflammatory actions. The field comprises a large family of lipid signaling molecules whose importance is only now being fully realized. The most widely studied member is N- arachidonoyl glycine (NAGly), which differs structurally from the endocannabinoid anandamide ( N- arachidonoyl ethanolamide) by a single oxygen atom even as the two are metabolically related. Topics that are covered in this minireview are: biosynthetic pathways for N- acyl amino acids, receptors for N- acyl amino acids, physiologic actions of N- acyl amino acids, pharmacological effects of N- acyl amino acids, and molecular mechanisms believed to be responsible for their effects. On the subject of mechanisms, we propose several possibilities whose basis is the currently available information. Four putative pathways can be suggested: 1) inhibition of fatty acid amide hydrolase-induced increases in anandamide or 2-arachidonoyl glycerol (2-AG) levels, resulting in analgesic activity; 2) binding to GPR18, initiating the production of anti-inflammatory eicosanoids (specifically, the data suggest roles for 15-deoxy-Δ 12,14 -prostaglandin-J 2 and lipoxin A 4 , both of which are potent inflammation-resolving molecules); 3) inactivation of T-type Cav3 channels; and 4) inhibition of the GLYT2 glycine transporter. Each pathway would produce analgesic effects. Also, the N- acyl amino acids do not bind to either cannabinoid or opioid receptors, thus reducing adverse actions and making them good templates for novel drug candidate molecules. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  16. Production of specific-structured lipids by enzymatic interesterification: elucidation of acyl migration by response surface design

    DEFF Research Database (Denmark)

    Xu, Xuebing; Skands, Anja; Høy, Carl-Erik

    1998-01-01

    Production of specific-structured lipids (SSL) by lipase-catalyzed interesterification has been attracting more and more attention recently. However, it was found that acyl migration occurs during the reaction and causes the production of by-products. In this paper, the elucidation of acyl migrat...

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

    Science.gov (United States)

    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. Inhibition of 3T3-L1 adipocyte differentiation by expression of acyl-CoA-binding protein antisense RNA

    DEFF Research Database (Denmark)

    Mandrup, S; Sorensen, R V; Helledie, T

    1998-01-01

    Several lines of evidence have recently underscored the significance of fatty acids or fatty acid-derived metabolites as signaling molecules in adipocyte differentiation. The acyl-CoA-binding protein (ACBP), which functions as an intracellular acyl-CoA pool former and transporter, is induced duri...

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

    DEFF Research Database (Denmark)

    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...

  20. Role of long-chain fatty acyl-CoA esters in the regulation of metabolism and in cell signalling

    DEFF Research Database (Denmark)

    Færgeman, Nils J.; Knudsen, J

    1997-01-01

    (Ki for acyl-CoA is 5 nM) indicates strongly that the free cytosolic acyl-CoA concentration is below 5 nM under these conditions. Only a limited number of the reported experiments on the effects of acyl-CoA on cellular functions and enzymes have been carried out at low physiological concentrations......The intracellular concentration of free unbound acyl-CoA esters is tightly controlled by feedback inhibition of the acyl-CoA synthetase and is buffered by specific acyl-CoA binding proteins. Excessive increases in the concentration are expected to be prevented by conversion into acylcarnitines...... or by hydrolysis by acyl-CoA hydrolases. Under normal physiological conditions the free cytosolic concentration of acyl-CoA esters will be in the low nanomolar range, and it is unlikely to exceed 200 nM under the most extreme conditions. The fact that acetyl-CoA carboxylase is active during fatty acid synthesis...

  1. Determination of medium chain acyl-CoA dehydrogenase activity in cultured skin fibroblasts using mass spectrometry

    NARCIS (Netherlands)

    Niezen-Koning, K E; Chapman, T E; Mulder, I E; Smit, G P; Reijngoud, D J; Berger, R

    1991-01-01

    Medium chain acyl-CoA dehydrogenase deficiency, a defect of mitochondrial beta-oxidation, is one of the most frequently occurring among inborn errors of metabolism. We describe a rapid and sensitive gas chromatographic/mass spectrometric method allowing reliable assessment of medium chain acyl-CoA

  2. An Unambiguous Nomenclature for the Acyl-quinic Acids Commonly Known as Chlorogenic Acids.

    Science.gov (United States)

    Abrankó, László; Clifford, Michael N

    2017-05-10

    The history of the acyl-quinic acids is briefly reviewed, the merits and limitations of the various nomenclature systems applicable are critically compared, and their limitations are highlighted, in particular their inability to provide an unambiguous description of all quinic acid enantiomers and diastereoisomers and associated acyl-quinic acids. Recommendations are made for a nomenclature system that in combination with IUPAC numbering achieves this objective. A comprehensive set of structures for the quinic acid enantiomers and diastereoisomers is presented. The Supporting Information provides an explanation of trivial names and a decision tree to determine which quinic acid isomer a structure represents.

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

    DEFF Research Database (Denmark)

    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. pHP-Tethered N-Acyl Carbamate: A Photocage for Nicotinamide.

    Science.gov (United States)

    Salahi, Farbod; Purohit, Vatsal; Ferraudi, Guillermo; Stauffacher, Cynthia; Wiest, Olaf; Helquist, Paul

    2018-04-13

    The synthesis of a new photocaged nicotinamide having an N-acyl carbamate linker and a p-hydroxyphenacyl (pHP) chromophore is described. The photophysical and photochemical studies showed an absorption maximum at λ = 330 nm and a quantum yield for release of 11% that are dependent upon both pH and solvent. While the acyl carbamate releases nicotinamide efficiently, a simpler amide linker was inert to photocleavage. This photocaged nicotinamide has significant advantages with respect to quantum yield, absorbance wavelength, rate of release, and solubility that make it the first practical example of a photocaged amide.

  5. Effect of room temperature ionic liquid structure on the enzymatic acylation of flavonoids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Enzymatic acylation reactions of flavonoids (rutin, esculin) with long chain fatty acids (palmitic, oleic acids) were carried out in 14 different ionic liquid media containing a range of cation and anion structures. Classification of RTILs according to flavonoid solubility (using COSMO...... must be struck that maximized flavonoid solubility with minimum negative impact on lipase activity. The process also benefitted from an increased reaction temperature which may have helped to reduced mass transfer limitations. Keywords: Room temperature ionic liquids (RTILs); Biosynthesis; Acylation......; Flavonoids; Lipase; Long chain fatty acids...

  6. Transport mechanism of acyl-CoA into peroxisomes by a peroxisomal ABC transporter, ABCD1

    OpenAIRE

    Agustina, Rina

    2016-01-01

    Transport mechanism of acyl-CoA into peroxisomes by a peroxisomal ABC protein, ABCD1 ABCD1, belonging to the ABC protein subfamily D, is aperoxisomal membrane protein and involves in the transport of very long chain fatty acid (VLCFA)-CoA into peroxisomes. Its mutation causes X-linked adrenoleukodystophy; an inborn error of peroxisomal VLCFA ??-oxidation. It has been reported that COMATOSE, a homolog of human ABCD1 in plant possess acyl-CoA thioesterase (ACOT) activity and t...

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

    DEFF Research Database (Denmark)

    Tran, Phuong Huong; Tran, Hai N.; Hansen, Poul Erik

    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 activity...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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 previous reports where peptide acylation enhanced membrane affinity but also resulted in impaired selectivity. Our result may provide a method of enhancing selectivity of antimicrobial peptides toward bacterial membranes due to their high negative charge—a finding that should be investigated for other...

  9. Macrocyclic prolinyl acyl guanidines as inhibitors of β-secretase (BACE).

    Science.gov (United States)

    Boy, Kenneth M; Guernon, Jason M; Wu, Yong-Jin; Zhang, Yunhui; Shi, Joe; Zhai, Weixu; Zhu, Shirong; Gerritz, Samuel W; Toyn, Jeremy H; Meredith, Jere E; Barten, Donna M; Burton, Catherine R; Albright, Charles F; Good, Andrew C; Grace, James E; Lentz, Kimberley A; Olson, Richard E; Macor, John E; Thompson, Lorin A

    2015-11-15

    The synthesis, evaluation, and structure-activity relationships of a class of acyl guanidines which inhibit the BACE-1 enzyme are presented. The prolinyl acyl guanidine chemotype (7c), unlike compounds of the parent isothiazole chemotype (1), yielded compounds with good agreement between their enzymatic and cellular potency as well as a reduced susceptibility to P-gp efflux. Further improvements in potency and P-gp ratio were realized via a macrocyclization strategy. The in vivo profile in wild-type mice and P-gp effects for the macrocyclic analog 21c is presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Exploring chemoselective S-to-N acyl transfer reactions in synthesis and chemical biology

    Science.gov (United States)

    Burke, Helen M.; McSweeney, Lauren; Scanlan, Eoin M.

    2017-05-01

    S-to-N acyl transfer is a high-yielding chemoselective process for amide bond formation. It is widely utilized by chemists for synthetic applications, including peptide and protein synthesis, chemical modification of proteins, protein-protein ligation and the development of probes and molecular machines. Recent advances in our understanding of S-to-N acyl transfer processes in biology and innovations in methodology for thioester formation and desulfurization, together with an extension of the size of cyclic transition states, have expanded the boundaries of this process well beyond peptide ligation. As the field develops, this chemistry will play a central role in our molecular understanding of Biology.

  11. Association of acylated cationic decapeptides with dipalmitoylphosphatidylserine-dipalmitoyl- phosphatidylcholine lipid membranes

    DEFF Research Database (Denmark)

    Pedersen, T. B.; Sabra, Mads Christian; Frokjaer, Sven

    2001-01-01

    decapeptides that are N-terminally linked with C-2, C-8, and C-14 acyl chains contain four basic histidine residues in their identical amino acid sequence. A binding model, based on changes in the intrinsic fluorescent properties of the peptides upon association with the DPPC-DPPS membranes, is used...... to estimate the peptide-membrane dissociation constants. The results clearly show that all three peptides have a higher affinity to liposomes containing DPPS lipids due to non-specific electrostatic interactions between the cationic peptides and the anionic DPPS lipids. Furthermore, it is found that the acyl...

  12. Novel C-9, 9'-O-acyl esters of (-)-carinol as free-radical scavengers and xanthine oxidase enzyme inhibitors: synthesis and biological evaluation.

    Science.gov (United States)

    Suryadevara, Praveen Kumar; Tatipaka, Hari Babu; Vidadala, Rama Subba Rao; Tiwari, Ashok K; Rao, Janaswamy Madhusudana; Babu, Katragadda Suresh

    2013-02-01

    New compounds with hydrophyllic esters of (-)-carinol were synthesized and evaluated as xanthine oxidase enzyme inhibitors and antioxidants. Aliphatic esterfication of C-9,9'-OH groups of (-)-carinol resulted in lowering antioxidant and xanthine oxidase inhibitory activities. However certain aromatic acyl esters considerably improved the xathine oxidase inhibition. Aromatic esterification with electron withdrawing substitutions would preferred for improvement in XOD inhibition while retaining radical scavenging activity, electron withdrawing substitution led to the loss of free radical scavenging property and neutral substituents decrease the enzyme inhibitory potential.

  13. Relationships Between Serum Interleukn-18 Concentration with Acylated Ghrelin, Growth Hormone, Insulin Resistance, and Lipid Profile in Obese and Lean Men

    Directory of Open Access Journals (Sweden)

    F Moradi

    2015-02-01

    Conclusions: The study findings revealed that in both groups of obese and lean men, serum levels of IL-18 positively correlated with insulin resistance and triglyceride, and negatively correlated with high-density lipoprotein. Furthermore, within obese individuals that have elevated IL-18 levels, this can be associated with disorder in glycemic control and lipid profile, and thus, with increased risk of cardiovascular and metabolic disorders. IL-18 levels do not appear to have any correlations with acylated ghrelin, growth hormone, total cholesterol, and low-density lipoprotein.

  14. Des-Acyl Ghrelin and Ghrelin O-Acyltransferase Regulate Hypothalamic-Pituitary-Adrenal Axis Activation and Anxiety in Response to Acute Stress

    NARCIS (Netherlands)

    Stark, R.; Santos, V.V.; Geenen, B.; Cabral, A.; Dinan, T.; Bayliss, J.A.; Lockie, S.H.; Reichenbach, A.; Lemus, M.B.; Perello, M.; Spencer, S.J.; Kozicz, L.T.; Andrews, Z.B.

    2016-01-01

    Ghrelin exists in two forms in circulation, acyl ghrelin and des-acyl ghrelin, both of which have distinct and fundamental roles in a variety of physiological functions. Despite this fact, a large proportion of papers simply measure and refer to plasma ghrelin without specifying the acylation

  15. Crystal structure of FAS thioesterase domain with polyunsaturated fatty acyl adduct and inhibition by dihomo-[gamma]-linolenic acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei; Chakravarty, Bornali; Zheng, Fei; Gu, Ziwei; Wu, Hongmei; Mao, Jianqiang; Wakil, Salih J.; Quiocho, Florante A. (Baylor)

    2012-05-29

    Human fatty acid synthase (hFAS) is a homodimeric multidomain enzyme that catalyzes a series of reactions leading to the de novo biosynthesis of long-chain fatty acids, mainly palmitate. The carboxy-terminal thioesterase (TE) domain determines the length of the fatty acyl chain and its ultimate release by hydrolysis. Because of the upregulation of hFAS in a variety of cancers, it is a target for antiproliferative agent development. Dietary long-chain polyunsaturated fatty acids (PUFAs) have been known to confer beneficial effects on many diseases and health conditions, including cancers, inflammations, diabetes, and heart diseases, but the precise molecular mechanisms involved have not been elucidated. We report the crystal structure of the hFAS TE domain covalently modified and inactivated by methyl {gamma}-linolenylfluorophosphonate. Whereas the structure confirmed the phosphorylation by the phosphonate head group of the active site serine, it also unexpectedly revealed the binding of the 18-carbon polyunsaturated {gamma}-linolenyl tail in a long groove-tunnel site, which itself is formed mainly by the emergence of an {alpha} helix (the 'helix flap'). We then found inhibition of the TE domain activity by the PUFA dihomo-{gamma}-linolenic acid; {gamma}- and {alpha}-linolenic acids, two popular dietary PUFAs, were less effective. Dihomo-{gamma}-linolenic acid also inhibited fatty acid biosynthesis in 3T3-L1 preadipocytes and selective human breast cancer cell lines, including SKBR3 and MDAMB231. In addition to revealing a novel mechanism for the molecular recognition of a polyunsaturated fatty acyl chain, our results offer a new framework for developing potent FAS inhibitors as therapeutics against cancers and other diseases.

  16. Structure of the Francisella tularensis enoyl-acyl carrier protein reductase (FabI) in complex with NAD+ and triclosan

    International Nuclear Information System (INIS)

    Mehboob, Shahila; Truong, Kent; Santarsiero, Bernard D.; Johnson, Michael E.

    2010-01-01

    Structure of the ternary complex of F. tularensis enoyl-acyl carrier protein reductase reveals the structure of the substrate binding loop whose electron density was missing in an earlier structure, and demonstrates a shift in the position of the NAD + cofactor. Enoyl-acyl carrier protein reductase (FabI) catalyzes the last rate-limiting step in the elongation cycle of the fatty-acid biosynthesis pathway and has been validated as a potential antimicrobial drug target in Francisella tularensis. The development of new antibiotic therapies is important both to combat potential drug-resistant bioweapons and to address the broader societal problem of increasing antibiotic resistance among many pathogenic bacteria. The crystal structure of FabI from F. tularensis (FtuFabI) in complex with the inhibitor triclosan and the cofactor NAD + has been solved to a resolution of 2.1 Å. Triclosan is known to effectively inhibit FabI from different organisms. Precise characterization of the mode of triclosan binding is required to develop highly specific inhibitors. Comparison of our structure with the previously determined FtuFabI structure which is bound to only NAD + reveals the conformation of the substrate-binding loop, electron density for which was missing in the earlier structure, and demonstrates a shift in the conformation of the NAD + cofactor. This shift in the position of the phosphate groups allows more room in the active site for substrate or inhibitor to bind and be better accommodated. This information will be crucial for virtual screening studies to identify novel scaffolds for development into new active inhibitors

  17. Unraveling the degradation of artificial amide bonds in nylon oligomer hydrolase: from induced-fit to acylation processes.

    Science.gov (United States)

    Baba, Takeshi; Boero, Mauro; Kamiya, Katsumasa; Ando, Hiroyuki; Negoro, Seiji; Nakano, Masayoshi; Shigeta, Yasuteru

    2015-02-14

    To elucidate how the nylon oligomer hydrolase (NylB) acquires its peculiar degradation activity towards non-biological amide bonds, we inspected the underlying enzymatic processes going from the induced-fit upon substrate binding to acylation. Specifically we investigated the mutational effects of two mutants, Y170F and D181G, indicated in former experiments as crucial systems because of their specific amino acid residues. Therefore, by adopting first-principles molecular dynamics complemented with metadynamics we provide a detailed insight into the underlying acylation mechanism. Our results show that while in the wild type (WT) the Tyr170 residue points the NH group towards the proton-acceptor site of an artificial amide bond, hence ready to react, in the Y170F this does not occur. The reason is ascribed to the absence of Tyr170 in the mutant, which is replaced by phenylalanine, which is unable to form hydrogen bond with the amide bond; thus, resulting in an increase in the activation barrier of more than 10 kcal mol(-1). Nonetheless, despite the lack of hydrogen bonding between the Y170F and the substrate, the highest free energy barrier for the induced-fit is similar to that of WT. This seems to suggest that in the induced-fit process, kinetics is little affected by the mutation. On the basis of additional structural homology analyses on the enzymes of the same family, we suggest that natural selection is responsible for the development of the peculiar hydrolytic activity of Arthrobacter sp. KI72.

  18. A bacterial acyl aminoacyl peptidase couples flexibility and stability as a result of cold adaptation.

    Science.gov (United States)

    Brocca, Stefania; Ferrari, Cristian; Barbiroli, Alberto; Pesce, Alessandra; Lotti, Marina; Nardini, Marco

    2016-12-01

    Life in cold environments requires an overall increase in the flexibility of macromolecular and supramolecular structures to allow biological processes to take place at low temperature. Conformational flexibility supports high catalytic rates of enzymes in the cold but in several cases is also a cause of instability. The three-dimensional structure of the psychrophilic acyl aminoacyl peptidase from Sporosarcina psychrophila (SpAAP) reported in this paper highlights adaptive molecular changes resulting in a fine-tuned trade-off between flexibility and stability. In its functional form SpAAP is a dimer, and an increase in flexibility is achieved through loosening of intersubunit hydrophobic interactions. The release of subunits from the quaternary structure is hindered by an 'arm exchange' mechanism, in which a tiny structural element at the N terminus of one subunit inserts into the other subunit. Mutants lacking the 'arm' are monomeric, inactive and highly prone to aggregation. Another feature of SpAAP cold adaptation is the enlargement of the tunnel connecting the exterior of the protein with the active site. Such a wide channel might compensate for the reduced molecular motions occurring in the cold and allow easy and direct access of substrates to the catalytic site, rendering transient movements between domains unnecessary. Thus, cold-adapted SpAAP has developed a molecular strategy unique within this group of proteins: it is able to enhance the flexibility of each functional unit while still preserving sufficient stability. Structural data are available in the Protein Data Bank under the accession number 5L8S. © 2016 Federation of European Biochemical Societies.

  19. Thermodynamically based solvent design for enzymatic saccharide acylation with hydroxycinnamic acids in non-conventional media.

    Science.gov (United States)

    Zeuner, Birgitte; Kontogeorgis, Georgios M; Riisager, Anders; Meyer, Anne S

    2012-02-15

    Enzyme-catalyzed synthesis has been widely studied with lipases (EC 3.1.1.3), but feruloyl esterases (FAEs; EC 3.1.1.73) may provide advantages such as higher substrate affinity and regioselectivity in the synthesis of hydroxycinnamate saccharide esters. These compounds are interesting because of their amphiphilicity and antioxidative potential. Synthetic reactions using mono- or disaccharides as one of the substrates may moreover direct new routes for biomass upgrading in the biorefinery. The paper reviews the available data for enzymatic hydroxycinnamate saccharide ester synthesis in organic solvent systems as well as other enzymatic hydroxycinnamate acylations in ionic liquid systems. The choice of solvent system is highly decisive for enzyme stability, selectivity, and reaction yields in these synthesis reactions. To increase the understanding of the reaction environment and to facilitate solvent screening as a crucial part of the reaction design, the review explores the use of activity coefficient models for describing these systems and - more importantly - the use of group contribution model UNIFAC and quantum chemistry based COSMO-RS for thermodynamic predictions and preliminary solvent screening. Surfactant-free microemulsions of a hydrocarbon, a polar alcohol, and water are interesting solvent systems because they accommodate different substrate and product solubilities and maintain enzyme stability. Ionic liquids may provide advantages as solvents in terms of increased substrate and product solubility, higher reactivity and selectivity, as well as tunable physicochemical properties, but their design should be carefully considered in relation to enzyme stability. The treatise shows that thermodynamic modeling tools for solvent design provide a new toolbox to design enzyme-catalyzed synthetic reactions from biomass sources. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. SEPARATION OF PLUTONIUM

    Science.gov (United States)

    Maddock, A.G.; Smith, F.

    1959-08-25

    A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

  1. New bradykinin analogues acylated on the N-terminus: effect on rat uterus and blood pressure

    Czech Academy of Sciences Publication Activity Database

    Labudda, O.; Wierzba, T.; Sobolewski, D.; Sleszyňska, M.; Gawiňski, L.; Plačková, Malgorzata; Slaninová, Jiřina; Prahl, A.

    2007-01-01

    Roč. 54, č. 1 (2007), s. 193-198 ISSN 0001-527X Grant - others:State Comittee for Scientific Research(PL) PB1108/T09/2005/28 Institutional research plan: CEZ:AV0Z40550506 Keywords : bradykinin * antagonists * acylation Subject RIV: CE - Biochemistry Impact factor: 1.261, year: 2007 www.actabp.pl

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

    DEFF Research Database (Denmark)

    Andersen, Jens Bo; Heydorn, Arne; Hentzer, Morten

    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...

  3. Fast screening method for detection of acyl-HSL-degrading soil isolates

    NARCIS (Netherlands)

    Jafra, S.; Wolf, van der J.M.

    2004-01-01

    A reliable method was developed for screening of bacteria isolates capable of degrading acyl-HSLs, the signal molecules in quorum-sensing-mediated processes of many Proteobacteria. The microtiter assay was based on the use of a GFP-marked Escherichia coli strain, which fluoresces upon the presence

  4. Equine biochemical multiple acyl-CoA dehydrogenase deficiency (MADD) as a cause of rhabdomyolysis

    NARCIS (Netherlands)

    Westermann, C. M.; de Sain-van der Velden, M. G. M.; van der Kolk, J. H.; Berger, R.; Wijnberg, I. D.; Koeman, J. P.; Wanders, R. J. A.; Lenstra, J. A.; Testerink, N.; Vaandrager, A. B.; Vianey-Saban, C.; Acquaviva-Bourdain, C.; Dorland, L.

    2007-01-01

    Two horses (a 7-year-old Groninger warmblood gelding and a six-month-old Trakehner mare) with pathologically confirmed rhabdomyolysis were diagnosed as suffering from multiple acyl-CoA dehydrogenase deficiency (MADD). This disorder has not been recognised in animals before. Clinical signs of both

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

    Czech Academy of Sciences Publication Activity Database

    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

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

    Czech Academy of Sciences Publication Activity Database

    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

  7. Purification of peroxisomal acyl-CoA: dihydroxyacetonephosphate acyltransferase from human placenta

    NARCIS (Netherlands)

    Ofman, R.; Wanders, R. J.

    1994-01-01

    The peroxisomal enzyme acyl-CoA:dihydroxyacetonephosphate acyltransferase (DHAPAT) was extracted from human placental membranes using CHAPS as a detergent in the presence of 1 M KCl. Prior to assay dipalmitoylphosphatidylcholine was added to the sample as eluted from the various columns in order to

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

    NARCIS (Netherlands)

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

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

  9. Cloning of a novel stearoyl-acyl desaturase gene from white ash ...

    African Journals Online (AJOL)

    Cloning of a novel stearoyl-acyl desaturase gene from white ash (Fraxinus americana) and evolution analysis with those from other plants. G Chen, ZK Xing, WL Pan, LP Bai, JF Ye, DJ Ma, ZP Wei, JG Fan, ZF Guo ...

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

    Czech Academy of Sciences Publication Activity Database

    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: 3.349, year: 2015

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

    KAUST Repository

    Li, Wenjun

    2017-02-15

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

  12. Antipathogenic potential of marine Bacillus sp. SS4 on N-acyl ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 36; Issue 1. Antipathogenic potential of marine Bacillus sp. SS4 on N-acyl-homoserine-lactone-mediated virulence factors production in Pseudomonas aeruginosa (PAO1). K Syed Musthafa V Saroja S Karutha Pandian A Veera Ravi. Articles Volume 36 Issue 1 March 2011 ...

  13. Adult peroxisomal acyl-coenzyme A oxidase deficiency with cerebellar and brainstem atrophy

    NARCIS (Netherlands)

    Ferdinandusse, S.; Barker, S.; Lachlan, K.; Duran, M.; Waterham, H.R.; Wanders, R.J.A.; Hammans, S.

    2010-01-01

    Peroxisomal acyl-coenzyme A oxidase deficiency ( formerly also called pseudoneonatal adrenoleucodystrophy) is a disorder of peroxisomal fatty acid oxidation with a severe presentation. Most patients present at birth or in early infancy, and the mean age of death was 5 years in a recently published

  14. Synthesis of Di -Acyl Triazene – N – Oxide | Edema | Nigerian ...

    African Journals Online (AJOL)

    dimethyl aniline with some acyl hydrazines. The product yield varied from 56% - 80.8%. The conditions for optimum yields and spectral characteristics of the products are reported. Nigerian Journal of Chemical Research Vol. 11 2006: pp. 11-14 ...

  15. Antipathogenic potential of marine Bacillus sp. SS4 on N-acyl ...

    Indian Academy of Sciences (India)

    Antipathogenic therapy is an outcome of the quorum-sensing inhibition (QSI) mechanism, which targets autoinducer-dependent virulent gene expression in bacterial pathogens. -acyl homoserine lactone (AHL) acts as a key regulator in the production of virulence factors and biofilm formation in Pseudomonas aeruginosa ...

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

    DEFF Research Database (Denmark)

    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 desc...

  17. An Efficient and Green Procedure for the Preparation of Acylals from ...

    African Journals Online (AJOL)

    An Efficient and Green Procedure for the Preparation of Acylals from Aldehydes Catalyzed by Alum [KAl(SO 4 ) 2 .12H 2 O] ... South African Journal of Chemistry ... mild reaction conditions, short reaction times and excellent yields, and offers a green synthetic solution by avoiding toxic catalysts and hazardous solvents.

  18. Highly selective synthesis of acetylferrocene by acylation of ferrocene over zeolites

    Czech Academy of Sciences Publication Activity Database

    Voláková, Martina; Zones, S. I.; Čejka, Jiří

    2007-01-01

    Roč. 327, č. 2 (2007), s. 255-260 ISSN 0926-860X R&D Projects: GA AV ČR IAB4040201; GA ČR GA104/07/0383 Institutional research plan: CEZ:AV0Z40400503 Keywords : acetylferrocene * acylation * zeolites * structural types Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.166, year: 2007

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

    DEFF Research Database (Denmark)

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

    2001-01-01

    The cause and effects of acyl migration during the purification of specific structured lipids by distillation were studied in a conventional batch deodorizer with stripping steam. The mixture of specific structured lipids produced by lipase-catalyzed acidolysis between rapeseed oil and capric acid...

  20. Improved Synthesis of 1-O-Acyl-β-d-Glucopyranose Tetraacetates

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2017-04-01

    Full Text Available An improved synthesis of 1-O-acyl glucosyl esters that avoids the use of expensive Ag reagents as well as the hydrolysis of unstable glucosyl bromides is reported. Notably, β-configuration products were obtained exclusively in good yields.

  1. Clinical, biochemical, and genetic heterogeneity in short-chain acyl-coenzyme A dehydrogenase deficiency

    NARCIS (Netherlands)

    van Maldegem, Bianca T.; Duran, Marinus; Wanders, Ronald J. A.; Niezen-Koning, Klary E.; Hogeveen, Marije; Ijlst, Lodewijk; Waterham, Hans R.; Wijburg, Frits A.

    2006-01-01

    Context Short-chain acyl-coenzyme A (CoA) dehydrogenase (SCAD) deficiency (SCADD) is an autosomal recessive, clinically heterogeneous disorder with only 22 case reports published so far. Screening for SCADD is included in expanded newborn screening programs in most US and Australian states.

  2. Clinical aspects of short-chain acyl-CoA dehydrogenase deficiency

    NARCIS (Netherlands)

    van Maldegem, Bianca T.; Wanders, Ronald J. A.; Wijburg, Frits A.

    2010-01-01

    Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation. SCADD is biochemically characterized by increased C4-carnitine in plasma and ethylmalonic acid in urine. The diagnosis of SCADD is confirmed by DNA analysis showing

  3. Clinical, biochemical, and genetic heterogeneity in short-chain acyl-coenzyme A dehydrogenase deficiency

    NARCIS (Netherlands)

    van Maldegem, Bianca T.; Duran, Marinus; Wanders, Ronald J. A.; Niezen-Koning, Klary E.; Hogeveen, Marije; Ijlst, Lodewijk; Waterham, Hans R.; Wijburg, Frits A.

    2006-01-01

    CONTEXT: Short-chain acyl-coenzyme A (CoA) dehydrogenase (SCAD) deficiency (SCADD) is an autosomal recessive, clinically heterogeneous disorder with only 22 case reports published so far. Screening for SCADD is included in expanded newborn screening programs in most US and Australian states.

  4. Homochiral Acyl Isocyanates as Diagnostic NMR Probes for the Enantiomeric Purity of Chiral Alcohols

    Directory of Open Access Journals (Sweden)

    Gregory H. P. Roos

    2000-12-01

    Full Text Available The first reported acyl and sulfonylisocyanates were developed and tested in reactions with chiral alcohols to afford diastereomeric carbamates. NMR analysis of these investigates the chemical shift discrimination that would allow these activated isocyanates to be used as diagnostic probes of enantiomeric purity.

  5. Acylation of aromatic alcohols and phenols over InCl3 ...

    Indian Academy of Sciences (India)

    Unknown

    corrosion problems etc. Development of easily sepa- rable and reusable solid catalyst having high activity for the acylation reaction is, therefore, of great prac- tical importance. Recently, a few studies10,11 have been reported on the use of acidic solid catalysts viz. commercial HY zeolite10 and montmorillonite. K-10 or KSF ...

  6. Uncovering Key Structural Features of an Enantioselective Peptide-Catalyzed Acylation Utilizing Advanced NMR Techniques

    Czech Academy of Sciences Publication Activity Database

    Procházková, Eliška; Kolmer, A.; Ilgen, J.; Schwab, M.; Kaltschnee, L.; Fredersdorf, M.; Schmidts, V.; Wende, R. C.; Schreiner, P. R.; Thiele, C. M.

    2016-01-01

    Roč. 55, č. 51 (2016), s. 15754-15759 ISSN 1433-7851 Institutional support: RVO:61388963 Keywords : conformational analysis * enantioselective acylations * NMR spectroscopy * pure shift NMR * RDCs Subject RIV: CC - Organic Chemistry Impact factor: 11.994, year: 2016

  7. Genetics Home Reference: medium-chain acyl-CoA dehydrogenase deficiency

    Science.gov (United States)

    ... Child Neuropsychol. 2009 Jan;15(1):8-20. doi: 10.1080/09297040701864570. Citation on PubMed Lang TF. Adult presentations of medium-chain acyl-CoA dehydrogenase deficiency (MCADD). J Inherit Metab Dis. 2009 Dec;32(6):675-83. doi: 10.1007/s10545-009-1202-0. Epub 2009 ...

  8. Structural organization of the human short-chain acyl-CoA dehydrogenase gene

    DEFF Research Database (Denmark)

    Corydon, M J; Andresen, B S; Bross, P

    1997-01-01

    Short-chain acyl-CoA dehydrogenase (SCAD) is a homotetrameric mitochondrial flavoenzyme that catalyzes the initial reaction in short-chain fatty acid beta-oxidation. Defects in the SCAD enzyme are associated with failure to thrive, often with neuromuscular dysfunction and elevated urinary excreti...

  9. Synthesis of acetylene alcohols of heterocyclic type and the acyl derivatives

    Directory of Open Access Journals (Sweden)

    Moldir Dyusebaeva

    2015-03-01

    Full Text Available A synthesis of potentially biologically active heterocyclic amino alcohols of acetylene (Piperidine and Morpholine under the conditions of Mannich reaction accomplished and received their acyl derivatives. Pharmacological activity (antibacterial and antispasmotic of synthesized compounds, also acute toxicological characteristics studied. The study showed that the combination of DMAE-4 has antispasmodic activity with low toxicity.

  10. N-acyl thioureas - selective ligands for complexing of heavy metals and noble metals

    International Nuclear Information System (INIS)

    Schuster, M.

    1992-01-01

    Acyl thioureas are complexing agents for heavy metals that are easily produced and very stable. Their favourable toxicological data make them particularly suitable for industrial applications, e.g. detoxification of metallic process solutions or solvent extraction of metals. (orig.) [de

  11. Experimental and theoretical rearrangement of N-acyl-2,2 ...

    Indian Academy of Sciences (India)

    Abstract. The acid isomerization of N-acyl-2,2-dimethylaziridines 1 in concentrated sulfuric acid at room temperature leads to oxazolines 2 but the neutral hydrolysis of 1 in pure water at room temperature leads to amidoalcohols 3. However, the use of aqueous solutions of H2SO4 at different concentrations at room tempera-.

  12. Acylated proteins in Borrelia hermsii, Borrelia parkeri, Borrelia anserina, and Borrelia coriaceae.

    OpenAIRE

    Sambri, V; Stefanelli, C; Rossoni, C; La Placa, M; Cevenini, R

    1993-01-01

    Borrelia hermsii, Borrelia parkeri, Borrelia anserina, and Borrelia coriaceae produced several lipoproteins identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography of bacteria grown in [3H]palmitate. Five major acylated proteins were demonstrated by sequential alkaline and acid hydrolysis. High-pressure liquid chromatography of isolated proteins confirmed that covalently bound radioactivity was represented by fatty acids.

  13. Triazole-containing N-acyl homoserine lactones targeting the quorum sensing system in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Hansen, Mette Reimert; Jakobsen, Tim H.; Bang, Claus Gunnar

    2015-01-01

    the pathogenesis and antibiotic tolerance of a bacterial biofilm. To identify the structural elements important for antagonistic or agonistic activity against the Pseudomonas aeruginosa LasR protein, we report the synthesis and screening of new triazole-containing mimics of natural N-acyl homoserine lactones...

  14. An Efficient and Green Procedure for the Preparation of Acylals from ...

    African Journals Online (AJOL)

    NJD

    Alum [KAl(SO4)2.12H2O] is an inexpensive, efficient, non-toxic and mild catalyst for the preparation of acylals from aromatic and heteroaryl aldehydes ... green synthetic solution by avoiding toxic catalysts and hazardous solvents. KEYWORDS .... In order to demonstrate the high selectivity of the procedure, we investigated ...

  15. Relevance of expanded neonatal screening of medium-chain acyl co-a dehydrogenase deficiency

    DEFF Research Database (Denmark)

    Couce, M L; Castiñeiras, D E; Moure, J D

    2011-01-01

    Neonatal screening of medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is of major importance due to the significant morbidity and mortality in undiagnosed patients. MCADD screening has been performed routinely in Galicia since July 2000, and until now 199,943 newborns have been screened. We...

  16. Recurrent Ventricular Tachycardia in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

    NARCIS (Netherlands)

    Bala, P.; Ferdinandusse, S.; Olpin, S. E.; Chetcuti, P.; Morris, A. A. M.

    2016-01-01

    We report a baby with medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency who presented on day 2 with poor feeding and lethargy. She was floppy with hypoglycaemia (1.8 mmol/l) and hyperammonaemia (182 μmol/l). Despite correction of these and a continuous intravenous infusion of glucose at

  17. The acyl-CoA binding protein is required for normal epidermal barrier function in mice

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Bek, Signe; Marcher, Ann-Britt

    2012-01-01

    The acyl-CoA binding protein (ACBP) is a 10 kDa intracellular protein expressed in all eukaryotic species. Mice with targeted disruption of Acbp (ACBP(-/-) mice) are viable and fertile but present a visible skin and fur phenotype characterized by greasy fur and development of alopecia and scaling...

  18. Cortical dynamics of figure-ground separation in response to 2D pictures and 3D scenes:How V2 combines border ownership, stereoscopic cues, and Gestalt grouping rules

    Directory of Open Access Journals (Sweden)

    Stephen eGrossberg

    2016-01-01

    Full Text Available The FACADE model, and its laminar cortical realization and extension in the 3D LAMINART model, have explained, simulated, and predicted many perceptual and neurobiological data about how the visual cortex carries out 3D vision and figure-ground perception, and how these cortical mechanisms enable 2D pictures to generate 3D percepts of occluding and occluded objects. In particular, these models have proposed how border ownership occurs, but have not yet explicitly explained the correlation between multiple properties of border ownership neurons in cortical area V2 that were reported in a remarkable series of neurophysiological experiments by von der Heydt and his colleagues; namely, border ownership, contrast preference, binocular stereoscopic information, selectivity for side-of-figure, Gestalt rules, and strength of attentional modulation, as well as the time course during which such properties arise. This article shows how, by combining 3D LAMINART properties that were discovered in two parallel streams of research, a unified explanation of these properties emerges. This explanation proposes, moreover, how these properties contribute to the generation of consciously seen 3D surfaces. The first research stream models how processes like 3D boundary grouping and surface filling-in interact in multiple stages within and between the V1 interblob – V2 interstripe – V4 cortical stream and the V1 blob – V2 thin stripe – V4 cortical stream, respectively. Of particular importance for understanding figure-ground separation is how these cortical interactions convert computationally complementary boundary and surface mechanisms into a consistent conscious percept, including the critical use of surface contour feedback signals from surface representations in V2 thin stripes to boundary representations in V2 interstripes. Remarkably, key figure-ground properties emerge from these feedback interactions. The second research stream shows how cells that

  19. The cyclopentyl group, as a small but bulky terminal group, allows rapid and efficient active transport.

    Science.gov (United States)

    Nishiyama, Junya; Makita, Yoshimasa; Kihara, Nobuhiro

    2015-01-02

    Secondary ammonium salts bearing a cyclopentyl terminal group rapidly formed pseudorotaxane with 1.5 equiv of DB24C8. Acylation of the pseudorotaxane with 50 equiv of benzoyl chloride in the presence of 50 equiv of triethylamine in toluene afforded rotaxane, the product of active transport, in 95% yield. The cyclopentyl group is small enough to allow rapid formation of pseudorotaxane, and bulky enough to facilitate the quantitative active transport by steric repulsion.

  20. Phosphazene membranes for gas separations

    Science.gov (United States)

    Stewart, Frederick F.; Harrup, Mason K.; Orme, Christopher J.; Luther, Thomas A.

    2006-07-11

    A polyphosphazene having a glass transition temperature ("T.sub.g") of approximately -20.degree. C. or less. The polyphosphazene has at least one pendant group attached to a backbone of the polyphosphazene, wherein the pendant group has no halogen atoms. In addition, no aromatic groups are attached to an oxygen atom that is bound to a phosphorus atom of the backbone. The polyphosphazene may have a T.sub.g ranging from approximately -100.degree. C. to approximately -20.degree. C. The polyphosphazene may be selected from the group consisting of poly[bis-3-phenyl-1-propoxy)phosphazene], poly[bis-(2-phenyl-1-ethoxy)phosphazene], poly[bis-(dodecanoxypolyethoxy)-phosphazene], and poly[bis-(2-(2-(2-.omega.-undecylenyloxyethoxy)ethoxy)ethoxy)phosphazene]- . The polyphosphazene may be used in a separation membrane to selectively separate individual gases from a gas mixture, such as to separate polar gases from nonpolar gases in the gas mixture.

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

    Science.gov (United States)

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

    2014-12-01

    Probenecid, a widely used uricosuric agent, is mainly metabolized to probenecid acyl glucuronide (PRAG), which is considered a causal substance of severe allergic or anaphylactoid reactions. PRAG can be hydrolyzed (deglucuronidated) to probenecid. The purpose of this study was to identify enzymes responsible for probenecid acyl glucuronidation and PRAG deglucuronidation in human livers and to examine the effect of deglucuronidation in PRAG formation. In human liver homogenates (HLHs), the intrinsic clearance (CLint) of PRAG deglucuronidation was much greater (497-fold) than that of probenecid acyl glucuronidation. Evaluation of PRAG formation by recombinant UDP-glucuronosyltransferase (UGT) isoforms and an inhibition study using HLHs as an enzyme source demonstrated that multiple UGT isoforms, including UGT1A1, UGT1A9, and UGT2B7, catalyzed probenecid acyl glucuronidation. We found that recombinant α/β hydrolase domain containing 10 (ABHD10) substantially catalyzed PRAG deglucuronidation activity, whereas carboxylesterases did not. Similar inhibitory patterns by chemicals between HLHs and recombinant ABHD10 supported the major contribution of ABHD10 to PRAG deglucuronidation in human liver. Interestingly, it was demonstrated that the CLint value of probenecid acyl glucuronidation in HLHs was increased by 1.7-fold in the presence of phenylmethylsulfonyl fluoride, which potently inhibited ABHD10 activity. In conclusion, we found that PRAG deglucuronidation catalyzed by ABHD10 suppressively regulates PRAG formation via multiple UGT enzymes in human liver. The balance of activities by these enzymes is important for the formation of PRAG, which may be associated with the adverse reactions observed after probenecid administration. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

  2. A rare disease-associated mutation in the medium-chain acyl-CoA dehydrogenase (MCAD) gene changes a conserved arginine, previously shown to be functionally essential in short-chain acyl-CoA dehydrogenase (SCAD)

    DEFF Research Database (Denmark)

    Andresen, B S; Bross, P; Jensen, T G

    1993-01-01

    Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a serious and potentially fatal inherited defect in the beta-oxidation of fatty acids. Approximately 80% of patients with MCAD deficiency are homozygous for a single disease-causing mutation (G985). The remaining patients (except for a few ......-chain acyl-CoA dehydrogenase (SCAD) gene of a patient with SCAD deficiency, suggesting that the conserved arginine is crucial for formation of active enzyme in the straight-chain acyl-CoA dehydrogenases....

  3. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Separation Anxiety KidsHealth / For Parents / Separation Anxiety What's in this ... both of you get through it. About Separation Anxiety Babies adapt pretty well to other caregivers. Parents ...

  4. Separation and structural analysis of some saponins from Quillaja saponaria Molina.

    Science.gov (United States)

    Nyberg, N T; Kenne, L; Rönnberg, B; Sundquist, B G

    2000-01-12

    A fraction of saponins from Quillaja saponaria Molina, QH-B, was fractionated by consecutive separations on three different reverse-phase HPLC systems. Eight compounds were isolated and the structures of these were elucidated mainly by sugar analysis and NMR spectroscopy. The structures consisted of a quillaic acid substituted with two different trisaccharides at C-3, beta-D-Galp-(1-->2)-[alpha-L-Rhap-(1-->3)]-beta-D-GlcpA and beta-D-Galp-(1-->2)-[beta-D-Xylp-(1-->3)]-beta-D-GlcpA, and a tetra- or pentasaccharide at C-28, beta-D-Xylp-(1-->4)-[beta-D-Glcp-(1-->3)]-alpha-L-Rhap-(1--> 2)-beta-D-Fucp and beta-D-Apif-(1-->3)-beta-D-Xylp-(1-->4)-[beta-D-Glcp-(1-->3) ]-alpha-L- Rhap-(1-->2)-beta-D-Fucp. These compounds were further substituted with an acyl group either at O-3 or O-4 of the fucose residue, which is the sugar linked to C-28 of the quillaic acid.

  5. Advanced isotope separation

    International Nuclear Information System (INIS)

    1982-01-01

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  6. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...... overlap. We demonstrate, via a range of examples, how fictional separation logic can be used to reason locally and modularly about mutable abstract data types, possibly implemented using sophisticated sharing. Fictional separation logic is defined on top of standard separation logic, and both the meta...

  7. Crystallization and preliminary X-ray crystallographic studies of enoyl-acyl carrier protein reductase (FabI) from Psuedomonas aeruginosa

    International Nuclear Information System (INIS)

    Lee, Jeong Hye; Park, Ae Kyung; Chi, Young Min; Moon, Jin Ho; Lee, Ki Seog

    2011-01-01

    Enoyl-acyl carrier protein reductase (FabI) from P. aeruginosa was purified and crystallized. FabI was also cocrystallized with the inhibitor triclosan and the cofactor NADH. Crystals of native and complexed FabI diffracted to resolutions of 2.6 and 1.8 Å, respectively. During fatty-acid biosynthesis, enoyl-acyl carrier protein (enoyl-ACP) reductase catalyzes the reduction of trans-2-enoyl-ACP to fully saturated acyl-ACP via the ubiquitous fatty-acid synthase system. NADH-dependent enoyl-ACP reductase (FabI) from Pseudomonas aeruginosa has been purified and crystallized as an apoenzyme and in a complex form with NADH and triclosan. Triclosan is an inhibitor of FabI and forms a stable ternary complex in the presence of NADH. The crystals of native and complexed FabI diffracted to resolutions of 2.6 and 1.8 Å, respectively. The crystals both belonged to space group P2 1 , with unit-cell parameters a = 117.32, b = 155.844, c = 129.448 Å, β = 111.061° for the native enzyme and a = 64.784, b = 107.573, c = 73.517 Å, β = 116.162° for the complex. Preliminary molecular replacement further confirmed the presence of four tetramers of native FabI and one tetramer of the complex in the asymmetric unit, corresponding to Matthews coefficients (V M ) of 2.46 and 2.05 Å 3 Da −1 and solvent contents of 50.1 and 40.1%, respectively

  8. Plasma stability-dependent circulation of acyl glucuronide metabolites in humans: how circulating metabolite profiles of muraglitazar and peliglitazar can lead to misleading risk assessment.

    Science.gov (United States)

    Zhang, Donglu; Raghavan, Nirmala; Wang, Lifei; Xue, Yongjun; Obermeier, Mary; Chen, Stephanie; Tao, Shiwei; Zhang, Hao; Cheng, Peter T; Li, Wenying; Ramanathan, Ragu; Yang, Zheng; Humphreys, W Griffith

    2011-01-01

    Muraglitazar and peliglitazar, two structural analogs differing by a methyl group, are dual peroxisome proliferator-activated receptor-α/γ activators. Both compounds were extensively metabolized in humans through acyl glucuronidation to form 1-O-β-acyl glucuronide (AG) metabolites as the major drug-related components in bile, representing at least 15 to 16% of the dose after oral administration. Peliglitazar AG was the major circulating metabolite, whereas muraglitazar AG was a very minor circulating metabolite in humans. Peliglitazar AG circulated at lower concentrations in animal species than in humans. Both compounds had a similar glucuronidation rate in UDP-glucuronic acid-fortified human liver microsomal incubations and a similar metabolism rate in human hepatocytes. Muraglitazar AG and peliglitazar AG were chemically synthesized and found to be similarly oxidized through hydroxylation and O-demethylation in NADPH-fortified human liver microsomal incubations. Peliglitazar AG had a greater stability than muraglitazar AG in incubations in buffer, rat, or human plasma (pH 7.4). Incubations of muraglitazar AG or peliglitazar AG in plasma produced more aglycon than acyl migration products compared with incubations in the buffer. These data suggested that the difference in plasma stability, not differences in intrinsic formation, direct excretion, or further oxidation of muraglitazar AG or peliglitazar AG, contributed to the observed difference in the circulation of these AG metabolites in humans. The study demonstrated the difficulty in doing risk assessment based on metabolite exposure in plasma because the more reactive muraglitazar AG would not have triggered a threshold of concern based on the recent U.S. Food and Drug Administration guidance on Metabolites in Safety Testing, whereas the more stable peliglitazar AG would have.

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  10. Stable isotope separation

    International Nuclear Information System (INIS)

    Botter, F.; Molinari, Ph.; Dirian, G.

    1964-01-01

    Pure deuterium has been separated from gaseous mixtures of hydrogen and deuterium by band displacement chromatography, using columns of palladium on a support. The best results were obtained with columns of Pd on sintered α alumina. With a column of this type, of total capacity about 2 liters, a preparative apparatus of low dead volume has been built which produces 1 liter of pure D 2 from a 50 p. 100 D 2 , 50 p. 100 100 H 2 mixture in about 12 minutes. As a first approximation chromatography is likened theoretically to counter current fractionation, neglecting superficial resistance to the exchange. and also longitudinal diffusions. The number of theoretical plates required necessary for a certain enrichment of the gas phase is determined graphically or by calculation, enabling comparisons to be made between the efficiencies of columns containing different amounts of palladium. Thermal Diffusion: For the separation of hydrogen isotopes a thermal diffusion installation, made of stainless steel and entirely tele-commanded has been constructed. The separation cascade is made up of two identical pairs of hot wire columns. Each pair can work separately or they may be connected by a thermosyphon. The temperature of the hot wire is kept at around 1000 deg C by direct current. With this installation, hydrogen samples with a deuterium content lower than o,5 ppm were obtained from a gas originally containing 32 ppm. It was thus possible to prepare tritium of 99,3 p. 100 concentration from gas with an initial content of 6 p. 100. For quantitative separation of xenon enriched five time in 124 Xe by thermal diffusion, two identical cascades were constructed, each consisting of 5 columns, working in parallel and the two being connected by thermosyphon or by a capillary tube linked to a thermal gas oscillation. The central tungsten wire is heated to 1200 deg C. The columns are grouped like cluster of a heat exchanger, in shell of 30 cm diameter through which cooling water

  11. Effects of riboflavin deficiency and clofibrate treatment on the five acyl-CoA dehydrogenases in rat liver mitochondria.

    OpenAIRE

    Veitch, K; Draye, J P; Van Hoof, F; Sherratt, H S

    1988-01-01

    Rats were maintained on a riboflavin-deficient diet or on a diet containing clofibrate (0.5%, w/w). The activities of the mitochondrial FAD-dependent straight-chain acyl-CoA dehydrogenases (butyryl-CoA, octanoyl-CoA and palmitoyl-CoA) and the branched-chain acyl-CoA dehydrogenases (isovaleryl-CoA and isobutyryl-CoA) involved in the degradation of branched-chain acyl-CoA esters derived from branched-chain amino acids were assayed in liver mitochondrial extracts prepared in the absence and pres...

  12. Asymmetric Chemoenzymatic Reductive Acylation of Ketones by a Combined Iron-Catalyzed Hydrogenation-Racemization and Enzymatic Resolution Cascade

    KAUST Repository

    El-Sepelgy, Osama

    2017-02-28

    A general and practical process for the conversion of prochiral ketones into the corresponding chiral acetates has been realized. An iron carbonyl complex is reported to catalyze the hydrogenation-dehydrogenation-hydrogenation of prochiral ketones. By merging the iron-catalyzed redox reactions with enantioselective enzymatic acylations a wide range of benzylic, aliphatic and (hetero)aromatic ketones, as well as diketones, were reductively acylated. The corresponding products were isolated with high yields and enantioselectivities. The use of an iron catalyst together with molecular hydrogen as the hydrogen donor and readily available ethyl acetate as acyl donor make this cascade process highly interesting in terms of both economic value and environmental credentials.

  13. Glu-Trp-ONa or its acylated analogue (R-Glu-Trp-ONa) administration enhances the wound healing in the model of chronic skin wounds in rabbits

    Science.gov (United States)

    Shevtsov, Maxim A; Smagina, Larisa V; Kudriavtceva, Tatiana A; Petlenko, Sergey V; Voronkina, Irina V

    2015-01-01

    The management of chronic skin wounds represents a major therapeutic challenge. The synthesized dipeptide (Glu-Trp-ONa) and its acylated analogue (R-Glu-Trp-ONa) were assessed in the model of nonhealing dermal wounds in rabbits in relation to their healing properties in wound closure. Following wound modeling, the rabbits received a course of intraperitoneal injections of Glu-Trp-ONa or R-Glu-Trp-ONa. Phosphate-buffered saline and Solcoseryl® were applied as negative and positive control agents, respectively. An injection of Glu-Trp-ONa and R-Glu-Trp-ONa decreased the period of wound healing in animals in comparison to the control and Solcoseryl-treated groups. Acylation of Glu-Trp-ONa proved to be beneficial as related to the healing properties of the dipeptide. Subsequent zymography analyses showed that the applied peptides decreased the proteolytic activity of matrix metalloproteinases MMP-9, MMP-8, and MMP-2 in the early inflammatory phase and reversely increased the activity of MMP-9, MMP-8, and MMP-1 in the remodeling phase. Histological analyses of the wound sections (hematoxylin–eosin, Mallory’s staining) confirmed the enhanced formation of granulation tissue and re-epithelialization in the experimental groups. By administering the peptides, wound closures increased significantly through the modulation of the MMPs’ activity, indicating their role in wound healing. PMID:25848208

  14. Cortical Dynamics of Figure-Ground Separation in Response to 2D Pictures and 3D Scenes: How V2 Combines Border Ownership, Stereoscopic Cues, and Gestalt Grouping Rules.

    Science.gov (United States)

    Grossberg, Stephen

    2015-01-01

    The FACADE model, and its laminar cortical realization and extension in the 3D LAMINART model, have explained, simulated, and predicted many perceptual and neurobiological data about how the visual cortex carries out 3D vision and figure-ground perception, and how these cortical mechanisms enable 2D pictures to generate 3D percepts of occluding and occluded objects. In particular, these models have proposed how border ownership occurs, but have not yet explicitly explained the correlation between multiple properties of border ownership neurons in cortical area V2 that were reported in a remarkable series of neurophysiological experiments by von der Heydt and his colleagues; namely, border ownership, contrast preference, binocular stereoscopic information, selectivity for side-of-figure, Gestalt rules, and strength of attentional modulation, as well as the time course during which such properties arise. This article shows how, by combining 3D LAMINART properties that were discovered in two parallel streams of research, a unified explanation of these properties emerges. This explanation proposes, moreover, how these properties contribute to the generation of consciously seen 3D surfaces. The first research stream models how processes like 3D boundary grouping and surface filling-in interact in multiple stages within and between the V1 interblob-V2 interstripe-V4 cortical stream and the V1 blob-V2 thin stripe-V4 cortical stream, respectively. Of particular importance for understanding figure-ground separation is how these cortical interactions convert computationally complementary boundary and surface mechanisms into a consistent conscious percept, including the critical use of surface contour feedback signals from surface representations in V2 thin stripes to boundary representations in V2 interstripes. Remarkably, key figure-ground properties emerge from these feedback interactions. The second research stream shows how cells that compute absolute disparity in

  15. Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography-Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase.

    Science.gov (United States)

    Jumaah, Firas; Jędrkiewicz, Renata; Gromadzka, Justyna; Namieśnik, Jacek; Essén, Sofia; Turner, Charlotta; Sandahl, Margareta

    2017-09-20

    This study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO 2 ) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO 2 without addition of cosolvent in ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono- and diesters are separated on a 2-picolylamine column in less than 12 min. The presence and position of a hydroxyl group in the structure, the number of unsaturated bonds, and the acyl chain length play a significant role in the separation of MCPD esters. The flow rate, backpressure, and column oven temperature, which affect the density of the mobile phase, were shown to have a substantial impact on retention, efficiency, and selectivity. The developed method was successfully applied for the determination of MCPD esters in refined oils and showed a close to excellent green analysis score using the Analytical Eco-Scale.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-07

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

  18. Structural organization of the human short-chain acyl-CoA dehydrogenase gene

    DEFF Research Database (Denmark)

    Corydon, M J; Andresen, B S; Bross, P

    1997-01-01

    Short-chain acyl-CoA dehydrogenase (SCAD) is a homotetrameric mitochondrial flavoenzyme that catalyzes the initial reaction in short-chain fatty acid beta-oxidation. Defects in the SCAD enzyme are associated with failure to thrive, often with neuromuscular dysfunction and elevated urinary excreti....... The evolutionary relationship between SCAD and five other members of the acyl-CoA dehydrogenase family was investigated by two independent approaches that gave similar phylogenetic trees....... shown to be associated with ethylmalonic aciduria. From analysis of 18 unrelated Danish families, we show that the four SCAD gene polymorphisms constitute five allelic variants of the SCAD gene, and that the 625A variant together with the less frequent variant form of the three other polymorphisms (321C...

  19. Clean-chemistry synthesis of 2-tetralones in a single-stage acylation-cycloalkylation process.

    Science.gov (United States)

    Gray, A D; Smyth, T P

    2001-10-19

    The preparation of substituted-2-tetralones by direct reaction of a 1-alkene with a substituted phenylacetic acid in a reaction system of trifluoroacetic anhydride (TFAA) and phosphoric acid is described. This single-stage process involves in situ formation of a mixed anhydride of the phenylacetic acid and acylation of the alkene by this species followed by cycloalkylation of the aromatic ring. This is a cleaner approach to the synthesis of 2-tetralones compared to Friedel-Crafts aliphatic acylation-cycloalkylation in that use of thionyl chloride, aluminum trichloride, and a chlorinated hydrocarbon solvent is eliminated. In addition, the atom efficiency is augmented by recovery of the spent TFAA as trifluoroacetic acid (TFA) and conversion of this back to TFAA by dehydration.

  20. Synthesis 1-Acyl-3-(2'-aminophenyl thioureas as Anti-Intestinal Nematode Prodrugs

    Directory of Open Access Journals (Sweden)

    Li-Li Xu

    2010-10-01

    Full Text Available A series of 1-acyl-3-(2'-aminophenyl thiourea derivatives were designed and synthesized. The structures of all the newly synthesized compounds were identified by IR, elemental analysis, 1H-NMR and 13C-NMR. Their anti-intestinal nematode activities against Nippostrongylus brazilliensis were evaluated in rats by an oral route. Among these compounds, at concentrations of 10 mg/kg of rat, compound (1-(2'-furanylacyl-3- (2'-aminophenyl thiourea (5h produced the highest activity with 89.4% deparasitization. The present work suggests that 1-acyl-3-(2'-aminophenyl thiourea derivatives may become useful  lead compounds for anti-intestinal nematode treatment.

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

    DEFF Research Database (Denmark)

    Tanaka, K; Yokota, I; Coates, P M

    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...... of 172 unrelated patients each representing an independent pedigree, a total of 8 different mutations have been identified. Among them, a single prevalent mutation, 985A-->G, was found in 90% of 344 variant alleles. 985A-->G causes glutamate substitution for lysine-304 in the mature MCAD subunit, 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. Age dependent accumulation of N-acyl-ethanolamine phospholipids in ischemic rat brain

    DEFF Research Database (Denmark)

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

    2000-01-01

    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...... brains NAPE accumulation could not be detected (detection limit 0.09 %)]; and 2) this age pattern of accumulation can be explained by a combination of the decreased activity of N- acyltransferase and the increased activity of NAPE-PLD during development. These results point out that it would......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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-01

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

  4. Transcriptome analysis of acyl-homoserine lactone-based quorum sensing regulation in Yersinia pestis [corrected].

    Directory of Open Access Journals (Sweden)

    Christopher N LaRock

    Full Text Available The etiologic agent of bubonic plague, Yersinia pestis, senses self-produced, secreted chemical signals in a process named quorum sensing. Though the closely related enteric pathogen Y. pseudotuberculosis uses quorum sensing system to regulate motility, the role of quorum sensing in Y. pestis has been unclear. In this study we performed transcriptional profiling experiments to identify Y. pestis quorum sensing regulated functions. Our analysis revealed that acyl-homoserine lactone-based quorum sensing controls the expression of several metabolic functions. Maltose fermentation and the glyoxylate bypass are induced by acyl-homoserine lactone signaling. This effect was observed at 30°C, indicating a potential role for quorum sensing regulation of metabolism at temperatures below the normal mammalian temperature. It is proposed that utilization of alternative carbon sources may enhance growth and/or survival during prolonged periods in natural habitats with limited nutrient sources, contributing to maintenance of plague in nature.

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

    DEFF Research Database (Denmark)

    Hu, Liping; Deeney, Jude T; Nolan, Christopher J

    2005-01-01

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

  6. Effects of Nanoparticle Morphology and Acyl Chain Length on Spontaneous Lipid Transfer Rates.

    Science.gov (United States)

    Xia, Yan; Li, Ming; Charubin, Kamil; Liu, Ying; Heberle, Frederick A; Katsaras, John; Jing, Benxin; Zhu, Yingxi; Nieh, Mu-Ping

    2015-12-01

    We report on studies of lipid transfer rates between different morphology nanoparticles and lipids with different length acyl chains. The lipid transfer rate of dimyristoylphosphatidylcholine (di-C14, DMPC) in discoidal "bicelles" (0.156 h(-1)) is 2 orders of magnitude greater than that of DMPC vesicles (ULVs) (1.1 × 10(-3) h(-1)). For both bicellar and ULV morphologies, increasing the acyl chain length by two carbons [going from di-C14 DMPC to di-C16, dipalmitoylphosphatidylcholine (DPPC)] causes lipid transfer rates to decrease by more than 2 orders of magnitude. Results from small angle neutron scattering (SANS), differential scanning calorimetry (DSC), and fluorescence correlation spectroscopy (FCS) are in good agreement. The present studies highlight the importance of lipid dynamic processes taking place in different morphology biomimetic membranes.

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

    DEFF Research Database (Denmark)

    Mandrup, S; Hummel, R; Ravn, S

    1992-01-01

    modulator of the GABAA receptor in brain membranes. ACBP/DBI, or proteolytically derived polypeptides of ACBP/DBI, have also been implicated in the control of steroidogenesis in mitochondria and glucose-stimulated insulin secretion. Thus, it appears that ACBP/DBI is a remarkable, versatile protein. Now we......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....... There is a 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...

  8. Effect of the acylation of TEAD4 on its interaction with co-activators YAP and TAZ.

    Science.gov (United States)

    Mesrouze, Yannick; Meyerhofer, Marco; Bokhovchuk, Fedir; Fontana, Patrizia; Zimmermann, Catherine; Martin, Typhaine; Delaunay, Clara; Izaac, Aude; Kallen, Joerg; Schmelzle, Tobias; Erdmann, Dirk; Chène, Patrick

    2017-12-01

    The Hippo pathway is deregulated in various cancers, and the discovery of molecules that modulate this pathway may open new therapeutic avenues in oncology. TEA/ATTS domain (TEAD) transcription factors are the most distal elements of the Hippo pathway and their transcriptional activity is regulated by the Yes-associated protein (YAP). Amongst the various possibilities for targeting this pathway, inhibition of the YAP:TEAD interaction is an attractive strategy. It has been shown recently that TEAD proteins are covalently linked via a conserved cysteine to a fatty acid molecule (palmitate) that binds to a deep hydrophobic cavity present in these proteins. This acylation of TEAD seems to be required for efficient binding to YAP, and understanding how it modulates the YAP:TEAD interaction may provide useful information on the regulation of TEAD function. In this report we have studied the effect of TEAD4 acylation on its interaction with YAP and the other co-activator transcriptional co-activator with PDZ-binding motif (TAZ). We show in our biochemical and cellular assays that YAP and TAZ bind in a similar manner to acylated and non-acylated TEAD4. This indicates that TEAD4 acylation is not a prerequisite for its interaction with YAP or TAZ. However, we observed that TEAD4 acylation significantly enhances its stability, suggesting that it may help this transcription factor to acquire and/or maintain its active conformation. © 2017 The Protein Society.

  9. Des-acyl ghrelin prevents heatstroke-like symptoms in rats exposed to high temperature and high humidity.

    Science.gov (United States)

    Inoue, Yoshiyuki; Hayashi, Yujiro; Kangawa, Kenji; Suzuki, Yoshihiro; Murakami, Noboru; Nakahara, Keiko

    2016-02-26

    We have shown previously that des-acyl ghrelin decreases body temperature in rats through activation of the parasympathetic nervous system. Here we investigated whether des-acyl ghrelin ameliorates heatstroke in rats exposed to high temperature. Peripheral administration of des-acyl ghrelin significantly attenuated hyperthermia induced by exposure to high-temperature (35°C) together with high humidity (70-80%). Although biochemical analysis revealed that exposure to high temperature significantly increased hematocrit and the serum levels of aspartate amino transferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN), creatinine and electrolytes (Na(+), K(+), Cl(-)), most of these heatstroke-associated reactions were significantly reduced by treatment with des-acyl ghrelin. The level of des-acyl ghrelin in plasma was also found to be significantly increased under high-temperature conditions. These results suggest that des-acyl ghrelin could be useful for preventing heatstroke under high temperature condition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Soares, M.G.C.B.

    1976-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mingzhong Cai

    2009-09-01

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

  12. Production and Transport of Gaseous18F-Synthons:18F-Acyl Fluorides.

    Science.gov (United States)

    Jiang, Huailei; DiMagno, Stephen G; DeGrado, Timothy R

    2015-12-01

    Fluorine-18 ( 18 F, T 1/2 =109.7 min) is a positron-emitting isotope that has found extensive application as a radiolabel for positron emission tomography (PET). Although gaseous 11 C-CO 2 and 11 C-CH 4 are practically transported from cyclotron to radiochemistry processes, 18 F-fluoride is routinely transported in aqueous solution because it is commonly produced by proton irradiation of 18 O-enriched water. In most cases, subsequent dry-down steps are necessary to prepare reactive 18 F-fluoride for radiofluorination. In this work, a simple module was designed to generate gaseous 18 F-acyl fluorides from aqueous 18 F-fluoride solution by solid phase 18 F-radiofluorination of acyl anhydride. The gaseous 18 F-acyl fluorides were purified through a column containing Porapak Q/Na 2 SO 4 , resulting in high yields (>86%), purities (>99%) and specific activities (>1200 GBq/μmol). Prototypic 18 F-acetyl fluoride ( 18 F-AcF) was readily transported through 15 m of 0.8 mm ID polypropylene tubing with low (0.64 ± 0.12 %) adsorption to the tubing. Following dissolution of 18 F-AcF in solvent containing base, highly reactive 18 F-flouride was generated immediately and used directly for 18 F-labeling reactions. These data indicate that 18 F-acyl fluorides represent a new paradigm for preparation and transport of anhydrous, reactive 18 F-fluoride for radiofluorinations.

  13. Acyl chloride carbon insertion into dicarbaborane cages - new route to tricarbollide cages

    Czech Academy of Sciences Publication Activity Database

    Štíbr, Bohumil

    2015-01-01

    Roč. 87, č. 2 (2015), s. 135-142 ISSN 0033-4545. [IMEBORON/15./. Praha, 24.08.2014-28.08.2014] R&D Projects: GA ČR(CZ) GAP207/11/0705 Institutional support: RVO:61388980 Keywords : acyl chlorides * carbon insertion * carboranes * IMEBORON-XV * metallatricarbollides * tricarbollides Subject RIV: CA - Inorganic Chemistry Impact factor: 2.615, year: 2015

  14. Accumulation of medium-chain, saturated fatty acyl moieties in seed oils of transgenic Camelina sativa.

    Directory of Open Access Journals (Sweden)

    Zhaohui Hu

    Full Text Available With its high seed oil content, the mustard family plant Camelina sativa has gained attention as a potential biofuel source. As a bioenergy crop, camelina has many advantages. It grows on marginal land with low demand for water and fertilizer, has a relatively short life cycle, and is stress tolerant. As most other crop seed oils, camelina seed triacylglycerols (TAGs consist of mostly long, unsaturated fatty acyl moieties, which is not desirable for biofuel processing. In our efforts to produce shorter, saturated chain fatty acyl moieties in camelina seed oil for conversion to jet fuel, a 12:0-acyl-carrier thioesterase gene, UcFATB1, from California bay (Umbellularia californica Nutt. was expressed in camelina seeds. Up to 40% of short chain laurate (C12:0 and myristate (C14:0 were present in TAGs of the seed oil of the transgenics. The total oil content and germination rate of the transgenic seeds were not affected. Analysis of positions of these two fatty acyl moieties in TAGs indicated that they were present at the sn-1 and sn-3 positions, but not sn-2, on the TAGs. Suppression of the camelina KASII genes by RNAi constructs led to higher accumulation of palmitate (C16:0, from 7.5% up to 28.5%, and further reduction of longer, unsaturated fatty acids in seed TAGs. Co-transformation of camelina with both constructs resulted in enhanced accumulation of all three medium-chain, saturated fatty acids in camelina seed oils. Our results show that a California bay gene can be successfully used to modify the oil composition in camelina seed and present a new biological alternative for jet fuel production.

  15. Two new acylated flavonol glycosides from Mimosa pigra L. leaves sub-family Mimosoideae

    Directory of Open Access Journals (Sweden)

    Chinedu J. Okonkwo

    2016-12-01

    Conclusion: Myricetin, quercetin and their glycoside derivatives are strong antioxidants; and elicit cytotoxic effect on human cancer cell lines among other pharmacological activities. The isolation of acylated flavonoids in M. pigra provided an important insight on the evolutionary trend of the medicinal plant. While the dominance of flavonols, may account for the various ethnomedicinal uses of the herb and the mechanism and mode of its confirmed pharmacological actions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  17. Acquired multiple Acyl-CoA dehydrogenase deficiency in 10 horses with atypical myopathy.

    Science.gov (United States)

    Westermann, C M; Dorland, L; Votion, D M; de Sain-van der Velden, M G M; Wijnberg, I D; Wanders, R J A; Spliet, W G M; Testerink, N; Berger, R; Ruiter, J P N; van der Kolk, J H

    2008-05-01

    The aim of the current study was to assess lipid metabolism in horses with atypical myopathy. Urine samples from 10 cases were subjected to analysis of organic acids, glycine conjugates, and acylcarnitines revealing increased mean excretion of lactic acid, ethylmalonic acid, 2-methylsuccinic acid, butyrylglycine, (iso)valerylglycine, hexanoylglycine, free carnitine, C2-, C3-, C4-, C5-, C6-, C8-, C8:1-, C10:1-, and C10:2-carnitine as compared with 15 control horses (12 healthy and three with acute myopathy due to other causes). Analysis of plasma revealed similar results for these predominantly short-chain acylcarnitines. Furthermore, measurement of dehydrogenase activities in lateral vastus muscle from one horse with atypical myopathy indeed showed deficiencies of short-chain acyl-CoA dehydrogenase (0.66 as compared with 2.27 and 2.48 in two controls), medium-chain acyl-CoA dehydrogenase (0.36 as compared with 4.31 and 4.82 in two controls) and isovaleryl-CoA dehydrogenase (0.74 as compared with 1.43 and 1.61 nmol min(-1) mg(-1) in two controls). A deficiency of several mitochondrial dehydrogenases that utilize flavin adenine dinucleotide as cofactor including the acyl-CoA dehydrogenases of fatty acid beta-oxidation, and enzymes that degrade the CoA-esters of glutaric acid, isovaleric acid, 2-methylbutyric acid, isobutyric acid, and sarcosine was suspected in 10 out of 10 cases as the possible etiology for a highly fatal and prevalent toxic equine muscle disease similar to the combined metabolic derangements seen in human multiple acyl-CoA dehydrogenase deficiency also known as glutaric acidemia type II.

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

    International Nuclear Information System (INIS)

    Friedmann, P.S.; Wren, F.E.; Matthews, J.N.

    1990-01-01

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

  19. A Scalable Method for Regioselective 3-Acylation of 2-Substituted Indoles under Basic Conditions

    DEFF Research Database (Denmark)

    Johansson, Karl Henrik; Urruticoechea, Andoni; Larsen, Inna

    2015-01-01

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

  20. Acyl-CoA binding protein is an essential protein in mammalian cell lines

    DEFF Research Database (Denmark)

    Knudsen, Jens; Færgeman, Nils J.

    2002-01-01

    In the present work, small interference RNA was used to knock-down acyl-CoA binding protein (ACBP) in HeLa, HepG2 and Chang cells. Transfection with ACBP-specific siRNA stopped growth, detached cells from the growth surface and blocked thymidine and acetate incorporation. The results show...... that depletion of ACBP in mammalian cells results in lethality, suggesting that ACBP is an essential protein....

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

    Energy Technology Data Exchange (ETDEWEB)

    Ohlrogge, J.B.

    1989-01-01

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

  2. Acyl-CoA thioesterase-2 facilitates mitochondrial fatty acid oxidation in the liver[S

    Science.gov (United States)

    Moffat, Cynthia; Bhatia, Lavesh; Nguyen, Teresa; Lynch, Peter; Wang, Miao; Wang, Dongning; Ilkayeva, Olga R.; Han, Xianlin; Hirschey, Matthew D.; Claypool, Steven M.; Seifert, Erin L.

    2014-01-01

    Acyl-CoA thioesterase (Acot)2 localizes to the mitochondrial matrix and hydrolyses long-chain fatty acyl-CoA into free FA and CoASH. Acot2 is expressed in highly oxi­dative tissues and is poised to modulate mitochondrial FA oxidation (FAO), yet its biological role is unknown. Using a model of adenoviral Acot2 overexpression in mouse liver (Ad-Acot2), we show that Acot2 increases the utilization of FA substrate during the daytime in ad libitum-fed mice, but the nighttime switch to carbohydrate oxidation is similar to control mice. In further support of elevated FAO in Acot2 liver, daytime serum ketones were higher in Ad-Acot2 mice, and overnight fasting led to minimal hepatic steatosis as compared with control mice. In liver mitochondria from Ad-Acot2 mice, phosphorylating O2 consumption was higher with lipid substrate, but not with nonlipid substrate. This increase depended on whether FA could be activated on the outer mitochondrial membrane, suggesting that the FA released by Acot2 could be effluxed from mitochondria then taken back up again for oxidation. This circuit would prevent the build-up of inhibitory long-chain fatty acyl-CoA esters. Altogether, our findings indicate that Acot2 can enhance FAO, possibly by mitigating the accumulation of FAO intermediates within the mitochondrial matrix. PMID:25114170

  3. Anorexia in hemodialysis patients: the possible role of des-acyl ghrelin.

    Science.gov (United States)

    Muscaritoli, Maurizio; Molfino, Alessio; Chiappini, Maria Grazia; Laviano, Alessandro; Ammann, Thomas; Spinsanti, Paola; Melchiorri, Daniela; Inui, Akio; Alegiani, Filippo; Rossi Fanelli, Filippo

    2007-01-01

    Anorexia is frequently found in end-stage renal disease and is a reliable predictor of morbidity and mortality in hemodialysis (HD) patients. The pathogenesis of anorexia is complex and the appetite-modulating hormone ghrelin could be involved. Two forms of circulating ghrelin have been described: acylated ghrelin (anorexic, and 20 patients (59%) non-anorexic. Energy intake (kcal/day) was significantly lower in anorexic than in non-anorexic patients (1,682 +/- 241 vs. 1,972.50 +/- 490; p anorexic than in non-anorexic patients (65.8 +/- 4.4 vs. 70.9 +/- 8.7; p = 0.05). Plasma des-acyl ghrelin levels (fmol/ml) were significantly higher in HD patients than in controls (214.88 +/- 154.24 vs. 128.93 +/- 51.07; p anorexic HD patients than in non-anorexic (301.7 +/- 162.4 vs. 159.1 +/- 115.5; p < 0.01). Anorexia is highly prevalent among HD patients and des-acyl ghrelin could be involved in its pathogenesis. Copyright 2007 S. Karger AG, Basel.

  4. Cholesteryl ester acyl oxidation and remodeling in murine macrophages: formation of oxidized phosphatidylcholine[S

    Science.gov (United States)

    Hutchins, Patrick M.; Murphy, Robert C.

    2012-01-01

    Cholesterol is an essential component of eukaryotic cell membranes, regulating fluidity and permeability of the bilayer. Outside the membrane, cholesterol is esterified to fatty acids forming cholesterol esters (CEs). Metabolism of CEs is characterized by recurrent hydrolysis and esterification as part of the CE cycle; however, since recombinant 15-lipoxygenase (15-LO) was shown to oxidize cholesteryl linoleate of LDL, there has been interest in CE oxidation, particularly in the context atherogenesis. Studies of oxidized CE (oxCE) metabolism have focused on hydrolysis and subsequent reverse cholesterol transport with little emphasis on the fate the newly released oxidized fatty acyl component. Here, using mass spectrometry to analyze lipid oxidation products, CE metabolism in murine peritoneal macrophages was investigated. Ex vivo macrophage incubations revealed that cellular 15-LO directly oxidized multiple CE substrates from intracellular stores and from extracellular sources. Freshly harvested murine macrophages also contained 15-LO-specific oxCEs, suggesting the enzyme may act as a CE-oxidase in vivo. The metabolic fate of oxCEs, particularly the hydrolysis and remodeling of oxidized fatty acyl chains, was also examined in the macrophage. Metabolism of deuterated CE resulted in the genesis of deuterated, oxidized phosphatidylcholine (oxPC). Further experiments revealed these oxPC species were formed chiefly from the hydrolysis of oxidized CE and subsequent reacylation of the oxidized acyl components into PC. PMID:22665166

  5. Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications

    Science.gov (United States)

    Stengel, Andreas; Wang, Lixin; Taché, Yvette

    2011-01-01

    Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress. PMID:21782868

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

    Directory of Open Access Journals (Sweden)

    Surang Chankhamhaengdecha

    2013-01-01

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

  7. A clinical study on interdental separation techniques.

    NARCIS (Netherlands)

    Loomans, B.A.C.; Opdam, N.J.M.; Bronkhorst, E.M.; Roeters, F.J.M.; Dorfer, C.E.

    2007-01-01

    The effect of interdental separation of a special separation ring and wooden wedge was investigated. In a split-mouth design, 27 patients were randomly assigned to one of two groups (W or S). In 11 patients, an interdental wooden wedge (Hawe-Neos) was placed (group W), and in 16 patients, a

  8. Separation anxiety in children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001542.htm Separation anxiety in children To use the sharing features on this page, ... to test their independence. To get over separation anxiety, children need to: Feel safe in their home. Trust ...

  9. Magnetic separation of algae

    Science.gov (United States)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  10. Separators for electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2018-01-16

    Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Also provided are electrochemical cells comprising such separators.

  11. Engineering crystals that facilitate the acyl-transfer reaction: insight from a comparison of the crystal structures of myo-inositol-1,3,5-orthoformate-derived benzoates and carbonates.

    Science.gov (United States)

    Tamboli, Majid I; Krishanaswamy, Shobhana; Gonnade, Rajesh G; Shashidhar, Mysore S

    2016-11-01

    Minor variations in the molecular structure of constituent molecules of reactive crystals often yield crystals with significantly different properties due to altered modes of molecular association in the solid state. Hence, these studies could provide a better understanding of the complex chemical processes occurring in the crystalline state. However, reactions that proceed efficiently in molecular crystals are only a small fraction of the reactions that are known to proceed (with comparable efficiency) in the solution state. Hence, for consistent progress in this area of research, investigation of newer reactive molecular crystals which support different kinds of reactions and their related systems is essential. The crystal structures and acyl-transfer reactivity of a myo-inositol-1,3,5-orthoformate-derived dibenzoate and its carbonate (4-O-benzoyl-2-O-phenoxycarbonyl-myo-inositol 1,3,5-orthoformate, C 21 H 18 O 9 ) and thiocarbonate (4-O-benzoyl-2-O-phenoxythiocarbonyl-myo-inositol 1,3,5-orthoformate, C 21 H 18 O 8 S) analogs are compared with the aim of understanding the relationship between crystal structure and acyl-transfer reactivity. Insertion of an O atom in the acyl (or thioacyl) group of an ester gives the corresponding carbonate (or thiocarbonate). This seemingly minor change in molecular structure results in a considerable change in the packing of the molecules in the crystals of myo-inositol-1,3,5-orthoformate-derived benzoates and the corresponding carbonates. These differences result in a lack of intermolecular acyl-transfer reactivity in crystals of myo-inositol-1,3,5-orthoformate-derived carbonates. Hence, this study illustrates the sensitivity of the relative orientation of molecules, their packing and ensuing changes in the reactivity of resulting crystals to minor changes in molecular structure.

  12. Chromatographic separations of stereoisomers

    Energy Technology Data Exchange (ETDEWEB)

    Souter, R.W.

    1985-01-01

    This text covers both diastereomers and enantiomers; describes techniques for GC, HPLC, and other chromatographic methods; and tabulates results of various applications by both techniques and compound class. It provides current knowledge about separation mechanisms and interactions of asymmetric molecules, as well as experimental and commercial materials such as columns, instruments, and derivatization reagents. The contents also include stereoisomer separations by gas chromatography. Stereoisomer separations by high-performance liquid chromatography. Stereoisomer separations by other chromatographic techniques.

  13. Meniscus Membranes For Separation

    Science.gov (United States)

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  14. Meniscus membranes for separations

    Science.gov (United States)

    Dye, Robert C [Irvine, CA; Jorgensen, Betty [Jemez Springs, NM; Pesiri, David R [Aliso Viejo, CA

    2004-01-27

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  15. Bioconversion of α-linolenic acid to n-3 LCPUFA and expression of PPAR-alpha, acyl Coenzyme A oxidase 1 and carnitine acyl transferase I are incremented after feeding rats with α-linolenic acid-rich oils.

    Science.gov (United States)

    González-Mañán, Daniel; Tapia, Gladys; Gormaz, Juan Guillermo; D'Espessailles, Amanda; Espinosa, Alejandra; Masson, Lilia; Varela, Patricia; Valenzuela, Alfonso; Valenzuela, Rodrigo

    2012-07-01

    High dietary intake of n-6 fatty acids in relation to n-3 fatty acids may generate health disorders, such as cardiovascular and other chronic diseases. Fish consumption rich in n-3 fatty acids is low in Latin America, it being necessary to seek other alternatives to provide α-linolenic acid (ALA), precursor of n-3 LCPUFA (EPA and DHA). Two innovative oils were assayed, chia (Salvia hispanica) and rosa mosqueta (Rosa rubiginosa). This study evaluated hepatic bioconversion of ALA to EPA and DHA, expression of PPAR-α, acyl-Coenzyme A oxidase 1 (ACOX1) and carnitine acyltransferase I (CAT-I), and accumulation of EPA and DHA in plasma and adipose tissue in Sprague-Dawley rats. Three experimental groups were fed 21 days: sunflower oil (SFO, control); chia oil (CO); rosa mosqueta oil (RMO). Fatty acid composition of total lipids and phospholipids from plasma, hepatic and adipose tissue was assessed by gas-liquid chromatography and TLC. Expression of PPAR-α (RT-PCR) and ACOX1 and CAT-I (Western blot). CO and RMO increased plasma, hepatic and adipose tissue levels of ALA, EPA and DHA and decreased n-6:n-3 ratio compared to SFO (p oil.

  16. Positive Autoregulation of an Acyl-Homoserine Lactone Quorum-Sensing Circuit Synchronizes the Population Response.

    Science.gov (United States)

    Scholz, Rebecca L; Greenberg, E Peter

    2017-07-25

    Many proteobacteria utilize acyl-homoserine lactone quorum-sensing signals. At low population densities, cells produce a basal level of signal, and when sufficient signal has accumulated in the surrounding environment, it binds to its receptor, and quorum-sensing-dependent genes can be activated. A common characteristic of acyl-homoserine lactone quorum sensing is that signal production is positively autoregulated. We have examined the role of positive signal autoregulation in Pseudomonas aeruginosa We compared population responses and individual cell responses in populations of wild-type P. aeruginosa to responses in a strain with the signal synthase gene controlled by an arabinose-inducible promoter so that signal was produced at a constant rate per cell regardless of cell population density. At a population level, responses of the wild type and the engineered strain were indistinguishable, but the responses of individual cells in a population of the wild type showed greater synchrony than the responses of the engineered strain. Although sufficient signal is required to activate expression of quorum-sensing-regulated genes, it is not sufficient for activation of certain genes, the late genes, and their expression is delayed until other conditions are met. We found that late gene responses were reduced in the engineered strain. We conclude that positive signal autoregulation is not a required element in acyl-homoserine lactone quorum sensing, but it functions to enhance synchrony of the responses of individuals in a population. Synchrony might be advantageous in some situations, whereas a less coordinated quorum-sensing response might allow bet hedging and be advantageous in other situations. IMPORTANCE There are many quorum-sensing systems that involve a transcriptional activator, which responds to an acyl-homoserine lactone signal. In all of the examples studied, the gene coding for signal production is positively autoregulated by the signal, and it has even

  17. Green procedures for the chemoselective synthesis of acylals and ...

    Indian Academy of Sciences (India)

    Li C J and Chan T H 1999 Tetrahedron 55 11149. 5. Li C J 2005 Chem. Rev. 105 3095. 6. Greene T W and Wuts P G M 1999 In Protective Groups in Organic Synthesis 3rd ed. (New York: John Wiley and. Sons) p. 306. 7. Gregory M J 1970 J. Chem. Soc. B. 1201. 8. Jin T S, Sun G, Li Y W and Li T S 2002 Green Chem. 4. 255.

  18. Safety shutdown separators

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  19. 40 CFR 721.10055 - 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts.

    Science.gov (United States)

    2010-07-01

    ...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. 721.10055 Section 721.10055 Protection of...-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. (a) Chemical substance and...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts (PMN P-03-46; CAS No. 136504-87-5) is subject to...

  20. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  1. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  2. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  3. Preference of Arabidopsis thaliana GH3.5 acyl amido synthetase for growth versus defense hormone acyl substrates is dictated by concentration of amino acid substrate aspartate.

    Science.gov (United States)

    Mackelprang, Rebecca; Okrent, Rachel A; Wildermuth, Mary C

    2017-11-01

    The GH3 family of adenylating enzymes conjugate acyl substrates such as the growth hormone indole-3-acetic acid (IAA) to amino acids via a two-step reaction of acyl substrate adenylation followed by amino acid conjugation. Arabidopsis thaliana GH3.5 was previously shown to be unusual in that it could adenylate both IAA and the defense hormone salicylic acid (SA, 2-hydroxybenzoate). Our detailed studies of the kinetics of GH3.5 on a variety of auxin and benzoate substrates provides insight into the acyl preference and reaction mechanism of GH3.5. For example, we found GH3.5 activity on substituted benzoates is not defined by the substitution position as it is for GH3.12/PBS3. Most importantly, we show that GH3.5 strongly prefers Asp as the amino acid conjugate and that the concentration of Asp dictates the functional activity of GH3.5 on IAA vs. SA. Not only is Asp used in amino acid biosynthesis, but it also plays an important role in nitrogen mobilization and in the production of downstream metabolites, including pipecolic acid which propagates defense systemically. During active growth, [IAA] and [Asp] are high and the catalytic efficiency (k cat /K m ) of GH3.5 for IAA is 360-fold higher than with SA. GH3.5 is expressed under these conditions and conversion of IAA to inactive IAA-Asp would provide fine spatial and temporal control over local auxin developmental responses. By contrast, [SA] is dramatically elevated in response to (hemi)-biotrophic pathogens which also induce GH3.5 expression. Under these conditions, [Asp] is low and GH3.5 has equal affinity (K m ) for SA and IAA with similar catalytic efficiencies. However, the concentration of IAA tends to be very low, well below the K m for IAA. Therefore, GH3.5 catalyzed formation of SA-Asp would occur, fine-tuning localized defensive responses through conversion of active free SA to SA-Asp. Taken together, we show how GH3.5, with dual activity on IAA and SA, can integrate cellular metabolic status via Asp to

  4. Effect of polymer composition on rheological and degradation properties of temperature-responsive gelling systems composed of acyl-capped PCLA-PEG-PCLA.

    Science.gov (United States)

    Petit, Audrey; Müller, Benno; Meijboom, Ronald; Bruin, Peter; van de Manakker, Frank; Versluijs-Helder, Marjan; de Leede, Leo G J; Doornbos, Albert; Landin, Mariana; Hennink, Wim E; Vermonden, Tina

    2013-09-09

    In this study, the ability to modulate the rheological and degradation properties of temperature-responsive gelling systems composed of acyl-capped poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymers was investigated. Eight polymers with varying molecular weight of PCLA, caproyl/lactoyl ratio (CL/LA) and capped with either acetyl- or propionyl-groups were synthesized by ring-opening polymerization of L-lactide and ε-caprolactone in toluene using PEG as initiator and tin(II) 2-ethylhexanoate as catalyst, and subsequently reacted in solution with an excess of acyl chloride to yield fully acyl-capped PCLA-PEG-PCLA. The microstructure of the polymers was determined by (1)H NMR, and the thermal properties and crystallinity of the polymers in dry state and in 25 wt % aqueous systems were studied by differential scanning calorimetry and X-ray diffraction. Rheological and degradation/dissolution properties of aqueous systems composed of the polymers in 25 wt % aqueous systems were studied. (1)H NMR analysis revealed that the monomer sequence in the PCLA blocks was not fully random, resulting in relatively long CL sequences, even though transesterification was demonstrated by the enrichment with lactoyl units and the presence of PEG-OH end groups. Except the most hydrophilic polymer composed of acetyl-capped PCLA1400-PEG1500-PCLA1400 having a CL/LA molar ratio of 2.5, the polymers at 25 wt % in buffer were sols below room temperature and transformed into gels between room temperature and 37 °C, which makes them suitable as temperature-responsive gelling systems for drug delivery. Over a period of weeks at 37 °C, the systems containing polymers with long CL sequences (~8 CL) and propionyl end-groups became semicrystalline as shown by X-ray diffraction analysis. Degradation of the gels by dissolution at 37 °C took 100-150 days for the amorphous gels and 250-300 days for the semicrystalline gels

  5. Diversity and N-acyl-homoserine lactone production by Gammaproteobacteria associated with Avicennia marina rhizosphere of South Indian mangroves.

    Science.gov (United States)

    Viswanath, Ganga; Jegan, Sekar; Baskaran, Viswanathan; Kathiravan, Raju; Prabavathy, Vaiyapuri Ramalingam

    2015-07-01

    The diversity of N-acyl-homoserine lactone (AHL)-producing rhizosphere bacterial community associated with Avicennia marina in the mangrove ecosystems of South India was investigated. Approximately 800 rhizobacteria were isolated from A. marina, and they were screened for the production of AHL using two biosensors, Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NTL4 (pZLR4). Among the total isolates screened, 7% of the rhizobacteria showed positive induction for AHL signals. The BOX-PCR profile of 56 positive isolates represented 11 distinct genotypic groups. Phylogenetic analyses of the 16S rRNA sequences of 16 representatives showed that the isolates belonged to the class Gammaproteobacteria, which represented six different genera: Pseudomonas, Aeromonas, Vibrio, Photobacterium, Serratia and Halomonas. The study also identified three AHL-producing species, namely, Photobacterium halotolerans MSSRF QS48, Vibrio xiamenensis MSSRF QS47 and Pseudomonas sp. MSSRF QS1 that had not been reported previously. AHL profiling by TLC detected short chains C4, C6 and C8-HSL, and long chains C10 and C12-HSL with both unsubstituted and substituted side chains among the 16 representative AHL positives. This is the first report concerning the diversity of AHL-producing Gammaproteobacteria from mangrove ecosystems exhibiting diverse AHL profiles. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Metabolism of propionic acid to a novel acyl-coenzyme A thioester by mammalian cell lines and platelets.

    Science.gov (United States)

    Snyder, Nathaniel W; Basu, Sankha S; Worth, Andrew J; Mesaros, Clementina; Blair, Ian A

    2015-01-01

    Metabolism of propionate involves the activated acyl-thioester propionyl-CoA intermediate. We employed LC-MS/MS, LC-selected reaction monitoring/MS, and LC-high-resolution MS to investigate metabolism of propionate to acyl-CoA intermediates. We discovered that propionyl-CoA can serve as a precursor to the direct formation of a new six-carbon mono-unsaturated acyl-CoA. Time course and dose-response studies in human hepatocellular carcinoma HepG2 cells demonstrated that the six-carbon mono-unsaturated acyl-CoA was propionate-dependent and underwent further metabolism over time. Studies utilizing [(13)C1]propionate and [(13)C3]propionate suggested a mechanism of fatty acid synthesis, which maintained all six-carbon atoms from two propionate molecules. Metabolism of 2,2-[(2)H2]propionate to the new six-carbon mono-unsaturated acyl-CoA resulted in the complete loss of two deuterium atoms, indicating modification at C2 of the propionyl moiety. Coelution experiments and isotopic tracer studies confirmed that the new acyl-CoA was trans-2-methyl-2-pentenoyl-CoA. Acyl-CoA profiles following treatment of HepG2 cells with mono-unsaturated six-carbon fatty acids also supported this conclusion. Similar results were obtained with human platelets, mouse hepatocellular carcinoma Hepa1c1c7 cells, human bronchoalveolar carcinoma H358 cells, and human colon adenocarcinoma LoVo cells. Interestingly, trans-2-methyl-2-pentenoyl-CoA corresponds to a previously described acylcarnitine tentatively described in patients with propionic and methylmalonic acidemia. We have proposed a mechanism for this metabolic route consistent with all of the above findings. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  7. Metabolism of propionic acid to a novel acyl-coenzyme A thioester by mammalian cell lines and platelets[S

    Science.gov (United States)

    Snyder, Nathaniel W.; Basu, Sankha S.; Worth, Andrew J.; Mesaros, Clementina; Blair, Ian A.

    2015-01-01

    Metabolism of propionate involves the activated acyl-thioester propionyl-CoA intermediate. We employed LC-MS/MS, LC-selected reaction monitoring/MS, and LC-high-resolution MS to investigate metabolism of propionate to acyl-CoA intermediates. We discovered that propionyl-CoA can serve as a precursor to the direct formation of a new six-carbon mono-unsaturated acyl-CoA. Time course and dose-response studies in human hepatocellular carcinoma HepG2 cells demonstrated that the six-carbon mono-unsaturated acyl-CoA was propionate-dependent and underwent further metabolism over time. Studies utilizing [13C1]propionate and [13C3]propionate suggested a mechanism of fatty acid synthesis, which maintained all six-carbon atoms from two propionate molecules. Metabolism of 2,2-[2H2]propionate to the new six-carbon mono-unsaturated acyl-CoA resulted in the complete loss of two deuterium atoms, indicating modification at C2 of the propionyl moiety. Coelution experiments and isotopic tracer studies confirmed that the new acyl-CoA was trans-2-methyl-2-pentenoyl-CoA. Acyl-CoA profiles following treatment of HepG2 cells with mono-unsaturated six-carbon fatty acids also supported this conclusion. Similar results were obtained with human platelets, mouse hepatocellular carcinoma Hepa1c1c7 cells, human bronchoalveolar carcinoma H358 cells, and human colon adenocarcinoma LoVo cells. Interestingly, trans-2-methyl-2-pentenoyl-CoA corresponds to a previously described acylcarnitine tentatively described in patients with propionic and methylmalonic acidemia. We have proposed a mechanism for this metabolic route consistent with all of the above findings. PMID:25424005

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

    Science.gov (United States)

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

    2008-01-01

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

  9. Roles of Acyl-CoA:Diacylglycerol Acyltransferases 1 and 2 in Triacylglycerol Synthesis and Secretion in Primary Hepatocytes.

    Science.gov (United States)

    Li, Chen; Li, Lena; Lian, Jihong; Watts, Russell; Nelson, Randal; Goodwin, Bryan; Lehner, Richard

    2015-05-01

    Very low-density lipoprotein assembly and secretion are regulated by the availability of triacylglycerol. Although compelling evidence indicates that the majority of triacylglycerol in very low-density lipoprotein is derived from re-esterification of lipolytic products released by endoplasmic reticulum-associated lipases, little is known about roles of acyl-CoA:diacylglycerol acyltransferases (DGATs) in this process. We aimed to investigate the contribution of DGAT1 and DGAT2 in lipid metabolism and lipoprotein secretion in primary mouse and human hepatocytes. We used highly selective small-molecule inhibitors of DGAT1 and DGAT2, and we tracked storage and secretion of lipids synthesized de novo from [(3)H]acetic acid and from exogenously supplied [(3)H]oleic acid. Inactivation of individual DGAT activity did not affect incorporation of either radiolabeled precursor into intracellular triacylglycerol, whereas combined inactivation of both DGATs severely attenuated triacylglycerol synthesis. However, inhibition of DGAT2 augmented fatty acid oxidation, whereas inhibition of DGAT1 increased triacylglycerol secretion, suggesting preferential channeling of separate DGAT-derived triacylglycerol pools to distinct metabolic pathways. Inactivation of DGAT2 impaired cytosolic lipid droplet expansion, whereas DGAT1 inactivation promoted large lipid droplet formation. Moreover, inactivation of DGAT2 attenuated expression of lipogenic genes. Finally, triacylglycerol secretion was significantly reduced on DGAT2 inhibition without altering extracellular apolipoprotein B levels. Our data suggest that DGAT1 and DGAT2 can compensate for each other to synthesize triacylglycerol, but triacylglycerol synthesized by DGAT1 is preferentially channeled to oxidation, whereas DGAT2 synthesizes triacylglycerol destined for very low-density lipoprotein assembly. © 2015 American Heart Association, Inc.

  10. N(G)-Acyl-argininamides as NPY Y(1) receptor antagonists: Influence of structurally diverse acyl substituents on stability and affinity.

    Science.gov (United States)

    Weiss, Stefan; Keller, Max; Bernhardt, Günther; Buschauer, Armin; König, Burkhard

    2010-09-01

    N(G)-Acylated argininamides, covering a broad range of lipophilicity (calculated logD values: -1.8-12.5), were synthesized and investigated for NPY Y(1) receptor (Y(1)R) antagonism, Y(1)R affinity and stability in buffer (N(G)-deacylation, yielding BIBP 3226). Broad structural variation of substituents was tolerated. The K(i) (binding) and K(b) values (Y(1)R antagonism) varied from low nM to one-digit muM. Most of the compounds proved to be sufficiently stable at pH 7.4 over 90min to determine reliable pharmacological data in vitro. Exceptionally high instability was detected when a succinyl moiety was attached to the guanidine, probably, due to an intramolecular cleavage mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    the growth defect in the faa1Delta fat1Delta strain indicating some essential functions of Fat1p cannot be performed by Faa4p. Chromosomally encoded FAA1 and FAT1 are not able to suppress the growth deficiencies of the fat1Delta faa1Delta and faa1Delta faa4Delta strains, respectively, indicating Faa1p...... as trap were active when tested using the yeast two-hybrid system. Third, co-expressed, differentially tagged Fat1p and Faa1p or Faa4p were co-immunoprecipitated. Collectively, these data support the hypothesis that fatty acid import by vectorial acylation in yeast requires a multiprotein complex, which...... consists of Fat1p and Faa1p or Faa4p....

  12. Structure, High Affinity, and Negative Cooperativity of the Escherichia coli Holo-(Acyl Carrier Protein):Holo-(Acyl Carrier Protein) Synthase Complex

    Energy Technology Data Exchange (ETDEWEB)

    Marcella, Aaron M.; Culbertson, Sannie J.; Shogren-Knaak, Michael A.; Barb, Adam W.

    2017-11-01

    The Escherichia coli holo-(acyl carrier protein) synthase (ACPS) catalyzes the coenzyme A-dependent activation of apo-ACPP to generate holo-(acyl carrier protein) (holo-ACPP) in an early step of fatty acid biosynthesis. E. coli ACPS is sufficiently different from the human fatty acid synthase to justify the development of novel ACPS-targeting antibiotics. Models of E. coli ACPS in unliganded and holo-ACPP-bound forms solved by X-ray crystallography to 2.05 and 4.10 Å, respectively, revealed that ACPS bound three product holo-ACPP molecules to form a 3:3 hexamer. Solution NMR spectroscopy experiments validated the ACPS binding interface on holo-ACPP using chemical shift perturbations and by determining the relative orientation of holo-ACPP to ACPS by fitting residual dipolar couplings. The binding interface is organized to arrange contacts between positively charged ACPS residues and the holo-ACPP phosphopantetheine moiety, indicating product contains more stabilizing interactions than expected in the enzyme:substrate complex. Indeed, holo-ACPP bound the enzyme with greater affinity than the substrate, apo-ACPP, and with negative cooperativity. The first equivalent of holo-ACPP bound with a KD = 62 ± 13 nM, followed by the binding of two more equivalents of holo-ACPP with KD = 1.2 ± 0.2 μM. Cooperativity was not observed for apo-ACPP which bound with KD = 2.4 ± 0.1 μM. Strong product binding and high levels of holo-ACPP in the cell identify a potential regulatory role of ACPS in fatty acid biosynthesis.

  13. Des-acyl ghrelin inhibits the capacity of macrophages to stimulate the expression of aromatase in breast adipose stromal cells.

    Science.gov (United States)

    Au, CheukMan C; Docanto, Maria M; Zahid, Heba; Raffaelli, Francesca-Maria; Ferrero, Richard L; Furness, John B; Brown, Kristy A

    2017-06-01

    Des-acyl ghrelin is the unacylated form of the well-characterized appetite-stimulating hormone ghrelin. It affects a number of physiological processes, including increasing adipose lipid accumulation and inhibiting adipose tissue inflammation. Breast adipose tissue inflammation in obesity is associated with an increase in the expression of the estrogen biosynthetic enzyme, aromatase, and is hypothesized to create a hormonal milieu conducive to tumor growth. We previously reported that des-acyl ghrelin inhibits the expression and activity of aromatase in isolated human adipose stromal cells (ASCs), the main site of aromatase expression in the adipose tissue. The current study aimed to examine the effect of des-acyl ghrelin on the capacity of mouse macrophages (RAW264.7 cells) and human adipose tissue macrophages (ATMs) to stimulate aromatase expression in primary human breast ASCs. RAW264.7 cells were treated with 0, 10 and 100pM des-acyl ghrelin following activation with phorbol 12-myristate 13-acetate, and cells and conditioned media were collected after 6 and 24h. The effect of des-acyl ghrelin on macrophage polarization was examined by assessing mRNA expression of pro-inflammatory M1-specific marker Cd11c and anti-inflammatory M2-specific marker Cd206, as well as expression of Tnf and Ptgs2, known mediators of the macrophage-dependent stimulation of aromatase. TNF protein in conditioned media was assessed by ELISA. The effect of RAW264.7 and ATM-conditioned media on aromatase expression in ASCs was assessed after 6h. Results demonstrate des-acyl ghrelin significantly increases the expression of Cd206 and suppresses the expression of Cd11c, Tnf and Ptgs2 in activated RAW264.7 cells. Treatment of RAW264.7 and ATMs with des-acyl ghrelin also significantly reduces the capacity of these cells to stimulate aromatase transcript expression in human breast ASCs. Overall, these findings suggest that in addition to direct effects on aromatase in ASCs, des-acyl ghrelin also

  14. Guidelines for the diagnosis and treatment of idiopathic pulmonary fibrosis. Sociedad Española de Neumología y Cirugía Torácica (SEPAR) Research Group on Diffuse Pulmonary Diseases.

    Science.gov (United States)

    Xaubet, Antoni; Ancochea, Julio; Bollo, Elena; Fernández-Fabrellas, Estrella; Franquet, Tomás; Molina-Molina, Maria; Montero, Maria Angeles; Serrano-Mollar, Anna

    2013-08-01

    Idiopathic pulmonary fibrosis is defined as a chronic fibrosing interstitial pneumonia limited to the lung, of unknown cause, with poor prognosis and few treatment options. In recent years there has been an increase in their prevalence, probably due to the optimization of diagnostic methods and increased life expectancy. The ATS/ERS Consensus (2000) established the diagnostic criteria and recommendations for the assessment of the disease course and treatment. Later studies have helped to redefine diagnostic criteria and treatment options. In 2011, an international consensus was published, establishing diagnostic criteria and new treatment strategies. These guidelines have been updated with the newest aspects of diagnosis and treatment of idiopathic pulmonary fibrosis. A level of evidence has been identified for the most relevant questions, particularly with regard to treatment options. Copyright © 2012 SEPAR. Published by Elsevier Espana. All rights reserved.

  15. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  16. Centrifugal gas separator

    International Nuclear Information System (INIS)

    Sakurai, Mitsuo.

    1970-01-01

    A centrifugal gas separator of a highly endurable construction and with improved gas sealing qualities utilizes a cylincrical elastic bellows or similar system in cooperation with a system of dynamic pressure operable gas seals as means for removing separated gases from the interior of the rotor drum, collecting the separated gases in their respective separated gas chambers defined by the corresponding bellows and their supporting stationary wall members, gas seals and rotor end caps, and means for discharging to the exterior of the surrounding cylindrical wall member the gaseous components from their respective separated gas chambers. In the vicinity of the rotary drum motor is a mixed gas chamber and means for providing the gas mixture along a co-axial passage into the rotary drum chamber. Orifices are bored into the end caps of the rotary drum to direct the separated gases into the aforementioned separated gas chambers which, through the action of the gas seals, freely slide upon the rotating drum to collect and thereafter discharge the thus separated gases. Therefore, according to the present invention, helium gas used to prevent separated gas remixture is unnecessary and, furthermore, the gas seals and elastic bellows means provide an air-tight seal superior to that of the contact sealing system of the former art. (K.J. Owens)

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

    Science.gov (United States)

    Kishino, Hideyuki; Eguchi, Hiroki; Takagi, Keiko; Horiuchi, Hiroyuki; Fukuda, Ryouichi; Ohta, Akinori

    2014-03-07

    A yeast strain, in which endogenous phosphatidylcholine (PC) synthesis is controllable, was constructed by the replacement of the promoter of PCT1, encoding CTP:phosphocholine cytidylyltransferase, with GAL1 promoter in a double deletion mutant of PEM1 and PEM2, encoding phosphatidylethanolamine methyltransferase and phospholipid methyltransferase, respectively. This mutant did not grow in the glucose-containing medium, but the addition of dioctanoyl-phosphatidylcholine (diC8PC) supported its growth. Analyses of the metabolism of (13)C-labeled diC8PC ((methyl-(13)C)3-diC8PC) in this strain using electrospray ionization tandem mass spectrometry revealed that it was converted to PC species containing acyl residues of 16 or 18 carbons at both sn-1 and sn-2 positions. In addition, both acyl residues of (methyl-(13)C)3-diC8PC were replaced with 16:1 acyl chains in the in vitro reaction using the yeast cell extract in the presence of palmitoleoyl-CoA. These results indicate that PC containing short acyl residues was remodeled to those with acyl chains of physiological length in yeast. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Biosynthesis of mono-acylated mannosylerythritol lipid in an acyltransferase gene-disrupted mutant of Pseudozyma tsukubaensis.

    Science.gov (United States)

    Saika, Azusa; Utashima, Yu; Koike, Hideaki; Yamamoto, Shuhei; Kishimoto, Takahide; Fukuoka, Tokuma; Morita, Tomotake

    2018-02-01

    The basidiomycetous yeast genus Pseudozyma produce large amounts of mannosylerythritol lipids (MELs), which are biosurfactants. A few Pseudozyma strains produce mono-acylated MEL as a minor compound using excess glucose as the sole carbon source. Mono-acylated MEL shows higher hydrophilicity than di-acylated MEL and has great potential for aqueous applications. Recently, the gene cluster involved in the MEL biosynthesis pathway was identified in yeast. Here, we generated an acyltransferase (PtMAC2) deletion strain of P. tsukubaensis 1E5 with uracil auxotrophy as a selectable marker. A PtURA5-mutant with a frameshift mutation in PtURA5 was generated as a uracil auxotroph of strain 1E5 by ultraviolet irradiation on plate medium containing 5-fluoro-orotic acid (5-FOA). In the mutant, PtMAC2 was replaced with a PtURA5 cassette containing the 5' untranslated region (UTR) (2000 bp) and 3' UTR (2000 bp) of PtMAC2 by homologous recombination, yielding strain ΔPtMAC2. Based on TLC and NMR analysis, we found that ΔPtMAC2 accumulates MEL acylated at the C-2' position of the mannose moiety. These results indicate that PtMAC2p catalyzes acylation at the C-3' position of the mannose of MEL.

  19. A novel Dps-type protein from insect gut bacteria catalyses hydrolysis and synthesis of N-acyl amino acids.

    Science.gov (United States)

    Ping, Liyan; Büchler, Rita; Mithöfer, Axel; Svatos, Ales; Spiteller, Dieter; Dettner, Konrad; Gmeiner, Sophie; Piel, Jörn; Schlott, Bernhard; Boland, Wilhelm

    2007-06-01

    A novel type of a microbial N-acyl amino acid hydrolase (AAH) from insect gut bacteria was purified, cloned and functionally characterized. The enzyme was obtained from Microbacterium arborescens SE14 isolated from the foregut of larvae of the generalist herbivore Spodoptera exigua. The substrates of AAH are N-acyl-glutamines previously reported to elicit plant defence reactions after introduction into the leaf during feeding. The isolated AAH catalyses the hydrolysis of the amide bond (K(m) = 36 micromol l(-1)) and, less efficient, the formation (K(m) = 3 mmol l(-1)) of the elicitor active N-acyl amino acids. The AAH from M. arborescens SE14 shows no homology to known fatty acyl amidases (EC 3.5.1.4) but belongs to the family of Dps proteins (DNA-binding protein from starved cell). In line with other DPS proteins AAH is a homododecamer (monomer 17 181 Da) and contains iron atoms (c. 1-16 iron atoms per subunit). Unlike genuine DPS proteins the enzyme does not significantly bind DNA. Amino acid hydrolase is the first member of the DPS family that catalyses the cleavage or formation of amide bonds. The participation of a microbial enzyme in the homeostasis of N-acyl-glutamines in the insect gut adds further complexity to the interaction between plants and their herbivores.

  20. Anti-cancer agents based on N-acyl-2, 3-dihydro-1H-pyrrolo[2,3-b] quinoline derivatives and a method of making

    Energy Technology Data Exchange (ETDEWEB)

    Gakh, Andrei; Krasavin, Mikhail; Karapetian, Ruben; Rufanov, Konstantin A; Konstantinov, Igor; Godovykh, Elena; Soldatkina, Olga; Sosnov, Andrey V

    2013-04-16

    The present disclosure relates to novel compounds that can be used as anti-cancer agents in the prostate cancer therapy. In particular, the invention relates to N-acyl derivatives of 2,3-dihydro-1H-pyrrolo[2,3-b]quinolines having the structural Formula (I), ##STR00001## stereoisomers, tautomers, racemics, prodrugs, metabolites thereof, or pharmaceutically acceptable salt and/or solvate thereof. The meaning of R1 is independently selected from H; C1-C6 Alkyl, cyclo-Alkyl or iso-Alkyl substituents; R2 is selected from C1-C6 Alkyl, cyclo-Alkyl or iso-Alkyl; substituted or non-substituted, fused or non-fused to substituted or non-substituted aromatic ring, aryl or heteroaryl groups. The invention also relates to methods for preparing said compounds, and to pharmaceutical compositions comprising said compounds.

  1. Antibacterial and antifungal activities of new acylated derivatives of epigallocatechin gallate

    Directory of Open Access Journals (Sweden)

    Yoshimi eMatsumoto

    2012-02-01

    Full Text Available (--Epigallocatechin-3-O-gallate (EGCG has useful antiviral, antimicrobial, antitoxin, and antitumor properties. Previously, Mori, S. et al. (Bioorg Med Chem Lett 18:4249-4252, 2008 found that addition of long acyl chains (C16–18 to EGCG enhanced its anti-influenza virus activity up to 44-fold. The chemical stability of EGCG against oxidative degradation was also enhanced by acylation. We further evaluated the in vitro activity spectrum of the EGCG derivatives against a wide range of bacteria and fungi. A series of EGCG O-acyl derivatives were synthesized by lipase-catalyzed transesterification. These derivatives exhibited several-fold higher activities than EGCG, particularly against Gram-positive organisms. Antifungal activities of the derivatives were also 2 to 4-fold superior to those of EGCG. The activities of the EGCG derivatives against Gram-negative bacteria were not distinguishable from those of EGCG. Among the derivatives evaluated, MICs of dioctanoate, palmitate (C16, palmitoleate, and linolenate for 17 Staphylococcus aureus strains were 4–32 μg/ml, although MIC of EGCG for these 17 strains was >128 μg/ml. C16 demonstrated rapid bactericidal activity against MRSA at 25 μg/ml. The enhanced activity of C16 against S. aureus was supported by its increased membrane permeabilizing activity determined by increased SYTOX Green uptake. The EGCG derivatives were exported by the efflux pump AcrAB-TolC of Escherichia coli. The tolC deletion mutant exhibited higher sensitivity to C16 than to EGCG. Addition of long alkyl chains to EGCG significantly enhanced its activities against various bacteria and fungi, particularly against S. aureus including MRSA. C16 would be an alternative to antibiotics and disinfectants.

  2. Tuning of acyl-ACP thioesterase activity directed for tailored fatty acid synthesis.

    Science.gov (United States)

    Feng, Yanbin; Zhang, Yunxiu; Wang, Yayue; Liu, Jiao; Liu, Yinghui; Cao, Xupeng; Xue, Song

    2018-04-01

    Medium-chain fatty acids have attracted significant attention as sources of biofuels in recent years. Acyl-ACP thioesterase, which is considered as the key enzyme to determine the carbon chain length, catalyzes the termination of de novo fatty acid synthesis. Although recombinant medium-chain acyl-ACP thioesterase (TE) affects the fatty acid profile in heterologous cells, tailoring of the fatty acid composition merely by engineering a specific TE is still intractable. In this study, the activity of a C8-C10-specific thioesterase FatB2 from Cuphea hookeriana on C10-ACP was quantified twice as high as that on C8-ACP based on a synthetic C8-C16 acyl-ACP pool in vitro. Whereas in vivo, it was demonstrated that ChFatB2 preferred to accumulate C8 fatty acids with 84.9% composition in the ChFatB2-engineered E. coli strain. To achieve C10 fatty acid production, ChFatB2 was rationally tuned based on structural investigation and enzymatic analysis. An I198E mutant was identified to redistribute the C8-ACP flow, resulting in C10 fatty acid being produced as the principal component at 57.6% of total fatty acids in vivo. It was demonstrated that the activity of TE relative to β-ketoacyl-ACP synthases (KAS) directly determined the fatty acid composition. Our results provide a prospective strategy in tailoring fatty acid synthesis by tuning of TE activities based on TE-ACP interaction.

  3. Low expression of long-chain acyl-CoA dehydrogenase in human skeletal muscle

    Science.gov (United States)

    Maher, Amy C.; Mohsen, Al-Walid; Vockley, Jerry; Tarnopolsky, Mark A.

    2014-01-01

    Purpose Long-chain acyl-CoA dehydrogenase (LCAD) is a mitochondrial flavoenzyme thought to be one of the major enzymes responsible for the first step of long-chain fatty acid (LCFA) β-oxidation. Surprisingly, recent studies have shown LCAD is hardly detectable in human tissues such as liver and heart. Skeletal muscle is the largest organ in the body in terms of mass, and accounts for the majority of LCFA oxidation, especially during exercise. The purpose of this study was to investigate the expression levels of LCAD in human skeletal muscle. Methods Muscle biopsies were obtained from the vastus lateralis of healthy athletic men and women, and examined for mRNA abundance, protein content, and enzyme activity of LCAD. We compared LCAD content with that of very-long chain acyl-CoA dehydrogenase (VLCAD) and medium chain acyl-CoA dehydrogenase (MCAD); two mitochondrial β-oxidation enzymes that have overlapping chain-length specificity to that of LCAD. LCAD protein content and enzyme activity were also examined in enriched mitochondrial protein fractions. As controls, LCAD presence in skeletal muscle was compared to human heart, liver, and mouse skeletal muscle. Results The mRNA presence of LCAD in human skeletal muscle is significantly less than VLCAD and MCAD (0.08±0.01 vs 7.3±0.5 vs 2.4±0.2 respectively, P≤0.0001). LCAD protein was undetectable in human muscle homogenates, and coordinately LCAD enzyme activity was undetectable in enriched mitochondrial samples. Conclusion LCAD is minimally expressed in human skeletal muscle and likely does not play a significant role in LCFA oxidation. PMID:20363655

  4. Only Acyl Carrier Protein 1 (AcpP1 Functions in Pseudomonas aeruginosa Fatty Acid Synthesis

    Directory of Open Access Journals (Sweden)

    Jin-Cheng Ma

    2017-11-01

    Full Text Available The genome of Pseudomonas aeruginosa contains three open reading frames, PA2966, PA1869, and PA3334, which encode putative acyl carrier proteins, AcpP1, AcpP2, and AcpP3, respectively. In this study, we found that, although these apo-ACPs were successfully phosphopantetheinylated by P. aeruginosa phosphopantetheinyl transferase (PcpS and all holo-forms of these proteins could be acylated by Vibrio harveyi acyl-ACP synthetase (AasS, only AcpP1 could be used as a substrate for the synthesis of fatty acids, catalyzed by P. aeruginosa cell free extracts in vitro, and only acpP1 gene could restore growth in the Escherichia coliacpP mutant strain CY1877. And P. aeruginosaacpP1 could not be deleted, while disruption of acpP2 or acpP3 in the P. aeruginosa genome allowed mutant strains to grow as well as the wild type strain. These findings confirmed that only P. aeruginosa AcpP1 functions in fatty acid biosynthesis, and that acpP2 and acpP3 do not play roles in the fatty acid synthetic pathway. Moreover, disruption of acpP2 and acpP3 did not affect the ability of P. aeruginosa to produce N-acylhomoserine lactones (AHL, but replacement of P. aeruginosaacpP1 with E. coliacpP caused P. aeruginosa to reduce the production of AHL molecules, which indicated that neither P. aeruginosa AcpP2 nor AcpP3 can act as a substrate for synthesis of AHL molecules in vivo. Furthermore, replacement of acpP1 with E. coliacpP reduced the ability of P. aeruginosa to produce some exo-products and abolished swarming motility in P. aeruginosa.

  5. Endogenous ghrelin-O-acyltransferase (GOAT) acylates local ghrelin in the hippocampus.

    Science.gov (United States)

    Murtuza, Mohammad I; Isokawa, Masako

    2018-01-01

    Ghrelin is an appetite-stimulating peptide. Serine 3 on ghrelin must be acylated by octanoate via the enzyme ghrelin-O-acyltransferase (GOAT) for the peptide to bind and activate the cognate receptor, growth hormone secretagogue receptor type 1a (GHSR1a). Interest in GHSR1a increased dramatically when GHSR1a mRNA was demonstrated to be widespread in the brain, including the cortex and hippocampus, indicating that it has multifaceted functions beyond the regulation of metabolism. However, the source of octanoylated ghrelin for GHSR1a in the brain, outside of the hypothalamus, is not well understood. Here, we report the presence of GOAT and its ability to acylate non-octanoylated ghrelin in the hippocampus. GOAT immunoreactivity is aggregated at the base of the dentate granule cell layer in the rat and wild-type mouse. This immunoreactivity was not affected by the pharmacological inhibition of GHSR1a or the metabolic state-dependent fluctuation of systemic ghrelin levels. However, it was absent in the GHSR1a knockout mouse hippocampus, pointing the possibility that the expression of GHSR1a may be a prerequisite for the production of GOAT. Application of fluorescein isothiocyanate (FITC)-conjugated non-octanoylated ghrelin in live hippocampal slice culture (but not in fixed culture or in the presence of GOAT inhibitors) mimicked the binding profile of FITC-conjugated octanoylated ghrelin, suggesting that extracellularly applied non-octanoylated ghrelin was acylated by endogenous GOAT in the live hippocampus while GOAT being mobilized out of neurons. Our results will advance the understanding for the role of endogenous GOAT in the hippocampus and facilitate the search for the source of ghrelin that is intrinsic to the brain. © 2017 International Society for Neurochemistry.

  6. ADSORPTION METHOD FOR SEPARATING METAL CATIONS

    Science.gov (United States)

    Khym, J.X.

    1959-03-10

    The chromatographic separation of fission product cations is discussed. By use of this method a mixture of metal cations containing Zr, Cb, Ce, Y, Ba, and Sr may be separated from one another. Mentioned as preferred exchange adsorbents are resins containing free sulfonic acid groups. Various eluants, such as tartaric acid, HCl, and citric acid, used at various acidities, are employed to effect the selective elution and separation of the various fission product cations.

  7. Rheology of sheared gels based on low acyl-gellan gum.

    Science.gov (United States)

    García, M Carmen; Alfaro, M Carmen; Muñoz, José

    2016-06-01

    Sheared gels containing 0.2 wt% low-acyl gellan gum were prepared by different processing protocols using Na(+) or Ca(2+) as gel-promoting ions. Rheology and confocal laser scanning microscopy were used to gain information on the sample structure. Confocal laser scanning microscopy revealed the formation of a heterogeneous microstructure consisting of a dispersion of gel-like clusters. Small amplitude oscillatory shear stress results indicated that their viscoelastic properties had a predominant elastic component. Flow curves exhibited very high viscosities at low shear stress, an apparent yield stress and very shear thinning behaviour, supporting their applications as a stabilizer. © The Author(s) 2015.

  8. Kinetics of aniline acylation with m-carboranecarbonic acid monochloroanhydride in nonaqueons media

    International Nuclear Information System (INIS)

    Vorob'ev, N.K.; Chizhova, E.A.; Korshak, V.V.; Bekasova, N.I.; Komarova, L.G.; AN SSSR, Moscow. Inst. Ehlementoorganicheskikh Soedinenij)

    1976-01-01

    Reactions of aniline acylation with the chloranhydride of m-carborancarboxylic acid in the solvents of various nature are shown to occur at the low values of activation energy (E<10 kcal/mole) and activation entropy. The nature of the organic solvent produces a substantial effect of the reaction rate. Oxygen- and nitrogen-bearing solvents exhibit a sharp increase in the constant of the reaction rate (k). For example, k for acytonitrile at 25degC will be 2370 l/mole.min. Such an accelerating effect is related to the specific interaction of aniline with the solvent

  9. The Bacillus subtilis Acyl Lipid Desaturase Is a Δ5 Desaturase

    Science.gov (United States)

    Altabe, Silvia G.; Aguilar, Pablo; Caballero, Gerardo M.; de Mendoza, Diego

    2003-01-01

    Bacillus subtilis was recently reported to synthesize unsaturated fatty acids (UFAs) with a double bond at positions Δ5, Δ7, and Δ9 (M. H. Weber, W. Klein, L. Muller, U. M. Niess, and M. A. Marahiel, Mol. Microbiol. 39:1321-1329, 2001). Since this finding would have considerable importance in the double-bond positional specificity displayed by the B. subtilis acyl lipid desaturase, we have attempted to confirm this observation. We report that the double bond of UFAs synthesized by B. subtilis is located exclusively at the Δ5 position, regardless of the growth temperature and the length chain of the fatty acids. PMID:12730185

  10. Although it is rapidly metabolized in cultured rat hepatocytes, lauric acid is used for protein acylation

    OpenAIRE

    Rioux, Vincent,; Daval, Stéphanie; Guillou, Hervé; Jan, Sophie; Legrand, Philippe,

    2003-01-01

    International audience; This study was designed to examine the metabolic fate of exogenous lauric acid in cultured rat hepatocytes, in terms of both lipid metabolism and acylation of proteins. Radiolabeled [ 1-$^{14}$C] -lauric acid at 0.1 mM in the culture medium was rapidly taken up by the cells ($94.8 \\pm 2.2\\%$ of the initial radioactivity was cleared from the medium after a 4 h incubation) but its incorporation into cellular lipids was low ($24.6 \\pm 4.2\\%$ of initial radioactivity after...

  11. Acylated Flavone Glycosides from the Roots of Saussurea lappa and Their Antifungal Activity

    Directory of Open Access Journals (Sweden)

    Yemireddy Venkata Ramnareddy

    2007-03-01

    Full Text Available The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the isolated compounds and their mixture were tested on nine fungal and four bacterial strains, using the microdilution method. The compounds and mixture showed moderate to high antifungal activity against most of the fungi tested, compared to a miconazole standard, while only one compound and the mixture showed antibacterial activity against all strains tested.

  12. An Acylated Kaempferol Glycoside from Flowers of Foeniculum vulgare and F. Dulce

    OpenAIRE

    Soliman, Fathy M.; Shehata, Afaf H.; Khaleel, Amal E.; Ezzat, Shahera M.

    2002-01-01

    An acylated kaempferol glycoside, namely kaempferol-3-O-α-L-(2”,3”-di-E-pcoumaroyl)-rhamnoside (1) was isolated from the flowers of Foeniculum vulgare Mill. and F. dulce DC. It is thus isolated for the first time from family Apiaceae. In addition, the different organs of both plants afforded six flavonoid glycosides - namely afzelin (kaempferol-3-O-α-L-rhamnoside) (2), quercitrin (3), isorhamnetin-3-O-β-D-glucoside (4), isoquercitrin (5), rutin (6), and miquelianin (quercetin-3...

  13. A severe genotype with favourable outcome in very long chain acyl-CoA dehydrogenase deficiency

    DEFF Research Database (Denmark)

    Touma, E H; Rashed, M S; Vianey-Saban, C

    2001-01-01

    A patient with very long chain acyl-CoA dehydrogenase (VLCAD) deficiency is reported. He had a severe neonatal presentation and cardiomyopathy. He was found to be homozygous for a severe mutation with no residual enzyme activity. Tandem mass spectrometry on dried blood spots revealed increased lo...... chain acylcarnitines. VLCAD enzyme activity was severely decreased to 2% of control levels. Dietary management consisted of skimmed milk supplemented with medium chain triglycerides and L-carnitine. Outcome was good and there was no acute recurrence....

  14. Synthesis of new 3-and 4-substituted analogues of acyl homoserine lactone quorum sensing autoinducers

    DEFF Research Database (Denmark)

    Olsen, Jacob Alsbæk; Severinsen, Rune Eg; Rasmussen, Thomas Bovbjerg

    2002-01-01

    The quorum sensing mechanism in Gram-negative bacteria uses small intercellular signal molecules, N-acyl-homoserine lactones (AHLs), to control transcription of specific genes in relation to population density. In this communication, we describe the parallel synthesis of new AHL analogues, in which...... substituents have been introduced into the 3- and 4-positions of the lactone ring. These analogues have been screened for their ability to activate and inhibit a Vibrio fischeri LuxI/LuxR-derived quorum sensing reporter system....

  15. Quorum sensing signal molecules (acylated homoserine lactones) in Gram-negative fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Dalsgaard, Inger; Nielsen, K.F.

    2005-01-01

    The aim of the present study was to investigate the production of quorum sensing signals (specifically acylated homoserine lactones, AHLs) among a selection of strains of Gram-negative fish bacterial pathogens. These signals are involved in the regulation of virulence factors in some human....... In conclusion, the production of quorum sensing signals, AHLs, is common among the strains that we examined. If the AHL molecules regulate the expression of the virulence phenotype in these bacteria, as shown to occur in some bacterial pathogens, novel disease control measures may be developed by blocking AHL...

  16. Separation and preconcentration of platinum-group metals from spent autocatalysts solutions using a hetero-polymeric S, N-containing sorbent and determination by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Eskina, Vasilina V; Dalnova, Olga A; Filatova, Daria G; Baranovskaya, Vasilisa B; Karpov, Yuri A

    2016-10-01

    This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone. It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015-0.00050; 0.170-0.189; 0.0180-0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10(-6)wt% for Pt, 1.8·10(-6)wt% for Pd, and 3.4·10(-6)wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10(-5)wt% for Pt, 6.9·10(-5)wt% for Pd, and 8.3·10(-5)wt% for Rh. To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The

  17. Young children's adaptations to repeated separations from their mothers.

    Science.gov (United States)

    Field, T M

    1991-06-01

    80 infants, toddlers, and preschoolers were observed before, during, and after separations from their mothers, who were attending conferences (M duration = 4 days). Half the sample was separated only once and the other half experienced 3 separations across a 6-month period. The study was designed: (a) to determine how separations affect children's behavior when there are no changes in the family constellation as there typically are during other separations, such as the birth of a new child, and (b) to determine the effects of repeated separations. Fewer changes in sleep and play behaviors suggested that this type of separation was less stressful than separations for the birth of another child. Nonetheless, the separations were still stressful, but principally for the single-separation group. In that group, changes were noted in both play and sleep behaviors. Following reunion, their sleep behaviors and more sophisticated play behaviors returned to baseline. However, activity level and the more insecure behaviors, such as wandering aimlessly, watching other children play, and interacting with their teachers, remained elevated following the mother's return. The multiple-separation group, in contrast, showed only 1 behavior change during their third separation, i.e., reduced interactions with their peers during the separation period, which returned to baseline following reunion. Repeated-measures analyses of the first and third separations of the multiple-separations group suggested that only the first separation was stressful. Thus, the infants and children in this study seemed to adapt to repeated separations.

  18. Separation of ionic solutes

    International Nuclear Information System (INIS)

    1986-01-01

    The conference proceedings contain 44 papers of which 19 were incorporated in INIS. The subject of these is the use of solvent extraction or emulsion membrane extraction for separation of fission products, rare earth compounds and actinide compunds; the sorption of radionuclides; and the use of adsorbents and chelating agents in separation processes. (J.P.)

  19. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1979-01-01

    A method is described for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption after which more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  20. Separation anxiety disorder

    NARCIS (Netherlands)

    Nauta, M.H.; Emmelkamp, P.M.G.; Sturmey, P.; Hersen, M.

    2012-01-01

    Separation anxiety disorder (SAD) is the only anxiety disorder that is specific to childhood; however, SAD has hardly ever been addressed as a separate disorder in clinical trials investigating treatment outcome. So far, only parent training has been developed specifically for SAD. This particular

  1. [Simultaneous determination of five alkaloids in Niuhuang Shangqing Tablets by micellar electrokinetic chromatography-mass spectrometry using laurel acyl malic acid ester].

    Science.gov (United States)

    Hu, Mengdi; Su, Di; Fan, Xiaosu; Yu, Jianhua; Xu, Yuanjin

    2012-12-01

    A micellar electrokinetic chromatography-mass spectrometric method based on laurel acyl malic acid ester (LMAE) for the separation and determination of coptisine, berberine, jatrorrhizine, phellodendrine and ligustrazine in Niuhuang Shangqing Tablets was established. The baseline separation of the five compounds was attained within 18 min by an uncoated capillary (88 cm x 50 microm) on the operating voltage of 25 kV using 7.5 mmol/L LMAE-15 mmol/L ammonia-50 mmol/L ammonium acetate mixture (pH = 7.0) containing 12.5% (v/v) acetonitrile as the electrophoretic medium and 50% 2-propanol aqueous solution (containing 3 mmol/L acetic acid) as the sheath liquid. The peak area of each component to its concentration showed a good linear relationship. The relative standard deviations of migration times and peak areas of the five components were less than 5% and the recoveries were between 96.0% and 105%. The developed method is simple, rapid, accurate and is suitable for the routine analysis of the five alkaloid components in Niuhuang Shangqing Tablets.

  2. Glu-Trp-ONa or its acylated analogue (R-Glu-Trp-ONa administration enhances the wound healing in the model of chronic skin wounds in rabbits

    Directory of Open Access Journals (Sweden)

    Shevtsov MA

    2015-03-01

    Full Text Available Maxim A Shevtsov,1,2 Larisa V Smagina,1 Tatiana A Kudriavtceva,3 Sergey V Petlenko,4 Irina V Voronkina1 1Institute of Cytology of the Russian Academy of Sciences (RAS, St Petersburg, Russia; 2IP Pavlov State Medical University of St Petersburg, St Petersburg, Russia; 3Institute of Experimental Medicine of the North-West Branch of the Russian Academy of Medical Sciences (IEM NWB RAMS, St Petersburg, Russia; 4Military Medical Academy, St Petersburg, Russia Abstract: The management of chronic skin wounds represents a major therapeutic challenge. The synthesized dipeptide (Glu-Trp-ONa and its acylated analogue (R-Glu-Trp-ONa were assessed in the model of nonhealing dermal wounds in rabbits in relation to their healing properties in wound closure. Following wound modeling, the rabbits received a course of intraperitoneal injections of Glu-Trp-ONa or R-Glu-Trp-ONa. Phosphate-buffered saline and Solcoseryl® were applied as negative and positive control agents, respectively. An injection of Glu-Trp-ONa and R-Glu-Trp-ONa decreased the period of wound healing in animals in comparison to the control and Solcoseryl-treated groups. Acylation of Glu-Trp-ONa proved to be beneficial as related to the healing properties of the dipeptide. Subsequent zymography analyses showed that the applied peptides decreased the proteolytic activity of matrix metalloproteinases MMP-9, MMP-8, and MMP-2 in the early inflammatory phase and reversely increased the activity of MMP-9, MMP-8, and MMP-1 in the remodeling phase. Histological analyses of the wound sections (hematoxylin–eosin, Mallory’s staining confirmed the enhanced formation of granulation tissue and re-epithelialization in the experimental groups. By administering the peptides, wound closures increased significantly through the modulation of the MMPs’ activity, indicating their role in wound healing. Keywords: chronic wound, matrix metalloproteinases, small peptides

  3. Ground-State Distortion in N-Acyl-tert-butyl-carbamates (Boc) and N-Acyl-tosylamides (Ts): Twisted Amides of Relevance to Amide N-C Cross-Coupling.

    Science.gov (United States)

    Szostak, Roman; Shi, Shicheng; Meng, Guangrong; Lalancette, Roger; Szostak, Michal

    2016-09-02

    Amide N-C(O) bonds are generally unreactive in cross-coupling reactions employing low-valent transition metals due to nN → π*C═O resonance. Herein we demonstrate that N-acyl-tert-butyl-carbamates (Boc) and N-acyl-tosylamides (Ts), two classes of acyclic amides that have recently enabled the development of elusive amide bond N-C cross-coupling reactions with organometallic reagents, are intrinsically twisted around the N-C(O) axis. The data have important implications for the design of new amide cross-coupling reactions with the N-C(O) amide bond cleavage as a key step.

  4. Acylation of lithiated trimethylsilyl malonates and esters applied to the synthesis of molecules of biological interest, labelled with carbon 14

    International Nuclear Information System (INIS)

    Gorichon, Liliane

    1978-01-01

    This research thesis first reports an attempt to generalise the method of acylation of lithiated trimethylsilyl (TMS) malonates by introduction of new organic functions into the radical. This leads to the synthesis of some alkaloids such as nicotine and contine. The author also shows that fat acids can be labelled with carbon 14 in any position of the carbon chain. Thus, acylation of these malonates have been performed by using different acid chlorides. Then, the author reports attempts to simplify this method by using α-lithiated trimethylsilyl esters instead of malonates. He reports attempts of acylation of TMS isobutyrate, TMS proprionate and TMS acetate, by using different radioactive acid chlorides (benzoyl chloride, nicotinoyl chloride, lauryl chloride, and oleyl chloride). The author finally shows that both methods are equivalent by synthesising muscalure from TMS butylmalonate as well as from TMS hexanoate

  5. Predictions of Phase Separation in Three-Component Lipid Membranes by the MARTINI Force Field

    DEFF Research Database (Denmark)

    Davis, Ryan S.; Sunil Kumar, P. B.; Sperotto, Maria Maddalena

    2013-01-01

    is to understand which types of unsaturated PC induce the formation of thermodynamically stable coexisting phases when added to mixtures of DPPC and Chol and to unravel the mechanisms that drive phase separation in such three-component mixtures. Our simulations indicate that the currently used MARTINI force field...... the MARTINI force field, is primarily due to the interactions between the coarse-grained molecules, i.e., the beads, rather than due to the differences between the conformations of saturated and unsaturated lipid acyl chains, namely entropy driven....

  6. Synthesis, Crystal Structural Characterization and Biological Properties of Thiosemicarbazones of Schiff Bases Derived from 4-Acyl-2-pyrazoline-5-one

    Directory of Open Access Journals (Sweden)

    Arjunsinh Rana

    2011-01-01

    Full Text Available A novel synthesis, single crystal and biological activity 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 was carried out. The compounds were characterized on the basis of elemental analysis, IR, 1H NMR, Mass, DSC and 13C NMR spectral data. The compounds were tested for their antibacterial activity against various gram +ve and -ve bacteria. The results were compared with the marketed drugs. The crystal structure was determined by single x-ray diffraction. 4-Acetyl thiosemicarbazone-3-methyl-1-(4`-methylphenyl-2-pyrazolin-5-one(AcPTMP-ths crystallizes in the monoclinic system, space group P21/n with a=6.0828(7Å, b=29.547(4Å, c=7.9101(15Å, α=90°, γ=95.602(15°, γ=90°, V=1414.9(4 Å3, Z=4, Dc=1.429 mg/m3 and 4-Propionylthiosemicarbazone-3-methyl-1-(4`-methylphenyl-2-pyrazolin-5-one (PropPTMP-ths crystallizes in the monoclinic system, space group P21/c with a=13.5622(10Å, b=13.3671(12Å, c=22.151(2Å, α=90°, β=93.13(7°, γ=90°, V=4010.1(6 Å3, Z=8, Dc=1.310 mg/m3. The compounds were screened for antibacterial properties and exhibited potential activity.

  7. Acylated and deacylated saponins of Quillaja saponaria mixture as adjuvants for the FML-vaccine against visceral leishmaniasis.

    Science.gov (United States)

    Oliveira-Freitas, E; Casas, C P; Borja-Cabrera, G P; Santos, F N; Nico, D; Souza, L O P; Tinoco, L W; da Silva, B P; Palatnik, M; Parente, J P; Palatnik-de-Sousa, C B

    2006-05-01

    The adjuvant of the FML-vaccine against murine and canine visceral leishmaniasis, the Riedel de Haen saponin mixture, was fractionated by ion exchange chromatography on DEAE-cellulose to afford one TLC homogeneous Quillaja saponaria Molina QS21 saponin fraction (18.0%), a mixture of two deacylsaponins (19.4%), sucrose (39.9%), sucrose and glucose (19.7%), rutin (0.8%) and quercetin (2.2%), that were identified by comparison of 1H and 13C NMR spectroscopy. The QS21 shows the typical aldehyde group in C-23 (65% equatorial) and a normonoterpene moiety acylated in C-28. The deacylsaponins show the aldehyde group but do not have the normonoterpene moiety. Balb/c mice were vaccinated with 150 microg of FML antigen of Leishmania donovani and 100 microg of each obtained fraction and further challenged by infection with 10(8) amastigotes of Leishmania chagasi. The safety analysis and the effect on humoral and cellular immune responses and in clinical signs showed that the QS21 saponin and the deacylsaponins are the most active adjuvant compounds of the Riedel the Haen saponin mixture. Both induced the highest and non-significantly different increases in DTH, CD4+ T lymphocytes in spleen, IFN-gamma in vitro, body weight gain and the most pronounced reduction of parasite burden in liver (95% for QS21 and 86% for deacylsaponins; p>0.05). While the QS21 showed mild toxicity, significant adjuvant effect on the anti-FML humoral response before and after infection, and decrease in liver relative weight, the deacylsaponins showed no toxicity, less haemolysis and antibody and DTH responses increased mainly after infection, still inducing a stronger Leishmania-specific in vitro splenocyte proliferation. Our results confirm in the Riedel de Haen saponin extract the presence of deacylsaponins normonoterpene-deprivated which are non-toxic and capable of inducing a specific and strong immunoprotective response in vaccination against murine visceral leishmaniasis.

  8. Preparation of 5-acyl- and 5-aryl-substituted 1-(benzyloxy)pyrazoles via directed ortho-lithiation/transmetalation and palladium catalyzed cross- coupling

    DEFF Research Database (Denmark)

    Kristensen, Jesper Langgaard; Begtrup, M.; Vedsø, P.

    1998-01-01

    Palladium(0) catalyzed cross-coupling of 1-(benzyloxy)pyrazol-5-ylzinc halides 3a,b, prepared by transmetalation of 1-(benzyloxy)-5-lithiopyrazole (2), with acyl chlorides produced 5 acyl-1-(benzyloxy)pyrazoles 4a-d in high yields. Similar coupling of the pyrazol-5-ylzinc halide with amino-, hydr...

  9. Determination of hydrophobic coenzyme a esters and other lipids using a biosensor comprising a modified coenzyme a- and acyl-coa binding protein (acbp)

    DEFF Research Database (Denmark)

    2002-01-01

    , food and feed preparations, tissue extracts, acyl-CoA synthetase reaction media and various laboratory conditions using a modified Coenzyme A- and acyl-CoA binding protein (ACBP) is provided. Furthermore the invention relates to a construct comprising a peptide and a signal moiety for performing...

  10. Changes in acyl and total ghrelin concentrations and their association with dry matter intake, average daily gain, and feed efficiency of finishing beef steers and heifers

    Science.gov (United States)

    Ghrelin is a peptide hormone produced in the gut that is implicated in signaling appetite and regulating DMI. The objective of this experiment was to determine the change in acyl ghrelin, total ghrelin, and the ghrelin ratio (acyl ghrelin/total ghrelin) over an 84-d DMI and ADG measurement period a...

  11. Isotope separation process

    International Nuclear Information System (INIS)

    Cox, D.M.; Maas, E.T.

    1982-01-01

    Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO2a2)n, where a is a monovalent anion and n in an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step. The latter includes irradiating the excited molecules by a second infrared laser in order to convert the excited molecules into a separable product, or also by chemically converting the excited molecules, preferably by reaction with a gaseous reactant

  12. Synthesis of acyl carbamates via four component Pd-catalyzed carbonylative coupling of aryl halides, potassium cyanate, and alcohols.

    Science.gov (United States)

    Yin, Hongfei; de Almeida, Angelina M; de Almeida, Mauro V; Lindhardt, Anders T; Skrydstrup, Troels

    2015-03-06

    A simple and mild method is demonstrated for assembling acyl carbamates through a base-free four-component Pd-catalyzed carbonylation of aryl halides in the presence of potassium cyanate and alcohols in a two-chamber system. This approach produces a wide range of aryl acyl carbamates in good to excellent yields from the corresponding aryl bromides or iodides with near-stoichiometric carbon monoxide. In addition, the method can be extended to the synthesis of primary amides thereby expanding the usefulness of cyanate as an ammonia equivalent.

  13. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1983-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure, particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  14. Deuterium isotope separation

    International Nuclear Information System (INIS)

    Benson, S.W.

    1979-01-01

    Deuterium-containing molecules are separated and enriched by exposing commercially available ethylene, vinyl chloride, 1,2-dichloroethane or propylene to the radiation of tuned infrared lasers to selectively decompose these compounds into enriched molecular products containing deuterium atoms. The deuterium containing molecules can be easily separated from the starting material by absorption, distillation or other simple chemical separation techniques and methods. After evaporation such deuterium containing molecules can be burned to form water with an enriched deuterium content or pyrolyzed to form hydrogen gas with an enriched deuterium content. (author)

  15. Chromatographic hydrogen isotope separation

    Science.gov (United States)

    Aldridge, F.T.

    Intermetallic compounds with the CaCu/sub 5/ type of crystal structure, particularly LaNiCo/sub 4/ and CaNi/sub 5/, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen cn produce large quantities of heavy water at an effective cost for use in heavy water reactors.

  16. Isotope separation using lasers

    International Nuclear Information System (INIS)

    Guers, K.

    1976-01-01

    In laser isotope separation atoms or molecules of a specific isotopic species are selectively excited in a gaseous mixture by means of laser light and then separated from the mixture by physical or chemical methods. The methods of excitation and separation are described and compared in terms of their effectiveness. The use of molecules is investigated by analysing the possibility of the selective excitation of UF 6 . Finally, developments in this field are discussed together with the cost of research incurred in the United States and the economic benefit expected from this research. (author)

  17. Ultrasonic pretreatment for lipase-catalyed synthesis of phytosterol esters with different acyl donors.

    Science.gov (United States)

    Zheng, Ming-Ming; Wang, Lian; Huang, Feng-Hong; Dong, Ling; Guo, Ping-Mei; Deng, Qian-Chun; Li, Wen-Lin; Zheng, Chang

    2012-09-01

    This study is focused on the enzymatic esterification of phytosterols with different acyl donors to produce the corresponding phytosterol esters catalyzed by Canadia sp. 99-125 lipase under ultrasound irradiation. An ultrasonic frequency of 35 kHz, power of 200 W and time of 1h was determined to guarantee satisfactory degree of esterification and lipase activity. The influence of temperature, substrates concentration and molar ratio was investigated subsequently. The optimum production was achieved in isooctane system at 60°C with phytosterol concentration of 150 μmol/mL and phytosterol to fatty acid molar ratio of 1:1.5, resulting in a phytosterol esters conversion of above 85.7% in short reaction time (8h). Phytosterols esters could also be converted in high yields to the corresponding long-chain acyl esters via transesterification with triacylglycerols (above 90.3%) under ultrasound irradiation. In optimum conditions, the overall esterification reaction rate using the ultrasonic pretreatment process was above 2-fold than that of mechanical stirring process without damage the lipase activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Lipase-catalyzed biodiesel production with methyl acetate as acyl acceptor

    Energy Technology Data Exchange (ETDEWEB)

    Huang Ying; Yan Yunjun [School of Life Science and Technology, Huazhong Univ. of Science and Technology, Wuhan (China)

    2008-03-15

    Biodiesel is an alternative diesel fuel made from renewable biological resources. During the process of biodiesel production, lipase-catalyzed transesterification is a crucial step. However, current techniques using methanol as acyl acceptor have lower enzymatic activity; this limits the application of such techniques in large-scale biodiesel production. Furthermore, the lipid feedstock of currently available techniques is limited. In this paper, the technique of lipase-catalyzed transesterification of five different oils for biodiesel production with methyl acetate as acyl acceptor was investigated, and the transesterification reaction conditions were optimized. The operation stability of lipase under the obtained optimal conditions was further examined. The results showed that under optimal transesterification conditions, both plant oils and animal fats led to high yields of methyl ester: cotton-seed oil, 98%; rape-seed oil, 95%; soybean oil, 91%; tea-seed oil, 92%; and lard, 95%. Crude and refined cotton-seed oil or lard made no significant difference in yields of methyl ester. No loss of enzymatic activity was detected for lipase after being repeatedly used for 40 cycles (ca. 800 h), which indicates that the operational stability of lipase was fairly good under these conditions. Our results suggest that cotton-seed oil, rape-seed oil and lard might substitute soybean oil as suitable lipid feedstock for biodiesel production. Our results also show that our technique is fit for various lipid feedstocks both from plants and animals, and presents a very promising way for the large-scale biodiesel production. (orig.)

  19. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Science.gov (United States)

    Biresaw, Girma; Gordon, Sherald

    2018-01-01

    Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis) plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity. PMID:29484216

  20. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Directory of Open Access Journals (Sweden)

    Rogers E. Harry-O’kuru

    2018-01-01

    Full Text Available Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity.