Effect of the Protection of the Residual Aminopropyl Groups of a Chiral Stationary Phase Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid on the Chiral Resolution Behaviors

International Nuclear Information System (INIS)

Hyun, Myung Ho; Kim, Young Hwa; Cho, Yoon Jae

2004-01-01

The protection of the unreacted residual aminopropyl groups of CSP 2 was found to improve the retention and the resolution factors for the resolution of racemic compounds containing a primary amino group. However, the size of the protecting acyl group should not be too bulky. As a protecting acyl group, acetyl or butyryl group seems to be good enough for the improved retention and the improved resolution. However, the separation factors were found to decrease slightly when the unreacted residual aminopropyl groups of the CSP are protected by an acyl group.

Effect of the Protection of the Residual Aminopropyl Groups of a Chiral Stationary Phase Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid on the Chiral Resolution Behaviors

Energy Technology Data Exchange (ETDEWEB)

Hyun, Myung Ho; Kim, Young Hwa; Cho, Yoon Jae [Pusan National University, Busan (Korea, Republic of)

2004-03-15

The protection of the unreacted residual aminopropyl groups of CSP 2 was found to improve the retention and the resolution factors for the resolution of racemic compounds containing a primary amino group. However, the size of the protecting acyl group should not be too bulky. As a protecting acyl group, acetyl or butyryl group seems to be good enough for the improved retention and the improved resolution. However, the separation factors were found to decrease slightly when the unreacted residual aminopropyl groups of the CSP are protected by an acyl group.

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.

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

International Nuclear Information System (INIS)

Roughan, G.; Nishida, I.

1990-01-01

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

Commelinid Monocotyledon Lignins Are Acylated by p-Coumarate1[OPEN

Science.gov (United States)

Free, Heather C.A.; Smith, Bronwen G.

2018-01-01

Commelinid monocotyledons are a monophyletic clade differentiated from other monocotyledons by the presence of cell wall-bound ferulate and p-coumarate. The Poaceae, or grass family, is a member of this group, and most of the p-coumarate in the cell walls of this family acylates lignin. Here, we isolated and examined lignified cell wall preparations from 10 species of commelinid monocotyledons from nine families other than Poaceae, including species from all four commelinid monocotyledon orders (Poales, Zingiberales, Commelinales, and Arecales). We showed that, as in the Poaceae, lignin-linked p-coumarate occurs exclusively on the hydroxyl group on the γ-carbon of lignin unit side chains, mostly on syringyl units. Although the mechanism of acylation has not been studied directly in these species, it is likely to be similar to that in the Poaceae and involve BAHD acyl-coenzyme A:monolignol transferases. PMID:29724771

Room-Temperature Alternative to the Arbuzov Reaction: The Reductive Deoxygenation of Acyl Phosphonates

OpenAIRE

Kedrowski, Sean M. A.; Dougherty, Dennis A.

2010-01-01

The reductive deoxygenation of acyl phosphonates using a Wolff−Kishner-like sequence is described. This transformation allows direct access to alkyl phosphonates from acyl phosphonates at room temperature. The method can be combined with acyl phosphonate synthesis into a one pot, four-step procedure for the conversion of carboxylic acids into alkyl phosphonates. The methodology works well for a variety of aliphatic acids and shows a functional group tolerance similar to that of other hydrazon...

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.

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

Science.gov (United States)

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

2016-02-22

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

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...

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

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.

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.

Characterization of Lipid A Variants by Energy-Resolved Mass Spectrometry: Impact of Acyl Chains

Science.gov (United States)

Crittenden, Christopher M.; Akin, Lucas D.; Morrison, Lindsay J.; Trent, M. Stephen; Brodbelt, Jennifer S.

2017-06-01

Lipid A molecules consist of a diglucosamine sugar core with a number of appended acyl chains that vary in their length and connectivity. Because of the challenging nature of characterizing these molecules and differentiating between isomeric species, an energy-resolved MS/MS strategy was undertaken to track the fragmentation trends and map genealogies of product ions originating from consecutive cleavages of acyl chains. Generalizations were developed based on the number and locations of the primary and secondary acyl chains as well as variations in preferential cleavages arising from the location of the phosphate groups. Secondary acyl chain cleavage occurs most readily for lipid A species at the 3' position, followed by primary acyl chain fragmentation at both the 3' and 3 positions. In the instances of bisphosphorylated lipid A variants, phosphate loss occurs readily in conjunction with the most favorable primary and secondary acyl chain cleavages. [Figure not available: see fulltext.

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

International Nuclear Information System (INIS)

Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

2015-01-01

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

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.

A soluble fatty acyl-acyl carrier protein synthetase from the bioluminescent bacterium Vibrio harveyi.

Science.gov (United States)

Byers, D M; Holmes, C G

1990-01-01

An enzyme catalyzing the ligation of long chain fatty acids to bacterial acyl carrier protein (ACP) has been detected and partially characterized in cell extracts of the bioluminescent bacterium Vibrio harveyi. Acyl-ACP synthetase activity (optimal pH 7.5-8.0) required millimolar concentrations of ATP and Mg2+ and was slightly activated by Ca2+, but was inhibited at high ionic strength and by Triton X-100. ACP from either Escherichia coli (apparent Km = 20 microM) or V. harveyi was used as a substrate. Of the [14C]fatty acids tested as substrates (8-18 carbons), a preference for fatty acids less than or equal to 14 carbons in length was observed. Vibrio harveyi acyl-ACP synthetase appears to be a soluble hydrophilic enzyme on the basis of subcellular fractionation and Triton X-114 phase partition assay. The enzyme was not coinduced with luciferase activity or light emission in vivo during the late exponential growth phase in liquid culture. Acyl-ACP synthetase activity was also detected in extracts from the luminescent bacterium Vibrio fischeri, but not Photobacterium phosphoreum. The cytosolic nature and enzymatic properties of V. harveyi acyl-ACP synthetase indicate that it may have a different physiological role than the membrane-bound activity of E. coli, which has been implicated in phosphatidylethanolamine turnover. Acyl-ACP synthetase activity in V. harveyi could be involved in the intracellular activation and elongation of exogenous fatty acids that occurs in this species or in the reactivation of free myristic acid generated by luciferase.

Gas-phase acylation of aminopropyl-silica gel in the synthesis of some chemically bonded silica materials for analytical applications

International Nuclear Information System (INIS)

Basiuk, Vladimir; Khil'chevskaya, E.G.

1991-01-01

Gas-phase acylation of aminopropyl-silica gel with aliphatic dicarboxylic (succinic, adipic and sebacic) and 4-aminobenzoic acids is proposed as a rapid and efficient one-step method for the synthesis of carboxyalkyl- and 4-aminophenylamidopropyl-silica gels, usually used as zwitterion exchangers for liquid chromatography and matrices for multi-step syntheses of silica-bound aromatic azo reagents for the sorption and chromatographic separation of metal ions. Acylation degrees of 59-90% are achieved after 0.5 h. IR spectra of the acylation products and near-UV-visible spectra for bonded aromatic azo compounds, based on 4-aminobenzamidopropyl-silica gel, are presented. Some positive and negative aspects of the gas-phase acylation are discussed. (author). 34 refs.; 2 figs.; 2 tabs

Friedel-Crafts Acylation with Amides

Science.gov (United States)

Raja, Erum K.; DeSchepper, Daniel J.; Nilsson Lill, Sten O.; Klumpp, Douglas A.

2012-01-01

Friedel-Crafts acylation has been known since the 1870s and it is an important organic synthetic reaction leading to aromatic ketone products. Friedel-Crafts acylation is usually done with carboxylic acid chlorides or anhydrides while amides are generally not useful substrates in these reactions. Despite being the least reactive carboxylic acid derivative, we have found a series of amides capable of providing aromatic ketones in good yields (55–96%, 17 examples). We propose a mechanism involving diminished C-N resonance through superelectrophilic activation and subsequent cleavage to acyl cations. PMID:22690740

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......-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...... 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...

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

Science.gov (United States)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Adriana Cristofano

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

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...

Acylated ghrelin concentrations are markedly decreased during pregnancy in mothers with and without gestational diabetes: relationship with cholinesterase.

Science.gov (United States)

Tham, Elaine; Liu, Jianhua; Innis, Sheila; Thompson, David; Gaylinn, Bruce D; Bogarin, Roberto; Haim, Alon; Thorner, Michael O; Chanoine, Jean-Pierre

2009-05-01

Acylated (octanoylated) ghrelin stimulates food intake and growth hormone secretion and is deacylated into desacyl ghrelin by butyrylcholinesterase. Acylated and desacyl ghrelin both promote adipogenesis. Ghrelin concentrations decrease with hyperglycemia and hyperinsulinism. We hypothesized that 1) acylated ghrelin increases during pregnancy, contributing positively to energy balance, but is lower in women with gestational diabetes and 2) butyrylcholinesterase activity is inversely correlated with acylated ghrelin concentrations. In a first group of subjects, using two-site sandwich ghrelin assays that specifically detect full-length forms, we investigated women with and without gestational diabetes (n = 14/group) during pregnancy and after delivery. We examined whether changes in ghrelin during a test meal were correlated with changes in pituitary growth hormone [assessed through calculation of the area under the curve (AUC) during the test meal]. In postpartum subjects, the percent of total ghrelin that is acylated was four to five times higher than previously observed using single antibody assays. During pregnancy, acylated ghrelin concentrations (mean +/- SE) were lower compared with the postpartum period throughout the meal (AUC 1.2 +/- 0.2 vs. 10.2 +/- 1.9 ng.ml(-1).90 min(-1), P < 0.001). In the postpartum, acylated ghrelin and growth hormone were positively correlated (r = 0.50, P = 0.007). Desacyl (but not acylated) ghrelin was increased in subjects with gestational diabetes during and after pregnancy (AUC 15.4 +/- 1.9 vs. 8.6 +/- 1.2 ng.ml(-1).90 min(-1), P = 0.005). In a second group of subjects (n = 13), acylated ghrelin was similarly suppressed during pregnancy. Circulating octanoate concentrations (3.1 +/- 0.5 vs. 4.5 +/- 0.6 microg/ml, P = 0.029) and cholinesterase activity (705 +/- 33 vs. 1,013 +/- 56 U/ml, P < 0.001) were lower during pregnancy compared with the postpartum period. In conclusion, acylated ghrelin markedly decreases during pregnancy

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.

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.

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.

Some Chemical Group Separations of Radioactive Trace Elements

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K

1962-06-15

As a pretreatment for gamma spectrometric analysis methods have been developed for the chemical separation of traces of P, Sc, Ge, As, Se, Br, Zr, Nb, Ru, Ag, Cd, Sn, Sb, I, Hf, Ta, Re, Os, Au and Hg into 9 different groups. By combining the present methods with already existing chemical group separation methods for traces of Na, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Mo, In, Fe, Cs, Ba, L.a, the rare earths, W and Ir, a complete separation scheme comprising 15 groups of elements has been worked out. The chemical 15-group separation method has been advantageously used in gamma spectrometric routine analysis of biological materials.

Some Chemical Group Separations of Radioactive Trace Elements

International Nuclear Information System (INIS)

Samsahl, K.

1962-06-01

As a pretreatment for gamma spectrometric analysis methods have been developed for the chemical separation of traces of P, Sc, Ge, As, Se, Br, Zr, Nb, Ru, Ag, Cd, Sn, Sb, I, Hf, Ta, Re, Os, Au and Hg into 9 different groups. By combining the present methods with already existing chemical group separation methods for traces of Na, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Mo, In, Fe, Cs, Ba, L.a, the rare earths, W and Ir, a complete separation scheme comprising 15 groups of elements has been worked out. The chemical 15-group separation method has been advantageously used in gamma spectrometric routine analysis of biological materials

Acylated flavone glycosides from Veronica

DEFF Research Database (Denmark)

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

2003-01-01

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

Acyl-CoA metabolism and partitioning

DEFF Research Database (Denmark)

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

2014-01-01

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...

Photoaffinity Labeling of Developing Jojoba Seed Microsomal Membranes with a Photoreactive Analog of Acyl-Coenzyme A (Acyl-CoA) (Identification of a Putative Acyl-CoA:Fatty Alcohol Acyltransferase.

Science.gov (United States)

Shockey, J. M.; Rajasekharan, R.; Kemp, J. D.

1995-01-01

Jojoba (Simmondsia chinensis, Link) is the only plant known that synthesizes liquid wax. The final step in liquid wax biosynthesis is catalyzed by an integral membrane enzyme, fatty acyl-coenzyme A (CoA):fatty alcohol acyltransferase, which transfers an acyl chain from acyl-CoA to a fatty alcohol to form the wax ester. To purify the acyltransferase, we have labeled the enzyme with a radioiodinated, photoreactive analog of acyl-CoA, 12-[N-(4-azidosalicyl)amino] dodecanoyl-CoA (ASD-CoA). This molecule acts as an inhibitor of acyltransferase activity in the dark and as an irreversible inhibitor upon exposure to ultraviolet light. Oleoyl-CoA protects enzymatic activity in a concentration-dependent manner. Photolysis of microsomal membranes with labeled ASD-CoA resulted in strong labeling of two polypeptides of 57 and 52 kD. Increasing concentrations of oleoyl-CoA reduced the labeling of the 57-kD polypeptide dramatically, whereas the labeling of the 52-kD polypeptide was much less responsive to oleoyl-CoA. Also, unlike the other polypeptide, the labeling of the 57-kD polypeptide was enhanced considerably when photolyzed in the presence of dodecanol. These results suggest that a 57-kD polypeptide from jojoba microsomes may be the acyl-CoA:fatty alcohol acyltransferase.

Analytische und Effektor-Studien von N-Acyl-Ethanolaminphosphaten

OpenAIRE

Ates, Ebru

2011-01-01

Bei N-Acyl-Ethanolaminphosphaten handelt es sich um eine bislang wenig untersuchte Klasse polarer Substanzen, deren Erforschung aufgrund ihrer strukturellen Analogie zu apolaren, physiologisch wirksamen N-Acyl-Ethanolaminen von Interesse ist. Zu bear-beiten waren analytische Fragestellungen, die auch synthetische Aufgaben beinhalteten, wie Methodenentwicklung und Versuche zur Erfassung von N-Acyl-Ethanolamin-phosphaten in ausgewählten Lebensmitteln sowie strukturelle Studien zur „Bioaktivität...

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.

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.

Phase separation in lipid bilayers triggered by low pH

International Nuclear Information System (INIS)

Suresh, Swetha; Edwardson, J. Michael

2010-01-01

Research highlights: → Lipid bilayers have been imaged by atomic force microscopy (AFM). → At pH 5 phase separation occurs in lipid bilayers containing mixed acyl chains. → Phase separation does not occur when lipids have only unsaturated chains. → Phase separation might drive protein clustering during endocytosis. -- Abstract: Endocytosis involves the capture of membrane from the cell surface in the form of vesicles, which become rapidly acidified to about pH 5. Here we show using atomic force microscopy (AFM) imaging that this degree of acidification triggers phase separation in lipid bilayers containing mixed acyl chains (e.g. palmitoyl/oleoyl) or complex mixtures (e.g. total brain extract) but not in bilayers containing only lipids with unsaturated chains (e.g. dioleoyl). Since mixed-chain lipids are major constituents of the outer leaflet of the plasma membrane, the type of phase separation reported here might support protein clustering and signaling during endocytosis.

Plasma levels of acylated ghrelin in patients with functional dyspepsia

Science.gov (United States)

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

2012-01-01

AIM: To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia. METHODS: Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study. The functional dyspepsia patients were each diagnosed based on the Rome III criteria. Eligible patients completed a questionnaire concerning the severity of 10 symptoms. Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit; electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal. RESULTS: There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia. However, in patients with functional dyspepsia, there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain (r = -0.427, P = 0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety (r = 0.428, P =0.047). Additionally, there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria (%) (r = -0.522, P = 0.013). Interestingly, two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal. CONCLUSION: Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia. PMID:22611317

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.

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...... of a wide range of aryl ketones in good yields and in short reaction times with minimum amounts of waste...

N-Acylated and d Enantiomer Derivatives of a Nonamer Core Peptide of Lactoferricin B Showing Improved Antimicrobial Activity

OpenAIRE

Wakabayashi, Hiroyuki; Matsumoto, Hiroshi; Hashimoto, Koichi; Teraguchi, Susumu; Takase, Mitsunori; Hayasawa, Hirotoshi

1999-01-01

N-acylated or d enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

N-Acylated and D enantiomer derivatives of a nonamer core peptide of lactoferricin B showing improved antimicrobial activity.

Science.gov (United States)

Wakabayashi, H; Matsumoto, H; Hashimoto, K; Teraguchi, S; Takase, M; Hayasawa, H

1999-05-01

N-acylated or D enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

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

International Nuclear Information System (INIS)

Carey, L.M.; Rodriguez, A.; Meighen, E.

1984-01-01

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

Activation of Exogenous Fatty Acids to Acyl-Acyl Carrier Protein Cannot Bypass FabI Inhibition in Neisseria*

Science.gov (United States)

Yao, Jiangwei; Bruhn, David F.; Frank, Matthew W.; Lee, Richard E.; Rock, Charles O.

2016-01-01

Neisseria is a Gram-negative pathogen with phospholipids composed of straight chain saturated and monounsaturated fatty acids, the ability to incorporate exogenous fatty acids, and lipopolysaccharides that are not essential. The FabI inhibitor, AFN-1252, was deployed as a chemical biology tool to determine whether Neisseria can bypass the inhibition of fatty acid synthesis by incorporating exogenous fatty acids. Neisseria encodes a functional FabI that was potently inhibited by AFN-1252. AFN-1252 caused a dose-dependent inhibition of fatty acid synthesis in growing Neisseria, a delayed inhibition of growth phenotype, and minimal inhibition of DNA, RNA, and protein synthesis, showing that its mode of action is through inhibiting fatty acid synthesis. Isotopic fatty acid labeling experiments showed that Neisseria encodes the ability to incorporate exogenous fatty acids into its phospholipids by an acyl-acyl carrier protein-dependent pathway. However, AFN-1252 remained an effective antibacterial when Neisseria were supplemented with exogenous fatty acids. These results demonstrate that extracellular fatty acids are activated by an acyl-acyl carrier protein synthetase (AasN) and validate type II fatty acid synthesis (FabI) as a therapeutic target against Neisseria. PMID:26567338

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.

Safety design guides for grouping and separation for CANDU 9

International Nuclear Information System (INIS)

Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young; A. C. D. Wright

1996-03-01

This safety design guide for grouping and separation describes the philosophy of physical and functional separation for systems, structures and components in CANDU 9 plants and provides the requirements for the implementation of the philosophy in the detailed plant design. The separation of the safety systems is to ensure that common cause events and functional interconnections between systems do not impair the capability to perform the required safety functions for accident conditions. The separation requirements are also applied to the design by grouping the plant systems into two basic groups. Group 1 includes the power production systems and Group 2 includes the safety related systems required for the mitigation of serious process failure. The Group 2 is further separated into subgroups to ensure that events that could cause failure of a special safety system in one subgroup can be mitigated by the other subgroup. The change status for the regulatory requirements, code and standards should be traced and this safety design guide shall be updated accordingly. 2 tabs., 6 figs. (Author) .new

Safety design guides for grouping and separation for CANDU 9

Energy Technology Data Exchange (ETDEWEB)

Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of); Wright, A C.D. [Atomic Energy of Canada Ltd., Toronto (Canada)

1996-03-01

This safety design guide for grouping and separation describes the philosophy of physical and functional separation for systems, structures and components in CANDU 9 plants and provides the requirements for the implementation of the philosophy in the detailed plant design. The separation of the safety systems is to ensure that common cause events and functional interconnections between systems do not impair the capability to perform the required safety functions for accident conditions. The separation requirements are also applied to the design by grouping the plant systems into two basic groups. Group 1 includes the power production systems and Group 2 includes the safety related systems required for the mitigation of serious process failure. The Group 2 is further separated into subgroups to ensure that events that could cause failure of a special safety system in one subgroup can be mitigated by the other subgroup. The change status for the regulatory requirements, code and standards should be traced and this safety design guide shall be updated accordingly. 2 tabs., 6 figs. (Author) .new.

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.

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.

A high-performance liquid chromatography-based radiometric assay for acyl-CoA:alcohol transacylase from jojoba.

Science.gov (United States)

Garver, W S; Kemp, J D; Kuehn, G D

1992-12-01

Acyl-CoA:alcohol transacylase catalyzes the final step in the biosynthesis of storage liquid wax esters from acyl-CoA fatty acids and fatty alcohols in a limited number of microbes, algae, and Simmondsia chinensis Link (jojoba). An improved and automated method of enzyme assay for this catalyst from cotyledons of jojoba is described. The assay method uses reversed-phase C18 high performance liquid chromatography (HPLC) to separate the labeled C30:1 liquid wax product, [14C]-dodecanyl-octadecenoate, from the unreacted substrate, [14C]octadecenoyl-CoA (oleyl-CoA), and other components produced from enzymes present in the crude homogenate of jojoba cotyledons, including [14C]-octadecenoic acid (oleic acid) and [14C]octadecenol (oleyol). Methods are also described for microscale chemical synthesis in one vessel of 14C-radiolabeled substrates and products for the transacylase. These labeled reagents are required to confirm the HPLC separations of reaction products. The radioactive components are quantitated using an on-line flow-through scintillation detector enabling sensitive and precise analysis of the reaction products.

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

International Nuclear Information System (INIS)

Meutia Fadhilah Hasibuan; Mohd Wahid Samsudin; Rahimi Mohd Yusop; Suria Ramli

2015-01-01

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

Striving towards improved Friedel-Crafts acylation catalysts

International Nuclear Information System (INIS)

Scott, N.M.; Deacon, G.B.

1998-01-01

Full text: Lanthanum, ytterbium and scandium salts of trifluoromethanesulfonic acid have been shown to act as promising Lewis acid catalysts for the Friedel-Craft acylation reactions. In our study catalytic acylation of anisole by acetic anhydride in nitroethane was investigated. Yields were determined after extraction of para-methoxyacetophenone from the reaction mixture by G.L.C using the external standardisation method. Anhydrous lanthanoid tris-triflate salts [Ln(O 3 SCF 3 ) 3 , Ln La, Y, Nd, Eu and Yb] were initially investigated as catalysts. Ytterbium tris-triflate was found to be the most effective giving ∼90% of the acylation product. The hydrated lanthanide tris-nitrate salts [Ln(NO 3 ) 3 .nH 2 O, Ln = La, Nd, Eu and Yb] were also investigated using in situ dehydration with acetic anhydride. These were found to have low solubility in the reaction mixture and gave poor yields of para-methoxyacetophenone. The formation of side products was suggested by the low total recovery of anisole and para-methoxyacetophenone. The blocking of coordination sites of these catalysts by tetraglyme resulted in a 50% reduction in acylation activity compared with the simple salt. Addition of Li(O 3 SCF 3 ) to Ln(O 3 SCF 3 ) 3 catalysts (ratio of 4:1)had only a slight accelerating effect on the Friedel-Crafts acylation reaction and the yield was only marginally greater than that in the absence of the added salt. In contrast Li(ClO 4 ) dramatically decreased reaction times and improved the yield of para-methoxyace-tophenone, as recently reported

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.

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

International Nuclear Information System (INIS)

Serek, Robert; Forwood, Jade K.; Hume, David A.; Martin, Jennifer L.; Kobe, Bostjan

2006-01-01

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

Flow chemistry and polymer-supported pseudoenantiomeric acylating agents enable parallel kinetic resolution of chiral saturated N-heterocycles

Science.gov (United States)

Kreituss, Imants; Bode, Jeffrey W.

2017-05-01

Kinetic resolution is a common method to obtain enantioenriched material from a racemic mixture. This process will deliver enantiopure unreacted material when the selectivity factor of the process, s, is greater than 1; however, the scalemic reaction product is often discarded. Parallel kinetic resolution, on the other hand, provides access to two enantioenriched products from a single racemic starting material, but suffers from a variety of practical challenges regarding experimental design that limit its applications. Here, we describe the development of a flow-based system that enables practical parallel kinetic resolution of saturated N-heterocycles. This process provides access to both enantiomers of the starting material in good yield and high enantiopurity; similar results with classical kinetic resolution would require selectivity factors in the range of s = 100. To achieve this, two immobilized quasienantiomeric acylating agents were designed for the asymmetric acylation of racemic saturated N-heterocycles. Using the flow-based system we could efficiently separate, recover and reuse the polymer-supported reagents. The amide products could be readily separated and hydrolysed to the corresponding amines without detectable epimerization.

The stereochemistry of the addition of chlorotitanium enolates of N-acyl oxazolidin-2-ones to 5- and 6- membered N-acyliminium ions

Directory of Open Access Journals (Sweden)

Pilli Ronaldo A.

2001-01-01

Full Text Available The stereoselective addition of chiral and achiral titanium enolates derived from the corresponding N-acyl oxazolidin-2-ones to 5- and 6- membered N-acyliminium ions afforded 2-substituted pyrrolidines in moderate to good diastereoisomeric ratio (5:1 to 14:1 while lower diastereoselection was generally observed in the formation of the corresponding 2-substituted piperidines. The stereochemical outcome was found to be modulated by the nature of the cyclic N-acyliminium ion (5- or 6-membered and of its carbamate and by the N-acyl group in the enolate precursor. The preferential lk approach seems to be dictated mainly by the minimization of non-bonding interactions between the N-acyl group in the chlorotitanium (IV enolate and the carbamate and methylene groups in the cyclic N-acyliminium ion.

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...

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

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.

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-ATs w...

Acyl-CoA binding protein and epidermal barrier function

DEFF Research Database (Denmark)

Bloksgaard, Maria; Neess, Ditte; Færgeman, Nils J

2014-01-01

The acyl-CoA binding protein (ACBP) is a 10kDa intracellular protein expressed in all eukaryotic species and mammalian tissues investigated. It binds acyl-CoA esters with high specificity and affinity and is thought to act as an intracellular transporter of acyl-CoA esters between different...... includes tousled and greasy fur, development of alopecia and scaling of the skin with age. Furthermore, epidermal barrier function is compromised causing a ~50% increase in transepidermal water loss relative to that of wild type mice. Lipidomic analyses indicate that this is due to significantly reduced...

A novel approach for over-expression, characterization, and isotopic enrichment of a homogeneous species of acyl carrier protein from Plasmodium falciparum

International Nuclear Information System (INIS)

Sharma, Shailendra Kumar; Modak, Rahul; Sharma, Shilpi; Sharma, Alok Kumar; Sarma, Siddhartha P.; Surolia, Avadhesha; Surolia, Namita

2005-01-01

Acyl carrier protein (ACP) plays a central role in fatty acid biosynthesis by transferring the acyl groups from one enzyme to another for the completion of the fatty acid synthesis cycle. Holo-ACP is the obligatory substrate for the synthesis of acyl-ACPs which act as the carrier and donor for various metabolic reactions. Despite its interactions with numerous proteins in the cell, its mode of interaction is poorly understood. Here, we report the over-expression of PfACP in minimal medium solely in its holo form and in high yield. Expression in minimal media provides a means to isotopically label PfACP for high resolution multi-nuclear and multi-dimensional NMR studies. Indeed, the proton-nitrogen correlated NMR spectrum exhibits very high chemical shift dispersion and resolution. We also show that holo-PfACP thus expressed is amenable to acylation reactions using Escherichia coli acyl-ACP synthetase as well as by standard chemical methods

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-...

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...

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.

Acyl Meldrum's acid derivatives: application in organic synthesis

Science.gov (United States)

Janikowska, K.; Rachoń, J.; Makowiec, S.

2014-07-01

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

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

Science.gov (United States)

Raboune, Siham; Stuart, Jordyn M.; Leishman, Emma; Takacs, Sara M.; Rhodes, Brandon; Basnet, Arjun; Jameyfield, Evan; McHugh, Douglas; Widlanski, Theodore; Bradshaw, Heather B.

2014-01-01

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. PMID:25136293

Rivastigmine Improves Appetite by Increasing the Plasma Acyl/Des-Acyl Ghrelin Ratio and Cortisol in Alzheimer Disease

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Yoshiko Furiya

2018-03-01

Full Text Available Background: Weight loss accelerates cognitive decline and increases mortality in patients with dementia. While acetylcholinesterase (AChE inhibitors are known to cause appetite loss, we sometimes encounter patients in whom switching from donepezil (AChE inhibitor to rivastigmine (AChE and butyrylcholinesterase [BuChE] inhibitor improves appetite. Since BuChE inactivates ghrelin, a potent orexigenic hormone, we speculated that rivastigmine improves appetite by inhibiting BuChE-mediated ghrelin inactivation. Methods: The subjects were patients with mild to moderate Alzheimer disease treated with either rivastigmine patch (n = 11 or donepezil (n = 11 for 6 months. Before and after treatment, we evaluated appetite (0, decreased; 1, slightly decreased; 2, normal; 3, slightly increased; 4, increased, cognitive function, and blood biochemical variables, including various hormones. Results: Rivastigmine treatment significantly improved appetite (from 1.6 ± 0.5 to 2.6 ± 0.7, whereas donepezil treatment did not (from 2.0 ± 0.0 to 1.8 ± 0.4. Simultaneously, rivastigmine, but not donepezil, significantly decreased the serum cholinesterase activity (from 304.3 ± 60.5 to 246.8 ± 78.5 IU/L and increased the cortisol level (from 11.86 ± 3.12 to 14.61 ± 3.29 μg/dL and the acyl/des-acyl ghrelin ratio (from 4.03 ± 2.96 to 5.28 ± 2.72. The levels of leptin, insulin, total ghrel­in, and cognitive function were not significantly affected by either treatment. Conclusions: Our results suggest that compared with donepezil, rivastigmine has the advantage of improving appetite by increasing the acyl/des-acyl ghrelin ratio and cortisol level, thereby preventing weight loss.

Purification, crystallization and preliminary crystallographic analysis of very-long-chain acyl-CoA dehydrogenase from Caenorhabditis elegans

International Nuclear Information System (INIS)

Li, Zhijie; Zhai, Yujia; Fang, Junnan; Zhou, Qiangjun; Geng, Yunqi; Sun, Fei

2010-01-01

Very-long-chain acyl-CoA dehydrogenase from Caenorhabditis elegans (cVLCAD) has been crystallized in space group C2 and its X-ray diffraction data set has been collected to 1.6 Å resolution. Unlike other VLCADs that were reported to form dimers, the purified cVLCAD was found as a homotetrameric protein according to static light-scattering measurements. Acyl-CoA dehydrogenase [acyl-CoA:(acceptor) 2,3-oxidoreductase; EC 1.3.99.3] catalyzes the first reaction step in mitochondrial fatty-acid β-oxidation. Here, the very-long-chain acyl-CoA dehydrogenase from Caenorhabditis elegans (cVLCAD) has been cloned and overexpressed in Escherichia coli strain BL21 (DE3). Interestingly, unlike other very-long-chain acyl-CoA dehydrogenases, cVLCAD was found to form a tetramer by size-exclusion chromatography coupled with in-line static light-scattering, refractive-index and ultraviolet measurements. Purified cVLCAD (12 mg ml −1 ) was successfully crystallized by the hanging-drop vapour-diffusion method under conditions containing 100 mM Tris–HCl pH 8.0, 150 mM sodium chloride, 200 mM magnesium formate and 13% PEG 3350. The crystal has a tetragonal form and a complete diffraction data set was collected and processed to 1.8 Å resolution. The crystal belonged to space group C2, with unit-cell parameters a = 138.6, b = 116.7, c = 115.3 Å, α = γ = 90.0, β = 124.0°. A self-rotation function indicated the existence of one noncrystallographic twofold axis. A preliminary molecular-replacement solution further confirmed the presence of two molecules in one asymmetric unit, which yields a Matthews coefficient V M of 2.76 Å 3 Da −1 and a solvent content of 55%

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

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Anna Martirosyan

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

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...

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.

Acyl transfer from membrane lipids to peptides is a generic process.

Science.gov (United States)

Dods, Robert H; Bechinger, Burkhard; Mosely, Jackie A; Sanderson, John M

2013-11-15

The generality of acyl transfer from phospholipids to membrane-active peptides has been probed using liquid chromatography-mass spectrometry analysis of peptide-lipid mixtures. The peptides examined include melittin, magainin II, PGLa, LAK1, LAK3 and penetratin. Peptides were added to liposomes with membrane lipid compositions ranging from pure phosphatidylcholine (PC) to mixtures of PC with phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol. Experiments were typically conducted at pH7.4 at modest salt concentrations (90 mM NaCl). In favorable cases, lipidated peptides were further characterized by tandem mass spectrometry methods to determine the sites of acylation. Melittin and magainin II were the most reactive peptides, with significant acyl transfer detected under all conditions and membrane compositions. Both peptides were lipidated at the N-terminus by transfer from PC, phosphatidylethanolamine, phosphatidylserine or phosphatidylglycerol, as well as at internal sites: lysine for melittin; serine and lysine for magainin II. Acyl transfer could be detected within 3h of melittin addition to negatively charged membranes. The other peptides were less reactive, but for each peptide, acylation was found to occur in at least one of the conditions examined. The data demonstrate that acyl transfer is a generic process for peptides bound to membranes composed of diacylglycerophospholipids. Phospholipid membranes cannot therefore be considered as chemically inert toward peptides and by extension proteins. © 2013. Published by Elsevier Ltd. All rights reserved.

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

Fatty Acyl Chains of Mycobacterium marinum Lipooligosaccharides

Science.gov (United States)

Rombouts, Yoann; Alibaud, Laeticia; Carrère-Kremer, Séverine; Maes, Emmanuel; Tokarski, Caroline; Elass, Elisabeth; Kremer, Laurent; Guérardel, Yann

2011-01-01

We have recently established the fine structure of the glycan backbone of lipooligosaccharides (LOS-I to LOS-IV) isolated from Mycobacterium marinum, a close relative of Mycobacterium tuberculosis. These studies culminated with the description of an unusual terminal N-acylated monosaccharide that confers important biological functions to LOS-IV, such as macrophage activation, that may be relevant to granuloma formation. It was, however, also suggested that the lipid moiety was required for LOSs to exert their immunomodulatory activity. Herein, using highly purified LOSs from M. marinum, we have determined through a combination of mass spectrometric and NMR techniques, the structure and localization of the fatty acids composing the lipid moiety. The occurrence of two distinct polymethyl-branched fatty acids presenting specific localizations is consistent with the presence of two highly related polyketide synthases (Pks5 and Pks5.1) in M. marinum and presumably involved in the synthesis of these fatty acyl chains. In addition, a bioinformatic search permitted us to identify a set of enzymes potentially involved in the biosynthesis or transfer of these lipids to the LOS trehalose unit. These include MMAR_2343, a member of the Pap (polyketide-associated protein) family, that acylates trehalose-based glycolipids in M. marinum. The participation of MMAR_2343 to LOS assembly was demonstrated using a M. marinum mutant carrying a transposon insertion in the MMAR_2343 gene. Disruption of MMAR_2343 resulted in a severe LOS breakdown, indicating that MMAR_2343, hereafter designated PapA4, fulfills the requirements for LOS acylation and assembly. PMID:21803773

The R117A variant of the Escherichia coli transacylase FabD synthesizes novel acyl-(acyl carrier proteins).

Science.gov (United States)

Marcella, Aaron M; Barb, Adam W

2017-12-01

The commercial impact of fermentation systems producing novel and biorenewable chemicals will flourish with the expansion of enzymes engineered to synthesize new molecules. Though a small degree of natural variability exists in fatty acid biosynthesis, the molecular space accessible through enzyme engineering is fundamentally limitless. Prokaryotic fatty acid biosynthesis enzymes build carbon chains on a functionalized acyl carrier protein (ACP) that provides solubility, stability, and a scaffold for interactions with the synthetic enzymes. Here, we identify the malonyl-coenzyme A (CoA)/holo-ACP transacylase (FabD) from Escherichia coli as a platform enzyme for engineering to diversify microbial fatty acid biosynthesis. The FabD R117A variant produced novel ACP-based primer and extender units for fatty acid biosynthesis. Unlike the wild-type enzyme that is highly specific for malonyl-CoA to produce malonyl-ACP, the R117A variant synthesized acetyl-ACP, succinyl-ACP, isobutyryl-ACP, 2-butenoyl-ACP, and β-hydroxybutyryl-ACP among others from holo-ACP and the corresponding acyl-CoAs with specific activities from 3.7 to 120 nmol min -1  mg -1 . FabD R117A maintained K M values for holo-ACP (~ 40 μM) and displayed small changes in K M for acetoacetyl-CoA (110 ± 30 μM) and acetyl-CoA (200 ± 70 μM) when compared to malonyl-CoA (80 ± 30 μM). FabD R117A represents a novel catalyst that synthesizes a broad range of acyl-acyl-ACPs.

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......-CoA at 0.5 μM; and isovaleryl-CoA, n-butyryl-CoA, and n-hexanoyl-CoA at 6 μM each. The acyl-CoAs produced in this study are common building blocks of secondary metabolites and will enable the engineered production of a variety of natural products in S. cerevisiae. By providing this toolbox of acyl...

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

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

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.

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.

Silica gel-Supported Palladium Catalyst for the Acyl Sonogashira Reaction

Energy Technology Data Exchange (ETDEWEB)

Hossain, Shahin; Park, Jihoon; Park, Minkyu; Jin, Myungjong [Inha Univ., Incheon (Korea, Republic of)

2013-06-15

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

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

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

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

hypothesize that tailoring the acylation may be used to optimize intestinal translocation. This work aims to characterize acylated analogues of the therapeutic peptide salmon calcitonin (sCT), which lowers blood calcium, by systematically increasing acyl chain length at two positions, in order to elucidate...... to be optimal, as elongating the chain causes greater binding to the cell membrane but similar permeability, and we speculate that increasing the chain length further may decrease the permeability. In conclusion, acylated sCT acts as its own in vitro intestinal permeation enhancer, with reversible effects...... on Caco-2 cells, indicating that acylation of sCT may represent a promising tool to increase intestinal permeability without adding oral permeation enhancers....

Identification of N-acyl-fumonisin B1 as new cytotoxic metabolites of fumonisin mycotoxins.

Science.gov (United States)

Harrer, Henning; Laviad, Elad L; Humpf, Hans Ulrich; Futerman, Anthony H

2013-03-01

Fumonisins are mycotoxins produced by Fusarium species. The predominant derivative, fumonisin B1 (FB1), occurs in food and feed and is of health concern due to its hepatotoxic and carcinogenic effects. However, the role of FB1 metabolites on the mechanism of the toxicity, the inhibition of the ceramide synthesis, is unknown. The aim of this study was to identify new fumonisin metabolites and to evaluate their cytotoxic potential. MS, molecular biology, and in vitro enzyme assays were used to investigate fumonisin metabolism in mammalian cells overexpressing human ceramide synthase (CerS) genes. N-acyl-FB1 derivatives were detected as new metabolites in cultured cells at levels of up to 10 pmol/mg of protein. The N-acylation of FB1 and hydrolyzed FB1 was analyzed in several cell lines, including cells overexpressing CerS. The acyl-chain length of the N-acyl fumonisins depends on the CerS isoform acylating them. The N-acyl fumonisins are more cytotoxic than the parent fumonisin B1. The identification of N-acyl fumonisins with various acyl chain lengths together with the observed cytotoxicity of these compounds is a new aspect of fumonisin-related toxicity. Therefore, these new metabolites might play an important role in the mode of action of fumonisins. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

THE LATEST ADVANCEMENTS IN THE ACYLATION REACTIONS VIA CROSS-DEHYDROGENATIVE COUPLING AND/OR METAL CATALYSTS

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Soykan Ağar

2017-12-01

Full Text Available There are quite many examples in the scientific literature regarding the acylation reactions, especially the metal-catalyzed acylation reactions, metal-free acylation reactions, metal-catalyzed acylation via cross-dehydrogenative coupling (CDC reactions and metal-free acylation via cross-dehydrogenative coupling (CDC reactions. In this review paper, the most important examples of these domains were brought together and their mechanisms were exhibited in a clear, chronological format. Following these, the best example study towards green chemistry with a metal-free and high-yielding route was mentioned and discussed to demonstrate what has achieved in this field regarding the new acylation reaction mechanisms using the advantages of cross-dehydrogenative coupling (CDC reactions. The most prominent studies regarding these domains have been examined thoroughly and the latest progress in this field was explained in detail.

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

Characterization of the structure and immunostimulatory activity of a vaccine adjuvant, de-O-acylated lipooligosaccharide.

Directory of Open Access Journals (Sweden)

Ji Eun Han

Full Text Available Lipopolysaccharide (LPS is a major component of the outer membrane of Gram-negative bacteria. LPS elicits strong immunopathological responses during bacterial infection, and the lipid A moiety of LPS is responsible for this immunostimulatory activity. Lipid A exerts its biological activity by sending signals via TLR4 present on immune cells, and TLR4 agonists have been a target for vaccine adjuvant. Previously, we demonstrated an adjuvant activity of deacylated lipooligosaccharide (dLOS to viral and bacterial antigens. In this study, we characterized the chemical structure of dLOS and evaluated its immunostimulatory activity on mouse and human immune cells in comparison with monophosphoryl lipid A (MPL. dLOS consists of the R3-type core, a glucosamine disaccharide with two phosphate groups, and two N-linked acyl groups [corrected], and two N-linked acyl groups. dLOS was similar to MPL in induction of cytokine production in mouse peritoneal macrophages, but was a more potent activator in human monocytes and dendritic cells (DCs. Results of an analysis of allogeneic T cell responses revealed that dLOS induces Th1, Th2, and Th17-type immune responses in a dose-dependent manner. The immunostimulatory activities of dLOS were completely abrogated in TLR4(-/- mice, which confirms its TLR4-dependency. These results suggest that in the presence of the core oligosaccharide, O-linked acyl groups of LPS are dispensable for activating the TLR4 signaling pathway. dLOS did not cause any pathological effects or death at 0.25, 0.5, or 1 mg per kg body weight in mice in the acute toxicity tests. This result suggests that dLOS has a low toxicity. dLOS should be considered for further development as a safe and effective adjuvant for human vaccines.

Activities of acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) in microsomal preparations of developing sunflower and safflower seeds.

Science.gov (United States)

Banaś, Walentyna; Sanchez Garcia, Alicia; Banaś, Antoni; Stymne, Sten

2013-06-01

The last step in triacylglycerols (TAG) biosynthesis in oil seeds, the acylation of diacylglycerols (DAG), is catalysed by two types of enzymes: the acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT). The relative contribution of these enzymes in the synthesis of TAG has not yet been defined in any plant tissue. In the presented work, microsomal preparations were obtained from sunflower and safflower seeds at different stages of development and used in DGAT and PDAT enzyme assays. The ratio between PDAT and DGAT activity differed dramatically between the two different species. DGAT activities were measured with two different acyl acceptors and assay methods using two different acyl-CoAs, and in all cases the ratio of PDAT to DGAT activity was significantly higher in safflower than sunflower. The sunflower DGAT, measured by both methods, showed significant higher activity with 18:2-CoA than with 18:1-CoA, whereas the opposite specificity was seen with the safflower enzyme. The specificities of PDAT on the other hand, were similar in both species with 18:2-phosphatidylcholine being a better acyl donor than 18:1-PC and with acyl groups at the sn-2 position utilised about fourfold the rate of the sn-1 position. No DAG:DAG transacylase activity could be detected in the microsomal preparations.

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

Science.gov (United States)

2017-01-01

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), pKa, 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 (R2 > 0.9), compounds containing halogen atoms or nitro groups gave a lower predicted ESI response. PMID:28737384

Studies to further investigate the inhibition of human liver microsomal CYP2C8 by the acyl-β-glucuronide of gemfibrozil.

Science.gov (United States)

Jenkins, S M; Zvyaga, T; Johnson, S R; Hurley, J; Wagner, A; Burrell, R; Turley, W; Leet, J E; Philip, T; Rodrigues, A D

2011-12-01

In previous studies, gemfibrozil acyl-β-glucuronide, but not gemfibrozil, was found to be a mechanism-based inhibitor of cytochrome P450 2C8. To better understand whether this inhibition is specific for gemfibrozil acyl-β-glucuronide or whether other glucuronide conjugates are potential substrates for inhibition of this enzyme, we evaluated several pharmaceutical compounds (as their acyl glucuronides) as direct-acting and metabolism-dependent inhibitors of CYP2C8 in human liver microsomes. Of 11 compounds that were evaluated as their acyl glucuronide conjugates, only gemfibrozil acyl-β-glucuronide exhibited mechanism-based inhibition, indicating that CYP2C8 mechanism-based inhibition is very specific to certain glucuronide conjugates. Structural analogs of gemfibrozil were synthesized, and their glucuronide conjugates were prepared to further examine the mechanism of inhibition. When the aromatic methyl groups on the gemfibrozil moiety were substituted with trifluoromethyls, the resulting glucuronide conjugate was a weaker inhibitor of CYP2C8 and mechanism-based inhibition was abolished. However, the glucuronide conjugates of monomethyl gemfibrozil analogs were mechanism-based inhibitors of CYP2C8, although not as potent as gemfibrozil acyl-β-glucuronide itself. The ortho-monomethyl analog was a more potent inhibitor than the meta-monomethyl analog, indicating that CYP2C8 favors the ortho position for oxidation and potential inhibition. Molecular modeling of gemfibrozil acyl-β-glucuronide in the CYP2C8 active site is consistent with the ortho-methyl position being the favored site of covalent attachment to the heme. Moreover, hydrogen bonding to four residues (Ser100, Ser103, Gln214, and Asn217) is implicated.

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.

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...

Impact of fatty acyl composition and quantity of triglycerides on bioaccessibility of dietary carotenoids.

Science.gov (United States)

Huo, Tianyao; Ferruzzi, Mario G; Schwartz, Steven J; Failla, Mark L

2007-10-31

A carotenoid-rich salad meal with varying amounts and types of triglycerides (TG) was digested using simulated gastric and small intestinal conditions. Xanthophylls (lutein and zeaxanthin) and carotenes (alpha-carotene, beta-carotene, and lycopene) in chyme and micelle fraction were quantified to determine digestive stability and efficiency of micellarization (bioaccessibility). Micellarization of lutein (+zeaxanthin) exceeded that of alpha- and beta-carotenes, which was greater than that of lycopene for all test conditions. Micellarization of carotenes, but not lutein (+zeaxanthin), was enhanced (P structured TG (c18:1 > c8:0 > c4:0). The degree of unsaturation of c18 fatty acyl chains in TG added to the salad purée did not significantly alter the efficiency of micellarization of carotenoids. Relatively low amounts of triolein and canola oil (0.5-1%) were required for maximum micellarization of carotenes, but more oil (approximately 2.5%) was required when TG with medium chain saturated fatty acyl groups (e.g., trioctanoin and coconut oil) was added to the salad. Uptake of lutein and beta-carotene by Caco-2 cells also was examined by exposing cells to micelles generated during the simulated digestion of salad purée with either triolein or trioctanoin. Cell accumulation of beta-carotene was independent of fatty acyl composition of micelles, whereas lutein uptake was slightly, but significantly, increased from samples with digested triolein compared to trioctanoin. The results show that the in vitro transfer of alpha-carotene, beta-carotene, and lycopene from chyme to mixed micelles during digestion requires minimal (0.5-1%) lipid content in the meal and is affected by the length of fatty acyl chains but not the degree of unsaturation in TG. In contrast, fatty acyl chain length has limited if any impact on carotenoid uptake by small intestinal epithelial cells. These data suggest that the amount of TG in a typical meal does not limit the bioaccessibility of

Acute aerobic exercise differentially alters acylated ghrelin and perceived fullness in normal-weight and obese individuals.

Science.gov (United States)

Heden, Timothy D; Liu, Ying; Park, Youngmin; Dellsperger, Kevin C; Kanaley, Jill A

2013-09-01

Adiposity alters acylated ghrelin concentrations, but it is unknown whether adiposity alters the effect of exercise and feeding on acylated ghrelin responses. Therefore, the purpose of this study was to determine whether adiposity [normal-weight (NW) vs. obese (Ob)] influences the effect of exercise and feeding on acylated ghrelin, hunger, and fullness. Fourteen NW and 14 Ob individuals completed two trials in a randomized counterbalanced fashion, including a prior exercise trial (EX) and a no exercise trial (NoEX). During the EX trial, the participants performed 1 h of treadmill walking (55-60% peak O2 uptake) during the evening, 12 h before a 4-h standardized mixed meal test. Frequent blood samples were taken and analyzed for acylated ghrelin, and a visual analog scale was used to assess perceived hunger and fullness. In NW individuals, EX, compared with NoEX, reduced fasting acylated ghrelin concentrations by 18% (P = 0.03), and, in response to feeding, the change in acylated ghrelin (P = 0.02) was attenuated by 39%, but perceived hunger and fullness were unaltered. In Ob individuals, despite no changes in fasting or postprandial acylated ghrelin concentrations with EX, postprandial fullness was attenuated by 46% compared with NoEX (P = 0.05). In summary, exercise performed the night before a meal suppresses acylated ghrelin concentrations in NW individuals without altering perceived hunger or fullness. In Ob individuals, despite no changes in acylated ghrelin concentrations, EX reduced the fullness response to the test meal. Acylated ghrelin and perceived fullness responses are differently altered by acute aerobic exercise in NW and Ob individuals.

Studies on acylation of lysolecithin in chicken intestine

International Nuclear Information System (INIS)

Lokesh, B.R.; Madhava Rao, A.; Murthy, S.K.

1976-01-01

The enzymatic acylation of lysolecithin to lecithin is shown to occur in the brush border-free particulate fraction of the small intestines of neonatal chicken. It requires ATP, coenzyme A and Mg 2+ or Mn 2+ for maximal activity. The system is specific for oleic acid. The fatty acid composition at the α-position of lysolecithin does not seem to influence the rate of acylation. The fatty acid incorporated into lysolecithin is shown to occupy exclusively, the β-position. [ 32 P]lecithin and [1- 14 C]oleic acid has been used as tracers in the studies. (author)

Quantum chemical study of penicillin: Reactions after acylation

Science.gov (United States)

Li, Rui; Feng, Dacheng; Zhu, Feng

The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on ?-lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated-enzyme tetrahedral intermediate can evolves with opening of ?-lactam ring as well as the thiazole ring; the thiazole ring-open products may be formed via ?-lactam ring-open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water-assisted, their energy barriers are obviously reduced.

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

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......), tetradecadienoic acid, 14:2(n-6), and hexadecadienoic acid, 16:2(n-6). Palmitoyl-CoA and behenoyl-CoA dehydrogenase in fibroblasts were deficient. Muscle VLCAD activity was very low. DNA analysis revealed compound heterozygosity for two missense mutations in the VLCAD gene. The relatively mild clinical course may...... 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....

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

Long-term program for research and development of group separation and disintegration techniques

International Nuclear Information System (INIS)

1988-01-01

In Japan, the basic guidelines state that high-level radioactive wastes released from reprocessing of spent fuel should be processed into stable solid material, followed by storage for cooling for 30-50 years and disposal in the ground at a depth of several hundreds of meters. The Long-Term Program for Research and Development of Group Separation and Disintegration Techniques is aimed at efficient disposal of high-level wastes, reutilization of useful substances contained, and improved safety. Important processes include separation of nuclides (group separation, individual nuclide separation) and conversion (disintegration) of long-lived nuclides into short-lived or non-radioactive one. These processes can reduce the volume of high-level wastes to be left for final disposal. Research and development projects have been under way to provide techniques to separate high-level waste substances into four groups (transuranic elements, strontium/cesium, technetium/platinum group elements, and others). These projects also cover recovery of useful metals and efficient utilization of separated substances. For disintegration, conceptual studies have been carried out for the application of fast neutron beams to conversion of long half-life transuranium elements into short half-life or non-radioactive elements. (N.K.)

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

Acyl Meldrum's acid derivatives: application in organic synthesis

International Nuclear Information System (INIS)

Janikowska, K; Rachoń, J; Makowiec, S

2014-01-01

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

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...

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

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

Science.gov (United States)

2015-01-01

Summary 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

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

DEFF Research Database (Denmark)

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

2000-01-01

). Both repression and activation are dependent upon the function of either of the acyl-CoA synthetases Faa1p or Faa4p. In mammals, purified hepatocyte nuclear transcription factor 4alpha (HNF-4alpha) like E. coli FadR, binds long chain acyl-CoA directly. Coexpression of HNF-4alpha and acyl-CoA synthetase...

Remote control of regioselectivity in acyl-acyl carrier protein-desaturases.

Science.gov (United States)

Guy, Jodie E; Whittle, Edward; Moche, Martin; Lengqvist, Johan; Lindqvist, Ylva; Shanklin, John

2011-10-04

Regiospecific desaturation of long-chain saturated fatty acids has been described as approaching the limits of the discriminatory power of enzymes because the substrate entirely lacks distinguishing features close to the site of dehydrogenation. To identify the elusive mechanism underlying regioselectivity, we have determined two crystal structures of the archetypal Δ9 desaturase from castor in complex with acyl carrier protein (ACP), which show the bound ACP ideally situated to position C9 and C10 of the acyl chain adjacent to the diiron active site for Δ9 desaturation. Analysis of the structures and modeling of the complex between the highly homologous ivy Δ4 desaturase and ACP, identified a residue located at the entrance to the binding cavity, Asp280 in the castor desaturase (Lys275 in the ivy desaturase), which is strictly conserved within Δ9 and Δ4 enzymes but differs between them. We hypothesized that interaction between Lys275 and the phosphate of the pantetheine, seen in the ivy model, is key to positioning C4 and C5 adjacent to the diiron center for Δ4 desaturation. Mutating castor Asp280 to Lys resulted in a major shift from Δ9 to Δ4 desaturation. Thus, interaction between desaturase side-chain 280 and phospho-serine 38 of ACP, approximately 27 Å from the site of double-bond formation, predisposes ACP binding that favors either Δ9 or Δ4 desaturation via repulsion (acidic side chain) or attraction (positively charged side chain), respectively. Understanding the mechanism underlying remote control of regioselectivity provides the foundation for reengineering desaturase enzymes to create designer chemical feedstocks that would provide alternatives to those currently obtained from petrochemicals.

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

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...

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.

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

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...

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.

Heteropoly acid encapsulated into zeolite imidazolate framework (ZIF-67) cage as an efficient heterogeneous catalyst for Friedel–Crafts acylation

Energy Technology Data Exchange (ETDEWEB)

Ammar, Muhammad; Jiang, Sai; Ji, Shengfu, E-mail: jisf@mail.buct.edu.cn

2016-01-15

A new strategy has been developed for the encapsulation of the phosphotungstic heteropoly acid (H{sub 3}PW{sub 12}O{sub 40} denoted as PTA) into zeolite imidazolate framework (ZIF-67) cage and the PTA@ZIF-67(ec) catalysts with different PTA content were prepared. The structure of the catalysts was characterized by XRD, BET, SEM, FT-IR, ICP-AES and TG. The catalytic activity and recovery properties of the catalysts for the Friedel-Crafts acylation of anisole with benzoyl chloride were evaluated. The results showed that 14.6–31.7 wt% PTA were encapsulated in the ZIF-67 cage. The PTA@ZIF-67(ec) catalysts had good catalytic activity for Friedel-Crafts acylation. The conversion of anisole can reach ~100% and the selectivity of the production can reach ~94% over 26.5 wt% PTA@ZIF-67(ec) catalyst under the reaction condition of 120 °C and 6 h. After reaction, the catalyst can be easily separated from the reaction mixture by the centrifugation. The recovered catalyst can be reused five times and the selectivity can be kept over 90%. - Graphical abstract: The PTA@ZIF-67 catalysts with different PTA content were prepared by encapsulating the PTA into ZIF-67 cage and the as-synthesized catalysts exhibited good catalytic activity for the Friedel–Craft acylation of anisole with benzoyl chloride.

Attempts to Synthesize 3-acyl-4-hydroxycoumarins from Meldrum’s acid -- and Related Chemistry

OpenAIRE

Ye, Fengbin; Tropp, Kristin; Yu, Yiting

2007-01-01

We start our synthetic work with the acylation of Meldrum’s acid to get three different 5-acyl Meldrum’s acids. These compounds are attacked by various nucleophiles containing different hetero atoms to obtain β-ketoesters, β-ketoamides and the corresponding β-keto-phosphorus compounds respectively. New β-ketoamides could be synthesized and characterized. The reaction of acylated Meldrum’s acid and diphenylphosphine did not lead to the expected β-keto-phosphide compound, but the resulting prod...

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...

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.

Enantioselective N-Heterocyclic Carbene Catalysis via the Dienyl Acyl Azolium.

Science.gov (United States)

Gillard, Rachel M; Fernando, Jared E M; Lupton, David W

2018-04-16

Herein we report the enantioselective N-heterocyclic carbene catalyzed (4+2) annulation of the dienyl acyl azolium with enolates. The reaction exploits readily accessible acyl fluorides and TMS enol ethers to give a range of highly enantio- and diastereo-enriched cyclohexenes (most >97:3 er and >20:1 dr). The reaction was found to require high nucleophilicity NHC catalysts with mechanistic studies supporting a stepwise 1,6-addition/β-lactonization. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme of human small intestine.

Science.gov (United States)

Hiramine, Yasushi; Tanabe, Toshizumi

2011-06-01

Acyl-coenzyme A:diacylglycerol acyltransferase (DGAT) enzyme plays a significant role in dietary triacylglycerol (TAG) absorption in the small intestine. However, the characteristics of human intestinal DGAT enzyme have not been examined in detail. The aim of our study was to characterize the human intestinal DGAT enzyme by examining acyl-CoA specificity, temperature dependency, and selectivity for 1,2-diacylglycerol (DAG) or 1,3-DAG. We detected DGAT activity of human intestinal microsome and found that the acyl-CoA specificity and temperature dependency of intestinal DGAT coincided with those of recombinant human DGAT1. To elucidate the selectivity of human intestinal DGAT to 1,2-DAG or 1,3-DAG, we conducted acyl-coenzyme A:monoacylglycerol acyltransferase assays using 1- or 2-monoacylglycerol (MAG) as substrates. When 2-MAG was used as acyl acceptor, both 1,2-DAG and TAG were generated; however, when 1-MAG was used, 1,3-DAG was predominantly observed and little TAG was detected. These findings suggest that human small intestinal DGAT, which is mainly encoded by DGAT1, utilizes 1,2-DAG as the substrate to form TAG. This study will contribute to understand the lipid absorption profile in the small intestine.

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

DEFF Research Database (Denmark)

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

2005-01-01

Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate...

Reaction of tantalum-alkyne complexes with isocyanates or acyl cyanides

International Nuclear Information System (INIS)

Kataoka, Yasutaka; Oguchi, Yoshiyuki; Yoshizumi, Kazuyuki; Miwatashi, Seiji; Takai, Kazuhiko; Utimoto, Kiitiro

1992-01-01

Treatment of alkynes with low-valent tantalum derived from TiCl 5 and zinc produces tantalum-alkyne complexes (not isolated), which react in situ with phenyl isocyanate (or butyl isocyanate) to give (E)-α, β-unsaturated amides stereoselectively. The tantalum-alkyne complexes also react with acyl cyanides in the presence of BF 3 ·OEt 2 to give α-cyanohydrins. In both reactions, filtration of the reaction mixture containing the tantalum-alkyne complexes before addition of isocyanates (or acyl cyanides) is indispensable to obtain good yields. (author)

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....... The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP to target sites in chromatin. In conclusion, lack of ACBP interferes with the normal metabolic adaptation to weaning and leads...

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.

Interaction of gamma-glutamyltranspeptidase with clofibryl-S-acyl-glutathione in vitro and in vivo in rat.

Science.gov (United States)

Grillo, M P; Benet, L Z

2001-08-01

Clofibric acid (CA) is metabolized to chemically reactive acylating products that can transacylate glutathione to form clofibryl-S-acyl-glutathione (CA-SG) in vitro and in vivo. We investigated the first step in the degradation of CA-SG to the mercapturic acid conjugate, clofibryl-S-acyl-N-acetylcysteine (CA-SNAC), which is catalyzed by gamma-glutamyltranspeptidase (gamma-GT). After gamma-GT mediated cleavage of glutamate from CA-SG, the product clofibryl-S-acyl-cysteinylglycine (CA-S-CG) should undergo an intramolecular rearrangement reaction [Tate, S. S. (1975) FEBS Lett. 54, 319-322] to form clofibryl-N-acyl-cysteinylglycine (CA-N-CG). We performed in vitro studies incubating CA-SG with gamma-GT to determine the products formed, and in vivo studies examining the products excreted in urine after dosing rats with CA-SG or CA. Thus, CA-SG (0.1 mM) was incubated with gamma-GT (0.1 unit/mL) in buffer (pH 7.4, 25 degrees C) and analyzed for products formed by reversed-phase HPLC and electrospray mass spectrometry (ESI/MS). Results showed that CA-SG is degraded completely after 6 h of incubation leading to the formation of two products, CA-N-CG and its disulfide, with no detection of CA-S-CG thioester. After 36 h of incubation, only the disulfide remained in the incubation. Treatment of the disulfide with dithiothreitol led to the reappearance of CA-N-CG. ESI/LC/MS analysis of urine (16 h) extracts of CA-SG-dosed rats (200 mg/kg, iv) showed that CA-SG is degraded to CA-N-CG, CA-N-acyl-cysteine (CA-N-C) and their respective S-methylated products. The mercapturic acid conjugate (CA-SNAC) was found as a minor product. Analysis of urine extracts from CA-dosed rats (200 mg/kg, ip) resulted in the detection of clofibryl-N-acyl-cysteine (CA-N-C), but no evidence for the formation of CA-SNAC was obtained. These in vitro and in vivo experiments indicate that gamma-GT mediated degradation of clofibryl-S-acyl-glutathione leads primarily to the formation and excretion of clofibryl-N-acyl

Targeted Lipidomics in Drosophila melanogaster Identifies Novel 2-Monoacylglycerols and N-acyl Amides

Science.gov (United States)

Takacs, Sara M.; Stuart, Jordyn M.; Basnet, Arjun; Raboune, Siham; Widlanski, Theodore S.; Doherty, Patrick; Bradshaw, Heather B.

2013-01-01

Lipid metabolism is critical to coordinate organ development and physiology in response to tissue-autonomous signals and environmental cues. Changes to the availability and signaling of lipid mediators can limit competitiveness, adaptation to environmental stressors, and augment pathological processes. Two classes of lipids, the N-acyl amides and the 2-acyl glycerols, have emerged as important signaling molecules in a wide range of species with important signaling properties, though most of what is known about their cellular functions is from mammalian models. Therefore, expanding available knowledge on the repertoire of these lipids in invertebrates will provide additional avenues of research aimed at elucidating biosynthetic, metabolic, and signaling properties of these molecules. Drosophila melanogaster is a commonly used organism to study intercellular communication, including the functions of bioactive lipids. However, limited information is available on the molecular identity of lipids with putative biological activities in Drosophila. Here, we used a targeted lipidomics approach to identify putative signaling lipids in third instar Drosophila larvae, possessing particularly large lipid mass in their fat body. We identified 2-linoleoyl glycerol, 2-oleoyl glycerol, and 45 N-acyl amides in larval tissues, and validated our findings by the comparative analysis of Oregon-RS, Canton-S and w1118 strains. Data here suggest that Drosophila represent another model system to use for the study of 2-acyl glycerol and N-acyl amide signaling. PMID:23874457

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.

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...

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 ...

Group separation of organohalogenated contaminants by GCxGC

Energy Technology Data Exchange (ETDEWEB)

Korytar, P.; Leonards, P.; Boer, J. de [Netherlands Institute for Fisheries Research, IJmuiden (Netherlands); Parera, J. [Barcelona Univ. (Spain); Brinkman, U. [Vrije Univ., Amsterdam (Netherlands)

2004-09-15

The congener specific analysis of organohalogenated compounds is challenging, because of a large number of possibly interfering compounds not only within the compound class but also from congeners of other compound classes. Therefore, analytical procedures usually include complicated and time-consuming multi-step sample pre-treatment and/or selective detection (e.g. HRMS, MS/MS) in the consequent gas chromatographic analysis, what makes the procedures laborious and expensive. One way how to improve the situation would be to considerably increase the separation efficiency of the gas chromatographic analysis by replacing conventional GC by so-called comprehensive two-dimensional gas chromatography (GC x GC). In GC x GC two independent separations are applied to an entire sample which effects a considerably enhanced overall resolution and also, because of the analyte refocusing during modulation, an improved analyte detectability. One further aspect which makes GC x GC especially attractive is the ordered structure of the two-dimensional chromatograms, which is observed when mixtures of related compounds, homologues or congeners are analysed. One good example are the bands of alkanes, naphthenes and aromatics present in 2D chromatogram when petrochemical samples are analysed. The ordered structure was reported also within the compound class of some organohalogenated contaminants, more precisely, of polychlorinated biphenyls and toxaphenes (ordering to number of chlorine atoms on the skeleton). However, to date, no study of separation among the different compound classes has been reported. In the present paper, this topic will be studied for the most common contaminants. While the principle aim is the group type separation, some attention will be devoted also to within the class separation (e.g., for polychlorinated diphenylethers and polychlorinated alkanes).

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...

Intergroup conflict management strategies as related to perceptions of dual identity and separate groups.

Science.gov (United States)

Bizman, Aharon; Yinon, Yoel

2004-04-01

The authors examined the relations between (a) the perceptions of dual identity and separate groups and (b) intergroup conflict management strategies, in two contexts: the conflict between the secular and religious sectors in Israel and the allocation of resources among organizational subunits. In both contexts, contention (i.e., forcing one's will on the other party) was associated with the perception of separate groups. Only in the organizational context, avoidance (i.e., doing nothing or discontinuing participation in the conflict) was associated with the perception of dual identity. Problem solving (i.e., finding a solution that is acceptable to both parties) was related to the perception of dual identity in the secular-religious context. In the organizational context, this relation appeared only under a low perception of separate groups. Yielding (i.e., satisfying the other party's needs at the expense of one's own) was related to the perception of dual identity in the organizational context. In the secular-religious context, this relation appeared only under a high perception of separate groups. The authors discussed the varying pattern of the associations between (a) the perceptions of dual identity and separate groups and (b) the conflict management strategies in the two contexts in terms of the Dual Concern Model and the perceived feasibility of the strategies.

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.

Sulfide precipitation method of separating uranium from Group II and Group III metal ions

International Nuclear Information System (INIS)

Sundar, P.S.

1977-01-01

Uranium is separated from analytical Group II and Group III metal ions in an aqueous liquor containing uranyl ions. The liquor is extracted with a non-interfering, water-immiscible, organic solvent containing a reagent which will react with the uranyl ions to form a complex soluble in the solvent. If the liquor is acidic, the solvent is washed with water. Then to the solvent is added an aqueous solution containing about 0.5 to 1.0 mole per liter of (NH 4 ) 2 CO 3 or NH 4 HCO 3 ions and sufficient sulfide ions to precipitate the metal ions as sulfides. The solvent and the aqueous solution are separated and the sulfides filtered from the aqueous solution. The ammonium-uranyl-tricarbonate in the aqueous solution can then be precipitated by increasing the concentration of (NH 4 ) 2 CO 3 or NH 4 HCO 3 ions to about 1.5 to 2.5 moles per liter. The precipitate is filtered and calcined to obtain U 3 O 8 or UO 2 . 21 claims, 1 figure

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

Plant fatty acyl reductases: enzymes generating fatty alcohols for protective layers with potential for industrial applications.

Science.gov (United States)

Rowland, Owen; Domergue, Frédéric

2012-09-01

Primary fatty alcohols are found throughout the biological world, either in free form or in a combined state. They are common components of plant surface lipids (i.e. cutin, suberin, sporopollenin, and associated waxes) and their absence can significantly perturb these essential barriers. Fatty alcohols and/or derived compounds are also likely to have direct functions in plant biotic and abiotic interactions. An evolutionarily related set of alcohol-forming fatty acyl reductases (FARs) is present in all kingdoms of life. Plant microsomal and plastid-associated FAR enzymes have been characterized, acting on acyl-coenzymeA (acyl-CoA) or acyl-acyl carrier protein (acyl-ACP) substrates, respectively. FARs have distinct substrate specificities both with regard to chain length and chain saturation. Fatty alcohols and wax esters, which are a combination of fatty alcohol and fatty acid, have a variety of commercial applications. The expression of FARs with desired specificities in transgenic microbes or oilseed crops would provide a novel means of obtaining these valuable compounds. In the present review, we report on recent progress in characterizing plant FAR enzymes and in understanding the biological roles of primary fatty alcohols, as well as describe the biotechnological production and industrial uses of fatty alcohols. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

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

2018-05-04

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.

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

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

DEFF Research Database (Denmark)

Xu, Xuebing

1997-01-01

Production of structured lipids by lipase-catalyzed interesterification attracts great interests recently. Structured lipids are defined, in this article, as triacylglycerols which contain both medium or short chain fatty acids and long chain fatty acids, each groups locating specifically in the sn......-2 position or sn-1,3 positions of glycerol backbone. These kinds of lipids are reported to be promising for both enteral and parenteral nutrition. However, acyl migration occurs in the reaction stage and downstream purification process. This side-reaction causes by-products which are harmful...

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.

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...... DPPC-DPPS lipid mixture. The extent of peptide association deduced from the heat capacity measurements suggests a strong binding and membrane insertion of the C-14 acylated peptide in accordance with the fluorescence measurements....

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...

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.

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.

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...

Density functional theory studies on the nano-scaled composites consisted of graphene and acyl hydrazone molecules

Science.gov (United States)

Ren, J. L.; Zhou, L.; Lv, Z. C.; Ding, C. H.; Wu, Y. H.; Bai, H. C.

2016-07-01

Graphene, which is the first obtained single atomic layer 2D materials, has drawn a great of concern in nano biotechnology due to the unique property. On one hand, acyl hydrazone compounds belonging to the Schif bases have aroused considerable attention in medicine, pharmacy, and analytical reagent. However, few understanding about the interaction between graphene and acyl hydrazone molecules is now available. And such investigations are much crucial for the applications of these new nano-scaled composites. The current work revealed theoretical investigations on the nano-scaled composites built by acyl hydrazone molecules loaded on the surface of graphene. The relative energy, electronic property and the interaction between the counterparts of graphene/acyl hydrazone composites are investigated based on the density functional theory calculations. According to the obtained adsorption energy, the formation of the nano-scaled composite from the isolated graphene and acyl hydrazone molecule is exothermic, and thus it is energetically favorable to form these nano composites in viewpoint of total energy change. The frontier molecular orbital for the nano composite is mainly distributed at the graphene part, leading to that the energy levels of the frontier molecular orbital of the nano composites are very close to that of isolated graphene. Moreover, the counterpart interaction for the graphene/acyl hydrazone composites is also explored based on the discussions of orbital hybridization, charge redistribution and Van der Waals interaction.

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

Group separation of coal components and new ideas of coal utilization as petroleum

Energy Technology Data Exchange (ETDEWEB)

Zhi-hong Qin; Cui-li Hou; Juan Chen; Li-ying Zhang; Jie-qiong Ma [China University of Mining & Technology, Xuzhou (China). School of Chemical Engineering and Technology

2009-09-15

Four different groups of components were separated from coal under mild conditions of extraction and stripping process. Within these groups, and with pre-separation, individual utilization of all coal components can be realized, similar to petroleum components and enhance the inherent value and utilization value of coal, as well as increase environmental benefits. The characteristics of each component were analyzed with measurements by FTIR, GC/MS, TEM and the establishment of caking properties. The results show that coal can be separated into residues, ultra-pure coal, asphaltene components and light components by adding solvents for stripping into the CS{sub 2}/NMP mixed extraction solution. Those four groups of components present great differences in the presence of carbon and hydrogen elements, in the structure of functional groups, in their macroscopic structure and micro-morphology and caking properties. Every component possesses its own inherent values and approaches. A new idea of coal processes and utilization, similar to the use of petroleum is proposed. 11 refs., 6 figs., 6 tabs.

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

Energy Technology Data Exchange (ETDEWEB)

Angsten, Gertrud [Department of Pediatric Surgery, University Children' s Hospital, S-751 85 Uppsala (Sweden)]. E-mail: gertrud.angsten@surgsci.uu.se; Valind, Sven [Uppsala University PET Centre, Uppsala University, S-751 05 Uppsala (Sweden); Department of Clinical Physiology, University Hospital, S-751 85 Uppsala (Sweden); Takalo, Reijo [Uppsala University PET Centre, Uppsala University, S-751 05 Uppsala (Sweden); Department of Clinical Physiology, University Hospital, S-751 85 Uppsala (Sweden); Neu, Henrik [Uppsala University PET Centre, Uppsala University, S-751 05 Uppsala (Sweden); Department of Organic Chemistry, Uppsala University, S-751 24 Uppsala (Sweden); Meurling, Staffan [Department of Pediatric Surgery, University Children' s Hospital, S-751 85 Uppsala (Sweden); Langstroem, Bengt [Uppsala University PET Centre, Uppsala University, S-751 05 Uppsala (Sweden); Department of Organic Chemistry, Uppsala University, S-751 24 Uppsala (Sweden)

2005-07-01

Methods: Anesthetized pigs were studied with [{sup 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 [{sup 11}C]-FAs from blood was measured together with the relative distribution of [{sup 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: [{sup 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 [{sup 11}C]-palmitate serves well to characterize, in vivo, the carnitine-dependent transfer of long-chain FAs.

A Chemical Eight Group Separation Method for Routine Use in Gamma Spectrometric Analysis

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K

1961-04-15

A method for the separation of chemical elements in 8 groups suitable for gamma spectrometric analysis has been developed. One group of elements is separated by distillation during dissolution of the sample. The other groups are obtained by means of short ion exchange columns coupled in series An anion exchange column saturated with chloride ions separates chloride complexes, peroxides and other anions from a 3-n HCl + 0.3 % H{sub 2}O{sub 2} sample solution. Some of the chloride complexes are eluted with 0.1-n HCl + 0.3 % H{sub 2}O{sub 2} and subsequently adsorbed as cations on a cation exchange column in hydrogen form. A few eluted elements which do not form cations in this case are found in the effluent. Elements passing the anion exchange column in chloride form without adsorption are separated from a H{sub 2}O solution as citrate complexes, hydroxides, cations and hexametaphosphate complexes. This is done by coupling in series two anion exchange columns subsequently in citrate and hydroxide form and followed by a cation exchanger in sodium form. A mixed bed column ends the series. The behaviour in the separation series of most elements forming gamma emitting isotopes with half lives exceeding 10 minutes on irradiation with thermal neutrons has been studied. The method has been used, routinely for one year.

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.

Radiochromatographic assay of N-acyl-phosphatidylethanolamine-specific phospholipase D activity.

Science.gov (United States)

Fezza, Filomena; Gasperi, Valeria; Mazzei, Cinzia; Maccarrone, Mauro

2005-04-01

A radiochromatographic method has been set up to assay the activity of N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), based on reversed-phase high-performance liquid chromatography (HPLC) and online scintillation counting. The anandamide (N-arachidonoylethanolamine, AEA), product released by NAPE-PLD from the N-arachidonoyl-phosphatidylethanolamine (NArPE) substrate, was separated using a C18 column eluted with methanol-water-acetic acid and was quantified with an external standard method. Baseline separation of AEA and NArPE was completed in less than 15 min, with a detection limit of 0.5 fmol AEA at a signal-to-noise ratio of 4:1. The sensitivity and accuracy of the radiochromatographic procedure allowed detection and characterization of NAPE-PLD activity in very tiny tissue samples or in samples where the enzymatic activity is very low. With this method, we could determine the kinetic constants (i.e., apparent Michaelis-Menten constant (Km) of 40.0+/-5.6 microM and maximum velocity (Vmax) of 22.2+/-3.5 pmol/min per milligram protein toward NArPE) and the distribution of NAPE-PLD activity in brain areas and peripheral tissues of mouse. In addition, we could collect unprecedented evidence that compounds widely used in studies of the endocannabinoid system (e.g., AEA and congeners, receptor a(nta)gonists and inhibitors of AEA degradation) can also affect NAPE-PLD activity.

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......, to suppress the release of hormones from isolated islets of mouse and rat pancreas....

S-acylation of SOD1, CCS, and a stable SOD1-CCS heterodimer in human spinal cords from ALS and non-ALS subjects.

Science.gov (United States)

Antinone, Sarah E; Ghadge, Ghanashyam D; Ostrow, Lyle W; Roos, Raymond P; Green, William N

2017-01-25

Previously, we found that human Cu, Zn-superoxide dismutase (SOD1) is S-acylated (palmitoylated) in vitro and in amyotrophic lateral sclerosis (ALS) mouse models, and that S-acylation increased for ALS-causing SOD1 mutants relative to wild type. Here, we use the acyl resin-assisted capture (acyl-RAC) assay to demonstrate S-acylation of SOD1 in human post-mortem spinal cord homogenates from ALS and non-ALS subjects. Acyl-RAC further revealed that endogenous copper chaperone for SOD1 (CCS) is S-acylated in both human and mouse spinal cords, and in vitro in HEK293 cells. SOD1 and CCS formed a highly stable heterodimer in human spinal cord homogenates that was resistant to dissociation by boiling, denaturants, or reducing agents and was not observed in vitro unless both SOD1 and CCS were overexpressed. Cysteine mutations that attenuate SOD1 maturation prevented the SOD1-CCS heterodimer formation. The degree of S-acylation was highest for SOD1-CCS heterodimers, intermediate for CCS monomers, and lowest for SOD1 monomers. Given that S-acylation facilitates anchoring of soluble proteins to cell membranes, our findings suggest that S-acylation and membrane localization may play an important role in CCS-mediated SOD1 maturation. Furthermore, the highly stable S-acylated SOD1-CCS heterodimer may serve as a long-lived maturation intermediate in human spinal cord.

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

DEFF Research Database (Denmark)

Mandrup, S; Hummel, R; Ravn, S

1992-01-01

Acyl-CoA-binding protein (ACBP) is a 10 kDa protein isolated from bovine liver by virtue of its ability to bind and induce the synthesis of medium-chain acyl-CoA esters. Surprisingly, it turned out to be identical to a protein named diazepam-binding Inhibitor (DBI) claimed to be an endogenous mod...... have molecularly cloned and characterized the ACBP/DBI gene family in rat. The rat ACBP/DBI gene family comprises one expressed gene and four processed pseudogenes of which one was shown to exist in two allelic forms. The expressed gene is organized into four exons and three introns...

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...

Metabolic alkene labeling and in vitro detection of histone acylation via the aqueous oxidative Heck reaction

NARCIS (Netherlands)

Ourailidou, Maria E; Dockerty, Paul; Witte, Martin; Poelarends, Gerrit J; Dekker, Frank J

2015-01-01

The detection of protein lysine acylations remains a challenge due to lack of specific antibodies for acylations with various chain lengths. This problem can be addressed by metabolic labeling techniques using carboxylates with reactive functionalities. Subsequent chemoselective reactions with a

Production of acylated homoserine lactones by different serotypes of Vibrio anguillarum both in culture and during infection of rainbow trout

DEFF Research Database (Denmark)

Buch, C.; Sigh, J.; Nielsen, J.

2003-01-01

Onehundred and forty-eight out of onehundred and fifty strains of Vibrio anguillarum isolated from vibriosis in Danish marine aquaculture produced bacterial communication signals, acylated homoserine lactones, eliciting a response in the Agrobacterium tumefaciens (pZLR4) monitoring system. One...... strain, a serotype O4, induced a strong response in the Chromobacterium violaceum (CV026) monitoring system. Profiles of AHLs determined by TLC separation revealed the presence of at least four AHLs and a compound similar to N-3-oxo-decanoyl homoserine lactone (3-oxo-C10-HSL) was present in all strains...

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

Central acylated ghrelin improves memory function and hippocampal AMPK activation and partly reverses the impairment of energy and glucose metabolism in rats infused with β-amyloid.

Science.gov (United States)

Kang, Suna; Moon, Na Rang; Kim, Da Sol; Kim, Sung Hoon; Park, Sunmin

2015-09-01

Ghrelin is a gastric hormone released during the fasting state that targets the hypothalamus where it induces hunger; however, emerging evidence suggests it may also affect memory function. We examined the effect of central acylated-ghrelin and DES-acetylated ghrelin (native ghrelin) on memory function and glucose metabolism in an experimentally induced Alzheimer's disease (AD) rat model. AD rats were divided into 3 groups and Non-AD rats were used as a normal-control group. Each rat in the AD groups had intracerebroventricular (ICV) infusion of β-amyloid (25-35; 16.8nmol/day) into the lateral ventricle for 3 days, and then the pumps were changed to infuse either acylated-ghrelin (0.2nmol/h; AD-G), DES-acylated ghrelin (0.2nmol/h; AD-DES-G), or saline (control; AD-C) for 3 weeks. The Non-AD group had ICV infusion of β-amyloid (35-25) which does not deposit in the hippocampus. During the next 3 weeks memory function, food intake, body weight gain, body fat composition, and glucose metabolism were measured. AD-C exhibited greater β-amyloid deposition compared to Non-AD-C, and AD-G suppressed the increased β-amyloid deposition and potentiated the phosphorylation AMPK. In addition, AD-G increased the phosphorylation GSK and decreased the phosphorylation of Tau in comparison to AD-C and AD-DES-G. Cognitive function, measured by passive avoidance and water maze tests, was much lower in AD-C than Non-AD-C whereas AD-G but not AD-DES-G prevented the decrease (pglucose levels during an oral glucose tolerance test (OGTT) compared to the AD-C and AD-DES-G group (pmemory function, and energy and glucose metabolisms were partially improved, possibly due to less β-amyloid accumulation. This research suggests that interventions such as intermittent fasting to facilitate sustained elevations of acyl-ghrelin should be investigated for cognitive and metabolic benefits, especially in person with early symptoms of memory impairment. Copyright © 2015 Elsevier Inc. All rights

Synthesis and Bioactivity of Pyrazole Acyl Thiourea Derivatives

Directory of Open Access Journals (Sweden)

Jian Wu

2012-05-01

Full Text Available Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, ¹H-NMR, ¹³C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests.

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

Directory of Open Access Journals (Sweden)

Serife Vatansever-Ozen

2011-06-01

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

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

International Nuclear Information System (INIS)

Wilcox, C.A.; Olson, E.N.

1987-01-01

The BC 2 Hl muscle cell line was previously reported to contain a broad array of fatty acid acylated proteins. Palmitate was shown to be attached to membrane proteins posttranslationally through thiol ester linkages, whereas myristate was attached cotranslationally, or within seconds thereafter, to soluble and membrane-bound proteins through amide linkages. The temporal and subcellular differences between palmitate and myristate acylation suggested that these two classes of acyl proteins might follow different intracellular pathways to distinct subcellular membrane systems or organelles. In this study, the authors examined the subcellular localization of the major fatty acylated proteins in BC 4 Hl cells. Palmitate-containing proteins were localized to the plasma membrane, but only a subset of myristate-containing proteins was localized to this membrane fraction. The majority of acyl proteins were nonglycosylated and resistant to digestion with extracellular proteases, suggesting that they were not exposed to the external surface of the plasma membrane. Many proteins were, however, digested during incubation of isolated membranes with proteases, which indicates that these proteins were, however, digested during incubation of isolated membranes with proteases, which indicates that these proteins face the cytoplasm. Two-dimensional gel electrophoresis of proteins labeled with [ 3 H]palmitate and [ 3 H]myristate revealed that individual proteins were modified by only one of the two fatty acids and did not undergo both N-linked myristylation and ester-linked palmitylation. Together, these results suggest that the majority of cellular acyl proteins are routed to the cytoplasmic surface of the plasma membrane, and they raise the possibility that fatty acid acylation may play a role in intracellular sorting of nontransmembranous, nonglycosylated membrane proteins

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...

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...

Abnormal relationships between the neural response to high- and low-calorie foods and endogenous acylated ghrelin in women with active and weight-recovered anorexia nervosa.

Science.gov (United States)

Holsen, Laura M; Lawson, Elizabeth A; Christensen, Kara; Klibanski, Anne; Goldstein, Jill M

2014-08-30

Evidence contributing to the understanding of neurobiological mechanisms underlying appetite dysregulation in anorexia nervosa draws heavily on separate lines of research into neuroendocrine and neural circuitry functioning. In particular, studies consistently cite elevated ghrelin and abnormal activation patterns in homeostatic (hypothalamus) and hedonic (striatum, amygdala, insula) regions governing appetite. The current preliminary study examined the interaction of these systems, based on research demonstrating associations between circulating ghrelin levels and activity in these regions in healthy individuals. In a cross-sectional design, we studied 13 women with active anorexia nervosa (AN), 9 women weight-recovered from AN (AN-WR), and 12 healthy-weight control women using a food cue functional magnetic resonance imaging paradigm, with assessment of fasting levels of acylated ghrelin. Healthy-weight control women exhibited significant positive associations between fasting acylated ghrelin and activity in the right amygdala, hippocampus, insula, and orbitofrontal cortex in response to high-calorie foods, associations which were absent in the AN and AN-WR groups. Women with AN-WR demonstrated a negative relationship between ghrelin and activity in the left hippocampus in response to high-calorie foods, while women with AN showed a positive association between ghrelin and activity in the right orbitofrontal cortex in response to low-calorie foods. Findings suggest a breakdown in the interaction between ghrelin signaling and neural activity in relation to reward responsivity in AN, a phenomenon that may be further characterized using pharmacogenetic studies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Asymmetric Chemoenzymatic Reductive Acylation of Ketones by a Combined Iron-Catalyzed Hydrogenation-Racemization and Enzymatic Resolution Cascade

KAUST Repository

El-Sepelgy, Osama; Brzozowska, Aleksandra; Rueping, Magnus

2017-01-01

. 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

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...

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...

New polymers containing BF2-benzoylacetonate groups. Synthesis, luminescence, excimer and exciplex formation

International Nuclear Information System (INIS)

Fedorenko, Elena V.; Mirochnik, Anatolii G.; Beloliptsev, Anton Yu.

2017-01-01

In the present study, a new synthetic method for the functionalization of polystyrene (PS) and (styrene-methyl methacrylate) copolymer has been developed. Using the new method, polymers containing BF 2 -benzoylacetonate groups have been obtained through double acylation by acetic anhydride with boron trifluoride. Luminescence of the produced polymers in solutions and films has been studied. Quantum yields of polymer solution luminescence are significantly higher than those of the low-molecular-weight analog – boron difluoride benzoylacetonate. For the polymer, in which styrene fragments are separated by methyl methacrylate groups, at low concentrations of the polymer in solution one observes the monomer luminescence of BF 2 -benzoylacetonate groups, while at high concentrations – the excimer luminescence. In case of PS-based polymers, in which BF 2 -benzoylacetonate groups and phenyl rings are not separated, in diluted solutions one observes the fluorescence of the intramolecular exciplexes, while at the concentration increase – the luminescence of intermolecular exciplexes. The ability of excimer formation is responsible for the increased photostability of the produced polymers. - Highlights: •Polymers containing BF 2 -benzoylacetonate groups have been synthesized. •Luminescence of the produced polymers in solutions and films has been studied. •Formation of excimers and exciplexes in solution has been revealed. •Formation of excimers in films increases their photostability.

Structural and Functional Studies of Fatty Acyl Adenylate Ligases from E. coli and L. pneumophila

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z.; Swaminathan, S.; Zhou, R.; Sauder, J. M.; Tonge, P. J.; Burley, S. K.

2011-02-18

Fatty acyl-AMP ligase (FAAL) is a new member of a family of adenylate-forming enzymes that were recently discovered in Mycobacterium tuberculosis. They are similar in sequence to fatty acyl-coenzyme A (CoA) ligases (FACLs). However, while FACLs perform a two-step catalytic reaction, AMP ligation followed by CoA ligation using ATP and CoA as cofactors, FAALs produce only the acyl adenylate and are unable to perform the second step. We report X-ray crystal structures of full-length FAAL from Escherichia coli (EcFAAL) and FAAL from Legionella pneumophila (LpFAAL) bound to acyl adenylate, determined at resolution limits of 3.0 and 1.85 {angstrom}, respectively. The structures share a larger N-terminal domain and a smaller C-terminal domain, which together resemble the previously determined structures of FAAL and FACL proteins. Our two structures occur in quite different conformations. EcFAAL adopts the adenylate-forming conformation typical of FACLs, whereas LpFAAL exhibits a unique intermediate conformation. Both EcFAAL and LpFAAL have insertion motifs that distinguish them from the FACLs. Structures of EcFAAL and LpFAAL reveal detailed interactions between this insertion motif and the interdomain hinge region and with the C-terminal domain. We suggest that the insertion motifs support sufficient interdomain motions to allow substrate binding and product release during acyl adenylate formation, but they preclude CoA binding, thereby preventing CoA ligation.

Triacylglyceride composition and fatty acyl saturation profile of a psychrophilic and psychrotolerant fungal species grown at different temperatures.

Science.gov (United States)

Pannkuk, Evan L; Blair, Hannah B; Fischer, Amy E; Gerdes, Cheyenne L; Gilmore, David F; Savary, Brett J; Risch, Thomas S

2014-01-01

Pseudogymnoascus destructans is a psychrophilic fungus that infects cutaneous tissues in cave dwelling bats, and it is the causal agent for white nose syndrome (WNS) in North American (NA) bat populations. Geomyces pannorum is a related psychrotolerant keratinolytic species that is rarely a pathogen of mammals. In this study, we grew P. destructans and G. pannorum in static liquid cultures at favourable and suboptimal temperatures to: 1) determine if triacylglyceride profiles are species-specific, and 2) determine if there are differences in fatty acyl (FA) saturation levels with respect to temperature. Total lipids isolated from both fungal spp. were separated by thin-layer chromatography and determined to be primarily sterols (∼15 %), free fatty acids (FFAs) (∼45 %), and triacylglycerides (TAGs) (∼50 %), with minor amounts of mono-/diacylglycerides and sterol esters. TAG compositions were profiled by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF). Total fatty acid methyl esters (FAMEs) and acyl lipid unsaturation levels were determined by gas chromatography-mass spectrometry (GC-MS). Pseudogymnoascus destructans produced higher proportions of unsaturated 18C fatty acids and TAGs than G. pannorum. Pseudogymnoascus destructans and G. pannorum produced up to a two-fold increase in 18:3 fatty acids at 5 °C than at higher temperatures. TAG proportion for P. destructans at upper and lower temperature growth limits was greater than 50 % of total dried mycelia mass. These results indicate fungal spp. alter acyl lipid unsaturation as a strategy to adapt to cold temperatures. Differences between their glycerolipid profiles also provide evidence for a different metabolic strategy to support psychrophilic growth, which may influence P. destructans' pathogenicity to bats. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

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

Defluoridation potential of jute fibers grafted with fatty acyl chain

Energy Technology Data Exchange (ETDEWEB)

Manna, Suvendu; Saha, Prosenjit [Materials Science Centre, IIT Kharagpur, WB 721302 (India); Roy, Debasis, E-mail: debasis@civil.iitkgp.ernet.in [Department of Civil Engineering, IIT Kharagpur, WB 721302 (India); Sen, Ramkrishna [Department of Biotechnology, IIT Kharagpur, WB 721302 (India); Adhikari, Basudam [Materials Science Centre, IIT Kharagpur, WB 721302 (India)

2015-11-30

Graphical abstract: - Highlights: • Acyl chain grafted jute has been shown to accumulate fluoride ions. • Covalent and hydrogen bonding and protonation were the contributing factors. • The process is relatively inexpensive and maintenance-free. • Acyl chain grafted jute showed higher fluoride ions accumulation than alternatives. - Abstract: 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.

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

Acyl coenzyme A thioesterase 7 regulates neuronal fatty acid metabolism to prevent neurotoxicity.

Science.gov (United States)

Ellis, Jessica M; Wong, G William; Wolfgang, Michael J

2013-05-01

Numerous neurological diseases are associated with dysregulated lipid metabolism; however, the basic metabolic control of fatty acid metabolism in neurons remains enigmatic. Here we have shown that neurons have abundant expression and activity of the long-chain cytoplasmic acyl coenzyme A (acyl-CoA) thioesterase 7 (ACOT7) to regulate lipid retention and metabolism. Unbiased and targeted metabolomic analysis of fasted mice with a conditional knockout of ACOT7 in the nervous system, Acot7(N-/-), revealed increased fatty acid flux into multiple long-chain acyl-CoA-dependent pathways. The alterations in brain fatty acid metabolism were concomitant with a loss of lean mass, hypermetabolism, hepatic steatosis, dyslipidemia, and behavioral hyperexcitability in Acot7(N-/-) mice. These failures in adaptive energy metabolism are common in neurodegenerative diseases. In agreement, Acot7(N-/-) mice exhibit neurological dysfunction and neurodegeneration. These data show that ACOT7 counterregulates fatty acid metabolism in neurons and protects against neurotoxicity.

Endotoxin Structures in the Psychrophiles Psychromonas marina and Psychrobacter cryohalolentis Contain Distinctive Acyl Features

Directory of Open Access Journals (Sweden)

Charles R. Sweet

2014-07-01

Full Text Available Lipid A is the essential component of endotoxin (Gram-negative lipopolysaccharide, a potent immunostimulatory compound. As the outer surface of the outer membrane, the details of lipid A structure are crucial not only to bacterial pathogenesis but also to membrane integrity. This work characterizes the structure of lipid A in two psychrophiles, Psychromonas marina and Psychrobacter cryohalolentis, and also two mesophiles to which they are related using MALDI-TOF MS and fatty acid methyl ester (FAME GC-MS. P. marina lipid A is strikingly similar to that of Escherichia coli in organization and total acyl size, but incorporates an unusual doubly unsaturated tetradecadienoyl acyl residue. P. cryohalolentis also shows structural organization similar to a closely related mesophile, Acinetobacter baumannii, however it has generally shorter acyl constituents and shows many acyl variants differing by single methylene (-CH2- units, a characteristic it shares with the one previously reported psychrotolerant lipid A structure. This work is the first detailed structural characterization of lipid A from an obligate psychrophile and the second from a psychrotolerant species. It reveals distinctive structural features of psychrophilic lipid A in comparison to that of related mesophiles which suggest constitutive adaptations to maintain outer membrane fluidity in cold environments.

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

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

-CoA binding protein, ACBP, has been proposed to play a pivotal role in the intracellular trafficking and utilization of long-chain fatty acyl-CoA esters. Depletion of acyl-CoA binding protein in yeast results in aberrant organelle morphology incl. fragmented vacuoles, multi-layered plasma membranes...... and accumulation of vesicles of variable sizes. In contrast to synthesis and turn-over of glycerolipids, the levels of very-long-chain fatty acids, long-chain bases and ceramide are severely affected by Acb1p depletion, suggesting that Acb1p, rather than playing a general role, serves specific roles in cellular...

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......-CoA esters between different enzymatic systems. However, little is known about the in vivo function in mammalian cells. We have generated mice with targeted disruption of ACBP (ACBP-/-). These mice are viable and fertile and develop normally. However, around weaning the ACBP-/- mice show decreased growth......) family, around the weaning period. As a result, the hepatic de novo cholesterogenesis is significantly decreased at weaning. The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP...

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.

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...

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

An insight on acyl migration in solvent-free ethanolysis of model triglycerides using Novozym 435.

Science.gov (United States)

Sánchez, Daniel Alberto; Tonetto, Gabriela Marta; Ferreira, María Luján

2016-02-20

In this work, the ethanolysis of triglycerides catalyzed by immobilized lipase was studied, focusing on the secondary reaction of acyl migration. The catalytic tests were performed in a solvent-free reaction medium using Novozym 435 as biocatalyst. The selected experimental variables were biocatalyst loading (5-20mg), reaction time (30-90min), and chain length of the fatty acids in triglycerides with and without unsaturation (short (triacetin), medium (tricaprylin) and long (tripalmitin/triolein)). The formation of 2-monoglyceride by ethanolysis of triglycerides was favored by long reaction times and large biocatalyst loading with saturated short- to medium-chain triglycerides. In the case of long-chain triglycerides, the formation of this monoglyceride was widely limited by acyl migration. In turn, acyl migration increased the yield of ethyl esters and minimized the content of monoglycerides and diglycerides. Thus, the enzymatic synthesis of biodiesel was favored by long-chain triglycerides (which favor the acyl migration), long reaction times and large biocatalyst loading. The conversion of acylglycerides made from long-chain fatty acids with unsaturation was relatively low due to limitations in their access to the active site of the lipase. Copyright © 2016 Elsevier B.V. All rights reserved.

Acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-Ones: Molecular Switches with Varying Migrants and Substituents

International Nuclear Information System (INIS)

Dubonosov, A.D.; Rybalkin, V.P.; Tsukanov, A.V.; Minkin, V.I.; Popova, L.L.; Revinsky, Y.V.; Bren, V.A.; Minkin, V.I.

2009-01-01

Synthesis and properties of photo chromic acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent.

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.

Configurational and constitutional information storage: multiple dynamics in systems based on pyridyl and acyl hydrazones.

Science.gov (United States)

Chaur, Manuel N; Collado, Daniel; Lehn, Jean-Marie

2011-01-03

The C=N group of hydrazones can undergo E/Z isomerization both photochemically and thermally, allowing the generation of a closed process that can be tuned by either of these two physical stimuli. On the other hand, hydrazine-exchange reactions enable a constitutional change in a given hydrazone. The two classes of processes: 1) configurational (physically stimulated) and 2) constitutional (chemically stimulated) give access to short-term and long-term information storage, respectively. Such transformations are reported herein for two hydrazones (bis-pyridyl hydrazone and 2-pyridinecarboxaldehyde phenylhydrazone) that undergo a closed, chemically or physically driven process, and, in addition, can be locked or unlocked at will by metal-ion coordination or removal. These features also extend to acyl hydrazones derived from 2-pyridinecarboxaldehyde. Similarly to the terpydine-like hydrazones, such acyl hydrazones can undergo both constitutional and configurational changes, as well as metal-ion coordination. All these types of hydrazones represent dynamic systems capable of acting as multiple state molecular devices, in which the presence of coordination sites furthermore allows the metal ion-controlled locking and unlocking of the interconversion of the different states. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ETFDH mutations as a major cause of riboflavin-responsive multiple acyl-CoA dehydrogenation deficiency

DEFF Research Database (Denmark)

Olsen, Rikke K J; Olpin, Simon E; Andresen, Brage S

2007-01-01

Multiple acyl-CoA dehydrogenation deficiency (MADD) is a disorder of fatty acid, amino acid and choline metabolism that can result from defects in two flavoproteins, electron transfer flavoprotein (ETF) or ETF: ubiquinone oxidoreductase (ETF:QO). Some patients respond to pharmacological doses......; several had previously suffered cyclical vomiting. Urine organic acid and plasma acyl-carnitine profiles indicated MADD. Clinical and biochemical parameters were either totally or partly corrected after riboflavin treatment. All patients had mutations in the gene for ETF:QO. In one patient, we show...... that the ETF:QO mutations are associated with a riboflavin-sensitive impairment of ETF:QO activity. This patient also had partial deficiencies of flavin-dependent acyl-CoA dehydrogenases and respiratory chain complexes, most of which were restored to control levels after riboflavin treatment. Low activities...

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...

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...

Profiling acylated homoserine lactones in Yersinia ruckeri and influence of exogenous acyl homoserine lactones and known quorum-sensing inhibitors on protease production

DEFF Research Database (Denmark)

Kastbjerg, Vicky Gaedt; Nielsen, Kristian Fog; Dalsgaard, Inger

2007-01-01

produced at least eight different acylated homoserine lactones (AHLs) with N-(3-oxooctanoyl)-l-homoserine lactone (3-oxo-C8-HSL) being the dominant molecule. Also, some uncommon AHL, N-(3-oxoheptanoyl)-l-homoserine lactone (3-oxo-C7-HSL) and N-(3-oxononanoyl)-l-homoserine lactone (3-oxo-C9-HSL), were...

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.

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...., chloride (PMN P-01-646; CAS No. 391232-99-8) is subject to reporting under this section for the significant...

Two Predicted Transmembrane Domains Exclude Very Long Chain Fatty acyl-CoAs from the Active Site of Mouse Wax Synthase.

Directory of Open Access Journals (Sweden)

Steffen Kawelke

Full Text Available Wax esters are used as coatings or storage lipids in all kingdoms of life. They are synthesized from a fatty alcohol and an acyl-CoA by wax synthases. In order to get insights into the structure-function relationships of a wax synthase from Mus musculus, a domain swap experiment between the mouse acyl-CoA:wax alcohol acyltransferase (AWAT2 and the homologous mouse acyl-CoA:diacylglycerol O-acyltransferase 2 (DGAT2 was performed. This showed that the substrate specificity of AWAT2 is partially determined by two predicted transmembrane domains near the amino terminus of AWAT2. Upon exchange of the two domains for the respective part of DGAT2, the resulting chimeric enzyme was capable of incorporating up to 20% of very long acyl chains in the wax esters upon expression in S. cerevisiae strain H1246. The amount of very long acyl chains in wax esters synthesized by wild type AWAT2 was negligible. The effect was narrowed down to a single amino acid position within one of the predicted membrane domains, the AWAT2 N36R variant. Taken together, we provide first evidence that two predicted transmembrane domains in AWAT2 are involved in determining its acyl chain length specificity.

Alterations by peroxisome proliferators of acyl composition of hepatic phosphatidylcholine in rats, mice and guinea-pigs. Role of stearoyl-CoA desaturase.

Science.gov (United States)

Kawashima, Y; Hirose, A; Kozuka, H

1986-01-01

Rats, mice and guinea-pigs were administered p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). The treatments of rats and mice with either clofibric acid or tiadenol increased markedly the activities of stearoyl-CoA desaturase, palmitoyl-CoA chain elongation, 1-acylglycerophosphate (1-acyl-GP) acyltransferase and 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, but not 2-acylglycerophosphocholine (2-acyl-GPC) acyltransferase in liver microsomes. The treatment of guinea-pigs with clofibric acid did not cause any change in the activities of these enzymes. The treatment of guinea-pigs with tiadenol caused a slight, but significant, increase in the activities of 1-acyl-GP acyltransferase and 1-acyl-GPC acyltransferase. The treatment of rats and mice with either clofibric acid or tiadenol increased markedly the proportion of 18:1 and decreased greatly the proportion of 18:0 in liver microsomal phosphatidylcholine. However, there is a considerable difference in the effects of the two peroxisome proliferators on the composition of polyunsaturated fatty acids in phosphatidylcholine between rats and mice. The treatment of guinea-pigs with either of the two peroxisome proliferators caused no change in acyl composition of phosphatidylcholine. The possible role of stearoyl-CoA desaturation in the regulation of acyl composition of phosphatidylcholine was discussed. PMID:2874791

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.

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%

Radioactivity in the pelagic fish. II. Group separation of radioactive elements in fish tissues

Energy Technology Data Exchange (ETDEWEB)

Yamada, K; Tozawa, H; Amano, K; Takase, A

1955-01-01

Analytical group separation was performed with various ashed tissues of some fishes exposed to radioactive ash. The radioactivity was particularly large with elements belonging to the 3rd group, both A and B subgroups. The 2nd group showed considerable activity in pyloric ceca and kidney of Skipjacks. The radioactivity of the 1st and 4th groups was detected in some tissues; the 5th group showed slight activity.

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.

Anti-tumor effects of novel 5-O-acyl plumbagins based on the inhibition of mammalian DNA replicative polymerase activity.

Directory of Open Access Journals (Sweden)

Moe Kawamura

Full Text Available We previously found that vitamin K3 (menadione, 2-methyl-1,4-naphthoquinone inhibits the activity of human mitochondrial DNA polymerase γ (pol γ. In this study, we focused on plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone, and chemically synthesized novel plumbagins conjugated with C2:0 to C22:6 fatty acids (5-O-acyl plumbagins. These chemically modified plumbagins enhanced mammalian pol inhibition and their cytotoxic activity. Plumbagin conjugated with chains consisting of more than C18-unsaturated fatty acids strongly inhibited the activities of calf pol α and human pol γ. Plumbagin conjugated with oleic acid (C18:1-acyl plumbagin showed the strongest suppression of human colon carcinoma (HCT116 cell proliferation among the ten synthesized 5-O-acyl plumbagins. The inhibitory activity on pol α, a DNA replicative pol, by these compounds showed high correlation with their cancer cell proliferation suppressive activity. C18:1-Acyl plumbagin selectively inhibited the activities of mammalian pol species, but did not influence the activities of other pols and DNA metabolic enzymes tested. This compound inhibited the proliferation of various human cancer cell lines, and was the cytotoxic inhibitor showing strongest inhibition towards HT-29 colon cancer cells (LD50 = 2.9 µM among the nine cell lines tested. In an in vivo anti-tumor assay conducted on nude mice bearing solid tumors of HT-29 cells, C18:1-acyl plumbagin was shown to be a promising tumor suppressor. These data indicate that novel 5-O-acyl plumbagins act as anti-cancer agents based on mammalian DNA replicative pol α inhibition. Moreover, the results suggest that acylation of plumbagin is an effective chemical modification to improve the anti-cancer activity of vitamin K3 derivatives, such as plumbagin.

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...

Clinical aspects of short-chain acyl-CoA dehydrogenase deficiency

NARCIS (Netherlands)

Maldegem, B.T.; Wanders, R.J.A.; Wijburg, F.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

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

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.

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....

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

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.

Does des-acyl ghrelin improve glycemic control in obese diabetic subjects by decreasing acylated ghrelin levels?

Science.gov (United States)

Özcan, Behiye; Neggers, Sebastian J C M M; Miller, Anne Reifel; Yang, Hsiu-Chiung; Lucaites, Virginia; Abribat, Thierry; Allas, Soraya; Huisman, Martin; Visser, Jenny A; Themmen, Axel P N; Sijbrands, Eric J G; Delhanty, Patric J D; van der Lely, Aart Jan

2014-06-01

The objective of this study was to assess the effects of a continuous overnight infusion of des-acyl ghrelin (DAG) on acylated ghrelin (AG) levels and glucose and insulin responses to a standard breakfast meal (SBM) in eight overweight patients with type 2 diabetes. Furthermore, in the same patients and two additional subjects, the effects of DAG infusion on AG concentrations and insulin sensitivity during a hyperinsulinemic-euglycemic clamp (HEC) were assessed. A double-blind, placebo-controlled cross-over study design was implemented, using overnight continuous infusions of 3 and 10  μg DAG/kg per h and placebo to study the effects on a SBM. During a HEC, we studied the insulin sensitivity. We observed that, compared with placebo, overnight DAG administration significantly decreased postprandial glucose levels, both during continuous glucose monitoring and at peak serum glucose levels. The degree of improvement in glycemia was correlated with baseline plasma AG concentrations. Concurrently, DAG infusion significantly decreased fasting and postprandial AG levels. During the HEC, 2.5  h of DAG infusion markedly decreased AG levels, and the M-index, a measure of insulin sensitivity, was significantly improved in the six subjects in whom we were able to attain steady-state euglycemia. DAG administration was not accompanied by many side effects when compared with placebo. DAG administration improves glycemic control in obese subjects with type 2 diabetes through the suppression of AG levels. DAG is a good candidate for the development of compounds in the treatment of metabolic disorders or other conditions with a disturbed AG:DAG ratio, such as type 2 diabetes mellitus or Prader-Willi syndrome. © 2014 European Society of Endocrinology.

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.

Methylobacterium extorquens AM1 produces a novel type of acyl-homoserine lactone with a double unsaturated side chain under methylotrophic growth conditions.

Science.gov (United States)

Nieto Penalver, Carlos G; Morin, Danièle; Cantet, Franck; Saurel, Olivier; Milon, Alain; Vorholt, Julia A

2006-01-23

Acyl-homoserine lactones (acyl-HSLs) have emerged as important regulatory molecules for many gram-negative bacteria. We have found that Methylobacterium extorquens AM1, a member of the pink-pigmented facultative methylotrophs commonly present on plant surfaces, produces several acyl-HSLs depending upon the carbon source. A novel HSL was discovered with a double unsaturated carbon chain (N-(tetradecenoyl)) (C14:2) and characterized by MS and proton NMR. This long-chain acyl-HSL is synthesized by MlaI that also directs synthesis of C14:1-HSL. The Alphaproteobacterium also produces N-hexanoyl-HSL (C6-HSL) and N-octanoyl-HSL (C8-HSL) via MsaI.

The presence of acylated ghrelin during in vitro maturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development.

Science.gov (United States)

Sirini, Matias A; Anchordoquy, Juan Mateo; Anchordoquy, Juan Patricio; Pascua, Ana M; Nikoloff, Noelia; Carranza, Ana; Relling, Alejandro E; Furnus, Cecilia C

2017-10-01

The aim of this study was to investigate the effects of acylated ghrelin supplementation during in vitro maturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus-oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. The in vitro effects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.

New polymers containing BF{sub 2}-benzoylacetonate groups. Synthesis, luminescence, excimer and exciplex formation

Energy Technology Data Exchange (ETDEWEB)

Fedorenko, Elena V., E-mail: gev@ich.dvo.ru [Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 159, Prosp. 100 letiya Vladivostoka, Vladivostok 690022 (Russian Federation); Mirochnik, Anatolii G.; Beloliptsev, Anton Yu. [Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 159, Prosp. 100 letiya Vladivostoka, Vladivostok 690022 (Russian Federation)

2017-05-15

In the present study, a new synthetic method for the functionalization of polystyrene (PS) and (styrene-methyl methacrylate) copolymer has been developed. Using the new method, polymers containing BF{sub 2}-benzoylacetonate groups have been obtained through double acylation by acetic anhydride with boron trifluoride. Luminescence of the produced polymers in solutions and films has been studied. Quantum yields of polymer solution luminescence are significantly higher than those of the low-molecular-weight analog – boron difluoride benzoylacetonate. For the polymer, in which styrene fragments are separated by methyl methacrylate groups, at low concentrations of the polymer in solution one observes the monomer luminescence of BF{sub 2}-benzoylacetonate groups, while at high concentrations – the excimer luminescence. In case of PS-based polymers, in which BF{sub 2}-benzoylacetonate groups and phenyl rings are not separated, in diluted solutions one observes the fluorescence of the intramolecular exciplexes, while at the concentration increase – the luminescence of intermolecular exciplexes. The ability of excimer formation is responsible for the increased photostability of the produced polymers. - Highlights: •Polymers containing BF{sub 2}-benzoylacetonate groups have been synthesized. •Luminescence of the produced polymers in solutions and films has been studied. •Formation of excimers and exciplexes in solution has been revealed. •Formation of excimers in films increases their photostability.

Acylation of aromatic alcohols and phenols over InCl3 ...

Indian Academy of Sciences (India)

Unknown

toluene sulphonic acid,5 ZnCl2,6 COCl2,7 Sc(OTf)3. 8 or Bi(OTf)3. 9] catalyst ... tion of benzene and other aromatic compounds.12,13. In this communication, we ... val of solvent from the reaction mixture by distillation. The acylated products ...

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.

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

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...

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…

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

The Fourier U(2 Group and Separation of Discrete Variables

Directory of Open Access Journals (Sweden)

Kurt Bernardo Wolf

2011-06-01

Full Text Available The linear canonical transformations of geometric optics on two-dimensional screens form the group Sp(4,R, whose maximal compact subgroup is the Fourier group U(2_F; this includes isotropic and anisotropic Fourier transforms, screen rotations and gyrations in the phase space of ray positions and optical momenta. Deforming classical optics into a Hamiltonian system whose positions and momenta range over a finite set of values, leads us to the finite oscillator model, which is ruled by the Lie algebra so(4. Two distinct subalgebra chains are used to model arrays of N^2 points placed along Cartesian or polar (radius and angle coordinates, thus realizing one case of separation in two discrete coordinates. The N^2-vectors in this space are digital (pixellated images on either of these two grids, related by a unitary transformation. Here we examine the unitary action of the analogue Fourier group on such images, whose rotations are particularly visible.

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 excretion...... 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....... 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....

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.

Structural characterization of acyl-CoA oxidases reveals a direct link between pheromone biosynthesis and metabolic state in Caenorhabditis elegans.

Science.gov (United States)

Zhang, Xinxing; Li, Kunhua; Jones, Rachel A; Bruner, Steven D; Butcher, Rebecca A

2016-09-06

Caenorhabditis elegans secretes ascarosides as pheromones to communicate with other worms and to coordinate the development and behavior of the population. Peroxisomal β-oxidation cycles shorten the side chains of ascaroside precursors to produce the short-chain ascaroside pheromones. Acyl-CoA oxidases, which catalyze the first step in these β-oxidation cycles, have different side chain-length specificities and enable C. elegans to regulate the production of specific ascaroside pheromones. Here, we determine the crystal structure of the acyl-CoA oxidase 1 (ACOX-1) homodimer and the ACOX-2 homodimer bound to its substrate. Our results provide a molecular basis for the substrate specificities of the acyl-CoA oxidases and reveal why some of these enzymes have a very broad substrate range, whereas others are quite specific. Our results also enable predictions to be made for the roles of uncharacterized acyl-CoA oxidases in C. elegans and in other nematode species. Remarkably, we show that most of the C. elegans acyl-CoA oxidases that participate in ascaroside biosynthesis contain a conserved ATP-binding pocket that lies at the dimer interface, and we identify key residues in this binding pocket. ATP binding induces a structural change that is associated with tighter binding of the FAD cofactor. Mutations that disrupt ATP binding reduce FAD binding and reduce enzyme activity. Thus, ATP may serve as a regulator of acyl-CoA oxidase activity, thereby directly linking ascaroside biosynthesis to ATP concentration and metabolic state.

DEPENDENCE BETWEEN ACYLATION DEGREE AND SPECIFIC LYSIS ACTITIVY OF THE PSEUDOMONAS AERUGINOSA М6 BACTERIOPHAGE

Directory of Open Access Journals (Sweden)

Martynov A. V.

2016-06-01

changes to the morphology or antigen structure of phage virions and does not substantially affect the lytic activity spectrum or the average yield of infectious phage corpuscles on a single sensitive bacterial cell. Considering the relative uniqueness of any biological object (including the M6 phage being studied, the authors recognize the advisability of verifying the established patterns of the effect of various acylation levels on the biological properties of other types and morphological groups of viruses. It was proven that at phage sample acylation levels of 5%, 10%, and 20%, the specific lytic activity increased by a factor of ninety, twelve, and eight respectively. The adsorption speed constant increased by a factor of nine, eight, and eight respectively. And the duration of the latent period fell by 20% in all cases with the development of a productive infection caused by the acylated samples of the phages. The use of this chemical modification method does not cause changes to the morphology or antigen structure of phage virions and does not substantially affect the average yield of infectious phage corpuscles on a sensitive bacterial cell.

Synthesis of 1-indanones through the intramolecular Friedel-Crafts acylation reaction using NbCl5 as Lewis acid

International Nuclear Information System (INIS)

Polo, Ellen Christine; Silva-Filho, Luiz Carlos da; Silva, Gil Valdo Jose da; Constantino, Mauricio Gomes

2008-01-01

The intramolecular Friedel-Crafts acylation reaction of 3-arylpropanoic acids to give 1-indanones can be effected in good yields under mild conditions (room temperature) by using niobium pentachloride. Our results indicate that NbCl 5 acts both as reagent (to transform carboxylic acids into acyl chlorides) and as catalyst in the Friedel-Crafts cyclization. (author)

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.

Studies on lactoferricin-derived Escherichia coli membrane-active peptides reveal differences in the mechanism of N-acylated versus nonacylated peptides.

Science.gov (United States)

Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

2011-06-17

To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis.

Studies on Lactoferricin-derived Escherichia coli Membrane-active Peptides Reveal Differences in the Mechanism of N-Acylated Versus Nonacylated Peptides*

Science.gov (United States)

Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E.; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

2011-01-01

To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of Gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis. PMID:21515687

Structural characterization of acyl-CoA oxidases reveals a direct link between pheromone biosynthesis and metabolic state in Caenorhabditis elegans

Science.gov (United States)

Zhang, Xinxing; Jones, Rachel A.; Bruner, Steven D.; Butcher, Rebecca A.

2016-01-01

Caenorhabditis elegans secretes ascarosides as pheromones to communicate with other worms and to coordinate the development and behavior of the population. Peroxisomal β-oxidation cycles shorten the side chains of ascaroside precursors to produce the short-chain ascaroside pheromones. Acyl-CoA oxidases, which catalyze the first step in these β-oxidation cycles, have different side chain-length specificities and enable C. elegans to regulate the production of specific ascaroside pheromones. Here, we determine the crystal structure of the acyl-CoA oxidase 1 (ACOX-1) homodimer and the ACOX-2 homodimer bound to its substrate. Our results provide a molecular basis for the substrate specificities of the acyl-CoA oxidases and reveal why some of these enzymes have a very broad substrate range, whereas others are quite specific. Our results also enable predictions to be made for the roles of uncharacterized acyl-CoA oxidases in C. elegans and in other nematode species. Remarkably, we show that most of the C. elegans acyl-CoA oxidases that participate in ascaroside biosynthesis contain a conserved ATP-binding pocket that lies at the dimer interface, and we identify key residues in this binding pocket. ATP binding induces a structural change that is associated with tighter binding of the FAD cofactor. Mutations that disrupt ATP binding reduce FAD binding and reduce enzyme activity. Thus, ATP may serve as a regulator of acyl-CoA oxidase activity, thereby directly linking ascaroside biosynthesis to ATP concentration and metabolic state. PMID:27551084

Involvement of PlsX and the acyl-phosphate dependent sn-glycerol-3-phosphate acyltransferase PlsY in the initial stage of glycerolipid synthesis in Bacillus subtilis.

Science.gov (United States)

Hara, Yoshinori; Seki, Masahide; Matsuoka, Satoshi; Hara, Hiroshi; Yamashita, Atsushi; Matsumoto, Kouji

2008-12-01

The gene responsible for the first acylation of sn-glycerol-3-phosphate (G3P) in Bacillus subtilis has not yet been determined with certainty. The product of this first acylation, lysophosphatidic acid (LPA), is subsequently acylated again to form phosphatidic acid (PA), the primary precursor to membrane glycerolipids. A novel G3P acyltransferase (GPAT), the gene product of plsY, which uses acyl-phosphate formed by the plsX gene product, has recently been found to synthesize LPA in Streptococcus pneumoniae. We found that in B. subtilis growth arrests after repression of either a plsY homologue or a plsX homologue were overcome by expression of E. coli plsB, which encodes an acyl-acylcarrier protein (acyl-ACP)-dependent GPAT, although in the case of plsX repression a high level of plsB expression was required. B. subtilis has, therefore, a capability to use the acyl-ACP dependent GPAT of PlsB. Simultaneous expression of plsY and plsX suppressed the glycerol requirement of a strict glycerol auxotrophic derivative of the E. coli plsB26 mutant, although either one alone did not. Membrane fractions from B. subtilis cells catalyzed palmitoylphosphate-dependent acylation of [14C]-labeled G3P to synthesize [14C]-labeled LPA, whereas those from DeltaplsY cells did not. The results indicate unequivocally that PlsY is an acyl-phosphate dependent GPAT. Expression of plsX corrected the glycerol auxotrophy of a DeltaygiH (the deleted allele of an E. coli homologue of plsY) derivative of BB26-36 (plsB26 plsX50), suggesting an essential role of plsX other than substrate supply for acyl-phosphate dependent LPA synthesis. Two-hybrid examinations suggested that PlsY is associated with PlsX and that each may exist in multimeric form.

The utilization of the acyl-CoA and the involvement PDAT and DGAT in the biosynthesis of erucic acid-rich triacylglycerols in Crambe seed oil.

Science.gov (United States)

Furmanek, Tomasz; Demski, Kamil; Banaś, Walentyna; Haslam, Richard; Napier, Jonathan; Stymne, Sten; Banaś, Antoni

2014-04-01

The triacylglycerol of Crambe abyssinica seeds consist of 95% very long chain (>18 carbon) fatty acids (86% erucic acid; 22:1∆13) in the sn-1 and sn-3 positions. This would suggest that C. abyssinica triacylglycerols are not formed by the action of the phospholipid:diacylglycerol acyltransferase (PDAT), but are rather the results of acyl-CoA:diacylglycerol acyltransferase (DGAT) activity. However, measurements of PDAT and DGAT activities in microsomal membranes showed that C. abyssinica has significant PDAT activity, corresponding to about 10% of the DGAT activity during periods of rapid seed oil accumulation. The specific activity of DGAT for erucoyl-CoA had doubled at 19 days after flowering compared to earlier developmental stages, and was, at that stage, the preferred acyl donor, whereas the activities for 16:0-CoA and 18:1-CoA remained constant. This indicates that an expression of an isoform of DGAT with high specificity for erucoyl-CoA is induced at the onset of rapid erucic acid and oil accumulation in the C. abyssinica seeds. Analysis of the composition of the acyl-CoA pool during different stages of seed development showed that the percentage of erucoyl groups in acyl-CoA was much higher than in complex lipids at all stages of seed development except in the desiccation phase. These results are in accordance with published results showing that the rate limiting step in erucic acid accumulation in C. abyssinica oil is the utilization of erucoyl-CoA by the acyltransferases in the glycerol-3-phosphate pathway.

IMMOBILIZATION OF TANNIN ACYL HYDROLASE FROM ASPERGILLUS NIGER

OpenAIRE

B. Lenin Kumar*, N. Lokeswari and D. Sriramireddy

2013-01-01

ABSTRACT: Tannin acyl hydrolase, commonly referred to as tannase (E.C. 3.1.1.20), an inducible extra-cellular enzyme produced by a number of animals, plants and microbes. In this investigation, tannase production under solid-state fermentation by using Aspergillus niger and the waste residue of cashew husk was used as substrate for obtaining the desired fermented product. Microbial tannase is more stable than tannase from other sources like plants or animals. Tannase from fungal sources are r...

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

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 ...

SLC1 and SLC4 encode partially redundant acyl-coenzyme A 1-acylglycerol-3-phosphate O-acyltransferases of budding yeast

DEFF Research Database (Denmark)

Benghezal, Mohammed; Roubaty, Carole; Veepuri, Vijayanath

2007-01-01

Phosphatidic acid is the intermediate, from which all glycerophospholipids are synthesized. In yeast, it is generated from lysophosphatidic acid, which is acylated by Slc1p, an sn-2-specific, acyl-coenzyme A-dependent 1-acylglycerol-3-phosphate O-acyltransferase. Deletion of SLC1 is not lethal...

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...

On the Unusual Homeoviscous Adaptation of the Membrane Fatty Acyl Components against the Thermal Stress in RhiΖobium meliloti

International Nuclear Information System (INIS)

Kang, Seb Yung; Jung, Seun Ho; Choi, Yong Hoon; Yang, Chul Hak; Kim, Hyun Won

1999-01-01

In order to maintain the optimal fluidity in membrane, microorganism genetically regulates the ratio of the unsaturated fatty acids (Ufos) to saturated ones of its biological membrane in response to external perturbing condition such as the change of temperature. The remodelling of fatty acyl chain composition is the most frequently observed response to altered growth temperature. It is reflected in the elevated proportions of unsaturated fatty acid (UFAs) at low temperature. Because cis double bonds, normally positioned at the middle of fatty acyl chains, introduce a kink of approximately 30 .deg. into acyl chain, UFAs pack less compactly and exhibit lower melting points than their saturated homologues. Thus, enrichment of membranes with UFAs offsets, to a significant degree, the increase in membrane order caused by a drop in temperature. This is so called homeoviscous adaptation of the membrane fatty acyl chains against thermal stress. Membrane maintains the optimal viscosity using homeoviscous adaptation.

Processing and fatty acid acylation of RAS1 and RAS2 proteins in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Fujiyama, A.; Tamanoi, F.

1986-01-01

The authors demonstrate the pathway for the biosynthesis of RAS1 and RAS2 gene products of Saccharomyces cerevisiae leading to their localization in membranes. The primary translation products of these genes are detected in a soluble fraction. Shortly after synthesis, these precursor molecules are converted to forms that migrate slightly faster than the precursor forms on a NaDodSO 4 /polyacrylamide gel. These processed proteins are further modified by fatty acid acylation, which is detected by [ 3 H]palmitic acid labeling. The acylated derivatives are found exclusively in cell membranes, indicating the translocation of the RAS proteins from cytosol to membranes during maturation process. The attached fatty acids can be released by mild alkaline hydrolysis, suggesting that the linkage between the fatty acid and the protein is an ester bond. The site of the modification by fatty acid is presumably localized to the COOH-terminal portion of the RAS proteins. Fraction of the membranes by sucrose gradient demonstrates that a majority of the fatty-acylated RAS proteins are localized in plasma membrane

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.

Clear correlation of genotype with disease phenotype in very-long-chain acyl-CoA dehydrogenase deficiency

DEFF Research Database (Denmark)

Andresen, B S; Olpin, S; Poorthuis, B J

1999-01-01

Very-long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the initial rate-limiting step in mitochondrial fatty acid beta-oxidation. VLCAD deficiency is clinically heterogenous, with three major phenotypes: a severe childhood form, with early onset, high mortality, and high incidence of cardiomyop......Very-long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the initial rate-limiting step in mitochondrial fatty acid beta-oxidation. VLCAD deficiency is clinically heterogenous, with three major phenotypes: a severe childhood form, with early onset, high mortality, and high incidence...... of cardiomyopathy; a milder childhood form, with later onset, usually with hypoketotic hypoglycemia as the main presenting feature, low mortality, and rare cardiomyopathy; and an adult form, with isolated skeletal muscle involvement, rhabdomyolysis, and myoglobinuria, usually triggered by exercise or fasting......-phenotype relationship is in sharp contrast to what has been observed in medium-chain acyl-CoA dehydrogenase deficiency, in which no correlation between genotype and phenotype can be established....

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.

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

International Nuclear Information System (INIS)

Minasov, George; Wang, Xiaojun; Shoichet, Brian K.

2002-01-01

Although TEM-1 β-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 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 β-lactam ring of the substrate. The hydrolytic mechanism of class A β-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.

Metabolic Regulation of Histone Acetyltransferases by Endogenous Acyl-CoA Cofactors.

Science.gov (United States)

Montgomery, David C; Sorum, Alexander W; Guasch, Laura; Nicklaus, Marc C; Meier, Jordan L

2015-08-20

The finding that chromatin modifications are sensitive to changes in cellular cofactor levels potentially links altered tumor cell metabolism and gene expression. However, the specific enzymes and metabolites that connect these two processes remain obscure. Characterizing these metabolic-epigenetic axes is critical to understanding how metabolism supports signaling in cancer, and developing therapeutic strategies to disrupt this process. Here, we describe a chemical approach to define the metabolic regulation of lysine acetyltransferase (KAT) enzymes. Using a novel chemoproteomic probe, we identify a previously unreported interaction between palmitoyl coenzyme A (palmitoyl-CoA) and KAT enzymes. Further analysis reveals that palmitoyl-CoA is a potent inhibitor of KAT activity and that fatty acyl-CoA precursors reduce cellular histone acetylation levels. These studies implicate fatty acyl-CoAs as endogenous regulators of histone acetylation, and suggest novel strategies for the investigation and metabolic modulation of epigenetic signaling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acylation Modification of Antheraea pernyi Silk Fibroin Using Succinic Anhydride and Its Effects on Enzymatic Degradation Behavior

Directory of Open Access Journals (Sweden)

Xiufang Li

2013-01-01

Full Text Available The degradation rate of tissue engineering scaffolds should match the regeneration rate of new tissues. Controlling the degradation behavior of silk fibroin is an important subject for silk-based tissue engineering scaffolds. In this study, Antheraea pernyi silk fibroin was successfully modified with succinic anhydride and then characterized by zeta potential, ninhydrin method, and FTIR. In vitro, three-dimensional scaffolds prepared with modified silk fibroin were incubated in collagenase IA solution for 18 days to evaluate the impact of acylation on the degradation behavior. The results demonstrated that the degradation rate of modified silk fibroin scaffolds was more rapid than unmodified ones. The content of the β-sheet structure in silk fibroin obviously decreased after acylation, resulting in a high degradation rate. Above all, the degradation behavior of silk fibroin scaffolds could be regulated by acylation to match the requirements of various tissues regeneration.

Molecular structure, supramolecular organization and thermotropic phase behavior of N-acylglycine alkyl esters with matched acyl and alkyl chains.

Science.gov (United States)

Reddy, S Thirupathi; Swamy, Musti J

2017-11-01

N-Acylglycines (NAGs), the endogenous single-tailed lipids present in rat brain and other mammalian tissues, play significant roles in cell physiology and exhibit interesting pharmacological properties. In the present study, a homologous series of N-acylglycine alkyl esters (NAGEs) with matched chains were synthesized and characterized. Results of differential scanning calorimetric studies revealed that all NAGEs exhibit a single sharp phase transition and that the transition enthalpy and entropy show a linear dependence on the N-acyl and ester alkyl chain length. The structure of N-myristoylglycine myristyl ester (NMGME), solved by single-crystal X-ray diffraction, showed that the molecule adopts a linear geometry and revealed that the structure of N-myristoyl glycyl moiety in NMGME is identical to that in N-myristoylglycine. The molecules are packed in layers with the polar functional groups of the ester and amide functionalities located at the center of the layer. The crystal packing is stabilized by NH⋯O hydrogen bonds between the amide CO and NH groups of adjacent molecules as well as by CH⋯O hydrogen bonds between the amide carbonyl and the methylene CH adjacent to the ester carbonyl of neighboring molecules as well as between ester carbonyl and methylene group of the glycine moiety of adjacent molecules. Powder X-ray diffraction studies showed a linear dependence of the d-spacings on the acyl chain length, suggesting that all NAGEs adopt a structure similar to the packing exhibited in the crystal lattice of NMGME. Copyright © 2017 Elsevier B.V. All rights reserved.

Kinetic studies of the acylation of pig muscle–d-glyceraldehyde 3-phosphate dehydrogenase by 1,3-diphosphoglycerate and of proton uptake and release in the overall enzyme mechanism

Science.gov (United States)

Harrigan, P. J.; Trentham, D. R.

1973-01-01

In the presence of NAD+ the acylation by 1,3-diphosphoglycerate of the four active sites of pig muscle d-glyceraldehyde 3-phosphate dehydrogenase can be monitored at 365nm by the disappearance of the absorption band present in the binary complex of NAD+ and the enzyme. A non-specific salt effect decreased the acylation rate 25-fold when the ionic strength was increased from 0.10 to 1.0. This caused acylation to be the rate-limiting process in the enzyme-catalysed reductive dephosphorylation of 1,3-diphosphoglycerate at high ionic strength at pH8. The salt effect permitted investigation of the acylation over a wide range of conditions. Variation of pH from 5.4 to 8.6 produced at most a two-fold change in the acylation rate. One proton was taken up per site acylated at pH8.0. By using a chromophoric H+ indicator the rate of proton uptake could be monitored during the acylation and was also almost invariant in the pH range 5.5–8.5. Transient kinetic studies of the overall enzyme-catalysed reaction indicated that acylation was the process involving proton uptake at pH8.0. The enzyme mechanism is discussed in the light of these results. PMID:4360248

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

DEFF Research Database (Denmark)

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

2003-01-01

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

2-ethylhydracrylic aciduria in short/branched-chain acyl-CoA dehydrogenase deficiency

DEFF Research Database (Denmark)

Korman, Stanley H; Andresen, Brage S; Zeharia, Avraham

2005-01-01

BACKGROUND: Isolated excretion of 2-methylbutyrylglycine (2-MBG) is the hallmark of short/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD), a recently identified defect in the proximal pathway of L-isoleucine oxidation. SBCADD might be underdiagnosed because detection and recognition...

Exploiting the acylating nature of the imide-Ugi intermediate: a straightforward synthesis of tetrahydro-1,4-benzodiazepin-2-ones.

Science.gov (United States)

Mossetti, Riccardo; Saggiorato, Dèsirèe; Tron, Gian Cesare

2011-12-16

We describe a simple and novel protocol for the synthesis of tetrahydro-1,4-benzodiazepin-2-ones with three points of diversity, exploiting the acylating properties of the recently rediscovered Ugi-imide. The final compounds can be easily prepared in three synthetic steps using a multicomponent reaction, a Staudinger reduction, and an acylative protocol, with good to excellent yields for each synthetic step.

Long-chain Acyl-CoA is not increased in Myotubes established from Type 2 Diabetic Subjects

DEFF Research Database (Denmark)

Just, Malene; Faergeman, Nils J; Knudsen, Jens

2006-01-01

Accumulation of intramuscular long-chain acyl-CoA esters (LCACoA) has previously in animal and human models been suggested to play an important role in lipid induced insulin resistance. The aim of this study was to examine whether myotubes established from type 2 diabetic (T2D) subjects and lean...... controls express differences in long-chain acyl-CoA esters (LCACoA) precultured under physiological conditions and during chronic exposure to palmitate (PA) and oleic acids (OA) with/without acute insulin stimulation. No significant differences were found between diabetic and control myotubes, neither...

Synthesis of novel O-acylated-D-ribono-1,5-lactones and structural assignment supported by conventional NOESY-NMR and X-ray analysis

Energy Technology Data Exchange (ETDEWEB)

Sa, Marcus M.; Silveira, Gustavo P.; Caro, Miguel S.B. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: msa@qmc.ufsc.br; Ellena, Javier [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Fisica

2008-07-01

A practical method for the structural assignment of 3,4-O-benzylidene-D-ribono-1,5-lactones and analogues using conventional NMR techniques and NOESY measurements in solution is described. 2-O-Acyl-3,4-O-benzylidene-D-ribono-1,5-lactones were prepared in good yields by acylation of Zinner's lactone with acyl chlorides under mildly basic conditions. Structural determination of 2-O-(4-nitrobenzoyl)-3,4-O-benzylidene-D-ribono-1,5-lactone was achieved by single crystal x-ray diffraction, which supports the results based on spectroscopic data. (author)

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.

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

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Butanaminium, N-(3-aminopropyl)-N...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. (a) Chemical substance and...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts (PMN P-06-263, Chemical B; CAS No...

Accumulation of medium-chain, saturated fatty acyl moieties in seed oils of transgenic Camelina sativa.

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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.

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...... 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...

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

2,4-dimethoxybenzyl: An amide protecting group for 2-acetamido glycosyl donors

DEFF Research Database (Denmark)

Kelly, N.M.; Jensen, Knud Jørgen

2001-01-01

2,4-Dimethoxybenzyl (Dmob) was used as an amide protecting group for 2-acetamido glycosyl donors. The N-Dmob group was introduced by imine formation between 2,4-dimethoxybenzaldehyde and d-glucosamine, followed by per-O-acylation, reduction to form the amine, and finally N-acetylation to give 1...

Utilization of acidic α-amino acids as acyl donors: an effective stereo-controllable synthesis of aryl-keto α-amino acids and their derivatives.

Science.gov (United States)

Wang, Lei; Murai, Yuta; Yoshida, Takuma; Okamoto, Masashi; Tachrim, Zetryana Puteri; Hashidoko, Yasuyuki; Hashimoto, Makoto

2014-05-16

Aryl-keto-containing α-amino acids are of great importance in organic chemistry and biochemistry. They are valuable intermediates for the construction of hydroxyl α-amino acids, nonproteinogenic α-amino acids, as well as other biofunctional components. Friedel-Crafts acylation is an effective method to prepare aryl-keto derivatives. In this review, we summarize the preparation of aryl-keto containing α-amino acids by Friedel-Crafts acylation using acidic α-amino acids as acyl-donors and Lewis acids or Brönsted acids as catalysts.

Synthesis of sulfadiazinyl acyl/aryl thiourea derivatives as calf intestinal alkaline phosphatase inhibitors, pharmacokinetic properties, lead optimization, Lineweaver-Burk plot evaluation and binding analysis.

Science.gov (United States)

Sajid-Ur-Rehman; Saeed, Aamer; Saddique, Gufran; Ali Channar, Pervaiz; Ali Larik, Fayaz; Abbas, Qamar; Hassan, Mubashir; Raza, Hussain; Fattah, Tanzeela Abdul; Seo, Sung-Yum

2018-06-02

To seek the new medicinal potential of sulfadiazine drug, the free amino group of sulfadiazine was exploited to obtain acyl/aryl thioureas using simple and straightforward protocol. Acyl/aryl thioureas are well recognized bioactive pharmacophore containing moieties. A new series (4a-4j) of sulfadiazine derived acyl/aryl thioureas was synthesized and characterized through spectroscopic and elemental analysis. The synthesized derivatives 4a-4j were subjected to calf intestinal alkaline phosphatase (CIAP) activity. The derivative 4a-4j showed better inhibition potential compared to standard monopotassium phosphate (MKP). The compound 4c exhibited higher potential in the series with IC 50 0.251 ± 0.012 µM (standard KH 2 PO 4 4.317 ± 0.201 µM). Lineweaver-Burk plots revealed that most potent derivative 4c inhibition CIAP via mixed type pathway. Pharmacological investigations showed that synthesized compounds 4a-4j obey Lipinsk's rule. ADMET parameters evaluation predicted that these molecule show significant lead like properties with minimum possible toxicity and can serve as templates in drug designing. The synthetic compounds show none mutagenic and irritant behavior. Molecular docking analysis showed that compound 4c interacts with Asp273, His317 and Arg166 amino acid residues. Copyright © 2018. Published by Elsevier Ltd.

Expression of Vibrio harveyi acyl-ACP synthetase allows efficient entry of exogenous fatty acids into the Escherichia coli fatty acid and lipid A synthetic pathways.

Science.gov (United States)

Jiang, Yanfang; Morgan-Kiss, Rachael M; Campbell, John W; Chan, Chi Ho; Cronan, John E

2010-02-02

Although the Escherichia coli fatty acid synthesis (FAS) pathway is the best studied type II fatty acid synthesis system, a major experimental limitation has been the inability to feed intermediates into the pathway in vivo because exogenously supplied free fatty acids are not efficiently converted to the acyl-acyl carrier protein (ACP) thioesters required by the pathway. We report that expression of Vibrio harveyi acyl-ACP synthetase (AasS), a soluble cytosolic enzyme that ligates free fatty acids to ACP to form acyl-ACPs, allows exogenous fatty acids to enter the E. coli fatty acid synthesis pathway. The free fatty acids are incorporated intact and can be elongated or directly incorporated into complex lipids by acyltransferases specific for acyl-ACPs. Moreover, expression of AasS strains and supplementation with the appropriate fatty acid restored growth to E. coli mutant strains that lack essential fatty acid synthesis enzymes. Thus, this strategy provides a new tool for circumventing the loss of enzymes essential for FAS function.

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...

Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase.

Science.gov (United States)

Miklaszewska, Magdalena; Banaś, Antoni

2016-08-01

Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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.

Antibacterial and antifungal activities of new acylated derivatives of epigallocatechin gallate

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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.

Chemical probing of the human sirtuin 5 active site reveals its substrate acyl specificity and peptide-based inhibitors.

Science.gov (United States)

Roessler, Claudia; Nowak, Theresa; Pannek, Martin; Gertz, Melanie; Nguyen, Giang T T; Scharfe, Michael; Born, Ilona; Sippl, Wolfgang; Steegborn, Clemens; Schutkowski, Mike

2014-09-26

Sirtuins are NAD(+)-dependent deacetylases acting as sensors in metabolic pathways and stress response. In mammals there are seven isoforms. The mitochondrial sirtuin 5 is a weak deacetylase but a very efficient demalonylase and desuccinylase; however, its substrate acyl specificity has not been systematically analyzed. Herein, we investigated a carbamoyl phosphate synthetase 1 derived peptide substrate and modified the lysine side chain systematically to determine the acyl specificity of Sirt5. From that point we designed six potent peptide-based inhibitors that interact with the NAD(+) binding pocket. To characterize the interaction details causing the different substrate and inhibition properties we report several X-ray crystal structures of Sirt5 complexed with these peptides. Our results reveal the Sirt5 acyl selectivity and its molecular basis and enable the design of inhibitors for Sirt5. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

N-acylated peptides derived from human lactoferricin perturb organization of cardiolipin and phosphatidylethanolamine in cell membranes and induce defects in Escherichia coli cell division.

Directory of Open Access Journals (Sweden)

Dagmar Zweytick

Full Text Available Two types of recently described antibacterial peptides derived from human lactoferricin, either nonacylated or N-acylated, were studied for their different interaction with membranes of Escherichia coli in vivo and in model systems. Electron microscopy revealed striking effects on the bacterial membrane as both peptide types induced formation of large membrane blebs. Electron and fluorescence microscopy, however demonstrated that only the N-acylated peptides partially induced the generation of oversized cells, which might reflect defects in cell-division. Further a different distribution of cardiolipin domains on the E. coli membrane was shown only in the presence of the N-acylated peptides. The lipid was distributed over the whole bacterial cell surface, whereas cardiolipin in untreated and nonacylated peptide-treated cells was mainly located at the septum and poles. Studies with bacterial membrane mimics, such as cardiolipin or phosphatidylethanolamine revealed that both types of peptides interacted with the negatively charged lipid cardiolipin. The nonacylated peptides however induced segregation of cardiolipin into peptide-enriched and peptide-poor lipid domains, while the N-acylated peptides promoted formation of many small heterogeneous domains. Only N-acylated peptides caused additional severe effects on the main phase transition of liposomes composed of pure phosphatidylethanolamine, while both peptide types inhibited the lamellar to hexagonal phase transition. Lipid mixtures of phosphatidylethanolamine and cardiolipin revealed anionic clustering by all peptide types. However additional strong perturbation of the neutral lipids was only seen with the N-acylated peptides. Nuclear magnetic resonance demonstrated different conformational arrangement of the N-acylated peptide in anionic and zwitterionic micelles revealing possible mechanistic differences in their action on different membrane lipids. We hypothesized that both peptides kill

Biocatalytic acylation of carbohydrates with fatty acids from palm fatty acid distillates.

Science.gov (United States)

Chaiyaso, Thanongsak; H-Kittikun, Aran; Zimmermann, Wolfgang

2006-05-01

Palm fatty acid distillates (PFAD) are by-products of the palm oil refining process. Their use as the source of fatty acids, mainly palmitate, for the biocatalytic synthesis of carbohydrate fatty acid esters was investigated. Esters could be prepared in high yields from unmodified acyl donors and non-activated free fatty acids obtained from PFAD with an immobilized Candida antarctica lipase preparation. Acetone was found as a compatible non-toxic solvent, which gave the highest conversion yields in a heterogeneous reaction system without the complete solubilization of the sugars. Glucose, fructose, and other acyl acceptors could be employed for an ester synthesis with PFAD. The synthesis of glucose palmitate was optimized with regard to the water activity of the reaction mixture, the reaction temperature, and the enzyme concentration. The ester was obtained with 76% yield from glucose and PFAD after reaction for 74 h with 150 U ml(-1) immobilized lipase at 40 degrees C in acetone.

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

Science.gov (United States)

An, Xiao-De; Yu, Shouyun

2015-06-05

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

Blunted suppression of acyl-ghrelin in response to fructose ingestion in obese adolescents: the role of insulin resistance.

Science.gov (United States)

Van Name, Michelle; Giannini, Cosimo; Santoro, Nicola; Jastreboff, Ania M; Kubat, Jessica; Li, Fangyong; Kursawe, Romy; Savoye, Mary; Duran, Elvira; Dziura, James; Sinha, Rajita; Sherwin, Robert S; Cline, Gary; Caprio, Sonia

2015-03-01

Fructose consumption has risen alongside obesity and diabetes. Gut hormones involved in hunger and satiety (ghrelin and PYY) may respond differently to fructose compared with glucose ingestion. This study evaluated the effects of glucose and fructose ingestion on ghrelin and PYY in lean and obese adolescents with differing insulin sensitivity. Adolescents were divided into lean (n = 14), obese insulin sensitive (n = 12) (OIS), and obese insulin resistant (n = 15) (OIR). In a double-blind, cross-over design, subjects drank 75 g of glucose or fructose in random order, serum was obtained every 10 minutes for 60 minutes. Baseline acyl-ghrelin was highest in lean and lowest in OIR (P = 0.02). After glucose ingestion, acyl-ghrelin decreased similarly in lean and OIS but was lower in OIR (vs. lean, P = 0.03). Suppression differences were more pronounced after fructose (lean vs. OIS, P = 0.008, lean vs. OIR, P < 0.001). OIS became significantly hungrier after fructose (P = 0.015). PYY was not significantly different at baseline, varied minimally after glucose, and rose after fructose. Compared with lean, OIS adolescents have impaired acyl-ghrelin responses to fructose but not glucose, whereas OIR adolescents have blunted responses to both. Diminished suppression of acyl-ghrelin in childhood obesity, particularly if accompanied by insulin resistance, may promote hunger and overeating. © 2015 The Obesity Society.

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

Synthesis of acetylene alcohols of heterocyclic type and the acyl derivatives

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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.

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.

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

Lysine sulfonamides as novel HIV-protease inhibitors: Nepsilon-acyl aromatic alpha-amino acids.

Science.gov (United States)

Stranix, Brent R; Lavallée, Jean-François; Sévigny, Guy; Yelle, Jocelyn; Perron, Valérie; LeBerre, Nicholas; Herbart, Dominik; Wu, Jinzi J

2006-07-01

A series of lysine sulfonamide analogues bearing Nepsilon-acyl aromatic amino acids were synthesized using an efficient synthetic route. Evaluation of these novel protease inhibitors revealed compounds with high potency against wild-type and multiple-protease inhibitor-resistant HIV viruses.

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.)

[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.

Formation of adenosine 5'-tetraphosphate from the acyl phosphate intermediate: a difference between the MurC and MurD synthetases of Escherichia coli.

Science.gov (United States)

Bouhss, A; Dementin, S; van Heijenoort, J; Parquet, C; Blanot, D

1999-06-18

The mechanism of the Mur synthetases of peptidoglycan biosynthesis is thought to involve in each case the successive formation of an acyl phosphate and a tetrahedral intermediate. The existence of the acyl phosphates for the MurC and MurD enzymes from Escherichia coli was firmly established by their in situ reduction by sodium borohydride followed by acid hydrolysis, yielding the corresponding amino alcohols. Furthermore, it was found that MurD, but not MurC, catalyses the synthesis of adenosine 5'-tetraphosphate from the acyl phosphate, thereby substantiating its existence and pointing out a difference between the two enzymes.

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

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...... in obesity-related disease are poorly understood. Therefore our objective was to investigate exercise-induced postprandial satiety and ghrelin responses in overweight subjects with T2DM (N = 8) and healthy controls (N = 7). Visual analog scale satiety questionnaires (assessing hunger, thirst, food that could...... 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...

Development of an activity-based probe for acyl-protein thioesterases

Science.gov (United States)

Garland, Megan; Schulze, Christopher J.; Foe, Ian T.; van der Linden, Wouter A.; Child, Matthew A.

2018-01-01

Protein palmitoylation is a dynamic post-translational modification (PTM) important for cellular functions such as protein stability, trafficking, localization, and protein-protein interactions. S-palmitoylation occurs via the addition of palmitate to cysteine residues via a thioester linkage, catalyzed by palmitoyl acyl transferases (PATs), with removal of the palmitate catalyzed by acyl protein thioesterases (APTs) and palmitoyl-protein thioesterases (PPTs). Tools that target the regulators of palmitoylation–PATs, APTs and PPTs–will improve understanding of this essential PTM. Here, we describe the synthesis and application of a cell-permeable activity-based probe (ABP) that targets APTs in intact mammalian cells and the parasite Toxoplasma gondii. Using a focused library of substituted chloroisocoumarins, we identified a probe scaffold with nanomolar affinity for human APTs (HsAPT1 and HsAPT2) and synthesized a fluorescent ABP, JCP174-BODIPY TMR (JCP174-BT). We use JCP174-BT to profile HsAPT activity in situ in mammalian cells, to detect an APT in T. gondii (TgPPT1). We show discordance between HsAPT activity levels and total protein concentration in some cell lines, indicating that total protein levels may not be representative of APT activity in complex systems, highlighting the utility of this probe. PMID:29364904

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...

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

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 Co......A, hydroxymethylglutaryl (HMG) CoA] and phosphorylated metabolites (isopentenyl pyrophosphate, dimethylallyl pyrophosphate, geranyl pyrophosphate, farnesyl pyrophosphate). In this study, we developed a method for the precise analysis of the intracellular concentration of acetoacetyl CoA, acetyl CoA and HMG CoA; and we...... used this method for quantification of these metabolites in Saccharomyces cerevisiae, both during batch growth on glucose and on galactose and in glucose-limited chemostat cultures operated at three different dilution rates. The level of the metabolites changed depending on the growth phase...

Structure, High Affinity, and Negative Cooperativity of the Escherichia coli Holo-(Acyl Carrier Protein):Holo-(Acyl Carrier Protein) Synthase Complex.

Science.gov (United States)

Marcella, Aaron M; Culbertson, Sannie J; Shogren-Knaak, Michael A; Barb, Adam W

2017-11-24

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 2.05and 4.10Å, 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 K D =62±13nM, followed by the binding of two more equivalents of holo-ACPP with K D =1.2±0.2μM. Cooperativity was not observed for apo-ACPP which bound with K D =2.4±0.1μM. Strong product binding and high levels of holo-ACPP in the cell identify a potential regulatory role of ACPS in fatty acid biosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tissue carnitine homeostasis in very-long-chain acyl-CoA dehydrogenase-deficient mice

NARCIS (Netherlands)

Spiekerkoetter, Ute; Tokunaga, Chonan; Wendel, Udo; Mayatepek, Ertan; Ijlst, Lodewijk; Vaz, Frederic M.; van Vlies, Naomi; Overmars, Henk; Duran, Marinus; Wijburg, Frits A.; Wanders, Ronald J.; Strauss, Arnold W.

2005-01-01

Deficiency of very-long-chain acyl-CoA dehydrogenase (VLCAD) is the most common long-chain fatty acid oxidation defect and presents with heterogeneous clinical manifestations. Accumulation of long-chain acylcarnitines and deficiency of free carnitine have often been proposed to play an important

New cardenolide and acylated lignan glycosides from the aerial parts of Asclepias curassavica.

Science.gov (United States)

Warashina, Tsutomu; Shikata, Kimiko; Miyase, Toshio; Fujii, Satoshi; Noro, Tadataka

2008-08-01

Three new cardenolide glycosides and six new acylated lignan glycosides were obtained along with nineteen known compounds from the aerial parts of Asclepias curassavica L. (Asclepiadaceae). The structure of each compound was determined based on interpretations of NMR and MS measurements and chemical evidence.

Effects of acylation on the functional properties and in vitro trypsin digestibility of red kidney bean (Phaseolus vulgaris L.) protein isolate.

Science.gov (United States)

Yin, Shou-Wei; Tang, Chuan-He; Wen, Qi-Biao; Yang, Xiao-Quan

2009-01-01

The effects of succinylation and acetylation on some functional properties and the in vitro trypsin digestibility of kidney bean protein isolate (KPI) were investigated. The extent of succinylation or acetylation progressively increased from 0% to 96% to 97%, as the anhydride-to-protein ratio increased from 0 to 1 g/g. Polyacrylamide gel electrophoresis (PAGE) and zeta potential analyses indicated that acylation, especially succinylation, considerably increased the net charge and hydrodynamic radius of the proteins in KPI, especially vicilin. Acylation treatment at various anhydride-to-protein ratios (0.05 to 1 g/g) remarkably improved the protein solubility (PS) and emulsifying activity index (EAI) at neutral pH, but the improvement by succinylation was much better than that by acetylation. Succinylation resulted in a marked decrease in mechanical moduli of heat-induced gels of KPI, while the mechanical moduli were, on the contrary, increased by acetylation. Additionally, in vitro trypsin digestibility was improved by the acylation in an anhydride-type and level-dependent manner. The results suggest that the functional properties of KPI could be modulated by the chemical acylation treatment, using succinic or acetic anhydride at appropriate anhydride-to-protein ratios.

Metal Chlorides Supported Solid Catalysts for F-C Acylations of Arenes

Institute of Scientific and Technical Information of China (English)

李阳; 刘云龙; 穆曼曼; 陈立功

2015-01-01

A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeCl3/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeCl3/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeCl3/SiO2 ex-hibited higher molar ratio of Lewis acid sites and Brφnsted acid sites, which might be another reason for the in-crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2%, conversion and 82.0%, selectivity were obtained. Mean-while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.

Novel Strategies for Upstream and Downstream Processing of Tannin Acyl Hydrolase

Directory of Open Access Journals (Sweden)

Luis V. Rodríguez-Durán

2011-01-01

Full Text Available Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme.

Novel strategies for upstream and downstream processing of tannin acyl hydrolase.

Science.gov (United States)

Rodríguez-Durán, Luis V; Valdivia-Urdiales, Blanca; Contreras-Esquivel, Juan C; Rodríguez-Herrera, Raúl; Aguilar, Cristóbal N

2011-01-01

Tannin acyl hydrolase also referred as tannase is an enzyme with important applications in several science and technology fields. Due to its hydrolytic and synthetic properties, tannase could be used to reduce the negative effects of tannins in beverages, food, feed, and tannery effluents, for the production of gallic acid from tannin-rich materials, the elucidation of tannin structure, and the synthesis of gallic acid esters in nonaqueous media. However, industrial applications of tannase are still very limited due to its high production cost. Thus, there is a growing interest in the production, recovery, and purification of this enzyme. Recently, there have been published a number of papers on the improvement of upstream and downstream processing of the enzyme. These papers dealt with the search for new tannase producing microorganisms, the application of novel fermentation systems, optimization of culture conditions, the production of the enzyme by recombinant microorganism, and the design of efficient protocols for tannase recovery and purification. The present work reviews the state of the art of basic and biotechnological aspects of tannin acyl hydrolase, focusing on the recent advances in the upstream and downstream processing of the enzyme.

Lipases in green chemistry: acylation and alcoholysis on steroids and nucleosides.

Science.gov (United States)

Baldessari, Alicia; Iglesias, Luis E

2012-01-01

In this article, we describe the application of lipases in acylation and alcoholysis reactions on steroids and nucleosides. In the field of steroids, a variety of acetyl and fatty acid derivatives of androstanes, pregnanes, and cholestanes have been prepared through lipase-catalyzed acylation and alcoholysis reactions taking advantage of the high regio- and stereoselectivity of these enzymes. The substrates as well as the products show a high degree of biological activity as neurosteroids, hormones, and glucocorticoids. The regioselective preparation of diacylated nucleosides by means of an enzymatic alcoholysis allowed the synthesis of nucleosides prodrugs or modified nucleosides. The quantitative full deacylation and dealkoxycarbonylation of nucleosides and steroids is a mild synthetic method for the deprotection of these labile compounds. Some of the reported steroid and nucleoside products are novel, and it is not possible to obtain them satisfactorily by following traditional synthetic procedures. The advantages presented by this methodology, such as selectivity, mild reaction conditions, and low environmental impact, make the lipases an important tool in the application of the principles of Green Chemistry, offering a convenient way to prepare derivatives of natural compounds with a great potential in the pharmaceutical industry.

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

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

Ethanol affects acylated and total ghrelin levels in peripheral blood of alcohol-dependent rats.

Science.gov (United States)

Szulc, Michal; Mikolajczak, Przemyslaw L; Geppert, Bogna; Wachowiak, Roman; Dyr, Wanda; Bobkiewicz-Kozlowska, Teresa

2013-07-01

There is a hypothesis that ghrelin could take part in the central effects of alcohol as well as function as a peripheral indicator of the changes which occur during long-term alcohol consumption. The aim of this study was to determine a correlation between alcohol concentration and acylated and total form of ghrelin after a single administration of alcohol (intraperitoneal, i.p.) (experiment 1) and prolonged ethanol consumption (experiment 2). The study was performed using Wistar alcohol preferring (PR) and non-preferring (NP) rats and rats from inbred line (Warsaw High Preferring, WHP; Warsaw Low Preferring, WLP). It was found that ghrelin in ethanol-naive WHP animals showed a significantly lower level when compared with the ethanol-naive WLP or Wistar rats. After acute ethanol administration in doses of 1.0; 2.0 and 4.0 g/kg, i.p., the simple (WHP) or inverse (WLP and Wistar) relationship between alcohol concentration and both form of ghrelin levels in plasma were found. Chronic alcohol intake in all groups of rats led to decrease of acylated ghrelin concentration. PR and WHP rats, after chronic alcohol drinking, had lower levels of both form of ghrelin in comparison with NP and WLP rats, respectively, and the observed differences in ghrelin levels were in inverse relationship with their alcohol intake. In conclusion, it is suggested that there is a strong relationship between alcohol administration or intake, ethanol concentration in blood and both active and total ghrelin level in the experimental animals, and that ghrelin plasma concentration can be a marker of alcohol drinking predisposition. © 2013 The Authors, Addiction Biology © 2013 Society for the Study of Addiction.

Highly efficient and regioselective acylation of pharmacologically interesting cordycepin catalyzed by lipase in the eco-friendly solvent 2-methyltetrahydrofuran.

Science.gov (United States)

Chen, Zhi-Gang; Zhang, Dan-Ni; Cao, Lin; Han, Yong-Bin

2013-04-01

A total of nine lipases and three proteases were tested for enzymatic regioselective acylation(s) of cordycepin with vinyl acetate in organic media. The highest conversion with better initial reaction rate was achieved with immobilized Candida antarctica lipase B (Novozym 435). An eco-friendly solvent 2-methyltetrahydrofuran (MeTHF) was thought to be the most suitable reaction medium. Novozym 435 was found to be a useful biocatalyst for the 25-g scale syntheses of cordycepin acetate (96.2% isolated yield), and the biocatalyst displayed excellent regioselectivity and high operational stability during the transformation. The 5'-substituted cordycepin derivative was the sole detectable product from each acylation reaction. Novozym 435 could be recycled for the synthesis of cordycepin derivative on a 25-g scale and 63% of its original activity was maintained after being reused for 7 batches. MeTHF could be considered as an eco-friendly solvent for the large scale use in biotransformation. Copyright © 2013 Elsevier Ltd. All rights reserved.

New acylated flavone and cyanogenic glycosides from Linum grandiflorum

DEFF Research Database (Denmark)

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

2009-01-01

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

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...

Very long-chain acyl-coenzyme A dehydrogenase deficiency

Directory of Open Access Journals (Sweden)

A. V. Degtyareva

2014-01-01

Full Text Available The paper describes a case of a baby with a severe infant form of very long-chain acyl-coenzyme A dehydrogenase deficiency, a very rare genetic disorder. The basis for the disease is a disorder of mitochondrial β-oxidation of long-chain fatty acids. Accumulation of acyl-CoA-derived fatty acids causes a toxic effect on the myocardium and cardiac conduction system, liver, skeletal muscles, and other organs. The development of hypoglycemia is typical. Treatment in the acute period involves the immediately ceased delivery of long-chain triglycerides, the provision of the body with medium-chain triglycerides, and the correction of glycemia. In our observation the baby was born at term with a satisfactory condition in a family with a poor history (the first baby had suddenly died at the age of 3,5 months. The disease manifested itself as bradyarrhythmia and cardiac arrest on day 2 of life. The clinical symptom complex also included hepatomegalia, hypoglycemic episodes, lactate acidosis, and elevated blood levels of cytolytic enzymes and creatine phosphokinase. The diagnosis was suspected on the basis of the high blood values of acylcarnitines (primarily C14:1 and verified by a molecular genetic examination. Syndrome therapy and dietotherapy resulted in the abolishment of the abnormality. At the age of 2 years of life, the infant’s physical, motor, mental, and speech development corresponded to his age although he had mild right-sided hemiparesis. Thus, timely therapy determines the favorable prognosis of the disease even in its severe infant forms. 

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.

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

A Chemical Eight Group Separation Method for Routine Use in Gamma Spectrometric Analysis. II. Detailed analytical schema

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K

1961-06-15

A detailed ion-exchange procedure for the separation of chemical elements in eight groups suitable for subsequent gamma spectrometric analysis is described. The method has been in use for gamma spectrometry of some inorganic - but mostly organic - samples for one year. The separation time for inorganic samples, is usually about 1.5 hours and for organic samples as least 2 hours. One man can separate and count three samples per day. In comparative measurements of short-lived isotopes in biological material 10-12 elements can be analysed thus making possible 30 - 35 determinations per day for one man.

Application of an Acyl-CoA Ligase from Streptomyces aizunensis for Lactam Biosynthesis

DEFF Research Database (Denmark)

Zhang, Jingwei; Barajas, Jesus F.; Burdu, Mehmet

2017-01-01

lactams under ambient conditions. In this study, we demonstrated production of these chemicals using ORF26, an acyl-CoA ligase involved in the biosynthesis of ECO-02301 in Streptomyces aizunensis. This enzyme has a broad substrate spectrum and can cyclize 4-aminobutyric acid into γ-butyrolactam, 5...

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.

Checks and balances in membrane phospholipid class and acyl chain homeostasis, the yeast perspective

NARCIS (Netherlands)

de Kroon, A.I.P.M.|info:eu-repo/dai/nl/084765283; Rijken, P.J.|info:eu-repo/dai/nl/32716297X; De Smet, C.H.|info:eu-repo/dai/nl/304824224

2013-01-01

Glycerophospholipids are the most abundant membrane lipid constituents in most eukaryotic cells. As a consequence, phospholipid class and acyl chain homeostasis are crucial for maintaining optimal physical properties of membranes that in turn are crucial for membrane function. The topic of this

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

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...

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)

Plasma acyl ghrelin and nonesterified fatty acids are the best predictors for hunger status in pregnant gilts.

Science.gov (United States)

Ren, P; Yang, X J; Kim, J S; Menon, D; Pangeni, D; Manu, H; Tekeste, A; Baidoo, S K

2017-12-01

Sows are usually restricted fed during pregnancy to maximize their reproductive efficiency, which may predispose sows to a state of hunger. However, an objective measurement of hunger status has not been established. In the present study, we examined the correlation of plasma hormones and NEFA and selected the best predictors for hunger status using pregnant gilts. Three different levels of feed intake (0.5, 1.0 and 2.0 × maintenance energy intake [0.5M, 1.0M and 2.0M, respectively]) were imposed from Day 28 to 34 of gestation to create different hunger statuses in pregnant gilts. Plasma hormones related to energy homeostasis and NEFA were analyzed to quantify their response to different levels of feed intake. A total of 18 gilts (197.53 ± 6.41 kg) were allotted to 1 of 3 dietary treatments using a completely randomized design. Results showed that BW change, ADG, and G:F from Day 28 to 34 of gestation were higher ( ghrelin concentrations showed a relatively flat pattern during the 24-h period. Plasma acyl ghrelin and NEFA concentrations and areas under the curve (AUC) were greater ( ghrelin was the best predictor for consumption time ( = 0.82), whereas the AUC of NEFA was the best predictor for BW ( = 0.55) or backfat change ( = 0.42) from Day 28 to 34 of gestation. In conclusion, our data suggested that a relative flat pattern existed in pregnant gilts in terms of the diurnal plasma profile of acyl ghrelin and that the level of feed intake of pregnant gilts was negatively correlated with plasma concentrations of acyl ghrelin and NEFA, which, in turn, were negatively associated with feed consumption time. The AUC of acyl ghrelin and NEFA seemed to be the best predictors for hunger status of pregnant gilts.

Xanthomonas campestris RpfB is a Fatty Acyl-CoA Ligase Required to Counteract the Thioesterase Activity of the RpfF Diffusible Signal Factor (DSF) Synthase

Science.gov (United States)

Bi, Hongkai; Yu, Yonghong; Dong, Huijuan; Wang, Haihong; Cronan, John E.

2014-01-01

SUMMARY In Xanthomonas campestris pv. campestris (Xcc), the proteins encoded by the rpf (regulator of pathogenicity factor) gene cluster produce and sense a fatty acid signal molecule called diffusible signaling factor (DSF, 2(Z)-11-methyldodecenoic acid). RpfB was reported to be involved in DSF processing and was predicted to encode an acyl-CoA ligase. We report that RpfB activates a wide range of fatty acids to their CoA esters in vitro. Moreover, RpfB can functionally replace the paradigm bacterial acyl-CoA ligase, Escherichia coli FadD, in the E. coli β-oxidation pathway and deletion of RpfB from the Xcc genome results in a strain unable to utilize fatty acids as carbon sources. An essential RpfB function in the pathogenicity factor pathway was demonstrated by the properties of a strain deleted for both the rpfB and rpfC genes. The ΔrpfB ΔrpfC strain grew poorly and lysed upon entering stationary phase. Deletion of rpfF, the gene encoding the DSF synthetic enzyme, restored normal growth to this strain. RpfF is a dual function enzyme that synthesizes DSF by dehydration of a 3-hydroxyacyl-acyl carrier protein (ACP) fatty acid synthetic intermediate and also cleaves the thioester bond linking DSF to ACP. However, the RpfF thioesterase activity is of broad specificity and upon elimination of its RpfC inhibitor RpfF attains maximal activity and its thioesterase activity proceeds to block membrane lipid synthesis by cleavage of acyl-ACP intermediates. This resulted in release of the nascent acyl chains to the medium as free fatty acids. This lack of acyl chains for phospholipid synthesis results in cell lysis unless RpfB is present to counteract the RpfF thioesterase activity by catalyzing uptake and activation of the free fatty acids to give acyl-CoAs that can be utilized to restore membrane lipid synthesis. Heterologous expression of a different fatty acid activating enzyme, the Vibrio harveyi acyl-ACP synthetase, replaced RpfB in counteracting the effects of

Recombinant expression, purification, and characterization of an acyl-CoA binding protein from Aspergillus oryzae.

Science.gov (United States)

Hao, Qing; Liu, Xiaoguang; Zhao, Guozhong; Jiang, Lu; Li, Ming; Zeng, Bin

2016-03-01

To characterize biochemically the lipid metabolism-regulating acyl-CoA binding protein (ACBP) from the industrially-important fungus Aspergillus oryzae. A full-length cDNA encoding a candidate ACBP from A. oryzae (AoACBP) was cloned and expressed in Escherichia coli as a maltose-binding protein (MBP) fusion protein. The MBP-AoACBP protein was purified by an amylose resin chromatography column. SDS-PAGE showed that MBP-AoACBP has an estimated molecular weight of 82 kDa. Microscale thermophoresis binding assay showed that the recombinant AoACBP displayed much greater affinity for palmitoyl-CoA (K d = 80 nM) than for myristoyl-CoA (K d = 510 nM), thus demonstrating the preference of AoACBP for long-chain acyl-CoA. The data support the identification of AoACBP as a long-chain ACBP in A. oryzae.

Organocatalyzed α-Sulfenylation of carbonyl compounds using N-formly/Acyl Sulfenmides

International Nuclear Information System (INIS)

Noh, Hyeon Wan; Lee, Chan; Jang, Hye Young

2017-01-01

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

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.

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...

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.

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...

Development of a sensitive method for a structural elucidation of acyl carnitines by means of GC-MS techniques

International Nuclear Information System (INIS)

Altmann, E.

1999-11-01

The goal of the present work was to develop a sensitive and reliable method to characterize the urinary acyl carnitines, to further establish it as routine procedure in hospitals, especially in Pedriatic Departments. The determination of the excreted acyl carnitines allows drawing conclusions on errors or deviations in the cellular metabolism. Applying the volatile lactone derivatives of the acyl carnitines various methods of GC/MS technique are compared. With the examined lactones under concern EI mass spectra furnish just a first incomplete information. Frequently the molecular peaks are not sufficiently intense. Yet by means of the retention times, the signals m/z 84, 85 and 144 as ion traces, as well as the characteristic fragmentation helpful information is provided. Concerning the +CI/NH 3 - mass spectra the protonated molecular ions (M + H) + and the usually very intense (M + NH 4 ) + - ions unambiguously render structural assignments. In the case of the - CI/NH 3 - mass spectra the (M-1) and (M-85) ions allow definitive assignments due to their lesser fragmentation tendency. Each of the analytical outcoming can be regarded as leading contribution in helpfully establishing the current method in every clinical hospital. (author)

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.

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.

Purification and characterization of an amidohydrolase for N4-long-chain fatty acyl derivatives of 1-beta-D-arabinofuranosylcytosine from mouse liver microsomes.

Science.gov (United States)

Hori, K; Tsuruo, T; Tsukagoshi, S; Sakurai, Y

1984-03-01

N4-Long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase, a metabolizing enzyme for N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with long-chain fatty acids, was purified from mouse liver microsomes. The purification was accomplished by solubilization of liver microsomes with Triton X-100, diethylaminoethyl cellulose chromatography, gel filtrations, hydroxyapatite chromatography, and concanavalin A:Sepharose chromatography. On sodium dodecyl sulfate:polyacrylamide gel electrophoresis, the purified enzyme preparation produced a single protein band with a molecular weight of 54,000. The enzyme had an optimal pH of 9.0, and the Michaelis constant for N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was 67 microM. The thiols such as dithiothreitol or 2-mercaptoethanol stabilized the enzyme and stimulated its activity. p-Chloromercuribenzoate, N-ethylmaleimide, diisopropylfluorophosphate, and phenylmethylsulfonyl fluoride strongly inhibited the reaction. Bovine serum albumin markedly stimulated the enzyme activity, whereas detergents such as Triton X-100, deoxycholate, and sodium dodecyl sulfate had little effect. The enzyme did not require monovalent or divalent cations. Among the series of N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with different chain lengths of acyl residues, the purified enzyme preferentially hydrolyzed the derivatives with long-chain fatty acids (C12 to C18), and N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was the most susceptible. The purified enzyme was inactive on various N-acylamino acids, amides, oligopeptides, proteins, N-acylsphingosines (ceramides), triglyceride, lecithin, and lysolecithin. These results suggest that N4-long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase may be a new type of linear amidase.

Transitional change in rat fetal cell proliferation in response to ghrelin and des-acyl ghrelin during the last stage of pregnancy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki; Nakahara, Keiko [Department of Veterinary Physiology, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192 (Japan); Kangawa, Kenji [Department of Biochemistry, National Cardiovascular Center Research Institute, Fujishirodai 5-7-1, Suita, Osaka 565-8565 (Japan); Murakami, Noboru, E-mail: a0d201u@cc.miyazaki-u.ac.jp [Department of Veterinary Physiology, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192 (Japan)

2010-03-12

Expression of mRNA for the ghrelin receptor, GHS-R1a, was detected in various peripheral and central tissues of fetal rats, including skin, bone, heart, liver, gut, brain and spinal cord, on embryonic day (ED)15 and ED17. However, its expression in skin, bone, heart and liver, but not in gut, brain and spinal cord, became relatively weak on ED19 and disappeared after birth (ND2). Ghrelin and des-acyl ghrelin facilitated the proliferation of cultured fetal (ED17, 19), but not neonatal (ND2), skin cells. On the other hand, with regard to cells from the spinal cord and hypothalamus, the proliferative effect of ghrelin continued after birth, whereas the effect of des-acyl ghrelin on neurogenesis in these tissues was lost at the ED19 fetal and ND2 neonatal stages. Immunohistochemistry revealed that the cells in the hypothalamus induced to proliferate by ghrelin at the ND2 stage were positive for nestin and glial fibrillary acidic protein. These results suggest that in the period immediately prior to, and after birth, rat fetal cells showing proliferation in response to ghrelin and des-acyl ghrelin are at a transitional stage characterized by alteration of the expression of GHS-R1a and an undefined des-acyl ghrelin receptor, their responsiveness varying among different tissues.

Transitional change in rat fetal cell proliferation in response to ghrelin and des-acyl ghrelin during the last stage of pregnancy

International Nuclear Information System (INIS)

Inoue, Yoshiyuki; Nakahara, Keiko; Kangawa, Kenji; Murakami, Noboru

2010-01-01

Expression of mRNA for the ghrelin receptor, GHS-R1a, was detected in various peripheral and central tissues of fetal rats, including skin, bone, heart, liver, gut, brain and spinal cord, on embryonic day (ED)15 and ED17. However, its expression in skin, bone, heart and liver, but not in gut, brain and spinal cord, became relatively weak on ED19 and disappeared after birth (ND2). Ghrelin and des-acyl ghrelin facilitated the proliferation of cultured fetal (ED17, 19), but not neonatal (ND2), skin cells. On the other hand, with regard to cells from the spinal cord and hypothalamus, the proliferative effect of ghrelin continued after birth, whereas the effect of des-acyl ghrelin on neurogenesis in these tissues was lost at the ED19 fetal and ND2 neonatal stages. Immunohistochemistry revealed that the cells in the hypothalamus induced to proliferate by ghrelin at the ND2 stage were positive for nestin and glial fibrillary acidic protein. These results suggest that in the period immediately prior to, and after birth, rat fetal cells showing proliferation in response to ghrelin and des-acyl ghrelin are at a transitional stage characterized by alteration of the expression of GHS-R1a and an undefined des-acyl ghrelin receptor, their responsiveness varying among different tissues.

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.

Quorum quenching by an N-acyl-homoserine lactone acylase from Pseudomonas aeruginosa PAO1

NARCIS (Netherlands)

Sio, CF; Otten, LG; Cool, RH; Diggle, SP; Braun, PG; Daykin, M; Camara, M; Williams, P; Quax, WJ; Bos, R

The virulence of the opportunistic human pathogen Pseudomonas aeruginosa PAO1 is controlled by an N-acyl-homoserine lactone (AHL)-dependent quorum-sensing system. During functional analysis of putative acylase genes in the P. aeruginosa PAO1 genome, the PA2385 gene was found to encode an acylase

Deuterium-labelled N-acyl-l-homoserine lactones (AHLs) - inter-kingdom signalling molecules - synthesis, structural studies, and interactions with model lipid membranes

International Nuclear Information System (INIS)

Jakubczyk, Dorota; Barth, Christoph; Anastassacos, Frances; Koelsch, Patrick; Schepers, Ute; Kubas, Adam; Fink, Karin; Brenner-Weiss, Gerald; Braese, Stefan

2012-01-01

N-Acyl-l-homoserine lactones (AHLs) are synthesized by Gram-negative bacteria. These quorum-sensing molecules play an important role in the context of bacterial infection and biofilm formation. They also allow communication between microorganisms and eukaryotic cells (inter-kingdom signalling). However, very little is known about the entire mechanism of those interactions. Precise structural studies are required to analyse the different AHL isomers as only one form is biologically most active. Theoretical studies combined with experimental infrared and Raman spectroscopic data are therefore undertaken to characterise the obtained compounds. To mimic interactions between AHL and cell membranes, we studied the insertion of AHL in supported lipid bilayers, using vibrational sum-frequency-generation spectroscopy. Deuterium-labelled AHLs were thus synthesized. Starting from readily available deuterated fatty acids, a two-step procedure towards deuterated N-acyl-l-homoserine lactones with varying chain lengths is described. This included the acylation of Meldrum's acid followed by amidation. Additionally, the detailed analytical evaluation of the products is presented herein. (orig.)

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...

Production of acyl-homoserine lactone quorum-sensing signals is widespread in gram-negative Methylobacterium.

Science.gov (United States)

Poonguzhali, Selvaraj; Madhaiyan, Munusamy; Sa, Tongmin

2007-02-01

Members of Methylobacterium, referred as pink-pigmented facultative methylotrophic bacteria, are frequently associated with terrestrial and aquatic plants, tending to form aggregates on the phyllosphere. We report here that the production of autoinducer molecules involved in the cell-to-cell signaling process, which is known as quorum sensing, is common among Methylobacterium species. Several strains of Methylobacterium were tested for their ability to produce N-acyl-homoserine lactone (AHL) signal molecules using different indicators. Most strains of Methylobacterium tested could elicit a positive response in Agrobacterium tumefaciens harboring lacZ fused to a gene that is regulated by autoinduction. The synthesis of these compounds was cell-density dependent, and the maximal activity was reached during the late exponential to stationary phases. The bacterial extracts were separated by thin-layer chromatography and bioassayed with A. tumefaciens NT1 (traR, tra::lacZ749). They revealed the production of various patterns of the signal molecules, which are strain dependent. At least two signal molecules could be detected in most of the strains tested, and comparison of their relative mobilities suggested that they are homologs of N-octanoyl-DL-homoserine lactone (C8-HSL) and N-decanoyl-DL-homoserine lactone (C10-HSL).

Global and Phylogenetic Distribution of Quorum Sensing Signals, Acyl Homoserine Lactones, in the Family of Vibrionaceae

DEFF Research Database (Denmark)

Rasmussen, Bastian Barker; Nielsen, Kristian Fog; Machado, Henrique

2014-01-01

Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae in the en......Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae...... violaceum reporter strains. Ethyl acetate extracts of the cultures were analysed by ultra-high performance liquid chromatography-high resolution mass spectrometry (MS) with automated tandem MS confirmation for AHLs. N-(3-hydroxy-hexanoyl) (OH-C6) and N-(3-hydroxy-decanoyl) (OH-C10) homoserine lactones were...

Isolation of diacyl glycerol acyl transferase (DGAT) inhibitors from Pachydictyon coriaceum.

Science.gov (United States)

Choi, Byoung Wook; Lee, Hyun Sun; Lee, Kyung Bok; Lee, Bong Ho

2011-07-01

The pharmacological inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) has emerged as a target for the treatment of obesity and type 2 diabetes. Chromatographic analysis of the brown alga, Pachydictyon coriaceum, led to the isolation of diterpene dictyol E and hydroxyisocrenulatin. Pharmacological assay of these compounds demonstrated DGAT inhibitory activity with IC₅₀ values of 46.0 μM and 23.3 μM, respectively. Copyright © 2011 John Wiley & Sons, Ltd.

Enoyl-Acyl Carrier Protein Reductase I (FabI) Is Essential for the Intracellular Growth of Listeria monocytogenes

Science.gov (United States)

Ericson, Megan E.; Frank, Matthew W.

2016-01-01

Enoyl-acyl carrier protein reductase catalyzes the last step in each elongation cycle of type II bacterial fatty acid synthesis and is a key regulatory protein in bacterial fatty acid synthesis. Genes of the facultative intracellular pathogen Listeria monocytogenes encode two functional enoyl-acyl carrier protein isoforms based on their ability to complement the temperature-sensitive growth phenotype of Escherichia coli strain JP1111 [fabI(Ts)]. The FabI isoform was inactivated by the FabI selective inhibitor AFN-1252, but the FabK isoform was not affected by the drug, as expected. Inhibition of FabI by AFN-1252 decreased endogenous fatty acid synthesis by 80% and lowered the growth rate of L. monocytogenes in laboratory medium. Robust exogenous fatty acid incorporation was not detected in L. monocytogenes unless the pathway was partially inactivated by AFN-1252 treatment. However, supplementation with exogenous fatty acids did not restore normal growth in the presence of AFN-1252. FabI inactivation prevented the intracellular growth of L. monocytogenes, showing that neither FabK nor the incorporation of host cellular fatty acids was sufficient to support the intracellular growth of L. monocytogenes. Our results show that FabI is the primary enoyl-acyl carrier protein reductase of type II bacterial fatty acid synthesis and is essential for the intracellular growth of L. monocytogenes. PMID:27736774

Lipoproteins of slow-growing Mycobacteria carry three fatty acids and are N-acylated by apolipoprotein N-acyltransferase BCG_2070c.

Science.gov (United States)

Brülle, Juliane K; Tschumi, Andreas; Sander, Peter

2013-10-05

Lipoproteins are virulence factors of Mycobacterium tuberculosis. Bacterial lipoproteins are modified by the consecutive action of preprolipoprotein diacylglyceryl transferase (Lgt), prolipoprotein signal peptidase (LspA) and apolipoprotein N- acyltransferase (Lnt) leading to the formation of mature triacylated lipoproteins. Lnt homologues are found in Gram-negative and high GC-rich Gram-positive, but not in low GC-rich Gram-positive bacteria, although N-acylation is observed. In fast-growing Mycobacterium smegmatis, the molecular structure of the lipid modification of lipoproteins was resolved recently as a diacylglyceryl residue carrying ester-bound palmitic acid and ester-bound tuberculostearic acid and an additional amide-bound palmitic acid. We exploit the vaccine strain Mycobacterium bovis BCG as model organism to investigate lipoprotein modifications in slow-growing mycobacteria. Using Escherichia coli Lnt as a query in BLASTp search, we identified BCG_2070c and BCG_2279c as putative lnt genes in M. bovis BCG. Lipoproteins LprF, LpqH, LpqL and LppX were expressed in M. bovis BCG and BCG_2070c lnt knock-out mutant and lipid modifications were analyzed at molecular level by matrix-assisted laser desorption ionization time-of-flight/time-of-flight analysis. Lipoprotein N-acylation was observed in wildtype but not in BCG_2070c mutants. Lipoprotein N- acylation with palmitoyl and tuberculostearyl residues was observed. Lipoproteins are triacylated in slow-growing mycobacteria. BCG_2070c encodes a functional Lnt in M. bovis BCG. We identified mycobacteria-specific tuberculostearic acid as further substrate for N-acylation in slow-growing mycobacteria.

Synthesis and biological evaluation of triazole-containing N-acyl homoserine lactones as quorum sensing modulators

DEFF Research Database (Denmark)

Stacy, Danielle M.; Le Quement, Sebastian T.; Hansen, Casper L.

2013-01-01

triazole-containing analogs of natural N-acyl l-homoserine lactone (AHL) signals as non-native QS agonists and antagonists in Gram-negative bacteria. We synthesized 72 triazole derivatives of five broad structure types in high yields and purities using efficient Cu(i)-catalyzed azide–alkyne couplings...

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

DNA-based prenatal diagnosis for severe and variant forms of multiple acyl-CoA dehydrogenation deficiency

DEFF Research Database (Denmark)

Olsen, Rikke K J; Andresen, Brage S; Christensen, Ernst

2005-01-01

OBJECTIVES: Multiple acyl-CoA dehydrogenation deficiency (MADD) is a clinically heterogeneous disorder of mitochondrial fatty acid, amino acid, and choline oxidation due to mutations in the genes encoding electron transfer flavoprotein (ETF) or ETF ubiquinone oxidoreductase (ETFQO). So far...

Biosynthesis of triacylglycerols containing very long chain monounsaturated acyl moieties in developing seeds

International Nuclear Information System (INIS)

Fehling, E.; Murphy, D.J.; Mukherjee, K.D.

1990-01-01

Particulate (15,000g) fractions from developing seeds of honesty (Lunaria annua L.) and mustard (Sinapis alba L.) synthesize radioactive very long chain monounsaturated fatty acids (gadoleic, erucic, and nervonic) from [1- 14 C]oleoyl-CoA and malonyl-CoA or from oleoyl-CoA and [2- 14 C]malonyl-CoA. The very long chain monounsaturated fatty acids are rapidly channeled to triacylglycerols and other acyl lipids without intermediate accumulation of their CoA thioesters. When [1- 14 C]oleoyl-CoA is used as the radioactive substrate, phosphatidylcholines and other phospholipids are most extensively radiolabeled by oleoyl moieties rather than by very long chain monounsaturated acyl moieties. When [2- 14 C]malonyl-CoA is used as the radioactive substrate, no radioactive oleic acid is formed and the newly synthesized very long chain monounsaturated fatty acids are extensively incorporated into phosphatidylcholines and other phospholipids as well as triacylglycerols. The pattern of labeling of the key intermediates of the Kennedy pathway, e.g. lysophosphatidic acids, phosphatidic acids, and diacylglycerols by the newly synthesized very long chain monounsaturated fatty acids is consistent with the operation of this pathway in the biosynthesis of triacylglycerols

Untargeted metabolomics reveals specific withanolides and fatty acyl glycoside as tentative metabolites to differentiate organic and conventional Physalis peruviana fruits.

Science.gov (United States)

Llano, Sandra M; Muñoz-Jiménez, Ana M; Jiménez-Cartagena, Claudio; Londoño-Londoño, Julián; Medina, Sonia

2018-04-01

The agronomic production systems may affect the levels of food metabolites. Metabolomics approaches have been applied as useful tool for the characterization of fruit metabolome. In this study, metabolomics techniques were used to assess the differences in phytochemical composition between goldenberry samples produced by organic and conventional systems. To verify that the organic samples were free of pesticides, individual pesticides were analyzed. Principal component analysis showed a clear separation of goldenberry samples from two different farming systems. Via targeted metabolomics assays, whereby carotenoids and ascorbic acid were analyzed, not statistical differences between both crops were found. Conversely, untargeted metabolomics allowed us to identify two withanolides and one fatty acyl glycoside as tentative metabolites to differentiate goldenberry fruits, recording organic fruits higher amounts of these compounds than conventional samples. Hence, untargeted metabolomics technology could be suitable to research differences on phytochemicals under different agricultural management practices and to authenticate organic products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Halavaty, Andrei S. [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Kim, Youngchang [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Minasov, George; Shuvalova, Ludmilla; Dubrovska, Ievgeniia; Winsor, James [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States); Zhou, Min [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Onopriyenko, Olena; Skarina, Tatiana [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Papazisi, Leka; Kwon, Keehwan; Peterson, Scott N. [Center for Structural Genomics of Infectious Diseases, (United States); J. Craig Venter Institute, Rockville, MD 20850 (United States); Joachimiak, Andrzej [Center for Structural Genomics of Infectious Diseases, (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); University of Chicago, Chicago, IL 60637 (United States); Savchenko, Alexei [Center for Structural Genomics of Infectious Diseases, (United States); University of Toronto, Toronto, Ontario M5G 1L6 (Canada); Anderson, Wayne F., E-mail: wf-anderson@northwestern.edu [Center for Structural Genomics of Infectious Diseases, (United States); Northwestern University, Chicago, IL 60611 (United States)

2012-10-01

The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS{sub SA}), Vibrio cholerae (AcpS{sub VC}) and Bacillus anthracis (AcpS{sub BA}) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS{sub BA} is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpS{sub BA} may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP.

Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

International Nuclear Information System (INIS)

Halavaty, Andrei S.; Kim, Youngchang; Minasov, George; Shuvalova, Ludmilla; Dubrovska, Ievgeniia; Winsor, James; Zhou, Min; Onopriyenko, Olena; Skarina, Tatiana; Papazisi, Leka; Kwon, Keehwan; Peterson, Scott N.; Joachimiak, Andrzej; Savchenko, Alexei; Anderson, Wayne F.

2012-01-01

The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS SA ), Vibrio cholerae (AcpS VC ) and Bacillus anthracis (AcpS BA ) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS BA is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpS BA may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP

Cp*Co(III) Catalyzed Site-Selective C-H Activation of Unsymmetrical O-Acyl Oximes: Synthesis of Multisubstituted Isoquinolines from Terminal and Internal Alkynes.

Science.gov (United States)

Sun, Bo; Yoshino, Tatsuhiko; Kanai, Motomu; Matsunaga, Shigeki

2015-10-26

The synthesis of isoquinolines by site-selective C-H activation of O-acyl oximes with a Cp*Co(III) catalyst is described. In the presence of this catalyst, the C-H activation of various unsymmetrically substituted O-acyl oximes selectively occurred at the sterically less hindered site, and reactions with terminal as well as internal alkynes afforded the corresponding products in up to 98 % yield. Whereas the reactions catalyzed by the Cp*Co(III) system proceeded with high site selectivity (15:1 to 20:1), use of the corresponding Cp*Rh(III) catalysts led to low selectivities and/or yields when unsymmetrical O-acyl oximes and terminal alkynes were used. Deuterium labeling studies indicate a clear difference in the site selectivity of the C-H activation step under Cp*Co(III) and Cp*Rh(III) catalysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reducing Societal Obesity: Establishing a Separate Exercise Model through Studies of Group Behavior.

Science.gov (United States)

Puterbaugh, J S

2016-01-01

The past 50 years has brought attention to high and increasing levels of human obesity in most of the industrialized world. The medical profession has noticed, has evaluated, and has developed models for studying, preventing, and reversing obesity. The current model prescribes activity in specific quantities such as days, minutes, heart rates, and footfalls. Although decreased levels of activity have come from changes revolving around built environments and social networks, the existing medical model to lower body weights by increasing activity remains individually prescriptive. It is not working. The study of societal obesity precludes the individual and must involve group behavioral studies. Such studies necessitate acquiring separate tools and, therefore, require a significant change in the evaluation and treatment of obesity. Finding groups with common activities and lower levels of obesity would allow the development of new models of land use and encourage active lifestyles through shared interests.

Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

International Nuclear Information System (INIS)

Conocar, O.

2007-06-01

This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose

Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

Energy Technology Data Exchange (ETDEWEB)

Conocar, O

2007-06-15

This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose.

Deuterium-labelled N-acyl-l-homoserine lactones (AHLs) - inter-kingdom signalling molecules - synthesis, structural studies, and interactions with model lipid membranes

Energy Technology Data Exchange (ETDEWEB)

Jakubczyk, Dorota [Institute of Organic Chemistry, Karlsruhe Institute of Technology, Karlsruhe (Germany); Institute of Functional Interfaces, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Barth, Christoph; Anastassacos, Frances; Koelsch, Patrick; Schepers, Ute [Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Kubas, Adam; Fink, Karin [Institute of Nanotechnology, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Brenner-Weiss, Gerald [Institute of Functional Interfaces, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen (Germany); Braese, Stefan [Institute of Organic Chemistry, Karlsruhe Institute of Technology, Karlsruhe (Germany)

2012-04-15

N-Acyl-l-homoserine lactones (AHLs) are synthesized by Gram-negative bacteria. These quorum-sensing molecules play an important role in the context of bacterial infection and biofilm formation. They also allow communication between microorganisms and eukaryotic cells (inter-kingdom signalling). However, very little is known about the entire mechanism of those interactions. Precise structural studies are required to analyse the different AHL isomers as only one form is biologically most active. Theoretical studies combined with experimental infrared and Raman spectroscopic data are therefore undertaken to characterise the obtained compounds. To mimic interactions between AHL and cell membranes, we studied the insertion of AHL in supported lipid bilayers, using vibrational sum-frequency-generation spectroscopy. Deuterium-labelled AHLs were thus synthesized. Starting from readily available deuterated fatty acids, a two-step procedure towards deuterated N-acyl-l-homoserine lactones with varying chain lengths is described. This included the acylation of Meldrum's acid followed by amidation. Additionally, the detailed analytical evaluation of the products is presented herein. (orig.)

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

N-acyl-homoserine lactone uptake and systemic transport in barley rest upon active parts of the plant

Czech Academy of Sciences Publication Activity Database

Sieper, T.; Forczek, Sándor; Matucha, Miroslav; Kraemer, P.; Hartmann, A.; Schroeder, P.

2014-01-01

Roč. 201, č. 2 (2014), s. 545-555 ISSN 1469-8137 Institutional support: RVO:61389030 Keywords : barley (Hordeum vulgare) * monoclonal antibodies * N-acyl-homoserine lactones (HSLs) Subject RIV: EF - Botanics Impact factor: 6.545, year: 2013

Acyl-ACP thioesterases from castor (Ricinus communis L.): an enzymatic system appropriate for high rates of oil synthesis and accumulation.

Science.gov (United States)

Sánchez-García, Alicia; Moreno-Pérez, Antonio J; Muro-Pastor, Alicia M; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

2010-06-01

Acyl-acyl carrier protein (ACP) thioesterases are enzymes that terminate the intraplastidial fatty acid synthesis in plants by hydrolyzing the acyl-ACP intermediates and releasing free fatty acids to be incorporated into glycerolipids. These enzymes are classified in two families, FatA and FatB, which differ in amino acid sequence and substrate specificity. In the present work, both FatA and FatB thioesterases were cloned, sequenced and characterized from castor (Ricinus communis) seeds, a crop of high interest in oleochemistry. Single copies of FatA and FatB were found in castor resulting to be closely related with those of Jatropha curcas. The corresponding mature proteins were heterologously expressed in Escherichia coli for biochemical characterization after purification, resulting in high catalytic efficiency of RcFatA on oleoyl-ACP and palmitoleoyl-ACP and high efficiencies of RcFatB for oleoyl-ACP and palmitoyl-ACP. The expression profile of these genes displayed the highest levels in expanding tissues that typically are very active in lipid biosynthesis such as developing seed endosperm and young expanding leaves. The contribution of these two enzymes to the synthesis of castor oil is discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Clarification on the decarboxylation mechanism in KasA based on the protonation state of key residues in the acyl-enzyme state.

Science.gov (United States)

Lee, Wook; Engels, Bernd

2013-07-11

The β-ketoacyl ACP synthase I (KasA) is a promising drug target because it is essential for the survival of Mycobacterium tuberculosis , a causative agent of tuberculosis. It catalyzes a condensation reaction that comprises three steps. The resulting elongated acyl chains are subsequently needed for the cell wall construction. While the mechanism of the first step (acylation of Cys171 in the active site) is straightforward already, the second step (decarboxylation of malonyl substrate) has been controversial due to the difficulty in determining the correct protonation states of the involved residues (His311, His345, Lys340, Glu354). Available experimental data suggest three possible mechanisms which differ considerably. They are not consistent with each other because these studies could not be performed for KasA at the beginning of decarboxylation step (acyl-enzyme state of KasA). Instead, different mutants had to be used which are expected to resemble this situation. In this first computational study about this topic, we use the free energy perturbation (FEP) method to compute the relevant pKa values in the acyl-enzyme state of KasA and use molecular dynamics (MD) simulations to rationalize the results. Subsequent density functional theory (DFT)-based quantum mechanical/molecular mechanical (QM/MM) MD simulations and umbrella samplings have been used to disentangle the close relationships between the protonation states of the involved residues. By these simulations, we can address the preferred protonation states and roles of the residues involved in decarboxylation reaction, thereby suggesting the possible mechanism for the decarboxylation step.

Deficiency of acyl-CoA: Dihydroxyacetone phosphate acyltransferase in patients with Zellweger (cerebro-hepato-renal) syndrome

NARCIS (Netherlands)

Bosch, H. van den; Schutgens, R.B.H.; Romeyn, G.J.; Wanders, R.J.A.; Schrakamp, G.; Heymans, H.S.A.

1984-01-01

We have recently reported on plasmalogen deficiency in tissues and fibroblasts from patients with Zellweger syndrome. In this paper we have analyzed the activity of the first enzyme in the pathway leading to plasmalogen biosynthesis, i.e. acyl-CoA: dihydroxyacetone phosphate acyltransferase in

Muoniated acyl and thioacyl radicals

International Nuclear Information System (INIS)

McKenzie, Iain; Brodovitch, Jean-Claude; Ghandi, Khashayar; Percival, Paul W.

2006-01-01

The product of the reaction of muonium with tert-butylisocyanate was previously assigned as the muoniated tert-butylaminyl radical (I. McKenzie, J.-C. Brodovitch, K. Ghandi, S. Kecman, P. W. Percival, Physica B 326 (2003) 76). This assignment is incorrect since the muon and 14 N hyperfine-coupling constants (hfcc) of this radical would have the opposite sign, which is in conflict with the experimental results. The radical is now reassigned as the muoniated N-tert-butylcarbamoyl radical, based on the similarities between the experimental muon and 14 N hfcc and hfcc calculated at the UB3LYP/6-311G(d,p)//UB3LYP/EPR-III level. The large zero-point energy in the N-Mu bond results in the dissociation barrier of the muoniated N-tert-butylcarbamoyl radical being above the combined energy of the reactants, in contrast to the N-tert-butylcarbamoyl radical where the dissociation barrier lies below the combined energy of the reactants. The reaction of muonium with tert-butylisothiocyanate produced both conformers of the muoniated N-tert-butylthiocarbamoyl radical and their assignment was based on the similarities between the experimental and calculated muon hfcc. These are the first acyl and thioacyl radicals to be directly detected by muon spin spectroscopy

Muoniated acyl and thioacyl radicals

Energy Technology Data Exchange (ETDEWEB)

McKenzie, Iain [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Brodovitch, Jean-Claude [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Ghandi, Khashayar [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Percival, Paul W. [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada)]. E-mail: percival@sfu.ca

2006-03-31

The product of the reaction of muonium with tert-butylisocyanate was previously assigned as the muoniated tert-butylaminyl radical (I. McKenzie, J.-C. Brodovitch, K. Ghandi, S. Kecman, P. W. Percival, Physica B 326 (2003) 76). This assignment is incorrect since the muon and {sup 14}N hyperfine-coupling constants (hfcc) of this radical would have the opposite sign, which is in conflict with the experimental results. The radical is now reassigned as the muoniated N-tert-butylcarbamoyl radical, based on the similarities between the experimental muon and {sup 14}N hfcc and hfcc calculated at the UB3LYP/6-311G(d,p)//UB3LYP/EPR-III level. The large zero-point energy in the N-Mu bond results in the dissociation barrier of the muoniated N-tert-butylcarbamoyl radical being above the combined energy of the reactants, in contrast to the N-tert-butylcarbamoyl radical where the dissociation barrier lies below the combined energy of the reactants. The reaction of muonium with tert-butylisothiocyanate produced both conformers of the muoniated N-tert-butylthiocarbamoyl radical and their assignment was based on the similarities between the experimental and calculated muon hfcc. These are the first acyl and thioacyl radicals to be directly detected by muon spin spectroscopy.

Regulation of C. elegans fat uptake and storage by acyl-CoA synthase-3 is dependent on NR5A family nuclear hormone receptor nhr-25

DEFF Research Database (Denmark)

Mullaney, Brendan C; Blind, Raymond D; Lemieux, George A

2010-01-01

Acyl-CoA synthases are important for lipid synthesis and breakdown, generation of signaling molecules, and lipid modification of proteins, highlighting the challenge of understanding metabolic pathways within intact organisms. From a C. elegans mutagenesis screen, we found that loss of ACS-3...... mutant phenotypes require the nuclear hormone receptor NHR-25, a key regulator of C. elegans molting. Our findings suggest that ACS-3-derived long-chain fatty acyl-CoAs, perhaps incorporated into complex ligands such as phosphoinositides, modulate NHR-25 function, which in turn regulates an endocrine...... program of lipid uptake and synthesis. These results reveal a link between acyl-CoA synthase function and an NR5A family nuclear receptor in C. elegans....

Supercritical fluid chromatography and high temperature liquid chromatography for the group-type separation of diesel fuels and heavy gas oils

Energy Technology Data Exchange (ETDEWEB)

Paproski, R.E.

2008-07-01

This thesis investigated the use of unconventional extraction columns for separating diesel fuels by supercritical fluid chromatography (SFC) and for separating heavy gas oils by high temperature normal phase high performance liquid chromatography (HPLC). The purpose was to improve group-type resolution of the fuels, although these methods are also commonly used to determine the proportion of saturates, mono-, di-, tri-, and polyaromatic hydrocarbons. Higher mobile phase flow rates and unconventional column dimensions were also studied to obtain faster analysis times with both SFC and HPLC. The highest group-type resolutions with SFC were obtained by serially coupling bare titania and bare silica columns. Short packed columns and monolithic silica columns were compared at high carbon dioxide flow rates for reducing SFC analysis time, with shortpacked columns achieving 7-fold lower separation times while maintaining significant resolution. Three diesel samples had better resolution and analysis time. A thermally stable bare zircoma column for normal phase HPLC was studied at temperatures up to 200 degrees C. An increase in temperature resulted in lower retention of twenty five aromatic model compounds. Considerable improvements in peak shape, efficiency, group-type selectivity, and column re-equilibration times were obtained at elevated temperatures. At temperatures over 100 degrees C, indole and carbazole thermally decomposed in a hexane/dichloromethane mobile phase. The first order decomposition of carbazole was studied in further detail. A high resolution method was developed using titania and silica columns with valve-switching and dual gradients to separate 3 heavy gas oils. Separation was achieved in only 3 minutes using a fast analysis time method in a titania column at high flow rates.

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.

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

Up-regulation of hepatic Acyl CoA: Diacylglycerol acyltransferase-1 (DGAT-1) expression in nephrotic syndrome.

Science.gov (United States)

Vaziri, Nosratola D; Kim, Choong H; Phan, Dennis; Kim, Sara; Liang, Kaihui

2004-07-01

Nephrotic syndrome is associated with hypercholesterolemia, hypertriglyceridemia, and marked elevations of plasma low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). Hypertriglyceridemia in nephrotic syndrome is accompanied by increased hepatic fatty acid synthesis, elevated triglyceride secretion, as well as lipoprotein lipase, VLDL-receptor, and hepatic triglyceride lipase deficiencies, which lead to impaired clearance of triglyceride-rich lipoproteins. Acyl CoA: diacylglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl CoA to 1, 2-diacylglycerol to form triglyceride. Two distinct DGATs (DGAT-1 and DGAT2) have recently been identified in the liver and other tissues. The present study tested the hypothesis that the reported increase in hepatic triglyceride secretion in nephrotic syndrome may be caused by up-regulation of DGAT. Male Sprague-Dawley rats were rendered nephrotic by two sequential injections of puromycin aminonucleoside (130 mg/kg on day 1 and 60 mg/kg on day 14) and studied on day 30. Placebo-treated rats served as controls. Hepatic DGAT-1 and DGAT-2 mRNA abundance and enzymatic activity were measured. The nephrotic group exhibited heavy proteinuria, hypoalbuminemia, hypercholesterolemia, hypertriglyceridemia, and marked elevation of VLDL concentration. Hepatic DGAT-1 mRNA, DGAT-1, and total DGAT activity were significantly increased, whereas DGAT-2 mRNA abundance and activity were unchanged in the nephrotic rats compared to the control animals. The functional significance of elevation of DGAT activity was illustrated by the reduction in microsomal free fatty acid concentration in the liver of nephrotic animals. Nephrotic syndrome results in up-regulation of hepatic DGAT-1 expression and activity, which can potentially contribute to the associated hypertriglyceridemia by enhancing triglyceride synthesis. Thus, it appears that both depressed catabolism and increased synthetic capacity contribute to

Acyl chains of phospholipase D transphosphatidylation products in Arabidopsis cells: a study using multiple reaction monitoring mass spectrometry.

Directory of Open Access Journals (Sweden)

Dominique Rainteau

Full Text Available BACKGROUND: Phospholipases D (PLD are major components of signalling pathways in plant responses to some stresses and hormones. The product of PLD activity is phosphatidic acid (PA. PAs with different acyl chains do not have the same protein targets, so to understand the signalling role of PLD it is essential to analyze the composition of its PA products in the presence and absence of an elicitor. METHODOLOGY/PRINCIPAL FINDINGS: Potential PLD substrates and products were studied in Arabidopsis thaliana suspension cells treated with or without the hormone salicylic acid (SA. As PA can be produced by enzymes other than PLD, we analyzed phosphatidylbutanol (PBut, which is specifically produced by PLD in the presence of n-butanol. The acyl chain compositions of PBut and the major glycerophospholipids were determined by multiple reaction monitoring (MRM mass spectrometry. PBut profiles of untreated cells or cells treated with SA show an over-representation of 160/18:2- and 16:0/18:3-species compared to those of phosphatidylcholine and phosphatidylethanolamine either from bulk lipid extracts or from purified membrane fractions. When microsomal PLDs were used in in vitro assays, the resulting PBut profile matched exactly that of the substrate provided. Therefore there is a mismatch between the acyl chain compositions of putative substrates and the in vivo products of PLDs that is unlikely to reflect any selectivity of PLDs for the acyl chains of substrates. CONCLUSIONS: MRM mass spectrometry is a reliable technique to analyze PLD products. Our results suggest that PLD action in response to SA is not due to the production of a stress-specific molecular species, but that the level of PLD products per se is important. The over-representation of 160/18:2- and 16:0/18:3-species in PLD products when compared to putative substrates might be related to a regulatory role of the heterogeneous distribution of glycerophospholipids in membrane sub-domains.

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

High activity of iron containing metal-organic-framework in acylation of p-xylene with benzoyl chloride

Czech Academy of Sciences Publication Activity Database

Kurfiřtová, Lenka; Seo, Y.; K.; Hwang, Y. K.; Chang, J.; S.; Čejka, Jiří

2012-01-01

Roč. 179, č. 1 (2012), s. 85-90 ISSN 0920-5861 R&D Projects: GA ČR GA104/07/0383 Institutional research plan: CEZ:AV0Z40400503 Keywords : acylation * p-xylene * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.980, year: 2012

Ethylmalonic aciduria is associated with an amino acid variant of short chain acyl-coenzyme A dehydrogenase

DEFF Research Database (Denmark)

Corydon, M J; Gregersen, N; Lehnert, W

1996-01-01

Ethylmalonic aciduria is a common biochemical finding in patients with inborn errors of short chain fatty acid beta-oxidation. The urinary excretion of ethylmalonic acid (EMA) may stem from decreased oxidation by short chain acyl-CoA dehydrogenase (SCAD) of butyryl-CoA, which is alternatively...

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

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenemethanaminium, N-(3-aminopropyl...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzenemethanaminium, N-(3-aminopropyl)-N,N...

Effects of hematopoietic stem cell transplantation on acyl-CoA oxidase deficiency: a sibling comparison study

NARCIS (Netherlands)

Wang, Raymond Y.; Monuki, Edwin S.; Powers, James; Schwartz, Phillip H.; Watkins, Paul A.; Shi, Yang; Moser, Ann; Shrier, David A.; Waterham, Hans R.; Nugent, Diane J.; Abdenur, Jose E.

2014-01-01

Acyl-CoA oxidase (ACOX1) deficiency is a rare disorder of peroxisomal very-long chain fatty acid oxidation. No reports detailing attempted treatment, longitudinal imaging, or neuropathology exist. We describe the natural history of clinical symptoms and brain imaging in two siblings with ACOX1

An efficient and green synthesis of 1-indanone and 1-tetralone via intramolecular Friedel-Crafts acylation reaction

DEFF Research Database (Denmark)

Tran, Phuong Hoang; Huynh, Vy Hieu; Hansen, Poul Erik

2015-01-01

Metal-triflate-catalyzed intramolecular Friedel–Crafts acylation of 3-arylpropanoic and 4-arylbutanoic acids in triflate-anion ionic liquids under monomodal microwave irradiation is reported. The environmentally benign synthetic procedure allows the formation of cyclic ketones in good yields with...

Theoretical study on the nitration of methane by acyl nitrate catalyzed by H-ZSM5 zeolite.

Science.gov (United States)

Silva, Alexander Martins; Nascimento, Marco Antonio Chaer

2008-09-25

A theoretical study on the nitration of methane by acyl nitrate catalyzed by HZSM-5 zeolite is reported. The zeolite was represented by a "double ring" 20T cluster. The calculations were performed at the DFT/X3LYP/6-31G** and MP2/6-31G** levels. The first step of the mechanism involves the protonation of the acyl nitrate by the zeolite and the formation of a nitronium-like ion. The reaction proceeds through a concerted step with the attack of the methane molecule by the nitronium-like ion and the simultaneous transfer of a proton from the methane molecule to the zeolite, thus reconstructing the acidic site. The activation energies for the first and second steps of this reaction are, respectively, 14.09 and 10.14 kcal/mol at X3LYP/6-31G** level and 16.68 and 13.85 kcal/mol at the MP2/6-31G**.

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.

Patients with medium-chain acyl-coenzyme a dehydrogenase deficiency have impaired oxidation of fat during exercise but no effect of L-carnitine supplementation

DEFF Research Database (Denmark)

Madsen, K L; Preisler, N; Orngreen, M C

2013-01-01

It is not clear to what extent skeletal muscle is affected in patients with medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD). l-Carnitine is commonly used as a supplement in patients with MCADD, although its beneficial effect has not been verified.......It is not clear to what extent skeletal muscle is affected in patients with medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD). l-Carnitine is commonly used as a supplement in patients with MCADD, although its beneficial effect has not been verified....

Divorcing folding from function: how acylation affects the membrane-perturbing properties of an antimicrobial peptide

DEFF Research Database (Denmark)

Vad, Brian Stougaard; Thomsen, Line Aagot Hede; Bertelsen, Kresten

2010-01-01

Many small cationic peptides, which are unstructured in aqueous solution, have antimicrobial properties. These properties are assumed to be linked to their ability to permeabilize bacterial membranes, accompanied by the transition to an alpha-helical folding state. Here we show that there is no d......Many small cationic peptides, which are unstructured in aqueous solution, have antimicrobial properties. These properties are assumed to be linked to their ability to permeabilize bacterial membranes, accompanied by the transition to an alpha-helical folding state. Here we show...... that there is no direct link between folding of the antimicrobial peptide Novicidin (Nc) and its membrane permeabilization. N-terminal acylation with C8-C16 alkyl chains and the inclusion of anionic lipids both increase Nc's ability to form alpha-helical structure in the presence of vesicles. Nevertheless, both acylation......, this cannot rationalize our results since permeabilization and antimicrobial activities are observed well below concentrations where aggregation occurs. This suggests that significant induction of alpha-helical structure is not a prerequisite for membrane perturbation in this class of antimicrobial peptides...

Polymorphism in 'L' shaped lipids: structure of N-, O-diacylethanolamines with mixed acyl chains.

Science.gov (United States)

Tarafdar, Pradip K; Swamy, Musti J

2009-11-01

Although solid state polymorphism in lipids has been established by spectroscopic and calorimetric studies long ago, only in a few cases crystal structures of different polymorphs of the same compound have been reported, possibly due to difficulties in obtaining high quality single crystals of individual polymorphs. Recent studies show that N-, O-diacylethanolamines (DAEs) can be derived by the O-acylation of the stress-related lipids, the N-acylethanolamines under physiological conditions. In this study, two DAEs with mixed acyl chains, namely N-palmitoyl, O-octanoylethanolamine and N-palmitoyl, O-decanoylethanolamine have been synthesized and their three-dimensional structures were determined. Both the compounds were found to adopt 'L' shaped structures and exist in two polymorphic forms, alpha and beta. In the alpha form a mixed-type chain packing has been observed whereas in the beta form the chain packing is symmetric. Similar polymorphic forms are likely to exist in other 'L' shaped lipids such as 1,3-diacylglycerols and ceramides, where polymorphism has been detected earlier, but three-dimensional structures - which can give precise information about the packing at atomic resolution - have not been reported.

Acylation of proteins with myristic acid occurs cotranslationally

International Nuclear Information System (INIS)

Wilcox, C.; Hu, J.S.; Olson, E.N.

1987-01-01

Several proteins of viral and cellular origin are acylated with myristic acid early during their biogenesis. To investigate the possibility that myristylation occurred cotranslationally, the BC 3 H1 muscle cell line, which contains a broad array of myristylated proteins, was pulse-labeled with [ 3 H]myristic acid. Nascent polypeptide chains covalently associated with transfer RNA were isolated subsequently by ion-exchange chromatography. [ 3 H]Myristate was attached to nascent chains through an amide linkage and was identified by thin-layer chromatography after its release from nascent chains by acid methanolysis. Inhibition of cellular protein synthesis with puromycin resulted in cessation of [ 3 H]myristate-labeling of nascent chains, in agreement with the dependence of this modification on protein synthesis in vivo. These data represent a direct demonstration that myristylation of proteins is a cotranslational modification

Membrane binding of an acyl-lactoferricin B antimicrobial peptide from solid-state NMR experiments and molecular dynamics simulations.

Science.gov (United States)

Romo, Tod D; Bradney, Laura A; Greathouse, Denise V; Grossfield, Alan

2011-08-01

One approach to the growing health problem of antibiotic resistant bacteria is the development of antimicrobial peptides (AMPs) as alternative treatments. The mechanism by which these AMPs selectively attack the bacterial membrane is not well understood, but is believed to depend on differences in membrane lipid composition. N-acylation of the small amidated hexapeptide, RRWQWR-NH(2) (LfB6), derived from the 25 amino acid bovine lactoferricin (LfB25) can be an effective means to improve its antimicrobial properties. Here, we investigate the interactions of C6-LfB6, N-acylated with a 6 carbon fatty acid, with model lipid bilayers with two distinct compositions: 3:1 POPE:POPG (negatively charged) and POPC (zwitterionic). Results from solid-state (2)H and (31)P NMR experiments are compared with those from an ensemble of all-atom molecular dynamic simulations running in aggregate more than 8.6ms. (2)H NMR spectra reveal no change in the lipid acyl chain order when C6-LfB6 is bound to the negatively charged membrane and only a slight decrease in order when it is bound to the zwitterionic membrane. (31)P NMR spectra show no significant perturbation of the phosphate head groups of either lipid system in the presence of C6-LfB6. Molecular dynamic simulations show that for the negatively charged membrane, the peptide's arginines drive the initial association with the membrane, followed by attachment of the tryptophans at the membrane-water interface, and finally by the insertion of the C6 tails deep into the bilayer. In contrast, the C6 tail leads the association with the zwitterionic membrane, with the tryptophans and arginines associating with the membrane-water interface in roughly the same amount of time. We find similar patterns in the order parameters from our simulations. Moreover, we find in the simulations that the C6 tail can insert 1-2Å more deeply into the zwitterionic membrane and can exist in a wider range of angles than in the negatively charged membrane. We

Altered Energetics of Exercise Explain Risk of Rhabdomyolysis in Very Long-Chain Acyl-CoA Dehydrogenase Deficiency

NARCIS (Netherlands)

Diekman, E. F.; Visser, G.; Schmitz, J. P. J.; Nievelstein, R. A. J.; de Sain-van der Velden, M.; Wardrop, M.; van der Pol, W. L.; Houten, S. M.; van Riel, N. A. W.; Takken, T.; Jeneson, J. A. L.

2016-01-01

Rhabdomyolysis is common in very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) and other metabolic myopathies, but its pathogenic basis is poorly understood. Here, we show that prolonged bicycling exercise against a standardized moderate workload in VLCADD patients is associated with

Isolated 2-methylbutyrylglycinuria caused by short/branched-chain acyl-CoA dehydrogenase deficiency: identification of a new enzyme defect, resolution of its molecular basis, and evidence for distinct acyl-CoA dehydrogenases in isoleucine and valine metabolism

NARCIS (Netherlands)

Andresen, B. S.; Christensen, E.; Corydon, T. J.; Bross, P.; Pilgaard, B.; Wanders, R. J.; Ruiter, J. P.; Simonsen, H.; Winter, V.; Knudsen, I.; Schroeder, L. D.; Gregersen, N.; Skovby, F.

2000-01-01

Acyl-CoA dehydrogenase (ACAD) defects in isoleucine and valine catabolism have been proposed in clinically diverse patients with an abnormal pattern of metabolites in their urine, but they have not been proved enzymatically or genetically, and it is unknown whether one or two ACADs are involved. We

Sunflower (Helianthus annuus) fatty acid synthase complex: β-hydroxyacyl-[acyl carrier protein] dehydratase genes.

Science.gov (United States)

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

2016-02-01

Two sunflower hydroxyacyl-[acyl carrier protein] dehydratases evolved into two different isoenzymes showing distinctive expression levels and kinetics' efficiencies. β-Hydroxyacyl-[acyl carrier protein (ACP)]-dehydratase (HAD) is a component of the type II fatty acid synthase complex involved in 'de novo' fatty acid biosynthesis in plants. This complex, formed by four intraplastidial proteins, is responsible for the sequential condensation of two-carbon units, leading to 16- and 18-C acyl-ACP. HAD dehydrates 3-hydroxyacyl-ACP generating trans-2-enoyl-ACP. With the aim of a further understanding of fatty acid biosynthesis in sunflower (Helianthus annuus) seeds, two β-hydroxyacyl-[ACP] dehydratase genes have been cloned from developing seeds, HaHAD1 (GenBank HM044767) and HaHAD2 (GenBank GU595454). Genomic DNA gel blot analyses suggest that both are single copy genes. Differences in their expression patterns across plant tissues were detected. Higher levels of HaHAD2 in the initial stages of seed development inferred its key role in seed storage fatty acid synthesis. That HaHAD1 expression levels remained constant across most tissues suggest a housekeeping function. Heterologous expression of these genes in E. coli confirmed both proteins were functional and able to interact with the bacterial complex 'in vivo'. The large increase of saturated fatty acids in cells expressing HaHAD1 and HaHAD2 supports the idea that these HAD genes are closely related to the E. coli FabZ gene. The proposed three-dimensional models of HaHAD1 and HaHAD2 revealed differences at the entrance to the catalytic tunnel attributable to Phe166/Val1159, respectively. HaHAD1 F166V was generated to study the function of this residue. The 'in vitro' enzymatic characterization of the three HAD proteins demonstrated all were active, with the mutant having intermediate K m and V max values to the wild-type proteins.

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....

Decreased ghrelin and des-acyl ghrelin plasma levels in patients affected by pharmacoresistant epilepsy and maintained on the ketogenic diet.

Science.gov (United States)

Marchiò, Maddalena; Roli, Laura; Giordano, Carmela; Trenti, Tommaso; Guerra, Azzurra; Biagini, Giuseppe

2018-03-23

The gastric hormones ghrelin and des-acyl ghrelin have been found to be altered in patients treated with antiepileptic drugs. However, it is unknown if these hormones could be modified by other antiepileptic treatments, such as the ketogenic diet. Especially, a reduction in ghrelin levels could be relevant in view of the growth retardation observed under ketogenic diet treatment. For this reason we aimed to determine the changes in ghrelin and des-acyl ghrelin plasma levels in children affected by refractory epilepsy and treated with the ketogenic diet up to 90 days. Both peptides were measured by immunoassays in plasma obtained from 16 children. Ghrelin plasma levels were progressively reduced by the ketogenic diet, reaching a minimum corresponding to 42% of basal levels after 90 days of ketogenic diet (P ketogenic diet (P ketogenic diet administration. Ghrelin and des-acyl ghrelin are downregulated by the ketogenic diet in children affected by refractory epilepsy. Although no significant changes in growth were observed during the short time period of our investigation, the reduction in ghrelin availability may explain the reported growth retardation found in children treated with the ketogenic diet in the long-term. Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

A new approach to group separation of coals

Energy Technology Data Exchange (ETDEWEB)

Zhi-Hong Qin; Zhi-Min Zong; Chun Jiang; Hao Sun; Li-Li Zhou; Xian-Yong Wei [China University of Mining and University, Jiangsu (China). School of Chemical Engineering

2005-07-01

Three coal samples were extracted with carbon disulfide/N-methyl-2-pyrrolidinone (CS{sub 2}/NMP) mixed solvent. The extraction solutions were separated to three layers: insoluble fraction (under layer), CS{sub 2} solution (middle layer) and water/NMP solution (upper layer) by water addition. Most of NMP was concentrated to the upper layer. 7 refs., 3 figs., 3 tabs.

Abnormal mitochondrial bioenergetics and heart rate dysfunction in mice lacking very-long-chain acyl-CoA dehydrogenase

NARCIS (Netherlands)

Exil, VJ; Gardner, CD; Rottman, JN; Sims, H; Bartelds, B; Khuchua, Z; Sindhal, R; Ni, GM; Strauss, AW

Mitochondrial very-long-chain acyl-CoA dehydrogenase ( VLCAD) deficiency is associated with severe hypoglycemia, cardiac dysfunction, and sudden death in neonates and children. Sudden death is common, but the underlying mechanisms are not fully understood. We report on a mouse model of VLCAD

The domain-specific and temperature-dependent protein misfolding phenotype of variant medium-chain acyl-CoA dehydrogenase

NARCIS (Netherlands)

Jank, Johanna M.; Maier, Esther M.; Reiβ, Dunja D.; Haslbeck, Martin; Kemter, Kristina F.; Truger, Marietta S.; Sommerhoff, Christian P.; Ferdinandusse, Sacha; Wanders, Ronald J.; Gersting, Søren W.; Muntau, Ania C.

2014-01-01

The implementation of expanded newborn screening programs reduced mortality and morbidity in medium-chain acyl-CoA dehydrogenase deficiency (MCADD) caused by mutations in the ACADM gene. However, the disease is still potentially fatal. Missense induced MCADD is a protein misfolding disease with a

Separation method for ions of elements of the III., IV., VI. and VIII. groups of periodical system

International Nuclear Information System (INIS)

Marhol, M.

1973-01-01

The method is presented of separating the ions of the elements of the periodic system groups III, IV, and VIII by ion exchangers. The ions are complex-bonded to a new type of ion exchanger consisting of the polycondensates of phenol with aldehydes or ketones and containing an atom of phosphorus, arsenic or antimony with an atom of sulphur or oxygen in a complex bond. The polymers of compounds containing a double bond, e.g., of butadiene, polyvinyl alcohol, polyethylene, polypropylene, and the compounds of styrene with fural may also be used for this purpose. The method is demonstrated on a case of uranium and heavy metal concentration and the separation thereof from waste waters. (L.K.)

Acid catalyzed solvent free synthesis of new 1-acyl-4-benzhydryl substituted pyrazoles

International Nuclear Information System (INIS)

Sher, M.; Kausar, T.; Riaz, N.; Sharif, A.

2016-01-01

A convenient, cost effective and environmentally benign methodology has been developed, which delivered fourteen new 1-acyl-4-benzhyrdyl substituted pyrazole derivatives under solvent free conditions. Target compounds were synthesized in good to excellent yields simply by grinding reactants in a pestle and mortar with catalytic amount of conc. H/sub 2/SO/sub 4/. All the newly formed compounds were fully characterized with the help of detailed spectroscopic techniques including FTIR, NMR and GC-MS. (author)

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

Conserved residues and their role in the structure, function, and stability of acyl-coenzyme A binding protein

DEFF Research Database (Denmark)

Kragelund, B B; Poulsen, K; Andersen, K V

1999-01-01

In the family of acyl-coenzyme A binding proteins, a subset of 26 sequence sites are identical in all eukaryotes and conserved throughout evolution of the eukaryotic kingdoms. In the context of the bovine protein, the importance of these 26 sequence positions for structure, function, stability...

Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation.

Science.gov (United States)

Casas-Godoy, Leticia; Arrizon, Javier; Arrieta-Baez, Daniel; Plou, Francisco J; Sandoval, Georgina

2016-08-01

Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase

Directory of Open Access Journals (Sweden)

Thomas Lanyon-Hogg

2016-06-01

Full Text Available In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed “RU-SKI” class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a, RU-SKI 43 (9b, RU-SKI 101 (9c, and RU-SKI 201 (9d were profiled for activity in the related article “Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase” (Lanyon-Hogg et al., 2015 [1]. 1H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors.

Acyl/free carnitine ratio is a risk factor for hepatic steatosis after pancreatoduodenectomy and total pancreatectomy.

Science.gov (United States)

Nakamura, Masafumi; Nakata, Kohei; Matsumoto, Hideo; Ohtsuka, Takao; Yoshida, Koji; Tokunaga, Shoji; Hino, Keisuke

Hepatic steatosis, one of the most frequent long-term complications of pancreatectomy, influences not only hepatic function but also survival rate. However, its risk factors and pathogenesis have not been established. The purpose of this study was to clarify the risk factors for hepatic steatosis after pancreatectomy. In this retrospective study of 21 patients who had undergone pancreatectomy (19 cases of pancreatoduodenectomy and 2 cases of total pancreatectomy), serum carnitine concentrations, fractions of carnitine, and hepatic attenuation on computed tomography images were analyzed with the aim of identifying risk factors for hepatic steatosis. Thirteen (61.9%) of the 21 patients were diagnosed as having hypocarnitinemia after pancreatectomy. Average hepatic attenuation was as low as 42.2HU (±21.3 SD). A high ratio of acyl/free carnitine was associated with less pronounced hepatic attenuation according to both univariate (P pancreatectomy in some patients. The statistical analyses suggest that a high ratio of acyl/free carnitine is an independent risk factor for hepatic steatosis after pancreatectomy. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

A General and Selective Rhodium-Catalyzed Reduction of Amides, N-Acyl Amino Esters, and Dipeptides Using Phenylsilane.

Science.gov (United States)

Das, Shoubhik; Li, Yuehui; Lu, Liang-Qiu; Junge, Kathrin; Beller, Matthias

2016-05-17

This article describes a selective reduction of functionalized amides, including N-acyl amino esters and dipeptides, to the corresponding amines using simple [Rh(acac)(cod)]. The catalyst shows excellent chemoselectivity in the presence of different sensitive functional moieties. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications.

Science.gov (United States)

Harry-O'kuru, Rogers E; Biresaw, Girma; Gordon, Sherald; Xu, Jingyuan

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.

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.

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

Science.gov (United States)

Ho, Jessica S.; Geske, Grant D.; Blackwell, Helen E.; Ruby, Edward G.

2014-01-01

SUMMARY Quorum sensing, a group behavior coordinated by a diffusible pheromone signal and a cognate receptor, is typical of bacteria that form symbioses with plants and animals. LuxIR-type acyl homoserine-lactone (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 signaling 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 analogs 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. PMID:24191970

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

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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.

Acylation Enhances, but Is Not Required for, the Cytotoxic Activity of Mannheimia haemolytica Leukotoxin in Bighorn Sheep.

Science.gov (United States)

Batra, Sai A; Shanthalingam, Sudarvili; Munske, Gerhard R; Raghavan, Bindu; Kugadas, Abirami; Bavanthasivam, Jegarubee; Highlander, Sarah K; Srikumaran, Subramaniam

2015-10-01

Mannheimia haemolytica causes pneumonia in domestic and wild ruminants. Leukotoxin (Lkt) is the most important virulence factor of the bacterium. It is encoded within the four-gene lktCABD operon: lktA encodes the structural protoxin, and lktC encodes a trans-acylase that adds fatty acid chains to internal lysine residues in the protoxin, which is then secreted from the cell by a type 1 secretion system apparatus encoded by lktB and lktD. It has been reported that LktC-mediated acylation is necessary for the biological effects of the toxin. However, an LktC mutant that we developed previously was only partially attenuated in its virulence for cattle. The objective of this study was to elucidate the role of LktC-mediated acylation in Lkt-induced cytotoxicity. We performed this study in bighorn sheep (Ovis canadensis) (BHS), since they are highly susceptible to M. haemolytica infection. The LktC mutant caused fatal pneumonia in 40% of inoculated BHS. On necropsy, a large number of necrotic polymorphonuclear leukocytes (PMNs) were observed in the lungs. Lkt from the mutant was cytotoxic to BHS PMNs in an in vitro cytotoxicity assay. Flow cytometric analysis of mutant Lkt-treated PMNs revealed the induction of necrosis. Scanning electron microscopic analysis revealed the presence of pores and blebs on mutant-Lkt-treated PMNs. Mass spectrometric analysis confirmed that the mutant secreted an unacylated Lkt. Taken together, these results suggest that acylation is not necessary for the cytotoxic activity of M. haemolytica Lkt but that it enhances the potency of the toxin. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Purification of a jojoba embryo fatty acyl-coenzyme A reductase and expression of its cDNA in high erucic acid rapeseed.

Science.gov (United States)

Metz, J G; Pollard, M R; Anderson, L; Hayes, T R; Lassner, M W

2000-03-01

The jojoba (Simmondsia chinensis) plant produces esters of long-chain alcohols and fatty acids (waxes) as a seed lipid energy reserve. This is in contrast to the triglycerides found in seeds of other plants. We purified an alcohol-forming fatty acyl-coenzyme A reductase (FAR) from developing embryos and cloned the cDNA encoding the enzyme. Expression of a cDNA in Escherichia coli confers FAR activity upon those cells and results in the accumulation of fatty alcohols. The FAR sequence shows significant homology to an Arabidopsis protein of unknown function that is essential for pollen development. When the jojoba FAR cDNA is expressed in embryos of Brassica napus, long-chain alcohols can be detected in transmethylated seed oils. Resynthesis of the gene to reduce its A plus T content resulted in increased levels of alcohol production. In addition to free alcohols, novel wax esters were detected in the transgenic seed oils. In vitro assays revealed that B. napus embryos have an endogenous fatty acyl-coenzyme A: fatty alcohol acyl-transferase activity that could account for this wax synthesis. Thus, introduction of a single cDNA into B. napus results in a redirection of a portion of seed oil synthesis from triglycerides to waxes.

Analysis of amino acids and acyl carnitine profiles in low birth weight, preterm, and small for gestational age neonates.

Science.gov (United States)

Liu, Qian; Wu, Jing; Shen, Wen; Wei, Ran; Jiang, Jianhui; Liang, Jinqun; Chen, Min; Zhong, Mei; Yin, Aihua

2017-11-01

To analyze the amino acids (AA) and acyl carnitine (AC) profiles in dry blood spot (DBS) specimens of low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA), and to compare the concentration difference of AA and AC with those without above. This is a retrospectively study. Eight thousand nine hundred and seventy-nine uncomplicated pregnant newborns were enrolled into the study. DBS were collected on the third day of life, and concentrations of 11 types of AA, free carnitine and 30 types of AC were detected by using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS). Shapiro-Wilk test and Kruskal-Wallis rank test were applied in statistical analysis. Concentrations of most AA and AC in infants born in SGA were significantly higher than those in non-SGA group, while lower in LBW and PTB groups than those in non-LBW and non-PTB groups (p < 0.05). The difference of concentration of AA and AC in the subgroups suggested there may be a dysutilization of AA and AC in SGA, but an inborn insufficient of AA and AC in LBW and PTB neonates.

Evaluation of Effect of Microwave Irradiation on Syntheses and Reactions of Some New 3-Acyl-methylchromones

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Mikulas Furdik

1998-03-01

Full Text Available The 3-Acyl-2-R-methylchromones (R = H, ArO, C6H4(CO2N were prepared in good yields by different methods from 2-hydroxyaroylacetone derivatives. Some subsequent reactions of these compounds with hydroxylamine and 3-formylchromones are described. The effect of microwave irradation on some condensation reactions was studied.

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....

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

Identification of the human mitochondrial FAD transporter and its potential role in multiple acyl-CoA dehydrogenase deficiency

NARCIS (Netherlands)

Spaan, András N.; Ijlst, Lodewijk; van Roermund, Carlo W. T.; Wijburg, Frits A.; Wanders, Ronald J. A.; Waterham, Hans R.

2005-01-01

Multiple acyl-CoA dehydrogenase deficiency (MADD) or glutaric aciduria type II (GAII) is most often caused by mutations in the genes encoding the alpha- or beta-subunit of electron transfer flavoprotein (ETF) or electron transfer flavoprotein dehydrogenase (ETF-DH). Since not all patients have

Immunomodulatory N-acyl Dopamine Glycosides from the Icelandic Marine Sponge Myxilla incrustans Collected at a Hydrothermal Vent Site

DEFF Research Database (Denmark)

Einarsdottir, Eydis; Liu, Hong Bing; Freysdottir, Jona

2016-01-01

A chemical investigation of the sponge (Porifera) Myxilla incrustans collected from the unique submarine hydrothermal vent site Strytan, North of Iceland, revealed a novel family of closely related N-acyl dopamine glycosides. Three new compounds, myxillin A (1), B (2) and C (3), were isolated...

Profiling of acylated homoserine lactones of Vibrio anguillarum in vitro and in vivo: influence of growth conditions and serotype

DEFF Research Database (Denmark)

Buchholtz, Chrstiane; Nielsen, Kristian Fog; L. Milton, Debra

2006-01-01

Vibrio anguillarum produces several interlinked acylated homoserine lactone (AHL) signal molecules which may Vibrio anguillarum produces several interlinked acylated homoserine lactone (AHL) signal molecules which may influence expression of its virulence factors such as exoprotease production...... concentration) has little influence on the AHL-profile. Most strains produced N-(3-oxodecanoyl)-l-homoserine lactone (3-oxo-C10-HSL) and N-(3-hydroxy-hexanoyl)-l-homoserine lactone (3-hydroxy-C6-HSL) as the dominant molecules. Also, two spots with AHL activity appeared on TLC plates, which could...... not be identified as AHL structures. Trace amounts of N-(3-hydroxy-octanoyl)-l-homoserine lactone, N-(3-hydroxy-decanoyl)-l-homoserine lactone and N-(3-hydroxy-dodecanoyl)-l-homoserine lactone (3-hydroxy-C8-HSL, 3-hydroxy-C10-HSL and 3-oxo-C12-HSL, respectively) were also detected by HPLC-HRMS analysis from...

A New Acylated Flavonol Glycoside from Chenopodium foliosum

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Zlatina Kokanova-Nedialkova, , , , , and

2014-07-01

Full Text Available A new acylated flavonol glycoside, namely gomphrenol-3-O-( 5 '''-O-E-feruloyl-β-D-apiofuranosyl-(1→2[β-D-glucopyranosyl-(1→6]-β-D-glucopyranoside (1 was isolated from the aerial parts of Chenopodium foliosum Asch. The structure of 1 was determined by means of spectroscopic methods (1D and 2D NMR, UV, IR, and HRESIMS. Radical scavenging and antioxidant activities of 1 were established using DPPH and ABTS radicals, FRAP assay and inhibition of lipid peroxidation (LP in linoleic acid system by the ferric thiocyanate method. Compound 1 showed low activity (DPPH and ABTS or lack of activity (FRAP and LP. In combination with CCl 4, 1 reduced the damage caused by the hepatotoxic agent and preserved cell viability and GSH level, decreased LDH leakage and reduced lipid damage. Effects were concentration dependent, most visible at the highest concentration (100 µg/m L , and similar to those of silymarin .

Intra-group separation of rare earths using new organic phosphorus ligands

International Nuclear Information System (INIS)

Hadic, Sanela

2017-01-01

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 ("1H-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. After

Cloning and characterization of human very-long-chain acyl-CoA dehydrogenase cDNA, chromosomal assignment of the gene and identification in four patients of nine different mutations within the VLCAD gene

DEFF Research Database (Denmark)

Andresen, B S; Bross, P; Vianey-Saban, C

1996-01-01

Very-long-chain acyl-CoA dehydrogenase (VLCAD) is one of four straight-chain acyl-CoA dehydrogenase (ACD) enzymes, which are all nuclear encoded mitochondrial flavoproteins catalyzing the initial step in fatty acid beta-oxidation. We have used the very fast, Rapid Amplification of cDNA Ends (RACE...

Validation of limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring - is a separate validation group required?

NARCIS (Netherlands)

Proost, J. H.

Objective: Limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring are usually validated in a separate group of patients, according to published guidelines. The aim of this study is to evaluate the validation of LSM by comparing independent validation with cross-validation

Indium triflate in 1-isobutyl-3-methylimidazolium dihydrogenphosphate: an efficient and green catalytic system for Friedel-Crafts acylation

DEFF Research Database (Denmark)

Tran, Phuong Hoang; Hoang, Huy Manh; Chau, Duy-Khiem Nguyen

2015-01-01

Indium triflate in the ionic liquid, 1-isobutyl-3-methylimidazolium dihydrogen phosphate ([i-BMIM]H2PO4), was found to show enhanced catalytic activity in the Friedel–Crafts acylation of various aromatic compounds with acid anhydrides. The catalytic system was easily recovered and reused without...

Molecular diagnosis and characterization of medium-chain acyl-CoA dehydrogenase deficiency

DEFF Research Database (Denmark)

Andresen, B S; Bross, P; Jensen, T G

1995-01-01

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common defect in mitochondrial beta-oxidation in humans. It is an autosomal recessive disorder which usually presents in infancy. The disease manifests itself in periods of metabolic stress to the beta-oxidation system and may...... of correct enzyme structure, and does not directly affect the catalytically active regions of the enzyme. We find that our diagnostic set up, consisting of an initial testing by the G985 assay, followed by semi-automated sequencing of DNA from those patients who were indicated to be compound heterozygous...

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...

Regiospecific synthesis of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters (FAMEs)

Energy Technology Data Exchange (ETDEWEB)

Beck, Paulo; Santos, Juliane M. dos; D' Oca, Marcelo G. M.; Piovesan, Luciana A., E-mail: lpiovesan@gmail.com [Universidade Federal do Rio Grande (UFRS), RS (Brazil). Escola de Quimica e Alimentos; Kuhn, Bruna L.; Moreira, Dayse N.; Flores, Alex F.C.; Martins, Marcos A.P. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Quimica

2012-11-15

A series of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters was synthesized by the cyclo condensation of respective fatty hydrazides with 4-alkoxy- 1,1,1-trial omethyl-3-alquen-2-ones. Efficient and regiospecific cyclizations catalyzed by BF{sub 3}-MeOH gave the desired products in good to excellent yields and at high purity. (author)

Short-chain Acyl-CoA dehydrogenase deficiency: studies in a large family adding to the complexity of the disorder

NARCIS (Netherlands)

Bok, Levinus A.; Vreken, Peter; Wijburg, Frits A.; Wanders, Ronald J. A.; Gregersen, Niels; Corydon, Morten J.; Waterham, Hans R.; Duran, Marinus

2003-01-01

OBJECTIVE: To understand the expanding clinical and biochemical spectrum of short-chain acyl-CoA dehydrogenase (SCAD) deficiency, the impact of which is not fully understood. STUDY DESIGN: We studied a family with SCAD deficiency and determined urinary ethylmalonic acid excretion, plasma

Production of N-acyl-L-homoserine lactones by P. aeruginosa isolates from chronic lung infections associated with cystic fibrosis

DEFF Research Database (Denmark)

Geisenberger, O; Givskov, M; Riedel, K

2000-01-01

The N-acyl-L-homoserine lactones (AHLs) produced by sequential Pseudomonas aeruginosa isolates from chronically infected patients with cystic fibrosis were analyzed by thin-layer chromatography. It is demonstrated that both the amounts and the types of molecules synthesized by isolates from...

Plasma concentrations of acyl-ghrelin are associated with average daily gain and feeding behavior in grow-finish pigs

Science.gov (United States)

Feeding behavior is an important component of growth and feed efficiency in swine. Acyl-ghrelin is a peptide produced in the stomach that is orexigenic. The role of ghrelin in regulating feeding behavior in swine under commercial conditions is unknown. The objectives of this study were to determine ...

Metal complexation by tripodal N-Acyl(thio)urea and picolin(thio)amide compounds: synthesis/extraction and potentiometric studies

NARCIS (Netherlands)

Reinoso garcia, M.M.; Dijkman, Arjan; Verboom, Willem; Reinhoudt, David; Malinowska, Elzbieta; Wojciechowska, Dorota; Pietrzak, Mariusz; Selucky, Pavel

2005-01-01

The synthesis and binding properties towards different cations of a series of tripodal ligands functionalized with N-acyl(thio)urea and picolin(thio)amide moieties are described. For the extraction of Am3+ and Eu3+ the compounds are not efficient. However, N-acylurea derivative 10 exhibit a

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...... proteins. Bacterial strains harboring this green fluorescent sensor detected a broad spectrum of AHL molecules and were capable of sensing the presence of 5 nM N-3-oxohexanoyl-L-homoserine lactone in the surroundings. In combination with epifluorescent microscopy, the sensitivity of the sensor enabled AHL...

Deciphering the acylation pattern of Yersinia enterocolitica lipid A.

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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

Synthesis of acyl analogues of coniferyl alcohol and their antimycobacterial activity

International Nuclear Information System (INIS)

Begum, S.; Siddiqui, B.S.

2013-01-01

In search of new anti-mycobacterial agents seven acyl and one benzyl derivatives of coniferyl alcohol were synthesized and evaluated along with coniferyl alcohol for antitubercular activity against Mycobacterium tuberculosis H37Rv (Mtb) in vitro. Four compounds (3-6) showed greater activity than the parent compound and inhibited MTB with IC/sub 90/ 9.11, 8.92, 4.28 and 3.01 micro g/mL respectively. Compound 6, the most potent compound in vitro exhibited CC/sub 50/ 10.216 micro g/mL in VERO cells with selectivity index 3.394. Reference compounds used were rifampin and isoniazid and had IC/sub 90/ 0.0031 and 0.063 micro g/mL respectively. (author)

Tandem mass spectrometry screening for very long-chain acyl-CoA dehydrogenase deficiency: the value of second-tier enzyme testing.

Science.gov (United States)

Spiekerkoetter, Ute; Haussmann, Ulrike; Mueller, Martina; ter Veld, Frank; Stehn, Maren; Santer, Rene; Lukacs, Zoltan

2010-10-01

To evaluate newborn screening (NBS) for very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), we further characterized newborns with elevation of one or all C14-carnitine derivatives on NBS from a total of 90 338 newborns. Palmitoyl-CoA oxidation was performed in lymphocytes to define very long-chain acyl-CoA dehydrogenase function. Molecular analysis followed in children with residual activitiesvalues and acylcarnitine ratios did not allow correct identification of the newborn as a patient with VLCADD. Reliable diagnosis is not feasible with acylcarnitine analysis alone. Enzyme analysis in lymphocytes is a reliable and rapid method for correctly assessing all newborns with VLCADD and should be carried out in all newborns identified during the first screening, regardless of the results of a later acylcarnitine profile. Copyright (c) 2010 Mosby, Inc. All rights reserved.

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.

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

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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.

The hexanoyl-CoA precursor for cannabinoid biosynthesis is formed by an acyl-activating enzyme in Cannabis sativa trichomes.

Science.gov (United States)

Stout, Jake M; Boubakir, Zakia; Ambrose, Stephen J; Purves, Randy W; Page, Jonathan E

2012-08-01

The psychoactive and analgesic cannabinoids (e.g. Δ(9) -tetrahydrocannabinol (THC)) in Cannabis sativa are formed from the short-chain fatty acyl-coenzyme A (CoA) precursor hexanoyl-CoA. Cannabinoids are synthesized in glandular trichomes present mainly on female flowers. We quantified hexanoyl-CoA using LC-MS/MS and found levels of 15.5 pmol g(-1) fresh weight in female hemp flowers with lower amounts in leaves, stems and roots. This pattern parallels the accumulation of the end-product cannabinoid, cannabidiolic acid (CBDA). To search for the acyl-activating enzyme (AAE) that synthesizes hexanoyl-CoA from hexanoate, we analyzed the transcriptome of isolated glandular trichomes. We identified 11 unigenes that encoded putative AAEs including CsAAE1, which shows high transcript abundance in glandular trichomes. In vitro assays showed that recombinant CsAAE1 activates hexanoate and other short- and medium-chained fatty acids. This activity and the trichome-specific expression of CsAAE1 suggest that it is the hexanoyl-CoA synthetase that supplies the cannabinoid pathway. CsAAE3 encodes a peroxisomal enzyme that activates a variety of fatty acid substrates including hexanoate. Although phylogenetic analysis showed that CsAAE1 groups with peroxisomal AAEs, it lacked a peroxisome targeting sequence 1 (PTS1) and localized to the cytoplasm. We suggest that CsAAE1 may have been recruited to the cannabinoid pathway through the loss of its PTS1, thereby redirecting it to the cytoplasm. To probe the origin of hexanoate, we analyzed the trichome expressed sequence tag (EST) dataset for enzymes of fatty acid metabolism. The high abundance of transcripts that encode desaturases and a lipoxygenase suggests that hexanoate may be formed through a pathway that involves the oxygenation and breakdown of unsaturated fatty acids. © 2012 National Research Council of Canada. The Plant Journal © 2012 Blackwell Publishing Ltd.

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.

Equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) in 14 horses associated with ingestion of Maple leaves (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum).

Science.gov (United States)

van der Kolk, J H; Wijnberg, I D; Westermann, C M; Dorland, L; de Sain-van der Velden, M G M; Kranenburg, L C; Duran, M; Dijkstra, J A; van der Lugt, J J; Wanders, R J A; Gruys, E

2010-01-01

This case-series describes fourteen horses suspected of equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) also known as atypical myopathy of which seven cases were confirmed biochemically with all horses having had access to leaves of the Maple tree (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum). Assessment of organic acids, glycine conjugates, and acylcarnitines in urine was regarded as gold standard in the biochemical diagnosis of equine acquired multiple acyl-CoA dehydrogenase deficiency. Copyright © 2010 Elsevier Inc. All rights reserved.

Separation of Acetylene from Carbon Dioxide and Ethylene by a Water-Stable Microporous Metal-Organic Framework with Aligned Imidazolium Groups inside the Channels.

Science.gov (United States)

Lee, Jaechul; Chuah, Chong Yang; Kim, Jaheon; Kim, Youngsuk; Ko, Nakeun; Seo, Younggyu; Kim, Kimoon; Bae, Tae Hyun; Lee, Eunsung

2018-04-24

Separation of acetylene from carbon dioxide and ethylene is challenging in view of their similar sizes and physical properties. Metal-organic frameworks (MOFs) in general are strong candidates for these separations owing to the presence of functional pore surfaces that can selectively capture a specific target molecule. Here, we report a novel 3D microporous cationic framework named JCM-1. This structure possesses imidazolium functional groups on the pore surfaces and pyrazolate as a metal binding group, which is well known to form strong metal-to-ligand bonds. The selective sorption of acetylene over carbon dioxide and ethylene in JCM-1 was successfully demonstrated by equilibrium gas adsorption analysis as well as dynamic breakthrough measurement. Furthermore, its excellent hydrolytic stability makes the separation processes highly recyclable without a substantial loss in acetylene uptake capacity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Cellulose-polyhydroxylated fatty acid ester-based bioplastics with tuning properties: Acylation via a mixed anhydride system.

Science.gov (United States)

Heredia-Guerrero, José A; Goldoni, Luca; Benítez, José J; Davis, Alexander; Ceseracciu, Luca; Cingolani, Roberto; Bayer, Ilker S; Heinze, Thomas; Koschella, Andreas; Heredia, Antonio; Athanassiou, Athanassia

2017-10-01

The synthesis of microcrystalline cellulose (MCC) and 9,10,16-hydroxyhexadecanoic (aleuritic) acid ester-based bioplastics was investigated through acylation in a mixed anhydride (trifluoroacetic acid (TFA)/trifluoroacetic acid anhydride (TFAA)), chloroform co-solvent system. The effects of chemical interactions and the molar ratio of aleuritic acid to the anhydroglucose unit (AGU) of cellulose were investigated. The degree of substitution (DS) of new polymers were characterized by two-dimensional solution-state NMR and ranged from 0.51 to 2.60. The chemical analysis by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) confirmed the presence of aleuritate groups in the structure induces the formation of new H-bond networks. The tensile analysis and the contact angle measurement confirmed the ductile behavior and the hydrophobicity of the prepared bioplastics. By increasing the aleuritate amounts, the glass transition temperature decreased and the solubility of bioplastic films in most common solvents was improved. Furthermore, this new polymer exhibits similar properties compared to commercial cellulose derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Both acyl and des-acyl ghrelin regulate adiposity and glucose metabolism via central nervous system ghrelin receptors.

Science.gov (United States)

Heppner, Kristy M; Piechowski, Carolin L; Müller, Anne; Ottaway, Nickki; Sisley, Stephanie; Smiley, David L; Habegger, Kirk M; Pfluger, Paul T; Dimarchi, Richard; Biebermann, Heike; Tschöp, Matthias H; Sandoval, Darleen A; Perez-Tilve, Diego

2014-01-01

Growth hormone secretagogue receptors (GHSRs) in the central nervous system (CNS) mediate hyperphagia and adiposity induced by acyl ghrelin (AG). Evidence suggests that des-AG (dAG) has biological activity through GHSR-independent mechanisms. We combined in vitro and in vivo approaches to test possible GHSR-mediated biological activity of dAG. Both AG (100 nmol/L) and dAG (100 nmol/L) significantly increased inositol triphosphate formation in human embryonic kidney-293 cells transfected with human GHSR. As expected, intracerebroventricular infusion of AG in mice increased fat mass (FM), in comparison with the saline-infused controls. Intracerebroventricular dAG also increased FM at the highest dose tested (5 nmol/day). Chronic intracerebroventricular infusion of AG or dAG increased glucose-stimulated insulin secretion (GSIS). Subcutaneously infused AG regulated FM and GSIS in comparison with saline-infused control mice, whereas dAG failed to regulate these parameters even with doses that were efficacious when delivered intracerebroventricularly. Furthermore, intracerebroventricular dAG failed to regulate FM and induce hyperinsulinemia in GHSR-deficient (Ghsr(-/-)) mice. In addition, a hyperinsulinemic-euglycemic clamp suggests that intracerebroventricular dAG impairs glucose clearance without affecting endogenous glucose production. Together, these data demonstrate that dAG is an agonist of GHSR and regulates body adiposity and peripheral glucose metabolism through a CNS GHSR-dependent mechanism.

CYCLICAL SUBNORMAL SEPARATION IN A-GROUPS

African Journals Online (AJOL)

Then the fieldhn-=-Ihk contains a primitive I.!~ root of unity say .... Proof: We first denote the group algebra kG by W, viewed as a right module. ... Since the characteristic polynomial of x on V3 is the same as that of x on r , it is enough t q show ...

The quorum-quenching N-acyl homoserine lactone acylase PvdQ is an Ntn-hydrolase with an unusual substrate-binding pocket

NARCIS (Netherlands)

Bokhove, Marcel; Jimenez, Pol Nadal; Quax, Wim J.; Dijkstra, Bauke W.

2010-01-01

In many Gram-negative pathogens, their virulent behavior is regulated by quorum sensing, in which diffusible signals such as N-acyl homoserine lactones (AHLs) act as chemical messaging compounds. Enzymatic degradation of these diffusible signals by, e. g., lactonases or amidohydrolases abolishes AHL

Polystyrene Supported Al(OTf)3: an Environmentally Friendly Heterogeneous Catalyst for Friedel-Crafts Acylation of Aromatic Compounds

International Nuclear Information System (INIS)

Boroujeni, Kaveh Parvanak

2010-01-01

Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-Al(OTf) 3 ), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane

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.

A Historical Cohort Study on the Efficacy of Glucocorticoids and Riboflavin Among Patients with Late-onset Multiple Acyl-CoA Dehydrogenase Deficiency.

Science.gov (United States)

Liu, Xin-Yi; Wang, Zhi-Qiang; Wang, Dan-Ni; Lin, Min-Ting; Wang, Ning

2016-01-20

Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is the most common type of lipid storage myopathies in China. Most patients with late-onset MADD are well responsive to riboflavin. Up to now, these patients are often treated with glucocorticoids as the first-line drug because they are misdiagnosed as polymyositis without muscle biopsy or gene analysis. Although glucocorticoids seem to improve the fatty acid metabolism of late-onset MADD, the objective evaluation of their rationalization on this disorder and comparison with riboflavin treatment are unknown. We performed a historical cohort study on the efficacy of the two drugs among 45 patients with late-onset MADD, who were divided into glucocorticoids group and riboflavin group. Detailed clinical information of baseline and 1-month follow-up were collected. After 1-month treatment, a dramatic improvement of muscle strength was found in riboflavin group (P riboflavin group (P riboflavin group still presented high-level muscle enzymes and weak muscle strength after 1-month riboflavin treatment, meaning that 1-month treatment duration maybe insufficient and patients should keep on riboflavin supplement for a longer time. Our results provide credible evidences that the overall efficacy of riboflavin is superior to glucocorticoids, and a longer duration of riboflavin treatment is necessary for patients with late-onset MADD.

New series of Tc-99m-labeled hepatobiliary tracers: N'-acyl- and N'-sulfonyl ethylenediamine-N,N-diacetic acids

International Nuclear Information System (INIS)

Karube, Y.; Kono, A.; Maeda, T.; Ohya, M.; Matsushima, Y.

1981-01-01

Various Tc-99m-labeled N'-substituted derivatives of ethylenediamine-N,N-diacetic acid (EDDA) are evaluated as hepatobiliary imaging agents. N'-substituted aromatic acyl and aromatic sulfonyl derivatives of EDDA, labeled with Tc-99m, were administered to rabbits and golden hamsters, and the distribution indicated clearance by the hepatobiliary system. N'-aromatic sulfonyl EDDAs were labeled with Tc-99m by the SnCl 2 method with more than 99% yield. Clearance of Tc-99m-p-toluenesulfonyl EDDA from the blood and the liver was as rapid as that of Tc-99m N-(2,6-diethylphenylcarbamoylmethyl)iminodiacetic acid (Tc-99m diethyl IDA). Substitution of a bulky group at the aromatic ring in Tc-99m benzene-sulfonyl EDDA lowered urinary excretion. It is concluded that the sulfonyl EDDAs provide a fruitful source for Tc-99m-labeled hepatobiliary radiopharmaceuticals

Dihydropyranone Formation by Ipso C–H Activation in a Glucal 3-Carbamate-Derived Rhodium Acyl Nitrenoid

Science.gov (United States)

Hurlocker, Brisa; Abascal, Nadia C.; Repka, Lindsay M.; Santizo-Deleon, Elsy; Smenton, Abigail L.; Baranov, Victoria; Gupta, Ritu; Bernard, Sarah E.; Chowdhury, Shenjuti; Rojas, Christian M.

2011-01-01

By using (N-tosyloxy)-3-O-carbamoyl-D-glucal 10, which removes the need for a hypervalent iodine(III) oxidant, we provide evidence for rhodium nitrenoid-mediated ipso C–H activation as the origin of a C3-oxidized dihydropyranone product 3. This system may be especially susceptible to such a pathway due to the ease of forming a cation upon hydride transfer to the rhodium-complexed acyl nitrene. PMID:21381715

A Novel Glucosylation Reaction on Anthocyanins Catalyzed by Acyl-Glucose–Dependent Glucosyltransferase in the Petals of Carnation and Delphinium[C][W

Science.gov (United States)

Matsuba, Yuki; Sasaki, Nobuhiro; Tera, Masayuki; Okamura, Masachika; Abe, Yutaka; Okamoto, Emi; Nakamura, Haruka; Funabashi, Hisakage; Takatsu, Makoto; Saito, Mikako; Matsuoka, Hideaki; Nagasawa, Kazuo; Ozeki, Yoshihiro

2010-01-01

Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose–dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose–dependent glucosyltransferases. PMID:20971893

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.

Flavin Adenine Dinucleotide Status and the Effects of High-Dose Riboflavin Treatment in Short-Chain Acyl-CoA Dehydrogenase Deficiency

NARCIS (Netherlands)

van Maldegem, Bianca T.; Duran, Marinus; Wanders, Ronald J. A.; Waterham, Hans R.; Wijburg, Frits A.

2010-01-01

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an inborn error, biochemically characterized by increased plasma butyrylcarnitine (C4-C) concentration and increased ethylmalonic acid (EMA) excretion and caused by rare mutations and/or common gene variants in the SCAD encoding gene. Although

Myopathy in very-long-chain acyl-CoA dehydrogenase deficiency

DEFF Research Database (Denmark)

Scholte, H R; Van Coster, R N; de Jonge, P C

1999-01-01

was deficient in muscle and fibroblasts, consistent with deficiency of very-long-chain acyl-CoA dehydrogenase (VLCAD). The gene of this enzyme had a homozygous deletion of three base pairs in exon 9, skipping lysine residue 238. Fibroblasts oxidised myristate, palmitate and oleate at a rate of 129, 62 and 38......A 30-year-old man suffered since the age of 13 years from exercise induced episodes of intense generalised muscle pain, weakness and myoglobinuria. Fasting ketogenesis was low, while blood glucose remained normal. Muscle mitochondria failed to oxidise palmitoylcarnitine. Palmitoyl-CoA dehydrogenase......% of controls. In contrast to patients with cardiac VLCAD deficiency, our patient had no lipid storage, a normal heart function, a higher rate of oleate oxidation in fibroblasts and normal free carnitine in plasma and fibroblasts. 31P-nuclear magnetic resonance spectroscopy of muscle showed a normal oxidative...

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....... A series of azide- and alkyne-containing homoserine lactone building blocks was used to prepare an expanded set of 123 homoserine lactone analogues through a combination of solution- and solid-phase synthesis methods. The resulting compounds were subjected to cell-based quorum sensing screening assays...

Production of acylated homoserine lactones by psychrotrophic members of the Enterobacteriaceae isolated from foods

DEFF Research Database (Denmark)

Gram, Lone; Christensen, A.B.; Flodgaard, Lars

1999-01-01

Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules. These signals play important roles in several pathogenic and symbiotic bacteria. The following study was undertaken to investigate whether AHLs...... indicated that N-3-oxohexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat. AHL-positive strains cultured at 5 degrees C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 10(6) CFU/ml. AHLs were...

Formation of N-acyl-phosphatidylethanolamine and N-acylethanolamine (including anandamide) during glutamate-induced neurotoxicity

DEFF Research Database (Denmark)

Hansen, Harald S.; Moesgaard, B.; Hansen, H.H.

1999-01-01

N-acyl-phosphatidylethanolamine (NAPE) is present in very small amounts in mammalian tissues (less than 0.1% of total phospholipids). However, NAPE as well as its degradation production, N-acylethanolamine (NAE), can be formed in certain neuronal tissues in response to increased [Ca ](i). A high...... activation of the N-methyl-D-aspartate-receptor. Both NAPE and, to a lesser extent, NAE accumulate in a linear fashion for many hours while at the same time the neurons are dying. Likewise, in neurons prelabeled with C-arachidonic acid, C-arachidonic acid-labeled NAPE, and anandamide (= N...

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

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong-Ho; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Kwang-Pill E-mail: kplee@kyungpook.ac.kr

2001-07-01

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 {approx}132 deg. C and no more than about 40% of a second polypropylene having a lower melting temperature at {approx}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)

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

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong-Ho; Park, Keung-Shik; Kang, Hae-Jeong; Ryu, Eun-Nyoung; Lee, Pill-Kwang [Department of Chemistry Graduate School, Kyungpook National University, Taegu (Korea)

2000-07-01

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 {approx}132degC and no more than about 40% of a second polypropylene having a lower melting temperature at {approx}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)

An evaluation of the Parents Plus-Parenting When Separated programme.

Science.gov (United States)

Keating, Adele; Sharry, John; Murphy, Michelle; Rooney, Brendan; Carr, Alan

2016-04-01

This study evaluated the Parents Plus-Parenting when Separated Programme, an intervention specifically designed to address the needs of separated parents in an Irish context. In a randomized control trial, 82 separated parents with young children were assigned to the Parents Plus-Parenting when Separated Programme treatment group and 79 to a waiting-list control group. They were assessed on measures of client goals, parenting satisfaction, child and parental adjustment and interparental conflict at baseline (Time 1) and 6 weeks later (Time 2), after the treatment group completed the Parents Plus-Parenting when Separated Programme. From Time 1 to 2, significant goal attainment, increases in parenting satisfaction and decreases in child behaviour problems, parental adjustment problems and interparental conflict occurred in the Parents Plus-Parenting when Separated Programme group, but not in the control group. These results supported the effectiveness of Parents Plus-Parenting when Separated Programme, which should be made more widely available to separated parents. © The Author(s) 2015.

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.

The acute effects of intermittent treadmill running on hunger and plasma acylated ghrelin concentration in individuals with obesity

Directory of Open Access Journals (Sweden)

Gholipour M

2011-05-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Body weight is regulated by both food intake and energy expenditure. Ghrelin, a hormone produced by the stomach and pancreas, enhances appetite. This study was undertaken to determine the effects of intermittent treadmill running on acylated ghrelin and appetite in individuals with obesity."n"nMethods : Nine inactive male students, with a mean age of 20.56±0.48 yrs, a body mass index of 32.68±0.84 kg/m2 and a maximum oxygen uptake of 34.21±1.48 ml/kg/min, participated in the study in two trials (control and exercise in a counterbalanced, randomized design. The protocol included intermittent running with a constant intensity at 65% of VO2 max on a treadmill. Blood samples were collected before, during, and 2h after cessation of the exercise."n"nResults : Acylated ghrelin concentrations and hunger ratings decreased significantly in the second phase and remained lower than baseline (P=0.006 and P=0.002, respectively at the end of the exercise. The total area under the curve values and hunger ratings (all P<0.0005 were significantly lower in the exercise trial compared with the control state. Similarly, growth hormone rose significantly at the second phase and remained higher than baseline (P=0.033 at the

Simultaneous determination of platinum group elements and rhenium in rock samples using isotope dilution inductively coupled plasma mass spectrometry after cation exchange separation followed by solvent extraction

International Nuclear Information System (INIS)

Shinotsuka, Kazunori; Suzuki, Katsuhiko

2007-01-01

A simple and precise determination method for platinum group elements (PGEs) and Re in rock samples was developed using isotope dilution coupled with inductively coupled plasma mass spectrometry (ID-ICP-MS). Cation exchange separation was employed for simplicity, because it is applicable to group separation and simultaneous isotopic measurement in contrast with the widely used anion exchange separation which entails separate elution. However, its application to ID-ICP-MS has been limited due to spectral interferences from impurities retained in the PGE fraction even after ion chromatography. To overcome this limitation, solvent extraction using N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform was successfully applied for further purification. After the examination of optimum experimental parameters in cation exchange separation and solvent extraction using synthetic PGE solution, the established procedure was applied to the determination of PGEs and Re in some geochemical reference materials. The obtained results agreed well with the literature data determined using the different digestion methods (NiS fire assay and the use of a high-pressure asher) within the analytical uncertainties of each other. Significant difference in reproducibility between Ru, Ir, Pt and Os group, and Pd and Re group was observed in the results for BHVO-2 and JA-2. By considering the error factors affecting analytical reproducibility, we concluded that the difference is ascribed to the sample heterogeneity of minor minerals enriched in Ru, Ir, Pt and Os

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....

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....

UWIS isotope separator

Energy Technology Data Exchange (ETDEWEB)

Wojtasiewicz, A. [Warsaw Univ., Inst. of Experimental Physics, Nuclear Physics Div., Warsaw (Poland)

1997-12-31

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 figs, 10 refs.

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)

Separation of gases

International Nuclear Information System (INIS)

Wang, C.G.

1980-01-01

A process for separating gaseous mixtures of molecules of different mass comprises the steps of: causing a rotational nozzle to eject a contiguous plurality of successive groups of molecules into an evacuated space, the groups mutually overlapping to form a continuous stream of the mixture in the form of an Archimedean spiral, allowing the molecules of each group of molecules to move in accordance with their thermal velocities for a predetermined period of time following ejection, thereby to allow each group of molecules to form a generally spherical configuration the outer portion of which will be enriched, in molecules of lighter mass, relative to the inner portion thereof, using a deflector means co-rotating with the rotating nozzle to deflect molecules, which have been allowed to move for the predetermined period of time in accordance with their thermal velocities, from at least one desired portion of the stream and using a stationary collector means to collect the deflected molecules. The process is described with reference to the separation of isotopes of uranium hexafluoride. (author)

Investigations for chromatographic separation and determination of the rare earths and auxiliary group elements

International Nuclear Information System (INIS)

Post, K.

1981-01-01

Different method have been developed to quantitatively determine rare earth elements after their column chromatographic separation. The influence of the active solvents in the running systems diethyl ether/tetra hydrofuran (THF)/nitric acid (HNO 3 ) and diethyl ether/bis-(2-ethyl hexyl) phosphate (HDEHP)/HNO 3 was investigated on the column chromatographic separation of all rare earth elements is possible by the synergistic combination of the active running components THF and HDEHP. Further from product isotopes could also be separated using the running agents described here in investigations to separate fission product mixtures of irradiated uranium. (orig./HBR) [de

Phosphatidylserine-stimulated production of N-acyl-phosphatidylethanolamines by Ca2+-dependent N-acyltransferase.

Science.gov (United States)

Hussain, Zahir; Uyama, Toru; Kawai, Katsuhisa; Binte Mustafiz, Smriti Sultana; Tsuboi, Kazuhito; Araki, Nobukazu; Ueda, Natsuo

2018-05-01

N-acyl-phosphatidylethanolamine (NAPE) is known to be a precursor for various bioactive N-acylethanolamines including the endocannabinoid anandamide. NAPE is produced in mammals through the transfer of an acyl chain from certain glycerophospholipids to phosphatidylethanolamine (PE) by Ca 2+ -dependent or -independent N-acyltransferases. The ε isoform of mouse cytosolic phospholipase A 2 (cPLA 2 ε) was recently identified as a Ca 2+ -dependent N-acyltransferase (Ca-NAT). In the present study, we first showed that two isoforms of human cPLA 2 ε function as Ca-NAT. We next purified both mouse recombinant cPLA 2 ε and its two human orthologues to examine their catalytic properties. The enzyme absolutely required Ca 2+ for its activity and the activity was enhanced by phosphatidylserine (PS). PS enhanced the activity 25-fold in the presence of 1 mM CaCl 2 and lowered the EC 50 value of Ca 2+ >8-fold. Using a PS probe, we showed that cPLA 2 ε largely co-localizes with PS in plasma membrane and organelles involved in the endocytic pathway, further supporting the interaction of cPLA 2 ε with PS in living cells. Finally, we found that the Ca 2+ -ionophore ionomycin increased [ 14 C]NAPE levels >10-fold in [ 14 C]ethanolamine-labeled cPLA 2 ε-expressing cells while phospholipase A/acyltransferase-1, acting as a Ca 2+ -independent N-acyltransferase, was insensitive to ionomycin for full activity. In conclusion, PS potently stimulated the Ca 2+ -dependent activity and human cPLA 2 ε isoforms also functioned as Ca-NAT. Copyright © 2018 Elsevier B.V. All rights reserved.

Mass Spectrometric Characterization of Circulating Covalent Protein Adducts Derived from a Drug Acyl Glucuronide Metabolite: Multiple Albumin Adductions in Diclofenac Patients

Science.gov (United States)

Hammond, Thomas G.; Meng, Xiaoli; Jenkins, Rosalind E.; Maggs, James L.; Castelazo, Anahi Santoyo; Regan, Sophie L.; Bennett, Stuart N. L.; Earnshaw, Caroline J.; Aithal, Guruprasad P.; Pande, Ira; Kenna, J. Gerry; Stachulski, Andrew V.; Park, B. Kevin

2014-01-01

Covalent protein modifications by electrophilic acyl glucuronide (AG) metabolites are hypothetical causes of hypersensitivity reactions associated with certain carboxylate drugs. The complex rearrangements and reactivities of drug AG have been defined in great detail, and protein adducts of carboxylate drugs, such as diclofenac, have been found in liver and plasma of experimental animals and humans. However, in the absence of definitive molecular characterization, and specifically, identification of signature glycation conjugates retaining the glucuronyl and carboxyl residues, it cannot be assumed any of these adducts is derived uniquely or even fractionally from AG metabolites. We have therefore undertaken targeted mass spectrometric analyses of human serum albumin (HSA) isolated from diclofenac patients to characterize drug-derived structures and, thereby, for the first time, have deconstructed conclusively the pathways of adduct formation from a drug AG and its isomeric rearrangement products in vivo. These analyses were informed by a thorough understanding of the reactions of HSA with diclofenac AG in vitro. HSA from six patients without drug-related hypersensitivities had either a single drug-derived adduct or one of five combinations of 2–8 adducts from among seven diclofenac N-acylations and three AG glycations on seven of the protein’s 59 lysines. Only acylations were found in every patient. We present evidence that HSA modifications by diclofenac in vivo are complicated and variable, that at least a fraction of these modifications are derived from the drug’s AG metabolite, and that albumin adduction is not inevitably a causation of hypersensitivity to carboxylate drugs or a coincidental association. PMID:24902585

Biosynthesis of Corynecins by Corynebacterium hydrocarboclastus. On the origin of the N-acyl group

Energy Technology Data Exchange (ETDEWEB)

Nakano, H; Tomita, F; Suzuki, T [Kyowa Hakko Kogyo Co. Ltd., Tokyo (Japan)

1976-02-01

1) The addition of amino acids, such as threonine, homoserine and methionine, to producing cultures resulted in an increase of the production of Corynecin 2. ..cap alpha..-Ketobutyric acid showed the similar effect. 2) The incorporation of these amino acids and the ketoacid into the propionyl group of Corynecin 2 was confirmed by the feeding experiments with labeled compounds, whereas propionic acid-U/sup 14/C was incorporated poorly into Corynecins with a relatively high degree of randomization of radioactivities. 3) L-Valine-U/sup 14/C was incorporated into Corynecin 3, suggesting that the isobutyryl group of Corynecin 3 was derived from L-valine via ..cap alpha..-ketoisovalerate. 4) The origin of the acetyl group of Corynecin I was discussed on the basis of the incorporation experiments with acetate, pyruvate and L-alanine, all labeled with /sup 14/C.

Rapid Identification of unstable acyl glucoside flavonoids of Oxytropis racemosa Turcz by high-performance liquid chromatography-diode array detection-electrospray ionisation/multi-stage mass spectrometry.

Science.gov (United States)

Song, Shuang; Zheng, Xiu-Ping; Liu, Wei-Dong; Du, Rui-Fang; Feng, Zi-Ming; Zhang, Pei-Cheng; Bi, Li-Fu

2013-02-01

Oxytropis racemosa Turcz is an important minority medicine that is used mainly to improve children's indigestion, especially in inner Mongolia and Tibet. Previous studies indicated that the characteristic constituents of this plant are acylated flavonoids. Rapidly identify the characteristic chemical constituents of O. racemosa by high-performance liquid chromatography-diode array detection-electrospray ionisation/multi-stage mass spectrometry (HPLC-DAD-ESI/MS(n) ) and suggest a useful method to control the quality of this medicinal plant. In the HPLC fingerprint, 32 flavonoids were tentatively identified by a detailed analysis of their mass spectra, UV spectra and retention times. Furthermore, 13 flavonoids were confirmed by comparison with previously isolated compounds obtained from O. racemosa. In total, 32 flavonoids, including 13 flavonoids with 3-hydroxy-3-methylglutaric acid (HMG) moieties and four flavonoids with 3-malonyl moieties, were identified in the extract of O. racemosa. Among the compounds identified, 10 were characterised as new compounds for their particular acylated sugar moieties. The method described is effective for obtaining a comprehensive phytochemical profile of plants containing unstable acylated flavonoids. The method is also useful for constructing the chromatographic fingerprint of the minority medicine -O. racemosa Turcz for quality control. Copyright © 2012 John Wiley & Sons, Ltd.

Properties influencing cracking and separation of palm nuts in a mechanical cracker cum separator

Directory of Open Access Journals (Sweden)

JOSHUA OLANREWAJU OLAOYE

2018-01-01

Full Text Available Experimental studies of some properties influencing cracking and separation of palm kernel from the shell was conducted in a palm kernel dual processing machine. A mechanical cracking cum separating machine was developed for the study. The cracking unit consists of feed hopper, impeller shaft, cracking drum and impeller blade. The nut falls by gravity through the hopper channel into the cracking drum where the cracking process takes place through the help of impeller blades that flip the palm nut against the walls of cylindrical cracking drum. The mass of cracked nut flows through the separating unit that separates the kernel from the shell. The separation is induced by high current of air mass generated by an axial fan. A dura palm variety was selected and a total sample of eighteen thousand (18000 palm nuts were obtained and divided into two groups (feed rates, A and B, of eight thousand and ten thousand palm nuts respectively. Sample groups A and B were further divided into five sub – groups of four hundred (400 and five hundred (500 palm kernel nuts. Each sub group (feed rate was replicated four times at different shaft speeds (600, 900, 1200, 1500 and 1800 rpm. Results showed that cracking efficiencies increased with respect to speed. Un-cracked nuts percentage ranged from 1.3 to 5.3% at 7.1% moisture content, and 1.6 to 4.5% for 400 and 500 feed rates, respectively. Cracking time for both feed rates decreased with shaft speed. Throughput capacity of 11.49 kg/h was observed to be the lowest at 600 rpm and moisture content of 7.1% for both 400 feed rates and the highest throughput capacity of 37.16 kg/h was recorded at 1800 rpm at moisture contents of 9.3% and 16.1%. The results of this study shows that moisture content, engine speed and feed rate are significant parameters that influence cracking of nuts and separation of palm kernel from the shell.

Presence, formation and putative biological activities of N-acyl serotonins, a novel class of fatty-acid derived mediators in the intestinal tract

NARCIS (Netherlands)

Verhoeckx, K.C.M.; Voortman, T.; Balvers, M.G.J.; Hendriks, H.F.J.; Wortelboer, H.M.; Witkamp, R.F.

2011-01-01

Following the discovery of the endocannabinoid arachidonoyl ethanolamide (anandamide) and other N-acyl-ethanolamines, several other compounds have been found in which amino acids or neurotransmitters rather than ethanolamide are linked to fatty acids. Studies have shown that the local availability

Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT, a key enzyme in neutral lipid biosynthesis

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Margis-Pinheiro Marcia

2011-09-01

Full Text Available Abstract Background Triacylglycerides (TAGs are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20 is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin. Results We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events. Conclusions In this study, we identified several DGAT1 and DGAT2

Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis.

Science.gov (United States)

Turchetto-Zolet, Andreia C; Maraschin, Felipe S; de Morais, Guilherme L; Cagliari, Alexandro; Andrade, Cláudia M B; Margis-Pinheiro, Marcia; Margis, Rogerio

2011-09-20

Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin. We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events. In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa. Overall, the data show that

Effect of doxorubicin on the order and dynamics of the acyl chains of anionic and zwitterionic phospholipids in liquid-crystalline mixed model membranes

NARCIS (Netherlands)

Wolf, de F.A.; Nicolaij, K.; Kruijff, de B.

1992-01-01

We investigated the effect of the antineoplastic drug doxorubicin on the order of the acyl chains in liquid-crystalline mixed bilayers consisting of dioleoylphosphatidylserine (DOPS) or -phosphatidic acid (DOPA), and dioleoylphosphatidylcholine (DOPC) or - hosphatidylethanolamine (DOPE). Previous

A new, simple assay for long-chain acyl-CoA dehydrogenase in cultured skin fibroblasts using stable isotopes and GC-MS

NARCIS (Netherlands)

Niezen-Koning, K. E.; Wanders, R. J.; Nagel, G. T.; IJlst, L.; Heymans, H. S.

1992-01-01

In this paper, we present a new method for measurement of long-chain acyl-CoA dehydrogenase (LCAD) activities in cultured skin fibroblasts. The method is based upon gas chromatographic/mass spectrometric determination of 3-OH-hexadecanoic acid formed during incubation of fibroblasts in a medium

Glycosphingolipids: 2H NMR study of the influence of carbohydrate headgroup structure on ceramide acyl chain behavior in glycolipid-phospholipid bilayers

International Nuclear Information System (INIS)

Fenske, D.B.; Jarrell, H.C.; Hamilton, K.; Florio, E.; Barber, K.R.; Grant, C.W.M.

1991-01-01

Galactosyl- and glucosylceramide, globoside, and dihydrolactosylceramide, bearing [2,2- 2 H 2 ]stearic acid, have been studied at a concentration of 10 mol % in bilayers of dimyristoylphosphatidylcholine by 2 H NMR. The quadrupolar splittings Δv Q of the C2 deuterons were measured at several temperatures in the range of 30-60 degree C. Spin-lattice relaxation times T 1 of C2 deuterons were determined in the same temperature range for all lipids but globoside. T 1 values for the GlcCer and GalCer systems increased with temperature, indicating that the motions responsible for relaxation were in the short correlation time regime. T 1 for deuterons at the acyl chain C2-position of LaCer was observed to decrease with increasing temperature, indicating that the motion(s) dominating relaxation are in the long correlation time regime. Thus the mobility of the acyl chain at the 2-position is reduced in the LacCer with respect to GlcCer and GalCer

Cardiovascular and metabolic risk profile and acylation-stimulating protein levels in children with Prader-Willi syndrome and effects of growth hormone treatment

NARCIS (Netherlands)

R.F.A. de Lind van Wijngaarden (Roderick); K. Cianflone (Katherine); Y. Gao; R.W.J. Leunissen (Ralph); A.C.S. Hokken-Koelega (Anita)

2010-01-01

textabstractContext: Reports on the cardiovascular and metabolic risk profile in children with Prader-Willi syndrome (PWS) and the effects of GH treatment are scarce. Acylation-stimulating protein (ASP) stimulates glucose uptake and triglyceride storage in adipose tissue. Objectives: The aim was to

Cost-effectiveness analysis of universal newborn screening for medium chain acyl-CoA dehydrogenase deficiency in France

OpenAIRE

Hamers, Françoise F; Rumeau-Pichon, Catherine

2012-01-01

Abstract Background Five diseases are currently screened on dried blood spots in France through the national newborn screening programme. Tandem mass spectrometry (MS/MS) is a technology that is increasingly used to screen newborns for an increasing number of hereditary metabolic diseases. Medium chain acyl-CoA dehydrogenase deficiency (MCADD) is among these diseases. We sought to evaluate the cost-effectiveness of introducing MCADD screening in France. Methods We developed a decision model t...

Human carbonyl reductase 1 participating in intestinal first-pass drug metabolism is inhibited by fatty acids and acyl-CoAs.

Science.gov (United States)

Hara, Akira; Endo, Satoshi; Matsunaga, Toshiyuki; El-Kabbani, Ossama; Miura, Takeshi; Nishinaka, Toru; Terada, Tomoyuki

2017-08-15

Human carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, reduces a variety of carbonyl compounds including endogenous isatin, prostaglandin E 2 and 4-oxo-2-nonenal. It is also a major non-cytochrome P450 enzyme in the phase I metabolism of carbonyl-containing drugs, and is highly expressed in the intestine. In this study, we found that long-chain fatty acids and their CoA ester derivatives inhibit CBR1. Among saturated fatty acids, myristic, palmitic and stearic acids were inhibitory, and stearic acid was the most potent (IC 50 9µM). Unsaturated fatty acids (oleic, elaidic, γ-linolenic and docosahexaenoic acids) and acyl-CoAs (palmitoyl-, stearoyl- and oleoyl-CoAs) were more potent inhibitors (IC 50 1.0-2.5µM), and showed high inhibitory selectivity to CBR1 over its isozyme CBR3 and other SDR superfamily enzymes (DCXR and DHRS4) with CBR activity. The inhibition by these fatty acids and acyl-CoAs was competitive with respect to the substrate, showing the K i values of 0.49-1.2µM. Site-directed mutagenesis of the substrate-binding residues of CBR1 suggested that the interactions between the fatty acyl chain and the enzyme's Met141 and Trp229 are important for the inhibitory selectivity. We also examined CBR1 inhibition by oleic acid in cellular levels: The fatty acid effectively inhibited CBR1-mediated 4-oxo-2-nonenal metabolism in colon cancer DLD1 cells and increased sensitivity to doxorubicin in the drug-resistant gastric cancer MKN45 cells that highly express CBR1. The results suggest a possible new food-drug interaction through inhibition of CBR1-mediated intestinal first-pass drug metabolism by dietary fatty acids. Copyright © 2017 Elsevier Inc. All rights reserved.

Structural insights into GDP-mediated regulation of a bacterial acyl-CoA thioesterase.

Science.gov (United States)

Khandokar, Yogesh B; Srivastava, Parul; Cowieson, Nathan; Sarker, Subir; Aragao, David; Das, Shubagata; Smith, Kate M; Raidal, Shane R; Forwood, Jade K

2017-12-15

Thioesterases catalyze the cleavage of thioester bonds within many activated fatty acids and acyl-CoA substrates. They are expressed ubiquitously in both prokaryotes and eukaryotes and are subdivided into 25 thioesterase families according to their catalytic active site, protein oligomerization, and substrate specificity. Although many of these enzyme families are well-characterized in terms of function and substrate specificity, regulation across most thioesterase families is poorly understood. Here, we characterized a TE6 thioesterase from the bacterium Neisseria meningitidis Structural analysis with X-ray crystallographic diffraction data to 2.0-Å revealed that each protein subunit harbors a hot dog-fold and that the TE6 enzyme forms a hexamer with D3 symmetry. An assessment of thioesterase activity against a range of acyl-CoA substrates revealed the greatest activity against acetyl-CoA, and structure-guided mutagenesis of putative active site residues identified Asn 24 and Asp 39 as being essential for activity. Our structural analysis revealed that six GDP nucleotides bound the enzyme in close proximity to an intersubunit disulfide bond interactions that covalently link thioesterase domains in a double hot dog dimer. Structure-guided mutagenesis of residues within the GDP-binding pocket identified Arg 93 as playing a key role in the nucleotide interaction and revealed that GDP is required for activity. All mutations were confirmed to be specific and not to have resulted from structural perturbations by X-ray crystallography. This is the first report of a bacterial GDP-regulated thioesterase and of covalent linkage of thioesterase domains through a disulfide bond, revealing structural similarities with ADP regulation in the human ACOT12 thioesterase. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Synthesis of Acylated Xylan-Based Magnetic Fe3O4 Hydrogels and Their Application for H2O2 Detection

Directory of Open Access Journals (Sweden)

Qing-Qing Dai

2016-08-01

Full Text Available Acylated xylan-based magnetic Fe3O4 nanocomposite hydrogels (ACX-MNP-gels were prepared by fabricating Fe3O4 nanoctahedra in situ within a hydrogel matrix which was synthesized by the copolymerization of acylated xylan (ACX with acrylamide and N-isopropylacrylamide under ultraviolet irradiation. The size of the Fe3O4 fabricated within the hydrogel matrix could be adjusted through controlling the crosslinking concentrations (C. The magnetic hydrogels showed desirable magnetic and mechanical properties, which were confirmed by XRD, Raman spectroscopy, physical property measurement system, SEM, TGA, and compression test. Moreover, the catalytic performance of the magnetic hydrogels was explored. The magnetic hydrogels (C = 7.5 wt % presented excellent catalytic activity and provided a sensitive response to H2O2 detection even at a concentration level of 5 × 10−6 mol·L−1. This approach to preparing magnetic hydrogels loaded with Fe3O4 nanoparticles endows xylan-based hydrogels with new promising applications in biotechnology and environmental chemistry.

Acyl CoA Binding Domain Containing 3 (ACBD3) Protein in Huntington’s Disease 
Human Skin Fibroblasts

Czech Academy of Sciences Publication Activity Database

Kratochvílová, H.; Rodinová, M.; Sládková, J.; Klempíř, J.; Lišková, Irena; Motlík, Jan; Zeman, J.; Hansíková, H.; Tesařová, M.

2015-01-01

Roč. 78, Suppl. 2 (2015), s. 34-38 ISSN 1210-7859. [Conference on Animal Models for neurodegenerative Diseases /3./. Liblice, 08.11.2015-10.11.2015] R&D Projects: GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 Keywords : Huntington’s disease * Acyl-CoA binding domain containing 3 protein * human skin fibroblasts Subject RIV: FH - Neurology Impact factor: 0.209, year: 2015

Depletion of Acyl-Coenzyme A-Binding Protein Affects Sphingolipid Synthesis and Causes Vesicle Accumulation and Membrane Defects in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Gaigg, B; Neergaard, T B; Schneiter, R

2001-01-01

Deletion of the yeast gene ACB1 encoding Acb1p, the yeast homologue of the acyl-CoA-binding protein (ACBP), resulted in a slower growing phenotype that adapted into a faster growing phenotype with a frequency >1:10(5). A conditional knockout strain (Y700pGAL1-ACB1) with the ACB1 gene under contro...

Isoforms of acyl carrier protein involved in seed-specific fatty acid synthesis.

Science.gov (United States)

Suh, M C; Schultz, D J; Ohlrogge, J B

1999-03-01

Seeds of coriandrum sativum (coriander) and Thunbergia alata (black-eyed Susan vine) produce unusual monoenoic fatty acids which constitute over 80% of the total fatty acids of the seed oil. The initial step in the formation of these fatty acids is the desaturation of palmitoyl-ACP (acyl carrier protein) at the delta(4) or delta(6) positions to produce delta(4)-hexadecenoic acid (16:1(delta(4)) or delta(6)-hexadecenoic acid (16:1(delta(6)), respectively. The involvement of specific forms of ACP in the production of these novel monoenoic fatty acids was studied. ACPs were partially purified from endosperm of coriander and T. alata and used to generate 3H- and 14C-labelled palmitoyl-ACP substrates. In competition assays with labelled palmitoyl-ACP prepared from spinach (Spinacia oleracea), delta(4)-acyl-ACP desaturase activity was two- to threefold higher with coriander ACP than with spinach ACP. Similarly, the T. alata delta(6) desaturase favoured T. alata ACP over spinach ACP. A cDNA clone, Cs-ACP-1, encoding ACP was isolated from a coriander endosperm cDNA library. Cs-ACP-1 mRNA was predominantly expressed in endosperm rather than leaves. The Cs-ACP-1 mature protein was expressed in E. coli and comigrated on SDS-PAGE with the most abundant ACP expressed in endosperm tissues. In in vitro delta(4)-palmitoyl-ACP desaturase assays, the Cs-ACP-1 expressed from E. coli was four- and 10-fold more active than spinach ACP or E. coli ACP, respectively, in the synthesis of delta(4)-hexadecenoic acid from palmitoyl-ACP. In contrast, delta(9)-stearoyl-ACP desaturase activity from coriander endosperm did not discriminate strongly between different ACP species. These results indicate that individual ACP isoforms are specifically involved in the biosynthesis of unusual seed fatty acids and further suggest that expression of multiple ACP isoforms may participate in determining the products of fatty acid biosynthesis.

Defective Pollen Wall 2 ( DPW2 ) Encodes an Acyl Transferase Required for Rice Pollen Development

Energy Technology Data Exchange (ETDEWEB)

Xu, Dawei [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Shi, Jianxin [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Rautengarten, Carsten [Univ. of Melbourne (Australia). ARC Centre of Excellence in Plant Cell Walls; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst. and Biological Systems and Engineering Division; Yang, Li [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Qian, Xiaoling [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Uzair, Muhammad [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Zhu, Lu [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Luo, Qian [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; An, Gynheung [Kyung Hee Univ., Yongin (Korea). Crop Biotech Inst.; Waßmann, Fritz [Univ. of Bonn (Germany). Inst. of Cellular and Molecular Botany; Schreiber, Lukas [Univ. of Bonn (Germany). Inst. of Cellular and Molecular Botany; Heazlewood, Joshua L. [Univ. of Melbourne (Australia). ARC Centre of Excellence in Plant Cell Walls; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst. and Biological Systems and Engineering Division; Scheller, Henrik Vibe [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst. and Biological Systems and Engineering Division; Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology; Hu, Jianping [Michigan State Univ., East Lansing, MI (United States). Dept. of Energy Plant Research Lab.; Zhang, Dabing [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences; Univ. of Adelaide, SA (Australia). School of Agriculture, Food and Wine; Liang, Wanqi [Shanghai Jiao Tong Univ. (China). Joint International Research Lab. of Metabolic and Developmental Sciences

2016-05-31

Aliphatic and aromatic lipids are both essential structural components of the plant cuticle, an important interface between the plant and environment. Although cross links between aromatic and aliphatic or other moieties are known to be associated with the formation of leaf cutin and root and seed suberin, the contribution of aromatic lipids to the biosynthesis of anther cuticles and pollen walls remains elusive. In this study, we characterized the rice (Oryza sativa) male sterile mutant, defective pollen wall 2 (dpw2), which showed an abnormal anther cuticle, a defective pollen wall, and complete male sterility. Compared with the wild type, dpw2 anthers have increased amounts of cutin and waxes and decreased levels of lipidic and phenolic compounds. DPW2 encodes a cytoplasmically localized BAHD acyltransferase. In vitro assays demonstrated that recombinant DPW2 specifically transfers hydroxycinnamic acid moieties, using v-hydroxy fatty acids as acyl acceptors and hydroxycinnamoyl-CoAs as acyl donors. Thus, The cytoplasmic hydroxycinnamoyl-CoA:v-hydroxy fatty acid transferase DPW2 plays a fundamental role in male reproduction via the biosynthesis of key components of the anther cuticle and pollen wall.

Separation of amaranthine-type betacyanins by ion-pair high-speed countercurrent chromatography.

Science.gov (United States)

Jerz, Gerold; Gebers, Nadine; Szot, Dominika; Szaleniec, Maciej; Winterhalter, Peter; Wybraniec, Slawomir

2014-05-30

Betacyanins, red-violet plant pigments, were fractionated by ion-pair high-speed countercurrent chromatography (IP-HSCCC) from leaves extract of Iresine lindenii Van Houtte, an ornamental plant of the family Amaranthaceae. An HSCCC solvent system consisting of TBME-1-BuOH-ACN-H2O (1:3:1:5, v/v/v/v) was applied using ion-pair forming heptafluorobutyric acid (HFBA). Significantly different elution profiles of betacyanin diastereomeric pairs (derivatives based on betanidin and isobetanidin) observed in the HSCCC in comparison to HPLC systems indicate a complementarity of both techniques' fractionation capabilities. The numerous diastereomeric pairs can be selectively separated from each other using the HSCCC system simplifying the pigment purification process. Apart from the three well known highly abundant pigments (amaranthine, betanin and iresinin I) together with their isoforms, three new acylated (feruloylated and sinapoylated) betacyanins as well as known pigment hylocerenin (previously isolated from cacti fruits) were characterized in the plant for the first time and they are new for the whole Amaranthaceae family. Copyright © 2014 Elsevier B.V. All rights reserved.

An Acylated Kaempferol Glycoside from Flowers of Foeniculum vulgare and F. Dulce

Directory of Open Access Journals (Sweden)

Shahera M. Ezzat

2002-02-01

Full Text Available 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-O-β-D-glucuronide (7. Structure elucidation of the above mentioned flavonoids was achieved by UV, 1H- and 13C-NMR, 1H-1H COSY, HMQC and EI-MS.

Mechanism of MenE inhibition by acyl-adenylate analogues and discovery of novel antibacterial agents.

Science.gov (United States)

Matarlo, Joe S; Evans, Christopher E; Sharma, Indrajeet; Lavaud, Lubens J; Ngo, Stephen C; Shek, Roger; Rajashankar, Kanagalaghatta R; French, Jarrod B; Tan, Derek S; Tonge, Peter J

2015-10-27

MenE is an o-succinylbenzoyl-CoA (OSB-CoA) synthetase in the bacterial menaquinone biosynthesis pathway and is a promising target for the development of novel antibacterial agents. The enzyme catalyzes CoA ligation via an acyl-adenylate intermediate, and we have previously reported tight-binding inhibitors of MenE based on stable acyl-sulfonyladenosine analogues of this intermediate, including OSB-AMS (1), which has an IC50 value of ≤25 nM for Escherichia coli MenE. Herein, we show that OSB-AMS reduces menaquinone levels in Staphylococcus aureus, consistent with its proposed mechanism of action, despite the observation that the antibacterial activity of OSB-AMS is ∼1000-fold lower than the IC50 for enzyme inhibition. To inform the synthesis of MenE inhibitors with improved antibacterial activity, we have undertaken a structure-activity relationship (SAR) study stimulated by the knowledge that OSB-AMS can adopt two isomeric forms in which the OSB side chain exists either as an open-chain keto acid or a cyclic lactol. These studies revealed that negatively charged analogues of the keto acid form bind, while neutral analogues do not, consistent with the hypothesis that the negatively charged keto acid form of OSB-AMS is the active isomer. X-ray crystallography and site-directed mutagenesis confirm the importance of a conserved arginine for binding the OSB carboxylate. Although most lactol isomers tested were inactive, a novel difluoroindanediol inhibitor (11) with improved antibacterial activity was discovered, providing a pathway toward the development of optimized MenE inhibitors in the future.

Genome mining reveals high incidence of putative lipopeptide biosynthesis NRPS/PKS clusters containing fatty acyl-AMP ligase genes inbiofilm-forming cyanobacteria

Czech Academy of Sciences Publication Activity Database

Galica, Tomáš; Hrouzek, P.; Mareš, Jan

2017-01-01

Roč. 53, č. 5 (2017), s. 985-998 ISSN 0022-3646 R&D Projects: GA ČR(CZ) GA16-09381S Institutional support: RVO:60077344 Keywords : cyanobacteria * fatty-acyl AMP ligase * genome mining * lipopeptides * microbial biofilm Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.608, year: 2016

A Historical Cohort Study on the Efficacy of Glucocorticoids and Riboflavin Among Patients with Late-onset Multiple Acyl-CoA Dehydrogenase Deficiency

Institute of Scientific and Technical Information of China (English)

Xin-Yi Liu; Zhi-Qiang Wang; Dan-Ni Wang; Min-Ting Lin; Ning Wang

2016-01-01

Background:Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is the most common type of lipid storage myopathies in China.Most patients with late-onset MADD are well responsive to riboflavin.Up to now,these patients are often treated with glucocorticoids as the first-line drug because they are misdiagnosed as polymyositis without muscle biopsy or gene analysis.Although glucocorticoids seem to improve the fatty acid metabolism of late-onset MADD,the objective evaluation of their rationalization on this disorder and comparison with riboflavin treatment are unknown.Methods:We performed a historical cohort study on the efficacy of the two drugs among 45 patients with late-onset MADD,who were divided into glucocorticoids group and riboflavin group.Detailed clinical information of baseline and 1-month follow-up were collected.Results:After 1-month treatment,a dramatic improvement of muscle strength was found in riboflavin group (P ＜ 0.05).There was no significant difference in muscle enzymes between the two groups.Significantly,the number of patients with full recovery in glucocorticoids group was less than the number in riboflavin group (P ＜ 0.05).On the other hand,almost half of the patients in riboflavin group still presented high-level muscle enzymes and weak muscle strength after 1-month riboflavin treatment,meaning that 1-month treatment duration maybe insufficient and patients should keep on riboflavin supplement for a longer time.Conclusions:Our results provide credible evidences that the overall efficacy of riboflavin is superior to glucocorticoids,and a longer duration of riboflavin treatment is necessary for patients with late-onset MADD.

An efficient and green method for regio- and chemo-selective Friedel–Crafts acylations using a deep eutectic mixture ([CholineCl][ZnCl2]3)

DEFF Research Database (Denmark)

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

2016-01-01

[CholineCl][ZnCl2]3, a deep eutectic solvent between choline chloride and ZnCl2, has been used as a dual function catalyst and green solvent for the Friedel–Crafts acylation of aromatic compounds instead of using the moisture-sensitive Lewis acids and volatile organic solvents. The reactions...... are performed with high yields under microwave irradiation with short reaction times for the synthesis of ketones. Interestingly, indole derivatives are regioselectively acylated in the 3-position under mild conditions with high yields without NH protection. Three new ketone products are synthesized. [Choline......Cl][ZnCl2]3 is easily synthesized from choline chloride and zinc chloride at a low cost, with easy purification and environmentally benign compounds. [CholineCl][ZnCl2]3 can be reused up to five times without loss of catalytic activity, making it ideal in industrial processes....

Structure of 3-ketoacyl-(acyl-carrier-protein) reductase from Rickettsia prowazekii at 2.25 Å resolution

International Nuclear Information System (INIS)

Subramanian, Sandhya; Abendroth, Jan; Phan, Isabelle Q. H.; Olsen, Christian; Staker, Bart L.; Napuli, A.; Van Voorhis, Wesley C.; Stacy, Robin; Myler, Peter J.

2011-01-01

The R. prowazekii 3-ketoacyl-(acyl-carrier-protein) reductase is similar to those from other prokaryotic pathogens but differs significantly from the mammalian orthologue, strengthening its case as a potential drug target. Rickettsia prowazekii, a parasitic Gram-negative bacterium, is in the second-highest biodefense category of pathogens of the National Institute of Allergy and Infectious Diseases, but only a handful of structures have been deposited in the PDB for this bacterium; to date, all of these have been solved by the SSGCID. Owing to its small genome (about 800 protein-coding genes), it relies on the host for many basic biosynthetic processes, hindering the identification of potential antipathogenic drug targets. However, like many bacteria and plants, its metabolism does depend upon the type II fatty-acid synthesis (FAS) pathway for lipogenesis, whereas the predominant form of fatty-acid biosynthesis in humans is via the type I pathway. Here, the structure of the third enzyme in the FAS pathway, 3-ketoacyl-(acyl-carrier-protein) reductase, is reported at a resolution of 2.25 Å. Its fold is highly similar to those of the existing structures from some well characterized pathogens, such as Mycobacterium tuberculosis and Burkholderia pseudomallei, but differs significantly from the analogous mammalian structure. Hence, drugs known to target the enzymes of pathogenic bacteria may serve as potential leads against Rickettsia, which is responsible for spotted fever and typhus and is found throughout the world

Medium-Chain Acyl-CoA Deficiency: Outlines from Newborn Screening, In Silico Predictions, and Molecular Studies

Directory of Open Access Journals (Sweden)

Serena Catarzi

2013-01-01

Full Text Available Medium-chain acyl-CoA dehydrogenase deficiency (MCADD is a disorder of fatty acid oxidation characterized by hypoglycemic crisis under fasting or during stress conditions, leading to lethargy, seizures, brain damage, or even death. Biochemical acylcarnitines data obtained through newborn screening by liquid chromatography-tandem mass spectrometry (LC-MS/MS were confirmed by molecular analysis of the medium-chain acyl-CoA dehydrogenase (ACADM gene. Out of 324.000 newborns screened, we identified 14 MCADD patients, in whom, by molecular analysis, we found a new nonsense c.823G>T (p.Gly275* and two new missense mutations: c.253G>C (p.Gly85Arg and c.356T>A (p.Val119Asp. Bioinformatics predictions based on both phylogenetic conservation and functional/structural software were used to characterize the new identified variants. Our findings confirm the rising incidence of MCADD whose existence is increasingly recognized due to the efficacy of an expanded newborn screening panel by LC-MS/MS making possible early specific therapies that can prevent possible crises in at-risk infants. We noticed that the “common” p.Lys329Glu mutation only accounted for 32% of the defective alleles, while, in clinically diagnosed patients, this mutation accounted for 90% of defective alleles. Unclassified variants (UVs or VUSs are especially critical when considering screening programs. The functional and pathogenic characterization of genetic variants presented here is required to predict their medical consequences in newborns.

Medium-Chain Acyl-CoA Deficiency: Outlines from Newborn Screening, In Silico Predictions, and Molecular Studies

Science.gov (United States)

Catarzi, Serena; Caciotti, Anna; Thusberg, Janita; Tonin, Rodolfo; Malvagia, Sabrina; la Marca, Giancarlo; Pasquini, Elisabetta; Cavicchi, Catia; Ferri, Lorenzo; Donati, Maria A.; Baronio, Federico; Guerrini, Renzo; Mooney, Sean D.; Morrone, Amelia

2013-01-01

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is a disorder of fatty acid oxidation characterized by hypoglycemic crisis under fasting or during stress conditions, leading to lethargy, seizures, brain damage, or even death. Biochemical acylcarnitines data obtained through newborn screening by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were confirmed by molecular analysis of the medium-chain acyl-CoA dehydrogenase (ACADM) gene. Out of 324.000 newborns screened, we identified 14 MCADD patients, in whom, by molecular analysis, we found a new nonsense c.823G>T (p.Gly275∗) and two new missense mutations: c.253G>C (p.Gly85Arg) and c.356T>A (p.Val119Asp). Bioinformatics predictions based on both phylogenetic conservation and functional/structural software were used to characterize the new identified variants. Our findings confirm the rising incidence of MCADD whose existence is increasingly recognized due to the efficacy of an expanded newborn screening panel by LC-MS/MS making possible early specific therapies that can prevent possible crises in at-risk infants. We noticed that the “common” p.Lys329Glu mutation only accounted for 32% of the defective alleles, while, in clinically diagnosed patients, this mutation accounted for 90% of defective alleles. Unclassified variants (UVs or VUSs) are especially critical when considering screening programs. The functional and pathogenic characterization of genetic variants presented here is required to predict their medical consequences in newborns. PMID:24294134

Expansion, retention and loss in the Acyl-CoA synthetase "Bubblegum" (Acsbg) gene family in vertebrate history.

Science.gov (United States)

Lopes-Marques, Mónica; Machado, André M; Ruivo, Raquel; Fonseca, Elza; Carvalho, Estela; Castro, L Filipe C

2018-07-20

Fatty acids (FAs) constitute a considerable fraction of all lipid molecules with a fundamental role in numerous physiological processes. In animals, the majority of complex lipid molecules are derived from the transformation of FAs through several biochemical pathways. Yet, for FAs to enroll in these pathways they require an activation step. FA activation is catalyzed by the rate limiting action of Acyl-CoA synthases. Several Acyl-CoA enzyme families have been previously described and classified according to the chain length of FAs they process. Here, we address the evolutionary history of the ACSBG gene family which activates, FAs with >16 carbons. Currently, two different ACSBG gene families, ACSBG1 and ACSBG2, are recognized in vertebrates. We provide evidence that a wider and unequal ACSBG gene repertoire is present in vertebrate lineages. We identify a novel ACSBG-like gene lineage which occurs specifically in amphibians, ray finned fishes, coelacanths and cartilaginous fishes named ACSBG3. Also, we show that the ACSBG2 gene lineage duplicated in the Theria ancestor. Our findings, thus offer a far richer understanding on FA activation in vertebrates and provide key insights into the relevance of comparative and functional analysis to perceive physiological differences, namely those related with lipid metabolic pathways. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular characterization of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

DEFF Research Database (Denmark)

Gregersen, N; Andresen, B S; Bross, P

1991-01-01

. All clones sequenced from the patient exhibited a single base substitution from adenine (A) to guanine (G) at position 985 in the MCAD cDNA as the only consistent base-variation compared with control cDNA. In contrast, the parents contained cDNA with the normal and the mutated sequence, revealing......A series of experiments has established the molecular defect in the medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) gene in a family with MCAD deficiency. Demonstration of intra-mitochondrial mature MCAD indistinguishable in size (42.5-kDa) from control MCAD, and of mRNA with the correct...... size of 2.4 kb, indicated a point-mutation in the coding region of the MCAD gene to be disease-causing. Consequently, cloning and DNA sequencing of polymerase chain reaction (PCR) amplified complementary DNA (cDNA) from messenger RNA of fibroblasts from the patient and family members were performed...

The C-Terminal O-S Acyl Shift Pathway under Acidic Condition to Propose Peptide-Thioesters

Directory of Open Access Journals (Sweden)

Bo Mi Kim

2016-11-01

Full Text Available Peptide-thioester is a pivotal intermediate for peptide ligation and N-, C-terminal cyclization. In this study, desired pathway and the side products of two C-terminal handles, hydroxyethylthiol (HET and hydroxypropylthiol (HPT are described in different conditions as well as kinetic studies. In addition, a new mechanism of C-terminal residue racemization is proposed on the basis of differentiation of products derived from the two C-terminal handles in preparing peptide thioesters through an acid-catalyzed tandem thiol switch, first by an intramolecular O-S acyl shift, and then by an intermolecular S-S exchange.

alpha,beta-unsaturated 2-acyl imidazoles as a practical class of dienophiles for the DNA-Based catalytic asymmetric diels-alder reaction in water

NARCIS (Netherlands)

Boersma, A.J.; Feringa, B.L.; Roelfes, G.

2007-01-01

alpha,beta-Unsaturated 2-acyl imidazoles are a novel and practical class of dienophiles for the DNA-based catalytic asymmetric Diels-Alder reaction in water. The Diels-Alder products are obtained with very high diastereoselectivities and enantioselectivities in the range of 83-98%. The catalytic

Genetic Basis for Correction of Very‐Long‐Chain Acyl-Coenzyme A Dehydrogenase Deficiency by Bezafibrate in Patient Fibroblasts: Toward a Genotype‐Based Therapy

DEFF Research Database (Denmark)

Gobin‐Limballe, S.; Djouadi, F.; Aubey, F.

2007-01-01

Very‐long‐chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency is an inborn mitochondrial fatty‐acid β‐oxidation (FAO) defect associated with a broad mutational spectrum, with phenotypes ranging from fatal cardiopathy in infancy to adolescent‐onset myopathy, and for which there is no established...